Science.gov

Sample records for addition direct measurements

  1. EPA Directs Additional Safety Measures for San Jacinto River Waste Pits Superfund Site

    EPA Pesticide Factsheets

    DALLAS - (Feb. 17, 2016) Today, the U.S. Environmental Protection Agency (EPA) announced new safety requirements for the temporary armored cap at the San Jacinto River Waste Pits Superfund Site in Harris County, Texas. EPA has directed both Internat

  2. Generalized additive regression models of discharge and mean velocity associated with direct-runoff conditions in Texas: Utility of the U.S. Geological Survey discharge measurement database

    USGS Publications Warehouse

    Asquith, William H.; Herrmann, George R.; Cleveland, Theodore G.

    2013-01-01

    A database containing more than 17,700 discharge values and ancillary hydraulic properties was assembled from summaries of discharge measurement records for 424 U.S. Geological Survey streamflow-gauging stations (stream gauges) in Texas. Each discharge exceeds the 90th-percentile daily mean streamflow as determined by period-of-record, stream-gauge-specific, flow-duration curves. Each discharge therefore is assumed to represent discharge measurement made during direct-runoff conditions. The hydraulic properties of each discharge measurement included concomitant cross-sectional flow area, water-surface top width, and reported mean velocity. Systematic and statewide investigation of these data in pursuit of regional models for the estimation of discharge and mean velocity has not been previously attempted. Generalized additive regression modeling is used to develop readily implemented procedures by end-users for estimation of discharge and mean velocity from select predictor variables at ungauged stream locations. The discharge model uses predictor variables of cross-sectional flow area, top width, stream location, mean annual precipitation, and a generalized terrain and climate index (OmegaEM) derived for a previous flood-frequency regionalization study. The mean velocity model uses predictor variables of discharge, top width, stream location, mean annual precipitation, and OmegaEM. The discharge model has an adjusted R-squared value of about 0.95 and a residual standard error (RSE) of about 0.22 base-10 logarithm (cubic meters per second); the mean velocity model has an adjusted R-squared value of about 0.67 and an RSE of about 0.063 fifth root (meters per second). Example applications and computations using both regression models are provided. - See more at: http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29HE.1943-5584.0000635#sthash.jhGyPxgZ.dpuf

  3. Direct temperature measurement.

    PubMed

    Fessenden, P; Lee, E R; Samulski, T V

    1984-10-01

    Hyperthermia has little hope of progressing as a clinical modality without accurate assessment of the temperature distributions obtained. At the present time only direct, invasive temperature-measuring techniques are possible, posing severe limitations. Established techniques for clinical temperature measurement have developed over the past few years, and for both ultrasound and electromagnetic hyperthermia it is possible to get temperature-time profiles at a large number of spatial points. Position uncertainty, thermal conduction smearing, and artifactual heating limit the accuracy to about 0.2 degrees (electromagnetic) or 0.5 degrees (ultrasound), but this is probably less of a hindrance than the inadequate percentage of tumor and normal tissue volume for which achieved temperatures can be documented.

  4. Direct neutrino mass measurements

    NASA Astrophysics Data System (ADS)

    Drexlin, G.

    2008-11-01

    Direct neutrino mass measurements are based on high precision spectroscopy studies close to the kinematic end-point of low-energy β-emitters such as 3H and 187Re. Relying only on energy-momentum conservation in β-decay, they offer the only model-independent method to measure the absolute ν-mass scale with sub-eV sensitivity. The two most sensitive detection principles, electrostatic retarding spectrometers and microbolometers, are complementary to each other, and two experiments are currently being prepared to explore ν-masses down to m(ν) = 200 meV. β-spectroscopy will thus allow to constrain the role of neutrino hot dark matter in structure formation, as well as to explore the parameter region of ν-mass scenarios with quasi-degenerate pattern. The MARE project will investigate the β-decay of 187Re with bolometers based on metallic Re and AgReO4 in a two-staged approach: in a phase-I set-up a sensitivity of m(ν) = 2 eV is expected, forming the basis for a later sub-eV phase-II. The Karlsruhe Tritium Neutrino (KATRIN) experiment is currently being set-up on the site of Tritium Laboratory at KIT. The experiment will combine an ultra-luminous windowless gaseous tritium source with a high resolution electrostatic spectrometer and offer an unprecedented precision in β-decay studies, pushing this technique to its technological limits. First KATRIN measurements with 3H after successful system integration are expected for mid-2011. This contribution gives a status report and outlook for both experiments and discusses the impact of direct ν-mass experiments on astroparticle physics.

  5. Direct neutrino mass measurements

    NASA Astrophysics Data System (ADS)

    Weinheimer, Christian

    2013-03-01

    Direct neutrino mass experiments are complementary to searches for neutrinoless double β-decay and to analyses of cosmological data. The previous tritium beta decay experiments at Mainz and at Troitsk have achieved upper limits on the neutrino mass of about 2 eV/c2 . The KATRIN experiment under construction will improve the neutrino mass sensitivity down to 200 meV/c2 by increasing strongly the statistics and—at the same time—reducing the systematic uncertainties. Huge improvements have been made to operate the system extremely stably and at very low background rate. The latter comprises new methods to reject secondary electrons from the walls as well as to avoid and to eject electrons stored in traps. As an alternative to tritium β-decay experiments cryo-bolometers investigating the endpoint region of 187Re β-decay or the electron capture of 163Ho are being developed. This article briefly reviews the current status of the direct neutrino mass measurements.

  6. 5 CFR 960.108 - Additional rules and directives.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Additional rules and directives. 960.108 Section 960.108 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EXECUTIVE BOARDS § 960.108 Additional rules and directives. The Director may...

  7. 5 CFR 960.108 - Additional rules and directives.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Additional rules and directives. 960.108 Section 960.108 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EXECUTIVE BOARDS § 960.108 Additional rules and directives. The Director may...

  8. 5 CFR 960.108 - Additional rules and directives.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Additional rules and directives. 960.108 Section 960.108 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EXECUTIVE BOARDS § 960.108 Additional rules and directives. The Director may...

  9. 5 CFR 960.108 - Additional rules and directives.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Additional rules and directives. 960.108 Section 960.108 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EXECUTIVE BOARDS § 960.108 Additional rules and directives. The Director...

  10. Direct Measurement of Intracellular Pressure

    PubMed Central

    Petrie, Ryan J.; Koo, Hyun

    2014-01-01

    A method to directly measure the intracellular pressure of adherent, migrating cells is described in the Basic Protocol. This approach is based on the servo-null method where a microelectrode is introduced into the cell to directly measure the physical pressure of the cytoplasm. We also describe the initial calibration of the microelectrode as well as the application of the method to cells migrating inside three-dimensional (3D) extracellular matrix (ECM). PMID:24894836

  11. 40 CFR 412.47 - Additional measures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Additional measures. 412.47 Section 412.47 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CONCENTRATED ANIMAL FEEDING OPERATIONS (CAFO) POINT SOURCE CATEGORY Swine, Poultry, and Veal...

  12. 40 CFR 412.37 - Additional measures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Additional measures. 412.37 Section 412.37 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CONCENTRATED ANIMAL FEEDING OPERATIONS (CAFO) POINT SOURCE CATEGORY Dairy Cows and Cattle Other...

  13. 40 CFR 412.47 - Additional measures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Additional measures. 412.47 Section 412.47 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CONCENTRATED ANIMAL FEEDING OPERATIONS (CAFO) POINT SOURCE CATEGORY Swine, Poultry, and Veal...

  14. 40 CFR 412.47 - Additional measures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 30 2012-07-01 2012-07-01 false Additional measures. 412.47 Section 412.47 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CONCENTRATED ANIMAL FEEDING OPERATIONS (CAFO) POINT SOURCE CATEGORY Swine, Poultry, and Veal...

  15. 40 CFR 412.47 - Additional measures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 29 2014-07-01 2012-07-01 true Additional measures. 412.47 Section 412.47 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CONCENTRATED ANIMAL FEEDING OPERATIONS (CAFO) POINT SOURCE CATEGORY Swine, Poultry, and Veal...

  16. 40 CFR 412.47 - Additional measures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Additional measures. 412.47 Section 412.47 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CONCENTRATED ANIMAL FEEDING OPERATIONS (CAFO) POINT SOURCE CATEGORY Swine, Poultry, and Veal...

  17. 76 FR 41687 - Food Additives Permitted for Direct Addition to Food for Human Consumption; Hydroxypropyl Cellulose

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-15

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Part 172 Food Additives Permitted for Direct Addition to Food for Human Consumption; Hydroxypropyl Cellulose AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is amending the food additive...

  18. Surface texture measurement for additive manufacturing

    NASA Astrophysics Data System (ADS)

    Triantaphyllou, Andrew; Giusca, Claudiu L.; Macaulay, Gavin D.; Roerig, Felix; Hoebel, Matthias; Leach, Richard K.; Tomita, Ben; Milne, Katherine A.

    2015-06-01

    The surface texture of additively manufactured metallic surfaces made by powder bed methods is affected by a number of factors, including the powder’s particle size distribution, the effect of the heat source, the thickness of the printed layers, the angle of the surface relative to the horizontal build bed and the effect of any post processing/finishing. The aim of the research reported here is to understand the way these surfaces should be measured in order to characterise them. In published research to date, the surface texture is generally reported as an Ra value, measured across the lay. The appropriateness of this method for such surfaces is investigated here. A preliminary investigation was carried out on two additive manufacturing processes—selective laser melting (SLM) and electron beam melting (EBM)—focusing on the effect of build angle and post processing. The surfaces were measured using both tactile and optical methods and a range of profile and areal parameters were reported. Test coupons were manufactured at four angles relative to the horizontal plane of the powder bed using both SLM and EBM. The effect of lay—caused by the layered nature of the manufacturing process—was investigated, as was the required sample area for optical measurements. The surfaces were also measured before and after grit blasting.

  19. 76 FR 16285 - Food Additives Permitted for Direct Addition to Food for Human Consumption; Bacteriophage...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-23

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Part 172 (formerly Docket No. 2002F-0316) Food Additives Permitted for Direct Addition to Food for Human Consumption; Bacteriophage Preparation AGENCY: Food and Drug Administration, HHS. ACTION: Final rule; response to objections and denial of requests...

  20. Directed energy deflection laboratory measurements

    NASA Astrophysics Data System (ADS)

    Brashears, Travis; Lubin, Phillip; Hughes, Gary B.; Meinhold, Peter; Suen, Jonathan; Batliner, Payton; Motta, Caio; Griswold, Janelle; Kangas, Miikka; Johansson, Isbella; Alnawakhtha, Yusuf; Prater, Kenyon; Lang, Alex; Madajian, Jonathan

    2015-09-01

    We report on laboratory studies of the effectiveness of directed energy planetary defense as a part of the DESTAR (Directed Energy System for Targeting of Asteroids and exploRation) program. DE-STAR [1][5][6] and DE-STARLITE [2][5][6] are directed energy "stand-off" and "stand-on" programs, respectively. These systems consist of a modular array of kilowatt-class lasers powered by photovoltaics, and are capable of heating a spot on the surface of an asteroid to the point of vaporization. Mass ejection, as a plume of evaporated material, creates a reactionary thrust capable of diverting the asteroid's orbit. In a series of papers, we have developed a theoretical basis and described numerical simulations for determining the thrust produced by material evaporating from the surface of an asteroid [1][2][3][4][5][6]. In the DE-STAR concept, the asteroid itself is used as the deflection "propellant". This study presents results of experiments designed to measure the thrust created by evaporation from a laser directed energy spot. We constructed a vacuum chamber to simulate space conditions, and installed a torsion balance that holds an "asteroid" sample. The sample is illuminated with a fiber array laser with flux levels up to 60 MW/m2 which allows us to simulate a mission level flux but on a small scale. We use a separate laser as well as a position sensitive centroid detector to readout the angular motion of the torsion balance and can thus determine the thrust. We compare the measured thrust to the models. Our theoretical models indicate a coupling coefficient well in excess of 100 μN/Woptical, though we assume a more conservative value of 80 μN/Woptical and then degrade this with an optical "encircled energy" efficiency of 0.75 to 60 μN/Woptical in our deflection modeling. Our measurements discussed here yield about 45 μN/Wabsorbed as a reasonable lower limit to the thrust per optical watt absorbed.

  1. Gravitational spectra from direct measurements

    NASA Technical Reports Server (NTRS)

    Wagner, C. A.; Colombo, O. L.

    1978-01-01

    A simple rapid method is described for determining the spectrum of a surface field from harmonic analysis of direct measurements along great circle arcs. The method is shown to give excellent overall trends to very high degree from even a few short arcs of satellite data. Three examples are taken with perfect measurements of satellite tracking over a planet made up of hundreds of point-masses using (1) altimetric heights from a low orbiting spacecraft, (2) velocity residuals between a low and a high satellite in circular orbits, and (3) range-rate data between a station at infinity and a satellite in highly eccentric orbit. In particular, the smoothed spectrum of the Earth's gravitational field is determined to about degree 400(50 km half wavelength) from 1 D x 1 D gravimetry and the equivalent of 11 revolutions of Geos 3 and Skylab altimetry. This measurement shows there is about 46 cm of geoid height remaining in the field beyond degree 180.

  2. Direct observation of lubricant additives using tomography techniques

    NASA Astrophysics Data System (ADS)

    Chen, Yunyun; Sanchez, Carlos; Parkinson, Dilworth Y.; Liang, Hong

    2016-07-01

    Lubricants play important roles in daily activities such as driving, walking, and cooking. The current understanding of mechanisms of lubrication, particularly in mechanical systems, has been limited by the lack of capability in direct observation. Here, we report an in situ approach to directly observe the motion of additive particles in grease under the influence of shear. Using the K-edge tomography technique, it is possible to detect particular additives in a grease and observe their distribution through 3D visualization. A commercial grease as a reference was studied with and without an inorganic additive of Fe3O4 microparticles. The results showed that it was possible to identify these particles and track their movement. Under a shear stress, Fe3O4 particles were found to adhere to the edge of calcium complex thickeners commonly used in grease. Due to sliding, the grease formed a film with increased density. This approach enables in-line monitoring of a lubricant and future investigation in mechanisms of lubrication.

  3. Direct observation of lubricant additives using tomography techniques

    SciTech Connect

    Chen, Yunyun; Sanchez, Carlos; Parkinson, Dilworth Y.; Liang, Hong

    2016-07-25

    Lubricants play important roles in daily activities such as driving, walking, and cooking. The current understanding of mechanisms of lubrication, particularly in mechanical systems, has been limited by the lack of capability in direct observation. Here, we report an in situ approach to directly observe the motion of additive particles in grease under the influence of shear. Using the K-edge tomography technique, it is possible to detect particular additives in a grease and observe their distribution through 3D visualization. A commercial grease as a reference was studied with and without an inorganic additive of Fe{sub 3}O{sub 4} microparticles. The results showed that it was possible to identify these particles and track their movement. Under a shear stress, Fe{sub 3}O{sub 4} particles were found to adhere to the edge of calcium complex thickeners commonly used in grease. Due to sliding, the grease formed a film with increased density. This approach enables in-line monitoring of a lubricant and future investigation in mechanisms of lubrication.

  4. Additional sampling directions improve detection range of wireless radiofrequency probes

    PubMed Central

    Mada, Marius; Carpenter, T. Adrian; Sawiak, Stephen J.; Williams, Guy B.

    2015-01-01

    Purpose While MRI is enhancing our knowledge about the structure and function of the human brain, subject motion remains a problem in many clinical applications. Recently, the use of wireless radiofrequency markers with three one‐dimensional (1D) navigators for prospective correction was demonstrated. This method is restricted in the range of motion that can be corrected, however, because of limited information in the 1D readouts. Methods Here, the limitation of techniques for disambiguating marker locations was investigated. It was shown that including more sampling directions extends the tracking range for head rotations. The efficiency of trading readout resolution for speed was explored. Results Tracking of head rotations was demonstrated from −19.2 to 34.4°, −2.7 to 10.0°, and −60.9 to 70.9° in the x‐, y‐, and z‐directions, respectively. In the presence of excessive head motion, the deviation of marker estimates from SPM8 was reduced by 17.1% over existing three‐projection methods. This was achieved by using an additional seven directions, extending the time needed for readouts by a factor of 3.3. Much of this increase may be circumvented by reducing resolution, without compromising accuracy. Conclusion Including additional sampling directions extends the range in which markers can be used, for patients who move a lot. Magn Reson Med 76:913–918, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:26418189

  5. Direct Measurements of Skin Friction

    NASA Technical Reports Server (NTRS)

    Dhawan, Satish

    1953-01-01

    A device has been developed to measure local skin friction on a flat plate by measuring the force exerted upon a very small movable part of the surface of the flat plate. These forces, which range from about 1 milligram to about 100 milligrams, are measured by means of a reactance device. The apparatus was first applied to measurements in the low-speed range, both for laminar and turbulent boundary layers. The measured skin-friction coefficients show excellent agreement with Blasius' and Von Karman's results. The device was then applied to high-speed subsonic flow and the turbulent-skin-friction coefficients were determined up to a Mach number of about 0.8. A few measurements in supersonic flow were also made. This paper describes the design and construction of the device and the results of the measurements.

  6. Direct measurements of neutrino mass

    SciTech Connect

    Robertson, R.G.H.

    1991-01-01

    Some recent developments in the experimental search for neutrino mass are discussed. New data from Los Alamos on the electron neutrino mass as measured in tritium beta decay give an upper limit of 9.3 eV at the 95% confidence level. This result is not consistent with the long-standing ITEP result of 26(5) eV within a model-independent'' range of 17 to 40 eV. It now appears that the electron neutrino is not sufficiently massive to close the universe by itself. Hime and Jelley report finding new evidence for a 17-keV neutrino in the {Beta} decay of {sup 35}S and {sup 63}Ni. Many other experiments are being reported and the situation is still unresolved. 56 refs., 1 fig., 3 tabs.

  7. Directional spectral emissivity measurement system

    NASA Technical Reports Server (NTRS)

    Halyo, Nesim (Inventor); Pandey, Dhirendra K. (Inventor)

    1992-01-01

    Apparatus and process for determining the emissivity of a test specimen including an integrated sphere having two concentric walls with a coolant circulating therebetween, and disposed within a chamber which may be under ambient, vacuum or inert gas conditions. A reference sample is disposed within the sphere with a monochromatic light source in optical alignment therewith. A pyrometer is in optical alignment with the test sample for obtaining continuous test sample temperature measurements during a test. An arcuate slit port is provided through the spaced concentric walls of the integrating sphere with a movable monochromatic light source extending through and movable along the arcuate slit port. A detector system extends through the integrating sphere for continuously detecting an integrated signal indicative of all radiation within its field of view, as a function of the emissivity of the test specimen at various temperatures and various angle position of the monochromatic light source. A furnace for heating the test sample to approximately 3000 K. and control mechanism for transferring the heated sample from the furnace to the test sample port in the integrating sphere is also contained within the chamber.

  8. Chemistry of Food Additives: Direct and Indirect Effects.

    ERIC Educational Resources Information Center

    Pauli, George H.

    1984-01-01

    The primary component(s), impurities, and degradation products of polysorbate 80, nitrate and nitrite salts, and diethylpyrocarbonate (DEPC) are discussed. Safety considerations related to these food additives are also noted. The chick-edema factor which results from an additive in poultry feed is also discussed. (JN)

  9. Chemistry of Food Additives: Direct and Indirect Effects.

    ERIC Educational Resources Information Center

    Pauli, George H.

    1984-01-01

    The primary component(s), impurities, and degradation products of polysorbate 80, nitrate and nitrite salts, and diethylpyrocarbonate (DEPC) are discussed. Safety considerations related to these food additives are also noted. The chick-edema factor which results from an additive in poultry feed is also discussed. (JN)

  10. Measurement of additional shear during sludge conditioning and dewatering.

    PubMed

    Ormeci, Banu; Ahmad, Ayaz

    2009-07-01

    Optimum polymer dose is influenced both by the polymer demand of the sludge and the shear applied during conditioning. Sludge exposed to additional shear following conditioning will experience a decrease in cake solids concentration for the same polymer dose. Therefore, it is necessary to measure or quantify the additional shear in order to optimize the conditioning and dewatering. There is currently no direct or indirect method to achieve this. The main objective of this study was to develop a method based on torque rheology to measure the amount of shear that a sludge network experiences during conditioning and dewatering. Anaerobically digested sludge samples were exposed to increasing levels of mixing intensities and times, and rheological characteristics of samples were measured using a torque rheometer. Several rheological parameters were evaluated including the peak torque and totalized torque (area under the rheograms). The results of this study show that at the optimum polymer dose, a linear relationship exists between the applied shear and the area under the rheograms, and this relationship can be used to estimate an unknown amount of shear that the sludge was exposed to. The method is useful as a research tool to study the effect of shear on dewatering but also as an optimization tool in a dewatering automation system based on torque rheology.

  11. Direct laser additive fabrication system with image feedback control

    DOEpatents

    Griffith, Michelle L.; Hofmeister, William H.; Knorovsky, Gerald A.; MacCallum, Danny O.; Schlienger, M. Eric; Smugeresky, John E.

    2002-01-01

    A closed-loop, feedback-controlled direct laser fabrication system is disclosed. The feedback refers to the actual growth conditions obtained by real-time analysis of thermal radiation images. The resulting system can fabricate components with severalfold improvement in dimensional tolerances and surface finish.

  12. Food Additives Permitted for Direct Addition to Food for Human Consumption; Folic Acid. Final rule.

    PubMed

    2016-04-15

    The Food and Drug Administration (FDA or we) is amending the food additive regulations to provide for the safe use of folic acid in corn masa flour. We are taking this action in response to a food additive petition filed jointly by Gruma Corporation, Spina Bifida Association, March of Dimes Foundation, American Academy of Pediatrics, Royal DSM N.V., and National Council of La Raza.

  13. Sensitivity of directed networks to the addition and pruning of edges and vertices

    NASA Astrophysics Data System (ADS)

    Goltsev, A. V.; Timár, G.; Mendes, J. F. F.

    2017-08-01

    Directed networks have various topologically different extensive components, in contrast to a single giant component in undirected networks. We study the sensitivity (response) of the sizes of these extensive components in directed complex networks to the addition and pruning of edges and vertices. We introduce the susceptibility, which quantifies this sensitivity. We show that topologically different parts of a directed network have different sensitivity to the addition and pruning of edges and vertices and, therefore, they are characterized by different susceptibilities. These susceptibilities diverge at the critical point of the directed percolation transition, signaling the appearance (or disappearance) of the giant strongly connected component in the infinite size limit. We demonstrate this behavior in randomly damaged real and synthetic directed complex networks, such as the World Wide Web, Twitter, the Caenorhabditis elegans neural network, directed Erdős-Rényi graphs, and others. We reveal a nonmonotonic dependence of the sensitivity to random pruning of edges or vertices in the case of C. elegans and Twitter that manifests specific structural peculiarities of these networks. We propose the measurements of the susceptibilities during the addition or pruning of edges and vertices as a new method for studying structural peculiarities of directed networks.

  14. Directional emittance surface measurement system and process

    NASA Technical Reports Server (NTRS)

    Puram, Chith K. (Inventor); Daryabeigi, Kamran (Inventor); Wright, Robert (Inventor); Alderfer, David W. (Inventor)

    1994-01-01

    Apparatus and process for measuring the variation of directional emittance of surfaces at various temperatures using a radiometric infrared imaging system. A surface test sample is coated onto a copper target plate provided with selective heating within the desired incremental temperature range to be tested and positioned onto a precision rotator to present selected inclination angles of the sample relative to the fixed positioned and optically aligned infrared imager. A thermal insulator holder maintains the target plate on the precision rotator. A screen display of the temperature obtained by the infrared imager, and inclination readings are provided with computer calculations of directional emittance being performed automatically according to equations provided to convert selected incremental target temperatures and inclination angles to relative target directional emittance values. The directional emittance of flat black lacquer and an epoxy resin measurements obtained are in agreement with the predictions of the electromagnetic theory and with directional emittance data inferred from directional reflectance measurements made on a spectrophotometer.

  15. 77 FR 52228 - Food Additives Permitted for Direct Addition to Food for Human Consumption; Vitamin D2

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-29

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Part 172 Food Additives Permitted for Direct Addition to Food for Human Consumption; Vitamin D2 Bakers Yeast AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is amending the food additive...

  16. 21 CFR 172.5 - General provisions for direct food additives.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true General provisions for direct food additives. 172.5... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION General Provisions § 172.5 General provisions for direct food additives. (a...

  17. 21 CFR 172.5 - General provisions for direct food additives.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false General provisions for direct food additives. 172... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION General Provisions § 172.5 General provisions for direct food additives. (a...

  18. 21 CFR 172.5 - General provisions for direct food additives.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false General provisions for direct food additives. 172... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION General Provisions § 172.5 General provisions for direct food additives. (a...

  19. 21 CFR 172.5 - General provisions for direct food additives.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false General provisions for direct food additives. 172... (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION General Provisions § 172.5 General provisions for direct food additives. (a) Regulations prescribing conditions under which...

  20. 21 CFR 172.5 - General provisions for direct food additives.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false General provisions for direct food additives. 172... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION General Provisions § 172.5 General provisions for direct food additives. (a...

  1. Directivity measurements of the violin during performance

    NASA Astrophysics Data System (ADS)

    Hardy, Jean-François; Migneron, Jean-Gabriel

    2005-04-01

    Many studies have shown that directivity of musical instruments is significant for the perceived sound within the hall and for performer's ease of hearing each other. The directivity patterns explain in part the differences between many common or special orchestral stage plots. Measurements of the violin's directivity have been performed using an acoustical intensimetry procedure. The precise directivity characteristics of isolated tones have been compared with the mean directivity resulting from performance of four extracts chosen among the orchestral repertoire. Results, which were measured in both horizontal and vertical planes, show interesting differences between the average directivity of each test. They lead to links with few important distinctions in the traditional violin's positions inside the orchestra.

  2. Clinical measures of hearing aid directivity: assumption, accuracy, and reliability.

    PubMed

    Wu, Yu-Hsiang; Bentler, Ruth A

    2012-01-01

    A number of clinical measures of directivity, including the front-to-back ratio (FBR) and front-to-side ratio (FSR), have been suggested to audiologists to monitor the functionality of hearing aids with directional microphones. These suggestions, however, are based on the assumption that directivity measured clinically changes monotonically when compared with changes measured using the directivity index (DI) and perceptual directional benefit. The objective of the present study was to empirically examine this assumption. In addition, the reliability of the clinical directivity measure was estimated to establish a referral threshold for defective directional microphone hearing aids. The directivity of the directional microphones of two behind-the-ear hearing aids was systematically degraded by plugging the microphone ports. The directivity was measured using four clinical measures: the FBR and FSR performed in the test chamber of a hearing aid analyzer and in sound field. Each measure was repeated four times in each directivity-degraded condition. The degraded directivity was also assessed using the DI measure in an anechoic chamber. The perceptual directional benefit in each directivity-degraded condition was obtained by testing 10 hearing-impaired adults in a sound field with diffuse noise using the Hearing in Noise Test (HINT). The results of the DI and HINT measures showed strong correlation between the two FSRs (test chamber and sound field), while the two FBRs showed no correlation. The directivity generated by the FBRs could remain unchanged even when the directional microphone had lost more than 50% of its directivity. The results further indicated that the measures performed in the sound field were more reliable than those performed in the test chamber. Based on the results of the reliability measures, a 30% change in directivity was suggested as the referral threshold signifying defective directional systems. Because the FSR predicts the DI and HINT

  3. Wave directional spreading from point field measurements.

    PubMed

    McAllister, M L; Venugopal, V; Borthwick, A G L

    2017-04-01

    Ocean waves have multidirectional components. Most wave measurements are taken at a single point, and so fail to capture information about the relative directions of the wave components directly. Conventional means of directional estimation require a minimum of three concurrent time series of measurements at different spatial locations in order to derive information on local directional wave spreading. Here, the relationship between wave nonlinearity and directionality is utilized to estimate local spreading without the need for multiple concurrent measurements, following Adcock & Taylor (Adcock & Taylor 2009 Proc. R. Soc. A465, 3361-3381. (doi:10.1098/rspa.2009.0031)), with the assumption that directional spreading is frequency independent. The method is applied to measurements recorded at the North Alwyn platform in the northern North Sea, and the results compared against estimates of wave spreading by conventional measurement methods and hindcast data. Records containing freak waves were excluded. It is found that the method provides accurate estimates of wave spreading over a range of conditions experienced at North Alwyn, despite the noisy chaotic signals that characterize such ocean wave data. The results provide further confirmation that Adcock and Taylor's method is applicable to metocean data and has considerable future promise as a technique to recover estimates of wave spreading from single point wave measurement devices.

  4. Wave directional spreading from point field measurements

    PubMed Central

    Venugopal, V.; Borthwick, A. G. L.

    2017-01-01

    Ocean waves have multidirectional components. Most wave measurements are taken at a single point, and so fail to capture information about the relative directions of the wave components directly. Conventional means of directional estimation require a minimum of three concurrent time series of measurements at different spatial locations in order to derive information on local directional wave spreading. Here, the relationship between wave nonlinearity and directionality is utilized to estimate local spreading without the need for multiple concurrent measurements, following Adcock & Taylor (Adcock & Taylor 2009 Proc. R. Soc. A 465, 3361–3381. (doi:10.1098/rspa.2009.0031)), with the assumption that directional spreading is frequency independent. The method is applied to measurements recorded at the North Alwyn platform in the northern North Sea, and the results compared against estimates of wave spreading by conventional measurement methods and hindcast data. Records containing freak waves were excluded. It is found that the method provides accurate estimates of wave spreading over a range of conditions experienced at North Alwyn, despite the noisy chaotic signals that characterize such ocean wave data. The results provide further confirmation that Adcock and Taylor's method is applicable to metocean data and has considerable future promise as a technique to recover estimates of wave spreading from single point wave measurement devices. PMID:28484326

  5. Wave directional spreading from point field measurements

    NASA Astrophysics Data System (ADS)

    McAllister, M. L.; Venugopal, V.; Borthwick, A. G. L.

    2017-04-01

    Ocean waves have multidirectional components. Most wave measurements are taken at a single point, and so fail to capture information about the relative directions of the wave components directly. Conventional means of directional estimation require a minimum of three concurrent time series of measurements at different spatial locations in order to derive information on local directional wave spreading. Here, the relationship between wave nonlinearity and directionality is utilized to estimate local spreading without the need for multiple concurrent measurements, following Adcock & Taylor (Adcock & Taylor 2009 Proc. R. Soc. A 465, 3361-3381. (doi:10.1098/rspa.2009.0031)), with the assumption that directional spreading is frequency independent. The method is applied to measurements recorded at the North Alwyn platform in the northern North Sea, and the results compared against estimates of wave spreading by conventional measurement methods and hindcast data. Records containing freak waves were excluded. It is found that the method provides accurate estimates of wave spreading over a range of conditions experienced at North Alwyn, despite the noisy chaotic signals that characterize such ocean wave data. The results provide further confirmation that Adcock and Taylor's method is applicable to metocean data and has considerable future promise as a technique to recover estimates of wave spreading from single point wave measurement devices.

  6. Proximal contact tightness between direct-composite additions in the posterior dentition: an in vitro investigation.

    PubMed

    Wolff, Diana; Hahn, Philipp; Ding, Paul; Maier-Kraus, Theresa; Frese, Cornelia; Doerfer, Christof; Staehle, Hans Joerg

    2012-01-01

    The aim of the study was to test whether a novel three-step matrix technique for posterior direct-composite additions creates sufficiently strong proximal contacts. Contact tightness was measured between direct-composite additions and between original teeth on a model. Therefore, the frictional forces required to remove a straight, 0.05-mm-thick, metal matrix band inserted between adjacent teeth and held by a universal testing machine (Zwicki, Zwick GmbH, Ulm, Germany) were recorded. Measurements were taken at three time points to carry out reference analysis: at baseline, after removal of the maxillary right second premolar (tooth #15) to simulate a diastema, and after closure of the diastema by inserting two direct-composite additions with the three-step matrix technique on the maxillary right first premolar (tooth #14) and first molar (tooth #16). Measurements were performed in the maxillary right (first) and left (second) quadrants to document sagittal displacement. The original contact tightness values were between 1.65 ± 0.88 N and 3.05 ± 0.60 N in the first quadrant and between 1.23 ± 0.51 N and 2.18 ± 0.43 N in the second quadrant. After removal of tooth 15, values decreased significantly in the first quadrant and insignificantly in the second. After reconstruction, the contact tightness between teeth 14 and 16 was significantly stronger (tighter) (3.20 ± 0.80 N) than the originally measured contact tightness between teeth 14 and 15 (2.86 ± 0.64 N) and teeth 15 and 16 (1.65 ± 0.88 N) (p=0.006 and 0.001, respectively). Within the limitations of an in vitro investigation, this study has shown that by using a novel, three-step matrix technique, direct posterior composite additions can form sufficiently tight proximal contacts.

  7. Data on directionality measures of adaptive systems

    NASA Astrophysics Data System (ADS)

    Nilsson, Michael J.; Wellington, Jim; Kirsch, Jay; Bray, Victor

    2005-09-01

    Directionality has become the dominant method to improve the signal-to-noise ratio in hearing aids. Quantification of differences in the amount of directionality between systems has become a source of scientific, as well as marketing, interest. Developments in directionality now involve signal processing methods that interact with directional microphones based upon adaptive algorithms in order to broaden the appeal and usefulness of these systems. The ANSI S3.35 revision for 2004 improves the methodology for relating measures of directionality to expected performance when using many systems, but fails to address measurements using these adaptive systems. These systems respond differently depending upon the type, volume, or location of a stimulus, and will generate different results using the single noise source technique included in the standard compared to diffuse noise conditions. This presentation presents data using various measurement techniques to quantify the differences between directional systems. Different types of adaptive systems will be identified that vary in their interaction with the ANSI methods and an understanding of how measurements change with changes in technique will be presented.

  8. Velocity Gradient Maps Directly Measured by PLF

    NASA Astrophysics Data System (ADS)

    Quintella, Cristina M.; Gonçalves, Cristiane C.; Lima, Angelo Mv; Pepe, Iuri M.

    2000-11-01

    Flows are macroscopically classified as laminar or turbulent due to their velocity distributions, nevertheless most chemical and biological phenomena are yield or enhanced by intermolecular orientation and microscopic turbulence. Here was studied a 100micra liquid sheet produced by a slit nozzle, both flowing freely into air and over a borosilicate surface (roughness bellow 5nm), ranging from 17 to 36Re (143 to 297cm/s, similar to muscles and brain blood flow). Mono ethylene glycol was used either pure, or with sodium alkyl benzene sulfated (ABS) surfactant (24.5mol/L, submicellar), or with poly(ethylene oxide) (PEO) (1409ppm, 4millions aw). Velocity gradients were directly measured by 514nm polarized laser induced fluorescence (PLF) with R6G as probe. Intermolecular alignment (IA) maps were obtained all over the flow (about 1,950 points, 0.02mm2 precision). The free jet average IA has increased 57% when flowing over borosilicate. With ABS, the IA increased, suggesting wall drag reduction. With PEO the IA decreases due to solvent intermolecular forces attenuation, generating wider turbulent areas. PLF proved to be an excellent method to evaluate IA within liquid thin flows. Chosen solute additions permits IA control over wide regions.

  9. On Directional Measurement Representation in Orbit Determination

    DTIC Science & Technology

    2016-09-13

    equirectangular projection distorts both distance and direction on a map . One technique is to weight the azimuth residuals by the cosine of the elevation, as in...directional measurements is equivalent to choosing a transformation from location on a sphere to location in a plane which has a long history in map ...The second approach is to preserve area in mapping the celestial sphere to the plane by weighting the azimuth residual by the length of the

  10. Direct Determination of Cadmium in Seawater by Standard Addition ICP-QMS/QMS with an ORC.

    PubMed

    Zhu, Yanbei; Itoh, Akihide

    2016-01-01

    A method for direct and precise determination of Cd in seawater by ICP-QMS/QMS was developed, where a high matrix introducing unit permitted the direct introduction of seawater without clogging the cones while the matrix effect of seawater was canceled by standard addition. NH3 gas was selected as the reaction gas for removing the MoO interferences with the measurement of Cd isotopes, effectively improving the signal to background ratio. The lower limit of detection obtained at (114)Cd was 0.0002 ng mL(-1), which is enough for the determination of Cd in natural seawater. The validity of the present method was confirmed by the analysis of two certified reference materials, i.e. NASS-5 and NASS-6, whose observed values of Cd concentration agreed with the certified values. The analytical figures of merit of the present method were comparable to or better than those reported for direct analysis of seawater.

  11. Research on optical measurement for additive manufacturing surfaces

    NASA Astrophysics Data System (ADS)

    Cheng, Fang; Fu, Shao Wei; Leong, Yong Shin

    2017-02-01

    Surfaces made by Additive Manufacturing (AM) processes normally show higher roughness and more complicated microstructures than conventional machined surfaces. In this study, AM surface roughness measurements using both tactile and optical techniques are analyzed, theoretically and experimentally. Analytical results showed both techniques have comparable performance when measuring AM samples with good surface integrity. For surfaces with steep features, coherence scanning interferometry showed more reliable performance especially when peak-to-valley value was required. In addition of the benchmarking study, development of a low-cost measurement system, using laser confocal technology, is also presented in this paper. By comparing the measurement results with those from a coherent scanning interferometer, accuracy levels of the proposed system can be evaluated. It was concluded that with comparable accuracy, the proposed low-cost optical system was able to achieve much faster measurements, which would make it possible for in-situ surface quality checking.

  12. Direct-reading group-delay measurement

    NASA Technical Reports Server (NTRS)

    Trowbridge, D. L.

    1978-01-01

    Technique for measuring modulation signal retardation in microwave components gives direct plot of dependence of delay time on carrier frequency. Recorder sensitivity can be adjusted to give convenient scale factor for group delay. From family of such recordings, it is possible to observe changes in group delay due to temperature, mechanical stress, and other factors.

  13. Direct strike lightning measurement system. [for aircraft

    NASA Technical Reports Server (NTRS)

    Thomas, M. E.

    1981-01-01

    A research data system developed for in-flight measurement of direct and nearby lightning-strike characteristics is described. The measurement system consists of a wide-band analog recorder which records the continuous lightning scenario and fast sample-rate digital transient recorders with augmented memory capacity for increased time resolution of specific times of interest. Electromagnetic sensors with bandwidths exceeding 100 MHz are used which respond to rates of change of the quantities being measured. Data system immunity from electromagnetic interference is accomplished by the use of a dynamotor for power isolation, shielded system enclosure and fiber-optic data links.

  14. Wind measurement via direct detection lidar

    NASA Astrophysics Data System (ADS)

    Afek, I.; Sela, N.; Narkiss, N.; Shamai, G.; Tsadka, S.

    2013-10-01

    Wind sensing Lidar is considered a promising technology for high quality wind measurements required for various applications such as hub height wind resource assessment, power curve measurements and advanced, real time, forward looking turbine control. Until recently, the only available Lidar technology was based on coherent Doppler shift detection, whose market acceptance has been slow primarily due to its exuberant price. Direct detection Lidar technology provides an alternative to remote sensing of wind by incorporating high precision measurement, a robust design and an affordable price tag.

  15. Directivity quantification in hearing aids: fitting and measurement effects.

    PubMed

    Ricketts, T

    2000-02-01

    To evaluate the impact of venting, microphone port orientation, and compression on the electroacoustically measured directivity of directional and omnidirectional behind-the-ear hearing aids. In addition, the average directivity provided across three brands of directional and omnidirectional behind-the-ear hearing aids was compared with that provided by the open ear. Three groups of hearing aids (four instruments in each group) representing three commercial models (a total of 12) were selected for electroacoustic evaluation of directivity. Polar directivity patterns were measured and directivity index was calculated across four different venting configurations, and for five different microphone port angles. All measurements were made for instruments in directional and omnidirectional modes. Single source traditional, and two-source modified front-to-back ratios were also measured with the hearing aids in linear and compression modes. The directivity provided by the open (Knowles Electronics Manikin for Acoustic Research) ear was superior to that of the omnidirectional hearing aids in this study. Although the directivity measured for directional hearing aids was significantly better than that of omnidirectional models, significant variability was measured both within and across the tested models both on average and at specific test frequencies. Both venting and microphone port orientation affected the measured directivity. Although compression reduced the magnitude of traditionally measured front-to-back ratios, no difference from linear amplification was noted using a modified methodology. The variation in the measured directivity both within and across the directional microphone hearing aid brands suggests that manufacturer's specification of directivity may not provide an accurate index of the actual performance of all individual instruments. The significant impact of venting and microphone port orientation on directivity indicate that these variables must be

  16. Direct measurement of the W boson width

    SciTech Connect

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Aguilo, E.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; Alton, A.; /Michigan U. /Northeastern U.

    2009-09-01

    We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W {yields} e{nu} candidates selected in 1 fb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron collider in p{bar p} collisions at {radical}s = 1.96 TeV. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 {+-} 0.072 GeV, is in agreement with the predictions of the standard model and is the most precise direct measurement result from a single experiment to date.

  17. Direct measurements of membrane unstirred layers

    PubMed Central

    Green, K.; Otori, T.

    1970-01-01

    1. The unstirred layer of fluid bounding the posterior surface of the rabbit cornea and contact lens has been directly measured using an optical apparatus. 2. Small polystyrene latex spheres (< 0·25 μ diameter) were used as an indicator because of the excellent light-reflective properties; other indicators were used (e.g. carmine particles) and had a similar behaviour. 3. With the bulk solution unstirred the layer was 350 μ thick on the cornea and 150 μ thick on the contact lens. Following vigorous stirring the layer was reduced to 65 μ on the cornea and < 20 μ on the contact lens. 4. The present direct measurements of the unstirred layers thickness confirm previous indirect measurements. ImagesFig. 2Fig. 3Fig. 4Fig. 5 PMID:5503890

  18. How Phoenix Measures Wind Speed and Direction

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation

    This animation shows how NASA's Phoenix Mars Lander can measure wind speed and direction by imaging the Telltale with the Stereo Surface Imager (SSI).

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  19. How to detect the Granger-causal flow direction in the presence of additive noise?

    PubMed

    Vinck, Martin; Huurdeman, Lisanne; Bosman, Conrado A; Fries, Pascal; Battaglia, Francesco P; Pennartz, Cyriel M A; Tiesinga, Paul H

    2015-03-01

    Granger-causality metrics have become increasingly popular tools to identify directed interactions between brain areas. However, it is known that additive noise can strongly affect Granger-causality metrics, which can lead to spurious conclusions about neuronal interactions. To solve this problem, previous studies have proposed the detection of Granger-causal directionality, i.e. the dominant Granger-causal flow, using either the slope of the coherency (Phase Slope Index; PSI), or by comparing Granger-causality values between original and time-reversed signals (reversed Granger testing). We show that for ensembles of vector autoregressive (VAR) models encompassing bidirectionally coupled sources, these alternative methods do not correctly measure Granger-causal directionality for a substantial fraction of VAR models, even in the absence of noise. We then demonstrate that uncorrelated noise has fundamentally different effects on directed connectivity metrics than linearly mixed noise, where the latter may result as a consequence of electric volume conduction. Uncorrelated noise only weakly affects the detection of Granger-causal directionality, whereas linearly mixed noise causes a large fraction of false positives for standard Granger-causality metrics and PSI, but not for reversed Granger testing. We further show that we can reliably identify cases where linearly mixed noise causes a large fraction of false positives by examining the magnitude of the instantaneous influence coefficient in a structural VAR model. By rejecting cases with strong instantaneous influence, we obtain an improved detection of Granger-causal flow between neuronal sources in the presence of additive noise. These techniques are applicable to real data, which we demonstrate using actual area V1 and area V4 LFP data, recorded from the awake monkey performing a visual attention task.

  20. Is direct measurement of time possible?

    NASA Astrophysics Data System (ADS)

    Reynolds, Thomas

    2017-08-01

    Is direct measurement of time possible? The answer to this question may depend upon how one understands time. Is time an essential constituent of physical reality? Or is what scientists are talking about when they use the symbol ‘t’ or the word ‘time’ an human cultural construct, as the Chief of the USA NIST Divisions of Time and Frequency and of Quantum Physics has suggested. Few aspects of physics do not reference activity to time, but many discussions within either view of time seem to use one same, largely traditional, language of time. Briefly considering the question of measurement, including from a formal measure-theoretic point of view, clarifies the situation.

  1. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  2. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  3. Measurement of directional thermal properties of biomaterials.

    PubMed

    Bhavaraju, N C; Cao, H; Yuan, D Y; Valvano, J W; Webster, J G

    2001-02-01

    This paper presents an experimental technique to measure the directional thermal conductivity and thermal diffusivity of materials. A heated thermistor heats the sample and a sensing thermistor placed about 2.5 mm away measures the temperature rise due the heating pulse at the heated thermistor. An empirical relation between the power delivered by the first thermistor and the temperature rise recorded by the sensing thermistor is used to measure the thermal conductivity of the material along the line joining the thermistors. Diffusivity of the material is determined from the delay between the power pulse in the heated thermistor and the temperature pulse at the sensing thermistor. Signal processing was done to eliminate errors in the measurement due to change of base line temperature. Uncertainty of the measurement technique was found to be 5% when tested in media of known thermal properties. The thermal conductivity and thermal diffusivity of swine left ventricle in normal and ablated conditions were measured using this technique. The thermal conductivity of the tissue dropped significantly from 0.61 to 0.50 W.m(-1).K(-1) after ablation while the diffusivity dropped from 2.1 x 10(-7) to 1.7 x 10(-7)m2.s(-1).

  4. 30 CFR 250.1925 - May BSEE direct me to conduct additional audits?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Environmental Management Systems (SEMS) § 250.1925 May BSEE direct me to conduct additional audits? (a) If BSEE... 30 Mineral Resources 2 2012-07-01 2012-07-01 false May BSEE direct me to conduct additional audits? 250.1925 Section 250.1925 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT...

  5. Directional wave measurements using an autonomous vessel

    NASA Astrophysics Data System (ADS)

    Hole, Lars R.; Fer, Ilker; Peddie, David

    2016-09-01

    An autonomous vessel, the Offshore Sensing Sailbuoy, was used for wave measurements near the Ekofisk oil platform complex in the North Sea (56.5º N, 3.2º E, operated by ConocoPhillips) from 6 to 20 November 2015. Being 100 % wind propelled, the Sailbuoy has two-way communication via the Iridium network and has the capability for missions of 6 months or more. It has previously been deployed in the Arctic, Norwegian Sea and the Gulf of Mexico, but the present study was the first test for wave measurements. During the campaign the Sailbuoy held position about 20 km northeast of Ekofisk (on the lee side) during rough conditions. Mean wind speed measured at Ekofisk during the campaign was 9.8 m/s, with a maximum of 20.4 m/s, with wind mostly from south and southwest. A Datawell MOSE G1000 GPS-based 2 Hz wave sensor was mounted on the Sailbuoy. Mean significant wave height ( H s 1 min) measured was 3 m, whereas maximum H s was 6 m. Mean wave period was 7.7 s, while maximum wave height, H max, was 12.6 m. These measurements have been compared with non-directional Waverider observations at the Ekofisk complex. The agreement between the two data sets was very good, with a mean percent absolute error of 7 % and a linear correlation coefficient of 0.97. The wave frequency spectra measured by the two instruments compared very well, except for low H s (˜1 m), where the motion of the vessel seemed to influence the measurements. Nevertheless, the Sailbuoy performed well during this campaign, and results suggest that it is a suitable platform for wave measurements in a broad range of sea conditions.

  6. Direction finding measurements of auroral kilometric radiation

    NASA Technical Reports Server (NTRS)

    Kurth, W. S.; Baumback, M. M.; Gurnett, D. A.

    1974-01-01

    Direction finding measurements with plasma wave experiments onboard the Hawkeye-1 and IMP-8 satellites were used to locate the source region of auroral kilometric radiation. The radiation exhibits peak intensities between about 100 kHz and 300 kHz, and emits intense sporadic bursts lasting for between one half hour to several hours. The total power emitted in this frequency range exceeds 10 to the 9th power watts at peak intensity. The occurrence of the radiation is known to be closely associated with bright auroral arcs which occur in the local evening auroral regions.

  7. Direct measurement of the Chudakov effect.

    PubMed

    Virkus, T; Thomsen, H D; Uggerhøj, E; Uggerhøj, U I; Ballestrero, S; Sona, P; Mangiarotti, A; Ketel, T J; Dizdar, A; Kartal, S; Pagliarone, C

    2008-04-25

    Experimental results for the restricted energy loss of pairs created from 1-178 GeV photons in a thin Au target and subsequently passing a CCD detector are presented. It is shown that pairs--when detected close to the creation vertex--suffer a reduced energy loss due to the internal screening of the charges constituting the pair. Furthermore, the ability to measure directly the energy of the pair by calorimetry enables a comparison with theory as a function of energy. The observed phenomenon is in good qualitative agreement with general expectations from the Chudakov effect but indicates a quantitative disagreement with either of two mutually disagreeing theories.

  8. Additional studies for the spectrophotometric measurement of iodine in water

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Previous work in iodine spectroscopy is briefly reviewed. Continued studies of the direct spectrophotometric determination of aqueous iodine complexed with potassium iodide show that free iodine is optimally determined at the isosbestic point for these solutions. The effects on iodine determinations of turbidity and chemical substances (in trace amounts) is discussed and illustrated. At the levels tested, iodine measurements are not significantly altered by such substances. A preliminary design for an on-line, automated iodine monitor with eventual capability of operating also as a controller was analyzed and developed in detail with respect single beam colorimeter operating at two wavelengths (using a rotating filter wheel). A flow-through sample cell allows the instrument to operate continuously, except for momentary stop flow when measurements are made. The timed automatic cycling of the system may be interrupted whenever desired, for manual operation. An analog output signal permits controlling an iodine generator.

  9. Direct measurement of the W boson width.

    PubMed

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Ancu, L S; Andeen, T; Anzelc, M S; Aoki, M; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Atramentov, O; Avila, C; BackusMayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Bu, X B; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Calfayan, P; Calpas, B; Calvet, S; Cammin, J; Carrasco-Lizarraga, M A; Carrera, E; Carvalho, W; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Cheu, E; Cho, D K; Cho, S W; Choi, S; Choudhary, B; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Cutts, D; Cwiok, M; Das, A; Davies, G; De, K; de Jong, S J; De La Cruz-Burelo, E; DeVaughan, K; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duflot, L; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Escalier, M; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Gadfort, T; Galea, C F; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Golovanov, G; Gómez, B; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinson, A P; Heintz, U; Hensel, C; Heredia-De La Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jamin, D; Jesik, R; Johns, K; Johnson, C; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Juste, A; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Khatidze, D; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J-P; Kozelov, A V; Kraus, J; Kuhl, T; Kumar, A; Kupco, A; Kurca, T; Kuzmin, V A; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, H S; Lee, W M; Leflat, A; Lellouch, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Mackin, D; Mättig, P; Magaña-Villalba, R; Mal, P K; Malik, S; Malyshev, V L; Maravin, Y; Martin, B; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Mendoza, L; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Mondal, N K; Montgomery, H E; Moore, R W; Moulik, T; Muanza, G S; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Novaes, S F; Nunnemann, T; Obrant, G; Ochando, C; Onoprienko, D; Orduna, J; Oshima, N; Osman, N; Osta, J; Otec, R; Otero y Garzón, G J; Owen, M; Padilla, M; Padley, P; Pangilinan, M; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Polozov, P; Popov, A V; Prewitt, M; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K; Ratoff, P N; Renkel, P; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Siccardi, V; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Stolin, V; Stoyanova, D A; Strandberg, J; Strang, M A; Strauss, E; Strauss, M; Ströhmer, R; Strom, D; Stutte, L; Sumowidagdo, S; Svoisky, P; Takahashi, M; Tanasijczuk, A; Taylor, W; Tiller, B; Titov, M; Tokmenin, V V; Torchiani, I; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; van den Berg, P J; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vint, P; Vokac, P; Wagner, R; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, G; Weber, M; Wenger, A; Wetstein, M; White, A; Wicke, D; Williams, M R J; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Xu, C; Yacoob, S; Yamada, R; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Ye, Z; Yin, H; Yip, K; Yoo, H D; Youn, S W; Yu, J; Zeitnitz, C; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L; Zutshi, V; Zverev, E G

    2009-12-04

    We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W --> enu candidate events. Data from approximately 1 fb(-1) of integrated luminosity recorded at square root of s = 1.96 TeV by the D0 detector at the Fermilab Tevatron pp collider are analyzed. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 +/- 0.072 GeV, is in agreement with the predictions of the standard model.

  10. Porosity Measurements and Analysis for Metal Additive Manufacturing Process Control

    PubMed Central

    Slotwinski, John A; Garboczi, Edward J; Hebenstreit, Keith M

    2014-01-01

    Additive manufacturing techniques can produce complex, high-value metal parts, with potential applications as critical metal components such as those found in aerospace engines and as customized biomedical implants. Material porosity in these parts is undesirable for aerospace parts - since porosity could lead to premature failure - and desirable for some biomedical implants - since surface-breaking pores allows for better integration with biological tissue. Changes in a part’s porosity during an additive manufacturing build may also be an indication of an undesired change in the build process. Here, we present efforts to develop an ultrasonic sensor for monitoring changes in the porosity in metal parts during fabrication on a metal powder bed fusion system. The development of well-characterized reference samples, measurements of the porosity of these samples with multiple techniques, and correlation of ultrasonic measurements with the degree of porosity are presented. A proposed sensor design, measurement strategy, and future experimental plans on a metal powder bed fusion system are also presented. PMID:26601041

  11. Porosity Measurements and Analysis for Metal Additive Manufacturing Process Control.

    PubMed

    Slotwinski, John A; Garboczi, Edward J; Hebenstreit, Keith M

    2014-01-01

    Additive manufacturing techniques can produce complex, high-value metal parts, with potential applications as critical metal components such as those found in aerospace engines and as customized biomedical implants. Material porosity in these parts is undesirable for aerospace parts - since porosity could lead to premature failure - and desirable for some biomedical implants - since surface-breaking pores allows for better integration with biological tissue. Changes in a part's porosity during an additive manufacturing build may also be an indication of an undesired change in the build process. Here, we present efforts to develop an ultrasonic sensor for monitoring changes in the porosity in metal parts during fabrication on a metal powder bed fusion system. The development of well-characterized reference samples, measurements of the porosity of these samples with multiple techniques, and correlation of ultrasonic measurements with the degree of porosity are presented. A proposed sensor design, measurement strategy, and future experimental plans on a metal powder bed fusion system are also presented.

  12. Modeling Errors in Daily Precipitation Measurements: Additive or Multiplicative?

    NASA Technical Reports Server (NTRS)

    Tian, Yudong; Huffman, George J.; Adler, Robert F.; Tang, Ling; Sapiano, Matthew; Maggioni, Viviana; Wu, Huan

    2013-01-01

    The definition and quantification of uncertainty depend on the error model used. For uncertainties in precipitation measurements, two types of error models have been widely adopted: the additive error model and the multiplicative error model. This leads to incompatible specifications of uncertainties and impedes intercomparison and application.In this letter, we assess the suitability of both models for satellite-based daily precipitation measurements in an effort to clarify the uncertainty representation. Three criteria were employed to evaluate the applicability of either model: (1) better separation of the systematic and random errors; (2) applicability to the large range of variability in daily precipitation; and (3) better predictive skills. It is found that the multiplicative error model is a much better choice under all three criteria. It extracted the systematic errors more cleanly, was more consistent with the large variability of precipitation measurements, and produced superior predictions of the error characteristics. The additive error model had several weaknesses, such as non constant variance resulting from systematic errors leaking into random errors, and the lack of prediction capability. Therefore, the multiplicative error model is a better choice.

  13. Verification of the directivity index and other measures of directivity in predicting directional benefit

    NASA Astrophysics Data System (ADS)

    Dittberner, Andrew; Bentler, Ruth

    2005-09-01

    The relationship between various directivity measures and subject performance with directional microphone hearing aids was determined. Test devices included first- and second-order directional microphones. Recordings of sentences and noise (Hearing in Noise Test, HINT) were made through each test device in simple, complex, and anisotropic background noise conditions. Twenty-six subjects, with normal hearing, were administered the HINT test recordings, and directional benefit was computed. These measures were correlated to theoretical, free-field, and KEMAR DI values, as well as front-to-back ratios, in situ SNRs, and a newly proposed Db-SNR, wherein a predictive value of the SNR improvement is calculated as a function of the noise source incidence. The different predictive scores showed high correlation to the measured directional benefit scores in the complex (diffuse-like) background noise condition (r=0.89-0.97, p<0.05) but not across all background noise conditions (r=0.45-0.97, p<0.05). The Db-SNR approach and the in situ SNR measures provided excellent prediction of subject performance in all background noise conditions (0.85-0.97, p<0.05) None of the predictive measures could account for the effects of reverberation on the speech signal (r=0.35-0.40, p<0.05).

  14. Direct measurement of solar luminosity variation.

    PubMed

    Willson, R C; Duncan, C H; Geist, J

    1980-01-11

    Two rocket flights of an absolute pyrheliometer, separated by 30 months, indicate an increase in solar luminosity (solar constant) of 0.4 percent. The significance of this result is considered in light of the instrument performance during the rocket flights and of pre- and postflight intercomparisons with independently maintained pyrheliometers. There is a high probability that the measured difference is real. Additional observations are required to determine whether the difference results from random fluctuations in solar luminosity, a nonrandom change of short duration, or a sustained change that has climatological significance.

  15. Direct measurement of intrinsic atomic scale magnetostriction.

    PubMed

    Ruffoni, M P; Pascarelli, S; Grössinger, R; Turtelli, R Sato; Bormio-Nunes, C; Pettifer, R F

    2008-10-03

    Using differential x-ray absorption spectroscopy (DiffXAS) we have measured and quantified the intrinsic, atomic-scale magnetostriction of Fe81Ga19. By exploiting the chemical selectivity of DiffXAS, the Fe and Ga local environments have been assessed individually. The enhanced magnetostriction induced by the addition of Ga to Fe was found to originate from the Ga environment, where lambda;{gamma,2}( approximately (3/2)lambda_{100}) is 390+/-40 ppm. In this environment, 001 Ga-Ga pair defects were found to exist, which mediate the magnetostriction by inducing large strains in the surrounding Ga-Fe bonds. For the first time, intrinsic, chemically selective magnetostrictive strain has been measured and quantified at the atomic level, allowing true comparison with theory.

  16. Direct measurement of antiferromagnetic domain fluctuations.

    PubMed

    Shpyrko, O G; Isaacs, E D; Logan, J M; Feng, Yejun; Aeppli, G; Jaramillo, R; Kim, H C; Rosenbaum, T F; Zschack, P; Sprung, M; Narayanan, S; Sandy, A R

    2007-05-03

    Measurements of magnetic noise emanating from ferromagnets owing to domain motion were first carried out nearly 100 years ago, and have underpinned much science and technology. Antiferromagnets, which carry no net external magnetic dipole moment, yet have a periodic arrangement of the electron spins extending over macroscopic distances, should also display magnetic noise. However, this must be sampled at spatial wavelengths of the order of several interatomic spacings, rather than the macroscopic scales characteristic of ferromagnets. Here we present a direct measurement of the fluctuations in the nanometre-scale superstructure of spin- and charge-density waves associated with antiferromagnetism in elemental chromium. The technique used is X-ray photon correlation spectroscopy, where coherent X-ray diffraction produces a speckle pattern that serves as a 'fingerprint' of a particular magnetic domain configuration. The temporal evolution of the patterns corresponds to domain walls advancing and retreating over micrometre distances. This work demonstrates a useful measurement tool for antiferromagnetic domain wall engineering, but also reveals a fundamental finding about spin dynamics in the simplest antiferromagnet: although the domain wall motion is thermally activated at temperatures above 100 K, it is not so at lower temperatures, and indeed has a rate that saturates at a finite value-consistent with quantum fluctuations-on cooling below 40 K.

  17. Direct in situ measurements of thermospheric temperature

    NASA Technical Reports Server (NTRS)

    Kayser, D. C.; Nier, A. O.; Breig, E. L.; Power, R. A.; Hanson, W. B.

    1979-01-01

    The open source neutral mass spectrometer on the Atmosphere Explorer satellites used for direct in situ measurements of the neutral gas temperature by means of the 'fly-through' mode of operation is evaluated. The derived neutral temperature (Tn) is compared with ion temperatures (T1) obtained simultaneously from the on-board retarding potential analyzer for altitudes and conditions where the two temperatures should be equal. A statistical analysis showed consistency between concurrently observed values of Tn and T1, also shown through profiles depicting their altitude distributions between 150 and 225 km. The overall magnitude of temperatures calculated from the Jacchia (1971) model results in a better representation of the observations than the higher temperatures predicted for this region by the MSIS model (Hedin, 1977), and agreement is also found between observed temperatures and neutral temperatures derived from altitude distributions of N2 particle densities.

  18. Wind speed and direction measurements using the sphere anemometer

    NASA Astrophysics Data System (ADS)

    Heisselmann, Hendrik; Hoelling, Michael; Peinke, Joachim

    2009-11-01

    In times of growing energy demand, the importance of wind energy is rapidly increasing and so is the need for accurate wind speed and direction measurements. The widely spread cup anemometers show significant over-speeding under turbulent wind conditions as inherent in atmospherical flows while being solely capable of detecting the wind speed. Therefore, we propose the newly developed sphere anemometer as a simple an robust sensor for direction and velocity measurements. The sphere anemometer exploits the velocity-dependent deflection of a tube, which is the order of μm and can be detected by means of a light pointer as used in atomic force microscopes. In comparative measurements under laboratory conditions the sphere anemometer showed a significantly higher temporal resolution then cup anemometers while it does not exhibit any over-speeding. Additionally, results of atmospherical wind measurements with the sphere anemometer and state-of-the-art cup anemometry are presented.

  19. SOLUBILIZATION AND MICROEMULSIFICATION OF CHLORINATED SOLVENTS USING DIRECT FOOD ADDITIVE (EDIBLE) SURFACTANTS (JOURNAL)

    EPA Science Inventory

    Surfactant enhanced subsurface remediation is being evaluated as an innovative technology to expedite contaminant extraction from the subsurface. Regulatory approval of this technology will likely be enhanced by use of surfactants with FDA direct food additive status ("edible" su...

  20. SOLUBILIZATION AND MICROEMULSIFICATION OF CHLORINATED SOLVENTS USING DIRECT FOOD ADDITIVE (EDIBLE) SURFACTANTS (JOURNAL)

    EPA Science Inventory

    Surfactant enhanced subsurface remediation is being evaluated as an innovative technology to expedite contaminant extraction from the subsurface. Regulatory approval of this technology will likely be enhanced by use of surfactants with FDA direct food additive status ("edible" su...

  1. Measurement and visualization of three-dimensional directivity pattern

    NASA Astrophysics Data System (ADS)

    Arndt, Georg-Erwin; Gebert, Anton; Klemenz, Harald; Ritter, Hartmut C.

    2005-09-01

    In order to optimize a new second-order multimicrophone technology for a KEMAR dummy head, a three-dimensional directivity measurement setup was developed. To minimize mechanical mass and to reduce total measurement time a C-Bow setup was used, containing 18 calibrated loudspeakers. Those small tweeters identical in construction are placed in every 10 deg of elevation in a semicircular arc of 2-m diameter. The only moving part of this setup is a full-circle rotating KEMAR. The ANSI Standard 3.35 for directional measurement is fully supported and the required 48 measuring points are completed in less than 3 min. Using this fast and simple setup, the various responses attained from different latitudes need to be weighted to calculate a three-dimensional directivity value. Utilizing an equally distributed number, for example 400 measuring points easily executable with this setup, weighting can be omitted and a three-dimensional plot with high resolution can be visualized. Additionally, two-dimensional cuts of different planes in horizontal, vertical, and sagittal direction can be displayed. Data of unaided KEMAR, as well as data from the hearing aid used during those measurements, are presented and discussed.

  2. Direct measurement of critical Casimir forces

    NASA Astrophysics Data System (ADS)

    Hertlein, C.; Helden, L.; Gambassi, A.; Dietrich, S.; Bechinger, C.

    2008-01-01

    When fluctuating fields are confined between two surfaces, long-range forces arise. A famous example is the quantum-electrodynamical Casimir force that results from zero-point vacuum fluctuations confined between two conducting metal plates. A thermodynamic analogue is the critical Casimir force: it acts between surfaces immersed in a binary liquid mixture close to its critical point and arises from the confinement of concentration fluctuations within the thin film of fluid separating the surfaces. So far, all experimental evidence for the existence of this effect has been indirect. Here we report the direct measurement of critical Casimir force between a single colloidal sphere and a flat silica surface immersed in a mixture of water and 2,6-lutidine near its critical point. We use total internal reflection microscopy to determine in situ the forces between the sphere and the surface, with femtonewton resolution. Depending on whether the adsorption preferences of the sphere and the surface for water and 2,6-lutidine are identical or opposite, we measure attractive and repulsive forces, respectively, that agree quantitatively with theoretical predictions and exhibit exquisite dependence on the temperature of the system. We expect that these features of critical Casimir forces may result in novel uses of colloids as model systems.

  3. Direct measurement of critical Casimir forces.

    PubMed

    Hertlein, C; Helden, L; Gambassi, A; Dietrich, S; Bechinger, C

    2008-01-10

    When fluctuating fields are confined between two surfaces, long-range forces arise. A famous example is the quantum-electrodynamical Casimir force that results from zero-point vacuum fluctuations confined between two conducting metal plates. A thermodynamic analogue is the critical Casimir force: it acts between surfaces immersed in a binary liquid mixture close to its critical point and arises from the confinement of concentration fluctuations within the thin film of fluid separating the surfaces. So far, all experimental evidence for the existence of this effect has been indirect. Here we report the direct measurement of critical Casimir force between a single colloidal sphere and a flat silica surface immersed in a mixture of water and 2,6-lutidine near its critical point. We use total internal reflection microscopy to determine in situ the forces between the sphere and the surface, with femtonewton resolution. Depending on whether the adsorption preferences of the sphere and the surface for water and 2,6-lutidine are identical or opposite, we measure attractive and repulsive forces, respectively, that agree quantitatively with theoretical predictions and exhibit exquisite dependence on the temperature of the system. We expect that these features of critical Casimir forces may result in novel uses of colloids as model systems.

  4. 30 CFR 250.1925 - May BOEMRE direct me to conduct additional audits?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SHELF Safety and Environmental Management Systems (SEMS) § 250.1925 May BOEMRE direct me to conduct... 30 Mineral Resources 2 2011-07-01 2011-07-01 false May BOEMRE direct me to conduct additional audits? 250.1925 Section 250.1925 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND...

  5. Direct Copper-Free Domino Conjugate Addition-Cycloallylation using Organozinc Reagents

    PubMed Central

    Komanduri, Venukrishnan; Pedraza, Fernando; Krische, Michael J.

