Sample and length-dependent variability of 77 and 4.2 K properties in nominally identical RE123 coated conductors

NASA Astrophysics Data System (ADS)

Rossi, L.; Hu, X.; Kametani, F.; Abraimov, D.; Polyanskii, A.; Jaroszynski, J.; Larbalestier, D. C.

2016-05-01

We present a broad study by multiple techniques of the critical current and critical current density of a small but representative set of nominally identical commercial RE123 (REBa2Cu3O7-δ , RE = rare Earth, here Y and Gd) coated conductors (CC) recently fabricated by SuperPower Inc. to the same nominal high pinning specification with BaZrO3 and RE2O3 nanoprecipitate pinning centers. With high-field low-temperature applications to magnet technology in mind, we address the nature of their tape-to-tape variations and length-wise I c inhomogeneities by measurements on a scale of about 2 cm rather than the 5 m scale normally supplied by the vendor and address the question of whether these variations have their origin in cross-sectional or in vortex pinning variations. Our principal method has been a continuous measurement transport critical current tool (YateStar) that applies about 0.5 T perpendicular and parallel to the tape at 77 K, thus allowing variations of c-axis and ab-plane properties to be clearly distinguished in the temperature and field regime where strong pinning defects are obvious. We also find such in-field measurements at 77 K to be more valuable in predicting 4.2 K, high-field properties than self-field, 77 K properties because the pinning centers controlling 77 K performance play a decisive role in introducing point defects that also add strongly to J c at 4.2 K. We find that the dominant source of I c variation is due to pinning center fluctuations that control J c, rather than to production defects that locally reduce the active cross-section. Given the 5-10 nm scale of these pinning centers, it appears that the route to greater I c homogeneity is through more stringent control of the REBCO growth conditions in these Zr-doped coated conductors.

Multi-technique characterization of gold electroplating on silver substrates for cultural heritage applications

NASA Astrophysics Data System (ADS)

Ortega-Feliu, I.; Ager, F. J.; Roldán, C.; Ferretti, M.; Juanes, D.; Scrivano, S.; Respaldiza, M. A.; Ferrazza, L.; Traver, I.; Grilli, M. L.

2017-09-01

This work presents a detailed study of a series of silver plates gilded via electroplating techniques in which the characteristics of the coating gold layers are investigated as a function of the electroplating variables (voltage, time, anode surface and temperature). Some reference samples were coated by radio frequency sputtering in order to compare gold layer homogeneity and effective density. Surface analysis was performed by means of atomic and nuclear techniques (SEM-EDX, EDXRF, PIXE and RBS) to obtain information about thickness, homogeneity, effective density, profile concentration of the gold layers and Au-Ag diffusion profiles. The gold layer thickness obtained by PIXE and EDXRF is consistent with the thickness obtained by means of RBS depth profiling. Electroplated gold mass thickness increases with electroplating time, anode area and voltage. However, electrodeposited samples present rough interfaces and gold layer effective densities lower than the nominal density of Au (19.3 g/cm3), whereas sputtering produces uniform layers with nominal density. These analyses provide valuable information to historians and curators and can help the restoration process of gold-plated silver objects.

Implementation and Initial Validation of a 100-Kilowatt Class Nested-Channel Hall Thruster

NASA Technical Reports Server (NTRS)

Hall, Scott J.; Florenz, Roland E.; Gallimore, Alec D.; Kamhawi, Hani; Brown, Daniel L.; Polk, James E.; Goebel, Dan; Hofer, Richard R.

2014-01-01

The X3 is a 100-kilowatt class nested-channel Hall thruster developed by the Plasmadynamics and Electric Propulsion Laboratory at the University of Michigan in collaboration with the Air Force Research Laboratory and NASA. The cathode, magnetic circuit, boron nitride channel rings, and anodes all required specific design considerations during thruster development, and thermal modeling was used to properly account for thermal growth in material selection and component design. A number of facility upgrades were required at the University of Michigan to facilitate operation of the X3. These upgrades included a re-worked propellant feed system, a completely redesigned power and telemetry break-out box, and numerous updates to thruster handling equipment. The X3 was tested on xenon propellant at two current densities, 37% and 73% of the nominal design value. It was operated to a maximum steady-state discharge power of 60.8 kilowatts. The tests presented here served as an initial validation of thruster operation. Thruster behavior was monitored with telemetry, photography and high-speed current probes. The photography showed a uniform plume throughout testing. At constant current density, reductions in mass flow rate of 18% and 26% were observed in the three-channel operating configuration as compared to the superposition of each channel running individually. The high-speed current probes showed that the thruster was stable at all operating points and that the channels influence each other when more than one is operating simultaneously. Additionally, the ratio of peak-to-peak AC-coupled discharge current oscillations to mean discharge current did not exceed 51% for any operating points reported here, and did not exceed 17% at the higher current density.

Pulsed electromagnetic gas accelleration. [incorporation of hollow cathode in plasma discharge and suitability determination of MPD discharge as plasmadynamic laser source

NASA Technical Reports Server (NTRS)

Jahn, R. G.

1973-01-01

Direct measurement with thermocouples of the power deposited in the anode of a multi-megawatt magnetoplasmadynamic discharge has shown the fractional anode power to decrease from 50% at 200 kW to 10% at 20 MW. Using local measurements of current density, electric potential, and electron temperature, the traditional model for heat conduction to the anode is found to be inadequate. Other experiments in which the voltage-current characteristics and exhaust velocities of MPD arcs using Plexiglas and boron nitride chamber insulators and various mass injection configurations show that ablation can affect nominal accelerator operation in several distinct ways. The incorporation of a hollow cathode in a 7 kA plasma discharge has shown that a stable current attachment can be realized in the cavity without the aid of cathode heaters, keeper electrodes, or emissive coatings.

Exploring Nominalization in Scientific Textbooks: A Cross-Disciplinary Study of Hard and Soft Sciences

ERIC Educational Resources Information Center

Jalilifar, Alireza; White, Peter; Malekizadeh, N.

2017-01-01

Given the importance of disciplinary specificity in terms of the potential differences in the functionality of nominalizations in scientific textbooks and the dearth of studies of this type, the current study explores the extent to which nominalization is realized across two disciplines. To this aim, eight academic textbooks from Physics and…

The Role of Peer Nomination Forms in the Identification of Lower Elementary Gifted and Talented Students

ERIC Educational Resources Information Center

Kaya, Fatih

2013-01-01

The purpose of the current study was to determine if the Reynolds Intellectual Assessment Scale (RIAS) scores, as standardized IQ scores, correlate with the children's judgments of their classmates' intelligence, as peer nomination scores, in terms of their power to identify intellectually superior children. Guess Who: Peer Nomination Form (GWPNF)…

Thrust Stand Characterization of the NASA Evolutionary Xenon Thruster (NEXT)

NASA Technical Reports Server (NTRS)

Diamant, Kevin D.; Pollard, James E.; Crofton, Mark W.; Patterson, Michael J.; Soulas, George C.

2010-01-01

Direct thrust measurements have been made on the NASA Evolutionary Xenon Thruster (NEXT) ion engine using a standard pendulum style thrust stand constructed specifically for this application. Values have been obtained for the full 40-level throttle table, as well as for a few off-nominal operating conditions. Measurements differ from the nominal NASA throttle table 10 (TT10) values by 3.1 percent at most, while at 30 throttle levels (TLs) the difference is less than 2.0 percent. When measurements are compared to TT10 values that have been corrected using ion beam current density and charge state data obtained at The Aerospace Corporation, they differ by 1.2 percent at most, and by 1.0 percent or less at 37 TLs. Thrust correction factors calculated from direct thrust measurements and from The Aerospace Corporation s plume data agree to within measurement error for all but one TL. Thrust due to cold flow and "discharge only" operation has been measured, and analytical expressions are presented which accurately predict thrust based on thermal thrust generation mechanisms.

Mesoscale modeling of photoelectrochemical devices: light absorption and carrier collection in monolithic, tandem, Si|WO3 microwires.

PubMed

Fountaine, Katherine T; Atwater, Harry A

2014-10-20

We analyze mesoscale light absorption and carrier collection in a tandem junction photoelectrochemical device using electromagnetic simulations. The tandem device consists of silicon (E(g,Si) = 1.1 eV) and tungsten oxide (E(g,WO3) = 2.6 eV) as photocathode and photoanode materials, respectively. Specifically, we investigated Si microwires with lengths of 100 µm, and diameters of 2 µm, with a 7 µm pitch, covered vertically with 50 µm of WO3 with a thickness of 1 µm. Many geometrical variants of this prototypical tandem device were explored. For conditions of illumination with the AM 1.5G spectra, the nominal design resulted in a short circuit current density, J(SC), of 1 mA/cm(2), which is limited by the WO3 absorption. Geometrical optimization of photoanode and photocathode shape and contact material selection, enabled a three-fold increase in short circuit current density relative to the initial design via enhanced WO3 light absorption. These findings validate the usefulness of a mesoscale analysis for ascertaining optimum optoelectronic performance in photoelectrochemical devices.

Understanding Charge Transport in Mixed Networks of Semiconducting Carbon Nanotubes

PubMed Central

2016-01-01

The ability to select and enrich semiconducting single-walled carbon nanotubes (SWNT) with high purity has led to a fast rise of solution-processed nanotube network field-effect transistors (FETs) with high carrier mobilities and on/off current ratios. However, it remains an open question whether it is best to use a network of only one nanotube species (monochiral) or whether a mix of purely semiconducting nanotubes but with different bandgaps is sufficient for high performance FETs. For a range of different polymer-sorted semiconducting SWNT networks, we demonstrate that a very small amount of narrow bandgap nanotubes within a dense network of large bandgap nanotubes can dominate the transport and thus severely limit on-currents and effective carrier mobility. Using gate-voltage-dependent electroluminescence, we spatially and spectrally reveal preferential charge transport that does not depend on nominal network density but on the energy level distribution within the network and carrier density. On the basis of these results, we outline rational guidelines for the use of mixed SWNT networks to obtain high performance FETs while reducing the cost for purification. PMID:26867006

76 FR 27112 - Self-Regulatory Organizations; C2 Options Exchange, Incorporated; Notice of Filing of a Proposed...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-10

...'') has a Nominating and Governance Committee with a size of four directors.\\3\\ Additionally, it should be... Nominating and Governance Committee and that the Exchange may do so in the future, it is the current... Minimum Size of the Nominating and Governance Committee May 4, 2011. Pursuant to Section 19(b)(1) of the...

All-Solid-State High-Energy Asymmetric Supercapacitors Enabled by Three-Dimensional Mixed-Valent MnOx Nanospike and Graphene Electrodes.

PubMed

Yang, Jie; Li, Guizhu; Pan, Zhenghui; Liu, Meinan; Hou, Yuan; Xu, Yijun; Deng, Hong; Sheng, Leimei; Zhao, Xinluo; Qiu, Yongcai; Zhang, Yuegang

2015-10-14

Three-dimensional (3D) nanostructures enable high-energy storage devices. Here we report a 3D manganese oxide nanospike (NSP) array electrode fabricated by anodization and subsequent electrodeposition. All-solid-state asymmetric supercapacitors were assembled with the 3D Al@Ni@MnOx NSP as the positive electrode, chemically converted graphene (CCG) as the negative electrode, and Na2SO4/poly(vinyl alcohol) (PVA) as the polymer gel electrolyte. Taking advantage of the different potential windows of Al@Ni@MnOx NSP and CCG electrodes, the asymmetric supercapacitor showed an ideal capacitive behavior with a cell voltage up to 1.8 V, capable of lighting up a red LED indicator (nominal voltage of 1.8 V). The device could deliver an energy density of 23.02 W h kg(-1) at a current density of 1 A g(-1). It could also preserve 96.3% of its initial capacitance at a current density of 2 A g(-1) after 10000 charging/discharging cycles. The remarkable performance is attributed to the unique 3D NSP array structure that could play an important role in increasing the effective electrode surface area, facilitating electrolyte permeation, and shortening the electron pathway in the active materials.

Graham nominated to Head OSTP

NASA Astrophysics Data System (ADS)

President Ronald Reagan has nominated William R. Graham as science advisor and director of the Office of Science and Technology (OSTP). Graham, who is currently deputy director of the National Aeronautics and Space Administration (NASA), had been acting director of the agency until the nomination of James C. Fletcher.Graham's nomination, which must be confirmed by the U.S. Senate, comes 6 months after the resignation of George A. Keyworth from the post. John P. McTague had been acting science advisor since Keyworth's resignation (Eos, December 10, 1985, p. 1219).

1310 nm quantum dot DFB lasers with high dot density and ultra-low linewidth-power product

NASA Technical Reports Server (NTRS)

Qiu, Y.; Lester, L. F.; Gray, A. L.; Newell, T. C.; Hains, C.; Gogna, P.; Muller, R.; Maker, P.; Su, H.; Stintz, A.

2002-01-01

Laterally coupled distributed feedback lasers using high-density InAs quantum dots-in-a-well (DWELL) active region demonstrate a nominal wavelength of 1310 nm, a linewidth as small as 68 kHz, and a linewidth-power product of 100 kHz-mW.

Synthesis of Bi.sub.1.8 Pb.sub.0.4 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.x superconductor

DOEpatents

Smith, Michael G.

1996-01-01

Two-powder processes for the synthesis of superconducting (Bi, Pb)-2223/Ag-clad wires by the oxide-powder-in-the-robe are provided. The first precursor powder, of nominal stoichiometry CaCuO.sub.x, is a solution-synthesized mixture of Ca.sub.0.45 Cu.sub.0.55 O.sub.2 and CaO. Using these oxide precursor mixtures, superconducting tapes with well-aligned grains and reproducible critical current densities J.sub.c in the range of 20,000 to 26,000 A/cm.sup.2 at 75 K in self-field after annealing less than 200 hours were obtained.

Synthesis of Bi{sub 1.8}Pb{sub 0.4}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} superconductor

DOEpatents

Smith, M.G.

1996-10-29

Two-powder processes for the synthesis of superconducting (Bi, Pb)-2223/Ag-clad wires by the oxide-powder-in-the-robe are provided. The first precursor powder, of nominal stoichiometry CaCuO{sub x}, is a solution-synthesized mixture of Ca{sub 0.45}Cu{sub 0.55}O{sub 2} and CaO. Using these oxide precursor mixtures, superconducting tapes with well-aligned grains and reproducible critical current densities J{sub c} in the range of 20,000 to 26,000 A/cm{sup 2} at 75 K in self-field after annealing less than 200 hours were obtained. 2 figs.

Closed-Loop Simulation Study of the Ares I Upper Stage Thrust Vector Control Subsystem for Nominal and Failure Scenarios

NASA Technical Reports Server (NTRS)

Chicatelli, Amy; Fulton, Chris; Connolly, Joe; Hunker, Keith

2010-01-01

As a replacement to the current Shuttle, the Ares I rocket and Orion crew module are currently under development by the National Aeronautics and Space Administration (NASA). This new launch vehicle is segmented into major elements, one of which is the Upper Stage (US). The US is further broken down into subsystems, one of which is the Thrust Vector Control (TVC) subsystem which gimbals the US rocket nozzle. Nominal and off-nominal simulations for the US TVC subsystem are needed in order to support the development of software used for control systems and diagnostics. In addition, a clear and complete understanding of the effect of off-nominal conditions on the vehicle flight dynamics is desired. To achieve these goals, a simulation of the US TVC subsystem combined with the Ares I vehicle as developed. This closed-loop dynamic model was created using Matlab s Simulink and a modified version of a vehicle simulation, MAVERIC, which is currently used in the Ares I project and was developed by the Marshall Space Flight Center (MSFC). For this report, the effects on the flight trajectory of the Ares I vehicle are investigated after failures are injected into the US TVC subsystem. The comparisons of the off-nominal conditions observed in the US TVC subsystem with those of the Ares I vehicle flight dynamics are of particular interest.

5 CFR 370.109 - Agency plans.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS INFORMATION TECHNOLOGY EXCHANGE... organization or self-nomination, to include endorsement by their respective supervisor; (3) Forward nominations... extent to which the employee's current competencies and skills are being utilized in the agency; (ii) The...

Power Peaking Effect of OTTO Fuel Scheme Pebble Bed Reactor

NASA Astrophysics Data System (ADS)

Setiadipura, T.; Suwoto; Zuhair; Bakhri, S.; Sunaryo, G. R.

2018-02-01

Pebble Bed Reactor (PBR) type of Hight Temperature Gas-cooled Reactor (HTGR) is a very interesting nuclear reactor design to fulfill the growing electricity and heat demand with a superior passive safety features. Effort to introduce the PBR design to the market can be strengthen by simplifying its system with the Once-through-then-out (OTTO) cycle PBR in which the pebble fuel only pass the core once. Important challenge in the OTTO fuel scheme is the power peaking effect which limit the maximum nominal power or burnup of the design. Parametric survey is perform in this study to investigate the contribution of different design parameters to power peaking effect of OTTO cycle PBR. PEBBED code is utilized in this study to perform the equilibrium PBR core analysis for different design parameter and fuel scheme. The parameters include its core diameter, height-per-diameter (H/D), power density, and core nominal power. Results of this study show that diameter and H/D effectsare stronger compare to the power density and nominal core power. Results of this study might become an importance guidance for design optimization of OTTO fuel scheme PBR.

Plasmonic behaviour of sputtered Au nanoisland arrays

NASA Astrophysics Data System (ADS)

Tvarožek, V.; Szabó, O.; Novotný, I.; Kováčová, S.; Škriniarová, J.; Šutta, P.

2017-02-01

The specificity of the formation of Au sputtered nanoisland arrays (NIA) on a glass substrate or on a ZnO thin film doped by Ga is demonstrated. Statistical analysis of morphology images (SEM, AFM) exhibited the Log-normal distribution of the size (area) of nanoislands-their modus AM varied from 8 to 328 nm2 depending on the sputtering power density, which determined the nominal thicknesses in the range of 2-8 nm. Preferential polycrystalline texture (111) of Au NIA increased with the power density and after annealing. Transverse localised surface plasmonic resonance (LSPR; evaluated by transmission UV-vis spectroscopy) showed the red shift of the extinction peaks (Δl ≤ 100 nm) with an increase of the nominal thickness, and the blue shift (Δλ ≤ -65 nm) after annealing of Au NIA. The plasmonic behaviour of Au NIA was described by modification of a size-scaling universal model using the nominal thin film thickness as a technological scaling parameter. Sputtering of a Ti intermediate adhesive ultrathin film between the glass substrate and gold improves the adhesion of Au nanoislands as well as supporting the formation of more defined Au NIA structures of smaller dimensions.

77 FR 47826 - Inland Waterways Users Board; Request for Nominations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-10

... above commodity categories. d. Nomination. Reflecting preceding selection criteria, the current.... Mark R. Pointon, (703) 428-6438. SUPPLEMENTARY INFORMATION: The selection, service, and appointment of... substance of those provisions is as follows: a. Selection. Representative organizations are to be selected...

Detecting grouting quality of tendon ducts using the impact-echo method

NASA Astrophysics Data System (ADS)

Qu, Guangzhen; Sun, Min; Zhou, Guangli

2018-06-01

The performance, durability and safety of prestressed concrete bridge were directly affected by the compaction of prestressed pipe. However, the pipe was hidden in the beam, and its grouting density was difficult to detect. The paper had modified three different status of gouting quality through making test model. After that, the impact-Echo method was adopted to detect the grouting quality of tendon ducts, the study was sunmmarized as follow. If the reflect time of slab bottom and nominal thickness of slab increased, the degree of density will increase; testing from half-hole of web, the reflect time and nominal thickness of slab was biggest. At the same time, the reflect time of compacted and uncompacted tendon ducts were mainly. At last, the method was verified by the engineering project, which provided reference value.

Friendship Satisfaction in Children with Autism Spectrum Disorder and Nominated Friends.

PubMed

Petrina, Neysa; Carter, Mark; Stephenson, Jennifer; Sweller, Naomi

2017-02-01

The current study examined the level of friendship satisfaction of children with autism spectrum disorder (ASD) and their nominated friends (with and without diagnosis of ASD). A total of 77 target children with ASD and friends from 49 nominated friendships participated in the study. Relatively high levels of friendship satisfaction were reported by both target children and their nominated friends with no overall difference between dyads involving typically developing friends and friends with ASD. Analysis at the individual dyad level showed a high level of agreement on the reported level of satisfaction across the target participants and their friends. Limitations and directions for future research are presented.

Effects of the high-density lipoprotein mimetic agent CER-001 on coronary atherosclerosis in patients with acute coronary syndromes: a randomized trial.

PubMed

Tardif, Jean-Claude; Ballantyne, Christie M; Barter, Philip; Dasseux, Jean-Louis; Fayad, Zahi A; Guertin, Marie-Claude; Kastelein, John J P; Keyserling, Constance; Klepp, Heather; Koenig, Wolfgang; L'Allier, Philippe L; Lespérance, Jacques; Lüscher, Thomas F; Paolini, John F; Tawakol, Ahmed; Waters, David D

2014-12-07

High-density lipoproteins (HDLs) have several potentially protective vascular effects. Most clinical studies of therapies targeting HDL have failed to show benefits vs. placebo. To investigate the effects of an HDL-mimetic agent on atherosclerosis by intravascular ultrasonography (IVUS) and quantitative coronary angiography (QCA). A prospective, double-blinded, randomized trial was conducted at 51 centres in the USA, the Netherlands, Canada, and France. Intravascular ultrasonography and QCA were performed to assess coronary atherosclerosis at baseline and 3 (2-5) weeks after the last study infusion. Five hundred and seven patients were randomized; 417 and 461 had paired IVUS and QCA measurements, respectively. Patients were randomized to receive 6 weekly infusions of placebo, 3 mg/kg, 6 mg/kg, or 12 mg/kg CER-001. The primary efficacy parameter was the nominal change in the total atheroma volume. Nominal changes in per cent atheroma volume on IVUS and coronary scores on QCA were also pre-specified endpoints. The nominal change in the total atheroma volume (adjusted means) was -2.71, -3.13, -1.50, and -3.05 mm(3) with placebo, CER-001 3 mg/kg, 6 mg/kg, and 12 mg/kg, respectively (primary analysis of 12 mg/kg vs. placebo: P = 0.81). There was also no difference among groups for the nominal change in per cent atheroma volume (0.02, -0.02, 0.01, and 0.19%; nominal P = 0.53 for 12 mg/kg vs. placebo). Change in the coronary artery score was -0.022, -0.036, -0.022, and -0.015 mm (nominal P = 0.25, 0.99, 0.55), and change in the cumulative coronary stenosis score was -0.51, 2.65, 0.71, and -0.77% (compared with placebo, nominal P = 0.85 for 12 mg/kg and nominal P = 0.01 for 3 mg/kg). The number of patients with major cardiovascular events was 10 (8.3%), 16 (13.3%), 17 (13.7%), and 12 (9.8%) in the four groups. CER-001 infusions did not reduce coronary atherosclerosis on IVUS and QCA when compared with placebo. Whether CER-001 administered in other regimens or to other populations could favourably affect atherosclerosis must await further study. Name of the trial registry: Clinicaltrials.gov; Registry's URL: http://clinicaltrials.gov/ct2/show/NCT01201837?term=cer-001&rank=2; NCT01201837. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Cardiology.

Evaluation of high-energy lithium thionyl chloride primary cells

NASA Technical Reports Server (NTRS)

Frank, H. A.

1980-01-01

An advanced commercial primary lithium cell (LiSoCl2) was evaluated in order to establish baseline data for improved lithium batteries for aerospace applications. The cell tested had nominal capacity of 6 Ah. Maximum energy density at low rates (less than C/30, where C is the cell capacity in amp-hrs and 30 corresponds to a 30 hr discharge time) was found to be near 300 Wh/kg. An equation which predicts the operating voltage of these cells as a function of current and state of charge is presented. Heat generation rates of these cells were determined as a function of current in a calorimeter. It was found that heat rates could be theoretically predicted with some degree of accuracy at currents less than 1 amp or the C/6 rate. No explosions were observed in the cells during the condition of overdischarge or reversal nor during high rate discharge. It was found, however, that the cells can vent when overdischarge currents are greater than C/30 and when discharge rates are greater than 1.5C.

The roles of word-form frequency and phonological neighbourhood density in the acquisition of Lithuanian noun morphology.

PubMed

Savičiūtė, Eglė; Ambridge, Ben; Pine, Julian M

2018-05-01

Four- and five-year-old children took part in an elicited familiar and novel Lithuanian noun production task to test predictions of input-based accounts of the acquisition of inflectional morphology. Two major findings emerged. First, as predicted by input-based accounts, correct production rates were correlated with the input frequency of the target form, and with the phonological neighbourhood density of the noun. Second, the error patterns were not compatible with the systematic substitution of target forms by either (a) the most frequent form of that noun or (b) a single morphosyntactic default form, as might be predicted by naive versions of a constructivist and generativist account, respectively. Rather, most errors reflected near-miss substitutions of singular for plural, masculine for feminine, or nominative/accusative for a less frequent case. Together, these findings provide support for an input-based approach to morphological acquisition, but are not adequately explained by any single account in its current form.

Supersonic Flight Dynamics Test 1 - Post-Flight Assessment of Simulation Performance

NASA Technical Reports Server (NTRS)

Dutta, Soumyo; Bowes, Angela L.; Striepe, Scott A.; Davis, Jody L.; Queen, Eric M.; Blood, Eric M.; Ivanov, Mark C.

2015-01-01

NASA's Low Density Supersonic Decelerator (LDSD) project conducted its first Supersonic Flight Dynamics Test (SFDT-1) on June 28, 2014. Program to Optimize Simulated Trajectories II (POST2) was one of the flight dynamics codes used to simulate and predict the flight performance and Monte Carlo analysis was used to characterize the potential flight conditions experienced by the test vehicle. This paper compares the simulation predictions with the reconstructed trajectory of SFDT-1. Additionally, off-nominal conditions seen during flight are modeled in post-flight simulations to find the primary contributors that reconcile the simulation with flight data. The results of these analyses are beneficial for the pre-flight simulation and targeting of the follow-on SFDT flights currently scheduled for summer 2015.

Influence of iridium doping in MgB2 superconducting wires

NASA Astrophysics Data System (ADS)

Grivel, J.-C.

2018-04-01

MgB2 wires with iridium doping were manufactured using the in-situ technique in a composite Cu-Nb sheath. Reaction was performed at 700 °C, 800 °C or 900 °C for 1 h in argon atmosphere. A maximum of about 1.5 at.% Ir replaces Mg in MgB2. The superconducting transition temperature is slightly lowered by Ir doping. The formation of IrMg3 and IrMg4 secondary phase particles is evidenced, especially for a nominal stoichiometry with 2.0 at.% Ir doping. The critical current density and accommodation field of the wires are strongly dependent on the Ir content and are generally weakened in the presence of Ir, although the effect is less pronounced at lower temperatures.

Measurements of LGS, LGN, and LGT thermal coefficients of expansion and density.

PubMed

Malocha, Donald C; François-Saint-Cyr, Hugues; Richardson, Kathleen; Helmbold, Robert

2002-03-01

This paper will report on the measurements of the thermal coefficients of expansion and density of langasite (LGS), langanite (LGN), and langatate (LGT). The data were obtained by fabricating cubes with X, Y, and Z faces with nominal dimensions of 1 cm on a side for each material under test. The techniques used for measurement of density and thermal coefficients of expansion (TCE) of the materials are discussed. The data sets obtained and the extracted coefficients are presented.

SOLVENT HOLD TANK SAMPLE RESULTS FOR MCU-11-1452, MCU-11-1453, MCU-11-1454, MCU-11-1455, MCU-11-1456 AND MCU-11-1457

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

Peters, T.; Fondeur, F.; Fink, S.

Solvent Hold Tank (SHT) samples are sent to Savannah River National Laboratory (SRNL) to examine solvent composition changes over time. On December 5, 2011, Operations personnel delivered six samples from the SHT (MCU-11-1452 through -1457) for analysis. These samples are intended to verify that the solvent is within the specified composition range. The results from the analyses are presented in this document. Samples were received in p-nut vials containing {approx}10 mL each. Once taken into the Shielded Cells, the samples were combined. Samples were removed for analysis by density, semi-volatile organic analysis (SVOA), high performance liquid chromatography (HPLC), and Fourier-Transformmore » Infra-Red spectroscopy (FTIR). Details for the work are contained in a controlled laboratory notebook. Each of the six p-nut vials contained a single phase, with no apparent solids contamination or cloudiness. Table 1 contains the results of the analyses for the combined samples. A duplicate density measurement of the organic phase gave a result of 0.844 g/mL (1.2% residual standard deviation - RSD). Using the density as a starting point, we know that the Isopar{reg_sign} L should be slightly higher than nominal and the other components should be slightly lower than nominal. The results as a whole are internally consistent. All measurements indicate Isopar{reg_sign} L higher than nominal, and Modifier lower than nominal. The extractant result is higher than expected - given the other results, the extractant concentration should be under nominal values. Using the measured density as well as the Isopar{reg_sign} L and Modifier concentrations from the FTIR results, we calculate an extractant concentration of 6888 mg/L. This value is outside the analytical uncertainty of the reported HPLC value. Given the other results, this most likely indicates that the HPLC extractant result was biased high. When compared to the MCU density target of 0.845 g/mL, there is no need to add an Isopar{reg_sign} L trim. However, it is advisable to add sufficient trioctylamine (TOA) to return the solvent composition to within specifications as that component has declined to about 64% the concentration since the last analysis. The TOA measurement was performed twice, so the result is not an analytical aberration. TOA has not been added to the system since the previous quarterly sample in October 2011. As with the previous solvent sample results, these analyses indicate that the solvent does not require Isopar{reg_sign} L trimming at this time. However, addition of TOA is warranted. These findings indicate that the new protocols for solvent monitoring and control are yielding favorable results. Nevertheless, the deviation in the TOA concentration since the last analysis indicates continued periodic (i.e., quarterly) monitoring is recommended.« less

The Effects of Participation Rate on the Internal Reliability of Peer Nomination Measures

ERIC Educational Resources Information Center

Marks, Peter E. L.; Babcock, Ben; Cillessen, Antonius H. N.; Crick, Nicki R.

2013-01-01

Although low participation rates have historically been considered problematic in peer nomination research, some researchers have recently argued that small proportions of participants can, in fact, provide adequate sociometric data. The current study used a classical measurement perspective to investigate the internal reliability (Cronbach's…

An adaptive guidance algorithm for an aerodynamically assisted orbital plane change maneuver. M.S. Thesis

NASA Technical Reports Server (NTRS)

Blissit, J. A.

1986-01-01

Using analysis results from the post trajectory optimization program, an adaptive guidance algorithm is developed to compensate for density, aerodynamic and thrust perturbations during an atmospheric orbital plane change maneuver. The maneuver offers increased mission flexibility along with potential fuel savings for future reentry vehicles. Although designed to guide a proposed NASA Entry Research Vehicle, the algorithm is sufficiently generic for a range of future entry vehicles. The plane change analysis provides insight suggesting a straight-forward algorithm based on an optimized nominal command profile. Bank angle, angle of attack, and engine thrust level, ignition and cutoff times are modulated to adjust the vehicle's trajectory to achieve the desired end-conditions. A performance evaluation of the scheme demonstrates a capability to guide to within 0.05 degrees of the desired plane change and five nautical miles of the desired apogee altitude while maintaining heating constraints. The algorithm is tested under off-nominal conditions of + or -30% density biases, two density profile models, + or -15% aerodynamic uncertainty, and a 33% thrust loss and for various combinations of these conditions.

System and Method for Outlier Detection via Estimating Clusters

NASA Technical Reports Server (NTRS)

Iverson, David J. (Inventor)

2016-01-01

An efficient method and system for real-time or offline analysis of multivariate sensor data for use in anomaly detection, fault detection, and system health monitoring is provided. Models automatically derived from training data, typically nominal system data acquired from sensors in normally operating conditions or from detailed simulations, are used to identify unusual, out of family data samples (outliers) that indicate possible system failure or degradation. Outliers are determined through analyzing a degree of deviation of current system behavior from the models formed from the nominal system data. The deviation of current system behavior is presented as an easy to interpret numerical score along with a measure of the relative contribution of each system parameter to any off-nominal deviation. The techniques described herein may also be used to "clean" the training data.

Scranton 1/sup 0/ x 2/sup 0/ NTMS area: New Jersey, New York, and Pennsylvania. Preliminary basic data report. National Uranium Resource Evaluation Program. Hydrogeochemical and stream sediment reconnaissance

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

Ferguson, R.B.; Tones, P.L.

1978-11-01

Stream sediment and stream water samples were collected from small streams at 980 sites for a nominal density of one site per 18 square kilometers in rural areas. Ground water samples were collected at 1251 sites for a nominal density of one site per 13 square kilometers. Neutron activation analysis results are given for uranium and 16 other elements in sediments, and for uranium and 9 other elements in ground water and surface water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Statistical summaries of data and amore » brief description of results are given. A generalized geologic map and a summary of the geology of the area are included.« less

Ablative material testing for low-pressure, low-cost rocket engines

NASA Technical Reports Server (NTRS)

Richter, G. Paul; Smith, Timothy D.

1995-01-01

The results of an experimental evaluation of ablative materials suitable for the production of light weight, low cost rocket engine combustion chambers and nozzles are presented. Ten individual specimens of four different compositions of silica cloth-reinforced phenolic resin materials were evaluated for comparative erosion in a subscale rocket engine combustion chamber. Gaseous hydrogen and gaseous oxygen were used as propellants, operating at a nominal chamber pressure of 1138 kPa (165 psi) and a nominal mixture ratio (O/F) of 3.3. These conditions were used to thermally simulate operation with RP-1 and liquid oxygen, and achieved a specimen throat gas temperature of approximately 2456 K (4420 R). Two high-density composition materials exhibited high erosion resistance, while two low-density compositions exhibited approximately 6-75 times lower average erosion resistance. The results compare favorably with previous testing by NASA and provide adequate data for selection of ablatives for low pressure, low cost rocket engines.

Investigation of Physical Processes Limiting Plasma Density in DIII--D

NASA Astrophysics Data System (ADS)

Maingi, R.

1996-11-01

Understanding the physical processes which limit operating density is crucial in achieving peak performance in confined plasmas. Studies from many of the world's tokamaks have indicated the existence(M. Greenwald, et al., Nucl. Fusion 28) (1988) 2199 of an operational density limit (Greenwald limit, n^GW_max) which is proportional to the plasma current and independent of heating power. Several theories have reproduced the current dependence, but the lack of a heating power dependence in the data has presented an enigma. This limit impacts the International Thermonuclear Experimental Reactor (ITER) because the nominal operating density for ITER is 1.5 × n^GW_max. In DIII-D, experiments are being conducted to understand the physical processes which limit operating density in H-mode discharges; these processes include X-point MARFE formation, high core recycling and neutral pressure, resistive MHD stability, and core radiative collapse. These processes affect plasma properties, i.e. edge/scrape-off layer conduction and radiation, edge pressure gradient and plasma current density profile, and core radiation, which in turn restrict the accessible density regime. With divertor pumping and D2 pellet fueling, core neutral pressure is reduced and X-point MARFE formation is effectively eliminated. Injection of the largest-sized pellets does cause transient formation of divertor MARFEs which occasionally migrate to the X-point, but these are rapidly extinguished in pumped discharges in the time between pellets. In contrast to Greenwald et al., it is found that the density relaxation time after pellets is largely independent of the density relative to the Greenwald limit. Fourier analysis of Mirnov oscillations indicates the de-stabilization and growth of rotating, tearing-type modes (m/n= 2/1) when the injected pellets cause large density perturbations, and these modes often reduce energy confinement back to L-mode levels. We are examining the mechanisms for de-stabilization of the mode, the primary ones being neo-classical pressure gradient drivers. Discharges with a gradual density increase are often free of large amplitude tearing modes, allowing access to the highest density regimes in which off-axis beam deposition can lead to core radiative collapse, i.e. a central power balance limit. The highest achieved barne was 1.5 × n^GW_max with τ_E/τ_E^JET-DIII-D >= 0.9. The highest density obtained in L-mode discharges was 3 × n^GW_max. Implications of these results for ITER will be discussed.

Voyager 1 Saturn targeting strategy

NASA Technical Reports Server (NTRS)

Cesarone, R. J.

1980-01-01

A trajectory targeting strategy for the Voyager 1 Saturn encounter has been designed to accomodate predicted uncertainties in Titan's ephemeris while maximizing spacecraft safety and science return. The encounter is characterized by a close Titan flyby 18 hours prior to Saturn periapse. Retargeting of the nominal trajectory to account for late updates in Titan's estimated position can disperse the ascending node location, which is nominally situated at a radius of low expected particle density in Saturn's ring plane. The strategy utilizes a floating Titan impact vector magnitude to minimize this dispersion. Encounter trajectory characteristics and optimal tradeoffs are presented.

Prosocial Behavior Moderates the Effects of Aggression on Young Adolescents' Friendships

ERIC Educational Resources Information Center

McDonald, Kristina L.; Wang, Jennifer; Menzer, Melissa M.; Rubin, Kenneth H.; Booth-LaForce, Cathryn

2011-01-01

The current study explored how prosocial behavior may moderate how aggression is related to the features of adolescents' friendships. Young adolescents (N = 910) completed friendship nominations in the fall and spring of their first year of middle school. Behavioral nominations of aggression and prosocial behavior were also collected in the fall.…

User handbook for block IV silicon solar cell modules

NASA Technical Reports Server (NTRS)

Smokler, M. I.

1982-01-01

The essential electrical and mechanical characteristics of block 4 photovoltaic solar cell modules are described. Such module characteristics as power output, nominal operating voltage, current-voltage characteristics, nominal operating cell temperature, and dimensions are tabulated. The limits of the environmental and other stress tests to which the modules are subjected are briefly described.

Misleading University Rankings: Cause and Cure for Discrepancies between Nominal and Attained Weights

ERIC Educational Resources Information Center

Soh, Kaycheng

2013-01-01

Recent research into university ranking methodologies uncovered several methodological problems among the systems currently in vogue. One of these is the discrepancy between the nominal and attained weights. The problem is the summation of unstandardized indicators for the total scores used in ranking. It is demonstrated that weight discrepancy…

Measurement of machine parts dimensions positional deviation with regard to their geometric accuracy

NASA Astrophysics Data System (ADS)

Martemyanov, D. B.; Pshenichnikova, V. V.; Penner, V. A.; Zemtsov, A. E.

2018-04-01

Real surfaces of the parts, obtained with the help of technological processes, are always characterized by deviations from a nominal (regular) form. When analyzing a nominal cylindrical surface or a prismatic component element, the interrelation between current dimensions in various sections and a surface form, as well as surfaces position, can be found.

77 FR 64990 - Pesticide Program Dialogue Committee; Request for Nominations to the Pesticide Program Dialogue...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-24

... candidates, EPA encourages nominations of women and men of all racial and ethnic groups. Vacancies are... the public in general, and may be of particular interest to persons who work in agricultural settings... performance of duties imposed on the Agency by law. The following sectors are represented on the current PPDC...

Field Trial on a Rack-mounted DC Power Supply System with 80-Ah Lithium-ion Batteries

NASA Astrophysics Data System (ADS)

Matsushima, Toshio

Using an industrial lithium-ion battery that has higher energy density than conventional valve-regulated lead-acid batteries, a rack-mounted DC-power-supply system was assembled and tested at a base transceiver station (BTS) offering actual services. A nominal output voltage and maximum output current of the system is 53.5V and 20A, respectively. An 80-Ah lithium-ion battery composed of 13 cells connected in series was applied in the system and maintained in a floating charge method. The DC-power-supply system was installed in a 19-inch power rack in the telecommunications equipment box at BTS. The characteristics of the 80Ah lithium-ion battery, specifications of the DC-power-supply system and field-test results were shown in this paper.

Evaluation of line transect sampling based on remotely sensed data from underwater video

USGS Publications Warehouse

Bergstedt, R.A.; Anderson, D.R.

1990-01-01

We used underwater video in conjunction with the line transect method and a Fourier series estimator to make 13 independent estimates of the density of known populations of bricks lying on the bottom in shallows of Lake Huron. The pooled estimate of density (95.5 bricks per hectare) was close to the true density (89.8 per hectare), and there was no evidence of bias. Confidence intervals for the individual estimates included the true density 85% of the time instead of the nominal 95%. Our results suggest that reliable estimates of the density of objects on a lake bed can be obtained by the use of remote sensing and line transect sampling theory.

Effect of V/III ratio on the surface morphology and electrical properties of m-plane (10 1 bar 0) GaN homoepitaxial layers

NASA Astrophysics Data System (ADS)

Barry, Ousmane I.; Tanaka, Atsushi; Nagamatsu, Kentaro; Bae, Si-Young; Lekhal, Kaddour; Matsushita, Junya; Deki, Manato; Nitta, Shugo; Honda, Yoshio; Amano, Hiroshi

2017-06-01

We have investigated the effect of V/III ratio on the surface morphology, impurity concentration and electrical properties of m-plane (10 1 bar 0) Gallium Nitride (GaN) homoepitaxial layers. Four-sided pyramidal hillocks are observed on the nominally on-axis m-plane GaN films. Hillocks sizes relatively increase by increasing the V/III ratio. All facets of pyramidal hillocks exhibit well-defined step-terrace features. Secondary ion mass spectrometry depth profiles reveal that carbon impurities decrease by increasing the V/III ratio while the lowest oxygen content is found at an optimized V/III ratio of 900. Vertical Schottky barrier diodes fabricated on the m-GaN samples were characterized. Low leakage current densities of the order of 10-10 A/cm2 at -5 V are obtained at the optimum V/III ratio. Oxygen impurities and screw-component dislocations around hillocks are found to have more detrimental impact on the leakage current mechanism.

Superconducting dc Current Limiting Vacuum Circuit Breaker

NASA Astrophysics Data System (ADS)

Alferov, D. F.; Akhmetgareev, M. R.; Budovskii, A. I.; Bunin, R. A.; Voloshin, I. F.; Degtyarenko, P. N.; Yevsin, D. V.; Ivanov, V. P.; Sidorov, V. A.; Fisher, L. M.; Tshai, E. V.

Acircuitofadc superconductingfault current limiter witha direct current circuit-breaker fora nominal current 300A is proposed. It includes the 2G high temperature superconducting (HTS) tapes and the high-speed dc vacuum circuit breaker.Thetestresultsof current-limitingcapacityandrecoverytimeof superconductivityafter currentfaultatvoltage upto3 kV are presented.

Characterization of AlN/AlGaN/GaN:C heterostructures grown on Si(111) using atom probe tomography, secondary ion mass spectrometry, and vertical current-voltage measurements

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

Huber, Martin, E-mail: martin.huberVIH@infineon.com; Daumiller, Ingo; Andreev, Andrei

2016-03-28

Complementary studies of atom probe tomography, secondary ion mass spectrometry, and vertical current-voltage measurements are carried out in order to unravel the influence of C-doping of GaN on the vertical leakage current of AlN/AlGaN/GaN:C heterostructures. A systematic increment of the vertical blocking voltage at a given current density is observed in the structures, when moving from the nominally undoped conditions—corresponding to a residual C-background of ∼10{sup 17 }cm{sup −3}—to a C-content of ∼10{sup 19 }cm{sup −3} in the GaN layer. The value of the vertical blocking voltage saturates for C concentrations higher than ∼10{sup 19 }cm{sup −3}. Atom probe tomography confirms the homogeneitymore » of the GaN:C layers, demonstrating that there is no clustering at C-concentrations as high as 10{sup 20 }cm{sup −3}. It is inferred that the vertical blocking voltage saturation is not likely to be related to C-clustering.« less

Factors Underlying Bursting Behavior in a Network of Cultured Hippocampal Neurons Exposed to Zero Magnesium

PubMed Central

Mangan, Patrick S.; Kapur, Jaideep

2010-01-01

Factors contributing to reduced magnesium-induced neuronal action potential bursting were investigated in primary hippocampal cell culture at high and low culture density. In nominally zero external magnesium medium, pyramidal neurons from high-density cultures produced recurrent spontaneous action potential bursts superimposed on prolonged depolarizations. These bursts were partially attenuated by the NMDA receptor antagonist D-APV. Pharmacological analysis of miniature excitatory postsynaptic currents (EPSCs) revealed 2 components: one sensitive to D-APV and another to the AMPA receptor antagonist DNQX. The components were kinetically distinct. Participation of NMDA receptors in reduced magnesium-induced synaptic events was supported by the localization of the NR1 subunit of the NMDA receptor with the presynaptic vesicular protein synaptophysin. Presynaptically, zero magnesium induced a significant increase in EPSC frequency likely attributable to increased neuronal hyperexcitability induced by reduced membrane surface charge screening. Mean quantal content was significantly increased in zero magnesium. Cells from low-density cultures did not exhibit action potential bursting in zero magnesium but did show increased EPSC frequency. Low-density neurons had less synaptophysin immunofluorescence and fewer active synapses as determined by FM1-43 analysis. These results demonstrate that multiple factors are involved in network bursting. Increased probability of transmitter release presynaptically, enhanced NMDA receptor-mediated excitability postsynaptically, and extent of neuronal interconnectivity contribute to initiation and maintenance of elevated network excitability. PMID:14534286

Prosocial and antisocial children's perceptions of peers' motives for prosocial behaviours.

PubMed

Wardle, Georgina A; Hunter, Simon C; Warden, David

2011-09-01

This study investigated whether peer-nominated prosocial and antisocial children have different perceptions of the motives underlying peers' prosocial actions. Eighty-seven children, aged 10-12 years old, completed peer-nomination measures of social behaviour. On the basis of numbers of social nominations received, a subsample of 51 children (32 who were peer-nominated as 'prosocial', and 18 who were peer-nominated as 'antisocial') then recorded their perceptions of peers' motives for prosocial behaviours. Expressed motives were categorized predominantly into three categories, coinciding with Turiel's (1978) 'moral', 'conventional', and 'personal domains'. Results indicate that children's social reputation is associated with the extent to which they perceive peers' prosocial motives as 'personal' or 'moral', with more prosocial children attributing moral motives, and more antisocial children attributing personal motives. Although traditionally Turiel's domain theory has been used to understand 'antisocial' children's behaviour, the current findings suggest that 'prosocial' children's behaviour may also be related to domains of judgment. ©2010 The British Psychological Society.

Transmission Loss Calculation using A and B Loss Coefficients in Dynamic Economic Dispatch Problem

NASA Astrophysics Data System (ADS)

Jethmalani, C. H. Ram; Dumpa, Poornima; Simon, Sishaj P.; Sundareswaran, K.

2016-04-01

This paper analyzes the performance of A-loss coefficients while evaluating transmission losses in a Dynamic Economic Dispatch (DED) Problem. The performance analysis is carried out by comparing the losses computed using nominal A loss coefficients and nominal B loss coefficients in reference with load flow solution obtained by standard Newton-Raphson (NR) method. Density based clustering method based on connected regions with sufficiently high density (DBSCAN) is employed in identifying the best regions of A and B loss coefficients. Based on the results obtained through cluster analysis, a novel approach in improving the accuracy of network loss calculation is proposed. Here, based on the change in per unit load values between the load intervals, loss coefficients are updated for calculating the transmission losses. The proposed algorithm is tested and validated on IEEE 6 bus system, IEEE 14 bus, system IEEE 30 bus system and IEEE 118 bus system. All simulations are carried out using SCILAB 5.4 (www.scilab.org) which is an open source software.

Communications Blackout Prediction for Atmospheric Entry of Mars Science Laboratory

NASA Technical Reports Server (NTRS)

Morabito, David; Edquist, Karl

2005-01-01

When a supersonic spacecraft enters a planetary atmosphere with v >> v(sub sound), a shock layer forms in the front of the body. An ionized sheath of plasma develops around the spacecraft, which results from the ionization of the atmospheric constituents as they are compressed and heated by the shock or heated within the boundary layer next to the surface. When the electron density surrounding the spacecraft becomes sufficiently high, communications can be disrupted (attenuation/blackout). During Mars Science Laboratory's (MSL's) atmospheric entry there will likely be a communication outage due to charged particles on the order of 60 to 100 seconds using a UHF link frequency looking out the shoulders of the wake region to orbiting relay asset. A UHF link looking out the base region would experience a shorter duration blackout, about 35 seconds for the stressed trajectory and possibly no blackout for the nominal trajectory. There is very little likelihood of a communications outage using X-band (however, X-band is not currently planned to be used during peak electron density phase of EDL).

Self-diffusion in MgO--a density functional study.

PubMed

Runevall, Odd; Sandberg, Nils

2011-08-31

Density functional theory calculations have been performed to study self-diffusion in magnesium oxide, a model material for a wide range of ionic compounds. Formation energies and entropies of Schottky defects and divacancies were obtained by means of total energy and phonon calculations in supercell configurations. Transition state theory was used to estimate defect migration rates, with migration energies taken from static calculations, and the corresponding frequency factors estimated from the phonon spectrum. In all static calculations we corrected for image effects using either a multipole expansion or an extrapolation to the low concentration limit. It is shown that both methods give similar results. The results for self-diffusion of Mg and O confirm the previously established picture, namely that in materials of nominal purity, Mg diffuses extrinsically by a single vacancy mechanism, while O diffuses intrinsically by a divacancy mechanism. Quantitatively, the current results are in very good agreement with experiments concerning O diffusion, while for Mg the absolute diffusion rate is generally underestimated by a factor of 5-10. The reason for this discrepancy is discussed.

