APPLICATIONS OF A CONCEPTUAL MODEL (THE BIOLOGICAL CONDITION GRADIENT) TO DEFINE AQUATIC REFERENCE CONDITIONS

EPA Science Inventory

The United States Clean Water Act currently offers no definitions to interpret the Act's objective to "restore and maintain physical, chemical and biological integrity of the Nation's waters". Operative definitions, independent of differences in assessment methodologies, are nee...

Methods for Scaling Icing Test Conditions

NASA Technical Reports Server (NTRS)

Anderson, David N.

1995-01-01

This report presents the results of tests at NASA Lewis to evaluate several methods to establish suitable alternative test conditions when the test facility limits the model size or operating conditions. The first method was proposed by Olsen. It can be applied when full-size models are tested and all the desired test conditions except liquid-water content can be obtained in the facility. The other two methods discussed are: a modification of the French scaling law and the AEDC scaling method. Icing tests were made with cylinders at both reference and scaled conditions representing mixed and glaze ice in the NASA Lewis Icing Research Tunnel. Reference and scale ice shapes were compared to evaluate each method. The Olsen method was tested with liquid-water content varying from 1.3 to .8 g/m(exp3). Over this range, ice shapes produced using the Olsen method were unchanged. The modified French and AEDC methods produced scaled ice shapes which approximated the reference shapes when model size was reduced to half the reference size for the glaze-ice cases tested.

Strapdown system redundancy management flight demonstration. [vertical takeoff and landing aircraft

NASA Technical Reports Server (NTRS)

1978-01-01

The suitability of strapdown inertial systems in providing highly reliable short-term navigation for vertical take-off and landing (VTOL) aircraft operating in an intra-urban setting under all-weather conditions was assessed. A preliminary design configuration of a skewed sensor inertial reference system employing a redundancy management concept to achieve fail-operational, fail-operational performance, was developed.

A Review of Aircraft Cabin Conditioning for Operations in Australia

DTIC Science & Technology

1980-10-01

Balance for Thermal Comfort 17 3.4 Liquid Conditioned Garments 18 3.5 Environmental Requirements for Electronic Equipment 19 4. THERMAL LOAD- ON AIRCRAFT...References to these two aspects are given by Nunneley and James (1977). 3.3 Physiological Heat Balance for Thermal Comfort The heat balance for thermal ...

39 CFR 320.9 - Revocation or amendment of suspensions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... § 320.2 will curtail operations of particular carriers existing at the time of the revocation to a level... revocation in a particular market served prior to the revocation. Should the suspension referred to in § 320.2 be revoked, carriers, as a condition to continuing operations under this section, will be required...

Study on the design schemes of the air-conditioning system in a gymnasium

NASA Astrophysics Data System (ADS)

Zhang, Yujin; Wu, Xinwei; Zhang, Jing; Pan, Zhixin

2017-08-01

In view of designing the air conditioning project for a gymnasium successfully, the cooling and heating source schemes are fully studied by analyzing the surrounding environment and energy conditions of the project, as well as the analysis of the initial investment and operating costs, which indicates the air source heat pump air conditioning system is the best choice for the project. The indoor air conditioning schemes are also studied systematically and the optimization of air conditioning schemes is carried out in each area. The principle of operating conditions for the whole year is followed and the quality of indoor air and energy-saving are ensured by the optimized design schemes, which provide references for the air conditioning system design in the same kinds of building.

Roadway Safety Guide

DOT National Transportation Integrated Search

2001-01-01

Roadway safety refers to that portion of overall highway safety that is determined by the roadway's physical features such as road design, roadway signs, pavement markings, operating conditions, roadside objects (such as utility poles, signs, trees, ...

Effect of operating conditions on the exhaust emissions from a gas turbine combustor

NASA Technical Reports Server (NTRS)

Briehl, D.; Papathakos, L.; Strancar, R. J.

1972-01-01

Exhaust concentrations of total unburned hydrocarbons, carbon monoxide, and nitric oxide were measured from a single J-57 combustor liner installed in a 30 diameter test section. Tests were conducted over a range of inlet total pressures from 1 to 20 atmospheres, inlet total temperatures from 310 to 590 K, reference velocities from 8 to m/sec, and fuel-air ratios from 0.004 to 0.015. Most of the data were obtained using ASTM A-1 fuel; however, a limited number of tests was performed with natural gas fuel. Combustion efficiency and emission levels are correlated with operating conditions. Sampling error at operating conditions for which combustion efficiency was below about 90 percent resulted in abnormally low readings for hydrocarbon emissions.

Alternative definition of excitation amplitudes in multi-reference state-specific coupled cluster

NASA Astrophysics Data System (ADS)

Garniron, Yann; Giner, Emmanuel; Malrieu, Jean-Paul; Scemama, Anthony

2017-04-01

A central difficulty of state-specific Multi-Reference Coupled Cluster (MR-CC) in the multi-exponential Jeziorski-Monkhorst formalism concerns the definition of the amplitudes of the single and double excitation operators appearing in the exponential wave operators. If the reference space is a complete active space (CAS), the number of these amplitudes is larger than the number of singly and doubly excited determinants on which one may project the eigenequation, and one must impose additional conditions. The present work first defines a state-specific reference-independent operator T˜ ^ m which acting on the CAS component of the wave function |Ψ0m⟩ maximizes the overlap between (1 +T˜ ^ m ) |Ψ0m⟩ and the eigenvector of the CAS-SD (Singles and Doubles) Configuration Interaction (CI) matrix |ΨCAS-SDm⟩ . This operator may be used to generate approximate coefficients of the triples and quadruples, and a dressing of the CAS-SD CI matrix, according to the intermediate Hamiltonian formalism. The process may be iterated to convergence. As a refinement towards a strict coupled cluster formalism, one may exploit reference-independent amplitudes provided by (1 +T˜ ^ m ) |Ψ0m⟩ to define a reference-dependent operator T^ m by fitting the eigenvector of the (dressed) CAS-SD CI matrix. The two variants, which are internally uncontracted, give rather similar results. The new MR-CC version has been tested on the ground state potential energy curves of 6 molecules (up to triple-bond breaking) and two excited states. The non-parallelism error with respect to the full-CI curves is of the order of 1 mEh.

Spacecraft rendezvous operational considerations affecting vehicle systems design and configuration

NASA Astrophysics Data System (ADS)

Prust, Ellen E.

One lesson learned from Orbiting Maneuvering Vehicle (OMV) program experience is that Design Reference Missions must include an appropriate balance of operations and performance inputs to effectively drive vehicle systems design and configuration. Rendezvous trajectory design is based on vehicle characteristics (e.g., mass, propellant tank size, and mission duration capability) and operational requirements, which have evolved through the Gemini, Apollo, and STS programs. Operational constraints affecting the rendezvous final approach are summarized. The two major objectives of operational rendezvous design are vehicle/crew safety and mission success. Operational requirements on the final approach which support these objectives include: tracking/targeting/communications; trajectory dispersion and navigation uncertainty handling; contingency protection; favorable sunlight conditions; acceptable relative state for proximity operations handover; and compliance with target vehicle constraints. A discussion of the ways each of these requirements may constrain the rendezvous trajectory follows. Although the constraints discussed apply to all rendezvous, the trajectory presented in 'Cargo Transfer Vehicle Preliminary Reference Definition' (MSFC, May 1991) was used as the basis for the comments below.

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

NASA Technical Reports Server (NTRS)

Carreno, Victor A.; Munoz, Cesar A.

2007-01-01

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

Optimisation of flame parameters for simultaneous multi-element atomic absorption spectrometric determination of trace elements in rocks

USGS Publications Warehouse

Kane, J.S.

1988-01-01

A study is described that identifies the optimum operating conditions for the accurate determination of Co, Cu, Mn, Ni, Pb, Zn, Ag, Bi and Cd using simultaneous multi-element atomic absorption spectrometry. Accuracy was measured in terms of the percentage recoveries of the analytes based on certified values in nine standard reference materials. In addition to identifying optimum operating conditions for accurate analysis, conditions resulting in serious matrix interferences and the magnitude of the interferences were determined. The listed elements can be measured with acceptable accuracy in a lean to stoicheiometric flame at measurement heights ???5-10 mm above the burner.

Launch Condition Deviations of Reusable Launch Vehicle Simulations in Exo-Atmospheric Zoom Climbs

NASA Technical Reports Server (NTRS)

Urschel, Peter H.; Cox, Timothy H.

2003-01-01

The Defense Advanced Research Projects Agency has proposed a two-stage system to deliver a small payload to orbit. The proposal calls for an airplane to perform an exo-atmospheric zoom climb maneuver, from which a second-stage rocket is launched carrying the payload into orbit. The NASA Dryden Flight Research Center has conducted an in-house generic simulation study to determine how accurately a human-piloted airplane can deliver a second-stage rocket to a desired exo-atmospheric launch condition. A high-performance, fighter-type, fixed-base, real-time, pilot-in-the-loop airplane simulation has been modified to perform exo-atmospheric zoom climb maneuvers. Four research pilots tracked a reference trajectory in the presence of winds, initial offsets, and degraded engine thrust to a second-stage launch condition. These launch conditions have been compared to the reference launch condition to characterize the expected deviation. At each launch condition, a speed change was applied to the second-stage rocket to insert the payload onto a transfer orbit to the desired operational orbit. The most sensitive of the test cases was the degraded thrust case, yielding second-stage launch energies that were too low to achieve the radius of the desired operational orbit. The handling qualities of the airplane, as a first-stage vehicle, have also been investigated.

Air pollution control through biotrickling filters: a review considering operational aspects and expected performance.

PubMed

Schiavon, Marco; Ragazzi, Marco; Rada, Elena Cristina; Torretta, Vincenzo

2016-12-01

The biological removal of pollutants, especially through biotrickling filters (BTFs), has recently become attractive for the low investment and operational costs and the low secondary pollution. This paper is intended to investigate the state of the art on BTF applications. After an overview on the biodegradation process and the typical parameters involved, this paper presents the analysis of a group of 16 literature studies chosen as the references for this sector. The reference studies differ from one another by the pollutants treated (volatile organic compounds [VOC], hydrogen sulphide, nitrogen oxides and trimethylamine), the geometry and size of the BTFs, and the procedures of the tests. The reference studies are analyzed and discussed in terms of the operational conditions and the results obtained, especially with respect to the removal efficiencies (REs) and the elimination capacities (ECs) of the pollutants considered. Empty bed residence time (EBRT), pollutant loading rate, temperature, pH, oxygen availability, trickling liquid flow rate, inoculum selection and biomass control strategies revealed to be the most important operational factors influencing the removal performance of a BTF.