    2010-01-01

    The Direct Approach: Enones possessing appendant allylic carbonates react directly with diorganozinc reagents in the presence of zinc diiodide [ZnI2] to provide 5- and 6-membered ring products of tandem or domino conjugate addition-cycloallylation in good to excellent yield. In a related copper-free transformation, allylic carbonates are found to engage in direct allylic substitution with diorganozinc reagents. PMID:20454546

  6. Global estimate of aerosol direct radiative forcing from satellite measurements.

    PubMed

    Bellouin, Nicolas; Boucher, Olivier; Haywood, Jim; Reddy, M Shekar

    2005-12-22

    Atmospheric aerosols cause scattering and absorption of incoming solar radiation. Additional anthropogenic aerosols released into the atmosphere thus exert a direct radiative forcing on the climate system. The degree of present-day aerosol forcing is estimated from global models that incorporate a representation of the aerosol cycles. Although the models are compared and validated against observations, these estimates remain uncertain. Previous satellite measurements of the direct effect of aerosols contained limited information about aerosol type, and were confined to oceans only. Here we use state-of-the-art satellite-based measurements of aerosols and surface wind speed to estimate the clear-sky direct radiative forcing for 2002, incorporating measurements over land and ocean. We use a Monte Carlo approach to account for uncertainties in aerosol measurements and in the algorithm used. Probability density functions obtained for the direct radiative forcing at the top of the atmosphere give a clear-sky, global, annual average of -1.9 W m(-2) with standard deviation, +/- 0.3 W m(-2). These results suggest that present-day direct radiative forcing is stronger than present model estimates, implying future atmospheric warming greater than is presently predicted, as aerosol emissions continue to decline.

  7. Direct measurement of the free energy by optical microscopy.

    PubMed

    Dullens, Roel P A; Aarts, Dirk G A L; Kegel, Willem K

    2006-01-17

    We report the direct measurement of thermodynamic properties of colloidal hard spheres by optical microscopy. By using confocal microscopy, we obtain three-dimensional snapshots of a colloidal hard-sphere suspension over a wide range of densities. From these snapshots, the available volume to insert an additional sphere and the surface area of that volume are determined, which are directly related to the thermodynamics of the system. This procedure enables us to measure in a direct and noninterfering way, in principle, all thermodynamic properties, here demonstrated for the pressure, the chemical potential, and the free-energy density of a colloidal hard-sphere suspension. The "visual" determination of thermodynamic quantities opens up the possibility to experimentally study the relation between thermodynamics and geometry in real space beyond the hard-sphere potential.

  8. Direct Measurement of Directional Disorder for Ciliary Metachronal Wave

    DTIC Science & Technology

    2007-11-02

    subjects [6]-[8]. Ciliary disorientation alone can lead to the clinical syndrome of primary ciliary dyskinesia (PCD) [9]. The directions based on...Orientation of respiratory tract cilia in patients with primary ciliary dyskinesia , bronchiectasis, and in normal subjects,” J. Clin. Pathol., vol. 42, pp...ciliary dyskinesia syndrome,” Am. J. Respir. Crit. Care Med., vol. 153, pp. 1123-1129, 1996. [10] L. Gheber and Z. Priel, “Metachronal activity of

  9. 77 FR 71695 - Secondary Direct Food Additives Permitted in Food for Human Consumption; Sodium...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-04

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Part 173 Secondary Direct Food Additives Permitted in Food for Human Consumption; Sodium Dodecylbenzenesulfonate AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is amending the food additive...

  10. 76 FR 11328 - Secondary Direct Food Additives Permitted in Food for Human Consumption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-02

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Part 173 Secondary Direct Food Additives Permitted in Food for Human Consumption AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is amending the food additive regulations to permit the use of...

  11. Asymmetric Direct 1,2-Addition of Aryl Grignard Reagents to Aryl Alkyl Ketones.

    PubMed

    Osakama, Kazuki; Nakajima, Makoto

    2016-01-15

    The enantioselective addition of Grignard reagents to ketones was promoted by a BINOL derivative bearing alkyl chains at the 3,3'-positions. This is the first asymmetric direct aryl Grignard addition to ketones reported to date. A variety of tertiary diaryl alcohols could be obtained in high yields and enantioselectivities without using any other metal source.

  12. Electronegative Gas Thruster - Direct Thrust Measurement Project

    NASA Technical Reports Server (NTRS)

    Dankanich, John (Principal Investigator); Aanesland, Ane; Polzin, Kurt; Walker, Mitchell

    2015-01-01

    This effort is an international collaboration and academic partnership to mature an innovative electric propulsion (EP) thruster concept to TRL 3 through direct thrust measurement. The initial target application is for Small Satellites, but can be extended to higher power. The Plasma propulsion with Electronegative GASES (PEGASES) concept simplifies ion thruster operation, eliminates a neutralizer requirement and should yield longer life capabilities and lower cost implementation over conventional gridded ion engines. The basic proof-of concept has been demonstrated and matured to TRL 2 over the past several years by researchers at the Laboratoire de Physique des Plasma in France. Due to the low maturity of the innovation, there are currently no domestic investments in electronegative gas thrusters anywhere within NASA, industry or academia. The end product of this Center Innovation Fund (CIF) project will be a validation of the proof-of-concept, maturation to TRL 3 and technology assessment report to summarize the potential for the PEGASES concept to supplant the incumbent technology. Information exchange with the foreign national will be one-way with the exception of the test results. Those test results will first go through a standard public release ITAR/export control review, and the results will be presented in a public technical forum, and the results will be presented in a public technical forum.

  13. Direct Measurement of Osteolysis in Man

    PubMed Central

    Hansen, James W.; Gordan, Gilbert S.; Prussin, Stanley G.

    1973-01-01

    Precise, direct measurement of bone calcium release (vo-) has been accomplished using a continuous tracer administration (CTA) technique. Dietary calcium (96.97% 40Ca) is replaced by 40Ca (99.991% 40Ca) and blood levels of the naturally occuring isotope 48Ca are monitored by neutron activation analysis as a function of time. 48Ca abundance falls as this isotope is excreted and only partially replaced by release from bone. After a suitable period, an asymptotic abundance of 48Ca in serum, E, is approached which is the fraction of the turnover rate of the rapidly exchangeable calcium pools coming from the skeleton (E = vo-/vt). E is determined with a standard error of 2%, providing a precise, sensitive index of vo-. 13 studies in three normal men and one postmenopausal woman receiving maintenance estrogen show large intersubject variations in parameters of calcium metabolism using both CTA and pulse tracer administration (PTA) plus balance techniques. Induced hypercalcemia results in a prolonged decrease in vo-. Glucocorticoid therapy initially and consistently induces a marked hypercalciuria while effects on most other parameters of calcium kinetics are variable. In two men E fell when testosterone was added to glucocorticoid treatment, consistent with the known antiosteolytic effect of androgens, despite the short period of study. PMID:4346006

  14. Cleaning and Cleanliness Measurement of Additive Manufactured Parts

    NASA Technical Reports Server (NTRS)

    Welker, Roger W.; Mitchell, Mark A.

    2015-01-01

    The successful acquisition and utilization of piece parts and assemblies for contamination sensitive applications requires application of cleanliness acceptance criteria. Contamination can be classified using many different schemes. One common scheme is classification as organic, ionic and particulate contaminants. These may be present in and on the surface of solid components and assemblies or may be dispersed in various gaseous or liquid media. This discussion will focus on insoluble particle contamination on the surface of piece parts and assemblies. Cleanliness of parts can be controlled using two strategies, referred to as gross cleanliness and precision cleanliness. Under a gross cleanliness strategy acceptance is based on visual cleanliness. This approach introduces a number of concerns that render it unsuitable for controlling cleanliness of high technology products. Under the precision cleanliness strategy, subjective, visual assessment of cleanliness is replaced by objective measurement of cleanliness. When a precision cleanliness strategy is adopted there naturally arises the question: How clean is clean enough? The six commonly used methods for establishing objective cleanliness acceptance limits will be discussed. Special emphasis shall focus on the use of multiple extraction, a technique that has been demonstrated for additively manufactured parts.

  15. Are gait variability and stability measures influenced by directional changes?

    PubMed Central

    2014-01-01

    Background Many gait variability and stability measures have been proposed in the literature, with the aim to quantify gait impairment, degree of neuro-motor control and balance disorders in healthy and pathological subjects. These measures are often obtained from lower trunk acceleration data, typically acquired during rectilinear gait, but relevant experimental protocols and data processing techniques lack in standardization. Since directional changes represent an essential aspect of gait, the assessment of their influence on such measures is essential for standardization. In addition, their investigation is needed to evaluate the applicability of these measures in laboratory trials and in daily life activity analysis. A further methodological aspect to be standardized concerns the assessment of the sampling frequency, which could affect stability measures. The aim of the present study was hence to assess if gait variability and stability measures are affected by directional changes, and to evaluate the influence of sampling frequency of trunk acceleration data on the results. Methods Fifty-one healthy young adults performed a 6-minute walk test along a 30 m straight pathway, turning by 180 deg at each end of the pathway. Nine variability and stability measures (Standard deviation, Coefficient of variation, Poincaré plots, maximum Floquet multipliers, short-term Lyapunov exponents, Recurrence quantification analysis, Multiscale entropy, Harmonic ratio and Index of harmonicity) were calculated on stride duration and trunk acceleration data (acquired at 100 Hz and 200 Hz) coming from straight walking windows and from windows including both straight walking and the directional change. Results Harmonic ratio was the only measure that resulted to be affected by directional changes and sampling frequency, decreasing with the presence of a directional change task. HR was affected in the AP and V directions for the 200 Hz, but only in AP direction for the 100 Hz group

  16. Direct Measurements of NOx Produced by Lightning

    NASA Astrophysics Data System (ADS)

    Rahman, M.; Cooray, V.; Rakov, V. A.; Uman, M. A.; Liyanage, P.; Decarlo, B. A.; Jerauld, J.; Olsen, R. C.

    2006-12-01

    We present the first direct measurements of NOx generated by lightning. In July 2005, three negative lightning flashes were triggered using the rocket-and-wire technique at the International Center for Lightning Research and Testing (ICLRT) at Camp Blanding, Florida. The NOx produced by these three rocket- triggered flashes was measured, using the chemiluminescence method, by isolating a 3-cm long section of the lightning channel within a discharge chamber whose volume was 0.77 m3. We measured NOx individually for the first flash, which was triggered on July 15, and cumulatively for the other two flashes, which were triggered within about eleven minutes of each other on July 31. The July 15 flash contained only an initial- stage current and no return strokes. Each of the July 31 flashes contained an initial-stage current and either one or two return strokes. The initial-stage current in each case had a duration in the range from 260 to 360 ms, and one return stroke in each July 31 flash was followed by a continuing current whose duration was greater than 40 ms. The NOx production by the July 15 flash without return strokes (total charge transfer of 77 C) was 2.0×10^{22} molecules per meter of lightning channel, and that by the two July 31 flashes with return strokes (total charge transfer of 108 C) was 2.4×10^{22} molecules per meter. The NOx production per unit charge for these two measurements was similar: 2.6×1020 and 2.2×1020 molecules per meter per coulomb. It appears that the NOx production is primarily from long-duration, steady currents, as opposed to microsecond-scale impulsive return stroke currents. This observation implies that cloud discharges, which transfer, on average, larger charges than ground discharges, but do not contain return strokes (although they do contain typically shorter and presumably smaller amplitude microsecond-scale pulses) may be as effective as (or more effective than) cloud-to-ground discharges in producing NOx in the

  17. Direct enantioselective conjugate addition of carboxylic acids with chiral lithium amides as traceless auxiliaries.

    PubMed

    Lu, Ping; Jackson, Jeffrey J; Eickhoff, John A; Zakarian, Armen

    2015-01-21

    Michael addition is a premier synthetic method for carbon-carbon and carbon-heteroatom bond formation. Using chiral dilithium amides as traceless auxiliaries, we report the direct enantioselective Michael addition of carboxylic acids. A free carboxyl group in the product provides versatility for further functionalization, and the chiral reagent can be readily recovered by extraction with aqueous acid. The method has been applied in the enantioselective total synthesis of the purported structure of pulveraven B.

  18. System for controllable magnetic measurement with direct field determination

    NASA Astrophysics Data System (ADS)

    Stupakov, O.

    2012-02-01

    This work describes a specially designed setup for magnetic hysteresis and Barkhausen noise measurements. The setup combines two main elements: an improved fast algorithm to control the waveform of magnetic induction and simultaneous direct determination of the magnetic field. The digital feedback algorithm uses only the previous measurement cycle to correct the magnetization voltage without any additional correlation parameter; it usually converges after several tens of cycles. The magnetic field is measured at the sample surface using a vertically mounted array of sensitive Hall sensors. Linear extrapolation of the tangential field profile to the sample surface determines the true waveform of the magnetic field. This unique combination of physically based control for both parameters of the magnetization process provides stable and reliable results, which are independent of a specified experimental configuration. This is illustrated for the industrially attractive measurements of non-oriented electrical steels with a 50 Hz sinusoidal induction waveform.

  19. Cleaning and Cleanliness Measurement of Additive Manufactured Parts

    NASA Technical Reports Server (NTRS)

    Mitchell, Mark A.; Edwards, Kevin

    2017-01-01

    Additive Manufacturing processes allow for the manufacture of complex three dimensional components that otherwise could not be manufactured. Post treatment processes require the removal of any remnant bulk powder that may become entrapped within small cavities and channels within a component. This project focuses on several gross cleaning methods and the verification metrics associated with additive manufactured parts for oxygen propulsion usage.

  20. Direct emissivity measurements of IR materials

    NASA Astrophysics Data System (ADS)

    Kisler, Yanina; Kupferberg, Lenn C.; Mackenzie, Gordon; Chen, Chia M.

    1999-07-01

    Emissivity measurements of ZnS, Sapphire, ALON, MgO, and Yttria were performed in 3.9-4.0 micrometers and 4.4-4.9 micrometers bands, for temperatures between 300 degrees C and 600 degrees C. The average radiance was measured over each waveband. Emissivity was calculated as the ratio of the radiance of the sample to that of a black body source at the same temperature. The results of the emissivity measurements for the above-mentioned materials will be reported. Measurement techniques that allowed increasing the dynamic range of the measurement and significantly reducing the noise will be discussed.

  1. Engineering Neurospora crassa for cellobionate production directly from cellulose without any enzyme addition

    USDA-ARS?s Scientific Manuscript database

    A previously engineered strain of N. crassa F5'ace-1'cre-1'ndvB) with six out of seven ß-glucosidase (bgl) genes, two transcription factors (cre1 and ace-1) and cellobionate phosphorylase (ndvB) deleted was able to produce cellobiose and cellobionate directly from cellulose without the addition of e...

  2. Catalytic asymmetric direct-type 1,4-addition reactions of simple amides.

    PubMed

    Suzuki, Hirotsugu; Sato, Io; Yamashita, Yasuhiro; Kobayashi, Shū

    2015-04-08

    The development of catalytic asymmetric direct-type reactions of less acidic carbonyl compounds such as amides and esters has been a challenging theme in organic chemistry for decades. Here we describe the asymmetric direct 1,4-addition reactions of simple amides with α,β-unsaturated carbonyl compounds using a catalytic amount of a novel chiral catalyst consisting of a potassium base and a macrocyclic chiral crown ether. The desired 1,5-dicarbonyl compounds were obtained in high yields with excellent diastereo- and enantioselectivities. This is the first example of a highly enantioselective catalytic direct-type reaction of simple amides. In addition, the structure of the chiral potassium catalyst has been investigated by X-ray crystallographic, dynamic (1)H NMR, and MALDI-TOF MS analyses.

  3. Latest Highlights from our Direct Measurement Video Collection

    NASA Astrophysics Data System (ADS)

    Vonk, M.; Bohacek, P. H.

    2014-12-01

    Recent advances in technology have made videos much easier to produce, edit, store, transfer, and view. This has spawned an explosion in a production of a wide variety of different types of pedagogical videos. But with the exception of student-made videos (which are often of poor quality) almost all of the educational videos being produced are passive. No matter how compelling the content, students are expected to simply sit and watch them. Because we feel that being engaged and active are necessary components of student learning, we have been working to create a free online library of Direct Measurement Videos (DMV's). These videos are short high-quality videos of real events, shot in a way that allows students to make measurements directly from the video. Instead of handing students a word problem about a car skidding on ice, we actually show them the car skidding on ice. We then ask them to measure the important quantities, make calculations based on those measurements and solve for unknowns. DMV's are more interesting than their word problem equivalents and frequently inspire further questions about the physics of the situation or about the uncertainty of the measurement in ways that word problems almost never do. We feel that it is simply impossible to a video of a roller coaster or a rocket and then argue that word problems are better. In this talk I will highlight some new additions to our DMV collection. This work is supported by NSF TUES award #1245268

  4. Detection of Additional Elements from the Mars Odyssey GRS Measurements

    NASA Astrophysics Data System (ADS)

    Evans, L. G.; Reedy, R. C.; Starr, R. D.; Kerry, K. E.; Boynton, W. V.

    2008-03-01

    Analysis of data by the Odyssey GRS has produced compositional maps for six elements. Analysis has produced preliminary results for Al, Ca, S, and U that may be mapped at lower resolutions. Additional results for Na, Mn, and Cr are more difficult, but possible.

  5. Oxygen fugacities directly measured in magmatic gases

    USGS Publications Warehouse

    Sato, M.; Wright, T.L.

    1966-01-01

    An electrochemical device was used to measure the fugacity of oxygen (fO2) in holes drilled through the crust of Makaopuhi lava lake, Kilauea Volcano, Hawaii. Results obtained within 6 months of the lake formation show that log fO2 normally varies linearly with the reciprocal of the absolute temperature, and that chemical changes occurring in the cooling tholeiitic basalt are reflected in the fO2 values measured in the holes.

  6. Oxygen fugacities directly measured in magmatic gases.

    PubMed

    Sato, M; Wright, T L

    1966-09-02

    An electrochemical device was used to measure the fugacity of oxygen (fo(o2)) in holes drilled through the crust of Makaopuhi lava lake, Kilauea Volcano, Hawaii. Results obtained within 6 months of the lake formation show that log fo(o2) normally varies linearly with the reciprocal of the absolute temperature, and that chemical changes occurring in the cooling tholeiitic basalt are reflected in the fo(o2) values measured in the holes.

  7. Airborne Spectral Measurements of Ocean Directional Reflectance

    NASA Technical Reports Server (NTRS)

    Gatebe, Charles K.; King, Michael D.; Lyapustin, Alexei; Arnold, G. Thomas; Redemann, Jens

    2004-01-01

    During summer of 2001 NASA's Cloud Absorption Radiometer (CAR) obtained measurement of ocean angular distribution of reflected radiation or BRDF (bidirectional reflectance distribution function) aboard the University of Washington Convair CV-580 research aircraft under cloud-free conditions. The measurements took place aver the Atlantic Ocean off the eastern seaboard of the U.S. in the vicinity of the Chesapeake Light Tower and at nearby National Oceanic and Atmospheric Administration (NOAA) Buoy Stations. The measurements were in support of CLAMS, Chesapeake Lighthouse and Aircraft Measurements for Satellites, field campaign that was primarily designed to validate and improve NASA's Earth Observing System (EOS) satellite data products being derived from three sensors: MODIS (MODerate Resolution Imaging Spectro-Radiometer), MISR (Multi-angle Imaging Spectro-Radiometer) and CERES (Clouds and Earth s Radiant Energy System). Because of the high resolution of the CAR measurements and its high sensitivity to detect weak ocean signals against a noisy background, results of radiance field above the ocean are seen in unprecedented detail. The study also attempts to validate the widely used Cox-Munk model for predicting reflectance from a rough ocean surface.

  8. Directional reflectance characterization facility and measurement methodology.

    PubMed

    McGuckin, B T; Haner, D A; Menzies, R T; Esproles, C; Brothers, A M

    1996-08-20

    A precision reflectance characterization facility, constructed specifically for the measurement of the bidirectional reflectance properties of Spectralon panels planned for use as in-flight calibrators on the NASA Multiangle Imaging Spectroradiometer (MISR) instrument is described. The incident linearly polarized radiation is provided at three laser wavelengths: 442, 632.8, and 859.9 nm. Each beam is collimated when incident on the Spectralon. The illuminated area of the panel is viewed with a silicon photodetector that revolves around the panel (360°) on a 30-cm boom extending from a common rotational axis. The reflected radiance detector signal is ratioed with the signal from a reference detector to minimize the effect of amplitude instabilities in the laser sources. This and other measures adopted to reduce noise have resulted in a bidirectional reflection function (BRF) calibration facility with a measurement precision with regard to a BRF measurement of ±0.002 at the 1ς confidence level. The Spectralon test piece panel is held in a computer-controlled three-axis rotational assembly capable of a full 360° rotation in the horizontal plane and 90° in the vertical. The angular positioning system has repeatability and resolution of 0.001°. Design details and an outline of the measurement methodology are presented.

  9. Advances in Directional Multicomponent Induction Borehole Measurements

    NASA Astrophysics Data System (ADS)

    Barber, T.

    2007-05-01

    New multicomponent EM wireline and logging-while-drilling (LWD) instruments are changing the way dip is determined and the accuracy of geosteering wells. A new wireline triaxial induction logging tool allows accurate dip and azimuth to be determined along with standard induction logs and the vertical and horizontal resistivities. The new directional LWD resistivity tool allows accurate geosteering within a reasonable formation thickness and indicated whether to steer up or down in real time. Both these instruments are dependent on 3D numerical EM modeling codes for tool design and data interpretation.

  10. Direct measurement of shear properties of microfibers

    SciTech Connect

    Behlow, H.; Saini, D.; Durham, L.; Simpson, J.; Skove, M. J.; Rao, A. M.; Oliveira, L.; Serkiz, S. M.

    2014-09-15

    As novel fibers with enhanced mechanical properties continue to be synthesized and developed, the ability to easily and accurately characterize these materials becomes increasingly important. Here we present a design for an inexpensive tabletop instrument to measure shear modulus (G) and other longitudinal shear properties of a micrometer-sized monofilament fiber sample, such as nonlinearities and hysteresis. This automated system applies twist to the sample and measures the resulting torque using a sensitive optical detector that tracks a torsion reference. The accuracy of the instrument was verified by measuring G for high purity copper and tungsten fibers, for which G is well known. Two industrially important fibers, IM7 carbon fiber and Kevlar{sup ®} 119, were also characterized with this system and were found to have G = 16.5 ± 2.1 and 2.42 ± 0.32 GPa, respectively.

  11. Direct measurement of shear properties of microfibers.

    PubMed

    Behlow, H; Saini, D; Oliveira, L; Durham, L; Simpson, J; Serkiz, S M; Skove, M J; Rao, A M

    2014-09-01

    As novel fibers with enhanced mechanical properties continue to be synthesized and developed, the ability to easily and accurately characterize these materials becomes increasingly important. Here we present a design for an inexpensive tabletop instrument to measure shear modulus (G) and other longitudinal shear properties of a micrometer-sized monofilament fiber sample, such as nonlinearities and hysteresis. This automated system applies twist to the sample and measures the resulting torque using a sensitive optical detector that tracks a torsion reference. The accuracy of the instrument was verified by measuring G for high purity copper and tungsten fibers, for which G is well known. Two industrially important fibers, IM7 carbon fiber and Kevlar(®) 119, were also characterized with this system and were found to have G = 16.5 ± 2.1 and 2.42 ± 0.32 GPa, respectively.

  12. Direct measurement of shear properties of microfibers

    NASA Astrophysics Data System (ADS)

    Behlow, H.; Saini, D.; Oliveira, L.; Durham, L.; Simpson, J.; Serkiz, S. M.; Skove, M. J.; Rao, A. M.

    2014-09-01

    As novel fibers with enhanced mechanical properties continue to be synthesized and developed, the ability to easily and accurately characterize these materials becomes increasingly important. Here we present a design for an inexpensive tabletop instrument to measure shear modulus (G) and other longitudinal shear properties of a micrometer-sized monofilament fiber sample, such as nonlinearities and hysteresis. This automated system applies twist to the sample and measures the resulting torque using a sensitive optical detector that tracks a torsion reference. The accuracy of the instrument was verified by measuring G for high purity copper and tungsten fibers, for which G is well known. Two industrially important fibers, IM7 carbon fiber and Kevlar® 119, were also characterized with this system and were found to have G = 16.5 ± 2.1 and 2.42 ± 0.32 GPa, respectively.

  13. Direct Measurement of Large, Diffuse, Optical Structures

    NASA Technical Reports Server (NTRS)

    Saif, Babak N.; Keski-Kuha, Ritva; Feinberg, Lee; Wyant, J. C.; Atkinson, C.

    2004-01-01

    Digital Speckle Pattern Interferometry (DSPI) is a well-established method for the measurement of diffuse objects in experimental mechanics. DSPIs are phase shifting interferometers. Three or four bucket temporal phase shifting algorithms are commonly used to provide phase shifting. These algorithms are sensitive to vibrations and can not be used to measure large optical structures far away from the interferometer. In this research a simultaneous phase shifted interferometer, PhaseCam product of 4D Technology Corporation in Tucson Arizona, is modified to be a Simultaneous phase shifted Digital Speckle Pattern Interferometer (SDSPI). Repeatability, dynamic range, and accuracy of the SDSPI are characterized by measuring a 5 cm x 5 cm carbon fiber coupon.

  14. Highly enantioselective direct vinylogous Michael addition of γ-butenolide to enals.

    PubMed

    Quintard, Adrien; Lefranc, Alice; Alexakis, Alexandre

    2011-03-18

    An unprecedented and simple direct vinylogous addition of deconjugated butenolide to enals has been developed in excellent stereoselectivities (>95% ee), with Aminal-PYrrolidine (APY) catalyst. This methodology allows for the efficient preparation of complex γ-butenolide from readily available renewable resources. Furthermore, preliminary mechanistic investigations have allowed for the better understanding of the origin of both stereoselectivities and of the observed high reactivities.

  15. Direct mapping of chemical oxidation of individual graphene sheets through dynamic force measurements at the nanoscale† †Electronic supplementary information (ESI) available: Further details regarding the measurement, UV/ozone treatment, adhesion measurement, graphene height characterization, detailed sample preparation, flow chart of the measurement, PeakForce mode, environmental stabilization and Raman spectra of treated samples. See DOI: 10.1039/c6nr05799c Click here for additional data file.

    PubMed Central

    Froning, Jens P.; Lazar, Petr; Pykal, Martin; Li, Qiang

    2017-01-01

    Graphene oxide is one of the most studied nanomaterials owing to its huge application potential in many fields, including biomedicine, sensing, drug delivery, optical and optoelectronic technologies. However, a detailed description of the chemical composition and the extent of oxidation in graphene oxide remains a key challenge affecting its applicability and further development of new applications. Here, we report direct monitoring of the chemical oxidation of an individual graphene flake during ultraviolet/ozone treatment through in situ atomic force microscopy based on dynamic force mapping. The results showed that graphene oxidation expanded from the graphene edges to the entire graphene surface. The interaction force mapping results correlated well with X-ray photoelectron spectroscopy data quantifying the degree of chemical oxidation. Density functional theory calculations confirmed the specific interaction forces measured between a silicon tip and graphene oxide. The developed methodology can be used as a simple protocol for evaluating the chemical functionalization of other two-dimensional materials with covalently attached functional groups. PMID:27735008

  16. Direct Measurement of the Top Quark Mass

    NASA Astrophysics Data System (ADS)

    Abachi, S.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adam, I.; Adams, D. L.; Adams, M.; Ahn, S.; Aihara, H.; Alves, G. A.; Amidi, E.; Amos, N.; Anderson, E. W.; Astur, R.; Baarmand, M. M.; Baden, A.; Balamurali, V.; Balderston, J.; Baldin, B.; Banerjee, S.; Bantly, J.; Barberis, E.; Bartlett, J. F.; Bazizi, K.; Belyaev, A.; Beri, S. B.; Bertram, I.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Biswas, N.; Blazey, G.; Blessing, S.; Bloom, P.; Boehnlein, A.; Bojko, N. I.; Borcherding, F.; Borders, J.; Boswell, C.; Brandt, A.; Brock, R.; Bross, A.; Buchholz, D.; Burtovoi, V. S.; Butler, J. M.; Carvalho, W.; Casey, D.; Castilla-Valdez, H.; Chakraborty, D.; Chang, S.-M.; Chekulaev, S. V.; Chen, L.-P.; Chen, W.; Choi, S.; Chopra, S.; Choudhary, B. C.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Cobau, W. G.; Cochran, J.; Cooper, W. E.; Cretsinger, C.; Cullen-Vidal, D.; Cummings, M. A.; Cutts, D.; Dahl, O. I.; Davis, K.; de, K.; del Signore, K.; Demarteau, M.; Denisov, D.; Denisov, S. P.; Diehl, H. T.; Diesburg, M.; di Loreto, G.; Draper, P.; Drinkard, J.; Ducros, Y.; Dudko, L. V.; Dugad, S. R.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Evdokimov, V. N.; Fahland, T.; Fatyga, M.; Fatyga, M. K.; Featherly, J.; Feher, S.; Fein, D.; Ferbel, T.; Finocchiaro, G.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Forden, G. E.; Fortner, M.; Frame, K. C.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Gartung, P.; Geld, T. L.; Genik, R. J., II; Genser, K.; Gerber, C. E.; Gibbard, B.; Glenn, S.; Gobbi, B.; Goforth, M.; Goldschmidt, A.; Gómez, B.; Gómez, G.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Goussiou, A.; Graf, N.; Grannis, P. D.; Green, D. R.; Green, J.; Greenlee, H.; Grim, G.; Grinstein, S.; Grossman, N.; Grudberg, P.; Grünendahl, S.; Guglielmo, G.; Guida, J. A.; Guida, J. M.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, P.; Gutnikov, Y. E.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hahn, K. S.; Hall, R. E.; Hansen, S.; Hauptman, J. M.; Hedin, D.; Heinson, A. P.; Heintz, U.; Hernández-Montoya, R.; Heuring, T.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hoftun, J. S.; Hsieh, F.; Hu, Ting; Hu, Tong; Huehn, T.; Ito, A. S.; James, E.; Jaques, J.; Jerger, S. A.; Jesik, R.; Jiang, J. Z.-Y.; Joffe-Minor, T.; Johns, K.; Johnson, M.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Jun, S. Y.; Jung, C. K.; Kahn, S.; Kalbfleisch, G.; Kang, J. S.; Kehoe, R.; Kelly, M. L.; Kim, C. L.; Kim, S. K.; Klatchko, A.; Klima, B.; Klopfenstein, C.; Klyukhin, V. I.; Kochetkov, V. I.; Kohli, J. M.; Koltick, D.; Kostritskiy, A. V.; Kotcher, J.; Kotwal, A. V.; Kourlas, J.; Kozelov, A. V.; Kozlovski, E. A.; Krane, J.; Krishnaswamy, M. R.; Krzywdzinski, S.; Kunori, S.; Lami, S.; Lan, H.; Lander, R.; Landry, F.; Landsberg, G.; Lauer, B.; Leflat, A.; Li, H.; Li, J.; Li-Demarteau, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Liu, Q.; Liu, Y. C.; Lobkowicz, F.; Loken, S. C.; Lökös, S.; Lueking, L.; Lyon, A. L.; Maciel, A. K.; Madaras, R. J.; Madden, R.; Magaña-Mendoza, L.; Mani, S.; Mao, H. S.; Markeloff, R.; Markosky, L.; Marshall, T.; Martin, M. I.; Mauritz, K. M.; May, B.; Mayorov, A. A.; McCarthy, R.; McDonald, J.; McKibben, T.; McKinley, J.; McMahon, T.; Melanson, H. L.; Merkin, M.; Merritt, K. W.; Miettinen, H.; Mincer, A.; de Miranda, J. M.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Mooney, P.; da Motta, H.; Murphy, C.; Nang, F.; Narain, M.; Narasimham, V. S.; Narayanan, A.; Neal, H. A.; Negret, J. P.; Nemethy, P.; Nes̆iĆ, D.; Nicola, M.; Norman, D.; Oesch, L.; Oguri, V.; Oltman, E.; Oshima, N.; Owen, D.; Padley, P.; Pang, M.; Para, A.; Park, Y. M.; Partridge, R.; Parua, N.; Paterno, M.; Perkins, J.; Peters, M.; Piegaia, R.; Piekarz, H.; Pischalnikov, Y.; Podstavkov, V. M.; Pope, B. G.; Prosper, H. B.; Protopopescu, S.; Pus̆eljić, D.; Qian, J.; Quintas, P. Z.; Raja, R.; Rajagopalan, S.; Ramirez, O.; Rapidis, P. A.; Rasmussen, L.; Reucroft, S.; Rijssenbeek, M.; Rockwell, T.; Roe, N. A.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Sánchez-Hernández, A.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Sculli, J.; Shabalina, E.; Shaffer, C.; Shankar, H. C.; Shivpuri, R. K.; Shupe, M.; Singh, H.; Singh, J. B.; Sirotenko, V.; Smart, W.; Smith, A.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Sood, P. M.; Sosebee, M.; Sotnikova, N.; Souza, M.; Spadafora, A. L.; Stephens, R. W.; Stevenson, M. L.; Stewart, D.; Stoianova, D. A.; Stoker, D.; Strauss, M.; Streets, K.; Strovink, M.; Sznajder, A.; Tamburello, P.; Tarazi, J.; Tartaglia, M.; Thomas, T. L.; Thompson, J.; Trippe, T. G.; Tuts, P. M.; Varelas, N.; Varnes, E. W.; Vititoe, D.; Volkov, A. A.; Vorobiev, A. P.; Wahl, H. D.; Wang, G.; Warchol, J.; Watts, G.; Wayne, M.; Weerts, H.; White, A.; White, J. T.; Wightman, J. A.; Willis, S.; Wimpenny, S. J.; Wirjawan, J. V.; Womersley, J.; Won, E.; Wood, D. R.; Xu, H.; Yamada, R.; Yamin, P.; Yanagisawa, C.; Yang, J.; Yasuda, T.; Yepes, P.; Yoshikawa, C.; Youssef, S.; Yu, J.; Yu, Y.; Zhu, Q.; Zhu, Z. H.; Zieminska, D.; Zieminski, A.; Zverev, E. G.; Zylberstejn, A.

    1997-08-01

    We measure the top quark mass mt using tt¯ pairs produced in the D0 detector by s = 1.8 TeVpp¯ collisions in a 125 pb-1 exposure at the Fermilab Tevatron. We make a two constraint fit to mt in tt¯-->bW+b¯W- final states with one W decaying to qq¯ and the other to eν or μν. Events are binned in fit mass versus a measure of probability for events to be signal rather than background. Likelihood fits to the data yield mt = 173.3+/-5.6\\(stat\\)+/-6.2\\(syst\\) GeV/c2.

  17. Direct measurements of the atmospheric conduction current

    NASA Technical Reports Server (NTRS)

    Burke, H. K.; Few, A. A.

    1978-01-01

    A method of measuring the atmospheric conduction current above the ground has been employed to obtain data for 12 weeks during the first half of 1974. The instrument consists of a split aluminum sphere suspended by insulated wires to a wooden frame. The measuring electronics and the transmitter are enclosed within the spherical structure. The interaction of the instrument with its atmospheric electrical environment is analyzed, and it is shown that in steady state conditions, predictable differences in the instrumentally measured currents and the atmospheric conduction current will be less than 5% and in the nonsteady state situations the difference is less than 20%. Diurnal variations, a probable winter-summer variation, sunrise, and fog effects were observed for the data obtained during fair-weather conditions. Disturbed weather data are interpreted for the effects of low clouds on the atmospheric current. The charge concentrations within overcast clouds sufficient to produce the observed reversed atmospheric currents are estimated to be small in relation to values in thunderclouds.

  18. Direct measurements of the atmospheric conduction current

    NASA Technical Reports Server (NTRS)

    Burke, H. K.; Few, A. A.

    1978-01-01

    A method of measuring the atmospheric conduction current above the ground has been employed to obtain data for 12 weeks during the first half of 1974. The instrument consists of a split aluminum sphere suspended by insulated wires to a wooden frame. The measuring electronics and the transmitter are enclosed within the spherical structure. The interaction of the instrument with its atmospheric electrical environment is analyzed, and it is shown that in steady state conditions, predictable differences in the instrumentally measured currents and the atmospheric conduction current will be less than 5% and in the nonsteady state situations the difference is less than 20%. Diurnal variations, a probable winter-summer variation, sunrise, and fog effects were observed for the data obtained during fair-weather conditions. Disturbed weather data are interpreted for the effects of low clouds on the atmospheric current. The charge concentrations within overcast clouds sufficient to produce the observed reversed atmospheric currents are estimated to be small in relation to values in thunderclouds.

  19. Direct Optofluidic Measurement of the Lipid Permeability of Fluoroquinolones

    PubMed Central

    Cama, Jehangir; Schaich, Michael; Al Nahas, Kareem; Hernández-Ainsa, Silvia; Pagliara, Stefano; Keyser, Ulrich F.

    2016-01-01

    Quantifying drug permeability across lipid membranes is crucial for drug development. In addition, reduced membrane permeability is a leading cause of antibiotic resistance in bacteria, and hence there is a need for new technologies that can quantify antibiotic transport across biological membranes. We recently developed an optofluidic assay that directly determines the permeability coefficient of autofluorescent drug molecules across lipid membranes. Using ultraviolet fluorescence microscopy, we directly track drug accumulation in giant lipid vesicles as they traverse a microfluidic device while exposed to the drug. Importantly, our measurement does not require the knowledge of the octanol partition coefficient of the drug – we directly determine the permeability coefficient for the specific drug-lipid system. In this work, we report measurements on a range of fluoroquinolone antibiotics and find that their pH dependent lipid permeability can span over two orders of magnitude. We describe various technical improvements for our assay, and provide a new graphical user interface for data analysis to make the technology easier to use for the wider community. PMID:27604156

  20. MERCURY MEASUREMENTS USING DIRECT-ANALYZER ...

    EPA Pesticide Factsheets

    Under EPA's Water Quality Research Program, exposure studies are needed to determine how well control strategies and guidance are working. Consequently, reliable and convenient techniques that minimize waste production are of special interest. While traditional methods for determining mercury in solid samples involve the use of aggressive chemicals to dissolve the matrix and the use of other chemicals to properly reduce the mercury to the volatile elemental form, pyrolysis-based analyzers can be used by directly weighing the solid in a sampling boat and initiating the instrumental analysis for total mercury. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at con

  1. The direct anti-Markovnikov addition of mineral acids to styrenes

    NASA Astrophysics Data System (ADS)

    Wilger, Dale J.; Grandjean, Jean-Marc M.; Lammert, Taylor R.; Nicewicz, David A.

    2014-08-01

    The direct anti-Markovnikov addition of strong Brønsted acids to alkenes remains an unsolved problem in synthetic chemistry. Here, we report an efficient organic photoredox catalyst system for the addition of HCl, HF and also phosphoric and sulfonic acids to alkenes, with complete regioselectivity. These transformations were developed using a photoredox catalyst in conjunction with a redox-active hydrogen atom donor. The nucleophile counterion plays a critical role by ensuring high reactivity, with 2,6-lutidinium salts typically furnishing the best results. The nature of the redox-active hydrogen atom donor is also consequential, with 4-methoxythiophenol providing the best reactivity when 2,6-lutidinium salts are used. A novel acridinium sensitizer provides enhanced reactivity within several of the more challenging reaction manifolds. This Article demonstrates how nucleophilic addition reactions mediated by photoredox catalysis can change the way electrophilic and homofugal precursors are constructed.

  2. Alternative fundamental measure theory for additive hard sphere mixtures.

    PubMed

    Malijevský, Alexandr

    2006-11-21

    The purpose of this short paper is to present an alternative fundamental measure theory (FMT) for hard sphere mixtures. Keeping the main features of the original Rosenfeld's FMT [Phys. Rev. Lett. 63, 980 (1989)] and using the dimensional and the low-density limit conditions a new functional is derived incorporating Boublik's multicomponent extension [Mol. Phys. 59, 371 (1986)] of highly accurate Kolafa's equation of state for pure hard spheres. We test the theory for pure hard spheres and hard sphere mixtures near a planar hard wall and compare the results with the original Rosenfeld's FMT and one of its modifications and with new very accurate simulation data. The test reveals an excellent agreement between the results based on the alternative FMT and simulation data for density profile near a contact and some improvement over the original Rosenfeld's FMT and its modification at the contact region.

  3. 78 FR 73434 - Food Additives Permitted for Direct Addition to Food for Human Consumption; Acacia (Gum Arabic)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-06

    ... to Food for Human Consumption; Acacia (Gum Arabic) AGENCY: Food and Drug Administration, HHS. ACTION... regulations to provide for the expanded safe use of acacia (gum arabic) in foods. This action is in response... ] additive regulations in Sec. 172.780, Acacia (gum arabic) (21 CFR 172.780) to provide for the expanded safe...

  4. Gust Alleviation Using Direct Gust Measurement

    NASA Technical Reports Server (NTRS)

    Hoppe, Sven Marco

    2000-01-01

    The increasing competition in the market of civil aircraft leads to operating efficiency and passenger comfort being very important sales arguments. Continuous developments in jet propulsion technology helped to reduce energy consumption, as well as noise and vibrations due to the engines. The main problem with respect to ride comfort is, however, the transmittance of accelerations and jerkiness imposed by atmospheric turbulence from the wings to the fuselage. This 'gust' is also a design constraint: Light airplane structures help to save, energy, but are more critical to resist the loads imposed by turbulence. For both reasons, efficient gust alleviation is necessary to improve the performance of modern aircraft. Gust can be seen as a change in the angle of attack or as an additional varying vertical component of the headwind. The effect of gust can be very strong, since the same aerodynamic forces that keep the airplane flying are involved. Event though the frequency range of those changes is quite low, it is impossible for the pilot to alleviate gust manually. Besides, most of the time during the flight, the, autopilot maintains course and the attitude of flight. Certainly, most autopilots should be capable of damping the roughest parts of turbulence, but they are unable to provide satisfactory results in that field. A promising extension should be the application of subsidiary, control, where the inner (faster) control loop alleviates turbulence and the outer (slower) loop controls the attitude of flight. Besides the mentioned ride comfort, another reason for gust alleviation with respect to the fuselage is the sensibility of electrical devices to vibration and high values of acceleration. Many modern airplane designs--especially inherently instable military aircraft--are highly dependent on avionics. The lifetime and the reliability of these systems is thus essential.

  5. Cleaning and Cleanliness Measurement of Additive Manufactured Parts

    NASA Technical Reports Server (NTRS)

    Mitchell, Mark A.; Raley, Randy

    2016-01-01

    The successful acquisition and utilization of piece parts and assemblies for contamination sensitive applications requires application of cleanliness acceptance criteria. Contamination can be classified using many different schemes. One common scheme is classification as organic, ionic and particulate contaminants. These may be present in and on the surface of solid components and assemblies or may be dispersed in various gaseous or liquid media. This discussion will focus on insoluble particle contamination on the surfaces of piece parts and assemblies. Cleanliness of parts can be controlled using two strategies, referred to as gross cleanliness and precision cleanliness. Under a gross cleanliness strategy acceptance is based on visual cleanliness. This approach introduces a number of concerns that render it unsuitable for controlling cleanliness of high technology products. Under the precision cleanliness strategy, subjective, visual assessment of cleanliness is replaced by objective measurement of cleanliness. When a precision cleanliness strategy is adopted there naturally arises the question: How clean is clean enough? The methods for establishing objective cleanliness acceptance limits will be discussed.

  6. Direct measurements of the magnetic entropy change.

    PubMed

    Nielsen, K K; Bez, H N; von Moos, L; Bjørk, R; Eriksen, D; Bahl, C R H

    2015-10-01

    An experimental device that can accurately measure the magnetic entropy change, Δs, as a function of temperature, T, and magnetic field, H, is presented. The magnetic field source is in this case a set of counter-rotating concentric Halbach-type magnets, which produce a highly homogeneous applied field with constant orientation. The field may be varied from 0 to 1.5 T in a continuous way. The temperature stability of the system is controlled to within ±10 mK and the standard range for the current setup is from 230 K to 330 K. The device is under high vacuum and we show that thermal losses to the ambient are negligible in terms of the calorimetric determination of the magnetic entropy change, while the losses cannot be ignored when correcting for the actual sample temperature. We apply the device to two different types of samples; one is commercial grade Gd, i.e., a pure second-order phase transition material, while the other is Gd5Si2Ge2, a first order magnetic phase transition material. We demonstrate the device's ability to fully capture the thermal hysteresis of the latter sample by following appropriate thermal resetting scheme and magnetic resetting scheme.

  7. Direct absorption measurements in thin rods and optical fibers

    NASA Astrophysics Data System (ADS)

    Mühlig, Christian; Bublitz, Simon; Lorenz, Martin

    2015-11-01

    We report on the first realization of direct absorption measurements in thin rods and optical fibers using the laser induced deflection (LID) technique. Typically, along the fiber processing chain more or less technology steps are able to introduce additional losses to the starting material. After the final processing, the fibers are commonly characterized regarding losses using the so-called cut-back technique in combination with spectrometers. This, however, only serves for a total loss determination. For optimization of the fiber processing, it would be of great interest to not only distinguish between different loss mechanisms but also have a better understanding of possible causes. For measuring the absorption losses along the fiber processing, a particular concept for the LID technique is introduced and requirements, calibration procedure as well as first results are presented. It allows to measure thin rods, e.g. during preform manufacturing, as well as optical fibers. In addition, the results show the prospects to also apply the new concept to topics like characterizing unwanted absorption after fiber splicing or Bragg grating inscription.

  8. Measurement of electromagnetic properties of powder and solid metal materials for additive manufacturing

    NASA Astrophysics Data System (ADS)

    Todorov, Evgueni Iordanov

    2017-04-01

    The lack of validated nondestructive evaluation (NDE) techniques for examination during and after additive manufacturing (AM) component fabrication is one of the obstacles in the way of broadening use of AM for critical applications. Knowledge of electromagnetic properties of powder (e.g. feedstock) and solid AM metal components is necessary to evaluate and deploy electromagnetic NDE modalities for examination of AM components. The objective of this research study was to develop and implement techniques for measurement of powder and solid metal electromagnetic properties. Three materials were selected - Inconel 625, duplex stainless steel 2205, and carbon steel 4140. The powder properties were measured with alternate current (AC) model based eddy current technique and direct current (DC) resistivity measurements. The solid metal properties were measured with DC resistivity measurements, DC magnetic techniques, and AC model based eddy current technique. Initial magnetic permeability and electrical conductivity were acquired for both powder and solid metal. Additional magnetic properties such as maximum permeability, coercivity, retentivity, and others were acquired for 2205 and 4140. Two groups of specimens were tested along the build length and width respectively to investigate for possible anisotropy. There was no significant difference or anisotropy when comparing measurements acquired along build length to those along the width. A trend in AC measurements might be associated with build geometry. Powder electrical conductivity was very low and difficult to estimate reliably with techniques used in the study. The agreement between various techniques was very good where adequate comparison was possible.

  9. Beamforming for directional sources: additional estimator and evaluation of performance under different acoustic scenarios.

    PubMed

    Bouchard, Christian; Havelock, David I; Bouchard, Martin

    2011-04-01

    Beamforming is done with an array of sensors to achieve a directional or spatially-specific response by using a model of the arriving wavefront. Conventionally, a plane wave or point source model is used and this can cause decreased array gain or even total breakdown of beamforming when the source is directional. To avoid this, the authors proposed in recent work an alternative beamforming method which defines a set of "sub-beamformers," each designed to respond to a different spatial mode of the source. The outputs of the individual sub-beamformers are combined in a weighted sum to give an overall output of better quality than that of a monopole beamformer. This paper extends the previous work by introducing an additional estimator for the weighted sum and by presenting simulation results to demonstrate the relative performance of the proposed method and the different estimators for a directional source in the presence of diffuse noise, reverberation, and an interfering source. Gain optimization subject to a constraint on the white-noise gain with the proposed beamforming method is also introduced. Generally, when beamforming on directional sources, the proposed method outperforms beamforming with a point source model when the input signal-to-noise ratio (SNR) is 0 dB or higher.

  10. Hydrodynamic Instability in High-speed Direct Laser Deposition for Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Turichin, Gleb; Zemlyakov, Evgeny; Klimova, Olga; Babkin, Konstantin

    High speed direct laser deposition, when product forms from metal powder, transferred by gas-powder jet, supplied coaxially or non-coaxially to focused laser beam, in one of most prospective additive technologies for production parts for aircraft engines. The limit of process productivity is connected with development of hydrodynamic instability of the melt pool in conditions of high power laser action and material supply by gas-powder jet. Theoretical analysis and experiments allowed clarified a physical nature of instability appearance, determine a stability conditions and invent a methods which allow avoid instability in deposition process. Nozzles for direct laser deposition, designed with consideration of stability conditions, allow get a level of process productivity more then 2 kg/h. The developed technology of deposition and technological equipment, based on high power fiber laser, has been used for manufacturing of parts for "high temperature" unit of aircraft engine.

  11. Canopy Components Temperature Retrieval through Bayesian inversion of Directional measurements

    NASA Astrophysics Data System (ADS)

    Timmermans, J.; Verhoef, W.; van der Tol, C.; Jia, L.; Su, Z.

    2008-12-01

    In the calculation of Evapotranspiration the kinematic temperature of the individual canopy components plays a crucial role. Most remote sensing algorithms, like SEBAL and SEBS, use a single surface temperature to calculate the evapotranspiration. These algorithms break down when used for canopies with a heterogeneous kinematic temperature profile. A two-source or four-source approach would result in much more realistic values of the evapotranspiration. Single view Nadir looking sensors are not able to extract the multiple kinetic temperatures with high precision. The use of multi-directional sensors is therefore essential. A bi-angular setup is sufficient to separate soil and canopy temperatures (e.g. Jia et al. 2003). For separation of sunlit and shaded soil or vegetation temperatures measurements at additional angles are needed. Calculation of the component temperatures from measured thermal radiances requires the use of more sophisticated radiative transfer models, because the use of fractional vegetation cover alone is no longer sufficient for an inversion scheme for four components. The radiative transfer model used for the calculation of the component temperatures was the four stream SAIL radiative transfer model (Verhoef et al. 2007). We present the algorithm used and the results obtained for the Bayesian inversion. The results were obtained using several directional measurement configurations. The configurations were chosen such to represent various present and future satellite-borne sensors. In this way the configurations give a clear indication of the possibilities of multi-directional thermal remote sensing. References Jia. L. Li, Z. -I., Menenti, M., Su, Z., Verhoef, W. and Wan, Z. (2003), "A practical algorithm to infer soil and foliage component temperatures from bi-angular ATSR-2 data", International Journal of Remote Sensing, 24:23, 4739-4760. Verhoef, W. Jia, L. Xiao, Q. Su, Z., (2007), "Unified optical-thermal four-stream radiative transfer

  12. Measurement of powder bed density in powder bed fusion additive manufacturing processes

    NASA Astrophysics Data System (ADS)

    Jacob, G.; Donmez, A.; Slotwinski, J.; Moylan, S.

    2016-11-01

    Many factors influence the performance of additive manufacturing (AM) processes, resulting in a high degree of variation in process outcomes. Therefore, quantifying these factors and their correlations to process outcomes are important challenges to overcome to enable widespread adoption of emerging AM technologies. In the powder bed fusion AM process, the density of the powder layers in the powder bed is a key influencing factor. This paper introduces a method to determine the powder bed density (PBD) during the powder bed fusion (PBF) process. A complete uncertainty analysis associated with the measurement method was also described. The resulting expanded measurement uncertainty, U PBD (k  =  2), was determined as 0.004 g · cm-3. It was shown that this expanded measurement uncertainty is about three orders of magnitude smaller than the typical powder bed density. This method enables establishing correlations between the changes in PBD and the direction of motion of the powder recoating arm.

  13. Direct Measurement of the Density Matrix of a Quantum System

    NASA Astrophysics Data System (ADS)

    Thekkadath, G. S.; Giner, L.; Chalich, Y.; Horton, M. J.; Banker, J.; Lundeen, J. S.

    2016-09-01

    One drawback of conventional quantum state tomography is that it does not readily provide access to single density matrix elements since it requires a global reconstruction. Here, we experimentally demonstrate a scheme that can be used to directly measure individual density matrix elements of general quantum states. The scheme relies on measuring a sequence of three observables, each complementary to the last. The first two measurements are made weak to minimize the disturbance they cause to the state, while the final measurement is strong. We perform this joint measurement on polarized photons in pure and mixed states to directly measure their density matrix. The weak measurements are achieved using two walk-off crystals, each inducing a polarization-dependent spatial shift that couples the spatial and polarization degrees of freedom of the photons. This direct measurement method provides an operational meaning to the density matrix and promises to be especially useful for large dimensional states.

  14. Tropospheric Wind Profile Measurements with a Direct Detection Doppler Lidar

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce M.; Li, Steven X.; Korb, C. Laurence; Chen, Huailin; Mathur, Savyasachee

    1998-01-01

    Research has established the importance of global tropospheric wind measurements for large scale improvements in numerical weather prediction. In addition, global wind measurements provide data that are fundamental to the understanding and prediction of global climate change. These tasks are closely linked with the goals of the NASA Earth Science Enterprise and Global Climate Change programs. NASA Goddard has been actively involved in the development of direct detection Doppler lidar methods and technologies to meet the wind observing needs of the atmospheric science community. In this paper we describe a recently developed prototype wind lidar system using a direct detection Doppler technique for measuring wind profiles from the surface through the troposphere. This system uses a pulsed ND:YAG laser operating at 1064 nm as the transmitter. The laser pulse is directed to the atmosphere using a 40 cm diameter scan mirror. The portion of the laser energy backscattered from aerosols and molecules is collected by a 40 cm diameter telescope and coupled via fiber optics into the Doppler receiver. Single photon counting APD's are used to detect the atmospheric backscattered signal. The principle element of the receiver is a dual bandpass tunable Fabry Perot etalon which analyzes the Doppler shift of the incoming laser signal using the double edge technique. The double edge technique uses two high resolution optical filters having bandpasses offset relative to one another such that the 'edge' of the first filter's transmission function crosses that of the second at the half power point. The outgoing laser frequency is located approximately at the crossover point. Due to the opposite going slopes of the edges, a Doppler shift in the atmospheric backscattered laser frequency produces a positive change in signal for one filter and a negative change in the second filter. Taking the ratio of the two edge channel signals yields a result which is directly proportional to the

  15. Tropospheric Wind Profile Measurements with a Direct Detection Doppler Lidar

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce M.; Li, Steven X.; Korb, C. Laurence; Chen, Huailin; Mathur, Savyasachee

    1998-01-01

    Research has established the importance of global tropospheric wind measurements for large scale improvements in numerical weather prediction. In addition, global wind measurements provide data that are fundamental to the understanding and prediction of global climate change. These tasks are closely linked with the goals of the NASA Earth Science Enterprise and Global Climate Change programs. NASA Goddard has been actively involved in the development of direct detection Doppler lidar methods and technologies to meet the wind observing needs of the atmospheric science community. In this paper we describe a recently developed prototype wind lidar system using a direct detection Doppler technique for measuring wind profiles from the surface through the troposphere. This system uses a pulsed ND:YAG laser operating at 1064 nm as the transmitter. The laser pulse is directed to the atmosphere using a 40 cm diameter scan mirror. The portion of the laser energy backscattered from aerosols and molecules is collected by a 40 cm diameter telescope and coupled via fiber optics into the Doppler receiver. Single photon counting APD's are used to detect the atmospheric backscattered signal. The principle element of the receiver is a dual bandpass tunable Fabry Perot etalon which analyzes the Doppler shift of the incoming laser signal using the double edge technique. The double edge technique uses two high resolution optical filters having bandpasses offset relative to one another such that the 'edge' of the first filter's transmission function crosses that of the second at the half power point. The outgoing laser frequency is located approximately at the crossover point. Due to the opposite going slopes of the edges, a Doppler shift in the atmospheric backscattered laser frequency produces a positive change in signal for one filter and a negative change in the second filter. Taking the ratio of the two edge channel signals yields a result which is directly proportional to the

  16. Direct Tests of Measurement Uncertainty Relations: What It Takes

    NASA Astrophysics Data System (ADS)

    Busch, Paul; Stevens, Neil

    2015-02-01

    The uncertainty principle being a cornerstone of quantum mechanics, it is surprising that, in nearly 90 years, there have been no direct tests of measurement uncertainty relations. This lacuna was due to the absence of two essential ingredients: appropriate measures of measurement error (and disturbance) and precise formulations of such relations that are universally valid and directly testable. We formulate two distinct forms of direct tests, based on different measures of error. We present a prototype protocol for a direct test of measurement uncertainty relations in terms of value deviation errors (hitherto considered nonfeasible), highlighting the lack of universality of these relations. This shows that the formulation of universal, directly testable measurement uncertainty relations for state-dependent error measures remains an important open problem. Recent experiments that were claimed to constitute invalidations of Heisenberg's error-disturbance relation, are shown to conform with the spirit of Heisenberg's principle if interpreted as direct tests of measurement uncertainty relations for error measures that quantify distances between observables.

  17. Direct tests of measurement uncertainty relations: what it takes.

    PubMed

    Busch, Paul; Stevens, Neil

    2015-02-20

    The uncertainty principle being a cornerstone of quantum mechanics, it is surprising that, in nearly 90 years, there have been no direct tests of measurement uncertainty relations. This lacuna was due to the absence of two essential ingredients: appropriate measures of measurement error (and disturbance) and precise formulations of such relations that are universally valid and directly testable. We formulate two distinct forms of direct tests, based on different measures of error. We present a prototype protocol for a direct test of measurement uncertainty relations in terms of value deviation errors (hitherto considered nonfeasible), highlighting the lack of universality of these relations. This shows that the formulation of universal, directly testable measurement uncertainty relations for state-dependent error measures remains an important open problem. Recent experiments that were claimed to constitute invalidations of Heisenberg's error-disturbance relation, are shown to conform with the spirit of Heisenberg's principle if interpreted as direct tests of measurement uncertainty relations for error measures that quantify distances between observables.

  18. Direct exfoliation of graphite in water with addition of ammonia solution.

    PubMed

    Ma, Han; Shen, Zhigang; Yi, Min; Ben, Shuang; Liang, Shuaishuai; Liu, Lei; Zhang, Yixiang; Zhang, Xiaojing; Ma, Shulin

    2017-10-01

    To bring graphene closer to its real-world applications, finding a green, low-cost, environment-friendly and less toxic solvent for production of high-quality graphene is highly demanded. However, water, the most widely used green solvent, is generally considered to be a poor solvent for hydrophobic graphene. In this study, we exfoliate graphene nanosheets directly in basic water without surfactants, polymers or organic solvents. The addition of a small amount of ammonia solution achieves the exfoliation of few-layer graphene nanosheets from pristine graphite. Diverse characterization methods are employed to investigate the morphology and quality of as-prepared graphene sheets. The release of gaseous ammonia plays the key role in exfoliation of graphene. The concentration of stable graphene dispersions can reach 0.058mg/mL. Copyright © 2017. Published by Elsevier Inc.

  19. Effects of NaOH addition on performance of the direct hydrazine fuel cell

    NASA Astrophysics Data System (ADS)

    Yin, Wen Xia; Li, Zhou Peng; Zhu, Jing Ke; Qin, Hai Ying

    In this work, we suggested a figuration of the direct hydrazine fuel cell (DHFC) using non-precious metals as the anode catalyst, ion exchange membranes as the electrolyte and alkaline hydrazine solutions as the fuel. NaOH addition in the anolyte effectively improved the open circuit voltage and the performance of the DHFC. A power density of 84 mW cm -2 has been achieved when operating the cell at room temperature. It was found that the cell performance was mainly influenced by anode polarization when using alkaline N 2H 4 solutions with low NaOH concentrations. However, when using alkaline N 2H 4 solutions with high NaOH concentrations as the fuel, the cell performance was mainly influenced by cathode polarization.

  20. Rab8 directs furrow ingression and membrane addition during epithelial formation in Drosophila melanogaster.

    PubMed

    Mavor, Lauren M; Miao, Hui; Zuo, Zhongyuan; Holly, Ryan M; Xie, Yi; Loerke, Dinah; Blankenship, J Todd

    2016-03-01

    One of the most fundamental changes in cell morphology is the ingression of a plasma membrane furrow. The Drosophila embryo undergoes several cycles of rapid furrow ingression during early development that culminate in the formation of an epithelial sheet. Previous studies have demonstrated the requirement for intracellular trafficking pathways in furrow ingression; however, the pathways that link compartmental behaviors with cortical furrow ingression events are unclear. Here, we show that Rab8 has striking dynamic behaviors in vivo. As furrows ingress, cytoplasmic Rab8 puncta are depleted and Rab8 accumulates at the plasma membrane in a location that coincides with known regions of directed membrane addition. We additionally use CRISPR/Cas9 technology to N-terminally tag Rab8, which is then used to address endogenous localization and function. Endogenous Rab8 displays partial coincidence with Rab11 and the Golgi, and this colocalization is enriched during the fast phase of cellularization. When Rab8 function is disrupted, furrow formation in the early embryo is completely abolished. We also demonstrate that Rab8 behaviors require the function of the exocyst complex subunit Sec5 as well as the recycling endosome protein Rab11. Active, GTP-locked Rab8 is primarily associated with dynamic membrane compartments and the plasma membrane, whereas GDP-locked Rab8 forms large cytoplasmic aggregates. These studies suggest a model in which active Rab8 populations direct furrow ingression by guiding the targeted delivery of cytoplasmic membrane stores to the cell surface through interactions with the exocyst tethering complex.

  1. Sensing for directed energy deposition and powder bed fusion additive manufacturing at Penn State University

    NASA Astrophysics Data System (ADS)

    Nassar, Abdalla R.; Reutzel, Edward W.; Brown, Stephen W.; Morgan, John P.; Morgan, Jacob P.; Natale, Donald J.; Tutwiler, Rick L.; Feck, David P.; Banks, Jeffery C.

    2016-04-01

    Additive manufacturing of metal components through directed energy deposition or powder bed fusion is a complex undertaking, often involving hundreds or thousands of individual laser deposits. During processing, conditions may fluctuate, e.g. material feed rate, beam power, surrounding gas composition, local and global temperature, build geometry, etc., leading to unintended variations in final part geometry, microstructure and properties. To assess or control as-deposited quality, researchers have used a variety of methods, including those based on sensing of melt pool and plume emission characteristics, characteristics of powder application, and layer-wise imaging. Here, a summary of ongoing process monitoring activities at Penn State is provided, along with a discussion of recent advancements in the area of layer-wise image acquisition and analysis during powder bed fusion processing. Specifically, methods that enable direct comparisons of CAD model, build images, and 3D micro-tomographic scan data will be covered, along with thoughts on how such analyses can be related to overall process quality.

  2. Anomalous yield reduction in direct-drive DT implosions due to 3He addition

    SciTech Connect

    Herrmann, Hans W; Langenbrunner, James R; Mack, Joseph M; Cooley, James H; Wilson, Douglas C; Evans, Scott C; Sedillo, Tom J; Kyrala, George A; Caldwell, Stephen E; Young, Carlton A; Nobile, Arthur; Wermer, Joseph R; Paglieri, Stephen N; Mcevoy, Aaron M; Kim, Yong Ho; Batha, Steven H; Horsfield, Colin J; Drew, Dave; Garbett, Warren; Rubery, Michael; Glebov, Vladimir Yu; Roberts, Samuel; Frenje, Johan A

    2008-01-01

    Glass capsules were imploded in direct drive on the OMEGA laser [T. R. Boehly et aI., Opt. Commun. 133, 495, 1997] to look for anomalous degradation in deuterium/tritium (DT) yield (i.e., beyond what is predicted) and changes in reaction history with {sup 3}He addition. Such anomalies have previously been reported for D/{sup 3}He plasmas, but had not yet been investigated for DT/{sup 3}He. Anomalies such as these provide fertile ground for furthering our physics understanding of ICF implosions and capsule performance. A relatively short laser pulse (600 ps) was used to provide some degree of temporal separation between shock and compression yield components for analysis. Anomalous degradation in the compression component of yield was observed, consistent with the 'factor of two' degradation previously reported by MIT at a 50% {sup 3}He atom fraction in D{sub 2} using plastic capsules [Rygg et aI., Phys. Plasmas 13, 052702 (2006)]. However, clean calculations (i.e., no fuel-shell mixing) predict the shock component of yield quite well, contrary to the result reported by MIT, but consistent with LANL results in D{sub 2}/{sup 3}He [Wilson, et aI., lml Phys: Conf Series 112, 022015 (2008)]. X-ray imaging suggests less-than-predicted compression ofcapsules containing {sup 3}He. Leading candidate explanations are poorly understood Equation-of-State (EOS) for gas mixtures, and unanticipated particle pressure variation with increasing {sup 3}He addition.

  3. Direct state tomography using continuous variable measuring device

    NASA Astrophysics Data System (ADS)

    Zhu, Xuanmin; Wei, Qun

    2017-01-01

    Compared with the conventional quantum state tomography (QST), the efficiency of the direct state tomography (DST) using weak value is very low. However, DST is easily manipulated in experiments. We modify the direct state tomography by using coupling-deformed observables. The modified direct state measurement is valid for arbitrarily large measurement strength. The optimal measurement strengths are obtained to attain the highest efficiency. The efficiency of DST is significantly improved in the modified strategy, and the reconstructed state has no inherent bias. The state reconstruction strategy investigated in this paper might be useful in actual experiments.

  4. Addition of direct peritoneal lavage to human cadaver organ donor resuscitation improves organ procurement.

    PubMed

    Smith, Jason W; Matheson, Paul J; Morgan, Gary; Matheson, Amy; Downard, Cynthia; Franklin, Glen A; Garrison, R Neal

    2015-04-01

    Brain dead organ donors have altered central hemodynamic performance, impaired hormone physiology, exaggerated systemic inflammatory response, end-organ microcirculatory dysfunction, and tissue hypoxia. A new treatment, direct peritoneal resuscitation (DPR), stabilizes vital organ blood flow after conventionally resuscitated shock to improve these derangements. A prospective case-control study of adjunctive DPR compared 26 experimental patients (brain dead organ donors) to 52 controls (protocolized conventionally resuscitated donors). Actual organ procurement rates were compared with the Scientific Registry of Transplant Recipient predicted organ yield per patient. Achievement of donor management goals and effective hepatic blood flow were recorded. Fourteen of 26 (53.8%) patients treated with DPR achieved all donor management goals compared with 17 of 52 (32.7%) patients treated with conventionally resuscitated (odds ratio = 2.4; 95% CI, 0.92-6.3; p = 0.06). Patients treated with DPR were more than 2 times as likely to achieve final pO2 >100 on 40% FiO2 compared with controls (odds ratio = 2.8; 95% CI, 1-7.69; p = 0.03). Also, DPR-treated patients required less IV crystalloid during the first 12 hours of management (DPR: 3,167 ± 1,893 mL vs 4,154 ± 2,100 mL; p = 0.046) and required less vasopressor agents at 12 hours post resuscitation (odds ratio = 7.7; 95% CI, 0.82-42; p = 0.02). Direct peritoneal resuscitation patients had enhanced effective hepatic blood flow and significantly higher organs transplanted per donor rates compared with controls (3.7 ± 1.7 vs 3.1 ± 1.3; p = 0.024). Direct peritoneal resuscitation reduced IV fluid requirement and IV pressor use as well as increased hepatic blood flow and organs transplanted per donor. Direct peritoneal resuscitation studies show it to be a safe, effective method to augment organ donor resuscitation and additional large-scale trials should be conducted to validate these findings. Copyright © 2015 American

  5. Apparatus for providing directional permeability measurements in subterranean earth formations

    DOEpatents

    Shuck, Lowell Z.