SU-E-J-152: Evaluation of TrueBeam OBI V. 1.5 CBCT Performance in An Adaptive RT Environment

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

Gardner, S; Studenski, M; Giaddui, T

2014-06-01

Purpose: To evaluate the image quality and imaging dose of the Varian TrueBeam OBIv.1.5 CBCT system in a clinical adaptive radiation therapy environment, simulated by changing phantom thickness. Methods: Various OBI CBCT protocols(Head, Pelvis, Thorax, Spotlight) were used to acquire images of Catphan504 phantom(nominal phantom thickness and 10 cm additional phantom thickness). The images were analyzed for low contrast detectability(CNR), uniformity(UI), and HU sensitivity. These results were compared to the same image sets for planning CT(pCT)(GE LightSpeed 16- slice). Imaging dose measurements were performed with Gafchromic XRQA2 film for various OBI protocols (Pelvis, Thorax, Spotlight) in a pelvic-sized phantom(nominal thicknessmore » and 4cm additional thickness). Dose measurements were acquired in the interior and at the surface of the phantom. Results: The nominal CNR[additional thickness CNR] for OBI was—Pelvis:1.45[0.81],Thorax:0.86[0.48], Spotlight:0.67[0.39],Head:0.28 [0.10]. The nominal CNR[additional thickness CNR] for pCT was— Pelvis:0.87[0.41],Head:0.60[0.22]. The nominal UI[additional thickness UI] for OBI was—Pelvis:11.5[24.1],Thorax:17.0[20.6], Spotlight:23.2[23.2], Head:15.6[59.9]. The nominal UI[additional thickness UI] for pCT was— Pelvis:9.2[8.6],Head:2.1[2.9]. The HU difference(averaged over all material inserts) between nominal and additional thickness scans for OBI: 8.26HU(Pelvis), 33.39HU(Thorax), 178.98HU(Head), 108.20HU (Spotlight); for pCT: 16.00HU(Pelvis), 19.85HU(Head). Uncertainties in electron density were calculated based on HU values with varying phantom thickness. Average electron-density deviations (ρ(water)=1)for GE-Pelvis, GE-Head, OBI-Pelvis, OBI-Thorax, OBI-Spotlight, and OBI-Head were: 0.0182, 0.0180, 0.0058, 0.0478, 0.2750, and 0.3115, respectively.The average phantom interior dose was(OBI-nominal):2.35cGy(Pelvis), 0.60cGy(Thorax), 1.87cGy(Spotlight); OBI-increased thickness: 1.77cGy(Pelvis), 0.43cGy(Thorax), 1.53cGy (Spotlight). Average surface dose(OBI-nominal): 2.29cGy(Pelvis), 0.56cGy(Thorax), 1.79cGy (Spotlight); OBI-increased thickness: 1.94cGy(Pelvis), 0.48cGy(Thorax), 1.47cGy (Spotlight). Conclusion: The OBI-Pelvis protocol offered comparable CNR and HU constancy to pCT for each geometry; other protocols, particularly Spotlight and Head, exhibited lower HU constancy and CNR. The uniformity of pCT was superior to OBI for all protocols. CNR and UI were degraded for both systems/scan types with increased thickness. The OBI interior dose decreased by approximately 30% with additional thickness. This work was funded, in part, under a grant with the Pennsylvania Department of Health. The Department of Health specifically declaims responsibility for any analyses, interpretations, or conclusions.« less

Comparison of dislocation density tensor fields derived from discrete dislocation dynamics and crystal plasticity simulations of torsion

DOE PAGES

Jones, Reese E.; Zimmerman, Jonathan A.; Po, Giacomo; ...

2016-02-01

Accurate simulation of the plastic deformation of ductile metals is important to the design of structures and components to performance and failure criteria. Many techniques exist that address the length scales relevant to deformation processes, including dislocation dynamics (DD), which models the interaction and evolution of discrete dislocation line segments, and crystal plasticity (CP), which incorporates the crystalline nature and restricted motion of dislocations into a higher scale continuous field framework. While these two methods are conceptually related, there have been only nominal efforts focused at the global material response that use DD-generated information to enhance the fidelity of CPmore » models. To ascertain to what degree the predictions of CP are consistent with those of DD, we compare their global and microstructural response in a number of deformation modes. After using nominally homogeneous compression and shear deformation dislocation dynamics simulations to calibrate crystal plasticity ow rule parameters, we compare not only the system-level stress-strain response of prismatic wires in torsion but also the resulting geometrically necessary dislocation density fields. To establish a connection between explicit description of dislocations and the continuum assumed with crystal plasticity simulations we ascertain the minimum length-scale at which meaningful dislocation density fields appear. Furthermore, our results show that, for the case of torsion, that the two material models can produce comparable spatial dislocation density distributions.« less

A superconducting direct-current limiter with a power of up to 8 MVA

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

Fisher, L. M.; Alferov, D. F., E-mail: DFAlferov@niitfa.ru; Akhmetgareev, M. R.

2016-12-15

A resistive switching superconducting fault current limiter (SFCL) for DC networks with a nominal voltage of 3.5 kV and a nominal current of 2 kA was developed, produced, and tested. The SFCL has two main units—an assembly of superconducting modules and a high-speed vacuum circuit breaker. The assembly of superconducting modules consists of nine (3 × 3) parallel–series connected modules. Each module contains four parallel-connected 2G high-temperature superconducting (HTS) tapes. The results of SFCL tests in the short-circuit emulation mode with a maximum current rise rate of 1300 A/ms are presented. The SFCL is capable of limiting the current atmore » a level of 7 kA and break it 8 ms after the current-limiting mode begins. The average temperature of HTS tapes during the current-limiting mode increases to 210 K. After the current is interrupted, the superconductivity recovery time does not exceed 1 s.« less

A superconducting direct-current limiter with a power of up to 8 MVA

NASA Astrophysics Data System (ADS)

Fisher, L. M.; Alferov, D. F.; Akhmetgareev, M. R.; Budovskii, A. I.; Evsin, D. V.; Voloshin, I. F.; Kalinov, A. V.

2016-12-01

A resistive switching superconducting fault current limiter (SFCL) for DC networks with a nominal voltage of 3.5 kV and a nominal current of 2 kA was developed, produced, and tested. The SFCL has two main units—an assembly of superconducting modules and a high-speed vacuum circuit breaker. The assembly of superconducting modules consists of nine (3 × 3) parallel-series connected modules. Each module contains four parallel-connected 2G high-temperature superconducting (HTS) tapes. The results of SFCL tests in the short-circuit emulation mode with a maximum current rise rate of 1300 A/ms are presented. The SFCL is capable of limiting the current at a level of 7 kA and break it 8 ms after the current-limiting mode begins. The average temperature of HTS tapes during the current-limiting mode increases to 210 K. After the current is interrupted, the superconductivity recovery time does not exceed 1 s.

Analysis and design of continuous class-E power amplifier at sub-nominal condition

NASA Astrophysics Data System (ADS)

Chen, Peng; Yang, Kai; Zhang, Tianliang

2017-12-01

The continuous class-E power amplifier at sub-nominal condition is proposed in this paper. The class-E power amplifier at continuous mode means it can be high efficient on a series matching networks while at sub-nominal condition means it only requires the zero-voltage-switching condition. Comparing with the classical class-E power amplifier, the proposed design method releases two additional design freedoms, which increase the class-E power amplifier's design flexibility. Also, the proposed continuous class-E power amplifier at sub-nominal condition can perform high efficiency over a broad bandwidth. The performance study of the continuous class-E power amplifier at sub-nominal condition is derived and the design procedure is summarised. The normalised switch voltage and current waveforms are investigated. Furthermore, the influences of different sub-nominal conditions on the power losses of the switch-on resistor and the output power capability are also discussed. A broadband continuous class-E power amplifier based on a Gallium Nitride (GaN) transistor is designed and testified to verify the proposed design methodology. The measurement results show, it can deliver 10-15 W output power with 64-73% power-added efficiency over 1.4-2.8 GHz.

Towards graphane field emitters

PubMed Central

Ding, Shuyi; Li, Chi; Zhou, Yanhuai; Collins, Clare M.; Kang, Moon H.; Parmee, Richard J.; Zhang, Xiaobing; Milne, William I.; Wang, Baoping

2015-01-01

We report on the improved field emission performance of graphene foam (GF) following transient exposure to hydrogen plasma. The enhanced field emission mechanism associated with hydrogenation has been investigated using Fourier transform infrared spectroscopy, plasma spectrophotometry, Raman spectroscopy, and scanning electron microscopy. The observed enhanced electron emissionhas been attributed to an increase in the areal density of lattice defects and the formation of a partially hydrogenated, graphane-like material. The treated GF emitter demonstrated a much reduced macroscopic turn-on field (2.5 V μm–1), with an increased maximum current density from 0.21 mA cm–2 (pristine) to 8.27 mA cm–2 (treated). The treated GFs vertically orientated protrusions, after plasma etching, effectively increased the local electric field resulting in a 2.2-fold reduction in the turn-on electric field. The observed enhancement is further attributed to hydrogenation and the subsequent formation of a partially hydrogenated structured 2D material, which advantageously shifts the emitter work function. Alongside augmentation of the nominal crystallite size of the graphitic superstructure, surface bound species are believed to play a key role in the enhanced emission. The hydrogen plasma treatment was also noted to increase the emission spatial uniformity, with an approximate four times reduction in the per unit area variation in emission current density. Our findings suggest that plasma treatments, and particularly hydrogen and hydrogen-containing precursors, may provide an efficient, simple, and low cost means of realizing enhanced nanocarbon-based field emission devices via the engineered degradation of the nascent lattice, and adjustment of the surface work function. PMID:28066543

Air Traffic Controllers' Control Strategies in the Terminal Area Under Off-Nominal Conditions

NASA Technical Reports Server (NTRS)

Martin, Lynne; Mercer, Joey; Callantine, Todd; Kupfer, Michael; Cabrall, Christopher

2012-01-01

A human-in-the-loop simulation investigated the robustness of a schedule-based terminal-area air traffic management concept, and its supporting controller tools, to off-nominal events - events that led to situations in which runway arrival schedules required adjustments and controllers could no longer use speed control alone to impose the necessary delays. The main research question was exploratory: to assess whether controllers could safely resolve and control the traffic during off-nominal events. A focus was the role of the supervisor - how he managed the schedules, how he assisted the controllers, what strategies he used, and which combinations of tools he used. Observations and questionnaire responses revealed supervisor strategies for resolving events followed a similar pattern: a standard approach specific to each type of event often resolved to a smooth conclusion. However, due to the range of factors influencing the event (e.g., environmental conditions, aircraft density on the schedule, etc.), sometimes the plan required revision and actions had a wide-ranging effect.

Field-aligned Currents at Mercury and Implications for Crustal Electrical Conductivity

NASA Astrophysics Data System (ADS)

Anderson, B. J.; Johnson, C. L.; Korth, H.; Winslow, R. M.; Slavin, J. A.; Solomon, S. C.; McNutt, R. L., Jr.

2013-12-01

Magnetic field data acquired in orbit about Mercury by the Magnetometer on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft are used to identify signatures of steady-state field-aligned or Birkeland currents in the northern polar region. These signatures allow us to determine the distribution, area, and total current typically flowing toward and away from the planet and closing at low altitudes. Results reveal that current flows downward on the dawn side and upward on the dusk side, a pattern corresponding to the Region-1 current system at Earth. Typical current densities are 10 to 20 nA/m2. The total current ranges from 10 kA under magnetically calm conditions to nearly 40 kA during disturbed periods. Both the current density and the total current are approximately two orders of magnitude lower than at Earth. The electric potential, consistent with dayside magnetopause magnetic reconnection, is estimated to be ~30 kV under typical conditions, implying that the net resistance to closure of the Birkeland currents is on the order of 1 ohm. At Earth this resistance is typically 0.02 ohms, and if the height-integrated low-altitude conductance were the same, the resistance at Mercury would be even lower than at Earth, ~0.01 ohms. The comparatively low current observed and the estimated high resistance are consistent with expectations that current closure at Mercury is markedly different than at Earth. We solve for the potential implied by the observed currents given closure through the planet. We consider crustal and mantle conductances consistent with experimental results for olivine, and we use a nominal present-day radial temperature profile for Mercury. Net potentials comparable to 30 kV require that the current closes radially through the crust and horizontally through the higher-conductivity mantle at depths of 50 to 400 km. The crust accounts for nearly all of the resistance to current flow, and the results are consistent with a crustal conductivity on the order of 10-8 S/m.

7 CFR 945.20 - Establishment and membership.

Code of Federal Regulations, 2013 CFR

2013-01-01

... established consisting of eight members, of whom four shall currently be producers of potatoes for the fresh... handled by him during the portion of the then current season preceding his nomination. (c) Each person...

Laser machining wood composites

Treesearch

Vladimir Barnekov; Henry A. Huber; Charles W. McMillin

1989-01-01

This practical, nonstatistical experiment using commercial equipment demonstrated that nominal 3/4-inch compositep anelsf or furniture consisting of a particleboard core,h igh density melamine crossbands, and walnut veneer face plies can be cut with a carbon dioxide/airjet-assisted laser to produce surfaces with minimal nonparallelism and char compared to previous...

NEW CONSTRAINTS ON THE ABUNDANCES OF SILICATE AND OXIDE STARDUST FROM SUPERNOVAE IN THE ACFER 094 METEORITE

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

Hoppe, Peter; Leitner, Jan; Kodolányi, János, E-mail: peter.hoppe@mpic.de

2015-07-20

We studied about 5000 μm{sup 2} of fine-grained matrix material in the Acfer 094 meteorite by high-resolution (nominal 50 nm) NanoSIMS ion imaging for the presence of O-rich presolar (stardust) grains. This approach permits identifying presolar grains down to <100 nm in size, compared to >150 nm in lower-resolution (nominal 100 nm) ion imaging surveys. The number density of identified presolar grains is a about a factor of two to three higher than what was found by lower-resolution ion imaging studies. The abundances of grains of O isotope Group 3 and 4 are higher than previously found. None of themore » presolar grains shows the strong enrichments in {sup 16}O expected from model predictions for the majority of supernova (SN) grains. Other potential O-rich SN grains, the Group 4 and some of the Group 3 grains, make up 33% by number and 19% by mass. This is clearly higher than the ∼10% (by number) inferred before and the 5% (by mass) estimated by a model for stellar dust in the interstellar medium. Our work shows that O-rich SN grains might be more abundant among the population of presolar grains in primitive solar system materials than currently thought, even without the {sup 16}O-rich grains as predominantly expected from SN models.« less

A peer-nomination assessment of electronic forms of aggression and victimization.

PubMed

Badaly, Daryaneh; Duong, Mylien T; Ross, Alexandra C; Schwartz, David

2015-10-01

The perpetration and receipt of electronic aggression have largely been assessed with self-report questionnaires. Using a sample of 573 adolescents, the current study compared the psychometric properties of a peer-nomination measure of electronic aggression and victimization to the more widely used self-report approach. Estimates of the reliability, stability, and concordance of peer- and self-report assessments were adequate, mirroring those from research on aggressive exchanges in school. Analyses of validity and utility revealed that peer-nominations, compared to self-reports, provide overlapping and distinct information on adolescents' social, emotional, and academic adjustment. Overall, these findings provide evidence that peer-nominations are a reliable, valid, and useful means for measuring electronic aggression and victimization. Future work will benefit from their incorporation into multi-method assessments. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Aircraft Capability Management

NASA Technical Reports Server (NTRS)

Mumaw, Randy; Feary, Mike

2018-01-01

This presentation presents an overview of work performed at NASA Ames Research Center in 2017. The work concerns the analysis of current aircraft system management displays, and the initial development of an interface for providing information about aircraft system status. The new interface proposes a shift away from current aircraft system alerting interfaces that report the status of physical components, and towards displaying the implications of degradations on mission capability. The proposed interface describes these component failures in terms of operational consequences of aircraft system degradations. The research activity was an effort to examine the utility of different representations of complex systems and operating environments to support real-time decision making of off-nominal situations. A specific focus was to develop representations that provide better integrated information to allow pilots to more easily reason about the operational consequences of the off-nominal situations. The work is also seen as a pathway to autonomy, as information is integrated and understood in a form that automated responses could be developed for the off-nominal situations in the future.

Inkjet-based adaptive planarization (Conference Presentation)

NASA Astrophysics Data System (ADS)

Singhal, Shrawan; Grigas, Michelle M.; Khusnatdinov, Niyaz; Sreenivasan, Srinivasan V.

2017-03-01

Planarization is a critical unit step in the lithography process because it enables patterning of surfaces with versatile pattern density without compromising on the stringent planarity and depth-of-focus requirements. In addition to nanoscale pattern density variation, parasitics such as pre-existing wafer topography, can corrupt the desired process output after planarization. The topography of any surface can be classified in three broad categories, depending upon the amplitude and spatial wavelength of the same [1], [2]: (i) nominal shape, (ii) nanotopography and (iii) roughness. The nominal shape is given by the largest spatial wavelengths, typically < 20mm. For spatial length scales of 1-20mm, height variations at this spatial wavelength range are classified as nanotopography. Roughness usually has lower spatial wavelengths. While the nominal shape of a substrate surface is usually decided by the nature of wafer preparation and the tooling and chucking infrastructure used in the same, roughness is usually mitigated by standard polishing techniques. It is the intermediate nanotopography that is probably the most critical surface topography parameter. This is because most traditional polishing techniques cannot selectively address pre-existing substrate topography, without introducing a parasitic signature at the scale of nanotopography. Moreover, fields with pattern density variation typically also have length scales that are commensurate with nanotopography. It is thus instructive to summarize existing planarization technology to understand current limitations. Spin on Glass and Etch back is one technique used for micron scale device manufacturing [3]. As the name implies, a glass dielectric is spin-coated on the substrate followed by etching in a chemistry that ensures equal etching rates for both the sacrificial glass and the underlying film or substrate material. Photoresists may also be used instead of glass. However, the global planarity that can be achieved by this technique is limited. Also, planarization over a large isolated topographical feature has been studied for the reverse-tone Jet-and-Flash Imprint Lithography process, also known as JFIL-R [4]. This relies on surface tension and capillary effects to smoothen a spin-coated Si containing film that can be etched to obtain a smooth profile. To meet the stringent requirement of planarity in submicron device technologies Chemical Mechanical Planarization (CMP) is the most widely used planarization technology [5], [6]. It uses a combination of abrasive laden chemical slurry and a mechanical pad for achieving planar profiles. The biggest concern with CMP is the dependence of material removal rate on the pattern density of material, leading to the formation of a step between the high density and low-density. The step shows up as a long-range thickness variation in the planarized film, similar in scale to pre-existing substrate topography that should have been polished away. Preventive techniques like dummy fill and patterned resist can be used to reduce the variation in pattern density. These techniques increase the complexity of the planarization process and significantly limit the device design flexibility. Contact Planarization (CP) has also been reported as an alternative to the CMP processing [7], [8]. A substrate is spin coated with a photo curable material and pre baked to remove residual solvent. An ultra-flat surface or an optical flat is pressed on the spin-coated wafer. The material is forced to reflow. Pressure is used to spread out material evenly and achieve global planarization. The substrate is then exposed to UV radiation to harden the photo curable material. Although attractive, this process is not adaptive as it does not account for differences in surface topography of the wafer and the optical flat, nor can it address all the parasitics that arise during the process itself. The optical flat leads to undesirable planarization of even the substrate nominal shape and nanotopography, which corrupts the final film thickness profile. Hence, it becomes extremely difficult to eliminate this signature to a desirable extent without introducing other parasitic signatures. An example of this is shown in Figure 1. In this paper, a novel adaptive planarization process has been presented that potentially addresses the problems associated with planarization of varying pattern density, even in the presence of pre-existing substrate topography [9]. This process is called Inkjet-enabled Adaptive Planarization (IAP). The IAP process uses an inverse optimization scheme, built around a validated fluid mechanics-based forward model [10], that takes the pre-existing substrate topography and pattern layout as inputs. It then generates an inkjet drop pattern with a material distribution that is correlated with the desired planarization film profile. This allows a contiguous film to be formed with the desired thickness variation to cater to the topography and any parasitic signatures caused by the pattern layout. This film is formed by the coercing action of a compliant superstrate, which forces the drops to spread and merge and eliminates any bubble trapping. Then, the film is cured using blanket UV exposure and the superstrate separated to reveal the desired planarized film. The use of an inverse optimization algorithm allows substrate topography to be addressed adaptively. In other words, the algorithm can generate a drop pattern that does not disturb the pre-existing substrate topography substantially, but only caters to the pattern density variation. This process has potential advantages over other planarization techniques because of its adaptive nature. Hence, the IAP process can cater to substrates of varying topographies and pattern densities by changing the inkjetted material distribution, without any changes in hardware. The IAP process can also address pre-existing substrate topography selectively by conforming to the nominal shape while planarizing over the pattern layout. A schematic of the IAP process is shown in Figure 2. The goal of this paper is to present some preliminary results from the IAP process. A test pattern layout has been generated with the help of photolithography, and is shown in Figure 3. For the purpose of this trial, the nanoscale features have not been patterned, as it is expected that the planarization process will be blind to their presence. Thus, areas with nanoscale patterns have been patterned as a single feature of SiO2 with height equal to 100 nm. These features are adjacent to pattern-less areas, thus marking a drastic change in pattern density. As can be seen in Figure 4, the smallest length scale across which pattern density changes, is 70 microns. The goal of the IAP process is to be able to planarize this pattern with a film that conforms to pre-existing substrate topography. The targeted planarity of the film is 95% 3sigma, while the targeted film thickness at the tallest feature is less than 30 nm. In another trial, the inverse tone of the same layout will also be tested. This pattern has features of height equal to 100 nm where the previous pattern did not. The targeted metrics for the inverse layout are the same as the nominal layout.

Degassing of H2O in a phonolitic melt: A closer look at decompression experiments

NASA Astrophysics Data System (ADS)

Marxer, Holger; Bellucci, Philipp; Nowak, Marcus

2015-05-01

Melt degassing during magma ascent is controlled by the decompression rate and can be simulated in decompression experiments. H2O-bearing phonolitic melts were decompressed at a super-liquidus T of 1323 K in an internally heated argon pressure vessel, applying continuous decompression (CD) as well as to date commonly used step-wise decompression (SD) techniques to investigate the effect of decompression method on melt degassing. The hydrous melts were decompressed from 200 MPa at nominal decompression rates of 0.0028-1.7 MPa·s- 1. At final pressure (Pfinal), the samples were quenched rapidly at isobaric conditions with ~ 150 K·s- 1. The bubbles in the quenched samples are often deformed and dented. Flow textures in the glass indicate melt transport at high viscosity. We suggest that this observation is due to bubble shrinkage during quench. This general problem was mostly overlooked in the interpretation of experimentally degassed samples to date. Bubble shrinkage due to decreasing molar volume (Vm) of the exsolved H2O in the bubbles occurs during isobaric rapid quench until the melt is too viscous too relax. The decrease of Vm(H2O) during cooling at Pfinal of the experiments results in a decrease of the bubble volume by a shrinking factor Bs: At nominal decompression rates > 0.17 MPa·s- 1 and a Pfinal of 75 MPa, the decompression method has only minor influence on melt degassing. SD and CD result in high bubble number densities of 104-105 mm- 3. Fast P drop leads to immediate supersaturation with H2O in the melt. At such high nominal decompression rates, the diffusional transport of H2O is limited and therefore bubble nucleation is the predominant degassing process. The residual H2O contents in the melts decompressed to 75 MPa increase with nominal decompression rate. After homogeneous nucleation is triggered, CD rates ≤ 0.024 MPa·s- 1 facilitate continuous reduction of the supersaturation by H2O diffusion into previously nucleated bubbles. Bubble number densities of CD samples with low nominal decompression rates are several orders of magnitude lower than for SD experiments and the bubble diameters are larger. The reproducibility of MSD experiments with low nominal decompression rates is worse than for CD runs. Commonly used SD techniques are therefore not suitable to simulate melt degassing during continuous magma ascent with low ascent rates.

Nominal and functional task difficulty in skill acquisition: Effects on performance in two tests of transfer.

PubMed

Sanli, Elizabeth A; Lee, Timothy D

2015-06-01

The influence of nominal and functional task difficulty during the acquisition of a motor skill was examined in two tests of transfer of learning. The task involved a ballistic, target-directed, finger action. Nominal task difficulty was defined as the distance of the target from the home position. Functional task difficulty was created by manipulating the progression of target distances during practice. Based on the challenge point framework (Guadagnoli & Lee, 2004), we predicted that practice with a set of targets farther away from the performer would benefit from less functional task difficulty, while practice with a closer set of targets would benefit from more functional task difficulty. In single-task transfer tests, learners who practiced using the high nominal task difficulty targets benefitted in terms of persistence of performance over time. In dual-task transfer tests, groups with an intermediate combined (nominal and functional) task difficulty performed with greater persistence over time on tests of transfer than those who practiced with the highest or lowest combined difficulty. Together these findings suggest that the influences of nominal and functional task difficulty during acquisition are weighted differentially depending upon the transfer test context. The challenge point framework does not accurately capture this complex relationship in its current form. Copyright © 2015 Elsevier B.V. All rights reserved.

Optimization of a Hybrid Magnetic Bearing for a Magnetically Levitated Blood Pump via 3-D FEA

PubMed Central

Cheng, Shanbao; Olles, Mark W.; Burger, Aaron F.; Day, Steven W.

2011-01-01

In order to improve the performance of a magnetically levitated (maglev) axial flow blood pump, three-dimensional (3-D) finite element analysis (FEA) was used to optimize the design of a hybrid magnetic bearing (HMB). Radial, axial, and current stiffness of multiple design variations of the HMB were calculated using a 3-D FEA package and verified by experimental results. As compared with the original design, the optimized HMB had twice the axial stiffness with the resulting increase of negative radial stiffness partially compensated for by increased current stiffness. Accordingly, the performance of the maglev axial flow blood pump with the optimized HMBs was improved: the maximum pump speed was increased from 6000 rpm to 9000 rpm (50%). The radial, axial and current stiffness of the HMB was found to be linear at nominal operational position from both 3-D FEA and empirical measurements. Stiffness values determined by FEA and empirical measurements agreed well with one another. The magnetic flux density distribution and flux loop of the HMB were also visualized via 3-D FEA which confirms the designers’ initial assumption about the function of this HMB. PMID:22065892

Optimization of a Hybrid Magnetic Bearing for a Magnetically Levitated Blood Pump via 3-D FEA.

PubMed

Cheng, Shanbao; Olles, Mark W; Burger, Aaron F; Day, Steven W

2011-10-01

In order to improve the performance of a magnetically levitated (maglev) axial flow blood pump, three-dimensional (3-D) finite element analysis (FEA) was used to optimize the design of a hybrid magnetic bearing (HMB). Radial, axial, and current stiffness of multiple design variations of the HMB were calculated using a 3-D FEA package and verified by experimental results. As compared with the original design, the optimized HMB had twice the axial stiffness with the resulting increase of negative radial stiffness partially compensated for by increased current stiffness. Accordingly, the performance of the maglev axial flow blood pump with the optimized HMBs was improved: the maximum pump speed was increased from 6000 rpm to 9000 rpm (50%). The radial, axial and current stiffness of the HMB was found to be linear at nominal operational position from both 3-D FEA and empirical measurements. Stiffness values determined by FEA and empirical measurements agreed well with one another. The magnetic flux density distribution and flux loop of the HMB were also visualized via 3-D FEA which confirms the designers' initial assumption about the function of this HMB.

Electrical and optical performance of mid-wavelength infrared InAsSb heterostructure detectors

NASA Astrophysics Data System (ADS)

Gomółka, Emilia; Kopytko, Małgorzata; Michalczewski, Krystian; Kubiszyn, Łukasz; Kebłowski, Artur; Gawron, Waldemar; Martyniuk, Piotr; Piotrowski, Józef; Rutkowski, Jarosław

2017-10-01

In this work we investigate the high-operating temperature performance of InAsSb/AlSb heterostructure detectors with cut-off wavelengths near 5 μm at 230 K. The devices have been fabricated with different type of the absorbing layer: nominally undoped absorber, and both n- and p-type doped. The results show that the device performance strongly depends on absorber layer doping. Generally, p-type absorber provides higher values of current responsivity than n-type absorber, but at the same time also higher values of dark current. The device with nominally undoped absorbing layer shows moderate values of both current responsivity and dark current. Resulting detectivities D° of non-immersed devices varies from 2×109 to 7×109 cmHz1/2/W at 230 K, which is easily achievable with a two stage thermoelectric cooler.

Langmuir probe diagnostics of an atmospheric pressure, vortex-stabilized nitrogen plasma jet

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

Prevosto, L.; Mancinelli, B. R.; Kelly, H.

Langmuir probe measurements in an atmospheric pressure direct current (dc) plasma jet are reported. Sweeping probes were used. The experiment was carried out using a dc non-transferred arc torch with a rod-type cathode and an anode of 5 mm diameter. The torch was operated at a nominal power level of 15 kW with a nitrogen flow rate of 25 Nl min{sup -1}. A flat ion saturation region was found in the current-voltage curve of the probe. The ion saturation current to a cylindrical probe in a high-pressure non local thermal equilibrium (LTE) plasma was modeled. Thermal effects and ionization/recombination processesmore » inside the probe perturbed region were taken into account. Averaged radial profiles of the electron and heavy particle temperatures as well as the electron density were obtained. An electron temperature around 11 000 K, a heavy particle temperature around 9500 K and an electron density of about 4 Multiplication-Sign 10{sup 22} m{sup -3}, were found at the jet centre at 3.5 mm downstream from the torch exit. Large deviations from kinetic equilibrium were found throughout the plasma jet. The electron and heavy particle temperature profiles showed good agreement with those reported in the literature by using spectroscopic techniques. It was also found that the temperature radial profile based on LTE was very close to that of the electrons. The calculations have shown that this method is particularly useful for studying spraying-type plasma jets characterized by electron temperatures in the range 9000-14 000 K.« less

Kinetic energy offsets for multicharged ions from an electron beam ion source.

PubMed

Kulkarni, D D; Ahl, C D; Shore, A M; Miller, A J; Harriss, J E; Sosolik, C E; Marler, J P

2017-08-01

Using a retarding field analyzer, we have measured offsets between the nominal and measured kinetic energy of multicharged ions extracted from an electron beam ion source (EBIS). By varying source parameters, a shift in ion kinetic energy was attributed to the trapping potential produced by the space charge of the electron beam within the EBIS. The space charge of the electron beam depends on its charge density, which in turn depends on the amount of negative charge (electron beam current) and its velocity (electron beam energy). The electron beam current and electron beam energy were both varied to obtain electron beams of varying space charge and these were related to the observed kinetic energy offsets for Ar 4+ and Ar 8+ ion beams. Knowledge of these offsets is important for studies that seek to utilize slow, i.e., low kinetic energy, multicharged ions to exploit their high potential energies for processes such as surface modification. In addition, we show that these offsets can be utilized to estimate the effective radius of the electron beam inside the trap.

LiAl xCo 1- xO 2 as 4 V cathodes for lithium ion batteries

NASA Astrophysics Data System (ADS)

Huang, Haitao; Rao, G. V. Subba; Chowdari, B. V. R.

Nominal LiAl xCo 1- xO 2 with x ranging from 0.1 to 0.3 was prepared by heating mixture of Al(OH) 3, Co 3O 4 and LiOH at 750°C in air. The effect of substitution of non-transition metal, Al, in LiCoO 2 is investigated as a 4 V cathode for lithium ion. X-ray diffraction (XRD) indicates formation of a single phase (R3¯m) within this range of substitution. When cycled between 4.5 and 2.5 V vs. Li/Li + at a current density of 1 mA cm -2, the LiAl 0.15Co 0.85O 2 cathode exhibits reversible capacity of 160 mA h g -1 initially. XRD of the cathode made at the end of 10 cycles reveals no significant change on host structure.

Simplified Numerical Description of SPT Operations

NASA Technical Reports Server (NTRS)

Manzella, David H.

1995-01-01

A simplified numerical model of the plasma discharge within the SPT-100 stationary plasma thruster was developed to aid in understanding thruster operation. A one dimensional description was used. Non-axial velocities were neglected except for the azimuthal electron velocity. A nominal operating condition of 4.5 mg/s of xenon anode flow was considered with 4.5 Amperes of discharge current, and a peak radial magnetic field strength of 130 Gauss. For these conditions, the calculated results indicated ionization fractions of 0.99 near the thruster exit with a potential drop across the discharge of approximately 250 Volts. Peak calculated electron temperatures were found to be sensitive to the choice of total ionization cross section for ionization of atomic xenon by electron bombardment and ranged from 51 eV to 60 eV. The calculated ionization fraction, potential drop, and electron number density agree favorably with previous experiments. Calculated electron temperatures are higher than previously measured.

Modeling an Iodine Hall Thruster Plume in the Iodine Satellite (ISAT)

NASA Technical Reports Server (NTRS)

Choi, Maria

2016-01-01

An iodine-operated 200-W Hall thruster plume has been simulated using a hybrid-PIC model to predict the spacecraft surface-plume interaction for spacecraft integration purposes. For validation of the model, the plasma potential, electron temperature, ion current flux, and ion number density of xenon propellant were compared with available measurement data at the nominal operating condition. To simulate iodine plasma, various collision cross sections were found and used in the model. While time-varying atomic iodine species (i.e., I, I+, I2+) information is provided by HP Hall simulation at the discharge channel exit, the molecular iodine species (i.e., I2, I2+) are introduced as Maxwellian particles at the channel exit. Simulation results show that xenon and iodine plasma plumes appear to be very similar under the assumptions of the model. Assuming a sticking coefficient of unity, iodine deposition rate is estimated.

Modeling an Iodine Hall Thruster Plume in the Iodine Satellite (ISAT)

NASA Technical Reports Server (NTRS)

Choi, Maria

2016-01-01

An iodine-operated 200-W Hall thruster plume has been simulated using a hybrid-PIC model to predict the spacecraft surface-plume interaction for spacecraft integration purposes. For validation of the model, the plasma potential, electron temperature, ion current flux, and ion number density of xenon propellant were compared with available measurement data at the nominal operating condition. To simulate iodine plasma, various collision cross sections were found and used in the model. While time-varying atomic iodine species (i.e., I, I+, I2+) information is provided by HPHall simulation at the discharge channel exit, the molecular iodine species (i.e., I2, I2+) are introduced as Maxwellian particles at the channel exit. Simulation results show that xenon and iodine plasma plumes appear to be very similar under the assumptions of the model. Assuming a sticking coefficient of unity, iodine deposition rate is estimated.

Optical Diagnostics on HIT-SI3

NASA Astrophysics Data System (ADS)

Everson, Christopher; Jarboe, Thomas; Morgan, Kyle

2016-10-01

Interferometry and Thomson Scattering are implemented on the HIT-SI3 (Helicity Injected Torus - Steady Inductive 3) device to provide time resolved measurements of electron density and spatially resolved measurements of electron temperature, respectively. HIT-SI3 is a modification of the original HIT-SI apparatus that uses three injectors instead of two. The scientific aim of HIT-SI3 is to develop a deeper understanding of how injector behavior and interactions influence current drive and spheromak stability. The interferometer system makes use of an intermediate frequency between two parallel 184.3 μm Far-Infrared (FIR) laser cavities which are optically pumped by a CO2 laser. The phase shift in this beat frequency due to the plasma index of refraction is used to calculate the line-integrated electron density. To measure the electron temperature, Thomson Scattered light from a 20 J (1 GW pulse) Ruby laser off of free electrons in the HIT-SI3 plasma is measured simultaneously at four locations across the spheromak (nominally 23 cm minor radius). Polychromators bin the collected light into 3 spectral bands to detect the relative level of scattering. Work supported by the D.O.E.

Tungsten doped titanium dioxide nanowires for high efficiency dye-sensitized solar cells.

PubMed

Archana, P S; Gupta, Arunava; Yusoff, Mashitah M; Jose, Rajan

2014-04-28

Metal oxide semiconductors offering simultaneously high specific surface area and high electron mobility are actively sought for fabricating high performance nanoelectronic devices. The present study deals with synthesis of tungsten doped TiO2 (W:TiO2) nanowires (diameter ∼50 nm) by electrospinning and evaluation of their performance in dye-sensitized solar cells (DSCs). Similarity in the ionic radii between W(6+) and Ti(4+) and availability of two free electrons per dopant are the rationale for the present study. Materials were characterized by X-ray diffraction, scanning and transmission electron microscopy, X-ray fluorescence measurements, and absorption spectroscopy. Nanowires containing 2 at% W:TiO2 gave 90% higher short circuit current density (JSC) (∼15.39 mA cm(-2)) in DSCs with a nominal increase in the open circuit voltage compared with that of the undoped analogue (JSC ∼8.1 mA cm(-2)). The results are validated by multiple techniques employing absorption spectroscopy, electrochemical impedance spectroscopy and open circuit voltage decay. The above studies show that the observed increments resulted from increased dye-loading, electron density, and electron lifetime in tungsten doped samples.

Performance Data from a Wind-Tunnel Test of Two Main-rotor Blade Designs for a Utility-Class Helicopter

NASA Technical Reports Server (NTRS)

Singleton, Jeffrey D.; Yeager, William T., Jr.; Wilbur, Matthew L.

1990-01-01

An investigation was conducted in the NASA Langley Transonic Dynamics Tunnel to evaluate an advanced main rotor designed for use on a utility class helicopter, specifically the U.S. Army UH-60A Blackhawk. This rotor design incorporated advanced twist, airfoil cross sections, and geometric planform. For evaluation purposes, the current UH-60A main rotor was also tested and is referred to as the baseline blade set. A total of four blade sets were tested. One set of both the baseline and the advanced rotors were dynamically scaled to represent a full scale helicopter rotor blade design. The remaining advanced and baseline blade sets were not dynamically scaled so as to isolate the effects of structural elasticity. The investigation was conducted in hover and at rotor advance ratios ranging from 0.15 to 0.4 at a range of nominal test medium densities from 0.00238 to 0.009 slugs/cu ft. This range of densities, coupled with varying rotor lift and propulsive force, allowed for the simulation of several vehicle gross weight and density altitude combinations. Performance data are presented for all blade sets without analysis; however, cross referencing of data with flight condition may be useful to the analyst for validating aeroelastic theories and design methodologies as well as for evaluating advanced design parameters.

Solvent Hold Tank Sample Results for MCU-16-1247-1248-1249: August 2016 Monthly Sample

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

Fondeur, F. F.; Jones, D. H.

Savannah River National Laboratory (SRNL) received one set of Solvent Hold Tank (SHT) samples (MCU-16-1247-1248-1249), pulled on 08/22/2016 for analysis. The samples were combined and analyzed for composition. Analysis of the composite sample MCU-16-1247-1248-1249 indicated the Isopar™L concentration is above its nominal level (101%). The extractant (MaxCalix) and the modifier (CS-7SB) are 7% and 9 % below their nominal concentrations. The suppressor (TiDG) is 63% below its nominal concentration. This analysis confirms the solvent may require the addition of TiDG, and possibly of modifier and MaxCalix to restore then to nominal levels. Based on the current monthly sample, the levelsmore » of TiDG, Isopar™L, MaxCalix, and modifier are sufficient for continuing operation but are expected to decrease with time. Periodic characterization and trimming additions to the solvent are recommended. At the time of writing this report, A solvent trim batch containing TiDG, modifier and MaxCalix, was added to the SHT (October 2016) and expect the concentration of these components to be at their nominal values.« less

NEXT Long-Duration Test After 11,570 h and 237 kg of Xenon Processed

NASA Technical Reports Server (NTRS)

Soulas, George C.; Patterson, Michael J.; Herman, Daniel A.

2009-01-01

The NASA s Evolutionary Xenon Thruster (NEXT) program is developing the next-generation ion propulsion system with significant enhancements beyond the state-of-the-art in ion propulsion to provide future NASA science missions with enhanced mission capabilities at a low total development cost. As part of a comprehensive thruster service life assessment utilizing both testing and analyses, a Long-Duration Test (LDT) was initiated to validate and qualify the NEXT propellant throughput capability to a qualification-level of 450 kg, 1.5 times the mission-derived throughput requirement of 300 kg. This wear test is being conducted with a modified, flight-representative NEXT engineering model ion thruster, designated EM3. As of September 1, 2007, the thruster has accumulated 11,570 h of operation primarily at the thruster full-input-power of 6.9 kW with 3.52 A beam current and 1800 V beam power supply voltage. The thruster has processed 237 kg of xenon surpassing the NSTAR propellant throughput demonstrated during the extended life testing of the Deep Space 1 (DS1) flight spare. The NEXT LDT has demonstrated a total impulse of 9.78 10(exp 6) N(dot)s; the highest total impulse ever demonstrated by an ion thruster. Thruster performance tests are conducted periodically over the entire NEXT throttle table with input power ranging 0.5 to 6.9 kW. Thruster performance parameters including thrust, input power, specific impulse, and thruster efficiency have been nominal with little variation to date. Lifetime-limiting component erosion rates have been consistent with the NEXT service life assessment, which predicts the earliest failure sometime after 750 kg of xenon propellant throughput; well beyond the mission-derived lifetime requirement. The NEXT wear test data confirm that the erosion of the discharge keeper orifice, enlarging of nominal-current-density accelerator grid aperture cusps at full-power, and the decrease in cold grid-gap observed during NSTAR wear testing have been mitigated in the NEXT design. NEXT grid-gap data indicate a hot grid-gap at full-power that is 60 percent of the nominal cold grid-gap. This paper presents the status of the NEXT LDT to date with emphasis on comparison to the NSTAR extended life test results.

Density scaling of phantom materials for a 3D dose verification system.

PubMed

Tani, Kensuke; Fujita, Yukio; Wakita, Akihisa; Miyasaka, Ryohei; Uehara, Ryuzo; Kodama, Takumi; Suzuki, Yuya; Aikawa, Ako; Mizuno, Norifumi; Kawamori, Jiro; Saitoh, Hidetoshi

2018-05-21

In this study, the optimum density scaling factors of phantom materials for a commercially available three-dimensional (3D) dose verification system (Delta4) were investigated in order to improve the accuracy of the calculated dose distributions in the phantom materials. At field sizes of 10 × 10 and 5 × 5 cm 2 with the same geometry, tissue-phantom ratios (TPRs) in water, polymethyl methacrylate (PMMA), and Plastic Water Diagnostic Therapy (PWDT) were measured, and TPRs in various density scaling factors of water were calculated by Monte Carlo simulation, Adaptive Convolve (AdC, Pinnacle 3 ), Collapsed Cone Convolution (CCC, RayStation), and AcurosXB (AXB, Eclipse). Effective linear attenuation coefficients (μ eff ) were obtained from the TPRs. The ratios of μ eff in phantom and water ((μ eff ) pl,water ) were compared between the measurements and calculations. For each phantom material, the density scaling factor proposed in this study (DSF) was set to be the value providing a match between the calculated and measured (μ eff ) pl,water . The optimum density scaling factor was verified through the comparison of the dose distributions measured by Delta4 and calculated with three different density scaling factors: the nominal physical density (PD), nominal relative electron density (ED), and DSF. Three plans were used for the verifications: a static field of 10 × 10 cm 2 and two intensity modulated radiation therapy (IMRT) treatment plans. DSF were determined to be 1.13 for PMMA and 0.98 for PWDT. DSF for PMMA showed good agreement for AdC and CCC with 6 MV x ray, and AdC for 10 MV x ray. DSF for PWDT showed good agreement regardless of the dose calculation algorithms and x-ray energy. DSF can be considered one of the references for the density scaling factor of Delta4 phantom materials and may help improve the accuracy of the IMRT dose verification using Delta4. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Occupant Protection during Orion Crew Exploration Vehicle Landings

NASA Technical Reports Server (NTRS)

Gernhardt, Michael L.; Jones, J. A.; Granderson, B. K.; Somers, J. T.

2009-01-01

The constellation program is evaluating current vehicle design capabilities for nominal water landings and contingency land landings of the Orion Crew Exploration vehicle. The Orion Landing Strategy tiger team was formed to lead the technical effort for which associated activities include the current vehicle design, susceptibility to roll control and tip over, reviewing methods for assessing occupant injury during ascent / aborts /landings, developing an alternate seat/attenuation design solution which improves occupant protection and operability, and testing the seat/attenuation system designs to ensure valid results. The EVA physiology, systems and Performance (EPSP) project is leading the effort under the authority of the Tiger Team Steering committee to develop, verify, validate and accredit biodynamics models using a variety of crash and injury databases including NASCAR, Indy Car and military aircraft. The validated biodynamics models will be used by the Constellation program to evaluate a variety of vehicle, seat and restraint designs in the context of multiple nominal and off-nominal landing scenarios. The models will be used in conjunction with Acceptable Injury Risk definitions to provide new occupant protection requirements for the Constellation Program.

Temporal Associations of Popularity and Alcohol Use Among Middle School Students

PubMed Central

Tucker, Joan S.; Miles, Jeremy N. V.; D’Amico, Elizabeth J.; Zhou, Annie J.; Green, Harold D.; Shih, Regina A.

2012-01-01

Purpose The goal of this study is to better understand the longitudinal cross-lagged associations between popularity, assessed through self-rating and peer nominations, and alcohol use among middle school students. Methods The analytic sample is 1,835 6th–8th grade students who were initially recruited from three California middle schools and surveyed in the fall and spring semesters of two academic years. Students reported on their background characteristics, past month alcohol use, and perceived popularity. Additionally, students provided school-based friendship nominations, which were used to calculate peer-nominated popularity. A cross-lagged regression approach within a structural equation modeling framework was used to examine the longitudinal relationship between popularity (self-rated and peer-nominated) and alcohol use. Results There was a statistically significant (p = 0.024) association between peer-nominated popularity and the probability of alcohol consumption at the subsequent survey, but not vice versa. Our results suggest that in a scenario where 8% of students are past month drinkers, each increase of 5 friendship nominations is associated with a 30% greater risk of being a current drinker at the next wave. We found no evidence of longitudinal associations between past month alcohol consumption and self-rated popularity. Conclusions Popularity is a risk factor for drinking during the middle school years, with peer-nominated popularity being more predictive of use than self-perceptions of popularity. To inform alcohol prevention efforts for middle school students, additional research is needed to better understand why adolescents with a larger number of school-based friendship ties are more inclined to drink. PMID:23260843

COS/FUV Mapping of Stray PtNe Lamp Light Through FCA

NASA Astrophysics Data System (ADS)

Oliveira, Cristina

2010-09-01

This program determines which cross-dispersion locations lead to wavecal lamp {PtNe} light leaking through the flat-field calibration aperture {FCA}. This unexpected effect, observed initially in program 12096, led to a shut down of the COS/FUV detector due to a global count rate violation in Segment A of the G140L/1230 setting. Detector? threshold ?is ?600,000 ?FEC ?counts ?in? 10 seconds ?on each ?segment. ?If ?this ?level? is ?exceeded, ?the? detector? shuts ?down? the ?HV.In program 12096, for the G140L/1230 setting, at +6" from the nominal position in the cross-dispersion direction, 180,000 cts/sec were observed through the FCA in Segment A, and 49,000 cts/sec in Segment B {PtNe/FCA}. The corresponding wavecal count rate {PtNe/WCA} is 685 cts/sec in Segment A, implying that there is a scale factor of 263 between the FCA and WCA count rates. This scale factor could not be verified for Segment B, given that the PtNe lamp does not produce counts at the short wavelengths seen by G140L/1230/FUVB. However, this scaling factor is expected to be the same for both segments.The scaling factor derived from program 12096 is then used to predict the FCA count rates seen with all the gratings, in off-nominal positions where light might leak through the FCA in the current program.There is no light leak between the nominal position and positions up to and including +3" {at least not in Mar 2010 when program 12096 executed}, but somewhere above +3" and certainly at +6" the PtNe light starts leaking through the FCA.Light is not predicted to leak at negative POS-TARG positions from the nominal, and the purpose of this program is to verify that as well.Visits 1N to 6N take data at positions from +1.0" to +6.0", while visits 1S to 6S take data at positions from -1.0" to -6.0". Visits 10 through 13 take data at the nominal position, 0.0".At each position in the detector data is taken with the following settings:G130M/1055/1291/1327, G160M/1577/1623, and G140L/1280/1105, in this order.LAMP2 with CURRENT=LOW is used in all of these visits. In addition, at each position, one exposure with LAMP1 CURRENT=MED is also taken with the G130M/1055 setting, which leads to total counts in 10 sec more than a factor of 10 below the 600,000 limit. This exposure is used so that the ratio of LAMP1/MED to LAMP2/LOW can be calculated for the FCA at each position {in conjunction with the data obtained in visits 11, 12, and 13; see below}. In addition, the G130M/1055 exposures with LAMP1/MED and LAMP2/LOW will be used to determine if the lamp spot size is changing at each position.Depending on the total counts estimated for each setting, either a typical wave exposure is taken or special flash commands are used. Details are given in each visit.Exposures obtained with LAMP1/CURRENT=LOW are expected to have a 20% smaller count rate than exposures obtained with LAMP1/CURRENT=MED. Exposures obtained with LAMP2/CURRENT=MED are expected to have count rates similar to those obtained with LAMP1/CURRENT=MED, and exposures obtained with LAMP2/CURRENT=LOW are expected to have a count rate which is 1/7 of that obtainedwith LAMP2/CURRENT=MED.VISIT 10 OBTAINS LAMP1/CURRENT=MED+ LOW SPECTRA AT ALL THE M SETTINGS USED IN THIS PROGRAM, AT THE NOMINAL POSITION {0.0"}.VISIT 11 OBTAINS LAMP2/CURRENT=MED SPECTRA AT ALL THE M SETTINGS USED IN THIS PROGRAM, AT THE NOMINAL POSITION {0.0"}.VISIT 12 OBTAINS LAMP2/CURRENT=LOW SPECTRA AT ALL THE M SETTINGS USED IN THIS PROGRAM, AT THE NOMINAL POSITION {0.0"}.VISIT 13 OBTAINS LAMP1/CURRENT=MED, LOW AND LAMP2/CURRENT=MED, LOW SPECTRA AT ALL OF THE L SETTINGS USED IN THIS PROGRAM, AT THE NOMINAL POSITION {0.0"}.THE GOAL OF THESE VISITS IS TO DETERMINE THE RATIOS OF THE DIFFERENT LAMP SETTINGS AT DIFFERENT WAVELENGTHS, TO HELP IN ANALYZING THE DATA OBTAINED IN VISITS WHERE ONLY LAMP2/LOW IS USED.ALSO, THESE DATA WILL BE USED TO PREDICT WHAT THE COUNTS WOULD BE WITH G140L/1280/LAMP1/MED AT THE +6.0" POSITION {VIS6N, WHERE LAMP2/LOW IS USED}. THESE COUNTS WILL BE COMPARED WITH THE COUNTS OBTAINED IN PROGRAM 12096 WITH G140L/1230/LAMP1/MED, MORE THAN ONE YEAR AGO, TO LOOK FOR VARIABILITY, POSSIBLY INDICATING CHANGES TO THE LAMP SPOT SIZE.Visits 10 through 13, all executed at the nominal position, pose no safety concerns.CONSTRAINTS:- Visits 1N, 2N, 3N can be executed back to back as no light is expected to leak through the FCA. Visit 1N should execute before visit 2N, which should execute before visit 3N.- Visits 1S, 2S, and 3S can be executed back to back and do not have constraints relative to the other visits. Visit 1S should execute before visit 2S, which should execute before visit 3S- Visits 10, 11, 12, and 13 {data obtained at nominal position}, can also be executed back to back and have no constraints relative to other visits. However, these visits should be scheduled as soon as possible, because results of data anaysis will be used to inform execution of program 12678.- There should be an interval of at least two days between any of the visits mentioned above and the other visits in this program {4N, 5N, 6N, 4S, 5S, 6S} which could see light leaking through the FCA.- Visits 4S and 4N can be scheduled in the same week, but they don't need to be.- Visits 5S and 5N can be scheduled in the same week, but they don't need to be.- There should be an interval of at least 3 weeks between visit 4N and visit 5N.- Visits 6S and 6N can be scheduled in the same week, but they don't need to be.- There should be an interval of at least 3 weeks between visit 5N and visit 6N.- Visits 1S through 5S should be scheduled as soon as possible, the same is true for visits 1N to 4N.