46 CFR 96.35-5 - General.

Code of Federal Regulations, 2012 CFR

2012-10-01

... by reference, see § 96.01-3). (d) All lifelines shall be of steel or bronze wire rope. Steel wire... breaking strength of 1,500 pounds. (e) All equipment shall be maintained in an operative condition, and it...

46 CFR 96.35-5 - General.

Code of Federal Regulations, 2013 CFR

2013-10-01

... by reference, see § 96.01-3). (d) All lifelines shall be of steel or bronze wire rope. Steel wire... breaking strength of 1,500 pounds. (e) All equipment shall be maintained in an operative condition, and it...

46 CFR 96.35-5 - General.

Code of Federal Regulations, 2014 CFR

2014-10-01

... by reference, see § 96.01-3). (d) All lifelines shall be of steel or bronze wire rope. Steel wire... breaking strength of 1,500 pounds. (e) All equipment shall be maintained in an operative condition, and it...

46 CFR 96.35-5 - General.

Code of Federal Regulations, 2011 CFR

2011-10-01

... by reference, see § 96.01-3). (d) All lifelines shall be of steel or bronze wire rope. Steel wire... breaking strength of 1,500 pounds. (e) All equipment shall be maintained in an operative condition, and it...

Improved fault ride through capability of DFIG based wind turbines using synchronous reference frame control based dynamic voltage restorer.

PubMed

Rini Ann Jerin, A; Kaliannan, Palanisamy; Subramaniam, Umashankar

2017-09-01

Fault ride through (FRT) capability in wind turbines to maintain the grid stability during faults has become mandatory with the increasing grid penetration of wind energy. Doubly fed induction generator based wind turbine (DFIG-WT) is the most popularly utilized type of generator but highly susceptible to the voltage disturbances in grid. Dynamic voltage restorer (DVR) based external FRT capability improvement is considered. Since DVR is capable of providing fast voltage sag mitigation during faults and can maintain the nominal operating conditions for DFIG-WT. The effectiveness of the DVR using Synchronous reference frame (SRF) control is investigated for FRT capability in DFIG-WT during both balanced and unbalanced fault conditions. The operation of DVR is confirmed using time-domain simulation in MATLAB/Simulink using 1.5MW DFIG-WT. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Enabling Smart Air Conditioning by Sensor Development: A Review

PubMed Central

Cheng, Chin-Chi; Lee, Dasheng

2016-01-01

The study investigates the development of sensors, in particular the use of thermo-fluidic sensors and occupancy detectors, to achieve smart operation of air conditioning systems. Smart operation refers to the operation of air conditioners by the reinforcement of interaction to achieve both thermal comfort and energy efficiency. Sensors related to thermal comfort include those of temperature, humidity, and pressure and wind velocity anemometers. Improvements in their performance in the past years have been studied by a literature survey. Traditional occupancy detection using passive infra-red (PIR) sensors and novel methodologies using smartphones and wearable sensors are both discussed. Referring to the case studies summarized in this study, air conditioning energy savings are evaluated quantitatively. Results show that energy savings of air conditioners before 2000 was 11%, and 30% after 2000 by the integration of thermo-fluidic sensors and occupancy detectors. By utilizing wearable sensing to detect the human motions, metabolic rates and related information, the energy savings can reach up to 46.3% and keep the minimum change of predicted mean vote (∆PMV→0), which means there is no compromise in thermal comfort. This enables smart air conditioning to compensate for the large variations from person to person in terms of physiological and psychological satisfaction, and find an optimal temperature for everyone in a given space. However, this tendency should be evidenced by more experimental results in the future. PMID:27916906

Back disorders and health problems among subway train operators exposed to whole-body vibration.

PubMed

Johanning, E

1991-12-01

Back disease associated with whole-body vibration has not been evaluated for subway train operators. A recent study demonstrated that this group is exposed to whole-body vibration at levels above the international standard. To investigate this risk further, a self-administered questionnaire survey was conducted among subway train operators (N = 492) and a similar reference group (N = 92). The operators had a higher prevalence than the referents in all aspects of back problems, particularly for cervical and lower back pain. In a multiple logistic regression model, the odds ratio for sciatic pain among subway train operators was 3.9 (95% CI 1.7-8.6); the operators also had a higher risk of hearing-related problems (odds ratio 3.2, 95% CI 0.6-17.4) and of gastrointestinal problems (odds ratio 1.6, 95% CI 1.1-2.5). Although a cumulative dose-response relationship could not be statistically demonstrated, the findings appear to be related to exposure to whole-body vibration and inadequate ergonomic conditions.

System for monitoring non-coincident, nonstationary process signals

DOEpatents

Gross, Kenneth C.; Wegerich, Stephan W.

2005-01-04

An improved system for monitoring non-coincident, non-stationary, process signals. The mean, variance, and length of a reference signal is defined by an automated system, followed by the identification of the leading and falling edges of a monitored signal and the length of the monitored signal. The monitored signal is compared to the reference signal, and the monitored signal is resampled in accordance with the reference signal. The reference signal is then correlated with the resampled monitored signal such that the reference signal and the resampled monitored signal are coincident in time with each other. The resampled monitored signal is then compared to the reference signal to determine whether the resampled monitored signal is within a set of predesignated operating conditions.

Environmental control/life support system for Space Station

NASA Technical Reports Server (NTRS)

Miller, C. W.; Heppner, D. B.; Schubert, F. H.; Dahlhausen, M. J.

1986-01-01

The functional, operational, and design load requirements for the Environmental Control/Life Support System (ECLSS) are described. The ECLSS is divided into two groups: (1) an atmosphere management group and (2) a water and waste management group. The interaction between the ECLSS and the Space Station Habitability System is examined. The cruciform baseline station design, the delta and big T module configuration, and the reference Space Station configuration are evaluated in terms of ECLSS requirements. The distribution of ECLSS equipment in a reference Space Station configuration is studied as a function of initial operating conditions and growth orbit capabilities. The benefits of water electrolysis as a Space Station utility are considered.

Context controls access to working and reference memory in the pigeon (Columba livia).

PubMed

Roberts, William A; Macpherson, Krista; Strang, Caroline

2016-01-01

The interaction between working and reference memory systems was examined under conditions in which salient contextual cues were presented during memory retrieval. Ambient colored lights (red or green) bathed the operant chamber during the presentation of comparison stimuli in delayed matching-to-sample training (working memory) and during the presentation of the comparison stimuli as S+ and S- cues in discrimination training (reference memory). Strong competition between memory systems appeared when the same contextual cue appeared during working and reference memory training. When different contextual cues were used, however, working memory was completely protected from reference memory interference. © 2016 Society for the Experimental Analysis of Behavior.

System for monitoring an industrial or biological process

DOEpatents

Gross, Kenneth C.; Wegerich, Stephan W.; Vilim, Rick B.; White, Andrew M.

1998-01-01

A method and apparatus for monitoring and responding to conditions of an industrial process. Industrial process signals, such as repetitive manufacturing, testing and operational machine signals, are generated by a system. Sensor signals characteristic of the process are generated over a time length and compared to reference signals over the time length. The industrial signals are adjusted over the time length relative to the reference signals, the phase shift of the industrial signals is optimized to the reference signals and the resulting signals output for analysis by systems such as SPRT.

System for monitoring an industrial or biological process

DOEpatents

Gross, K.C.; Wegerich, S.W.; Vilim, R.B.; White, A.M.

1998-06-30

A method and apparatus are disclosed for monitoring and responding to conditions of an industrial process. Industrial process signals, such as repetitive manufacturing, testing and operational machine signals, are generated by a system. Sensor signals characteristic of the process are generated over a time length and compared to reference signals over the time length. The industrial signals are adjusted over the time length relative to the reference signals, the phase shift of the industrial signals is optimized to the reference signals and the resulting signals output for analysis by systems such as SPRT. 49 figs.

Sulfur recirculation for increased electricity production in Waste-to-Energy plants.

PubMed

Andersson, Sven; Blomqvist, Evalena W; Bäfver, Linda; Jones, Frida; Davidsson, Kent; Froitzheim, Jan; Karlsson, Martin; Larsson, Erik; Liske, Jesper

2014-01-01

Sulfur recirculation is a new technology for reducing boiler corrosion and dioxin formation. It was demonstrated in full-scale tests at a Waste to Energy plant in Göteborg (Sweden) during nearly two months of operation. Sulfur was recirculated as sulfuric acid from the flue gas cleaning back to the boiler, thus creating a sulfur loop. The new technology was evaluated by extensive measurement campaigns during operation under normal conditions (reference case) and operation with sulfur recirculation. The chlorine content of both fly ash and boiler ash decreased and the sulfur content increased during the sulfur recirculation tests. The deposit growth and the particle concentration decreased with sulfur recirculation and the dioxin concentration (I-TEQ) of the flue gas was reduced by approximately 25%. Sulfuric acid dew point measurements showed that the sulfuric acid dosage did not lead to elevated SO3 concentrations, which may otherwise induce low temperature corrosion. In the sulfur recirculation corrosion probe exposures, the corrosion rate decreased for all tested materials (16Mo3, Sanicro 28 and Inconel 625) and material temperatures (450 °C and 525 °C) compared to the reference exposure. The corrosion rates were reduced by 60-90%. Sulfur recirculation prevented the formation of transition metal chlorides at the metal/oxide interface, formation of chromate and reduced the presence of zinc in the corrosion products. Furthermore, measured corrosion rates at 525 °C with sulfur recirculation in operation were similar or lower compared to those measured at 450 °C material temperature in reference conditions, which corresponds to normal operation at normal steam temperatures. This implies that sulfur recirculation allows for higher steam data and electricity production without increasing corrosion. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Performance of a catalytic reactor at simulated gas turbine combustor operating conditions

NASA Technical Reports Server (NTRS)

Anderson, D. N.; Tacina, R. R.; Mroz, T. S.