    1977-01-01

    Directional permeability measurements are provided in a subterranean earth formation by injecting a high-pressure gas from a wellbore into the earth formation in various azimuthal directions with the direction having the largest pressure drop being indicative of the maximum permeability direction. These measurements are provided by employing an inflatable boot containing a plurality of conduits in registry with a like plurality of apertures penetrating the housing at circumferentially spaced-apart locations. These conduits are, in turn, coupled through a valved manifold to a source of pressurized gas so that the high-pressure gas may be selectively directed through any conduit into the earth formation defining the bore with the resulting difference in the pressure drop through the various conduits providing the permeability measurements.

  6. Directional radiance measurements: Challenges in the sampling of landscapes

    NASA Technical Reports Server (NTRS)

    Deering, D. W.

    1994-01-01

    Most earth surfaces, particularly those supporting natural vegetation ecosystems, constitute structurally and spectrally complex surfaces that are distinctly non-Lambertian reflectors. Obtaining meaningful measurements of the directional radiances of landscapes and obtaining estimates of the complete bidirectional reflectance distribution functions of ground targets with complex and variable landscape and radiometric features are challenging tasks. Reasons for the increased interest in directional radiance measurements are presented, and the issues that must be addressed when trying to acquire directional radiances for vegetated land surfaces from different types of remote sensing platforms are discussed. Priority research emphases are suggested, concerning field measurements of directional surface radiances and reflectances for future research. Primarily, emphasis must be given to the acquisition of more complete and directly associated radiometric and biometric parameter data sets that will empower the exploitation of the 'angular dimension' in remote sensing of vegetation through enabling the further development and rigorous validation of state of the art plant canopy models.

  7. Dynamometer for measuring machining forces in two perpendicular directions

    NASA Technical Reports Server (NTRS)

    Sutherland, I. A.

    1974-01-01

    Published report discusses development of two-component force dynamometer which is used for dynamic measurement of machining forces in cutting and thrust directions. Resulting data suggest that faster metal-cutting machines may be developed that have reduced vibrations.

  8. The Measurement of the Directional Hemispherical Reflectance From Spectralon

    NASA Technical Reports Server (NTRS)

    Haner, D. A.; McGuckin, B. T.; Menzies, R. T.; Bruegge, C. J.; Duval, V.

    1997-01-01

    The directional hemispheric reflecatance is measured for Spectralon, the material chosen for on-board radiometric calibration of the Multiangle Imaging SpectroRadiometer (MISR), at laser wavelengths of 442, 632.8 and 859.9nm.

  9. Direct measurements of pore fluid density by vibrating tube densimetry.

    PubMed

    Gruszkiewicz, Miroslaw S; Rother, Gernot; Wesolowski, David J; Cole, David R; Wallacher, Dirk

    2012-03-20

    The densities of pore-confined fluids were measured for the first time by means of vibrating tube densimetry (VTD). A custom-built high-pressure, high-temperature vibrating tube densimeter was used to measure the densities of propane at subcritical and supercritical temperatures (between 35 and 97 °C) and carbon dioxide at supercritical temperatures (between 32 and 50 °C) saturating hydrophobic silica aerogel (0.2 g/cm(3), 90% porosity) synthesized inside Hastelloy U-tubes. Additionally, supercritical isotherms of excess adsorption for CO(2) and the same porous solid were measured gravimetrically using a precise magnetically coupled microbalance. Pore fluid densities and total adsorption isotherms increased monotonically with increasing density of the bulk fluid, in contrast to excess adsorption isotherms, which reached a maximum and then decreased toward zero or negative values above the critical density of the bulk fluid. The isotherms of confined fluid density and excess adsorption obtained by VTD contain additional information. For instance, the maxima of excess adsorption occur below the critical density of the bulk fluid at the beginning of the plateau region in the total adsorption, marking the end of the transition of pore fluid to a denser, liquidlike pore phase. Compression of the confined fluid significantly beyond the density of the bulk fluid at the same temperature was observed even at subcritical temperatures. The effect of pore confinement on the liquid-vapor critical temperature of propane was less than ~1.7 K. The results for propane and carbon dioxide showed similarity in the sense of the principle of corresponding states. Good quantitative agreement was obtained between excess adsorption isotherms determined from VTD total adsorption results and those measured gravimetrically at the same temperature, confirming the validity of the vibrating tube measurements. Thus, it is demonstrated that vibrating tube densimetry is a novel experimental

  10. Direct force-measuring transducer used in blood pressure research

    NASA Technical Reports Server (NTRS)

    Eige, J. J.; Newgard, P. M.; Pressman, G. L.

    1965-01-01

    Direct force measuring transducer acts as an arterial tonometer, gives a direct readout to instrumentation, and is unaffected by ambient noise. It uses a semiconductor strain gage which is deflected by pressure pulses in the artery. The deflection changes the resistance of the gage and alters the voltage reading on the associated instrumentation.

  11. Direct Measurements of Pore Fluid Density by Vibrating Tube Densimetry

    SciTech Connect

    Gruszkiewicz, Miroslaw {Mirek} S; Rother, Gernot; Wesolowski, David J; Cole, David R; Wallacher, Dirk

    2012-01-01

    The densities of pore-confined fluids were measured for the first time by means of a vibrating tube method. Isotherms of total adsorption capacity were measured directly making the method complementary to the conventional gravimetric or volumetric/piezometric adsorption techniques, which yield the excess adsorption (the Gibbsian surface excess). A custom-made high-pressure, high-temperature vibrating tube densimeter (VTD) was used to measure the densities of subcritical and supercritical propane (between 35 C and 97 C) and supercritical carbon dioxide (between 32 C and 50 C) saturating hydrophobic silica aerogel (0.2 g/cm3, 90% porosity) synthesized inside Hastelloy U-tubes. Additionally, excess adsorption isotherms for supercritical CO2 and the same porous solid were measured gravimetrically using a precise magnetically-coupled microbalance. Pore fluid densities and total adsorption isotherms increased monotonically with increasing density of the bulk fluid, in contrast to excess adsorption isotherms, which reached a maximum at a subcritical density of the bulk fluid, and then decreased towards zero or negative values at supercritical densities. Compression of the confined fluid significantly beyond the density of the bulk liquid at the same temperature was observed at subcritical temperatures. The features of the isotherms of confined fluid density are interpreted to elucidate the observed behavior of excess adsorption. The maxima of excess adsorption were found to occur below the critical density of the bulk fluid at the conditions corresponding to the beginning of the plateau of total adsorption, marking the end of the transition of pore fluid to a denser, liquid-like pore phase. The results for propane and carbon dioxide showed similarity in the sense of the principle of corresponding states. No measurable effect of pore confinement on the liquid-vapor critical point was found. Quantitative agreement was obtained between excess adsorption isotherms determined

  12. Image analysis software versus direct anthropometry for breast measurements.

    PubMed

    Quieregatto, Paulo Rogério; Hochman, Bernardo; Furtado, Fabianne; Machado, Aline Fernanda Perez; Sabino Neto, Miguel; Ferreira, Lydia Masako

    2014-10-01

    To compare breast measurements performed using the software packages ImageTool(r), AutoCAD(r) and Adobe Photoshop(r) with direct anthropometric measurements. Points were marked on the breasts and arms of 40 volunteer women aged between 18 and 60 years. When connecting the points, seven linear segments and one angular measurement on each half of the body, and one medial segment common to both body halves were defined. The volunteers were photographed in a standardized manner. Photogrammetric measurements were performed by three independent observers using the three software packages and compared to direct anthropometric measurements made with calipers and a protractor. Measurements obtained with AutoCAD(r) were the most reproducible and those made with ImageTool(r) were the most similar to direct anthropometry, while measurements with Adobe Photoshop(r) showed the largest differences. Except for angular measurements, significant differences were found between measurements of line segments made using the three software packages and those obtained by direct anthropometry. AutoCAD(r) provided the highest precision and intermediate accuracy; ImageTool(r) had the highest accuracy and lowest precision; and Adobe Photoshop(r) showed intermediate precision and the worst accuracy among the three software packages.

  13. Use of fused deposit modeling for additive manufacturing in hospital facilities: European certification directives.

    PubMed

    Otero, Joel J; Vijverman, An; Mommaerts, Maurice Y

    2017-09-01

    The goal of this study was to identify current European Union regulations governing hospital-based use of fused deposit modeling (FDM), as implemented via desktop three-dimensional (3D) printers. Literature and Internet sources were screened, searching for official documents, regulations/legislation, and views of specialized attorneys or consultants regarding European regulations for 3D printing or additive manufacturing (AM) in a healthcare facility. A detailed review of the latest amendment (2016) of the European Parliament and Council legislation for medical devices and its classification was performed, which has regularly updated published guidelines for medical devices, that are classified by type and duration of patient contact. As expected, regulations increase in accordance with the level (I-III) of classification. Custom-made medical devices are subject to different regulations than those controlling serially mass-produced items, as originally specified in 98/79/EC European Parliament and Council legislation (1993) and again recently amended (2016). Healthcare facilities undertaking in-house custom production are not obliged to fully follow the directives as stipulated, given an exception for this scenario (Article 4.4a, 98/79/EC). Patient treatment and diagnosis with the aid of customized 3D printing in a healthcare facility can be performed without fully meeting the European Parliament and Council legislation if the materials used are ISO 10993 certified and article 4.4a applies. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  14. Multiscale 3D manufacturing: combining thermal extrusion printing with additive and subtractive direct laser writing

    NASA Astrophysics Data System (ADS)

    Malinauskas, Mangirdas; Lukoševičius, Laurynas; MackevičiÅ«tÄ--, DovilÄ--; BalčiÅ«nas, Evaldas; RekštytÄ--, Sima; Paipulas, Domas

    2014-05-01

    A novel approach for efficient manufacturing of three-dimensional (3D) microstructured scaffolds designed for cell studies and tissue engineering applications is presented. A thermal extrusion (fused filament fabrication) 3D printer is employed as a simple and low-cost tabletop device enabling rapid materialization of CAD models out of biocompatible and biodegradable polylactic acid (PLA). Here it was used to produce cm- scale microporous (pore size varying from 100 to 400 µm) scaffolds. The fabricated objects were further laser processed in a direct laser writing (DLW) subtractive (ablation) and additive (lithography) manners. The first approach enables precise surface modification by creating micro-craters, holes and grooves thus increasing the surface roughness. An alternative way is to immerse the 3D PLA scaffold in a monomer solution and use the same DLW setup to refine its inner structure by fabricating dots, lines or a fine mesh on top as well as inside the pores of previously produced scaffolds. The DLW technique is empowered by ultrafast lasers - it allows 3D structuring with high spatial resolution in a great variety of photosensitive materials. Structure geometry on macro- to micro- scales could be finely tuned by combining these two fabrication techniques. Such artificial 3D substrates could be used for cell growth or as biocompatible-biodegradable implants. This combination of distinct material processing techniques enables rapid fabrication of diverse functional micro- featured and integrated devices. Hopefully, the proposed approach will find numerous applications in the field of ms, microfluidics, microoptics and many others.

  15. Influence of "omnidirectional" loudspeaker directivity on measured room impulse responses.

    PubMed

    Knüttel, Tobias; Witew, Ingo B; Vorländer, Michael

    2013-11-01

    Measured room impulse responses (RIR) strongly depend on the directivity of the sound source used for the measurement. An analysis method is presented that is capable of pinpointing the influence of the loudspeaker's directivity on a set of RIRs. Taking into account the rotational symmetries of a dodecahedron loudspeaker, it detects the effects that the changing directional pattern induces in the RIR. The analysis of RIRs measured in completely different acoustical environments reveals that the influence of the loudspeaker's directivity can still be observed in the very late part of the RIR-even in very reverberant rooms. These results are presented and the consistency with general room acoustical theory is revised and discussed.

  16. Direct measurements of beta-star in the Tevatron

    SciTech Connect

    Syphers, M.J.; Miyamoto, R.; /Texas U.

    2007-06-01

    Simultaneous turn-by-turn beam position measurements across collider detector long straight sections provide full phase space information of a free oscillation. For signals with enough coherence (typically 1-2000 revolutions) the amplitude function and its slope at the two BPM's can be directly measured. Results for the Tevatron low-{beta} regions with a few percent accuracy are described.

  17. Estimating Radar Velocity using Direction of Arrival Measurements

    SciTech Connect

    Doerry, Armin Walter; Horndt, Volker; Bickel, Douglas Lloyd; Naething, Richard M.

    2014-09-01

    Direction of Arrival (DOA) measurements, as with a monopulse antenna, can be compared against Doppler measurements in a Synthetic Aperture Radar ( SAR ) image to determine an aircraft's forward velocity as well as its crab angle, to assist the aircraft's navigation as well as improving high - performance SAR image formation and spatial calibration.

  18. New Directions in Measuring Racial Isolation in School

    ERIC Educational Resources Information Center

    Conger, Dylan

    2010-01-01

    This article offers new directions in measuring racial isolation in schools. The most widely used measurement approach is to examine the mean on the distribution of school percentage non-White across non-White students (the isolation rate) or the percentage of non-White students in schools with large shares of non-Whites (e.g., 90% or more) at a…

  19. Measurement of directivity index by three-dimensional spatial sampling

    NASA Astrophysics Data System (ADS)

    Julstrom, Stephen D.

    2005-09-01

    The traditional method for finding the directivity index (DI) of a microphone by extrapolation from its two-dimensional polar pattern may not be accurate when the microphone or its mounting surface is acoustically large. In situ hearing aid microphone DI determination requires knowledge of the full three-dimensional directional response. Microphone DI may be measured directly by comparison of the on-axis anechoic sensitivity to the sensitivity in a diffuse sound field, normalizing the comparison by reference to a perfect omnidirectional microphone. In practice, creating an accurately diffuse field is difficult, and is traditionally accomplished by averaging measurements taken at several locations in a reverberant room excited by multiple uncorrelated sound sources. Theoretically equivalent results can be obtained by three-dimensional spatial sampling in an anechoic environment, inferring the full spherical response from a finite number of directional measurements. The necessary density, positioning, and positioning accuracy of measurement directions is determined by sampling theory, tests employing mathematically defined polar patterns, and practical considerations, leading to a minimum specification of 48 measurement points arranged in five horizontal zones. Non-uniform spacing of these points necessitates employing a weighted average of the sensitivity measurements to obtain the best prediction of the actual diffuse field response.

  20. Direct-coupling information measure from nonuniform embedding

    NASA Astrophysics Data System (ADS)

    Kugiumtzis, D.

    2013-06-01

    A measure to estimate the direct and directional coupling in multivariate time series is proposed. The measure is an extension of a recently published measure of conditional mutual information from mixed embedding (MIME) for bivariate time series. In the proposed measure of partial MIME (PMIME), the embedding is on all observed variables and it is optimized in explaining the response variable. It is shown that PMIME detects correctly direct coupling and outperforms the (linear) conditional Granger causality and the partial transfer entropy. We demonstrate that PMIME does not rely on significance test and embedding parameters and the number of observed variables has no effect on its statistical accuracy; it may only slow the computations. The importance of these points is shown in simulations and in an application to epileptic multichannel scalp electroencephalograms.

  1. Direct-coupling information measure from nonuniform embedding.

    PubMed

    Kugiumtzis, D

    2013-06-01

    A measure to estimate the direct and directional coupling in multivariate time series is proposed. The measure is an extension of a recently published measure of conditional mutual information from mixed embedding (MIME) for bivariate time series. In the proposed measure of partial MIME (PMIME), the embedding is on all observed variables and it is optimized in explaining the response variable. It is shown that PMIME detects correctly direct coupling and outperforms the (linear) conditional Granger causality and the partial transfer entropy. We demonstrate that PMIME does not rely on significance test and embedding parameters and the number of observed variables has no effect on its statistical accuracy; it may only slow the computations. The importance of these points is shown in simulations and in an application to epileptic multichannel scalp electroencephalograms.

  2. Ion Mobility-Derived Collision Cross Section As an Additional Measure for Lipid Fingerprinting and Identification

    PubMed Central

    2014-01-01

    Despite recent advances in analytical and computational chemistry, lipid identification remains a significant challenge in lipidomics. Ion-mobility spectrometry provides an accurate measure of the molecules’ rotationally averaged collision cross-section (CCS) in the gas phase and is thus related to ionic shape. Here, we investigate the use of CCS as a highly specific molecular descriptor for identifying lipids in biological samples. Using traveling wave ion mobility mass spectrometry (MS), we measured the CCS values of over 200 lipids within multiple chemical classes. CCS values derived from ion mobility were not affected by instrument settings or chromatographic conditions, and they were highly reproducible on instruments located in independent laboratories (interlaboratory RSD < 3% for 98% of molecules). CCS values were used as additional molecular descriptors to identify brain lipids using a variety of traditional lipidomic approaches. The addition of CCS improved the reproducibility of analysis in a liquid chromatography-MS workflow and maximized the separation of isobaric species and the signal-to-noise ratio in direct-MS analyses (e.g., “shotgun” lipidomics and MS imaging). These results indicate that adding CCS to databases and lipidomics workflows increases the specificity and selectivity of analysis, thus improving the confidence in lipid identification compared to traditional analytical approaches. The CCS/accurate-mass database described here is made publicly available. PMID:25495617

  3. Standardization of serum cholesterol assays by use of serum calibrators and direct addition of Liebermann-Burchard reagent.

    PubMed

    Katan, M B; van der Haar, F; Kromhout, D; Schouten, F J

    1982-04-01

    Serum cholesterol concentrations of subjects in epidemiological studies were measured after direct addition of Liebermann-Burchard reagent; results were calibrated with human serum pools assayed according to Abell et al. (J. Biol. Chem. 195:357-366, 1952). Accuracy and precision were monitored for six years by analysis of internal-control pools and blind external-control pools. For various internal-control pools, the imprecision (CV) of the long-term averages of run means ranged from 0.5 to 0.9%. The within-run CV for internal control and patients' sera was about 1%. For blind control sera with different concentrations (provided by the Centers for Disease Control, Atlanta, GA, over the same period), the average difference per three-month period between the values found and the target values was usually between -0.5% and +0.7% for medium-concentration pools and between -2% and +2% for low- and high-concentration pools (extreme values: -2.4% and +2.5%). The CV per three-month period ranged from 0.6 to 2.7%. Sera from subjects on diets of high or low linoleic acid content were analyzed to study the effect of the fatty acid portion of serum cholesterol esters; the differences between values obtained with the comparison method and the direct method was insignificant on both diets. We conclude that the use of serum calibrators eliminates the bias inherent in the direct method.

  4. Computer simulation of three-dimensional directional response measurements

    NASA Astrophysics Data System (ADS)

    Warren, Daniel M.

    2005-09-01

    Early in the development of methods for measuring the three-dimensional directional response of hearing aids, there were many questions on how to distribute sound sources over the sphere. The method had to be accurate, yet practical to implement. Decisions on the scheme for distributing sound sources, the density of sound sources, and the weighting of results from each source have impact on accuracy. A simulation of the directional response of an array of microphones in the direct and scattered acoustic field near a rigid sphere was created and used to evaluate various means of distributing sound sources.

  5. Josephson directional amplifier for quantum measurement of superconducting circuits.

    PubMed

    Abdo, Baleegh; Sliwa, Katrina; Shankar, S; Hatridge, Michael; Frunzio, Luigi; Schoelkopf, Robert; Devoret, Michel

    2014-04-25

    We realize a microwave quantum-limited amplifier that is directional and can therefore function without the front circulator needed in many quantum measurements. The amplification takes place in only one direction between the input and output ports. Directionality is achieved by multipump parametric amplification combined with wave interference. We have verified the device noise performances by using it to read out a superconducting qubit and observed quantum jumps. With an improved version of this device, the qubit and preamplifer could be integrated on the same chip.

  6. 30 CFR 250.1925 - May BSEE direct me to conduct additional audits?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... may direct you to have an ASP audit of your SEMS program if BSEE identifies safety or non-compliance... an audit. (1) If BSEE directs you to have an ASP audit, you are responsible for all of the costs associated with the audit, and (i) The ASP must meet the requirements of §§ 250.1920 and 250.1921 of...

  7. Item-Specific Encoding Produces an Additional Benefit of Directed Forgetting: Evidence from Intrusion Errors

    ERIC Educational Resources Information Center

    Sahakyan, Lili; Delaney, Peter F.

    2010-01-01

    List-method directed forgetting involves encoding 2 lists, between which half of the participants are told to forget List 1. When participants are free to study however they want, directed forgetting impairs List 1 recall and enhances List 2 recall in the forget group compared with a control remember group. In a large-scale experiment, the current…

  8. Goal-directed and transfer-cue-elicited drug-seeking are dissociated by pharmacotherapy: evidence for independent additive controllers.

    PubMed

    Hogarth, Lee

    2012-07-01

    According to contemporary learning theory, drug-seeking behavior reflects the summation of 2 dissociable controllers. Whereas goal-directed drug-seeking is determined by the expected current incentive value of the drug, stimulus-elicited drug-seeking is determined by the expected probability of the drug independently of its current incentive value, and these 2 controllers contribute additively to observed drug-seeking. One applied prediction of this model is that smoking cessation pharmacotherapies selectively attenuate tonic but not cue-elicited craving because they downgrade the expected incentive value of the drug but leave expected probability intact. To test this, the current study examined whether nicotine replacement therapy (NRT) nasal spray would modify goal-directed tobacco choice in a human outcome devaluation procedure, but leave cue-elicited tobacco choice in a Pavlovian to instrumental transfer (PIT) procedure intact. Smokers (N= 96) first underwent concurrent choice training in which 2 responses earned tobacco or chocolate points, respectively. Participants then ingested either NRT nasal spray (1 mg) or chocolate (147 g) to devalue 1 outcome. Concurrent choice was then tested again in extinction to measure goal-directed control of choice, and in a PIT test to measure the extent to which tobacco and chocolate stimuli enhanced choice of the same outcome. It was found that NRT modified tobacco choice in the extinction test but not the extent to which the tobacco stimulus enhanced choice of the tobacco outcome in the PIT test. This dissociation suggests that the propensity to engage in drug-seeking is determined independently by the expected value and probability of the drug, and that pharmacotherapy has partial efficacy because it selectively effects expected drug value.

  9. Direct Measurement of Mercury Reactions In Coal Power Plant Plumes

    SciTech Connect

    Leonard Levin

    2005-12-31

    west of Kenosha. Aircraft and ground measurements support the occurrence of a reduction in the fraction of reactive gaseous mercury (RGM) (with a corresponding increase in elemental mercury) as part of the Total Gaseous Mercury (TGM) emitted from the Pleasant Prairie stack. This occurrence is based on comparison of the RGM concentrations in the plume (at standard conditions) compared to the RGM in the stack. There was found to be a 44% drop in the fraction of RGM between the stack exit and the first sampling arc and a 66% reduction from the stack to the 5-mile sampling arc, with no additional drop between the 5- and 10-mile arcs. Smaller-scale experiments in both test chambers and pilot-scale coal combustor exhaust streams have indicated the presence of rapid and relatively complete reduction reactions converting divalent into elemental mercury within power plant plumes prior to full dispersion in the atmosphere. These measurements, however, have been unable to identify whether the reactions occur during plume rise from physical to virtual stack height (during positive thermal buoyancy). The presence, rate, completeness, ubiquity, and dependence on source characteristics of these reactions, however, must be demonstrated in plume environments associated with fully operational power plants. That requirement, to capture either the reactions or the reaction products of chemistry that may be occurring very close to stack exits in highly turbulent environments, constrains the precision and reproducibility with which such full-scale experiments can be carried out. The work described here is one of several initial steps required to test whether, and in what direction, such rapid mercury redox reactions might be occurring in such plumes.

  10. The direct and indirect relationships between alcohol prevention measures and alcoholic liver cirrhosis mortality.

    PubMed

    Xie, X; Mann, R E; Smart, R G

    2000-07-01

    The objective of this article is to investigate direct and indirect relationships between prevention measures and alcoholic liver cirrhosis mortality in Canadian provinces from 1968 to 1986. The data base that was assembled included alcoholic cirrhosis mortality rates, alcohol availability measures (rate of licensed premises, year in which the legal drinking age was reduced), per capita consumption of alcohol, rates of AA members and groups, and economic and demographic measures. This article develops a two-equation analytic model based on the availability theory of alcohol problems and prevention (Single, 1988). The distinction between direct and indirect effects of prevention measures can be made explicitly with this model. Alcohol availability measures, but not AA measures, had a significant direct potential impact on alcohol consumption. AA measures had a significant direct relationship to cirrhosis mortality rates. Alcohol consumption also had a significant direct relationship to cirrhosis mortality, and alcohol availability measures had an important indirect relationship through their influence on per capita alcohol consumption. While these observations need to be interpreted cautiously, the two-equation model shows promise as an approach to understanding direct and indirect influences on alcohol problems. As expected, AA measures and per capita alcohol consumption demonstrated significant direct relationship to cirrhosis mortality. In addition, important indirect influences of drinking-age changes and rates of licensed premises on cirrhosis mortality were observed through their relationships to per capita alcohol consumption.

  11. Photogrammetric Correlation of Face with Frontal Radiographs and Direct Measurements.

    PubMed

    Negi, Gunjan; Ponnada, Swaroopa; Aravind, N K S; Chitra, Prasad

    2017-05-01

    Photogrammetry is a science of making measurements from photographs. As cephalometric analysis till date has focused mainly on skeletal relationships, photogrammetry may provide a means to reliably assess and compare soft tissue and hard tissue measurements. To compare and correlate linear measurements taken directly from subject's faces and from standardized frontal cephalometric radiographs and to correlate them with standardized frontal facial photographs of Indian population and to obtain mean values. A cross-sectional study was conducted on 30 subjects of Indian origin. Frontal cephalograms and standardized frontal photographs were obtained from subjects in the age group of 18- 25 years. Vernier calipers were used to obtain facial measurements directly. Photographs and radiographs were uploaded and measured using Nemoceph software. Analogous cephalometric, photographic and direct measurements were compared by one-way ANOVA to assess Pearson correlation coefficients for 12 linear measurements (6 vertical, 6 horizontal). Bonferroni post-hoc test was done for pair wise comparison. Among all measurements used, OR-OL (orbitale right-orbitale left) showed a high correlation r = 0.76, 0.70, 0.71. There was moderate correlation with EnR-EnL (endocanthion rt - endocanthion lt) r(2) = 0.62, 0.68, 0.68. Highly significant correlation was evident with N-Sn, EnR-EnL and AgR-AgL with p<0.001. A statistically significant correlation was found between photographic, radiographic and direct measurements. Therefore, photogrammetry has proven to be an alternative diagnostic tool that can be used in epidemiologic studies when there is a need for a simple, basic, non-invasive and cost-effective method.

  12. Full Flight Envelope Direct Thrust Measurement on a Supersonic Aircraft

    NASA Technical Reports Server (NTRS)

    Conners, Timothy R.; Sims, Robert L.

    1998-01-01

    Direct thrust measurement using strain gages offers advantages over analytically-based thrust calculation methods. For flight test applications, the direct measurement method typically uses a simpler sensor arrangement and minimal data processing compared to analytical techniques, which normally require costly engine modeling and multisensor arrangements throughout the engine. Conversely, direct thrust measurement has historically produced less than desirable accuracy because of difficulty in mounting and calibrating the strain gages and the inability to account for secondary forces that influence the thrust reading at the engine mounts. Consequently, the strain-gage technique has normally been used for simple engine arrangements and primarily in the subsonic speed range. This paper presents the results of a strain gage-based direct thrust-measurement technique developed by the NASA Dryden Flight Research Center and successfully applied to the full flight envelope of an F-15 aircraft powered by two F100-PW-229 turbofan engines. Measurements have been obtained at quasi-steady-state operating conditions at maximum non-augmented and maximum augmented power throughout the altitude range of the vehicle and to a maximum speed of Mach 2.0 and are compared against results from two analytically-based thrust calculation methods. The strain-gage installation and calibration processes are also described.

  13. Direct measurement of capillary blood pressure in the human lip

    NASA Technical Reports Server (NTRS)

    Parazynski, S. E.; Tucker, B. J.; Aratow, M.; Crenshaw, A.; Hargens, A. R.

    1993-01-01

    In this study, we developed and tested a new procedure for measuring microcirculatory blood pressures above heart level in humans. Capillary and postcapillary venule blood pressures were measured directly in 13 human subjects by use of the servonulling micropressure technique adapted for micropuncture of lip capillaries. Pressure waveforms were recorded in 40 separate capillary vessels and 14 separate postcapillary venules over periods ranging from 5 to 64 s. Localization and determination of capillary and postcapillary vessels were ascertained anatomically before pressure measurements. Capillary pressure was 33.2 +/- 1.5 (SE) mm Hg in lips of subjects seated upright. Repeated micropunctures of the same vessel gave an average coefficient of variation of 0.072. Postcapillary venule pressure was 18.9 +/- 1.6 mm Hg. This procedure produces a direct and reproducible means of measuring microvascular blood pressures in a vascular bed above heart level in humans.

  14. Direct measurement of capillary blood pressure in the human lip

    NASA Technical Reports Server (NTRS)

    Parazynski, S. E.; Tucker, B. J.; Aratow, M.; Crenshaw, A.; Hargens, A. R.

    1993-01-01

    In this study, we developed and tested a new procedure for measuring microcirculatory blood pressures above heart level in humans. Capillary and postcapillary venule blood pressures were measured directly in 13 human subjects by use of the servonulling micropressure technique adapted for micropuncture of lip capillaries. Pressure waveforms were recorded in 40 separate capillary vessels and 14 separate postcapillary venules over periods ranging from 5 to 64 s. Localization and determination of capillary and postcapillary vessels were ascertained anatomically before pressure measurements. Capillary pressure was 33.2 +/- 1.5 (SE) mm Hg in lips of subjects seated upright. Repeated micropunctures of the same vessel gave an average coefficient of variation of 0.072. Postcapillary venule pressure was 18.9 +/- 1.6 mm Hg. This procedure produces a direct and reproducible means of measuring microvascular blood pressures in a vascular bed above heart level in humans.

  15. Direct measurement of lower atmospheric vertical potential differences

    NASA Astrophysics Data System (ADS)

    Holzworth, R. H.; Dazey, M. H.; Schnauss, E. R.; Youngbluth, O.

    1981-07-01

    A high impedance system has been developed to make direct measurements of the atmospheric potential difference up to several thousand feet. A tethered balloon flown from Wallops Island, Virginia was used to loft a high voltage, insulated wire and a conducting collector in a test flight to 550 meters for two days of experiments in October 1980. The balloon was equipped with a payload to measure exact altitude, wind speed and direction, and other meteorological parameters. Electric potentials of 170,000 volts at 550 meters were measured. The collected currents which could be drawn through the wire by grounding the lower end were in the 10 microamp range indicating a system impedance of about 1010 ohms. This paper will describe the apparatus and details of these measurements.

  16. Direct measurements of the convective recycling of the upper troposphere.

    PubMed

    Bertram, Timothy H; Perring, Anne E; Wooldridge, Paul J; Crounse, John D; Kwan, Alan J; Wennberg, Paul O; Scheuer, Eric; Dibb, Jack; Avery, Melody; Sachse, Glen; Vay, Stephanie A; Crawford, James H; McNaughton, Cameron S; Clarke, Antony; Pickering, Kenneth E; Fuelberg, Henry; Huey, Greg; Blake, Donald R; Singh, Hanwant B; Hall, Samuel R; Shetter, Richard E; Fried, Alan; Heikes, Brian G; Cohen, Ronald C

    2007-02-09

    We present a statistical representation of the aggregate effects of deep convection on the chemistry and dynamics of the upper troposphere (UT) based on direct aircraft observations of the chemical composition of the UT over the eastern United States and Canada during summer. These measurements provide unique observational constraints on the chemistry occurring downwind of convection and the rate at which air in the UT is recycled. These results provide quantitative measures that can be used to evaluate global climate and chemistry models.

  17. MHC class IIB additive and non-additive effects on fitness measures in the guppy Poecilia reticulata.

    PubMed

    Fraser, B A; Neff, B D

    2009-12-01

    The genetic architecture of fitness at the class IIB gene of the major histocompatibility complex (MHC) in the guppy Poecilia reticulata was analysed. Diversity at the MHC is thought to be maintained by some form of balancing selection; heterozygote advantage, frequency-dependent selection or spatially and temporally fluctuating selection. Here these hypotheses are evaluated by using an algorithm that partitions the effect of specific MHC allele and genotypes on fitness measures. The effect of MHC genotype on surrogate measures of fitness was tested, including growth rate (at high and low bulk food diets), parasite load following a parasite challenge and survival. The number of copies of the Pore_a132 MHC allele was inversely related to infection by Gyrodactylus flukes and it appeared to be positively related to faster growth. Also, genotypes combining the Pore_a132 or other relatively common alleles paired with rare MHC alleles produced both advantageous and detrimental non-additive effects. Thus, the genetic architecture underlying fitness at the MHC is complex in the P. reticulata.

  18. Prospects for cost reductions from relaxing additional cross-border measures related to livestock trade.

    PubMed

    Hop, G E; Mourits, M C M; Slager, R; Oude Lansink, A G J M; Saatkamp, H W

    2013-05-01

    Compared with the domestic trade in livestock, intra-communal trade across the European Union (EU) is subject to costly, additional veterinary measures. Short-distance transportation just across a border requires more measures than long-distance domestic transportation, while the need for such additional cross-border measures can be questioned. This study examined the prospects for cost reductions from relaxing additional cross-border measures related to trade within the cross-border region of the Netherlands (NL) and Germany (GER); that is, North Rhine Westphalia and Lower Saxony. The study constructed a deterministic spread-sheet cost model to calculate the costs of both routine veterinary measures (standard measures that apply to both domestic and cross-border transport) and additional cross-border measures (extra measures that only apply to cross-border transport) as applied in 2010. This model determined costs by stakeholder, region and livestock sector, and studied the prospects for cost reduction by calculating the costs after the relaxation of additional cross-border measures. The selection criteria for relaxing these measures were (1) a low expected added value on preventing contagious livestock diseases, (2) no expected additional veterinary risks in case of relaxation of measures and (3) reasonable cost-saving possibilities. The total cost of routine veterinary measures and additional cross-border measures for the cross-border region was €22.1 million, 58% (€12.7 million) of which came from additional cross-border measures. Two-thirds of this €12.7 million resulted from the trade in slaughter animals. The main cost items were veterinary checks on animals (twice in the case of slaughter animals), export certification and control of export documentation. Four additional cross-border measures met the selection criteria for relaxation. The relaxation of these measures could save €8.2 million (€5.0 million for NL and €3.2 million for GER) annually

  19. 30 CFR 250.1925 - May BSEE direct me to conduct additional audits?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Safety and... an audit. (1) If BSEE directs you to have an ASP audit, you are responsible for all of the costs...

  20. Calibration of Laser Beam Direction for Inner Diameter Measuring Device.

    PubMed

    Yang, Tongyu; Wang, Zhong; Wu, Zhengang; Li, Xingqiang; Wang, Lei; Liu, Changjie

    2017-02-05

    The laser triangulation method is one of the most advanced methods for large inner diameter measurement. Our research group proposed a kind of inner diameter measuring device that is principally composed of three laser displacement sensors known to be fixed in the same plane measurement position. It is necessary to calibrate the direction of the laser beams that are emitted by laser displacement sensors because they do not meet the theoretical model accurately. For the purpose of calibrating the direction of laser beams, a calibration method and mathematical model were proposed. The inner diameter measuring device is equipped with the spindle of the machine tool. The laser beams rotate and translate in the plane and constitute the rotary rays which are driven to scan the inner surface of the ring gauge. The direction calibration of the laser beams can be completed by the sensors' distance information and corresponding data processing method. The corresponding error sources are analyzed and the validity of the method is verified. After the calibration, the measurement error of the inner diameter measuring device reduced from ± 25 μ m to ± 15 μ m and the relative error was not more than 0.011%.

  1. Calibration of Laser Beam Direction for Inner Diameter Measuring Device

    PubMed Central

    Yang, Tongyu; Wang, Zhong; Wu, Zhengang; Li, Xingqiang; Wang, Lei; Liu, Changjie

    2017-01-01

    The laser triangulation method is one of the most advanced methods for large inner diameter measurement. Our research group proposed a kind of inner diameter measuring device that is principally composed of three laser displacement sensors known to be fixed in the same plane measurement position. It is necessary to calibrate the direction of the laser beams that are emitted by laser displacement sensors because they do not meet the theoretical model accurately. For the purpose of calibrating the direction of laser beams, a calibration method and mathematical model were proposed. The inner diameter measuring device is equipped with the spindle of the machine tool. The laser beams rotate and translate in the plane and constitute the rotary rays which are driven to scan the inner surface of the ring gauge. The direction calibration of the laser beams can be completed by the sensors’ distance information and corresponding data processing method. The corresponding error sources are analyzed and the validity of the method is verified. After the calibration, the measurement error of the inner diameter measuring device reduced from ±25 μm to ±15 μm and the relative error was not more than 0.011%. PMID:28165432

  2. A direct anatomical study of additional renal arteries in a Colombian mestizo population.

    PubMed

    Saldarriaga, B; Pérez, A F; Ballesteros, L E

    2008-05-01

    Traditional anatomy describes each kidney as receiving irrigation from a single renal artery. However, current literature reports great variability in renal blood supply, the number of renal arteries mentioned being the most frequently found variation. Such variation has great implications when surgery is indicated, such as in renal transplants, uroradiological procedures, renovascular hypertension, renal trauma and hydronephrosis. This article pretends to determine the frequency of additional renal arteries and their morphological expression in Colombian population in a cross-sectional study. A total of 196 of renal blocks were analysed from autopsies carried out in the Bucaramanga Institute of Forensic Medicine, Colombia; these renal blocks were processed by the injection- corrosion technique. The average age of the people being studied was 33.8 +/- 15.6 years; 85.4% of them were male and the rest female. An additional renal artery was found in 22.3% of the whole population and two additional ones were found in 2.6% of the same sample. The additional renal artery was most frequently found on the left side. The additional artery arose from the aorta's lateral aspect (52.4%); these additional arteries usually entered the renal parenchyma through the hilum. No difference was established according to gender. Nearly a third of the Colombian population presents one additional renal artery and about 3% of the same population presents two additional renal arteries. Most of them reached the kidney through its hilar region.

  3. Direct measurement of quasiprobability distributions in cavity QED

    SciTech Connect

    Juarez-Amaro, Raul; Moya-Cessa, Hector

    2003-08-01

    We show that the set of s-parametrized quasiprobability distribution functions corresponding to an electromagnetic field in a cavity subject to dissipation can be directly measured. Such distributions contain whole information of the quantum state, therefore making it possible to recover information after losses have occurred.

  4. Direct measurements of radiative capture reactions with DRAGON

    NASA Astrophysics Data System (ADS)

    Christian, Gregory

    2015-10-01

    Direct measurements of radiative proton and alpha capture reactions are crucial for understanding nucleosynthesis in a variety of astrophysical environments, including classical novae, supernovae, X-Ray bursts, and quiescent stellar burning. Often the most important reactions have very low cross sections or involve unstable targets, making laboratory measurements extremely challenging. The detector of recoils and gammas of nuclear reactions (DRAGON) at TRIUMF is a recoil mass separator designed to measure radiative capture reactions in inverse kinematics, with beam suppression factors as high as 1016. When combined with the intense radioactive beams available at the ISAC-I facility, DRAGON's capabilities are unique and world-leading. In this talk, I will give a brief technical overview of DRAGON before presenting results from recent experiments. Some highlights include the first-ever direct measurement of 38K(p , γ) 39Ca, a crucial reaction for determining the endpoint of nova nucleosynthesis, and measurements of 76Se(α , γ) 80Kr. The latter measurements determine the rate of the reverse reaction, 80Kr(γ , α) 76Se, an important waiting point in the synthesis of the p-nuclei. I will also discuss future (and ongoing) developments at DRAGON, including the commissioning of a new chamber for high-precision elastic scattering measurements and plans to determine the 330 keV resonance strength in 18F(p , γ) 19Ne via measurements of 15O(α , γ) 19Ne and 15O + α elastic scattering.

  5. Measurement resolution of noise directivity patterns from acoustic flight tests

    NASA Technical Reports Server (NTRS)

    Conner, David A.

    1989-01-01

    The measurement resolution of noise directivity patterns from acoustic flight tests was investigated. Directivity angle resolution is affected by the data reduction parameters, the aircraft velocity and flyover altitude, and by deviations of the aircraft from the desired flight path. Equations are developed which determine bounds for the lateral and longitudinal directivity angle resolution as a function of the nominal directivity angle. The equations are applied to a flight test data base and the effects of several flight conditions and data reduction parameters on the directivity angle resolution are presented. The maximum directivity angle resolution typically occurs when the aircraft is at or near the overhead position. In general, directivity angle resolution improves with decreasing velocity, increasing altitude, increasing sampling rate, decreasing block size, and decreasing block averages. Deviations from the desired ideal flight path will increase the resolution. For the flight experiment considered in this study, an average of two flyovers were required at each test condition to obtain an acceptable flight path. The ability of the pilot to maintain the flight track improved with decreasing altitude, decreasing velocity, and practice. Due to the prevailing wind conditions, yaw angles of as much as 20 deg were required to maintain the desired flight path.

  6. Note: Directly measuring the direct digital synthesizer frequency chirp-rate for an atom interferometer.

    PubMed

    Tao, Juan-Juan; Zhou, Min-Kang; Zhang, Qiao-Zhen; Cui, Jia-Feng; Duan, Xiao-Chun; Shao, Cheng-Gang; Hu, Zhong-Kun

    2015-09-01

    During gravity measurements with Raman type atom interferometry, the frequency of the laser used to drive Raman transition is scanned by chirping the frequency of a direct digital synthesizer (DDS), and the local gravity is determined by precisely measuring the chip rate α of DDS. We present an effective method that can directly evaluate the frequency chirp rate stability of our DDS. By mixing a pair of synchronous linear sweeping signals, the chirp rate fluctuation is precisely measured with a frequency counter. The measurement result shows that the relative α instability can reach 5.7 × 10(-11) in 1 s, which is neglectable in a 10(-9) g level atom interferometry gravimeter.

  7. Note: Directly measuring the direct digital synthesizer frequency chirp-rate for an atom interferometer

    SciTech Connect

    Tao, Juan-Juan; Zhou, Min-Kang E-mail: zmk@hust.edu.cn; Zhang, Qiao-Zhen; Cui, Jia-Feng; Duan, Xiao-Chun; Shao, Cheng-Gang; Hu, Zhong-Kun E-mail: zmk@hust.edu.cn

    2015-09-15

    During gravity measurements with Raman type atom interferometry, the frequency of the laser used to drive Raman transition is scanned by chirping the frequency of a direct digital synthesizer (DDS), and the local gravity is determined by precisely measuring the chip rate α of DDS. We present an effective method that can directly evaluate the frequency chirp rate stability of our DDS. By mixing a pair of synchronous linear sweeping signals, the chirp rate fluctuation is precisely measured with a frequency counter. The measurement result shows that the relative α instability can reach 5.7 × 10{sup −11} in 1 s, which is neglectable in a 10{sup −9} g level atom interferometry gravimeter.

  8. Non-additivity of molecule-surface van der Waals potentials from force measurements.

    PubMed

    Wagner, Christian; Fournier, Norman; Ruiz, Victor G; Li, Chen; Müllen, Klaus; Rohlfing, Michael; Tkatchenko, Alexandre; Temirov, Ruslan; Tautz, F Stefan

    2014-11-26

    Van der Waals (vdW) forces act ubiquitously in condensed matter. Despite being weak on an atomic level, they substantially influence molecular and biological systems due to their long range and system-size scaling. The difficulty to isolate and measure vdW forces on a single-molecule level causes our present understanding to be strongly theory based. Here we show measurements of the attractive potential between differently sized organic molecules and a metal surface using an atomic force microscope. Our choice of molecules and the large molecule-surface separation cause this attraction to be purely of vdW type. The experiment allows testing the asymptotic vdW force law and its validity range. We find a superlinear growth of the vdW attraction with molecular size, originating from the increased deconfinement of electrons in the molecules. Because such non-additive vdW contributions are not accounted for in most first-principles or empirical calculations, we suggest further development in that direction.

  9. Non-additivity of molecule-surface van der Waals potentials from force measurements

    PubMed Central

    Wagner, Christian; Fournier, Norman; Ruiz, Victor G.; Li, Chen; Müllen, Klaus; Rohlfing, Michael; Tkatchenko, Alexandre; Temirov, Ruslan; Tautz, F. Stefan

    2014-01-01

    Van der Waals (vdW) forces act ubiquitously in condensed matter. Despite being weak on an atomic level, they substantially influence molecular and biological systems due to their long range and system-size scaling. The difficulty to isolate and measure vdW forces on a single-molecule level causes our present understanding to be strongly theory based. Here we show measurements of the attractive potential between differently sized organic molecules and a metal surface using an atomic force microscope. Our choice of molecules and the large molecule-surface separation cause this attraction to be purely of vdW type. The experiment allows testing the asymptotic vdW force law and its validity range. We find a superlinear growth of the vdW attraction with molecular size, originating from the increased deconfinement of electrons in the molecules. Because such non-additive vdW contributions are not accounted for in most first-principles or empirical calculations, we suggest further development in that direction. PMID:25424490

  10. Direct Measurement of |V{sub tb}| at CDF

    SciTech Connect

    Tartarelli, G.F.

    1997-12-01

    We present a first direct measurement of the ratio of branching fractions R = B(t{r_arrow}Wb)/B(t{r_arrow}Wq), obtained by the CDF Collaboration. We measure R = 0.99 {+-} 0.29(stat+syst) in agreement with the Standard Model predictions. We use this result to measure the element |V{sub tb}| of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. We obtain |V{sub tb}| = 0.99 {+-} 0.15(stat+syst) which translates in the 90% confidence limit |V{sub tb}| {>=} 0.8. 3 refs., 1 fig., 1 tab.

  11. Modified Differential Scanning Calorimeter for Direct Electrocaloric Measurements.

    PubMed

    Sanlialp, Mehmet; Molin, Christian; Shvartsman, Vladimir V; Gebhardt, Sylvia; Lupascu, Doru C

    2016-10-01

    Solid-state refrigeration using the electrocaloric effect (ECE) in ferroelectric materials is a promising alternative to the conventional vapor-compression technology. In spite of growing interest to the investigation of the ECE, direct measurements of the effect are still rare. In this paper, we report on a modification of a differential scanning calorimeter for direct ECE measurements. The importance of proper estimation of the thermal correction factor and use of proper values of the heat capacitance for correct ECE measurements is discussed. The ECE measurements were performed for Ba(Zr0.2Ti0.8)O3 and Ba(Zr0.12Ti0.88)O3 bulk ceramics. Large electrocaloric temperature changes of 0.54 and 0.34 K are achieved under the application of an electric field of 2 kV/mm for the Ba(Zr0.12Ti0.88)O3 and Ba(Zr0.2Ti0.8)O3 samples, respectively. The relation between the directly measured ECE values and frequently used indirect estimation based on Maxwell's relations is discussed.

  12. Direct measurement of the forces generated by an undulatory microswimmer

    NASA Astrophysics Data System (ADS)

    Schulman, Rafael; Backholm, Matilda; Ryu, William; Dalnoki-Veress, Kari

    2014-11-01

    C. elegans is a millimeter-sized nematode which has served as a model organism in biology for several decades, primarily due to its simple anatomy. Employing an undulatory form of locomotion, this worm is capable of propelling itself through various media. Using a micropipette deflection technique, in conjunction with high speed imaging, we directly measure the time-varying forces generated by C. elegans. We observe excellent agreement between our measured forces and the predictions of resistive force theory, through which we determine the drag coefficients of the worm. We also perform the direct force measurements at controlled distances from a single solid boundary as well as between two solid boundaries. We extract the drag coefficients of the worm to quantify the influence of the boundary on the swimming and the hydrodynamic forces involved.

  13. Measurement of proton momentum distributions using a direct geometry instrument

    NASA Astrophysics Data System (ADS)

    Senesi, R.; Kolesnikov, A. I.; Andreani, C.

    2014-12-01

    We report the results of inelastic neutron scattering measurements on bulk water and ice using the direct geometry SEQUOIA chopper spectrometer at the Spallation Neutron Source (USA), with incident energy Ei= 6 eV. In this set up the measurements allow to access the Deep Inelastic Neutron Scattering regime. The scattering is centred at the proton recoil energy given by the impulse approximation, and the shape of the recoil peak conveys information on the proton momentum distribution in the system. The comparison with the performance of inverse geometry instruments, such as VESUVIO at the ISIS source (UK), shows that complementary information can be accessed by the use of direct and inverse geometry instruments. Analysis of the neutron Compton profiles shows that the proton kinetic energy in ice at 271 K is larger than in room temperature liquid water, in agreement with previous measurements on VESUVIO.

  14. Genetic algorithm-guided discovery of additive combinations that direct quantum dot assembly.

    PubMed

    Bawazer, Lukmaan A; Ihli, Johannes; Comyn, Timothy P; Critchley, Kevin; Empson, Christopher J; Meldrum, Fiona C

    2015-01-14

    The use of combinations of organic additives to control crystallization, as occurs in biomineralization, is rarely investigated due to the vast potential reaction space. It is demonstrated here that combinatorial approaches led by genetic algorithm heuristics can enable identification of active additive combinations, and four key organic molecules are rapidly identified, which generate highly fluorescent CdS quantum dot superstructures. © 2014 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Design and Use of Microphone Directional Arrays for Aeroacoustic Measurements

    NASA Technical Reports Server (NTRS)

    Humphreys, William M., Jr.; Brooks, Thomas F.; Hunter, William W., Jr.; Meadows, Kristine R.

    1998-01-01

    An overview of the development of two microphone directional arrays for aeroacoustic testing is presented. These arrays were specifically developed to measure airframe noise in the NASA Langley Quiet Flow Facility. A large aperture directional array using 35 flush-mounted microphones was constructed to obtain high resolution noise localization maps around airframe models. This array possesses a maximum diagonal aperture size of 34 inches. A unique logarithmic spiral layout design was chosen for the targeted frequency range of 2-30 kHz. Complementing the large array is a small aperture directional array, constructed to obtain spectra and directivity information from regions on the model. This array, possessing 33 microphones with a maximum diagonal aperture size of 7.76 inches, is easily moved about the model in elevation and azimuth. Custom microphone shading algorithms have been developed to provide a frequency- and position-invariant sensing area from 10-40 kHz with an overall targeted frequency range for the array of 5-60 kHz. Both arrays are employed in acoustic measurements of a 6 percent of full scale airframe model consisting of a main element NACA 632-215 wing section with a 30 percent chord half-span flap. Representative data obtained from these measurements is presented, along with details of the array calibration and data post-processing procedures.

  16. Procedure for direct measurement of general quantum states using weak measurement.

    PubMed

    Lundeen, Jeff S; Bamber, Charles

    2012-02-17

    Recent work by Lundeen et al. [Nature (London) 474, 188 (2011)] directly measured the wave function by weakly measuring a variable followed by a normal (i.e., "strong") measurement of the complementary variable. We generalize this method to mixed states by considering the weak measurement of various products of these observables, thereby providing the density matrix an operational definition in terms of a procedure for its direct measurement. The method only requires measurements in two bases and can be performed in situ, determining the quantum state without destroying it.

  17. Effect of polymer additives on characteristics of direct-current motor with liquid dielectric filler

    NASA Astrophysics Data System (ADS)

    Ivanov, V. I.; Bashkatova, S. T.; Lubsanova, A. A.; Tokarev, S. B.; Zadaroshnaya, G. N.; Pastukhova, I. N.

    1984-11-01

    In d.c. motors filled with dielectric of the hydrocarbon kind hydrodynamic losses can constitute up to 40% of the total losses. Consequently, a study was made to determine the proper additive and amount to reduce the hydraulic drag without dehomogenizing the liquid filler over long operating periods. Two polymethacrylates, never before used for this application were selected. Two motors of different size, a 0.8 kW DPK and a 6 kW DPK, were tested in kerosene with 0.005-1.0 wt% of these additives. An evaluation of the data, including the hydraulic drag coefficient as a function of the Reynolds number and the temperature rise at critical motor components (armature winding in slots, armature endturns on drive side, armature teeth, liquid in interpolar space, field winding, pole pieces) with or without additive, has yielded the optimum range of additive concentration for each motor size. An evaluation of the heat transfer at critical surfaces, with the aid of dimensional analysis, has yielded the semiempirical relation Nu=CRe0.65Pr0.4Km (C- constant factor different for each surface, Km- constant factor with exponent different for each additive polymer materials). The results can be extended to transformer oil and diesel oil as liquid motor-filling medium.

  18. Direct Measurement of Left Atrial Pressure during Routine Transradial Catheterization

    PubMed Central

    Fa'ak, Faisal; Younis, George

    2016-01-01

    Left atrial pressure indicates the left ventricular filling pressure in patients who have systolic or diastolic left ventricular dysfunction or valvular heart disease. The use of indirect surrogate methods to determine left atrial pressure has been essential in the modern evaluation and treatment of cardiovascular disease because of the difficulty and inherent risks associated with direct methods (typically the transseptal approach). One method that has been widely used to determine left atrial pressure indirectly is Swan-Ganz catheterization, in which a balloon-flotation technique is applied to measure pulmonary capillary wedge pressure; however, this approach has been associated with several limitations and potential risks. Measuring left ventricular end-diastolic pressure has also been widely used as a simple means to estimate filling pressures but remains a surrogate for the gold standard of directly measuring left atrial pressure. We describe a simple, low-risk method to directly measure left atrial pressure that involves the use of standard coronary catheterization techniques during a transradial procedure. PMID:28100968

  19. Template-dependent nucleotide addition in the reverse (3′-5′) direction by Thg1-like protein

    PubMed Central

    Kimura, Shoko; Suzuki, Tateki; Chen, Meirong; Kato, Koji; Yu, Jian; Nakamura, Akiyoshi; Tanaka, Isao; Yao, Min

    2016-01-01

    Thg1-like protein (TLP) catalyzes the addition of a nucleotide to the 5′-end of truncated transfer RNA (tRNA) species in a Watson-Crick template–dependent manner. The reaction proceeds in two steps: the activation of the 5′-end by adenosine 5′-triphosphate (ATP)/guanosine 5′-triphosphate (GTP), followed by nucleotide addition. Structural analyses of the TLP and its reaction intermediates have revealed the atomic detail of the template-dependent elongation reaction in the 3′-5′ direction. The enzyme creates two substrate binding sites for the first- and second-step reactions in the vicinity of one reaction center consisting of two Mg2+ ions, and the two reactions are executed at the same reaction center in a stepwise fashion. When the incoming nucleotide is bound to the second binding site with Watson-Crick hydrogen bonds, the 3′-OH of the incoming nucleotide and the 5′-triphosphate of the tRNA are moved to the reaction center where the first reaction has occurred. That the 3′-5′ elongation enzyme performs this elaborate two-step reaction in one catalytic center suggests that these two reactions have been inseparable throughout the process of protein evolution. Although TLP and Thg1 have similar tetrameric organization, the tRNA binding mode of TLP is different from that of Thg1, a tRNAHis-specific G−1 addition enzyme. Each tRNAHis binds to three of the four Thg1 tetramer subunits, whereas in TLP, tRNA only binds to a dimer interface and the elongation reaction is terminated by measuring the accepter stem length through the flexible β-hairpin. Furthermore, mutational analyses show that tRNAHis is bound to TLP in a similar manner as Thg1, thus indicating that TLP has a dual binding mode. PMID:27051866

  20. Organocatalysis by Networks of Cooperative Hydrogen Bonds: Enantioselective Direct Mannich Addition to Preformed Arylideneureas.

    PubMed

    Lillo, Victor J; Mansilla, Javier; Saá, José M

    2016-03-18

    The concept of noncovalent organocatalysis by means of networks of cooperative hydrogen bonds (NCHB organocatalysis) has been explored. Arylideneureas were chosen as ideal substrates because of their powerful donor-acceptor properties. We have examined their uncatalyzed, direct Mannich reaction with acetoacetates in comparison with that catalyzed by a number of salan derivatives capable of providing a network of cooperative hydrogen bonds. Catalyst D [(R,R)-N,N'-bis(salicyl)cyclohexane-1,2-diamine] was found to drive the above direct Mannich reaction in an enantioselective manner, thereby allowing the synthesis of several Biginelli dihydropyrimidinones with high enantioselectivity. DFT calculations (B3LYP-D-PCM/6-31+G*//B3LYP/6-31+G*) revealed that the NCHB organocatalyst lowers the energy barrier of the reaction. The NCHB organocatalysts appear to function as biomimetic catalysts. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Direct shaft torque measurements in a transient turbine facility

    NASA Astrophysics Data System (ADS)

    Beard, Paul F.; Povey, Thomas

    2011-03-01

    This paper describes the development and implementation of a shaft torque measurement system for the Oxford Turbine Research Facility (formerly the Turbine Test Facility (TTF) at QinetiQ, Farnborough), or OTRF. As part of the recent EU TATEF II programme, the facility was upgraded to allow turbine efficiency measurements to be performed. A shaft torque measurement system was developed as part of this upgrade. The system is unique in that, to the authors' knowledge, it provided the first direct measurement of shaft torque in a transient turbine facility although the system has wider applicability to rotating test facilities in which power measurement is a requirement. The adopted approach removes the requirement to quantify bearing friction, which can be difficult to accurately calibrate under representative operating conditions. The OTRF is a short duration (approximately 0.4 s run time) isentropic light-piston facility capable of matching all of the non-dimensional parameters important for aerodynamic and heat studies, namely Mach number, Reynolds number, non-dimensional speed, stage pressure ratio and gas-to-wall temperature ratio. The single-stage MT1 turbine used for this study is a highly loaded unshrouded design, and as such is relevant to modern military, or future civil aero-engine design. Shaft torque was measured directly using a custom-built strain gauge-based torque measurement system in the rotating frame of reference. This paper describes the development of this measurement system. The system was calibrated, including the effects of temperature, to a traceable primary standard using a purpose-built facility. The bias and precision uncertainties of the measured torque were ±0.117% and ±0.183%, respectively. To accurately determine the shaft torque developed by a turbine in the OTRF, small corrections due to inertial torque (associated with changes in the rotational speed) and aerodynamic drag (windage) are required. The methods for performing these

  2. Influence of Additive and Multiplicative Structure and Direction of Comparison on the Reversal Error

    ERIC Educational Resources Information Center

    González-Calero, José Antonio; Arnau, David; Laserna-Belenguer, Belén

    2015-01-01

    An empirical study has been carried out to evaluate the potential of word order matching and static comparison as explanatory models of reversal error. Data was collected from 214 undergraduate students who translated a set of additive and multiplicative comparisons expressed in Spanish into algebraic language. In these multiplicative comparisons…

  3. Influence of Additive and Multiplicative Structure and Direction of Comparison on the Reversal Error

    ERIC Educational Resources Information Center

    González-Calero, José Antonio; Arnau, David; Laserna-Belenguer, Belén

    2015-01-01

    An empirical study has been carried out to evaluate the potential of word order matching and static comparison as explanatory models of reversal error. Data was collected from 214 undergraduate students who translated a set of additive and multiplicative comparisons expressed in Spanish into algebraic language. In these multiplicative comparisons…

  4. Direct measurements of transport properties are essential for site characterization

    SciTech Connect

    Wright, J.; Conca, J.L.

    1994-08-01

    Direct measurements of transport parameters on subsurface sediments using, the UFA method provided detailed hydrostratigraphic mapping, and subsurface flux distributions at a mixed-waste disposal site at Hanford. Seven hundred unsaturated conductivity measurements on fifty samples were obtained in only six months total of UFA run time. These data are used to provide realistic information to conceptual models, predictive models and restoration strategies. The UFA instrument consists of an ultracentrifuge with a constant, ultralow flow pump that provides fluid to the sample surface through a rotating seal assembly and microdispersal system. Effluent from the sample is collected in a transparent, volumetrically-calibrated chamber at the bottom of the sample assembly. Using a strobe light, an observer can check the chamber while the sample is being centrifuged. Materials can be run in the UFA as recomposited samples or in situ samples can be subcored directly into the sample UFA chamber.

  5. Direct measurements of skin friction in a scramjet combustor

    NASA Technical Reports Server (NTRS)

    Deturris, D. J.; Schetz, J. A.; Hellbaum, R. F.

    1990-01-01

    A direction experimental measurement was made of the skin friction in the turbulent boundary layer of three-dimensional supersonic combustor flows. A floating element configuration was designed to detect two components of the small tangential shear forces due to the flow passing over a nonobtrusive instrument. A cantilevered sensing head extending from a very sensitive piezoresistive displacement transducer simultaneously measured displacement in the axial and transverse directions to the flow. The small overall deflection means that no self-nulling is required. Consistently repeatable output from the gage during testing show the skin friction with supersonic combustion is higher than for a corresponding noncombusting flow. The results are probably accurate to within 10 percent for the mean streamwise component.

  6. Direct thrust measurement of a 30-cm ion thruster

    NASA Technical Reports Server (NTRS)

    Banks, B.; Rawlin, V.; Weigand, A. J.; Walker, J.

    1975-01-01

    A direct thrust measurement of a 30-cm diameter ion thruster was accomplished by means of a laser interferometer thrust stand. The thruster was supported in a pendulum manner by three 3.65-m long wires. Electrical power was provided by means of 18 mercury filled pots. A movable 23-button planar probe rake was used to determine thrust loss due to ion beam divergence. Values of thrust, thrust loss due to ion beam divergence, and thrust loss due to multiple ionization were measured for ion beam currents ranging from 0.5 A to 2.5 A. Measured thrust values indicate an accuracy of approximately 1% and are in good agreement with thrust values calculated by indirect measurements.

  7. Direct measurement of mixing quality in a pulsatile flow micromixer

    NASA Astrophysics Data System (ADS)

    Truesdell, Richard A.; Bartsch, J. W.; Buranda, T.; Sklar, L. A.; Mammoli, A. A.

    2005-11-01

    Pulsatile action can be used to mix two streams entering a tube from two separate branches of a bifurcation at low Reynolds numbers. The pulsatile action is provided by two pinch valves, which deform flexible tubing immediately upstream of the connection. The pinch valve action is controlled using a master-slave pulse generator setup. The quality of mixing is evaluated directly by measuring the fluorescence that results from the chemical reaction of species transported in the two streams, one containing native biotin and the other, fluorescein biotin bound to streptavidin. The reaction kinetics are accounted for by normalization using fluorescence measurements on well mixed solutions at the same residence time. The results show that the pulsatile micromixer provides almost complete mixing. Furthermore, the present measurements match results obtained in a previous experiment where flow visualization and image analysis were used to measure mixing quality in a scaled-up model.

  8. Direct Measurements of the Convective Recycling of the Upper Troposphere

    NASA Technical Reports Server (NTRS)

    Bertram, Timothy H.; Perring, Anne E.; Wooldridge, Paul J.; Crounse, John D.; Kwan, Alan J.; Wennberg, Paul O.; Scheuer, Eric; Dibb, Jack; Avery, Melody; Sachse, Glen; Vay, Stephanie A.; Crawford, James H.; McNaughton, Cameron S.; Clarke, Antony; Pickering, Kenneth E.; Fuelberg, Henry; Huey, Greg; Blake, Donald R.; Singh, Hanwant B.; Hall, Samuel R.; Shetter, Richard E.; Fried, Alan; Heikes, Brian G.; Cohen, Ronald C.

    2007-01-01

    We present a statistical representation of the aggregate effects of deep convection on the chemistry and dynamics of the Upper Troposphere (UT) based on direct aircraft observations of the chemical composition of the UT over the Eastern United States and Canada during summer. These measurements provide new and unique observational constraints on the chemistry occurring downwind of convection and the rate at which air in the UT is recycled, previously only the province of model analyses. These results provide quantitative measures that can be used to evaluate global climate and chemistry models.

  9. Direct field measurement of the dynamic amplification in a bridge

    NASA Astrophysics Data System (ADS)

    Carey, Ciarán; OBrien, Eugene J.; Malekjafarian, Abdollah; Lydon, Myra; Taylor, Su

    2017-02-01

    In this paper, the level of dynamics, as described by the Assessment Dynamic Ratio (ADR), is measured directly through a field test on a bridge in the United Kingdom. The bridge was instrumented using fiber optic strain sensors and piezo-polymer weigh-in-motion sensors were installed in the pavement on the approach road. Field measurements of static and static-plus-dynamic strains were taken over 45 days. The results show that, while dynamic amplification is large for many loading events, these tend not to be the critical events. ADR, the allowance that should be made for dynamics in an assessment of safety, is small.

  10. Some basic considerations of measurements involving collimated direct sunlight

    NASA Technical Reports Server (NTRS)

    Chai, A. T.

    1976-01-01

    The geometry of collimators for devices or instruments dealing with terrestrial direct sunlight is discussed. Effects of the opening angle and slope angle of a collimator on the measurements are investigated with regard to variations of turbidity and air mass. Based on this investigation, geometric dimensions for collimators and certain realistic terrestrial reference conditions are recommended for the purpose of solar cell calibration in terrestrial applications.

  11. Radionuclide counting technique for measuring wind velocity and direction

    NASA Technical Reports Server (NTRS)

    Singh, J. J. (Inventor)

    1984-01-01

    An anemometer utilizing a radionuclide counting technique for measuring both the velocity and the direction of wind is described. A pendulum consisting of a wire and a ball with a source of radiation on the lower surface of the ball is positioned by the wind. Detectors and are located in a plane perpendicular to pendulum (no wind). The detectors are located on the circumferene of a circle and are equidistant from each other as well as the undisturbed (no wind) source ball position.

  12. Direct Measurement of Pyroelectric and Electrocaloric Effects in Thin Films

    NASA Astrophysics Data System (ADS)

    Pandya, Shishir; Wilbur, Joshua D.; Bhatia, Bikram; Damodaran, Anoop R.; Monachon, Christian; Dasgupta, Arvind; King, William P.; Dames, Chris; Martin, Lane W.

    2017-03-01

    An understanding of polarization-heat interactions in pyroelectric and electrocaloric thin-film materials requires that the electrothermal response is reliably characterized. While most work, particularly in electrocalorics, has relied on indirect measurement protocols, here we report a direct technique for measuring both pyroelectric and electrocaloric effects in epitaxial ferroelectric thin films. We demonstrate an electrothermal test platform where localized high-frequency (approximately 1 kHz) periodic heating and highly sensitive thin-film resistance thermometry allow the direct measurement of pyrocurrents (<10 pA ) and electrocaloric temperature changes (<2 mK ) using the "2-omega" and an adapted "3-omega" technique, respectively. Frequency-domain, phase-sensitive detection permits the extraction of the pyrocurrent from the total current, which is often convoluted by thermally-stimulated currents. The wide-frequency-range measurements employed in this study further show the effect of secondary contributions to pyroelectricity due to the mechanical constraints of the substrate. Similarly, measurement of the electrocaloric effect on the same device in the frequency domain (at approximately 100 kHz) allows for the decoupling of Joule heating from the electrocaloric effect. Using one-dimensional, analytical heat-transport models, the transient temperature profile of the heterostructure is characterized to extract pyroelectric and electrocaloric coefficients.

