Using Technology Readiness Level (TRL), Life Cycle Cost (LCC), and Other Metrics to Supplement Equivalent System Mass (ESM) in Advanced Life Support (ALS)

NASA Technical Reports Server (NTRS)

Jones, Harry

2003-01-01

The ALS project plan goals are reducing cost, improving performance, and achieving flight readiness. ALS selects projects to advance the mission readiness of low cost, high performance technologies. The role of metrics is to help select good projects and report progress. The Equivalent Mass (EM) of a system is the sum of the estimated mass of the hardware, of its required materials and spares, and of the pressurized volume, power supply, and cooling system needed to support the hardware in space. EM is the total payload launch mass needed to provide and support a system. EM is directly proportional to the launch cost.

Extended long-wavelength lambda = 11-15-micron GaAs/Al(x)Ga(1-x)As quantum-well infrared photodetectors

NASA Technical Reports Server (NTRS)

Zussman, A.; Levine, B. F.; Kuo, J. M.; De Jong, J.

1991-01-01

Success has been achieved in extending the spectral wavelength of GaAs/Al(x)Ga(1-x)As quantum-well infrared photodetectors to significantly longer wavelengths of 11-15 micron. High responsivity of 0.5 A/W, high quantum efficiency of 12 percent, and high detectivity as well as an excellent noise equivalent temperature difference of 4 mK have been achieved at T = 50 K. High performance of 19 mK has also been achieved at an even higher temperature of 60 K.

Computer simulations and models for the performance characteristics of spectrally equivalent X-ray beams in medical diagnostic radiology

PubMed Central

Okunade, Akintunde A.

2007-01-01

In order to achieve uniformity in radiological imaging, it is recommended that the concept of equivalence in shape (quality) and size (quantity) of clinical Xray beams should be used for carrying out the comparative evaluation of image and patient dose. When used under the same irradiation geometry, X-ray beams that are strictly or relatively equivalent in terms of shape and size will produce identical or relatively identical image quality and patient dose. Simple mathematical models and software program EQSPECT.FOR were developed for the comparative evaluation of the performance characteristics in terms of contrast (C), contrast to noise ratio (CNR) and figure-of-merit (FOM = CNR2/DOSE) for spectrally equivalent beams transmitted through filter materials referred to as conventional and k-edged. At the same value of operating potential (kVp), results show that spectrally equivalent beam transmitted through conventional filter with higher atomic number (Z-value) in comparison with that transmitted through conventional filter with lower Z-value resulted in the same value of C and FOM. However, in comparison with the spectrally equivalent beam transmitted through filter of lower Z-value, the beam through filter of higher Z-value produced higher value of CNR and DOSE at equal tube loading (mAs) and kVp. Under the condition of equivalence of spectrum, at scaled (or reduced) tube loading and same kVp, filter materials of higher Z-value can produce the same values of C, CNR, DOSE and FOM as filter materials of lower Z-value. Unlike the case of comparison of spectrally equivalent beam transmitted through one conventional filter and that through another conventional filter, it is not possible to derive simple mathematical formulations for the relative performance of spectrally equivalent beam transmitted through a given conventional filter material and that through kedge filter material. PMID:21224928

40 CFR 51.353 - Network type and program evaluation.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., decentralized, or a hybrid of the two at the State's discretion, but shall be demonstrated to achieve the same... § 51.351 or 51.352 of this subpart. For decentralized programs other than those meeting the design.... (a) Presumptive equivalency. A decentralized network consisting of stations that only perform...

Role of preoperative cycloplegic refraction in LASIK treatment of hyperopia.

PubMed

Frings, Andreas; Steinberg, Johannes; Druchkiv, Vasyl; Linke, Stephan J; Katz, Toam

2016-07-01

Previous studies have suggested that, to improve refractive predictability in hyperopic LASIK treatments, preoperative cycloplegic or manifest refraction, or a combination of both, could be used in the laser nomogram. We set out to investigate (1) the prevalence of a high difference between manifest and cycloplegic spherical equivalent in hyperopic eyes preoperatively, and (2) the related predictability of postoperative keratometry. Retrospective cross-sectional data analysis of consecutive treated 186 eyes from 186 consecutive hyperopic patients (mean age 42 [±12] years) were analyzed. Excimer ablation for all eyes was performed using a mechanical microkeratome (SBK, Moria, France) and an Allegretto excimer laser platform. Two groups were defined according to the difference between manifest and cycloplegic spherical equivalent which was defined as ≥1.00 diopter (D); the data was analyzed according to refractive outcome in terms of refractive predictability, efficacy, and safety. In 24 eyes (13 %), a preoperative difference of ≥1.00D between manifest spherical equivalent and cycloplegic spherical equivalent (= MCD) occurred. With increasing preoperative MCD, the postoperative achieved spherical equivalent showed hyperopic regression after 3 months. There was no statistically significant effect of age (accommodation) or optical zone size on the achieved spherical equivalent. A difference of ≥1.00D occurs in about 13 % of hyperopia cases. We suggest that hyperopic correction should be based on the manifest spherical equivalent in eyes with preoperative MCD <1.00D. If the preoperative MCD is ≥1.00D, treatment may produce manifest undercorrection, and therefore we advise that the patient should be warrned about lower predictability, and suggest basing conclusions on the arithmetic mean calculated from the preoperative manifest and cycloplegic spheres.

Calculation of reaction forces in the boiler supports using the method of equivalent stiffness of membrane wall.

PubMed

Sertić, Josip; Kozak, Dražan; Samardžić, Ivan

2014-01-01

The values of reaction forces in the boiler supports are the basis for the dimensioning of bearing steel structure of steam boiler. In this paper, the application of the method of equivalent stiffness of membrane wall is proposed for the calculation of reaction forces. The method of equalizing displacement, as the method of homogenization of membrane wall stiffness, was applied. On the example of "Milano" boiler, using the finite element method, the calculation of reactions in the supports for the real geometry discretized by the shell finite element was made. The second calculation was performed with the assumption of ideal stiffness of membrane walls and the third using the method of equivalent stiffness of membrane wall. In the third case, the membrane walls are approximated by the equivalent orthotropic plate. The approximation of membrane wall stiffness is achieved using the elasticity matrix of equivalent orthotropic plate at the level of finite element. The obtained results were compared, and the advantages of using the method of equivalent stiffness of membrane wall for the calculation of reactions in the boiler supports were emphasized.

Rich-burn, flame-assisted fuel cell, quick-mix, lean-burn (RFQL) combustor and power generation

NASA Astrophysics Data System (ADS)

Milcarek, Ryan J.; Ahn, Jeongmin

2018-03-01

Micro-tubular flame-assisted fuel cells (mT-FFC) were recently proposed as a modified version of the direct flame fuel cell (DFFC) operating in a dual chamber configuration. In this work, a rich-burn, quick-mix, lean-burn (RQL) combustor is combined with a micro-tubular solid oxide fuel cell (mT-SOFC) stack to create a rich-burn, flame-assisted fuel cell, quick-mix, lean-burn (RFQL) combustor and power generation system. The system is tested for rapid startup and achieves peak power densities after only 35 min of testing. The mT-FFC power density and voltage are affected by changes in the fuel-lean and fuel-rich combustion equivalence ratio. Optimal mT-FFC performance favors high fuel-rich equivalence ratios and a fuel-lean combustion equivalence ratio around 0.80. The electrical efficiency increases by 150% by using an intermediate temperature cathode material and improving the insulation. The RFQL combustor and power generation system achieves rapid startup, a simplified balance of plant and may have applications for reduced NOx formation and combined heat and power.

Performance of InGaAs short wave infrared avalanche photodetector for low flux imaging

NASA Astrophysics Data System (ADS)

Singh, Anand; Pal, Ravinder

2017-11-01

Opto-electronic performance of the InGaAs/i-InGaAs/InP short wavelength infrared focal plane array suitable for high resolution imaging under low flux conditions and ranging is presented. More than 85% quantum efficiency is achieved in the optimized detector structure. Isotropic nature of the wet etching process poses a challenge in maintaining the required control in the small pitch high density detector array. Etching process is developed to achieve low dark current density of 1 nA/cm2 in the detector array with 25 µm pitch at 298 K. Noise equivalent photon performance less than one is achievable showing single photon detection capability. The reported photodiode with low photon flux is suitable for active cum passive imaging, optical information processing and quantum computing applications.

Design and evaluation of cellular power converter architectures

NASA Astrophysics Data System (ADS)

Perreault, David John

Power electronic technology plays an important role in many energy conversion and storage applications, including machine drives, power supplies, frequency changers and UPS systems. Increases in performance and reductions in cost have been achieved through the development of higher performance power semiconductor devices and integrated control devices with increased functionality. Manufacturing techniques, however, have changed little. High power is typically achieved by paralleling multiple die in a sing!e package, producing the physical equivalent of a single large device. Consequently, both the device package and the converter in which the device is used continue to require large, complex mechanical structures, and relatively sophisticated heat transfer systems. An alternative to this approach is the use of a cellular power converter architecture, which is based upon the parallel connection of a large number of quasi-autonomous converters, called cells, each of which is designed for a fraction of the system rating. The cell rating is chosen such that single-die devices in inexpensive packages can be used, and the cell fabricated with an automated assembly process. The use of quasi-autonomous cells means that system performance is not compromised by the failure of a cell. This thesis explores the design of cellular converter architectures with the objective of achieving improvements in performance, reliability, and cost over conventional converter designs. New approaches are developed and experimentally verified for highly distributed control of cellular converters, including methods for ripple cancellation and current-sharing control. The performance of these techniques are quantified, and their dynamics are analyzed. Cell topologies suitable to the cellular architecture are investigated, and their use for systems in the 5-500 kVA range is explored. The design, construction, and experimental evaluation of a 6 kW cellular switched-mode rectifier is also addressed. This cellular system implements entirely distributed control, and achieves performance levels unattainable with an equivalent single converter. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

Single shaft automotive gas turbine engine characterization test

NASA Technical Reports Server (NTRS)

Johnson, R. A.

1979-01-01

An automotive gas turbine incorporating a single stage centrifugal compressor and a single stage radial inflow turbine is described. Among the engine's features is the use of wide range variable geometry at the inlet guide vanes, the compressor diffuser vanes, and the turbine inlet vanes to achieve improved part load fuel economy. The engine was tested to determine its performance in both the variable geometry and equivalent fixed geometry modes. Testing was conducted without the originally designed recuperator. Test results were compared with the predicted performance of the nonrecuperative engine based on existing component rig test maps. Agreement between test results and the computer model was achieved.

Study of a Simulation Tool to Determine Achievable Control Dynamics and Control Power Requirements with Perfect Tracking

NASA Technical Reports Server (NTRS)

Ostroff, Aaron J.

1998-01-01

This paper contains a study of two methods for use in a generic nonlinear simulation tool that could be used to determine achievable control dynamics and control power requirements while performing perfect tracking maneuvers over the entire flight envelope. The two methods are NDI (nonlinear dynamic inversion) and the SOFFT(Stochastic Optimal Feedforward and Feedback Technology) feedforward control structure. Equivalent discrete and continuous SOFFT feedforward controllers have been developed. These equivalent forms clearly show that the closed-loop plant model loop is a plant inversion and is the same as the NDI formulation. The main difference is that the NDI formulation has a closed-loop controller structure whereas SOFFT uses an open-loop command model. Continuous, discrete, and hybrid controller structures have been developed and integrated into the formulation. Linear simulation results show that seven different configurations all give essentially the same response, with the NDI hybrid being slightly different. The SOFFT controller gave better tracking performance compared to the NDI controller when a nonlinear saturation element was added. Future plans include evaluation using a nonlinear simulation.

Fuel/air nonuniformity - Effect on nitric oxide emissions

NASA Technical Reports Server (NTRS)

Lyons, V. J.

1981-01-01

An analytical and experimental study was performed to determine the effect of inlet fuel/air profile nonuniformity on NO(x) emissions. The theoretical NO(x) levels were verified in a flame-tube rig at inlet air temperatures of 600, 700, and 800 K, 0.3 MPa rig pressure, 25 m/sec reference velocity, overall equivalence ratio of 0.6 and residence time near 0.002 sec. The theory predicts an increase in NO(x) emissions for increased fuel/air nonuniformity for average equivalence ratios less than 0.7, while for average equivalence ratios near stoichiometric, increasing the nonuniformity will decrease NO(x) emissions. The results can be used to predict the degree of uniformity of fuel/air profiles necessary to achieve NO(x) emissions goals for actual engines that use lean premixed, prevaporized combustion systems.

Lithium-ion battery cell-level control using constrained model predictive control and equivalent circuit models

NASA Astrophysics Data System (ADS)

Xavier, Marcelo A.; Trimboli, M. Scott

2015-07-01

This paper introduces a novel application of model predictive control (MPC) to cell-level charging of a lithium-ion battery utilizing an equivalent circuit model of battery dynamics. The approach employs a modified form of the MPC algorithm that caters for direct feed-though signals in order to model near-instantaneous battery ohmic resistance. The implementation utilizes a 2nd-order equivalent circuit discrete-time state-space model based on actual cell parameters; the control methodology is used to compute a fast charging profile that respects input, output, and state constraints. Results show that MPC is well-suited to the dynamics of the battery control problem and further suggest significant performance improvements might be achieved by extending the result to electrochemical models.

Six-month clinical outcomes after hyperopic correction with the SCHWIND AMARIS Total-Tech laser

PubMed Central

Arbelaez, María Clara; Vidal, Camila; Arba Mosquera, Samuel

2011-01-01

Purpose To evaluate postoperative clinical outcomes, and corneal High Order Aberrations, among eyes with hyperopia up to +5 D of spherical equivalent, that have undergone LASIK treatments using the SCHWIND AMARIS laser system. Methods At six-month follow-up, 100 eyes with preoperative hyperopia or hyperopic astigmatism up to +5 D of spherical equivalent were retrospectively analysed. Standard examinations, pre- and postoperative wavefront analysis with a corneal-wavefront-analyzer (OPTIKON Scout) were performed. Aberration-Free aspheric treatments were planned with Custom Ablation Manager software and ablations performed using the SCHWIND AMARIS flying-spot excimer laser system (both SCHWIND eye-tech-solutions). LASIK flaps were created using a LDV femtosecond laser (Ziemer Group) in all cases. Clinical outcomes were evaluated in terms of predictability, refractive outcome, safety, and wavefront aberration. Results At six month, 90 % of eyes achieved ≥ 20/25 UCVA and 44 % achieved ≥ 20/16 UCVA. Seventy-four percent of eyes were within ± 0.25D of spherical equivalent and 89 % within ± 0.50D, with 94 % within 0.50D of astigmatism. Mean spherical equivalent was −0.12 ± 0.51D and 0.50 ± 0.51D for the astigmatism. Fifty-two percent of eyes improved BSCVA vs. only 19 % losing lines of BSCVA. Predictability slope for refraction was 1.03 and intercept +0.01 D. On average, negative corneal spherical aberrations were significantly increased by the treatments, no other aberration terms changed from pre- to postoperative values. Conclusions LASIK for hyperopia and hyperopic astigmatism with SCHWIND AMARIS yields very satisfactory visual outcomes. Preoperative refractions were postoperatively reduced to subclinical values with no clinically relevant induction of corneal HOA.

Lean mixture engine testing and evaluation program. [for automobile engine pollution and fuel performances

NASA Technical Reports Server (NTRS)

Dowdy, M. W.; Hoehn, F. W.; Griffin, D. C.

1975-01-01

Experimental results for fuel consumption and emissions are presented for a 350 CID (5.7 liter) Chevrolet V-8 engine modified for lean operation with gasoline. The lean burn engine achieved peak thermal efficiency at an equivalence ratio of 0.75 and a spark advance of 60 deg BTDC. At this condition the lean burn engine demonstrated a 10% reduction in brake specific fuel consumption compared with the stock engine; however, NOx and hydrocarbon emissions were higher. With the use of spark retard and/or slightly lower equivalence ratios, the NOx emissions performance of the stock engine was matched while showing a 6% reduction in brake specific fuel consumption. Hydrocarbon emissions exceeded the stock values in all cases. Diagnostic data indicate that lean performance in the engine configuration tested is limited by ignition delay, cycle-to-cycle pressure variations, and cylinder-to-cylinder distribution.

Calculation of Reaction Forces in the Boiler Supports Using the Method of Equivalent Stiffness of Membrane Wall

PubMed Central

Sertić, Josip; Kozak, Dražan; Samardžić, Ivan

2014-01-01

The values of reaction forces in the boiler supports are the basis for the dimensioning of bearing steel structure of steam boiler. In this paper, the application of the method of equivalent stiffness of membrane wall is proposed for the calculation of reaction forces. The method of equalizing displacement, as the method of homogenization of membrane wall stiffness, was applied. On the example of “Milano” boiler, using the finite element method, the calculation of reactions in the supports for the real geometry discretized by the shell finite element was made. The second calculation was performed with the assumption of ideal stiffness of membrane walls and the third using the method of equivalent stiffness of membrane wall. In the third case, the membrane walls are approximated by the equivalent orthotropic plate. The approximation of membrane wall stiffness is achieved using the elasticity matrix of equivalent orthotropic plate at the level of finite element. The obtained results were compared, and the advantages of using the method of equivalent stiffness of membrane wall for the calculation of reactions in the boiler supports were emphasized. PMID:24959612

Moving Teachers: Implementation of Transfer Incentives in Seven Districts. Executive Summary. NCEE 2012-4052

ERIC Educational Resources Information Center

Glazerman, Steven; Protik, Ali; Teh, Bing-ru; Bruch, Julie; Seftor, Neil

2012-01-01

This report describes the implementation and intermediate impacts of an intervention designed to provide incentives for a school district's highest-performing teachers to work in its lowest-achieving schools. The report is part of a larger study in which random assignment was used to form two equivalent groups of classrooms organized into teacher…

Effectiveness of UK and International A-Level Assessment in Predicting Performance in Engineering

ERIC Educational Resources Information Center

Birch, David M.; Rienties, Bart

2014-01-01

In many universities, admissions decisions are made based upon the advanced-level (A-Level) results. The purpose of this study was to assess the value of A-level and international equivalents as a predictor of early achievement in higher education. About 135 UK and 92 international undergraduate engineering students from 35 countries were assessed…

Worldwide orthopaedic research activity 2010-2014: Publication rates in the top 15 orthopaedic journals related to population size and gross domestic product.

PubMed

Hohmann, Erik; Glatt, Vaida; Tetsworth, Kevin

2017-06-18

To perform a bibliometric analysis of publications rates in orthopedics in the top 15 orthopaedic journals. Based on their 2015 impact factor, the fifteen highest ranked orthopaedic journals between January 2010 and December 2014 were used to establish the total number of publications; cumulative impact factor points (IF) per country were determined, and normalized to population size, GDP, and GDP/capita, comparison to the median country output and the global leader. Twenty-three thousand and twenty-one orthopaedic articles were published, with 66 countries publishing. The United States had 8149 publications, followed by the United Kingdom (1644) and Japan (1467). The highest IF was achieved by the United States (24744), United Kingdom (4776), and Japan (4053). Normalized by population size Switzerland lead. Normalized by GDP, Croatia was the top achiever. Adjusting GDP/capita, for publications and IF, China, India, and the United States were the leaders. Adjusting for population size and GDP, 28 countries achieved numbers of publications to be considered at least equivalent with the median academic output. Adjusting GDP/capita only China and India reached the number of publications to be considered equivalent to the current global leader, the United States. Five countries were responsible for 60% of the orthopaedic research output over this 5-year period. After correcting for GDP/capita, only 28 of 66 countries achieved a publication rate equivalent to the median country. The United States, United Kingdom, South Korea, Japan, and Germany were the top five countries for both publication totals and cumulative impact factor points.

40 CFR 63.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Protection Agency. Equivalent emission limitation means any maximum achievable control technology emission... common control that is included in a section 112(c) source category or subcategory for which a section... pollutant at least equivalent to the reduction in emissions of such pollutant achieved under a relevant...

40 CFR 63.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection Agency. Equivalent emission limitation means any maximum achievable control technology emission... common control that is included in a section 112(c) source category or subcategory for which a section... pollutant at least equivalent to the reduction in emissions of such pollutant achieved under a relevant...

40 CFR 63.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Protection Agency. Equivalent emission limitation means any maximum achievable control technology emission... common control that is included in a section 112(c) source category or subcategory for which a section... pollutant at least equivalent to the reduction in emissions of such pollutant achieved under a relevant...

40 CFR 63.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Protection Agency. Equivalent emission limitation means any maximum achievable control technology emission... common control that is included in a section 112(c) source category or subcategory for which a section... pollutant at least equivalent to the reduction in emissions of such pollutant achieved under a relevant...

40 CFR 63.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Protection Agency. Equivalent emission limitation means any maximum achievable control technology emission... common control that is included in a section 112(c) source category or subcategory for which a section... pollutant at least equivalent to the reduction in emissions of such pollutant achieved under a relevant...

The Application of the EIS in Li-ion Batteries Measurement

NASA Astrophysics Data System (ADS)

Zhai, N. S.; Li, M. W.; Wang, W. L.; Zhang, D. L.; Xu, D. G.

2006-10-01

The measurement and determination of the lithium ion battery's electrochemical impedance spectroscopy (EIS) and the application of EIS to battery classification are researched in this paper. The lithium ion battery gets extensive applications due to its inherent advantages over other batteries. For proper and sustainable performance, it is very necessary to check the uniformity of the lithium ion batteries. In this paper, the equivalent circuit of the lithium ion battery is analyzed; the design of hardware circuit based on DSP and software that calculates the EIS of the lithium ion battery is critically done and evaluated. The parameters of the lithium ion equivalent circuit are determined, the parameter values of li-ion equivalent circuit are achieved by least square method, and the application of Principal Component Analysis (CPA) to the battery classification is analyzed.

Lithium-ion battery cell-level control using constrained model predictive control and equivalent circuit models

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

Xavier, MA; Trimboli, MS

This paper introduces a novel application of model predictive control (MPC) to cell-level charging of a lithium-ion battery utilizing an equivalent circuit model of battery dynamics. The approach employs a modified form of the MPC algorithm that caters for direct feed-though signals in order to model near-instantaneous battery ohmic resistance. The implementation utilizes a 2nd-order equivalent circuit discrete-time state-space model based on actual cell parameters; the control methodology is used to compute a fast charging profile that respects input, output, and state constraints. Results show that MPC is well-suited to the dynamics of the battery control problem and further suggestmore » significant performance improvements might be achieved by extending the result to electrochemical models. (C) 2015 Elsevier B.V. All rights reserved.« less

Coupling Light Emitting Diodes with Photocatalyst-Coated Optical Fibers Improves Quantum Yield of Pollutant Oxidation.

PubMed

Ling, Li; Tugaoen, Heather; Brame, Jonathon; Sinha, Shahnawaz; Li, Chuanhao; Schoepf, Jared; Hristovski, Kiril; Kim, Jae-Hong; Shang, Chii; Westerhoff, Paul

2017-11-21

A photocatalyst-coated optical fiber was coupled with a 318 nm ultraviolet-A light emitting diode, which activated the photocatalysts by interfacial photon-electron excitation while minimizing photonic energy losses due to conventional photocatalytic barriers. The light delivery mechanism was explored via modeling of evanescent wave energy produced upon total internal reflection and photon refraction into the TiO 2 surface coating. This work explores aqueous phase LED-irradiated optical fibers for treating organic pollutants and for the first time proposes a dual-mechanistic approach to light delivery and photocatalytic performance. Degradation of a probe organic pollutant was evaluated as a function of optical fiber coating thickness, fiber length, and photocatalyst attachment method and compared against the performance of an equivalent catalyst mass in a completely mixed slurry reactor. Measured and simulated photon fluence through the optical fibers decreased as a function of fiber length, coating thickness, or TiO 2 mass externally coated on the fiber. Thinner TiO 2 coatings achieved faster pollutant removal rates from solution, and dip coating performed better than sol-gel attachment methods. TiO 2 attached to optical fibers achieved a 5-fold higher quantum yield compared against an equivalent mass of TiO 2 suspended in a slurry solution.

NASA Instep/mdmsc Jitter Suppression Experiment (JITTER)

NASA Technical Reports Server (NTRS)

White, Edward V.

1992-01-01

The objectives are the following: (1) to develop and demonstrate in-space performance of both passive and active damping systems for suppression of micro-amplitude vibration on an actual application structure and operate despite uncertain dynamics and uncertain disturbance characteristics; and (2) to correlate ground and in-space performance - the performance metric is vibration attenuation. The goals are to achieve vibration suppression equivalent to 5 percent passive damping in selected models and 15 percent active damping in selected modes. Various aspects of this experiment are presented in viewgraph form.

Performance Comparison between CDTD and STTD for DS-CDMA/MMSE-FDE with Frequency-Domain ICI Cancellation

NASA Astrophysics Data System (ADS)

Takeda, Kazuaki; Kojima, Yohei; Adachi, Fumiyuki

Frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion can provide a better bit error rate (BER) performance than rake combining. However, the residual inter-chip interference (ICI) is produced after MMSE-FDE and this degrades the BER performance. Recently, we showed that frequency-domain ICI cancellation can bring the BER performance close to the theoretical lower bound. To further improve the BER performance, transmit antenna diversity technique is effective. Cyclic delay transmit diversity (CDTD) can increase the number of equivalent paths and hence achieve a large frequency diversity gain. Space-time transmit diversity (STTD) can obtain antenna diversity gain due to the space-time coding and achieve a better BER performance than CDTD. Objective of this paper is to show that the BER performance degradation of CDTD is mainly due to the residual ICI and that the introduction of ICI cancellation gives almost the same BER performance as STTD. This study provides a very important result that CDTD has a great advantage of providing a higher throughput than STTD. This is confirmed by computer simulation. The computer simulation results show that CDTD can achieve higher throughput than STTD when ICI cancellation is introduced.

The Effects of Self-Regulated Strategy Development on the Writing of Expository Essays for Adults with Written Expression Difficulties: Preparing for the GED

ERIC Educational Resources Information Center

Berry, Ann Bassett; Mason, Linda H.

2012-01-01

A multiple-probe, multiple-baseline, across-subjects design was used to examine the writing performance of four low-achieving adult students with and without disabilities enrolled in general equivalency diploma (GED) preparatory classes. Students' writing was evaluated before instruction and after self-regulated strategy development (SRSD)…

The Influence of Technology Usage on Academic Achievement (Reading and Math) from a Teacher's Perspective

ERIC Educational Resources Information Center

White-Harris, Kimberly L.

2017-01-01

The purpose of this study was to examine the perceptions of technology implementation of middle school teachers in one of the largest school districts in Alabama. This study examined if the use of technology had a positive influence on students' academic performance (reading and mathematics). Although several other studies are equivalent to this…

Are Schools Shortchanging Boys or Girls? The Answer Rests on Methods and Assumptions: Reply to Card (2014) and Penner (2014)

ERIC Educational Resources Information Center

Robinson-Cimpian, Joseph P.; Lubienski, Sarah Theule; Ganley, Colleen M.; Copur-Gencturk, Yasemin

2014-01-01

Our target article (Robinson-Cimpian, Lubienski, Ganley, & Copur-Gencturk, 2014) used nationally representative data to examine the development of gender gaps in math achievement. We found that when boys and girls demonstrate equivalent math test performance and are perceived by their teachers to be equally well behaved and engaged with the…

Grade Equivalents: We Report Them, You Should Too.

ERIC Educational Resources Information Center

Ligon, Glynn; Battaile, Richard

In certain situations, grade equivalent scores are the most appropriate statistic available for reporting achievement test data. It is noted that testing practitioners have found that raw scores, normal curve equivalents, stanines, and standard scores are very useful. However, it is best to convert to either grade equivalents or percentiles before…

Molecular dispersion spectroscopy based on Fabry-Perot quantum cascade lasers.

PubMed

Sterczewski, Lukasz A; Westberg, Jonas; Wysocki, Gerard

2017-01-15

Two Fabry-Perot quantum cascade lasers are used in a differential dual comb configuration to perform rapidly swept dispersion spectroscopy of low-pressure nitrous oxide with <1  ms acquisition time. Active feedback control of the laser injection current enables simultaneous wavelength modulation of both lasers at kilohertz rates. The system demonstrates similar performance in both absorption and dispersion spectroscopy modes and achieves a noise-equivalent absorption figure of merit in the low 10^-4/Hz range.

Metal-supported solid oxide fuel cells operated in direct-flame configuration

DOE PAGES

Tucker, Michael C.; Ying, Andrew S.

2017-08-19

Metal-supported solid oxide fuel cells (MS-SOFC) with infiltrated catalysts on both anode and cathode side are operated in direct-flame configuration, with a propane flame impinging on the anode. Placing thermal insulation on the cathode dramatically increases cell temperature and performance. The optimum burner-to-cell gap height is a strong function of flame conditions. Cell performance at the optimum gap is determined within the region of stable non-coking conditions, with equivalence ratio from 1 to 1.9 and flow velocity from 100 to 300 cm s -1. In this region, performance is most strongly correlated to flow velocity and open circuit voltage. Themore » highest peak power density achieved is 633 mW cm -2 at 833°C, for equivalence ratio of 1.8 and flow velocity of 300 cm s -1. The cell starts to produce power within 10 s of being placed in the flame, and displays stable performance over 10 extremely rapid thermal cycles. The cell provides stable performance for >20 h of semi-continuous operation.« less

Worldwide orthopaedic research activity 2010-2014: Publication rates in the top 15 orthopaedic journals related to population size and gross domestic product

PubMed Central

Hohmann, Erik; Glatt, Vaida; Tetsworth, Kevin

2017-01-01

AIM To perform a bibliometric analysis of publications rates in orthopedics in the top 15 orthopaedic journals. METHODS Based on their 2015 impact factor, the fifteen highest ranked orthopaedic journals between January 2010 and December 2014 were used to establish the total number of publications; cumulative impact factor points (IF) per country were determined, and normalized to population size, GDP, and GDP/capita, comparison to the median country output and the global leader. RESULTS Twenty-three thousand and twenty-one orthopaedic articles were published, with 66 countries publishing. The United States had 8149 publications, followed by the United Kingdom (1644) and Japan (1467). The highest IF was achieved by the United States (24744), United Kingdom (4776), and Japan (4053). Normalized by population size Switzerland lead. Normalized by GDP, Croatia was the top achiever. Adjusting GDP/capita, for publications and IF, China, India, and the United States were the leaders. Adjusting for population size and GDP, 28 countries achieved numbers of publications to be considered at least equivalent with the median academic output. Adjusting GDP/capita only China and India reached the number of publications to be considered equivalent to the current global leader, the United States. CONCLUSION Five countries were responsible for 60% of the orthopaedic research output over this 5-year period. After correcting for GDP/capita, only 28 of 66 countries achieved a publication rate equivalent to the median country. The United States, United Kingdom, South Korea, Japan, and Germany were the top five countries for both publication totals and cumulative impact factor points. PMID:28660144

Characterization of low-frequency acoustic wave propagation through a periodic corrugated waveguide

NASA Astrophysics Data System (ADS)

Jiang, Changyong; Huang, Lixi

2018-03-01

In this paper, a periodic corrugated waveguide structure is proposed, and its unit-cell is analyzed by the wave finite element method. In low-frequency range, the unit-cell is treated as an equivalent fluid through a homogenization process, and the equivalent acoustic parameters are obtained, which are validated by finite structure simulations and experiments. The proposed structure is shown to add tortuosity to the waveguide, hence higher equivalent fluid density is achieved, while the system elastic modulus remains unchanged. As a result, the equivalent speed of sound is smaller than normal air. The application of such change of speed of sound is demonstrated in the classic quarter-wavelength resonator based on the corrugated waveguide, which gives a lower resonance frequency with the same side branch length. When the waveguide is filled with porous materials, the added tortuosity enhances the broadband, low-frequency sound absorption by increasing the equivalent mass without bringing in excess damping, the latter being partly responsible for the poor performance of usual porous materials in the low-frequency region. Therefore, the proposed structure provides another dimension for the design and optimization of porous sound absorption materials.

The neuroanatomy of general intelligence: sex matters.

PubMed

Haier, Richard J; Jung, Rex E; Yeo, Ronald A; Head, Kevin; Alkire, Michael T

2005-03-01

We examined the relationship between structural brain variation and general intelligence using voxel-based morphometric analysis of MRI data in men and women with equivalent IQ scores. Compared to men, women show more white matter and fewer gray matter areas related to intelligence. In men IQ/gray matter correlations are strongest in frontal and parietal lobes (BA 8, 9, 39, 40), whereas the strongest correlations in women are in the frontal lobe (BA10) along with Broca's area. Men and women apparently achieve similar IQ results with different brain regions, suggesting that there is no singular underlying neuroanatomical structure to general intelligence and that different types of brain designs may manifest equivalent intellectual performance.

75 FR 9477 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-02

... concluded that granting these exemption renewals will provide a level of safety that is equivalent to, or... achieve a level of safety that is equivalent to, or greater than, the level that would be achieved absent... conditions of the exemption; (2) the exemption has resulted in a lower level of safety than was maintained...

75 FR 8187 - Qualification of Drivers; Exemption Renewals; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-23

... granting these exemptions will provide a level of safety that will be equivalent to, or greater than, the... achieve a level of safety that is equivalent to, or greater than, the level that would be achieved absent... a lower level of safety than was maintained before it was granted; or (3) continuation of the...

Designing Haptic Assistive Technology for Individuals Who Are Blind or Visually Impaired.

PubMed

Pawluk, Dianne T V; Adams, Richard J; Kitada, Ryo

2015-01-01

This paper considers issues relevant for the design and use of haptic technology for assistive devices for individuals who are blind or visually impaired in some of the major areas of importance: Braille reading, tactile graphics, orientation and mobility. We show that there is a wealth of behavioral research that is highly applicable to assistive technology design. In a few cases, conclusions from behavioral experiments have been directly applied to design with positive results. Differences in brain organization and performance capabilities between individuals who are "early blind" and "late blind" from using the same tactile/haptic accommodations, such as the use of Braille, suggest the importance of training and assessing these groups individually. Practical restrictions on device design, such as performance limitations of the technology and cost, raise questions as to which aspects of these restrictions are truly important to overcome to achieve high performance. In general, this raises the question of what it means to provide functional equivalence as opposed to sensory equivalence.

Understanding Quantum Tunneling through Quantum Monte Carlo Simulations.

PubMed

Isakov, Sergei V; Mazzola, Guglielmo; Smelyanskiy, Vadim N; Jiang, Zhang; Boixo, Sergio; Neven, Hartmut; Troyer, Matthias

2016-10-28

The tunneling between the two ground states of an Ising ferromagnet is a typical example of many-body tunneling processes between two local minima, as they occur during quantum annealing. Performing quantum Monte Carlo (QMC) simulations we find that the QMC tunneling rate displays the same scaling with system size, as the rate of incoherent tunneling. The scaling in both cases is O(Δ^{2}), where Δ is the tunneling splitting (or equivalently the minimum spectral gap). An important consequence is that QMC simulations can be used to predict the performance of a quantum annealer for tunneling through a barrier. Furthermore, by using open instead of periodic boundary conditions in imaginary time, equivalent to a projector QMC algorithm, we obtain a quadratic speedup for QMC simulations, and achieve linear scaling in Δ. We provide a physical understanding of these results and their range of applicability based on an instanton picture.

Single-stage experimental evaluation of compressor blading with slots and vortex generators, part 5

NASA Technical Reports Server (NTRS)

Brent, J. A.

1972-01-01

An experimental investigation was conducted to determine the extent that slots and vortex generators can increase the efficiency and stable operating range of highly loaded compressor stages. With slots in the rotor and stator, the stage performance both with and without vortex generators was inferior to that achieved with the unslotted blading. However, with vortex generators, stator slots, and an unslotted rotor, the stable operating range increased 25% and the stage peak efficiency increased 2.1% over the values achieved with the unslotted rotor and stator without vortex generators, at design equivalent rotor speed.

Caloric restriction and spatial learning in old mice.

PubMed

Bellush, L L; Wright, A M; Walker, J P; Kopchick, J; Colvin, R A

1996-08-01

Spatial learning in old mice (19 or 24 months old), some of which had been calorically restricted beginning at 14 weeks of age, was compared to that of young mice, in two separate experiments using a Morris water maze. In the first experiment, only old mice reaching criterion performance on a cued learning task were tested in a subsequent spatial task. Thus, all old mice tested for spatial learning had achieved escape latencies equivalent to those of young controls. Despite equivalent swimming speeds, only about half the old mice in each diet group achieved criterion performance in the spatial task. In the second experiment, old and young mice all received the same number of training trials in a cued task and then in a spatial task. Immediately following spatial training, they were given a 60-s probe trial, with no platform in the pool. Both groups of old mice spent significantly less time in the quadrant where the platform had been and made significantly fewer direct crosses over the previous platform location than did the young control group. As in Experiment 1, calorie restriction failed to provide protection against aging-related deficits. However, in both experiments, some individual old mice evidenced performance in spatial learning indistinguishable from that of young controls. Separate comparisons of "age-impaired" and "age-unimpaired" old mice with young controls may facilitate the identification of neurobiological mechanisms underlying age-related cognitive decline.

77 FR 60010 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-01

... exemption renewals will provide a level of safety that is equivalent to or greater than the level of safety... achieve a level of safety that is equivalent to or greater than the level that would be achieved absent... comply with the terms and conditions of the exemption; (2) the exemption has resulted in a lower level of...

78 FR 24298 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-24

... granting these exemption renewals will provide a level of safety that is equivalent to or greater than the... achieve a level of safety that is equivalent to or greater than the level that would be achieved absent... conditions of the exemption; (2) the exemption has resulted in a lower level of safety than was maintained...

A comparison of foveated acquisition and tracking performance relative to uniform resolution approaches

NASA Astrophysics Data System (ADS)

Dubuque, Shaun; Coffman, Thayne; McCarley, Paul; Bovik, A. C.; Thomas, C. William

2009-05-01

Foveated imaging has been explored for compression and tele-presence, but gaps exist in the study of foveated imaging applied to acquisition and tracking systems. Results are presented from two sets of experiments comparing simple foveated and uniform resolution targeting (acquisition and tracking) algorithms. The first experiments measure acquisition performance when locating Gabor wavelet targets in noise, with fovea placement driven by a mutual information measure. The foveated approach is shown to have lower detection delay than a notional uniform resolution approach when using video that consumes equivalent bandwidth. The second experiments compare the accuracy of target position estimates from foveated and uniform resolution tracking algorithms. A technique is developed to select foveation parameters that minimize error in Kalman filter state estimates. Foveated tracking is shown to consistently outperform uniform resolution tracking on an abstract multiple target task when using video that consumes equivalent bandwidth. Performance is also compared to uniform resolution processing without bandwidth limitations. In both experiments, superior performance is achieved at a given bandwidth by foveated processing because limited resources are allocated intelligently to maximize operational performance. These findings indicate the potential for operational performance improvements over uniform resolution systems in both acquisition and tracking tasks.

HIFiRE Direct-Connect Rig (HDCR) Phase I Scramjet Test Results from the NASA Langley Arc-Heated Scramjet Test Facility

NASA Technical Reports Server (NTRS)

Cabell, Karen; Hass, Neal; Storch, Andrea; Gruber, Mark

2011-01-01

A series of hydrocarbon-fueled direct-connect scramjet ground tests has been completed in the NASA Langley Arc-Heated Scramjet Test Facility (AHSTF) at simulated Mach 8 flight conditions. These experiments were part of an initial test phase to support Flight 2 of the Hypersonic International Flight Research Experimentation (HIFiRE) Program. In this flight experiment, a hydrocarbon-fueled scramjet is intended to demonstrate transition from dual-mode to scramjet-mode operation and verify the scramjet performance prediction and design tools A performance goal is the achievement of a combusted fuel equivalence ratio greater than 0.7 while in scramjet mode. The ground test rig, designated the HIFiRE Direct Connect Rig (HDCR), is a full-scale, heat sink test article that duplicates both the flowpath lines and a majority of the instrumentation layout of the isolator and combustor portion of the flight test hardware. The primary objectives of the HDCR Phase I tests were to verify the operability of the HIFiRE isolator/combustor across the simulated Mach 6-8 flight regime and to establish a fuel distribution schedule to ensure a successful mode transition. Both of these objectives were achieved prior to the HiFIRE Flight 2 payload Critical Design Review. Mach 8 ground test results are presented in this report, including flowpath surface pressure distributions that demonstrate the operation of the flowpath in scramjet-mode over a small range of test conditions around the nominal Mach 8 simulation, as well as over a range of fuel equivalence ratios. Flowpath analysis using ground test data is presented elsewhere; however, limited comparisons with analytical predictions suggest that both scramjet-mode operation and the combustion performance objective are achieved at Mach 8 conditions.

Design and performance of a SWaP short-range fully fibered monostatic laser rangefinder

NASA Astrophysics Data System (ADS)

Pallier, G.; Portalis, A.; Canat, G.; Chiquet, F.; Auffray, P.; Le, S.-D.; Le Flohic, M.

2017-10-01

The development of a multisensor optronic device requires Size, Weight and Power (SWaP), cost-effective and modular rangefinders while keeping a good range performance. We report on a fully fibered monostatic laser rangerfinder based on a one lens collimator used as the aperture of both the emission and reception channels. This has been possible thanks to the use of a diplexer. This design makes the system compacter and achieves a 200g system weight. In addition to its low volume, the fully fibered architecture allows designing a building block rangefinder with the collimator sub-system on one side and the laser and electronics cards module on the other side. Both are linked up by only an optical fiber. This kit format enables the rangefinder to better fit in any available space in higher level systems such as gimbals and multi-function imagers. Besides, no alignment is needed, and no parallax error is possible: the alignment between channels is guaranteed by design over the whole range. The emission/reception channels of the first prototype has a 28mm diameter 80mm focal length lens, and a 1.55μm 100μJ pulsed laser firing in a burst mode. The rangefinder is set in a class 1 configuration, and measures at 1Hz. The achieved Extinction Ratio is 30dB, which is equivalent to a range on NATO targets of 7km. The achieved ER being class 1M at 5Hz is even 32dB, which is equivalent to a range of 8.5km on NATO targets. More configurations are reported in this article with their associated performance.

Language Measurement Equivalence of the Ethnic Identity Scale With Mexican American Early Adolescents

PubMed Central

White, Rebecca M. B.; Umaña-Taylor, Adriana J.; Knight, George P.; Zeiders, Katharine H.

2011-01-01

The current study considers methodological challenges in developmental research with linguistically diverse samples of young adolescents. By empirically examining the cross-language measurement equivalence of a measure assessing three components of ethnic identity development (i.e., exploration, resolution, and affirmation) among Mexican American adolescents, the study both assesses the cross-language measurement equivalence of a common measure of ethnic identity and provides an appropriate conceptual and analytical model for researchers needing to evaluate measurement scales translated into multiple languages. Participants are 678 Mexican-origin early adolescents and their mothers. Measures of exploration and resolution achieve the highest levels of equivalence across language versions. The measure of affirmation achieves high levels of equivalence. Results highlight potential ways to correct for any problems of nonequivalence across language versions of the affirmation measure. Suggestions are made for how researchers working with linguistically diverse samples can use the highlighted techniques to evaluate their own translated measures. PMID:22116736

78 FR 50139 - Commercial Driver's License Standards: Application for Exemption; Miami Nice Tours

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-16

... non-residents. Miami believes that these drivers are likely to achieve a level of safety that is equivalent to or greater than the level of safety that would be obtained if they held U.S. CDLs. DATES... level of safety equivalent to or greater than the level that would be achieved by the current regulation...

USAR Recruiting Success Factors.

DTIC Science & Technology

1987-12-01

scores, were used to predict production scores for each recruiter. Benchmark Achievement Scores (BAS) were computed by dividing total production bv...performance compnred to thil avigle would b ,’asl,_cr t.o compute . SAS correlated high y witi IIAS r .96 . so tihe two scores were practically equivalent...asked to make a sales pitch to a prospective enlistee about the benefits of Army life. Presen- tations were scored by computing the ratio of the

40 CFR 63.41 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... existing equipment will be equivalent to that level of control currently achieved by other well-controlled similar sources (i.e., equivalent to the level of control that would be provided by a current BACT, LAER... control equipment will be equivalent to the percent control efficiency provided by the control equipment...

40 CFR 63.41 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... existing equipment will be equivalent to that level of control currently achieved by other well-controlled similar sources (i.e., equivalent to the level of control that would be provided by a current BACT, LAER... control equipment will be equivalent to the percent control efficiency provided by the control equipment...

40 CFR 63.41 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... existing equipment will be equivalent to that level of control currently achieved by other well-controlled similar sources (i.e., equivalent to the level of control that would be provided by a current BACT, LAER... control equipment will be equivalent to the percent control efficiency provided by the control equipment...

40 CFR 63.41 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... existing equipment will be equivalent to that level of control currently achieved by other well-controlled similar sources (i.e., equivalent to the level of control that would be provided by a current BACT, LAER... control equipment will be equivalent to the percent control efficiency provided by the control equipment...

40 CFR 63.41 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... existing equipment will be equivalent to that level of control currently achieved by other well-controlled similar sources (i.e., equivalent to the level of control that would be provided by a current BACT, LAER... control equipment will be equivalent to the percent control efficiency provided by the control equipment...

Solution-Processed Cu2Se Nanocrystal Films with Bulk-Like Thermoelectric Performance.

PubMed

Forster, Jason D; Lynch, Jared J; Coates, Nelson E; Liu, Jun; Jang, Hyejin; Zaia, Edmond; Gordon, Madeleine P; Szybowski, Maxime; Sahu, Ayaskanta; Cahill, David G; Urban, Jeffrey J

2017-06-05

Thermoelectric power generation can play a key role in a sustainable energy future by converting waste heat from power plants and other industrial processes into usable electrical power. Current thermoelectric devices, however, require energy intensive manufacturing processes such as alloying and spark plasma sintering. Here, we describe the fabrication of a p-type thermoelectric material, copper selenide (Cu 2 Se), utilizing solution-processing and thermal annealing to produce a thin film that achieves a figure of merit, ZT, which is as high as its traditionally processed counterpart, a value of 0.14 at room temperature. This is the first report of a fully solution-processed nanomaterial achieving performance equivalent to its bulk form and represents a general strategy to reduce the energy required to manufacture advanced energy conversion and harvesting materials.

The effects of active (hot-seat) versus observer roles during simulation-based training on stress levels and non-technical performance: a randomized trial.

PubMed

Bong, Choon Looi; Lee, Sumin; Ng, Agnes Suah Bwee; Allen, John Carson; Lim, Evangeline Hua Ling; Vidyarthi, Arpana

2017-01-01

Active 'hands-on' participation in the 'hot-seat' during immersive simulation-based training (SBT) induces stress for participants, which is believed to be necessary to improve performance. We hypothesized that observers of SBT can subsequently achieve an equivalent level of non-technical performance as 'hot-seat' participants despite experiencing lower stress. We randomized 37 anaesthesia trainees into two groups to undergo three consecutive SBT scenarios. Eighteen 'hot-seat' trainees actively participated in all three scenarios, and 19 'observer' trainees were directed to observe the first two scenarios and participated in the 'hot-seat' only in scenario 3. Salivary cortisol (SC) was measured at four time points during each scenario. Primary endpoint for stress response was the change in SC (ΔSC) from baseline. Performance was measured using the Anaesthetist's Non-Technical Skills (ANTS) Score. Mean SC increased in all participants whenever they were in the 'hot-seat' role, but not when in the observer role. Hot-seat ΔSC (mcg/dL) for scenarios 1, 2, and 3 were 0.122 ( p  = 0.001), 0.074 ( p  = 0.047), and 0.085 ( p  = 0.023), respectively. Observers ΔSC (mcg/dL) for scenarios 1, 2, and 3 were -0.062 ( p  = 0.091), 0.010 ( p  = 0.780), and 0.144 ( p  = 0.001), respectively. Mean ANTS scores were equivalent between the 'hot-seat' (40.0) and 'observer' (39.4) groups in scenario 3 ( p  = 0.733). Observers of SBT achieved an equivalent level of non-technical performance, while experiencing lower stress than trainees repeatedly trained in the 'hot-seat'. Our findings suggest that directed observers may benefit from immersive SBT even without repeated 'hands-on' experience and stress in the hot-seat. The directed observer role may offer a less stressful, practical alternative to the traditional 'hot-seat' role, potentially rendering SBT accessible to a wider audience. ClinicalTrials.gov Identifier NCT02211378, registered August 5, 2014, retrospectively registered.

The impact of attaining the Welsh Baccalaureate Advanced Diploma on academic performance in bioscience higher education

NASA Astrophysics Data System (ADS)

Yhnell, Emma; Wood, Heather; Baker, Mathew; Amici-Dargan, Sheila; Taylor, Chris; Randerson, Peter; Shore, Andrew

2016-01-01

Since the introduction of the Welsh Baccalaureate Advanced Diploma Qualification (WBQ) in 2003, an increasing number of students are applying to higher education institutions (HEIs) with this qualification. The advanced-level WBQ is regarded as equivalent to one General Certificate of Education A-Level (GCE A-Level). This study assesses the impact of attaining the WBQ in addition to three GCE A-Levels on overall university degree performance in comparison to attaining four GCE A-Levels, in three cohorts of undergraduate students (Year 1 = 318, Year 2 = 280, Year 3 = 236) studying Biosciences from 2005 to 2011 at a UK HEI. Binary logistic regression was used to compare the academic attainment of students who had achieved four GCE A-Levels to those who had achieved three GCE A-Levels in addition to the WBQ. Comparisons were also made between students who had achieved three GCE A-Levels and those who had achieved three GCE A-Levels in addition to the WBQ. The results suggest that students who achieved the WBQ qualification in its current form, in addition to three GCE A-Levels, performed less well academically in undergraduate studies than those who achieved four GCE A-Levels. Furthermore, this effect was still present when the balance between coursework and examination was considered, and when students who had achieved the WBQ in addition to three GCE A-Levels were compared to students who had achieved three GCE A-Levels.

Comparisons of Internet-Based and Face-to-Face Learning Systems Based on "Equivalency of Experiences" According to Students' Academic Achievements and Satisfactions

ERIC Educational Resources Information Center

Karatas, Sercin; Simsek, Nurettin

2009-01-01

The purpose of this study is to determine whether "equivalent learning experiences" ensure equivalency, in the Internet-based and face-to-face interaction methods on learning results and student satisfaction. In the experimental process of this study, the effect of the Internet-based and face-to-face learning on the equivalency in…

40 CFR 63.55 - Maximum achievable control technology (MACT) determinations for affected sources subject to case...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (MACT) determinations for affected sources subject to case-by-case determination of equivalent emission... sources subject to case-by-case determination of equivalent emission limitations. (a) Requirements for... hazardous air pollutant emissions limitations equivalent to the limitations that would apply if an emission...

Reducing operator radiation exposure during cardiac resynchronization therapy.

PubMed

Brambilla, Marco; Occhetta, Eraldo; Ronconi, Martina; Plebani, Laura; Carriero, Alessandro; Marino, Paolo

2010-12-01

To quantify the reduction in equivalent dose at operator's hand that can be achieved by placement of a radiation-absorbing drape (RADPAD) during long-lasting cardiac resynchronization therapy (CRT) procedures. This is a prospective observational study that included 22 consecutive patients with drug-refractory heart failure who underwent implantation of a CRT device. The cases were randomly assigned to Group A (11 cases), performed without RADPAD, and to Group B (11 cases), performed using RADPAD. Dose equivalent at the examiner's hand was measured as H(p)(0.07) and as a time-adjusted H(p)(0.07) rate (mGy/min) with a direct reading dosimeter. The mean fluoroscopy time was 20.8 ± 7.7 min and the mean dose area product (DAP) was 118.6 ± 45.3 Gy cm(2). No significant differences were found between body mass index, fluoroscopy time, and DAP between patients examined with or without RADPAD. The correlation between the fluoroscopy time and the DAP was high (R(2) = 0.94, P < 0.001). Mean dose and dose rate measurement without the RADPAD at the finger and hand were H(p)(0.07) = 1.27 ± 0.47 mGy per procedure and H(p)(0.07) rate = 0.057 ± 0.011 mGy/min, respectively. The dosage was reduced with the RADPAD to H(p)(0.07) = 0.48 ± 0.20 (P < 0.05) and to H(p)(0.07) rate = 0.026 ± 0.008 (P < 0.001), respectively. A mean reduction of 54% in the equivalent dose rate to the operator's hand can be achieved with the use of RADPAD. The use of the RADPAD in CRT devices implantation will make unlikely the necessity of limiting the yearly number of implants for high volume operators.

Public Higher Education Performance Accountability Framework Report: Goal--Access and Affordability. Measure: Percentage of Racial Representation in Systems of Higher Education Compared to Racial Representation in the State. Commission Report 07-20

ERIC Educational Resources Information Center

California Postsecondary Education Commission, 2007

2007-01-01

Despite segmental efforts to increase diversity in higher education, African American and Latino students are not achieving levels of representation in California public universities that are equivalent to their levels of representation in the overall State population. Using data for the years 1997 through 2006, the California Postsecondary…

STEP: Satellite Test of the Equivalence Principle. Report on the phase A study

NASA Technical Reports Server (NTRS)

Blaser, J. P.; Bye, M.; Cavallo, G.; Damour, T.; Everitt, C. W. F.; Hedin, A.; Hellings, R. W.; Jafry, Y.; Laurance, R.; Lee, M.

1993-01-01

During Phase A, the STEP Study Team identified three types of experiments that can be accommodated on the STEP satellite within the mission constraints and whose performance is orders of magnitude better than any present or planned future experiment of the same kind on the ground. The scientific objectives of the STEP mission are to: test the Equivalence Principle to one part in 10(exp 17), six orders of magnitude better than has been achieved on the ground; search for a new interaction between quantum-mechanical spin and ordinary matter with a sensitivity of the mass-spin coupling constant g(sub p)g(sub s) = 6 x 10(exp -34) at a range of 1 mm, which represents a seven order-of-magnitude improvement over comparable ground-based measurements; and determine the constant of gravity G with a precision of one part in 10(exp 6) and to test the validity of the inverse square law with the same precision, both two orders of magnitude better than has been achieved on the ground.

A polymeric sealant inhibits anastomotic suture hole bleeding more rapidly than gelfoam/thrombin: results of a randomized controlled trial.

PubMed

Glickman, Marc; Gheissari, Ali; Money, Samuel; Martin, John; Ballard, Jeffrey L

2002-03-01

An experimental polymeric sealant (CoSeal [Cohesion Technologies, Palo Alto, Calif]) provides equivalent anastomotic sealing to Gelfoam (Upjohn, Kalamazoo, Mich)/thrombin during surgical placement of prosthetic vascular grafts. Randomized controlled trial. Nine university-affiliated medical centers. One hundred forty-eight patients scheduled for implantation of polytetrafluoroethylene grafts, mainly for infrainguinal revascularization procedures or the creation of dialysis access shunts, who were treated randomly with either an experimental intervention (n = 74) or control (n = 74). Following polytetrafluoroethylene graft placement, anastomotic suture hole bleeding was treated intraoperatively in all control subjects with Gelfoam/thrombin. Subjects in the experimental group had the polymeric sealant applied directly to the suture lines without concomitant manual compression. Primary treatment success was defined as the proportion of subjects in each group that achieved complete anastomotic sealing within 10 minutes. The proportion of subjects that achieved immediate sealing and the time required to fully inhibit suture hole bleeding also were compared between treatment groups. Overall 10-minute sealing success was equivalent (86% vs 80%; P =.29) between experimental and control subjects, respectively. However, subjects treated with CoSeal achieved immediate anastomotic sealing at more than twice the rate of subjects treated with Gelfoam/thrombin (47% vs 20%; P<.001). Consequently, the median time needed to inhibit bleeding in control subjects was more than 10 times longer than for experimental subjects (16.5 seconds vs 189.0 seconds; P =.01). Strikingly similar findings for all comparisons were observed separately for subgroups of subjects having infrainguinal bypass grafting and for those undergoing placement of dialysis access shunts. The experimental sealant offers equivalent anastomotic sealing performance compared with Gelfoam/thrombin, but it provides this desired effect in a significantly more rapid time frame.

Solution-Processed Cu 2Se Nanocrystal Films with Bulk-Like Thermoelectric Performance

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

Forster, Jason D.; Lynch, Jared J.; Coates, Nelson E.

Thermoelectric power generation can play a key role in a sustainable energy future by converting waste heat from power plants and other industrial processes into usable electrical power. Current thermoelectric devices, however, require energy intensive manufacturing processes such as alloying and spark plasma sintering. Here, we describe the fabrication of a p-type thermoelectric material, copper selenide (Cu 2 Se), utilizing solution-processing and thermal annealing to produce a thin film that achieves a figure of merit, ZT, which is as high as its traditionally processed counterpart, a value of 0.14 at room temperature. This is the first report of amore » fully solution-processed nanomaterial achieving performance equivalent to its bulk form and represents a general strategy to reduce the energy required to manufacture advanced energy conversion and harvesting materials.« less

Inflated Applicants: Attribution Errors in Performance Evaluation by Professionals

PubMed Central

Swift, Samuel A.; Moore, Don A.; Sharek, Zachariah S.; Gino, Francesca

2013-01-01

When explaining others' behaviors, achievements, and failures, it is common for people to attribute too much influence to disposition and too little influence to structural and situational factors. We examine whether this tendency leads even experienced professionals to make systematic mistakes in their selection decisions, favoring alumni from academic institutions with high grade distributions and employees from forgiving business environments. We find that candidates benefiting from favorable situations are more likely to be admitted and promoted than their equivalently skilled peers. The results suggest that decision-makers take high nominal performance as evidence of high ability and do not discount it by the ease with which it was achieved. These results clarify our understanding of the correspondence bias using evidence from both archival studies and experiments with experienced professionals. We discuss implications for both admissions and personnel selection practices. PMID:23894437

Solution-Processed Cu 2Se Nanocrystal Films with Bulk-Like Thermoelectric Performance

DOE PAGES

Forster, Jason D.; Lynch, Jared J.; Coates, Nelson E.; ...

2017-06-05

Thermoelectric power generation can play a key role in a sustainable energy future by converting waste heat from power plants and other industrial processes into usable electrical power. Current thermoelectric devices, however, require energy intensive manufacturing processes such as alloying and spark plasma sintering. Here, we describe the fabrication of a p-type thermoelectric material, copper selenide (Cu 2 Se), utilizing solution-processing and thermal annealing to produce a thin film that achieves a figure of merit, ZT, which is as high as its traditionally processed counterpart, a value of 0.14 at room temperature. This is the first report of amore » fully solution-processed nanomaterial achieving performance equivalent to its bulk form and represents a general strategy to reduce the energy required to manufacture advanced energy conversion and harvesting materials.« less

ARES v2: new features and improved performance

NASA Astrophysics Data System (ADS)

Sousa, S. G.; Santos, N. C.; Adibekyan, V.; Delgado-Mena, E.; Israelian, G.

2015-05-01

Aims: We present a new upgraded version of ARES. The new version includes a series of interesting new features such as automatic radial velocity correction, a fully automatic continuum determination, and an estimation of the errors for the equivalent widths. Methods: The automatic correction of the radial velocity is achieved with a simple cross-correlation function, and the automatic continuum determination, as well as the estimation of the errors, relies on a new approach to evaluating the spectral noise at the continuum level. Results: ARES v2 is totally compatible with its predecessor. We show that the fully automatic continuum determination is consistent with the previous methods applied for this task. It also presents a significant improvement on its performance thanks to the implementation of a parallel computation using the OpenMP library. Automatic Routine for line Equivalent widths in stellar Spectra - ARES webpage: http://www.astro.up.pt/~sousasag/ares/Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 075.D-0800(A).

Cross cultural translation and adaptation to Brazilian Portuguese of the Hearing Implant Sound Quality Index Questionnaire - (HISQUI19).

PubMed

Caporali, Priscila Faissola; Caporali, Sueli Aparecida; Bucuvic, Érika Cristina; Vieira, Sheila de Souza; Santos, Zeila Maria; Chiari, Brasília Maria

2016-01-01

Translation and cross-cultural adaptation of the instrument Hearing Implant Sound Quality Index (HISQUI19), and characterization of the target population and auditory performance in Cochlear Implant (CI) users through the application of a synthesis version of this tool. Evaluations of conceptual, item, semantic and operational equivalences were performed. The synthesis version was applied as a pre-test to 33 individuals, whose final results characterized the final sample and performance of the questionnaire. The results were analyzed statistically. The final translation (FT) was back-translated and compared with the original version, revealing a minimum difference between items. The changes observed between the FT and the synthesis version were characterized by the application of simplified vocabulary used on a daily basis. For the pre-test, the average score of the interviewees was 90.2, and a high level of reliability was achieved (0.83). The translation and cross-cultural adaptation of the HISQUI19 questionnaire showed suitability for conceptual, item, semantic and operational equivalences. For the sample characterization, the sound quality was classified as good with better performance for the categories of location and distinction of sound/voices.

Applicability of the lattice Boltzmann method to determine the ohmic resistance in equivalent resistor connections

NASA Astrophysics Data System (ADS)

Espinoza-Andaluz, Mayken; Barzola, Julio; Guarochico-Moreira, Víctor H.; Andersson, Martin

2017-12-01

Knowing the ohmic resistance in the materials allow to know in advance its electrical behavior when a potential difference is applied, and therefore the prediction of the electrical performance can be achieved in a most certain manner. Although the Lattice Boltzmann method (LBM) has been applied to solve several physical phenomena in complex geometries, it has only been used to describe the fluid phase, but applicability studies of LBM on the solid-electric-conducting material have not been carried out yet. The purpose of this paper is to demonstrate the accuracy of calculating the equivalent resistor connections using LBM. Several series and parallel resistor connections are effected. All the computations are carried out with 3D models, and the domain materials are designed by the authors.