Future large broadband switched satellite communications networks

NASA Technical Reports Server (NTRS)

Staelin, D. H.; Harvey, R. R.

1979-01-01

Critical technical, market, and policy issues relevant to future large broadband switched satellite networks are summarized. Our market projections for the period 1980 to 2000 are compared. Clusters of switched satellites, in lieu of large platforms, etc., are shown to have significant advantages. Analysis of an optimum terrestrial network architecture suggests the proper densities of ground stations and that link reliabilities 99.99% may entail less than a 10% cost premium for diversity protection at 20/30 GHz. These analyses suggest that system costs increase as the 0.6 power of traffic. Cost estimates for nominal 20/30 GHz satellite and ground facilities suggest optimum system configurations might employ satellites with 285 beams, multiple TDMA bands each carrying 256 Mbps, and 16 ft ground station antennas. A nominal development program is outlined.

Electrical and optical performance of midwave infrared InAsSb heterostructure detectors

NASA Astrophysics Data System (ADS)

Gomółka, Emilia; Kopytko, Małgorzata; Markowska, Olga; Michalczewski, Krystian; Kubiszyn, Łukasz; Kębłowski, Artur; Jureńczyk, Jarosław; Gawron, Waldemar; Martyniuk, Piotr Marcin; Piotrowski, Józef; Rutkowski, Jarosław; Rogalski, Antoni

2018-02-01

We investigate the high-operating temperature performance of InAsSb/AlSb heterostructure detectors with cutoff wavelengths near 5 μm at 230 K. The devices have been fabricated with different types of absorbing layers: nominally undoped absorber (with n-type conductivity), and both n- and p-type doped. The results show that the device performance strongly depends on absorber layer type. Generally, the p-type absorber provides higher values of current responsivity than the n-type absorber, but at the same time also higher values of dark current. The device with the nominally undoped absorbing layer shows moderate values of both current responsivity and dark current. Resulting detectivities D * of nonimmersed devices vary from 2 × 109 to 5 × 109 cm Hz1/2 W ? 1 at 230 K, which is easily achievable with a two-stage thermoelectric cooler. Optical immersion increases the detectivity up to 5 × 1010 cm Hz1/2 W ? 1.

Motor torque compensation of an induction electric motor by adjusting a slip command during periods of supposed change in motor temperature

DOEpatents

Kelledes, William L.; St. John, Don K.

1992-01-01

The present invention maintains constant torque in an inverter driven AC induction motor during variations in rotor temperature. It is known that the torque output of a given AC induction motor is dependent upon rotor temperature. At rotor temperatures higher than the nominal operating condition the rotor impedance increases, reducing the rotor current and motor torque. In a similar fashion, the rotor impedance is reduced resulting in increased rotor current and motor torque when the rotor temperature is lower than the nominal operating condition. The present invention monitors the bus current from the DC supply to the inverter and adjusts the slip frequency of the inverter drive to maintain a constant motor torque. This adjustment is based upon whether predetermined conditions implying increased rotor temperature or decreased rotor temperature exist for longer that a predetermined interval of time.

A comparative study of nonwoven fabrics made with two distinctly different forms of greige cotton lint

USDA-ARS?s Scientific Manuscript database

Two sets of nonwoven fabrics of nominal 80 g/m2 density were produced on commercial equipment, using two distinctly different forms of greige cotton lint. One was a regular cotton taken from a randomly picked classical bale and the other was a uniquely pre-cleaned UltraCleanTM cotton produced by a w...

The influence of student characteristics on the dependability of behavioral observation data.

PubMed

Briesch, Amy M; Volpe, Robert J; Ferguson, Tyler David

2014-06-01

Although generalizability theory has been used increasingly in recent years to investigate the dependability of behavioral estimates, many of these studies have relied on use of general education populations as opposed to those students who are most likely to be referred for assessment due to problematic classroom behavior (e.g., inattention, disruption). The current study investigated the degree to which differences exist in terms of the magnitude of both variance component estimates and dependability coefficients between students nominated by their teachers for Tier 2 interventions due to classroom behavior problems and a general classroom sample (i.e., including both nominated and non-nominated students). The academic engagement levels of 16 (8 nominated, 8 non-nominated) middle school students were measured by 4 trained observers using momentary time-sampling procedures. A series of G and D studies were then conducted to determine whether the 2 groups were similar in terms of the (a) distribution of rating variance and (b) number of observations needed to achieve an adequate level of dependability. Results suggested that the behavior of students in the teacher-nominated group fluctuated more across time and that roughly twice as many observations would therefore be required to yield similar levels of dependability compared with the combined group. These findings highlight the importance of constructing samples of students that are comparable to those students with whom the measurement method is likely to be applied when conducting psychometric investigations of behavioral assessment tools. PsycINFO Database Record (c) 2014 APA, all rights reserved.

A novel compact low impedance Marx generator with quasi-rectangular pulse output

NASA Astrophysics Data System (ADS)

Liu, Hongwei; Jiang, Ping; Yuan, Jianqiang; Wang, Lingyun; Ma, Xun; Xie, Weiping

2018-04-01

In this paper, a novel low impedance compact Marx generator with near-square pulse output based on the Fourier theory is developed. Compared with the traditional Marx generator, capacitors with different capacity have been used. It can generate a high-voltage quasi-rectangular pulse with a width of 100 ns at low impedance load, and it also has high energy density and power density. The generator consists of 16 modules. Each module comprises an integrative single-ended plastic case capacitor with a nominal value of 54 nF, four ceramic capacitors with a nominal value of 1.5 nF, a gas switch, a charging inductor, a grounding inductor, and insulators which provide mechanical support for all elements. In the module, different discharge periods from different capacitors add to the main circuit to form a quasi-rectangular pulse. The design process of the generator is analyzed, and the test results are provided here. The generator achieved pulse output with a rise time of 32 ns, pulse width of 120 ns, flat-topped width (95%-95%) of 50 ns, voltage of 550 kV, and power of 20 GW.

B{sub 4}C-SiC reaction-sintered coatings on graphite plasma facing components

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

Valentine, P.G.; Trester, P.W.; Winter, J.

1994-05-01

Boron carbide plus silicon carbide (B{sub 4}C-SiC) reaction-sintered coatings for use on graphite plasma-facing components were developed. Such coatings are of interest in TEXTOR tokamak limiter-plasma interactions as a means of reducing carbon erosion, of providing a preferred release of boron for oxygen gettering, and of investigating silicon`s effect on radiative edge phenomena. Specimens evaluated had (a) either Ringsdorfwerke EK 98 graphite or Le Carbon Lorraine felt-type AEROLOR A05 CFC substrates; (b) multiphase coatings, comprised of B{sub 4}C, Sic, and graphite; (c) nominal coating compositions of 69 wt.-% B{sub 4}C + 31 wt.-% SiC; and (d) nominal coating thicknesses betweenmore » 250 and 775 {mu}m. Coated coupons were evaluated by high heat flux experiments in the JUDITH (electron beam) test facility at KFA. Simulated disruptions, with energy densities up to 10 MJm{sup {minus}2}, and normal operation simulations, with power densities up to 12 MWm{sup {minus}2}, were conducted. The coatings remained adherent; at the highest levels tested, minor changes occurred, including localized remelting, modification of the crystallographic phases, occasional microcracking, and erosion.« less

Temporal associations of popularity and alcohol use among middle school students.

PubMed

Tucker, Joan S; Miles, Jeremy N V; D'Amico, Elizabeth J; Zhou, Annie J; Green, Harold D; Shih, Regina A

2013-01-01

The goal of this study is to better understand the longitudinal cross-lagged associations between popularity, assessed through self-rating and peer nominations, and alcohol use among middle school students. The analytical sample comprises 1,835 sixth- to eighth-grade students who were initially recruited from three California middle schools and surveyed in the fall and spring semesters of 2 academic years. Students reported on their background characteristics, past-month alcohol use, and perceived popularity. Additionally, students provided school-based friendship nominations, which were used to calculate peer-nominated popularity. A cross-lagged regression approach within a structural equation modeling framework was used to examine the longitudinal relationship between popularity (self-rated and peer-nominated) and alcohol use. There was a statistically significant (p = .024) association between peer-nominated popularity and the probability of alcohol consumption at the subsequent survey, but not vice versa. Our results suggest that in a scenario where 8% of students are past-month drinkers, each increase of five friendship nominations is associated with a 30% greater risk of being a current drinker at the next wave. We found no evidence of longitudinal associations between past-month alcohol consumption and self-rated popularity. Popularity is a risk factor for drinking during the middle school years, with peer-nominated popularity being more predictive of use than self-perceptions of popularity. To inform alcohol prevention efforts for middle school students, additional research is needed to better understand why adolescents with a larger number of school-based friendship ties are more inclined to drink. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Refinement of current WisDOT HMA mixture application guidelines related to NMAS and aggregate characteristics.

DOT National Transportation Integrated Search

2014-01-01

Current Wisconsin Department of Transportation (WisDOT) Specifications limit nominal maximum aggregate : size (NMAS) of hot-mix asphalt (HMA) to 12.5 mm in the surface layer and 19.0 mm in lower layers. This : potentially places unnecessary limits on...

Nonimaging optical designs for maximum-power-density remote irradiation.

PubMed

Feuermann, D; Gordon, J M; Ries, H

1998-04-01

Designs for flexible, high-power-density, remote irradiation systems are presented. Applications include industrial infrared heating such as in semiconductor processing, alternatives to laser light for certain medical procedures, and general remote high-brightness lighting. The high power densities in herent to the small active radiating regions of conventional metal-halide, halogen, xenon, microwave-sulfur, and related lamps can be restored with nonimaging concentrators with little loss of power. These high fluxlevels can then be transported at high transmissivity with light channels such as optical fibers or lightpipes, and reshaped into luminaires that can deliver prescribed angular and spatial flux distributions onto desired targets. Details for nominally two- and three-dimensional systems are developed, along with estimates ofoptical performance.

A computer program for borehole compensation of dual-detector density well logs

USGS Publications Warehouse

Scott, James Henry

1978-01-01

The computer program described in this report was developed for applying a borehole-rugosity and mudcake compensation algorithm to dual-density logs using the following information: the water level in the drill hole, hole diameter (from a caliper log if available, or the nominal drill diameter if not), and the two gamma-ray count rate logs from the near and far detectors of the density probe. The equations that represent the compensation algorithm and the calibration of the two detectors (for converting countrate or density) were derived specifically for a probe manufactured by Comprobe Inc. (5.4 cm O.D. dual-density-caliper); they are not applicable to other probes. However, equivalent calibration and compensation equations can be empirically determined for any other similar two-detector density probes and substituted in the computer program listed in this report. * Use of brand names in this report does not necessarily constitute endorsement by the U.S. Geological Survey.

Reducing Magnetic Fields Around Power Cables

NASA Technical Reports Server (NTRS)

Sargent, Noel B.; Gitelman, Florida; Pongracz-Bartha, Edward; Spalding, John

1993-01-01

Four power conductors arranged symmetrically about fifth grounded conductor. Four current-carrying wires arranged symmetrically around central grounded wire that nominally carries no current. In comparison with other cable configurations, this one results in smaller magnetic fields around cable. Technique for use when size of wires in cable makes twisting impractical.

Double-HE-Layer Detonation-Confinement Sandwich Tests: The Effect of Slow-Layer Density

NASA Astrophysics Data System (ADS)

Hill, Larry

2013-06-01

Over a period of several years, we have explored the phenomenon in which slabs of high explosives (HEs) with differing detonation speeds are joined along one of their faces. Both are initiated (usually by a line-wave generator) at one edge. If there were no coupling between the layers, the detonation in the fast HE would outrun that in the slow HE. In reality, the detonation in the fast HE transmits an oblique shock into the slow HE, the phase speed of which is equal to the speed of the fast HE. This has one of two effects depending on the particulars. First, the oblique shock transmitted to the slow HE can pre-shock and deaden it, extinguishing the detonation in the slow HE. Second, the oblique shock can transversely initiate the slow layer, pulling its detonation along at the fast HE speed. When the second occurs, it does so at the ``penalty'' of a nominally dead layer, which forms in the slow HE adjacent to the material interface. We present the results of tests in which the fast layer was 3-mm-thick PBX 9501 (95 wt% HMX), and the slow layer was 8-mm-thick PBX 9502 (95 wt% TATB). The purpose was to observe the effect of slow layer density on the ``dead'' layer thickness. Very little effect was observed across the nominal PBX 9502 density range, 1.885-1.895 g/cc.

Heat Transfer in High-Temperature Fibrous Insulation

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran

2002-01-01

The combined radiation/conduction heat transfer in high-porosity, high-temperature fibrous insulations was investigated experimentally and numerically. The effective thermal conductivity of fibrous insulation samples was measured over the temperature range of 300-1300 K and environmental pressure range of 1.33 x 10(exp -5)-101.32 kPa. The fibrous insulation samples tested had nominal densities of 24, 48, and 72 kilograms per cubic meter and thicknesses of 13.3, 26.6 and 39.9 millimeters. Seven samples were tested such that the applied heat flux vector was aligned with local gravity vector to eliminate natural convection as a mode of heat transfer. Two samples were tested with reverse orientation to investigate natural convection effects. It was determined that for the fibrous insulation densities and thicknesses investigated no heat transfer takes place through natural convection. A finite volume numerical model was developed to solve the governing combined radiation and conduction heat transfer equations. Various methods of modeling the gas/solid conduction interaction in fibrous insulations were investigated. The radiation heat transfer was modeled using the modified two-flux approximation assuming anisotropic scattering and gray medium. A genetic-algorithm based parameter estimation technique was utilized with this model to determine the relevant radiative properties of the fibrous insulation over the temperature range of 300-1300 K. The parameter estimation was performed by least square minimization of the difference between measured and predicted values of effective thermal conductivity at a density of 24 kilograms per cubic meters and at nominal pressures of 1.33 x 10(exp -4) and 99.98 kPa. The numerical model was validated by comparison with steady-state effective thermal conductivity measurements at other densities and pressures. The numerical model was also validated by comparison with a transient thermal test simulating reentry aerodynamic heating conditions.

Shaping and reinforcement of melt textured YBa2Cu3O7-δ superconductors

NASA Astrophysics Data System (ADS)

Meslin, S.; Harnois, C.; Chubilleau, C.; Horvath, D.; Grossin, D.; Suddhakar, E. R.; Noudem, J. G.

2006-07-01

From porous Y2BaCuO5 (Y211) with various grain sizes, single domain ceramic composites YBa2Cu3Oy/Y2BaCuO5 have been prepared by combination of the infiltration and top seed growth (ITSG) process. In addition, perforated Y123 has been prepared from Y211 by the ITSG method in order to magnify the specific surface and then increase oxygen diffusion into the core of the material. Magnetic and electrical properties were determined and correlate well with the microstructure of the composites and were compared to the conventional doped or undoped YBa2Cu3Oy (Y123). From magnetic measurements, high critical current densities, Jc, of 86 000 A cm-2 have been measured. Transport Jc values higher than 10 600 A cm-2 are reached at 77 K and 0 T, corresponding to the nominal critical currents of 325 A injected reproducibly through sections less than 3.082 mm2. This confirms the high quality of single domains obtained with a well controlled ITSG process. On the other hand, the perforated samples were reinforced using resin impregnation and the flux mapping has been investigated.

The Nominal/Generic Specific Heat per Average Atom Concept for CHNO Energetic Materials

DTIC Science & Technology

2006-07-01

Heat Per Average Atom for TATB. RDX . TNT. HMX . and HNS... HMX can exist in different solid polymorphic forms. At a certain temperature, TT, one form may change to another form if the heat energy of...densities ( p. ) up to, and including, crystals at TMD for TNT, RDX , HMX , and TATB. The presently proposed N/G CP magnitude, in certain temperature

Artifacts Of Spectral Analysis Of Instrument Readings

NASA Technical Reports Server (NTRS)

Wise, James H.

1995-01-01

Report presents experimental and theoretical study of some of artifacts introduced by processing outputs of two nominally identical low-frequency-reading instruments; high-sensitivity servo-accelerometers mounted together and operating, in conjunction with signal-conditioning circuits, as seismometers. Processing involved analog-to-digital conversion with anti-aliasing filtering, followed by digital processing including frequency weighting and computation of different measures of power spectral density (PSD).

Status of the NEXT Ion Thruster Long-Duration Test After 10,100 hr and 207 kg Demonstrated

NASA Technical Reports Server (NTRS)

Herman, Daniel A.; Soulas, George C.; Patterson, Michael J.

2008-01-01

The NASA s Evolutionary Xenon Thruster (NEXT) program is developing the next-generation ion propulsion system with significant enhancements beyond the state-of-the-art in ion propulsion to provide future NASA science missions with enhanced mission capabilities at a low total development cost. As part of a comprehensive thruster service life assessment utilizing both testing and analyses, a Long-Duration Test (LDT) was initiated to validate and qualify the NEXT propellant throughput capability to a qualification-level of 450 kg, 1.5 times the mission-derived throughput requirement of 300 kg. This wear test is being conducted with a modified, flight-representative NEXT engineering model ion thruster, designated EM3. As of June 21, 2007, the thruster has accumulated 10,100 hr of operation at the thruster full-input-power of 6.9 kW with 3.52 A beam current and 1800 V beam power supply voltage. The thruster has processed 207 kg of xenon and demonstrated a total impulse of 8.5 106 N-s; the highest total impulse ever demonstrated by an ion thruster in the history of space propulsion. Thruster performance tests are conducted periodically over the entire NEXT throttle table with input power ranging 0.5 to 6.9 kW. Overall ion thruster performance parameters including thrust, input power, specific impulse, and thruster efficiency have been nominal with little variation to date. Lifetime-limiting component erosion rates have been consistent with the NEXT service life assessment, which predicts the earliest failure sometime after 750 kg of xenon propellant throughput; well beyond the mission-derived lifetime requirement. The NEXT wear test data confirm that the erosion of the discharge keeper orifice, enlarging of nominal-current-density accelerator grid aperture cusps, and the decrease in cold grid-gap observed during the NSTAR Extended Life Test have been mitigated. This paper presents the status of the NEXT LDT to date.

Small population size of Pribilof Rock Sandpipers confirmed through distance-sampling surveys in Alaska

USGS Publications Warehouse

Ruthrauff, Daniel R.; Tibbitts, T. Lee; Gill, Robert E.; Dementyev, Maksim N.; Handel, Colleen M.

2012-01-01

The Rock Sandpiper (Calidris ptilocnemis) is endemic to the Bering Sea region and unique among shorebirds in the North Pacific for wintering at high latitudes. The nominate subspecies, the Pribilof Rock Sandpiper (C. p. ptilocnemis), breeds on four isolated islands in the Bering Sea and appears to spend the winter primarily in Cook Inlet, Alaska. We used a stratified systematic sampling design and line-transect method to survey the entire breeding range of this population during springs 2001-2003. Densities were up to four times higher on the uninhabited and more northerly St. Matthew and Hall islands than on St. Paul and St. George islands, which both have small human settlements and introduced reindeer herds. Differences in density, however, appeared to be more related to differences in vegetation than to anthropogenic factors, raising some concern for prospective effects of climate change. We estimated the total population at 19 832 birds (95% CI 17 853–21 930), ranking it among the smallest of North American shorebird populations. To determine the vulnerability of C. p. ptilocnemis to anthropogenic and stochastic environmental threats, future studies should focus on determining the amount of gene flow among island subpopulations, the full extent of the subspecies' winter range, and the current trajectory of this small population.

Simulation of electric vehicles with hybrid power systems

NASA Astrophysics Data System (ADS)

Burke, A. F.; Cole, G. H.

Computer programs for the simulation of the operation of electric vehicles with hybrid power systems are described. These programs treat cases in which high energy density ultracapacitors or high power density pulse batteries are used to load level the main energy storage battery in the vehicle. A generalized control strategy for splitting the power between the main battery and the pulse power devices is implemented such that the user can specify the nominal battery power as a function of the state-of-charge of the ultracapacitor or pulse power battery. The programs display graphically on the screen, as they run, the power from both the main battery and the pulse power device and the state-of-charge of the pulse power device. After each run is completed, a summary is printed out from which the effect of load leveling the battery on vehicle range and energy consumption can be determined. Default input files are provided with the programs so various combinations of vehicles, driveline components, and batteries of special current interest to the EV community can be run with either type of pulse power device. Typical simulation results are shown including cases in which the pulse power devices are connected in parallel with the main battery without interface electronics.

NOMINAL VALUES FOR SELECTED SOLAR AND PLANETARY QUANTITIES: IAU 2015 RESOLUTION B3

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

Prša, Andrej; Harmanec, Petr; Torres, Guillermo

In this brief communication we provide the rationale for and the outcome of the International Astronomical Union (IAU) resolution vote at the XXIXth General Assembly in Honolulu, Hawaii, in 2015, on recommended nominal conversion constants for selected solar and planetary properties. The problem addressed by the resolution is a lack of established conversion constants between solar and planetary values and SI units: a missing standard has caused a proliferation of solar values (e.g., solar radius, solar irradiance, solar luminosity, solar effective temperature, and solar mass parameter) in the literature, with cited solar values typically based on best estimates at the timemore » of paper writing. As precision of observations increases, a set of consistent values becomes increasingly important. To address this, an IAU Working Group on Nominal Units for Stellar and Planetary Astronomy formed in 2011, uniting experts from the solar, stellar, planetary, exoplanetary, and fundamental astronomy, as well as from general standards fields to converge on optimal values for nominal conversion constants. The effort resulted in the IAU 2015 Resolution B3, passed at the IAU General Assembly by a large majority. The resolution recommends the use of nominal solar and planetary values, which are by definition exact and are expressed in SI units. These nominal values should be understood as conversion factors only, not as the true solar/planetary properties or current best estimates. Authors and journal editors are urged to join in using the standard values set forth by this resolution in future work and publications to help minimize further confusion.« less

Nominal Values for Selected Solar and Planetary Quantities: IAU 2015 Resolution B3

NASA Astrophysics Data System (ADS)

Prša, Andrej; Harmanec, Petr; Torres, Guillermo; Mamajek, Eric; Asplund, Martin; Capitaine, Nicole; Christensen-Dalsgaard, Jørgen; Depagne, Éric; Haberreiter, Margit; Hekker, Saskia; Hilton, James; Kopp, Greg; Kostov, Veselin; Kurtz, Donald W.; Laskar, Jacques; Mason, Brian D.; Milone, Eugene F.; Montgomery, Michele; Richards, Mercedes; Schmutz, Werner; Schou, Jesper; Stewart, Susan G.

2016-08-01

In this brief communication we provide the rationale for and the outcome of the International Astronomical Union (IAU) resolution vote at the XXIXth General Assembly in Honolulu, Hawaii, in 2015, on recommended nominal conversion constants for selected solar and planetary properties. The problem addressed by the resolution is a lack of established conversion constants between solar and planetary values and SI units: a missing standard has caused a proliferation of solar values (e.g., solar radius, solar irradiance, solar luminosity, solar effective temperature, and solar mass parameter) in the literature, with cited solar values typically based on best estimates at the time of paper writing. As precision of observations increases, a set of consistent values becomes increasingly important. To address this, an IAU Working Group on Nominal Units for Stellar and Planetary Astronomy formed in 2011, uniting experts from the solar, stellar, planetary, exoplanetary, and fundamental astronomy, as well as from general standards fields to converge on optimal values for nominal conversion constants. The effort resulted in the IAU 2015 Resolution B3, passed at the IAU General Assembly by a large majority. The resolution recommends the use of nominal solar and planetary values, which are by definition exact and are expressed in SI units. These nominal values should be understood as conversion factors only, not as the true solar/planetary properties or current best estimates. Authors and journal editors are urged to join in using the standard values set forth by this resolution in future work and publications to help minimize further confusion.

Viscosity, density, and thermal conductivity of aluminum oxide and zinc oxide nanolubricants

PubMed Central

Kedzierski, M.A.; Brignoli, R.; Quine, K.T.; Brown, J.S.

2017-01-01

This paper presents liquid kinematic viscosity, density, and thermal conductivity measurements of eleven different synthetic polyolester-based nanoparticle nanolubricants (dispersions) at atmospheric pressure over the temperature range 288 K to 318 K. Aluminum oxide (Al2O3) and zinc oxide (ZnO) nanoparticles with nominal diameters of 127 nm and 135 nm, respectively, were investigated. A good dispersion of the spherical and non-spherical nanoparticles in the lubricant was maintained with a surfactant. Viscosity, density, and thermal conductivity measurements were made for the neat lubricant along with eleven nanolubricants with differing nanoparticle and surfactant mass fractions. Existing models were used to predict kinematic viscosity (±20%), thermal conductivity (±1%), and specific volume (±6%) of the nanolubricant as a function of temperature, nanoparticle mass fraction, surfactant mass fraction, and nanoparticle diameter. The liquid viscosity, density and thermal conductivity were shown to increase with respect to increasing nanoparticle mass fraction. PMID:28736463

Response of the plasma to the size of an anode electrode biased near the plasma potential

DOE PAGES

Barnat, E. V.; Laity, G. R.; Baalrud, S. D.

2014-10-01

As the size of a positively biased electrode increases, the nature of the interface formed between the electrode and the host plasma undergoes a transition from an electron-rich structure (electron sheath) to an intermediate structure containing both ion and electron rich regions (double layer) and ultimately forms an electron-depleted structure (ion sheath). In this study, measurements are performed to further test how the size of an electron-collecting electrode impacts the plasma discharge the electrode is immersed in. This is accomplished using a segmented disk electrode in which individual segments are individually biased to change the effective surface area of themore » anode. Measurements of bulk plasma parameters such as the collected current density, plasma potential, electron density, electron temperature and optical emission are made as both the size and the bias placed on the electrode are varied. Abrupt transitions in the plasma parameters resulting from changing the electrode surface area are identified in both argon and helium discharges and are compared to the interface transitions predicted by global current balance [S. D. Baalrud, N. Hershkowitz, and B. Longmier, Phys. Plasmas 14, 042109 (2007)]. While the size-dependent transitions in argon agree, the size-dependent transitions observed in helium systematically occur at lower electrode sizes than those nominally derived from prediction. Thus, the discrepancy in helium is anticipated to be caused by the finite size of the interface that increases the effective area offered to the plasma for electron loss to the electrode.« less

Glass-ceramic route of BSCCO superconductors - Fabrication of amorphous precursor

NASA Astrophysics Data System (ADS)

Nilsson, Andreas; Gruner, Wolfgang; Acker, Jörg; Wetzig, Klaus

2007-09-01

It is well known that many Bi-Sr-Ca-Cu-O compositions are glass-forming and some Bi-based glasses such as Bi 2Sr 2CaCu 2O x and Bi 2Sr 2Ca 2Cu 3O x are converted into high critical temperature superconductors after proper annealing. In order to fabricate superconductors having high- Tc and high critical current density using the glass-ceramic route, it is necessary to clarify the total chemical composition of the quenched glasses prepared in most cases by rapid quenching of melts from around 1200 °C in air. The total oxygen content measured directly reflects a significant oxygen deficit due to the melting process. We have also investigated the cation content in quenched Bi 2Sr 2Ca 2Cu 3O x precursors and found that there are substantial differences from the nominal composition to the quenched materials especially for calcium. Such glasses also show some CaO crystalline reflexes in the XRD patterns.

Fabrication and testing of silver-hydrogen cells

NASA Technical Reports Server (NTRS)

Debicarri, D. J.; Charkey, A.

1978-01-01

Silver electrodes containing various additives were fabricated and tested in single electrode cells in order to improve the electrochemical utilization of sintered silver cathodes in Ag-H2 aerospace batteries. A standard stack arrangement was used which featured a NASA-developed organic-inorganic separator. All cells were cycled in a regime designed to remove 75% of the cells nominal capacity based on 3.3 gms/AHr Ag utilization. In cases where performance degradation was observed, the main feature mode appeared to be corrosion of either the expanded silver current collector or the connection between the silver electrode and the electrode tab. Promising silver electrodes from single electrode studies were used in the construction of 35 AHr Ag-H2 cells. Two such cells were constructed and installed in heavy walled pressure vessels for testing. Based on the data obtained from all cells tested during the program, four lightweight 35 AHr cells were fabricated. During acceptance testing these cells yielded an average gravimetric energy density of 30 WHr/1b.

N-body simulations of collective effects in spiral and barred galaxies

NASA Astrophysics Data System (ADS)

Zhang, X.

2016-10-01

We present gravitational N-body simulations of the secular morphological evolution of disk galaxies induced by density wave modes. In particular, we address the demands collective effects place on the choice of simulation parameters, and show that the common practice of the use of a large gravity softening parameter was responsible for the failure of past simulations to correctly model the secular evolution process in galaxies, even for those simulations where the choice of basic state allows an unstable mode to emerge, a prerequisite for obtaining the coordinated radial mass flow pattern needed for secular evolution of galaxies along the Hubble sequence. We also demonstrate that the secular evolution rates measured in our improved simulations agree to an impressive degree with the corresponding rates predicted by the recently-advanced theories of dynamically-driven secular evolution of galaxies. The results of the current work, besides having direct implications on the cosmological evolution of galaxies, also shed light on the general question of how irreversibility emerges from a nominally reversible physical system.

Solvent Hold Tank Sample Results for MCU-16-596-597-598: April 2016 Monthly Sample

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

Fondeur, F. F.; Jones, D. H.

2016-07-12

Savannah River National Laboratory (SRNL) received one set of Solvent Hold Tank (SHT) samples (MCU-16-596-597-598), pulled on 04/30/2016 for analysis. The samples were combined and analyzed for composition. Analysis of the composite sample MCU-16-596-597-598 indicated the Isopar™L concentration is above its nominal level (102%). The modifier (CS-7SB) is 14% below its nominal concentration, while the TiDG and MaxCalix concentrations are at and above their nominal concentrations, respectively. This analysis confirms the solvent may require the addition of modifier. Based on the current monthly sample, the levels of TiDG, Isopar™L, MaxCalix, and modifier are sufficient for continuing operation but are expectedmore » to decrease with time. Periodic characterization and trimming additions to the solvent are recommended.« less

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

Fondeur, F. F.; Jones, D. H.

Savannah River National Laboratory (SRNL) received one set of three Solvent Hold Tank (SHT) samples (MCU-16-1363-1364-1365), pulled on 11/15/2016 for analysis. The samples were combined and analyzed for composition. Analysis of the composite sample MCU-16-1363-1364-1365 indicated the Isopar™L concentration is at its nominal level (100%). The extractant (MaxCalix) and the modifier (CS- 7SB) are 8% and 2 % below their nominal concentrations. The suppressor (TiDG) is 7% below its nominal concentration. This analysis confirms the trim and Isopar™ additions to the solvent in November. This analysis also indicates the solvent did not require further additions. Based on the current monthlymore » sample, the levels of TiDG, Isopar™L, MaxCalix, and modifier are sufficient for continuing operation but are expected to decrease with time. Periodic characterization and trimming additions to the solvent are recommended.« less

Comparison between measured and computed magnetic flux density distribution of simulated transformer core joints assembled from grain-oriented and non-oriented electrical steel

NASA Astrophysics Data System (ADS)

Shahrouzi, Hamid; Moses, Anthony J.; Anderson, Philip I.; Li, Guobao; Hu, Zhuochao

2018-04-01

The flux distribution in an overlapped linear joint constructed in the central region of an Epstein Square was studied experimentally and results compared with those obtained using a computational magnetic field solver. High permeability grain-oriented (GO) and low permeability non-oriented (NO) electrical steels were compared at a nominal core flux density of 1.60 T at 50 Hz. It was found that the experimental results only agreed well at flux densities at which the reluctance of different paths of the flux are similar. Also it was revealed that the flux becomes more uniform when the working point of the electrical steel is close to the knee point of the B-H curve of the steel.

A simple solution to systematic errors in density determination by X-ray reflectivity: The XRR-density evaluation (XRR-DE) method

NASA Astrophysics Data System (ADS)

Bergese, P.; Bontempi, E.; Depero, L. E.

2006-10-01

X-ray reflectivity (XRR) is a non-destructive, accurate and fast technique for evaluating film density. Indeed, sample-goniometer alignment is a critical experimental factor and the overriding error source in XRR density determination. With commercial single-wavelength X-ray reflectometers, alignment is difficult to control and strongly depends on the operator. In the present work, the contribution of misalignment on density evaluation error is discussed, and a novel procedure (named XRR-density evaluation or XRR-DE method) to minimize the problem will be presented. The method allows to overcome the alignment step through the extrapolation of the correct density value from appropriate non-specular XRR data sets. This procedure is operator independent and suitable for commercial single-wavelength X-ray reflectometers. To test the XRR-DE method, single crystals of TiO 2 and SrTiO 3 were used. In both cases the determined densities differed from the nominal ones less than 5.5%. Thus, the XRR-DE method can be successfully applied to evaluate the density of thin films for which only optical reflectivity is today used. The advantage is that this method can be considered thickness independent.

36 CFR 67.4 - Certifications of historic significance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... district; (4) Current photographs of property; photographs of the building and its site and landscape... being revised to expand its significance, or that the SHPO is planning to nominate the property or the...

Association, effects and validation of polymorphisms within the NCAPG - LCORL locus located on BTA6 with feed intake, gain, meat and carcass traits in beef cattle

USDA-ARS?s Scientific Manuscript database

Background: In a previously reported genome-wide association study based on a high-density bovine SNP genotyping array, 8 SNP were nominally associated (P

White ash (Fraxinus americana L.) survival and growth in unmanaged upland forests

Treesearch

Jeffery S. Ward

1997-01-01

Crown class and diameter of 704 white ash (Fraxinus americana L.) > 0.5 inches dbh have been monitored at 10-yr intervals since 1927. Nominal stand age was 25 years in 1927. Although the density of white ash in the upper canopy declined from 14/acre to 3/acre between stand ages 25 through 85, the proportion of the upper canopy comprised by white...

Possible origin and roles of nano-porosity in ZrO2 scales for hydrogen pick-up in Zr alloys

NASA Astrophysics Data System (ADS)

Lindgren, Mikaela; Geers, Christine; Panas, Itai

2017-08-01

A mechanistic understanding of Wagnerian build-up and subsequent non-Wagnerian break-down of barrier oxide upon oxidation of zirconium alloys by water is reiterated. Hydrogen assisted build-up of nano-porosity is addressed. Growth of sub-nanometer wide stalactitic pores owing to increasing aggregation of neutral oxygen vacancies offering a means to permeate hydrogen into the alloy is explored by density functional theory. The Wagnerian channel utilizes charge separation allowing charged oxygen vacancies and electrons to move separately from nominal anode to nominal cathode. This process becomes increasingly controlled by the charging of the barrier oxide resulting in sub-parabolic rate law for oxide growth. The break-down of the barrier oxide is understood to be preceded by avalanching hydrogen pick-up in the alloy. Pore mediated diffusion allows water to effectively short circuit the barrier oxide.

[Phenotypic variability of the shell in Neritinidae (Gastropoda: Neritimorpha) in Puerto Rican rivers].

PubMed

Blanco, Juan Felipe; Tamayo, Silvana; Scatena, Frederick N

2014-04-01

Gastropods of the Neritinidae family exhibit an amphidromous life cycle and an impressive variability in shell coloration in Puerto Rican streams and rivers. Various nominal species have been described, but Neritina virginea [Linne 1758], N. punctulata [Lamarck 1816] and N. reclivata [Say 1822] are the only broadly reported. However, recent studies have shown that these three species are sympatric at the river scale and that species determination might be difficult due to the presence of intermediate color morphs. Individuals (8 751) were collected from ten rivers across Puerto Rico, and from various segments and habitats in Mameyes River (the most pristine island-wide) during three years (2000-2003), and they were assigned to one of seven phenotypes corresponding to nominal species and morphs (non-nominal species). The "axial lines and dots" morph corresponding to N. reclivata was the most frequent island-wide, while the patelliform N. punctulata was scant, but the only found in headwater reaches. The "yellowish large tongues" phenotype, typical of N. virginea s.s. was the most frequent in the river mouth. The frequency of secondary phenotypes varied broadly among rivers, along the rivers, and among habitats, seemly influenced by salinity and predation gradients. The occurrence of individuals with coloration shifts after predation injuries, suggests phenotypic plasticity in the three nominal species, and urges for the use of molecular markers to unravel the possible occurrence of a species complex, and to understand the genetic basis of polymorphism. The longitudinal distribution of individual sizes, population density and egg capsules suggested the adaptive value of upstream migration, possibly to avoid marine predators.

An Evaluation of Quantitative Methods of Determining the Degree of Melting Experienced by a Chondrule

NASA Technical Reports Server (NTRS)

Nettles, J. W.; Lofgren, G. E.; Carlson, W. D.; McSween, H. Y., Jr.

2004-01-01

Many workers have considered the degree to which partial melting occurred in chondrules they have studied, and this has led to attempts to find reliable methods of determining the degree of melting. At least two quantitative methods have been used in the literature: a convolution index (CVI), which is a ratio of the perimeter of the chondrule as seen in thin section divided by the perimeter of a circle with the same area as the chondrule, and nominal grain size (NGS), which is the inverse square root of the number density of olivines and pyroxenes in a chondrule (again, as seen in thin section). We have evaluated both nominal grain size and convolution index as melting indicators. Nominal grain size was measured on the results of a set of dynamic crystallization experiments previously described, where aliquots of LEW97008(L3.4) were heated to peak temperatures of 1250, 1350, 1370, and 1450 C, representing varying degrees of partial melting of the starting material. Nominal grain size numbers should correlate with peak temperature (and therefore degree of partial melting) if it is a good melting indicator. The convolution index is not directly testable with these experiments because the experiments do not actually create chondrules (and therefore they have no outline on which to measure a CVI). Thus we had no means to directly test how well the CVI predicted different degrees of melting. Therefore, we discuss the use of the CVI measurement and support the discussion with X-ray Computed Tomography (CT) data.

Aerodynamic Improvements to Cargo Carrying Rail Cars due to Roof Modifications

NASA Astrophysics Data System (ADS)

Condie, Robert; Maynes, Daniel

2012-11-01

The aerodynamic drag associated with the transport of commodities by rail is becoming increasingly important as the cost of diesel fuel increases. We provide an assessment of the influence of the roof structure on aerodynamic performance of two dissimilar rail cars, namely automobile carrying cars and coal carrying cars. Currently, the roof material for automobile carrying rail cars is corrugated steel, with the corrugation aligned perpendicular to the direction of travel. Coal cars are currently left uncovered for loading convenience and on the return leg from the power plant are empty. Aerodynamic drag data have been obtained through wind tunnel testing on 1/29 scale models to understand the savings that may be realized by judicious modification to the tops of both these car types. For the automobile-carrying cars, testing is performed for the corrugated and smooth roof configurations. This modification alone has the potential of reducing the car drag coefficient by nominally 25%. A broader study is performed for the coal cars, with data being acquired for coal filled models, empty models, and several cover prototype configurations. The results reveal that implementation of a cover may yield reductions in the aerodynamic drag for both coal filled (nominally 7%) and empty coal cars (nominally 30%).

Transparent conducting oxide nanotubes

NASA Astrophysics Data System (ADS)

Alivov, Yahya; Singh, Vivek; Ding, Yuchen; Nagpal, Prashant

2014-09-01

Thin film or porous membranes made of hollow, transparent, conducting oxide (TCO) nanotubes, with high chemical stability, functionalized surfaces and large surface areas, can provide an excellent platform for a wide variety of nanostructured photovoltaic, photodetector, photoelectrochemical and photocatalytic devices. While large-bandgap oxide semiconductors offer transparency for incident light (below their nominal bandgap), their low carrier concentration and poor conductivity makes them unsuitable for charge conduction. Moreover, materials with high conductivity have nominally low bandgaps and hence poor light transmittance. Here, we demonstrate thin films and membranes made from TiO2 nanotubes heavily-doped with shallow Niobium (Nb) donors (up to 10%, without phase segregation), using a modified electrochemical anodization process, to fabricate transparent conducting hollow nanotubes. Temperature dependent current-voltage characteristics revealed that TiO2 TCO nanotubes, doped with 10% Nb, show metal-like behavior with resistivity decreasing from 6.5 × 10-4 Ωcm at T = 300 K (compared to 6.5 × 10-1 Ωcm for nominally undoped nanotubes) to 2.2 × 10-4 Ωcm at T = 20 K. Optical properties, studied by reflectance measurements, showed light transmittance up to 90%, within wavelength range 400 nm-1000 nm. Nb doping also improves the field emission properties of TCO nanotubes demonstrating an order of magnitude increase in field-emitter current, compared to undoped samples.

Hot-electron real-space transfer and longitudinal transport in dual AlGaN/AlN/{AlGaN/GaN} channels

NASA Astrophysics Data System (ADS)

Šermukšnis, E.; Liberis, J.; Matulionis, A.; Avrutin, V.; Ferreyra, R.; Özgür, Ü.; Morkoç, H.

2015-03-01

Real-space transfer of hot electrons is studied in dual-channel GaN-based heterostructure operated at or near plasmon-optical phonon resonance in order to attain a high electron drift velocity at high current densities. For this study, pulsed electric field is applied in the channel plane of a nominally undoped Al0.3Ga0.7N/AlN/{Al0.15Ga0.85N/GaN} structure with a composite channel of Al0.15Ga0.85N/GaN, where the electrons with a sheet density of 1.4 × 1013 cm-2, estimated from the Hall effect measurements, are confined. The equilibrium electrons are situated predominantly in the Al0.15Ga0.85N layer as confirmed by capacitance-voltage experiment and Schrödinger-Poisson modelling. The main peak of the electron density per unit volume decreases as more electrons occupy the GaN layer at high electric fields. The associated decrease in the plasma frequency induces the plasmon-assisted decay of non-equilibrium optical phonons (hot phonons) confirmed by the decrease in the measured hot-phonon lifetime from 0.95 ps at low electric fields down below 200 fs at fields of E \\gt 4 kV cm-1 as the plasmon-optical phonon resonance is approached. The onset of real-space transfer is resolved from microwave noise measurements: this source of noise dominates for E \\gt 8 kV cm-1. In this range of fields, the longitudinal current exceeds the values measured for a mono channel reference Al0.3Ga0.7N/AlN/GaN structure. The results are explained in terms of the ultrafast decay of hot phonons and reduced alloy scattering caused by the real-space transfer in the composite channel.

BeZnCdSe quantum-well ridge-waveguide laser diodes under low threshold room-temperature continuous-wave operation

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

Feng, Jijun; Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology; Akimoto, Ryoichi, E-mail: r-akimoto@aist.go.jp

2015-10-19

Low threshold current ridge-waveguide BeZnCdSe quantum-well laser diodes (LDs) have been developed by completely etching away the top p-type BeMgZnSe/ZnSe:N short-period superlattice cladding layer, which can suppress the leakage current that flows laterally outside of the electrode. The waveguide LDs are covered with a thick SiO{sub 2} layer and planarized with chemical-mechanical polishing and a reactive ion etching process. Room-temperature lasing under continuous-wave condition is achieved with the laser cavity formed by the cleaved waveguide facets coated with high-reflectivity dielectric films. For a 4 μm-wide green LD lasing around a wavelength of 535 nm, threshold current and voltage of 7.07 mA and 7.89 Vmore » are achieved for a cavity length of 300 μm, and the internal differential quantum efficiency, internal absorption loss, gain constant, and nominal transparency current density are estimated to be 27%, 4.09 cm{sup −1}, 29.92 (cm × μm)/kA and 6.35 kA/(cm{sup 2 }× μm), respectively. This compact device can realize a significantly improved performance with much lower threshold power consumption, which would benefit the potential application for ZnSe-based green LDs as light sources in full-color display and projector devices installed in consumer products such as pocket projectors.« less

Characteristics of the high-rate discharge capability of a nickel/metal hydride battery electrode

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

Geng, M.; Han, J.; Feng, F.

1999-10-01

The high rate discharge capability of the negative electrode in a Ni/MH battery is mainly determined by the charge transfer process at the interface between the metal hydride (MH) alloy powder and the electrolyte, and the mass transfer process in the bulk MH alloy powder. In this study, the anodic polarization curves of a MH electrode were measured and analyzed. An alloy of nominal composition Mm{sub 0.95}Ti{sub 0.05}Ni{sub 3.85}Co{sub 0.45}Mn{sub 0.35}Al{sub 0.35} was used as the negative electrode material. With increasing number of charge/discharge cycles, the MH alloy powders microcrack into particles several micrometers in diameter. The decrease in themore » MH alloy particle size results in an increase in both the activation surface area and the exchange current density of the MH alloy electrode. The electrode overpotentials of the MH electrode decreases with increasing number of cycles at a large value of anodic polarization current. The decrease in electrode overpotential leads to an increase in the high rate discharge capability of the MH electrode. By using the limiting current, the hydrogen diffusion coefficient in the MH alloy was estimated to be 1.2 x 10{sup {minus}11}cm{sup 2}s{sup {minus}1} assuming an average particle radius of 5 {micro}m.« less

A Mesh Refinement Study on the Impact Response of a Shuttle Leading-Edge Panel Finite Element Simulation

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Jackson, Karen E.; Lyle, Karen H.; Spellman, Regina L.

2006-01-01

A study was performed to examine the influence of varying mesh density on an LS-DYNA simulation of a rectangular-shaped foam projectile impacting the space shuttle leading edge Panel 6. The shuttle leading-edge panels are fabricated of reinforced carbon-carbon (RCC) material. During the study, nine cases were executed with all possible combinations of coarse, baseline, and fine meshes of the foam and panel. For each simulation, the same material properties and impact conditions were specified and only the mesh density was varied. In the baseline model, the shell elements representing the RCC panel are approximately 0.2-in. on edge, whereas the foam elements are about 0.5-in. on edge. The element nominal edge-length for the baseline panel was halved to create a fine panel (0.1-in. edge length) mesh and doubled to create a coarse panel (0.4-in. edge length) mesh. In addition, the element nominal edge-length of the baseline foam projectile was halved (0.25-in. edge length) to create a fine foam mesh and doubled (1.0-in. edge length) to create a coarse foam mesh. The initial impact velocity of the foam was 775 ft/s. The simulations were executed in LS-DYNA for 6 ms of simulation time. Contour plots of resultant panel displacement and effective stress in the foam were compared at four discrete time intervals. Also, time-history responses of internal and kinetic energy of the panel, kinetic and hourglass energy of the foam, and resultant contact force were plotted to determine the influence of mesh density.

Measurement of inflight shell areal density near peak velocity using a self backlighting technique

NASA Astrophysics Data System (ADS)

Pickworth, L. A.; Hammel, B. A.; Smalyuk, V. A.; MacPhee, A. G.; Scott, H. A.; Robey, H. F.; Landen, O. L.; Barrios, M. A.; Regan, S. P.; Schneider, M. B.; Hoppe, M., Jr.; Kohut, T.; Holunga, D.; Walters, C.; Haid, B.; Dayton, M.

2016-05-01

The growth of perturbations in inertial confinement fusion (ICF) capsules can lead to significant variation of inflight shell areal density (ρR), ultimately resulting in poor compression and ablator material mixing into the hotspot. As the capsule is accelerated inward, the perturbation growth results from the initial shock-transit through the shell and then amplification by Rayleigh-Taylor as the shell accelerates inwards. Measurements of ρR perturbations near peak implosion velocity (PV) are essential to our understanding of ICF implosions because they reflect the integrity of the capsule, after the inward acceleration growth is complete, of the actual shell perturbations including native capsule surface roughness and “isolated defects”. Quantitative measurements of shell-ρR perturbations in capsules near PV are challenging, requiring a new method with which to radiograph the shell. An innovative method, utilized in this paper, is to use the self-emission from the hotspot to “self- backlight” the shell inflight. However, with nominal capsule fills there is insufficient self-emission for this method until the capsule nears peak compression (PC). We produce a sufficiently bright continuum self-emission backlighter through the addition of a high-Z gas (∼ 1% Ar) to the capsule fill. This provides a significant (∼10x) increase in emission at hυ∼8 keV over nominal fills. “Self backlit” radiographs are obtained for times when the shock is rebounding from the capsule center, expanding out to meet the incoming shell, providing a means to sample the capsule optical density though only one side, as it converges through PV.

Exon definition as a potential negative force against intron losses in evolution.

