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Sample records for 800nm mi-frog measures

  1. Femtosecond Coherent Spectroscopy at 800nm: MI-FROG Measures High-Field Ionization Rates in Gases

    SciTech Connect

    Siders, C.W.; Siders, J.L.W.; Taylor, A.J.

    1999-05-24

    The authors report the first quantitative phase-sensitive measurement of ultrafast ionization rates in gases using Multi-phase Interferometric Frequency-Resolved Optical Gating. Ultrafast probe depletion via frequency mixing in the ionization front is observed.

  2. Optical measurement of temperature in biological cells under infrared laser light exposure (λ=800 nm)

    NASA Astrophysics Data System (ADS)

    Moreau, David; Lefort, Claire; Leveque, Philippe; O'Connor, Rod P.

    2015-07-01

    Interest in the interaction between laser light and biological samples has gained momentum in recent years, particularly in neurobiology, where there is significant potential to stimulate neurons with infrared laser light. Despite recent reports showing the application of infrared light for neurostimulation, the underlying mechanism is still unknown. The two main hypotheses are based on thermal or electrostatic mechanisms. Here, a novel optical method is presented to make temperature measurements in human neural cells under infrared laser excitation (λ=800nm) using the dye Rhodamine B (RhB). The measurement of temperature is based on the property of RhB, a fluorescent dye whose fluorescence intensity decreases linearly with increases in temperature. We present and detail the setup and measurement procedure that has temporal resolution of few milliseconds, based around a fluorescent live-cell imaging microscope used for cellular microfluorimetry experiments.

  3. Fiber Bragg gratings inscriptions in multimode fiber using 800 nm femtosecond laser for high-temperature strain measurement

    NASA Astrophysics Data System (ADS)

    Yang, Tingting; Qiao, Xueguang; Rong, Qiangzhou; Bao, Weijia

    2017-08-01

    A short fiber Bragg grating (FBG) is successfully written in a multimode fiber (MMF) with core and cladding diameters of 50 μm and 125 μm using 800 nm femtosecond laser side-illumination technique. Three-type grating inscriptions can be realized at the different positions over the core of MMF by moving the focal-line position of laser beam. Both fundamental mode and higher-order modes of MMF are excited at the core-mismatch junction, resulting in two well-defined resonances in transmission. The strain measurement with a single core resonance mode is demonstrated experimentally at the ultra-high temperature. The result indicates that the strain sensitivity improved to 5.24 pm/με at the temperature of 600-900 °C, making it as a good candidate for the strain measurement at the high temperature environments.

  4. High-brightness 800nm fiber-coupled laser diodes

    NASA Astrophysics Data System (ADS)

    Berk, Yuri; Levy, Moshe; Rappaport, Noam; Tessler, Renana; Peleg, Ophir; Shamay, Moshe; Yanson, Dan; Klumel, Genadi; Dahan, Nir; Baskin, Ilya; Shkedi, Lior

    2014-03-01

    Fiber-coupled laser diodes have become essential sources for fiber laser pumping and direct energy applications. Single emitters offer reliable multi-watt output power from a 100 m lateral emission aperture. By their combination and fiber coupling, pump powers up to 100 W can be achieved from a low-NA fiber pigtail. Whilst in the 9xx nm spectral range the single emitter technology is very mature with <10W output per chip, at 800nm the reliable output power from a single emitter is limited to 4 W - 5 W. Consequently, commercially available fiber coupled modules only deliver 5W - 15W at around 800nm, almost an order of magnitude down from the 9xx range pumps. To bridge this gap, we report our advancement in the brightness and reliability of 800nm single emitters. By optimizing the wafer structure, laser cavity and facet passivation process we have demonstrated QCW device operation up to 19W limited by catastrophic optical damage to the 100 μm aperture. In CW operation, the devices reach 14 W output followed by a reversible thermal rollover and a complete device shutdown at high currents, with the performance fully rebounded after cooling. We also report the beam properties of our 800nm single emitters and provide a comparative analysis with the 9xx nm single emitter family. Pump modules integrating several of these emitters with a 105 μm / 0.15 NA delivery fiber reach 35W in CW at 808 nm. We discuss the key opto-mechanical parameters that will enable further brightness scaling of multi-emitter pump modules.

  5. IFEL-Chicane Based Microbuncher at 800nm

    NASA Astrophysics Data System (ADS)

    Sears, Christopher M. S.; Colby, Eric; Barnes, Christopher

    2004-12-01

    As a first stage to net acceleration in a laser based EM structure RF electron pulses must be microbunched to match the laser wavelength. We report on the design of an undulator and chicane for microbunching at 800nm using an inverse free electron laser (IFEL) interaction. This includes design considerations for the hardware itself, the laser IFEL interaction and bunching performance, and a full 3D particle tracking simulation to study the focusing effects and possible emittance growth due to the fringe fields of the magnets. The talk will close with a discussion of laser-electron beam diagnostics for overlap in the undulator and for diagnosing microbunching performance.

  6. Correlating Pulses from Two Spitfire, 800nm Lasers

    SciTech Connect

    Colby, Eric R.; Mcguinness, C.; Zacherl, W.D.; Plettner, T.; /Stanford U., Phys. Dept.

    2008-01-28

    The E163 laser acceleration experiments conducted at SLAC have stringent requirements on the temporal properties of two regeneratively amplified, 800nm, Spitfire laser systems. To determine the magnitude and cause of timing instabilities between the two Ti:Sapphire amplifiers, we pass the two beams through a cross-correlator and focus the combined beam onto a Hamamatsu G1117 photodiode. The photodiode has a bandgap such that single photon processes are suppressed and only the second order, two-photon process produces an observable response. The response is proportional to the square of the intensity. The diode is also useful as a diagnostic to determine the optimal configuration of the compression cavity.

  7. The 800-nm diode laser irradiation induces skin collagen synthesis by stimulating TGF-β/Smad signaling pathway.

    PubMed

    Dang, Yongyan; Liu, Bei; Liu, Lianxi; Ye, Xiyun; Bi, Xinling; Zhang, Yong; Gu, Jun

    2011-11-01

    The 800-nm diode laser is used clinically for hair removal and leg vein clearance. However, the effects of the laser on skin collagen synthesis have not been established. This study aims to research whether the 800-nm laser can be used for non-ablative rejuvenation and its possible mechanism by using an animal model. Eight 2-month-old rats were irradiated with the 800-nm diode laser at 20, 40, and 60 J/cm(2), respectively. Skin samples were taken for histological study and dermal thickness measurement at day 30 after laser irradiation. The expression of procollagen type I, III, IV, transforming growth factor-β (TGF-β), Smad2, 3, 4, and phosphorylated-Smad2, 3 in the rat skin was analyzed 24 h after completing all laser treatments by using RT-PCR and Western blot. Immunohistochemistry was performed to evaluate the content of type I collagen in the skin at day 30 after laser irradiation. The 800-nm diode laser treatments markedly improved the histological structure and increased dermal thickness compared to the non-irradiated controls. Laser irradiation at 40 J/cm(2) significantly up-regulated the expression of procollagen type I and IV, TGF-β and Smad2, 3, 4. The p-Smad2 and p-Smad3 levels were also enhanced in the laser-irradiated skin. The 800-nm laser is effective in improving skin structure and inducing skin new collagen expression. New collagen synthesis induced by the 800-nm laser was mediated by TGF-β/Smad signaling pathway. Thus, it seemed that the 800-nm laser could be used for non-ablative rejuvenation in the future.

  8. Nonlinear refraction properties of nickel oxide thin films at 800 nm

    SciTech Connect

    Melo, Ronaldo P. Jr. de; Silva, Blenio J. P. da; Santos, Francisco Eroni P. dos; Azevedo, A.; Araujo, Cid B. de

    2009-11-01

    Measurements of the nonlinear refractive index, n{sub 2}, of nickel oxide films prepared by controlled oxidation of nickel films deposited on substrates of soda-lime glass are reported. The structure and morphology of the samples were characterized by scanning electron microscopy, atomic force microscopy, and x-ray diffractometry. Samples of excellent optical quality were prepared. The nonlinear measurements were performed using the thermally managed eclipse Z-scan technique at 800 nm. A large value of n{sub 2}approx =10{sup -12} cm{sup 2}/W and negligible nonlinear absorption were obtained.

  9. Ultrahigh-resolution tethered OCT endoscopic capsule at 800 nm (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Li, Kaiyan; Mavadia-Shukla, Jessica; Liang, Wenxuan; Li, Xingde

    2017-02-01

    We present an ultrahigh-resolution, distal-scanning OCT capsule operating at 800 nm targeted towards gastrointestinal tract imaging. Among many others, one significant challenge in the 800-nm OCT capsule technology is the severe chromatic aberration in the imaging optics of the capsule. By combining commercial miniature lenses and customized diffractive lens, the achromatic focal shift was essentially eliminated (i.e. down to 1 µm) over a 3dB spectral bandwidth of 150 nm centered around 825 nm. We have achieved an axial resolution 2.7 µm. Initial proof-of-concept experiments with ex vivo pig esophagus demonstrated the excellent imaging performance of this 800-nm OCT capsule.

  10. Nonlinear absorption of femtosecond laser pulses (800 nm) by atmospheric air and water vapour

    SciTech Connect

    Kiselev, A M; Ponomarev, Yu N; Stepanov, A N; Tikhomirov, A B; Tikhomirov, B A

    2011-11-30

    Quantitative data on the nonlinear absorption cross sections of femtosecond Ti : Sapphire laser pulses in air and water vapour have been obtained. A photoacoustic spectrometer calibrated based on the calculated value of linear absorption of laser pulses with a wavelength of 800 nm and a spectral width of 17.7 nm is used to find the nonlinear absorption cross sections of water vapour and air: {sigma}{sub 2}{sup w} = (2.6{+-}0.4) Multiplication-Sign 10{sup -55} cm{sup 4} s and {sigma}{sub 2}{sup a} = (8.7{+-}1.0) Multiplication-Sign 10{sup -56} cm{sup 4} s, respectively. Based on measuring the absorption of femtosecond Ti : Sapphire laser pulses with a photoacoustic detector calibrated with the known linear absorption of ruby laser radiation by water vapour in air, the air nonlinear absorption cross section is found to be (8.2{+-}0.9) Multiplication-Sign 10{sup -56} cm{sup 4} s.

  11. High-harmonic inverse-free-electron-laser interaction at 800 nm.

    PubMed

    Sears, Christopher M S; Colby, Eric R; Cowan, Benjamin M; Siemann, Robert H; Spencer, James E; Byer, Robert L; Plettner, Tomas

    2005-11-04

    We present the first direct observation of a higher-order inverse-free-electron-laser (IFEL) interaction. Interaction at the fourth, fifth, and sixth harmonics is observed from an IFEL operating at 800 nm. The harmonic spacing, relative harmonic strength, and transverse beam overlap of the interaction are all in good agreement with tracking simulations.

  12. High-Harmonic Inverse-Free-Electron-Laser Interaction at 800 nm

    NASA Astrophysics Data System (ADS)

    Sears, Christopher M. S.; Colby, Eric R.; Cowan, Benjamin M.; Siemann, Robert H.; Spencer, James E.; Byer, Robert L.; Plettner, Tomas

    2005-11-01

    We present the first direct observation of a higher-order inverse-free-electron-laser (IFEL) interaction. Interaction at the fourth, fifth, and sixth harmonics is observed from an IFEL operating at 800 nm. The harmonic spacing, relative harmonic strength, and transverse beam overlap of the interaction are all in good agreement with tracking simulations.

  13. Photoionization and photofragmentation of gaseous toluene using 80-fs, 800-nm laser pulses

    NASA Astrophysics Data System (ADS)

    Müller, A. M.; Uiterwaal, C. J. G. J.; Witzel, B.; Wanner, J.; Kompa, K.-L.

    2000-06-01

    This paper presents ion yields resulting from multiphoton ionization and fragmentation of gaseous toluene (C7H8) in the focus of an 80 fs Ti:sapphire laser beam (λ=800 nm) with a sufficiently small B-integral [Siegman, Lasers (University Science Books, Mill Valley, CA, 1986)]. The peak intensity was varied between 1.9×1013 and 2.8×1014W cm-2, and both linear and circular polarization were used. Over the whole range of intensities studied, only the singly charged parent ion and its fragment, C7H7+, are found. Although the Keldysh adiabaticity parameter equals 0.86 for the saturation intensity of ˜1×1014W cm-2, there is no indication of tunneling. The parent ion yield is found to be effectively proportional to the sixth power of the peak intensity. This is shown to be in good agreement with a multiple lowest-order perturbation multiphoton ionization model which takes into account successive channel closing for increasing peak intensities and orders up to 11 inclusive. On the assumption that the excess energy acquired by the toluene cation as a result of the interaction with the electromagnetic field is of the order of the ponderomotive energy for the intensity prevailing at the moment of the ionization, the internal energy distribution of the toluene cations created that is brought about by this multiple-order multiphoton ionization model is calculated. This internal energy distribution is in perfect agreement with the measured C7H7+ yield, if the rate-energy curve for the fragmentation of excited toluene cations as given by Golovin et al. [Sov. J. Chem. Phys. 2, 632 (1985)] is moderately reduced by a factor of 4.5.

  14. Fiber Bragg grating inscriptions in multimode fiber using 800 nm femtosecond laser

    NASA Astrophysics Data System (ADS)

    Rong, Qiangzhou; Qiao, Xueguang

    2015-09-01

    A short fiber Bragg grating (FBG) was successfully written in a multimode fiber (MMF) tube with core and cladding diameters of 105 μm and 125 μm using 800 nm femtosecond laser. A side-illumination technique was utilized to ensure the grating inscriptions regain over the core of MMF. Both fundamental mode and high-order modes of MMF are coupled at the core-mismatch junction and appear as two well-defined resonances in transmission. Femtosecond laserwritten three FBG-types present good thermostability up to 900 °C.

  15. Optical limiting property of a liquid malononitrile derivative on 800 nm laser pulses

    NASA Astrophysics Data System (ADS)

    Du, Juan; Wang, Liuheng; Xie, Na; Sun, Li; Wang, Xiaodong; Zhao, Yuxia; Wu, Feipeng

    2016-08-01

    A new liquid malononitrile derivative (LBDBP) has been synthesized by incorporating four tetraethylene glycol groups into the prototype scaffold of 2-[Bis-(4‧-diethylamino-biphenyl-4-yl)-methylene]-malononitrile (BDBP). The linear photophysical properties, optical/thermal stabilities and optical limiting behaviors of LBDBP and BDBP have been investigated. The results show that LBDBP has equivalent optical/thermal stability but much better solubility compared with BDBP. Its saturation concentration in DMF is increased to 0.075 M, while the corresponding datum for BDBP is only 0.01 M. The improved solubility of LBDBP insures a very significant optical limiting behavior. The saturated DMF solution of LBDBP can significantly reduce the intensity fluctuation of laser pulses in an 800 nm laser setup.

  16. Switching of 800 nm femtosecond laser pulses using a compact PMN-PT modulator.

    PubMed

    Adany, Peter; Price, E Shane; Johnson, Carey K; Zhang, Run; Hui, Rongqing

    2009-03-01

    A voltage-controlled birefringent cell based on ceramic PMN-PT material is used to enable fast intensity modulation of femtosecond laser pulses in the 800 nm wavelength window. The birefringent cell based on a PMN-PT compound has comparatively high electro-optic response, allowing for a short interaction length of 3 mm and thus very small size, low attenuation of 0.16 dB, and negligible broadening for 100 fs optical pulses. As an application example, agile wavelength tuning of optical pulses is demonstrated using the soliton self-frequency shift in a photonic crystal fiber. By dynamically controlling the optical power into the fiber, this system switches the wavelength of 100 fs pulses from 900 nm to beyond 1120 nm with less than 5 micros time. In addition, a feedback system stabilizes the wavelength drift against external conditions resulting in high wavelength stability.

  17. TCSPC FLIM in the wavelength range from 800 nm to 1700 nm (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Becker, Wolfgang; Shcheslavsky, Vladislav

    2016-03-01

    Excitation and detection in the wavelength range above 800nm is a convenient and relatively inexpensive way to increase the penetration depth in optical microscopy. Moreover, detection at long wavelength avoids the problem that tissue autofluorescence contaminates the signals from endogenous fluorescence probes. FLIM at NIR wavelength may therefore be complementary to multiphoton microscopy, especially if the lifetimes of NIR fluorophores report biological parameters of the tissue structures they are bound to. Unfortunately, neither the excitation sources nor the detectors of standard confocal and multiphoton laser scanning systems are directly suitable for excitation and detection of NIR fluorescence. Most of these problems can be solved, however, by using ps diode lasers or Ti:Sapphire lasers at their fundamental wavelength, and NIR-sensitive detectors. With NIR-sensitive PMTs the detection wavelength range can be extended up to 900 nm, with InGaAs SPAD detectors up to 1700 nm. Here, we demonstrate the use of a combination of laser scanning, multi-dimensional TCSPC, and advanced excitation sources and detectors for FLIM at up to 1700 nm. The performance was tested at tissue samples incubated with NIR dyes. The fluorescence lifetimes generally get shorter with increasing absorption and emission wavelengths of the dyes. For the cyanine dye IR1061, absorbing around 1060 nm, the lifetime was found to be as short as 70 ps. Nevertheless the fluorescence decay could still be clearly detected. Almost all dyes showed clear lifetime changes depending on the binding to different tissue constituents.

  18. Fabrication of nanostructures on silicon carbide surface and microgroove sidewall using 800-nm femtosecond laser

    NASA Astrophysics Data System (ADS)

    Khuat, Vanthanh; Chen, Tao; Dao, Vanluu

    2015-07-01

    Nanoripples and nanoparticles have been fabricated on the surface of a silicon carbide sample with the irradiation of an 800-nm femtosecond laser in an underwater environment. When a linearly polarized laser was used, the nanoripples were perpendicular to the polarization direction of the incident laser, and the period of the nanoripples was dependent on the number of pulses. When a circularly polarized laser was used, nanoparticles with a diameter of approximately 80 nm were formed. In addition, we observed two kinds of nanoripples on the sidewall of the silicon carbide microgroove fabricated by femtosecond laser irradiation followed by chemical wet etching. When the polarization direction was aligned perpendicular to the writing direction, ripples parallel to the surface of the sample were formed. We attribute the formation of this kind of ripple to interference of the incident laser and the reflected wave. When the polarization direction was aligned parallel to the writing direction, the ripples are perpendicular to the surface of the sample. We attribute the formation of this kind of ripple to interference of incident laser and bulk electron plasma wave. A scanning electron microscope equipped with an energy dispersive X-ray spectroscope was employed to characterize the morphology of the structures.

  19. Experimental study on 800 nm femtosecond laser ablation of fused silica in air and vacuum

    NASA Astrophysics Data System (ADS)

    Xu, Shi-zhen; Yao, Cai-zhen; Liao, Wei; Yuan, Xiao-dong; Wang, Tao; Zu, Xiao-tao

    2016-10-01

    Ablation rates of fused silica were studied as a function of femtosecond laser pulse fluences (0.7-41 J/cm2) in air and vacuum. The experiment was conducted by using a Ti:sapphire laser that emits radiation at 800 nm with a pulse width of 35 fs and a repetition rate of 10 Hz. The morphology and ablation depth of laser-induced damage crater were evaluated by using optical microscopy and scanning electron microscopy (SEM). Ablation rates were calculated from the depth of craters induced by multiple laser pulses. Results showed that two ablation regimes, i.e. non-thermal and thermal ablation co-existed in air and vacuum at low and moderate fluences. A drop of ablation rate was observed at high fluence (higher than 9.5 J/cm2) in air. While in vacuum, the ablation rate increased continuously with the increasing of laser fluence and much higher than that in air. The drop of ablation rate observed at high fluence in air was due to the strong defocusing effects associated with the non-equilibrium ionization of air. Furthermore, the laser-induced damage threshold (LIDT), which was determined from the relationship between crater area and the logarithm of laser energy, was found to depend on the number of incident pulses on the same spot, and similar phenomenon was observed in air and vacuum.

  20. Generation of <7 fs pulses at 800 nm from a blue-pumped optical parametric amplifier at degeneracy.

    PubMed

    Siddiqui, A M; Cirmi, G; Brida, D; Kärtner, F X; Cerullo, G

    2009-11-15

    We generate ultrabroadband pulses at 800 nm from an optical parametric amplifier (OPA) pumped by the second harmonic of a Ti:sapphire system and working at degeneracy. The OPA is seeded by a white-light continuum generated from a near-IR OPA pumped by the same laser. Nearly transform-limited <7 fs pulses, fully characterized in amplitude and phase, are obtained with a chirped mirror compressor. The system fills the gap around 800 nm for broadband continuum seeded OPAs pumped by Ti:sapphire-based sources.

  1. Spectrally-broad coherent anti-Stokes Raman scattering hyper-microscopy utilizing a Stokes supercontinuum pumped at 800 nm.

    PubMed

    Porquez, Jeremy G; Cole, Ryan A; Tabarangao, Joel T; Slepkov, Aaron D

    2016-10-01

    We demonstrate spectral-focusing based coherent anti-Stokes Raman scattering (SF-CARS) hyper-microscopy capable of probing vibrational frequencies from 630 cm(-1) to 3250 cm(-1) using a single Ti:Sapphire femtosecond laser operating at 800 nm, and a commercially-available supercontinuum-generating fibre module. A broad Stokes supercontinuum with significant spectral power at wavelengths between 800 nm and 940 nm is generated by power tuning the fibre module using atypically long and/or chirped ~200 fs pump pulses, allowing convenient access to lower vibrational frequencies in the fingerprint spectral region. This work significantly reduces the instrumental and technical requirements for multimodal CARS microscopy, while expanding the spectral capabilities of an established approach to SF-CARS.

  2. Spectrally-broad coherent anti-Stokes Raman scattering hyper-microscopy utilizing a Stokes supercontinuum pumped at 800 nm

    PubMed Central

    Porquez, Jeremy G.; Cole, Ryan A.; Tabarangao, Joel T.; Slepkov, Aaron D.

    2016-01-01

    We demonstrate spectral-focusing based coherent anti-Stokes Raman scattering (SF-CARS) hyper-microscopy capable of probing vibrational frequencies from 630 cm−1 to 3250 cm−1 using a single Ti:Sapphire femtosecond laser operating at 800 nm, and a commercially-available supercontinuum-generating fibre module. A broad Stokes supercontinuum with significant spectral power at wavelengths between 800 nm and 940 nm is generated by power tuning the fibre module using atypically long and/or chirped ~200 fs pump pulses, allowing convenient access to lower vibrational frequencies in the fingerprint spectral region. This work significantly reduces the instrumental and technical requirements for multimodal CARS microscopy, while expanding the spectral capabilities of an established approach to SF-CARS. PMID:27867735

  3. Transcranial Near-Infrared Laser Transmission (NILT) Profiles (800 nm): Systematic Comparison in Four Common Research Species

    PubMed Central

    Lapchak, Paul A.; Boitano, Paul D.; Butte, Pramod V.; Fisher, David J.; Hölscher, Thilo; Ley, Eric J.; Nuño, Miriam; Voie, Arne H.; Rajput, Padmesh S.

    2015-01-01

    Background and Purpose Transcranial near-infrared laser therapy (TLT) is a promising and novel method to promote neuroprotection and clinical improvement in both acute and chronic neurodegenerative diseases such as acute ischemic stroke (AIS), traumatic brain injury (TBI), and Alzheimer’s disease (AD) patients based upon efficacy in translational animal models. However, there is limited information in the peer-reviewed literature pertaining to transcranial near-infrared laser transmission (NILT) profiles in various species. Thus, in the present study we systematically evaluated NILT characteristics through the skull of 4 different species: mouse, rat, rabbit and human. Results Using dehydrated skulls from 3 animal species, using a wavelength of 800nm and a surface power density of 700 mW/cm2, NILT decreased from 40.10% (mouse) to 21.24% (rat) to 11.36% (rabbit) as skull thickness measured at bregma increased from 0.44 mm in mouse to 0.83 mm in rat and then 2.11 mm in rabbit. NILT also significantly increased (p<0.05) when animal skulls were hydrated (i.e. compared to dehydrated); but there was no measurable change in thickness due to hydration. In human calvaria, where mean thickness ranged from 7.19 mm at bregma to 5.91 mm in the parietal skull, only 4.18% and 4.24% of applied near-infrared light was transmitted through the skull. There was a slight (9.2-13.4%), but insignificant effect of hydration state on NILT transmission of human skulls, but there was a significant positive correlation between NILT and thickness at bregma and parietal skull, in both hydrated and dehydrated states. Conclusion This is the first systematic study to demonstrate differential NILT through the skulls of 4 different species; with an inverse relationship between NILT and skull thickness. With animal skulls, transmission profiles are dependent upon the hydration state of the skull, with significantly greater penetration through hydrated skulls compared to dehydrated skulls. Using

  4. Correlated Two-Electron Momentum Spectra for Strong-Field Nonsequential Double Ionization of He at 800 nm

    SciTech Connect

    Rudenko, A.; Ergler, Th.; Zrost, K.; Feuerstein, B.; Schroeter, C. D.; Moshammer, R.; Ullrich, J.; Jesus, V. L. B. de

    2007-12-31

    We report on a kinematically complete experiment on nonsequential double ionization of He by 25 fs 800 nm laser pulses at 1.5 PW/cm{sup 2}. The suppression of the recollision-induced excitation at this high intensity allows us to address in a clean way direct (e,2e) ionization by the recolliding electron. In contrast with earlier experimental results, but in agreement with various theoretical predictions, the two-electron momentum distributions along the laser polarization axis exhibit a pronounced V-shaped structure, which can be explained by the role of Coulomb repulsion and typical (e,2e) kinematics.

  5. Efficient 1 kHz femtosecond optical parametric amplification in BiB(3)O(6) pumped at 800 nm.

    PubMed

    Ghotbi, Masood; Ebrahim-Zadeh, Majid; Petrov, Valentin; Tzankov, Pancho; Noack, Frank

    2006-10-30

    We demonstrate efficient operation of a tunable femtosecond optical parametric amplifier based on BiB(3)O(6) pumped at 800 nm by a 1 kHz Ti:sapphire regenerative amplifier. The idler wavelength coverage extends to beyond 3 mum and the pulse duration at this wavelength is of the order of 110 fs. This new nonlinear borate crystal offers exceptionally high nonlinearity, making it a very promising candidate for power scaling of such frequency converters in the near-IR.

  6. Fiber Bragg gratings inscribed using 800nm femtosecond laser and a phase mask in single- and multi-core mid-IR glass fibers.

    PubMed

    Suo, Rui; Lousteau, Joris; Li, Hongxia; Jiang, Xin; Zhou, Kaiming; Zhang, Lin; MacPherson, William N; Bookey, Henry T; Barton, James S; Kar, Ajoy K; Jha, Animesh; Bennion, Ian

    2009-04-27

    For the first time, Fiber Bragg grating (FBG) structures have been inscribed in single-core passive germanate and three-core passive and active tellurite glass fibers using 800 nm femtosecond (fs) laser and phase mask technique. With fs peak power intensity in the order of 10(11)W/cm(2), the FBG spectra with 2nd and 3rd order resonances at 1540 and 1033 nm in the germanate glass fiber and 2nd order resonances at approximately 1694 and approximately 1677 nm with strengths up to 14 dB in all three cores in the tellurite fiber were observed. Thermal responsivities of the FBGs made in these mid-IR glass fibers were characterized, showing average temperature responsivity approximately 20 pm/ degrees C. Strain responsivities of the FBGs in germanate glass fiber were measured to be 1.219 pm/microepsilon.

  7. Ruby Emission in the Range 400-800 nm with Excitation by Continuous-Wave CO2 Laser Pulses

    NASA Astrophysics Data System (ADS)

    Marchenko, V. M.; Kiselev, V. V.

    2017-01-01

    Thermal emission spectra of ruby single crystals in the range 400-800 nm were studied experimentally as functions of the intensity at 10.6 μm of exciting pulses ( 0.5 s) from a continuous-wave electrical-discharge CO2 laser. Spectra at excitation intensity 1-20 kW/cm2 were superpositions of the thermal emission continuum of the sapphire crystal lattice in the range 600-800 nm and selective emission spectra of Cr3+ that were observed for the first time for ruby and consisted of R-lines at 695 nm; N-lines at 715 nm; 2 T 1, 4 T 2 → 4 A 2 transition bands at 672 and 643 nm; and 4 T 1, 2 T 2 → 4 A 2 transition bands at 530 and 490 nm that were not observed in the luminescence spectrum. Time dependences of the shapes of selective emission spectra, quenching and shifts of the R 1 line, and the temperature dependence of ruby luminescence spectra were investigated.

  8. Leaf Level Chlorophyll Fluorescence Emission Spectra: Narrow Band versus Full 650-800 nm Retrievals

    NASA Astrophysics Data System (ADS)

    Middleton, E.; Zhang, Q.; Campbell, P. K.; Huemmrich, K. F.; Corp, L.; Cheng, Y.

    2012-12-01

    Recently, chlorophyll fluorescence (ChlF) retrievals in narrow spectral regions (< 1 nm, between 750-770 nm) of the near infrared (NIR) region of Earth's reflected radiation have been achieved from satellites, including the Japanese GOSAT and the European Space Agency's Sciamachy/Envisat. However, these retrievals sample the total full-spectrum ChlF and are made at non-optimal wavelengths since they are not located at the peak fluorescence emission features. We wish to estimate the total full-spectrum ChlF based on emissions obtained at selected wavelengths. For this, we drew upon leaf emission spectra measured on corn leaves obtained from a USDA experimental cornfield in MD (USA). These emission spectra were determined for the adaxial and abaxial (i.e., top and underside) surfaces of leaves measured throughout the 2008 and 2011 growing seasons (n>400) using a laboratory instrument (Fluorolog-3, Horiba Scientific, USA), recorded in either 1 nm or 5 nm increments with monochromatic excitation wavelengths of either 532 or 420 nm. The total ChlF signal was computed as the area under the continuous spectral emission curves, summing the emission intensities (counts per second) per waveband. The individual narrow (1 or 5 nm) waveband emission intensities were linearly related to full emission values, with variable success across the spectrum. Equations were developed to estimate total ChlF from these individual wavebands. Here, we report the results for the average adaxial/abaxial emissions. Very strong relationships were achieved for the relatively high fluorescence intensities at the red chlorophyll peak, centered at 685 nm (r2= 0.98, RMSE = 5.53 x 107 photons/s) and in the nearby O2-B atmospheric absorption feature centered at 688 nm (r2 = 0.94, RMSE = 4.04 x 107), as well as in the far-red peak centered at 740 nm (r2=0.94, RMSE = 5.98 x107). Very good retrieval success occurred for the O2-A atmospheric absorption feature on the declining NIR shoulder centered at 760

  9. Comparison of glass processing using high-repetition femtosecond (800 nm) and UV (255 nm) nanosecond pulsed lasers

    NASA Astrophysics Data System (ADS)

    Karnakis, Dimitris M.; Knowles, Martyn R. H.; Alty, Kevin T.; Schlaf, Martin; Snelling, Howard V.

    2005-01-01

    Laser processing of glass is of significant commercial interest for microfabrication of "lab-on-a-chip" microfluidic devices. High repetition rate pulsed lasers have been investigated and provide adequate processing speeds but suffer from the inherent risk of laser-induced microcracking and other collateral damage induced in the glass. In this paper we present a comparative study between nanosecond deep UV (255nm) frequency doubled copper laser and femtosecond Ti:Sapphire (800nm) regenerative amplifier laser machining of borosilicate glass. Microchannel scribing and high aspect ratio hole drilling is demonstrated in thick glass using direct writing and mask projection techniques. The resulting material structure geometries have been examined using SEM microscopy and white light interferometry. The feasibility of glass laser machining and the significance of each laser type for this application are discussed.

  10. Fundamental research on the action mechanism of the 800 nm semiconductor laser on skin blackheads and coarse pores

    PubMed Central

    Lin, Jie; Jing, Li; Zhu, Hao; Dong, Fu-Sheng

    2017-01-01

    The aim of the study was to determine the mechanism of action of the 800 nm semiconductor laser on skin blackheads and coarse pores. A total of 24 healthy purebred short-haired male guinea pigs, weighing 350–400 g, were selected and smeared with 0.5 ml coal tar suspension evenly by injector once daily. Treatment was continued for 14 days to form an experimental area of 8×3 cm on the back of the guinea pigs. The animals were divided into the following groups: Normal control group (NC), low-dose laser treatment group (L-LS), high-dose laser treatment group (H-LS), and Q-switched Nd:YAG treatment group (QC). Samples were extracted 1, 7 and 14 days after surgery and hematoxylin and eosin staining was used to identify the following: Epidermis, dermis, sebaceous gland change and hair follicle damage; the expression of proliferating cell nuclear antigen (PCNA) of sebaceous gland cells using immunohistochemistry; sebaceous gland cell apoptosis using TUNEL; and the protein expression of caspase-3, Bax and Bcl-2 using western blot analysis. With the extension of time, we observed inflammatory cell infiltration, an increase in hair follicle distortion and necrosis of the surrounding hair follicles. The expression levels of PCNA of the L-LS, H-LS and QC groups decreased with time. Regarding the respective time points, the NC group was highest, the L-LS and H-LS groups were next highest and the H-LS group was lowest. The difference was statistically significant (P<0.05). The apoptotic rate of the L-LS, H-LS and QC groups increased with time. With regard to the respective time points, the NC group was lowest, the L-LS and QC groups were next lowest and the H-LS group was highest. The difference was statistically significant (P<0.05). The protein expression of caspase-3, Bax and Bcl-2 of the L-LS, H-LS and QC groups increased with time. Regarding the respective time points, caspase-3 and Bax protein expression of the NC group was lowest, the L-LS and QC groups were next lowest

  11. Approximately 800-nm-Thick Pinhole-Free Perovskite Films via Facile Solvent Retarding Process for Efficient Planar Solar Cells.

    PubMed

    Yuan, Zhongcheng; Yang, Yingguo; Wu, Zhongwei; Bai, Sai; Xu, Weidong; Song, Tao; Gao, Xingyu; Gao, Feng; Sun, Baoquan

    2016-12-21

    Device performance of organometal halide perovskite solar cells significantly depends on the quality and thickness of perovskite absorber films. However, conventional deposition methods often generate pinholes within ∼300 nm-thick perovskite films, which are detrimental to the large area device manufacture. Here we demonstrated a simple solvent retarding process to deposit uniform pinhole free perovskite films with thicknesses up to ∼800 nm. Solvent evaporation during the retarding process facilitated the components separation in the mixed halide perovskite precursors, and hence the final films exhibited pinhole free morphology and large grain sizes. In addition, the increased precursor concentration after solvent-retarding process led to thick perovskite films. Based on the uniform and thick perovskite films prepared by this convenient process, a champion device efficiency up to 16.8% was achieved. We believe that this simple deposition procedure for high quality perovskite films around micrometer thickness has a great potential in the application of large area perovskite solar cells and other optoelectronic devices.

  12. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): Design of a High-Nonlinearity Single-Mode Holey Fiber with Flattened Dispersion around 800 nm

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Hou, Lan-Tian; Liu, Zhao-Lun; Zhou, Gui-Yao

    2009-11-01

    We numerically demonstrate a high-nonlinearity single-mode holey fiber with flattened dispersion around the Ti-Za laser band at 800 nm. The dispersion profile of the fiber has the shape of a quadratic curve, which reaches its maximum 5.96 ps.km-1 .nm-1 at 800 nm and its minimum -0.897 ps.km-1 .nm-1 at both 750 and 850 nm. The nonlinear coefficient is 170 W-1 km-1 at 800 nm and no higher order modes exit. A six-layer air-hole cladding ensures a loss less than 0.067 db/m in the 750 to 850 nm range. Two more air-hole rings will reduce the loss to below 0.1 db/km.

  13. Nd3+ sensitized up/down converting dual-mode nanomaterials for efficient in-vitro and in-vivo bioimaging excited at 800 nm.

    PubMed

    Li, Xiaomin; Wang, Rui; Zhang, Fan; Zhou, Lei; Shen, Dengke; Yao, Chi; Zhao, Dongyuan

    2013-12-18

    Core/shell1/shell2/shell3 structured NaGdF4:Nd/NaYF4/NaGdF4:Nd,Yb,Er/NaYF4 nanocrystals were well designed and synthesized, each of the parts assume respective role and work together to achieve dual-mode upconverting (UC) and downconverting (DC) luminescence upon the low heat effect 800-nm excitation. Nd(3+), Yb(3+), Er(3+) tri-doped NaGdF4:Nd,Yb,Er UC layer [NIR (800 nm)-to-Visible (540 nm)] with a constitutional efficient 800 nm excitable property were achieved for the in-vitro bioimaging with low auto-fluorescence and photo-damage effects. Moreover, typical NIR (800 nm)-to-NIR (860-895 nm) DC luminescence of Nd(3+) has also been realized with this designed nanostructure. Due to the low heat effect, high penetration depth of the excitation and the high efficiency of the DC luminescence, the in-vivo high contrast DC imaging of a whole body nude mouse was achieved. We believe that such dual-mode luminescence NCs will open the door to engineering the excitation and emission wavelengths of NCs and will provide a new tool for a wide variety of applications in the fields of bioanalysis and biomedical.

  14. S100a8/NF-κB signal pathway is involved in the 800-nm diode laser-induced skin collagen remodeling.

    PubMed

    Ren, Xiaolin; Ge, Minggai; Qin, Xiaofeng; Xu, Peng; Zhu, Pingya; Dang, Yongyan; Gu, Jun; Ye, Xiyun

    2016-05-01

    The 800-nm diode laser is widely used for hair removal and also promotes collagen synthesis, but the molecular mechanism by which dermis responses to the thermal damage induced by the 800-nm diode laser is still unclear. Ten 2-month-old mice were irradiated with the 800-nm diode laser at 20, 40, and 60 J/cm(2), respectively. Skin samples were taken for PCR, Western blot analysis, and histological study at day 3 or 30 after laser irradiation. The expression of S100a8 and its two receptors (advanced glycosylation end product-specific receptor, RAGE and toll-like receptor 4, TRL4) was upregulated at day 3 after laser treatments. P-p65 levels were also elevated, causing the increase of cytokine (tumor necrosis factor, TNF-α and interleukin 6, IL-6) and MMPs (MMP1a, MMP9). At day 30, PCR and Western blot analysis showed significant increase of type I and III procollagen in the dermis treated with laser. Importantly, skin structure was markedly improved in the laser-irradiated skin compared with the control. Thus, it seemed that S100a8 upregulation triggered NF-κB signal pathway through RAGE and TLR4, responding to laser-induced dermis wound healing. The involvement of the NF-κB pathway in MMP gene transcription promoted the turnover of collagen in the skin, accelerating new collagen synthesis.

  15. Writing of Bragg gratings through the polymer jacket of low-loss As2S3 fibers using femtosecond pulses at 800 nm.

    PubMed

    Bernier, M; El-Amraoui, M; Couillard, J F; Messaddeq, Y; Vallée, R

    2012-09-15

    Fiber Bragg gratings (FBG) were written through the polymer jacket of low-loss single mode As(2)S(3) chalcogenide fibers by using femtosecond laser pulses at 800 nm and a phase-mask. Peak reflectivity in excess of 99% was obtained at 3440 nm after 5 min of exposure. The resulting FBG maintained a peak reflectivity of 90% after 64 min of thermal annealing at 100 °C. This demonstration paves the way to the development of all-fiber mid-infrared laser sources.

  16. Direct writing of 150 nm gratings and squares on ZnO crystal in water by using 800 nm femtosecond laser.

    PubMed

    Liu, Jukun; Jia, Tianqing; Zhou, Kan; Feng, Donghai; Zhang, Shian; Zhang, Hongxin; Jia, Xin; Sun, Zhenrong; Qiu, Jianrong

    2014-12-29

    We present a controllable fabrication of nanogratings and nanosquares on the surface of ZnO crystal in water based on femtosecond laser-induced periodic surface structures (LIPSS). The formation of nanogrooves depends on both laser fluence and writing speed. A single groove with width less than 40 nm and double grooves with distance of 150 nm have been produced by manipulating 800 nm femtosecond laser fluence. Nanogratings with period of 150 nm, 300 nm and 1000 nm, and nanosquares with dimensions of 150 × 150 nm2 were fabricated by using this direct femtosecond laser writing technique.

  17. Three-dimensional optical coherence tomography at 1050 nm versus 800 nm in retinal pathologies: enhanced performance and choroidal penetration in cataract patients.

    PubMed

    Povazay, Boris; Hermann, Boris; Unterhuber, Angelika; Hofer, Bernd; Sattmann, Harald; Zeiler, Florian; Morgan, James E; Falkner-Radler, Christiane; Glittenberg, Carl; Blinder, Susanne; Drexler, Wolfgang

    2007-01-01

    Frequency domain optical coherence tomography (FD-OCT), based on an all-reflective high-speed InGaAs spectrometer, operating in the 1050 nm wavelength region for retinal diagnostics, enables high-speed, volumetric imaging of retinal pathologies with greater penetration into choroidal tissue is compared to conventional 800 nm three-dimensional (3-D) ophthalmic FD-OCT systems. Furthermore, the lower scattering at this wavelength significantly improves imaging performance in cataract patients, thereby widening the clinical applicability of ophthalmic OCT. The clinical performance of two spectrometer-based ophthalmic 3-D OCT systems compared in respect to their clinical performance, one operating at 800 nm with 150 nm bandwidth (approximately 3 microm effective axial resolution) and the other at 1050 nm with 70 nm bandwidth (approximately 7 microm effective axial resolution). Results achieved with 3-D OCT at 1050 nm reveal, for the first time, decisive improvements in image quality for patients with retinal pathologies and clinically significant cataract.

  18. Mechanisms of the blue emission of NaYF4:Tm(3+) nanoparticles excited by an 800 nm continuous wave laser.

    PubMed

    Zhang, Hongxin; Jia, Tianqing; Shang, Xiaoying; Zhang, Shian; Sun, Zhenrong; Qiu, Jianrong

    2016-10-07

    A thorough understanding of energy transfer and upconversion (UC) processes between trivalent lanthanide (Ln(3+)) ions is essential and important for improving UC performance. However, because of the abundant energy states of Ln(3+) ions, UC mechanisms are very complicated, which makes it a challenge to exclusively verify and quantitatively evaluate the dominant process. In this study, the fundamental excitation processes of Tm(3+)-doped NaYF4 nanocrystals under 800 nm continuous wave (CW) laser excitation were experimentally investigated on the basis of the quantum transition principle. An 800 nm CW laser combined with other wavelength CW lasers, including 471 nm, 657 nm, 980 nm, and 1550 nm lasers, were designed to study in-depth the excitation processes of UC luminescence via simultaneous two-wavelength laser excitation. The results indicate that the excited state absorption of (3)H6→(3)H4∼∼(3)H5→(1)G4 is the dominant pathway of the 481 nm and 651 nm emission bands, and two kinds of energy transfer UC pathways, uniformly expressed as (1)G4 + (3)H4→(1)D2 + (3)F4, play the primary roles in the 456 nm emission band.

  19. High-power Femtosecond Optical Parametric Amplification at 1 kHz in BiB(3)O(6) pumped at 800 nm.

    PubMed

    Petrov, Valentin; Noack, Frank; Tzankov, Pancho; Ghotbi, Masood; Ebrahim-Zadeh, Majid; Nikolov, Ivailo; Buchvarov, Ivan

    2007-01-22

    Substantial power scaling of a travelling-wave femtosecond optical parametric amplifier, pumped near 800 nm by a 1 kHz Ti:sapphire laser amplifier, is demonstrated using monoclinic BiB(3)O(6) in a two stage scheme with continuum seeding. Total energy output (signal plus idler) exceeding 1 mJ is achieved, corresponding to an intrinsic conversion efficiency of approximately 32% for the second stage. The tunability extends from 1.1 to 2.9 microm. The high parametric gain and broad amplification bandwidth of this crystal allowed the maintenance of the pump pulse duration, leading to pulse lengths less than 140 fs, both for the signal and idler pulses, even at such high output levels.

  20. Enhancement of 800 nm upconversion emission in a thulium doped tellurite microstructured fiber pumped by a 1560 nm femtosecond fiber laser

    NASA Astrophysics Data System (ADS)

    Jia, Zhixu; Yao, Chuanfei; Wang, Shunbin; Zheng, Kezhi; Xiong, Liangming; Luo, Jie; Lv, Dajuan; Qin, Guanshi; Ohishi, Yasutake; Qin, Weiping

    2016-04-01

    We report enhanced upconversion (UC) fluorescence in Tm3+ doped tellurite microstructured fibers (TDTMFs) fabricated by using a rod-in-tube method. Under the pumping of a 1560 nm femtosecond fiber laser, ultrabroadband supercontinuum light expanding from ˜1050 to ˜2700 nm was generated in a 4 cm long TDTMF. Simultaneously, intense 800 nm UC emission from the 3H4 → 3H6 transition of Tm3+ was observed in the same TDTMF. Compared to that pumped by a 1560 nm continuous wave fiber laser, the UC emission intensity was enhanced by ˜4.1 times. The enhancement was due to the spectral broadening in the TDTMF under the pumping of the 1560 nm femtosecond fiber laser.

  1. Optimisation de l'émission du continuum femtoseconde de lumière blanche entre 600 nm et 800 nm

    NASA Astrophysics Data System (ADS)

    Ramstein, S.; Mottin, S.

    2005-06-01

    Un dispositif de spectroscopie avec résolution du temps de vol des photons en milieu diffus a été développé. Celui-ci repose sur l'utilisation d'un continuum de lumière blanche généré par focalisation d'un laser amplifié (830 nm, 1 kHz, 0.5 W, 170 fs) dans de l'eau déminéralisée. Afin d'optimiser spectralement et en puissance la source blanche sur la fenêtre spectrale 600 800 nm, une étude de la mise en forme spatio-temporelle avant autofocalisation de l'impulsion laser par le milieu a été menée. Cette mise en forme est effectuée de manière spatiale en changeant la focale de la lentille de focalisation et de manière temporelle en changeant le taux de compression de l'impulsion. L'étude montre que le cône de lumière émise possède plus de puissance dans la fenêtre spectrale d'intérêt pour des focales longues. Sur la fenêtre 600-800 nm, le rendement énergétique intégré varie de 5%, avec une focalef=6cm, à 15%, avec une focale f = 30 cm. La mise en forme temporelle montre des effets similaires avec les mêmes ordres de grandeur.

  2. Genotoxicity of visible light (400-800 nm) and photoprotection assessment of ectoin, L-ergothioneine and mannitol and four sunscreens.

    PubMed

    Botta, Céline; Di Giorgio, Carole; Sabatier, Anne-Sophie; De Méo, Michel

    2008-04-25

    This study was designed to determine the genotoxic effects of visible (400-800nm) and ultraviolet A (UVA)/visible (315-800nm) lights on human keratinocytes and CHO cells. The alkaline comet assay was used to quantify DNA-damage. In addition, photo-dependent cytogenetic lesions were assessed in CHO cells by the micronucleus test. Three protective compounds [ectoin, l-ergothioneine (ERT) and mannitol] were tested with the comet assay for their effectiveness to reduce DNA single-strand breaks (SSB). Finally, the genomic photoprotections of two broad-band sunscreens and their tinted analogues were assessed by the comet assay. The WST-1 cytotoxicity assay revealed a decrease of the keratinocyte viability of 30% and 13% for the highest UVA/visible and visible irradiations (15 and 13.8J/cm(2), respectively). Visible as well as UVA/visible lights induced DNA SSB and micronuclei, in a dose-dependent manner. The level of DNA breakage induced by visible light was 50% of the one generated by UVA/visible irradiation. However, UVA radiations were 10 times more effective than visible radiations to produce SSB. The DNA lesions induced by visible and UVA/visible lights were reduced after a 1-h preincubation period with the three tested compounds. The maximal protective effects were 92.7%, 97.9% and 52.0% for ectoin (0.1mM), ERT (0.5mM) and mannitol (1.5mM), respectively, against visible light and 68.9%, 59.8% and 62.7% for ectoin (0.1mM), ERT (0.5mM) and mannitol (1.5mM), respectively, against UVA/visible light. Thus, visible light was genotoxic on human keratinocytes and CHO cells through oxidative stress mechanisms similar to the ones induced by UVA radiations. The four tested sunscreens efficiently prevented DNA lesions that were induced by both visible and UVA/visible irradiations. The tinted sunscreens were slightly more effective that their colorless analogues. There is a need to complement sunscreen formulations with additional molecules to obtain a complete internal and

  3. Synthesis and characterization of cell-permeable caged phosphates that can be photolyzed by visible light or 800 nm two-photon photolysis.

    PubMed

    Herbivo, Cyril; Omran, Ziad; Revol, Julia; Javot, Hélène; Specht, Alexandre

    2013-11-25

    We report the synthesis and photolytic properties of caged inorganic phosphates (Pi compounds) based on the 2-(4'-{bis[2-(2-methoxyethoxy)ethyl]amino}-4-nitro-[1,1'-biphenyl]-3-yl)propan-1-ol (EANBP) and 7-(diethylamino)coumarin-4-yl]methyl (DEACM) protecting groups. The EANBP-Pi showed unprecedented photolysis efficiency at 405 nm, with 95 % release of free phosphate and a quantum yield of 0.28. Thanks to the high two-photon sensitivity of the EANBP chromophore, Pi release through two-photon photolysis is also possible, with an action cross section of 20.5 GM at 800 nm. Two bioactivatable acetoxymethyl protection groups were added to the "caged-Pi" compounds. The resulting triesters of phosphoric acid were able to diffuse through the cellular membranes of plant cells. Once inside a cell, the cleavage of these biocleavable motifs by intracellular esterases allows intracellular accumulation of EANBP-Pi. Bis(AM)-EANBP-Pi therefore represents a very attractive tool for study of the Pi signal transduction cascade in living cells.

  4. Long-term Comparison of a Large Spot Vacuum Assisted Handpiece vs the Small Spot Size Traditional Handpiece of the 800 nm Diode Laser.