Equivalent Safety Basis for Evaluation of On-Site Packages for US DOE Facilities

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

Smith, A.C.

Packages for transport of radioactive material within the boundaries of a Department of Energy facility (on-site) must conform to the requirements for packages shipped in normal commerce, or must provide equivalent safety. Equivalence is achieved if the frequency of severe on-site accidents, which could result in a release of radioactive material, is less than or equal to the frequency of Beyond-HAC accidents for packages in commerce. This is shown to be achieved it the rate of on-site accident is 22 per 100 MVM or lower. For equivalence to Normal Conditions of Transport, for on-site packages, appropriate, defensible Design Basis Conditionsmore » can be established and the ability of the package to meet the reduced requirements shown in the On-site Safety Assessment.« less

Refractive errors and refractive development in premature infants.

PubMed

Ozdemir, O; Tunay, Z Ozen; Acar, D Erginturk; Acar, U

2015-12-01

To examine refractive errors and refractive development in premature infants. Premature infants in the retinopathy of prematurity (ROP) screening program were recruited and examined longitudinally between 28 and 58 weeks postmenstrual age. For performing cycloplegic retinoscopy, 1% tropicamide was administered, two drops with a 10-minute interval, in order to paralyze accommodation and to achieve cycloplegia. Birth weight, gestational age, gender and acute ROP disease were recorded. The relationship between spherical equivalent, astigmatism and postmenstrual age was evaluated. A total of 798 readings were obtained from 258 infants (131 females, 127 males) between 28 and 58 weeks postmenstrual age. The median number of examinations was 3 (minimum 1, maximum 7). In the comparisons of birth weight, gestational age, spherical equivalent and astigmatism between genders, there were no statistically significant differences (P>0.05). Gestational age (regression analysis, r(2)=0.30, P<0.01) and birth weight (regression analysis, r(2)=0.22, P<0.01) had a significant effect on refractive error development. Preterm babies with lower birth weight and those born more prematurely had lower spherical equivalent. The spherical equivalent of the eyes correlated significantly with the postmenstrual age of the infants (r=0.512, P<0.01). Infants with low gestational age and low birth weight also had low spherical equivalent. Moreover, spherical equivalent correlated with increasing postmenstrual age. However, astigmatism did not correlate with postmenstrual age and did not associate with gestational age or birth weight. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Performance of generation III 640 X 480 PtSi MOS array

NASA Astrophysics Data System (ADS)

Villani, Thomas S.; Esposito, Benjamin J.; Pletcher, T. J.; Sauer, Donald J.; Levine, Peter A.; Shallcross, Frank V.; Meray, Grazyna M.; Tower, John R.

1994-07-01

The design and performance of a third generation 640(H) X 480(V) PtSi focal plane array is presented. The 3 to 5 micron MWIR focal plane array supports interlaced, progressive scan, and subframe readout under control of on-chip digital decoders. The new design utilizes 1.25 micrometers design rules to achieve a 50% fill-factor, a noise equivalent delta temperature of <0.07 C (f/1.5, 30 Hz, 300 K), and a saturation level >1.5 X 10(superscript 6)e. The power dissipation is less than 110 mW.

Using Strassen's algorithm to accelerate the solution of linear systems

NASA Technical Reports Server (NTRS)

Bailey, David H.; Lee, King; Simon, Horst D.

1990-01-01

Strassen's algorithm for fast matrix-matrix multiplication has been implemented for matrices of arbitrary shapes on the CRAY-2 and CRAY Y-MP supercomputers. Several techniques have been used to reduce the scratch space requirement for this algorithm while simultaneously preserving a high level of performance. When the resulting Strassen-based matrix multiply routine is combined with some routines from the new LAPACK library, LU decomposition can be performed with rates significantly higher than those achieved by conventional means. We succeeded in factoring a 2048 x 2048 matrix on the CRAY Y-MP at a rate equivalent to 325 MFLOPS.

Defining Equivalence in Medical Education Evaluation and Research: Does a Distribution-Based Approach Work?

ERIC Educational Resources Information Center

Rusticus, Shayna A.; Eva, Kevin W.

2016-01-01

Educators often seek to demonstrate the equivalence of groups, such as whether or not students achieve comparable success regardless of the site at which they trained. A methodological consideration that is often underappreciated is how to operationalize equivalence. This study examined whether a distribution-based approach, based on effect size,…

Midfield wireless powering of subwavelength autonomous devices.

PubMed

Kim, Sanghoek; Ho, John S; Poon, Ada S Y

2013-05-17

We obtain an analytical bound on the efficiency of wireless power transfer to a weakly coupled device. The optimal source is solved for a multilayer geometry in terms of a representation based on the field equivalence principle. The theory reveals that optimal power transfer exploits the properties of the midfield to achieve efficiencies far greater than conventional coil-based designs. As a physical realization of the source, we present a slot array structure whose performance closely approaches the theoretical bound.

Cross-cultural equivalence of the patient- and parent-reported quality of life in short stature youth (QoLISSY) questionnaire.

PubMed

Bullinger, Monika; Quitmann, Julia; Silva, Neuza; Rohenkohl, Anja; Chaplin, John E; DeBusk, Kendra; Mimoun, Emmanuelle; Feigerlova, Eva; Herdman, Michael; Sanz, Dolores; Wollmann, Hartmut; Pleil, Andreas; Power, Michael

2014-01-01

Testing cross-cultural equivalence of patient-reported outcomes requires sufficiently large samples per country, which is difficult to achieve in rare endocrine paediatric conditions. We describe a novel approach to cross-cultural testing of the Quality of Life in Short Stature Youth (QoLISSY) questionnaire in five countries by sequentially taking one country out (TOCO) from the total sample and iteratively comparing the resulting psychometric performance. Development of the QoLISSY proceeded from focus group discussions through pilot testing to field testing in 268 short-statured patients and their parents. To explore cross-cultural equivalence, the iterative TOCO technique was used to examine and compare the validity, reliability, and convergence of patient and parent responses on QoLISSY in the field test dataset, and to predict QoLISSY scores from clinical, socio-demographic and psychosocial variables. Validity and reliability indicators were satisfactory for each sample after iteratively omitting one country. Comparisons with the total sample revealed cross-cultural equivalence in internal consistency and construct validity for patients and parents, high inter-rater agreement and a substantial proportion of QoLISSY variance explained by predictors. The TOCO technique is a powerful method to overcome problems of country-specific testing of patient-reported outcome instruments. It provides an empirical support to QoLISSY's cross-cultural equivalence and is recommended for future research.

Developing a hybrid dictionary-based bio-entity recognition technique.

PubMed

Song, Min; Yu, Hwanjo; Han, Wook-Shin

2015-01-01

Bio-entity extraction is a pivotal component for information extraction from biomedical literature. The dictionary-based bio-entity extraction is the first generation of Named Entity Recognition (NER) techniques. This paper presents a hybrid dictionary-based bio-entity extraction technique. The approach expands the bio-entity dictionary by combining different data sources and improves the recall rate through the shortest path edit distance algorithm. In addition, the proposed technique adopts text mining techniques in the merging stage of similar entities such as Part of Speech (POS) expansion, stemming, and the exploitation of the contextual cues to further improve the performance. The experimental results show that the proposed technique achieves the best or at least equivalent performance among compared techniques, GENIA, MESH, UMLS, and combinations of these three resources in F-measure. The results imply that the performance of dictionary-based extraction techniques is largely influenced by information resources used to build the dictionary. In addition, the edit distance algorithm shows steady performance with three different dictionaries in precision whereas the context-only technique achieves a high-end performance with three difference dictionaries in recall.

Developing a hybrid dictionary-based bio-entity recognition technique

PubMed Central

2015-01-01

Background Bio-entity extraction is a pivotal component for information extraction from biomedical literature. The dictionary-based bio-entity extraction is the first generation of Named Entity Recognition (NER) techniques. Methods This paper presents a hybrid dictionary-based bio-entity extraction technique. The approach expands the bio-entity dictionary by combining different data sources and improves the recall rate through the shortest path edit distance algorithm. In addition, the proposed technique adopts text mining techniques in the merging stage of similar entities such as Part of Speech (POS) expansion, stemming, and the exploitation of the contextual cues to further improve the performance. Results The experimental results show that the proposed technique achieves the best or at least equivalent performance among compared techniques, GENIA, MESH, UMLS, and combinations of these three resources in F-measure. Conclusions The results imply that the performance of dictionary-based extraction techniques is largely influenced by information resources used to build the dictionary. In addition, the edit distance algorithm shows steady performance with three different dictionaries in precision whereas the context-only technique achieves a high-end performance with three difference dictionaries in recall. PMID:26043907

Five-way smoking status classification using text hot-spot identification and error-correcting output codes.

PubMed

Cohen, Aaron M

2008-01-01

We participated in the i2b2 smoking status classification challenge task. The purpose of this task was to evaluate the ability of systems to automatically identify patient smoking status from discharge summaries. Our submission included several techniques that we compared and studied, including hot-spot identification, zero-vector filtering, inverse class frequency weighting, error-correcting output codes, and post-processing rules. We evaluated our approaches using the same methods as the i2b2 task organizers, using micro- and macro-averaged F1 as the primary performance metric. Our best performing system achieved a micro-F1 of 0.9000 on the test collection, equivalent to the best performing system submitted to the i2b2 challenge. Hot-spot identification, zero-vector filtering, classifier weighting, and error correcting output coding contributed additively to increased performance, with hot-spot identification having by far the largest positive effect. High performance on automatic identification of patient smoking status from discharge summaries is achievable with the efficient and straightforward machine learning techniques studied here.

Techniques for enhancing durability and equivalence ratio control in a rich-lean, three-stage ground power gas turbine combustor

NASA Technical Reports Server (NTRS)

Schultz, D. F.

1982-01-01

Rig tests of a can-type combustor were performed to demonstrate two advanced ground power engine combustor concepts: steam cooled rich-burn combustor primary zones for enhanced durability; and variable combustor geometry for three stage combustion equivalence ratio control. Both concepts proved to be highly successful in achieving their desired objectives. The steam cooling reduced peak liner temperatures to less than 800 K. This offers the potential of both long life and reduced use of strategic materials for liner fabrication. Three degrees of variable geometry were successfully implemented to control airflow distribution within the combustor. One was a variable blade angle axial flow air swirler to control primary airflow while the other two consisted of rotating bands to control secondary and tertiary or dilution air flow.

Coal fly ash and lime addition enhances the rate and efficiency of decomposition of food waste during composting.

PubMed

Wong, Jonathan W-C; Fung, Shun On; Selvam, Ammaiyappan

2009-07-01

To evaluate the use of coal fly ash (CFA) on the decomposition efficiency of food waste, synthetic food waste was mixed with lime at 1.5% and 3% (equivalent to 0.94% and 1.88% CaCO(3), respectively), CFA at 5%, 10% and 15% with lime so as to achieve CaCO(3) equivalent of 1.88% and composted for 42 days in a thermophilic 20 l composter with two replicates each. Alkaline materials at 1.88% CaCO(3) equivalent successfully buffered the pH during the composting and enhanced the decomposition efficiency. When these buffering was achieved with CFA+lime, the composting period could be shortened to approximately 28 days compared with approximately 42 days in 3% lime. Organic decomposition in terms of CO(2) loss, carbon turnover and nitrogen transformation were significantly higher for treatments with 1.88% CaCO(3) equivalent. Nutrient transformations and compost maturity parameters indicated that addition of CFA (5-10%) with lime at 1.88% CaCO(3) equivalent enhances the decomposition efficiency and shortens the composting period by 35%.

Spirituality, Religiousness, and Alcoholism Treatment Outcomes: A Comparison between Black and White Participants

PubMed Central

Krentzman, Amy R.; Farkas, Kathleen J.; Townsend, Aloen L.

2012-01-01

This study addresses an unexplained finding in the alcoholism treatment field: despite the health and socioeconomic disparities that exist between blacks and whites at intake, blacks and whites achieve equivalent treatment outcomes. Using Project MATCH data, this study explores religiousness and spirituality as strengths in the African American community that may account in part for equivalent outcomes. Using binary logistic regression, this study found that as purpose in life increased, blacks were more likely to achieve sobriety than whites. This study provides evidence that purpose in life is a cultural strength and an advantage among blacks in achieving sobriety. PMID:22707846

Cross-cultural Adaptation of the Oral Anticoagulation Knowledge Test to the Brazilian Portuguese.

PubMed

Praxedes, Marcus Fernando da Silva; Abreu, Mauro Henrique Nogueira Guimarães; Ribeiro, Daniel Dias; Marcolino, Milena Soriano; Paiva, Saul Martins de; Martins, Maria Auxiliadora Parreiras

2017-05-01

Patients' knowledge about oral anticoagulant therapy may favor the achievement of therapeutic results and the prevention of adverse pharmacotherapy-related events. Brazil lacks validated instruments for assessing the patient's knowledge about treatment with warfarin. This study aimed to perform the cross-cultural adaptation of the Oral Anticoagulation Knowledge (OAK) Test instrument from English into Portuguese. This is a methodological study developed in an anticoagulation clinic of a public university hospital. The study included initial translation, synthesis of translations, back-translation, review by the experts committee and pre-testing with 30 individuals. We obtained semantic equivalence through the analysis of the referential and general meaning of each item. The conceptual equivalence of the items sought to demonstrate the relevance and acceptability of the instrument. The process of cross-cultural adaptation produced the final version of the OAK Test in Brazilian Portuguese entitled "Teste de Conhecimento sobre Anticoagulação Oral". There was a suitable semantic and conceptual equivalence between the adapted version and the original version, as well as an excellent acceptability of this instrument.

Development of a multi-cycle shear-compression testing for the modeling of severe plastic deformation

NASA Astrophysics Data System (ADS)

Pesin, A.; Pustovoytov, D.; Lokotunina, N.

2017-12-01

The mechanism of severe plastic deformation comes from very significant shear strain. Shear-compression testing of materials is complicated by the fact that a state of large equivalent strain with dominant shear strain is not easily achievable. This paper presents the novel technique of laboratory simulation of severe plastic deformation by multi-cycle shear-compression testing at room temperature with equivalent strain e=1…5. The specimen consisted of a parallelepiped having an inclined gauge section created by two diametrically opposed semi-circular slots which were machined at 45°. Height of the specimen was 50 mm, section dimensions were 25×25 mm, gauge thickness was 5.0 mm and gauge width was 6.0 mm. The specimen provided dominant shear strain in an inclined gauge-section. The level of shear strain and equivalent strain was controlled through adjustment of the height reduction of the specimen, load application direction and number of cycles of shear-compression. Aluminium alloy Al-6.2Mg-0.7Mn was used as a material for specimen. FE simulation and analysis of the stress-strain state were performed. The microstructure of the specimen after multi-cycle shear-compression testing with equivalent strain e=1…5 was examined by optical and scanning electron microscope.

Hydrogen enrichment for low-emission jet combustion

NASA Technical Reports Server (NTRS)

Clayton, R. M.

1978-01-01

Simultaneous gaseous pollutant emission indexes (g pollutant/kg fuel) for a research combustor with inlet air at 120,900 N/sq m (11.9 atm) pressure and 727 K (849 F) temperature are as low as 1.0 for NOx and CO and 0.5 for unburned HC. Emissions data are presented for hydrogen/jet fuel (JP-5) mixes and for jet fuel only for premixed equivalence ratios from lean blowout to 0.65. Minimized emissions were achieved at an equivalence ratio of 0.38 using 10-12 mass percent hydrogen in the total fuel to depress the lean blowout limit. They were not achievable with jet fuel alone because of the onset of lean blowout at an equivalence ratio too high to reduce the NOx emission sufficiently.

Single-stage experimental evaluation of tandem-airfoil rotor and stator blading for compressors. Part 2: Data and performance for stage A

NASA Technical Reports Server (NTRS)

Brent, J. A.

1972-01-01

Stage A, comprised of a conventional rotor and stator, was designed and tested to establish a performance baseline for comparison with the results of subsequent tests planned for two tandem-blade stages. The rotor had an inlet hub/tip ratio of 0.8 and a design tip velocity of 757 ft/sec. At design equivalent rotor speed, rotor A achieved a maximum adiabatic efficiency of 85.1 percent at a pressure ratio of 1.29. The stage maximum adiabatic efficiency was 78.6 percent at a pressure ratio of 1.27.

Software Graphics Processing Unit (sGPU) for Deep Space Applications

NASA Technical Reports Server (NTRS)

McCabe, Mary; Salazar, George; Steele, Glen

2015-01-01

A graphics processing capability will be required for deep space missions and must include a range of applications, from safety-critical vehicle health status to telemedicine for crew health. However, preliminary radiation testing of commercial graphics processing cards suggest they cannot operate in the deep space radiation environment. Investigation into an Software Graphics Processing Unit (sGPU)comprised of commercial-equivalent radiation hardened/tolerant single board computers, field programmable gate arrays, and safety-critical display software shows promising results. Preliminary performance of approximately 30 frames per second (FPS) has been achieved. Use of multi-core processors may provide a significant increase in performance.

Stimulus-response learning in long-term cocaine users: acquired equivalence and probabilistic category learning.

PubMed

Vadhan, Nehal P; Myers, Catherine E; Rubin, Eric; Shohamy, Daphna; Foltin, Richard W; Gluck, Mark A

2008-01-11

The purpose of this study was to examine stimulus-response (S-R) learning in active cocaine users. Twenty-two cocaine-dependent participants (20 males and 2 females) and 21 non-drug using control participants (19 males and 2 females) who were similar in age and education were administered two computerized learning tasks. The Acquired Equivalence task initially requires learning of simple antecedent-consequent discriminations, but later requires generalization of this learning when the stimuli are presented in novel recombinations. The Weather Prediction task requires the prediction of a dichotomous outcome based on different stimuli combinations when the stimuli predict the outcome only probabilistically. On the Acquired Equivalence task, cocaine users made significantly more errors than control participants when required to learn new discriminations while maintaining previously learned discriminations, but performed similarly to controls when required to generalize this learning. No group differences were seen on the Weather Prediction task. Cocaine users' learning of stimulus discriminations under conflicting response demands was impaired, but their ability to generalize this learning once they achieved criterion was intact. This performance pattern is consistent with other laboratory studies of long-term cocaine users that demonstrated that established learning interfered with new learning on incremental learning tasks, relative to healthy controls, and may reflect altered dopamine transmission in the basal ganglia of long-term cocaine users.

Motor imagery training promotes motor learning in adolescents with cerebral palsy: comparison between left and right hemiparesis.

PubMed

Cabral-Sequeira, Audrey Sartori; Coelho, Daniel Boari; Teixeira, Luis Augusto

2016-06-01

This experiment was designed to evaluate the effects of pure motor imagery training (MIT) and its combination with physical practice on learning an aiming task with the more affected arm in adolescents suffering from cerebral palsy. Effect of MIT was evaluated as a function of side of hemiparesis. The experiment was accomplished by 11- to 16-year-old participants (M = 13.58 years), who suffered left (n = 16) or right (n = 15) mild hemiparesis. They were exposed to pure MIT (day 1) followed by physical practice (day 2) on an aiming task demanding movement accuracy and speed. Posttraining movement kinematics of the group receiving MIT were compared with movement kinematics of the control group after receiving recreational activities (day 1) and physical practice (day 2). Kinematic analysis showed that MIT led to decreased movement time and straighter hand displacements to the target. Performance achievements from MIT were increased with further physical practice, leading to enhanced effects on motor learning. Retention evaluation indicated that performance improvement from pure MIT and its combination with physical practice were stable over time. Performance achievements were equivalent between adolescents with either right or left hemiparesis, suggesting similar capacity between these groups to achieve performance improvement from pure imagery training and from its association with physical practice. Our results suggest that motor imagery training is a procedure potentially useful to increase motor learning achievements in individuals suffering from cerebral palsy.

Performance of mixed RF/FSO systems in exponentiated Weibull distributed channels

NASA Astrophysics Data System (ADS)

Zhao, Jing; Zhao, Shang-Hong; Zhao, Wei-Hu; Liu, Yun; Li, Xuan

2017-12-01

This paper presented the performances of asymmetric mixed radio frequency (RF)/free-space optical (FSO) system with the amplify-and-forward relaying scheme. The RF channel undergoes Nakagami- m channel, and the Exponentiated Weibull distribution is adopted for the FSO component. The mathematical formulas for cumulative distribution function (CDF), probability density function (PDF) and moment generating function (MGF) of equivalent signal-to-noise ratio (SNR) are achieved. According to the end-to-end statistical characteristics, the new analytical expressions of outage probability are obtained. Under various modulation techniques, we derive the average bit-error-rate (BER) based on the Meijer's G function. The evaluation and simulation are provided for the system performance, and the aperture average effect is discussed as well.

Learning Mathematics with Technology: The Influence of Virtual Manipulatives on Different Achievement Groups

ERIC Educational Resources Information Center

Moyer-Packenham, Patricia; Suh, Jennifer

2012-01-01

This study examined the influence of virtual manipulatives on different achievement groups during a teaching experiment in four fifth-grade classrooms. During a two-week unit focusing on two rational number concepts (fraction equivalence and fraction addition with unlike denominators) one low achieving, two average achieving, and one high…

Speaker recognition with temporal cues in acoustic and electric hearing

NASA Astrophysics Data System (ADS)

Vongphoe, Michael; Zeng, Fan-Gang

2005-08-01

Natural spoken language processing includes not only speech recognition but also identification of the speaker's gender, age, emotional, and social status. Our purpose in this study is to evaluate whether temporal cues are sufficient to support both speech and speaker recognition. Ten cochlear-implant and six normal-hearing subjects were presented with vowel tokens spoken by three men, three women, two boys, and two girls. In one condition, the subject was asked to recognize the vowel. In the other condition, the subject was asked to identify the speaker. Extensive training was provided for the speaker recognition task. Normal-hearing subjects achieved nearly perfect performance in both tasks. Cochlear-implant subjects achieved good performance in vowel recognition but poor performance in speaker recognition. The level of the cochlear implant performance was functionally equivalent to normal performance with eight spectral bands for vowel recognition but only to one band for speaker recognition. These results show a disassociation between speech and speaker recognition with primarily temporal cues, highlighting the limitation of current speech processing strategies in cochlear implants. Several methods, including explicit encoding of fundamental frequency and frequency modulation, are proposed to improve speaker recognition for current cochlear implant users.

Five Conditions Commonly Used to Down-regulate Tor Complex 1 Generate Different Physiological Situations Exhibiting Distinct Requirements and Outcomes*

PubMed Central

Tate, Jennifer J.; Cooper, Terrance G.

2013-01-01

Five different physiological conditions have been used interchangeably to establish the sequence of molecular events needed to achieve nitrogen-responsive down-regulation of TorC1 and its subsequent regulation of downstream reporters: nitrogen starvation, methionine sulfoximine (Msx) addition, nitrogen limitation, rapamycin addition, and leucine starvation. Therefore, we tested a specific underlying assumption upon which the interpretation of data generated by these five experimental perturbations is premised. It is that they generate physiologically equivalent outcomes with respect to TorC1, i.e. its down-regulation as reflected by TorC1 reporter responses. We tested this assumption by performing head-to-head comparisons of the requirements for each condition to achieve a common outcome for a downstream proxy of TorC1 inactivation, nuclear Gln3 localization. We demonstrate that the five conditions for down-regulating TorC1 do not elicit physiologically equivalent outcomes. Four of the methods exhibit hierarchical Sit4 and PP2A phosphatase requirements to elicit nuclear Gln3-Myc13 localization. Rapamycin treatment required Sit4 and PP2A. Nitrogen limitation and short-term nitrogen starvation required only Sit4. G1 arrest-correlated, long-term nitrogen starvation and Msx treatment required neither PP2A nor Sit4. Starving cells of leucine or treating them with leucyl-tRNA synthetase inhibitors did not elicit nuclear Gln3-Myc13 localization. These data indicate that the five commonly used nitrogen-related conditions of down-regulating TorC1 are not physiologically equivalent and minimally involve partially differing regulatory mechanisms. Further, identical requirements for Msx treatment and long-term nitrogen starvation raise the possibility that their effects are achieved through a common regulatory pathway with glutamine, a glutamate or glutamine metabolite level as the sensed metabolic signal. PMID:23935103

Equivalence and Relational Thinking: Opportunities for Professional Learning

ERIC Educational Resources Information Center

Vale, Colleen

2013-01-01

Colleen Vale makes the case for professional learning teams collaborating together to improve their teaching and hence children's achievement. In this article she describes how this may be done. Along the way the teachers explored the idea of equivalence and the common conceptions and misconceptions held by children in their classes.

Turbodrilling performance offshore Qatar

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

Rana, L.A.; Abdulrahman, E.A.

Until the first quarter of 1979 Qatar General Petroleum Corporation Offshore routinely rotary drilled its vertical development wells using tricone bits. Turbodrilling the 17 1/2'' and 8 1/2'' hole sections was introduced in the second quarter of 1979 followed by the 12 1/4'' hole section in the first qarter of 1980. This resulted in avoiding/minimising downhole problems and the elimination of 7'' and 4 1/2'' liners. As a result of introducing these practices a 50 percent time saving and a 30 percent cost saving has been achieved, equivalent to $550,000/well.

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

Li, Sucheng; Duan, Qian; Li, Shuo

We experimentally demonstrate that perfect electromagnetic absorption can be realized in the one-atom thick graphene. Employing coherent illumination in the waveguide system, the absorbance of the unpatterned graphene monolayer is observed to be greater than 94% over the microwave X-band, 7–13 GHz, and to achieve a full absorption, >99% in experiment, at ∼8.3 GHz. In addition, the absorption characteristic manifests equivalently a wide range of incident angle. The experimental results agree very well with the theoretical calculations. Our work accomplishes the broadband, wide-angle, high-performance absorption in the thinnest material with simple configuration.

Long-Wavelength 640 x 486 GaAs/AlGaAs Quantum Well Infrared Photodetector Snap-Shot Camera

NASA Technical Reports Server (NTRS)

Gunapala, Sarath D.; Bandara, Sumith V.; Liu, John K.; Hong, Winn; Sundaram, Mani; Maker, Paul D.; Muller, Richard E.; Shott, Craig A.; Carralejo, Ronald

1998-01-01

A 9-micrometer cutoff 640 x 486 snap-shot quantum well infrared photodetector (QWIP) camera has been demonstrated. The performance of this QWIP camera is reported including indoor and outdoor imaging. The noise equivalent differential temperature (NE.deltaT) of 36 mK has been achieved at 300 K background with f/2 optics. This is in good agreement with expected focal plane array sensitivity due to the practical limitations on charge handling capacity of the multiplexer, read noise, bias voltage, and operating temperature.

Detailing the equivalence between real equiangular tight frames and certain strongly regular graphs

NASA Astrophysics Data System (ADS)

Fickus, Matthew; Watson, Cody E.

2015-08-01

An equiangular tight frame (ETF) is a set of unit vectors whose coherence achieves the Welch bound, and so is as incoherent as possible. They arise in numerous applications. It is well known that real ETFs are equivalent to a certain subclass of strongly regular graphs. In this note, we give some alternative techniques for understanding this equivalence. In a later document, we will use these techniques to further generalize this theory.

First scientific application of the membrane cryostat technology

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

Montanari, David; Adamowski, Mark; Baller, Bruce R.

2014-01-29

We report on the design, fabrication, performance and commissioning of the first membrane cryostat to be used for scientific application. The Long Baseline Neutrino Experiment (LBNE) has designed and fabricated a membrane cryostat prototype in collaboration with IHI Corporation (IHI). Original goals of the prototype are: to demonstrate the membrane cryostat technology in terms of thermal performance, feasibility for liquid argon, and leak tightness; to demonstrate that we can remove all the impurities from the vessel and achieve the purity requirements in a membrane cryostat without evacuation and using only a controlled gaseous argon purge; to demonstrate that we canmore » achieve and maintain the purity requirements of the liquid argon during filling, purification, and maintenance mode using mole sieve and copper filters from the Liquid Argon Purity Demonstrator (LAPD) R and D project. The purity requirements of a large liquid argon detector such as LBNE are contaminants below 200 parts per trillion oxygen equivalent. This paper gives the requirements, design, construction, and performance of the LBNE membrane cryostat prototype, with experience and results important to the development of the LBNE detector.« less

Design and construction of high-sensitivity, infrared bolometers for operation at 300 mK

NASA Technical Reports Server (NTRS)

Alsop, D. C.; Inman, C.; Lange, A. E.; Wibanks, T.

1992-01-01

The design and construction of 300-mK composite bolometers developed for millimeter-wave astronomical observations are described. Graphite fibers are used as the electrical leads for the thermistor to reduce the thermal conductance and heat capacity associated with the leads. A mechanical suspension made of Nylon fibers provides the required thermal conductance. Electrical noise equivalent powers below 1 x 10 exp -16 W/sq rt Hz have been achieved for detectors with thermal time constants of 11 ms. The detectors were installed in a millimeter-wave photometer and used to perform observations of the cosmic microwave background from a balloonborne platform. The flight performance was consistent with the measured laboratory properties.

Flight Deck Technologies to Enable NextGen Low Visibility Surface Operations

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence (Lance) J., III; Arthur, Jarvis (Trey) J.; Kramer, Lynda J.; Norman, Robert M.; Bailey, Randall E.; Jones, Denise R.; Karwac, Jerry R., Jr.; Shelton, Kevin J.; Ellis, Kyle K. E.

2013-01-01

Many key capabilities are being identified to enable Next Generation Air Transportation System (NextGen), including the concept of Equivalent Visual Operations (EVO) . replicating the capacity and safety of today.s visual flight rules (VFR) in all-weather conditions. NASA is striving to develop the technologies and knowledge to enable EVO and to extend EVO towards a Better-Than-Visual operational concept. This operational concept envisions an .equivalent visual. paradigm where an electronic means provides sufficient visual references of the external world and other required flight references on flight deck displays that enable Visual Flight Rules (VFR)-like operational tempos while maintaining and improving safety of VFR while using VFR-like procedures in all-weather conditions. The Langley Research Center (LaRC) has recently completed preliminary research on flight deck technologies for low visibility surface operations. The work assessed the potential of enhanced vision and airport moving map displays to achieve equivalent levels of safety and performance to existing low visibility operational requirements. The work has the potential to better enable NextGen by perhaps providing an operational credit for conducting safe low visibility surface operations by use of the flight deck technologies.

Double gate impact ionization MOS transistor: Proposal and investigation

NASA Astrophysics Data System (ADS)

Yang, Zhaonian; Zhang, Yue; Yang, Yuan; Yu, Ningmei

2017-02-01

In this paper, a double gate impact ionization MOS (DG-IMOS) transistor with improved performance is proposed and investigated by TCAD simulation. In the proposed design, a second gate is introduced in a conventional impact ionization MOS (IMOS) transistor that lengthens the equivalent channel length and suppresses the band-to-band tunneling. The OFF-state leakage current is reduced by over four orders of magnitude. At the ON-state, the second gate is negatively biased in order to enhance the electric field in the intrinsic region. As a result, the operating voltage does not increase with the increase in the channel length. The simulation result verifies that the proposed DG-IMOS achieves a better switching characteristic than the conventional is achieved. Lastly, the application of the DG-IMOS is discussed theoretically.

Complex task performance in Cyberspace. Surgical procedures in a telepresence environment.

PubMed

Bowersox, J C; LaPorta, A J; Cordts, P R; Bhoyrul, S; Shah, A

1996-01-01

To assess the capabilities of our fully functional, prototype telepresence surgery system, experienced surgeons performed complete operative procedures on live, anesthetized pigs. Cholecystectomy, the prototypical procedure for evaluating the integration of surgical skills, was successfully performed in six animals. There were no aborted attempts or complications. Other procedures completed included gastrotomy and enterotomy closures, anastomosis of the small intestine, and nephrectomy. No specific training was required for using the telepresence surgery system, and the "feel" of the system was described as intuitive. Operative times were longer than required in conventional, open surgery, most likely the result of the four degrees of freedom available in the manipulators of the current-generation system. Force feedback and high-resolution, stereoscopic video input facilitated performance. Surgeons operating through a first-generation telepresence system can achieve technical results equivalent to those obtained in conventional surgery.

Analytical performance of 17 general chemistry analytes across countries and across manufacturers in the INPUtS project of EQA organizers in Italy, the Netherlands, Portugal, United Kingdom and Spain.

PubMed

Weykamp, Cas; Secchiero, Sandra; Plebani, Mario; Thelen, Marc; Cobbaert, Christa; Thomas, Annette; Jassam, Nuthar; Barth, Julian H; Perich, Carmen; Ricós, Carmen; Faria, Ana Paula

2017-02-01

Optimum patient care in relation to laboratory medicine is achieved when results of laboratory tests are equivalent, irrespective of the analytical platform used or the country where the laboratory is located. Standardization and harmonization minimize differences and the success of efforts to achieve this can be monitored with international category 1 external quality assessment (EQA) programs. An EQA project with commutable samples, targeted with reference measurement procedures (RMPs) was organized by EQA institutes in Italy, the Netherlands, Portugal, UK, and Spain. Results of 17 general chemistry analytes were evaluated across countries and across manufacturers according to performance specifications derived from biological variation (BV). For K, uric acid, glucose, cholesterol and high-density density (HDL) cholesterol, the minimum performance specification was met in all countries and by all manufacturers. For Na, Cl, and Ca, the minimum performance specifications were met by none of the countries and manufacturers. For enzymes, the situation was complicated, as standardization of results of enzymes toward RMPs was still not achieved in 20% of the laboratories and questionable in the remaining 80%. The overall performance of the measurement of 17 general chemistry analytes in European medical laboratories met the minimum performance specifications. In this general picture, there were no significant differences per country and no significant differences per manufacturer. There were major differences between the analytes. There were six analytes for which the minimum quality specifications were not met and manufacturers should improve their performance for these analytes. Standardization of results of enzymes requires ongoing efforts.

Does the choice of mobile C-arms lead to a reduction of the intraoperative radiation dose?

PubMed

Richter, P H; Steinbrener, J; Schicho, A; Gebhard, F

2016-08-01

Mobile C-arm imaging is commonly used in operating rooms worldwide. Especially in orthopaedic surgery, intraoperative C-arms are used on a daily basis. Because of new minimally-invasive surgical procedures a development in intraoperative imaging is required. The purpose of this article is investigate if the choice of mobile C-arms with flat panel detector technology (Siemens Cios Alpha and Ziehm Vision RFD) influences image quality and dose using standard, commercially available test devices. For a total of four clinical application settings, two zoom formats, and all dose levels provided, the transmission dose was measured and representative images were recorded for each test device. The data was scored by four observers to assess low contrast and spatial resolution performance. The results were converted to a relative image quality figure allowing for a direct image quality and dose comparison of the two systems. For one test device, the Cios Alpha system achieved equivalent (within the inter-observer standard error) or better low contrast resolution scores at significantly lower dose levels, while the results of the other test device suggested that both systems achieved similar image quality at the same dose. The Cios Alpha system achieved equivalent or better spatial resolution at significantly lower dose for all application settings except for Cardiac, where a comparable spatial resolution was achieved at the same dose. The correct choice of a mobile C-arm is very important, because it can lead to a reduction of the intraoperative radiation dose without negative effects on image quality. This can be a big advantage to reduce intraoperative radiation not only for the patient but also for the entire OR-team. Copyright © 2016. Published by Elsevier Ltd.

Ambient Dose Equivalent measured at the Instituto Nacional de Cancerología Department of Nuclear Medicine

NASA Astrophysics Data System (ADS)

Ávila, O.; Torres-Ulloa, C. L.; Medina, L. A.; Trujillo-Zamudio, F. E.; de Buen, I. Gamboa; Buenfil, A. E.; Brandan, M. E.

2010-12-01

Ambient dose equivalent values were determined in several sites at the Instituto Nacional de Cancerología, Departmento de Medicina Nuclear, using TLD-100 and TLD-900 thermoluminescent dosemeters. Additionally, ambient dose equivalent was measured at a corridor outside the hospitalization room for patients treated with 137Cs brachytherapy. Dosemeter calibration was performed at the Instituto Nacional de Investigaciones Nucleares, Laboratorio de Metrología, to known 137Cs gamma radiation air kerma. Radionuclides considered for this study are 131I, 18F, 67Ga, 99mTc, 111In, 201Tl and 137Cs, with main gamma energies between 93 and 662 keV. Dosemeters were placed during a five month period in the nuclear medicine rooms (containing gamma-cameras), injection corridor, patient waiting areas, PET/CT study room, hot lab, waste storage room and corridors next to the hospitalization rooms for patients treated with 131I and 137Cs. High dose values were found at the waste storage room, outside corridor of 137Cs brachytherapy patients and PET/CT area. Ambient dose equivalent rate obtained for the 137Cs brachytherapy corridor is equal to (18.51±0.02)×10-3 mSv/h. Sites with minimum doses are the gamma camera rooms, having ambient dose equivalent rates equal to (0.05±0.03)×10-3 mSv/h. Recommendations have been given to the Department authorities so that further actions are taken to reduce doses at high dose sites in order to comply with the ALARA principle (as low as reasonably achievable).

Test Results for Entry Guidance Methods for Space Vehicles

NASA Technical Reports Server (NTRS)

Hanson, John M.; Jones, Robert E.

2004-01-01

There are a number of approaches to advanced guidance and control that have the potential for achieving the goals of significantly increasing reusable launch vehicle (or any space vehicle that enters an atmosphere) safety and reliability, and reducing the cost. This paper examines some approaches to entry guidance. An effort called Integration and Testing of Advanced Guidance and Control Technologies has recently completed a rigorous testing phase where these algorithms faced high-fidelity vehicle models and were required to perform a variety of representative tests. The algorithm developers spent substantial effort improving the algorithm performance in the testing. This paper lists the test cases used to demonstrate that the desired results are achieved, shows an automated test scoring method that greatly reduces the evaluation effort required, and displays results of the tests. Results show a significant improvement over previous guidance approaches. The two best-scoring algorithm approaches show roughly equivalent results and are ready to be applied to future vehicle concepts.

Test Results for Entry Guidance Methods for Reusable Launch Vehicles

NASA Technical Reports Server (NTRS)

Hanson, John M.; Jones, Robert E.

2003-01-01

There are a number of approaches to advanced guidance and control (AG&C) that have the potential for achieving the goals of significantly increasing reusable launch vehicle (RLV) safety and reliability, and reducing the cost. This paper examines some approaches to entry guidance. An effort called Integration and Testing of Advanced Guidance and Control Technologies (ITAGCT) has recently completed a rigorous testing phase where these algorithms faced high-fidelity vehicle models and were required to perform a variety of representative tests. The algorithm developers spent substantial effort improving the algorithm performance in the testing. This paper lists the test cases used to demonstrate that the desired results are achieved, shows an automated test scoring method that greatly reduces the evaluation effort required, and displays results of the tests. Results show a significant improvement over previous guidance approaches. The two best-scoring algorithm approaches show roughly equivalent results and are ready to be applied to future reusable vehicle concepts.

Upgrade to the Birmingham Irradiation Facility

NASA Astrophysics Data System (ADS)

Dervan, P.; French, R.; Hodgson, P.; Marin-Reyes, H.; Parker, K.; Wilson, J.; Baca, M.

2015-10-01

The Birmingham Irradiation Facility was developed in 2013 at the University of Birmingham using the Medical Physics MC40 cyclotron. It can achieve High Luminosity LHC (HL-LHC) fluences of 1015 (1 MeV neutron equivalent (neq)) cm-2 in 80 s with proton beam currents of 1 μA and so can evaluate effectively the performance and durability of detector technologies and new components to be used for the HL-LHC. Irradiations of silicon sensors and passive materials can be carried out in a temperature controlled cold box which moves continuously through the homogenous beamspot. This movement is provided by a pre-configured XY-axis Cartesian robot scanning system. In 2014 the cooling system and cold box were upgraded from a recirculating glycol chiller system to a liquid nitrogen evaporative system. The new cooling system achieves a stable temperature of -50 °C in 30 min and aims to maintain sub-0 °C temperatures on the sensors during irradiations. This paper reviews the design, development, commissioning and performance of the new cooling system.

Experimental demonstration of deep frequency modulation interferometry.

PubMed

Isleif, Katharina-Sophie; Gerberding, Oliver; Schwarze, Thomas S; Mehmet, Moritz; Heinzel, Gerhard; Cervantes, Felipe Guzmán

2016-01-25

Experiments for space and ground-based gravitational wave detectors often require a large dynamic range interferometric position readout of test masses with 1 pm/√Hz precision over long time scales. Heterodyne interferometer schemes that achieve such precisions are available, but they require complex optical set-ups, limiting their scalability for multiple channels. This article presents the first experimental results on deep frequency modulation interferometry, a new technique that combines sinusoidal laser frequency modulation in unequal arm length interferometers with a non-linear fit algorithm. We have tested the technique in a Michelson and a Mach-Zehnder Interferometer topology, respectively, demonstrated continuous phase tracking of a moving mirror and achieved a performance equivalent to a displacement sensitivity of 250 pm/Hz at 1 mHz between the phase measurements of two photodetectors monitoring the same optical signal. By performing time series fitting of the extracted interference signals, we measured that the linearity of the laser frequency modulation is on the order of 2% for the laser source used.

Biological equivalence between LDR and PDR in cervical cancer: multifactor analysis using the linear-quadratic model.

PubMed

Couto, José Guilherme; Bravo, Isabel; Pirraco, Rui

2011-09-01

The purpose of this work was the biological comparison between Low Dose Rate (LDR) and Pulsed Dose Rate (PDR) in cervical cancer regarding the discontinuation of the afterloading system used for the LDR treatments at our Institution since December 2009. In the first phase we studied the influence of the pulse dose and the pulse time in the biological equivalence between LDR and PDR treatments using the Linear Quadratic Model (LQM). In the second phase, the equivalent dose in 2 Gy/fraction (EQD(2)) for the tumor, rectum and bladder in treatments performed with both techniques was evaluated and statistically compared. All evaluated patients had stage IIB cervical cancer and were treated with External Beam Radiotherapy (EBRT) plus two Brachytherapy (BT) applications. Data were collected from 48 patients (26 patients treated with LDR and 22 patients with PDR). In the analyses of the influence of PDR parameters in the biological equivalence between LDR and PDR treatments (Phase 1), it was calculated that if the pulse dose in PDR was kept equal to the LDR dose rate, a small the-rapeutic loss was expected. If the pulse dose was decreased, the therapeutic window became larger, but a correction in the prescribed dose was necessary. In PDR schemes with 1 hour interval between pulses, the pulse time did not influence significantly the equivalent dose. In the comparison between the groups treated with LDR and PDR (Phase 2) we concluded that they were not equivalent, because in the PDR group the total EQD(2) for the tumor, rectum and bladder was smaller than in the LDR group; the LQM estimated that a correction in the prescribed dose of 6% to 10% was ne-cessary to avoid therapeutic loss. A correction in the prescribed dose was necessary; this correction should be achieved by calculating the PDR dose equivalent to the desired LDR total dose.

Biological equivalence between LDR and PDR in cervical cancer: multifactor analysis using the linear-quadratic model

PubMed Central

Bravo, Isabel; Pirraco, Rui

2011-01-01

Purpose The purpose of this work was the biological comparison between Low Dose Rate (LDR) and Pulsed Dose Rate (PDR) in cervical cancer regarding the discontinuation of the afterloading system used for the LDR treatments at our Institution since December 2009. Material and methods In the first phase we studied the influence of the pulse dose and the pulse time in the biological equivalence between LDR and PDR treatments using the Linear Quadratic Model (LQM). In the second phase, the equivalent dose in 2 Gy/fraction (EQD2) for the tumor, rectum and bladder in treatments performed with both techniques was evaluated and statistically compared. All evaluated patients had stage IIB cervical cancer and were treated with External Beam Radiotherapy (EBRT) plus two Brachytherapy (BT) applications. Data were collected from 48 patients (26 patients treated with LDR and 22 patients with PDR). Results In the analyses of the influence of PDR parameters in the biological equivalence between LDR and PDR treatments (Phase 1), it was calculated that if the pulse dose in PDR was kept equal to the LDR dose rate, a small the-rapeutic loss was expected. If the pulse dose was decreased, the therapeutic window became larger, but a correction in the prescribed dose was necessary. In PDR schemes with 1 hour interval between pulses, the pulse time did not influence significantly the equivalent dose. In the comparison between the groups treated with LDR and PDR (Phase 2) we concluded that they were not equivalent, because in the PDR group the total EQD2 for the tumor, rectum and bladder was smaller than in the LDR group; the LQM estimated that a correction in the prescribed dose of 6% to 10% was ne-cessary to avoid therapeutic loss. Conclusions A correction in the prescribed dose was necessary; this correction should be achieved by calculating the PDR dose equivalent to the desired LDR total dose. PMID:23346123

Single-stage experimental evaluation of tandem-airfoil rotor and stator blading for compressors. Part 3: Data and performance for stage C

NASA Technical Reports Server (NTRS)

Brent, J. A.; Clemmons, D.

1972-01-01

Stage C, comprised of tandem-airfoil rotor C and tandem-airfoil stator B, was designed and tested to establish performance data for comparison with the performance of conventional single-airfoil blading. Velocity diagrams and blade leading and trailing edge metal angles selected for the conventional rotor and stator blading were used in the design of the tandem blading. The rotor had an inlet hub/tip ratio of 0.8 and a design tip velocity of 757 ft/sec. At design equivalent rotor speed, rotor C achieved a maximum adiabatic efficiency of 91.8% at a pressure ratio of 1.31. The stage maximum adiabatic efficiency was 86.5% at a pressure ratio of 1.31.

The Microscope Mission and Pre-Flight Performance Verification

NASA Astrophysics Data System (ADS)

Hudson, D.; Touboul, P.; Rodrigues, M.

2006-04-01

Recent developments in fundamental physics have renewed interest in disproving the equivalence principle. The MICROSCOPE mission will be the first test to capitalize on the advantages of space to achieve an accuracy of 10-15, more than two orders of magnitude better than current ground based results. It is a joint CNES, ONERA, and Observatoire de la Côte d'Azur mission in the CNES Myriade microsatellite program. The principle of the test is to place two masses of different material on precisely the same orbit and measure any difference in the forces required to maintain the common orbit. The test is performed by a differential electrostatic accelerometer containing two concentric cylindrical test masses. This paper will present both an overview of the mission, and a description of the accelerometer development and performance verification.

Single stage experimental evaluation of tandem-airfoil rotor and stator blading for compressors. Part 4: Data and performance for stage B

NASA Technical Reports Server (NTRS)

Brent, J. A.; Cheatham, J. G.

1973-01-01

Stage B, composed of tandem-airfoil rotor B and stator B, was tested with uniform inlet flow and with hub radial, tip radial and 90 degree one-per-revolution circumferential distortion of the inlet flow as part of an overall program to evaluate the effectiveness of tandem airfoils for increasing the design point loading capability and stable operating range of rotor and stator blading. The results of this series of tests provide overall performance and blade element data for evaluating: (1) the potential of tandem blading for extending the loading limit and stable operating range of a stage representative of a middle stage of an advanced high pressure compressor, (2) the effect of loading split between the two airfoils in tandem on the performance of tandem blading, and (3) the effects of inlet flow distortion on the stage performance. The rotor had an inlet hub/tip ratio of 0.8 and a design tip velocity of 757 ft/sec. With uniform inlet flow, rotor B achieved a maximum adiabatic efficiency of 88.4% at design equivalent rotor speed and a pressure ratio of 1.31. The stage maximum adiabatic efficiency at design equivalent rotor speed with uniform inlet flow was 82.5% at a pressure ratio of 1.28. Tip radial and circumferential distortion of the inlet flow caused substantial reductions in surge margin.

Single-stage experimental evaluation of tandem-airfoil rotor stator blading for compressors. Part 6: Data and performance for stage D

NASA Technical Reports Server (NTRS)

Clemmons, D. R.

1973-01-01

An axial flow compressor stage, having single-airfoil blading, was designed for zero rotor prewhirl, constant rotor work across the span, and axial discharge flow. The stage was designed to produce a pressure ratio of 1.265 at a rotor tip velocity of 757 ft/sec. The rotor had an inlet hub/tip ratio of 0.8. The design procedure accounted for the rotor inlet boundary layer and included the effects of axial velocity ratio and secondary flow on blade row performance. The objectives of this experimental program were: (1) to obtain performance with uniform and distorted inlet flow for comparison with the performance of a stage consisting of tandem-airfoil blading designed for the same vector diagrams; and (2) to evaluate the effectiveness of accounting for the inlet boundary layer, axial velocity ratio, and secondary flows in the stage design. With uniform inlet flow, the rotor achieved a maximum adiabatic efficiency of 90.1% at design equivalent rotor speed and a pressure ratio of 1.281. The stage maximum adiabatic efficiency at design equivalent rotor speed with uniform inlet flow was 86.1% at a pressure ratio of 1.266. Hub radial, tip radial, and circumferential distortion of the inlet flow caused reductions in surge pressure ratio of approximately 2, 10 and 5%, respectively, at design rotor speed.

77 FR 68200 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-15

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77 FR 68199 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

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75 FR 77949 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

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75 FR 8186 - Qualification of Drivers; Exemption Renewals; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-23

... concluded that granting these exemptions will provide a level of safety that will be equivalent to, or... ``such exemption would likely achieve a level of safety that is equivalent to, or greater than, the level... conditions of the exemption; (2) the exemption has resulted in a lower level of safety than was maintained...

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

Barstow, Del R; Patlolla, Dilip Reddy; Mann, Christopher J

Abstract The data captured by existing standoff biometric systems typically has lower biometric recognition performance than their close range counterparts due to imaging challenges, pose challenges, and other factors. To assist in overcoming these limitations systems typically perform in a multi-modal capacity such as Honeywell s Combined Face and Iris (CFAIRS) [21] system. While this improves the systems performance, standoff systems have yet to be proven as accurate as their close range equivalents. We will present a standoff system capable of operating up to 7 meters in range. Unlike many systems such as the CFAIRS our system captures high qualitymore » 12 MP video allowing for a multi-sample as well as multi-modal comparison. We found that for standoff systems multi-sample improved performance more than multi-modal. For a small test group of 50 subjects we were able to achieve 100% rank one recognition performance with our system.« less

Wideband optical sensing using pulse interferometry.

PubMed

Rosenthal, Amir; Razansky, Daniel; Ntziachristos, Vasilis

2012-08-13

Advances in fabrication of high-finesse optical resonators hold promise for the development of miniaturized, ultra-sensitive, wide-band optical sensors, based on resonance-shift detection. Many potential applications are foreseen for such sensors, among them highly sensitive detection in ultrasound and optoacoustic imaging. Traditionally, sensor interrogation is performed by tuning a narrow linewidth laser to the resonance wavelength. Despite the ubiquity of this method, its use has been mostly limited to lab conditions due to its vulnerability to environmental factors and the difficulty of multiplexing - a key factor in imaging applications. In this paper, we develop a new optical-resonator interrogation scheme based on wideband pulse interferometry, potentially capable of achieving high stability against environmental conditions without compromising sensitivity. Additionally, the method can enable multiplexing several sensors. The unique properties of the pulse-interferometry interrogation approach are studied theoretically and experimentally. Methods for noise reduction in the proposed scheme are presented and experimentally demonstrated, while the overall performance is validated for broadband optical detection of ultrasonic fields. The achieved sensitivity is equivalent to the theoretical limit of a 6 MHz narrow-line width laser, which is 40 times higher than what can be usually achieved by incoherent interferometry for the same optical resonator.

Leveraging Principal Evaluations to Scale up Instructional Improvement

ERIC Educational Resources Information Center

Fenton, Ben

2016-01-01

Strong school leaders play a vital role in accelerating student achievement across a state. Research has found that principals account for 25 percent of a school's total impact on student achievement, and an above-average principal can raise student achievement by as much as 20 percentage points more than an average principal--equivalent to seven…

Thermofluidic compression effects to achieve combustion in a low-compression scramjet engine

NASA Astrophysics Data System (ADS)

Moura, A. F.; Wheatley, V.; Jahn, I.

2018-07-01

The compression provided by a scramjet inlet is an important parameter in its design. It must be low enough to limit thermal and structural loads and stagnation pressure losses, but high enough to provide the conditions favourable for combustion. Inlets are typically designed to achieve sufficient compression without accounting for the fluidic, and subsequently thermal, compression provided by the fuel injection, which can enable robust combustion in a low-compression engine. This is investigated using Reynolds-averaged Navier-Stokes numerical simulations of a simplified scramjet engine designed to have insufficient compression to auto-ignite fuel in the absence of thermofluidic compression. The engine was designed with a wide rectangular combustor and a single centrally located injector, in order to reduce three-dimensional effects of the walls on the fuel plume. By varying the injected mass flow rate of hydrogen fuel (equivalence ratios of 0.22, 0.17, and 0.13), it is demonstrated that higher equivalence ratios lead to earlier ignition and more rapid combustion, even though mean conditions in the combustor change by no more than 5% for pressure and 3% for temperature with higher equivalence ratio. By supplementing the lower equivalence ratio with helium to achieve a higher mass flow rate, it is confirmed that these benefits are primarily due to the local compression provided by the extra injected mass. Investigation of the conditions around the fuel plume indicated two connected mechanisms. The higher mass flow rate for higher equivalence ratios generated a stronger injector bow shock that compresses the free-stream gas, increasing OH radical production and promoting ignition. This was observed both in the higher equivalence ratio case and in the case with helium. This earlier ignition led to increased temperature and pressure downstream and, consequently, stronger combustion. The heat release from combustion provided thermal compression in the combustor, further increasing combustion efficiency.

Thermofluidic compression effects to achieve combustion in a low-compression scramjet engine

NASA Astrophysics Data System (ADS)

Moura, A. F.; Wheatley, V.; Jahn, I.

2017-12-01

The compression provided by a scramjet inlet is an important parameter in its design. It must be low enough to limit thermal and structural loads and stagnation pressure losses, but high enough to provide the conditions favourable for combustion. Inlets are typically designed to achieve sufficient compression without accounting for the fluidic, and subsequently thermal, compression provided by the fuel injection, which can enable robust combustion in a low-compression engine. This is investigated using Reynolds-averaged Navier-Stokes numerical simulations of a simplified scramjet engine designed to have insufficient compression to auto-ignite fuel in the absence of thermofluidic compression. The engine was designed with a wide rectangular combustor and a single centrally located injector, in order to reduce three-dimensional effects of the walls on the fuel plume. By varying the injected mass flow rate of hydrogen fuel (equivalence ratios of 0.22, 0.17, and 0.13), it is demonstrated that higher equivalence ratios lead to earlier ignition and more rapid combustion, even though mean conditions in the combustor change by no more than 5% for pressure and 3% for temperature with higher equivalence ratio. By supplementing the lower equivalence ratio with helium to achieve a higher mass flow rate, it is confirmed that these benefits are primarily due to the local compression provided by the extra injected mass. Investigation of the conditions around the fuel plume indicated two connected mechanisms. The higher mass flow rate for higher equivalence ratios generated a stronger injector bow shock that compresses the free-stream gas, increasing OH radical production and promoting ignition. This was observed both in the higher equivalence ratio case and in the case with helium. This earlier ignition led to increased temperature and pressure downstream and, consequently, stronger combustion. The heat release from combustion provided thermal compression in the combustor, further increasing combustion efficiency.

Design and development of multilayer vascular graft

NASA Astrophysics Data System (ADS)

Madhavan, Krishna

2011-07-01

Vascular graft is a widely-used medical device for the treatment of vascular diseases such as atherosclerosis and aneurysm as well as for the use of vascular access and pediatric shunt, which are major causes of mortality and morbidity in this world. Dysfunction of vascular grafts often occurs, particularly for grafts with diameter less than 6mm, and is associated with the design of graft materials. Mechanical strength, compliance, permeability, endothelialization and availability are issues of most concern for vascular graft materials. To address these issues, we have designed a biodegradable, compliant graft made of hybrid multilayer by combining an intimal equivalent, electrospun heparin-impregnated poly-epsilon-caprolactone nanofibers, with a medial equivalent, a crosslinked collagen-chitosan-based gel scaffold. The intimal equivalent is designed to build mechanical strength and stability suitable for in vivo grafting and to prevent thrombosis. The medial equivalent is designed to serve as a scaffold for the activity of the smooth muscle cells important for vascular healing and regeneration. Our results have shown that genipin is a biocompatible crosslinker to enhance the mechanical properties of collagen-chitosan based scaffolds, and the degradation time and the activity of smooth muscle cells in the scaffold can be modulated by the crosslinking degree. For vascular grafting and regeneration in vivo, an important design parameter of the hybrid multilayer is the interface adhesion between the intimal and medial equivalents. With diametrically opposite affinities to water, delamination of the two layers occurs. Physical or chemical modification techniques were thus used to enhance the adhesion. Microscopic examination and graft-relevant functional characterizations have been performed to evaluate these techniques. Results from characterization of microstructure and functional properties, including burst strength, compliance, water permeability and suture strength, showed that the multilayer graft possessed properties mimicking those of native vessels. Achieving these FDA-required functional properties is essential because they play critical roles in graft performances in vivo such as thrombus formation, occlusion, healing, and bleeding. In addition, cell studies and animal studies have been performed on the multilayer graft. Our results show that the multilayer graft support mimetic vascular culture of cells and the acellular graft serves as an artery equivalent in vivo to sustain the physiological conditions and promote appropriate cellular activity. In conclusion, the newly-developed hybrid multilayer graft provides a proper balance of biomechanical and biochemical properties and demonstrates the potential for the use of vascular tissue engineering and regeneration.

Incorporating Cancer Stem Cells in Radiation Therapy Treatment Response Modeling and the Implication in Glioblastoma Multiforme Treatment Resistance

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

Yu, Victoria Y.; Nguyen, Dan; Pajonk, Frank

Purpose: To perform a preliminary exploration with a simplistic mathematical cancer stem cell (CSC) interaction model to determine whether the tumor-intrinsic heterogeneity and dynamic equilibrium between CSCs and differentiated cancer cells (DCCs) can better explain radiation therapy treatment response with a dual-compartment linear-quadratic (DLQ) model. Methods and Materials: The radiosensitivity parameters of CSCs and DCCs for cancer cell lines including glioblastoma multiforme (GBM), non–small cell lung cancer, melanoma, osteosarcoma, and prostate, cervical, and breast cancer were determined by performing robust least-square fitting using the DLQ model on published clonogenic survival data. Fitting performance was compared with the single-compartment LQ (SLQ) and universalmore » survival curve models. The fitting results were then used in an ordinary differential equation describing the kinetics of DCCs and CSCs in response to 2- to 14.3-Gy fractionated treatments. The total dose to achieve tumor control and the fraction size that achieved the least normal biological equivalent dose were calculated. Results: Smaller cell survival fitting errors were observed using DLQ, with the exception of melanoma, which had a low α/β = 0.16 in SLQ. Ordinary differential equation simulation indicated lower normal tissue biological equivalent dose to achieve the same tumor control with a hypofractionated approach for 4 cell lines for the DLQ model, in contrast to SLQ, which favored 2 Gy per fraction for all cells except melanoma. The DLQ model indicated greater tumor radioresistance than SLQ, but the radioresistance was overcome by hypofractionation, other than the GBM cells, which responded poorly to all fractionations. Conclusion: The distinct radiosensitivity and dynamics between CSCs and DCCs in radiation therapy response could perhaps be one possible explanation for the heterogeneous intertumor response to hypofractionation and in some cases superior outcome from stereotactic ablative radiation therapy. The DLQ model also predicted the remarkable GBM radioresistance, a result that is highly consistent with clinical observations. The radioresistance putatively stemmed from accelerated DCC regrowth that rapidly restored compartmental equilibrium between CSCs and DCCs.« less

34 CFR 361.84 - Performance indicators.

Code of Federal Regulations, 2012 CFR

2012-07-01

... competitive, self-, or BEP employment with earnings equivalent to at least the minimum wage. (iv) Performance... earnings equivalent to at least the minimum wage, the percentage who are individuals with significant... program in competitive, self-, or BEP employment with earnings levels equivalent to at least the minimum...

34 CFR 361.84 - Performance indicators.

Code of Federal Regulations, 2014 CFR

2014-07-01

... competitive, self-, or BEP employment with earnings equivalent to at least the minimum wage. (iv) Performance... earnings equivalent to at least the minimum wage, the percentage who are individuals with significant... program in competitive, self-, or BEP employment with earnings levels equivalent to at least the minimum...

34 CFR 361.84 - Performance indicators.

Code of Federal Regulations, 2013 CFR

2013-07-01

... competitive, self-, or BEP employment with earnings equivalent to at least the minimum wage. (iv) Performance... earnings equivalent to at least the minimum wage, the percentage who are individuals with significant... program in competitive, self-, or BEP employment with earnings levels equivalent to at least the minimum...

34 CFR 361.84 - Performance indicators.

Code of Federal Regulations, 2011 CFR

2011-07-01

... competitive, self-, or BEP employment with earnings equivalent to at least the minimum wage. (iv) Performance... earnings equivalent to at least the minimum wage, the percentage who are individuals with significant... program in competitive, self-, or BEP employment with earnings levels equivalent to at least the minimum...

34 CFR 361.84 - Performance indicators.

Code of Federal Regulations, 2010 CFR

2010-07-01

... competitive, self-, or BEP employment with earnings equivalent to at least the minimum wage. (iv) Performance... earnings equivalent to at least the minimum wage, the percentage who are individuals with significant... program in competitive, self-, or BEP employment with earnings levels equivalent to at least the minimum...

Toxicity of effluents from gasoline stations oil-water separators to early life stages of zebrafish Danio rerio.