  13. Measurement of directed blood flow by laser speckle

    NASA Astrophysics Data System (ADS)

    Hirst, Evan R.; Thompson, Oliver B.; Andrews, Michael K.

    2011-03-01

    Recent success in reconciling laser Doppler and speckle measurements of dermal perfusion by the use of multi-exposure speckle has prompted an investigation of speckle effects arising from directed blood flow which might be expected in the small blood vessels of the eye. Unlike dermal scatter, the blood in retinal vessels is surrounded by few small and stationary scatterers able to assist the return of light energy by large-angle scatter. Returning light is expected to come from multiple small angle scatter from the large red blood cells which dominate the fluid. This work compares speckle measurements on highly scattering skin, with measurements on flow in a retinal phantom consisting of a glass capillary which is itself immersed in an index matching fluid to provide a flat air-phantom interface. Brownian motion dominated measurements when small easily levitated scatters were used, and flow was undetectable. With whole-blood, Brownian motion was small and directed flows in the expected region of tens of mm/s were detectable. The nominal flow speed relates to the known pump rate; within the capillary the flow will have a profile reducing toward the walls. The pulsatile effects on laser speckle contrast in the retina are discussed with preliminary multi-exposure measurements on retinal vessels using a fundus camera. Differences between the multiple exposure curves and power spectra of perfused tissue and ordered flow are discussed.

  14. Direct Solar Irradiance measurements with a Cryogenic Solar Absolute Radiometer

    NASA Astrophysics Data System (ADS)

    Walter, Benjamin; Winkler, Rainer; Graber, Florian; Finsterle, Wolfgang; Fox, Nigel; Li, Vivian; Schmutz, Werner

    2017-02-01

    The World Radiometric Reference (WRR) is an artefact based reference for Direct Solar Irradiance (DSI) measurements. The WRR is realized by a group of electrical substitution radiometers, the World Standard Group (WSG). In recent years, a relative difference of about -0.3% between the International System of Units (SI) scale and the WRR scale was observed with the SI scale being lower. The Cryogenic Solar Absolute Radiometer (CSAR) aims for i) providing direct traceability of DSI measurements to the SI system, ii) reducing the overall uncertainty of DSI measurements towards 0.01% and for iii) replacing the WSG in future. The latest SI-WRR intercomparisons performed with CSAR revealed a relative difference of -0.29% ± 0.064% (k = 1) between the SI and the WRR scale, a result that agrees well with previous findings. The uncertainty of corrections for the window transmittance results currently in the largest contribution to the total uncertainty for the CSAR measurements. The formal transition from the WRR to the SI-scale for DSI measurements is currently being discussed in the WMO/CIMO Task Team on Radiation References.

  15. Direct Measurement of the Surface Energy of Graphene.

    PubMed

    van Engers, Christian D; Cousens, Nico E A; Babenko, Vitaliy; Britton, Jude; Zappone, Bruno; Grobert, Nicole; Perkin, Susan

    2017-06-14

    Graphene produced by chemical vapor deposition (CVD) is a promising candidate for implementing graphene in a range of technologies. In most device configurations, one side of the graphene is supported by a solid substrate, wheras the other side is in contact with a medium of interest, such as a liquid or other two-dimensional material within a van der Waals stack. In such devices, graphene interacts on both faces via noncovalent interactions and therefore surface energies are key parameters for device fabrication and operation. In this work, we directly measured adhesive forces and surface energies of CVD-grown graphene in dry nitrogen, water, and sodium cholate using a modified surface force balance. For this, we fabricated large (∼1 cm(2)) and clean graphene-coated surfaces with smooth topography at both macro- and nanoscales. By bringing two such surfaces into contact and measuring the force required to separate them, we measured the surface energy of single-layer graphene in dry nitrogen to be 115 ± 4 mJ/m(2), which was similar to that of few-layer graphene (119 ± 3 mJ/m(2)). In water and sodium cholate, we measured interfacial energies of 83 ± 7 and 29 ± 6 mJ/m(2), respectively. Our work provides the first direct measurement of graphene surface energy and is expected to have an impact both on the development of graphene-based devices and contribute to the fundamental understanding of surface interactions.

  16. Tophaceous gout: quantitative evaluation by direct physical measurement.

    PubMed

    Schumacher, H Ralph; Becker, Michael A; Palo, William A; Streit, Janet; MacDonald, Patricia A; Joseph-Ridge, Nancy

    2005-12-01

    The absence of accepted standardized methods for monitoring tophaceous gout limits the ability to track tophus progression or regression. This multicenter study assessed intra- and interrater reproducibility of a simple and direct physical measurement. The quantitative evaluation was the area (mm2) of each measurable tophus and was determined independently by 2 raters on 2 occasions within 10 days. Intra- and interrater reproducibilities were determined by calculating mean differences and average percentage differences (APD) in measurements of areas for the same tophus at each of 2 visits and by each rater, respectively. Fifty-two tophi were measured in 13 subjects: 22 on the hand/wrist, 16 on the elbow, and 14 on the foot/ankle. The mean (+/- SD) difference in tophus areas between visits was -0.2 +/- 835 mm2 (95% CI -162 to 162 mm2) and the mean (+/- SD) APD was 29% +/- 33%. The mean (+/- SD) APD between raters was 32% +/- 27%. The largest variations in measurements were noted for elbow tophi and variations were least for well demarcated tophi on the hands. This simple and reproducible method can be easily utilized in clinical trials and in practice as a measure of efficacy of urate-lowering treatment in tophaceous gout. Among factors contributing to variability in these measurements were the anatomic site of tophi and rater experience with the method. Restriction of measurements to well circumscribed hand or foot tophi could improve reliability, but major changes, as expected with effective therapy, can clearly be documented with this simple technique.

  17. Rationalization of Microstructure Heterogeneity in INCONEL 718 Builds Made by the Direct Laser Additive Manufacturing Process

    NASA Astrophysics Data System (ADS)

    Tian, Yuan; McAllister, Donald; Colijn, Hendrik; Mills, Michael; Farson, Dave; Nordin, Mark; Babu, Sudarsanam

    2014-09-01

    Simulative builds, typical of the tip-repair procedure, with matching compositions were deposited on an INCONEL 718 substrate using the laser additive manufacturing process. In the as-processed condition, these builds exhibit spatial heterogeneity in microstructure. Electron backscattering diffraction analyses showed highly misoriented grains in the top region of the builds compared to those of the lower region. Hardness maps indicated a 30 pct hardness increase in build regions close to the substrate over those of the top regions. Detailed multiscale characterizations, through scanning electron microscopy, electron backscattered diffraction imaging, high-resolution transmission electron microscopy, and ChemiSTEM, also showed microstructure heterogeneities within the builds in different length scales including interdendritic and interprecipitate regions. These multiscale heterogeneities were correlated to primary solidification, remelting, and solid-state precipitation kinetics of γ″ induced by solute segregation, as well as multiple heating and cooling cycles induced by the laser additive manufacturing process.

  18. Development of coatings for ultrasonic additive manufacturing sonotrode using laser direct metal deposition process

    SciTech Connect

    Sridharan, Niyanth; Dehoff, Ryan R.; Jordan, Brian H.; Babu, Sudarsanam Suresh

    2016-10-01

    ORNL partnered with Fabrisonic, LLC to develop galling resistant hard facing coatings on sonotrodes used to fabricate 3D printed materials using ultrasonic additive manufacturing. The development and deployment of a coated sonotrode is expected to push the existing state of the art to facilitate the solidstate additive manufacturing of hard steels and titanium alloys. To this effect a structurally amorphous stainless steel material and cobalt chrome material were deposited on the sonotrode material. Both the deposits showed good adhesion to the substrate. The coatings made using the structurally amorphous steel materials showed cracking during the initial trials and cracking was eliminated by deposition on a preheated substrate. Both the coatings show hardness in excess of 600 HVN. Thus the phase 1 of this project has been used to identify suitable materials to use to coat the sonotrode. Despite the fact that successful deposits were obtained, the coatings need to be evaluated by performing detailed galling tests at various temperatures. In addition field tests are also necessary to test the stability of these coatings in a high cycle ultrasonic vibration mode. If awarded, phase 2 of the project would be used to optimize the composition of the deposit material to maximize galling resistance. The industrial partner would then use the coated sonotrode to fabricate builds made of austenitic stainless steel to test the viability of using a coated sonotrode.

  19. 49 CFR 192.935 - What additional preventive and mitigative measures must an operator take?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false What additional preventive and mitigative measures... STANDARDS Gas Transmission Pipeline Integrity Management § 192.935 What additional preventive and mitigative... those already required by Part 192 to prevent a pipeline failure and to mitigate the consequences of a...

  20. Effect of halide and acid additives on the direct synthesis of hydrogen peroxide using supported gold-palladium catalysts.

    PubMed

    Ntainjua N, Edwin; Piccinini, Marco; Pritchard, James C; Edwards, Jennifer K; Carley, Albert F; Moulijn, Jacob A; Hutchings, Graham J

    2009-01-01

    The effect of halide and acid addition on the direct synthesis of hydrogen peroxide is studied for magnesium oxide- and carbon-supported bimetallic gold-palladium catalysts. The addition of acids decreases the hydrogenation/decomposition of hydrogen peroxide, and the effect is particularly pronounced for the magnesium oxide-supported catalysts whilst for carbon-supported catalysts the pH requires close control to optimize hydrogen peroxide synthesis. The addition of bromide leads to a marked decrease in the hydrogenation/decomposition of hydrogen peroxide with either catalyst. These effects are discussed in terms of the structure of the gold-palladium alloy nanoparticles and the isoelectric point of the support. We conclude that with the highly active carbon-supported gold-palladium catalysts these additives are not required and that therefore this system presents the potential for the direct synthesis of hydrogen peroxide to be operated using green process technology.

  1. Catalytic Direct-type 1,4-Addition Reactions of Alkylazaarenes.

    PubMed

    Suzuki, Hirotsugu; Igarashi, Ryo; Yamashita, Yasuhiro; Kobayashi, Shū

    2017-04-10

    1,4-addition reactions of alkylazaarenes catalyzed by strong Brønsted bases have been developed for the first time. The desired reactions with α,β-unsaturated amides proceeded under mild reaction conditions to give the 1,4-adducts in high yields. Both ortho- and para-substituted azaarenes afforded the desired adducts in high yields. Regioselective reactions of di- or trimethylpyridine were found to be possible depending on the acidity of the α-hydrogen atoms. Furthermore, a candidate of allosteric protein kinase modulators was synthesized in two steps. An asymmetric variant of this reaction was also found to be feasible.

  2. Incidental vesicocolic fistula on routine bone scintigraphy: Value of additional delayed images and direct radionuclide cystography.

    PubMed

    Sohn, Myung-Hee; Tae Lim, Seok; Jin Jeong, Young; Wook Kim, Dong; Jeong, Hwan-Jeong; Yim, Chang-Yeol

    2010-09-01

    An unexpected vesicocolic fistula can be detected incidentally on routine bone scintigraphy. A 55-year-old man who had a radical colectomy for carcinoma of the sigmoid colon 1 year previously underwent bone scintigraphy to evaluate bone metastasis. Whole-body images showed an abnormal accumulation of radioactivity in the right lower quadrant of the abdomen, but the radioactivity did not precisely define a structure. Additional delayed images obtained after 15 and 24 hours of the initial image localized a vesicocolic fistula. Subsequent radionuclide cystography confirmed leakage of the radioactivity from the bladder.

  3. The Direct Measurement of Base Drag for Hypersonic Vehicles

    NASA Astrophysics Data System (ADS)

    Lv, Zhi-guo; Li, Guo-jun; Jiang, Hua; Zhao, Rong-juan; Wang, Gang; Huang, Jun

    A new base drag measurement method has been introduced in this paper. In tradition method, the base drag of the model was measured by the pressure transducer located on the bottom of the model. In this method, the base drag was measured with piezoelectric balance directly. The drag force was measured twice by fixing the model base segment to the model or the balance, the difference between these two measurements is considered as the base drag of the model. The wind tunnel test was carried out in φ0.6m shock tunnel of CARDC with a cone model. The base drag of cone model was measured in the flow field of M(=8.42, Re(l=9.67(106/m with the attack angle of 0(. The results showed that the base drag coefficient of the cone model is 0.0015. It means that the base drag can't be ignored in high precision tests, and it can be measured by piezoelectric balance in shock tunnel. The length of the tail sting affects the axis force test result. In the same attack angle, the base drag of high lift/drag ratio model decreases with the increasing of flow field Mach number.

  4. Statistical length measurement method by direct imaging of carbon nanotubes.

    PubMed

    Bengio, E Amram; Tsentalovich, Dmitri E; Behabtu, Natnael; Kleinerman, Olga; Kesselman, Ellina; Schmidt, Judith; Talmon, Yeshayahu; Pasquali, Matteo

    2014-05-14

    The influence of carbon nanotube (CNT) length on their macroscopic properties requires an accurate methodology for CNT length measurement. So far, existing techniques are limited to short (less than a few micrometers) CNTs and sample preparation methods that bias the measured values. Here, we show that the average length of carbon nanotubes (CNTs) can be measured by cryogenic transmission electron microscopy (cryo-TEM) of CNTs in chlorosulfonic acid. The method consists of dissolving at low concentration CNTs in chlorosulfonic acid (a true solvent), imaging the individual CNTs by cryo-TEM, and processing and analyzing the images to determine CNT length. By measuring the total CNT contour length and number of CNT ends in each image, and by applying statistical analysis, we extend the method to cases where each CNT is long enough to span many cryo-TEM images, making the direct length measurement of an entire CNT impractical. Hence, this new technique can be used effectively to estimate samples in a wide range of CNT lengths, although we find that cryo-TEM imaging may bias the measurement towards longer CNTs, which are easier to detect. Our statistical method is also applied to AFM images of CNTs to show that, by using only a few AFM images, it yields estimates that are consistent with literature techniques, based on individually measuring a higher number of CNTs.

  5. Direct Measurement of Photon Recoil from a Levitated Nanoparticle

    NASA Astrophysics Data System (ADS)

    Jain, Vijay; Gieseler, Jan; Moritz, Clemens; Dellago, Christoph; Quidant, Romain; Novotny, Lukas

    2016-06-01

    The momentum transfer between a photon and an object defines a fundamental limit for the precision with which the object can be measured. If the object oscillates at a frequency Ω0 , this measurement backaction adds quanta ℏΩ0 to the oscillator's energy at a rate Γrecoil, a process called photon recoil heating, and sets bounds to coherence times in cavity optomechanical systems. Here, we use an optically levitated nanoparticle in ultrahigh vacuum to directly measure Γrecoil. By means of a phase-sensitive feedback scheme, we cool the harmonic motion of the nanoparticle from ambient to microkelvin temperatures and measure its reheating rate under the influence of the radiation field. The recoil heating rate is measured for different particle sizes and for different excitation powers, without the need for cavity optics or cryogenic environments. The measurements are in quantitative agreement with theoretical predictions and provide valuable guidance for the realization of quantum ground-state cooling protocols and the measurement of ultrasmall forces.

  6. Engineered NADH-dependent GRE2 from Saccharomyces cerevisiae by directed enzyme evolution enhances HMF reduction using additional cofactor NADPH.

    PubMed

    Moon, Jaewoong; Liu, Z Lewis

    2012-02-10

    Furfural and 5-hydroxymethylfurfural (HMF) are inhibitors generated by lignocellulosic biomass pretreatment such as dilute acid hydrolysis that inhibit microbial growth and interfere with subsequent fermentation. It is possible to in situ detoxify these inhibitory compounds by aldehyde reductions using tolerant Saccharomyces cerevisiae. YOL151W (GRE2) is a commonly recognized up-regulated gene expressed under stress conditions that encodes reductase activities toward furfural and HMF using cofactor NADH. Applying a directed enzyme evolution approach, we altered the genetic code of GRE2 yielding two mutants with amino acid substitutions of Gln261 to Arg261 and Phe283 to Leu283; and Ile107 to Val107, Gln261 to Arg261, and Val285 to Asp285 for strain Y62-C11 and Y62-G6, respectively. Clones of these mutants showed faster growth rates and were able to establish viable cultures under 30 mM HMF challenges when compared with a wild type GRE2 clone when inoculated into synthetic medium containing this inhibitor. Compared with the wild type control, crude cell extracts of the two mutants showed 3- to 4-fold and 3- to 9-fold increased specific enzyme activity using NADH toward HMF and furfural reduction, respectively. While retaining its aldehyde reductase activities using the cofactor NADH, mutant Y62-G6 displayed significantly greater reductase activities using NADPH as the cofactor with 13- and 15-fold increase toward furfural and HMF, respectively, as measured by its partially purified protein. Using reverse engineering and site directed mutagenesis methods, we were able to confirm that the amino acid substitution of the Asp285 is responsible for the increased aldehyde reductase activities by utilizing the additional cofactor NADPH. Published by Elsevier Inc.

  7. Indirect vs direct measurement of magnesium and zinc in erythrocytes.

    PubMed

    Deuster, P A; Trostmann, U H; Bernier, L L; Dolev, E

    1987-04-01

    We evaluated three methods (two indirect and one direct) for determining the magnesium (Mg) and zinc (Zn) content of erythrocytes, to compare methodologic differences and to establish a method suitable for use in field studies. For the indirect methods, erythrocytes in whole blood were lysed by adding either de-ionized water (I) or nitric acid, 2 mol/L (II). For the direct method (III), erythrocytes were isolated by density centrifugation, washed, then digested in concentrated HNO3. Mg and Zn concentrations were measured by atomic absorption spectrophotometry in plasma and whole blood for the indirect methods, and in the pellet for the direct method. Hematocrit and hemoglobin were measured, and erythrocytes were sized and counted on all samples. Within-run CVs for the three methods ranged from 2.2% with method III for Mg to 5.4% with method I for Zn. CVs for reproducibility of the analytical procedures ranged from 2.6% with method II for Zn to 4.2% with method I for the two cations. Analytical recoveries of added Mg and Zn ranged from 93.8 to 104.7%. When values for the three methods were compared, those by method I were significantly (p less than 0.05) lower than those by methods II and III. Values obtained by method II were 100.1% for Mg and 102.4% for Zn of those by the direct method. Thus, the indirect method with 2 mol/L HNO3 lysing solution provides a reproducible, reliable, accurate, and simple technique for measuring Mg and Zn in erythrocytes.

  8. Directly Measuring the Degree of Quantum Coherence using Interference Fringes

    NASA Astrophysics Data System (ADS)

    Wang, Yi-Tao; Tang, Jian-Shun; Wei, Zhi-Yuan; Yu, Shang; Ke, Zhi-Jin; Xu, Xiao-Ye; Li, Chuan-Feng; Guo, Guang-Can

    2017-01-01

    Quantum coherence is the most distinguished feature of quantum mechanics. It lies at the heart of the quantum-information technologies as the fundamental resource and is also related to other quantum resources, including entanglement. It plays a critical role in various fields, even in biology. Nevertheless, the rigorous and systematic resource-theoretic framework of coherence has just been developed recently, and several coherence measures are proposed. Experimentally, the usual method to measure coherence is to perform state tomography and use mathematical expressions. Here, we alternatively develop a method to measure coherence directly using its most essential behavior—the interference fringes. The ancilla states are mixed into the target state with various ratios, and the minimal ratio that makes the interference fringes of the "mixed state" vanish is taken as the quantity of coherence. We also use the witness observable to witness coherence, and the optimal witness constitutes another direct method to measure coherence. For comparison, we perform tomography and calculate l1 norm of coherence, which coincides with the results of the other two methods in our situation. Our methods are explicit and robust, providing a nice alternative to the tomographic technique.

  9. Direct measurements of astrophysically important α-induced reactions

    NASA Astrophysics Data System (ADS)

    Avila, Melina

    2016-03-01

    Understanding stellar evolution is one of the primary objectives of nuclear astrophysics. Reaction rates involving α-particles are often key nuclear physics inputs in stellar models. For instance, there are numerous (α , p) reactions fundamental for the understanding of X-ray bursts and the production of 44Ti in core-collapse supernovae. Furthermore, some (α , n) reactions are considered as one of the main neutron sources in the s-process. However, direct measurements of these reactions at relevant astrophysical energies are experimentally challenging because of their small cross section and intensity limitation of radioactive beams. The active target system MUSIC offers a unique opportunity to study (α , p) and (α , n) reactions because its segmented anode allows the investigation of a large energy range in the excitation function with a single measurement. Recent results on the direct measurement of (α , n) and (α , p) measurements in the MUSIC detector will be discussed. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract Number DE-AC02-06CH11357. This research used resources of ANL's ATLAS facility, which is a DOE Office of Science User.

  10. Fast, greener and scalable direct coupling of organolithium compounds with no additional solvents

    PubMed Central

    Pinxterhuis, Erik B.; Giannerini, Massimo; Hornillos, Valentín; Feringa, Ben L.

    2016-01-01

    Although the use of catalytic rather than stoichiometric amounts of metal mediator in cross-coupling reactions between organic halides and organometallic counterparts improves significantly the atom economy and waste production, the use of solvents and stoichiometric generation of main-group byproducts (B, Sn and Zn) hamper the ‘greenness' and industrial efficiency of these processes. Here we present a highly selective and green Pd-catalysed cross-coupling between organic halides and organolithium reagents proceeding without additional solvents and with short reaction times (10 min). This method bypasses a number of challenges previously encountered in Pd-catalysed cross-coupling with organolithium compounds such as strict exclusion of moisture, dilution and slow addition. Operational ease of this protocol combines the use of industrially viable catalysts loadings (down to 0.1 mol%), scalability of the process (tested up to 120 mmol) and exceptionally favourable environmental impact (E factors in several cases as low as 1). PMID:27251636

  11. Engineering Neurospora crassa for cellobionate production directly from cellulose without any enzyme addition.

    PubMed

    Lin, Hui; Hildebrand, Amanda; Kasuga, Takao; Fan, Zhiliang

    2017-04-01

    In a cellulosic biorefinery, the cellulase enzymes needed for hydrolysis are one of the major contributors to high processing costs, while the hydrolysis product, cellobiose, has strong inhibition to the cellulases. In this study, we report engineering recombinant Neurospora crassa strains which are able to produce cellobionate, an organic acid, from cellulose without any enzyme addition. Recombinant strains were constructed by heterologously expressing laccase genes from different sources under different promoters in N. crassa F5Δmus-51Δace-1Δcre-1ΔndvB which has six out of seven β-glucosidase (bgl), two transcription factor (cre1 and ace-1), and the cellobionate phosphorylase (ndvB) genes deleted. The strain expressing laccase from Botrytis aclada under a copper metallothionein promoter (HL10) produced the highest laccase activity. N. crassa HL10 produced 47.4mM cellobionate from cellulose without any enzyme addition. The yield of cellobionate from hydrolyzed cellulose was about 94.5%. Conversion of cellobiose to cellobionate improved cellulose conversion and increases product yield. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Nitrate removal in stream ecosystems measured by 15N addition experiments: Total uptake

    SciTech Connect

    Mulholland, Patrick J; Hall, Robert; Tank, Jennifer; Sobota, Daniel; O'Brien, Jon; Webster, Jackson; Valett, H. Maurice; Dodds, Walter; Poole, Geoff; Peterson, Chris G.; Meyer, Judy; McDowell, William; Johnson, Sherri; Hamilton, Stephen; Gregory, Stanley; Grimm, Nancy; Dahm, Cliff; Cooper, Lee W; Ashkenas, Linda; Thomas, Suzanne; Sheibley, Rich; Potter, Jody; Niederlehner, Bobbie; Johnson, Laura; Helton, Ashley; Crenshaw, Chelsea; Burgin, Amy; Bernot, Melody; Beaulieu, Jake; Arango, Clay

    2009-01-01

    We measured uptake length of {sup 15}NO{sub 3}{sup -} in 72 streams in eight regions across the United States and Puerto Rico to develop quantitative predictive models on controls of NO{sub 3}{sup -} uptake length. As part of the Lotic Intersite Nitrogen Experiment II project, we chose nine streams in each region corresponding to natural (reference), suburban-urban, and agricultural land uses. Study streams spanned a range of human land use to maximize variation in NO{sub 3}{sup -} concentration, geomorphology, and metabolism. We tested a causal model predicting controls on NO{sub 3}{sup -} uptake length using structural equation modeling. The model included concomitant measurements of ecosystem metabolism, hydraulic parameters, and nitrogen concentration. We compared this structural equation model to multiple regression models which included additional biotic, catchment, and riparian variables. The structural equation model explained 79% of the variation in log uptake length (S{sub Wtot}). Uptake length increased with specific discharge (Q/w) and increasing NO{sub 3}{sup -} concentrations, showing a loss in removal efficiency in streams with high NO{sub 3}{sup -} concentration. Uptake lengths shortened with increasing gross primary production, suggesting autotrophic assimilation dominated NO{sub 3}{sup -} removal. The fraction of catchment area as agriculture and suburban-urban land use weakly predicted NO{sub 3}{sup -} uptake in bivariate regression, and did improve prediction in a set of multiple regression models. Adding land use to the structural equation model showed that land use indirectly affected NO{sub 3}{sup -} uptake lengths via directly increasing both gross primary production and NO{sub 3}{sup -} concentration. Gross primary production shortened S{sub Wtot}, while increasing NO{sub 3}{sup -} lengthened S{sub Wtot} resulting in no net effect of land use on NO{sub 3}{sup -} removal.

  13. Nitrate removal in stream ecosystems measured by 15N addition experiments: Total uptake

    USGS Publications Warehouse

    Hall, R.O.; Tank, J.L.; Sobota, D.J.; Mulholland, P.J.; O'Brien, J. M.; Dodds, W.K.; Webster, J.R.; Valett, H.M.; Poole, G.C.; Peterson, B.J.; Meyer, J.L.; McDowell, W.H.; Johnson, S.L.; Hamilton, S.K.; Grimm, N. B.; Gregory, S.V.; Dahm, Clifford N.; Cooper, L.W.; Ashkenas, L.R.; Thomas, S.M.; Sheibley, R.W.; Potter, J.D.; Niederlehner, B.R.; Johnson, L.T.; Helton, A.M.; Crenshaw, C.M.; Burgin, A.J.; Bernot, M.J.; Beaulieu, J.J.; Arangob, C.P.

    2009-01-01

    We measured uptake length of 15NO-3 in 72 streams in eight regions across the United States and Puerto Rico to develop quantitative predictive models on controls of NO-3 uptake length. As part of the Lotic Intersite Nitrogen eXperiment II project, we chose nine streams in each region corresponding to natural (reference), suburban-urban, and agricultural land uses. Study streams spanned a range of human land use to maximize variation in NO-3 concentration, geomorphology, and metabolism. We tested a causal model predicting controls on NO-3 uptake length using structural equation modeling. The model included concomitant measurements of ecosystem metabolism, hydraulic parameters, and nitrogen concentration. We compared this structural equation model to multiple regression models which included additional biotic, catchment, and riparian variables. The structural equation model explained 79% of the variation in log uptake length (S Wtot). Uptake length increased with specific discharge (Q/w) and increasing NO-3 concentrations, showing a loss in removal efficiency in streams with high NO-3 concentration. Uptake lengths shortened with increasing gross primary production, suggesting autotrophic assimilation dominated NO-3 removal. The fraction of catchment area as agriculture and suburban-urban land use weakly predicted NO-3 uptake in bivariate regression, and did improve prediction in a set of multiple regression models. Adding land use to the structural equation model showed that land use indirectly affected NO-3 uptake lengths via directly increasing both gross primary production and NO-3 concentration. Gross primary production shortened SWtot, while increasing NO-3 lengthened SWtot resulting in no net effect of land use on NO- 3 removal. ?? 2009.

  14. Direct Aerosol Radiative Forcing: Calculations and Measurements from the Tropospheric

    NASA Technical Reports Server (NTRS)

    Russell, P. B.; Hignett, P.; Stowe, L. L.; Livingston, J. M.; Kinne, S.; Wong, J.; Chan, K. Roland (Technical Monitor)

    1997-01-01

    Radiative forcing is defined as the change in the net (downwelling minus upwelling) radiative flux at a given level in the atmosphere. This net flux is the radiative power density available to drive climatic processes in the earth-atmosphere system below that level. Recent research shows that radiative forcing by aerosol particles is a major source of uncertainty in climate predictions. To reduce those uncertainties, TARFOX was designed to determine direct (cloud-free) radiative forcing by the aerosols in one of the world's major industrial pollution plumes--that flowing from the east coast of the US over the Atlantic Ocean. TARFOX measured a variety of aerosol radiative effects (including direct forcing) while simultaneously measuring the chemical, physical, and optical properties of the aerosol particles causing those effects. The resulting data sets permit a wide variety of tests of the consistency, or closure, among the measurements and the models that link them. Because climate predictions use the same or similar model components, closure tests help to assess and reduce prediction uncertainties. In this work we use the TARFOX-determined aerosol, gas, and surface properties to compute radiative forcing for a variety of aerosol episodes, with inadvisable optical depths ranging from 0.07 to 0.6. We calculate forcing by several techniques with varying degrees of sophistication, in part to test the range of applicability of simplified techniques--which are often the only ones feasible in climate predictions by general circulation models (GCMs). We then compare computed forcing to that determined from: (1) Upwelling and downwelling fluxes (0.3-0.7 mm and 0.7-3.0 mm) measured by radiometers on the UK MRF C-130. and (2) Daily average cloud-free absorbed solar and emitted thermal radiative flux at the top of the atmosphere derived from the AVHRR radiometer on the NOAA- 14 satellite. The calculations and measurements all yield aerosol direct radiative forcing in the

  15. Comparison of Direct and Indirect Measures of E-cigarette Risk Perceptions

    PubMed Central

    Wackowski, Olivia A.; Bover Manderski, Michelle T.; Delnevo, Cristine D.

    2015-01-01

    Objectives Risk perception measures of tobacco products relative to cigarettes are commonly used and important to tobacco research given that they may be associated with and predict tobacco use. However, results may differ based on measures used. This study compares direct and indirect approaches to measuring e-cigarette/cigarette risk perceptions. Methods We compared the responses of 519 current smokers on a nationally representative 2014 survey that gauged perceptions of e-cigarettes’ harm relative to cigarettes in two ways: 1) a single-item direct measure of comparative harm and a two-item indirect measure (which measured perceived levels of harm from e-cigarettes and cigarettes independently in two parallel questions). Results We found that 60% of smokers rated e-cigarettes “less harmful” than cigarettes when using a direct comparative risk measure versus 73% when using an indirect measure. Agreement between measure types was fair (Cohen’s Kappa=0.45) and was lower for males, Blacks, older and less educated smokers. Conclusions E-cigarettes were more likely to be rated by smokers as less harmful than cigarettes when using indirect versus direct measures. Additional methodology research into this area is warranted given the importance of risk perceptions to tobacco control interventions, communications, policy-making and regulation. PMID:26855966

  16. Directional pattern measurement of the BRAMS beacon antenna system

    NASA Astrophysics Data System (ADS)

    Martínez Picar, A.; Marqué, C.; Anciaux, M.; Lamy, H.

    2015-01-01

    The typical methods for measuring antenna characteristics are mostly based on the use of remote transmitters or receivers. For antennas used in radio communications, calibrations are usually done on an antenna test stand using transmitters with known power output. In order to minimize the ground effects while performing measurements, it is necessary to place the transmitter or receiver high above ground with the aid of aircrafts. It is, however, necessary to determine precisely the coordinates of the airborne devices as well as to maintain high stability. This used to be excessively difficult to carry out, but recent advances in Unmanned Aerial Vehicle (UAV) technologies have brought a feasible option. In this paper, the results of using a low-cost system for measuring the directional pattern of BRAMS beacon antenna system based on an UAV are presented.

  17. Integrating Sphere Microscopy for Direct Absorption Measurements of Single Nanostructures.

    PubMed

    Mann, Sander A; Sciacca, Beniamino; Zhang, Yunyan; Wang, Jia; Kontoleta, Evgenia; Liu, Huiyun; Garnett, Erik C

    2017-02-28

    Nanoscale materials are promising for optoelectronic devices because their physical dimensions are on the order of the wavelength of light. This leads to a variety of complex optical phenomena that, for instance, enhance absorption and emission. However, quantifying the performance of these nanoscale devices frequently requires measuring absolute absorption at the nanoscale, and remarkably, there is no general method capable of doing so directly. Here, we present such a method based on an integrating sphere but modified to achieve submicron spatial resolution. We explore the limits of this technique by using it to measure spatial and spectral absorptance profiles on a wide variety of nanoscale systems, including different combinations of weakly and strongly absorbing and scattering nanomaterials (Si and GaAs nanowires, Au nanoparticles). This measurement technique provides quantitative information about local optical properties that are crucial for improving any optoelectronic device with nanoscale dimensions or nanoscale surface texturing.

  18. Integrating Sphere Microscopy for Direct Absorption Measurements of Single Nanostructures

    PubMed Central

    2017-01-01

    Nanoscale materials are promising for optoelectronic devices because their physical dimensions are on the order of the wavelength of light. This leads to a variety of complex optical phenomena that, for instance, enhance absorption and emission. However, quantifying the performance of these nanoscale devices frequently requires measuring absolute absorption at the nanoscale, and remarkably, there is no general method capable of doing so directly. Here, we present such a method based on an integrating sphere but modified to achieve submicron spatial resolution. We explore the limits of this technique by using it to measure spatial and spectral absorptance profiles on a wide variety of nanoscale systems, including different combinations of weakly and strongly absorbing and scattering nanomaterials (Si and GaAs nanowires, Au nanoparticles). This measurement technique provides quantitative information about local optical properties that are crucial for improving any optoelectronic device with nanoscale dimensions or nanoscale surface texturing. PMID:28056171

  19. Dopexamine has no additional benefit in high-risk patients receiving goal-directed fluid therapy undergoing major abdominal surgery.

    PubMed

    Davies, Simon J; Yates, David; Wilson, R Jonathan T

    2011-01-01

    versus 47% in the dopexamine group (P = 0.14). There was no significant reduction in morbidity on any measured postoperative day. Complication rates, mortality, and hospital length of stay were similar between the 2 groups; however, administration of dopexamine was associated with earlier return of tolerating an enteral diet. With the effective use of goal-directed fluid therapy in elective surgical patients, the routine use of dopexamine does not confer an additional clinical benefit.

  20. Directed self-assembly of PS-b-PMMA with ionic liquid addition

    NASA Astrophysics Data System (ADS)

    Chen, Xuanxuan; Seo, Takehito; Rincon-Delgadillo, Paulina; Matsumiya, Tasuku; Kawaue, Akiya; Maehashi, Takaya; Gronheid, Roel; Nealey, Paul F.

    2016-03-01

    Directed self-assembly of block copolymers is a promising candidate to address grand challenges towards new generations of low-cost, high-resolution nanopatterning technology. Over the past decade, poly(styrene-b-methyl methacrylate) (PS-b-PMMA) has been the most popular block copolymer applied in this area. However, further scaling towards pitches below 20 nm is hindered by its relatively low segregation strength between constituent blocks, characterized by a low Flory-Huggins interaction parameter, χ (~ 0.038 at r.t). To reach sub-10 nm feature dimensions, many high- χ block copolymer materials and processes are currently being studied. Here we investigate the DSA of PSb- PMMA with blended ionic liquid (IL) on chemically-patterned substrates via thermal annealing with a free surface. In this materials system, by adding low volume fraction of IL, a substantially higher χ than the pure block copolymer is achieved with manageable change in surface and interfacial properties so that poly(styrene-random-methyl methacrylate) brushes may be used to control substrate wetting behavior, and the blend could be assembled using thermal annealing with a free surface. In other words, PS-b-PMMA/IL may serve as a high- χ drop-in replacement for PS-b-PMMA. In this work, we provide key DSA results to determine if PS-b-PMMA/IL blends would offer a solution for sub-10 nm lithography.

  1. Sodium borohydride as an additive to enhance the performance of direct ethanol fuel cells

    NASA Astrophysics Data System (ADS)

    Wang, Lianqin; Bambagioni, Valentina; Bevilacqua, Manuela; Bianchini, Claudio; Filippi, Jonathan; Lavacchi, Alessandro; Marchionni, Andrea; Vizza, Francesco; Fang, Xiang; Shen, Pei Kang

    The effect of adding small quantities (0.1-1 wt.%) of sodium borohydride (NaBH 4) to the anolyte solution of direct ethanol fuel cells (DEFCs) with membrane-electrode assemblies constituted by nanosized Pd/C anode, Fe-Co cathode and anion-exchange membrane (Tokuyama A006) was investigated by means of various techniques. These include cyclic voltammetry, in situ FTIR spectroelectrochemistry, a study of the performance of monoplanar fuel cells and an analysis of the ethanol oxidation products. A comparison with fuel cells fed with aqueous solutions of ethanol proved unambiguously the existence of a promoting effect of NaBH 4 on the ethanol oxidation. Indeed, the potentiodynamic curves of the ethanol-NaBH 4 mixtures showed higher power and current densities, accompanied by a remarkable increase in the fuel consumption at comparable working time of the cell. A 13C and 11B { 1H}NMR analysis of the cell exhausts and an in situ FTIR spectroelectrochemical study showed that ethanol is converted selectively to acetate while the oxidation product of NaBH 4 is sodium metaborate (NaBO 2). The enhancement of the overall cell performance has been explained in terms of the ability of NaBH 4 to reduce the PdO layer on the catalyst surface.

  2. Atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry of friction modifier additives analyzed directly from base oil solutions.

    PubMed

    Widder, Lukas; Brennerb, Josef; Huttera, Herbert

    2014-01-01

    To develop new products and to apply measures of quality control quick and simple accessibility of additive composition in automo- tive lubrication is important. The aim of this study was to investigate the possibility of analyzing organic friction modifier additives by means of atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry [AP-MALDI-MS] from lubricant solu- tions without the use of additional separation techniques. Analyses of selected friction modifier ethoxylated tallow amines and oleic acid amide were compared using two ionization methods, positive-ion electrospray ionization (ESI) and AP-MALDI, using a LTQ Orbitrap mass spectrometer. Pure additives were characterized from solvent solutions, as well as from synthetic and mineral base oil mixtures. Detected ions of pure additive samples consisted mainly of [M + H]+, but also alkaLi metal adducts [M + Na]+ and [M + K]+ could be seen. Characterizations of blends of both friction modifiers from the base oil mixtures were carried out as well and showed significant inten- sities for several additive peaks. Thus, this work shows a method to directly analyze friction modifier additives used in the automotive industry from an oil blend via the use of AP-MALDI without any further separation steps. The method presented will further simplify the acquisition of data on lubricant composition and additives. Furthermore, it allows the perspective of analyzing additive reaction products directly from formulated oil blends.

  3. On-board Direct Eddy Flux Measurements of Heat, Water Vapor and Co2

    NASA Astrophysics Data System (ADS)

    Tsukamoto, O.; Takahashi, S.; Kono, T.; Yamashita, E.; Ishida, H.

    Direct eddy fluxes of heat(sensible and latent), water vapor and CO2 were measuted with on-board eddy flux system over the Pacific. Present authors are continueing direct eddy flux measurement on R/V MIRAI(JAMSTEC) cruising the Pacific. I addition to these routine heat flux evaluation, direct CO2 flux measurements were applied with LI- 7500 (Licor) and Kaijo sonic anemometer. The eddy flux system including CO2 sensor worked very well even in the moving ship. Small amplitude of turbulent fluctuations of CO2 were measured and it is found that CO2 was transported downward to sea surface during a month(Nov-Dec 2001) around 2N,138E. CO2 concentrations in the air and sea water were also measured and they also confirmed the CO2 sink. The automated real-time eddy flux system including ship motion correction has started and this can be applied to other cruising ships.

  4. Pyrrolidinyl-sulfamide derivatives as a new class of bifunctional organocatalysts for direct asymmetric Michael addition of cyclohexanone to nitroalkenes.

    PubMed

    Chen, Jia-Rong; Fu, Liang; Zou, You-Quan; Chang, Ning-Jie; Rong, Jian; Xiao, Wen-Jing

    2011-07-21

    A series of chiral pyrrolidinyl-sulfamide derivatives have been identified as efficient bifunctional organocatalysts for the direct Michael addition of cyclohexanone to a wide range of nitroalkenes. The desired Michael adducts were obtained in high chemical yields and excellent stereoselectivities (up to 99/1 dr and 95% ee).

  5. Measuring directional urban spatial interaction in China: A migration perspective

    PubMed Central

    Li, Fangzhou; Feng, Zhiming; Li, Peng; You, Zhen

    2017-01-01

    The study of urban spatial interaction is closely linked to that of economic geography, urban planning, regional development, and so on. Currently, this topic is generating a great deal of interest among researchers who are striving to find accurate ways to measure urban spatial interaction. Classical spatial interaction models lack theoretical guidance and require complicated parameter-adjusting processes. The radiation model, however, as proposed by Simini et al. with rigorous formula derivation, can simulate directional urban spatial interaction. We applied the radiation model in China to simulate the directional migration number among 337 nationwide research units, comprising 4 municipalities and 333 prefecture-level cities. We then analyzed the overall situation in Chinese cities, the interaction intensity hierarchy, and the prime urban agglomerations from the perspective of migration. This was done to ascertain China’s urban spatial interaction and regional development from 2000 to 2010 to reveal ground realities. PMID:28141853

  6. The direct measurement of structural mass, stiffness and damping properties

    NASA Astrophysics Data System (ADS)

    Lee, H. G.; Dobson, B. J.

    1991-02-01

    A method is described for directly evaluating the spatial properties (i.e., mass, stiffness and damping) of a structure from experimentally measured frequency response data. The resulting structural model can be compared directly with an equivalent finite element idealization. The effects of model reduction, such as the Guyan method, which can be employed to ensure that the experimental and theoretical models contain comparable degrees of freedom, are discussed. It is shown that it is possible to detect regions within the structure at which differences exist between the experimental and theoretical models. Further, it is demonstrated that the resulting experimentally derived models can be used to predict the effects of structural modifications upon the frequency response behaviour of the structure.

  7. Measuring directional urban spatial interaction in China: A migration perspective.

    PubMed

    Li, Fangzhou; Feng, Zhiming; Li, Peng; You, Zhen

    2017-01-01

    The study of urban spatial interaction is closely linked to that of economic geography, urban planning, regional development, and so on. Currently, this topic is generating a great deal of interest among researchers who are striving to find accurate ways to measure urban spatial interaction. Classical spatial interaction models lack theoretical guidance and require complicated parameter-adjusting processes. The radiation model, however, as proposed by Simini et al. with rigorous formula derivation, can simulate directional urban spatial interaction. We applied the radiation model in China to simulate the directional migration number among 337 nationwide research units, comprising 4 municipalities and 333 prefecture-level cities. We then analyzed the overall situation in Chinese cities, the interaction intensity hierarchy, and the prime urban agglomerations from the perspective of migration. This was done to ascertain China's urban spatial interaction and regional development from 2000 to 2010 to reveal ground realities.

  8. Measurement of directional thermal infrared emissivity of vegetation and soils

    SciTech Connect

    Norman, J.M.; Balick, L.K.

    1995-10-01

    A new method has been developed for measuring directional thermal emissivity as a function of view angle for plant canopies and soils using two infrared thermometers each sensitive to a different wavelength band. By calibrating the two infrared thermometers to 0.1C consistency, canopy directional emissivity can be estimated with typical errors less than 0.005 in the 8--14 um wavelength band, depending on clarity of the sky and corrections for CO{sub 2} absorption by the atmosphere. A theoretical justification for the method is developed along with an error analysis. Laboratory measurements were used to develop corrections for CO{sub 2}, absorption and a field calibration method is used to obtain the necessary 0.1C consistency for relatively low cost infrared thermometers. The emissivity of alfalfa (LAI=2.5) and corn (LAI=3.2) was near 0.995 and independent of view angle. Individual corn leaves had an emissivity of 0.97. A wheat (LAI=3.0) canopy had an emissivity of 0.985 at nadir and 0.975 at 75 degree view angle. The canopy emissivity values tend to be higher than values in the literature, and are useful for converting infrared thermometer measurements to kinetic temperature and interpreting satellite thermal observations.

  9. Direct measurement of equilibrium constants for high-affinity hemoglobins.

    PubMed

    Kundu, Suman; Premer, Scott A; Hoy, Julie A; Trent, James T; Hargrove, Mark S

    2003-06-01

    The biological functions of heme proteins are linked to their rate and affinity constants for ligand binding. Kinetic experiments are commonly used to measure equilibrium constants for traditional hemoglobins comprised of pentacoordinate ligand binding sites and simple bimolecular reaction schemes. However, kinetic methods do not always yield reliable equilibrium constants with more complex hemoglobins for which reaction mechanisms are not clearly understood. Furthermore, even where reaction mechanisms are clearly understood, it is very difficult to directly measure equilibrium constants for oxygen and carbon monoxide binding to high-affinity (K(D) < 1 micro M) hemoglobins. This work presents a method for direct measurement of equilibrium constants for high-affinity hemoglobins that utilizes a competition for ligands between the "target" protein and an array of "scavenger" hemoglobins with known affinities. This method is described for oxygen and carbon monoxide binding to two hexacoordinate hemoglobins: rice nonsymbiotic hemoglobin and Synechocystis hemoglobin. Our results demonstrate that although these proteins have different mechanisms for ligand binding, their affinities for oxygen and carbon monoxide are similar. Their large affinity constants for oxygen, 285 and approximately 100 micro M(-1) respectively, indicate that they are not capable of facilitating oxygen transport.

  10. Neutrino Mass Measurement Using a Directed Mono-Energetic Beam

    NASA Astrophysics Data System (ADS)

    Tsifrinovich, Vladimir; Folan, Lorcan

    2015-04-01

    It was shown that a directed mono-energetic neutrino beam can be generated by electron capture beta-decay in a sample with a strong hyperfine field at the radioactive nuclei. We study the conditions required to measure the neutrino rest mass using the recoil force produced by a directed neutrino beam. We consider the displacement of an atomic force microscope cantilever due to such a recoil force. We find the change in the cantilever displacement associated with the non-zero neutrino mass, as a function of nuclear half-life T1 / 2, cantilever spring constant, and temperature. We consider the opportunity to increase the sensitivity of the neutrino mass measurement using averaging of the measurement signal. We show that the optimal time for the signal accumulation is, approximately, 1.8T1 / 2. We compute the optimal signal-to-noise ratio for 119Sb nuclei decaying to 119Sn with a decrease in the nuclear spin from I = 5/2 to I = 3/2, and T1 / 2 = 38.2 hours. Finally, we present the parameters values required for detection of sub-eV neutrino rest mass, and estimate the angular distribution of neutrino radiation as a function of temperature.

  11. Direct object detection from field-of-view multiplexed measurements

    NASA Astrophysics Data System (ADS)

    Shilling, Richard Z.; Muise, Robert R.

    2017-04-01

    A compressive imaging model is proposed that multiplexes segments of the field of view (FOV) onto an infrared focal plane array (FPA). Similar to compound imaging, our model is based on combining pixels from a surface comprising of the different parts of the FOV. We formalize this superposition of pixels in a global multiplexing process reducing the number of detectors required for the FPA. We present an analysis of the signal-to-noise ratio for the full rank and compressive collection paradigms for a target detection and tracking scenario. We then apply automated target detection algorithms directly on the measurement sequence for this multiplexing model. We extend the target training and detection processes for the application directly on the encoded measurements. Optimal measurement codes for this application may imply abandoning the ability to reconstruct the actual scene in favor of reconstructing the locations of interesting objects. We present a simulated case study as well as real data results from a visible FOV multiplexing camera.

  12. Direct Detection Doppler Lidar for Spaceborne Wind Measurement

    NASA Technical Reports Server (NTRS)

    Korb, C. Laurence; Flesia, Cristina

    1999-01-01

    Aerosol and molecular based versions of the double-edge technique can be used for direct detection Doppler lidar spaceborne wind measurement. The edge technique utilizes the edge of a high spectral resolution filter for high accuracy wind measurement using direct detection lidar. The signal is split between an edge filter channel and a broadband energy monitor channel. The energy monitor channel is used for signal normalization. The edge measurement is made as a differential frequency measurement between the outgoing laser signal and the atmospheric backscattered return for each pulse. As a result the measurement is insensitive to laser and edge filter frequency jitter and drift at a level less than a few parts in 10(exp 10). We have developed double edge versions of the edge technique for aerosol and molecular-based lidar measurement of the wind. Aerosol-based wind measurements have been made at Goddard Space Flight Center and molecular-based wind measurements at the University of Geneva. We have demonstrated atmospheric measurements using these techniques for altitudes from 1 to more than 10 km. Measurement accuracies of better than 1.25 m/s have been obtained with integration times from 5 to 30 seconds. The measurements can be scaled to space and agree, within a factor of two, with satellite-based simulations of performance based on Poisson statistics. The theory of the double edge aerosol technique is described by a generalized formulation which substantially extends the capabilities of the edge technique. It uses two edges with opposite slopes located about the laser frequency at approximately the half-width of each edge filter. This doubles the signal change for a given Doppler shift and yields a factor of 1.6 improvement in the measurement accuracy compared to the single edge technique. The use of two high resolution edge filters substantially reduces the effects of Rayleigh scattering on the measurement, as much as order of magnitude, and allows the signal

  13. Directly measured secondhand smoke exposure and COPD health outcomes

    PubMed Central

    Eisner, Mark D; Balmes, John; Yelin, Edward H; Katz, Patricia P; Hammond, S Katherine; Benowitz, Neal; Blanc, Paul D

    2006-01-01

    Background Although personal cigarette smoking is the most important cause and modulator of chronic obstructive pulmonary disease (COPD), secondhand smoke (SHS) exposure could influence the course of the disease. Despite the importance of this question, the impact of SHS exposure on COPD health outcomes remains unknown. Methods We used data from two waves of a population-based multiwave U.S. cohort study of adults with COPD. 77 non-smoking respondents with a diagnosis of COPD completed direct SHS monitoring based on urine cotinine and a personal badge that measures nicotine. We evaluated the longitudinal impact of SHS exposure on validated measures of COPD severity, physical health status, quality of life (QOL), and dyspnea measured at one year follow-up. Results The highest level of SHS exposure, as measured by urine cotinine, was cross-sectionally associated with poorer COPD severity (mean score increment 4.7 pts; 95% CI 0.6 to 8.9) and dyspnea (1.0 pts; 95% CI 0.4 to 1.7) after controlling for covariates. In longitudinal analysis, the highest level of baseline cotinine was associated with worse COPD severity (4.7 points; 95% CI -0.1 to 9.4; p = 0.054), disease-specific QOL (2.9 pts; -0.16 to 5.9; p = 0.063), and dyspnea (0.9 pts; 95% CI 0.2 to 1.6 pts; p < 0.05), although the confidence intervals did not always exclude the no effect level. Conclusion Directly measured SHS exposure appears to adversely influence health outcomes in COPD, independent of personal smoking. Because SHS is a modifiable risk factor, clinicians should assess SHS exposure in their patients and counsel its avoidance. In public health terms, the effects of SHS exposure on this vulnerable subpopulation provide a further rationale for laws prohibiting public smoking. PMID:16756671

  14. Electromagnetic exposure compliance estimation using narrowband directional measurements.

    PubMed

    Stratakis, D; Miaoudakis, A; Xenos, T; Zacharopoulos, V

    2008-01-01

    The increased number of everyday applications that rely on wireless communication has drawn an attention to several concerns on the adverse health effects that prolonged or even short time exposure might have on humans. International organisations and countries have adopted guides and legislation for the public safety. They include reference levels (RLs) regarding field strength electromagnetic quantities. To check for RLs compliance in an environment with multiple transmitters of various types, analytical simulation models may be implemented provided that all the necessary information are available. Since this is not generally the case in the most practical situations, on-site measurements have to be performed. The necessary equipment for measurements of this type usually includes broadband field metres suitable to measure the field strength over the whole bandwidth of the field sensor used. These types of measurements have several drawbacks; to begin with, given that RLs are frequency depended, compliance evaluation can be misleading since no information is available regarding the measured spectrum distribution. Furthermore, in a multi-transmitter environment there is no way of distinguishing the contribution of a specific source to the overall field measured. Of course, this problem can be resolved using narrowband directional receiver antennas, yet there is always the need for a priori knowledge of the polarisation of the incident electromagnetic wave. In this work, the use of measurement schemes of this type is addressed. A method independent to the polarisation of the incident wave is proposed and a way to evaluate a single source contribution to the total field in a multi-transmitter environment and the polarisation of the measured incident wave is presented.

  15. Errors Associated with the Direct Measurement of Radionuclides in Wounds

    SciTech Connect

    Hickman, D P

    2006-03-02

    Work in radiation areas can occasionally result in accidental wounds containing radioactive materials. When a wound is incurred within a radiological area, the presence of radioactivity in the wound needs to be confirmed to determine if additional remedial action needs to be taken. Commonly used radiation area monitoring equipment is poorly suited for measurement of radioactive material buried within the tissue of the wound. The Lawrence Livermore National Laboratory (LLNL) In Vivo Measurement Facility has constructed a portable wound counter that provides sufficient detection of radioactivity in wounds as shown in Fig. 1. The LLNL wound measurement system is specifically designed to measure low energy photons that are emitted from uranium and transuranium radionuclides. The portable wound counting system uses a 2.5cm diameter by 1mm thick NaI(Tl) detector. The detector is connected to a Canberra NaI InSpector{trademark}. The InSpector interfaces with an IBM ThinkPad laptop computer, which operates under Genie 2000 software. The wound counting system is maintained and used at the LLNL In Vivo Measurement Facility. The hardware is designed to be portable and is occasionally deployed to respond to the LLNL Health Services facility or local hospitals for examination of personnel that may have radioactive materials within a wound. The typical detection levels in using the LLNL portable wound counter in a low background area is 0.4 nCi to 0.6 nCi assuming a near zero mass source. This paper documents the systematic errors associated with in vivo measurement of radioactive materials buried within wounds using the LLNL portable wound measurement system. These errors are divided into two basic categories, calibration errors and in vivo wound measurement errors. Within these categories, there are errors associated with particle self-absorption of photons, overlying tissue thickness, source distribution within the wound, and count errors. These errors have been examined and

  16. Direct measurement of correlation functions in a lattice Lorentz gas

    NASA Technical Reports Server (NTRS)

    Binder, P.-M.; Frenkel, D.

    1990-01-01

    Simulations of a two-dimensional ballistic Lorentz gas on a lattice are reported. A moment-propagation technique allows direct measurements of the velocity correlation function and its moments with low relative errors for all times. The predicted 1/t-sq algebraic tails in the velocity correlation function are observed at all studied scatterer densities, unlike what has been reported for continuous systems. In the square lattice a fast oscillation is observed, consistent with the existence of staggered density modes. For the second-rank tensor correlation function, an extremely slow approach to the expected 1/t exp 3 tail is found.

  17. Direct measurement of Vorticella contraction force by micropipette deflection.

    PubMed

    France, Danielle; Tejada, Jonathan; Matsudaira, Paul

    2017-02-01

    The ciliated protozoan Vorticella convallaria is noted for its exceptionally fast adenosine triphosphate-independent cellular contraction, but direct measurements of contractile force have proven difficult given the length scale, speed, and forces involved. We used high-speed video microscopy to image live Vorticella stalled in midcontraction by deflection of an attached micropipette. Stall forces correlate with both distance contracted and the resting stalk length. Estimated isometric forces range from 95 to 177 nanonewtons (nN), or 1.12 nN·μm(-1) of the stalk. Maximum velocity and work are also proportional to distance contracted. These parameters constrain proposed biochemical/physical models of the contractile mechanism.

  18. Direct measurement of the W boson decay width

    NASA Astrophysics Data System (ADS)

    Abazov, V. M.; Abbott, B.; Abdesselam, A.; Abolins, M.; Abramov, V.; Acharya, B. S.; Adams, D. L.; Adams, M.; Ahmed, S. N.; Alexeev, G. D.; Alton, A.; Alves, G. A.; Anderson, E. W.; Arnoud, Y.; Avila, C.; Baarmand, M. M.; Babintsev, V. V.; Babukhadia, L.; Bacon, T. C.; Baden, A.; Baldin, B.; Balm, P. W.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bauer, D.; Bean, A.; Beaudette, F.; Begel, M.; Belyaev, A.; Beri, S. B.; Bernardi, G.; Bertram, I.; Besson, A.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Blazey, G.; Blekman, F.; Blessing, S.; Boehnlein, A.; Bojko, N. I.; Bolton, T. A.; Borcherding, F.; Bos, K.; Bose, T.; Brandt, A.; Breedon, R.; Briskin, G.; Brock, R.; Brooijmans, G.; Bross, A.; Buchholz, D.; Buehler, M.; Buescher, V.; Burtovoi, V. S.; Butler, J. M.; Canelli, F.; Carvalho, W.; Casey, D.; Casilum, Z.; Castilla-Valdez, H.; Chakraborty, D.; Chan, K. M.; Chekulaev, S. V.; Cho, D. K.; Choi, S.; Chopra, S.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Coney, L.; Connolly, B.; Cooper, W. E.; Coppage, D.; Crépé-Renaudin, S.; Cummings, M. A.; Cutts, D.; Davis, G. A.; de, K.; de Jong, S. J.; Demarteau, M.; Demina, R.; Demine, P.; Denisov, D.; Denisov, S. P.; Desai, S.; Diehl, H. T.; Diesburg, M.; Doulas, S.; Ducros, Y.; Dudko, L. V.; Duensing, S.; Duflot, L.; Dugad, S. R.; Duperrin, A.; Dyshkant, A.; Edmunds, D.; Ellison, J.; Eltzroth, J. T.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Estrada, J.; Evans, H.; Evdokimov, V. N.; Fahland, T.; Fein, D.; Ferbel, T.; Filthaut, F.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Fleuret, F.; Fortner, M.; Fox, H.; Frame, K. C.; Fu, S.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Gao, M.; Gavrilov, V.; Genik, R. J.; Genser, K.; Gerber, C. E.; Gershtein, Y.; Gilmartin, R.; Ginther, G.; Gómez, B.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Gounder, K.; Goussiou, A.; Graf, N.; Grannis, P. D.; Green, J. A.; Greenlee, H.; Greenwood, Z. D.; Grinstein, S.; Groer, L.; Grünendahl, S.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, G.; Gutierrez, P.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hall, R. E.; Hansen, S.; Hauptman, J. M.; Hays, C.; Hebert, C.; Hedin, D.; Heinmiller, J. M.; Heinson, A. P.; Heintz, U.; Hildreth, M. D.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Huang, Y.; Iashvili, I.; Illingworth, R.; Ito, A. S.; Jaffré, M.; Jain, S.; Jesik, R.; Johns, K.; Johnson, M.; Jonckheere, A.; Jöstlein, H.; Juste, A.; Kahl, W.; Kahn, S.; Kajfasz, E.; Kalinin, A. M.; Karmanov, D.; Karmgard, D.; Kehoe, R.; Khanov, A.; Kharchilava, A.; Kim, S. K.; Klima, B.; Knuteson, B.; Ko, W.; Kohli, J. M.; Kostritskiy, A. V.; Kotcher, J.; Kothari, B.; Kotwal, A. V.; Kozelov, A. V.; Kozlovsky, E. A.; Krane, J.; Krishnaswamy, M. R.; Krivkova, P.; Krzywdzinski, S.; Kubantsev, M.; Kuleshov, S.; Kulik, Y.; Kunori, S.; Kupco, A.; Kuznetsov, V. E.; Landsberg, G.; Lee, W. M.; Leflat, A.; Leggett, C.; Lehner, F.; Leonidopoulos, C.; Li, J.; Li, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Lucotte, A.; Lueking, L.; Lundstedt, C.; Luo, C.; Maciel, A. K.; Madaras, R. J.; Malyshev, V. L.; Manankov, V.; Mao, H. S.; Marshall, T.; Martin, M. I.; Mayorov, A. A.; McCarthy, R.; McMahon, T.; Melanson, H. L.; Merkin, M.; Merritt, K. W.; Miao, C.; Miettinen, H.; Mihalcea, D.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Moore, R. W.; Mostafa, M.; da Motta, H.; Mutaf, Y.; Nagy, E.; Nang, F.; Narain, M.; Narasimham, V. S.; Naumann, N. A.; Neal, H. A.; Negret, J. P.; Nomerotski, A.; Nunnemann, T.; O'Neil, D.; Oguri, V.; Olivier, B.; Oshima, N.; Padley, P.; Pan, L. J.; Papageorgiou, K.; Parashar, N.; Partridge, R.; Parua, N.; Paterno, M.; Patwa, A.; Pawlik, B.; Peters, O.; Pétroff, P.; Piegaia, R.; Pope, B. G.; Popkov, E.; Prosper, H. B.; Protopopescu, S.; Przybycien, M. B.; Qian, J.; Raja, R.; Rajagopalan, S.; Ramberg, E.; Rapidis, P. A.; Reay, N. W.; Reucroft, S.; Ridel, M.; Rijssenbeek, M.; Rizatdinova, F.; Rockwell, T.; Roco, M.; Royon, C.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Sabirov, B. M.; Sajot, G.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Schwartzman, A.; Sen, N.; Shabalina, E.; Shivpuri, R. K.; Shpakov, D.; Shupe, M.; Sidwell, R. A.; Simak, V.; Singh, H.; Sirotenko, V.; Slattery, P.; Smith, E.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Song, Y.; Sorín, V.; Sosebee, M.; Sotnikova, N.; Soustruznik, K.; Souza, M.; Stanton, N. R.; Steinbrück, G.; Stephens, R. W.; Stoker, D.; Stolin, V.; Stone, A.; Stoyanova, D. A.; Strang, M. A.; Strauss, M.; Strovink, M.; Stutte, L.; Sznajder, A.; Talby, M.; Taylor, W.; Tentindo-Repond, S.; Tripathi, S. M.; Trippe, T. G.; Turcot, A. S.; Tuts, P. M.; Vaniev, V.; van Kooten, R.; Varelas, N.; Vertogradov, L. S.; Villeneuve-Seguier, F.; Volkov, A. A.; Vorobiev, A. P.; Wahl, H. D.; Wang, H.; Wang, Z.-M.; Warchol, J.; Watts, G.; Wayne, M.; Weerts, H.; White, A.; White, J. T.; Whiteson, D.; Wijngaarden, D. A.; Willis, S.; Wimpenny, S. J.; Womersley, J.; Wood, D. R.; Xu, Q.; Yamada, R.; Yamin, P.; Yasuda, T.; Yatsunenko, Y. A.; Yip, K.; Youssef, S.; Yu, J.; Zanabria, M.; Zhang, X.; Zheng, H.; Zhou, B.; Zhou, Z.; Zielinski, M.; Zieminska, D.; Zieminski, A.; Zutshi, V.; Zverev, E. G.; Zylberstejn, A.

    2002-08-01

    Based on 85 pb-1 data of pp¯ collisions at (s)=1.8 TeV collected using the DØ detector at Fermilab during the 1994-1995 run of the Tevatron, we present a direct measurement of the total decay width of the W boson ΓW. The width is determined from the transverse mass spectrum in the W-->e+νe decay channel and found to be ΓW=2.23+0.15- 0.14(stat)+/-0.10(syst) GeV, consistent with the expectation from the standard model.

  19. Intertemporal consumption with directly measured welfare functions and subjective expectations

    PubMed Central

    Kapteyn, Arie; Kleinjans, Kristin J.; van Soest, Arthur

    2010-01-01

    Euler equation estimation of intertemporal consumption models requires many, often unverifiable assumptions. These include assumptions on expectations and preferences. We aim at reducing some of these requirements by using direct subjective information on respondents’ preferences and expectations. The results suggest that individually measured welfare functions and expectations have predictive power for the variation in consumption across households. Furthermore, estimates of the intertemporal elasticity of substitution based on the estimated welfare functions are plausible and of a similar order of magnitude as other estimates found in the literature. The model favored by the data only requires cross-section data for estimation. PMID:20442798

  20. Direct Measurement of Intermediate-Range Casimir-Polder Potentials

    SciTech Connect

    Bender, H.; Courteille, Ph. W.; Marzok, C.; Zimmermann, C.; Slama, S.

    2010-02-26

    We present the first direct measurements of Casimir-Polder forces between solid surfaces and atomic gases in the transition regime between the electrostatic short-distance and the retarded long-distance limit. The experimental method is based on ultracold ground-state Rb atoms that are reflected from evanescent wave barriers at the surface of a dielectric glass prism. Our novel approach does not require assumptions about the potential shape. The experimental data are compared to the theoretical predictions valid in the different regimes. They agree best with a full QED calculation.

  1. Determination fo the Rydberg constant by direct frequency measurement

    SciTech Connect

    Nez, F.; Plimmer, M.D.; Bourzeix, S.

    1994-12-31

    We have performed a pure frequency measurement of the 2S-8S/D two photon transition in atomic hydrogen, without any interferometry. The hydrogen frequencies are compared with the difference of two optical standards, the methane stabilized He-Ne laser and the iodine stabilized He-Ne laser. In this way, an optical frequency of atomic hydrogen is directly linked for the first time to the cesium clock. We deduce a new value for the Rydberg constant with an uncertainty of 2.2 parts in 10{sup 11}. This value is currently the most precise available.

  2. Directed energy deflection laboratory measurements of common space based targets

    NASA Astrophysics Data System (ADS)

    Brashears, Travis; Lubin, Philip; Hughes, Gary B.; Meinhold, Peter; Batliner, Payton; Motta, Caio; Madajian, Jonathan; Mercer, Whitaker; Knowles, Patrick

    2016-09-01

    We report on laboratory studies of the effectiveness of directed energy planetary defense as a part of the DE-STAR (Directed Energy System for Targeting of Asteroids and exploRation) program. DE-STAR and DE-STARLITE are directed energy "stand-off" and "stand-on" programs, respectively. These systems consist of a modular array of kilowatt-class lasers powered by photovoltaics, and are capable of heating a spot on the surface of an asteroid to the point of vaporization. Mass ejection, as a plume of evaporated material, creates a reactionary thrust capable of diverting the asteroid's orbit. In a series of papers, we have developed a theoretical basis and described numerical simulations for determining the thrust produced by material evaporating from the surface of an asteroid. In the DESTAR concept, the asteroid itself is used as the deflection "propellant". This study presents results of experiments designed to measure the thrust created by evaporation from a laser directed energy spot. We constructed a vacuum chamber to simulate space conditions, and installed a torsion balance that holds a common space target sample. The sample is illuminated with a fiber array laser with flux levels up to 60 MW/m2 , which allows us to simulate a mission level flux but on a small scale. We use a separate laser as well as a position sensitive centroid detector to readout the angular motion of the torsion balance and can thus determine the thrust. We compare the measured thrust to the models. Our theoretical models indicate a coupling coefficient well in excess of 100 μN/Woptical, though we assume a more conservative value of 80 μN/Woptical and then degrade this with an optical "encircled energy" efficiency of 0.75 to 60 μN/Woptical in our deflection modeling. Our measurements discussed here yield about 45 μN/Wabsorbed as a reasonable lower limit to the thrust per optical watt absorbed. Results vary depending on the material tested and are limited to measurements of 1 axis, so

  3. Laser frequency locking by direct measurement of detuning

    NASA Astrophysics Data System (ADS)

    Ratnapala, A.; Vale, C. J.; White, A. G.; Harvey, M. D.; Heckenberg, N. R.; Rubinsztein-Dunlop, H.