    PubMed

    Youssef, Nour J; Rizk, Alain G; Ibrahimi, Omar A; Tannous, Zeina S

    2017-09-01

    BACKGROUND The 800 nm long-pulsed diode laser machine is safe and effective for permanent hair reduction. Traditionally, most long-pulsed diode lasers used for hair removal had a relatively small spot size. Recently, a long-pulsed diode laser with a large spot size and vacuum assisted suction handpiece was introduced. The treatment parameters of each type of handpiece differ. Short and long-term clinical efficacy, treatment associated pain, and patient satisfaction are important factors to be considered. This study aims to conduct a direct head to head comparison of both handpieces of the 800nm long-pulsed diode laser by evaluating long term hair reduction, treatment associated pain and patient satisfaction. Thirteen subjects were enrolled in this prospective, self-controlled, single-center study of axillary laser hair removal. The study involved 4 treatments using a long pulsed diode laser with a large spot size HS handpiece (single pass), HS handpiece (double pass), and a small spot size ET handpiece according to a randomized choice. The treatment sessions were done at 4-8 week intervals with follow up visits taken at 6 and 12 months after the last treatment session. Hair clearance and thickness analysis were assessed using macro hair count photographs taken at baseline visit, at each treatment session visit and at follow up visits. Other factors including pain, treatment duration, and patients' preference were secondary study endpoints. At 6 months follow up visits after receiving four laser treatments, there was statistically significant hair clearance in the three treatment arms with 66.1 % mean percentage hair reduction with the ET handpiece, 43.6% with the HSS (single pass) and 64.1 % with the HSD (double). However, at one year follow up, the results significantly varied from the 6 months follow up. The mean percentage hair reduction was 57.8% with the ET handpiece treated axillas (n=9), 16.5% with the HSS (single pass) handpiece treated axillas (n=7), and

  5. Objective assessment of skin tightening in Asians using a water-filtered near-infrared (1,000–1,800 nm) device with contact-cooling and freezer-stored gel

    PubMed Central

    Tanaka, Yohei; Tsunemi, Yuichiro; Kawashima, Makoto; Tatewaki, Naoto; Nishida, Hiroshi

    2013-01-01

    Background Near-infrared has been shown to penetrate deeper than optical light sources independent of skin color, allowing safer treatment for the Asian skin type. Many studies have indicated the efficacy of various types of devices, but have not included a sufficiently objective evaluation. In this study, we used three-dimensional imaging for objective evaluation of facial skin tightening using a water-filtered near-infrared device. Methods Twenty Japanese patients were treated with the water-filtered near-infrared (1,000–1,800 nm) device using a contact-cooling and nonfreezing gel stored in a freezer. Three-dimensional imaging was performed, and quantitative volume measurements were taken to evaluate the change in post-treatment volume. The patients then provided their subjective assessments. Results Objective assessments of the treated cheek volume evaluated by a three-dimensional color schematic representation with quantitative volume measurements showed significant improvement 3 months after treatment. The mean volume reduction at the last post-treatment visit was 2.554 ± 0.999 mL. The post-treatment volume was significantly reduced compared with the pretreatment volume in all patients (P < 0.0001). Eighty-five percent of patients reported satisfaction with the improvement of skin laxity, and 80% of patients reported satisfaction with improvement of rhytids, such as the nasolabial folds. Side effects, such as epidermal burns and scar formation, were not observed throughout the study. Conclusion The advantages of this water-filtered near-infrared treatment are its high efficacy for skin tightening, associated with a minimal level of discomfort and minimal side effects. Together, these characteristics facilitate our ability to administer repeated treatments and provide alternative or adjunctive treatment for patients, with improved results. This study provides a qualitative and quantitative volumetric assessment, establishing the ability of this technology to

  6. 2 μm emission performance in Tm3+/Er3+ codoped silicate glasses under 800 nm and 980 nm excitation

    NASA Astrophysics Data System (ADS)

    Cao, Ruijie; Lu, Yu; Tian, Ying; Huang, Feifei; Guo, Yanyan; Xu, Shiqing; Zhang, Junjie

    2017-03-01

    In this paper, mid-infrared 2 μm emission properties and energy transfer mechanism were investigated in Er3+/Tm3+ co-doped silicate glasses with optimized extra-low hydroxyl content ∂OH- (0.73 cm-1). The intensity parameters Ωt (t = 2, 4, 6) were calculated from the measured absorption spectra based on the Judd-Ofelt theory. The energy transfer efficiency from the Er3+:4I13/2 level to the Tm3+:3F4 level was calculated and reached up to 91.2% under 980 nm LD pumps and quantum efficiency is 63%. Meanwhile, the 1.85 μm band stimulated absorption and emission cross-sections of Tm3+:3F4 → 3H6 transitions were also obtained and analyzed. In addition, the measured ΔT (evaluate the glass forming ability) is as high as 297 °C, which shows that the silicate glass (SBET) possess good thermal stability. Hence, all of the present investigations indicate that the Er3+/Tm3+ co-doped silicate glasses have potential applications in 2 μm laser materials and may provide beneficial guide for investigation of population behaviors of Tm3+ ions at 2 μm emissions.

  7. Xe2 gerade Rydberg states observed in the afterglow of a microplasma by laser spectroscopy of a^3 {Σ }_u^ + ( {1_u,O_u^ - }) absorption in the green (545-555 nm) and near-infrared (675-800 nm)

    NASA Astrophysics Data System (ADS)

    Wagner, C. J.; Galvin, T. C.; Eden, J. G.

    2014-06-01

    Bound←bound transitions of the Xe dimer at small internuclear separation (R < 4.0 Å) have been observed in the 545-555 nm and 675-800 nm spectral regions by laser spectroscopy in the afterglow of a pulsed Xe microplasma with a volume of ˜160 nl. Transient suppression of Xe2 A^1 {Σ }_u^ + ( {O_u^ + }) to X^1 {Σ }_g^ + ( {O_g^ + }) emission in the vacuum ultraviolet (˜172 nm), induced by laser excitation of {Ω }_g leftarrow a^3 {Σ }_u^ + ( {1_u,O_u^ - }) [Rydberg←Rydberg] transitions of the molecule, has confirmed the existence of structure between 720 and 770 nm (reported by Killeen and Eden [J. Chem. Phys. 84, 6048 (1986)]) but also reveals red-degraded vibrational bands extending to wavelengths beyond 800 nm. Spectral simulations based on calculations of Franck-Condon factors for assumed {Ω }_g leftarrow a^3 {Σ }_u^ + transitions involving Ω = 0±,1 gerade Rydberg states suggest that the upper level primarily responsible for the observed spectrum is an Ω = 1 state correlated, in the separated atom limit, with Xe(5p6 1S0) + Xe(5p5 6p) and built on a predominantly A2Π3/2g molecular ion core. Specifically, the spectroscopic constants for the upper state of the 1_g leftarrow 1_u,O_u^ ± absorptive transitions are determined to be Te = 13 000 ± 150 cm-1, ω _e^' = 120 ± 10 cm^{ - 1}, ω _e^' x_e^' = 1.1 ± 0.4 cm^{ - 1}, De = 3300 ± 300 cm-1, and {Δ }R_e = R_e^' - R_e^' ' } = 0.3 ± 0.1 {Å} which are in general agreement with the theoretical predictions of the pseudopotential hole-particle formalism, developed by Jonin and Spiegelmann [J. Chem. Phys. 117, 3059 (2002)], for both the (5)1g and ( 3)O_g^ + states of Xe2. These spectra exhibit the most extensive vibrational development, and provide evidence for the first molecular core-switching transition, observed to date for any of the rare gas dimers at small R (<4 Ǻ). Experiments in the green (545-555 nm) also provide improved absorption spectra, relative to data reported in 1986 and 1999

  8. Determination of Optical-Field Ionization Dynamics in Plasmas through the Direct Measurement of the Optical Phase Change

    SciTech Connect

    Taylor, A.J.; Omenetto, G.; Rodriguez, G.; Siders, C.W.; Siders, J.L.W.; Downer, C.

    1999-07-16

    This is the final report of a three-year Laboratory Directed Research and Development (LDRD) Project at Los Alamos National Laboratory (LANL). The detailed dynamics of an atom in a strong laser field is rich in both interesting physics and potential applications. The goal of this project was to develop a technique for characterizing high-field laser-plasma interactions with femtosecond resolution based on the direct measurement of the phase change of an optical pulse. The authors developed the technique of Multi-pulse Interferometric Frequency Resolved Optical Gating (MI-FROG), which recovers (to all orders) the phase difference between pumped and unpumped probe pulses, enabling the determination of sub-pulsewidth time-resolved phase and frequency shifts impressed by a pump pulse on a weak probe pulse. Using MI-FROG, the authors obtained the first quantitative measurements of high-field ionization rates in noble gases and diatomic molecules. They obtained agreement between the measured ionization rates an d those calculated for the noble gases and diatomic nitrogen and hydrogen using a one-dimensional fluid model and rates derived from tunneling theory. However, much higher rates are measured for diatomic oxygen than predicted by tunneling theory calculations.

  9. Ternary bulk heterojunction solar cells: addition of soluble NIR dyes for photocurrent generation beyond 800 nm.

    PubMed

    Lim, Bogyu; Bloking, Jason T; Ponec, Andrew; McGehee, Michael D; Sellinger, Alan

    2014-05-14

    The incorporation of a tert-butyl-functionalized silicon 2,3-naphthalocyanine bis(trihexylsilyloxide) dye molecule as a third component in a ternary blend bulk heterojunction (BHJ) organic solar cell containing P3HT (donor) and PC60BM (acceptor) results in increased NIR absorption. This absorption yields an increase of up to 40% in the short-circuit current and up to 19% in the power conversion efficiency (PCE) in photovoltaic devices. Two-dimensional grazing incidence wide-angle X-ray scattering (2-D GIWAXS) experiments show that compared to the unfunctionalized dye the tert-butyl functionalization enables an increase in the volume fraction of the dye molecule that can be incorporated before the device performance decreases. Quantum efficiency and absorption spectra also indicate that, at dye concentrations above about 8 wt %, there is an approximately 30 nm red shift in the main silicon naphthalocyanine absorption peak, allowing further dye addition to contribute to added photocurrent. This peak shift is not observed in blends with unfunctionalized dye molecules, however. This simple approach of using ternary blends may be generally applicable for use in other unoptimized BHJ systems towards increasing PCEs beyond current levels. Furthermore, this may offer a new approach towards OPVs that absorb NIR photons without having to design, synthesize, and purify complicated donor-acceptor polymers.

  10. Super-achromatic microprobe for ultrahigh-resolution endoscopic OCT imaging at 800 nm (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Yuan, Wu; Alemohammad, Milad; Yu, Xiaoyun; Yu, Shaoyong; Li, Xingde

    2016-03-01

    In this paper, we report a super-achromatic microprobe made with fiber-optic ball lens to enable ultrahigh-resolution endoscopic OCT imaging. An axial resolution of ~2.4 µm (in air) can be achieved with a 7-fs Ti:Sapphire laser. The microprobe has minimal astigmatism which affords a high transverse resolution of ~5.6 µm. The miniaturized microprobe has an outer diameter of ~520 µm including the encasing metal guard and can be used to image small luminal organs. The performance of the ultrahigh-resolution OCT microprobe was demonstrated by imaging rat esophagus, guinea pig esophagus, and mouse rectum in vivo.

  11. Through-skull vasculature assessment using fluorescence brain imaging on murine models at around 800 nm

    NASA Astrophysics Data System (ADS)

    Le, Hanh N. D.; Gau, Yung-Tian A.; Rahmim, Arman; Wong, Dean F.; Bergles, Dwight E.; Kang, Jin U.

    2017-02-01

    We describe a scanning near-infrared fluorescence imager for through-skull non-invasive brain imaging on live murine models. The captured photoluminescence feature through scattering media was enhanced using a high sensitivity scientific CMOS sensor with the obtained spatial resolution of 15.63 μm, depth of field of 5 mm and an average local signal-to-noise ratio of 37.5 dB.

  12. Optical diameters of stars measured with the Mt. Wilson Mark III interferometer

    NASA Technical Reports Server (NTRS)

    Simon, R. S.; Mozurkewich, D.; Johnston, K. J.; Gaume, Ralph; Hutter, D. J.; Bowers, P. F.; Colavita, M. M.; Shao, M.

    1990-01-01

    Reliable stellar angular diameters can now be determined using the Mark III Optical Interferometer located on Mt. Wilson, California. The Mark III is a Michelson Interferometer capable of measuring the interferometric fringe visibility for stars using interferometer baselines varying from 3 to 31.5 meters in length. Angular diameters measured with the Mark III Optical Interferometer are presented for 12 stars at wavelengths of 450 and 800 nm.

  13. Characterization of nonlinear properties of black phosphorus nanoplatelets with femtosecond pulsed Z-scan measurements.

    PubMed

    Zheng, Xin; Chen, Runze; Shi, Gang; Zhang, Jianwei; Xu, Zhongjie; Cheng, Xiang'ai; Jiang, Tian

    2015-08-01

    The nonlinear properties of black phosphorus (BP) nanoplatelets (NPs) have been characterized with Z-scan measurements under 800-nm femtosecond pulsed laser excitation. A transition from saturable absorption (SA) to reverse saturable absorption (RSA) with the increase of laser intensity was observed in the open-aperture (OA) measurements. Simultaneously, closed-aperture (CA) measurements were carried out to investigate the nonlinear refractive index of BP NPs together, and a value of n(2) ≃(6.8±0.2)×10(-13) m2/W was obtained. The nonlinear absorption properties were analyzed according to the band structure of BP. A theoretical analysis based on SA and two-photon absorption (TPA) was used to determine the nonlinear absorption coefficients from the experimental results, and the TPA coefficient at 800 nm was estimated about (4.5±0.2)×10(-10) m/W.

  14. Note: Fiber optic transport probe for Hall measurements under light and magnetic field at low temperatures: Case study of a two dimensional electron gas

    SciTech Connect

    Bhadauria, P. P. S.; Gupta, Anurag; Kumar, Pramod; Dogra, Anjana; Budhani, R. C.

    2015-05-15

    A fiber optic based probe is designed and developed for electrical transport measurements in presence of quasi-monochromatic (360–800 nm) light, varying temperature (T = 1.8–300 K), and magnetic field (B = 0–7 T). The probe is tested for the resistivity and Hall measurements performed on a LaAlO{sub 3}–SrTiO{sub 3} heterointerface system with a conducting two dimensional electron gas.

  15. Measurement of birefringence inside a filament

    SciTech Connect

    Yuan Shuai; Wang, Tie-Jun; Chin, See Leang; Kosareva, Olga; Panov, Nikolay; Makarov, Vladimir; Zeng Heping

    2011-07-15

    We quantified the ultrafast birefringence induced in the filament in an atomic gas by measuring the filament-induced polarization rotation of a probe pulse. Based on the dephasing of the probe's orthogonal polarization components in argon, the experiment was done at 1 atm by copropagating a linearly polarized 400-nm probe pulse with an 800-nm pump pulse which generated the filament. The probe's elliptical polarization states were shown under various initial pump-probe polarization schemes. These states were verified by comparing the filament-induced probe polarization rotation angle and the ellipticity of the probe polarization.

  16. Measurements of multiphoton action cross sections for multiphoton microscopy

    PubMed Central

    Cheng, Li-Chung; Horton, Nicholas G.; Wang, Ke; Chen, Shean-Jen; Xu, Chris

    2014-01-01

    We report quantitative measurements of two-, three-, and four-photon excitation action cross sections of several commonly used fluorophores and fluorescent proteins at three different excitation wavelengths of 800 nm, 1300 nm, and 1680 nm. The measured cross section values are consistent with simple quantum mechanic estimations. These values indicate that the optimum repetition rate for deep tissue 3-photon microscopy is approximately 1 to 2 MHz. We further demonstrate that it is feasible to perform 4-photon fluorescence microscopy of GFP labeled microglia in mouse brain in vivo at 1700 nm. 4-photon excitation increases the accessibility of fluorophores at the long wavelength spectral window of 1700 nm. PMID:25360361

  17. Broadband optical parametric chirped pulse amplification in K3B6O10Br crystal near 800 nm

    NASA Astrophysics Data System (ADS)

    Liu, Xiaodi; Xu, Lu; Zhang, Min; Pan, Shilie; Liang, Xiaoyan

    2017-09-01

    Broadband optical parametric chirped pulse amplification (OPCPA) of the K3B6O10Br (KBOB) crystal at a central wavelength of 800 nm has been demonstrated for the first time. Using type-1 non-collinear phase matching, a 52 nm FWHM bandwidth was achieved around 800 nm. The 0.25 mJ signal was amplified to 23.92 mJ at the pump intensity of 2.1 GW cm-2. The energy gain was 95.68. After compression, 15.31 mJ to 31.9 fs pulses were obtained. The results confirm that KBOB crystal is a potential alternative for efficient, broadband OPCPA near 800 nm.

  18. Ultrahigh-resolution robust needle probe for high-speed interstitial OCT imaging at 800 nm (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Yuan, Scott Wu; Li, Xingde

    2017-02-01

    We report an anastigmatic needle probe made with fiber-optic ball lens for high-speed circumferential interstitial OCT imaging. The anastigmatic design affords a high transverse resolution of 11.9 µm. The improved mechanical design enables a robust circumferential scanning speed up to 26.8 frames per second. The miniaturized needle probe has an outer diameter of 620 µm including the encasing metal guard and glass microcapillary. The performance of the anastigmatic OCT needle was demonstrated by imaging rat belly tissues and rat liver ex vivo with a 1300-nm swept-source OCT (SSOCT) system. The preliminary results suggest the potential of the needle probe for minimally invasive interstitial imaging and image-guided biopsy.

  19. Contactless thickness measurement of micromachined silicon sensors with transmitted infrared light

    NASA Astrophysics Data System (ADS)

    Samek, Norbert E.

    Relative transmission of infrared light has been used to measure thickness of micromachined silicon diaphragm sensors. The transmission was measured on an infrared microscope equipped with a water cooled illuminator and with 800 nm and 900 nm narrow band pass filters. Calibration tests were made by plotting the output of a photodetector on a 0 to 100 scale against the thickness of the sensors measured with an electronic dial gage. The results are compared against theoretical relative transmission curves. Factors affecting accuracy and the measuring error band are discussed.

  20. Measuring spatiotemporal intensity-and-phase complexity of multimode fiber output pulses

    NASA Astrophysics Data System (ADS)

    Guang, Zhe; Rhodes, Michelle; Trebino, Rick

    2016-03-01

    We demonstrate ultrashort pulse spatiotemporal field measurement for multimode optical fibers, using a singleframe characterization technique, called Spatially and Temporally Resolved Intensity and Phase Evaluation Device: Full Information from a Single Hologram (STRIPED FISH). We measure STRIPED FISH traces and retrieve the pulse field E(x,y,t) or equivalently E(x,y,ω), to generate movies revealing the field structure induced by propagating modes, due to their differences in field spatial distribution, modal propagation velocity and modal dispersion inside the fiber. We launch femtosecond pulses near 800nm from Ti: Sapphire laser to investigate linearly polarized modes LP01, LP11, LP02 and LP21 in multimode fibers.

  1. Planned Efficiency Measurements of STIRAP

    NASA Astrophysics Data System (ADS)

    Zakharov, Vladislav; McKenna, Casey; Yuan, Deqian; Gasparik, Jessica; Metcalf, Harold

    2015-05-01

    Our measurements of the absolute efficiency of using STIRAP to populate Rydberg states of He have been limited by the Doppler detuning associated with the divergence of the atomic beam that crosses perpendicular to our laser beams. The limitation is exacerbated when both laser beams co-propagate, compounding these Doppler shifts. We plan to have them counter-propagate and thereby ameliorate this effect. He 23S atoms in a LN2 temperature thermal beam are coupled to the 33P state by λ = 389 nm light (blue), and that state is coupled to Rydberg states by ~ 800 nm (red) light. The anti-parallel laser beams are arranged so that the atoms encounter the red light first (counter-intuitive order for STIRAP) partially overlapping with the blue. We have observed interference among the atomic transitions by varying the light polarization, and are planning further studies concerning these internal atomic interferometry phenomena. Supported by ONR and Dept. of Education GAANN.

  2. Traceability of spectroradiometric measurements of multiport UV solar simulators

    NASA Astrophysics Data System (ADS)

    Dai, Cai-hong; Wu, Zhi-feng; Qi, Xiao-jin; Ye, Jing; Chen, Bin-hua

    2013-08-01

    A special multiport UV solar simulator was designed at National Institute of Metrology (NIM), and a set of UVA and UVA+B optical filters were developed to satisfy the spectral distribution specifications of COLIPA SPF and JCIA Persistent Pigmentation Darkening (PPD) test methods. The other purpose of this apparatus is used to calibrate the UVA and UVA+B irradiance or dose of broadband UV radiometers. The response of a double grating spectroradiometer with a 5.8 mm entrance aperture from 250nm to 800nm was calibrated using a 1000W spectral irradiance standard lamp at a distance of 500 mm, and the value of quantities of the developed system is traceable to the national primary standard of spectral irradiance of NIM. The system wavelength was checked using a low-pressure mercury lamp. The spectral response of each port was measured from 250nm to 800nm in 1nm steps. Experiment results showed that the percentage relative cumulative erythemal effectiveness (% RCEE) and UVA measurement waveband values of the multiport UV solar simulator are within the specified limits. The source spectrum is smooth and continuous, and the energy below 290nm is less than 0.1%.

  3. Measuring the temporal coherence of a high harmonic generation setup employing a Fourier transform spectrometer for the VUV/XUV

    NASA Astrophysics Data System (ADS)

    Terschlüsen, J. A.; Agåker, M.; Svanqvist, M.; Plogmaker, S.; Nordgren, J.; Rubensson, J.-E.; Siegbahn, H.; Söderström, J.

    2014-12-01

    In this experiment we used an 800 nm laser to generate high-order harmonics in a gas cell filled with Argon. Of those photons, a harmonic with 42 eV was selected by using a time-preserving grating monochromator. Employing a modified Mach-Zehnder type Fourier transform spectrometer for the VUV/XUV it was possible to measure the temporal coherence of the selected photons to about 6 fs. We demonstrated that not only could this kind of measurement be performed with a Fourier transform spectrometer, but also with some spatial resolution without modifying the XUV source or the spectrometer.

  4. Measurement of Scattering Cross Section with a Spectrophotometer with an Integrating Sphere Detector.

    PubMed

    Gaigalas, A K; Wang, Lili; Karpiak, V; Zhang, Yu-Zhong; Choquette, Steven

    2012-01-01

    A commercial spectrometer with an integrating sphere (IS) detector was used to measure the scattering cross section of microspheres. Analysis of the measurement process showed that two measurements of the absorbance, one with the cuvette placed in the normal spectrometer position, and the second with the cuvette placed inside the IS, provided enough information to separate the contributions from scattering and molecular absorption. Measurements were carried out with microspheres with different diameters. The data was fitted with a model consisting of the difference of two terms. The first term was the Lorenz-Mie (L-M) cross section which modeled the total absorbance due to scattering. The second term was the integral of the L-M differential cross section over the detector acceptance angle. The second term estimated the amount of forward scattered light that entered the detector. A wavelength dependent index of refraction was used in the model. The agreement between the model and the data was good between 300 nm and 800 nm. The fits provided values for the microsphere diameter, the concentration, and the wavelength dependent index of refraction. For wavelengths less than 300 nm, the scattering cross section had significant spectral structure which was inversely related to the molecular absorption. This work addresses the measurement and interpretation of the scattering cross section for wavelengths between 300 nm and 800 nm.

  5. Measurement of Scattering Cross Section with a Spectrophotometer with an Integrating Sphere Detector

    PubMed Central

    Gaigalas, A. K.; Wang, Lili; Karpiak, V.; Zhang, Yu-Zhong; Choquette, Steven

    2012-01-01

    A commercial spectrometer with an integrating sphere (IS) detector was used to measure the scattering cross section of microspheres. Analysis of the measurement process showed that two measurements of the absorbance, one with the cuvette placed in the normal spectrometer position, and the second with the cuvette placed inside the IS, provided enough information to separate the contributions from scattering and molecular absorption. Measurements were carried out with microspheres with different diameters. The data was fitted with a model consisting of the difference of two terms. The first term was the Lorenz-Mie (L-M) cross section which modeled the total absorbance due to scattering. The second term was the integral of the L-M differential cross section over the detector acceptance angle. The second term estimated the amount of forward scattered light that entered the detector. A wavelength dependent index of refraction was used in the model. The agreement between the model and the data was good between 300 nm and 800 nm. The fits provided values for the microsphere diameter, the concentration, and the wavelength dependent index of refraction. For wavelengths less than 300 nm, the scattering cross section had significant spectral structure which was inversely related to the molecular absorption. This work addresses the measurement and interpretation of the scattering cross section for wavelengths between 300 nm and 800 nm. PMID:26900524

  6. Measurement of nonlinear optical refraction of composite material based on sapphire with silver by Kerr-lens autocorrelation method.

    PubMed

    Yu, Xiang-xiang; Wang, Yu-hua

    2014-01-13

    Silver nanoparticles synthesized in a synthetic sapphire matrix were fabricated by ion implantation using the metal vapor vacuum arc ion source. The optical absorption spectrum of the Ag: Al2O3 composite material has been measured. The analysis of the supercontinuum spectrum displayed the nonlinear refractive property of this kind of sample. Nonlinear optical refraction index was identified at 800 nm excitation using the Kerr-lens autocorrelation (KLAC) technique. The spectrum showed that the material possessed self-defocusing property (n(2) = -1.1 × 10(-15) cm(2)W). The mechanism of nonlinear refraction has been discussed.

  7. Z-scan measurement of the nonlinear refractive index of Nd(3+), Y(3+)-codoped CaF(2) and SrF(2) crystals.

    PubMed

    Guo, Yue; Lu, Shunbin; Su, Liangbi; Zhao, Chujun; Zhang, Han; Wen, Shuangchun

    2015-02-01

    By performing the Z-scan measurements at 800 nm using a femtosecond pulsed laser, we are able to characterize the nonlinear refractive indices of Nd, Y codoped CaF(2) and SrF(2) crystals. Based on our measured results, we conclude that the doped fluoride crystal possesses a small nonlinear refractive index and the doping of Nd(3+) and Y(3+) ions in CaF(2) can change its third-order nonlinear index, but the contribution is minor. The doped fluoride crystal may have large potential to be developed as the next generation of gain material for a high-energy laser system.

  8. Wavelength selection in measuring red blood cell aggregation based on light transmittance.

    PubMed

    Uyuklu, Mehmet; Canpolat, Murat; Meiselman, Herbert J; Baskurt, Oguz K

    2011-11-01

    The reversible aggregation of red blood cells (RBC) is of current basic science and clinical interest. Using a flow channel and light transmittance (LT) through RBC suspensions, we have examined the effects of wavelength (500 to 900 nm) on the static and dynamic aspects of RBC aggregation for normal blood and suspensions with reduced or enhanced aggregation; the effects of oxygenation were also explored. Salient observations include: 1. significant effects of wavelength on aggregation parameters reflecting the extent of aggregation (i.e., number of RBC per aggregate); 2. no significant effects of wavelength on parameters reflecting the time course of RBC aggregation; 3. a prominent influence of hemoglobin oxygen saturation on both extent and time-course related aggregation parameters measured at wavelengths less than 700 nm, but only on the time-course at 800 nm; and 4. the power of parameters in detecting a given alteration of RBC aggregation is affected by wavelength, in general being greater at higher wavelengths. It is recommended that light sources with wavelengths around 800 nm be used in instruments for measuring RBC aggregation via LT.

  9. Wavelength selection in measuring red blood cell aggregation based on light transmittance

    NASA Astrophysics Data System (ADS)

    Uyuklu, Mehmet; Canpolat, Murat; Meiselman, Herbert J.; Baskurt, Oguz K.

    2011-11-01

    The reversible aggregation of red blood cells (RBC) is of current basic science and clinical interest. Using a flow channel and light transmittance (LT) through RBC suspensions, we have examined the effects of wavelength (500 to 900 nm) on the static and dynamic aspects of RBC aggregation for normal blood and suspensions with reduced or enhanced aggregation; the effects of oxygenation were also explored. Salient observations include: 1. significant effects of wavelength on aggregation parameters reflecting the extent of aggregation (i.e., number of RBC per aggregate); 2. no significant effects of wavelength on parameters reflecting the time course of RBC aggregation; 3. a prominent influence of hemoglobin oxygen saturation on both extent and time-course related aggregation parameters measured at wavelengths less than 700 nm, but only on the time-course at 800 nm; and 4. the power of parameters in detecting a given alteration of RBC aggregation is affected by wavelength, in general being greater at higher wavelengths. It is recommended that light sources with wavelengths around 800 nm be used in instruments for measuring RBC aggregation via LT.

  10. Wavelength selection in measuring red blood cell aggregation based on light transmittance

    PubMed Central

    Uyuklu, Mehmet; Canpolat, Murat; Meiselman, Herbert J.; Baskurt, Oguz K.

    2011-01-01

    The reversible aggregation of red blood cells (RBC) is of current basic science and clinical interest. Using a flow channel and light transmittance (LT) through RBC suspensions, we have examined the effects of wavelength (500 to 900 nm) on the static and dynamic aspects of RBC aggregation for normal blood and suspensions with reduced or enhanced aggregation; the effects of oxygenation were also explored. Salient observations include: 1. significant effects of wavelength on aggregation parameters reflecting the extent of aggregation (i.e., number of RBC per aggregate); 2. no significant effects of wavelength on parameters reflecting the time course of RBC aggregation; 3. a prominent influence of hemoglobin oxygen saturation on both extent and time-course related aggregation parameters measured at wavelengths less than 700 nm, but only on the time-course at 800 nm; and 4. the power of parameters in detecting a given alteration of RBC aggregation is affected by wavelength, in general being greater at higher wavelengths. It is recommended that light sources with wavelengths around 800 nm be used in instruments for measuring RBC aggregation via LT. PMID:22112138

  11. Oxygen measurements via phosphorescence.

    PubMed

    Shaban, Sami; Marzouqi, Farida; Al Mansouri, Aysha; Penefsky, Harvey S; Souid, Abdul-Kader

    2010-12-01

    Accurate measurements of dissolved O(2) as a function of time have numerous chemical and biological applications. The Pd (II) complex of meso-tetra-(4-sulfonatophenyl)-tetrabenzoporphyrin (Pd phosphor) was used for this purpose. Detection is based on the principle that the phosphorescence of this oxygen probe is inversely related to dissolved O(2) (O(2) quenches the phosphorescence). Biologic samples containing the Pd phosphor were flashed (10/s) with a peak output of 625nm; emitted light was detected at 800nm. Amplified pulses of phosphorescence were digitized at 1-2MHz using an analog/digital converter (PCI-DAS 4020/12 I/O Board) with outputs ranging from 1 to 20MHz. Assessment revealed a customized program was necessary. Pulses were captured using a developed software at 0.1-4MHz, depending on the speed of the computer. O(2) concentration was calculated by fitting to an exponential the decay of the phosphorescence. Twelve tasks were identified, which allowed full control and customization of the data acquisition, storage and analysis. The program used Microsoft Visual Basic 6 (VB6), Microsoft Access Database 2007, and a Universal Library component that allowed direct reading from the PCI-DAS 4020/12 I/O Board. It involved a relational database design to store experiments, pulses and pulse metadata, including phosphorescence decay rates. The method permitted reliable measurements of cellular O(2) consumption over several hours. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  12. EXPERIMENTAL MEASUREMENTS OF THE ORION PHOTOINJECTOR DRIVE LASER OSCILLATOR SUBSYSTEM

    SciTech Connect

    Akre, Ronald A.

    2003-05-14

    Timing jitter measurements have been conducted on the ORION photoinjector laser oscillator pulse train output with respect to a ultra low noise crystal rf oscillator running at 79 1/3 MHz, the 36th harmonic of S-Band. The ORION laser oscillator subsystem consists of a Spectra-Physics Tsunami ultra-fast tunable (750-850nm) laser pumped by a Diode pumped Spectra-Physics Millennia VsP 5W. Overall laser oscillator subsystem performance will be presented. These measurements consist of the laser oscillator generated noise and transfer function from the RF reference input of the laser to an external photodiode RF output. Timing jitter measurements of less than 500 fsec have been attained with the laser oscillator tuned to 800 nm.

  13. Receiver performance of laser ranging measurements between the Lunar Observer and a subsatellite for lunar gravity studies

    NASA Technical Reports Server (NTRS)

    Davidson, Frederic M.; Sun, Xiaoli

    1992-01-01

    The optimal receiver for a direct detection laser ranging system for slow Doppler frequency shift measurement is shown to consist of a phase tracking loop which can be implemented approximately as a phase lock loop with a 2nd or 3rd order loop filter. The laser transmitter consists of an AlGaAs laser diode at a wavelength of about 800 nm and is intensity modulated by a sinewave. The receiver performance is shown to be limited mainly by the preamplifier thermal noise when a silicon avalanche photodiode is used. A high speed microchannel plate photomultiplier tube is shown to outperform a silicon APD despite its relatively low quantum efficiency at wavelengths near 800 nm. The maximum range between the Lunar Observer and the subsatellite for lunar gravity studies is shown to be about 620 km when using a state-of-the-art silicon APD and about 1000 km when using a microchannel plate photomultiplier tube in order to achieve a relative velocity measurement accuracy of 1 millimeter per second. Other parameters such as the receiver time base jitter and drift also limit performance and have to be considered in the design of an actual system.

  14. Chiral cavity ring down polarimetry: Chirality and magnetometry measurements using signal reversals.

    PubMed

    Bougas, Lykourgos; Sofikitis, Dimitris; Katsoprinakis, Georgios E; Spiliotis, Alexandros K; Tzallas, Paraskevas; Loppinet, Benoit; Rakitzis, T Peter

    2015-09-14

    We present the theory and experimental details for chiral-cavity-ring-down polarimetry and magnetometry, based on ring cavities supporting counterpropagating laser beams. The optical-rotation symmetry is broken by the presence of both chiral and Faraday birefringence, giving rise to signal reversals which allow rapid background subtractions. We present the measurement of the specific rotation at 800 nm of vapors of α-pinene, 2-butanol, and α-phellandrene, the measurement of optical rotation of sucrose solutions in a flow cell, the measurement of the Verdet constant of fused silica, and measurements and theoretical treatment of evanescent-wave optical rotation at a prism surface. Therefore, these signal-enhancing and signal-reversing methods open the way for ultrasensitive polarimetry measurements in gases, liquids and solids, and at surfaces.

  15. Chiral cavity ring down polarimetry: Chirality and magnetometry measurements using signal reversals

    SciTech Connect

    Bougas, Lykourgos; Sofikitis, Dimitris; Katsoprinakis, Georgios E.; Spiliotis, Alexandros K.; Rakitzis, T. Peter; Tzallas, Paraskevas; Loppinet, Benoit

    2015-09-14

    We present the theory and experimental details for chiral-cavity-ring-down polarimetry and magnetometry, based on ring cavities supporting counterpropagating laser beams. The optical-rotation symmetry is broken by the presence of both chiral and Faraday birefringence, giving rise to signal reversals which allow rapid background subtractions. We present the measurement of the specific rotation at 800 nm of vapors of α-pinene, 2-butanol, and α-phellandrene, the measurement of optical rotation of sucrose solutions in a flow cell, the measurement of the Verdet constant of fused silica, and measurements and theoretical treatment of evanescent-wave optical rotation at a prism surface. Therefore, these signal-enhancing and signal-reversing methods open the way for ultrasensitive polarimetry measurements in gases, liquids and solids, and at surfaces.

  16. Measurements of scattering and absorption in mammalian cell suspensions

    SciTech Connect

    Mourant, J.R.; Johnson, T.M.; Freyer, J.P.

    1996-03-01

    During the past several years a range of spectroscopies, including fluorescence and elastic-scatter spectroscopy, have been investigated for optically based detection of cancer and other tissue pathologies. Both elastic-scatter and fluorescence signals depend, in part, on scattering and absorption properties of the cells in the tissue. Therefore an understanding of the scattering and absorption properties of cells is a necessary prerequisite for understanding and developing these techniques. Cell suspensions provide a simple model with which to begin studying the absorption and scattering properties of cells. In this study we have made preliminary measurements of the scattering and absorption properties of suspensions of mouse mammary carcinoma cells (EMT6) over a broad wavelength range (380 nm to 800 nm).

  17. Discrimination of atherosclerotic plaque constituents based on local measurements of optical attenuation coefficents by OCT

    NASA Astrophysics Data System (ADS)

    van der Meer, Freek J.; Perree, Jop; Faber, Dirk J.; Baraznji Sassoon, David M.; Aalders, Maurice C. G.; van Leeuwen, Ton G.

    2005-04-01

    Imaging of human autopsy samples was performed from the luminal side with a high (3.5 μm axial and 7 μm lateral) resolution OCT system (around 800 nm) or a regular (15-20 μm axial and 20 μm lateral resolution) OCT system (around 1300 nm). For each sample, dimensions were measured by histomorphometry and OCT and the optical attenuation was measured. Quantitative analysis showed a strong and significant correlation between OCT and histology cap thickness measurements for both OCT systems. For both systems, the measured attenuation coefficients of diffuse intimal thickening and lipid-rich regions differed significantly from media and calcifications. Both the high and regular resolution OCT systems can precisely image the atherosclerotic plaques. Quantitative analysis of the OCT signals allowed in situ determination of the intrinsic optical attenuation coefficient of atherosclerotic tissue components within regions of interest, which can further help to discriminate the plaque and arterial wall components.

  18. Discrimination of atherosclerotic plaque constituents based on local measurements of optical attenuation coefficients by OCT

    NASA Astrophysics Data System (ADS)

    van der Meer, Freek J.; Perree, Jop; Faber, Dirk J.; Baraznji Bassoon, David M.; Aalders, Maurice C. G.; van Leeuwen, Ton G.

    2005-04-01

    Imaging of human autopsy samples was performed from the luminal side with a high (3.5 μm axial and 7 μm lateral) resolution OCT system (around 800 nm) or a regular (15-20 μm axial and 20 μm lateral resolution) OCT system (around 1300 nm). For each sample, dimensions were measured by histomorphometry and OCT and the optical attenuation was measured. Quantitative analysis showed a strong and significant correlation between OCT and histology cap thickness measurements for both OCT systems. For both systems, the measured attenuation coefficients of diffuse intimal thickening and lipid-rich regions differed significantly from media and calcifications. Both the high and regular resolution OCT systems can precisely image the atherosclerotic plaques. Quantitative analysis of the OCT signals allowed in situ determination of the intrinsic optical attenuation coefficient of atherosclerotic tissue components within regions of interest, which can further help to discriminate the plaque and arterial wall components.

  19. Generation of Terahertz Radiation from Fe-doped InGaAsP Using 800 nm to 1550 nm Pulsed Laser Excitation

    NASA Astrophysics Data System (ADS)

    Hatem, O.; Freeman, J. R.; Cunningham, J. E.; Cannard, P. J.; Robertson, M. J.; Linfield, E. H.; Davies, A. G.; Moodie, D. G.

    2016-05-01

    We demonstrate efficient generation of terahertz (THz) frequency radiation by pulsed excitation, at wavelengths between 800 and 1550 nm, of photoconductive (PC) switches fabricated using Fe-doped InGaAsP wafers, grown by metal organic chemical vapor deposition (MOCVD). Compared to our previous studies of Fe-doped InGaAs wafers, Fe:InGaAsP wafers exhibited five times greater dark resistivity to give a value of 10 kΩ cm, and Fe:InGaAsP PC switches produced five times higher THz power emission. The effect of Fe-doping concentration (between 1E16 and 1.5E17 cm-3) on optical light absorption (between 800 and 1600 nm), on resistivity, and on THz emission is also discussed.

  20. A Remote Sensing Technique For Combustion Gas Temperature Measurement In Black Liquor Recovery Boilers

    NASA Astrophysics Data System (ADS)

    Charagundla, S. R.; Semerjian, H. G.

    1986-10-01

    A remote sensing technique, based on the principles of emission spectroscopy, is being developed for temperature measurements in black liquor recovery boilers. Several tests have been carried out, both in the laboratory and at a number of recovery boilers, to characterize the emission spectra in the wavelength range of 300 nm to 800 nm. These tests have pointed out the potential for temperature measurements using the line intensity ratio technique based on a pair of emission lines at 404.4 nm and 766.5 nm observed in the recovery boiler combustion zone; these emission lines are due to potassium, a common constituent found in all the black liquors. Accordingly, a fiber optics based four-color system has been developed. This in-situ, nonintrusive temperature measurement technique, together with some of the more recent results, is described in this paper.

  1. Measuring of urban ultrafine aerosol as a part of regular air pollution monitoring activities

    NASA Astrophysics Data System (ADS)

    Hejkrlík, Libor; Plachá, Helena

    2015-04-01

    Number size distribution of UFP has been measured since June 2012 to present time (end of 2014) at a background urban site in Northern Bohemia in the frame of UltraSchwarz Project. The project sustainability guarantees at least five years further measuring thus this highly specific activity already becomes part of existing air pollution monitoring system of Czech Hydrometeorological Institute. Number concentrations of UFP were measured by SMPS in a diameter range of 10 to 800 nm in 7 channels with time resolution of 10 minutes. For the purposes of this study the data were re-arranged into series of one-hour means in three size categories: nucleation mode (10-30 nm), Aitken mode (30-100 nm) and accumulation mode (100-800 nm). At the same measuring site 7 other air pollutants (PM1-BC, NO, NOX, NO2, O3, PM10 and SO2) were measured with identical time resolution. The successive daily courses of submicron particles in three size modes as well as of seven other ambient air pollutants were drawn in the form of 3D surface diagrams expressing different behavior of specific substances in the course of 26 months of continuous measuring campaign, allowing for analysis of both diurnal and seasonal changes. The three modes of UFP manifest diverse pictures, the nucleation mode is apparent mainly during warm seasons, the particles in Aitken mode behave rather indifferently to the period of the year and the accumulation mode has close relationship to coarse particles. Month by month correlation analysis indicate that nucleation mode nanoparticles are positively correlated especially with increasing O3 and SO2 concentration and that there exists connection between Aitken and accumulation modes and nitrogen oxides. In order to better understand fine time patterns we plan to calculate moving correlation indices over shorter time periods. Good idea would also be to make use of large database of data from nearby stations of CHMI to analyze the role of meteorological conditions.

  2. Development of polymer lab-on-a-chip (LOC) for oxidation-reduction potential (ORP) measurement.

    PubMed

    Jang, A; Lee, K K; Bishop, P L; Kim, I S; Ahn, C H

    2011-01-01

    Reverse osmosis (RO) desalination has been recognized as a promising method to solve the water shortage problem. Nevertheless, since it is energy intensive and has many problems associated with biofouling/fouling of RO membranes in RO plants, its commercial acceptance is still slow. Especially, as high levels of oxidizing agents negatively affect RO membrane efficiency and life span. So, there is a need to develop sensitive, selective, portable and rapid methods to determine oxidation-reduction potential (ORP) in feed solution. For developing a polymer ORP lab-on-a-chip (LOC), a microchannel patterned on a polymer substrate was successfully filled with 800 nm diameter silica beads using self-assembly bead packing technology. The measured ORPs using the three kinds of redox potential solutions were typically slightly lower than those of the nominal redox potential. But, all of the measurements should be deemed acceptable. The ORP LOC has also a much shorter response time than the conventional potentiometric sensor.

  3. In-vivo reflection spectroscopy measurements in pig brain during stereotactic surgery

    NASA Astrophysics Data System (ADS)

    Antonsson, Johan; Eriksson, Ola; Wardell, Karin

    2003-07-01

    Radio frequency (RF) lesioning in the human brain is a common surgical therapy for relieving severe pain as well as for movement disorders such as Parkinsonia. During the procedure a small electrode is introduced by stereotactic means towards a target area localized by CT or MRI. An RF-current is applied through the electrode tip when positioned in the target area. The tissue in the proximity of the tip is heated by the current and finally coagulated. The overall aim of this study was to improve the RF-technique and its ability to estimate lesion size by means of optical methods. Therefore, the optical differences between white and gray matter, as well as lesioned and unlesioned tissue were investigated. Reflection spectroscopy measurements in the range of 450-800 nm were conducted on fully anesthetized pigs during stereotactic RF-lesioning (n=6). Light from a tungsten lamp was guided to the electrode tip through optical fibers, inserted along a 2 mm in diameter monopolar RF-electrode. Measurements were performed in steps of 0-10 mm from the target in each hemisphere towards the entry point of the skull. In the central gray of the porcine brain measurements were performed both before and after the creation of a lesion. A total of 55 spectra were collected during this study. Correlation to tissue type was done using post-operative MR-images. The spectral signature for white and gray matter differs significantly for the entire spectral range of 450-800 nm. Pre- and post-lesioning reflection spectroscopy showed the largest differences below 600 and above 620 nm, which implies that lasers within this wavelength range may be useful for in-vivo measurements of tissue optical changes during RF-lesioning.

  4. Optoelectronic measurement of x-ray synchrotron pulses: A proof of concept demonstration

    NASA Astrophysics Data System (ADS)

    Durbin, Stephen M.; Mahmood, Aamer; Caffee, Marc; Savikhin, Sergei; Dufresne, Eric M.; Wen, Haidan; Li, Yuelin

    2013-02-01

    Optoelectronic detection using photoconductive coplanar stripline devices has been applied to measuring the time profile of x-ray synchrotron pulses, a proof of concept demonstration that may lead to improved time-resolved x-ray studies. Laser sampling of current vs time delay between 12 keV x-ray and 800 nm laser pulses reveal the ˜50 ps x-ray pulse width convoluted with the ˜200 ps lifetime of the conduction band carriers. For GaAs implanted with 8 MeV protons, a time profile closer to the x-ray pulse width is observed. The protons create defects over the entire depth sampled by the x-rays, trapping the x-ray excited conduction electrons and minimizing lifetime broadening of the electrical excitation.

  5. Optoelectronic measurement of x-ray synchrotron pulses: A proof of concept demonstration

    SciTech Connect

    Durbin, Stephen M.; Caffee, Marc; Savikhin, Sergei; Mahmood, Aamer; Dufresne, Eric M.; Wen, Haidan; Li, Yuelin

    2013-02-04

    Optoelectronic detection using photoconductive coplanar stripline devices has been applied to measuring the time profile of x-ray synchrotron pulses, a proof of concept demonstration that may lead to improved time-resolved x-ray studies. Laser sampling of current vs time delay between 12 keV x-ray and 800 nm laser pulses reveal the {approx}50 ps x-ray pulse width convoluted with the {approx}200 ps lifetime of the conduction band carriers. For GaAs implanted with 8 MeV protons, a time profile closer to the x-ray pulse width is observed. The protons create defects over the entire depth sampled by the x-rays, trapping the x-ray excited conduction electrons and minimizing lifetime broadening of the electrical excitation.

  6. Electron Bunch Length Measurements from Laser-Accelerated Electrons Using Single-Shot THz Time-Domain Interferometry

    NASA Astrophysics Data System (ADS)

    Debus, A. D.; Bussmann, M.; Schramm, U.; Sauerbrey, R.; Murphy, C. D.; Major, Zs.; Hörlein, R.; Veisz, L.; Schmid, K.; Schreiber, J.; Witte, K.; Jamison, S. P.; Gallacher, J. G.; Jaroszynski, D. A.; Kaluza, M. C.; Hidding, B.; Kiselev, S.; Heathcote, R.; Foster, P. S.; Neely, D.; Divall, E. J.; Hooker, C. J.; Smith, J. M.; Ertel, K.; Langley, A. J.; Norreys, P.; Collier, J. L.; Karsch, S.

    2010-02-01

    Laser-plasma wakefield-based electron accelerators are expected to deliver ultrashort electron bunches with unprecedented peak currents. However, their actual pulse duration has never been directly measured in a single-shot experiment. We present measurements of the ultrashort duration of such electron bunches by means of THz time-domain interferometry. With data obtained using a 0.5 J, 45 fs, 800 nm laser and a ZnTe-based electro-optical setup, we demonstrate the duration of laser-accelerated, quasimonoenergetic electron bunches [best fit of 32 fs (FWHM) with a 90% upper confidence level of 38 fs] to be shorter than the drive laser pulse, but similar to the plasma period.

  7. Measurements of nonlinear refraction in the mid-infrared materials ZnGeP2 and AgGaS2

    NASA Astrophysics Data System (ADS)

    Li, Wenkai; Li, Yanyan; Xu, Yi; Lu, Jun; Wang, Pengfei; Du, Juan; Leng, Yuxin

    2017-03-01

    Accurate values of the nonlinear index of refraction n 2 for the nonlinear optical crystals ZnGeP2 and AgGaS2 were measured using the Z-scan technique. The results were obtained using 100-fs mid-infrared pulses from an OPA-DFG system driven by the 800-nm laser. The measured values of the AGS agree well with the theoretical values based on the two-band model for a direct band gap material. We confirmed the validity of the measured values for the indirect semiconductor ZGP by comparing the results with those obtained at 1300 nm in a previous study. We have proved the broadening due to GVD is negligible in our experiments. We believe these nonlinear measurements of AGS and ZGP are meaningful for the analysis and design of optical systems in the mid-infrared region.

  8. Measuring $\

    SciTech Connect

    Mitchell, Jessica Sarah

    2011-01-01

    The MINOS Experiment consists of two steel-scintillator calorimeters, sampling the long baseline NuMI muon neutrino beam. It was designed to make a precise measurement of the ‘atmospheric’ neutrino mixing parameters, Δm2 atm. and sin2 (2 atm.). The Near Detector measures the initial spectrum of the neutrino beam 1km from the production target, and the Far Detector, at a distance of 735 km, measures the impact of oscillations in the neutrino energy spectrum. Work performed to validate the quality of the data collected by the Near Detector is presented as part of this thesis. This thesis primarily details the results of a vμ disappearance analysis, and presents a new sophisticated fitting software framework, which employs a maximum likelihood method to extract the best fit oscillation parameters. The software is entirely decoupled from the extrapolation procedure between the detectors, and is capable of fitting multiple event samples (defined by the selections applied) in parallel, and any combination of energy dependent and independent sources of systematic error. Two techniques to improve the sensitivity of the oscillation measurement were also developed. The inclusion of information on the energy resolution of the neutrino events results in a significant improvement in the allowed region for the oscillation parameters. The degree to which sin2 (2θ )= 1.0 could be disfavoured with the exposure of the current dataset if the true mixing angle was non-maximal, was also investigated, with an improved neutrino energy reconstruction for very low energy events. The best fit oscillation parameters, obtained by the fitting software and incorporating resolution information were: | Δm2| = 2.32+0.12 -0.08×10-3 eV2 and sin2 (2θ ) > 0.90(90% C.L.). The analysis provides the current world best measurement of the atmospheric neutrino mass

  9. Photocurrent spectrum measurements of doped black silicon

    NASA Astrophysics Data System (ADS)

    Zhang, S. K.; Ahmar, H.; Chen, B.; Wang, W.; Alfano, R.

    2011-03-01

    Photocurrent spectra of doped black silicon (BSi) samples were investigated using metal-semiconductor-metal (MSM) structure. The BSi samples were fabricated through femtosecond-laser doping method. Two pieces of samples were annealed in nitrogen ambient for 30 minutes at different temperatures 350°C and 700°C. One control sample remains without annealing. It was found that the doped black silicon samples have an electron mobility as low as 40~50 cm2/V s but a conductivity as high as 4 ~ 5 Scm-1. The high conductivity allows making electrodes by directly contacting metal stripes onto the black silicon surfaces. For the sample without annealing, its photocurrent spectrum covers a wavelength range from 400 nm to 1200 nm. For the sample annealed at 350°C, no significant improvement was found except disappearance of a defect induced photocurrent peak at 660 nm. Further annealing at 700°C, as observed for the third sample, was found to greatly help enhance photoresponse in the wavelength range from 400 nm to 800 nm. The photocurrent spectra under different biases were also measured. With the increasing of bias from 0 to 0.6 V, the peak photoresponse was enhanced by about 5 times while large dark current brought in substantial noise level as well.

  10. The measured temperature and pressure of EDC37 detonation products

    NASA Astrophysics Data System (ADS)

    Ferguson, J. W.; Richley, J. C.; Sutton, B. D.; Price, E.; Ota, T. A.

    2017-01-01

    We present the experimentally determined temperature and pressure of the detonation products of EDC37; a HMX based conventional high explosive. These measurements were performed on a series of cylinder tests. The temperature measurements were undertaken at the end of the cylinder with optical fibres observing the bare explosive through a LiF window. The temperature of the products was measured for approximately 2 µs using single colour pyrometry, multicolour pyrometry and also using time integrated optical emission spectroscopy with the results from all three methods being broadly consistent. The peak temperature was found to be ≈ 3600 K dropping to ≈ 2400 K at the end of the measurement window. The spectroscopy was time integrated and showed that the emission spectra can be approximated using a grey body curve between 520 - 800 nm with no emission or absorption lines being observed. The pressure was obtained using an analytical method which requires the velocity of the expanding cylinder wall and the velocity of detonation. The pressure drops from an initial CJ value of ≈ 38 GPa to ≈ 4 GPa after 2 µs.

  11. Assessment of Vegetation Stress Using Reflectance or Fluorescence Measurements

    NASA Technical Reports Server (NTRS)

    Campbell, P. K. E.; Middleton, E. M.; McMurtrey, J. E.; Corp, L. A.; Chappelle, E. W.

    2007-01-01

    Current methods for large-scale vegetation monitoring rely on multispectral remote sensing, which has serious limitation for the detection of vegetation stress. To contribute to the establishment of a generalized spectral approach for vegetation stress detection, this study compares the ability of high-spectral resolution reflectance (R) and fluorescence (F) foliar measurements to detect vegetation changes associated with common environmental factors affecting plant growth and productivity. To obtain a spectral dataset from a broad range of species and stress conditions, plant material from three experiments was examined, including (i) corn, nitrogen (N) deficiency/excess; (ii) soybean, elevated carbon dioxide, and ozone levels; and (iii) red maple, augmented ultraviolet irradiation. Fluorescence and R spectra (400-800 nm) were measured on the same foliar samples in conjunction with photosynthetic pigments, carbon, and N content For separation of a wide range of treatment levels, hyperspectral (5-10 nm) R indices were superior compared with F or broadband R indices, with the derivative parameters optimal results. For the detection of changes in vegetation physiology, hyperspectral indices can provide a significant improvement over broadband indices. The relationship of treatment levels to R was linear, whereas that to F was curvilinear. Using reflectance measurements, it was not possible to identify the unstressed vegetation condition, which was accomplished in all three experiments using F indices. Large-scale monitoring of vegetation condition and the detection of vegetation stress could be improved by using hyperspectral R and F information, a possible strategy for future remote sensing missions.