PubMed

Alves, Romulo Nepomuceno; Mariz, Célio Freire; Paulo, Driele Ventura de; Carvalho, Paulo S M

2017-07-01

Used petroleum hydrocarbons and gasoline stations runoff are significant sources of polycyclic aromatic hydrocarbons (PAHs) to aquatic ecosystems. Samples of the final effluent of oil-water-separators were collected at gasoline stations in the metropolitan region of Recife, Brazil, before release to sewage or rainwater systems. Effluent soluble fractions (ESF) were prepared and bioassays were performed according to the Fish Embryo Toxicity Test. The test involved exposing zebrafish Danio rerio embryos to dilutions of the ESFs for 96 h, with daily examination of lethality and sublethal morphological effects integrated through the General Morphology Score (GMS), based on the achievement of developmental hallmarks. Frequencies of abnormalities were recorded after exposures. ESF LC50-96h (lethal concentration to 50% of exposed embryos) in the most toxic effluent achieved 8.9% (v/v), equivalent to 11 μg phenanthrene equivalents L -1 . GMS scores indicated significantly delayed embryo-larval development at ESF dilutions of 10% and 20% from effluents of all gas stations. Major abnormalities detected after the 96 h exposure included the presence of a yolk sac not fully absorbed coupled with the lack of an inflated swim bladder, lack of both pectoral fins, and the failure to develop a protruding mouth. Effective equivalent PAH concentrations that induce a 50% frequency of larvae without an inflated swim bladder (EC50) were 4.9 μg phenanthrene L -1 , 21.8 μg naphthalene L -1 , and 34.1 μg chrysene L -1 . This study shows that PAHs in ESFs from gas stations oil water separators are toxic to zebrafish, contributing to the toxicity of urban storm waters. Copyright © 2017 Elsevier Ltd. All rights reserved.

Towards Testing General Relativity with a dual species interferometer

NASA Astrophysics Data System (ADS)

Schlippert, Dennis; Hartwig, Jonas; Tiarks, Daniel; Velte, Ulrich; Ganske, Sven; Ertmer, Wolfgang; Rasel, Ernst M.

2012-06-01

We report on our work directed towards a dual species matter-wave interferometer for performing a differential measurement of the acceleration of free falling ^87Rb and ^39K atoms to test Einstein's equivalence principle (universality of free fall). Based on minimal Standard Model Extension calculations this combination of test masses is more sensitive to composition based equivalence principle violating effects than, e.g. ^85Rb-^87Rb. During free fall, a Mach-Zehnder type interferometry sequence employing stimulated Raman transitions is applied synchronously for both species, achieving high common noise rejection. With an expected single shot resolution of 5x10-8g the apparatus will allow for studying systematics at the 10-9g level after 100 s integration time. Post-correction methods for high vibrational noise environments are investigated. To assure well defined starting conditions the two species will be trapped in an optical dipole trap. The properties of this trap at 2 μm allow for fast and efficient laser cooling, use of evaporative and sympathetic cooling techniques is possible. We will show the enviromental noise limited performance of the single species Rb gravimeter and the progress of the implementation of the K gravimeter.

A new performance index for the repetitive motion of mobile manipulators.

PubMed

Xiao, Lin; Zhang, Yunong

2014-02-01

A mobile manipulator is a robotic device composed of a mobile platform and a stationary manipulator fixed to the platform. To achieve the repetitive motion control of mobile manipulators, the mobile platform and the manipulator have to realize the repetitive motion simultaneously. To do so, a novel quadratic performance index is, for the first time, designed and presented in this paper, of which the effectiveness is analyzed by following a neural dynamics method. Then, a repetitive motion scheme is proposed by combining the criterion, physical constraints, and integrated kinematical equations of mobile manipulators, which is further reformulated as a quadratic programming (QP) subject to equality and bound constraints. In addition, two important Bridge theorems are established to prove that such a QP can be converted equivalently into a linear variational inequality, and then equivalently into a piecewise-linear projection equation (PLPE). A real-time numerical algorithm based on PLPE is thus developed and applied for the online solution of the resultant QP. Two tracking-path tasks demonstrate the effectiveness and accuracy of the repetitive motion scheme. In addition, comparisons between the nonrepetitive and repetitive motion further validate the superiority and novelty of the proposed scheme.

Diabetes and hypertension care among male prisoners in Mexico City: exploring transition of care and the equivalence principle.

PubMed

Silverman-Retana, Omar; Servan-Mori, Edson; Lopez-Ridaura, Ruy; Bautista-Arredondo, Sergio

2016-07-01

To document the performance of diabetes and hypertension care in two large male prisons in Mexico City. We analyzed data from a cross-sectional study carried out during July-September 2010, including 496 prisoners with hypertension or diabetes in Mexico City. Bivariate and multivariable logistic regressions were used to assess process-of-care indicators and disease control status. Hypertension and diabetes prevalence were estimated on 2.1 and 1.4 %, respectively. Among prisoners with diabetes 22.7 % (n = 62) had hypertension as comorbidity. Low achievement of process-of-care indicators-follow-up visits, blood pressure and laboratory assessments-were observed during incarceration compared to the same prisoners in the year prior to incarceration. In contrast to nonimprisoned diabetes population from Mexico City and from the lowest quintile of socioeconomic status at the national level, prisoners with diabetes had the lowest performance on process-of-care indicators. Continuity of care for chronic diseases, coupled with the equivalence of care principle, should provide the basis for designing chronic disease health policy for prisoners, with the goal of consistent transition of care from community to prison and vice versa.

Increasing Flexibility in Energy Code Compliance: Performance Packages

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

Hart, Philip R.; Rosenberg, Michael I.

Energy codes and standards have provided significant increases in building efficiency over the last 38 years, since the first national energy code was published in late 1975. The most commonly used path in energy codes, the prescriptive path, appears to be reaching a point of diminishing returns. As the code matures, the prescriptive path becomes more complicated, and also more restrictive. It is likely that an approach that considers the building as an integrated system will be necessary to achieve the next real gains in building efficiency. Performance code paths are increasing in popularity; however, there remains a significant designmore » team overhead in following the performance path, especially for smaller buildings. This paper focuses on development of one alternative format, prescriptive packages. A method to develop building-specific prescriptive packages is reviewed based on a multiple runs of prototypical building models that are used to develop parametric decision analysis to determines a set of packages with equivalent energy performance. The approach is designed to be cost-effective and flexible for the design team while achieving a desired level of energy efficiency performance. A demonstration of the approach based on mid-sized office buildings with two HVAC system types is shown along with a discussion of potential applicability in the energy code process.« less

Applying the Interaction Equivalency Theorem to Online Courses in a Large Organization

ERIC Educational Resources Information Center

Rodriguez, Brenda Cecilia Padilla; Armellini, Alejandro

2014-01-01

Finding effective ways of designing online courses is a priority for corporate organizations. The interaction equivalency theorem states that meaningful learning can be achieved as long as courses are designed with at least a high level of one of three types of interactions (learner-content, learner-teacher or learner-learner). This study aimed to…

76 FR 18822 - Qualification of Drivers; Exemption Applications; Epilepsy and Seizure Disorders

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-05

... of safety that is equivalent to, or greater than, the level that would be achieved absent such... episode of a non-epileptic seizure or loss of consciousness of unknown cause which did not require anti... equivalent to the level of safety obtained by complying with the regulation because he has remained seizure...

75 FR 72869 - Qualification of Drivers; Exemption Renewals; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-26

... exemptions will provide a level of safety that will be equivalent to, or greater than, the level of safety... if it finds ``such exemption would likely achieve a level of safety that is equivalent to, or greater... conditions of the exemption; (2) the exemption has resulted in a lower level of safety than was maintained...

78 FR 34140 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-06

... exemption renewals will provide a level of safety that is equivalent to or greater than the level of safety... finds ``such exemption would likely achieve a level of safety that is equivalent to or greater than the... exemption has resulted in a lower level of safety than was maintained before it was granted; or (3...

The Impact of Learning Styles on Student Achievement in a Web-Based versus an Equivalent Face-to-Face Course

ERIC Educational Resources Information Center

Zacharis, Nick Z.

2010-01-01

This study investigated the relationship between students' learning styles and their achievement in two different learning environments: online instruction and traditional instruction. The results indicated that a) students in the traditional learning group had higher, but not statistically significant higher, levels of achievement than students…

Academic Achievement of LEP Students After Reclassification: A Southern California Study.

ERIC Educational Resources Information Center

Nava-Hamaker, Mary Lou

Gains and grade level achievement in Total Reading and Language of four groups of fifth grade students, including LEP (Limited English Proficient) students, in SES (socioeconomic status) 1 and SES 2 schools were compared to determine whether the students were achieving at grade level in reading and at an equivalent level in language. Groups from…

Programmable logic construction kits for hyper-real-time neuronal modeling.

PubMed

Guerrero-Rivera, Ruben; Morrison, Abigail; Diesmann, Markus; Pearce, Tim C

2006-11-01

Programmable logic designs are presented that achieve exact integration of leaky integrate-and-fire soma and dynamical synapse neuronal models and incorporate spike-time dependent plasticity and axonal delays. Highly accurate numerical performance has been achieved by modifying simpler forward-Euler-based circuitry requiring minimal circuit allocation, which, as we show, behaves equivalently to exact integration. These designs have been implemented and simulated at the behavioral and physical device levels, demonstrating close agreement with both numerical and analytical results. By exploiting finely grained parallelism and single clock cycle numerical iteration, these designs achieve simulation speeds at least five orders of magnitude faster than the nervous system, termed here hyper-real-time operation, when deployed on commercially available field-programmable gate array (FPGA) devices. Taken together, our designs form a programmable logic construction kit of commonly used neuronal model elements that supports the building of large and complex architectures of spiking neuron networks for real-time neuromorphic implementation, neurophysiological interfacing, or efficient parameter space investigations.

Comparison of Pharmaceutical Calculations Learning Outcomes Achieved Within a Traditional Lecture or Flipped Classroom Andragogy.

PubMed

Anderson, H Glenn; Frazier, Lisa; Anderson, Stephanie L; Stanton, Robert; Gillette, Chris; Broedel-Zaugg, Kim; Yingling, Kevin

2017-05-01

Objective. To compare learning outcomes achieved from a pharmaceutical calculations course taught in a traditional lecture (lecture model) and a flipped classroom (flipped model). Methods. Students were randomly assigned to the lecture model and the flipped model. Course instructors, content, assessments, and instructional time for both models were equivalent. Overall group performance and pass rates on a standardized assessment (Pcalc OSCE) were compared at six weeks and at six months post-course completion. Results. Student mean exam scores in the flipped model were higher than those in the lecture model at six weeks and six months later. Significantly more students passed the OSCE the first time in the flipped model at six weeks; however, this effect was not maintained at six months. Conclusion. Within a 6 week course of study, use of a flipped classroom improves student pharmacy calculation skill achievement relative to a traditional lecture andragogy. Further study is needed to determine if the effect is maintained over time.

Comparison of Pharmaceutical Calculations Learning Outcomes Achieved Within a Traditional Lecture or Flipped Classroom Andragogy

PubMed Central

Frazier, Lisa; Anderson, Stephanie L.; Stanton, Robert; Gillette, Chris; Broedel-Zaugg, Kim; Yingling, Kevin

2017-01-01

Objective. To compare learning outcomes achieved from a pharmaceutical calculations course taught in a traditional lecture (lecture model) and a flipped classroom (flipped model). Methods. Students were randomly assigned to the lecture model and the flipped model. Course instructors, content, assessments, and instructional time for both models were equivalent. Overall group performance and pass rates on a standardized assessment (Pcalc OSCE) were compared at six weeks and at six months post-course completion. Results. Student mean exam scores in the flipped model were higher than those in the lecture model at six weeks and six months later. Significantly more students passed the OSCE the first time in the flipped model at six weeks; however, this effect was not maintained at six months. Conclusion. Within a 6 week course of study, use of a flipped classroom improves student pharmacy calculation skill achievement relative to a traditional lecture andragogy. Further study is needed to determine if the effect is maintained over time. PMID:28630511

The addition of tramadol as a second opioid may improve pain relief in severe osteoarthritis: a prospective study.

PubMed

Di Lorenzo, Luigi; Foti, Calogero; Forte, Alfonso Maria; Palmieri, Enzo; Formisano, Rita; Vatakencherry, Abraham; Pappagallo, Marco

2010-01-01

Opioid combination has been shown to reduce the need for escalating doses for the treatment of cancer pain. A prospective study was planned to evaluate the addition of tramadol to a stronger opioid for the treatment of severe pain as a result of osteoarthritis, previously uncontrolled by non-opioid analgesics or weak opioids. All subjects received tramadol 200 mg and tizanidine 2 mg. At 2 weeks, tramadol was discontinued for patients still reporting poor pain relief (effectiveness ≤50%), and a stronger opioid was titrated to a morphine equivalent amount (MEA) of 40-60 mg orally. After two additional weeks, patients were then divided into two groups: the Strong Opioid Group (SO) and the Tramadol plus the Strong Opioid Group (TSO). The SO group was allowed to escalate opioid dose for lack of effectiveness; the TSO group received tramadol 150 mg daily, thereafter additional strong opioid titration was allowed. A total of 74 patients were studied: SO (n = 40) and TSOG (n = 34). All patients eventually achieved pain relief quality, with both groups reporting similar Karnofsky Performance Scale effectiveness. The SO group achieved satisfactory pain relief (>50%) at an average daily oral MEA of 120 mg. TSO subjects achieved satisfactory pain relief (>50%) at an average daily oral MEA of 95 mg. The addition of tramadol provided a synergistic effect resulting in a 30-mg decrease in necessary morphine equivalents with fewer opioid-related adverse effects. © 2010 The Authors. Pain Practice © 2010 World Institute of Pain.

Tuning the Perfluorosulfonic Acid Membrane Morphology for Vanadium Redox-Flow Batteries.

PubMed

Vijayakumar, M; Luo, Qingtao; Lloyd, Ralph; Nie, Zimin; Wei, Xiaoliang; Li, Bin; Sprenkle, Vincent; Londono, J-David; Unlu, Murat; Wang, Wei

2016-12-21

The microstructure of perfluorinated sulfonic acid proton-exchange membranes such as Nafion significantly affects their transport properties and performance in a vanadium redox-flow battery (VRB). In this work, Nafion membranes with various equivalent weights ranging from 1000 to 1500 are prepared and the morphology-property-performance relationship is investigated. NMR and small-angle X-ray scattering studies revealed their composition and morphology variances, which lead to major differences in key transport properties related to proton conduction and vanadium-ion permeation. Their performances are further characterized as VRB membranes. On the basis of this understanding, a new perfluorosulfonic acid membrane is designed with optimal pore geometry and thickness, leading to higher ion selectivity and lower cost compared with the widely used Nafion 115. Excellent VRB single-cell performance (89.3% energy efficiency at 50 mA·cm -2 ) was achieved along with a stable cyclical capacity over prolonged cycling.

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

Vijayakumar, M.; Luo, Qingtao; Lloyd, Ralph

The microstructure of the perfluorinated sulfonic acid proton exchange membranes such as Nafion significantly affects their transport properties and performance in a vanadium redox flow battery (VRB). In this work, Nafion membranes with various equivalent weights (EW) ranging from 1000 to 1500 are prepared and the structure-property-performance relationship is investigated. Nuclear magnetic resonance (NMR) and small-angle X-ray scattering (SAXS) studies revealed their composition and morphology variances, which lead to major differences in key transport properties related to proton conduction and vanadium ion permeation. Their performances are further characterized as VRB membranes. Based on those understanding, a new perfluorosulfonic acid membranemore » is designed with optimal pore geometry and thickness, leading to higher ion selectivity and lower cost compared with the widely used Nafion® 115. Excellent VRB single-cell performance (89.3% energy efficiency at 50mA∙cm-2) was achieved along with a stable cyclical capacity over prolonged cycling.« less

Parametric Study of Pulse-Combustor-Driven Ejectors at High-Pressure

NASA Technical Reports Server (NTRS)

Yungster, Shaye; Paxson, Daniel E.; Perkins, Hugh D.

2015-01-01

Pulse-combustor configurations developed in recent studies have demonstrated performance levels at high-pressure operating conditions comparable to those observed at atmospheric conditions. However, problems related to the way fuel was being distributed within the pulse combustor were still limiting performance. In the first part of this study, new configurations are investigated computationally aimed at improving the fuel distribution and performance of the pulse-combustor. Subsequent sections investigate the performance of various pulse-combustor driven ejector configurations operating at highpressure conditions, focusing on the effects of fuel equivalence ratio and ejector throat area. The goal is to design pulse-combustor-ejector configurations that maximize pressure gain while achieving a thermal environment acceptable to a turbine, and at the same time maintain acceptable levels of NOx emissions and flow non-uniformities. The computations presented here have demonstrated pressure gains of up to 2.8%.

Parametric Study of Pulse-Combustor-Driven Ejectors at High-Pressure

NASA Technical Reports Server (NTRS)

Yungster, Shaye; Paxson, Daniel E.; Perkins, Hugh D.

2015-01-01

Pulse-combustor configurations developed in recent studies have demonstrated performance levels at high-pressure operating conditions comparable to those observed at atmospheric conditions. However, problems related to the way fuel was being distributed within the pulse combustor were still limiting performance. In the first part of this study, new configurations are investigated computationally aimed at improving the fuel distribution and performance of the pulse-combustor. Subsequent sections investigate the performance of various pulse-combustor driven ejector configurations operating at high pressure conditions, focusing on the effects of fuel equivalence ratio and ejector throat area. The goal is to design pulse-combustor-ejector configurations that maximize pressure gain while achieving a thermal environment acceptable to a turbine, and at the same time maintain acceptable levels of NO(x) emissions and flow non-uniformities. The computations presented here have demonstrated pressure gains of up to 2.8.

Joint Frequency-Domain Equalization and Despreading for Multi-Code DS-CDMA Using Cyclic Delay Transmit Diversity

NASA Astrophysics Data System (ADS)

Yamamoto, Tetsuya; Takeda, Kazuki; Adachi, Fumiyuki

Frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion can provide a better bit error rate (BER) performance than rake combining. To further improve the BER performance, cyclic delay transmit diversity (CDTD) can be used. CDTD simultaneously transmits the same signal from different antennas after adding different cyclic delays to increase the number of equivalent propagation paths. Although a joint use of CDTD and MMSE-FDE for direct sequence code division multiple access (DS-CDMA) achieves larger frequency diversity gain, the BER performance improvement is limited by the residual inter-chip interference (ICI) after FDE. In this paper, we propose joint FDE and despreading for DS-CDMA using CDTD. Equalization and despreading are simultaneously performed in the frequency-domain to suppress the residual ICI after FDE. A theoretical conditional BER analysis is presented for the given channel condition. The BER analysis is confirmed by computer simulation.

Multigroup Monte Carlo on GPUs: Comparison of history- and event-based algorithms

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

Hamilton, Steven P.; Slattery, Stuart R.; Evans, Thomas M.

This article presents an investigation of the performance of different multigroup Monte Carlo transport algorithms on GPUs with a discussion of both history-based and event-based approaches. Several algorithmic improvements are introduced for both approaches. By modifying the history-based algorithm that is traditionally favored in CPU-based MC codes to occasionally filter out dead particles to reduce thread divergence, performance exceeds that of either the pure history-based or event-based approaches. The impacts of several algorithmic choices are discussed, including performance studies on Kepler and Pascal generation NVIDIA GPUs for fixed source and eigenvalue calculations. Single-device performance equivalent to 20–40 CPU cores onmore » the K40 GPU and 60–80 CPU cores on the P100 GPU is achieved. Last, in addition, nearly perfect multi-device parallel weak scaling is demonstrated on more than 16,000 nodes of the Titan supercomputer.« less

Multigroup Monte Carlo on GPUs: Comparison of history- and event-based algorithms

DOE PAGES

Hamilton, Steven P.; Slattery, Stuart R.; Evans, Thomas M.

2017-12-22

This article presents an investigation of the performance of different multigroup Monte Carlo transport algorithms on GPUs with a discussion of both history-based and event-based approaches. Several algorithmic improvements are introduced for both approaches. By modifying the history-based algorithm that is traditionally favored in CPU-based MC codes to occasionally filter out dead particles to reduce thread divergence, performance exceeds that of either the pure history-based or event-based approaches. The impacts of several algorithmic choices are discussed, including performance studies on Kepler and Pascal generation NVIDIA GPUs for fixed source and eigenvalue calculations. Single-device performance equivalent to 20–40 CPU cores onmore » the K40 GPU and 60–80 CPU cores on the P100 GPU is achieved. Last, in addition, nearly perfect multi-device parallel weak scaling is demonstrated on more than 16,000 nodes of the Titan supercomputer.« less

Applying Rasch analysis to evaluate measurement equivalence of different administration formats of the Activity Limitation scale of the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR).

PubMed

Twiss, J; McKenna, S P; Graham, J; Swetz, K; Sloan, J; Gomberg-Maitland, M

2016-04-09

Electronic formats of patient-reported outcome (PRO) measures are now routinely used in clinical research studies. When changing from a validated paper and pen to electronic administration it is necessary to establish their equivalence. This study reports on the value of Rasch analysis in this process. Three groups of US pulmonary hypertension (PH) patients participated. The first completed an electronic version of the CAMPHOR Activity Limitation scale (e-sample) and this was compared with two pen and paper administrated samples (pp1 and pp2). The three databases were combined and analysed for fit to the Rasch model. Equivalence was evaluated by differential item functioning (DIF) analyses. The three datasets were matched randomly in terms of sample size (n = 147). Mean age (years) and percentage of male respondents were as follows: e-sample (51.7, 16.0 %); pp1 (50.0, 14.0 %); pp2 (55.5, 40.4 %). The combined dataset achieved fit to the Rasch model. Two items showed evidence of borderline DIF. Further analyses showed the inclusion of these items had little impact on Rasch estimates indicating the DIF identified was unimportant. Differences between the performance of the electronic and pen and paper administrations of the CAMPHOR Activity Limitation scale were minor. The results were successful in showing how the Rasch model can be used to determine the equivalence of alternative formats of PRO measures.

Sustainability Base Construction Update

NASA Technical Reports Server (NTRS)

Mewhinney, Michael

2012-01-01

Construction of the new Sustainability Base Collaborative support facility, expected to become the highest performing building in the federal government continues at NASA's Ames Research Center, Moffet Field, Calif. The new building is designed to achieve a platinum rating under the leadership in Energy and Environment Design (LEED) new construction standards for environmentally sustainable construction developed by the U. S. Green Building Council, Washington, D. C. When completed by the end of 2011, the $20.6 million building will feature near zero net energy consumption, use 90 percent less potable water than conventionally build buildings of equivalent size, and will result in reduced building maintenance costs.

LHC Status and Upgrade Challenges

NASA Astrophysics Data System (ADS)

Smith, Jeffrey

2009-11-01

The Large Hadron Collider has had a trying start-up and a challenging operational future lays ahead. Critical to the machine's performance is controlling a beam of particles whose stored energy is equivalent to 80 kg of TNT. Unavoidable beam losses result in energy deposition throughout the machine and without adequate protection this power would result in quenching of the superconducting magnets. A brief overview of the machine layout and principles of operation will be reviewed including a summary of the September 2008 accident. The current status of the LHC, startup schedule and upgrade options to achieve the target luminosity will be presented.

Infrared light detection using a whispering-gallery-mode optical microcavity

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

Zhu, Jiangang, E-mail: jzhu@seas.wustl.edu, E-mail: ozdemir@seas.wustl.edu, E-mail: yang@seas.wustl.edu; Ozdemir, Sahin Kaya, E-mail: jzhu@seas.wustl.edu, E-mail: ozdemir@seas.wustl.edu, E-mail: yang@seas.wustl.edu; Yang, Lan, E-mail: jzhu@seas.wustl.edu, E-mail: ozdemir@seas.wustl.edu, E-mail: yang@seas.wustl.edu

2014-04-28

We demonstrate a thermal infrared (IR) detector based on an ultra-high-quality-factor (Q) whispering-gallery-mode (WGM) microtoroidal silica resonator and investigate its performance to detect IR radiation at 10 μm wavelength. The bandwidth and the sensitivity of the detector are dependent on the power of a probe laser and the detuning between the probe laser and the resonance frequency of the resonator. The microtoroid IR sensor achieved a noise-equivalent-power (NEP) of 7.46 nW, corresponding to an IR intensity of 0.095 mW/cm{sup 2}.

Cell-block procedure in endoscopic ultrasound-guided-fine-needle-aspiration of gastrointestinal solid neoplastic lesions

PubMed Central

Ieni, Antonio; Barresi, Valeria; Todaro, Paolo; Caruso, Rosario Alberto; Tuccari, Giovanni

2015-01-01

In the present review we have analyzed the clinical applications of endoscopic ultrasound-guided-fine-needle-aspiration (EUS-FNA) and the methodological aspects obtained by cell-block procedure (CBP) in the diagnostic approach to the gastrointestinal neoplastic pathology. CBP showed numerous advantages in comparison to the cytologic routine smears; in particular, better preservation of cell architecture, achievement of routine haematoxylin-eosin staining equivalent to histological slides and possibility to perform immunohistochemistry or molecular analyses represented the most evident reasons to choose this method. Moreover, by this approach, the differential diagnosis of solid gastrointestinal neoplasias may be more easily achieved and the background of contaminant non-neoplastic gastrointestinal avoided. Finally, biological samples collected by EUS-FNA CBP-assisted should be investigated in order to identify and quantify further potential molecular markers. PMID:26322154

Simulation of absolute amplitudes of ultrasound signals using equivalent circuits.

PubMed

Johansson, Jonny; Martinsson, Pär-Erik; Delsing, Jerker

2007-10-01

Equivalent circuits for piezoelectric devices and ultrasonic transmission media can be used to cosimulate electronics and ultrasound parts in simulators originally intended for electronics. To achieve efficient system-level optimization, it is important to simulate correct, absolute amplitude of the ultrasound signal in the system, as this determines the requirements on the electronics regarding dynamic range, circuit noise, and power consumption. This paper presents methods to achieve correct, absolute amplitude of an ultrasound signal in a simulation of a pulse-echo system using equivalent circuits. This is achieved by taking into consideration loss due to diffraction and the effect of the cable that connects the electronics and the piezoelectric transducer. The conductive loss in the transmission line that models the propagation media of the ultrasound pulse is used to model the loss due to diffraction. Results show that the simulated amplitude of the echo follows measured values well in both near and far fields, with an offset of about 10%. The use of a coaxial cable introduces inductance and capacitance that affect the amplitude of a received echo. Amplitude variations of 60% were observed when the cable length was varied between 0.07 m and 2.3 m, with simulations predicting similar variations. The high precision in the achieved results show that electronic design and system optimization can rely on system simulations alone. This will simplify the development of integrated electronics aimed at ultrasound systems.

Determination of the Oswestry Disability Index score equivalent to a "satisfactory symptom state" in patients undergoing surgery for degenerative disorders of the lumbar spine-a Spine Tango registry-based study.

PubMed

van Hooff, Miranda L; Mannion, Anne F; Staub, Lukas P; Ostelo, Raymond W J G; Fairbank, Jeremy C T

2016-10-01

The achievement of a given change score on a valid outcome instrument is commonly used to indicate whether a clinically relevant change has occurred after spine surgery. However, the achievement of such a change score can be dependent on baseline values and does not necessarily indicate whether the patient is satisfied with the current state. The achievement of an absolute score equivalent to a patient acceptable symptom state (PASS) may be a more stringent measure to indicate treatment success. This study aimed to estimate the score on the Oswestry Disability Index (ODI, version 2.1a; 0-100) corresponding to a PASS in patients who had undergone surgery for degenerative disorders of the lumbar spine. This is a cross-sectional study of diagnostic accuracy using follow-up data from an international spine surgery registry. The sample includes 1,288 patients with degenerative lumbar spine disorders who had undergone elective spine surgery, registered in the EUROSPINE Spine Tango Spine Surgery Registry. The main outcome measure was the ODI (version 2.1a). Surgical data and data from the ODI and Core Outcome Measures Index (COMI) were included to determine the ODI threshold equivalent to PASS at 1 year (±1.5 months; n=780) and 2 years (±2 months; n=508) postoperatively. The symptom-specific well-being item of the COMI was used as the external criterion in the receiver operating characteristic (ROC) analysis to determine the ODI threshold equivalent to PASS. Separate sensitivity analyses were performed based on the different definitions of an "acceptable state" and for subgroups of patients. JF is a copyright holder of the ODI. The ODI threshold for PASS was 22, irrespective of the time of follow-up (area under the curve [AUC]: 0.89 [sensitivity {Se}: 78.3%, specificity {Sp}: 82.1%] and AUC: 0.91 [Se: 80.7%, Sp: 85.6] for the 1- and 2-year follow-ups, respectively). Sensitivity analyses showed that the absolute ODI-22 threshold for the two follow-up time-points were robust. A stricter definition of PASS resulted in lower ODI thresholds, varying from 16 (AUC=0.89; Se: 80.2%, Sp: 82.0%) to 18 (AUC=0.90; Se: 82.4%, Sp: 80.4%) depending on the time of follow-up. An ODI score ≤22 indicates the achievement of an acceptable symptom state and can hence be used as a criterion of treatment success alongside the commonly used change score measures. At the individual level, the threshold could be used to indicate whether or not a patient with a lumbar spine disorder is a "responder" after elective surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

Economic and ecological outcomes of flexible biodiversity offset systems.

PubMed

Habib, Thomas J; Farr, Daniel R; Schneider, Richard R; Boutin, Stan

2013-12-01

The commonly expressed goal of biodiversity offsets is to achieve no net loss of specific biological features affected by development. However, strict equivalency requirements may complicate trading of offset credits, increase costs due to restricted offset placement options, and force offset activities to focus on features that may not represent regional conservation priorities. Using the oil sands industry of Alberta, Canada, as a case study, we evaluated the economic and ecological performance of alternative offset systems targeting either ecologically equivalent areas (vegetation types) or regional conservation priorities (caribou and the Dry Mixedwood natural subregion). Exchanging dissimilar biodiversity elements requires assessment via a generalized metric; we used an empirically derived index of biodiversity intactness to link offsets with losses incurred by development. We considered 2 offset activities: land protection, with costs estimated as the net present value of profits of petroleum and timber resources to be paid as compensation to resource tenure holders, and restoration of anthropogenic footprint, with costs estimated from existing restoration projects. We used the spatial optimization tool MARXAN to develop hypothetical offset networks that met either the equivalent-vegetation or conservation-priority targets. Networks that required offsetting equivalent vegetation cost 2-17 times more than priority-focused networks. This finding calls into question the prudence of equivalency-based systems, particularly in relatively undeveloped jurisdictions, where conservation focuses on limiting and directing future losses. Priority-focused offsets may offer benefits to industry and environmental stakeholders by allowing for lower-cost conservation of valued ecological features and may invite discussion on what land-use trade-offs are acceptable when trading biodiversity via offsets. Resultados Económicos y Ecológicos de Sistemas de Compensación de Biodiversidad Flexible Habib et al. © 2013 Society for Conservation Biology.

Assessing learning outcomes and cost effectiveness of an online sleep curriculum for medical students.

PubMed

Bandla, Hari; Franco, Rose A; Simpson, Deborah; Brennan, Kimberly; McKanry, Jennifer; Bragg, Dawn

2012-08-15

Sleep disorders are highly prevalent across all age groups but often remain undiagnosed and untreated, resulting in significant health consequences. To overcome an inadequacy of available curricula and learner and instructor time constraints, this study sought to determine if an online sleep medicine curriculum would achieve equivalent learner outcomes when compared with traditional, classroom-based, face-to-face instruction at equivalent costs. Medical students rotating on a required clinical clerkship received instruction in 4 core clinical sleep-medicine competency domains in 1 of 2 delivery formats: a single 2.5-hour face-to-face workshop or 4 asynchronous e-learning modules. Immediate learning outcomes were assessed in a subsequent clerkship using a multiple-choice examination and standardized patient station, with long-term outcomes assessed through analysis of students' patient write-ups for inclusion of sleep complaints and diagnoses before and after the intervention. Instructional costs by delivery format were tracked. Descriptive and inferential statistical analyses compared learning outcomes and costs by instructional delivery method (face-to-face versus e-learning). Face-to-face learners, compared with online learners, were more satisfied with instruction. Learning outcomes (i.e., multiple-choice examination, standardized patient encounter, patient write-up), as measured by short-term and long-term assessments, were roughly equivalent. Design, delivery, and learner-assessment costs by format were equivalent at the end of 1 year, due to higher ongoing teaching costs associated with face-to-face learning offsetting online development and delivery costs. Because short-term and long-term learner performance outcomes were roughly equivalent, based on delivery method, the cost effectiveness of online learning is an economically and educationally viable instruction platform for clinical clerkships.

Ambient Dose Equivalent measured at the Instituto Nacional de Cancerologia Department of Nuclear Medicine

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

Avila, O.; Torres-Ulloa, C. L.; Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, AP 70-542, 04510, DF

2010-12-07

Ambient dose equivalent values were determined in several sites at the Instituto Nacional de Cancerologia, Departmento de Medicina Nuclear, using TLD-100 and TLD-900 thermoluminescent dosemeters. Additionally, ambient dose equivalent was measured at a corridor outside the hospitalization room for patients treated with {sup 137}Cs brachytherapy. Dosemeter calibration was performed at the Instituto Nacional de Investigaciones Nucleares, Laboratorio de Metrologia, to known {sup 137}Cs gamma radiation air kerma. Radionuclides considered for this study are {sup 131}I, {sup 18}F, {sup 67}Ga, {sup 99m}Tc, {sup 111}In, {sup 201}Tl and {sup 137}Cs, with main gamma energies between 93 and 662 keV. Dosemeters were placedmore » during a five month period in the nuclear medicine rooms (containing gamma-cameras), injection corridor, patient waiting areas, PET/CT study room, hot lab, waste storage room and corridors next to the hospitalization rooms for patients treated with {sup 131}I and {sup 137}Cs. High dose values were found at the waste storage room, outside corridor of {sup 137}Cs brachytherapy patients and PET/CT area. Ambient dose equivalent rate obtained for the {sup 137}Cs brachytherapy corridor is equal to (18.51{+-}0.02)x10{sup -3} mSv/h. Sites with minimum doses are the gamma camera rooms, having ambient dose equivalent rates equal to (0.05{+-}0.03)x10{sup -3} mSv/h. Recommendations have been given to the Department authorities so that further actions are taken to reduce doses at high dose sites in order to comply with the ALARA principle (as low as reasonably achievable).« less

Use of Incineration Solid Waste Bottom Ash as Cement Mixture in Cement Production

NASA Astrophysics Data System (ADS)

Jun, N. H.; Abdullah, M. M. A. B.; Jin, T. S.; Kadir, A. A.; Tugui, C. A.; Sandu, A. V.

2017-06-01

Incineration solid waste bottom ash was use to examine the suitability as a substitution in cement production. This study enveloped an innovative technology option for designing new equivalent cement that contains incineration solid waste bottom ash. The compressive strength of the samples was determined at 7, 14, 28 and 90 days. The result was compared to control cement with cement mixture containing incineration waste bottom ash where the result proved that bottom ash cement mixture able achieve its equivalent performance compared to control cement which meeting the requirement of the standards according to EN 196-1. The pozzolanic activity index of bottom ash cement mixture reached 0.92 at 28 days and 0.95 at 90 and this values can be concluded as a pozzolanic material with positive pozzolanic activity. Calcium hydroxide in Portland cement decreasing with the increasing replacement of bottom ash where the reaction occur between Ca(OH)2 and active SiO2.

Toward Revealing the Critical Role of Perovskite Coverage in Highly Efficient Electron-Transport Layer-Free Perovskite Solar Cells: An Energy Band and Equivalent Circuit Model Perspective.

PubMed

Huang, Like; Xu, Jie; Sun, Xiaoxiang; Du, Yangyang; Cai, Hongkun; Ni, Jian; Li, Juan; Hu, Ziyang; Zhang, Jianjun

2016-04-20

Currently, most efficient perovskite solar cells (PVKSCs) with a p-i-n structure require simultaneously electron transport layers (ETLs) and hole transport layers (HTLs) to help collecting photogenerated electrons and holes for obtaining high performance. ETL free planar PVKSC is a relatively new and simple structured solar cell that gets rid of the complex and high temperature required ETL (such as compact and mesoporous TiO2). Here, we demonstrate the critical role of high coverage of perovskite in efficient ETL free PVKSCs from an energy band and equivalent circuit model perspective. From an electrical point of view, we confirmed that the low coverage of perovskite does cause localized short circuit of the device. With coverage optimization, a planar p-i-n(++) device with a power conversion efficiency of over 11% was achieved, implying that the ETL layer may not be necessary for an efficient device as long as the perovskite coverage is approaching 100%.

"Galileo Airborne Test Of Equivalence"-Gate

NASA Astrophysics Data System (ADS)

Nobili, A. M.; Unnikrishnan, C. S.; Suresh, D.

A differential Galileo-type mass dropping experiment named GAL was proposed at the University of Pisa in 1986 and completed at CERN in 1992 (Carusotto et al., PRL 69, 1722) in order to test the Equivalence Principle by testing the Universality of Free Fall. The free falling mass was a disk made of two half disks of different composition; a violation of equivalence would produce an angular acceleration of the disk around its symmetry axis, which was measured with a modified Michelson interferometer. GATE -``Galileo Airborne Test of Equivalence'' is a variant of that experiment to be performed in parabolic flight on-board the ``Airbus A300 Zero-g'' aircraft of the European Space Agency (ESA). The main advantages of GATE with respect to GAL are the longer time of free fall and the absence of weight in the final stage of unlocking. The longer time of fall makes the signal stronger (the signal grows quadratically with the time of fall); unlocking at zero-g can significantly reduce spurious angular accelerations of the disk due to inevitable imperfections in the locking/unlocking mechanism, which turned out to be the limiting factor in GAL. A preliminary estimate indicates that GATE should be able to achieve a sensitivity η ≡ Δ g/g≃ 10-13, an improvement by about 3 orders of magnitude with respect to GAL and by about 1 order of magnitude with respect to the best result obtained with a slowly rotating torsion balance by the ``Eöt-Wash'' group at the University of Washington. Ground tests of the read-out and of the locking/unlocking disturbances can be carried out prior to the aircraft experiment. Locking/unlocking tests, retrieval tests, as well as tests of the aircraft environment can be performed onboard the Airbus A-300 in preparation for the actual experiment. The GATE experiment can be viewed as an Equivalence Principle test of intermediate sensitivity between torsion balance ground tests (10-12), balloon or micro-satellite (150 kg) tests (GREAT and μ SCOPE: ≃ 10-15), small-satellite (300 kg) room temperature tests (GG: ≃ 10-17), large-satellite (1 ton) cryogenic tests (STEP: ≃ 10-18)

41 CFR 102-80.130 - Who must perform the equivalent level of safety analysis?

Code of Federal Regulations, 2010 CFR

2010-07-01

...-SAFETY AND ENVIRONMENTAL MANAGEMENT Accident and Fire Prevention Equivalent Level of Safety Analysis... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Who must perform the equivalent level of safety analysis? 102-80.130 Section 102-80.130 Public Contracts and Property Management...

Assessing Impact of Dual Sensor Enhanced Flight Vision Systems on Departure Performance

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Etherington, Timothy J.; Severance, Kurt; Bailey, Randall E.

2016-01-01

Synthetic Vision (SV) and Enhanced Flight Vision Systems (EFVS) may serve as game-changing technologies to meet the challenges of the Next Generation Air Transportation System and the envisioned Equivalent Visual Operations (EVO) concept - that is, the ability to achieve the safety and operational tempos of current-day Visual Flight Rules operations irrespective of the weather and visibility conditions. One significant obstacle lies in the definition of required equipage on the aircraft and on the airport to enable the EVO concept objective. A motion-base simulator experiment was conducted to evaluate the operational feasibility and pilot workload of conducting departures and approaches on runways without centerline lighting in visibility as low as 300 feet runway visual range (RVR) by use of onboard vision system technologies on a Head-Up Display (HUD) without need or reliance on natural vision. Twelve crews evaluated two methods of combining dual sensor (millimeter wave radar and forward looking infrared) EFVS imagery on pilot-flying and pilot-monitoring HUDs. In addition, the impact of adding SV to the dual sensor EFVS imagery on crew flight performance and workload was assessed. Using EFVS concepts during 300 RVR terminal operations on runways without centerline lighting appears feasible as all EFVS concepts had equivalent (or better) departure performance and landing rollout performance, without any workload penalty, than those flown with a conventional HUD to runways having centerline lighting. Adding SV imagery to EFVS concepts provided situation awareness improvements but no discernible improvements in flight path maintenance.

Impact of recycling stillage on conversion of dilute sulfuric acid pretreated corn stover to ethanol.

PubMed

Mohagheghi, Ali; Schell, Daniel J

2010-04-01

Both the current corn starch to ethanol industry and the emerging lignocellulosic biofuels industry view recycling of spent fermentation broth or stillage as a method to reduce fresh water use. The objective of this study was to understand the impact of recycling stillage on conversion of corn stover to ethanol. Sugars in a dilute-acid pretreated corn stover hydrolysate were fermented to ethanol by the glucose-xylose fermenting bacteria Zymomonas mobilis 8b. Three serial fermentations were performed at two different initial sugar concentrations using either 10% or 25% of the stillage as makeup water for the next fermentation in the series. Serial fermentations were performed to achieve near steady state concentration of inhibitors and other compounds in the corn stover hydrolysate. Little impact on ethanol yields was seen at sugar concentrations equivalent to pretreated corn stover slurry at 15% (w/w) with 10% recycle of the stillage. However, ethanol yields became progressively poorer as the sugar concentration increased and fraction of the stillage recycled increased. At an equivalent corn stover slurry concentration of 20% with 25% recycled stillage the ethanol yield was only 5%. For this microorganism with dilute-acid pretreated corn stover, recycling a large fraction of the stillage had a significant negative impact on fermentation performance. Although this finding is of concern for biochemical-based lignocellulose conversion processes, other microorganism/pretreatment technology combinations will likely perform differently. (c) 2009 Wiley Periodicals, Inc.

Tracking performance and cycle slipping in the all-digital symbol synchronizer loop of the block 5 receiver

NASA Astrophysics Data System (ADS)

Aung, M.

1992-11-01

Computer simulated noise performance of the symbol synchronizer loop (SSL) in the Block 5 receiver is compared with the theoretical noise performance. Good agreement is seen at the higher loop SNR's (SNR(sub L)'s), with gradual degradation as the SNR(sub L) is decreased. For the different cases simulated, cycle slipping is observed (within the simulation time of 10(exp 4) seconds) at SNR(sub L)'s below different thresholds, ranging from 6 to 8.5 dB, comparable to that of a classical phase-locked loop. An important point, however, is that to achieve the desired loop SNR above the seemingly low threshold to avoid cycle slipping, a large data-to-loop-noise power ratio, P(sub D)/(N(sub 0)B(sub L)), is necessary (at least 13 dB larger than the desired SNR(sub L) in the optimum case and larger otherwise). This is due to the large squaring loss (greater than or equal to 13 dB) inherent in the SSL. For the special case of symbol rates approximately equaling the loop update rate, a more accurate equivalent model accounting for an extra loop update period delay (characteristic of the SSL phase detector design) is derived. This model results in a more accurate estimation of the noise-equivalent bandwidth of the loop.

Tracking performance and cycle slipping in the all-digital symbol synchronizer loop of the block 5 receiver

NASA Technical Reports Server (NTRS)

Aung, M.

1992-01-01

Computer simulated noise performance of the symbol synchronizer loop (SSL) in the Block 5 receiver is compared with the theoretical noise performance. Good agreement is seen at the higher loop SNR's (SNR(sub L)'s), with gradual degradation as the SNR(sub L) is decreased. For the different cases simulated, cycle slipping is observed (within the simulation time of 10(exp 4) seconds) at SNR(sub L)'s below different thresholds, ranging from 6 to 8.5 dB, comparable to that of a classical phase-locked loop. An important point, however, is that to achieve the desired loop SNR above the seemingly low threshold to avoid cycle slipping, a large data-to-loop-noise power ratio, P(sub D)/(N(sub 0)B(sub L)), is necessary (at least 13 dB larger than the desired SNR(sub L) in the optimum case and larger otherwise). This is due to the large squaring loss (greater than or equal to 13 dB) inherent in the SSL. For the special case of symbol rates approximately equaling the loop update rate, a more accurate equivalent model accounting for an extra loop update period delay (characteristic of the SSL phase detector design) is derived. This model results in a more accurate estimation of the noise-equivalent bandwidth of the loop.

Performance and results of the LBNE 35 ton membrane cryostat prototype

DOE PAGES

Montanari, David; Adamowski, Mark; Hahn, Alan; ...

2015-07-15

We report on the performance and commissioning of the first membrane cryostat to be used for scientific application. The Long Baseline Neutrino Experiment (LBNE) has designed and fabricated a membrane cryostat prototype in collaboration with Ishikawajima-Harima Heavy Industries Co., Ltd. (IHI). LBNE has designed and fabricated the supporting cryogenic system infrastructure and successfully commissioned and operated the first membrane cryostat. Original goals of the prototype are: to demonstrate the membrane cryostat technology in terms of thermal performance, feasibility for liquid argon and leak tightness; to demonstrate that we can remove all the impurities from the vessel and achieve the puritymore » requirements in a membrane cryostat without evacuation; to demonstrate that we can achieve and maintain the purity requirements of the liquid argon using mol sieve and copper filters. The purity requirements of a large liquid argon detector such as LBNE are contaminants below 200 parts per trillion (ppt) oxygen equivalent. LBNE is planning the design and construction of a large liquid argon detector. This presentation will present requirements, design and construction of the LBNE 35 ton membrane cryostat prototype, and detail the commissioning and performance. The experience and results of this prototype are extremely important for the development of the LBNE detector.« less

Outcomes of LASIK and PRK in previous penetrating corneal transplant recipients.

PubMed

Kovoor, Timmy A; Mohamed, Engy; Cavanagh, H Dwight; Bowman, R Wayne

2009-09-01

To evaluate the safety and efficacy of excimer laser refractive surgery in correcting refractive error in eyes that have undergone previous penetrating keratoplasty (PK). Twenty-three keratorefractive procedures on 16 eyes from 16 consecutive subjects were evaluated between 2002 and 2008. Each patient presented a previous history of a PK with subsequent postoperative myopia and astigmatism. Keratometric value, manifest refraction, best-corrected visual acuity, uncorrected visual acuity, and complications were determined. There were a total of 14 photorefractive keratectomy (PRK) procedures performed on 11 eyes and 9 laser in situ keratomileusis (LASIK) procedures performed on 5 eyes. In the PRK group, the preoperative post-PK manifest refractive spherical equivalent and cylindrical error were -6.22 +/- 6.23 diopter and 5.23 +/- 2.26 D, respectively. The PRK postoperative manifest refractive spherical equivalent and cylindrical error were -3.61 +/- 4.23 D (P=0.25) and 3.21 +/- 1.78 D (P=0.02), respectively. In the LASIK group, the preoperative post-PK manifest refractive spherical equivalent and cylindrical error were -3.05 +/- 3.29 D and 4.11 +/- 2.38 D, respectively. The LASIK postoperative manifest refractive spherical equivalent and cylindrical error were -1.51 +/- 2.02 D (P=0.24) and 2.08 +/- 1.26 D (P=0.03), respectively. There was a 2-line or greater improvement of uncorrected visual acuity in 8 of the 14 PRK treatments and 5 of the 9 LASIK treatments. There were two episodes of acute graft rejection. One of the episodes resolved with topical and oral corticosteroids, and the other episode required a repeat corneal transplantation. PRK and LASIK are effective tools in reducing surgically induced astigmatism after penetrating corneal transplantation in most patients in this case series. The reduction of astigmatism may allow improved contact lens or spectacle fitting to achieve best-corrected binocular visual acuity.

Extending cost–benefit analysis for the sustainability impact of inter-urban Intelligent Transport Systems

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

Kolosz, Ben, E-mail: kolosz27@gmail.com; Grant-Muller, Susan, E-mail: S.M.Grant-Muller@its.leeds.ac.uk

The paper reports research involving three cost–benefit analyses performed on different ITS schemes (Active Traffic Management, Intelligent Speed Adaptation and the Automated Highway System) on one of the UK's busiest highways — the M42. The environmental scope of the assets involved is widened to take into account the possibility of new technology linked by ICT and located within multiple spatial regions. The areas focused on in the study were data centre energy emissions, the embedded emissions of the road-side infrastructure, vehicle tailpipe emissions, additional hardware required by the vehicles (if applicable) and safety, and all aspects of sustainability. Dual discountingmore » is applied which aims to provide a separate discount rate for environmental elements. For ATM, despite the energy costs of the data centre, the initial implementation costs and mitigation costs of its embedded emissions, a high cost–benefit ratio of 5.89 is achieved, although the scheme becomes less effective later on its lifecycle due to rising costs of energy. ISA and AHS generate a negative result, mainly due to the cost of getting the vehicle on the road. In order to negate these costs, the pricing of the vehicle should be scaled depending upon the technology that is outfitted. Retrofitting on vehicles without the technology should be paid for by the driver. ATM will offset greenhouse gas emissions by 99 kt of CO{sub 2} equivalency over a 25 year lifespan. This reduction has taken into account the expected improvement in vehicle technology. AHS is anticipated to save 280 kt of CO{sub 2} equivalency over 15 years of operational usage. However, this offset is largely dependent on assumptions such as the level of market penetration. - Highlights: • Three cost–benefit analyses are applied to inter-urban intelligent transport. • For ATM, a high cost–benefit ratio of 5.89 is achieved. • ATM offsets greenhouse gas emissions by 99 kt of CO{sub 2} equivalency over 25 years. • ISA and AHS generate a negative result due to vehicle implementation costs. • AHS is anticipated to save 280 kt of CO{sub 2} equivalency over 15 years.« less

40 CFR 61.353 - Alternative means of emission limitation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... for Benzene Waste Operations § 61.353 Alternative means of emission limitation. (a) If, in the Administrator's judgment, an alternative means of emission limitation will achieve a reduction in benzene emissions at least equivalent to the reduction in benzene emissions from the source achieved by the...

Comparing self-guided learning and educator-guided learning formats for simulation-based clinical training.

PubMed

Brydges, Ryan; Carnahan, Heather; Rose, Don; Dubrowski, Adam

2010-08-01

In this paper, we tested the over-arching hypothesis that progressive self-guided learning offers equivalent learning benefit vs. proficiency-based training while limiting the need to set proficiency standards. We have shown that self-guided learning is enhanced when students learn on simulators that progressively increase in fidelity during practice. Proficiency-based training, a current gold-standard training approach, requires achievement of a criterion score before students advance to the next learning level. Baccalaureate nursing students (n = 15/group) practised intravenous catheterization using simulators that differed in fidelity (i.e. students' perceived realism). Data were collected in 2008. Proficiency-based students advanced from low- to mid- to high-fidelity after achieving a proficiency criterion at each level. Progressive students self-guided their progression from low- to mid- to high-fidelity. Yoked control students followed an experimenter-defined progressive practice schedule. Open-ended students moved freely between the simulators. One week after practice, blinded experts evaluated students' skill transfer on a standardized patient simulation. Group differences were examined using analyses of variance. Proficiency-based students scored highest on the high-fidelity post-test (effect size = 1.22). An interaction effect showed that the Progressive and Open-ended groups maintained their performance from post-test to transfer test, whereas the Proficiency-based and Yoked control groups experienced a significant decrease (P < 0.05). Surprisingly, most Open-ended students (73%) chose the progressive practice schedule. Progressive training and proficiency-based training resulted in equivalent transfer test performance, suggesting that progressive students effectively self-guided when to transition between simulators. Students' preference for the progressive practice schedule indicates that educators should consider this sequence for simulation-based training.

LDL-C goal attainment in patients who remain on atorvastatin or switch to equivalent or non-equivalent doses of simvastatin: a retrospective matched cohort study in clinical practice.

PubMed

Rublee, Dale A; Burke, James P

2010-03-01

As clinical trials have shown the benefits of more intensive cholesterol control, treatment targets for low-density lipoprotein cholesterol (LDL-C) have decreased progressively. At the same time, physicians have been encouraged to contain costs by prescribing cheaper, generic statins for cholesterol management. To determine how these possibly conflicting goals are managed in clinical practice, we examined LDL-C control in patients switched from a potent, branded statin (atorvastatin) to a less potent, generic statin (simvastatin). Patients who switched from atorvastatin to simvastatin between July 2006 and January 2008 were retrospectively identified from a US medical and pharmacy claims database, and matched with controls remaining on atorvastatin. Outcomes measured were the number of switched patients receiving a simvastatin milligram dose>or=2 times their previous atorvastatin dose, changes in LDL-C levels, and percentage of patients achieving recommended LDL-C targets. All study variables were analyzed descriptively. After applying exclusion and inclusion criteria, 1048 patients who switched from atorvastatin to simvastatin and 1048 matched controls who remained on atorvastatin were included. Among the switchers, 379 (36%) received an inappropriately low dose of simvastatin (<2 times atorvastatin dose). In patients remaining on atorvastatin, mean LDL-C decreased from 105.7 mg/dL to 102.3 mg/dL after 44 weeks, whereas in switched patients, LDL-C remained similar, at 105.9 mg/dL on atorvastatin and 105.8 mg/dL on simvastatin. Before switching, when all patients were receiving atorvastatin, 67.4% of switchers and 69.9% of controls achieved recommended LDL-C targets. After switching, significantly fewer switchers than controls met LDL-C targets (69.1% vs 74.6%; P=0.005). However, among patients who switched to an equivalent dose of simvastatin (>or=2 times prior atorvastatin dose), similar proportions met LDL-C targets (72.8% vs 74.6% of controls; P=0.402), whereas among patients who switched to inappropriate non-equivalent dose of simvastatin, a significantly lower proportion met LDL-C targets (62.5% vs 74.6% of controls; P=0.001). Continuing atorvastatin was associated with lower LDL-C levels and better LDL-C target attainment compared with switching to simvastatin. Patients switched to an equivalent simvastatin dose had lower LDL-C levels and were more likely to achieve LDL-C targets than patients switched to a non-equivalent dose, suggesting physicians must consider dosage equivalence when switching statins, and should measure LDL-C and titrate statins as necessary to achieve LDL-C control.

Toward Head-Up and Head-Worn Displays for Equivalent Visual Operations

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III; Arthur, Jarvis J.; Bailey, Randall E.; Shelton, Kevin J.; Kramer, Lynda J.; Jones, Denise R.; Williams, Steven P.; Harrison, Stephanie J.; Ellis, Kyle K.

2015-01-01

A key capability envisioned for the future air transportation system is the concept of equivalent visual operations (EVO). EVO is the capability to achieve the safety of current-day Visual Flight Rules (VFR) operations and maintain the operational tempos of VFR irrespective of the weather and visibility conditions. Enhanced Flight Vision Systems (EFVS) offer a path to achieve EVO. NASA has successfully tested EFVS for commercial flight operations that has helped establish the technical merits of EFVS, without reliance on natural vision, to runways without category II/III ground-based navigation and lighting requirements. The research has tested EFVS for operations with both Head-Up Displays (HUDs) and "HUD equivalent" Head-Worn Displays (HWDs). The paper describes the EVO concept and representative NASA EFVS research that demonstrate the potential of these technologies to safely conduct operations in visibilities as low as 1000 feet Runway Visual Range (RVR). Future directions are described including efforts to enable low-visibility approach, landing, and roll-outs using EFVS under conditions as low as 300 feet RVR.

Dilute alkali pretreatment of softwood pine: A biorefinery approach.

PubMed

Safari, Ali; Karimi, Keikhosro; Shafiei, Marzieh

2017-06-01

Dilute alkali pretreatment was performed on softwood pine to maximize ethanol and biogas production via a biorefinery approach. Alkali pretreatments were performed with 0-2% w/v NaOH at 100-180°C for 1-5h. The liquid fraction of the pretreated substrates was subjected to anaerobic digestion. The solid fraction of the pretreatment was used for separate enzymatic hydrolysis and fermentation. High ethanol yields of 76.9‒78.0% were achieved by pretreatment with 2% (w/v) NaOH at 180°C. The highest biogas yield of 244mL/g volatile solid (at 25°C, 1bar) was achieved by the pretreatment with 1% (w/v) NaOH at 180°C. The highest gasoline equivalent (sum of ethanol and methane) of 197L per ton of pinewood and the lowest ethanol manufacturing cost of 0.75€/L was obtained after pretreatment with 1% NaOH at 180°C for 5h. The manufacturing cost of ethanol from untreated wood was 4.12€/L. Copyright © 2017 Elsevier Ltd. All rights reserved.

Performance study of highly efficient 520 W average power long pulse ceramic Nd:YAG rod laser

NASA Astrophysics Data System (ADS)

Choubey, Ambar; Vishwakarma, S. C.; Ali, Sabir; Jain, R. K.; Upadhyaya, B. N.; Oak, S. M.

2013-10-01

We report the performance study of a 2% atomic doped ceramic Nd:YAG rod for long pulse laser operation in the millisecond regime with pulse duration in the range of 0.5-20 ms. A maximum average output power of 520 W with 180 J maximum pulse energy has been achieved with a slope efficiency of 5.4% using a dual rod configuration, which is the highest for typical lamp pumped ceramic Nd:YAG lasers. The laser output characteristics of the ceramic Nd:YAG rod were revealed to be nearly equivalent or superior to those of high-quality single crystal Nd:YAG rod. The laser pump chamber and resonator were designed and optimized to achieve a high efficiency and good beam quality with a beam parameter product of 16 mm mrad (M2˜47). The laser output beam was efficiently coupled through a 400 μm core diameter optical fiber with 90% overall transmission efficiency. This ceramic Nd:YAG laser will be useful for various material processing applications in industry.

Application of p-i-n photodiodes to charged particle fluence measurements beyond 1015 1-MeV-neutron-equivalent/cm2

NASA Astrophysics Data System (ADS)

Hoeferkamp, M. R.; Grummer, A.; Rajen, I.; Seidel, S.

2018-05-01

Methods are developed for the application of forward biased p-i-n photodiodes to measurements of charged particle fluence beyond 1015 1-MeV-neutron-equivalent/cm2. An order of magnitude extension of the regime where forward voltage can be used to infer fluence is achieved for OSRAM BPW34F devices.

Bacteriological Efficacies of Three Macrolides Compared with Those of Amoxicillin-Clavulanate against Streptococcus pneumoniae and Haemophilus influenzae

PubMed Central

Berry, Valerie; Thorburn, Christine E.; Knott, Sarah J.; Woodnutt, Gary

1998-01-01

Comparative antibacterial efficacies of erythromycin, clarithromycin, and azithromycin were examined against Streptococcus pneumoniae and Haemophilus influenzae, with amoxicillin-clavulanate used as the active control. In vitro, the macrolides at twice their MICs and at concentrations achieved in humans were bacteriostatic or reduced the numbers of viable S. pneumoniae slowly, whereas amoxicillin-clavulanate showed a rapid antibacterial effect. Against H. influenzae, erythromycin, clarithromycin, and clarithromycin plus 14-hydroxy clarithromycin at twice their MICs produced a slow reduction in bacterial numbers, whereas azithromycin was bactericidal. Azithromycin at the concentrations achieved in the serum of humans was bacteriostatic, whereas erythromycin and clarithromycin were ineffective. In experimental respiratory tract infections in rats, clarithromycin (equivalent to 250 mg twice daily [b.i.d.]) and amoxicillin-clavulanate (equivalent to 500 plus 125 mg b.i.d., respectively) were highly effective against S. pneumoniae, but azithromycin (equivalent to 500 and 250 mg once daily) was significantly less effective (P < 0.01). Against H. influenzae, clarithromycin treatment (equivalent to 250 or 500 mg b.i.d.) was similar to no treatment and was significantly less effective than amoxicillin-clavulanate treatment (P < 0.01). Azithromycin demonstrated significant in vivo activity (P < 0.05) but was significantly less effective than amoxicillin-clavulanate (P < 0.05). Overall, amoxicillin-clavulanate was effective in vitro and in vivo. Clarithromycin and erythromycin were ineffective in vitro and in vivo against H. influenzae, and azithromycin (at concentrations achieved in humans) showed unreliable activity against both pathogens. These results may have clinical implications for the utility of macrolides in the empiric therapy of respiratory tract infections. PMID:9835514

CONEDEP: COnvolutional Neural network based Earthquake DEtection and Phase Picking

NASA Astrophysics Data System (ADS)

Zhou, Y.; Huang, Y.; Yue, H.; Zhou, S.; An, S.; Yun, N.

2017-12-01

We developed an automatic local earthquake detection and phase picking algorithm based on Fully Convolutional Neural network (FCN). The FCN algorithm detects and segments certain features (phases) in 3 component seismograms to realize efficient picking. We use STA/LTA algorithm and template matching algorithm to construct the training set from seismograms recorded 1 month before and after the Wenchuan earthquake. Precise P and S phases are identified and labeled to construct the training set. Noise data are produced by combining back-ground noise and artificial synthetic noise to form the equivalent scale of noise set as the signal set. Training is performed on GPUs to achieve efficient convergence. Our algorithm has significantly improved performance in terms of the detection rate and precision in comparison with STA/LTA and template matching algorithms.

Design and experimentally measure a high performance metamaterial filter

NASA Astrophysics Data System (ADS)

Xu, Ya-wen; Xu, Jing-cheng

2018-03-01

Metamaterial filter is a kind of expecting optoelectronic device. In this paper, a metal/dielectric/metal (M/D/M) structure metamaterial filter is simulated and measured. Simulated results indicate that the perfect impedance matching condition between the metamaterial filter and the free space leads to the transmission band. Measured results show that the proposed metamaterial filter achieves high performance transmission on TM and TE polarization directions. Moreover, the high transmission rate is also can be obtained when the incident angle reaches to 45°. Further measured results show that the transmission band can be expanded through optimizing structural parameters. The central frequency of the transmission band is also can be adjusted through optimizing structural parameters. The physical mechanism behind the central frequency shifted is solved through establishing an equivalent resonant circuit model.