PubMed

Niu, Deng-Ke

2008-11-13

Previous studies have indicated that the wide variation in intron density (the number of introns per gene) among different eukaryotes largely reflects varying degrees of intron loss during evolution. The most popular model, which suggests that organisms lose introns through a mechanism in which reverse-transcribed cDNA recombines with the genomic DNA, concerns only one mutational force. Using exons as the units of splicing-site recognition, exon definition constrains the length of exons. An intron-loss event results in fusion of flanking exons and thus a larger exon. The large size of the newborn exon may cause splicing errors, i.e., exon skipping, if the splicing of pre-mRNAs is initiated by exon definition. By contrast, if the splicing of pre-mRNAs is initiated by intron definition, intron loss does not matter. Exon definition may thus be a selective force against intron loss. An organism with a high frequency of exon definition is expected to experience a low rate of intron loss throughout evolution and have a high density of spliceosomal introns. The majority of spliceosomal introns in vertebrates may be maintained during evolution not because of potential functions, but because of their splicing mechanism (i.e., exon definition). Further research is required to determine whether exon definition is a negative force in maintaining the high intron density of vertebrates. This article was reviewed by Dr. Scott W. Roy (nominated by Dr. John Logsdon), Dr.Eugene V. Koonin, and Dr. Igor B. Rogozin (nominated by Dr. Mikhail Gelfand). For the full reviews,please go to the Reviewers' comments section.

Characterisation of SOL density fluctuations in front of the LHCD PAM launcher in Tore

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

Oosako, T.; Ekedahl, A.; Goniche, M.

2011-12-23

The density fluctuations, modified by Lower Hybrid Wave (LHW), is analyzed in Tore Supra with reference to the injected LHW power, density and the gap between LCFS (Last Closed Flux Surface) and the PAM (passive-active-multijunction) launcher. The density fluctuations are measured with RF probes installed at the PAM launcher front. A density scan at nominal toroidal field (3.8 T) shows that the fluctuations rate stays nearly constant ({approx}50%) for <3.5x10{sup 19}m{sup -3} and with LHW power up to 2MW. However, when increasing the density above <{approx}4.2x10{sup 19}m{sup -3}, using strong gas puffing, the fluctuation rate increases to >70%more » and is characterized by strong negative spikes, with typical frequency >100kHz. These are most likely originating from acceleration of electrons in the LHW near field due to parasitic absorption, as evidenced on the IR images, showing hot spots on the side limiters.« less

Quantitative assessment of scatter correction techniques incorporated in next generation dual-source computed tomography

NASA Astrophysics Data System (ADS)

Mobberley, Sean David

Accurate, cross-scanner assessment of in-vivo air density used to quantitatively assess amount and distribution of emphysema in COPD subjects has remained elusive. Hounsfield units (HU) within tracheal air can be considerably more positive than -1000 HU. With the advent of new dual-source scanners which employ dedicated scatter correction techniques, it is of interest to evaluate how the quantitative measures of lung density compare between dual-source and single-source scan modes. This study has sought to characterize in-vivo and phantom-based air metrics using dual-energy computed tomography technology where the nature of the technology has required adjustments to scatter correction. Anesthetized ovine (N=6), swine (N=13: more human-like rib cage shape), lung phantom and a thoracic phantom were studied using a dual-source MDCT scanner (Siemens Definition Flash. Multiple dual-source dual-energy (DSDE) and single-source (SS) scans taken at different energy levels and scan settings were acquired for direct quantitative comparison. Density histograms were evaluated for the lung, tracheal, water and blood segments. Image data were obtained at 80, 100, 120, and 140 kVp in the SS mode (B35f kernel) and at 80, 100, 140, and 140-Sn (tin filtered) kVp in the DSDE mode (B35f and D30f kernels), in addition to variations in dose, rotation time, and pitch. To minimize the effect of cross-scatter, the phantom scans in the DSDE mode was obtained by reducing the tube current of one of the tubes to its minimum (near zero) value. When using image data obtained in the DSDE mode, the median HU values in the tracheal regions of all animals and the phantom were consistently closer to -1000 HU regardless of reconstruction kernel (chapters 3 and 4). Similarly, HU values of water and blood were consistently closer to their nominal values of 0 HU and 55 HU respectively. When using image data obtained in the SS mode the air CT numbers demonstrated a consistent positive shift of up to 35 HU with respect to the nominal -1000 HU value. In vivo data demonstrated considerable variability in tracheal, influenced by local anatomy with SS mode scanning while tracheal air was more consistent with DSDE imaging. Scatter effects in the lung parenchyma differed from adjacent tracheal measures. In summary, data suggest that enhanced scatter correction serves to provide more accurate CT lung density measures sought to quantitatively assess the presence and distribution of emphysema in COPD subjects. Data further suggest that CT images, acquired without adequate scatter correction, cannot be corrected by linear algorithms given the variability in tracheal air HU values and the independent scatter effects on lung parenchyma.

Solvent Hold Tank Sample Results for MCU-16-701-702-703: May 2016 Monthly Sample and MCU-16-710-711-712: May 2016 Superwashed Sample

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

Fondeur, F. F.; Jones, D. H.

The Savannah River National Laboratory (SRNL) received one set of Solvent Hold Tank (SHT) samples (MCU-16-701, MCU-16-702 and MCU-16-703), pulled on 05/23/2016, and another set of SHT samples (MCU-16-710, MCU-16-711, and MCU-16-712) were pulled on 05/28/2016 after the solvent was superwashed with 300 mM sodium hydroxide for analysis. Samples MCU-16-701, MCU-16-702, and MCU-16-703 were combined into one sample (MCU-16-701-702-703) and samples MCU-16-710, MCU- 16-711, and MCU-16-712 were combined into one sample (MCU-16-710-711-712). Of the two composite samples MCU-16-710-711-712 represents the current chemical state of the solvent at MCU. All analytical conclusions are based on the chemical analysis of MCU-16-710-711-712. Theremore » were no chemical differences between MCU-16-701-702-703 and superwashed MCU-16-710-711-712. Analysis of the composited sample MCU-16-710-712-713 indicated the Isopar™L concentration is above its nominal level (102%). The modifier (CS-7SB) is 16% below its nominal concentration, while the TiDG and MaxCalix concentrations are at and above their nominal concentrations, respectively. The TiDG level has begun to decrease, and it is 7% below its nominal level as of May 28, 2016. Based on this current analysis, the levels of TiDG, Isopar™L, MaxCalix, and modifier are sufficient for continuing operation but are expected to decrease with time. Periodic characterization and trimming additions to the solvent are recommended.« less

75 FR 77617 - Notice Requesting Nominations for the Marine Protected Areas Federal Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-13

... characteristics. The membership reflects the Department's commitment to attaining balance and diversity. The full text of the Advisory Committee Charter and its current membership can be viewed at the Agency's Web...

[Interdisciplinary AWMF guideline for the treatment of primary antibody deficiencies].

PubMed

Krudewig, J; Baumann, U; Bernuth von, H; Borte, M; Burkhard-Meier, U; Dueckers, G; Foerster-Waldl, E; Franke, K; Habermehl, P; Hönig, M; Kern, W; Kösters, K; Kugel, K; Lehrnbecher, T; Liese, J; Marks, R; Müller, G A; Müller, R; Nadal, D; Peter, H-H; Pfeiffer-Kascha, D; Schneider, M; Sitter, H; Späth, P; Wahn, V; Welte, T; Niehues, T

2012-10-01

Currently, management of antibody deficient patients differs significantly among caregivers. Evidence and consensus based (S3) guidelines for the treatment of primary antibody deficiencies were developed to improve the management of these patients. Based on a thorough analysis of current evidence (systematic literature search in PubMed; deadline November 2011) 14 recommendations were finalized during a consensus meeting in Frankfurt in November 2011 using structured consensus methods (nominal group technique). Experts were nominated by their scientific societies/patient initiatives (Tab. 1). The guidelines focus on indication, practical issues and monitoring of immunoglobulin replacement therapy as well as on different routes of administration. Furthermore recommendations regarding supportive measures such as antiinfective therapy, vaccinations and physiotherapy are given. Combining literature evidence and experience of caregivers within this evidence and consensus based guidelines offers the chance to improve the quality of care for anti-body deficient patients. © Georg Thieme Verlag KG Stuttgart · New York.

The brightness temperature of Venus and the absolute flux-density scale at 608 MHz.

NASA Technical Reports Server (NTRS)

Muhleman, D. O.; Berge, G. L.; Orton, G. S.

1973-01-01

The disk temperature of Venus was measured at 608 MHz near the inferior conjunction of 1972, and a value of 498 plus or minus 33 K was obtained using a nominal CKL flux-density scale. The result is consistent with earlier measurements, but has a much smaller uncertainty. Our theoretical model prediction is larger by a factor of 1.21 plus or minus 0.09. This discrepancy has been noticed previously for frequencies below 1400 MHz, but was generally disregarded because of the large observational uncertainties. No way could be found to change the model to produce agreement without causing a conflict with well-established properties of Venus. Thus it is suggested that the flux-density scale may require an upward revision, at least near this frequency, in excess of what has previously been considered likely.

Validation Tests of a Non-Nuclear Combined Asphalt and Soil Density Gauge

DTIC Science & Technology

2014-04-01

limit if applicable. This approach was considered as if this device was to be used on a construction project for quality control where the material...military contingency construction activities, because they are not sufficiently accurate compared to the NDG for quality control use in permanent...binder. Nominal asphalt content with water included was 5.2. m Average results from producer’s Quality Control (QC) testing. The list of instruments

Futures of Space Technology Frontiers of the Responsibly Imaginable

DTIC Science & Technology

2006-09-01

Nominal Power Densities • ZPE ……………………..E108 X Chemical •Anti-Matter/Positrons….. E10 X Chemical • Fission/Fusion………….. E6 X Chemical • Isomers…………………. E5...Efficiency [KW/KG] Fuel Cells • “On-Site” H2 Generation vice Storage [Zinc,….] • Room Temperature S-C • Tapping ZPE • Controlled Nuclear Isomer Release

Fabrication of two one-fifth scale fiber composite flywheels

NASA Astrophysics Data System (ADS)

1980-04-01

Two fiber composite flywheel rotors were fabricated. These flywheels are scaled down versions of two automotive flywheels built for Sandia Laboratories. The flywheels store a maximum of 0.97 kWh of kinetic energy. Energy density is 87 Wh/kg at the maximum operating speed of 56,000 rpm. The nominal flywheel dimensions are 35 cm diameter by 13 cm axial height. The weight of the flywheel rotor assembly is 11.16 kg.

Geodynamic stability of the primary in the binary asteroid system 65803 Didymos

NASA Astrophysics Data System (ADS)

Barnouin, Olivier S.; Maurel, Clara; Richardson, Derek C.; Ballouz, Ronald-Louis; Schwartz, Stephen; Michel, Patrick

2015-11-01

The moon of the near-Earth binary asteroid 65803 Didymos is the target of the Asteroid Impact and Deflection Assessment (AIDA) mission. This mission is a joint concept between NASA and ESA to investigate the effectiveness of a kinetic impactor in deflecting an asteroid. The mission is composed of two components: the NASA-led Double Asteroid Redirect Test (DART) that will impact the Didymos moon, and the ESA-led Asteroid Impact Monitoring (AIM) mission that will characterize the Didymos system. In order to provide AIDA constraints on the physical character of the both objects in this binary system, we undertook preliminary numerical investigations to evaluate the stability of the shape of the primary using its rapid 2.26 h rotation. We modeled the primary as a rubble pile. Each model consisted of thousands of uniform rigid spheres collapsed together under their own gravity to form a spherical pile that was then carved to match the current radar-derived shape model of the primary, as well as other comparable shapes (e.g. asteroid 1999 KW4, spheres) that were scaled to match best estimates of the size of Didymos. Each model was given a starting rotation period of 6 h with the spin axis aligned to the pole. At each timestep the spin rate was increased by a small amount so that after about 1 million timesteps the spin would match the observed rotation of 2.26 h. We tested a range of bulk densities spanning the current observational uncertainty (mean 2.4 g/cc) using "gravel"-like material parameters that provide significant resistance to sliding and rolling. We find that at the upper range of the density uncertainty it is possible for Didymos to hold its shape and not lose mass at its nominal rotation period, without the need for cohesive forces. At lower densities or with smoother particles, significant shape change occurs and mass loss is possible. We conclude that based on the radar shape available at the time of this writing, Didymos is marginally stable as a rubble pile with bulk density close to 3 g/cc. Revisions to the radar shape in process may allow for stability at lower bulk densities without cohesion. These results suggest that the moon of Didymos may also not be heavily influenced by cohesion.

Post-Flight Assessment of Low Density Supersonic Decelerator Flight Dynamics Test 2 Simulation

NASA Technical Reports Server (NTRS)

Dutta, Soumyo; Bowes, Angela L.; White, Joseph P.; Striepe, Scott A.; Queen, Eric M.; O'Farrel, Clara; Ivanov, Mark C.

2016-01-01

NASA's Low Density Supersonic Decelerator (LDSD) project conducted its second Supersonic Flight Dynamics Test (SFDT-2) on June 8, 2015. The Program to Optimize Simulated Trajectories II (POST2) was one of the flight dynamics tools used to simulate and predict the flight performance and was a major tool used in the post-flight assessment of the flight trajectory. This paper compares the simulation predictions with the reconstructed trajectory. Additionally, off-nominal conditions seen during flight are modeled in the simulation to reconcile the predictions with flight data. These analyses are beneficial to characterize the results of the flight test and to improve the simulation and targeting of the subsequent LDSD flights.

Short- and Long-Term Musical Preferences: What Makes a Favourite Piece of Music?

ERIC Educational Resources Information Center

Lamont, Alexandra; Webb, Rebecca

2010-01-01

Within the growing field of music preferences, little is currently known about the concept of a favourite piece of music. The current study explores listeners' nominated favourite pieces of music over short and longer time-spans, combining diary and interview methods to uncover what a favourite means, how stable it is, and what factors influence…

Safety and Performance Analysis of the Non-Radar Oceanic/Remote Airspace In-Trail Procedure

NASA Technical Reports Server (NTRS)

Carreno, Victor A.; Munoz, Cesar A.

2007-01-01

This document presents a safety and performance analysis of the nominal case for the In-Trail Procedure (ITP) in a non-radar oceanic/remote airspace. The analysis estimates the risk of collision between the aircraft performing the ITP and a reference aircraft. The risk of collision is only estimated for the ITP maneuver and it is based on nominal operating conditions. The analysis does not consider human error, communication error conditions, or the normal risk of flight present in current operations. The hazards associated with human error and communication errors are evaluated in an Operational Hazards Analysis presented elsewhere.

49 CFR 1141.1 - Procedures to calculate interest rates.

Code of Federal Regulations, 2011 CFR

2011-10-01

... compounding period shall run from the date the unlawful charge is paid to the last day of the current calendar... in an effective rate in excess of the nominal rate. Under this “exponential” approach, the total...

Do genetic modifiers of high-density lipoprotein cholesterol and triglyceride levels also modify their response to a lifestyle intervention in the setting of obesity and type-2 diabetes mellitus?: The Action for Health in Diabetes (Look AHEAD) study.

PubMed

Huggins, Gordon S; Papandonatos, George D; Erar, Bahar; Belalcazar, L Maria; Brautbar, Ariel; Ballantyne, Christie; Kitabchi, Abbas E; Wagenknecht, Lynne E; Knowler, William C; Pownall, Henry J; Wing, Rena R; Peter, Inga; McCaffery, Jeanne M

2013-08-01

High-density lipoprotein cholesterol (HDL-C) and triglycerides are cardiovascular risk factors susceptible to lifestyle behavior modification and genetics. We hypothesized that genetic variants identified by genome-wide association studies as associated with HDL-C or triglyceride levels modify 1-year treatment response to an intensive lifestyle intervention, relative to a usual care of diabetes mellitus support and education. We evaluated 82 single-nucleotide polymorphisms, which represent 31 loci demonstrated by genome-wide association studies to be associated with HDL-C and triglycerides, in 3561 participants who consented for genetic studies and met eligibility criteria. Variants associated with higher baseline HDL-C levels, cholesterol ester transfer protein (CETP) rs3764261 and hepatic lipase (LIPC) rs8034802, were found to be associated with HDL-C increases with intensive lifestyle intervention (P=0.0038 and 0.013, respectively) and had nominally significant treatment interactions (P=0.047 and 0.046, respectively). The fatty acid desaturase-2 rs1535 variant, associated with low baseline HDL-C (P=0.017), was associated with HDL-C increases with intensive lifestyle intervention (0.0037) and had a nominal treatment interaction (P=0.035). Apolipoprotein B (rs693) and LIPC (rs8034802) single-nucleotide polymorphisms showed nominally significant associations with HDL-C and triglyceride changes with intensive lifestyle intervention and a treatment interaction (P<0.05). Phosphatidylglycerophosphate synthase-1 single-nucleotide polymorphisms (rs4082919) showed the most significant triglyceride treatment interaction in the full cohort (P=0.0009). This is the first study to identify genetic variants modifying lipid responses to a randomized lifestyle behavior intervention in overweight or obese individuals with diabetes mellitus. The effects of genetic factors on lipid changes may differ from the effects on baseline lipids and are modifiable by behavioral intervention.

Auroral currents during the magnetic storm of November 8 and 9, 1991 - Observations from the Upper Atmosphere Research Satellite Particle Environment Monitor

NASA Technical Reports Server (NTRS)

Anderson, B. J.; Potemra, T. A.; Bythrow, P. F.; Zanetti, L. J.; Holland, D. B.; Winningham, J. D.

1993-01-01

The development of the intensity and location of Birkeland currents associated with the magnetic storm of November 8-9, 1991 is reported. Total Birkeland currents exceed 30 MA, more than six times nominal values, indicating Joule heating of about 3 x lO exp 12 W. Birkeland currents below 50 deg, polar cap currents indicative of antisunward convection, and cusp particle signatures of southward IMF all persist at least eight hours into recovery phase of the storm.

Advanced Divertor Design and Application under Modern Superconducting Tokamak Constraints

NASA Astrophysics Data System (ADS)

Covele, Brent; Kotschenreuther, Mike; Mahajan, Swadesh; Valanju, Prashant

2013-10-01

With current ITER projections already predicting divertor exhaust heat loads in the 5-10 MW/m2 range, i.e. at the maximum tolerance, it is clear that the divertor heat load problem will only be exacerbated for future superconducting tokamaks, as well as perhaps some modern tokamaks today. Thus, an advanced divertor, such as the X-Divertor (XD), Super-X Divertor (SXD), or Snowflake (SF) will become a virtual necessity to reduce incident heat flux at the target plates. Using the 2D magnetic equilibrium code CORSICA, we explore the possibilities of creating an advanced divertor for a next-generation superconducting tokamak (Ip = 15 MA, BT = 5.3 T, R = 6.2 m) under nominal engineering constraints. Advanced divertors were achieved with no in-vessel PF coils, PF current densities below 30 MA/m2, and vertical maintenance access, all of which are favorable conditions for tokamaks today. Both the XD and SF divertors are readily achievable while maintaining core plasma performance, and the advantages and disadvantages of each are discussed in turn. Some thought is given as to how the divertor cassette will need to be modified to accommodate advanced divertors. Work supported under US-DOE projects DE-FG02-04ER54742 and DE-FG02-04ER54754.

Development and qualification of a bulk tungsten divertor row for JET

NASA Astrophysics Data System (ADS)

Mertens, Ph.; Altmann, H.; Hirai, T.; Philipps, V.; Pintsuk, G.; Rapp, J.; Riccardo, V.; Schweer, B.; Uytdenhouwen, I.; Samm, U.

2009-06-01

A bulk tungsten divertor row has been developed in the frame of the ITER-like Wall project at JET. It consists of 96 tiles grouped in 48 modules around the torus. The outer strike point is located on those tiles for most of the ITER-relevant, high triangularity plasmas. High power loads (locally up to 10-20 MW/m 2) and erosion rates are expected, even a risk of melting, especially with the transients or ELM loads. These are demanding conditions for an inertially cooled design as prescribed. A lamella design has been selected for the tungsten, arranged to control the eddy and halo current flows. The lamellae must also withstand high temperature gradients (2200 to 220 °C over 40 mm height), without overheating the supporting carrier (600-700 °C maximum). As a consequence of the tungsten emissivity, the radiative cooling drops appreciably in comparison with the current CFC tiles, calling for interleaved plasma scenarios in terms of performance. The compromise between shadowing and power handling is discussed, as well as the consequences for operation. Prototypes have been exposed in TEXTOR and in an electron beam facility (JUDITH-2) to the nominal power density of 7 MW/m 2 for 10 s and, in addition, to higher loads leading to surface temperatures above 2000 °C.

Preventable coronary heart disease events from control of cardiovascular risk factors in US adults with diabetes (projections from utilizing the UKPDS risk engine).

PubMed

Wong, Nathan D; Patao, Christopher; Malik, Shaista; Iloeje, Uchenna

2014-04-15

Type 2 diabetes mellitus (T2DM) carries significant risks for coronary heart disease (CHD). We examined the potential US population impact of single and composite risk factor control. Among US adults with diagnosed T2DM aged≥30 years in the National Health and Nutrition Examination Survey 2007 to 2012, we assessed CHD events preventable using the United Kingdom Prospective Diabetes Study CHD risk engine. We examined in all those not at goal the impact of statistical control of smoking, glycated hemoglobin, systolic blood pressure, and total and high-density lipoprotein cholesterol, according to the predefined criteria setting risk factors at different levels of control representing (1) "All to Goal," (2) at "Nominal Control," or (3) at "Aggressive Control." Preventable CHD events represented the difference between the number of events estimated from the control of these risk factors versus current levels of the risk factors. Of 606 men (representing 6.2 million) and 603 women (6.3 million) with DM and no previous CHD, 1.3 million men and 0.7 million women would develop a CHD event within 10 years if left uncontrolled. Controlling all risk factors to goal was projected to prevent 35% and 45% of CHD events in men and women, respectively. Nominal risk factor control was projected to prevent 36% and 38% and aggressive control 51% and 61% of CHD events, respectively. In conclusion, a significant proportion of CHD events in adults with T2DM could be prevented from composite control of risk factors often not at goal. Copyright © 2014 Elsevier Inc. All rights reserved.

The influence of Pb and Ag doping on the Jc(H,T) dependence and the mechanical properties of Bi-2212 textured rods

NASA Astrophysics Data System (ADS)

Sotelo, A.; Madre, M. A.; Diez, J. C.; Rasekh, Sh; Angurel, L. A.; Martínez, E.

2009-03-01

Textured rods of Bi-2212 based materials with nominal compositions Bi2Sr2CaCu2O8+δ, Bi2Sr2CaCu2O8+δ+1 wt% Ag, Bi1.6Pb0.4Sr2CaCu2O8+δ, and Bi1.6Pb0.4Sr2CaCu2O8+δ+3 wt% Ag were fabricated using a laser floating zone (LFZ) melting method. The electrical, magnetic, and mechanical properties of the resulting rods after annealing were characterized. Pb doping results in the decrease of the transport critical current density, Jc,t (from 4.4 × 107 to 6 × 106 A m-2 at 65 K and self-field) as well as in the worsening of the mechanical properties, by about 35% compared to the undoped samples. In contrast, Ag doping results in the improvement of both the critical current density and mechanical strength. In this regard we have observed an increase of Jc,t (65 K) from 4.4 × 107 for Bi-2212 to 7.2 × 107 A m-2 for Bi-2212/Ag and from 6 × 106 for Bi(Pb)-2212 to 8 × 106 A m-2 for Bi(Pb)-2212/Ag. These described effects are related to the microstructural observations, since Pb doping dramatically reduces the texture while Ag doping improves it. Moreover, for samples with Ag addition, an intergrowth of Bi-2223 inside the Bi-2212 grains is observed, which would explain the improved superconducting properties of these samples.

Chronic effect of cadmium in sediments on colonization by benthic marine organisms: An evaluation of the role of interstitial cadmium and acid-volatile sulfide in biological availability

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

Hansen, D.J.; Berry, W.J.; Benyi, S.J.

1996-12-01

The role of interstitial cadmium and acid-volatile sulfide (AVS) in controlling the bioavailability of sediment-associated metal was examined using the chronic saltwater benthic colonization test. Sediments were spiked to achieve nominal cadmium/AVS molar ratios of 0.0 (control), 0.1, 0.8, and 3.0 in this 118-d test. Oxidation of AVS in the surficial 2.4 cm within 2 to 4 weeks resulted in sulfide profiles similar to those occurring naturally in local sediments. In the nominal 0.1 cadmium/AVS treatment measured simultaneously extracted metal (SEM{sub Cd}) was always less than AVS. Interstitial cadmium concentrations were less than those likely to cause biological effects. Nomore » significant biological effects were detected. In the nominal 0.8 cadmium/AVS treatment, measured SEM{sub Cd} commonly exceeded AVS in the surficial 2.4 cm of sediment. Interstitial cadmium concentrations were of likely toxicological significance to highly sensitive species. Shifts in the presence or absence over all taxa, and fewer macrobenthic polychaetes (Mediomastus ambiseta, Streblospio benedicti, and Podarke obscurea) and unidentified meiofaunal nematodes, were observed. In the nominal 3.0 cadmium/AVS treatment, concentrations of SEM{sub Cd} were always greater than AVS throughout the sediment column. Interstitial cadmium ranged from 28,000 to 174,000 {micro}g/L. In addition to the effects above, the sediments were colonized by fewer macrobenthic species, polychaete species, and harpacticoids; had lower densities of diatoms; lacked bivalve molluscs; and exhibited other impacts. Over all treatments, the observed biological responses were consistent with SEM{sub Cd}/AVS ratios in surficial sediments and interstitial water cadmium concentrations.« less

Simulated Tip Rub Testing of Low-Density Metal Foam

NASA Technical Reports Server (NTRS)

Bowman, Cheryl L.; Jones, Michael G.

2009-01-01

Preliminary acoustic studies have indicated that low-density, open-cell, metal foams may be suitable acoustic liner material for noise suppression in high by-pass engines. Metal foam response under simulated tip rub conditions was studied to assess whether its durability would be sufficient for the foam to serve both as a rub strip above the rotor as well as an acoustic treatment. Samples represented four metal alloys, nominal cell dimensions ranging from 60 to 120 cells per inch (cpi), and relative densities ranging from 3.4 to 10 percent. The resulting rubbed surfaces were relatively smooth and the open cell structure of the foam was not adversely affected. Sample relative density appeared to have significant influence on the forces induced by the rub event. Acoustic responses of various surface preparations were measured using a normal incidence tube. The results of this study indicate that the foam s open-cell structure was retained after rubbing and that the acoustic absorption spectra variation was minimal.

The Influence of Mesh Density on the Impact Response of a Shuttle Leading-Edge Panel Finite Element Simulation

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Fasanella, Edwin L.; Lyle, Karen H.; Spellman, Regina L.

2004-01-01

A study was performed to examine the influence of varying mesh density on an LS-DYNA simulation of a rectangular-shaped foam projectile impacting the space shuttle leading edge Panel 6. The shuttle leading-edge panels are fabricated of reinforced carbon-carbon (RCC) material. During the study, nine cases were executed with all possible combinations of coarse, baseline, and fine meshes of the foam and panel. For each simulation, the same material properties and impact conditions were specified and only the mesh density was varied. In the baseline model, the shell elements representing the RCC panel are approximately 0.2-in. on edge, whereas the foam elements are about 0.5-in. on edge. The element nominal edge-length for the baseline panel was halved to create a fine panel (0.1-in. edge length) mesh and doubled to create a coarse panel (0.4-in. edge length) mesh. In addition, the element nominal edge-length of the baseline foam projectile was halved (0.25-in. edge length) to create a fine foam mesh and doubled (1.0- in. edge length) to create a coarse foam mesh. The initial impact velocity of the foam was 775 ft/s. The simulations were executed in LS-DYNA version 960 for 6 ms of simulation time. Contour plots of resultant panel displacement and effective stress in the foam were compared at five discrete time intervals. Also, time-history responses of internal and kinetic energy of the panel, kinetic and hourglass energy of the foam, and resultant contact force were plotted to determine the influence of mesh density. As a final comparison, the model with a fine panel and fine foam mesh was executed with slightly different material properties for the RCC. For this model, the average degraded properties of the RCC were replaced with the maximum degraded properties. Similar comparisons of panel and foam responses were made for the average and maximum degraded models.

Aerodynamic Models for the Low Density Supersonic Declerator (LDSD) Supersonic Flight Dynamics Test (SFDT)

NASA Technical Reports Server (NTRS)

Van Norman, John W.; Dyakonov, Artem; Schoenenberger, Mark; Davis, Jody; Muppidi, Suman; Tang, Chun; Bose, Deepak; Mobley, Brandon; Clark, Ian

2015-01-01

An overview of pre-flight aerodynamic models for the Low Density Supersonic Decelerator (LDSD) Supersonic Flight Dynamics Test (SFDT) campaign is presented, with comparisons to reconstructed flight data and discussion of model updates. The SFDT campaign objective is to test Supersonic Inflatable Aerodynamic Decelerator (SIAD) and large supersonic parachute technologies at high altitude Earth conditions relevant to entry, descent, and landing (EDL) at Mars. Nominal SIAD test conditions are attained by lifting a test vehicle (TV) to 36 km altitude with a large helium balloon, then accelerating the TV to Mach 4 and and 53 km altitude with a solid rocket motor. The first flight test (SFDT-1) delivered a 6 meter diameter robotic mission class decelerator (SIAD-R) to several seconds of flight on June 28, 2014, and was successful in demonstrating the SFDT flight system concept and SIAD-R. The trajectory was off-nominal, however, lofting to over 8 km higher than predicted in flight simulations. Comparisons between reconstructed flight data and aerodynamic models show that SIAD-R aerodynamic performance was in good agreement with pre-flight predictions. Similar comparisons of powered ascent phase aerodynamics show that the pre-flight model overpredicted TV pitch stability, leading to underprediction of trajectory peak altitude. Comparisons between pre-flight aerodynamic models and reconstructed flight data are shown, and changes to aerodynamic models using improved fidelity and knowledge gained from SFDT-1 are discussed.

Aerodynamic Models for the Low Density Supersonic Decelerator (LDSD) Test Vehicles

NASA Technical Reports Server (NTRS)

Van Norman, John W.; Dyakonov, Artem; Schoenenberger, Mark; Davis, Jody; Muppidi, Suman; Tang, Chun; Bose, Deepak; Mobley, Brandon; Clark, Ian

2016-01-01

An overview of aerodynamic models for the Low Density Supersonic Decelerator (LDSD) Supersonic Flight Dynamics Test (SFDT) campaign test vehicle is presented, with comparisons to reconstructed flight data and discussion of model updates. The SFDT campaign objective is to test Supersonic Inflatable Aerodynamic Decelerator (SIAD) and large supersonic parachute technologies at high altitude Earth conditions relevant to entry, descent, and landing (EDL) at Mars. Nominal SIAD test conditions are attained by lifting a test vehicle (TV) to 36 km altitude with a helium balloon, then accelerating the TV to Mach 4 and 53 km altitude with a solid rocket motor. Test flights conducted in June of 2014 (SFDT-1) and 2015 (SFDT-2) each successfully delivered a 6 meter diameter decelerator (SIAD-R) to test conditions and several seconds of flight, and were successful in demonstrating the SFDT flight system concept and SIAD-R technology. Aerodynamic models and uncertainties developed for the SFDT campaign are presented, including the methods used to generate them and their implementation within an aerodynamic database (ADB) routine for flight simulations. Pre- and post-flight aerodynamic models are compared against reconstructed flight data and model changes based upon knowledge gained from the flights are discussed. The pre-flight powered phase model is shown to have a significant contribution to off-nominal SFDT trajectory lofting, while coast and SIAD phase models behaved much as predicted.

77 FR 73684 - Notice of Extension of Call for Nominations for the Advisory Committee on the Medical Uses of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-11

..., recentness, and type of setting for nuclear cardiology. The cover letter should describe the nominee's current involvement with nuclear cardiology and express the nominee's interest in the position. FOR...

Thomson scattering density calibration by Rayleigh and rotational Raman scattering on NSTX.

PubMed

LeBlanc, B P

2008-10-01

The multipoint Thomson scattering diagnostic measures the profiles of the electron temperature T(e)(R) and density n(e)(R) on the horizontal midplane of NSTX. Normal operation makes use of Rayleigh scattering in nitrogen or argon to derive the density profile. While the Rayleigh scattering n(e)(R) calibration has been validated by comparison to other density measurements and through its correlation with plasma phenomena, it does require dedicated detectors at the laser wavelength in this filter polychromator based diagnostic. The presence of dust and/or stray laser light precludes routine use of these dedicated spectral channels for Thomson scattering measurement. Hence it is of interest to investigate the use of Raman scattering in nitrogen for the purpose of density calibration since it could free up detection equipment, which could then be used for the instrumentation of additional radial channels. In this paper the viewing optics "geometrical factor" profiles obtained from Rayleigh and Raman scattering are compared. While both techniques agree nominally, residual effects on the order of 10% remain and will be discussed.

NASA Occupant Protection Standards Development

NASA Technical Reports Server (NTRS)

Somers, Jeffrey T.; Gernhardt, Michael A.; Lawrence, Charles

2011-01-01

Current National Aeronautics and Space Administration (NASA) occupant protection standards and requirements are based on extrapolations of biodynamic models, which were based on human tests performed under pre-Space Shuttle human flight programs where the occupants were in different suit and seat configurations than is expected for the Multi Purpose Crew Vehicle (MPCV) and Commercial Crew programs. As a result, there is limited statistical validity to the occupant protection standards. Furthermore, the current standards and requirements have not been validated in relevant spaceflight suit, seat configurations or loading conditions. The objectives of this study were to develop new standards and requirements for occupant protection and rigorously validate these new standards with sub-injurious human testing. To accomplish these objectives we began by determining which critical injuries NASA would like to protect for. We then defined the anthropomorphic test device (ATD) and the associated injury metrics of interest. Finally, we conducted a literature review of available data for the Test Device for Human Occupant Restraint New Technology (THOR-NT) ATD to determine injury assessment reference values (IARV) to serve as a baseline for further development. To better understand NASA s environment, we propose conducting sub-injurious human testing in spaceflight seat and suit configurations with spaceflight dynamic loads, with a sufficiently high number of subjects to validate no injury during nominal landing loads. In addition to validate nominal loads, the THOR-NT ATD will be tested in the same conditions as the human volunteers, allowing correlation between human and ATD responses covering the Orion nominal landing environment and commercial vehicle expected nominal environments. All testing will be conducted without the suit and with the suit to ascertain the contribution of the suit to human and ATD responses. In addition to the testing campaign proposed, additional data analysis is proposed to mine existing human injury and response data from other sources, including military volunteer testing, automotive Crash Injury Research Engineering Network (CIREN), and IndyCar impact and injury data. These data sources can allow a better extrapolation of the ATD responses to off-nominal conditions above the nominal range that can safely be tested. These elements will be used to develop injury risk functions for each of the injury metrics measured from the ATD. These risk functions would serve as the basis for the NASA standards. Finally, we propose defining standard test methodology for evaluating future spacecraft designs against the IARVs, including developing a star-rating system to allow crew safety comparisons between vehicles.

Local ionospheric electron density reconstruction from simultaneous ground-based GNSS and ionosonde measurements

NASA Astrophysics Data System (ADS)

Stankov, S. M.; Warnant, R.; Stegen, K.

2009-04-01

The purpose of the LIEDR (Local Ionospheric Electron Density Reconstruction) system is to acquire and process data from simultaneous ground-based GNSS TEC and digital ionosonde measurements, and subsequently to deduce the vertical electron density distribution in the local ionosphere. LIEDR is primarily designed to operate in real time for service applications, and, if sufficient data from solar and geomagnetic observations are available, to provide short-term forecast as well. For research applications and further development of the system, a post-processing mode of operation is also envisaged. In essence, the reconstruction procedure consists in the following. The high-precision ionosonde measurements are used for directly obtaining the bottom part of the electron density profile. The ionospheric profiler for the lower side (i.e. below the density peak height, hmF2) is based on the Epstein layer functions using the known values of the critical frequencies, foF2 and foE, and the propagation factor, M3000F2. The corresponding bottom-side part of the total electron content is calculated from this profile and is then subtracted from the GPS TEC value in order to obtain the unknown portion of the TEC in the upper side (i.e. above the hmF2). Ionosonde data, together with the simultaneously-measured TEC and empirically obtained O+/H+ ion transition level values, are all required for the determination of the topside electron density scale height. The topside electron density is considered as a sum of the constituent oxygen and hydrogen ion densities with unknown vertical scale heights. The latter are calculated by solving a system of transcendental equations that arise from the incorporation of a suitable ionospheric profiler (Chapman, Epstein, or Exponential) into formulae describing ionospheric conditions (plasma quasi-neutrality, ion transition level). Once the topside scale heights are determined, the construction of the vertical electron density distribution in the entire altitude range is a straightforward process. As a by-product of the described procedure, the value of the ionospheric slab thickness can be easily computed. To be able to provide forecast, additional information about the current solar and geomagnetic activity is needed. For the purpose, observations available in real time -- at the Royal Institute of Meteorology (RMI), the Royal Observatory of Belgium (ROB), and the US National Oceanic and Atmospheric Administration (NOAA) -- are used. Recently, a new hybrid model for estimating and predicting the local magnetic index K has been developed. This hybrid model has the advantage of using both, ground-based (geomagnetic field components) and space-based (solar wind parameters) measurements, which results in more reliable estimates of the level of geomagnetic activity - current and future. The described reconstruction procedure has been tested on actual measurements at the RMI Dourbes Geophysics Centre (coordinates: 50.1N, 4.6E) where a GPS receiver is collocated with a digital ionosonde (code: DB049, type: Lowell DGS 256). Currently, the nominal time resolution between two consecutive reconstructions is set to 15 minutes with a forecast horizon for each reconstruction of up to 60 minutes. Several applications are envisaged. For example, the ionospheric propagation delays can be estimated and corrected much easier if the electron density profile is available at a nearby location on a real-time basis. Also, both the input data and the reconstruction results can be used for validation purposes in ionospheric models, maps, and services. Recent studies suggest that such ionospheric monitoring systems can help research/services related to aircraft navigation, e.g. for development of the ‘ionospheric threat' methodology.

Commercial high-level-waste management: Options and economics. A comparative analysis of the ceramic and glass waste forms

NASA Astrophysics Data System (ADS)

McKisson, R. L.; Grantham, L. F.; Guon, J.; Recht, H. L.

1983-02-01

Results of an estimate of the waste management costs of the commercial high level waste from a 3000 metric ton per year reprocessing plant show that the judicious use of the ceramic waste form can save about $2 billion during a 20 year operating campaign relative to the use of the glass waste form. This assumes PWR fuel is processed and the waste is encapsulated in 0.305-m-diam canisters with ultimate emplacement in a BWIP-type horizontal-borehole repository. Waste loading and waste form density are the driving factors in that the low waste loading (25%) and relatively low density (3.1 g cu cm) characteristic of the glass form require several times as many canisters to handle a given waste throughput than is needed for the ceramic waste form whose waste loading capability exceeds 60% and whose waste density is nominally 5.2 cu cm.

46 CFR 111.15-25 - Overload and reverse current protection.

Code of Federal Regulations, 2010 CFR

2010-10-01

... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation... battery conductor, except conductors of engine cranking batteries and batteries with a nominal potential of 6 volts or less. For large storage battery installations, the overcurrent protective devices must...

78 FR 67321 - Special Conditions: Bombardier Aerospace Inc., Models BD-500-1A10 and BD-500-1A11 Series...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-12

..., blended double- bubble design, sized for nominal 5-abreast seating. Each airplane's powerplant consists of... part 25, which are level landing attitudes. For airplanes with traditional braking systems, the current...

75 FR 38835 - Solicitation of Nominations for the United States Department of Labor's Iqbal Masih Award for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-06

... of Labor is the date/time stamp of the ILAB/OCFT on the application wrapper or other documentary... currently valid Office of Management and Budget (OMB) control number. This collection of information is...

78 FR 64482 - Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-29

... for the administration of and a record of academic performance of current, former, and nominated... performance of the functions of the agency, including whether the information shall have practical utility; (b... collection instruments, please write to the Center Director, Student Information System, Performance and...

46 CFR 111.15-25 - Overload and reverse current protection.

Code of Federal Regulations, 2013 CFR

2013-10-01

... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation... battery conductor, except conductors of engine cranking batteries and batteries with a nominal potential of 6 volts or less. For large storage battery installations, the overcurrent protective devices must...

46 CFR 111.15-25 - Overload and reverse current protection.

Code of Federal Regulations, 2014 CFR

2014-10-01

... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation... battery conductor, except conductors of engine cranking batteries and batteries with a nominal potential of 6 volts or less. For large storage battery installations, the overcurrent protective devices must...

46 CFR 111.15-25 - Overload and reverse current protection.

Code of Federal Regulations, 2011 CFR

2011-10-01

... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation... battery conductor, except conductors of engine cranking batteries and batteries with a nominal potential of 6 volts or less. For large storage battery installations, the overcurrent protective devices must...

46 CFR 111.15-25 - Overload and reverse current protection.

Code of Federal Regulations, 2012 CFR

2012-10-01

... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation... battery conductor, except conductors of engine cranking batteries and batteries with a nominal potential of 6 volts or less. For large storage battery installations, the overcurrent protective devices must...

47 CFR 15.31 - Measurement standards.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the installation site, such as perimeter protection systems, carrier current systems, and systems... variation of the input power or the radiated signal level of the fundamental frequency component of the... nominal rated supply voltage. For battery operated equipment, the equipment tests shall be performed using...

Superconducting fault current limiter for railway transport

NASA Astrophysics Data System (ADS)

Fisher, L. M.; Alferov, D. F.; Akhmetgareev, M. R.; Budovskii, A. I.; Evsin, D. V.; Voloshin, I. F.; Kalinov, A. V.

2015-12-01

A resistive switching superconducting fault current limiter (SFCL) for DC networks with voltage of 3.5 kV and nominal current of 2 kA is developed. The SFCL consists of two series-connected units: block of superconducting modules and high-speed vacuum breaker with total disconnection time not more than 8 ms. The results of laboratory tests of superconducting SFCL modules in current limiting mode are presented. The recovery time of superconductivity is experimentally determined. The possibility of application of SFCL on traction substations of Russian Railways is considered.

Earth Observing-1 Advanced Land Imager: Dark Current and Noise Characterization and Anomalous Detectors

NASA Technical Reports Server (NTRS)

Mendenhall, J. A.

2001-01-01

The dark current and noise characteristics of the Earth Observing-1 Advanced Land Imager measured during ground calibration at MIT Lincoln Laboratory are presented. Data were collected for the nominal focal plane operating temperature of 220 K as well as supplemental operating temperatures (215 and 225 K). Dark current baseline values are provided, and noise characterization includes the evaluation of white, coherent, low frequency, and high frequency components. Finally, anomalous detectors, characterized by unusual dark current, noise, gain, or cross-talk properties are investigated.

Description and Flight Performance Results of the WASP Sounding Rocket

NASA Technical Reports Server (NTRS)

De Pauw, J. F.; Steffens, L. E.; Yuska, J. A.

1968-01-01

A general description of the design and construction of the WASP sounding rocket and of the performance of its first flight are presented. The purpose of the flight test was to place the 862-pound (391-kg) spacecraft above 250 000 feet (76.25 km) on free-fall trajectory for at least 6 minutes in order to study the effect of "weightlessness" on a slosh dynamics experiment. The WASP sounding rocket fulfilled its intended mission requirements. The sounding rocket approximately followed a nominal trajectory. The payload was in free fall above 250 000 feet (76.25 km) for 6.5 minutes and reached an apogee altitude of 134 nautical miles (248 km). Flight data including velocity, altitude, acceleration, roll rate, and angle of attack are discussed and compared to nominal performance calculations. The effect of residual burning of the second stage motor is analyzed. The flight vibration environment is presented and analyzed, including root mean square (RMS) and power spectral density analysis.

Two nominated for Science Board

NASA Astrophysics Data System (ADS)

President Ronald Reagan plans to nominate Thomas B. Day and James J. Duderstadt to the National Science Board (NSB), according to an announcement by the National Science Foundation (NSF). Day, a theoretical and experimental high-energy physicist, is president of San Diego State University, San Diego, Calif. Duderstadt is a nuclear engineer and is dean of the College of Engineering of the University of Michigan, Ann Arbor.The 24-member NSB is the policy-making body of the NSF. Current members of the NSB include Peter T. Flawn, a geologist who is president of the University of Texas at Austin, and William A. Nierenberg, director of the Scripps Institution of Oceanography at the University of California, San Diego.

Optical observations on the CRIT-II Critical Ionization Velocity Experiment

NASA Technical Reports Server (NTRS)

Stenbaek-Nielsen, H. C.; Wescott, E. M.; Haerendel, G.; Valenzuela, A.

1990-01-01

A rocket borne Critical Ionization Velocity (CIV0 experiment was carried out from Wallops Island at dusk on May 4, 1989. Two barium shaped charges were released below the solar terminator (to prevent photoionization) at altitudes near 400 km. The ambient ionospheric electron density was 50,000/cu cm. The neutral barium jet was directed upward and at an angle of nominally 45 degrees to B which gives approximately 3 x 10 to the 23rd neutrals with super critical velocity. Ions created by a CIV process in the region of the neutral jet would travel up along B into sunlight where they can be detected optically. Well defined ion clouds (max. brightness 750 R) were observed in both releases. An ionization rate of 0.8 percent/sec (125 sec ionization time constant) can account for the observed ion cloud near the release field line, but the ionization rate falls off with increasing distance from the release. It is concluded that a CIV process was present in the neutral jet out to about 50 km from the release, which is significantly further than allowed by current theories.

ZnFe2O4-C/LiFePO4-CNT: A Novel High-Power Lithium-Ion Battery with Excellent Cycling Performance.

PubMed

Varzi, Alberto; Bresser, Dominic; von Zamory, Jan; Müller, Franziska; Passerini, Stefano

2014-07-15

An innovative and environmentally friendly battery chemistry is proposed for high power applications. A carbon-coated ZnFe 2 O 4 nanoparticle-based anode and a LiFePO 4 -multiwalled carbon nanotube-based cathode, both aqueous processed with Na-carboxymethyl cellulose, are combined, for the first time, in a Li-ion full cell with exceptional electrochemical performance. Such novel battery shows remarkable rate capabilities, delivering 50% of its nominal capacity at currents corresponding to ≈20C (with respect to the limiting cathode). Furthermore, the pre-lithiation of the negative electrode offers the possibility of tuning the cell potential and, therefore, achieving remarkable gravimetric energy and power density values of 202 Wh kg -1 and 3.72 W kg -1 , respectively, in addition to grant a lithium reservoir. The high reversibility of the system enables sustaining more than 10 000 cycles at elevated C-rates (≈10C with respect to the LiFePO 4 cathode), while retaining up to 85% of its initial capacity.

ZnFe2O4-C/LiFePO4-CNT: A Novel High-Power Lithium-Ion Battery with Excellent Cycling Performance

PubMed Central

Varzi, Alberto; Bresser, Dominic; von Zamory, Jan; Müller, Franziska; Passerini, Stefano

2014-01-01

An innovative and environmentally friendly battery chemistry is proposed for high power applications. A carbon-coated ZnFe2O4 nanoparticle-based anode and a LiFePO4-multiwalled carbon nanotube-based cathode, both aqueous processed with Na-carboxymethyl cellulose, are combined, for the first time, in a Li-ion full cell with exceptional electrochemical performance. Such novel battery shows remarkable rate capabilities, delivering 50% of its nominal capacity at currents corresponding to ≈20C (with respect to the limiting cathode). Furthermore, the pre-lithiation of the negative electrode offers the possibility of tuning the cell potential and, therefore, achieving remarkable gravimetric energy and power density values of 202 Wh kg−1 and 3.72 W kg−1, respectively, in addition to grant a lithium reservoir. The high reversibility of the system enables sustaining more than 10 000 cycles at elevated C-rates (≈10C with respect to the LiFePO4 cathode), while retaining up to 85% of its initial capacity. PMID:26190956

Developmental status and system studies of the monolithic solid oxide fuel cell

NASA Astrophysics Data System (ADS)

Myles, K. M.

The monolithic solid oxide fuel cell (MSOFC) was invented at the Argonne National Laboratory in 1983 and is currently being developed by a team consisting of Argonne National Laboratory and Allied-Signal Aerospace/AiResearch. The MSOFC is an oxide ceramic structure in which appropriate electronic and ionic conductors are fabricated in a honeycomb shape similar to a block of corrugated paperboard. The electrolyte, which conducts oxygens ions from the air side to the fuel side, is yttria-stabilized zirconia (YSZ). All the other materials, that is, the nickel-YSZ anode, the strontium-doped lanthanum manganite cathode, and the doped lanthanum chromite interconnect (bipolar plate), are electronic conductors. These electronic and ionic conductors are arranged to provide short conduction paths to minimize resistive losses. The power density achievable with the MSOFC is expected to be about 8 kW/kg or 4 kW/l at fuel efficiencies over 50 percent, because of small cell size and low resistive losses in the materials. These performances have been approached in laboratory test fuel cell stacks of nominal 125-W capacities.

Controlled Ascent From the Surface of an Asteroid

NASA Technical Reports Server (NTRS)

Shen, Haijun; Roithmayr, Carlos M.; Cornelius, David M.

2014-01-01

The National Aeronautics and Space Administration (NASA) is currently investigating a conceptual robotic mission to collect a small boulder up to 4 m in diameter resting on the surface of a large Near Earth Asteroid (NEA). Because most NEAs are not well characterized, a great range of uncertainties in boulder mass properties and NEA surface characteristics must be considered in the design of this mission. These uncertainties are especially significant when the spacecraft ascends with the boulder in tow. The most important requirement during ascent is to keep the spacecraft in an upright posture to maintain healthy ground clearances for the two large solar arrays. This paper focuses on the initial stage (the first 50 m) of ascent from the surface. Specifically, it presents a sensitivity study of the solar array ground clearance, control authority, and accelerations at the array tips in the presence of a variety of uncertainties including various boulder sizes, densities, shapes and orientations, locations of the true center of mass, and push-off force distributions. Results are presented, and appropriate operations are recommended in the event some of the off-nominal cases occur.