  12. Assessment of Vegetation Stress Using Reflectance or Fluorescence Measurements

    NASA Technical Reports Server (NTRS)

    Campbell, P. K. E.; Middleton, E. M.; McMurtrey, J. E.; Corp, L. A.; Chappelle, E. W.

    2007-01-01

    Current methods for large-scale vegetation monitoring rely on multispectral remote sensing, which has serious limitation for the detection of vegetation stress. To contribute to the establishment of a generalized spectral approach for vegetation stress detection, this study compares the ability of high-spectral resolution reflectance (R) and fluorescence (F) foliar measurements to detect vegetation changes associated with common environmental factors affecting plant growth and productivity. To obtain a spectral dataset from a broad range of species and stress conditions, plant material from three experiments was examined, including (i) corn, nitrogen (N) deficiency/excess; (ii) soybean, elevated carbon dioxide, and ozone levels; and (iii) red maple, augmented ultraviolet irradiation. Fluorescence and R spectra (400-800 nm) were measured on the same foliar samples in conjunction with photosynthetic pigments, carbon, and N content For separation of a wide range of treatment levels, hyperspectral (5-10 nm) R indices were superior compared with F or broadband R indices, with the derivative parameters optimal results. For the detection of changes in vegetation physiology, hyperspectral indices can provide a significant improvement over broadband indices. The relationship of treatment levels to R was linear, whereas that to F was curvilinear. Using reflectance measurements, it was not possible to identify the unstressed vegetation condition, which was accomplished in all three experiments using F indices. Large-scale monitoring of vegetation condition and the detection of vegetation stress could be improved by using hyperspectral R and F information, a possible strategy for future remote sensing missions.

  13. Measurements of the optical properties of tissue in conjunction with photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Nilsson, Annika M. K.; Berg, Roger; Andersson-Engels, Stefan

    1995-07-01

    A simple optical dosimeter was used to measure the light intensity in rat liver and muscle in vivo with fibers positioned at different depths to investigate whether the light penetration changed during photodynamic therapy (PDT). The results were then correlated with measurements of the three optical-interaction coefficients mu s, mu a, and g for wavelengths in the range 500-800 nm for PDT-treated and nontreated rat liver and muscle tissue in vitro. A distinct increase in the absorption coefficient was seen immediately after treatment, in agreement with the decreasing light intensity observed during the treatment, as measured with the optical dosimeter. The collimated transmittance was measured with a narrow-beam setup, and an optical integrating sphere was used to measure the diffuse reflectance and total transmittance of the samples. The corresponding optical properties were obtained by spline interpolation of Monte Carlo-simulated data. To ensure that the measured values were correct, we performed calibration measurements with suspensions of polystyrene microspheres and ink.

  14. Absolute fluorescence measurements > 1000 nm: setup design, calibration and standards (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Resch-Genger, Ute; Würth, Christian; Pauli, Jutta; Hatami, Soheil; Kaiser, Martin

    2016-03-01

    There is an increasing interest in optical reporters like semiconductor quantum dots and upconversion nanophosphors with emission < 1000 nm for bioanalysis, medical diagnostics, and safety barcodes and hence, in reliable fluorescence measurements in this wavelength region, e.g., for the comparison of material performance and the rational design of new nanomaterials with improved properties [1-4]. The performance of fluorescence measurements < 800 nm and especially < 1000 nm is currently hampered by the lack of suitable methods and standards for the simple determination of the wavelength-dependent spectral responsivity of fluorescence measuring systems and the control of measured emission spectra and intensities [3-5]. This is of special relevance for nanocrystalline emitters like quantum dots and rods as well as for upconversion nanocrystals, where surface states and the accessibility of emissive states by quenchers largely control accomplishable quantum yields and hence, signal sizes and detection sensitivities from the reporter side. Here, we present the design of an integrating sphere setup for the absolute measurement of emission spectra and quantum yields in the wavelength region of 650 to 1600 nm and its calibration as well as examples for potential fluorescence standards from different reporter classes for the control of the reliability of such measurements [5]. This includes new spectral fluorescence standards for the wavelength region of 650 nm to 1000 nm as well as a set of quantum yield standards covering the wavelength region from 400 nm to 1000 nm.

  15. In situ measurements and analysis of apparent optical properties in the Red Sea

    NASA Astrophysics Data System (ADS)

    Tiwari, Surya Prakash; Jones, Burton

    2015-04-01

    Much of the Red Sea is considered as a typical oligotrophic sea. Its optical properties are investigated utilizing the data collected several cruises during 2014. Apparent Optical Property (AOP) profiles were obtained with a Satlantic HyperPro instrument is deployed in free-fall profiler mode to measure upwelling radiance and downwelling irradiance in the spectral range of 350 to 800 nm with simultaneous measurements of conductivity, temperature, depth, salinity, chlorophyll fluorescence, and optical backscattering coefficient in red band. These measurements will be used to describe apparent optical properties in the Red Sea, which is not yet studied. Spectral remote sensing reflectance (Rrs) and diffuse attenuation coefficient (Kd) is derived from our measurements. The Rrs determines how the light is backscattered of the water that can be detected by satellite ocean color sensor and Kd determines an intensity of light penetration into the water column. Thus, the results obtained from these analyses will be exploited to develop specific light models for the Red Sea.

  16. ULTRAFAST MEASUREMENT OF THE OPTICAL PROPERTIES OF SHOCKED NICKEL AND LASER HEATED GOLD

    SciTech Connect

    Funk, D. J.; Reho, J. H.; Moore, David S.; Gahagan, K. A.; Rabie, R. L.; McGrane, S.

    2001-01-01

    We have used high-resolution Frequency Domain Interferometry (FDI) to make the first ultrafast measurement of shock-induced changes in the optical properties of thin nickel ({approx}500 nm) targets. Data taken at several angles of incidence allowed the separation of optical effects from material motion, yielding an effective complex index for the shocked material. In contrast to our previous studies of aluminum, measurements with an 800 nm probe wavelength found a phase shift attributable to optical property changes with the same sign as that due to surface motion, during an 11.5 GPa shock breakout. A similar experiment was attempted with thin gold films ({approx}180 nm) using Ultrafast Spatial Interferometry (USI). However, since the electron-phonon coupling in gold is extremely weak, a shock is observed as it 'forms'. Ballistic electrons and electron-electron equilibrium cause fast heating of the electrons in the entire thickness of the thin film, followed by lattice excitation through electron-phonon coupling, eventually leading to melt and frustrated thermal expansion yielding the observed surface motion. We suggest that these experiments offer a new path for observation of phase changes or for temperature measurements, by allowing a determination of the complex index under dynamic loading conditions and comparing the measured values to those obtained under static conditions.

  17. Study on the water content measurement of tomatoes by near infrared technique

    NASA Astrophysics Data System (ADS)

    Jiang, Huanyu; Ying, Yibin; Bao, Yingshi

    2005-11-01

    Near infrared (NIR) spectroscopy is a promising technique for nondestructive measurement of farm products quality measurement and information acquisition. The objective of this research was to study the potential of NIR diffuse reflectance spectroscopy as a way for nondestructive measurement of the water content of tomato leaves. A total of 120 leaves were collected as experimental materials, 80 of them were used to form a calibration data set. In order to set up a calibration model, NIR spectral data were collected in the spectral region between 800 nm and 2500 nm by NIR spectrometer of Nicolet Corporation, and water content of tomato leaves by a drying chest, four different mathematical treatments were used in spectrums processing: different wavelength range, baseline correction, smoothing, first and second derivative. Depending on data preprocessing and PLS analysis, we can get best prediction model when we select original spectra by baseline correction at full wavelength range (800-2500nm), the best model of water content has a root mean square error of prediction (RMSEP) of 1.91, a root mean square error of calibration (RMSEC) of 0.731 and a calibration correlation coefficient (R) value of 0.96265. It is conclude that the FTNIR method with Smart Near-IR UpDRIFT accessory can accurate estimate the water content in tomato leaves.

  18. Removal of surface-reflected light for the measurement of remote-sensing reflectance from an above-surface platform.

    PubMed

    Lee, Zhongping; Ahn, Yu-Hwan; Mobley, Curtis; Arnone, Robert

    2010-12-06

    Using hyperspectral measurements made in the field, we show that the effective sea-surface reflectance ρ (defined as the ratio of the surface-reflected radiance at the specular direction corresponding to the downwelling sky radiance from one direction) varies not only for different measurement scans, but also can differ by a factor of 8 between 400 nm and 800 nm for the same scan. This means that the derived water-leaving radiance (or remote-sensing reflectance) can be highly inaccurate if a spectrally constant ρ value is applied (although errors can be reduced by carefully filtering measured raw data). To remove surface-reflected light in field measurements of remote sensing reflectance, a spectral optimization approach was applied, with results compared with those from remote-sensing models and from direct measurements. The agreement from different determinations suggests that reasonable results for remote sensing reflectance of clear blue water to turbid brown water are obtainable from above-surface measurements, even under conditions of high waves.

  19. Evaluation of the vacuum-assisted handpiece compared with the sapphire-cooled handpiece of the 800-nm diode laser system for the use of hair removal and reduction.

    PubMed

    Xia, Yang; Moore, Rachael; Cho, Sunghun; Ross, Edward V

    2010-12-01

    A handpiece with a 35 × 22-mm treatment window that uses vacuum technology has been designed for the diode laser system. Vacuum suction stretches the skin and brings the hair follicle closer to the surface with the intent to damage the hair follicle at a lower surface fluence. The objective of this study was to compare the degree of follicular thermal damage between the sapphire-cooled smaller handpiece at a higher fluence versus the larger vacuum-assisted handpiece at a lower fluence. Five male patients with Fitzpatrick skin types I-IV were enrolled in the study. Three test spots on the right back were treated with the vacuum-assisted laser handpiece at a setting of 10-12 J/cm², and 61-ms pulse duration. Three test spots on the left back were treated with the sapphire-cooled handpiece with a setting of 30-34 J/cm² and a pulse duration of 14-16 ms. A punch biopsy was obtained from one treated area for each handpiece type. The biopsies were sectioned horizontally and examined for the degree of thermal damage to the hair follicle at the level of the isthmus and the bulb. Immediate treatment response, pain score, and total treatment time were recorded. Biopsies from the skin treated with the sapphire-cooled handpiece and the vacuum-assisted handpiece showed the mean hair follicle diameter was 258.3 µm (SE [standard error] 41.7) and 225.1 µm (SE 17.1), respectively. The mean thermal damage diameter to hair diameter ratio was 0.91 (SE 0.10) and 0.72 (SE 0.12), respectively. The mean immediate treatment response, the mean pain severity, and the mean total treatment time were all lower for the vacuum-assisted handpiece. Treatment with the vacuum-assisted handpiece is faster and has a tendency to be more comfortable. Thermal damage to the hair follicle was greater with the sapphire-cooled handpiece.

  20. Measurement of Scattering and Absorption Cross Sections of Dyed Microspheres

    PubMed Central

    Gaigalas, Adolfas K; Choquette, Steven; Zhang, Yu-Zhong

    2013-01-01

    nm to 800 nm. PMID:26401422

  1. An automated research facility for measuring thermoluminescence emission spectra using an optical multichannel analyzer

    NASA Astrophysics Data System (ADS)

    Piters, T. M.; Meulemans, W. H.; Bos, A. J. J.

    1993-01-01

    A facility for research into the mechanism of thermoluminescence (TL) is described. The facility comprises three units: an annealing oven, an irradiator, and a TL-emission spectrometer. Crystals or hot-pressed chips can be moved from and to the mentioned units by an automated sample changer. All units operate automatically and are controlled by a personal computer program. The spectrometer is based on a dispersive grating and an intensified diode array (512 active elements) and covers the 200-800-nm wavelength range. The wavelength resolution of the spectrometer is 6 nm when a 25-μm-wide entrance slit is used and 29 nm when a 1-mm-wide entrance slit is used. The sensitive spectrometer could measure emission spectra of CaSO4:Dy (TLD-200) irradiated at an absorbed dose as low as 3 mGy at a signal-to-noise ratio of 10:1 for LiF:Mg,Ti (TLD-100) this ratio was obtained at 75 mGy. A detailed description is given how measured data can be related to spectra predicted by a model, taking into account all system aberrations. Spectra of LiF:Mg,Ti (TLD-100) irradiated to an absorbed dose of 5 Gy are analyzed according to the Franck-Condon model for light emission. Two emission bands with peak energies of 3.01 and 2.60 eV at 463 K have been found.

  2. Diffuse reflectance spectroscopy as a tool to measure the absorption coefficient in skin: system calibration.

    PubMed

    Karsten, A E; Singh, A; Karsten, P A; Braun, M W H

    2013-02-01

    An individualised laser skin treatment may enhance the treatment and reduces risks and side-effects. The optical properties (absorption and scattering coefficients) are important parameters in the propagation of laser light in skin tissue. The differences in the melanin content of different skin phototypes influence the absorption of the light. The absorption coefficient at the treatment wavelength for an individual can be determined by diffuse reflectance spectroscopy, using a probe containing seven fibres. Six of the fibres deliver the light to the measurement site and the central fibre collects the diffused reflected light. This is an in vivo technique, offering benefits for near-real-time results. Such a probe, with an effective wavelength band from 450 to 800 nm, was used to calibrate skin-simulating phantoms consisting of intralipid and ink. The calibration constants were used to calculate the absorption coefficients from the diffuse reflectance measurements of three volunteers (skin phototypes, II, IV and V) for sun-exposed and non-exposed areas on the arm.

  3. Platinum plasmonic nanostructure arrays for massively parallel single-molecule detection based on enhanced fluorescence measurements.

    PubMed

    Saito, Toshiro; Takahashi, Satoshi; Obara, Takayuki; Itabashi, Naoshi; Imai, Kazumichi

    2011-11-04

    We fabricated platinum bowtie nanostructure arrays producing fluorescence enhancement and evaluated their performance using two-photon photoluminescence and single-molecule fluorescence measurements. A comprehensive selection of suitable materials was explored by electromagnetic simulation and Pt was chosen as the plasmonic material for visible light excitation near 500 nm, which is preferable for multicolor dye-labeling applications like DNA sequencing. The observation of bright photoluminescence (λ = 500-600 nm) from each Pt nanostructure, induced by irradiation at 800 nm with a femtosecond laser pulse, clearly indicates that a highly enhanced local field is created near the Pt nanostructure. The attachment of a single dye molecule was attempted between the Pt triangles of each nanostructure by using selective immobilization chemistry. The fluorescence intensities of the single dye molecule localized on the nanostructures were measured. A highly enhanced fluorescence, which was increased by a factor of 30, was observed. The two-photon photoluminescence intensity and fluorescence intensity showed qualitatively consistent gap size dependence. However, the average fluorescence enhancement factor was rather repressed even in the nanostructure with the smallest gap size compared to the large growth of photoluminescence. The variation of the position of the dye molecule attached to the nanostructure may influence the wide distribution of the fluorescence enhancement factor and cause the rather small average value of the fluorescence enhancement factor.

  4. Noninvasive method for measuring local hemoglobin oxygen saturation in tissue using wide gap second derivative near-infrared spectroscopy.

    PubMed

    Myers, Dean E; Anderson, LeAnn D; Seifert, Roxanne P; Ortner, Joseph P; Cooper, Chris E; Beilman, Greg J; Mowlem, John D

    2005-01-01

    A simple continuous wave near-infrared algorithm for estimating local hemoglobin oxygen saturation in tissue (%StO2) is described using single depth attenuation measurements at 680, 720, 760, and 800 nm. Second derivative spectroscopy was used to reduce light scattering effects, chromophores with constant absorption, baseline/instrumentation drift, and movement artifacts. Unlike previous second derivative methods which focused primarily on measuring deoxyhemoglobin concentration; a wide 40 nm wavelength gap used for calculating second derivative attenuation significantly improved sensitivity to oxyhemoglobin absorption. Scaled second derivative attenuation at 720 nm was correlated to in vitro hemoglobin oxygen saturation to generate a %StO2 calibration curve. The calibration curve was insensitive to total hemoglobin, optical path length, and optical scattering. Measurement error due to normal levels of carboxyhemoglobin, methemoglobin, and water absorption were less than 10 %StO2 units. Severe methemoglobinemia or edema combined with low blood volume could cause StO2 errors to exceed 10 StO2 units. Both a broadband and commercial four-wavelength spectrometer (InSpectra) measured %StO2. The InSpectra tissue spectrometer readily detected limb ischemia on 26 human volunteers for hand, forearm, and leg muscles. A strong linear correlation, r2>0.93, between StO2 and microvascular %SO2 was observed for isolated animal hind limb, kidney, and heart.

  5. Z-scan measurement of the nonlinear refractive index of monolayer WS(2).

    PubMed

    Zheng, Xin; Zhang, Yangwei; Chen, Runze; Cheng, Xiang'ai; Xu, Zhongjie; Jiang, Tian

    2015-06-15

    Transition metal dichalcogenides (TMDCs), such as tungsten disulfide (WS(2)), are layered materials with strong in-plane bonding and weak out-of-plane interactions enabling exfoliation into two-dimensional layers of single unit cell thickness. Recent advances in nanoscale materials characterization and few layer TMDCs' unique optical properties make them a research hot-spot in nonlinear optics. In this work, the nonlinear refractive index of monolayer WS(2) has been characterized with Z-scan measurement under 800nm femtosecond pulsed laser excitation, and a value of n2 ≃ (8.1 ± 0.41) × 10(-13)m(2)/W is obtained. A shift from saturable absorption to reverse saturable absorption was observed at higher input pump intensities in the experiments. The transition process was analyzed using a phenomenological model based on two photon absorption, and the two photon absorption coefficient was estimated about (3.7±0.28)×10(-6)m/W.

  6. Ultrafast optical measurements of surface waves on a patterned layered nanostructure

    NASA Astrophysics Data System (ADS)

    Daly, Brian; Bjornsson, Matteo; Connolly, Aine; Mahat, Sushant; Rachmilowitz, Bryan; Antonelli, George; Myers, Alan; Yoo, Hui-Jae; Singh, Kanwal; King, Sean

    2015-03-01

    We report ultrafast optical pump-probe measurements of 12 - 54 GHz surface acoustic waves (SAWs) on patterned layered nanostructures. These very high frequency SAWs were generated and detected on the following patterned film stack: 25 nm physically vapor deposited TiN / 180 nm porous PECVD-grown a-SiOC:H dielectric / 12 nm non-porous PECVD-grown a-SiOC:H etch-stop / 100 nm CVD-grown a-SiO2 / Si (100) substrate. The TiN layer was dry plasma etched to form lines of rectangular cross section with pitches of 420 nm, 250 nm, 180 nm, and 168 nm and the lines were oriented parallel to the [110] direction on the wafer surface. The absorption of ultrafast pulses from a Ti:sapphire oscillator operating at 800 nm generated SAWs that were detected by time-delayed probe pulses from the same oscillator via a reflectivity change (ΔR) . In each of the four cases the SAW frequency increased with decreasing pitch, but not in a linear way as had been seen in previous experiments of this sort. By comparing the results with mechanical simulations, we present evidence for the detection of different types of SAWs in each case, including Rayleigh-like waves, Sezawa waves, and leaky or radiative waves. This work was supported by NSF Award DMR1206681.

  7. Comparison of spatially and temporally resolved diffuse-reflectance measurement systems for determination of biomedical optical properties.

    PubMed

    Swartling, Johannes; Dam, Jan S; Andersson-Engels, Stefan

    2003-08-01

    Time-resolved and spatially resolved measurements of the diffuse reflectance from biological tissue are two well-established techniques for extracting the reduced scattering and absorption coefficients. We have performed a comparison study of the performance of a spatially resolved and a time-resolved instrument at wavelengths 660 and 786 nm and also of an integrating-sphere setup at 550-800 nm. The first system records the diffuse reflectance from a diode laser by means of a fiber bundle probe in contact with the sample. The time-resolved system utilizes picosecond laser pulses and a single-photon-counting detection scheme. We extracted the optical properties by calibration using known standards for the spatially resolved system, by fitting to the diffusion equation for the time-resolved system, and by using an inverse Monte Carlo model for the integrating sphere. The measurements were performed on a set of solid epoxy tissue phantoms. The results showed less than 10% difference in the evaluation of the reduced scattering coefficient among the systems for the phantoms in the range 9-20 cm(-1), and absolute differences of less than 0.05 cm(-1) for the absorption coefficient in the interval 0.05-0.30 cm(-1).

  8. Instrumentation and calibration methods for the multichannel measurement of phase and amplitude in optical tomography

    SciTech Connect

    Nissilae, Ilkka; Noponen, Tommi; Kotilahti, Kalle; Katila, Toivo; Lipiaeinen, Lauri; Tarvainen, Tanja; Schweiger, Martin; Arridge, Simon

    2005-04-01

    In this article, we describe the multichannel implementation of an intensity modulated optical tomography system developed at Helsinki University of Technology. The system has two time-multiplexed wavelengths, 16 time-multiplexed source fibers and 16 parallel detection channels. The gain of the photomultiplier tubes (PMTs) is individually adjusted during the measurement sequence to increase the dynamic range of the system by 10{sup 4}. The PMT used has a high quantum efficiency in the near infrared (8% at 800 nm), a fast settling time, and low hysteresis. The gain of the PMT is set so that the dc anode current is below 80 nA, which allows the measurement of phase independently of the intensity. The system allows measurements of amplitude at detected intensities down to 1 fW, which is sufficient for transmittance measurements of the female breast, the forearm, and the brain of early pre-term infants. The mean repeatability of phase and the logarithm of amplitude (ln A) at 100 MHz were found to be 0.08 deg. and 0.004, respectively, in a measurement of a 7 cm phantom with an imaging time of 5 s per source and source optical power of 8 mW. We describe a three-step method of calibrating the phase and amplitude measurements so that the absolute absorption and scatter in tissue may be measured. A phantom with two small cylindrical targets and a second phantom with three rods are measured and reconstructions made from the calibrated data are shown and compared with reconstructions from simulated data.

  9. Instrumentation and calibration methods for the multichannel measurement of phase and amplitude in optical tomography

    NASA Astrophysics Data System (ADS)

    Nissilä, Ilkka; Noponen, Tommi; Kotilahti, Kalle; Katila, Toivo; Lipiäinen, Lauri; Tarvainen, Tanja; Schweiger, Martin; Arridge, Simon

    2005-04-01

    In this article, we describe the multichannel implementation of an intensity modulated optical tomography system developed at Helsinki University of Technology. The system has two time-multiplexed wavelengths, 16 time-multiplexed source fibers and 16 parallel detection channels. The gain of the photomultiplier tubes (PMTs) is individually adjusted during the measurement sequence to increase the dynamic range of the system by 104. The PMT used has a high quantum efficiency in the near infrared (8% at 800nm), a fast settling time, and low hysteresis. The gain of the PMT is set so that the dc anode current is below 80nA, which allows the measurement of phase independently of the intensity. The system allows measurements of amplitude at detected intensities down to 1fW, which is sufficient for transmittance measurements of the female breast, the forearm, and the brain of early pre-term infants. The mean repeatability of phase and the logarithm of amplitude (lnA) at 100MHz were found to be 0.08° and 0.004, respectively, in a measurement of a 7cm phantom with an imaging time of 5s per source and source optical power of 8mW. We describe a three-step method of calibrating the phase and amplitude measurements so that the absolute absorption and scatter in tissue may be measured. A phantom with two small cylindrical targets and a second phantom with three rods are measured and reconstructions made from the calibrated data are shown and compared with reconstructions from simulated data.

  10. Validity Assessment of Pixel Linear Spectral Mixing Through Laboratory Measurements

    NASA Astrophysics Data System (ADS)

    Mobasheri, M. R.; Dehnavi, S.; Maghsoudi, Y.

    2015-12-01

    In order to understand the characteristics of the data collected by hyperspectral imaging systems, it is important to discuss the physics behind the scene radiance field incident on the imaging system. A dominant effect in hyperspectral remote sensing is the mixing of radiant energies contributed from different materials present in a given pixel. The basic assumption of mixture modelling is that within a given scene, the surface is covered by a small number of distinct materials that have relatively constant spectral properties. It is most common to assume that the radiance reflected by different materials in a pixel can spectrally combine in a linear additive manner to produce the pixel radiance/reflectance, even when that might not be the case e.g. where the mixing process leads to nonlinear combinations of the radiance and where the linear assumption fails to hold. This can occur where there is significant relative three-dimensional structure within a given pixel. Without detailed knowledge of the dimensional structure, it can be very difficult to correctly ``un-mix'' the contributions of the various materials. This work aims to evaluate the correctness of the linear assumption in the mixture modelling using some laboratory measurements. Study was conducted using some sheets made of cellulose materials of different colours in 400-800 nm spectral range. Experimental results have shown that a correction term must be applied to the gains and offsets in the linear model. The obtained results can be extended to satellite sensors that acquire images in the above mentioned spectral range.

  11. Absolute quantum yield measurement of powder samples.

    PubMed

    Moreno, Luis A

    2012-05-12

    quantum yield calculation. 5. Corrected quantum yield calculation. 6. Chromaticity coordinates calculation using Report Generator program. The Hitachi F-7000 Quantum Yield Measurement System offer advantages for this application, as follows: High sensitivity (S/N ratio 800 or better RMS). Signal is the Raman band of water measured under the following conditions: Ex wavelength 350 nm, band pass Ex and Em 5 nm, response 2 sec), noise is measured at the maximum of the Raman peak. High sensitivity allows measurement of samples even with low quantum yield. Using this system we have measured quantum yields as low as 0.1 for a sample of salicylic acid and as high as 0.8 for a sample of magnesium tungstate. Highly accurate measurement with a dynamic range of 6 orders of magnitude allows for measurements of both sharp scattering peaks with high intensity, as well as broad fluorescence peaks of low intensity under the same conditions. High measuring throughput and reduced light exposure to the sample, due to a high scanning speed of up to 60,000 nm/minute and automatic shutter function. Measurement of quantum yield over a wide wavelength range from 240 to 800 nm. Accurate quantum yield measurements are the result of collecting instrument spectral response and integrating sphere correction factors before measuring the sample. Large selection of calculated parameters provided by dedicated and easy to use software. During this video we will measure sodium salicylate in powder form which is known to have a quantum yield value of 0.4 to 0.5.

  12. Light transmission of the ocular media in birds and mammals.

    PubMed

    Tsukahara, Naoki; Tani, Yuri; Kikuchi, Hideyuki; Sugita, Shoei

    2014-01-01

    Differences in the ultraviolet (UV) cutoff of ocular media between birds and mammals have been revealed by spectrophotometric measurements of the transmission of light wavelengths by the cornea, lens and vitreous body in chickens, crows, quails, rats, rabbits and pigs. The light transmission values of the cornea were shown to be above 50% for wavelengths of 330-800 nm in birds, 300-800 nm in rat and 310-800 nm in mammals except for rat. For the lens, the light transmission values were shown to be above 50% for wavelengths of 320-800 nm in birds and rat and 390-800 nm in mammals except for rat. Thus, among the ocular media, the cornea in birds and the lens in mammals except for rat may play a role as a major UV cutoff filter.

  13. Dual-wavelength photothermal optical coherence tomography for blood oxygen saturation measurement

    NASA Astrophysics Data System (ADS)

    Yin, Biwei; Kuranov, Roman V.; McElroy, Austin B.; Milner, Thomas E.

    2013-03-01

    We report design and demonstration of a dual wavelength photothermal (DWP) optical coherence tomography (OCT) system for imaging of a phantom microvessel and measurement of hemoglobin oxygen saturation (SO2) level. The DWP-OCT system contains a swept-source (SS) two-beam phase-sensitive (PhS) OCT system (1060 nm) and two intensity modulated photothermal excitation lasers (770 nm and 800 nm). The PhS-OCT probe beam (1060 nm) and photothermal excitation beams are combined into one single-mode optical fiber. A galvanometer based two-dimensional achromatic scanning system is designed to provide 14 μm lateral resolution for the PhS-OCT probe beam (1060 nm) and 13 μm lateral resolution for photothermal excitation beams. DWP-OCT system's sensitivity is 102 dB, axial resolution is 13 μm in tissue and uses a real-time digital dispersion compensation algorithm. Noise floor for optical pathlength measurements is 300 pm in the signal frequency range (380-400 Hz) of photothermal modulation frequencies. Blood SO2 level is calculated from measured optical pathlength (op) signal in a 300 μm diameter microvessel phantom introduced by the two photothermal excitation beams. En-face and B-scan images of a phantom microvessel are recorded, and six blood samples' SO2 levels are measured using DWP-OCT and compared with values provided by a commercial blood oximeter. A mathematical model indicates thermal diffusion introduces a systematic artifact that over-estimates SO2 values and is consistent with measured data.

  14. Optical pH measurements with water dispersion of polyaniline nanoparticles and their redox sensitivity.

    PubMed

    Lindfors, Tom; Harju, Leo; Ivaska, Ari

    2006-05-01

    A new method for optical pH and redox measurements with a commercially available water dispersion of polyaniline (PANI) nanoparticles (mean particle size, 46 nm) is presented. The pH measurements are based on the acid-base equilibrium of PANI and were carried out either by combining both the automated sequential injection analysis (SIA) and UV-visible spectrophotometric techniques or with a fiber-optic light guide. In the former case, the detection was done in continuous mode at lambda = 800 nm by using the SIA technique for transporting the sample to a flow-through cell, which was placed in the light path of the photometer. With the fiber-optic light guide, the detection was done in batch mode at lambda = 400 and 580 nm. In both methods, fresh pH reagent (PANI) solution was used in each measurement, thus overcoming the problem with hysteresis (memory effect), which is usually observed with PANI films. The PANI nanoparticles were characterized with UV-visible spectroscopy in pH buffer solutions between pH 2-12 and a protonation constant of logK(0.5H,L)(H(0.5)L) = 4.4 was calculated from these data. Fast pH measurements can be done between pH 6 and 10.5 depending on the measuring technique. It is possible to determine pH with an accuracy of 0.1 pH unit between pH 8 and 10.5 (RSD, 0.5-2%). Redox transitions typical for PANI films were also observed for water solutions of PANI nanoparticles in the presence of the hexacyanoferrate(II/III) and the iron(II/III) oxalate redox couples. The absorbance at lambda = 875 nm is linearly dependent on the logarithm of the concentration ratio (0.1-10) of the iron oxalate redox couple.

  15. Measuring the coral reef distribution of Kuroshima Island by satellite remote sensing

    SciTech Connect

    Miyazaki, Tadakuni; Harashima, Akira; Nakatani, Yukihiro

    1995-12-31

    Coral reefs are the major sites for photo-synthesis and calcification in the present ocean. Estimating the production rate of calcification by the coral reefs or investigating the sink/source mechanism of CO{sub 2} by the coral reefs in the ocean, the distribution of the coral reefs in the world wide must be identified. Measuring the spectral signatures of underwater coral reefs and mapping of coral reefs by satellite remote sensing are described. The spectral signatures of different species of the coral reefs were measured using a spectroradiometer at off Kuroshima Island, Okinawa, Japan and investigated spectral difference between different species of the coral reefs. As well as the field experiments, laboratory experiments for measuring the spectral signatures of 9 different species of coral reefs were carried out with the same spectroradiometer. The spectral reflectance of each coral reef showed a significant result that a narrow absorption band exists in the spectral region between 660 and 680 nm, and very strong spectral reflectance from about 700 nm towards the longer wavelength range. On the other hand, absorption and the high reflectance region were not observed from the bottom sands or bare rocks underwater. These experiments suggested that there is a significant spectral difference between coral reefs and bottom sands or bare rocks and so the best spectral range for separating the coral reefs from other underwater objects in the ocean would be between 700 and 800 nm. As well as the basic spectral measurement either in the field or at the laboratory, SPOT satellite imageries were used to classify the underwater coral reefs. Classification methods used here were the principal component analysis, and the maximum likelihood. Finally, the evaluation of classification method for extracting the coral reefs was introduced.

  16. Development of a 3D-AFM for true 3D measurements of nanostructures

    NASA Astrophysics Data System (ADS)

    Dai, Gaoliang; Häßler-Grohne, Wolfgang; Hüser, Dorothee; Wolff, Helmut; Danzebrink, Hans-Ulrich; Koenders, Ludger; Bosse, Harald

    2011-09-01

    The development of advanced lithography requires highly accurate 3D metrology methods for small line structures of both wafers and photomasks. Development of a new 3D atomic force microscopy (3D-AFM) with vertical and torsional oscillation modes is introduced in this paper. In its configuration, the AFM probe is oscillated using two piezo actuators driven at vertical and torsional resonance frequencies of the cantilever. In such a way, the AFM tip can probe the surface with a vertical and a lateral oscillation, offering high 3D probing sensitivity. In addition, a so-called vector approach probing (VAP) method has been applied. The sample is measured point-by-point using this method. At each probing point, the tip is approached towards the surface until the desired tip-sample interaction is detected and then immediately withdrawn from the surface. Compared to conventional AFMs, where the tip is kept continuously in interaction with the surface, the tip-sample interaction time using the VAP method is greatly reduced and consequently the tip wear is reduced. Preliminary experimental results show promising performance of the developed system. A measurement of a line structure of 800 nm height employing a super sharp AFM tip could be performed with a repeatability of its 3D profiles of better than 1 nm (p-v). A line structure of a Physikalisch-Technische Bundesanstalt photomask with a nominal width of 300 nm has been measured using a flared tip AFM probe. The repeatability of the middle CD values reaches 0.28 nm (1σ). A long-term stability investigation shows that the 3D-AFM has a high stability of better than 1 nm within 197 measurements taken over 30 h, which also confirms the very low tip wear.

  17. Simultaneous time-space resolved reflectivity and interferometric measurements of dielectrics excited with femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Garcia-Lechuga, M.; Haahr-Lillevang, L.; Siegel, J.; Balling, P.; Guizard, S.; Solis, J.

    2017-06-01

    Simultaneous time-and-space resolved reflectivity and interferometric measurements over a temporal span of 300 ps have been performed in fused silica and sapphire samples excited with 800 nm, 120 fs laser pulses at energies slightly and well above the ablation threshold. The experimental results have been simulated in the frame of a multiple-rate equation model including light propagation. The comparison of the temporal evolution of the reflectivity and the interferometric measurements at 400 nm clearly shows that the two techniques interrogate different material volumes during the course of the process. While the former is sensitive to the evolution of the plasma density in a very thin ablating layer at the surface, the second yields an averaged plasma density over a larger volume. It is shown that self-trapped excitons do not appreciably contribute to carrier relaxation in fused silica at fluences above the ablation threshold, most likely due to Coulomb screening effects at large excited carrier densities. For both materials, at fluences well above the ablation threshold, the maximum measured plasma reflectivity shows a saturation behavior consistent with a scattering rate proportional to the plasma density in this fluence regime. Moreover, for both materials and for pulse energies above the ablation threshold and delays in the few tens of picoseconds range, a simultaneous "low reflectivity" and "low transmission" behavior is observed. Although this behavior has been identified in the past as a signature of femtosecond laser-induced ablation, its origin is alternatively discussed in terms of the optical properties of a material undergoing strong isochoric heating, before having time to substantially expand or exchange energy with the surrounding media.

  18. Excitation-emission matrices measurements of human cutaneous lesions: tool for fluorescence origin

    NASA Astrophysics Data System (ADS)

    Zhelyazkova, A.; Borisova, E.; Angelova, L.; Pavlova, E.; Keremedchiev, M.

    2013-11-01

    The light induced fluorescence (LIF) technique has the potential of providing real-time diagnosis of malignant and premalignant skin tissue; however, human skin is a multilayered and inhomogeneous organ with different optical properties that complicate the analysis of cutaneous fluorescence spectra. In spite of the difficulties related to the detection and analysis of fluorescent data from skin lesions, this technique is among the most widely applied techniques in laboratorial and pre-clinical investigations for early skin neoplasia diagnosis. The important point is to evaluate all sources of intrinsic fluorescence and find any significant alterations distinguishing the normal skin from a cancerous state of the tissue; this would make the autofluorescence signal obtained useful for the development of a non-invasive diagnostic tool for the dermatological practice. Our investigations presented here were based on ex vivo point-by-point measurements of excitation-emission matrices (EEM) from excised tumor lesions and the surrounding skin taken during the daily clinical practice of Queen Jiovanna- ISUL University Hospital, Sofia, the local Ethical Committee's approval having already been obtained. The fluorescence emission was measured between 300 nm and 800 nm using excitation in the 280-440 nm spectral range. In the process of excitation-emission matrices (EEM) measurements we could establish the origin of the autofluorescence and the compounds related by assigning the excitation and emission maxima obtained during the experiments. The EEM were compared for normal human skin, basal cell carcinoma, squamous cell carcinoma, benign nevi and malignant melanoma lesions to obtain information for the most common skin malignancies and their precursors. The main spectral features and the applicability of the technique of autofluorescent spectroscopy of human skin in general as an initial diagnostic tool are discussed as well.

  19. PM2.5 soluble brown-carbon measured in contrasting urban and rural environments

    NASA Astrophysics Data System (ADS)

    Weber, R.; Zhang, X.

    2011-12-01

    An instrument was developed to continuously measure the light absorption spectra and carbon mass of soluble PM2.5 components by coupling a particle-into-liquid sampler (PILS), UV-VIS (200-800nm) spectrophotometer with long-path absorption cell and total organic carbon (TOC) analyzer. The analytical system has also been used to measure brown carbon in aqueous extracts from integrated filters. Measurements have been conducted at a number of locations, including urban sites in Los Angeles, Atlanta and smaller urban and rural locations in the southeastern US. At all locations a characteristic brown carbon absorption spectra was observed, where soluble chromophores produce an increasing absorption with decreasing wavelength, starting from mid-visible and extending into the near UV. Incomplete combustion from biomass and fossil fuel burning and secondary processes have been identified as sources of soluble brown carbon. During summer when biomass burning impacts were minimal, mass absorption efficiencies calculated relative to ambient particle water-soluble organic carbon (WSOC) were highest in Los Angeles and correlated with the daily production of secondary organic aerosol. Nitro-aromatics were identified as a component of the brown carbon. In contrast, the Atlanta secondary aerosol was significantly less light-absorbing, and unlike Los Angeles the diurnal trend in brown carbon largely tracked primary sources. Absorption Angstrom exponents varied between 3 and 7 with fresh Los Angeles secondary organic aerosol associated with smaller exponents, indicting greater absorption into the visible spectrum. The southeastern US regional/rural brown carbon was the least absorbing per WSOC mass in the UV and with largest Angstrom exponents (7) the least absorbing at higher wavelengths. A correlation between the regional brown carbon and fine particle oxalate suggested an aqueous phase heterogeneous source for these chromophores. Compared to pure black carbon, brown carbon was

  20. Measurement of degenerate two-photon absorption spectra of a series of developed two-photon initiators using a dispersive white light continuum Z-scan

    NASA Astrophysics Data System (ADS)

    Ajami, Aliasghar; Husinsky, Wolfgang; Tromayer, Maximilian; Gruber, Peter; Liska, Robert; Ovsianikov, Aleksandr

    2017-08-01

    To achieve efficient micro- and nanostructuring based on two-photon polymerization (2PP), the development and evaluation of specialized two-photon initiators (2PIs) are essential. Hence, a reliable method to determine the two-photon absorption (2PA) spectra of the synthesized 2PIs used for 2PP structuring is crucial. A technique by which absolute visible-to-near-infrared 2PA spectra of degenerate nature can be determined via performing a single dispersive white-light continuum (WLC) Z-scan has been realized. Using a dispersed white light beam containing 8 fs pulses at wavelengths ranging from 650 nm to 950 nm, the nonlinear transmittance as a function of the sample position can be measured for all spectral components by performing a single scan along the laser beam propagation direction. In this work, the 2PA spectrum of three different 2PIs was determined using this technique. 2PP structuring was also accomplished using the developed 2PIs at different wavelengths. Tuning the wavelength of the laser to match the peak of the 2PA spectra of the developed 2PIs resulted in lower intensity thresholds and facilitated higher structuring speeds. As an example, using M2CMK 2PI for 2PP, the scanning speed can be increased up to 5 folds when the laser wavelength is tuned to 760 nm (i.e., 2PA maximum) instead of the conventionally used 800 nm.

  1. Ultrafast terahertz spectroscopy for measuring carrier dynamics in nanoscale photovoltaic materials

    NASA Astrophysics Data System (ADS)

    Esenturk, Okan; Lane, Paul A.; Melinger, Joseph S.; Heilweil, Edwin J.

    2010-02-01

    Femtosecond pump-probe methods are useful tools for investigating transient electronic and vibrational states of conducting materials and molecular photochemistry. Ultraviolet and visible excitation pulses (<150 fs, <20 μJ, 400-800 nm) with time-delayed broadband terahertz (~500 GHz to 3 THz) probing pulses (Time-Resolved Terahertz Spectroscopy; TRTS) are used to measure linear spectroscopic transmission changes resulting from exciton and free carrier population in organic semiconducting thin films. Picosecond timescale exciton geminate recombination and longer-time free-carrier conduction in semiconductor polymers and nanolayered donor-acceptor films are discussed. Systems investigated with terahertz probe pulses include thiophene-based polymers (P3HT, PBTTT) studied as drop and spin-cast films on transparent quartz substrates. The relative conductivity of these films increases with increasing P3HT polymer molecular weight, structural regularity, and the fused rings in PBTTT further increases conduction. Recent studies of composite and nanolayered films (by vapor deposition) containing alternating Zn-phthalocyanine (ZnPc) and buckminsterfullerene (C60) also yield high conduction that scales linearly with the number of interfaces and total film thickness. We find evidence for a short-lived charge transfer state of C60 that decays within several picoseconds of excitation. In contrast, both composite and multilayered films exhibit long-lived THz dynamics that depends on the composition and structure of the films. The optimum composition for charge transfer within composite films is observed for a ~1:1 blend of ZnPc with C60 and a 4:1 blend of P3HT with Phenyl C61 Butyric Acid Methyl Ester (PCBM) while an increase in charge photo-generation with decreasing layer thickness (2 nm) exhibits the strongest THz signal. These findings parallel results for FET polymer transistor devices pointing to the advantage of optically measuring material properties before device test.

  2. Laser Remote Measurements of atmospheric pollutants (Las-R-Map): UV-Visible Laser system description and data processing

    NASA Astrophysics Data System (ADS)

    Sivakumar, V.; Wyk, H. V.

    Laser radar more popularly known as LIDAR LIght Detection And Ranging is becoming one of the most powerful techniques for active remote sensing of the earth s atmosphere Around the globe several new lidar systems have been developed based on the scientific interest Particularly the DIfferential Absorption Lidar DIAL technique is only one which can provide the better accuracy of measuring atmospheric pollutants Using modern advanced techniques and instrumentation a mobile DIAL system called laser remote measurements of atmospheric pollutants hear after referred as Las-R-Map is designed at National Laser Centre NLC --Pretoria 25 r 45 prime S 28 r 17 prime E Las-R-Map is basically used for measuring atmospheric pollutants applying the principle of absorption by constituents The system designed primarily to focus on the following pollutant measurements such as SO 2 CH 4 CO 2 NO 2 and O 3 In future the system could be used to measure few particulate matter between 2 5 mu m and 10 mu m Benzene Hg 1 3-butadiene H 2 S HF and Volatile Organic Compounds VOC Las-R-map comprises of two different laser sources Alexandrite and CO 2 optical receiver data acquisition and signal processor It uses alexandrite laser in the UV-Visible region from 200 nm to 800 nm and CO 2 laser in the Far-IR region from 9 2 mu m to 10 8 mu m Such two different laser sources make feasibility for studying the wide range of atmospheric pollutants The present paper is focused on technical details

  3. High repetition rate laser produced soft x-ray source for ultrafast x-ray absorption near edge structure measurements.

    PubMed

    Fourmaux, S; Lecherbourg, L; Harmand, M; Servol, M; Kieffer, J C

    2007-11-01

    Recent progress in high intensity ultrafast laser systems provides the opportunity to produce laser plasma x-ray sources exhibiting broad spectrum and high average x-ray flux that are well adapted to x-ray absorption measurements. In this paper, the development of a laser based x-ray absorption near edge structure (XANES) beamline exhibiting high repetition rate by using the Advanced Laser Light Source (ALLS) facility 100 Hz laser system (100 mJ, 35 fs at 800 nm) is presented. This system is based on a broadband tantalum solid target soft x-ray source and a grazing incidence grating spectrometer in the 1-5 nm wavelength range. To demonstrate the high potential of this laser based XANES technique in condensed matter physics, material science, or biology, measurements realized with several samples are presented: VO2 vanadium L edge, Si3N4 nitrogen K edge, and BPDA/PPD polyimide carbon K edge. The characteristics of this laser based beamline are discussed in terms of brightness, signal to noise ratio, and compared to conventional synchrotron broadband x-ray sources which allow achieving similar measurements. Apart from the very compact size and the relative low cost, the main advantages of such a laser based soft x-ray source are the picosecond pulse duration and the perfect synchronization between this x-ray probe and a laser pulse excitation which open the way to the realization of time resolved x-ray absorption measurements with picosecond range time resolution to study the dynamics of ultrafast processes and phase transition.

  4. High repetition rate laser produced soft x-ray source for ultrafast x-ray absorption near edge structure measurements

    SciTech Connect

    Fourmaux, S.; Lecherbourg, L.; Harmand, M.; Servol, M.; Kieffer, J. C.

    2007-11-15

    Recent progress in high intensity ultrafast laser systems provides the opportunity to produce laser plasma x-ray sources exhibiting broad spectrum and high average x-ray flux that are well adapted to x-ray absorption measurements. In this paper, the development of a laser based x-ray absorption near edge structure (XANES) beamline exhibiting high repetition rate by using the Advanced Laser Light Source (ALLS) facility 100 Hz laser system (100 mJ, 35 fs at 800 nm) is presented. This system is based on a broadband tantalum solid target soft x-ray source and a grazing incidence grating spectrometer in the 1-5 nm wavelength range. To demonstrate the high potential of this laser based XANES technique in condensed matter physics, material science, or biology, measurements realized with several samples are presented: VO{sub 2} vanadium L edge, Si{sub 3}N{sub 4} nitrogen K edge, and BPDA/PPD polyimide carbon K edge. The characteristics of this laser based beamline are discussed in terms of brightness, signal to noise ratio, and compared to conventional synchrotron broadband x-ray sources which allow achieving similar measurements. Apart from the very compact size and the relative low cost, the main advantages of such a laser based soft x-ray source are the picosecond pulse duration and the perfect synchronization between this x-ray probe and a laser pulse excitation which open the way to the realization of time resolved x-ray absorption measurements with picosecond range time resolution to study the dynamics of ultrafast processes and phase transition.

  5. Radiometric Measurement Comparison on the Integrating Sphere Source Used to Calibrate the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Landsat 7 Enhanced Thematic Mapper Plus (ETM+)

    PubMed Central

    Butler, James J.; Brown, Steven W.; Saunders, Robert D.; Johnson, B. Carol; Biggar, Stuart F.; Zalewski, Edward F.; Markham, Brian L.; Gracey, Paul N.; Young, James B.; Barnes, Robert A.

    2003-01-01

    As part of a continuing effort to validate the radiometric scales assigned to integrating sphere sources used in the calibration of Earth Observing System (EOS) instruments, a radiometric measurement comparison was held in May 1998 at Raytheon/Santa Barbara Remote Sensing (SBRS). This comparison was conducted in support of the calibration of the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Landsat 7 Enhanced Thematic Mapper Plus (ETM+) instruments. The radiometric scale assigned to the Spherical Integrating Source (SIS100) by SBRS was validated through a comparison with radiometric measurements made by a number of stable, well-characterized transfer radiometers from the National Institute of Standards and Technology (NIST), the National Aeronautics and Space Administration’s Goddard Space Flight Center (NASA’s GSFC), and the University of Arizona Optical Sciences Center (UA). The measured radiances from the radiometers differed by ±3 % in the visible to near infrared when compared to the SBRS calibration of the sphere, and the overall agreement was within the combined uncertainties of the individual measurements. In general, the transfer radiometers gave higher values than the SBRS calibration in the near infrared and lower values in the blue. The measurements of the radiometers differed by ±4 % from 800 nm to 1800 nm compared to the SBRS calibration of the sphere, and the overall agreement was within the combined uncertainties of the individual measurements for wavelengths less than 2200 nm. The results of the radiometric measurement comparison presented here supplement the results of previous measurement comparisons on the integrating sphere sources used to calibrate the Multi-angle Imaging SpectroRadiometer (MISR) at NASA’s Jet Propulsion Laboratory (JPL), Pasadena, CA and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) at NEC Corporation, Yokohama, Japan. PMID:27413606

  6. Radiometric Measurement Comparison on the Integrating Sphere Source Used to Calibrate the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Landsat 7 Enhanced Thematic Mapper Plus (ETM+).

    PubMed

    Butler, James J; Brown, Steven W; Saunders, Robert D; Johnson, B Carol; Biggar, Stuart F; Zalewski, Edward F; Markham, Brian L; Gracey, Paul N; Young, James B; Barnes, Robert A

    2003-01-01

    As part of a continuing effort to validate the radiometric scales assigned to integrating sphere sources used in the calibration of Earth Observing System (EOS) instruments, a radiometric measurement comparison was held in May 1998 at Raytheon/Santa Barbara Remote Sensing (SBRS). This comparison was conducted in support of the calibration of the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Landsat 7 Enhanced Thematic Mapper Plus (ETM+) instruments. The radiometric scale assigned to the Spherical Integrating Source (SIS100) by SBRS was validated through a comparison with radiometric measurements made by a number of stable, well-characterized transfer radiometers from the National Institute of Standards and Technology (NIST), the National Aeronautics and Space Administration's Goddard Space Flight Center (NASA's GSFC), and the University of Arizona Optical Sciences Center (UA). The measured radiances from the radiometers differed by ±3 % in the visible to near infrared when compared to the SBRS calibration of the sphere, and the overall agreement was within the combined uncertainties of the individual measurements. In general, the transfer radiometers gave higher values than the SBRS calibration in the near infrared and lower values in the blue. The measurements of the radiometers differed by ±4 % from 800 nm to 1800 nm compared to the SBRS calibration of the sphere, and the overall agreement was within the combined uncertainties of the individual measurements for wavelengths less than 2200 nm. The results of the radiometric measurement comparison presented here supplement the results of previous measurement comparisons on the integrating sphere sources used to calibrate the Multi-angle Imaging SpectroRadiometer (MISR) at NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) at NEC Corporation, Yokohama, Japan.

  7. Light absorption coefficient measurement of SOA using a UV-Visible spectrometer connected with an integrating sphere

    NASA Astrophysics Data System (ADS)

    Zhong, Min; Jang, Myoseon

    2011-08-01

    A method for measuring an aerosol light absorption coefficient ( B a) has been developed using a conventional UV-visible spectrometer equipped with an integrating sphere covering a wide range of wavelengths (280-800 nm). The feasibility of the proposed method was evaluated in both the transmittance mode (TUV-IS) and the reflective mode (RUV-IS) using the reference aerosol known for the cross-sectional area. The aerosol was collected on a conventional filter and measured for B a values. The resulting RUV-IS method was applied to measure light absorption of secondary organic aerosol (SOA). SOA was produced through photooxidation of different precursor hydrocarbons such as toluene, d-limonene and α-pinene in the presence of NO x (60-70 ppb) and inorganic seed aerosol using a 2-m 3 indoor Teflon film chamber. Of the three precursor hydrocarbons, the B a value of toluene SOA (0.574 m 2 g -1 at 350 nm) was the highest compared with B a values for α-pinene SOA (0.029 m 2 g -1) and d-limonene SOA (0.038 m 2 g -1). When d-limonene SOA or toluene SOA was internally mixed with neutral [(NH 4) 2SO 4] or acidic inorganic seed (NH 4HSO 4:H 2SO 4 = 1:1 by mole), the SOA showed 2-3 times greater B a values at 350 nm than the SOA with no seed. Aerosol aging with a light source for this study reduced B a values of SOA (e.g., on average 10% for toluene SOA and 30% for d-limonene SOA within 4 h). Overall, weak absorption appeared for chamber-generated SOA over wavelengths ranging from 280 to 550 nm, which fall into the sunlight spectrum.