1975-01-01

The performance of a catalytic reactor 12 cm in diameter and 17 cm long was evaluated at simulated gas turbine combustor operating conditions using premixed propane and air. Inlet temperatures of 600 and 800 K, pressures of 3 and 6 atm, and reference velocities of 9 to 30 m/s were tested. Data were taken for equivalence ratios as high as 0.43. The operating range was limited on the low-temperature side by very poor efficiency; the minimum exit temperature for good performance ranged from 1400 to 1600 K depending on inlet conditions. As exit temperatures were raised above this minimum, emissions of unburned hydrocarbons decreased, carbon monoxide emissions became generally less than 1 g CO/kg fuel, and nitrogen oxides were less than about 0.1 g NO2/kg fuel.

Biofiltration for stormwater harvesting: Comparison of Campylobacter spp. and Escherichia coli removal under normal and challenging operational conditions

NASA Astrophysics Data System (ADS)

Chandrasena, G. I.; Deletic, A.; McCarthy, D. T.

2016-06-01

Knowledge of pathogen removal in stormwater biofilters (also known as stormwater bioretention systems or rain gardens) has predominately been determined using bacterial indicators, and the removal of reference pathogens in these systems has rarely been investigated. Furthermore, current understanding of indicator bacteria removal in these systems is largely built upon laboratory-scale work. This paper examines whether indicator organism removal from urban stormwater using biofilters in laboratory settings are representative of the removal of pathogens in field conditions, by studying the removal of Escherichia coli (a typical indicator microorganism) and Campylobacter spp. (a typical reference pathogen) from urban stormwater by two established field-scale biofilters. It was found that E. coli log reduction was higher than that of Campylobacter spp. in both biofilters, and that there was no correlation between E. coli and Campylobacter spp. log removal performance. This confirms that E. coli behaves significantly differently to this reference pathogen, reinforcing that single organisms should not be employed to understand faecal microorganism removal in urban stormwater treatment systems. The average reduction in E. coli from only one of the tested biofilters was able to meet the log reduction targets suggested in the current Australian stormwater harvesting guidelines for irrigating sports fields and golf courses. The difference in the performance of the two biofilters is likely a result of a number of design and operational factors; the most important being that the biofilter that did not meet the guidelines was tested using extremely high influent volumes and microbial concentrations, and long antecedent dry weather periods. As such, the E. coli removal performances identified in this study confirmed laboratory findings that inflow concentration and antecedent dry period impact overall microbial removal. In general, this paper emphasizes the need for the validation of stormwater harvesting systems, namely, the testing of treatment systems under challenging operational conditions using multiple indicators and reference pathogens.

Stable Adaptive Inertial Control of a Doubly-Fed Induction Generator

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

Kang, Moses; Muljadi, Eduard; Hur, Kyeon

2016-11-01

This paper proposes a stable adaptive inertial control scheme of a doubly-fed induction generator. The proposed power reference is defined in two sections: the deceleration period and the acceleration period. The power reference in the deceleration period consists of a constant and the reference for maximum power point tracking (MPPT) operation. The latter contributes to preventing a second frequency dip (SFD) in this period because its reduction rate is large at the early stage of an event but quickly decreases with time. To improve the frequency nadir (FN), the constant value is set to be proportional to the rotor speedmore » prior to an event. The reference ensures that the rotor speed converges to a stable operating region. To accelerate the rotor speed while causing a small SFD, when the rotor speed converges, the power reference is reduced by a small amount and maintained until it meets the MPPT reference. The results show that the scheme causes a small SFD while improving the FN and the rate of change of frequency in any wind conditions, even in a grid that has a high penetration of wind power.« less

Volitional enhancement of firing synchrony and oscillation by neuronal operant conditioning: interaction with neurorehabilitation and brain-machine interface

PubMed Central

Sakurai, Yoshio; Song, Kichan; Tachibana, Shota; Takahashi, Susumu

2014-01-01

In this review, we focus on neuronal operant conditioning in which increments in neuronal activities are directly rewarded without behaviors. We discuss the potential of this approach to elucidate neuronal plasticity for enhancing specific brain functions and its interaction with the progress in neurorehabilitation and brain-machine interfaces. The key to-be-conditioned activities that this paper emphasizes are synchronous and oscillatory firings of multiple neurons that reflect activities of cell assemblies. First, we introduce certain well-known studies on neuronal operant conditioning in which conditioned enhancements of neuronal firing were reported in animals and humans. These studies demonstrated the feasibility of volitional control over neuronal activity. Second, we refer to the recent studies on operant conditioning of synchrony and oscillation of neuronal activities. In particular, we introduce a recent study showing volitional enhancement of oscillatory activity in monkey motor cortex and our study showing selective enhancement of firing synchrony of neighboring neurons in rat hippocampus. Third, we discuss the reasons for emphasizing firing synchrony and oscillation in neuronal operant conditioning, the main reason being that they reflect the activities of cell assemblies, which have been suggested to be basic neuronal codes representing information in the brain. Finally, we discuss the interaction of neuronal operant conditioning with neurorehabilitation and brain-machine interface (BMI). We argue that synchrony and oscillation of neuronal firing are the key activities required for developing both reliable neurorehabilitation and high-performance BMI. Further, we conclude that research of neuronal operant conditioning, neurorehabilitation, BMI, and system neuroscience will produce findings applicable to these interrelated fields, and neuronal synchrony and oscillation can be a common important bridge among all of them. PMID:24567704

Volitional enhancement of firing synchrony and oscillation by neuronal operant conditioning: interaction with neurorehabilitation and brain-machine interface.

PubMed

Sakurai, Yoshio; Song, Kichan; Tachibana, Shota; Takahashi, Susumu

2014-01-01

In this review, we focus on neuronal operant conditioning in which increments in neuronal activities are directly rewarded without behaviors. We discuss the potential of this approach to elucidate neuronal plasticity for enhancing specific brain functions and its interaction with the progress in neurorehabilitation and brain-machine interfaces. The key to-be-conditioned activities that this paper emphasizes are synchronous and oscillatory firings of multiple neurons that reflect activities of cell assemblies. First, we introduce certain well-known studies on neuronal operant conditioning in which conditioned enhancements of neuronal firing were reported in animals and humans. These studies demonstrated the feasibility of volitional control over neuronal activity. Second, we refer to the recent studies on operant conditioning of synchrony and oscillation of neuronal activities. In particular, we introduce a recent study showing volitional enhancement of oscillatory activity in monkey motor cortex and our study showing selective enhancement of firing synchrony of neighboring neurons in rat hippocampus. Third, we discuss the reasons for emphasizing firing synchrony and oscillation in neuronal operant conditioning, the main reason being that they reflect the activities of cell assemblies, which have been suggested to be basic neuronal codes representing information in the brain. Finally, we discuss the interaction of neuronal operant conditioning with neurorehabilitation and brain-machine interface (BMI). We argue that synchrony and oscillation of neuronal firing are the key activities required for developing both reliable neurorehabilitation and high-performance BMI. Further, we conclude that research of neuronal operant conditioning, neurorehabilitation, BMI, and system neuroscience will produce findings applicable to these interrelated fields, and neuronal synchrony and oscillation can be a common important bridge among all of them.

Differential capacitance probe for process control involving aqueous dielectric fluids

DOEpatents

Svoboda, John M.; Morrison, John L.

2002-10-08

A differential capacitance probe device for process control involving aqueous dielectric fluids is disclosed. The device contains a pair of matched capacitor probes configured in parallel, one immersed in a sealed container of reference fluid, and the other immersed in the process fluid. The sealed container holding the reference fluid is also immersed in the process fluid, hence both probes are operated at the same temperature. Signal conditioning measures the difference in capacitance between the reference probe and the process probe. The resulting signal is a control error signal that can be used to control the process.

Proton Tolerance of SiGe Precision Voltage References for Extreme Temperature Range Electronics

NASA Astrophysics Data System (ADS)

Najafizadeh, Laleh; Bellini, Marco; Prakash, A. P. Gnana; Espinel, Gustavo A.; Cressler, John D.; Marshall, Paul W.; Marshall, Cheryl J.

2006-12-01

A comprehensive investigation of the effects of proton irradiation on the performance of SiGe BiCMOS precision voltage references intended for extreme environment operational conditions is presented. The voltage reference circuits were designed in two distinct SiGe BiCMOS technology platforms (first generation (50 GHz) and third generation (200 GHz)) in order to investigate the effect of technology scaling. The circuits were irradiated at both room temperature and at 77 K. Measurement results from the experiments indicate that the proton-induced changes in the SiGe bandgap references are minor, even down to cryogenic temperatures, clearly good news for the potential application of SiGe mixed-signal circuits in emerging extreme environments

Spent sealed radium sources conditioning in Latin America

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

Mourao, R.P.

1999-06-01

The management of spent sealed sources is considered by the International Atomic Energy Agency (IAEA) one of the greatest challenges faced by nuclear authorities today, especially in developing countries. One of the Agency`s initiatives to tackle this problem is the Spent Radium Sources Conditioning Project, a worldwide project relying on the regional co-operation between countries. A team from the Brazilian nuclear research institute Centro de Desenvolvimento da Tecnologia Nuclear (CDTN) was chosen as the expert team to carry out the operations in Latin America; since December 1996 radium sources have been safely conditioned in Uruguay, Nicaragua, Guatemala, Ecuador and Paraguay.more » A Quality Assurance Program was established, encompassing the qualification of the capsule welding process, written operational procedures referring to all major steps of the operation, calibration of monitors and information retrievability. A 200L carbon steel drum-based packaging concept was used to condition the sources, its cavity being designed to receive the lead shield device containing stainless steel capsules with the radium sources. As a result of these operations, a total amount of 2,897 mg of needles, tubes, medical applicators, standard sources for calibration, lightning rods, secondary wastes and contaminated objects were stored in proper conditions and are now under control of the nuclear authorities of the visited countries.« less

NASTRAN flutter analysis of advanced turbopropellers

NASA Technical Reports Server (NTRS)

Elchuri, V.; Smith, G. C. C.