Design and test status for life support applications of SPE oxygen generation systems. [Solid Polymer Electrolyte

NASA Technical Reports Server (NTRS)

Titterington, W. A.; Erickson, A. C.

1975-01-01

An advanced six-man rated oxygen generation system has been fabricated and tested as part of a NASA/JSC technology development program for a long lived, manned spacecraft life support system. Details of the design and tests results are presented. The system is based on the Solid Polymer Electrolyte (SPE) water electrolysis technology and its nominal operating conditions are 2760 kN/sq m (400 psia) and 355 K (180 F) with an electrolysis module current density capability up to 350 mA/sq cm (326 ASF). The system is centered on a 13-cell SPE water electrolysis module having a single cell active area of 214 sq cm (33 sq in) and it incorporates instrumentation and controls for single pushbutton automatic startup/shutdown, component fault detection and isolation, and self-contained sensors and controls for automatic safe emergency shutdown. The system has been tested in both the orbital cyclic and continuous mode of operation. Various parametric tests have been completed to define the system capability for potential application in spacecraft environmental systems.

NASCAP simulation of PIX 2 experiments

NASA Technical Reports Server (NTRS)

Roche, J. C.; Mandell, M. J.

1985-01-01

The latest version of the NASCAP/LEO digital computer code used to simulate the PIX 2 experiment is discussed. NASCAP is a finite-element code and previous versions were restricted to a single fixed mesh size. As a consequence the resolution was dictated by the largest physical dimension to be modeled. The latest version of NASCAP/LEO can subdivide selected regions. This permitted the modeling of the overall Delta launch vehicle in the primary computational grid at a coarse resolution, with subdivided regions at finer resolution being used to pick up the details of the experiment module configuration. Langmuir probe data from the flight were used to estimate the space plasma density and temperature and the Delta ground potential relative to the space plasma. This information is needed for input to NASCAP. Because of the uncertainty or variability in the values of these parameters, it was necessary to explore a range around the nominal value in order to determine the variation in current collection. The flight data from PIX 2 were also compared with the results of the NASCAP simulation.

Uncertainty in Steady-State Diagnostics of a Current-Pressure Transducer: How Confident are We in Diagnosing Faults

DTIC Science & Technology

2014-10-02

and off-nominal behav- ior of the I/ P transducer; however, sensor measurements are not fast enough to capture brief transient states that are in...nasa.gov 3 NASA Ames Research Center, Moffett Field, CA 94035, USA kai.goebel@nasa.gov ABSTRACT Current-Pressure (I/ P ) transducers are effective...transducers (I/ P transducer or IPT) are ef- fective pressure regulators that vary the output pressure de- pending on the supplied electrical current

Effects of surface roughening on the mass transport and mechanical properties of ionic polymer-metal composite

NASA Astrophysics Data System (ADS)

Chang, Longfei; Asaka, Kinji; Zhu, Zicai; Wang, Yanjie; Chen, Hualing; Li, Dichen

2014-06-01

Ionic Polymer-Metal Composite (IPMC) has been well-documented of being a promising functional material in extensive applications. In its most popular and traditional manufacturing technique, roughening is a key process to ensure a satisfying performance. In this paper, based on a lately established multi-physical model, the effect of roughening process on the inner mass transportation and the electro-active output of IPMC were investigated. In the model, the electro-chemical field was monitored by Poisson equation and a properly simplified Nernst-Planck equation set, while the mechanical field was evaluated on the basis of volume strain effect. Furthermore, with Ramo-Shockley theorem, the out-circuit current and accumulated charge on the electrode were bridged with the inner cation distribution. Besides, nominal current and charge density as well as the curvature of the deformation were evaluated to characterize the performance of IPMC. The simulation was implemented by Finite Element Method with Comsol Multi-physics, based on two groups of geometrical models, those with various rough interface and those with different thickness. The results of how the roughening impact influences on the performance of IPMC were discussed progressively in three aspects, steady-state distribution of local potential and mass concentration, current response and charge accumulation, as well as the curvature of deformation. Detailed explanations for the performance improvement resulted from surface roughening were provided from the micro-distribution point of view, which can be further explored for the process optimization of IPMC.

Receptivity of a Cryogenic Coaxial Liquid Jet to Acoustic Disturbances

DTIC Science & Technology

2014-01-01

PAGES 19a. NAME OF RESPONSIBLE PERSON D. Talley a. REPORT Unclassified b. ABSTRACT Unclassified c . THIS PAGE Unclassified SAR 13 19b... c pu c    (1) where u’ is the magnitude of the velocity fluctuation in the velocity antinode region, p’ is the magnitude of the pressure...fluctuation in the pressure antinode region,  c is the density of the ambient gas in the chamber, which is nominal room temperature nitrogen, and c

Creation of Scalable, Cartridge-Based Microreactor Reformers

DTIC Science & Technology

2010-10-31

empty. In all cases, dense fired cordierite honeycomb- monoliths with a cell density of 72 cells per square inch (CPS1) were supplied from Rauschert...34 nominal pipe thread (NPT) fittings for fluidic connections to the experimental apparatus. All prototype features and fluidic connections were 1/16", with...of 3000 rpm for 1 min. The photoresist is then soft baked at 90°C for 1 minute on a hot plate. The resist is exposed to Mask Al/Cl by proximity

Experimental and Analytical Study of the Hydroacoustics of Propellers in Rigid Ducts

DTIC Science & Technology

2006-07-01

5.3 at this loading condition indicate that the axial distribution of velocity is nearly uniform, and equal to the nominal value of 0.42 as set by the...moderate loading case produced the lowest level of radiated sound. The decrease in the mean axial velocity from the 0=0.42 condition corresponds to a...RtQ) X Axial coordinate p Fluid density W Azimuthal coordinate I\\ Acoustic wavelength c/f 50 Flow coefficient ( ui-p_ Blade loading coefficient ( \\ 1

Magnetopause reconnection under various space weather conditions

NASA Astrophysics Data System (ADS)

Chen, L.; Argall, M. R.; Shuster, J. R.; Li, G.; Karimabadi, H.; Daughton, W. S.; Germaschewski, K.; Torbert, R. B.; Bhattacharjee, A.

2013-12-01

In order to develop predictive capabilities for the Sun-Earth connection, the question of how various reconnection upstream conditions influence particle energization and the stability of the reconnection current layer needs to be answered. Using magnetopause reconnection events observed by the Cluster spacecraft, we address this question by comparing the observed plasma and field features in the vicinity of the magnetopause current layer for a wide range of geomagnetic conditions including nominal times and the most severe magnetic storms. Outstanding features include: 1. Plasmoid-like structures, when observed, tend to appear in series and more frequently on the magnetosheath side of the magnetopause current layer. These plasmoids contain accelerated electrons and ions up to ~100 keV, and can prevail in guide fields ranging from nearly zero to a strength approximately equal to the reconnecting field. Associated with each of these plasmoids are a bipolar DC component and intense fluctuations in the electric fields. 2. The fastest ion outflow jets occur in the magnetospheric side of the magnetopause. 3. The plasma density transition is in general removed from the magnetopause current layer to the magnetospheric side, in contrast to the predictions of a PIC simulation and THEMIS observations [1]. Feature 1 suggests that the current layer is unstable to plasmoid formation, and that the plasmoids are effective energization sites for plasmas. The above features are not sensitive functions of the degrees of upstream asymmetries. The observation results will be compared with PIC, global hybrid as well as global Hall MHD simulations to achieve fundamental understanding of asymmetric reconnection, separating two-fluid, ion kinetic and electron kinetic effects. [1] Mozer and Pritchett, JGR, 2008

A Computational Analysis of Complex Noun Phrases in Navy Messages

DTIC Science & Technology

1984-07-01

Hirschman. Automated Determination of Suhlanguage Syntactic Usage. Proc. COLING 84) (current volume). [Hirschman 1082 ] Hirsehman, L. Constraints on...Restricted Semantic Domains. de Grnyter New York, 1082 . [Levi 1078] Levi, J.N. The Syntaz and Semantics of Com- plez Nominals, Academic Press, New York

75 FR 32769 - Science Advisory Board Staff Office; Request for Nominations of Experts to Provide Scientific and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-09

... recognized experts with demonstrated research or operational experience assessing the environmental impacts... following disciplines: Chemistry; fate, transport and exposure assessment; toxicology; public health... biographical sketch of the nominee indicating current position, educational background, research activities...

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

Elgowainy, Amgad; Han, Jeongwoo; Ward, Jacob

This study provides a comprehensive lifecycle analysis (LCA), or cradle-to-grave (C2G) analysis, of the cost and greenhouse gas (GHG) emissions of a variety of vehicle-fuel pathways, as well as the levelized cost of driving (LCD) and cost of avoided GHG emissions. This study also estimates the technology readiness levels (TRLs) of key fuel and vehicle technologies along the pathways. The C2G analysis spans a full portfolio of midsize light-duty vehicles (LDVs), including conventional internal combustion engine vehicles (ICEVs), flexible fuel vehicles (FFVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), and fuel cell electric vehiclesmore » (FCEVs). In evaluating the vehicle-fuel combinations, this study considers both low-volume and high-volume “CURRENT TECHNOLOGY” cases (nominally 2015) and a high-volume “FUTURE TECHNOLOGY” lower-carbon case (nominally 2025–2030). For the CURRENT TECHNOLOGY case, low-volume vehicle and fuel production pathways are examined to determine costs in the near term.« less

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

Elgowainy, Amgad; Han, Jeongwoo; Ward, Jacob

This study provides a comprehensive life-cycle analysis (LCA), or cradle-to-grave (C2G) analysis, of the cost and greenhouse gas (GHG) emissions of a variety of vehicle-fuel pathways, as well as the levelized cost of driving (LCD) and cost of avoided GHG emissions. This study also estimates the technology readiness levels (TRLs) of key fuel and vehicle technologies along the pathways. The C2G analysis spans a full portfolio of midsize light-duty vehicles (LDVs), including conventional internal combustion engine vehicles (ICEVs), flexible fuel vehicles (FFVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), and fuel cell electric vehiclesmore » (FCEVs). In evaluating the vehicle-fuel combinations, this study considers both low-volume and high-volume “CURRENT TECHNOLOGY” cases (nominally 2015) and a high-volume “FUTURE TECHNOLOGY” lower-carbon case (nominally 2025–2030). For the CURRENT TECHNOLOGY case, low-volume vehicle and fuel production pathways are examined to determine costs in the near term.« less

Transcranial direct current stimulation combined with integrative speech therapy in a child with cerebral palsy: A case report.

PubMed

Carvalho Lima, Vania L C; Collange Grecco, Luanda A; Marques, Valéria C; Fregni, Felipe; Brandão de Ávila, Clara R

2016-04-01

The aim of this study was to describe the results of the first case combining integrative speech therapy with anodal transcranial direct current stimulation (tDCS) over Broca's area in a child with cerebral palsy. The ABFW phonology test was used to analyze speech based on the Percentage of Correct Consonants (PCC) and Percentage of Correct Consonants - Revised (PCC-R). After treatment, increases were found in both PCC (Imitation: 53.63%-78.10%; Nomination: 53.19%-70.21%) and PPC-R (Imitation: 64.54%-83.63%; Nomination: 61.70%-77.65%). Moreover, reductions occurred in distortions, substitutions and improvement was found in oral performance, especially tongue mobility (AMIOFE-mobility before = 4 after = 7). The child demonstrated a clinically important improvement in speech fluency as shown in results of imitation number of correct consonants and phonemes acquire. Based on these promising findings, continuing research in this field should be conducted with controlled clinical trials. Copyright © 2015 Elsevier Ltd. All rights reserved.

Operating in "Strange New Worlds" and Measuring Success - Test and Evaluation in Complex Environments

NASA Technical Reports Server (NTRS)

Qualls, Garry; Cross, Charles; Mahlin, Matthew; Montague, Gilbert; Motter, Mark; Neilan, James; Rothhaar, Paul; Tran, Loc; Trujillo, Anna; Allen, B. Danette

2015-01-01

Software tools are being developed by the Autonomy Incubator at NASA's Langley Research Center that will provide an integrated and scalable capability to support research and non-research flight operations across several flight domains, including urban and mixed indoor-outdoor operations. These tools incorporate a full range of data products to support mission planning, approval, flight operations, and post-flight review. The system can support a number of different operational scenarios that can incorporate live and archived data streams for UAS operators, airspace regulators, and other important stakeholders. Example use cases are described that illustrate how the tools will benefit a variety of users in nominal and off-nominal operational scenarios. An overview is presented for the current state of the toolset, including a summary of current demonstrations that have been completed. Details of the final, fully operational capability are also presented, including the interfaces that will be supported to ensure compliance with existing and future airspace operations environments.

Evaluation of interference fit and bone damage of an uncemented femoral knee implant.

PubMed

Berahmani, Sanaz; Hendriks, Maartje; de Jong, Joost J A; van den Bergh, Joop P W; Maal, Thomas; Janssen, Dennis; Verdonschot, Nico

2018-01-01

During implantation of an uncemented femoral knee implant, press-fit interference fit provides the primary stability. It is assumed that during implantation a combination of elastic and plastic deformation and abrasion of the bone will occur, but little is known about what happens at the bone-implant interface and how much press-fit interference fit is eventually achieved. Five cadaveric femora were prepared and implantation was performed by an experienced surgeon. Micro-CT- and conventional CT-scans were obtained pre- and post-implantation for geometrical measurements and to measure bone mineral density. Additionally, the position of the implant with respect to the bone was determined by optical scanning of the reconstructions. By measuring the differences in surface geometry, assessments were made of the cutting error, the actual interference fit, the amount of bone damage, and the effective interference fit. Our analysis showed an average cutting error of 0.67mm (SD 0.17mm), which pointed mostly towards bone under-resections. We found an average actual AP interference fit of 1.48mm (SD 0.27mm), which was close to the nominal value of 1.5mm. We observed combinations of bone damage and elastic deformation in all bone specimens, which showed a trend to be related with bone density. Higher bone density tended to lead to lower bone damage and higher elastic deformation. The results of the current study indicate different factors that interact while implanting an uncemented femoral knee component. This knowledge can be used to fine-tune design criteria of femoral components to achieve adequate primary stability for all patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Low-Speed Flight Dynamic Tests and Analysis of the Orion Crew Module Drogue Parachute System

NASA Technical Reports Server (NTRS)

Hahne, David E.; Fremaux, C. Michael

2008-01-01

A test of a dynamically scaled model of the NASA Orion Crew Module (CM) with drogue parachutes was conducted in the NASA-Langley 20-Foot Vertical Spin Tunnel. The primary test objective was to assess the ability of the Orion Crew Module drogue parachute system to adequately stabilize the CM and reduce angular rates at low subsonic Mach numbers. Two attachment locations were tested: the current design nominal and an alternate. Experimental results indicated that the alternate attachment location showed a somewhat greater tendency to attenuate initial roll rate and reduce roll rate oscillations than the nominal location. Comparison of the experimental data to a Program To Optimize Simulated Trajectories (POST II) simulation of the experiment yielded results for the nominal attachment point that indicate differences between the low-speed pitch and yaw damping derivatives in the aerodynamic database and the physical model. Comparisons for the alternate attachment location indicate that riser twist plays a significant role in determining roll rate attenuation characteristics. Reevaluating the impact of the alternate attachment points using a simulation modified to account for these results showed significantly reduced roll rate attenuation tendencies when compared to the original simulation. Based on this modified simulation the alternate attachment point does not appear to offer a significant increase in allowable roll rate over the nominal configuration.

The Small Aircraft Transportation System (SATS), Higher Volume Operations (HVO) Off-Nominal Operations

NASA Technical Reports Server (NTRS)

Baxley, B.; Williams, D.; Consiglio, M.; Conway, S.; Adams, C.; Abbott, T.

2005-01-01

The ability to conduct concurrent, multiple aircraft operations in poor weather, at virtually any airport, offers an important opportunity for a significant increase in the rate of flight operations, a major improvement in passenger convenience, and the potential to foster growth of charter operations at small airports. The Small Aircraft Transportation System, (SATS) Higher Volume Operations (HVO) concept is designed to increase traffic flow at any of the 3400 nonradar, non-towered airports in the United States where operations are currently restricted to one-in/one-out procedural separation during Instrument Meteorological Conditions (IMC). The concept's key feature is pilots maintain their own separation from other aircraft using procedures, aircraft flight data sent via air-to-air datalink, cockpit displays, and on-board software. This is done within the Self-Controlled Area (SCA), an area of flight operations established during poor visibility or low ceilings around an airport without Air Traffic Control (ATC) services. The research described in this paper expands the HVO concept to include most off-nominal situations that could be expected to occur in a future SATS environment. The situations were categorized into routine off-nominal operations, procedural deviations, equipment malfunctions, and aircraft emergencies. The combination of normal and off-nominal HVO procedures provides evidence for an operational concept that is safe, requires little ground infrastructure, and enables concurrent flight operations in poor weather.

Solvent Hold Tank Sample Results for MCU-15-661-662-663: April 2015 Monthly Sample

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

Fondeur, F.; Taylor-Pashow, K.

2015-07-08

The Savannah River National Lab (SRNL) received one set of Solvent Hold Tank (SHT) samples (MCU-15-661, MCU-15-662, and MCU-15-663 pulled on April 2, 2015) for analysis. The samples were combined and analyzed for composition. Analysis of the composite sample MCU-15-661-662-663 indicated a low concentration (~ 63% of nominal) of the suppressor (TiDG) and a slightly below the nominal concentration (~ 10% below nominal) of the extractant (MaxCalix). The modifier (CS-7SB) level was also 10% below its nominal value while the Isopar™ L level was slightly above its nominal value. This analysis confirms the addition of Isopar™L to the solvent onmore » March 6, 2015. Despite that the values are below target component levels, the current levels of TiDG, CS-7SB and MaxCalix are sufficient for continuing operation without adding a trim at this time until the next monthly sample. No impurities above the 1000 ppm level were found in this solvent. However, the sample was found to contain approximately 18.4 ug/g solvent mercury. The gamma level increased to 8 E5 dpm/mL solvent and it represents an order of magnitude increase relative to previous solvent samples. The increase means less cesium is being stripped from the solvent. Further analysis is needed to determine if the recent spike in the gamma measurement is due to external factors such as algae or other material that may impede stripping. The laboratory will continue to monitor the quality of the solvent in particular for any new impurity or degradation of the solvent components.« less

Design, performance, and calculated error of a Faraday cup for absolute beam current measurements of 600-MeV protons

NASA Technical Reports Server (NTRS)

Beck, S. M.

1975-01-01

A mobile self-contained Faraday cup system for beam current measurments of nominal 600 MeV protons was designed, constructed, and used at the NASA Space Radiation Effects Laboratory. The cup is of reentrant design with a length of 106.7 cm and an outside diameter of 20.32 cm. The inner diameter is 15.24 cm and the base thickness is 30.48 cm. The primary absorber is commercially available lead hermetically sealed in a 0.32-cm-thick copper jacket. Several possible systematic errors in using the cup are evaluated. The largest source of error arises from high-energy electrons which are ejected from the entrance window and enter the cup. A total systematic error of -0.83 percent is calculated to be the decrease from the true current value. From data obtained in calibrating helium-filled ion chambers with the Faraday cup, the mean energy required to produce one ion pair in helium is found to be 30.76 + or - 0.95 eV for nominal 600 MeV protons. This value agrees well, within experimental error, with reported values of 29.9 eV and 30.2 eV.

Measurement of the single π0 production rate in neutral current neutrino interactions on water

NASA Astrophysics Data System (ADS)

Abe, K.; Amey, J.; Andreopoulos, C.; Antonova, M.; Aoki, S.; Ariga, A.; Ashida, Y.; Assylbekov, S.; Autiero, D.; Ban, S.; Barbi, M.; Barker, G. J.; Barr, G.; Barry, C.; Bartet-Friburg, P.; Batkiewicz, M.; Berardi, V.; Berkman, S.; Bhadra, S.; Bienstock, S.; Blondel, A.; Bolognesi, S.; Bordoni, S.; Boyd, S. B.; Brailsford, D.; Bravar, A.; Bronner, C.; Buizza Avanzini, M.; Calland, R. G.; Campbell, T.; Cao, S.; Cartwright, S. L.; Castillo, R.; Catanesi, M. G.; Cervera, A.; Chappell, A.; Checchia, C.; Cherdack, D.; Chikuma, N.; Christodoulou, G.; Clifton, A.; Coleman, J.; Collazuol, G.; Coplowe, D.; Cremonesi, L.; Cudd, A.; Dabrowska, A.; De Rosa, G.; Dealtry, T.; Denner, P. F.; Dennis, S. R.; Densham, C.; Dewhurst, D.; Di Lodovico, F.; Di Luise, S.; Dolan, S.; Drapier, O.; Duffy, K. E.; Dumarchez, J.; Dunkman, M.; Dunne, P.; Dziewiecki, M.; Emery-Schrenk, S.; Ereditato, A.; Feusels, T.; Finch, A. J.; Fiorentini, G. A.; Friend, M.; Fujii, Y.; Fukuda, D.; Fukuda, Y.; Furmanski, A. P.; Galymov, V.; Garcia, A.; Giffin, S. G.; Giganti, C.; Gilje, K.; Gizzarelli, F.; Golan, T.; Gonin, M.; Grant, N.; Hadley, D. R.; Haegel, L.; Haigh, J. T.; Hamilton, P.; Hansen, D.; Harada, J.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayashino, T.; Hayato, Y.; Helmer, R. L.; Hierholzer, M.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hiramoto, A.; Hirota, S.; Hogan, M.; Holeczek, J.; Hosomi, F.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ikeda, M.; Imber, J.; Insler, J.; Intonti, R. A.; Irvine, T. J.; Ishida, T.; Ishii, T.; Iwai, E.; Iwamoto, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Jiang, M.; Johnson, S.; Jo, J. H.; Jonsson, P.; Jung, C. K.; Kabirnezhad, M.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Karlen, D.; Karpikov, I.; Katori, T.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kim, H.; Kim, J.; King, S.; Kisiel, J.; Knight, A.; Knox, A.; Kobayashi, T.; Koch, L.; Koga, T.; Koller, P. P.; Konaka, A.; Kondo, K.; Kopylov, A.; Kormos, L. L.; Korzenev, A.; Koshio, Y.; Kowalik, K.; Kropp, W.; Kudenko, Y.; Kurjata, R.; Kutter, T.; Lagoda, J.; Lamont, I.; Lamoureux, M.; Larkin, E.; Lasorak, P.; Laveder, M.; Lawe, M.; Lazos, M.; Licciardi, M.; Lindner, T.; Liptak, Z. J.; Litchfield, R. P.; Li, X.; Longhin, A.; Lopez, J. P.; Lou, T.; Ludovici, L.; Lu, X.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Maret, L.; Marino, A. D.; Marteau, J.; Martin, J. F.; Martins, P.; Martynenko, S.; Maruyama, T.; Matveev, V.; Mavrokoridis, K.; Ma, W. Y.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Mefodiev, A.; Metelko, C.; Mezzetto, M.; Mijakowski, P.; Minamino, A.; Mineev, O.; Mine, S.; Missert, A.; Miura, M.; Moriyama, S.; Morrison, J.; Mueller, Th. A.; Murphy, S.; Myslik, J.; Nakadaira, T.; Nakahata, M.; Nakamura, K. G.; Nakamura, K.; Nakamura, K. D.; Nakanishi, Y.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Nantais, C.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; Novella, P.; Nowak, J.; O'Keeffe, H. M.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Ovsyannikova, T.; Owen, R. A.; Oyama, Y.; Palladino, V.; Palomino, J. L.; Paolone, V.; Patel, N. D.; Paudyal, P.; Pavin, M.; Payne, D.; Perkin, J. D.; Petrov, Y.; Pickard, L.; Pickering, L.; Pinzon Guerra, E. S.; Pistillo, C.; Popov, B.; Posiadala-Zezula, M.; Poutissou, J.-M.; Poutissou, R.; Pritchard, A.; Przewlocki, P.; Quilain, B.; Radermacher, T.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A.; Redij, A.; Reinherz-Aronis, E.; Riccio, C.; Rojas, P.; Rondio, E.; Rossi, B.; Roth, S.; Rubbia, A.; Ruggeri, A. C.; Rychter, A.; Sacco, R.; Sakashita, K.; Sánchez, F.; Sato, F.; Scantamburlo, E.; Scholberg, K.; Schwehr, J.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shah, R.; Shaikhiev, A.; Shaker, F.; Shaw, D.; Shiozawa, M.; Shirahige, T.; Short, S.; Smy, M.; Sobczyk, J. T.; Sobel, H.; Sorel, M.; Southwell, L.; Stamoulis, P.; Steinmann, J.; Stewart, T.; Stowell, P.; Suda, Y.; Suvorov, S.; Suzuki, A.; Suzuki, K.; Suzuki, S. Y.; Suzuki, Y.; Tacik, R.; Tada, M.; Takahashi, S.; Takeda, A.; Takeuchi, Y.; Tamura, R.; Tanaka, H. K.; Tanaka, H. A.; Terhorst, D.; Terri, R.; Thakore, T.; Thompson, L. F.; Tobayama, S.; Toki, W.; Tomura, T.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Vacheret, A.; Vagins, M.; Vallari, Z.; Vasseur, G.; Vilela, C.; Vladisavljevic, T.; Wachala, T.; Wakamatsu, K.; Walter, C. W.; Wark, D.; Warzycha, W.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Wilson, J. R.; Wilson, R. J.; Wret, C.; Yamada, Y.; Yamamoto, K.; Yamamoto, M.; Yanagisawa, C.; Yano, T.; Yen, S.; Yershov, N.; Yokoyama, M.; Yoo, J.; Yoshida, K.; Yuan, T.; Yu, M.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

2018-02-01

The single π0 production rate in neutral current neutrino interactions on water in a neutrino beam with a peak neutrino energy of 0.6 GeV has been measured using the PØD, one of the subdetectors of the T2K near detector. The production rate was measured for data taking periods when the PØD contained water (2.64 ×1020 protons-on-target) and also periods without water (3.49 ×1020 protons-on-target). A measurement of the neutral current single π0 production rate on water is made using appropriate subtraction of the production rate with water in from the rate with water out of the target region. The subtraction analysis yields 106 ±41 ±69 signal events where the uncertainties are statistical (stat.) and systematic (sys.) respectively. This is consistent with the prediction of 157 events from the nominal simulation. The measured to expected ratio is 0.68 ±0.26 (stat ) ±0.44 (sys ) ±0.12 (flux ) . The nominal simulation uses a flux integrated cross section of 7.63 ×10-39 cm2 per nucleon with an average neutrino interaction energy of 1.3 GeV.

Simulation Modeling for Off-Nominal Conditions - Where Are We Today?

NASA Technical Reports Server (NTRS)

Shah, Gautam H.; Foster, John V.; Cunningham, Kevin

2010-01-01

The modeling of aircraft flight characteris4cs in off-nominal or otherwise adverse conditions has become increasingly important for simulation in the loss-of-control arena. Adverse conditions include environmentally-induced upsets such as wind shear or wake vortex encounters; off-nominal flight conditions, such as stall or departure; on-board systems failures; and structural failures or aircraft damage. Spirited discussions in the research community are taking place as to the fidelity and data requirements for adequate representation of vehicle dynamics under such conditions for a host of research areas, including recovery training, flight controls development, trajectory guidance/planning, and envelope limiting. The increasing need for multiple sources of data (empirical, computational, experimental) for modeling across a larger flight envelope leads to challenges in developing methods of appropriately applying or combining such data, particularly in a dynamic flight environment with a physically and/or aerodynamically asymmetric vehicle. Traditional simplifications and symmetry assumptions in current modeling methodology may no longer be valid. Furthermore, once modeled, challenges abound in the validation of flight dynamics characteristics in adverse flight regimes

Who really pays for health insurance? The incidence of employer-provided health insurance with sticky nominal wages.

PubMed

Sommers, Benjamin D

2005-03-01

This paper addresses two seeming paradoxes in the realm of employer-provided health insurance: First, businesses consistently claim that they bear the burden of the insurance they provide for employees, despite theory and empirical evidence indicating that workers bear the full incidence. Second, benefit generosity and the percentage of premiums paid by employers have decreased in recent decades, despite the preferential tax treatment of employer-paid benefits relative to wages-trends unexplained by the standard incidence model. This paper offers a revised incidence model based on nominal wage rigidity, in an attempt to explain these paradoxes. The model predicts that when the nominal wage constraint binds, some of the burden of increasing insurance premiums will fall on firms, particularly small companies with low-wage employees. In response, firms will reduce employment, decrease benefit generosity, and require larger employee premium contributions. Using Current Population Survey data from 2000-2001, I find evidence for this kind of wage rigidity and its associated impact on the employment and premium contributions of low-wage insured workers during a period of rapid premium growth.

30 CFR 250.914 - How do I nominate a CVA?

Code of Federal Regulations, 2010 CFR

2010-07-01

... the individual or the primary staff for the specific project; (3) Size and type of organization or corporation; (4) In-house availability of, or access to, appropriate technology. This should include computer... specific project considering current commitments; (6) Previous experience with MMS requirements and...

30 CFR 585.706 - How do I nominate a CVA for BOEM approval?

Code of Federal Regulations, 2014 CFR

2014-07-01

... technology (including computer programs, hardware, and testing materials and equipment); (5) Ability to perform the CVA functions for the specific project considering current commitments; (6) Previous... facilities; (2) Technical capabilities of the individual or the primary staff for the specific project; (3...

30 CFR 585.706 - How do I nominate a CVA for BOEM approval?

Code of Federal Regulations, 2013 CFR

2013-07-01

... technology (including computer programs, hardware, and testing materials and equipment); (5) Ability to perform the CVA functions for the specific project considering current commitments; (6) Previous... facilities; (2) Technical capabilities of the individual or the primary staff for the specific project; (3...

30 CFR 585.706 - How do I nominate a CVA for BOEM approval?

Code of Federal Regulations, 2012 CFR

2012-07-01

... technology (including computer programs, hardware, and testing materials and equipment); (5) Ability to perform the CVA functions for the specific project considering current commitments; (6) Previous... facilities; (2) Technical capabilities of the individual or the primary staff for the specific project; (3...

Turbine Siting Metrics for Simulated Tidal Flow in a Double-Silled Channel

NASA Astrophysics Data System (ADS)

Thyng, K. M.; Kawase, M.; Riley, J. J.; Northwest National Marine Renewable Energy Center

2010-12-01

An important component of site and resource characterization for marine renewable energy projects is to identify areas with large potential resource but also with easy extractability of the available resource for commercial develop- ment. Metrics that characterize potential resource include mean kinetic power density and speed over a tidal cycle, while important metrics for extractability include measures of the bidirectionality of the tidal flow (asymmetry, directional deviation, and power bias of ebb versus flood tide) as well as percentage of time spent by the device producing power at the particular site. This study examines the character of a tidal flow over an idealized two- dimensional (x-z) double sill in a rectangular channel in terms of these resource characterization metrics. This domain is meant to capture the bulk features of Admiralty Inlet, the main entrance to the Puget Sound, a fjord-like estuary in western Washington State. Admiralty Inlet is an area of interest for build- ing a commercial-scale tidal turbine array, and is currently the location of two potential pilot-scale tidal hydrokinetic projects. Initial results point to the speed up of the incoming flow due to the shallowest sill as an area of strong resource. The presence of the deeper sill affects the character of this strong resource in a way that the metrics can help quantify in terms of extractability of the resource and vertical structure. Together, these metrics will give a clear understanding of the tidal turbine siting characteristics of the domain. In the case of the idealized double sill simulation, the mean speed is increased by a factor of more than 2 over the mean incoming speed at the entrance of the channel due to the shallower, more prominent sill, while the deeper sill sees a multiplication factor of close to 1.5. This is a modest increase in mean speed, but translates to a multiplication factor of over 8 from the nominal far field value near the shallow sill in the mean kinetic power density, with the deeper sill having an increase of a factor of over 4. The mean vertical speed sees an increase of 4 times from the nominal value between the two sills, but little is seen at the shallowest point of the sill at the location of best potential resource.

McNutt to Be Nominated to Lead U.S. Geological Survey

NASA Astrophysics Data System (ADS)

Showstack, Randy

2009-07-01

U.S. President Barack Obama announced on 9 July his intention to nominate Marcia McNutt as director of the U.S. Geological Survey (USGS) and science advisor to the Secretary of the Interior. McNutt, who served as AGU president from 2000 to 2002, currently is president and chief executive officer of the Monterey Bay Aquarium Research Institute, in Moss Landing, Calif. “Scientific information from the U.S. Geological Survey is crucial to solving the most important problems facing society—finding sufficient supplies of fresh water and clean energy and providing accurate information that allows citizens to prepare intelligently for climate change. I look forward to leading such a respected institution at this critical time,” McNutt said.

International Space Station Nickel-Hydrogen Battery Startup and Initial Performance

NASA Technical Reports Server (NTRS)

Dalton, Penni; Cohen, Fred; Hajela, Gyan

2002-01-01

The Battery Orbital Replacement Unit (ORU) was designed to meet the following requirements: a 6.5-year design life, 38,000 charge/discharge Low Earth Orbit cycles, 81-Amp-hr nameplate capacity, 4 kWh nominal storage capacity, contingency orbit capability, an operating temperature of 5 +/- 5 C standard orbit and 5+5/-10 C contingency orbit, a non-operating temperature of -25 to +30 C, a five-year Mean Time between failure, an on-orbit replacement using ISS robotic interface, and one launch to orbit and one return to ground. The ISS electrical power system is successfully maintaining power for all on-board loads. ISS Eclipse power is currently supplied by six Ni-H2 batteries (12 ORUs), which are operating nominally.

Static charge-density-wave order in the superconducting state of La 2 - x Ba x CuO 4

DOE PAGES

Thampy, V.; Chen, X. M.; Cao, Y.; ...

2017-06-15

Charge-density-wave (CDW) correlations feature prominently in the phase diagram of the cuprates, motivating competing theories of whether fluctuating CDW correlations aid superconductivity or whether static CDW order coexists with superconductivity in inhomogeneous or spatially modulated states. Here we report Cu L-edge resonant x-ray photon correlation spectroscopy measurements of CDW correlations in superconducting La 2–xBa xCuO 4, x = 0.11. Static CDW order is shown to exist in the superconducting state at low temperatures and to persist up to at least 85% of the CDW transition temperature. As a result, we discuss the implications of our observations for how nominally competingmore » order parameters can coexist in the cuprates.« less

Understanding Deaf Bilingual Education from the inside: A SWOT Analysis

ERIC Educational Resources Information Center

Munoz-Baell, Irma M.; Alvarez-Dardet, Carlos; Ruiz-Cantero, M.; Ferreiro-Lago, Emilio; Aroca-Fernandez, Eva

2011-01-01

This article reports on a Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis using a nominal group process undertaken to identify and tackle significant factors, both internal and external, affecting those current Deaf bilingual practices in Spain which promote or prevent the processes through which more inclusive (barrier-free)…

49 CFR 232.5 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... which the motion of a railroad car or locomotive is retarded or arrested. Air Flow Indicator, AFM means... moving train is used to generate electric current at the locomotive traction motors, which is then... that is capable of producing its nominally designed retarding force on the train. A car's air brake is...

49 CFR 232.5 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... which the motion of a railroad car or locomotive is retarded or arrested. Air Flow Indicator, AFM means... moving train is used to generate electric current at the locomotive traction motors, which is then... that is capable of producing its nominally designed retarding force on the train. A car's air brake is...

Sentence Combining: A Rhetorical Perspective.

ERIC Educational Resources Information Center

Daiker, Donald A., Ed.; And Others

The 23 original essays on sentence combining in this volume range in focus from classroom methodology and effectiveness, through theoretical issues and syntactic constructions, to current issues in the field. The essays and their authors are as follows: (1) "The Role of the Elaborated Dominant Nominal in the Measurement of Conceptual and…

75 FR 78688 - Inland Waterways Users Board; Request for Nominations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-16

.... Reflecting preceding selection criteria, the current representation by the ten (10) Board members whose terms.... SUPPLEMENTARY INFORMATION: The selection, service, and appointment of Board members are covered by provisions of Section 302 of Public Law 99-662. The substance of those provisions is as follows: a. Selection. Members...

Genetic variants associated with myocardial infarction risk factors in over 8000 individuals from five ethnic groups: The INTERHEART Genetics Study.

PubMed

Anand, Sonia S; Xie, Changchun; Paré, Guillaume; Montpetit, Alexandre; Rangarajan, Sumathy; McQueen, Matthew J; Cordell, Heather J; Keavney, Bernard; Yusuf, Salim; Hudson, Thomas J; Engert, James C

2009-02-01

Myocardial infarction (MI) is a leading cause of death globally, but specific genetic variants that influence MI and MI risk factors have not been assessed on a global basis. We included 8795 individuals of European, South Asian, Arab, Iranian, and Nepalese origin from the INTERHEART case-control study that genotyped 1536 single-nucleotide polymorphisms (SNPs) from 103 genes. One hundred and two SNPs were nominally associated with MI, but the statistical significance did not remain after adjustment for multiple testing. A subset of 940 SNPs from 69 genes were tested against MI risk factors. One hundred and sixty-three SNPs were nominally associated with a MI risk factor and 13 remained significant after adjusting for multiple testing. Of these 13, 11 were associated with apolipoprotein (Apo) B/A1 levels: 8 SNPs from 3 genes were associated with Apo B, and 3 cholesteryl ester transfer protein SNPs were associated with Apo A1. Seven of 8 of the SNPs associated with Apo B levels were nominally associated with MI (P<0.05), whereas none of the 3 cholesteryl ester transfer protein SNPs were associated with MI (P> or =0.17). Of the 3 SNPs most significantly associated with MI, rs7412, which defines the Apo E2 isoform, was associated with both a lower Apo B/A1 ratio (P=1.0x10(-7)) and lower MI risk (P=0.0004). Two low-density lipoprotein receptor variants, 1 intronic (rs6511720) and 1 in the 3' untranslated region (rs1433099) were both associated with a lower Apo B/A1 ratio (P<1.0x10(-5)) and a lower risk of MI (P=0.004 and P=0.003, respectively). Thirteen common SNPs were associated with MI risk factors. Importantly, SNPs associated with Apo B levels were associated with MI, whereas SNPs associated with Apo A1 levels were not. The Apo E isoform, and 2 common low-density lipoprotein receptor variants (rs1433099 and rs6511720) influence MI risk in this multiethnic sample.

Characterization of nonGaussian atmospheric turbulence for prediction of aircraft response statistics

NASA Technical Reports Server (NTRS)

Mark, W. D.

1977-01-01

Mathematical expressions were derived for the exceedance rates and probability density functions of aircraft response variables using a turbulence model that consists of a low frequency component plus a variance modulated Gaussian turbulence component. The functional form of experimentally observed concave exceedance curves was predicted theoretically, the strength of the concave contribution being governed by the coefficient of variation of the time fluctuating variance of the turbulence. Differences in the functional forms of response exceedance curves and probability densities also were shown to depend primarily on this same coefficient of variation. Criteria were established for the validity of the local stationary assumption that is required in the derivations of the exceedance curves and probability density functions. These criteria are shown to depend on the relative time scale of the fluctuations in the variance, the fluctuations in the turbulence itself, and on the nominal duration of the relevant aircraft impulse response function. Metrics that can be generated from turbulence recordings for testing the validity of the local stationary assumption were developed.

Longitudinal density monitor for the LHC

NASA Astrophysics Data System (ADS)

Jeff, A.; Andersen, M.; Boccardi, A.; Bozyigit, S.; Bravin, E.; Lefevre, T.; Rabiller, A.; Roncarolo, F.; Welsch, C. P.; Fisher, A. S.

2012-03-01

The longitudinal density monitor (LDM) is primarily intended for the measurement of the particle population in nominally empty rf buckets. These so-called satellite or ghost bunches can cause problems for machine protection as well as influencing the luminosity calibration of the LHC. The high dynamic range of the system allows measurement of ghost bunches with as little as 0.01% of the main bunch population at the same time as characterization of the main bunches. The LDM is a single-photon counting system using visible synchrotron light. The photon detector is a silicon avalanche photodiode operated in Geiger mode, which allows the longitudinal distribution of the LHC beams to be measured with a resolution of 90 ps. Results from the LDM are presented, including a proposed method for constructing a 3-dimensional beam density map by scanning the LDM sensor in the transverse plane. In addition, we present a scheme to improve the sensitivity of the system by using an optical switching technique.

In situ study of heavy ion irradiation response of immiscible Cu/Fe multilayers

DOE PAGES

Chen, Youxing; Li, Nan; Bufford, Daniel Charles; ...

2016-04-09

By providing active defect sinks that capture and annihilate radiation induced defect clusters immiscible metallic multilayers with incoherent interfaces can effectively reduce defect density in ion irradiated metals. Although it is anticipated that defect density within the layers should vary as a function of distance to the layer interface, there is, to date, little in situ TEM evidence to validate this hypothesis. In our study monolithic Cu films and Cu/Fe multilayers with individual layer thickness, h, of 100 and 5 nm were subjected to in situ Cu ion irradiation at room temperature to nominally 1 displacement-per-atom inside a transmission electronmore » microscope. Rapid formation and propagation of defect clusters were observed in monolithic Cu, whereas fewer defects with smaller dimensions were generated in Cu/Fe multilayers with smaller h. Moreover, in situ video shows that the cumulative defect density in Cu/Fe 100 nm multilayers indeed varies, as a function of distance to the layer interfaces, supporting a long postulated hypothesis.« less

Elastically frustrated rehybridization: Origin of chemical order and compositional limits in InGaN quantum wells

NASA Astrophysics Data System (ADS)

Lymperakis, L.; Schulz, T.; Freysoldt, C.; Anikeeva, M.; Chen, Z.; Zheng, X.; Shen, B.; Chèze, C.; Siekacz, M.; Wang, X. Q.; Albrecht, M.; Neugebauer, J.

2018-01-01

Nominal InN monolayers grown by molecular beam epitaxy on GaN(0001) are investigated combining in situ reflection high-energy electron diffraction (RHEED), transmission electron microscopy (TEM), and density functional theory (DFT). TEM reveals a chemical intraplane ordering never observed before. Employing DFT, we identify a novel surface stabilization mechanism elastically frustrated rehybridization, which is responsible for the observed chemical ordering. The mechanism also sets an incorporation barrier for indium concentrations above 25% and thus fundamentally limits the indium content in coherently strained layers.

Theoretical Modeling of the Interior Ballistics of the Electrothermal Gun

DTIC Science & Technology

1993-07-01

latter one 19 Table 2.1 Parameters Used for Nominal Data Base (after Oberle [2]). Chamber Volume 97.108 cm 3 Projectile Travel 145 cm Bore Diameter 14...at the time when the plasma supply is completed. When this occurs in the case of instantaneous mixing one has the projectile travel reduced by... Travel 400.0 cm Bore Diameter 4.0 cm Projectile Hass 160 g Plasma Energy 2000000 J Plasma Mass 0.0 g Working Fluid 420 g of H20 Density I g/cm. Bulk

Anode current density distribution in a cusped field thruster

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

Wu, Huan, E-mail: wuhuan58@qq.com; Liu, Hui, E-mail: hlying@gmail.com; Meng, Yingchao

2015-12-15

The cusped field thruster is a new electric propulsion device that is expected to have a non-uniform radial current density at the anode. To further study the anode current density distribution, a multi-annulus anode is designed to directly measure the anode current density for the first time. The anode current density decreases sharply at larger radii; the magnitude of collected current density at the center is far higher compared with the outer annuli. The anode current density non-uniformity does not demonstrate a significant change with varying working conditions.

Feasibility and process scale-up low cost alumina fibers for advanced Re-usable Surface Insulation (RSI)

NASA Technical Reports Server (NTRS)

Pearson, A.

1975-01-01

The objective of this program was to establish feasibility of a process to produce low cost aluminum oxide fibers having sufficient strength, flexibility, and thermal stability for multiple re-use at temperatures to 1480 C in advanced RSI type heat shields for reentry vehicles. Using bench-scale processing apparatus, the Alcoa 'Saphiber' process was successfully modified to produce nominally 8 microns diameter polycrystalline alpha-alumina fiber. Thermal stability was demonstrated in vacuum reheating tests to 1371 C and in atmospheric reheating to 1483 C. Individual fiber properties of strength, modulus, and flexibility were not determined because of friability and short length of the fiber. Rigidized tile produced from fiber of nominally 8, 20 and 40 micron diameter had thermal conductivities significantly higher than those of RSI SiO2 or mullite at relatively low temperature but became comparable above about 1000 C. Tile densities were high due to short fiber length, especially in the coarser diameter fiber. No significant effect of fiber diameter on thermal properties could be determined form the data. Mechanical properties of tiles deteriorated as fiber diameter increased.

Optimization of an electromagnetic linear actuator using a network and a finite element model

NASA Astrophysics Data System (ADS)

Neubert, Holger; Kamusella, Alfred; Lienig, Jens

2011-03-01

Model based design optimization leads to robust solutions only if the statistical deviations of design, load and ambient parameters from nominal values are considered. We describe an optimization methodology that involves these deviations as stochastic variables for an exemplary electromagnetic actuator used to drive a Braille printer. A combined model simulates the dynamic behavior of the actuator and its non-linear load. It consists of a dynamic network model and a stationary magnetic finite element (FE) model. The network model utilizes lookup tables of the magnetic force and the flux linkage computed by the FE model. After a sensitivity analysis using design of experiment (DoE) methods and a nominal optimization based on gradient methods, a robust design optimization is performed. Selected design variables are involved in form of their density functions. In order to reduce the computational effort we use response surfaces instead of the combined system model obtained in all stochastic analysis steps. Thus, Monte-Carlo simulations can be applied. As a result we found an optimum system design meeting our requirements with regard to function and reliability.

77 FR 52330 - Request for Additional Nominations of Candidates for the EPA's Science Advisory Board (SAB...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-29

... person or organization may nominate qualified persons to be considered for appointment to this advisory committee. Individuals may self-nominate. Nominations should be submitted in electronic format (preferred) following the instructions for ``Nominating Experts to the Chemical Assessment Advisory Committee'' provided...

76 FR 71561 - Request for Nominations of Candidates to the EPA's Science Advisory Board (SAB) Chemical...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-18

... nominate qualified persons to be considered for appointment to this advisory committee. Individuals may self-nominate. Nominations should be submitted in electronic format (preferred) following the instructions for ``Nominating Experts to the Chemical Assessment Advisory Committee'' provided on the SAB Web...

Implications of Systematic Nominator Missingness for Peer Nomination Data

ERIC Educational Resources Information Center

Babcock, Ben; Marks, Peter E. L.; van den Berg, Yvonne H. M.; Cillessen, Antonius H. N.

2018-01-01

Missing data are a persistent problem in psychological research. Peer nomination data present a unique missing data problem, because a nominator's nonparticipation results in missing data for other individuals in the study. This study examined the range of effects of systematic nonparticipation on the correlations between peer nomination data when…

Nominalizations in Spanish. Studies in Linguistics and Language Learning, Volume V.

ERIC Educational Resources Information Center

Falk, Julia Sableski

Using methods developed in transformational generative grammar, three types of nominal constructions in Spanish are treated in this paper: Fact nominalizations ("[El] Escribir es agradable"), Manner nominalizations ("El tocar [de la mujer] es agradable"), and Abstract noun nominalizations ("La construccion rapida de esta escuela es dudosa"). While…

The Indian Heritage of America.

ERIC Educational Resources Information Center

Josephy, Alvin M., Jr.

In this book nominated for the National Book Award, the author presents the past, present, and future of the Indians of North, Central, and South America with current archaeological findings which add to the knowledge about Indians. As noted, the volume contains information from the works of a large number of people who, since the time of…

Forests of Michigan, 2013

Treesearch

Scott A. Pugh

2014-01-01

This publication provides an overview of forest resources in Michigan based on inventories conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program of the Northern Research Station. Since 1999, FIA has employed an annual inventory measuring data on a nominal 20 percent of sample plots each year. For the 2013 inventory, estimates for current...

Forests of Vermont, 2013

Treesearch

Randall S. Morin; Scott A. Pugh

2014-01-01

This publication provides an overview of forest resources in Vermont based on inventories conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program of the Northern Research Station. Since 1999, FIA has employed an annual inventory measuring data on a nominal 20 percent of sample plots each year. For the 2013 inventory, estimates for current...

77 FR 47397 - Request for Nominations of Specific Drug/Biologic Product(s) That Could Be Brought Before the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-08

... Administration's (FDA) Office of Hematology and Oncology Products invites the public to suggest one or more... Subcommittee on possible directions for their current or future pediatric oncology product development. DATES... subject line ``Suggested Product for 2012 Pediatric Oncology Subcommittee of ODAC.'' FOR FURTHER...

78 FR 17717 - Notice of Availability of the Record of Decision for the EDF Renewable Energy Desert Harvest...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-22

... decommission an up to 150-megawatt (MW), nominal capacity, alternating current, solar photovoltaic (PV) energy... Solar Field Project and California Desert Conservation Area Plan Amendment, Riverside County, California... California Desert Conservation Area (CDCA) Plan, for the Desert Harvest Solar Project (DHSP), in Riverside...

Hot mix asphalt research investigation for Connecticut : part A - reduction in the number Of superpave mix design levels.

DOT National Transportation Integrated Search

2009-07-01

This research is the first in a series of investigated topics surrounding hot mix asphalt in Connecticut. : Currently there are at least 12 different mix designs that need to be developed by producers of HMA with : four traffic levels and three nomin...

Differential Effects of Reinforcement on the Self-Monitoring of On-Task Behavior

ERIC Educational Resources Information Center

Otero, Tiffany L.; Haut, Jillian M.

2016-01-01

In the current study, the differential effects of reinforcement on a self-monitoring intervention were evaluated. Three students nominated by their teachers for having a marked difficultly maintaining on-task behaviors participated in the study. Using an alternating treatments single-case design to assess self-monitoring with and without…

75 FR 5769 - Inland Waterways Users Board; Request for Nominations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-04

... preceding selection criteria, the current representation by the one (1) Board member whose term has expired... selection, service, and appointment of Board members are covered by provisions of Section 302 of Public Law 99-662. The substance of those provisions is as follows: a. Selection. Members are to be selected...