  8. Differential absorption lidar measurements of H2O and O2 using a coherent white light continuum

    NASA Astrophysics Data System (ADS)

    Somekawa, T.; Manago, N.; Kuze, H.; Fujita, M.

    2016-10-01

    We applied a broadband and coherent white light continuum to differential absorption lidar (DIAL) detection of H2O and O2 profiles in the troposphere. The white light continuum can be generated by focusing high intensity femtosecond laser pulses at 800 nm into a Kr gas cell covering a broad spectral range from UV to mid-IR. Thus, the use of white light continuum potentially enables the DIAL measurement of several greenhouse and/or pollutant gases simultaneously while minimizing the lead time for developing a tunable light source. In order to demonstrate such capability, here we report the lidar measurements of H2O and O2. These molecular species exhibit absorption lines in the near IR region where relatively high intensity of the white light continuum is available. The white light continuum was transmitted through the atmosphere collinearly to the axis of a receiver telescope. Backscattered light was passed through bandpass filters (H2O On: 725 and 730 nm, H2O Off: 750 nm, O2 On: 760 nm, O2 Off: 780 nm), and was detected by a photomultiplier tube. The detection wavelengths were selected consecutively by rotating the filter wheels that contain five bandpass filters with an interval of 1 minute. In addition, we propose a method for retrieving vertical profiles of H2O by considering wavelength dependence of the aerosol extinction coefficient α and backscatter coefficient β. These results show that for achieving precise retrieval of H2O distribution, one needs to reduce the effect of aerosol temporal variations by means of long-time accumulation or simultaneous detection of the On- and Off-wavelength signals.

  9. Real-time measurements of fine & ultrafine sulfate aerosols in the marine Arctic atmosphere during springtime: Insights to Cloud Condensation Nuclei (CCN) sources

    NASA Astrophysics Data System (ADS)

    Sarda-Estève, R.; Sciare, J.

    2009-04-01

    Real-time measurements of Fine (A.D. < 800nm) and Ultra-Fine (A.D. < 200nm) ion composition of aerosols have been performed for a 2-week period during the late spring 2008 in the Arctic marine atmosphere (Ny Alesund, Spitzberg, Norway). These measurements were achieved using a modified PILS-IC system (Orsini et al., Atmos. Environ., 2003) enabling sequential measurements of the major anions (Cl, SO4, NO3) every 6min and were completed, for aerosol chemistry, by PM1 filter sampling for the determination of ions (anions, cations) and organic carbon (OC) content. These real-time measurements have shown that sulfate was the major contributor of the fine and ultra-fine aerosol mass and the major contributor to CCN. Consequently, organic aerosols are likely to play a minor role as CCN in the Arctic atmosphere at that time of the year (which corresponds to the oceanic productivity maximum). This is supported by the fact that production mechanism of marine organics is assumed to be similar to sea salt aerosols and that sea salt aerosols were not detectable in the ultrafine size fraction (<200 nm). Of particular interest, the ratio of UltraFine-to-Fine sulfate has shown a strong variability (ranging from 20 to 70%), that is not connected to Relative Humidity (e.g. growth to water uptake onto sulfate particules). On the other hand, this variability has shown to be in accordance with the MSA/SO4 mass ratio, which ratio is often used as a surrogate to trace the contribution of biogenic versus anthopogenic sulfate; higher ratios corresponding to higher contribution of biogenic sulfate (originating from the oxidation of DMS). The results presented suggest that, in the Arctic atmosphere (during late spring), biogenic sulfates are likely to produce CCN more efficiently than anthropogenic sources.

  10. A conjunct near-surface spectroscopy system for fix-angle and multi-angle continuous measurements of canopy reflectance and sun-induced chlorophyll fluorescence

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Fan, Yifeng; Zhang, Yongguang; Chou, Shuren; Ju, Weimin; Chen, Jing M.

    2016-09-01

    An automated spectroscopy system, which is divided into fix-angle and multi-angle subsystems, for collecting simultaneous, continuous and long-term measurements of canopy hyper-spectra in a crop ecosystem is developed. The fix-angle subsystem equips two spectrometers: one is HR2000+ (OceanOptics) covering the spectral range 200-1100 nm with 1.0 nm spectral resolution, and another one is QE65PRO (OceanOptics) providing 0.1 nm spectral resolution within the 730-780 nm spectral range. Both spectrometers connect a cosine-corrected fiber-optic fixed up-looking to collect the down-welling irradiance and a bare fiber-optic to measure the up-welling radiance from the vegetation. An inline fiber-optic shutter FOS-2x2-TTL (OceanOptics) is used to switch between input fibers to collect the signal from either the canopy or sky at one time. QE65PRO is used to permit estimation of vegetation Sun-Induced Fluorescence (SIF) in the O2-A band. The data collection scheme includes optimization of spectrometer integration time to maximize the signal to noise ratio and measurement of instrument dark currency. The multi-angle subsystem, which can help understanding bidirectional reflectance effects, alternatively use HR4000 (OceanOptics) providing 0.1 nm spectral resolution within the 680-800 nm spectral range to measure multi-angle SIF. This subsystem additionally includes a spectrometer Unispec-DC (PPSystems) featuring both up-welling and down-welling channels with 3 nm spectral resolution covering the 300-1100 nm spectral range. Two down-looking fiber-optics are mounted on a rotating device PTU-D46 (FLIR Systems), which can rotate horizontally and vertically at 10° angular step widths. Observations can be used to calculate canopy reflectance, vegetation indices and SIF for monitoring plant physiological processes.

  11. What quantum measurements measure

    NASA Astrophysics Data System (ADS)

    Griffiths, Robert B.

    2017-09-01

    A solution to the second measurement problem, determining what prior microscopic properties can be inferred from measurement outcomes ("pointer positions"), is worked out for projective and generalized (POVM) measurements, using consistent histories. The result supports the idea that equipment properly designed and calibrated reveals the properties it was designed to measure. Applications include Einstein's hemisphere and Wheeler's delayed choice paradoxes, and a method for analyzing weak measurements without recourse to weak values. Quantum measurements are noncontextual in the original sense employed by Bell and Mermin: if [A ,B ]=[A ,C ]=0 ,[B ,C ]≠0 , the outcome of an A measurement does not depend on whether it is measured with B or with C . An application to Bohm's model of the Einstein-Podolsky-Rosen situation suggests that a faulty understanding of quantum measurements is at the root of this paradox.

  12. Optical changes of porcine brain tissue after thermal coagulation

    NASA Astrophysics Data System (ADS)

    Schwarzmaier, Hans-Joachim; Goldbach, Thomas; Yaroslavsky, Ilya V.; Ulrich, Frank; Bettag, Martin; Kahn, Thomas; Kaufmann, Raimund

    1995-05-01

    Porcine brain tissue is a model for human brain structures in laser induced thermo-therapy. However, its optical properties including possible heat-related changes were basically unknown so far. To simulate laser coagulation, 12 specimens (6 grey and 6 white matter) were heated in a saline bath (80°C, 2 hours) and compared to 11 untreated samples (5 grey and 6 white matter). The optical constants were obtained from transmission (total and collimated) and reflection (diffuse) measurements using the inverse Monte-Carlo method. The absorption coefficient ((mu) a) of untreated grey substance decreased from 0.35 +/- 0.06/mm (340 nm) to 0.03 +/- 0.02/mm (800 nm). The scattering coefficient ((mu) s) varied between 20.42 +/- 3.65/mm (340 nm) and 6.85 +/- 2.07/mm (800 nm). The anisotropy factor (g) increased from 0.848 +/- 0.013 (340 nm) to 0.889 +/- 0.009 (800 nm). Coagulation increased (mu) a up to a factor of 2 (340-540 nm; p < 0.05), and (mu) s by a factor up to 3 (340-800 nm, all data p < 0.001) while g was decreased up to 18% (340-560 nm; p < 0.05). White substance exhibited a (mu) a between 0.24 +/- 0.07/mm (340 nm) and 0.04 +/- 0.02/mm (800 nm) while (mu) s varied between 26.72 +/- 9.10/mm (340 nm) and 21.78 +/- 3.88/mm (800 nm). The g-value increased from 0.561 +/- 0.180 (340 nm) to 0.834 +/- 0.068 (800 nm). Coagulation increased (mu) a by a factor up to 2 (340-800 nm; all data p < 0.05) while (mu) s and g remained unchanged. Thermal denaturation changes the absorption and scattering properties of porcine brain significantly.

  13. Unattended instruments for ground-based hyperspectral measurements: development and application for plant photosynthesis monitoring

    NASA Astrophysics Data System (ADS)

    Cogliati, S.; Rossini, M.; Meroni, M.; Barducci, A.; Julitta, T.; Colombo, R.

    2011-12-01

    The aim of the present work is the development of ground-based hyperspectral systems capable of collecting continuous and long-term hyperspectral measurements of the Earth-surface. The development of such instruments includes the optical design, the development of the data acquisition (Auto3S) and processing software as well as the definition of the calibration procedures. In particular an in-field calibration methodologie based on the comparison between field spectra and data modeled using Radiative Transfer (RT) approach has been proposed to regularly upgrade instrument calibration coefficients. Two different automatic spectrometric systems have been developed: the HyperSpectral Irradiometer (HSI) [Meroni et al., 2011] and the Multiplexer Radiometer Irradiometer (MRI) [Cogliati, 2011]. Both instruments are able to continuously measure: sun incoming irradiance (ETOT) and irradiance (ES, HSI)/radiance (LS, MRI) upwelling from the investigated surface. Both instruments employ two Ocean Optics HR4000 spectrometers sharing the same optical signal that allow to simultaneously collect "fine" (1 nm Full Width at Half Maximum, FWHM) spectra in the 400-1000 nm rangeand "ultra-fine" (0.1 nm FWHM) spectra within the 700-800 nm. The collected optical data allow to estimate biochemical/structural properties of vegetation (e.g. NDVI) as well as its photosynthetic efficiency through the Photochemical Reflectance Index (PRI) and the analysis of sun-induced chlorophyll Fluorescence in the O2-A Fraunhofer line (F@760). The automatic instruments were operated in coordination with eddy covariance flux tower measurements of carbon exchange in the framework of several field campaigns: HSI was employed in a subalpine pasture (2009-ongoing) (www.phenoalp.eu) while MRI was employed in 2009 in the Sen3Exp field survey promoted by the European Space Agency as consolidation study to the future mission Sentinel-3. Results show that the proposed instruments succeeded in collecting continuous

  14. Particle number emissions of motor traffic derived from street canyon measurements in a Central European city

    NASA Astrophysics Data System (ADS)

    Klose, S.; Birmili, W.; Voigtländer, J.; Tuch, T.; Wehner, B.; Wiedensohler, A.; Ketzel, M.

    2009-02-01

    A biennial dataset of ambient particle number size distributions (diameter range 4-800 nm) collected in urban air in Leipzig, Germany, was analysed with respect to the influence of traffic emissions. Size distributions were sampled continuously in 2005 and 2006 inside a street canyon trafficked by ca. 10 000 motor vehicles per day, and at a background reference site distant at 1.5 km. Auto-correlation analysis showed that the impact of fresh traffic emissions could be seen most intensely below particle sizes of 60 nm. The traffic-induced concentration increment at roadside was estimated by subtracting the urban background values from the street canyon measurement. To describe the variable dispersion conditions inside the street canyon, micro-meteorological dilution factors were calculated using the Operational Street Pollution Model (OSPM), driven by above-roof wind speed and wind direction observations. The roadside increment concentrations, dilution factor, and real-time traffic counts were used to calculate vehicle emission factors (aerosol source rates) that are representative of the prevailing driving conditions, i.e. stop-and-go traffic including episodes of fluent traffic flow at speeds up to 40 km h-1. The size spectrum of traffic-derived particles was essentially bimodal - with mode diameters around 12 and 100 nm, while statistical analysis suggested that the emitted number concentration varied with time of day, wind direction, particle size and fleet properties. Significantly, the particle number emissions depended on ambient temperature, ranging between 4.8 (±1.8) and 7.8 (±2.9).1014 p. veh-1 km-1 in summer and winter, respectively. A separation of vehicle types according to vehicle length suggested that lorry-like vehicles emit about 80 times more particle number than passenger car-like vehicles. Using nitrogen oxide (NOx) measurements, specific total particle number emissions of 338 p. (pg NOx)-1 were inferred. The calculated traffic emission factors

  15. Measure for measure

    NASA Astrophysics Data System (ADS)

    Weinberger, Peter

    2012-06-01

    The present system of measures for length, weight and capacity (volume) originates from scientific ideas expressed during the French Revolution in 1789. The history of a compatible unit of length, however, turns out to be less of a scientific but rather of a political character. Here reports to the Philosophical Magazine made in the first quarter of the nineteenth century are used to trace the cultural split between meters and inches, and between kilograms and pounds, that can be experienced in many parts of the world.

  16. Ideas: Measurement.

    ERIC Educational Resources Information Center

    Sovchik, Robert; Meconi, L. J.

    1994-01-01

    Presents measurement activities for K-3, 4-6, 5-6, and 7-8 grade levels. Activities include a measurement scavenger hunt, using a clinometer to measure angles of elevation, estimating the age of trees, measuring the height of a tree, and measuring objects at a distance. Includes reproducible worksheets. (MDH)

  17. Ideas: Measurement.

    ERIC Educational Resources Information Center

    Sovchik, Robert; Meconi, L. J.

    1994-01-01

    Presents measurement activities for K-3, 4-6, 5-6, and 7-8 grade levels. Activities include a measurement scavenger hunt, using a clinometer to measure angles of elevation, estimating the age of trees, measuring the height of a tree, and measuring objects at a distance. Includes reproducible worksheets. (MDH)

  18. Measurement Technology

    NASA Technical Reports Server (NTRS)

    1972-01-01

    New and improved materials, equipment, and techniques in measurement technology, developed by the aerospace industry, are presented for economic development in other industries. The developments are grouped as follows: (1) surface measurement, (2) alignment and orientation of bodies, (3) fluid measurement, (4) linear and angular measurements, and (5) force measurements.

  19. Body Measurement.

    ERIC Educational Resources Information Center

    Neufeld, K. Allen

    1989-01-01

    Described are activities for measuring the human body. The activities include measurements and calculations, calculating volume and density, problems related to body measurement, and using a nomogram. Several charts, illustrations, and a nomogram are provided. (YP)

  20. Body Measurement.

    ERIC Educational Resources Information Center

    Neufeld, K. Allen

    1989-01-01

    Described are activities for measuring the human body. The activities include measurements and calculations, calculating volume and density, problems related to body measurement, and using a nomogram. Several charts, illustrations, and a nomogram are provided. (YP)

  1. Neutron measurements

    SciTech Connect

    McCall, R.C.

    1981-01-01

    Methods of neutron detection and measurement are discussed. Topics include sources of neutrons, neutrons in medicine, interactions of neutrons with matter, neutron shielding, neutron measurement units, measurement methods, and neutron spectroscopy. (ACR)

  2. Uncertainty in vegetation products derived from field spectral measurements: an error budget approach

    NASA Astrophysics Data System (ADS)

    Anderson, K.; Dungan, J. L.

    2008-12-01

    vegetation. The grey panel data showed a wavelength- dependent pattern, similar to the NEdL laboratory trend, but subsequent error propagation of laboratory- derived NEdL through to a reflectance factor showed that the laboratory characterisation was unable to account for all of the uncertainty measured in the field. Therefore the estimate of u gained from field data more closely represents the reproducibility of measurements where atmospheric, solar zenith and instrument-related uncertainties are combined. Results on vegetation u showed a stronger wavelength dependency with higher standard uncertainties beyond the vegetation red-edge than in visible wavelengths (maximum = 0.015 at 800 nm, and 0.004 at 550nm). The results demonstrate that standard uncertainties of field reflectance data have a spectral dependence and exceed laboratory-derived estimates of instrument "noise". Uncertainty of this type must be taken into account when statistically testing for differences in field spectra. Improved reporting of standard uncertainties from field experiments will foster progress in remote sensing science.

  3. When Measurement Benefits the Measured

    DTIC Science & Technology

    2014-04-23

    1 When Measurement Benefits the Measured Kasunic & Nichols, April 23, 2014 © 2014 Carnegie Mellon University Mark Kasunic Senior Member of...performance measurement , and practical measurement and analysis approaches that help individuals and teams improve their technical performance. Mark has an...extensive list of technical publications and conference presentations addressing software engineering and measurement . Before joining the SEI, Mark

  4. Transient absorption studies of vibrational relaxation and photophysics of Prussian blue and ruthenium purple nanoparticles

    NASA Astrophysics Data System (ADS)

    Weidinger, D.; Brown, D. J.; Owrutsky, J. C.

    2011-03-01

    Transient infrared and visible absorption studies have been used to characterize vibrational and electronic dynamics of Prussian blue (PB) and ruthenium purple (RP) nanoparticles produced and characterized in AOT reverse micelles. Studies include excitation and probing with both infrared (near 2000 cm-1) and visible (800 nm) pulses. From IR pump-IR probe measurements of the CN stretching bands, vibrational population lifetimes are determined to be 32 ± 4 ps for PB and 44 ± 14 ps for RP. These times are longer than those for ferrocyanide (4 ps) and ruthenocyanide (4 ps) in normal water and are closer to the times for these species in heavy water (25-30 ps) and for ferrocyanide in formamide (43 ps). The PB and RP lifetimes are also longer than those (<15 ps) previously measured for CN stretching bands following intervalence excitation and back-electron transfer (BET) for dinuclear mixed-valence compounds containing Fe, Ru, and Os in heavy water and formamide [A. V. Tivansky, C. F. Wang, and G. C. Walker, J. Phys. Chem. A 107, 9051 (2003)]. In 800 nm pump-IR probe experiments on RP and PB, transient IR spectra and decay curves are similar to those with IR excitation; a ground state bleach and a red shifted (by ˜40 cm-1) excited state decay are observed. These results for the visible pumping are consistent with rapid (<1 ps) BET resulting in population in the ground electronic state with vibrational excitation in the CN mode. In addition, transient absorption studies were performed for PB and RP probing with visible light using both visible and IR excitation. The early time response for the 800 nm pump-800 nm probe of PB exhibits an instrument-limited, subpicosecond bleach followed by an absorption, which is consistent with the previously reported results [D. C. Arnett, P. Vohringer, and N. F. Scherer, J. Am. Chem. Soc. 117, 12262 (1995)]. The absorption exhibits a biexponential decay with decay times of 9 and 185 ps, which could have been attributed to the CN band

  5. Aerosol size distribution and new particle formation in western Yangtze River Delta of China: two-year measurement at the SORPES station

    NASA Astrophysics Data System (ADS)

    Qi, X. M.; Ding, A. J.; Nie, W.; Petäjä, T.; Kerminen, V.-M.; Herrmann, E.; Xie, Y. N.; Zheng, L. F.; Manninen, H.; Aalto, P.; Sun, J. N.; Xu, Z. N.; Chi, X. G.; Huang, X.; Boy, M.; Virkkula, A.; Yang, X.-Q.; Fu, C. B.; Kulmala, M.

    2015-04-01

    Aerosol particles play important roles in regional air quality and global climate change. In this study, we analyzed two-year (2011-2013) of measurements of submicron particles (6-800 nm) at a suburban site in western Yangtze River delta (YRD) of East China. The number concentrations (NCs) of particles in the nucleation, Aitken and accumulation modes were 5300 ± 5500, 8000 ± 4400, 5800 ± 3200 cm-3, respectively. Number concentrations and size distributions of submicron particles were also influenced by long-range and regional transport of air masses. The highest and lowest accumulation mode particle number concentrations were observed in air masses from YRD and coastal region, respectively. Continental air masses from inland had the highest concentrations of nucleation mode particles. New particle formation (NPF) events, apparent in 44% of the effective measurement days, occurred frequently in all the seasons except winter. Radiation and pre-existing particles were found to be the main factors influencing the occurrence of NPF events. The particle formation rate was the highest in spring (3.6 ± 2.4 cm-3 s-1), whereas the particle growth rate had the highest values in summer (12.8 ± 4.4 nm h-1). The formation rate was typically high in relatively clean air masses, whereas the growth rate tended to be high in the polluted YRD air masses. The frequency of NPF events and the growth rate showed a strong year-to-year difference. In the summer of 2013, associated with a multi-week heat wave and photochemical pollution, NPF events occurred more frequently and the growth rate was much higher than in the same period of 2012. The difference in the location and strength of sub-tropical High, which influences the air mass transport pathways and solar radiation, seems to be the driving cause for year-to-year differences. This study reported the longest continuous measurement records of submicron particles in the East China and gained a comprehensive understanding of the

  6. Measuring Resilience.

    ERIC Educational Resources Information Center

    O'Neal, Marcia R.

    Locating and selecting an instrument that measures resilience is no simple task. This document provides information about several measures of resilience or hardiness that have been used in recent years. The discussion of each measure includes information about its origins, a description of the measure and its uses, and a discussion of the…

  7. Measurement Error. For Good Measure....

    ERIC Educational Resources Information Center

    Johnson, Stephen; Dulaney, Chuck; Banks, Karen

    No test, however well designed, can measure a student's true achievement because numerous factors interfere with the ability to measure achievement. These factors are sources of measurement error, and the goal in creating tests is to have as little measurement error as possible. Error can result from the test design, factors related to individual…

  8. An Automated System for Measuring Microphysical and Radiative Cloud Characteristics from a Tethered Balloon

    SciTech Connect

    Dr. Paul Lawson

    2004-03-15

    OAK-B135 The rate of climate change in polar regions is now felt to be a harbinger of possible global warming. Long-lived, relatively thin stratus clouds play a predominant role in transmitting solar radiation and trapping long wave radiation emitted from open water and melt ponds. In situ measurements of microphysical and radiative properties of Arctic and Antarctic stratus clouds are needed to validate retrievals from remote measurements and simulations using numerical models. While research aircraft can collect comprehensive microphysical and radiative data in clouds, the duration of these aircraft is relatively short (up to about 12 hours). During the course of the Phase II research, a tethered balloon system was developed that supports miniaturized meteorological, microphysical and radiation sensors that can collect data in stratus clouds for days at a time. The tethered balloon system uses a 43 cubic meter balloon to loft a 17 kg sensor package to altitudes u p to 2 km. Power is supplied to the instrument package via two copper conductors in the custom tether. Meteorological, microphysical and radiation data are recorded by the sensor package. Meteorological measurements include pressure, temperature, humidity, wind speed and wind direction. Radiation measurements are made using a 4-pi radiometer that measures actinic flux at 500 and 800 nm. Position is recorded using a GPS receiver. Microphysical data are obtained using a miniaturized version of an airborne cloud particle imager (CPI). The miniaturized CPI measures the size distribution of water drops and ice crystals from 9 microns to 1.4 mm. Data are recorded onboard the sensor package and also telemetered via a 802.11b wireless communications link. Command signals can also be sent to the computer in the sensor package via the wireless link. In the event of a broken tether, a GMRS radio link to the balloon package is used to heat a wire that burns 15 cm opening in the top of the balloon. The balloon and

  9. Effects of inelastic radiative processes on the determination of water-leaving spectral radiance from extrapolation of underwater near-surface measurements.

    PubMed

    Li, Linhai; Stramski, Dariusz; Reynolds, Rick A

    2016-09-01

    Extrapolation of near-surface underwater measurements is the most common method to estimate the water-leaving spectral radiance, Lw(λ) (where λ is the light wavelength in vacuum), and remote-sensing reflectance, Rrs(λ), for validation and vicarious calibration of satellite sensors, as well as for ocean color algorithm development. However, uncertainties in Lw(λ) arising from the extrapolation process have not been investigated in detail with regards to the potential influence of inelastic radiative processes, such as Raman scattering by water molecules and fluorescence by colored dissolved organic matter and chlorophyll-a. Using radiative transfer simulations, we examine high-depth resolution vertical profiles of the upwelling radiance, Lu(λ), and its diffuse attenuation coefficient, KLu (λ), within the top 10 m of the ocean surface layer and assess the uncertainties in extrapolated values of Lw(λ). The inelastic processes generally increase Lu and decrease KLu in the red and near-infrared (NIR) portion of the spectrum. Unlike KLu in the blue and green spectral bands, KLu in the red and NIR is strongly variable within the near-surface layer even in a perfectly homogeneous water column. The assumption of a constant KLu with depth that is typically employed in the extrapolation method can lead to significant errors in the estimate of Lw. These errors approach ∼100% at 900 nm, and the desired threshold of 5% accuracy or less cannot be achieved at wavelengths greater than 650 nm for underwater radiometric systems that typically take measurements at depths below 1 m. These errors can be reduced by measuring Lu within a much shallower surface layer of tens of centimeters thick or even less at near-infrared wavelengths longer than 800 nm, which suggests a

  10. First derivative versus absolute spectral reflectance of citrus varieties

    NASA Astrophysics Data System (ADS)

    Blazquez, Carlos H.; Nigg, H. N.; Hedley, Lou E.; Ramos, L. E.; Sorrell, R. W.; Simpson, S. E.

    1996-06-01

    Spectral reflectance measurements from 400 to 800 nm were taken from immature and mature leaves of grapefruit ('McCarty' and 'Rio Red'), 'Minneola' tangelo, 'Satsuma' mandarin, 'Dancy' tangerine, 'Nagami' oval kumquat, and 'Valencia' sweet orange, at the Florida Citrus Arboretum, Division of Plant Industry, Winter Haven, Florida. Immature and mature leaves of 'Minneola' tangelo had greater percent reflectance in the 400 to 800 nm range than the other varieties and leaf ages measured. The slope of the citrus spectral curves in the 800 nm range was not as sharp as conventional spectrometers, but had a much higher reflectance value than those obtained with a DK-2 spectrometer. Statistical analyses of absolute spectral data yielded significant differences between mature and immature leaves and between varieties. First derivative data analyses did not yield significant differences between varieties.

  11. Temperature measurement

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003400.htm Temperature measurement To use the sharing features on this page, please enable JavaScript. The measurement of body temperature can help detect illness. It can also monitor ...

  12. Construction measurements

    SciTech Connect

    Barry, B.A.

    1988-01-01

    This text/reference on construction measurements contains material concerning electronic surveying and remote sensing. New to this edition is coverage of the GPS satellite positioning system, electronic distance measurement (EDM), laser sweep, calculator techniques, radial surveying and tracking, Loran-C, inertial navigation surveying, 3-point resection, computer software, and electronic fieldbooks. It covers the difference of elevation, angle measurements and directions, coordinate surveying and layout, offshore measurements, and random field and office techniques.

  13. Measuring circuit

    DOEpatents

    Sun, Shan C.; Chaprnka, Anthony G.

    1977-01-11

    An automatic gain control circuit functions to adjust the magnitude of an input signal supplied to a measuring circuit to a level within the dynamic range of the measuring circuit while a log-ratio circuit adjusts the magnitude of the output signal from the measuring circuit to the level of the input signal and optimizes the signal-to-noise ratio performance of the measuring circuit.

  14. Measure Lines

    ERIC Educational Resources Information Center

    Crissman, Sally

    2011-01-01

    One tool for enhancing students' work with data in the science classroom is the measure line. As a coteacher and curriculum developer for The Inquiry Project, the author has seen how measure lines--a number line in which the numbers refer to units of measure--help students not only represent data but also analyze it in ways that generate…

  15. Precision Measurement.

    ERIC Educational Resources Information Center

    Radius, Marcie; And Others

    The manual provides information for precision measurement (counting of movements per minute of a chosen activity) of achievement in special education students. Initial sections give guidelines for the teacher, parent, and student to follow for various methods of charting behavior. It is explained that precision measurement is a way to measure the…

  16. Measurement fundamentals

    SciTech Connect

    Webb, R.A.

    1995-12-01

    The need to have accurate petroleum measurement is obvious. Petroleum measurement is the basis of commerce between oil producers, royalty owners, oil transporters, refiners, marketers, the Department of Revenue, and the motoring public. Furthermore, petroleum measurements are often used to detect operational problems or unwanted releases in pipelines, tanks, marine vessels, underground storage tanks, etc. Therefore, consistent, accurate petroleum measurement is an essential part of any operation. While there are several methods and different types of equipment used to perform petroleum measurement, the basic process stays the same. The basic measurement process is the act of comparing an unknown quantity, to a known quantity, in order to establish its magnitude. The process can be seen in a variety of forms; such as measuring for a first-down in a football game, weighing meat and produce at the grocery, or the use of an automobile odometer.

  17. Multilevel Interventions: Measurement and Measures

    PubMed Central

    Charns, Martin P.; Alligood, Elaine C.; Benzer, Justin K.; Burgess, James F.; Mcintosh, Nathalie M.; Burness, Allison; Partin, Melissa R.; Clauser, Steven B.

    2012-01-01

    Background Multilevel intervention research holds the promise of more accurately representing real-life situations and, thus, with proper research design and measurement approaches, facilitating effective and efficient resolution of health-care system challenges. However, taking a multilevel approach to cancer care interventions creates both measurement challenges and opportunities. Methods One-thousand seventy two cancer care articles from 2005 to 2010 were reviewed to examine the state of measurement in the multilevel intervention cancer care literature. Ultimately, 234 multilevel articles, 40 involving cancer care interventions, were identified. Additionally, literature from health services, social psychology, and organizational behavior was reviewed to identify measures that might be useful in multilevel intervention research. Results The vast majority of measures used in multilevel cancer intervention studies were individual level measures. Group-, organization-, and community-level measures were rarely used. Discussion of the independence, validity, and reliability of measures was scant. Discussion Measurement issues may be especially complex when conducting multilevel intervention research. Measurement considerations that are associated with multilevel intervention research include those related to independence, reliability, validity, sample size, and power. Furthermore, multilevel intervention research requires identification of key constructs and measures by level and consideration of interactions within and across levels. Thus, multilevel intervention research benefits from thoughtful theory-driven planning and design, an interdisciplinary approach, and mixed methods measurement and analysis. PMID:22623598

  18. Comparison of measured and calculated collision efficiencies at low temperatures

    NASA Astrophysics Data System (ADS)

    Nagare, B.; Marcolli, C.; Stetzer, O.; Lohmann, U.

    2015-12-01

    Interactions of atmospheric aerosols with clouds influence cloud properties and modify the aerosol life cycle. Aerosol particles act as cloud condensation nuclei and ice nucleating particles or become incorporated into cloud droplets by scavenging. For an accurate description of aerosol scavenging and ice nucleation in contact mode, collision efficiency between droplets and aerosol particles needs to be known. This study derives the collision rate from experimental contact freezing data obtained with the ETH CoLlision Ice Nucleation CHamber (CLINCH). Freely falling 80 μm diameter water droplets are exposed to an aerosol consisting of 200 and 400 nm diameter silver iodide particles of concentrations from 500 to 5000 and 500 to 2000 cm-3, respectively, which act as ice nucleating particles in contact mode. The experimental data used to derive collision efficiency are in a temperature range of 238-245 K, where each collision of silver iodide particles with droplets can be assumed to result in the freezing of the droplet. An upper and lower limit of collision efficiency is also estimated for 800 nm diameter kaolinite particles. The chamber is kept at ice saturation at a temperature range of 236 to 261 K, leading to the slow evaporation of water droplets giving rise to thermophoresis and diffusiophoresis. Droplets and particles bear charges inducing electrophoresis. The experimentally derived collision efficiency values of 0.13, 0.07 and 0.047-0.11 for 200, 400 and 800 nm particles are around 1 order of magnitude higher than theoretical formulations which include Brownian diffusion, impaction, interception, thermophoretic, diffusiophoretic and electric forces. This discrepancy is most probably due to uncertainties and inaccuracies in the description of thermophoretic and diffusiophoretic processes acting together. This is, to the authors' knowledge, the first data set of collision efficiencies acquired below 273 K. More such experiments with different droplet and

  19. The study on the light absorption and transmission laws of the blood components

    NASA Astrophysics Data System (ADS)

    Chen, Zulin; Lai, Yan; Ge, Haiyan; Xu, Zhangrui

    2003-12-01

    Aim: This experiment studied the light absorption laws of the blood components between 240-800nm. Methods: The absorbance and transmittance of the blood components were measured by applying a model UV-365 double beam scanning spectrophotometer with an integral sphere, between 240-800nm. Results: The results show: 1) The absorbance and transmittance laws resemble each other in blood of the Groups A,B,AB and O. 2) Between 600-800nm, the absorbances of the whole blood, erythrocyte, leukocyte, plasma and serum are less than 5%, while the transmittances of them are more than 95%. 3) To erythrocyte and lymphocyte, typical absorption peaks appear at 416.57+/-1.90, 542.71+/-1.80, 578.57+/-1.81nm. Conclusion: These results provide some useful parameters for the optical properties of blood and the clinical applications.

  20. Measurement Uncertainty

    NASA Astrophysics Data System (ADS)

    Koch, Michael

    Measurement uncertainty is one of the key issues in quality assurance. It became increasingly important for analytical chemistry laboratories with the accreditation to ISO/IEC 17025. The uncertainty of a measurement is the most important criterion for the decision whether a measurement result is fit for purpose. It also delivers help for the decision whether a specification limit is exceeded or not. Estimation of measurement uncertainty often is not trivial. Several strategies have been developed for this purpose that will shortly be described in this chapter. In addition the different possibilities to take into account the uncertainty in compliance assessment are explained.

  1. Dispersion measurement on chirped mirrors at arbitrary incidence angle and polarization state (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kovacs, Mate; Somoskoi, Tamas; Seres, Imre; Borzsonyi, Adam; Sipos, Aron; Osvay, Károly

    2017-05-01

    spectrometer we could investigate over the 500-1300 nm spectral range. We also measured the mirrors with broadband oscillator pulses, and we found that the dispersion was the same for both light source. Group Delay Dispersion was obtained with a ±2 fs^2 accuracy from the Fourier Transform method of the interference fringes. Using an adjunct mirror, we made possible to change continuously the angle of incidence at the chirped mirror within 3 and 55°. On the input part of the interferometer we placed a wire-grid polarizer, and sensitivity of the chirp mirrors to the polarization state have been measured at different incidence angles. To present the flexibility of the device we scanned two different compressor mirrors with +100 fs^2 and -500 fs^2 at the 800 nm central wavelength. We separately developed an optical arrangement to detect Group Delay shift between s and p polarization reflections of large aperture chirped compressor mirrors and we found that it's below the detection limit, so further investigation will be necessary. 1. M. Ivanov, P. B. Corkum, T. Zuo, and A. Bandrauk, Routes to Control of Intense-Field Atomic Polarizability, Phys. Rev. Lett. 74, 1995

  2. Asbestos Measurement

    EPA Science Inventory

    Environmental engineers are generally concerned with two types of air pollutants, gases and particulate matter (PM). Generally, the mass of PM falling in two size categories is measured, i.e. ≤2.5 µm diameter, and between 2.5 µm and 10 µm diameter. These measurements are taken by...

  3. Asbestos Measurement

    EPA Science Inventory

    Environmental engineers are generally concerned with two types of air pollutants, gases and particulate matter (PM). Generally, the mass of PM falling in two size categories is measured, i.e. ≤2.5 µm diameter, and between 2.5 µm and 10 µm diameter. These measurements are taken by...

  4. Unobtrusive Measures.

    ERIC Educational Resources Information Center

    Kagan, Spencer

    Unobtrusive measures in psychological experiments are discussed. Six levels of unobtrusiveness are (1) Complete Unobtrusiveness, (2) Hidden Mechanical Intervention, (3) Hidden Observer, (4) Impinging Mechanical Intervention Not Recognized as Experimental, (5) Impinging Observer, and (6) Unobtrusive Measures within an Experimental Setting. Each of…

  5. Psychological Measurement.

    ERIC Educational Resources Information Center

    Dawes, Robyn M.

    1994-01-01

    L. L. Thurstone's revolutionary article resulted in the development of many representational measurement models, but the introduction of "true measurement" in social, attitudinal, and personality psychology did not yield the progress Thurstone envisioned. This specific model is seldom used in these areas today. (SLD)

  6. Quality measurement

    PubMed Central

    Sanders, Amy E.; Cohen, Adam B.; Bever, Christopher T.

    2014-01-01

    Summary The Centers for Medicare and Medicaid Services (CMS) is shifting from volume-based to value-based reimbursement of health care services. Measuring the value of health care requires measurement of quality and cost. We provide an overview of quality measurement and review a well-known and widely used conceptual model for assessing quality: structure, process, and outcome. We highlight the advantages and disadvantages of using these types of metrics. We then use this conceptual model to describe prominent CMS programs such as the Physician Quality Reporting System, Physician Compare Web site, and the Medicare Shared Savings Plan. We highlight 2 recent trends: the increasing use of outcome measures to supplement process measures and the public reporting of quality. PMID:25317378

  7. Optical Kerr effect of tRNA solution induced by femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Kucia, Weronika E.; Sharma, Gargi; Joseph, Cecil S.; Sarbak, Szymon; Oliver, Cameron; Dobek, Andrzej; Giles, Robert H.

    2016-10-01

    The optical Kerr effect (OKE) in a transfer ribonucleic acid (tRNA) solution induced by femtosecond pulses of linearly polarized pump light (λi = 800 nm) and sounded by probe light (λp = 800 nm) was studied. The measurements were performed to find nonlinear optical parameters describing a single molecule (molecular Kerr constant K, mean nonlinear third order optical polarizability cpi) and to compare them with our previous OKE results obtained in ns and ps time range. The OKE experiment has proven to be an efficient method to obtain the nonlinear parameters of single molecules in solution, which reflects dynamic structure changes.

  8. Odor Measurement

    NASA Astrophysics Data System (ADS)

    Iwasaki, Yoshiharu

    It has been said that the measurement of odor is very difficult. Because almost odor samples have a large number of chemicals, and these olfactory thresholds are very low levels. For these reasons, the instrumental measurement method is not good, and the olfactory sensory methods are adopted in the world. Odor concentration scale had been widely used in the world. But, the measurement methods of odor concentration scale differ depend on the country. For example, in Japan, Triangle Odor Bag Method has been used from 30 years ago. Dynamic olfactometer is used in European countries. Triangle Odor Bag Method is introduced at the end of this paper.

  9. MEASURING PROJECTOR

    DOEpatents

    Franck, J.V.; Broadhead, P.S.; Skiff, E.W.

    1959-07-14

    A semiautomatic measuring projector particularly adapted for measurement of the coordinates of photographic images of particle tracks as prcduced in a bubble or cloud chamber is presented. A viewing screen aids the operator in selecting a particle track for measurement. After approximate manual alignment, an image scanning system coupled to a servo control provides automatic exact alignment of a track image with a reference point. The apparatus can follow along a track with a continuous motion while recording coordinate data at various selected points along the track. The coordinate data is recorded on punched cards for subsequent computer calculation of particle trajectory, momentum, etc.

  10. An Optical Streaking Method for Measuring Femtosecond Electron Bunches

    SciTech Connect

    Ding, Yuantao; Bane, Karl L.F.; Huang, Zhirong; /SLAC

    2011-12-14

    are the right direction to achieve a better resolution. For example, by choosing an X-band transverse deflecting cavity, the expected resolution for LCLS beam with 4.3 GeV is about 1 fs rms. Typically the rf breakdown threshold and the power source availability prevent going to even higher voltage and frequency. With the highly-developed laser techniques, we can choose to streak the beam at optical frequencies. By jumping from rf to optical frequency, the wavelength is shortening by 4 to 5 orders. With an electron bunch length shorter than half period of the laser, we can apply the similar rf deflecting or zero-phasing method for e-beam bunch length measurements using a high-power laser. A short wiggler is required to provide interaction between the electron and the laser. For example, to measure the e-beam at the order of 1 m rms length, a laser with its wavelength of 10 {mu}m may be considered. For a typical few GeV e-beam, the wiggler period has to be large to satisfy the resonance condition. Also, if the e-beam is longer than one laser period, the different modulation periods will overlap and we cannot distinguish them. So this method is so far limited by the achievable long-wavelength laser power. To get an effective modulation on an e-beam of 4.3 GeV, the required laser power is about a few tens GW. In this paper we propose to adopt a high-power Ti:Sapphire laser (wavelength of 800 nm), and use the slope in the intensity envelope to distinguish the different modulation periods. First an ultrashort electron beam interacts with the Ti:Sapphire laser in a wiggler, where the electron energy is modulated at the same periods of the laser. If the laser pulse is long and the short electron bunch is overlapped (in time) with the middle part of the laser, such as the setup at LCLS laser heater, the different energy modulation periods on the electron beam will be overlapped on the energy profile. In this conditionwe typically have a double-horn distribution of the energy

  11. Study of Infra Red femtosecond laser induced aerosols using Transmission Electron Microscopy and Low Pressure Impactor: implications for LA-ICP-MS measurements

    NASA Astrophysics Data System (ADS)

    D'Abzac, F.; Seydoux-Guillaume, A.; Poitrasson, F.; Freydier, R.; Datas, L.

    2009-12-01

    Processes linked to the creation of laser induced aerosols are not yet fully understood, especially in the Infra Red femtosecond regime. It is of great interest to understand these mechanisms in order to better constrain chemical fractionation observed on LA-ICP-MS signals. A meticulous study of particles produced by IR-fs laser ablation (λ=800nm, τ=60fs, E=0,1-1mJ/pulse, f=5Hz) has been conducted on a wide variety of samples (phosphate, silicates, oxides, glass and metals), using transmission electron microscopy (Bright field TEM and EDS). Afterwards, observations using TEM coupled with focused ion beam (FIB) preparation have been performed on craters, to study the laser induced redeposition structure and chemistry and bring comparison with related aerosols. Finally, quantitative data have been collected using a low pressure impactor (LPI) device. Observed aerosols always consist in amorphous dark beads (30-150nm diameter) and more or less developed clusters (>100nm) of smaller particles (10-15 nm diameter). Their composition differs from each other and from the initial sample. Counting reveals a decreasing density of particle over 10min of ablation, while size distribution appears Gaussian, monomodal and remains centered on 90-100nm. Craters in monazite (phosphate, Moacir, Itembe, Brazil) show two different domains. Strained areas, induced by very high pressure resulting from matter removal, and, on the top, a thin layer (~250nm in the single shot crater for E=0,1mJ/pulse) probably melted then annealed. Qualitative EDS data from the latter shows the same composition as unshocked sample. Data allows an advanced reconstruction of events driving matter from crater digging through plasma and finally into metastable particles. Numerous theoretical[1] and experimental[2,3] reports, focused on each successive stage, help putting forward the hypothesis of a single complex process of condensation/coalescence. Direct qualitative and quantitative measurements on aerosols

  12. Environmental Measurement

    EPA Pesticide Factsheets

    Environmental measurement is any data collection activity involving the assessment of chemical, physical, or biological factors in the environment which affect human health. Learn more about these programs and tools that aid in environmental decisions

  13. MEASURING CIRCUIT

    DOEpatents

    Mahoney, J.R.

    1963-01-29

    A measuring and balancing arrangement for mass spectrometers permits the ready determination of isotopic ratios and mole and weight percentages by employing a selection of amplifier input resistors to vary sensitivity in a bridge arrangement. (AEC)

  14. ["Emergency measures"].

    PubMed

    Louis, Jean-Jacques

    2012-03-01

    This article deals with the impact of health crisis on governance of public health. It tries to show that, in accordance with the thought of Michel Foucault, emergency measures issued during health crisis are akin to those issued during wartime.

  15. Measurement uncertainty.

    PubMed

    Bartley, David; Lidén, Göran

    2008-08-01

    The reporting of measurement uncertainty has recently undergone a major harmonization whereby characteristics of a measurement method obtained during establishment and application are combined componentwise. For example, the sometimes-pesky systematic error is included. A bias component of uncertainty can be often easily established as the uncertainty in the bias. However, beyond simply arriving at a value for uncertainty, meaning to this uncertainty if needed can sometimes be developed in terms of prediction confidence in uncertainty-based intervals covering what is to be measured. To this end, a link between concepts of accuracy and uncertainty is established through a simple yet accurate approximation to a random variable known as the non-central Student's t-distribution. Without a measureless and perpetual uncertainty, the drama of human life would be destroyed. Winston Churchill.

  16. Measuring Learning

    ERIC Educational Resources Information Center

    Ashbrook, Peggy

    2011-01-01

    Teachers assess children's learning to understand how to make their instruction more effective. Early childhood assessment must take into account the typically uneven development of children and their cultural contexts. The author assessed what a group of four-year-olds knew about measurement as she talked about how much water had filled a rain…

  17. Measuring Up

    ERIC Educational Resources Information Center

    Hart, Holly; Healey, Kaleen; Sporte, Susan E.

    2014-01-01

    Moving teacher evaluation systems from measuring teachers' performance to improving their practice requires much greater attention to communication and support. In the fall of 2012, Chicago Public Schools (CPS) instituted a sweeping reform of its teacher evaluation system with the introduction of REACH Students (Recognizing Educators Advancing…

  18. Measuring Learning

    ERIC Educational Resources Information Center

    Ashbrook, Peggy

    2011-01-01

    Teachers assess children's learning to understand how to make their instruction more effective. Early childhood assessment must take into account the typically uneven development of children and their cultural contexts. The author assessed what a group of four-year-olds knew about measurement as she talked about how much water had filled a rain…

  19. Measured Success

    ERIC Educational Resources Information Center

    Keating, Tom

    2009-01-01

    Many students think custodians are hired to pick up after them. And sometimes adult workers voice similarly negative impressions. What can education institutions do about this negative and improper thinking? Because of heightened concerns about invisible pathogens such as MRSA and swine flu, improved technologies are available to measure bacteria…

  20. Measuring Leadership.

    ERIC Educational Resources Information Center

    Lashway, Larry

    1998-01-01

    Principals have two reasons to wonder about the whole concept of leadership. First, they are responsible for identifying leadership in others; and second, they must be analytical and reflective about their own capabilities. Consequently, there is always demand for valid and reliable measurement of leadership qualities. This issue reviews recent…

  1. Measuring Resilience.

    PubMed

    Hoffman, Robert R; Hancock, P A

    2017-06-01

    As human factors and ergonomics (HF/E) moves to embrace a greater systems perspective concerning human-machine technologies, new and emergent properties, such as resilience, have arisen. Our objective here is to promote discussion as to how to measure this latter, complex phenomenon. Resilience is now a much-referenced goal for technology and work system design. It subsumes the new movement of resilience engineering. As part of a broader systems approach to HF/E, this concept requires both a definitive specification and an associated measurement methodology. Such an effort epitomizes our present work. Using rational analytic and synthetic methods, we offer an approach to the measurement of resilience capacity. We explicate how our proposed approach can be employed to compare resilience across multiple systems and domains, and emphasize avenues for its future development and validation. Emerging concerns for the promise and potential of resilience and associated concepts, such as adaptability, are highlighted. Arguments skeptical of these emerging dimensions must be met with quantitative answers; we advance one approach here. Robust and validated measures of resilience will enable coherent and rational discussions of complex emergent properties in macrocognitive system science.

  2. Measuring Up

    ERIC Educational Resources Information Center

    Hart, Holly; Healey, Kaleen; Sporte, Susan E.

    2014-01-01

    Moving teacher evaluation systems from measuring teachers' performance to improving their practice requires much greater attention to communication and support. In the fall of 2012, Chicago Public Schools (CPS) instituted a sweeping reform of its teacher evaluation system with the introduction of REACH Students (Recognizing Educators Advancing…

  3. March Measurements

    ERIC Educational Resources Information Center

    Riddle, Bob

    2010-01-01

    While science is certainly language based, it is also bilingual in the sense that mathematics is also "spoken" in science classes. There are many opportunities throughout the school year to integrate the language of mathematics with science lessons and activities. This month's column provides some measurement activities that can be incorporated…

  4. Measuring Height.

    ERIC Educational Resources Information Center

    Schoettle, Kenneth

    1982-01-01

    A school building was originally used while investigating the acceleration of a free-falling body due to gravity. Because it was difficult to measure time accurately over such a short distance, an alternative method using a rocket was used. Materials needed and a description of the activity are provided. (Author/JN)

  5. Measured Success

    ERIC Educational Resources Information Center

    Keating, Tom

    2009-01-01

    Many students think custodians are hired to pick up after them. And sometimes adult workers voice similarly negative impressions. What can education institutions do about this negative and improper thinking? Because of heightened concerns about invisible pathogens such as MRSA and swine flu, improved technologies are available to measure bacteria…

  6. Property Measurement

    NASA Astrophysics Data System (ADS)

    1980-01-01

    Van is used by Land Inventory Systems to measure and map property for tax assessment purposes. It is adapted from navigation system of the Lunar Rover wheeled vehicle in which moon-exploring astronauts traveled as much as 20 miles from their Lunar Module base. Astronauts had to know their precise position so that in case of emergency they could take the shortest route back. Computerized navigational system kept a highly accurate record of the directional path providing continuous position report. Distance measuring subsystem was a more accurate counterpart of automobile odometer system counts revolutions of wheels and encoders generate electrical pulses for each fractional revolution and the computer analyzed the pulses to determine the distance traveled in a given direction.

  7. Property Measurement

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Van is used by Land Inventory Systems to measure and map property for tax assessment purposes. It is adapted from navigation system of the Lunar Rover wheeled vehicle in which moon-exploring astronauts traveled as much as 20 miles from their Lunar Module base. Astronauts had to know their precise position so that in case of emergency they could take the shortest route back. Computerized navigational system kept a highly accurate record of the directional path providing continuous position report. Distance measuring subsystem was a more accurate counterpart of automobile odometer system counts revolutions of wheels and encoders generate electrical pulses for each fractional revolution and the computer analyzed the pulses to determine the distance traveled in a given direction.

  8. Stratospheric Measurements

    DTIC Science & Technology

    1978-04-01

    crystallized , presumably f mm operation at high pressure. Repeated operations also caused the pumping eurfaces of the mass filter chamber to overheat...top of the gondola. No internal damage was discernible although the alum - inum frame was slightly deformed. At the time it appeared that the gondola...in the Vac Ion output, which had been calibrated to measure vacuum chamber pressure. Shortly thereafter, growing noise was ob- served, followed by

  9. Measurement of \

    SciTech Connect

    Aguilar-Arevalo, A.A.; Anderson, C.E.; Bazarko, A.O.; Brice, S.J.; Brown, B.C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J.M.; Cox, D.C.; Curioni, A.; /Yale U. /Columbia U.

    2009-11-01

    MiniBooNE reports the first absolute cross sections for neutral current single {pi}{sup 0} production on CH{sub 2} induced by neutrino and antineutrino interactions measured from the largest sets of NC {pi}{sup 0} events collected to date. The principal result consists of differential cross sections measured as functions of {pi}{sup 0} momentum and {pi}{sup 0} angle averaged over the neutrino flux at MiniBooNE. We find total cross sections of (4.76 {+-} 0.05{sub stat} {+-} 0.40{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at a mean energy of = 808 MeV and (1.48 {+-} 0.05{sub stat} {+-} 0.14{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at a mean energy of = 664 MeV for {nu}{sub {mu}} and {bar {nu}}{sub {mu}} induced production, respectively. In addition, we have included measurements of the neutrino and antineutrino total cross sections for incoherent exclusive NC 1{pi}{sup 0} production corrected for the effects of final state interactions to compare to prior results.

  10. Measuring consensus

    SciTech Connect

    Kurstedt, H.A. Jr.; Brubaker, D.M.; Doss, A.R.; Koelling, C.P.

    1989-10-01

    For this paper, I wanted to compare mathematical techniques against group interaction in generating consensus for a ranking decision. I convened a group to come to consensus on ranking items needed for survival on the moon. I chose this problem because NASA has an approved solution. I solicited the group's individual rankings before and after discussion. I used Kendall's coefficient of concordance to measure the level of consensus before and after discussion and compared the results against individual qualitative responses to a questionnaire designed to also measure consensus. The approved solution allowed me to see if group felt more or less in agreement as they moved closer or farther from the approved solution. As background for this experiment, I researched the existing knowledge on measuring consensus. I make a distinction between consensus and successful consensus, define them, and operationalize them for the purposes of this study. I define different levels of consensus which can be reached regardless of the success of the consensus. In this experiment, I determined the interactive discussion produced consensus, but not successful consensus. The mathematical technique produced a ranking closer to the accepted answer than the group discussion did. 15 refs., 1 tab.