1982-01-01

An existing capability developed to conduct modal flutter analysis of tuned bladed-shrouded discs in NASTRAN was modified and applied to investigate the subsonic unstalled flutter characteristics of advanced turbopropellers. The modifications pertain to the inclusion of oscillatory modal aerodynamic loads of blades with large (backward and forward) variable sweep. The two dimensional subsonic cascade unsteady aerodynamic theory was applied in a strip theory manner with appropriate modifications for the sweep effects. Each strip is associated with a chord selected normal to any spanwise reference curve such as the blade leading edge. The stability of three operating conditions of a 10-bladed propeller is analyzed. Each of these operating conditions is iterated once to determine the flutter boundary. A 5-bladed propeller is also analyzed at one operating condition to investigate stability. Analytical results obtained are in very good agreement with those from wind tunnel tests.

Low-noise pulse conditioner

DOEpatents

Bird, D.A.

1981-06-16

A low-noise pulse conditioner is provided for driving electronic digital processing circuitry directly from differentially induced input pulses. The circuit uses a unique differential-to-peak detector circuit to generate a dynamic reference signal proportional to the input peak voltage. The input pulses are compared with the reference signal in an input network which operates in full differential mode with only a passive input filter. This reduces the introduction of circuit-induced noise, or jitter, generated in ground referenced input elements normally used in pulse conditioning circuits, especially speed transducer processing circuits. This circuit may be used for conditioning the sensor signal from the Fidler coil in a gas centrifuge for separation of isotopic gaseous mixtures.

Operational Characteristics of an Accelerator Driven Fissile Solution System

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

Kimpland, Robert Herbert

Operational characteristics represent the set of responses that a nuclear system exhibits during normal operation. Operators rely on this behavior to assess the status of the system and to predict the consequences of off-normal events. These characteristics largely refer to the relationship between power and system operating conditions. The static and dynamic behavior of a chain-reacting system, operating at sufficient power, is primarily governed by reactivity effects. The science of reactor physics has identified and evaluated a number of such effects, including Doppler broadening and shifts in the thermal neutron spectrum. Often these reactivity effects are quantified in the formmore » of feedback coefficients that serve as coupling coefficients relating the neutron population and the physical mechanisms that drive reactivity effects, such as fissile material temperature and density changes. The operational characteristics of such nuclear systems usually manifest themselves when perturbations between system power (neutron population) and system operating conditions arise. Successful operation of such systems requires the establishment of steady equilibrium conditions. However, prior to obtaining the desired equilibrium (steady-state) conditions, an approach from zero-power (startup) must occur. This operational regime may possess certain limiting system conditions that must be maintained to achieve effective startup. Once steady-state is achieved, a key characteristic of this operational regime is the level of stability that the system possesses. Finally, a third operational regime, shutdown, may also possess limiting conditions of operation that must be maintained. This report documents the operational characteristics of a “generic” Accelerator Driven Fissile Solution (ADFS) system during the various operational regimes of startup, steady-state operation, and shutdown. Typical time-dependent behavior for each operational regime will be illustrated, and key system parameters, such as response times, will be quantified. A generalized linear systems analysis of steady-state operations will be performed to evaluate the level of stability of ADFS systems. This information should provide a basic understanding of typical ADFS system operational behavior, and facilitate the development of monitoring procedures and operator aids.« less

Predictive Accuracy of Sweep Frequency Impedance Technology in Identifying Conductive Conditions in Newborns.

PubMed

Aithal, Venkatesh; Kei, Joseph; Driscoll, Carlie; Murakoshi, Michio; Wada, Hiroshi

2018-02-01

Diagnosing conductive conditions in newborns is challenging for both audiologists and otolaryngologists. Although high-frequency tympanometry (HFT), acoustic stapedial reflex tests, and wideband absorbance measures are useful diagnostic tools, there is performance measure variability in their detection of middle ear conditions. Additional diagnostic sensitivity and specificity measures gained through new technology such as sweep frequency impedance (SFI) measures may assist in the diagnosis of middle ear dysfunction in newborns. The purpose of this study was to determine the test performance of SFI to predict the status of the outer and middle ear in newborns against commonly used reference standards. Automated auditory brainstem response (AABR), HFT (1000 Hz), transient evoked otoacoustic emission (TEOAE), distortion product otoacoustic emission (DPOAE), and SFI tests were administered to the study sample. A total of 188 neonates (98 males and 90 females) with a mean gestational age of 39.4 weeks were included in the sample. Mean age at the time of testing was 44.4 hr. Diagnostic accuracy of SFI was assessed in terms of its ability to identify conductive conditions in neonates when compared with nine different reference standards (including four single tests [AABR, HFT, TEOAE, and DPOAE] and five test batteries [HFT + DPOAE, HFT + TEOAE, DPOAE + TEOAE, DPOAE + AABR, and TEOAE + AABR]), using receiver operating characteristic (ROC) analysis and traditional test performance measures such as sensitivity and specificity. The test performance of SFI against the test battery reference standard of HFT + DPOAE and single reference standard of HFT was high with an area under the ROC curve (AROC) of 0.87 and 0.82, respectively. Although the HFT + DPOAE test battery reference standard performed better than the HFT reference standard in predicting middle ear conductive conditions in neonates, the difference in AROC was not significant. Further analysis revealed that the highest sensitivity and specificity for SFI (86% and 88%, respectively) was obtained when compared with the reference standard of HFT + DPOAE. Among the four single reference standards, SFI had the highest sensitivity and specificity (76% and 88%, respectively) when compared against the HFT reference standard. The high test performance of SFI against the HFT and HFT + DPOAE reference standards indicates that the SFI measure has appropriate diagnostic accuracy in detection of conductive conditions in newborns. Hence, the SFI test could be used as adjunct tool to identify conductive conditions in universal newborn hearing screening programs, and can also be used in diagnostic follow-up assessments. American Academy of Audiology

RANS Simulation (Rotating Reference Frame Model [RRF]) of Single Lab-Scaled DOE RM1 MHK Turbine

DOE Data Explorer

Javaherchi, Teymour; Stelzenmuller, Nick; Aliseda, Alberto; Seydel, Joseph

2014-04-15

Attached are the .cas and .dat files for the Reynolds Averaged Navier-Stokes (RANS) simulation of a single lab-scaled DOE RM1 turbine implemented in ANSYS FLUENT CFD-package. The lab-scaled DOE RM1 is a re-design geometry, based of the full scale DOE RM1 design, producing same power output as the full scale model, while operating at matched Tip Speed Ratio values at reachable laboratory Reynolds number (see attached paper). In this case study taking advantage of the symmetry of lab-scaled DOE RM1 geometry, only half of the geometry is models using (Single) Rotating Reference Frame model [RRF]. In this model RANS equations, coupled with k-\\omega turbulence closure model, are solved in the rotating reference frame. The actual geometry of the turbine blade is included and the turbulent boundary layer along the blade span is simulated using wall-function approach. The rotation of the blade is modeled by applying periodic boundary condition to sets of plane of symmetry. This case study simulates the performance and flow field in the near and far wake of the device at the desired operating conditions. The results of these simulations were validated against in-house experimental data. Please see the attached paper.

47 CFR 80.179 - Unattended operation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... DSC in accordance with ITU-R Recommendation M.493-11, “Digital Selective-calling System for Use in the...., Washington, DC (Reference Information Center) or at the National Archives and Records Administration (NARA... condition related to ship safety. (3) The “ROUTINE” DSC category must be used. (4) Communications must be...

"Plus Ca Change...?": Racism in Higher Education.

ERIC Educational Resources Information Center

Exum, William H.

The meaning, operation, and impact of institutional racism in higher education are examined with attention to both past and present conditions. Institutional racism is examined with reference to several specific issues: barriers to the entry of blacks, as both students and staff, into American higher education; curriculum and academic programs;…

47 CFR 80.179 - Unattended operation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... DSC in accordance with ITU-R M.493-13 and ITU-R M.541-9 (both incorporated by reference, see § 80.7), as modified by this section. (2) Sensors must automatically activate the transmitter only under one or more of the following conditions: (i) Fire, explosion; (ii) Flooding; (iii) Collision; (iv...

47 CFR 80.179 - Unattended operation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... DSC in accordance with ITU-R M.493-13 and ITU-R M.541-9 (both incorporated by reference, see § 80.7), as modified by this section. (2) Sensors must automatically activate the transmitter only under one or more of the following conditions: (i) Fire, explosion; (ii) Flooding; (iii) Collision; (iv...

46 CFR 195.35-5 - General.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 1014 (incorporated by reference, see § 195.01-3). (d) All lifelines shall be of steel or bronze wire rope. Steel wire rope shall be either inherently corrosion-resistant, or made so by galvanizing or... breaking strength of 1,500 pounds. (e) All equipment shall be maintained in an operative condition, and it...

46 CFR 195.35-5 - General.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 1014 (incorporated by reference, see § 195.01-3). (d) All lifelines shall be of steel or bronze wire rope. Steel wire rope shall be either inherently corrosion-resistant, or made so by galvanizing or... breaking strength of 1,500 pounds. (e) All equipment shall be maintained in an operative condition, and it...

46 CFR 195.35-5 - General.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 1014 (incorporated by reference, see § 195.01-3). (d) All lifelines shall be of steel or bronze wire rope. Steel wire rope shall be either inherently corrosion-resistant, or made so by galvanizing or... breaking strength of 1,500 pounds. (e) All equipment shall be maintained in an operative condition, and it...

Determination of internal controls for quantitative gene expression of Isochrysis zhangjiangensis at nitrogen stress condition

NASA Astrophysics Data System (ADS)

Wu, Shuang; Zhou, Jiannan; Cao, Xupeng; Xue, Song

2016-02-01

Isochrysis zhangjiangensis is a potential marine microalga for biodiesel production, which accumulates lipid under nitrogen limitation conditions, but the mechanism on molecular level is veiled. Quantitative real-time polymerase chain reaction (qPCR) provides the possibility to investigate the gene expression levels, and a valid reference for data normalization is an essential prerequisite for firing up the analysis. In this study, five housekeeping genes, actin (ACT), α-tubulin (TUA), ß-tubulin (TUB), ubiquitin (UBI), 18S rRNA (18S) and one target gene, diacylglycerol acyltransferase (DGAT), were used for determining the reference. By analyzing the stabilities based on calculation of the stability index and on operating the two types of software, geNorm and bestkeeper, it showed that the reference genes widely used in higher plant and microalgae, such as UBI, TUA and 18S, were not the most stable ones in nitrogen-stressed I. zhangjiangensis, and thus are not suitable for exploring the mRNA expression levels under these experimental conditions. Our results show that ACT together with TUB is the most feasible internal control for investigating gene expression under nitrogen-stressed conditions. Our findings will contribute not only to future qPCR studies of I. zhangjiangensis, but also to verification of comparative transcriptomics studies of the microalgae under similar conditions.