Effect of Direct Teaching Method on the Academic Achievement of High and Low Achievers in the Subject of English at the Secondary Level

ERIC Educational Resources Information Center

Hussain, Ishtiaq; Hamdani, Syed Nisar Hussain; Quraishi, Uzma; Zeeshan, Muhammad

2010-01-01

The major objective of the study was to determine the role of the direct teaching method in the academic achievement of students in English at the secondary level. To achieve the said objective, the Solomon Four-Design pre-test/post-test equivalent group design was considered to be the most useful design for this study. The pre-test was used to…

Theoretical Analysis and Design of Ultrathin Broadband Optically Transparent Microwave Metamaterial Absorbers

PubMed Central

Deng, Ruixiang; Li, Meiling; Muneer, Badar; Zhu, Qi; Shi, Zaiying; Song, Lixin; Zhang, Tao

2018-01-01

Optically Transparent Microwave Metamaterial Absorber (OTMMA) is of significant use in both civil and military field. In this paper, equivalent circuit model is adopted as springboard to navigate the design of OTMMA. The physical model and absorption mechanisms of ideal lightweight ultrathin OTMMA are comprehensively researched. Both the theoretical value of equivalent resistance and the quantitative relation between the equivalent inductance and equivalent capacitance are derived for design. Frequency-dependent characteristics of theoretical equivalent resistance are also investigated. Based on these theoretical works, an effective and controllable design approach is proposed. To validate the approach, a wideband OTMMA is designed, fabricated, analyzed and tested. The results reveal that high absorption more than 90% can be achieved in the whole 6~18 GHz band. The fabricated OTMMA also has an optical transparency up to 78% at 600 nm and is much thinner and lighter than its counterparts. PMID:29324686

Theoretical Analysis and Design of Ultrathin Broadband Optically Transparent Microwave Metamaterial Absorbers.

PubMed

Deng, Ruixiang; Li, Meiling; Muneer, Badar; Zhu, Qi; Shi, Zaiying; Song, Lixin; Zhang, Tao

2018-01-11

Optically Transparent Microwave Metamaterial Absorber (OTMMA) is of significant use in both civil and military field. In this paper, equivalent circuit model is adopted as springboard to navigate the design of OTMMA. The physical model and absorption mechanisms of ideal lightweight ultrathin OTMMA are comprehensively researched. Both the theoretical value of equivalent resistance and the quantitative relation between the equivalent inductance and equivalent capacitance are derived for design. Frequency-dependent characteristics of theoretical equivalent resistance are also investigated. Based on these theoretical works, an effective and controllable design approach is proposed. To validate the approach, a wideband OTMMA is designed, fabricated, analyzed and tested. The results reveal that high absorption more than 90% can be achieved in the whole 6~18 GHz band. The fabricated OTMMA also has an optical transparency up to 78% at 600 nm and is much thinner and lighter than its counterparts.

Impulse response measurement in the HgCdTe avalanche photodiode

NASA Astrophysics Data System (ADS)

Singh, Anand; Pal, Ravinder

2018-04-01

HgCdTe based mid-wave infrared focal plane arrays (MWIR FPAs) are being developed for high resolution imaging and range determination of distant camouflaged targets. Effect of bandgap grading on the response time in the n+/ν/p+ HgCdTe electron avalanche photodiode (e-APD) is evaluated using impulse response measurement. Gain normalized dark current density of 2 × 10-9 A/cm2 at low reverse bias for passive mode and 2 × 10-4 A/cm2 at -8 V for active mode is measured in the fabricated APD device, yielding high gain bandwidth product of 2.4 THZ at the maximum gain. Diffusion of carriers is minimized to achieve transit time limited impulse response by introducing composition grading in the HgCdTe epilayer. The noise equivalent photon performance less than one is achievable in the FPA that is suitable for active cum passive imaging applications.

The Evolution of Plate and Extruded Products with High Strength and Fracture Toughness

NASA Astrophysics Data System (ADS)

Denzer, D. K.; Rioja, R. J.; Bray, G. H.; Venema, G. B.; Colvin, E. L.

From the first use of 2017-T74 on the Junkers F13, improvements have been made to plate and extruded products for applications requiring the highest attainable strength and adequate fracture toughness. One such application is the upper wing of large aircraft. The progression of these product improvements achieved through the development of alloys that include 7075-(T6 & T76), 7150-(T6 & T77) and 7055-(T77 & T79) and most recently 7255-(T77 & T79) is reviewed. The most current advancements include aluminum-copper-lithium, alloy 2055 plate and extruded products that can attain strength equivalent to that of 7055-T77 with higher modulus, similar fracture toughness and improved fatigue, fatigue crack growth and corrosion performance. The achievement of these properties is explained in terms of the several alloy design principles. The highly desired and balanced characteristics make these products ideal for upper wing applications.

Prediction-based sampled-data H∞ controller design for attitude stabilisation of a rigid spacecraft with disturbances

NASA Astrophysics Data System (ADS)

Zhu, Baolong; Zhang, Zhiping; Zhou, Ding; Ma, Jie; Li, Shunli

2017-08-01

This paper investigates the H∞ control problem of the attitude stabilisation of a rigid spacecraft with external disturbances using prediction-based sampled-data control strategy. Aiming to achieve a 'virtual' closed-loop system, a type of parameterised sampled-data controller is designed by introducing a prediction mechanism. The resultant closed-loop system is equivalent to a hybrid system featured by a continuous-time and an impulsive differential system. By using a time-varying Lyapunov functional, a generalised bounded real lemma (GBRL) is first established for a kind of impulsive differential system. Based on this GBRL and Lyapunov functional approach, a sufficient condition is derived to guarantee the closed-loop system to be asymptotically stable and to achieve a prescribed H∞ performance. In addition, the controller parameter tuning is cast into a convex optimisation problem. Simulation and comparative results are provided to illustrate the effectiveness of the developed control scheme.

Two-stage combustion for reducing pollutant emissions from gas turbine combustors

NASA Technical Reports Server (NTRS)

Clayton, R. M.; Lewis, D. H.

1981-01-01

Combustion and emission results are presented for a premix combustor fueled with admixtures of JP5 with neat H2 and of JP5 with simulated partial-oxidation product gas. The combustor was operated with inlet-air state conditions typical of cruise power for high performance aviation engines. Ultralow NOx, CO and HC emissions and extended lean burning limits were achieved simultaneously. Laboratory scale studies of the non-catalyzed rich-burning characteristics of several paraffin-series hydrocarbon fuels and of JP5 showed sooting limits at equivalence ratios of about 2.0 and that in order to achieve very rich sootless burning it is necessary to premix the reactants thoroughly and to use high levels of air preheat. The application of two-stage combustion for the reduction of fuel NOx was reviewed. An experimental combustor designed and constructed for two-stage combustion experiments is described.

Cryocooled terahertz photoconductive detector system with background-limited performance in 1.5–4 THz frequency range

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

Aoki, Makoto; Hiromoto, Norihisa, E-mail: dnhirom@ipc.shizuoka.ac

2015-10-15

We describe a 4-K-cryocooled dual-band terahertz (THz) photoconductive detector system with background-limited performance. The detector system comprises two THz photoconductive detectors covering a response in a wide frequency range from 1.5 to 4 THz, low noise amplifiers, optical low-pass filters to eliminate input radiation of higher frequencies, and a mechanical 4 K Gifford-McMahon refrigerator that provides practical and convenient operation without a liquid He container. The electrical and optical performances of the THz detector system were evaluated at a detector temperature of 4 K under 300 K background radiation. We proved that the detector system can achieve background-limited noise-equivalent-power onmore » the order of 10{sup −14} W/Hz{sup 1/2} in the frequency range from 1.5 to 4 THz even if the vibration noise of the mechanical refrigerator is present.« less

Cryocooled terahertz photoconductive detector system with background-limited performance in 1.5-4 THz frequency range.

PubMed

Aoki, Makoto; Hiromoto, Norihisa

2015-10-01

We describe a 4-K-cryocooled dual-band terahertz (THz) photoconductive detector system with background-limited performance. The detector system comprises two THz photoconductive detectors covering a response in a wide frequency range from 1.5 to 4 THz, low noise amplifiers, optical low-pass filters to eliminate input radiation of higher frequencies, and a mechanical 4 K Gifford-McMahon refrigerator that provides practical and convenient operation without a liquid He container. The electrical and optical performances of the THz detector system were evaluated at a detector temperature of 4 K under 300 K background radiation. We proved that the detector system can achieve background-limited noise-equivalent-power on the order of 10(-14) W/Hz(1/2) in the frequency range from 1.5 to 4 THz even if the vibration noise of the mechanical refrigerator is present.

Advancing our thinking in presence-only and used-available analysis.

PubMed

Warton, David; Aarts, Geert

2013-11-01

1. The problems of analysing used-available data and presence-only data are equivalent, and this paper uses this equivalence as a platform for exploring opportunities for advancing analysis methodology. 2. We suggest some potential methodological advances in used-available analysis, made possible via lessons learnt in the presence-only literature, for example, using modern methods to improve predictive performance. We also consider the converse - potential advances in presence-only analysis inspired by used-available methodology. 3. Notwithstanding these potential advances in methodology, perhaps a greater opportunity is in advancing our thinking about how to apply a given method to a particular data set. 4. It is shown by example that strikingly different results can be achieved for a single data set by applying a given method of analysis in different ways - hence having chosen a method of analysis, the next step of working out how to apply it is critical to performance. 5. We review some key issues to consider in deciding how to apply an analysis method: apply the method in a manner that reflects the study design; consider data properties; and use diagnostic tools to assess how reasonable a given analysis is for the data at hand. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

Effectiveness of treatment apnea-hypopnea index: a mathematical estimate of the true apnea-hypopnea index in the home setting.

PubMed

Boyd, Scott B; Walters, Arthur S

2013-02-01

To present a new measurement instrument, the Effectiveness of Treatment Apnea-Hypopnea Index (ET-AHI), which the authors developed to determine an estimate of the therapeutic control of obstructive sleep apnea (OSA). The authors retrospectively evaluated a cohort of patients with OSA who initially attempted to use continuous positive airway pressure (CPAP) therapy and subsequently underwent maxillomandibular advancement (MMA) surgery. The ET-AHI calculations were performed to estimate the level of CPAP adherence that would be necessary to achieve equivalence with the MMA surgical result and to reach effective AHIs of 5 and 15. The sample was composed of 37 adult patients (mean age, 44.2 ± 9.0 yr; 73% men) with moderate to severe OSA (baseline AHI, 56.3 ± 22.6). CPAP therapy was highly efficacious (CPAP titration AHI, 4.3 ± 5.9), but no patient could adequately adhere to treatment. MMA produced a significant decrease in OSA (AHI after MMA, 11.6 ± 7.4). The ET-AHI calculations predicted that an 86% adherence rate with CPAP would be necessary to achieve equivalence with MMA, whereas adherence rates of 99% and 79% may be required to achieve effective AHIs of 5 and 15, respectively. The ET-AHI has the potential to significantly affect the care of patients with OSA because it may provide the treating clinician with a valuable tool to estimate the control of OSA for any therapeutic intervention. How closely the ET-AHI predicts the true effective AHI in the home setting requires further validation. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Comparison of a hydrogel corneal inlay and monovision laser in situ keratomileusis in presbyopic patients: focus on visual performance and optical quality.

PubMed

Verdoorn, Cornelis

2017-01-01

To compare the visual performance and optical quality after Raindrop Near Vision Inlay implantation or monovision LASIK for the correction of presbyopia. In this retrospective case-series study, patients previously treated in the nondominant eye with monovision LASIK were compared with patients previously implanted with Raindrop Near Vision Inlay. The study enrolled 16 inlay and 15 monovision LASIK patients. Uncorrected near visual acuity, uncorrected distance visual acuity, binocular stereopsis, patient satisfaction, and patient task performance were assessed. Postoperatively, the mean spherical equivalent was -0.66 D (0.78 SD) for the inlay group and -1.03 D (0.56 SD) for the monovision LASIK group. Monocularly, at uncorrected near distances, 60% of inlay patients and 47% of monovision LASIK patients achieved ≥20/20. Monocularly, at uncorrected far distances, 75% of inlay patients and 40% of monovision LASIK patients achieved ≥20/32 vision. Binocularly, at near distances, 79% of inlay patients and 53% of monovision LASIK patients obtained ≥20/20 vision. All patients achieved ≥20/20 binocularly for distance. On average, inlay patients obtained 98 seconds of arc and monovision LASIK patients obtained 286 seconds of arc for stereopsis. Most (79%) of the inlay patients and 66% of monovision LASIK patients were satisfied with their near vision, while 86% of inlay patients and 67% of monovision LASIK patients were satisfied with their distance vision. Patients receiving corneal inlays demonstrated better near and distance visual acuities, binocular stereopsis, task performance, and satisfaction, when compared to patients treated with monovision LASIK.

Formulation/cure technology for ultrahigh molecular weight silphenylene-siloxane polymers

NASA Technical Reports Server (NTRS)

Hundley, N. H.; Patterson, W. J.

1985-01-01

Molecular weights above one million were achieved for methylvinylsilphenylene-siloxane terpolymers using a two-stage polymerization technique which was successfully scaled up to 200 grams. The resulting polymer was vulcanized by two different formulations and compared to an identically formulated commercial methylvinyl silicone on the basis of ultimate strength, Young's modulus, percent elongation at failure, and tear strength. Relative thermal/oxidative stabilities of the elastomers were assessed by gradient and isothermal thermogravimetric analyses performed in both air and nitrogen. The experimental elastomer exhibited enhanced thermal/oxidative stability and possed equivalent or superior mechanical properties. The effect of variations in prepolymer molecular weight on mechanical properties was also investigated.

Verifying the Modal Logic Cube Is an Easy Task (For Higher-Order Automated Reasoners)

NASA Astrophysics Data System (ADS)

Benzmüller, Christoph

Prominent logics, including quantified multimodal logics, can be elegantly embedded in simple type theory (classical higher-order logic). Furthermore, off-the-shelf reasoning systems for simple type type theory exist that can be uniformly employed for reasoning within and about embedded logics. In this paper we focus on reasoning about modal logics and exploit our framework for the automated verification of inclusion and equivalence relations between them. Related work has applied first-order automated theorem provers for the task. Our solution achieves significant improvements, most notably, with respect to elegance and simplicity of the problem encodings as well as with respect to automation performance.

40 CFR Table F-1 to Subpart F of... - Performance Specifications for PM 2.5 Class II Equivalent Samplers

Code of Federal Regulations, 2013 CFR

2013-07-01

... II Equivalent Samplers Performance test Specifications Acceptance criteria § 53.62 Full Wind Tunnel... Results: 95% ≤ Rc ≤ 105%. § 53.63 Wind Tunnel Inlet Aspiration Test Liquid VOAG produced aerosol at 2 km... Class II Equivalent Samplers F Table F-1 to Subpart F of Part 53 Protection of Environment ENVIRONMENTAL...

40 CFR Table F-1 to Subpart F of... - Performance Specifications for PM2.5 Class II Equivalent Samplers

Code of Federal Regulations, 2012 CFR

2012-07-01

... Equivalent Samplers Performance test Specifications Acceptance criteria § 53.62 Full Wind Tunnel Evaluation...% ≤ Rc ≤ 105%. § 53.63 Wind Tunnel Inlet Aspiration Test Liquid VOAG produced aerosol at 2 km/hr and 24... Class II Equivalent Samplers F Table F-1 to Subpart F of Part 53 Protection of Environment ENVIRONMENTAL...

40 CFR Table F-1 to Subpart F of... - Performance Specifications for PM 2.5 Class II Equivalent Samplers

Code of Federal Regulations, 2014 CFR

2014-07-01

... II Equivalent Samplers Performance test Specifications Acceptance criteria § 53.62 Full Wind Tunnel... Results: 95% ≤Rc ≤105%. § 53.63 Wind Tunnel Inlet Aspiration Test Liquid VOAG produced aerosol at 2 km/hr... Class II Equivalent Samplers F Table F-1 to Subpart F of Part 53 Protection of Environment ENVIRONMENTAL...

Effect of fed-batch vs. continuous mode of operation on microbial fuel cell performance treating biorefinery wastewater

DOE PAGES

Pannell, Tyler C.; Goud, R. Kannaiah; Schell, Daniel J.; ...

2016-05-01

Bioelectrochemical systems have been shown to treat low-value biorefinery streams while recovering energy, however, low current densities and anode conversion efficiencies (ACE) limit their application. A bioanode was developed via enrichment of electroactive biofilm under fed-batch and continuous feeding conditions using corn stover-derived waste stream. The continuously-fed MFC exhibited a current density of 5.8±0.06 A/m 2 and an ACE of 39%±4. The fed-batch MFC achieved a similar current density and an ACE of 19.2%, however, its performance dropped after 36 days of operation to 1.1 A/m 2 and 0.5%, respectively. In comparison, the ACE of the continuously-fed MFC remained stablemore » achieving an ACE of 30% ± 3 after 48 days of operation. An MFC treating a biorefinery stream post fuel separation achieved a current density of 10.7±0.1 A/m 2 and an ACE of 57% ± 9 at an organic loading of 12.5 g COD/L-day. Characterization of the microbial communities indicate higher abundance of Firmicutes and Proteobacteria and lower abundance of Bacteriodetes and a higher level of Geobacter spp. (1.4% vs. 0.2%) in continuously-fed MFC vs. fed-batch MFC. Finally, the results demonstrate that limiting substrate to the equivalent maximum current that the anode can generate, maintains MFC performance over a long term for high strength wastewaters, such as those generated in the biorefinery.« less

Effect of fed-batch vs. continuous mode of operation on microbial fuel cell performance treating biorefinery wastewater

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

Pannell, Tyler C.; Goud, R. Kannaiah; Schell, Daniel J.

Bioelectrochemical systems have been shown to treat low-value biorefinery streams while recovering energy, however, low current densities and anode conversion efficiencies (ACE) limit their application. A bioanode was developed via enrichment of electroactive biofilm under fed-batch and continuous feeding conditions using corn stover-derived waste stream. The continuously-fed MFC exhibited a current density of 5.8±0.06 A/m 2 and an ACE of 39%±4. The fed-batch MFC achieved a similar current density and an ACE of 19.2%, however, its performance dropped after 36 days of operation to 1.1 A/m 2 and 0.5%, respectively. In comparison, the ACE of the continuously-fed MFC remained stablemore » achieving an ACE of 30% ± 3 after 48 days of operation. An MFC treating a biorefinery stream post fuel separation achieved a current density of 10.7±0.1 A/m 2 and an ACE of 57% ± 9 at an organic loading of 12.5 g COD/L-day. Characterization of the microbial communities indicate higher abundance of Firmicutes and Proteobacteria and lower abundance of Bacteriodetes and a higher level of Geobacter spp. (1.4% vs. 0.2%) in continuously-fed MFC vs. fed-batch MFC. Finally, the results demonstrate that limiting substrate to the equivalent maximum current that the anode can generate, maintains MFC performance over a long term for high strength wastewaters, such as those generated in the biorefinery.« less

Role of the Direct Teaching Method in the Academic Achievement of Students in English at the Secondary Level

ERIC Educational Resources Information Center

Hussain, Ishtiaq; Inamullah, Hafiz; Naseer-Ud-Din, Muhammad; Hafizatullah, Hafiz

2009-01-01

The major objective of this study was to determine the role of the direct teaching method in the academic achievement of students in English at the secondary level. To achieve the said objective, the "Solomon Four-Design pre-test/post-test equivalent group design" was considered to be the most useful design for this study. The pre-test…

The Impact of Language Factors on Learner Achievement in Science

ERIC Educational Resources Information Center

Prinsloo, C. H.; Rogers, S. C.; Harvey, J. C.

2018-01-01

South African learner achievement remains poor, despite large investment in schooling over the last two decades. Literature and research findings offer no single explanation or solution. In this article, the authors explored the relative contribution of specific language factors such as the role of home- and school-language equivalence, cultural…

Effect of Computer-Assisted Instruction on Secondary School Students' Achievement in Ecological Concepts

ERIC Educational Resources Information Center

Nkemdilim, Egbunonu Roseline; Okeke, Sam O. C.

2014-01-01

This study investigated the effects of computer-assisted instruction (CAI) on students' achievement in ecological concepts. Quasi-experimental design, specifically the pre-test post test non-equivalent control group design was adopted. The sample consisted of sixty-six (66) senior secondary year two (SS II) biology students, drawn from two…

Effects of Graphic Organiser on Students' Achievement in Algebraic Word Problems

ERIC Educational Resources Information Center

Owolabi, Josiah; Adaramati, Tobiloba Faith

2015-01-01

This study investigated the effects of graphic organiser and gender on students' academic achievement in algebraic word problem. Three research questions and three null hypotheses were used in guiding this study. Quasi experimental research was employed and Non-equivalent pre and post test design was used. The study involved the Senior Secondary…

Student Achievement in the Four-Day School Week.

ERIC Educational Resources Information Center

Daly, Joseph L.; Richburg, Robert W.

To gather longitudinal student achievement data from schools utilizing the four-day week, Iowa Tests of Basic Skills (ITBS) grade equivalent scores were obtained in 1984 from five rural Colorado school districts for four consecutive years--two years prior to and two years following the districts' change to the shortened week. A first analysis…

40 CFR 63.55 - Maximum achievable control technology (MACT) determinations for affected sources subject to case...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Maximum achievable control technology (MACT) determinations for affected sources subject to case-by-case determination of equivalent emission... Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air Act Sections...

40 CFR 63.55 - Maximum achievable control technology (MACT) determinations for affected sources subject to case...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Maximum achievable control technology (MACT) determinations for affected sources subject to case-by-case determination of equivalent emission... Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air Act Sections...

40 CFR 63.55 - Maximum achievable control technology (MACT) determinations for affected sources subject to case...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Maximum achievable control technology (MACT) determinations for affected sources subject to case-by-case determination of equivalent emission... Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air Act Sections...

40 CFR 63.55 - Maximum achievable control technology (MACT) determinations for affected sources subject to case...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Maximum achievable control technology (MACT) determinations for affected sources subject to case-by-case determination of equivalent emission... Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air Act Sections...

75 FR 38864 - Qualification of Drivers; Exemption Renewals; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-06

... safety. The Agency has concluded that granting these exemptions will provide a level of safety that will... likely achieve a level of safety that is equivalent to, or greater than, the level that would be achieved... exemption has resulted in a lower level of safety than was maintained before it was granted; or (3...

Counteracting tobacco motor sports sponsorship as a promotional tool: is the tobacco settlement enough?

PubMed

Siegel, M

2001-07-01

This study sought to quantify television advertising exposure achieved by tobacco companies through sponsorship of motor sports events and to evaluate the likely effect of the Master Settlement Agreement on this advertising. Data from Sponsors Report, which quantifies the exposure that sponsors of selected televised sporting events receive during broadcasts of those events, were compiled for all motor sports events covered by the service for the period 1997 through 1999. From 1997 through 1999, tobacco companies achieved 169 hours of television advertising exposure and $410.5 million of advertising value for their products by sponsoring motor sports events. If tobacco companies comply with the Master Settlement Agreement and maintain their advertising at 1999 levels, they will still be able to achieve more than 25 hours of television exposure and an equivalent television advertising value of $99.1 million per year. Despite a federal ban on tobacco advertising on television, tobacco companies achieve the equivalent of more than $150 million in television advertising per year through their sponsorship of motor sports events. The Master Settlement Agreement likely will do little to address this problem.

Time skewing and amplitude nonlinearity mitigation by feedback equalization for 56 Gbps VCSEL-based PAM-4 links

NASA Astrophysics Data System (ADS)

You, Yue; Zhang, Wenjia; Sun, Lin; Du, Jiangbing; Liang, Chenyu; Yang, Fan; He, Zuyuan

2018-03-01

The vertical cavity surface emitting laser (VCSEL)-based multimode optical transceivers enabled by pulse amplitude modulation (PAM)-4 will be commercialized in near future to meet the 400-Gbps standard short reach optical interconnects. It is still challenging to achieve over 56/112-Gbps with the multilevel signaling as the multimode property of the device and link would introduce the nonlinear temporal response for the different levels. In this work, we scrutinize the distortions that relates to the multilevel feature of PAM-4 modulation, and propose an effective feedback equalization scheme for 56-Gbps VCSEL-based PAM-4 optical interconnects system to mitigate the distortions caused by eye timing-skew and nonlinear power-dependent noise. Level redistribution at Tx side is theoretically modeled and constructed to achieve equivalent symbol error ratios (SERs) of four levels and improved BER performance. The cause of the eye skewing and the mitigation approach are also simulated at 100-Gbps and experimentally investigated at 56-Gbps. The results indicate more than 2-dB power penalty improvement has been achieved by using such a distortion aware equalizer.

Teleparallel equivalent of Lovelock gravity

NASA Astrophysics Data System (ADS)

González, P. A.; Vásquez, Yerko

2015-12-01

There is a growing interest in modified gravity theories based on torsion, as these theories exhibit interesting cosmological implications. In this work inspired by the teleparallel formulation of general relativity, we present its extension to Lovelock gravity known as the most natural extension of general relativity in higher-dimensional space-times. First, we review the teleparallel equivalent of general relativity and Gauss-Bonnet gravity, and then we construct the teleparallel equivalent of Lovelock gravity. In order to achieve this goal, we use the vielbein and the connection without imposing the Weitzenböck connection. Then, we extract the teleparallel formulation of the theory by setting the curvature to null.

Limited knowledge of fraction representations differentiates middle school students with mathematics learning disability (dyscalculia) vs. low mathematics achievement

PubMed Central

Mazzocco, Michèle M. M.; Myers, Gwen F.; Lewis, Katherine E.; Hanich, Laurie B.; Murphy, Melissa M.

2014-01-01

Fractions pose significant challenges for many children, but for some children those challenges persist into high school. Here we administered a fractions magnitude comparison test to 122 children, from Grades 4 to 8, to test whether their knowledge of fractions typically learned early in the sequence of formal math instruction (e.g., fractions equivalent to “one-half,” and fraction pairs with common denominators) differentiates those with mathematical learning disability (MLD) versus low achievement (LA) or typical achievement (TA) in mathematics, and whether long term learning trajectories of this knowledge also differentiate these groups. We confirmed that although 4th graders with LA (n = 18) or TA (n = 93) are more accurate evaluating one-half vs. non-half fractions (until they reach ceiling performance levels on both types of fractions), children with MLD (n=11) do not show a one-half advantage until Grade 7 and do not reach ceiling performance even by Grade 8. Both the MLD and LA groups have early difficulties with fractions, but by Grade 5 the LA group approaches performance levels of the TA group and deviates from the MLD group. All groups showed a visual model advantage over Arabic number representation of fractions, but this advantage was short lived for the TA group (because ceiling level was achieved across formats), slightly more persistent for the LA group, and persisted through Grade 8 for children with MLD. Thus, difficulties with fractions persist through Grade 8 for many students, but the nature and trajectories of those difficulties varies across children with math difficulties (MLD or LA). PMID:23587941

Limited knowledge of fraction representations differentiates middle school students with mathematics learning disability (dyscalculia) versus low mathematics achievement.

PubMed

Mazzocco, Michèle M M; Myers, Gwen F; Lewis, Katherine E; Hanich, Laurie B; Murphy, Melissa M

2013-06-01

Fractions pose significant challenges for many children, but for some children those challenges persist into high school. Here we administered a fractions magnitude comparison test to 122 children, from Grades 4 to 8, to test whether their knowledge of fractions typically learned early in the sequence of formal math instruction (e.g., fractions equivalent to one-half, fraction pairs with common denominators) differentiates those with mathematics learning disability (MLD) versus low achievement (LA) or typical achievement (TA) in mathematics and whether long-term learning trajectories of this knowledge also differentiate these groups. We confirmed that although fourth graders with TA (n=93) were more accurate in evaluating "one-half" fractions than in evaluating "non-half" fractions (until they reached ceiling performance levels on both types of fractions), children with MLD (n=11) did not show a one-half advantage until Grade 7 and did not reach ceiling performance even by Grade 8. Both the MLD and LA groups had early difficulties with fractions, but by Grade 5 the LA group approached performance levels of the TA group and deviated from the MLD group. All groups showed a visual model advantage over Arabic number representation of fractions, but this advantage was short-lived for the TA group (because ceiling level was achieved across formats), whereas it was slightly more persistent for the LA group and persisted through Grade 8 for children with MLD. Thus, difficulties with fractions persist through Grade 8 for many students, but the nature and trajectories of those difficulties vary across children with math difficulties (MLD or LA). Copyright © 2013 Elsevier Inc. All rights reserved.

The AMSR2 Satellite-based Microwave Snow Algorithm (SMSA) to estimate regional to global snow depth and snow water equivalent

NASA Astrophysics Data System (ADS)

Kelly, R. E. J.; Saberi, N.; Li, Q.

2017-12-01

With moderate to high spatial resolution (<1 km) regional to global snow water equivalent (SWE) observation approaches yet to be fully scoped and developed, the long-term satellite passive microwave record remains an important tool for cryosphere-climate diagnostics. A new satellite microwave remote sensing approach is described for estimating snow depth (SD) and snow water equivalent (SWE). The algorithm, called the Satellite-based Microwave Snow Algorithm (SMSA), uses Advanced Microwave Scanning Radiometer - 2 (AMSR2) observations aboard the Global Change Observation Mission - Water mission launched by the Japan Aerospace Exploration Agency in 2012. The approach is unique since it leverages observed brightness temperatures (Tb) with static ancillary data to parameterize a physically-based retrieval without requiring parameter constraints from in situ snow depth observations or historical snow depth climatology. After screening snow from non-snow surface targets (water bodies [including freeze/thaw state], rainfall, high altitude plateau regions [e.g. Tibetan plateau]), moderate and shallow snow depths are estimated by minimizing the difference between Dense Media Radiative Transfer model estimates (Tsang et al., 2000; Picard et al., 2011) and AMSR2 Tb observations to retrieve SWE and SD. Parameterization of the model combines a parsimonious snow grain size and density approach originally developed by Kelly et al. (2003). Evaluation of the SMSA performance is achieved using in situ snow depth data from a variety of standard and experiment data sources. Results presented from winter seasons 2012-13 to 2016-17 illustrate the improved performance of the new approach in comparison with the baseline AMSR2 algorithm estimates and approach the performance of the model assimilation-based approach of GlobSnow. Given the variation in estimation power of SWE by different land surface/climate models and selected satellite-derived passive microwave approaches, SMSA provides SWE estimates that are independent of real or near real-time in situ and model data.

Cold-air performance of a tip turbine designed to drive a lift fan

NASA Technical Reports Server (NTRS)

Haas, J. E.; Kofskey, M. G.; Hotz, G. M.

1978-01-01

Performance was obtained over a range of speeds and pressure ratios for a 0.4 linear scale version of the LF460 lift fan turbine with the rotor radial tip clearance reduced to about 2.5 percent of the rotor blade height. These tests covered a range of speeds from 60 to 140 percent of design equivalent speed and a range of scroll inlet total to diffuser exit static pressure ratios from 2.6 to 4.2. Results are presented in terms of equivalent mass flow, equivalent torque, equivalent specific work, and efficiency.

A highly efficient autothermal microchannel reactor for ammonia decomposition: Analysis of hydrogen production in transient and steady-state regimes

NASA Astrophysics Data System (ADS)

Engelbrecht, Nicolaas; Chiuta, Steven; Bessarabov, Dmitri G.

2018-05-01

The experimental evaluation of an autothermal microchannel reactor for H2 production from NH3 decomposition is described. The reactor design incorporates an autothermal approach, with added NH3 oxidation, for coupled heat supply to the endothermic decomposition reaction. An alternating catalytic plate arrangement is used to accomplish this thermal coupling in a cocurrent flow strategy. Detailed analysis of the transient operating regime associated with reactor start-up and steady-state results is presented. The effects of operating parameters on reactor performance are investigated, specifically, the NH3 decomposition flow rate, NH3 oxidation flow rate, and fuel-oxygen equivalence ratio. Overall, the reactor exhibits rapid response time during start-up; within 60 min, H2 production is approximately 95% of steady-state values. The recommended operating point for steady-state H2 production corresponds to an NH3 decomposition flow rate of 6 NL min-1, NH3 oxidation flow rate of 4 NL min-1, and fuel-oxygen equivalence ratio of 1.4. Under these flows, NH3 conversion of 99.8% and H2 equivalent fuel cell power output of 0.71 kWe is achieved. The reactor shows good heat utilization with a thermal efficiency of 75.9%. An efficient autothermal reactor design is therefore demonstrated, which may be upscaled to a multi-kW H2 production system for commercial implementation.

Performance of hybrid nano-micro reinforced mg metal matrix composites brake calliper: simulation approach

NASA Astrophysics Data System (ADS)

Fatchurrohman, N.; Chia, S. T.

2017-10-01

Most commercial vehicles use brake calliper made of grey cast iron (GCI) which possesses heavy weight. This contributes to the total weight of the vehicle which can lead to higher fuel consumption. Another major problem is GCI calliper tends to deflect during clamping action, known as “bending of bridge”. This will result in extended pedal travel. Magnesium metal matrix composites (Mg-MMC) has a potential application in the automotive industry since it having a lower density, higher strength and very good modulus of elasticity as compared to GCI. This paper proposed initial development of hybrid Mg-MMC brake calliper. This was achieved by analyzing the performance of hybrid nano-micro reinforced Mg-MMC and comparing with the conventional GCI brake calliper. It was performed using simulation in ANSYS, a finite element analysis (FEA) software. The results show that hybrid Mg-MMC has better performance in terms of reduction the weight of the brake calliper, reduction in total deformation/deflection and better ability to withstand equivalent elastic strain.

Performance of an exhaled nitric oxide and carbon dioxide sensor using quantum cascade laser-based integrated cavity output spectroscopy.

PubMed

McCurdy, Matthew R; Bakhirkin, Yury; Wysocki, Gerard; Tittel, Frank K

2007-01-01

Exhaled nitric oxide (NO) is an important biomarker in asthma and other respiratory disorders. The optical performance of a NOCO(2) sensor employing integrated cavity output spectroscopy (ICOS) with a quantum cascade laser operating at 5.22 microm capable of real-time NO and CO(2) measurements in a single breath cycle is reported. A NO noise-equivalent concentration of 0.4 ppb within a 1-sec integration time is achieved. The off-axis ICOS sensor performance is compared to a chemiluminescent NO analyzer and a nondispersive infrared (NDIR) CO(2) absorption capnograph. Differences between the gas analyzers are assessed by the Bland-Altman method to estimate the expected variability between the gas sensors. The off-axis ICOS sensor measurements are in good agreement with the data acquired with the two commercial gas analyzers. This work demonstrates the performance characteristics and merits of mid-infrared spectroscopy for exhaled breath analysis.

A comparative appraisal of two equivalence tests for multiple standardized effects.

PubMed

Shieh, Gwowen

2016-04-01

Equivalence testing is recommended as a better alternative to the traditional difference-based methods for demonstrating the comparability of two or more treatment effects. Although equivalent tests of two groups are widely discussed, the natural extensions for assessing equivalence between several groups have not been well examined. This article provides a detailed and schematic comparison of the ANOVA F and the studentized range tests for evaluating the comparability of several standardized effects. Power and sample size appraisals of the two grossly distinct approaches are conducted in terms of a constraint on the range of the standardized means when the standard deviation of the standardized means is fixed. Although neither method is uniformly more powerful, the studentized range test has a clear advantage in sample size requirements necessary to achieve a given power when the underlying effect configurations are close to the priori minimum difference for determining equivalence. For actual application of equivalence tests and advance planning of equivalence studies, both SAS and R computer codes are available as supplementary files to implement the calculations of critical values, p-values, power levels, and sample sizes. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The Short Form 36 English and Chinese versions were equivalent in a multiethnic Asian population.

PubMed

Tan, Maudrene L S; Wee, Hwee-Lin; Lee, Jeannette; Ma, Stefan; Heng, Derrick; Tai, E-Shyong; Thumboo, Julian

2013-07-01

The primary aim of this article was to evaluate measurement equivalence of the English and Chinese versions of the Short Form 36 version 2 (SF-36v2) and Short Form 6D (SF-6D). In this cross-sectional study, health-related quality of life (HRQoL) was measured from 4,973 ethnic Chinese subjects using the SF-36v2 questionnaire. Measurement equivalence of domain and utility scores for the English- and Chinese-language SF-36v2 and SF-6D were assessed by examining the score differences between the two languages using linear regression models, with and without adjustment for known determinants of HRQoL. Equivalence was achieved if the 90% confidence interval (CI) of the differences in scores, due to language, fell within a predefined equivalence margin. Compared with English-speaking Chinese, Chinese-speaking Chinese were significantly older (47.6 vs. 55.5 years). All SF-36v2 domains were equivalent after adjusting for known HRQoL. SF-6D utility/items had the 90% CI either fully or partially overlap their predefined equivalence margin. The English- and Chinese-language versions of the SF-36v2 and SF-6D demonstrated equivalence. Copyright © 2013 Elsevier Inc. All rights reserved.

Designing Intervention Studies: Selected Populations, Range Restrictions, and Statistical Power

PubMed Central

Miciak, Jeremy; Taylor, W. Pat; Stuebing, Karla K.; Fletcher, Jack M.; Vaughn, Sharon

2016-01-01

An appropriate estimate of statistical power is critical for the design of intervention studies. Although the inclusion of a pretest covariate in the test of the primary outcome can increase statistical power, samples selected on the basis of pretest performance may demonstrate range restriction on the selection measure and other correlated measures. This can result in attenuated pretest-posttest correlations, reducing the variance explained by the pretest covariate. We investigated the implications of two potential range restriction scenarios: direct truncation on a selection measure and indirect range restriction on correlated measures. Empirical and simulated data indicated direct range restriction on the pretest covariate greatly reduced statistical power and necessitated sample size increases of 82%–155% (dependent on selection criteria) to achieve equivalent statistical power to parameters with unrestricted samples. However, measures demonstrating indirect range restriction required much smaller sample size increases (32%–71%) under equivalent scenarios. Additional analyses manipulated the correlations between measures and pretest-posttest correlations to guide planning experiments. Results highlight the need to differentiate between selection measures and potential covariates and to investigate range restriction as a factor impacting statistical power. PMID:28479943

Designing Intervention Studies: Selected Populations, Range Restrictions, and Statistical Power.

PubMed

Miciak, Jeremy; Taylor, W Pat; Stuebing, Karla K; Fletcher, Jack M; Vaughn, Sharon

2016-01-01

An appropriate estimate of statistical power is critical for the design of intervention studies. Although the inclusion of a pretest covariate in the test of the primary outcome can increase statistical power, samples selected on the basis of pretest performance may demonstrate range restriction on the selection measure and other correlated measures. This can result in attenuated pretest-posttest correlations, reducing the variance explained by the pretest covariate. We investigated the implications of two potential range restriction scenarios: direct truncation on a selection measure and indirect range restriction on correlated measures. Empirical and simulated data indicated direct range restriction on the pretest covariate greatly reduced statistical power and necessitated sample size increases of 82%-155% (dependent on selection criteria) to achieve equivalent statistical power to parameters with unrestricted samples. However, measures demonstrating indirect range restriction required much smaller sample size increases (32%-71%) under equivalent scenarios. Additional analyses manipulated the correlations between measures and pretest-posttest correlations to guide planning experiments. Results highlight the need to differentiate between selection measures and potential covariates and to investigate range restriction as a factor impacting statistical power.

Equivalent-circuit models for electret-based vibration energy harvesters

NASA Astrophysics Data System (ADS)

Phu Le, Cuong; Halvorsen, Einar

2017-08-01

This paper presents a complete analysis to build a tool for modelling electret-based vibration energy harvesters. The calculational approach includes all possible effects of fringing fields that may have significant impact on output power. The transducer configuration consists of two sets of metal strip electrodes on a top substrate that faces electret strips deposited on a bottom movable substrate functioning as a proof mass. Charge distribution on each metal strip is expressed by series expansion using Chebyshev polynomials multiplied by a reciprocal square-root form. The Galerkin method is then applied to extract all charge induction coefficients. The approach is validated by finite element calculations. From the analytic tool, a variety of connection schemes for power extraction in slot-effect and cross-wafer configurations can be lumped to a standard equivalent circuit with inclusion of parasitic capacitance. Fast calculation of the coefficients is also obtained by a proposed closed-form solution based on leading terms of the series expansions. The achieved analytical result is an important step for further optimisation of the transducer geometry and maximising harvester performance.

Gas phase oxidation downstream of a catalytic combustor

NASA Technical Reports Server (NTRS)

Tien, J. S.; Anderson, D. N.

1979-01-01

Effect of the length available for gas-phase reactions downstream of the catalytic reactor on the emission of CO and unburned hydrocarbons was investigated. A premixed, prevaporized propane/air feed to a 12/cm/diameter catalytic/reactor test section was used. The catalytic reactor was made of four 2.5 cm long monolithic catalyst elements. Four water cooled gas sampling probes were located at positions between 0 and 22 cm downstream of the catalytic reactor. Measurements of unburned hydrocarbon, CO, and CO2 were made. Tests were performed with an inlet air temperature of 800 K, a reference velocity of 10 m/s, pressures of 3 and 600,000 Pa, and fuel air equivalence ratios of 0.14 to 0.24. For very lean mixtures, hydrocarbon emissions were high and CO continued to be formed downstream of the catalytic reactor. At the highest equivalence ratios tested, hydrocarbon levels were much lower and CO was oxidized to CO2 in the gas phase downstream. To achieve acceptable emissions, a downstream region several times longer than the catalytic reactor could be required.

High quality HfO{sub 2}/p-GaSb(001) metal-oxide-semiconductor capacitors with 0.8 nm equivalent oxide thickness

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

Barth, Michael; Datta, Suman, E-mail: sdatta@engr.psu.edu; Bruce Rayner, G.

2014-12-01

We investigate in-situ cleaning of GaSb surfaces and its effect on the electrical performance of p-type GaSb metal-oxide-semiconductor capacitor (MOSCAP) using a remote hydrogen plasma. Ultrathin HfO{sub 2} films grown by atomic layer deposition were used as a high permittivity gate dielectric. Compared to conventional ex-situ chemical cleaning methods, the in-situ GaSb surface treatment resulted in a drastic improvement in the impedance characteristics of the MOSCAPs, directly evidencing a much lower interface trap density and enhanced Fermi level movement efficiency. We demonstrate that by using a combination of ex-situ and in-situ surface cleaning steps, aggressively scaled HfO{sub 2}/p-GaSb MOSCAP structuresmore » with a low equivalent oxide thickness of 0.8 nm and efficient gate modulation of the surface potential are achieved, allowing to push the Fermi level far away from the valence band edge high up into the band gap of GaSb.« less

Spatial sound field synthesis and upmixing based on the equivalent source method.

PubMed

Bai, Mingsian R; Hsu, Hoshen; Wen, Jheng-Ciang

2014-01-01

Given scarce number of recorded signals, spatial sound field synthesis with an extended sweet spot is a challenging problem in acoustic array signal processing. To address the problem, a synthesis and upmixing approach inspired by the equivalent source method (ESM) is proposed. The synthesis procedure is based on the pressure signals recorded by a microphone array and requires no source model. The array geometry can also be arbitrary. Four upmixing strategies are adopted to enhance the resolution of the reproduced sound field when there are more channels of loudspeakers than the microphones. Multi-channel inverse filtering with regularization is exploited to deal with the ill-posedness in the reconstruction process. The distance between the microphone and loudspeaker arrays is optimized to achieve the best synthesis quality. To validate the proposed system, numerical simulations and subjective listening experiments are performed. The results demonstrated that all upmixing methods improved the quality of reproduced target sound field over the original reproduction. In particular, the underdetermined ESM interpolation method yielded the best spatial sound field synthesis in terms of the reproduction error, timbral quality, and spatial quality.

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

Plautz, Tia E.; Johnson, R. P.; Sadrozinski, H. F.-W.

Purpose: To characterize the modulation transfer function (MTF) of the pre-clinical (phase II) head scanner developed for proton computed tomography (pCT) by the pCT collaboration. To evaluate the spatial resolution achievable by this system. Methods: Our phase II proton CT scanner prototype consists of two silicon telescopes that track individual protons upstream and downstream from a phantom, and a 5-stage scintillation detector that measures a combination of the residual energy and range of the proton. Residual energy is converted to water equivalent path length (WEPL) of the protons in the scanned object. The set of WEPL values and associated pathsmore » of protons passing through the object over a 360° angular scan is processed by an iterative parallelizable reconstruction algorithm that runs on GP-GPU hardware. A custom edge phantom composed of water-equivalent polymer and tissue-equivalent material inserts was constructed. The phantom was first simulated in Geant4 and then built to perform experimental beam tests with 200 MeV protons at the Northwestern Medicine Chicago Proton Center. The oversampling method was used to construct radial and azimuthal edge spread functions and modulation transfer functions. The spatial resolution was defined by the 10% point of the modulation transfer function in units of lp/cm. Results: The spatial resolution of the image was found to be strongly correlated with the radial position of the insert but independent of the relative stopping power of the insert. The spatial resolution varies between roughly 4 and 6 lp/cm in both the the radial and azimuthal directions depending on the radial displacement of the edge. Conclusion: The amount of image degradation due to our detector system is small compared with the effects of multiple Coulomb scattering, pixelation of the image and the reconstruction algorithm. Improvements in reconstruction will be made in order to achieve the theoretical limits of spatial resolution.« less

Ecological Equivalence Assessment Methods: What Trade-Offs between Operationality, Scientific Basis and Comprehensiveness?

PubMed

Bezombes, Lucie; Gaucherand, Stéphanie; Kerbiriou, Christian; Reinert, Marie-Eve; Spiegelberger, Thomas

2017-08-01

In many countries, biodiversity compensation is required to counterbalance negative impacts of development projects on biodiversity by carrying out ecological measures, called offset when the goal is to reach "no net loss" of biodiversity. One main issue is to ensure that offset gains are equivalent to impact-related losses. Ecological equivalence is assessed with ecological equivalence assessment methods taking into account a range of key considerations that we summarized as ecological, spatial, temporal, and uncertainty. When equivalence assessment methods take into account all considerations, we call them "comprehensive". Equivalence assessment methods should also aim to be science-based and operational, which is challenging. Many equivalence assessment methods have been developed worldwide but none is fully satisfying. In the present study, we examine 13 equivalence assessment methods in order to identify (i) their general structure and (ii) the synergies and trade-offs between equivalence assessment methods characteristics related to operationality, scientific-basis and comprehensiveness (called "challenges" in his paper). We evaluate each equivalence assessment methods on the basis of 12 criteria describing the level of achievement of each challenge. We observe that all equivalence assessment methods share a general structure, with possible improvements in the choice of target biodiversity, the indicators used, the integration of landscape context and the multipliers reflecting time lags and uncertainties. We show that no equivalence assessment methods combines all challenges perfectly. There are trade-offs between and within the challenges: operationality tends to be favored while scientific basis are integrated heterogeneously in equivalence assessment methods development. One way of improving the challenges combination would be the use of offset dedicated data-bases providing scientific feedbacks on previous offset measures.

Robust high-precision attitude control for flexible spacecraft with improved mixed H2/H∞ control strategy under poles assignment constraint

NASA Astrophysics Data System (ADS)

Liu, Chuang; Ye, Dong; Shi, Keke; Sun, Zhaowei

2017-07-01

A novel improved mixed H2/H∞ control technique combined with poles assignment theory is presented to achieve attitude stabilization and vibration suppression simultaneously for flexible spacecraft in this paper. The flexible spacecraft dynamics system is described and transformed into corresponding state space form. Based on linear matrix inequalities (LMIs) scheme and poles assignment theory, the improved mixed H2/H∞ controller does not restrict the equivalence of the two Lyapunov variables involved in H2 and H∞ performance, which can reduce conservatives compared with traditional mixed H2/H∞ controller. Moreover, it can eliminate the coupling of Lyapunov matrix variables and system matrices by introducing slack variable that provides additional degree of freedom. Several simulations are performed to demonstrate the effectiveness and feasibility of the proposed method in this paper.

Equivalence-Equivalence: Matching Stimuli with Same Discriminative Functions

ERIC Educational Resources Information Center

Carpentier, Franck; Smeets, Paul M.; Barnes-Holmes, Dermot

2004-01-01

Previous studies have shown that after being trained on A-B and A-C match-to-sample tasks, adults match not only same-class B and C stimuli (equivalence) but also BC compounds with same-class elements and with different-class elements (BC-BC). The assumption was that the BC-BC performances are based on matching equivalence and nonequivalence…

Effects of Cloze Instructional Approach on Senior Secondary School Students' Achievement in Igbo Language Reading Comprehension

ERIC Educational Resources Information Center

Eze, Nneka Justina

2015-01-01

This study assessed the effects of cloze instructional approach on senior secondary school students' achievement in Igbo language reading comprehension. The study utilized a quasi experimental research design of the pretest posttest non-equivalent control group design. The study was conducted in Abakaliki education zone of Ebonyi State of Nigeria.…

Effects of Concept Mapping Instruction Approach on Students' Achievement in Basic Science

ERIC Educational Resources Information Center

Ogonnaya, Ukpai Patricia; Okafor, Gabriel; Abonyi, Okechukwu S.; Ugama, J. O.

2016-01-01

The study investigated the effects of concept mapping on students' achievement in basic science. The study was carried out in Ebonyi State of Nigeria. The study employed a quasi-experimental design. Specifically the pretest posttest non-equivalent control group research design was used. The sample was 122 students selected from two secondary…

Effects of Mastery Learning Approach on Secondary School Students' Physics Achievement

ERIC Educational Resources Information Center

Wambugu, Patriciah W.; Changeiywo, Johnson M.

2008-01-01

This study aimed at finding out the effects of Mastery Learning Approach (MLA) on students' achievement in Physics. The study was Quasi-experimental and Solomon Four Non-equivalent Control Group Design was used. The target population comprised of secondary school students in Kieni East Division of Nyeri District. The accessible population was Form…

The Effects of a Mobile Gamification App on Elementary Students' Spanish Achievement and Self-Efficacy

ERIC Educational Resources Information Center

Rachels, Jason R.; Rockinson-Szapkiw, Amanda J.

2018-01-01

A quasi-experimental, pretest-posttest, non-equivalent control group design was used to examine the effect of a mobile gamification application on third and fourth grade students' Spanish language achievement and student academic self-efficacy. In this study, the treatment group's Spanish language instruction was through the use of…

Effect of Problem-Based Learning on Senior Secondary School Students' Achievements in Further Mathematics

ERIC Educational Resources Information Center

Fatade, Alfred Olufemi; Mogari, David; Arigbabu, Abayomi Adelaja

2013-01-01

The study investigated the effect of Problem-based learning (PBL) on senior secondary school students' achievements in Further Mathematics (FM) in Nigeria within the blueprint of pretest-post-test non-equivalent control group quasi-experimental design. Intact classes were used and in all, 96 students participated in the study (42 in the…

Effects of Formative Assessment on Prospective Teachers' Achievement, Attitudes and Self-Regulation Skills

ERIC Educational Resources Information Center

Kincal, Remzi Y.; Ozan, Ceyhun

2018-01-01

The aim of the study is to investigate the effects of formative assessment on prospective teachers' academic achievement, attitudes towards educational measurement and self-regulation skills. In the study, quasi-experimental design including non-equivalent pre-test and post-test control group. There are 40 prospective teachers in each one of the…

Factors Contributing to Mathematics Achievement Differences of Turkish and Australian Students in TIMSS 2007 and 2011

ERIC Educational Resources Information Center

Arikan, Serkan; van de Vijver, Fons J. R.; Yagmur, Kutlay

2016-01-01

Large-scale studies, such as the Trends in International Mathematics and Science Study (TIMSS), provide data to understand cross-national differences and similarities. In this study, we aimed to identify factors predicting mathematics achievement of Turkish students by comparing to Australian students. First, construct equivalence and item bias…

Pressure polymerization of polyester

DOEpatents

Maurer, Charles J.; Shaw, Gordon; Smith, Vicky S.; Buelow, Steven J.; Tumas, William; Contreras, Veronica; Martinez, Ronald J.

2000-08-29

A process is disclosed for the preparation of a polyester polymer or polyester copolymer under superatmospheric pressure conditions in a pipe or tubular reaction under turbannular flow conditions. Reaction material having a glycol equivalents to carboxylic acid equivalents mole ratio of from 1.0:1 to 1.2:1, together with a superatmospheric dense gaseous medium are fed co-currently to the reactor. Dicarboxylic acid and/or diol raw materials may be injected into any of the reaction zones in the process during operation to achieve the overall desired mole ratio balance. The process operates at temperatures of from about 220.degree. C. to about 320.degree. C., with turbannular flow achieved before the polymer product and gas exit the reactor process. The pressure in the reaction zones can be in the range from 15 psia to 2500 psia. A polymer product having a DP of a greater than 40, more preferably at least about 70, is achieved by the transfer of water from the reacting material polymer melt to the gaseous medium in the reactor.

Comparing primary energy attributed to renewable energy with primary energy equivalent to determine carbon abatement in a national context.

PubMed

Gallachóir, Brian P O; O'Leary, Fergal; Bazilian, Morgan; Howley, Martin; McKeogh, Eamon J

2006-01-01

The current conventional approach to determining the primary energy associated with non-combustible renewable energy (RE) sources such as wind energy and hydro power is to equate the electricity generated from these sources with the primary energy supply. This paper compares this with an approach that was formerly used by the IEA, in which the primary energy equivalent attributed to renewable energy was equated with the fossil fuel energy it displaces. Difficulties with implementing this approach in a meaningful way for international comparisons lead to most international organisations abandoning the primary energy equivalent methodology. It has recently re-emerged in prominence however, as efforts grow to develop baseline procedures for quantifying the greenhouse gas (GHG) emissions avoided by renewable energy within the context of the Kyoto Protocol credit trading mechanisms. This paper discusses the primary energy equivalent approach and in particular the distinctions between displacing fossil fuel energy in existing plant or in new plant. The approach is then extended provide insight into future primary energy displacement by renewable energy and to quantify the amount of CO2 emissions avoided by renewable energy. The usefulness of this approach in quantifying the benefits of renewable energy is also discussed in an energy policy context, with regard to increasing security of energy supply as well as reducing energy-related GHG (and other) emissions. The approach is applied in a national context and Ireland is case study country selected for this research. The choice of Ireland is interesting in two respects. The first relates to the high proportion of electricity only fossil fuel plants in Ireland resulting in a significant variation between primary energy and primary energy equivalent. The second concerns Ireland's poor performance to date in limiting GHG emissions in line with its Kyoto target and points to the need for techniques to quantify the potential contribution of renewable energy in achieving the target set.

Conceptual Versus Algorithmic Problem-solving: Focusing on Problems Dealing with Conservation of Matter in Chemistry

NASA Astrophysics Data System (ADS)

Salta, Katerina; Tzougraki, Chryssa

2011-08-01

The students' performance in various types of problems dealing with the conservation of matter during chemical reactions has been investigated at different levels of schooling. The participants were 499 ninth grade (ages 14, 15 years) and 624 eleventh grade (ages 16, 17 years) Greek students. Data was collected using a written questionnaire concerning basic chemical concepts. Results of statistical factor and correlation analysis confirmed the classification of the problems used in three types: "algorithmic-type", "particulate-type", and "conceptual-type". All the students had a far better performance in "particulate-type" problems than in the others. Although students' ability in solving "algorithmic-type" problem increases as their school experience in chemistry progresses, their ability in solving "conceptual-type" problems decreases. Students' achievement in chemistry was measured by a Chemical Concepts Test (CCT) containing 57 questions of various forms. High-achievement students scored higher both on "algorithmic-type" and "particulate-type" problems than low achievers with the greatest difference observed in solving "algorithmic-type" problems. It is concluded that competence in "particulate-type" and "algorithmic-type" problem solving may be independent of competence in solving "conceptual-type" ones. Furthermore, it was found that students' misconceptions concerning chemical reactions and equivalence between mass and energy are impediments to their problem solving abilities. Finally, based on the findings, few suggestions concerning teaching practices are discussed.

Towards Implementation of a Generalized Architecture for High-Level Quantum Programming Language

NASA Astrophysics Data System (ADS)

Ameen, El-Mahdy M.; Ali, Hesham A.; Salem, Mofreh M.; Badawy, Mahmoud

2017-08-01

This paper investigates a novel architecture to the problem of quantum computer programming. A generalized architecture for a high-level quantum programming language has been proposed. Therefore, the programming evolution from the complicated quantum-based programming to the high-level quantum independent programming will be achieved. The proposed architecture receives the high-level source code and, automatically transforms it into the equivalent quantum representation. This architecture involves two layers which are the programmer layer and the compilation layer. These layers have been implemented in the state of the art of three main stages; pre-classification, classification, and post-classification stages respectively. The basic building block of each stage has been divided into subsequent phases. Each phase has been implemented to perform the required transformations from one representation to another. A verification process was exposed using a case study to investigate the ability of the compiler to perform all transformation processes. Experimental results showed that the efficacy of the proposed compiler achieves a correspondence correlation coefficient about R ≈ 1 between outputs and the targets. Also, an obvious achievement has been utilized with respect to the consumed time in the optimization process compared to other techniques. In the online optimization process, the consumed time has increased exponentially against the amount of accuracy needed. However, in the proposed offline optimization process has increased gradually.

Goal equivalent manifold analysis of task performance in non-specific LBP and healthy subjects during repetitive trunk movement: Effect of load, velocity, symmetry.

PubMed

Chehrehrazi, Mahshid; Sanjari, Mohammad Ali; Mokhtarinia, Hamid Reza; Jamshidi, Ali Ashraf; Maroufi, Nader; Parnianpour, Mohamad

2017-01-01

Motor abundance allows reliability of motor performance despite its variability. The nature of this variability provides important information on the flexibility of control strategies. This feature of control may be affected by low back pain (LPB) and trunk flexion/extension conditions. Goal equivalent manifold (GEM) analysis was used to quantify the ability to exploit motor abundance during repeated trunk flexion/extension in healthy individuals and people with chronic non-specific LBP (CNSLBP). Kinematic data were collected from 22 healthy volunteers and 22 CNSLBP patients during metronomically timed, repeated trunk flexion/extension in three conditions of symmetry, velocity, and loading; each at two levels. A goal function for the task was defined as maintaining a constant movement time at each cycle. Given the GEM, flexibility index and performance index were calculated respectively as amounts of goal-equivalent variability and the ratio of goal-equivalent to non-goal-equivalent variability. CNSLBP group was as similar as healthy individuals in both flexibility index (p=0.41) and performance index (p=0.24). Performance index was higher in asymmetric (p<0.001), high velocity (p<0.001), and loaded (p=0.006) conditions. Performance and flexibility in using motor abundance were influenced by repeated trunk flexion/extension conditions. However, these measures were not significantly affected by CNSLBP. Copyright © 2016 Elsevier B.V. All rights reserved.

Engineering a synthetic anaerobic respiration for reduction of xylose to xylitol using NADH output of glucose catabolism by Escherichia coli AI21.

PubMed

Iverson, Andrew; Garza, Erin; Manow, Ryan; Wang, Jinhua; Gao, Yuanyuan; Grayburn, Scott; Zhou, Shengde

2016-04-16

Anaerobic rather than aerobic fermentation is preferred for conversion of biomass derived sugars to high value redox-neutral and reduced commodities. This will likely result in a higher yield of substrate to product conversion and decrease production cost since substrate often accounts for a significant portion of the overall cost. To this goal, metabolic pathway engineering has been used to optimize substrate carbon flow to target products. This approach works well for the production of redox neutral products such as lactic acid from redox neutral sugars using the reducing power NADH (nicotinamide adenine dinucleotide, reduced) generated from glycolysis (2 NADH per glucose equivalent). Nevertheless, greater than two NADH per glucose catabolized is needed for the production of reduced products (such as xylitol) from redox neutral sugars by anaerobic fermentation. The Escherichia coli strain AI05 (ΔfrdBC ΔldhA ΔackA Δ(focA-pflB) ΔadhE ΔptsG ΔpdhR::pflBp 6-(aceEF-lpd)), previously engineered for reduction of xylose to xylitol using reducing power (NADH equivalent) of glucose catabolism, was further engineered by 1) deleting xylAB operon (encoding for xylose isomerase and xylulokinase) to prevent xylose from entering the pentose phosphate pathway; 2) anaerobically expressing the sdhCDAB-sucABCD operon (encoding for succinate dehydrogenase, α-ketoglutarate dehydrogenase and succinyl-CoA synthetase) to enable an anaerobically functional tricarboxcylic acid cycle with a theoretical 10 NAD(P)H equivalent per glucose catabolized. These reducing equivalents can be oxidized by synthetic respiration via xylose reduction, producing xylitol. The resulting strain, AI21 (pAI02), achieved a 96 % xylose to xylitol conversion, with a yield of 6 xylitol per glucose catabolized (molar yield of xylitol per glucose consumed (YRPG) = 6). This represents a 33 % improvement in xylose to xylitol conversion, and a 63 % increase in xylitol yield per glucose catabolized over that achieved by AI05 (pAI02). Increasing reducing power (NADH equivalent) output per glucose catabolized was achieved by anaerobic expression of both the pdh operon (pyruvate dehydrogenase) and the sdhCDAB-sucABCD operon, resulting in a strain capable of generating 10 NADH equivalent per glucose under anaerobic condition. The new E. coli strain AI21 (pAI02) achieved an actual 96 % conversion of xylose to xylitol (via synthetic respiration), and 6 xylitol (from xylose) per glucose catabolized (YRPG = 6, the highest known value). This strategy can be used to engineer microbial strains for the production of other reduced products from redox neutral sugars using glucose as a source of reducing power.