    2004-12-01

    We present a new method of laser frequency locking in which the feedback signal is directly proportional to the detuning from an atomic transition, even at detunings many times the natural linewidth of the transition. Our method is a form of sub-Doppler polarization spectroscopy, based on measuring two Stokes parameters (I2 and I3) of light transmitted through a vapor cell. It extends the linear capture range of the lock loop by as much as an order of magnitude and provides frequency discrimination equivalent to or better than those of other commonly used locking techniques.

  4. GMTI Direction of Arrival Measurements from Multiple Phase Centers.

    SciTech Connect

    Doerry, Armin W.; Bickel, Douglas L.

    2015-03-01

    Ground Moving Target Indicator (GMTI) radar attempts to detect and locate targets with unknown motion. Very slow-moving targets are difficult to locate in the presence of surrounding clutter. This necessitates multiple antenna phase centers (or equivalent) to offer independent Direction of Arrival (DOA) measurements. DOA accuracy and precision generally remains dependent on target Signal-to-Noise Ratio (SNR), Clutter-toNoise Ratio (CNR), scene topography, interfering signals, and a number of antenna parameters. This is true even for adaptive techniques like Space-Time-AdaptiveProcessing (STAP) algorithms.

  5. Direct measurement of the enthalpy of fusion of diopside

    SciTech Connect

    Ziegler, D.; Navrotsky, A.

    1986-11-01

    Crystalline diopside, CaMgSi/sub 2/O/sub 6/, was dropped directly into a Setaram HT1500 calorimeter operating at high temperature. At 1575 < T < 1624 K, the heat content of the crystals was in excellent agreement with previously published results. Above 1634 K, a rise in the enthalpy was seen, supporting the incongruent melting reported by Kushiro. The total enthalpy of fusion at 1665 K, the nominal melting point, is 138.5 kJ/mol, in excellent agreement with measurements which used a cycle that involves dropping the liquid to form a glass and measuring heats of solution of glass and crystals. The heat content of a glassy diopside starting material was also measured. Because the calorimetric experiment lasts only about 8 minutes, these measurements could be extended into the supercooled liquid range (to 1170 K) before the onset of rapid crystallization. A change in slope in the measured heat contents gives a glass transition temperature of 9333 K, about 70 K lower than that reported by other methods. A linear fit of all the data above T/sub g/ (supercooled liquid at 970 to 1170 K, stable liquid at 1668 to 1766 K) gives an average heat capacity for the liquid of 332.8 J/mol/ x K, comparable to the value of 334.6 J/mol x K reported by Richet and Bottinga.

  6. Organocatalytic enantioselective direct additions of aldehydes to 4-vinylpyridines and electron-deficient vinylarenes and their synthetic applications.

    PubMed

    Wang, Sinan; Li, Xiangmin; Liu, Hongwei; Xu, Li; Zhuang, Jinchen; Li, Jian; Li, Hao; Wang, Wei

    2015-02-18

    We describe a synergistic catalysis strategy for the asymmetric direct addition of simple aldehydes to 4-vinylpyridines. By means of independent activation of weakly electrophilic 4-vinylpyridines by the Brønsted acid CF3SO3H (TfOH) and aldehydes by chiral diphenylprolinol tert-butyldimethylsilyl (TBDMS) ether-catalyzed formation of nucleophilic enamines in a cooperative manner, the previously unattainable highly enantioselective addition process has been realized for the first time. Notably, the power of the addition process is fueled by its high efficiency in the production of synthetically valued chiral pyridines. (1)H NMR studies of the process suggested that the nucleophilic enamine formed in situ from the chiral amine catalyst and the aldehyde is directly added to the trimeric 4-vinylpyridinium-derived species as a highly active electrophile generated from the 4-vinylpyridine in the presence of TfOH. Moreover, inspired by the similar electronic natures of pyridine and nitrobenzene, we have achieved an unprecedented chiral diphenylprolinol TBDMS ether-promoted, highly enantioselective direct addition of aldehydes to 2-nitrostyrenes without the use of TfOH as a cocatalyst. In this approach, introducing a strong electron-withdrawing group such as NO2, CF3, SO2Me, etc. on the 2-nitrostyrene creates a highly electrophilic vinyl moiety, which enables the direct addition of the in situ-formed enamine derived from the chiral amine promoter and the aldehyde. This method significantly expands the scope of the enantioselective addition process. While the electron-withdrawing nitro group is essential for activation of the vinyl group, we have demonstrated that it can be readily transformed to diverse functionalities. Furthermore, as shown, a chiral pyridine adduct serves as a key building block in the synthesis of the potent fibrinogen receptor antagonist L-734,217.

  7. Analysis of error-prone survival data under additive hazards models: measurement error effects and adjustments.

    PubMed

    Yan, Ying; Yi, Grace Y

    2016-07-01

    Covariate measurement error occurs commonly in survival analysis. Under the proportional hazards model, measurement error effects have been well studied, and various inference methods have been developed to correct for error effects under such a model. In contrast, error-contaminated survival data under the additive hazards model have received relatively less attention. In this paper, we investigate this problem by exploring measurement error effects on parameter estimation and the change of the hazard function. New insights of measurement error effects are revealed, as opposed to well-documented results for the Cox proportional hazards model. We propose a class of bias correction estimators that embraces certain existing estimators as special cases. In addition, we exploit the regression calibration method to reduce measurement error effects. Theoretical results for the developed methods are established, and numerical assessments are conducted to illustrate the finite sample performance of our methods.

  8. Direct measurement of torsional properties of single fibers

    NASA Astrophysics Data System (ADS)

    Liu, Dabiao; Peng, Kai; He, Yuming

    2016-11-01

    In order to characterize the torsional behavior of micron-scale specimens, a direct technique is established based on the principle of torsion balance. The technique applies twist to the specimen and balances the resulting torque against a torsion wire of known torsional rigidity. The torsional rigidity of the torsion wire is determined by a torsion pendulum. To measure the rotation of the torsion wire, a sensitive angle detector, comprising a thin cross-beam attached between the torsion wire and the fiber specimen and a laser displacement sensor, is developed. The presented technique permits the measurement of torque in single fibers as low as 10-9 Nm with a reasonable resolution. Using this technique, torsion tests on micro-diameter copper wires, silver wires and carbon fibers were performed. The longitudinal shear modulus and other torsional properties of these samples, such as yielding shear strength, were obtained.

  9. Electric System-wide Measurements: North American Directions

    SciTech Connect

    Widergren, Steven E.; Huang, Zhenyu; Dagle, Jeffery E.

    2007-01-03

    The western interconnected electric system of North America pioneered the concept of system-wide measurements, particularly applied to system dynamic issues. This involved the development and deployment of synchronized, sub-second measurement units and their associated data collection networks. More recently, the United States Department of Energy has collaborated with the North American Electric Reliability Council, electric utilities, reliability coordinators, equipment and software suppliers, and researchers to advance the use phasors in the eastern interconnection of North America. This paper provides an overview of the status of system-wide monitoring in North America, the directions emerging for application of this data to situational awareness and system operations, as well as the institutional changes underway to organize the relevant parties and establish a viable infrastructure to support the information exchange required to fulfill each party’s role.

  10. Quantum analysis of the direct measurement of light waves

    NASA Astrophysics Data System (ADS)

    Saldanha, Pablo L.

    2014-01-01

    In a beautiful experiment performed about a decade ago, Goulielmakis et al (2004 Science 305 1267-69) made a direct measurement of the electric field of light waves. However, they used a laser source to produce the light field, whose quantum state has a null expectation value for the electric field operator, so how was it possible to measure this electric field? Here we present a quantum treatment for the f:2f interferometer used to calibrate the carrier-envelope phase of the light pulses in the experiment. We show how the special nonlinear features of the f:2f interferometer can change the quantum state of the electromagnetic field inside the laser cavity to a state with a definite oscillating electric field, explaining how the ‘classical’ electromagnetic field emerges in the experiment. We discuss that this experiment was, to our knowledge, the first demonstration of an absolute coherent superposition of different photon number states in the optical regime.

  11. Direct Tunneling Delay Time Measurement in an Optical Lattice

    NASA Astrophysics Data System (ADS)

    Fortun, A.; Cabrera-Gutiérrez, C.; Condon, G.; Michon, E.; Billy, J.; Guéry-Odelin, D.

    2016-07-01

    We report on the measurement of the time required for a wave packet to tunnel through the potential barriers of an optical lattice. The experiment is carried out by loading adiabatically a Bose-Einstein condensate into a 1D optical lattice. A sudden displacement of the lattice by a few tens of nanometers excites the micromotion of the dipole mode. We then directly observe in momentum space the splitting of the wave packet at the turning points and measure the delay between the reflected and the tunneled packets for various initial displacements. Using this atomic beam splitter twice, we realize a chain of coherent micron-size Mach-Zehnder interferometers at the exit of which we get essentially a wave packet with a negative momentum, a result opposite to the prediction of classical physics.

  12. Direct Measurement of the Zak phase in Topological Bloch Bands

    NASA Astrophysics Data System (ADS)

    Aidelsburger, Monika; Atala, Marcos; Barreiro, Julio; Abanin, Dmitry; Kitagawa, Takuya; Demler, Eugene; Bloch, Immanuel

    2013-05-01

    Geometric phases that characterize the topological properties of Bloch bands play a fundamental role in the modern band theory of solids. We report on the direct measurement of the geometric phase acquired by cold atoms moving in one-dimensional optical lattices. Using a combination of Bloch oscillations and Ramsey interferometry, we extract the Zak phase--the Berry phase acquired during an adiabatic motion of a particle across the Brillouin zone--which can be viewed as an invariant characterizing the topological properties of the band. For a dimerized optical lattice, which models polyacetylene, we measure a difference of the Zak phase equal to 0.97(2) π for the two possible polyacetylene phases with different dimerization. This indicates that the two dimerized phases belong to different topological classes, such that for a filled band, domain walls have fractional quantum numbers. Our work establishes a new general approach for probing the topological structure of Bloch bands in optical lattices.

  13. A Direct Measurement of the $W$ Decay Width

    SciTech Connect

    Vine, Troy

    2008-08-01

    A direct measurement of the W boson total decay width is presented in proton-antiproton collisions at √s = 1.96 TeV using data collected by the CDF II detector. The measurement is made by fitting a simulated signal to the tail of the transverse mass distribution in the electron and muon decay channels. An integrated luminosity of 350 pb-1 is used, collected between February 2002 and August 2004. Combining the results from the separate decay channels gives the decay width as 2.038 ± 0.072 GeV in agreement with the theoretical prediction of 2.093 ± 0.002 GeV. A system is presented for the management of detector calibrations using a relational database schema. A description of the implementation and monitoring of a procedure to provide general users with a simple interface to the complete set of calibrations is also given.

  14. Additional effects of the cervical length measurement in women with preterm contractions: a systematic review.

    PubMed

    Vis, Jolande Y; Kuin, Rosanna A; Grobman, William A; Mol, Ben Willem J; Bossuyt, Patrick M M; Opmeer, Brent C

    2011-09-01

    Transvaginal cervical length measurement in women with symptoms of preterm labor has been used to decide if treatment is necessary. Cervical length measurement may also have additional effects on patients, such as providing reassurance, although the evidence to support this is unclear. We explored and summarized to what extent additional effects of cervical length measurement in women with threatened preterm labor have been reported in the clinical literature and what the magnitude of these effects was. We performed a systematic review of the literature to identify articles reporting on cervical length measurements in women with symptoms of preterm labor. We assessed whether these articles reported patient outcomes other than preterm delivery. The electronic and hand search resulted in 764 articles, of which 172 met initial criteria for further eligibility assessment. We found 12 articles that reported additional effects of cervical length measurement in symptomatic women, such as the reassurance or the sensory consequences related to the transvaginal procedure. None of the articles quantified such additional effects. There appears to be a gap between the presumed effects of cervical length measurement on patient outcomes, such as patients' reassurance, and the actual assessment of these effects during test evaluations. We suggest that future evaluations of prognostic preterm labor tests include a comprehensive assessment of patient outcomes.

  15. Measuring Broadband IR Irradiance in the Direct Solar Beam (Presentation)

    SciTech Connect

    Reda, I.

    2015-03-01

    Solar and atmospheric science radiometers, e.g. pyranometers, pyrheliometers, and photovoltaic cells are calibrated with traceability to a consensus reference, which is maintained by Absolute Cavity Radiometers (ACRs). The ACR is an open cavity with no window, developed to measure extended broadband direct solar irradiance beyond the ultraviolet and infrared bands below and above 0.2 um and 50 um, respectively. On the other hand, pyranometers and pyrheliometers are developed to measure broadband shortwave irradiance from approximately 0.3 um to 3 um, while the present photovoltaic cells are limited to approximately 0.3 um to 1 um. The broadband mismatch of ACR versus such radiometers causes discrepancy in radiometers' calibration methods that has not been discussed or addressed in the solar and atmospheric science literature. Pyrgeometers are also used for solar and atmospheric science applications and are calibrated with traceability to consensus reference, yet are calibrated during nighttime only, because no consensus reference has yet been established for the daytime longwave irradiance. This poster shows a method to measure the broadband IR irradiance in the direct solar beam from 3 um to 50 um, as a first step that might be used to help develop calibration methods to address the mismatch between broadband ACR and shortwave radiometers, and the lack of a daytime reference for pyrgeometers. The irradiance was measured from sunrise to sunset for 5 days when the sun disk was cloudless; the irradiance varied from approximately 1 Wm-2 to 16 Wm-2 for solar zenith angle from 80 degrees to 16 degrees respectively; estimated uncertainty is 1.5 Wm-2.

  16. Measuring Broadband IR Irradiance in the Direct Solar Beam (Poster)

    SciTech Connect

    Reda, I.; Konings, J.; Xie, Y.; Dooraghi, M.; Sengupta, M.

    2015-03-01

    Solar and atmospheric science radiometers, e.g. pyranometers, pyrheliometers, and photovoltaic cells are calibrated with traceability to a consensus reference, which is maintained by Absolute Cavity Radiometers (ACRs). The ACR is an open cavity with no window, developed to measure extended broadband direct solar irradiance beyond the ultraviolet and infrared bands below and above 0.2 micrometers and 50 micrometers, respectively. On the other hand, pyranometers and pyrheliometers are developed to measure broadband shortwave irradiance from approximately 0.3 micrometers to 3 micrcometers, while the present photovoltaic cells are limited to approximately 0.3 micrometers to 1 micrometers. The broadband mismatch of ACR versus such radiometers causes discrepancy in radiometers' calibration methods that has not been discussed or addressed in the solar and atmospheric science literature. Pyrgeometers are also used for solar and atmospheric science applications and calibrated with traceability to consensus reference, yet calibrated during nighttime only, because no consensus reference has yet been established for the daytime longwave irradiance. This poster shows a method to measure the broadband IR irradiance in the direct solar beam from 3 micrometers to 50 micrometers, as first step that might be used to help develop calibration methods to address the mismatch between broadband ACR and shortwave radiometers, and the lack of a daytime reference for pyrgeometers. The irradiance was measured from sunrise to sunset for 5 days when the sun disk was cloudless; the irradiance varied from approximately 1 Wm-2 to 16 Wm-2 for solar zenith angle from 80 degres to 16 degrees respectively; estimated uncertainty is 1.5 Wm-2.

  17. Directly Measured Heating Rates of a Tropical Subvisible Cirrus Cloud

    NASA Technical Reports Server (NTRS)

    Bucholtz, Anthongy; Hlavka, Dennis L.; McGill, Matthew J.; Schmidt, K. Sebastian; Pilewskie, Peter; Davis, Sean M.; Reid, Elizabeth A.; Walker, Annette L.

    2010-01-01

    We present the first direct measurements of the infrared and solar heating rates of a tropical subvisible cirrus (SVC) cloud sampled off the east coast of Nicaragua on 25 July 2007 by the NASA ER-2 aircraft during the Tropical Composition, Cloud and Climate Coupling Experiment (TC4). On this day a persistent thin cirrus layer, with mostly clear skies underneath, was detected in real time by the cloud lidar on the ER-2, and the aircraft was directed to profile down through the SVC. Measurements of the net broadband infrared irradiance and spectrally integrated solar irradiance above, below, and through the SVC are used to determine the infrared and solar heating rates of the cloud. The lidar measurements show that the variable SVC layer was located between approximately 13 and 15 km. Its midvisible optical depth varied from 0.01 to 0.10 with a mean of 0.034 +/- 0.033. Its depolarization ratio was approximately 0.4, indicative of ice clouds. From the divergence of the measured net irradiances the infrared heating rate of the SVC was determined to be approximately 2.50 - 3.24 K/d and the solar heating rate was found to be negligible. These values are consistent with previous indirect observations of other SVC and with model-generated heating rates of SVC with similar optical depths. This study illustrates the utility and potential of the profiling sampling strategy employed here. A more fully instrumented high-altitude aircraft that also included in situ cloud and aerosol probes would provide a comprehensive data set for characterizing both the radiative and microphysical properties of these ubiquitous tropical clouds

  18. Ocean wave detection and direction measurements with microwave radars

    NASA Technical Reports Server (NTRS)

    Teleki, P. G.; Shuchman, R. A.; Brown, W. E., Jr.; Mcleish, W.; Ross, D.; Mattie, M.

    1978-01-01

    The application of synthetic aperture microwave radar imagery to the measurement of ocean wave direction and wavelength is discussed and an airborne experiment conducted in preparation for the SEASAT-A satellite mission is presented. Models for radar backscattering are examined and it is concluded that the Bragg-Rice model, which represents the ocean surface as a combination of periodic surfaces so that the dominant backscatter matches some portion of the wave spectrum, appears most useful. The experiment was conducted with airborne X-band and L-band synthetic aperture radar (SAR) and data was compared with that obtained from a pitch-and-roll buoy and an instrument package mounted on a sea sled. SAR data was converted to wave spectra and it was found to match data from the buoy, while SAR data on wave direction agrees to within two degrees with the buoy and to within one degree with the sea sled sensors. Wave direction data taken by two real aperture radars is also presented and shown to agree with airborne photographs.

  19. Directed Energy Deflection Laboratory Measurements of Asteroids and Space Debris

    NASA Astrophysics Data System (ADS)

    Brashears, T.; Lubin, P. M.

    2016-12-01

    We report on laboratory studies of the effectiveness of directed energy planetary and space defense as a part of the DE-STAR (Directed Energy System for Targeting of Asteroids and exploRation) program. DE-STAR [1][5][6] and DE-STARLITE [2][5][6] are directed energy "stand-off" and "stand-on" programs, respectively. These systems consist of a modular array of kilowatt-class lasers powered by photovoltaics, and are capable of heating a spot on the surface of an asteroid to the point of vaporization. Mass ejection, as a plume of evaporated material, creates a reactionary thrust capable of diverting the asteroid's orbit. In a series of papers, we have developed a theoretical basis and described numerical simulations for determining the thrust produced by material evaporating from the surface of an asteroid [1][2][3][4][5][6]. In the DE-STAR concept, the asteroid itself is used as the deflection "propellant". This study presents results of experiments designed to measure the thrust created by evaporation from a laser directed energy spot. We constructed a vacuum chamber to simulate space conditions, and installed a torsion balance that holds an "asteroid" or a space debris sample. The sample is illuminated with a fiber array laser with flux levels up to 60 MW/m2 which allows us to simulate a mission level flux but on a small scale. We use a separate laser as well as a position sensitive centroid detector to readout the angular motion of the torsion balance and can thus determine the thrust. We compare the measured thrust to the models. Our theoretical models indicate a coupling coefficient well in excess of 100 µN/Woptical, though we assume a more conservative value of 80 µN/Woptical and then degrade this with an optical "encircled energy" efficiency of 0.75 to 60 µN/Woptical in our deflection modeling. Our measurements discussed here yield about 60 µN/Wabsorbed as a reasonable lower limit to the thrust per optical watt absorbed.

  20. Direct Wind Measurements in Io’s Atmosphere

    NASA Astrophysics Data System (ADS)

    Nowling, Michelle; Moullet, Arielle

    2014-11-01

    Io's atmosphere, which is mainly composed of SO2 along with other minor species, is known to present a highly heterogeneous spatial distribution. Ionian atmospheric dynamic models argue that winds are expected to flow from high-density to low-density regions, which, in the context of a sublimation-sustained atmosphere, would correspond to a wind pattern flowing outward from the sub-solar point. Until now, only one direct wind measurement was available, and was at odds with the model predictions. With the Atacama Large Millimeter Array (ALMA), observations were taken with a spatial resolution of 0.86”, 0.46”, allowing one to resolve Io's disk 1.15"). ALMA, located in Chili on the Chajnantor plateau, is the world's most sensitive (sub) millimeter interferometer thanks to its large collective area and its high altitude and dry site. Two observations of a strong SO2 transition were taken one Io day apart. Doppler-shift mapping was performed on the SO2 emission line to measure the line-of-sight projected winds on the leading hemisphere. Our main conclusion is that the global wind pattern, with projected winds moving from the eastern limb to the western, does not match the models. Once Io’s rotational velocity is accounted for, the derived wind velocities are relatively small compared to the previous direct wind observation.

  1. Direct Wind Measurements in Io’s Atmosphere

    NASA Astrophysics Data System (ADS)

    Nowling, Michelle; Moullet, Arielle

    2015-01-01

    Io's atmosphere, which is mainly composed of SO2 along with other minor species, is known to present a highly heterogeneous spatial distribution. Ionian atmospheric dynamic models argue that winds are expected to flow from high-density to low-density regions, which, in the context of a sublimation-sustained atmosphere, would correspond to a wind pattern flowing outward from the sub-solar point. Until now, only one direct wind measurement was available, and was at odds with the model predictions. With the Atacama Large Millimeter Array (ALMA), observations were taken with a spatial resolution of 0.86', 0.46', allowing one to resolve Io's disk (~1.15"). ALMA, located in Chili on the Chajnantor plateau, is the world's most sensitive (sub) millimeter interferometer thanks to its large collective area and its high altitude and dry site. Two observations of a strong SO2 transition were taken one Io day apart. Doppler-shift mapping was performed on the SO2 emission line to measure the line-of-sight projected winds on the leading hemisphere. Our main conclusion is that the global wind pattern, with projectedwinds moving from the eastern limb to the western, does not match the models. Once Io's rotational velocity is accounted for, the derived wind velocities are relatively small compared to the previous direct wind observation.

  2. A review of direct neck measurement in occupational settings.

    PubMed

    Carnaz, Letícia; Batistao, Mariana V; Coury, Helenice J C Gil

    2010-01-01

    No guidelines are available to orient researchers on the availability and applications of equipment and sensors for recording precise neck movements in occupational settings. In this study reports on direct measurements of neck movements in the workplace were reviewed. Using relevant keywords two independent reviewers searched for eligible studies in the following databases: Cinahal, Cochrane, Embase, Lilacs, PubMed, MEDLINE, PEDro, Scopus and Web of Science. After applying the inclusion criteria, 13 articles on direct neck measurements in occupational settings were retrieved from among 33,666 initial titles. These studies were then methodologically evaluated according to their design characteristics, exposure and outcome assessment, and statistical analysis. The results showed that in most of the studies the three axes of neck movement (flexion-extension, lateral flexion and rotation) were not simultaneously recorded. Deficiencies in available equipment explain this flaw, demonstrating that sensors and systems need to be improved so that a true understanding of real occupational exposure can be achieved. Further studies are also needed to assess neck movement in those who perform heavy-duty work, such as nurses and electricians, since no report about such jobs was identified.

  3. Direction-finding measurements of auroral kilometric radiation

    NASA Technical Reports Server (NTRS)

    Kurth, W. S.; Baumback, M. M.; Gurnett, D. A.

    1975-01-01

    Direction-finding measurements with plasma wave experiments on the Hawkeye 1 and Imp 8 satellites are used to locate the source region of auroral kilometric radiation. This radiation has peak intensities between about 100 and 300 kHz and is emitted in intense sporadic bursts lasting for from half an hour to several hours. At peak intensity the total power emitted in this frequency range exceeds 1 billion W. The occurrence of this radiation is known to be closely associated with bright auroral arcs which occur in the local evening auroral regions. Hawkeye 1 provides direction-finding measurements of kilometric radiation from observations at high latitudes over the northern polar regions, and Imp 8 provides similar observations at large radial distances near the equatorial plane. Results from both satellites place the source of the intense auroral kilometric rdiation in the late local evening at about 22.0 hours LT and at a distance of about 0.75 earth radii from the polar axis of the earth.

  4. Development of a new instrument for direct skin friction measurements

    NASA Technical Reports Server (NTRS)

    Vakili, A. D.; Wu, J. M.

    1986-01-01

    A device developed for the direct measurement of wall shear stress generated by flows is described. Simple and symmetric in design with optional small moving mass and no internal friction, the features employed in the design eliminate most of the difficulties associated with the traditional floating element balances. The device is basically small and can be made in various sizes. Vibration problems associated with the floating element skin friction balances were found to be minimized due to the design symmetry and optional damping provided. The design eliminates or reduces the errors associated with conventional floating element devices: such as errors due to gaps, pressure gradient, acceleration, heat transfer, and temperature change. The instrument is equipped with various sensing systems and the output signal is a linear function of the wall shear stress. Dynamic measurements could be made in a limited range and measurements in liquids could be performed readily. Measurement made in the three different tunnels show excellent agreement with data obtained by the floating element devices and other techniques.

  5. Direct measurements of methane emissions from grazing and feedlot cattle.

    PubMed

    Harper, L A; Denmead, O T; Freney, J R; Byers, F M

    1999-06-01

    Methane (CH4) emissions from animals represent a significant contribution to anthropogenically produced radiatively active trace gases. Global and national CH4 budgets currently use predictive models based on emission data from laboratory experiments to estimate the magnitude of the animal source. This paper presents a method for measuring CH4 from animals under undisturbed field conditions and examines the performance of common models used to simulate field conditions. A micrometeorological mass difference technique was developed to measure CH4 production by cattle in pasture and feedlot conditions. Measurements were made continuously under field conditions, semiautomatically for several days, and the technique was virtually nonintrusive. The method permits a relatively large number of cattle to be sampled. Limitations include light winds (less than approximately 2 m/s), rapid wind direction changes, and high-precision CH4 gas concentration measurement. Methane production showed a marked periodicity, with greater emissions during periods of rumination as opposed to grazing. When the cattle were grazed on pasture, they produced .23 kg CH4 x animal(-1) x d(-1), which corresponded to the conversion of 7.7 to 8.4% of gross energy into CH4. When the same cattle were fed a highly digestible, high-grain diet, they produced .07 kg CH4 x animal(-1) x d(-1), corresponding to a conversion of only 1.9 to 2.2% of the feed energy to CH4. These measurements clearly document higher CH4 production (about four times) for cattle receiving low-quality, high-fiber diets than for cattle fed high-grain diets. The mass difference method provides a useful tool for "undisturbed" measurements on the influence of feedstuffs and nutritional management practices on CH4 production from animals and for developing improved management practice for enhanced environmental quality.

  6. Direct and converse measurements of electrostriction in low permittivity dielectrics

    NASA Astrophysics Data System (ADS)

    Yimnirun, Rattikorn

    Electrostriction is the basic electromechanical coupling mechanism in all insulators. For most low permittivity dielectrics, the electrostrictive effects are extremely small, and are often obscured by other phenomena, making them difficult to measure. This study presents electrostriction measurements on low permittivity single crystals, ceramics, glasses, glass- ceramics, and polymers by two independent techniques. A single-beam interferometer with the capability of resolving 10-4 Å in the field- induced displacement was used for the direct coefficient measurements. For the converse technique, a dynamic compressometer was constructed to measure stress-induced changes in capacitance as small as 10-17 F. Problems associated with the measurements, along with procedures designed to eliminate or minimize these problems were discussed. To obtain the true electrostrictive coefficients, Maxwell stress and thermal stress corrections are required for the direct method, while a stress-induced geometric correction must be accounted for in the converse measurement. These corrections are found to be very significant in low permittivity dielectrics. Nevertheless, the results from the two methods are, with a few exceptions, in fairly good agreement. This study presents for the first time the electrostrictive coefficients of several important electronic packaging materials including Al2O 3, BeO, MgO, silica glass, and other engineering glass-ceramics and polymers. Most of the low permittivity dielectrics studied have electrostrictive M coefficients between 10-23 to 10-21 m2/V2, far smaller than the M coefficients of 10-16 m2/V2 in relaxor ferroelectrics and 10-18 m2/V2 in very compliant polymers such as polyurethane. All the materials studied exhibit positive longitudinal coefficients, while the transverse coefficients can be either positive or negative. In units of 10-21 m2/V2, the M11 coefficients of common engineering polymers ranged from +0.4 in polystyrene to +12.7 in

  7. Direct measurement of Lorentz transformation with Doppler effects

    NASA Astrophysics Data System (ADS)

    Chen, Shao-Guang

    For space science and astronomy the fundamentality of one-way velocity of light (OWVL) is selfevident. The measurement of OWVL (distance/interval) and the clock synchronization with light-signal transfer make a logical circulation. This means that OWVL could not be directly measured but only come indirectly from astronomical method (Romer's Io eclipse and Bradley's sidereal aberration), furthermore, the light-year by definitional OWVL and the trigonometry distance with AU are also un-measurable. For to solve this problem two methods of clock synchronization were proposed: The direct method is that at one end of dual-speed transmissionline with single clock measure the arriving-time difference of longitudinal wave and transverse wave or ordinary light and extraordinary light, again to calculate the collective sending-time of two wave with Yang's /shear elastic-modulus ratio (E/k) or extraordinary/ordinary light refractive-index ratio (ne/no), which work as one earthquake-station with single clock measures first-shake time and the distance to epicenter; The indirect method is that the one-way wavelength l is measured by dual-counters Ca and Cb and computer's real-time operation of reading difference (Nb - Na) of two counters, the frequency f is also simultaneously measured, then l f is just OWVL. Therefore, with classical Newtonian mechanics and ether wave optics, OWVL can be measured in the Galileo coordinate system with an isotropic length unit (1889 international meter definition). Without any hypotheses special relativity can entirely establish on the metrical results. When a certain wavelength l is defined as length unit, foregoing measurement of one-way wavelength l will become as the measurement of rod's length. Let a rigidity-rod connecting Ca and Cb moves relative to lamp-house with velocity v, rod's length L = (Nb - Na) l will change follow v by known Doppler effect, i.e., L(q) =L0 (1+ (v/c) cos q), where L0 is the proper length when v= 0, v• r = v cos q

  8. Direct measurement of the beam deflection angle using the axial B-dot field

    NASA Astrophysics Data System (ADS)

    He, Xiaozhong; Zhang, Kaizhi; Li, Qin

    2011-05-01

    Beam position monitors are an important diagnostics tool for particle accelerator operation and related beam dynamics research. The measurement of the beam deflection angle, or moving direction of a charged particle beam with respect to the beam pipe axis, can provide useful additional information. Beam monitors sensitive to the beam’s azimuthal B-dot field (sometimes referred as B dots) are used to measure the displacement (position) of the beam centroid, as the beam generates a dipole term of the azimuthal magnetic field. Similarly, a dipole term of the axial magnetic field will be generated by the beam moving in a direction not parallel to the axis of the beam pipe. In this paper, a new method using the axial B-dot field is presented to measure the beam deflection angle directly, including the theoretical background. Simulations using the MAFIA numerical code have been performed, demonstrating a good agreement to the new established analytical model.

  9. Analysis of occupational accidents: prevention through the use of additional technical safety measures for machinery.

    PubMed

    Dźwiarek, Marek; Latała, Agata

    2016-01-01

    This article presents an analysis of results of 1035 serious and 341 minor accidents recorded by Poland's National Labour Inspectorate (PIP) in 2005-2011, in view of their prevention by means of additional safety measures applied by machinery users. Since the analysis aimed at formulating principles for the application of technical safety measures, the analysed accidents should bear additional attributes: the type of machine operation, technical safety measures and the type of events causing injuries. The analysis proved that the executed tasks and injury-causing events were closely connected and there was a relation between casualty events and technical safety measures. In the case of tasks consisting of manual feeding and collecting materials, the injuries usually occur because of the rotating motion of tools or crushing due to a closing motion. Numerous accidents also happened in the course of supporting actions, like removing pollutants, correcting material position, cleaning, etc.

  10. Analysis of occupational accidents: prevention through the use of additional technical safety measures for machinery

    PubMed Central

    Dźwiarek, Marek; Latała, Agata

    2016-01-01

    This article presents an analysis of results of 1035 serious and 341 minor accidents recorded by Poland's National Labour Inspectorate (PIP) in 2005–2011, in view of their prevention by means of additional safety measures applied by machinery users. Since the analysis aimed at formulating principles for the application of technical safety measures, the analysed accidents should bear additional attributes: the type of machine operation, technical safety measures and the type of events causing injuries. The analysis proved that the executed tasks and injury-causing events were closely connected and there was a relation between casualty events and technical safety measures. In the case of tasks consisting of manual feeding and collecting materials, the injuries usually occur because of the rotating motion of tools or crushing due to a closing motion. Numerous accidents also happened in the course of supporting actions, like removing pollutants, correcting material position, cleaning, etc. PMID:26652689

  11. Photon Doppler Velocimeter to Measure Entrained Additive Manufactured Bulk Metal Powders in Hot Subsonic and Supersonic Oxygen Gas

    NASA Technical Reports Server (NTRS)

    Tylka, Jonathan

    2016-01-01

    Parts produced by additive manufacturing, particularly selective laser melting (SLM), have been shown to silt metal particulate even after undergoing stringent precision aerospace cleaning processes (Lowrey 2016). As printed parts are used in oxygen systems with increased pressures, temperatures, and gas velocity, the risk of ignition by particle impact, the most common direct ignition source of metals in oxygen, substantially increases. The White Sands Test Facility (WSTF), in collaboration with Marshall Space Flight Center (MSFC), desires to test the ignitability of SLM metals by particle impact in heated oxygen. The existing test systems rely on gas velocity calculations to infer particle velocity in both subsonic and supersonic particle impact systems. Until now, it was not possible to directly measure particle velocity. To increase the fidelity of planned SLM ignition studies, it is necessary to validate that the Photon Doppler Velocimetry(PDV) test system can accurately measure particle velocity.

  12. The Development of a Palladium-Catalyzed Tandem Addition/Cyclization for Direct Construction of Indole Skeletons.

    PubMed

    Yu, Shuling; Qi, Linjun; Hu, Kun; Gong, Julin; Cheng, Tianxing; Wang, Qingzong; Chen, Jiuxi; Wu, Huayue

    2017-03-13

    A palladium-catalyzed tandem addition/cyclization of 2-(2-aminoaryl)acetonitriles with arylboronic acids has been developed for the first time, achieving a new strategy for direct construction of indole skeletons. This system shows good functional group tolerance and remarkable chemoselectivity. Especially, the halogen (e.g. bromo and iodo) substituents are amenable for further synthetic elaborations thereby broadening the diversity of the products. Preliminary mechanistic experiments indicate that this transformation involves sequential nucleophilic addition followed by an intramolecular cyclization.

  13. A flexoelectricity effect-based sensor for direct torque measurement

    NASA Astrophysics Data System (ADS)

    Zhang, Shuwen; Xu, Minglong; Liu, Kaiyuan; Shen, Shengping

    2015-12-01

    In this study, a direct torque sensor based on the flexoelectricity generated by un-polarized polyvinylidene fluoride (PVDF) via electromechanical coupling is developed as a novel torque measurement mechanism that does not require external electric power excitation. The sensing method is developed based on the shear strain gradient and the shear flexoelectric response of PVDF. A theoretical analysis is primarily presented for the design of the sensing structure. Then the structure of the PVDF sensing module is discussed and designed. The radius ratio of the sensing module is defined and then discussed according to the load, the strain gradient, the electrode area and the general electric charge output. The finite element method is used to analyze the mechanical properties of the designed PVDF sensing module. Then the theoretical sensitivity of the sensor is predicated as 0.9441 pC Nm-1. The experiment system setup is developed, and the sensing properties of the measurement mechanism are tested at frequencies of 0.5 Hz, 1 Hz, 1.5 Hz and 2 Hz using identical modules. The measurement range of the designed sensor is 0-1.68 Nm and the average sensitivity is measured as 0.8950 pC Nm-1. The experimental results agree well with the theoretically predicted results. These results prove that the torque sensing method based on un-polarized PVDF is suitable for measurement of dynamic torque loads with a flexoelectricity-based mechanism. When using this method, external electric power excitation of the sensing module is no longer required.

  14. Gravitational spectra from direct measurements. [of surface field

    NASA Technical Reports Server (NTRS)

    Wagner, C. A.; Colombo, O. L.

    1979-01-01

    A simple rapid method is described for determining the spectrum of a surface field (in spherical harmonics) from harmonic analysis of direct (in situ) measurements along great circle arcs. The method is shown to give excellent overall trends (smoothed spectra) to very high degree from even a few short arcs of satellite data. Three examples are taken with perfect measurements of satellite tracking over a planet made up of hundreds of point masses using (1) altimetric heights from a low-orbiting spacecraft, (2) velocity (range rate) residuals between a low and a high satellite in circular orbits, and (3) range rate data between a station at infinity and a satellite in a highly eccentric orbit. In particular, the smoothed spectrum of the earth's gravitational field is determined to about degree 400(50-km half wavelength) from 1 x 1 deg gravimetry and the equivalent of 11 revolutions of GEOS 3 and Skylab altimetry. This measurement shows that there is about 46 cm of geoid height (rms worldwide) remaining in the field beyond degree 180.

  15. Impact of plasma noise on a direct thrust measurement system.

    PubMed

    Pottinger, S J; Lamprou, D; Knoll, A K; Lappas, V J

    2012-03-01

    In order to evaluate the accuracy and sensitivity of a pendulum-type thrust measurement system, a linear variable differential transformer (LVDT) and a laser optical displacement sensor have been used simultaneously to determine the displacement resulting from an applied thrust. The LVDT sensor uses an analog interface, whereas the laser sensor uses a digital interface to communicate the displacement readings to the data acquisition equipment. The data collected by both sensors show good agreement for static mass calibrations and validation with a cold gas thruster. However, the data obtained using the LVDT deviate significantly from that of the laser sensor when operating two varieties of plasma thrusters: a radio frequency (RF) driven plasma thruster, and a DC powered plasma thruster. Results establish that even with appropriate shielding and signal filtering the LVDT sensor is subject to plasma noise and radio frequency interactions which result in anomalous thrust readings. Experimental data show that the thrust determined using the LVDT system in a direct current plasma environment and a RF discharge is approximately a factor of three higher than the thrust values obtained using a laser sensor system for the operating conditions investigated. These findings are of significance to the electric propulsion community as LVDT sensors are often utilized in thrust measurement systems and accurate thrust measurement and the reproducibility of thrust data is key to analyzing thruster performance. Methods are proposed to evaluate system susceptibility to plasma noise and an effective filtering scheme presented for DC discharges.

  16. Direct Measurement of Macromolecule-Coated Colloid-Mucus Interactions.

    PubMed

    Swavola, Julia C; Edwards, Tara D; Bevan, Michael A

    2015-08-25

    We report measurements of macromolecule-coated colloids interacting with mucus to understand colloidal particle diffusion near mucus-coated surfaces. Total internal reflection microscopy is used to measure colloids with adsorbed poly(ethylene glycol) (PEG), bovine serum albumin (BSA), and polyelectrolyte bilayers (PEB) interacting with mucus to obtain kT-scale energy landscapes and nanometer-scale diffusivity landscapes. Energy landscapes are quantified as a superposition of van der Waals, steric, and tethering potentials, and diffusivity landscapes are modeled by considering lubrication in the presence of permeable layers. PEG- and BSA-coated colloids have soft repulsion with mucus that could enable diffusion of small particles within mucus pores. PEB-coated colloids display attractive tethers to mucus that produce irreversible binding. Different interaction potentials for each particle coating confirm that the ζ-potential is not a successful predictor of particle-mucus interactions and diffusion. Diffusivity landscapes show thick mucus layers are permeable to the solvent and dominate particle-mucus hydrodynamic interactions relative to the thin, impermeable particle coatings. Our results show direct measurements and models to understand how particle coating properties (e.g., elasticity, porosity) control particle interactions and transport near mucus films to potentially aid the design of better particle-based therapeutics and diagnostics.

  17. Directional correlation measurements for gamma transitions in /sup 127/Te

    SciTech Connect

    de Souza, M.O.M.D.; Saxena, R.N.

    1985-02-01

    The directional correlation of coincident ..gamma.. transitions in /sup 127/Te has been measured following the ..beta../sup -/ decay of /sup 127/Sb (T/sub 1/2/ = 3.9 d) using Ge(Li)-Ge(Li) and Ge(Li)-NaI(T1) gamma spectrometers. Measurements have been carried out for 14 gamma cascades resulting in the determination of multipole mixing ratios delta(E2/M1) for 15 ..gamma.. transitions. The present results permitted a definite spin assignment of (7/2) for the 785 keV level and confirmation of several previous assignments to other levels in /sup 127/Te. The g factor of the 340 keV ((9/2)/sup -/) level has also been measured using the integral perturbed angular correlation method in the hyperfine magnetic field of a Te in Ni matrix. The results of the g factor as well as the mixing ratio for the 252 keV ((9/2)/sup -/..-->..(11/2)/sup -/) transition support the earlier interpretation of this state as an anomalous coupling state.

  18. Direct measurement of friction of a fluctuating contact line

    NASA Astrophysics Data System (ADS)

    Guo, Shuo; Gao, Min; Xiong, Xiaomin; Wang, Yong Jian; Wang, Xiaoping; Sheng, Ping; Tong, Penger

    2013-03-01

    What happens at a moving contact line, where one fluid displaces another (immiscible) fluid over a solid surface, is a fundamental issue in fluid dynamics. In this presentation, we report a direct measurement of the friction coefficient in the immediate vicinity of a fluctuating contact line using a micron-sized vertical glass fiber with one end glued to an atomic force microscope (AFM) cantilever beam and the other end touching a liquid-air interface. By measuring the broadening of the resonance peak of the cantilever system with varying liquid viscosity η, we obtain the friction coefficient ξc associated with the contact line fluctuations on the glass fiber of diameter d and find it has the universal form, ξc = 0 . 8 πdη , independent of the contact angle. The result is further confirmed by using a soap film system whose bulk effect is negligibly small. This is the first time that the friction coefficient of a fluctuating contact line is measured. *Work supported by the Research Grants Council of Hong Kong SAR.

  19. Direct mass measurements of the heaviest elements with Penning traps

    NASA Astrophysics Data System (ADS)

    Block, M.

    2015-12-01

    Penning-trap mass spectrometry (PTMS) is a mature technique to provide atomic masses with highest precision. Applied to radionuclides it enables us to investigate their nuclear structure via binding energies and derived quantities such as nucleon separation energies. Recent progress in slowing down radioactive ion beams in buffer gas cells in combination with advanced ion-manipulation techniques has opened the door to access even the elements above fermium by PTMS. Such elements are produced in complete fusion-evaporation reactions of heavy ions with lead, bismuth, and actinide targets at very low rates. Pioneering high-precision mass measurements of nobelium and lawrencium isotopes have been performed with SHIPTRAP at the GSI Darmstadt, Germany. These have illustrated that direct mass measurements provide reliable anchor points to pin down decay chains and that they allow mapping nuclear shell effects, the reason for the very existence of the heaviest elements. Thus, accurate masses contribute to our understanding of these exotic nuclei with extreme proton numbers. In this article experimental challenges in mass measurements of the heaviest elements with Penning traps are discussed. Some illustrative examples of the nuclear structure features displayed based on the presently known masses are given.

  20. Direct measurement of the anelasticity of a tungsten fiber

    NASA Astrophysics Data System (ADS)

    Yang, Shan-Qing; Tu, Liang-Cheng; Shao, Cheng-Gang; Li, Qing; Wang, Qing-Lan; Zhou, Ze-Bing; Luo, Jun

    2009-12-01

    We report the first precision measurement of the frequency-dependent property of the effective torsion spring constant for a tungsten fiber by using two disk pendulums with different moments of inertia. A quartz fiber with Q≈3.36×105 was used to determine the ratio of the moments of inertia of two pendulums. The experimental result indicated that the torsion spring constant of the tungsten fiber was dependent on the oscillation frequency by ΔK/Δ(ω2)=(0.954±0.084)×10-8kgm2 at ˜mHz range, which suggested that the resultant bias in our G measurement with the time-of-swing method was ΔG/G=(211.80±18.69)ppm as reported recently by Jun Luo et al. [Phys. Rev. Lett. 102, 240801 (2009)PRLTAO0031-900710.1103/PhysRevLett.102.240801]. This experiment provided the first direct test to the Kuroda-Newman effect that predicted an upward bias in a G measurement with the time-of-swing method.

  1. Impact of plasma noise on a direct thrust measurement system

    NASA Astrophysics Data System (ADS)

    Pottinger, S. J.; Lamprou, D.; Knoll, A. K.; Lappas, V. J.

    2012-03-01

    In order to evaluate the accuracy and sensitivity of a pendulum-type thrust measurement system, a linear variable differential transformer (LVDT) and a laser optical displacement sensor have been used simultaneously to determine the displacement resulting from an applied thrust. The LVDT sensor uses an analog interface, whereas the laser sensor uses a digital interface to communicate the displacement readings to the data acquisition equipment. The data collected by both sensors show good agreement for static mass calibrations and validation with a cold gas thruster. However, the data obtained using the LVDT deviate significantly from that of the laser sensor when operating two varieties of plasma thrusters: a radio frequency (RF) driven plasma thruster, and a DC powered plasma thruster. Results establish that even with appropriate shielding and signal filtering the LVDT sensor is subject to plasma noise and radio frequency interactions which result in anomalous thrust readings. Experimental data show that the thrust determined using the LVDT system in a direct current plasma environment and a RF discharge is approximately a factor of three higher than the thrust values obtained using a laser sensor system for the operating conditions investigated. These findings are of significance to the electric propulsion community as LVDT sensors are often utilized in thrust measurement systems and accurate thrust measurement and the reproducibility of thrust data is key to analyzing thruster performance. Methods are proposed to evaluate system susceptibility to plasma noise and an effective filtering scheme presented for DC discharges.

  2. Discoveries from Revisiting Apollo Direct Active Measurements of Lunar Dust

    NASA Astrophysics Data System (ADS)

    O'Brien, Brian

    2010-05-01

    New missions to the moon being developed by China, Japan, India, USA, Russia and Europe and possibilities of human missions about 2020 face the reality that 6 Apollo expeditions did not totally manage or mitigate effects of easily-mobilised and very "sticky" lunar dust on humans and hardware. Laboratory and theoretical modelling cannot reliably simulate the complex lunar environments that affect dynamical movements of lunar dust. The only direct active measurements of lunar dust during Apollo were made by matchbox-sized minimalist Dust Detector Experiments (DDEs) deployed to transmit some 30 million digital measurements from Apollo 11, 12, 14 and 15. These were misplaced or relatively ignored until 2009, when a self-funded suite of discoveries (O'Brien Geophys. Research Letters FIX 6 May 2099) revealed unexpected properties of lunar dust, such as the adhesive force being stronger as illumination increased. We give the first reports of contrasting effects, contamination or cleansing, from rocket exhausts of Apollo 11, 12, 14 and 15 Lunar Modules leaving the moon. We further strengthen the importance of collateral dust inadvertently splashed on Apollo hardware by human activities. Dust management designs and mission plans require optimum use of such in situ measurements, extended by laboratory simulations and theoretical modelling.

  3. The First Example of Nickel-Catalyzed Silyl-Heck Reactions: Direct Activation of Silyl Triflates Without Iodide Additives

    PubMed Central

    McAtee, Jesse R.; Martin, Sara E. S.; Cinderella, Andrew P.; Reid, William B.; Johnson, Keywan A.

    2014-01-01

    For the first time, nickel-catalyzed silyl-Heck reactions are reported. Using simple phosphine-supported nickel catalysts, direct activation of silyl triflates has been achieved. These results contrast earlier palladium-catalyzed systems, which require iodide additives to activate silyl-triflates. These nickel-based catalysts exhibit good functional group tolerance in the preparation of vinyl silanes, and unlike earlier systems, allows for the incorporation of trialkylsilanes larger than Me3Si. PMID:24914247

  4. 49 CFR 192.935 - What additional preventive and mitigative measures must an operator take?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... accordance with one of the risk assessment approaches in ASME/ANSI B31.8S (incorporated by reference, see § 192.7), section 5, a risk analysis of its pipeline to identify additional measures to protect the high.... (2) Outside force damage. If an operator determines that outside force (e.g., earth movement,...

  5. 49 CFR 192.935 - What additional preventive and mitigative measures must an operator take?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... accordance with one of the risk assessment approaches in ASME/ANSI B31.8S (incorporated by reference, see § 192.7), section 5, a risk analysis of its pipeline to identify additional measures to protect the high.... (2) Outside force damage. If an operator determines that outside force (e.g., earth movement,...

  6. Direct Measurement of Topological Numbers with Spins in Diamond.

    PubMed

    Kong, Fei; Ju, Chenyong; Liu, Ying; Lei, Chao; Wang, Mengqi; Kong, Xi; Wang, Pengfei; Huang, Pu; Li, Zhaokai; Shi, Fazhan; Jiang, Liang; Du, Jiangfeng

    2016-08-05

    Topological numbers can characterize the transition between different topological phases, which are not described by Landau's paradigm of symmetry breaking. Since the discovery of the quantum Hall effect, more topological phases have been theoretically predicted and experimentally verified. However, it is still an experimental challenge to directly measure the topological numbers of various predicted topological phases. In this Letter, we demonstrate quantum simulation of topological phase transition of a quantum wire (QW), by precisely modulating the Hamiltonian of a single nitrogen-vacancy (NV) center in diamond. Deploying a quantum algorithm of finding eigenvalues, we reliably extract both the dispersion relations and topological numbers. This method can be further generalized to simulate more complicated topological systems.

  7. Direct measurement of oxygen stoichiometry in perovskite films

    NASA Astrophysics Data System (ADS)

    Scola, J.; Benamar, A.; Berini, B.; Jomard, F.; Dumont, Y.

    2017-02-01

    We present a direct method to measure the oxygen stoichiometry in an oxide film with an accuracy of about 2%. It is based on a combination of 18O annealing and high mass resolution secondary ion mass spectroscopy. Calibration has been done on a LaNiO3 film whose electrical properties dependence on oxygen stoichiometry are well documented. The method is illustrated with a series of LaNiO3 films grown on SrTiO3 substrates prepared with different oxygen stoichiometries. The large influence of the surface state on oxygen exchange is evidenced in films grown on different substrate orientations or coated with a thin layer of LaAlO3. Oxygen surface exchange and bulk diffusion is then discussed for both LaNiO3 and SrVO3 films.

  8. Estimating big bluestem albedo from directional reflectance measurements

    NASA Technical Reports Server (NTRS)

    Irons, J. R.; Ranson, K. J.; Daughtry, C. S. T.

    1988-01-01

    Multidirectional reflectance factor measurements acquired in the summer of 1986 are used to make estimates of big bluestem grass albedo, evaluating the variation of albedo with changes in solar zenith angle and phenology. On any given day, the albedo was observed to increase by at least 19 percent as solar zenith angle increased. Changes in albedo were found to correspond to changes in the green leaf area index of the grass canopy. Estimates of albedo made using reflectance data acquired within only one or two azimuthal planes and at a restricted range of view zenith angle were evaluated and compared to 'true' albedos derived from all available reflectance factor data. It was found that even a limited amount of multiple direction reflectance data was preferable to a single nadir reflectance factor for the estimation of prarie grass albedo.

  9. Direct measurement of optical-trap-induced decoherence

    NASA Astrophysics Data System (ADS)

    Matsumoto, Nobuyuki; Komori, Kentaro; Ito, Sosuke; Michimura, Yuta; Aso, Yoichi

    2016-09-01

    Thermal decoherence is a major obstacle to the realization of quantum coherence for massive mechanical oscillators. Although optical trapping has been used to reduce the thermal decoherence rate for such oscillators, it also increases the rate by subjecting the oscillator to stochastic forces resulting from the frequency fluctuations of the optical field, thereby setting a fundamental limit on the reduction. This is analogous to the noise penalty in an active feedback system. Here, we directly measure the rethermalization process for an initially cooled and optically trapped suspended mirror, and identify the current limiting decoherence rate as due to the optical trap. Our experimental study of the trap-induced decoherence rate will enable future advances in the probing of fundamental quantum mechanics in the bad-cavity regime, such as testing of deformed commutators.

  10. Estimating big bluestem albedo from directional reflectance measurements

    NASA Technical Reports Server (NTRS)

    Irons, J. R.; Ranson, K. J.; Daughtry, C. S. T.

    1988-01-01

    Multidirectional reflectance factor measurements acquired in the summer of 1986 are used to make estimates of big bluestem grass albedo, evaluating the variation of albedo with changes in solar zenith angle and phenology. On any given day, the albedo was observed to increase by at least 19 percent as solar zenith angle increased. Changes in albedo were found to correspond to changes in the green leaf area index of the grass canopy. Estimates of albedo made using reflectance data acquired within only one or two azimuthal planes and at a restricted range of view zenith angle were evaluated and compared to 'true' albedos derived from all available reflectance factor data. It was found that even a limited amount of multiple direction reflectance data was preferable to a single nadir reflectance factor for the estimation of prarie grass albedo.

  11. Direct frequency comb measurement of OD + CO → DOCO kinetics.

    PubMed

    Bjork, B J; Bui, T Q; Heckl, O H; Changala, P B; Spaun, B; Heu, P; Follman, D; Deutsch, C; Cole, G D; Aspelmeyer, M; Okumura, M; Ye, J

    2016-10-28

    The kinetics of the hydroxyl radical (OH) + carbon monoxide (CO) reaction, which is fundamental to both atmospheric and combustion chemistry, are complex because of the formation of the hydrocarboxyl radical (HOCO) intermediate. Despite extensive studies of this reaction, HOCO has not been observed under thermal reaction conditions. Exploiting the sensitive, broadband, and high-resolution capabilities of time-resolved cavity-enhanced direct frequency comb spectroscopy, we observed deuteroxyl radical (OD) + CO reaction kinetics and detected stabilized trans-DOCO, the deuterated analog of trans-HOCO. By simultaneously measuring the time-dependent concentrations of the trans-DOCO and OD species, we observed unambiguous low-pressure termolecular dependence of the reaction rate coefficients for N2 and CO bath gases. These results confirm the HOCO formation mechanism and quantify its yield.

  12. Direct measurement of the formation length of photons.

    PubMed

    Andersen, Kristoffer K; Andersen, Søren L; Esberg, Jakob; Knudsen, Helge; Mikkelsen, Rune; Uggerhøj, Ulrik I; Sona, Pietro; Mangiarotti, Alessio; Ketel, Tjeerd J; Ballestrero, Sergio

    2012-02-17

    We report the first observation of a shoulder in the radiation spectrum from GeV electrons in a structured target consisting of two thin and closely spaced foils. The position of the shoulder depends on the target spacing and is directly connected to the finite formation length of a low-energy photon emitted by an ultrarelativistic electron. With the present setup it is possible to control the separation of the foils on a μm scale and hence measure interference effects caused by the macroscopic dimensions of the formation length. Several theoretical groups have predicted this effect using different methods. Our observations have a preference for the modified theory by Blankenbecler but disagree with the results of Baier and Katkov.

  13. Direct electronic measurement of Peltier cooling and heating in graphene.

    PubMed

    Vera-Marun, I J; van den Berg, J J; Dejene, F K; van Wees, B J

    2016-05-10

    Thermoelectric effects allow the generation of electrical power from waste heat and the electrical control of cooling and heating. Remarkably, these effects are also highly sensitive to the asymmetry in the density of states around the Fermi energy and can therefore be exploited as probes of distortions in the electronic structure at the nanoscale. Here we consider two-dimensional graphene as an excellent nanoscale carbon material for exploring the interaction between electronic and thermal transport phenomena, by presenting a direct and quantitative measurement of the Peltier component to electronic cooling and heating in graphene. Thanks to an architecture including nanoscale thermometers, we detected Peltier component modulation of up to 15 mK for currents of 20 μA at room temperature and observed a full reversal between Peltier cooling and heating for electron and hole regimes. This fundamental thermodynamic property is a complementary tool for the study of nanoscale thermoelectric transport in two-dimensional materials.

  14. Direct electronic measurement of Peltier cooling and heating in graphene

    NASA Astrophysics Data System (ADS)

    Vera-Marun, I. J.; van den Berg, J. J.; Dejene, F. K.; van Wees, B. J.

    2016-05-01

    Thermoelectric effects allow the generation of electrical power from waste heat and the electrical control of cooling and heating. Remarkably, these effects are also highly sensitive to the asymmetry in the density of states around the Fermi energy and can therefore be exploited as probes of distortions in the electronic structure at the nanoscale. Here we consider two-dimensional graphene as an excellent nanoscale carbon material for exploring the interaction between electronic and thermal transport phenomena, by presenting a direct and quantitative measurement of the Peltier component to electronic cooling and heating in graphene. Thanks to an architecture including nanoscale thermometers, we detected Peltier component modulation of up to 15 mK for currents of 20 μA at room temperature and observed a full reversal between Peltier cooling and heating for electron and hole regimes. This fundamental thermodynamic property is a complementary tool for the study of nanoscale thermoelectric transport in two-dimensional materials.

  15. Direct electronic measurement of Peltier cooling and heating in graphene

    PubMed Central

    Vera-Marun, I. J.; van den Berg, J. J.; Dejene, F. K.; van Wees, B. J.

    2016-01-01

    Thermoelectric effects allow the generation of electrical power from waste heat and the electrical control of cooling and heating. Remarkably, these effects are also highly sensitive to the asymmetry in the density of states around the Fermi energy and can therefore be exploited as probes of distortions in the electronic structure at the nanoscale. Here we consider two-dimensional graphene as an excellent nanoscale carbon material for exploring the interaction between electronic and thermal transport phenomena, by presenting a direct and quantitative measurement of the Peltier component to electronic cooling and heating in graphene. Thanks to an architecture including nanoscale thermometers, we detected Peltier component modulation of up to 15 mK for currents of 20 μA at room temperature and observed a full reversal between Peltier cooling and heating for electron and hole regimes. This fundamental thermodynamic property is a complementary tool for the study of nanoscale thermoelectric transport in two-dimensional materials. PMID:27161186

  16. Direct micro-mechanical measurements on C. elegans

    NASA Astrophysics Data System (ADS)

    Backholm, Matilda; Ryu, William S.; Dalnoki-Veress, Kari

    2013-03-01

    The millimeter-sized nematode Caenorhabditis elegans provides an excellent biophysical system for both static and dynamic biomechanical studies. The undulatory motion exhibited by this model organism as it crawls or swims through a medium is ubiquitous in nature at scales from microns to meters. A successful description of this form of locomotion requires knowledge of the material properties of the crawler, as well as its force output as it moves. Here we present an experimental technique with which the material properties and dynamics of C. elegans can be directly probed. By using the deflection of a flexible micropipette, the bending stiffness of C. elegans has been measured at all stages of its life cycle, as well as along the body of the adult worm. The mechanical properties of the worm are modelled as a viscoelastic material which provides new insights into its material properties. The forces exerted by the worm during undulatory motion are also discussed. Direct experimental characterization of this model organism provides guidance for theoretical treatments of undulatory locomotion in general.

  17. Direct measurement of salicylphenolic glucuronide in human urine.

    PubMed

    Imhoff, D M; Reece, P A; Dimitriadis, E; Ward, A D; Bochner, F

    1986-01-01

    Indirect measurement of salicylphenolic glucuronide (SPG) has suggested that the formation of this metabolite from therapeutic doses of salicyclic acid (SA) is capacity-limited in humans. A direct high performance liquid chromatographic (HPLC) assay for SPG in human urine is described. SPG was prepared by a published method and purified by HPLC. On treatment with beta-glucuronidase, SPG yielded the expected amount of SA. Spectroscopic data, melting point, and optical rotation of the glucuronide and/or its triacetyl dimethyl ester derivative were consistent with the proposed structure. SPG was assayed using a 5-micron C18 column (temperature 55 degrees C) and fluorescence detection. A nonlinear gradient mobile phase at a flow rate of 2 ml/min was used, beginning with 100% 0.1 M pH 2.1 phosphate buffer and finishing with 84% buffer, 16% acetonitrile. Total run time was 25 min. Urine (10 microliter) was injected directly on the column, and quantitation was performed using urine standards. Within-run precision for SPG ranged from 1.2% at 150 mg/L to 2.4% at 5 mg/L. The limit of detection was less than 1 mg/L. A pilot study in two volunteers, each receiving a single 500-mg dose of sodium salicylate, was carried out to validate the usefulness of the assay.

  18. Direct microsensor measurement of nitric oxide production by the osteoclast.

    PubMed

    Silverton, S F; Adebanjo, O A; Moonga, B S; Awumey, E M; Malinski, T; Zaidi, M

    1999-05-27

    Nitric oxide (NO) triggers marked osteoclast retraction which closely resembles that due to Ca2+. The effect of Ca2+ has been attributed to a stimulated release of NO. Here, we show for the first time, by direct measurement with a microsensor, that osteoclasts do indeed produce NO and that this production is enhanced by a high Ca2+. We also show that the Ca2+ ionophore, A23187, mimics the latter. Furthermore, osteoclasts on dentine produce more NO than osteoclasts on glass and NO release from dentine-plated osteoclasts is much less sensitive to stimulation by Ca2+. Finally, the microsomal Ca2+ store-depleting agent, thapsigargin, attenuates NO release only from osteoclasts on glass, suggesting that stored Ca2+ has the dominant effect in modulating NO release from non-resorbing cells. NO is a powerful inhibitor of bone resorption: a direct demonstration of its production is therefore strong evidence for a role in modulating osteoclast function. Copyright 1999 Academic Press.

  19. Quantitative measurement of direct nitrous oxide emissions from microalgae cultivation.

    PubMed

    Fagerstone, Kelly D; Quinn, Jason C; Bradley, Thomas H; De Long, Susan K; Marchese, Anthony J

    2011-11-01

    Although numerous lifecycle assessments (LCA) of microalgae-based biofuels have suggested net reductions of greenhouse gas emissions, limited experimental data exist on direct emissions from microalgae cultivation systems. For example, nitrous oxide (N(2)O) is a potent greenhouse gas that has been detected from microalgae cultivation. However, little quantitative experimental data exist on direct N(2)O emissions from microalgae cultivation, which has inhibited LCA performed to date. In this study, microalgae species Nannochloropsis salina was cultivated with diurnal light-dark cycling using a nitrate nitrogen source. Gaseous N(2)O emissions were quantitatively measured using Fourier transform infrared spectrometry. Under a nitrogen headspace (photobioreactor simulation), the reactors exhibited elevated N(2)O emissions during dark periods, and reduced N(2)O emissions during light periods. Under air headspace conditions (open pond simulation), N(2)O emissions were negligible during both light and dark periods. Results show that N(2)O production was induced by anoxic conditions when nitrate was present, suggesting that N(2)O was produced by denitrifying bacteria within the culture. The presence of denitrifying bacteria was verified through PCR-based detection of norB genes and antibiotic treatments, the latter of which substantially reduced N(2)O emissions. Application of these results to LCA and strategies for growth management to reduce N(2)O emissions are discussed.

  20. Direct measurement of the upper critical field in cuprate superconductors

    PubMed Central

    Grissonnanche, G.; Cyr-Choinière, O.; Laliberté, F.; René de Cotret, S.; Juneau-Fecteau, A.; Dufour-Beauséjour, S.; Delage, M. -È.; LeBoeuf, D.; Chang, J.; Ramshaw, B. J.; Bonn, D. A.; Hardy, W. N.; Liang, R.; Adachi, S.; Hussey, N. E.; Vignolle, B.; Proust, C.; Sutherland, M.; Krämer, S.; Park, J. -H.; Graf, D.; Doiron-Leyraud, N.; Taillefer, Louis

    2014-01-01

    In the quest to increase the critical temperature Tc of cuprate superconductors, it is essential to identify the factors that limit the strength of superconductivity. The upper critical field Hc2 is a fundamental measure of that strength, yet there is no agreement on its magnitude and doping dependence in cuprate superconductors. Here we show that the thermal conductivity can be used to directly detect Hc2 in the cuprates YBa2Cu3Oy, YBa2Cu4O8 and Tl2Ba2CuO6+δ, allowing us to map out Hc2 across the doping phase diagram. It exhibits two peaks, each located at a critical point where the Fermi surface of YBa2Cu3Oy is known to undergo a transformation. Below the higher critical point, the condensation energy, obtained directly from Hc2, suffers a sudden 20-fold collapse. This reveals that phase competition—associated with Fermi-surface reconstruction and charge-density-wave order—is a key limiting factor in the superconductivity of cuprates. PMID:24518054

  1. [Effects of incorporating additional blood pressure measurements during The National Health Survey in Chile].

    PubMed

    Montero, Joaquín; Mansilla, Cristián; Margozzini, Paula

    2016-03-01

    It is of utmost importance to identify hypertensive subjects in a country, in order to use efficiently public resources. The National Health Survey 2009-10 in Chile incorporated a third measurement of blood pressure (BP) during the home visit performed by a nurse, and a second day of measurement in a representative sub-sample. To study the effect of these two additional actions over both the average value of BP and the national prevalence of hypertension. A third blood pressure measurement was carried out in 5,058 subjects, and it was measured in a second day in 930 individuals. The effect of these additional measurements on absolute blood pressure values and the prevalence of hypertension were assessed. A small but statistically significant reduction in mean systolic pressure (0.52 mmHg) and the prevalence of hypertension (1%) was observed after the incorporation of the third blood pressure measurement. No effects in these figures were observed after the measurement performed on a second day. These findings should be considered when designing the new National Health Survey in Chile.

  2. Review of Measurements of the Aerosol Global Direct Radiative Forcing

    NASA Astrophysics Data System (ADS)

    Anderson, T. L.

    2004-12-01

    Of all the ways that anthropogenic aerosols are suspected of impacting the Earth's energy balance, direct shortwave forcing during clear-sky conditions (DF) is by far the most straightforward to measure and understand. So, how well do we know this quantity? Model-based estimates of DF have treated individual anthropogenic components, but this approach is not practical for global satellite observations, which inherently sense the total aerosol and cannot readily detect chemical composition. In conjunction with members of the "A-Train" science teams, an observational strategy is being developed that attacks the DF problem in terms of three observable parameters: mid-visible aerosol optical depth (AOD), fine-mode fraction of optical depth (FMF) - which is taken as a proxy for anthropogenic fraction - and radiative forcing efficiency per unit optical depth (RFE). This talk will assess knowledge of each parameter. AOD is rather well known, with a long history of observations by multiple satellites and an extensive validation program in place. FMF (deduced from the wavelength dependence of AOD) is routinely reported by satellites, but these data have unknown accuracy, due to the absence of a validation program, and show discontinuities at land/ocean boundaries indicative of artifacts. Many investigators have combined AOD measurements with satellite measurements of broadband flux to estimate RFE over the oceans. These studies suffer from limited coverage (a few percent of the ocean) and a lack of collocated, sub-orbital measurements sufficient to diagnose the causes of RFE variation (such as differences in ambient relative humidity or aerosol single scattering albedo). Covariation among these three parameters has not yet been assessed. Summarizing, the lower limit on uncertainty in DF is about a factor of three and the upper limit is unknown. New and enhanced satellite sensors offer the potential for greatly reduced uncertainty in the near future. However, achieving this

  3. Study raises questions about measurement of 'additionality,'or maintaining domestic health spending amid foreign donations.