Patient doses and occupational exposure in a hybrid operating room.

PubMed

Andrés, C; Pérez-García, H; Agulla, M; Torres, R; Miguel, D; Del Castillo, A; Flota, C M; Alonso, D; de Frutos, J; Vaquero, C

2017-05-01

This study aimed to characterize the radiation exposure to patients and workers in a new vascular hybrid operating room during X-ray-guided procedures. During one year, data from 260 interventions performed in a hybrid operating room equipped with a Siemens Artis Zeego angiography system were monitored. The patient doses were analysed using the following parameters: radiation time, kerma-area product, patient entrance reference point dose and peak skin dose. Staff radiation exposure and ambient dose equivalent were also measured using direct reading dosimeters and thermoluminescent dosimeters. The radiation time, kerma-area product, patient entrance reference point dose and peak skin dose were, on average, 19:15min, 67Gy·cm 2 , 0.41Gy and 0.23Gy, respectively. Although the contribution of the acquisition mode was smaller than 5% in terms of the radiation time, this mode accounted for more than 60% of the effective dose per patient. All of the worker dose measurements remained below the limits established by law. The working conditions in the hybrid operating room HOR are safe in terms of patient and staff radiation protection. Nevertheless, doses are highly dependent on the workload; thus, further research is necessary to evaluate any possible radiological deviation of the daily working conditions in the HOR. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Criticality safety strategy and analysis summary for the fuel cycle facility electrorefiner at Argonne National Laboratory West

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

Mariani, R.D.; Benedict, R.W.; Lell, R.M.

1996-05-01

As part of the termination activities of Experimental Breeder Reactor II (EBR-II) at Argonne National Laboratory (ANL) West, the spent metallic fuel from EBR-II will be treated in the fuel cycle facility (FCF). A key component of the spent-fuel treatment process in the FCF is the electrorefiner (ER) in which the actinide metals are separated from the active metal fission products and the reactive bond sodium. In the electrorefining process, the metal fuel is anodically dissolved into a high-temperature molten salt, and refined uranium or uranium/plutonium products are deposited at cathodes. The criticality safety strategy and analysis for the ANLmore » West FCF ER is summarized. The FCF ER operations and processes formed the basis for evaluating criticality safety and control during actinide metal fuel refining. To show criticality safety for the FCF ER, the reference operating conditions for the ER had to be defined. Normal operating envelopes (NOEs) were then defined to bracket the important operating conditions. To keep the operating conditions within their NOEs, process controls were identified that can be used to regulate the actinide forms and content within the ER. A series of operational checks were developed for each operation that will verify the extent or success of an operation. The criticality analysis considered the ER operating conditions at their NOE values as the point of departure for credible and incredible failure modes. As a result of the analysis, FCF ER operations were found to be safe with respect to criticality.« less

Detection and classification of alarm threshold violations in condition monitoring systems working in highly varying operational conditions

NASA Astrophysics Data System (ADS)

Strączkiewicz, M.; Barszcz, T.; Jabłoński, A.

2015-07-01

All commonly used condition monitoring systems (CMS) enable defining alarm thresholds that enhance efficient surveillance and maintenance of dynamic state of machinery. The thresholds are imposed on the measured values such as vibration-based indicators, temperature, pressure, etc. For complex machinery such as wind turbine (WT) the total number of thresholds might be counted in hundreds multiplied by the number of operational states. All the parameters vary not only due to possible machinery malfunctions, but also due to changes in operating conditions and these changes are typically much stronger than the former ones. Very often, such a behavior may lead to hundreds of false alarms. Therefore, authors propose a novel approach based on parameterized description of the threshold violation. For this purpose the novelty and severity factors are introduced. The first parameter refers to the time of violation occurrence while the second one describes the impact of the indicator-increase to the entire machine. Such approach increases reliability of the CMS by providing the operator with the most useful information of the system events. The idea of the procedure is presented on a simulated data similar to those from a wind turbine.

Periodic equivalence ratio modulation method and apparatus for controlling combustion instability

DOEpatents

Richards, George A.; Janus, Michael C.; Griffith, Richard A.

2000-01-01

The periodic equivalence ratio modulation (PERM) method and apparatus significantly reduces and/or eliminates unstable conditions within a combustion chamber. The method involves modulating the equivalence ratio for the combustion device, such that the combustion device periodically operates outside of an identified unstable oscillation region. The equivalence ratio is modulated between preselected reference points, according to the shape of the oscillation region and operating parameters of the system. Preferably, the equivalence ratio is modulated from a first stable condition to a second stable condition, and, alternatively, the equivalence ratio is modulated from a stable condition to an unstable condition. The method is further applicable to multi-nozzle combustor designs, whereby individual nozzles are alternately modulated from stable to unstable conditions. Periodic equivalence ratio modulation (PERM) is accomplished by active control involving periodic, low frequency fuel modulation, whereby low frequency fuel pulses are injected into the main fuel delivery. Importantly, the fuel pulses are injected at a rate so as not to affect the desired time-average equivalence ratio for the combustion device.

Aircraft Flight Envelope Determination using Upset Detection and Physical Modeling Methods

NASA Technical Reports Server (NTRS)

Keller, Jeffrey D.; McKillip, Robert M. Jr.; Kim, Singwan

2009-01-01

The development of flight control systems to enhance aircraft safety during periods of vehicle impairment or degraded operations has been the focus of extensive work in recent years. Conditions adversely affecting aircraft flight operations and safety may result from a number of causes, including environmental disturbances, degraded flight operations, and aerodynamic upsets. To enhance the effectiveness of adaptive and envelope limiting controls systems, it is desirable to examine methods for identifying the occurrence of anomalous conditions and for assessing the impact of these conditions on the aircraft operational limits. This paper describes initial work performed toward this end, examining the use of fault detection methods applied to the aircraft for aerodynamic performance degradation identification and model-based methods for envelope prediction. Results are presented in which a model-based fault detection filter is applied to the identification of aircraft control surface and stall departure failures/upsets. This application is supported by a distributed loading aerodynamics formulation for the flight dynamics system reference model. Extensions for estimating the flight envelope due to generalized aerodynamic performance degradation are also described.

SSI-ARC Flight Test 3 Data Review

NASA Technical Reports Server (NTRS)

Gong, Chester; Wu, Minghong G.

2015-01-01

The "Unmanned Aircraft System (UAS) Integration into the National Airspace System (NAS)" Project conducted flight test program, referred to as Flight Test 3, at Armstrong Flight Research Center from June - August 2015. Four flight test days were dedicated to the NASA Ames-developed Detect and Avoid (DAA) System referred to as Autoresolver. The encounter scenarios, which involved NASA's Ikhana UAS and a manned intruder aircraft, were designed to collect data on DAA system performance in real-world conditions and uncertainties with four different surveillance sensor systems. Resulting flight test data and analysis results will be used to evaluate the DAA system performance (e.g., trajectory prediction accuracy, threat detection) and to add fidelity to simulation models used to inform Minimum Operating Performance Standards (MOPS) for integrating UAS into routine NAS operations.

KCA drilling combats freak seas

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

Not Available

1984-08-01

This article describes the unusual sea conditions experienced by the crew of the KCA Drilling Company's positioned drillship, the Polly Bristol. The drilling took place in 1,000 feet of Mediterranean waters off Spain. Solutions are described that were used to quickly combat the turbulence of the waters so the drillship could be operated safely and effectively. The odd condition KCA experienced was caused by what oceanographers refer to as internal wave trains - underwater waves surging against each other from opposite directions.

A control strategy for grid-side converter of DFIG under unbalanced condition based on Dig SILENT/Power Factory

NASA Astrophysics Data System (ADS)

Han, Pingping; Zhang, Haitian; Chen, Lingqi; Zhang, Xiaoan

2018-01-01

The models of doubly fed induction generator (DFIG) and its grid-side converter (GSC) are established under unbalanced grid condition based on DIgSILENT/PowerFactory. According to the mathematical model, the vector equations of positive and negative sequence voltage and current are deduced in the positive sequence synchronous rotating reference frame d-q-0 when the characteristics of the simulation software are considered adequately. Moreover, the reference value of current component of GSC in the positive sequence frame d-q-0 under unbalanced condition can be obtained to improve the traditional control of GSC when the national issue of unbalanced current limits is combined. The simulated results indicate that the control strategy can restrain negative sequence current and the two times frequency power wave of GSC’s ac side effectively. The voltage of DC bus can be maintained a constant to ensure the uninterrupted operation of DFIG under unbalanced grid condition eventually.

Modelling reverse characteristics of power LEDs with thermal phenomena taken into account

NASA Astrophysics Data System (ADS)

Ptak, Przemysław; Górecki, Krzysztof

2016-01-01

This paper refers to modelling characteristics of power LEDs with a particular reference to thermal phenomena. Special attention is paid to modelling characteristics of the circuit protecting the considered device against the excessive value of the reverse voltage and to the description of the temperature influence on optical power. The network form of the worked out model is presented and some results of experimental verification of this model for the selected diodes operating at different cooling conditions are described. The very good agreement between the calculated and measured characteristics is obtained.

Low-noise pulse conditioner

DOEpatents

Bird, David A.

1983-01-01

A low-noise pulse conditioner is provided for driving electronic digital processing circuitry directly from differentially induced input pulses. The circuit uses a unique differential-to-peak detector circuit to generate a dynamic reference signal proportional to the input peak voltage. The input pulses are compared with the reference signal in an input network which operates in full differential mode with only a passive input filter. This reduces the introduction of circuit-induced noise, or jitter, generated in ground referenced input elements normally used in pulse conditioning circuits, especially speed transducer processing circuits.

