Conceptual Modeling (CM) for Military Modeling and Simulation (M&S) (Modelisation conceptuelle (MC) pour la modelisation et la simulation (M&S) militaires)

DTIC Science & Technology

2012-07-01

du monde de la modélisation et de la simulation et lui fournir des directives de mise en œuvre ; et fournir des ...définition ; rapports avec les normes ; spécification de procédure de gestion de la MC ; spécification d’artefact de MC. Considérations importantes...utilisant la présente directive comme référence. • Les VV&A (vérification, validation et acceptation) des MC doivent faire partie intégrante du

Spatial structure and temporal evolution of energetic particle injections in the inner magnetosphere during the 14 July 2013 substorm event

DOE PAGES

Gkioulidou, Matina; Ohtani, S.; Mitchell, D. G.; ...

2015-03-20

Recent results by the Van Allen Probes mission showed that the occurrence of energetic ion injections inside geosynchronous orbit could be very frequent throughout the main phase of a geomagnetic storm. Understanding, therefore, the formation and evolution of energetic particle injections is critical in order to quantify their effect in the inner magnetosphere. We present a case study of a substorm event that occurred during a weak storm (Dst ~ –40 nT) on 14 July 2013. Van Allen Probe B, inside geosynchronous orbit, observed two energetic proton injections within 10 min, with different dipolarization signatures and duration. The first onemore » is a dispersionless, short-timescale injection pulse accompanied by a sharp dipolarization signature, while the second one is a dispersed, longer-timescale injection pulse accompanied by a gradual dipolarization signature. We combined ground magnetometer data from various stations and in situ particle and magnetic field data from multiple satellites in the inner magnetosphere and near-Earth plasma sheet to determine the spatial extent of these injections, their temporal evolution, and their effects in the inner magnetosphere. Our results indicate that there are different spatial and temporal scales at which injections can occur in the inner magnetosphere and depict the necessity of multipoint observations of both particle and magnetic field data in order to determine these scales.« less

A New Concept of Dual Fuelled SI Engines Run on Gasoline and Alcohol

NASA Astrophysics Data System (ADS)

Stelmasiak, Zdzisław

2011-06-01

The paper discusses tests results of dual-fuel spark ignition engine with multipoint injection of alcohol and gasoline, injected in area of inlet valve. Fuelling of the engine was accomplished via prototype inlet system comprising duplex injectors controlled electronically. Implemented system enables feeding of the engine with gasoline only or alcohol only, and simultaneous combustion of a mixture of the both fuels with any fraction of alcohol. The tests were performed on four cylinders, spark ignition engine of Fiat 1100 MPI type. The paper presents comparative results of dual-fuel engine test when the engine runs on changing fraction of methyl alcohol. The tests have demonstrated an advantageous effect of alcohol additive on efficiency and TCH and NOx emission of the engine, especially in case of bigger shares of the alcohol and higher engine loads.

Modelisation of the SECMin molten salts environment

NASA Astrophysics Data System (ADS)

Lucas, M.; Slim, C.; Delpech, S.; di Caprio, D.; Stafiej, J.

2014-06-01

We develop a cellular automata modelisation of SECM experiments to study corrosion in molten salt media for generation IV nuclear reactors. The electrodes used in these experiments are cylindrical glass tips with a coaxial metal wire inside. As the result of simulations we obtain the current approach curves of the electrodes with geometries characterized by several values of the ratios of glass to metal area at the tip. We compare these results with predictions of the known analytic expressions, solutions of partial differential equations for flat uniform geometry of the substrate. We present the results for other, more complicated substrate surface geometries e. g. regular saw modulated surface, surface obtained by Eden model process, ...

Optical Characterization of a Multipoint Lean Direct Injector for Gas Turbine Combustors: Velocity and Fuel Drop Size Measurements

NASA Technical Reports Server (NTRS)

Heath, Christopher M.; Anderson, Robert C.; Locke, Randy J.; Hicks, Yolanda R.

2010-01-01

Performance of a multipoint, lean direct injection (MP-LDI) strategy for low emission aero-propulsion systems has been tested in a Jet-A fueled, lean flame tube combustion rig. Operating conditions for the series of tests included inlet air temperatures between 672 and 828 K, pressures between 1034 and 1379 kPa and total equivalence ratios between 0.41 and 0.45, resulting in equilibrium flame temperatures approaching 1800 K. Ranges of operation were selected to represent the spectrum of subsonic and supersonic flight conditions projected for the next-generation of commercial aircraft. This document reports laser-based measurements of in situ fuel velocities and fuel drop sizes for the NASA 9-point LDI hardware arranged in a 3 3 square grid configuration. Data obtained represent a region of the flame tube combustor with optical access that extends 38.1-mm downstream of the fuel injection site. All data were obtained within reacting flows, without particle seeding. Two diagnostic methods were employed to evaluate the resulting flow path. Three-component velocity fields have been captured using phase Doppler interferometry (PDI), and two-component velocity distributions using planar particle image velocimetry (PIV). Data from these techniques have also offered insight into fuel drop size and distribution, fuel injector spray angle and pattern, turbulence intensity, degree of vaporization and extent of reaction. This research serves to characterize operation of the baseline NASA 9- point LDI strategy for potential use in future gas-turbine combustor applications. An additional motive is the compilation of a comprehensive database to facilitate understanding of combustor fuel injector aerodynamics and fuel vaporization processes, which in turn may be used to validate computational fluid dynamics codes, such as the National Combustor Code (NCC), among others.

Le recours aux modeles dans l'enseignement de la biologie au secondaire : Conceptions d'enseignantes et d'enseignants et modes d'utilisation

NASA Astrophysics Data System (ADS)

Varlet, Madeleine

Le recours aux modeles et a la modelisation est mentionne dans la documentation scientifique comme un moyen de favoriser la mise en oeuvre de pratiques d'enseignement-apprentissage constructivistes pour pallier les difficultes d'apprentissage en sciences. L'etude prealable du rapport des enseignantes et des enseignants aux modeles et a la modelisation est alors pertinente pour comprendre leurs pratiques d'enseignement et identifier des elements dont la prise en compte dans les formations initiale et disciplinaire peut contribuer au developpement d'un enseignement constructiviste des sciences. Plusieurs recherches ont porte sur ces conceptions sans faire de distinction selon les matieres enseignees, telles la physique, la chimie ou la biologie, alors que les modeles ne sont pas forcement utilises ou compris de la meme maniere dans ces differentes disciplines. Notre recherche s'est interessee aux conceptions d'enseignantes et d'enseignants de biologie au secondaire au sujet des modeles scientifiques, de quelques formes de representations de ces modeles ainsi que de leurs modes d'utilisation en classe. Les resultats, que nous avons obtenus au moyen d'une serie d'entrevues semi-dirigees, indiquent que globalement leurs conceptions au sujet des modeles sont compatibles avec celle scientifiquement admise, mais varient quant aux formes de representations des modeles. L'examen de ces conceptions temoigne d'une connaissance limitee des modeles et variable selon la matiere enseignee. Le niveau d'etudes, la formation prealable, l'experience en enseignement et un possible cloisonnement des matieres pourraient expliquer les differentes conceptions identifiees. En outre, des difficultes temporelles, conceptuelles et techniques peuvent freiner leurs tentatives de modelisation avec les eleves. Toutefois, nos resultats accreditent l'hypothese que les conceptions des enseignantes et des enseignants eux-memes au sujet des modeles, de leurs formes de representation et de leur approche constructiviste en enseignement representent les plus grands obstacles a la construction des modeles en classe. Mots-cles : Modeles et modelisation, biologie, conceptions, modes d'utilisation, constructivisme, enseignement, secondaire.

High-Reynolds-number turbulent-boundary-layer wall pressure fluctuations with skin-friction reduction by air injection.

PubMed

Winkel, Eric S; Elbing, Brian R; Ceccio, Steven L; Perlin, Marc; Dowling, David R

2008-05-01

The hydrodynamic pressure fluctuations that occur on the solid surface beneath a turbulent boundary layer are a common source of flow noise. This paper reports multipoint surface pressure fluctuation measurements in water beneath a high-Reynolds-number turbulent boundary layer with wall injection of air to reduce skin-friction drag. The experiments were conducted in the U.S. Navy's Large Cavitation Channel on a 12.9-m-long, 3.05-m-wide hydrodynamically smooth flat plate at freestream speeds up to 20 ms and downstream-distance-based Reynolds numbers exceeding 200 x 10(6). Air was injected from one of two spanwise slots through flush-mounted porous stainless steel frits (approximately 40 microm mean pore diameter) at volume flow rates from 17.8 to 142.5 l/s per meter span. The two injectors were located 1.32 and 9.78 m from the model's leading edge and spanned the center 87% of the test model. Surface pressure measurements were made with 16 flush-mounted transducers in an "L-shaped" array located 10.7 m from the plate's leading edge. When compared to no-injection conditions, the observed wall-pressure variance was reduced by as much as 87% with air injection. In addition, air injection altered the inferred convection speed of pressure fluctuation sources and the streamwise coherence of pressure fluctuations.

First Plasma Results from the HIT-SI Spheromak

NASA Astrophysics Data System (ADS)

Sieck, P. E.; Hamp, W. T.; Izzo, V. A.; Jarboe, T. R.; Nelson, B. A.; O'Neill, R. G.; Redd, A. J.; Smith, R. J.

2003-10-01

HIT-SI is the newest device in the Helicity Injected Torus (HIT) program. HIT-SI is a ``bow tie'' spheromak formed and sustained by Steady Inductive Helicity Injection (SIHI) current drive. SIHI injects helicity at a nearly constant rate with no open field lines intersecting the boundary. (T. R. Jarboe, Fusion Technology 36) (1), p. 85, 1999 HIT-SI has been designed with a bow tie geometry to achieve stable high-β (>10%) spheromak equilibria. (U. Shumlak and T. R. Jarboe, Phys. Plasmas 7) (7), p. 2959, 2000 Diagnostics currently include surface magnetic probes and flux loops, visible light imaging, H-alpha line radiation monitors, voltage measurements across insulating breaks, injector current Rogowski coils, and injector flux loops. HIT-SI is currently operating in parallel with experiments on HIT-II. At the conclusion of HIT-II operations, HIT-SI will inherit a multi-point Thomson Scattering system, a scanning two-chord FIR interferometer, and other advanced diagnostics, as well as more power supplies to extend the discharge duration. Results are presented which characterize injector operation and possible evidence for spheromak formation.

TLNS3D/CDISC Multipoint Design of the TCA Concept

NASA Technical Reports Server (NTRS)

Campbell, Richard L.; Mann, Michael J.

1999-01-01

This paper presents the work done to date by the authors on developing an efficient approach to multipoint design and applying it to the design of the HSR TCA (High Speed Research Technology Concept Aircraft) configuration. While the title indicates that this exploratory study has been performed using the TLNS3DMB flow solver and the CDISC (Constrained Direct Iterative Surface Curvature) design method, the CDISC method could have been used with any flow solver, and the multipoint design approach does not require the use of CDISC. The goal of the study was to develop a multipoint design method that could achieve a design in about the same time as 10 analysis runs.

On shifted Jacobi spectral method for high-order multi-point boundary value problems

NASA Astrophysics Data System (ADS)

Doha, E. H.; Bhrawy, A. H.; Hafez, R. M.

2012-10-01

This paper reports a spectral tau method for numerically solving multi-point boundary value problems (BVPs) of linear high-order ordinary differential equations. The construction of the shifted Jacobi tau approximation is based on conventional differentiation. This use of differentiation allows the imposition of the governing equation at the whole set of grid points and the straight forward implementation of multiple boundary conditions. Extension of the tau method for high-order multi-point BVPs with variable coefficients is treated using the shifted Jacobi Gauss-Lobatto quadrature. Shifted Jacobi collocation method is developed for solving nonlinear high-order multi-point BVPs. The performance of the proposed methods is investigated by considering several examples. Accurate results and high convergence rates are achieved.

Experimental research and numerical optimisation of multi-point sheet metal forming implementation using a solid elastic cushion system

NASA Astrophysics Data System (ADS)

Tolipov, A. A.; Elghawail, A.; Shushing, S.; Pham, D.; Essa, K.

2017-09-01

There is a growing demand for flexible manufacturing techniques that meet the rapid changes in customer needs. A finite element analysis numerical optimisation technique was used to optimise the multi-point sheet forming process. Multi-point forming (MPF) is a flexible sheet metal forming technique where the same tool can be readily changed to produce different parts. The process suffers from some geometrical defects such as wrinkling and dimpling, which have been found to be the cause of the major surface quality problems. This study investigated the influence of parameters such as the elastic cushion hardness, blank holder force, coefficient of friction, cushion thickness and radius of curvature, on the quality of parts formed in a flexible multi-point stamping die. For those reasons, in this investigation, a multipoint forming stamping process using a blank holder was carried out in order to study the effects of the wrinkling, dimpling, thickness variation and forming force. The aim was to determine the optimum values of these parameters. Finite element modelling (FEM) was employed to simulate the multi-point forming of hemispherical shapes. Using the response surface method, the effects of process parameters on wrinkling, maximum deviation from the target shape and thickness variation were investigated. The results show that elastic cushion with proper thickness and polyurethane with the hardness of Shore A90. It has also been found that the application of lubrication cans improve the shape accuracy of the formed workpiece. These final results were compared with the numerical simulation results of the multi-point forming for hemispherical shapes using a blank-holder and it was found that using cushion hardness realistic to reduce wrinkling and maximum deviation.

Global Magnetosphere Evolution During 22 June 2015 Geomagnetic Storm as Seen From Multipoint Observations and Comparison With MHD-Ring Rurrent Model

NASA Astrophysics Data System (ADS)

Buzulukova, N.; Moore, T. E.; Dorelli, J.; Fok, M. C. H.; Sibeck, D. G.; Angelopoulos, V.; Goldstein, J.; Valek, P. W.; McComas, D. J.

2015-12-01

On 22-23 June 2015 a severe geomagnetic storm occurred with Dst minimum of approximately -200nT. During this extreme event, multipoint observations of magnetospheric dynamics were obtained by a fleet of Geospace spacecraft including MMS, TWINS, Van-Allen and THEMIS. We present analysis of satellite data during that event, and use a global coupled MHD-ring current model (BATSRUS-CRCM) to connect multipoint observations from different parts of the magnetosphere. The analysis helps to identify different magnetospheric domains from multipoint measurements and various magnetospheric boundary motions. We will explore how the initial disturbance from the solar wind propagates through the magnetosphere causing energization of plasma in the inner magnetosphere and producing an extreme geomagnetic storm.

Energy limits of electron acceleration in the plasma sheet during substorms: A case study with the Magnetospheric Multiscale (MMS) mission

NASA Astrophysics Data System (ADS)

Turner, D. L.; Fennell, J. F.; Blake, J. B.; Clemmons, J. H.; Mauk, B. H.; Cohen, I. J.; Jaynes, A. N.; Craft, J. V.; Wilder, F. D.; Baker, D. N.; Reeves, G. D.; Gershman, D. J.; Avanov, L. A.; Dorelli, J. C.; Giles, B. L.; Pollock, C. J.; Schmid, D.; Nakamura, R.; Strangeway, R. J.; Russell, C. T.; Artemyev, A. V.; Runov, A.; Angelopoulos, V.; Spence, H. E.; Torbert, R. B.; Burch, J. L.

2016-08-01

We present multipoint observations of earthward moving dipolarization fronts and energetic particle injections from NASA's Magnetospheric Multiscale mission with a focus on electron acceleration. From a case study during a substorm on 02 August 2015, we find that electrons are only accelerated over a finite energy range, from a lower energy threshold at 7-9 keV up to an upper energy cutoff in the hundreds of keV range. At energies lower than the threshold energy, electron fluxes decrease, potentially due to precipitation by strong parallel electrostatic wavefields or initial sources in the lobes. Electrons at energies higher than the threshold are accelerated cumulatively by a series of impulsive magnetic dipolarization events. This case demonstrates how the upper energy cutoff increases, in this case from 130 keV to >500 keV, with each dipolarization/injection during sustained activity. We also present a simple model accounting for these energy limits that reveals that electron energization is dominated by betatron acceleration.

Energy Limits of Electron Acceleration in the Plasma Sheet During Substorms: A Case Study with the Magnetospheric Multiscale (MMS) Mission

NASA Technical Reports Server (NTRS)

Turner, D. L.; Fennell, J. F.; Blake, J. B.; Clemmons, J. H.; Mauk, B. H.; Cohen, I. J.; Jaynes, A. N.; Craft, J. V.; Wilder, F. D.; Baker, D. N.;

47 CFR 1.824 - Random selection procedures for Multichannel Multipoint Distribution Service and Multipoint...

Code of Federal Regulations, 2010 CFR

2010-10-01

... an ownership interest of more than 50 percent in the media of mass communication whose service areas... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Complaints, Applications, Tariffs...

NOx Emissions Performance and Correlation Equations for a Multipoint LDI Injector

NASA Technical Reports Server (NTRS)

He, Zhuohui J.; Chang, Clarence T.; Follen, Caitlin E.

2014-01-01

Lean Direct Injection (LDI) is a combustor concept that reduces nitrogen oxides (NOx) emissions. This paper looks at a 3-zone multipoint LDI concept developed by Parker Hannifin Corporation. The concept was tested in a flame-tube test facility at NASA Glenn Research Center. Due to test facility limitations, such as inlet air temperature and pressure, the flame-tube test was not able to cover the full set of engine operation conditions. Three NOx correlation equations were developed based on assessing NOx emissions dependencies on inlet air pressure (P3), inlet air temperature (T3), and fuel air equivalence ratio (phi) to estimate the NOx emissions at the unreachable high engine power conditions. As the results, the NOx emissions are found to be a strong function of combustion inlet air temperature and fuel air equivalence ratio but a weaker function of inlet air pressure. With these three equations, the NOx emissions performance of this injector concept is calculated as a 66 percent reduction relative to the ICAO CAEP-6 standard using a 55:1 pressure-ratio engine cycle. Uncertainty in the NOx emissions estimation increases as the extrapolation range departs from the experimental conditions. Since maximum inlet air pressure tested was less than 50 percent of the full power engine inlet air pressure, a future experiment at higher inlet air pressure conditions is needed to confirm the NOx emissions dependency on inlet air pressure.

NOx Emissions Performance and Correlation Equations for a Multipoint LDI Injector

NASA Technical Reports Server (NTRS)

He, Zhuohui Joe; Chang, Clarence T.; Follen, Caitlin E.

2015-01-01

Lean Direct Injection (LDI) is a combustor concept that reduces nitrogen oxides (NOx) emissions.This paper looks at a 3-zone multipoint LDI concept developed by Parker Hannifin Corporation. The concept was tested in a flame-tube test facility at NASA Glenn Research Center. Due to test facility limitations, such as inlet air temperature and pressure, the flame-tube test was not able to cover the full set of engine operation conditions. Three NOx correlation equations were developed based on assessing NOx emissions dependencies on inlet air pressure (P3), inlet air temperature (T3), and fuel air equivalence ratio(theta) to estimate the NOx emissions at the unreachable high engine power conditions. As the results, the NOx emissions are found to be a strong function of combustion inlet air temperature and fuel air equivalence ratio but a weaker function of inlet air pressure. With these three equations, the NOx emissions performance of this injector concept is calculated as a 66 reduction relative to the ICAO CAEP-6 standard using a 55:1 pressure-ratio engine cycle. Uncertainty in the NOx emissions estimation increases as the extrapolation range departs from the experimental conditions. Since maximum inlet air pressure tested was less than 50 of the full power engine inlet air pressure, a future experiment at higher inlet air pressure conditions is needed to confirm the NOx emissions dependency on inlet air pressure.

NOx Emissions Performance and Correlation Equations for a Multipoint LDI Injector

NASA Technical Reports Server (NTRS)

He, Zhuohui J.; Chang, Clarence T.; Follen, Caitlin E.

2015-01-01

Lean Direct Injection (LDI) is a combustor concept that reduces nitrogen oxides (NOx) emissions. This paper looks at a 3-zone multipoint LDI concept developed by Parker Hannifin Corporation. The concept was tested in a flame-tube test facility at NASA Glenn Research Center. Due to test facility limitations, such as inlet air temperature and pressure, the flame-tube test was not able to cover the full set of engine operation conditions. Three NOx correlation equations were developed based on assessing NOx emissions dependencies on inlet air pressure (P3), inlet air temperature (T3), and fuel air equivalence ratio (?) to estimate the NOx emissions at the unreachable high engine power conditions. As the results, the NOx emissions are found to be a strong function of combustion inlet air temperature and fuel air equivalence ratio but a weaker function of inlet air pressure. With these three equations, the NOx emissions performance of this injector concept is calculated as a 66% reduction relative to the ICAO CAEP-6 standard using a 55:1 pressure-ratio engine cycle. Uncertainty in the NOx emissions estimation increases as the extrapolation range departs from the experimental conditions. Since maximum inlet air pressure tested was less than 50% of the full power engine inlet air pressure, a future experiment at higher inlet air pressure conditions is needed to confirm the NOx emissions dependency on inlet air pressure.

NASA Multipoint LDI Development

NASA Technical Reports Server (NTRS)

Tacina, Robert

2001-01-01

Multipoint Lean-Direct-Injection (LDI) is a combustor concept in which a large number of fuel injectors and fuel-air mixers are used to quickly and uniformly mix the fuel and air so that ultralow levels of NO, are produced. Each fuel injector has an air swirler associated with it for fuel-air mixing and to establish a small recirculation and burning zone. A concept in which there are 36 fuel injectors in the space of a conventional single fuel injector has been tested in a flame tube. A greater than 80 percent reduction in NO, at high power conditions (400 psia, 1000 "Finlet) was achieved. Alternate concepts with 9,25,36 or 49 fuel injectors are being investigated in flame tube tests for their low NO, potential and with fuel staging to improve the turn-down ratio at low power conditions. A preliminary sector concept of a large engine design has been successfully tested at inlet conditions of 700 psia and 1100 O F . This concept had one half the number of fuel injectors per square inch as the flame tube configuration with 36 fuel injectors, and the NO, reduction was 65 percent of the ICAO standard. Future regional engine size sector tests are planned for the 2nd quarter of FY02 and large engine size sector tests for the 1st quarter of FY03.

NOx Emissions Performance and Correlation Equations for a Multipoint LDI Injector

NASA Technical Reports Server (NTRS)

He, Zhuohui J.; Chang, Clarence T.; Follen, Caitlin E.

2014-01-01

Lean Direct Injection (LDI) is a combustor concept that reduces nitrogen oxides (NOx) emissions. This paper looks at a 3-zone multipoint LDI concept developed by Parker Hannifin Corporation. The concept was tested in a flame-tube test facility at NASA Glenn Research Center. Due to test facility limitations, such as inlet air temperature and pressure, the flame-tube test was not able to cover the full set of engine operation conditions. Three NOx correlation equations were developed based on assessing NOx emissions dependencies on inlet air pressure (P3), inlet air temperature (T3), and fuel air equivalence ratio (?) to estimate the NOx emissions at the unreachable high engine power conditions. As the results, the NOx emissions are found to be a strong function of combustion inlet air temperature and fuel air equivalence ratio but a weaker function of inlet air pressure. With these three equations, the NOx emissions performance of this injector concept is calculated as a 66 percent reduction relative to the ICAO CAEP-6 standard using a 55:1 pressure-ratio engine cycle. Uncertainty in the NOx emissions estimation increases as the extrapolation range departs from the experimental conditions. Since maximum inlet air pressure tested was less than 50 percent of the full power engine inlet air pressure, a future experiment at higher inlet air pressure conditions is needed to confirm the NOx emissions dependency on inlet air pressure.

Multipoint fiber-optic laser-ultrasonic actuator based on fiber core-opened tapers.

PubMed

Tian, Jiajun; Dong, Xiaolong; Gao, Shimin; Yao, Yong

2017-11-27

In this study, a novel fiber-optic, multipoint, laser-ultrasonic actuator based on fiber core-opened tapers (COTs) is proposed and demonstrated. The COTs were fabricated by splicing single-mode fibers using a standard fiber splicer. A COT can effectively couple part of a core mode into cladding modes, and the coupling ratio can be controlled by adjusting the taper length. Such characteristics are used to obtain a multipoint, laser-ultrasonic actuator with balanced signal strength by reasonably controlling the taper lengths of the COTs. As a prototype, we constructed an actuator that generated ultrasound at four points with a balanced ultrasonic strength by connecting four COTs with coupling ratios of 24.5%, 33.01%, 49.51%, and 87.8% in a fiber link. This simple-to-fabricate, multipoint, laser-ultrasonic actuator with balanced ultrasound signal strength has potential applications in fiber-optic ultrasound testing technology.

Multi-Gigabit Free-Space Optical Data Communication and Network System

DTIC Science & Technology

2016-04-01

IR), Ultraviolet ( UV ), Laser Transceiver, Adaptive Beam Tracking, Electronic Attack (EA), Cyber Attack, Multipoint-to-Multipoint Network, Adaptive...FileName.pptx Free Space Optical Datalink Timeline Phase 1 Point-to-point demonstration 2012 Future Adaptive optic & Quantum Cascade Laser

Distribution of Model-based Multipoint Heterogeneity Lod Scores

PubMed Central

Xing, Chao; Morris, Nathan; Xing, Guan

2011-01-01

The distribution of two-point heterogeneity lod scores (HLOD) has been intensively investigated because the conventional χ2 approximation to the likelihood ratio test is not directly applicable. However, there was no study investigating the distribution of the multipoint HLOD despite its wide application. Here we want to point out that, compared with the two-point HLOD, the multipoint HLOD essentially tests for homogeneity given linkage and follows a relatively simple limiting distribution 12χ02+12χ12, which can be obtained by established statistical theory. We further examine the theoretical result by simulation studies. PMID:21104892

Multipoint to multipoint routing and wavelength assignment in multi-domain optical networks

NASA Astrophysics Data System (ADS)

Qin, Panke; Wu, Jingru; Li, Xudong; Tang, Yongli

2018-01-01

In multi-point to multi-point (MP2MP) routing and wavelength assignment (RWA) problems, researchers usually assume the optical networks to be a single domain. However, the optical networks develop toward to multi-domain and larger scale in practice. In this context, multi-core shared tree (MST)-based MP2MP RWA are introduced problems including optimal multicast domain sequence selection, core nodes belonging in which domains and so on. In this letter, we focus on MST-based MP2MP RWA problems in multi-domain optical networks, mixed integer linear programming (MILP) formulations to optimally construct MP2MP multicast trees is presented. A heuristic algorithm base on network virtualization and weighted clustering algorithm (NV-WCA) is proposed. Simulation results show that, under different traffic patterns, the proposed algorithm achieves significant improvement on network resources occupation and multicast trees setup latency in contrast with the conventional algorithms which were proposed base on a single domain network environment.

Distribution of model-based multipoint heterogeneity lod scores.

PubMed

Xing, Chao; Morris, Nathan; Xing, Guan

2010-12-01

The distribution of two-point heterogeneity lod scores (HLOD) has been intensively investigated because the conventional χ(2) approximation to the likelihood ratio test is not directly applicable. However, there was no study investigating th e distribution of the multipoint HLOD despite its wide application. Here we want to point out that, compared with the two-point HLOD, the multipoint HLOD essentially tests for homogeneity given linkage and follows a relatively simple limiting distribution ½χ²₀+ ½χ²₁, which can be obtained by established statistical theory. We further examine the theoretical result by simulation studies. © 2010 Wiley-Liss, Inc.

47 CFR 22.623 - System configuration.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 2 2013-10-01 2013-10-01 false System configuration. 22.623 Section 22.623... Paging and Radiotelephone Service Point-To-Multipoint Operation § 22.623 System configuration. This section requires a minimum configuration for point-to-multipoint systems using the channels listed in § 22...

47 CFR 22.623 - System configuration.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 2 2012-10-01 2012-10-01 false System configuration. 22.623 Section 22.623... Paging and Radiotelephone Service Point-To-Multipoint Operation § 22.623 System configuration. This section requires a minimum configuration for point-to-multipoint systems using the channels listed in § 22...

47 CFR 22.623 - System configuration.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 2 2014-10-01 2014-10-01 false System configuration. 22.623 Section 22.623... Paging and Radiotelephone Service Point-To-Multipoint Operation § 22.623 System configuration. This section requires a minimum configuration for point-to-multipoint systems using the channels listed in § 22...

Public Data Set: Control and Automation of the Pegasus Multi-point Thomson Scattering System

DOE Data Explorer

Bodner, Grant M. [University of Wisconsin-Madison] (ORCID:0000000324979172); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Reusch, Joshua A. [University of Wisconsin-Madison] (ORCID:0000000284249422); Rodriguez Sanchez, Cuauhtemoc [University of Wisconsin-Madison] (ORCID:0000000334712586); Schlossberg, David J. [University of Wisconsin-Madison] (ORCID:0000000287139448)

2016-08-12

This public data set contains openly-documented, machine readable digital research data corresponding to figures published in G.M. Bodner et al., 'Control and Automation of the Pegasus Multi-point Thomson Scattering System,' Rev. Sci. Instrum. 87, 11E523 (2016).

47 CFR 22.623 - System configuration.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false System configuration. 22.623 Section 22.623... Paging and Radiotelephone Service Point-To-Multipoint Operation § 22.623 System configuration. This section requires a minimum configuration for point-to-multipoint systems using the channels listed in § 22...

Energy limits of electron acceleration in the plasma sheet during substorms: A case study with the Magnetospheric Multiscale (MMS) mission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turner, Drew Lawson; Fennell, J. F.; Blake, J. B.

Here, we present multipoint observations of earthward moving dipolarization fronts and energetic particle injections from NASA's Magnetospheric Multiscale mission with a focus on electron acceleration. From a case study during a substorm on 02 August 2015, we find that electrons are only accelerated over a finite energy range, from a lower energy threshold at ~7–9 keV up to an upper energy cutoff in the hundreds of keV range. At energies lower than the threshold energy, electron fluxes decrease, potentially due to precipitation by strong parallel electrostatic wavefields or initial sources in the lobes. Electrons at energies higher than the thresholdmore » are accelerated cumulatively by a series of impulsive magnetic dipolarization events. This case demonstrates how the upper energy cutoff increases, in this case from ~130 keV to >500 keV, with each dipolarization/injection during sustained activity. We also present a simple model accounting for these energy limits that reveals that electron energization is dominated by betatron acceleration.« less

Energy limits of electron acceleration in the plasma sheet during substorms: A case study with the Magnetospheric Multiscale (MMS) mission

DOE PAGES

Turner, Drew Lawson; Fennell, J. F.; Blake, J. B.; ...

2016-08-01

Here, we present multipoint observations of earthward moving dipolarization fronts and energetic particle injections from NASA's Magnetospheric Multiscale mission with a focus on electron acceleration. From a case study during a substorm on 02 August 2015, we find that electrons are only accelerated over a finite energy range, from a lower energy threshold at ~7–9 keV up to an upper energy cutoff in the hundreds of keV range. At energies lower than the threshold energy, electron fluxes decrease, potentially due to precipitation by strong parallel electrostatic wavefields or initial sources in the lobes. Electrons at energies higher than the thresholdmore » are accelerated cumulatively by a series of impulsive magnetic dipolarization events. This case demonstrates how the upper energy cutoff increases, in this case from ~130 keV to >500 keV, with each dipolarization/injection during sustained activity. We also present a simple model accounting for these energy limits that reveals that electron energization is dominated by betatron acceleration.« less

Order reduction of z-transfer functions via multipoint Jordan continued-fraction expansion

NASA Technical Reports Server (NTRS)

Lee, Ying-Chin; Hwang, Chyi; Shieh, Leang S.

1992-01-01

The order reduction problem of z-transfer functions is solved by using the multipoint Jordan continued-fraction expansion (MJCFE) technique. An efficient algorithm that does not require the use of complex algebra is presented for obtaining an MJCFE from a stable z-transfer function with expansion points selected from the unit circle and/or the positive real axis of the z-plane. The reduced-order models are exactly the multipoint Pade approximants of the original system and, therefore, they match the (weighted) time-moments of the impulse response and preserve the frequency responses of the system at some characteristic frequencies, such as gain crossover frequency, phase crossover frequency, bandwidth, etc.

Time Sensitive Course of Action Development and Evaluation

DTIC Science & Technology

2010-10-01

Applications militaires de la modelisation humaine ). RTO-MP-HFM-202 14. ABSTRACT The development of courses of action that integrate military with...routes between the capital town C of the province and a neighboring country M. Both roads are historically significant smuggling routes. There were

Biological Rhythms Modelisation of Vigilance and Sleep in Microgravity State with COSINOR and Volterra's Kernels Methods

NASA Astrophysics Data System (ADS)

Gaudeua de Gerlicz, C.; Golding, J. G.; Bobola, Ph.; Moutarde, C.; Naji, S.

2008-06-01

The spaceflight under microgravity cause basically biological and physiological imbalance in human being. Lot of study has been yet release on this topic especially about sleep disturbances and on the circadian rhythms (alternation vigilance-sleep, body, temperature...). Factors like space motion sickness, noise, or excitement can cause severe sleep disturbances. For a stay of longer than four months in space, gradual increases in the planned duration of sleep were reported. [1] The average sleep in orbit was more than 1.5 hours shorter than the during control periods on earth, where sleep averaged 7.9 hours. [2] Alertness and calmness were unregistered yield clear circadian pattern of 24h but with a phase delay of 4h.The calmness showed a biphasic component (12h) mean sleep duration was 6.4 structured by 3-5 non REM/REM cycles. Modelisations of neurophysiologic mechanisms of stress and interactions between various physiological and psychological variables of rhythms have can be yet release with the COSINOR method. [3

Multi-Point E-Conferencing with Initial Teacher Training Students in England: Pitfalls and Potential

ERIC Educational Resources Information Center

Pratt, Nick

2008-01-01

This article reports on attempts to initiate multi-point e-conferencing between English teacher education students on school placements, their host teachers and their university tutors. A sociocultural perspective is adopted in analysing the project, using the metaphor of a "professional knowledge landscape" [Clandinin, D. J., &…

Public Data Set: A Novel, Cost-Effective, Multi-Point Thomson Scattering System on the Pegasus Toroidal Experiment

DOE Data Explorer

Schlossberg, David J. [University of Wisconsin-Madison] (ORCID:0000000287139448); Bodner, Grant M. [University of Wisconsin-Madison] (ORCID:0000000324979172); Reusch, Joshua A. [University of Wisconsin-Madison] (ORCID:0000000284249422); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Rodriguez Sanchez, Cuauhtemoc [University of Wisconsin-Madison] (ORCID:0000000334712586)

2016-09-16

This public data set contains openly-documented, machine readable digital research data corresponding to figures published in D.J. Schlossberg et. al., 'A Novel, Cost-Effective, Multi-Point Thomson Scattering System on the Pegasus Toroidal Experiment,' Rev. Sci. Instrum. 87, 11E403 (2016).

Multipoint Multimedia Conferencing System with Group Awareness Support and Remote Management

ERIC Educational Resources Information Center

Osawa, Noritaka; Asai, Kikuo

2008-01-01

A multipoint, multimedia conferencing system called FocusShare is described that uses IPv6/IPv4 multicasting for real-time collaboration, enabling video, audio, and group awareness information to be shared. Multiple telepointers provide group awareness information and make it easy to share attention and intention. In addition to pointing with the…

Improved method to fully compensate the spatial phase nonuniformity of LCoS devices with a Fizeau interferometer.

PubMed

Lu, Qiang; Sheng, Lei; Zeng, Fei; Gao, Shijie; Qiao, Yanfeng

2016-10-01

Liquid crystal on silicon (LCoS) devices usually show spatial phase nonuniformity (SPNU) in applications of phase modulation, which comprises the phase retardance nonuniformity (PRNU) as a function of the applied voltage and inherent wavefront distortion (WFD) introduced by the device itself. We propose a multipoint calibration method utilizing a Fizeau interferometer to compensate SPNU of the device. Calibration of PRNU is realized by defining a grid of 3×6 cells onto the aperture and then calculating phase retardance of each cell versus a gradient gray pattern. With designing an adjusted gray pattern calculated by the calibrated multipoint phase retardance function, compensation of inherent WFD is achieved. The peak-to-valley (PV) value of the residual WFD compensated by the multipoint calibration method is significantly reduced from 2.5λ to 0.140λ, while the PV value of the residual WFD after global calibration is reduced to 0.364λ. Experimental results of the generated finite-energy 2D Airy beams in Fourier space demonstrate the effectiveness of this multipoint calibration method.

Overview of MST Results and Plans

NASA Astrophysics Data System (ADS)

Sarff, J. S.

2008-11-01

Improved confinement with high beta has been established in MST over its full range of plasma current capability using transient inductive current profile control. Both thermal electron and ion confinement are increased, and energetic electrons are observed to 100 keV. The global energy confinement time is 12 ms at high current and high temperature (Te=2 keV, Ti =1 keV), with βtot=10% (only Ohmic heating). Maximum βtot=26% is attained at lower current and temperature with D2 pellet injection, without evidence of hard-beta-limit phenomena. Momentum transport associated with MHD tearing shows the fascinating behavior that the Maxwell and Reynolds turbulent stresses are both large but oppositely directed in sawtooth magnetic relaxation events. Momentum is transported rapidly in these events, presumably through the imbalance in the stresses. Electron temperature fluctuations associated with MHD tearing are measured using a multi-point, multi-pulse Thomson scattering diagnostic. A 5-250 kHz pulse-burst laser is under construction to extend the Thomson capability to high frequency. Lower hybrid and electron Bernstein wave injection are under development to provide more sustained current profile control and heating. X-ray emission from the plasma is observed for both waves at 175 kW injected power. Substantial new experimental capability will be provided by a recently installed programmable power supply for the toroidal field, a new 1 MW, 20 ms neutral beam injection system, and upgraded OFCD system. Supported by U.S. DoE and NSF.

Novel approaches to analysis by flow injection gradient titration.

PubMed

Wójtowicz, Marzena; Kozak, Joanna; Kościelniak, Paweł

2007-09-26

Two novel procedures for flow injection gradient titration with the use of a single stock standard solution are proposed. In the multi-point single-line (MP-SL) method the calibration graph is constructed on the basis of a set of standard solutions, which are generated in a standard reservoir and subsequently injected into the titrant. According to the single-point multi-line (SP-ML) procedure the standard solution and a sample are injected into the titrant stream from four loops of different capacities, hence four calibration graphs are able to be constructed and the analytical result is calculated on the basis of a generalized slope of these graphs. Both approaches have been tested on the example of spectrophotometric acid-base titration of hydrochloric and acetic acids with using bromothymol blue and phenolphthalein as indicators, respectively, and sodium hydroxide as a titrant. Under optimized experimental conditions the analytical results of precision less than 1.8 and 2.5% (RSD) and of accuracy less than 3.0 and 5.4% (relative error (RE)) were obtained for MP-SL and SP-ML procedures, respectively, in ranges of 0.0031-0.0631 mol L(-1) for samples of hydrochloric acid and of 0.1680-1.7600 mol L(-1) for samples of acetic acid. The feasibility of both methods was illustrated by applying them to the total acidity determination in vinegar samples with precision lower than 0.5 and 2.9% (RSD) for MP-SL and SP-ML procedures, respectively.

Use of three-point taper systems in timber cruising

Treesearch

James W. Flewelling; Richard L. Ernst; Lawrence M. Raynes

2000-01-01

Tree volumes and profiles are often estimated as functions of total height and DBH. Alternative estimators include form-class methods, importance sampling, the centroid method, and multi-point profile (taper) estimation systems; all of these require some measurement or estimate of upper stem diameters. The multi-point profile system discussed here allows for upper stem...

Instructor Interaction and Immediacy Behaviors in a Multipoint Videoconferenced Instructional Environment: A Descriptive Case Study

ERIC Educational Resources Information Center

Bohnstedt, Kathy D.

2011-01-01

The purpose of this study was to examine the experiences of professors teaching in a multi-point videoconferencing instructional environment and how they interacted with students in proximate and remote classrooms. Qualitative and quantitative data were analyzed to gain an understanding of the teaching experience and to examine differences between…

Fluid sample collection and distribution system. [qualitative analysis of aqueous samples from several points

NASA Technical Reports Server (NTRS)

Brooks, R. L. (Inventor)

1979-01-01

A multipoint fluid sample collection and distribution system is provided wherein the sample inputs are made through one or more of a number of sampling valves to a progressive cavity pump which is not susceptible to damage by large unfiltered particles. The pump output is through a filter unit that can provide a filtered multipoint sample. An unfiltered multipoint sample is also provided. An effluent sample can be taken and applied to a second progressive cavity pump for pumping to a filter unit that can provide one or more filtered effluent samples. The second pump can also provide an unfiltered effluent sample. Means are provided to periodically back flush each filter unit without shutting off the whole system.

Single-Pulse Multi-Point Multi-Component Interferometric Rayleigh Scattering Velocimeter

NASA Technical Reports Server (NTRS)

Bivolaru, Daniel; Danehy, Paul M.; Lee, Joseph W.; Gaffney, Richard L., Jr.; Cutler, Andrew D.

2006-01-01

A simultaneous multi-point, multi-component velocimeter using interferometric detection of the Doppler shift of Rayleigh, Mie, and Rayleigh-Brillouin scattered light in supersonic flow is described. The system uses up to three sets of collection optics and one beam combiner for the reference laser light to form a single collimated beam. The planar Fabry-Perot interferometer used in the imaging mode for frequency detection preserves the spatial distribution of the signal reasonably well. Single-pulse multi-points measurements of up to two orthogonal and one non-orthogonal components of velocity in a Mach 2 free jet were performed to demonstrate the technique. The average velocity measurements show a close agreement with the CFD calculations using the VULCAN code.

Magnetosphere dynamics during the 14 November 2012 storm inferred from TWINS, AMPERE, Van Allen Probes, and BATS-R-US-CRCM

NASA Astrophysics Data System (ADS)

Buzulukova, Natalia; Goldstein, Jerry; Fok, Mei-Ching; Glocer, Alex; Valek, Phil; McComas, David; Korth, Haje; Anderson, Brian

2018-01-01

During the 14 November 2012 geomagnetic storm, the Van Allen Probes spacecraft observed a number of sharp decreases (dropouts) in particle fluxes for ions and electrons of different energies. In this paper, we investigate the global magnetosphere dynamics and magnetosphere-ionosphere (M-I) coupling during the dropout events using multipoint measurements by Van Allen Probes, TWINS, and AMPERE together with the output of the two-way coupled global BATS-R-US-CRCM model. We find different behavior for two pairs of dropouts. For one pair, the same pattern was repeated: (1) weak nightside Region 1 and 2 Birkeland currents before and during the dropout; (2) intensification of Region 2 currents after the dropout; and (3) a particle injection detected by TWINS after the dropout. The model predicted similar behavior of Birkeland currents. TWINS low-altitude emissions demonstrated high variability during these intervals, indicating high geomagnetic activity in the near-Earth tail region. For the second pair of dropouts, the structure of both Birkeland currents and ENA emissions was relatively stable. The model also showed quasi-stationary behavior of Birkeland currents and simulated ENA emissions with gradual ring current buildup. We confirm that the first pair of dropouts was caused by large-scale motions of the OCB (open-closed boundary) during substorm activity. We show the new result that this OCB motion was associated with global changes in Birkeland (M-I coupling) currents and strong modulation of low-altitude ion precipitation. The second pair of dropouts is the result of smaller OCB disturbances not related to magnetospheric substorms. The local observations of the first pair of dropouts result from a global magnetospheric reconfiguration, which is manifested by ion injections and enhanced ion precipitation detected by TWINS and changes in the structure of Birkeland currents detected by AMPERE. This study demonstrates that multipoint measurements along with the global model results enable the reconstruction of a more complete system-level picture of the dropout events and provides insight into M-I coupling aspects that have not previously been investigated.

Magnetosphere dynamics during the 14 November 2012 storm inferred from TWINS, AMPERE, Van Allen Probes, and BATS-R-US–CRCM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buzulukova, Natalia; Goldstein, Jerry; Fok, Mei-Ching

During the 14 November 2012 geomagnetic storm, the Van Allen Probes spacecraft observed a number of sharp decreases ("dropouts") in particle fluxes for ions and electrons of different energies. In this paper, we investigate the global magnetosphere dynamics and magnetosphere–ionosphere (M–I) coupling during the dropout events using multipoint measurements by Van Allen Probes, TWINS, and AMPERE together with the output of the two-way coupled global BATS-R-US–CRCM model. We find different behavior for two pairs of dropouts. For one pair, the same pattern was repeated: (1) weak nightside Region 1 and 2 Birkeland currents before and during the dropout; (2) intensificationmore » of Region 2 currents after the dropout; and (3) a particle injection detected by TWINS after the dropout. The model predicted similar behavior of Birkeland currents. TWINS low-altitude emissions demonstrated high variability during these intervals, indicating high geomagnetic activity in the near-Earth tail region. For the second pair of dropouts, the structure of both Birkeland currents and ENA emissions was relatively stable. The model also showed quasi-stationary behavior of Birkeland currents and simulated ENA emissions with gradual ring current buildup. We confirm that the first pair of dropouts was caused by large-scale motions of the OCB (open–closed boundary) during substorm activity. We show the new result that this OCB motion was associated with global changes in Birkeland (M–I coupling) currents and strong modulation of low-altitude ion precipitation. The second pair of dropouts is the result of smaller OCB disturbances not related to magnetospheric substorms. The local observations of the first pair of dropouts result from a global magnetospheric reconfiguration, which is manifested by ion injections and enhanced ion precipitation detected by TWINS and changes in the structure of Birkeland currents detected by AMPERE. This study demonstrates that multipoint measurements along with the global model results enable the reconstruction of a more complete system-level picture of the dropout events and provides insight into M–I coupling aspects that have not previously been investigated.« less

Magnetosphere Dynamics During the 14 November 2012 Storm Inferred from TWINS, AMPERE, Van Allen Probes, and BATS-R-US-CRCM

NASA Technical Reports Server (NTRS)

Buzulukova, Natalia; Goldstein, Jerry; Fok, Mei-Ching; Glocer, Alex; Valek, Phil; McComas, David; Korth, Haje; Anderson, Brian

2018-01-01

During the 14 November 2012 geomagnetic storm, the Van Allen Probes spacecraft observed a number of sharp decreases ('dropouts') in particle fluxes for ions and electrons of different energies. In this paper, we investigate the global magnetosphere dynamics and magnetosphere- ionosphere (M-I) coupling during the dropout events using multipoint measurements by Van Allen Probes, TWINS, and AMPERE together with the output of the two-way coupled global BATS-R-US-CRCM model. We find different behavior for two pairs of dropouts. For one pair, the same pattern was repeated: (1) weak nightside Region 1 and 2 Birkeland currents before and during the dropout; (2) intensification of Region 2 currents after the dropout; and (3) a particle injection detected by TWINS after the dropout. The model predicted similar behavior of Birkeland currents. TWINS low-altitude emissions demonstrated high variability during these intervals, indicating high geomagnetic activity in the near-Earth tail region. For the second pair of dropouts, the structure of both Birkeland currents and ENA emissions was relatively stable. The model also showed quasi-stationary behavior of Birkeland currents and simulated ENA emissions with gradual ring current buildup. We confirm that the first pair of dropouts was caused by large-scale motions of the OCB (open-closed boundary) during substorm activity. We show the new result that this OCB motion was associated with global changes in Birkeland (M-I coupling) currents and strong modulation of low-altitude ion precipitation. The second pair of dropouts is the result of smaller OCB disturbances not related to magnetospheric substorms. The local observations of the first pair of dropouts result from a global magnetospheric reconfiguration, which is manifested by ion injections and enhanced ion precipitation detected by TWINS and changes in the structure of Birkeland currents detected by AMPERE. This study demonstrates that multipoint measurements along with the global model results enable the reconstruction of a more complete system-level picture of the dropout events and provides insight into M-I coupling aspects that have not previously been investigated.

Magnetosphere dynamics during the 14 November 2012 storm inferred from TWINS, AMPERE, Van Allen Probes, and BATS-R-US–CRCM

DOE PAGES

Buzulukova, Natalia; Goldstein, Jerry; Fok, Mei-Ching; ...

2018-01-25

During the 14 November 2012 geomagnetic storm, the Van Allen Probes spacecraft observed a number of sharp decreases ("dropouts") in particle fluxes for ions and electrons of different energies. In this paper, we investigate the global magnetosphere dynamics and magnetosphere–ionosphere (M–I) coupling during the dropout events using multipoint measurements by Van Allen Probes, TWINS, and AMPERE together with the output of the two-way coupled global BATS-R-US–CRCM model. We find different behavior for two pairs of dropouts. For one pair, the same pattern was repeated: (1) weak nightside Region 1 and 2 Birkeland currents before and during the dropout; (2) intensificationmore » of Region 2 currents after the dropout; and (3) a particle injection detected by TWINS after the dropout. The model predicted similar behavior of Birkeland currents. TWINS low-altitude emissions demonstrated high variability during these intervals, indicating high geomagnetic activity in the near-Earth tail region. For the second pair of dropouts, the structure of both Birkeland currents and ENA emissions was relatively stable. The model also showed quasi-stationary behavior of Birkeland currents and simulated ENA emissions with gradual ring current buildup. We confirm that the first pair of dropouts was caused by large-scale motions of the OCB (open–closed boundary) during substorm activity. We show the new result that this OCB motion was associated with global changes in Birkeland (M–I coupling) currents and strong modulation of low-altitude ion precipitation. The second pair of dropouts is the result of smaller OCB disturbances not related to magnetospheric substorms. The local observations of the first pair of dropouts result from a global magnetospheric reconfiguration, which is manifested by ion injections and enhanced ion precipitation detected by TWINS and changes in the structure of Birkeland currents detected by AMPERE. This study demonstrates that multipoint measurements along with the global model results enable the reconstruction of a more complete system-level picture of the dropout events and provides insight into M–I coupling aspects that have not previously been investigated.« less

Human Modelling for Military Application (Applications militaires de la modelisation humaine)

DTIC Science & Technology

2010-10-01

techniques (rooted in the mathematics-centered analytic methods arising from World War I analyses by Lanchester 2 ). Recent requirements for research and...34Dry Shooting for Airplane Gunners - Popular Science Monthly". January 1919. p. 13-14. 2 Lanchester F.W., Mathematics in Warfare in The World of

Local network interconnection through a satellite point-to-multipoint link. Ph.D. Thesis - Ecole Nationale Superieure des Telecommunications, 6 Jul. 1985

NASA Technical Reports Server (NTRS)

Duarte, O. Muniz Bandeira

1986-01-01

Four architectures to implement a point to multipoint satellite link protocol for communication services offered by the Telecom 1 satellite network are presented. A safe communication service with error correction and flow control facilities is described. It is shown that a time transparent communication system combines simplicity and cost advantages.

Multipoint propagators in cosmological gravitational instability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernardeau, Francis; Crocce, Martin; Scoccimarro, Roman

2008-11-15

We introduce the concept of multipoint propagators between linear cosmic fields and their nonlinear counterparts in the context of cosmological perturbation theory. Such functions express how a nonlinearly evolved Fourier mode depends on the full ensemble of modes in the initial density field. We identify and resum the dominant diagrams in the large-k limit, showing explicitly that multipoint propagators decay into the nonlinear regime at the same rate as the two-point propagator. These analytic results generalize the large-k limit behavior of the two-point propagator to arbitrary order. We measure the three-point propagator as a function of triangle shape in numericalmore » simulations and confirm the results of our high-k resummation. We show that any n-point spectrum can be reconstructed from multipoint propagators, which leads to a physical connection between nonlinear corrections to the power spectrum at small scales and higher-order correlations at large scales. As a first application of these results, we calculate the reduced bispectrum at one loop in renormalized perturbation theory and show that we can predict the decrease in its dependence on triangle shape at redshift zero, when standard perturbation theory is least successful.« less

Use of near-infrared spectroscopy and multipoint measurements for quality control of pharmaceutical drug products.

PubMed

Boiret, Mathieu; Chauchard, Fabien

2017-01-01

Near-infrared (NIR) spectroscopy is a non-destructive analytical technique that enables better-understanding and optimization of pharmaceutical processes and final drug products. The use in line is often limited by acquisition speed and sampling area. This work focuses on performing a multipoint measurement at high acquisition speed at the end of the manufacturing process on a conveyor belt system to control both the distribution and the content of active pharmaceutical ingredient within final drug products, i.e., tablets. A specially designed probe with several collection fibers was developed for this study. By measuring spectral and spatial information, it provides physical and chemical knowledge on the final drug product. The NIR probe was installed on a conveyor belt system that enables the analysis of a lot of tablets. The use of these NIR multipoint measurement probes on a conveyor belt system provided an innovative method that has the potential to be used as a new paradigm to ensure the drug product quality at the end of the manufacturing process and as a new analytical method for the real-time release control strategy. Graphical abstract Use of near-infrared spectroscopy and multipoint measurements for quality control of pharmaceutical drug products.

Multipoint Ignition of a Gas Mixture by a Microwave Subcritical Discharge with an Extended Streamer Structure

NASA Astrophysics Data System (ADS)

Aleksandrov, K. V.; Busleev, N. I.; Grachev, L. P.; Esakov, I. I.; Ravaev, A. A.

2018-02-01

The results of experimental studies on using an electrical discharge with an extended streamer structure in a quasioptical microwave beam in the multipoint ignition of a propane-air mixture have been reported. The pulsed microwave discharge was initiated at the interior surface of a quartz tube that was filled with the mentioned flammable mixture and introduced into a microwave beam with a subbreakdown initial field. Gas breakdown was initiated by an electromagnetic vibrator. The dependence of the type of discharge on the microwave field strength was examined, the lower concentration threshold of ignition of the propane-air mixture by the studied discharge was determined, and the dynamics of combustion of the flammable mixture with local and multipoint ignition were compared.

Free-form Airfoil Shape Optimization Under Uncertainty Using Maximum Expected Value and Second-order Second-moment Strategies

NASA Technical Reports Server (NTRS)

Huyse, Luc; Bushnell, Dennis M. (Technical Monitor)

2001-01-01

Free-form shape optimization of airfoils poses unexpected difficulties. Practical experience has indicated that a deterministic optimization for discrete operating conditions can result in dramatically inferior performance when the actual operating conditions are different from the - somewhat arbitrary - design values used for the optimization. Extensions to multi-point optimization have proven unable to adequately remedy this problem of "localized optimization" near the sampled operating conditions. This paper presents an intrinsically statistical approach and demonstrates how the shortcomings of multi-point optimization with respect to "localized optimization" can be overcome. The practical examples also reveal how the relative likelihood of each of the operating conditions is automatically taken into consideration during the optimization process. This is a key advantage over the use of multipoint methods.

Integrated Sensing Using DNA Nanoarchitectures

DTIC Science & Technology

2014-05-20

Norton. Thiolated Dendrimers as Multi-Point Binding Headgroups for DNA Immobilization on Gold, Langmuir, (10 2011): 0. doi: 10.1021/la202444s...Figure 6, uses dendrimers to provide multipoint adhesion of a single stranded DNA component on a surface. Figure 6 Process for immobilizing... dendrimer (shown as a round species). These dendrimer species are Generation 3 PAMAM dendrimers with ~ 30 thiol groups to bind the dendrimer /DNA construct

Stability analysis of multipoint tool equipped with metal cutting ceramics

NASA Astrophysics Data System (ADS)

Maksarov, V. V.; Khalimonenko, A. D.; Matrenichev, K. G.

2017-10-01

The article highlights the issues of determining the stability of the cutting process by a multipoint cutting tool equipped with cutting ceramics. There were some recommendations offered on the choice of parameters of replaceable cutting ceramic plates for milling based of the conducted researches. Ceramic plates for milling are proposed to be selected on the basis of value of their electrical volume resistivity.

Warehouse multipoint temperature and humidity monitoring system design based on Kingview

NASA Astrophysics Data System (ADS)

Ou, Yanghui; Wang, Xifu; Liu, Jingyun

2017-04-01

Storage is the key link of modern logistics. Warehouse environment monitoring is an important part of storage safety management. To meet the storage requirements of different materials, guarantee their quality in the greatest extent, which has great significance. In the warehouse environment monitoring, the most important parameters are air temperature and relative humidity. In this paper, a design of warehouse multipoint temperature and humidity monitoring system based on King view, which realizes the multipoint temperature and humidity data real-time acquisition, monitoring and storage in warehouse by using temperature and humidity sensor. Also, this paper will take the bulk grain warehouse as an example and based on the data collected in real-time monitoring, giving the corresponding expert advice that combined with the corresponding algorithm, providing theoretical guidance to control the temperature and humidity in grain warehouse.

A Robust Distributed Multipoint Fiber Optic Gas Sensor System Based on AGC Amplifier Structure.

PubMed

Zhu, Cunguang; Wang, Rende; Tao, Xuechen; Wang, Guangwei; Wang, Pengpeng

2016-07-28

A harsh environment-oriented distributed multipoint fiber optic gas sensor system realized by automatic gain control (AGC) technology is proposed. To improve the photoelectric signal reliability, the electronic variable gain can be modified in real time by an AGC closed-loop feedback structure to compensate for optical transmission loss which is caused by the fiber bend loss or other reasons. The deviation of the system based on AGC structure is below 4.02% when photoelectric signal decays due to fiber bending loss for bending radius of 5 mm, which is 20 times lower than the ordinary differential system. In addition, the AGC circuit with the same electric parameters can keep the baseline intensity of signals in different channels of the distributed multipoint sensor system at the same level. This avoids repetitive calibrations and streamlines the installation process.

Public Data Set: Erratum: "Multi-point, high-speed passive ion velocity distribution diagnostic on the Pegasus Toroidal Experiment" [Rev. Sci. Instrum. 83, 10D516 (2012)

DOE Data Explorer

Burke, Marcus G. [University of Wisconsin-Madison] (ORCID:0000000176193724); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Schlossberg, David J. [University of Wisconsin-Madison] (ORCID:0000000287139448); Winz, Gregory R. [University of Wisconsin-Madison] (ORCID:0000000177627184)

2016-07-18

This data set contains openly-documented, machine readable digital research data corresponding to figures published in M.G. Burke et al., 'Erratum: "Multi-point, high-speed passive ion velocity distribution diagnostic on the Pegasus Toroidal Experiment" [Rev. Sci. Instrum. 83, 10D516 (2012)],' Rev. Sci. Instrum. 87, 079902 (2016).

Reliable Wireless Broadcast with Linear Network Coding for Multipoint-to-Multipoint Real-Time Communications

NASA Astrophysics Data System (ADS)

Kondo, Yoshihisa; Yomo, Hiroyuki; Yamaguchi, Shinji; Davis, Peter; Miura, Ryu; Obana, Sadao; Sampei, Seiichi

This paper proposes multipoint-to-multipoint (MPtoMP) real-time broadcast transmission using network coding for ad-hoc networks like video game networks. We aim to achieve highly reliable MPtoMP broadcasting using IEEE 802.11 media access control (MAC) that does not include a retransmission mechanism. When each node detects packets from the other nodes in a sequence, the correctly detected packets are network-encoded, and the encoded packet is broadcasted in the next sequence as a piggy-back for its native packet. To prevent increase of overhead in each packet due to piggy-back packet transmission, network coding vector for each node is exchanged between all nodes in the negotiation phase. Each user keeps using the same coding vector generated in the negotiation phase, and only coding information that represents which user signal is included in the network coding process is transmitted along with the piggy-back packet. Our simulation results show that the proposed method can provide higher reliability than other schemes using multi point relay (MPR) or redundant transmissions such as forward error correction (FEC). We also implement the proposed method in a wireless testbed, and show that the proposed method achieves high reliability in a real-world environment with a practical degree of complexity when installed on current wireless devices.

Site-specific multipoint fluorescence measurement system with end-capped optical fibers.

PubMed

Song, Woosub; Moon, Sucbei; Lee, Byoung-Cheol; Park, Chul-Seung; Kim, Dug Young; Kwon, Hyuk Sang

2011-07-10

We present the development and implementation of a spatially and spectrally resolved multipoint fluorescence correlation spectroscopy (FCS) system utilizing multiple end-capped optical fibers and an inexpensive laser source. Specially prepared end-capped optical fibers placed in an image plane were used to both collect fluorescence signals from the sample and to deliver signals to the detectors. The placement of independently selected optical fibers on the image plane was done by monitoring the end-capped fiber tips at the focus using a CCD, and fluorescence from specific positions of a sample were collected by an end-capped fiber, which could accurately represent light intensities or spectral data without incurring any disturbance. A fast multipoint spectroscopy system with a time resolution of ∼1.5 ms was then implemented using a prism and an electron multiplying charge coupled device with a pixel binning for the region of interest. The accuracy of our proposed system was subsequently confirmed by experimental results, based on an FCS analysis of microspheres in distilled water. We expect that the proposed multipoint site-specific fluorescence measurement system can be used as an inexpensive fluorescence measurement tool to study many intracellular and molecular dynamics in cell biology. © 2011 Optical Society of America

Team Modelling: Survey of Experimental Platforms (Modelisation d’equipes : Examen de plate-formes experimentales)

DTIC Science & Technology

2006-09-01

Control Force Agility Shared Situational Awareness Attentional Demand Interoperability Network Based Operations Effect Based Operations Speed of...Command Self Synchronization Reach Back Reach Forward Information Superiority Increased Mission Effectiveness Humansystems® Team Modelling...communication effectiveness and Distributed Mission Training (DMT) effectiveness . The NASA Ames Centre - Distributed Research Facilities platform could

Bellman Continuum (3rd) International Workshop (13-14 June 1988)

DTIC Science & Technology

1988-06-01

Modelling Uncertain Problem ................. 53 David Bensoussan ,---,>Asymptotic Linearization of Uncertain Multivariable Systems by Sliding Modes...K. Ghosh .-. Robust Model Tracking for a Class of Singularly Perturbed Nonlinear Systems via Composite Control ....... 93 F. Garofalo and L. Glielmo...MODELISATION ET COMMANDE EN ECONOMIE MODELS AND CONTROL POLICIES IN ECONOMICS Qualitative Differential Games : A Viability Approach ............. 117

A canonical state-space representation for SISO systems using multipoint Jordan CFE. [Continued-Fraction Expansion

NASA Technical Reports Server (NTRS)

Hwang, Chyi; Guo, Tong-Yi; Shieh, Leang-San

1991-01-01

A canonical state-space realization based on the multipoint Jordan continued-fraction expansion (CFE) is presented for single-input-single-output (SISO) systems. The similarity transformation matrix which relates the new canonical form to the phase-variable canonical form is also derived. The presented canonical state-space representation is particularly attractive for the application of SISO system theory in which a reduced-dimensional time-domain model is necessary.

Free choice access to multipoint wellness education and related services positively impacts employee wellness: a randomized and controlled trial.