MEASUREMENT EQUIVALENCE OF NEIGHBORHOOD QUALITY MEASURES FOR EUROPEAN AMERICAN AND MEXICAN AMERICAN FAMILIES

PubMed Central

Kim, Su Yeong; Nair, Rajni; Knight, George P.; Roosa, Mark W.; Updegraff, Kimberly A.

2009-01-01

The factorial and construct equivalence of subscales assessing parents’ and children’s perceptions of the quality of their neighborhood was examined in Mexican American and European American families. All subscales (dangerous people in the neighborhood, sense of safety in the neighborhood, quality of the physical environment) demonstrated adequate partial factorial invariance across English- and Spanish-speaking Mexican American and European American families. Reports by children about dangerous people in the neighborhood was the closest to achieving strict factorial invariance, and the only one of the four dimensions to achieve invariance in the validity analyses across Mexican American and European American families. The implications of using these self-report neighborhood quality measures in studies of multiple cultural or language groups are discussed. PMID:19183709

Performance of Axial-Flow Supersonic Compressor on XJ-55-FF-1 Turbojet Engine. I - Preliminary Performance of Compressor. 1; Preliminary Performance of Compressor

NASA Technical Reports Server (NTRS)

Hartmann, Melvin J.; Graham, Robert C.

1949-01-01

An investigation was conducted to determine the performance characteristics of the axial-flow supersonic compressor of the XJ-55-FF-1 turbo Jet engine. The test unit consisted of a row of inlet guide vanes and a supersonic rotor; the stator vanes after the rotor were omitted. The maximum pressure ratio produced in the single stage was 2.28 at an equivalent tip speed or 1814 feet per second with an adiabatic efficiency of approximately 0.61, equivalent weight flow of 13.4 pounds per second. The maximum efficiency of 0.79 was obtained at an equivalent tip speed of 801 feet per second.

Breast Milk Feeding, Brain Development, and Neurocognitive Outcomes: A 7-Year Longitudinal Study in Infants Born at Less Than 30 Weeks' Gestation.

PubMed

Belfort, Mandy B; Anderson, Peter J; Nowak, Victoria A; Lee, Katherine J; Molesworth, Charlotte; Thompson, Deanne K; Doyle, Lex W; Inder, Terrie E

2016-10-01

To determine the associations of breast milk intake after birth with neurological outcomes at term equivalent and 7 years of age in very preterm infants We studied 180 infants born at <30 weeks' gestation or <1250 grams birth weight enrolled in the Victorian Infant Brain Studies cohort from 2001-2003. We calculated the number of days on which infants received >50% of enteral intake as breast milk from 0-28 days of life. Outcomes included brain volumes measured by magnetic resonance imaging at term equivalent and 7 years of age, and cognitive (IQ, reading, mathematics, attention, working memory, language, visual perception) and motor testing at 7 years of age. We adjusted for age, sex, social risk, and neonatal illness in linear regression. A greater number of days on which infants received >50% breast milk was associated with greater deep nuclear gray matter volume at term equivalent age (0.15 cc/d; 95% CI, 0.05-0.25); and with better performance at age 7 years of age on IQ (0.5 points/d; 95% CI, 0.2-0.8), mathematics (0.5; 95% CI, 0.1-0.9), working memory (0.5; 95% CI, 0.1-0.9), and motor function (0.1; 95% CI, 0.0-0.2) tests. No differences in regional brain volumes at 7 years of age in relation to breast milk intake were observed. Predominant breast milk feeding in the first 28 days of life was associated with a greater deep nuclear gray matter volume at term equivalent age and better IQ, academic achievement, working memory, and motor function at 7 years of age in very preterm infants. Copyright © 2016 Elsevier Inc. All rights reserved.

Main factors in E-Learning for the Equivalency Education Program (E-LEEP)

NASA Astrophysics Data System (ADS)

Yel, M. B.; Sfenrianto

2018-03-01

There is a tremendous learning gap between formal education and non-formal education. E-Learning can facilitate non-formal education learners in improving the learning process. In this study, we present the main factors behind the E-learning for the Equivalency Education Program (E-LEEP) initiative in Indonesia. There are four main factors proposed, namely: standardization, learning materials, learning process, and learners’ characteristics. Each factor supports each other to achieve the learning process of E-LEEP in Indonesia. Although not yet proven, the E-learning should be developed followed the main factors for the non-formal education. This is because those factors can improve the quality of E-Learning for the Equivalency Education Program.

A Community Standard: Equivalency of Healthcare in Australian Immigration Detention.

PubMed

Essex, Ryan

2017-08-01

The Australian government has long maintained that the standard of healthcare provided in its immigration detention centres is broadly comparable with health services available within the Australian community. Drawing on the literature from prison healthcare, this article examines (1) whether the principle of equivalency is being applied in Australian immigration detention and (2) whether this standard of care is achievable given Australia's current policies. This article argues that the principle of equivalency is not being applied and that this standard of health and healthcare will remain unachievable in Australian immigration detention without significant reform. Alternate approaches to addressing the well documented issues related to health and healthcare in Australian immigration detention are discussed.

Design and Analysis of a Flexible, Reliable Deep Space Life Support System

NASA Technical Reports Server (NTRS)

Jones, Harry W.

2012-01-01

This report describes a flexible, reliable, deep space life support system design approach that uses either storage or recycling or both together. The design goal is to provide the needed life support performance with the required ultra reliability for the minimum Equivalent System Mass (ESM). Recycling life support systems used with multiple redundancy can have sufficient reliability for deep space missions but they usually do not save mass compared to mixed storage and recycling systems. The best deep space life support system design uses water recycling with sufficient water storage to prevent loss of crew if recycling fails. Since the amount of water needed for crew survival is a small part of the total water requirement, the required amount of stored water is significantly less than the total to be consumed. Water recycling with water, oxygen, and carbon dioxide removal material storage can achieve the high reliability of full storage systems with only half the mass of full storage and with less mass than the highly redundant recycling systems needed to achieve acceptable reliability. Improved recycling systems with lower mass and higher reliability could perform better than systems using storage.

Effect of end-wall riblets on radial turbine performance

NASA Astrophysics Data System (ADS)

Khader, M. A.; Sayma, A. I.

2017-08-01

This paper presents a detailed study of the impact of manufacturing residual riblets at the rotor hub surface of a radial inflow turbine on the flow within the rotor passages and their contribution to drag reduction. Numerical analysis has been used to study the effects of those features at design point conditions. Riblets with different height and spacing have been examined to determine the riblet geometry where the maximum drag reduction is achieved. The relative height of the riblets to rotor inlet blade height was introduced to generalise the results. At the end of this study the results were compared with the available data in literature. It was found that the introduction of riblets could reduce the wall shear stress at the hub surface, while they contribute to increasing the streamwise vorticity within the rotor passage. For the geometries tested, the minimum drag was achieved using riblets with relative height hrel = 2.5% equivalent to 19.3 wall units. The results revealed that the spacing between riblets have a minor effect on their performance, this is due to the size of the streamwise vortex above the hub surface which will be discussed in this work.

Code Parallelization with CAPO: A User Manual

NASA Technical Reports Server (NTRS)

Jin, Hao-Qiang; Frumkin, Michael; Yan, Jerry; Biegel, Bryan (Technical Monitor)

2001-01-01

A software tool has been developed to assist the parallelization of scientific codes. This tool, CAPO, extends an existing parallelization toolkit, CAPTools developed at the University of Greenwich, to generate OpenMP parallel codes for shared memory architectures. This is an interactive toolkit to transform a serial Fortran application code to an equivalent parallel version of the software - in a small fraction of the time normally required for a manual parallelization. We first discuss the way in which loop types are categorized and how efficient OpenMP directives can be defined and inserted into the existing code using the in-depth interprocedural analysis. The use of the toolkit on a number of application codes ranging from benchmark to real-world application codes is presented. This will demonstrate the great potential of using the toolkit to quickly parallelize serial programs as well as the good performance achievable on a large number of toolkit to quickly parallelize serial programs as well as the good performance achievable on a large number of processors. The second part of the document gives references to the parameters and the graphic user interface implemented in the toolkit. Finally a set of tutorials is included for hands-on experiences with this toolkit.

40 CFR 60.47Da - Commercial demonstration permit.

Code of Federal Regulations, 2010 CFR

2010-07-01

... may not exceed the following equivalent MW electrical generation capacity for any one technology... plants may not exceed 15,000 MW. Technology Pollutant Equivalent electrical capacity(MW electrical output... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Electric Utility...

40 CFR 60.47Da - Commercial demonstration permit.

Code of Federal Regulations, 2011 CFR

2011-07-01

... may not exceed the following equivalent MW electrical generation capacity for any one technology... plants may not exceed 15,000 MW. Technology Pollutant Equivalent electrical capacity(MW electrical output... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Electric Utility...

Study of adaptive methods for data compression of scanner data

NASA Technical Reports Server (NTRS)

1977-01-01

The performance of adaptive image compression techniques and the applicability of a variety of techniques to the various steps in the data dissemination process are examined in depth. It is concluded that the bandwidth of imagery generated by scanners can be reduced without introducing significant degradation such that the data can be transmitted over an S-band channel. This corresponds to a compression ratio equivalent to 1.84 bits per pixel. It is also shown that this can be achieved using at least two fairly simple techniques with weight-power requirements well within the constraints of the LANDSAT-D satellite. These are the adaptive 2D DPCM and adaptive hybrid techniques.

Flexible thin broadband microwave absorber based on a pyramidal periodic structure of lossy composite.

PubMed

Huang, Yixing; Yuan, Xujin; Wang, Changxian; Chen, Mingji; Tang, Liqun; Fang, Daining

2018-06-15

Microwave absorber with broadband absorption and thin thickness is one of the main research interests in this field. A flexible ultrathin and broadband microwave absorber comprising multiwall carbon nanotubes, spherical carbonyl iron, and silicone rubber is fabricated in a newly proposed pyramidal spatial periodic structure (SPS). The SPS with equivalent thickness of 3.73 mm covers the -10  dB and -15  dB absorption bandwidth in the frequency range 2-40 GHz and 10-40 GHz, respectively. The excellent absorption performance is achieved by concentration and dissipation of the electromagnetic field inside different parts of the magnetic-dielectric lossy protrusions in different frequency ranges.

Attenuation of FJ44 Turbofan Engine Noise with a Foam-Metal Liner Installed Over-the-Rotor

NASA Technical Reports Server (NTRS)

Sutliff, Daniel L.; Elliott, Dave M.; Jones, Michael G.; Hartley, Thomas C.

2009-01-01

A Williams International FJ44-3A 3000-lb thrust class turbofan engine was used as a demonstrator for a Foam-Metal Liner (FML) installed in close proximity to the fan. Two FML designs were tested and compared to the hardwall baseline. Traditional single degree-of-freedom liner designs were also evaluated to provide a comparison. Farfield acoustic levels and limited engine performance results are presented in this paper. The results show that the FML achieved up to 5 dB Acoustic Power Level (PWL) overall attenuation in the forward quadrant, equivalent to the traditional liner design. An earlier report presented the test set-up and conditions.

Technology Development for a Hyperspectral Microwave Atmospheric Sounder (HyMAS)

NASA Technical Reports Server (NTRS)

Blackwell, W.; Galbraith, C.; Hilliard, L.; Racette, P.; Thompson, E.

2014-01-01

The Hyperspectral Microwave Atmospheric Sounder (HyMAS) is being developed at Lincoln Laboratories and accommodated by the Goddard Space Flight Center for a flight opportunity on a NASA research aircraft. The term hyperspectral microwave is used to indicate an all-weather sounding instrument that performs equivalent to hyperspectral infrared sounders in clear air with vertical resolution of approximately 1 km. Deploying the HyMAS equipped scanhead with the existing Conical Scanning Microwave Imaging Radiometer (CoSMIR) shortens the path to a flight demonstration. Hyperspectral microwave is achieved through the use of independent RF antennas that sample the volume of the Earths atmosphere through various levels of frequencies, thereby producing a set of dense, spaced vertical weighting functions.

Direct catalytic asymmetric aldol-Tishchenko reaction.

PubMed

Gnanadesikan, Vijay; Horiuchi, Yoshihiro; Ohshima, Takashi; Shibasaki, Masakatsu

2004-06-30

A direct catalytic asymmetric aldol reaction of propionate equivalent was achieved via the aldol-Tishchenko reaction. Coupling an irreversible Tishchenko reaction to a reversible aldol reaction overcame the retro-aldol reaction problem and thereby afforded the products in high enantio and diastereoselectivity using 10 mol % of the asymmetric catalyst. A variety of ketones and aldehydes, including propyl and butyl ketones, were coupled efficiently, yielding the corresponding aldol-Tishchenko products in up to 96% yield and 95% ee. Diastereoselectivity was generally below the detection limit of 1H NMR (>98:2). Preliminary studies performed to clarify the mechanism revealed that the aldol products were racemic with no diastereoselectivity. On the other hand, the Tishchenko products were obtained in a highly enantiocontrolled manner.

Can electronic medical images replace hard-copy film? Defining and testing the equivalence of diagnostic tests.

PubMed

Obuchowski, N A

2001-10-15

Electronic medical images are an efficient and convenient format in which to display, store and transmit radiographic information. Before electronic images can be used routinely to screen and diagnose patients, however, it must be shown that readers have the same diagnostic performance with this new format as traditional hard-copy film. Currently, there exist no suitable definitions of diagnostic equivalence. In this paper we propose two criteria for diagnostic equivalence. The first criterion ('population equivalence') considers the variability between and within readers, as well as the mean reader performance. This criterion is useful for most applications. The second criterion ('individual equivalence') involves a comparison of the test results for individual patients and is necessary when patients are followed radiographically over time. We present methods for testing both individual and population equivalence. The properties of the proposed methods are assessed in a Monte Carlo simulation study. Data from a mammography screening study is used to illustrate the proposed methods and compare them with results from more conventional methods of assessing equivalence and inter-procedure agreement. Copyright 2001 John Wiley & Sons, Ltd.

Equivalence Testing as a Tool for Fatigue Risk Management in Aviation.

PubMed

Wu, Lora J; Gander, Philippa H; van den Berg, Margo; Signal, T Leigh

2018-04-01

Many civilian aviation regulators favor evidence-based strategies that go beyond hours-of-service approaches for managing fatigue risk. Several countries now allow operations to be flown outside of flight and duty hour limitations, provided airlines demonstrate an alternative method of compliance that yields safety levels "at least equivalent to" the prescriptive regulations. Here we discuss equivalence testing in occupational fatigue risk management. We present suggested ratios/margins of practical equivalence when comparing operations inside and outside of prescriptive regulations for two common aviation safety performance indicators: total in-flight sleep duration and psychomotor vigilance task reaction speed. Suggested levels of practical equivalence, based on expertise coupled with evidence from field and laboratory studies, are ≤ 30 min in-flight sleep and ± 15% of reference response speed. Equivalence testing is illustrated in analyses of a within-subjects field study during an out-and-back long-range trip. During both sectors of their trip, 41 pilots were monitored via actigraphy, sleep diary, and top of descent psychomotor vigilance task. Pilots were assigned to take rest breaks in a standard lie-flat bunk on one sector and in a bunk tapered 9 from hip to foot on the other sector. Total in-flight sleep duration (134 ± 53 vs. 135 ± 55 min) and mean reaction speed at top of descent (3.94 ± 0.58 vs. 3.77 ± 0.58) were equivalent after rest in the full vs. tapered bunk. Equivalence testing is a complimentary statistical approach to difference testing when comparing levels of fatigue and performance in occupational settings and can be applied in transportation policy decision making.Wu LJ, Gander PH, van den Berg M, Signal TL. Equivalence testing as a tool for fatigue risk management in aviation. Aerosp Med Hum Perform. 2018; 89(4):383-388.

High-Performance Solid-State Thermionic Energy Conversion Based on 2D van der Waals Heterostructures: A First-Principles Study.

PubMed

Wang, Xiaoming; Zebarjadi, Mona; Esfarjani, Keivan

2018-06-18

Two-dimensional (2D) van der Waals heterostructures (vdWHs) have shown multiple functionalities with great potential in electronics and photovoltaics. Here, we show their potential for solid-state thermionic energy conversion and demonstrate a designing strategy towards high-performance devices. We propose two promising thermionic devices, namely, the p-type Pt-G-WSe 2 -G-Pt and n-type Sc-WSe 2 -MoSe 2 -WSe 2 -Sc. We characterize the thermionic energy conversion performance of the latter using first-principles GW calculations combined with real space Green's function (GF) formalism. The optimal barrier height and high thermal resistance lead to an excellent performance. The proposed device is found to have a room temperature equivalent figure of merit of 1.2 which increases to 3 above 600 K. A high performance with cooling efficiency over 30% of the Carnot efficiency above 450 K is achieved. Our designing and characterization method can be used to pursue other potential thermionic devices based on vdWHs.

'Equivalence' and the translation and adaptation of health-related quality of life questionnaires.

PubMed

Herdman, M; Fox-Rushby, J; Badia, X

1997-04-01

The increasing use of health-related quality of life (HRQOL) questionnaires in multinational studies has resulted in the translation of many existing measures. Guidelines for translation have been published, and there has been some discussion of how to achieve and assess equivalence between source and target questionnaires. Our reading in this area had led us, however, to the conclusion that different types of equivalence were not clearly defined, and that a theoretical framework for equivalence was lacking. To confirm this we reviewed definitions of equivalence in the HRQOL literature on the use of generic questionnaires in multicultural settings. The literature review revealed: definitions of 19 different types of equivalence; vague or conflicting definitions, particularly in the case of conceptual equivalence; and the use of many redundant terms. We discuss these findings in the light of a framework adapted from cross-cultural psychology for describing three different orientations to cross-cultural research: absolutism, universalism and relativism. We suggest that the HRQOL field has generally adopted an absolutist approach and that this may account for some of the confusion in this area. We conclude by suggesting that there is an urgent need for a standardized terminology within the HRQOL field, by offering a standard definition of conceptual equivalence, and by suggesting that the adoption of a universalist orientation would require substantial changes to guidelines and more empirical work on the conceptualization of HRQOL in different cultures.

10 CFR Appendix B to Part 73 - General Criteria for Security Personnel

Code of Federal Regulations, 2012 CFR

2012-01-01

... or pass an equivalent performance examination designed to measure basic job-related mathematical... equivalent performance examination designed to measure basic mathematical, language, and reasoning skills... administered by a licensed physician. The examination shall be designed to measure the individual's physical...

The Effects of 5E Inquiry Learning Activities on Achievement and Attitude toward Chemistry

ERIC Educational Resources Information Center

Sen, Senol; Oskay, Ozge Ozyalcin

2017-01-01

The purpose of this study was to investigate the effects of 5E inquiry learning activities on students' achievement, attitude toward chemistry. A non-equivalent control group design was used to the quasi-experimental research in this study. A total of 34 (8 males and 26 females) undergraduates in Turkey voluntarily participated in the study. The…

The Effect of Guided-Inquiry Instruction on 6th Grade Turkish Students' Achievement, Science Process Skills, and Attitudes toward Science

ERIC Educational Resources Information Center

Koksal, Ela Ayse; Berberoglu, Giray

2014-01-01

The purpose of this study is to investigate the effectiveness of guided-inquiry approach in science classes over existing science and technology curriculum in developing content-based science achievement, science process skills, and attitude toward science of grade level 6 students in Turkey. Non-equivalent control group quasi-experimental design…

Effects of Reflective Inquiry Instructional Technique on Students' Academic Achievement and Ability Level in Electronic Work Trade in Technical Colleges

ERIC Educational Resources Information Center

Ogbuanya, T. C.; Owodunni, A. S.

2015-01-01

This study was designed to determine the effect of reflective inquiry instructional technique on achievement of students in Technical Colleges. The study adopted a pre-test, post-test, non-equivalent control group, quasi-experimental research design which involved groups of students in their intact class assigned to experimental group and control…

Effects of Mathematical Vocabulary Instruction on Students' Achievement in Mathematics in Secondary Schools of Murang'a County, Kenya

ERIC Educational Resources Information Center

Wanjiru, Benson; O-Connor, Miheso

2015-01-01

This article is based on a study whose main objective was to determine the effects of mathematical vocabulary instruction on students' achievement in Mathematics in Secondary schools in Murang'a County, Kenya. The study was a non-equivalent control group pretest-posttest quasi-experimental design and was conducted in the two purposively selected…

Effects of Information and Communication Technology (ICT) on Students' Academic Achievement and Retention in Chemistry at Secondary Level

ERIC Educational Resources Information Center

Hussain, Ishtiaq; Suleman, Qaiser; ud Din, M. Naseer; Shafique, Farhan

2017-01-01

The current paper investigated the effects of information and communication technology on the students' academic achievement and retention in chemistry. Fifty students of 9th grade were selected randomly from Kohsar Public School and College Latamber Karak. The students were grouped into equivalent groups based on pretest score. In order to…

Effect of Ethnomathematics Teaching Approach on Senior Secondary Students' Achievement and Retention in Locus

ERIC Educational Resources Information Center

Achor, Emmanuel E.; Imoko, Benjamin I.; Uloko, Emmanuel S.

2009-01-01

This study determined the effectiveness of ethnomathematics teaching approach, ETA on students' achievement and retention in Locus. The study was carried out in education zone B of Benue State of Nigeria using a sample size of 253 Senior Secondary 2 (SS 2) students. It was a non equivalent quasi-experimental study which was guided by two research…

Remediation of Gender Inequity in Science in a Developing Country: An Experiment with Cooperative Concept Mapping.

ERIC Educational Resources Information Center

Osisioma, Uzoamaka Irene Ngozi

The consistent reports on gender inequity in science achievement have led to a search for more effective strategies for correcting the imbalance. This study is part of a search which sought to investigate whether or not the cooperative-concept mapping technique improves the science achievement of girls. A non-equivalent control group…

The Relationship between the Rigor of a State's Proficiency Standard and Student Achievement in the State

ERIC Educational Resources Information Center

Stoneberg, Bert D.

2015-01-01

The National Center of Education Statistics conducted a mapping study that equated the percentage proficient or above on each state's NCLB reading and mathematics tests in grades 4 and 8 to the NAEP scale. Each "NAEP equivalent score" was labeled according to NAEP's achievement levels and used to compare state proficiency standards and…

Counteracting tobacco motor sports sponsorship as a promotional tool: is the tobacco settlement enough?

PubMed Central

Siegel, M

2001-01-01

OBJECTIVES: This study sought to quantify television advertising exposure achieved by tobacco companies through sponsorship of motor sports events and to evaluate the likely effect of the Master Settlement Agreement on this advertising. METHODS: Data from Sponsors Report, which quantifies the exposure that sponsors of selected televised sporting events receive during broadcasts of those events, were compiled for all motor sports events covered by the service for the period 1997 through 1999. RESULTS: From 1997 through 1999, tobacco companies achieved 169 hours of television advertising exposure and $410.5 million of advertising value for their products by sponsoring motor sports events. If tobacco companies comply with the Master Settlement Agreement and maintain their advertising at 1999 levels, they will still be able to achieve more than 25 hours of television exposure and an equivalent television advertising value of $99.1 million per year. CONCLUSIONS: Despite a federal ban on tobacco advertising on television, tobacco companies achieve the equivalent of more than $150 million in television advertising per year through their sponsorship of motor sports events. The Master Settlement Agreement likely will do little to address this problem. PMID:11441738

Comparison of Bruce treadmill exercise test protocols: is ramped Bruce equal or superior to standard bruce in producing clinically valid studies for patients presenting for evaluation of cardiac ischemia or arrhythmia with body mass index equal to or greater than 30?

PubMed

Bires, Angela Macci; Lawson, Dori; Wasser, Thomas E; Raber-Baer, Donna

2013-12-01

Clinically valid cardiac evaluation via treadmill stress testing requires patients to achieve specific target heart rates and to successfully complete the cardiac examination. A comparison of the standard Bruce protocol and the ramped Bruce protocol was performed using data collected over a 1-y period from a targeted patient population with a body mass index (BMI) equal to or greater than 30 to determine which treadmill protocol provided more successful examination results. The functional capacity, metabolic equivalent units achieved, pressure rate product, and total time on the treadmill as measured for the obese patients were clinically valid and comparable to normal-weight and overweight patients (P < 0.001). Data gathered from each protocol demonstrated that the usage of the ramped Bruce protocol achieved more consistent results in comparison across all BMI groups in achieving 80%-85% of their age-predicted maximum heart rate. This study did not adequately establish that the ramped Bruce protocol was superior to the standard Bruce protocol for the examination of patients with a BMI equal to or greater than 30.

Analysis of reflection-peak wavelengths of sampled fiber Bragg gratings with large chirp.

PubMed

Zou, Xihua; Pan, Wei; Luo, Bin

2008-09-10

The reflection-peak wavelengths (RPWs) in the spectra of sampled fiber Bragg gratings with large chirp (SFBGs-LC) are theoretically investigated. Such RPWs are divided into two parts, the RPWs of equivalent uniform SFBGs (U-SFBGs) and the wavelength shift caused by the large chirp in the grating period (CGP). We propose a quasi-equivalent transform to deal with the CGP. That is, the CGP is transferred into quasi-equivalent phase shifts to directly derive the Fourier transform of the refractive index modulation. Then, in the case of both the direct and the inverse Talbot effect, the wavelength shift is obtained from the Fourier transform. Finally, the RPWs of SFBGs-LC can be achieved by combining the wavelength shift and the RPWs of equivalent U-SFBGs. Several simulations are shown to numerically confirm these predicted RPWs of SFBGs-LC.

[Cross-cultural adaptation of the Myocardial Infarction Dimensional Assessment Scale (MIDAS) to the Brazilian Portuguese language].

PubMed

Fiorin, Bruno Henrique; Oliveira, Elizabete Regina Araújo de; Moreira, Rita Simone Lopes; Luna Filho, Bráulio

2018-03-01

From the evaluation of the factors that affect quality of life (QOL) it is possible to plan interventions that lead to the improved well-being of patients. The scope of this study was to conduct the cross-cultural adaptation of the Myocardial Infarction Dimensional Assessment Scale (MIDAS) questionnaire to the Portuguese language, seeking the necessary semantic, idiomatic, conceptual and cultural equivalence. The theoretical framework of Guillemin, Bombardier and Beaton was used, fulfilling the following steps: translation, back translation, evaluation of the authors, peer review and pre-testing. After all the tests, the semantic, idiomatic, conceptual and cultural equivalence was achieved. The scale proved to be easy to use and was clinically important. MIDAS was validated in terms of its semantic, idiomatic, conceptual and cultural equivalences. Subsequently, the measurement equivalence will be evaluated to verify the psychometric properties.

Hierarchically structured MnO2 nanowires supported on hollow Ni dendrites for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Sun, Zhipeng; Firdoz, Shaik; Ying-Xuan Yap, Esther; Li, Lan; Lu, Xianmao

2013-05-01

We report a hierarchical Ni@MnO2 structure consisting of MnO2 nanowires supported on hollow Ni dendrites for high-performance supercapacitors. The Ni@MnO2 structure, which was prepared via a facile electrodeposition method, is highly porous and appears like a forest of pine trees grown vertically on a substrate. At a MnO2 mass loading of 0.35 mg cm-2, the Ni@MnO2 electrode demonstrated a specific capacitance of 1125 F g-1 that is close to the theoretical value. In addition, a remarkable high-rate performance (766 F g-1 at a discharge current density of 100 A g-1) was achieved. Electrochemical tests in a two-electrode configuration for the Ni@MnO2 structure with a high MnO2 loading of 3.6 mg cm-2 showed a low equivalent series resistance (ESR) of 1 Ω and a high specific power of 72 kW kg-1. This superior performance can be attributed to the highly porous and hierarchical structure of Ni@MnO2 that favors rapid diffusion of an electrolyte, highly conductive pathway for electron transport, and efficient material utilization.We report a hierarchical Ni@MnO2 structure consisting of MnO2 nanowires supported on hollow Ni dendrites for high-performance supercapacitors. The Ni@MnO2 structure, which was prepared via a facile electrodeposition method, is highly porous and appears like a forest of pine trees grown vertically on a substrate. At a MnO2 mass loading of 0.35 mg cm-2, the Ni@MnO2 electrode demonstrated a specific capacitance of 1125 F g-1 that is close to the theoretical value. In addition, a remarkable high-rate performance (766 F g-1 at a discharge current density of 100 A g-1) was achieved. Electrochemical tests in a two-electrode configuration for the Ni@MnO2 structure with a high MnO2 loading of 3.6 mg cm-2 showed a low equivalent series resistance (ESR) of 1 Ω and a high specific power of 72 kW kg-1. This superior performance can be attributed to the highly porous and hierarchical structure of Ni@MnO2 that favors rapid diffusion of an electrolyte, highly conductive pathway for electron transport, and efficient material utilization. Electronic supplementary information (ESI) available: More TEM and SEM images, digital photo, XPS, and XRD of the samples. See DOI: 10.1039/c3nr00209h

Cross-cultural adaptation of instruments assessing breastfeeding determinants: a multi-step approach

PubMed Central

2014-01-01

Background Cross-cultural adaptation is a necessary process to effectively use existing instruments in other cultural and language settings. The process of cross-culturally adapting, including translation, of existing instruments is considered a critical set to establishing a meaningful instrument for use in another setting. Using a multi-step approach is considered best practice in achieving cultural and semantic equivalence of the adapted version. We aimed to ensure the content validity of our instruments in the cultural context of KwaZulu-Natal, South Africa. Methods The Iowa Infant Feeding Attitudes Scale, Breastfeeding Self-Efficacy Scale-Short Form and additional items comprise our consolidated instrument, which was cross-culturally adapted utilizing a multi-step approach during August 2012. Cross-cultural adaptation was achieved through steps to maintain content validity and attain semantic equivalence in the target version. Specifically, Lynn’s recommendation to apply an item-level content validity index score was followed. The revised instrument was translated and back-translated. To ensure semantic equivalence, Brislin’s back-translation approach was utilized followed by the committee review to address any discrepancies that emerged from translation. Results Our consolidated instrument was adapted to be culturally relevant and translated to yield more reliable and valid results for use in our larger research study to measure infant feeding determinants effectively in our target cultural context. Conclusions Undertaking rigorous steps to effectively ensure cross-cultural adaptation increases our confidence that the conclusions we make based on our self-report instrument(s) will be stronger. In this way, our aim to achieve strong cross-cultural adaptation of our consolidated instruments was achieved while also providing a clear framework for other researchers choosing to utilize existing instruments for work in other cultural, geographic and population settings. PMID:25285151

Equivalence of the 3-month and 28-day formulations of triptorelin with regard to achievement and maintenance of medical castration in women with endometriosis.

PubMed

Donnez, Jacques; Dewart, Paul J; Hedon, Bernard; Perino, Antonio; Schindler, Adolf E; Blumberg, Joëlle; Querleu, Denis

2004-02-01

The present study aims at demonstrating the equivalence of the 28-day and 3-month formulations of triptorelin SR (sustained release) in terms of percentage of patients achieving castration levels of estradiol (<==50 pg/mL) 84 days after treatment initiation. A phase II, prospective, randomized, multicenter, open study was conducted in two parallel groups of women with endometriosis. Academic hospitals. Seventy-two women with endometriosis. were treated with a single intramuscular injection of 3-month triptorelin SR, and 74 patients were treated with one intramuscular injection of 28-day triptorelin SR every 28 days for 3 months. As part of two parallel treatment groups, 72 women were given a single intramuscular injection of 3-month triptorelin SR, and 74 women were given one intramuscular injection of 28-day triptorelin SR every 28 days for 3 months. Percentage of patients achieving castration levels of estradiol at the end of the treatment period. Patients participated in the study until resumption of menses. Ninety-seven percent of patients given the 3-month formulation and 94% of those given the 28-day formulation were in a state of medical castration on day 84. The mean time to achieve castration was shorter for the 3-month formulation, and the duration of castration was significantly longer. The FSH and LH parameters were comparable, though not always identical. The pharmacodynamic effects of the Decapeptyl SR 3-month formulation are equivalent to those of the 28-day formulation. The 3-month formulation provides the added advantage of a longer maintenance of medical castration in women who have endometriosis.

Effect of fuel-air-ratio nonuniformity on emissions of nitrogen oxides

NASA Technical Reports Server (NTRS)

Lyons, V. J.

1981-01-01

The inlet fuel-air ratio nonuniformity is studied to deterine how nitrogen oxide (NOx) emissions are affected. An increase in NOx emissions with increased fuel-air ratio nonuniformity for average equivalence ratios less than 0.7 and a decrease in NOx emissions for average equivalence ratios near stoichiometric is predicted. The degree of uniformityy of fuel-air ratio profiles that is necessary to achieve NOx emissions goals for actual engines that use lean, premixed, prevaporized combustion systems is determined.

Design conceptuel d'un avion blended wing body de 200 passagers

NASA Astrophysics Data System (ADS)

Ammar, Sami

The Blended Wing Body is built based on the flying wing concept and performance improvements compared to conventional aircraft. Contrariwise, most studies have focused on large aircraft and it is not sure whether the gains are the same for smaller aircraft. The main of objective is to perform the conceptual design of a BWB of 200 passengers and compare the performance obtained with a conventional aircraft equivalent in terms of payload and range. The design of the Blended Wing Body was carried out under the CEASIOM environment. This platform design suitable for conventional aircraft design has been modified and additional tools have been integrated in order to achieve the aerodynamic analysis, performance and stability of the aircraft fuselage built. A plane model is obtained in the geometric module AcBuilder CEASIOM from the design variables of a wing. Estimates of mass are made from semi- empirical formulas adapted to the geometry of the BWB and calculations centering and inertia are possible through BWB model developed in CATIA. Low fidelity methods, such as TORNADO and semi- empirical formulas are used to analyze the aerodynamic performance and stability of the aircraft. The aerodynamic results are validated using a high-fidelity analysis using FLUENT CFD software. An optimization process is implemented in order to obtain improved while maintaining a feasible design performance. It is an optimization of the plan form of the aircraft fuselage integrated with a number of passengers and equivalent to that of a A320.Les performance wing aircraft merged optimized maximum range are compared to A320 also optimized. Significant gains were observed. An analysis of the dynamics of longitudinal and lateral flight is carried out on the aircraft optimized BWB finesse and mass. This study identified the stable and unstable modes of the aircraft. Thus, this analysis has highlighted the stability problems associated with the oscillation of incidence and the Dutch roll for the absence of stabilizers.

A MULTI-ELEMENT THICK GAS ELECTRON MULTIPLIER-BASED MICRODOSEMETER FOR MEASUREMENT OF NEUTRONS DOSE-EQUIVALENT: A MONTE CARLO STUDY.

PubMed

Moslehi, A; Raisali, G

2017-11-01

To determine the dose-equivalent of neutrons in an extended energy range, in the present work a multi-element thick gas electron multiplier-based microdosemeter made of PMMA (Perspex) walls of 10 mm in thickness is designed. Each cavity is filled with the propane-based tissue-equivalent (TE) gas simulating 1 µm of tissue. Also, a few weight fractions of 3He are assumed to be added to the TE gas. The dose-equivalents are determined for 11 neutron energies between thermal and 14 MeV using the lineal energy distributions calculated by Geant4 simulation toolkit and also the lineal energy-based quality factors. The results show that by adding 0.04% of 3He to the TE gas in each cavity, an energy-independent dose-equivalent response within 30% uncertainty around a median value of 0.91 in the above energy range is achieved. It is concluded that after its construction, the studied microdosemeter can be used to measure the dose-equivalent of neutrons, favorably. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Control topologies for deep space formation flying spacecraft

NASA Technical Reports Server (NTRS)

Hadaegh, F. Y.; Smith, R. S.

2002-01-01

This paper gives a characterization of the equivalent topologies and uses this approach to show that there exists a control topology which achieves a global tracking objective using only local controllers.

Design Approach and Implementation of Application Specific Instruction Set Processor for SHA-3 BLAKE Algorithm

NASA Astrophysics Data System (ADS)

Zhang, Yuli; Han, Jun; Weng, Xinqian; He, Zhongzhu; Zeng, Xiaoyang

This paper presents an Application Specific Instruction-set Processor (ASIP) for the SHA-3 BLAKE algorithm family by instruction set extensions (ISE) from an RISC (reduced instruction set computer) processor. With a design space exploration for this ASIP to increase the performance and reduce the area cost, we accomplish an efficient hardware and software implementation of BLAKE algorithm. The special instructions and their well-matched hardware function unit improve the calculation of the key section of the algorithm, namely G-functions. Also, relaxing the time constraint of the special function unit can decrease its hardware cost, while keeping the high data throughput of the processor. Evaluation results reveal the ASIP achieves 335Mbps and 176Mbps for BLAKE-256 and BLAKE-512. The extra area cost is only 8.06k equivalent gates. The proposed ASIP outperforms several software approaches on various platforms in cycle per byte. In fact, both high throughput and low hardware cost achieved by this programmable processor are comparable to that of ASIC implementations.

Atom-optics knife-edge: Measuring sub-nanokelvin momentum distributions

NASA Astrophysics Data System (ADS)

Ramos, Ramon; Spierings, David; Steinberg, Aephraim

2017-04-01

Temperatures below 1 nanokelvin have been achieved in the recent years, enabling new classes of experiments which benefit from the resulting long coherence times. This achievement comes hand in hand with the challenge of measuring such low temperatures. By employing the equivalent of a knife-edge measurement for matter-waves, we have been able to characterize ultra-low momentum widths. We measured a momentum width corresponding to an effective temperature of 900 +/- 200 pK, only limited by our cooling performance. We show that this technique compares favourably with more traditional methods, which would require expansion times of 100's of ms or frequency stability of 10's of Hz. Finally, we show that the effective knife-edge, created by a potential barrier, begins to become ''blunt'' due to tunneling for thin barriers, and we obtain quantitative agreement with a theoretical model. This method is a useful tool for atomic interferometry and other areas in ultracold atoms where a robust and precise technique for characterizing the momentum distribution is required.

Effects of Fuel Distribution on Detonation Tube Performance

NASA Technical Reports Server (NTRS)

Perkins, H. Douglas; Sung, Chih-Jen

2003-01-01

A pulse detonation engine uses a series of high frequency intermittent detonation tubes to generate thrust. The process of filling the detonation tube with fuel and air for each cycle may yield non-uniform mixtures. Uniform mixing is commonly assumed when calculating detonation tube thrust performance. In this study, detonation cycles featuring idealized non-uniform Hz/air mixtures were analyzed using a two-dimensional Navier-Stokes computational fluid dynamics code with detailed chemistry. Mixture non-uniformities examined included axial equivalence ratio gradients, transverse equivalence ratio gradients, and partially fueled tubes. Three different average test section equivalence ratios were studied; one stoichiometric, one fuel lean, and one fuel rich. All mixtures were detonable throughout the detonation tube. Various mixtures representing the same average test section equivalence ratio were shown to have specific impulses within 1% of each other, indicating that good fuel/air mixing is not a prerequisite for optimal detonation tube performance under conditions investigated.

Efficient Residue to Binary Conversion Based on a Modified Flexible Moduli Set

NASA Astrophysics Data System (ADS)

Molahosseini, Amir Sabbagh

2011-09-01

The Residue Number System (RNS) is a non-weighted number system which can perform addition (subtraction) and multiplication on residues without carry-propagation; resulting in high-speed hardware implementations of computation systems. The problem of converting residue numbers to equivalent binary weighted form has been attracted a lot of research for many years. Recently, some researchers proposed using flexible moduli sets instead of previous traditional moduli sets to enhance the performance of residue to binary converters. This paper introduces the modified flexible moduli set {22p+k. 22p+1, 2p+1, 2p-1} which is achieved from the flexible set {2p+k, 22p+1, 2p+1, 2p-1} by enhancing modulo 2p+k. Next, new Chinese remainder theorem-1 is used to design simple and efficient residue to binary converter for this modified set with better performance than the converter of the moduli set {2p+k, 22p+1, 2p+1, 2p-1}.

Coevolutionary Free Lunches

NASA Technical Reports Server (NTRS)

Wolpert, David H.; Macready, William G.

2005-01-01

Recent work on the mathematical foundations of optimization has begun to uncover its rich structure. In particular, the "No Free Lunch" (NFL) theorems state that any two algorithms are equivalent when their performance is averaged across all possible problems. This highlights the need for exploiting problem-specific knowledge to achieve better than random performance. In this paper we present a general framework covering more search scenarios. In addition to the optimization scenarios addressed in the NFL results, this framework covers multi-armed bandit problems and evolution of multiple co-evolving players. As a particular instance of the latter, it covers "self-play" problems. In these problems the set of players work together to produce a champion, who then engages one or more antagonists in a subsequent multi-player game. In contrast to the traditional optimization case where the NFL results hold, we show that in self-play there are free lunches: in coevolution some algorithms have better performance than other algorithms, averaged across all possible problems. We consider the implications of these results to biology where there is no champion.

Performance improvement of eight-state continuous-variable quantum key distribution with an optical amplifier

NASA Astrophysics Data System (ADS)

Guo, Ying; Li, Renjie; Liao, Qin; Zhou, Jian; Huang, Duan

2018-02-01

Discrete modulation is proven to be beneficial to improving the performance of continuous-variable quantum key distribution (CVQKD) in long-distance transmission. In this paper, we suggest a construct to improve the maximal generated secret key rate of discretely modulated eight-state CVQKD using an optical amplifier (OA) with a slight cost of transmission distance. In the proposed scheme, an optical amplifier is exploited to compensate imperfection of Bob's apparatus, so that the generated secret key rate of eight-state protocol is enhanced. Specifically, we investigate two types of optical amplifiers, phase-insensitive amplifier (PIA) and phase-sensitive amplifier (PSA), and thereby obtain approximately equivalent improved performance for eight-state CVQKD system when applying these two different amplifiers. Numeric simulation shows that the proposed scheme can well improve the generated secret key rate of eight-state CVQKD in both asymptotic limit and finite-size regime. We also show that the proposed scheme can achieve the relatively high-rate transmission at long-distance communication system.

Universal microfluidic automaton for autonomous sample processing: application to the Mars Organic Analyzer.

PubMed

Kim, Jungkyu; Jensen, Erik C; Stockton, Amanda M; Mathies, Richard A

2013-08-20

A fully integrated multilayer microfluidic chemical analyzer for automated sample processing and labeling, as well as analysis using capillary zone electrophoresis is developed and characterized. Using lifting gate microfluidic control valve technology, a microfluidic automaton consisting of a two-dimensional microvalve cellular array is fabricated with soft lithography in a format that enables facile integration with a microfluidic capillary electrophoresis device. The programmable sample processor performs precise mixing, metering, and routing operations that can be combined to achieve automation of complex and diverse assay protocols. Sample labeling protocols for amino acid, aldehyde/ketone and carboxylic acid analysis are performed automatically followed by automated transfer and analysis by the integrated microfluidic capillary electrophoresis chip. Equivalent performance to off-chip sample processing is demonstrated for each compound class; the automated analysis resulted in a limit of detection of ~16 nM for amino acids. Our microfluidic automaton provides a fully automated, portable microfluidic analysis system capable of autonomous analysis of diverse compound classes in challenging environments.

Ultra-low-noise transition edge sensors for the SAFARI L-band on SPICA

NASA Astrophysics Data System (ADS)

Goldie, D. J.; Gao, J. R.; Glowacka, D. M.; Griffin, D. K.; Hijmering, R.; Khosropanah, P.; Jackson, B. D.; Mauskopf, P. D.; Morozov, D.; Murphy, J. A.; Ridder, M.; Trappe, N.; O'Sullivan, C.; Withington, S.

2012-09-01

The Far-Infrared Fourier transform spectrometer instrument SAFARI-SPICA which will operate with cooled optics in a low-background space environment requires ultra-sensitive detector arrays with high optical coupling efficiencies over extremely wide bandwidths. In earlier papers we described the design, fabrication and performance of ultra-low-noise Transition Edge Sensors (TESs) operated close to 100mk having dark Noise Equivalent Powers (NEPs) of order 4 × 10-19W/√Hz close to the phonon noise limit and an improvement of two orders of magnitude over TESs for ground-based applications. Here we describe the design, fabrication and testing of 388-element arrays of MoAu TESs integrated with far-infrared absorbers and optical coupling structures in a geometry appropriate for the SAFARI L-band (110 - 210 μm). The measured performance shows intrinsic response time τ ~ 11ms and saturation powers of order 10 fW, and a dark noise equivalent powers of order 7 × 10-19W/√Hz. The 100 × 100μm2 MoAu TESs have transition temperatures of order 110mK and are coupled to 320×320μm2 thin-film β-phase Ta absorbers to provide impedance matching to the incoming fields. We describe results of dark tests (i.e without optical power) to determine intrinsic pixel characteristics and their uniformity, and measurements of the optical performance of representative pixels operated with flat back-shorts coupled to pyramidal horn arrays. The measured and modeled optical efficiency is dominated by the 95Ω sheet resistance of the Ta absorbers, indicating a clear route to achieve the required performance in these ultra-sensitive detectors.

Motor equivalence during multi-finger accurate force production

PubMed Central

Mattos, Daniela; Schöner, Gregor; Zatsiorsky, Vladimir M.; Latash, Mark L.

2014-01-01

We explored stability of multi-finger cyclical accurate force production action by analysis of responses to small perturbations applied to one of the fingers and inter-cycle analysis of variance. Healthy subjects performed two versions of the cyclical task, with and without an explicit target. The “inverse piano” apparatus was used to lift/lower a finger by 1 cm over 0.5 s; the subjects were always instructed to perform the task as accurate as they could at all times. Deviations in the spaces of finger forces and modes (hypothetical commands to individual fingers) were quantified in directions that did not change total force (motor equivalent) and in directions that changed the total force (non-motor equivalent). Motor equivalent deviations started immediately with the perturbation and increased progressively with time. After a sequence of lifting-lowering perturbations leading to the initial conditions, motor equivalent deviations were dominating. These phenomena were less pronounced for analysis performed with respect to the total moment of force with respect to an axis parallel to the forearm/hand. Analysis of inter-cycle variance showed consistently higher variance in a subspace that did not change the total force as compared to the variance that affected total force. We interpret the results as reflections of task-specific stability of the redundant multi-finger system. Large motor equivalent deviations suggest that reactions of the neuromotor system to a perturbation involve large changes of neural commands that do not affect salient performance variables, even during actions with the purpose to correct those salient variables. Consistency of the analyses of motor equivalence and variance analysis provides additional support for the idea of task-specific stability ensured at a neural level. PMID:25344311

Design and performance of mobile terminal for North American MSAT network

NASA Technical Reports Server (NTRS)

Fuji, Tsuyoshi; Tsuchiya, Makio; Isota, Yoji; Aoki, Katsuhiko

1995-01-01

The mobile terminal (MT), which can be selected for various applications, i.e. land mobile, transportable, fixed site, and maritime use, has been developed. Medium gain and high gain antennas are available. The MT can support circuit switched voice and data service. Additionally, cellular roaming service, net radio, and Group 3 facsimile services are optionally provided. A Mitsubishi handheld portable phone can be used as a stand-alone portable cellular-only phone or it can provide MSAT voice service when connected to MT. The MT which operates in L-band (1.5 GHz/1.6 GHz) satisfies equivalent isotropically radiated power (EIRP) of 12.5 dBW minimum and G/T of -16 dB/K minimum for medium gain system and -12 dB/K for high gain system. The excellent performance of transmit phase noise and bit error rate is achieved by using new technologies.

Oxygen Reduction at Very Low Overpotential on Nanoporous Ag Catalysts

DOE PAGES

Zhou, Yang; Lu, Qi; Zhuang, Zhongbin; ...

2015-05-07

Here we report a monolithic nanoporous Ag (np-Ag) material, synthesized using the dealloying method, as high-performance catalysts for ORR in alkaline media. As shown in Scheme 1, when there is insufficient potential input, the O 2 molecules are more likely to rebound off from a planar electrode surface (i.e. bulk polycrystalline metal, films made from nanoparticles or nanowires) before they could be reduced. In contrast, they are more likely to be trapped inside the monolithic nanoporous structure, contacting with catalytic surface for multiple time, which greatly enhances the chance for them to be fully reduced. As a result, the np-Agmore » catalyst is able to achieve an equivalent or better ORR performance than the state-of the-art Pt/C catalyst at low overpotentials, which is most desired in electrochemical energy applications for maximizing efficiency.« less

Cluster Correspondence Analysis.

PubMed

van de Velden, M; D'Enza, A Iodice; Palumbo, F

2017-03-01

A method is proposed that combines dimension reduction and cluster analysis for categorical data by simultaneously assigning individuals to clusters and optimal scaling values to categories in such a way that a single between variance maximization objective is achieved. In a unified framework, a brief review of alternative methods is provided and we show that the proposed method is equivalent to GROUPALS applied to categorical data. Performance of the methods is appraised by means of a simulation study. The results of the joint dimension reduction and clustering methods are compared with the so-called tandem approach, a sequential analysis of dimension reduction followed by cluster analysis. The tandem approach is conjectured to perform worse when variables are added that are unrelated to the cluster structure. Our simulation study confirms this conjecture. Moreover, the results of the simulation study indicate that the proposed method also consistently outperforms alternative joint dimension reduction and clustering methods.

Simulation of proportional control of hydraulic actuator using digital hydraulic valves

NASA Astrophysics Data System (ADS)

Raghuraman, D. R. S.; Senthil Kumar, S.; Kalaiarasan, G.

2017-11-01

Fluid power systems using oil hydraulics in earth moving and construction equipment have been using proportional and servo control valves for a long time to achieve precise and accurate position control backed by system performance. Such valves are having feedback control in them and exhibit good response, sensitivity and fine control of the actuators. Servo valves and proportional valves are possessing less hysteresis when compared to on-off type valves, but when the servo valve spools get stuck in one position, a high frequency called as jitter is employed to bring the spool back, whereas in on-off type valves it requires lesser technology to retract the spool. Hence on-off type valves are used in a technology known as digital valve technology, which caters to precise control on slow moving loads with fast switching times and with good flow and pressure control mimicking the performance of an equivalent “proportional valve” or “servo valve”.

Characterizing Adsorption Performance of Granular Activated Carbon with Permittivity.

PubMed

Yang, Yang; Shi, Chao; Zhang, Yi; Ye, Jinghua; Zhu, Huacheng; Huang, Kama

2017-03-07

A number of studies have achieved the consensus that microwave thermal technology can regenerate the granular activated carbon (GAC) more efficiently and energy-conservatively than other technologies. In particular, in the microwave heating industry, permittivity is a crucial parameter. This paper developed two equivalent models to establish the relationship between effective complex permittivity and pore volume of the GAC. It is generally based on Maxwell-Garnett approximation (MGA) theory. With two different assumptions in the model, two quantificational expressions were derived, respectively. Permittivity measurements and Brunauer-Emmett-Teller (BET) testing had been introduced in the experiments. Results confirmed the two expressions, which were extremely similar. Theoretical and experimental graphs were matched. This paper set up a bridge which links effective complex permittivity and pore volume of the GAC. Furthermore, it provides a potential and convenient method for the rapid assisted characterization of the GAC in its adsorption performance.

Characterizing Adsorption Performance of Granular Activated Carbon with Permittivity

PubMed Central

Yang, Yang; Shi, Chao; Zhang, Yi; Ye, Jinghua; Zhu, Huacheng; Huang, Kama

2017-01-01

A number of studies have achieved the consensus that microwave thermal technology can regenerate the granular activated carbon (GAC) more efficiently and energy-conservatively than other technologies. In particular, in the microwave heating industry, permittivity is a crucial parameter. This paper developed two equivalent models to establish the relationship between effective complex permittivity and pore volume of the GAC. It is generally based on Maxwell-Garnett approximation (MGA) theory. With two different assumptions in the model, two quantificational expressions were derived, respectively. Permittivity measurements and Brunauer–Emmett–Teller (BET) testing had been introduced in the experiments. Results confirmed the two expressions, which were extremely similar. Theoretical and experimental graphs were matched. This paper set up a bridge which links effective complex permittivity and pore volume of the GAC. Furthermore, it provides a potential and convenient method for the rapid assisted characterization of the GAC in its adsorption performance. PMID:28772628

Ultrasensitive plano-concave optical microresonators for ultrasound sensing

NASA Astrophysics Data System (ADS)

Guggenheim, James A.; Li, Jing; Allen, Thomas J.; Colchester, Richard J.; Noimark, Sacha; Ogunlade, Olumide; Parkin, Ivan P.; Papakonstantinou, Ioannis; Desjardins, Adrien E.; Zhang, Edward Z.; Beard, Paul C.

2017-11-01

Highly sensitive broadband ultrasound detectors are needed to expand the capabilities of biomedical ultrasound, photoacoustic imaging and industrial ultrasonic non-destructive testing techniques. Here, a generic optical ultrasound sensing concept based on a novel plano-concave polymer microresonator is described. This achieves strong optical confinement (Q-factors > 105) resulting in very high sensitivity with excellent broadband acoustic frequency response and wide directivity. The concept is highly scalable in terms of bandwidth and sensitivity. To illustrate this, a family of microresonator sensors with broadband acoustic responses up to 40 MHz and noise-equivalent pressures as low as 1.6 mPa per √Hz have been fabricated and comprehensively characterized in terms of their acoustic performance. In addition, their practical application to high-resolution photoacoustic and ultrasound imaging is demonstrated. The favourable acoustic performance and design flexibility of the technology offers new opportunities to advance biomedical and industrial ultrasound-based techniques.

Strong scaling of general-purpose molecular dynamics simulations on GPUs

NASA Astrophysics Data System (ADS)

Glaser, Jens; Nguyen, Trung Dac; Anderson, Joshua A.; Lui, Pak; Spiga, Filippo; Millan, Jaime A.; Morse, David C.; Glotzer, Sharon C.

2015-07-01

We describe a highly optimized implementation of MPI domain decomposition in a GPU-enabled, general-purpose molecular dynamics code, HOOMD-blue (Anderson and Glotzer, 2013). Our approach is inspired by a traditional CPU-based code, LAMMPS (Plimpton, 1995), but is implemented within a code that was designed for execution on GPUs from the start (Anderson et al., 2008). The software supports short-ranged pair force and bond force fields and achieves optimal GPU performance using an autotuning algorithm. We are able to demonstrate equivalent or superior scaling on up to 3375 GPUs in Lennard-Jones and dissipative particle dynamics (DPD) simulations of up to 108 million particles. GPUDirect RDMA capabilities in recent GPU generations provide better performance in full double precision calculations. For a representative polymer physics application, HOOMD-blue 1.0 provides an effective GPU vs. CPU node speed-up of 12.5 ×.

Study of the cost/benefit tradeoffs for reducing the energy consumption of the commercial air transportation system

NASA Technical Reports Server (NTRS)

Hopkins, J. P.

1976-01-01

Practical means were assessed for achieving reduced fuel consumption in commercial air transportation. Five areas were investigated: current aircraft types, revised operational procedures, modifications to current aircraft, derivatives of current aircraft and new near-term fuel conservative aircraft. As part of a multiparticipant coordinated effort, detailed performance and operating cost data in each of these areas were supplied to the contractor responsible for the overall analysis of the cost/benefit tradeoffs for reducing the energy consumption of the domestic commercial air transportation system. A follow-on study was performed to assess the potential of an advanced turboprop transport aircraft concept. To provide a valid basis for comparison, an equivalent turbofan transport aircraft concept incorporating equal technology levels was also derived. The aircraft as compared on the basis of weight, size, fuel utilization, operational characteristics and costs.

Link performance optimization for digital satellite broadcasting systems

NASA Astrophysics Data System (ADS)

de Gaudenzi, R.; Elia, C.; Viola, R.

The authors introduce the concept of digital direct satellite broadcasting (D-DBS), which allows unprecedented flexibility by providing a large number of audiovisual services. The concept assumes an information rate of 40 Mb/s, which is compatible with practically all present-day transponders. After discussion of the general system concept, the results of transmission system optimization are presented. Channel and interference effects are taken into account. Numerical results show that the scheme with the best performance is trellis-coded 8-PSK (phase shift keying) modulation concatenated with Reed-Solomon block code. For a net data rate of 40 Mb/s a bit error rate of 10-10 can be achieved with an equivalent bit energy to noise density of 9.5 dB, including channel, interference, and demodulator impairments. A link budget analysis shows how a medium-power direct-to-home TV satellite can provide multimedia services to users equipped with small (60-cm) dish antennas.

A comparison of quantum limited dose and noise equivalent dose

NASA Astrophysics Data System (ADS)

Job, Isaias D.; Boyce, Sarah J.; Petrillo, Michael J.; Zhou, Kungang

2016-03-01

Quantum-limited-dose (QLD) and noise-equivalent-dose (NED) are performance metrics often used interchangeably. Although the metrics are related, they are not equivalent unless the treatment of electronic noise is carefully considered. These metrics are increasingly important to properly characterize the low-dose performance of flat panel detectors (FPDs). A system can be said to be quantum-limited when the Signal-to-noise-ratio (SNR) is proportional to the square-root of x-ray exposure. Recent experiments utilizing three methods to determine the quantum-limited dose range yielded inconsistent results. To investigate the deviation in results, generalized analytical equations are developed to model the image processing and analysis of each method. We test the generalized expression for both radiographic and fluoroscopic detectors. The resulting analysis shows that total noise content of the images processed by each method are inherently different based on their readout scheme. Finally, it will be shown that the NED is equivalent to the instrumentation-noise-equivalent-exposure (INEE) and furthermore that the NED is derived from the quantum-noise-only method of determining QLD. Future investigations will measure quantum-limited performance of radiographic panels with a modified readout scheme to allow for noise improvements similar to measurements performed with fluoroscopic detectors.

Improved Equivalent Linearization Implementations Using Nonlinear Stiffness Evaluation

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Muravyov, Alexander A.

2001-01-01

This report documents two new implementations of equivalent linearization for solving geometrically nonlinear random vibration problems of complicated structures. The implementations are given the acronym ELSTEP, for "Equivalent Linearization using a STiffness Evaluation Procedure." Both implementations of ELSTEP are fundamentally the same in that they use a novel nonlinear stiffness evaluation procedure to numerically compute otherwise inaccessible nonlinear stiffness terms from commercial finite element programs. The commercial finite element program MSC/NASTRAN (NASTRAN) was chosen as the core of ELSTEP. The FORTRAN implementation calculates the nonlinear stiffness terms and performs the equivalent linearization analysis outside of NASTRAN. The Direct Matrix Abstraction Program (DMAP) implementation performs these operations within NASTRAN. Both provide nearly identical results. Within each implementation, two error minimization approaches for the equivalent linearization procedure are available - force and strain energy error minimization. Sample results for a simply supported rectangular plate are included to illustrate the analysis procedure.

5 CFR 300.605 - Creditable service.

Code of Federal Regulations, 2011 CFR

2011-01-01

... effect when the non-GS service was performed. The equivalent GS grade is the GS grade with a... higher grade (or equivalent) in positions to which appointed in the Federal civilian service is... General Schedule (GS) is credited at the equivalent GS grade by comparing the candidate's rate of basic...

5 CFR 300.605 - Creditable service.

Code of Federal Regulations, 2013 CFR

2013-01-01

... effect when the non-GS service was performed. The equivalent GS grade is the GS grade with a... higher grade (or equivalent) in positions to which appointed in the Federal civilian service is... General Schedule (GS) is credited at the equivalent GS grade by comparing the candidate's rate of basic...

5 CFR 300.605 - Creditable service.

Code of Federal Regulations, 2010 CFR

2010-01-01

... effect when the non-GS service was performed. The equivalent GS grade is the GS grade with a... higher grade (or equivalent) in positions to which appointed in the Federal civilian service is... General Schedule (GS) is credited at the equivalent GS grade by comparing the candidate's rate of basic...

5 CFR 300.605 - Creditable service.

Code of Federal Regulations, 2012 CFR

2012-01-01

... effect when the non-GS service was performed. The equivalent GS grade is the GS grade with a... higher grade (or equivalent) in positions to which appointed in the Federal civilian service is... General Schedule (GS) is credited at the equivalent GS grade by comparing the candidate's rate of basic...

Analysis of the performance of the space ultravacuum research facility in attached and free-flyer mode

NASA Technical Reports Server (NTRS)

Naumann, Robert J.

1988-01-01

The old concept of using the wake of a spacecraft to obtain an ultrahigh vacuum is revisited with a somewhat different emphasis. Since it is possible to configure a wake shield so that a surface of interest does not subtend any walls that could become contaminated, it appears that it should be possible to achieve a contamination-free, ultrahigh vacuum capability with infinite pumping speed even in the presence of high heat loads and moderate gas loads. With the new interest in developing thin films with precision controlled synthetic microstructures such as superlattices, mixed metal oxide high temperature superconductors, rare-earth magneto-optical devices, and nano-crystalline alloys, the ability to work with a variety of different materials without cross contamination should be of significance. This paper analyzes the performance of the conceptual design for a Space Ultravacuum Research Facility (SURF), both in a Shuttle-attached mode and as a free-flyer. It is shown that even in the Shuttle-attached mode, it should be possible to obtain vacuum levels equivalent to 10 to the -10 Torr with O and N2 as the primary constituents. This should be sufficient to demonstrate the feasibility of the concept, particularly the infinite pumping speed and virtual elimination of contamination aspects. As a free-flyer the SURF will be limited primarily by the gas load associated with the process being performed. For chemical beam epitaxy (CBE) it is shown that equivalent vacuum levels of 10 to the -14 Torr should be possible at 300 km.