  11. Measuring Fractality

    PubMed Central

    Stadnitski, Tatjana

    2012-01-01

    When investigating fractal phenomena, the following questions are fundamental for the applied researcher: (1) What are essential statistical properties of 1/f noise? (2) Which estimators are available for measuring fractality? (3) Which measurement instruments are appropriate and how are they applied? The purpose of this article is to give clear and comprehensible answers to these questions. First, theoretical characteristics of a fractal pattern (self-similarity, long memory, power law) and the related fractal parameters (the Hurst coefficient, the scaling exponent α, the fractional differencing parameter d of the autoregressive fractionally integrated moving average methodology, the power exponent β of the spectral analysis) are discussed. Then, estimators of fractal parameters from different software packages commonly used by applied researchers (R, SAS, SPSS) are introduced and evaluated. Advantages, disadvantages, and constrains of the popular estimators (d^ML, power spectral density, detrended fluctuation analysis, signal summation conversion) are illustrated by elaborate examples. Finally, crucial steps of fractal analysis (plotting time series data, autocorrelation, and spectral functions; performing stationarity tests; choosing an adequate estimator; estimating fractal parameters; distinguishing fractal processes from short-memory patterns) are demonstrated with empirical time series. PMID:22586408

  12. Measuring fractality.

    PubMed

    Stadnitski, Tatjana

    2012-01-01

    WHEN INVESTIGATING FRACTAL PHENOMENA, THE FOLLOWING QUESTIONS ARE FUNDAMENTAL FOR THE APPLIED RESEARCHER: (1) What are essential statistical properties of 1/f noise? (2) Which estimators are available for measuring fractality? (3) Which measurement instruments are appropriate and how are they applied? The purpose of this article is to give clear and comprehensible answers to these questions. First, theoretical characteristics of a fractal pattern (self-similarity, long memory, power law) and the related fractal parameters (the Hurst coefficient, the scaling exponent α, the fractional differencing parameter d of the autoregressive fractionally integrated moving average methodology, the power exponent β of the spectral analysis) are discussed. Then, estimators of fractal parameters from different software packages commonly used by applied researchers (R, SAS, SPSS) are introduced and evaluated. Advantages, disadvantages, and constrains of the popular estimators ([Formula: see text] power spectral density, detrended fluctuation analysis, signal summation conversion) are illustrated by elaborate examples. Finally, crucial steps of fractal analysis (plotting time series data, autocorrelation, and spectral functions; performing stationarity tests; choosing an adequate estimator; estimating fractal parameters; distinguishing fractal processes from short-memory patterns) are demonstrated with empirical time series.

  13. Optical properties and tunable laser action of Verneuil-grown single crystals of Al2O3:Ti3+

    NASA Astrophysics Data System (ADS)

    Moncorge, R.; Boulon, G.; Vivien, D.; Lejus, A. M.; Collongues, R.

    1988-06-01

    Using the Verneuil technique, the authors have grown large single crystals of Al2O3:Ti3+ having concentrations up to 0.15 percent. Laser action was observed in this material, tunable over the range 700-810 nm. Losses in the 800-nm region are less than 0.03/cm (below the detection limit in the measurements).

  14. Measuring Light

    NASA Image and Video Library

    2017-09-27

    On July 13, 2011, Don Perovich, of Cold Regions Research and Engineering Laboratory, measured the light that drives photosynthesis at the sixth sea ice station of the 2011 ICESCAPE mission. The ICESCAPE mission, or "Impacts of Climate on Ecosystems and Chemistry of the Arctic Pacific Environment," is a NASA shipborne investigation to study how changing conditions in the Arctic affect the ocean's chemistry and ecosystems. The bulk of the research took place in the Beaufort and Chukchi seas in summer 2010 and 2011. Credit: NASA/Kathryn Hansen NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  15. MEASURING APPARATUS

    DOEpatents

    Kohman, T.P.; Weissbourd, B.W.

    1959-02-17

    An ion chamber assembly is presented for measuring neutron emission of a relatively slow rate from a radioactive sample. The detecting apparatus comprises a container filled with neutron slowing material and having a cavity where a neutron source may be located centrally in the container. A plurality of ion chamber units are disposed equidistantly from the source and from each other for detecting the neutron radiation. Each of the ion chamber units has an ion chamber and a second chamber of substantially the same diameter as the ion chamber and in end-to-end relationship therewith. The second chamber contains paraffin and an axially disposed lead-in conductor for the ion chamber central electrode. The preamplifier circuit whose input is connected to the lead-in conductor is housed in a third container arranged in end-to-end relationship with the second chamber.

  16. Beta measurements

    NASA Technical Reports Server (NTRS)

    Schotland, R. M.; Warren, A. J.; Funariu, O. M.

    1991-01-01

    The second year's results of the BETA project research are presented. The program is divided into two areas, aerosol modification and climatology in the trade wind region and the climatology of BETA (CO2) on remote mountain top locations. Limited data is available on the aerosol climatology of the marine free troposphere (MFT) in the trade wind region. In order to study the effects of cumulus convection on the MFT values of BETA, a cloud model was developed to simulate the evolution of a typical Pacific trade wind cumulus cloud. The stages involved in this development are outlined. The assembly of the major optical components of the lidar was made. Tests were run of the spectral bandwidth of the Synrad laser when a portion of the beam is mixed with a component which has traveled 450 meters corresponding to a delay of 1.5 microsecs. The bandwidth of the beat signal was measured to be 3 KHz. The data processing system based on a parallel processing filter bank analyzer using true time squaring detectors at each filter was completed.

  17. Multipulse interferometric frequency-resolved optical gating

    SciTech Connect

    Siders, C.W.; Siders, J.L.W.; Omenetto, F.G.; Taylor, A.J.

    1999-04-01

    The authors review multipulse interferometric frequency-resolved optical gating (MI-FROG) as a technique, uniquely suited for pump-probe coherent spectroscopy using amplified visible and near-infrared short-pulse systems and/or emissive targets, for time-resolving ultrafast phase shifts and intensity changes. Application of polarization-gate MI-FROG to the study of ultrafast ionization in gases is presented.

  18. System of measurement of the transmission spectrum of in-vitro corneas for eye banks

    NASA Astrophysics Data System (ADS)

    de Meneses Bispo, Josemilson; Ventura, Liliane; de Carvalho, Carlos R., Jr.; de Sousa, Sidney J. F.; Chiaradia, Caio

    1998-05-01

    The donated cornea transparency is one of the features to be analyzed previously to its indication for the transplant. Hence we have developed a system to evaluate the transmission spectrum of 'In Vitro' corneas in its preservative medium, in the range of 400 - 700 nm, to be implemented in an Eye Bank. The cornea in its preservative medium is illuminated by collimated white light beams which strike a diffraction grid, passes through an optical system and a selecting filter (400 - 800 nm) and then is detected by a linear CCD detector (2048 photodiodes). The data is displayed in a PC monitor via a commercial interface device. A dedicated software has been developed to plot the transmission spectrum profile and provide an objective and standard information about the transparency of the donated cornea.

  19. Intervalley separation in the conduction band of InGaAs measured by terahertz excitation spectroscopy

    SciTech Connect

    Molis, G.; Krotkus, A.; Vaicaitis, V.

    2009-03-02

    Spectral dependencies of terahertz radiation from the femtosecond laser-illuminated surfaces of Ga{sub x}In{sub 1-x}As (x=1, 0.8, and 0.47) have been investigated experimentally at high optical fluencies and laser wavelengths ranging from 600 to 800 nm. The terahertz pulse amplitude increased with the increasing laser photon energy due to larger excess energies of photoexcited electrons and more efficient spatial separation of electrons and holes at the illuminated surface. This increase was stopped with the onset of electron transitions to subsidiary conduction band valleys. Analysis of these experiments was used for evaluating the energy positions of the X and L conduction band valleys in Ga{sub x}In{sub 1-x}As alloys as a function of their composition.

  20. Man Is the Measure...the Measurer.

    ERIC Educational Resources Information Center

    Stone, Mark H.

    1998-01-01

    The science of metrology has moved from man as the measure to man as the measurer. This transformation is documented with examples from the history of metrology. Outcome measures, which rest on the same history of measurement, are units constructed and maintained for their utility, constancy, and generality. (Author/SLD)

  1. Man Is the Measure...the Measurer.

    ERIC Educational Resources Information Center

    Stone, Mark H.

    1998-01-01

    The science of metrology has moved from man as the measure to man as the measurer. This transformation is documented with examples from the history of metrology. Outcome measures, which rest on the same history of measurement, are units constructed and maintained for their utility, constancy, and generality. (Author/SLD)

  2. Work measurement as a generalized quantum measurement.

    PubMed

    Roncaglia, Augusto J; Cerisola, Federico; Paz, Juan Pablo

    2014-12-19

    We present a new method to measure the work w performed on a driven quantum system and to sample its probability distribution P(w). The method is based on a simple fact that remained unnoticed until now: Work on a quantum system can be measured by performing a generalized quantum measurement at a single time. Such measurement, which technically speaking is denoted as a positive operator valued measure reduces to an ordinary projective measurement on an enlarged system. This observation not only demystifies work measurement but also suggests a new quantum algorithm to efficiently sample the distribution P(w). This can be used, in combination with fluctuation theorems, to estimate free energies of quantum states on a quantum computer.

  3. Work Measurement as a Generalized Quantum Measurement

    NASA Astrophysics Data System (ADS)

    Roncaglia, Augusto J.; Cerisola, Federico; Paz, Juan Pablo

    2014-12-01

    We present a new method to measure the work w performed on a driven quantum system and to sample its probability distribution P (w ). The method is based on a simple fact that remained unnoticed until now: Work on a quantum system can be measured by performing a generalized quantum measurement at a single time. Such measurement, which technically speaking is denoted as a positive operator valued measure reduces to an ordinary projective measurement on an enlarged system. This observation not only demystifies work measurement but also suggests a new quantum algorithm to efficiently sample the distribution P (w ). This can be used, in combination with fluctuation theorems, to estimate free energies of quantum states on a quantum computer.

  4. Measurement technology: A compilation

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Technical information is presented on measurement techniques and instruments, measurement applications for inspection activities, measurement sensors, and data conversion methods. Photographs or diagrams are included for each instrument or method described, and where applicable, patent information is given.

  5. Measuring Test Measurement Error: A General Approach

    ERIC Educational Resources Information Center

    Boyd, Donald; Lankford, Hamilton; Loeb, Susanna; Wyckoff, James

    2013-01-01

    Test-based accountability as well as value-added asessments and much experimental and quasi-experimental research in education rely on achievement tests to measure student skills and knowledge. Yet, we know little regarding fundamental properties of these tests, an important example being the extent of measurement error and its implications for…

  6. Measuring Test Measurement Error: A General Approach

    ERIC Educational Resources Information Center

    Boyd, Donald; Lankford, Hamilton; Loeb, Susanna; Wyckoff, James

    2013-01-01

    Test-based accountability as well as value-added asessments and much experimental and quasi-experimental research in education rely on achievement tests to measure student skills and knowledge. Yet, we know little regarding fundamental properties of these tests, an important example being the extent of measurement error and its implications for…

  7. Surface-plasmon enhanced ultrafast third-order optical nonlinearities in ellipsoidal gold nanoparticles embedded bismuthate glasses

    NASA Astrophysics Data System (ADS)

    Chen, Feifei; Dai, Shixun; Xu, Tiefeng; Shen, Xiang; Lin, Changgui; Nie, Qiuhua; Liu, Chao; Heo, Jong

    2011-09-01

    Ellipsoidal gold nanoparticles embedded bismuthate glasses have been prepared via a facile melt-annealing approach. Femtosecond Z-scan measurement shows that the nanocomposites exhibit a maximum third-order nonlinear susceptibility χ(3) of 4.88 × 10-10 esu at 800 nm, which is two orders higher than that of the host glass. Optical Kerr shutter measurement demonstrates ultrafast response time (in scale of sub-picosecond) of the intraband transition enhanced third-order nonlinearities.

  8. Spectrophotometric determination of oxygen saturation of blood independent of the presence of indocyanine green.

    PubMed

    Mook, G A; Buursma, A; Gerding, A; Kwant, G; Zijlstra, W G

    1979-04-01

    The strong absorbance of indocyanine green in a broad band around lambda = 800 nm invalidates the usual spectrophotometric two-wavelength methods for measuring oxygen saturation operating in the red and near infrared region. By proper wavelength selection, however, the effect of the dye can be eliminated. With the two-wavelength method utilising lambda = 660 and 860 nm oxygen saturation is measured virtually independent of the presence of indocyanine green.

  9. Measuring the Internet.

    ERIC Educational Resources Information Center

    Molyneux, Robert E.; Williams, Robert V.

    1999-01-01

    Examines the literature that measures characteristics of the Internet. Discusses: conclusions about the Internet measurement literature; definition of the Internet from a technical standpoint; history of Internet measurement; nature of the Internet data environment; Internet technical characteristics; information measurement and the Internet;…

  10. Software measurement guidebook

    NASA Technical Reports Server (NTRS)

    Bassman, Mitchell J.; Mcgarry, Frank; Pajerski, Rose

    1994-01-01

    This software Measurement Guidebook presents information on the purpose and importance of measurement. It discusses the specific procedures and activities of a measurement program and the roles of the people involved. The guidebook also clarifies the roles that measurement can and must play in the goal of continual, sustained improvement for all software production and maintenance efforts.

  11. Measuring the Internet.

    ERIC Educational Resources Information Center

    Molyneux, Robert E.; Williams, Robert V.

    1999-01-01

    Examines the literature that measures characteristics of the Internet. Discusses: conclusions about the Internet measurement literature; definition of the Internet from a technical standpoint; history of Internet measurement; nature of the Internet data environment; Internet technical characteristics; information measurement and the Internet;…

  12. Measuring Small Leak Holes

    NASA Technical Reports Server (NTRS)

    Koch, D. E.; Stephenson, J. G.

    1983-01-01

    Hole sizes deduced from pressure measurements. Measuring apparatus consists of pitot tube attached to water-filled manometer. Compartment tested is pressurized with air. Pitot probe placed at known distance from leak. Dynamic pressure of jet measured at that point and static pressure measured in compartment. Useful in situations in which small leaks are tolerable but large leaks are not.

  13. Can Virtue Be Measured?

    ERIC Educational Resources Information Center

    Curren, Randall; Kotzee, Ben

    2014-01-01

    This article explores some general considerations bearing on the question of whether virtue can be measured. What is moral virtue? What are measurement and evaluation, and what do they presuppose about the nature of what is measured or evaluated? What are the prospective contexts of, and purposes for, measuring or evaluating virtue, and how would…

  14. Can Virtue Be Measured?

    ERIC Educational Resources Information Center

    Curren, Randall; Kotzee, Ben

    2014-01-01

    This article explores some general considerations bearing on the question of whether virtue can be measured. What is moral virtue? What are measurement and evaluation, and what do they presuppose about the nature of what is measured or evaluated? What are the prospective contexts of, and purposes for, measuring or evaluating virtue, and how would…

  15. Measurement of Evidence and Evidence of Measurement

    PubMed Central

    Vieland, Veronica J; Hodge, Susan E

    2011-01-01

    One important use of statistical methods in application to biological data is measurement of evidence, or assessment of the degree to which data support one or another hypothesis. While there is a small literature on this topic, it seems safe to say that consensus has not yet been reached regarding how best, or most accurately, to measure statistical evidence. Here, we propose considering the problem as a measurement problem, rather than as a statistical problem per se, and we explore the consequences of this shift in perspective. Our arguments here are part of an ongoing research program focused on exploiting deep parallelisms between foundations of thermodynamics and foundations of “evidentialism,” in order to derive an absolute scale for the measurement of evidence, a general framework in the context of which that scale is validated, and the many ancillary benefits that come from having such a framework in place.

  16. Temperature Measurements in the Magnetic Measurement Facility

    SciTech Connect

    Wolf, Zachary

    2010-12-13

    Several key LCLS undulator parameter values depend strongly on temperature primarily because of the permanent magnet material the undulators are constructed with. The undulators will be tuned to have specific parameter values in the Magnetic Measurement Facility (MMF). Consequently, it is necessary for the temperature of the MMF to remain fairly constant. Requirements on undulator temperature have been established. When in use, the undulator temperature will be in the range 20.0 {+-} 0.2 C. In the MMF, the undulator tuning will be done at 20.0 {+-} 0.1 C. For special studies, the MMF temperature set point can be changed to a value between 18 C and 23 C with stability of {+-}0.1 C. In order to ensure that the MMF temperature requirements are met, the MMF must have a system to measure temperatures. The accuracy of the MMF temperature measurement system must be better than the {+-}0.1 C undulator tuning temperature tolerance, and is taken to be {+-}0.01 C. The temperature measurement system for the MMF is under construction. It is similar to a prototype system we built two years ago in the Sector 10 alignment lab at SLAC. At that time, our goal was to measure the lab temperature to {+-}0.1 C. The system has worked well for two years and has maintained its accuracy. For the MMF system, we propose better sensors and a more extensive calibration program to achieve the factor of 10 increase in accuracy. In this note we describe the measurement system under construction. We motivate our choice of system components and give an overview of the system. Most of the software for the system has been written and will be discussed. We discuss error sources in temperature measurements and show how these errors have been dealt with. The calibration system is described in detail. All the LCLS undulators must be tuned in the Magnetic Measurement Facility at the same temperature to within {+-}0.1 C. In order to ensure this, we are building a system to measure the temperature of the

  17. Metrology measurement capabilities

    SciTech Connect

    Shroyer, K.

    1997-02-01

    Since 1958, the AlliedSignal Federal Manufacturing and Technologies (FM and T) Metrology Department has developed measurement technology and calibration capability in four major areas of measurement: (1) mechanical; (2) environmental, gas, liquid; (3) electrical (D.C., A.C., RF/Microwave); and (4) optical and radiation. The capabilities developed include unique capabilities in many areas of measurement and engineering expertise to develop measurement techniques and resolve measurement problems in these major areas. A strong audit function has been developed to provide a means to evaluate the calibration programs of the suppliers and internal calibration organizations. This evaluation includes measurement audits and technical surveys. The requirements placed on metrology require traceability of measurements to the National Institute of Standards and Technology or to nationally recognized methods or natural phenomena. A description of Metrology capabilities, traceability flow charts, and the measurement uncertainty of each of the measurement capabilities is contained in the report.

  18. Spectral characteristics of Shuttle glow

    NASA Technical Reports Server (NTRS)

    Viereck, R. A.; Mende, S. B.; Murad, E.; Swenson, G. R.; Pike, C. P.; Culbertson, F. L.; Springer, R. C.

    1992-01-01

    The glowing cloud near the ram surfaces of the Space Shuttle was observed with a hand-held, intensified spectrograph operated by the astronauts from the aft-flight-deck of the Space Shuttle. The spectral measurements were made between 400 and 800 nm with a resolution of 3 nm. Analysis of the spectral response of the instrument and the transmission of the Shuttle window was performed on orbit using earth-airglow OH Meinel bands. This analysis resulted in a correction of the Shuttle glow intensity in the spectral region between 700 and 800 nm. The data presented in this report is in better agreement with laboratory measurements of the NO2 continuum.

  19. Quality measurement in healthcare.

    PubMed

    Lazar, Eliot J; Fleischut, Peter; Regan, Brian K

    2013-01-01

    Measurement is the basis for assessing potential improvements in healthcare quality. Measures may be classified into four categories: volume, structure, outcome, and process (VSOP). Measures of each type should be used with a full understanding of their cost and benefit. Although volume and structure measures are easily collected, impact on healthcare results is not always clear. Process measures are generally more difficult and expensive to collect, and the relationship between process and outcomes is only recently being explored. Knowledge of measure types and relationships among them, as well as emerging evidence on the role of patient satisfaction, must be used to guide improvements and ultimately for demonstrating value in healthcare.

  20. Metrology measurement capability

    NASA Astrophysics Data System (ADS)

    Shroyer, K.

    1995-01-01

    During the past 36 years, the Kansas City Division's (KCD) Metrology Department has developed measurement technology and calibration capability in four major areas of measurement: (1) Mechanical; (2) Environmental, Gas, Liquid; Electrical (D.C., A.C., RF/Microwave); and (3) Optical and Radiation. The capabilities developed include unique capabilities in many areas of measurement and engineering expertise to develop measurement techniques and resolve measurement problems in these major areas. KCD Metrology was established in 1958 to provide a measurement base for the Kansas City Plant. The Metrology Engineering Department provides the expertise to develop measurement capabilities for virtually any type of measurement which falls into the broad areas listed above. The engineering staff currently averages almost 19 years of measurement experience. A strong audit function has been developed to provide a means to evaluate the calibration programs of our suppliers and internal calibration organizations. This evaluation includes measurement audits and technical surveys. The requirements placed on Metrology require traceability of measurements to the National Institute of Standards and Technology or to nationally recognized methods or natural phenomena. A description of Metrology capabilities, traceability flow charts, and the measurement uncertainty of each of the measurement capabilities is contained in the following pages.

  1. Metrology measurement capabilities

    SciTech Connect

    Barnes, L.M.

    1997-06-01

    Since 1958, the AlliedSignal Federal Manufacturing and Technologies (FM and T) Metrology Department has developed measurement technology and calibration capability in four major areas of measurement: mechanical; environmental, gas, liquid; electrical (D.C., A.C., RF/microwave); and optical and radiation. The capabilities developed include unique capabilities in many areas of measurement and engineering expertise to develop measurement techniques and resolve measurement problems in these major areas. FM and T Metrology was established in 1958 to provide a measurement base for the Department of energy`s Kansas City Plant. The Metrology Engineering Department provides the expertise to develop measurement capabilities for virtually any type of measurement which falls into the broad areas listed above. The engineering staff currently averages almost 16 years of measurement experience. A strong audit function has been developed to provide a means to evaluate the calibration programs of the suppliers and internal calibration organizations. This evaluation includes measurement audits and technical surveys. The requirements placed on Metrology require traceability of measurements to the National Institute of Standards and Technology or to nationally recognized methods or natural phenomena. A description of Metrology capabilities, traceability flow charts, and the measurement uncertainty of each of the measurement capabilities is contained in this report.

  2. Metrology measurement capability

    SciTech Connect

    Shroyer, K.

    1995-01-01

    During the past 36 years, the Kansas City Division`s (KCD) Metrology Department has developed measurement technology and calibration capability in four major areas of measurement: (1) Mechanical; (2) Environmental, Gas, Liquid; Electrical (D.C., A.C., RF/Microwave); and (3) Optical and Radiation. The capabilities developed include unique capabilities in many areas of measurement and engineering expertise to develop measurement techniques and resolve measurement problems in these major areas. KCD Metrology was established in 1958 to provide a measurement base for the Kansas City Plant. The Metrology Engineering Department provides the expertise to develop measurement capabilities for virtually any type of measurement which falls into the broad areas listed above. The engineering staff currently averages almost 19 years of measurement experience. A strong audit function has been developed to provide a means to evaluate the calibration programs of our suppliers and internal calibration organizations. This evaluation includes measurement audits and technical surveys. The requirements placed on Metrology require traceability of measurements to the National Institute of Standards and Technology or to nationally recognized methods or natural phenomena. A description of Metrology capabilities, traceability flow charts, and the measurement uncertainty of each of the measurement capabilities is contained in the following pages.

  3. Electrolyte measurement device and measurement procedure

    DOEpatents

    Cooper, Kevin R.; Scribner, Louie L.

    2010-01-26

    A method and apparatus for measuring the through-thickness resistance or conductance of a thin electrolyte is provided. The method and apparatus includes positioning a first source electrode on a first side of an electrolyte to be tested, positioning a second source electrode on a second side of the electrolyte, positioning a first sense electrode on the second side of the electrolyte, and positioning a second sense electrode on the first side of the electrolyte. current is then passed between the first and second source electrodes and the voltage between the first and second sense electrodes is measured.

  4. MEaSUREs

    Atmospheric Science Data Center

    2013-06-26

    ... MEaSUREs ( Making Earth Science Data Records for Use in Research Environments ) supports the NASA Earth Science ... to expand understanding the Earth system using consistent records. Details:  MEaSUREs Screenshot:  ...

  5. Emissions & Measurements - Black Carbon

    EPA Science Inventory

    Emissions and Measurement (EM) research activities performed within the National Risk Management Research Lab NRMRL) of EPA's Office of Research and Development (ORD) support measurement and laboratory analysis approaches to accurately characterize source emissions, and near sour...

  6. Emissions & Measurements - Black Carbon

    EPA Science Inventory

    Emissions and Measurement (EM) research activities performed within the National Risk Management Research Lab NRMRL) of EPA's Office of Research and Development (ORD) support measurement and laboratory analysis approaches to accurately characterize source emissions, and near sour...

  7. Ozone Correlative Measurements Workshop

    NASA Technical Reports Server (NTRS)

    Hilsenrath, E. (Editor)

    1985-01-01

    A study was conducted to determine the necessary parameters for the correlation of data on Earth ozone. Topics considered were: (1) measurement accuracy; (2) equipment considerations (SBUV); and (3) ground based measurements to support satellite data.

  8. Implementing Safety Measures

    EPA Pesticide Factsheets

    Required risk mitigation measures for soil fumigants protect handlers, applicators, and bystanders from pesticide exposure. Measures include buffer zones, sign posting, good agricultural practices, restricted use pesticide classification, and FMPs.

  9. AEROSOL AND GAS MEASUREMENT

    EPA Science Inventory

    Measurements provide fundamental information for evaluating and managing the impact of aerosols on air quality. Specific measurements of aerosol concentration and their physical and chemical properties are required by different users to meet different user-community needs. Befo...

  10. Downhole steam quality measurement

    DOEpatents

    Lee, David O.; Montoya, Paul C.; Muir, James F.; Wayland, Jr., J. Robert

    1987-01-01

    An empirical method for the remote sensing of steam quality that can be easily adapted to downhole steam quality measurements by measuring the electrical properties of two-phase flow across electrode grids at low frequencies.

  11. AEROSOL AND GAS MEASUREMENT

    EPA Science Inventory

    Measurements provide fundamental information for evaluating and managing the impact of aerosols on air quality. Specific measurements of aerosol concentration and their physical and chemical properties are required by different users to meet different user-community needs. Befo...

  12. Developing Effective Performance Measures

    DTIC Science & Technology

    2014-10-14

    University When Performance Measurement Goes Bad Laziness Vanity Narcissism Too Many Pettiness Inanity 52 Developing Effective...Kasunic, October 14, 2014 © 2014 Carnegie Mellon University Narcissism Measuring performance from the organization’s point of view, rather than from

  13. Force-Measuring Clamp

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark (Inventor)

    2004-01-01

    A precision clamp that accurately measures force over a wide range of conditions is described. Using a full bridge or other strain gage configuration. the elastic deformation of the clamp is measured or detected by the strain gages. Thc strain gages transmit a signal that corresponds to the degree of stress upon the clamp. Thc strain gage signal is converted to a numeric display. Calibration is achieved by ero and span potentiometers which enable accurate measurements by the force-measuring clamp.

  14. Supply Chain Interoperability Measurement

    DTIC Science & Technology

    2015-06-19

    linkages and impact on business performance. Omega 3 : 153- 62. Kaplan , R., and D. Norton . 1992. The balanced scorecard - measures that drive...performance. Harvard Business Review 70 (1): 71. Kaplan S.R., and Norton P.D. 2001. Transforming the balanced scorecard from performance measurement to...measures but the more recent academic research, following Eccles (1991) and Kaplan and Norton (1992), propose measurements with a multi-dimensional

  15. Frequency domain measurement systems

    NASA Technical Reports Server (NTRS)

    Eischer, M. C.

    1978-01-01

    Stable frequency sources and signal processing blocks were characterized by their noise spectra, both discrete and random, in the frequency domain. Conventional measures are outlined, and systems for performing the measurements are described. Broad coverage of system configurations which were found useful is given. Their functioning and areas of application are discussed briefly. Particular attention is given to some of the potential error sources in the measurement procedures, system configurations, double-balanced-mixer-phase-detectors, and application of measuring instruments.

  16. Impedance Measurement Box

    SciTech Connect

    Morrison, William

    2014-11-20

    The IMB 50V software provides functionality for design of impedance measurement tests or sequences of tests, execution of these tests or sequences, processing measured responses and displaying and saving of the results. The software consists of a Graphical User Interface that allows configuration of measurement parameters and test sequencing, a core engine that controls test sequencing, execution of measurements, processing and storage of results and a hardware/software data acquisition interface with the IMB hardware system.

  17. Radar Cross Section Measurements

    DTIC Science & Technology

    1986-09-30

    Radar 54 17. Measured Range Sidelobe Performance of Chirp Radar 56 18. Range and Cross Range Image of Target Dror.’ŕ Vehicle 57 19. Incoherent rms...the measured range resolution, 4.9 in, closely agrees with the theoretical performance for this weighting. The measured range sidelobe performance...Interval 4.89in. 2% kHz 300 kHz 310 kHz (b) Expanded Scale + 5 ft from Target Figure 17. Measured Range Sidelobe Performance of

  18. Force-Measuring Clamp

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark (Inventor)

    2004-01-01

    A precision clamp that accurately measures force over a wide range of conditions is described. Using a full bridge or other strain gage configuration. the elastic deformation of the clamp is measured or detected by the strain gages. Thc strain gages transmit a signal that corresponds to the degree of stress upon the clamp. Thc strain gage signal is converted to a numeric display. Calibration is achieved by ero and span potentiometers which enable accurate measurements by the force-measuring clamp.

  19. Measurement and Research Tools.

    ERIC Educational Resources Information Center

    1997

    This document contains four papers from a symposium on measurement and research tools for human resource development (HRD). "The 'Best Fit' Training: Measure Employee Learning Style Strengths" (Daniel L. Parry) discusses a study of the physiological aspect of sensory intake known as modality, more specifically, modality as measured by…

  20. A Magnetoresistance Measuring Probe.

    DTIC Science & Technology

    The in line four point probe, commonly used for measuring the sheet resistance in a conductor, cannot measure the anisotropic ferromagnetic magnetoresistance. However, the addition of two contact points that are not collinear with the current contacts give the probe the ability to non-destructively measure the anistropic magnetoresistance. Keywords: Magnetoresistance; Anisotropic; Thin-Film; Permalloy; Four Point Probe; Anisotropic Resistance.

  1. Measurement Practice Guide

    ERIC Educational Resources Information Center

    College and Career Readiness and Success Center, 2014

    2014-01-01

    This discussion guide is part of a larger practice guide designed to help state education agencies (SEAs) define measurement goals, select college and career readiness measures and indicators designed to support those goals, and use the data gathered with those measures and indicators to make informed decisions about college and career readiness…

  2. Coordinate measuring system

    DOEpatents

    Carlisle, Keith

    2003-04-08

    An apparatus and method is utilized to measure relative rigid body motion between two bodies by measuring linear motion in the principal axis and linear motion in an orthogonal axis. From such measurements it is possible to obtain displacement, departure from straightness, and angular displacement from the principal axis of a rigid body.

  3. Measuring the Immeasurable

    ERIC Educational Resources Information Center

    Downs, Sylvia

    2004-01-01

    There is growing evidence of the wider benefits of learning on non-accredited courses. However, there appears to be a problem on how these benefits can be measured. The Learning and Skills Council consultation "Measuring Success in the Learning and Skills Sector" (2003) confirms that no national measures exist for recognising achievements in…

  4. Teaching Measurement with Literature

    ERIC Educational Resources Information Center

    Bintz, William P.; Moore, Sara D.

    2011-01-01

    Measurement is a difficult concept for many children. Trend data from the National Association of Educational Progress (NAEP) indicate that student achievement with measurement is disappointing, given the amount of instructional time it receives in K-grade 5. In an attempt to address the problem of student achievement with measurement, the authors…

  5. Command Wire Sensor Measurements

    DTIC Science & Technology

    2012-09-01

    In addition , the measurement results have also demonstrated close-in clutter rejection by utilizing time gating. Recommendations for future work...measurement results. In addition , the measurement results have also demonstrated close-in clutter rejection by utilizing time gating. Recommendations...of low frequency tradeoffs (From [7]) ............................................18  Table 2.  Summary of high frequency tradeoffs (From [7

  6. Measurement and Research Tools.

    ERIC Educational Resources Information Center

    1997

    This document contains four papers from a symposium on measurement and research tools for human resource development (HRD). "The 'Best Fit' Training: Measure Employee Learning Style Strengths" (Daniel L. Parry) discusses a study of the physiological aspect of sensory intake known as modality, more specifically, modality as measured by…

  7. Standards for holdup measurement

    SciTech Connect

    Zucker, M.S.

    1982-01-01

    Holdup measurement, needed for material balance, depend intensively on standards and on interpretation of the calibration procedure. More than other measurements, the calibration procedure using the standard becomes part of the standard. Standards practical for field use and calibration techniques have been developed. While accuracy in holdup measurements is comparatively poor, avoidance of bias is a necessary goal.

  8. Measuring Rural Hospital Quality

    ERIC Educational Resources Information Center

    Moscovice, Ira; Wholey, Douglas R.; Klingner, Jill; Knott, Astrid

    2004-01-01

    Increased interest in the measurement of hospital quality has been stimulated by accrediting bodies, purchaser coalitions, government agencies, and other entities. This paper examines quality measurement for hospitals in rural settings. We seek to identify rural hospital quality measures that reflect quality in all hospitals and that are sensitive…

  9. Measuring Rural Hospital Quality

    ERIC Educational Resources Information Center

    Moscovice, Ira; Wholey, Douglas R.; Klingner, Jill; Knott, Astrid

    2004-01-01

    Increased interest in the measurement of hospital quality has been stimulated by accrediting bodies, purchaser coalitions, government agencies, and other entities. This paper examines quality measurement for hospitals in rural settings. We seek to identify rural hospital quality measures that reflect quality in all hospitals and that are sensitive…

  10. GROUP VERSUS INDIVIDUAL MEASURES.

    ERIC Educational Resources Information Center

    TRISMEN, DONALD A.

    THE AUTHOR STATES THAT INFORMATION LOSS IN CURRICULUM EVALUATION IS RELATED TO THE ASSUMPTION THAT GROUP MEASURES AND AVERAGES OF INDIVIDUAL MEASURES ARE INTERCHANGEABLE IN YIELDING IDENTICAL INFORMATION. TYPES OF RELATIONSHIPS BETWEEN GROUP AND INDIVIDUAL MEASURES ARE LISTED. THE AUTHOR DISCUSSES ONE OF THESE TYPES OF RELATIONSHIPS, SPECIFICALLY,…

  11. Measuring Gearbox Torque Loss

    NASA Technical Reports Server (NTRS)

    Schmidt, L. F.

    1986-01-01

    Accuracy increased by measuring small torque differences directly. Input and output torques are balanced by mechanical linkage in transmission-testing apparatus. Force applied to load cell proportional to frictional torque loss in transmission. Apparatus measures portion of input torque lost to friction in automotive transmissions or other gearbox. Apparatus more sensitive than previous measuring systems.

  12. Essentials of Educational Measurement.

    ERIC Educational Resources Information Center

    Ebel, Robert L.

    This textbook is intended for use in an introductory course in the use of tests in schools and colleges. The book is divided into five parts: (1) history and philosophy--educational measurement, historical perspectives; Measurement and the process of education; (2) classroom test development--what should achievement tests measure?; How should…

  13. Teaching Measurement with Literature

    ERIC Educational Resources Information Center

    Bintz, William P.; Moore, Sara D.

    2011-01-01

    Measurement is a difficult concept for many children. Trend data from the National Association of Educational Progress (NAEP) indicate that student achievement with measurement is disappointing, given the amount of instructional time it receives in K-grade 5. In an attempt to address the problem of student achievement with measurement, the authors…

  14. MEASURABLE UTILITY AND THE MEASURABLE CHOICE THEOREM.

    DTIC Science & Technology

    Three theorems are proved that are useful in mathematical treatments of economic models with a continuum of economic agents . The first, called the...measurable. Both these theorems generalize known theorems on these subjects. The third theorem treats a situation in which the set of economic agents forms

  15. Two-optical-cycle pulses in the mid-infrared from an optical parametric amplifier.

    PubMed

    Brida, D; Marangoni, M; Manzoni, C; Silvestri, S De; Cerullo, G

    2008-12-15

    Ultrabroadband mid IR pulses with energy as high as 2 microJ and tunability from 2 to 5 microm are generated as the idler beam of an 800 nm pumped optical parametric amplifier in periodically poled stoichiometric lithium tantalate. After bulk compression in a Ge plate and frequency-resolved-opticle-gating characterization, a pulse duration as low as 25 fs was measured, corresponding to two optical cycles of the 3.6 microm carrier wavelength.

  16. Platinum nanostructures formed by femtosecond laser irradiation in water

    SciTech Connect

    Huo Haibin; Shen Mengyan

    2012-11-15

    Platinum nanostructures with various morphologies, such as spike-like, ripple-like and array-like structures, have been fabricated by 400 nm and 800 nm femtosecond laser irradiation in water. Different structures can be formed on the surfaces as a function of the laser wavelength, the fluence and scan methods. The reflectance measurements of these structures show much larger absorption on the irradiated surfaces than untreated platinum surfaces.

  17. Ultra low emittance electron beams from multi-alkali antimonide photocathode operated with infrared light

    NASA Astrophysics Data System (ADS)

    Cultrera, L.; Gulliford, C.; Bartnik, A.; Lee, H.; Bazarov, I.

    2016-03-01

    The intrinsic emittance of electron beams generated from a multi-alkali photocathode operated in a high voltage DC gun is reported. The photocathode showed sensitivity extending to the infrared part of the spectrum up to 830 nm. The measured intrinsic emittances of electron beams generated with light having wavelength longer than 800 nm are approaching the limit imposed by the thermal energy of electrons at room temperature with quantum efficiencies comparable to metallic photocathodes used in operation of modern photoinjectors.

  18. Measuring Seebeck Coefficient

    NASA Technical Reports Server (NTRS)

    Snyder, G. Jeffrey (Inventor)

    2015-01-01

    A high temperature Seebeck coefficient measurement apparatus and method with various features to minimize typical sources of errors is described. Common sources of temperature and voltage measurement errors which may impact accurate measurement are identified and reduced. Applying the identified principles, a high temperature Seebeck measurement apparatus and method employing a uniaxial, four-point geometry is described to operate from room temperature up to 1300K. These techniques for non-destructive Seebeck coefficient measurements are simple to operate, and are suitable for bulk samples with a broad range of physical types and shapes.

  19. Measuring Nasal Obstruction.

    PubMed

    Keeler, Jarrod; Most, Sam P

    2016-08-01

    The nose and the nasal airway is highly complex with intricate 3-dimensional anatomy, with multiple functions in respiration and filtration of the respired air. Nasal airway obstruction (NAO) is a complex problem with no clearly defined "gold-standard" in measurement. There are 3 tools for the measurement of NAO: patient-derived measurements, physician-observed measurements, and objective measurements. We continue to work towards finding a link between subjective and objective nasal obstruction. The field of evaluation and surgical treatment for NAO has grown tremendously in the past 4-5 decades and will continue to grow as we learn more about the pathophysiology and treatment of nasal obstruction.

  20. Current measurement apparatus

    DOEpatents

    Umans, Stephen D.

    2008-11-11

    Apparatus and methods are provided for a system for measurement of a current in a conductor such that the conductor current may be momentarily directed to a current measurement element in order to maintain proper current without significantly increasing an amount of power dissipation attributable to the current measurement element or adding resistance to assist in current measurement. The apparatus and methods described herein are useful in superconducting circuits where it is necessary to monitor current carried by the superconducting elements while minimizing the effects of power dissipation attributable to the current measurement element.

  1. Precision electroweak measurements

    SciTech Connect

    Demarteau, M.

    1996-11-01

    Recent electroweak precision measurements fro {ital e}{sup +}{ital e}{sup -} and {ital p{anti p}} colliders are presented. Some emphasis is placed on the recent developments in the heavy flavor sector. The measurements are compared to predictions from the Standard Model of electroweak interactions. All results are found to be consistent with the Standard Model. The indirect constraint on the top quark mass from all measurements is in excellent agreement with the direct {ital m{sub t}} measurements. Using the world`s electroweak data in conjunction with the current measurement of the top quark mass, the constraints on the Higgs` mass are discussed.

  2. Consistent quantum measurements

    NASA Astrophysics Data System (ADS)

    Griffiths, Robert B.

    2015-11-01

    In response to recent criticisms by Okon and Sudarsky, various aspects of the consistent histories (CH) resolution of the quantum measurement problem(s) are discussed using a simple Stern-Gerlach device, and compared with the alternative approaches to the measurement problem provided by spontaneous localization (GRW), Bohmian mechanics, many worlds, and standard (textbook) quantum mechanics. Among these CH is unique in solving the second measurement problem: inferring from the measurement outcome a property of the measured system at a time before the measurement took place, as is done routinely by experimental physicists. The main respect in which CH differs from other quantum interpretations is in allowing multiple stochastic descriptions of a given measurement situation, from which one (or more) can be selected on the basis of its utility. This requires abandoning a principle (termed unicity), central to classical physics, that at any instant of time there is only a single correct description of the world.

  3. Geodetic distance measuring apparatus

    NASA Astrophysics Data System (ADS)

    Abshire, J. B.

    1980-12-01

    A geodetic distance measuring apparatus which compensates for the refractive index of the atmosphere is discussed. A mode locked laser system with a laser device and its peripheral components is utilized to derive two mutually phase locked optical wavelength signals and one phase locked microwave CW signal which respectively traverse the same distance measurement path. The optical signals are comprised of pulse type signals. Phase comparison of the two optical wavelength pulse signals is used to provide the dry air density while phase comparison of one of the optical wavelength pulse signals and the microwave CW signal issued to provide wet or water vapor density of the air. The distance to be measured corrected for the atmospheric dry air and water vapor densities in the measurement path is computed from these measurements. A time interval unit is included for measuring transit time of individual optical pulses for resolving the phase ambiguity needed with the phase measurements to give the true target distance.

  4. Threshold for permanent refractive index change in crystalline silicon by femtosecond laser irradiation

    NASA Astrophysics Data System (ADS)

    Bachman, D.; Chen, Z.; Fedosejevs, R.; Tsui, Y. Y.; Van, V.

    2016-08-01

    An optical damage threshold for crystalline silicon from single femtosecond laser pulses was determined by detecting a permanent change in the refractive index of the material. This index change could be detected with unprecedented sensitivity by measuring the resonant wavelength shift of silicon integrated optics microring resonators irradiated with femtosecond laser pulses at 400 nm and 800 nm wavelengths. The threshold for permanent index change at 400 nm wavelength was determined to be 0.053 ± 0.007 J/cm2, which agrees with previously reported threshold values for femtosecond laser modification of crystalline silicon. However, the threshold for index change at 800 nm wavelength was found to be 0.044 ± 0.005 J/cm2, which is five times lower than the previously reported threshold values for visual change on the silicon surface. The discrepancy is attributed to possible modification of the crystallinity of silicon below the melting temperature that has not been detected before.

  5. CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES: Microstructure and Magnetic Domains of Iron Films on Liquid Surfaces

    NASA Astrophysics Data System (ADS)

    Xie, Jian-Ping; Xia, A.-Gen; Zhang, Chu-Hang; Yang, Bo; Fang, Zheng-Nong; Ye, Gao-Xiang

    2009-11-01

    Iron (Fe) films with a thickness ranging from 1.0 nm to 80.0 nm are deposited on silicone oil surfaces by a vapor phase deposition method. The films with a thickness of d < 2.0 nm do not exhibit planar morphology but ramified aggregates instead. Magnetic force microscopy studies for the Fe films (10.0 nm <= d <= 80.0 nm) show that the domain wall structure is widespread and irregularly shaped and the oscillation phase shift Δθ, which records as the magnetic force image, changes from 0.29° to 0.81°. Correspondingly, the magnetic force gradient varies from 1.4 × 10-3 to 4.0 × 10-3 N/m, respectively. In our measurement, the characteristic domain walls, such as Bloch walls, Néel walls and cross-tie walls, are not observed in the film system clearly.

  6. Momentum spectra of electrons rescattered from rare-gas targets following their extraction by one- and two-color femtosecond laser pulses

    SciTech Connect

    Ray, D.; Chen Zhangjin; De, S.; Cao, W.; Le, A. T.; Lin, C. D.; Cocke, C. L.; Litvinyuk, I. V.; Kling, M. F.

    2011-01-15

    We have used velocity-map imaging to measure the three-dimensional momenta of electrons rescattered from Xe and Ar following the liberation of the electrons from these atoms by 45 fs, 800 nm intense laser pulses. Strong structure in the rescattering region is observed in both angle and energy, and is interpreted in terms of quantitative rescattering (QRS) theory. Momentum images have also been taken with two-color (800 nm + 400 nm) pulses on Xe targets. A strong dependence of the spectra on the relative phase of the two colors is observed in the rescattering region. Interpretation of the phase dependence using both QRS theory and a full solution to the time-dependent Schroedinger equation shows that the rescattered electrons provide a much more robust method for determining the relative phase of the two colors than do the direct electrons.

  7. Effect of curvature on the structural and magnetic properties of Ni film deposited on self-assembled nanospheres

    NASA Astrophysics Data System (ADS)

    Sharma, A.; Tripathi, S.; Gupta, Dileep; Halder, N.; Tripathi, J.

    2016-05-01

    Important experimental findings and their impact on physical properties of Ni thin film are presented with the focus on structural and magnetic property investigations. For this purpose, Ni film (40 nm) was deposited on polystyrene nanospheres (PS, diameter 800 nm) using electron beam evaporation technique simultaneously with a similar reference film on plane Si substrate. The structural properties of the films measured using XRD technique show nanocrystalline growth of Ni on both size PS spheres with an average grain size of ˜ 78 nm, while high crystallinity was observed in the film deposited onto plane Si substrate. A lower coercivity (9 mT) was observed in the Ni/(800 nm) PS as compared to the film deposited on 530 nm PS (23 mT) (our earlier study) and Ni/Si (20 mT). The observed changes in structural and magnetic properties are attributed to the curvature induced modifications at atomic level.

  8. Ultrafast optical nonlinearity and photoacoustic studies on chitosan-boron nitride nanotube composite films

    NASA Astrophysics Data System (ADS)

    Kuthirummal, Narayanan; Philip, Reji; Mohan, Athira; Jenks, Cassidy; Levi-Polyachenko, Nicole

    2016-07-01

    Ultrafast optical nonlinearity in chitosan (CS) films doped with multi-walled boron nitride nanotubes (MWBN) has been investigated using 800 nm, 100 fs laser pulses, employing the open aperture Z-scan technique. Two-photon absorption coefficients (β) of CS-MWBN films have been measured at 800 nm by Z-scan. While chitosan with 0.01% MWBN doping gives a β value of 0.28×10-13 m/W, 1% doping results in a higher β value of 1.43×10-13 m/W, showing nonlinearity enhancement by a factor of 5. These nonlinearity coefficients are comparable to those reported for silver nanoclusters in glass matrix and Pt-PVA nanocomposites, indicating potential photonic applications for MWBN doped chitosan films. Characterization of the synthesized films using Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) reveals significant interactions between the NH and CO groups of chitosan with boron nitride.

  9. Demystifying Weak Measurements

    NASA Astrophysics Data System (ADS)

    Kastner, R. E.

    2017-05-01

    A large literature has grown up around the proposed use of `weak measurements' (i.e., unsharp measurements followed by post-selection) to allegedly provide information about hidden ontological features of quantum systems. This paper attempts to clarify the fact that `weak measurements' involve strong (projective) measurements on one (pointer) member of an entangled system. The only thing `weak' about such measurements is that the correlation established via the entanglement does not correspond to eigenstates of the `weakly measured observable' for the remaining component system(s) subject to the weak measurement. All observed statistics are straightforwardly and easily predicted by standard quantum mechanics. Specifically, it is noted that measurement of the pointer steers the remaining degree(s) of freedom into new states with new statistical properties—constituting a non-trivial (even if generally small) disturbance. In addition, standard quantum mechanics readily allows us to conditionalize on a final state if we choose, so the `post-selection' that features prominently in time-symmetric formulations is also equipment from standard quantum theory. Assertions in the literature that weak measurements leave a system negligibly disturbed, and/or that standard quantum theory is cumbersome for computing the predicted measurement results, are therefore unsupportable, and ontological claims based on such assertions need to be critically reassessed.

  10. Software Measurement Guidebook

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This Software Measurement Guidebook is based on the extensive experience of several organizations that have each developed and applied significant measurement programs over a period of at least 10 years. The lessons derived from those experiences reflect not only successes but also failures. By applying those lessons, an organization can minimize, or at least reduce, the time, effort, and frustration of introducing a software measurement program. The Software Measurement Guidebook is aimed at helping organizations to begin or improve a measurement program. It does not provide guidance for the extensive application of specific measures (such as how to estimate software cost or analyze software complexity) other than by providing examples to clarify points. It does contain advice for establishing and using an effective software measurement program and for understanding some of the key lessons that other organizations have learned. Some of that advice will appear counterintuitive, but it is all based on actual experience. Although all of the information presented in this guidebook is derived from specific experiences of mature measurement programs, the reader must keep in mind that the characteristics of every organization are unique. Some degree of measurement is critical for all software development and maintenance organizations, and most of the key rules captured in this report will be generally applicable. Nevertheless, each organization must strive to understand its own environment so that the measurement program can be tailored to suit its characteristics and needs.

  11. Process measurement assurance program

    SciTech Connect

    Pettit, R.B.

    1996-05-01

    This paper describes a new method for determining, improving, and controlling the measurement process errors (or measurement uncertainty) of a measurement system used to monitor product as it is manufactured. The method is called the Process Measurement Assurance Program (PMAP). It integrates metrology early into the product realization process and is a step beyond statistical process control (SPC), which monitors only the product. In this method, a control standard is used to continuously monitor the status of the measurement system. Analysis of the control standard data allow the determination of the measurement error inherent in the product data and allow one to separate the variability in the manufacturing process from variability in the measurement process. These errors can be then associated with either the measurement equipment, variability of the measurement process, operator bias, or local environmental effects. Another goal of PMAP is to determine appropriate re-calibration intervals for the measurement system, which may be significantly longer or shorter than the interval typically assigned by the calibration organization.

  12. Locke on measurement.

    PubMed

    Anstey, Peter R

    2016-12-01

    Like many virtuosi in his day, the English philosopher John Locke maintained an active interest in metrology. Yet for Locke, this was no mere hobby: questions concerning measurement were also implicated in his ongoing philosophical project to develop an account of human understanding. This paper follows Locke's treatment of four problems of measurement from the early Drafts A and B of the Essay concerning Human Understanding to the publication of this famous book and its aftermath. It traces Locke's attempt to develop a natural or universal standard for the measure of length, his attempts to grapple with the measurement of duration, as well as the problems of determining comparative measures for secondary qualities, and the problem of discriminating small differences in the conventional measures of his day. It is argued that the salient context for Locke's treatment of these problems is the new experimental philosophy and its method of experimental natural history.

  13. Optimized measurement of gaps

    NASA Astrophysics Data System (ADS)

    Harding, Kevin; Ramamurthy, Rajesh

    2017-05-01

    Gaps are important in a wide range of measurements in manufacturing, from the fitting of critical assemblies too cosmetic features on cars. There are a variety of potential sensors that can measure a gap opening, each with aspects of gap measurements that they do well and other aspects where the technology may lack capability. This paper provides a review of a wide range of optical gages from structured light to passive systems and from line to area measurement. Each technology is considered relative to the ability to accurately measure a gap, including issues of edge effects, edge shape, surface finish, and transparency. Finally, an approach will be presented for creating an optimize measurement off gap openings for critical assembly applications.

  14. Geodetic distance measuring apparatus

    NASA Technical Reports Server (NTRS)

    Abshire, J. B. (Inventor)

    1983-01-01

    A mode locked laser system including a laser device and its peripheral components is utilized for deriving two mutually phase locked optical wavelength signals and one phase locked microwave CW signal which respectively traverse the same distance measurement path. Preferably the optical signals are comprised of pulse type signals. Phase comparison of the two optical wavelength pulse signals is used to provide a measure of the dry air density while phase comparison of one of the optical wavelength pulse signals and the microwave CW signal is used to provide a measure of the wet or water vapor density of the air. From these measurements is computed in means of the distance to be measured corrected for the atmospheric dry and water vapor densities in the measurement path.