PubMed

Sforzo, Gary A; Kaye, Miranda P; Calleri, David; Ngai, Nancy

2012-04-01

Examine effects of voluntary participation in employer-sponsored, multipoint wellness education programming on employee wellness. A randomized and controlled design was used to organize 96 participants into an education + access group; an access-only group, and control group. Outcome measures were made at start and end of a 12-week intervention period. Education + access improved wellness knowledge, which, in turn, enhanced life satisfaction, employee morale, and energy, and nearly improved stress level. Those who received facility access without educational programming did not reap health benefits. Employees voluntarily used the fitness facility and healthy meal cards only 1.3 and 1.5 times per week, respectively. Participants made limited and likely inadequate use of wellness opportunities. As a result, physical health benefits (eg, blood pressure, fitness parameters) were not seen in the present study. However, multipoint wellness education resulted in psychosocial health benefits in 12 weeks.

Remote Sensing of the Reconnection Electric Field From In Situ Multipoint Observations of the Separatrix Boundary

NASA Astrophysics Data System (ADS)

Nakamura, T. K. M.; Nakamura, R.; Varsani, A.; Genestreti, K. J.; Baumjohann, W.; Liu, Y.-H.

2018-05-01

A remote sensing technique to infer the local reconnection electric field based on in situ multipoint spacecraft observation at the reconnection separatrix is proposed. In this technique, the increment of the reconnected magnetic flux is estimated by integrating the in-plane magnetic field during the sequential observation of the separatrix boundary by multipoint measurements. We tested this technique by applying it to virtual observations in a two-dimensional fully kinetic particle-in-cell simulation of magnetic reconnection without a guide field and confirmed that the estimated reconnection electric field indeed agrees well with the exact value computed at the X-line. We then applied this technique to an event observed by the Magnetospheric Multiscale mission when crossing an energetic plasma sheet boundary layer during an intense substorm. The estimated reconnection electric field for this event is nearly 1 order of magnitude higher than a typical value of magnetotail reconnection.

Understanding Turbulence using Active and Passive Multipoint Measurements in Laboratory Magnetospheres

NASA Astrophysics Data System (ADS)

Mauel, M. E.; Abler, M. C.; Qian, T. M.; Saperstein, A.; Yan, J. R.

2017-10-01

In a laboratory magnetosphere, plasma is confined by a strong dipole magnet, and interchange and entropy mode turbulence can be studied and controlled in near steady-state conditions. Turbulence is dominated by long wavelength modes exhibiting chaotic dynamics, intermitency, and an inverse spectral cascade. Here, we summarize recent results: (i) high-resolution measurement of the frequency-wavenumber power spectrum using Capon's ``maximum likelihood method'', and (ii) direct measurement of the nonlinear coupling of interchange/entropy modes in a turbulent plasma through driven current injection at multiple locations and frequencies. These observations well-characterize plasma turbulence over a broad band of wavelengths and frequencies. Finally, we also discuss the application of these techniques to space-based experiments and observations aimed to reveal the nature of heliospheric and magnetospheric plasma turbulence. Supported by NSF-DOE Partnership in Plasma Science Grant DE-FG02-00ER54585.

Modal demultiplexing properties of tapered and nanostructured optical fibers for in vivo optogenetic control of neural activity.

PubMed

Pisanello, Marco; Della Patria, Andrea; Sileo, Leonardo; Sabatini, Bernardo L; De Vittorio, Massimo; Pisanello, Ferruccio

2015-10-01

Optogenetic approaches to manipulate neural activity have revolutionized the ability of neuroscientists to uncover the functional connectivity underlying brain function. At the same time, the increasing complexity of in vivo optogenetic experiments has increased the demand for new techniques to precisely deliver light into the brain, in particular to illuminate selected portions of the neural tissue. Tapered and nanopatterned gold-coated optical fibers were recently proposed as minimally invasive multipoint light delivery devices, allowing for site-selective optogenetic stimulation in the mammalian brain [Pisanello , Neuron82, 1245 (2014)]. Here we demonstrate that the working principle behind these devices is based on the mode-selective photonic properties of the fiber taper. Using analytical and ray tracing models we model the finite conductance of the metal coating, and show that single or multiple optical windows located at specific taper sections can outcouple only specific subsets of guided modes injected into the fiber.

STE/ICE (Simplified Test Equipment/Internal Combustion Engines) Design Guide for Vehicle Diagnostic Connector Assemblies

DTIC Science & Technology

1982-08-01

19 3.2 Diesel Engine Speed Transducer 20 3.3 Pressure Transducer 20 3.4 Temperature Transducer 22 3.5 Differential Pressure Switch 22 3.6 Differential... Pressure Switch , Multi-Point 22 3.7 Current Measurement Transducer 23 - 3.8 Electrolyte Level Probes 23 3.9 Diagnostic Connector 24 3.10 Harness...12258933 Differential Pressure Switch - Multi-point 12258934 K -. Differential Pressure Switch 12258938 Electrolyte Level Sensor 12258935 Shunt 1000

Multipoint propagators for non-Gaussian initial conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernardeau, Francis; Sefusatti, Emiliano; Crocce, Martin

2010-10-15

We show here how renormalized perturbation theory calculations applied to the quasilinear growth of the large-scale structure can be carried on in presence of primordial non-Gaussian (PNG) initial conditions. It is explicitly demonstrated that the series reordering scheme proposed in Bernardeau, Crocce, and Scoccimarro [Phys. Rev. D 78, 103521 (2008)] is preserved for non-Gaussian initial conditions. This scheme applies to the power spectrum and higher-order spectra and is based on a reorganization of the contributing terms into the sum of products of multipoint propagators. In case of PNG, new contributing terms appear, the importance of which is discussed in themore » context of current PNG models. The properties of the building blocks of such resummation schemes, the multipoint propagators, are then investigated. It is first remarked that their expressions are left unchanged at one-loop order irrespective of statistical properties of the initial field. We furthermore show that the high-momentum limit of each of these propagators can be explicitly computed even for arbitrary initial conditions. They are found to be damped by an exponential cutoff whose expression is directly related to the moment generating function of the one-dimensional displacement field. This extends what had been established for multipoint propagators for Gaussian initial conditions. Numerical forms of the cutoff are shown for the so-called local model of PNG.« less

Traceability of pH measurements by glass electrode cells: performance characteristic of pH electrodes by multi-point calibration.

PubMed

Naumann, R; Alexander-Weber, Ch; Eberhardt, R; Giera, J; Spitzer, P

2002-11-01

Routine pH measurements are carried out with pH meter-glass electrode assemblies. In most cases the glass and reference electrodes are thereby fashioned into a single probe, the so-called 'combination electrode' or simply 'the pH electrode'. The use of these electrodes is subject to various effects, described below, producing uncertainties of unknown magnitude. Therefore, the measurement of pH of a sample requires a suitable calibration by certified standard buffer solutions (CRMs) traceable to primary pH standards. The procedures in use are based on calibrations at one point, at two points bracketing the sample pH and at a series of points, the so-called multi-point calibration. The multi-point calibration (MPC) is recommended if minimum uncertainty and maximum consistency are required over a wide range of unknown pH values. Details of uncertainty computations for the two-point and MPC procedure are given. Furthermore, the multi-point calibration is a useful tool to characterise the performance of pH electrodes. This is demonstrated with different commercial pH electrodes. ELECTRONIC SUPPLEMENTARY MATERIAL is available if you access this article at http://dx.doi.org/10.1007/s00216-002-1506-5. On that page (frame on the left side), a link takes you directly to the supplementary material.

Environmental Modeling Packages for the MSTDCL TDP: Review and Recommendations (Trousses de Modelisation Environnementale Pour le PDT DCLTCM: Revue et Recommendations)

DTIC Science & Technology

2009-09-01

frequency shallow water scenarios, and DRDC has ready access to a well-established PE model ( PECan ). In those spectral areas below 1 kHz, where the PE...PCs Personnel Computers PE Parabolic Equation PECan PE Model developed by DRDC SPADES/ICE Sensor Performance and Acoustic Detection Evaluation

The network and transmission of based on the principle of laser multipoint communication

NASA Astrophysics Data System (ADS)

Fu, Qiang; Liu, Xianzhu; Jiang, Huilin; Hu, Yuan; Jiang, Lun

2014-11-01

Space laser communication is the perfectly choose to the earth integrated information backbone network in the future. This paper introduces the structure of the earth integrated information network that is a large capacity integrated high-speed broadband information network, a variety of communications platforms were densely interconnected together, such as the land, sea, air and deep air users or aircraft, the technologies of the intelligent high-speed processing, switching and routing were adopt. According to the principle of maximum effective comprehensive utilization of information resources, get accurately information, fast processing and efficient transmission through inter-satellite, satellite earth, sky and ground station and other links. Namely it will be a space-based, air-based and ground-based integrated information network. It will be started from the trends of laser communication. The current situation of laser multi-point communications were expounded, the transmission scheme of the dynamic multi-point between wireless laser communication n network has been carefully studied, a variety of laser communication network transmission schemes the corresponding characteristics and scope described in detail , described the optical multiplexer machine that based on the multiport form of communication is applied to relay backbone link; the optical multiplexer-based on the form of the segmentation receiver field of view is applied to small angle link, the optical multiplexer-based form of three concentric spheres structure is applied to short distances, motorized occasions, and the multi-point stitching structure based on the rotation paraboloid is applied to inter-satellite communications in detail. The multi-point laser communication terminal apparatus consist of the transmitting and receiving antenna, a relay optical system, the spectroscopic system, communication system and communication receiver transmitter system. The communication forms of optical multiplexer more than four goals or more, the ratio of received power and volume weight will be Obvious advantages, and can track multiple moving targets in flexible.It would to provide reference for the construction of earth integrated information networks.

Scalar discrete nonlinear multipoint boundary value problems

NASA Astrophysics Data System (ADS)

Rodriguez, Jesus; Taylor, Padraic

2007-06-01

In this paper we provide sufficient conditions for the existence of solutions to scalar discrete nonlinear multipoint boundary value problems. By allowing more general boundary conditions and by imposing less restrictions on the nonlinearities, we obtain results that extend previous work in the area of discrete boundary value problems [Debra L. Etheridge, Jesus Rodriguez, Periodic solutions of nonlinear discrete-time systems, Appl. Anal. 62 (1996) 119-137; Debra L. Etheridge, Jesus Rodriguez, Scalar discrete nonlinear two-point boundary value problems, J. Difference Equ. Appl. 4 (1998) 127-144].

Recent Results from NASA's Morphing Project

NASA Technical Reports Server (NTRS)

McGowan, Anna-Maria R.; Washburn, Anthony E.; Horta, Lucas G.; Bryant, Robert G.; Cox, David E.; Siochi, Emilie J.; Padula, Sharon L.; Holloway, Nancy M.

2002-01-01

The NASA Morphing Project seeks to develop and assess advanced technologies and integrated component concepts to enable efficient, multi-point adaptability in air and space vehicles. In the context of the project, the word "morphing" is defined as "efficient, multi-point adaptability" and may include macro, micro, structural and/or fluidic approaches. The project includes research on smart materials, adaptive structures, micro flow control, biomimetic concepts, optimization and controls. This paper presents an updated overview of the content of the Morphing Project including highlights of recent research results.

[Linkage analysis of susceptibility loci in 2 target chromosomes in pedigrees with paranoid schizophrenia and undifferentiated schizophrenia].

PubMed

Zeng, Li-ping; Hu, Zheng-mao; Mu, Li-li; Mei, Gui-sen; Lu, Xiu-ling; Zheng, Yong-jun; Li, Pei-jian; Zhang, Ying-xue; Pan, Qian; Long, Zhi-gao; Dai, He-ping; Zhang, Zhuo-hua; Xia, Jia-hui; Zhao, Jing-ping; Xia, Kun

2011-06-01

To investigate the relationship of susceptibility loci in chromosomes 1q21-25 and 6p21-25 and schizophrenia subtypes in Chinese population. A genomic scan and parametric and non-parametric analyses were performed on 242 individuals from 36 schizophrenia pedigrees, including 19 paranoid schizophrenia and 17 undifferentiated schizophrenia pedigrees, from Henan province of China using 5 microsatellite markers in the chromosome region 1q21-25 and 8 microsatellite markers in the chromosome region 6p21-25, which were the candidates of previous studies. All affected subjects were diagnosed and typed according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revised (DSM-IV-TR; American Psychiatric Association, 2000). All subjects signed informed consent. In chromosome 1, parametric analysis under the dominant inheritance mode of all 36 pedigrees showed that the maximum multi-point heterogeneity Log of odds score method (HLOD) score was 1.33 (α = 0.38). The non-parametric analysis and the single point and multi-point nonparametric linkage (NPL) scores suggested linkage at D1S484, D1S2878, and D1S196. In the 19 paranoid schizophrenias pedigrees, linkage was not observed for any of the 5 markers. In the 17 undifferentiated schizophrenia pedigrees, the multi-point NPL score was 1.60 (P= 0.0367) at D1S484. The single point NPL score was 1.95(P= 0.0145) and the multi-point NPL score was 2.39 (P= 0.0041) at D1S2878. Additionally, the multi-point NPL score was 1.74 (P= 0.0255) at D1S196. These same three loci showed suggestive linkage during the integrative analysis of all 36 pedigrees. In chromosome 6, parametric linkage analysis under the dominant and recessive inheritance and the non-parametric linkage analysis of all 36 pedigrees and the 17 undifferentiated schizophrenia pedigrees, linkage was not observed for any of the 8 markers. In the 19 paranoid schizophrenias pedigrees, parametric analysis showed that under recessive inheritance mode the maximum single-point HLOD score was 1.26 (α = 0.40) and the multi-point HLOD was 1.12 (α = 0.38) at D6S289 in the chromosome 6p23. In nonparametric analysis, the single-point NPL score was 1.52 (P= 0.0402) and the multi-point NPL score was 1.92 (P= 0.0206) at D6S289. Susceptibility genes correlated with undifferentiated schizophrenia pedigrees from D1S484, D1S2878, D1S196 loci, and those correlated with paranoid schizophrenia pedigrees from D6S289 locus are likely present in chromosome regions 1q23.3 and 1q24.2, and chromosome region 6p23, respectively.

Investigation of air-assisted sprays submitted to high frequency transverse acoustic fields: Droplet clustering

NASA Astrophysics Data System (ADS)

Ficuciello, A.; Blaisot, J. B.; Richard, C.; Baillot, F.

2017-06-01

An experimental investigation of the effects of a high amplitude transverse acoustic field on coaxial jets is presented in this paper. Water and air are used as working fluids at ambient pressure. The coaxial injectors are placed on the top of a semi-open resonant cavity where the acoustic pressure fluctuations of the standing wave can reach a maximum peak-to-peak amplitude of 12 kPa at the forcing frequency of 1 kHz. Several test conditions are considered in order to quantify the influence of injection conditions, acoustic field amplitude, and injector position with respect to the standing wave acoustic field. A high speed back-light visualization technique is used to characterize the jet response. Image processing is used to obtain valuable information about the jet behavior. It is shown that the acoustic field drastically affects the atomization process for all atomization regimes. The position of the injector in the acoustic field determines the jet response, and a droplet-clustering phenomenon is highlighted in multi-point injection conditions and quantified by determining discrete droplet location distributions. A theoretical model based on nonlinear acoustics related to the spatial distribution of the radiation pressure exerted on an object explains the behavior observed.

Extraction of repetitive transients with frequency domain multipoint kurtosis for bearing fault diagnosis

NASA Astrophysics Data System (ADS)

Liao, Yuhe; Sun, Peng; Wang, Baoxiang; Qu, Lei

2018-05-01

The appearance of repetitive transients in a vibration signal is one typical feature of faulty rolling element bearings. However, accurate extraction of these fault-related characteristic components has always been a challenging task, especially when there is interference from large amplitude impulsive noises. A frequency domain multipoint kurtosis (FDMK)-based fault diagnosis method is proposed in this paper. The multipoint kurtosis is redefined in the frequency domain and the computational accuracy is improved. An envelope autocorrelation function is also presented to estimate the fault characteristic frequency, which is used to set the frequency hunting zone of the FDMK. Then, the FDMK, instead of kurtosis, is utilized to generate a fast kurtogram and only the optimal band with maximum FDMK value is selected for envelope analysis. Negative interference from both large amplitude impulsive noise and shaft rotational speed related harmonic components are therefore greatly reduced. The analysis results of simulation and experimental data verify the capability and feasibility of this FDMK-based method

Numerical Solution of Systems of Loaded Ordinary Differential Equations with Multipoint Conditions

NASA Astrophysics Data System (ADS)

Assanova, A. T.; Imanchiyev, A. E.; Kadirbayeva, Zh. M.

2018-04-01

A system of loaded ordinary differential equations with multipoint conditions is considered. The problem under study is reduced to an equivalent boundary value problem for a system of ordinary differential equations with parameters. A system of linear algebraic equations for the parameters is constructed using the matrices of the loaded terms and the multipoint condition. The conditions for the unique solvability and well-posedness of the original problem are established in terms of the matrix made up of the coefficients of the system of linear algebraic equations. The coefficients and the righthand side of the constructed system are determined by solving Cauchy problems for linear ordinary differential equations. The solutions of the system are found in terms of the values of the desired function at the initial points of subintervals. The parametrization method is numerically implemented using the fourth-order accurate Runge-Kutta method as applied to the Cauchy problems for ordinary differential equations. The performance of the constructed numerical algorithms is illustrated by examples.

In-line multipoint near-infrared spectroscopy for moisture content quantification during freeze-drying.

PubMed

Kauppinen, Ari; Toiviainen, Maunu; Korhonen, Ossi; Aaltonen, Jaakko; Järvinen, Kristiina; Paaso, Janne; Juuti, Mikko; Ketolainen, Jarkko

2013-02-19

During the past decade, near-infrared (NIR) spectroscopy has been applied for in-line moisture content quantification during a freeze-drying process. However, NIR has been used as a single-vial technique and thus is not representative of the entire batch. This has been considered as one of the main barriers for NIR spectroscopy becoming widely used in process analytical technology (PAT) for freeze-drying. Clearly it would be essential to monitor samples that reliably represent the whole batch. The present study evaluated multipoint NIR spectroscopy for in-line moisture content quantification during a freeze-drying process. Aqueous sucrose solutions were used as model formulations. NIR data was calibrated to predict the moisture content using partial least-squares (PLS) regression with Karl Fischer titration being used as a reference method. PLS calibrations resulted in root-mean-square error of prediction (RMSEP) values lower than 0.13%. Three noncontact, diffuse reflectance NIR probe heads were positioned on the freeze-dryer shelf to measure the moisture content in a noninvasive manner, through the side of the glass vials. The results showed that the detection of unequal sublimation rates within a freeze-dryer shelf was possible with the multipoint NIR system in use. Furthermore, in-line moisture content quantification was reliable especially toward the end of the process. These findings indicate that the use of multipoint NIR spectroscopy can achieve representative quantification of moisture content and hence a drying end point determination to a desired residual moisture level.

Multipoint Green's functions in 1 + 1 dimensional integrable quantum field theories

DOE PAGES

Babujian, H. M.; Karowski, M.; Tsvelik, A. M.

2017-02-14

We calculate the multipoint Green functions in 1+1 dimensional integrable quantum field theories. We use the crossing formula for general models and calculate the 3 and 4 point functions taking in to account only the lower nontrivial intermediate states contributions. Then we apply the general results to the examples of the scaling Z 2 Ising model, sinh-Gordon model and Z 3 scaling Potts model. We demonstrate this calculations explicitly. The results can be applied to physical phenomena as for example to the Raman scattering.

Satellite economics in the 1980's

NASA Astrophysics Data System (ADS)

Morgan, W. L.

1980-01-01

Satellite traffic, competition, and decreasing costs are discussed, as are capabilities in telecommunication (including entertainment) and computation. Also considered are future teleconferencing and telecommuting to offset the cost of transportation, the establishment of a manufacturer-to-user link for increased home minicomputer capability, and an increase of digital over analog traffic. It is suggested that transcontinental bulk traffic, high-speed data, and multipoint private networks will eventually be handled by satellites which are cost-insensitive to distance, readily match dynamically varying multipoint networks, and have uniformly wide bandwidths available to both major cities and isolated towns.

Initial Thomson Scattering Survey of Local Helicity Injection and Ohmic Plasmas at the Pegasus Toroidal Experiment

NASA Astrophysics Data System (ADS)

Schlossberg, D. J.; Bodner, G. M.; Bongard, M. W.; Fonck, R. J.; Winz, G. R.

2014-10-01

A multipoint Thomson scattering diagnostic has recently been installed on the Pegasus ST. The system utilizes a frequency-doubled Nd:YAG laser (λ0 ~ 532 nm), spectrometers with volume phase holographic gratings, and a gated, intensified CCD camera. It provides measurements of Te and ne at 8 spatial locations for each spectrometer once per discharge. A new multiple aperture and beam dump system has been implemented to mitigate interference from stray light. This system has provided initial measurements in the core region of plasmas initiated by local helicity injection (LHI), as well as conventional Ohmic L- and H-mode discharges. Multi-shot averages of low-density (ne ~ 3 ×1018 m-3) , Ip ~ 0 . 1 MA LHI discharges show central Te ~ 75 eV at the end of the helicity injection phase. Ip ~ 0 . 13 MA Ohmic plasmas at moderate densities (ne ~ 2 ×1019 m-3) have core Te ~ 150 eV in L-mode. Generally, these plasmas do not reach transport equilibrium in the short 25 ms pulse length available. After an L-H transition, strong spectral broadening indicates increasing Te, to values above the range of the present spectrometer system with a high-dispersion VPH grating. Near-term system upgrades will focus on deploying a second spectrometer, with a lower-dispersion grating capable of measuring the 0.1-1.0 keV range. The second spectrometer system will also increase the available number of spatial channels, enabling study of H-mode pedestal structure. Work supported by US DOE Grant DE-FG02-96ER54375.

A Designer’s Guide to Human Performance Modelling (La Modelisation des Performances Humaines: Manuel du Concepteur).

DTIC Science & Technology

1998-12-01

failure detection, monitoring, and decision making.) moderator function. Originally, the output from these One of the best known OCM implementations, the...imposed by the tasks themselves, the information and equipment provided, the task environment, operator skills and experience, operator strategies , the...problem-solving situation, including the toward failure.) knowledge necessary to generate the right problem- solving strategies , the attention that

Initial results from a multi-point mapping observation of thundercloud high-energy radiation in coastal area of Japan sea

NASA Astrophysics Data System (ADS)

Wada, Y.; Enoto, T.; Furuta, Y.; Nakazawa, K.; Yuasa, T.; Okuda, K.; Makishima, K.; Nakano, T.; Umemoto, D.; Tsuchiya, H.

2017-12-01

On-ground detections of Thunderstorm Radiation Bursts (TRB) which mainly consist of bremsstrahlung gamma rays with energy extending up to 20 MeV indicate powerful electron accelerations inside thunderclouds or along lightning discharge paths (e.g. Torii et al., 2002, Tsuchiya et al., 2007, Dwyer et al., 2004). In order to resolve time variation and structure of the electron accelerators, we have constructed a multi-point mapping observation network with the aim of tracing gamma rays from moving thunderclouds since 2015. In fiscal 2016, we developed low cost and small size detectors dedicated to our observation. The data acquisition system records energy and timing of individual gamma-ray photons by 4-ch and 50 MHz sampling electrical boards (9.5 cm x 9.5 cm), coupled with BGO scintillator crystals. The systems were installed in portable water-proof boxes. We operated 10 detectors in two areas (Ishikawa and Niigata) along the coast of Japan Sea from October 2016 to April 2017. During this period, detectors in Ishikawa detected in total 10 TRBs lasting for several minutes associated with passage of a thundercloud. Our previous single-site measurement at Niigata, has recorded 1.4 TRBs per year on average in 2006-2015. Therefore, our new multi-point observation detected 7 times as many events as the previous system. One of the TRB gamma-ray spectra was fitted well by a cutoff power-law model. We performed a Monte Carlo simulation, and revealed that this spectrum was explained as bremsstrahlung of a monochromatic 15 MeV electron beam generated at an altitude of 500 m. We also succeeded in tracing gamma rays from an identical moving thundercloud with two detectors, demonstrating performance of the multi-point observation. In addition, we detected "short TRBs" lasting for a few hundred milliseconds associated with lightning discharges from four independent detectors placed 500 m apart simultaneously, in January and February 2017 at Niigata. The results in 2016-2017 winter season are proving that our multi-point observation can firmly detect a large number of TRBs and trace gamma rays from thunderstorms.

Computational approach to estimating the effects of blood properties on changes in intra-stent flow.

PubMed

Benard, Nicolas; Perrault, Robert; Coisne, Damien

2006-08-01

In this study various blood rheological assumptions are numerically investigated for the hemodynamic properties of intra-stent flow. Non-newtonian blood properties have never been implemented in blood coronary stented flow investigation, although its effects appear essential for a correct estimation and distribution of wall shear stress (WSS) exerted by the fluid on the internal vessel surface. Our numerical model is based on a full 3D stent mesh. Rigid wall and stationary inflow conditions are applied. Newtonian behavior, non-newtonian model based on Carreau-Yasuda relation and a characteristic newtonian value defined with flow representative parameters are introduced in this research. Non-newtonian flow generates an alteration of near wall viscosity norms compared to newtonian. Maximal WSS values are located in the center part of stent pattern structure and minimal values are focused on the proximal stent wire surface. A flow rate increase emphasizes fluid perturbations, and generates a WSS rise except for interstrut area. Nevertheless, a local quantitative analysis discloses an underestimation of WSS for modelisation using a newtonian blood flow, with clinical consequence of overestimate restenosis risk area. Characteristic viscosity introduction appears to present a useful option compared to rheological modelisation based on experimental data, with computer time gain and relevant results for quantitative and qualitative WSS determination.

Comparison of clinical outcomes of multi-point umbrella suturing and single purse suturing with two-point traction after procedure for prolapse and hemorrhoids (PPH) surgery.

PubMed

Jiang, Huiyong; Hao, Xiuyan; Xin, Ying; Pan, Youzhen

2017-11-01

To compare the clinical outcomes of multipoint umbrella suture and single-purse suture with two-point traction after procedure for prolapse and hemorrhoids surgery (PPH) for the treatment of mixed hemorrhoids. Ninety patients were randomly divided into a PPH plus single-purse suture group (Group A) and a PPH plus multipoint umbrella suture (Group B). All operations were performed by an experienced surgeon. Operation time, width of the specimen, hemorrhoids retraction extent, postoperative pain, postoperative bleeding, and length of hospitalization were recorded and compared. Statistical analysis was conducted by t-test and χ2 test. There were no significant differences in sex, age, course of disease, and degree of prolapse of hemorrhoids between the two groups. The operative time in Group A was significantly shorter than that in Group B (P < 0.05). However, the incidence rates of submucosal hematoma and incomplete hemorrhoid core retraction were significantly lower in Group B (P < 0.05), whereas the width of the specimens in Group B was greater than that in Group A (P < 0.05). There were fewer redundant skin tags in Group B at three months follow-up. No significant difference in postoperative pain, postoperative bleeding, and time of hospital stay (P > 0.05 for all comparisons) was observed. The multipoint umbrella suture showed better clinical outcomes because of its targeted suture according to the extent of hemorrhoid prolapse. Copyright © 2017. Published by Elsevier Ltd.

Rapid and accurate peripheral nerve detection using multipoint Raman imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kumamoto, Yasuaki; Minamikawa, Takeo; Kawamura, Akinori; Matsumura, Junichi; Tsuda, Yuichiro; Ukon, Juichiro; Harada, Yoshinori; Tanaka, Hideo; Takamatsu, Tetsuro

2017-02-01

Nerve-sparing surgery is essential to avoid functional deficits of the limbs and organs. Raman scattering, a label-free, minimally invasive, and accurate modality, is one of the best candidate technologies to detect nerves for nerve-sparing surgery. However, Raman scattering imaging is too time-consuming to be employed in surgery. Here we present a rapid and accurate nerve visualization method using a multipoint Raman imaging technique that has enabled simultaneous spectra measurement from different locations (n=32) of a sample. Five sec is sufficient for measuring n=32 spectra with good S/N from a given tissue. Principal component regression discriminant analysis discriminated spectra obtained from peripheral nerves (n=863 from n=161 myelinated nerves) and connective tissue (n=828 from n=121 tendons) with sensitivity and specificity of 88.3% and 94.8%, respectively. To compensate the spatial information of a multipoint-Raman-derived tissue discrimination image that is too sparse to visualize nerve arrangement, we used morphological information obtained from a bright-field image. When merged with the sparse tissue discrimination image, a morphological image of a sample shows what portion of Raman measurement points in arbitrary structure is determined as nerve. Setting a nerve detection criterion on the portion of "nerve" points in the structure as 40% or more, myelinated nerves (n=161) and tendons (n=121) were discriminated with sensitivity and specificity of 97.5%. The presented technique utilizing a sparse multipoint Raman image and a bright-field image has enabled rapid, safe, and accurate detection of peripheral nerves.

Multi-point objective-oriented sequential sampling strategy for constrained robust design

NASA Astrophysics Data System (ADS)

Zhu, Ping; Zhang, Siliang; Chen, Wei

2015-03-01

Metamodelling techniques are widely used to approximate system responses of expensive simulation models. In association with the use of metamodels, objective-oriented sequential sampling methods have been demonstrated to be effective in balancing the need for searching an optimal solution versus reducing the metamodelling uncertainty. However, existing infilling criteria are developed for deterministic problems and restricted to one sampling point in one iteration. To exploit the use of multiple samples and identify the true robust solution in fewer iterations, a multi-point objective-oriented sequential sampling strategy is proposed for constrained robust design problems. In this article, earlier development of objective-oriented sequential sampling strategy for unconstrained robust design is first extended to constrained problems. Next, a double-loop multi-point sequential sampling strategy is developed. The proposed methods are validated using two mathematical examples followed by a highly nonlinear automotive crashworthiness design example. The results show that the proposed method can mitigate the effect of both metamodelling uncertainty and design uncertainty, and identify the robust design solution more efficiently than the single-point sequential sampling approach.

Capturing rogue waves by multi-point statistics

NASA Astrophysics Data System (ADS)

Hadjihosseini, A.; Wächter, Matthias; Hoffmann, N. P.; Peinke, J.

2016-01-01

As an example of a complex system with extreme events, we investigate ocean wave states exhibiting rogue waves. We present a statistical method of data analysis based on multi-point statistics which for the first time allows the grasping of extreme rogue wave events in a highly satisfactory statistical manner. The key to the success of the approach is mapping the complexity of multi-point data onto the statistics of hierarchically ordered height increments for different time scales, for which we can show that a stochastic cascade process with Markov properties is governed by a Fokker-Planck equation. Conditional probabilities as well as the Fokker-Planck equation itself can be estimated directly from the available observational data. With this stochastic description surrogate data sets can in turn be generated, which makes it possible to work out arbitrary statistical features of the complex sea state in general, and extreme rogue wave events in particular. The results also open up new perspectives for forecasting the occurrence probability of extreme rogue wave events, and even for forecasting the occurrence of individual rogue waves based on precursory dynamics.

Multipoint molecular recognition within a calix[6]arene funnel complex

PubMed Central

Coquière, David; de la Lande, Aurélien; Martí, Sergio; Parisel, Olivier; Prangé, Thierry; Reinaud, Olivia

2009-01-01

A multipoint recognition system based on a calix[6]arene is described. The calixarene core is decorated on alternating aromatic subunits by 3 imidazole arms at the small rim and 3 aniline groups at the large rim. This substitution pattern projects the aniline nitrogens toward each other when Zn(II) binds at the Tris-imidazole site or when a proton binds at an aniline. The XRD structure of the monoprotonated complex having an acetonitrile molecule bound to Zn(II) in the cavity revealed a constrained geometry at the metal center reminiscent of an entatic state. Computer modeling suggests that the aniline groups behave as a tritopic monobasic site in which only 1 aniline unit is protonated and interacts with the other 2 through strong hydrogen bonding. The metal complex selectively binds a monoprotonated diamine vs. a monoamine through multipoint recognition: coordination to the metal ion at the small rim, hydrogen bonding to the calix-oxygen core, CH/π interaction within the cavity's aromatic walls, and H-bonding to the anilines at the large rim. PMID:19237564

Multi-point estimation of total energy expenditure: a comparison between zinc-reduction and platinum-equilibration methodologies.

PubMed

Sonko, Bakary J; Miller, Leland V; Jones, Richard H; Donnelly, Joseph E; Jacobsen, Dennis J; Hill, James O; Fennessey, Paul V

2003-12-15

Reducing water to hydrogen gas by zinc or uranium metal for determining D/H ratio is both tedious and time consuming. This has forced most energy metabolism investigators to use the "two-point" technique instead of the "Multi-point" technique for estimating total energy expenditure (TEE). Recently, we purchased a new platinum (Pt)-equilibration system that significantly reduces both time and labor required for D/H ratio determination. In this study, we compared TEE obtained from nine overweight but healthy subjects, estimated using the traditional Zn-reduction method to that obtained from the new Pt-equilibration system. Rate constants, pool spaces, and CO2 production rates obtained from use of the two methodologies were not significantly different. Correlation analysis demonstrated that TEEs estimated using the two methods were significantly correlated (r=0.925, p=0.0001). Sample equilibration time was reduced by 66% compared to those of similar methods. The data demonstrated that the Zn-reduction method could be replaced by the Pt-equilibration method when TEE was estimated using the "Multi-Point" technique. Furthermore, D equilibration time was significantly reduced.

Experimental investigation of the Multipoint Ultrasonic Flowmeter

NASA Astrophysics Data System (ADS)

Jakub, Filipský

2018-06-01

The Multipoint Ultrasonic Flowmeter is a vector tomographic device capable of reconstructing all three components of velocity field based solely on boundary ultrasonic measurements. Computer simulations have shown the feasibility of such a device and have been published previously. This paper describes an experimental investigation of achievable accuracy of such a method. Doubled acoustic tripoles used to obtain information of the solenoidal part of vector field show extremely short differences between the Time Of Flights (TOFs) of individual sensors and are therefore sensitive to parasitic effects of TOF measurements. Sampling at 40MHz and correlation method is used to measure the TOF.

Development and accuracy of a multipoint method for measuring visibility.

PubMed

Tai, Hongda; Zhuang, Zibo; Sun, Dongsong

2017-10-01

Accurate measurements of visibility are of great importance in many fields. This paper reports a multipoint visibility measurement (MVM) method to measure and calculate the atmospheric transmittance, extinction coefficient, and meteorological optical range (MOR). The relative errors of atmospheric transmittance and MOR measured by the MVM method and traditional transmissometer method are analyzed and compared. Experiments were conducted indoors, and the data were simultaneously processed. The results revealed that the MVM can effectively improve the accuracy under different visibility conditions. The greatest improvement of accuracy was 27%. The MVM can be used to calibrate and evaluate visibility meters.

Two-way digital communications

NASA Astrophysics Data System (ADS)

Glenn, William E.; Daly, Ed

1996-03-01

The communications industry has been rapidly converting from analog to digital communications for audio, video, and data. The initial applications have been concentrating on point-to-multipoint transmission. Currently, a new revolution is occurring in which two-way point-to-point transmission is a rapidly growing market. The system designs for video compression developed for point-to-multipoint transmission are unsuitable for this new market as well as for satellite based video encoding. A new system developed by the Space Communications Technology Center has been designed to address both of these newer applications. An update on the system performance and design will be given.

On the Interconnection of Incompatible Solid Finite Element Meshes Using Multipoint Constraints

NASA Technical Reports Server (NTRS)

Fox, G. L.

1985-01-01

Incompatible meshes, i.e., meshes that physically must have a common boundary, but do not necessarily have coincident grid points, can arise in the course of a finite element analysis. For example, two substructures may have been developed at different times for different purposes and it becomes necessary to interconnect the two models. A technique that uses only multipoint constraints, i.e., MPC cards (or MPCS cards in substructuring), is presented. Since the method uses only MPC's, the procedure may apply at any stage in an analysis; no prior planning or special data is necessary.

Multipoint attachment to a support protects enzyme from inactivation by organic solvents: alpha-Chymotrypsin in aqueous solutions of alcohols and diols.

PubMed

Mozhaev, V V; Sergeeva, M V; Belova, A B; Khmelnitsky, Y L

1990-03-25

Inactivation of alpha-chymotrypsin in aqueous solutions of alcohols and diols proceeds both reversibly and irreversibly. Reversible loss of the specific enzyme activity results from conformational changes (unfolding) of the enzyme detected by fluorescence spectroscopy. Multipoint covalent attachment to the matrix of polyacryl-amide gel by copolymerization method stabilizes alpha-chymotrypsin from denaturation by alcohols, the stabilizing effect increasing with the number of bonds between the protein and the support. Immobilization protects the enzyme also from irreversible inactivation by organic solvents resulting from bimolecular aggregation and autolysis.

On-board measurement of emissions from liquefied petroleum gas, gasoline and diesel powered passenger cars in Algeria.

PubMed

Chikhi, Saâdane; Boughedaoui, Ménouèr; Kerbachi, Rabah; Joumard, Robert

2014-08-01

On-board measurements of unit emissions of CO, HC, NOx and CO₂ were conducted on 17 private cars powered by different types of fuels including gasoline, dual gasoline-liquefied petroleum gas (LPG), gasoline, and diesel. The tests performed revealed the effect of LPG injection technology on unit emissions and made it possible to compare the measured emissions to the European Artemis emission model. A sequential multipoint injection LPG kit with no catalyst installed was found to be the most efficient pollutant reduction device for all of the pollutants, with the exception of the NOx. Specific test results for a sub-group of LPG vehicles revealed that LPG-fueled engines with no catalyst cannot compete with catalyzed gasoline and diesel engines. Vehicle age does not appear to be a determining parameter with regard to vehicle pollutant emissions. A fuel switch to LPG offers many advantages as far as pollutant emissions are concerned, due to LPG's intrinsic characteristics. However, these advantages are being rapidly offset by the strong development of both gasoline and diesel engine technologies and catalyst converters. The LPG's performance on a chassis dynamometer under real driving conditions was better than expected. The enforcement of pollutant emission standards in developing countries is an important step towards introducing clean technology and reducing vehicle emissions. Copyright © 2014. Published by Elsevier B.V.

Future Modelling and Simulation Challenges (Defis futurs pour la modelisation et la simulation)

DTIC Science & Technology

2002-11-01

Language School Figure 2: Location of the simulation center within the MEC Military operations research section - simulation lab Military operations... language . This logic can be probabilistic (branching is randomised, which is useful for modelling error), tactical (a branch goes to the task with the... language and a collection of simulation tools that can be used to create human and team behaviour models to meet users’ needs. Hence, different ways of

Multi-Point Measurements to Characterize Radiation Belt Electron Precipitation Loss

NASA Astrophysics Data System (ADS)

Blum, L. W.

2017-12-01

Multipoint measurements in the inner magnetosphere allow the spatial and temporal evolution of various particle populations and wave modes to be disentangled. To better characterize and quantify radiation belt precipitation loss, we utilize multi-point measurements both to study precipitating electrons directly as well as the potential drivers of this loss process. Magnetically conjugate CubeSat and balloon measurements are combined to estimate of the temporal and spatial characteristics of dusk-side precipitation features and quantify loss due to these events. To then understand the drivers of precipitation events, and what determines their spatial structure, we utilize measurements from the dual Van Allen Probes to estimate spatial and temporal scales of various wave modes in the inner magnetosphere, and compare these to precipitation characteristics. The structure, timing, and spatial extent of waves are compared to those of MeV electron precipitation during a few individual events to determine when and where EMIC waves cause radiation belt electron precipitation. Magnetically conjugate measurements provide observational support of the theoretical picture of duskside interaction of EMIC waves and MeV electrons leading to radiation belt loss. Finally, understanding the drivers controlling the spatial scales of wave activity in the inner magnetosphere is critical for uncovering the underlying physics behind the wave generation as well as for better predicting where and when waves will be present. Again using multipoint measurements from the Van Allen Probes, we estimate the spatial and temporal extents and evolution of plasma structures and their gradients in the inner magnetosphere, to better understand the drivers of magnetospheric wave characteristic scales. In particular, we focus on EMIC waves and the plasma parameters important for their growth, namely cold plasma density and cool and warm ion density, anisotropy, and composition.

Optimization of bump and blowing to control the flow through a transonic compressor blade cascade

NASA Astrophysics Data System (ADS)

Mazaheri, K.; Khatibirad, S.

2018-03-01

Shock control bump (SCB) and blowing are two flow control methods, used here to improve the aerodynamic performance of transonic compressors. Both methods are applied to a NASA rotor 67 blade section and are optimized to minimize the total pressure loss. A continuous adjoint algorithm is used for multi-point optimization of a SCB to improve the aerodynamic performance of the rotor blade section, for a range of operational conditions around its design point. A multi-point and two single-point optimizations are performed in the design and off-design conditions. It is shown that the single-point optimized shapes have the best performance for their respective operating conditions, but the multi-point one has an overall better performance over the whole operating range. An analysis is given regarding how similarly both single- and multi-point optimized SCBs change the wave structure between blade sections resulting in a more favorable flow pattern. Interactions of the SCB with the boundary layer and the wave structure, and its effects on the separation regions are also studied. We have also introduced the concept of blowing for control of shock wave and boundary-layer interaction. A geometrical model is introduced, and the geometrical and physical parameters of blowing are optimized at the design point. The performance improvements of blowing are compared with the SCB. The physical interactions of SCB with the boundary layer and the shock wave are analyzed. The effects of SCB on the wave structure in the flow domain outside the boundary-layer region are investigated. It is shown that the effects of the blowing mechanism are very similar to the SCB.

Regulation of protein multipoint adsorption on ion-exchange adsorbent and its application to the purification of macromolecules.

PubMed

Huang, Yongdong; Bi, Jingxiu; Zhao, Lan; Ma, Guanghui; Su, Zhiguo

2010-12-01

Ion-exchange chromatography (IEC) using commercial ionic absorbents is a widely used technique for protein purification. Protein adsorption onto ion-exchange adsorbents often involves a multipoint adsorption. In IEC of multimeric proteins or "soft" proteins, the intense multipoint binding would make the further desorption difficult, even lead to the destruction of protein structure and the loss of its biological activity. In this paper, DEAE Sepharose FF adsorbents with controllable ligand densities from 0.020 to 0.183 mmol/ml were synthesized, and then the effect of ligand density on the static ion-exchange adsorption of bovine serum albumin (BSA) onto DEAE Sepharose FF was studied by batch adsorption technique. Steric mass-action (SMA) model was employed to analyze the static adsorption behavior. The results showed that the SMA model parameters, equilibrium constant (K(a)), characteristic number of binding sites (υ) and steric factor (σ), increased gradually with ligand density. Thus, it was feasible to regulate BSA multipoint adsorption by modulating the ligand density of ion-exchange adsorbent. Furthermore, IEC of hepatitis B surface antigen (HBsAg) using DEAE Sepharose FF adsorbents with different ligand densities was carried out, and the activity recovery of HBsAg was improved from 42% to 67% when the ligand density was decreased from 0.183 to 0.020 mmol/ml. Taking the activity recovery of HBsAg, the purification factor and the binding capacity into account, DEAE Sepharose FF with a ligand density of 0.041 mmol/ml was most effective for the purification of HBsAg. Such a strategy may also be beneficial for the purification of macromolecules and multimeric proteins. Copyright © 2010 Elsevier Inc. All rights reserved.

A risk-based multi-objective model for optimal placement of sensors in water distribution system

NASA Astrophysics Data System (ADS)

Naserizade, Sareh S.; Nikoo, Mohammad Reza; Montaseri, Hossein

2018-02-01

In this study, a new stochastic model based on Conditional Value at Risk (CVaR) and multi-objective optimization methods is developed for optimal placement of sensors in water distribution system (WDS). This model determines minimization of risk which is caused by simultaneous multi-point contamination injection in WDS using CVaR approach. The CVaR considers uncertainties of contamination injection in the form of probability distribution function and calculates low-probability extreme events. In this approach, extreme losses occur at tail of the losses distribution function. Four-objective optimization model based on NSGA-II algorithm is developed to minimize losses of contamination injection (through CVaR of affected population and detection time) and also minimize the two other main criteria of optimal placement of sensors including probability of undetected events and cost. Finally, to determine the best solution, Preference Ranking Organization METHod for Enrichment Evaluation (PROMETHEE), as a subgroup of Multi Criteria Decision Making (MCDM) approach, is utilized to rank the alternatives on the trade-off curve among objective functions. Also, sensitivity analysis is done to investigate the importance of each criterion on PROMETHEE results considering three relative weighting scenarios. The effectiveness of the proposed methodology is examined through applying it to Lamerd WDS in the southwestern part of Iran. The PROMETHEE suggests 6 sensors with suitable distribution that approximately cover all regions of WDS. Optimal values related to CVaR of affected population and detection time as well as probability of undetected events for the best optimal solution are equal to 17,055 persons, 31 mins and 0.045%, respectively. The obtained results of the proposed methodology in Lamerd WDS show applicability of CVaR-based multi-objective simulation-optimization model for incorporating the main uncertainties of contamination injection in order to evaluate extreme value of losses in WDS.

Etude numerique et experimentale de la reponse vibro-acoustique des structures raidies a des excitations aeriennes et solidiennes

NASA Astrophysics Data System (ADS)

Mejdi, Abderrazak

Les fuselages des avions sont generalement en aluminium ou en composite renforces par des raidisseurs longitudinaux (lisses) et transversaux (cadres). Les raidisseurs peuvent etre metalliques ou en composite. Durant leurs differentes phases de vol, les structures d'avions sont soumises a des excitations aeriennes (couche limite turbulente : TBL, champs diffus : DAF) sur la peau exterieure dont l'energie acoustique produite se transmet a l'interieur de la cabine. Les moteurs, montes sur la structure, produisent une excitation solidienne significative. Ce projet a pour objectifs de developper et de mettre en place des strategies de modelisations des fuselages d'avions soumises a des excitations aeriennes et solidiennes. Tous d'abord, une mise a jour des modeles existants de la TBL apparait dans le deuxieme chapitre afin de mieux les classer. Les proprietes de la reponse vibro-acoustique des structures planes finies et infinies sont analysees. Dans le troisieme chapitre, les hypotheses sur lesquelles sont bases les modeles existants concernant les structures metalliques orthogonalement raidies soumises a des excitations mecaniques, DAF et TBL sont reexamines en premier lieu. Ensuite, une modelisation fine et fiable de ces structures est developpee. Le modele est valide numeriquement a l'aide des methodes des elements finis (FEM) et de frontiere (BEM). Des tests de validations experimentales sont realises sur des panneaux d'avions fournis par des societes aeronautiques. Au quatrieme chapitre, une extension vers les structures composites renforcees par des raidisseurs aussi en composites et de formes complexes est etablie. Un modele analytique simple est egalement implemente et valide numeriquement. Au cinquieme chapitre, la modelisation des structures raidies periodiques en composites est beaucoup plus raffinee par la prise en compte des effets de couplage des deplacements planes et transversaux. L'effet de taille des structures finies periodiques est egalement pris en compte. Les modeles developpes ont permis de conduire plusieurs etudes parametriques sur les proprietes vibro-acoustiques des structures d'avions facilitant ainsi la tache des concepteurs. Dans le cadre de cette these, un article a ete publie dans le Journal of Sound and Vibration et trois autres soumis, respectivement aux Journal of Acoustical Society of America, International Journal of Solid Mechanics et au Journal of Sound and Vibration Mots cles : structures raidies, composites, vibro-acoustique, perte par transmission.

Modelisation frequentielle de la permittivite du beton pour le controle non destructif par georadar

NASA Astrophysics Data System (ADS)

Bourdi, Taoufik

Le georadar (Ground Penetrating Radar (GPR)) constitue une technique de controle non destructif (CND) interessante pour la mesure des epaisseurs des dalles de beton et la caracterisation des fractures, en raison de ses caracteristiques de resolution et de profondeur de penetration. Les equipements georadar sont de plus en plus faciles a utiliser et les logiciels d'interpretation sont en train de devenir plus aisement accessibles. Cependant, il est ressorti dans plusieurs conferences et ateliers sur l'application du georadar en genie civil qu'il fallait poursuivre les recherches, en particulier sur la modelisation et les techniques de mesure des proprietes electriques du beton. En obtenant de meilleures informations sur les proprietes electriques du beton aux frequences du georadar, l'instrumentation et les techniques d'interpretation pourraient etre perfectionnees plus efficacement. Le modele de Jonscher est un modele qui a montre son efficacite dans le domaine geophysique. Pour la premiere fois, son utilisation dans le domaine genie civil est presentee. Dans un premier temps, nous avons valide l'application du modele de Jonscher pour la caracterisation de la permittivite dielectrique du beton. Les resultats ont montre clairement que ce modele est capable de reproduire fidelement la variation de la permittivite de differents types de beton sur la bande de frequence georadar (100 MHz-2 GHz). Dans un deuxieme temps, nous avons montre l'interet du modele de Jonscher en le comparant a d'autres modeles (Debye et Debye-etendu) deja utilises dans le domaine genie civil. Nous avons montre aussi comment le modele de Jonscher peut presenter une aide a la prediction de l'efficacite de blindage et a l'interpretation des ondes de la technique GPR. Il a ete determine que le modele de Jonscher permet de donner une bonne presentation de la variation de la permittivite du beton dans la gamme de frequence georadar consideree. De plus, cette modelisation est valable pour differents types de beton et a differentes teneurs en eau. Dans une derniere partie, nous avons presente l'utilisation du modele de Jonscher pour l'estimation de l'epaisseur d'une dalle de beton par la technique GPR dans le domaine frequentiel. Mots-cles : CND, beton, georadar , permittivite, Jonscher

Comparison of multipoint linkage analyses for quantitative traits in the CEPH data: parametric LOD scores, variance components LOD scores, and Bayes factors.

PubMed

Sung, Yun Ju; Di, Yanming; Fu, Audrey Q; Rothstein, Joseph H; Sieh, Weiva; Tong, Liping; Thompson, Elizabeth A; Wijsman, Ellen M

2007-01-01

We performed multipoint linkage analyses with multiple programs and models for several gene expression traits in the Centre d'Etude du Polymorphisme Humain families. All analyses provided consistent results for both peak location and shape. Variance-components (VC) analysis gave wider peaks and Bayes factors gave fewer peaks. Among programs from the MORGAN package, lm_multiple performed better than lm_markers, resulting in less Markov-chain Monte Carlo (MCMC) variability between runs, and the program lm_twoqtl provided higher LOD scores by also including either a polygenic component or an additional quantitative trait locus.

Comparison of multipoint linkage analyses for quantitative traits in the CEPH data: parametric LOD scores, variance components LOD scores, and Bayes factors

PubMed Central

Sung, Yun Ju; Di, Yanming; Fu, Audrey Q; Rothstein, Joseph H; Sieh, Weiva; Tong, Liping; Thompson, Elizabeth A; Wijsman, Ellen M

2007-01-01

We performed multipoint linkage analyses with multiple programs and models for several gene expression traits in the Centre d'Etude du Polymorphisme Humain families. All analyses provided consistent results for both peak location and shape. Variance-components (VC) analysis gave wider peaks and Bayes factors gave fewer peaks. Among programs from the MORGAN package, lm_multiple performed better than lm_markers, resulting in less Markov-chain Monte Carlo (MCMC) variability between runs, and the program lm_twoqtl provided higher LOD scores by also including either a polygenic component or an additional quantitative trait locus. PMID:18466597

Space Technology 5 Multipoint Observations of Temporal and Spatial Variability of Field-Aligned Currents

NASA Technical Reports Server (NTRS)

Le, G.; Wang, Y.; Slavin, J. A.; Strangeway, R. L.

2009-01-01

Space Technology 5 (ST5) is a constellation mission consisting of three microsatellites. It provides the first multipoint magnetic field measurements in low Earth orbit, which enables us to separate spatial and temporal variations. In this paper, we present a study of the temporal variability of field-aligned currents using the ST5 data. We examine the field-aligned current observations during and after a geomagnetic storm and compare the magnetic field profiles at the three spacecraft. The multipoint data demonstrate that mesoscale current structures, commonly embedded within large-scale current sheets, are very dynamic with highly variable current density and/or polarity in approx.10 min time scales. On the other hand, the data also show that the time scales for the currents to be relatively stable are approx.1 min for mesoscale currents and approx.10 min for large-scale currents. These temporal features are very likely associated with dynamic variations of their charge carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of mesoscale field-aligned currents are found to be consistent with those of auroral parallel electric field.

Exploring microwave resonant multi-point ignition using high-speed schlieren imaging

NASA Astrophysics Data System (ADS)

Liu, Cheng; Zhang, Guixin; Xie, Hong; Deng, Lei; Wang, Zhi

2018-03-01

Microwave plasma offers a potential method to achieve rapid combustion in a high-speed combustor. In this paper, microwave resonant multi-point ignition and its control method have been studied via high-speed schlieren imaging. The experiment was conducted with the microwave resonant ignition system and the schlieren optical system. The microwave pulse in 2.45 GHz with 2 ms width and 3 kW peak power was employed as an ignition energy source to produce initial flame kernels in the combustion chamber. A reflective schlieren method was designed to illustrate the flame development process with a high-speed camera. The bottom of the combustion chamber was made of a quartz glass coated with indium tin oxide, which ensures sufficient microwave reflection and light penetration. Ignition experiments were conducted at 2 bars of stoichiometric methane-air mixtures. Schlieren images show that flame kernels were generated at more than one location simultaneously and flame propagated with different speeds in different flame kernels. Ignition kernels were discussed in three types according to their appearances. Pressure curves and combustion duration also show that multi-point ignition plays a significant role in accelerating combustion.

Online System for Faster Multipoint Linkage Analysis via Parallel Execution on Thousands of Personal Computers

PubMed Central

Silberstein, M.; Tzemach, A.; Dovgolevsky, N.; Fishelson, M.; Schuster, A.; Geiger, D.

2006-01-01

Computation of LOD scores is a valuable tool for mapping disease-susceptibility genes in the study of Mendelian and complex diseases. However, computation of exact multipoint likelihoods of large inbred pedigrees with extensive missing data is often beyond the capabilities of a single computer. We present a distributed system called “SUPERLINK-ONLINE,” for the computation of multipoint LOD scores of large inbred pedigrees. It achieves high performance via the efficient parallelization of the algorithms in SUPERLINK, a state-of-the-art serial program for these tasks, and through the use of the idle cycles of thousands of personal computers. The main algorithmic challenge has been to efficiently split a large task for distributed execution in a highly dynamic, nondedicated running environment. Notably, the system is available online, which allows computationally intensive analyses to be performed with no need for either the installation of software or the maintenance of a complicated distributed environment. As the system was being developed, it was extensively tested by collaborating medical centers worldwide on a variety of real data sets, some of which are presented in this article. PMID:16685644

Exploring microwave resonant multi-point ignition using high-speed schlieren imaging.

PubMed

Liu, Cheng; Zhang, Guixin; Xie, Hong; Deng, Lei; Wang, Zhi

2018-03-01

Microwave plasma offers a potential method to achieve rapid combustion in a high-speed combustor. In this paper, microwave resonant multi-point ignition and its control method have been studied via high-speed schlieren imaging. The experiment was conducted with the microwave resonant ignition system and the schlieren optical system. The microwave pulse in 2.45 GHz with 2 ms width and 3 kW peak power was employed as an ignition energy source to produce initial flame kernels in the combustion chamber. A reflective schlieren method was designed to illustrate the flame development process with a high-speed camera. The bottom of the combustion chamber was made of a quartz glass coated with indium tin oxide, which ensures sufficient microwave reflection and light penetration. Ignition experiments were conducted at 2 bars of stoichiometric methane-air mixtures. Schlieren images show that flame kernels were generated at more than one location simultaneously and flame propagated with different speeds in different flame kernels. Ignition kernels were discussed in three types according to their appearances. Pressure curves and combustion duration also show that multi-point ignition plays a significant role in accelerating combustion.

3D Modelling of Urban Terrain (Modelisation 3D de milieu urbain)

DTIC Science & Technology

2011-09-01

Panel • IST Information Systems Technology Panel • NMSG NATO Modelling and Simulation Group • SAS System Analysis and Studies Panel • SCI... Systems Concepts and Integration Panel • SET Sensors and Electronics Technology Panel These bodies are made up of national representatives as well as...of a part of it may be made for individual use only. The approval of the RTA Information Management Systems Branch is required for more than one

CT-guided percutaneous ethanol injection with disposable curved needle for treatment of malignant liver neoplasms and their metastases in retroperitoneal lymph nodes

PubMed Central

Zuo, Chang-Jing; Wang, Pei-Jun; Shao, Cheng-Wei; Wang, Min-Jie; Tian, Jian-Ming; Xiao, Yi; Ren, Fang-Yuan; Hao, Xi-Yan; Yuan, Min

2004-01-01

AIM: To explore the feasibility of computed tomography (CT)-guided percutaneous ethanol injection (PEI) using a disposable curved needle for treatment of malignant liver neoplasms and their metastases in retroperitoneal lymph nodes. METHODS: CT-guided PEI was conducted using a disposable curved needle in 26 malignant liver tumors smaller than 5 cm in diameter and 5 lymph node metastases of liver cancer in the retroperitoneal space. The disposable curved needle was composed of a straight trocar (21G) and stylet, a disposable curved tip (25 G) and a fine stylet. For the tumors found in deep sites and difficult to reach, or for hepatic masses inaccessible to the injection using a straight needle because of portal vein and bile ducts, the straight trocar was used at first to reach the side of the tumor. Then, the disposable curved needle was used via the trocar. When the needle reached the tumor center, appropriate amount of ethanol was injected. For relatively large malignant liver tumors, multi-point injection was carried out for a better distribution of the ethanol injected throughout the masses. The curved needle was also used for treatment of the metastasis in retroperitoneal lymph nodes blocked by blood vessels and inaccessible by the straight needle. RESULTS: All of the 26 liver tumors received 2 or more times of successful PEI, through which ethanol was distributed throughout the whole tumor mass. Effect of the treatment was monitored by contrast-enhanced multi-phase CT and magnetic resonance imaging (MRI) examinations three months later. Of the 18 lesions whose diameters were smaller than 3 cm, the necrotic change across the whole mass and that in most areas were observed in 15 and 3 tumors, respectively. Among the 8 tumors sizing up to 5 cm, 5 were completely necrotic and 3 largely necrotic. Levels of tumor seromarkers were significantly reduced in some of the cases. In 5 patients with metastases of liver cancer in retroperitoneal lymph nodes who received 1 to 3 times of PEI, all the foci treated were completely necrotic and smaller demonstrated by dynamic contrast-enhanced CT or MRI 3 months later. CONCLUSION: CT-guided PEI using a disposable curved needle is effective, time-saving and convenient, providing an alternative therapy for the treatment of malignant liver tumors and their retroperitoneal lymph node metastases. PMID:14695769

Understanding and Modeling Vortical Flows to Improve the Technology Readiness Level for Military Aircraft (Comprehension et Modelisation des Flux de Vortex Pour Ameliorer le Niveau de Maturite Technologique au Profit des Avions Militaires)

DTIC Science & Technology

2009-10-01

636.7 115,418 0 2500 5000 7500 10000 12500 iterations -5 -4 -3 -2 -1 0 lo g( dρ /d t) SA EARSM EARSM + CC Hellsten EARSM Hellsten EARSM + CC DRSM...VORTEX BREAKDOWN RTO-TR-AVT-113 29 - 13 θU URo axial= (1) As a vortex passes through a normal shock, the tangential velocity is

Human Behaviour Representation in Constructive Modelling (Representation du comportement humain dans des modelisations creatives)

DTIC Science & Technology

2009-09-01

involved in R&T activities. RTO reports both to the Military Committee of NATO and to the Conference of National Armament Directors. It comprises a...4 11.5.3 Project Description 11-5 Chapter 12 – Technical Evaluation Report 12-1 12.1 Executive Summary 12-1 12.2 Introduction 12-2 12.3...modelling human factors has been slow over the past decade, other forums have been reporting a number of theoretical and applied papers on human behaviour

Human Behaviour Representation in Constructive Modelling (Representation du comportement humain dans des modelisations creatives)

DTIC Science & Technology

2009-09-01

ordination with other NATO bodies involved in R&T activities. RTO reports both to the Military Committee of NATO and to the Conference of National...Aims 11-4 11.5.2 Background 11-4 11.5.3 Project Description 11-5 Chapter 12 – Technical Evaluation Report 12-1 12.1 Executive Summary 12-1...track. Although progress in modelling human factors has been slow over the past decade, other forums have been reporting a number of theoretical and

Synchronous high speed multi-point velocity profile measurement by heterodyne interferometry

NASA Astrophysics Data System (ADS)

Hou, Xueqin; Xiao, Wen; Chen, Zonghui; Qin, Xiaodong; Pan, Feng

2017-02-01

This paper presents a synchronous multipoint velocity profile measurement system, which acquires the vibration velocities as well as images of vibrating objects by combining optical heterodyne interferometry and a high-speed CMOS-DVR camera. The high-speed CMOS-DVR camera records a sequence of images of the vibrating object. Then, by extracting and processing multiple pixels at the same time, a digital demodulation technique is implemented to simultaneously acquire the vibrating velocity of the target from the recorded sequences of images. This method is validated with an experiment. A piezoelectric ceramic plate with standard vibration characteristics is used as the vibrating target, which is driven by a standard sinusoidal signal.

A measurement technique of time-dependent dielectric breakdown in MOS capacitors

NASA Technical Reports Server (NTRS)

Li, S. P.

1974-01-01

The statistical nature of time-dependent dielectric breakdown characteristics in MOS capacitors was evidenced by testing large numbers of capacitors fabricated on single wafers. A multipoint probe and automatic electronic visual display technique are introduced that will yield statistical results which are necessary for the investigation of temperature, electric field, thermal annealing, and radiation effects in the breakdown characteristics, and an interpretation of the physical mechanisms involved. It is shown that capacitors of area greater than 0.002 sq cm may yield worst-case results, and that a multipoint probe of capacitors of smaller sizes can be used to obtain a profile of nonuniformities in the SiO2 films.

Error analysis of multipoint flux domain decomposition methods for evolutionary diffusion problems

NASA Astrophysics Data System (ADS)

Arrarás, A.; Portero, L.; Yotov, I.

2014-01-01

We study space and time discretizations for mixed formulations of parabolic problems. The spatial approximation is based on the multipoint flux mixed finite element method, which reduces to an efficient cell-centered pressure system on general grids, including triangles, quadrilaterals, tetrahedra, and hexahedra. The time integration is performed by using a domain decomposition time-splitting technique combined with multiterm fractional step diagonally implicit Runge-Kutta methods. The resulting scheme is unconditionally stable and computationally efficient, as it reduces the global system to a collection of uncoupled subdomain problems that can be solved in parallel without the need for Schwarz-type iteration. Convergence analysis for both the semidiscrete and fully discrete schemes is presented.

Multipoint vibrometry with dynamic and static holograms.