Performance testing of a mid-infrared spectroscopic system for clinical chemistry applications utilising an ultra-broadband tunable EC-QCL radiation source

NASA Astrophysics Data System (ADS)

Grafen, M.; Nalpantidis, K.; Ihrig, D.; Heise, H. M.; Ostendorf, A.

2016-03-01

Mid-infrared (MIR) spectroscopy is a valuable analytical method for patient monitoring within point-of-care diagnostics. For implementation, quantum cascade lasers (QCL) appear to be most suited regarding miniaturization, complexity and eventually also costs. External cavity (EC) - QCLs offer broad tuning ranges and recently, ultra-broadly tunable systems covering spectral ranges around the mid-infrared fingerprint region became commercially available. Using such a system, transmission spectra from the wavenumber interval of 780 to 1920 cm-1, using a thermoelectrically cooled MCT-detector, were recorded while switching the aqueous glucose concentrations between 0, 50 and 100 mg/dL. In order to optimize the system performance, a multi-parameter study was carried out, varying laser pulse width, duty cycle, sweep speed and the optical sample pathlength for scoring the absorbance noise. Exploratory factor analysis with pattern recognition tools (PCA, LDA) was used for the raw data, providing more than 10 significantly contributing factors. With the glucose signal causing 20 % of the total variance, further factors include short-term drift possibly related to thermal effects, long-term drift due to varying atmospheric water vapour in the lab, as well as wavenumber shifts and drifts of the single tuners. For performance testing, the noise equivalent concentration was estimated based on cross-validated Partial-Least Squares (PLS) predictions and the a-posteriori obtained scores of the factor analysis. Based on the optimized parameters, a noise equivalent glucose concentration of 1.5 mg/dL was achieved.

The Marriage of Residential Energy Codes and Rating Systems: Conflict Resolution or Just Conflict?

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

Taylor, Zachary T.; Mendon, Vrushali V.

2014-08-21

After three decades of coexistence at a distance, model residential energy codes and residential energy rating systems have come together in the 2015 International Energy Conservation Code. At the October, 2013, International Code Council’s Public Comment Hearing, a new compliance path based on an Energy Rating Index was added to the IECC. Although not specifically named in the code, RESNET’s HERS rating system is the likely candidate Index for most jurisdictions. While HERS has been a mainstay in various beyond-code programs for many years, its direct incorporation into the most popular model energy code raises questions about the equivalence ofmore » a HERS-based compliance path and the traditional IECC performance compliance path, especially because the two approaches use different efficiency metrics, are governed by different simulation rules, and have different scopes with regard to energy impacting house features. A detailed simulation analysis of more than 15,000 house configurations reveals a very large range of HERS Index values that achieve equivalence with the IECC’s performance path. This paper summarizes the results of that analysis and evaluates those results against the specific Energy Rating Index values required by the 2015 IECC. Based on the home characteristics most likely to result in disparities between HERS-based compliance and performance path compliance, potential impacts on the compliance process, state and local adoption of the new code, energy efficiency in the next generation of homes subject to this new code, and future evolution of model code formats are discussed.« less

[Applications of habitat equivalency analysis in ecological damage assessment of oil spill incident].

PubMed

Yang, Yin; Han, Da-xiong; Wang, Hai-yan

2011-08-01

Habitat equivalency analysis (HEA) is one of the methods commonly used by U.S. National Oceanic and Atmospheric Administration in natural resources damage assessment, but rarely applied in China. Based on the theory of HEA and the assessment practices of domestic oil spill incidents, a modification on the HEA was made in this paper, and applied to calculate the habitat value in oil spill incidents. According to the data collected from an oil spill incident in China, the modified HEA was applied in a case study to scale the compensatory-restoration. By introducing the ecological service equivalent factor to transfer various habitats, it was achieved to value of the injured habitats in ecological damage assessment of oil spill incident.

A statistical assessment of differences and equivalences between genetically modified and reference plant varieties

PubMed Central

2011-01-01

Background Safety assessment of genetically modified organisms is currently often performed by comparative evaluation. However, natural variation of plant characteristics between commercial varieties is usually not considered explicitly in the statistical computations underlying the assessment. Results Statistical methods are described for the assessment of the difference between a genetically modified (GM) plant variety and a conventional non-GM counterpart, and for the assessment of the equivalence between the GM variety and a group of reference plant varieties which have a history of safe use. It is proposed to present the results of both difference and equivalence testing for all relevant plant characteristics simultaneously in one or a few graphs, as an aid for further interpretation in safety assessment. A procedure is suggested to derive equivalence limits from the observed results for the reference plant varieties using a specific implementation of the linear mixed model. Three different equivalence tests are defined to classify any result in one of four equivalence classes. The performance of the proposed methods is investigated by a simulation study, and the methods are illustrated on compositional data from a field study on maize grain. Conclusions A clear distinction of practical relevance is shown between difference and equivalence testing. The proposed tests are shown to have appropriate performance characteristics by simulation, and the proposed simultaneous graphical representation of results was found to be helpful for the interpretation of results from a practical field trial data set. PMID:21324199

Optimization of oncological {sup 18}F-FDG PET/CT imaging based on a multiparameter analysis

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

Menezes, Vinicius O., E-mail: vinicius@radtec.com.br; Machado, Marcos A. D.; Queiroz, Cleiton C.

2016-02-15

Purpose: This paper describes a method to achieve consistent clinical image quality in {sup 18}F-FDG scans accounting for patient habitus, dose regimen, image acquisition, and processing techniques. Methods: Oncological PET/CT scan data for 58 subjects were evaluated retrospectively to derive analytical curves that predict image quality. Patient noise equivalent count rate and coefficient of variation (CV) were used as metrics in their analysis. Optimized acquisition protocols were identified and prospectively applied to 179 subjects. Results: The adoption of different schemes for three body mass ranges (<60 kg, 60–90 kg, >90 kg) allows improved image quality with both point spread functionmore » and ordered-subsets expectation maximization-3D reconstruction methods. The application of this methodology showed that CV improved significantly (p < 0.0001) in clinical practice. Conclusions: Consistent oncological PET/CT image quality on a high-performance scanner was achieved from an analysis of the relations existing between dose regimen, patient habitus, acquisition, and processing techniques. The proposed methodology may be used by PET/CT centers to develop protocols to standardize PET/CT imaging procedures and achieve better patient management and cost-effective operations.« less

A Quasi-Experimental Study on Using Short Stories: Statistical and Inferential Analyses on the Non-English Major University Students' Speaking and Writing Achievements

ERIC Educational Resources Information Center

Iman, Jaya Nur

2017-01-01

This research was conducted to find out whether or not using short stories significantly improve the speaking and writing achievements. A quasi-experimental study of non-equivalent pretest-posttest control group design or comparison group design was used in this research. The population of this research was the all first semester undergraduate…

Assessment of the Effects of Problem Solving Instructional Strategies on Students' Achievement and Retention in Chemistry with Respect to Location in Rivers State

ERIC Educational Resources Information Center

Nbina, Jacobson Barineka; Obomanu, B. Joseph

2011-01-01

We report a study focused on how problem-solving instructional strategies would affect students' achievement and retention in Chemistry with particular reference to River State. A pre-test, post-test, non-equivalent control group design was adopted. Two research questions and two hypotheses were respectively answered and tested. Purposive and…

The Effect of Concept Mapping-Guided Discovery Integrated Teaching Approach on Chemistry Students' Achievement and Retention

ERIC Educational Resources Information Center

Fatokun, K. V. F.; Eniayeju, P. A.

2014-01-01

This study investigates the effects of Concept Mapping-Guided Discovery Integrated Teaching Approach on the achievement and retention of chemistry students. The sample comprised 162 Senior Secondary two (SS 2) students drawn from two Science Schools in Nasarawa State, Central Nigeria with equivalent mean scores of 9.68 and 9.49 in their pre-test.…

Comparative Effects of Concept Mapping and Cooperative Learning Strategies on Senior Secondary School Students' Achievement in Mathematics-Trigonometry in Kano State, Nigeria

ERIC Educational Resources Information Center

Bot, Thomas D.; Eze, John E.

2016-01-01

This article presents the findings from an experimental study on the effectiveness of concept mapping and cooperative learning strategies on SSII students' achievement in trigonometry in mathematics. The research design used in conducting the study was quasi-experimental pre-test and post-test non-equivalent control group. The sample consisted of…

49 CFR 381.510 - May the FMCSA end a pilot program before its scheduled completion date?

Code of Federal Regulations, 2010 CFR

2010-10-01

... achieving a level of safety that is at least equivalent to the level of safety that would be achieved by... 49 Transportation 5 2010-10-01 2010-10-01 false May the FMCSA end a pilot program before its... Pilot Programs § 381.510 May the FMCSA end a pilot program before its scheduled completion date? The...

Mirror-Image Equivalence and Interhemispheric Mirror-Image Reversal

PubMed Central

Corballis, Michael C.

2018-01-01

Mirror-image confusions are common, especially in children and in some cases of neurological impairment. They can be a special impediment in activities such as reading and writing directional scripts, where mirror-image patterns (such as b and d) must be distinguished. Treating mirror images as equivalent, though, can also be adaptive in the natural world, which carries no systematic left-right bias and where the same object or event can appear in opposite viewpoints. Mirror-image equivalence and confusion are natural consequences of a bilaterally symmetrical brain. In the course of learning, mirror-image equivalence may be established through a process of symmetrization, achieved through homotopic interhemispheric exchange in the formation of memory circuits. Such circuits would not distinguish between mirror images. Learning to discriminate mirror-image discriminations may depend either on existing brain asymmetries, or on extensive learning overriding the symmetrization process. The balance between mirror-image equivalence and mirror-image discrimination may nevertheless be precarious, with spontaneous confusions or reversals, such as mirror writing, sometimes appearing naturally or as a manifestation of conditions like dyslexia. PMID:29706878

Cross-Language Measurement Equivalence of Parenting Measures for use with Mexican American Populations

PubMed Central

Nair, Rajni L.; White, Rebecca M.B.; Knight, George P.; Roosa, Mark W.

2009-01-01

Increasing diversity among families in the United States often necessitates the translation of common measures into various languages. However, even when great care is taken during translations, empirical evaluations of measurement equivalence are necessary. The current study demonstrates the analytic techniques researchers should use to evaluate the measurement equivalence of translated measures. To this end we investigated the cross-language measurement equivalence of several common parenting measures in a sample of 749 Mexican American families. The item invariance results indicated similarity of factor structures across language groups for each of the parenting measures for both mothers and children. Construct validity tests indicated similar slope relations between each of the four parenting measures and the outcomes across the two language groups for both mothers and children. Equivalence in intercepts, however, was only achieved for some outcomes. These findings indicate that the use of these measures in both within group and between group analyses based on correlation/covariance structure is defensible, but researchers are cautioned against interpretations of mean level differences across these language groups. PMID:19803604

Mirror-Image Equivalence and Interhemispheric Mirror-Image Reversal.

PubMed

Corballis, Michael C

2018-01-01

Mirror-image confusions are common, especially in children and in some cases of neurological impairment. They can be a special impediment in activities such as reading and writing directional scripts, where mirror-image patterns (such as b and d ) must be distinguished. Treating mirror images as equivalent, though, can also be adaptive in the natural world, which carries no systematic left-right bias and where the same object or event can appear in opposite viewpoints. Mirror-image equivalence and confusion are natural consequences of a bilaterally symmetrical brain. In the course of learning, mirror-image equivalence may be established through a process of symmetrization, achieved through homotopic interhemispheric exchange in the formation of memory circuits. Such circuits would not distinguish between mirror images. Learning to discriminate mirror-image discriminations may depend either on existing brain asymmetries, or on extensive learning overriding the symmetrization process. The balance between mirror-image equivalence and mirror-image discrimination may nevertheless be precarious, with spontaneous confusions or reversals, such as mirror writing, sometimes appearing naturally or as a manifestation of conditions like dyslexia.

A National Study of the Relationship between Home Access to a Computer and Academic Performance Scores of Grade 12 U.S. Science Students: An Analysis of the 2009 NAEP Data

NASA Astrophysics Data System (ADS)

Coffman, Mitchell Ward

The purpose of this dissertation was to examine the relationship between student access to a computer at home and academic achievement. The 2009 National Assessment of Educational Progress (NAEP) dataset was probed using the National Data Explorer (NDE) to investigate correlations in the subsets of SES, Parental Education, Race, and Gender as it relates to access of a home computer and improved performance scores for U.S. public school grade 12 science students. A causal-comparative approach was employed seeking clarity on the relationship between home access and performance scores. The influence of home access cannot overcome the challenges students of lower SES face. The achievement gap, or a second digital divide, for underprivileged classes of students, including minorities does not appear to contract via student access to a home computer. Nonetheless, in tests for significance, statistically significant improvement in science performance scores was reported for those having access to a computer at home compared to those not having access. Additionally, regression models reported evidence of correlations between and among subsets of controls for the demographic factors gender, race, and socioeconomic status. Variability in these correlations was high; suggesting influence from unobserved factors may have more impact upon the dependent variable. Having access to a computer at home increases performance scores for grade 12 general science students of all races, genders and socioeconomic levels. However, the performance gap is roughly equivalent to the existing performance gap of the national average for science scores, suggesting little influence from access to a computer on academic achievement. The variability of scores reported in the regression analysis models reflects a moderate to low effect, suggesting an absence of causation. These statistical results are accurate and confirm the literature review, whereby having access to a computer at home and the predictor variables were found to have a significant impact on performance scores, although the data presented suggest computer access at home is less influential upon performance scores than poverty and its correlates.

Caliste 64: detection unit of a spectro imager array for a hard x-ray space telescope

NASA Astrophysics Data System (ADS)

Limousin, O.; Meuris, A.; Lugiez, F.; Gevin, Olivier; Pinsard, F.; Blondel, C.; Le Mer, I.; Delagnes, E.; Vassal, M. C.; Soufflet, F.; Bocage, R.; Penquer, A.; Billot, M.

2017-11-01

In the frame of the hard X-ray Simbol-X observatory, a joint CNES-ASI space mission to be flown in 2014, a prototype of miniature Cd(Zn)Te camera equipped with 64 pixels has been designed. The device, called Caliste 64, is a spectro-imager with high resolution event timetagging capability. Caliste 64 integrates a Cd(Zn)Te semiconductor detector with segmented electrode and its front-end electronics made of 64 independent analog readout channels. This 1 × 1 × 2 cm3 camera, able to detect photons in the range from 2 keV up to 250 keV, is an elementary detection unit juxtaposable on its four sides. Consequently, large detector array can be made assembling a mosaic of Caliste 64 units. Electronics readout module is achieved by stacking four IDeF-X V1.1 ASICs, perpendicular to the detection plane. We achieved good noise performances, with a mean Equivalent Noise Charge of 65 electrons rms over the 64 channels. For the first prototypes, we chose Pt//CdTe//Al/Ti/Au Schottky detectors because of their very low dark current and excellent spectroscopic performances. Recently a Caliste 64 prototype has been also equipped with a 2 mm thick Au//CdZnTe//Au detector. This paper presents the performances of these four prototypes and demonstrates spectral performances better than 1 keV fwhm at 59.54 keV when the samples are moderately cooled down to -10°C.

Electrochemical model based charge optimization for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Pramanik, Sourav; Anwar, Sohel

2016-05-01

In this paper, we propose the design of a novel optimal strategy for charging the lithium-ion battery based on electrochemical battery model that is aimed at improved performance. A performance index that aims at minimizing the charging effort along with a minimum deviation from the rated maximum thresholds for cell temperature and charging current has been defined. The method proposed in this paper aims at achieving a faster charging rate while maintaining safe limits for various battery parameters. Safe operation of the battery is achieved by including the battery bulk temperature as a control component in the performance index which is of critical importance for electric vehicles. Another important aspect of the performance objective proposed here is the efficiency of the algorithm that would allow higher charging rates without compromising the internal electrochemical kinetics of the battery which would prevent abusive conditions, thereby improving the long term durability. A more realistic model, based on battery electro-chemistry has been used for the design of the optimal algorithm as opposed to the conventional equivalent circuit models. To solve the optimization problem, Pontryagins principle has been used which is very effective for constrained optimization problems with both state and input constraints. Simulation results show that the proposed optimal charging algorithm is capable of shortening the charging time of a lithium ion cell while maintaining the temperature constraint when compared with the standard constant current charging. The designed method also maintains the internal states within limits that can avoid abusive operating conditions.

Standards for midwife practitioners of external cephalic version: A Delphi study.

PubMed

Walker, Shawn; Perilakalathil, Prasanth; Moore, Jenny; Gibbs, Claire L; Reavell, Karen; Crozier, Kenda

2015-05-01

expansion of advanced and specialist midwifery practitioner roles across professional boundaries requires an evidence-based framework to evaluate achievement and maintenance of competency. In order to develop the role of Breech Specialist Midwife to include the autonomous performance of external cephalic version within one hospital, guidance was required on standards of training and skill development, particularly in the use of ultrasound. a three-round Delphi survey was used to determine consensus among an expert panel, including highly experienced obstetric and midwife practitioners, as well as sonographers. The first round used mostly open-ended questions to gather data, from which statements were formed and returned to the panel for evaluation in subsequent rounds. standards for achieving and maintaining competence to perform ECV, and in the use of basic third trimester ultrasound as part of this practice, should be the same for midwives and doctors. The maintenance of proficiency requires regular practice. midwives can appropriately expand their sphere of practice to include ECV and basic third trimester ultrasound, according to internal guidelines, following the completion of a competency-based training programme roughly equivalent to those used to guide obstetric training. Ideally, ECV services should be offered in organised clinics where individual practitioners in either profession are able to perform approximately 30 or more ECVs per year in order to maintain an appropriate level of skill. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of various types of stationary phases in non-aqueous reversed-phase high-performance liquid chromatography-mass spectrometry of glycerolipids in blackcurrant oil and its enzymatic hydrolysis mixture.

PubMed

Lísa, Miroslav; Holcapek, Michal; Sovová, Helena

2009-11-20

The selection of column packing during the development of high-performance liquid chromatography method is a crucial step to achieve sufficient chromatographic resolution of analyzed species in complex mixtures. Various stationary phases are tested in this paper for the analysis of complex mixture of triacylglycerols (TGs) in blackcurrant oil using non-aqueous reversed-phase (NARP) system with acetonitrile-2-propanol mobile phase. Conventional C(18) column in the total length of 45 cm is used for the separation of TGs according to their equivalent carbon number, the number and positions of double bonds and acyl chain lengths. The separation of TGs and their more polar hydrolysis products after the partial enzymatic hydrolysis of blackcurrant oil in one chromatographic run is achieved using conventional C(18) column. Retention times of TGs are reduced almost 10 times without the loss of the chromatographic resolution using ultra high-performance liquid chromatography with 1.7 microm C(18) particles. The separation in NARP system on C(30) column shows an unusual phenomenon, because the retention order of TGs changes depending on the column temperature, which is reported for the first time. The commercial monolithic column modified with C(18) is used for the fast analysis of TGs to increase the sample throughput but at cost of low resolution.

Combined modification by LiAl11O17 and NaAl11O17 to enhance the electrochemical performance of Li4Ti5O12

NASA Astrophysics Data System (ADS)

Zhang, Bo; Han, Jian-Ping; Wang, Li-Ying; Lun, Ning; Zhu, Hui-Ling; Yin, Long-Wei; Li, Hui; Qi, Yong-Xin; Bai, Yu-Jun

2018-07-01

The intrinsically moderate Li-ion diffusion coefficient and poor electronic conductivity of Li4Ti5O12 (LTO) restricts the practical application in Li-ion batteries. In view of the rapid two-dimensional diffusion channels in ionic conductor of LiNaAl22O34 for Li-ions, the LTO modified by combining equivalent molar ratio of LiAl11O17 with NaAl11O17 (LNAO) was fabricated by a simple reaction between LiNO3, Na2CO3, Al(NO3)3ṡ9H2O and LTO at various sintering temperatures. The product with a LNAO/LTO mass ratio of 0.0106 and calcined at 600 °C achieved reversible capacities of 163.8, 160.6, 156.5, 150.9, 132.9 and 163.4 mAh g-1 at the current rates of 100, 200, 400, 800, 1600 and 100 mA g-1, respectively. Even cycled 800 times at 500 mA g-1, a capacity of 147.9 mAh g-1 was retained. The outstanding cycling and rate performance is attributable to the simultaneously formed LNAO coating on the LTO particles and superficial Al3+ doping in the LTO, achieving combined improvement in the ionic and electronic conductivities of LTO and thus boosting the comprehensive electrochemical performance of LTO.

Left Ventricular Assist Device as a Bridge to Recovery for Patients With Advanced Heart Failure.

PubMed

Jakovljevic, Djordje G; Yacoub, Magdi H; Schueler, Stephan; MacGowan, Guy A; Velicki, Lazar; Seferovic, Petar M; Hothi, Sandeep; Tzeng, Bing-Hsiean; Brodie, David A; Birks, Emma; Tan, Lip-Bun

2017-04-18

Left ventricular assist devices (LVADs) have been used as an effective therapeutic option in patients with advanced heart failure, either as a bridge to transplantation, as destination therapy, or in some patients, as a bridge to recovery. This study evaluated whether patients undergoing an LVAD bridge-to-recovery protocol can achieve cardiac and physical functional capacities equivalent to those of healthy controls. Fifty-eight male patients-18 implanted with a continuous-flow LVAD, 16 patients with LVAD explanted (recovered patients), and 24 heart transplant candidates (HTx)-and 97 healthy controls performed a maximal graded cardiopulmonary exercise test with continuous measurements of respiratory gas exchange and noninvasive (rebreathing) hemodynamic data. Cardiac function was represented by peak exercise cardiac power output (mean arterial blood pressure × cardiac output) and functional capacity by peak exercise O 2 consumption. All patients demonstrated a significant exertional effort as demonstrated with the mean peak exercise respiratory exchange ratio >1.10. Peak exercise cardiac power output was significantly higher in healthy controls and explanted LVAD patients compared with other patients (healthy 5.35 ± 0.95 W; explanted 3.45 ± 0.72 W; LVAD implanted 2.37 ± 0.68 W; and HTx 1.31 ± 0.31 W; p < 0.05), as was peak O 2 consumption (healthy 36.4 ± 10.3 ml/kg/min; explanted 29.8 ± 5.9 ml/kg/min; implanted 20.5 ± 4.3 ml/kg/min; and HTx 12.0 ± 2.2 ml/kg/min; p < 0.05). In the LVAD explanted group, 38% of the patients achieved peak cardiac power output and 69% achieved peak O 2 consumption within the ranges of healthy controls. The authors have shown that a substantial number of patients who recovered sufficiently to allow explantation of their LVAD can even achieve cardiac and physical functional capacities nearly equivalent to those of healthy controls. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Physicochemical equivalence of generic antihypertensive medicines (EQUIMEDS): protocol for a quality of medicines assessment

PubMed Central

Redfern, Julie; Adedoyin, Rufus Adesoji; Ofori, Sandra; Anchala, Raghupathy; Ajay, Vamadevan S; De Andrade, Luciano; Zelaya, Jose; Kaur, Harparkash; Balabanova, Dina; Sani, Mahmoud U

2016-01-01

Background Prevention and optimal management of hypertension in the general population is paramount to the achievement of the World Heart Federation (WHF) goal of reducing premature cardiovascular disease (CVD) mortality by 25% by the year 2025 and widespread access to good quality antihypertensive medicines is a critical component for achieving the goal. Despite research and evidence relating to other medicines such as antimalarials and antibiotics, there is very little known about the quality of generic antihypertensive medicines in low-income and middle-income countries. The aim of this study was to determine the physicochemical equivalence (percentage of active pharmaceutical ingredient, API) of generic antihypertensive medicines available in the retail market of a developing country. Methods An observational design will be adopted, which includes literature search, landscape assessment, collection and analysis of medicine samples. To determine physicochemical equivalence, a multistage sampling process will be used, including (1) identification of the 2 most commonly prescribed classes of antihypertensive medicines prescribed in Nigeria; (2) identification of a random sample of 10 generics from within each of the 2 most commonly prescribed classes; (3) a geographical representative sampling process to identify a random sample of 24 retail outlets in Nigeria; (4) representative sample purchasing, processing to assess the quality of medicines, storage and transport; and (5) assessment of the physical and chemical equivalence of the collected samples compared to the API in the relevant class. In total, 20 samples from each of 24 pharmacies will be tested (total of 480 samples). Discussion Availability of and access to quality antihypertensive medicines globally is therefore a vital strategy needed to achieve the WHF 25×25 targets. However, there is currently a scarcity of knowledge about the quality of antihypertensive medicines available in developing countries. Such information is important for enforcing and for ensuring the quality of antihypertensive medicines. PMID:28588941

TU-H-BRC-08: Use and Validation of Flexible 3D Printed Tissue Compensators for Post-Mastectomy Radiation Therapy

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

Craft, D; Kry, S; Salehpour, M

Purpose: Patient-specific tissue equivalent compensators can be used for post-mastectomy radiation therapy (PMRT) to achieve homogenous dose distributions with single-field treatments. However, current fabrication methods are time consuming and expensive. 3D-printing technology could overcome these limitations. The purposes of this study were to [1] evaluate materials for 3D-printed compensators [2] design and print a compensator to achieve a uniform thickness to a clinical target volume (CTV), and [3] demonstrate that a single-field electron compensator plan is a clinically feasible treatment option for PMRT. Methods: Blocks were printed with three materials; print accuracy, density, Hounsfield units (HU), and percent depth dosesmore » (PDD) were evaluated. For a CT scan of an anthropomorphic phantom, we used a ray-tracing method to design a compensator that achieved uniform thickness from compensator surface to CTV. The compensator was printed with flexible tissue equivalent material whose physical and radiological properties were most similar to soft tissue. A single-field electron compensator plan was designed and compared with two standard-of-care techniques. The compensator plan was validated with thermoluminescent dosimeter (TLD) measurements. Results: We identified an appropriate material for 3D-printed compensators that had high print accuracy (99.6%) and was similar to soft tissue; density was 1.04, HU was - 45 ± 43, and PDD curves agreed with clinical curves within 3 mm. We designed and printed a compensator that conformed well to the phantom surface and created a uniform thickness to the CTV. In-house fabrication was simple and inexpensive (<$75). Compared with the two standard plans, the compensator plan resulted in overall more homogeneous dose distributions and performed similarly in terms of lung/heart doses and 90% isodose coverage of the CTV. TLD measurements agreed well with planned doses (within 5 %). Conclusions: We have demonstrated that 3D-printed compensators make single-field electron therapy a clinically feasible treatment option for PMRT.« less

Oracle estimation of parametric models under boundary constraints.

PubMed

Wong, Kin Yau; Goldberg, Yair; Fine, Jason P

2016-12-01

In many classical estimation problems, the parameter space has a boundary. In most cases, the standard asymptotic properties of the estimator do not hold when some of the underlying true parameters lie on the boundary. However, without knowledge of the true parameter values, confidence intervals constructed assuming that the parameters lie in the interior are generally over-conservative. A penalized estimation method is proposed in this article to address this issue. An adaptive lasso procedure is employed to shrink the parameters to the boundary, yielding oracle inference which adapt to whether or not the true parameters are on the boundary. When the true parameters are on the boundary, the inference is equivalent to that which would be achieved with a priori knowledge of the boundary, while if the converse is true, the inference is equivalent to that which is obtained in the interior of the parameter space. The method is demonstrated under two practical scenarios, namely the frailty survival model and linear regression with order-restricted parameters. Simulation studies and real data analyses show that the method performs well with realistic sample sizes and exhibits certain advantages over standard methods. © 2016, The International Biometric Society.

Molecular cloning of Brevundimonas diminuta for efficacy assessment of reverse osmosis devices.

PubMed

Donofrio, Robert; Saha, Ratul; Bestervelt, Lori; Bagley, Susan

2012-06-01

Brevundimonas diminuta is the test organism specified in the United States Environmental Protection Agency's (USEPA) reverse osmosis (RO) treatment device verification protocol. As non-selective growth medium is employed, enumeration of B. diminuta may be impaired due to interference by indigenous heterotrophic bacteria. Thus the microbial removal capability of the filtration system may be incorrectly assessed. As these treatment devices are used in emergency situations, the health of the public could be compromised. The objective of this study was to develop selective approaches for enumerating viable B. diminuta in test water. Two molecular approaches were investigated: expression of a kanamycin resistance gene and expression of a fluorescent protein gene. The USEPA protocol specifies a 0.3 μm cell size, so the expression of the selective markers were assessed following growth on media designed to induce this small cell diameter. The kan(R) strain was demonstrated to be equivalent to the wild type in cell dimension and survival following exposure to the test water. The kan(R) strain showed equivalent performance to the wild type in the RO protocol indicating that it is a viable alternative surrogate. By utilizing this strain, a more accurate validation of the RO system can be achieved.

Simultaneous CO concentration and temperature measurements using tunable diode laser absorption spectroscopy near 2.3 μm

NASA Astrophysics Data System (ADS)

Sane, Anup; Satija, Aman; Lucht, Robert P.; Gore, Jay P.

2014-10-01

Simultaneous measurements of carbon monoxide (CO) mole fraction and temperature using tunable diode laser absorption spectroscopy (TDLAS) near 2.3 μm are reported. The measurement method uses ro-vibrational transitions [R(27): v″ = 1 → v' = 3] and [R(6): v″ = 0 → v' = 2] in the first overtone band of CO near 2.3 μm (~4,278 cm-1). The measurements were performed in the post flame environment of fuel rich premixed ethylene-air flames with a N2 co-flow, stabilized over a water cooled McKenna burner. Non-uniformity in the temperature and CO mole fraction, along the absorption line of sight, in the mixing layer of the co-flow, was considered during data analysis. The TDLAS based temperature measurements (±80 K) were in good agreement with those obtained using N2 vibrational coherent anti-Stokes Raman scattering (±20 K), and the CO mole fraction measurements were in good agreement with the equilibrium values, for equivalence ratios lower than 1.8. A signal to noise ratio of 45 was achieved at an equivalence ratio of 1 for a CO concentration of 0.8 % at 1,854 K.

Computationally Efficient Adaptive Beamformer for Ultrasound Imaging Based on QR Decomposition.

PubMed

Park, Jongin; Wi, Seok-Min; Lee, Jin S

2016-02-01

Adaptive beamforming methods for ultrasound imaging have been studied to improve image resolution and contrast. The most common approach is the minimum variance (MV) beamformer which minimizes the power of the beamformed output while maintaining the response from the direction of interest constant. The method achieves higher resolution and better contrast than the delay-and-sum (DAS) beamformer, but it suffers from high computational cost. This cost is mainly due to the computation of the spatial covariance matrix and its inverse, which requires O(L(3)) computations, where L denotes the subarray size. In this study, we propose a computationally efficient MV beamformer based on QR decomposition. The idea behind our approach is to transform the spatial covariance matrix to be a scalar matrix σI and we subsequently obtain the apodization weights and the beamformed output without computing the matrix inverse. To do that, QR decomposition algorithm is used and also can be executed at low cost, and therefore, the computational complexity is reduced to O(L(2)). In addition, our approach is mathematically equivalent to the conventional MV beamformer, thereby showing the equivalent performances. The simulation and experimental results support the validity of our approach.

29 CFR 1915.89 - Control of hazardous energy (lockout/tags-plus).

Code of Federal Regulations, 2012 CFR

2012-07-01

... employee: (A) Sign a group tag (or a group tag equivalent), attach a personal identification device to a... group tag (or the group tag equivalent), remove the personal identification device, or perform a... safe exposure status of each authorized employee, and (b) signs a group tag (or a group tag equivalent...

29 CFR 1915.89 - Control of hazardous energy (lockout/tags-plus).

Code of Federal Regulations, 2013 CFR

2013-07-01

... employee: (A) Sign a group tag (or a group tag equivalent), attach a personal identification device to a... group tag (or the group tag equivalent), remove the personal identification device, or perform a... safe exposure status of each authorized employee, and (b) signs a group tag (or a group tag equivalent...

29 CFR 1915.89 - Control of hazardous energy (lockout/tags-plus).

Code of Federal Regulations, 2014 CFR

2014-07-01

... employee: (A) Sign a group tag (or a group tag equivalent), attach a personal identification device to a... group tag (or the group tag equivalent), remove the personal identification device, or perform a... safe exposure status of each authorized employee, and (b) signs a group tag (or a group tag equivalent...

49 CFR 178.513 - Standards for boxes of natural wood.

Code of Federal Regulations, 2010 CFR

2010-10-01

... FOR PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.513 Standards for boxes of... to be highly stressed must be made using clenched or annular ring nails or equivalent fastenings. (3) Each part of the 4C2 box must be one piece or equivalent. Parts are considered equivalent to one piece...

Characterizing hydrochemical properties of springs in Taiwan based on their geological origins.

PubMed

Jang, Cheng-Shin; Chen, Jui-Sheng; Lin, Yun-Bin; Liu, Chen-Wuing

2012-01-01

This study was performed to characterize hydrochemical properties of springs based on their geological origins in Taiwan. Stepwise discriminant analysis (DA) was used to establish a linear classification model of springs using hydrochemical parameters. Two hydrochemical datasets-ion concentrations and relative proportions of equivalents per liter of major ions-were included to perform prediction of the geological origins of springs. Analyzed results reveal that DA using relative proportions of equivalents per liter of major ions yields a 95.6% right assignation, which is superior to DA using ion concentrations. This result indicates that relative proportions of equivalents of major hydrochemical parameters in spring water are more highly associated with the geological origins than ion concentrations do. Low percentages of Na(+) equivalents are common properties of springs emerging from acid-sulfate and neutral-sulfate igneous rock. Springs emerging from metamorphic rock show low percentages of Cl( - ) equivalents and high percentages of HCO[Formula: see text] equivalents, and springs emerging from sedimentary rock exhibit high Cl( - )/SO(2-)(4) ratios.

Protograph LDPC Codes with Node Degrees at Least 3

NASA Technical Reports Server (NTRS)

Divsalar, Dariush; Jones, Christopher

2006-01-01

In this paper we present protograph codes with a small number of degree-3 nodes and one high degree node. The iterative decoding threshold for proposed rate 1/2 codes are lower, by about 0.2 dB, than the best known irregular LDPC codes with degree at least 3. The main motivation is to gain linear minimum distance to achieve low error floor. Also to construct rate-compatible protograph-based LDPC codes for fixed block length that simultaneously achieves low iterative decoding threshold and linear minimum distance. We start with a rate 1/2 protograph LDPC code with degree-3 nodes and one high degree node. Higher rate codes are obtained by connecting check nodes with degree-2 non-transmitted nodes. This is equivalent to constraint combining in the protograph. The condition where all constraints are combined corresponds to the highest rate code. This constraint must be connected to nodes of degree at least three for the graph to have linear minimum distance. Thus having node degree at least 3 for rate 1/2 guarantees linear minimum distance property to be preserved for higher rates. Through examples we show that the iterative decoding threshold as low as 0.544 dB can be achieved for small protographs with node degrees at least three. A family of low- to high-rate codes with minimum distance linearly increasing in block size and with capacity-approaching performance thresholds is presented. FPGA simulation results for a few example codes show that the proposed codes perform as predicted.

Offsetting the impacts of mining to achieve no net loss of native vegetation.

PubMed

Sonter, L J; Barrett, D J; Soares-Filho, B S

2014-08-01

Offsets are a novel conservation tool, yet using them to achieve no net loss of biodiversity is challenging. This is especially true when using conservation offsets (i.e., protected areas) because achieving no net loss requires avoiding equivalent loss. Our objective was to determine if offsetting the impacts of mining achieves no net loss of native vegetation in Brazil's largest iron mining region. We used a land-use change model to simulate deforestation by mining to 2020; developed a model to allocate conservation offsets to the landscape under 3 scenarios (baseline, no new offsets; current practice, like-for-like [by vegetation type] conservation offsetting near the impact site; and threat scenario, like-for-like conservation offsetting of highly threatened vegetation); and simulated nonmining deforestation to 2020 for each scenario to quantify avoided deforestation achieved with offsets. Mines cleared 3570 ha of native vegetation by 2020. Under a 1:4 offset ratio, mining companies would be required to conserve >14,200 ha of native vegetation, doubling the current extent of protected areas in the region. Allocating offsets under current practice avoided deforestation equivalent to 3% of that caused by mining, whereas allocating under the threat scenario avoided 9%. Current practice failed to achieve no net loss because offsets did not conserve threatened vegetation. Explicit allocation of offsets to threatened vegetation also failed because the most threatened vegetation was widely dispersed across the landscape, making conservation logistically difficult. To achieve no net loss with conservation offsets requires information on regional deforestation trajectories and the distribution of threatened vegetation. However, in some regions achieving no net loss through conservation may be impossible. In these cases, other offsetting activities, such as revegetation, will be required. © 2014 Society for Conservation Biology.

Night Vision Laboratory Static Performance Model for Thermal Viewing Systems

DTIC Science & Technology

1975-04-01

Research and Development Technical Report f ECOM-� • i’.__1’=• =•NIGHT VISION LABORATORY STATIC PERFORMANCE MODEL 1 S1=• : FOR THERMAL VIEWING...resolvable temperature Infrared imaging Minimum detectable temperature1.Detection and recognition performance Night visi,-)n Noise equivalent temperature...modulation transfer function (MTF). The noise charactcristics are specified by the noise equivalent temper- ature difference (NE AT), The next sections

Premix fuels study applicable to duct burner conditions for a variable cycle engine

NASA Technical Reports Server (NTRS)

Venkataramani, K. S.

1978-01-01

Emission levels and performance of a premixing Jet-A/air duct burner were measured at reference conditions representative of take-off and cruise for a variable cycle engine. In a parametric variation sequence of tests, data were obtained at inlet temperatures of 400, 500 and 600K at equivalence ratios varying from 0.9 to the lean stability limit. Ignition was achieved at all the reference conditions although the CO levels were very high. Significant nonuniformity across the combustor was observed for the emissions at the take-off condition. At a reference Mach number of 0.117 and an inlet temperature of 600K, corresponding to a simulated cruise condition, the NOx emission level was approximately 1 gm/kg-fuel.

Production of EUV mask blanks with low killer defects

NASA Astrophysics Data System (ADS)

Antohe, Alin O.; Kearney, Patrick; Godwin, Milton; He, Long; John Kadaksham, Arun; Goodwin, Frank; Weaver, Al; Hayes, Alan; Trigg, Steve

2014-04-01

For full commercialization, extreme ultraviolet lithography (EUVL) technology requires the availability of EUV mask blanks that are free of defects. This remains one of the main impediments to the implementation of EUV at the 22 nm node and beyond. Consensus is building that a few small defects can be mitigated during mask patterning, but defects over 100 nm (SiO2 equivalent) in size are considered potential "killer" defects or defects large enough that the mask blank would not be usable. The current defect performance of the ion beam sputter deposition (IBD) tool will be discussed and the progress achieved to date in the reduction of large size defects will be summarized, including a description of the main sources of defects and their composition.

Optimal digital dynamical decoupling for general decoherence via Walsh modulation

NASA Astrophysics Data System (ADS)

Qi, Haoyu; Dowling, Jonathan P.; Viola, Lorenza

2017-11-01

We provide a general framework for constructing digital dynamical decoupling sequences based on Walsh modulation—applicable to arbitrary qubit decoherence scenarios. By establishing equivalence between decoupling design based on Walsh functions and on concatenated projections, we identify a family of optimal Walsh sequences, which can be exponentially more efficient, in terms of the required total pulse number, for fixed cancellation order, than known digital sequences based on concatenated design. Optimal sequences for a given cancellation order are highly non-unique—their performance depending sensitively on the control path. We provide an analytic upper bound to the achievable decoupling error and show how sequences within the optimal Walsh family can substantially outperform concatenated decoupling in principle, while respecting realistic timing constraints.

Gallium arsenide quantum well-based far infrared array radiometric imager

NASA Technical Reports Server (NTRS)

Forrest, Kathrine A.; Jhabvala, Murzy D.

1991-01-01

We have built an array-based camera (FIRARI) for thermal imaging (lambda = 8 to 12 microns). FIRARI uses a square format 128 by 128 element array of aluminum gallium arsenide quantum well detectors that are indium bump bonded to a high capacity silicon multiplexer. The quantum well detectors offer good responsivity along with high response and noise uniformity, resulting in excellent thermal images without compensation for variation in pixel response. A noise equivalent temperature difference of 0.02 K at a scene temperature of 290 K was achieved with the array operating at 60 K. FIRARI demonstrated that AlGaAS quantum well detector technology can provide large format arrays with performance superior to mercury cadmium telluride at far less cost.

Thermal barrier coating on high temperature industrial gas turbine engines

NASA Technical Reports Server (NTRS)

Carlson, N.; Stoner, B. L.

1977-01-01

The thermal barrier coating used was a yttria stabilized zirconia material with a NiCrAlY undercoat, and the base engine used to establish improvements was the P&WA FT50A-4 industrial gas turbine engine. The design benefits of thermal barrier coatings include simplified cooling schemes and the use of conventional alloys in the engine hot section. Cooling flow reductions and improved heating rates achieved with thermal barrier coating result in improved performance. Economic benefits include reduced power production costs and reduced fuel consumption. Over the 30,000 hour life of the thermal barrier coated parts, fuel savings equivalent to $5 million are projected and specific power (megawatts/mass of engine airflow) improvements on the order of 13% are estimated.

Experimental parametric study of jet vortex generators for flow separation control

NASA Technical Reports Server (NTRS)

Selby, Gregory

1991-01-01

A parametric wind-tunnel study was performed with jet vortex generators to determine their effectiveness in controlling flow separation associated with low-speed turbulence flow over a two-dimensional rearward-facing ramp. Results indicate that flow-separation control can be accomplished, with the level of control achieved being a function of jet speed, jet orientation (with respect to the free-stream direction), and orifice pattern (double row of jets vs. single row). Compared to slot blowing, jet vortex generators can provide an equivalent level of flow control over a larger spanwise region (for constant jet flow area and speed). Dye flow visualization tests in a water tunnel indicated that the most effective jet vortex generator configurations produced streamwise co-rotating vortices.

Optimization of decoupling performance of underwater acoustic coating with cavities via equivalent fluid model

NASA Astrophysics Data System (ADS)

Huang, Lingzhi; Xiao, Yong; Wen, Jihong; Zhang, Hao; Wen, Xisen

2018-07-01

Acoustic coatings with periodically arranged internal cavities have been successfully applied in submarines for the purpose of decoupling water from vibration of underwater structures, and thus reducing underwater sound radiation. Previous publications on decoupling acoustic coatings with cavities are mainly focused on the case of coatings with specific shaped cavities, including cylindrical and conical cavities. To explore better decoupling performance, an optimal design of acoustic coating with complex shaped cavities is attempted in this paper. An equivalent fluid model is proposed to characterize coatings with general axisymmetrical cavities. By employing the equivalent fluid model, an analytical vibroacoustic model is further developed for the prediction of sound radiation from an infinite plate covered with an equivalent fluid layer (as a replacement of original coating) and immersed in water. Numerical examples are provided to verify the equivalent fluid model. Based on a combining use of the analytical vibroacoustic model and a differential evolution algorithm, optimal designs for acoustic coatings with cavities are conducted. Numerical results demonstrate that the decoupling performance of acoustic coating can be significantly improved by employing special axisymmetrical cavities as compared to traditional cylindrical cavities.

Experimental study on pore structure and performance of sintered porous wick

NASA Astrophysics Data System (ADS)

He, Da; Wang, Shufan; Liu, Rutie; Wang, Zhubo; Xiong, Xiang; Zou, Jianpeng

2018-02-01

Porous wicks were prepared via powder metallurgy using NH4HCO3 powders as pore-forming agent. The pore-forming agent particle size was varied to control the pore structure and equivalent pore size distribution feature of porous wick. The effect of pore-forming agent particle size on the porosity, pore structures, equivalent pore size distribution and capillary pumping performance were investigated. Results show that with the particle size of pore-forming agent decrease, the green density and the volume shrinkage of the porous wicks gradually increase and the porosity reduces slightly. There are two types of pores inside the porous wick, large-sized prefabricated pores and small-sized gap pores. With the particle size of pore-forming agent decrease, the size of the prefabricated pores becomes smaller and the distribution tends to be uniform. Gap pores and prefabricated pores inside the wick can make up different types of pore channels. The equivalent pore size of wick is closely related to the structure of pore channels. Furthermore, the equivalent pore size distribution of wick shows an obvious double-peak feature when the pore-forming agent particle size is large. With the particle size of pore-forming agent decrease, the two peaks of equivalent pore size distribution approach gradually to each other, resulting in a single-peak feature. Porous wick with single-peak feature equivalent pore size distribution possesses the better capillary pumping performances.

Experimental demonstration of distributed feedback semiconductor lasers based on reconstruction-equivalent-chirp technology.

PubMed

Li, Jingsi; Wang, Huan; Chen, Xiangfei; Yin, Zuowei; Shi, Yuechun; Lu, Yanqing; Dai, Yitang; Zhu, Hongliang

2009-03-30

In this paper we report, to the best of our knowledge, the first experimental realization of distributed feedback (DFB) semiconductor lasers based on reconstruction-equivalent-chirp (REC) technology. Lasers with different lasing wavelengths are achieved simultaneously on one chip, which shows a potential for the REC technology in combination with the photonic integrated circuits (PIC) technology to be a possible method for monolithic integration, in that its fabrication is as powerful as electron beam technology and the cost and time-consuming are almost the same as standard holographic technology.

Transversal Clifford gates on folded surface codes

DOE PAGES

Moussa, Jonathan E.

2016-10-12

Surface and color codes are two forms of topological quantum error correction in two spatial dimensions with complementary properties. Surface codes have lower-depth error detection circuits and well-developed decoders to interpret and correct errors, while color codes have transversal Clifford gates and better code efficiency in the number of physical qubits needed to achieve a given code distance. A formal equivalence exists between color codes and folded surface codes, but it does not guarantee the transferability of any of these favorable properties. However, the equivalence does imply the existence of constant-depth circuit implementations of logical Clifford gates on folded surfacemore » codes. We achieve and improve this result by constructing two families of folded surface codes with transversal Clifford gates. This construction is presented generally for qudits of any dimension. Lastly, the specific application of these codes to universal quantum computation based on qubit fusion is also discussed.« less

Clinical outcomes after the use of complete autologous oral mucosa equivalents: preliminary cases.

PubMed

Peña, Ignacio; Junquera, Luis Manuel; Llorente, Santiago; de Villalaín, Lucas; de Vicente, Juan Carlos; Llames, Sara

2012-05-01

Previously, we reported how to obtain complete autologous oral mucosa equivalents (CAOMEs) composed of an autologous plasma scaffold and fibroblasts together with immature keratinocytes able to build an oral epithelium with a structure similar to that of the oral mucosa. In this study, we present the clinical outcomes after applying our CAOMEs as grafts. Four patients who needed a CAOME to restore a defect of oral mucosa were selected. Two of the patients suffered from ankyloglossia, and the other 2 required a restoration of the keratinized gum of the alveolar rim. To assess the outcomes, the scale designed by Ewers et al. was used. Clinical and functional improvements were achieved in the patients with ankyloglossia. In cases of gum restoration, the mucosa was regenerated and a prosthetic restoration with implants was achieved. The results obtained points to the potential use of CAOME in intraoral lining. Copyright © 2012 Elsevier Inc. All rights reserved.

Dynamical equivalence, the origin of the Galactic field stellar and binary population, and the initial radius-mass relation of embedded clusters

NASA Astrophysics Data System (ADS)

Belloni, Diogo; Kroupa, Pavel; Rocha-Pinto, Helio J.; Giersz, Mirek

2018-03-01

In order to allow a better understanding of the origin of Galactic field populations, dynamical equivalence of stellar-dynamical systems has been postulated by Kroupa and Belloni et al. to allow mapping of solutions of the initial conditions of embedded clusters such that they yield, after a period of dynamical processing, the Galactic field population. Dynamically equivalent systems are defined to initially and finally have the same distribution functions of periods, mass ratios and eccentricities of binary stars. Here, we search for dynamically equivalent clusters using the MOCCA code. The simulations confirm that dynamically equivalent solutions indeed exist. The result is that the solution space is next to identical to the radius-mass relation of Marks & Kroupa, ( r_h/pc )= 0.1^{+0.07}_{-0.04} ( M_ecl/M_{⊙} )^{0.13± 0.04}. This relation is in good agreement with the oIMF. This is achieved by applying a similar procedurebserved density of molecular cloud clumps. According to the solutions, the time-scale to reach dynamical equivalence is about 0.5 Myr which is, interestingly, consistent with the lifetime of ultra-compact H II regions and the time-scale needed for gas expulsion to be active in observed very young clusters as based on their dynamical modelling.

Alternative Formats to Achieve More Efficient Energy Codes for Commercial Buildings

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

Conover, David R.; Rosenberg, Michael I.; Halverson, Mark A.

2013-01-26

This paper identifies and examines several formats or structures that could be used to create the next generation of more efficient energy codes and standards for commercial buildings. Pacific Northwest National Laboratory (PNNL) is funded by the U.S. Department of Energy’s Building Energy Codes Program (BECP) to provide technical support to the development of ANSI/ASHRAE/IES Standard 90.1. While the majority of PNNL’s ASHRAE Standard 90.1 support focuses on developing and evaluating new requirements, a portion of its work involves consideration of the format of energy standards. In its current working plan, the ASHRAE 90.1 committee has approved an energy goalmore » of 50% improvement in Standard 90.1-2013 relative to Standard 90.1-2004, and will likely be considering higher improvement targets for future versions of the standard. To cost-effectively achieve the 50% goal in manner that can gain stakeholder consensus, formats other than prescriptive must be considered. Alternative formats that include reducing the reliance on prescriptive requirements may make it easier to achieve these aggressive efficiency levels in new codes and standards. The focus on energy code and standard formats is meant to explore approaches to presenting the criteria that will foster compliance, enhance verification, and stimulate innovation while saving energy in buildings. New formats may also make it easier for building designers and owners to design and build the levels of efficiency called for in the new codes and standards. This paper examines a number of potential formats and structures, including prescriptive, performance-based (with sub-formats of performance equivalency and performance targets), capacity constraint-based, and outcome-based. The paper also discusses the pros and cons of each format from the viewpoint of code users and of code enforcers.« less

SU-G-JeP2-07: Fusion Optimization of Multi-Contrast MRI Scans for MR-Based Treatment Planning

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

Zhang, L; Yin, F; Liang, X

Purpose: To develop an image fusion method using multiple contrast MRI scans for MR-based treatment planning. Methods: T1 weighted (T1-w), T2 weighted (T2-w) and diffusion weighted images (DWI) were acquired from liver cancer patient with breath-holding. Image fade correction and deformable image registration were performed using VelocityAI (Varian Medical Systems, CA). Registered images were normalized to mean voxel intensity for each image dataset. Contrast to noise ratio (CNR) between tumor and liver was quantified. Tumor area was defined as the GTV contoured by physicians. Normal liver area with equivalent dimension was used as background. Noise was defined by the standardmore » deviation of voxel intensities in the same liver area. Linear weightings were applied to T1-w, T2-w and DWI images to generate composite image and CNR was calculated for each composite image. Optimization process were performed to achieve different clinical goals. Results: With a goal of maximizing tumor contrast, the composite image achieved a 7–12 fold increase in tumor CNR (142.8 vs. −2.3, 11.4 and 20.6 for T1-w, T2-w and DWI only, respectively), while anatomical details were largely invisible. With a weighting combination of 100%, −10% and −10%, respectively, tumor contrast was enhanced from −2.3 to −5.4, while the anatomical details were clear. With a weighting combination of 25%, 20% and 55%, balanced tumor contrast and anatomy was achieved. Conclusion: We have investigated the feasibility of performing image fusion optimization on multiple contrast MRI images. This mechanism could help utilize multiple contrast MRI scans to potentially facilitate future MR-based treatment planning.« less

Design study of a high-resolution breast-dedicated PET system built from cadmium zinc telluride detectors

PubMed Central

Peng, Hao; Levin, Craig S

2013-01-01

We studied the performance of a dual-panel positron emission tomography (PET) camera dedicated to breast cancer imaging using Monte Carlo simulation. The proposed system consists of two 4 cm thick 12 × 15 cm2 area cadmium zinc telluride (CZT) panels with adjustable separation, which can be put in close proximity to the breast and/or axillary nodes. Unique characteristics distinguishing the proposed system from previous efforts in breast-dedicated PET instrumentation are the deployment of CZT detectors with superior spatial and energy resolution, using a cross-strip electrode readout scheme to enable 3D positioning of individual photon interaction coordinates in the CZT, which includes directly measured photon depth-of-interaction (DOI), and arranging the detector slabs edge-on with respect to incoming 511 keV photons for high photon sensitivity. The simulation results show that the proposed CZT dual-panel PET system is able to achieve superior performance in terms of photon sensitivity, noise equivalent count rate, spatial resolution and lesion visualization. The proposed system is expected to achieve ~32% photon sensitivity for a point source at the center and a 4 cm panel separation. For a simplified breast phantom adjacent to heart and torso compartments, the peak noise equivalent count (NEC) rate is predicted to be ~94.2 kcts s−1 (breast volume: 720 cm3 and activity concentration: 3.7 kBq cm−3) for a ~10% energy window around 511 keV and ~8 ns coincidence time window. The system achieves 1 mm intrinsic spatial resolution anywhere between the two panels with a 4 cm panel separation if the detectors have DOI resolution less than 2 mm. For a 3 mm DOI resolution, the system exhibits excellent sphere resolution uniformity (σrms/mean) ≤ 10%) across a 4 cm width FOV. Simulation results indicate that the system exhibits superior hot sphere visualization and is expected to visualize 2 mm diameter spheres with a 5:1 activity concentration ratio within roughly 7 min imaging time. Furthermore, we observe that the degree of spatial resolution degradation along the direction orthogonal to the two panels that is typical of a limited angle tomography configuration is mitigated by having high-resolution DOI capabilities that enable more accurate positioning of oblique response lines. PMID:20400807

Research of vibration control based on current mode piezoelectric shunt damping circuit

NASA Astrophysics Data System (ADS)

Liu, Weiwei; Mao, Qibo

2017-12-01

The piezoelectric shunt damping circuit using current mode approach is imposed to control the vibration of a cantilever beam. Firstly, the simulated inductance with large values are designed for the corresponding RL series shunt circuits. Moreover, with an example of cantilever beam, the second natural frequency of the beam is targeted to control for experiment. By adjusting the values of the equivalent inductance and equivalent resistance of the shunt circuit, the optimal damping of the shunt circuit is obtained. Meanwhile, the designed piezoelectric shunt damping circuit stability is experimental verified. Experimental results show that the proposed piezoelectric shunt damping circuit based on current mode circuit has good vibration control performance. However, the control performance will be reduced if equivalent inductance and equivalent resistance values deviate from optimal values.

Effects of Fuel Distribution on Detonation Tube Performance

NASA Technical Reports Server (NTRS)

Perkins, Hugh Douglas

2002-01-01

A pulse detonation engine (PDE) uses a series of high frequency intermittent detonation tubes to generate thrust. The process of filling the detonation tube with fuel and air for each cycle may yield non-uniform mixtures. Lack of mixture uniformity is commonly ignored when calculating detonation tube thrust performance. In this study, detonation cycles featuring idealized non-uniform H2/air mixtures were analyzed using the SPARK two-dimensional Navier-Stokes CFD code with 7-step H2/air reaction mechanism. Mixture non-uniformities examined included axial equivalence ratio gradients, transverse equivalence ratio gradients, and partially fueled tubes. Three different average test section equivalence ratios (phi), stoichiometric (phi = 1.00), fuel lean (phi = 0.90), and fuel rich (phi = 1.10), were studied. All mixtures were detonable throughout the detonation tube. It was found that various mixtures representing the same test section equivalence ratio had specific impulses within 1 percent of each other, indicating that good fuel/air mixing is not a prerequisite for optimal detonation tube performance.

Water equivalency evaluation of PRESAGE® dosimeters for dosimetry of Cs-137 and Ir-192 brachytherapy sources

NASA Astrophysics Data System (ADS)

Gorjiara, Tina; Hill, Robin; Kuncic, Zdenka; Baldock, Clive

2010-11-01

A major challenge in brachytherapy dosimetry is the measurement of steep dose gradients. This can be achieved with a high spatial resolution three dimensional (3D) dosimeter. PRESAGE® is a polyurethane based dosimeter which is suitable for 3D dosimetry. Since an ideal dosimeter is radiologically water equivalent, we have investigated the relative dose response of three different PRESAGE® formulations, two with a lower chloride and bromide content than original one, for Cs-137 and Ir-192 brachytherapy sources. Doses were calculated using the EGSnrc Monte Carlo package. Our results indicate that PRESAGE® dosimeters are suitable for relative dose measurement of Cs-137 and Ir-192 brachytherapy sources and the lower halogen content PRESAGE® dosimeters are more water equivalent than the original formulation.

Experimental investigation of syngas flame stability using a multi-tube fuel injector in a high pressure combustor

NASA Astrophysics Data System (ADS)

Maldonado, Sergio Elzar

Over 92% of the coal consumed by power plants is used to generate electricity in the United States (U.S.). The U.S. has the world's largest recoverable reserves of coal, it is estimated that reserves of coal will last more than 200 years based in current production and demand levels. Integrated Gasification Combined Cycle (IGCC) power plants aim to reduce the amount of pollutants by gasifying coal and producing synthesis gas. Synthesis gas, also known as syngas, is a product of coal gasification and can be used in gas turbines for energy production. Syngas is primarily a mixture of hydrogen and carbon monoxide and is produced by gasifying a solid fuel feedstock such as coal or biomass. The objective of the thesis is to create a flame stability map by performing various experiments using high-content hydrogen fuels with varying compositions of hydrogen representing different coal feedstocks. The experiments shown in this thesis were performed using the High-Pressure Combustion facility in the Center for Space Exploration Technology Research (CSETR) at the University of Texas at El Paso (UTEP). The combustor was fitted with a novel Multi-Tube fuel Injector (MTI) designed to improve flame stability. This thesis presents the results of testing of syngas fuels with compositions of 20, 30, and 40% hydrogen concentrations in mixtures with carbon monoxide. Tests were completed for lean conditions ranging from equivalence ratios between 0.6 and 0.9. The experimental results showed that at an equivalence ratio of 0.6, a stable flame was not achieved for any of the fuel mixtures tested. It was also observed that the stability region of the syngas flame increased as equivalence ratio and the hydrogen concentration in syngas fuel increases with the 40% hydrogen-carbon monoxide mixture demonstrating the greatest stability region. Design improvements to the MTI are also discussed as part of the future work on this topic.

Catalytic EGR-Loop Reforming for High Efficiency in a Stoichiometric SI Engine through TCR and Dilution Limit Extension. 1. Catalyst Performance and Fuel Effects

DOE PAGES

Chang, Yan; Szybist, James P.; Pihl, Josh A.; ...

2017-12-19

The use of fuel reformate from catalytic processes is known to have beneficial effects on the spark-ignited (SI) combustion process through enhanced dilution tolerance and decreased combustion duration, but in many cases reformate generation can incur a significant fuel penalty. Here, in this two-part investigation, we demonstrate that efficient catalytic fuel reforming can result in improved brake engine efficiency while maintaining stoichiometric exhaust under the right conditions. In part one of this investigation, we used a combination of thermodynamic equilibrium calculations and experimental fuel catalytic reforming measurements on an engine to characterize the best possible reforming performance and energetics overmore » a range of equivalence ratios and O 2 concentrations. Ideally, one might expect the highest levels of thermochemical recuperation for the highest catalyst equivalence ratios. However, reforming under these conditions is highly endothermic, and the available enthalpy for reforming is constrained. Thus for relatively high equivalence ratios, more methane and less H 2 and CO are produced. Our experiments revealed that this suppression of H 2 and CO could be countered by adding small amounts of O 2, yielding as much as 15 vol % H 2 at the catalyst outlet for 4 < Φ catalyst < 7 under quasi-steady-state conditions. Under these conditions the H 2 and CO yields were highest and there was significant water consumption, confirming the presence of steam reforming reactions. Analyses of the experimental catalyst measurements indicated the possibility of both endothermic and exothermic reaction stages and global reaction rates sufficient to enable the utilization of higher space velocities than those employed in our experiments. Finally, in a companion paper detailing part two of this investigation, we present results for the engine dilution tolerance and brake engine efficiency impacts of the reforming levels achieved.« less

Catalytic EGR-Loop Reforming for High Efficiency in a Stoichiometric SI Engine through TCR and Dilution Limit Extension. 1. Catalyst Performance and Fuel Effects

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

Chang, Yan; Szybist, James P.; Pihl, Josh A.

The use of fuel reformate from catalytic processes is known to have beneficial effects on the spark-ignited (SI) combustion process through enhanced dilution tolerance and decreased combustion duration, but in many cases reformate generation can incur a significant fuel penalty. Here, in this two-part investigation, we demonstrate that efficient catalytic fuel reforming can result in improved brake engine efficiency while maintaining stoichiometric exhaust under the right conditions. In part one of this investigation, we used a combination of thermodynamic equilibrium calculations and experimental fuel catalytic reforming measurements on an engine to characterize the best possible reforming performance and energetics overmore » a range of equivalence ratios and O 2 concentrations. Ideally, one might expect the highest levels of thermochemical recuperation for the highest catalyst equivalence ratios. However, reforming under these conditions is highly endothermic, and the available enthalpy for reforming is constrained. Thus for relatively high equivalence ratios, more methane and less H 2 and CO are produced. Our experiments revealed that this suppression of H 2 and CO could be countered by adding small amounts of O 2, yielding as much as 15 vol % H 2 at the catalyst outlet for 4 < Φ catalyst < 7 under quasi-steady-state conditions. Under these conditions the H 2 and CO yields were highest and there was significant water consumption, confirming the presence of steam reforming reactions. Analyses of the experimental catalyst measurements indicated the possibility of both endothermic and exothermic reaction stages and global reaction rates sufficient to enable the utilization of higher space velocities than those employed in our experiments. Finally, in a companion paper detailing part two of this investigation, we present results for the engine dilution tolerance and brake engine efficiency impacts of the reforming levels achieved.« less

Advanced Life Support Equivalent System Mass Guidelines Document

NASA Technical Reports Server (NTRS)

Levri, Julie; Fisher, John W.; Jones, Harry W.; Drysdale, Alan E.; Ewert, Michael K.; Hanford, Anthony J.; Hogan, John A.; Joshi, Jitendri, A.; Vaccari, David A.