  15. Performance Measurement at OIT

    DTIC Science & Technology

    2014-08-01

    2014 Carnegie Mellon University Performance Measurement at OIT Draft Software Engineering Institute Carnegie Mellon University Pittsburgh...OMB control number. 1. REPORT DATE 01 OCT 2014 2. REPORT TYPE N/A 3. DATES COVERED 4. TITLE AND SUBTITLE Performance Measurement at OIT ...Prescribed by ANSI Std Z39-18 2 Performance Measurement at OIT Mark Kasunic, August, 2014 © 2014 Carnegie Mellon University Copyright 2014 Carnegie

  16. Measurements of ocean color

    NASA Technical Reports Server (NTRS)

    Hovis, W. A.

    1972-01-01

    An airborne instrument for determining ocean color and measurements made with the instrument are discussed. It was concluded that a clear relationship exists between the chlorophyll concentration and the color of the water. High altitude measurements from 50,000 feet are described and the effects of atmospheric scattering on the energy reaching the sensor are examined. The measured spectrum of ocean color at high and low altitudes is plotted.

  17. PIV Measurements in Pumps

    DTIC Science & Technology

    2006-11-01

    Pump Impeller Fig. 37 shows the top view of pump test rig for radial impeller pumps . The goal of this experiment is cavitation observation and their...PIV Measurements in Pumps 5 - 28 RTO-EN-AVT-143 Figure 37: Test Rig for Combined PIV Measurements and Cavitation Observation. Figure 38...RTO-EN-AVT-143 5 - 1 PIV Measurements in Pumps Dr. Detlev L. Wulff TU Braunschweig Institut für Strömungsmaschinen Langer Kamp 6 D-38106

  18. Vega balloon meteorological measurements

    NASA Technical Reports Server (NTRS)

    Crisp, D.; Ingersoll, A. P.; Hildebrand, C. E.; Preston, R. A.

    1990-01-01

    The Vega balloons obtained in situ measurements of pressure, temperature, vertical winds, cloud density, ambient illumination, and the frequency of lightning during their flights in the Venus middle cloud layer. The Vega measurements were used to develop a comprehensive description of the meteorology of the Venus middle cloud layer. The Vega measurements provide the following picture: large horizontal temperature gradients near the equator, vigorous convection, and weather conditions that can change dramatically on time scales as short as one hour.

  19. Current measuring system

    DOEpatents

    Dahl, D.A.; Appelhans, A.D.; Olson, J.E.

    1997-09-09

    A current measuring system is disclosed comprising a current measuring device having a first electrode at ground potential, and a second electrode; a current source having an offset potential of at least three hundred volts, the current source having an output electrode; and a capacitor having a first electrode electrically connected to the output electrode of the current source and having a second electrode electrically connected to the second electrode of the current measuring device. 4 figs.

  20. Current measuring system

    DOEpatents

    Dahl, David A.; Appelhans, Anthony D.; Olson, John E.

    1997-01-01

    A current measuring system comprising a current measuring device having a first electrode at ground potential, and a second electrode; a current source having an offset potential of at least three hundred volts, the current source having an output electrode; and a capacitor having a first electrode electrically connected to the output electrode of the current source and having a second electrode electrically connected to the second electrode of the current measuring device.

  1. Measuring axial pump thrust

    DOEpatents

    Suchoza, Bernard P.; Becse, Imre

    1988-01-01

    An apparatus for measuring the hydraulic axial thrust of a pump under operation conditions is disclosed. The axial thrust is determined by forcing the rotating impeller off of an associated thrust bearing by use of an elongate rod extending coaxially with the pump shaft. The elongate rod contacts an impeller retainer bolt where a bearing is provided. Suitable measuring devices measure when the rod moves to force the impeller off of the associated thrust bearing and the axial force exerted on the rod at that time. The elongate rod is preferably provided in a housing with a heat dissipation mechanism whereby the hot fluid does not affect the measuring devices.

  2. Qualitative interviewing as measurement.

    PubMed

    Paley, John

    2010-04-01

    The attribution of beliefs and other propositional attitudes is best understood as a form of measurement, however counter-intuitive this may seem. Measurement theory does not require that the thing measured should be a magnitude, or that the calibration of the measuring instrument should be numerical. It only requires a homomorphism between the represented domain and the representing domain. On this basis, maps measure parts of the world, usually geographical locations, and 'belief' statements measure other parts of the world, namely people's aptitudes. Having outlined an argument for this view, I deal with an obvious objection to it: that self-attribution of belief cannot be an exercise in measurement, because we are all aware, from introspection, that our beliefs have an intrinsically semantic form. Subsequently, I turn to the philosophical and methodological ramifications of the measurement theoretic view. I argue, first, that it undermines at least one version of constructivism and, second, that it provides an effective alternative to the residually Cartesian philosophy that underpins much qualitative research. Like other anti-Cartesian strategies, belief-attribution-as-measurement implies that the objective world is far more knowable than the subjective one, and that reality is ontologically prior to meaning. I regard this result as both plausible and welcome.

  3. Measuring axial pump thrust

    DOEpatents

    Suchoza, B.P.; Becse, I.

    1988-11-08

    An apparatus for measuring the hydraulic axial thrust of a pump under operation conditions is disclosed. The axial thrust is determined by forcing the rotating impeller off of an associated thrust bearing by use of an elongate rod extending coaxially with the pump shaft. The elongate rod contacts an impeller retainer bolt where a bearing is provided. Suitable measuring devices measure when the rod moves to force the impeller off of the associated thrust bearing and the axial force exerted on the rod at that time. The elongate rod is preferably provided in a housing with a heat dissipation mechanism whereby the hot fluid does not affect the measuring devices. 1 fig.

  4. Broadband Radiometric LED Measurements

    PubMed Central

    Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

    2017-01-01

    At present, broadband radiometric measurements of LEDs with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(λ) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irradiance meters with spectrally constant response and high-intensity LED irradiance sources were developed here to implement the previously suggested broadband radiometric LED measurement procedure [1, 2]. Using a detector with spectrally constant response, the broadband radiometric quantities of any LEDs or LED groups can be simply measured with low uncertainty without using any source standard. The spectral flatness of filtered-Si detectors and low-noise pyroelectric radiometers are compared. Examples are given for integrated irradiance measurement of UV and blue LED sources using the here introduced reference (standard) pyroelectric irradiance meters. For validation, the broadband measured integrated irradiance of several LED-365 sources were compared with the spectrally determined integrated irradiance derived from an FEL spectral irradiance lamp-standard. Integrated responsivity transfer from the reference irradiance meter to transfer standard and field UV irradiance meters is discussed. PMID:28649167

  5. Space Acceleration Measurement Systems

    NASA Technical Reports Server (NTRS)

    Foster, William

    2000-01-01

    The Space Acceleration Measurement Systems (SAMS) Project develops and deploys the measurement systems for the Acceleration Measurement Program (AMP). At this time there are two types of measurement systems available, quasi-steady and vibratory. Orbital Acceleration Research Experiment (OARE) and Microgravity Acceleration Measurement System (MAMS) are the current quasi-steady systems available. OARE has flown numerous times supporting STS missions. MAMS has been delivered to Kennedy Space Center (KSC) for its deployment on the International Space Station (ISS). Vibratory measurements have been made and will be made by the Space Acceleration Measurement System (SAMS-I) Generation I, Space Acceleration Measurement System Generation II (SAMS-II), and Space Acceleration Measurement System Free Flyer or Generation III (SAMS-FF). SAMS-I supported 21 STS missions and has been retired. SAMS-II will be delivered to KSC to support ISS-6A launch (currently April 19, 2001). SAMS-FF has replaced SAMS-I in support of STS missions and has been deployed on sounding rockets, the KC-135 and ground facilities. SAMS-FF hardware shall be deployed on ISS in the future to provide a more compact solution.

  6. Global Precipitation Measurement

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.; Skofronick-Jackson, Gail; Kummerow, Christian D.; Shepherd, James Marshall

    2008-01-01

    This chapter begins with a brief history and background of microwave precipitation sensors, with a discussion of the sensitivity of both passive and active instruments, to trace the evolution of satellite-based rainfall techniques from an era of inference to an era of physical measurement. Next, the highly successful Tropical Rainfall Measuring Mission will be described, followed by the goals and plans for the Global Precipitation Measurement (GPM) Mission and the status of precipitation retrieval algorithm development. The chapter concludes with a summary of the need for space-based precipitation measurement, current technological capabilities, near-term algorithm advancements and anticipated new sciences and societal benefits in the GPM era.

  7. Measuring School Contexts

    PubMed Central

    Muller, Chandra L.

    2016-01-01

    This article describes issues in measuring school contexts with an eye toward understanding students’ experiences and outcomes. I begin with an overview of the conceptual underpinnings related to measuring contexts, briefly describe the initiatives at the National Center for Education Statistics to measure school contexts, and identify possible gaps in those initiatives that if filled could provide valuable new data for researchers. Next, I discuss new approaches and opportunities for measurement, and special considerations related to diverse populations and youth development. I conclude with recommendations for future priorities. PMID:27158640

  8. Photothermal measurements of superconductors

    SciTech Connect

    Kino, G.S.; Studenmund, W.R.; Fishman, I.M.

    1996-12-31

    A photothermal technique has been used to measure diffusion and critical temperature in high temperature superconductors. The technique is particularly suitable for determining material quality and inhomogeneity.

  9. Why Measure Outcomes?

    PubMed

    Kuhn, John E

    2016-01-01

    The concept of measuring the outcomes of treatment in health care was promoted by Ernest Amory Codman in the early 1900s, but, until recently, his ideas were generally ignored. The forces that have advanced outcome measurement to the forefront of health care include the shift in payers for health care from the patient to large insurance companies or government agencies, the movement toward assessing the care of populations not individuals, and the effort to find value (or cost-effective treatments) amid rising healthcare costs. No ideal method exists to measure outcomes, and the information gathered depends on the reason the outcome information is required. Outcome measures used in research are best able to answer research questions. The methods for assessing physician and hospital performance include process measures, patient-experience measures, structure measures, and measures used to assess the outcomes of treatment. The methods used to assess performance should be validated, be reliable, and reflect a patient's perception of the treatment results. The healthcare industry must measure outcomes to identify which treatments are most effective and provide the most benefit to patients.

  10. Remote Raman measurement techniques

    NASA Technical Reports Server (NTRS)

    Leonard, D. A.

    1981-01-01

    The use of laser Raman measurement techniques in remote sensing applications is surveyed. A feasibility index is defined as a means to characterize the practicality of a given remote Raman measurement application. Specific applications of Raman scattering to the measurement of atmospheric water vapor profiles, methane plumes from liquid natural gas spills, and subsurface ocean temperature profiles are described. This paper will survey the use of laser Raman measurement techniques in remote sensing applications using as examples specific systems that the Computer Genetics Corporation (CGC) group has developed and engineered.

  11. "Measurement" of Tinnitus.

    PubMed

    Henry, James A

    2016-09-01

    Chronic tinnitus is the persistent sensation of hearing a sound that exists only inside the head. The prevalence of tinnitus in adults in the United States is estimated at 10 to 15%. For about 20% of these individuals the tinnitus is significantly bothersome. Although myriad therapies for tinnitus are offered (often at significant cost), most are not evidence based. Difficulty in the assessment and further development of interventions for tinnitus stems from the limitations of techniques used to evaluate these interventions. Questionnaires are widely available to "measure" (tinnitus can only be indirectly measured) functional effects of tinnitus, such as difficulty sleeping and concentrating, and negative emotions such as anxiety, depression, and annoyance. Questionnaires have recently been documented for sensitivity to change in response to intervention (i.e., "responsiveness"). All of these questionnaires function well to assess the overall impact of tinnitus. The limitations mentioned pertain primarily to measures of tinnitus perception, which typically include the psychoacoustic measures of tinnitus loudness and pitch matches, tinnitus spectral content, minimum masking levels, and residual inhibition. These measures, which are obtained routinely in many clinics and as part of research studies, have not been validated for being diagnostic, prognostic, discriminative, or responsive. In order for these measures to become clinically meaningful, normative standards are needed, both for baseline measures and for repeated measures of tinnitus perception. Evidence-based intervention for tinnitus requires accurately measuring both the perception of, and reactions to, tinnitus.

  12. Broadband radiometric LED measurements

    NASA Astrophysics Data System (ADS)

    Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

    2016-09-01

    At present, broadband radiometric LED measurements with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(λ) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irradiance meters with spectrally constant response and high-intensity LED irradiance sources were developed here to implement the previously suggested broadband radiometric LED measurement procedure [1, 2]. Using a detector with spectrally constant response, the broadband radiometric quantities of any LEDs or LED groups can be simply measured with low uncertainty without using any source standard. The spectral flatness of filtered-Si detectors and low-noise pyroelectric radiometers are compared. Examples are given for integrated irradiance measurement of UV and blue LED sources using the here introduced reference (standard) pyroelectric irradiance meters. For validation, the broadband measured integrated irradiance of several LED-365 sources were compared with the spectrally determined integrated irradiance derived from an FEL spectral irradiance lamp-standard. Integrated responsivity transfer from the reference irradiance meter to transfer standard and field UV irradiance meters is discussed.

  13. The attribute measurement technique

    SciTech Connect

    Macarthur, Duncan W; Langner, Diana; Smith, Morag; Thron, Jonathan; Razinkov, Sergey; Livke, Alexander

    2010-01-01

    Any verification measurement performed on potentially classified nuclear material must satisfy two seemingly contradictory constraints. First and foremost, no classified information can be released. At the same time, the monitoring party must have confidence in the veracity of the measurement. An information barrier (IB) is included in the measurement system to protect the potentially classified information while allowing sufficient information transfer to occur for the monitoring party to gain confidence that the material being measured is consistent with the host's declarations, concerning that material. The attribute measurement technique incorporates an IB and addresses both concerns by measuring several attributes of the nuclear material and displaying unclassified results through green (indicating that the material does possess the specified attribute) and red (indicating that the material does not possess the specified attribute) lights. The attribute measurement technique has been implemented in the AVNG, an attribute measuring system described in other presentations at this conference. In this presentation, we will discuss four techniques used in the AVNG: (1) the 1B, (2) the attribute measurement technique, (3) the use of open and secure modes to increase confidence in the displayed results, and (4) the joint design as a method for addressing both host and monitor needs.

  14. Systemic risk measures

    NASA Astrophysics Data System (ADS)

    Guerra, Solange Maria; Silva, Thiago Christiano; Tabak, Benjamin Miranda; de Souza Penaloza, Rodrigo Andrés; de Castro Miranda, Rodrigo César

    2016-01-01

    In this paper we present systemic risk measures based on contingent claims approach and banking sector multivariate density. We also apply network measures to analyze bank common risk exposure. The proposed measures aim to capture credit risk stress and its potential to become systemic. These indicators capture not only individual bank vulnerability, but also the stress dependency structure between them. Furthermore, these measures can be quite useful for identifying systemically important banks. The empirical results show that these indicators capture with considerable fidelity the moments of increasing systemic risk in the Brazilian banking sector in recent years.

  15. Force-Measuring Clamps

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark

    2003-01-01

    Force-measuring clamps have been invented to facilitate and simplify the task of measuring the forces or pressures applied to clamped parts. There is a critical need to measure clamping forces or pressures in some applications for example, while bonding sensors to substrates or while clamping any sensitive or delicate parts. Many manufacturers of adhesives and sensors recommend clamping at specific pressures while bonding sensors or during adhesive bonding between parts in general. In the absence of a force-measuring clamp, measurement of clamping force can be cumbersome at best because of the need for additional load sensors and load-indicating equipment. One prior method of measuring clamping force involved the use of load washers or miniature load cells in combination with external power sources and load-indicating equipment. Calibrated spring clamps have also been used. Load washers and miniature load cells constitute additional clamped parts in load paths and can add to the destabilizing effects of loading mechanisms. Spring clamps can lose calibration quickly through weakening of the springs and are limited to the maximum forces that the springs can apply. The basic principle of a force-measuring clamp can be implemented on a clamp of almost any size and can enable measurement of a force of almost any magnitude. No external equipment is needed because the component(s) for transducing the clamping force and the circuitry for supplying power, conditioning the output of the transducers, and displaying the measurement value are all housed on the clamp. In other words, a force-measuring clamp is a complete force-application and force-measurement system all in one package. The advantage of unitary packaging of such a system is that it becomes possible to apply the desired clamping force or pressure with precision and ease.

  16. Simultaneous dual-band spectral domain optical coherence tomography using a supercontinuum laser light source

    NASA Astrophysics Data System (ADS)

    Cimalla, Peter; Mehner, Mirko; Cuevas, Maximiliano; Walther, Julia; Koch, Edmund

    2009-07-01

    Optical coherence tomography (OCT) is performed in the spectral domain simultaneously at two different wavelength bands centered at 800 nm and 1250 nm. A novel commercial supercontinuum laser is applied as a single light source whose emission spectrum is shaped by optical and spatial filtering to obtain an adequate double peak spectrum. After spectral shaping, the wavelength bands 700 - 900 nm and 1100 - 1400 nm are used for OCT imaging. A fiber-coupled setup optimized for both spectral regions facilitates easy and flexible access to the measurement area. Each wavelength band is analyzed with an individual spectrometer at an A-scan rate of about 12 kHz which allows real-time sample examination. The free-space axial resolutions were measured to be less than 4.5 μm and 7 μm at 800 nm and 1250 nm, respectively. This technique combines the high resolution at 800 nm with the enhanced imaging depth at 1250 nm. Furthermore, spatially resolved spectroscopic sample features are extracted by comparing the backscattering properties at the two different wavelength bands, showing the ability of dual-band OCT to enhance image contrast.

  17. Attosecond probing of state-resolved ionization and superpositions of atoms and molecules

    NASA Astrophysics Data System (ADS)

    Leone, Stephen

    2016-05-01

    Isolated attosecond pulses in the extreme ultraviolet are used to probe strong field ionization and to initiate electronic and vibrational superpositions in atoms and small molecules. Few-cycle 800 nm pulses produce strong-field ionization of Xe atoms, and the attosecond probe is used to measure the risetimes of the two spin orbit states of the ion on the 4d inner shell transitions to the 5p vacancies in the valence shell. Step-like features in the risetimes due to the subcycles of the 800 nm pulse are observed and compared with theory to elucidate the instantaneous and effective hole dynamics. Isolated attosecond pulses create massive superpositions of electronic states in Ar and nitrogen as well as vibrational superpositions among electronic states in nitrogen. An 800 nm pulse manipulates the superpositions, and specific subcycle interferences, level shifting, and quantum beats are imprinted onto the attosecond pulse as a function of time delay. Detailed outcomes are compared to theory for measurements of time-dynamic superpositions by attosecond transient absorption. Supported by DOE, NSF, ARO, AFOSR, and DARPA.

  18. Measurement of Mass.

    ERIC Educational Resources Information Center

    Zimmerer, Robert W.

    1983-01-01

    Various instruments and techniques for measuring mass are discussed, focusing on the physics behind techniques employed. Equal-arm balances, electronic substitution balance (using electromagnetic force), non-gravimetric weighing (intertial-mass measurement) are among the instruments/techniques considered. (JN)

  19. Metrology Measurement Capabilities

    SciTech Connect

    Dr. Glen E. Gronniger

    2007-10-02

    This document contains descriptions of Federal Manufacturing & Technologies (FM&T) Metrology capabilities, traceability flow charts, and the measurement uncertainty of each measurement capability. Metrology provides NIST traceable precision measurements or equipment calibration for a wide variety of parameters, ranges, and state-of-the-art uncertainties. Metrology laboratories conform to the requirements of the Department of Energy Development and Production Manual Chapter 13.2, ANSI/ISO/IEC ANSI/ISO/IEC 17025:2005, and ANSI/NCSL Z540-1. FM&T Metrology laboratories are accredited by NVLAP for the parameters, ranges, and uncertainties listed in the specific scope of accreditation under NVLAP Lab code 200108-0. See the Internet at http://ts.nist.gov/Standards/scopes/2001080.pdf. These parameters are summarized. The Honeywell Federal Manufacturing & Technologies (FM&T) Metrology Department has developed measurement technology and calibration capability in four major fields of measurement: (1) Mechanical; (2) Environmental, Gas, Liquid; (3) Electrical (DC, AC, RF/Microwave); and (4) Optical and Radiation. Metrology Engineering provides the expertise to develop measurement capabilities for virtually any type of measurement in the fields listed above. A strong audit function has been developed to provide a means to evaluate the calibration programs of our suppliers and internal calibration organizations. Evaluation includes measurement audits and technical surveys.

  20. Measures of Biochemical Sociology

    ERIC Educational Resources Information Center

    Snell, Joel; Marsh, Mitchell

    2008-01-01

    In a previous article, the authors introduced a new sub field in sociology that we labeled "biochemical sociology." We introduced the definition of a sociology that encompasses sociological measures, psychological measures, and biological indicators Snell & Marsh (2003). In this article, we want to demonstrate a research strategy that would assess…

  1. Meteorological measurements. Chapter 3

    Treesearch

    David Y. Hollinger

    2008-01-01

    Environmental measurements are useful for detecting climatic trends, understanding how the environment influences biological processes, and as input to ecosystem models. Landscape-scale monitoring requires a suite of environmental measures for all of these purposes, including air and soil temperature, humidity, wind speed, precipitation and soil moisture, and different...

  2. Measuring News Media Literacy

    ERIC Educational Resources Information Center

    Maksl, Adam; Ashley, Seth; Craft, Stephanie

    2015-01-01

    News media literacy refers to the knowledge and motivations needed to identify and engage with journalism. This study measured levels of news media literacy among 500 teenagers using a new scale measure based on Potter's model of media literacy and adapted to news media specifically. The adapted model posits that news media literate individuals…

  3. Measuring software design

    NASA Technical Reports Server (NTRS)

    1986-01-01

    An extensive series of studies of software design measures conducted by the Software Engineering Laboratory is described. Included are the objectives and results of the studies, the method used to perform the studies, and the problems encountered. The document should be useful to researchers planning similar studies as well as to managers and designers concerned with applying quantitative design measures.

  4. Acoustics, computers and measurements

    NASA Astrophysics Data System (ADS)

    Truchard, James J.

    2003-10-01

    The human ear has created a high standard for the requirements of acoustical measurements. The transient nature of most acoustical signals has limited the success of traditional volt meters. Professor Hixson's pioneering work in electroacoustical measurements at ARL and The University of Texas helped set the stage for modern computer-based measurements. The tremendous performance of modern PCs and extensive libraries of signal processing functions in virtual instrumentation application software has revolutionized the way acoustical measurements are made. Today's analog to digital converters have up to 24 bits of resolution with a dynamic range of over 120 dB and a single PC processor can process 112 channels of FFTs at 4 kHz in real time. Wavelet technology further extends the capabilities for analyzing transients. The tools available for measurements in speech, electroacoustics, noise, and vibration represent some of the most advanced measurement tools available. During the last 50 years, Professor Hixson has helped drive this revolution from simple oscilloscope measurements to the modern high performance computer-based measurements.

  5. Basic Measures of Progress.

    ERIC Educational Resources Information Center

    Calkins, Julia; Ling, Thomson; Moore, Eric; Halle, Tamara; Hair, Beth; Moore, Kris; Zaslow, Marty

    This document provides a compilation of measures of progress toward school readiness and three contributing conditions as used in several local, state, and national surveys. The report begins with a legend listing the surveys examined, their acronyms, and contact information. The remainder of the report, in tabular format, lists measures of…

  6. ANOVA with Rasch Measures.

    ERIC Educational Resources Information Center

    Linacre, John Michael

    Various methods of estimating main effects from ordinal data are presented and contrasted. Problems discussed include: (1) at what level to accumulate ordinal data into linear measures; (2) how to maintain scaling across analyses; and (3) the inevitable confounding of within cell variance with measurement error. An example shows three methods of…

  7. Measuring News Media Literacy

    ERIC Educational Resources Information Center

    Maksl, Adam; Ashley, Seth; Craft, Stephanie

    2015-01-01

    News media literacy refers to the knowledge and motivations needed to identify and engage with journalism. This study measured levels of news media literacy among 500 teenagers using a new scale measure based on Potter's model of media literacy and adapted to news media specifically. The adapted model posits that news media literate individuals…

  8. Human performance measuring device

    NASA Technical Reports Server (NTRS)

    Michael, J.; Scow, J.

    1970-01-01

    Complex coordinator, consisting of operator control console, recorder, subject display panel, and limb controls, measures human performance by testing perceptual and motor skills. Device measures psychophysiological functions in drug and environmental studies, and is applicable to early detection of psychophysiological body changes.

  9. Metabolic rate measurement system

    NASA Technical Reports Server (NTRS)

    Koester, K.; Crosier, W.

    1980-01-01

    The Metabolic Rate Measurement System (MRMS) is an uncomplicated and accurate apparatus for measuring oxygen consumption and carbon dioxide production of a test subject. From this one can determine the subject's metabolic rate for a variety of conditions, such as resting or light exercise. MRMS utilizes an LSI/11-03 microcomputer to monitor and control the experimental apparatus.

  10. Gummy Worm Measurements.

    ERIC Educational Resources Information Center

    Callison, Priscilla L.; Anshutz, Ramona J.; Wright, Emmett L.

    1997-01-01

    Describes a science activity using gummy worms to help primary students develop the mathematical skills of measurement concepts, units of measure, estimation, and graphing needed for science learning. Groups of two begin by estimating the number of gummy worms in their package and identifying the colors they expect to find. Individual worms are…

  11. Undulator Field Integral Measurements

    SciTech Connect

    Wolf, Zachary

    2010-12-07

    The LCLS undulator field integrals must be very small so that the beam trajectory slope and offset stay within tolerance. In order to make accurate measurements of the small field integrals, a long coil will be used. This note describes the design of the coil measurement system.

  12. Bullen Reading Attitude Measure.

    ERIC Educational Resources Information Center

    Bullen, Gertrude F.

    The Bullen Reading Attitude Measure (BRAM) is an instrument that was developed to serve as a diagnostic aid in assessing reading attitudes of elementary school children in grades one through six. The objectives of the test are to measure the subject's attitude toward reading at home or school, visiting the library, owning and buying books,…

  13. Electron measurement in PHENIX

    SciTech Connect

    Akiba, Y.

    1995-07-15

    Electron Measurement in PHENIX detector at RHIC is discussed. The yield and S/N ratio at vector meson peaks ({phi}, {omega}, {rho}{sup o}, and J/{psi}) are evaluated. The electrons from open charm decay, and its consequence to the di-electron measurements is discussed.

  14. The Measurement of Nonviolence.

    ERIC Educational Resources Information Center

    Mayton, Daniel M., II; Palmer, B. James

    This paper reviews the assessment measures developed to recognize nonviolent dispositions. Based on computer searches of the Psychological Abstracts (PsychLit) database, the document identifies the best measures for assessing nonviolence such as: (1) The Nonviolence Test developed by Kool and Sen (1984); (2) the Gandhian Personality Scale…

  15. Systems Engineering Measurement Primer

    DTIC Science & Technology

    1998-03-01

    Systems Engineering Measurement Primer A Basic Introduction to Systems Engineering Measurement Concepts and Use Version 1.0 March 1998 This document...Federal Systems Garry Roedler Lockheed Martin Management & Data Systems Cathy Tilton The National Registry, Inc. E. Richard Widmann Raytheon Systems...IV 1. INTRODUCTION

  16. Gummy Worm Measurements.

    ERIC Educational Resources Information Center

    Callison, Priscilla L.; Anshutz, Ramona J.; Wright, Emmett L.

    1997-01-01

    Describes a science activity using gummy worms to help primary students develop the mathematical skills of measurement concepts, units of measure, estimation, and graphing needed for science learning. Groups of two begin by estimating the number of gummy worms in their package and identifying the colors they expect to find. Individual worms are…

  17. Measuring Relational Reasoning

    ERIC Educational Resources Information Center

    Alexander, Patricia A.; Dumas, Denis; Grossnickle, Emily M.; List, Alexandra; Firetto, Carla M.

    2016-01-01

    Relational reasoning is the foundational cognitive ability to discern meaningful patterns within an informational stream, but its reliable and valid measurement remains problematic. In this investigation, the measurement of relational reasoning unfolded in three stages. Stage 1 entailed the establishment of a research-based conceptualization of…

  18. Measuring Facial Movement

    ERIC Educational Resources Information Center

    Ekman, Paul; Friesen, Wallace V.

    1976-01-01

    The Facial Action Code (FAC) was derived from an analysis of the anatomical basis of facial movement. The development of the method is explained, contrasting it to other methods of measuring facial behavior. An example of how facial behavior is measured is provided, and ideas about research applications are discussed. (Author)

  19. Balloon film strain measurement

    NASA Astrophysics Data System (ADS)

    Rand, James L.

    In order to understand the state of stress in scientific balloons, a need exists for the measurement of film deformation in flight. The results of a flight test program are reported where material strain was measured for the first time during the inflation, launch, ascent and float of a typical natural shape, zero pressure scientific balloon.

  20. PAL Measures Language Dominance.

    ERIC Educational Resources Information Center

    Gil, Sylvia

    The Primary Acquisition of Languages Oral Language Dominance Measure (PAL) developed by the El Paso Independent School District determines a child's structural proficiency in English and Spanish and measures language dominance to aid in placing pupils in bilingual programs. PAL consists of four components, including an examiner's manual containing…

  1. Measuring Poverty: A Rejoinder

    ERIC Educational Resources Information Center

    Iceland, John

    2005-01-01

    This article presents the author's rejoinder on commentaries of his article which illustrate the variety of perspectives with which people approach poverty measurement issues. Some of the comments highlight the theoretical concerns underpinning poverty measurement efforts, whereas others focus on empirical considerations. As a social scientist,…

  2. Measuring Authoritative Teaching

    ERIC Educational Resources Information Center

    Ertesvag, Sigrun K.

    2011-01-01

    High quality measurements are important to evaluate interventions. The study reports on the development of a measurement to investigate authoritative teaching understood as a two-dimensional construct of warmth and control. Through the application of confirmatory factor analysis (CFA) and structural equation modelling (SEM) the factor structure…

  3. Measures of Biochemical Sociology

    ERIC Educational Resources Information Center

    Snell, Joel; Marsh, Mitchell

    2008-01-01

    In a previous article, the authors introduced a new sub field in sociology that we labeled "biochemical sociology." We introduced the definition of a sociology that encompasses sociological measures, psychological measures, and biological indicators Snell & Marsh (2003). In this article, we want to demonstrate a research strategy that would assess…

  4. Measuring Facial Movement

    ERIC Educational Resources Information Center

    Ekman, Paul; Friesen, Wallace V.

    1976-01-01

    The Facial Action Code (FAC) was derived from an analysis of the anatomical basis of facial movement. The development of the method is explained, contrasting it to other methods of measuring facial behavior. An example of how facial behavior is measured is provided, and ideas about research applications are discussed. (Author)

  5. Measuring Authoritative Teaching

    ERIC Educational Resources Information Center

    Ertesvag, Sigrun K.

    2011-01-01

    High quality measurements are important to evaluate interventions. The study reports on the development of a measurement to investigate authoritative teaching understood as a two-dimensional construct of warmth and control. Through the application of confirmatory factor analysis (CFA) and structural equation modelling (SEM) the factor structure…

  6. Measuring Relational Reasoning

    ERIC Educational Resources Information Center

    Alexander, Patricia A.; Dumas, Denis; Grossnickle, Emily M.; List, Alexandra; Firetto, Carla M.

    2016-01-01

    Relational reasoning is the foundational cognitive ability to discern meaningful patterns within an informational stream, but its reliable and valid measurement remains problematic. In this investigation, the measurement of relational reasoning unfolded in three stages. Stage 1 entailed the establishment of a research-based conceptualization of…

  7. Thoughts on Attitude Measurement

    ERIC Educational Resources Information Center

    Reid, Norman

    2006-01-01

    Attitude measurement has had a somewhat chequered history since the possibility of achieving it successfully was demonstrated by Thurstone in 1929. It has been an important area in science education, particularly in the context of falling uptakes in the physical sciences in many countries, and there have been many attempts to measure learner…

  8. Lavosier Measures with Polymers.

    ERIC Educational Resources Information Center

    Goates, Wayne

    2000-01-01

    Presents a creative, hands-on activity for teaching measurement skills inspired by Antoine Laurent Lavosier and a product called polyacrylamide spikes for students to develop their metric measurement skills and boost their math proficiency as they interpret data and results from their investigations. (ASK)

  9. Measuring Clerical Job Performance

    ERIC Educational Resources Information Center

    Ronan, William W.; And Others

    1976-01-01

    Describes research which attempts to provide a solution to the performance criterion problem, concluding that is seems possible to measure many aspects of clerical work using psychometric measures that are highly job related; recommends that such devices be used to supplement ratings in the performance evaluation process.

  10. Performance Measurement Redux.

    ERIC Educational Resources Information Center

    Feller, Irwin

    2002-01-01

    Continues the exploration of the effective use and misuse of performance indicators that has been conducted by various authors in this journal. Identifies some further limitations on the use of performance measurement and notes that many performance measurement undertakings make no provision for evaluating the impact of the undertakings…

  11. NBS: Materials measurements

    NASA Technical Reports Server (NTRS)

    Manning, J. R.

    1981-01-01

    Measurement of materials properties and thermophysical properties is described. The topics discussed are: surface tensions and their variations with temperature and impurities; convection during unidirectional solidification: measurement of high temperature thermophysical properties of tungsten liquid and solid; thermodynamic properties of refractory materials at high temperatures; and experimental and theoretical studies in wetting and multilayer adsorption.

  12. Measuring cosmological parameters

    PubMed Central

    Freedman, Wendy L.

    1998-01-01

    In this review, the status of measurements of the matter density (Ωm), the vacuum energy density or cosmological constant (ΩΛ), the Hubble constant (H0), and the ages of the oldest measured objects (t0) are summarized. Three independent types of methods for measuring the Hubble constant are considered: the measurement of time delays in multiply imaged quasars, the Sunyaev–Zel’dovich effect in clusters, and Cepheid-based extragalactic distances. Many recent independent dynamical measurements are yielding a low value for the matter density (Ωm ≈ 0.2–0.3). A wide range of Hubble constant measurements appear to be converging in the range of 60–80 km/sec per megaparsec. Areas where future improvements are likely to be made soon are highlighted—in particular, measurements of anisotropies in the cosmic microwave background. Particular attention is paid to sources of systematic error and the assumptions that underlie many of the measurement methods. PMID:9419315

  13. Viscosity measuring using microcantilevers

    DOEpatents

    Oden, Patrick Ian

    2001-01-01

    A method for the measurement of the viscosity of a fluid uses a micromachined cantilever mounted on a moveable base. As the base is rastered while in contact with the fluid, the deflection of the cantilever is measured and the viscosity determined by comparison with standards.

  14. Informational aesthetics measures.

    PubMed

    Rigau, Jaume; Feixas, Miquel; Sbert, Mateu

    2008-01-01

    The Birkhoff aesthetic measure of an object is the ratio between order and complexity. Informational aesthetics describes the interpretation of this measure from an information-theoretic perspective. From these ideas, the authors define a set of ratios based on information theory and Kolmogorov complexity that can help to quantify the aesthetic experience.

  15. Symmetry operation measures.

    PubMed

    Pinsky, Mark; Casanova, David; Alemany, Pere; Alvarez, Santiago; Avnir, David; Dryzun, Chaim; Kizner, Ziv; Sterkin, Alexander

    2008-01-30

    We introduce a new mathematical tool for quantifying the symmetry contents of molecular structures: the Symmetry Operation Measures. In this approach, we measure the minimal distance between a given structure and the structure which is obtained after applying a selected symmetry operation on it. If the given operation is a true symmetry operation for the structure, this distance is zero; otherwise it gives an indication of how different the transformed structure is from the original one. Specifically, we provide analytical solutions for measures of all the improper rotations, S n p, including mirror symmetry and inversion, as well as for all pure rotations, C n p. These measures provide information complementary to the Continuous Symmetry Measures (CSM) that evaluate the distance between a given structure and the nearest structure which belongs to a selected symmetry point-group.

  16. Heat Flow Measurement

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Heat gauges are used to measure heat flow in industrial activities. They must periodically be certified by instruments designed to provide a heat flux measurement standard. CSTAR, a NASA CCDS, and REMTECH have developed a portable heat flux checker/calibrator. The Q-CHEC can be carried to the heat gauge for certification, reducing out of service time for the gauge and eliminating the need for a replacement gauge during certification. It can provide an "end-to-end" check of the instrumentation measurement system or be used as a standalone calibrator. Because Q-CHEC offers on-site capability to detect and eliminate measurement errors, measurements do not have to be repeated, and money is saved.

  17. Measurement of academic entitlement.

    PubMed

    Miller, Brian K

    2013-10-01

    Members of Generation Y, or Millennials, have been accused of being lazy, whiny, pampered, and entitled, particularly in the college classroom. Using an equity theory framework, eight items from a measure of work entitlement were adapted to measure academic entitlement in a university setting in three independent samples. In Study 1 (n = 229), confirmatory factor analyses indicated good model fit to a unidimensional structure for the data. In Study 2 (n = 200), the questionnaire predicted unique variance in university satisfaction beyond two more general measures of dispositional entitlement. In Study 3 (n = 161), the measure predicted unique variance in perceptions of grade fairness beyond that which was predicted by another measure of academic entitlement. This analysis provides evidence of discriminant, convergent, incremental, concurrent criterion-related, and construct validity for the Academic Equity Preference Questionnaire.

  18. Chapter one: exposure measurements.

    PubMed

    Chow, Judith C; Engelbrecht, Johann P; Freeman, Natalie C G; Hashim, Jamal Hisham; Jantunen, Matti; Michaud, Jon-Pierre; Saenz de Tejada, Sandra; Watson, John G; Wei, Fusheng; Wilson, William E; Yasuno, Mayayuki; Zhu, Tan

    2002-12-01

    Determining human exposure to suspended particulate concentrations requires measurements that quantify different particle properties in microenvironments where people live, work, and play. Particle mass, size, and chemical composition are important exposure variables, and these are typically measured with time-integrated samples on filters that are later submitted to laboratory analyses. This requires substantial sample handling, quality assurance, and data reduction. Newer technologies are being developed that allow in-situ, time-resolved measurements for mass, carbon, sulfate, nitrate, particle size, and other variables. These are large measurement systems that are more suitable for fixed monitoring sites than for personal applications. Human exposure studies need to be designed to accomplish specific objectives rather than to serve too many purposes. Resources need to be divided among study design, field sampling, laboratory analysis, quality assurance, data management, and data analysis phases. Many exposure projects allocated too little to the non-measurement activities.

  19. Accurate spectral color measurements

    NASA Astrophysics Data System (ADS)

    Hiltunen, Jouni; Jaeaeskelaeinen, Timo; Parkkinen, Jussi P. S.

    1999-08-01

    Surface color measurement is of importance in a very wide range of industrial applications including paint, paper, printing, photography, textiles, plastics and so on. For a demanding color measurements spectral approach is often needed. One can measure a color spectrum with a spectrophotometer using calibrated standard samples as a reference. Because it is impossible to define absolute color values of a sample, we always work with approximations. The human eye can perceive color difference as small as 0.5 CIELAB units and thus distinguish millions of colors. This 0.5 unit difference should be a goal for the precise color measurements. This limit is not a problem if we only want to measure the color difference of two samples, but if we want to know in a same time exact color coordinate values accuracy problems arise. The values of two instruments can be astonishingly different. The accuracy of the instrument used in color measurement may depend on various errors such as photometric non-linearity, wavelength error, integrating sphere dark level error, integrating sphere error in both specular included and specular excluded modes. Thus the correction formulas should be used to get more accurate results. Another question is how many channels i.e. wavelengths we are using to measure a spectrum. It is obvious that the sampling interval should be short to get more precise results. Furthermore, the result we get is always compromise of measuring time, conditions and cost. Sometimes we have to use portable syste or the shape and the size of samples makes it impossible to use sensitive equipment. In this study a small set of calibrated color tiles measured with the Perkin Elmer Lamda 18 and the Minolta CM-2002 spectrophotometers are compared. In the paper we explain the typical error sources of spectral color measurements, and show which are the accuracy demands a good colorimeter should have.

  20. Turbulent Inflow Measurements

    NASA Technical Reports Server (NTRS)

    George, Albert R.

    1996-01-01

    In the present research, tilt rotor aeroacoustics have been studied experimentally and computationally. Experimental measurements were made on a 1/12.5 scale model. A dimensional analysis showed that the model was a good aeroacoustic approximation to the full-scale aircraft, and scale factors were derived to extrapolate the model measurements to the full-scale XV-15. The experimental measurements included helium bubble flow visualization, silk tuft flow visualization, 2-component hot wire anemometry, 7-hole pressure probe measurements, vorticity measurements, and outdoor far field acoustic measurements. The hot wire measurements were used to estimate the turbulence statistics of the flow field into the rotors, such as length scales, velocity scales, dissipation, and turbulence intermittency. To date, these flow measurements are the only ones in existence for a hovering tilt rotor. Several different configurations of the model were tested: (1) standard configurations (single isolated rotor, two rotors without the aircraft, standard tilt rotor configuration); (2) flow control devices (the 'plate', the 'diagonal fences'); (3) basic configuration changes (increasing the rotor/rotor spacing, reducing the rotor plane/wing clearance, operating the rotors out of phase). Also, an approximation to Sikorsky's Variable Diameter Tilt Rotor (VDTR) configuration was tested, and some flow measurements were made on a semi-span configuration of the model. Acoustic predictions were made using LOWSON.M, a Mathematica code. This hover prediction code, from HOVER.FOR, used blade element theory for the aerodynamics, and Prandtl's Vortex theory to model the wake, along with empirical formulas for the effects of Reynolds number, Mach number, and stall. Aerodynamic models were developed from 7-hole pressure probe measurements of the mean velocity into the model rotors. LOWSON.M modeled a rotor blade as a single force and source/sink combination separated in the chordwise direction, at an

  1. Why measure tumours?

    PubMed

    Olsen, Øystein E

    2015-01-01

    This article questions the scientific justification of ingrained radiologic practices exemplified by size measurements of childhood solid tumours. This is approached by a critical review of staging systems from a selection of paediatric oncological treatment protocols. Local staging remains size-dependent for some tumour types. The consequent stage assignment can significantly influence treatment intensity. Still, the protocols tend not to give precise guidance on how to perform scans and standardise measurements. Also, they do not estimate or account for the inevitable variability in measurements. Counts and measurements of lung nodules are, within some tumour groups, used for diagnosis of metastatic disease. There is, however, no evidence that nodule size is a useful discriminator of benign and malignant lung nodules. The efficacy of imaging depends chiefly on observations being precise, accurate and valid for the desired diagnostic purpose. Because measurements without estimates of their errors are meaningless, studies of variability dependent on tumour shape and location, imaging device and observer need to be encouraged. Reproducible observations make good candidates for staging parameters if they have prognostic validity and at the same time show little covariation with (thereby adding new information to) the existing staging system. The lack of scientific rigour has made the validity of size measurement very difficult to assess. Action is needed, the most important being radiologists' active contribution in development of oncological staging systems, attention to standardisation, knowledge about errors in measurement and protection against undue influence of such errors in the staging of the individual child.

  2. Sensorimotor System Measurement Techniques

    PubMed Central

    Riemann, Bryan L.; Myers, Joseph B.; Lephart, Scott M.

    2002-01-01

    Objective: To provide an overview of currently available sensorimotor assessment techniques. Data Sources: We drew information from an extensive review of the scientific literature conducted in the areas of proprioception, neuromuscular control, and motor control measurement. Literature searches were conducted using MEDLINE for the years 1965 to 1999 with the key words proprioception, somatosensory evoked potentials, nerve conduction testing, electromyography, muscle dynamometry, isometric, isokinetic, kinetic, kinematic, posture, equilibrium, balance, stiffness, neuromuscular, sensorimotor, and measurement. Additional sources were collected using the reference lists of identified articles. Data Synthesis: Sensorimotor measurement techniques are discussed with reference to the underlying physiologic mechanisms, influential factors and locations of the variable within the system, clinical research questions, limitations of the measurement technique, and directions for future research. Conclusions/Recommendations: The complex interactions and relationships among the individual components of the sensorimotor system make measuring and analyzing specific characteristics and functions difficult. Additionally, the specific assessment techniques used to measure a variable can influence attained results. Optimizing the application of sensorimotor research to clinical settings can, therefore, be best accomplished through the use of common nomenclature to describe underlying physiologic mechanisms and specific measurement techniques. PMID:16558672

  3. Tunable acousto-optic spectral imager for atmospheric composition measurements in the visible spectral domain.

    PubMed

    Dekemper, Emmanuel; Loodts, Nicolas; Van Opstal, Bert; Maes, Jeroen; Vanhellemont, Filip; Mateshvili, Nina; Franssens, Ghislain; Pieroux, Didier; Bingen, Christine; Robert, Charles; De Vos, Lieve; Aballea, Ludovic; Fussen, Didier

    2012-09-01

    We describe a new spectral imaging instrument using a TeO(2) acousto-optical tunable filter (AOTF) operating in the visible domain (450-900 nm). It allows for fast (~1 second), monochromatic (FWHM ranges from 0.6 nm at 450 nm to 3.5 nm at 800 nm) picture acquisition with good spatial resolution. This instrument was designed as a breadboard of the visible channel of a new satellite-borne atmospheric limb spectral imager, named the Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere (ALTIUS), that is currently being developed. We tested its remote sensing capabilities by observing the dense, turbulent plume exhausted by a waste incinerator stack at two wavelengths sensitive to NO(2). An average value of 6.0±0.4×10(17) molecules cm(-2) has been obtained for the NO(2) slant column density within the plume, close to the stack outlet. Although this result was obtained with a rather low accuracy, it demonstrates the potential of spectral imaging by using AOTFs in remote sensing.

  4. Measuring Temperature Reading

    NASA Technical Reports Server (NTRS)

    2003-01-01

    There are two requirements for taking a measurement of something. The first is a tool for taking a measurement. The second is scale for making sense of the numbers of the measurement. For example, a ruler is often used to measure short lengths. It is the tool for measurement. On the ruler are one or more number scales with equally spaced numbers. These numbers can be compared with numbers from any other ruler that is accurately set to the same scale. Measuring length is far simpler than measuring temperature. While there is evidence of tools for measuring length at various times in human history, tools and scales for measuring temperature do not appear until more recent human history. Early thermometers, called thermoscopes, first appear in the 1500's. They were crude instruments that were not at all accurate. Most did not even have a number scale associated with them. This made them useless for most practical purposes. Gabriel Fahrenheit created the first accurate thermometer in 1714, and the Fahrenheit temperature scale followed it in 1724. The thermometer s accuracy was based on its use of mercury, a silver colored substance that remains liquid over a wide range of temperatures but expands or contracts in a standard, predictable way with changes in temperature. To set the scale, Fahrenheit created the coldest temperature that he could. He mixed equal parts of ice, water, and salt, and then used this as the zero point, 0 degrees, of his scale. He intended to make 30 degrees the freezing point of water and 90 degrees the temperature of the human body, but he had to later revise these temperatures to be 32 degrees and 96 degrees. In the final version of the scale, the temperature of the human body became 98.6 degrees. 19th century thermoscope

  5. Measuring Temperature Reading

    NASA Technical Reports Server (NTRS)

    2003-01-01

    There are two requirements for taking a measurement of something. The first is a tool for taking a measurement. The second is scale for making sense of the numbers of the measurement. For example, a ruler is often used to measure short lengths. It is the tool for measurement. On the ruler are one or more number scales with equally spaced numbers. These numbers can be compared with numbers from any other ruler that is accurately set to the same scale. Measuring length is far simpler than measuring temperature. While there is evidence of tools for measuring length at various times in human history, tools and scales for measuring temperature do not appear until more recent human history. Early thermometers, called thermoscopes, first appear in the 1500's. They were crude instruments that were not at all accurate. Most did not even have a number scale associated with them. This made them useless for most practical purposes. Gabriel Fahrenheit created the first accurate thermometer in 1714, and the Fahrenheit temperature scale followed it in 1724. The thermometer s accuracy was based on its use of mercury, a silver colored substance that remains liquid over a wide range of temperatures but expands or contracts in a standard, predictable way with changes in temperature. To set the scale, Fahrenheit created the coldest temperature that he could. He mixed equal parts of ice, water, and salt, and then used this as the zero point, 0 degrees, of his scale. He intended to make 30 degrees the freezing point of water and 90 degrees the temperature of the human body, but he had to later revise these temperatures to be 32 degrees and 96 degrees. In the final version of the scale, the temperature of the human body became 98.6 degrees. 19th century thermoscope

  6. RF impedance measurement calibration

    SciTech Connect

    Matthews, P.J.; Song, J.J.

    1993-02-12

    The intent of this note is not to explain all of the available calibration methods in detail. Instead, we will focus on the calibration methods of interest for RF impedance coupling measurements and attempt to explain: (1). The standards and measurements necessary for the various calibration techniques. (2). The advantages and disadvantages of each technique. (3). The mathematical manipulations that need to be applied to the measured standards and devices. (4). An outline of the steps needed for writing a calibration routine that operated from a remote computer. For further details of the various techniques presented in this note, the reader should consult the references.

  7. QCD Measurements at ATLAS

    NASA Astrophysics Data System (ADS)

    Hubacek, Z.; Atlas Collaboration

    2017-07-01

    This paper presents recent QCD related measurements from the ATLAS Experiment at the LHC at CERN. The results on the total inelastic cross-section, charged particle production, jet production, photon production, and W -, Z -bosons productions are briefly summarized. The measurments are performed at different center-of-mass energies √{s}=7, 8, and 13 TeV . The measured cross-sections are generally found to be in agreement with the expectations from the Standard Model within the estimated uncertainties.

  8. CIRCUITS FOR CURRENT MEASUREMENTS

    DOEpatents

    Cox, R.J.

    1958-11-01

    Circuits are presented for measurement of a logarithmic scale of current flowing in a high impedance. In one form of the invention the disclosed circuit is in combination with an ionization chamber to measure lonization current. The particular circuit arrangement lncludes a vacuum tube having at least one grid, an ionization chamber connected in series with a high voltage source and the grid of the vacuum tube, and a d-c amplifier feedback circuit. As the ionization chamber current passes between the grid and cathode of the tube, the feedback circuit acts to stabilize the anode current, and the feedback voltage is a measure of the logaritbm of the ionization current.

  9. Wireless Acoustic Measurement System

    NASA Technical Reports Server (NTRS)

    Anderson, Paul D.; Dorland, Wade D.

    2005-01-01

    A prototype wireless acoustic measurement system (WAMS) is one of two main subsystems of the Acoustic Prediction/Measurement Tool, which comprises software, acoustic instrumentation, and electronic hardware combined to afford integrated capabilities for predicting and measuring noise emitted by rocket and jet engines. The other main subsystem is described in "Predicting Rocket or Jet Noise in Real Time" (SSC-00215-1), which appears elsewhere in this issue of NASA Tech Briefs. The WAMS includes analog acoustic measurement instrumentation and analog and digital electronic circuitry combined with computer wireless local-area networking to enable (1) measurement of sound-pressure levels at multiple locations in the sound field of an engine under test and (2) recording and processing of the measurement data. At each field location, the measurements are taken by a portable unit, denoted a field station. There are ten field stations, each of which can take two channels of measurements. Each field station is equipped with two instrumentation microphones, a micro-ATX computer, a wireless network adapter, an environmental enclosure, a directional radio antenna, and a battery power supply. The environmental enclosure shields the computer from weather and from extreme acoustically induced vibrations. The power supply is based on a marine-service lead-acid storage battery that has enough capacity to support operation for as long as 10 hours. A desktop computer serves as a control server for the WAMS. The server is connected to a wireless router for communication with the field stations via a wireless local-area network that complies with wireless-network standard 802.11b of the Institute of Electrical and Electronics Engineers. The router and the wireless network adapters are controlled by use of Linux-compatible driver software. The server runs custom Linux software for synchronizing the recording of measurement data in the field stations. The software includes a module that

  10. Mirror Measurement Device

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A Small Business Innovation Research (SBIR) contract led to a commercially available instrument used to measure the shape profile of mirror surfaces in scientific instruments. Bauer Associates, Inc.'s Bauer Model 200 Profilometer is based upon a different measurement concept. The local curvature of the mirror's surface is measured at many points, and the collection of data is computer processed to yield the desired shape profile. (Earlier profilometers are based on the principle of interferometry.) The system is accurate and immune to problems like vibration and turbulence. Two profilometers are currently marketed, and a third will soon be commercialized.