PubMed

Haist, T; Lingel, C; Osten, W; Winter, M; Giesen, M; Ritter, F; Sandfort, K; Rembe, C; Bendel, K

2013-12-01

We report on two multipoint vibrometers with user-adjustable position of the measurement spots. Both systems are using holograms for beam deflection. The measurement is based on heterodyne interferometry with a frequency difference of 5 MHz between reference and object beam. One of the systems uses programmable positioning of the spots in the object volume but is limited concerning the light efficiency. The other system is based on static holograms in combination with mechanical adjustment of the measurement spots and does not have such a general efficiency restriction. Design considerations are given and we show measurement results for both systems. In addition, we analyze the sensitivity of the systems which is a major limitation compared to single point scanning systems.

A newly identified calculation discrepancy of the Sunset semi-continuous carbon analyzer

NASA Astrophysics Data System (ADS)

Zheng, G.; Cheng, Y.; He, K.; Duan, F.; Ma, Y.

2014-01-01

Sunset Semi-Continuous Carbon Analyzer (SCCA) is an instrument widely used for carbonaceous aerosol measurement. Despite previous validation work, here we identified a new type of SCCA calculation discrepancy caused by the default multi-point baseline correction method. When exceeding a certain threshold carbon load, multi-point correction could cause significant Total Carbon (TC) underestimation. This calculation discrepancy was characterized for both sucrose and ambient samples with three temperature protocols. For ambient samples, 22%, 36% and 12% TC was underestimated by the three protocols, respectively, with corresponding threshold being ~0, 20 and 25 μg C. For sucrose, however, such discrepancy was observed with only one of these protocols, indicating the need of more refractory SCCA calibration substance. The discrepancy was less significant for the NIOSH (National Institute for Occupational Safety and Health)-like protocol compared with the other two protocols based on IMPROVE (Interagency Monitoring of PROtected Visual Environments). Although the calculation discrepancy could be largely reduced by the single-point baseline correction method, the instrumental blanks of single-point method were higher. Proposed correction method was to use multi-point corrected data when below the determined threshold, while use single-point results when beyond that threshold. The effectiveness of this correction method was supported by correlation with optical data.

A newly identified calculation discrepancy of the Sunset semi-continuous carbon analyzer

NASA Astrophysics Data System (ADS)

Zheng, G. J.; Cheng, Y.; He, K. B.; Duan, F. K.; Ma, Y. L.

2014-07-01

The Sunset semi-continuous carbon analyzer (SCCA) is an instrument widely used for carbonaceous aerosol measurement. Despite previous validation work, in this study we identified a new type of SCCA calculation discrepancy caused by the default multipoint baseline correction method. When exceeding a certain threshold carbon load, multipoint correction could cause significant total carbon (TC) underestimation. This calculation discrepancy was characterized for both sucrose and ambient samples, with two protocols based on IMPROVE (Interagency Monitoring of PROtected Visual Environments) (i.e., IMPshort and IMPlong) and one NIOSH (National Institute for Occupational Safety and Health)-like protocol (rtNIOSH). For ambient samples, the IMPshort, IMPlong and rtNIOSH protocol underestimated 22, 36 and 12% of TC, respectively, with the corresponding threshold being ~ 0, 20 and 25 μgC. For sucrose, however, such discrepancy was observed only with the IMPshort protocol, indicating the need of more refractory SCCA calibration substance. Although the calculation discrepancy could be largely reduced by the single-point baseline correction method, the instrumental blanks of single-point method were higher. The correction method proposed was to use multipoint-corrected data when below the determined threshold, and use single-point results when beyond that threshold. The effectiveness of this correction method was supported by correlation with optical data.

The radiation-belt electron phase-space-density response to stream-interaction regions: A study combining multi-point observations, data-assimilation, and physics-based modeling

NASA Astrophysics Data System (ADS)

Kellerman, A. C.; Shprits, Y.; McPherron, R. L.; Kondrashov, D. A.; Weygand, J. M.; Zhu, H.; Drozdov, A.

2017-12-01

Presented is an analysis of the phase-space density (PSD) response to the stream-interaction region (SIR), which utilizes a reanalysis dataset principally comprised of the data-assimilative Versatile Electron Radiation Belt (VERB) code, Van Allen Probe and GOES observations. The dataset spans the period 2012-2017, and includes several SIR (and CIR) storms. The PSD is examined for evidence of injections, transport, acceleration, and loss by considering the instantaneous and time-averaged change at adiabatic invariant values that correspond to ring-current, relativistic, and ultra-relativistic energies. In the solar wind, the following variables in the slow and fast wind on either side of the stream interface (SI) are considered in each case: the coronal hole polarity, IMF, solar wind speed, density, pressure, and SI tilt angle. In the magnetosphere, the Dst, AE, and past PSD state are considered. Presented is an analysis of the dominant mechanisms, both external and internal to the magnetosphere, that cause radiation-belt electron non-adiabatic changes during the passage of these fascinating solar wind structures.

The combustion behavior of diesel/CNG mixtures in a constant volume combustion chamber

NASA Astrophysics Data System (ADS)

Firmansyah; Aziz, A. R. A.; Heikal, M. R.

2015-12-01

The stringent emissions and needs to increase fuel efficiency makes controlled auto-ignition (CAI) based combustion an attractive alternative for the new combustion system. However, the combustion control is the main obstacles in its development. Reactivity controlled compression ignition (RCCI) that employs two fuels with significantly different in reactivity proven to be able to control the combustion. The RCCI concept applied in a constant volume chamber fuelled with direct injected diesel and compressed natural gas (CNG) was tested. The mixture composition is varied from 0 - 100% diesel/CNG at lambda 1 with main data collection are pressure profile and combustion images. The results show that diesel-CNG mixture significantly shows better combustion compared to diesel only. It is found that CNG is delaying the diesel combustion and at the same time assisting in diesel distribution inside the chamber. This combination creates a multipoint ignition of diesel throughout the chamber that generate very fast heat release rate and higher maximum pressure. Furthermore, lighter yellow color of the flame indicates lower soot production in compared with diesel combustion.

Advanced analysis of forest fire clustering

NASA Astrophysics Data System (ADS)

Kanevski, Mikhail; Pereira, Mario; Golay, Jean

2017-04-01

Analysis of point pattern clustering is an important topic in spatial statistics and for many applications: biodiversity, epidemiology, natural hazards, geomarketing, etc. There are several fundamental approaches used to quantify spatial data clustering using topological, statistical and fractal measures. In the present research, the recently introduced multi-point Morisita index (mMI) is applied to study the spatial clustering of forest fires in Portugal. The data set consists of more than 30000 fire events covering the time period from 1975 to 2013. The distribution of forest fires is very complex and highly variable in space. mMI is a multi-point extension of the classical two-point Morisita index. In essence, mMI is estimated by covering the region under study by a grid and by computing how many times more likely it is that m points selected at random will be from the same grid cell than it would be in the case of a complete random Poisson process. By changing the number of grid cells (size of the grid cells), mMI characterizes the scaling properties of spatial clustering. From mMI, the data intrinsic dimension (fractal dimension) of the point distribution can be estimated as well. In this study, the mMI of forest fires is compared with the mMI of random patterns (RPs) generated within the validity domain defined as the forest area of Portugal. It turns out that the forest fires are highly clustered inside the validity domain in comparison with the RPs. Moreover, they demonstrate different scaling properties at different spatial scales. The results obtained from the mMI analysis are also compared with those of fractal measures of clustering - box counting and sand box counting approaches. REFERENCES Golay J., Kanevski M., Vega Orozco C., Leuenberger M., 2014: The multipoint Morisita index for the analysis of spatial patterns. Physica A, 406, 191-202. Golay J., Kanevski M. 2015: A new estimator of intrinsic dimension based on the multipoint Morisita index. Pattern Recognition, 48, 4070-4081.

Estimation of the effects of multipoint pacing on battery longevity in routine clinical practice.

PubMed

Akerström, Finn; Narváez, Irene; Puchol, Alberto; Pachón, Marta; Martín-Sierra, Cristina; Rodríguez-Mañero, Moisés; Rodríguez-Padial, Luis; Arias, Miguel A

2017-09-23

Multipoint pacing (MPP) permits simultaneous multisite pacing of the left ventricle (LV); initial studies suggest haemodynamic and clinical benefits over conventional (single LV site) cardiac resynchronization therapy (CRT). The aim of this study was to estimate the impact of MPP activation on battery longevity in routine clinical practice. Patient (n = 46) and device data were collected from two centres at least 3 months after MPP-CRT device implantation. Multipoint pacing programming was based on the maximal possible anatomical LV1/LV2 separation according to three predefined LV pacing capture threshold (PCT) cut-offs (≤1.5 V; ≤4.0 V; and ≤6.5 V). Estimated battery longevity was calculated using the programmed lower rate limit, lead impedances, outputs, and pacing percentages. Relative to the longevity for conventional CRT using the lowest PCT (8.9 ± 1.2 years), MPP activation significantly shortened battery longevity for all three PCT cut-offs (≤1.5 V, -5.6%; ≤4.0 V, -16.9%; ≤6.5 V, -21.3%; P's <0.001). When compared with conventional CRT based on longest right ventricle-LV delay (8.3 ± 1.3 years), battery longevity was significantly shortened for the MPP ≤ 4.0 V and ≤6.5 V cut-offs (-10.8 and -15.7%, respectively; P's <0.001). Maximal LV1/LV2 spacing was possible in 23.9% (≤1.5 V), 56.5% (≤4.0 V), and 69.6% (≤6.5 V) of patients. Multipoint pacing activation significantly reduces battery longevity compared with that for conventional CRT configuration. When reasonable MPP LV vector PCTs (≤4.0 V) are achieved, the decrease in battery longevity is relatively small which may prompt the clinician to activate MPP. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

An approach for aerodynamic optimization of transonic fan blades

NASA Astrophysics Data System (ADS)

Khelghatibana, Maryam

Aerodynamic design optimization of transonic fan blades is a highly challenging problem due to the complexity of flow field inside the fan, the conflicting design requirements and the high-dimensional design space. In order to address all these challenges, an aerodynamic design optimization method is developed in this study. This method automates the design process by integrating a geometrical parameterization method, a CFD solver and numerical optimization methods that can be applied to both single and multi-point optimization design problems. A multi-level blade parameterization is employed to modify the blade geometry. Numerical analyses are performed by solving 3D RANS equations combined with SST turbulence model. Genetic algorithms and hybrid optimization methods are applied to solve the optimization problem. In order to verify the effectiveness and feasibility of the optimization method, a singlepoint optimization problem aiming to maximize design efficiency is formulated and applied to redesign a test case. However, transonic fan blade design is inherently a multi-faceted problem that deals with several objectives such as efficiency, stall margin, and choke margin. The proposed multi-point optimization method in the current study is formulated as a bi-objective problem to maximize design and near-stall efficiencies while maintaining the required design pressure ratio. Enhancing these objectives significantly deteriorate the choke margin, specifically at high rotational speeds. Therefore, another constraint is embedded in the optimization problem in order to prevent the reduction of choke margin at high speeds. Since capturing stall inception is numerically very expensive, stall margin has not been considered as an objective in the problem statement. However, improving near-stall efficiency results in a better performance at stall condition, which could enhance the stall margin. An investigation is therefore performed on the Pareto-optimal solutions to demonstrate the relation between near-stall efficiency and stall margin. The proposed method is applied to redesign NASA rotor 67 for single and multiple operating conditions. The single-point design optimization showed +0.28 points improvement of isentropic efficiency at design point, while the design pressure ratio and mass flow are, respectively, within 0.12% and 0.11% of the reference blade. Two cases of multi-point optimization are performed: First, the proposed multi-point optimization problem is relaxed by removing the choke margin constraint in order to demonstrate the relation between near-stall efficiency and stall margin. An investigation on the Pareto-optimal solutions of this optimization shows that the stall margin has been increased with improving near-stall efficiency. The second multi-point optimization case is performed with considering all the objectives and constraints. One selected optimized design on the Pareto front presents +0.41, +0.56 and +0.9 points improvement in near-peak efficiency, near-stall efficiency and stall margin, respectively. The design pressure ratio and mass flow are, respectively, within 0.3% and 0.26% of the reference blade. Moreover the optimized design maintains the required choking margin. Detailed aerodynamic analyses are performed to investigate the effect of shape optimization on shock occurrence, secondary flows, tip leakage and shock/tip-leakage interactions in both single and multi-point optimizations.

Scaling forecast models for wind turbulence and wind turbine power intermittency

NASA Astrophysics Data System (ADS)

Duran Medina, Olmo; Schmitt, Francois G.; Calif, Rudy

2017-04-01

The intermittency of the wind turbine power remains an important issue for the massive development of this renewable energy. The energy peaks injected in the electric grid produce difficulties in the energy distribution management. Hence, a correct forecast of the wind power in the short and middle term is needed due to the high unpredictability of the intermittency phenomenon. We consider a statistical approach through the analysis and characterization of stochastic fluctuations. The theoretical framework is the multifractal modelisation of wind velocity fluctuations. Here, we consider three wind turbine data where two possess a direct drive technology. Those turbines are producing energy in real exploitation conditions and allow to test our forecast models of power production at a different time horizons. Two forecast models were developed based on two physical principles observed in the wind and the power time series: the scaling properties on the one hand and the intermittency in the wind power increments on the other. The first tool is related to the intermittency through a multifractal lognormal fit of the power fluctuations. The second tool is based on an analogy of the power scaling properties with a fractional brownian motion. Indeed, an inner long-term memory is found in both time series. Both models show encouraging results since a correct tendency of the signal is respected over different time scales. Those tools are first steps to a search of efficient forecasting approaches for grid adaptation facing the wind energy fluctuations.

Multi-point laser ignition device

DOEpatents

McIntyre, Dustin L.; Woodruff, Steven D.

2017-01-17

A multi-point laser device comprising a plurality of optical pumping sources. Each optical pumping source is configured to create pumping excitation energy along a corresponding optical path directed through a high-reflectivity mirror and into substantially different locations within the laser media thereby producing atomic optical emissions at substantially different locations within the laser media and directed along a corresponding optical path of the optical pumping source. An output coupler and one or more output lenses are configured to produce a plurality of lasing events at substantially different times, locations or a combination thereof from the multiple atomic optical emissions produced at substantially different locations within the laser media. The laser media is a single continuous media, preferably grown on a single substrate.

Multipoint vibrometry with dynamic and static holograms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haist, T.; Lingel, C.; Osten, W.

2013-12-15

We report on two multipoint vibrometers with user-adjustable position of the measurement spots. Both systems are using holograms for beam deflection. The measurement is based on heterodyne interferometry with a frequency difference of 5 MHz between reference and object beam. One of the systems uses programmable positioning of the spots in the object volume but is limited concerning the light efficiency. The other system is based on static holograms in combination with mechanical adjustment of the measurement spots and does not have such a general efficiency restriction. Design considerations are given and we show measurement results for both systems. Inmore » addition, we analyze the sensitivity of the systems which is a major limitation compared to single point scanning systems.« less

Development of a Novel Two Dimensional Surface Plasmon Resonance Sensor Using Multiplied Beam Splitting Optics

PubMed Central

Hemmi, Akihide; Mizumura, Ryosuke; Kawanishi, Ryuta; Nakajima, Hizuru; Zeng, Hulie; Uchiyama, Katsumi; Kaneki, Noriaki; Imato, Toshihiko

2013-01-01

A novel two dimensional surface plasmon resonance (SPR) sensor system with a multi-point sensing region is described. The use of multiplied beam splitting optics, as a core technology, permitted multi-point sensing to be achieved. This system was capable of simultaneously measuring nine sensing points. Calibration curves for sucrose obtained on nine sensing points were linear in the range of 0–10% with a correlation factor of 0.996–0.998 with a relative standard deviation of 0.090–4.0%. The detection limits defined as S/N = 3 were 1.98 × 10−6–3.91 × 10−5 RIU. This sensitivity is comparable to that of conventional SPR sensors. PMID:23299626

Uncertainty evaluation in normalization of isotope delta measurement results against international reference materials.

PubMed

Meija, Juris; Chartrand, Michelle M G

2018-01-01

Isotope delta measurements are normalized against international reference standards. Although multi-point normalization is becoming a standard practice, the existing uncertainty evaluation practices are either undocumented or are incomplete. For multi-point normalization, we present errors-in-variables regression models for explicit accounting of the measurement uncertainty of the international standards along with the uncertainty that is attributed to their assigned values. This manuscript presents framework to account for the uncertainty that arises due to a small number of replicate measurements and discusses multi-laboratory data reduction while accounting for inevitable correlations between the laboratories due to the use of identical reference materials for calibration. Both frequentist and Bayesian methods of uncertainty analysis are discussed.

Deployment Design of Wireless Sensor Network for Simple Multi-Point Surveillance of a Moving Target

PubMed Central

Tsukamoto, Kazuya; Ueda, Hirofumi; Tamura, Hitomi; Kawahara, Kenji; Oie, Yuji

2009-01-01

In this paper, we focus on the problem of tracking a moving target in a wireless sensor network (WSN), in which the capability of each sensor is relatively limited, to construct large-scale WSNs at a reasonable cost. We first propose two simple multi-point surveillance schemes for a moving target in a WSN and demonstrate that one of the schemes can achieve high tracking probability with low power consumption. In addition, we examine the relationship between tracking probability and sensor density through simulations, and then derive an approximate expression representing the relationship. As the results, we present guidelines for sensor density, tracking probability, and the number of monitoring sensors that satisfy a variety of application demands. PMID:22412326

The Second NATO Modelling and Simulation Conference(Deuxieme conference OTAN sur la modelisation et la simulation)

DTIC Science & Technology

2001-07-01

Major General A C Figgures, Capability Manager (Manœuvre) UK MOD, provided the Conference with a fitting end message encouraging the SE and M&S...SESSION Welcoming Address - ‘Synthetic Environments - Managing the Breakout’ WA by M. Markin Opening Address for NATO M&S Conference OA by G. Sürsal...Keynote Address KN by G.J. Burrows Industry’s Role IR† by M. Mansell The RMCS SSEL I by J.R. Searle SESSION 1: POLICY, STRATEGY & MANAGEMENT A Strategy

Reduction of Military Vehicle Acquisition Time and Cost through Advanced Modelling and Virtual Simulation (La reduction des couts et des delais d’acquisition des vehicules militaires par la modelisation avancee et la simulation de produit virtuel)

DTIC Science & Technology

2003-03-01

nations, a very thorough examination of current practices. Introduction The Applied Vehicle Technology Panel (AVT) of the Research and Technology...the introduction of new information generated by computer codes required it to be timely and presented in appropriate fashion so that it could...military competition between the NATO allies and the Soviet Union. The second was the introduction of commercial, high capacity transonic aircraft and

Models for Aircrew Safety Assessment: Uses, Limitations and Requirements (la Modelisation des conditions de securite des equipages: applications, limitations et cahiers des charges)

DTIC Science & Technology

1999-08-01

immediately, re- ducing venous return artifacts during the first beat of the simulation. tn+1 - W+ on c+ / \\ W_ on c_ t 1 Xi-l Xi+1 Figure 4...s) Figure 5: The effect of network complexity. The aortic pressure is shown in Figure 5 during the fifth beat for the networks with one and three...Mechanical Engineering Department, Uni- versity of Victoria. [19] Huyghe J.M., 1986, "Nonlinear Finite Element Models of The Beating Left

Modelling and Simulation as a Service: New Concepts and Service-Oriented Architectures (Modelisation et simulation en tant que service: Nouveaux concepts et architectures orientes service)

DTIC Science & Technology

2015-05-01

delivery business model where S&T activities are conducted in a NATO dedicated executive body, having its own personnel, capabilities and infrastructure ...SD-4: Design for Securability 5-4 5.3.2 Recommendations on Simulation Environment Infrastructure 5-5 5.3.2.1 Recommendation IN-1: Harmonize...Critical Data and 5-5 Algorithms 5.3.2.2 Recommendation IN-2: Establish Permanent Simulation 5-5 Infrastructure 5.3.2.3 Recommendation IN-3: Establish

Modelling of Molecular Structures and Properties in Physical Chemistry and Biophysics, Forty-Fourth International Meeting (Modelisation des Structures et Proprietes Moleculaires en Chimie Physique et en Biophysique, Quarante- Quatrieme Reunion Internationale)

DTIC Science & Technology

1989-09-01

pyridone).Previous work on, py/ridimum, pyrazinjumn or pyrimidi im salts Koon 2 -pyrimloone and 2 - pyrimidone salts [43j have shown that some...forces. Acct . r ~[U... •K;.i. LJ , ’ 0, ’’ .t_I ..- .It . ( :.. 2 A VIBRATIONAL MOLECULAR FORCE FIELD FOR .ACROMOLECULA-R MODELLI= Gerard VERGOTENi...microscopic point of view are (1) understanding, ( 2 ) interpretation of experimental results, (3) semiquantitative estimates of experimental results and (4

Propagation Modelling and Decision Aids for Communications, Radar and Navigation Systems (La Modelisation de la Propagation et Aides a la Decision Pour les Sysemes de elecommunicaions, de Radar et de Navigation)

DTIC Science & Technology

1994-09-01

the refractive index i. can be density, temperature , ion composition, ionospheric determined from a simplified form of the Appleton- electric field...see Cannon 119941. the electron density profile is based upon the underlying neutral composition. temperature and wind together with electric field...in many of the newer HF predictions decision software , NSSDC/WDC-A-R&S 90-19, National Space aids. They also provide a very useful stand alone

A multiobjective hybrid genetic algorithm for the capacitated multipoint network design problem.

PubMed

Lo, C C; Chang, W H

2000-01-01

The capacitated multipoint network design problem (CMNDP) is NP-complete. In this paper, a hybrid genetic algorithm for CMNDP is proposed. The multiobjective hybrid genetic algorithm (MOHGA) differs from other genetic algorithms (GAs) mainly in its selection procedure. The concept of subpopulation is used in MOHGA. Four subpopulations are generated according to the elitism reservation strategy, the shifting Prufer vector, the stochastic universal sampling, and the complete random method, respectively. Mixing these four subpopulations produces the next generation population. The MOHGA can effectively search the feasible solution space due to population diversity. The MOHGA has been applied to CMNDP. By examining computational and analytical results, we notice that the MOHGA can find most nondominated solutions and is much more effective and efficient than other multiobjective GAs.

AVST Morphing Project Research Summaries in Fiscal Year 2001

NASA Technical Reports Server (NTRS)

McGowan, Anna-Maria R.

2002-01-01

The Morphing project at the National Aeronautics and Space Agency's Langley Research Center is part of the Aerospace Vehicle Systems Program Office that conducts fundamental research on advanced technologies for future flight vehicles. The objectives of the Morphing project are to develop and assess advanced technologies and integrated component concepts to enable efficient, multi-point adaptability in air and space vehicles. In the context of the project, the word "morphing" is defined as "efficient, multi-point adaptability" and may include micro or macro, structural or fluidic approaches. The current document on the Morphing project is a compilation of research summaries and other information on the project from fiscal year 2001. The focus of this document is to provide a brief overview of the project content, technical results and lessons learned from fiscal year 2001.

Immobilization and stabilization of pectinase by multipoint attachment onto an activated agar-gel support.

PubMed

Li, Tuoping; Li, Suhong; Wang, Na; Tain, Lirui

2008-08-15

Pectinase was immobilized on an activated agar-gel support by multipoint attachment. The maximal activity of immobilized pectinase was obtained at 5°C, pH 3.6, with a 24h reaction time at an enzyme dose of 0.52mg protein/g gel, and the gel was activated with 1.0M glycidol. These conditions increased the thermal stability of the immobilized pectinase 19-fold compared with the free enzyme at 65°C. The optimal temperature for pectinase activity changed from 40 to 50°C after immobilization; however, the optimal pH remained unchanged. The immobilized enzyme also exhibited great operational stability, and an 81% residual activity was observed in the immobilized enzyme after 10 batch reactions. Copyright © 2008 Elsevier Ltd. All rights reserved.

47 CFR 101.1005 - Frequencies available.

Code of Federal Regulations, 2011 CFR

2011-10-01

... FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1005 Frequencies available. (a) The... is shared with private microwave point-to-point systems licensed prior to March 11, 1997, as provided...

47 CFR 101.1005 - Frequencies available.

Code of Federal Regulations, 2014 CFR

2014-10-01

... FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1005 Frequencies available. (a) The... is shared with private microwave point-to-point systems licensed prior to March 11, 1997, as provided...

47 CFR 101.1005 - Frequencies available.

Code of Federal Regulations, 2010 CFR

2010-10-01

... FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1005 Frequencies available. (a) The... is shared with private microwave point-to-point systems licensed prior to March 11, 1997, as provided...

47 CFR 101.1005 - Frequencies available.

Code of Federal Regulations, 2013 CFR

2013-10-01

... FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1005 Frequencies available. (a) The... is shared with private microwave point-to-point systems licensed prior to March 11, 1997, as provided...

47 CFR 101.1005 - Frequencies available.

Code of Federal Regulations, 2012 CFR

2012-10-01

... FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1005 Frequencies available. (a) The... is shared with private microwave point-to-point systems licensed prior to March 11, 1997, as provided...

Veff Scaling of Te and ne Measurements During Local Helicity Injection on the Pegasus Toroidal Experiment

NASA Astrophysics Data System (ADS)

Bodner, G. M.; Bongard, M. W.; Fonck, R. J.; Perry, J. M.; Reusch, J. A.; Rodriguez Sanchez, C.

2017-10-01

Understanding the electron confinement of local helicity injection (LHI) is critical in order to evaluate its scalability as a startup technique to MA-class devices. Electron confinement in the Pegasus Toroidal Experiment is investigated using multi-point Thomson scattering (TS). The Pegasus TS system utilizes a set of high-throughput transmission gratings and intensified CCDs to measure Te and ne profiles. Previous TS measurements indicated peaked Te profiles 120 eV in outboard injector discharges characterized by strong inductive drive and low LHI drive. Injectors designed to have dominant non-inductive drive have recently been installed in the divertor region of Pegasus to understand the relationship between effective drive voltage, Veff, and plasma performance. At low Veff and reduced plasma current, Ip 60 kA, TS measurements reveal a flat Te profile 50 eV, with a peaked ne profile 1 ×1019 m-3, resulting in a slightly peaked pe profile. As current drive is increased, the Te profiles become hollow with a core Te 50 eV and an edge Te 120 -150 eV. These hollow profiles appear after the start of the Ip flattop and are sustained until the discharge terminates. The ne profiles drop in magnitude to < 1 ×1019 m-3 but remain somewhat peaked. Initial results suggest a weak scaling between input power and core Te. Additional studies are planned to identify the mechanisms behind the anomalous profile features. Work supported by US DOE Grant DE-FG02-96ER54375.

Capability 9.2 Mobility

NASA Technical Reports Server (NTRS)

Zakrasjek, June

2005-01-01

Modern operational concepts require significant bandwidths and multipoint communication capabilities. Provide voice, video and data communications among vehicles moving along the surface, vehicles in suborbital transport or reconnaissance, surface elements, and home planet facilities.

Multipoint NIR spectroscopy for gross composition analysis of powdered infant formula under various motion conditions.

PubMed

Cama-Moncunill, Raquel; Markiewicz-Keszycka, Maria; Dixit, Yash; Cama-Moncunill, Xavier; Casado-Gavalda, Maria P; Cullen, Patrick J; Sullivan, Carl

2016-07-01

Powdered infant formula (PIF) is a worldwide, industrially produced, human milk substitute. Manufacture of PIF faces strict quality controls in order to ensure that the product meets all compositional requirements. Near-infrared (NIR) spectroscopy is a rapid, non-destructive and well-qualified technique for food quality assessments. The use of fibre-optic NIR sensors allows measuring in-line and at real-time, and can record spectra from different stages of the process. The non-contact character of fibre-optic sensors can be enhanced by fitting collimators, which allow operation at various distances. The system, based on a Fabry-Perot interferometer, records four spectra concurrently, rather than consecutively as in the "quasi-simultaneous" multipoint NIR systems. In the present study, a novel multipoint NIR spectroscopy system equipped with four fibre-optic probes with collimators was assessed to determine carbohydrate and protein contents of PIF samples under static and motion conditions (0.02, 0.15 and 0.30m/s) to simulate possible industrial scenarios. Best results were obtained under static conditions providing a R(2) of calibration of 0.95 and RMSEP values of 1.89%. Yet, considerably low values of RMSEP, for instance 2.70% at 0.15m/s, were provided with the in-motion predictions, demonstrating the system's potential for in/on-line applications at various levels of speed. The current work also evaluated the viability of using general off-line calibrations developed under static conditions for on/in-line applications subject to motion. To this end, calibrations in both modes were developed and compared. Best results were obtained with specific calibrations; however, reasonably accurate models were obtained with the general calibration. Furthermore, this work illustrated independency of the collimator-probe setup by characterizing PIF samples simultaneously recorded according to their carbohydrate content, even when measured under different conditions. Therefore, the improved multipoint NIR approach constitutes a potential in/on-line tool for quality evaluation of PIF over the manufacturing process. Copyright © 2016 Elsevier B.V. All rights reserved.

47 CFR 101.139 - Authorization of transmitters.

Code of Federal Regulations, 2013 CFR

2013-10-01

... SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.139 Authorization of transmitters. (a) Unless...-point microwave and point-to-multipoint services under this part must be a type that has been verified...

47 CFR 101.139 - Authorization of transmitters.

Code of Federal Regulations, 2014 CFR

2014-10-01

... SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.139 Authorization of transmitters. (a) Unless...-point microwave and point-to-multipoint services under this part must be a type that has been verified...

47 CFR 101.139 - Authorization of transmitters.

Code of Federal Regulations, 2012 CFR

2012-10-01

... SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.139 Authorization of transmitters. (a) Unless...-point microwave and point-to-multipoint services under this part must be a type that has been verified...

47 CFR 101.139 - Authorization of transmitters.

Code of Federal Regulations, 2011 CFR

2011-10-01

... SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101.139 Authorization of transmitters. (a) Unless...-point microwave and point-to-multipoint services under this part must be a type that has been verified...

New Options for AV in Telecommunications

ERIC Educational Resources Information Center

Gelman, Morrie

1974-01-01

A discussion of MDS, a multi-point distribution service which is a recently evolved supplementary telecommunications service that suggests new possibilities for improving the reach, impact and effectiveness of audio-visual communications. (Author)

Alternative licensing arrangements and spectrum economics: The case of multipoint distribution service

NASA Technical Reports Server (NTRS)

Agnew, C. E.

1981-01-01

At present, the Federal Communications Commission assigns radio licenses following a determination of the public interest. Whenever mutually conflicting license applications are filed, the Commission holds a comparative hearing. This assignment mechanism is criticized as cumbersome and unrealiable, and three alternatives are proposed: increasing the available spectrum, and either auctions or lotteries of radio licenses. An analysis is presented of the present system and these alternative arrangments for assigning rights to the frequency spectrum for the Multipoint Distribution Service (MDS). Although MDS is a relatively minor radio service, it serves as a prototype for message distribution services with a large potential for use in business communications. Moreover, the way in which the initial batch of MDS licenses was assigned provides a unique opportunity for empirical work on the economics of the licensing process.

Integrated photonics for fiber optic based temperature sensing

NASA Astrophysics Data System (ADS)

Evenblij, R. S.; van Leest, T.; Haverdings, M. B.

2017-09-01

One of the promising space applications areas for fibre sensing is high reliable thermal mapping of metrology structures for effects as thermal deformation, focal plane distortion, etc. Subsequently, multi-point temperature sensing capability for payload panels and instrumentation instead of, or in addition to conventional thermo-couple technology will drastically reduce electrical wiring and sensor materials to minimize weight and costs. Current fiber sensing technologies based on solid state ASPIC (Application Specific Photonic Integrated Circuits) technology, allow significant miniaturization of instrumentation and improved reliability. These imperative aspects make the technology candidate for applications in harsh environments such as space. One of the major aspects in order to mature ASPIC technology for space is assessment on radiation hardness. This paper describes the results of radiation hardness experiments on ASPIC including typical multipoint temperature sensing and thermal mapping capabilities.

Research on the Wire Network Signal Prediction Based on the Improved NNARX Model

NASA Astrophysics Data System (ADS)

Zhang, Zipeng; Fan, Tao; Wang, Shuqing

It is difficult to obtain accurately the wire net signal of power system's high voltage power transmission lines in the process of monitoring and repairing. In order to solve this problem, the signal measured in remote substation or laboratory is employed to make multipoint prediction to gain the needed data. But, the obtained power grid frequency signal is delay. In order to solve the problem, an improved NNARX network which can predict frequency signal based on multi-point data collected by remote substation PMU is describes in this paper. As the error curved surface of the NNARX network is more complicated, this paper uses L-M algorithm to train the network. The result of the simulation shows that the NNARX network has preferable predication performance which provides accurate real time data for field testing and maintenance.

Approaching Solar Maximum 24 with Stereo-Multipoint Observations of Solar Energetic Particle Events

NASA Technical Reports Server (NTRS)

Dresing, N.; Cohen, C. M. S.; Gomez-Herrero, R.; Heber, B.; Klassen, A.; Leske, R. A.; Mason, G. M.; Mewaldt, R. A.; von Rosenvinge, T. T.

2014-01-01

Since the beginning of the Solar Terrestrial Relations Observatory (STEREO) mission at the end of 2006, the two spacecraft have now separated by more than 130? degrees from the Earth. A 360-degree view of the Sun has been possible since February 2011, providing multipoint in situ and remote sensing observations of unprecedented quality. Combining STEREO observations with near-Earth measurements allows the study of solar energetic particle (SEP) events over a wide longitudinal range with minimal radial gradient effects. This contribution provides an overview of recent results obtained by the STEREO/IMPACT team in combination with observations by the ACE and SOHO spacecraft. We focus especially on multi-spacecraft investigations of SEP events. The large longitudinal spread of electron and 3He-rich events as well as unusual anisotropies will be presented and discussed.

Searching susceptibility loci for bipolar disorder: a sib pair study on chromosome 12.

PubMed

Lorenzi, Cristina; Delmonte, Dario; Pirovano, Adele; Marino, Elena; Bongiorno, Fanny; Catalano, Marco; Colombo, Cristina; Bramanti, Placido; Smeraldi, Enrico

2010-01-01

Several linkage studies demonstrated that different chromosomal regions are involved in the susceptibility to bipolar disorder. In particular, some genome scans evidenced the role of chromosome 12. For this reason, our group chose this chromosome for a preliminary genome scan on a sample of 137 Italian sib pairs, including at least 1 bipolar subject. The analyses were carried out by means of DNA extracted from whole blood. DNA samples were genotyped by 19 simple tandem repeat markers (microsatellites). Starting from the genetic data, we performed two- and multipoint linkage analyses (both parametric and nonparametric) by means of Easy Linkage plus package (version 5.05). The multipoint linkage analyses pointed out a region suggestive of linkage between the markers D12S310 and D12S364, at locus 12p12. In particular, we reached the best evidence of linkage performing multipoint analyses and assuming a recessive model, under the hypothesis of genetic heterogeneity (heterogeneity LOD score = 2.01 and alpha = 0.77). It is interesting to notice that the region at the marker D12S364 is located inside the gene coding for the glutamatergic receptor GRIN2B. Therefore, our finding not only confirmed the role of genetics in determining liability to bipolar disorder, but suggested glutamatergic transmission impairment as a possible cause. Nevertheless, we acknowledge that our study is heavily underpowered. Therefore, independent replication is needed. (c) 2009 S. Karger AG, Basel.

Sequential multipoint motion of the tympanic membrane measured by laser Doppler vibrometry: preliminary results for normal tympanic membrane.

PubMed

Kunimoto, Yasuomi; Hasegawa, Kensaku; Arii, Shiro; Kataoka, Hideyuki; Yazama, Hiroaki; Kuya, Junko; Kitano, Hiroya

2014-04-01

Numerous studies have reported sound-induced motion of the tympanic membrane (TM). To demonstrate sequential motion characteristics of the entire TM by noncontact laser Doppler vibrometry (LDV), we have investigated multipoint TM measurement. A laser Doppler vibrometer was mounted on a surgical microscope. The velocity was measured at 33 points on the TM using noncontact LDV without any reflectors. Measurements were performed with tonal stimuli of 1, 3, and 6 kHz. Amplitudes were calculated from these measurements, and time-dependent changes in TM motion were described using a graphics application. TM motions were detected more clearly and stably at 1 and 3 kHz than at other frequencies. This is because the external auditory canal acted as a resonant tube near 3 kHz. TM motion displayed 1 peak at 1 kHz and 2 peaks at 3 kHz. Large amplitudes were detected in the posterosuperior quadrant (PSQ) at 1 kHz and in the PSQ and anteroinferior quadrant (AIQ) at 3 kHz. The entire TM showed synchronized movement centered on the PSQ at 1 kHz, with phase-shifting between PSQ and AIQ movement at 3 kHz. Amplitude was smaller at the umbo than at other parts. In contrast, amplitudes at high frequencies were too small and complicated to detect any obvious peaks. Sequential multipoint motion of the tympanic membrane showed that vibration characteristics of the TM differ according to the part and frequency.

Low-cost fused taper polymer optical fiber (LFT-POF) splitters for environmental and home-networking solution

NASA Astrophysics Data System (ADS)

Supian, L. S.; Ab-Rahman, Mohammad Syuhaimi; Harun, Mohd Hazwan; Gunab, Hadi; Sulaiman, Malik; Naim, Nani Fadzlina

2017-08-01

In visible optical communication over the multimode PMMA fibers, the overall cost of optical network can be reduced by deploying economical splitters for distributing the optical data signals from a point to multipoint in transmission network. The low-cost splitters shall have two main characteristics; good uniformity and high power efficiency. The most cost-effective and environmental friendly optical splitter having those characteristics have been developed. The device material is 100% purely based on the multimode step-index PMMA Polymer Optical Fiber (POF). The region which all fibers merged as single fiber is called as fused-taper POF. This ensures that all fibers are melted and fused properly. The results for uniformity and power efficiency of all splitters have been revealed by injecting red LED transmitter with 650 nm wavelength into input port while each end of output fibers measured by optical power meter. Final analysis shows our fused-taper splitter has low excess loss 0.53 dB and each of the output port has low insertion loss, which the average value is below 7 dB. In addition, the splitter has good uniformity that is 32:37:31% in which it is suitably used for demultiplexer fabrication.

A comparison of exhaust emissions from vehicles fuelled with petrol, LPG and CNG

NASA Astrophysics Data System (ADS)

Bielaczyc, P.; Szczotka, A.; Woodburn, J.

2016-09-01

This paper presents an analysis of THC, NMHC, CO, NOx and CO2 emissions during testing of two bi-fuel vehicles, fuelled with petrol and gaseous fuels, on a chassis dynamometer in the context of the Euro 6 emissions requirements. The analyses were performed on one Euro 5 bi-fuel vehicle (petrol/LPG) and one Euro 5 bi-fuel vehicle (petrol/CNG), both with SI engines equipped with MPI feeding systems operating in closed-loop control, typical three-way-catalysts and heated oxygen sensors. The vehicles had been adapted by their manufacturers for fuelling with LPG or CNG by using additional special equipment mounted onto the existing petrol fuelling system. The vehicles tested featured multipoint gas injection systems. The aim of this paper was an analysis of the impact of the gaseous fuels on the exhaust emission in comparison to the emission of the vehicles fuelled with petrol. The tests subject to the analyses presented here were performed in the Engine Research Department of BOSMAL Automotive Research and Development Institute Ltd in Bielsko-Biala, Poland, within a research programme investigating the influence of alternative fuels on exhaust emissions from light duty vehicle vehicles with spark-ignition and compression-ignition engines.

A new approach to tracer transport analysis: From fracture systems to strongly heterogeneous porous media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsang, Chin-Fu

Many current development and utilization of groundwater resources include a study of their flow and transport properties. These properties are needed in evaluating possible changes in groundwater quality and potential transport of hazardous solutes through the groundwater system. Investigation of transport properties of fractured rocks is an active area of research. Most of the current approaches to the study of flow and transport in fractured rocks cannot be easily used for analysis of tracer transport field data. A new approach is proposed based on a detailed study of transport through a fracture of variable aperture. This is a two-dimensional stronglymore » heterogeneous permeable system. It is suggested that tracer breakthrough curves can be analyzed based on an aperture or permeability probability distribution function that characterizes the tracer flow through the fracture. The results are extended to a multi-fracture system and can be equally applied to a strongly heterogeneous porous medium. Finally, the need for multi-point or line and areal tracer injection and observation tests is indicated as a way to avoid the sensitive dependence of point measurements on local permeability variability. 30 refs., 15 figs.« less

Radio Wave Propagation Modeling, Prediction and Assessment (L’Evaluation, la Prevision et la Modelisation des Ondes Hertziennes)

DTIC Science & Technology

1990-01-01

modifiers and added an additional set of modifiers to adjust the average VTOP. The original DECO model made use of waveguide excitation factors and...ranges far beyond the horizon. The modified refractivity M is defined by N - N + (h/a) x 106 - N + 0.157 h (2.1) where h is the height above the earth’s...LAYEIR APPING LAVER REFRACTIVITY N MODIFIED REFRAACTIVIT M Figure 2.4. N and N profiles for an elevated duct. t /VA--’’TM tDUCT ITx IFPAT4G RELRACIVT

Modelisation and distribution of neutron flux in radium-beryllium source (226Ra-Be)

NASA Astrophysics Data System (ADS)

Didi, Abdessamad; Dadouch, Ahmed; Jai, Otman

2017-09-01

Using the Monte Carlo N-Particle code (MCNP-6), to analyze the thermal, epithermal and fast neutron fluxes, of 3 millicuries of radium-beryllium, for determine the qualitative and quantitative of many materials, using method of neutron activation analysis. Radium-beryllium source of neutron is established to practical work and research in nuclear field. The main objective of this work was to enable us harness the profile flux of radium-beryllium irradiation, this theoretical study permits to discuss the design of the optimal irradiation and performance for increased the facility research and education of nuclear physics.

Guide to Modelling & Simulation (M&S) for NATO Network-Enabled Capability (M&S for NNEC) (Guide de la modelisation et de la simulation (M&S) pour las NATO network-enabled capability (M&S de la NNEC))

DTIC Science & Technology

2010-02-01

interdependencies, and then modifying plans according to updated projections. This is currently an immature area where further research is required. The...crosscutting.html. [7] Zeigler, B.P. and Hammonds, P. (2007). “Modelling and Simulation- Based Data Engineering: Introducing Pragmatics and Ontologies for...the optimum benefit to be obtained and while immature , ongoing research needs to be maintained. 20) Use of M&S to support complex operations needs

Etude thermo-hydraulique de l'ecoulement du moderateur dans le reacteur CANDU-6

NASA Astrophysics Data System (ADS)

Mehdi Zadeh, Foad

Etant donne la taille (6,0 m x 7,6 m) ainsi que le domaine multiplement connexe qui caracterisent la cuve des reacteurs CANDU-6 (380 canaux dans la cuve), la physique qui gouverne le comportement du fluide moderateur est encore mal connue de nos jours. L'echantillonnage de donnees dans un reacteur en fonction necessite d'apporter des changements a la configuration de la cuve du reacteur afin d'y inserer des sondes. De plus, la presence d'une zone intense de radiations empeche l'utilisation des capteurs courants d'echantillonnage. En consequence, l'ecoulement du moderateur doit necessairement etre etudie a l'aide d'un modele experimental ou d'un modele numerique. Pour ce qui est du modele experimental, la fabrication et la mise en fonction de telles installations coutent tres cher. De plus, les parametres de la mise a l'echelle du systeme pour fabriquer un modele experimental a l'echelle reduite sont en contradiction. En consequence, la modelisation numerique reste une alternative importante. Actuellement, l'industrie nucleaire utilise une approche numerique, dite de milieu poreux, qui approxime le domaine par un milieu continu ou le reseau des tubes est remplace par des resistances hydrauliques distribuees. Ce modele est capable de decrire les phenomenes macroscopiques de l'ecoulement, mais ne tient pas compte des effets locaux ayant un impact sur l'ecoulement global, tel que les distributions de temperatures et de vitesses a proximite des tubes ainsi que des instabilites hydrodynamiques. Dans le contexte de la surete nucleaire, on s'interesse aux effets locaux autour des tubes de calandre. En effet, des simulations faites par cette approche predisent que l'ecoulement peut prendre plusieurs configurations hydrodynamiques dont, pour certaines, l'ecoulement montre un comportement asymetrique au sein de la cuve. Ceci peut provoquer une ebullition du moderateur sur la paroi des canaux. Dans de telles conditions, le coefficient de reactivite peut varier de maniere importante, se traduisant par l'accroissement de la puissance du reacteur. Ceci peut avoir des consequences majeures pour la surete nucleaire. Une modelisation CFD (Computational Fluid Dynamics) detaillee tenant compte des effets locaux s'avere donc necessaire. Le but de ce travail de recherche est de modeliser le comportement complexe de l'ecoulement du moderateur au sein de la cuve d'un reacteur nucleaire CANDU-6, notamment a proximite des tubes de calandre. Ces simulations servent a identifier les configurations possibles de l'ecoulement dans la calandre. Cette etude consiste ainsi a formuler des bases theoriques a l'origine des instabilites macroscopiques du moderateur, c.-a-d. des mouvements asymetriques qui peuvent provoquer l'ebullition du moderateur. Le defi du projet est de determiner l'impact de ces configurations de l'ecoulement sur la reactivite du reacteur CANDU-6.

Synchronization of Multipoint Hoists

DTIC Science & Technology

A contractor has conceived an electrohydraulic feedback system that will provide position synchronization of four aircraft cargo hoists. To... synchronized hoist system. Test results show that the feedback system concept provides adequate synchronization control; i.e., the platform pitch and roll

Comparison of modal test results - Multipoint sine versus single-point random. [for Mariner Jupiter/Saturn spacecraft

NASA Technical Reports Server (NTRS)

Leppert, E. L.; Lee, S. H.; Day, F. D.; Chapman, P. C.; Wada, B. K.

1976-01-01

The Mariner Jupiter/Saturn (MJS) spacecraft was subjected to the traditional multipoint sine dwell (MPSD) modal test using 111 accelerometer channels, and also to single-point random (SPR) testing using 26 accelerometer channels, and the two methods are compared according to cost, schedule, and technical criteria. A measure of comparison between the systems was devised in terms of the cumulative difference in the kinetic energy distribution of the common accelerometers. The SPR and MPSD method show acceptable agreement with respect to frequencies and mode damping. The merit of the SPR method is that the excitation points are minimized and the test article can be committed to other uses while data analysis is performed. The MPSD approach allows validity of the data to be determined as the test progresses. Costs are about the same for the two methods.

A Standard-Compliant Virtual Meeting System with Active Video Object Tracking

NASA Astrophysics Data System (ADS)

Lin, Chia-Wen; Chang, Yao-Jen; Wang, Chih-Ming; Chen, Yung-Chang; Sun, Ming-Ting

2002-12-01

This paper presents an H.323 standard compliant virtual video conferencing system. The proposed system not only serves as a multipoint control unit (MCU) for multipoint connection but also provides a gateway function between the H.323 LAN (local-area network) and the H.324 WAN (wide-area network) users. The proposed virtual video conferencing system provides user-friendly object compositing and manipulation features including 2D video object scaling, repositioning, rotation, and dynamic bit-allocation in a 3D virtual environment. A reliable, and accurate scheme based on background image mosaics is proposed for real-time extracting and tracking foreground video objects from the video captured with an active camera. Chroma-key insertion is used to facilitate video objects extraction and manipulation. We have implemented a prototype of the virtual conference system with an integrated graphical user interface to demonstrate the feasibility of the proposed methods.

A small spacecraft for multipoint measurement of ionospheric plasma.

PubMed

Roberts, T M; Lynch, K A; Clayton, R E; Weiss, J; Hampton, D L

2017-07-01

Measurement of ionospheric plasma is often performed by a single in situ device or remotely using cameras and radar. This article describes a small, low-resource, deployed spacecraft used as part of a local, multipoint measurement network. A B-field aligned sounding rocket ejects four of these spin-stabilized spacecraft in a cross pattern. In this application, each spacecraft carries two retarding potential analyzers which are used to determine plasma density, flow, and ion temperature. An inertial measurement unit and a light-emitting diode array are used to determine the position and orientation of the devices after deployment. The design of this spacecraft is first described, and then results from a recent test flight are discussed. This flight demonstrated the successful operation of the deployment mechanism and telemetry systems, provided some preliminary plasma measurements in a simple mid-latitude environment, and revealed several design issues.

A small spacecraft for multipoint measurement of ionospheric plasma

NASA Astrophysics Data System (ADS)

Roberts, T. M.; Lynch, K. A.; Clayton, R. E.; Weiss, J.; Hampton, D. L.

2017-07-01

Measurement of ionospheric plasma is often performed by a single in situ device or remotely using cameras and radar. This article describes a small, low-resource, deployed spacecraft used as part of a local, multipoint measurement network. A B-field aligned sounding rocket ejects four of these spin-stabilized spacecraft in a cross pattern. In this application, each spacecraft carries two retarding potential analyzers which are used to determine plasma density, flow, and ion temperature. An inertial measurement unit and a light-emitting diode array are used to determine the position and orientation of the devices after deployment. The design of this spacecraft is first described, and then results from a recent test flight are discussed. This flight demonstrated the successful operation of the deployment mechanism and telemetry systems, provided some preliminary plasma measurements in a simple mid-latitude environment, and revealed several design issues.

Fabrication of Multi-point Side-Firing Optical Fiber by Laser Micro-ablation

PubMed Central

Nguyen, Hoang; Arnob, Md Masud Parvez; Becker, Aaron T; Wolfe, John C; Hogan, Matthew K; Horner, Philip J; Shih, Wei-Chuan

2018-01-01

A multi-point, side-firing design enables an optical fiber to output light at multiple desired locations along the fiber body. This provides advantages over traditional end-to-end fibers, especially in applications requiring fiber bundles such as brain stimulation or remote sensing. This paper demonstrates that continuous wave (CW) laser micro-ablation can controllably create conical-shaped cavities, or side windows, for outputting light. The dimensions of these cavities determine the amount of firing light and their firing angle. Experimental data show that a single side window on a 730 μm fiber can deliver more than 8 % of the input light. This was increased to more than 19 % on a 65 μm fiber with side windows created using femtosecond (fs) laser ablation and chemical etching. Fine control of light distribution along an optical fiber is critical for various biomedical applications such as light activated drug-release and optogenetics studies. PMID:28454166

A DNA Tracer System for Hydrological Environment Investigations.

PubMed

Liao, Renkuan; Yang, Peiling; Wu, Wenyong; Luo, Dan; Yang, Dayong

2018-02-20

To monitor and manage hydrological pollution effectively, tracing sources of pollutants is of great importance and also is in urgent need. A variety of tracers have been developed such as isotopes, silica, bromide, and dyes; however, practical limitations of these traditional tracers still exist such as lack of multiplexed, multipoint tracing and interference of background noise. To overcome these limitations, a new tracing system based on DNA nanomaterials, namely DNA tracer, has already been developed. DNA tracers possess remarkable advantages including sufficient species, specificity, environmental friendly, stable migration, and high sensitivity as well as allowing for multipoints tracing. In this review article, we introduce the molecular design, synthesis, protection and signal readout strategies of DNA tracers, compare the advantages and disadvantages of DNA tracer with traditional tracers, and summarize the-state-of-art applications in hydrological environment investigations. In the end, we provide our perspective on the future development of DNA tracers.

Amplified OTDR systems for multipoint corrosion monitoring.

PubMed

Nascimento, Jehan F; Silva, Marcionilo J; Coêlho, Isnaldo J S; Cipriano, Eliel; Martins-Filho, Joaquim F

2012-01-01

We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR) technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations.

Amplified OTDR Systems for Multipoint Corrosion Monitoring

PubMed Central

Nascimento, Jehan F.; Silva, Marcionilo J.; Coêlho, Isnaldo J. S.; Cipriano, Eliel; Martins-Filho, Joaquim F.

2012-01-01

We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR) technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations. PMID:22737017

Quantum coordinated multi-point communication based on entanglement swapping

NASA Astrophysics Data System (ADS)

Du, Gang; Shang, Tao; Liu, Jian-wei

2017-05-01

In a quantum network, adjacent nodes can communicate with each other point to point by using pre-shared Einsten-Podolsky-Rosen (EPR) pairs, and furthermore remote nodes can establish entanglement channels by using quantum routing among intermediate nodes. However, with the rapid development of quantum networks, the demand of various message transmission among nodes inevitably emerges. In order to realize this goal and extend quantum networks, we propose a quantum coordinated multi-point communication scheme based on entanglement swapping. The scheme takes full advantage of EPR pairs between adjacent nodes and performs multi-party entanglement swapping to transmit messages. Considering various demands of communication, all nodes work cooperatively to realize different message transmission modes, including one to many, many to one and one to some. Scheme analysis shows that the proposed scheme can flexibly organize a coordinated group and efficiently use EPR resources, while it meets basic security requirement under the condition of coordinated communication.

Two-wavelength quadrature multipoint detection of partial discharge in power transformers using fiber Fabry-Perot acoustic sensors

NASA Astrophysics Data System (ADS)

Dong, Bo; Han, Ming; Wang, Anbo

2012-06-01

A reliable and low-cost two-wavelength quadrature interrogating method has been developed to demodulate optical signals from diaphragm-based Fabry-Perot interferometric fiber optic sensors for multipoint partial discharge detection in power transformers. Commercial available fused-silica parts (a wafer, a fiber ferrule, and a mating sleeve) and a cleaved optical single mode fiber were bonded together to form an extrinsic Fabry-Perot acoustic sensor. Two lasers with center wavelengths separated by a quarter of the period of sensor interference fringes were used to probe acousticwave- induced diaphragm vibration. A coarse wavelength-division multiplexing (CWDM) add/drop multiplexer was used to separate the reflected two wavelengths before two photo detectors. Optical couplers were used to distribute mixed laser light to each sensor-detector module for multiplexing purpose. Sensor structure, detection system design and experiment results are presented.

Cryogenic-temperature profiling of high-power superconducting lines using local and distributed optical-fiber sensors.

PubMed

Chiuchiolo, Antonella; Palmieri, Luca; Consales, Marco; Giordano, Michele; Borriello, Anna; Bajas, Hugues; Galtarossa, Andrea; Bajko, Marta; Cusano, Andrea

2015-10-01

This contribution presents distributed and multipoint fiber-optic monitoring of cryogenic temperatures along a superconducting power transmission line down to 30 K and over 20 m distance. Multipoint measurements were conducted using fiber Bragg gratings sensors coated with two different functional overlays (epoxy and poly methyl methacrylate (PMMA)) demonstrating cryogenic operation in the range 300-4.2 K. Distributed measurements exploited optical frequency-domain reflectometry to analyze the Rayleigh scattering along two concatenated fibers with different coatings (acrylate and polyimide). The integrated system has been placed along the 20 m long cryostat of a superconducting power transmission line, which is currently being tested at the European Organization for Nuclear Research (CERN). Cool-down events from 300-30 K have been successfully measured in space and time, confirming the viability of these approaches to the monitoring of cryogenic temperatures along a superconducting transmission line.

Graviton multipoint amplitudes for higher-derivative gravity in anti-de Sitter space

NASA Astrophysics Data System (ADS)

Shawa, M. M. W.; Medved, A. J. M.

2018-04-01

We calculate graviton multipoint amplitudes in an anti-de Sitter black brane background for higher-derivative gravity of arbitrary order in numbers of derivatives. The calculations are performed using tensor graviton modes in a particular regime of comparatively high energies and large scattering angles. The regime simplifies the calculations but, at the same time, is well suited for translating these results into the language of the dually related gauge theory. After considering theories whose Lagrangians consist of contractions of up to four Riemann tensors, we generalize to even higher-derivative theories by constructing a "basis" for the relevant scattering amplitudes. This construction enables one to find the basic form of the n -point amplitude for arbitrary n and any number of derivatives. Additionally, using the four-point amplitudes for theories whose Lagrangians carry contractions of either three or four Riemann tensors, we reexpress the scattering properties in terms of the Mandelstam variables.

Multipoint connectivity analysis of the May 2007 solar energetic particle events

NASA Astrophysics Data System (ADS)

Chollet, E. E.; Mewaldt, R. A.; Cummings, A. C.; Gosling, J. T.; Haggerty, D. K.; Hu, Q.; Larson, D.; Lavraud, B.; Leske, R. A.; Opitz, A.; Roelof, E. C.; Russell, C. T.; Sauvaud, J.-A.

2010-12-01

In May of 2007, the STEREO Ahead and Behind spacecraft, along with the ACE spacecraft situated between the two STEREO spacecraft, observed two small solar energetic particle (SEP) events. STEREO-A and -B observed nearly identical time profiles in the 19 May event, but in the 23 May event, the protons arrived significantly earlier at STEREO-A than at STEREO-B and the time-intensity profiles were markedly different. We present SEP anisotropy, suprathermal electron pitch angle and solar wind data to demonstrate distortion in the magnetic field topology produced by the passage of multiple interplanetary coronal mass ejections on 22 and 23 May, causing the two spacecraft to magnetically connect to different points back at the Sun. This pair of events illustrates the power of multipoint observations in detailed interpretation of complex events, since only a small shift in observer location results in different magnetic field line connections and different SEP time-intensity profiles.

Parallel multipoint recording of aligned and cultured neurons on corresponding Micro Channel Array toward on-chip cell analysis.

PubMed

Tonomura, W; Moriguchi, H; Jimbo, Y; Konishi, S

2008-01-01

This paper describes an advanced Micro Channel Array (MCA) so as to record neuronal network at multiple points simultaneously. Developed MCA is designed for neuronal network analysis which has been studied by co-authors using MEA (Micro Electrode Arrays) system. The MCA employs the principle of the extracellular recording. Presented MCA has the following advantages. First of all, the electrodes integrated around individual micro channels are electrically isolated for parallel multipoint recording. Sucking and clamping of cells through micro channels is expected to improve the cellular selectivity and S/N ratio. In this study, hippocampal neurons were cultured on the developed MCA. As a result, the spontaneous and evoked spike potential could be recorded by sucking and clamping the cells at multiple points. Herein, we describe the successful experimental results together with the design and fabrication of the advanced MCA toward on-chip analysis of neuronal network.

Polyaniline deposition on tilted fiber Bragg grating for pH sensing

NASA Astrophysics Data System (ADS)

Lopez Aldaba, A.; González-Vila, Á.; Debliquy, M.; Lopez-Amo, M.; Caucheteur, C.; Lahem, D.

2017-04-01

In this paper, we present the results of a new pH sensor based on a polyaniline (PAni) coating on the surface of a tilted fiber Bragg grating. The pH-sensitive PAni was deposited by in situ chemical oxidative polymerization. The performance of the fabricated pH sensor was tested and the obtained pH values were compared with the results obtained using a pH meter device. It was found that the sensor exhibits response to pH changes in the range of 2-12, achieving a sensitivity of 46 pm/pH with a maximum error due to the hysteresis effect of +/-1.14 pH. The main advantages of this PAni-TFBG pH sensor are biochemical compatibility, temperature independence, long-term stability and remote realtime multipoint sensing features. This type of sensor could be used for biochemical applications, pipeline corrosion monitoring or remote-multipoint measurements.

Fabrication of multipoint side-firing optical fiber by laser micro-ablation.

PubMed

Nguyen, Hoang; Parvez Arnob, Md Masud; Becker, Aaron T; Wolfe, John C; Hogan, Matthew K; Horner, Philip J; Shih, Wei-Chuan

2017-05-01

A multipoint, side-firing design enables an optical fiber to output light at multiple desired locations along the fiber body. This provides advantages over traditional end-to-end fibers, especially in applications requiring fiber bundles such as brain stimulation or remote sensing. This Letter demonstrates that continuous wave (CW) laser micro-ablation can controllably create conical-shaped cavities, or side windows, for outputting light. The dimensions of these cavities determine the amount of firing light and their firing angle. Experimental data show that a single side window on a 730 μm fiber can deliver more than 8% of the input light. This can be increased to more than 19% on a 65 μm fiber with side windows created using femtosecond laser ablation and chemical etching. Fine control of light distribution along an optical fiber is critical for various biomedical applications such as light-activated drug-release and optogenetics studies.

Modelisation de l'historique d'operation de groupes turbine-alternateur

NASA Astrophysics Data System (ADS)

Szczota, Mickael

Because of their ageing fleet, the utility managers are increasingly in needs of tools that can help them to plan efficiently maintenance operations. Hydro-Quebec started a project that aim to foresee the degradation of their hydroelectric runner, and use that information to classify the generating unit. That classification will help to know which generating unit is more at risk to undergo a major failure. Cracks linked to the fatigue phenomenon are a predominant degradation mode and the loading sequences applied to the runner is a parameter impacting the crack growth. So, the aim of this memoir is to create a generator able to generate synthetic loading sequences that are statistically equivalent to the observed history. Those simulated sequences will be used as input in a life assessment model. At first, we describe how the generating units are operated by Hydro-Quebec and analyse the available data, the analysis shows that the data are non-stationnary. Then, we review modelisation and validation methods. In the following chapter a particular attention is given to a precise description of the validation and comparison procedure. Then, we present the comparison of three kind of model : Discrete Time Markov Chains, Discrete Time Semi-Markov Chains and the Moving Block Bootstrap. For the first two models, we describe how to take account for the non-stationnarity. Finally, we show that the Markov Chain is not adapted for our case, and that the Semi-Markov chains are better when they include the non-stationnarity. The final choice between Semi-Markov Chains and the Moving Block Bootstrap depends of the user. But, with a long term vision we recommend the use of Semi-Markov chains for their flexibility. Keywords: Stochastic models, Models validation, Reliability, Semi-Markov Chains, Markov Chains, Bootstrap

Modelisation par elements finis du muscle strie

NASA Astrophysics Data System (ADS)

Leonard, Mathieu

Ce present projet de recherche a permis. de creer un modele par elements finis du muscle strie humain dans le but d'etudier les mecanismes engendrant les lesions musculaires traumatiques. Ce modele constitue une plate-forme numerique capable de discerner l'influence des proprietes mecaniques des fascias et de la cellule musculaire sur le comportement dynamique du muscle lors d'une contraction excentrique, notamment le module de Young et le module de cisaillement de la couche de tissu conjonctif, l'orientation des fibres de collagene de cette membrane et le coefficient de poisson du muscle. La caracterisation experimentale in vitro de ces parametres pour des vitesses de deformation elevees a partir de muscles stries humains actifs est essentielle pour l'etude de lesions musculaires traumatiques. Le modele numerique developpe est capable de modeliser la contraction musculaire comme une transition de phase de la cellule musculaire par un changement de raideur et de volume a l'aide des lois de comportement de materiau predefinies dans le logiciel LS-DYNA (v971, Livermore Software Technology Corporation, Livermore, CA, USA). Le present projet de recherche introduit donc un phenomene physiologique qui pourrait expliquer des blessures musculaires courantes (crampes, courbatures, claquages, etc.), mais aussi des maladies ou desordres touchant le tissu conjonctif comme les collagenoses et la dystrophie musculaire. La predominance de blessures musculaires lors de contractions excentriques est egalement exposee. Le modele developpe dans ce projet de recherche met ainsi a l'avant-scene le concept de transition de phase ouvrant la porte au developpement de nouvelles technologies pour l'activation musculaire chez les personnes atteintes de paraplegie ou de muscles artificiels compacts pour l'elaboration de protheses ou d'exosquelettes. Mots-cles Muscle strie, lesion musculaire, fascia, contraction excentrique, modele par elements finis, transition de phase

Effects of Spent Cooling and Swirler Angle on a 9-Point Swirl-Venturi Injector

NASA Technical Reports Server (NTRS)

He, Zhuohui J.; Tacina, Kathleen M.; Lee, Chi-Ming; Tacina, Robert R.; Lee, Phil

2014-01-01

This paper presents multipoint Lean-Direct-Injection (LDI) emissions results for flame tube combustion tests at an inlet pressure of 1034 kPa and inlet temperatures between 835 and 865 K; these are the combustor inlet conditions that the High Speed Research (HSR) program used for supersonic cruise. It focuses on one class of LDI geometry, 9-point swirl-venturi LDI (SV-LDI). Two parameters are compared in this paper: the use of dome cooling air and the swirler blade angle. Dome cooling air is called "spent cooling" and is at combustor inlet conditions. Three cooling variations are studied: cooling at the venturi throat, cooling at the dome face, and no cooling at all. Two swirler blade angles are studied: 45deg and 60deg. The HSR 9-point SV-LDI emissions are also compared to a similar 9-point SV-LDI design which was used in the later ultra-efficient engine technology (UEET) program. The HSR and UEET designs cannot be compared directly due to different UEET combustor conditions. Therefore, this paper uses previously published UEET correlation equations to make comparisons. Results show that using a 45deg swirler produces lower NOx emissions than using a 60deg swirler. This is consistent with the later UEET results. The effects of spent cooling depend on swirler angle, spent cooling location, and the test conditions. For the configuration with 45deg swirlers, spent cooling delivers lower NOx emissions when it is injected at the throat. For the 60deg swirler, spent cooling does not have much effect on NOx emissions. These results might be caused by the location and the intensity of the flame recirculation zone.