Underwater sound radiation patterns of contemporary merchant ships

NASA Astrophysics Data System (ADS)

Gassmann, M.; Wiggins, S. M.; Hildebrand, J. A.

2016-12-01

Merchant ships radiate underwater sound as an unintended by-product of their operation and as consequence contribute significantly to low-frequency, man-made noise in the ocean. Current measurement standards for the description of underwater sound from ships (ISO 17208-1:2016 and ANSI S12.64-2009) require nominal hydrophone depths of 15°, 30° and 45° at the starboard and portside of the test vessel.To opportunistically study the underwater sound of contemporary merchant ships that were tracked by the Automatic Identification System (AIS), an array of seven high-frequency acoustic recording packages (HARPs) with a sampling frequency of 200 kHz was deployed in the Santa Barbara Channel in the primary outgoing shipping lane for the port of Los Angeles and Long Beach. The vertical and horizontal aperture of the array allowed for starboard and portside measurements at all standard-required nominal hydrophone depths in addition to measurements taken at the keel aspect. Based on these measurements, frequency-dependent radiation patterns of contemporary merchant ships were estimated and used to evaluate current standards for computing ship source levels.

Development of the Orion Crew Module Static Aerodynamic Database. Par 2; Supersonic/Subsonic

NASA Technical Reports Server (NTRS)

Bibb, Karen L.; Walker, Eric L.; Brauckmann, Gregory J.; Robinson, Phil

2011-01-01

This work describes the process of developing the nominal static aerodynamic coefficients and associated uncertainties for the Orion Crew Module for Mach 8 and below. The database was developed from wind tunnel test data and computational simulations of the smooth Crew Module geometry, with no asymmetries or protuberances. The database covers the full range of Reynolds numbers seen in both entry and ascent abort scenarios. The basic uncertainties were developed as functions of Mach number and total angle of attack from variations in the primary data as well as computations at lower Reynolds numbers, on the baseline geometry, and using different flow solvers. The resulting aerodynamic database represents the Crew Exploration Vehicle Aerosciences Project's best estimate of the nominal aerodynamics for the current Crew Module vehicle.

Autonomous Operations System: Development and Application

NASA Technical Reports Server (NTRS)

Toro Medina, Jaime A.; Wilkins, Kim N.; Walker, Mark; Stahl, Gerald M.

2016-01-01

Autonomous control systems provides the ability of self-governance beyond the conventional control system. As the complexity of mechanical and electrical systems increases, there develops a natural drive for developing robust control systems to manage complicated operations. By closing the bridge between conventional automated systems to knowledge based self-awareness systems, nominal control of operations can evolve into relying on safe critical mitigation processes to support any off-nominal behavior. Current research and development efforts lead by the Autonomous Propellant Loading (APL) group at NASA Kennedy Space Center aims to improve cryogenic propellant transfer operations by developing an automated control and health monitoring system. As an integrated systems, the center aims to produce an Autonomous Operations System (AOS) capable of integrating health management operations with automated control to produce a fully autonomous system.

Robust model predictive control for constrained continuous-time nonlinear systems

NASA Astrophysics Data System (ADS)

Sun, Tairen; Pan, Yongping; Zhang, Jun; Yu, Haoyong

2018-02-01

In this paper, a robust model predictive control (MPC) is designed for a class of constrained continuous-time nonlinear systems with bounded additive disturbances. The robust MPC consists of a nonlinear feedback control and a continuous-time model-based dual-mode MPC. The nonlinear feedback control guarantees the actual trajectory being contained in a tube centred at the nominal trajectory. The dual-mode MPC is designed to ensure asymptotic convergence of the nominal trajectory to zero. This paper extends current results on discrete-time model-based tube MPC and linear system model-based tube MPC to continuous-time nonlinear model-based tube MPC. The feasibility and robustness of the proposed robust MPC have been demonstrated by theoretical analysis and applications to a cart-damper springer system and a one-link robot manipulator.

International Space Station Major Constituent Analyzer On-Orbit Performance

NASA Technical Reports Server (NTRS)

Gardner, Ben D.; Erwin, Phillip M.; Thoresen, Souzan; Granahan, John; Matty, Chris

2012-01-01

The Major Constituent Analyzer is a mass spectrometer based system that measures the major atmospheric constituents on the International Space Station. A number of limited-life components require periodic changeout, including the ORU 02 analyzer and the ORU 08 Verification Gas Assembly. Over the past two years, two ORU 02 analyzer assemblies have operated nominally while two others have experienced premature on-orbit failures. These failures as well as nominal performances demonstrate that ORU 02 performance remains a key determinant of MCA performance and logistical support. It can be shown that monitoring several key parameters can maximize the capacity to monitor ORU health and properly anticipate end of life. Improvements to ion pump operation and ion source tuning are expected to improve lifetime performance of the current ORU 02 design.

Taxonomic status of Myotis occultus

USGS Publications Warehouse

Valdez, E.W.; Choate, Jerry R.; Bogan, M.A.; Yates, Terry L.

1999-01-01

The taxonomic status of the Arizona myotis (Myotis occultus) is uncertain. Although the taxon was described as a distinct species and currently is regarded as such by some authors, others have noted what they interpreted as intergradation with the little brown bat (M. lucifugus carissima) near the Colorado-New Mexico state line. In this study, we used protein electrophoresis to compare bats of these nominal taxa. We examined 20 loci from 142 specimens referable to M. occultus and M. lucifugus from New Mexico, Colorado, and Wyoming. Nine of the 20 loci were polymorphic. Results show that there were high similarities among samples, no fixed alleles, and minor divergence from Hardy-Weinberg equilibrium. Our results suggest that the two nominal taxa represent only one species and that M. occultus should be regarded as a subspecies of M. lucifugus.

An on-board near-optimal climb-dash energy management

NASA Technical Reports Server (NTRS)

Weston, A. R.; Cliff, E. M.; Kelley, H. J.

1982-01-01

On-board real time flight control is studied in order to develop algorithms which are simple enough to be used in practice, for a variety of missions involving three dimensional flight. The intercept mission in symmetric flight is emphasized. Extensive computation is required on the ground prior to the mission but the ensuing on-board exploitation is extremely simple. The scheme takes advantage of the boundary layer structure common in singular perturbations, arising with the multiple time scales appropriate to aircraft dynamics. Energy modelling of aircraft is used as the starting point for the analysis. In the symmetric case, a nominal path is generated which fairs into the dash or cruise state. Feedback coefficients are found as functions of the remaining energy to go (dash energy less current energy) along the nominal path.

Using multi-scale entropy and principal component analysis to monitor gears degradation via the motor current signature analysis

NASA Astrophysics Data System (ADS)

Aouabdi, Salim; Taibi, Mahmoud; Bouras, Slimane; Boutasseta, Nadir

2017-06-01

This paper describes an approach for identifying localized gear tooth defects, such as pitting, using phase currents measured from an induction machine driving the gearbox. A new tool of anomaly detection based on multi-scale entropy (MSE) algorithm SampEn which allows correlations in signals to be identified over multiple time scales. The motor current signature analysis (MCSA) in conjunction with principal component analysis (PCA) and the comparison of observed values with those predicted from a model built using nominally healthy data. The Simulation results show that the proposed method is able to detect gear tooth pitting in current signals.

Occupational therapy with people with depression: using nominal group technique to collate clinician opinion.

PubMed

Hitch, Danielle; Taylor, Michelle; Pepin, Genevieve

2015-05-01

This aim of this study was to obtain a consensus from clinicians regarding occupational therapy for people with depression, for the assessments and practices they use that are not currently supported by research evidence directly related to functional performance. The study also aimed to discover how many of these assessments and practices were currently supported by research evidence. Following a previously reported systematic review of assessments and practices used in occupational therapy for people with depression, a modified nominal group technique was used to discover which assessments and practices occupational therapists currently utilize. Three online surveys gathered initial data on therapeutic options (survey 1), which were then ranked (survey 2) and re-ranked (survey 3) to gain the final consensus. Twelve therapists completed the first survey, whilst 10 clinicians completed both the second and third surveys. Only 30% of the assessments and practices identified by the clinicians were supported by research evidence. A consensus was obtained on a total of 35 other assessments and interventions. These included both occupational-therapy-specific and generic assessments and interventions. Principle conclusion. Very few of the assessments and interventions identified were supported by research evidence directly related to functional performance. While a large number of options were generated, the majority of these were not occupational therapy specific.

Research note: attitudes of teachers and undergraduate students regarding three augmentative and alternative communication modalities.

PubMed

Schäfer, Martina Christina Marion; Sutherland, Dean; McLay, Laurie; Achmadi, Donna; van der Meer, Larah; Sigafoos, Jeff; Lancioni, Giulio E; O'Reilly, Mark F; Schlosser, Ralf W; Marschik, Peter B

2016-12-01

The social validity of different communication modalities is a potentially important variable to consider when designing augmentative and alternative communication (AAC) interventions. To assess the social validity of three AAC modes (i.e., manual signing, picture exchange, and an iPad ® -based speech-generating device), we asked 59 undergraduate students (pre-service teachers) and 43 teachers to watch a video explaining each mode. They were then asked to nominate the mode they perceived to be easiest to learn as well as the most intelligible, effective, and preferred. Participants were also asked to list the main reasons for their nominations and report on their experience with each modality. Most participants (68-86%) nominated the iPad-based speech-generating device (SGD) as easiest to learn, as well as the most intelligible, effective, and preferred. This device was perceived to be easy to understand and use and to have familiar and socially acceptable technology. Results suggest that iPad-based SGDs were perceived as more socially valid among this sample of teachers and undergraduate students. Information of this type may have some relevance to designing AAC supports for people who use AAC and their current and future potential communication partners.

An Intelligent Decision System for Intraoperative Somatosensory Evoked Potential Monitoring.

PubMed

Fan, Bi; Li, Han-Xiong; Hu, Yong

2016-02-01

Somatosensory evoked potential (SEP) is a useful, noninvasive technique widely used for spinal cord monitoring during surgery. One of the main indicators of a spinal cord injury is the drop in amplitude of the SEP signal in comparison to the nominal baseline that is assumed to be constant during the surgery. However, in practice, the real-time baseline is not constant and may vary during the operation due to nonsurgical factors, such as blood pressure, anaesthesia, etc. Thus, a false warning is often generated if the nominal baseline is used for SEP monitoring. In current practice, human experts must be used to prevent this false warning. However, these well-trained human experts are expensive and may not be reliable and consistent due to various reasons like fatigue and emotion. In this paper, an intelligent decision system is proposed to improve SEP monitoring. First, the least squares support vector regression and multi-support vector regression models are trained to construct the dynamic baseline from historical data. Then a control chart is applied to detect abnormalities during surgery. The effectiveness of the intelligent decision system is evaluated by comparing its performance against the nominal baseline model by using the real experimental datasets derived from clinical conditions.

Data Mining for Anomaly Detection

NASA Technical Reports Server (NTRS)

Biswas, Gautam; Mack, Daniel; Mylaraswamy, Dinkar; Bharadwaj, Raj

2013-01-01

The Vehicle Integrated Prognostics Reasoner (VIPR) program describes methods for enhanced diagnostics as well as a prognostic extension to current state of art Aircraft Diagnostic and Maintenance System (ADMS). VIPR introduced a new anomaly detection function for discovering previously undetected and undocumented situations, where there are clear deviations from nominal behavior. Once a baseline (nominal model of operations) is established, the detection and analysis is split between on-aircraft outlier generation and off-aircraft expert analysis to characterize and classify events that may not have been anticipated by individual system providers. Offline expert analysis is supported by data curation and data mining algorithms that can be applied in the contexts of supervised learning methods and unsupervised learning. In this report, we discuss efficient methods to implement the Kolmogorov complexity measure using compression algorithms, and run a systematic empirical analysis to determine the best compression measure. Our experiments established that the combination of the DZIP compression algorithm and CiDM distance measure provides the best results for capturing relevant properties of time series data encountered in aircraft operations. This combination was used as the basis for developing an unsupervised learning algorithm to define "nominal" flight segments using historical flight segments.

Electrical characterization of the flowing afterglow of N{sub 2} and N{sub 2}/O{sub 2} microwave plasmas at reduced pressure

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

Afonso Ferreira, J.; Stafford, L., E-mail: luc.stafford@umontreal.ca; Leonelli, R.

2014-04-28

A cylindrical Langmuir probe was used to analyze the spatial distribution of the number density of positive ions and electrons as well as the electron energy distribution function (EEDF) in the flowing afterglow of a 6 Torr N{sub 2} and N{sub 2}/O{sub 2} plasma sustained by a propagating electromagnetic surface wave in the microwave regime. In pure N{sub 2} discharges, ion densities were in the mid 10{sup 14} m{sup −3} in the pink afterglow and in the mid 10{sup 12} m{sup −3} early in the late afterglow. In both pink and late afterglows, the ion population was much higher than the electron population,more » indicating non-macroscopically neutral media. The EEDF was close to a Maxwellian with an electron temperature of 0.5 ± 0.1 eV, except in the pink afterglow where the temperature rose to 1.1 ± 0.2 eV. This latter behavior is ascribed to N{sub 2} vibration-vibration pumping in the pink afterglow that increases the concentration of high N{sub 2} vibrational states and thus rises the electron temperature by vibration-electron collisions. After addition of small amounts of O{sub 2} in the nominally pure N{sub 2} discharge, the charged particles densities and average electron energy first strongly increased and then decreased with increasing O{sub 2} concentration. Based on these data and the evolution of the N{sub 2}{sup +}(B) band emission intensities, it is concluded that a significant change in the positive ion composition of the flowing afterglow occurs, going from N{sub 2}{sup +} in nominally pure N{sub 2} discharges to NO{sup +} after addition of trace amounts of O{sub 2} in N{sub 2}.« less

Radicals mediated magnetism in Ar plasma treated high-density polyethylene

NASA Astrophysics Data System (ADS)

Orendáč, M.; Čižmár, E.; Kažiková, V.; Orendáčová, A.; Řezníčková, A.; Kolská, Z.; Švorčík, V.

2018-05-01

Electron-spin resonance of high-density polyethylene treated by Ar plasma at 300 K was performed in X-band at temperatures from 2.1 K to 290 K. The observed spectra suggest presence of allyl radicals, whereas the central peak may be attributed to polyenyl radicals or dangled bonds. Pronounced narrowing of the resonance line observed above glassy temperature of polyethylene may be ascribed to thermally activated motional effect with the activation energy Ea /kB = 160 K. The absence of strong exchange interactions is suggested by negligible exchange narrowing found at 2.1 K. The suggestion is supported by the analysis of the temperature dependence of the intensity at low temperatures, which is explicable assuming the coexistence of non-interacting radicals and S = 1/2 dimers with a distribution of antiferromagnetic couplings varying from 2 K to nominally 25 K.

75 FR 43933 - Request for nominations for members to serve on National Institute of Standards and Technology...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-27

... duties. Selection of ISPAB members will not be limited to individuals who are nominated. Nominations that.... Selection of MEP Advisory Board members will not be limited to individuals who are nominated. Nominations... in its official role as the private sector policy advisor of the Institute is concerned. Each such...

77 FR 40332 - Request for Nominations for Members To Serve on National Institute of Standards and Technology...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-09

... duties. Selection of ISPAB members will not be limited to individuals who are nominated. Nominations that... to individuals who are nominated. Nominations that are received and meet the requirements will be... policy advisor of NIST is concerned. Each such report shall identify areas of program emphasis for NIST...

78 FR 67121 - Request for Nominations for Members To Serve on National Institute of Standards and Technology...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-08

... to individuals who are nominated. Nominations that are received and meet the requirements will be.... Selection of MEP Advisory Board members will not be limited to individuals who are nominated. Nominations... official role as the private sector policy adviser of NIST is concerned. Each such report shall identify...

Effect of charcoal doping on the superconducting properties of MgB 2 bulk

NASA Astrophysics Data System (ADS)

Kim, N. K.; Tan, K. S.; Jun, B.-H.; Park, H. W.; Joo, J.; Kim, C.-J.

2008-09-01

The effect of charcoal doping on the superconducting properties of in situ processed MgB 2 bulk samples was investigated. To understand the size effect of the dopant the charcoal powder was attrition milled for 1 h, 3 h and 6 h using ZrO 2 balls. The milled charcoal powders were mixed with magnesium and boron powders to a nominal composition of Mg(B 0.975C 0.025) 2. The Mg(B 0.975C 0.025) 2 compacts were heat-treated at 900 °C for 0.5 h in flowing Ar atmosphere. Magnetic susceptibility for the samples showed that the superconducting transition temperature ( Tc) decreased as the size of the charcoal powder decreased. The critical current density ( Jc) of Mg(B 0.975C 0.025) 2 prepared using large size charcoal powder was lower than that of the undoped MgB 2. However, a crossover of Jc value was observed at high magnetic fields of about 4 T in Mg(B 0.975C 0.025) 2 prepared using small size charcoal powder. Carbon diffusion into the boron site was easier and gave the Jc increase effect when the small size charcoal was used as a dopant.

The Copernicus project

NASA Technical Reports Server (NTRS)

Barnstable, Bob; Polte, Hans; Kepes, Paul; Walker, Kevin; Jacobs, Jeff; Williams, Stephen

1990-01-01

The Copernicus spacecraft, to be launched on May 4, 2009, is designed for scientific exploration of the planet Pluto. The main objectives of this exploration is to accurately determine the mass, density, and composition of the two bodies in the Pluto-Charon system. A further goal of the exploration is to obtain precise images of the system. The spacecraft will be designed for three axis stability control. It will use the latest technological advances to optimize the performance, reliability, and cost of the spacecraft. Due to the long duration of the mission, nominally 12.6 years, the spacecraft will be powered by a long lasting radioactive power source. Although this type of power may have some environmental drawbacks, currently it is the only available source that is suitable for this mission. The planned trajectory provides flybys of Jupiter and Saturn. These flybys provide an opportunity for scientific study of these planets in addition to Pluto. The information obtained on these flybys will supplement the data obtained by the Voyager and Galileo missions. The topics covered include: (1) scientific instrumentation; (2) mission management, planning, and costing; (3) power and propulsion system; (4) structural subsystem; (5) command, control, and communication; and (6) attitude and articulation control.

Analyzing Radio-Frequency Coverage for the ISS

NASA Technical Reports Server (NTRS)

Bolen, Steven M.; Sham, Catherine C.

2007-01-01

The Interactive Coverage Analysis Tool (iCAT) is an interactive desktop computer program serving to (1) support planning of coverage, and management of usage of frequencies, of current and proposed radio communication systems on and near the International Space Station (ISS) and (2) enable definition of requirements for development of future such systems. The iCAT can also be used in design trade studies for other (both outer-space and terrestrial) communication systems. A user can enter the parameters of a communication-system link budget in a table in a worksheet. The nominal (onaxis) link values for the bit-to-noise-energy ratio, received isotropic power (RIP), carrier-to-noise ratio (C/N), power flux density (PFD), and link margin of the system are calculated and displayed in the table. Plots of field gradients for the RIP, C/N, PFD, and link margin are constructed in an ISS coordinate system, at a specified link range, for both the forward and return link parameters, and are displayed in worksheets. The forward and reverse link antenna gain patterns are also constructed and displayed. Line-of-sight (LOS) obstructions can be both incorporated into the gradient plots and displayed on separate plots.

Measurement of Density, Sound Velocity, Surface Tension, and Viscosity of Freely Suspended Supercooled Liquids

NASA Technical Reports Server (NTRS)

Trinh, E. H.

1995-01-01

Non-contact methods have been implemented in conjunction with levitation techniques to carry out the measurement of the macroscopic properties of liquids significantly cooled below their nominal melting point. Free suspension of the sample and remote methods allow the deep excursion into the metastable liquid state and the determination of its thermophysical properties. We used this approach to investigate common substances such as water, o-terphenyl, succinonitrile, as well as higher temperature melts such as molten indium, aluminum and other metals. Although these techniques have thus far involved ultrasonic, electromagnetic, and more recently electrostatic levitation, we restrict our attention to ultrasonic methods in this paper. The resulting magnitude of maximum thermal supercooling achieved have ranged between 10 and 15% of the absolute temperature of the melting point for the materials mentioned above. The physical properties measurement methods have been mostly novel approaches, and the typical accuracy achieved have not yet matched their standard equivalent techniques involving contained samples and invasive probing. They are currently being refined, however, as the levitation techniques become more widespread, and as we gain a better understanding of the physics of levitated liquid samples.

Miniaturized Ion and Neutral Mass Spectrometer for CubeSat Atmospheric Measurements

NASA Technical Reports Server (NTRS)

Rodriguez, M.; Paschalidis, N.; Jones, S.; Sittler, E.; Chornay, D.; Uribe, P.; Cameron, T.

2016-01-01

To increase the number of single point in-situ measurements of thermosphere and exosphere ion and neutral composition and density, miniaturized instrumentation is in high demand to take advantage of the increasing platform opportunities available in the smallsat/cubesat industry. The INMS (Ion-Neutral Mass Spectrometer) addresses this need by providing simultaneous measurements of both the neutral and ion environment, essentially providing two instruments in one compact model. The 1.3U volume, 570 gram, 1.8W nominal power INMS instrument makes implementation into cubesat designs (3U and above) practical and feasible. With high dynamic range (0.1-500eV), mass dynamic range of 1-40amu, sharp time resolution (0.1s), and mass resolution of MdM16, the INMS instrument addresses the atmospheric science needs that otherwise would have required larger more expensive instrumentation. INMS-v1 (version 1) launched on Exocube (CalPoly 3U cubesat) in 2015 and INMS-v2 (version 2) is scheduled to launch on Dellingr (GSFC 6U cubesat) in 2017. New versions of INMS are currently being developed to increase and add measurement capabilities, while maintaining its smallsat/cubesat form.

Measurement of density, sound velocity, surface tension, and viscosity of freely suspended supercooled liquids

NASA Astrophysics Data System (ADS)

Trinh, E. H.; Ohsaka, K.

1995-03-01

Noncontact methods have been implemented in conjunction with levitation techniques to carry out the measurement of the macroscopic properties of liquids significantly cooled below their nominal melting point. Free suspension of the sample and remote methods allow the deep excursion into the metastable liquid state and the determination of its thermophysical properties. We used this approach to investigate common substances such as water, v-terphenyl. succinonitrile, as well as higher temperature melts such as molten indium, aluminum, and other metals. Although these techniques have thus far involved ultrasonic, eletromagnetic, and more recently electrostatic levitation, we restrict our attention to ultrasonic methods in this paper. The resulting magnitude of maximum thermal supercooling achieved has ranged between 10% and 15% of the absolute temperature of the melting point for the materials mentioned above. The methods for measuring the physical properties have been mostly novel approaches, and the typical accuracy achieved has not yet matched the standard equivalent techniques involving contained samples and invasive probing. They are currently being refined, however, as the levitation techniques become more widespread and as we gain a better understanding of the physics of levitated liquid samples.

Current transformer model with hysteresis for improving the protection response in electrical transmission systems

NASA Astrophysics Data System (ADS)

Matussek, Robert; Dzienis, Cezary; Blumschein, Jörg; Schulte, Horst

2014-12-01

In this paper, a generic enhanced protection current transformer (CT) model with saturation effects and transient behavior is presented. The model is used for the purpose of analysis and design of power system protection algorithms. Three major classes of protection CT have been modeled which all take into account the nonlinear inductance with remanence effects. The transient short-circuit currents in power systems are simulated under CT saturation condition. The response of a common power system protection algorithm with respect to robustness to nominal parameter variations and sensitivity against maloperation is demonstrated by simulation studies.

Conceptual Design for CLIC Gun Pulser

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

Tang, Tao

The Compact Linear Collider (CLIC) is a proposed future electron-positron collider, designed to perform collisions at energies from 0.5 to 5 TeV, with a nominal design optimized for 3 TeV (Dannheim, 2012). The Drive Beam Accelerator consists of a thermionic DC gun, bunching section and an accelerating section. The thermionic gun needs deliver a long (~143us) pulse of current into the buncher. A pulser is needed to drive grid of the gun to generate a stable current output. This report explores the requirements of the gun pulser and potential solutions to regulate grid current.

Self-bunching electron guns

NASA Astrophysics Data System (ADS)

Mako, Frederick M.; Len, L. K.

1999-05-01

We report on three electron gun projects that are aimed at power tube and injector applications. The purpose of the work is to develop robust electron guns which produce self-bunched, high-current-density beams. We have demonstrated, in a microwave cavity, self-bunching, cold electron emission, long life, and tolerance to contamination. The cold process is based on secondary electron emission. FMT has studied using simulation codes the resonant bunching process which gives rise to high current densities (0.01-5 kA/cm2), high charge bunches (up to 500 nC/bunch), and short pulses (1-100 ps) for frequencies from 1 to 12 GHz. The beam pulse width is nominally ˜5% of the rf period. The first project is the L-Band Micro-Pulse Gun (MPG). Measurements show ˜40 ps long micro-bunches at ˜20 A/cm2 without contamination due to air exposure. Lifetime testing has been carried out for about 18 months operating at 1.25 GHz for almost 24 hours per day at a repetition rate of 300 Hz and 5 μs-long macro-pulses. Approximately 5.8×1013 micro-bunches or 62,000 coulombs have passed through this gun and it is still working fine. The second project, the S-Band MPG, is now operational. It is functioning at a frequency of 2.85 GHz, a repetition rate of 30 Hz, with a 2 μs-long macro-pulse. It produces about 45 A in the macro-pulse. The third project is a 34.2 GHz frequency-multiplied source driven by an X-Band MPG. A point design was performed at an rf output power of 150 MW at 34.2 GHz. The resulting system efficiency is 53% and the gain is 60 dB. The system efficiency includes the input cavity efficiency, input driver efficiency (a 50 MW klystron at 11.4 GHz), output cavity efficiency, and the post-acceleration efficiency.

76 FR 39379 - Request for Nominations for Members To Serve on National Institute of Standards and Technology...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-06

... will not be limited to individuals who are nominated. Nominations that are received and meet the... individuals who are nominated. Nominations that are received and meet the requirements will be kept on file to... in its official role as the private sector policy advisor of the Institute is concerned. Each such...

Conceptual and linguistic representations of kinds and classes

PubMed Central

Prasada, Sandeep; Hennefield, Laura; Otap, Daniel

2013-01-01

We investigate the hypothesis that our conceptual systems provide two formally distinct ways of representing categories by investigating the manner in which lexical nominals (e.g., tree, picnic table) and phrasal nominals (e.g., black bird, birds that like rice) are interpreted. Four experiments found that lexical nominals may be mapped onto kind representations whereas phrasal nominals map onto class representations but not kind representations. Experiment 1 found that phrasal nominals, unlike lexical nominals, are mapped onto categories whose members need not be of a single kind. Experiments 2 and 3 found that categories named by lexical nominals enter into both class inclusion and kind hierarchies and thus support both class inclusion (is a) and kind specification (kind of) relations, whereas phrasal nominals map onto class representations which support only class inclusion relations. Experiment 4 showed that the two types of nominals represent hierarchical relations in different ways. Phrasal nominals (e.g., white bear) are mapped onto classes that have criteria of membership in addition to those specified by the class picked out by the head noun of the phrase (e.g., bear). In contrast, lexical nominals (e.g., polar bear) specify one way to meet the criteria specified by the more general kind concept (e.g., bear). Implications for the language-conceptual system interface, representation of hierarchical relations, lexicalization, and theories of conceptual combination are discussed. PMID:22671567

7 CFR 917.18 - Nomination of commodity committee members of the Control Committee.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Administrative Bodies § 917.18 Nomination of commodity committee members of the Control Committee. Nominations... committee shall be entitled to nominate shall be based upon the proportion that the previous three fiscal...

7 CFR 917.18 - Nomination of commodity committee members of the Control Committee.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Administrative Bodies § 917.18 Nomination of commodity committee members of the Control Committee. Nominations... committee shall be entitled to nominate shall be based upon the proportion that the previous three fiscal...

7 CFR 917.18 - Nomination of commodity committee members of the Control Committee.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Administrative Bodies § 917.18 Nomination of commodity committee members of the Control Committee. Nominations... committee shall be entitled to nominate shall be based upon the proportion that the previous three fiscal...

7 CFR 917.18 - Nomination of commodity committee members of the Control Committee.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Administrative Bodies § 917.18 Nomination of commodity committee members of the Control Committee. Nominations... committee shall be entitled to nominate shall be based upon the proportion that the previous three fiscal...

7 CFR 917.18 - Nomination of commodity committee members of the Control Committee.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Administrative Bodies § 917.18 Nomination of commodity committee members of the Control Committee. Nominations... committee shall be entitled to nominate shall be based upon the proportion that the previous three fiscal...

A preliminary investigation of high dose ion irradiation response of a lanthana-bearing nanostructured ferritic steel processed via spark plasma sintering

NASA Astrophysics Data System (ADS)

Pasebani, Somayeh; Charit, Indrajit; Guria, Ankan; Wu, Yaqiao; Burns, Jatuporn; Butt, Darryl P.; Cole, James I.; Shao, Lin

2017-11-01

A nanostructured ferritic steel with nominal composition of Fe-14Cr-1Ti-0.3Mo-0.5La2O3 (wt.%) was irradiated with Fe+2 ions at 475 °C for 100, 200, 300 and 400 dpa. Grain coarsening was observed for the samples irradiated for 200-400 dpa resulting in an increase of the average grain size from 152 nm to 620 nm. Growth of submicron grains at higher radiation doses is due to decreased pinning effect imparted by Cr-O rich nanoparticles (NPs) that underwent coarsening via Ostwald ripening. Dislocation density consistently increased with increasing irradiation dose at 300 and 400 dpa. The mean radius of lanthanum-containing nanoclusters (NCs) decreased and their number density increased above 200 dpa, which is likely due to solutes ejection caused by ballistic dissolution and irradiation-enhanced diffusion. Chromium, titanium, oxygen and lanthanum content of nanoclusters irradiated at 200 dpa and higher got reduced by almost half the initial value. The reduction in size of the nanoclusters accompanied with their higher number density and higher dislocation density led to significant radiation hardening with increasing irradiation dose.

Application of Accelerometer Data to Mars Odyssey Aerobraking and Atmospheric Modeling

NASA Technical Reports Server (NTRS)

Tolson, R. H.; Keating, G. M.; George, B. E.; Escalera, P. E.; Werner, M. R.; Dwyer, A. M.; Hanna, J. L.

2002-01-01

Aerobraking was an enabling technology for the Mars Odyssey mission even though it involved risk due primarily to the variability of the Mars upper atmosphere. Consequently, numerous analyses based on various data types were performed during operations to reduce these risk and among these data were measurements from spacecraft accelerometers. This paper reports on the use of accelerometer data for determining atmospheric density during Odyssey aerobraking operations. Acceleration was measured along three orthogonal axes, although only data from the component along the axis nominally into the flow was used during operations. For a one second count time, the RMS noise level varied from 0.07 to 0.5 mm/s2 permitting density recovery to between 0.15 and 1.1 kg per cu km or about 2% of the mean density at periapsis during aerobraking. Accelerometer data were analyzed in near real time to provide estimates of density at periapsis, maximum density, density scale height, latitudinal gradient, longitudinal wave variations and location of the polar vortex. Summaries are given of the aerobraking phase of the mission, the accelerometer data analysis methods and operational procedures, some applications to determining thermospheric properties, and some remaining issues on interpretation of the data. Pre-flight estimates of natural variability based on Mars Global Surveyor accelerometer measurements proved reliable in the mid-latitudes, but overestimated the variability inside the polar vortex.

INDUCTIVE SYSTEM HEALTH MONITORING WITH STATISTICAL METRICS

NASA Technical Reports Server (NTRS)

Iverson, David L.

2005-01-01

Model-based reasoning is a powerful method for performing system monitoring and diagnosis. Building models for model-based reasoning is often a difficult and time consuming process. The Inductive Monitoring System (IMS) software was developed to provide a technique to automatically produce health monitoring knowledge bases for systems that are either difficult to model (simulate) with a computer or which require computer models that are too complex to use for real time monitoring. IMS processes nominal data sets collected either directly from the system or from simulations to build a knowledge base that can be used to detect anomalous behavior in the system. Machine learning and data mining techniques are used to characterize typical system behavior by extracting general classes of nominal data from archived data sets. In particular, a clustering algorithm forms groups of nominal values for sets of related parameters. This establishes constraints on those parameter values that should hold during nominal operation. During monitoring, IMS provides a statistically weighted measure of the deviation of current system behavior from the established normal baseline. If the deviation increases beyond the expected level, an anomaly is suspected, prompting further investigation by an operator or automated system. IMS has shown potential to be an effective, low cost technique to produce system monitoring capability for a variety of applications. We describe the training and system health monitoring techniques of IMS. We also present the application of IMS to a data set from the Space Shuttle Columbia STS-107 flight. IMS was able to detect an anomaly in the launch telemetry shortly after a foam impact damaged Columbia's thermal protection system.

Comparing acceptance and rejection in the classroom interaction of students who stutter and their peers: A social network analysis.

PubMed

Adriaensens, Stefanie; Van Waes, Sara; Struyf, Elke

2017-06-01

Recent work has reported adverse effects of students' stuttering on their social and emotional functioning at school. Yet, few studies have provided an in-depth examination of classroom interaction of students who stutter (SWS). The current study uses a network perspective to compare acceptance and rejection in the classroom interaction between SWS and their peers in secondary education. The sample comprised 22 SWS and 403 non-stuttering peers (22 classes) of secondary education in Flanders (Belgium). Students' nominations regarding three acceptance and three rejection criteria were combined. Social network analysis offered procedures that considered direct and indirect interaction between all classmates. We found few significant differences: SWS and their peers were distributed similarly across positive and negative status groups. Both considered and were considered by, on average, six or seven classmates as 'a friend', who they liked and could count on, and nominated or were nominated by one or two classmates as 'no friend', somebody who they disliked and could not count on. On average, SWS and their classmates also did not differ in terms of structural position in the class group (degree, closeness and betweenness), reciprocated rejection, and clique size. However, SWS do tend to be slightly more stringent or more careful in nominating peers, which led to fewer reciprocated friendships. Our results suggest that SWS are quite accepted by peers in secondary education in Flanders. Such positive peer interaction can create a supportive and encouraging climate for SWS to deal with specific challenges. Copyright © 2017 Elsevier Inc. All rights reserved.

Anomaly Detection for Next-Generation Space Launch Ground Operations

NASA Technical Reports Server (NTRS)

Spirkovska, Lilly; Iverson, David L.; Hall, David R.; Taylor, William M.; Patterson-Hine, Ann; Brown, Barbara; Ferrell, Bob A.; Waterman, Robert D.

2010-01-01

NASA is developing new capabilities that will enable future human exploration missions while reducing mission risk and cost. The Fault Detection, Isolation, and Recovery (FDIR) project aims to demonstrate the utility of integrated vehicle health management (IVHM) tools in the domain of ground support equipment (GSE) to be used for the next generation launch vehicles. In addition to demonstrating the utility of IVHM tools for GSE, FDIR aims to mature promising tools for use on future missions and document the level of effort - and hence cost - required to implement an application with each selected tool. One of the FDIR capabilities is anomaly detection, i.e., detecting off-nominal behavior. The tool we selected for this task uses a data-driven approach. Unlike rule-based and model-based systems that require manual extraction of system knowledge, data-driven systems take a radically different approach to reasoning. At the basic level, they start with data that represent nominal functioning of the system and automatically learn expected system behavior. The behavior is encoded in a knowledge base that represents "in-family" system operations. During real-time system monitoring or during post-flight analysis, incoming data is compared to that nominal system operating behavior knowledge base; a distance representing deviation from nominal is computed, providing a measure of how far "out of family" current behavior is. We describe the selected tool for FDIR anomaly detection - Inductive Monitoring System (IMS), how it fits into the FDIR architecture, the operations concept for the GSE anomaly monitoring, and some preliminary results of applying IMS to a Space Shuttle GSE anomaly.

Active State Model for Autonomous Systems

NASA Technical Reports Server (NTRS)

Park, Han; Chien, Steve; Zak, Michail; James, Mark; Mackey, Ryan; Fisher, Forest

2003-01-01

The concept of the active state model (ASM) is an architecture for the development of advanced integrated fault-detection-and-isolation (FDI) systems for robotic land vehicles, pilotless aircraft, exploratory spacecraft, or other complex engineering systems that will be capable of autonomous operation. An FDI system based on the ASM concept would not only provide traditional diagnostic capabilities, but also integrate the FDI system under a unified framework and provide mechanism for sharing of information between FDI subsystems to fully assess the overall health of the system. The ASM concept begins with definitions borrowed from psychology, wherein a system is regarded as active when it possesses self-image, self-awareness, and an ability to make decisions itself, such that it is able to perform purposeful motions and other transitions with some degree of autonomy from the environment. For an engineering system, self-image would manifest itself as the ability to determine nominal values of sensor data by use of a mathematical model of itself, and selfawareness would manifest itself as the ability to relate sensor data to their nominal values. The ASM for such a system may start with the closed-loop control dynamics that describe the evolution of state variables. As soon as this model was supplemented with nominal values of sensor data, it would possess self-image. The ability to process the current sensor data and compare them with the nominal values would represent self-awareness. On the basis of self-image and self-awareness, the ASM provides the capability for self-identification, detection of abnormalities, and self-diagnosis.

White Collar Work: Career Ambitions of Fiji Final Year School Students

ERIC Educational Resources Information Center

Nilan, Pam; Cavu, Paula; Tagicakiverata, Isimeli; Hazelman, Emily

2006-01-01

The career ambitions of 1012 pupils in the final years of secondary schooling in Fiji were surveyed. The range of careers they nominated was very narrow, with teaching, nursing and other white collar work in the majority of responses. This stands in somewhat stark contrast to projected labour force needs, and the current serious shortage of…

Report on a Two-Year Farm Management/Agricultural Mechanics Curriculum Review

ERIC Educational Resources Information Center

Eighmy, Myron A.; Tews, Bradley D.

2006-01-01

The purpose of this project was to review the Farm Management curriculum at the North Dakota State College of Science (NDSCS) to determine if current curriculum content provides the knowledge and skills needed to be an entry-level farm manager in a contemporary farming operation. The nominal group technique was selected for this curriculum review.…

Contributions of Racial and Sociobehavioral Homophily to Friendship Stability and Quality among Same-Race and Cross-Race Friends

ERIC Educational Resources Information Center

McDonald, Kristina L.; Dashiell-Aje, Ebony; Menzer, Melissa M.; Rubin, Kenneth H.; Oh, Wonjung; Bowker, Julie C.

2013-01-01

The current study examined how racial and sociobehavioral similarities were associated with friendship stability and friendship quality. Cross-race friends were not significantly similar to each other in peer-nominated shyness/withdrawal, victimization, exclusion, and popularity/sociability. Relative to same-race friends, cross-race friends were…

Pronouns of Address in Western Ukrainian: Between Tradition and Modernity

ERIC Educational Resources Information Center

Weissenbock, Maria

2006-01-01

This article examines the current usage of terms of address in the Western Ukrainian variety of the Ukrainian language. It investigates the use of pronominal ("ty"--intimate form; ["Vy"--polite, distant form) and nominal forms of address (such as first name, father's name, surname, title, "pan/pani" (Mr/Mrs), "tovarys" (Comrade) etc.) in Western…

Globally optimal superconducting magnets part I: minimum stored energy (MSE) current density map.

PubMed

Tieng, Quang M; Vegh, Viktor; Brereton, Ian M

2009-01-01

An optimal current density map is crucial in magnet design to provide the initial values within search spaces in an optimization process for determining the final coil arrangement of the magnet. A strategy for obtaining globally optimal current density maps for the purpose of designing magnets with coaxial cylindrical coils in which the stored energy is minimized within a constrained domain is outlined. The current density maps obtained utilising the proposed method suggests that peak current densities occur around the perimeter of the magnet domain, where the adjacent peaks have alternating current directions for the most compact designs. As the dimensions of the domain are increased, the current density maps yield traditional magnet designs of positive current alone. These unique current density maps are obtained by minimizing the stored magnetic energy cost function and therefore suggest magnet coil designs of minimal system energy. Current density maps are provided for a number of different domain arrangements to illustrate the flexibility of the method and the quality of the achievable designs.

Two-dimensional relativistic space charge limited current flow in the drift space

NASA Astrophysics Data System (ADS)

Liu, Y. L.; Chen, S. H.; Koh, W. S.; Ang, L. K.

2014-04-01

Relativistic two-dimensional (2D) electrostatic (ES) formulations have been derived for studying the steady-state space charge limited (SCL) current flow of a finite width W in a drift space with a gap distance D. The theoretical analyses show that the 2D SCL current density in terms of the 1D SCL current density monotonically increases with D/W, and the theory recovers the 1D classical Child-Langmuir law in the drift space under the approximation of uniform charge density in the transverse direction. A 2D static model has also been constructed to study the dynamical behaviors of the current flow with current density exceeding the SCL current density, and the static theory for evaluating the transmitted current fraction and minimum potential position have been verified by using 2D ES particle-in-cell simulation. The results show the 2D SCL current density is mainly determined by the geometrical effects, but the dynamical behaviors of the current flow are mainly determined by the relativistic effect at the current density exceeding the SCL current density.

44 CFR 150.3 - Nomination process.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Section 150.3 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF... Nomination process. (a) The Nominating Officials nominating Firefighters and Civil Defense Officers shall...) Civil defense officer (or member of a recognized civil defense or emergency preparedness organization...

44 CFR 150.3 - Nomination process.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Section 150.3 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF... Nomination process. (a) The Nominating Officials nominating Firefighters and Civil Defense Officers shall...) Civil defense officer (or member of a recognized civil defense or emergency preparedness organization...

44 CFR 150.3 - Nomination process.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Section 150.3 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF... Nomination process. (a) The Nominating Officials nominating Firefighters and Civil Defense Officers shall...) Civil defense officer (or member of a recognized civil defense or emergency preparedness organization...

44 CFR 150.3 - Nomination process.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Section 150.3 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF... Nomination process. (a) The Nominating Officials nominating Firefighters and Civil Defense Officers shall...) Civil defense officer (or member of a recognized civil defense or emergency preparedness organization...

44 CFR 150.3 - Nomination process.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Section 150.3 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF... Nomination process. (a) The Nominating Officials nominating Firefighters and Civil Defense Officers shall...) Civil defense officer (or member of a recognized civil defense or emergency preparedness organization...

77 FR 19056 - Information Reporting Program Advisory Committee (IRPAC); Nominations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-29

... DEPARTMENT OF TREASURY Internal Revenue Service Information Reporting Program Advisory Committee (IRPAC); Nominations AGENCY: Internal Revenue Service, Department of Treasury. ACTION: Request for Nominations. SUMMARY: The Internal Revenue Service (IRS) requests nominations of individuals for selection to...

78 FR 19582 - Information Reporting Program Advisory Committee (IRPAC); Nominations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-01

... DEPARTMENT OF TREASURY Internal Revenue Service Information Reporting Program Advisory Committee (IRPAC); Nominations AGENCY: Internal Revenue Service, Department of Treasury. ACTION: Request for Nominations. SUMMARY: The Internal Revenue Service (IRS) requests nominations of individuals for selection to...

Bench-top Comparison of Physical Properties of 4 Commercially-Available Self-Expanding Intracranial Stents

PubMed Central

Cho, Su-hee; Jo, Won-il; Jo, Ye-eun; Yang, Ku Hyun; Park, Jung Cheol

2017-01-01

Purpose To better understand the performance of four commercially available neurovascular stents in intracranial aneurysm embolization, the stents were compared in terms of their basic morphological and mechanical properties. Materials and Methods Four different types of stents that are currently being used for cerebral aneurysm embolization were prepared (two stents per type). Two were laser-cut stents (Neuroform and Enterprise) and two were braided from a single nitinol wire (LEO and LVIS stents). All were subjected to quantitative measurements of stent size, pore density, metal coverage, the force needed to load, push, and deploy the stent, radial force on deployment, surface roughness, and corrosion resistance. Results Compared to their nominal diameters, all stents had greater diameters after deployment. The length generally decreased after deployment. This was particularly marked in the braided stents. The braided stents also had higher pore densities than the laser-cut stents. Metal coverage was highest in the LEO stent (14%) and lowest in the Enterprise stent (5%). The LIVS stent had the highest microcatheter loading force (81.5 gf). The LEO stent had the highest passage force (55.0 gf) and deployment force (78.9 gf). The LVIS and LEO stents had the highest perpendicular (37.1 gf) and circumferential (178.4 gf) radial forces, respectively. The Enterprise stent had the roughest stent wire, followed by the LVIS, LEO, and Neuroform stents. Conclusion The four neurovascular stent types differed in terms of morphological and physical characteristics. An understanding of this diversity may help to decide which stent is most suitable for specific clinical situations. PMID:28316867

Current density tensors

NASA Astrophysics Data System (ADS)

Lazzeretti, Paolo

2018-04-01

It is shown that nonsymmetric second-rank current density tensors, related to the current densities induced by magnetic fields and nuclear magnetic dipole moments, are fundamental properties of a molecule. Together with magnetizability, nuclear magnetic shielding, and nuclear spin-spin coupling, they completely characterize its response to magnetic perturbations. Gauge invariance, resolution into isotropic, deviatoric, and antisymmetric parts, and contributions of current density tensors to magnetic properties are discussed. The components of the second-rank tensor properties are rationalized via relationships explicitly connecting them to the direction of the induced current density vectors and to the components of the current density tensors. The contribution of the deviatoric part to the average value of magnetizability, nuclear shielding, and nuclear spin-spin coupling, uniquely determined by the antisymmetric part of current density tensors, vanishes identically. The physical meaning of isotropic and anisotropic invariants of current density tensors has been investigated, and the connection between anisotropy magnitude and electron delocalization has been discussed.

Development of rotating magnetic field coil system in the HIST spherical torus device

NASA Astrophysics Data System (ADS)

Yoshikawa, T.; Kikuchi, Y.; Yamada, S.; Hashimoto, S.; Nishioka, T.; Fukumoto, N.; Nagata, M.

2007-11-01

Coaxial Helicity Injection (CHI) is one of most attractive methods to achieve non-inductive current drive in spherical torus devices. The current drive mechanism of CHI relies on MHD relaxation process of rotating kink behavior [1], so that there is a possibility to control the CHI by using an externally applied rotating magnetic field (RMF). We have recently started to develop a RMF coil system in the HIST spherical torus device. Eight coils are located above and below the midplane at four toroidal locations so that the RMF is resonant with n = 1 rotating kink mode driven by the CHI. In addition, the RMF coil set is installed inside a flux conserver of 5 mm thickness (cut-off frequency ˜ 170 Hz) so that the RMF penetrates into the plasma. The coil winding is made of 20 turns of enameled copper circular wires (1.5 mm^2 conductor cross section), covered with a thin stainless steal case of 0.5 mm thickness (cut-off frequency ˜ 710 kHz). The RMF system is driven by an IGBT inverter power supply (nominal current: 1 kA, nominal voltage: 1 kV) with an operating frequency band from 10 kHz to 30 kHz. The estimated amplitude of RMF neglecting effects of image current at the flux conserver is a few tens Gauss at around the magnetic axis. A preliminary experimental result will be shown in the conference. [1] M. Nagata, et al., Physics of Plasmas 10, 2932 (2003).

Space Weather Influence on Relative Motion Control using the Touchless Electrostatic Tractor

NASA Astrophysics Data System (ADS)

Hogan, Erik A.; Schaub, Hanspeter

2016-09-01

With recent interest in the use of electrostatic forces for contactless tugging and attitude control of noncooperative objects for orbital servicing and active debris mitigation, the need for a method of remote charge control arises. In this paper, the use of a directed electron beam for remote charge control is considered in conjunction with the relative motion control. A tug vehicle emits an electron beam onto a deputy object, charging it negatively. At the same time, the tug is charged positively due to beam emission, resulting in an attractive electrostatic force. The relative position feedback control between the tug and the passive debris object is studied subject to the charging being created through an electron beam. Employing the nominal variations of the GEO space weather conditions across longitude slots, two electrostatic tugging strategies are considered. First, the electron beam current is adjusted throughout the orbit in order to maximize this resulting electrostatic force. This open-loop control strategy compensates for changes in the nominally expected local space weather environment in the GEO region to adjust for fluctuations in the local plasma return currents. Second, the performance impact of using a fixed electron beam current on the electrostatic tractor is studied if the same natural space weather variations are assumed. The fixed electron beam current shows a minor performance penalty (<5 %) while providing a much simpler implementation that does not require any knowledge of local space weather conditions.

The IRAS radiation environment

NASA Technical Reports Server (NTRS)

Stassinopoulos, E. G.

1978-01-01

Orbital flux integration for three selected mission altitudes and geographic instantaneous flux-mapping for nominal flight-path altitude were used to determine the external charged particle radiation predicted for the Infrared Astronomy Satellite. A current field model was used for magnetic field definitions for three nominal circular trajectories and for the geographic mapping positions. Innovative analysis features introduced include (1) positional fluxes as a function of time and energy for the most severe pass through the South Atlantic Anomaly; (2) total positional doses as a function of time and shield thickness; (3) comparison mapping fluxes for ratios of positional intensities to orbit integrated averages; and (4) statistical exposure-time history of a trajectory as a function of energy indicating, in percent of total mission duration, the time intervals over which the instantaneous fluxes would exceed the orbit integrated averages. Results are presented in tables and graphs.

Statistical Significance and Baseline Monitoring.

DTIC Science & Technology

1984-07-01

impacted at once........................... 24 6 Observed versus nominal a levels for multivariate tests of data sets (50 runs of 4 groups each...cumulative proportion of the observations found for each nominal level. The results of the comparisons of the observed versus nominal a levels for the...a values are always higher than nominal levels. Virtual- . .,ly all nominal a levels are below 0.20. In other words, the discriminant analysis models

Numerical investigation of split flows by gravity currents into two-layered stratified water bodies

NASA Astrophysics Data System (ADS)

Cortés, A.; Wells, M. G.; Fringer, O. B.; Arthur, R. S.; Rueda, F. J.