  11. Remote air pollution measurement

    NASA Technical Reports Server (NTRS)

    Byer, R. L.

    1975-01-01

    This paper presents a discussion and comparison of the Raman method, the resonance and fluorescence backscatter method, long path absorption methods and the differential absorption method for remote air pollution measurement. A comparison of the above remote detection methods shows that the absorption methods offer the most sensitivity at the least required transmitted energy. Topographical absorption provides the advantage of a single ended measurement, and differential absorption offers the additional advantage of a fully depth resolved absorption measurement. Recent experimental results confirming the range and sensitivity of the methods are presented.

  12. Mining volume measurement system

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph Saul (Inventor)

    1988-01-01

    In a shaft with a curved or straight primary segment and smaller off-shooting segments, at least one standing wave is generated in the primary segment. The shaft has either an open end or a closed end and approximates a cylindrical waveguide. A frequency of a standing wave that represents the fundamental mode characteristic of the primary segment can be measured. Alternatively, a frequency differential between two successive harmonic modes that are characteristic of the primary segment can be measured. In either event, the measured frequency or frequency differential is characteristic of the length and thus the volume of the shaft based on length times the bore area.

  13. Measuring Thermodynamic Length

    SciTech Connect

    Crooks, Gavin E

    2007-09-07

    Thermodynamic length is a metric distance between equilibrium thermodynamic states. Among other interesting properties, this metric asymptotically bounds the dissipation induced by a finite time transformation of a thermodynamic system. It is also connected to the Jensen-Shannon divergence, Fisher information, and Rao's entropy differential metric. Therefore, thermodynamic length is of central interestin understanding matter out of equilibrium. In this Letter, we will consider how to denethermodynamic length for a small system described by equilibrium statistical mechanics and how to measure thermodynamic length within a computer simulation. Surprisingly, Bennett's classic acceptance ratio method for measuring free energy differences also measures thermodynamic length.

  14. Performance measures, efficiency, productivity.

    PubMed

    Mukundan, Govind; Seidenwurm, David

    2012-08-01

    The paradox of the increased use of imaging without obvious evidence of improved health outcomes has led to calls for payment based on value rather than volume. Measurement of radiologists' performance is a key component of the measurement of value. The paradigm shift occurring in radiology and health care as a whole may seem daunting to the radiologist with the clamor for increasing accountability from payers and patients alike. However, it is through powerful tools such as performance measures in radiology and their accompanying incentive-based payment systems that practices can be improved and confidence of patients restored. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Ultrasonic linear measurement system

    NASA Technical Reports Server (NTRS)

    Marshall, Scot H. (Inventor)

    1991-01-01

    An ultrasonic linear measurement system uses the travel time of surface waves along the perimeter of a three-dimensional curvilinear body to determine the perimeter of the curvilinear body. The system can also be used piece-wise to measure distances along plane surfaces. The system can be used to measure perimeters where use of laser light, optical means or steel tape would be extremely difficult, time consuming or impossible. It can also be used to determine discontinuities in surfaces of known perimeter or dimension.

  16. Measuring Nursing Care Value.

    PubMed

    Welton, John M; Harper, Ellen M

    2016-01-01

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

  17. Precision volume measurement system.

    SciTech Connect

    Fischer, Erin E.; Shugard, Andrew D.

    2004-11-01

    A new precision volume measurement system based on a Kansas City Plant (KCP) design was built to support the volume measurement needs of the Gas Transfer Systems (GTS) department at Sandia National Labs (SNL) in California. An engineering study was undertaken to verify or refute KCP's claims of 0.5% accuracy. The study assesses the accuracy and precision of the system. The system uses the ideal gas law and precise pressure measurements (of low-pressure helium) in a temperature and computer controlled environment to ratio a known volume to an unknown volume.

  18. Biomagnetic instrumentation and measurement

    NASA Technical Reports Server (NTRS)

    Iufer, E. J.

    1978-01-01

    The instruments and techniques of biomagnetic measurement have progressed greatly in the past 15 years and are now of a quality appropriate to clinical applications. The paper reports on recent developments in the design and application of SQUID (Superconducting Quantum Interference Device) magnetometers to biomagnetic measurement. The discussion covers biomagnetic field levels, magnetocardiography, magnetic susceptibility plethysmography, ambient noise and sensor types, principles of operation of a SQUID magnetometer, and laboratory techniques. Of the many promising applications of noninvasive biomagnetic measurement, magnetocardiography is the most advanced and the most likely to find clinical application in the near future.

  19. METHOD FOR MEASURING RADIATION

    DOEpatents

    Roesch, W.C.; McCall, R.C.

    1961-11-21

    A method for measuring an unknown integrated quantity of radiation with a condenser ionization chamber is described. The chamber is initially charged to a predetermined voltage by a voltage source. The chamber is then removed from the source and exposed to an unknown quantity of radiation for a period of time. The quantity of radiation to which the chamber was exposed is then measured by detecting the magnitude of the pulse of current necessary to recharge the chamber of its initial value through a suitable impedance. The current pulse is amplified and measured directly by a suitable pulse height analyzing system. (AEC)

  20. Wireless Acoustic Measurement System

    NASA Technical Reports Server (NTRS)

    Anderson, Paul D.; Dorland, Wade D.; Jolly, Ronald L.

    2007-01-01

    A prototype wireless acoustic measurement system (WAMS) is one of two main subsystems of the Acoustic Prediction/ Measurement Tool, which comprises software, acoustic instrumentation, and electronic hardware combined to afford integrated capabilities for predicting and measuring noise emitted by rocket and jet engines. The other main subsystem is described in the article on page 8. The WAMS includes analog acoustic measurement instrumentation and analog and digital electronic circuitry combined with computer wireless local-area networking to enable (1) measurement of sound-pressure levels at multiple locations in the sound field of an engine under test and (2) recording and processing of the measurement data. At each field location, the measurements are taken by a portable unit, denoted a field station. There are ten field stations, each of which can take two channels of measurements. Each field station is equipped with two instrumentation microphones, a micro- ATX computer, a wireless network adapter, an environmental enclosure, a directional radio antenna, and a battery power supply. The environmental enclosure shields the computer from weather and from extreme acoustically induced vibrations. The power supply is based on a marine-service lead-acid storage battery that has enough capacity to support operation for as long as 10 hours. A desktop computer serves as a control server for the WAMS. The server is connected to a wireless router for communication with the field stations via a wireless local-area network that complies with wireless-network standard 802.11b of the Institute of Electrical and Electronics Engineers. The router and the wireless network adapters are controlled by use of Linux-compatible driver software. The server runs custom Linux software for synchronizing the recording of measurement data in the field stations. The software includes a module that provides an intuitive graphical user interface through which an operator at the control server

  1. Measuring Building Insulation

    NASA Astrophysics Data System (ADS)

    Parks, Beth

    2013-03-01

    Currently, the only way for homeowners to learn about the effectiveness of their home insulation is to hire an energy auditor. This difficulty deters homeowners from taking action to improve energy efficiency. In principle, measuring the temperature difference between a wall surface and the interior of a home is sufficient to determine the wall insulation, but in practice, temperature cycles from the heating system make a single measurement unreliable. I will describe a simple and inexpensive thermocouple-based device to measure this temperature difference and report results obtained by monitoring this temperature difference over multiple heating cycles in a range of buildings. Patent application 12/555371

  2. Remote air pollution measurement

    NASA Technical Reports Server (NTRS)

    Byer, R. L.

    1975-01-01

    This paper presents a discussion and comparison of the Raman method, the resonance and fluorescence backscatter method, long path absorption methods and the differential absorption method for remote air pollution measurement. A comparison of the above remote detection methods shows that the absorption methods offer the most sensitivity at the least required transmitted energy. Topographical absorption provides the advantage of a single ended measurement, and differential absorption offers the additional advantage of a fully depth resolved absorption measurement. Recent experimental results confirming the range and sensitivity of the methods are presented.

  3. Measurement of androgens.

    PubMed

    Wheeler, Michael J

    2006-01-01

    Testosterone is the major androgen measured in clinical and research investigations of both men and women. Nevertheless, many other androgens have an important role in the investigation of andrenal and gonadal physiology and pathology. Commercial assays are generally used in clinical laboratories but these have poor precision at low concentrations and poor sensitivity. Extraction assays, described in this chapter, can be much more sensitive and precise. There is interest in measuring free steriods and a steady-state gel filtration method used in the author's laboratory is described. Methods are also provided for the measurement of steroids in saliva and hair.

  4. Modal phase measuring deflectometry

    SciTech Connect

    Huang, Lei; Xue, Junpeng; Gao, Bo; McPherson, Chris; Beverage, Jacob; Idir, Mourad

    2016-10-14

    Here in this work, a model based method is applied to phase measuring deflectometry, which is named as modal phase measuring deflectometry. The height and slopes of the surface under test are represented by mathematical models and updated by optimizing the model coefficients to minimize the discrepancy between the reprojection in ray tracing and the actual measurement. The pose of the screen relative to the camera is pre-calibrated and further optimized together with the shape coefficients of the surface under test. Simulations and experiments are conducted to demonstrate the feasibility of the proposed approach.

  5. Offset Waveguide Transmission Measurements

    NASA Technical Reports Server (NTRS)

    Cravey, Robin

    1997-01-01

    This report describes measurements to determine transmission losses in S-band (2.60-3.95 GHz) waveguide sections due to misalignment of the sections relative to each other. The experiments were performed in support of the Hydrostar program to determine the feasibility of using deployable waveguide sections in a large space radiometer. The waveguide sections would possibly be hinged and folded for launch, then deployed in space to form long sections of waveguide. Since very low losses are required for radiometer applications, the effects of potential misalignment after deployment of the waveguide sections may be significant. These measurements were performed in the Electromagnetic Properties Measurement Laboratory in the Electromagnetics Research Branch.

  6. Mathematics and Measurement

    PubMed Central

    Boisvert, Ronald F.; Donahue, Michael J.; Lozier, Daniel W.; McMichael, Robert; Rust, Bert W.

    2001-01-01

    In this paper we describe the role that mathematics plays in measurement science at NIST. We first survey the history behind NIST’s current work in this area, starting with the NBS Math Tables project of the 1930s. We then provide examples of more recent efforts in the application of mathematics to measurement science, including the solution of ill-posed inverse problems, characterization of the accuracy of software for micromagnetic modeling, and in the development and dissemination of mathematical reference data. Finally, we comment on emerging issues in measurement science to which mathematicians will devote their energies in coming years. PMID:27500024

  7. Spectroelectrochemical Instrument Measures TOC

    NASA Technical Reports Server (NTRS)

    Kounaves, Sam

    2011-01-01

    A spectroelectrochemical instrument has been developed for measuring the total organic carbon (TOC) content of an aqueous solution. Measurements of TOC are frequently performed in environmental, clinical, and industrial settings. Until now, techniques for performing such measurements have included, various ly, the use of hazardous reagents, ultraviolet light, or ovens, to promote reactions in which the carbon contents are oxidized. The instrument now being developed is intended to be a safer, more economical means of oxidizing organic carbon and determining the TOC levels of aqueous solutions and for providing a low power/mass unit for use in planetary missions.

  8. Near-threshold femtosecond laser fabrication of one-dimensional subwavelength nanogratings on a graphite surface

    NASA Astrophysics Data System (ADS)

    Golosov, E. V.; Ionin, A. A.; Kolobov, Yu. R.; Kudryashov, S. I.; Ligachev, A. E.; Makarov, S. V.; Novoselov, Yu. N.; Seleznev, L. V.; Sinitsyn, D. V.; Sharipov, A. R.

    2011-03-01

    Superimposed one-dimensional quasiperiodic gratings with multiple periods Λ ≈ 110-800 nm well below or comparable to the pump laser wavelength of 744 nm, and ridge orientations perpendicular to the linear polarization of infrared femtosecond laser pulses, were fabricated after multiple near-threshold laser shots on a planar surface of quasimonocrystalline graphite in ambient air. The broad range of the grating periods corresponds to the large number of spatial Fourier harmonics of the final nanorelief (up to m=7th order, Λm≈800 nm/m=110-800 nm), qualitatively representing the nonsinusoidal profile of the laser-induced intermediate surface relief (the set of periodic, broadly spaced narrow nanotrenches), which provides the corresponding multiangle diffraction of the incident femtosecond laser pulses. Experimental measurements and modeling of the transient optical constants of the photoexcited graphite justify the excitation, at the first stage, of the first-order (Λ1≈800 nm) surface plasmon-polaritonic (SPP) wave on the photo-excited initial planar graphite surface becoming metallic via photo-generation of dense electron hole plasma (˜1021 cm-3). Such an SPP wave provides intermediate nanorelief in the form of the nonsinusoidal surface grating via its interference with the incident laser wave, resulting under near-threshold laser irradiation conditions in the highly localized surface ablation of the material in the interference maxima. During the next stage, the multiperiod subwavelength nanogratings develop through the multiangle diffraction of the multiple incident laser pulses on the intermediate nonsinusoidal surface grating.

  9. Measuring body temperature.

    PubMed

    McCallum, Louise; Higgins, Dan

    Body temperature is one of the four main vital signs that must be monitored to ensure safe and effective care. Temperature measurement is recommended by the National Institute of Clinical Excellence a part of the initial assessment in acute illness in adults (NICE, 2007) and by the Scottish Intercollegiate Guidelines Network guidelines for post-operative management in adults (SIGN, 2004). Despite applying in all healthcare environments, wide variations exist on the methods and techniques used to measure body temperature. It is essential to use the most appropriate technique to ensure that temperature is measured accurately. Inaccurate results may influence diagnosis and treatment, lead to a failure to identify patient deterioration and compromise patient safety. This article explains the importance of temperature regulation and compares methods of its measurement.

  10. Measuring Job Security.

    ERIC Educational Resources Information Center

    Nardone, Thomas; And Others

    1997-01-01

    Discusses issues in measuring job security and presents a comparison of data from the National Longitudinal Survey of Youth and the Current Population Survey on job tenure and contingent employment. (SK)

  11. Earth Radiation Measurement Science

    NASA Technical Reports Server (NTRS)

    Smith, G. Louis

    2000-01-01

    This document is the final report for NASA Grant NAG1-1959, 'Earth Radiation Measurement Science'. The purpose of this grant was to perform research in this area for the needs of the Clouds and Earth Radiant Energy System (CERES) project and for the Earth Radiation Budget Experiment (ERBE), which are bing conducted by the Radiation and Aerosols Branch of the Atmospheric Sciences Division of Langley Research Center. Earth Radiation Measurement Science investigates the processes by which measurements are converted into data products. Under this grant, research was to be conducted for five tasks: (1) Point Response Function Measurements; (2) Temporal Sampling of Outgoing Longwave Radiation; (3) Spatial Averaging of Radiation Budget Data; (4) CERES Data Validation and Applications; and (5) ScaRaB Data Validation and Application.

  12. Terrestrial photovoltaic measurements, 2

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The following major topics are discussed; (1) Terrestrial solar irradiance; (2) Solar simulation and reference cell calibration; and (3) Cell and array measurement procedures. Numerous related subtopics are also discussed within each major topic area.

  13. Realizations of Measurement.

    ERIC Educational Resources Information Center

    Wright, Benjamin D.

    2000-01-01

    Uses the analogy of squeezing two glasses of orange juice from 4 pounds of oranges, no matter how many oranges constitute 4 pounds, to illustrate the distinction between art and science, as between counting right answers and constructing measures. (SLD)

  14. Topography measurements and applications

    NASA Astrophysics Data System (ADS)

    Song, Junfeng; Vorburger, Theodore

    2006-11-01

    Based on auto- and cross-correlation functions (ACF and CCF), a new surface parameter called profile (or topography) difference, D s, has been developed for quantifying differences between 2D profiles or between 3D topographies with a single number. When D s = 0, the two compared 2D profiles or 3D topographies must be exactly the same (point by point). A 2D and 3D topography measurement system was established at NIST. This system includes data acquisition stations using a stylus instrument and a confocal microscope, and a correlation program using the proposed parameters D s and the cross-correlation function maximum CCF max. Applications in forensic science and surface metrology are described; those include profile signature measurements for 40 NIST Standard Reference Material (SRM) 2460 standard bullets, and comparisons of profile measurements with four different techniques. An approach to optimizing the Gaussian filter long wavelength cutoff, λc, is proposed for topography measurements.

  15. Measuring Strong Nanostructures

    ScienceCinema

    Andy Minor

    2016-07-12

    Andy Minor of Berkeley Lab's National Center for Electron Microscopy explains measuring stress and strain on nanostructures with the In Situ Microscope. More information: http://newscenter.lbl.gov/press-relea...

  16. Measuring Salinity by Conductivity.

    ERIC Educational Resources Information Center

    Lapworth, C. J.

    1981-01-01

    Outlines procedures for constructing an instrument which uses an electrode and calibration methods to measure the salinity of waters in environments close to and affected by a saline estuary. (Author/DC)

  17. Measuring Your Fitness Level

    MedlinePlus

    ... key areas: aerobic fitness, muscular strength and endurance, flexibility, and body composition. To do your assessment, you' ... test is a simple way to measure the flexibility of the back of your legs, hips and ...

  18. Measuring Relative Humidity.

    ERIC Educational Resources Information Center

    Pinkham, Chester A.; Barrett, Kristin Burrows

    1992-01-01

    Describes four experiments that enable students to explore the phenomena of evaporation and condensation and determine the relative humidity by measuring air temperature and dew point on warm September days. Provides tables to calculate saturation points and relative humidity. (MDH)

  19. Future GPD Measurements

    SciTech Connect

    Kaiser, Ralf

    2009-08-04

    Generalised Parton Distributions (GPDs) have grown into one of the main topics in hadron physics. They are playing a central role in the physics of the JLab 12 GeV upgrade as well as in the future physics programme of the COMPASS experiment at CERN. This paper explores the future of GPD measurements in the short, medium and long term. The short term includes the analysis of already existing data from HERMES and JLab and planned measurements at JLab before the 12 GeV upgrade. In the medium term this concerns the JLab programme after the upgrade, measurements at COMPASS and at PANDA/FAIR. The EIC project or possible alternatives form the long term perspective. The main focus of the considerations lies on DVCS measurements and related experiments.

  20. In situ measurement system

    DOEpatents

    Lord, D.E.

    1980-11-24

    A multipurpose in situ underground measurement system comprising a plurality of long electrical resistance elements in the form of rigid reinforcing bars, each having an open loop hairpin configuration of shorter length than the other resistance elements. The resistance elements are arranged in pairs in a unitized structure, and grouted in place in the underground volume. Measurement means are provided for obtaining for each pair the electrical resistance of each element and the difference in electrical resistance of the paired elements, which difference values may be used in analytical methods involving resistance as a function of temperature. A scanner means sequentially connects the resistance-measuring apparatus to each individual pair of elements. A source of heating current is also selectively connectable for heating the elements to an initial predetermined temperature prior to electrical resistance measurements when used as an anemometer.

  1. Dilepton Measurements with CERES

    SciTech Connect

    Marin,A.; Rehak, P. et al.

    2007-07-09

    We report on dilepton measurements for central Pb on Au collisions at the top CERN SPS energy with the upgraded CERES experiment. The dilepton mass spectrum of 2000 data with improved mass resolution shows an enhancement over the expectation from hadron decays that is well described by a model including a strong broadening of the {rho} spectral function. The measured excess yield excludes the dropping mass scenario. We also report on the {phi} meson measured simultaneously both in the K{sup +}K{sup -} and in the dilepton decay channel for the first time in high energy heavy-ion collisions. An excellent agreement is found between the rapidity densities and the shape of the measured transverse momentum spectrum. The data rule out a possible enhancement of the {phi} yield in the leptonic over hadronic channel by a factor larger than 1.6 at 95% CL. CERES results are in agreement with NA49 results.

  2. CHAPTER ONE: EXPOSURE MEASUREMENTS.

    EPA Science Inventory

    Determining human exposure to suspended particualte concentrations requires measurements that quantify different particle properties in microenvironments where people live, work, and play. Particle mass, size, and chemical composition are important exposure variables, and these ...

  3. Measuring Physical Activity Intensity

    MedlinePlus

    ... Life Activities for Children Activities for Older Adults Overcoming Barriers Measuring Physical Activity Intensity Target Heart Rate & ... DFCN Promotion Implementation Maintaining Interest Needs Assessment Evaluating Success CDC’s Example StairWELL Stairwell Appearance Motivational Signs Installing ...

  4. Measuring coal thickness

    NASA Technical Reports Server (NTRS)

    Barker, C.; Blaine, J.; Geller, G.; Robinson, R.; Summers, D.; Tyler, J.

    1980-01-01

    Laboratory tested concept, for measuring thickness of overhead coal using noncontacting sensor system coupled to controller and high pressure water jet, allows mining machines to remove virtually all coal from mine roofs without danger of cutting into overlying rock.

  5. Measuring projectile speed

    NASA Technical Reports Server (NTRS)

    Jordan, J. E.; Kassel, P. C., Jr.

    1979-01-01

    Apparatus uses optoelectric detector to measure station-to-station time-of-flight of small spherical aluminum projectile down steel barrel. Instrument has been used to study impact resistance of composite materials used in aircraft structural research program.

  6. Measuring Job Security.

    ERIC Educational Resources Information Center

    Nardone, Thomas; And Others

    1997-01-01

    Discusses issues in measuring job security and presents a comparison of data from the National Longitudinal Survey of Youth and the Current Population Survey on job tenure and contingent employment. (SK)

  7. Measuring Strong Nanostructures

    SciTech Connect

    Andy Minor

    2008-10-16

    Andy Minor of Berkeley Lab's National Center for Electron Microscopy explains measuring stress and strain on nanostructures with the In Situ Microscope. More information: http://newscenter.lbl.gov/press-relea...

  8. Measuring Relative Humidity.

    ERIC Educational Resources Information Center

    Pinkham, Chester A.; Barrett, Kristin Burrows

    1992-01-01

    Describes four experiments that enable students to explore the phenomena of evaporation and condensation and determine the relative humidity by measuring air temperature and dew point on warm September days. Provides tables to calculate saturation points and relative humidity. (MDH)

  9. Measuring Salinity by Conductivity.

    ERIC Educational Resources Information Center

    Lapworth, C. J.

    1981-01-01

    Outlines procedures for constructing an instrument which uses an electrode and calibration methods to measure the salinity of waters in environments close to and affected by a saline estuary. (Author/DC)

  10. The Measurement of Wettability

    ERIC Educational Resources Information Center

    Pirie, Brian J. S.; Gregory, David W.

    1973-01-01

    Discusses the use of a simple apparatus to measure contact angles between a liquid drop and a solid surface which are determining factors of wettability. Included are examples of applying this technique to various experimental situations. (CC)

  11. Quality measures for neurologists

    PubMed Central

    Sanders, Amy E.; Swain-Eng, Rebecca J.; Gjorvad, Gina; Tonn, Sarah T.; Bever, Christopher T.; Cheng, Eric M.

    2013-01-01

    Summary Measuring and reporting health care quality is increasingly becoming part of clinical practice and reimbursement for specialists, including neurologists. The goal is to improve the value of care. Current major programs tie quality measurements to reimbursement, including programs from the Centers for Medicare and Medicaid Services: the Physician Quality Reporting System, the Electronic Health Record Incentive Program (and Meaningful Use), and Accountable Care Organizations. Many specialty boards, including the American Board of Psychiatry and Neurology, now require clinical practice quality measurements for maintenance of certification. Practitioners may find these programs confusing, overlapping, burdensome, and not clearly relevant to promoting better patient care. Yet, integrating quality metrics into practice has entered the mainstream and is increasingly tied to reimbursement. Further, over the next few years, most programs will switch from bonus incentives for participation to penalties for nonparticipation. This article aims to clarify current and rising quality measurement programs relevant to neurologists. PMID:23634383

  12. CHAPTER ONE: EXPOSURE MEASUREMENTS.

    EPA Science Inventory

    Determining human exposure to suspended particualte concentrations requires measurements that quantify different particle properties in microenvironments where people live, work, and play. Particle mass, size, and chemical composition are important exposure variables, and these ...

  13. Fission Measurements with Dance

    NASA Astrophysics Data System (ADS)

    Jandel, M.; Bredeweg, T. A.; Fowler, M. M.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Keksis, A. L.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Dashdorj, D.; Macri, R. A.; Parker, W. E.; Wilk, P. A.; Wu, C. Y.; Becker, J. A.; Angell, C. T.; Tonchev, A. P.; Baker, J. D.

    2008-08-01

    Neutron capture cross section measurements on actinides are complicated by the presence of neutron-induced fission. An efficient fission tagging detector used in coincidence with the Detector for Advanced Neutron Capture Experiments (DANCE) provides a powerful tool in undertaking simultaneous measurements of (n,γ) and (n,f) cross sections. Preliminary results on 235U(n,γ) and (n,f) and 242mAm(n,f) cross sections measured with DANCE and a custom fission-tagging parallel plate avalanche counter (PPAC) are presented. Additional measurements of γ-ray cluster multiplicity distributions for neutron-induced fission of 235U and 242mAm and spontaneous fission of 252Cf are shown, as well as γ-ray energy and average γ-ray energy distributions.

  14. Measuring Aspects of Morality

    ERIC Educational Resources Information Center

    Ziv, Avner

    1976-01-01

    A group test measuring five aspects of morality in children is presented. The aspects are: resistance to temptation, stage of moral judgment, confession after transgression, reaction of fear or guilt, and severity of punishment for transgression. (Editor)

  15. Measurement of endolymphatic pressure.

    PubMed

    Mom, T; Pavier, Y; Giraudet, F; Gilain, L; Avan, P

    2015-04-01

    Endolymphatic pressure measurement is of interest both to researchers in the physiology and pathophysiology of hearing and ENT physicians dealing with Menière's disease or similar conditions. It is generally agreed that endolymphatic hydrops is associated with Menière's disease and is accompanied by increased hydrostatic pressure. Endolymphatic pressure, however, cannot be measured precisely without endangering hearing, making the association between hydrops and increased endolymphatic pressure difficult to demonstrate. Several integrated in vivo models have been developed since the 1960s, but only a few allow measurement of endolymphatic hydrostatic pressure. Models associating measurement of hydrostatic pressure and endolymphatic potential and assessment of cochlear function are of value to elucidate the pathophysiology of endolymphatic hydrops. The present article presents the main types of models and discusses their respective interest.

  16. Capacitance measuring device

    DOEpatents

    Andrews, W.H. Jr.

    1984-08-01

    A capacitance measuring circuit is provided in which an unknown capacitance is measured by comparing the charge stored in the unknown capacitor with that stored in a known capacitance. Equal and opposite voltages are repetitively simultaneously switched onto the capacitors through an electronic switch driven by a pulse generator to charge the capacitors during the ''on'' portion of the cycle. The stored charge is compared by summing discharge currents flowing through matched resistors at the input of a current sensor during the ''off'' portion of the switching cycle. The net current measured is thus proportional to the difference in value of the two capacitances. The circuit is capable of providing much needed accuracy and stability to a great variety of capacitance-based measurement devices at a relatively low cost.

  17. Force measurements on airplanes

    NASA Technical Reports Server (NTRS)

    Seewald, F

    1929-01-01

    The most essential phenomena of aircraft should be classified according to their origin and then measured. Information can thus be obtained in a quicker, cheaper, and more reliable way than otherwise would be possible.

  18. Realizations of Measurement.

    ERIC Educational Resources Information Center

    Wright, Benjamin D.

    2000-01-01

    Uses the analogy of squeezing two glasses of orange juice from 4 pounds of oranges, no matter how many oranges constitute 4 pounds, to illustrate the distinction between art and science, as between counting right answers and constructing measures. (SLD)

  19. Advance Control Measures & Programs

    EPA Pesticide Factsheets

    As areas develop their path forward or action plan, they should consider a variety of voluntary and mandatory measures and programs. The resources on this page can help, and participants are also encouraged to talk with their EPA Advance contact

  20. Neutron Lifetime Measurements

    NASA Astrophysics Data System (ADS)

    Nico, J. S.

    2006-11-01

    Precision measurements of neutron beta decay address basic questions in nuclear and particle physics, astrophysics, and cosmology. As the simplest semileptonic decay system, the free neutron plays an important role in understanding the physics of the weak interaction, and improving the precision of the neutron lifetime is fundamental to testing the validity of the theory. The neutron lifetime also directly affects the relative abundance of primordial helium in big bang nucleosynthesis. There are two distinct strategies for measuring the lifetime. Experiments using cold neutrons measure the absolute specific activity of a beam of neutrons by counting decay protons; experiments using confined, ultracold neutrons determine the lifetime by counting neutrons that remain after some elapsed time. The status of the recent lifetime measurements using both of these techniques is discussed.

  1. Neutron Lifetime Measurements

    SciTech Connect

    Nico, J. S.

    2006-11-17

    Precision measurements of neutron beta decay address basic questions in nuclear and particle physics, astrophysics, and cosmology. As the simplest semileptonic decay system, the free neutron plays an important role in understanding the physics of the weak interaction, and improving the precision of the neutron lifetime is fundamental to testing the validity of the theory. The neutron lifetime also directly affects the relative abundance of primordial helium in big bang nucleosynthesis. There are two distinct strategies for measuring the lifetime. Experiments using cold neutrons measure the absolute specific activity of a beam of neutrons by counting decay protons; experiments using confined, ultracold neutrons determine the lifetime by counting neutrons that remain after some elapsed time. The status of the recent lifetime measurements using both of these techniques is discussed.

  2. Photovoltaic spectral responsivity measurements

    SciTech Connect

    Emery, K.; Dunlavy, D.; Field, H.; Moriarty, T.

    1998-09-01

    This paper discusses the various elemental random and nonrandom error sources in typical spectral responsivity measurement systems. The authors focus specifically on the filter and grating monochrometer-based spectral responsivity measurement systems used by the Photovoltaic (PV) performance characterization team at NREL. A variety of subtle measurement errors can occur that arise from a finite photo-current response time, bandwidth of the monochromatic light, waveform of the monochromatic light, and spatial uniformity of the monochromatic and bias lights; the errors depend on the light source, PV technology, and measurement system. The quantum efficiency can be a function of he voltage bias, light bias level, and, for some structures, the spectral content of the bias light or location on the PV device. This paper compares the advantages and problems associated with semiconductor-detector-based calibrations and pyroelectric-detector-based calibrations. Different current-to-voltage conversion and ac photo-current detection strategies employed at NREL are compared and contrasted.

  3. Radiation Measurements on Mars

    NASA Image and Video Library

    2013-12-09

    Micrograys are unit of measurement for absorbed radiation dose. The vertical axis is in micrograys per day. The RAD instrument on NASA Curiosity Mars rover monitors the natural radiation environment at the surface of Mars.

  4. Geometric measures of entanglement

    SciTech Connect

    Uyanik, K.; Turgut, S.

    2010-03-15

    The geometric measure of entanglement, which expresses the minimum distance to product states, has been generalized to distances to sets that remain invariant under the stochastic reducibility relation. For each such set, an associated entanglement monotone can be defined. The explicit analytical forms of these measures are obtained for bipartite entangled states. Moreover, the three-qubit case is discussed and it is argued that the distance to the W states is a new monotone.

  5. GPS Measurement Of Attitude

    NASA Technical Reports Server (NTRS)

    Dinardo, S. J.; Hushbeck, E. L.; Meehan, T. K.; Munson, T. N.; Purcell, G. H.; Srinivasan, J. M.; Young, L. E.; Yunck, T. P.

    1992-01-01

    Signals transmitted by satellites of Global Positioning System (GPS) measure orientation of baseline on ship, aircraft, or other vehicle with accuracy. Two GPS antennas and receivers placed at well separated points on platform. Receivers measure positions of ends of baseline as functions of time. Output processor computes vector difference between two positions and determines orientation of baseline. Combined with conventional GPS data, orientation data allows more precise navigation and mapping and enhances calculations related to performance and control of vehicle.

  6. Device for calorimetric measurement

    DOEpatents

    King, William P; Lee, Jungchul

    2015-01-13

    In one aspect, provided herein is a single crystal silicon microcalorimeter, for example useful for high temperature operation and long-term stability of calorimetric measurements. Microcalorimeters described herein include microcalorimeter embodiments having a suspended structure and comprising single crystal silicon. Also provided herein are methods for making calorimetric measurements, for example, on small quantities of materials or for determining the energy content of combustible material having an unknown composition.

  7. Thermal coupling measurement method

    NASA Technical Reports Server (NTRS)

    Rosenthal, L. A.; Menichelli, V. J.

    1974-01-01

    Heat flow from an embedded heated wire responds to a change in the ambient environment. The wire is part of a self-balancing bridge system, and heat flow is measured directly in watts. Steady-state and transient thermal coupling can be measured directly and is an indication of the thermal resistance and diffusivity for the system under study. The method is applied to an aerospace electroexplosive component.

  8. Thermal coupling measurement method

    NASA Technical Reports Server (NTRS)

    Rosenthal, L. A.; Menichelli, V. J.

    1974-01-01

    Heat flow from an embedded heated wire responds to a change in the ambient environment. The wire is part of a self-balancing bridge system, and heat flow is measured directly in watts. Steady-state and transient thermal coupling can be measured directly and is an indication of the thermal resistance and diffusivity for the system under study. The method is applied to an aerospace electroexplosive component.

  9. Balloon film strain measurement

    NASA Technical Reports Server (NTRS)

    Rand, J. L.

    1983-01-01

    A discussion is presented of the results of a flight test program in which scientific research balloon material strain was measured in order to determine stress levels. Attention is given to material strain characteristics during the inflation, launch, ascent, and flight of a natural shape, zero-pressure scientific balloon. Measurements were conducted with a simple thin film strain transducer. Thermal, meridional and circumferential strain history data for the test flight are given.

  10. Oceanic wave measurement system

    NASA Technical Reports Server (NTRS)

    Holmes, J. F.; Miles, R. T. (Inventor)

    1980-01-01

    An oceanic wave measured system is disclosed wherein wave height is sensed by a barometer mounted on a buoy. The distance between the trough and crest of a wave is monitored by sequentially detecting positive and negative peaks of the output of the barometer and by combining (adding) each set of two successive half cycle peaks. The timing of this measurement is achieved by detecting the period of a half cycle of wave motion.

  11. Measurement of (124)I.

    PubMed

    Sahagia, M; Ioan, M-R; Antohe, A; Luca, A; Ivan, C

    2016-03-01

    The paper describes the measurements performed at IFIN-HH regarding the creation of a Romanian (124)I standard, consisting of: absolute standardization of the solution by the application of the 4πβ(PC)-γ coincidence method; Calibration of the CENTRONIC IG12/20A ionization chamber with a standardised solution and comparison with a calculated efficiency; γ-ray spectrometry activity measurement and determination of the impurity levels; Comparison of the results of the three methods.

  12. Noncontact Temperature Measurement

    NASA Technical Reports Server (NTRS)

    Lee, Mark C. (Editor)

    1988-01-01

    Noncontact temperature measurement has been identified as one of the eight advanced technology development (ATD) areas to support the effort of the Microgravity Science and Applications Division in developing six Space Station flight experiment facilities. This two-day workshop was an opportunity for all six disciplines to present their requirements on noncontact temperature measurement and to discuss state-of-the-art developments. Multi-color pyrometry, laser pyrometry and radiometric imaging techniques are addressed.

  13. Theory of Effectiveness Measurement

    DTIC Science & Technology

    2006-09-01

    according to a rule ( Stevens , 1959:25). However, not all assignment techniques are useful and some techniques have constraints on how the results can...3. Scale Hierarchy of Commonly Used Measures (Ford, 1993:9) Despite the generalized notation, only a few scale types exist ( Stevens , 1946:677...systems, a high order polynomial may yield an aggregated measure more closely capturing the system’s underlying nature ( Pinker , 1995:10): M=∑wimi+∑wimi2

  14. Lebesgue measure and gambling

    NASA Astrophysics Data System (ADS)

    Kanoveĭ, V. G.; Linton, Tom; Uspensky, Vladimir A.

    2008-12-01

    Lebesgue measure of point sets is characterized in terms of the existence of various strategies in a certain coin-flipping game. 'Rational' and 'discrete' modifications of this game are investigated. We prove that if one of the players has a winning strategy in a game of this type depending on a given set P\\subseteq \\lbrack 0,1 \\rbrack , then this set is measurable. Bibliography: 11 titles.

  15. Facility Measures Magnetic Fields

    NASA Technical Reports Server (NTRS)

    Honess, Shawn B.; Narvaez, Pablo; Mcauley, James M.

    1991-01-01

    Partly automated facility measures and computes steady near magnetic field produced by object. Designed to determine magnetic fields of equipment to be installed on spacecraft including sensitive magnetometers, with view toward application of compensating fields to reduce interfernece with spacecraft-magnetometer readings. Because of its convenient operating features and sensitivity of its measurements, facility serves as prototype for similar facilities devoted to magnetic characterization of medical equipment, magnets for high-energy particle accelerators, and magnetic materials.

  16. Lamb Shift Measurements

    NASA Astrophysics Data System (ADS)

    Pipkin, Francis M.

    The following sections are included: * INTRODUCTION * SUMMARY OF THEORY * CALCULATION OF SIGNALS * SLOW BEAM MEASUREMENTS * BOTTLE EXPERIMENTS * FAST BEAM EXPERIMENTS * Stark Quenching * Anisotropy of Quench Radiation * Quantum Beat Experiments * Atomic Interferometer * Fast Beam Radiofrequency Experiments * Single Field * Separated Oscillatory Fields * Fast Beam Laser Resonance * LASER SPECTROSCOPY * DIRECT MEASUREMENT OF LYMAN-a RADIATION * EXOTIC ATOMS * TWO ELECTRON ATOMS * COMPARISON OF THEORY AND EXPERIMENT * Hydrogne * Helium * High Z Atoms * PROSPECTS * ACKNOWLEDGEMENTS * References

  17. Objective Color Measuring System

    DTIC Science & Technology

    1982-09-01

    F. W. Billmeyer , Jr., Comparative performance of color measuring instruments, Appl. Optics 8, 775-783 (1969). 3 F. W. Billmeyer , Jr., E. D. Campbell...comments, Appl. Optics 14, 265 (1975). 4 R. T. Marcus and F. W. Billmeyer , Jr., Statistical study of color-measurement instrumentation, Appl. Optics 13... Billmeyer , Jr. and P. J. Alessi, Assessment of color-manuring instruments for objective textile acceptability judgment, NATICK/TR-79/044, US Army Natick R

  18. Ultrasonic differential measurement

    DOEpatents

    Rhodes, George W.; Migliori, Albert

    1995-01-01

    A method and apparatus for ultrasonic resonance testing of an object is shown and described. Acoustic vibrations are applied to an object at a plurality of frequencies. Measurements of the object's vibrational response are made simultaneously at different locations on said object. The input frequency is stepped by using small frequency changes over a predetermined range. There is a pause interval or ring delay which permits the object to reach a steady state resonance before a measurement is taken.

  19. Advanced Antenna Measurement Processing

    DTIC Science & Technology

    2014-06-18

    9.3 GHz slot array shown in Figure 1 and having a nominal directivity of 23 dB. This antenna was measured on an NSI Planar Near-field Scanner using... sidelobe level ; in essence, the antenna radiation pattern. Antenna pattern measurements have historically been conducted by placing a probe in the far...correction. It was noted in the earlier work that the best calibration antenna is one with a low gain so an open ended waveguide was used. This

  20. Pulse flux measuring device

    DOEpatents

    Riggan, William C.

    1985-01-01

    A device for measuring particle flux comprises first and second photodiode detectors for receiving flux from a source and first and second outputs for producing first and second signals representing the flux incident to the detectors. The device is capable of reducing the first output signal by a portion of the second output signal, thereby enhancing the accuracy of the device. Devices in accordance with the invention may measure distinct components of flux from a single source or fluxes from several sources.

  1. Photoreceiver efficiency measurements

    NASA Technical Reports Server (NTRS)

    Lehr, C. G.

    1975-01-01

    The efficiency and other related parameters of Smithsonian Astrophysical Observatory's four laser receivers were measured at the observing stations by oscilloscope photography. If the efficiency is defined as the number of photoelectrons generated by the photomultiplier tube divided by the number of photons entering the aperture of the receiver, its measured value is about 1% for the laser wavelength of 694 nm. This value is consistent with the efficiency computed from the specified characteristics of the photoreceiver's optical components.

  2. Measurement of dimensional stability

    NASA Technical Reports Server (NTRS)

    Jacobs, S. F.; Berthold, J. W., III; Norton, M.

    1975-01-01

    A technique was developed for measuring, with a precision of one part 10 to the 9th power, changes in physical dimensions delta L/L. Measurements have commenced on five materials: Heraeus-Schott Homosil (vitreous silica), Corning 7940 (vitreous silica), Corning ULE 7971 (titanium silicate), Schott Zero-Dur, and Owens-Illinois Cer-Vit C-101. The study was extended to include Universal Cyclops Invar LR-35 and Simonds-Saw Superinvar.

  3. Pressure Measurement Systems

    NASA Technical Reports Server (NTRS)

    1990-01-01

    System 8400 is an advanced system for measurement of gas and liquid pressure, along with a variety of other parameters, including voltage, frequency and digital inputs. System 8400 offers exceptionally high speed data acquisition through parallel processing, and its modular design allows expansion from a relatively inexpensive entry level system by the addition of modular Input Units that can be installed or removed in minutes. Douglas Juanarena was on the team of engineers that developed a new technology known as ESP (electronically scanned pressure). The Langley ESP measurement system was based on miniature integrated circuit pressure-sensing transducers that communicated pressure information to a minicomputer. In 1977, Juanarena formed PSI to exploit the NASA technology. In 1978 he left Langley, obtained a NASA license for the technology, introduced the first commercial product, the 780B pressure measurement system. PSI developed a pressure scanner for automation of industrial processes. Now in its second design generation, the DPT-6400 is capable of making 2,000 measurements a second and has 64 channels by addition of slave units. New system 8400 represents PSI's bid to further exploit the $600 million U.S. industrial pressure measurement market. It is geared to provide a turnkey solution to physical measurement.

  4. Measure problem in cosmology

    SciTech Connect

    Gibbons, G. W.; Turok, Neil

    2008-03-15

    The Hamiltonian structure of general relativity provides a natural canonical measure on the space of all classical universes, i.e., the multiverse. We review this construction and show how one can visualize the measure in terms of a 'magnetic flux' of solutions through phase space. Previous studies identified a divergence in the measure, which we observe to be due to the dilatation invariance of flat Friedmann-Lemaitre-Robertson-Walker universes. We show that the divergence is removed if we identify universes which are so flat they cannot be observationally distinguished. The resulting measure is independent of time and of the choice of coordinates on the space of fields. We further show that, for some quantities of interest, the measure is very insensitive to the details of how the identification is made. One such quantity is the probability of inflation in simple scalar field models. We find that, according to our implementation of the canonical measure, the probability for N e-folds of inflation in single-field, slow-roll models is suppressed by of order exp(-3N) and we discuss the implications of this result.

  5. Measures on mixing angles

    SciTech Connect

    Gibbons, Gary W.; Gielen, Steffen; Pope, C. N.; Turok, Neil

    2009-01-01

    We address the problem of the apparently very small magnitude of CP violation in the standard model, measured by the Jarlskog invariant J. In order to make statements about probabilities for certain values of J, we seek to find a natural measure on the space of Kobayashi-Maskawa matrices, the double quotient U(1){sup 2}/SU(3)/U(1){sup 2}. We review several possible, geometrically motivated choices of the measure, and compute expectation values for powers of J for these measures. We find that different choices of the measure generically make the observed magnitude of CP violation appear finely tuned. Since the quark masses and the mixing angles are determined by the same set of Yukawa couplings, we then do a second calculation in which we take the known quark mass hierarchy into account. We construct the simplest measure on the space of 3x3 Hermitian matrices which reproduces this known hierarchy. Calculating expectation values for powers of J in this second approach, we find that values of J close to the observed value are now rather likely, and there does not seem to be any fine-tuning. Our results suggest that the choice of Kobayashi-Maskawa angles is closely linked to the observed mass hierarchy. We close by discussing the corresponding case of neutrinos.

  6. Lead Thickness Measurements

    SciTech Connect

    Rucinski, R.; /Fermilab

    1998-02-16

    The preshower lead thickness applied to the outside of D-Zero's superconducting solenoid vacuum shell was measured at the time of application. This engineering documents those thickness measurements. The lead was ordered in sheets 0.09375-inch and 0.0625-inch thick. The tolerance on thickness was specified to be +/- 0.003-inch. The sheets all were within that thickness tolerance. The nomenclature for each sheet was designated 1T, 1B, 2T, 2B where the numeral designates it's location in the wrap and 'T' or 'B' is short for 'top' or 'bottom' half of the solenoid. Micrometer measurements were taken at six locations around the perimeter of each sheet. The width,length, and weight of each piece was then measured. Using an assumed pure lead density of 0.40974 lb/in{sup 3}, an average sheet thickness was calculated and compared to the perimeter thickness measurements. In every case, the calculated average thickness was a few mils thinner than the perimeter measurements. The ratio was constant, 0.98. This discrepancy is likely due to the assumed pure lead density. It is not felt that the perimeter is thicker than the center regions. The data suggests that the physical thickness of the sheets is uniform to +/- 0.0015-inch.

  7. How to measure metacognition.

    PubMed

    Fleming, Stephen M; Lau, Hakwan C

    2014-01-01

    The ability to recognize one's own successful cognitive processing, in e.g., perceptual or memory tasks, is often referred to as metacognition. How should we quantitatively measure such ability? Here we focus on a class of measures that assess the correspondence between trial-by-trial accuracy and one's own confidence. In general, for healthy subjects endowed with metacognitive sensitivity, when one is confident, one is more likely to be correct. Thus, the degree of association between accuracy and confidence can be taken as a quantitative measure of metacognition. However, many studies use a statistical correlation coefficient (e.g., Pearson's r) or its variant to assess this degree of association, and such measures are susceptible to undesirable influences from factors such as response biases. Here we review other measures based on signal detection theory and receiver operating characteristics (ROC) analysis that are "bias free," and relate these quantities to the calibration and discrimination measures developed in the probability estimation literature. We go on to distinguish between the related concepts of metacognitive bias (a difference in subjective confidence despite basic task performance remaining constant), metacognitive sensitivity (how good one is at distinguishing between one's own correct and incorrect judgments) and metacognitive efficiency (a subject's level of metacognitive sensitivity given a certain level of task performance). Finally, we discuss how these three concepts pose interesting questions for the study of metacognition and conscious awareness.

  8. Thermochromism in color measurement

    NASA Astrophysics Data System (ADS)

    Hiltunen, Jouni; Mutanen, J.; Jaeaeskelaeinen, Timo; Parkkinen, Jussi P. S.

    2002-06-01

    Accurate color measurements have become more and more important during the past few decades. This is valid not only in physical research but also in industrial production, where the importance of accurate measurements is mainly due to increased quality requirements set by the customers of various goods. The development of technology enables more and more accurate measuring systems. While the accuracy has improved one has noticed, that many unexpected factors affect the color of an object. One of these factors is the temperature of the sample. It is known that for example the reflectance of the ceramic reference tiles used for calibration of colorimeters and spectrophotometers is temperature dependent. This phenomenon is called thermochromism, which is a reversible change of color of the sample as a function of temperature. It may be noticed already at room temperature if the temperature varies few centigrades. Red and orange samples are especially sensitive to temperature variation and may cause difficulties in precise color measurements. We show, how the phenomenon is based on physical processes and not only reflects the instability of red color pigments. We derive simple formulas, which are shown to explain the experimental data. We also discuss the meaning of thermochromism for color measurements, measure the magnitude of it and propose the experimental conditions to avoid this effect.

  9. Pressure Measurement Systems

    NASA Astrophysics Data System (ADS)

    1990-01-01

    System 8400 is an advanced system for measurement of gas and liquid pressure, along with a variety of other parameters, including voltage, frequency and digital inputs. System 8400 offers exceptionally high speed data acquisition through parallel processing, and its modular design allows expansion from a relatively inexpensive entry level system by the addition of modular Input Units that can be installed or removed in minutes. Douglas Juanarena was on the team of engineers that developed a new technology known as ESP (electronically scanned pressure). The Langley ESP measurement system was based on miniature integrated circuit pressure-sensing transducers that communicated pressure information to a minicomputer. In 1977, Juanarena formed PSI to exploit the NASA technology. In 1978 he left Langley, obtained a NASA license for the technology, introduced the first commercial product, the 780B pressure measurement system. PSI developed a pressure scanner for automation of industrial processes. Now in its second design generation, the DPT-6400 is capable of making 2,000 measurements a second and has 64 channels by addition of slave units. New system 8400 represents PSI's bid to further exploit the 600 million U.S. industrial pressure measurement market. It is geared to provide a turnkey solution to physical measurement.

  10. Critique of protective measurements

    SciTech Connect

    Hari Dass, N.D.; Qureshi, T.

    1999-04-01

    The recently proposed idea of {open_quotes}protective{close_quotes} measurement of a quantum state is critically examined, and generalized. Earlier criticisms of the idea are discussed, and their relevance to the proposal assessed. Several constraints on measuring apparatus required by {open_quotes}protective{close_quotes} measurements are discussed, with emphasis on how they may restrict their experimental feasibility. Though {open_quotes}protective{close_quotes} measurements result in an unchanged system state and a shift of the pointer proportional to the expectation value of the measured observable in the system state, the actual reading of the pointer position gives rise to several subtleties. We propose several schemes for reading the pointer position, both when the apparatus is treated as a classical system as well as when its quantum aspects are taken into account, that address these issues. The tiny entanglement which is always present due to deviation from extreme adiabaticity in realistic situations is argued to be the weakest aspect of the proposal. Because of this, one can never perform a protective measurement on a single quantum system with absolute certainty. This clearly precludes an ontological status for the wave function. Several other conceptual issues are also discussed. {copyright} {ital 1999} {ital The American Physical Society}

  11. How to measure metacognition

    PubMed Central

    Fleming, Stephen M.; Lau, Hakwan C.

    2014-01-01

    The ability to recognize one's own successful cognitive processing, in e.g., perceptual or memory tasks, is often referred to as metacognition. How should we quantitatively measure such ability? Here we focus on a class of measures that assess the correspondence between trial-by-trial accuracy and one's own confidence. In general, for healthy subjects endowed with metacognitive sensitivity, when one is confident, one is more likely to be correct. Thus, the degree of association between accuracy and confidence can be taken as a quantitative measure of metacognition. However, many studies use a statistical correlation coefficient (e.g., Pearson's r) or its variant to assess this degree of association, and such measures are susceptible to undesirable influences from factors such as response biases. Here we review other measures based on signal detection theory and receiver operating characteristics (ROC) analysis that are “bias free,” and relate these quantities to the calibration and discrimination measures developed in the probability estimation literature. We go on to distinguish between the related concepts of metacognitive bias (a difference in subjective confidence despite basic task performance remaining constant), metacognitive sensitivity (how good one is at distinguishing between one's own correct and incorrect judgments) and metacognitive efficiency (a subject's level of metacognitive sensitivity given a certain level of task performance). Finally, we discuss how these three concepts pose interesting questions for the study of metacognition and conscious awareness. PMID:25076880

  12. ''When Cost Measures Contradict''

    SciTech Connect

    Montgomery, W. D.; Smith, A. E.; Biggar, S. L.; Bernstein, P. M.

    2003-05-09

    When regulators put forward new economic or regulatory policies, there is a need to compare the costs and benefits of these new policies to existing policies and other alternatives to determine which policy is most cost-effective. For command and control policies, it is quite difficult to compute costs, but for more market-based policies, economists have had a great deal of success employing general equilibrium models to assess a policy's costs. Not all cost measures, however, arrive at the same ranking. Furthermore, cost measures can produce contradictory results for a specific policy. These problems make it difficult for a policy-maker to determine the best policy. For a cost measures to be of value, one would like to be confident of two things. First one wants to be sure whether the policy is a winner or loser. Second, one wants to be confident that a measure produces the correct policy ranking. That is, one wants to have confidence in a policy measure's ability to correctly rank policies from most beneficial to most harmful. This paper analyzes empirically these two properties of different costs measures as they pertain to assessing the costs of the carbon abatement policies, especially the Kyoto Protocol, under alternative assumptions about implementation.