A high voltage power supply for the AE-C and D low energy electron experiment

NASA Technical Reports Server (NTRS)

Gillis, J. A.

1974-01-01

A description is given of the electrical and mechanical design and operation of high voltage power supplies for space flight use. The supply was used to generate the spiraltron high voltage for low energy electron experiment on AE-C and D. Two versions of the supply were designed and built; one design is referred to as the low power version (AE-C) and the other as the high power version (AE-D). Performance is discussed under all operating conditions.

Liquid rocket actuators and operators. [in spacecraft control systems

NASA Technical Reports Server (NTRS)

1973-01-01

All the types of actuators and associated operators used in booster, upper stage, and spacecraft propulsion and reaction-control systems except for chemical-explosive actuators and turbine actuators are discussed. Discussion of static and dynamic seals, mechanical transmission of motion, and instrumentation is included to the extent that actuator or operator design is affected. Selection of the optimum actuator configuration is discussed for specific application which require a tradeoff study that considers all the relevant factors: available energy sources, load capacity, stroke, speed of response, leakage limitations, environmental conditions, chemical compatibility, storage life and conditions, size, weight, and cost. These factors are interrelated with overall control-system design evaluations that are beyond the scope of this monograph; however, literature references are cited for a detailed review of the general considerations. Perinent advanced-state-of-the-art design concepts are surveyed briefly.

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

Hendron, R.; Engebrecht, C.

The House Simulation Protocol document was developed to track and manage progress toward Building America's multi-year, average whole-building energy reduction research goals for new construction and existing homes, using a consistent analytical reference point. This report summarizes the guidelines for developing and reporting these analytical results in a consistent and meaningful manner for all home energy uses using standard operating conditions.

OECHC Program Review Guide. A Manual of Standard Operating Procedures. Revised.

ERIC Educational Resources Information Center

New York State Education Dept. Albany. Office for the Education of Children with Handicapping Conditions.

The program review guide provides a framework and a source of reference for the monitoring staff of the New York State Education Department's Office for Education of Children with Handicapping Conditions. The manual simultaneously provides a means for school districts, the Boards of Cooperative Educational Services, and other agencies to monitor…

High Speed Cylindrical Roller Bearing Analysis, SKF Computer Program CYBEAN. Volume 1: Analysis

NASA Technical Reports Server (NTRS)

Kleckner, R. J.; Pirvics, J.

1978-01-01

The CYBEAN (CYlindrical BEaring ANalysis) program was created to detail radially loaded, aligned and misaligned Cylindrical roller bearing performance under a variety of operating conditions. The models and associated mathematics used within CYBEAN are described. The user is referred to the material for formulation assumptions and algorithm detail.

77 FR 47123 - Biweekly Notice; Applications and Amendments to Facility Operating Licenses and Combined Licenses...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-07

...-Water Reactors] Steam Generator Tubes'' [Reference 7] and NEI [Nuclear Energy Institute] 97-06, ``Steam... CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared for these... the required structural margins of the SG tubes for both normal and accident conditions. Nuclear...

ROMPS critical design review. Volume 2: Robot module design documentation

NASA Technical Reports Server (NTRS)

Dobbs, M. E.

1992-01-01

The robot module design documentation for the Remote Operated Materials Processing in Space (ROMPS) experiment is compiled. This volume presents the following information: robot module modifications; Easylab commands definitions and flowcharts; Easylab program definitions and flowcharts; robot module fault conditions and structure charts; and C-DOC flow structure and cross references.

Criticality safety strategy for the Fuel Cycle Facility electrorefiner at Argonne National Laboratory, West

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

Mariani, R.D.; Benedict, R.W.; Lell, R.M.

1993-09-01

The Integral Fast Reactor being developed by Argonne National Laboratory (ANL) combines the advantages of metal-fueled, liquid-metal-cooled reactors and a closed fuel cycle. Presently, the Fuel Cycle Facility (FCF) at ANL-West in Idaho Falls, Idaho is being modified to recycle spent metallic fuel from Experimental Breeder Reactor II as part of a demonstration project sponsored by the Department of Energy. A key component of the FCF is the electrorefiner (ER) in which the actinides are separated from the fission products. In the electrorefining process, the metal fuel is anodically dissolved into a high-temperature molten salt and refined uranium or uranium/plutoniummore » products are deposited at cathodes. In this report, the criticality safety strategy for the FCF ER is summarized. FCF ER operations and processes formed the basis for evaluating criticality safety and control during actinide metal fuel refining. In order to show criticality safety for the FCF ER, the reference operating conditions for the ER had to be defined. Normal operating envelopes (NOES) were then defined to bracket the important operating conditions. To keep the operating conditions within their NOES, process controls were identified that can be used to regulate the actinide forms and content within the ER. A series of operational checks were developed for each operation that wig verify the extent or success of an operation. The criticality analysis considered the ER operating conditions at their NOE values as the point of departure for credible and incredible failure modes. As a result of the analysis, FCF ER operations were found to be safe with respect to criticality.« less

A coupled cluster theory with iterative inclusion of triple excitations and associated equation of motion formulation for excitation energy and ionization potential

NASA Astrophysics Data System (ADS)

Maitra, Rahul; Akinaga, Yoshinobu; Nakajima, Takahito

2017-08-01

A single reference coupled cluster theory that is capable of including the effect of connected triple excitations has been developed and implemented. This is achieved by regrouping the terms appearing in perturbation theory and parametrizing through two different sets of exponential operators: while one of the exponentials, involving general substitution operators, annihilates the ground state but has a non-vanishing effect when it acts on the excited determinant, the other is the regular single and double excitation operator in the sense of conventional coupled cluster theory, which acts on the Hartree-Fock ground state. The two sets of operators are solved as coupled non-linear equations in an iterative manner without significant increase in computational cost than the conventional coupled cluster theory with singles and doubles excitations. A number of physically motivated and computationally advantageous sufficiency conditions are invoked to arrive at the working equations and have been applied to determine the ground state energies of a number of small prototypical systems having weak multi-reference character. With the knowledge of the correlated ground state, we have reconstructed the triple excitation operator and have performed equation of motion with coupled cluster singles, doubles, and triples to obtain the ionization potential and excitation energies of these molecules as well. Our results suggest that this is quite a reasonable scheme to capture the effect of connected triple excitations as long as the ground state remains weakly multi-reference.

Emissions and performance of catalysts for gas turbine catalytic combustors. [automobile engines

NASA Technical Reports Server (NTRS)

Anderson, D. N.

1977-01-01

Three noble-metal monolithic catalysts were tested in a 12-cm-dia. combustion test rig to obtain emissions and performance data at conditions simulating the operation of a catalytic combustor for an automotive gas turbine engine. Tests with one of the catalysts at 800 K inlet mixture temperature, 3 x 10 to the 5th Pa pressure, and a reference velocity (catalyst bed inlet velocity) of 10 m/sec demonstrated greater than 99 percent combustion efficiency for reaction temperatures higher than 1300 K. With a reference velocity of 25 m/sec the reaction temperature required to achieve the same combustion-efficiency increased to 1380 K. The exit temperature pattern factors for all three catalysts were below 0.1 when adiabatic reaction temperatures were higher than 1400 K. The highest pressure drop was 4.5 percent at 25 m/sec reference velocity. Nitrogen oxides emissions were less than 0.1 g NO2/kg fuel for all test conditions.

Boundary conditions for the solution of compressible Navier-Stokes equations by an implicit factored method

NASA Technical Reports Server (NTRS)

Shih, T. I.-P.; Smith, G. E.; Springer, G. S.; Rimon, Y.

1983-01-01

A method is presented for formulating the boundary conditions in implicit finite-difference form needed for obtaining solutions to the compressible Navier-Stokes equations by the Beam and Warming implicit factored method. The usefulness of the method was demonstrated (a) by establishing the boundary conditions applicable to the analysis of the flow inside an axisymmetric piston-cylinder configuration and (b) by calculating velocities and mass fractions inside the cylinder for different geometries and different operating conditions. Stability, selection of time step and grid sizes, and computer time requirements are discussed in reference to the piston-cylinder problem analyzed.

Analysis of Lubricant Films in Bearings Under Incipient Failure Conditions.

DTIC Science & Technology

1981-01-01

AFOSUR. 8 2 -34 0 1 ACEjSN NO. lEN’ CATALOG NUMBERFO"R8 0-0010 4 4. TITLE (and Subtitio) S. TYPE OFf REPORT a PERIOD COVERED "Analysis of Lubricant...spectroscopy of the lubricant in operating heavily loaded bearings under so-called elasto- hydrodynamic lubricating conditions. In this type of...Chopper and Blackbody Reference Both interferometers are equipped with choppers of the tuning fork type shown in Fig. 6. The tines are located in front of

Multiple feedback control apparatus for power conditioning equipment

NASA Technical Reports Server (NTRS)

Biess, John (Inventor); Yu, Yuan (Inventor)

1977-01-01

An improved feedback control system to govern the cyclic operation of the power switch of a non-dissipative power conditioning equipment. The apparatus includes two or three control loops working in unison. The first causes the output DC level to be compared with a reference, and the error amplified for control purposes. The second utilizes the AC component of the voltage across the output filter inductor or the current through the output filter capacitor, and the third loop senses the output transients.

Definition of a Robust Supervisory Control Scheme for Sodium-Cooled Fast Reactors

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

Ponciroli, R.; Passerini, S.; Vilim, R. B.

In this work, an innovative control approach for metal-fueled Sodium-cooled Fast Reactors is proposed. With respect to the classical approach adopted for base-load Nuclear Power Plants, an alternative control strategy for operating the reactor at different power levels by respecting the system physical constraints is presented. In order to achieve a higher operational flexibility along with ensuring that the implemented control loops do not influence the system inherent passive safety features, a dedicated supervisory control scheme for the dynamic definition of the corresponding set-points to be supplied to the PID controllers is designed. In particular, the traditional approach based onmore » the adoption of tabulated lookup tables for the set-point definition is found not to be robust enough when failures of the implemented SISO (Single Input Single Output) actuators occur. Therefore, a feedback algorithm based on the Reference Governor approach, which allows for the optimization of reference signals according to the system operating conditions, is proposed.« less

Far-field acoustic data for the Texas ASE, Inc. hush house

NASA Astrophysics Data System (ADS)

Lee, R. A.