Effects of Spent Cooling and Swirler Angle on a 9-point Swirl-Venturi Injector

NASA Technical Reports Server (NTRS)

He, ZH., Joe; Tacina, Kathleen M.; Lee, Chi-Ming; Tacina, Robert R.; Lee, Phil

2013-01-01

This paper presents multipoint lean-direct-injection (LDI) emissions results for flame tube combustion tests at an inlet pressure of 1034 kPa and inlet temperatures between 835 and 865 K; these are the combustor inlet conditions that the High Speed Research (HSR) program used for supersonic cruise. It focuses on one class of LDI geometry, 9-point swirl-venturi LDI (SV-LDI). Two parameters are compared in this paper: the use of dome cooling air and the swirler blade angle. Dome cooling air is called 'spent cooling' and is at combustor inlet conditions. Three cooling variations are studied: cooling at the venturi throat, cooling at the dome face, and no cooling at all. Two swirler blade angles are studied: 45 deg and 60 deg. The HSR 9-point SV-LDI emissions are also compared to a similar 9-point SV-LDI design which was used in the later ultra-efficient engine technology (UEET) program. The HSR and UEET designs cannot be compared directly due to different UEET combustor conditions. Therefore, this paper uses previously published UEET correlation equations to make comparisons. Results show that using a 45 deg swirler produces lower NOx emissions than using a 60 deg swirler. This is consistent with the later UEET results. The effects of spent cooling depend on swirler angle, spent cooling location, and the test conditions. For the configuration with 45 deg swirlers, spent cooling delivers lower NOx emissions when it is injected at the throat. For the 60 deg swirler, spent cooling does not have much effect on NOx emissions. These results might be caused by the location and the intensity of the flame recirculation zone.

Mathematical simulation of thermocouple characteristics

NASA Astrophysics Data System (ADS)

Abouellail, A. A.; Kostina, M. A.; Bortalevich, S. I.; Loginov, E. L.; Shinyakov, Y. A.; Sukhorukov, M. P.

2018-03-01

Within this article, the investigation of the electrical characteristics of two thermocouples in parallel connection was mathematically simulated for further research of the effect of multi-point contact between the sensing thermocouple electrodes and the inspected sample in thermoelectric inspection devices.

Multisites Coordination in Shared Multicast Trees

DTIC Science & Technology

1999-01-01

conferencing, distributed interactive simulations, and collaborative systems. We de- scribe a novel protocol to coordinate multipoint groupwork in the IP...multicast framework. The pro- tocol supports Internet-wide coordination for large and highly-interactive groupwork , relying on trans- mission of

47 CFR 101.1017 - Requesting regulatory status.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Requesting regulatory status. 101.1017 Section 101.1017 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1017 Requesting regulatory...

47 CFR 101.1017 - Requesting regulatory status.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Requesting regulatory status. 101.1017 Section 101.1017 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1017 Requesting regulatory...

47 CFR 101.1013 - Permissible communications services.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Permissible communications services. 101.1013 Section 101.1013 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1013 Permissible...

47 CFR 101.1013 - Permissible communications services.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 5 2014-10-01 2014-10-01 false Permissible communications services. 101.1013 Section 101.1013 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1013 Permissible...

47 CFR 101.1017 - Requesting regulatory status.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 5 2014-10-01 2014-10-01 false Requesting regulatory status. 101.1017 Section 101.1017 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1017 Requesting regulatory...

47 CFR 101.1013 - Permissible communications services.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Permissible communications services. 101.1013 Section 101.1013 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1013 Permissible...

47 CFR 101.1013 - Permissible communications services.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Permissible communications services. 101.1013 Section 101.1013 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1013 Permissible...

47 CFR 101.1017 - Requesting regulatory status.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Requesting regulatory status. 101.1017 Section 101.1017 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1017 Requesting regulatory...

47 CFR 101.1013 - Permissible communications services.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 5 2013-10-01 2013-10-01 false Permissible communications services. 101.1013 Section 101.1013 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1013 Permissible...

47 CFR 101.1017 - Requesting regulatory status.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 5 2013-10-01 2013-10-01 false Requesting regulatory status. 101.1017 Section 101.1017 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1017 Requesting regulatory...

Fabrication and Optimization of Bilayered Nanoporous Anodic Alumina Structures as Multi-Point Interferometric Sensing Platform

PubMed Central

Nemati, Mahdieh; Santos, Abel

2018-01-01

Herein, we present an innovative strategy for optimizing hierarchical structures of nanoporous anodic alumina (NAA) to advance their optical sensing performance toward multi-analyte biosensing. This approach is based on the fabrication of multilayered NAA and the formation of differential effective medium of their structure by controlling three fabrication parameters (i.e., anodization steps, anodization time, and pore widening time). The rationale of the proposed concept is that interferometric bilayered NAA (BL-NAA), which features two layers of different pore diameters, can provide distinct reflectometric interference spectroscopy (RIfS) signatures for each layer within the NAA structure and can therefore potentially be used for multi-point biosensing. This paper presents the structural fabrication of layered NAA structures, and the optimization and evaluation of their RIfS optical sensing performance through changes in the effective optical thickness (EOT) using quercetin as a model molecule. The bilayered or funnel-like NAA structures were designed with the aim of characterizing the sensitivity of both layers of quercetin molecules using RIfS and exploring the potential of these photonic structures, featuring different pore diameters, for simultaneous size-exclusion and multi-analyte optical biosensing. The sensing performance of the prepared NAA platforms was examined by real-time screening of binding reactions between human serum albumin (HSA)-modified NAA (i.e., sensing element) and quercetin (i.e., analyte). BL-NAAs display a complex optical interference spectrum, which can be resolved by fast Fourier transform (FFT) to monitor the EOT changes, where three distinctive peaks were revealed corresponding to the top, bottom, and total layer within the BL-NAA structures. The spectral shifts of these three characteristic peaks were used as sensing signals to monitor the binding events in each NAA pore in real-time upon exposure to different concentrations of quercetin. The multi-point sensing performance of BL-NAAs was determined for each pore layer, with an average sensitivity and low limit of detection of 600 nm (mg mL−1)−1 and 0.14 mg mL−1, respectively. BL-NAAs photonic structures have the capability to be used as platforms for multi-point RIfS sensing of biomolecules that can be further extended for simultaneous size-exclusion separation and multi-analyte sensing using these bilayered nanostructures. PMID:29415436

Unsteady Aerodynamics - Fundamentals and Applications of Aircraft Dynamics. Conference Proceedings of the Joint Symposium of the Fluid Dynamics and Flight Mechanics Panels Held in Goettingen, Federal Republic of Germany on 6-9 May 1985.

DTIC Science & Technology

1985-11-01

tourbillons daxe perpendicu-V laire A l’fcoulement principal) issu d’un profil occillant en Tamis dan;, do,, condition,, dn dorochagp dynamique. 5_10...a~rodyna- - mique sur R. A partir de cette analyse experimentale, une tentative de modelisation th~sorique des effets non *lin~ laires observes aux...cisaillement A la paroi d’un profil d’aile anim6 d’un mouvament harmonique parall~le ou parpandicu- laire A 1𔄀coulement non perturb~s", EUROMECH

Modelisation of an unspecialized quadruped walking mammal.

PubMed

Neveu, P; Villanova, J; Gasc, J P

2001-12-01

Kinematics and structural analyses were used as basic data to elaborate a dynamic quadruped model that may represent an unspecialized mammal. Hedgehogs were filmed on a treadmill with a cinefluorographic system providing trajectories of skeletal elements during locomotion. Body parameters such as limb segments mass and length, and segments centre of mass were checked from cadavers. These biological parameters were compiled in order to build a virtual quadruped robot. The robot locomotor behaviour was compared with the actual hedgehog to improve the model and to disclose the necessary changes. Apart from use in robotics, the resulting model may be useful to simulate the locomotion of extinct mammals.

Efficient Group Coordination in Multicast Trees

DTIC Science & Technology

2001-01-01

describe a novel protocol to coordinate multipoint groupwork within the IP-multicast framework. The protocol supports Internet-wide coordination for large...and highly-interactive groupwork , relying on the dissemination of coordination directives among group members across a shared end-to-end multicast

47 CFR 101.1001 - Eligibility.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Eligibility. 101.1001 Section 101.1001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1001 Eligibility. Any entity, other than one precluded...

47 CFR 101.1001 - Eligibility.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Eligibility. 101.1001 Section 101.1001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1001 Eligibility. Any entity, other than one precluded...

47 CFR 101.1001 - Eligibility.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Eligibility. 101.1001 Section 101.1001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1001 Eligibility. Any entity, other than one precluded...

47 CFR 101.1001 - Eligibility.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 5 2013-10-01 2013-10-01 false Eligibility. 101.1001 Section 101.1001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1001 Eligibility. Any entity, other than one precluded...

47 CFR 101.1001 - Eligibility.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 5 2014-10-01 2014-10-01 false Eligibility. 101.1001 Section 101.1001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1001 Eligibility. Any entity, other than one precluded...

47 CFR 27.1200 - Change to BRS and EBS.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1200 Change to BRS and EBS... Multichannel Multipoint Distribution Service (MMDS) shall be reassigned to the Broadband Radio Service (BRS...

47 CFR 27.1200 - Change to BRS and EBS.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1200 Change to BRS and EBS... Multichannel Multipoint Distribution Service (MMDS) shall be reassigned to the Broadband Radio Service (BRS...

47 CFR 27.1200 - Change to BRS and EBS.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1200 Change to BRS and EBS... Multichannel Multipoint Distribution Service (MMDS) shall be reassigned to the Broadband Radio Service (BRS...

47 CFR 27.1200 - Change to BRS and EBS.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1200 Change to BRS and EBS... Multichannel Multipoint Distribution Service (MMDS) shall be reassigned to the Broadband Radio Service (BRS...

47 CFR 27.1200 - Change to BRS and EBS.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and Educational Broadband Service § 27.1200 Change to BRS and EBS... Multichannel Multipoint Distribution Service (MMDS) shall be reassigned to the Broadband Radio Service (BRS...

Local Network Wideband Interconnection Alternatives.

DTIC Science & Technology

1984-01-01

signal. 3.2.2 Limitations Although satellites offer the advantages of insensitivity to distance, point-to-multipoint communication capability and...Russell, the CATV franchisee for the town of Bedford, has not yit set rates for leasing channels on their network. If this network were interconnected

Simple-to-prepare multipoint field emitter

NASA Astrophysics Data System (ADS)

Sominskii, G. G.; Taradaev, E. P.; Tumareva, T. A.; Mishin, M. V.; Kornishin, S. Yu.

2015-07-01

We investigate multitip field emitters prepared by electroerosion treatment of the surface of molybdenum samples. Their characteristics are determined for operation with a protecting activated fullerene coating. Our experiments indicate that such cathodes are promising for high-voltage electron devices operating in technical vacuum.

47 CFR 22.625 - Transmitter locations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Transmitter locations. 22.625 Section 22.625... Paging and Radiotelephone Service Point-To-Multipoint Operation § 22.625 Transmitter locations. This... channels will occur. (1) Control transmitter locations. Control transmitter locations must be within 80...

47 CFR 101.1009 - System operations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false System operations. 101.1009 Section 101.1009 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1009 System operations. (a) The licensee may construct...

47 CFR 101.1009 - System operations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false System operations. 101.1009 Section 101.1009 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1009 System operations. (a) The licensee may construct...

47 CFR 101.1009 - System operations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 5 2013-10-01 2013-10-01 false System operations. 101.1009 Section 101.1009 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1009 System operations. (a) The licensee may construct...

47 CFR 101.1009 - System operations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 5 2014-10-01 2014-10-01 false System operations. 101.1009 Section 101.1009 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1009 System operations. (a) The licensee may construct...

47 CFR 101.1009 - System operations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false System operations. 101.1009 Section 101.1009 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1009 System operations. (a) The licensee may construct...

Modelisation de photodetecteurs a base de matrices de diodes avalanche monophotoniques pour tomographie d'emission par positrons

NASA Astrophysics Data System (ADS)

Corbeil Therrien, Audrey

La tomographie d'emission par positrons (TEP) est un outil precieux en recherche preclinique et pour le diagnostic medical. Cette technique permet d'obtenir une image quantitative de fonctions metaboliques specifiques par la detection de photons d'annihilation. La detection des ces photons se fait a l'aide de deux composantes. D'abord, un scintillateur convertit l'energie du photon 511 keV en photons du spectre visible. Ensuite, un photodetecteur convertit l'energie lumineuse en signal electrique. Recemment, les photodiodes avalanche monophotoniques (PAMP) disposees en matrice suscitent beaucoup d'interet pour la TEP. Ces matrices forment des detecteurs sensibles, robustes, compacts et avec une resolution en temps hors pair. Ces qualites en font un photodetecteur prometteur pour la TEP, mais il faut optimiser les parametres de la matrice et de l'electronique de lecture afin d'atteindre les performances optimales pour la TEP. L'optimisation de la matrice devient rapidement une operation difficile, car les differents parametres interagissent de maniere complexe avec les processus d'avalanche et de generation de bruit. Enfin, l'electronique de lecture pour les matrices de PAMP demeure encore rudimentaire et il serait profitable d'analyser differentes strategies de lecture. Pour repondre a cette question, la solution la plus economique est d'utiliser un simulateur pour converger vers la configuration donnant les meilleures performances. Les travaux de ce memoire presentent le developpement d'un tel simulateur. Celui-ci modelise le comportement d'une matrice de PAMP en se basant sur les equations de physique des semiconducteurs et des modeles probabilistes. Il inclut les trois principales sources de bruit, soit le bruit thermique, les declenchements intempestifs correles et la diaphonie optique. Le simulateur permet aussi de tester et de comparer de nouvelles approches pour l'electronique de lecture plus adaptees a ce type de detecteur. Au final, le simulateur vise a quantifier l'impact des parametres du photodetecteur sur la resolution en energie et la resolution en temps et ainsi optimiser les performances de la matrice de PAMP. Par exemple, l'augmentation du ratio de surface active ameliore les performances, mais seulement jusqu'a un certain point. D'autres phenomenes lies a la surface active, comme le bruit thermique, provoquent une degradation du resultat. Le simulateur nous permet de trouver un compromis entre ces deux extremes. Les simulations avec les parametres initiaux demontrent une efficacite de detection de 16,7 %, une resolution en energie de 14,2 % LMH et une resolution en temps de 0.478 ns LMH. Enfin, le simulateur propose, bien qu'il vise une application en TEP, peut etre adapte pour d'autres applications en modifiant la source de photons et en adaptant les objectifs de performances. Mots-cles : Photodetecteurs, photodiodes avalanche monophotoniques, semiconducteurs, tomographie d'emission par positrons, simulations, modelisation, detection monophotonique, scintillateurs, circuit d'etouffement, SPAD, SiPM, Photodiodes avalanche operees en mode Geiger

Etude de la dynamique des porteurs dans des nanofils de silicium par spectroscopie terahertz

NASA Astrophysics Data System (ADS)

Beaudoin, Alexandre

Ce memoire presente une etude des proprietes de conduction electrique et de la dynamique temporelle des porteurs de charges dans des nanofils de silicium sondes par rayonnement terahertz. Les cas de nanofils de silicium non intentionnellement dopes et dopes type n sont compares pour differentes configurations du montage experimental. Les mesures de spectroscopie terahertz en transmission montre qu'il est possible de detecter la presence de dopants dans les nanofils via leur absorption du rayonnement terahertz (˜ 1--12 meV). Les difficultes de modelisation de la transmission d'une impulsion electromagnetique dans un systeme de nanofils sont egalement discutees. La detection differentielle, une modification au systeme de spectroscopie terahertz, est testee et ses performances sont comparees au montage de caracterisation standard. Les instructions et des recommendations pour la mise en place de ce type de mesure sont incluses. Les resultats d'une experience de pompe optique-sonde terahertz sont egalement presentes. Dans cette experience, les porteurs de charge temporairement crees suite a l'absorption de la pompe optique (lambda ˜ 800 nm) dans les nanofils (les photoporteurs) s'ajoutent aux porteurs initialement presents et augmentent done l'absorption du rayonnement terahertz. Premierement, l'anisotropie de l'absorption terahertz et de la pompe optique par les nanofils est demontree. Deuxiemement, le temps de recombinaison des photoporteurs est etudie en fonction du nombre de photoporteurs injectes. Une hypothese expliquant les comportements observes pour les nanofils non-dopes et dopes-n est presentee. Troisiemement, la photoconductivite est extraite pour les nanofils non-dopes et dopes-n sur une plage de 0.5 a 2 THz. Un lissage sur la photoconductivite permet d'estimer le nombre de dopants dans les nanofils dopes-n. Mots-cles: nanofil, silicium, terahertz, conductivite, spectroscopie, photoconductivite.

Multipoint Binding of the SLP-76 SH2 Domain to ADAP Is Critical for Oligomerization of SLP-76 Signaling Complexes in Stimulated T Cells

PubMed Central

Coussens, Nathan P.; Hayashi, Ryo; Brown, Patrick H.; Balagopalan, Lakshmi; Balbo, Andrea; Akpan, Itoro; Houtman, Jon C. D.; Barr, Valarie A.; Schuck, Peter; Appella, Ettore

2013-01-01

The adapter molecules SLP-76 and LAT play central roles in T cell activation by recruiting enzymes and other adapters into multiprotein complexes that coordinate highly regulated signal transduction pathways. While many of the associated proteins have been characterized, less is known concerning the mechanisms of assembly for these dynamic and potentially heterogeneous signaling complexes. Following T cell receptor (TCR) stimulation, SLP-76 is found in structures called microclusters, which contain many signaling complexes. Previous studies showed that a mutation to the SLP-76 C-terminal SH2 domain nearly abolished SLP-76 microclusters, suggesting that the SH2 domain facilitates incorporation of signaling complexes into microclusters. S. C. Bunnell, A. L. Singer, D. I. Hong, B. H. Jacque, M. S. Jordan, M. C. Seminario, V. A. Barr, G. A. Koretzky, and L. E. Samelson, Mol. Cell. Biol., 26:7155–7166, 2006). Using biophysical methods, we demonstrate that the adapter, ADAP, contains three binding sites for SLP-76, and that multipoint binding to ADAP fragments oligomerizes the SLP-76 SH2 domain in vitro. These results were complemented with confocal imaging and functional studies of cells expressing ADAP with various mutations. Our results demonstrate that all three binding sites are critical for SLP-76 microcluster assembly, but any combination of two sites will partially induce microclusters. These data support a model whereby multipoint binding of SLP-76 to ADAP facilitates the assembly of SLP-76 microclusters. This model has implications for the regulation of SLP-76 and LAT microclusters and, as a result, T cell signaling. PMID:23979596

Multipoint binding of the SLP-76 SH2 domain to ADAP is critical for oligomerization of SLP-76 signaling complexes in stimulated T cells.

PubMed

Coussens, Nathan P; Hayashi, Ryo; Brown, Patrick H; Balagopalan, Lakshmi; Balbo, Andrea; Akpan, Itoro; Houtman, Jon C D; Barr, Valarie A; Schuck, Peter; Appella, Ettore; Samelson, Lawrence E

2013-11-01

The adapter molecules SLP-76 and LAT play central roles in T cell activation by recruiting enzymes and other adapters into multiprotein complexes that coordinate highly regulated signal transduction pathways. While many of the associated proteins have been characterized, less is known concerning the mechanisms of assembly for these dynamic and potentially heterogeneous signaling complexes. Following T cell receptor (TCR) stimulation, SLP-76 is found in structures called microclusters, which contain many signaling complexes. Previous studies showed that a mutation to the SLP-76 C-terminal SH2 domain nearly abolished SLP-76 microclusters, suggesting that the SH2 domain facilitates incorporation of signaling complexes into microclusters. S. C. Bunnell, A. L. Singer, D. I. Hong, B. H. Jacque, M. S. Jordan, M. C. Seminario, V. A. Barr, G. A. Koretzky, and L. E. Samelson, Mol. Cell. Biol., 26:7155-7166, 2006). Using biophysical methods, we demonstrate that the adapter, ADAP, contains three binding sites for SLP-76, and that multipoint binding to ADAP fragments oligomerizes the SLP-76 SH2 domain in vitro. These results were complemented with confocal imaging and functional studies of cells expressing ADAP with various mutations. Our results demonstrate that all three binding sites are critical for SLP-76 microcluster assembly, but any combination of two sites will partially induce microclusters. These data support a model whereby multipoint binding of SLP-76 to ADAP facilitates the assembly of SLP-76 microclusters. This model has implications for the regulation of SLP-76 and LAT microclusters and, as a result, T cell signaling.

Evidence for bivariate linkage of obesity and HDL-C levels in the Framingham Heart Study.

PubMed

Arya, Rector; Lehman, Donna; Hunt, Kelly J; Schneider, Jennifer; Almasy, Laura; Blangero, John; Stern, Michael P; Duggirala, Ravindranath

2003-12-31

Epidemiological studies have indicated that obesity and low high-density lipoprotein (HDL) levels are strong cardiovascular risk factors, and that these traits are inversely correlated. Despite the belief that these traits are correlated in part due to pleiotropy, knowledge on specific genes commonly affecting obesity and dyslipidemia is very limited. To address this issue, we first conducted univariate multipoint linkage analysis for body mass index (BMI) and HDL-C to identify loci influencing variation in these phenotypes using Framingham Heart Study data relating to 1702 subjects distributed across 330 pedigrees. Subsequently, we performed bivariate multipoint linkage analysis to detect common loci influencing covariation between these two traits. We scanned the genome and identified a major locus near marker D6S1009 influencing variation in BMI (LOD = 3.9) using the program SOLAR. We also identified a major locus for HDL-C near marker D2S1334 on chromosome 2 (LOD = 3.5) and another region near marker D6S1009 on chromosome 6 with suggestive evidence for linkage (LOD = 2.7). Since these two phenotypes have been independently mapped to the same region on chromosome 6q, we used the bivariate multipoint linkage approach using SOLAR. The bivariate linkage analysis of BMI and HDL-C implicated the genetic region near marker D6S1009 as harboring a major gene commonly influencing these phenotypes (bivariate LOD = 6.2; LODeq = 5.5) and appears to improve power to map the correlated traits to a region, precisely. We found substantial evidence for a quantitative trait locus with pleiotropic effects, which appears to influence both BMI and HDL-C phenotypes in the Framingham data.

Development of an FPGA-based multipoint laser pyroshock measurement system for explosive bolts

NASA Astrophysics Data System (ADS)

Abbas, Syed Haider; Jang, Jae-Kyeong; Lee, Jung-Ryul; Kim, Zaeill

2016-07-01

Pyroshock can cause failure to the objective of an aerospace structure by damaging its sensitive electronic equipment, which is responsible for performing decisive operations. A pyroshock is the high intensity shock wave that is generated when a pyrotechnic device is explosively triggered to separate, release, or activate structural subsystems of an aerospace architecture. Pyroshock measurement plays an important role in experimental simulations to understand the characteristics of pyroshock on the host structure. This paper presents a technology to measure a pyroshock wave at multiple points using laser Doppler vibrometers (LDVs). These LDVs detect the pyroshock wave generated due to an explosive-based pyrotechnical event. Field programmable gate array (FPGA) based data acquisition is used in the study to acquire pyroshock signals simultaneously from multiple channels. This paper describes the complete system design for multipoint pyroshock measurement. The firmware architecture for the implementation of multichannel data acquisition on an FPGA-based development board is also discussed. An experiment using explosive bolts was configured to test the reliability of the system. Pyroshock was generated using explosive excitation on a 22-mm-thick steel plate. Three LDVs were deployed to capture the pyroshock wave at different points. The pyroshocks captured were displayed as acceleration plots. The results showed that our system effectively captured the pyroshock wave with a peak-to-peak magnitude of 303 741 g. The contribution of this paper is a specialized architecture of firmware design programmed in FPGA for data acquisition of large amount of multichannel pyroshock data. The advantages of the developed system are the near-field, multipoint, non-contact, and remote measurement of a pyroshock wave, which is dangerous and expensive to produce in aerospace pyrotechnic tests.

Characteristics of Ion Distribution Functions in Dipolarizing FluxBundles: THEMIS Event Studies

NASA Astrophysics Data System (ADS)

Runov, A.; Artemyev, A.; Birn, J.; Pritchett, P. L.; Zhou, X.

2016-12-01

Taking advantage of multi-point observations from repeating configuration of the Time History of Events and Macroscale Interactions during Substorms (THEMIS) fleet with probe separation of 1 to 2 Earth radii (RE) along X, Y, and Z in the geocentric solar magnetospheric system (GSM), we study ion distribution functions observed by the probes during three transient dipolarization events. Comparing observations by the multiple probes, we characterize changes in the ion distribution functions with respect to geocentric distance (X), cross-tail probe separation (Y), and levels of |Bx|, which characterize the distance from the neutral sheet. We examined 2-D and 1-D cuts of the 3-D velocity distribution functions by the {Vb,Vbxv} plane. The results indicate that the velocity distribution functions observed inside the dipolarizing flux bundles (DFB) close to the magnetic equator are often perpendicularly anisotropic for velocities Vth≤v≤2Vth, where Vth is the ion thermal velocity. Ions of higher energies (v>2Vth) are isotropic. Hence, interaction of DFBs and ambient ions may result in the perpendicular anisotropy of the injecting energetic ions, which is an important factor for plasma waves and instabilities excitation and further particle acceleration in the inner magnetosphere. We also compare the observations with the results of test-particles and PIC simulations.

Characteristics of ion distribution functions in dipolarizing flux bundles: Event studies

NASA Astrophysics Data System (ADS)

Runov, A.; Angelopoulos, V.; Artemyev, A.; Birn, J.; Pritchett, P. L.; Zhou, X.-Z.

2017-06-01

Taking advantage of multipoint observations from a repeating configuration of the five Time History of Events and Macroscale Interactions during Substorms (THEMIS) probes separated by 1 to 2 Earth radii (RE) along X, Y, and Z in the geocentric solar magnetospheric system (GSM), we study ion distribution functions collected by the probes during three dipolarizing flux bundle (DFB) events observed at geocentric distances 9 < R < 14 RE. By comparing these probes' observations, we characterize changes in the ion distribution functions with respect to probe separation along the X and Y GSM directions and |Bx| levels, which characterize the distance from the neutral sheet. We found that the characteristics of the ion distribution functions strongly depended on the |Bx| level, whereas changes with respect to X and Y were minor. In all three events, ion distribution functions f(v) observed inside DFBs were organized by magnetic and electric fields. The probes near the magnetic equator observed perpendicular anisotropy of the phase space density in the range between thermal energy and twice the thermal energy, although the distribution in the ambient plasma sheet was isotropic. The anisotropic ion distribution in DFBs injected toward the inner magnetosphere may provide the free energy for waves and instabilities, which are important elements of particle energization.

Acquisition and processing of advanced sensor data for ERW and UXO detection and classification

NASA Astrophysics Data System (ADS)

Schultz, Gregory M.; Keranen, Joe; Miller, Jonathan S.; Shubitidze, Fridon

2014-06-01

The remediation of explosive remnants of war (ERW) and associated unexploded ordnance (UXO) has seen improvements through the injection of modern technological advances and streamlined standard operating procedures. However, reliable and cost-effective detection and geophysical mapping of sites contaminated with UXO such as cluster munitions, abandoned ordnance, and improvised explosive devices rely on the ability to discriminate hazardous items from metallic clutter. In addition to anthropogenic clutter, handheld and vehicle-based metal detector systems are plagued by natural geologic and environmental noise in many post conflict areas. We present new and advanced electromagnetic induction (EMI) technologies including man-portable and towed EMI arrays and associated data processing software. While these systems feature vastly different form factors and transmit-receive configurations, they all exhibit several fundamental traits that enable successful classification of EMI anomalies. Specifically, multidirectional sampling of scattered magnetic fields from targets and corresponding high volume of unique data provide rich information for extracting useful classification features for clutter rejection analysis. The quality of classification features depends largely on the extent to which the data resolve unique physics-based parameters. To date, most of the advanced sensors enable high quality inversion by producing data that are extremely rich in spatial content through multi-angle illumination and multi-point reception.

47 CFR 101.1007 - Geographic service areas and number of licenses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Geographic service areas and number of licenses. 101.1007 Section 101.1007 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1007...

Optimal Ventilation Control in Complex Urban Tunnels with Multi-Point Pollutant Discharge

DOT National Transportation Integrated Search

2017-10-01

Zhen Tan (ORCID ID 0000-0003-1711-3557) H. Oliver Gao (ORCID ID 0000-0002-7861-9634) We propose an optimal ventilation control model for complex urban vehicular tunnels with distributed pollutant discharge points. The control problem is formulated as...

47 CFR 101.5 - Station authorization required.

Code of Federal Regulations, 2014 CFR

2014-10-01

... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses General Filing Requirements § 101.5 Station... stations authorized under subpart H (Private Operational Fixed Point-to-Point Microwave Service), subpart I (Common Carrier Fixed Point-to-Point Microwave Service), and subpart L of this part (Local Multipoint...

47 CFR 101.5 - Station authorization required.

Code of Federal Regulations, 2010 CFR

2010-10-01

... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses General Filing Requirements § 101.5 Station... stations authorized under subpart H (Private Operational Fixed Point-to-Point Microwave Service), subpart I (Common Carrier Fixed Point-to-Point Microwave Service), and subpart L of this part (Local Multipoint...

47 CFR 101.1007 - Geographic service areas and number of licenses.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 5 2014-10-01 2014-10-01 false Geographic service areas and number of licenses. 101.1007 Section 101.1007 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1007...

47 CFR 101.1007 - Geographic service areas and number of licenses.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 5 2013-10-01 2013-10-01 false Geographic service areas and number of licenses. 101.1007 Section 101.1007 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1007...

47 CFR 101.5 - Station authorization required.

Code of Federal Regulations, 2013 CFR

2013-10-01

... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses General Filing Requirements § 101.5 Station... stations authorized under subpart H (Private Operational Fixed Point-to-Point Microwave Service), subpart I (Common Carrier Fixed Point-to-Point Microwave Service), and subpart L of this part (Local Multipoint...

47 CFR 101.1007 - Geographic service areas and number of licenses.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Geographic service areas and number of licenses. 101.1007 Section 101.1007 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Local Multipoint Distribution Service § 101.1007...

47 CFR 101.5 - Station authorization required.

Code of Federal Regulations, 2012 CFR

2012-10-01

... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses General Filing Requirements § 101.5 Station... stations authorized under subpart H (Private Operational Fixed Point-to-Point Microwave Service), subpart I (Common Carrier Fixed Point-to-Point Microwave Service), and subpart L of this part (Local Multipoint...

47 CFR 101.5 - Station authorization required.

Code of Federal Regulations, 2011 CFR

2011-10-01

... SERVICES FIXED MICROWAVE SERVICES Applications and Licenses General Filing Requirements § 101.5 Station... stations authorized under subpart H (Private Operational Fixed Point-to-Point Microwave Service), subpart I (Common Carrier Fixed Point-to-Point Microwave Service), and subpart L of this part (Local Multipoint...

A novel, cost-effective, multi-point Thomson scattering system on the Pegasus Toroidal Experiment (invited)

DOE PAGES

Schlossberg, David J.; Bodner, Grant M.; Bongard, Michael W.; ...

2016-09-16

Here, a novel, cost-effective, multi-point Thomson scattering system has been designed, implemented, and operated on the Pegasus Toroidal Experiment. Leveraging advances in Nd:YAG lasers, high-efficiency volume phase holographic transmission gratings, and increased quantum-efficiency Generation 3 image-intensified charge coupled device (ICCD) cameras, the system provides Thomson spectra at eight spatial locations for a single grating/camera pair. The on-board digitization of the ICCD camera enables easy modular expansion, evidenced by recent extension from 4 to 12 plasma/background spatial location pairs. Stray light is rejected using time-of-flight methods suited to gated ICCDs, and background light is blocked during detector readout by a fastmore » shutter. This –10 3 reduction in background light enables further expansion to up to 24 spatial locations. The implementation now provides single-shot T e(R) for n e > 5 × 10 18 m –3.« less

Linkage analysis in a Dutch family with X-linked recessive congenital stationary night blindness (XL-CSNB).

PubMed

Berger, W; van Duijnhoven, G; Pinckers, A; Smits, A; Ropers, H H; Cremers, F

1995-01-01

Linkage analysis has been performed in a large Dutch pedigree with X-linked recessive congenital stationary night blindness (CSNB) by utilizing 16 DNA markers from the proximal short arm of the human X chromosome (Xp21.1-11.2). Thirteen polymorphic markers are at least partially informative and have enabled pairwise and multipoint linkage analysis. For three loci, i.e. DXS228, the monoamine oxidase B gene and the Norrie disease gene (NDG), multipoint linkage studies have yielded maximum lod scores of > 3.0 at a recombination fraction of zero. Analysis of recombination events has enabled us to rule out the possibility that the underlying defect in this family is allelic to RP3; the gene defect could also be excluded from the proximal part of the region known to carry RP2. Linkage data are consistent with a possible involvement of the NDG but mutations in the open reading frame of this gene have not been found.

Morphing Wings: A Study Using High-Fidelity Aerodynamic Shape Optimization

NASA Astrophysics Data System (ADS)

Curiale, Nathanael J.

With the aviation industry under pressure to reduce fuel consumption, morphing wings have the capacity to improve aircraft performance, thereby making a significant contribution to reversing climate change. Through high-fidelity aerodynamic shape optimization, various forms of morphing wings are assessed for a hypothetical regional-class aircraft. The framework used solves the Reynolds-averaged Navier-Stokes equations and utilizes a gradient-based optimization algorithm. Baseline geometries are developed through multipoint optimization, where the average drag coefficient is minimized over a range of flight conditions with additional dive constraints. Morphing optimizations are then performed, beginning with these baseline shapes. Five distinct types of morphing are investigated and compared. Overall, a theoretical fully adaptable wing produces roughly a 2% improvement in average performance, whereas trailing-edge morphing with a 27-point multipoint baseline results in just over a 1% improvement in average performance. Trailing-edge morphing proves to be more beneficial than leading-edge morphing, upper-surface morphing, and a conventional flap.

A Bionic Camera-Based Polarization Navigation Sensor

PubMed Central

Wang, Daobin; Liang, Huawei; Zhu, Hui; Zhang, Shuai

2014-01-01

Navigation and positioning technology is closely related to our routine life activities, from travel to aerospace. Recently it has been found that Cataglyphis (a kind of desert ant) is able to detect the polarization direction of skylight and navigate according to this information. This paper presents a real-time bionic camera-based polarization navigation sensor. This sensor has two work modes: one is a single-point measurement mode and the other is a multi-point measurement mode. An indoor calibration experiment of the sensor has been done under a beam of standard polarized light. The experiment results show that after noise reduction the accuracy of the sensor can reach up to 0.3256°. It is also compared with GPS and INS (Inertial Navigation System) in the single-point measurement mode through an outdoor experiment. Through time compensation and location compensation, the sensor can be a useful alternative to GPS and INS. In addition, the sensor also can measure the polarization distribution pattern when it works in multi-point measurement mode. PMID:25051029

Composite, all-ceramics, high-peak power Nd:YAG/Cr(4+):YAG monolithic micro-laser with multiple-beam output for engine ignition.

PubMed

Pavel, Nicolaie; Tsunekane, Masaki; Taira, Takunori

2011-05-09

A passively Q-switched Nd:YAG/Cr(4+):YAG micro-laser with three-beam output was realized. A single active laser source made of a composite, all-ceramics Nd:YAG/Cr(4+):YAG monolithic cavity was pumped by three independent lines. At 5 Hz repetition rate, each line delivered laser pulses with ~2.4 mJ energy and 2.8-MW peak power. The M(2) factor of a laser beam was 3.7, and stable air breakdowns were realized. The increase of pump repetition rate up to 100 Hz improved the laser pulse energy by 6% and required ~6% increase of the pump pulse energy. Pulse timing of the laser-array beams can by adjusted by less than 5% tuning of an individual line pump energy, and therefore simultaneous multi-point ignition is possible. This kind of laser can be used for multi-point ignition of an automobile engine. © 2011 Optical Society of America

Multi-point optimization of recirculation flow type casing treatment in centrifugal compressors

NASA Astrophysics Data System (ADS)

Tun, Min Thaw; Sakaguchi, Daisaku

2016-06-01

High-pressure ratio and wide operating range are highly required for a turbocharger in diesel engines. A recirculation flow type casing treatment is effective for flow range enhancement of centrifugal compressors. Two ring grooves on a suction pipe and a shroud casing wall are connected by means of an annular passage and stable recirculation flow is formed at small flow rates from the downstream groove toward the upstream groove through the annular bypass. The shape of baseline recirculation flow type casing is modified and optimized by using a multi-point optimization code with a metamodel assisted evolutionary algorithm embedding a commercial CFD code CFX from ANSYS. The numerical optimization results give the optimized design of casing with improving adiabatic efficiency in wide operating flow rate range. Sensitivity analysis of design parameters as a function of efficiency has been performed. It is found that the optimized casing design provides optimized recirculation flow rate, in which an increment of entropy rise is minimized at grooves and passages of the rotating impeller.

A coal mine multi-point fiber ethylene gas concentration sensor

NASA Astrophysics Data System (ADS)

Wei, Yubin; Chang, Jun; Lian, Jie; Liu, Tongyu

2015-03-01

Spontaneous combustion of the coal mine goaf is one of the main disasters in the coal mine. The detection technology based on symbolic gas is the main means to realize the spontaneous combustion prediction of the coal mine goaf, and ethylene gas is an important symbol gas of spontaneous combustion in the coal accelerated oxidation stage. In order to overcome the problem of current coal ethylene detection, the paper presents a mine optical fiber multi-point ethylene concentration sensor based on the tunable diode laser absorption spectroscopy. Based on the experiments and analysis of the near-infrared spectrum of ethylene, the system employed the 1.62 μm (DFB) wavelength fiber coupled distributed feedback laser as the light source. By using the wavelength scanning technique and developing a stable fiber coupled Herriot type long path gas absorption cell, a ppm-level high sensitivity detecting system for the concentration of ethylene gas was realized, which could meet the needs of coal mine fire prevention goaf prediction.

The Electrophysiological MEMS Device with Micro Channel Array for Cellular Network Analysis

NASA Astrophysics Data System (ADS)

Tonomura, Wataru; Kurashima, Toshiaki; Takayama, Yuzo; Moriguchi, Hiroyuki; Jimbo, Yasuhiko; Konishi, Satoshi

This paper describes a new type of MCA (Micro Channel Array) for simultaneous multipoint measurement of cellular network. Presented MCA employing the measurement principles of the patch-clamp technique is designed for advanced neural network analysis which has been studied by co-authors using 64ch MEA (Micro Electrode Arrays) system. First of all, sucking and clamping of cells through channels of developed MCA is expected to improve electrophysiological signal detections. Electrophysiological sensing electrodes integrated around individual channels of MCA by using MEMS (Micro Electro Mechanical System) technologies are electrically isolated for simultaneous multipoint measurement. In this study, we tested the developed MCA using the non-cultured rat's cerebral cortical slice and the hippocampal neurons. We could measure the spontaneous action potential of the slice simultaneously at multiple points and culture the neurons on developed MCA. Herein, we describe the experimental results together with the design and fabrication of the electrophysiological MEMS device with MCA for cellular network analysis.

A synchronized multipoint vision-based system for displacement measurement of civil infrastructures.

PubMed

Ho, Hoai-Nam; Lee, Jong-Han; Park, Young-Soo; Lee, Jong-Jae

2012-01-01

This study presents an advanced multipoint vision-based system for dynamic displacement measurement of civil infrastructures. The proposed system consists of commercial camcorders, frame grabbers, low-cost PCs, and a wireless LAN access point. The images of target panels attached to a structure are captured by camcorders and streamed into the PC via frame grabbers. Then the displacements of targets are calculated using image processing techniques with premeasured calibration parameters. This system can simultaneously support two camcorders at the subsystem level for dynamic real-time displacement measurement. The data of each subsystem including system time are wirelessly transferred from the subsystem PCs to master PC and vice versa. Furthermore, synchronization process is implemented to ensure the time synchronization between the master PC and subsystem PCs. Several shaking table tests were conducted to verify the effectiveness of the proposed system, and the results showed very good agreement with those from a conventional sensor with an error of less than 2%.

A Synchronized Multipoint Vision-Based System for Displacement Measurement of Civil Infrastructures

PubMed Central

Ho, Hoai-Nam; Lee, Jong-Han; Park, Young-Soo; Lee, Jong-Jae

2012-01-01

This study presents an advanced multipoint vision-based system for dynamic displacement measurement of civil infrastructures. The proposed system consists of commercial camcorders, frame grabbers, low-cost PCs, and a wireless LAN access point. The images of target panels attached to a structure are captured by camcorders and streamed into the PC via frame grabbers. Then the displacements of targets are calculated using image processing techniques with premeasured calibration parameters. This system can simultaneously support two camcorders at the subsystem level for dynamic real-time displacement measurement. The data of each subsystem including system time are wirelessly transferred from the subsystem PCs to master PC and vice versa. Furthermore, synchronization process is implemented to ensure the time synchronization between the master PC and subsystem PCs. Several shaking table tests were conducted to verify the effectiveness of the proposed system, and the results showed very good agreement with those from a conventional sensor with an error of less than 2%. PMID:23028250

Three-dimensional imaging of absolute blood flow velocity and blood vessel position under low blood flow velocity based on Doppler signal information included in scattered light from red blood cells

NASA Astrophysics Data System (ADS)

Kyoden, Tomoaki; Akiguchi, Shunsuke; Tajiri, Tomoki; Andoh, Tsugunobu; Hachiga, Tadashi

2017-11-01

The development of a system for in vivo visualization of occluded distal blood vessels for diabetic patients is the main target of our research. We herein describe two-beam multipoint laser Doppler velocimetry (MLDV), which measures the instantaneous multipoint flow velocity and can be used to observe the blood flow velocity in peripheral blood vessels. By including a motorized stage to shift the measurement points horizontally and in the depth direction while measuring the velocity, the path of the blood vessel in the skin could be observed using blood flow velocity in three-dimensional space. The relationship of the signal power density between the blood vessel and the surrounding tissues was shown and helped us identify the position of the blood vessel. Two-beam MLDV can be used to simultaneously determine the absolute blood flow velocity distribution and identify the blood vessel position in skin.

Full Mesh Audio Conferencing Using the Point-to-Multipoint On-Board Switching Capability of ACTS

NASA Technical Reports Server (NTRS)

Rivett, Mary L.; Sethna, Zubin H.

1996-01-01

The purpose of this paper is to describe an implementation of audio conferencing using the ACTS T1-VSAT network. In particular, this implementation evaluates the use of the on-board switching capability of the satellite as a viable alternative for providing the multipoint connectivity normally provided by terrestrial audio bridge equipment The system that was implemented provides full mesh, full-duplex audio conferencing, with end-to-end voice paths between all participants requiring only a single hop (i.e. 250 msec. delay). Moreover, it addresses the lack of spontaneity in current systems by allowing a user to easily start a conference from any standard telephone handset connected to an ACTS earth station, and quickly add new members to the conference at any time using the 'hook flash' capability. No prior scheduling of resources is required and there is no central point of control, thereby providing the user with the spontaneity desired in audio conference control.

High-Resolution Measurement of the Turbulent Frequency-Wavenumber Power Spectrum in a Laboratory Magnetosphere

NASA Astrophysics Data System (ADS)

Qian, T. M.; Mauel, M. E.

2017-10-01

In a laboratory magnetosphere, plasma is confined by a strong dipole magnet, where interchange and entropy mode turbulence can be studied and controlled in near steady-state conditions. Whole-plasma imaging shows turbulence dominated by long wavelength modes having chaotic amplitudes and phases. Here, we report for the first time, high-resolution measurement of the frequency-wavenumber power spectrum by applying the method of Capon to simultaneous multi-point measurement of electrostatic entropy modes using an array of floating potential probes. Unlike previously reported measurements in which ensemble correlation between two probes detected only the dominant wavenumber, Capon's ``maximum likelihood method'' uses all available probes to produce a frequency-wavenumber spectrum, showing the existence of modes propagating in both electron and ion magnetic drift directions. We also discuss the wider application of this technique to laboratory and magnetospheric plasmas with simultaneous multi-point measurements. Supported by NSF-DOE Partnership in Plasma Science Grant DE-FG02-00ER54585.

Multidimensional directional flux weighted upwind scheme for multiphase flow modeling in heterogeneous porous media

NASA Astrophysics Data System (ADS)

Jin, G.

2012-12-01

Multiphase flow modeling is an important numerical tool for a better understanding of transport processes in the fields including, but not limited to, petroleum reservoir engineering, remedy of ground water contamination, and risk evaluation of greenhouse gases such as CO2 injected into deep saline reservoirs. However, accurate numerical modeling for multiphase flow remains many challenges that arise from the inherent tight coupling and strong non-linear nature of the governing equations and the highly heterogeneous media. The existence of counter current flow which is caused by the effect of adverse relative mobility contrast and gravitational and capillary forces will introduce additional numerical instability. Recently multipoint flux approximation (MPFA) has become a subject of extensive research and has been demonstrated with great success in reducing considerable grid orientation effects compared to the conventional single point upstream (SPU) weighting scheme, especially in higher dimensions. However, the present available MPFA schemes are mathematically targeted to certain types of grids in two dimensions, a more general form of MPFA scheme is needed for both 2-D and 3-D problems. In this work a new upstream weighting scheme based on multipoint directional incoming fluxes is proposed which incorporates full permeability tensor to account for the heterogeneity of the porous media. First, the multiphase governing equations are decoupled into an elliptic pressure equation and a hyperbolic or parabolic saturation depends on whether the gravitational and capillary pressures are presented or not. Next, a dual secondary grid (called finite volume grid) is formulated from a primary grid (called finite element grid) to create interaction regions for each grid cell over the entire simulation domain. Such a discretization must ensure the conservation of mass and maintain the continuity of the Darcy velocity across the boundaries between neighboring interaction regions. The pressure field is then implicitly calculated from the pressure equation, which in turn results in the derived velocity field for directional flux calculation at each grid node. Directional flux at the center of each interaction surface is also calculated by interpolation from the element nodal fluxes using shape functions. The MPFA scheme is performed by a specific linear combination of all incoming fluxes into the upstream cell represented by either nodal fluxes or interpolated surface boundary fluxes to produce an upwind directional fluxed weighted relative mobility at the center of the interaction region boundary. Such an upwind weighted relative mobility is then used for calculating the saturations of each fluid phase explicitly. The proposed upwind weighting scheme has been implemented into a mixed finite element-finite volume (FE-FV) method, which allows for handling complex reservoir geometry with second-order accuracies in approximating primary variables. The numerical solver has been tested with several bench mark test problems. The application of the proposed scheme to migration path analysis of CO2 injected into deep saline reservoirs in 3-D has demonstrated its ability and robustness in handling multiphase flow with adverse mobility contrast in highly heterogeneous porous media.

RECOVERING FILTER-BASED MICROARRAY DATA FOR PATHWAYS ANALYSIS USING A MULTIPOINT ALIGNMENT STRATEGY

EPA Science Inventory

The use of commercial microarrays are rapidly becoming the method of choice for profiling gene expression and assessing various disease states. Research Genetics has provided a series of well defined biological and software tools to the research community for these analyses. Th...

High pressure flow-rate switch

NASA Technical Reports Server (NTRS)

Gale, G. P.

1970-01-01

Flow-rate switch adjusts easily over a wide switching range and operates uniformly over many cycles. It adapts easily to control of various fluids and has the possibility of introducing multi-point switching. Novel design features include the tapered spool, balanced porting, capillary-bypass lubrication, and capillary-restriction damping.

Developing Telecommunication Linkages for Microcomputer-Aided Instruction. TDC Research Report No. 1.

ERIC Educational Resources Information Center

Blinn, Charles R.; And Others

A project undertaken at the University of Minnesota evaluated two microcomputer teletraining systems (audiographic conferencing) to determine the effectiveness of this technology for point-to-point and multipoint distance education. System design requirements included broadcast keystrokes, error checking, master-slave linkages, simultaneous voice…

Multidetector Scattering as a Probe of Local Structure in Disordered Phases

NASA Astrophysics Data System (ADS)

Clark, Noel A.; Ackerson, Bruce J.; Hurd, Alan J.

1983-05-01

The local translational structure of a two-dimensional colloidal liquid is observed by use of cross correlation of the intensity fluctuations of light scattered by the liquid through two different wave vectors. The utility of multidetector scattering in probing multipoint correlations in disordered phases is thereby demonstrated unambiguously.

Proceedings of the Workshop on Applications of Distributed System Theory to the Control of Large Space Structures

NASA Technical Reports Server (NTRS)

Rodriguez, G. (Editor)

1983-01-01

Two general themes in the control of large space structures are addressed: control theory for distributed parameter systems and distributed control for systems requiring spatially-distributed multipoint sensing and actuation. Topics include modeling and control, stabilization, and estimation and identification.

Optimization of connection techniques for multipoint satellite videoconference

NASA Astrophysics Data System (ADS)

Perrone, A.; Puccio, A.; Tirro, S.

1985-12-01

Videoconferencing is increasingly considered a convenient substitute for business travels, and satellites will remain for a long time the most convenient means for quick network implementation. The paper gives indications about the most promising connection and demand assignment techniques, and defines a possible protocol for information exchange among involved entities.

Methodologie de modelisation aerostructurelle d'une aile utilisant un logiciel de calcul aerodynamique et un logiciel de calcul par elements finis =

NASA Astrophysics Data System (ADS)

Communier, David

Lors de l'etude structurelle d'une aile d'avion, il est difficile de modeliser fidelement les forces aerodynamiques subies par l'aile de l'avion. Pour faciliter l'analyse, on repartit la portance maximale theorique de l'aile sur son longeron principal ou sur ses nervures. La repartition utilisee implique que l'aile entiere sera plus resistante que necessaire et donc que la structure ne sera pas totalement optimisee. Pour pallier ce probleme, il faudrait s'assurer d'appliquer une repartition aerodynamique de la portance sur la surface complete de l'aile. On serait donc en mesure d'obtenir une repartition des charges sur l'aile beaucoup plus fiable. Pour le realiser, nous aurons besoin de coupler les resultats d'un logiciel calculant les charges aerodynamiques de l'aile avec les resultats d'un logiciel permettant sa conception et son analyse structurelle. Dans ce projet, le logiciel utilise pour calculer les coefficients de pression sur l'aile est XFLR5 et le logiciel permettant la conception et l'analyse structurelle sera CATIA V5. Le logiciel XFLR5 permet une analyse rapide d'une aile en se basant sur l'analyse de ses profils. Ce logiciel calcule les performances des profils de la meme maniere que XFOIL et permet de choisir parmi trois methodes de calcul pour obtenir les performances de l'aile : Lifting Line Theory (LLT), Vortex Lattice Method (VLM) et 3D Panels. Dans notre methodologie, nous utilisons la methode de calcul 3D Panels dont la validite a ete testee en soufflerie pour confirmer les calculs sur XFLR5. En ce qui concerne la conception et l'analyse par des elements finis de la structure, le logiciel CATIA V5 est couramment utilise dans le domaine aerospatial. CATIA V5 permet une automatisation des etapes de conception de l'aile. Ainsi, dans ce memoire, nous allons decrire la methodologie permettant l'etude aerostructurelle d'une aile d'avion.

A National Satellite-Based System for Providing Continuing Education to Engineers.

ERIC Educational Resources Information Center

Georgia Inst. of Tech., Atlanta.

This document proposes, and indicates initial reaction to, a multi-point satellite-based delivery system which will permit expansion of current programs and services of the Association for Media-based Continuing Education for Engineers, Inc. (AMCEE) consortium to a much larger aggregated audience of practicing engineers throughout the country. It…

47 CFR 1.4000 - Restrictions impairing reception of television broadcast signals, direct broadcast satellite...

Code of Federal Regulations, 2011 CFR

2011-10-01

... antenna that is: (A) Used to receive video programming services via multipoint distribution services... radio, amateur (“HAM”) radio, Citizen's Band (CB) radio, and Digital Audio Radio Service (DARS) signals... reception of video programming services or devices used to receive or transmit fixed wireless signals shall...

76 FR 59559 - Facilitating the Use of Microwave for Wireless Backhaul and Other Uses and Providing Additional...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-27

...] Facilitating the Use of Microwave for Wireless Backhaul and Other Uses and Providing Additional Flexibility To... FS licensees to reduce operational costs, increase reliability, and facilitate the use of wireless... for wireless backhaul and other point-to-point and point-to-multipoint communications. We also make...

Genome-wide and fine-resolution association analysis of malaria in West Africa.

PubMed

Jallow, Muminatou; Teo, Yik Ying; Small, Kerrin S; Rockett, Kirk A; Deloukas, Panos; Clark, Taane G; Kivinen, Katja; Bojang, Kalifa A; Conway, David J; Pinder, Margaret; Sirugo, Giorgio; Sisay-Joof, Fatou; Usen, Stanley; Auburn, Sarah; Bumpstead, Suzannah J; Campino, Susana; Coffey, Alison; Dunham, Andrew; Fry, Andrew E; Green, Angela; Gwilliam, Rhian; Hunt, Sarah E; Inouye, Michael; Jeffreys, Anna E; Mendy, Alieu; Palotie, Aarno; Potter, Simon; Ragoussis, Jiannis; Rogers, Jane; Rowlands, Kate; Somaskantharajah, Elilan; Whittaker, Pamela; Widden, Claire; Donnelly, Peter; Howie, Bryan; Marchini, Jonathan; Morris, Andrew; SanJoaquin, Miguel; Achidi, Eric Akum; Agbenyega, Tsiri; Allen, Angela; Amodu, Olukemi; Corran, Patrick; Djimde, Abdoulaye; Dolo, Amagana; Doumbo, Ogobara K; Drakeley, Chris; Dunstan, Sarah; Evans, Jennifer; Farrar, Jeremy; Fernando, Deepika; Hien, Tran Tinh; Horstmann, Rolf D; Ibrahim, Muntaser; Karunaweera, Nadira; Kokwaro, Gilbert; Koram, Kwadwo A; Lemnge, Martha; Makani, Julie; Marsh, Kevin; Michon, Pascal; Modiano, David; Molyneux, Malcolm E; Mueller, Ivo; Parker, Michael; Peshu, Norbert; Plowe, Christopher V; Puijalon, Odile; Reeder, John; Reyburn, Hugh; Riley, Eleanor M; Sakuntabhai, Anavaj; Singhasivanon, Pratap; Sirima, Sodiomon; Tall, Adama; Taylor, Terrie E; Thera, Mahamadou; Troye-Blomberg, Marita; Williams, Thomas N; Wilson, Michael; Kwiatkowski, Dominic P

2009-06-01

We report a genome-wide association (GWA) study of severe malaria in The Gambia. The initial GWA scan included 2,500 children genotyped on the Affymetrix 500K GeneChip, and a replication study included 3,400 children. We used this to examine the performance of GWA methods in Africa. We found considerable population stratification, and also that signals of association at known malaria resistance loci were greatly attenuated owing to weak linkage disequilibrium (LD). To investigate possible solutions to the problem of low LD, we focused on the HbS locus, sequencing this region of the genome in 62 Gambian individuals and then using these data to conduct multipoint imputation in the GWA samples. This increased the signal of association, from P = 4 × 10(-7) to P = 4 × 10(-14), with the peak of the signal located precisely at the HbS causal variant. Our findings provide proof of principle that fine-resolution multipoint imputation, based on population-specific sequencing data, can substantially boost authentic GWA signals and enable fine mapping of causal variants in African populations.

Chemical improvement of chitosan-modified beads for the immobilization of Enterococcus faecium DBFIQ E36 L-arabinose isomerase through multipoint covalent attachment approach.

PubMed

Manzo, Ricardo M; de Sousa, Marylane; Fenoglio, Cecilia L; Gonçalves, Luciana Rocha Barro; Mammarella, Enrique J

2015-10-01

D-tagatose is produced from D-galactose by the enzyme L-arabinose isomerase (L-AI) in a commercially viable bioprocess. An active and stable biocatalyst was obtained by modifying chitosan gel structure through reaction with TNBS, D-fructose or DMF, among others. This led to a significant improvement in L-AI immobilization via multipoint covalent attachment approach. Synthetized derivatives were compared with commercial supports such as Eupergit(®) C250L and glyoxal-agarose. The best chitosan derivative for L-AI immobilization was achieved by reacting 4 % (w/v) D-fructose with 3 % (w/v) chitosan at 50 °C for 4 h. When compared to the free enzyme, the glutaraldehyde-activated chitosan biocatalyst showed an apparent activity of 88.4 U g (gel) (-1) with a 211-fold stabilization factor while the glyoxal-agarose biocatalyst gave an apparent activity of 161.8 U g (gel) (-1) with an 85-fold stabilization factor. Hence, chitosan derivatives were comparable to commercial resins, thus becoming a viable low-cost strategy to obtain high active L-AI insolubilized derivatives.

Evaluation of a multi-point method for determining acoustic impedance

NASA Technical Reports Server (NTRS)

Jones, Michael G.; Parrott, Tony L.

1988-01-01

An investigation was conducted to explore potential improvements provided by a Multi-Point Method (MPM) over the Standing Wave Method (SWM) and Two-Microphone Method (TMM) for determining acoustic impedance. A wave propagation model was developed to model the standing wave pattern in an impedance tube. The acoustic impedance of a test specimen was calculated from a best fit of this standing wave pattern to pressure measurements obtained along the impedance tube centerline. Three measurement spacing distributions were examined: uniform, random, and selective. Calculated standing wave patterns match the point pressure measurement distributions with good agreement for a reflection factor magnitude range of 0.004 to 0.999. Comparisons of results using 2, 3, 6, and 18 measurement points showed that the most consistent results are obtained when using at least 6 evenly spaced pressure measurements per half-wavelength. Also, data were acquired with broadband noise added to the discrete frequency noise and impedances were calculated using the MPM and TMM algorithms. The results indicate that the MPM will be superior to the TMM in the presence of significant broadband noise levels associated with mean flow.

A recoding scheme for X-linked and pseudoautosomal loci to be used with computer programs for autosomal LOD-score analysis.

PubMed

Strauch, Konstantin; Baur, Max P; Wienker, Thomas F

2004-01-01

We present a recoding scheme that allows for a parametric multipoint X-chromosomal linkage analysis of dichotomous traits in the context of a computer program for autosomes that can use trait models with imprinting. Furthermore, with this scheme, it is possible to perform a joint multipoint analysis of X-linked and pseudoautosomal loci. It is required that (1) the marker genotypes of all female nonfounders are available and that (2) there are no male nonfounders who have daughters in the pedigree. The second requirement does not apply if the trait locus is pseudoautosomal. The X-linked marker loci are recorded by adding a dummy allele to the males' hemizygous genotypes. For modelling an X-linked trait locus, five different liability classes are defined, in conjunction with a paternal imprinting model for male nonfounders. The formulation aims at the mapping of a diallelic trait locus relative to an arbitrary number of codominant markers with known genetic distances, in cases where a program for a genuine X-chromosomal analysis is not available. 2004 S. Karger AG, Basel.

A Self-Referencing Intensity-Based Fiber Optic Sensor with Multipoint Sensing Characteristics

PubMed Central

Choi, Sang-Jin; Kim, Young-Chon; Song, Minho; Pan, Jae-Kyung

2014-01-01

A self-referencing, intensity-based fiber optic sensor (FOS) is proposed and demonstrated. The theoretical analysis for the proposed design is given, and the validity of the theoretical analysis is confirmed via experiments. We define the measurement parameter, X, and the calibration factor, β, to find the transfer function, Hm,n, of the intensity-based FOS head. The self-referencing and multipoint sensing characteristics of the proposed system are validated by showing the measured Hm,n2 and relative error versus the optical power attenuation of the sensor head for four cases: optical source fluctuation, various remote sensing point distances, fiber Bragg gratings (FBGs) with different characteristics, and multiple sensor heads with cascade and/or parallel forms. The power-budget analysis and limitations of the measurement rates are discussed, and the measurement results of fiber-reinforced plastic (FRP) coupon strain using the proposed FOS are given as an actual measurement. The proposed FOS has several benefits, including a self-referencing characteristic, the flexibility to determine FBGs, and a simple structure in terms of the number of devices and measuring procedure. PMID:25046010

Multipoint study of interplanetary shocks

NASA Astrophysics Data System (ADS)

Blanco-Cano, Xochitl; Kajdic, Primoz; Russell, Christopher T.; Aguilar-Rodriguez, Ernesto; Jian, Lan K.; Luhmann, Janet G.

2016-04-01

Interplanetary (IP) shocks are driven in the heliosphere by Interplanetary Coronal Mass Ejections (ICMEs) and Stream Interaction Regions (SIRs). These shocks perturb the solar wind plasma, and play an active role in the acceleration of ions to suprathermal energies. Shock fronts evolve as they move from the Sun. Their surfaces can be far from uniform and be modulated by changes in the ambient solar wind (magnetic field orientation, flow velocity), shocks rippling, and perturbations upstream and downstream from the shocks, i.e., electromagnetic waves. In this work we use multipoint observations from STEREO, WIND, and MESSENGER missions to study shock characteristics at different helio-longitudes and determine the properties of the waves near them. We also determine shock longitudinal extensions and foreshock sizes. The variations of geometry along the shock surface can result in different extensions of the wave and ion foreshocks ahead of the shocks, and in different wave modes upstream and downtream of the shocks. We find that the ion foreshock can extend up to 0.2 AU ahead of the shock, and that the upstream region with modified solar wind/waves can be very asymmetric.