  13. Measures of rowing performance.

    PubMed

    Smith, T Brett; Hopkins, Will G

    2012-04-01

    Accurate measures of performance are important for assessing competitive athletes in practi~al and research settings. We present here a review of rowing performance measures, focusing on the errors in these measures and the implications for testing rowers. The yardstick for assessing error in a performance measure is the random variation (typical or standard error of measurement) in an elite athlete's competitive performance from race to race: ∼1.0% for time in 2000 m rowing events. There has been little research interest in on-water time trials for assessing rowing performance, owing to logistic difficulties and environmental perturbations in performance time with such tests. Mobile ergometry via instrumented oars or rowlocks should reduce these problems, but the associated errors have not yet been reported. Measurement of boat speed to monitor on-water training performance is common; one device based on global positioning system (GPS) technology contributes negligible extra random error (0.2%) in speed measured over 2000 m, but extra error is substantial (1-10%) with other GPS devices or with an impeller, especially over shorter distances. The problems with on-water testing have led to widespread use of the Concept II rowing ergometer. The standard error of the estimate of on-water 2000 m time predicted by 2000 m ergometer performance was 2.6% and 7.2% in two studies, reflecting different effects of skill, body mass and environment in on-water versus ergometer performance. However, well trained rowers have a typical error in performance time of only ∼0.5% between repeated 2000 m time trials on this ergometer, so such trials are suitable for tracking changes in physiological performance and factors affecting it. Many researchers have used the 2000 m ergometer performance time as a criterion to identify other predictors of rowing performance. Standard errors of the estimate vary widely between studies even for the same predictor, but the lowest

  14. Engine Test and Measurements

    NASA Technical Reports Server (NTRS)

    Wey, Chown Chou

    1999-01-01

    Although the importance of aerosols and their precursors are now well recognized, the characterization of current subsonic engines for these emissions is far from complete. Furthermore, since the relationship of engine operating parameters to aerosol emissions is not known, extrapolation to untested and unbuilt engines necessarily remains highly uncertain. 1997 NASA LaRC engine test, as well as the parallel 1997 NASA LaRC flight measurement, attempts to address both issues by expanding measurements of aerosols and aerosol precursors with fuels containing different levels of fuel sulfur content. The specific objective of the 1997 engine test is to obtain a database of sulfur oxides emissions as well as the non-volatile particulate emission properties as a function of fuel sulfur and engine operating conditions. Four diagnostic systems, extractive and non-intrusive (optical), will be assembled for the gaseous and particulate emissions characterization measurements study. NASA is responsible for the extractive gaseous emissions measurement system which contains an array of analyzers dedicated to examining the concentrations of specific gases (NO, NO(x), CO, CO2, O2, THC, SO2) and the smoke number. University of Missouri-Rolla uses the Mobile Aerosol Sampling System to measure aerosol/particulate total concentration, size distribution, volatility and hydration property. Air Force Research Laboratory uses the Chemical Ionization Mass Spectrometer to measure SO2, SO3/H2SO4, and HN03 Aerodyne Research, Inc. uses Infrared Tunable Diode Laser system to measure SO2, SO3, NO, H2O, and CO2.

  15. Statistics and Measurements

    PubMed Central

    Croarkin, M. Carroll

    2001-01-01

    For more than 50 years, the Statistical Engineering Division (SED) has been instrumental in the success of a broad spectrum of metrology projects at NBS/NIST. This paper highlights fundamental contributions of NBS/NIST statisticians to statistics and to measurement science and technology. Published methods developed by SED staff, especially during the early years, endure as cornerstones of statistics not only in metrology and standards applications, but as data-analytic resources used across all disciplines. The history of statistics at NBS/NIST began with the formation of what is now the SED. Examples from the first five decades of the SED illustrate the critical role of the division in the successful resolution of a few of the highly visible, and sometimes controversial, statistical studies of national importance. A review of the history of major early publications of the division on statistical methods, design of experiments, and error analysis and uncertainty is followed by a survey of several thematic areas. The accompanying examples illustrate the importance of SED in the history of statistics, measurements and standards: calibration and measurement assurance, interlaboratory tests, development of measurement methods, Standard Reference Materials, statistical computing, and dissemination of measurement technology. A brief look forward sketches the expanding opportunity and demand for SED statisticians created by current trends in research and development at NIST. PMID:27500023

  16. The performance measurement manifesto.

    PubMed

    Eccles, R G

    1991-01-01

    The leading indicators of business performance cannot be found in financial data alone. Quality, customer satisfaction, innovation, market share--metrics like these often reflect a company's economic condition and growth prospects better than its reported earnings do. Depending on an accounting department to reveal a company's future will leave it hopelessly mired in the past. More and more managers are changing their company's performance measurement systems to track nonfinancial measures and reinforce new competitive strategies. Five activities are essential: developing an information architecture; putting the technology in place to support this architecture; aligning bonuses and other incentives with the new system; drawing on outside resources; and designing an internal process to ensure the other four activities occur. New technologies and more sophisticated databases have made the change to nonfinancial performance measurement systems possible and economically feasible. Industry and trade associations, consulting firms, and public accounting firms that already have well-developed methods for assessing market share and other performance metrics can add to the revolution's momentum--as well as profit from the business opportunities it presents. Every company will have its own key measures and distinctive process for implementing the change. But making it happen will always require careful preparation, perseverance, and the conviction of the CEO that it must be carried through. When one leading company can demonstrate the long-term advantage of its superior performance on quality or innovation or any other nonfinancial measure, it will change the rules for all its rivals forever.

  17. Statistics and Measurements.

    PubMed

    Croarkin, M C

    2001-01-01

    For more than 50 years, the Statistical Engineering Division (SED) has been instrumental in the success of a broad spectrum of metrology projects at NBS/NIST. This paper highlights fundamental contributions of NBS/NIST statisticians to statistics and to measurement science and technology. Published methods developed by SED staff, especially during the early years, endure as cornerstones of statistics not only in metrology and standards applications, but as data-analytic resources used across all disciplines. The history of statistics at NBS/NIST began with the formation of what is now the SED. Examples from the first five decades of the SED illustrate the critical role of the division in the successful resolution of a few of the highly visible, and sometimes controversial, statistical studies of national importance. A review of the history of major early publications of the division on statistical methods, design of experiments, and error analysis and uncertainty is followed by a survey of several thematic areas. The accompanying examples illustrate the importance of SED in the history of statistics, measurements and standards: calibration and measurement assurance, interlaboratory tests, development of measurement methods, Standard Reference Materials, statistical computing, and dissemination of measurement technology. A brief look forward sketches the expanding opportunity and demand for SED statisticians created by current trends in research and development at NIST.

  18. On wave radar measurement

    NASA Astrophysics Data System (ADS)

    Ewans, Kevin; Feld, Graham; Jonathan, Philip

    2014-09-01

    The SAAB REX WaveRadar sensor is widely used for platform-based wave measurement systems by the offshore oil and gas industry. It offers in situ surface elevation wave measurements at relatively low operational costs. Furthermore, there is adequate flexibility in sampling rates, allowing in principle sampling frequencies from 1 to 10 Hz, but with an angular microwave beam width of 10° and an implied ocean surface footprint in the order of metres, significant limitations on the spatial and temporal resolution might be expected. Indeed there are reports that the accuracy of the measurements from wave radars may not be as good as expected. We review the functionality of a WaveRadar using numerical simulations to better understand how WaveRadar estimates compare with known surface elevations. In addition, we review recent field measurements made with a WaveRadar set at the maximum sampling frequency, in the light of the expected functionality and the numerical simulations, and we include inter-comparisons between SAAB radars and buoy measurements for locations in the North Sea.

  19. Uncertainties in successive measurements

    NASA Astrophysics Data System (ADS)

    Distler, Jacques; Paban, Sonia

    2013-06-01

    When you measure an observable, A, in quantum mechanics, the state of the system changes. This, in turn, affects the quantum-mechanical uncertainty in some noncommuting observable, B. The standard uncertainty relation puts a lower bound on the uncertainty of B in the initial state. What is relevant for a subsequent measurement of B, however, is the uncertainty of B in the postmeasurement state. We re-examine this problem, both in the case where A has a pure point spectrum and in the case where A has a continuous spectrum. In the latter case, the need to include a finite detector resolution, as part of what it means to measure such an observable, has dramatic implications for the result of successive measurements. Ozawa, [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.67.042105 67, 042105 (2003)] proposed an inequality satisfied in the case of successive measurements. Among our results, we show that his inequality is ineffective (can never come close to being saturated). For the cases of interest, we compute a sharper lower bound.

  20. Fluctuation Measurements in MRX

    NASA Astrophysics Data System (ADS)

    Carter, T.; Hsu, S.; Zaharia, S.; Ji, H.; Yamada, M.; Kulsrud, R.; Mazzucato, E.

    1998-11-01

    Recently, data(H. Ji, et al), Phys. Rev. Lett., 80, 3256 (1998) from the Magnetic Reconnection Experiment (MRX) have shown agreement with an MHD (Sweet-Parker) scaling modified to include, among other effects, an experimentally measured resistivity in collisionless current sheets for which η > η_Spitzer. Consistent with the observation of enhanced resistivity in these experiments was the measurement of current sheet widths on the order of ρ_i. Current sheet width scaling with ρi implies a drift parameter (v_d,i-v_d,e)/v_th,i which is constant with density. A potential explanation for these three observations is the existence of a current-driven instability in the current sheet of MRX which limits the relative drift speed, enhances the resistivity and widens the reconnection layer. Studies of fluctuations in the current sheet of MRX have begun, and preliminary fluctuation measurements using floating Langmuir and magnetic pick-up probes reveal frequency spectra with strong features near 30 MHz (≈ ω_LH). Theoretical studies of instabilities in the MRX current sheet and detailed measurements of frequency spectra using these diagnostics will be presented along with preliminary measurements using a new 35.6 cm-1 microwave scattering system.

  1. Metrology Measurement Capabilities

    SciTech Connect

    Barnes, L.M.

    2003-11-12

    This document contains descriptions of Federal Manufacturing & Technologies (FM&T) Metrology capabilities, traceability flow charts, and the measurement uncertainty of each measurement capability. Metrology provides NIST traceable precision measurements or equipment calibration for a wide variety of parameters, ranges, and state-of-the-art uncertainties. Metrology laboratories conform to the requirements of the Department of Energy Development and Production Manual Chapter 8.4, ANSI/ISO/IEC ANSI/ISO/IEC 17025:2000, and ANSI/NCSL Z540-1 (equivalent to ISO Guide 25). FM&T Metrology laboratories are accredited by NVLAP for the parameters, ranges, and uncertainties listed in the specific scope of accreditation under NVLAP Lab code 200108-0. See the Internet at http://ts.nist.gov/ts/htdocs/210/214/scopes/2001080.pdf. These parameters are summarized in the table at the bottom of this introduction.

  2. Thermal Properties Measurement Report

    SciTech Connect

    Carmack, Jon; Braase, Lori; Papesch, Cynthia; Hurley, David; Tonks, Michael; Zhang, Yongfeng; Gofryk, Krzysztof; Harp, Jason; Fielding, Randy; Knight, Collin; Meyer, Mitch

    2015-08-01

    The Thermal Properties Measurement Report summarizes the research, development, installation, and initial use of significant experimental thermal property characterization capabilities at the INL in FY 2015. These new capabilities were used to characterize a U3Si2 (candidate Accident Tolerant) fuel sample fabricated at the INL. The ability to perform measurements at various length scales is important and provides additional data that is not currently in the literature. However, the real value of the data will be in accomplishing a phenomenological understanding of the thermal conductivity in fuels and the ties to predictive modeling. Thus, the MARMOT advanced modeling and simulation capability was utilized to illustrate how the microstructural data can be modeled and compared with bulk characterization data. A scientific method was established for thermal property measurement capability on irradiated nuclear fuel samples, which will be installed in the Irradiated Material Characterization Laboratory (IMCL).

  3. Electrochemical thermodynamic measurement system

    DOEpatents

    Reynier, Yvan; Yazami, Rachid; Fultz, Brent T.

    2009-09-29

    The present invention provides systems and methods for accurately characterizing thermodynamic and materials properties of electrodes and electrochemical energy storage and conversion systems. Systems and methods of the present invention are configured for simultaneously collecting a suite of measurements characterizing a plurality of interconnected electrochemical and thermodynamic parameters relating to the electrode reaction state of advancement, voltage and temperature. Enhanced sensitivity provided by the present methods and systems combined with measurement conditions that reflect thermodynamically stabilized electrode conditions allow very accurate measurement of thermodynamic parameters, including state functions such as the Gibbs free energy, enthalpy and entropy of electrode/electrochemical cell reactions, that enable prediction of important performance attributes of electrode materials and electrochemical systems, such as the energy, power density, current rate and the cycle life of an electrochemical cell.

  4. Magnet measurement workshop

    SciTech Connect

    1986-12-01

    This report covers the deliberations of the participants the workshop and some subsequent contributions. Section III, the report of the rotating coil group, includes a summary table of the major measuring systems in use today, with separate sections on each. Section IV is the summary report of the group that addressed other measuring techniques. Because one of the limits of all the techniques being considered is electronic data acquisition, Section V addresses this topic. A set of issues relevant to magnetic field measurements of SSC dipoles was raised and addressed during the workshop. These are included as Section VI. Section VII includes a complete list of attendees with their addresses and a separate list of the members of the two working groups.

  5. Cometary Isotopic Measurements

    NASA Astrophysics Data System (ADS)

    Bockelée-Morvan, Dominique; Calmonte, Ursina; Charnley, Steven; Duprat, Jean; Engrand, Cécile; Gicquel, Adeline; Hässig, Myrtha; Jehin, Emmanuël; Kawakita, Hideyo; Marty, Bernard; Milam, Stefanie; Morse, Andrew; Rousselot, Philippe; Sheridan, Simon; Wirström, Eva

    2015-12-01

    Isotopic ratios in comets provide keys for the understanding of the origin of cometary material, and the physical and chemical conditions in the early Solar Nebula. We review here measurements acquired on the D/H, 14N/15N, 16O/18O, 12C/13C, and 32S/34S ratios in cometary grains and gases, and discuss their cosmogonic implications. The review includes analyses of potential cometary material available in collections on Earth, recent measurements achieved with the Herschel Space Observatory, large optical telescopes, and Rosetta, as well as recent results obtained from models of chemical-dynamical deuterium fractionation in the early solar nebula. Prospects for future measurements are presented.

  6. System for Measuring Capacitance

    NASA Technical Reports Server (NTRS)

    McNichol, Randal S. (Inventor)

    2001-01-01

    A system has been developed for detecting the level of a liquid in a tank wherein a capacitor positioned in the tank has spaced plates which are positioned such that the dielectric between the plates will be either air or the liquid, depending on the depth of the liquid in the tank. An oscillator supplies a sine wave current to the capacitor and a coaxial cable connects the capacitor to a measuring circuit outside the tank. If the cable is very long or the capacitance to be measured is low, the capacitance inherent in the coaxial cable will prevent an accurate reading. To avoid this problem, an inductor is connected across the cable to form with the capacitance of the cable a parallel resonant circuit. The impedance of the parallel resonant circuit is infinite, so that attenuation of the measurement signal by the stray cable capacitance is avoided.

  7. Precision Measurement in Biology

    NASA Astrophysics Data System (ADS)

    Quake, Stephen

    Is biology a quantitative science like physics? I will discuss the role of precision measurement in both physics and biology, and argue that in fact both fields can be tied together by the use and consequences of precision measurement. The elementary quanta of biology are twofold: the macromolecule and the cell. Cells are the fundamental unit of life, and macromolecules are the fundamental elements of the cell. I will describe how precision measurements have been used to explore the basic properties of these quanta, and more generally how the quest for higher precision almost inevitably leads to the development of new technologies, which in turn catalyze further scientific discovery. In the 21st century, there are no remaining experimental barriers to biology becoming a truly quantitative and mathematical science.

  8. Enhanced Microfluidic Electromagnetic Measurements

    NASA Technical Reports Server (NTRS)

    Giovangrandi, Laurent (Inventor); Ricco, Antonio J. (Inventor); Kovacs, Gregory (Inventor)

    2015-01-01

    Techniques for enhanced microfluidic impedance spectroscopy include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. Flow in the channel is laminar. A dielectric constant of a fluid constituting either sheath flow is much less than a dielectric constant of the core fluid. Electrical impedance is measured in the channel between at least a first pair of electrodes. In some embodiments, enhanced optical measurements include causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid. An optical index of refraction of a fluid constituting either sheath flow is much less than an optical index of refraction of the core fluid. An optical property is measured in the channel.

  9. Optical measurement systems

    NASA Technical Reports Server (NTRS)

    Lesco, Daniel J.

    1987-01-01

    Some of the areas of research conducted at Lewis on optical measurement techniques are described. Two laser anemometer systems developed at Lewis are used to illustrate the special instrumentation needs encountered in aeropropulsion research. Velocity measurements to be made through small viewing ports, close to surfaces within the propulsion system components, and in turbulent or highly-accelerating flows are some of the significant challenges. The application to research facilities of two advanced optical systems, the rainbow schlieren and the combustor viewing system, is presented. The calibration and verification of commercial optical measuring systems, such as droplet sizing systems, are also discussed. Calibration techniques capable of simulating moving droplets for flight-type sizing systems are being developed at Lewis. The presentation concludes with a brief look at the forces driving future research on optical instrumentation.

  10. Blade pressure measurements

    NASA Astrophysics Data System (ADS)

    Chivers, J. W. H.

    Three measurement techniques which enable rotating pressures to be measured during the normal operation of a gas turbine or a component test rig are described. The first technique was developed specifically to provide steady and transient blade surface pressure data to aid both fan flutter research and general fan performance development. This technique involves the insertion of miniature high frequency response pressure transducers into the fan blades of a large civil gas turbine. The other two techniques were developed to measure steady rotating pressures inside and on the surface of engine or rig turbine blades and also rotating pressures in cooling feed systems. These two low frequency response systems are known as the "pressure pineapple' (a name which resulted from the shape of the original prototype) and the rotating scanivalve.

  11. Contour measurement system

    NASA Technical Reports Server (NTRS)

    Currie, J. R.; Kissel, R. R.; Deaton, E. T., Jr.; Campbell, R. A. (Inventor)

    1979-01-01

    A measurement system for measuring the departures from a straight line of discrete track sections of a track along a coal face in a mine employing a vehicle having a pair of spaced wheel assemblies which align with the track is presented. A reference arm pivotally connects between the wheel assemblies, and there is indicating means for measuring the angle of pivot between the arm and each of the wheel assemblies. The length of the device is less than the length of a track section, and thus when one of the wheel assemblies is on one track section and one is on an adjoining track section, the sum of the indicated angles will be indicative of the angle between track sections. Thus, from the length of a track section and angle, the departure of each track section from the line may be calculated.

  12. Measuring marketing effectiveness.

    PubMed

    Gluckman, J; Michaelis, T

    1987-09-01

    The most frequent question about the marketing function in hospitals today is, What are we getting for our money? To answer this, marketing directors must convince the board first of the need for marketing, then of marketing's effectiveness. To measure marketing effectiveness, some basic needs are a staff, equipment, cooperation between departments, utilization data, and a research budget. Some steps to be followed include developing a marketing data base--consisting of demographic projections, demand projections, and market share--testing a marketing strategy through experimentation, documenting the expected results and measurement techniques, and calculating the expected return on investments. In dealing with those "impossible-to-measure" cases, such as a physician who is not advertising but finds that a competitor is, a decision tree can help determine whether to advertise and how much to spend by indicating what the return on investment might be.

  13. Advanced Ceramics Property Measurements

    NASA Technical Reports Server (NTRS)

    Salem, Jonathan; Helfinstine, John; Quinn, George; Gonczy, Stephen

    2013-01-01

    Mechanical and physical properties of ceramic bodies can be difficult to measure correctly unless the proper techniques are used. The Advanced Ceramics Committee of ASTM, C-28, has developed dozens of consensus test standards and practices to measure various properties of a ceramic monolith, composite, or coating. The standards give the "what, how, how not, and why" for measurement of many mechanical, physical, thermal, and performance properties. Using these standards will provide accurate, reliable, and complete data for rigorous comparisons with other test results from your test lab, or another. The C-28 Committee has involved academics, producers, and users of ceramics to write and continually update more than 45 standards since the committee's inception in 1986. Included in this poster is a pictogram of the C-28 standards and information on how to obtain individual copies with full details or the complete collection of standards in one volume.

  14. Paradoxes of measurement.

    PubMed

    Heelan, Patrick A

    2003-05-01

    Applying Husserl's Eidetic Phenomenology to the transcendental structure (or "phenomenological reduction") of scientific data "given" in measurement to a first-person individual observer (the experimenter, S(1)) and a related third-person individual observer (the observer of the measurement process, S(3)), and comparing the outcomes, two paradoxical theses, "paradoxes of measurement," are derived. Thesis I: classical science necessarily entails "complementarity," "uncertainty relations," and the "entanglement" of observers and the data they observe. This situation is analogous in structure to that of quantum physics. Thesis II: a quantum object is a physical object with footprints in the perceptual world, but lacking a space-time "body"; it exists ontologically before the constitution of the perceptual world of the laboratory.

  15. Video integrated measurement system.

    PubMed

    Spector, B; Eilbert, L; Finando, S; Fukuda, F

    1982-06-01

    A Video Integrated Measurement (VIM) System is described which incorporates the use of various noninvasive diagnostic procedures (moire contourography, electromyography, posturometry, infrared thermography, etc.), used individually or in combination, for the evaluation of neuromusculoskeletal and other disorders and their management with biofeedback and other therapeutic procedures. The system provides for measuring individual diagnostic and therapeutic modes, or multiple modes by split screen superimposition, of real time (actual) images of the patient and idealized (ideal-normal) models on a video monitor, along with analog and digital data, graphics, color, and other transduced symbolic information. It is concluded that this system provides an innovative and efficient method by which the therapist and patient can interact in biofeedback training/learning processes and holds considerable promise for more effective measurement and treatment of a wide variety of physical and behavioral disorders.

  16. Structural power flow measurement

    SciTech Connect

    Falter, K.J.; Keltie, R.F.

    1988-12-01

    Previous investigations of structural power flow through beam-like structures resulted in some unexplained anomalies in the calculated data. In order to develop structural power flow measurement as a viable technique for machine tool design, the causes of these anomalies needed to be found. Once found, techniques for eliminating the errors could be developed. Error sources were found in the experimental apparatus itself as well as in the instrumentation. Although flexural waves are the carriers of power in the experimental apparatus, at some frequencies longitudinal waves were excited which were picked up by the accelerometers and altered power measurements. Errors were found in the phase and gain response of the sensors and amplifiers used for measurement. A transfer function correction technique was employed to compensate for these instrumentation errors.

  17. Measurement uncertainty relations

    SciTech Connect

    Busch, Paul; Lahti, Pekka; Werner, Reinhard F.

    2014-04-15

    Measurement uncertainty relations are quantitative bounds on the errors in an approximate joint measurement of two observables. They can be seen as a generalization of the error/disturbance tradeoff first discussed heuristically by Heisenberg. Here we prove such relations for the case of two canonically conjugate observables like position and momentum, and establish a close connection with the more familiar preparation uncertainty relations constraining the sharpness of the distributions of the two observables in the same state. Both sets of relations are generalized to means of order α rather than the usual quadratic means, and we show that the optimal constants are the same for preparation and for measurement uncertainty. The constants are determined numerically and compared with some bounds in the literature. In both cases, the near-saturation of the inequalities entails that the state (resp. observable) is uniformly close to a minimizing one.

  18. Metrology Measurement Capabilities

    SciTech Connect

    Barnes, L.M.

    2000-03-23

    This document contains descriptions of Federal Manufacturing and Technologies (FM and T) Metrology capabilities, traceability flow charts, and the measurement uncertainty of each measurement capability. Metrology provides NIST traceable precision measurements or equipment calibration for a wide variety of parameters, ranges, and state-of-the-art uncertainties in laboratories that conform to the requirements of the Department of Energy Development and Production Manual Chapter 8.4, and ANSI/NCSL Z540-1 (equivalent to ISO Guide 25). FM and T Metrology laboratories are accredited by NVLAP for the parameters, ranges, and uncertainties listed in the specific scope of accreditation under NVLAP Lab code 200108-0. These parameters are summarized.

  19. Measurement of costs.

    PubMed

    Riewpaiboon, Arthorn

    2008-06-01

    Costing plays an important role in health economics, particularly economic evaluation. However, there are some controversial issues: concepts, methods and reference values. Hence, it is pivotal to standardize can be con costing methods and use these as national guidelines to produce comparable studies. This report is divided perspectives. into 3 parts: theoretical issues, international guidelines comparison, and recommendations for the Thai technology assessment guidelines. Each section is composed of three general costing steps: identification, appropriate, measuring and valuation. It is recommended to measure economic or opportunity cost mainly in societal perspective. Cost category is composed of direct medical, direct non-medical and indirect costs. The level of reliability of each kind of costing source data is provided. Valuation of resource use based on national government, standard cost menu is recommended for national policy making. The recommendations on cost measurement are appropriate for the Thai context and in the current situation.

  20. Measurement validity in ophthalmology.

    PubMed

    Aslam, Tariq M; Patton, Niall

    2005-04-01

    Measurements in ophthalmic research may be of parameters such as visual functions, quality of life or physical measures and can involve different types of instruments such as questionnaires and mechanical, chemical or electronic devices. Whatever the mode of measurement, however, all these devices require sufficient evidence for validity before inferences can be made on the basis of their findings. This article explores the nature and often overlooked importance of validity and explains some of the terminology involved. It discusses the main forms that ophthalmologists should be aware of before they can assess whether the instruments, old and new, are providing results upon which inferences can be made with any level of confidence. The literature search involved use of Medline, PubMed and Ovid as well as referenced papers in journals and books. Searches were comprehensive and international. Foreign texts were translated.

  1. Measuring ambivalence to science

    NASA Astrophysics Data System (ADS)

    Gardner, P. L.

    Ambivalence is a psychological state in which a person holds mixed feelings (positive and negative) towards some psychological object. Standard methods of attitude measurement, such as Likert and semantic differential scales, ignore the possibility of ambivalence; ambivalent responses cannot be distinguished from neutral ones. This neglect arises out of an assumption that positive and negative affects towards a particular psychological object are bipolar, i.e., unidimensional in opposite directions. This assumption is frequently untenable. Conventional item statistics and measures of test internal consistency are ineffective as checks on this assumption; it is possible for a scale to be multidimensional and still display apparent internal consistency. Factor analysis is a more effective procedure. Methods of measuring ambivalence are suggested, and implications for research are discussed.

  2. Downhole steam quality measurement

    DOEpatents

    Lee, D.O.; Montoya, P.C.; Muir, J.F.; Wayland, J.R. Jr.

    1985-06-19

    The present invention relates to an empirical electrical method for remote sensing of steam quality utilizing flow-through grids which allow measurement of the electrical properties of a flowing two-phase mixture. The measurement of steam quality in the oil field is important to the efficient application of steam assisted recovery of oil. Because of the increased energy content in higher quality steam it is important to maintain the highest possible steam quality at the injection sandface. The effectiveness of a steaming operation without a measure of steam quality downhole close to the point of injection would be difficult to determine. Therefore, a need exists for the remote sensing of steam quality.

  3. Measuring Education and Skill

    PubMed Central

    Muller, Chandra

    2015-01-01

    This article reviews recent developments in measuring education and skill that need to be taken into account in any new initiative to monitor social mobility. Over the past half-century, patterns of educational participation and attainment have become more heterogeneous, a trend that has been accompanied by increases in assessment and testing practices, and the availability of electronic data sources and other administrative records, including official school transcripts that are generally held indefinitely. This article describes the most promising approaches to measuring education and discusses some of the possible challenges for using the information to study social mobility. Measures of educational concepts fall along at least one of several dimensions: credentials earned, qualities of the schools attended, the amount and nature of curricular exposure, and the development and acquisition of skills. Selected data sources, with an emphasis on school transcripts and administrative records, and their possible uses are described. PMID:25983334

  4. CHALLENGE MEASUREMENTS FOR AUTHENTICATION

    SciTech Connect

    Pitts, W. Karl

    2009-10-07

    Authentication of systems with an information barrier that protects sensitive information is difficult; in particular, the information barrier can allow a hidden switch to be implemented by the system fabricator and operator. The hidden switch is the operator’s ability to subvert the measurement system and force it to produce a desired and false result. It is usually discussed in the context of an attribute measurement in which a faked item is presented in place of a real item regulated by an agreement, with the driving motivation being the ability to preserve a stock of valuable items. In simple terms, the hidden switch enables a shell game with assets, and the information barrier protects the switch. This presentation outlines challenge measurements that could be used to detect the implementation of a hidden switch and assist the authentication process.

  5. Novel Diffusivity Measurement Technique

    NASA Technical Reports Server (NTRS)

    Rashidnia, Nasser

    2001-01-01

    A common-path interferometer (CPI) system was developed to measure the diffusivity of liquid pairs. The CPI is an optical technique that can be used to measure changes in the gradient of the refraction index of transparent materials. This system uses a shearing interferometer that shares the same optical path from a laser light source to the final imaging plane. Hence, the molecular diffusion coefficient of liquids can be determined using the physical relations between changes in the optical path length and the liquid phase properties. The data obtained with this interferometer were compared with similar results from other techniques and demonstrated that the instrument is superior in measuring the diffusivity of miscible liquids while keeping the system very compact and robust. CPI can also be used for studies in interface dynamics and other diffusion-dominated-process applications.

  6. Colour Measurements and Modeling

    NASA Astrophysics Data System (ADS)

    Jha, Shyam N.

    The most common property to measure quality of any material is its appearance. Appearance includes colour, shape, size and surface conditions. The analysis of colour is especially an important consideration when determining the efficacy of variety of postharvest treatments. Consumers can easily be influenced by preconceived ideas of how a particular fruit or vegetable or a processed food should appear, and marketers often attempt to improve upon what nature has painted. Recently colour measurements have also been used as quality parameters and indicator of some inner constituents of the material. In spite of the significance of colour in food industries, many continue to analyze it inadequately. This chapter deals with theory of colour, colour scales and its measurement, sampling techniques, and modeling of colour values for correlating them with some internal quality parameters of selected fruits.

  7. Measuring Education and Skill.

    PubMed

    Muller, Chandra

    2015-01-01

    This article reviews recent developments in measuring education and skill that need to be taken into account in any new initiative to monitor social mobility. Over the past half-century, patterns of educational participation and attainment have become more heterogeneous, a trend that has been accompanied by increases in assessment and testing practices, and the availability of electronic data sources and other administrative records, including official school transcripts that are generally held indefinitely. This article describes the most promising approaches to measuring education and discusses some of the possible challenges for using the information to study social mobility. Measures of educational concepts fall along at least one of several dimensions: credentials earned, qualities of the schools attended, the amount and nature of curricular exposure, and the development and acquisition of skills. Selected data sources, with an emphasis on school transcripts and administrative records, and their possible uses are described.

  8. Neutron beam measurement dosimetry

    SciTech Connect

    Amaro, C.R.

    1995-11-01

    This report describes animal dosimetry studies and phantom measurements. During 1994, 12 dogs were irradiated at BMRR as part of a 4 fraction dose tolerance study. The animals were first infused with BSH and irradiated daily for 4 consecutive days. BNL irradiated 2 beagles as part of their dose tolerance study using BPA fructose. In addition, a dog at WSU was irradiated at BMRR after an infusion of BPA fructose. During 1994, the INEL BNCT dosimetry team measured neutron flux and gamma dose profiles in two phantoms exposed to the epithermal neutron beam at the BMRR. These measurements were performed as a preparatory step to the commencement of human clinical trials in progress at the BMRR.

  9. Solar radiation measurement project

    NASA Technical Reports Server (NTRS)

    Ioup, J. W.

    1981-01-01

    The Xavier solar radiation measurement project and station are described. Measurements of the total solar radiation on a horizontal surface from an Eppley pyranometer were collected into computer data files. Total radiation in watt hours was converted from ten minute intervals to hourly intervals. Graphs of this total radiation data are included. A computer program in Fortran was written to calculate the total extraterrestrial radiation on a horizontal surface for each day of the month. Educational and social benefits of the project are cited.

  10. Airdata Measurement and Calibration

    NASA Technical Reports Server (NTRS)

    Haering, Edward A., Jr.

    1995-01-01

    This memorandum provides a brief introduction to airdata measurement and calibration. Readers will learn about typical test objectives, quantities to measure, and flight maneuvers and operations for calibration. The memorandum informs readers about tower-flyby, trailing cone, pacer, radar-tracking, and dynamic airdata calibration maneuvers. Readers will also begin to understand how some data analysis considerations and special airdata cases, including high-angle-of-attack flight, high-speed flight, and nonobtrusive sensors are handled. This memorandum is not intended to be all inclusive; this paper contains extensive reference and bibliography sections.

  11. Measurements of microlens performance

    NASA Technical Reports Server (NTRS)

    Shough, D.; Herman, B.; Gal, George

    1993-01-01

    We present results of laboratory evaluations of several microlens types that have been designed and fabricated at the Lockheed Research and Development Division. The microlenses include wideband and dispersive types, in isolation and in arrays, and fabricated with binary or grayscale methods. Different lens pixel geometries are considered, including square, hexagonal, and skewed microlenses. We describe our micro-optics laboratory testbed which has been designed for the evaluation of individual lenslets or 2D arrays at selected spectral wavelengths. Measurement capabilities include focal length, point-spread functions, wavefront quality, and modulation transfer functions. Our present effort focuses on the results of point spread function measurements and their comparison with design predictions.

  12. Remote measurement of pollution

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A summary of the major conclusions and recommendations developed by the panels on gaseous air pollution, water pollution, and particulate air pollution is presented. It becomes evident that many of the trace gases are amenable to remote sensing; that certain water pollutants can be measured by remote techniques, but their number is limited; and that a similar approach to the remote measurement of specific particulate pollutants will follow only after understanding of their physical, chemical, and radiative properties is improved. It is also clear that remote sensing can provide essential information in all three categories that can not be obtained by any other means.

  13. Magnetotelluric measurements in Antarctica

    NASA Astrophysics Data System (ADS)

    Trivedi, N. B.; Padilha, A. L.; Barbosa, M. J. F.

    1986-11-01

    In the period of 2/14/86 to 3/7/86, during the 4th Brazilian Scientific Expedition to Antarctica, organized through the CIRM (Comissao Interministerial para Recursos do Mar), Station Commander Ferraz, (62 deg 5 min S, 58 deg 23.5 min W), magnetotelluric measurements were accomplished in 120 second intervals for DC. This measurement complemented the former, accomplished in the preceeding year between 20 and 400 seconds and although it presented excellent agreement in the overlapping intervals, it was a difficult interpretation. A Hilbert transformation technique was utilized for solving this problem, which brought to mind similar obtained resistivity values. The preliminary results encountered were presented and discussed.

  14. Measuring tissue oxygenation

    NASA Technical Reports Server (NTRS)

    Soyemi, Olusola O. (Inventor); Soller, Babs R. (Inventor); Yang, Ye (Inventor)

    2009-01-01

    Methods and systems for calculating tissue oxygenation, e.g., oxygen saturation, in a target tissue are disclosed. In some embodiments, the methods include: (a) directing incident radiation to a target tissue and determining reflectance spectra of the target tissue by measuring intensities of reflected radiation from the target tissue at a plurality of radiation wavelengths; (b) correcting the measured intensities of the reflectance spectra to reduce contributions thereto from skin and fat layers through which the incident radiation propagates; (c) determining oxygen saturation in the target tissue based on the corrected reflectance spectra; and (d) outputting the determined value of oxygen saturation.

  15. Measurement Space Drill Support

    DTIC Science & Technology

    2015-08-30

    TRAC-M-TR-15-026 30 AUG 2015 Measurement Space Drill Support TRADOC Analysis Center 700 Dyer Road Monterey, California 93943-0692 This study cost the...Space Drill Support LTC Michael D. Teter MAJ Adam Haupt TRADOC Analysis Center 700 Dyer Road Monterey, California 93943-0692 DISTRIBUTION STATEMENT...include area code) Standard Form 298 (Re . 8-98)v Prescribed by ANSI Std. Z39.18 08-30-2015 Technical Report AUG 14 - MAY 15 Measurement Space Drill

  16. Precise Measurement for Manufacturing

    NASA Technical Reports Server (NTRS)

    2003-01-01

    A metrology instrument known as PhaseCam supports a wide range of applications, from testing large optics to controlling factory production processes. This dynamic interferometer system enables precise measurement of three-dimensional surfaces in the manufacturing industry, delivering speed and high-resolution accuracy in even the most challenging environments.Compact and reliable, PhaseCam enables users to make interferometric measurements right on the factory floor. The system can be configured for many different applications, including mirror phasing, vacuum/cryogenic testing, motion/modal analysis, and flow visualization.

  17. Measurement of visual motion

    SciTech Connect

    Hildreth, E.C.

    1984-01-01

    This book examines the measurement of visual motion and the use of relative movement to locate the boundaries of physical objects in the environment. It investigates the nature of the computations that are necessary to perform this analysis by any vision system, biological or artificial. Contents: Introduction. Background. Computation of the Velocity Field. An Algorithm to Compute the Velocity Field. The Computation of Motion Discontinuities. Perceptual Studies of Motion Measurement. The Psychophysics of Discontinuity Detection. Neurophysiological Studies of Motion. Summary and Conclusions. References. Author and Subject Indexes.

  18. SBC Dark Current Measurement

    NASA Astrophysics Data System (ADS)

    Ogaz, Sara

    2013-10-01

    This takes a series of SBC dark measurements over a continuous period of about 6 hours {4 orbits}. The aim is to collect dark images during an extended SBC on-time. Earlier measurements indicate that the dark current increases with SBC on-time and may also be increasing with overall SBC use. The 6-hour time matches the longest time used by any observer. As with all SBC observations this needs continuous SAA free time.This program is executed once per cycle. The last exposures were taken in Mar 2013 under Program 13161.

  19. Creep Measurement Video Extensometer

    NASA Technical Reports Server (NTRS)

    Jaster, Mark; Vickerman, Mary; Padula, Santo, II; Juhas, John

    2011-01-01

    Understanding material behavior under load is critical to the efficient and accurate design of advanced aircraft and spacecraft. Technologies such as the one disclosed here allow accurate creep measurements to be taken automatically, reducing error. The goal was to develop a non-contact, automated system capable of capturing images that could subsequently be processed to obtain the strain characteristics of these materials during deformation, while maintaining adequate resolution to capture the true deformation response of the material. The measurement system comprises a high-resolution digital camera, computer, and software that work collectively to interpret the image.

  20. Measuring Thermoforming Behaviour

    NASA Astrophysics Data System (ADS)

    Michaeli, W.; Hopmann, C.; Ederleh, L.; Begemann, M.

    2011-05-01

    Thermoforming is the process of choice for manufacturing thin-gauge or large-area parts for packaging or technical applications. The process allows low-weight parts to be produced rapidly and economically from thermoplastic semi-finished products. A technical and consequently economical problem is the choice of the right material in combination with the thermoformability of the product. The prediction of thermoformability includes the aspired product features and geometry and defined wall thickness distributions, depending on the specific stretchability of the semifinished product. In practice, thermoformability is estimated by empirical tests with the particular semi-finished product using e.g. staged pyramidal moulds or model cars. With this method, it still cannot be ensured that the product can be thermoformed with the intended properties. A promising alternative is the forming simulation using finite element analysis (FEA). For the simulation, it is necessary to describe the material behaviour using defined material models and the appropriate parameters. Therefore, the stress-/strain-behaviour of the semi-finished product under defined conditions is required. There are several, entirely different measurement techniques used in industry and at research facilities. This paper compares a choice of different measurement techniques to provide an objective basis for future work and research. The semi-finished products are examined with the Membrane-Inflation-Rheometer (MIR), an equibiaxial strain rheometer. A flat sample is heated to the desired temperature in silicone oil. During the measurement, a servohydraulic linear drive advances a piston, thus displacing the hot silicone oil and inflating the specimen to form a sphere. Further measurements are carried out with the Karo IV Laboratory Stretching Machine at Brückner Maschinenbau GmbH & Co. KG, Siegsdorf, Germany. The samples are heated using hot air. During the biaxial stretching, the resulting forces at the

  1. Color measurement and discrimination

    NASA Technical Reports Server (NTRS)

    Wandell, B. A.

    1985-01-01

    The present investigation is concerned with new results which show that for test lights with slow temporal modulations, and thus little effect on the luminance system, the vector-difference hypothesis represents an adequate characterization of discrimination data. It is pointed out that for certain experimental conditions color measurements can be successfully extended to include a difference measure which predicts the discriminability of pairs of lights. When discrimination depends principally on opponent-channel responses, discrimination thresholds can be predicted from the detection contour alone. Attention is given to discriminations with a 6-Hz Gabor function, the categorization of stimulus regions, and the nature of the visual mechanisms.

  2. Polarizability Measurements at MAMI

    NASA Astrophysics Data System (ADS)

    Hornidge, David; A2 Collaboration at MAMI Collaboration

    2017-01-01

    A central problem of modern physics research is the solution to QCD in the non-perturbative regime. One method of testing QCD in this low-energy region is by measuring certain structure constants of hadrons-called polarizabilities-that show particular promise of allowing a direct connection to the underlying quark/gluon dynamics through comparison to modern QCD-inspired model calculations, and to solutions of QCD done computationally on the lattice. This talk will give an overview of recent and upcoming measurements to obtain the polarizabilities of both the proton and neutron.

  3. [Measuring blood pressure].

    PubMed

    Estrada Reventos, Dolors; Pujol Navarro, Ester

    2008-09-01

    High blood pressure is one of the main factors which lead to cardiovascular cerebral-vascular and kidney diseases; therefore, nursing professionals should have enough basic knowledge to enable them to carry out a precocious diagnosis and correct follow-up procedures. Although students in nursing schools are taught how to correctly measure blood pressure, often this teaching does not meet the recommendations provided by different national and international guidelines. Thus it is important to know how to use the correct methodology to measure blood pressure.

  4. The measurement of happiness.

    PubMed

    Helm, D T

    2000-09-01

    Happiness has been defined either as a broad notion of how one feels about their life in general or as an emotional or affective state. Depending on the way researchers define the concept, there have been variable attempts at measurement. With decades of research, we have a better understanding of how to measure the happiness of others. A combination of quantitative and qualitative methods appears to be most productive. If we assume that individuals with disabilities are made happy in the same way as are people without disabilities, then we have a good idea of how to proceed with practical and policy matters.

  5. Polarizability Measurements at MAMI

    NASA Astrophysics Data System (ADS)

    Hornidge, David; A2 Collaboration at MAMI Collaboration

    2016-09-01

    A central problem of modern physics research is the solution to QCD in the non-perturbative regime. One method of testing QCD in this low-energy region is by measuring certain structure constants of hadrons-called polarizabilities-that show particular promise of allowing a direct connection to the underlying quark/gluon dynamics through comparison to modern QCD-inspired model calculations, and to solutions of QCD done computationally on the lattice. This talk will give an overview of recent and upcoming measurements at the Mainz Microtron to obtain the polarizabilities of both the proton and neutron.

  6. Disability Experience and Measurement.

    PubMed

    Verbrugge, Lois M

    2016-10-01

    Top themes of international research on disability in the past three decades are discussed: disability dynamics, buffers and barriers for disability, disability trends, and disability among very old persons. Each theme is highlighted by research examples. Turning to measurement, I discuss traditional measures of disability, new longer and shorter ones, and composites like disability-free life expectancy, noting their merits. Contemporary models of disability are presented, ranging from visual images to formal theories. The article ends on how scientists can facilitate movement of disability science into health care practice and policy.

  7. Measuring Educational Sustainability

    ERIC Educational Resources Information Center

    Selvanathan, Rani G.

    2013-01-01

    There are many definitions that are attributable to the meaning of sustainability. Sustainability can be viewed as long-lasting, effective result of a project, venture, action, or investment without consuming additional future resources. Because of the wide nature of its applicability, a universal measure of sustainability is hard to come by. This…

  8. Underwater measuring gage

    SciTech Connect

    Lockhart, J.L.

    1989-06-13

    This patent describes a device for remotely measuring the diameter of wire rope. The device includes a linear variable differential transducer, a mechanism to guide and clamp the rope in relation to the anvil of the transducer, an elongated handle for manually manipulating the transducer and the guide and clamp mechanism.

  9. Underwater measuring gage

    SciTech Connect

    Lockhart, James L.

    1989-01-01

    A device for remotely measuring the diameter of wire rope. The device includes a linear variable differential tansducer, a mechanism to guide and clamp the rope in relation to the anvil of the transducer, an elongated handle for manually manipulating the transducer and the guide and clamp mechanism.

  10. First Measurement of $\

    SciTech Connect

    Palomino Gallo, Jose Luis

    2012-12-01

    Understanding of the $\\pi^0$ production via anti-neutrino-nucleus charged current interaction in the neutrino energy region of 1-10 GeV is essential for neutrino oscillation experiments. In this thesis, we present a measurement of charged current $\\pi^0$ production from anti-muon neutrinos scattering on a polystyrene scintillator (CH) target in the MINER$\

  11. Precise measurement of planeness.

    PubMed

    Schulz, G; Schwider, J

    1967-06-01

    Interference methods are reviewed-particularly those developed at the German Academy of Sciences in Berlin-with which the deviations of an optically flat surface from the ideal plane can be measured with a high degree of exactness. One aid to achieve this is the relative methods which measure the differences in planeness between two surfaces. These are then used in the absolute methods which determine the absolute planeness of a surface. This absolute determination can be effected in connection with a liquid surface, or (as done by the authors) only by suitable evaluation of relative measurements between unknown plates in various positional combinations. Experimentally, one uses two- or multiple-beam interference fringes of equal thickness(1) or of equal inclination. The fringes are observed visually, scanned, or photographed, and in part several wavelengths or curves of equal density (Aquidensiten) are employed. The survey also brings the following new methods: a relative method, where, with the aid of fringes of superposition, the fringe separation is subdivided equidistantly thus achieving an increase of measuring precision, and an absolute method which determines the deviations of a surface from ideal planeness along arbitrary central sections, without a liquid surface, from four relative interference photographs.

  12. Measurement of Peroxiredoxin Activity

    PubMed Central

    Nelson, Kimberly J.; Parsonage, Derek

    2011-01-01

    Peroxiredoxins are cysteine-dependent peroxidases that react with hydrogen peroxide, larger hydroperoxide substrates, and peroxynitrite. Protocols are provided to measure Prx activity with peroxide by 1) a coupled reaction with NADPH, thioredoxin reductase, and thioredoxin, 2) the direct monitoring of thioredoxin oxidation, 3) competition with horseradish peroxidase, and 4) peroxide consumption using the FOX assay. PMID:21818753

  13. Understanding Educational Measurement.

    ERIC Educational Resources Information Center

    McDaniel, Ernest

    This book is designed to introduce education students to the essentials of measurement and evaluation. It focuses on the topics essential to effective classroom teaching and treats these topics in a way that emphasizes the human context that surrounds and guides their use. The book is organized into three main sections. The first is understanding…

  14. Color measurement and discrimination

    NASA Technical Reports Server (NTRS)

    Wandell, B. A.

    1985-01-01

    Theories of color measurement attempt to provide a quantative means for predicting whether two lights will be discriminable to an average observer. All color measurement theories can be characterized as follows: suppose lights a and b evoke responses from three color channels characterized as vectors, v(a) and v(b); the vector difference v(a) - v(b) corresponds to a set of channel responses that would be generated by some real light, call it *. According to theory a and b will be discriminable when * is detectable. A detailed development and test of the classic color measurement approach are reported. In the absence of a luminance component in the test stimuli, a and b, the theory holds well. In the presence of a luminance component, the theory is clearly false. When a luminance component is present discrimination judgements depend largely on whether the lights being discriminated fall in separate, categorical regions of color space. The results suggest that sensory estimation of surface color uses different methods, and the choice of method depends upon properties of the image. When there is significant luminance variation a categorical method is used, while in the absence of significant luminance variation judgments are continuous and consistant with the measurement approach.

  15. Human perspiration measurement.

    PubMed

    Ohhashi, T; Sakaguchi, M; Tsuda, T

    1998-11-01

    We review various methods developed for human perspiration measurement and their physiological applications, with special reference to the performance and application of a new home-made ratemeter and instrumentation with a microscope. Many kinds of humidity sensor based on humidity-sensitive electrical properties have been investigated and placed on the market. Recently a capacitive thin-film humidity sensor was constructed and confirmed to be one of the best humidity sensors for accurately and quickly detecting changes in the relative humidity of gas-flow perfused through a ventilated chamber for human perspiration measurement. In this paper we also introduce a new home-made ratemeter with a capacitive humidity sensor, the electrical output of which is not disturbed by changes in ambient temperature, and new instrumentation for directly observing drops of sweat secreted from eccrine glands in human skin and simultaneously measuring the change in amount of perspiration at the same area of skin. Finally, we review physiological applications of the methods for measuring human palmar perspiration including emotional sweating.

  16. Inquiry Skill Measures

    ERIC Educational Resources Information Center

    Nelson, Miles A.; Abraham, Eugene C.

    1973-01-01

    Describes the development and testing of an instrument for use at the eighth grade level to measure four science processes: observation, inference, verification, and classification. Indicates that the two forms of the instrument are average in reliability and high in factor validity. (CC)

  17. DEMONSTRATION PLAN FIELD MEASUREMENT ...

    EPA Pesticide Factsheets

    The demonstration of innovative field measurement devices for total petroleum hydrocarbons (TPH) in soil is being conducted under the U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation Program in June 2000 at the Navy Base Ventura County site in Port Hueneme, California. The primary purpose of the demonstration is to evaluate innovative field measurement devices for TPH in soil based on their performance and cost as compared to a conventional, off-site laboratory analytical method. The seven field measurement devices listed below will be demonstrated. CHEMetrics, Inc.'s, RemediAidTm Total Petroleum Hydrocarbon Starter Kit Wilks Enterprise, Inc.'s, Infracal' TOG/TPH Analyzer, Models CVH and HATR-T Horiba Instruments, Incorporated's, OCMA-350 Oil Content Analyzer Dexsil' Corporation's PetroFLAGTm Hydrocarbon Test Kit for Soil Environmental Systems Corporation's Synchronous Scanning Luminoscope siteLAB@ Corporation's Analytical Test Kit UVF-3 I OOA Strategic Diagnostics, Inc.'s, EnSys Petro Test System This demonstration plan describes the procedures that will be used to verify the performance and cost of each field measurement device. The plan incorporates the quality assurance and quality control elements needed to generate data of sufficient quality to document each device's performance and cost. A separate innovative technology verification report (ITVR) will be prepared for each device. The ITVRs will present the demonstratio

  18. Pollution Measuring System

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Research Ventures, Inc.'s visiplume is a portable, microprocessor-controlled air pollution monitor for measuring sulfur dioxide emissions from fossil fuel-fired power plants, and facilities that manufacture sulfuric acid. It observes smokestack plumes at a distance from the stack obviating the expense and difficulty of installing sample collectors in each stack and later analyzing the samples.

  19. Instrument Measures Ocular Counterrolling

    NASA Technical Reports Server (NTRS)

    Levitan, Barry M.; Reschke, Millard F.; Spector, Lawrence N.

    1991-01-01

    Compact, battery-powered, noninvasive unit replaces several pieces of equipment and operator. Instrument that looks like pair of goggles with small extension box measures ocular counterrotation. Called "otolith tilt-translation reinterpretation" (OTTR) goggles, used in studies of space motion sickness. Also adapted to use on Earth and determine extent of impairment in patients who have impaired otolith functions.

  20. Benchmarking and Performance Measurement.

    ERIC Educational Resources Information Center

    Town, J. Stephen

    This paper defines benchmarking and its relationship to quality management, describes a project which applied the technique in a library context, and explores the relationship between performance measurement and benchmarking. Numerous benchmarking methods contain similar elements: deciding what to benchmark; identifying partners; gathering…