    PubMed

    Garg, Charu C; Evans, David B; Dmytraczenko, Tania; Izazola-Licea, José-Antonio; Tangcharoensathien, Viroj; Ejeder, Tessa Tan-Torres

    2012-02-01

    Donor nations and philanthropic organizations increasingly require that funds provided for a specific health priority such as HIV should supplement domestic spending on that priority-a concept known as "additionality." We investigated the "additionality" concept using data from Honduras, Rwanda, and Thailand, and we found that the three countries increased funding for HIV in response to increased donor funding. In contrast, the study revealed that donors, faced with increased Global Fund resources for HIV in certain countries, tended to decrease their funding for HIV or shift funds for use in non-HIV health areas. More broadly, we found many problems in the measurement and interpretation of additionality. These findings suggest that it would be preferable for donors and countries to agree on how best to use available domestic and external funds to improve population health, and to develop better means of tracking outcomes, than to try to develop more sophisticated methods to track additionality.

  4. Calibrated BOLD using direct measurement of changes in venous oxygenation.

    PubMed

    Driver, Ian D; Hall, Emma L; Wharton, Samuel J; Pritchard, Susan E; Francis, Susan T; Gowland, Penny A

    2012-11-15

    Calibration of the BOLD signal is potentially of great value in providing a closer measure of the underlying changes in brain function related to neuronal activity than the BOLD signal alone, but current approaches rely on an assumed relationship between cerebral blood volume (CBV) and cerebral blood flow (CBF). This is poorly characterised in humans and does not reflect the predominantly venous nature of BOLD contrast, whilst this relationship may vary across brain regions and depend on the structure of the local vascular bed. This work demonstrates a new approach to BOLD calibration which does not require an assumption about the relationship between cerebral blood volume and cerebral blood flow. This method involves repeating the same stimulus both at normoxia and hyperoxia, using hyperoxic BOLD contrast to estimate the relative changes in venous blood oxygenation and venous CBV. To do this the effect of hyperoxia on venous blood oxygenation has to be calculated, which requires an estimate of basal oxygen extraction fraction, and this can be estimated from the phase as an alternative to using a literature estimate. Additional measurement of the relative change in CBF, combined with the blood oxygenation change can be used to calculate the relative change in CMRO(2) due to the stimulus. CMRO(2) changes of 18 ± 8% in response to a motor task were measured without requiring the assumption of a CBV/CBF coupling relationship, and are in agreement with previous approaches.

  5. Direct measures of mechanical energy for knife mill size reduction

    SciTech Connect

    Bitra, V.S.P.; Womac, A.R.; Igathinathane, C.; Miu, P.I; Yang, Y.T.; Smith, D.R.; Chevanan, Nehru; Sokhansanj, Shahabaddine

    2009-08-01

    Lengthy straw/stalk of biomass may not be directly fed into grinders such as hammer mills and disc refiners. Hence, biomass needs to be preprocessed using coarse grinders like a knife mill to allow for efficient feeding in refiner mills without bridging and choking. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented knife mill. Direct power inputs were determined for different knife mill screen openings from 12.7 to 50.8 mm, rotor speeds between 250 and 500 rpm, and mass feed rates from 1 to 11 kg/min. Overall accuracy of power measurement was calculated to be 0.003 kW. Total specific energy (kWh/Mg) was defined as size reduction energy to operate mill with biomass. Effective specific energy was defined as the energy that can be assumed to reach the biomass. The difference is parasitic or no-load energy of mill. Total specific energy for switchgrass, wheat straw, and corn stover chopping increased with knife mill speed, whereas, effective specific energy decreased marginally for switchgrass and increased for wheat straw and corn stover. Total and effective specific energy decreased with an increase in screen size for all the crops studied. Total specific energy decreased with increase in mass feed rate, but effective specific energy increased for switchgrass and wheat straw, and decreased for corn stover at increased feed rate. For knife mill screen size of 25.4 mm and optimum speed of 250 rpm, optimum feed rates were 7.6, 5.8, and 4.5 kg/min for switchgrass, wheat straw, and corn stover, respectively, and the corresponding total specific energies were 7.57, 10.53, and 8.87 kWh/Mg and effective specific energies were 1.27, 1.50, and 0.24 kWh/Mg for switchgrass, wheat straw, and corn stover, respectively. Energy utilization ratios were calculated as 16.8%, 14.3%, and 2.8% for switchgrass, wheat straw, and corn stover, respectively. These

  6. Additional atmospheric opacity measurements at lambda = 1.1 mm from Mauna Kea Observatory, Hawaii

    NASA Technical Reports Server (NTRS)

    Parrish, A.; De Zafra, R. L.; Barrett, J. W.; Solomon, P.; Connor, B.

    1987-01-01

    Atmospheric opacity values in the zenith direction are given for a wavelength of 1.1 mm (278 GHz) at the summit of Mauna Kea in the Hawaiian Islands. A total of 75 days is covered during the period 1983-1986. Observations were made on a quasi-continuous basis, with opacity measured every 20 minutes around the clock for significant periods of time. A conversion from opacity at lambda = 1.1 mm to the equivalent precipitable water vapor column is given from the measurements of Zammit and Ade (1981), from which opacities at other wavelengths may be derived.

  7. Direct measurement of polariton-polariton interaction strength

    NASA Astrophysics Data System (ADS)

    Sun, Yongbao; Yoon, Yoseob; Steger, Mark; Liu, Gangqiang; Pfeiffer, Loren N.; West, Ken; Snoke, David W.; Nelson, Keith A.

    2017-09-01

    Exciton-polaritons in a microcavity are composite two-dimensional bosonic quasiparticles, arising from the strong coupling between confined light modes in a resonant planar optical cavity and excitonic transitions. Quantum phenomena such as Bose-Einstein condensation, superfluidity, quantized vortices, and macroscopic quantum states have been realized at temperatures from tens of kelvin up to room temperatures. Crucially, many of these effects of exciton-polaritons depend on the polariton-polariton interaction strength. Despite the importance of this parameter, it has been difficult to make an accurate experimental measurement, mostly because of the difficulty in determining the absolute densities of polaritons and bare excitons. Here we report a direct measurement of the polariton-polariton interaction strength in a very high-Q microcavity structure. By allowing polaritons to propagate over 20 μm to the centre of a laser-generated annular trap, we are able to separate the polariton-polariton interactions from polariton-exciton interactions. The interaction strength is deduced from the energy renormalization of the polariton dispersion as the polariton density is increased, using the polariton condensation as a benchmark for the density. We find that the interaction strength is about two orders of magnitude larger than previous theoretical estimates, putting polaritons in the strongly interacting regime.

  8. Spectroscopic ellipsometer based on direct measurement of polarization ellipticity

    SciTech Connect

    Watkins, Lionel R.

    2011-06-20

    A polarizer-sample-Wollaston prism analyzer ellipsometer is described in which the ellipsometric angles {psi} and {Delta} are determined by direct measurement of the elliptically polarized light reflected from the sample. With the Wollaston prism initially set to transmit p- and s-polarized light, the azimuthal angle P of the polarizer is adjusted until the two beams have equal intensity. This condition yields {psi}={+-}P and ensures that the reflected elliptically polarized light has an azimuthal angle of {+-}45 deg. and maximum ellipticity. Rotating the Wollaston prism through 45 deg. and adjusting the analyzer azimuth until the two beams again have equal intensity yields the ellipticity that allows {Delta} to be determined via a simple linear relationship. The errors produced by nonideal components are analyzed. We show that the polarizer dominates these errors but that for most practical purposes, the error in {psi} is negligible and the error in {Delta} may be corrected exactly. A native oxide layer on a silicon substrate was measured at a single wavelength and multiple angles of incidence and spectroscopically at a single angle of incidence. The best fit film thicknesses obtained were in excellent agreement with those determined using a traditional null ellipsometer.

  9. Direct measurements of bed stress under swash in the field

    NASA Astrophysics Data System (ADS)

    Conley, Daniel C.; Griffin, John G.

    2004-03-01

    Utilizing flush mounted hot film anemometry, the bed stress under swash was measured directly in a field experiment conducted on Barret Beach, Fire Island, New York. The theory, development, and calibration of the instrument package are discussed, and results from the field experiment are presented. Examples of bed stress time series throughout a swash cycle are presented, and an ensemble averaged swash bed stress cycle is calculated. Strong asymmetry is observed between the uprush and backwash phases of the swash flow. The maximum bed shear stress exerted by the uprush is approximately double that of the backwash, while the duration of the backwash is 135% greater than that of the uprush. Friction coefficients in the swash zone are observed to be similar in magnitude to those from steady flow, with the mean observed friction coefficient equal to 0.0037. Swash friction coefficients derived from the current measurements exhibit a Reynolds number dependence similar to that observed for other flows. A systematic difference between coefficients for uprush and backwash is suggested.

  10. Methods of Measuring Vapor Pressures of Lubricants With Their Additives Using TGA and/or Microbalances

    NASA Technical Reports Server (NTRS)

    Scialdone, John J.; Miller, Michael K.; Montoya, Alex F.

    1996-01-01

    The life of a space system may be critically dependent on the lubrication of some of its moving parts. The vapor pressure, the quantity of the available lubricant, the temperature and the exhaust venting conductance passage are important considerations in the selection and application of a lubricant. In addition, the oil additives employed to provide certain properties of low friction, surface tension, antioxidant and load bearing characteristics, are also very important and need to be known with regard to their amounts and vapor pressures. This paper reports on the measurements and analyses carried out to obtain those parameters for two often employed lubricants, the Apiezon(TM)-C and the Krytox(TM) AB. The measurements were made employing an electronic microbalance and a thermogravimetric analyzer (TGA) modified to operate in a vacuum. The results have been compared to other data on these oils when available. The identification of the mass fractions of the additives in the oil and their vapor pressures as a function of the temperature were carried out. These may be used to estimate the lubricant life given its quantity and the system vent exhaust conductance. It was found that the Apiezon(TM)-C has three main components with different rates of evaporation while the Krytox(TM) did not indicate any measurable additive.

  11. Direct and Indirect Measures of Learning Outcomes in an MSW Program: What Do We Actually Measure?

    ERIC Educational Resources Information Center

    Calderon, Orly

    2013-01-01

    This study offers a unique perspective on assessment of learning by comparing results from direct and indirect measures in a social work graduate program across two campuses of a single university. The findings suggest that students' perceptions of learning are not necessarily reflective of content and applied skills mastery. Perception of…

  12. Accurate measurement of psoralen-crosslinked DNA: direct biochemical measurements and indirect measurement by hybridization

    SciTech Connect

    Matsuo, N.; Ross, P.M.

    1988-11-01

    This paper evaluates methods to measure crosslinkage due to psoralen plus light in total DNA and in specific sequences. DNA exposed in cells or in vitro to a bifunctional psoralen and near ultraviolet light accumulates interstrand crosslinks. Crosslinkage is the DNA mass fraction that is attached in both strands to a crosslink. We show here biochemical methods to measure psoralen photocrosslinkage accurately in total DNA. We also describe methods to measure photocrosslinkage indirectly, in specific sequences, by nucleic acid hybridization. We show that a single 4,5',8-trimethylpsoralen (TMP) crosslink causes at least 50 kbp of alkali-denatured DNA contiguous in both strands with it to snap back into the duplex form when the denatured preparation is returned to neutral pH. This process was so efficient that the DNA was not nicked by the single-strand nuclease S1 at 100-fold excess after snapping back. Uncrosslinked DNA was digested to acid-soluble material by the enzyme. Crosslinkage therefore equals the fraction of S1-resistant nucleotide in this kind of experiment. We alkali-denatured DNA samples crosslinked to varying degrees by varying TMP concentration at constant light exposure. We then measured crosslinkage by ethidium bromide (EtBr) fluorometry at pH 11.8; by EtBr fluorometry at neutral pH of S1 digests of the DNA; and by the fraction of radioactivity remaining acid insoluble in S1-digests of DNA labeled uniformly with (3H)deoxythymidine. These assays measure distinct physical properties of crosslinked DNA. Numerical agreement is expected only when all three measurements are accurate. Under optimum conditions, the three methods yielded identical results over the range of measurement. Using alkaline EtBr fluorescence in crude cell lysates, we detected crosslinks at frequencies in the range of 1.6 X 10(-7) per base pair.

  13. Handheld directional reflectometer: an angular imaging device to measure BRDF and HDR in real time

    NASA Astrophysics Data System (ADS)

    Mattison, Phillip R.; Dombrowski, Mark S.; Lorenz, James M.; Davis, Keith J.; Mann, Harley C.; Johnson, Philip; Foos, Bryan

    1998-10-01

    Many applications require quantitative measurements of surface light scattering, including quality control on production lines, inspection of painted surfaces, inspection of field repairs, etc. Instruments for measuring surface scattering typically fall into two main categories, namely bidirectional reflectometers, which measure the angular distribution of scattering, and hemispherical directional reflectometers, which measure the total scattering into the hemisphere above the surface. Measurement of the bi-directional reflectance distribution function (BRDF) gives the greatest insight into how light is scattered from a surface. Measurements of BRDF, however, are typically very lengthy measurements taken by moving a source and detector to map the scattering. Since BRDF has four angular degrees of freedom, such measurements can require hours to days to complete. Instruments for measuring BRDF are also typically laboratory devices, although a field- portable bi-directional reflectometer does exist. Hemispherical directional reflectance (HDR) is a much easier measurement to make, although care must be taken to use the proper methodology when measuring at wavelengths beyond 10 micrometer, since integrating spheres (typically used to make such measurements) are very energy inefficient and lose their integrating properties at very long wavelengths. A few field- portable hemispherical directional reflectometers do exist, but typically measure HDR only at near-normal angles. Boeing Defense and Space Group and Surface Optics Corporation, under a contract from the Air Force Research Laboratory, have developed a new hand-held instrument capable of measuring both BRDF and HDR using a unique, patented angular imaging technique. A combination of an hemi-ellipsoidal mirror and an additional lens translate the angular scatter from a surface into a two-dimensional spatial distribution, which is recorded by an imaging array. This configuration fully maps the scattering from a half

  14. Direct and indirect measures of speech articulator motions using low power EM sensors

    SciTech Connect

    Barnes, T; Burnett, G; Gable, T; Holzrichter, J F; Ng, L

    1999-05-12

    Low power Electromagnetic (EM) Wave sensors can measure general properties of human speech articulator motions, as speech is produced. See Holzrichter, Burnett, Ng, and Lea, J.Acoust.Soc.Am. 103 (1) 622 (1998). Experiments have demonstrated extremely accurate pitch measurements (< 1 Hz per pitch cycle) and accurate onset of voiced speech. Recent measurements of pressure-induced tracheal motions enable very good spectra and amplitude estimates of a voiced excitation function. The use of the measured excitation functions and pitch synchronous processing enable the determination of each pitch cycle of an accurate transfer function and, indirectly, of the corresponding articulator motions. In addition, direct measurements have been made of EM wave reflections from articulator interfaces, including jaw, tongue, and palate, simultaneously with acoustic and glottal open/close signals. While several types of EM sensors are suitable for speech articulator measurements, the homodyne sensor has been found to provide good spatial and temporal resolution for several applications.

  15. Direct costs of bovine spongiform encephalopathy control measures in Germany.

    PubMed

    Probst, C; Gethmann, J M; Heuser, R; Niemann, H; Conraths, F J

    2013-12-01

    On 26 November 2000, the first autochthonous case of bovine spongiform encephalopathy (BSE) was detected in Germany. Since then, a total of 413 BSE cases have been confirmed, resulting in the culling and destruction of 17 313 heads of cattle. In view of the possible risks for human and animal health, Germany has adopted EU regulations along with some additional requirements concerning active surveillance and response measures after detecting a BSE-positive animal. In this study, we used a stochastic model to estimate the costs incurred by the ensuing legislative amendments responding to BSE between November 2000 and December 2010. The total costs were estimated to range between 1847 and 2094 million Euros. They peaked in 2001 (about 394 million Euros) and declined since. About 54% of the costs (approximately 1000 million Euros) were incurred by the extension of the feed ban for animal protein to all farmed livestock. Active surveillance accounted for 21% (405 million Euros), the incineration of animal protein for 13% (249 million Euros) and the removal of specified risk material for 11% (225 million Euros). Only 1% of the costs was related to response measures after detecting a BSE-positive animal, including indemnity payments for culled cattle and confiscated carcasses at the slaughterhouse. © 2013 Blackwell Verlag GmbH.

  16. Relationship between laboratory measures of directional advantage and everyday success with directional microphone hearing aids.

    PubMed

    Cord, Mary T; Surr, Rauna K; Walden, Brian E; Dyrlund, Ole

    2004-05-01

    The improvement in speech recognition in noise obtained with directional microphones compared to omnidirectional microphones is referred to as the directional advantage. Laboratory studies have revealed substantial differences in the magnitude of the directional advantage across hearing-impaired listeners. This investigation examined whether persons who were successful users of directional microphone hearing aids in everyday living tended to obtain a larger directional advantage in the test booth than persons who were unsuccessful users. Results revealed that the mean directional advantage did not differ significantly between patients who used the directional mode regularly and those who reported little or no benefit from directional microphones in daily living and, therefore, tended to leave their hearing aids set in the default omnidirectional mode. Success with directional microphone hearing aids in everyday living, therefore, cannot be reliably predicted by the magnitude of the directional advantage obtained in the clinic.

  17. TOWARD A DIRECT MEASUREMENT OF THE COSMIC ACCELERATION

    SciTech Connect

    Darling, Jeremy

    2012-12-20

    We present precise H I 21 cm absorption line redshifts observed in multiple epochs to directly constrain the secular redshift drift z-dot or the cosmic acceleration, {Delta}v/{Delta}t{sub circle}. A comparison of literature analog spectra to contemporary digital spectra shows significant acceleration likely attributable to systematic instrumental errors. However, we obtain robust constraints using primarily Green Bank Telescope digital data. Ten objects spanning z = 0.09-0.69 observed over 13.5 years show z-dot = (-2.3 {+-} 0.8) Multiplication-Sign 10{sup -8} yr{sup -1} or {Delta}v/{Delta}t{sub circle} = -5.5 {+-} 2.2 m s{sup -1} yr{sup -1}. The best constraint from a single object, 3C 286 at (z) = 0.692153275(85), is z-dot = (1.6 {+-} 4.7) Multiplication-Sign 10{sup -8} yr{sup -1} or {Delta}v/{Delta}t{sub circle} = 2.8 {+-} 8.4 m s{sup -1} yr{sup -1}. These measurements are three orders of magnitude larger than the theoretically expected acceleration at z = 0.5, z-dot = 2 Multiplication-Sign 10{sup -11} yr{sup -1} or {Delta}v/{Delta}t{sub circle} = 0.3 cm s{sup -1} yr{sup -1}, but they demonstrate the lack of peculiar acceleration in absorption line systems and the long-term frequency stability of modern radio telescopes. A comparison of UV metal absorption lines to the 21 cm line improves constraints on the cosmic variation of physical constants: {Delta}({alpha}{sup 2} g{sub p} {mu})/{alpha}{sup 2} g{sub p} {mu} = (- 1.2 {+-} 1.4) Multiplication-Sign 10{sup -6} in the redshift range z = 0.24-2.04. The linear evolution over the last 10.4 Gyr is (- 0.2 {+-} 2.7) Multiplication-Sign 10{sup -16} yr{sup -1}, consistent with no variation. The cosmic acceleration could be directly measured in {approx}125 years using current telescopes or in {approx}5 years using a Square Kilometer Array, but systematic effects will arise at the 1 cm s{sup -1} yr{sup -1} level.

  18. Online measurement of bead geometry in GMAW-based additive manufacturing using passive vision

    NASA Astrophysics Data System (ADS)

    Xiong, Jun; Zhang, Guangjun

    2013-11-01

    Additive manufacturing based on gas metal arc welding is an advanced technique for depositing fully dense components with low cost. Despite this fact, techniques to achieve accurate control and automation of the process have not yet been perfectly developed. The online measurement of the deposited bead geometry is a key problem for reliable control. In this work a passive vision-sensing system, comprising two cameras and composite filtering techniques, was proposed for real-time detection of the bead height and width through deposition of thin walls. The nozzle to the top surface distance was monitored for eliminating accumulated height errors during the multi-layer deposition process. Various image processing algorithms were applied and discussed for extracting feature parameters. A calibration procedure was presented for the monitoring system. Validation experiments confirmed the effectiveness of the online measurement system for bead geometry in layered additive manufacturing.

  19. Direct measurement of stain retention in third molars.

    PubMed

    Kurtir, R Steven; Boghossian, Berj Der; Kwon, So Ran

    2013-11-01

    To directly determine the mass of dye retained in teeth following exposure to aqueous solutions of Rhodamine B and to correlate tooth color modifications. Extracted third molars (25) were selected and sectioned at the cementoenamel junction for coronal staining. Pulp tissue was removed and teeth sonicated to remove debris. Teeth were kept in deionized water for 12 hours and subsequently weighed. They were then stained for 4 hours in 5 ml of Rhodamine B dye at two different concentrations. The samples were then subjected to two 8 hours rinses in deionized water. The tooth shade was recorded with a commercially available intraoral spectrophotometer (Vita Easyshade Compact, Vita Zahnfabrik, Bad Säckingen, Germany) at baseline (T1), after dye immersion (T2), and after water rinsing (T3). A standard absorption curve was then used to calculate the dye mass in the rinse solutions as well as the post- treatment stain solutions. All solution optical absorption curves were recorded using a laboratory research spectrophotometer (Cary 300, Agilent, USA). The mass of dye in each solution was then calculated from the standard curve relating optical absorption to aqueous dye concentration. An average change in the CIE (a) values of 8.0 ± 0.3 were observed for concentrations of Rhodamine B similar to the optical appearance of wine or other darkly colored juices while an increase of 10× in concentration gave values too high to measure using a standard intraoral spectrophotometer. By measuring the optical absorbance of the staining solutions before and after the staining process, we were able to measure dye retention of 54 ± 26 micrograms per gram of tooth. While no significant correlation could be found between the amount of stain retention in the dentition and the tooth shade due to the high uncertainties in the spectroscopic measurements, we were able to show that this method should admit such comparisons for future research. The development of a reliable chromophore

  20. Characterisation of the topography of metal additive surface features with different measurement technologies

    NASA Astrophysics Data System (ADS)

    Senin, Nicola; Thompson, Adam; Leach, Richard K.

    2017-09-01

    The challenges of measuring the surface topography of metallic surfaces produced by additive manufacturing are investigated. The differences between measurements made using various optical and non-optical technologies, including confocal and focus-variation microscopy, coherence scanning interferometry and x-ray computed tomography, are examined. As opposed to concentrating on differences which may arise through computing surface texture parameters from measured topography datasets, a comparative analysis is performed focussing on investigation of the quality of the topographic reconstruction of a series of surface features. The investigation is carried out by considering the typical surface features of a metal powder-bed fusion process: weld tracks, weld ripples, attached particles and surface recesses. Results show that no single measurement technology provides a completely reliable rendition of the topographic features that characterise the metal powder-bed fusion process. However, through analysis of measurement discrepancies, light can be shed on where instruments are more susceptible to error, and why differences between measurements occur. The results presented in this work increase the understanding of the behaviour and performance of areal topography measurement, and thus promote the development of improved surface characterisation pipelines.

  1. RIA R&D for Enabling Direct Neutron Cross-Section Measurements

    SciTech Connect

    Ahle, L E; Rusnak, B; Stoyer, M

    2003-08-22

    The expected production rates at RIA imply it should be possible to collect 10-{micro}g of a one-day half-life isotope. The amount of material should be sufficient to enable direct neutron cross-section measurements for many unstable isotopes. This capability is crucial for many of the stockpile stewardship and some of the astrophysical cross-section measurements. Enabling this capability at RIA requires the ability to harvest the desired isotopes, process highly radioactive material into targets, and irradiate targets with neutrons. This paper will discuss the changes and additions to the RIA complex that are necessary in order to enable direct neutron cross-section measurements. This will include a discussion of harvesting as well as a conceptual design for a co-located experimental facility with radiochemistry capability and a variable 'mono-energetic' neutron source.

  2. Direct power measurements on wind turbine array configurations

    NASA Astrophysics Data System (ADS)

    Delucia, Dominic; Cal, Raul Bayoan

    2012-11-01

    The reliability on the power extraction through wind turbines is an area of need given the increasing size of the arrays and energy demand. The turbulence effects generated by wind turbines on the subsequent rows downstream are assessed. Mechanical torque on the hubs of the model wind turbine is recorded and the power is calculated, where the measurements are performed in the Portland State University wind tunnel. Simultaneous torque and angular frequency of the rotors is record at three locations in a 3 by 4 wind turbine array. In this study, the effects due to in-line and staggered configurations are investigated. The base case configuration is a 3 by 4 array with a 6D downstream spacing and a 3D transverse spacing. The results are compared to wind turbine arrays of different spacing configurations. The trends in the data suggest the power is significantly increased when the downstream position are offset by 1.5D in the transverse direction not only for subsequent turbines but also when the turbines are staggered.

  3. Direct Measurement of the ^11C(,)^14N Reaction

    NASA Astrophysics Data System (ADS)

    Hayakawa, S.; Kubono, S.; Yamaguchi, H.; Hashimoto, T.; Binh, D. N.; Kahl, D.; Wakabayashi, Y.; Iwasa, N.; Kume, N.; Miura, Y.; Teranishi, T.; He, J. J.; Kwon, Y. K.; Komatsubara, T.; Kato, S.; Wanajo, S.

    2009-10-01

    A recent simulation of the rp-process in neutrino-driven winds in type II supernovae (νp-process) suggests that the ^11C(,)^14N reaction could be an important breakout pass from the pp-chain region to the CNO region. However, there are only very limited experimental information of the reaction cross section available from the time-reverse reaction studies. In order to determine the reaction rate of ^11C(,)^14N, a direct measurement by means of the thick-target inverse-kinematics method has recently been performed using low-energy ^11C beams from the CNS Radioactive Ion Beam (CRIB) separator, a ^4He gas target and δE-E position-sensitive silicon telescopes at three downstream angles. The experiment covered ECM = 0.5-5 MeV corresponding to the stellar temperature of 1.5-7GK. The obtained reaction cross section including some resonances and transitions to the excited states of ^14N will be reported.

  4. Direct measurement of floc breakage in flowing suspensions

    SciTech Connect

    Peng, S.J.; Williams, R.A. . Camborne School of Mines)

    1994-09-01

    Direct measurements of floc breakage behavior of silica and latex dispersions in a stirred tank and process pipeline have been performed using in situ scanning laser microscopy. The results show the effect of agitation intensity, flocculant dosage, and solids concentration on the floc formation and breakup in a stirred tanks. The effect of the rms velocity gradients on the floc breakage behavior in a process pipeline is also demonstrated and modeled using a quantitative relationship between the breakage constant (K) and the rms velocity gradient (G). These data provide a means of assessing, quantitatively, the strength of a floc population. Expressions for the mean dimensionless floc size R (scaled to the mean diameter of the primary particles) have been obtained for polymer-flocculated suspensions flowing in tubes. Typically R is given by (1 + aG[sup b]), where a and b depend on the volume concentration of solids. For 0.5% solids, a = 34.7, b = [minus]0.67; for 1.0% solids, a = 4.85, b= [minus]0.29.

  5. Measuring medical students' empathy using direct verbal expressions.

    PubMed

    Hur, Yera; Cho, A Ra; Kim, Sun

    2016-09-01

    Empathy is an important trait in physicians and a key element in the physician-patient relationship. Accordingly, one of the goals in medical education is developing empathy in students. We attempted to practically assess medical students' empathy through their direct verbal expressions. The medical students' empathy was measured using the modified Pencil-and-Paper Empathy Rating Test by Winefield and Chur-Hansen (2001). The students took 15 minutes or so to complete the scale, and it was then scored by one of two trained evaluators (0 to 4 points for each item, for a total score of 40). The subjects were 605 medical students, and the data were analyzed using descriptive analysis, independent t-test, and one-way analysis of variance in SPSS version 21.0. The students' empathy scores were low (mean, 12.13; standard deviation, 2.55); their most common responses (78.6%) registered as non-empathetic. Differences in empathy were observed by gender (female students>male students; t=-5.068, p<0.001), school system (medical school>medical college; t=-1.935, p=0.053), and academic level (pre-medical 1 year < other years; t=-4.050, p<0.001). Our findings lead us to the significant conclusion that there is the need for empathy enhancement training programs with practical content.

  6. Can Direct Measurement Videos Inspire Lab-like Learning?

    NASA Astrophysics Data System (ADS)

    Vonk, M.; Bohacek, P. H.

    2014-12-01

    Hands-on labs can offer students a rare opportunity to confront the laws of physics first hand and to gain experience using science practices. As such, hands-on labs are an important learning tool which have played a foundational role in science education since the time of Galileo. But labs also have features that make them difficult to implement in practice. They are often time consuming for the instructor to plan and setup, time consuming for students to perform, expensive to implement, and fraught with potential missteps that can send confused students into a spiral of misunderstanding. Our Direct Measurement Video team is working to create several series' of videos with an interface that allows students to interact with them in a way that (we hope) will start to feel lab-like, but with fewer of the impediments that tend to undermine lab-learning in the real world. We hope that lab-like videos will soon provide a needed complement to traditional hands-on labs in science classrooms across the nation. In this talk, I will present our vision of the pedagogical possibilities of video and highlight our progress toward the goal. This work is supported by NSF TUES award #1245268

  7. Measured and projected performance of plasma direct converters

    SciTech Connect

    Barr, W.L.; Moir, R.W.

    1981-10-22

    Test results from two plasma direct converters and their predicted cost and performance on tandem mirror fusion reactors are present. The tests were done at high power density (approx. 70 W/cm/sup 2/) in steady state to simulate the predicted conditions in a reactor. A single stage unit and a two-stage unit of the Venetian blind type were tested at up to 100 kV and 6 kW for a total time of about 80 hours. Measured efficiencies, when projected to a reactor, are typically about 50% for a single stage unit and 60 to 70% for a two-stage unit, depending on the energy distribution of the ions, the degree of subdivision of the collectors, and on the gas pressure. The high ambipolar potential in tandem mirror devices makes this good efficiency possible. When radiatively cooled grids are used, the incident power density is limited to about 100 W/cm/sup 2/ by the thermionic emission of electrons.

  8. Theoretical investigation of the effect of hydrogen addition on the formation and properties of soliton in direct current argon plasma

    NASA Astrophysics Data System (ADS)

    Saikia, P.; Goswami, K. S.; Saikia, B. K.

    2014-03-01

    In this study the effect of hydrogen addition on the formation and properties of soliton in direct-current (DC) argon plasma is theoretically investigated. By coupling fluid equations with Poisons equation for such multi-component plasma, the Mach number and amplitude of the soliton are determined following pseudo potential method. Addition of hydrogen in argon discharge leads to the decrease of electron, Ar+ ion density while a reverse trend was observed for ArH+ and hydrogen like ions. It was found that presence of hydrogen like ions in argon plasma affects the formation of soliton with its amplitude significantly decreases as concentration of hydrogen increases. On the other hand, increase in ion to electron temperature ratios of the lighter ions in the discharge also has a significant influence on the amplitude and formation of soliton. The inverse relation between solitons width and amplitude is found to be consistent for the entire range of study.

  9. Theoretical investigation of the effect of hydrogen addition on the formation and properties of soliton in direct current argon plasma

    SciTech Connect

    Saikia, P. Goswami, K. S.; Saikia, B. K.

    2014-03-15

    In this study the effect of hydrogen addition on the formation and properties of soliton in direct-current (DC) argon plasma is theoretically investigated. By coupling fluid equations with Poisons equation for such multi-component plasma, the Mach number and amplitude of the soliton are determined following pseudo potential method. Addition of hydrogen in argon discharge leads to the decrease of electron, Ar{sup +} ion density while a reverse trend was observed for ArH{sup +} and hydrogen like ions. It was found that presence of hydrogen like ions in argon plasma affects the formation of soliton with its amplitude significantly decreases as concentration of hydrogen increases. On the other hand, increase in ion to electron temperature ratios of the lighter ions in the discharge also has a significant influence on the amplitude and formation of soliton. The inverse relation between solitons width and amplitude is found to be consistent for the entire range of study.

  10. Direct measurement of clinical mammographic x-ray spectra using a CdTe spectrometer.

    PubMed

    Santos, Josilene C; Tomal, Alessandra; Furquim, Tânia A; Fausto, Agnes M F; Nogueira, Maria S; Costa, Paulo R

    2017-07-01

    To introduce and evaluate a method developed for the direct measurement of mammographic x-ray spectra using a CdTe spectrometer. The assembly of a positioning system and the design of a simple and customized alignment device for this application is described. A positioning system was developed to easily and accurately locate the CdTe detector in the x-ray beam. Additionally, an alignment device to line up the detector with the central axis of the radiation beam was designed. Direct x-ray spectra measurements were performed in two different clinical mammography units and the measured x-ray spectra were compared with computer-generated spectra. In addition, the spectrometer misalignment effect was evaluated by comparing the measured spectra when this device is aligned relatively to when it is misaligned. The positioning and alignment of the spectrometer have allowed the measurements of direct mammographic x-ray spectra in agreement with computer-generated spectra. The most accurate x-ray spectral shape, related with the minimal HVL value, and high photon fluence for measured spectra was found with the spectrometer aligned according to the proposed method. The HVL values derived from both simulated and measured x-ray spectra differ at most 1.3 and 4.5% for two mammography devices evaluated in this study. The experimental method developed in this work allows simple positioning and alignment of a spectrometer for x-ray spectra measurements given the geometrical constraints and maintenance of the original configurations of mammography machines. © 2017 American Association of Physicists in Medicine.

  11. A new approach to handle additive and multiplicative uncertainties in the measurement for ? LPV filtering

    NASA Astrophysics Data System (ADS)

    Lacerda, Márcio J.; Tognetti, Eduardo S.; Oliveira, Ricardo C. L. F.; Peres, Pedro L. D.

    2016-04-01

    This paper presents a general framework to cope with full-order ? linear parameter-varying (LPV) filter design subject to inexactly measured parameters. The main novelty is the ability of handling additive and multiplicative uncertainties in the measurements, for both continuous and discrete-time LPV systems, in a unified approach. By conveniently modelling scheduling parameters and uncertainties affecting the measurements, the ? filter design problem can be expressed in terms of robust matrix inequalities that become linear when two scalar parameters are fixed. Therefore, the proposed conditions can be efficiently solved through linear matrix inequality relaxations based on polynomial solutions. Numerical examples are presented to illustrate the improved efficiency of the proposed approach when compared to other methods and, more important, its capability to deal with scenarios where the available strategies in the literature cannot be used.

  12. Direct Measurement of Changes to a Sheared Shale Fracture

    NASA Astrophysics Data System (ADS)

    Stadleman, M.; Bromhal, G. S.; Moore, J.; Gill, M.; Crandall, D.

    2015-12-01

    Shales are of particular interest both for their energy production potential and their ability to provide seals for sequestered CO2. It is imperative to understand the processes that influence fracture properties in order to accurately predict subsurface behavior. In order to evaluate the coupled hydrologic and geometric changes to a fracture undergoing shear displacement, a novel apparatus was used to produce real-time shearing of fractured shale at elevated pressures. Intermittent computed tomography (CT) scans were performed during each shearing event and transmissivity measurements taken to characterize both the mechanical evolution as well as the hydrodynamic response of the fracture. The initial fractures examined had small apertures and high resistance to flow, with most aperture values below the resolution of the CT scanner and low transmissivities. Initial shearing events, with total displacement less than two mm, minimally increased the aperture and increased the transmissivity. Further shearing resulted in fracture apertures that were large with pressure differentials across the core below the detection limit of the pressure measurement equipment. Flow models using the complex fracture geometries obtained from the CT scanning was performed to examine the micro-scale impacts of fracture evolution on the flow field that were not apparent in the bulk data. These results showed strong flow channelization within the larger aperture regions and showed that hydraulic aperture was significantly different than average mechanical apertures. Fracture aperture evolution due to shearing was characterized with the resulting mechanical and hydrologic responses. Apertures showed increases after each shearing event. Additionally, this increased aperture resulted in increased transmissivity and subsequent increases in hydraulic aperture. Coupling the experimental work with computational analysis provided further insight into the evolution of fracture flow properties.

  13. Directly measuring single-molecule heterogeneity using force spectroscopy

    PubMed Central

    Hinczewski, Michael; Thirumalai, D.

    2016-01-01

    One of the most intriguing results of single-molecule experiments on proteins and nucleic acids is the discovery of functional heterogeneity: the observation that complex cellular machines exhibit multiple, biologically active conformations. The structural differences between these conformations may be subtle, but each distinct state can be remarkably long-lived, with interconversions between states occurring only at macroscopic timescales, fractions of a second or longer. Although we now have proof of functional heterogeneity in a handful of systems—enzymes, motors, adhesion complexes—identifying and measuring it remains a formidable challenge. Here, we show that evidence of this phenomenon is more widespread than previously known, encoded in data collected from some of the most well-established single-molecule techniques: atomic force microscopy or optical tweezer pulling experiments. We present a theoretical procedure for analyzing distributions of rupture/unfolding forces recorded at different pulling speeds. This results in a single parameter, quantifying the degree of heterogeneity, and also leads to bounds on the equilibration and conformational interconversion timescales. Surveying 10 published datasets, we find heterogeneity in 5 of them, all with interconversion rates slower than 10 s−1. Moreover, we identify two systems where additional data at realizable pulling velocities is likely to find a theoretically predicted, but so far unobserved crossover regime between heterogeneous and nonheterogeneous behavior. The significance of this regime is that it will allow far more precise estimates of the slow conformational switching times, one of the least understood aspects of functional heterogeneity. PMID:27317744

  14. Using a Simple Apparatus to Measure Direct and Diffuse Photosynthetically Active Radiation at Remote Locations

    PubMed Central

    Cruse, Michael J.; Kucharik, Christopher J.; Norman, John M.

    2015-01-01

    Plant canopy interception of photosynthetically active radiation (PAR) drives carbon dioxide (CO2), water and energy cycling in the soil-plant-atmosphere system. Quantifying intercepted PAR requires accurate measurements of total incident PAR above canopies and direct beam and diffuse PAR components. While some regional data sets include these data, e.g. from Atmospheric Radiation Measurement (ARM) Program sites, they are not often applicable to local research sites because of the variable nature (spatial and temporal) of environmental variables that influence incoming PAR. Currently available instrumentation that measures diffuse and direct beam radiation separately can be cost prohibitive and require frequent adjustments. Alternatively, generalized empirical relationships that relate atmospheric variables and radiation components can be used but require assumptions that increase the potential for error. Our goal here was to construct and test a cheaper, highly portable instrument alternative that could be used at remote field sites to measure total, diffuse and direct beam PAR for extended time periods without supervision. The apparatus tested here uses a fabricated, solar powered rotating shadowband and other commercially available parts to collect continuous hourly PAR data. Measurements of total incident PAR had nearly a one-to-one relationship with total incident radiation measurements taken at the same research site by an unobstructed point quantum sensor. Additionally, measurements of diffuse PAR compared favorably with modeled estimates from previously published data, but displayed significant differences that were attributed to the important influence of rapidly changing local environmental conditions. The cost of the system is about 50% less than comparable commercially available systems that require periodic, but not continual adjustments. Overall, the data produced using this apparatus indicates that this instrumentation has the potential to support

  15. Using a simple apparatus to measure direct and diffuse photosynthetically active radiation at remote locations.

    PubMed

    Cruse, Michael J; Kucharik, Christopher J; Norman, John M

    2015-01-01

    Plant canopy interception of photosynthetically active radiation (PAR) drives carbon dioxide (CO2), water and energy cycling in the soil-plant-atmosphere system. Quantifying intercepted PAR requires accurate measurements of total incident PAR above canopies and direct beam and diffuse PAR components. While some regional data sets include these data, e.g. from Atmospheric Radiation Measurement (ARM) Program sites, they are not often applicable to local research sites because of the variable nature (spatial and temporal) of environmental variables that influence incoming PAR. Currently available instrumentation that measures diffuse and direct beam radiation separately can be cost prohibitive and require frequent adjustments. Alternatively, generalized empirical relationships that relate atmospheric variables and radiation components can be used but require assumptions that increase the potential for error. Our goal here was to construct and test a cheaper, highly portable instrument alternative that could be used at remote field sites to measure total, diffuse and direct beam PAR for extended time periods without supervision. The apparatus tested here uses a fabricated, solar powered rotating shadowband and other commercially available parts to collect continuous hourly PAR data. Measurements of total incident PAR had nearly a one-to-one relationship with total incident radiation measurements taken at the same research site by an unobstructed point quantum sensor. Additionally, measurements of diffuse PAR compared favorably with modeled estimates from previously published data, but displayed significant differences that were attributed to the important influence of rapidly changing local environmental conditions. The cost of the system is about 50% less than comparable commercially available systems that require periodic, but not continual adjustments. Overall, the data produced using this apparatus indicates that this instrumentation has the potential to support

  16. Prediction of All-Cause Mortality Based on the Direct Measurement of Intrathoracic Impedance.

    PubMed

    Zile, Michael R; Sharma, Vinod; Johnson, James W; Warman, Eduardo N; Baicu, Catalin F; Bennett, Tom D

    2016-01-01

    Intrathoracic impedance-derived OptiVol fluid index calculated using implanted devices has been shown to predict mortality; direct measurements of impedance have not been examined. We hypothesized that baseline measured impedance predicts all-cause mortality; changes in measured impedance result in a change in the predicted mortality; and the prognostic value of measured impedance is additive to the calculated OptiVol fluid index. A retrospective analysis of 146,238 patients within the Medtronic CareLink database with implanted devices was performed. Baseline measured impedance was determined using daily values averaged from month 6 to 9 after implant and were used to divide patients into tertiles: group L = low impedance, ≤ 65 ohms; group M = medium impedance, 66 to 72 ohms; group H = high impedance, ≥ 73 ohms. Change in measured impedance was determined from values averaged from month 9 to 12 post implant compared with the 6- to 9-month values. OptiVol fluid index was calculated using published methods. All-cause mortality was assessed beginning 9 months post implant; changes in mortality was assessed beginning 12 months post implant. Baseline measured impedance predicted all-cause mortality; 5-year mortality for group L was 41%, M was 29%, and H was 25%, P < 0.001 among all groups. Changes in measured impedance resulted in a change in the predicted mortality; the prognostic value of measured impedance was additive to the OptiVol fluid index. Direct measurements of intrathoracic impedance using an implanted device can be used to stratify patients at varying mortality risk. © 2015 American Heart Association, Inc.

  17. Prediction of All-Cause Mortality Based on the Direct Measurement of Intrathoracic Impedance

    PubMed Central

    Zile, Michael R.; Sharma, Vinod; Johnson, James W.; Warman, Eduardo N.; Baicu, Catalin F.; Bennett, Tom D.

    2015-01-01

    Background Intrathoracic impedance-derived OptiVol fluid index calculated using implanted devices has been shown to predict mortality; direct measurements of impedance have not been examined. We hypothesized that baseline measured impedance predicts all-cause mortality; changes in measured impedance result in a change in the predicted mortality; and the prognostic value of measured impedance is additive to the calculated OptiVol fluid index. Methods and Results A retrospective analysis of 146,238 patients within the Medtronic CareLink data base with implanted devices was performed. Baseline measured impedance was determined using daily values averaged from month 6 to 9 post implant and were used to divide patients into tertiles; Group L= Low Impedance: ≤ 65 ohms, M= Medium Impedance: 66–72 ohms, H= High Impedance: ≥ 73 ohms. Change in measured impedance was determined from values averaged from month 9 to 12 post implant compared to the 6 to 9 month values. OptiVol fluid index was calculated using published methods. All-cause mortality was assessed beginning 9 months post implant; changes in mortality beginning 12 months post implant. Baseline measured impedance predicted all-cause mortality; 5 year mortality for group L was 41%, M was 29%, H was 25%, p < 0.001 among all groups. Changes in measured impedance resulted in a change in the predicted mortality; the prognostic value of measured impedance was additive to the OptiVol fluid index. Conclusions Direct measurements of intrathoracic impedance using an implanted device can be used to stratify patients at varying mortality risk. PMID:26699393

  18. Taxis assays measure directional movement of mosquitoes to olfactory cues

    PubMed Central

    2013-01-01

    Background Malaria control methods targeting indoor-biting mosquitoes have limited impact on vectors that feed and rest outdoors. Exploiting mosquito olfactory behaviour to reduce blood-feeding outdoors might be a sustainable approach to complement existing control strategies. Methodologies that can objectively quantify responses to odour under realistic field conditions and allow high-throughput screening of many compounds are required for development of effective odour-based control strategies. Methods The olfactory responses of laboratory-reared Anopheles gambiae in a semi-field tunnel and A. arabiensis females in an outdoor field setting to three stimuli, namely whole human odour, a synthetic blend of carboxylic acids plus carbon dioxide and CO2 alone at four distances up to 100 metres were measured in two experiments using three-chambered taxis boxes that allow mosquito responses to natural or experimentally-introduced odour cues to be quantified. Results Taxis box assays could detect both activation of flight and directional mosquito movement. Significantly more (6-18%) A. arabiensis mosquitoes were attracted to natural human odour in the field up to 30 metres compared to controls, and blended synthetic human odours attracted 20% more A. gambiae in the semi-field tunnel up to 70 metres. Whereas CO2 elicited no response in A. arabiensis in the open field, it was attractive to A. gambiae up to 50 metres (65% attraction compared to 36% in controls). Conclusions We have developed a simple reproducible system to allow for the comparison of compounds that are active over medium- to long-ranges in semi-field or full-field environments. Knowing the natural range of attraction of anopheline mosquitoes to potential blood sources has substantial implications for the design of malaria control strategies, and adds to the understanding of olfactory behaviour in mosquitoes. This experimental strategy could also be extended from malaria vectors to other motile arthropods of

  19. Taxis assays measure directional movement of mosquitoes to olfactory cues.

    PubMed

    Lorenz, Lena M; Keane, Aidan; Moore, Jason D; Munk, Cristina J; Seeholzer, Laura; Mseka, Antony; Simfukwe, Emmanuel; Ligamba, Joseph; Turner, Elizabeth L; Biswaro, Lubandwa R; Okumu, Fredros O; Killeen, Gerry F; Mukabana, Wolfgang R; Moore, Sarah J

    2013-05-03

    Malaria control methods targeting indoor-biting mosquitoes have limited impact on vectors that feed and rest outdoors. Exploiting mosquito olfactory behaviour to reduce blood-feeding outdoors might be a sustainable approach to complement existing control strategies. Methodologies that can objectively quantify responses to odour under realistic field conditions and allow high-throughput screening of many compounds are required for development of effective odour-based control strategies. The olfactory responses of laboratory-reared Anopheles gambiae in a semi-field tunnel and A. arabiensis females in an outdoor field setting to three stimuli, namely whole human odour, a synthetic blend of carboxylic acids plus carbon dioxide and CO(2) alone at four distances up to 100 metres were measured in two experiments using three-chambered taxis boxes that allow mosquito responses to natural or experimentally-introduced odour cues to be quantified. Taxis box assays could detect both activation of flight and directional mosquito movement. Significantly more (6-18%) A. arabiensis mosquitoes were attracted to natural human odour in the field up to 30 metres compared to controls, and blended synthetic human odours attracted 20% more A. gambiae in the semi-field tunnel up to 70 metres. Whereas CO(2) elicited no response in A. arabiensis in the open field, it was attractive to A. gambiae up to 50 metres (65% attraction compared to 36% in controls). We have developed a simple reproducible system to allow for the comparison of compounds that are active over medium- to long-ranges in semi-field or full-field environments. Knowing the natural range of attraction of anopheline mosquitoes to potential blood sources has substantial implications for the design of malaria control strategies, and adds to the understanding of olfactory behaviour in mosquitoes. This experimental strategy could also be extended from malaria vectors to other motile arthropods of medical, veterinary and

  20. Direct Measures of Writing Skill: Issues and Applications. Revised Edition.

    ERIC Educational Resources Information Center

    Spandel, Vicki; Stiggins, Richard J.

    Intended for educators seeking information on direct writing assessments, this monograph describes general procedures for planning and conducting a writing assessment and strategies for tailoring that assessment to local needs. The introductory chapter offers a brief comparison of direct and indirect writing assessment methods, highlighting those…

  1. 21 CFR 882.1570 - Powered direct-contact temperature measurement device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Powered direct-contact temperature measurement....1570 Powered direct-contact temperature measurement device. (a) Identification. A powered direct-contact temperature measurement device is a device which contains a power source and is used to measure...

  2. 21 CFR 882.1570 - Powered direct-contact temperature measurement device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered direct-contact temperature measurement....1570 Powered direct-contact temperature measurement device. (a) Identification. A powered direct-contact temperature measurement device is a device which contains a power source and is used to measure...

  3. 21 CFR 882.1570 - Powered direct-contact temperature measurement device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Powered direct-contact temperature measurement....1570 Powered direct-contact temperature measurement device. (a) Identification. A powered direct-contact temperature measurement device is a device which contains a power source and is used to measure...

  4. 21 CFR 882.1570 - Powered direct-contact temperature measurement device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Powered direct-contact temperature measurement....1570 Powered direct-contact temperature measurement device. (a) Identification. A powered direct-contact temperature measurement device is a device which contains a power source and is used to measure...

  5. 21 CFR 882.1570 - Powered direct-contact temperature measurement device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Powered direct-contact temperature measurement....1570 Powered direct-contact temperature measurement device. (a) Identification. A powered direct-contact temperature measurement device is a device which contains a power source and is used to measure...

  6. A self-sensing active magnetic bearing based on a direct current measurement approach.

    PubMed

    Niemann, Andries C; van Schoor, George; du Rand, Carel P

    2013-09-11

    Active magnetic bearings (AMBs) have become a key technology in various industrial applications. Self-sensing AMBs provide an integrated sensorless solution for position estimation, consolidating the sensing and actuating functions into a single electromagnetic transducer. The approach aims to reduce possible hardware failure points, production costs, and system complexity. Despite these advantages, self-sensing methods must address various technical challenges to maximize the performance thereof. This paper presents the direct current measurement (DCM) approach for self-sensing AMBs, denoting the direct measurement of the current ripple component. In AMB systems, switching power amplifiers (PAs) modulate the rotor position information onto the current waveform. Demodulation self-sensing techniques then use bandpass and lowpass filters to estimate the rotor position from the voltage and current signals. However, the additional phase-shift introduced by these filters results in lower stability margins. The DCM approach utilizes a novel PA switching method that directly measures the current ripple to obtain duty-cycle invariant position estimates. Demodulation filters are largely excluded to minimize additional phase-shift in the position estimates. Basic functionality and performance of the proposed self-sensing approach are demonstrated via a transient simulation model as well as a high current (10 A) experimental system. A digital implementation of amplitude modulation self-sensing serves as a comparative estimator.

  7. A Self-Sensing Active Magnetic Bearing Based on a Direct Current Measurement Approach

    PubMed Central

    Niemann, Andries C.; van Schoor, George; du Rand, Carel P.

    2013-01-01

    Active magnetic bearings (AMBs) have become a key technology in various industrial applications. Self-sensing AMBs provide an integrated sensorless solution for position estimation, consolidating the sensing and actuating functions into a single electromagnetic transducer. The approach aims to reduce possible hardware failure points, production costs, and system complexity. Despite these advantages, self-sensing methods must address various technical challenges to maximize the performance thereof. This paper presents the direct current measurement (DCM) approach for self-sensing AMBs, denoting the direct measurement of the current ripple component. In AMB systems, switching power amplifiers (PAs) modulate the rotor position information onto the current waveform. Demodulation self-sensing techniques then use bandpass and lowpass filters to estimate the rotor position from the voltage and current signals. However, the additional phase-shift introduced by these filters results in lower stability margins. The DCM approach utilizes a novel PA switching method that directly measures the current ripple to obtain duty-cycle invariant position estimates. Demodulation filters are largely excluded to minimize additional phase-shift in the position estimates. Basic functionality and performance of the proposed self-sensing approach are demonstrated via a transient simulation model as well as a high current (10 A) experimental system. A digital implementation of amplitude modulation self-sensing serves as a comparative estimator. PMID:24030681

  8. DIRECT MEASUREMENT OF MERCURY REACTIONS IN COAL POWER PLANT PLUMES

    SciTech Connect

    Leonard Levin

    2006-06-01

    -September 5, 2003. The experimental site was the Pleasant Prairie Power Plant in Pleasant Prairie, Wisconsin, just west of Kenosha. The experiment involved using an aircraft to capture emissions and document chemistry changes in the plume. While using the airplane for sampling, supplemental fast-response sensors for NOx, connected to data loggers, were used to gauge entry and exit times and transect intervals through plume emissions material. The Frontier Geosciences Static Plume Dilution Chamber (SPDC) was employed simultaneously adjacent to the stack to correlate its findings with the aircraft sampling, as well as providing evaluation of the SPDC as a rapid, less costly sampler for mercury chemistry. A complementary stack plume method, the Dynamic Plume Dilution (DPD) was used in the latter portion of the experiment to measure mercury speciation to observe any mercury reduction reaction with respect to both the reaction time (5 to 30 seconds) and dilution ratio. In addition, stack sampling using the ''Ontario Hydro'' wet chemistry method and continuous mercury monitors (CMM) were used to establish the baseline chemistry in the stack. Comparisons among stack, SPDC, DPD and aircraft measurements allow establishment of whether significant chemical changes to mercury occur in the plume, and of the verisimilitude of the SPDC and DPD methods. This progress report summarizes activities during a period of results review from the stack/aircraft subcontractor, data analysis and synthesis, and preparation and presentation of preliminary results to technical and oversight meetings.

  9. DIRECT MEASUREMENT OF MERCURY REACTIONS IN COAL POWER PLANT PLUMES

    SciTech Connect

    Leonard Levin

    2004-01-01

    -September 5, 2003. The experimental site was the Pleasant Prairie Power Plant in Pleasant Prairie, Wisconsin, just west of Kenosha. The experiment involved using an aircraft to capture emissions and document chemistry changes in the plume. While using the airplane for sampling, supplemental fast-response sensors for NOx, connected to data loggers, were used to gauge entry and exit times and transect intervals through plume emissions material. The Frontier Geosciences Static Plume Dilution Chamber (SPDC) was employed simultaneously adjacent to the stack to correlate its findings with the aircraft sampling, as well as providing evaluation of the SPDC as a rapid, less costly sampler for mercury chemistry. A complementary stack plume method, the Dynamic Plume Dilution (DPD) was used in the latter portion of the experiment to measure mercury speciation to observe any mercury reduction reaction with respect to both the reaction time (5 to 30 seconds) and dilution ratio. In addition, stack sampling using the ''Ontario Hydro'' wet chemistry method and continuous mercury monitors (CMM) were used to establish the baseline chemistry in the stack. Comparisons among stack, SPDC, DPD and aircraft measurements following data analysis will allow establishment of whether significant chemical changes to mercury occur in the plume, and of the verisimilitude of the SPDC and DPD methods.

  10. Boundedness of completely additive measures with application to 2-local triple derivations

    NASA Astrophysics Data System (ADS)

    Hamhalter, Jan; Kudaybergenov, Karimbergen; Peralta, Antonio M.; Russo, Bernard

    2016-02-01

    We prove a Jordan version of Dorofeev's boundedness theorem for completely additive measures and use it to show that every (not necessarily linear nor continuous) 2-local triple derivation on a continuous JBW∗-triple is a triple derivation. 2-local triple derivations are well understood on von Neumann algebras. JBW*-triples, which are properly defined in Section I, are intimately related to infinite dimensional holomorphy and include von Neumann algebras as special cases. In particular, continuous JBW∗-triples can be realized as subspaces of continuous von Neumann algebras which are stable for the triple product xy∗z + zy∗x and closed in the weak operator topology.

  11. A multiple additive regression tree analysis of three exposure measures during Hurricane Katrina.

    PubMed

    Curtis, Andrew; Li, Bin; Marx, Brian D; Mills, Jacqueline W; Pine, John

    2011-01-01

    This paper analyses structural and personal exposure to Hurricane Katrina. Structural exposure is measured by flood height and building damage; personal exposure is measured by the locations of 911 calls made during the response. Using these variables, this paper characterises the geography of exposure and also demonstrates the utility of a robust analytical approach in understanding health-related challenges to disadvantaged populations during recovery. Analysis is conducted using a contemporary statistical approach, a multiple additive regression tree (MART), which displays considerable improvement over traditional regression analysis. By using MART, the percentage of improvement in R-squares over standard multiple linear regression ranges from about 62 to more than 100 per cent. The most revealing finding is the modelled verification that African Americans experienced disproportionate exposure in both structural and personal contexts. Given the impact of exposure to health outcomes, this finding has implications for understanding the long-term health challenges facing this population.

  12. Direct Measurement of Recoil Effects on Ar-Ar Standards

    NASA Astrophysics Data System (ADS)

    Hall, C. M.

    2011-12-01

    Advances in the precision possible with the Ar-Ar method using new techniques and equipment have led to considerable effort to improve the accuracy of the calibration of interlaboratory standards. However, ultimately the accuracy of the method relies on the measurement of 40Ar*/39ArK ratios on primary standards that have been calibrated with the K-Ar method and, in turn, on secondary standards that are calibrated against primary standards. It is usually assumed that an Ar-Ar total gas age is equivalent to a K-Ar age, but this assumes that there is zero loss of Ar due to recoil. Instead, traditional Ar-Ar total gas ages are in fact Ar retention ages [1] and not, strictly speaking, comparable to K-Ar ages. There have been efforts to estimate the importance of this effect on standards along with prescriptions for minimizing recoil effects [2,3], but these studies have relied on indirect evidence for 39Ar recoil. We report direct measurements of 39Ar recoil for a set of primary and secondary standards using the vacuum encapsulation techniques of [1] and show that significant adjustments to ages assigned to some standards may be needed. The fraction f of 39Ar lost due to recoil for primary standards MMhb-1 hornblende and GA-1550 biotite are 0.00367 and 0.00314 respectively. It is possible to modify the assumed K-Ar ages of these standards so that when using their measured Ar retention 40Ar*/39ArK ratios, one obtains a correct K-Ar age for an unknown, assuming that the unknown sample has zero loss of 39Ar due to recoil. Assuming a primary K-Ar age for MMhb-1 of 520.4 Ma, the modified age would be 522.1 Ma and assuming a primary K-Ar age for GA-1550 of 98.79 Ma [4] yields a modified effective age of 99.09 Ma. Measured f values for secondary standards FCT-3 biotite, FCT-2 sanidine and TCR-2 sanidine are 0.00932, 0.00182 and 0.00039 respectively. Using an R value for FCT-3 biotite relative to MMhb-1 [5], the K-Ar age for this standard would be 27.83 Ma and using R values

  13. An Optical Sensor for Measuring the Position and Slanting Direction of Flat Surfaces

    PubMed Central

    Chen, Yu-Ta; Huang, Yen-Sheng; Liu, Chien-Sheng

    2016-01-01

    Automated optical inspection is a very important technique. For this reason, this study proposes an optical non-contact slanting surface measuring system. The essential features of the measurement system are obtained through simulations using the optical design software Zemax. The actual propagation of laser beams within the measurement system is traced by using a homogeneous transformation matrix (HTM), the skew-ray tracing method, and a first-order Taylor series expansion. Additionally, a complete mathematical model that describes the variations in light spots on photoelectric sensors and the corresponding changes in the sample orientation and distance was established. Finally, a laboratory prototype system was constructed on an optical bench to verify experimentally the proposed system. This measurement system can simultaneously detect the slanting angles (x, z) in the x and z directions of the sample and the distance (y) between the biconvex lens and the flat sample surface. PMID:27409619

  14. Technique for direct measurement of magnetic entropy of solids: Results for dysprosium titanium oxide

    NASA Technical Reports Server (NTRS)

    Flood, D. J.

    1974-01-01

    A measurement technique was devised which permits direct observation of the magnetic entropy of solids as a function of applied magnetic field. Measurements were made of the magnetic entropy, in the temperature range 2 to 20 K, of polycrystalline samples of dysprosium titanium oxide (Dy2Ti2O7) to determine its suitability for use as the working substance of a magnetic refrigerator. Magnetization measurements were also made at 4.2 K and below to provide additional information on the nature of the compound. The measurements indicated that crystalline electric fields perturbed the ground state of the dysprosium ions, removed the 16-fold degeneracy predicted by Hund's rules, and left only a twofold degeneracy in its place. A positive, temperature independent contribution to the magnetization was observed in the saturation region, which indicated that the doublet ground-state wave function was perturbed by a nearby unpopulated upper energy level.

  15. Experimental analysis on semi-finishing machining of Ti6Al4V additively manufactured by direct melting laser sintering

    NASA Astrophysics Data System (ADS)

    Imbrogno, Stano; Bordin, Alberto; Bruschi, Stefania; Umbrello, Domenico

    2016-10-01

    The Additive Manufacturing (AM) techniques are particularly appealing especially for titanium aerospace and biomedical components because they permit to achieve a strong reduction of the buy-to-fly ratio. However, finishing machining operations are often necessary to reduce the uneven surface roughness and geometrics because of local missing accuracy. This work shows the influence of the cutting parameters, cutting speed and feed rate, on the cutting forces as well as on the thermal field observed in the cutting zone, during a turning operation carried out on bars made of Ti6Al4V obtained by the AM process called Direct Metal Laser Sintering (DMLS). Moreover, the sub-surface microstructure alterations due to the process are also showed and commented.

  16. Calcium Carbonate Nanoplate Assemblies with Directed High-Energy Facets: Additive-Free Synthesis, High Drug Loading, and Sustainable Releasing.

    PubMed

    Zhang, Jing; Li, Yu; Xie, Hao; Su, Bao-Lian; Yao, Bin; Yin, Yixia; Li, Shipu; Chen, Fang; Fu, Zhengyi

    2015-07-29

    Developing drug delivery systems (DDSs) with high drug-loading capacity and sustainable releasing is critical for long-term chemotherapeutic efficacy, and it still remains challenging. Herein, vaterite CaCO3 nanoplate assemblies with exposed high-energy {001} facets have been synthesized via a novel, additive-free strategy. The product shows a high doxorubicin-loading capacity (65%); the best of all the CaCO3-based DDSs so far. Also, the product's sustainable releasing performance and its inhibition of the initial burst release, together, endow it with long-term drug efficacy. The work may shed light on exposing directed high-energy facets for rationally designing of a drug delivery system with long-term efficacy.

  17. Modelling the role of intrinsic electric fields in microtubules as an additional control mechanism of bi-directional intracellular transport.

    PubMed

    Sataric, M V; Budinski-Petkovic, L; Loncarevic, I; Tuszynski, J A

    2008-01-01

    Active transport is essential for cellular function, while impaired transport has been linked to diseases such as neuronal degeneration. Much long distance transport in cells uses opposite polarity molecular motors of the kinesin and dynein families to move cargos along microtubules. It is clear that many types of cargo are moved by both sets of motors, and frequently in a reverse direction. The general question of how the direction of transport is regulated is still open. The mechanism of the cell's differential control of diverse cargos within the same cytoplasmic background is still unclear as is the answer to the question how endosomes and mitochondria move to different locations within the same cell. To answer these questions we postulate the existence of a local signaling mechanism used by the cell to specifically control different cargos. In particular, we propose an additional physical mechanism that works through the use of constant and alternating intrinsic (endogenous) electric fields as a means of controlling the speed and direction of microtubule-based transport. A specific model is proposed and analyzed in this paper. The model involves the rotational degrees of freedom of the C-termini of tubulin, their interactions and the coupling between elastic and dielectric degrees of freedom. Viscosity of the solution is also included and the resultant equation of motion is found as a nonlinear elliptic equation with dissipation. A particular analytical solution of this equation is obtained in the form of a kink whose properties are analyzed. It is concluded that this solution can be modulated by the presence of electric fields and hence may correspond to the observed behavior of motor protein transport along microtubules.

  18. Neutron measurements of stresses in a test artifact produced by laser-based additive manufacturing

    SciTech Connect

    Gnäupel-Herold, Thomas; Slotwinski, John; Moylan, Shawn

    2014-02-18

    A stainless steel test artifact produced by Direct Metal Laser Sintering and similar to a proposed standardized test artifact was examined using neutron diffraction. The artifact contained a number of structures with different aspect ratios pertaining to wall thickness, height above base plate, and side length. Through spatial resolutions of the order of one millimeter the volumetric distribution of stresses in several was measured. It was found that the stresses peak in the tensile region around 500 MPa near the top surface, with balancing compressive stresses in the interior. The presence of a support structure (a one millimeter high, thin walled, hence weaker, lattice structure deposited on the base plate, followed by a fully dense AM structure) has only minor effects on the stresses.

  19. Neutron measurements of stresses in a test artifact produced by laser-based additive manufacturing

    NASA Astrophysics Data System (ADS)

    Gnäupel-Herold, Thomas; Slotwinski, John; Moylan, Shawn

    2014-02-01

    A stainless steel test artifact produced by Direct Metal Laser Sintering and similar to a proposed standardized test artifact was examined using neutron diffraction. The artifact contained a number of structures with different aspect ratios pertaining to wall thickness, height above base plate, and side length. Through spatial resolutions of the order of one millimeter the volumetric distribution of stresses in several was measured. It was found that the stresses peak in the tensile region around 500 MPa near the top surface, with balancing compressive stresses in the interior. The presence of a support structure (a one millimeter high, thin walled, hence weaker, lattice structure deposited on the base plate, followed by a fully dense AM structure) has only minor effects on the stresses.

  20. Additional Measurements and Analyses of H217O and H218O

    NASA Astrophysics Data System (ADS)

    Pearson, John; Yu, Shanshan; Walters, Adam; Daly, Adam M.