Multi-point laser coherent detection system and its application on vibration measurement

NASA Astrophysics Data System (ADS)

Fu, Y.; Yang, C.; Xu, Y. J.; Liu, H.; Yan, K.; Guo, M.

2015-05-01

Laser Doppler vibrometry (LDV) is a well-known interferometric technique to measure the motions, vibrations and mode shapes of machine components and structures. The drawback of commercial LDV is that it can only offer a pointwise measurement. In order to build up a vibrometric image, a scanning device is normally adopted to scan the laser point in two spatial axes. These scanning laser Doppler vibrometers (SLDV) assume that the measurement conditions remain invariant while multiple and identical, sequential measurements are performed. This assumption makes SLDVs impractical to do measurement on transient events. In this paper, we introduce a new multiple-point laser coherent detection system based on spatial-encoding technology and fiber configuration. A simultaneous vibration measurement on multiple points is realized using a single photodetector. A prototype16-point laser coherent detection system is built and it is applied to measure the vibration of various objects, such as body of a car or a motorcycle when engine is on and under shock tests. The results show the prospect of multi-point laser coherent detection system in the area of nondestructive test and precise dynamic measurement.

Multipoint Pressure and Temperature Sensing Fiber Optic Cable for Monitoring CO 2 Sequestration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Challener, William

2015-02-10

This report describes the work completed on contract DE-FE0010116. The goal of this two year project was to develop and demonstrate in the laboratory a highly accurate multi-point pressure measurement fiber optic cable based on MEMS pressure sensors suitable for downhole deployment in a CO 2 sequestration well. The sensor interrogator was also to be demonstrated in a remote monitoring system and environmental testing was to be completed to indicate its downhole survivability over a lengthy period of time (e.g., 20 years). An interrogator system based on a pulsed laser excitation was shown to be capable of multiple (potentially 100+)more » simultaneous sensor measurements. Two sensors packages were completed and spliced in a cable onto the same fiber and measured. One sensor package was subsequently measured at high temperatures and pressures in supercritical CO 2, while the other package was measured prior and after being subjected to high torque stresses to mimic downhole deployment. The environmental and stress tests indicated areas in which the package design should be further improved.« less

Parallel multipoint recording of aligned and cultured neurons on micro channel array toward cellular network analysis.

PubMed

Tonomura, Wataru; Moriguchi, Hiroyuki; Jimbo, Yasuhiko; Konishi, Satoshi

2010-08-01

This paper describes an advanced Micro Channel Array (MCA) for recording electrophysiological signals of neuronal networks at multiple points simultaneously. The developed MCA is designed for neuronal network analysis which has been studied by the co-authors using the Micro Electrode Arrays (MEA) system, and employs the principles of extracellular recordings. A prerequisite for extracellular recordings with good signal-to-noise ratio is a tight contact between cells and electrodes. The MCA described herein has the following advantages. The electrodes integrated around individual micro channels are electrically isolated to enable parallel multipoint recording. Reliable clamping of a targeted cell through micro channels is expected to improve the cellular selectivity and the attachment between the cell and the electrode toward steady electrophysiological recordings. We cultured hippocampal neurons on the developed MCA. As a result, the spontaneous and evoked spike potentials could be recorded by sucking and clamping the cells at multiple points. In this paper, we describe the design and fabrication of the MCA and the successful electrophysiological recordings leading to the development of an effective cellular network analysis device.

In vitro evaluation of flow patterns and turbulent kinetic energy in trans-catheter aortic valve prostheses.

PubMed

Giese, Daniel; Weiss, Kilian; Baeßler, Bettina; Madershahian, Navid; Choi, Yeong-Hoon; Maintz, David; Bunck, Alexander C

2018-02-01

The objective of the current work was to evaluate flow and turbulent kinetic energy in different transcatheter aortic valve implants using highly undersampled time-resolved multi-point 3-directional phase-contrast measurements (4D Flow MRI) in an in vitro setup. A pulsatile flow setup was used with a compliant tubing mimicking a stiff left ventricular outflow tract and ascending aorta. Five different implants were measured using a highly undersampled multi-point 4D Flow MRI sequence. Velocities and turbulent kinetic energy values were analysed and compared. Strong variations of turbulent kinetic energy distributions between the valves were observed. Maximum turbulent kinetic energy values ranged from 100 to over 500 J/m 3 while through-plane velocities were similar between all valves. Highly accelerated 4D Flow MRI for the measurement of velocities and turbulent kinetic energy values allowed for the assessment of hemodynamic parameters in five different implant models. The presented setup, measurement protocol and analysis methods provides an efficient approach to compare different valve implants and could aid future novel valve designs.

Automated in Situ Measurement of Gas Solubility in Liquids with a Simple Tube-in-Tube Reactor.

PubMed

Zhang, Jisong; Teixeira, Andrew R; Zhang, Haomiao; Jensen, Klavs F

2017-08-15

Data on the solubilities of gases in liquids are foundational for assessing a variety of multiphase separations and gas-liquid reactions. Taking advantage of the tube-in-tube reactor design built with semipermeable Teflon AF-2400 tubes, liquids can be rapidly saturated without direct contacting of gas and liquid. The gas solubility can be determined by performing steady-state flux balances of both the gas and liquid flowing into the reactor system. Using this type of reactor, a fully automated strategy has been developed for the rapid in situ measurement of gas solubilities in liquids. The developed strategy enables precise gas solubility measurements within 2-5 min compared with 4-5 h using conventional methods. This technique can be extended to the discrete multipoint steady-state and continuous ramped-multipoint data acquisition methods. The accuracy of this method has been validated against several gas-liquid systems, showing less than 2% deviation from known values. Finally, this strategy has been extended to measure the temperature dependence of gas solubilities in situ and to estimate the local enthalpy of dissolution across a defined temperature range.

Observations Regarding Use of Advanced CFD Analysis, Sensitivity Analysis, and Design Codes in MDO

NASA Technical Reports Server (NTRS)

Newman, Perry A.; Hou, Gene J. W.; Taylor, Arthur C., III

1996-01-01

Observations regarding the use of advanced computational fluid dynamics (CFD) analysis, sensitivity analysis (SA), and design codes in gradient-based multidisciplinary design optimization (MDO) reflect our perception of the interactions required of CFD and our experience in recent aerodynamic design optimization studies using CFD. Sample results from these latter studies are summarized for conventional optimization (analysis - SA codes) and simultaneous analysis and design optimization (design code) using both Euler and Navier-Stokes flow approximations. The amount of computational resources required for aerodynamic design using CFD via analysis - SA codes is greater than that required for design codes. Thus, an MDO formulation that utilizes the more efficient design codes where possible is desired. However, in the aerovehicle MDO problem, the various disciplines that are involved have different design points in the flight envelope; therefore, CFD analysis - SA codes are required at the aerodynamic 'off design' points. The suggested MDO formulation is a hybrid multilevel optimization procedure that consists of both multipoint CFD analysis - SA codes and multipoint CFD design codes that perform suboptimizations.

Space Technology 5 Multi-point Measurements of Near-Earth Magnetic Fields: Initial Results

NASA Technical Reports Server (NTRS)

Slavin, James A.; Le, G.; Strangeway, R. L.; Wang, Y.; Boardsen, S.A.; Moldwin, M. B.; Spence, H. E.

2007-01-01

The Space Technology 5 (ST-5) mission successfully placed three micro-satellites in a 300 x 4500 km dawn-dusk orbit on 22 March 2006. Each spacecraft carried a boom-mounted vector fluxgate magnetometer that returned highly sensitive and accurate measurements of the geomagnetic field. These data allow, for the first time, the separation of temporal and spatial variations in field-aligned current (FAC) perturbations measured in low-Earth orbit on time scales of approximately 10 sec to 10 min. The constellation measurements are used to directly determine field-aligned current sheet motion, thickness and current density. In doing so, we demonstrate two multi-point methods for the inference of FAC current density that have not previously been possible in low-Earth orbit; 1) the "standard method," based upon s/c velocity, but corrected for FAC current sheet motion, and 2) the "gradiometer method" which uses simultaneous magnetic field measurements at two points with known separation. Future studies will apply these methods to the entire ST-5 data set and expand to include geomagnetic field gradient analyses as well as field-aligned and ionospheric currents.

Research on atmospheric CO2 remote sensing with open-path tunable diode laser absorption spectroscopy and comparison methods

NASA Astrophysics Data System (ADS)

Xin, Fengxin; Guo, Jinjia; Sun, Jiayun; Li, Jie; Zhao, Chaofang; Liu, Zhishen

2017-06-01

An open-path atmospheric CO2 measurement system was built based on tunable diode laser absorption spectroscopy (TDLAS). The CO2 absorption line near 2 μm was selected, measuring the atmospheric CO2 with direct absorption spectroscopy and carrying on the comparative experiment with multipoint measuring instruments of the open-path. The detection limit of the TDLAS system is 1.94×10-6. The calibration experiment of three AZ-7752 handheld CO2 measuring instruments was carried out with the Los Gatos Research gas analyzer. The consistency of the results was good, and the handheld instrument could be used in the TDLAS system after numerical calibration. With the contrast of three AZ-7752 and their averages, the correlation coefficients are 0.8828, 0.9004, 0.9079, and 0.9393 respectively, which shows that the open-path TDLAS has the best correlation with the average of three AZ-7752 and measures the concentration of atmospheric CO2 accurately. Multipoint measurement provides a convenient comparative method for open-path TDLAS.

Investigating the use of multi-point coupling for single-sensor bearing estimation in one direction

NASA Astrophysics Data System (ADS)

Woolard, Americo G.; Phoenix, Austin A.; Tarazaga, Pablo A.

2018-04-01

Bearing estimation of radially propagating symmetric waves in solid structures typically requires a minimum of two sensors. As a test specimen, this research investigates the use of multi-point coupling to provide directional inference using a single-sensor. By this provision, the number of sensors required for localization can be reduced. A finite-element model of a beam is constructed with a symmetrically placed bipod that has asymmetric joint-stiffness properties. Impulse loading is applied at different points along the beam, and measurements are taken from the apex of the bipod. A technique is developed to determine the direction-of-arrival of the propagating wave. The accuracy when using the bipod with the developed technique is compared against results gathered without the bipod and measuring from an asymmetric location along the beam. The results show 92% accuracy when the bipod is used, compared to 75% when measuring without the bipod from an asymmetric location. A geometry investigation finds the best accuracy results when one leg of the bipod has a low stiffness and a large diameter relative to the other leg.

Evaluation of Pseudo-Haptic Interactions with Soft Objects in Virtual Environments.

PubMed

Li, Min; Sareh, Sina; Xu, Guanghua; Ridzuan, Maisarah Binti; Luo, Shan; Xie, Jun; Wurdemann, Helge; Althoefer, Kaspar

2016-01-01

This paper proposes a pseudo-haptic feedback method conveying simulated soft surface stiffness information through a visual interface. The method exploits a combination of two feedback techniques, namely visual feedback of soft surface deformation and control of the indenter avatar speed, to convey stiffness information of a simulated surface of a soft object in virtual environments. The proposed method was effective in distinguishing different sizes of virtual hard nodules integrated into the simulated soft bodies. To further improve the interactive experience, the approach was extended creating a multi-point pseudo-haptic feedback system. A comparison with regards to (a) nodule detection sensitivity and (b) elapsed time as performance indicators in hard nodule detection experiments to a tablet computer incorporating vibration feedback was conducted. The multi-point pseudo-haptic interaction is shown to be more time-efficient than the single-point pseudo-haptic interaction. It is noted that multi-point pseudo-haptic feedback performs similarly well when compared to a vibration-based feedback method based on both performance measures elapsed time and nodule detection sensitivity. This proves that the proposed method can be used to convey detailed haptic information for virtual environmental tasks, even subtle ones, using either a computer mouse or a pressure sensitive device as an input device. This pseudo-haptic feedback method provides an opportunity for low-cost simulation of objects with soft surfaces and hard inclusions, as, for example, occurring in ever more realistic video games with increasing emphasis on interaction with the physical environment and minimally invasive surgery in the form of soft tissue organs with embedded cancer nodules. Hence, the method can be used in many low-budget applications where haptic sensation is required, such as surgeon training or video games, either using desktop computers or portable devices, showing reasonably high fidelity in conveying stiffness perception to the user.

Empirical characteristics of family-based linkage to a complex trait: the ADIPOQ region and adiponectin levels.

PubMed

Hellwege, Jacklyn N; Palmer, Nicholette D; Mark Brown, W; Brown, Mark W; Ziegler, Julie T; Sandy An, S; An, Sandy S; Guo, Xiuqing; Ida Chen, Y-D; Chen, Ida Y-D; Taylor, Kent; Hawkins, Gregory A; Ng, Maggie C Y; Speliotes, Elizabeth K; Lorenzo, Carlos; Norris, Jill M; Rotter, Jerome I; Wagenknecht, Lynne E; Langefeld, Carl D; Bowden, Donald W

2015-02-01

We previously identified a low-frequency (1.1 %) coding variant (G45R; rs200573126) in the adiponectin gene (ADIPOQ) which was the basis for a multipoint microsatellite linkage signal (LOD = 8.2) for plasma adiponectin levels in Hispanic families. We have empirically evaluated the ability of data from targeted common variants, exome chip genotyping, and genome-wide association study data to detect linkage and association to adiponectin protein levels at this locus. Simple two-point linkage and association analyses were performed in 88 Hispanic families (1,150 individuals) using 10,958 SNPs on chromosome 3. Approaches were compared for their ability to map the functional variant, G45R, which was strongly linked (two-point LOD = 20.98) and powerfully associated (p value = 8.1 × 10(-50)). Over 450 SNPs within a broad 61 Mb interval around rs200573126 showed nominal evidence of linkage (LOD > 3) but only four other SNPs in this region were associated with p values < 1.0 × 10(-4). When G45R was accounted for, the maximum LOD score across the interval dropped to 4.39 and the best p value was 1.1 × 10(-5). Linked and/or associated variants ranged in frequency (0.0018-0.50) and type (coding, non-coding) and had little detectable linkage disequilibrium with rs200573126 (r (2) < 0.20). In addition, the two-point linkage approach empirically outperformed multipoint microsatellite and multipoint SNP analysis. In the absence of data for rs200573126, family-based linkage analysis using a moderately dense SNP dataset, including both common and low-frequency variants, resulted in stronger evidence for an adiponectin locus than association data alone. Thus, linkage analysis can be a useful tool to facilitate identification of high-impact genetic variants.

A Scalable, Parallel Approach for Multi-Point, High-Fidelity Aerostructural Optimization of Aircraft Configurations

NASA Astrophysics Data System (ADS)

Kenway, Gaetan K. W.

This thesis presents new tools and techniques developed to address the challenging problem of high-fidelity aerostructural optimization with respect to large numbers of design variables. A new mesh-movement scheme is developed that is both computationally efficient and sufficiently robust to accommodate large geometric design changes and aerostructural deformations. A fully coupled Newton-Krylov method is presented that accelerates the convergence of aerostructural systems and provides a 20% performance improvement over the traditional nonlinear block Gauss-Seidel approach and can handle more exible structures. A coupled adjoint method is used that efficiently computes derivatives for a gradient-based optimization algorithm. The implementation uses only machine accurate derivative techniques and is verified to yield fully consistent derivatives by comparing against the complex step method. The fully-coupled large-scale coupled adjoint solution method is shown to have 30% better performance than the segregated approach. The parallel scalability of the coupled adjoint technique is demonstrated on an Euler Computational Fluid Dynamics (CFD) model with more than 80 million state variables coupled to a detailed structural finite-element model of the wing with more than 1 million degrees of freedom. Multi-point high-fidelity aerostructural optimizations of a long-range wide-body, transonic transport aircraft configuration are performed using the developed techniques. The aerostructural analysis employs Euler CFD with a 2 million cell mesh and a structural finite element model with 300 000 DOF. Two design optimization problems are solved: one where takeoff gross weight is minimized, and another where fuel burn is minimized. Each optimization uses a multi-point formulation with 5 cruise conditions and 2 maneuver conditions. The optimization problems have 476 design variables are optimal results are obtained within 36 hours of wall time using 435 processors. The TOGW minimization results in a 4.2% reduction in TOGW with a 6.6% fuel burn reduction, while the fuel burn optimization resulted in a 11.2% fuel burn reduction with no change to the takeoff gross weight.

Effect of age and gender on the number of motor units in healthy subjects estimated by the multipoint incremental MUNE method.

PubMed

Gawel, Malgorzata; Kostera-Pruszczyk, Anna

2014-06-01

Motor unit number estimation (MUNE) is a tool for estimating the number of motor units. The aim was to evaluate the multipoint incremental MUNE method in a healthy population, to analyze whether aging, gender, and the dominant hand side influence the motor unit number, and to assess reproducibility of MUNE with the Shefner modification. We studied 60 volunteers (mean age, 47 ± 17.7 years) in four groups aged 18 to 30, 31 to 45, 46 to 60, and above 60 years. Motor unit number estimation was calculated in the abductor pollicis brevis (APB) and the abductor digiti minimi (ADM) by dividing the single motor unit action potential amplitude into the maximal compound motor action potential amplitude. Test-retest variability was 7%. The mean value of MUNE for APB was 133.2 ± 43 and for ADM was 157.1 ± 39.4. Significant differences in MUNE results were found between groups aged 18 to 30 and 60 years or older and between groups aged 31 to 45 and 60 years or older. Motor unit number estimation results correlated negatively with the age of subjects for both APB and ADM. Single motor unit action potential, reflecting the size of motor unit, increased with the age of subjects only in APB. Compound motor action potential amplitude correlated negatively with the age of subjects in APB and ADM. Significant correlations were seen between MUNE in APB or ADM and compound motor action potential amplitude in these muscles and the age of female subjects. A similar relationship was not found in males. Multipoint incremental MUNE method with the Shefner modification is a noninvasive, easy to perform method with high reproducibility. The loss of motor neurons because of aging could be confirmed by our MUNE study and seems to be more pronounced in females.

Spatial Expansion and Automation of the Pegasus Thomson Scattering Diagnostic System

NASA Astrophysics Data System (ADS)

Bodner, G. M.; Bongard, M. W.; Fonck, R. J.; Reusch, J. A.; Schlossberg, D. J.; Winz, G. R.

2015-11-01

The Pegasus Thomson scattering diagnostic system has recently undergone modifications to increase the spatial range of the diagnostic and automate the Thomson data collection process. Two multichannel spectrometers have been added to the original configuration, providing a total of 24 data channels to view the plasma volume. The new system configuration allows for observation of three distinct regions of the plasma: the local helicity injection (LHI) source (R ~ 67-73.8 cm), the plasma edge (R ~ 51.5-57.6 cm), and the plasma core (R ~ 35-41.1 cm). Each spectrometer utilizes a volume-phase holographic (VPH) grating and a gated-intensified CCD camera. The edge and the LHI spectrometers have been fitted with low-temperature VPH gratings to cover Te = 10 - 100 eV, while the core spectrometer has been fitted with a high-temperature VPH grating to cover Te = 0 . 1 - 1 . 0 keV. The additional spectrometers have been calibrated to account for detector flatness, detector linearity, and vignetting. Operation of the Thomson system has been overhauled to utilize LabVIEW software to synchronize the major components of the Thomson system with the Pegasus shot cycle and to provide intra-shot beam alignment. Multi-point Thomson scattering measurements will be obtained in the aforementioned regions of LHI and Ohmic discharges and will be compared to Langmuir probe measurements. Work supported by US DOE grant DE-FG02-96ER54375.

Review of modern low emissions combustion technologies for aero gas turbine engines

NASA Astrophysics Data System (ADS)

Liu, Yize; Sun, Xiaoxiao; Sethi, Vishal; Nalianda, Devaiah; Li, Yi-Guang; Wang, Lu

2017-10-01

Pollutant emissions from aircraft in the vicinity of airports and at altitude are of great public concern due to their impact on environment and human health. The legislations aimed at limiting aircraft emissions have become more stringent over the past few decades. This has resulted in an urgent need to develop low emissions combustors in order to meet legislative requirements and reduce the impact of civil aviation on the environment. This article provides a comprehensive review of low emissions combustion technologies for modern aero gas turbines. The review considers current high Technologies Readiness Level (TRL) technologies including Rich-Burn Quick-quench Lean-burn (RQL), Double Annular Combustor (DAC), Twin Annular Premixing Swirler combustors (TAPS), Lean Direct Injection (LDI). It further reviews some of the advanced technologies at lower TRL. These include NASA multi-point LDI, Lean Premixed Prevaporised (LPP), Axially Staged Combustors (ASC) and Variable Geometry Combustors (VGC). The focus of the review is placed on working principles, a review of the key technologies (includes the key technology features, methods of realising the technology, associated technology advantages and design challenges, progress in development), technology application and emissions mitigation potential. The article concludes the technology review by providing a technology evaluation matrix based on a number of combustion performance criteria including altitude relight auto-ignition flashback, combustion stability, combustion efficiency, pressure loss, size and weight, liner life and exit temperature distribution.

Spacecraft Fire Suppression: Testing and Evaluation

NASA Technical Reports Server (NTRS)

Abbud-Madrid, Angel; McKinnon, J. Thomas; Delplanque, Jean-Pierre; Kailasanath, Kazhikathra; Gokoglu, Suleyman; Wu, Ming-Shin

2004-01-01

The objective of this project is the testing and evaluation of the effectiveness of a variety of fire suppressants and fire-response techniques that will be used in the next generation of spacecraft (Crew Exploration Vehicle, CEV) and planetary habitats. From the many lessons learned in the last 40 years of space travel, there is common agreement in the spacecraft fire safety community that a new fire suppression system will be needed for the various types of fire threats anticipated in new space vehicles and habitats. To date, there is no single fire extinguishing system that can address all possible fire situations in a spacecraft in an effective, reliable, clean, and safe way. The testing conducted under this investigation will not only validate the various numerical models that are currently being developed, but it will provide new design standards on fire suppression that can then be applied to the next generation of spacecraft extinguishment systems. The test program will provide validation of scaling methods by conducting small, medium, and large scale fires. A variety of suppression methods will be tested, such as water mist, carbon dioxide, and nitrogen with single and multiple injection points and direct or distributed agent deployment. These injection methods cover the current ISS fire suppression method of a portable hand-held fire extinguisher spraying through a port in a rack and also next generation spacecraft units that may have a multi-point suppression delivery system built into the design. Consideration will be given to the need of a crew to clean-up the agent and recharge the extinguishers in flight in a long-duration mission. The fire suppression methods mentioned above will be used to extinguish several fire scenarios that have been identified as the most relevant to spaceflight, such as overheated wires, cable bundles, and circuit boards, as well as burning cloth and paper. Further testing will be conducted in which obstructions and ventilation will be added to represent actual spacecraft conditions (e.g., a series of cards in a card rack).

Connecting Land-Based Networks to Ships

DTIC Science & Technology

2013-06-01

multipoint wireless broadband systems, and WiMAX networks were initially deployed for fixed and nomadic (portable) applications. These standards...CAPABILITIES OF SHIP-TO-SHORE COMMUNICATIONS A. US Navy Automated Digital Network System (ADNS) The U.S. Navy’s Automated Digital Network System (ADNS...submit digitally any necessary documents to the terminal operators, contact their logistics providers, access tidal information and receive

Antibacterial activity of four mouthrinses containing triclosan against salivary Staphylococcus aureus

PubMed Central

Tanomaru, Juliane Maria Guerreiro; Nascimento, Andresa Piacezzi; Watanabe, Evandro; Matoba-Júnior, Fumio; Tanomaru-Filho, Mário; Ito, Izabel Yoko

2008-01-01

The maximum inhibitory dilution (MID) of triclosan-based mouthwashes against 28 Staphylococcus aureus strains was evaluated. Dilutions ranging from 1/10 to 1/655,360 were prepared. Strains were inoculated using a Steers multipoint inoculator. The MID was considered as the maximum dilution capable of inhibiting microorganism growth. The mouthwashes presented different MIDs. PMID:24031267

Antibacterial activity of four mouthrinses containing triclosan against salivary Staphylococcus aureus.

PubMed

Tanomaru, Juliane Maria Guerreiro; Nascimento, Andresa Piacezzi; Watanabe, Evandro; Matoba-Júnior, Fumio; Tanomaru-Filho, Mário; Ito, Izabel Yoko

2008-07-01

The maximum inhibitory dilution (MID) of triclosan-based mouthwashes against 28 Staphylococcus aureus strains was evaluated. Dilutions ranging from 1/10 to 1/655,360 were prepared. Strains were inoculated using a Steers multipoint inoculator. The MID was considered as the maximum dilution capable of inhibiting microorganism growth. The mouthwashes presented different MIDs.

Perturbative Yang-Mills theory without Faddeev-Popov ghost fields

NASA Astrophysics Data System (ADS)

Huffel, Helmuth; Markovic, Danijel

2018-05-01

A modified Faddeev-Popov path integral density for the quantization of Yang-Mills theory in the Feynman gauge is discussed, where contributions of the Faddeev-Popov ghost fields are replaced by multi-point gauge field interactions. An explicit calculation to O (g2) shows the equivalence of the usual Faddeev-Popov scheme and its modified version.

75 FR 26743 - Pacific Gas and Electric Company; Notice of Environmental Site Review and Technical Meetings To...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-12

... Ocean, 2.5 to 3.0 nautical miles west of Manila on Samoa Peninsula of Humboldt Bay, near Eureka... Conversion devises (WEC), including multi-point catenary moorings and anchors; (2) marker buoys, navigation... interconnection to the electrical grid; and (6) appurtenant facilities. WEC types that may be installed may...

76 FR 78922 - Information Collections Being Reviewed by the Federal Communications Commission Under Delegated...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-20

...: This filing is the application for a Cable Television Relay Service (CARS) microwave radio license. Franchised cable systems and other eligible services use the 2, 7, 12 and 18 GHz CARS bands for microwave... of the river or mountain) or many points (``multipoint'') via microwave. The filing is done for an...

Item Estimates under Low-Stakes Conditions: How Should Omits Be Treated?

ERIC Educational Resources Information Center

DeMars, Christine

Using data from a pilot test of science and math from students in 30 high schools, item difficulties were estimated with a one-parameter model (partial-credit model for the multi-point items). Some items were multiple-choice items, and others were constructed-response items (open-ended). Four sets of estimates were obtained: estimates for males…

Charge Transport in Carbon Nanotubes-Polymer Composite Photovoltaic Cells

PubMed Central

Ltaief, Adnen; Bouazizi, Abdelaziz; Davenas, Joel

2009-01-01

We investigate the dark and illuminated current density-voltage (J/V) characteristics of poly(2-methoxy-5-(2’-ethylhexyloxy)1-4-phenylenevinylene) (MEH-PPV)/single-walled carbon nanotubes (SWNTs) composite photovoltaic cells. Using an exponential band tail model, the conduction mechanism has been analysed for polymer only devices and composite devices, in terms of space charge limited current (SCLC) conduction mechanism, where we determine the power parameters and the threshold voltages. Elaborated devices for MEH-PPV:SWNTs (1:1) composites showed a photoresponse with an open-circuit voltage Voc of 0.4 V, a short-circuit current density JSC of 1 µA/cm² and a fill factor FF of 43%. We have modelised the organic photovoltaic devices with an equivalent circuit, where we calculated the series and shunt resistances.

LLR data analysis and impact on lunar dynamics from recent developments at OCA LLR Station

NASA Astrophysics Data System (ADS)

Viswanathan, Vishnu; Fienga, Agnes; Courde, Clement; Torre, Jean-Marie; Exertier, Pierre; Samain, Etienne; Feraudy, Dominique; Albanese, Dominique; Aimar, Mourad; Mariey, Hervé; Viot, Hervé; Martinot-Lagarde, Gregoire

2016-04-01

Since late 2014, OCA LLR station has been able to range with infrared wavelength (1064nm). IR ranging provides both temporal and spatial improvement in the LLR observations. IR detection also permits in densification of normal points, including the L1 and L2 retroreflectors due to better signal to noise ratio. This contributes to a better modelisation of the lunar libration. The hypothesis of lunar dust and environmental effects due to the chromatic behavior noticed on returns from L2 retroreflector is discussed. In addition, data analysis shows that the effect of retroreflector tilt and the use of calibration profile for the normal point deduction algorithm, contributes to improving the precision of normal points, thereby impacting lunar dynamical models and inner physics.

Turbulent scaling laws as solutions of the multi-point correlation equation using statistical symmetries

NASA Astrophysics Data System (ADS)

Oberlack, Martin; Rosteck, Andreas; Avsarkisov, Victor

2013-11-01

Text-book knowledge proclaims that Lie symmetries such as Galilean transformation lie at the heart of fluid dynamics. These important properties also carry over to the statistical description of turbulence, i.e. to the Reynolds stress transport equations and its generalization, the multi-point correlation equations (MPCE). Interesting enough, the MPCE admit a much larger set of symmetries, in fact infinite dimensional, subsequently named statistical symmetries. Most important, theses new symmetries have important consequences for our understanding of turbulent scaling laws. The symmetries form the essential foundation to construct exact solutions to the infinite set of MPCE, which in turn are identified as classical and new turbulent scaling laws. Examples on various classical and new shear flow scaling laws including higher order moments will be presented. Even new scaling have been forecasted from these symmetries and in turn validated by DNS. Turbulence modellers have implicitly recognized at least one of the statistical symmetries as this is the basis for the usual log-law which has been employed for calibrating essentially all engineering turbulence models. An obvious conclusion is to generally make turbulence models consistent with the new statistical symmetries.

Model-Based Linkage Analysis of a Quantitative Trait.

PubMed

Song, Yeunjoo E; Song, Sunah; Schnell, Audrey H

2017-01-01

Linkage Analysis is a family-based method of analysis to examine whether any typed genetic markers cosegregate with a given trait, in this case a quantitative trait. If linkage exists, this is taken as evidence in support of a genetic basis for the trait. Historically, linkage analysis was performed using a binary disease trait, but has been extended to include quantitative disease measures. Quantitative traits are desirable as they provide more information than binary traits. Linkage analysis can be performed using single-marker methods (one marker at a time) or multipoint (using multiple markers simultaneously). In model-based linkage analysis the genetic model for the trait of interest is specified. There are many software options for performing linkage analysis. Here, we use the program package Statistical Analysis for Genetic Epidemiology (S.A.G.E.). S.A.G.E. was chosen because it also includes programs to perform data cleaning procedures and to generate and test genetic models for a quantitative trait, in addition to performing linkage analysis. We demonstrate in detail the process of running the program LODLINK to perform single-marker analysis, and MLOD to perform multipoint analysis using output from SEGREG, where SEGREG was used to determine the best fitting statistical model for the trait.

Intercontinental Multi-Domain Monitoring for LHC with perfSONAR

NASA Astrophysics Data System (ADS)

Vicinanza, D.

2012-12-01

The Large Hadron Collider (LHC) is currently running at CERN in Geneva, Switzerland. Physicists are using LHC to recreate the conditions just after the Big Bang, by colliding two beams of particles and heavy ions head-on at very high energy. The project is generating more than 15 TB of raw data per year, plus 10 TB of “event summary data”. This data is sent out from CERN to eleven Tier 1 research centres in Europe, Asia, and North America using a multi-gigabits Optical Private Network (OPN), the LHCOPN. Tier 1 sites are then connected to 100+ academic and research institutions in the world (the Tier 2s) through a Multipoint to Multipoint network, the LHC Open Network Environment (LHCONE). Network monitoring on such complex network architecture to ensure robust and reliable operation is of crucial importance. The chosen approach for monitoring the OPN and ONE is based on the perfSONAR framework, which is designed for multi-domain monitoring environments. perfSONAR (www.perfsonar.net) is an infrastructure for performance monitoring data exchange between networks, making it easier to solve performance problems occurring between network measurement points interconnected through several network domains.

Developing a multipoint titration method with a variable dose implementation for anaerobic digestion monitoring.

PubMed

Salonen, K; Leisola, M; Eerikäinen, T

2009-01-01

Determination of metabolites from an anaerobic digester with an acid base titration is considered as superior method for many reasons. This paper describes a practical at line compatible multipoint titration method. The titration procedure was improved by speed and data quality. A simple and novel control algorithm for estimating a variable titrant dose was derived for this purpose. This non-linear PI-controller like algorithm does not require any preliminary information from sample. Performance of this controller is superior compared to traditional linear PI-controllers. In addition, simplification for presenting polyprotic acids as a sum of multiple monoprotic acids is introduced along with a mathematical error examination. A method for inclusion of the ionic strength effect with stepwise iteration is shown. The titration model is presented with matrix notations enabling simple computation of all concentration estimates. All methods and algorithms are illustrated in the experimental part. A linear correlation better than 0.999 was obtained for both acetate and phosphate used as model compounds with slopes of 0.98 and 1.00 and average standard deviations of 0.6% and 0.8%, respectively. Furthermore, insensitivity of the presented method for overlapping buffer capacity curves was shown.

Hydrolysis of tannic acid catalyzed by immobilized-stabilized derivatives of Tannase from Lactobacillus plantarum.

PubMed

Curiel, Jose Antonio; Betancor, Lorena; de las Rivas, Blanca; Muñoz, Rosario; Guisan, Jose M; Fernández-Lorente, Gloria

2010-05-26

A recombinant tannase from Lactobacillus plantarum , overexpressed in Escherichia coli , was purified in a single step by metal chelate affinity chromatography on poorly activated nickel supports. It was possible to obtain 0.9 g of a pure enzyme by using only 20 mL of chromatographic support. The pure enzyme was immobilized and stabilized by multipoint covalent immobilization on highly activated glyoxyl agarose. Derivatives obtained by multipoint and multisubunit immobilization were 500- and 1000-fold more stable than both the soluble enzyme and the one-point-immobilized enzyme in experiments of thermal and cosolvent inactivation, respectively. In addition, up to 70 mg of pure enzyme was immobilized on 1 g of wet support. The hydrolysis of tannic acid was optimized by using the new immobilized tannase derivative. The optimal reaction conditions were 30% diglyme at pH 5.0 and 4 degrees C. Under these conditions, it was possible to obtain 47.5 mM gallic acid from 5 mM tannic acid as substrate. The product was pure as proved by HPLC. On the other hand, the immobilized biocatalyst preserved >95% of its initial activity after 1 month of incubation under the optimal reaction conditions.

Development of a Multi-Point Microwave Interferometry (MPMI) Method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Specht, Paul Elliott; Cooper, Marcia A.; Jilek, Brook Anton

2015-09-01

A multi-point microwave interferometer (MPMI) concept was developed for non-invasively tracking a shock, reaction, or detonation front in energetic media. Initially, a single-point, heterodyne microwave interferometry capability was established. The design, construction, and verification of the single-point interferometer provided a knowledge base for the creation of the MPMI concept. The MPMI concept uses an electro-optic (EO) crystal to impart a time-varying phase lag onto a laser at the microwave frequency. Polarization optics converts this phase lag into an amplitude modulation, which is analyzed in a heterodyne interfer- ometer to detect Doppler shifts in the microwave frequency. A version of themore » MPMI was constructed to experimentally measure the frequency of a microwave source through the EO modulation of a laser. The successful extraction of the microwave frequency proved the underlying physical concept of the MPMI design, and highlighted the challenges associated with the longer microwave wavelength. The frequency measurements made with the current equipment contained too much uncertainty for an accurate velocity measurement. Potential alterations to the current construction are presented to improve the quality of the measured signal and enable multiple accurate velocity measurements.« less

A Novel Form of “Central Pouchlike” Cataract, with Sutural Opacities, Maps to Chromosome 15q21-22

PubMed Central

Vanita; Singh, Jai Rup; Sarhadi, Virinder K.; Singh, Daljit; Reis, André; Rueschendorf, Franz; Becker-Follmann, Johannes; Jung, Martin; Sperling, Karl

2001-01-01

Congenital cataract is a clinically and genetically highly heterogeneous eye disorder, with autosomal dominant inheritance being most common. We investigated a large seven-generation family with 74 individuals affected by autosomal dominant congenital cataract (ADCC). The phenotype in this family can be described as “central pouchlike” cataract with sutural opacities, and it differs from the other mapped cataracts. We performed linkage analysis with microsatellite markers in this family and excluded the known candidate genes. A genomewide search revealed linkage to markers on chromosome 15, with a maximum two-point LOD score of 5.98 at θ=0 with marker D15S117. Multipoint analysis also gave a maximum LOD score of 5.98 at D15S117. Multipoint and haplotype analysis narrowed the cataract locus to a 10-cM region between markers D15S209 and D15S1036, closely linked to marker D15S117 in q21-q22 region of chromosome 15. This is the first report of a gene for a clinically new type of ADCC at 15q21-22 locus. PMID:11133359

An ultra-small, multi-point, and multi-color photo-detection system with high sensitivity and high dynamic range.

PubMed

Anazawa, Takashi; Yamazaki, Motohiro

2017-12-05

Although multi-point, multi-color fluorescence-detection systems are widely used in various sciences, they would find wider applications if they are miniaturized. Accordingly, an ultra-small, four-emission-point and four-color fluorescence-detection system was developed. Its size (space between emission points and a detection plane) is 15 × 10 × 12 mm, which is three-orders-of-magnitude smaller than that of a conventional system. Fluorescence from four emission points with an interval of 1 mm on the same plane was respectively collimated by four lenses and split into four color fluxes by four dichroic mirrors. Then, a total of sixteen parallel color fluxes were directly input into an image sensor and simultaneously detected. The emission-point plane and the detection plane (the image-sensor surface) were parallel and separated by a distance of only 12 mm. The developed system was applied to four-capillary array electrophoresis and successfully achieved Sanger DNA sequencing. Moreover, compared with a conventional system, the developed system had equivalent high fluorescence-detection sensitivity (lower detection limit of 17 pM dROX) and 1.6-orders-of-magnitude higher dynamic range (4.3 orders of magnitude).

New method for determining central axial orientation of flux rope embedded within current sheet using multipoint measurements

NASA Astrophysics Data System (ADS)

Li, ZhaoYu; Chen, Tao; Yan, GuangQing

2016-10-01

A new method for determining the central axial orientation of a two-dimensional coherent magnetic flux rope (MFR) via multipoint analysis of the magnetic-field structure is developed. The method is devised under the following geometrical assumptions: (1) on its cross section, the structure is left-right symmetric; (2) the projected structure velocity is vertical to the line of symmetry. The two conditions can be naturally satisfied for cylindrical MFRs and are expected to be satisfied for MFRs that are flattened within current sheets. The model test demonstrates that, for determining the axial orientation of such structures, the new method is more efficient and reliable than traditional techniques such as minimum-variance analysis of the magnetic field, Grad-Shafranov (GS) reconstruction, and the more recent method based on the cylindrically symmetric assumption. A total of five flux transfer events observed by Cluster are studied using the proposed approach, and the application results indicate that the observed structures, regardless of their actual physical properties, fit the assumed geometrical model well. For these events, the inferred axial orientations are all in excellent agreement with those obtained using the multi-GS reconstruction technique.

Multishaker modal testing

NASA Technical Reports Server (NTRS)

Craig, R. R., Jr.

1983-01-01

Procedures for improving the modal modeling of structures using test data and to determine appropriate analytical models based on substructure experimental data were explored. Two related research topics were considered in modal modeling: using several independently acquired columns of frequency response data, and modal modeling using simultaneous multi-point excitation. In component mode synthesis modeling, the emphasis is on determining the best way to employ complex modes and residuals.

Erratum: “Multi-point, high-speed passive ion velocity distribution diagnostic on the Pegasus Toroidal Experiment” [Rev. Sci. Instrum. 83, 10D516 (2012)

DOE PAGES

Burke, Marcus G.; Fonck, Raymond J.; Bongard, Michael W.; ...

2016-07-18

This article corrects an error in M.G. Burke et al., 'Multi-point, high-speed passive ion velocity distribution diagnostic on the Pegasus Toroidal Experiment,' Rev. Sci. Instrum. 83, 10D516 (2012) pertaining to ion temperature. The conclusions of this paper are not altered by the revised ion temperature measurements.

Transport induced by large scale convective structures in a dipole-confined plasma.

PubMed

Grierson, B A; Mauel, M E; Worstell, M W; Klassen, M

2010-11-12

Convective structures characterized by E×B motion are observed in a dipole-confined plasma. Particle transport rates are calculated from density dynamics obtained from multipoint measurements and the reconstructed electrostatic potential. The calculated transport rates determined from the large-scale dynamics and local probe measurements agree in magnitude, show intermittency, and indicate that the particle transport is dominated by large-scale convective structures.

Statistical symmetries of the Lundgren-Monin-Novikov hierarchy.

PubMed

Wacławczyk, Marta; Staffolani, Nicola; Oberlack, Martin; Rosteck, Andreas; Wilczek, Michael; Friedrich, Rudolf

2014-07-01

It was shown by Oberlack and Rosteck [Discr. Cont. Dyn. Sys. S, 3, 451 2010] that the infinite set of multipoint correlation (MPC) equations of turbulence admits a considerable extended set of Lie point symmetries compared to the Galilean group, which is implied by the original set of equations of fluid mechanics. Specifically, a new scaling group and an infinite set of translational groups of all multipoint correlation tensors have been discovered. These new statistical groups have important consequences for our understanding of turbulent scaling laws as they are essential ingredients of, e.g., the logarithmic law of the wall and other scaling laws, which in turn are exact solutions of the MPC equations. In this paper we first show that the infinite set of translational groups of all multipoint correlation tensors corresponds to an infinite dimensional set of translations under which the Lundgren-Monin-Novikov (LMN) hierarchy of equations for the probability density functions (PDF) are left invariant. Second, we derive a symmetry for the LMN hierarchy which is analogous to the scaling group of the MPC equations. Most importantly, we show that this symmetry is a measure of the intermittency of the velocity signal and the transformed functions represent PDFs of an intermittent (i.e., turbulent or nonturbulent) flow. Interesting enough, the positivity of the PDF puts a constraint on the group parameters of both shape and intermittency symmetry, leading to two conclusions. First, the latter symmetries may no longer be Lie group as under certain conditions group properties are violated, but still they are symmetries of the LMN equations. Second, as the latter two symmetries in its MPC versions are ingredients of many scaling laws such as the log law, the above constraints implicitly put weak conditions on the scaling parameter such as von Karman constant κ as they are functions of the group parameters. Finally, let us note that these kind of statistical symmetries are of much more general type, i.e., not limited to MPC or PDF equations emerging from Navier-Stokes, but instead they are admitted by other nonlinear partial differential equations like, for example, the Burgers equation when in conservative form and if the nonlinearity is quadratic.

Nonlinear inversion of potential-field data using a hybrid-encoding genetic algorithm

USGS Publications Warehouse

Chen, C.; Xia, J.; Liu, J.; Feng, G.

2006-01-01

Using a genetic algorithm to solve an inverse problem of complex nonlinear geophysical equations is advantageous because it does not require computer gradients of models or "good" initial models. The multi-point search of a genetic algorithm makes it easier to find the globally optimal solution while avoiding falling into a local extremum. As is the case in other optimization approaches, the search efficiency for a genetic algorithm is vital in finding desired solutions successfully in a multi-dimensional model space. A binary-encoding genetic algorithm is hardly ever used to resolve an optimization problem such as a simple geophysical inversion with only three unknowns. The encoding mechanism, genetic operators, and population size of the genetic algorithm greatly affect search processes in the evolution. It is clear that improved operators and proper population size promote the convergence. Nevertheless, not all genetic operations perform perfectly while searching under either a uniform binary or a decimal encoding system. With the binary encoding mechanism, the crossover scheme may produce more new individuals than with the decimal encoding. On the other hand, the mutation scheme in a decimal encoding system will create new genes larger in scope than those in the binary encoding. This paper discusses approaches of exploiting the search potential of genetic operations in the two encoding systems and presents an approach with a hybrid-encoding mechanism, multi-point crossover, and dynamic population size for geophysical inversion. We present a method that is based on the routine in which the mutation operation is conducted in the decimal code and multi-point crossover operation in the binary code. The mix-encoding algorithm is called the hybrid-encoding genetic algorithm (HEGA). HEGA provides better genes with a higher probability by a mutation operator and improves genetic algorithms in resolving complicated geophysical inverse problems. Another significant result is that final solution is determined by the average model derived from multiple trials instead of one computation due to the randomness in a genetic algorithm procedure. These advantages were demonstrated by synthetic and real-world examples of inversion of potential-field data. ?? 2005 Elsevier Ltd. All rights reserved.

Modification of SR-PSOX functions by multi-point mutations of basic amino acid residues.

PubMed

Liu, Weiwei; Yin, Lan; Dai, Yalei

2013-02-01

SR-PSOX can function as a scavenger receptor, a chemokine and an adhesion molecule, and it could be an interesting player in the formation of atherosclerotic lesions. Our previous studies demonstrated that basic amino acid residues in the chemokine domain of SR-PSOX are critical for its functions. In this study the combinations of the key basic amino acids in the chemokine domain of SR-PSOX have been identified. Five combinations of basic amino acid residues that may form conformational motif for SR-PSOX functions were selected for multi-point mutants. The double mutants of K61AR62A, R76AK79A, R82AH85A, and treble mutants of R76AR78AK79A, R78AR82AH85A were successfully constructed by replacing the combinations of two or three basic amino acid residues with alanine. After successful expression of these mutants on the cells, the functional studies showed that the cells expressing R76AK79A and R82AH85A mutants significantly increased the activity of oxLDL uptake compared with that of wild-type SR-PSOX. Meanwhile, the cells expressing R76AK79A mutant also dramatically enhanced the phagocytotic activity of SR-PSOX. However, the cells expressing the construct of combination of R78A mutation in R76AK79A or R82AH85A could abolish these effects. More interestingly, the adhesive activities were remarkably down regulated in the cells expressing the multi-point mutants respectively. This study revealed that some conformational motifs of basic amino acid residues, especially R76 with K79 in SR-PSOX, may form a common functional motif for its critical functions. R78 in SR-PSOX has the potential action to stabilize the function of oxLDL uptake and bacterial phagocytosis. The results obtained may provide new insight for the development of drug target of atherosclerosis. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Observational evidence of competing source, loss, and transport processes for relativistic electrons in Earth's outer radiation belt

NASA Astrophysics Data System (ADS)

Turner, Drew; Mann, Ian; Usanova, Maria; Rodriguez, Juan; Henderson, Mike; Angelopoulos, Vassilis; Morley, Steven; Claudepierre, Seth; Li, Wen; Kellerman, Adam; Boyd, Alexander; Kim, Kyung-Chan

Earth’s outer electron radiation belt is a region of extreme variability, with relativistic electron intensities changing by orders of magnitude over time scales ranging from minutes to years. Extreme variations of outer belt electrons ultimately result from the relative impacts of various competing source (and acceleration), loss, and transport processes. Most of these processes involve wave-particle interactions between outer belt electrons and different types of plasma waves in the inner magnetosphere, and in turn, the activity of these waves depends on different solar wind and magnetospheric driving conditions and thus can vary drastically from event to event. Using multipoint analysis with data from NASA’s Van Allen Probes, THEMIS, and SAMPEX missions, NOAA’s GOES and POES constellations, and ground-based observatories, we present results from case studies revealing how different source/acceleration and loss mechanisms compete during active periods to result in drastically different distributions of outer belt electrons. By using a combination of low-Earth orbiting and high-altitude-equatorial orbiting satellites, we briefly review how it is possible to get a much more complete picture of certain wave activity and electron losses over the full range of MLTs and L-shells throughout the radiation belt. We then show example cases highlighting the importance of particular mechanisms, including: substorm injections and whistler-mode chorus waves for the source and acceleration of relativistic electrons; magnetopause shadowing and wave-particle interactions with EMIC waves for sudden losses; and ULF wave activity for driving radial transport, a process which is important for redistributing relativistic electrons, contributing both to acceleration and loss processes. We show how relativistic electron enhancement events involve local acceleration that is consistent with wave-particle interactions between a seed population of 10s to 100s of keV electrons, with a source in the plasma sheet, and chorus waves. We show how sudden losses during outer belt dropout events are dominated at higher L-shells (L>~4) by magnetopause shadowing and outward radial transport, which is effective over the full ranges of energy and equatorial pitch angle of outer belt electrons, but at lower L-shells near the plasmapause, energy and pitch angle dependent losses can also occur and are consistent with rapid scattering by interactions between relativistic electrons and EMIC waves. We show cases demonstrating how these different processes occur simultaneously during active periods, with relative effects that vary as a function of L-shell and electron energy and pitch angle. Ultimately, our results highlight the complexity of competing source/acceleration, loss, and transport processes in Earth’s outer radiation belt and the necessity of using multipoint observations to disambiguate between them for future studies.

Automated soil gas monitoring chamber

DOEpatents

Edwards, Nelson T.; Riggs, Jeffery S.

2003-07-29

A chamber for trapping soil gases as they evolve from the soil without disturbance to the soil and to the natural microclimate within the chamber has been invented. The chamber opens between measurements and therefore does not alter the metabolic processes that influence soil gas efflux rates. A multiple chamber system provides for repetitive multi-point sampling, undisturbed metabolic soil processes between sampling, and an essentially airtight sampling chamber operating at ambient pressure.

Smart architecture for stable multipoint fiber Bragg grating sensor system

NASA Astrophysics Data System (ADS)

Yeh, Chien-Hung; Tsai, Ning; Zhuang, Yuan-Hong; Huang, Tzu-Jung; Chow, Chi-Wai; Chen, Jing-Heng; Liu, Wen-Fung

2017-12-01

In this work, we propose and investigate an intelligent fiber Bragg grating (FBG)-based sensor system in which the proposed stabilized and wavelength-tunable single-longitudinal-mode erbium-doped fiber laser can improve the sensing accuracy of wavelength-division-multiplexing multiple FBG sensors in a longer fiber transmission distance. Moreover, we also demonstrate the proposed sensor architecture to enhance the FBG capacity for sensing strain and temperature, simultaneously.

Noise Identification in a Hot Transonic Jet Using Low-Dimensional Methods

DTIC Science & Technology

2008-03-01

calibration between the nozzle static pressure (transducer) and total pressure ( pitot probe) reveals a nearly linear relationship between the two, exhibiting... rakes of hot-wires. Multi-point correlations of velocity components coupled with assumptions of homogeneity and periodicity in the jet flow flied...axisymmetric incompressible jet at one downstream position using an in-house designed rake of 138 hot-wires. The experiment was then carried out at multiple

Edison Demonstration of Smallsat Networks

NASA Technical Reports Server (NTRS)

Westley, Deborah; Martinez, Andres; Petro, Andrew

2015-01-01

The goal of NASA's Edison Demonstration of Smallsat Networks (EDSN) mission is to demonstrate interactive satellite swarms capable of collecting, exchanging and transmitting multi-point scientific measurements. Satellite swarms enable a wide array of scientific, commercial and academic research not achievable with a single satellite. The EDSN satellites are scheduled to be launched into space as secondary payloads on the first flight of the Super Strypi launch vehicle no earlier than Oct. 29, 2015.

KSC-06pd0259

NASA Image and Video Library

2005-12-27

VANDENBERG AIR FORCE BASE, CALIF. - Inside Orbital Sciences Building 1555 at Vandenberg Air Force Base in California, workers attach segments of the Pegasus XL rocket that will launch the Space Technology 5 spacecraft later this month. ST5 contains three micro-satellites that will be positioned in a "string of pearls" constellation to perform simultaneous multi-point measurements of the Earth's magnetic field using highly sensitive magnetometers. The scheduled launch date is Feb. 28.

Simultaneous and multi-point measurement of ammonia emanating from human skin surface for the estimation of whole body dermal emission rate.

PubMed

Furukawa, Shota; Sekine, Yoshika; Kimura, Keita; Umezawa, Kazuo; Asai, Satomi; Miyachi, Hayato

2017-05-15

Ammonia is one of the members of odor gases and a possible source of odor in indoor environment. However, little has been known on the actual emission rate of ammonia from the human skin surface. Then, this study aimed to estimate the whole-body dermal emission rate of ammonia by simultaneous and multi-point measurement of emission fluxes of ammonia employing a passive flux sampler - ion chromatography system. Firstly, the emission fluxes of ammonia were non-invasively measured for ten volunteers at 13 sampling positions set in 13 anatomical regions classified by Kurazumi et al. The measured emission fluxes were then converted to partial emission rates using the surface body areas estimated by weights and heights of volunteers and partial rates of 13 body regions. Subsequent summation of the partial emission rates provided the whole body dermal emission rate of ammonia. The results ranged from 2.9 to 12mgh -1 with an average of 5.9±3.2mgh -1 per person for the ten healthy young volunteers. The values were much greater than those from human breath, and thus the dermal emission of ammonia was found more significant odor source than the breath exhalation in indoor environment. Copyright © 2017 Elsevier B.V. All rights reserved.

Space Technology 5 Multi-Point Observations of Temporal Variability of Field-Aligned Currents

NASA Technical Reports Server (NTRS)

Le, Guan; Wang, Yongli; Slavin, James A.; Strangeway, Robert J.

2008-01-01

Space Technology 5 (ST5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from ST5. The data demonstrate that meso-scale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of approximately 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are approximately 1 min for meso-scale currents and approximately 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

Space Technology 5 Multi-point Observations of Field-aligned Currents: Temporal Variability of Meso-Scale Structures

NASA Technical Reports Server (NTRS)

Le, Guan; Wang, Yongli; Slavin, James A.; Strangeway, Robert J.

2007-01-01

Space Technology 5 (ST5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from ST5. The data demonstrate that meso-scale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of - 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are approx. 1 min for meso-scale currents and approx. 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

Space Technology 5 (ST-5) Multipoint Observations of Temporal and Spatial Variability of Field-Aligned Currents

NASA Technical Reports Server (NTRS)

Le, Guan

2010-01-01

Space Technology 5 (ST-5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from ST5. The data demonstrate that mesoscale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of about 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are about 1 min for meso-scale currents and about 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

Linkage analysis of idiopathic generalized epilepsy (IGE) and marker loci on chromosome 6p in families of patients with juvenile myocloni epilepsy: No evidence for an epilepsy locus in the HLA region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whitehouse, W.P.; Rees, M.; Curtis, D.

1993-09-01

Evidence for a locus (EJM1) in the HLA region of chromosome 6p predisposing to idiopathic generalized epilepsy (IGE) in the families of patients with juvenile myoclonic epilepsy (JME) has been obtained in two previous studies of separately ascertained groups of kindreds. Linkage analysis has been undertaken in a third set of 25 families including a patient with JME and at least one first-degree relative with IGE. Family members were typed for eight polymorphic loci on chromosome 6p: F13A, D6889, D6S109, D6S105, D6S10, C4B, DQA1/A2, and TCTE1. Pairwise and multipoint linkage analysis was carried out assuming autosomal dominant and autosomal recessivemore » inheritance and age-dependent high or low penetrance. No significant evidence in favor of linkage was obtained at any locus. Multipoint linkage analysis generated significant exclusion data (lod score < -2.0) at HLA and for a region 10-30 cM telomeric to HLA, the extent of which varied with the level of penetrance assumed. These observations indicate that genetic heterogeneity exists within this epilepsy phenotype. 39 refs., 4 figs., 2 tabs.« less

Green coconut fiber: a novel carrier for the immobilization of commercial laccase by covalent attachment for textile dyes decolourization.

PubMed

Cristóvão, Raquel O; Silvério, Sara C; Tavares, Ana P M; Brígida, Ana Iraidy S; Loureiro, José M; Boaventura, Rui A R; Macedo, Eugénia A; Coelho, Maria Alice Z

2012-09-01

Commercial laccase formulation was immobilized on modified green coconut fiber silanized with 3-glycidoxypropyltrimethoxysilane, aiming to achieve a cheap and effective biocatalyst. Two different strategies were followed: one point (pH 7.0) and multipoint (pH 10.0) covalent attachment. The influence of immobilization time on enzymatic activity and the final reduction with sodium borohydride were evaluated. The highest activities were achieved after 2 h of contact time in all situations. Commercial laccase immobilized at pH 7.0 was found to have higher activity and higher affinity to the substrate. However, the immobilization by multipoint covalent attachment improved the biocatalyst thermal stability at 50 °C, when compared to soluble enzyme and to the immobilized enzyme at pH 7.0. The Schiff's bases reduction by sodium borohydride, in spite of causing a decrease in enzyme activity, showed to contribute to the increase of operational stability through bonds stabilization. Finally, these immobilized enzymes showed high efficiency in the continuous decolourization of reactive textile dyes. In the first cycle, the decolourization is mainly due to dyes adsorption on the support. However, when working in successive cycles, the adsorption capacity of the support decreases (saturation) and the enzymatic action increases, indicating the applicability of this biocatalyst for textile wastewater treatment.

Examination of X chromosome markers in Rett syndrome: Exclusion mapping with a novel variation on multilocus linkage analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ellison, K.A.; Fill, C.P.; Terwililger, J.

Rett syndrome is a neurologic disorder characterized by early normal development followed by regression, acquired deceleration of head growth, autism, ataxia, and sterotypic hand movements. The exclusive occurrence of the syndrome in females and the occurrence of a few familial cases with inheritance through maternal lines suggest that this disorder is most likely secondary to a mutation on the X chromosome. To address this hypothesis and to identify candidate regions for the Rett syndrome gene locus, genotypic analysis was performed in two families with maternally related affected half-sisters by using 63 DNA markers from the X chromosome. Nineteen of themore » loci studied were chosen for multipoint linkage analysis because they have been previously genetically mapped using a large number of meioses from reference families. Using the exclusion criterion of a lod score less than [minus]2, the authors were able to exclude the region between the Duchenne muscular dystrophy locus and the DXS456 locus. This region extends from Xp21.2 to Xq21-q23. The use of the multipoint linkage analysis approach outlined in this study should allow the exclusion of additional regions of the X chromosome as new markers are analyzed.« less

High-spatial-resolution electron density measurement by Langmuir probe for multi-point observations using tiny spacecraft

NASA Astrophysics Data System (ADS)

Hoang, H.; Røed, K.; Bekkeng, T. A.; Trondsen, E.; Clausen, L. B. N.; Miloch, W. J.; Moen, J. I.

2017-11-01

A method for evaluating electron density using a single fixed-bias Langmuir probe is presented. The technique allows for high-spatio-temporal resolution electron density measurements, which can be effectively carried out by tiny spacecraft for multi-point observations in the ionosphere. The results are compared with the multi-needle Langmuir probe system, which is a scientific instrument developed at the University of Oslo comprising four fixed-bias cylindrical probes that allow small-scale plasma density structures to be characterized in the ionosphere. The technique proposed in this paper can comply with the requirements of future small-sized spacecraft, where the cost-effectiveness, limited space available on the craft, low power consumption and capacity for data-links need to be addressed. The first experimental results in both the plasma laboratory and space confirm the efficiency of the new approach. Moreover, detailed analyses on two challenging issues when deploying the DC Langmuir probe on a tiny spacecraft, which are the limited conductive area of the spacecraft and probe surface contamination, are presented in the paper. It is demonstrated that the limited conductive area, depending on applications, can either be of no concern for the experiment or can be resolved by mitigation methods. Surface contamination has a small impact on the performance of the developed probe.

Familial isolated hyperparathyroidism is linked to a 1.7 Mb region on chromosome 2p13.3–14

PubMed Central

Warner, J; Nyholt, D R; Busfield, F; Epstein, M; Burgess, J; Stranks, S; Hill, P; Perry‐Keene, D; Learoyd, D; Robinson, B; Teh, B T; Prins, J B; Cardinal, J W

2006-01-01

Bachground Familial isolated hyperparathyroidism (FIHP) is an autosomal dominantly inherited form of primary hyperparathyroidism. Although comprising only about 1% of cases of primary hyperparathyroidism, identification and functional analysis of a causative gene for FIHP is likely to advance our understanding of parathyroid physiology and pathophysiology. Methods A genome‐wide screen of DNA from seven pedigrees with FIHP was undertaken in order to identify a region of genetic linkage with the disorder. Results Multipoint linkage analysis identified a region of suggestive linkage (LOD score 2.68) on chromosome 2. Fine mapping with the addition of three other families revealed significant linkage adjacent to D2S2368 (maximum multipoint LOD score 3.43). Recombination events defined a 1.7 Mb region of linkage between D2S2368 and D2S358 in nine pedigrees. Sequencing of the two most likely candidate genes in this region, however, did not identify a gene for FIHP. Conclusions We conclude that a causative gene for FIHP lies within this interval on chromosome 2. This is a major step towards eventual precise identification of a gene for FIHP, likely to be a key component in the genetic regulation of calcium homeostasis. PMID:16525030

New spatial upscaling methods for multi-point measurements: From normal to p-normal

NASA Astrophysics Data System (ADS)

Liu, Feng; Li, Xin

2017-12-01

Careful attention must be given to determining whether the geophysical variables of interest are normally distributed, since the assumption of a normal distribution may not accurately reflect the probability distribution of some variables. As a generalization of the normal distribution, the p-normal distribution and its corresponding maximum likelihood estimation (the least power estimation, LPE) were introduced in upscaling methods for multi-point measurements. Six methods, including three normal-based methods, i.e., arithmetic average, least square estimation, block kriging, and three p-normal-based methods, i.e., LPE, geostatistics LPE and inverse distance weighted LPE are compared in two types of experiments: a synthetic experiment to evaluate the performance of the upscaling methods in terms of accuracy, stability and robustness, and a real-world experiment to produce real-world upscaling estimates using soil moisture data obtained from multi-scale observations. The results show that the p-normal-based methods produced lower mean absolute errors and outperformed the other techniques due to their universality and robustness. We conclude that introducing appropriate statistical parameters into an upscaling strategy can substantially improve the estimation, especially if the raw measurements are disorganized; however, further investigation is required to determine which parameter is the most effective among variance, spatial correlation information and parameter p.

Linkage to 10q22 for maximum intraocular pressure and 1p32 for maximum cup-to-disc ratio in an extended primary open-angle glaucoma pedigree.

PubMed

Charlesworth, Jac C; Dyer, Thomas D; Stankovich, Jim M; Blangero, John; Mackey, David A; Craig, Jamie E; Green, Catherine M; Foote, Simon J; Baird, Paul N; Sale, Michèle M

2005-10-01

The purpose of this study was to identify genetic contributions to primary open-angle glaucoma (POAG) through investigations of two quantitative components of the POAG phenotype. Genome-wide multipoint variance-components linkage analyses of maximum recorded intraocular pressure (IOP) and maximum vertical cup-to-disc ratio were conducted on data from a single, large Australian POAG pedigree that has been found to segregate the myocilin Q368X mutation in some individuals. Multipoint linkage analysis of maximum recorded IOP produced a peak LOD score of 3.3 (P = 0.00015) near marker D10S537 on 10q22, whereas the maximum cup-to-disc ratio produced a peak LOD score of 2.3 (P = 0.00056) near markers D1S197 to D1S220 on 1p32. Inclusion of the myocilin Q368X mutation as a covariate provided evidence of an interaction between this mutation and the IOP and cup-to-disc ratio loci. Significant linkage has been identified for maximum IOP and suggestive linkage for vertical cup-to-disc ratio. Identification of genes contributing to the variance of these traits will enhance understanding of the pathophysiology of POAG as a whole.