2015-07-01

The behavior of a two-dimensional (2-D) gravity current impinging upon a density step in a two-layered stratified basin is analyzed using a high-resolution Reynolds-Averaged Navier-Stokes model. The gravity current splits at the density step, and the portion of the buoyancy flux becoming an interflow is largely controlled by the vertical distribution of velocity and density within the gravity current and the magnitude of the density step between the two ambient layers. This is in agreement with recent laboratory observations. The strongest changes in the ambient density profiles occur as a result of the impingement of supercritical currents with strong density contrasts, for which a large portion of the gravity current detaches from the bottom and becomes an interflow. We characterize the current partition process in the simulated experiments using the densimetric Froude number of the current (Fr) across the density step (upstream and downstream). When underflows are formed, more supercritical currents are observed downstream of the density step compared to upstream (Fru < Frd), and thus, stronger mixing of the current with the ambient water downstream. However, when split flows and interflows are formed, smaller Fr values are identified after the current crosses the density step (Fru > Frd), which indicates lower mixing between the current and ambient water after the impingement due to the significant stripping of interfacial material at the density step.

THEMIS two‐point measurements of the cross‐tail current density: A thick bifurcated current sheet in the near‐Earth plasma sheet

PubMed Central

2015-01-01

Abstract The basic properties of the near‐Earth current sheet from 8 RE to 12 RE were determined based on Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations from 2007 to 2013. Ampere's law was used to estimate the current density when the locations of two spacecraft were suitable for the calculation. A total of 3838 current density observations were obtained to study the vertical profile. For typical solar wind conditions, the current density near (off) the central plane of the current sheet ranged from 1 to 2 nA/m2 (1 to 8 nA/m2). All the high current densities appeared off the central plane of the current sheet, indicating the formation of a bifurcated current sheet structure when the current density increased above 2 nA/m2. The median profile also showed a bifurcated structure, in which the half thickness was about 3 RE. The distance between the peak of the current density and the central plane of the current sheet was 0.5 to 1 RE. High current densities above 4 nA/m2 were observed in some cases that occurred preferentially during substorms, but they also occurred in quiet times. In contrast to the commonly accepted picture, these high current densities can form without a high solar wind dynamic pressure. In addition, these high current densities can appear in two magnetic configurations: tail‐like and dipolar structures. At least two mechanisms, magnetic flux depletion and new current system formation during the expansion phase, other than plasma sheet compression are responsible for the formation of the bifurcated current sheets. PMID:27722039

Building Consensus: Development of Best Practice Guidelines on Wrong Level Surgery in Spinal Deformity.

PubMed

Vitale, Michael; Minkara, Anas; Matsumoto, Hiroko; Albert, Todd; Anderson, Richard; Angevine, Peter; Buckland, Aaron; Cho, Samuel; Cunningham, Matthew; Errico, Thomas; Fischer, Charla; Kim, Han Jo; Lehman, Ronald; Lonner, Baron; Passias, Peter; Protopsaltis, Themistocles; Schwab, Frank; Lenke, Lawrence

Consensus-building using the Delphi and nominal group technique. To establish best practice guidelines using formal techniques of consensus building among a group of experienced spinal deformity surgeons to avert wrong-level spinal deformity surgery. Numerous previous studies have demonstrated that wrong-level spinal deformity occurs at a substantial rate, with more than half of all spine surgeons reporting direct or indirect experience operating on the wrong levels. Nevertheless, currently, guidelines to avert wrong-level spinal deformity surgery have not been developed. The Delphi process and nominal group technique were used to formally derive consensus among 16 fellowship-trained spine surgeons. Surgeons were surveyed for current practices, presented with the results of a systematic review, and asked to vote anonymously for or against item inclusion during three iterative rounds. Agreement of 80% or higher was considered consensus. Items near consensus (70% to 80% agreement) were probed in detail using the nominal group technique in a facilitated group meeting. Participants had a mean of 13.4 years of practice (range: 2-32 years) and 103.1 (range: 50-250) annual spinal deformity surgeries, with a combined total of 24,200 procedures. Consensus was reached for the creation of best practice guidelines (BPGs) consisting of 17 interventions to avert wrong-level surgery. A final checklist consisting of preoperative and intraoperative methods, including standardized vertebral-level counting and optimal imaging criteria, was supported by 100% of participants. We developed consensus-based best practice guidelines for the prevention of wrong-vertebral-level surgery. This can serve as a tool to reduce the variability in preoperative and intraoperative practices and guide research regarding the effectiveness of such interventions on the incidence of wrong-level surgery. Level V. Copyright © 2017 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

New Low Temperature Processing for Boron Carbide/Aluminum Based Composite Armor

DTIC Science & Technology

1990-06-01

cases. The aluminum powder was finer than 325 mesh (nominal 4 ptm diameter). The titanium diboride powder also had a median particle diameter of 4 g ~m...Al Before Heat Treatment. Sample Density Hardness Flex ( g /mL) (Rockwell A) Strength 70/30 B4 C/Al/dry 2.62±.03 81±3 57±5 ksi 70/30 B4 C/AI/wet/A 2.57...0.4 w/o nitrogen, 160 ppm calcium, 140 ppm chromium. 270 ppm iron, and 330 ppm nickel. The surface area was 7 m 2 / g . Initial dispersion and filter

76 FR 52016 - NASA Federal Advisory Committees; Nominations and Self-Nominations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-19

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice: (11- 075)] NASA Federal Advisory Committees; Nominations and Self- Nominations AGENCY: National Aeronautics and Space Administration. ACTION: Public... the Federal Advisory Committee Act, Public Law 92-463, as amended, the National Aeronautics and Space...

7 CFR 987.124 - Nomination and polling.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Nomination and polling. 987.124 Section 987.124 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... IN RIVERSIDE COUNTY, CALIFORNIA Administrative Rules Nominations § 987.124 Nomination and polling. (a...

7 CFR 1150.133 - Nominations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 9 2012-01-01 2012-01-01 false Nominations. 1150.133 Section 1150.133 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Order National Dairy Promotion and Research Board § 1150.133 Nominations. Nominations for members of the...

7 CFR 1150.133 - Nominations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 9 2013-01-01 2013-01-01 false Nominations. 1150.133 Section 1150.133 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Order National Dairy Promotion and Research Board § 1150.133 Nominations. Nominations for members of the...

NekNominate: Social Norms, Social Media, and Binge Drinking.

PubMed

Wombacher, Kevin; Reno, Jenna E; Veil, Shari R

2017-05-01

This study examines the social-media-based binge drinking game NekNominate and how this phenomenon is related to social norms. NekNominate is a game wherein players are nominated to film themselves "neking" or chugging copious amounts of alcohol or drinking alcohol in a novel or humorous manner. The player then nominates other players via social media who then have a specific timeframe in which they must complete their challenge or face ridicule. Health communication research on drinking behaviors has often looked at the role of social norms in determining these behaviors. News stories (n = 44) of NekNominate and tweets (n = 851) culled using the hashtag #NekNominate during three different time periods are analyzed to identify the normative forces at play in this recent phenomenon.

Adaptive Variable Bias Magnetic Bearing Control

NASA Technical Reports Server (NTRS)

Johnson, Dexter; Brown, Gerald V.; Inman, Daniel J.

1998-01-01

Most magnetic bearing control schemes use a bias current with a superimposed control current to linearize the relationship between the control current and the force it delivers. With the existence of the bias current, even in no load conditions, there is always some power consumption. In aerospace applications, power consumption becomes an important concern. In response to this concern, an alternative magnetic bearing control method, called Adaptive Variable Bias Control (AVBC), has been developed and its performance examined. The AVBC operates primarily as a proportional-derivative controller with a relatively slow, bias current dependent, time-varying gain. The AVBC is shown to reduce electrical power loss, be nominally stable, and provide control performance similar to conventional bias control. Analytical, computer simulation, and experimental results are presented in this paper.

45 CFR 1801.18 - Limitations on nominations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 4 2014-10-01 2014-10-01 false Limitations on nominations. 1801.18 Section 1801.18 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.18 Limitations on nominations. A candidate...

45 CFR 1801.18 - Limitations on nominations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Limitations on nominations. 1801.18 Section 1801.18 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.18 Limitations on nominations. A candidate...

45 CFR 1801.18 - Limitations on nominations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Limitations on nominations. 1801.18 Section 1801.18 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.18 Limitations on nominations. A candidate...

45 CFR 1801.18 - Limitations on nominations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 4 2012-10-01 2012-10-01 false Limitations on nominations. 1801.18 Section 1801.18 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.18 Limitations on nominations. A candidate...

45 CFR 1801.18 - Limitations on nominations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 4 2013-10-01 2013-10-01 false Limitations on nominations. 1801.18 Section 1801.18 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.18 Limitations on nominations. A candidate...

7 CFR 1220.203 - Nominations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... CONSUMER INFORMATION Soybean Promotion and Research Order United Soybean Board § 1220.203 Nominations. All... be filled. (e) Nominations may be submitted in order of preference and for the initial Board, in order of preference for staggered terms. Should the Secretary reject any nomination submitted and there...

7 CFR 932.31 - Failure to nominate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Failure to nominate. 932.31 Section 932.31 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Olive Administrative Committee § 932.31 Failure to nominate. If nominations for any...

7 CFR 953.20 - Failure to nominate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Failure to nominate. 953.20 Section 953.20 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... STATES Order Regulating Handling Administrative Committee § 953.20 Failure to nominate. If nominations...

7 CFR 953.20 - Failure to nominate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Failure to nominate. 953.20 Section 953.20 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... STATES Order Regulating Handling Administrative Committee § 953.20 Failure to nominate. If nominations...

7 CFR 932.31 - Failure to nominate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Failure to nominate. 932.31 Section 932.31 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Regulating Handling Olive Administrative Committee § 932.31 Failure to nominate. If nominations for any...

7 CFR 927.25 - Failure to nominate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Failure to nominate. 927.25 Section 927.25 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Order Regulating Handling Administrative Bodies § 927.25 Failure to nominate. In the event nominations...

7 CFR 932.31 - Failure to nominate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Failure to nominate. 932.31 Section 932.31 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Olive Administrative Committee § 932.31 Failure to nominate. If nominations for any...

7 CFR 953.20 - Failure to nominate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Failure to nominate. 953.20 Section 953.20 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... STATES Order Regulating Handling Administrative Committee § 953.20 Failure to nominate. If nominations...

7 CFR 917.26 - Failure to nominate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Failure to nominate. 917.26 Section 917.26 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... CALIFORNIA Order Regulating Handling Administrative Bodies § 917.26 Failure to nominate. If nominations are...

7 CFR 927.25 - Failure to nominate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Failure to nominate. 927.25 Section 927.25 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Order Regulating Handling Administrative Bodies § 927.25 Failure to nominate. In the event nominations...

7 CFR 917.26 - Failure to nominate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Failure to nominate. 917.26 Section 917.26 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... CALIFORNIA Order Regulating Handling Administrative Bodies § 917.26 Failure to nominate. If nominations are...

7 CFR 927.25 - Failure to nominate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Failure to nominate. 927.25 Section 927.25 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Order Regulating Handling Administrative Bodies § 927.25 Failure to nominate. In the event nominations...

7 CFR 917.26 - Failure to nominate.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Failure to nominate. 917.26 Section 917.26 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... CALIFORNIA Order Regulating Handling Administrative Bodies § 917.26 Failure to nominate. If nominations are...

7 CFR 917.26 - Failure to nominate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Failure to nominate. 917.26 Section 917.26 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... CALIFORNIA Order Regulating Handling Administrative Bodies § 917.26 Failure to nominate. If nominations are...

7 CFR 932.31 - Failure to nominate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Failure to nominate. 932.31 Section 932.31 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Olive Administrative Committee § 932.31 Failure to nominate. If nominations for any...

7 CFR 917.26 - Failure to nominate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Failure to nominate. 917.26 Section 917.26 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... CALIFORNIA Order Regulating Handling Administrative Bodies § 917.26 Failure to nominate. If nominations are...

7 CFR 932.31 - Failure to nominate.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Failure to nominate. 932.31 Section 932.31 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Regulating Handling Olive Administrative Committee § 932.31 Failure to nominate. If nominations for any...

7 CFR 927.25 - Failure to nominate.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Failure to nominate. 927.25 Section 927.25 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Order Regulating Handling Administrative Bodies § 927.25 Failure to nominate. In the event nominations...

7 CFR 927.25 - Failure to nominate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Failure to nominate. 927.25 Section 927.25 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Order Regulating Handling Administrative Bodies § 927.25 Failure to nominate. In the event nominations...

Recent Updates to the MELCOR 1.8.2 Code for ITER Applications

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

Merrill, Brad J

This report documents recent changes made to the MELCOR 1.8.2 computer code for application to the International Thermonuclear Experimental Reactor (ITER), as required by ITER Task Agreement ITA 81-18. There are four areas of change documented by this report. The first area is the addition to this code of a model for transporting HTO. The second area is the updating of the material oxidation correlations to match those specified in the ITER Safety Analysis Data List (SADL). The third area replaces a modification to an aerosol tranpsort subroutine that specified the nominal aerosol density internally with one that now allowsmore » the user to specify this density through user input. The fourth area corrected an error that existed in an air condensation subroutine of previous versions of this modified MELCOR code. The appendices of this report contain FORTRAN listings of the coding for these modifications.« less

Inference of missing data and chemical model parameters using experimental statistics

NASA Astrophysics Data System (ADS)

Casey, Tiernan; Najm, Habib

2017-11-01

A method for determining the joint parameter density of Arrhenius rate expressions through the inference of missing experimental data is presented. This approach proposes noisy hypothetical data sets from target experiments and accepts those which agree with the reported statistics, in the form of nominal parameter values and their associated uncertainties. The data exploration procedure is formalized using Bayesian inference, employing maximum entropy and approximate Bayesian computation methods to arrive at a joint density on data and parameters. The method is demonstrated in the context of reactions in the H2-O2 system for predictive modeling of combustion systems of interest. Work supported by the US DOE BES CSGB. Sandia National Labs is a multimission lab managed and operated by Nat. Technology and Eng'g Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell Intl, for the US DOE NCSA under contract DE-NA-0003525.

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

Jamer, Michelle E.; Wang, Yung Jui; Stephen, Gregory M.

While antiferromagnets have been proposed as components to limit stray magnetic fields, their inability to be spin polarized inhibits their use in spintronic devices. Compensated ferrimagnets are a unique solution to this dilemma since they have zero net moment, but their nonsymmetric density of states allows the achievement of high spin polarization. Density-functional theory predicts Mn3Al in the D0(3) structure to be fully compensated and retain half-metallicity at room temperature. In this work, 50-nm Mn3Al thin films are synthesized using molecular beam epitaxy and annealed at various temperatures in order to investigate their magnetic properties. Magnetometry measurements confirm the highmore » Curie temperature of 605 K. Polarized-neutron reflectometry (PNR) indicates a low net magnetic moment, along with depth profiles of the structure and magnetization. From the PNR data, a saturation moment of 0.11 +/- 0.04 mu B/f.u. is extracted, confirming the nominal zero moment present in these thin films.« less

Atmospheric Modeling Using Accelerometer Data During Mars Atmosphere and Volatile Evolution (MAVEN) Flight Operations

NASA Technical Reports Server (NTRS)

Tolson, Robert H.; Lugo, Rafael A.; Baird, Darren T.; Cianciolo, Alicia D.; Bougher, Stephen W.; Zurek, Richard M.

2017-01-01

The Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft is a NASA orbiter designed to explore the Mars upper atmosphere, typically from 140 to 160 km altitude. In addition to the nominal science mission, MAVEN has performed several Deep Dip campaigns in which the orbit's closest point of approach, also called periapsis, was lowered to an altitude range of 115 to 135 km. MAVEN accelerometer data were used during mission operations to estimate atmospheric parameters such as density, scale height, along-track gradients, and wave structures. Density and scale height estimates were compared against those obtained from the Mars Global Reference Atmospheric Model and used to aid the MAVEN navigation team in planning maneuvers to raise and lower periapsis during Deep Dip operations. This paper describes the processes used to reconstruct atmosphere parameters from accelerometers data and presents the results of their comparison to model and navigation-derived values.

Magneto-acousto-electrical tomography: a potential method for imaging current density and electrical impedance.

PubMed

Haider, S; Hrbek, A; Xu, Y

2008-06-01

Primarily this report outlines our investigation on utilizing magneto-acousto-electrical-tomography (MAET) to image the lead field current density in volume conductors. A lead field current density distribution is obtained when a current/voltage source is applied to a sample via a pair of electrodes. This is the first time a high-spatial-resolution image of current density is presented using MAET. We also compare an experimental image of current density in a sample with its corresponding numerical simulation. To image the lead field current density, rather than applying a current/voltage source directly to the sample, we place the sample in a static magnetic field and focus an ultrasonic pulse on the sample to simulate a point-like current dipole source at the focal point. Then by using electrodes we measure the voltage/current signal which, based on the reciprocity theorem, is proportional to a component of the lead field current density. In the theory section, we derive the equation relating the measured voltage to the lead field current density and the displacement velocity caused by ultrasound. The experimental data include the MAET signal and an image of the lead field current density for a thin sample. In addition, we discuss the potential improvements for MAET especially to overcome the limitation created by the observation that no signal was detected from the interior of a region having a uniform conductivity. As an auxiliary we offer a mathematical formula whereby the lead field current density may be utilized to reconstruct the distribution of the electrical impedance in a piecewise smooth object.

High current density cathode for electrorefining in molten electrolyte

DOEpatents

Li, Shelly X.

2010-06-29

A high current density cathode for electrorefining in a molten electrolyte for the continuous production and collection of loose dendritic or powdery deposits. The high current density cathode eliminates the requirement for mechanical scraping and electrochemical stripping of the deposits from the cathode in an anode/cathode module. The high current density cathode comprises a perforated electrical insulated material coating such that the current density is up to 3 A/cm.sup.2.

75 FR 44793 - Consumer Advisory Council Solicitation of Nominations for Membership

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-29

... to nominate qualified individuals for appointment to its Consumer Advisory Council, whose membership... affiliation, title, address, phone and fax numbers, and e-mail address. Individuals may nominate themselves... does not limit consideration to individuals nominated by the public when making its selection. Council...

36 CFR 60.11 - Requests for nominations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... and appears to meet the National Register criteria for evaluation in § 60.4. If the nomination form is... any person or organization submitting a completed National Register nomination form or requesting consideration for any previously prepared nomination form on record with the State or Federal agency. The...

7 CFR 1219.34 - Failure to nominate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 10 2012-01-01 2012-01-01 false Failure to nominate. 1219.34 Section 1219.34 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING....34 Failure to nominate. In any case in which producers or importers fail to nominate individuals for...

7 CFR 915.24 - Failure to nominate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Failure to nominate. 915.24 Section 915.24 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Regulating Handling Administrative Body § 915.24 Failure to nominate. If nominations are not made within the...

7 CFR 915.24 - Failure to nominate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Failure to nominate. 915.24 Section 915.24 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Administrative Body § 915.24 Failure to nominate. If nominations are not made within the...

7 CFR 1219.34 - Failure to nominate.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 10 2013-01-01 2013-01-01 false Failure to nominate. 1219.34 Section 1219.34 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING....34 Failure to nominate. In any case in which producers or importers fail to nominate individuals for...

7 CFR 915.24 - Failure to nominate.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Failure to nominate. 915.24 Section 915.24 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Regulating Handling Administrative Body § 915.24 Failure to nominate. If nominations are not made within the...

7 CFR 948.57 - Failure to nominate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Failure to nominate. 948.57 Section 948.57 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Order Regulating Handling Committees § 948.57 Failure to nominate. If nominations are not made pursuant...

7 CFR 948.57 - Failure to nominate.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Failure to nominate. 948.57 Section 948.57 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Order Regulating Handling Committees § 948.57 Failure to nominate. If nominations are not made pursuant...

7 CFR 948.57 - Failure to nominate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Failure to nominate. 948.57 Section 948.57 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Order Regulating Handling Committees § 948.57 Failure to nominate. If nominations are not made pursuant...

7 CFR 1219.34 - Failure to nominate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 10 2011-01-01 2011-01-01 false Failure to nominate. 1219.34 Section 1219.34 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING....34 Failure to nominate. In any case in which producers or importers fail to nominate individuals for...

7 CFR 916.24 - Failure to nominate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Failure to nominate. 916.24 Section 916.24 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Administrative Body § 916.24 Failure to nominate. If nominations are not made within the...

7 CFR 916.24 - Failure to nominate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Failure to nominate. 916.24 Section 916.24 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Administrative Body § 916.24 Failure to nominate. If nominations are not made within the...

7 CFR 948.57 - Failure to nominate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Failure to nominate. 948.57 Section 948.57 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Order Regulating Handling Committees § 948.57 Failure to nominate. If nominations are not made pursuant...

7 CFR 948.57 - Failure to nominate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Failure to nominate. 948.57 Section 948.57 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Order Regulating Handling Committees § 948.57 Failure to nominate. If nominations are not made pursuant...

7 CFR 1219.34 - Failure to nominate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 10 2014-01-01 2014-01-01 false Failure to nominate. 1219.34 Section 1219.34 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING....34 Failure to nominate. In any case in which producers or importers fail to nominate individuals for...

7 CFR 915.24 - Failure to nominate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Failure to nominate. 915.24 Section 915.24 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Administrative Body § 915.24 Failure to nominate. If nominations are not made within the...

Distribution of E/N and N/e/ in a cross-flow electric discharge laser. [electric field to neutral gas density and electron number density

NASA Technical Reports Server (NTRS)

Dunning, J. W., Jr.; Lancashire, R. B.; Manista, E. J.

1976-01-01

Measurements have been conducted of the effect of the convection of ions and electrons on the discharge characteristics in a large scale laser. The results are presented for one particular distribution of ballast resistance. Values of electric field, current density, input power density, ratio of electric field to neutral gas density (E/N), and electron number density were calculated on the basis of measurements of the discharge properties. In a number of graphs, the E/N ratio, current density, power density, and electron density are plotted as a function of row number (downstream position) with total discharge current and gas velocity as parameters. From the dependence of the current distribution on the total current, it appears that the electron production in the first two rows significantly affects the current flowing in the succeeding rows.

Analysis of recoverable current from one component of magnetic flux density in MREIT and MRCDI.

PubMed

Park, Chunjae; Lee, Byung Il; Kwon, Oh In

2007-06-07

Magnetic resonance current density imaging (MRCDI) provides a current density image by measuring the induced magnetic flux density within the subject with a magnetic resonance imaging (MRI) scanner. Magnetic resonance electrical impedance tomography (MREIT) has been focused on extracting some useful information of the current density and conductivity distribution in the subject Omega using measured B(z), one component of the magnetic flux density B. In this paper, we analyze the map Tau from current density vector field J to one component of magnetic flux density B(z) without any assumption on the conductivity. The map Tau provides an orthogonal decomposition J = J(P) + J(N) of the current J where J(N) belongs to the null space of the map Tau. We explicitly describe the projected current density J(P) from measured B(z). Based on the decomposition, we prove that B(z) data due to one injection current guarantee a unique determination of the isotropic conductivity under assumptions that the current is two-dimensional and the conductivity value on the surface is known. For a two-dimensional dominating current case, the projected current density J(P) provides a good approximation of the true current J without accumulating noise effects. Numerical simulations show that J(P) from measured B(z) is quite similar to the target J. Biological tissue phantom experiments compare J(P) with the reconstructed J via the reconstructed isotropic conductivity using the harmonic B(z) algorithm.

Use of a Teacher Nomination Strategy to Screen for Autism Spectrum Disorders in General Education Classrooms: A Pilot Study

PubMed Central

Hepburn, Susan L.; DiGuiseppi, Carolyn; Rosenberg, Steven; Kaparich, Kristina; Robinson, Cordelia; Miller, Lisa

2015-01-01

Given a rising prevalence of autism spectrum disorders (ASD), this project aimed to develop and pilot test various teacher nomination strategies to identify children at risk for ASD in a timely, reliable, cost-effective manner. Sixty participating elementary school teachers evaluated 1323 children in total. Each teacher nominated students who most fit a description of ASD-associated characteristics, and completed the Autism Syndrome Screening Questionnaire (ASSQ) on every child in the classroom. The proportion of overall agreement between teacher nomination and ASSQ was 93–95%, depending upon the nomination parameters. Nomination required 15 min per class versus 3.5–5.5 h per class for the ASSQ. These results support the need for further study of teacher nomination strategies to identify children at risk for ASD. PMID:17661165

Meteoroid Environment Modeling: the Meteoroid Engineering Model and Shower Forecasting

NASA Technical Reports Server (NTRS)

Moorhead, Althea V.

2017-01-01

The meteoroid environment is often divided conceptually into meteor showers plus a sporadic background component. The sporadic complex poses the bulk of the risk to spacecraft, but showers can produce significant short-term enhancements of the meteoroid flux. The Meteoroid Environment Office (MEO) has produced two environment models to handle these cases: the Meteoroid Engineering Model (MEM) and an annual meteor shower forecast. Both MEM and the forecast are used by multiple manned spaceflight projects in their meteoroid risk evaluation, and both tools are being revised to incorporate recent meteor velocity, density, and timing measurements. MEM describes the sporadic meteoroid complex and calculates the flux, speed, and directionality of the meteoroid environment relative to a user-supplied spacecraft trajectory, taking the spacecraft's motion into account. MEM is valid in the inner solar system and offers near-Earth and cis-lunar environments. While the current version of MEM offers a nominal meteoroid environment corresponding to a single meteoroid bulk density, the next version of MEMR3 will offer both flux uncertainties and a density distribution in addition to a revised near-Earth environment. We have updated the near-Earth meteor speed distribution and have made the first determination of uncertainty in this distribution. We have also derived a meteor density distribution from the work of Kikwaya et al. (2011). The annual meteor shower forecast takes the form of a report and data tables that can be used in conjunction with an existing MEM assessment. Fluxes are typically quoted to a constant limiting kinetic energy in order to comport with commonly used ballistic limit equations. For the 2017 annual forecast, the MEO substantially revised the list of showers and their characteristics using 14 years of meteor flux measurements from the Canadian Meteor Orbit Radar (CMOR). Defunct or insignificant showers were removed and the temporal profiles of many showers were improved. In 2016 the MEO also adapted the forecast to the cislunar environment for the first time. We plan to make additional improvements to the model in the next two years using optical meteor flux measurements and mass indices.

In vivo mapping of current density distribution in brain tissues during deep brain stimulation (DBS)

NASA Astrophysics Data System (ADS)

Sajib, Saurav Z. K.; Oh, Tong In; Kim, Hyung Joong; Kwon, Oh In; Woo, Eung Je

2017-01-01

New methods for in vivo mapping of brain responses during deep brain stimulation (DBS) are indispensable to secure clinical applications. Assessment of current density distribution, induced by internally injected currents, may provide an alternative method for understanding the therapeutic effects of electrical stimulation. The current flow and pathway are affected by internal conductivity, and can be imaged using magnetic resonance-based conductivity imaging methods. Magnetic resonance electrical impedance tomography (MREIT) is an imaging method that can enable highly resolved mapping of electromagnetic tissue properties such as current density and conductivity of living tissues. In the current study, we experimentally imaged current density distribution of in vivo canine brains by applying MREIT to electrical stimulation. The current density maps of three canine brains were calculated from the measured magnetic flux density data. The absolute current density values of brain tissues, including gray matter, white matter, and cerebrospinal fluid were compared to assess the active regions during DBS. The resulting current density in different tissue types may provide useful information about current pathways and volume activation for adjusting surgical planning and understanding the therapeutic effects of DBS.

Current-voltage characteristics influenced by the nanochannel diameter and surface charge density in a fluidic field-effect-transistor.

PubMed

Singh, Kunwar Pal; Guo, Chunlei

2017-06-21

The nanochannel diameter and surface charge density have a significant impact on current-voltage characteristics in a nanofluidic transistor. We have simulated the effect of the channel diameter and surface charge density on current-voltage characteristics of a fluidic nanochannel with positive surface charge on its walls and a gate electrode on its surface. Anion depletion/enrichment leads to a decrease/increase in ion current with gate potential. The ion current tends to increase linearly with gate potential for narrow channels at high surface charge densities and narrow channels are more effective to control the ion current at high surface charge densities. The current-voltage characteristics are highly nonlinear for wide channels at low surface charge densities and they show different regions of current change with gate potential. The ion current decreases with gate potential after attaining a peak value for wide channels at low values of surface charge densities. At low surface charge densities, the ion current can be controlled by a narrow range of gate potentials for wide channels. The current change with source drain voltage shows ohmic, limiting and overlimiting regions.

Surface currents associated with external kink modes in tokamak plasmas during a major disruption

NASA Astrophysics Data System (ADS)

Ng, C. S.; Bhattacharjee, A.

2017-10-01

The surface current on the plasma-vacuum interface during a disruption event involving kink instability can play an important role in driving current into the vacuum vessel. However, there have been disagreements over the nature or even the sign of the surface current in recent theoretical calculations based on idealized step-function background plasma profiles. We revisit such calculations by replacing step-function profiles with more realistic profiles characterized by a strong but finite gradient along the radial direction. It is shown that the resulting surface current is no longer a delta-function current density, but a finite and smooth current density profile with an internal structure, concentrated within the region with a strong plasma pressure gradient. Moreover, this current density profile has peaks of both signs, unlike the delta-function case with a sign opposite to, or the same as the plasma current. We show analytically and numerically that such current density can be separated into two parts, with one of them, called the convective current density, describing the transport of the background plasma density by the displacement, and the other part that remains, called the residual current density. It is argued that consideration of both types of current density is important and can resolve past controversies.

Nominal group technique-elicited barriers and facilitators to following the Dietary Guidelines for solid fats and added sugars in children: The HEALTH Study

USDA-ARS?s Scientific Manuscript database

The US population has a high intake of discretionary solid fats and added sugars (SoFAS) which currently exceeds federal dietary recommendations. The goal of this study was to identify barriers and facilitators to following the DGA. Thirty-eight 5th grade children across six Human Nutrition Resear...

A Step toward Global Awareness: An Examination of USBBY Outstanding International Books for the Primary Grades

ERIC Educational Resources Information Center

Liang, Lauren Aimonette; Watkins, Naomi M.; Williams, Virginia S.

2013-01-01

This article describes results from an examination of common characteristics in the award-winning United States Board on Books for Young People (USBBY) Outstanding International Books for Grades K-2 from 2006 to 2012. Books nominated for the USBBY Outstanding International Books List must be currently available in the United States market. The…

33 CFR 183.435 - Conductors in circuits of 50 volts or more.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Conductors in circuits of 50... Requirements § 183.435 Conductors in circuits of 50 volts or more. (a) Each conductor in a circuit that has a... nominal circuit voltage of each of three or more current carrying conductors in a duct, bundle, or cable...

33 CFR 183.435 - Conductors in circuits of 50 volts or more.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Conductors in circuits of 50... Requirements § 183.435 Conductors in circuits of 50 volts or more. (a) Each conductor in a circuit that has a... nominal circuit voltage of each of three or more current carrying conductors in a duct, bundle, or cable...

33 CFR 183.435 - Conductors in circuits of 50 volts or more.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Conductors in circuits of 50... Requirements § 183.435 Conductors in circuits of 50 volts or more. (a) Each conductor in a circuit that has a... nominal circuit voltage of each of three or more current carrying conductors in a duct, bundle, or cable...

33 CFR 183.435 - Conductors in circuits of 50 volts or more.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Conductors in circuits of 50... Requirements § 183.435 Conductors in circuits of 50 volts or more. (a) Each conductor in a circuit that has a... nominal circuit voltage of each of three or more current carrying conductors in a duct, bundle, or cable...

33 CFR 183.435 - Conductors in circuits of 50 volts or more.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Conductors in circuits of 50... Requirements § 183.435 Conductors in circuits of 50 volts or more. (a) Each conductor in a circuit that has a... nominal circuit voltage of each of three or more current carrying conductors in a duct, bundle, or cable...

GLAS Spacecraft Pointing Study

NASA Technical Reports Server (NTRS)

Born, George H.; Gold, Kenn; Ondrey, Michael; Kubitschek, Dan; Axelrad, Penina; Komjathy, Attila

1998-01-01

Science requirements for the GLAS mission demand that the laser altimeter be pointed to within 50 m of the location of the previous repeat ground track. The satellite will be flown in a repeat orbit of 182 days. Operationally, the required pointing information will be determined on the ground using the nominal ground track, to which pointing is desired, and the current propagated orbit of the satellite as inputs to the roll computation algorithm developed by CCAR. The roll profile will be used to generate a set of fit coefficients which can be uploaded on a daily basis and used by the on-board attitude control system. In addition, an algorithm has been developed for computation of the associated command quaternions which will be necessary when pointing at targets of opportunity. It may be desirable in the future to perform the roll calculation in an autonomous real-time mode on-board the spacecraft. GPS can provide near real-time tracking of the satellite, and the nominal ground track can be stored in the on-board computer. It will be necessary to choose the spacing of this nominal ground track to meet storage requirements in the on-board environment. Several methods for generating the roll profile from a sparse reference ground track are presented.

Identifying future models for delivering genetic services: a nominal group study in primary care

PubMed Central

Elwyn, Glyn; Edwards, Adrian; Iredale, Rachel; Davies, Peter; Gray, Jonathon

2005-01-01

Background To enable primary care medical practitioners to generate a range of possible service delivery models for genetic counselling services and critically assess their suitability. Methods Modified nominal group technique using in primary care professional development workshops. Results 37 general practitioners in Wales, United Kingdom too part in the nominal group process. The practitioners who attended did not believe current systems were sufficient to meet anticipated demand for genetic services. A wide range of different service models was proposed, although no single option emerged as a clear preference. No argument was put forward for genetic assessment and counselling being central to family practice, neither was there a voice for the view that the family doctor should become skilled at advising patients about predictive genetic testing and be able to counsel patients about the wider implications of genetic testing for patients and their family members, even for areas such as common cancers. Nevertheless, all the preferred models put a high priority on providing the service in the community, and often co-located in primary care, by clinicians who had developed expertise. Conclusion There is a need for a wider debate about how healthcare systems address individual concerns about genetic concerns and risk, especially given the increasing commercial marketing of genetic tests. PMID:15831099

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

Fondeur, F.; Taylor-Pashow, K.

Savannah River National Laboratory (SRNL) received two sets of Solvent Hold Tank (SHT) samples (MCU-15-389 and MCU-15-390 pulled on February 23, 2015 and MCU-15-439, MCU-15-440, and MCU-15-441 pulled on February 28, 2015) for analysis. The samples in each set were combined and analyzed for composition. Analysis of the composite samples MCU-15-389-390 and MCU-15-439-440- 441 indicated a low concentration (~ 92 to 93 % of nominal) of the suppressor (TiDG) and slightly below nominal concentrations of the extractant (MaxCalix), but nominal levels of the modifier (CS-7SB) and of the Isopar™ L. This analysis confirms the addition of TiDG, MaxCalix, and modifiermore » to the solvent on February 22, 2015. Despite that the values are below the target component levels, the current levels of TiDG and MaxCalix are sufficient for continuing operation without adding a trim at this time. No impurities above the 1000 ppm level were found in this solvent. However, the p-nut vials that delivered the samples contained small (1 mm) droplets of oxidized modifier and amides. The laboratory will continue to monitor the quality of the solvent in particular for any new impurity or degradation of the solvent components.« less

Mechanical Energy Propagation and Backscattering in Nominally Dry Soil: Imaging Buried Land Mines

NASA Astrophysics Data System (ADS)

Sen, Surajit

2003-04-01

The imaging of shallow buried objects in a complex medium, e.g., nominally dry sand, is an outstanding challenge. Such imaging is of relevance in connection with the detection and subsequent imaging of buried non-metallic anti-personnel land mines and in other applications. It has been shown that gentle mechanical impulses and low frequency sound waves with frequencies roughly between 150-350 Hz or so can penetrate distances of up to a foot in sand. Hence, such signals can potentially be useful in the detection and perhaps in the imaging of shallow buried objects. It is presently unclear whether high frequency signals can be effectively used to image shallow buried objects. Impulses can typically penetrate larger distances into sand and soil. Both impulses and continuous sound waves can be used for imaging shallow buried objects. The talk shall briefly review the state-of-the-art in low frequency sound propagation in soil and shall discuss the current understanding of impulse propagation and backscattering in nominally dry sand beds. It will be argued that impulse based imaging may have the potential to be a simple and fast way to detect and image small non-metallic mines. Research supported by the National Science Foundation Grant No. NSF-CMS 0070055.

Off-Nominal Performance of the International Space Station Solar Array Wings Under Orbital Eclipse Lighting Scenarios

NASA Technical Reports Server (NTRS)

Kerslake, Thomas W.; Scheiman, David A.

2005-01-01

This paper documents testing and analyses to quantify International Space Station (ISS) Solar Array Wing (SAW) string electrical performance under highly off-nominal, low-temperature-low-intensity (LILT) operating conditions with nonsolar light sources. This work is relevant for assessing feasibility and risks associated with a Sequential Shunt Unit (SSU) remove and replace (R&R) Extravehicular Activity (EVA). During eclipse, SAW strings can be energized by moonlight, EVA suit helmet lights or video camera lights. To quantify SAW performance under these off-nominal conditions, solar cell performance testing was performed using full moon, solar simulator and Video Camera Luminaire (VCL) light sources. Test conditions included 25 to 110 C temperatures and 1- to 0.0001-Sun illumination intensities. Electrical performance data and calculated eclipse lighting intensities were combined to predict SAW current-voltage output for comparison with electrical hazard thresholds. Worst case predictions show there is no connector pin molten metal hazard but crew shock hazard limits are exceeded due to VCL illumination. Assessment uncertainties and limitations are discussed along with operational solutions to mitigate SAW electrical hazards from VCL illumination. Results from a preliminary assessment of SAW arcing are also discussed. The authors recommend further analyses once SSU, R&R, and EVA procedures are better defined.

Does an aggressor's target choice matter? Assessing change in the social network prestige of aggressive youth.

PubMed

Andrews, Naomi C Z; Hanish, Laura D; Santos, Carlos E

2017-07-01

Based on a social dominance approach, aggression is conceptualized as a strategy used to gain position, power, and influence within the peer network. However, aggression may only be beneficial when targeted against particular peers; both victims' social standing and the number of victims targeted may impact aggressors' social standing. The current study examined associations between aggressors' targeting tendencies (victims' social standing and number of victims) and aggressors' own social standing, both concurrently and over time. Analyses were conducted using three analytic samples of seventh and eighth grade aggressors (Ns ranged from 161 to 383, 49% girls; 50% Latina/o). Participants nominated their friends; nominations were used to calculate social network prestige. Peer nominations were used to identify aggressors and their victim(s). For each aggressor, number of victims and victims' social network prestige were assessed. Aggressors with more victims and with highly prestigious victims had higher social network prestige themselves, and they increased more in prestige over time than aggressors with fewer victims and less prestigious victims (though there were some differences across analytic samples). Findings have implications for the need to extend the social dominance approach to better address the links between aggressors and victims. Aggr. Behav. 43:364-374, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

24 CFR 598.205 - What are the requirements for nomination?

Code of Federal Regulations, 2013 CFR

2013-04-01

... nomination? 598.205 Section 598.205 Housing and Urban Development Regulations Relating to Housing and Urban... DESIGNATIONS Nomination Procedure § 598.205 What are the requirements for nomination? (a) General. No urban... that the strategic plan described in § 598.215 will be implemented, and these governments submit its...

24 CFR 598.205 - What are the requirements for nomination?

Code of Federal Regulations, 2012 CFR

2012-04-01

... nomination? 598.205 Section 598.205 Housing and Urban Development Regulations Relating to Housing and Urban... DESIGNATIONS Nomination Procedure § 598.205 What are the requirements for nomination? (a) General. No urban... that the strategic plan described in § 598.215 will be implemented, and these governments submit its...

24 CFR 598.205 - What are the requirements for nomination?

Code of Federal Regulations, 2014 CFR

2014-04-01

... nomination? 598.205 Section 598.205 Housing and Urban Development Regulations Relating to Housing and Urban... DESIGNATIONS Nomination Procedure § 598.205 What are the requirements for nomination? (a) General. No urban... that the strategic plan described in § 598.215 will be implemented, and these governments submit its...

76 FR 71566 - Solicitation of Nominations for Membership on the National Vaccine Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-18

...., Public Health Advisor, National Vaccine Program Office, Department of Health and Human Services, 200... vacated during the calendar year 2012. Nominations In accordance with the charter, persons nominated for... information should be included in the package of material submitted for each individual being nominated for...

78 FR 31939 - Solicitation of Nominations for Membership on the National Vaccine Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-28

...., Public Health Advisor, National Vaccine Program Office, Department of Health and Human Services, 200... vacated during the calendar year 2013. Nominations In accordance with the charter, persons nominated for... information should be included in the package of material submitted for each individual being nominated for...

7 CFR 25.502 - Nominations by State-chartered economic development corporations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 1 2010-01-01 2010-01-01 false Nominations by State-chartered economic development... AND ENTERPRISE COMMUNITIES Special Rules § 25.502 Nominations by State-chartered economic development corporations. Any rural area nominated by an economic development corporation chartered by a State and...

75 FR 28782 - Extension of Period for Nominations to the National Medal of Technology and Innovation Nomination...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-24

... innovation and/or be familiar with the education, training, employment and management of technological... Innovations/Bioengineering and Biomedical Technology; Technology Management/Computing/IT/Manufacturing...] Extension of Period for Nominations to the National Medal of Technology and Innovation Nomination Evaluation...

Exploring Reference Group Effects on Teachers' Nominations of Gifted Students

ERIC Educational Resources Information Center

Rothenbusch, Sandra; Zettler, Ingo; Voss, Thamar; Lösch, Thomas; Trautwein, Ulrich

2016-01-01

Teachers are often asked to nominate students for enrichment programs for gifted children, and studies have repeatedly indicated that students' intelligence is related to their likelihood of being nominated as gifted. However, it is unknown whether class-average levels of intelligence influence teachers' nominations as suggested by theory--and…

Trajectories of Peer-Nominated Aggression: Risk Status, Predictors and Outcomes.

ERIC Educational Resources Information Center

van Lier, Pol A.C.; Crijnen, Alfons A.M.

2005-01-01

Developmental trajectories of peer-nominated aggression, risk factors at baseline, and outcomes were studied. Peer nominations of aggression were obtained annually from grades 1 to 3. Three developmental trajectories were identified: an early-onset/increasers trajectory with high levels of peer-nominated aggression at elementary school entry and…

36 CFR 60.10 - Concurrent State and Federal nominations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... cultural value. Federal agencies may nominate properties where a portion of the property is not under Federal ownership or control. (b) When a portion of the area included in a Federal nomination is not... cultural resource, the completed nomination form shall be sent to the State Historic Preservation Officer...

45 CFR 1801.10 - Nomination by institution of higher education.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 4 2013-10-01 2013-10-01 false Nomination by institution of higher education. 1801.10 Section 1801.10 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.10 Nomination by...

45 CFR 1801.11 - Annual nomination.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Annual nomination. 1801.11 Section 1801.11 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.11 Annual nomination. (a) Except as provided in §§ 1801.11...

45 CFR 1801.11 - Annual nomination.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 4 2014-10-01 2014-10-01 false Annual nomination. 1801.11 Section 1801.11 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.11 Annual nomination. (a) Except as provided in §§ 1801.11...

45 CFR 1801.11 - Annual nomination.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 4 2013-10-01 2013-10-01 false Annual nomination. 1801.11 Section 1801.11 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.11 Annual nomination. (a) Except as provided in §§ 1801.11...

45 CFR 1801.10 - Nomination by institution of higher education.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Nomination by institution of higher education. 1801.10 Section 1801.10 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.10 Nomination by...

45 CFR 1801.10 - Nomination by institution of higher education.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 4 2014-10-01 2014-10-01 false Nomination by institution of higher education. 1801.10 Section 1801.10 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.10 Nomination by...

45 CFR 1801.11 - Annual nomination.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Annual nomination. 1801.11 Section 1801.11 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.11 Annual nomination. (a) Except as provided in §§ 1801.11...

45 CFR 1801.11 - Annual nomination.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 4 2012-10-01 2012-10-01 false Annual nomination. 1801.11 Section 1801.11 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.11 Annual nomination. (a) Except as provided in §§ 1801.11...

45 CFR 1801.10 - Nomination by institution of higher education.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 4 2012-10-01 2012-10-01 false Nomination by institution of higher education. 1801.10 Section 1801.10 Public Welfare Regulations Relating to Public Welfare (Continued) HARRY S. TRUMAN SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM Nominations § 1801.10 Nomination by...

7 CFR 25.502 - Nominations by State-chartered economic development corporations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 1 2013-01-01 2013-01-01 false Nominations by State-chartered economic development... AND ENTERPRISE COMMUNITIES Special Rules § 25.502 Nominations by State-chartered economic development corporations. Any rural area nominated by an economic development corporation chartered by a State and...

7 CFR 25.502 - Nominations by State-chartered economic development corporations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 1 2014-01-01 2014-01-01 false Nominations by State-chartered economic development... AND ENTERPRISE COMMUNITIES Special Rules § 25.502 Nominations by State-chartered economic development corporations. Any rural area nominated by an economic development corporation chartered by a State and...

7 CFR 25.502 - Nominations by State-chartered economic development corporations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 1 2011-01-01 2011-01-01 false Nominations by State-chartered economic development... AND ENTERPRISE COMMUNITIES Special Rules § 25.502 Nominations by State-chartered economic development corporations. Any rural area nominated by an economic development corporation chartered by a State and...

7 CFR 25.502 - Nominations by State-chartered economic development corporations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 1 2012-01-01 2012-01-01 false Nominations by State-chartered economic development... AND ENTERPRISE COMMUNITIES Special Rules § 25.502 Nominations by State-chartered economic development corporations. Any rural area nominated by an economic development corporation chartered by a State and...

77 FR 48168 - Call for Nominations for the Twin Falls District Resource Advisory Council

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-13

... for Nominations for the Twin Falls District Resource Advisory Council AGENCY: Bureau of Land Management, Interior. ACTION: Call for Nominations, Twin Falls District Resource Advisory Council SUMMARY: This notice requests public nominations to fill one position on the Twin Falls District Resource...

75 FR 69631 - National Medal of Technology and Innovation Nomination Evaluation Committee Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-15

... selection. NMTI Nomination Evaluation Committee members are drawn from both the public and private sectors... Technology and Innovation Nomination Evaluation Committee Meeting AGENCY: United States Patent and Trademark... Innovation (NMTI) Nomination Evaluation Committee will meet in closed session on Tuesday, November 30, 2010...

7 CFR 930.25 - Failure to nominate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Failure to nominate. 930.25 Section 930.25 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Administrative Body § 930.25 Failure to nominate. If nominations are not made within the time and in the manner...

7 CFR 959.28 - Failure to nominate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Failure to nominate. 959.28 Section 959.28 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Committee § 959.28 Failure to nominate. If nominations are not made within the time and...

7 CFR 959.28 - Failure to nominate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Failure to nominate. 959.28 Section 959.28 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Committee § 959.28 Failure to nominate. If nominations are not made within the time and...

7 CFR 930.25 - Failure to nominate.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Failure to nominate. 930.25 Section 930.25 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Administrative Body § 930.25 Failure to nominate. If nominations are not made within the time and in the manner...

7 CFR 945.26 - Failure to nominate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Failure to nominate. 945.26 Section 945.26 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... § 945.26 Failure to nominate. If nominations are not made within the time and in the manner specified by...

7 CFR 930.25 - Failure to nominate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Failure to nominate. 930.25 Section 930.25 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Administrative Body § 930.25 Failure to nominate. If nominations are not made within the time and in the manner...

7 CFR 945.26 - Failure to nominate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Failure to nominate. 945.26 Section 945.26 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... § 945.26 Failure to nominate. If nominations are not made within the time and in the manner specified by...

7 CFR 966.28 - Failure to nominate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Failure to nominate. 966.28 Section 966.28 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Regulating Handling Committee § 966.28 Failure to nominate. If nominations are not made within the time and...

7 CFR 958.29 - Failure to nominate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Failure to nominate. 958.29 Section 958.29 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Failure to nominate. If nominations are not made within the time and in the manner specified by the...

7 CFR 930.25 - Failure to nominate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Failure to nominate. 930.25 Section 930.25 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Administrative Body § 930.25 Failure to nominate. If nominations are not made within the time and in the manner...

7 CFR 924.24 - Failure to nominate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Failure to nominate. 924.24 Section 924.24 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements....24 Failure to nominate. If nominations are not made within the time and in the manner prescribed in...

7 CFR 930.25 - Failure to nominate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Failure to nominate. 930.25 Section 930.25 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Administrative Body § 930.25 Failure to nominate. If nominations are not made within the time and in the manner...

7 CFR 958.29 - Failure to nominate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Failure to nominate. 958.29 Section 958.29 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Failure to nominate. If nominations are not made within the time and in the manner specified by the...

7 CFR 958.29 - Failure to nominate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Failure to nominate. 958.29 Section 958.29 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Failure to nominate. If nominations are not made within the time and in the manner specified by the...

7 CFR 945.26 - Failure to nominate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Failure to nominate. 945.26 Section 945.26 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... § 945.26 Failure to nominate. If nominations are not made within the time and in the manner specified by...

7 CFR 966.28 - Failure to nominate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Failure to nominate. 966.28 Section 966.28 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Committee § 966.28 Failure to nominate. If nominations are not made within the time and...

7 CFR 945.26 - Failure to nominate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Failure to nominate. 945.26 Section 945.26 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... § 945.26 Failure to nominate. If nominations are not made within the time and in the manner specified by...

7 CFR 945.26 - Failure to nominate.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Failure to nominate. 945.26 Section 945.26 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... § 945.26 Failure to nominate. If nominations are not made within the time and in the manner specified by...

7 CFR 959.28 - Failure to nominate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Failure to nominate. 959.28 Section 959.28 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Regulating Handling Committee § 959.28 Failure to nominate. If nominations are not made within the time and...