    2015-06-01

    Historically the analysis of the spectrum of water has been a balance between the quality of the data set and the applicability of the Hamiltonian to a highly non-rigid molecule. Recently, a number of different non-rigid analysis approaches have successfully been applied to 16O water resulting in a self-consistent set of transitions and energy levels to high J which allowed the spectrum to be modeled to experimental precision. The data set for 17O and 18O water was previously reviewed and many of the problematic measurements identified, but Hamiltonian modeling of the remaining data resulted in significantly poorer quality fits than that for the 16O parent. As a result, we have made additional microwave measurements and modeled the existing 17O and 18O data sets with an Euler series model. This effort has illuminated a number of additional problematic measurements in the previous data sets and has resulted in analyses of 17O and 18O water that are of similar quality to the 16O analysis. We report the new lines, the analyses and make recommendations on the quality of the experimental data sets. SS. Yu, J.C. Pearson, B.J. Drouin et al. J. Mol. Spectrosc. 279,~16-25 (2012) J. Tennyson, P.F. Bernath, L.R. Brown et al. J. Quant. Spectrosc. Rad. Trans. 117, 29-58 (2013) J. Tennyson, P.F. Bernath, L.R. Brown et al. J. Quant. Spectrosc. Rad. Trans. 110, 573-596 (2009) H.M. Pickett, J.C. Pearson, C.E. Miller J. Mol. Spectrosc. 233, 174-179 (2005)

  1. Predictive measures of directional benefit part 1: estimating the directivity index on a manikin.

    PubMed

    Dittberner, Andrew B; Bentler, Ruth A

    2007-02-01

    In this investigation, a method for computing a directivity index (DI) on a manikin for directional microphones in hearing aids was proposed and evaluated comparatively to other conventional methods. Test devices included first- and second-order directional microphones. Signal presentation, implemented in an anechoic chamber, involved a single noise source rotated completely around the directional microphone in a hearing aid, in free field and on a manikin, at a defined radius. The area covered was equivalent to the approximate surface area of a sphere. It was anticipated that an equal angular resolution of 10 degrees (elevation and azimuth) would effectively estimate the DI of first-, second-, and higher-order directional microphone systems located in a hearing aid on a manikin. A total of 450 spatially varied presentation points were analyzed, each weighted in reference to direction of arrival on the directional microphone. Empiric differences between the DI derived from the 3D-DI method proposed in this investigation and the conventionally derived 2D-DI method DI on a manikin were as large as 3.8 dB in the higher frequencies, depending on the device under test. The magnitude of these differences was dependent on the device under test microphone location. The further the microphone was placed into the ear of the manikin, the larger the empiric differences.

  2. Direct Detection Doppler Lidar for Spaceborne Wind Measurement

    NASA Technical Reports Server (NTRS)

    Korb, C. Laurence; Flesia, Cristina

    1999-01-01

    The theory of double edge lidar techniques for measuring the atmospheric wind using aerosol and molecular backscatter is described. Two high spectral resolution filters with opposite slopes are located about the laser frequency for the aerosol based measurement or in the wings of the Rayleigh - Brillouin profile for the molecular measurement. This doubles the signal change per unit Doppler shift and improves the measurement accuracy by nearly a factor of 2 relative to the single edge technique. For the aerosol based measurement, the use of two high resolution edge filters reduces the effects of background, Rayleigh scattering, by as much as an order of magnitude and substantially improves the measurement accuracy. Also, we describe a method that allows the Rayleigh and aerosol components of the signal to be independently determined. A measurement accuracy of 1.2 m/s can be obtained for a signal level of 1000 detected photons which corresponds to signal levels in the boundary layer. For the molecular based measurement, we describe the use of a crossover region where the sensitivity of a molecular and aerosol-based measurement are equal. This desensitizes the molecular measurement to the effects of aerosol scattering and greatly simplifies the measurement. Simulations using a conical scanning spaceborne lidar at 355 nm give an accuracy of 2-3 m/s for altitudes of 2-15 km for a 1 km vertical resolution, a satellite altitude of 400 km, and a 200 km x 200 km spatial.

  3. A SnO2-samarium doped ceria additional anode layer in a direct carbon fuel cell

    NASA Astrophysics Data System (ADS)

    Yu, Baolong; Zhao, Yicheng; Li, Yongdan

    2016-02-01

    The role of a SnO2-samarium doped ceria (SDC) additional anode layer in a direct carbon fuel cell (DCFC) with SDC-(Li0.67Na0.33)2CO3 composite electrolyte and lithiated NiO-SDC-(Li0.67Na0.33)2CO3 composite cathode is investigated and compared with a NiO-SDC extra anode layer. Catalytic grown carbon fiber mixed with (Li0.67Na0.33)2CO3 is used as a fuel. At 750 °C, the maximum power outputs of 192 and 143 mW cm-2 are obtained by the cells with SnO2-SDC and NiO-SDC layers, respectively. In the SnO2-SDC layer, the reduction of SnO2 and the oxidation of Sn happen simultaneously during the cell operation, and the Sn/SnO2 redox cycle provides an additional route for fuel conversion. The formation of an insulating dense interlayer between the anode and electrolyte layers, which usually happens in DCFCs with metal anodes, is avoided in the cell with the SnO2-SDC layer, and the stability of the cell is improved consequently.

  4. Time-Resolved In Situ Measurements During Rapid Alloy Solidification: Experimental Insight for Additive Manufacturing

    DOE PAGES

    McKeown, Joseph T.; Zweiacker, Kai; Liu, Can; ...

    2016-01-27

    In research and industrial environments, additive manufacturing (AM) of metals and alloys is becoming a pervasive technology, though significant challenges remain before widespread implementation of AM can be realized. In situ investigations of rapid alloy solidification with high spatial and temporal resolutions can provide unique experimental insight into microstructure evolution and kinetics that are relevant for AM processing. Hypoeutectic thin-film Al–Cu and Al–Si alloys were investigated using dynamic transmission electron microscopy to monitor pulsed-laser-induced rapid solidification across microsecond timescales. Solid–liquid interface velocities measured from time-resolved images revealed accelerating solidification fronts in both alloys. We observed microstructure evolution, solidification product, andmore » presence of a morphological instability at the solid–liquid interface in the Al–4 at.%Cu alloy are related to the measured interface velocities and small differences in composition that affect the thermophysical properties of the alloys. These time-resolved in situ measurements can inform and validate predictive modeling efforts for AM.« less

  5. Time-Resolved In Situ Measurements During Rapid Alloy Solidification: Experimental Insight for Additive Manufacturing

    SciTech Connect

    McKeown, Joseph T.; Zweiacker, Kai; Liu, Can; Coughlin, Daniel R.; Clarke, Amy J.; Baldwin, J. Kevin; Gibbs, John W.; Roehling, John D.; Imhoff, Seth D.; Gibbs, Paul J.; Tourret, Damien; Wiezorek, Jörg M. K.; Campbell, Geoffrey H.

    2016-01-27

    In research and industrial environments, additive manufacturing (AM) of metals and alloys is becoming a pervasive technology, though significant challenges remain before widespread implementation of AM can be realized. In situ investigations of rapid alloy solidification with high spatial and temporal resolutions can provide unique experimental insight into microstructure evolution and kinetics that are relevant for AM processing. Hypoeutectic thin-film Al–Cu and Al–Si alloys were investigated using dynamic transmission electron microscopy to monitor pulsed-laser-induced rapid solidification across microsecond timescales. Solid–liquid interface velocities measured from time-resolved images revealed accelerating solidification fronts in both alloys. We observed microstructure evolution, solidification product, and presence of a morphological instability at the solid–liquid interface in the Al–4 at.%Cu alloy are related to the measured interface velocities and small differences in composition that affect the thermophysical properties of the alloys. These time-resolved in situ measurements can inform and validate predictive modeling efforts for AM.

  6. Time-Resolved In Situ Measurements During Rapid Alloy Solidification: Experimental Insight for Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    McKeown, Joseph T.; Zweiacker, Kai; Liu, Can; Coughlin, Daniel R.; Clarke, Amy J.; Baldwin, J. Kevin; Gibbs, John W.; Roehling, John D.; Imhoff, Seth D.; Gibbs, Paul J.; Tourret, Damien; Wiezorek, Jörg M. K.; Campbell, Geoffrey H.

    2016-03-01

    Additive manufacturing (AM) of metals and alloys is becoming a pervasive technology in both research and industrial environments, though significant challenges remain before widespread implementation of AM can be realized. In situ investigations of rapid alloy solidification with high spatial and temporal resolutions can provide unique experimental insight into microstructure evolution and kinetics that are relevant for AM processing. Hypoeutectic thin-film Al-Cu and Al-Si alloys were investigated using dynamic transmission electron microscopy to monitor pulsed-laser-induced rapid solidification across microsecond timescales. Solid-liquid interface velocities measured from time-resolved images revealed accelerating solidification fronts in both alloys. The observed microstructure evolution, solidification product, and presence of a morphological instability at the solid-liquid interface in the Al-4 at.%Cu alloy are related to the measured interface velocities and small differences in composition that affect the thermophysical properties of the alloys. These time-resolved in situ measurements can inform and validate predictive modeling efforts for AM.

  7. Longitudinal and transversal bioimpedance measurements in addition to diagnosis of heart failure

    NASA Astrophysics Data System (ADS)

    Ribas, N.; Nescolarde, L.; Domingo, M.; Gastelurrutia, P.; Bayés-Genis, A.; Rosell-Ferrer, J.

    2010-04-01

    Heart Failure (HF) is a clinical syndrome characterised by signs of systemic and pulmonary fluid retention, shortness of breath and/or fatigue. There is a lack of reliable indicators of disease state. Benefits and applicability of non-invasive bioimpedance measurement in the hydration state of soft tissues have been validated, fundamentally, in dialysis patients. Four impedance configurations (2 longitudinal and 2 transversal) were analyzed in 48 HF patients (M=28, F=20) classified according to a clinical disease severity score (CDSS) derived from the Framingham criteria: CDSS<=2 (G1: M = 23, F = 14) and CDSS>2 (G2: M = 5, F = 6). The aim of this study is to analyze longitudinal and transversal bioimpedance measurement at 50 kHz, in addition to clinical diagnosis parameters of heart failure, including: clinical disease severity score (CDSS) and a biomarker concentrations (NT-proBNP). The Kolmogorov-Smirnov test was used for the normality test of all variables. The CDSS, NTproBNP and impedance parameters between groups (G1 and G2) were compared by mean of Mann Withney U-test. The statistical significance was considered with P < 0.05. Whole-body impedance measured was analyzed using RXc graph.

  8. Histological and biomechanical analysis of porous additive manufactured implants made by direct metal laser sintering: a pilot study in sheep.

    PubMed

    Stübinger, Stefan; Mosch, Isabel; Robotti, Pierfrancesco; Sidler, Michéle; Klein, Karina; Ferguson, Stephen J; von Rechenberg, Brigitte

    2013-10-01

    It was the aim of this study to analyze osseointegrative properties of porous additive manufactured titanium implants made by direct metal laser sintering in a sheep model after an implantation period of 2 and 8 weeks. Three different types of implants were placed in the pelvis of six sheep. In each sheep were placed three standard machined (M), three sandblasted and etched (SE), and three porous additive manufactured (AM) implants. Of these three implants (one per type) were examined histologically and six implants were tested biomechanically. Additionally a semiquantitative histomorphometrical and qualitative fluorescent microscopic analysis were performed. After 2 and 8 weeks bone-to-implant-contact (BIC) values of the AM surface (2w: 20.49% ± 5.18%; 8w: 43.91% ± 9.69%) revealed no statistical significant differences in comparison to the M (2w: 20.33% ± 11.50%; 8w: 25.33% ± 4.61%) and SE (2w: 43.67 ± 12.22%; 8w: 53.33 ± 8.96%) surfaces. AM surface showed the highest increase of the BIC between the two observation time points. Considering the same implantation period histomorphometry and fluorescent labelling disclosed no significant differences in the bone surrounding the three implants groups. In contrast Removal-torque-test showed a significant improve in fixation strength (P ≤ 0.001) for the AM (1891.82 ± 308, 44 Nmm) surface after eight weeks in comparison to the M (198.93±88,04 Nmm) and SE (730.08 ± 151,89 Nmm) surfaces. All three surfaces (M, SE, and AM) showed sound osseointegration. AM implants may offer a possible treatment option in clinics for patients with compromised bone situations. Copyright © 2013 Wiley Periodicals, Inc., a Wiley Company.

  9. The effect of direct addition of iron(III) on anaerobic digestion efficiency and odor causing compounds.

    PubMed

    Park, Chang Min; Novak, John T

    2013-01-01

    The role of iron addition to sewage sludge prior to anaerobic digestion was evaluated to determine the effect of iron on digestion performance and generation of odor-causing compounds. Hydrogen sulfide (H2S) and volatile organic sulfur compounds (VOSCs) were the odorous gases evaluated in this study. Samples were obtained from seven municipal wastewater treatment plants (WWTPs), and batch anaerobic digestion tests were conducted using primary and secondary sludges at 30 day solids retention time (SRT) under mesophilic conditions. Volatile solid removal (VSR) was highly predictable with background iron concentrations measured in the combined sludge. They were likely to increase as influent iron content increased. 1.25% w/w ferric chloride (FeCl3) was added to the anaerobic digester feed in order to simulate iron addition for sulfide control in full-scale WWTPs. The results showed that it had a positive impact on digestion performance with higher VSR and odor control with reduced H2S and TVOSCs in the headspace gas of dewatered biosolids considered in the tests. Ferric chloride is considered a beneficial additive as a strategy for an odor mitigation, not to mention more efficient digestion under anaerobic conditions.

  10. Clinical Application Of The Direct Measurement Of Human Shape

    NASA Astrophysics Data System (ADS)

    Anderson, J.; Vincent, R.; Marks, P.; English, M. J.

    1980-07-01

    A system is described for the recording and measurement of human body shape by a series of circular ultrasound scans. Computer manipulation of the echo data provides a graphic display of body contour, and a measurement of total body surface area and volume. The theoretical resolution for distance measurements using this device is 2.5 mm, a figure achieved in practical calibration experiments using a metal test object. Measurements from the body surface, although less precise, are sufficiently accurate and reproducible to enable useful clinical information to be obtained, particularly in recording the morphological changes associated with obesity and malnutrition.

  11. Residual stress measurements via neutron diffraction of additive manufactured stainless steel 17-4 PH.

    PubMed

    Masoomi, Mohammad; Shamsaei, Nima; Winholtz, Robert A; Milner, Justin L; Gnäupel-Herold, Thomas; Elwany, Alaa; Mahmoudi, Mohamad; Thompson, Scott M

    2017-08-01

    Neutron diffraction was employed to measure internal residual stresses at various locations along stainless steel (SS) 17-4 PH specimens additively manufactured via laser-powder bed fusion (L-PBF). Of these specimens, two were rods (diameter=8 mm, length=80 mm) built vertically upward and one a parallelepiped (8×80×9 mm(3)) built with its longest edge parallel to ground. One rod and the parallelepiped were left in their as-built condition, while the other rod was heat treated. Data presented provide insight into the microstructural characteristics of typical L-PBF SS 17-4 PH specimens and their dependence on build orientation and post-processing procedures such as heat treatment. Data have been deposited in the Data in Brief Dataverse repository (doi:10.7910/DVN/T41S3V).

  12. Internalized Heterosexism: Measurement, Psychosocial Correlates, and Research Directions

    ERIC Educational Resources Information Center

    Szymanski, Dawn M.; Kashubeck-West, Susan; Meyer, Jill

    2008-01-01

    This article provides an integrated critical review of the literature on internalized heterosexism/internalized homophobia (IH), its measurement, and its psychosocial correlates. It describes the psychometric properties of six published measures used to operationalize the construct of IH. It also critically reviews empirical studies on correlates…

  13. Direct Measurement of {sup 21}Na+{alpha} Stellar Reaction

    SciTech Connect

    Binh, D. N.; Kubono, S.; Yamaguchi, H.; Hayakawa, S.; Hashimoto, T.; Kahl, D.; Teranishi, T.; Iwasa, N.; Kume, N.; Kato, S.; Khiem, L. H.; Tho, N. T.; Wakabayashi, Y.

    2010-08-12

    The measurement of the resonant alpha scattering and the {sup 21}Na({alpha}, p) reaction were performed for the first time in inverse kinematics with the thick target method using a {sup 21}Na radioisotope (RI) beam. This paper reports the current result of alpha scattering measurement and its astrophysics implication.

  14. A self-decoupling piezoresistive sensor for measuring microforce in horizontal and vertical directions

    NASA Astrophysics Data System (ADS)

    Zhou, Jie; Rong, Weibin; Wang, Lefeng; Gao, Peng; Sun, Lining

    2016-09-01

    This paper presents the design, fabrication and calibration of a novel two-dimension microforce sensor with nano-Newton resolution. The sensor, mainly composed of a clamped-clamped beam (horizontal detecting beam), an overhanging beam (vertical detecting beam) and a half-folded beam, is highly sensitive to microforces in the horizontal (parallel to the probe of the designed sensor) and vertical (perpendicular to the wafer surface) directions. The four vertical sidewall surface piezoresistors (horizontal piezoresistors) and two surface piezoresistors (vertical piezoresistors) were fabricated to achieve the requirements of two-dimension microforce measurements. Combining the sensor structure with Wheatstone bridge configurations, the microforce decoupling among the x, y, and z direction can be realized. Accordingly, the sensor is capable of detecting microforces in the horizontal and vertical directions independently. The calibration results verified that the sensor sensitivities at room temperature are 210.58 V N-1and 159.2 V N-1 in the horizontal and vertical directions, respectively. Additionally, the sensor’s corresponding force resolutions are estimated at 2 nN and 3 nN in theory, respectively. The sensor can be used to measure the contact force between manipulating tools and micro-objects, in fields such as microassembly and biological assays.

  15. A direct measurement of microviscoelasticity using optical tweezers

    NASA Astrophysics Data System (ADS)

    Valentine, M. T.; Ou-Yang, H. D.

    1997-03-01

    We report our measurements of viscosity and elasticity of the microenvironment of an associated polymer solution. We measure, using position sensitive detection and lock-in technique, the phase of one polystyrene sphere moving in forced oscillation by the optical tweezers. This technique is unique in its use of phase measurements, which carry all the information needed to find viscosity and elasticity. By measuring phase shift as a function of frequency, we can find a coupled visco-elastic term, the components of which can be separated by varying laser intensity (and therefore trap strength) and recording the resulting phase. Upon calibration with a solution of known viscosity, we can independently measure the viscosity and elasticity of the microenvironment.

  16. Monitoring the junction temperature of an IGBT through direct measurement using a fiber Bragg grating

    NASA Astrophysics Data System (ADS)

    Bazzo, João P.; Lukasievicz, Tiago; Vogt, Marcio; de Oliveira, Valmir; Kalinowski, Hypolito J.; Cardozo da Silva, Jean Carlos

    2011-05-01

    This paper proposes a new technique to monitor the junction temperature of an insulated gate bipolar transistor (IGBT) through direct measurement using an optical fiber sensor mounted on the chip structure. Some features of the sensor such as electromagnetic immunity, small size and fast response time allow the identification of temperature changes generated by the energy loss during device operation. In addition to the online monitoring of the junction temperature, results show the thermal characteristics of the IGBT, which can be used to develop an accurate model to simulate the heat generated during the device conduction and switching processes.

  17. Time- and isomer-resolved measurements of sequential addition of acetylene to the propargyl radical

    DOE PAGES

    Savee, John D.; Selby, Talitha M.; Welz, Oliver; ...

    2015-10-06

    Soot formation in combustion is a complex process in which polycyclic aromatic hydrocarbons (PAHs) are believed to play a critical role. Recent works concluded that three consecutive additions of acetylene (C2H2) to propargyl (C3H3) create a facile route to the PAH indene (C9H8). However, the isomeric forms of C5H5 and C7H7 intermediates in this reaction sequence are not known. We directly investigate these intermediates using time- and isomer-resolved experiments. Both the resonance stabilized vinylpropargyl (vp-C5H5) and 2,4-cyclopentadienyl (c-C5H5) radical isomers of C5H5 are produced, with substantially different intensities at 800 K vs 1000 K. In agreement with literature master equationmore » calculations, we find that c-C5H5 + C2H2 produces only the tropyl isomer of C7H7 (tp-C7H7) below 1000 K, and that tp-C7H7 + C2H2 terminates the reaction sequence yielding C9H8 (indene) + H. Lastly, this work demonstrates a pathway for PAH formation that does not proceed through benzene.« less

  18. Direct measurement of the inertial confinement time in a magnetically driven implosion

    NASA Astrophysics Data System (ADS)

    Knapp, P. F.; Martin, M. R.; Dolan, D. H.; Cochrane, K.; Dalton, D.; Davis, J.-P.; Jennings, C. A.; Loisel, G. P.; Romero, D. H.; Smith, I. C.; Yu, E. P.; Weis, M. R.; Mattsson, T. R.; McBride, R. D.; Peterson, K.; Schwarz, J.; Sinars, D. B.

    2017-04-01

    We report on direct, radiographic measurement of the stagnation phase of a magnetically driven liner implosion. The liner is filled with liquid deuterium and imploded to a minimum radius of 440 μ m (radial convergence ratio of 7.7) over 300 ns, achieving a density of ≈10 g/cm 3 . The measured confinement time is ≈14 ns, compared to 16 ns from 1D simulations. A comparison of measured density profiles with 1D and 2D simulations shows a deviation in the reflected shock trajectory and the liner areal density. Additionally, the magneto Rayleigh-Taylor instability causes enhanced compression with shorter confinement in the bubble region compared to the spikes. These effects combine to reduce the pressure-confinement time product, P τ , by 25% compared to the simulations.

  19. Direct measurement of sediment sound speed in Shallow Water '06.

    PubMed

    Yang, Jie; Tang, Dajun; Williams, Kevin L

    2008-09-01

    Knowledge of sediment sound speed is crucial for predicting sound propagation. During the Shallow Water '06 experiment, in situ sediment sound speed was measured using the Sediment Acoustic-speed Measurement System (SAMS). SAMS consists of ten fixed sources and one receiver that can reach a maximal sediment depth of 3 m. Measurements were made in the frequency range 2-35 kHz. Signal arrival times and propagation distances were recorded, from which sediment sound speed was determined. Preliminary results from three deployments show that SAMS was capable of determining sediment sound speed with uncertainties less than 1.6%. Little dispersion in sediment sound speed was observed.

  20. Direct measurement of middle ear pressure through the eustachian tube.

    PubMed

    Takahashi, H; Hayashi, M; Honjo, I

    1987-01-01

    We report a method for measuring middle ear pressure through the eustachian tube. We used a 1-mm-diameter micro-tip catheter pressure transducer (Mikro-tip) and inserted this into the tympanic cavity through the eustachian tube. In preliminary studies, we measured four normal ears, two ears with tubal dysfunction, one ear with a dry perforation and 13 ears with otitis media with effusion (OME). Among those ears with OME, three showed negative middle ear pressure, three slight positive pressure and one normal pressure. These findings suggest that our transtubal method is reliable and useful for measuring middle ear pressure.

  1. A direct measurement of shear fracture energy in rocks

    NASA Astrophysics Data System (ADS)

    Cox, S. J. D.; Scholz, C. H.

    Shear fracture energy has been measured for a granite and a limestone using a torsional method. We monitor failure with periodic stiffness determinations and measure strain energy released by integrating the load-displacement record. Values of strain energy release rate (G3C) obtained for zero normal stress lie in the range 10²-10³ Jm-2. These fall between the values of G1C from tensile experiments and of shear fracture energy measured under high normal stress in triaxial tests.

  2. Nonlinearity measurements of solar cells with an LED-based combinatorial flux addition method

    PubMed Central

    Hamadani, Behrang H.; Shore, Andrew; Roller, John; Yoon, Howard W; Campanelli, Mark

    2016-01-01

    We present a light emitting diode (LED)-based system utilizing a combinatorial flux addition method to investigate the nonlinear relationship in solar cells between the output current of the cell and the incident irradiance level. The magnitude of the light flux is controlled by the supplied currents to two LEDs (or two sets of them) in a combinatorial fashion. The signals measured from the cell are arranged within a related overdetermined linear system of equations derived from an appropriately chosen Nth degree polynomial representing the relationship between the measured signals and the incident fluxes. The flux values and the polynomial coefficients are then solved for by linear least squares to obtain the best fit. The technique can be applied to any solar cell, under either monochromatic or broadband spectrum. For the unscaled solution, no reference detectors or prior calibrations of the light flux are required. However, if at least one calibrated irradiance value is known, then the entire curve can be scaled to an appropriate spectral responsivity value. Using this technique, a large number of data points can be obtained in a relatively short time scale over a large signal range. PMID:27524837

  3. Nonlinearity measurements of solar cells with an LED-based combinatorial flux addition method.

    PubMed

    Hamadani, Behrang H; Shore, Andrew; Roller, John; Yoon, Howard W; Campanelli, Mark

    2016-02-01

    We present a light emitting diode (LED)-based system utilizing a combinatorial flux addition method to investigate the nonlinear relationship in solar cells between the output current of the cell and the incident irradiance level. The magnitude of the light flux is controlled by the supplied currents to two LEDs (or two sets of them) in a combinatorial fashion. The signals measured from the cell are arranged within a related overdetermined linear system of equations derived from an appropriately chosen N(th) degree polynomial representing the relationship between the measured signals and the incident fluxes. The flux values and the polynomial coefficients are then solved for by linear least squares to obtain the best fit. The technique can be applied to any solar cell, under either monochromatic or broadband spectrum. For the unscaled solution, no reference detectors or prior calibrations of the light flux are required. However, if at least one calibrated irradiance value is known, then the entire curve can be scaled to an appropriate spectral responsivity value. Using this technique, a large number of data points can be obtained in a relatively short time scale over a large signal range.

  4. Direct measurements of in-stream nitrate uptake with automated high frequency sensors

    NASA Astrophysics Data System (ADS)

    Kunz, Julia Vanessa; Hensley, Robert; Brase, Lisa; Borchardt, Dietrich; Rode, Michael

    2016-04-01

    Decades of nutrient studies have unveiled the importance of river networks in nutrient cycling. Still, direct methods to quantify instream removal in defined reaches have so far been limited to small streams. In rivers, where isotope tracer additions have been impracticable, uptake rates could only very rarely be measured and therefore have been mostly modelled by upscaling. Recently, the expanding availability of high resolution stream solute signals from automated sensors offers new possibilities for uptake kinetic studies. Cohen et al (2012) assessed assimilation and denitrification rates based on daily nitrate amplitudes and longitudinal concentration gradients in spring- fed chemostatic rivers. In higher order streams, overlapping of network, onsite and upstream signals require additional conceptual and methodological adaptation. Here we present a new combined longitudinal lagrangian and mass balance approach with continuous measurements of nitrate uptake rates in the German lowland river Weiße Elster, to our knowledge the first direct measurement of nitrate kinetics with continues high frequency sensors. We used 10 minutes time step NO3-N, pH, specific conductivity, dissolved oxygen, temperature and chlorophyl-a measurements and supplementing low frequency 15N isotope manual sampling. Longitudinal lagrangian measurements were conducted during day and night. Our data from two morphologically highly contrasting reaches indicate that local, seasonal or even day to day changes in uptake kinetics can be of several orders of magnitude and that the disregard of intermediate storage and dispersion can lead to high errors. The natural river reach revealed considerably higher N uptake than the channelized river reach. Furthermore, river bottom related N-uptake rates were in the same order than those found in agricultural head water streams. Besides depicting prospects and limits, we also provide important considerations for the set-up of measurement stations and for

  5. Direct measurement of fluence rate in the human brain

    NASA Astrophysics Data System (ADS)

    Melnik, Ivan S.; Rusina, Tatyana V.; Denisov, Nikolay A.; Dets, Sergiy M.; Steiner, Rudolf W.; Rozumenko, Vladimir D.

    1996-01-01

    Fluence rate was measured in normal and cancerous (glioma) human brain samples using a multichannel detector. Detector consisted of 8 isotrope fiber probes positioned around the central irradiating probe. Detecting probes were displaced one from other at a step 0.5 mm along the central irradiating fiber. Bare ends of detecting fibers were coupled with photodiode array. He-Ne (633 nm) or Nd:YAG (1064 nm) lasers were coupled with irradiating probe. Fluence rate was measured in each of 8 points in the depth range 5 mm. Measured mean penetration depths of 633 nm light were 0.70 mm, 0.50 mm and 0.40 mm for white matter, grey matter and glioma, respectively. For Nd:YAG laser, penetration depth was about 2.3 mm for normal tissue and glioma. Multichannel computerized detector allows to provide a small invasive real-time measurements of fluence rate in different tissues.

  6. Direct Probe Mounted High-Performance Amplifiers for Pulsed Measurement

    SciTech Connect

    Wartenbe, Mark; Stegen, Zachary; McDonald, Ross David; Balakirev, Fedor F.

    2014-01-07

    High electrical noise and short time scales of pulsed magnets create significant challenges for electrical measurements, particularly in the sub-MHz frequency window, where bulk of the transport measurements is routinely conducted. The proper design of the first stage of signal conditioning and amplification is the critical step in increasing sensitivity of the measurements in such a harsh environment. We developed a custom instrumentation amplifier to implement a number of noise-reducing features for pulsed field measurements. The amplifier utilizes single-chip design based on recently released AD8421 [1]. The preamp design has proven to be successful and is now being implemented on a variety of probes. The design is continuously being revised and updated as better preamp chips become available.

  7. Direct Comparisons of Radiances Measured by Independent Contemporary ERB Instruments

    NASA Technical Reports Server (NTRS)

    Haeffelin, Martial; Wielicki, Bruce; Priestley, Kory; Duvel, Jean Philippe; Viollier, Michel

    2001-01-01

    Comparisons of radiance measurements from overlapping independent Earth and cloud radiation budget (ERB) missions are an important contribution to the validation process of the these missions and are essential to the construction of a consistent long-term record of ERB observations. Measurements from the CERES instrument on TRMM are compared to ScaRaB on Resurs (Jan-Mar 1999) and CERES on Terra (Mar-Apr 2000).

  8. Direct Measurement of Lateral Force Using Dual Cantilevers

    PubMed Central

    Ishikawa, Makoto; Ichikawa, Masaya; Miura, Kouji

    2012-01-01

    We have constructed an experimental system to measure a piconewton lateral force using dual cantilevers which cross with each other. The resolution of the lateral force is estimated to be 3.3 p ± 0.2 pN, which is comparable to forces due to thermal fluctuation. This experimental apparatus works so easily that it will enable us to determine forces during nano-manipulation and nano-tribological measurements. PMID:22737001

  9. Patterning of nanodiamond tracks and nanocrystalline diamond films using a micropipette for additive direct-write processing.

    PubMed

    Taylor, Alice C; Edgington, Robert; Jackman, Richard B

    2015-04-01

    The ability to pattern the seeding of nanodiamonds (NDs), and thus selectively control areas of diamond growth, is a useful capability for many applications, including photonics, microelectromechanical systems (MEMS) prototyping, and biomaterial design. A microprinting technique using a computer-driven micropipette has been developed to deposit patterns of ND monolayers from an unreactive water/glycerol ND ink to 5-μm resolution. The concentration and composition of the ND solution were optimized to realize high-density monolayers of NDs and consistent ND printing. Subsequent nanocrystalline diamond (NCD) patterns grown using chemical vapor deposition showed a high level of compliance with the printed ND pattern. This "direct-write", bottom-up, and additive process offers a versatile and simple alternative to pattern diamond. The process has the particular advantage that it does not require lithography or destructive processing such as reactive-ion etching (RIE) and, pertinently, does not involve reactive chemicals that could alter the surface chemistry of NDs. Furthermore, given that this process obviates the use of conventional lithography, substrates that are not suitable for lithographic processing (e.g., excessively small or three-dimensional structured substrates) can be inscribed with ND patterns. The technique also allows for the growth of discrete, localized, single-crystal nanodiamonds with applications in quantum technology.

  10. Evolution of the additive genetic variance–covariance matrix under continuous directional selection on a complex behavioural phenotype

    PubMed Central

    Careau, Vincent; Wolak, Matthew E.; Carter, Patrick A.; Garland, Theodore

    2015-01-01

    Given the pace at which human-induced environmental changes occur, a pressing challenge is to determine the speed with which selection can drive evolutionary change. A key determinant of adaptive response to multivariate phenotypic selection is the additive genetic variance–covariance matrix (G). Yet knowledge of G in a population experiencing new or altered selection is not sufficient to predict selection response because G itself evolves in ways that are poorly understood. We experimentally evaluated changes in G when closely related behavioural traits experience continuous directional selection. We applied the genetic covariance tensor approach to a large dataset (n = 17 328 individuals) from a replicated, 31-generation artificial selection experiment that bred mice for voluntary wheel running on days 5 and 6 of a 6-day test. Selection on this subset of G induced proportional changes across the matrix for all 6 days of running behaviour within the first four generations. The changes in G induced by selection resulted in a fourfold slower-than-predicted rate of response to selection. Thus, selection exacerbated constraints within G and limited future adaptive response, a phenomenon that could have profound consequences for populations facing rapid environmental change. PMID:26582016

  11. Evolution of the additive genetic variance-covariance matrix under continuous directional selection on a complex behavioural phenotype.

    PubMed

    Careau, Vincent; Wolak, Matthew E; Carter, Patrick A; Garland, Theodore

    2015-11-22

    Given the pace at which human-induced environmental changes occur, a pressing challenge is to determine the speed with which selection can drive evolutionary change. A key determinant of adaptive response to multivariate phenotypic selection is the additive genetic variance-covariance matrix ( G: ). Yet knowledge of G: in a population experiencing new or altered selection is not sufficient to predict selection response because G: itself evolves in ways that are poorly understood. We experimentally evaluated changes in G: when closely related behavioural traits experience continuous directional selection. We applied the genetic covariance tensor approach to a large dataset (n = 17 328 individuals) from a replicated, 31-generation artificial selection experiment that bred mice for voluntary wheel running on days 5 and 6 of a 6-day test. Selection on this subset of G: induced proportional changes across the matrix for all 6 days of running behaviour within the first four generations. The changes in G: induced by selection resulted in a fourfold slower-than-predicted rate of response to selection. Thus, selection exacerbated constraints within G: and limited future adaptive response, a phenomenon that could have profound consequences for populations facing rapid environmental change.

  12. Methane emissions measured directly from grazing livestock in New Zealand

    NASA Astrophysics Data System (ADS)

    Lassey, Keith R.; Ulyatt, Marcus J.; Martin, Ross J.; Walker, Carolyn F.; David Shelton, I.

    We report measurements of methane emissions from individual ruminant livestock-both sheep and dairy cows-grazing pasture typical of New Zealand lowlands in the temperate southwest Pacific. These are the first measurements reported from grazing sheep, and among the first from grazing cattle. The measurement technique, developed at Washington State University, enables emission rates to be determined from analyses of "breath" samples collected while grazing. More than 250 measurements of daily methane emission from 50 sheep (8 months old) were made, with flock-mean emission 18.9 ± 0.8 g hd -1 d -1. Although emissions were weakly correlated with feed intake, they represented a 4.6 ± 0.1 % average loss of gross dietary energy. The corresponding mean emission based on 40 measurements of daily emissions from 10 lactating dairy cows was 263 ± 10 g hd -1 d -1, approximately 6.2% of estimated gross energy intake. A notable feature was the large inter-sheep variability in daily methane emission (factor of 1.4 range) that could not be attributed to variable intake. This would appear to suggest an appreciable diversity of methanogenetic response to digestion, and may be significant in the search for strategies to control emissions of this greenhouse gas.

  13. Direct measurement of surface carbon concentrations. [in lunar soil

    NASA Technical Reports Server (NTRS)

    Filleux, C.; Tombrello, T. A.; Burnett, D. S.

    1977-01-01

    Measurements of surface concentrations of carbon in lunar soils and soil breccias provide information on the origin of carbon in the regolith. The reaction C-12 (d, p sub zero) is used to measure 'surface' and 'volume' concentrations in lunar samples. This method has a depth resolution of 1 micron, which permits only a 'surface' and a 'volume' component to be measured. Three of four Apollo 16 double drive tube samples show a surface carbon concentration of about 8 by 10 to the 14th power/sq cm, whereas the fourth sample gave 4 by 10 to the 14th power/sq cm. It can be convincingly shown that the measured concentration does not originate from fluorocarbon or hydrocarbon contaminants. Surface adsorbed layers of CO or CO2 are removed by a sputter cleaning procedure using a 2-MeV F beam. It is shown that the residual C concentration of 8 by 10 to the 14th power/sq cm cannot be further reduced by increased F fluence, and it is therefore concluded that it is truly lunar. If one assumes that the measured surface C concentration is a steady-state concentration determined only by a balance between solar-wind implantation and sputtering, a sputter erosion rate of 0.1 A/yr is obtained. However, it would be more profitable to use an independently derived sputter erosion rate to test the hypothesis of a solar-wind origin of the surface carbon.

  14. Direct measurement of surface carbon concentrations. [in lunar soil

    NASA Technical Reports Server (NTRS)

    Filleux, C.; Tombrello, T. A.; Burnett, D. S.

    1977-01-01

    Measurements of surface concentrations of carbon in lunar soils and soil breccias provide information on the origin of carbon in the regolith. The reaction C-12 (d, p sub zero) is used to measure 'surface' and 'volume' concentrations in lunar samples. This method has a depth resolution of 1 micron, which permits only a 'surface' and a 'volume' component to be measured. Three of four Apollo 16 double drive tube samples show a surface carbon concentration of about 8 by 10 to the 14th power/sq cm, whereas the fourth sample gave 4 by 10 to the 14th power/sq cm. It can be convincingly shown that the measured concentration does not originate from fluorocarbon or hydrocarbon contaminants. Surface adsorbed layers of CO or CO2 are removed by a sputter cleaning procedure using a 2-MeV F beam. It is shown that the residual C concentration of 8 by 10 to the 14th power/sq cm cannot be further reduced by increased F fluence, and it is therefore concluded that it is truly lunar. If one assumes that the measured surface C concentration is a steady-state concentration determined only by a balance between solar-wind implantation and sputtering, a sputter erosion rate of 0.1 A/yr is obtained. However, it would be more profitable to use an independently derived sputter erosion rate to test the hypothesis of a solar-wind origin of the surface carbon.

  15. Direct Measurements of Edge Diffraction from Soft Underwater Acoustic Panels

    DTIC Science & Technology

    1994-06-01

    AD- A 2 83 198 UMENTATION PAGE Form Approved rn eu to h ou r P er 0 in~ g d w * ii. fat re wle 0O M B N o . 0 7 0 4 - 1 8 8 = "rt W o00MoG&t of...SPONSORING/MONITORING ]k• •.,(•. t z ,. .•AGENCY REPORT NUMBER OFFICE OF NAVAL RESEARCH 1 AGENC REOR NUM- BOER 800 N. QUINCY ST. WSL 2 - ARLINGTON, VA 22217...kHz. (a) Directly radiated waveform. This waveform was captured with the bydrophone (b) ( O ) situated at the nominal 5-cm oflet positioa however, the

  16. Direct Measurements of Torque During Holliday Junction Migration

    PubMed Central

    Forth, Scott; Deufel, Christopher; Patel, Smita S.; Wang, Michelle D.

    2011-01-01

    DNA experiences torsional stress resulting from the activities of motor enzymes and bound proteins. The mechanisms by which this torsional stress is dissipated to maintain DNA structural integrity are not fully known. Here, we show that a Holliday junction can limit torsion by coupling rotation to translocation and torque to force. The torque required to mechanically migrate through individual junctions was found to be an order of magnitude smaller than that required to melt DNA. We also directly show that substantially more torque was required to migrate through even a single-base sequence heterology, which has important implications for the activity of junction-migrating enzymes. PMID:21767475

  17. Direct LSC method for measurements of biofuels in fuel.

    PubMed

    Krištof, Romana; Logar, Jasmina Kožar

    2013-07-15

    Direct liquid scintillation counting (LSC) for quantification of biofuels content in fuels was implemented and validated on three liquid fossil fuel matrices-ethanol, gasoline and diesel. Fatty acid methyl esters (FAMEs), hydrogenated vegetable oils (HVO) and bio-ethanol were used as biofuels. The method is applicable in the range up to 100% for all tested combinations of bio components. The sensitivity and precision of the method are suitable for determination of bio component content in the blends which is appearing on the global market. The method does not require special equipment for sample preparation. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. A direct measurement of the winter helium bulge

    NASA Technical Reports Server (NTRS)

    Mauersberger, K.; Potter, W. E.; Kayser, D. C.

    1976-01-01

    In late December 1975, the orbital configuration of the Atmosphere Explorer-D satellite made possible the measurement of the winter helium bulge within a single perigee pass. Shortly after the winter solstice, the perigee of the polar-orbiting AE-D satellite crossed the equator, at which time descending and ascending portions of the orbit stretched symmetrically over the Southern and Northern Hemispheres. The open-source neutral mass spectrometer (OSS) on board AE-D measured helium densities between the perigee (about 150 km) and altitudes of 650 km. During the time the perigee was at the equator, altitudes above approximately 550 km were located north and south at latitudes greater than 50-deg. Helium showed, in the winter hemisphere, densities that were a factor of 20 higher than at corresponding altitudes and latitudes in the Southern (summer) Hemisphere. Absolute densities of helium agree well with previous measurements.

  19. Direct measurements of drag forces in C. elegans crawling locomotion.

    PubMed

    Rabets, Yegor; Backholm, Matilda; Dalnoki-Veress, Kari; Ryu, William S

    2014-10-21

    With a simple and versatile microcantilever-based force measurement technique, we have probed the drag forces involved in Caenorhabditis elegans locomotion. As a worm crawls on an agar surface, we found that substrate viscoelasticity introduces nonlinearities in the force-velocity relationships, yielding nonconstant drag coefficients that are not captured by original resistive force theory. A major contributing factor to these nonlinearities is the formation of a shallow groove on the agar surface. We measured both the adhesion forces that cause the worm's body to settle into the agar and the resulting dynamics of groove formation. Furthermore, we quantified the locomotive forces produced by C. elegans undulatory motions on a wet viscoelastic agar surface. We show that an extension of resistive force theory is able to use the dynamics of a nematode's body shape along with the measured drag coefficients to predict the forces generated by a crawling nematode.

  20. Direct and alignment-insensitive measurement of cantilever curvature

    SciTech Connect

    Hermans, Rodolfo I.; Aeppli, Gabriel; Bailey, Joe M.

    2013-07-15

    We analytically derive and experimentally demonstrate a method for the simultaneous measurement of deflection for large arrays of cantilevers. The Fresnel diffraction patterns of a cantilever independently reveal tilt, curvature, cubic, and higher order bending of the cantilever. It provides a calibrated absolute measurement of the polynomial coefficients describing the cantilever shape, without careful alignment and could be applied to several cantilevers simultaneously with no added complexity. We show that the method is easily implemented, works in both liquid media and in air, for a broad range of displacements and is especially suited to the requirements for multi-marker biosensors.

  1. Direct measurements of neutral wave characteristics in the thermosphere

    NASA Technical Reports Server (NTRS)

    Potter, W. E.; Kayser, D. C.; Mauersberger, K.

    1976-01-01

    The elliptical and circular phases of the Atmosphere Explorer-C satellite have provided the basis for a study of the neutral wave characteristics in the thermosphere using data collected by the open source mass spectrometer used to measure both reactive (O,N) and nonreactive (O2, N2, He, Ar) constituents. The phase relationships between the constituents are discussed and the results of a wave occurrence and amplitude survey covering 338 despun orbits in which the local time and latitude characteristics of the waves are presented are discussed. Conclusions based on this survey are tested in a study of waves measured at high latitudes during a geomagnetic storm.

  2. Measurement in Service Businesses: Challenges and Future Directions

    NASA Astrophysics Data System (ADS)

    Tyagi, Rajesh Kumar

    This chapter presents challenges faced by service businesses while implementing a measurement system. A review of existing frameworks is presented and a new framework, the Service Scorecard, is introduced. The Service Scorecard is an adaptation of the Six Sigma Business Scorecard for the service sector. The framework has also been influenced by existing frameworks such as the Malcom Baldrige award criteria, the Balanced Scorecard, the European Quality award and the Service Profit Chain model. The seven elements of the Service Scorecard are Growth, Leadership, Acceleration, Collaboration, Innovation, Execution, and Retention. The examples of measurement systems are presented with concrete real-world case examples. Final thoughts and the challenges faced are also presented.

  3. Influences of reference plane and direction of measurement on eye aberration measurement

    NASA Astrophysics Data System (ADS)

    Atchison, David A.; Charman, W. Neil

    2005-12-01

    We explored effects of measurement conditions on wave aberration estimates for uncorrected, axially myopic model eyes. Wave aberrations were initially referenced to either the anterior corneal pole or the natural entrance pupil of symmetrical eye models, with rays traced into the eye from infinity (into the eye) to simulate normal vision, into the eye from infinity and then back out of the eye from the retinal intercepts (into/out of the eye), or out of the eye from the retinal fovea (out of the eye). The into-the-eye and out-of-the-eye ray traces gave increases in spherical aberration as myopia increased, but the into/out-of-the-eye ray trace showed little variation in spherical aberration. Reference plane choice also affected spherical aberration. Corresponding residual aberrations were calculated after the models had been optically corrected, either by placing the object or image plane at the paraxial far point or by modifying corneas to simulate laser ablation corrections. Correcting aberrations by ablation was more complete if the original aberrations were referenced to the cornea rather than to the entrance pupil. For eyes corrected by spectacle lenses, failure to allow for effects of pupil magnification on apparent entrance pupil diameter produced larger changes in measured aberrations. The general findings regarding choice of reference plane and direction of measurement were found to be equally applicable to eyes that lacked rotational symmetry.

  4. The Measure of Human Error: Direct and Indirect Performance Shaping Factors

    SciTech Connect

    Ronald L. Boring; Candice D. Griffith; Jeffrey C. Joe

    2007-08-01

    The goal of performance shaping factors (PSFs) is to provide measures to account for human performance. PSFs fall into two categories—direct and indirect measures of human performance. While some PSFs such as “time to complete a task” are directly measurable, other PSFs, such as “fitness for duty,” can only be measured indirectly through other measures and PSFs, such as through fatigue measures. This paper explores the role of direct and indirect measures in human reliability analysis (HRA) and the implications that measurement theory has on analyses and applications using PSFs. The paper concludes with suggestions for maximizing the reliability and validity of PSFs.

  5. A method for direct measurement of protein stability in vivo.

    PubMed

    Ignatova, Zoya; Gierasch, Lila M

    2009-01-01

    The stability of proteins is tuned by evolution to enable them to perform their cellular functions for the success of an organism. Yet, most of the arsenal of biophysical techniques at our disposal to characterize the thermodynamic stability of proteins is limited to in vitro samples. We describe an approach that we have developed to observe a protein directly in a cell and to monitor a fluorescence signal that reports the unfolding transition of the protein, yielding quantitatively interpretable stability data in vivo. The method is based on incorporation of structurally nonperturbing, specific binding motifs for a bis-arsenical fluorescein derivative in sites that result in dye fluorescence differences between the folded and unfolded states of the protein under study. This fluorescence labeling approach makes possible the determination of thermodynamic stability by direct urea titration in Escherichia coli cells. The specific case study we describe was carried out on the predominantly beta-sheet intracellular lipid-binding protein, cellular retinoic acid-binding protein (CRABP), expressed in E. coli.

  6. Calibration of Instruments for Measuring Wind Velocity and Direction

    NASA Technical Reports Server (NTRS)

    Vogler, Raymond D.; Pilny, Miroslav J.

    1950-01-01

    Signal Corps wind equipment AN/GMQ-1 consisting of a 3-cup anemometer and wind vane was calibrated for wind velocities from 1 to 200 miles per hour. Cup-shaft failure prevented calibration at higher wind velocities. The action of the wind vane was checked and found to have very poor directional accuracy below a velocity of 8 miles per hour. After shaft failure was reported to the Signal Corps, the cup rotors were redesigned by strengthening the shafts for better operation at high velocities. The anemometer with the redesigned cup rotors was recalibrated, but cup-shaft failure occurred again at a wind velocity of approximately 220 miles per hour. In the course of this calibration two standard generators were checked for signal output variation, and a wind-speed meter was calibrated for use with each of the redesigned cup rotors. The variation of pressure coefficient with air-flow direction at four orifices on a disk-shaped pitot head was obtained for wind velocities of 37.79 53.6, and 98.9 miles per hour. A pitot-static tube mounted in the nose of a vane was calibrated up to a dynamic pressure of 155 pounds per square foot, or approximately 256 miles per hour,

  7. A more direct measure of supernova rates in starburst galaxies

    NASA Technical Reports Server (NTRS)

    Van Buren, Dave; Greenhouse, Matthew A.

    1994-01-01

    We determine ages for young supernova remnants in the starburst galaxies M82 and NGC 253 by applying Chevalier's model for radio emission from supernova blast waves expanding into the ejecta of their precursor stars. Absolute ages are determined by calibrating the model with radio observations of Cas A. We derive supernova rates of 0.10 and 0.08/yr for M82 and NGC 253, respectively. Assuming L (sub FIR) to be proportional to the supernova rate, we find r(sub SN) approximately equal 2 x 10(exp -12) x L(sub FIR), solar yr(exp -1) for these archetypal starburst galaxies. This approach is unique in that the supernova rate is derived from direct observation of supernova remnants rather than from star formation rates and an assumed initial mass function (IMF). We suggest that the approach presented here can be used to derive star-formation rates that are more directly related to observable quantities than those derived by other methods. We find that the supernova rate, far infrared (FIR) luminosity, and dynamical mass of the M82 starburst place few constraints on the initial mass function (IMF) slope and mass limits.

  8. Time- and isomer-resolved measurements of sequential addition of acetylene to the propargyl radical

    SciTech Connect

    Savee, John D.; Selby, Talitha M.; Welz, Oliver; Taatjes, Craig A.; Osborn, David L.

    2015-10-06

    Soot formation in combustion is a complex process in which polycyclic aromatic hydrocarbons (PAHs) are believed to play a critical role. Recent works concluded that three consecutive additions of acetylene (C2H2) to propargyl (C3H3) create a facile route to the PAH indene (C9H8). However, the isomeric forms of C5H5 and C7H7 intermediates in this reaction sequence are not known. We directly investigate these intermediates using time- and isomer-resolved experiments. Both the resonance stabilized vinylpropargyl (vp-C5H5) and 2,4-cyclopentadienyl (c-C5H5) radical isomers of C5H5 are produced, with substantially different intensities at 800 K vs 1000 K. In agreement with literature master equation calculations, we find that c-C5H5 + C2H2 produces only the tropyl isomer of C7H7 (tp-C7H7) below 1000 K, and that tp-C7H7 + C2H2 terminates the reaction sequence yielding C9H8 (indene) + H. Lastly, this work demonstrates a pathway for PAH formation that does not proceed through benzene.

  9. Direct adhesive measurements between wood biopolymer model surfaces.

    PubMed

    Gustafsson, Emil; Johansson, Erik; Wågberg, Lars; Pettersson, Torbjörn

    2012-10-08

    For the first time the dry adhesion was measured for an all-wood biopolymer system using Johnson-Kendall-Roberts (JKR) contact mechanics. The polydimethylsiloxane hemisphere was successfully surface-modified with a Cellulose I model surface using layer-by-layer assembly of nanofibrillated cellulose and polyethyleneimine. Flat surfaces of cellulose were equally prepared on silicon dioxide substrates, and model surfaces of glucomannan and lignin were prepared on silicon dioxide using spin-coating. The measured work of adhesion on loading and the adhesion hysteresis was found to be very similar between cellulose and all three wood polymers, suggesting that the interaction between these biopolymers do not differ greatly. Surface energy calculations from contact angle measurements indicated similar dispersive surface energy components for the model surfaces. The dispersive component was dominating the surface energy for all surfaces. The JKR work of adhesion was lower than that calculated from contact angle measurements, which partially can be ascribed to surface roughness of the model surfaces and overestimation of the surface energies from contact angle determinations.

  10. Relationships among Projective and Direct Verbal Measures of Achievement Motivation.

    ERIC Educational Resources Information Center

    Singh, Satvir

    1979-01-01

    The ways in which projective and nonprojective verbal measures of achievement motivation elicit comparable and dissimilar responses in a "Third World" sample of entrepreneurs and farmers were explored as a test of McClelland's theory of economic growth. Results were generally consistent with the theory of achievement motivation.…

  11. New Directions in Mass Communications Research: Physiological Measurement.

    ERIC Educational Resources Information Center

    Fletcher, James E.

    Psychophysiological research into the effects of mass media, specifically the music of the masses, promises increased insight into the control the media exert on all their consumers. Attention and retention of mass media messages can be tested by measuring the receiver's electrodernal activity, pupil dilation, peripheral vasodilation, and heart…

  12. Measurements of Direct CP Violating Asymmetries in Charmless Decays of Strange Bottom Mesons and Bottom Baryons

    SciTech Connect

    Aaltonen, T.; Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Apresyan, A.; /Purdue U. /Waseda U. /Dubna, JINR

    2011-03-01

    We report measurements of direct CP-violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb{sup -1} of integrated luminosity, we obtain the first measurements of direct CP violation in bottom strange mesons, A{sub CP}(B{sub s}{sup 0} {yields} K{sup -}{pi}{sup +}) = +0.39 {+-} 0.15 (stat) {+-} 0.08 (syst), and botton baryons, A{sub CP}({Lambda}{sub b}{sup 0} {yields} p{pi}{sup -}) = + 0.03 {+-} 0.17 (stat) {+-} 0.05 (syst) and A{sub CP} ({Lambda}{sub b}{sup 0} {yields} pK{sup -}) = +0.37 {+-} 0.17 (stat) {+-} 0.03 (syst). In addition, they measure CP violation in B{sup 0} {yields} K{sup +}{pi}{sup -} decays with 3.5{sigma} significance, A{sub CP} (B{sup 0} {yields} K{sup +}{pi}{sup -}) = -0.086 {+-} 0.023 (stat) {+-} 0.009 (syst), in agreement with the current world average. Measurements of branching fractions of B{sub s}{sup 0} {yields} K{sup +}K{sup -} and B{sup 0} {yields} {pi}{sup +}{pi}{sup -} decays are also updated.

  13. Measurements of Direct CP Violating Asymmetries in Charmless Decays of Strange Bottom Mesons and Bottom Baryons

    SciTech Connect

    Aaltonen, T.; Brucken, E.; Devoto, F.; Mehtala, P.; Orava, R.; Alvarez Gonzalez, B.; Casal, B.; Cuevas, J.; Gomez, G.; Palencia, E.; Rodrigo, T.; Ruiz, A.; Scodellaro, L.; Vila, I.; Vilar, R.; Vizan, J.; Amerio, S.; Dorigo, T.; Gresele, A.; Lazzizzera, I.

    2011-05-06

    We report measurements of direct CP--violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb{sup -1} of integrated luminosity, we obtain the first measurements of direct CP violation in bottom strange mesons, A{sub CP}(B{sub s}{sup 0}{yields}K{sup -}{pi}{sup +})=+0.39{+-}0.15(stat){+-}0.08(syst), and bottom baryons, A{sub CP}({Lambda}{sub b}{sup 0}{yields}p{pi}{sup -})=+0.03{+-}0.17(stat){+-}0.05(syst) and A{sub CP}({Lambda}{sub b}{sup 0}{yields}pK{sup -})=+0.37{+-}0.17(stat){+-}0.03(syst). In addition, we measure CP violation in B{sup 0}{yields}K{sup +}{pi}{sup -} decays with 3.5{sigma} significance, A{sub CP}(B{sup 0}{yields}K{sup +}{pi}{sup -})=-0.086{+-}0.023(stat){+-}0.009(syst), in agreement with the current world average. Measurements of branching fractions of B{sub s}{sup 0}{yields}K{sup +}K{sup -} and B{sup 0}{yields}{pi}{sup +}{pi}{sup -} decays are also updated.

  14. Measurements of direct CP violating asymmetries in charmless decays of strange bottom mesons and bottom baryons.

    PubMed

    Aaltonen, T; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Apresyan, A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bauer, G; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Bland, K R; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Brisuda, A; Bromberg, C; Brucken, E; Bucciantonio, M; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Calancha, C; Camarda, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Compostella, G; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Dagenhart, D; d'Ascenzo, N; Datta, M; de Barbaro, P; De Cecco, S; De Lorenzo, G; Dell'orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Devoto, F; d'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Dorigo, M; Dorigo, T; Ebina, K; Elagin, A; Eppig, A; Erbacher, R; Errede, D; Errede, S; Ershaidat, N; Eusebi, R; Fang, H C; Farrington, S; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Funakoshi, Y; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, S R; Halkiadakis, E; Hamaguchi, A; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harr, R F; Hatakeyama, K; Hays, C; Heck, M; Heinrich, J; Herndon, M; Hewamanage, S; Hidas, D; Hocker, A; Hopkins, W; Horn, D; Hou, S; Hughes, R E; Hurwitz, M; Husemann, U; Hussain, N; Hussein, M; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirby, M; Klimenko, S; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kuhr, T; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, E; Lee, H S; Lee, J S; Lee, S W; Leo, S; Leone, S; Lewis, J D; Lin, C-J; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, Q; Liu, T; Lockwitz, S; Lockyer, N S; Loginov, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maeshima, K; Makhoul, K; Maksimovic, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Martínez, M; Martínez-Ballarín, R; Mastrandrea, P; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Movilla Fernandez, P; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Potamianos, K; Poukhov, O; Prokoshin, F; Pronko, A; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Rescigno, M; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rubbo, F; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Sakurai, Y; Santi, L; Sartori, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shreyber, I; Simonenko, A; Sinervo, P; Sissakian, A; Sliwa, K; Smith, J R; Snider, F D; Soha, A; Somalwar, S; Sorin, V; Squillacioti, P; Stancari, M; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Sudo, Y; Sukhanov, A; Suslov, I; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thome, J; Thompson, G A; Thomson, E; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Tu, Y; Ukegawa, F; Uozumi, S; Varganov, A; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vila, I; Vilar, R; Vizán, J; Vogel, M; Volpi, G; Wagner, P; Wagner, R L; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Wick, F; Williams, H H; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, H; Wright, T; Wu, X; Wu, Z; Yamamoto, K; Yamaoka, J; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanetti, A; Zeng, Y; Zucchelli, S

    2011-05-06

    We report measurements of direct CP-violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb(-1) of integrated luminosity, we obtain the first measurements of direct CP violation in bottom strange mesons, A(CP)(B(s)(0)→K(-)π(+))=+0.39±0.15(stat)±0.08(syst), and bottom baryons, A(CP)(Λ(b)(0)→pπ(-))=+0.03±0.17(stat)±0.05(syst) and A(CP)(Λ(b)(0)→pK(-))=+0.37±0.17(stat)±0.03(syst). In addition, we measure CP violation in B(0)→K(+)π(-) decays with 3.5σ significance, A(CP)(B(0)→K(+)π(-))=-0.086±0.023(stat)±0.009(syst), in agreement with the current world average. Measurements of branching fractions of B(s)(0)→K(+)K(-) and B(0)→π(+)π(-) decays are also updated.

  15. Direct Measurement Sensor of the Boundary Shear Stress in Fluid Flow

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Bao, Xiaoqi; Bar-Cohen, Yoseph; Chang, Zensheu; Kerenyi, Kornel; Lih, Shyh-Shiuh; Sherrit, Stewart; Trease, Brian P.; Widholm, Scott

    2010-01-01

    The flow fields and boundary erosion that are associated with scour at bridge piers are very complex. Direct measurement of the boundary shear stress and boundary pressure fluctuations in experimental scour research has always been a challenge and high spatial resolution and fidelity have been almost impossible. Most researchers have applied an indirect process to determine shear stress using precise measured velocity profiles. Laser Doppler Anemometry and Particle Image Velocimetry are common techniques used to accurately measure velocity profiles. These methods are based on theoretical assumptions to estimate boundary shear stress. In addition, available turbulence models cannot very well account for the effect of bed roughness which is fundamentally important for any CFD simulation. The authors have taken on the challenge to advance the magnitude level to which direct measurements of the shear stress in water flow can be performed. This paper covered the challenges and the efforts to develop a higher accuracy and small spatial resolution sensor. Also, preliminary sensor designs and test results are presented.

  16. Direct Measurement Sensor of the Boundary Shear Stress in Fluid Flow

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Bao, Xiaoqi; Bar-Cohen, Yoseph; Chang, Zensheu; Kerenyi, Kornel; Lih, Shyh-Shiuh; Sherrit, Stewart; Trease, Brian P.; Widholm, Scott

    2010-01-01

    The flow fields and boundary erosion that are associated with scour at bridge piers are very complex. Direct measurement of the boundary shear stress and boundary pressure fluctuations in experimental scour research has always been a challenge and high spatial resolution and fidelity have been almost impossible. Most researchers have applied an indirect process to determine shear stress using precise measured velocity profiles. Laser Doppler Anemometry and Particle Image Velocimetry are common techniques used to accurately measure velocity profiles. These methods are based on theoretical assumptions to estimate boundary shear stress. In addition, available turbulence models cannot very well account for the effect of bed roughness which is fundamentally important for any CFD simulation. The authors have taken on the challenge to advance the magnitude level to which direct measurements of the shear stress in water flow can be performed. This paper covered the challenges and the efforts to develop a higher accuracy and small spatial resolution sensor. Also, preliminary sensor designs and test results are presented.

  17. Direct measurement of power during one single sprint on treadmill.

    PubMed

    Morin, J B; Samozino, P; Bonnefoy, R; Edouard, P; Belli, A

    2010-07-20

    We tested the validity of an instrumented treadmill dynamometer for measuring maximal propulsive power during sprint running, and sought to verify whether this could be done over one single sprint, as shown during sprint cycling. The treadmill dynamometer modified towards sprint use (constant motor torque) allows vertical and horizontal forces to be measured at the same location as velocity, i.e. at the foot, which is novel compared to existing methods in which power is computed as the product of belt velocity and horizontal force measured by transducers placed in the tethering system. Twelve males performed 6s sprints against default, high and low loads set from the motor torque necessary to overcome the friction due to subjects' weight on the belt (default load), and 20% higher and lower motor torque values. Horizontal ground reaction force, belt velocity, propulsive power and linear force-velocity relationships were compared between the default load condition and when taking all conditions together. Force and velocity traces and values were reproducible and consistent with the literature, and no significant difference was found between maximal power and force-velocity relationships obtained in the default load condition only vs. adding data from all conditions. The presented method allows one to measure maximal propulsive power and calculate linear force-velocity relationships from one single sprint data. The main novelties are that both force and velocity are measured at the same location, and that instantaneous values are averaged over one contact period, and not over a constant arbitrary time-window. 2010 Elsevier Ltd. All rights reserved.

  18. Nitrate removal in stream ecosystems measured by 15N addition experiments: Denitrification

    USGS Publications Warehouse

    Mulholland, P.J.; Hall, R.O.; Sobota, D.J.; Dodds, W.K.; Findlay, S.E.G.; Grimm, N. B.; Hamilton, S.K.; McDowell, W.H.; O'Brien, J. M.; Tank, J.L.; Ashkenas, L.R.; Cooper, L.W.; Dahm, Clifford N.; Gregory, S.V.; Johnson, S.L.; Meyer, J.L.; Peterson, B.J.; Poole, G.C.; Valett, H.M.; Webster, J.R.; Arango, C.P.; Beaulieu, J.J.; Bernot, M.J.; Burgin, A.J.; Crenshaw, C.L.; Helton, A.M.; Johnson, L.T.; Niederlehner, B.R.; Potter, J.D.; Sheibley, R.W.; Thomasn, S.M.

    2009-01-01

    We measured denitrification rates using a field 15N-NO- 3 tracer-addition approach in a large, cross-site study of nitrate uptake in reference, agricultural, and suburban-urban streams. We measured denitrification rates in 49 of 72 streams studied. Uptake length due to denitrification (SWden) ranged from 89 m to 184 km (median of 9050 m) and there were no significant differences among regions or land-use categories, likely because of the wide range of conditions within each region and land use. N2 production rates far exceeded N2O production rates in all streams. The fraction of total NO-3 removal from water due to denitrification ranged from 0.5% to 100% among streams (median of 16%), and was related to NHz 4 concentration and ecosystem respiration rate (ER). Multivariate approaches showed that the most important factors controlling SWden were specific discharge (discharge / width) and NO-3 concentration (positive effects), and ER and transient storage zones (negative effects). The relationship between areal denitrification rate (Uden) and NO- 3 concentration indicated a partial saturation effect. A power function with an exponent of 0.5 described this relationship better than a Michaelis-Menten equation. Although Uden increased with increasing NO- 3 concentration, the efficiency of NO-3 removal from water via denitrification declined, resulting in a smaller proportion of streamwater NO-3 load removed over a given length of stream. Regional differences in stream denitrification rates were small relative to the proximate factors of NO-3 concentration and ecosystem respiration rate, and land use was an important but indirect control on denitrification in streams, primarily via its effect on NO-3 concentration. ?? 2009.

  19. Modeling particulate matter concentrations measured through mobile monitoring in a deletion/substitution/addition approach

    NASA Astrophysics Data System (ADS)

    Su, Jason G.; Hopke, Philip K.; Tian, Yilin; Baldwin, Nichole; Thurston, Sally W.; Evans, Kristin; Rich, David Q.

    2015-12-01

    Land use regression modeling (LUR) through local scale circular modeling domains has been used to predict traffic-related air pollution such as nitrogen oxides (NOX). LUR modeling for fine particulate matters (PM), which generally have smaller spatial gradients than NOX, has been typically applied for studies involving multiple study regions. To increase the spatial coverage for fine PM and key constituent concentrations, we designed a mobile monitoring network in Monroe County, New York to measure pollutant concentrations of black carbon (BC, wavelength at 880 nm), ultraviolet black carbon (UVBC, wavelength at 3700 nm) and Delta-C (the difference between the UVBC and BC concentrations) using the Clarkson University Mobile Air Pollution Monitoring Laboratory (MAPL). A Deletion/Substitution/Addition (D/S/A) algorithm was conducted, which used circular buffers as a basis for statistics. The algorithm maximizes the prediction accuracy for locations without measurements using the V-fold cross-validation technique, and it reduces overfitting compared to other approaches. We found that the D/S/A LUR modeling approach could achieve good results, with prediction powers of 60%, 63%, and 61%, respectively, for BC, UVBC, and Delta-C. The advantage of mobile monitoring is that it can monitor pollutant concentrations at hundreds of spatial points in a region, rather than the typical less than 100 points from a fixed site saturation monitoring network. This research indicates that a mobile saturation sampling network, when combined with proper modeling techniques, can uncover small area variations (e.g., 10 m) in particulate matter concentrations.

  20. Nitrate removal in stream ecosystems measured by 15N addition experiments: 2. Denitrification

    SciTech Connect

    Mulholland, Patrick J; Hall, Robert; Sobota, Daniel; Dodds, Walter; Findlay, Stuart; Grimm, Nancy; Hamilton, Stephen; McDowell, William; O'Brien, Jon; Tank, Jennifer; Ashkenas, Linda; Cooper, Lee W; Dahm, Cliff; Gregory, Stanley; Johnson, Sherri; Meyer, Judy; Peterson, Bruce; Poole, Geoff; Valett, H. Maurice; Webster, Jackson; Arango, Clay; Beaulieu, Jake; Bernot, Melody; Burgin, Amy; Crenshaw, Chelsea; Helton, Ashley; Johnson, Laura; Niederlehner, Bobbie; Potter, Jody; Sheibley, Rich; Thomas, Suzanne

    2009-01-01

    We measured denitrification rates using a field {sup 15}N-NO{sub 3}{sup -} tracer-addition approach in a large, cross-site study of nitrate uptake in reference, agricultural, and suburban-urban streams. We measured denitrification rates in 49 of 72 streams studied. Uptake length due to denitrification (S{sub Wden}) ranged from 89 m to 184 km (median of 9050 m) and there were no significant differences among regions or land-use categories, likely because of the wide range of conditions within each region and land use. N{sub 2} production rates far exceeded N{sub 2}O production rates in all streams. The fraction of total NO{sub 3}{sup -} removal from water due to denitrification ranged from 0.5% to 100% among streams (median of 16%), and was related to NH{sub 4}{sup +} concentration and ecosystem respiration rate (ER). Multivariate approaches showed that the most important factors controlling S{sub Wden} were specific discharge (discharge/width) and NO{sub 3}{sup -} concentration (positive effects), and ER and transient storage zones (negative effects). The relationship between areal denitrification rate (U{sub den}) and NO{sub 3}{sup -} concentration indicated a partial saturation effect. A power function with an exponent of 0.5 described this relationship better than a Michaelis-Menten equation. Although U{sub den} increased with increasing NO{sub 3}{sup -} concentration, the efficiency of NO{sub 3}{sup -} removal from water via denitrification declined, resulting in a smaller proportion of streamwater NO{sub 3}{sup -} load removed over a given length of stream. Regional differences in stream denitrification rates were small relative to the proximate factors of NO{sub 3}{sup -} concentration and ecosystem respiration rate, and land use was an important but indirect control on denitrification in streams, primarily via its effect on NO{sub 3}{sup -} concentration.