1982-04-01

This report supplements AFAMRL-TR-73-110, which describes the data base (NOISEFILE) used in the computer program (NOISEMAP) to predict the community noise exposure resulting from military aircraft operations. The results of field test measurements to define the single-event noise produced on the ground by military aircraft/engines operating in the Texas ASE Inc. hush-house are presented as a function of angle (0 deg to 180 deg from the front of the hush-house) and distance (200 ft to 2500 ft) in various acoustic metrics. All the data are normalized to standard acoustic reference conditions of 59 F temperature and 70% relative humidity. Refer to Volume I of the AFAMRL-TR-73-110 report for discussion of the scope, limitations, and definitions needed to understand and use the data in this report.

Pediatric Audiometry: The Relative Success of Toy and Video Reinforcers.

ERIC Educational Resources Information Center

Doggett, Sheryl; Gans, Donald P.; Stein, Ramona

2000-01-01

An operate conditional technique was used to determine the relative success of toys and video shows as reinforcers for testing the hearing of 28 younger (30-month-old) and 28 older (45-month old) children. Animated toys and video shows for children were equally effective as reinforcers for both age groups. (Contains references.) (Author/CR)

A Big Spatial Data Processing Framework Applying to National Geographic Conditions Monitoring

NASA Astrophysics Data System (ADS)

Xiao, F.

2018-04-01

In this paper, a novel framework for spatial data processing is proposed, which apply to National Geographic Conditions Monitoring project of China. It includes 4 layers: spatial data storage, spatial RDDs, spatial operations, and spatial query language. The spatial data storage layer uses HDFS to store large size of spatial vector/raster data in the distributed cluster. The spatial RDDs are the abstract logical dataset of spatial data types, and can be transferred to the spark cluster to conduct spark transformations and actions. The spatial operations layer is a series of processing on spatial RDDs, such as range query, k nearest neighbor and spatial join. The spatial query language is a user-friendly interface which provide people not familiar with Spark with a comfortable way to operation the spatial operation. Compared with other spatial frameworks, it is highlighted that comprehensive technologies are referred for big spatial data processing. Extensive experiments on real datasets show that the framework achieves better performance than traditional process methods.

E-O Propagation, Signature and System Performance Under Adverse Meteorological Conditions Considering Out-of-Area Operations (La Propagation, la Signature et les performances des Systemes optroniques dans des Conditions Meteorologiques Defavorables, compte Tenu des Operations hors Zone)

DTIC Science & Technology

1998-09-01

distribution CSAS-100-HV 7 m (Surf-2) 0.16-32 .gm PMS2 CSASP-200 Base of Pier 15 m (Surf-1,3) Aerosol size distribution 11.2 m (Surf-2) 0.2-20 pm PMS3 CSASP-100...270 4 180 V ~C2 go 1P-2 PMS3.(6m..) PM.Sl.(12.) PMS2 in.)... ...... Reference -2- ....... .... ..... ............... kn - .2 25 26 27 28 Day number...1 (12 in) are presently available do not allow for a more sophisticated 3 ..... PMS2 (15 m) approach. 2 The horizontal aerosol flux downwind from the

Towards generalised reference condition models for environmental assessment: a case study on rivers in Atlantic Canada.

PubMed

Armanini, D G; Monk, W A; Carter, L; Cote, D; Baird, D J

2013-08-01

Evaluation of the ecological status of river sites in Canada is supported by building models using the reference condition approach. However, geography, data scarcity and inter-operability constraints have frustrated attempts to monitor national-scale status and trends. This issue is particularly true in Atlantic Canada, where no ecological assessment system is currently available. Here, we present a reference condition model based on the River Invertebrate Prediction and Classification System approach with regional-scale applicability. To achieve this, we used biological monitoring data collected from wadeable streams across Atlantic Canada together with freely available, nationally consistent geographic information system (GIS) environmental data layers. For the first time, we demonstrated that it is possible to use data generated from different studies, even when collected using different sampling methods, to generate a robust predictive model. This model was successfully generated and tested using GIS-based rather than local habitat variables and showed improved performance when compared to a null model. In addition, ecological quality ratio data derived from the model responded to observed stressors in a test dataset. Implications for future large-scale implementation of river biomonitoring using a standardised approach with global application are presented.

Comparison Between Simulated and Experimentally Measured Performance of a Four Port Wave Rotor

NASA Technical Reports Server (NTRS)

Paxson, Daniel E.; Wilson, Jack; Welch, Gerard E.

2007-01-01

Performance and operability testing has been completed on a laboratory-scale, four-port wave rotor, of the type suitable for use as a topping cycle on a gas turbine engine. Many design aspects, and performance estimates for the wave rotor were determined using a time-accurate, one-dimensional, computational fluid dynamics-based simulation code developed specifically for wave rotors. The code follows a single rotor passage as it moves past the various ports, which in this reference frame become boundary conditions. This paper compares wave rotor performance predicted with the code to that measured during laboratory testing. Both on and off-design operating conditions were examined. Overall, the match between code and rig was found to be quite good. At operating points where there were disparities, the assumption of larger than expected internal leakage rates successfully realigned code predictions and laboratory measurements. Possible mechanisms for such leakage rates are discussed.

Experimental determination of drift and PM10 cooling tower emissions: Influence of components and operating conditions.

PubMed

Ruiz, J; Kaiser, A S; Lucas, M

2017-11-01

Cooling tower emissions have become an increasingly common hazard to the environment (air polluting, ice formation and salts deposition) and to the health (Legionella disease) in the last decades. Several environmental policies have emerged in recent years limiting cooling tower emissions but they have not prevented an increasing intensity of outbreaks. Since the level of emissions depends mainly on cooling tower component design and the operating conditions, this paper deals with an experimental investigation of the amount of emissions, drift and PM 10 , emitted by a cooling tower with different configurations (drift eliminators and distribution systems) and working under several operating conditions. This objective is met by the measurement of cooling tower source emission parameters by means of the sensitive paper technique. Secondary objectives were to contextualize the observed emission rates according to international regulations. Our measurements showed that the drift rates included in the relevant international standards are significantly higher than the obtained results (an average of 100 times higher) and hence, the environmental problems may occur. Therefore, a revision of the standards is recommended with the aim of reducing the environmental and human health impact. By changing the operating conditions and the distribution system, emissions can be reduced by 52.03% and 82% on average. In the case of drift eliminators, the difference ranges from 18.18% to 98.43% on average. As the emissions level is clearly influenced by operating conditions and components, regulation tests should be referred to default conditions. Finally, guidelines to perform emission tests and a selection criterion of components and conditions for the tested cooling tower are proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of a bacteria-based index of biotic integrity (Ba-IBI) for assessing ecological health of the Three Gorges Reservoir in different operation periods.

PubMed

Li, Yi; Yang, Nan; Qian, Bao; Yang, Zhengjian; Liu, Defu; Niu, Lihua; Zhang, Wenlong

2018-05-30

It is urgently needed to quantitatively assess ecological health of the Three Gorges Reservoir (TGR) when considering its special environmental conditions and temporal variations caused by reservoir operation. This study developed a bacteria-based index of biotic integrity (Ba-IBI) based on sediment samples collected along the TGR in low water level period, impoundment period and sluicing period, respectively. Reference conditions were defined using 8 ecological variables describing the hydromorphology and anthropogenic disturbances around the sites. Five core metrics, including % Acidobacteria, % Gemmatimonadetes, % Geobacter, Methanotroph and Phototroph, were selected after the screening processes. The developed index could clearly discriminate reference and impaired conditions and exhibited significant relationship with environmental parameters according to the redundancy (p < 0.01) and multivariable linear regression analysis (R 2  = 0.76). By implementing Ba-IBI in the TGR, the ecological health of the sampling sites was defined as "Excellent" (25%), "Good" (50%) and "Fair" (25%) separately. The spatial variation of biotic integrity was closely associated with environmental and ecological changes, especially the increase of nutrient concentrations. This study revealed a significant tendency that the ecological health in the low water level and sluicing periods was better than that in the impoundment period, which could be attributed to the hydrodynamic changes due to water level fluctuation. This study provides a comprehensive understanding of ecological health of the TGR in different operation periods and the index offers a guideline for the reservoir regulation in the similar areas. Copyright © 2018. Published by Elsevier B.V.

Designing Robust and Reliable Timestamps for Remote Patient Monitoring.

PubMed

Clarke, Malcolm; Schluter, Paul; Reinhold, Barry; Reinhold, Brian

2015-09-01

Having timestamps that are robust and reliable is essential for remote patient monitoring in order for patient data to have context and to be correlated with other data. However, unlike hospital systems for which guidelines on timestamps are currently provided by HL7 and IHE, remote patient monitoring platforms are: operated in environments where it can be difficult to synchronize with reliable time sources; include devices with simple or no clock; and may store data spanning significant periods before able to upload. Existing guidelines prove inadequate. This paper analyzes the requirements and the operating scenarios of remote patient monitoring platforms and defines a framework to convey information on the conditions under which observations were made by the device and forwarded by the gateway in order for data to be managed appropriately and to include both reference to local time and an underlying continuous reference timeline. We define the timestamp formats of HL7 to denote the different conditions of operation and describe extensions to the existing definition of the HL7 timestamp to differentiate between time local to GMT (+0000) and universal coordinated time or network time protocol time where no geographic time zone is implied (-0000). We further describe how timestamps from devices having only simple or no clocks might be managed reliably by a gateway to provide timestamps that are referenced to local time and an underlying continuous reference timeline. We extend the HL7 message to include information to permit a subsequent receiver of the data to understand the quality of the timestamp and how it has been translated. We present evaluation from deploying a platform for 12 months.

Aircraft gas turbine low-power emissions reduction technology program

NASA Technical Reports Server (NTRS)

Dodds, W. J.; Gleason, C. C.; Bahr, D. W.