7 CFR 924.24 - Failure to nominate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Failure to nominate. 924.24 Section 924.24 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements....24 Failure to nominate. If nominations are not made within the time and in the manner prescribed in...

Mars Exploration Rovers: 4 Years on Mars

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.

2008-01-01

This January, the Mars Exploration Rovers "Spirit" and "Opportunity" are starting their fifth year of exploring the surface of Mars, well over ten times their nominal 90-day design lifetime. This lecture discusses the Mars Exploration Rovers, presents the current mission status for the extended mission, some of the most results from the mission and how it is affecting our current view of Mars, and briefly presents the plans for the coming NASA missions to the surface of Mars and concepts for exploration with robots and humans into the next decade, and beyond.

Replacing the CCSDS Telecommand Protocol with the Next Generation Uplink (NGU)

NASA Technical Reports Server (NTRS)

Kazz, Greg J.; Greenberg, Ed; Burleigh, Scott C.

2012-01-01

The current CCSDS Telecommand (TC) Recommendations 1-3 have essentially been in use since the early 1960s. The purpose of this paper is to propose a successor protocol to TC. The current CCSDS recommendations can only accommodate telecommand rates up to approximately 1 mbit/s. However today's spacecraft are storehouses for software including software for Field Programmable Gate Arrays (FPGA) which are rapidly replacing unique hardware systems. Changes to flight software occasionally require uplinks to deliver very large volumes of data. In the opposite direction, high rate downlink missions that use acknowledged CCSDS File Delivery Protocol (CFDP)4 will increase the uplink data rate requirements. It is calculated that a 5 mbits/s downlink could saturate a 4 kbits/s uplink with CFDP downlink responses: negative acknowledgements (NAKs), FINISHs, End-of-File (EOF), Acknowledgements (ACKs). Moreover, it is anticipated that uplink rates of 10 to 20 mbits/s will be required to support manned missions. The current TC recommendations cannot meet these new demands. Specifically, they are very tightly coupled to the Bose-Chaudhuri-Hocquenghem (BCH) code in Ref. 2. This protocol requires that an uncorrectable BCH codeword delimit the TC frame and terminate the randomization process. This method greatly limits telecom performance since only the BCH code can support the protocol. More modern techniques such as the CCSDS Low Density Parity Check (LDPC)5 codes can provide a minimum performance gain of up to 6 times higher command data rates as long as sufficient power is available in the data. This paper will describe the proposed protocol format, trade-offs, and advantages offered, along with a discussion of how reliable communications takes place at higher nominal rates.

Investigation of configuration effects on entry heating distributions at Mach no. equal 8.0 (OH41). [for wind tunnel model of space shuttle orbiter

NASA Technical Reports Server (NTRS)

Gorowitz, H.; White, R.; Derrico, A.

1973-01-01

Aerodynamic heating data were obtained on 0.006 scale models of four Rockwell International SSV double delta wing Orbiters in the Mach 8 variable density tunnel. A model of two previously tested Rockwell International Orbiters which are identified in the Configuration Description of this report were also tested. Orbiter surfaces were thermally mapped from the laminar through turbulent flight regimes during re-entry. Various modifications were made to model lower surfaces to determine the cause of transition in the vicinity of 3.0 million Reynolds number per foot. Re-entry data were acquired for angles of attack from 25 through 35 degrees at nominal Reynolds numbers per foot of 1.0, 2.0, 2.3, 2.5, 3.0, 3.5, 4.5 and 6.0 million utilizing the phase change paint technique. Launch data were acquired on the model upper surfaces for angles of attack of 0 and -5 degrees at nominal Reynolds numbers per foot of 3.0 and 6.0 million. A total of 70 orbiter heating runs and 6 material sample sphere runs were completed.

Effect of surface state on the oxidation behavior of welded 308L in simulated nominal primary water of PWR

NASA Astrophysics Data System (ADS)

Ming, Hongliang; Zhang, Zhiming; Wang, Jiazhen; Zhu, Ruolin; Ding, Jie; Wang, Jianqiu; Han, En-Hou; Ke, Wei

2015-05-01

The oxidation behavior of 308L weld metal (WM) with different surface state in the simulated nominal primary water of pressurized water reactor (PWR) was studied by scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) analyzer and X-ray photoelectron spectroscopy (XPS). After 480 h immersion, a duplex oxide film composed of a Fe-rich outer layer (Fe3O4, Fe2O3 and a small amount of NiFe2O4, Ni(OH)2, Cr(OH)3 and (Ni, Fe)Cr2O4) and a Cr-rich inner layer (FeCr2O4 and NiCr2O4) can be formed on the 308L WM samples with different surface state. The surface state has no influence on the phase composition of the oxide films but obviously affects the thickness of the oxide films and the morphology of the oxides (number & size). With increasing the density of dislocations and subgrain boundaries in the cold-worked superficial layer, the thickness of the oxide film, the number and size of the oxides decrease.

Conduction below 100 °C in nominal Li 6ZnNb 4O 14

DOE PAGES

Li, Yunchao; Paranthaman, Mariappan Parans; Gill, Lance W.; ...

2015-09-15

The increasing demand for a safe rechargeable battery with a high energy density per cell is driving a search for a novel solid electrolyte with a high Li + or Na + conductivity that is chemically stable in a working Li-ion or Na-ion battery. Li 6ZnNb 4O 14 has been reported to exhibit a σ Li > 10 -2 S cm -1 at 250 °C, but to disproportionate into multiple phases on cooling from 850 °C to room temperature. An investigation of the room-temperature Li-ion conductivity in a porous pellet of a multiphase product of a nominal Li 6ZnNb 4Omore » 14 composition is shown to have bulk σ Li 3.3 x 10 -5 S cm -1 at room temperature that increases to 1.4 x 10 -4 S cm -1 by 50 °C. 7Li MAS NMR spectra were fitted to two Lorentzian lines, one of which showed a dramatic increase with increasing temperature. As a result, a test for water stability indicates that Li + may move to the particle and grain surfaces to react with adsorbed water as occurs in the garnet Li + conductors.« less

Processing Control Information in a Nominal Control Construction: An Eye-Tracking Study

ERIC Educational Resources Information Center

Kwon, Nayoung; Sturt, Patrick

2016-01-01

In an eye-tracking experiment, we examined the processing of the nominal control construction. Participants' eye-movements were monitored while they read sentences that included either giver control nominals (e.g. "promise" in "Luke's promise to Sophia to photograph himself") or recipient control nominals (e.g. "plea"…

Methodological Choices in Peer Nomination Research

ERIC Educational Resources Information Center

Cillessen, Antonius H. N.; Marks, Peter E. L.

2017-01-01

Although peer nomination measures have been used by researchers for nearly a century, common methodological practices and rules of thumb (e.g., which variables to measure; use of limited vs. unlimited nomination methods) have continued to develop in recent decades. At the same time, other key aspects of the basic nomination procedure (e.g.,…

24 CFR 598.200 - Who nominates an area for designation?

Code of Federal Regulations, 2012 CFR

2012-04-01

... designation? 598.200 Section 598.200 Housing and Urban Development Regulations Relating to Housing and Urban... DESIGNATIONS Nomination Procedure § 598.200 Who nominates an area for designation? Applicants for empowerment... the area is located, except as provided in §§ 598.500, 598.510, and 598.515. The nomination must be...

24 CFR 598.200 - Who nominates an area for designation?

Code of Federal Regulations, 2013 CFR

2013-04-01

... designation? 598.200 Section 598.200 Housing and Urban Development Regulations Relating to Housing and Urban... DESIGNATIONS Nomination Procedure § 598.200 Who nominates an area for designation? Applicants for empowerment... the area is located, except as provided in §§ 598.500, 598.510, and 598.515. The nomination must be...

24 CFR 598.200 - Who nominates an area for designation?

Code of Federal Regulations, 2014 CFR

2014-04-01

... designation? 598.200 Section 598.200 Housing and Urban Development Regulations Relating to Housing and Urban... DESIGNATIONS Nomination Procedure § 598.200 Who nominates an area for designation? Applicants for empowerment... the area is located, except as provided in §§ 598.500, 598.510, and 598.515. The nomination must be...

75 FR 79061 - Self-Regulatory Organizations; Municipal Securities Rulemaking Board; Notice of Filing of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-17

... securities advisors--the Commission seeks comment on whether the proposed structure of the MSRB Nominating... membership on the Board, in order to establish a Nominating Committee in compliance with MSRB transitional... appropriate prior to the creation of the Nominating Committee of the MSRB (hereinafter, ``Nominating and...

76 FR 76732 - Nominations to the Advisory Committee on Blood Safety and Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-08

... individuals will be nominated to the Secretary of HHS for consideration of appointment as members of the ACBSA..., Associate Public Health Advisor for Blood, Organ and Tissue Safety Policy, Department of Health and Human.... Nominations In accordance with the charter, persons nominated for appointment as members of the ACBSA should...

40 CFR 105.9 - How can I get nominated for an award?

Code of Federal Regulations, 2011 CFR

2011-07-01

...? 105.9 Section 105.9 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS RECOGNITION AWARDS UNDER THE CLEAN WATER ACT Application and Nomination Process § 105.9 How can I get nominated for an award? You may apply to, or ask your State, Tribe or EPA Region to nominate you...

40 CFR 105.9 - How can I get nominated for an award?

Code of Federal Regulations, 2013 CFR

2013-07-01

...? 105.9 Section 105.9 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS RECOGNITION AWARDS UNDER THE CLEAN WATER ACT Application and Nomination Process § 105.9 How can I get nominated for an award? You may apply to, or ask your State, Tribe or EPA Region to nominate you...

40 CFR 105.9 - How can I get nominated for an award?

Code of Federal Regulations, 2014 CFR

2014-07-01

...? 105.9 Section 105.9 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS RECOGNITION AWARDS UNDER THE CLEAN WATER ACT Application and Nomination Process § 105.9 How can I get nominated for an award? You may apply to, or ask your State, Tribe or EPA Region to nominate you...

40 CFR 105.9 - How can I get nominated for an award?

Code of Federal Regulations, 2012 CFR

2012-07-01

...? 105.9 Section 105.9 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS RECOGNITION AWARDS UNDER THE CLEAN WATER ACT Application and Nomination Process § 105.9 How can I get nominated for an award? You may apply to, or ask your State, Tribe or EPA Region to nominate you...

40 CFR 105.9 - How can I get nominated for an award?

Code of Federal Regulations, 2010 CFR

2010-07-01

...? 105.9 Section 105.9 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS RECOGNITION AWARDS UNDER THE CLEAN WATER ACT Application and Nomination Process § 105.9 How can I get nominated for an award? You may apply to, or ask your State, Tribe or EPA Region to nominate you...

24 CFR 597.502 - Nominations by economic development corporations or the District of Columbia.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Nominations by economic development... ZONES AND ENTERPRISE COMMUNITIES: ROUND ONE DESIGNATIONS Special Rules § 597.502 Nominations by economic development corporations or the District of Columbia. Any urban area nominated by an Economic Development...

77 FR 63827 - Request for Nominations of Experts for the Clean Air Scientific Advisory Committee (CASAC) Oxides...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-17

... health-based) air quality standards for oxides of nitrogen (NO X ). DATES: Nominations should be..., medicine, public health, biostatistics and risk assessment. Process and Deadline for Submitting Nominations... later than November 7, 2012. EPA values and welcomes diversity. In an effort to obtain nominations of...

24 CFR 598.510 - Nominations by Economic Development Corporations or the District of Columbia.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Nominations by Economic Development... ZONES: ROUND TWO AND THREE DESIGNATIONS Special Rules § 598.510 Nominations by Economic Development Corporations or the District of Columbia. Any urban area nominated by an Economic Development Corporation...

10 CFR 960.3-2-2 - Nomination of sites as suitable for characterization.

Code of Federal Regulations, 2010 CFR

2010-01-01

... OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2 Nomination of... of each repository site. For the second repository, at least three of the sites shall not have been nominated previously. Any site nominated as suitable for characterization for the first repository, but not...

24 CFR 597.502 - Nominations by economic development corporations or the District of Columbia.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 24 Housing and Urban Development 3 2012-04-01 2012-04-01 false Nominations by economic development... ZONES AND ENTERPRISE COMMUNITIES: ROUND ONE DESIGNATIONS Special Rules § 597.502 Nominations by economic development corporations or the District of Columbia. Any urban area nominated by an Economic Development...

24 CFR 598.510 - Nominations by Economic Development Corporations or the District of Columbia.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 24 Housing and Urban Development 3 2012-04-01 2012-04-01 false Nominations by Economic Development... ZONES: ROUND TWO AND THREE DESIGNATIONS Special Rules § 598.510 Nominations by Economic Development Corporations or the District of Columbia. Any urban area nominated by an Economic Development Corporation...

Cognitive Implications of Nominalizations in the Advancement of Scientific Discourse

ERIC Educational Resources Information Center

Bello, Iria

2016-01-01

Nominalizations are well-known features of scientific writing. Scholars have been intrigued by their form and by their functions. While these features have been widely studied, the cognitive side of nominalizations in scientific texts still needs further attention. Nominalizations contribute to the advancement of discourse and at the same time add…

76 FR 21085 - Self-Regulatory Organizations; NASDAQ Stock Market, LLC; Order Approving Proposed Rule Change To...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-14

... the Nominating & Governance Committee; (ii) amend the NASDAQ OMX PHLX, Inc. reference to reflect a... Nominating Committee also conducts certain governance functions such as consulting with the Board and the... ``Nominating Committee'' in the By-Laws, to the ``Nominating & Governance Committee'' so that the title of the...

49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not known...

49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not known...

49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not known...

49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not known...

49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not known...

Gout and comorbidity: a nominal group study of people with gout.

PubMed

Singh, Jasvinder A

2017-09-15

Comorbidities are common in patients with gout, yet qualitative research is lacking. The study objective was to examine the impact of gout on comorbidities. Nine nominal groups were conducted. Patients with gout discussed and rank-ordered their concerns in response to the question, "How does gout or its treatment affect your other conditions and their treatment?" Nine nominal groups had 45 gout patients, with mean age 61 years (standard deviation (SD) 10.7) and mean gout duration 14.9 years (SD 12). Of these, 62% were men, 45% African-American, 51% married and 63% were currently using allopurinol. The most frequently cited highly ranked concerns among the nine nominal groups were: (1) interaction of gout medication with medications for other medical conditions (three groups); (2) worsening of other medical comorbidities, including hospitalizations (seven groups); (3) worsening of anxiety and depression (three groups); (4) significant dietary changes for gout that contrasted with diet for other conditions (three groups); (5) new diseases diagnosed due to gout (three groups); (6) irreversible joint damage (three groups); (7) inability to exercise and weight gain (four groups); and (8) gout misdiagnosed as another health condition (three groups). Other domains ranked highly were: (1) impact of gout on daily life and activities, including the ability to work and social activities (six groups); (2) medication side effects, real and perceived (nine groups); (3) weight loss due to gout related to frequent flares (one group); and (4) cost and burden (three groups). Gout and the medications used for its treatment have a significant effect on comorbidities and their management. These findings provide insights into potential targets for improving outcomes in patients with gout.

A Comparison of mucosal surface area and villous histology in small intestines of the Brazilian free-tailed bat (Tadarida brasiliensis) and the mouse (Mus musculus).

PubMed

Zhang, Zhi-Qiang; Brun, Antonio; Price, Edwin R; Cruz-Neto, Ariovaldo P; Karasov, William H; Caviedes-Vidal, Enrique

2015-01-01

Studies on birds have led to the hypothesis that increased intestinal absorption between enterocytes (paracellular) evolved as a compensation for smaller intestinal size in fliers, which was perhaps selected to minimize the mass of digesta carried. This hypothesis predicts that bats will also exhibit relatively reduced intestinal size and high paracellular absorption, compared with nonflying mammals. Published studies on three bat species indicate relatively high paracellular absorption. One mechanism for increasing paracellular absorption per cm2 small intestine (SI) is increased number of tight junctions (TJs) across which paracellular absorption occurs. To our knowledge, we provide the first comparative analysis of enterocyte size and number in flying and nonflying mammals. Intestines of insectivorous bats Tadarida brasiliensis were compared with Mus musculus using hematoxylin and eosin staining method. Bats had shorter and narrower SIs than mice, and after correction for body size difference by normalizing to mass3/4, the bats had 40% less nominal surface area than the mouse, as predicted. Villous enhancement of surface area was 90% greater in the bat than in the mouse, mainly because of longer villi and a greater density of villi in bat intestines. Bat and mouse were similar in enterocyte diameter. Bats exceeded mice by 54.4% in villous area per cm length SI and by 95% in number of enterocytes per cm2 of the nominal surface area of the SI. Therefore, an increased density of TJs per cm2 SI may be a mechanistic explanation that helps to understand the high paracellular absorption observed in bats compared to nonflying mammals. © 2014 Wiley Periodicals, Inc.

Acceleration processes in the quasi-steady magnetoplasmadynamic discharge. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Boyle, M. J.

1974-01-01

The flow field characteristics within the discharge chamber and exhaust of a quasi-steady magnetoplasmadynamic (MPD) arcjet were examined to clarify the nature of the plasma acceleration process. The observation of discharge characteristics unperturbed by insulator ablation and terminal voltage fluctuations, first requires the satisfaction of three criteria: the use of refractory insulator materials; a mass injection geometry tailored to provide propellant to both electrode regions of the discharge; and a cathode of sufficient surface area to permit nominal MPD arcjet operation for given combinations of arc current and total mass flow. The axial velocity profile and electromagnetic discharge structure were measured for an arcjet configuration which functions nominally at 15.3 kA and 6 g/sec argon mass flow. An empirical two-flow plasma acceleration model is advanced which delineates inner and outer flow regions and accounts for the observed velocity profile and calculated thrust of the accelerator.

Catalog of the Neotropical Trichoptera (Caddisflies)

PubMed Central

Holzenthal, Ralph W.; Calor, Adolfo R.

2017-01-01

Abstract The Neotropical caddisfly (Trichoptera) fauna is cataloged from a review of over 1,000 literature citations through 2015 (partial 2016) to include 3,262 currently recognized, valid species-group names in 25 families and 155 extant genera. Fourteen subspecies are included in the total as well as 35 fossil species and 1 fossil genus. The region covered includes all of Mexico, Central America, the Caribbean, and South America. Genus-group and species-group synonyms are listed. For each nominal species, information on the type locality, type depository, sex of type, distribution by country, and other pertinent taxonomic or biological information is included. Summary information on taxonomy, phylogeny, distribution, immature stages, and biology are provided for each family and genus where known. An extensive index to all nominal taxa is included to facilitate use of the catalog. The glossosomatid species Mexitrichia usseglioi Rueda Martín & Gibon, is transferred to Mortoniella comb. n. PMID:28331396

Brief report: Trait emotional intelligence, peer nominations, and scholastic achievement in adolescence.

PubMed

Mancini, Giacomo; Andrei, Federica; Mazzoni, Elvis; Biolcati, Roberta; Baldaro, Bruno; Trombini, Elena

2017-08-01

Current research on trait EI in adolescents suggests that the construct impacts on several important domains of youths' psychological functioning, including school adjustment and achievement. The purpose of this study is to explore the role of trait EI and of its subcomponents, on adolescent's academic achievement. Data were collected from 321 Italian adolescents (162 female; Mage = 15.5, SD = 1.86; aged 13-18 years) recruited from secondary schools. The effects of perceived and actual peer nominations, gender, personality dimensions, and non-verbal cognitive abilities were also controlled. Results highlight that trait EI as assessed by means of the TEIQue impacts Italian but not math's grades, while trait EI's factors predicted both academic subjects, with significant contributions of Self-Control and Sociability. Limitations and implications are discussed. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Crew Exploration Vehicle Launch Abort Controller Performance Analysis

NASA Technical Reports Server (NTRS)

Sparks, Dean W., Jr.; Raney, David L.

2007-01-01

This paper covers the simulation and evaluation of a controller design for the Crew Module (CM) Launch Abort System (LAS), to measure its ability to meet the abort performance requirements. The controller used in this study is a hybrid design, including features developed by the Government and the Contractor. Testing is done using two separate 6-degree-of-freedom (DOF) computer simulation implementations of the LAS/CM throughout the ascent trajectory: 1) executing a series of abort simulations along a nominal trajectory for the nominal LAS/CM system; and 2) using a series of Monte Carlo runs with perturbed initial flight conditions and perturbed system parameters. The performance of the controller is evaluated against a set of criteria, which is based upon the current functional requirements of the LAS. Preliminary analysis indicates that the performance of the present controller meets (with the exception of a few cases) the evaluation criteria mentioned above.

EPS analysis of nominal STS-1 flight

NASA Technical Reports Server (NTRS)

Wolfgram, D. F.; Pipher, M. D.

1980-01-01

The results of electrical power system (EPS) analysis of the planned Shuttle Transportation System Flight 1 mission are presented. The capability of the orbiter EPS to support the planned flight and to provide program tape information and supplementary data specifically requested by the flight operations directorate was assessed. The analysis was accomplished using the orbiter version of the spacecraft electrical power simulator program, operating from a modified version of orbiter electrical equipment utilization baseline revision four. The results indicate that the nominal flight, as analyzed, is within the capabilities of the orbiter power generation system, but that a brief, and minimal, current overload may exist between main distributor 1 and mid power controlled 1, and that inverter 9 may the overloaded for extended periods of time. A comparison of results with launch commit criteria also indicated that some of the presently existing launch redlines may be violated during the terminal countdown.

Magnetization measurements on multifilamentary No/sub 3/Sn and NbTi conductors

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

Ghosh, A.K.; Robins, K.E.; Sampson, W.B.

1985-03-01

The effective filament size has been determined for a number of high current Nb/sub 3/Sn multifilamentary composites. In most cases it is much larger than the nominal filament size. For the smallest filaments (..integral.. 1 micron) the effective size can be as much as a factor of forty times the nominal size. Samples made by the ''internal tin'', ''bronze route'', and ''jelly roll'' methods have been examined with filaments in the range one to ten microns. Rate dependent magnetization and ''flux'' jumping'' have been observed in some cases. NbTi composites ranging in filament size from nine to two hundred micronsmore » and with copper to super-conductor ratios between 1.6:1 and 7:1 have been examined in the same apparatus. Low field ''flux jumping'' was only observed in conductors with very large filaments and relatively little stabilizing copper.« less

Full power level development of the Space Shuttle main engine

NASA Technical Reports Server (NTRS)

Johnson, J. R.; Colbo, H. I.

1982-01-01

Development of the Space Shuttle main engine for nominal operation at full power level (109 percent rated power) is continuing in parallel with the successful flight testing of the Space Transportation System. Verification of changes made to the rated power level configuration currently being flown on the Orbiter Columbia is in progress and the certification testing of the full power level configuration has begun. The certification test plan includes the accumulation of 10,000 seconds on each of two engines by early 1983. Certification testing includes the simulation of nominal mission duty cycles as well as the two abort thrust profiles: abort to orbit and return to launch site. Several of the certification tests are conducted at 111 percent power to demonstrate additional safety margins. In addition to the flight test and development program results, future plans for life demonstration and engine uprating will be discussed.

Variation of magnetoimpedance of electrodeposited NiFe/Cu with deposition current density

NASA Astrophysics Data System (ADS)

Mishra, A. C.; Jha, A. K.

2017-12-01

An investigation about influence of deposition current density on electrodeposited magnetic film is reported in this paper. Ferromagnetic NiFe thin films were electrodeposited on copper wires of 100 μm diameter for various electrdepostion current densities ranging from 10 to 60 mA/cm2 maintaining equal thickness in all films. The composition of deposited film varied with deposition current density and in particular, a composition of Ni79Fe21 was achieved for a current density of 20 mA/cm2. The surface microstructure of the film deposited at the current density of 20 mA/cm2 was found to have excellent smoothness. The coercivity of the film was lowest and highest value of magnetoimpedance was measured for this film. The influence of current density on film composition and hence magnetic properties was attributed to the change of deposition mechanism.

Improved UTE-based attenuation correction for cranial PET-MR using dynamic magnetic field monitoring

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

Aitken, A. P.; Giese, D.; Tsoumpas, C.

2014-01-15

Purpose: Ultrashort echo time (UTE) MRI has been proposed as a way to produce segmented attenuation maps for PET, as it provides contrast between bone, air, and soft tissue. However, UTE sequences require samples to be acquired during rapidly changing gradient fields, which makes the resulting images prone to eddy current artifacts. In this work it is demonstrated that this can lead to misclassification of tissues in segmented attenuation maps (AC maps) and that these effects can be corrected for by measuring the true k-space trajectories using a magnetic field camera. Methods: The k-space trajectories during a dual echo UTEmore » sequence were measured using a dynamic magnetic field camera. UTE images were reconstructed using nominal trajectories and again using the measured trajectories. A numerical phantom was used to demonstrate the effect of reconstructing with incorrect trajectories. Images of an ovine leg phantom were reconstructed and segmented and the resulting attenuation maps were compared to a segmented map derived from a CT scan of the same phantom, using the Dice similarity measure. The feasibility of the proposed method was demonstrated inin vivo cranial imaging in five healthy volunteers. Simulated PET data were generated for one volunteer to show the impact of misclassifications on the PET reconstruction. Results: Images of the numerical phantom exhibited blurring and edge artifacts on the bone–tissue and air–tissue interfaces when nominal k-space trajectories were used, leading to misclassification of soft tissue as bone and misclassification of bone as air. Images of the tissue phantom and thein vivo cranial images exhibited the same artifacts. The artifacts were greatly reduced when the measured trajectories were used. For the tissue phantom, the Dice coefficient for bone in MR relative to CT was 0.616 using the nominal trajectories and 0.814 using the measured trajectories. The Dice coefficients for soft tissue were 0.933 and 0.934 for the nominal and measured cases, respectively. For air the corresponding figures were 0.991 and 0.993. Compared to an unattenuated reference image, the mean error in simulated PET uptake in the brain was 9.16% when AC maps derived from nominal trajectories was used, with errors in the SUV{sub max} for simulated lesions in the range of 7.17%–12.19%. Corresponding figures when AC maps derived from measured trajectories were used were 0.34% (mean error) and −0.21% to +1.81% (lesions). Conclusions: Eddy current artifacts in UTE imaging can be corrected for by measuring the true k-space trajectories during a calibration scan and using them in subsequent image reconstructions. This improves the accuracy of segmented PET attenuation maps derived from UTE sequences and subsequent PET reconstruction.« less

Effect of cadmium in sediments on colonization by benthic marine organisms: Role of interstitial cadmium and acid volatile sulfide in bioavailability

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

Hansen, D.; Berry, W.; Benyi, S.

1995-12-31

The role of interstitial cadmium and acid volatile sulfide (AVS) in controlling the bioavailability of sediment-associated metal was examined using the chronic saltwater benthic colonization test. Sediments were spiked with cadmium to achieve simultaneously extracted metal (SEM)/AVS molar ratios of 0. 0 (control), 0.1, 0.8 and 3.0 in this 118-day test. Oxidation of AVS in the surficial 2.4 cm within two to four weeks resulted in sulfide profiles similar to those occurring naturally in local sediments. In the nominal 0.1 SEM/AVS treatment, measured SEM was always less than AVS. Interstitial cadmium concentrations (< 3--10 {micro}g/L) were below those likely tomore » cause biological effects. No significant biological effects were detected. In the nominal 0.8 SEM/AVS treatment, measured SEM commonly exceeded AVS in the surficial 2.4 cm of sediment. Interstitial cadmium concentrations (24--157 {micro}g/L) were likely of toxicological significance to sensitive species. Shifts were observed in presence/absence of species, and there were fewer macrobenthic polychaetes (Mediomastus ambiseta, Strebloapio benedicti and Podarke obscura) and unidentified meiofaunal nematodes. In the nominal 3.0 SEM/AVS treatment, concentrations of SEM were always greater than AVS throughout the sediment column. Interstitial cadmium ranged from 28,000 to 174,000 {micro}g/L. In addition to the effects above, these sediments were colonized by fewer macrobenthic species, polychaete species and harpacticoids; had lower densities of diatoms; lacked bivalve molluscs and exhibited other impacts. The observed biological responses were consistent with measured SEM/AVS ratios in surficial sediments and interstitial water cadmium concentrations, further supporting their utility in predicting metals bioavailability.« less

Near-surface Density Currents Observed in the Southeast Pacific Stratocumulus-topped Marine Boundary Layer

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

Wilbanks, Matt C.; Yuter, S. E.; de Szoeke, S.

2015-09-01

Density currents (i.e. cold pools or outflows) beneath marine stratocumulus clouds are characterized using a 30-d data set of ship-based observations obtained during the 2008 Variability of American Monsoon Systems (VAMOS) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) in the southeast Pacific. An objective method identifies 71 density current fronts using an air density criterion and isolates each density current’s core (peak density) and tail (dissipating) zone. Compared to front and core zones, most density current tails exhibited weaker density gradients and wind anomalies elongated about the axis of the mean wind. The mean cloud-level advection relative to the surface layer windmore » (1.9 m s-1) nearly matches the mean density current propagation speed (1.8 m s-1). The similarity in speeds allows drizzle cells to deposit tails in their wakes. Based on high-resolution scanning Doppler lidar data, prefrontal updrafts had a mean intensity of 0.91 m s-1, reached an average altitude of 800 m, and were often surmounted by low-lying shelf clouds not connected to the overlying stratocumulus cloud. Nearly 90% of density currents were identified when C-band radar estimated 30-km diameter areal average rain rates exceeded 1 mm d-1. Rather than peaking when rain rates are highest overnight, density current occurrence peaks between 0600 and 0800 local solar time when enhanced local drizzle co-occurs with shallow subcloud dry and stable layers. The dry layers may contribute to density current formation by enhancing subcloud evaporation of drizzle. Density currents preferentially occur in regions of open cells but also occur in regions of closed cells.« less

78 FR 13103 - Self-Regulatory Organizations; NYSE Arca, Inc.; Notice of Filing of Proposed Rule Change Amending...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-26

... Arca Bylaws or rules, the Nominating Committee of NYSE Arca Holdings shall nominate directors for... provided in the NYSE Arca Bylaws or rules, the Holding Member shall nominate directors for election at the... specifically provide for a Nominating Committee. The NYSE Group Bylaws are available at http://usequities.nyx...

76 FR 30939 - Science Advisory Board Staff Office; Request for Nominations of Experts for SAB Libby Amphibole...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-27

... Nominations of Experts for SAB Libby Amphibole Asbestos Review Panel AGENCY: Environmental Protection Agency... nominations of technical experts to serve on an Asbestos expert panel under the auspices of the SAB to conduct a peer review of EPA's Draft Toxicological Review of Libby Amphibole Asbestos. DATES: Nominations...

36 CFR 73.7 - World Heritage nomination process.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false World Heritage nomination process. 73.7 Section 73.7 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR WORLD HERITAGE CONVENTION § 73.7 World Heritage nomination process. (a) What is the U.S. World Heritage nomination process? (1) The...

New Understanding of Hubble Space Telescope Gyro Current Increase Led to a Method to Save a Failing Gyro

NASA Technical Reports Server (NTRS)

Blumenstock, Kenneth A.

2017-01-01

Throughout the history of the Hubble Space Telescope (HST) program, gyro current increases have been observed to occur, oftentimes leading to gyro failure. The explanation was that debris from the surfaces of the gas bearings, with only 50 millionths on an inch clearance, resulted in rotor restriction, which increased friction, torque, and current. However, the rotor restriction theory never could account for the fact that a restart of the gyro would restore the current back to nominal. An effort was made to understand this puzzling gyro behavior after two HST gyros exhibited increased current within the same week in November 2015. A review board was created to resolve these anomalies and generate operational procedures to potentially extend gyro life.

Nigeria: Current Issues

DTIC Science & Technology

2007-04-12

Hausa-Fulani, the southwestern Yoruba , and the southeastern Ibo have traditionally been the most politically active and dominant. Almost half of the...Adamawa State in the January elections, was chosen by the PDP as the running mate of Obasanjo, a Yoruba from southwestern Nigeria. The APP and AD...nominated Chief Olu Falae, a Yoruba , as their joint candidate for president. A former Nigerian security chief and a northerner, Chief Umaru Shinakfi, was

On the Nature of Agreement in English-French Acquisition: A Processing Investigation in the Verbal and Nominal Domains

ERIC Educational Resources Information Center

Renaud, Claire

2010-01-01

Current second language (L2) research focuses on the level of features--that is, the core elements of languages in the Minimalist Program framework. These features, involved in computations, are further divided into two types: those that indicate to which category a word belongs (i.e., interpretable features) versus those that constrain the type…

75 FR 51295 - In the Matter of the Application of BATS Y-Exchange, Inc. for Registration as a National...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-19

... things, a Director that is or has been within the past three years an officer, director, employee, or... completion of its respective duties for nominating directors for election to the Board for that year, shall nominate candidates to serve on the succeeding year's Nominating Committee or Member Nominating Committee...

Nominations for NSF, NSB

NASA Astrophysics Data System (ADS)

President Ronald Reagan plans to nominate William J. Merrell, Jr., to be assistant director of the National Science Foundation (NSF) for Astronomical, Atmospheric, Earth, and Ocean Sciences (AAEO), according to an announcement by NSF. The President also has announced his intention to nominate Craig C. Black and Charles L. Hosier to the National Science Board (NSB), NSF said. The president's nominations are subject to Senate confirmation.

Particle Image Velocimetry Study of Density Current Fronts

ERIC Educational Resources Information Center

Martin, Juan Ezequiel

2009-01-01

Gravity currents are flows that occur when a horizontal density difference causes fluid to move under the action of gravity; density currents are a particular case, for which the scalar causing the density difference is conserved. Flows with a strong effect of the horizontal density difference, even if only partially driven by it--such as the…

Correcting magnetic probe perturbations on current density measurements of current carrying plasmas.

PubMed

Knoblauch, P; Raspa, V; Di Lorenzo, F; Lazarte, A; Clausse, A; Moreno, C

2010-09-01

A method to infer the current density distribution in the current sheath of a plasma focus discharge from a magnetic probe is formulated and then applied to experimental data obtained in a 1.1 kJ device. Distortions on the magnetic probe signal caused by current redistribution and by a time-dependent total discharge current are considered simultaneously, leading to an integral equation for the current density. Two distinct, easy to implement, numerical procedures are given to solve such equation. Experimental results show the coexistence of at least two maxima in the current density structure of a nitrogen sheath.

Impact of Te and ne on edge current density profiles in ELM mitigated regimes on ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Dunne, M. G.; Rathgeber, S.; Burckhart, A.; Fischer, R.; Giannone, L.; McCarthy, P. J.; Schneider, P. A.; Wolfrum, E.; the ASDEX Upgrade Team

2015-01-01

ELM resolved edge current density profiles are reconstructed using the CLISTE equilibrium code. As input, highly spatially and temporally resolved edge electron temperature and density profiles are used in addition to data from the extensive set of external poloidal field measurements available at ASDEX Upgrade, flux loop difference measurements, and current measurements in the scrape-off layer. Both the local and flux surface averaged current density profiles are analysed for several ELM mitigation regimes. The focus throughout is on the impact of altered temperature and density profiles on the current density. In particular, many ELM mitigation regimes rely on operation at high density. Two reference plasmas with type-I ELMs are analysed, one with a deuterium gas puff and one without, in order to provide a reference for the behaviour in type-II ELMy regimes and high density ELM mitigation with external magnetic perturbations at ASDEX Upgrade. For type-II ELMs it is found that while a similar pedestal top pressure is sustained at the higher density, the temperature gradient decreases in the pedestal. This results in lower local and flux surface averaged current densities in these phases, which reduces the drive for the peeling mode. No significant differences between the current density measured in the type-I phase and ELM mitigated phase is seen when external perturbations are applied, though the pedestal top density was increased. Finally, ELMs during the nitrogen seeded phase of a high performance discharge are analysed and compared to ELMs in the reference phase. An increased pedestal pressure gradient, which is the source of confinement improvement in impurity seeded discharges, causes a local current density increase. However, the increased Zeff in the pedestal acts to reduce the flux surface averaged current density. This dichotomy, which is not observed in other mitigation regimes, could act to stabilize both the ballooning mode and the peeling mode at the same time.

Silicon-Based Lithium-Ion Capacitor for High Energy and High Power Application

NASA Technical Reports Server (NTRS)

Wu, James J.; Demattia, Brianne; Loyselle, Patricia; Reid, Concha; Kohout, Lisa

2017-01-01

Si-based Li-ion capacitor has been developed and demonstrated. The results show it is feasible to improve both power density and energy density in this configuration. The applied current density impacts the power and energy density: low current favors energy density while high current favors power density. Active carbon has a better rate capability than Si. Next StepsFuture Directions. Si electrode needs to be further studied and improved. Further optimization of SiAC ratio and evaluation of its impact on energy density and power density.

Vitamin B1

MedlinePlus

... Medicine Prize Literature Prize Peace Prize Prize in Economic Sciences Quick Facts Nomination Nomination Physics Prize Chemistry ... Medicine Prize Literature Prize Peace Prize Prize in Economic Sciences Nomination Archive Ceremonies Ceremonies Ceremony Archive Nobel ...

Fourier transform magnetic resonance current density imaging (FT-MRCDI) from one component of magnetic flux density.

PubMed

Ider, Yusuf Ziya; Birgul, Ozlem; Oran, Omer Faruk; Arikan, Orhan; Hamamura, Mark J; Muftuler, L Tugan

2010-06-07

Fourier transform (FT)-based algorithms for magnetic resonance current density imaging (MRCDI) from one component of magnetic flux density have been developed for 2D and 3D problems. For 2D problems, where current is confined to the xy-plane and z-component of the magnetic flux density is measured also on the xy-plane inside the object, an iterative FT-MRCDI algorithm is developed by which both the current distribution inside the object and the z-component of the magnetic flux density on the xy-plane outside the object are reconstructed. The method is applied to simulated as well as actual data from phantoms. The effect of measurement error on the spatial resolution of the current density reconstruction is also investigated. For 3D objects an iterative FT-based algorithm is developed whereby the projected current is reconstructed on any slice using as data the Laplacian of the z-component of magnetic flux density measured for that slice. In an injected current MRCDI scenario, the current is not divergence free on the boundary of the object. The method developed in this study also handles this situation.

In-vivo measurement of relationship between applied current amplitude and current density magnitude from 10 mA to 110 mA.

PubMed

DeMonte, Tim P; Wang, Dinghui; Ma, Weijing; Gao, Jia-Hong; Joy, Michael L G

2009-01-01

Current density imaging (CDI) is a magnetic resonance imaging (MRI) technique used to quantitatively measure current density vectors throughout the volume of an object/subject placed in the MRI system. Electrical current pulses are applied externally to the object/subject and are synchronized with the MRI sequence. In this work, CDI is used to measure average current density magnitude in the torso region of an in-vivo piglet for applied current pulse amplitudes ranging from 10 mA to 110 mA. The relationship between applied current amplitude and current density magnitude is linear in simple electronic elements such as wires and resistors; however, this relationship may not be linear in living tissue. An understanding of this relationship is useful for research in defibrillation, human electro-muscular incapacitation (e.g. TASER(R)) and other bioelectric stimulation devices. This work will show that the current amplitude to current density magnitude relationship is slightly nonlinear in living tissue in the range of 10 mA to 110 mA.

Space-charge-limited currents for cathodes with electric field enhanced geometry

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

Lai, Dingguo, E-mail: laidingguo@nint.ac.cn; Qiu, Mengtong; Xu, Qifu

This paper presents the approximate analytic solutions of current density for annulus and circle cathodes. The current densities of annulus and circle cathodes are derived approximately from first principles, which are in agreement with simulation results. The large scaling laws can predict current densities of high current vacuum diodes including annulus and circle cathodes in practical applications. In order to discuss the relationship between current density and electric field on cathode surface, the existing analytical solutions of currents for concentric cylinder and sphere diodes are fitted from existing solutions relating with electric field enhancement factors. It is found that themore » space-charge-limited current density for the cathode with electric-field enhanced geometry can be written in a general form of J = g(β{sub E}){sup 2}J{sub 0}, where J{sub 0} is the classical (1D) Child-Langmuir current density, β{sub E} is the electric field enhancement factor, and g is the geometrical correction factor depending on the cathode geometry.« less

Reverse leakage current characteristics of InGaN/GaN multiple quantum well ultraviolet/blue/green light-emitting diodes

NASA Astrophysics Data System (ADS)

Zhou, Shengjun; Lv, Jiajiang; Wu, Yini; Zhang, Yuan; Zheng, Chenju; Liu, Sheng

2018-05-01

We investigated the reverse leakage current characteristics of InGaN/GaN multiple quantum well (MQW) near-ultraviolet (NUV)/blue/green light-emitting diodes (LEDs). Experimental results showed that the NUV LED has the smallest reverse leakage current whereas the green LED has the largest. The reason is that the number of defects increases with increasing nominal indium content in InGaN/GaN MQWs. The mechanism of the reverse leakage current was analyzed by temperature-dependent current–voltage measurement and capacitance–voltage measurement. The reverse leakage currents of NUV/blue/green LEDs show similar conduction mechanisms: at low temperatures, the reverse leakage current of these LEDs is attributed to variable-range hopping (VRH) conduction; at high temperatures, the reverse leakage current of these LEDs is attributed to nearest-neighbor hopping (NNH) conduction, which is enhanced by the Poole–Frenkel effect.

Molecular mechanics and structure of the fluid-solid interface in simple fluids

NASA Astrophysics Data System (ADS)

Wang, Gerald J.; Hadjiconstantinou, Nicolas G.

2017-09-01

Near a fluid-solid interface, the fluid spatial density profile is highly nonuniform at the molecular scale. This nonuniformity can have profound effects on the dynamical behavior of the fluid and has been shown to play an especially important role when modeling a wide variety of nanoscale heat and momentum transfer phenomena. We use molecular-mechanics arguments and molecular-dynamics (MD) simulations to develop a better understanding of the structure of the first fluid layer directly adjacent to the solid in the layering regime, as delineated by a nondimensional number that compares the effects of wall-fluid interaction to thermal energy. Using asymptotic analysis of the Nernst-Planck equation, we show that features of the fluid density profile close to the wall, such as the areal density of the first layer ΣFL (defined as the number of atoms in this layer per unit of fluid-solid interfacial area), can be expressed as polynomial functions of the fluid average density ρave. This is found to be in agreement with MD simulations, which also show that the width of the first layer hFL is a linear function of the average density and only a weak function of the temperature T . These results can be combined to show that, for system average densities corresponding to a dense fluid (ρave≥0.7 ), the ratio C ≡ΣFLρavehFL, representing a density enhancement with respect to the bulk fluid, depends only weakly on temperature and is essentially independent of density. Further MD simulations suggest that the above results, nominally valid for large systems (solid in contact with semi-infinite fluid), also describe fluid-solid interfaces under considerable nanoconfinement, provided ρave is appropriately defined.

Variants for HDL-C, LDL-C, and triglycerides identified from admixture mapping and fine-mapping analysis in African American families.

PubMed

Shetty, Priya B; Tang, Hua; Feng, Tao; Tayo, Bamidele; Morrison, Alanna C; Kardia, Sharon L R; Hanis, Craig L; Arnett, Donna K; Hunt, Steven C; Boerwinkle, Eric; Rao, Dabeeru C; Cooper, Richard S; Risch, Neil; Zhu, Xiaofeng

2015-02-01

Admixture mapping of lipids was followed-up by family-based association analysis to identify variants for cardiovascular disease in African Americans. The present study conducted admixture mapping analysis for total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. The analysis was performed in 1905 unrelated African American subjects from the National Heart, Lung and Blood Institute's Family Blood Pressure Program (FBPP). Regions showing admixture evidence were followed-up with family-based association analysis in 3556 African American subjects from the FBPP. The admixture mapping and family-based association analyses were adjusted for age, age(2), sex, body mass index, and genome-wide mean ancestry to minimize the confounding caused by population stratification. Regions that were suggestive of local ancestry association evidence were found on chromosomes 7 (low-density lipoprotein cholesterol), 8 (high-density lipoprotein cholesterol), 14 (triglycerides), and 19 (total cholesterol and triglycerides). In the fine-mapping analysis, 52 939 single-nucleotide polymorphisms (SNPs) were tested and 11 SNPs (8 independent SNPs) showed nominal significant association with high-density lipoprotein cholesterol (2 SNPs), low-density lipoprotein cholesterol (4 SNPs), and triglycerides (5 SNPs). The family data were used in the fine-mapping to identify SNPs that showed novel associations with lipids and regions, including genes with known associations for cardiovascular disease. This study identified regions on chromosomes 7, 8, 14, and 19 and 11 SNPs from the fine-mapping analysis that were associated with high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides for further studies of cardiovascular disease in African Americans. © 2014 American Heart Association, Inc.

Current density imaging sequence for monitoring current distribution during delivery of electric pulses in irreversible electroporation.

PubMed

Serša, Igor; Kranjc, Matej; Miklavčič, Damijan

2015-01-01

Electroporation is gaining its importance in everyday clinical practice of cancer treatment. For its success it is extremely important that coverage of the target tissue, i.e. treated tumor, with electric field is within the specified range. Therefore, an efficient tool for the electric field monitoring in the tumor during delivery of electroporation pulses is needed. The electric field can be reconstructed by the magnetic resonance electric impedance tomography method from current density distribution data. In this study, the use of current density imaging with MRI for monitoring current density distribution during delivery of irreversible electroporation pulses was demonstrated. Using a modified single-shot RARE sequence, where four 3000 V and 100 μs long pulses were included at the start, current distribution between a pair of electrodes inserted in a liver tissue sample was imaged. Two repetitions of the sequence with phases of refocusing radiofrequency pulses 90° apart were needed to acquire one current density image. For each sample in total 45 current density images were acquired to follow a standard protocol for irreversible electroporation where 90 electric pulses are delivered at 1 Hz. Acquired current density images showed that the current density in the middle of the sample increased from first to last electric pulses by 60%, i.e. from 8 kA/m2 to 13 kA/m2 and that direction of the current path did not change with repeated electric pulses significantly. The presented single-shot RARE-based current density imaging sequence was used successfully to image current distribution during delivery of short high-voltage electric pulses. The method has a potential to enable monitoring of tumor coverage by electric field during irreversible electroporation tissue ablation.

Preliminary Correlations of Gravity and Topography from Mars Global Surveyor

NASA Technical Reports Server (NTRS)

Zuber, M. T.; Tyler, G. L.; Smith, D. E.; Balmino, G. S.; Johnson, G. L.; Lemoine, F. G.; Neumann, G. A.; Phillips, R. J.; Sjogren, W. L.; Solomon, S. C.

1999-01-01

The Mars Global Surveyor (MGS) spacecraft is currently in a 400-km altitude polar mapping orbit and scheduled to begin global mapping of Mars in March of 1999. Doppler tracking data collected in this Gravity Calibration Orbit prior to the nominal mapping mission combined with observations from the MGS Science Phasing Orbit in Spring - Summer 1999 and the Viking and mariner 9 orbiters has led to preliminary high resolution gravity fields. Spherical harmonic expansions have been performed to degree and order 70 and are characterized by the first high spatial resolution coverage of high latitudes. Topographic mapping by the Mars Orbiter Laser Altimeter on MGS is providing measurements of the height of the martian surface with sub-meter vertical resolution and 5-30 m absolute accuracy. Data obtained during the circular mapping phase are expected to provide the first high resolution measurements of surface heights in the southern hemisphere. The combination of gravity and topography measurements provides information on the structure of the planetary interior, i.e. the rigidity and distribution of internal density. The observations can also be used to address the mechanisms of support of surface topography. Preliminary results of correlations of gravity and topography at long planetary wavelengths will be presented and the implications for internal structure will be addressed.

Schottky barrier height of Ni to β-(AlxGa1-x)2O3 with different compositions grown by plasma-assisted molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Ahmadi, Elaheh; Oshima, Yuichi; Wu, Feng; Speck, James S.

2017-03-01

Coherent β-(AlxGa1-x)2O3 films (x = 0, 0.038, 0.084, 0.164) were grown successfully on a Sn-doped β-Ga2O3 (010) substrate using plasma-assisted molecular beam epitaxy. Atom probe tomography, transmission electron microscopy, and high resolution x-ray diffraction were used to verify the alloy composition and high quality of the films. Schottky diodes were then fabricated using Ni as the Schottky metal. Capacitance-voltage measurements revealed a very low (<7 × 1015 cm-3) free charge density in the nominally undoped films. The barrier height and ideality factor were estimated by current-voltage (I-V) measurements performed at temperatures varying from 300 K to 500 K on the Schottky diodes. These measurements revealed that the apparent Schottky barrier height could have similar values for different compositions of β-(AlxGa1-x)2O3. We believe this is attributed to the lateral fluctuation in the alloy’s composition. This results in a lateral variation in the barrier height. Therefore, the average Schottky barrier height extracted from I-V measurements could be similar for β-(AlxGa1-x)2O3 films with different compositions.

Reinforced Electrode Architecture for a Flexible Battery with Paperlike Characteristics

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

Gaikwad, AM; Chu, HN; Qeraj, R

2013-02-10

Compliant energy storage has not kept pace with flexible electronics. Herein we demonstrate a technique to reinforce arbitrary battery electrodes by supporting them with mechanically tough, low-cost fibrous membranes, which also serve as the separator. The membranes were laminated to form a full cell, and this stacked membrane reinforcement bears the loads during flexing. This technique was used to make a high energy density, nontoxic Zn-MnO2 battery with printed current collectors. The Zn and MnO2 electrodes were prepared by using a solution-based embedding process. The cell had a nominal potential of 1.5 V and an effective capacity of approximately 3more » mA h cm(-2). We investigated the effect of bending and fatigue on the electrochemical performance and mechanical integrity of the battery. The battery was able to maintain its capacity even after 1000 flex cycles to a bend radius of 2.54 cm. The battery showed an improvement in discharge capacity (ca. 10%) if the MnO2 electrode was flexed to tension as a result of the improvement of particle-to-particle contact. In a demonstration, the flexible battery was used to power a light-emitting diode display integrated with a strain sensor and microcontroller.« less