  1. Measurement and reversal of the direct oral anticoagulants.

    PubMed

    Samuelson, Bethany T; Cuker, Adam

    2017-01-01

    Direct oral anticoagulants (DOACs) offer noninferior efficacy and improved safety compared to vitamin K antagonists (VKAs) for the prevention and treatment of venous thromboembolism and for the prevention of stroke and systemic embolism in nonvalvular atrial fibrillation. Unlike VKAs, DOACs do not require routine laboratory monitoring of anticoagulant effect and dose adjustment. In certain situations, however, laboratory assessment of anticoagulant effect may be desirable. Here we review the utility of currently available assays for assessment of DOAC effect and recommend an optimal assessment strategy for each drug, including calibrated dilute thrombin time or ecarin-based assays for dabigatran and calibrated anti-Xa activity assays for the factor Xa inhibitors. We also discuss reversal strategies, both specific and nonspecific, for each drug, including the preferential use of idarucizumab for the reversal of dabigatran and two agents, andexanet and ciraparantag, currently under development for the reversal of rivaroxaban, apixaban, and edoxaban. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Quantum signatures of a molecular nanomagnet in direct magnetocaloric measurements.

    PubMed

    Sharples, Joseph W; Collison, David; McInnes, Eric J L; Schnack, Jürgen; Palacios, Elias; Evangelisti, Marco

    2014-10-22

    Geometric spin frustration in low-dimensional materials, such as the two-dimensional kagome or triangular antiferromagnetic nets, can significantly enhance the change of the magnetic entropy and adiabatic temperature following a change in the applied magnetic field, that is, the magnetocaloric effect. In principle, an equivalent outcome should also be observable in certain high-symmetry zero-dimensional, that is, molecular, structures with frustrated topologies. Here we report experimental realization of this in a heptametallic gadolinium molecule. Adiabatic demagnetization experiments reach ~200 mK, the first sub-Kelvin cooling with any molecular nanomagnet, and reveal isentropes (the constant entropy paths followed in the temperature-field plane) with a rich structure. The latter is shown to be a direct manifestation of the trigonal antiferromagnetic net structure, allowing study of frustration-enhanced magnetocaloric effects in a finite system.

  3. Direct measurements of torque during Holliday junction migration.

    PubMed

    Forth, Scott; Deufel, Christopher; Patel, Smita S; Wang, Michelle D

    2011-07-20

    DNA experiences torsional stress resulting from the activities of motor enzymes and bound proteins. The mechanisms by which this torsional stress is dissipated to maintain DNA structural integrity are not fully known. Here, we show that a Holliday junction can limit torsion by coupling rotation to translocation and torque to force. The torque required to mechanically migrate through individual junctions was found to be an order of magnitude smaller than that required to melt DNA. We also directly show that substantially more torque was required to migrate through even a single-base sequence heterology, which has important implications for the activity of junction-migrating enzymes. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  4. Direct measurement of nanoparticle interactions using near-field photonics (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Schein, Perry; O'Dell, Dakota; Erickson, David

    2016-03-01

    Nanoparticle suspensions are used in numerous biomedical applications ranging from sensing and diagnostics to in vivo therapeutic agents and drug delivery mechanisms. One key challenge in developing these technologies is engineering particles that remain stable in the presence of physiological salt concentrations and different pH regimes encountered in applications. Here, we show an approach for high-throughput characterization of nanoparticle stability by directly measuring the interaction energy profiles between nanoparticles and surfaces. As nanoparticles are trapped and propelled along an optical waveguide, they scatter light. Our technique takes advantage of the confined Brownian motion exhibited by the particles as they fluctuate about the equilibrium position between the optical and particle-surface interaction forces. In this way, unlike colloidal probe atomic force microscopy, this technique is capable of making measurements that are not limited by thermal noise, and capable of mapping interaction energy profiles on the sub-kT scale, driven by sub-pN forces. We demonstrate direct measurement of the interactions between protein-coated gold nanoparticles with 50 nm diameters and surfaces in a variety of experimental conditions including changes in specific ions present, overall ionic strength and pH, giving insight into the dynamics of these biologically relevant systems at the nanoscale. These direct measurements on particles with sub-100 nm diameters offer new insights into suspension stability missed by indirect measurements such as absorbance spectroscopy, zeta-potential, and dynamic light scattering, and allow for the detailed study of sub-populations in a heterogeneous sample. Additionally, the sub-pN force resolution makes this a suitable platform for fundamental biophysical studies.

  5. Direct Measurements of Black Holes with the Event Horizon Telescope

    NASA Astrophysics Data System (ADS)

    Fish, Vincent L.; Doeleman, S. S.

    2011-09-01

    The Event Horizon Telescope (EHT) is an array of existing (sub)millimeter telescopes that uses the technique of Very Long Baseline Interferometry (VLBI) to achieve angular resolutions measured in tens of microarcseconds. For the super massive black hole in the Galactic Center (Sgr A*) and in the elliptical galaxy M87, the EHT has detected emission on the scale of the event horizon. In this presentation we describe details of measurements already made with the EHT. We also describe future observations that will allow us to probe orbits of the accretion disk around the black hole in Sgr A* in a manner that is complementary to information obtained from X-ray observations. Emission models of Sgr A* that include the strong gravitational lensing near the black hole indicate that future high-frequency VLBI observations may lead to tests of the "no-hair" theorem, which states that a black hole may be completely characterized by its mass and spin.

  6. Direct measurements of tropospheric ozone from TOMS data. Progress report

    SciTech Connect

    Hudson, R.D.

    1993-01-01

    In the past year, we have made measurements of the tropospheric total column of ozone during the biomass burning season in Africa (August to October). Fishman et. al. had reported previously that by taking a time average of the low spatial resolution data from TOMS (Total Ozone Mapping Spectrometer) on Nimbus-7 (referred to as the Grid-T data set), during the biomass burning season in Africa, a plume of ozone extends from the East coast of Africa into the Atlantic. In this report, we present an analysis that we have made using the measured TOMS radiances taken from the High Density TOMS data set (referred as the HDT data set), which examines this plume in more detail.

  7. Qweak: First Direct Measurement of the Proton's Weak Charge

    NASA Astrophysics Data System (ADS)

    Androic, D.; Armstrong, D. S.; Asaturyan, A.; Averett, T.; Balewski, J.; Bartlett, K.; Beaufait, J.; Beminiwattha, R. S.; Benesch, J.; Benmokhtar, F.; Birchall, J.; Carlini, R. D.; Cates, G. D.; Cornejo, J. C.; Covrig, S.; Dalton, M. M.; Davis, C. A.; Deconinck, W.; Diefenbach, J.; Dowd, J. F.; Dunne, J. A.; Dutta, D.; Duvall, W. S.; Elaasar, M.; Falk, W. R.; Finn, J. M.; Forest, T.; Gal, C.; Gaskell, D.; Gericke, M. T. W.; Grames, J.; Gray, V. M.; Grimm, K.; Guo, F.; Hoskins, J. R.; Johnston, K.; Jones, D.; Jones, M.; Jones, R.; Kargiantoulakis, M.; King, P. M.; Korkmaz, E.; Kowalski, S.; Leacock, J.; Leckey, J.; Lee, A. R.; Lee, J. H.; Lee, L.; MacEwan, S.; Mack, D.; Magee, J. A.; Mahurin, R.; Mammei, J.; Martin, J. W.; McHugh, M. J.; Meekins, D.; Mei, J.; Michaels, R.; Micherdzinska, A.; Mkrtchyan, A.; Mkrtchyan, H.; Morgan, N.; Myers, K. E.; Narayan, A.; Ndukum, L. Z.; Nelyubin, V.; Nuhait, H.; Nuruzzaman; van Oers, W. T. H.; Opper, A. K.; Page, S. A.; Pan, J.; Paschke, K. D.; Phillips, S. K.; Pitt, M. L.; Poelker, M.; Rajotte, J. F.; Ramsay, W. D.; Roche, J.; Sawatzky, B.; Seva, T.; Shabestari, M. H.; Silwal, R.; Simicevic, N.; Smith, G. R.; Solvignon, P.; Spayde, D. T.; Subedi, A.; Subedi, R.; Suleiman, R.; Tadevosyan, V.; Tobias, W. A.; Tvaskis, V.; Waidyawansa, B.; Wang, P.; Wells, S. P.; Wood, S. A.; Yang, S.; Young, R. D.; Zang, P.; Zhamkochyan, S.

    2017-03-01

    The Qweak experiment, which took data at Jefferson Lab in the period 2010 - 2012, will precisely determine the weak charge of the proton by measuring the parity-violating asymmetry in elastic e-p scattering at 1.1 GeV using a longitudinally polarized electron beam and a liquid hydrogen target at a low momentum transfer of Q2 = 0.025 (GeV/c)2. The weak charge of the proton is predicted by the Standard Model and any significant deviation would indicate physics beyond the Standard Model. The technical challenges and experimental apparatus for measuring the weak charge of the proton will be discussed, as well as the method of extracting the weak charge of the proton. The results from a small subset of the data, that has been published, will also be presented. Furthermore an update will be given of the current status of the data analysis.

  8. Direct photon measurements by the D{O} experiment

    SciTech Connect

    Abachi, S.

    1996-07-01

    We report a measurement of the cross section for production of isolated photons with transverse energy E{sub T} > 12 GeV in the central (absolute value of {eta} < 0.9) and forward (1.6 < absolute value of {eta} < 2.5) rapidity regions for {bar p}p collisions at center of mass energy {radical}s = 1.8 TeV, using an integrated luminosity of 13 pb{sup {minus}1}. The cross section is compared with a next-to-leading order (NLO) QCD calculation. We also present preliminary measurements of the center of mass scattering angle distribution and of the correlations between the rapidity of the photon and that of the leading jet in the event.

  9. Direct measurement of the flow field around swimming microorganisms

    NASA Astrophysics Data System (ADS)

    Polin, Marco; Drescher, Knut; Goldstein, Raymond E.; Michel, Nicolas; Tuval, Idan

    2010-11-01

    Swimming microorganisms create flows that influence their mutual interactions and modify the rheology of their suspensions. While extensively studied theoretically, these flows have not been measured in detail around any freely-swimming microorganism. We report such measurements for the microphytes Volvox carteri and Chlamydomonas reinhardtii. The minute (˜0.3%) density excess of V. carteri over water leads to a strongly dominant Stokeslet contribution, with the widely-assumed stresslet flow only a correction to the subleading source dipole term. This implies that suspensions of V. carteri have features similar to suspensions of sedimenting particles. The flow in the region around C. reinhardtii where significant hydrodynamic interaction is likely to occur differs qualitatively from a "puller" stresslet, and can be described by a simple three-Stokeslet model.

  10. Direct Measurement of the Flow Field around Swimming Microorganisms

    NASA Astrophysics Data System (ADS)

    Drescher, Knut; Goldstein, Raymond E.; Michel, Nicolas; Polin, Marco; Tuval, Idan

    2010-10-01

    Swimming microorganisms create flows that influence their mutual interactions and modify the rheology of their suspensions. While extensively studied theoretically, these flows have not been measured in detail around any freely-swimming microorganism. We report such measurements for the microphytes Volvox carteri and Chlamydomonas reinhardtii. The minute (˜0.3%) density excess of V. carteri over water leads to a strongly dominant Stokeslet contribution, with the widely-assumed stresslet flow only a correction to the subleading source dipole term. This implies that suspensions of V. carteri have features similar to suspensions of sedimenting particles. The flow in the region around C. reinhardtii where significant hydrodynamic interaction is likely to occur differs qualitatively from a puller stresslet, and can be described by a simple three-Stokeslet model.

  11. Direct measurement of the Zak phase in topological Bloch bands

    NASA Astrophysics Data System (ADS)

    Atala, Marcos; Aidelsburger, Monika; Barreiro, Julio T.; Abanin, Dmitry; Kitagawa, Takuya; Demler, Eugene; Bloch, Immanuel

    2013-12-01

    Geometric phases that characterize the topological properties of Bloch bands play a fundamental role in the band theory of solids. Here we report on the measurement of the geometric phase acquired by cold atoms moving in one-dimensional optical lattices. Using a combination of Bloch oscillations and Ramsey interferometry, we extract the Zak phase--the Berry phase gained during the adiabatic motion of a particle across the Brillouin zone--which can be viewed as an invariant characterizing the topological properties of the band. For a dimerized lattice, which models polyacetylene, we measure a difference of the Zak phase δφZak=0.97(2)π for the two possible polyacetylene phases with different dimerization. The two dimerized phases therefore belong to different topological classes, such that for a filled band, domain walls have fractional quantum numbers. Our work establishes a new general approach for probing the topological structure of Bloch bands inoptical lattices.

  12. Mental self-government: development of the additional democratic learning style scale using Rasch measurement models.

    PubMed

    Nielsen, Tine; Kreiner, Svend; Styles, Irene

    2007-01-01

    This paper describes the development and validation of a democratic learning style scale intended to fill a gap in Sternberg's theory of mental self-government and the associated learning style inventory (Sternberg, 1988, 1997). The scale was constructed as an 8-item scale with a 7-category response scale. The scale was developed following an adapted version of DeVellis' (2003) guidelines for scale development. The validity of the Democratic Learning Style Scale was assessed by items analysis using graphical loglinear Rasch models (Kreiner and Christensen, 2002, 2004, 2006) The item analysis confirmed that the full 8-item revised Democratic Learning Style Scale fitted a graphical loglinear Rasch model with no differential item functioning but weak to moderate uniform local dependence between two items. In addition, a reduced 6-item version of the scale fitted the pure Rasch model with a rating scale parameterization. The revised Democratic Learning Style Scale can therefore be regarded as a sound measurement scale meeting requirements of both construct validity and objectivity.

  13. Direct Optical Measurement of Vorticity in Fluid Flow

    DTIC Science & Technology

    2015-12-11

    Rotational Doppler Effect (RDE) and Laguerre-Gaussian (LG) light beams that possess orbital angular momentum (OAM). The approach has been implemented...Measuring with RDE requires the use of Laguerre-Gaussian (LG) light beams that possess orbital angular momentum (OAM) l , a spatial (azimuthal...light possesses an orbital angular momentum with a combination of topological charges ±18 and its far-field intensity profile corresponds to a circular

  14. Direct approach to Gaussian measurement based quantum computation

    NASA Astrophysics Data System (ADS)

    Ferrini, G.; Roslund, J.; Arzani, F.; Fabre, C.; Treps, N.

    2016-12-01

    In this work we introduce an original scheme for measurement based quantum computation in continuous variables. Our approach does not necessarily rely on the use of ancillary cluster states to achieve its aim, but rather on the detection of a resource state in a suitable mode basis followed by digital postprocessing, and involves an optimization of the adjustable experimental parameters. After introducing the general method, we present some examples of application to simple specific computations.

  15. Direct measurement of vertical binding energy of a hydrated electron.

    PubMed

    Tang, Ying; Shen, Huan; Sekiguchi, Kentaro; Kurahashi, Naoya; Mizuno, Tomoya; Suzuki, Yoshi-ichi; Suzuki, Toshinori

    2010-04-21

    We present the first measurement of the vertical binding energy (VBE) of a hydrated electron in bulk water by the time-resolved photoelectron spectroscopy (TRPES) of the charge-transfer-to-solvent (CTTS) reaction in aqueous NaI solution. Our best estimate of VBE is 3.27 +/- 0.10 eV for H(2)O and 3.20 +/- 0.10 eV for D(2)O.

  16. Direct measurement of chlorine penetration into biofilms during disinfection.

    PubMed Central

    De Beer, D; Srinivasan, R; Stewart, P S

    1994-01-01

    Transient chlorine concentration profiles were measured in biofilms during disinfection by use of a microelectrode developed for this investigation. The electrode had a tip diameter of ca. 10 microm and was sensitive to chlorine in the micromolar range. The biofilms contained Pseudomonas aeruginosa and Klebsiella pneumoniae. Chlorine concentrations measured in biofilms were typically only 20% or less of the concentration in the bulk liquid. Complete equilibration with the bulk liquid did not occur during the incubation time of 1 to 2 h. The penetration depth of chlorine into the biofilm and rate of penetration varied depending on the measurement location, reflecting heterogeneity in the distribution of biomass and in local hydrodynamics. The shape of the chlorine profiles, the long equilibration times, and the dependence on the bulk chlorine concentration showed that the penetration was a function of simultaneous reaction and diffusion of chlorine in the biofilm matrix. Frozen cross sections of biofilms, stained with a redox dye and a DNA stain, showed that the area of chlorine penetration overlapped with nonrespiring zones near the biofilm-bulk fluid interface. These data indicate that the limited penetration of chlorine into the biofilm matrix is likely to be an important factor influencing the reduced efficacy of this biocide against biofilms as compared with its action against planktonic cells. PMID:7811074

  17. Directed Forgetting in Direct and Indirect Tests of Memory: Seeking Evidence of Retrieval Inhibition Using Electrophysiological Measures

    ERIC Educational Resources Information Center

    Van Hooff, Johanna C.; Whitaker, T. Aisling; Ford, Ruth M.

    2009-01-01

    We investigated whether directed forgetting as elicited by the item-cueing method results solely from "differential rehearsal" of to-be-remembered vs. to-be-forgotten words or, additionally, from "inhibitory" processes that actively impair retrieval of to-be-forgotten words. During study, participants (N = 24) were instructed to remember half of a…

  18. Directed Forgetting in Direct and Indirect Tests of Memory: Seeking Evidence of Retrieval Inhibition Using Electrophysiological Measures

    ERIC Educational Resources Information Center

    Van Hooff, Johanna C.; Whitaker, T. Aisling; Ford, Ruth M.

    2009-01-01

    We investigated whether directed forgetting as elicited by the item-cueing method results solely from "differential rehearsal" of to-be-remembered vs. to-be-forgotten words or, additionally, from "inhibitory" processes that actively impair retrieval of to-be-forgotten words. During study, participants (N = 24) were instructed to remember half of a…

  19. Ocular accommodation and cognitive demand: An additional indicator besides pupil size and cardiovascular measures?

    PubMed Central

    Jainta, Stephanie; Hoormann, Joerg; Jaschinski, Wolfgang

    2008-01-01

    Background The aim of the present study was to assess accommodation as a possible indicator of changes in the autonomic balance caused by altered cognitive demand. Accounting for accommodative responses from a human factors perspective may be motivated by the interest of designing virtual image displays or by establishing an autonomic indicator that allows for remote measurement at the human eye. Heart period, pulse transit time, and the pupillary response were considered as reference for possible closed-loop accommodative effects. Cognitive demand was varied by presenting monocularly numbers at a viewing distance of 5 D (20 cm) which had to be read, added or multiplied; further, letters were presented in a "n-back" task. Results Cardiovascular parameters and pupil size indicated a change in autonomic balance, while error rates and reaction time confirmed the increased cognitive demand during task processing. An observed decrease in accommodation could not be attributed to the cognitive demand itself for two reasons: (1) the cognitive demand induced a shift in gaze direction which, for methodological reasons, accounted for a substantial part of the observed accommodative changes. (2) Remaining effects disappeared when the correctness of task processing was taken into account. Conclusion Although the expectation of accommodation as possible autonomic indicator of cognitive demand was not confirmed, the present results are informative for the field of applied psychophysiology noting that it seems not to be worthwhile to include closed-loop accommodation in future studies. From a human factors perspective, expected changes of accommodation due to cognitive demand are of minor importance for design specifications – of, for example, complex visual displays. PMID:18721478

  20. Measurements of the Effect of Adiabat on Shell Decompression in Direct-Drive Implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Michel, D. T.; Hu, S. X.; Radha, P. B.; Davis, A. K.; Craxton, R. S.; Glebov, V. Yu.; Goncharov, V. N.; Igumenshchev, I. V.; Stoeckl, C.; Froula, D. H.

    2016-10-01

    Measurements of the effect of adiabat (α) on the shell thickness were performed in direct-drive implosions. The maximum in-flight shell thickness was obtained using a novel technique where the outer and inner surfaces of the shell were simultaneously measured using self-emission images of the imploding target. When reducing the shell's adiabat from α = 6 to α = 4.5 , the shell thickness was measured to decrease from 75 μm to 60 μm, but when decreasing the adiabat further (α = 1.8), the shell thickness was measured to increase to 75 μm. The measured shell thickness, shell trajectories, neutron bang time, and neutron yield were reproduced by two-dimensional simulations that include laser imprint, nonlocal thermal transport, cross-beam energy transfer, and first-principles equation-of-state models. These results show that the decompression of the shell measured for low-adiabat implosions was a result of laser imprint. Additional information on the evolution of the density profile was obtained using x-ray radiography. The backlighter was created with six of the 60 OMEGA laser beams, with the pointings and energies of other beams adjusted to maintain a uniform implosion. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  1. Direct measurements of residual absorption in fluoridic thin films and optical materials for DUV laser applications

    NASA Astrophysics Data System (ADS)

    Mühlig, Ch.; Triebel, W.; Kufert, S.; Noppeney, Ch.; Bernitzki, H.

    2007-01-01

    The absorption of ArF laser pulses in calcium fluoride, fused silica as well as in highly (HR) and partially (PR) reflecting fluoridic coatings is directly measured using the laser induced deflection technique (LID). For the calcium fluoride sample it is proved that the LID technique allows to separate surface and bulk absorption by measuring only one sample with the size 20 x 20 x 10 mm 3. At a laser pulse fluence Φ = 36 mJ/cm2 and a repetition rate f = 1 kHz the bulk absorption coefficient and the surface absorption are determined to 0.0029 cm -1 and 0.00043 (two surfaces), respectively. For the HR and PR coatings the ArF laser absorption is 0.0004 for Φ= 22 mJ/cm2 (f = 1 kHz) and 0.0066 for Φ= 40 mJ/cm2 (f = 1 kHz), respectively. For the example of the PR coating the influence of high coating scattering on the LID measurements is discussed and an appropriate measuring procedure is derived and applied to avoid the scattering influence. In addition to the established LID setup requiring rectangular substrate dimensions a modified setup is introduced enabling the measurement of cylindrical optical elements. The principle of the new LID setup is explained and first measurements at fused silica are presented.

  2. Field Measurements of Gasoline Direct Injection Emission Factors: Spatial and Seasonal Variability.

    PubMed

    Zimmerman, Naomi; Wang, Jonathan M; Jeong, Cheol-Heon; Ramos, Manuel; Hilker, Nathan; Healy, Robert M; Sabaliauskas, Kelly; Wallace, James S; Evans, Greg J

    2016-02-16

    Four field campaigns were conducted between February 2014 and January 2015 to measure emissions from light-duty gasoline direct injection (GDI) vehicles (2013 Ford Focus) in an urban near-road environment in Toronto, Canada. Measurements of CO2, CO, NOx, black carbon (BC), benzene, toluene, ethylbenzene-xylenes (BTEX), and size-resolved particle number (PN) were recorded 15 m from the roadway and converted to fuel-based emission factors (EFs). Other than for NOx and CO, the GDI engine had elevated emissions compared to the Toronto fleet, with BC EFs in the 73rd percentile, BTEX EFs in the 80-90th percentile, and PN EFs in the 75th percentile during wintertime measurements. Additionally, for three campaigns, a second platform for measuring PN and CO2 was placed 1.5-3 m from the roadway to quantify changes in PN with distance from point of emission. GDI vehicle PN EFs were found to increase by up to 240% with increasing distance from the roadway, predominantly due to an increasing fraction of sub-40 nm particles. PN and BC EFs from the same engine technology were also measured in the laboratory. BC EFs agreed within 20% between the laboratory and real-world measurements; however, laboratory PN EFs were an order of magnitude lower due to exhaust conditioning.

  3. Stratospheric thickness determined directly from satellite radiance measurements.

    NASA Technical Reports Server (NTRS)

    Quiroz, R. S.; Gelman, M. E.

    1972-01-01

    Discussion of the use of satellite radiance data for determining the thickness of deep stratospheric layers. Empirical regression equations are shown to provide better estimates of stratospheric thickness than do mean weighted temperatures obtained from the Planck equation. The best regression equations were found for thick layers emitting a substantial portion of the CO2-band infrared radiation measured by satellites. By adding the layer thickness to the observed height field for the lower boundary, it is possible to construct constant-pressure maps at very high altitudes.

  4. Stratospheric thickness determined directly from satellite radiance measurements.

    NASA Technical Reports Server (NTRS)

    Quiroz, R. S.; Gelman, M. E.

    1972-01-01

    Discussion of the use of satellite radiance data for determining the thickness of deep stratospheric layers. Empirical regression equations are shown to provide better estimates of stratospheric thickness than do mean weighted temperatures obtained from the Planck equation. The best regression equations were found for thick layers emitting a substantial portion of the CO2-band infrared radiation measured by satellites. By adding the layer thickness to the observed height field for the lower boundary, it is possible to construct constant-pressure maps at very high altitudes.

  5. Direct Measurements of the Baroclinic Instability in the Ocean

    NASA Astrophysics Data System (ADS)

    Sadek, Mahmoud; Aluie, Hussein; Hecht, Matthew; Vallis, Geoffrey

    2016-11-01

    The ocean is mechanically driven by wind and buoyancy at the surface which produce sloping isopycnals with a reservoir of available potential energy (APE). Large scale APE can be converted to kinetic energy via the baroclinic instability, which produces mesoscale eddies. Mesoscale eddies are ubiquitous in mid- and high-latitudes, and play a primary role in determining the strength and trajectories of currents and in generating intrinsic climate variability. The widespread belief that mesoscale eddies are generated through baroclinic instability is based on general accord between observations and linear stability analysis and the predicted behavior of nonlinear models. However, these models are unable to give us quantitative evidence of the extent to which the instability is responsible for eddy generation at various locations in the ocean. To this end, we implement a new coarse-graining framework, recently developed to study flow on a sphere, to directly analyze the baroclinic instability as a function of scale and geographic location, and implement it using strongly eddying high-resolution simulations in the North Atlantic and in the Southern Ocean. The results give us new information about location and intensity of the instability in both physical and spectral space. Partial support was provided by National Science Foundation (NSF) Grant OCE-1259794, US Department of Energy (US DOE) Grant DE-SC0014318, and the LANL LDRD program through Project Number 20150568ER.

  6. Application of Direct Current Potential Drop for Fracture Toughness Measurement

    SciTech Connect

    Chen, Xiang; Nanstad, Randy K; Sokolov, Mikhail A

    2013-01-01

    Material fracture toughness based on J-integral versus crack-extension relationship (J-R curve) is investigated with direct current potential drop (DCPD) technique and compared with results from elastic unloading compliance (EUC) or normalization technique. The test matrix covered four different materials, half inch thickness and one inch thickness compact tension (C(T))specimens, and temperatures ranging from 24 C to 600 C. The original J-R curves from DCPD yielded much smaller Jq value than EUC or normalization results due to the influence of plastic deformation on potential drop. To counter this effect, two new methods for adjusting DCPD data have been proposed. After adjustment, the average difference in Jq between DCPD and EUC or normalization results is only about 8% whereas the difference in tearing modulus is about 17%. The promising results prove the applicability of DCPD for J-R curve determination for C(T) specimens especially in extreme environments, such as elevated temperatures, where conventional EUC method faces considerable challenges.

  7. Direct Measurement of Impurity Transport in a Field Reversed Configuration

    NASA Astrophysics Data System (ADS)

    Roche, T.; Bolte, N.; Heidbrink, W. W.; McWilliams, R.; Wessel, F.

    2011-10-01

    An optical tomography system has been developed and implemented in the Flux Coil Generated Field Reversed Configuration (FCG-FRC) at Tri Alpha Energy. Sixteen chords view ~ 35 % of the FRC at the mid-plane. The chords are arranged in two identical fans of eight chords each. To measure transport of an impurity species, argon, an FRC is generated using either Nitrogen or Deuterium as the primary species. A puff valve is activated prior to the shot such that the argon begins to bleed in to the vacuum chamber as the FRC is formed. The gas is puffed at the optimal location for tomographic reconstruction. Each chord is collimated to illuminate a fiber optic cable which is fed to an array of photomultiplier tubes which are fitted with neutral density and band pass filters to allow the appropriate amount of light from the emitting, singly ionized, argon at 434 . 8 nm to be measured. Using a preliminary assumption that density of argon is proportional to light intensity gathered data have been used to reconstruct density profiles. These profiles often peak near the field null. The data are being analyzed to determine diffusive and convective transport coefficients.

  8. Direct lifetime measurements of the excited states in Ni72

    DOE PAGES

    Kolos, K.; Miller, D.; Grzywacz, R.; ...

    2016-03-22

    The lifetimes of the first excited 2+ and 4+ states in 72Ni were measured at the National Superconducting Cyclotron Laboratory with the recoil-distance Doppler-shift method, a model-independent probe to obtain the reduced transition probability. Excited states in 72Ni were populated by the one-proton knockout reaction of an intermediate energy 73Cu beam. γ-ray-recoil coincidences were detected with the γ-ray tracking array GRETINA and the S800 spectrograph. Our results provide evidence of enhanced transition probability B(E2;2+ → 0+) as compared to 68Ni, but do not confirm the trend of large B(E2) values reported in the neighboring isotope 70Ni obtained from Coulomb excitationmore » measurement. The results are compared to shell model calculations. Here, the lifetime obtained for the excited 4+1 state is consistent with models showing decay of a seniority ν = 4, 4+ state, which is consistent with the disappearance of the 8+ isomer in 72Ni.« less

  9. Study of EMIC wave excitation using direct ion measurements

    NASA Astrophysics Data System (ADS)

    Min, Kyungguk; Liu, Kaijun; Bonnell, John W.; Breneman, Aaron W.; Denton, Richard E.; Funsten, Herbert O.; Jahn, Jöerg-Micha; Kletzing, Craig A.; Kurth, William S.; Larsen, Brian A.; Reeves, Geoffrey D.; Spence, Harlan E.; Wygant, John R.

    2015-04-01

    With data from Van Allen Probes, we investigate electromagnetic ion cyclotron (EMIC) wave excitation using simultaneously observed ion distributions. Strong He band waves occurred while the spacecraft was moving through an enhanced density region. We extract from helium, oxygen, proton, and electron mass spectrometer measurement the velocity distributions of warm heavy ions as well as anisotropic energetic protons that drive wave growth through the ion cyclotron instability. Fitting the measured ion fluxes to multiple sinm-type distribution functions, we find that the observed ions make up about 15% of the total ions, but about 85% of them are still missing. By making legitimate estimates of the unseen cold (below ˜2 eV) ion composition from cutoff frequencies suggested by the observed wave spectrum, a series of linear instability analyses and hybrid simulations are carried out. The simulated waves generally vary as predicted by linear theory. They are more sensitive to the cold O+ concentration than the cold He+ concentration. Increasing the cold O+ concentration weakens the He band waves but enhances the O band waves. Finally, the exact cold ion composition is suggested to be in a range when the simulated wave spectrum best matches the observed one.

  10. Direct Lifetime Measurements of the Excited States in 72Ni

    NASA Astrophysics Data System (ADS)

    Kolos, K.; Miller, D.; Grzywacz, R.; Iwasaki, H.; Al-Shudifat, M.; Bazin, D.; Bingham, C. R.; Braunroth, T.; Cerizza, G.; Gade, A.; Lemasson, A.; Liddick, S. N.; Madurga, M.; Morse, C.; Portillo, M.; Rajabali, M. M.; Recchia, F.; Riedinger, L. L.; Voss, P.; Walters, W. B.; Weisshaar, D.; Whitmore, K.; Wimmer, K.; Tostevin, J. A.

    2016-03-01

    The lifetimes of the first excited 2+ and 4+ states in 72>Ni were measured at the National Superconducting Cyclotron Laboratory with the recoil-distance Doppler-shift method, a model-independent probe to obtain the reduced transition probability. Excited states in 72Ni were populated by the one-proton knockout reaction of an intermediate energy 73Cu beam. γ -ray-recoil coincidences were detected with the γ -ray tracking array GRETINA and the S800 spectrograph. Our results provide evidence of enhanced transition probability B (E 2 ;2+→0+) as compared to 68Ni, but do not confirm the trend of large B (E 2 ) values reported in the neighboring isotope 70Ni obtained from Coulomb excitation measurement. The results are compared to shell model calculations. The lifetime obtained for the excited 41+ state is consistent with models showing decay of a seniority ν =4 , 4+ state, which is consistent with the disappearance of the 8+ isomer in 72Ni.

  11. Direct Measurement of Helical Cell Motion of the Spirochete Leptospira

    PubMed Central

    Nakamura, Shuichi; Leshansky, Alexander; Magariyama, Yukio; Namba, Keiichi; Kudo, Seishi

    2014-01-01

    Leptospira are spirochete bacteria distinguished by a short-pitch coiled body and intracellular flagella. Leptospira cells swim in liquid with an asymmetric morphology of the cell body; the anterior end has a long-pitch spiral shape (S-end) and the posterior end is hook-shaped (H-end). Although the S-end and the coiled cell body called the protoplasmic cylinder are thought to be responsible for propulsion together, most observations on the motion mechanism have remained qualitative. In this study, we analyzed the swimming speed and rotation rate of the S-end, protoplasmic cylinder, and H-end of individual Leptospira cells by one-sided dark-field microscopy. At various viscosities of media containing different concentrations of Ficoll, the rotation rate of the S-end and protoplasmic cylinder showed a clear correlation with the swimming speed, suggesting that these two helical parts play a central role in the motion of Leptospira. In contrast, the H-end rotation rate was unstable and showed much less correlation with the swimming speed. Forces produced by the rotation of the S-end and protoplasmic cylinder showed that these two helical parts contribute to propulsion at nearly equal magnitude. Torque generated by each part, also obtained from experimental motion parameters, indicated that the flagellar motor can generate torque >4000 pN nm, twice as large as that of Escherichia coli. Furthermore, the S-end torque was found to show a markedly larger fluctuation than the protoplasmic cylinder torque, suggesting that the unstable H-end rotation might be mechanically related to changes in the S-end rotation rate for torque balance of the entire cell. Variations in torque at the anterior and posterior ends of the Leptospira cell body could be transmitted from one end to the other through the cell body to coordinate the morphological transformations of the two ends for a rapid change in the swimming direction. PMID:24411236

  12. A Single-Lumen Central Venous Catheter for Continuous and Direct Intra-abdominal Pressure Measurement.

    PubMed

    van Waes, Oscar J F; Jaquet, Jean B; Hop, Wim C J; Morak, Marjolein J M; Ijzermans, Jan M; Koning, Jan

    2009-12-01

    Abdominal compartment syndrome (ACS) is associated with high morbidity and mortality rates. Therefore, the need for a good diagnostic tool to predict intra-abdominal hypertension (IAH) and progression to ACS is paramount. Bladder pressure (BP) has been used for several years for intra-abdominal pressure (IAP) measurement but has the disadvantage that it is not a continuous measurement. In this study, a single-lumen central venous catheter (CVC) is placed through the abdominal wall into the abdominal cavity to continuously and directly monitor the intraabdominal pressure (CDIAP). The aim of this study was to evaluate the use of CDIAP to measure BP as a representative of the true IAP. Both BP and CDIAP were prospectively recorded on a variety of surgical patients admitted to the intensive care unit (ICU) from March 2003 up to December 2004. At the end of the surgical procedure, the CVC was placed through the abdominal wall and connected to a pressure transducer. In addition, the BP was measured through the urine drainage port after clamping the catheter and filling the bladder with 50 ml of 0.9% saline. At least three paired measurements (BP and CDIAP) were performed for at least one day on the ICU in a standardized manner at preset time intervals on each patient. The paired measurements were compared using the Bland-Altman (B-A) method. Data are presented as mean ± standard deviation. Over a period of 22 months (March 2003 until December 2004), 125 paired measurements of both BP and CDIAP were recorded on 25 patients. The mean age was 72.4 ± 6.6 years. Eighteen patients underwent central vascular surgery, and seven patients with peritonitis received laparotomy. The mean CDIAP was 11.4 ± 4.8 (range 2-30) mmHg, and the BP was 12.9 ± 5.3 (range 3-37) mmHg. The mean difference between CDIAP and BP was 1.6 ± 2.7 mmHg. There was an acceptable level of agreement (intraclass correlation 0.82) between IAP measured by BP and IAP measured via CDIAP. Continuous direct

  13. Direct Measurements of Reconnection Rate Attenuation by Plasmasphere Plumes

    NASA Astrophysics Data System (ADS)

    Sanchez, E. R.; Takahashi, K.

    2013-12-01

    It is widely hypothesized that mass loading of the magnetosphere (the process whereby the average mass density of the magnetosphere increases from its nominal value) significantly impacts solar wind-magnetosphere coupling and circulation within the magnetosphere. One important way in which mass loading can affect the magnetosphere occurs when enhanced convection after a lull in geomagnetic activity brings super-dense plasma from the plasmasphere (the so-called plasmsphere plume) into the dayside reconnection site. We measured the magnetic flux across the dayside polar cap boundary (a proxy of the dayside magnetic field reconnection rate) and tracked the sunward migration of the plasma plume for three storms that occurred after long intervals of quiet conditions. Significant intermittent reduction in the dayside reconnection potential (approximately 66% in the most pronounced case) was observed in the hours following the onset of negative IMF Bz condition, in agreement with the hypothesis that super-dense magnetospheric plasma convected into the dayside magnetopause inhibits reconnection.

  14. Direct Measurement of Wave Kernels in Time-Distance Helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, T. L., Jr.

    2006-01-01

    Solar f-mode waves are surface-gravity waves which propagate horizontally in a thin layer near the photosphere with a dispersion relation approximately that of deep water waves. At the power maximum near 3 mHz, the wavelength of 5 Mm is large enough for various wave scattering properties to be observable. Gizon and Birch (2002,ApJ,571,966)h ave calculated kernels, in the Born approximation, for the sensitivity of wave travel times to local changes in damping rate and source strength. In this work, using isolated small magnetic features as approximate point-sourc'e scatterers, such a kernel has been measured. The observed kernel contains similar features to a theoretical damping kernel but not for a source kernel. A full understanding of the effect of small magnetic features on the waves will require more detailed modeling.

  15. Direct Measurement of Wave Kernels in Time-Distance Helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, T. L., Jr.

    2006-01-01

    Solar f-mode waves are surface-gravity waves which propagate horizontally in a thin layer near the photosphere with a dispersion relation approximately that of deep water waves. At the power maximum near 3 mHz, the wavelength of 5 Mm is large enough for various wave scattering properties to be observable. Gizon and Birch (2002,ApJ,571,966)h ave calculated kernels, in the Born approximation, for the sensitivity of wave travel times to local changes in damping rate and source strength. In this work, using isolated small magnetic features as approximate point-sourc'e scatterers, such a kernel has been measured. The observed kernel contains similar features to a theoretical damping kernel but not for a source kernel. A full understanding of the effect of small magnetic features on the waves will require more detailed modeling.

  16. Effect of silica fume addition on the PGNAA measurement of chlorine in concrete.

    PubMed

    Naqvi, A A; Maslehuddin, M; Garwan, M A; Nagadi, M M; Al-Amoudi, O S B; Raashid, M; Khateeb-ur-Rehman

    2010-03-01

    Pozzolanic materials, such as fly ash (FA), silica fume (SF), and blast furnace slag (BFS) are added to Portland cement in concrete to prevent reinforcement steel corrosion in concrete. Further preventive measure against reinforcement steel corrosion require monitoring of chloride salts concentration in concrete using non-destructive techniques, such as the prompt gamma-ray neutron activation analysis (PGNAA) technique. Due to interferences between gamma-rays from chlorine and calcium in PGNAA technique, detection limit of chlorine in concrete strongly depends upon calcium concentration in concrete. SF mainly contains silica and its addition to cement concrete reduces overall concentration of calcium in concrete. This may result in an improvement in detection limit of chlorine in SF-based concrete in PGNAA studies. Particularly for chlorine detection using 6.11 and 6.62 MeV prompt gamma-rays that strongly interfere with 6.42 MeV prompt gamma-rays from calcium. In this study, SF was added to Portland cement to prevent concrete reinforcement steel from corrosion. The chlorine concentration in SF cement concrete specimens containing 0.2-3.0 wt% chlorine was measured through yield of 1.16, 1.95, 6.11, 6.62, 7.41, 7.79, and 8.58 MeV chlorine gamma-rays using PGNAA technique. An excellent agreement was noted between the experimental yield of the prompt gamma-rays and the gamma-ray yield calculated through the Monte Carlo simulations. Further the minimum detectable concentration (MDC) of chlorine in SF cement concrete was calculated and compared with the MDC values of chlorine in plain concrete and concrete mixed with fly ash cement. The MDC of chlorine in SF-based concrete through 6.11 MeV, and 6.62 MeV chlorine gamma-rays was found to be improved as compared to those in plain concrete and concrete mixed with fly ash cement. Copyright 2009 Elsevier Ltd. All rights reserved.

  17. Direct and Indirect Measures of Level-2 Perspective-Taking in Children and Adults

    ERIC Educational Resources Information Center

    Surtees, Andrew D. R.; Butterfill, Stephen A.; Apperly, Ian A.

    2012-01-01

    Studies with infants show divergence between performance on theory of mind tasks depending on whether "direct" or "indirect" measures are used. It has been suggested that direct measures assess a flexible but cognitively demanding ability to reason about the minds of others, whereas indirect measures assess distinct processes…

  18. Direct, Dynamic Measurement of Interfacial Area within Porous Media

    SciTech Connect

    Crandall, Dustin; Ahmadi, Goodarz; Smith, Duane H.; Bromhal, Grant

    2010-01-01

    Standard models of two-phase flow in porous media have been shown to exhibit several shortcomings that might be partially overcome with a recently developed model based on thermodynamic principles (Hassanizadeh and Gray, 1990). This alternative two-phase flow model contains a set of new and non-standard parameters, including specific interfacial area. By incorporating interfacial area production, destruction, and propagation into functional relationships that describe the capillary pressure and saturation, a more physical model has been developed. Niessner and Hassanizadeh (2008) have examined this model numerically and have shown that the model captures saturation hysteresis with drainage/imbibition cycles. Several static experimental studies have been performed to examine the validity of this new thermodynamically based approach; these allow the determination of static parameters of the model. To date, no experimental studies have obtained information about the dynamic parameters required for the model. A new experimental porous flow cell has been constructed using stereolithography to study two-phase flow phenomena (Crandall et al. 2008). A novel image analysis tool was developed for an examination of the evolution of flow patterns during displacement experiments (Crandall et al. 2009). This analysis tool enables the direct quantification of interfacial area between fluids by matching known geometrical properties of the constructed flow cell with locations identified as interfaces from images of flowing fluids. Numerous images were obtained from two-phase experiments within the flow cell. The dynamic evolution of the fluid distribution and the fluid-fluid interface locations were determined by analyzing these images. In this paper, we give a brief introduction to the thermodynamically based two-phase flow model, review the properties of the stereolithography flow cell, and show how the image analysis procedure has been used to obtain dynamic parameters for the

  19. Laser Doppler imaging of genital blood flow: a direct measure of female sexual arousal.

    PubMed

    Waxman, Samantha E; Pukall, Caroline F

    2009-08-01

    Female sexual arousal is a challenging construct to measure, partly because of the subtle nature of its indicators, vaginal lubrication and genital swelling. As a result, many instruments have been used in an attempt to accurately measure it; however, problems are associated with each. Furthermore, the relationship between subjective and physiological indicators of arousal appears to be influenced by the instrument used to measure physiological arousal. Specifically, instruments measuring physiological arousal internally yield lower correlations between measures of physiological and subjective arousal than instruments examining the external genitals. Laser Doppler imaging (LDI) is a direct measure of external genital blood flow. The purpose of this study was to investigate the usefulness of LDI for measuring genital blood flow in women in response to erotic visual stimuli, and to explore the relationship between physiological and subjective sexual arousal. Sixty-five participants watched three 15-minute films during LDI scanning. Two nature films (measuring acclimatization and baseline blood flow levels) and one randomly assigned experimental film (erotic, anxiety, humor, or neutral) were used. Participants rated their level of subjective arousal following the third film. Results indicated a significant effect of film condition on genital blood flow, P < 0.001, with the erotic condition differing significantly from the other three conditions. In terms of the relationship between physiological and subjective sexual arousal, physiological arousal was significantly predicted by subjective ratings of sexual arousal (P < 0.001). LDI appears to be able to differentiate blood flow during erotic and nonerotic conditions. In addition, physiological sexual arousal was significantly predicted by women's reported subjective sexual arousal. These findings suggest that LDI is a useful instrument for measuring female sexual arousal, and that women may be more aware of their level

  20. Direct top-quark width measurement at CDF.

    PubMed

    Aaltonen, T; Álvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Apresyan, A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bauer, G; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Bland, K R; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Brisuda, A; Bromberg, C; Brucken, E; Bucciantonio, M; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Cabrera, S; Calancha, C; Camarda, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Dagenhart, D; d'Ascenzo, N; Datta, M; de Barbaro, P; De Cecco, S; De Lorenzo, G; Dell'Orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Devoto, F; d'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Dorigo, T; Ebina, K; Elagin, A; Eppig, A; Erbacher, R; Errede, D; Errede, S; Ershaidat, N; Eusebi, R; Fang, H C; Farrington, S; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, S R; Halkiadakis, E; Hamaguchi, A; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harr, R F; Hatakeyama, K; Hays, C; Heck, M; Heinrich, J; Herndon, M; Hewamanage, S; Hidas, D; Hocker, A; Hopkins, W; Horn, D; Hou, S; Hughes, R E; Hurwitz, M; Husemann, U; Hussain, N; Hussein, M; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Klimenko, S; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kuhr, T; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, E; Lee, H S; Lee, J S; Lee, S W; Leo, S; Leone, S; Lewis, J D; Lin, C-J; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, Q; Liu, T; Lockwitz, S; Lockyer, N S; Loginov, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maeshima, K; Makhoul, K; Maksimovic, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Martínez, M; Martínez-Ballarín, R; Mastrandrea, P; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Movilla Fernandez, P; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Potamianos, K; Poukhov, O; Prokoshin, F; Pronko, A; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Rescigno, M; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Santi, L; Sartori, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shreyber, I; Simonenko, A; Sinervo, P; Sissakian, A; Sliwa, K; Smith, J R; Snider, F D; Soha, A; Somalwar, S; Sorin, V; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Sudo, Y; Sukhanov, A; Suslov, I; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thome, J; Thompson, G A; Thomson, E; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vila, I; Vilar, R; Vogel, M; Volpi, G; Wagner, P; Wagner, R L; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Wick, F; Williams, H H; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, H; Wright, T; Wu, X; Wu, Z; Yamamoto, K; Yamaoka, J; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanetti, A; Zeng, Y; Zucchelli, S

    2010-12-03

    We present a measurement of the top-quark width in the lepton+jets decay channel of tt events produced in p p collisions at Fermilab's Tevatron collider and collected by the CDF II detector. From a data sample corresponding to 4.3 fb(-1) of integrated luminosity, we identify 756 candidate events. The top-quark mass and the mass of the hadronically decaying W boson that comes from the top-quark decay are reconstructed for each event and compared with templates of different top-quark widths (Γ(t)) and deviations from nominal jet energy scale (Δ(JES)) to perform a simultaneous fit for both parameters, where Δ(JES) is used for the in situ calibration of the jet energy scale. By applying a Feldman-Cousins approach, we establish an upper limit at 95% confidence level (CL) of Γ(t) <7.6 GeV and a two-sided 68% CL interval of 0.3 GeV <Γ(t) <4.4  GeV for a top-quark mass of 172.5 GeV/c(2), which are consistent with the standard model prediction.

  1. Low Temperature Magnetic Calorimeters For Neutrino Mass Direct Measurement

    NASA Astrophysics Data System (ADS)

    Gastaldo, L.; Porst, J. P.; von Seggern, F.; Kirsch, A.; Ranitzsch, P.; Fleischmann, A.; Enss, C.; Seidel, G. M.

    2009-12-01

    In the last years the mixing of the three neutrino flavor eigenstates through a unitary matrix has been experimentally proved. Presently one of the greatest challenges in neutrino physics is to establish the absolute value of the masses of the three neutrino mass eigenstates. The kinematic determination of electron neutrino and antineutrino mass by means of the analysis of calorimetric spectra of isotopes which undergo a beta or electron-capture decay, with especially low energy available for the decay itself, represents an interesting method. In fact this method is less affected by theoretical models defining branching ratio among different decay modes. For the beta decay the isotope with the lowest Q-value present in nature is the 187Re (Q about 2.5 keV) while for the electron capture decay the best candidate known is the 163Ho (Q about 2.5 keV). Since those experiments need to be extremely precise, they might suffer from unexpected systematic errors. It is therefore important to investigate in detail the performance of the detectors and the calorimetric spectrum. We present our results obtained with low temperature magnetic calorimeters designed for measuring low energy beta and electron capture spectra. We also discuss problematic and the possibly present systematic uncertainties using this kind of detectors.

  2. Direct measurement of interlayer interaction in Permalloy/Gd nanodots

    NASA Astrophysics Data System (ADS)

    Lapa, Pavel; Ding, Junjia; Novosad, Valentine; Hoffmann, Axel

    2015-03-01

    Antiferromagnetic interaction at the interfaces of ferromagnetic transition metals(TM) and Gd is well known phenomenon. However, quantitative description of this interaction still lacks understanding. The main reason is that most experimental data were obtained by inspecting the hysteresis loops of TM/Gd multilayers. First, in plane domain structures of TM and Gd films complicates the description of the magnetization reversal process. Second, experimentally measured parameters are averaged over the domains obfuscating the microscopical picture. We make an effort to overcome these limitations by studying the magnetization reversal process of Permalloy/Gd nanodots. The dots were prepared by combination of optical lithography and magnetron sputtering. Experimentally it is observed that in these dots the antiferromagnetic interlayer interaction tunes magnetic vortex nucleation/annihilation fields. Rise of Gd magnetization at low temperature provides unusual temperature behavior of hysteresis loop. Micromagnetic models in which interlayer interaction energy acts as a fitting parameter is applied to simulate experimental hysteresis curves. The effect of nonmagnetic spacer between Permalloy and Gd is also considered and will be presented. This work was supported by the Department of Energy Office of Science, Materials Science and Engineering Division.

  3. Direct reaction measurements with a (132)Sn radioactive ion beam

    SciTech Connect

    Jones, K. L.; Chae, K. Y.; Kapler, R.; Ma, Zhanwen; Moazen, Brian; Cizewski, J. A.; Hatarik, Robert; Pain, S. D.; Swan, T. P.; Nunes, F. M.; Adekola, Aderemi S; Bardayan, Daniel W; Blackmon, Jeff C; Chae, Kyung Yuk; Liang, J Felix; Nesaraja, Caroline D; Pain, Steven D; Shapira, Dan; Smith, Michael Scott; Chipps, Kelly A; Erikson, Luke; Livesay, R. J.; Harlin, Christopher W; Patterson, N. P.; Thomas, J. S.; Kozub, R. L.; Shriner, Jr., John F

    2011-01-01

    The (d,p) neutron transfer and (d,d) elastic scattering reactions were measured in inverse kinematics using a radioactive ion beam of {sup 132}Sn at 630 MeV. The elastic scattering data were taken in a region where Rutherford scattering dominated the reaction, and nuclear effects account for less than 8% of the elastic scattering cross section. The magnitude of the nuclear effects, in the angular range studied, was found to be independent of the optical potential used, allowing the transfer data to be normalized in a reliable manner. The neutron-transfer reaction populated a previously unmeasured state at 1363 keV, which is most likely the single-particle 3p{sub 1/2} state expected above the N=82 shell closure. The data were analyzed using finite-range adiabatic-wave calculations and the results compared with the previous analysis using the distorted-wave Born approximation. Angular distributions for the ground and first-excited states are consistent with the previous tentative spin and parity assignments. Spectroscopic factors extracted from the differential cross sections are similar to those found for the one-neutron states beyond the benchmark doubly magic nucleus {sup 208}Pb.

  4. Direct reaction measurements with a 132Sn radioactive ion beam

    SciTech Connect

    Jones, Katherine L.; Nunes, Filomena M.; Adekola, Aderemi S.; Bardayan, Dan W.; Blackmon, Jeff; Chae, K. Y.; Chipps, Kelly A.; Cizewski, Jolie A.; Erikson, Luke E.; Harlin, C.; Hatarik, R.; Kapler, R.; Kozub, Raymond L.; Liang, J. F.; Livesay, Ronald J.; Ma, Zhongguo J.; Moazen, B. H.; Nesaraja, Caroline D.; Pain, Steven D.; Patterson, N. P.; Shapira, Dan; Shriner, Jr., John F.; Smith, Michael S.; Swan, Thomas P.; Thomas, Jeff S.

    2011-09-01

    The (d,p) neutron transfer and (d,d) elastic scattering reactions were measured in inverse kinematics using a radioactive ion beam of 132Sn at 630 MeV. The elastic scattering data were taken in a region where Rutherford scattering dominated the reaction, and nuclear effects account for less than 8% of the elastic scattering cross section. The magnitude of the nuclear effects, in the angular range studied, was found to be independent of the optical potential used, allowing the transfer data to be normalized in a reliable manner. The neutron-transfer reaction populated a previously unmeasured state at 1363 keV, which is most likely the single-particle 3p1/2 state expected above the N = 82 shell closure. The data were analyzed using finite-range adiabatic-wave calculations and the results compared with the previous analysis using the distorted-wave Born approximation. Angular distributions for the ground and first-excited states are consistent with the previous tentative spin and parity assignments. Spectroscopic factors extracted from the differential cross sections are similar to those found for the one-neutron states beyond the benchmark doubly magic nucleus 208Pb.

  5. Direct measurement of densification rate using a neutron scattering technique

    NASA Astrophysics Data System (ADS)

    Morris, E. M.; Wingham, D.

    2012-12-01

    A non-destructive method for measuring density, based on neutron-scattering, has been used in the dry snow area of the Greenland Ice Sheet to derive profiles of densification rate over periods ranging from a few days to 5 years. From these observations we have derived a constitutive law for the compaction of dry snow relating strainrate to stress, temperature and the "type" of snow, that is, whether the snow is part of a "winter" wind-compacted layer with rounded grains or a "summer" lower-density hoar layer. We suggest that the processes which allow compaction of the snow also promote sintering, by bringing the snow grains into closer proximity. Higher temperatures increase the initial densification rate for a snow element but also, over time, harden it more rapidly. The net result is a much-reduced apparent activation energy for snow densification, similar to that used by Herron and Langway in their empirical equation derived from ice core density profiles.

  6. DIRECT MEASUREMENT OF HEAT FLUX FROM COOLING LAKE THERMAL IMAGERY

    SciTech Connect

    Garrett, A; Eliel Villa-Aleman, E; Robert Kurzeja, R; Malcolm Pendergast, M; Timothy Brown, T; Saleem Salaymeh, S

    2007-12-19

    Laboratory experiments show a linear relationship between the total heat flux from a water surface to air and the standard deviation of the surface temperature field, {sigma}, derived from thermal images of the water surface over a range of heat fluxes from 400 to 1800 Wm{sup -2}. Thermal imagery and surface data were collected at two power plant cooling lakes to determine if the laboratory relationship between heat flux and {sigma} exists in large heated bodies of water. The heat fluxes computed from the cooling lake data range from 200 to 1400 Wm{sup -2}. The linear relationship between {sigma} and Q is evident in the cooling lake data, but it is necessary to apply band pass filtering to the thermal imagery to remove camera artifacts and non-convective thermal gradients. The correlation between {sigma} and Q is improved if a correction to the measured {sigma} is made that accounts for wind speed effects on the thermal convection. Based on more than a thousand cooling lake images, the correlation coefficients between {sigma} and Q ranged from about 0.8 to 0.9.

  7. FLUXEN portable equipment for direct X-ray spectra measurements

    NASA Astrophysics Data System (ADS)

    Aiello, S.; Bottigli, U.; Fauci, F.; Golosio, B.; Lo Presti, D.; Masala, G. L.; Oliva, P.; Raso, G.; Stumbo, S.; Tangaro, S.

    2004-02-01

    The proper use of imaging equipment in radiological units is based on an appropriate knowledge of the physical characteristics of the X-ray beam used. The FLUXEN PROJECT is working on a portable apparatus which, together with dedicated software, is able to perform an exact spectral reconstruction of the radiation produced in diagnostic X-ray tubes. The apparatus characterizes the energy spectrum of radiological tubes and also provides a measurement of the emitted flux. The acquisition system is based on a commercial CZT detector (3×3×2 mm 3), produced by AMPTEK, cooled by a Peltier cell, with a high efficiency in the diagnostic X-ray energy range and modified in the shaping electronics so as to obtain a faster response. The acquiring section lies on a NuDAQ I/O card with a sampling frequency of up to 20 MHz. The signal produced by the X-ray tube is wholly acquired and an off-line analysis is made so as to make possible an accurate recognition of pile-up events and a reconstruction of the emitted spectra. The reconstructed spectra of a General Electric Senographe DMR mammographic X-ray tube are shown.

  8. Direct measurements of ion dynamics in collisional magnetic presheaths

    SciTech Connect

    Siddiqui, M. Umair; Jackson, Cory D.; Kim, Justin F.; Hershkowitz, Noah

    2014-10-15

    Ion velocities and temperatures are measured in the presheath of a grounded plate downstream from an argon helicon plasma source using laser-induced fluorescence (P{sub rf}≈450→750 W, T{sub e}=2.5→5 eV, T{sub i}=0.1→0.6 eV, n{sub 0}≈1×10{sup 12}cm{sup −3}, p{sub n}=1→6.5 mTorr, λ=0.3→2 cm, ρ{sub i}≈ 0.5 cm). The plate is held 16°→60° relative to the 1 kG background axial magnetic field. The velocity profiles are compared to a 1D fluid model similar to those presented by Riemann [Phys. Plasmas 1, 552 (1994)] and Ahedo [Phys. Plasmas 4, 4419 (1997)] for the 1 mTorr dataset and are shown to agree well. The model is sensitive to parameters such as collision and ionization frequencies and simplified models, such one presented by Chodura [Phys. Fluids 25, 1628 (1982)], are shown to be inaccurate. E{sup →}×B{sup →} flows as large as 40% of c{sub s} at the sheath edge are inferred. Definitions for the term “magnetic presheath” and implications for ion flow to tokamak divertors and Hall thruster walls are discussed.

  9. Direct spectroscopic measurement of packaging-induced strains in high-power laser diode arrays

    NASA Astrophysics Data System (ADS)

    Tomm, Jens W.; Mueller, Ralf; Baerwolff, A.; Neuner, M.; Elsaesser, Thomas; Lorenzen, Dirk; Daiminger, Franz X.; Gerhardt, A.; Donecker, J.

    1999-04-01

    High-power diode lasers such as `cm-bar arrays' are important for many applications. The `p-side down packaging', i.e. the direct mounting of the epitaxial layer sequence on a heat spreader ensures sufficient thermal properties, however, in such a geometry, additional mechanical strain of the active region represents a central issue, affecting both the laser parameter as well as lifetime and reliability of the device. Thermally induced strain caused by device packaging is studied in high-power semiconductor laser arrays by a novel non-invasive technique. Photocurrent measurements with intentionally strained laser array devices for 808 nm emission reveal spectral shifts of all allowed optical transitions in the active region. These shifts serve as a measure for strain and are compared with model calculations. Depending on the specific heat spreader materials we find compressive or tensile mounting induced strain contributions. For a given packaging architecture, about one quarter of the mounting induced strain is transferred to the quantum well region of the device. Spatially resolved measurements allow to measure lateral strain gradients in the devices. Using this data for calibration we show that polarization resolved electroluminescence scans can be used as convenient measure for strain homogeneity test also in quantum-well devices.

  10. Laser Doppler velocity measurement without directional ambiguity by using frequency shifted incident beams

    NASA Technical Reports Server (NTRS)

    Mazumder, M. K.

    1970-01-01

    Laser Doppler heterodyning system for velocity measurements without directional ambiguity, employing incident beams of different frequencies through rotating diffraction grating or Bragg cell application

  11. Direct Measurements of Interplanetary Dust Particles in the Vicinity of Earth

    NASA Technical Reports Server (NTRS)

    McCracken, C. W.; Alexander, W. M.; Dubin, M.

    1961-01-01

    The direct measurements made by the Explorer VIII satellite provide the first sound basis for analyzing all available direct measurements of the distribution of interplanetary dust particles. The model average distribution curve established by such an analysis departs significantly from that predicted by the (uncertain) extrapolation of results from meteor observations. A consequence of this difference is that the daily accretion of interplanetary particulate matter by the earth is now considered to be mainly dust particles of the direct measurements range of particle size. Almost all the available direct measurements obtained with microphone systems on rockets, satellites, and spacecraft fit directly on the distribution curve defined by Explorer VIII data. The lack of reliable datum points departing significantly from the model average distribution curve means that available direct measurements show no discernible evidence of an appreciable geocentric concentration of interplanetary dust particles.

  12. Direct measurement of calcium transport across chloroplast inner-envelope vesicles

    SciTech Connect

    Roh, M.H.; Shingles, R.; Cleveland, M.J.; McCarty, R.E.

    1998-12-01

    The initial rate of Ca{sup 2+} movement across the inner-envelope membrane of pea (Pisum sativum L.) chloroplasts was directly measured by stopped-flow spectrofluorometry using membrane vesicles loaded with the Ca{sup 2+}-sensitive fluorophore fura-2. Calibration of fura-2 fluorescence was achieved by combining a ratiometric method with Ca{sup 2+}-selective minielectrodes to determine pCa values. The initial rate of Ca{sup 2+} influx in predominantly right-side-out inner-envelope membrane vesicles was greater than that in largely inside-out vesicles. Ca{sup 2+} movement was stimulated by an inwardly directed electrochemical proton gradient across the membrane vesicles, an effect that was diminished by the addition of valinomycin in the presence of K{sup +}. In addition, Ca{sup 2+} was shown to move across the membrane vesicles in the presence of K{sup +} diffusion potential gradient. The potential-stimulated rate of Ca{sup 2+} transport was slightly inhibited by diltiazem and greatly inhibited by ruthenium red. Other pharmacological agents such as LaCl{sub 3}, verapamil, and nifedipine had little or no effect. These results indicate that Ca{sup 2+} transport across the chloroplast inner envelope can occur by a potential-stimulated uniport mechanism.

  13. An electrical conductivity method for measuring the effects of additives on effective diffusivities in Portland cement pastes

    SciTech Connect

    Kyi, A.A. ); Batchelor, B. . Civil Engineering)

    1994-01-01

    Effective diffusivities are important in describing corrosion and leaching of contaminants in cementitious systems. An electrical conductivity procedure has been used to measure the effective diffusivities of compounds in cementitious systems containing the additives fly ash, silica fume, sodium silicate and bentonite. Silica fume was the most effective additive in reducing the effective diffusivity, but fly ash was the most cost effective. Diffusivities that have been measured with techniques that rely on flux of a compound through the solid were generally lower than those measured with the electrical conductivity procedure. Porosity and bulk density are not well correlated with effective diffusivity in systems containing additives.

  14. Direct Catalytic Asymmetric Doubly Vinylogous Michael Addition of α,β-Unsaturated γ-Butyrolactams to Dienones**

    PubMed Central

    Gu, Xiaodong; Guo, Tingting; Dai, Yuanyuan; Franchino, Allegra; Fei, Jie; Zou, Chuncheng; Dixon, Darren J; Ye, Jinxing

    2015-01-01

    An asymmetric doubly vinylogous Michael addition (DVMA) of α,β-unsaturated γ-butyrolactams to sterically congested β-substituted cyclic dienones with high site-, diastereo-, and enantioselectivity has been achieved. An unprecedented DVMA/vinylogous Michael addition/isomerization cascade reaction affords chiral fused tricyclic γ-lactams with four newly formed stereocenters. PMID:26184079

  15. Direct Measurement of Topological Phases in Discrete-Time Quantum Walks - Experiment

    NASA Astrophysics Data System (ADS)

    Flurin, Emmanuel; Ramasesh, Vinay V.; Hacohen Gourgy, Shay; Yao, Norman Y.; Siddiqi, Irfan

    We perform quantum walks in a cavity QED architecture. Here a transmon qubit plays the role of the quantum coin, while a set of coherent states in an electromagnetic cavity forms the walker's lattice. The strong dispersive coupling between the transmon and cavity naturally implements coin-dependent translations of the walker state. The walk is performed by applying qubit rotations at equally spaced intervals; interestingly, such systems simulate dynamics under effective lattice Hamiltonians which feature strong spin-orbit coupling, leading to non-trivial band topology. By adding an additional step-dependent coin operator, we perform the first direct measurement of a quantum walk Zak phase, delineating between topologically trivial and non-trivial walks. The geometric phase is detected by implementing the quantum walk with the initial state of the walker in a superposition of a coherent state and the vacuum state, which does not partake in the walk. The Zak phase acquired by the walker thus leaves an imprint in the interference fringes of the resulting Schrodinger cat state. We observe these fringes by directly measuring the cavity Wigner function. This research is supported by the ARO.

  16. Shock Tube Measurements of Ignition Processes in Diesel-Related Fuels and Additives

    DTIC Science & Technology

    2007-11-02

    temperatures and pressures of direct interest in HCCI engine simulations. Detailed examination of the pressure-time profiles shows evidence of significant...current DOE EERE program for the development of HCCI (homogeneous charge compression ignition) engines (D. Assanis, University Michigan). This program...Research Office Submitted by Professor R. K. Hanson Dr. D. F. Davidson Mechanical Engineering Department Stanford University

  17. 47 CFR 73.61 - AM directional antenna field strength measurements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false AM directional antenna field strength... RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.61 AM directional antenna field strength measurements. (a) Each AM station using a directional antenna with monitoring point...

  18. 47 CFR 73.61 - AM directional antenna field strength measurements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false AM directional antenna field strength... RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.61 AM directional antenna field strength measurements. (a) Each AM station using a directional antenna with monitoring point...

  19. 47 CFR 73.61 - AM directional antenna field strength measurements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false AM directional antenna field strength... RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.61 AM directional antenna field strength measurements. (a) Each AM station using a directional antenna with monitoring point...

  20. 47 CFR 73.61 - AM directional antenna field strength measurements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false AM directional antenna field strength... RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.61 AM directional antenna field strength measurements. (a) Each AM station using a directional antenna with monitoring point...