2003-01-01

This document is a viewgraph presentation which provides guidelines for performing an Equivalent System Mass (ESM) evaluation for trade study purposes. The document: 1) Defines ESM; 2) Explains how to calculate ESM; 3) Discusses interpretation of ESM results. The document is designed to provide detailed instructive material for researchers who are performing ESM evaluations for the first time.

5 CFR 9901.345 - Accelerated Compensation for Developmental Positions (ACDP).

Code of Federal Regulations, 2011 CFR

2011-01-01

... applicable control point, unless the criteria for exceeding the control point are met. (f) To qualify for an ACDP, an employee must have a rating of record of Level 3 (or equivalent non-NSPS rating of record) or... performing at the equivalent of Level 3 or higher. This performance assessment does not constitute a rating...

5 CFR 9901.345 - Accelerated Compensation for Developmental Positions (ACDP).

Code of Federal Regulations, 2010 CFR

2010-01-01

... applicable control point, unless the criteria for exceeding the control point are met. (f) To qualify for an ACDP, an employee must have a rating of record of Level 3 (or equivalent non-NSPS rating of record) or... performing at the equivalent of Level 3 or higher. This performance assessment does not constitute a rating...

Effects of equivalent series resistance on the noise mitigation performance of piezoelectric shunt damping

NASA Astrophysics Data System (ADS)

Lai, Szu Cheng; Sharifzadeh Mirshekarloo, Meysam; Yao, Kui

2017-05-01

Piezoelectric shunt damping (PSD) utilizes an electrically-shunted piezoelectric damper attached on a panel structure to suppress the transmission of acoustic noise. The paper develops an understanding on the effects of equivalent series resistance (ESR) of the piezoelectric damper in a PSD system on noise mitigation performance, and demonstrates that an increased ESR leads to a significant rise in the noise transmissibility due to reduction in the system’s mechanical damping. It is further demonstrated with experimental results that ESR effects can be compensated in the shunt circuit to significantly improve the noise mitigation performance. A theoretical electrical equivalent model of the PSD incorporating the ESR is established for quantitative analysis of ESR effects on noise mitigation.

Comparison of a Stimulus Equivalence Protocol and Traditional Lecture for Teaching Single-Subject Designs

ERIC Educational Resources Information Center

Lovett, Sadie; Rehfeldt, Ruth Anne; Garcia, Yors; Dunning, Johnna

2011-01-01

This study compared the effects of a computer-based stimulus equivalence protocol to a traditional lecture format in teaching single-subject experimental design concepts to undergraduate students. Participants were assigned to either an equivalence or a lecture group, and performance on a paper-and-pencil test that targeted relations among the…

49 CFR 178.513 - Standards for boxes of natural wood.

Code of Federal Regulations, 2011 CFR

2011-10-01

... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.513 Standards for boxes of natural wood... stressed must be made using clenched or annular ring nails or equivalent fastenings. (3) Each part of the 4C2 box must be one piece or equivalent. Parts are considered equivalent to one piece when one of the...

49 CFR 178.513 - Standards for boxes of natural wood.

Code of Federal Regulations, 2013 CFR

2013-10-01

... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.513 Standards for boxes of natural wood... stressed must be made using clenched or annular ring nails or equivalent fastenings. (3) Each part of the 4C2 box must be one piece or equivalent. Parts are considered equivalent to one piece when one of the...

Mechanistic equivalent circuit modelling of a commercial polymer electrolyte membrane fuel cell

NASA Astrophysics Data System (ADS)

Giner-Sanz, J. J.; Ortega, E. M.; Pérez-Herranz, V.

2018-03-01

Electrochemical impedance spectroscopy (EIS) has been widely used in the fuel cell field since it allows deconvolving the different physic-chemical processes that affect the fuel cell performance. Typically, EIS spectra are modelled using electric equivalent circuits. In this work, EIS spectra of an individual cell of a commercial PEM fuel cell stack were obtained experimentally. The goal was to obtain a mechanistic electric equivalent circuit in order to model the experimental EIS spectra. A mechanistic electric equivalent circuit is a semiempirical modelling technique which is based on obtaining an equivalent circuit that does not only correctly fit the experimental spectra, but which elements have a mechanistic physical meaning. In order to obtain the aforementioned electric equivalent circuit, 12 different models with defined physical meanings were proposed. These equivalent circuits were fitted to the obtained EIS spectra. A 2 step selection process was performed. In the first step, a group of 4 circuits were preselected out of the initial list of 12, based on general fitting indicators as the determination coefficient and the fitted parameter uncertainty. In the second step, one of the 4 preselected circuits was selected on account of the consistency of the fitted parameter values with the physical meaning of each parameter.

A polygonal double-layer coil design for high-efficiency wireless power transfer

NASA Astrophysics Data System (ADS)

Mao, Shitong; Wang, Hao; Mao, Zhi-Hong; Sun, Mingui

2018-05-01

In this work, we present a novel coil structure for the design of Wireless Power Transfer (WPT) systems via magnetic resonant coupling. The new coil consists of two layers of flat polygonal windings in square, pentagonal and hexagonal shapes. The double-layer coil can be conveniently fabricated using the print circuit broad (PCB) technology. In our design, we include an angle between the two layers which can be adjusted to change the area of inter-layer overlap. This unique structure is thoroughly investigated with respect to the quality factor Q and the power transfer efficiency (PTE) using the finite element method (FEM). An equivalent circuit is derived and used to explain the properties of the angularly shifted double-layer coil theoretically. Comparative experiments are conducted from which the performance of the new coil is evaluated quantitatively. Our results have shown that an increased shift angle improves the Q-factor, and the optimal PTE is achieved when the angle reaches the maximum. When compared to the pentagonal and hexagonal coils, the square coil achieves the highest PTE due to its lowest parasitic capacitive effects. In summary, our new coil design improves the performance of WPT systems and allows a formal design procedure for optimization in a given application.

Evaluation of water-mimicking solid phantom materials for use in HDR and LDR brachytherapy dosimetry

NASA Astrophysics Data System (ADS)

Schoenfeld, Andreas A.; Thieben, Maike; Harder, Dietrich; Poppe, Björn; Chofor, Ndimofor

2017-12-01

In modern HDR or LDR brachytherapy with photon emitters, fast checks of the dose profiles generated in water or a water-equivalent phantom have to be available in the interest of patient safety. However, the commercially available brachytherapy photon sources cover a wide range of photon emission spectra, and the range of the in-phantom photon spectrum is further widened by Compton scattering, so that the achievement of water-mimicking properties of such phantoms involves high requirements on their atomic composition. In order to classify the degree of water equivalence of the numerous commercially available solid water-mimicking phantom materials and the energy ranges of their applicability, the radial profiles of the absorbed dose to water, D w, have been calculated using Monte Carlo simulations in these materials and in water phantoms of the same dimensions. This study includes the HDR therapy sources Nucletron Flexisource Co-60 HDR (60Co), Eckert und Ziegler BEBIG GmbH CSM-11 (137Cs), Implant Sciences Corporation HDR Yb-169 Source 4140 (169Yb) as well as the LDR therapy sources IsoRay Inc. Proxcelan CS-1 (131Cs), IsoAid Advantage I-125 IAI-125A (125I), and IsoAid Advantage Pd-103 IAPd-103A (103Pd). Thereby our previous comparison between phantom materials and water surrounding a Varian GammaMed Plus HDR therapy 192Ir source (Schoenfeld et al 2015) has been complemented. Simulations were performed in cylindrical phantoms consisting of either water or the materials RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, Plastic Water LR, Original Plastic Water (2015), Plastic Water (1995), Blue Water, polyethylene, polystyrene and PMMA. While for 192Ir, 137Cs and 60Co most phantom materials can be regarded as water equivalent, for 169Yb the materials Plastic Water LR, Plastic Water DT and RW1 appear as water equivalent. For the low-energy sources 106Pd, 131Cs and 125I, only Plastic Water LR can be classified as water equivalent.

Evaluation of water-mimicking solid phantom materials for use in HDR and LDR brachytherapy dosimetry.

PubMed

Schoenfeld, Andreas A; Thieben, Maike; Harder, Dietrich; Poppe, Björn; Chofor, Ndimofor

2017-11-21

In modern HDR or LDR brachytherapy with photon emitters, fast checks of the dose profiles generated in water or a water-equivalent phantom have to be available in the interest of patient safety. However, the commercially available brachytherapy photon sources cover a wide range of photon emission spectra, and the range of the in-phantom photon spectrum is further widened by Compton scattering, so that the achievement of water-mimicking properties of such phantoms involves high requirements on their atomic composition. In order to classify the degree of water equivalence of the numerous commercially available solid water-mimicking phantom materials and the energy ranges of their applicability, the radial profiles of the absorbed dose to water, D w , have been calculated using Monte Carlo simulations in these materials and in water phantoms of the same dimensions. This study includes the HDR therapy sources Nucletron Flexisource Co-60 HDR ( 60 Co), Eckert und Ziegler BEBIG GmbH CSM-11 ( 137 Cs), Implant Sciences Corporation HDR Yb-169 Source 4140 ( 169 Yb) as well as the LDR therapy sources IsoRay Inc. Proxcelan CS-1 ( 131 Cs), IsoAid Advantage I-125 IAI-125A ( 125 I), and IsoAid Advantage Pd-103 IAPd-103A ( 103 Pd). Thereby our previous comparison between phantom materials and water surrounding a Varian GammaMed Plus HDR therapy 192 Ir source (Schoenfeld et al 2015) has been complemented. Simulations were performed in cylindrical phantoms consisting of either water or the materials RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, Plastic Water LR, Original Plastic Water (2015), Plastic Water (1995), Blue Water, polyethylene, polystyrene and PMMA. While for 192 Ir, 137 Cs and 60 Co most phantom materials can be regarded as water equivalent, for 169 Yb the materials Plastic Water LR, Plastic Water DT and RW1 appear as water equivalent. For the low-energy sources 106 Pd, 131 Cs and 125 I, only Plastic Water LR can be classified as water equivalent.

Surface Features Parameterization and Equivalent Roughness Height Estimation of a Real Subglacial Conduit in the Arctic

NASA Astrophysics Data System (ADS)

Chen, Y.; Liu, X.; Mankoff, K. D.; Gulley, J. D.

2016-12-01

The surfaces of subglacial conduits are very complex, coupling multi-scale roughness, large sinuosity, and cross-sectional variations together. Those features significantly affect the friction law and drainage efficiency inside the conduit by altering velocity and pressure distributions, thus posing considerable influences on the dynamic development of the conduit. Parameterizing the above surface features is a first step towards understanding their hydraulic influences. A Matlab package is developed to extract the roughness field, the conduit centerline, and associated area and curvature data from the conduit surface, acquired from 3D scanning. By using those data, the characteristic vertical and horizontal roughness scales are then estimated based on the structure functions. The centerline sinuosities, defined through three concepts, i.e., the traditional definition of a fluvial river, entropy-based sinuosity, and curvature-based sinuosity, are also calculated and compared. The cross-sectional area and equivalent circular diameter along the centerline are also calculated. Among those features, the roughness is especially important due to its pivotal role in determining the wall friction, and thus an estimation of the equivalent roughness height is of great importance. To achieve such a goal, the original conduit is firstly simplified into a straight smooth pipe with the same volume and centerline length, and the roughness field obtained above is then reconstructed into the simplified pipe. An OpenFOAM-based Large-eddy-simulation (LES) is then performed based on the reconstructed pipe. Considering that the Reynolds number is of the order 106, and the relative roughness is larger than 5% for 60% of the conduit, we test the validity of the resistance law for completely rough pipe. The friction factor is calculated based on the pressure drop and mean velocity in the simulation. Working together, the equivalent roughness height can be calculated. However, whether the assumption is applicable for the current case, i.e., high relative roughness, is a question. Two other roughness heights, i.e., the vertical roughness scale based on structure functions and viscous sublayer thickness determined from the wall boundary layer are also calculated and compared with the equivalent roughness height.

Using the Lewis Acid Me3 Si-F-Al(ORF )3 To Prepare Phosphino-Phosphonium Cations with the Least-Coordinating Anion [(RF O)3 Al-F-Al(ORF )3 ].

PubMed

Possart, Josephine; Martens, Arthur; Schleep, Mario; Ripp, Alexander; Scherer, Harald; Kratzert, Daniel; Krossing, Ingo

2017-09-07

By reaction of two equivalents of Me 3 Si-F-Al(OR F ) 3 1 with an equimolar amount of PPh 2 Cl, the salt [Ph 2 P-PPh 2 Cl] + [(R F O) 3 Al-F-Al(OR F ) 3 ] - 2 is prepared smoothly in 91 % yield (NMR, XRD). The synthesis of [Ph 2 P-PPh 3 ] + [(R F O) 3 Al-F-Al(OR F ) 3 ] - 3 is best achieved by a two-step reaction: first, two equivalents of 1 react with one PPh 3 to give [Me 3 Si-PPh 3 ] + [(R F O) 3 Al-F-Al(OR F ) 3 ] - 4 (NMR, XRD), which, upon reaction with PPh 2 Cl, yields pure 3 and Me 3 SiCl (NMR, XRD). Typically, a stoichiometry of two equivalents of 1 with respect to one equivalent of the chloride donor should be used. Otherwise, the residual strong Lewis acidity of the [(R F O) 3 Al-F-Al(OR F ) 3 ] - anion in the presence of the [F-Al(OR F ) 3 ] - anion-that forms with less than two equivalents of 1-leads to further chloride exchange reactions that complicate work-up. This route presents the easiest way to introduce the least-coordinating [(R F O) 3 Al-F-Al(OR F ) 3 ] - anion into a system. We expect a wide use of this route in all areas, in which chloride-bond heterolysis in combination with very weakly coordinating anions is desirable. Additionally, we performed calculations on the bond dissociation mechanisms of [R 2 P-PMe 3 ] + and the isoelectronic Me 2 P-SiMe 3 and Me 2 Si-PMe 3 in dependence of the solvent permittivity. These calculations show, especially for the neutral reference compounds, a heavy influence of the solvent on the dissociation mechanism, which is why we suggest investigating these properties in solution instead of gas phase. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

40 CFR Table E-1 to Subpart E of... - Summary of Test Requirements for Reference and Class I Equivalent Methods for PM2.5 and PM10-2.5

Code of Federal Regulations, 2010 CFR

2010-07-01

... Reference and Class I Equivalent Methods for PM2.5 and PM10-2.5 E Table E-1 to Subpart E of Part 53... MONITORING REFERENCE AND EQUIVALENT METHODS Procedures for Testing Physical (Design) and Performance Characteristics of Reference Methods and Class I and Class II Equivalent Methods for PM2.5 or PM10â2.5 Pt. 53...

RISK EQUIVALENT SEASONAL WASTE LOAD ALLOCATION

EPA Science Inventory

Seasonal wastewater discharge programs employ different effluent standards during different times of the year to take advantage of the variation in a receiving water's susceptibility to adverse impacts. These programs should try to achieve the maximum economic benefits possible w...

An integration of external information for foreign stallions into the Belgian genetic evaluation for jumping horses.

PubMed

Vandenplas, J; Janssens, S; Buys, N; Gengler, N

2013-06-01

The aim of this study was to test the integration of external information, i.e. foreign estimated breeding values (EBV) and the associated reliabilities (REL), for stallions into the Belgian genetic evaluation for jumping horses. The Belgian model is a bivariate repeatability Best Linear Unbiased Prediction animal model only based on Belgian performances, while Belgian breeders import horses from neighbouring countries. Hence, use of external information is needed as prior to achieve more accurate EBV. Pedigree and performance data contained 101382 horses and 712212 performances, respectively. After conversion to the Belgian trait, external information of 98 French and 67 Dutch stallions was integrated into the Belgian evaluation. Resulting Belgian rankings of the foreign stallions were more similar to foreign rankings according to the increase of the rank correlations of at least 12%. REL of their EBV were improved of at least 2% on average. External information was partially to totally equivalent to 4 years of contemporary horses' performances or to all the stallions' own performances. All these results showed the interest to integrate external information into the Belgian evaluation. © 2012 Blackwell Verlag GmbH.

Automated recognition of bird song elements from continuous recordings using dynamic time warping and hidden Markov models: a comparative study.

PubMed

Kogan, J A; Margoliash, D

1998-04-01

The performance of two techniques is compared for automated recognition of bird song units from continuous recordings. The advantages and limitations of dynamic time warping (DTW) and hidden Markov models (HMMs) are evaluated on a large database of male songs of zebra finches (Taeniopygia guttata) and indigo buntings (Passerina cyanea), which have different types of vocalizations and have been recorded under different laboratory conditions. Depending on the quality of recordings and complexity of song, the DTW-based technique gives excellent to satisfactory performance. Under challenging conditions such as noisy recordings or presence of confusing short-duration calls, good performance of the DTW-based technique requires careful selection of templates that may demand expert knowledge. Because HMMs are trained, equivalent or even better performance of HMMs can be achieved based only on segmentation and labeling of constituent vocalizations, albeit with many more training examples than DTW templates. One weakness in HMM performance is the misclassification of short-duration vocalizations or song units with more variable structure (e.g., some calls, and syllables of plastic songs). To address these and other limitations, new approaches for analyzing bird vocalizations are discussed.

Wavefront-Guided Scleral Lens Correction in Keratoconus

PubMed Central

Marsack, Jason D.; Ravikumar, Ayeswarya; Nguyen, Chi; Ticak, Anita; Koenig, Darren E.; Elswick, James D.; Applegate, Raymond A.

2014-01-01

Purpose To examine the performance of state-of-the-art wavefront-guided scleral contact lenses (wfgSCLs) on a sample of keratoconic eyes, with emphasis on performance quantified with visual quality metrics; and to provide a detailed discussion of the process used to design, manufacture and evaluate wfgSCLs. Methods Fourteen eyes of 7 subjects with keratoconus were enrolled and a wfgSCL was designed for each eye. High-contrast visual acuity and visual quality metrics were used to assess the on-eye performance of the lenses. Results The wfgSCL provided statistically lower levels of both lower-order RMS (p < 0.001) and higher-order RMS (p < 0.02) than an intermediate spherical equivalent scleral contact lens. The wfgSCL provided lower levels of lower-order RMS than a normal group of well-corrected observers (p < < 0.001). However, the wfgSCL does not provide less higher-order RMS than the normal group (p = 0.41). Of the 14 eyes studied, 10 successfully reached the exit criteria, achieving residual higher-order root mean square wavefront error (HORMS) less than or within 1 SD of the levels experienced by normal, age-matched subjects. In addition, measures of visual image quality (logVSX, logNS and logLIB) for the 10 eyes were well distributed within the range of values seen in normal eyes. However, visual performance as measured by high contrast acuity did not reach normal, age-matched levels, which is in agreement with prior results associated with the acute application of wavefront correction to KC eyes. Conclusions Wavefront-guided scleral contact lenses are capable of optically compensating for the deleterious effects of higher-order aberration concomitant with the disease, and can provide visual image quality equivalent to that seen in normal eyes. Longer duration studies are needed to assess whether the visual system of the highly aberrated eye wearing a wfgSCL is capable of producing visual performance levels typical of the normal population. PMID:24830371

NEMA NU 2-2012 performance studies for the SiPM-based ToF-PET component of the GE SIGNA PET/MR system.

PubMed

Grant, Alexander M; Deller, Timothy W; Khalighi, Mohammad Mehdi; Maramraju, Sri Harsha; Delso, Gaspar; Levin, Craig S

2016-05-01

The GE SIGNA PET/MR is a new whole body integrated time-of-flight (ToF)-PET/MR scanner from GE Healthcare. The system is capable of simultaneous PET and MR image acquisition with sub-400 ps coincidence time resolution. Simultaneous PET/MR holds great potential as a method of interrogating molecular, functional, and anatomical parameters in clinical disease in one study. Despite the complementary imaging capabilities of PET and MRI, their respective hardware tends to be incompatible due to mutual interference. In this work, the GE SIGNA PET/MR is evaluated in terms of PET performance and the potential effects of interference from MRI operation. The NEMA NU 2-2012 protocol was followed to measure PET performance parameters including spatial resolution, noise equivalent count rate, sensitivity, accuracy, and image quality. Each of these tests was performed both with the MR subsystem idle and with continuous MR pulsing for the duration of the PET data acquisition. Most measurements were repeated at three separate test sites where the system is installed. The scanner has achieved an average of 4.4, 4.1, and 5.3 mm full width at half maximum radial, tangential, and axial spatial resolutions, respectively, at 1 cm from the transaxial FOV center. The peak noise equivalent count rate (NECR) of 218 kcps and a scatter fraction of 43.6% are reached at an activity concentration of 17.8 kBq/ml. Sensitivity at the center position is 23.3 cps/kBq. The maximum relative slice count rate error below peak NECR was 3.3%, and the residual error from attenuation and scatter corrections was 3.6%. Continuous MR pulsing had either no effect or a minor effect on each measurement. Performance measurements of the ToF-PET whole body GE SIGNA PET/MR system indicate that it is a promising new simultaneous imaging platform.

Teaching Equivalence Relations to Individuals with Minimal Verbal Repertoires: Are Visual and Auditory-Visual Discriminations Predictive of Stimulus Equivalence?

ERIC Educational Resources Information Center

Vause, Tricia; Martin, Garry L.; Yu, C.T.; Marion, Carole; Sakko, Gina

2005-01-01

The relationship between language, performance on the Assessment of Basic Learning Abilities (ABLA) test, and stimulus equivalence was examined. Five participants with minimal verbal repertoires were studied; 3 who passed up to ABLA Level 4, a visual quasi-identity discrimination and 2 who passed ABLA Level 6, an auditory-visual nonidentity…

The Equivalence Principle Experiment for Spin-Polarized Bodies

NASA Astrophysics Data System (ADS)

Hsieh, Chang-Huain; Jen, Pin-Yun; Ko, Kai-Li; Li, Keh-Yann; Ni, Wei-Tou; Pan, Sheau-Shi; Shih, Yung-Hui; Tyan, Rong-Jung

We perform an equivalence principle experiment for a magnetically shielded spin-polarized body of Dy6Fe23. We use a single-pan mass comparator to compare the spin-polarized body with an unpolarized group of masses. The equivalence of spin-up and spin-down positions is good to (1.1 ±7.8)×10-9 in earth gravitational field.

Compilation of Pilot Cognitive Ability Norms

DTIC Science & Technology

2011-12-01

2.1.1 Change in Performance Method. The first method is a pretest , posttest paradigm. It is the most reliable but requires prior, premorbid...elements of the person’s own performance to make conclusions regarding cognitive change. A common approach uses the effects of aging on various types of...Percentile Equivalence for IQ Scores on the MAB-II ............................................... 7 4 Percentile Equivalence for Verbal Subtest

Neutron dose measurements of Varian and Elekta linacs by TLD600 and TLD700 dosimeters and comparison with MCNP calculations

PubMed Central

Nedaie, Hassan Ali; Darestani, Hoda; Banaee, Nooshin; Shagholi, Negin; Mohammadi, Kheirollah; Shahvar, Arjang; Bayat, Esmaeel

2014-01-01

High-energy linacs produce secondary particles such as neutrons (photoneutron production). The neutrons have the important role during treatment with high energy photons in terms of protection and dose escalation. In this work, neutron dose equivalents of 18 MV Varian and Elekta accelerators are measured by thermoluminescent dosimeter (TLD) 600 and TLD700 detectors and compared with the Monte Carlo calculations. For neutron and photon dose discrimination, first TLDs were calibrated separately by gamma and neutron doses. Gamma calibration was carried out in two procedures; by standard 60Co source and by 18 MV linac photon beam. For neutron calibration by 241Am-Be source, irradiations were performed in several different time intervals. The Varian and Elekta linac heads and the phantom were simulated by the MCNPX code (v. 2.5). Neutron dose equivalent was calculated in the central axis, on the phantom surface and depths of 1, 2, 3.3, 4, 5, and 6 cm. The maximum photoneutron dose equivalents which calculated by the MCNPX code were 7.06 and 2.37 mSv.Gy-1 for Varian and Elekta accelerators, respectively, in comparison with 50 and 44 mSv.Gy-1 achieved by TLDs. All the results showed more photoneutron production in Varian accelerator compared to Elekta. According to the results, it seems that TLD600 and TLD700 pairs are not suitable dosimeters for neutron dosimetry inside the linac field due to high photon flux, while MCNPX code is an appropriate alternative for studying photoneutron production. PMID:24600167

Neutron dose measurements of Varian and Elekta linacs by TLD600 and TLD700 dosimeters and comparison with MCNP calculations.

PubMed

Nedaie, Hassan Ali; Darestani, Hoda; Banaee, Nooshin; Shagholi, Negin; Mohammadi, Kheirollah; Shahvar, Arjang; Bayat, Esmaeel

2014-01-01

High-energy linacs produce secondary particles such as neutrons (photoneutron production). The neutrons have the important role during treatment with high energy photons in terms of protection and dose escalation. In this work, neutron dose equivalents of 18 MV Varian and Elekta accelerators are measured by thermoluminescent dosimeter (TLD) 600 and TLD700 detectors and compared with the Monte Carlo calculations. For neutron and photon dose discrimination, first TLDs were calibrated separately by gamma and neutron doses. Gamma calibration was carried out in two procedures; by standard 60Co source and by 18 MV linac photon beam. For neutron calibration by (241)Am-Be source, irradiations were performed in several different time intervals. The Varian and Elekta linac heads and the phantom were simulated by the MCNPX code (v. 2.5). Neutron dose equivalent was calculated in the central axis, on the phantom surface and depths of 1, 2, 3.3, 4, 5, and 6 cm. The maximum photoneutron dose equivalents which calculated by the MCNPX code were 7.06 and 2.37 mSv.Gy(-1) for Varian and Elekta accelerators, respectively, in comparison with 50 and 44 mSv.Gy(-1) achieved by TLDs. All the results showed more photoneutron production in Varian accelerator compared to Elekta. According to the results, it seems that TLD600 and TLD700 pairs are not suitable dosimeters for neutron dosimetry inside the linac field due to high photon flux, while MCNPX code is an appropriate alternative for studying photoneutron production.

Simulation Evaluation of Synthetic Vision as an Enabling Technology for Equivalent Visual Operations

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.

2008-01-01

Enhanced Vision (EV) and synthetic vision (SV) systems may serve as enabling technologies to meet the challenges of the Next Generation Air Transportation System (NextGen) Equivalent Visual Operations (EVO) concept ? that is, the ability to achieve or even improve on the safety of Visual Flight Rules (VFR) operations, maintain the operational tempos of VFR, and even, perhaps, retain VFR procedures independent of actual weather and visibility conditions. One significant challenge lies in the definition of required equipage on the aircraft and on the airport to enable the EVO concept objective. A piloted simulation experiment was conducted to evaluate the effects of the presence or absence of Synthetic Vision, the location of this information during an instrument approach (i.e., on a Head-Up or Head-Down Primary Flight Display), and the type of airport lighting information on landing minima. The quantitative data from this experiment were analyzed to begin the definition of performance-based criteria for all-weather approach and landing operations. Objective results from the present study showed that better approach performance was attainable with the head-up display (HUD) compared to the head-down display (HDD). A slight performance improvement in HDD performance was shown when SV was added, as the pilots descended below 200 ft to a 100 ft decision altitude, but this performance was not tested for statistical significance (nor was it expected to be statistically significant). The touchdown data showed that regardless of the display concept flown (SV HUD, Baseline HUD, SV HDD, Baseline HDD) a majority of the runs were within the performance-based defined approach and landing criteria in all the visibility levels, approach lighting systems, and decision altitudes tested. For this visual flight maneuver, RVR appeared to be the most significant influence in touchdown performance. The approach lighting system clearly impacted the pilot's ability to descend to 100 ft height above touchdown based on existing Federal Aviation Regulation (FAR) 91.175 using a 200 ft decision height, but did not appear to influence touchdown performance or approach path maintenance

A novel concept for CT with fixed anodes (FACT): Medical imaging based on the feasibility of thermal load capacity.

PubMed

Kellermeier, Markus; Bert, Christoph; Müller, Reinhold G

2015-07-01

Focussing primarily on thermal load capacity, we describe the performance of a novel fixed anode CT (FACT) compared with a 100 kW reference CT. Being a fixed system, FACT has no focal spot blurring of the X-ray source during projection. Monte Carlo and finite element methods were used to determine the fluence proportional to thermal capacity. Studies of repeated short-time exposures showed that FACT could operate in pulsed mode for an unlimited period. A virtual model for FACT was constructed to analyse various temporal sequences for the X-ray source ring, representing a circular array of 1160 fixed anodes in the gantry. Assuming similar detector properties at a very small integration time, image quality was investigated using an image reconstruction library. Our model showed that approximately 60 gantry rounds per second, i.e. 60 sequential targetings of the 1160 anodes per second, were required to achieve a performance level equivalent to that of the reference CT (relative performance, RP = 1) at equivalent image quality. The optimal projection duration in each direction was about 10 μs. With a beam pause of 1 μs between projections, 78.4 gantry rounds per second with consecutive source activity were thermally possible at a given thermal focal spot. The settings allowed for a 1.3-fold (RP = 1.3) shorter scan time than conventional CT while maintaining radiation exposure and image quality. Based on the high number of rounds, FACT supports a high image frame rate at low doses, which would be beneficial in a wide range of diagnostic and technical applications. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Liquid Oxygen/Liquid Methane Test Summary of the RS-18 Lunar Ascent Engine at Simulated Altitude Conditions at NASA White Sands Test Facility

NASA Technical Reports Server (NTRS)

Melcher, John C., IV; Allred, Jennifer K.

2009-01-01

Tests were conducted with the RS18 rocket engine using liquid oxygen (LO2) and liquid methane (LCH4) propellants under simulated altitude conditions at NASA Johnson Space Center White Sands Test Facility (WSTF). This project is part of NASA s Propulsion and Cryogenics Advanced Development (PCAD) project. "Green" propellants, such as LO2/LCH4, offer savings in both performance and safety over equivalently sized hypergolic propellant systems in spacecraft applications such as ascent engines or service module engines. Altitude simulation was achieved using the WSTF Large Altitude Simulation System, which provided altitude conditions equivalent up to approx.120,000 ft (approx.37 km). For specific impulse calculations, engine thrust and propellant mass flow rates were measured. Propellant flow rate was measured using a coriolis-style mass-flow meter and compared with a serial turbine-style flow meter. Results showed a significant performance measurement difference during ignition startup. LO2 flow ranged from 5.9-9.5 lbm/sec (2.7-4.3 kg/sec), and LCH4 flow varied from 3.0-4.4 lbm/sec (1.4-2.0 kg/sec) during the RS-18 hot-fire test series. Thrust was measured using three load cells in parallel. Ignition was demonstrated using a gaseous oxygen/methane spark torch igniter. Data was obtained at multiple chamber pressures, and calculations were performed for specific impulse, C* combustion efficiency, and thrust vector alignment. Test objectives for the RS-18 project are 1) conduct a shakedown of the test stand for LO2/methane lunar ascent engines, 2) obtain vacuum ignition data for the torch and pyrotechnic igniters, and 3) obtain nozzle kinetics data to anchor two-dimensional kinetics codes.

Development of reaching during mid-childhood from a Developmental Systems perspective.

PubMed

Golenia, Laura; Schoemaker, Marina M; Otten, Egbert; Mouton, Leonora J; Bongers, Raoul M

2018-01-01

Inspired by the Developmental Systems perspective, we studied the development of reaching during mid-childhood (5-10 years of age) not just at the performance level (i.e., endpoint movements), as commonly done in earlier studies, but also at the joint angle level. Because the endpoint position (i.e., the tip of the index finger) at the reaching target can be achieved with multiple joint angle combinations, we partitioned variability in joint angles over trials into variability that does not (goal-equivalent variability, GEV) and that does (non-goal-equivalent variability, NGEV) influence the endpoint position, using the Uncontrolled Manifold method. Quantifying this structure in joint angle variability allowed us to examine whether and how spatial variability of the endpoint at the reaching target is related to variability in joint angles and how this changes over development. 6-, 8- and 10-year-old children and young adults performed reaching movements to a target with the index finger. Polynomial trend analysis revealed a linear and a quadratic decreasing trend for the variable error. Linear decreasing and cubic trends were found for joint angle standard deviations at movement end. GEV and NGEV decreased gradually with age, but interestingly, the decrease of GEV was steeper than the decrease of NGEV, showing that the different parts of the joint angle variability changed differently over age. We interpreted these changes in the structure of variability as indicating changes over age in exploration for synergies (a family of task solutions), a concept that links the performance level with the joint angle level. Our results suggest changes in the search for synergies during mid-childhood development.

Defining local-regional control and its importance in locally advanced non-small cell lung carcinoma.

PubMed

Machtay, Mitchell; Paulus, Rebecca; Moughan, Jennifer; Komaki, Ritsuko; Bradley, J Effrey; Choy, Hak; Albain, Kathy; Movsas, Benjamin; Sause, William T; Curran, Walter J

2012-04-01

Local-regional control (LRC) rates for non-small cell lung cancer after chemoradiotherapy were studied (using two different definitions of LRC) for the association between LRC and survival. Seven legacy Radiation Therapy Ooncology Group trials of chemoradiotherapy for locally advanced non-small cell lung cancer were analyzed. Two different definitions of LRC were studied: (1) freedom from local progression (FFLP-LRC), the traditional Radiation Therapy Oncology Group methodology, in which a failure is intrathoracic tumor progression by World Health Oorganization criteria; and (2) response-mandatory (strict-LRC), in which any patient not achieving at least partial response was considered to have failure at day 0. Testing for associations between LRC and survival was performed using a Cox multivariate model that included other potential predictive factors. A total of 1390 patients were analyzed. The LRC rate at 3 years was 38% based on the FFLP-LRC definition and 14% based on the strict-LRC definition. Performance status, concurrent chemotherapy, and radiotherapy dose intensity (biologically equivalent dose) were associated with better LRC (using either definition). With the strict-LRC definition (but not FFLP-LRC), age was also important. There was a powerful association between LRC and overall survival (p, 0.0001) on univariate and multivariate analyses. Age, performance status, chemotherapy sequencing, and biologically equivalent dose were also significantly associated with survival. Histology and gender were also significant if the strict-LRC model was used. LRC is associated with survival. The definition of LRC affects the results of these analyses. A consensus definition of LRC, incorporating functional imaging and/or central review, is needed, with the possibility of using LRC as a surrogate end point in future trials.

Stimulus Equivalence, Generalization, and Contextual Stimulus Control in Verbal Classes

PubMed Central

Sigurðardóttir, Zuilma Gabriela; Mackay, Harry A; Green, Gina

2012-01-01

Stimulus generalization and contextual control affect the development of equivalence classes. Experiment 1 demonstrated primary stimulus generalization from the members of trained equivalence classes. Adults were taught to match six spoken Icelandic nouns and corresponding printed words and pictures to one another in computerized three-choice matching-to-sample tasks. Tests confirmed that six equivalence classes had formed. Without further training, plural forms of the stimuli were presented in tests for all matching performances. All participants demonstrated virtually errorless performances. In Experiment 2, classifications of the nouns used in Experiment 1 were brought under contextual control. Three nouns were feminine and three were masculine. The match-to-sample training taught participants to select a comparison of the same number as the sample (i.e., singular or plural) in the presence of contextual stimulus A regardless of noun gender. Concurrently, in the presence of contextual stimulus B, participants were taught to select a comparison of the same gender as the sample (i.e., feminine or masculine), regardless of number. Generalization was assessed using a card-sorting test. All participants eventually sorted the cards correctly into gender and number stimulus classes. When printed words used in training were replaced by their picture equivalents, participants demonstrated almost errorless performances. PMID:22754102

Equivalence of the Color Trails Test and Trail Making Test in nonnative English-speakers.

PubMed

Dugbartey, A T; Townes, B D; Mahurin, R K

2000-07-01

The Color Trails Test (CTT) has been described as a culture-fair test of visual attention, graphomotor sequencing, and effortful executive processing abilities relative to the Trail Making Test (TMT). In this study, the equivalence of the TMT and the CTT among a group of 64 bilingual Turkish university students was examined. No difference in performance on the CTT-1 and TMT Part A was found, suggesting functionally equivalent performance across both tasks. In contrast, the statistically significant differences in performance on CTT-2 and TMT Part B, as well as the interference indices for both tests, were interpreted as providing evidence for task nonequivalence of the CTT-2 and TMT Part B. Results have implications for both psychometric test development and clinical cultural neuropsychology.

Solar cell radiation handbook

NASA Technical Reports Server (NTRS)

Tada, H. Y.; Carter, J. R., Jr.; Anspaugh, B. E.; Downing, R. G.

1982-01-01

The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

A Physically Motivated and Empirically Calibrated Method to Measure the Effective Temperature, Metallicity, and Ti Abundance of M Dwarfs

NASA Astrophysics Data System (ADS)

Veyette, Mark J.; Muirhead, Philip S.; Mann, Andrew W.; Brewer, John M.; Allard, France; Homeier, Derek

2017-12-01

The ability to perform detailed chemical analysis of Sun-like F-, G-, and K-type stars is a powerful tool with many applications, including studying the chemical evolution of the Galaxy and constraining planet formation theories. Unfortunately, complications in modeling cooler stellar atmospheres hinders similar analyses of M dwarf stars. Empirically calibrated methods to measure M dwarf metallicity from moderate-resolution spectra are currently limited to measuring overall metallicity and rely on astrophysical abundance correlations in stellar populations. We present a new, empirical calibration of synthetic M dwarf spectra that can be used to infer effective temperature, Fe abundance, and Ti abundance. We obtained high-resolution (R ˜ 25,000), Y-band (˜1 μm) spectra of 29 M dwarfs with NIRSPEC on Keck II. Using the PHOENIX stellar atmosphere modeling code (version 15.5), we generated a grid of synthetic spectra covering a range of temperatures, metallicities, and alpha-enhancements. From our observed and synthetic spectra, we measured the equivalent widths of multiple Fe I and Ti I lines and a temperature-sensitive index based on the FeH band head. We used abundances measured from widely separated solar-type companions to empirically calibrate transformations to the observed indices and equivalent widths that force agreement with the models. Our calibration achieves precisions in T eff, [Fe/H], and [Ti/Fe] of 60 K, 0.1 dex, and 0.05 dex, respectively, and is calibrated for 3200 K < T eff < 4100 K, -0.7 < [Fe/H] < +0.3, and -0.05 < [Ti/Fe] < +0.3. This work is a step toward detailed chemical analysis of M dwarfs at a precision similar to what has been achieved for FGK stars.

Over 15 MA/cm2 of critical current density in 4.8 µm thick, Zr-doped (Gd,Y)Ba2Cu3Ox superconductor at 30 K, 3T.

PubMed

Majkic, Goran; Pratap, Rudra; Xu, Aixia; Galstyan, Eduard; Selvamanickam, Venkat

2018-05-03

An Advanced MOCVD (A-MOCVD) reactor was used to deposit 4.8 µm thick (Gd,Y)BaCuO tapes with 15 mol% Zr addition in a single pass. A record-high critical current density (J c ) of 15.11 MA/cm 2 has been measured over a bridge at 30 K, 3T, corresponding to an equivalent (I c ) value of 8705 A/12 mm width. This corresponds to a lift factor in critical current of ~11 which is the highest ever reported to the best of author's knowledge. The measured critical current densities at 3T (B||c) and 30, 40 and 50 K, respectively, are 15.11, 9.70 and 6.26 MA/cm 2 , corresponding to equivalent Ic values of 8705, 5586 and 3606 A/12 mm and engineering current densities (J e ) of 7068, 4535 and 2928 A/mm 2 . The engineering current density (J e ) at 40 K, 3T is 7 times higher than that of the commercial HTS tapes available with 7.5 mol% Zr addition. Such record-high performance in thick films (>1 µm) is a clear demonstration that growing thick REBCO films with high critical current density (J c ) is possible, contrary to the usual findings of strong J c degradation with film thickness. This achievement was possible due to a combination of strong temperature control and uniform laminar flow achieved in the A-MOCVD system, coupled with optimization of BaZrO 3 nanorod growth parameters.

Numerical and analytical investigation towards performance enhancement of a newly developed rockfall protective cable-net structure

NASA Astrophysics Data System (ADS)

Dhakal, S.; Bhandary, N. P.; Yatabe, R.; Kinoshita, N.

2012-04-01

In a previous companion paper, we presented a three-tier modelling of a particular type of rockfall protective cable-net structure (barrier), developed newly in Japan. Therein, we developed a three-dimensional, Finite Element based, nonlinear numerical model having been calibrated/back-calculated and verified with the element- and structure-level physical tests. Moreover, using a very simple, lumped-mass, single-degree-of-freedom, equivalently linear analytical model, a global-displacement-predictive correlation was devised by modifying the basic equation - obtained by combining the principles of conservation of linear momentum and energy - based on the back-analysis of the tests on the numerical model. In this paper, we use the developed models to explore the performance enhancement potential of the structure in terms of (a) the control of global displacement - possibly the major performance criterion for the proposed structure owing to a narrow space available in the targeted site, and (b) the increase in energy dissipation by the existing U-bolt-type Friction-brake Devices - which are identified to have performed weakly when integrated into the structure. A set of parametric investigations have revealed correlations to achieve the first objective in terms of the structure's mass, particularly by manipulating the wire-net's characteristics, and has additionally disclosed the effects of the impacting-block's parameters. Towards achieving the second objective, another set of parametric investigations have led to a proposal of a few innovative improvements in the constitutive behaviour (model) of the studied brake device (dissipator), in addition to an important recommendation of careful handling of the device based on the identified potential flaw.

Self-tuning stochastic resonance energy harvester for smart tires

NASA Astrophysics Data System (ADS)

Kim, Hongjip; Tai, Wei Che; Zuo, Lei

2018-03-01

Energy harvesting from smart tire has been an influential topic for researchers over several years. In this paper, we propose novel energy harvester for smart tire taking advantage of adaptive tuning stochastic resonance. Compared to previous tire energy harvesters, it can generate large power and has wide bandwidth. Large power is achieved by stochastic resonance while wide-bandwidth is accomplished by adaptive tuning via centrifugal stiffening effect. Energy harvesting configuration for modulated noise is described first. It is an electromagnetic energy harvester consists of rotating beam subject to centrifugal buckling. Equation of motion for energy harvester is derived to investigate the effect of centrifugal stiffening. Numerical analysis was conducted to simulate response. The result show that high power is achieved with wide bandwidth. To verify the theoretical and simulation results, the experiment was conducted. Equivalent horizontal rotating platform is built to mimic tire environment. Experiment results showed good agreement with the numerical result with around 10% of errors, which verified feasibility of proposed harvester. Maximum power 1.8mW is achieved from 3:1 scale experiment setup. The equivalent working range of harvester is around 60-105 km/h which is typical speed for car in general road and highway.

3D-Printing of Meso-structurally Ordered Carbon Fiber/Polymer Composites with Unprecedented Orthotropic Physical Properties

NASA Astrophysics Data System (ADS)

Lewicki, James P.; Rodriguez, Jennifer N.; Zhu, Cheng; Worsley, Marcus A.; Wu, Amanda S.; Kanarska, Yuliya; Horn, John D.; Duoss, Eric B.; Ortega, Jason M.; Elmer, William; Hensleigh, Ryan; Fellini, Ryan A.; King, Michael J.

2017-03-01

Here we report the first example of a class of additively manufactured carbon fiber reinforced composite (AMCFRC) materials which have been achieved through the use of a latent thermal cured aromatic thermoset resin system, through an adaptation of direct ink writing (DIW) 3D-printing technology. We have developed a means of printing high performance thermoset carbon fiber composites, which allow the fiber component of a resin and carbon fiber fluid to be aligned in three dimensions via controlled micro-extrusion and subsequently cured into complex geometries. Characterization of our composite systems clearly show that we achieved a high order of fiber alignment within the composite microstructure, which in turn allows these materials to outperform equivalently filled randomly oriented carbon fiber and polymer composites. Furthermore, our AM carbon fiber composite systems exhibit highly orthotropic mechanical and electrical responses as a direct result of the alignment of carbon fiber bundles in the microscale which we predict will ultimately lead to the design of truly tailorable carbon fiber/polymer hybrid materials having locally programmable complex electrical, thermal and mechanical response.

3D-Printing of Meso-structurally Ordered Carbon Fiber/Polymer Composites with Unprecedented Orthotropic Physical Properties

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

Lewicki, James P.; Rodriguez, Jennifer N.; Zhu, Cheng

Here we report the first example of a class of additively manufactured carbon fiber reinforced composite (AMCFRC) materials which have been achieved through the use of a latent thermal cured aromatic thermoset resin system, through an adaptation of direct ink writing (DIW) 3D-printing technology. We have developed a means of printing high performance thermoset carbon fiber composites, which allow the fiber component of a resin and carbon fiber fluid to be aligned in three dimensions via controlled micro-extrusion and subsequently cured into complex geometries. Characterization of our composite systems clearly show that we achieved a high order of fiber alignmentmore » within the composite microstructure, which in turn allows these materials to outperform equivalently filled randomly oriented carbon fiber and polymer composites. Moreover, our AM carbon fiber composite systems exhibit highly orthotropic mechanical and electrical responses as a direct result of the alignment of carbon fiber bundles in the microscale which we predict will ultimately lead to the design of truly tailorable carbon fiber/polymer hybrid materials having locally programmable complex electrical, thermal and mechanical response.« less

3D-Printing of Meso-structurally Ordered Carbon Fiber/Polymer Composites with Unprecedented Orthotropic Physical Properties

DOE PAGES

Lewicki, James P.; Rodriguez, Jennifer N.; Zhu, Cheng; ...

2017-03-06

Here we report the first example of a class of additively manufactured carbon fiber reinforced composite (AMCFRC) materials which have been achieved through the use of a latent thermal cured aromatic thermoset resin system, through an adaptation of direct ink writing (DIW) 3D-printing technology. We have developed a means of printing high performance thermoset carbon fiber composites, which allow the fiber component of a resin and carbon fiber fluid to be aligned in three dimensions via controlled micro-extrusion and subsequently cured into complex geometries. Characterization of our composite systems clearly show that we achieved a high order of fiber alignmentmore » within the composite microstructure, which in turn allows these materials to outperform equivalently filled randomly oriented carbon fiber and polymer composites. Moreover, our AM carbon fiber composite systems exhibit highly orthotropic mechanical and electrical responses as a direct result of the alignment of carbon fiber bundles in the microscale which we predict will ultimately lead to the design of truly tailorable carbon fiber/polymer hybrid materials having locally programmable complex electrical, thermal and mechanical response.« less

Enhanced ν-optical time domain reflectometry using gigahertz sinusoidally gated InGaAs/InP single-photon avalanche detector

NASA Astrophysics Data System (ADS)

Zhang, Xuping; Shi, Yuanlei; Shan, Yuanyuan; Sun, Zhenhong; Qiao, Weiyan; Zhang, Yixin

2016-09-01

Optical time domain reflectometry (OTDR) is one of the most successful diagnostic tools for nondestructive attenuation measurement of a fiber link. To achieve better sensitivity, spatial resolution, and avoid dead-zone in conversional OTDR, a single-photon detector has been introduced to form the photon-counting OTDR (ν-OTDR). We have proposed a ν-OTDR system using a gigahertz sinusoidally gated InGaAs/InP single-photon avalanche detector (SPAD). Benefiting from the superior performance of a sinusoidal gated SPAD on dark count probability, gating frequency, and gate duration, our ν-OTDR system has achieved a dynamic range (DR) of 33.4 dB with 1 μs probe pulse width after an equivalent measurement time of 51 s. This obtainable DR corresponds to a sensing length over 150 km. Our system has also obtained a spatial resolution of 5 cm at the end of a 5-km standard single-mode fiber. By employing a sinusoidal gating technique, we have improved the ν-OTDR spatial resolution and significantly reduced the measurement time.

The economic production of alcohol fuels from coal-derived synthesis gas

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

Kugler, E.L.; Dadyburjor, D.B.; Yang, R.Y.K.

1995-12-31

The objectives of this project are to discover, (1) study and evaluate novel heterogeneous catalytic systems for the production of oxygenated fuel enhancers from synthesis gas. Specifically, alternative methods of preparing catalysts are to be investigated, and novel catalysts, including sulfur-tolerant ones, are to be pursued. (Task 1); (2) explore, analytically and on the bench scale, novel reactor and process concepts for use in converting syngas to liquid fuel products. (Task 1); (3) simulate by computer the most energy efficient and economically efficient process for converting coal to energy, with primary focus on converting syngas to fuel alcohols. (Task 2);more » (4) develop on the bench scale the best holistic combination of chemistry, catalyst, reactor and total process configuration integrated with the overall coal conversion process to achieve economic optimization for the conversion of syngas to liquid products within the framework of achieving the maximum cost effective transformation of coal to energy equivalents. (Tasks 1 and 2); and (5) evaluate the combustion, emission and performance characteristics of fuel alcohols and blends of alcohols with petroleum-based fuels. (Task 2)« less

A neutron dosemeter for nuclear criticality accidents.

PubMed

d'Errico, F; Curzio, G; Ciolini, R; Del Gratta, A; Nath, R

2004-01-01

A neutron dosemeter which offers instant read-out has been developed for nuclear criticality accidents. The system is based on gels containing emulsions of superheated dichlorodifluoromethane droplets, which vaporise into bubbles upon neutron irradiation. The expansion of these bubbles displaces an equivalent volume of gel into a graduated pipette, providing an immediate measure of the dose. Instant read-out is achieved using an array of transmissive optical sensors which consist of coupled LED emitters and phototransistor receivers. When the gel displaced in the pipette crosses the sensing region of the photomicrosensors, it generates a signal collected on a computer through a dedicated acquisition board. The performance of the device was tested during the 2002 International Accident Dosimetry Intercomparison in Valduc, France. The dosemeter was able to follow the initial dose gradient of a simulated accident, providing accurate values of neutron kerma; however, the emulsion was rapidly depleted of all its drops. A model of the depletion effects was developed and it indicates that an adequate dynamic range of the dose response can be achieved by using emulsions of smaller droplets.

3D-Printing of Meso-structurally Ordered Carbon Fiber/Polymer Composites with Unprecedented Orthotropic Physical Properties.

PubMed

Lewicki, James P; Rodriguez, Jennifer N; Zhu, Cheng; Worsley, Marcus A; Wu, Amanda S; Kanarska, Yuliya; Horn, John D; Duoss, Eric B; Ortega, Jason M; Elmer, William; Hensleigh, Ryan; Fellini, Ryan A; King, Michael J

2017-03-06

Here we report the first example of a class of additively manufactured carbon fiber reinforced composite (AMCFRC) materials which have been achieved through the use of a latent thermal cured aromatic thermoset resin system, through an adaptation of direct ink writing (DIW) 3D-printing technology. We have developed a means of printing high performance thermoset carbon fiber composites, which allow the fiber component of a resin and carbon fiber fluid to be aligned in three dimensions via controlled micro-extrusion and subsequently cured into complex geometries. Characterization of our composite systems clearly show that we achieved a high order of fiber alignment within the composite microstructure, which in turn allows these materials to outperform equivalently filled randomly oriented carbon fiber and polymer composites. Furthermore, our AM carbon fiber composite systems exhibit highly orthotropic mechanical and electrical responses as a direct result of the alignment of carbon fiber bundles in the microscale which we predict will ultimately lead to the design of truly tailorable carbon fiber/polymer hybrid materials having locally programmable complex electrical, thermal and mechanical response.

3D-Printing of Meso-structurally Ordered Carbon Fiber/Polymer Composites with Unprecedented Orthotropic Physical Properties

PubMed Central

Lewicki, James P.; Rodriguez, Jennifer N.; Zhu, Cheng; Worsley, Marcus A.; Wu, Amanda S.; Kanarska, Yuliya; Horn, John D.; Duoss, Eric B.; Ortega, Jason M.; Elmer, William; Hensleigh, Ryan; Fellini, Ryan A.; King, Michael J.

2017-01-01

Here we report the first example of a class of additively manufactured carbon fiber reinforced composite (AMCFRC) materials which have been achieved through the use of a latent thermal cured aromatic thermoset resin system, through an adaptation of direct ink writing (DIW) 3D-printing technology. We have developed a means of printing high performance thermoset carbon fiber composites, which allow the fiber component of a resin and carbon fiber fluid to be aligned in three dimensions via controlled micro-extrusion and subsequently cured into complex geometries. Characterization of our composite systems clearly show that we achieved a high order of fiber alignment within the composite microstructure, which in turn allows these materials to outperform equivalently filled randomly oriented carbon fiber and polymer composites. Furthermore, our AM carbon fiber composite systems exhibit highly orthotropic mechanical and electrical responses as a direct result of the alignment of carbon fiber bundles in the microscale which we predict will ultimately lead to the design of truly tailorable carbon fiber/polymer hybrid materials having locally programmable complex electrical, thermal and mechanical response. PMID:28262669

Initial resident refractive surgical experience: outcomes of PRK and LASIK for myopia.

PubMed

Wagoner, Michael D; Wickard, Joseph C; Wandling, George R; Milder, Lisa C; Rauen, Matthew P; Kitzmann, Anna S; Sutphin, John E; Goins, Kenneth M

2011-03-01

To evaluate and compare the outcome of initial resident surgical experience with photorefractive keratectomy (PRK) and LASIK. Retrospective review of all cases performed with the VISX Star S4 platform (Abbott Medical Optics) between July 1, 2003 and June 30, 2007. Inclusion criteria were spherical equivalent of -0.50 to -10.00 diopters (D), refractive astigmatic error of ≤3.00 D, intention to provide full distance correction, and minimum 3-month postoperative follow-up after initial ablation or retreatment (if performed). A total of 153 cases performed by 20 different residents met the inclusion criteria; 38 eyes underwent PRK and 115 eyes had LASIK. After initial treatment, mean Snellen uncorrected distance visual acuity (UDVA) after PRK was 20/17.3 and after LASIK was 20/19.5. Photorefractive keratectomy was associated with a significantly better approximation between preoperative corrected distance visual acuity (CDVA) and postoperative UDVA (ΔlogMAR 0.009 vs 0.091; P=.004) and a greater percentage of eyes that achieved UDVA of 20/20 or better (94.7% vs 78.3%; P=.02) or 20/30 or better (100% vs 87.8%; P=.02). There was a higher prevalence of retreatment in eyes that underwent LASIK (7.0% vs 0%; P=.20). One (0.9%) eye lost 2 lines of CDVA after LASIK. Supervised refractive surgery residents can achieve excellent visual outcomes in patients operated during their initial refractive experience. Photorefractive keratectomy was associated with better visual outcome than LASIK. Copyright 2011, SLACK Incorporated.

Hydrogen-enriched fuels

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

Roser, R.

1998-08-01

NRG Technologies, Inc. is attempting to develop hardware and infrastructure that will allow mixtures of hydrogen and conventional fuels to become viable alternatives to conventional fuels alone. This commercialization can be successful if the authors are able to achieve exhaust emission levels of less than 0.03 g/kw-hr NOx and CO; and 0.15 g/kw-hr NMHC at full engine power without the use of exhaust catalysts. The major barriers to achieving these goals are that the lean burn regimes required to meet exhaust emissions goals reduce engine output substantially and tend to exhibit higher-than-normal total hydrocarbon emissions. Also, hydrogen addition to conventionalmore » fuels increases fuel cost, and reduces both vehicle range and engine output power. Maintaining low emissions during transient driving cycles has not been demonstrated. A three year test plan has been developed to perform the investigations into the issues described above. During this initial year of funding research has progressed in the following areas: (a) a cost effective single-cylinder research platform was constructed; (b) exhaust gas speciation was performed to characterize the nature of hydrocarbon emissions from hydrogen-enriched natural gas fuels; (c) three H{sub 2}/CH{sub 4} fuel compositions were analyzed using spark timing and equivalence ratio sweeping procedures and finally; (d) a full size pick-up truck platform was converted to run on HCNG fuels. The testing performed in year one of the three year plan represents a baseline from which to assess options for overcoming the stated barriers to success.« less

Adaptive Sliding Mode Control of Dynamic Systems Using Double Loop Recurrent Neural Network Structure.

PubMed

Fei, Juntao; Lu, Cheng

2018-04-01

In this paper, an adaptive sliding mode control system using a double loop recurrent neural network (DLRNN) structure is proposed for a class of nonlinear dynamic systems. A new three-layer RNN is proposed to approximate unknown dynamics with two different kinds of feedback loops where the firing weights and output signal calculated in the last step are stored and used as the feedback signals in each feedback loop. Since the new structure has combined the advantages of internal feedback NN and external feedback NN, it can acquire the internal state information while the output signal is also captured, thus the new designed DLRNN can achieve better approximation performance compared with the regular NNs without feedback loops or the regular RNNs with a single feedback loop. The new proposed DLRNN structure is employed in an equivalent controller to approximate the unknown nonlinear system dynamics, and the parameters of the DLRNN are updated online by adaptive laws to get favorable approximation performance. To investigate the effectiveness of the proposed controller, the designed adaptive sliding mode controller with the DLRNN is applied to a -axis microelectromechanical system gyroscope to control the vibrating dynamics of the proof mass. Simulation results demonstrate that the proposed methodology can achieve good tracking property, and the comparisons of the approximation performance between radial basis function NN, RNN, and DLRNN show that the DLRNN can accurately estimate the unknown dynamics with a fast speed while the internal states of DLRNN are more stable.

A Versatile High Speed 250 MHz Pulse Imager for Biomedical Applications

PubMed Central

Epel, Boris; Sundramoorthy, Subramanian V.; Mailer, Colin; Halpern, Howard J.

2009-01-01

A versatile 250 MHz pulse electron paramagnetic resonance (EPR) instrument for imaging of small animals is presented. Flexible design of the imager hardware and software makes it possible to use virtually any pulse EPR imaging modality. A fast pulse generation and data acquisition system based on general purpose PCI boards performs measurements with minimal additional delays. Careful design of receiver protection circuitry allowed us to achieve very high sensitivity of the instrument. In this article we demonstrate the ability of the instrument to obtain three dimensional images using the electron spin echo (ESE) and single point imaging (SPI) methods. In a phantom that contains a 1 mM solution of narrow line (16 μT, peak-to-peak) paramagnetic spin probe we achieved an acquisition time of 32 seconds per image with a fast 3D ESE imaging protocol. Using an 18 minute 3D phase relaxation (T2e) ESE imaging protocol in a homogeneous sample a spatial resolution of 1.4 mm and a standard deviation of T2e of 8.5% were achieved. When applied to in vivo imaging this precision of T2e determination would be equivalent to 2 torr resolution of oxygen partial pressure in animal tissues. PMID:19924261

High-efficient Extraction of Drainage Networks from Digital Elevation Model Data Constrained by Enhanced Flow Enforcement from Known River Map

NASA Astrophysics Data System (ADS)

Wu, T.; Li, T.; Li, J.; Wang, G.

2017-12-01

Improved drainage network extraction can be achieved by flow enforcement whereby information of known river maps is imposed to the flow-path modeling process. However, the common elevation-based stream burning method can sometimes cause unintended topological errors and misinterpret the overall drainage pattern. We presented an enhanced flow enforcement method to facilitate accurate and efficient process of drainage network extraction. Both the topology of the mapped hydrography and the initial landscape of the DEM are well preserved and fully utilized in the proposed method. An improved stream rasterization is achieved here, yielding continuous, unambiguous and stream-collision-free raster equivalent of stream vectors for flow enforcement. By imposing priority-based enforcement with a complementary flow direction enhancement procedure, the drainage patterns of the mapped hydrography are fully represented in the derived results. The proposed method was tested over the Rogue River Basin, using DEMs with various resolutions. As indicated by the visual and statistical analyses, the proposed method has three major advantages: (1) it significantly reduces the occurrences of topological errors, yielding very accurate watershed partition and channel delineation, (2) it ensures scale-consistent performance at DEMs of various resolutions, and (3) the entire extraction process is well-designed to achieve great computational efficiency.

Linear optical pulse compression based on temporal zone plates.

PubMed

Li, Bo; Li, Ming; Lou, Shuqin; Azaña, José

2013-07-15

We propose and demonstrate time-domain equivalents of spatial zone plates, namely temporal zone plates, as alternatives to conventional time lenses. Both temporal intensity zone plates, based on intensity-only temporal modulation, and temporal phase zone plates, based on phase-only temporal modulation, are introduced and studied. Temporal zone plates do not exhibit the limiting tradeoff between temporal aperture and frequency bandwidth (temporal resolution) of conventional linear time lenses. As a result, these zone plates can be ideally designed to offer a time-bandwidth product (TBP) as large as desired, practically limited by the achievable temporal modulation bandwidth (limiting the temporal resolution) and the amount of dispersion needed in the target processing systems (limiting the temporal aperture). We numerically and experimentally demonstrate linear optical pulse compression by using temporal zone plates based on linear electro-optic temporal modulation followed by fiber-optics dispersion. In the pulse-compression experiment based on temporal phase zone plates, we achieve a resolution of ~25.5 ps over a temporal aperture of ~5.77 ns, representing an experimental TBP larger than 226 using a phase-modulation amplitude of only ~0.8π rad. We also numerically study the potential of these devices to achieve temporal imaging of optical waveforms and present a comparative analysis on the performance of different temporal intensity and phase zone plates.