MLAOS: A Multi-Point Linear Array of Optical Sensors for Coniferous Foliage Clumping Index Measurement

PubMed Central

Qu, Yonghua; Fu, Lizhe; Han, Wenchao; Zhu, Yeqing; Wang, Jindi

2014-01-01

The canopy foliage clumping effect is primarily caused by the non-random distribution of canopy foliage. Currently, measurements of clumping index (CI) by handheld instruments is typically time- and labor-intensive. We propose a low-cost and low-power automatic measurement system called Multi-point Linear Array of Optical Sensors (MLAOS), which consists of three above-canopy and nine below-canopy optical sensors that capture plant transmittance at different times of the day. Data communication between the MLAOS node is facilitated by using a ZigBee network, and the data are transmitted from the field MLAOS to a remote data server using the Internet. The choice of the electronic element and design of the MLAOS software is aimed at reducing costs and power consumption. A power consumption test showed that, when a 4000 mAH Li-ion battery is used, a maximum of 8–10 months of work can be achieved. A field experiment on a coniferous forest revealed that the CI of MLAOS may reveal a clumping effect that occurs within the canopy. In further work, measurement of the multi-scale clumping effect can be achieved by utilizing a greater number of MLAOS devices to capture the heterogeneity of the plant canopy. PMID:24859029

Characterizing the spatio-temporal and energy-dependent response of riometer absorption to particle precipitation

NASA Astrophysics Data System (ADS)

Kellerman, Adam; Makarevich, Roman; Spanswick, Emma; Donovan, Eric; Shprits, Yuri

2016-07-01

Energetic electrons in the 10's of keV range precipitate to the upper D- and lower E-region ionosphere, and are responsible for enhanced ionization. The same particles are important in the inner magnetosphere, as they provide a source of energy for waves, and thus relate to relativistic electron enhancements in Earth's radiation belts.In situ observations of plasma populations and waves are usually limited to a single point, which complicates temporal and spatial analysis. Also, the lifespan of satellite missions is often limited to several years which does not allow one to infer long-term climatology of particle precipitation, important for affecting ionospheric conditions at high latitudes. Multi-point remote sensing of the ionospheric plasma conditions can provide a global view of both ionospheric and magnetospheric conditions, and the coupling between magnetospheric and ionospheric phenomena can be examined on time-scales that allow comprehensive statistical analysis. In this study we utilize multi-point riometer measurements in conjunction with in situ satellite data, and physics-based modeling to investigate the spatio-temporal and energy-dependent response of riometer absorption. Quantifying this relationship may be a key to future advancements in our understanding of the complex D-region ionosphere, and may lead to enhanced specification of auroral precipitation both during individual events and over climatological time-scales.

The autosomal dominant familial exudative vitreoretinopathy locus maps on 11q and is closely linked to D11S533

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yuen; Schwinger, D.; Gal, A.

1992-10-01

Autosomal dominant familial exudative vitreoretinopathy (adFEVR) is a hereditary disorder characterized by the incomplete vascularization of the peripheral retina. The primary biochemical defect in adFEVR is unknown. The adFEVR locus has tentatively been assigned to 11q by linkage studies. The authors report the results of an extended multipoint linkage analysis of two families with adFEVR by using five markers (INT2, D11S533, D11S527, D11S35, and CD3D) from 11q13-q23. Pairwise linkage data obtained in the two families were rather similar and hence have not provided evidence for genetic heterogeneity. The highest compiled two-point lod score (3.67, at a recombination fraction of .07)more » was obtained for the disease locus versus D11S533. Multipoint analyses showed that the adFEVR locus maps most likely, with a maximum location score of over 20, between D11S533/D11S526 and D11S35, at recombination rates of .147 and .104, respectively. Close linkage without recombination (maximum lod score 11.26) has been found between D11S533 and D11S526. 15 refs., 3 figs., 4 tabs.« less

Distributed optical fiber vibration sensor based on Sagnac interference in conjunction with OTDR.

PubMed

Pan, Chao; Liu, Xiaorui; Zhu, Hui; Shan, Xuekang; Sun, Xiaohan

2017-08-21

A real-time distributed optical fiber vibration sensing prototype based on the Sagnac interference in conjunction with the optical time domain reflectometry (OTDR) was developed. The sensing mechanism for single- and multi-points vibrations along the sensing fiber was analyzed theoretically and demonstrated experimentally. The experimental results show excellent agreement with the theoretical models. It is verified that single-point vibration induces a significantly abrupt and monotonous power change in the corresponding position of OTDR trace. As to multi-points vibrations, the detection of the following vibration is influenced by all previous ones. However, if the distance between the adjacent two vibrations is larger than half of the input optical pulse width, abrupt power changes induced by them are separate and still monotonous. A time-shifting differential module was developed and carried out to convert vibration-induced power changes to pulses. Consequently, vibrations can be located accurately by measuring peak or valley positions of the vibration-induced pulses. It is demonstrated that when the width and peak power of input optical pulse are set to 1 μs and 35 mW, respectively, the position error is less than ± 0.5 m in a sensing range of more than 16 km, with the spatial resolution of ~110 m.

The possibilities for mobile and fixed services up to the 20/30 GHz frequency bands

NASA Astrophysics Data System (ADS)

Hughes, Clifford D.; Feliciani, F.; Spiller, J.

Satellite Communications and broadcasting is presently in a period of considerable change. In the fixed service there is strong competition from terrestrial fiber optic systems which have virtually arrested the growth of the traditional satellite market for long distance high capacity communications. The satellite has however made considerable progress in areas where it has unique advantages; for example, in point to multipoint (broadcasting), multipoint to point (data collection) and generally in small terminal system applications where flexibility of deployment coupled with ease of installation are of importance. In the mobile service, in addition to the already established geostationary systems, there are numerous proposals for HEO, MEO and LEO systems. There are also several new frequency allocations as a result of the WARC 92 to be taken into account. At one extreme there are researchers working on Ka band 20/30 GHz mobile systems and there are other groups who foresee no future above the L-band frequency allocations. Amongst all these inputs it is difficult to see the direction in which development activities both for satellites and for earth segment should be focused. However, as an aid to understanding, this paper seeks to find some underlying relationships and to clarify some of the variables.

Target analyte quantification by isotope dilution LC-MS/MS directly referring to internal standard concentrations--validation for serum cortisol measurement.

PubMed

Maier, Barbara; Vogeser, Michael

2013-04-01

Isotope dilution LC-MS/MS methods used in the clinical laboratory typically involve multi-point external calibration in each analytical series. Our aim was to test the hypothesis that determination of target analyte concentrations directly derived from the relation of the target analyte peak area to the peak area of a corresponding stable isotope labelled internal standard compound [direct isotope dilution analysis (DIDA)] may be not inferior to conventional external calibration with respect to accuracy and reproducibility. Quality control samples and human serum pools were analysed in a comparative validation protocol for cortisol as an exemplary analyte by LC-MS/MS. Accuracy and reproducibility were compared between quantification either involving a six-point external calibration function, or a result calculation merely based on peak area ratios of unlabelled and labelled analyte. Both quantification approaches resulted in similar accuracy and reproducibility. For specified analytes, reliable analyte quantification directly derived from the ratio of peak areas of labelled and unlabelled analyte without the need for a time consuming multi-point calibration series is possible. This DIDA approach is of considerable practical importance for the application of LC-MS/MS in the clinical laboratory where short turnaround times often have high priority.

The possibilities for mobile and fixed services up to the 20/30 GHz frequency bands

NASA Technical Reports Server (NTRS)

Hughes, Clifford D.; Feliciani, F.; Spiller, J.

1993-01-01

Satellite Communications and broadcasting is presently in a period of considerable change. In the fixed service there is strong competition from terrestrial fiber optic systems which have virtually arrested the growth of the traditional satellite market for long distance high capacity communications. The satellite has however made considerable progress in areas where it has unique advantages; for example, in point to multipoint (broadcasting), multipoint to point (data collection) and generally in small terminal system applications where flexibility of deployment coupled with ease of installation are of importance. In the mobile service, in addition to the already established geostationary systems, there are numerous proposals for HEO, MEO and LEO systems. There are also several new frequency allocations as a result of the WARC 92 to be taken into account. At one extreme there are researchers working on Ka band 20/30 GHz mobile systems and there are other groups who foresee no future above the L-band frequency allocations. Amongst all these inputs it is difficult to see the direction in which development activities both for satellites and for earth segment should be focused. However, as an aid to understanding, this paper seeks to find some underlying relationships and to clarify some of the variables.

Freestream Effects on Boundary Layer Disturbances for HIFiRE-5 (Postprint)

DTIC Science & Technology

2015-01-01

hypersonic wind tunnel . For Mach 6.5 and 7, there was no evidence of traveling crossflow waves . However, higher-frequency disturbances were observed. These...disturbances. The structure of these disturbances (phase velocity and wave angle) is similar in both wind tunnels . Coherence measurements in the ACE show that...These include detailed mapping of disturbance fields in the wind tunnel , including higher-frequency measurements, multi-point probe mea- surements to

ICU Multipoint Military Pacific Consultation using Telehealth (IMMPACT)

DTIC Science & Technology

2010-05-01

the Leapfrog Group has found that mortality rates are up to 30 percent lower and lengths of stay ( LOS ) up to three days shorter in ICUs managed by...length of stay ( LOS ), the two key outcome measures for ICUs. Some hospitals report clinical improvements such as higher rates of survival from...compares patient outcomes before and after the installation of the Tele-ICU.5 Sentara found that mortality, LOS , and financial measures all improved

Refined genetic mapping of X-linked Charcot-Marie-Tooth neuropathy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fain, P.R.; Barker, D.F.; Chance, P.F.

1994-02-01

Genetic linkage studies were conducted in four multigenerational families with X-linked Charcot-Marie-Tooth disease (CMTX), using 12 highly polymorphic short-tandem-repeat markers for the pericentromeric region of the X Chromosome. Pairwise linkage analysis with individual markers confirmed tight linkage of CMTX to the pericentromeric region in each family. Multipoint analyses strongly support the order DXS337-CMTX-DXS441-(DXS56, PGK1). 38 refs., 2 figs., 1 tab.

Contribution to study of interfaces instabilities in plane, cylindrical and spherical geometry

NASA Astrophysics Data System (ADS)

Toque, Nathalie

1996-12-01

This thesis proposes several experiments of hydrodynamical instabilities which are studied, numerically and theoretically. The experiments are in plane and cylindrical geometry. Their X-ray radiographies show the evolution of an interface between two solid media crossed by a detonation wave. These materials are initially solid. They become liquide under shock wave or stay between two phases, solid and liquid. The numerical study aims at simulating with the codes EAD and Ouranos, the interfaces instabilities which appear in the experiments. The experimental radiographies and the numerical pictures are in quite good agreement. The theoretical study suggests to modelise a spatio-temporal part of the experiments to obtain the quantitative development of perturbations at the interfaces and in the flows. The models are linear and in plane, cylindrical and spherical geometry. They preceed the inoming study of transition between linear and non linear development of instabilities in multifluids flows crossed by shock waves.

Generation of 238U Covariance Matrices by Using the Integral Data Assimilation Technique of the CONRAD Code

NASA Astrophysics Data System (ADS)

Privas, E.; Archier, P.; Bernard, D.; De Saint Jean, C.; Destouche, C.; Leconte, P.; Noguère, G.; Peneliau, Y.; Capote, R.

2016-02-01

A new IAEA Coordinated Research Project (CRP) aims to test, validate and improve the IRDF library. Among the isotopes of interest, the modelisation of the 238U capture and fission cross sections represents a challenging task. A new description of the 238U neutrons induced reactions in the fast energy range is within progress in the frame of an IAEA evaluation consortium. The Nuclear Data group of Cadarache participates in this effort utilizing the 238U spectral indices measurements and Post Irradiated Experiments (PIE) carried out in the fast reactors MASURCA (CEA Cadarache) and PHENIX (CEA Marcoule). Such a collection of experimental results provides reliable integral information on the (n,γ) and (n,f) cross sections. This paper presents the Integral Data Assimilation (IDA) technique of the CONRAD code used to propagate the uncertainties of the integral data on the 238U cross sections of interest for dosimetry applications.

Electrode-Skin contact impedance: In vivo measurements on an ovine model

NASA Astrophysics Data System (ADS)

Nguyen, D. T.; Kosobrodov, R.; Barry, M. A.; Chik, W.; Jin, C.; Oh, T. I.; Thiagalingam, A.; McEwan, A.

2013-04-01

The problem of electrical impedance between the skin and the electrode is an on-going challenge in bio-electronics. This is particularly true in the case of Electrical Impedance Tomography (EIT), which uses a large number of skin-contact electrodes and is very sensitive to noise. In the present article, contact impedance is measured and compared for a range of electrodes placed on the thorax of an ovine model. The study has been approved by the Westmead Hospital Animal Ethics Committee. The electrode models that were employed in the research are Ag/AgCl electrodes (E1), commonly used for ECG and EIT measurements in both humans and animal models, stainless steel crocodile clips (E2), typically used on animal models, and novel multi-point dry electrodes in two modifications: bronze plated (E3) and nickel plated (E4). Further, since the contact impedance is mostly attributed to the acellular outer layer of the skin, in our experiment, we attempted to study the effect of this layer by comparing the results when the skin is intact and when electrodes are introduced underneath the skin through small cuts. This boundary effect was assessed by comparison of measurements obtained during E2 skin surface contact, and sub-cutaneous contact (E5). Twelve gauge intradermal needles were also tested as an electrode (E6). The full impedance spectrum, from 500 Hz to 300 kHz, was recorded, analysed and compared. As expected, the contact impedance in the more invasive cases, i.e the electrodes under the skin, is significantly lower than in the non-invasive cases. At the frequency of 50 kHz which is commonly used in lung EIT acquisition, electrodes E3, E4 and E6 demonstrated contact impedance of less than 200 Ω, compared to more than 400 Ω measured for electrodes E1, E2 and E5. In conclusion, the novel multipoint electrodes proved to be best suited for EIT purposes, because they are non-invasive and have lower contact impedance than Ag/AgCl and crocodile clips, in both invasive and non-invasive cases. This further prompted us to design a flexible electrode belt using the novel multi-point electrodes for lung EIT on animal models.

Plasma jets in the near-Earth's magnetotail (Julius Bartels Medal Lecture)

NASA Astrophysics Data System (ADS)

Nakamura, Rumi

2014-05-01

The Earth's magnetosphere is formed as a consequence of the interaction between the magnetized solar wind and the terrestrial magnetic field. While the large-scale and average (>hours) properties of the Earth's magnetotail current sheet can be well described by overall solar wind-magnetosphere interaction, the most dramatic energy conversion process takes place in an explosive manner involving transient (up to several minutes) and localized (up to a few RE) phenomena in the plasma sheet/current sheet regions. One of the most clear observables of such processes are the localized and transient plasma jets called Bursty bulk flows (BBF), embedding velocity peaks of 1-min duration, which are called flow bursts. This talk is a review of the current understanding of these plasma jets by highlighting the results from multi-spacecraft observations by the Cluster and THEMIS spacecraft. The first four-spacecraft mission Cluster crossed the near-Earth plasma sheet with inter-spacecraft distance of about 250 km to 10000 km, ideal for studying local structures of the flow bursts. The five-spacecraft THEMIS mission , separated by larger distances , succeeded to monitor the large-scale evolution of the fast flows from the mid-tail to the inner magnetosphere. Multi-point observations of BBFS have established the importance of measuring local gradients of the fields and the plasma to understand the BBF structures such as the spatial scales and 3D structure of localized Earthward convecting flux tubes. Among others the magnetic field disturbance forming at the front of BBF, called dipolarization front (DF), has been intensively studied. From the propagation properties of DF relative to the flows and by comparing with ionospheric data, the evolution of the fast flows in terms of magnetosphere-ionospheric coupling through field-aligned currents are established. An important aspect of BBF is the interaction of the Earthward plasma jets and the Earth's dipole field. Multi-point observations combined with ground-based observations enabled to resolve how the BBFs are braked , diverted, or bounced back at the high-pressure gradient region. The multi-point capabilities in space enabled to study the BBF structure as well as large-scale evolution of BBFs. These processes are also universal processes in space plasmas and are, for example, associated with the reconnection process during the solar flares or leading to auroral phenomena at different planets.

Integrated Multi-Point Space Plasma Measurements With Four Ionospheric Satellites

NASA Astrophysics Data System (ADS)

Siefring, C. L.; Bernhardt, P. A.; Selcher, C.; Wilkens, M. R.; McHarg, M. G.; Krause, L.; Chun, F.; Enloe, L.; Panholzer, R.; Sakoda, D.; Phelps, R.; D Roussel-Dupre, D.; Colestock, P.; Close, S.

2006-12-01

The STP-1 launch scheduled for late 2006 will place four satellites with ionospheric plasma diagnostics into the same nearly circular orbit with an altitude of 560 km and inclination of 35.4°. The satellites will allow for unique multipoint measurements of ionospheric scintillations and their causes. Both the radio and in-situ diagnostics will provide coverage of low- and mid-latitudes. The four satellites, STPSat1, NPSat1, FalconSat3, and CFE will follow the same ground-track but because of drag and mass differences their relative velocities will be different and vary during the lifetime of the satellites. The four satellites will start close together; separate over a few months and coming back together with near conjunctions at six and eight months. Two satellite conjunctions between NPSat1 and STPSat1 will occur most often, approximately one month apart at the end of the mission. STPSat1 is equipped with CITRIS (sCintillation and TEC Receiver In Space) which will measure scintillations in the VHF, UHF and L-band along with measuring Total Electron Content (TEC) along the propagation path. NPSat1 will carry a three-frequency CERTO (Coherent Electromagnetic Radio TOmography) Beacon which broadcasts phase-coherent signals at 150.012 MHz, 400.032 MHz, and 1066.752 MHz. CITRIS will be able to measure TEC and Scintillations along the orbital path (propagation path from NPSat1 to STPSat1) as well as between the CITRIS and the ground. NPSat1 carries electron and ion saturation Langmuir Probes, while FalconSat3 carries the FLAPS (FLAt Plasma Spectrometer) and PLANE (Plasma Local Anomalous Noise Environment). The in-situ diagnostic complement the CITRIS/CERTO radio techniques in many ways. The CIBOLA Flight Experiment (CFE) contains a wide band receiver covering 100 to 500 MHz. The CFE data can be processed to show distortion of wide-band modulations by ionospheric irregularities. CFE and CITRIS can record ground transmissions from the French DORIS beacons which radiate at 401.25 and 2036.25 MHz. The multi-point techniques provide redundant measurements of radio scintillations and other ionospheric distortions. The causative density irregularities will be imaged using computerized ionospheric tomographic and inverse-diffraction algorithms. The STP-1 sensors in low-earth-orbit will relate electron and ion density fluctuations and radio scintillation effects over a wide range of frequencies. This research supported at NRL by ONR.

Combustion Dynamics and Control for Ultra Low Emissions in Aircraft Gas-Turbine Engines

NASA Technical Reports Server (NTRS)

DeLaat, John C.

2011-01-01

Future aircraft engines must provide ultra-low emissions and high efficiency at low cost while maintaining the reliability and operability of present day engines. The demands for increased performance and decreased emissions have resulted in advanced combustor designs that are critically dependent on efficient fuel/air mixing and lean operation. However, all combustors, but most notably lean-burning low-emissions combustors, are susceptible to combustion instabilities. These instabilities are typically caused by the interaction of the fluctuating heat release of the combustion process with naturally occurring acoustic resonances. These interactions can produce large pressure oscillations within the combustor and can reduce component life and potentially lead to premature mechanical failures. Active Combustion Control which consists of feedback-based control of the fuel-air mixing process can provide an approach to achieving acceptable combustor dynamic behavior while minimizing emissions, and thus can provide flexibility during the combustor design process. The NASA Glenn Active Combustion Control Technology activity aims to demonstrate active control in a realistic environment relevant to aircraft engines by providing experiments tied to aircraft gas turbine combustors. The intent is to allow the technology maturity of active combustion control to advance to eventual demonstration in an engine environment. Work at NASA Glenn has shown that active combustion control, utilizing advanced algorithms working through high frequency fuel actuation, can effectively suppress instabilities in a combustor which emulates the instabilities found in an aircraft gas turbine engine. Current efforts are aimed at extending these active control technologies to advanced ultra-low-emissions combustors such as those employing multi-point lean direct injection.

NASA's THEMIS Mission: Multipoint Observations of Substorms, the Foreshock, and the Magnetopause

NASA Technical Reports Server (NTRS)

Sibeck, D. G.; Angelopoulos, V.; Kuznetsova, M.; Glabmeier, K.-H.; McFadden. J. P.

2008-01-01

From launch on February 17 through the repositioning to final orbits that began in September 2007, the five-spacecraft of the THEMIS mission operated nominally in nearly identical 14.6 RE apogee near-equatorial orbits. On March 23, while aligned from east to west in the duskside magnetotail, the spacecraft observed two substorm sequences in fast survey mode. Timing the motion of these signatures served as an early proof of concept for the main phase of the mission: particle injection and dipolarization signatures propagated duskward from one probe to another, as did auroral intensifications seen by the dedicated array of ground-based observatories. During the summer of 2007, the spacecraft were on the dayside, where the three inner spacecraft (C, D, E) were separated by 100-500 km and the two outer probes (B, -4) by 5,000 - 10,000 km. Here the THEMIS probes repeatedly encountered the magnetopause and bow shock, dissecting flux transfer events (FTEs), determining the instantaneous width of the low-latitude boundary layer, and simultaneously observing hot flow anomalies upstream and downstream from the bow shock at the moment of their inception. From January to March 2008, the spacecraft were in the Earths magnetotail with apogees of 31.0, 19.5, 11.8 (2) and 10.0 RE corresponding to periods of 4, 2, and 1 days. Radial alignments once each four days offered an opportunity to pinpoint when and where substorms begin. This talk reviews THEMIS discoveries to date, with an emphasis on model-data comparisons of FTE characteristics

Systematic Search for Gene-Gene Interaction Effect on Prostate Cancer Risk

DTIC Science & Technology

2012-07-01

U b . ABSTRACT U c. THIS PAGE U UU 26 19b. TELEPHONE NUMBER (include area code) Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std...Marchini, J., Howie, B ., Myers, S., McVean, G. and Donnelly, P. (2007) A new multipoint method for genome-wide association studies by imputation of...Benediktsdottir, K.R., Cazier, J.B., Sainz, J., Jakobsdottir, M., Kostic, J., Magnusdottir, D.N., Ghosh, S., Agnarsson, K., Birgisdottir, B ., Le Roux, L

Deformations of thick two-material cylinder under axially varying radial pressure

NASA Technical Reports Server (NTRS)

Patel, Y. A.

1976-01-01

Stresses and deformations in thick, short, composite cylinder subjected to axially varying radial pressure are studied. Effect of slippage at the interface is examined. In the NASTRAN finite element model, multipoint constraint feature is utilized. Results are compared with theoretical analysis and SAP-IV computer code. Results from NASTRAN computer code are in good agreement with the analytical solutions. Results suggest a considerable influence of interfacial slippage on the axial bending stresses in the cylinder.

KSC-06pd0262

NASA Image and Video Library

2005-12-27

VANDENBERG AIR FORCE BASE, CALIF. - Inside Orbital Sciences Building 1555 at Vandenberg Air Force Base in California, a worker underneath the tail of the Pegasus XL rocket completes installation of the fin. The Pegasus will launch the Space Technology 5 spacecraft later this month. ST5 contains three micro-satellites that will be positioned in a "string of pearls" constellation to perform simultaneous multi-point measurements of the Earth's magnetic field using highly sensitive magnetometers. The scheduled launch date is Feb. 28.

KSC-06pd0261

NASA Image and Video Library

2005-12-27

VANDENBERG AIR FORCE BASE, CALIF. - Inside Orbital Sciences Building 1555 at Vandenberg Air Force Base in California, a worker installs one of the fins on the aft skirt of the Pegasus XL rocket that will launch the Space Technology 5 spacecraft later this month. ST5 contains three micro-satellites that will be positioned in a "string of pearls" constellation to perform simultaneous multi-point measurements of the Earth's magnetic field using highly sensitive magnetometers. The scheduled launch date is Feb. 28.

KSC-06pd0258

NASA Image and Video Library

2005-12-27

VANDENBERG AIR FORCE BASE, CALIF. - Inside Orbital Sciences Building 1555 at Vandenberg Air Force Base in California, workers move the aft skirt toward the Pegasus XL launch vehicle for mating. The Pegasus will launch the Space Technology 5 spacecraft later this month. ST5 contains three micro-satellites that will be positioned in a "string of pearls" constellation to perform simultaneous multi-point measurements of the Earth's magnetic field using highly sensitive magnetometers. The scheduled launch date is Feb. 28.

Suitability Evaluation of Multipoint Simultaneous CO2 Sampling Wireless Sensors for Livestock Buildings

PubMed Central

Calvet, Salvador; Campelo, José Carlos; Estellés, Fernando; Perles, Angel; Mercado, Ricardo; Serrano, Juan José

2014-01-01

The environment in livestock buildings must be controlled to ensure the health and welfare of both workers and animals, as well as to restrict the emission of pollutants to the atmosphere. Among the pollutants generated inside these premises, carbon dioxide (CO2) is of great interest in terms of animal welfare and ventilation control. The use of inexpensive sensors means that complete systems can be designed with a number of sensors located around the building. This paper describes a study of the suitability of multipoint simultaneous CO2 sensors operating in a wireless sensor network, which was found to operate satisfactorily under laboratory conditions and was found to be the best alternative for these applications. The sensors showed a highly linear response to CO2 concentrations, ranging from 500 to 5000 ppm. However, individual sensor response was found to differ, which made it necessary to calibrate each one separately. Sensor precision ranged between 80 and 110 ppm CO2, and sensor response to register a 95% change in concentration was estimated at around 5 min. These features mean this type of sensor network can be used to monitor animal welfare and also for environmental control in poorly ventilated livestock premises. According to the tests conducted in this study, a temporal drift may occur and therefore a regular calibration of sensors would be needed. PMID:24932867

A Novel RFID-Based Sensing Method for Low-Cost Bolt Loosening Monitoring.

PubMed

Wu, Jian; Cui, Xingmei; Xu, Yunpeng

2016-01-28

In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide structures. This paper proposes a system to monitor bolt status in harsh environments established based on the RFID technique. A proof-of-concept model was demonstrated consisting of a bolt gearing system, passive UHF RFID tags, a reader, and monitoring software. A tinfoil metal film is fixed on the retaining plate and an RFID tag bonded to a large gear, with the bolt to be detected fixed in the center of a smaller gear. The radio-frequency signal cannot be received by the reader if the tag is completely obscured by the tinfoil, and if the bolt is loose, the tag's antenna is exposed when the gear revolves. A radio-frequency signal that carries corresponding bolt's information is transmitted by the RFID tag to the RFID reader due to coil coupling, identifying loose bolt location and reporting them in the software. Confirmatory test results revealed that the system indeed successfully detects bolt loosening and comparative test results (based on a reed switch multipoint bolt loosening monitor system) provided valuable information regarding the strengths and weaknesses of the proposed system.

Results of a SNP genome screen in a large Costa Rican pedigree segregating for severe bipolar disorder.

PubMed

Service, Susan; Molina, Julio; Deyoung, Joseph; Jawaheer, Damini; Aldana, Ileana; Vu, Thuy; Araya, Carmen; Araya, Xinia; Bejarano, Julio; Fournier, Eduardo; Ramirez, Magui; Mathews, Carol A; Davanzo, Pablo; Macaya, Gabriel; Sandkuijl, Lodewijk; Sabatti, Chiara; Reus, Victor; Freimer, Nelson

2006-06-05

We have ascertained in the Central Valley of Costa Rica a new kindred (CR201) segregating for severe bipolar disorder (BP-I). The family was identified by tracing genealogical connections among eight persons initially independently ascertained for a genome wide association study of BP-I. For the genome screen in CR201, we trimmed the family down to 168 persons (82 of whom are genotyped), containing 25 individuals with a best-estimate diagnosis of BP-I. A total of 4,690 SNP markers were genotyped. Analysis of the data was hampered by the size and complexity of the pedigree, which prohibited using exact multipoint methods on the entire kindred. Two-point parametric linkage analysis, using a conservative model of transmission, produced a maximum LOD score of 2.78 on chromosome 6, and a total of 39 loci with LOD scores >1.0. Multipoint parametric and non-parametric linkage analysis was performed separately on four sections of CR201, and interesting (nominal P-value from either analysis <0.01), although not statistically significant, regions were highlighted on chromosomes 1, 2, 3, 12, 16, 19, and 22, in at least one section of the pedigree, or when considering all sections together. The difficulties of analyzing genome wide SNP data for complex disorders in large, potentially informative, kindreds are discussed.

A Novel RFID-Based Sensing Method for Low-Cost Bolt Loosening Monitoring

PubMed Central

Wu, Jian; Cui, Xingmei; Xu, Yunpeng

2016-01-01

In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide structures. This paper proposes a system to monitor bolt status in harsh environments established based on the RFID technique. A proof-of-concept model was demonstrated consisting of a bolt gearing system, passive UHF RFID tags, a reader, and monitoring software. A tinfoil metal film is fixed on the retaining plate and an RFID tag bonded to a large gear, with the bolt to be detected fixed in the center of a smaller gear. The radio-frequency signal cannot be received by the reader if the tag is completely obscured by the tinfoil, and if the bolt is loose, the tag’s antenna is exposed when the gear revolves. A radio-frequency signal that carries corresponding bolt’s information is transmitted by the RFID tag to the RFID reader due to coil coupling, identifying loose bolt location and reporting them in the software. Confirmatory test results revealed that the system indeed successfully detects bolt loosening and comparative test results (based on a reed switch multipoint bolt loosening monitor system) provided valuable information regarding the strengths and weaknesses of the proposed system. PMID:26828498

Lod scores for gene mapping in the presence of marker map uncertainty.

PubMed

Stringham, H M; Boehnke, M

2001-07-01

Multipoint lod scores are typically calculated for a grid of locus positions, moving the putative disease locus across a fixed map of genetic markers. Changing the order of a set of markers and/or the distances between the markers can make a substantial difference in the resulting lod score curve and the location and height of its maximum. The typical approach of using the best maximum likelihood marker map is not easily justified if other marker orders are nearly as likely and give substantially different lod score curves. To deal with this problem, we propose three weighted multipoint lod score statistics that make use of information from all plausible marker orders. In each of these statistics, the information conditional on a particular marker order is included in a weighted sum, with weight equal to the posterior probability of that order. We evaluate the type 1 error rate and power of these three statistics on the basis of results from simulated data, and compare these results to those obtained using the best maximum likelihood map and the map with the true marker order. We find that the lod score based on a weighted sum of maximum likelihoods improves on using only the best maximum likelihood map, having a type 1 error rate and power closest to that of using the true marker order in the simulation scenarios we considered. Copyright 2001 Wiley-Liss, Inc.

Rogue waves in terms of multi-point statistics and nonequilibrium thermodynamics

NASA Astrophysics Data System (ADS)

Hadjihosseini, Ali; Lind, Pedro; Mori, Nobuhito; Hoffmann, Norbert P.; Peinke, Joachim

2017-04-01

Ocean waves, which lead to rogue waves, are investigated on the background of complex systems. In contrast to deterministic approaches based on the nonlinear Schroedinger equation or focusing effects, we analyze this system in terms of a noisy stochastic system. In particular we present a statistical method that maps the complexity of multi-point data into the statistics of hierarchically ordered height increments for different time scales. We show that the stochastic cascade process with Markov properties is governed by a Fokker-Planck equation. Conditional probabilities as well as the Fokker-Planck equation itself can be estimated directly from the available observational data. This stochastic description enables us to show several new aspects of wave states. Surrogate data sets can in turn be generated allowing to work out different statistical features of the complex sea state in general and extreme rogue wave events in particular. The results also open up new perspectives for forecasting the occurrence probability of extreme rogue wave events, and even for forecasting the occurrence of individual rogue waves based on precursory dynamics. As a new outlook the ocean wave states will be considered in terms of nonequilibrium thermodynamics, for which the entropy production of different wave heights will be considered. We show evidence that rogue waves are characterized by negative entropy production. The statistics of the entropy production can be used to distinguish different wave states.

Numerical Study of Pressure Fluctuations due to High-Speed Turbulent Boundary Layers

NASA Technical Reports Server (NTRS)

Duan, Lian; Choudhari, Meelan M.; Wu, Minwei

2012-01-01

Direct numerical simulations (DNS) are used to examine the pressure fluctuations generated by fully developed turbulence in supersonic turbulent boundary layers with an emphasis on both pressure fluctuations at the wall and the acoustic fluctuations radiated into the freestream. The wall and freestream pressure fields are first analyzed for a zero pressure gradient boundary layer with Mach 2.5 and Reynolds number based on momentum thickness of approximately 2835. The single and multi-point statistics reported include the wall pressure fluctuation intensities, frequency spectra, space-time correlations, and convection velocities. Single and multi-point statistics of surface pressure fluctuations show good agreement with measured data and previously published simulations of turbulent boundary layers under similar flow conditions. Spectral analysis shows that the acoustic fluctuations outside the boundary layer region have much lower energy content within the high-frequency region. The space-time correlations reflect the convective nature of the pressure field both at the wall and in the freestream, which is characterized by the downstream propagation of pressure-carrying eddies. Relative to those at the wall, the pressure-carrying eddies associated with the freestream signal are larger and convect at a significantly lower speed. The preliminary DNS results of a Mach 6 boundary layer show that the pressure rms in the freestream region is significantly higher than that of the lower Mach number case.

The application of a shift theorem analysis technique to multipoint measurements

NASA Astrophysics Data System (ADS)

Dieckmann, M. E.; Chapman, S. C.

1999-03-01

A Fourier domain technique has been proposed previously which, in principle, quantifies the extent to which multipoint in-situ measurements can identify whether or not an observed structure is time stationary in its rest frame. Once a structure, sampled for example by four spacecraft, is shown to be quasi-stationary in its rest frame, the structure's velocity vector can be determined with respect to the sampling spacecraft. We investigate the properties of this technique, which we will refer to as a stationarity test, by applying it to two point measurements of a simulated boundary layer. The boundary layer was evolved using a PIC (particle in cell) electromagnetic code. Initial and boundary conditions were chosen such, that two cases could be considered, i.e. a spacecraft pair moving through (1) a time stationary boundary structure and (2) a boundary structure which is evolving (expanding) in time. The code also introduces noise in the simulated data time series which is uncorrelated between the two spacecraft. We demonstrate that, provided that the time series is Hanning windowed, the test is effective in determining the relative velocity between the boundary layer and spacecraft and in determining the range of frequencies over which the data can be treated as time stationary or time evolving. This work presents a first step towards understanding the effectiveness of this technique, as required in order for it to be applied to multispacecraft data.

Multipoint Geospace Science in 3D: The Paired Ionosphere-Thermosphere Orbiters(PITO) Mission

NASA Technical Reports Server (NTRS)

Clemmons, J.; Walterscheid, R.; Nigg, D.; Judnick, D.; Lang, J.; Spann, J.

2010-01-01

The science enabled by the Paired Ionosphere-Thermosphere Orbiters (PITO) mission is described and discussed. PITO has been designed to provide the concurrent, three-dimensional, multipoint measurements needed to advance geospace science while staying within a stringent resource envelope. The mission utilizes a pair of orbiting vehicles in eccentric, high-inclination, coplanar orbits. The orbits have arguments of perigee that differ by 180 degrees and are phased such that one vehicle is at perigee (200 km) while the second is at apogee (2000 km). Half an orbit later, the vehicles switch positions. Three complementary types of measurements exploit this scenario: local, in-situ measurements on both satellites, two-dimensional imaging from the higher satellite, and vertical sounders. The main idea is that two-dimensional context information for the low-altitude measurements is obtained by the high altitude imagers, while information on the third dimension is provided by vertical profiling. Such an observation system is capable of providing elements of global coverage, regional coverage, and concurrent coverage in three dimensions. Science goals are presented, as are the results of a detailed implementation plan, including several trade studies on key elements of the mission. The conclusion is that the mission would enable significant new understanding of the ionosphere-thermosphere system within a resource envelope that is consistent with that of NASA's Medium Explorer (MIDEX) line of science missions.

Live-cell imaging of G-actin dynamics using sequential FDAP

PubMed Central

Kiuchi, Tai; Nagai, Tomoaki; Ohashi, Kazumasa; Watanabe, Naoki; Mizuno, Kensaku

2011-01-01

Various microscopic techniques have been developed to understand the mechanisms that spatiotemporally control actin filament dynamics in live cells. Kinetic data on the processes of actin assembly and disassembly on F-actin have been accumulated. However, the kinetics of cytoplasmic G-actin, a key determinant for actin polymerization, has remained unclear because of a lack of appropriate methods to measure the G-actin concentration quantitatively. We have developed two new microscopic techniques based on the fluorescence decay after photoactivation (FDAP) time-lapse imaging of photoswitchable Dronpa-labeled actin. These techniques, sequential FDAP (s-FDAP) and multipoint FDAP, were used to measure the time-dependent changes in and spatial distribution of the G-actin concentration in live cells. Use of s-FDAP provided data on changes in the G-actin concentration with high temporal resolution; these data were useful for the model analysis of actin assembly processes in live cells. The s-FDAP analysis also provided evidence that the cytoplasmic G-actin concentration substantially decreases after cell stimulation and that the extent of stimulus-induced actin assembly and cell size extension are linearly correlated with the G-actin concentration before cell stimulation. The advantages of using s-FDAP and multipoint FDAP to measure spatiotemporal G-actin dynamics and the roles of G-actin concentration and ADF/cofilin in stimulus-induced actin assembly and lamellipodium extension in live cells are discussed. PMID:22754616

A hybrid integrated services digital network-internet protocol solution for resident education.

PubMed

Erickson, Delnora; Greer, Lester; Belard, Arnaud; Tinnel, Brent; O'Connell, John

2010-05-01

The purpose of this study was to explore the effectiveness of incorporating Web-based application sharing of virtual medical simulation software within a multipoint video teleconference (VTC) as a training tool in graduate medical education. National Capital Consortium Radiation Oncology Residency Program resident and attending physicians participated in dosimetry teaching sessions held via VTC using Acrobat Connect application sharing. Residents at remote locations could take turns designing radiation treatments using standard three-dimensional planning software, whereas instructors gave immediate feedback and demonstrated proper techniques. Immediately after each dosimetry lesson, residents were asked to complete a survey that evaluated the effectiveness of the session. At the end of a 3-month trial of using Adobe Connect, residents completed a final survey that compared this teaching technology to the prior VTC-alone method. The mean difference from equality across all quality measures from the weekly survey was 0.8, where 0 indicated neither enhanced nor detracted from the learning experience and 1 indicated a minor enhancement in the learning experience. The mean difference from equality across all measures from the final survey comparing use of application sharing with VTC to VTC alone was 1.5, where 1 indicated slightly better and 2 indicated a somewhat better experience. The teaching efficacy of multipoint VTC is perceived by medical residents to be more effective when complemented by application-sharing software such as Adobe Acrobat Connect.

Development of a novel multi-point plastic scintillation detector with a single optical transmission line for radiation dose measurement*

PubMed Central

Therriault-Proulx, François; Archambault, Louis; Beaulieu, Luc; Beddar, Sam

2013-01-01

Purpose The goal of this study was to develop a novel multi-point plastic scintillation detector (mPSD) capable of measuring the dose accurately at multiple positions simultaneously using a single optical transmission line. Methods A 2-point mPSD used a band-pass approach that included splitters, color filters, and an EMCCD camera. The 3-point mPSD was based on a new full-spectrum approach, in which a spectrograph was coupled to a CCD camera. Irradiations of the mPSDs and of an ion chamber were performed with a 6-MV photon beam at various depths and lateral positions in a water tank. Results For the 2-point mPSD, the average relative differences between mPSD and ion chamber measurements for the depth-dose were 2.4±1.6% and 1.3±0.8% for BCF-60 and BCF-12, respectively. For the 3-point mPSD, the average relative differences over all conditions were 2.3±1.1%, 1.6±0.4%, and 0.32±0.19% for BCF-60, BCF-12, and BCF-10, respectively. Conclusions This study demonstrates the practical feasibility of mPSDs. This type of detector could be very useful for pre-treatment quality assurance applications as well as an accurate tool for real-time in vivo dosimetry. PMID:23060069

Modelisation de l'architecture des forets pour ameliorer la teledetection des attributs forestiers

NASA Astrophysics Data System (ADS)

Cote, Jean-Francois

The quality of indirect measurements of canopy structure, from in situ and satellite remote sensing, is based on knowledge of vegetation canopy architecture. Technological advances in ground-based, airborne or satellite remote sensing can now significantly improve the effectiveness of measurement programs on forest resources. The structure of vegetation canopy describes the position, orientation, size and shape of elements of the canopy. The complexity of the canopy in forest environments greatly limits our ability to characterize forest structural attributes. Architectural models have been developed to help the interpretation of canopy structural measurements by remote sensing. Recently, the terrestrial LiDAR systems, or TLiDAR (Terrestrial Light Detection and Ranging), are used to gather information on the structure of individual trees or forest stands. The TLiDAR allows the extraction of 3D structural information under the canopy at the centimetre scale. The methodology proposed in my Ph.D. thesis is a strategy to overcome the weakness in the structural sampling of vegetation cover. The main objective of the Ph.D. is to develop an architectural model of vegetation canopy, called L-Architect (LiDAR data to vegetation Architecture), and to focus on the ability to document forest sites and to get information on canopy structure from remote sensing tools. Specifically, L-Architect reconstructs the architecture of individual conifer trees from TLiDAR data. Quantitative evaluation of L-Architect consisted to investigate (i) the structural consistency of the reconstructed trees and (ii) the radiative coherence by the inclusion of reconstructed trees in a 3D radiative transfer model. Then, a methodology was developed to quasi-automatically reconstruct the structure of individual trees from an optimization algorithm using TLiDAR data and allometric relationships. L-Architect thus provides an explicit link between the range measurements of TLiDAR and structural attributes of individual trees. L-Architect has finally been applied to model the architecture of forest canopy for better characterization of vertical and horizontal structure with airborne LiDAR data. This project provides a mean to answer requests of detailed canopy architectural data, difficult to obtain, to reproduce a variety of forest covers. Because of the importance of architectural models, L-Architect provides a significant contribution for improving the capacity of parameters' inversion in vegetation cover for optical and lidar remote sensing. Mots-cles: modelisation architecturale, lidar terrestre, couvert forestier, parametres structuraux, teledetection.

Ground observations and remote sensing data for integrated modelisation of water budget in the Merguellil catchment, Tunisia

NASA Astrophysics Data System (ADS)

Mougenot, Bernard

2016-04-01

The Mediterranean region is affected by water scarcity. Some countries as Tunisia reached the limit of 550 m3/year/capita due overexploitation of low water resources for irrigation, domestic uses and industry. A lot of programs aim to evaluate strategies to improve water consumption at regional level. In central Tunisia, on the Merguellil catchment, we develop integrated water resources modelisations based on social investigations, ground observations and remote sensing data. The main objective is to close the water budget at regional level and to estimate irrigation and water pumping to test scenarios with endusers. Our works benefit from French, bilateral and European projects (ANR, MISTRALS/SICMed, FP6, FP7…), GMES/GEOLAND-ESA) and also network projects as JECAM and AERONET, where the Merguellil site is a reference. This site has specific characteristics associating irrigated and rainfed crops mixing cereals, market gardening and orchards and will be proposed as a new environmental observing system connected to the OMERE, TENSIFT and OSR systems respectively in Tunisia, Morocco and France. We show here an original and large set of ground and remote sensing data mainly acquired from 2008 to present to be used for calibration/validation of water budget processes and integrated models for present and scenarios: - Ground data: meteorological stations, water budget at local scale: fluxes tower, soil fluxes, soil and surface temperature, soil moisture, drainage, flow, water level in lakes, aquifer, vegetation parameters on selected fieds/month (LAI, height, biomass, yield), land cover: 3 times/year, bare soil roughness, irrigation and pumping estimations, soil texture. - Remote sensing data: remote sensing products from multi-platform (MODIS, SPOT, LANDSAT, ASTER, PLEIADES, ASAR, COSMO-SkyMed, TerraSAR X…), multi-wavelength (solar, micro-wave and thermal) and multi-resolution (0.5 meters to 1 km). Ground observations are used (1) to calibrate soil-vegetation-atmosphere models at field scale on different compartment and irrigated and rainfed land during a limited time (seasons or set of dry and wet years), (2) to calibrate and validate particularly evapotranspiration derived from multi-wavelength satellite data at watershed level in relationships with the aquifer conditions: pumping and recharge rate. We will point out some examples.

Prediction du profil de durete de l'acier AISI 4340 traite thermiquement au laser

NASA Astrophysics Data System (ADS)

Maamri, Ilyes

Les traitements thermiques de surfaces sont des procedes qui visent a conferer au coeur et a la surface des pieces mecaniques des proprietes differentes. Ils permettent d'ameliorer la resistance a l'usure et a la fatigue en durcissant les zones critiques superficielles par des apports thermiques courts et localises. Parmi les procedes qui se distinguent par leur capacite en terme de puissance surfacique, le traitement thermique de surface au laser offre des cycles thermiques rapides, localises et precis tout en limitant les risques de deformations indesirables. Les proprietes mecaniques de la zone durcie obtenue par ce procede dependent des proprietes physicochimiques du materiau a traiter et de plusieurs parametres du procede. Pour etre en mesure d'exploiter adequatement les ressources qu'offre ce procede, il est necessaire de developper des strategies permettant de controler et regler les parametres de maniere a produire avec precision les caracteristiques desirees pour la surface durcie sans recourir au classique long et couteux processus essai-erreur. L'objectif du projet consiste donc a developper des modeles pour predire le profil de durete dans le cas de traitement thermique de pieces en acier AISI 4340. Pour comprendre le comportement du procede et evaluer les effets des differents parametres sur la qualite du traitement, une etude de sensibilite a ete menee en se basant sur une planification experimentale structuree combinee a des techniques d'analyse statistiques eprouvees. Les resultats de cette etude ont permis l'identification des variables les plus pertinentes a exploiter pour la modelisation. Suite a cette analyse et dans le but d'elaborer un premier modele, deux techniques de modelisation ont ete considerees, soient la regression multiple et les reseaux de neurones. Les deux techniques ont conduit a des modeles de qualite acceptable avec une precision d'environ 90%. Pour ameliorer les performances des modeles a base de reseaux de neurones, deux nouvelles approches basees sur la caracterisation geometrique du profil de durete ont ete considerees. Contrairement aux premiers modeles predisant le profil de durete en fonction des parametres du procede, les nouveaux modeles combinent les memes parametres avec les attributs geometriques du profil de durete pour refleter la qualite du traitement. Les modeles obtenus montrent que cette strategie conduit a des resultats tres prometteurs.

A Fully Integrated Micro-Magnometer/Microspacecraft for Multipoint Measurements: The Free-Flyer Magnometer

NASA Technical Reports Server (NTRS)

Goldstein, R.; Miller, L. N.; Fossum, E.; Pain, B.; Randolph, J. E.; Turner, P. R.; Cutting, E.

1995-01-01

In the decades since the advent of in situ plasma measurements on board spacecraft, the instrumentation has grown bigger, heavier, and more complex as our understanding of space plasmas improves and our appetite for more information increases...There has thus been a recent interest in the miniaturization of both spacecraft and the instrument payload... This paper describes the results and status of an ongoing design study to understand the problems and trade space of fully integrating an instrument into a micro-spacecraft.

Nance-Horan syndrome: linkage analysis in a family from The Netherlands.

PubMed

Bergen, A A; ten Brink, J; Schuurman, E J; Bleeker-Wagemakers, E M

1994-05-01

Linkage analysis was carried out in a Dutch family with Nance-Horan (NH) syndrome. Close linkage without recombination between NH and the Xp loci DXS207, DXS43, and DXS365 (zmax = 3.23) was observed. Multipoint linkage analysis and the analysis of recombinations in multiple informative meioses suggest the genetic order Xcen-DMD (exon 49)-DXS451-(NH, DXS207, DXS365, DXS43)-(STS, DXF30)-Xpter. These data refine the localization of the NH locus on the distal Xp.

Measurements of Vorticity Vectors in Couette Flow with the Vorticity Optical Probe

DTIC Science & Technology

1991-05-01

Web 1981). The three components of the vorticity vector are measured, any two of them quite accurately. Multipoint measurement arrangements have been...the distribution of trajectory lengths is given by POrN ) rN O<rN<R. fwio-R R -rN where R is the angular measure of the detector radius. (The random...orticitv were performed deep within the viscous sublaver v 2.3). .At y < 10. the fluctuating vortici, ,tatistics show good agreement with the simulatins of

KSC-06pd0260

NASA Image and Video Library

2005-12-27

VANDENBERG AIR FORCE BASE, CALIF. - Inside Orbital Sciences Building 1555 at Vandenberg Air Force Base in California, workers get ready to install one of the fins on the aft skirt of the Pegasus XL rocket that will launch the Space Technology 5 spacecraft later this month. ST5 contains three micro-satellites that will be positioned in a "string of pearls" constellation to perform simultaneous multi-point measurements of the Earth's magnetic field using highly sensitive magnetometers. The scheduled launch date is Feb. 28.

NRL EIGHTH CARD Program Interim Progress Report, 1 March 1969 to 30 September 1969

DTIC Science & Technology

1969-12-31

methods to measure the water vapor content of the atmosphere have been inves- tigated. One is based on the psychrometer method of measuring wet and dry bulb...over and under configuration. A shipboard psychrometer consisting of the sensors and blower and an 18.5-foot-high intake stack has been mounted on a...small boat. The intake stack may be partially dismounted to pro- vide a 9-foot intake level. The readout for the psychrometer is a multipoint Leeds and

Material Behavior At The Extreme Cutting Edge In Bandsawing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarwar, Mohammed; Haider, Julfikar; Persson, Martin

2011-01-17

In recent years, bandsawing has been widely accepted as a favourite option for metal cutting off operations where the accuracy of cut, good surface finish, low kerf loss, long tool life and high material removal rate are required. Material removal by multipoint cutting tools such as bandsaw is a complex mechanism owing to the geometry of the bandsaw tooth (e.g., limited gullet size, tooth setting etc.) and the layer of material removed or undeformed chip thickness or depth of cut (5 {mu}m-50 {mu}m) being smaller than or equal to the cutting edge radius (5 {mu}m-15 {mu}m). This situation can leadmore » to inefficient material removal in bandsawing. Most of the research work are concentrated on the mechanics of material removal by single point cutting tool such as lathe tool. However, such efforts are very limited in multipoint cutting tools such as in bandsaw. This paper presents the fundamental understanding of the material behaviour at the extreme cutting edge of bandsaw tooth, which would help in designing and manufacturing of blades with higher cutting performance and life. ''High Speed Photography'' has been carried out to analyse the material removal process at the extreme cutting edge of bandsaw tooth. Geometric model of chip formation mechanisms based on the evidences found during ''High Speed Photography'' and ''Quick Stop'' process is presented. Wear modes and mechanism in bimetal and carbide tipped bandsaw teeth are also presented.« less

Numerical study of multi-point forming of thick sheet using remeshing procedure

NASA Astrophysics Data System (ADS)

Cherouat, A.; Ma, X.; Borouchaki, H.; Zhang, Q.

2018-05-01

Multi-point forming MPF is an innovative technology of manufacturing complex thick sheet metal products without the need for solid tools. The central component of this system is a pair of the desired discrete matrices of punches, and die surface constructed by changing the positions of the tools though CAD and a control system. Because reconfigurable discrete tools are used, part-manufacturing costs are reduced and manufacturing time is shorten substantially. Firstly, in this work we develop constitutive equations which couples isotropic ductile damage into various flow stress based on the Continuum Damage Mechanic theory. The modified Johnson-Cook flow model fully coupled with an isotropic ductile damage is established using the quasi-unilateral damage evolution for considering both the open and the close of micro-cracks. During the forming processes severe mesh distortion of elements occur after a few incremental forming steps. Secondly, we introduce 3D adaptive remeshing procedure based on linear tetrahedral element and geometrical/physical errors estimation to optimize the element quality, to refine the mesh size in the whole model and to adapt the deformed mesh to the tools geometry. Simulation of the MPF process (see Fig. 1) and the unloading spring-back are carried out using adaptive remeshing scheme using the commercial finite element package ABAQUS and OPTIFORM mesher. Subsequently, influencing factors of MPF spring-back are researched to investigate the MPF spring-back tendency with the proposed remeshing procedure.

Design of a mutual authentication based on NTRUsign with a perturbation and inherent multipoint control protocol frames in an Ethernet-based passive optical network

NASA Astrophysics Data System (ADS)

Yin, Aihan; Ding, Yisheng

2014-11-01

Identity-related security issues inherently present in passive optical networks (PON) still exist in the current (1G) and next-generation (10G) Ethernet-based passive optical network (EPON) systems. We propose a mutual authentication scheme that integrates an NTRUsign digital signature algorithm with inherent multipoint control protocol (MPCP) frames over an EPON system between the optical line terminal (OLT) and optical network unit (ONU). Here, a primitive NTRUsign algorithm is significantly modified through the use of a new perturbation so that it can be effectively used for simultaneously completing signature and authentication functions on the OLT and the ONU sides. Also, in order to transmit their individual sensitive messages, which include public key, signature, and random value and so forth, to each other, we redefine three unique frames according to MPCP format frame. These generated messages can be added into the frames and delivered to each other, allowing the OLT and the ONU to go ahead with a mutual identity authentication process to verify their legal identities. Our simulation results show that this proposed scheme performs very well in resisting security attacks and has low influence on the registration efficiency to to-be-registered ONUs. A performance comparison with traditional authentication algorithms is also presented. To the best of our knowledge, no detailed design of mutual authentication in EPON can be found in the literature up to now.

Examining the candidacy of ghrelin as a gene responsible for variation in adult stature in a United Kingdom population with type 2 diabetes.

PubMed

Gueorguiev, Maria; Wiltshire, Steven; Garcia, Edwin A; Mein, Charles; Lecoeur, Cecile; Kristen, Brigitte; Allotey, Rebecca; Hattersley, Andrew T; Walker, Mark; O'rahilly, Stephen; Froguel, Philippe; Grossman, Ashley B; McCarthy, Mark I; Hitman, Graham A; Korbonits, Márta

2007-06-01

Recently, a quantitative trait locus for stature was reported on chromosome 3p26 in patients with type 2 diabetes. Given that ghrelin is a peptide involved in GH release and located on 3p26, we hypothesized that variation within its gene (GHRL) may be responsible for the quantitative trait locus on 3p26. The evidence for linkage around GHRL was refined with the genotyping of an additional four microsatellites (D3S4545, D3S1537, D3S1597, and D3S3611), giving a total of 27 markers, followed by multipoint variance components linkage analysis. Probands from the linkage families were typed for five common single nucleotide polymorphisms (SNPs) within GHRL and tested for association with adult stature using haplotype trend regression. The maximum multipoint evidence for linkage between adult stature and the 27 microsatellites yielded an LOD score of 2.58 (P = 0.0003) between D3S1297 and D3S1304. Five common (frequency of > or =5%) SNPs were typed in the probands [two promoter SNPs (rs27647 and rs26802), two exonic (rs696217 and rs4684677), and one intronic (rs35683)] capturing 80% of the total common variation in GHRL. No association was found between any SNP (or haplotypes thereof) and adult stature. Common genetic variation within GHRL is not responsible for variation in adult stature in this population.

Dynamic Loads Generation for Multi-Point Vibration Excitation Problems

NASA Technical Reports Server (NTRS)

Shen, Lawrence

2011-01-01

A random-force method has been developed to predict dynamic loads produced by rocket-engine random vibrations for new rocket-engine designs. The method develops random forces at multiple excitation points based on random vibration environments scaled from accelerometer data obtained during hot-fire tests of existing rocket engines. This random-force method applies random forces to the model and creates expected dynamic response in a manner that simulates the way the operating engine applies self-generated random vibration forces (random pressure acting on an area) with the resulting responses that we measure with accelerometers. This innovation includes the methodology (implementation sequence), the computer code, two methods to generate the random-force vibration spectra, and two methods to reduce some of the inherent conservatism in the dynamic loads. This methodology would be implemented to generate the random-force spectra at excitation nodes without requiring the use of artificial boundary conditions in a finite element model. More accurate random dynamic loads than those predicted by current industry methods can then be generated using the random force spectra. The scaling method used to develop the initial power spectral density (PSD) environments for deriving the random forces for the rocket engine case is based on the Barrett Criteria developed at Marshall Space Flight Center in 1963. This invention approach can be applied in the aerospace, automotive, and other industries to obtain reliable dynamic loads and responses from a finite element model for any structure subject to multipoint random vibration excitations.

Multiple-Octave-Spanning Vibration Sensing Based on Simultaneous Vector Demodulation of 499 Fizeau Interference Signals from Identical Ultra-Weak Fiber Bragg Gratings Over 2.5 km.

PubMed

Li, Yi; Qian, Li; Zhou, Ciming; Fan, Dian; Xu, Qiannan; Pang, Yandong; Chen, Xi; Tang, Jianguan

2018-01-12

Multi-point vibration sensing at the low frequency range of 0.5-100 Hz is of vital importance for applications such as seismic monitoring and underwater acoustic imaging. Location-resolved multi-point sensing using a single fiber and a single demodulation system can greatly reduce system deployment and maintenance costs. We propose and demonstrate the demodulation of a fiber-optic system consisting of 500 identical ultra-weak Fiber Bragg gratings (uwFBGs), capable of measuring the amplitude, frequency and phase of acoustic signals from 499 sensing fibers covering a total range of 2.5 km. For demonstration purposes, we arbitrarily chose six consecutive sensors and studied their performance in detail. Using a passive demodulation method, we interrogated the six sensors simultaneously, and achieved a high signal-to-noise ratio of 22.1 dB, excellent linearity, phase sensitivity of around 0.024 rad/Pa, and a dynamic range of about 38 dB. We demonstrated a frequency response flatness of <1.2 dB in the range of 0.5-100 Hz. Compared to the prior state-of-the-art demonstration using a similar method, we have increased the sensing range from 1 km to 2.5 km, and increased the frequency range from 0.4 octaves to 7.6 octaves, in addition to achieving sensing in the very challenging low-frequency range of 0.5-100 Hz.

Variable-Complexity Multidisciplinary Optimization on Parallel Computers

NASA Technical Reports Server (NTRS)

Grossman, Bernard; Mason, William H.; Watson, Layne T.; Haftka, Raphael T.

1998-01-01

This report covers work conducted under grant NAG1-1562 for the NASA High Performance Computing and Communications Program (HPCCP) from December 7, 1993, to December 31, 1997. The objective of the research was to develop new multidisciplinary design optimization (MDO) techniques which exploit parallel computing to reduce the computational burden of aircraft MDO. The design of the High-Speed Civil Transport (HSCT) air-craft was selected as a test case to demonstrate the utility of our MDO methods. The three major tasks of this research grant included: development of parallel multipoint approximation methods for the aerodynamic design of the HSCT, use of parallel multipoint approximation methods for structural optimization of the HSCT, mathematical and algorithmic development including support in the integration of parallel computation for items (1) and (2). These tasks have been accomplished with the development of a response surface methodology that incorporates multi-fidelity models. For the aerodynamic design we were able to optimize with up to 20 design variables using hundreds of expensive Euler analyses together with thousands of inexpensive linear theory simulations. We have thereby demonstrated the application of CFD to a large aerodynamic design problem. For the predicting structural weight we were able to combine hundreds of structural optimizations of refined finite element models with thousands of optimizations based on coarse models. Computations have been carried out on the Intel Paragon with up to 128 nodes. The parallel computation allowed us to perform combined aerodynamic-structural optimization using state of the art models of a complex aircraft configurations.

Dissection of Genomewide-Scan Data in Extended Families Reveals a Major Locus and Oligogenic Susceptibility for Age-Related Macular Degeneration

PubMed Central

Iyengar, Sudha K.; Song, Danhong; Klein, Barbara E. K.; Klein, Ronald; Schick, James H.; Humphrey, Jennifer; Millard, Christopher; Liptak, Rachel; Russo, Karlie; Jun, Gyungah; Lee, Kristine E.; Fijal, Bonnie; Elston, Robert C.

2004-01-01

To examine the genetic basis of age-related macular degeneration (ARMD), a degenerative disease of the retinal pigment epithelium and neurosensory retina, we conducted a genomewide scan in 34 extended families (297 individuals, 349 sib pairs) ascertained through index cases with neovascular disease or geographic atrophy. Family and medical history was obtained from index cases and family members. Fundus photographs were taken of all participating family members, and these were graded for severity by use of a quantitative scale. Model-free linkage analysis was performed, and tests of heterogeneity and epistasis were conducted. We have evidence of a major locus on chromosome 15q (GATA50C03 multipoint P=1.98×10-7; empirical P⩽1.0×10-5; single-point P=3.6×10-7). This locus was present as a weak linkage signal in our previous genome scan for ARMD, in the Beaver Dam Eye Study sample (D15S659, multipoint P=.047), but is otherwise novel. In this genome scan, we observed a total of 13 regions on 11 chromosomes (1q31, 2p21, 4p16, 5q34, 9p24, 9q31, 10q26, 12q13, 12q23, 15q21, 16p12, 18p11, and 20q13), with a nominal multipoint significance level of P⩽.01 or LOD ⩾1.18. Family-by-family analysis of the data, performed using model-free linkage methods, suggests that there is evidence of heterogeneity in these families. For example, a single family (family 460) individually shows linkage evidence at 8 loci, at the level of P<.0001. We conducted tests for heterogeneity, which suggest that ARMD susceptibility loci on chromosomes 9p24, 10q26, and 15q21 are not present in all families. We tested for mutations in linked families and examined SNPs in two candidate genes, hemicentin-1 and EFEMP1, in subsamples (145 and 189 sib pairs, respectively) of the data. Mutations were not observed in any of the 11 exons of EFEMP1 nor in exon 104 of hemicentin-1. The SNP analysis for hemicentin-1 on 1q31 suggests that variants within or in very close proximity to this gene cause ARMD pathogenesis. In summary, we have evidence for a major ARMD locus on 15q21, which, coupled with numerous other loci segregating in these families, suggests complex oligogenic patterns of inheritance for ARMD. PMID:14691731

Modelisation numerique de l'hydrologie pour l'aide a la gestion des bassins versants, par l'utilisation conjointe des systemes d'information geographique et de la methode des elements finis un nouvel outil pour le developpement durable SAGESS

NASA Astrophysics Data System (ADS)

Bel Hadj Kacem, Mohamed Salah

All hydrological processes are affected by the spatial variability of the physical parameters of the watershed, and also by human intervention on the landscape. The water outflow from a watershed strictly depends on the spatial and temporal variabilities of the physical parameters of the watershed. It is now apparent that the integration of mathematical models into GIS's can benefit both GIS and three-dimension environmental models: a true modeling capability can help the modeling community bridge the gap between planners, scientists, decision-makers and end-users. The main goal of this research is to design a practical tool to simulate run-off water surface using Geographic design a practical tool to simulate run-off water surface using Geographic Information Systems and the simulation of the hydrological behavior by the Finite Element Method.

Realisation et Applications D'un Laser a Fibre a L'erbium Monofrequence

NASA Astrophysics Data System (ADS)

Larose, Robert

L'incorporation d'ions de terres rares a l'interieur de la matrice de verre d'une fibre optique a permis l'emergence de composants amplificateurs tout-fibre. Le but de cette these consiste d'une part a analyser et a modeliser un tel dispositif et d'autre part, a fabriquer puis a caracteriser un amplificateur et un oscillateur a fibre. A l'aide d'une fibre fortement dopee a l'erbium fabriquee sur demande, on realise un laser a fibre syntonisable qui fonctionne en regime multimodes longitudinaux avec une largeur de raie de 1.5 GHz et egalement comme source monofrequencielle de largeur de raie de 70 kHz. Le laser sert ensuite a caracteriser un reseau de Bragg ecrit par photosensibilite dans une fibre optique. La technique de syntonisation permet aussi l'asservissement au fond d'une resonance de l'acetylene. Le laser garde alors la position centrale de la raie avec une erreur de moins de 1 MHz corrigeant ainsi les derives mecaniques de la cavite.

Modelisation des emissions de particules microniques et nanometriques en usinage

NASA Astrophysics Data System (ADS)

Khettabi, Riad

La mise en forme des pieces par usinage emet des particules, de tailles microscopiques et nanometriques, qui peuvent etre dangereuses pour la sante. Le but de ce travail est d'etudier les emissions de ces particules pour fins de prevention et reduction a la source. L'approche retenue est experimentale et theorique, aux deux echelles microscopique et macroscopique. Le travail commence par des essais permettant de determiner les influences du materiau, de l'outil et des parametres d'usinage sur les emissions de particules. E nsuite un nouveau parametre caracterisant les emissions, nomme Dust unit , est developpe et un modele predictif est propose. Ce modele est base sur une nouvelle theorie hybride qui integre les approches energetiques, tribologiques et deformation plastique, et inclut la geometrie de l'outil, les proprietes du materiau, les conditions de coupe et la segmentation des copeaux. Il ete valide au tournage sur quatre materiaux: A16061-T6, AISI1018, AISI4140 et fonte grise.

Comparison of different 3D wavefront sensing and reconstruction techniques for MCAO

NASA Astrophysics Data System (ADS)

Bello, Dolores; Vérinaud, Christophe; Conan, Jean-Marc; Fusco, Thierry; Carbillet, Marcel; Esposito, Simone

2003-02-01

The vertical distribution of the turbulence limits the field of view of classical adaptive optics due to the anisoplanatism. Multiconjugate adaptive optics (MCAO) uses several deformable mirrors conjugated to different layers in the atmosphere to overcome this effect. In the last few years, many studies and developments have been done regarding the analysis of the turbulence volume, and the choice of the wavefront reconstruction techniques.An extensive study of MCAO modelisation and performance estimation has been done at OAA and ONERA. The developed Monte Carlo codes allow to simulate and investigate many aspects: comparison of turbulence analysis strategies (tomography or layer oriented) and comparison of different reconstruction approaches. For instance in the layer oriented approach, the control for a given deformable mirror can be either deduced from the whole set of wavefront sensor measurements or only using the associated wavefront sensor. Numerical simulations are presented showing the advantages and disadvantages of these different options for several cases depending on the number, geometry and magnitude of the guide stars.

Structural elements and organization of the ancestral translational machinery

NASA Technical Reports Server (NTRS)

Rein, R.; Srinivasan, S.; Mcdonald, J.; Raghunathan, G.; Shibata, M.

1987-01-01

The molecular mechanisms of the primitive translational apparatus are discussed in the framework of present-day protein biosynthesis. The structural necessities of an early adaptor and the multipoint recognition properties of such an adaptor are investigated on the basis of structure/function relationships found in a contemporary system and a molecular model of the contemporary transpeptidation complex. A model of the tRNA(Tyr)-tyrosyl tRNA synthetase complex including the positioning of the disordered region is proposed; the model is used to illustrate the required recognition properties of the ancestor aminoacyl synthetase.

Analytical study of pressure balancing in gas film seals

NASA Technical Reports Server (NTRS)

Zuk, J.

1973-01-01

The load factor is investigated for subsonic and choked flow conditions, laminar and turbulent flows, and various seal entrance conditions. Both parallel sealing surfaces and surfaces with small linear deformation were investigated. The load factor for subsonic flow depends strongly on pressure ratio; under choked flow conditions, however the load factor is found to depend more strongly on film thickness and flow entrance conditions rather than pressure ratio. The importance of generating hydrodynamic forces to keep the seal balanced under severe and multipoint operation is also discussed.

Technical and economic feasibility of integrated video service by satellite

NASA Technical Reports Server (NTRS)

Price, Kent M.; Garlow, R. K.; Henderson, T. R.; Kwan, Robert K.; White, L. W.

1992-01-01

The trends and roles of satellite based video services in the year 2010 time frame are examined based on an overall network and service model for that period. Emphasis is placed on point to point and multipoint service, but broadcast could also be accommodated. An estimate of the video traffic is made and the service and general network requirements are identified. User charges are then estimated based on several usage scenarios. In order to accommodate these traffic needs, a 28 spot beam satellite architecture with on-board processing and signal mixing is suggested.

Rainbow tensor model with enhanced symmetry and extreme melonic dominance

NASA Astrophysics Data System (ADS)

Itoyama, H.; Mironov, A.; Morozov, A.

2017-08-01

We introduce and briefly analyze the rainbow tensor model where all planar diagrams are melonic. This leads to considerable simplification of the large N limit as compared to that of the matrix model: in particular, what are dressed in this limit are propagators only, which leads to an oversimplified closed set of Schwinger-Dyson equations for multi-point correlators. We briefly touch upon the Ward identities, the substitute of the spectral curve and the AMM/EO topological recursion and their possible connections to Connes-Kreimer theory and forest formulas.

Temperature measurement systems in wearable electronics

NASA Astrophysics Data System (ADS)

Walczak, S.; Gołebiowski, J.

2014-08-01

The aim of this paper is to present the concept of temperature measurement system, adapted to wearable electronics applications. Temperature is one of the most commonly monitored factor in smart textiles, especially in sportswear, medical and rescue products. Depending on the application, measured temperature could be used as an initial value of alert, heating, lifesaving or analysis system. The concept of the temperature measurement multi-point system, which consists of flexible screen-printed resistive sensors, placed on the T-shirt connected with the central unit and the power supply is elaborated in the paper.

Optimization of Turbine Engine Cycle Analysis with Analytic Derivatives

NASA Technical Reports Server (NTRS)

Hearn, Tristan; Hendricks, Eric; Chin, Jeffrey; Gray, Justin; Moore, Kenneth T.

2016-01-01

A new engine cycle analysis tool, called Pycycle, was recently built using the OpenMDAO framework. This tool uses equilibrium chemistry based thermodynamics, and provides analytic derivatives. This allows for stable and efficient use of gradient-based optimization and sensitivity analysis methods on engine cycle models, without requiring the use of finite difference derivative approximation methods. To demonstrate this, a gradient-based design optimization was performed on a multi-point turbofan engine model. Results demonstrate very favorable performance compared to an optimization of an identical model using finite-difference approximated derivatives.

Self-Powered High-Resolution and Pressure-Sensitive Triboelectric Sensor Matrix for Real-Time Tactile Mapping.

PubMed

Wang, Xiandi; Zhang, Hanlu; Dong, Lin; Han, Xun; Du, Weiming; Zhai, Junyi; Pan, Caofeng; Wang, Zhong Lin

2016-04-20

A triboelectric sensor matrix (TESM) can accurately track and map 2D tactile sensing. A self-powered, high-resolution, pressure-sensitive, flexible and durable TESM with 16 × 16 pixels is fabricated for the fast detection of single-point and multi-point touching. Using cross-locating technology, a cross-type TESM with 32 × 20 pixels is developed for more rapid tactile mapping, which significantly reduces the addressing lines from m × n to m + n. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A numerically efficient finite element hydroelastic analysis. Volume 2: Implementation in NASTRAN, part 1

NASA Technical Reports Server (NTRS)

Coppolino, R. N.

1974-01-01

Details are presented of the implementation of the new formulation into NASTRAN including descriptions of the DMAP statements required for conversion of the program and details pertaining to problem definition and bulk data considerations. Details of the current 1/8-scale space shuttle external tank mathematical model, numerical results and analysis/test comparisons are also presented. The appendices include a description and listing of a FORTRAN program used to develop harmonic transformation bulk data (multipoint constraint statements) and sample bulk data information for a number of hydroelastic problems.

Regard epistemique sur une evolution conceptuelle en physique au secondaire

NASA Astrophysics Data System (ADS)

Potvin, Patrice

The thesis, which is in continuity with Legendre's (1993) work, deals with qualitative understanding of physics notions at the secondary level. It attempts to identify and to label, in the verbalizations of 12 to 16 year-old students, the tendencies that guide their cognitive itineraries through the exploration of problem-situations. The hypotheses of work are about modelisations, conceptions and p-prims. These last objects are seen, in DiSessa's epistemological perspective, as a type of habit that influences the determination of links between the parameters of a problem. In other words, they coordinate logically and mathematically. Methodology is based on explicitation interviews. This type of interview authorizes verbalizations that involve an "intuitive sense" of mechanics. Twenty students are invited to share their evocations as they explore the logics of a computerized microworld. This microworld has been programmed on the "Interactive Physics(TM)" software and is made of five different situations that involve speed, acceleration, mass, force and inertia. The situations are presented to the students from the least to the most complex. An analysis of the verbalizations of the five students shows the existence of elements that play a role in modelisation and qualitative construction of comprehension as well as in its qualitative/quantitative articulation. Results indicate the presence of coordinative habits easily discernible. P-prims appear to play an important part in the construction of models and in the determination of links between the variables of a problem. The analysis of the results allows to see that conceptions are not so important pieces in comprehension. As such, they seem phenotypic. Also, analysis allows to recognize the difficulty to understand properly the inverse relation (1/x) and its asymptotic nature. The "p-prim" analysis also establishes the possibility to analyze not only efficient and inefficient intuitions, but also the cognitive itineraries of students working to construct the logic of the movement of a "ball" as a whole. Implications of the thesis are, among others, at the praxic level; it becomes possible to imagine sequences of learning and teaching physics that are based on the consideration of p-prims despite the implicit nature of these objects. This is a truly constructivist practice which establishes bridges between novice and expert knowledge because there are p-prims in both of them. As so, the thesis acknowledges a perspective of learning inscribed in "continuity". It also proposes a fertile theoretical ground for the comprehension of physics.

Algorithmes de couplage RANS et ecoulement potentiel

NASA Astrophysics Data System (ADS)

Gallay, Sylvain

Dans le processus de developpement d'avion, la solution retenue doit satisfaire de nombreux criteres dans de nombreux domaines, comme par exemple le domaine de la structure, de l'aerodynamique, de la stabilite et controle, de la performance ou encore de la securite, tout en respectant des echeanciers precis et minimisant les couts. Les geometries candidates sont nombreuses dans les premieres etapes de definition du produit et de design preliminaire, et des environnements d'optimisations multidisciplinaires sont developpes par les differentes industries aeronautiques. Differentes methodes impliquant differents niveaux de modelisations sont necessaires pour les differentes phases de developpement du projet. Lors des phases de definition et de design preliminaires, des methodes rapides sont necessaires afin d'etudier les candidats efficacement. Le developpement de methodes ameliorant la precision des methodes existantes tout en gardant un cout de calcul faible permet d'obtenir un niveau de fidelite plus eleve dans les premieres phases de developpement du projet et ainsi grandement diminuer les risques associes. Dans le domaine de l'aerodynamisme, les developpements des algorithmes de couplage visqueux/non visqueux permettent d'ameliorer les methodes de calcul lineaires non visqueuses en methodes non lineaires prenant en compte les effets visqueux. Ces methodes permettent ainsi de caracteriser l'ecoulement visqueux sur les configurations et predire entre autre les mecanismes de decrochage ou encore la position des ondes de chocs sur les surfaces portantes. Cette these se focalise sur le couplage entre une methode d'ecoulement potentiel tridimensionnelle et des donnees de section bidimensionnelles visqueuses. Les methodes existantes sont implementees et leurs limites identifiees. Une methode originale est ensuite developpee et validee. Les resultats sur une aile elliptique demontrent la capacite de l'algorithme a de grands angles d'attaques et dans la region post-decrochage. L'algorithme de couplage a ete compare a des donnees de plus haute fidelite sur des configurations issues de la litterature. Un modele de fuselage base sur des relations empiriques et des simulations RANS a ete teste et valide. Les coefficients de portance, de trainee et de moment de tangage ainsi que les coefficients de pression extraits le long de l'envergure ont montre un bon accord avec les donnees de soufflerie et les modeles RANS pour des configurations transsoniques. Une configuration a geometrie hypersustentatoire a permis d'etudier la modelisation des surfaces hypersustentees de la methode d'ecoulement potentiel, demontrant que la cambrure peut etre prise en compte uniquement dans les donnees visqueuses.

Linkage analysis of juvenile myoclonic epilepsy and microsatellite loci spanning 61 cM of human chromosome 6p in 19 nuclear pedigrees provides no evidence for a susceptibility locus in this region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elmslie, F.V.; Williamson, M.P.; Rees, M.

1996-09-01

Linkage analysis in separately ascertained families of probands with juvenile myoclonic epilepsy (JME) has previously provided evidence both for and against the existence of a locus (designated {open_quotes}EJM1{close_quotes}), on chromosome 6p, predisposing to a trait defined as either clinical JME, its associated electroencephalographic abnormality, or idiopathic generalized epilepsy. Linkage analysis was performed in 19 families in which a proband and at least one first- or two second-degree relatives have clinical JME. Family members were typed for seven highly polymorphic microsatellite markers on chromosome 6p: D6S260, D6S276, D6S291, D6S271, D6S465, D6S257, and D6S254. Pairwise and multipoint linkage analysis was carried outmore » under the assumptions of autosomal dominant inheritance at 70% and 50% penetrance and autosomal recessive inheritance at 70% and 50% penetrance. No significant evidence in favor of linkage to the clinical trait of JME was obtained for any locus. The region formally excluded (LOD score <-2) by using multipoint analysis varies depending on the assumptions made concerning inheritance parameters and the proportion of linked families, {alpha} - that is, the degree of locus heterogeneity. Further analysis either classifying all unaffected individuals as unknown or excluding a subset of four families in which pyknoleptic absence seizures were present in one or more individuals did not alter these conclusions. 24 refs., 4 figs., 1 tab.« less

A study comparing precision of the maximum multipoint heterogeneity LOD statistic to three model-free multipoint linkage methods.

PubMed

Finch, S J; Chen, C H; Gordon, D; Mendell, N R

2001-12-01

This study compared the performance of the maximum lod (MLOD), maximum heterogeneity lod (MHLOD), maximum non-parametric linkage score (MNPL), maximum Kong and Cox linear extension (MKC(lin)) of NPL, and maximum Kong and Cox exponential extension (MKC(exp)) of NPL as calculated in Genehunter 1.2 and Genehunter-Plus. Our performance measure was the distance between the marker with maximum value for each linkage statistic and the trait locus. We performed a simulation study considering: 1) four modes of transmission, 2) 100 replicates for each model, 3) 58 pedigrees (with 592 subjects) per replicate, 4) three linked marker loci each having three equally frequent alleles, and 5) either 0% unlinked families (linkage homogeneity) or 50% unlinked families (linkage heterogeneity). For each replicate, we obtained the Haldane map position of the location at which each of the five statistics is maximized. The MLOD and MHLOD were obtained by maximizing over penetrances, phenocopy rate, and risk-allele frequencies. For the models simulated, MHLOD appeared to be the best statistic both in terms of identifying a marker locus having the smallest mean distance from the trait locus and in terms of the strongest negative correlation between maximum linkage statistic and distance of the identified position and the trait locus. The marker loci with maximum value of the Kong and Cox extensions of the NPL statistic also were closer to the trait locus than the marker locus with maximum value of the NPL statistic. Copyright 2001 Wiley-Liss, Inc.

Application of chiral critical clusters to assymetric synthesis

DOEpatents

Ferrieri, Richard A.

2002-01-01

Disclosed is a composition, a method of making and a method of using critical clusters for asymmetric synthesis using substantially optically-pure chiral solvent molecules in a supercritical fluid. The solvent molecules are capable of forming a multipoint hydrogen bonded solvate as they encage at least one solute molecule. The encaged solute molecule is capable of reacting to form an optically active chiral center. In another aspect, there is disclosed a method of directing the position of bonding between a solute molecule and a ligand involving encaging the solute molecule and the ligand with polar solvent molecules in a supercritical fluid under conditions of temperature and pressure sufficient to change electric charge distribution in the solute molecule. In yet another aspect, disclosed is a method of making pharmaceutical compounds involving encaging a solute molecule, which is capable of forming a chiral center, and a ligand with polar solvent molecules in a supercritical fluid under conditions of temperature and pressure sufficient to change electric charge distribution of the solute molecule. The solute molecule and ligand are then reacted whereby the ligand bonds to the solute molecule forming a chiral center. Also disclosed is a method for racemic resolution using critical clusters involving encaging racemic mixtures of solute molecules with substantially optically-pure chiral solvent molecules in a supercritical fluid under conditions of temperature and pressure sufficient to form critical clusters. The solvent molecules are capable of multipoint hydrogen bonding with the solute molecules. The encaged solute molecules are then nonenzymatically reacted to enhance the optical purity of the solute molecules.

Research on an uplink carrier sense multiple access algorithm of large indoor visible light communication networks based on an optical hard core point process.

PubMed

Nan, Zhufen; Chi, Xuefen

2016-12-20

The IEEE 802.15.7 protocol suggests that it could coordinate the channel access process based on the competitive method of carrier sensing. However, the directionality of light and randomness of diffuse reflection would give rise to a serious imperfect carrier sense (ICS) problem [e.g., hidden node (HN) problem and exposed node (EN) problem], which brings great challenges in realizing the optical carrier sense multiple access (CSMA) mechanism. In this paper, the carrier sense process implemented by diffuse reflection light is modeled as the choice of independent sets. We establish an ICS model with the presence of ENs and HNs for the multi-point to multi-point visible light communication (VLC) uplink communications system. Considering the severe optical ICS problem, an optical hard core point process (OHCPP) is developed, which characterizes the optical CSMA for the indoor VLC uplink communications system. Due to the limited coverage of the transmitted optical signal, in our OHCPP, the ENs within the transmitters' carrier sense region could be retained provided that they could not corrupt the ongoing communications. Moreover, because of the directionality of both light emitting diode (LED) transmitters and receivers, theoretical analysis of the HN problem becomes difficult. In this paper, we derive the closed-form expression for approximating the outage probability and transmission capacity of VLC networks with the presence of HNs and ENs. Simulation results validate the analysis and also show the existence of an optimal physical carrier-sensing threshold that maximizes the transmission capacity for a given emission angle of LED.

Positive Charges on the Surface of Thaumatin Are Crucial for the Multi-Point Interaction with the Sweet Receptor.

PubMed

Masuda, Tetsuya; Kigo, Satomi; Mitsumoto, Mayuko; Ohta, Keisuke; Suzuki, Mamoru; Mikami, Bunzo; Kitabatake, Naofumi; Tani, Fumito

2018-01-01

Thaumatin, an intensely sweet-tasting protein, elicits sweet taste with a threshold of only 50 nM. Previous studies from our laboratory suggested that the complex model between the T1R2-T1R3 sweet receptor and thaumatin depends critically on the complementarity of electrostatic potentials. In order to further validate this model, we focused on three lysine residues (Lys78, Lys106, and Lys137), which were expected to be part of the interaction sites. Three thaumatin mutants (K78A, K106A, and K137A) were prepared and their threshold values of sweetness were examined. The results showed that the sweetness of K106A was reduced by about three times and those of K78A and K137A were reduced by about five times when compared to wild-type thaumatin. The three-dimensional structures of these mutants were also determined by X-ray crystallographic analyses at atomic resolutions. The overall structures of mutant proteins were similar to that of wild-type but the electrostatic potentials around the mutated sites became more negative. Since the three lysine residues are located in 20-40 Å apart each other on the surface of thaumatin molecule, these results suggest the positive charges on the surface of thaumatin play a crucial role in the interaction with the sweet receptor, and are consistent with a large surface is required for interaction with the sweet receptor, as proposed by the multipoint interaction model named wedge model.

In vivo visualization method by absolute blood flow velocity based on speckle and fringe pattern using two-beam multipoint laser Doppler velocimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kyoden, Tomoaki, E-mail: kyouden@nc-toyama.ac.jp; Naruki, Shoji; Akiguchi, Shunsuke

Two-beam multipoint laser Doppler velocimetry (two-beam MLDV) is a non-invasive imaging technique able to provide an image of two-dimensional blood flow and has potential for observing cancer as previously demonstrated in a mouse model. In two-beam MLDV, the blood flow velocity can be estimated from red blood cells passing through a fringe pattern generated in the skin. The fringe pattern is created at the intersection of two beams in conventional LDV and two-beam MLDV. Being able to choose the depth position is an advantage of two-beam MLDV, and the position of a blood vessel can be identified in a three-dimensionalmore » space using this technique. Initially, we observed the fringe pattern in the skin, and the undeveloped or developed speckle pattern generated in a deeper position of the skin. The validity of the absolute velocity value detected by two-beam MLDV was verified while changing the number of layers of skin around a transparent flow channel. The absolute velocity value independent of direction was detected using the developed speckle pattern, which is created by the skin construct and two beams in the flow channel. Finally, we showed the relationship between the signal intensity and the fringe pattern, undeveloped speckle, or developed speckle pattern based on the skin depth. The Doppler signals were not detected at deeper positions in the skin, which qualitatively indicates the depth limit for two-beam MLDV.« less

The sumLINK statistic for genetic linkage analysis in the presence of heterogeneity.

PubMed

Christensen, G B; Knight, S; Camp, N J

2009-11-01

We present the "sumLINK" statistic--the sum of multipoint LOD scores for the subset of pedigrees with nominally significant linkage evidence at a given locus--as an alternative to common methods to identify susceptibility loci in the presence of heterogeneity. We also suggest the "sumLOD" statistic (the sum of positive multipoint LOD scores) as a companion to the sumLINK. sumLINK analysis identifies genetic regions of extreme consistency across pedigrees without regard to negative evidence from unlinked or uninformative pedigrees. Significance is determined by an innovative permutation procedure based on genome shuffling that randomizes linkage information across pedigrees. This procedure for generating the empirical null distribution may be useful for other linkage-based statistics as well. Using 500 genome-wide analyses of simulated null data, we show that the genome shuffling procedure results in the correct type 1 error rates for both the sumLINK and sumLOD. The power of the statistics was tested using 100 sets of simulated genome-wide data from the alternative hypothesis from GAW13. Finally, we illustrate the statistics in an analysis of 190 aggressive prostate cancer pedigrees from the International Consortium for Prostate Cancer Genetics, where we identified a new susceptibility locus. We propose that the sumLINK and sumLOD are ideal for collaborative projects and meta-analyses, as they do not require any sharing of identifiable data between contributing institutions. Further, loci identified with the sumLINK have good potential for gene localization via statistical recombinant mapping, as, by definition, several linked pedigrees contribute to each peak.

LSI-based amperometric sensor for bio-imaging and multi-point biosensing.

PubMed

Inoue, Kumi Y; Matsudaira, Masahki; Kubo, Reyushi; Nakano, Masanori; Yoshida, Shinya; Matsuzaki, Sakae; Suda, Atsushi; Kunikata, Ryota; Kimura, Tatsuo; Tsurumi, Ryota; Shioya, Toshihito; Ino, Kosuke; Shiku, Hitoshi; Satoh, Shiro; Esashi, Masayoshi; Matsue, Tomokazu

2012-09-21

We have developed an LSI-based amperometric sensor called "Bio-LSI" with 400 measurement points as a platform for electrochemical bio-imaging and multi-point biosensing. The system is comprised of a 10.4 mm × 10.4 mm CMOS sensor chip with 20 × 20 unit cells, an external circuit box, a control unit for data acquisition, and a DC power box. Each unit cell of the chip contains an operational amplifier with a switched-capacitor type I-V converter for in-pixel signal amplification. We successfully realized a wide dynamic range from ±1 pA to ±100 nA with a well-organized circuit design and operating software. In particular, in-pixel signal amplification and an original program to control the signal read-out contribute to the lower detection limit and wide detection range of Bio-LSI. The spacial resolution is 250 μm and the temporal resolution is 18-125 ms/400 points, which depends on the desired current detection range. The coefficient of variance of the current for 400 points is within 5%. We also demonstrated the real-time imaging of a biological molecule using Bio-LSI. The LSI coated with an Os-HRP film was successfully applied to the monitoring of the changes of hydrogen peroxide concentration in a flow. The Os-HRP-coated LSI was spotted with glucose oxidase and used for bioelectrochemical imaging of the glucose oxidase (GOx)-catalyzed oxidation of glucose. Bio-LSI is a promising platform for a wide range of analytical fields, including diagnostics, environmental measurements and basic biochemistry.

An integrated optimum design approach for high speed prop rotors

NASA Technical Reports Server (NTRS)

Chattopadhyay, Aditi; Mccarthy, Thomas R.

1995-01-01

The objective is to develop an optimization procedure for high-speed and civil tilt-rotors by coupling all of the necessary disciplines within a closed-loop optimization procedure. Both simplified and comprehensive analysis codes are used for the aerodynamic analyses. The structural properties are calculated using in-house developed algorithms for both isotropic and composite box beam sections. There are four major objectives of this study. (1) Aerodynamic optimization: The effects of blade aerodynamic characteristics on cruise and hover performance of prop-rotor aircraft are investigated using the classical blade element momentum approach with corrections for the high lift capability of rotors/propellers. (2) Coupled aerodynamic/structures optimization: A multilevel hybrid optimization technique is developed for the design of prop-rotor aircraft. The design problem is decomposed into a level for improved aerodynamics with continuous design variables and a level with discrete variables to investigate composite tailoring. The aerodynamic analysis is based on that developed in objective 1 and the structural analysis is performed using an in-house code which models a composite box beam. The results are compared to both a reference rotor and the optimum rotor found in the purely aerodynamic formulation. (3) Multipoint optimization: The multilevel optimization procedure of objective 2 is extended to a multipoint design problem. Hover, cruise, and take-off are the three flight conditions simultaneously maximized. (4) Coupled rotor/wing optimization: Using the comprehensive rotary wing code CAMRAD, an optimization procedure is developed for the coupled rotor/wing performance in high speed tilt-rotor aircraft. The developed procedure contains design variables which define the rotor and wing planforms.

Adsorption de gaz sur les materiaux microporeux modelisation, thermodynamique et applications

NASA Astrophysics Data System (ADS)

Richard, Marc-Andre

2009-12-01

Nos travaux sur l'adsorption de gaz dans les materiaux microporeux s'inscrivent dans le cadre des recherches visant a augmenter l'efficacite du stockage de l'hydrogene a bord des vehicules. Notre objectif etait d'etudier la possibilite d'utiliser l'adsorption afin d'ameliorer l'efficacite de la liquefaction de l'hydrogene des systemes a petite echelle. Nous avons egalement evalue les performances d'un systeme de stockage cryogenique de l'hydrogene base sur la physisorption. Comme nous avons affaire a des plages de temperatures particulierement etendues et a de hautes pressions dans la region supercritique du gaz, nous avons du commencer par travailler sur la modelisation et la thermodynamique de l'adsorption. La representation de la quantite de gaz adsorbee en fonction de la temperature et de la pression par un modele semi-empirique est un outil utile pour determiner la masse de gaz adsorbee dans un systeme mais egalement pour calculer les effets thermiques lies a l'adsorption. Nous avons adapte le modele Dubinin-Astakhov (D-A) pour modeliser des isothermes d'adsorption d'hydrogene, d'azote et de methane sur du charbon actif a haute pression et sur une grande plage de temperatures supercritiques en considerant un volume d'adsorption invariant. Avec cinq parametres de regression (incluant le volume d'adsorption Va), le modele que nous avons developpe permet de tres bien representer des isothermes experimentales d'adsorption d'hydrogene (de 30 a 293 K, jusqu'a 6 MPa), d'azote (de 93 a 298 K, jusqu'a 6 MPa) et de methane (de 243 a 333 K, jusqu'a 9 MPa) sur le charbon actif. Nous avons calcule l'energie interne de la phase adsorbee a partir du modele en nous servant de la thermodynamique des solutions sans negliger le volume d'adsorption. Par la suite, nous avons presente les equations de conservation de la niasse et de l'energie pour un systeme d'adsorption et valide notre demarche en comparant des simulations et des tests d'adsorption et de desorption. En plus de l'energie interne, nous avons evalue l'entropie, l'energie differentielle d'adsorption et la chaleur isosterique d'adsorption. Nous avons etudie la performance d'un systeme de stockage d'hydrogene par adsorption pour les vehicules. La capacite de stockage d'hydrogene et les performances thermiques d'un reservoir de 150 L contenant du charbon actif Maxsorb MSC-30(TM) (surface specifique ˜ 3000 m2/g) ont ete etudiees sur une plage de temperatures de 60 a 298 K et a des pressions allant jusqu'a 35 MPa. Le systeme a ete considere de facon globale, sans nous attarder a un design particulier. Il est possible de stocker 5 kg d'hydrogene a des pressions de 7.8, 15.2 et 29 MPa pour des temperatures respectivement de 80, 114 et 172 K, lorsqu'on recupere l'hydrogene residuel a 2.5 bars en le chauffant. La simulation des phenomenes thermiques nous a permis d'analyser le refroidissement necessaire lors du remplissage, le chauffage lors de la decharge et le temps de dormance. Nous avons developpe un cycle de liquefaction de l'hydrogene base sur l'adsorption avec compression mecanique (ACM) et avons evalue sa faisabilite. L'objectif etait d'augmenter sensiblement l'efficacite des systemes de liquefaction de l'hydrogene a petite echelle (moins d'une tonne/jour) et ce, sans en augmenter le cout en capital. Nous avons adapte le cycle de refrigeration par ACM afin qu'il puisse par la suite etre ajoute a un cycle de liquefaction de l'hydrogene. Nous avons ensuite simule des cycles idealises de refrigeration par ACM. Meme dans ces conditions ideales, la refrigeration specifique est faible. De plus, l'efficacite theorique maximale de ces cycles de refrigeration est d'environ 20 a 30% de l'ideal. Nous avons realise experimentalement un cycle de refrigeration par ACM avec le couple azote/charbon actif. (Abstract shortened by UMI.)

Control and automation of the Pegasus multi-point Thomson scattering system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bodner, G. M., E-mail: gbodner@wisc.edu; Bongard, M. W.; Fonck, R. J.

A new control system for the Pegasus Thomson scattering diagnostic has recently been deployed to automate the laser operation, data collection process, and interface with the system-wide Pegasus control code. Automation has been extended to areas outside of data collection, such as manipulation of beamline cameras and remotely controlled turning mirror actuators to enable intra-shot beam alignment. Additionally, the system has been upgraded with a set of fast (∼1 ms) mechanical shutters to mitigate contamination from background light. Modification and automation of the Thomson system have improved both data quality and diagnostic reliability.

Control and automation of the Pegasus multi-point Thomson scattering system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bodner, Grant M.; Bongard, Michael W.; Fonck, Raymond J.

A new control system for the Pegasus Thomson scattering diagnostic has recently been deployed to automate the laser operation, data collection process, and interface with the system-wide Pegasus control code. Automation has been extended to areas outside of data collection, such as manipulation of beamline cameras and remotely controlled turning mirror actuators to enable intra-shot beam alignment. In addition, the system has been upgraded with a set of fast (~1 ms) mechanical shutters to mitigate contamination from background light. Modification and automation of the Thomson system have improved both data quality and diagnostic reliability.

The gene for creatine kinase, mitochondrial 2 (sarcomeric; CKMT2), maps to chromosome 5q13. 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richard, I.; Devaud, C.; Cherif, D.

1993-10-01

YAC clones for the creatine kinase, mitochrondial 2 (sarcomeric; CKMT2), gene were isolated. One of these YACs was localized on chromosome 5q13.3 by fluorescence in situ hybridization. A polymorphic dinucleotide repeat (heterozygosity 0.77) was identified within the seventh intron of the CKMT2 gene. Genotyping of CEPH families allowed positioning of CKMT2 on the multipoint map of chromosome 5 between D5S424 and D5S428, distal to spinal muscular atrophy (SMA) (5q12-q14). 8 refs., 1 fig., 2 tabs.

THEMIS Observations of Unusual Bow Shock Motion, Attending a Transient Magnetospheric Event

NASA Technical Reports Server (NTRS)

Korotova, Galina; Sibeck, David; Omidi, N.; Angelopoulos, V.

2013-01-01

We present a multipoint case study of solar wind and magnetospheric observations during a transient magnetospheric compression at 2319 UT on October 15, 2008. We use high-time resolution magnetic field and plasma data from the THEMIS and GOES-11/12 spacecraft to show that this transient event corresponded to an abrupt rotation in the IMF orientation, a change in the location of the foreshock, and transient outward bow shock motion. We employ results from a global hybrid code model to reconcile the observations indicating transient inward magnetopause motion with the outward bow shock motion.

Magnetic field gradients inferred from multi-point measurements of Cluster FGM and EDI

NASA Astrophysics Data System (ADS)

Teubenbacher, Robert; Nakamura, Rumi; Giner, Lukas; Plaschke, Ferdinand; Baumjohann, Wolfgang; Magnes, Werner; Eichelberger, Hans; Steller, Manfred; Torbert, Roy

2013-04-01

We use Cluster data from fluxgate magnetometer (FGM) and electron drift instrument (EDI) to determine the magnetic field gradients in the near-Earth magnetotail. Here we use the magnetic field data from FGM measurements as well as the gyro-time data of electrons determined from the time of flight measurements of EDI. The results are compared with the values estimated from empirical magnetic field models for different magnetospheric conditions. We also estimated the spin axis offset of FGM based on comparison between EDI and FGM data and discuss the possible effect in determining the current sheet characteristics.

Microcomputer keeps watch at Emerald Mine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1987-04-01

This paper reviews the computerized mine monitoring system set up at the Emerald Mine, SW Pennsylvania, USA. This coal mine has pioneered the automation of many production and safety features and this article covers their work in fire detection and conveyor belt monitoring. A central computer control room can safely watch over the whole underground mining operation using one 25 inch colour monitor. These new data-acquisition systems will lead the way, in the future, to safer move efficient coal mining. Multi-point monitoring of carbon monoxide, heat anomalies, toxic gases and the procedures in conveyor belt operation from start-up to closedown.

Control and automation of the Pegasus multi-point Thomson scattering system

DOE PAGES

Bodner, Grant M.; Bongard, Michael W.; Fonck, Raymond J.; ...

2016-08-12

A new control system for the Pegasus Thomson scattering diagnostic has recently been deployed to automate the laser operation, data collection process, and interface with the system-wide Pegasus control code. Automation has been extended to areas outside of data collection, such as manipulation of beamline cameras and remotely controlled turning mirror actuators to enable intra-shot beam alignment. In addition, the system has been upgraded with a set of fast (~1 ms) mechanical shutters to mitigate contamination from background light. Modification and automation of the Thomson system have improved both data quality and diagnostic reliability.

Thermal Modeling and Testing of the Edison Demonstration of Smallsat Networks Project

NASA Technical Reports Server (NTRS)

Coker, Robert

2014-01-01

NASA's Edison program is intending to launch the Edison Demonstration of Smallsat Networks (EDSN) project, a swarm of 8 1.5U cubesats in the fall of 2014 to demonstrate intra-swarm communications and multi-point in situ space physics data acquisition. Due to late changes in the duty cycles of various components, potential overheating issues appeared. In addition, it was determined that capacity loss due to the coldness of the batteries was unacceptable, so mitigation was required. This paper will discuss the thermal modeling, testing, and results of the EDSN mission.

Non-military microwave applications

NASA Astrophysics Data System (ADS)

Bierman, Howard

1990-04-01

The nonmilitary applications of microwave technology in medicine, communications, and agriculture are discussed. Particular attention is given to a microwave multichannel multipoint video distribution system (a broadcasting system with up to 20 programs drawn from satellites, video tape libraries, and locally generated material); microwaves used in DBS distribution; satellite receivers for data communications; microwave thermography used for early cancer detection, brain temperature measurements, and appendicitis diagnosis; an experimental Doppler radar assembly for guiding robots walking on a factory floor; and an agricultural application where microwaves are used to break down slugs in soil and thus improve potato and grain crops. Schematic diagrams are included.

Statistical turbulence theory and turbulence phenomenology

NASA Technical Reports Server (NTRS)

Herring, J. R.

1973-01-01

The application of deductive turbulence theory for validity determination of turbulence phenomenology at the level of second-order, single-point moments is considered. Particular emphasis is placed on the phenomenological formula relating the dissipation to the turbulence energy and the Rotta-type formula for the return to isotropy. Methods which deal directly with most or all the scales of motion explicitly are reviewed briefly. The statistical theory of turbulence is presented as an expansion about randomness. Two concepts are involved: (1) a modeling of the turbulence as nearly multipoint Gaussian, and (2) a simultaneous introduction of a generalized eddy viscosity operator.

Weighted cubic and biharmonic splines

NASA Astrophysics Data System (ADS)

Kvasov, Boris; Kim, Tae-Wan

2017-01-01

In this paper we discuss the design of algorithms for interpolating discrete data by using weighted cubic and biharmonic splines in such a way that the monotonicity and convexity of the data are preserved. We formulate the problem as a differential multipoint boundary value problem and consider its finite-difference approximation. Two algorithms for automatic selection of shape control parameters (weights) are presented. For weighted biharmonic splines the resulting system of linear equations can be efficiently solved by combining Gaussian elimination with successive over-relaxation method or finite-difference schemes in fractional steps. We consider basic computational aspects and illustrate main features of this original approach.

Program for the solution of multipoint boundary value problems of quasilinear differential equations

NASA Technical Reports Server (NTRS)

1973-01-01

Linear equations are solved by a method of superposition of solutions of a sequence of initial value problems. For nonlinear equations and/or boundary conditions, the solution is iterative and in each iteration a problem like the linear case is solved. A simple Taylor series expansion is used for the linearization of both nonlinear equations and nonlinear boundary conditions. The perturbation method of solution is used in preference to quasilinearization because of programming ease, and smaller storage requirements; and experiments indicate that the desired convergence properties exist although no proof or convergence is given.

Lipid-based nanotubes as functional architectures with embedded fluorescence and recognition capabilities.

PubMed

John, George; Mason, Megan; Ajayan, Pulickel M; Dordick, Jonathan S

2004-11-24

A limited combinatorial strategy was used to synthesize a small library of soft lipid-based materials ranging from structurally unordered fibers to highly uniform nanotubes. The latter nanotubes are comprised of a bilayer structure with interdigitated alkyl chains associated through hydrophobic interactions. These tubes contain accessible 2,6-diaminopyridine linkers that can interact with thymidine and related nucleosides through multipoint hydrogen bonding, thereby quenching the intrinsic fluorescence of the aromatic linker. These results are the first example of a systematic strategy to design functional lipid nanotubes with precise structural and functional features.

[Regulation of thermal stability of enzymes by changing the composition of media. Native and modified alpha-chymotrypsin].

PubMed

Levitskiĭ, V Iu; Melik-Nubarov, N S; Slepnev, V I; Shikshnis, V A; Mozhaev, V V

1990-01-01

Stabilizing effect of denaturing salts on irreversible thermoinactivation of native and modified alpha-chymotrypsin at elevated temperatures is observed. The effect is caused by a shift of conformational equilibrium, at the primary step of reversible unfolding in the course of thermoinactivation, to a more unfolded form which is not able to refold "incorrectly". The stability of alpha-chymotrypsin is regulated within a wide range by medium alteration: the stabilizing effects are similar to those achieved by multipoint attachment of the enzyme to a support or by hydrophilization of protein by covalent modification.

Compression of facsimile graphics for transmission over digital mobile satellite circuits

NASA Astrophysics Data System (ADS)

Dimolitsas, Spiros; Corcoran, Frank L.

A technique for reducing the transmission requirements of facsimile images while maintaining high intelligibility in mobile communications environments is described. The algorithms developed are capable of achieving a compression of approximately 32 to 1. The technique focuses on the implementation of a low-cost interface unit suitable for facsimile communication between low-power mobile stations and fixed stations for both point-to-point and point-to-multipoint transmissions. This interface may be colocated with the transmitting facsimile terminals. The technique was implemented and tested by intercepting facsimile documents in a store-and-forward mode.

Analysis of the Temporal Response of Coupled Asymmetrical Zero-Power Subcritical Bare Metal Reactor Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klain, Kimberly L.

The behavior of symmetrical coupled-core systems has been extensively studied, yet there is a dearth of research on asymmetrical systems due to the increased complexity of the analysis of such systems. In this research, the multipoint kinetics method is applied to asymmetrical zeropower, subcritical, bare metal reactor systems. Existing research on asymmetrical reactor systems assumes symmetry in the neutronic coupling; however, it will be shown that this cannot always be assumed. Deep subcriticality adds another layer of complexity and requires modification of the multipoint kinetics equations to account for the effect of the external neutron source. A modified set ofmore » multipoint kinetics equations is derived with this in mind. Subsequently, the Rossi-alpha equations are derived for a two-region asymmetrical reactor system. The predictive capabilities of the radiation transport code MCNP6 for neutron noise experiments are shown in a comparison to the results of a series of Rossi-alpha measurements performed by J. Mihalczo utilizing a coupled set of symmetrical bare highly-enriched uranium (HEU) cylinders. The ptrac option within MCNP6 can generate time-tagged counts in a cell (list-mode data). The list-mode data can then be processed similarly to measured data to obtain values for system parameters such as the dual prompt neutron decay constants observable in a coupled system. The results from the ptrac simulations agree well with the historical measured values. A series of case studies are conducted to study the effects of geometrical asymmetry in the coupling between two bare metal HEU cylinders. While the coupling behavior of symmetrical systems has been reported on extensively, that of asymmetrical systems remains sparse. In particular, it appears that there has been no previous research in obtaining the coupling time constants for asymmetrically-coupled systems. The difficulty in observing such systems is due in part to the inability to determine the individual coupling coefficients from measurement: unlike the symmetrical cases, only the product of the values can be obtained. A method is proposed utilizing MCNP6 tally ratios to separate the coupling coefficients for such systems. This work provides insight into the behavior of asymmetrically-coupled systems as the separation distance between the two cores is changed and also as the asymmetry is increased. As the asymmetry increases, both the slower and the faster observable prompt neutron decay constants increase in magnitude. The coupling time constants are determined from the measured decay constants. As the separation distance increases, both coupling coefficients decrease as expected. Based on these findings, an effective computational method utilizing MCNP6 and the Rossialpha technique can be applied to the prediction of asymmetrical coupled system measurements.« less

Caracterisation et modelisation de la degradation des proprietes fonctionnelles des AMF soumis a un chargement cyclique

NASA Astrophysics Data System (ADS)

Paradis, Alexandre

The principal objective of the present thesis is to elaborate a computational model describing the mechanical properties of NiTi under different loading conditions. Secondary objectives are to build an experimental database of NiTi under stress, strain and temperature in order to validate the versatility of the new model proposed herewith. The simulation model used presently at Laboratoire sur les Alliage a Memoire et les Systemes Intelligents (LAMSI) of ETS is showing good behaviour in quasi-static loading. However, dynamic loading with the same model do not allows one to include degradation. The goal of the present thesis is to build a model capable of describing such degradation in a relatively accurate manner. Some experimental testing and results will be presented. In particular, new results on the behaviour of NiTi being paused during cycling are presented in chapter 2. A model is developed in chapter 3 based on Likhachev's micromechanical model. Good agreement is found with experimental data. Finally, an adaptation of the model is presented in chapter 4, allowing it to be eventually implemented into a finite-element commercial software.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abbas, Syed Haider; Lee, Jung-Ryul; Jang, Jae-Kyeong

Pyroshock can cause failure to the objective of an aerospace structure by damaging its sensitive electronic equipment, which is responsible for performing decisive operations. A pyroshock is the high intensity shock wave that is generated when a pyrotechnic device is explosively triggered to separate, release, or activate structural subsystems of an aerospace architecture. Pyroshock measurement plays an important role in experimental simulations to understand the characteristics of pyroshock on the host structure. This paper presents a technology to measure a pyroshock wave at multiple points using laser Doppler vibrometers (LDVs). These LDVs detect the pyroshock wave generated due to anmore » explosive-based pyrotechnical event. Field programmable gate array (FPGA) based data acquisition is used in the study to acquire pyroshock signals simultaneously from multiple channels. This paper describes the complete system design for multipoint pyroshock measurement. The firmware architecture for the implementation of multichannel data acquisition on an FPGA-based development board is also discussed. An experiment using explosive bolts was configured to test the reliability of the system. Pyroshock was generated using explosive excitation on a 22-mm-thick steel plate. Three LDVs were deployed to capture the pyroshock wave at different points. The pyroshocks captured were displayed as acceleration plots. The results showed that our system effectively captured the pyroshock wave with a peak-to-peak magnitude of 303 741 g. The contribution of this paper is a specialized architecture of firmware design programmed in FPGA for data acquisition of large amount of multichannel pyroshock data. The advantages of the developed system are the near-field, multipoint, non-contact, and remote measurement of a pyroshock wave, which is dangerous and expensive to produce in aerospace pyrotechnic tests.« less

Solar and Space Physics Science Enabled by Pico and Nano Satellites

NASA Astrophysics Data System (ADS)

Swenson, C.; Fish, C. S.

2012-12-01

The most significant advances in solar and space physics, or Heliophysics, over the next decade are most likely to derive from new observational techniques. The connection between advances in scientific understanding and technology has historically been demonstrated across many disciplines and time. Progress on some of the most compelling scientific problems will most likely occur through multipoint observations within the space environment to understand the coupling between disparate regions: Heliosphere, magnetosphere, ionosphere, thermosphere and mesosphere. Multipoint measurements are also needed to develop understanding of the various scalars or vector field signatures (i.e gradients, divergence) that arise from coupling processes that occur across temporal and spatial scales or within localized regions. The resources that are available over the next decades for all areas of Heliophysics research have limits and it is therefore important that the community be innovative in developing new observational techniques to advance science. One of the most promising new observational techniques becoming available are miniaturized sensors and satellite systems called pico- or nano-satellites and CubeSats. These are enabled by the enormous investment of the commercial, medical, and defense industries in producing highly capable, portable and low-power battery-operated consumer electronics, in-situ composition probes, and novel reconnaissance sensors. The advancements represented by these technologies have direct application in developing pico- or nano-satellites and CubeSats system for Heliophysics research. In this talk we overview the current environment and technologies surrounding these novel small satellites and discuss the types and capabilities of the miniature sensors that are being developed. We discuss how pico- or nano-satellites and CubeSats can be used to address highest priority science identified in the Decadal Survey and the innovations and advancements that are required to make substantial progress.

An in-vitro animal experiment on metal implants’ thermal effect on radiofrequency ablation

PubMed Central

2013-01-01

Background To explore metal implants’ thermal effect on radiofrequency ablation (RFA) and ascertain distance-thermal relationship between the metal implants and radiofrequency (RF) electrode. Methods Metal implants models were established in seven in-vitro porcine livers using silver clips or 125I seeds. RFA were conducted centering the RF electrode axis1 cm away from them, with one side containing a metal implants model the test group and the other side the control group. The thermometric needles were used to measure multi-point temperatures in order to compare the time-distance-temperature difference between the two groups. The gross scopes of the ablation of the two groups were measured and the tissues were analyzed for microscopic histology. Results At the ablation times of 8, 12, and 15 min, the average multi-point temperatures of the test group and the control group were 48.2±18.07°C, 51.5±19.57°C, 54.6±19.75°C, and 48.6±17.69°C, 52.2±19.73°C, 54.9±19.24°C, respectively, and the differences were not statistically significant (n=126, P>0.05). At the ablation times of 12 and 15 min, the ablation scopes of the test group and the control group were (horizontal/longitudinal diameter) 1.55/3.48 cm, 1.89/3.72 cm, and 1.56/3.48 cm, 1.89/3.72 cm, respectively, and the differences were not statistically significant (n=14, P>0.05). The two groups had the same manifestations in microscopy. Conclusions Metal implants do not cause significant thermal effect on RFA. PMID:23799942

Multipoint Pacing versus conventional ICD in Patients with a Narrow QRS complex (MPP Narrow QRS trial): study protocol for a pilot randomized controlled trial.

PubMed

Gasparini, Maurizio; Galimberti, Paola; Bragato, Renato; Ghio, Stefano; Raineri, Claudia; Landolina, Maurizio; Chieffo, Enrico; Lunati, Maurizio; Mulargia, Ederina; Proclemer, Alessandro; Facchin, Domenico; Rordorf, Roberto; Vicentini, Alessandro; Marcantoni, Lina; Zanon, Francesco; Klersy, Catherine

2016-12-03

Despite an intensive search for predictors of the response to cardiac resynchronization therapy (CRT), the QRS duration remains the simplest and most robust predictor of a positive response. QRS duration of ≥ 130 ms is considered to be a prerequisite for CRT; however, some studies have shown that CRT may also be effective in heart failure (HF) patients with a narrow QRS (<130 ms). Since CRT can now be performed by pacing the left ventricle from multiple vectors via a single quadripolar lead, it is possible that multipoint pacing (MPP) might be effective in HF patients with a narrow QRS. This article reports the design of the MPP Narrow QRS trial, a prospective, randomized, multicenter, controlled feasibility study to investigate the efficacy of MPP using two LV pacing vectors in patients with a narrow QRS complex (100-130 ms). Fifty patients with a standard ICD indication will be enrolled and randomized (1:1) to either an MPP group or a Standard ICD group. All patients will undergo a low-dose dobutamine stress echo test and only those with contractile reserve will be included in the study and randomized. The primary endpoint will be the percentage of patients in each group that have reverse remodeling at 12 months, defined as a reduction in left ventricular end-systolic volume (LVESV) of >15% from the baseline. This feasibility study will determine whether MPP improves reverse remodeling, as compared with standard ICD, in HF patients who have a narrow QRS complex (100-130 ms). ClinicalTrials.gov, NCT02402816 . Registered on 25 March 2015.

Development of an FBG-based low temperature measurement system for cargo containment of LNG tankers

NASA Astrophysics Data System (ADS)

Kim, D. G.; Yoo, W.; Swinehart, P.; Jiang, B.; Haber, T.; Mendez, A.

2007-09-01

Given the growing demand for oil and natural gas to meet the world's energy needs, there is nowadays renewed interest in the use of liquefied natural gas (LNG) systems. For LNG to remain in its liquid phase, the gas has to be kept at cryogenic temperatures (< 160°C). And, as part of the LNG supply process, it becomes necessary to transport it using massive carrier tankers with cargo hulls operating at low temperatures and using special insulating double-wall construction. The safe and reliable storage and transportation of LNG products calls for low temperature monitoring of said containers to detect the onset of any potential leaks and possible thermal insulation degradation. Because of the hazardous nature of this cargo, only intrinsically-safe, explosion proof devices can be used. Optical fiber sensors-- such as fiber Bragg gratings-- are ideal for this application given their dielectric nature and multi-point sensing telemetry capability. In this paper, we describe the development of an on-line, multi-point FBG-based low temperature monitoring system based on a network of specially packaged FBG temperature and strain sensors mounted at critical locations within the inner hull, cofferdam and secondary barriers of a LNG carrier tanker. Given the stringent cryogenic operating temperature conditions, pertinent FBG designs, coatings and packaging approaches were formulated along with adequate installation techniques and integration of the interrogating FBG electronics into the tanker's overall SCADA monitoring system. FBG temperature sensors were demonstrated to be stable and sensitive over the 80-480K range. Stability is +/- 0.25K or better with repeated calibrations, and long term stability at 480K is ~0.2mK/hour.

Solar Cycle Variation and Multipoint Studies of ICME Properties

NASA Technical Reports Server (NTRS)

Russell, C. T.

2005-01-01

The goal of the Living With a Star program is to understand the Sun-Earth connection sufficiently well that we can solve problems critical to life and society. This can most effectively be done in the short term using observations from our past and on-going programs. Not only can this approach solve some of the pressing issues but also it can provide ideas for the deployment of future spacecraft in the LWS program. The proposed effort uses data from NEAR, SOHO, Wind, ACE and Pioneer Venus in quadrature, multipoint, and solar cycle studies to study the interplanetary coronal mass ejection and its role in the magnetic flux cycle of the Sun. ICMEs are most important to the LWS objectives because the solar wind conditions associated with these structures are the most geoeffective of any solar wind phenomena. Their ability to produce strong geomagnetic disturbances arises first because of their high speed. This high speed overtakes the ambient solar wind producing a bow shock wave similar to the terrestrial bow shock. In the new techniques we develop as part of this effort we exploit this feature of ICMEs. This shocked plasma has a greater velocity, higher density and stronger magnetic field than the ambient solar wind, conditions that can enhance geomagnetic activity. The driving ICME is a large magnetic structure expanding outward in the solar wind [Gosling, 19961. The ICMEs magnetic field is generally much higher than that in the ambient solar wind and the velocity is high. The twisted nature of the magnetic field in an ICME almost ensures that sometime during the ICME conditions favorable for geomagnetic storm initiation will occur.

Chorus Whistler Wave Source Scales As Determined From Multipoint Van Allen Probe Measurements

NASA Technical Reports Server (NTRS)

Agapitov, O.; Blum, L. W.; Mozer, F. S.; Bonnell, J. W.; Wygant, J.

2017-01-01

Whistler mode chorus waves are particularly important in outer radiation belt dynamics due to their key role in controlling the acceleration and scattering of electrons over a very wide energy range. The key parameters for both nonlinear and quasi-linear treatment of wave-particle interactions are the temporal and spatial scales of the wave source region and coherence of the wave field perturbations. Neither the source scale nor the coherence scale is well established experimentally, mostly because of a lack of multipoint VLF waveform measurements. We present an unprecedentedly long interval of coordinated VLF waveform measurements (sampled at 16384 s(exp -1)) aboard the two Van Allen Probes spacecraft-9 h (0800-1200 UT and 1700-2200 UT) during two consecutive apogees on 15 July 2014. The spacecraft separations varied from about 100 to 5000 km (mostly radially); measurements covered an L shell range from 3 to 6; magnetic local time 0430-0900, and magnetic latitudes were approximately 15 and approximately 5 deg during the two orbits. Using time-domain correlation techniques, the single chorus source spatial extent transverse to the background magnetic field has been determined to be about 550-650 km for upper band chorus waves with amplitudes less than 100 pT and up to 800 km for larger amplitude, lower band chorus waves. The ratio between wave amplitudes measured on the two spacecraft is also examined to reveal that the wave amplitude distribution within a single chorus element generation area can be well approximated by a Gaussian exp(-0.5 x r (exp 2)/r(sub 0)(exp 2)), with the characteristic scale r(sub 0) around 300 km. Waves detected by the two spacecraft were found to be coherent in phase at distances up to 400 km.

A Novel Multi-Aperture Based Sun Sensor Based on a Fast Multi-Point MEANSHIFT (FMMS) Algorithm

PubMed Central

You, Zheng; Sun, Jian; Xing, Fei; Zhang, Gao-Fei

2011-01-01

With the current increased widespread interest in the development and applications of micro/nanosatellites, it was found that we needed to design a small high accuracy satellite attitude determination system, because the star trackers widely used in large satellites are large and heavy, and therefore not suitable for installation on micro/nanosatellites. A Sun sensor + magnetometer is proven to be a better alternative, but the conventional sun sensor has low accuracy, and cannot meet the requirements of the attitude determination systems of micro/nanosatellites, so the development of a small high accuracy sun sensor with high reliability is very significant. This paper presents a multi-aperture based sun sensor, which is composed of a micro-electro-mechanical system (MEMS) mask with 36 apertures and an active pixels sensor (APS) CMOS placed below the mask at a certain distance. A novel fast multi-point MEANSHIFT (FMMS) algorithm is proposed to improve the accuracy and reliability, the two key performance features, of an APS sun sensor. When the sunlight illuminates the sensor, a sun spot array image is formed on the APS detector. Then the sun angles can be derived by analyzing the aperture image location on the detector via the FMMS algorithm. With this system, the centroid accuracy of the sun image can reach 0.01 pixels, without increasing the weight and power consumption, even when some missing apertures and bad pixels appear on the detector due to aging of the devices and operation in a harsh space environment, while the pointing accuracy of the single-aperture sun sensor using the conventional correlation algorithm is only 0.05 pixels. PMID:22163770

Local multipoint distribution system (LDMS) versus free-space optical (FSO) networks

NASA Astrophysics Data System (ADS)

Willebrand, Heinz A.; Clark, Gerald R.; Willson, Bryan; Andreu von Euw, Christian G.; Roy, Joe; Mayhew, Laurel M.

2001-11-01

This paper compares two emerging broadband access methodologies, Free Space Optics (FSO) and Local Multipoint Distribution System (LMDS) and the atmospheric propagation characteristics of each when exposed to a dynamically changing channel. The comparison focuses on bandwidth, availability, and distance requirements for the new broadband market and how LMDS and FSO can be used to meet these requirements. Possible network topologies and their associated costs are examined. This comparison takes into account the total cost of deployment, including equipment costs, installation fees, access fees, and spectrum licensing fees. LMDS and FSO are compared on speed of deployment, scalability, aggregate bandwidth, and bandwidth per customer. Present and projected capabilities of each technology are considered for their suitability in different locations in the network, from the Wide Area Network (WAN), to the Metropolitan Area Network (MAN), all the way to Last Mile Access. There is a discussion on the relative performance of LMDS and FSO, focusing on the different factors that can affect link availability. Since network design is a large factor in assuring overall reliability, the flexibility of each technology with regard to network design is compared. LMDS and FSO are both line of sight, space-propagated technologies, and as such, they are both susceptible to path impediments and atmospheric attenuation, dispersion, scattering, and absorption. LMDS and FSO are affected very differently by different meteorological phenomena. Problematic atmospheric conditions are, specifically scintillation, rainfall, and fog, are examined. In addition to a discussion of these conditions, various techniques for minimizing atmospheric and environmental effects are investigated. The paper concludes with a summary of findings and recommendations for a number of broadband wireless applications.

Significant linkage to airway responsiveness on chromosome 12q24 in families of children with asthma in Costa Rica.

PubMed

Celedón, Juan C; Soto-Quiros, Manuel E; Avila, Lydiana; Lake, Stephen L; Liang, Catherine; Fournier, Eduardo; Spesny, Mitzi; Hersh, Craig P; Sylvia, Jody S; Hudson, Thomas J; Verner, Andrei; Klanderman, Barbara J; Freimer, Nelson B; Silverman, Edwin K; Weiss, Scott T

2007-01-01

Although asthma is a major public health problem in certain Hispanic subgroups in the United States and Latin America, only one genome scan for asthma has included Hispanic individuals. Because of small sample size, that study had limited statistical power to detect linkage to asthma and its intermediate phenotypes in Hispanic participants. To identify genomic regions that contain susceptibility genes for asthma and airway responsiveness in an isolated Hispanic population living in the Central Valley of Costa Rica, we conducted a genome-wide linkage analysis of asthma (n = 638) and airway responsiveness (n = 488) in members of eight large pedigrees of Costa Rican children with asthma. Nonparametric multipoint linkage analysis of asthma was conducted by the NPL-PAIR allele-sharing statistic, and variance component models were used for the multipoint linkage analysis of airway responsiveness as a quantitative phenotype. All linkage analyses were repeated after exclusion of the phenotypic data of former and current smokers. Chromosome 12q showed some evidence of linkage to asthma, particularly in nonsmokers (P < 0.01). Among nonsmokers, there was suggestive evidence of linkage to airway responsiveness on chromosome 12q24.31 (LOD = 2.33 at 146 cM). After genotyping 18 additional short-tandem repeat markers on chromosome 12q, there was significant evidence of linkage to airway responsiveness on chromosome 12q24.31 (LOD = 3.79 at 144 cM), with a relatively narrow 1.5-LOD unit support interval for the observed linkage peak (142-147 cM). Our results suggest that chromosome 12q24.31 contains a locus (or loci) that influence a critical intermediate phenotype of asthma (airway responsiveness) in Costa Ricans.

Exome sequencing and genome-wide linkage analysis in 17 families illustrate the complex contribution of TTN truncating variants to dilated cardiomyopathy.

PubMed

Norton, Nadine; Li, Duanxiang; Rampersaud, Evadnie; Morales, Ana; Martin, Eden R; Zuchner, Stephan; Guo, Shengru; Gonzalez, Michael; Hedges, Dale J; Robertson, Peggy D; Krumm, Niklas; Nickerson, Deborah A; Hershberger, Ray E

2013-04-01

BACKGROUND- Familial dilated cardiomyopathy (DCM) is a genetically heterogeneous disease with >30 known genes. TTN truncating variants were recently implicated in a candidate gene study to cause 25% of familial and 18% of sporadic DCM cases. METHODS AND RESULTS- We used an unbiased genome-wide approach using both linkage analysis and variant filtering across the exome sequences of 48 individuals affected with DCM from 17 families to identify genetic cause. Linkage analysis ranked the TTN region as falling under the second highest genome-wide multipoint linkage peak, multipoint logarithm of odds, 1.59. We identified 6 TTN truncating variants carried by individuals affected with DCM in 7 of 17 DCM families (logarithm of odds, 2.99); 2 of these 7 families also had novel missense variants that segregated with disease. Two additional novel truncating TTN variants did not segregate with DCM. Nucleotide diversity at the TTN locus, including missense variants, was comparable with 5 other known DCM genes. The average number of missense variants in the exome sequences from the DCM cases or the ≈5400 cases from the Exome Sequencing Project was ≈23 per individual. The average number of TTN truncating variants in the Exome Sequencing Project was 0.014 per individual. We also identified a region (chr9q21.11-q22.31) with no known DCM genes with a maximum heterogeneity logarithm of odds score of 1.74. CONCLUSIONS- These data suggest that TTN truncating variants contribute to DCM cause. However, the lack of segregation of all identified TTN truncating variants illustrates the challenge of determining variant pathogenicity even with full exome sequencing.