Ultra-Sensitive Transition-Edge Sensors for the Background Limited Infrared/Sub-mm Spectrograph (BLISS)

NASA Technical Reports Server (NTRS)

Beyer, A. D.; Kenyon, M. E.; Echternach, P. M.; Chui, T.; Eom, B.-H.; Day, P. K.; Bock, J. J.; Holmes, W.A.; Bradford, C. M.

2011-01-01

We report progress in fabricating ultra-sensitive superconducting transition-edge sensors (TESs) for BLISS. BLISS is a suite of grating spectrometers covering 35-433 micron with R approx. 700 cooled to 50 mK that is proposed to fly on the Japanese space telescope SPICA. The detector arrays for BLISS are TES bolometers readout with a time domain SQUID multiplexer. The required noise equivalent power (NEP) for BLISS is NEP = 10(exp -19) W/Hz(exp 1/2) with an ultimate goal of NEP= 5 x 10(exp -20) W/Hz(exp 1/2) to achieve background limited noise performance. The required and goal response times are tau = 150 ms and tau = 50ms respectively to achieve the NEP at the required and goal optical chop frequency 1-5 Hz. We measured prototype BLISS arrays and have achieved NEP = 6 x 10(exp -18) W/Hz(exp 1/2) and tau = 1.4 ms with a Ti TES (T(sub C) = 565 mK) and NEP approx. 2.5 x 10(exp -19) W/Hz(exp 1/2) and tau approximates 4.5 ms with an Ir TES (T(sub C) = 130 mK). Dark power for these tests is estimated at 1-5 fW.

Cultural adaptation to Brazilian Portuguese of the Face, Legs, Activity, Cry, Consolability revised (FLACCr) scale of pain assessment.

PubMed

Bussotti, Edna Aparecida; Guinsburg, Ruth; Pedreira, Mavilde da Luz Gonçalves

2015-01-01

to perform the translation into Brazilian Portuguese and cultural adaptation of the Face, Legs, Activity, Cry, Consolability revised (FLACCr) scale, with children under 18 years old, affected by cerebral palsy, presenting or not cognitive impairment and unable to report their pain. methodological development study of translation into Portuguese and cultural adaptation of the FLACCr. After approval by the ethics committee, the process aimed at translation and back-translation, evaluation of translation and back-translation using the Delphi technique and assessment of cultural equivalence. The process included the five categories of the scale and the four application instructions, considering levels of agreement equal to or greater than 80%. it was necessary three rounds of the Delphi technique to achieve consensus among experts. The agreement achieved for the five categories was: Face 95.5%, Legs 90%, Activity 94.4%, Cry 94.4% and Consolability 99.4%. The four instructions achieved the following consensus levels: 1st 99.1%, 2nd 99.2%, 3rd 99.1% and 4th 98.3%. the method enabled the translation and cultural adaptation of the FLACCr. This is a study able to expand the knowledge of Brazilian professionals on pain assessment in children with CP.

Static Feed Water Electrolysis Subsystem Testing and Component Development

NASA Technical Reports Server (NTRS)

Koszenski, E. P.; Schubert, F. H.; Burke, K. A.

1983-01-01

A program was carried out to develop and test advanced electrochemical cells/modules and critical electromechanical components for a static feed (alkaline electrolyte) water electrolysis oxygen generation subsystem. The accomplishments were refurbishment of a previously developed subsystem and successful demonstration for a total of 2980 hours of normal operation; achievement of sustained one-person level oxygen generation performance with state-of-the-art cell voltages averaging 1.61 V at 191 ASF for an operating temperature of 128F (equivalent to 1.51V when normalized to 180F); endurance testing and demonstration of reliable performance of the three-fluid pressure controller for 8650 hours; design and development of a fluid control assembly for this subsystem and demonstration of its performance; development and demonstration at the single cell and module levels of a unitized core composite cell that provides expanded differential pressure tolerance capability; fabrication and evaluation of a feed water electrolyte elimination five-cell module; and successful demonstration of an electrolysis module pressurization technique that can be used in place of nitrogen gas during the standby mode of operation to maintain system pressure and differential pressures.

The continuous measurement of hydrogen chloride in the ambient atmosphere using the dual isotope infrared absorption technique

NASA Technical Reports Server (NTRS)

Williams, K. G.

1974-01-01

The results of a program to develop a prototype gas filter correlation NDIR analyzer capable of providing the required HCl measurement capability, while maintaining an adequate rejection of any other gases anticipated in the atmosphere are presented. Examples of the performance of the prototype analyzer are presented which show an rms noise equivalent concentration of 0.06 ppm of HCl was achieved while maintaining an electronically determined 10% to 90% time response to gas samples of about 2 seconds. No measureable response was observed to CO2, CO, and H2O while maintaining an adequate rejection of the hydrocarbons, for example CH4 and n-hexane. The experiments were performed which demonstrate that the span stability of the HCl gas filter correlation analyzer is unaffected by the presence of water vapor and which support the belief that the incorporation of a relatively open-volume, multiple path sample cell into the instrument would enable ground station as well as airborne measurements of trace quantities of HCl in the ambient atmosphere to be performed.

Coevolutionary Free Lunches

NASA Technical Reports Server (NTRS)

Wolpert, David H.; Macready, William G.

2005-01-01

Recent work on the foundations of optimization has begun to uncover its underlying rich structure. In particular, the "No Free Lunch" (NFL) theorems [WM97] state that any two algorithms are equivalent when their performance is averaged across all possible problems. This highlights the need for exploiting problem-specific knowledge to achieve better than random performance. In this paper we present a general framework covering most search scenarios. In addition to the optimization scenarios addressed in the NFL results, this framework covers multi-armed bandit problems and evolution of multiple co-evolving agents. As a particular instance of the latter, it covers "self-play" problems. In these problems the agents work together to produce a champion, who then engages one or more antagonists in a subsequent multi-player game In contrast to the traditional optimization case where the NFL results hold, we show that in self-play there are free lunches: in coevolution some algorithms have better performance than other algorithms, averaged across all possible problems. However in the typical coevolutionary scenarios encountered in biology, where there is no champion, NFL still holds.

10 CFR 63.111 - Performance objectives for the geologic repository operations area through permanent closure.

Code of Federal Regulations, 2013 CFR

2013-01-01

... of the deep dose equivalent and the committed dose equivalent to any individual organ or tissue (other than the lens of the eye) of 0.5 Sv (50 rem). The lens dose equivalent may not exceed 0.15 Sv (15... TEDE (hereafter referred to as “dose”) to any real member of the public located beyond the boundary of...

10 CFR 63.111 - Performance objectives for the geologic repository operations area through permanent closure.

Code of Federal Regulations, 2012 CFR

2012-01-01

... of the deep dose equivalent and the committed dose equivalent to any individual organ or tissue (other than the lens of the eye) of 0.5 Sv (50 rem). The lens dose equivalent may not exceed 0.15 Sv (15... TEDE (hereafter referred to as “dose”) to any real member of the public located beyond the boundary of...

10 CFR 63.111 - Performance objectives for the geologic repository operations area through permanent closure.

Code of Federal Regulations, 2014 CFR

2014-01-01

... of the deep dose equivalent and the committed dose equivalent to any individual organ or tissue (other than the lens of the eye) of 0.5 Sv (50 rem). The lens dose equivalent may not exceed 0.15 Sv (15... TEDE (hereafter referred to as “dose”) to any real member of the public located beyond the boundary of...

10 CFR 63.111 - Performance objectives for the geologic repository operations area through permanent closure.

Code of Federal Regulations, 2011 CFR

2011-01-01

... of the deep dose equivalent and the committed dose equivalent to any individual organ or tissue (other than the lens of the eye) of 0.5 Sv (50 rem). The lens dose equivalent may not exceed 0.15 Sv (15... TEDE (hereafter referred to as “dose”) to any real member of the public located beyond the boundary of...

The Effects of Different Training Structures in the Establishment of Conditional Discriminations and Subsequent Performance on Tests for Stimulus Equivalence

ERIC Educational Resources Information Center

Arntzen, Erik; Grondahl, Terje; Eilifsen, Christoffer

2010-01-01

Previous studies comparing groups of subjects have indicated differential probabilities of stimulus equivalence outcome as a function of training structures. One-to-Many (OTM) and Many-to-One (MTO) training structures seem to produce positive outcomes on tests for stimulus equivalence more often than a Linear Series (LS) training structure does.…

A Performance Management Framework for Civil Engineering

DTIC Science & Technology

1990-09-01

cultural change. A non - equivalent control group design was chosen to augment the case analysis. Figure 3.18 shows the form of the quasi-experiment. The...The non - equivalent control group design controls the following obstacles to internal validity: history, maturation, testing, and instrumentation. The...and Stanley, 1963:48,50) Table 7. Validity of Quasi-Experiment The non - equivalent control group experimental design controls the following obstacles to

Micro-structural integrity of dental enamel subjected to two tooth whitening regimes.

PubMed

Tanaka, Reina; Shibata, Yo; Manabe, Atsufumi; Miyazaki, Takashi

2010-04-01

Colour modification of tooth enamel has proven successful, but it is unclear how various bleaching applications affect micro-structural integrity of the whitened enamel. To investigate the internal structural integrity of human intact tooth enamel with the application of two commonly used whitening regimes (in-office power bleaching with 35% hydrogen peroxide and home bleaching with 10% carbamide peroxide), evaluations were performed on teeth of identical colour classification. After the bleaching applications, the enamel mineral density was quantified and visualised with micro-computed tomography. The micro-structural differences between the whitened tooth enamel samples were distinctive, though the colour parameter changes within the samples were equivalent. Home bleaching achieved colour modification by demineralisation, whereas in-office bleaching depended on redistribution of the minerals after treatment and subsequent enhanced mineralisation.

Chemically deposited nano grain composed MoS(2) thin films for supercapacitor application.

PubMed

Pujari, R B; Lokhande, A C; Shelke, A R; Kim, J H; Lokhande, C D

2017-06-15

Low temperature soft chemical synthesis approach is employed towards MoS 2 thin film preparation on cost effective stainless steel substrate. 3-D semispherical nano-grain composed surface texture of MoS 2 film is observed through FE-SEM technique. Electrochemical supercapacitor performance of MoS 2 film is tested from cyclic voltammetry (CV) and galvanostatic charge discharge (GCD) techniques in 1M aqueous Na 2 SO 4 electrolyte. Specific capacitance (C s ) of 180Fg -1 with CV cycling stability of 82% for 1000 cycles is achieved. Equivalent series resistance (R s ) of 1.78Ωcm -2 observed through Nyquist plot shows usefulness of MoS 2 thin film for charge conduction in supercapacitor application. Copyright © 2016. Published by Elsevier Inc.

UWB Bandpass Filter with Ultra-wide Stopband based on Ring Resonator

NASA Astrophysics Data System (ADS)

Kazemi, Maryam; Lotfi, Saeedeh; Siahkamari, Hesam; Mohammadpanah, Mahmood

2018-04-01

An ultra-wideband (UWB) bandpass filter with ultra-wide stopband based on a rectangular ring resonator is presented. The filter is designed for the operational frequency band from 4.10 GHz to 10.80 GHz with an ultra-wide stopband from 11.23 GHz to 40 GHz. The even and odd equivalent circuits are used to achieve a suitable analysis of the proposed filter performance. To verify the design and analysis, the proposed bandpass filter is simulated using full-wave EM simulator Advanced Design System and fabricated on a 20mil thick Rogers_RO4003 substrate with relative permittivity of 3.38 and a loss tangent of 0.0021. The proposed filter behavior is investigated and simulation results are in good agreement with measurement results.

Least reliable bits coding (LRBC) for high data rate satellite communications

NASA Technical Reports Server (NTRS)

Vanderaar, Mark; Budinger, James; Wagner, Paul

1992-01-01

LRBC, a bandwidth efficient multilevel/multistage block-coded modulation technique, is analyzed. LRBC uses simple multilevel component codes that provide increased error protection on increasingly unreliable modulated bits in order to maintain an overall high code rate that increases spectral efficiency. Soft-decision multistage decoding is used to make decisions on unprotected bits through corrections made on more protected bits. Analytical expressions and tight performance bounds are used to show that LRBC can achieve increased spectral efficiency and maintain equivalent or better power efficiency compared to that of BPSK. The relative simplicity of Galois field algebra vs the Viterbi algorithm and the availability of high-speed commercial VLSI for block codes indicates that LRBC using block codes is a desirable method for high data rate implementations.

Equivalent theories redefine Hamiltonian observables to exhibit change in general relativity

NASA Astrophysics Data System (ADS)

Pitts, J. Brian

2017-03-01

Change and local spatial variation are missing in canonical General Relativity’s observables as usually defined, an aspect of the problem of time. Definitions can be tested using equivalent formulations of a theory, non-gauge and gauge, because they must have equivalent observables and everything is observable in the non-gauge formulation. Taking an observable from the non-gauge formulation and finding the equivalent in the gauge formulation, one requires that the equivalent be an observable, thus constraining definitions. For massive photons, the de Broglie-Proca non-gauge formulation observable {{A}μ} is equivalent to the Stueckelberg-Utiyama gauge formulation quantity {{A}μ}+{{\\partial}μ}φ, which must therefore be an observable. To achieve that result, observables must have 0 Poisson bracket not with each first-class constraint, but with the Rosenfeld-Anderson-Bergmann-Castellani gauge generator G, a tuned sum of first-class constraints, in accord with the Pons-Salisbury-Sundermeyer definition of observables. The definition for external gauge symmetries can be tested using massive gravity, where one can install gauge freedom by parametrization with clock fields X A . The non-gauge observable {{g}μ ν} has the gauge equivalent {{X}A}{{,}μ}{{g}μ ν}{{X}B}{{,}ν}. The Poisson bracket of {{X}A}{{,}μ}{{g}μ ν}{{X}B}{{,}ν} with G turns out to be not 0 but a Lie derivative. This non-zero Poisson bracket refines and systematizes Kuchař’s proposal to relax the 0 Poisson bracket condition with the Hamiltonian constraint. Thus observables need covariance, not invariance, in relation to external gauge symmetries. The Lagrangian and Hamiltonian for massive gravity are those of General Relativity  +   Λ   +  4 scalars, so the same definition of observables applies to General Relativity. Local fields such as {{g}μ ν} are observables. Thus observables change. Requiring equivalent observables for equivalent theories also recovers Hamiltonian-Lagrangian equivalence.

Improving the ablation efficiency of excimer laser systems with higher repetition rates through enhanced debris removal and optimized spot pattern.

PubMed

Arba-Mosquera, Samuel; Klinner, Thomas

2014-03-01

To evaluate the reasons for the required increased radiant exposure for higher-repetition-rate excimer lasers and determine experimentally possible compensations to achieve equivalent ablation profiles maintaining the same single-pulse energies and radiant exposures for laser repetition rates ranging from 430 to 1000 Hz. Schwind eye-tech-solutions GmbH and Co. KG, Kleinostheim, Germany. Experimental study. Poly(methyl methacrylate) (PMMA) plates were photoablated. The pulse laser energy was maintained during all experiments; the effects of the flow of the debris removal, the shot pattern for the correction, and precooling the PMMA plates were evaluated in terms of achieved ablation versus repetition rate. The mean ablation performance ranged from 88% to 100%; the variability between the profile measurements ranged from 1.4% to 6.2%. Increasing the laser repetition rate from 430 Hz to 1000 Hz reduced the mean ablation performance from 98% to 91% and worsened the variability from 1.9% to 4.3%. Increasing the flow of the debris removal, precooling the PMMA plates to -18°C, and adapting the shot pattern for the thermal response of PMMA to excimer ablation helped stabilize the variability. Only adapting the shot pattern for the thermal response of PMMA to excimer ablation helped stabilize the mean ablation performance. The ablation performance of higher-repetition-rate excimer lasers on PMMA improved with improvements in the debris removal systems and shot pattern. More powerful debris removal systems and smart shot patterns in terms of thermal response improved the performance of these excimer lasers. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Achievement, Engagement, and Behavior Outcomes of Youth at Risk Following a Pre-Eighth-Grade Summer Academic Enrichment Program and Participation in a School-Wide, School Year Long, Ownership, Mastery, and Grading Initiative

ERIC Educational Resources Information Center

Alati, David K.

2011-01-01

No significant differences in beginning eighth-grade pretest compared to ending eighth-grade posttest California Achievement Test Normal Curve Equivalent Scores were found for youth at risk who completed a pre-eighth-grade summer academic enrichment program where comparisons for reading vocabulary t(19) = 0.46, p = 0.33 (one-tailed), d = 0.107,…

14 CFR 121.907 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... available to crewmembers, including each other, to achieve a safe and efficient flight. Curriculum outline means a listing of each segment, module, lesson, and lesson element in a curriculum, or an equivalent... continuing qualification curriculum. First Look is conducted during an AQP continuing qualification cycle to...

9 CFR 381.150 - Requirements for the production of fully cooked poultry products and partially cooked poultry...

Code of Federal Regulations, 2011 CFR

2011-01-01

... standards: (1) Lethality. A 7-log10 reduction of Salmonella or an alternative lethality that achieves an equivalent probability that no viable Salmonella organisms remain in the finished product, as well as the...

Affordance Equivalences in Robotics: A Formalism

PubMed Central

Andries, Mihai; Chavez-Garcia, Ricardo Omar; Chatila, Raja; Giusti, Alessandro; Gambardella, Luca Maria

2018-01-01

Automatic knowledge grounding is still an open problem in cognitive robotics. Recent research in developmental robotics suggests that a robot's interaction with its environment is a valuable source for collecting such knowledge about the effects of robot's actions. A useful concept for this process is that of an affordance, defined as a relationship between an actor, an action performed by this actor, an object on which the action is performed, and the resulting effect. This paper proposes a formalism for defining and identifying affordance equivalence. By comparing the elements of two affordances, we can identify equivalences between affordances, and thus acquire grounded knowledge for the robot. This is useful when changes occur in the set of actions or objects available to the robot, allowing to find alternative paths to reach goals. In the experimental validation phase we verify if the recorded interaction data is coherent with the identified affordance equivalences. This is done by querying a Bayesian Network that serves as container for the collected interaction data, and verifying that both affordances considered equivalent yield the same effect with a high probability. PMID:29937724

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

Breton, D.; /Orsay, LAL; Delagnes, E.

There is a considerable interest to develop new time-of-flight detectors using, for example, micro-channel-plate photodetectors (MCP-PMTs). The question we pose in this paper is if new waveform digitizer ASICs, such as the WaveCatcher and TARGET, operating with a sampling rate of 2-3 GSa/s can compete with 1GHz BW CFD/TDC/ADC electronics. We have performed a series of measurements with these waveform digitizers coupled to MCP-PMTs operating at low gain and with a signal equivalent to {approx}40 photoelectrons. The tests were done with a laser diode on detectors operating under the same condition used previously in SLAC and Fermilab beam tests. Ourmore » test results indicate that one can achieve similar resolution with both methods. Although the commercial CFD-based electronics does exist and performs very well, it is difficult to implement on a very large scale, and therefore the custom electronics is needed. In addition, the analog delay line requirement makes it very difficult to incorporate CFD discriminators in ASIC designs.« less

Lean, premixed, prevaporized fuel combustor conceptual design study

NASA Technical Reports Server (NTRS)

Fiorentino, A. J.; Greene, W.; Kim, J.

1979-01-01

Four combustor concepts, designed for the energy efficient engine, utilize variable geometry or other flow modulation techniques to control the equivalence ratio of the initial burning zone. Lean conditions are maintained at high power to control oxides of nitrogen while near stoichometric conditions are maintained at low power for low CO and THC emissions. Each concept was analyzed and ranked for its potential in meeting the goals of the program. Although the primary goal of the program is a low level of nitric oxide emissions at stratospheric cruise conditions, both the ground level EPA emission standards and combustor performance and operational requirements typical of advanced subsonic aircraft engines are retained as goals as well. Based on the analytical projections made, two of the concepts offer the potential of achieving the emission goals; however, the projected operational characteristics and reliability of any concept to perform satisfactorily over an entire aircraft flight envelope would require extensive experimental substantiation before engine adaptation can be considered.

Multimodal registration via spatial-context mutual information.

PubMed

Yi, Zhao; Soatto, Stefano

2011-01-01

We propose a method to efficiently compute mutual information between high-dimensional distributions of image patches. This in turn is used to perform accurate registration of images captured under different modalities, while exploiting their local structure otherwise missed in traditional mutual information definition. We achieve this by organizing the space of image patches into orbits under the action of Euclidean transformations of the image plane, and estimating the modes of a distribution in such an orbit space using affinity propagation. This way, large collections of patches that are equivalent up to translations and rotations are mapped to the same representative, or "dictionary element". We then show analytically that computing mutual information for a joint distribution in this space reduces to computing mutual information between the (scalar) label maps, and between the transformations mapping each patch into its closest dictionary element. We show that our approach improves registration performance compared with the state of the art in multimodal registration, using both synthetic and real images with quantitative ground truth.

A CSMP commutation model for design study of a brushless dc motor power conditioner for a cruise missile fin control actuator

NASA Astrophysics Data System (ADS)

MacMillan, P. N.

1985-06-01

Recent improvements in rare earth magnets have made it possible to construct strong, lightweight, high horsepower dc motors. This has occasioned a reassessment of electromechanical actuators as alternatives to comparable pneumatic and hydraulic systems for use as flight control actuators for tactical missiles. A dynamic equivalent circuit model for the analysis of a small four pole brushless dc motor fed by a transistorized power conditioner utilizing high speed switching power transistors as final elements is presented. The influence of electronic commutation on instantaneous dynamic motor performance is particularly demonstrated and good correlation between computer simulation and typical experimentally obtained performance data is achieved. The model is implemented in CSMP language and features more accurate air gap flux representation over previous work. Hall effect sensor rotor position feedback is simulated. Both constant and variable air gap flux is modeled and the variable flux model treats the flux as a fundamental and one harmonic.

Accurate, reliable prototype earth horizon sensor head

NASA Technical Reports Server (NTRS)

Schwarz, F.; Cohen, H.

1973-01-01

The design and performance is described of an accurate and reliable prototype earth sensor head (ARPESH). The ARPESH employs a detection logic 'locator' concept and horizon sensor mechanization which should lead to high accuracy horizon sensing that is minimally degraded by spatial or temporal variations in sensing attitude from a satellite in orbit around the earth at altitudes in the 500 km environ 1,2. An accuracy of horizon location to within 0.7 km has been predicted, independent of meteorological conditions. This corresponds to an error of 0.015 deg-at 500 km altitude. Laboratory evaluation of the sensor indicates that this accuracy is achieved. First, the basic operating principles of ARPESH are described; next, detailed design and construction data is presented and then performance of the sensor under laboratory conditions in which the sensor is installed in a simulator that permits it to scan over a blackbody source against background representing the earth space interface for various equivalent plant temperatures.

Fast modeling of flux trapping cascaded explosively driven magnetic flux compression generators.

PubMed

Wang, Yuwei; Zhang, Jiande; Chen, Dongqun; Cao, Shengguang; Li, Da; Liu, Chebo

2013-01-01

To predict the performance of flux trapping cascaded flux compression generators, a calculation model based on an equivalent circuit is investigated. The system circuit is analyzed according to its operation characteristics in different steps. Flux conservation coefficients are added to the driving terms of circuit differential equations to account for intrinsic flux losses. To calculate the currents in the circuit by solving the circuit equations, a simple zero-dimensional model is used to calculate the time-varying inductance and dc resistance of the generator. Then a fast computer code is programmed based on this calculation model. As an example, a two-staged flux trapping generator is simulated by using this computer code. Good agreements are achieved by comparing the simulation results with the measurements. Furthermore, it is obvious that this fast calculation model can be easily applied to predict performances of other flux trapping cascaded flux compression generators with complex structures such as conical stator or conical armature sections and so on for design purpose.

Marine floating microbial fuel cell involving aerobic biofilm on stainless steel cathodes.

PubMed

Erable, B; Lacroix, R; Etcheverry, L; Féron, D; Delia, M L; Bergel, A

2013-08-01

Here is presented a new design of a floating marine MFC in which the inter-electrode space is constant. This design allows the generation of stable current for applications in environments where the water column is large or subject to fluctuations such as tidal effects. The operation of the first prototype was validated by running a continuous test campaign for 6months. Performance in terms of electricity generation was already equivalent to what is conventionally reported in the literature with basic benthic MFCs despite the identification of a large internal resistance in the proposed design of the floating system. This high internal resistance is mainly explained by poor positioning of the membrane separating the anode compartment from the open seawater. The future objectives are to achieve more consistent performance and a second-generation prototype is now being developed, mainly incorporating a modification of the separator position and a stainless steel biocathode with a large bioavailable surface. Copyright © 2013 Elsevier Ltd. All rights reserved.

Voltage-controlled IPMC actuators for accommodating intra-ocular lens systems

NASA Astrophysics Data System (ADS)

Horiuchi, Tetsuya; Mihashi, Toshifumi; Fujikado, Takashi; Oshika, Tetsuro; Asaka, Kinji

2017-04-01

An ion polymer-metal composite (IPMC) actuator has unique performance characteristics that were applied in this study for use within the eye. Cataracts are a common eye disease causing clouding of the lens. To treat cataracts, surgeons replace clouded lenses with intraocular lenses (IOLs). However, patients who receive this treatment must still wear reading glasses for tasks requiring close-up vision. We suggest a new voltage-controlled accommodating IOL consisting of an IPMC actuator to change the lens’ focus. We examined the relationship between the displacement performance of an IPMC actuator and the accommodating range of the IOL using in vitro experiments. We show that this system has an accommodating range of approximately 1.15 D under an applied voltage of ±1.2 V. By Lagrange interpolation, we estimate that with an IPMC actuator displacement of 0.14 mm, we can achieve a refractive power of 4 D, which is equivalent to the accommodating range of a 40 year old person.

Solar thermal vacuum tests of Magellan spacecraft

NASA Technical Reports Server (NTRS)

Neuman, James C.

1990-01-01

The Magellen solar/thermal/vacuum test involved a number of unique requirements and approaches. Because of the need to operate in orbit around Venus, the solar intensity requirement ranged up to 2.3 suns or Earth equivalent solar constants. Extensive modification to the solar simulator portion of the test facility were required to achieve this solar intensity. Venus albedo and infrared emission were simulated using temperature controlled movable louver panels to allow the spacecraft to view either a selectable temperature black heat source with closed louvers, or the chamber coldwall behind open louvers. The test conditions included widely varying solar intensities, multiple sun angles, alternate hardware configurations, steady state and transient cases, and cruise and orbital power profiles. Margin testing was also performed, wherein supplemental heaters were mounted to internal thermal blankets to verify spacecraft performance at higher than expected temperatures. The test was successful, uncovering some spacecraft anomalies and verifying the thermal design. The test support equipment experienced some anomalous behavior and a significant failure during the test.

Performance of a High-Concentration Erbium-Doped Fiber Amplifier with 100 nm Amplification Bandwidth

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

Hajireza, P.; Shahabuddin, N. S.; Abbasi-Zargaleh, S.

2010-07-07

Increasing demand for higher bandwidth has driven the need for higher Wavelength Division Multiplexing (WDM) channels. One of the requirements to achieve this is a broadband amplifier. This paper reports the performance of a broadband, compact, high-concentration and silica-based erbium-doped fiber amplifier. The amplifier optimized to a 2.15 m long erbium-doped fiber with erbium ion concentration of 2000 ppm. The gain spectrum of the amplifier has a measured amplification bandwidth of 100 nm using a 980 nm laser diode with power of 150 mW. This silica-based EDFA shows lower noise figure, higher gain and wider bandwidth in shorter wavelengths comparedmore » to Bismuth-based EDFA with higher erbium ion concentration of 3250 ppm at equivalent EDF length. The silica-based EDF shows peak gain at 22 dB and amplification bandwidth between 1520 nm and 1620 nm. The lowest noise figure is 5 dB. The gain is further improved with the implementation of enhanced EDFA configurations.« less

IMPROVEMENTS IN THE THERMAL NEUTRON CALIBRATION UNIT, TNF2, AT LNMRI/IRD.

PubMed

Astuto, A; Fernandes, S S; Patrão, K C S; Fonseca, E S; Pereira, W W; Lopes, R T

2018-02-21

The standard thermal neutron flux unit, TNF2, in the Brazilian National Ionizing Radiation Metrology Laboratory was rebuilt. Fluence is still achieved by moderating of four 241Am-Be sources with 0.6 TBq each. The facility was again simulated and redesigned with graphite core and paraffin added graphite blocks surrounding it. Simulations using the MCNPX code on different geometric arrangements of moderator materials and neutron sources were performed. The resulting neutron fluence quality in terms of intensity, spectrum and cadmium ratio was evaluated. After this step, the system was assembled based on the results obtained from the simulations and measurements were performed with equipment existing in LNMRI/IRD and by simulated equipment. This work focuses on the characterization of a central chamber point and external points around the TNF2 in terms of neutron spectrum, fluence and ambient dose equivalent, H*(10). This system was validated with spectra measurements, fluence and H*(10) to ensure traceability.

Realization of the medium and high vacuum primary standard in CENAM, Mexico

NASA Astrophysics Data System (ADS)

Torres-Guzman, J. C.; Santander, L. A.; Jousten, K.

2005-12-01

A medium and high vacuum primary standard, based on the static expansion method, has been set up at Centro Nacional de Metrología (CENAM), Mexico. This system has four volumes and covers a measuring range of 1 × 10-5 Pa to 1 × 103 Pa of absolute pressure. As part of its realization, a characterization was performed, which included volume calibrations, several tests and a bilateral key comparison. To determine the expansion ratios, two methods were applied: the gravimetric method and the method with a linearized spinning rotor gauge. The outgassing ratios for the whole system were also determined. A comparison was performed with Physikalisch-Technische Bundesanstalt (comparison SIM-Euromet.M.P-BK3). By means of this comparison, a link has been achieved with the Euromet comparison (Euromet.M.P-K1.b). As a result, it is concluded that the value obtained at CENAM is equivalent to the Euromet reference value, and therefore the design, construction and operation of CENAM's SEE-1 vacuum primary standard were successful.

An Auditory-Masking-Threshold-Based Noise Suppression Algorithm GMMSE-AMT[ERB] for Listeners with Sensorineural Hearing Loss

NASA Astrophysics Data System (ADS)

Natarajan, Ajay; Hansen, John H. L.; Arehart, Kathryn Hoberg; Rossi-Katz, Jessica

2005-12-01

This study describes a new noise suppression scheme for hearing aid applications based on the auditory masking threshold (AMT) in conjunction with a modified generalized minimum mean square error estimator (GMMSE) for individual subjects with hearing loss. The representation of cochlear frequency resolution is achieved in terms of auditory filter equivalent rectangular bandwidths (ERBs). Estimation of AMT and spreading functions for masking are implemented in two ways: with normal auditory thresholds and normal auditory filter bandwidths (GMMSE-AMT[ERB]-NH) and with elevated thresholds and broader auditory filters characteristic of cochlear hearing loss (GMMSE-AMT[ERB]-HI). Evaluation is performed using speech corpora with objective quality measures (segmental SNR, Itakura-Saito), along with formal listener evaluations of speech quality rating and intelligibility. While no measurable changes in intelligibility occurred, evaluations showed quality improvement with both algorithm implementations. However, the customized formulation based on individual hearing losses was similar in performance to the formulation based on the normal auditory system.

Economic and policy implications of the cumulative carbon budget

NASA Astrophysics Data System (ADS)

Allen, M. R.; Otto, F. E. L.; Otto, A.; Hepburn, C.

2014-12-01

The importance of cumulative carbon emissions in determining long-term risks of climate change presents considerable challenges to policy makers. The traditional notion of "total CO2-equivalent emissions", which forms the backbone of agreements such as the Kyoto Protocol and the European Emissions Trading System, is fundamentally flawed. Measures to reduce short-lived climate pollutants benefit the current generation, while measures to reduce long-lived climate pollutants benefit future generations, so there is no sense in which they can ever be considered equivalent. Debates over the correct metric used to compute CO2-equivalence are thus entirely moot: both long-lived and short-lived emissions will need to be addressed if all generations are to be protected from dangerous climate change. As far as long-lived climate pollutants are concerned, the latest IPCC report highlights the overwhelming importance of carbon capture and storage in determining the cost of meeting the goal of limiting anthropogenic warming to two degrees. We will show that this importance arises directly from the cumulative carbon budget and the role of CCS as the technology of last resort before economic activity needs to be restricted to meet ambitious climate targets. It highlights the need to increase the rate of CCS deployment by orders of magnitude if the option of avoiding two degrees is to be retained. The difficulty of achieving this speed of deployment through conventional incentives and carbon-pricing mechanisms suggests a need for a much more direct mandatory approach. Despite their theoretical economic inefficiency, the success of recent regulatory measures in achieving greenhouse gas emissions reductions in jurisdictions such as the United States suggests an extension of the regulatory approach could be a more effective and politically acceptable means of achieving adequately rapid CCS deployment than conventional carbon taxes or cap-and-trade systems.

The Effect of a State Department of Education Teacher Mentor Initiative on Science Achievement

NASA Astrophysics Data System (ADS)

Pruitt, Stephen L.

This study analyzed a state department of education's ability to have actual influence over the improvement of science achievement and proficiency by having direct relationships with science teachers in Georgia's lowest performing schools. The study employed a mixed ANOVA analysis of the mean scale scores and proficiency rates of the science portion of the Georgia High School Graduation Test (GHSGT) for the years 2004 through 2007 to determine if the intervention by the Science Mentor Program (SMP) had significant effect on the science achievement and proficiency within the cohort of schools, as compared to a set of schools receiving no intervention, on various subgroups within the schools, and on various levels of intervention within the SMP. All data used in this study are available to the public through the Georgia Department of Education (GaDOE). SMP schools were selected based on their level of intervention for three consecutive years. Non-SMP schools were selected based on demographic similarities in economically disadvantaged, white, African-American, and students with disabilities to ensure a match of pairings for analyses. The results of this study showed significant improvement of scale scores and proficiency rates between 2004 and 2007. The study showed significant increases in all schools regardless of treatment. The study also showed significant differences in performance within the subgroups. Males, white, non-Economically Disadvantaged, and regular education students were all found to have significantly better performance in both achievement and proficiency rate. Economically Disadvantaged students were found to have a significant difference with regard to treatment groups. There was a significant difference between the mean scale score and proficiency rates of Economically Disadvantaged students in schools receiving high-intervention and schools receiving no-intervention. Further analysis showed that the only significant difference was in 2004, the year prior to implementation. Results indicate while the high-intervention schools did perform lower over all four years, they were not significantly different during the time of treatment indicating high-intervention schools performed at levels equivalent to schools receiving no-intervention. This study provided evidence of the success of a specific intervention by a state education agency to improve science education for the practicing teacher and its role in improving student science achievement. It will be used by policymakers to determine future activities and potential funding of other such programs. This also has a potential for national use as it is the only program of this nature operated by a department of education in the country.

VCSEL based Faraday rotation spectroscopy at 762nm for battery powered trace molecular oxygen detection

NASA Astrophysics Data System (ADS)

So, Stephen; Wysocki, Gerard

2010-02-01

Faraday Rotation Spectroscopy (FRS) is a polarization based spectroscopic technique which can provide higher sensitivity concentration measurements of paramagnetic gases and free radicals than direct absorption spectroscopic techniques. We have developed sensor systems which require only 0.2W to perform TDLAS (tunable diode laser absorption spectroscopy), and can additionally be quickly duty cycled, enabling operation in wireless sensor networks of laser-based trace gas sensors We adapted our integrated TDLAS electronics to perform FRS in a compact and more sensitive system for quantification of molecular oxygen (O2) using a 762.3nm VCSEL in the A band. Using an AC magnetic field, we demonstrate detector noise dominated performance, achieving 2.1×10-6/Hz1/2 equivalent detectable fractional absorption and a minimum detection limit of 462 ppmv O2 in 1 second in a 15cm path. At longer paths and integration times, such a sensor will enable oxygen measurements at biotic respiration levels (<1ppmv) to measure CO2 - O2 exchange for mapping natural exchange of greenhouse gases. Potential improvement of detection limits by increasing various system performance parameters is described.

Tracking performance with two breathing oxygen concentrations after high altitude rapid decompression

NASA Technical Reports Server (NTRS)

Nesthus, Thomas E.; Schiflett, Samuel G.; Oakley, Carolyn J.

1992-01-01

Current military aircraft Liquid Oxygen (LOX) systems supply 99.5 pct. gaseous Aviator's Breathing Oxygen (ABO) to aircrew. Newer Molecular Sieve Oxygen Generation Systems (MSOGS) supply breathing gas concentration of 93 to 95 pct. O2. The margin is compared of hypoxia protection afforded by ABO and MSOGS breathing gas after a 5 psi differential rapid decompression (RD) in a hypobaric research chamber. The barometric pressures equivalent to the altitudes of 46000, 52000, 56000, and 60000 ft were achieved from respective base altitudes in 1 to 1.5 s decompressions. During each exposure, subjects remained at the simulated peak altitude breathing either 100 or 94 pct. O2 with positive pressure for 60 s, followed by a rapid descent to 40000 ft. Subjects used the Tactical Life Support System (TLSS) for high altitude protection. Subcritical tracking task performance on the Performance Evaluation Device (PED) provided psychomotor test measures. Overall tracking task performance results showed no differences between the MSOGS breathing O2 concentration of 94 pct. and ABO. Significance RMS error differences were found between the ground level and base altitude trials compared to peak altitude trials. The high positive breathing pressures occurring at the peak altitudes explained the differences.

NGST fine guidance sensor

NASA Astrophysics Data System (ADS)

Rowlands, Neil; Hutchings, John; Murowinski, Richard G.; Alexander, Russ

2003-03-01

Instrumentation for the Next Generation Space Telescope (NGST) is currently in the Phase A definition stage. We have developed a concept for the NGST Fine Guidance Sensor or FGS. The FGS is a detector array based imager which resides in the NGST focal plane. We report here on tradeoff studies aimed at defining an overall configuration of the FGS which will meet the performance and interface requirements. A key performance requirement is a noise equivalent angle of 3 milli-arcseconds to be achieved with 95% probability for any pointing of the observatory in the celestial sphere. A key interface requirement is compatibility with the architecture of the Integrated Science Instrument Module (ISIM). The concept developed consists of two independent and redundant FGS modules, each with a 4' x 2' field of view covered by two 2048 x 2048 infrared detector arrays, providing 60 milli-arcsecond sampling. Performance modeling supporting the choice of this architecture and the trade space considered is presented. Each module has a set of readout electronics which perform star detection, pixel-by-pixel correction, and in fine guiding mode, centroid calculation. These readout electronics communicate with the ISIM Command &Data Handling Units where the FGS control software is based. Rationale for this choice of architecture is also presented.

An Optoelectronic Equivalent Narrowband Filter for High Resolution Optical Spectrum Analysis

PubMed Central

Feng, Kunpeng; Cui, Jiwen; Dang, Hong; Wu, Weidong; Sun, Xun; Jiang, Xuelin; Tan, Jiubin

2017-01-01

To achieve a narrow bandwidth optical filter with a wide swept range for new generation optical spectrum analysis (OSA) of high performance optical sensors, an optoelectronic equivalent narrowband filter (OENF) was investigated and a swept optical filter with bandwidth of several MHz and sweep range of several tens of nanometers was built using electric filters and a sweep laser as local oscillator (LO). The principle of OENF is introduced and analysis of the OENF system is presented. Two electric filters are optimized to be RBW filters for high and medium spectral resolution applications. Both simulations and experiments are conducted to verify the OENF principle and the results show that the power uncertainty is less than 1.2% and the spectral resolution can reach 6 MHz. Then, a real-time wavelength calibration system consisting of a HCN gas cell and Fabry–Pérot etalon is proposed to guarantee a wavelength accuracy of ±0.4 pm in the C-band and to reduce the influence of phase noise and nonlinear velocity of the LO sweep. Finally, OSA experiments on actual spectra of various optical sensors are conducted using the OENF system. These experimental results indicate that OENF system has an excellent capacity for the analysis of fine spectrum structures. PMID:28208624

Automatic segmentation method of pelvic floor levator hiatus in ultrasound using a self-normalizing neural network

PubMed Central

Dietz, Hans Peter; D’hooge, Jan; Barratt, Dean; Deprest, Jan

2018-01-01

Abstract. Segmentation of the levator hiatus in ultrasound allows the extraction of biometrics, which are of importance for pelvic floor disorder assessment. We present a fully automatic method using a convolutional neural network (CNN) to outline the levator hiatus in a two-dimensional image extracted from a three-dimensional ultrasound volume. In particular, our method uses a recently developed scaled exponential linear unit (SELU) as a nonlinear self-normalizing activation function, which for the first time has been applied in medical imaging with CNN. SELU has important advantages such as being parameter-free and mini-batch independent, which may help to overcome memory constraints during training. A dataset with 91 images from 35 patients during Valsalva, contraction, and rest, all labeled by three operators, is used for training and evaluation in a leave-one-patient-out cross validation. Results show a median Dice similarity coefficient of 0.90 with an interquartile range of 0.08, with equivalent performance to the three operators (with a Williams’ index of 1.03), and outperforming a U-Net architecture without the need for batch normalization. We conclude that the proposed fully automatic method achieved equivalent accuracy in segmenting the pelvic floor levator hiatus compared to a previous semiautomatic approach. PMID:29340289

Automatic segmentation method of pelvic floor levator hiatus in ultrasound using a self-normalizing neural network.

PubMed

Bonmati, Ester; Hu, Yipeng; Sindhwani, Nikhil; Dietz, Hans Peter; D'hooge, Jan; Barratt, Dean; Deprest, Jan; Vercauteren, Tom

2018-04-01

Segmentation of the levator hiatus in ultrasound allows the extraction of biometrics, which are of importance for pelvic floor disorder assessment. We present a fully automatic method using a convolutional neural network (CNN) to outline the levator hiatus in a two-dimensional image extracted from a three-dimensional ultrasound volume. In particular, our method uses a recently developed scaled exponential linear unit (SELU) as a nonlinear self-normalizing activation function, which for the first time has been applied in medical imaging with CNN. SELU has important advantages such as being parameter-free and mini-batch independent, which may help to overcome memory constraints during training. A dataset with 91 images from 35 patients during Valsalva, contraction, and rest, all labeled by three operators, is used for training and evaluation in a leave-one-patient-out cross validation. Results show a median Dice similarity coefficient of 0.90 with an interquartile range of 0.08, with equivalent performance to the three operators (with a Williams' index of 1.03), and outperforming a U-Net architecture without the need for batch normalization. We conclude that the proposed fully automatic method achieved equivalent accuracy in segmenting the pelvic floor levator hiatus compared to a previous semiautomatic approach.

[Optimizing staff radiation protection in radiology by minimizing the effective dose].

PubMed

von Boetticher, H; Lachmund, J; Hoffmann, W; Luska, G

2006-03-01

In the present study the optimization of radiation protection devices is achieved by minimizing the effective dose of the staff members since the stochastic radiation effects correlate to the effective dose. Radiation exposure dosimetry was performed with TLD measurements using one Alderson Phantom in the patient position and a second phantom in the typical position of the personnel. Various types of protective clothing as well as fixed shields were considered in the calculations. It was shown that the doses of the unshielded organs (thyroid, parts of the active bone marrow) contribute significantly to the effective dose of the staff. Therefore, there is no linear relationship between the shielding factors for protective garments and the effective dose. An additional thyroid protection collar reduces the effective dose by a factor of 1.7 - 3.0. X-ray protective clothing with a 0.35 mm lead equivalent and an additional thyroid protection collar provides better protection against radiation than an apron with a 0.5 mm lead equivalent but no collar. The use of thyroid protection collars is an effective preventive measure against exceeding occupational organ dose limits, and a thyroid shield also considerably reduces the effective dose. Therefore, thyroid protection collars should be a required component of anti-X protection.

An Optoelectronic Equivalent Narrowband Filter for High Resolution Optical Spectrum Analysis.

PubMed

Feng, Kunpeng; Cui, Jiwen; Dang, Hong; Wu, Weidong; Sun, Xun; Jiang, Xuelin; Tan, Jiubin

2017-02-10

To achieve a narrow bandwidth optical filter with a wide swept range for new generation optical spectrum analysis (OSA) of high performance optical sensors, an optoelectronic equivalent narrowband filter (OENF) was investigated and a swept optical filter with bandwidth of several MHz and sweep range of several tens of nanometers was built using electric filters and a sweep laser as local oscillator (LO). The principle of OENF is introduced and analysis of the OENF system is presented. Two electric filters are optimized to be RBW filters for high and medium spectral resolution applications. Both simulations and experiments are conducted to verify the OENF principle and the results show that the power uncertainty is less than 1.2% and the spectral resolution can reach 6 MHz. Then, a real-time wavelength calibration system consisting of a HCN gas cell and Fabry-Pérot etalon is proposed to guarantee a wavelength accuracy of ±0.4 pm in the C-band and to reduce the influence of phase noise and nonlinear velocity of the LO sweep. Finally, OSA experiments on actual spectra of various optical sensors are conducted using the OENF system. These experimental results indicate that OENF system has an excellent capacity for the analysis of fine spectrum structures.

40 CFR Table F-1 to Subpart F of... - Performance Specifications for PM2.5 Class II Equivalent Samplers

Code of Federal Regulations, 2011 CFR

2011-07-01

... specified in the post-loading evaluation test (§ 53.62, § 53.63, or § 53.64). § 53.66 Volatility Test... Equivalent Samplers Performance test Specifications Acceptance criteria § 53.62 Full Wind Tunnel Evaluation...: 95% ≤ Rc ≤ 105%. § 53.63 Wind Tunnel Inlet Aspiration Test Liquid VOAG produced aerosol at 2 km/hr...

40 CFR Table F-1 to Subpart F of... - Performance Specifications for PM2.5 Class II Equivalent Samplers

Code of Federal Regulations, 2010 CFR

2010-07-01

... specified in the post-loading evaluation test (§ 53.62, § 53.63, or § 53.64). § 53.66 Volatility Test... Equivalent Samplers Performance test Specifications Acceptance criteria § 53.62 Full Wind Tunnel Evaluation...: 95% ≤ Rc ≤ 105%. § 53.63 Wind Tunnel Inlet Aspiration Test Liquid VOAG produced aerosol at 2 km/hr...

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

Dowdy, M.; Burke, A.; Schneider, H.

Fuel economy, exhaust emissions, multifuel capability, advanced materials and cost/manufacturability for both conventional and advanced alternative power systems were assessed. To insure valid comparisons of vehicles with alternative power systems, the concept of an Otto-Engine-Equivalent (OEE) vehicle was utilized. Each engine type was sized to provide equivalent vehicle performance. Sensitivity to different performance criteria was evaluated. Fuel economy projections are made for each engine type considering both the legislated emission standards and possible future emissions requirements.

A new method for testing the scale-factor performance of fiber optical gyroscope

NASA Astrophysics Data System (ADS)

Zhao, Zhengxin; Yu, Haicheng; Li, Jing; Li, Chao; Shi, Haiyang; Zhang, Bingxin

2015-10-01

Fiber optical gyro (FOG) is a kind of solid-state optical gyroscope with good environmental adaptability, which has been widely used in national defense, aviation, aerospace and other civilian areas. In some applications, FOG will experience environmental conditions such as vacuum, radiation, vibration and so on, and the scale-factor performance is concerned as an important accuracy indicator. However, the scale-factor performance of FOG under these environmental conditions is difficult to test using conventional methods, as the turntable can't work under these environmental conditions. According to the phenomenon that the physical effects of FOG produced by the sawtooth voltage signal under static conditions is consistent with the physical effects of FOG produced by a turntable in uniform rotation, a new method for the scale-factor performance test of FOG without turntable is proposed in this paper. In this method, the test system of the scale-factor performance is constituted by an external operational amplifier circuit and a FOG which the modulation signal and Y waveguied are disconnected. The external operational amplifier circuit is used to superimpose the externally generated sawtooth voltage signal and the modulation signal of FOG, and to exert the superimposed signal on the Y waveguide of the FOG. The test system can produce different equivalent angular velocities by changing the cycle of the sawtooth signal in the scale-factor performance test. In this paper, the system model of FOG superimposed with an externally generated sawtooth is analyzed, and a conclusion that the effect of the equivalent input angular velocity produced by the sawtooth voltage signal is consistent with the effect of input angular velocity produced by the turntable is obtained. The relationship between the equivalent angular velocity and the parameters such as sawtooth cycle and so on is presented, and the correction method for the equivalent angular velocity is also presented by analyzing the influence of each parameter error on the equivalent angular velocity. A comparative experiment of the method proposed in this paper and the method of turntable calibration was conducted, and the scale-factor performance test results of the same FOG using the two methods were consistent. Using the method proposed in this paper to test the scale-factor performance of FOG, the input angular velocity is the equivalent effect produced by a sawtooth voltage signal, and there is no need to use a turntable to produce mechanical rotation, so this method can be used to test the performance of FOG at the ambient conditions which turntable can not work.

Grades, Student Satisfaction and Retention in Online and Face-to-Face Introductory Psychology Units: A Test of Equivalency Theory.

PubMed

Garratt-Reed, David; Roberts, Lynne D; Heritage, Brody

2016-01-01

There has been a recent rapid growth in the number of psychology courses offered online through institutions of higher education. The American Psychological Association has highlighted the importance of ensuring the effectiveness of online psychology courses (Halonen et al., 2013). Despite this, there have been inconsistent findings regarding student grades, satisfaction, and retention in online psychology units. Equivalency Theory (Simonson, 1999; Simonson et al., 1999) posits that online and classroom-based learners will attain equivalent learning outcomes when equivalent learning experiences are provided. We present a study of an online introductory psychology unit designed to provide equivalent learning experiences to the pre-existing face-to-face version of the unit. Using quasi-experimental methods, academic performance, student feedback, and retention data from 866 Australian undergraduate psychology students were examined to assess whether the online unit developed to provide equivalent learning experiences produced comparable outcomes to the 'traditional' unit delivered face-to-face. Student grades did not significantly differ between modes of delivery, except for a group-work based assessment where online students performed more poorly. Student satisfaction was generally high in both modes of the unit, with group-work the key source of dissatisfaction in the online unit. The results provide partial support for Equivalency Theory. The group-work based assessment did not provide an equivalent learning experience for students in the online unit highlighting the need for further research to determine effective methods of engaging students in online group activities. Consistent with previous research, retention rates were significantly lower in the online unit, indicating the need to develop effective strategies to increase online retention rates. While this study demonstrates successes in presenting students with an equivalent learning experience, we recommend that future research investigate means of successfully facilitating collaborative group-work assessment, and to explore contributing factors to actual student retention in online units beyond that of non-equivalent learning experiences.

Grades, Student Satisfaction and Retention in Online and Face-to-Face Introductory Psychology Units: A Test of Equivalency Theory

PubMed Central

Garratt-Reed, David; Roberts, Lynne D.; Heritage, Brody

2016-01-01

There has been a recent rapid growth in the number of psychology courses offered online through institutions of higher education. The American Psychological Association has highlighted the importance of ensuring the effectiveness of online psychology courses (Halonen et al., 2013). Despite this, there have been inconsistent findings regarding student grades, satisfaction, and retention in online psychology units. Equivalency Theory (Simonson, 1999; Simonson et al., 1999) posits that online and classroom-based learners will attain equivalent learning outcomes when equivalent learning experiences are provided. We present a study of an online introductory psychology unit designed to provide equivalent learning experiences to the pre-existing face-to-face version of the unit. Using quasi-experimental methods, academic performance, student feedback, and retention data from 866 Australian undergraduate psychology students were examined to assess whether the online unit developed to provide equivalent learning experiences produced comparable outcomes to the ‘traditional’ unit delivered face-to-face. Student grades did not significantly differ between modes of delivery, except for a group-work based assessment where online students performed more poorly. Student satisfaction was generally high in both modes of the unit, with group-work the key source of dissatisfaction in the online unit. The results provide partial support for Equivalency Theory. The group-work based assessment did not provide an equivalent learning experience for students in the online unit highlighting the need for further research to determine effective methods of engaging students in online group activities. Consistent with previous research, retention rates were significantly lower in the online unit, indicating the need to develop effective strategies to increase online retention rates. While this study demonstrates successes in presenting students with an equivalent learning experience, we recommend that future research investigate means of successfully facilitating collaborative group-work assessment, and to explore contributing factors to actual student retention in online units beyond that of non-equivalent learning experiences. PMID:27242587

Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication

PubMed Central

Williamson, A; Feyer, A.

2000-01-01

OBJECTIVES—To compare the relative effects on performance of sleep deprivation and alcohol.
METHODS—Performance effects were studied in the same subjects over a period of 28 hours of sleep deprivation and after measured doses of alcohol up to about 0.1% blood alcohol concentration (BAC). There were 39 subjects, 30 employees from the transport industry and nine from the army.
RESULTS—After 17-19 hours without sleep, corresponding to 2230 and 0100, performance on some tests was equivalent or worse than that at a BAC of 0.05%. Response speeds were up to 50% slower for some tests and accuracy measures were significantly poorer than at this level of alcohol. After longer periods without sleep, performance reached levels equivalent to the maximum alcohol dose given to subjects (BAC of 0.1%).
CONCLUSIONS—These findings reinforce the evidence that the fatigue of sleep deprivation is an important factor likely to compromise performance of speed and accuracy of the kind needed for safety on the road and in other industrial settings.


Keywords: sleep deprivation; performance; alcohol PMID:10984335

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

Grant, Alexander M.; Deller, Timothy W.; Maramraju, Sri Harsha

Purpose: The GE SIGNA PET/MR is a new whole body integrated time-of-flight (ToF)-PET/MR scanner from GE Healthcare. The system is capable of simultaneous PET and MR image acquisition with sub-400 ps coincidence time resolution. Simultaneous PET/MR holds great potential as a method of interrogating molecular, functional, and anatomical parameters in clinical disease in one study. Despite the complementary imaging capabilities of PET and MRI, their respective hardware tends to be incompatible due to mutual interference. In this work, the GE SIGNA PET/MR is evaluated in terms of PET performance and the potential effects of interference from MRI operation. Methods: Themore » NEMA NU 2-2012 protocol was followed to measure PET performance parameters including spatial resolution, noise equivalent count rate, sensitivity, accuracy, and image quality. Each of these tests was performed both with the MR subsystem idle and with continuous MR pulsing for the duration of the PET data acquisition. Most measurements were repeated at three separate test sites where the system is installed. Results: The scanner has achieved an average of 4.4, 4.1, and 5.3 mm full width at half maximum radial, tangential, and axial spatial resolutions, respectively, at 1 cm from the transaxial FOV center. The peak noise equivalent count rate (NECR) of 218 kcps and a scatter fraction of 43.6% are reached at an activity concentration of 17.8 kBq/ml. Sensitivity at the center position is 23.3 cps/kBq. The maximum relative slice count rate error below peak NECR was 3.3%, and the residual error from attenuation and scatter corrections was 3.6%. Continuous MR pulsing had either no effect or a minor effect on each measurement. Conclusions: Performance measurements of the ToF-PET whole body GE SIGNA PET/MR system indicate that it is a promising new simultaneous imaging platform.« less

Equivalence relations in individuals with language limitations and mental retardation.

PubMed Central

O'Donnell, Jennifer; Saunders, Kathryn J

2003-01-01

The study of equivalence relations exhibited by individuals with mental retardation and language limitations holds the promise of providing information of both theoretical and practical significance. We reviewed the equivalence literature with this population, defined in terms of subjects having moderate, severe, or profound mental retardation. The literature includes 55 such individuals, most of whom showed positive outcomes on equivalence tests. The results to date suggest that naming skills are not necessary for positive equivalence test outcomes. Thus far, however, relatively few subjects with minimal language have been studied. Moreover, we suggest that the scientific contributions of studies in this area would be enhanced with better documentation of language skills and other subject characteristics. With recent advances in laboratory procedures for establishing the baseline performances necessary for equivalence tests, this research area is poised for rapid growth. PMID:13677612

Optimizing MOS-gated thyristor using voltage-based equivalent circuit model for designing steep-subthreshold-slope PN-body-tied silicon-on-insulator FET

NASA Astrophysics Data System (ADS)

Ueda, Daiki; Takeuchi, Kiyoshi; Kobayashi, Masaharu; Hiramoto, Toshiro

2018-04-01

A new circuit model that provides a clear guide on designing a MOS-gated thyristor (MGT) is reported. MGT plays a significant role in achieving a steep subthreshold slope of a PN-body tied silicon-on-insulator (SOI) FET (PNBTFET), which is an SOI MOSFET merged with an MGT. The effects of design parameters on MGT and the proposed equivalent circuit model are examined to determine how to regulate the voltage response of MGT and how to suppress power dissipation. It is demonstrated that MGT with low threshold voltages, small hysteresis widths, and small power dissipation can be designed by tuning design parameters. The temperature dependence of MGT is also examined, and it is confirmed that hysteresis width decreases with the average threshold voltage kept nearly constant as temperature rises. The equivalent circuit model can be conveniently used to design low-power PNBTFET.

Weight propagation and equivalent horsepower for alternate-engined cars

NASA Technical Reports Server (NTRS)

Klose, G. J.; Kurtz, D. W.

1978-01-01

In order to evaluate properly the consequences of replacing conventional Otto-cycle engines with alternate power systems, comparisons must be carried out at the vehicle level with functionally equivalent cars. This paper presents the development and application of a procedure for establishing equivalent vehicles. A systematic weight propagation methodology, based on detailed weight breakdowns and influence factors, yields the vehicle weight impacts due to changes in engine weight and power. Performance-matching criteria, utilizing a vehicle simulation program, are then employed to establish Otto-engine-equivalent vehicles, whose characteristics can form the basis for alternative engine evaluations.

Equivalent electron fluence for space qualification of shallow junction heteroface GaAs solar cells

NASA Technical Reports Server (NTRS)

Wilson, J. W.; Stock, L. V.

1984-01-01

It is desirable to perform qualification tests prior to deployment of solar cells in space power applications. Such test procedures are complicated by the complex mixture of differing radiation components in space which are difficult to simulate in ground test facilities. Although it has been shown that an equivalent electron fluence ratio cannot be uniquely defined for monoenergetic proton exposure of GaAs shallow junction cells, an equivalent electron fluence test can be defined for common spectral components of protons found in space. Equivalent electron fluence levels for the geosynchronous environment are presented.

Phased Array Focusing for Acoustic Wireless Power Transfer.

PubMed

Tseng, Victor Farm-Guoo; Bedair, Sarah S; Lazarus, Nathan

2018-01-01

Wireless power transfer (WPT) through acoustic waves can achieve higher efficiencies than inductive coupling when the distance is above several times the transducer size. This paper demonstrates the use of ultrasonic phased arrays to focus power to receivers at arbitrary locations to increase the power transfer efficiency. Using a phased array consisting of 37 elements at a distance nearly 5 times the receiver transducer diameter, a factor of 2.6 increase in efficiency was achieved when compared to a case equivalent to a single large transducer with the same peak efficiency distance. The array has a total diameter of 7 cm, and transmits through air at 40 kHz to a 1.1-cm diameter receiver, achieving a peak overall efficiency of 4% at a distance of 5 cm. By adjusting the focal distance, the efficiency can also be maintained relatively constant at distances up to 9 cm. Numerical models were developed and shown to closely match the experimental energy transfer behavior; modeling results indicate that the efficiency can be further doubled by increasing the number of elements. For comparison, an inductive WPT system was also built with the diameters of the transmitting and receiving coils equivalent to the dimensions of the transmitting ultrasonic phased array and receiver transducer, and the acoustic WPT system achieved higher efficiencies than the inductive WPT system when the transmit-to-receive distance is above 5 cm. In addition, beam angle steering was demonstrated by using a simplified seven-element 1-D array, achieving power transfer less dependent on receiver placement.

Evaluation of gridded snow water equivalent and satellite snow cover products for mountain basins in a hydrologic model

USGS Publications Warehouse

Dressler, K.A.; Leavesley, G.H.; Bales, R.C.; Fassnacht, S.R.

2006-01-01

The USGS precipitation-runoff modelling system (PRMS) hydrologic model was used to evaluate experimental, gridded, 1 km2 snow-covered area (SCA) and snow water equivalent (SWE) products for two headwater basins within the Rio Grande (i.e. upper Rio Grande River basin) and Salt River (i.e. Black River basin) drainages in the southwestern USA. The SCA product was the fraction of each 1 km2 pixel covered by snow and was derived from NOAA advanced very high-resolution radiometer imagery. The SWE product was developed by multiplying the SCA product by SWE estimates interpolated from National Resources Conservation Service snow telemetry point measurements for a 6 year period (1995-2000). Measured SCA and SWE estimates were consistently lower than values estimated from temperature and precipitation within PRMS. The greatest differences occurred in the relatively complex terrain of the Rio Grande basin, as opposed to the relatively homogeneous terrain of the Black River basin, where differences were small. Differences between modelled and measured snow were different for the accumulation period versus the ablation period and had an elevational trend. Assimilating the measured snowfields into a version of PRMS calibrated to achieve water balance without assimilation led to reduced performance in estimating streamflow for the Rio Grande and increased performance in estimating streamflow for the Black River basin. Correcting the measured SCA and SWE for canopy effects improved simulations by adding snow mostly in the mid-to-high elevations, where satellite estimates of SCA are lower than model estimates. Copyright ?? 2006 John Wiley & Sons, Ltd.