Space Technology 5 Observations of Auroral Field-Aligned Currents

NASA Technical Reports Server (NTRS)

Slavin, James

2008-01-01

During its three month long technology validation mission, Space Technology 5 (ST-5) returned high quality multi-point measurements of the near-Earth magnetic field. Its three micro-satellites were launched into a 300 x 4500 km, dawn - dusk, sun synchronous orbit (inclination = 105.60) orbit with a period of 138 min by a Pegasus launch vehicle on March 22, 2006. The spacecraft were maintained in a "pearls on a sting" constellation with controlled spacings ranging from just over 5000 km down to under 50 km. The individual micro-satellites were 48 cm tall octagons with diameters of 50 cm. They were spin-stabilized at approximately 20 rpm at deployment and slowly spun-down to about 15 rpm by the end of the mission. Each spacecraft carried a miniature tri-axial fluxgate magnetometer (MAG) provided by the University of California at Los Angeles mounted at the end of a ultra-low mass 72 cm boom. These data allow, for the first time, the separation of temporal and spatial variations in field-aligned current (FAC) perturbations measured in low-Earth orbit on time scales of 10 sec to 10 min. The constellation measurements are used to directly determine field-aligned current sheet motion, thickness. and current density. Two multi-point methods for the inference of FAC current density that have not previously been possible in low-Earth orbit are demonstrated: 1) the -standard method." based upon s/c velocity, but corrected for FAC current sheet motion. and 2) the "gradiometer method" which uses simultaneous magnetic field measurements at two points with known separation. Future studies will apply these methods to the entire ST-5 data sct and expand to include horizontal ionospheric currents. ULF waves and geomagnetic field gradient analyses.

Evidence for a gene influencing the TG/HDL-C ratio on chromosome 7q32.3-qter: a genome-wide scan in the Framingham study.

PubMed

Shearman, A M; Ordovas, J M; Cupples, L A; Schaefer, E J; Harmon, M D; Shao, Y; Keen, J D; DeStefano, A L; Joost, O; Wilson, P W; Housman, D E; Myers, R H

2000-05-22

Some studies show that plasma triglyceride (TG) levels are a significant independent risk factor for cardiovascular disease (CVD). TG levels are inversely correlated with high density lipoprotein cholesterol (HDL-C) levels, and their metabolism may be closely interrelated. Therefore, the TG/HDL-C ratio may be a relevant CVD risk factor. Our analysis of families in the Framingham Heart Study gave a genetic heritability estimate for log(TG) of 0.40 and for log(TG/HDL-C) of 0.49, demonstrating an important genetic component for both. A 10 cM genome-wide scan for log(TG) level and log(TG/HDL-C) was carried out for the largest 332 extended families of the Framingham Heart Study (1702 genotyped individuals). The highest multipoint variance component LOD scores obtained for both log(TG) and log(TG/HDL-C) were on chromosome 7 (at 155 cM), where the results for the two phenotypes were 1.8 and 2.5, respectively. The 7q32.3-qter region contains several candidate genes. Four other regions with multipoint LOD scores greater than one were identified on chromosome 3 [LOD score for log(TG/HDL-C) = 1.8 at 140 cM], chromosome 11 [LOD score for log(TG/HDL-C) = 1.1 at 125 cM], chromosome 16 [LOD score for log(TG) = 1.5 at 70 cM, LOD score for log(TG/HDL-C) = 1.1 at 75 cM] and chromosome 20 [LOD score for log(TG/HDL-C) = 1.7 at 35 cM, LOD score for log(TG) = 1.3 at 40 cM]. These results identify loci worthy of further study.

Localization of a gene (CMT2A) for autosomal dominant Charcot-Marie-Tooth disease type 2 to chromosome 1p and evidence of genetic heterogeneity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Othmane, K.B.; Loprest, L.J.; Wilkinson, K.M.

1993-08-01

Charcot-Marie-Tooth (CMT) disease type 2 (CMT2) is an inherited peripheral neuropathy characterized by variable age of onset and normal or slightly diminished nerve conduction velocity. CMT2 is pathologically and genetically distinct from CMT type 1 (CMT1). While CMT1 has been shown to be genetically heterogeneous, no chromosomal localization has been established for CMT2. The authors have performed pedigree linkage analysis in six large autosomal dominant CMT2 families and have demonstrated linkage and heterogeneity to a series of microsatellites (D1S160, D1S170, D1S244, D1S228 and D1S199) in the distal region of the short arm of chromosome 1. Significant evidence for heterogeneity wasmore » found using admixture analyses and the two-point lod scores. Admixture analyses using the multipoint results for the markers D1S244, D1S228, and D1S199 supported the two-point findings. Three families, DUK662, DUK1241, and 1523 gave posterior probabilities of 1.0, 0.98, and 0.88 of being of the linked type. Multipoint analysis examining the [open quotes]linked[close quotes] families showed that the most favored location for the CMT2A gene is within the interval flanked by D1S244 and D1S228 (odds approximately 70:1 of lying within versus outside that interval). These findings suggest that the CMT2 phenotype is secondary to at least two different genes and demonstrate further heterogeneity in the CMT phenotype.« less

Multipoint Optimal Minimum Entropy Deconvolution and Convolution Fix: Application to vibration fault detection

NASA Astrophysics Data System (ADS)

McDonald, Geoff L.; Zhao, Qing

2017-01-01

Minimum Entropy Deconvolution (MED) has been applied successfully to rotating machine fault detection from vibration data, however this method has limitations. A convolution adjustment to the MED definition and solution is proposed in this paper to address the discontinuity at the start of the signal - in some cases causing spurious impulses to be erroneously deconvolved. A problem with the MED solution is that it is an iterative selection process, and will not necessarily design an optimal filter for the posed problem. Additionally, the problem goal in MED prefers to deconvolve a single-impulse, while in rotating machine faults we expect one impulse-like vibration source per rotational period of the faulty element. Maximum Correlated Kurtosis Deconvolution was proposed to address some of these problems, and although it solves the target goal of multiple periodic impulses, it is still an iterative non-optimal solution to the posed problem and only solves for a limited set of impulses in a row. Ideally, the problem goal should target an impulse train as the output goal, and should directly solve for the optimal filter in a non-iterative manner. To meet these goals, we propose a non-iterative deconvolution approach called Multipoint Optimal Minimum Entropy Deconvolution Adjusted (MOMEDA). MOMEDA proposes a deconvolution problem with an infinite impulse train as the goal and the optimal filter solution can be solved for directly. From experimental data on a gearbox with and without a gear tooth chip, we show that MOMEDA and its deconvolution spectrums according to the period between the impulses can be used to detect faults and study the health of rotating machine elements effectively.

Genomewide Linkage Scan for Split–Hand/Foot Malformation with Long-Bone Deficiency in a Large Arab Family Identifies Two Novel Susceptibility Loci on Chromosomes 1q42.2-q43 and 6q14.1

PubMed Central

Naveed, Mohammed; Nath, Swapan K.; Gaines, Mathew; Al-Ali, Mahmoud T.; Al-Khaja, Najib; Hutchings, David; Golla, Jeffrey; Deutsch, Samuel; Bottani, Armand; Antonarakis, Stylianos E.; Ratnamala, Uppala; Radhakrishna, Uppala

2007-01-01

Split–hand/foot malformation with long-bone deficiency (SHFLD) is a rare, severe limb deformity characterized by tibia aplasia with or without split-hand/split-foot deformity. Identification of genetic susceptibility loci for SHFLD has been unsuccessful because of its rare incidence, variable phenotypic expression and associated anomalies, and uncertain inheritance pattern. SHFLD is usually inherited as an autosomal dominant trait with reduced penetrance, although recessive inheritance has also been postulated. We conducted a genomewide linkage analysis, using a 10K SNP array in a large consanguineous family (UR078) from the United Arab Emirates (UAE) who had disease transmission consistent with an autosomal dominant inheritance pattern. The study identified two novel SHFLD susceptibility loci at 1q42.2-q43 (nonparametric linkage [NPL] 9.8, P=.000065) and 6q14.1 (NPL 7.12, P=.000897). These results were also supported by multipoint parametric linkage analysis. Maximum multipoint LOD scores of 3.20 and 3.78 were detected for genomic locations 1q42.2-43 and 6q14.1, respectively, with the use of an autosomal dominant mode of inheritance with reduced penetrance. Haplotype analysis with informative crossovers enabled mapping of the SHFLD loci to a region of ∼18.38 cM (8.4 Mb) between single-nucleotide polymorphisms rs1124110 and rs535043 on 1q42.2-q43 and to a region of ∼1.96 cM (4.1 Mb) between rs623155 and rs1547251 on 6q14.1. The study identified two novel loci for the SHFLD phenotype in this UAE family. PMID:17160898

Genome-wide linkage scan for submaximal exercise heart rate in the HERITAGE family study.

PubMed

Spielmann, Nadine; Leon, Arthur S; Rao, D C; Rice, Treva; Skinner, James S; Rankinen, Tuomo; Bouchard, Claude

2007-12-01

The purpose of this study was to identify regions of the human genome linked to submaximal exercise heart rates in the sedentary state and in response to a standardized 20-wk endurance training program in blacks and whites of the HERITAGE Family Study. A total of 701 polymorphic markers covering the 22 autosomes were used in the genome-wide linkage scan, with 328 sibling pairs from 99 white nuclear families and 102 pairs from 115 black family units. Steady-state heart rates were measured at the relative intensity of 60% maximal oxygen uptake (HR60) and at the absolute intensity of 50 W (HR50). Baseline phenotypes were adjusted for age, sex, and baseline body mass index (BMI) and training responses (posttraining minus baseline, Delta) were adjusted for age, sex, baseline BMI, and baseline value of the phenotype. Two analytic strategies were used, a multipoint variance components and a regression-based multipoint linkage analysis. In whites, promising linkages (LOD > 1.75) were identified on 18q21-q22 for baseline HR50 (LOD = 2.64; P = 0.0002) and DeltaHR60 (LOD = 2.10; P = 0.0009) and on chromosome 2q33.3 for DeltaHR50 (LOD = 2.13; P = 0.0009). In blacks, evidence of promising linkage for baseline HR50 was detected with several markers within the chromosomal region 10q24-q25.3 (peak LOD = 2.43, P = 0.0004 with D10S597). The most promising regions for fine mapping in the HERITAGE Family Study were found on 2q33 for HR50 training response in whites, on 10q25-26 for baseline HR60 in blacks, and on 18q21-22 for both baseline HR50 and DeltaHR60 in whites.

Multi-point Shock and Flux Rope Analysis of Multiple Interplanetary Coronal Mass Ejections around 2010 August 1 in the Inner Heliosphere

NASA Astrophysics Data System (ADS)

Möstl, C.; Farrugia, C. J.; Kilpua, E. K. J.; Jian, L. K.; Liu, Y.; Eastwood, J. P.; Harrison, R. A.; Webb, D. F.; Temmer, M.; Odstrcil, D.; Davies, J. A.; Rollett, T.; Luhmann, J. G.; Nitta, N.; Mulligan, T.; Jensen, E. A.; Forsyth, R.; Lavraud, B.; de Koning, C. A.; Veronig, A. M.; Galvin, A. B.; Zhang, T. L.; Anderson, B. J.

2012-10-01

We present multi-point in situ observations of a complex sequence of coronal mass ejections (CMEs) which may serve as a benchmark event for numerical and empirical space weather prediction models. On 2010 August 1, instruments on various space missions, Solar Dynamics Observatory/Solar and Heliospheric Observatory/Solar-TErrestrial-RElations-Observatory (SDO/SOHO/STEREO), monitored several CMEs originating within tens of degrees from the solar disk center. We compare their imprints on four widely separated locations, spanning 120° in heliospheric longitude, with radial distances from the Sun ranging from MESSENGER (0.38 AU) to Venus Express (VEX, at 0.72 AU) to Wind, ACE, and ARTEMIS near Earth and STEREO-B close to 1 AU. Calculating shock and flux rope parameters at each location points to a non-spherical shape of the shock, and shows the global configuration of the interplanetary coronal mass ejections (ICMEs), which have interacted, but do not seem to have merged. VEX and STEREO-B observed similar magnetic flux ropes (MFRs), in contrast to structures at Wind. The geomagnetic storm was intense, reaching two minima in the Dst index (≈ - 100 nT), and was caused by the sheath region behind the shock and one of two observed MFRs. MESSENGER received a glancing blow of the ICMEs, and the events missed STEREO-A entirely. The observations demonstrate how sympathetic solar eruptions may immerse at least 1/3 of the heliosphere in the ecliptic with their distinct plasma and magnetic field signatures. We also emphasize the difficulties in linking the local views derived from single-spacecraft observations to a consistent global picture, pointing to possible alterations from the classical picture of ICMEs.

[PEG-chitosan branched copolymers to improve the biocatalytic properties of Erwinia carotovora recombinant L-asparaginase].

PubMed

Kudryashova, E V; Suhoverkov, K V; Sokolov, N N

2015-01-01

A new approach to the regulation of catalytic properties of medically relevant enzymes has been proposed using the novel recombinant preparation of L-asparaginase from Erwinia carotovora (EwA), a promising antitumor agent. New branched co-polymers of different composition based on chitosan modified with polyethylene glycol (PEG) molecules, designated as PEG-chitosan, have been synthesized. PEG-chitosan copolymers were further conjugated with EwA. In order to optimize the catalytic properties of asparaginase two types of conjugates differing in their architecture have been synthesized: (1) crown-type conjugates were synthesized by reductive amination reaction between the reducing end of the PEG-chitosan copolymer and enzyme amino groups; (2) multipoint-conjugates were synthesized using the reaction of multipoint amide bond formation between PEG-chitosan amino groups and carboxyl groups of the enzyme in the presence of the Woodward's reagent. The structure and composition of these conjugates were determined by IR spectroscopy. The content of the copolymers in the conjugates was controlled by the characteristic absorption band of C-O-C bonds in the PEG structure at the frequency of 1089 cm-1. The study of catalytic characteristics of EwA preparations by conductometry showed that at physiological pH values the enzyme conjugates with PEG-chitosan with optimized structure and the optimal composition demonstrated 5-8-fold higher catalytic efficiency (kcat/Km) than the native enzyme. To certain extent, this can be attributed to favorable shift of pH-optima in result of positively charged amino-groups introduction in the vicinity of the active site. The proposed approach, chito-pegylation, is effective for regulating the catalytic and pharmacokinetic properties of asparaginase, and is promising for the development of prolonged action dosage forms for other enzyme therapeutics.

[Clinical efficacy and safety of uterine artery chemoembolization in abnormal placental implantation complicated with postpartum hemorrhage].

PubMed

Chen, Yao-ting; Xu, Lin-feng; Sun, Hong-liang; Li, Hui-qing; Hu, Ren-mei; Tan, Qi-yin

2010-04-01

To investigate the safety and clinical efficacy of uterime artery chemoembolization in postpartum hemorrhage (PPH) caused by abnormal placental implantation. Between December 2006 and September 2009, there were 23 cases of abnormal placental implantation with PPH in our hospital, among which 9 presented with continuous small amount of vaginal bleeding and 14 with acute excessive bleeding. The average bleeding time was (8+/-6) d and the mean blood loss was (980+/-660) ml. Abnormal placental implantation was confirmed by color Doppler ultrasound (CD-US) in all cases, the internal iliac artery angiography was performed to identify the uterine artery and bilateral uterine artery chemoembolization (UACE) with methotrexate (MTX) and gelfoam particles to the distal end of uterine artery was conducted after. CD-US rechecked all patients within 48 h after UACE and those patients with blurred margins between placenta and uterus and abnormal blood flow (>1 cmx1 cm) received ultrasonic-guided per vagina MTX multipoint injections. All cases were followed up for 3-26 months (average 12 months) to observe vaginal bleeding, placenta tissue discharge, serum human chorionic gonadotropin (hCG), uterine involution, menses, and side-effects or complications. (1) Curative effect: These 23 cases underwent 24 procedures of UACE successfully and vaginal bleeding ceased at an average of (3.5+/-1.3) min after UACE. Reduced blood flow in the placental implantation area was detected under CD-US after UACE. Among the 23 patients, wterine curettage was required in 16 cases due to retained placenta tissues with the mean blood loss of (40+/-28) ml during the operation, 2 underwent subtotal hysterectomy and confirmed to be placenta percreta by pathology examination, and placenta tissues were spontaneously discharged completely in 5 cases. Totally, 91% of the patients (21/23) reserved their uterus. (2) FOLLOW-UP: the serum hCG reduced to normal within 1-13 d after the placenta tissue were evacuated. Regular menstruation returned within 2-3 months in those patients who reserved uterus and normal size uterus was found under sonography at 3 months. No severe complication was reported except for some post embolization syndrome, such as pelvic pain or fever. UACE, combined with ultrasonic-guided transvaginal MTX injection, is a safe, minimal invasive and quick hemostatic procedure in treatment of abnormal placental implantation with PPH, and allows the preservation of uterus possible. CD-US is helpful in evaluation of the blood flow changes before and after UACE in abnormal placental implantation patients.

Modelisation de la diffusion sur les surfaces metalliques: De l'adatome aux processus de croissance

NASA Astrophysics Data System (ADS)

Boisvert, Ghyslain

Cette these est consacree a l'etude des processus de diffusion en surface dans le but ultime de comprendre, et de modeliser, la croissance d'une couche mince. L'importance de bien mai triser la croissance est primordiale compte tenu de son role dans la miniaturisation des circuits electroniques. Nous etudions ici les surface des metaux nobles et de ceux de la fin de la serie de transition. Dans un premier temps, nous nous interessons a la diffusion d'un simple adatome sur une surface metallique. Nous avons, entre autres, mis en evidence l'apparition d'une correlation entre evenements successifs lorsque la temperature est comparable a la barriere de diffusion, i.e., la diffusion ne peut pas etre associee a une marche aleatoire. Nous proposons un modele phenomenologique simple qui reproduit bien les resultats des simulations. Ces calculs nous ont aussi permis de montrer que la diffusion obeit a la loi de Meyer-Neldel. Cette loi stipule que, pour un processus active, le prefacteur augmente exponentiellement avec la barriere. En plus, ce travail permet de clarifier l'origine physique de cette loi. En comparant les resultats dynamiques aux resultats statiques, on se rend compte que la barriere extraite des calculs dynamiques est essentiellement la meme que celle obtenue par une approche statique, beaucoup plus simple. On peut donc obtenir cette barriere a l'aide de methodes plus precises, i.e., ab initio, comme la theorie de la fonctionnelle de la densite, qui sont aussi malheureusement beaucoup plus lourdes. C'est ce que nous avons fait pour plusieurs systemes metalliques. Nos resultats avec cette derniere approche se comparent tres bien aux resultats experimentaux. Nous nous sommes attardes plus longuement a la surface (111) du platine. Cette surface regorge de particularites interessantes, comme la forme d'equilibre non-hexagonale des i lots et deux sites d'adsorption differents pour l'adatome. De plus, des calculs ab initio precedents n'ont pas reussi a confirmer la forme d'equilibre et surestiment grandement la barriere. Nos calculs, plus complets et dans un formalisme mieux adapte a ce genre de probleme, predisent correctement la forme d'equilibre, qui est en fait due a un relachement different du stress de surface aux deux types de marches qui forment les cotes des i lots. Notre valeur pour la barriere est aussi fortement diminuee lorsqu'on relaxe les forces sur les atomes de la surface, amenant le resultat theorique beaucoup plus pres de la valeur experimentale. Nos calculs pour le cuivre demontre en effet que la diffusion de petits i lots pendant la croissance ne peut pas etre negligee dans ce cas, mettant en doute la valeur des interpretations des mesures experimentales. (Abstract shortened by UMI.)

Modelisation de la Propagation des Ondes Sonores dans un Environnement Naturel Complexe

NASA Astrophysics Data System (ADS)

L'Esperance, Andre

Ce travail est consacre a la propagation sonore a l'exterieur dans un environnement naturel complexe, i.e. en presence de conditions reelles de vent, de gradient de temperature et de turbulence atmospherique. Plus specifiquement ce travail comporte deux objectifs. D'une part, il vise a developper un modele heuristique de propagation sonore (MHP) permettant de prendre en consideration l'ensemble des phenomenes meteorologiques et acoustiques influencant la propagation du son a l'exterieur. D'autre part, il vise a identifier dans quelles circonstances et avec quelle importance les conditions meteorologiques interviennent sur la propagation sonore. Ce travail est divise en cinq parties. Apres une breve introduction identifiant les motivations de cette etude (chapitre 1), le chapitre 2 fait un rappel des travaux deja realises dans le domaine de la propagation du son a l'exterieur. Ce chapitre presente egalement les bases de l'acoustique geometrique a partir desquelles ont ete developpees la partie acoustique du modele heuristique de propagation. En outre, on y decrit comment les phenomenes de refraction et de turbulence atmospherique peuvent etre consideres dans la theorie des rayons. Le chapitre 3 presente le modele heuristique de propagation (MHP) developpe au cours de cet ouvrage. La premiere section de ce chapitre decrit le modele acoustique de propagation, modele qui fait l'hypothese d'un gradient de celerite lineaire et qui est base sur une solution hybride d'acoustique geometrique et de theorie des residus. La deuxieme section du chapitre 3 traite plus specifiquement de la modelisation des aspects meteorologiques et de la determination des profils de celerite et des index de fluctuation associes aux conditions meteorologiques. La section 3 de ce chapitre decrit comment les profils de celerite resultants sont linearises pour les calculs dans le modele acoustique, et finalement la section 4 donne les tendances generales obtenues par le modele. Le chapitre 4 decrit les compagnes de mesures qui ont ete realisees a Rock-Spring (Pennsylvanie, Etats -Unis) au cours de l'ete 90 et a Bouin (Vendee, France) au cours de l'automne 91. La campagne de mesure de Rock -Spring a porte plus specifiquement sur les effets de la refraction alors que la campagne de Bouin a prote plus specifiquement sur les effets de la turbulence. La section 4.1 decrit les equipements et le traitement des donnees meteorologiques realisees dans chaque cas et la section 4.2 fait de meme pour les resultats acoustiques. Finalement, le chapitre 5 compare les resultats experimentaux obtenus avec ceux donnes par le MHP, tant pour les resultats meteorologiques que pour les resultats acoustiques. Des comparaisons avec un autre modele (le Fast Field Program) sont egalement presentees.

Comparison of ensemble post-processing approaches, based on empirical and dynamical error modelisation of rainfall-runoff model forecasts

NASA Astrophysics Data System (ADS)

Chardon, J.; Mathevet, T.; Le Lay, M.; Gailhard, J.

2012-04-01

In the context of a national energy company (EDF : Electricité de France), hydro-meteorological forecasts are necessary to ensure safety and security of installations, meet environmental standards and improve water ressources management and decision making. Hydrological ensemble forecasts allow a better representation of meteorological and hydrological forecasts uncertainties and improve human expertise of hydrological forecasts, which is essential to synthesize available informations, coming from different meteorological and hydrological models and human experience. An operational hydrological ensemble forecasting chain has been developed at EDF since 2008 and is being used since 2010 on more than 30 watersheds in France. This ensemble forecasting chain is characterized ensemble pre-processing (rainfall and temperature) and post-processing (streamflow), where a large human expertise is solicited. The aim of this paper is to compare 2 hydrological ensemble post-processing methods developed at EDF in order improve ensemble forecasts reliability (similar to Monatanari &Brath, 2004; Schaefli et al., 2007). The aim of the post-processing methods is to dress hydrological ensemble forecasts with hydrological model uncertainties, based on perfect forecasts. The first method (called empirical approach) is based on a statistical modelisation of empirical error of perfect forecasts, by streamflow sub-samples of quantile class and lead-time. The second method (called dynamical approach) is based on streamflow sub-samples of quantile class and streamflow variation, and lead-time. On a set of 20 watersheds used for operational forecasts, results show that both approaches are necessary to ensure a good post-processing of hydrological ensemble, allowing a good improvement of reliability, skill and sharpness of ensemble forecasts. The comparison of the empirical and dynamical approaches shows the limits of the empirical approach which is not able to take into account hydrological dynamic and processes, i. e. sample heterogeneity. For a same streamflow range corresponds different processes such as rising limbs or recession, where uncertainties are different. The dynamical approach improves reliability, skills and sharpness of forecasts and globally reduces confidence intervals width. When compared in details, the dynamical approach allows a noticeable reduction of confidence intervals during recessions where uncertainty is relatively lower and a slight increase of confidence intervals during rising limbs or snowmelt where uncertainty is greater. The dynamic approach, validated by forecaster's experience that considered the empirical approach not discriminative enough, improved forecaster's confidence and communication of uncertainties. Montanari, A. and Brath, A., (2004). A stochastic approach for assessing the uncertainty of rainfall-runoff simulations. Water Resources Research, 40, W01106, doi:10.1029/2003WR002540. Schaefli, B., Balin Talamba, D. and Musy, A., (2007). Quantifying hydrological modeling errors through a mixture of normal distributions. Journal of Hydrology, 332, 303-315.

Compact all-fiber quartz-enhanced photoacoustic spectroscopy sensor with a 30.72 kHz quartz tuning fork and spatially resolved trace gas detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Yufei, E-mail: mayufei@hit.edu.cn; Post-doctoral Mobile Station of Power Engineering and Engineering Thermophysics, Harbin Institute of Technology, Harbin 150001; He, Ying

An ultra compact all-fiber quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor using quartz tuning fork (QTF) with a low resonance frequency of 30.72 kHz was demonstrated. Such a sensor architecture has the advantages of easier optical alignment, lower insertion loss, lower cost, and more compact compared with a conventional QEPAS sensor using discrete optical components for laser delivery and coupling to the QTF. A fiber beam splitter and three QTFs were employed to perform multi-point detection and demonstrated the potential of spatially resolved measurements.

Magnetotail Reconnection

NASA Astrophysics Data System (ADS)

Petrukovich, A.; Artemyev, A.; Nakamura, R.

Reconnection is the key process responsible for the magnetotail dynamics. Driven reconnection in the distant tail is not sufficient to support global magnetospheric convection and the near Earth neutral line spontaneously forms to restore the balance. Mechanisms of initiation of such near-Earth magnetotail reconnection still represent one of major unresolved issues in space physics. We review the progress in this topic during the last decade. Recent theoretical advances suggest several variants of overcoming the famous tearing stability problem. Multipoint spacecraft observations reveal detailed structure of pre-onset current sheet of and reconnection zone down to ion larmor scale, supporting the importance of unstable state development through internal magnetotail reconfiguration.

Understanding Plasma Interactions with the Atmosphere: The Geospace Electrodynamic Connections (GEC) Mission

NASA Technical Reports Server (NTRS)

2001-01-01

The Geospace Electrodynamic Connections (GEC) mission is a multispacecraft Solar-Terrestrial Probe that has been specifically designed to advance the level of physical insight of our understanding of the coupling among the ionosphere, thermosphere, and magnetosphere. GEC is NASA's fifth Solar-Terrestrial Probe. Through multipoint measurements in the Earth's ionosphere-thermosphere (I-T) system, GEC will (i) discover the spatial and temporal scales on which magnetospheric energy input into the I-T region occurs, (ii) determine the spatial and temporal scales for the response of the I-T system to this input of energy, and (iii) quantify the altitude dependence of the response.

Fuel dissipater for pressurized fuel cell generators

DOEpatents

Basel, Richard A.; King, John E.

2003-11-04

An apparatus and method are disclosed for eliminating the chemical energy of fuel remaining in a pressurized fuel cell generator (10) when the electrical power output of the fuel cell generator is terminated during transient operation, such as a shutdown; where, two electrically resistive elements (two of 28, 53, 54, 55) at least one of which is connected in parallel, in association with contactors (26, 57, 58, 59), a multi-point settable sensor relay (23) and a circuit breaker (24), are automatically connected across the fuel cell generator terminals (21, 22) at two or more contact points, in order to draw current, thereby depleting the fuel inventory in the generator.

Spectral contents readout of birefringent sensor

NASA Technical Reports Server (NTRS)

Redner, Alex S.

1989-01-01

The technical objective of this research program was to develop a birefringent sensor, capable of measuring strain/stress up to 2000 F and a readout system based on Spectral Contents analysis. As a result of the research work, a data acquisition system was developed, capable of measuring strain birefringence in a sensor at 2000 F, with multi-point static and dynamic capabilities. The system uses a dedicated spectral analyzer for evaluation of stress-birefringence and a PC-based readout. Several sensor methods were evaluated. Fused silica was found most satisfactory. In the final evaluation, measurements were performed up to 2000 F and the system performance exceeded expectations.

[Investigation on antibacterial activity of Forsythia suspense Vahl in vitro with Mueller-Hinton agar].

PubMed

Li, Z X; Wang, X H; Zhao, J H; Yang, J F; Wang, X

2000-12-01

To evaluate the antibacterial activity of Forsythia suspensa in vitro with different media. MIC determination of Forsythia suspensa against Staphylococci was performed by the agar dilution method. MIC90 of decoction of Forsythia suspensa against Staphylococcus epidermidis in M-H agar was 1:640, but in nutrient agar 1:40, the antibacterial activity with M-H agar being 16 fold higher than nutrient agar. The M-H agar should be recommended to replace nutrient agar as medium in the antibacterial experiment of Traditional Chinese medicine, and it is better to use multipoint inoculating device in the sensitivity test.

Calculating the Motion and Direction of Flux Transfer Events with Cluster

NASA Technical Reports Server (NTRS)

Collado-Vega, Yaireska M.; Sibeck, David Gary

2011-01-01

We use multi-point timing analysis to determine the orientation and motion of flux transfer events (FTEs) detected by the four Cluster spacecraft on the high-latitude dayside and flank magnetopause during 2002 and 2003. During these years, the distances between the Cluster spacecraft were greater than 1000 km, providing the tetrahedral configuration needed to select events and determine velocities. Each velocity and location will be examined in detail and compared to the velocities and locations determined by the predictions of the component and antiparallel reconnection models for event formation, orientation, motion, and acceleration for a wide range of spacecraft locations and solar wind conditions.

Issues in providing a reliable multicast facility

NASA Technical Reports Server (NTRS)

Dempsey, Bert J.; Strayer, W. Timothy; Weaver, Alfred C.

1990-01-01

Issues involved in point-to-multipoint communication are presented and the literature for proposed solutions and approaches surveyed. Particular attention is focused on the ideas and implementations that align with the requirements of the environment of interest. The attributes of multicast receiver groups that might lead to useful classifications, what the functionality of a management scheme should be, and how the group management module can be implemented are examined. The services that multicasting facilities can offer are presented, followed by mechanisms within the communications protocol that implements these services. The metrics of interest when evaluating a reliable multicast facility are identified and applied to four transport layer protocols that incorporate reliable multicast.

Optimal sixteenth order convergent method based on quasi-Hermite interpolation for computing roots.

PubMed

Zafar, Fiza; Hussain, Nawab; Fatimah, Zirwah; Kharal, Athar

2014-01-01

We have given a four-step, multipoint iterative method without memory for solving nonlinear equations. The method is constructed by using quasi-Hermite interpolation and has order of convergence sixteen. As this method requires four function evaluations and one derivative evaluation at each step, it is optimal in the sense of the Kung and Traub conjecture. The comparisons are given with some other newly developed sixteenth-order methods. Interval Newton's method is also used for finding the enough accurate initial approximations. Some figures show the enclosure of finitely many zeroes of nonlinear equations in an interval. Basins of attractions show the effectiveness of the method.

Multipoint sensing with a low-coherence source using single-arm frequency-shifted interferometry

DOE PAGES

Zhang, Yiwei; Ye, Fei; Qi, Bing; ...

2016-07-12

We demonstrate that multiple-site sensing along an optical fiber can be done with incoherent continuous-wave light. Here, using a broadband low-coherence noise source, a slow detector, and an optical modulator, we construct a single-arm frequency-shifted interferometer (SA-FSI) capable of simultaneously sensing multiple weak-reflection sites distributed either in parallel or in series along fiber links. By scanning the driving frequency of an electro-optic amplitude modulator in the range of 2.7–3.2 GHz at steps of 41.7 KHz, we demonstrate a spatial resolution of 0.3 m and a measurement range of over 1 km.

Complete genomic screen in late-onset familial Alzheimer disease. Evidence for a new locus on chromosome 12.

PubMed

Pericak-Vance, M A; Bass, M P; Yamaoka, L H; Gaskell, P C; Scott, W K; Terwedow, H A; Menold, M M; Conneally, P M; Small, G W; Vance, J M; Saunders, A M; Roses, A D; Haines, J L

1997-10-15

Four genetic loci have been identified as contributing to Alzheimer disease (AD), including the amyloid precursor protein gene, the presenilin 1 gene, the presenilin 2 gene, and the apolipoprotein E gene, but do not account for all the genetic risk for AD. To identify additional genetic risk factors for late-onset AD. A complete genomic screen was performed (N=280 markers). Critical values for chromosomal regional follow-up were a P value of .05 or less for affected relative pair analysis or sibpair analysis, a parametric lod score of 1.0 or greater, or both. Regional follow-up included analysis of additional markers and a second data set. Clinic populations in the continental United States. From a series of multiplex families affected with late-onset (> or =60 years) AD ascertained during the last 14 years (National Insititute of Neurological Disorders and Stroke-Alzheimer's Disease and Related Disorders Association diagnostic criteria) and for which DNA has been obtained, a subset of 16 families (135 total family members, 52 of whom were patients with AD) was used for the genomic screen. A second subset of 38 families (216 total family members, 89 of whom were patients with AD) was used for the follow-up analysis. Linkage analysis results generated using both genetic model-dependent (lod score) and model-independent methods. Fifteen chromosomal regions warranted initial follow-up. Follow-up analyses revealed 4 regions of continued interest on chromosomes 4, 6, 12, and 20, with the strongest results observed forchromosome 12. Peak 2-point affecteds-only lod scores (n=54) were 1.3, 1.6, 2.7, and 2.2 and affected relative pairs P values (n=54) were .04, .03, .14, and .04 for D12S373, D12S1057, D12S1042, and D12S390, respectively. Sibpair analysis (n=54) resulted in maximum lod scores (MLSs) of 1.5, 2.6, 3.2, and 2.3 for these markers, with a peak multipoint MLS of 3.5. A priori stratification by APOE genotype identified 27 families that had at least 1 member with AD whose genotype did not contain an APOE*4 allele. Analysis of these 27 families resulted in MLSs of 1.0, 2.4, 3.7, and 3.3 and a peak multipoint MLS of 3.9. A complete genomic screen in families affected with late-onset AD identified 4 regions of interest after follow-up. Chromosome 12 gave the strongest and most consistent results with a peak multipoint MLS of 3.5, suggesting that this region contains a new susceptibility gene for AD. Additional analyses are necessary to identify the chromosome 12 susceptibility gene for AD and to follow up the regions of interest on chromosomes 4, 6, and 20.

Investigation of aerodynamic design issues with regions of separated flow

NASA Technical Reports Server (NTRS)

Gally, Tom

1993-01-01

Existing aerodynamic design methods have generally concentrated on the optimization of airfoil or wing shapes to produce a minimum drag while satisfying some basic constraints such as lift, pitching moment, or thickness. Since the minimization of drag almost always precludes the existence of separated flow, the evaluation and validation of these design methods for their robustness and accuracy when separated flow is present has not been aggressively pursued. However, two new applications for these design tools may be expected to include separated flow and the issues of aerodynamic design with this feature must be addressed. The first application of the aerodynamic design tools is the design of airfoils or wings to provide an optimal performance over a wide range of flight conditions (multipoint design). While the definition of 'optimal performance' in the multipoint setting is currently being hashed out, it is recognized that given a wide range of flight conditions, it will not be possible to ensure a minimum drag constraint at all conditions, and in fact some amount of separated flow (presumably small) may have to be allowed at the more demanding flight conditions. Thus a multipoint design method must be tolerant of the existence of separated flow and may include some controls upon its extent. The second application is in the design of wings with extended high speed buffet boundaries of their flight envelopes. Buffet occurs on a wing when regions of flow separation have grown to the extent that their time varying pressures induce possible destructive effects upon the wing structure or adversely effect either the aircraft controllability or passenger comfort. A conservative approach to the expansion of the buffet flight boundary is to simply expand the flight envelope of nonseparated flow under the assumption that buffet will also thus be alleviated. However, having the ability to design a wing with separated flow and thus to control the location, extent and severity of the separated flow regions may allow aircraft manufacturers to gain an advantage in the early design stages of an aircraft, when configuration changes are relatively inexpensive to make. The goal of the summer research at NASA Langley Research Center (LaRC) was twofold: first, to investigate a particular airfoil design problem observed under conditions of strong shock induced flow separation on the upper surface of an airfoil at transonic conditions; and second, to suggest and investigate design methodologies for the prediction (or detection) and control of flow separation. The context of both investigations was to use an existing two dimensional Navier-Stokes flow solver and the constrained direct/iterative surface curvature (CDISC) design algorithm developed at LaRC. As a lead in to the primary task, it was necessary to gain a familiarity with both the design method and the computational analysis and to perform the FORTRAN coding needed to couple them together.

Evolution of auroral acceleration region field-aligned current systems, plasma, and potentials observed by Cluster during substorms

NASA Astrophysics Data System (ADS)

Hull, A. J.; Chaston, C. C.; Fillingim, M. O.; Frey, H. U.; Goldstein, M. L.; Bonnell, J. W.; Mozer, F.

2015-12-01

The auroral acceleration region is an integral link in the chain of events that transpire during substorms, and the currents, plasma and electric fields undergo significant changes driven by complex dynamical processes deep in the magnetotail. The acceleration processes that occur therein accelerate and heat the plasma that ultimately leads to some of the most intense global substorm auroral displays. Though this region has garnered considerable attention, the temporal evolution of field-aligned current systems, associated acceleration processes, and resultant changes in the plasma constituents that occur during key stages of substorm development remain unclear. In this study we present a survey of Cluster traversals within and just above the auroral acceleration region (≤3 Re altitude) during substorms. Particular emphasis is on the spatial morphology and developmental sequence of auroral acceleration current systems, potentials and plasma constituents, with the aim of identifying controlling factors, and assessing auroral emmission consequences. Exploiting multi-point measurements from Cluster in combination with auroral imaging, we reveal the injection powered, Alfvenic nature of both the substorm onset and expansion of auroral particle acceleration. We show evidence that indicates substorm onsets are characterized by the gross-intensification and filamentation/striation of pre-existing large-scale current systems to smaller/dispersive scale Alfven waves. Such an evolutionary sequence has been suggested in theoretical models or single spacecraft data, but has not been demonstrated or characterized in multispacecraft observations until now. It is also shown how the Alfvenic variations over time may dissipate to form large-scale inverted-V structures characteristic of the quasi-static aurora. These findings suggest that, in addition to playing active roles in driving substorm aurora, inverted-V and Alfvenic acceleration processes are causally linked. Key elements of substorm current spatial structure and temporal development, relationship to electric fields/potentials, plasma moment and distribution features, causal linkages to auroral emission features, and other properties will be discussed.

A tangent-ring optical TWDM-MAN enabling three-level transregional reconfigurations and shared protections by multipoint distributed control

NASA Astrophysics Data System (ADS)

Gou, Kaiyu; Gan, Chaoqin; Zhang, Xiaoyu; Zhang, Yuchao

2018-03-01

An optical time-and-wavelength-division-multiplexing metro-access network (TWDM-MAN) is proposed and demonstrated in this paper. By the reuse of tangent-ring optical distribution network and the design of distributed control mechanism, ONUs needing to communicate with each other can be flexibly accessed to successfully make up three kinds of reconfigurable networks. By the nature advantage of ring topology in protection, three-level comprehensive protections covering both feeder and distribution fibers are also achieved. Besides, a distributed wavelength allocation (DWA) is designed to support efficient parallel upstream transmission. The analyses including capacity, congestion and transmission simulation show that this network has a great performance.

Modeling damaged wings: Element selection and constraint specification

NASA Technical Reports Server (NTRS)

Stronge, W. J.

1975-01-01

The NASTRAN analytical program was used for structural design, and no problems were anticipated in applying this program to a damaged structure as long as the deformations were small and the strains remained within the elastic range. In this context, NASTRAN was used to test three-dimensional analytical models of a damaged aircraft wing under static loads. A comparison was made of calculated and experimentally measured strains on primary structural components of an RF-84F wing. This comparison brought out two sensitive areas in modeling semimonocoque structures. The calculated strains were strongly affected by the type of elements used adjacent to the damaged region and by the choice of multipoint constraints sets on the damaged boundary.

Coordinated science with the Solar Orbiter, Solar Probe Plus, Interhelioprobe and SPORT missions

NASA Astrophysics Data System (ADS)

Maksimovic, Milan; Vourlidas, Angelos; Zimovets, Ivan; Velli, Marco; Zhukov, Andrei; Kuznetsov, Vladimir; Liu, Ying; Bale, Stuart; Ming, Xiong

The concurrent science operations of the ESA Solar Orbiter (SO), NASA Solar Probe Plus (SPP), Russian Interhelioprobe (IHP) and Chinese SPORT missions will offer a truly unique epoch in heliospheric science. While each mission will achieve its own important science objectives, taken together the four missions will be capable of doing the multi-point measurements required to address many problems in Heliophysics such as the coronal origin of the solar wind plasma and magnetic field or the way the Solar transients drive the heliospheric variability. In this presentation, we discuss the capabilities of the four missions and the Science synergy that will be realized by concurrent operations

Full potential methods for analysis/design of complex aerospace configurations

NASA Technical Reports Server (NTRS)

Shankar, Vijaya; Szema, Kuo-Yen; Bonner, Ellwood

1986-01-01

The steady form of the full potential equation, in conservative form, is employed to analyze and design a wide variety of complex aerodynamic shapes. The nonlinear method is based on the theory of characteristic signal propagation coupled with novel flux biasing concepts and body-fitted mapping procedures. The resulting codes are vectorized for the CRAY XMP and the VPS-32 supercomputers. Use of the full potential nonlinear theory is demonstrated for a single-point supersonic wing design and a multipoint design for transonic maneuver/supersonic cruise/maneuver conditions. Achievement of high aerodynamic efficiency through numerical design is verified by wind tunnel tests. Other studies reported include analyses of a canard/wing/nacelle fighter geometry.

Multi-Point Hermes Acoustic Modem for High-Speed, High-Frequency Acoustic Communications with Low-Frequency Acoustic Control Loop for Real-Time Transmission of AUV-Carried High-Resolution Images and Navigation Data in Support of Ship Hulls Inspection

DTIC Science & Technology

2013-08-31

13.3 µs) used in the data frame. The preamble uses direct-sequence spread spectrum (DSSS) to reduce the negative impact of fading. Three bits... ifr t covers one of the allocated hops of index  h i . The received reference symbol transmitted in hop   1,2,..., Hh i N is    ( )h...are recovered based on the phase difference between the constellation points demodulated from the sub-band m of the information symbol  ( ) ifr t

The Boeing plastic analysis capability for engines

NASA Technical Reports Server (NTRS)

Vos, R. G.

1976-01-01

The current BOPACE program is described as a nonlinear stress analysis program, which is based on a family of isoparametric finite elements. The theoretical, user, programmer, preprocessing aspects are discussed, and example problems are included. New features in the current program version include substructuring, an out-of-core Gauss wavefront equation solver, multipoint constraints, combined material and geometric nonlinearities, automatic calculation of inertia effects, provision for distributed as well as concentrated mechanical loads, follower forces, singular crack-tip elements, the SAIL automatic generation capability, and expanded user control over input quantity definition, output selection, and program execution. BOPACE is written in FORTRAN 4 and is currently available for both the IBM 360/370 and the UNIVAC 1108 machines.

Thermal Modeling in Support of the Edison Demonstration of Smallsat Networks Project

NASA Technical Reports Server (NTRS)

Coker, Robert

2013-01-01

NASA's Edison program is intending to launch a swarm of at least 8 small satellites in 2013. This swarm of 1.5U Cubesats, the Edison Demonstration of Smallsat Networks (EDSN) project, will demonstrate intra-swarm communications and multi-point in-situ space physics data acquisition. In support of the design and testing of the EDSN satellites, a geometrically accurate thermal model has been constructed. Due to the low duty cycle of most components, no significant overheating issues were found. The predicted mininum temperatures of the external antennas are low enough, however, that some mitigation may be in order. The development and application of the model will be discussed in detail.

A rotating hot-wire technique for spatial sampling of disturbed and manipulated duct flows

NASA Technical Reports Server (NTRS)

Wark, C. E.; Nagib, H. M.; Jennings, M. J.

1990-01-01

A duct flow spatial sampling technique, in which an X-wire probe is rotated about the center of a cylindrical test section at a radius equal to one-half that of the test section in order to furnish nearly instantaneous multipoint measurements of the streamwise and azimuthal components, is presently evaluated in view of the control of flow disturbances downstream of various open inlet contractions. The effectiveness of a particular contraction in controlling ingested flow disturbances was ascertained by artificially introducing disturbances upstream of the contractions; control effectiveness if found to be strongly dependent on inlet contraction, with consequences for the reduction of passing-blade frequency noise during gas turbine engine ground testing.

Performance Analysis and Design Synthesis (PADS) computer program. Volume 2: Program description, part 2

NASA Technical Reports Server (NTRS)

1972-01-01

The QL module of the Performance Analysis and Design Synthesis (PADS) computer program is described. Execution of this module is initiated when and if subroutine PADSI calls subroutine GROPE. Subroutine GROPE controls the high level logical flow of the QL module. The purpose of the module is to determine a trajectory that satisfies the necessary variational conditions for optimal performance. The module achieves this by solving a nonlinear multi-point boundary value problem. The numerical method employed is described. It is an iterative technique that converges quadratically when it does converge. The three basic steps of the module are: (1) initialization, (2) iteration, and (3) culmination. For Volume 1 see N73-13199.

A calibration method of infrared LVF based spectroradiometer

NASA Astrophysics Data System (ADS)

Liu, Jiaqing; Han, Shunli; Liu, Lei; Hu, Dexin

2017-10-01

In this paper, a calibration method of LVF-based spectroradiometer is summarize, including spectral calibration and radiometric calibration. The spectral calibration process as follow: first, the relationship between stepping motor's step number and transmission wavelength is derivative by theoretical calculation, including a non-linearity correction of LVF;second, a line-to-line method was used to corrected the theoretical wavelength; Finally, the 3.39 μm and 10.69 μm laser is used for spectral calibration validation, show the sought 0.1% accuracy or better is achieved.A new sub-region multi-point calibration method is used for radiometric calibration to improving accuracy, results show the sought 1% accuracy or better is achieved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hellsten, E.; Vesa, J.; Peltonen, L.

Infantile neuronal ceroid lipofuscinosis, INCL, CLN1, is an autosomally inherited progressive neuro-generative disorder. The disease results in the massive death of cortical neurons, suggesting an essential role for the CLN1 gene product in the normal neuronal maturation during the first years of life. Identification of new multiallelic markers has now made possible the construction of a refined genetic map encompassing the CLN1 locus at 1p32. Strong allelic association was detected with a new, highly polymorphic HY-TM1 marker. The authors incorporated this observed linkage disequilibrium into multipoint linkage analysis, which significantly increased the informativeness of the limited family material and facilitatedmore » refined assignment of the CLN1 locus. 23 refs., 2 figs., 4 tabs.« less

Compact "diode-based" multi-energy soft x-ray diagnostic for NSTX.

PubMed

Tritz, K; Clayton, D J; Stutman, D; Finkenthal, M

2012-10-01

A novel and compact, diode-based, multi-energy soft x-ray (ME-SXR) diagnostic has been developed for the National Spherical Tokamak Experiment. The new edge ME-SXR system tested on NSTX consists of a set of vertically stacked diode arrays, each viewing the plasma tangentially through independent pinholes and filters providing an overlapping view of the plasma midplane which allows simultaneous SXR measurements with coarse sub-sampling of the x-ray spectrum. Using computed x-ray spectral emission data, combinations of filters can provide fast (>10 kHz) measurements of changes in the electron temperature and density profiles providing a method to "fill-in" the gaps of the multi-point Thomson scattering system.

CARHTA GENE: multipopulation integrated genetic and radiation hybrid mapping.

PubMed

de Givry, Simon; Bouchez, Martin; Chabrier, Patrick; Milan, Denis; Schiex, Thomas

2005-04-15

CAR(H)(T)A GENE: is an integrated genetic and radiation hybrid (RH) mapping tool which can deal with multiple populations, including mixtures of genetic and RH data. CAR(H)(T)A GENE: performs multipoint maximum likelihood estimations with accelerated expectation-maximization algorithms for some pedigrees and has sophisticated algorithms for marker ordering. Dedicated heuristics for framework mapping are also included. CAR(H)(T)A GENE: can be used as a C++ library, through a shell command and a graphical interface. The XML output for companion tools is integrated. The program is available free of charge from www.inra.fr/bia/T/CarthaGene for Linux, Windows and Solaris machines (with Open Source). tschiex@toulouse.inra.fr.

Architecture for on-die interconnect

DOEpatents

Khare, Surhud; More, Ankit; Somasekhar, Dinesh; Dunning, David S.

2016-03-15

In an embodiment, an apparatus includes: a plurality of islands configured on a semiconductor die, each of the plurality of islands having a plurality of cores; and a plurality of network switches configured on the semiconductor die and each associated with one of the plurality of islands, where each network switch includes a plurality of output ports, a first set of the output ports are each to couple to the associated network switch of an island via a point-to-point interconnect and a second set of the output ports are each to couple to the associated network switches of a plurality of islands via a point-to-multipoint interconnect. Other embodiments are described and claimed.

La conception, la modelisation et la simulation du systeme VSC-HVDC offshore

NASA Astrophysics Data System (ADS)

Benhalima, Seghir

Wind energy is recognized worldwide as a proven technology to meet the growing demands of green sustainable energy. To exploit this stochastic energy source and put together with the conventional energy sources without affecting the performance of existing electrical grids, several research projects have been achieved. In addition, at ocean level, wind energy has a great potential. It means that the production of this energy will increase in the world. The optimal extraction of this energy source needs to be connected to the grid via a voltage source converter which plays the role of interface. To minimise losses due to the transport of energy at very long distances, the technology called High Voltage Direct Current based on Voltage Source Converter (VSC-HVDC) is used. To achieve this goal, a new topology is designed with a new control algorithm based on control of power generated by the wind farm, the DC voltage regulation and the synchronization between wind farm and VSC-HVDC (based on NPC). The proposed topology and its control technique are validated using the "MATLAB/Simulink program". The results are promising, because the THD is less than 5% and the power factor is close to one.

MONET: multidimensional radiative cloud scene model

NASA Astrophysics Data System (ADS)

Chervet, Patrick

1999-12-01

All cloud fields exhibit variable structures (bulge) and heterogeneities in water distributions. With the development of multidimensional radiative models by the atmospheric community, it is now possible to describe horizontal heterogeneities of the cloud medium, to study these influences on radiative quantities. We have developed a complete radiative cloud scene generator, called MONET (French acronym for: MOdelisation des Nuages En Tridim.) to compute radiative cloud scene from visible to infrared wavelengths for various viewing and solar conditions, different spatial scales, and various locations on the Earth. MONET is composed of two parts: a cloud medium generator (CSSM -- Cloud Scene Simulation Model) developed by the Air Force Research Laboratory, and a multidimensional radiative code (SHDOM -- Spherical Harmonic Discrete Ordinate Method) developed at the University of Colorado by Evans. MONET computes images for several scenario defined by user inputs: date, location, viewing angles, wavelength, spatial resolution, meteorological conditions (atmospheric profiles, cloud types)... For the same cloud scene, we can output different viewing conditions, or/and various wavelengths. Shadowing effects on clouds or grounds are taken into account. This code is useful to study heterogeneity effects on satellite data for various cloud types and spatial resolutions, and to determine specifications of new imaging sensor.

Etude vibroacoustique d'un systeme coque-plancher-cavite avec application a un fuselage simplifie

NASA Astrophysics Data System (ADS)

Missaoui, Jemai

L'objectif de ce travail est de developper des modeles semi-analytiques pour etudier le comportement structural, acoustique et vibro-acoustique d'un systeme coque-plancher-cavite. La connection entre la coque et le plancher est assuree en utilisant le concept de rigidite artificielle. Ce concept de modelisation flexible facilite le choix des fonctions de decomposition du mouvement de chaque sous-structure. Les resultats issus de cette etude vont permettre la comprehension des phenomenes physiques de base rencontres dans une structure d'avion. Une approche integro-modale est developpee pour calculer les caracteristiques modales acoustiques. Elle utilise une discretisation de la cavite irreguliere en sous-cavites acoustiques dont les bases de developpement sont connues a priori. Cette approche, a caractere physique, presente l'avantage d'etre efficace et precise. La validite de celle-ci a ete demontree en utilisant des resultats disponibles dans la litterature. Un modele vibro-acoustique est developpe dans un but d'analyser et de comprendre les effets structuraux et acoustiques du plancher dans la configuration. La validite des resultats, en termes de resonance et de fonction de transfert, est verifiee a l'aide des mesures experimentales realisees au laboratoire.

Hidden Markov random field model and Broyden-Fletcher-Goldfarb-Shanno algorithm for brain image segmentation

NASA Astrophysics Data System (ADS)

Guerrout, EL-Hachemi; Ait-Aoudia, Samy; Michelucci, Dominique; Mahiou, Ramdane

2018-05-01

Many routine medical examinations produce images of patients suffering from various pathologies. With the huge number of medical images, the manual analysis and interpretation became a tedious task. Thus, automatic image segmentation became essential for diagnosis assistance. Segmentation consists in dividing the image into homogeneous and significant regions. We focus on hidden Markov random fields referred to as HMRF to model the problem of segmentation. This modelisation leads to a classical function minimisation problem. Broyden-Fletcher-Goldfarb-Shanno algorithm referred to as BFGS is one of the most powerful methods to solve unconstrained optimisation problem. In this paper, we investigate the combination of HMRF and BFGS algorithm to perform the segmentation operation. The proposed method shows very good segmentation results comparing with well-known approaches. The tests are conducted on brain magnetic resonance image databases (BrainWeb and IBSR) largely used to objectively confront the results obtained. The well-known Dice coefficient (DC) was used as similarity metric. The experimental results show that, in many cases, our proposed method approaches the perfect segmentation with a Dice Coefficient above .9. Moreover, it generally outperforms other methods in the tests conducted.

Multi-scale properties of large eddy simulations: correlations between resolved-scale velocity-field increments and subgrid-scale quantities

NASA Astrophysics Data System (ADS)

Linkmann, Moritz; Buzzicotti, Michele; Biferale, Luca

2018-06-01

We provide analytical and numerical results concerning multi-scale correlations between the resolved velocity field and the subgrid-scale (SGS) stress-tensor in large eddy simulations (LES). Following previous studies for Navier-Stokes equations, we derive the exact hierarchy of LES equations governing the spatio-temporal evolution of velocity structure functions of any order. The aim is to assess the influence of the subgrid model on the inertial range intermittency. We provide a series of predictions, within the multifractal theory, for the scaling of correlation involving the SGS stress and we compare them against numerical results from high-resolution Smagorinsky LES and from a-priori filtered data generated from direct numerical simulations (DNS). We find that LES data generally agree very well with filtered DNS results and with the multifractal prediction for all leading terms in the balance equations. Discrepancies are measured for some of the sub-leading terms involving cross-correlation between resolved velocity increments and the SGS tensor or the SGS energy transfer, suggesting that there must be room to improve the SGS modelisation to further extend the inertial range properties for any fixed LES resolution.

Identification of candidate regions for a novel Usher syndrome type II locus.

PubMed

Ben Rebeh, Imen; Benzina, Zeineb; Dhouib, Houria; Hadjamor, Imen; Amyere, Mustapha; Ayadi, Leila; Turki, Khalil; Hammami, Bouthaina; Kmiha, Noureddine; Kammoun, Hassen; Hakim, Bochra; Charfedine, Ilhem; Vikkula, Miikka; Ghorbel, Abdelmonem; Ayadi, Hammadi; Masmoudi, Saber

2008-09-19

Chronic diseases affecting the inner ear and the retina cause severe impairments to our communication systems. In more than half of the cases, Usher syndrome (USH) is the origin of these double defects. Patients with USH type II (USH2) have retinitis pigmentosa (RP) that develops during puberty, moderate to severe hearing impairment with downsloping pure-tone audiogram, and normal vestibular function. Four loci and three genes are known for USH2. In this study, we proposed to localize the gene responsible for USH2 in a consanguineous family of Tunisian origin. Affected members underwent detailed ocular and audiologic characterization. One Tunisian family with USH2 and 45 healthy controls unrelated to the family were recruited. Two affected and six unaffected family members attended our study. DNA samples of eight family members were genotyped with polymorphic markers. Two-point and multipoint LOD scores were calculated using Genehunter software v2.1. Sequencing was used to investigate candidate genes. Haplotype analysis showed no significant linkage to any known USH gene or locus. A genome-wide screen, using microsatellite markers, was performed, allowing the identification of three homozygous regions in chromosomes 2, 4, and 15. We further confirmed and refined these three regions using microsatellite and single-nucleotide polymorphisms. With recessive mode of inheritance, the highest multipoint LOD score of 1.765 was identified for the candidate regions on chromosomes 4 and 15. The chromosome 15 locus is large (55 Mb), underscoring the limited number of meioses in the consanguineous pedigree. Moreover, the linked, homozygous chromosome 15q alleles, unlike those of the chromosome 2 and 4 loci, are infrequent in the local population. Thus, the data strongly suggest that the novel locus for USH2 is likely to reside on 15q. Our data provide a basis for the localization and the identification of a novel gene implicated in USH2, most likely localized on 15q.

Linkage analysis of primary open-angle glaucoma excludes the juvenile glaucoma region on chromosome 1q

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wirtz, M.K.; Acott, T.S.; Samples, J.R.

1994-09-01

The gene for one form of juvenile glaucoma has been mapped to chromosome 1q21-q31. This raises the possibility of primary open-angle glaucoma (POAG) also mapping to this region if the same defective gene causes both diseases. To ask this question linkage analysis was performed on a large POAG kindred. Blood samples or skin biopsies were obtained from 40 members of this family. Individuals were diagnosed as having POAG if they met two or more of the following criteria: (1) Visual field defects compatible with glaucoma on automated perimetry; (2) Optic nerve head and/or nerve fiber layer analysis compatible with glaucomatousmore » damage; (3) high intraocular pressures (> 20 mm Hg). Patients were considered glaucoma suspects if they only met one criterion. These individuals were excluded from the analysis. Of the 40 members, seven were diagnosed with POAG; four were termed suspects. The earliest age of onset was 38 years old, while the average age of onset was 65 years old. We performed two-point and multipoint linkage analysis, using five markers which encompass the region 1q21-q31; specifically, D1S194, D1S210, D1S212, D1S191 and LAMB2. Two-point lod scores excluded tight linkage with all markers except D1S212 (maximum lod score of 1.07 at theta = 0.0). In the multipoint analysis, including D1S210-D1S212-LAMB2 and POAG, the entire 11 cM region spanned by these markers was excluded for linkage with POAG; that is, lod scores were < -2.0. In conclusion, POAG in this family does not map to chromosome 1q21-q31 and, thus, they carry a gene that is distinct from the juvenile glaucoma gene.« less

Caucasian Families Exhibit Significant Linkage of Myopia to Chromosome 11p.

PubMed

Musolf, Anthony M; Simpson, Claire L; Moiz, Bilal A; Long, Kyle A; Portas, Laura; Murgia, Federico; Ciner, Elise B; Stambolian, Dwight; Bailey-Wilson, Joan E

2017-07-01

Myopia is a common visual disorder caused by eye overgrowth, resulting in blurry vision. It affects one in four Americans, and its prevalence is increasing. The genetic mechanisms that underpin myopia are not completely understood. Here, we use genotype data and linkage analyses to identify high-risk genetic loci that are significantly linked to myopia. Individuals from 56 Caucasian families with a history of myopia were genotyped on an exome-based array, and the single nucleotide polymorphism (SNP) data were merged with microsatellite genotype data. Refractive error measures on the samples were converted into binary phenotypes consisting of affected, unaffected, or unknown myopia status. Parametric linkage analyses assuming an autosomal dominant model with 90% penetrance and 10% phenocopy rate were performed. Single variant two-point analyses yielded three significantly linked SNPs at 11p14.1 and 11p11.2; a further 45 SNPs at 11p were found to be suggestive. No other chromosome had any significant SNPs or more than seven suggestive linkages. Two of the significant SNPs were located in BBOX1-AS1 and one in the intergenic region between ORA47 and TRIM49B. Collapsed haplotype pattern two-point analysis and multipoint analyses also yielded multiple suggestively linked genes at 11p. Multipoint analysis also identified suggestive evidence of linkage on 20q13. We identified three genome-wide significant linked variants on 11p for myopia in Caucasians. Although the novel specific signals still need to be replicated, 11p is a promising region that has been identified by other linkage studies with a number of potentially interesting candidate genes. We hope that the identification of these regions on 11p as potential causal regions for myopia will lead to more focus on these regions and maybe possible replication of our specific linkage peaks in other studies. We further plan targeted sequencing on 11p for our most highly linked families to more clearly understand the source of the linkage in this region.

ISINGLASS campaign multi point sensors and data integration

NASA Astrophysics Data System (ADS)

Clayton, R.; Lynch, K. A.; Michell, R.; Hampton, D. L.; Samara, M.; Zettergren, M. D.; Hysell, D. L.; Lessard, M.

2016-12-01

The upcoming ISINGLASS mission will take place during February 2017 and will consist of 2 rockets launched out of Poker Flat Research Range, Alaska. Each rocket will deploy sensorcraft on the upleg to generate a localized multipoint measurement of the ionospheric plasma environment. Ground based measurements such as the PFISR and SuperDARN radar arrays, CCD cameras making maps of multi-wavelength energy flux and characteristic energy, and Scanning Doppler Imagers for neutral flows, will also be used in conjunction with the in situ rocket measurements. The GEMINI ionospheric model will be used to stitch together all of the various data products during the mission to provide a map of the relevant parameters during the duration of the campaign. The sensors built by Dartmouth for this mission are called Petite Ion Probes (PIPs), collimated RPAs with heritage on the MICA auroral mission. For the upcoming Isinglass flights, PIPs will be assembled into small ejectables, and four of these sensorcraft will be deployed from each of the two rockets on the upleg, creating a localized swarm for the duration of the flight through the F-region ionosphere. During the science portion of the flight, the sensorcraft will be spaced 1km apart from the main payload, which allows for the multipoint measurement of small-scale gradients in the F-region, such as across the edges of arcs. Interpretation of the data from the PIPs is aided by calibration done at Dartmouth in the Elephant plasma chamber. Comparison between the PIPs, and Langmuir and emissive probe measurements, provides verification of the PIP measurements, as well as verifying the field of view of the detector in the various configurations present on the payload. Observational goals for the campaign target a different type of auroral arc with each of the two rockets. The measured response of the thermal ionospheric plasma to different types and scale sizes of auroral precipitation drivers will provide two case studies quantifying the gradient scale lengths of auroral disturbances.