1978-01-01

Advanced aircraft turbine engine combustor technology was used to reduce low-power emissions of carbon monoxide and unburned hydrocarbons to levels significantly lower than those which were achieved with current technology. Three combustor design concepts, which were designated as the hot-wall liner concept, the recuperative-cooled liner concept, and the catalyst converter concept, were evaluated in a series of CF6-50 engine size 40 degree-sector combustor rig tests. Twenty-one configurations were tested at operating conditions spanning the design condition which was an inlet temperature and pressure of 422 K and 304 kPa, a reference velocity of 23 m/s and a fuel-air-ration of 10.5 g/kg. At the design condition typical of aircraft turbine engine ground idle operation, the best configurations of all three concepts met the stringent emission goals which were 10, 1, and 4 g/kg for CO, HC, and Nox, respectively.

Performance and diversity of polyvinyl alcohol-degrading bacteria under aerobic and anaerobic conditions.

PubMed

Huang, Jianping; Yang, Shisu; Zhang, Siqi

2016-11-01

To compare the degradation performance and biodiversity of a polyvinyl alcohol-degrading microbial community under aerobic and anaerobic conditions. An anaerobic-aerobic bioreactor was operated to degrade polyvinyl alcohol (PVA) in simulated wastewater. The degradation performance of the bioreactor during sludge cultivation and the microbial communities in each reactor were compared. Both anaerobic and aerobic bioreactors demonstrated high chemical oxygen demand removal efficiencies of 87.5 and 83.6 %, respectively. Results of 16S rDNA sequencing indicated that Proteobacteria dominated in both reactors and that the microbial community structures varied significantly under different operating conditions. Both reactors obviously differed in bacterial diversity from the phyla Planctomycetes, Chlamydiae, Bacteroidetes, and Chloroflexi. Betaproteobacteria and Alphaproteobacteria dominated, respectively, in the anaerobic and aerobic reactors. The anaerobic-aerobic system is suitable for PVA wastewater treatment, and the microbial genetic analysis may serve as a reference for PVA biodegradation.

[Treatment of tuberculous coxitis with special reference to modern surgical therapy].

PubMed

Kessler, P

1985-01-01

The medicamentous therapy of tuberculous coxitis follows the general rules of antituberculous chemotherapy. This treatment should be completed by an operative therapy in every case. The method of radical surgery with sine-plastic, described by Göb in 1980, provides best conditions to highest radicality of this treatment. Between 1980 and 1984 13 patients were operated upon by this method in the Orthopedic Department of the Bad Berka Central Hospital. The results are mainly good. By means of a modification installed by the author a more subtle approach is achieved.

Selected natural attenuation monitoring data, Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington, June 2001

USGS Publications Warehouse

Dinico, Richard Steven

2003-01-01

Previous investigations have shown that natural attenuation and biodegradation of chlorinated volatile organic compounds (CVOCs) are substantial in shallow ground water beneath the 9-acre former landfill at Operable Unit 1 (OU 1), Naval Undersea Warfare Center (NUWC), Division Keyport, Washington. The U.S. Geological Survey (USGS) has continued to monitor ground-water geochemistry to assure that conditions remain favorable for contaminant biodegradation. This report presents the ground-water geochemical and selected CVOC data collected at OU 1 by the USGS during June 11-14, 2001 in support of the long-term monitoring for natural attenuation. Overall, the June 2001 data indicate that redox conditions in the upper aquifer remain favorable for reductive dechlorination of CVOCs because strongly reducing conditions persisted beneath much of the former landfill. Redox conditions in the intermediate aquifer down gradient of the landfill appear to have become more favorable for reductive dechlorination because June 2001 dissolved hydrogen concentrations indicated strongly reducing conditions there for the first time. Although changes in redox conditions were observed at certain wells during 2001, a longer monitoring period is needed to ascertain if phytoremediation activities are affecting the ground-water chemistry. A minor change to future monitoring is proposed. Filtered organic carbon (previously referred to as dissolved, and defined as that which passes through a 0.45-micrometer membrane filter) should be analyzed in the future rather than unfiltered (previously referred to as total) organic carbon because the filtered analysis may be a better measure of bioavailable organic carbon. Unfiltered and filtered organic carbon data were collected during June 2001 for comparison. Filtered organic carbon data collected in the future could be reasonably compared with historical unfiltered organic carbon data by multiplying the historical data by a factor of about 0.9.

Ozonation of the pharmaceutical compound ranitidine: reactivity and kinetic aspects.

PubMed

Rivas, Javier; Gimeno, Olga; Encinas, Angel; Beltrán, Fernando

2009-07-01

Ranitidine has been ozonated under different operating conditions of pH, applied ozone dose, initial ranitidine concentration and presence or absence of free radical inhibitors. Results of ranitidine evolution with time indicate a high reactivity of this compound with molecular ozone. Mineralization levels achieved in the order of 20-25% suggest that the (CH3)2-N-CH2- moiety bonded to the furan ring could be separated from the rest of the ranitidine structure and further mineralized. Only alkaline conditions (pH=11) are capable of increasing TOC conversion up to values close to 70%. Determination of the direct ozonation rate constant for ranitidine by means of competitive kinetics reveals an unacceptable dependence of the aforementioned constant with the reference compound reactivity. It is hypothesised that only reference compounds with reactivity similar to the target species should be used.

Second-order sliding mode controller with model reference adaptation for automatic train operation

NASA Astrophysics Data System (ADS)

Ganesan, M.; Ezhilarasi, D.; Benni, Jijo

2017-11-01

In this paper, a new approach to model reference based adaptive second-order sliding mode control together with adaptive state feedback is presented to control the longitudinal dynamic motion of a high speed train for automatic train operation with the objective of minimal jerk travel by the passengers. The nonlinear dynamic model for the longitudinal motion of the train comprises of a locomotive and coach subsystems is constructed using multiple point-mass model by considering the forces acting on the vehicle. An adaptation scheme using Lyapunov criterion is derived to tune the controller gains by considering a linear, stable reference model that ensures the stability of the system in closed loop. The effectiveness of the controller tracking performance is tested under uncertain passenger load, coupler-draft gear parameters, propulsion resistance coefficients variations and environmental disturbances due to side wind and wet rail conditions. The results demonstrate improved tracking performance of the proposed control scheme with a least jerk under maximum parameter uncertainties when compared to constant gain second-order sliding mode control.

Strength Analysis on Ship Ladder Using Finite Element Method

NASA Astrophysics Data System (ADS)

Budianto; Wahyudi, M. T.; Dinata, U.; Ruddianto; Eko P., M. M.

2018-01-01

In designing the ship’s structure, it should refer to the rules in accordance with applicable classification standards. In this case, designing Ladder (Staircase) on a Ferry Ship which is set up, it must be reviewed based on the loads during ship operations, either during sailing or at port operations. The classification rules in ship design refer to the calculation of the structure components described in Classification calculation method and can be analysed using the Finite Element Method. Classification Regulations used in the design of Ferry Ships used BKI (Bureau of Classification Indonesia). So the rules for the provision of material composition in the mechanical properties of the material should refer to the classification of the used vessel. The analysis in this structure used program structure packages based on Finite Element Method. By using structural analysis on Ladder (Ladder), it obtained strength and simulation structure that can withstand load 140 kg both in static condition, dynamic, and impact. Therefore, the result of the analysis included values of safety factors in the ship is to keep the structure safe but the strength of the structure is not excessive.

Characterisation and optimisation of the new Prompt Gamma-ray Activation Analysis (PGAA) facility at FRM II

NASA Astrophysics Data System (ADS)

Canella, Lea; Kudějová, Petra; Schulze, Ralf; Türler, Andreas; Jolie, Jan

2011-04-01

At the research reactor Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II) a new Prompt Gamma-ray Activation Analysis (PGAA) facility was installed. The instrument was originally built and operating at the spallation source at the Paul Scherrer Institute in Switzerland. After a careful re-design in 2004-2006, the new PGAA instrument was ready for operation at FRM II. In this paper the main characteristics and the current operation conditions of the facility are described. The neutron flux at the sample position can reach up 6.07×1010 [cm-2 s-1], thus the optimisation of some parameters, e.g. the beam background, was necessary in order to achieve a satisfactory analytical sensitivity for routine measurements. Once the optimal conditions were reached, detection limits and sensitivities for some elements, like for example H, B, C, Si, or Pb, were calculated and compared with other PGAA facilities. A standard reference material was also measured in order to show the reliability of the analysis under different conditions at this instrument.

Experimental correlations for transient soot measurement in diesel exhaust aerosol with light extinction, electrical mobility and diffusion charger sensor techniques

NASA Astrophysics Data System (ADS)

Bermúdez, Vicente; Pastor, José V.; López, J. Javier; Campos, Daniel

2014-06-01

A study of soot measurement deviation using a diffusion charger sensor with three dilution ratios was conducted in order to obtain an optimum setting that can be used to obtain accurate measurements in terms of soot mass emitted by a light-duty diesel engine under transient operating conditions. The paper includes three experimental phases: an experimental validation of the measurement settings in steady-state operating conditions; evaluation of the proposed setting under the New European Driving Cycle; and a study of correlations for different measurement techniques. These correlations provide a reliable tool for estimating soot emission from light extinction measurement or from accumulation particle mode concentration. There are several methods and correlations to estimate soot concentration in the literature but most of them were assessed for steady-state operating points. In this case, the correlations are obtained by more than 4000 points measured in transient conditions. The results of the new two correlations, with less than 4% deviation from the reference measurement, are presented in this paper.

Spruce Budworms Handbook: shigometry – a reference guide

Treesearch

Alex L. Shigo; Walter C. Shortle

1985-01-01

This guide explains how to test the condition of living trees or wood products by use of the Shigometer and gives instructions for its use. The guide is in three parts: (1) An introduction on operating principles and applications, (2) an example of the procedure, and (3) a photo guide that gives details on the procedure and background information needed to use it....

Building America House Simulation Protocols

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

Hendron, Robert; Engebrecht, Cheryn

2010-09-01

The House Simulation Protocol document was developed to track and manage progress toward Building America's multi-year, average whole-building energy reduction research goals for new construction and existing homes, using a consistent analytical reference point. This report summarizes the guidelines for developing and reporting these analytical results in a consistent and meaningful manner for all home energy uses using standard operating conditions.

Recent advances in spin-free state-specific and state-universal multi-reference coupled cluster formalisms: A unitary group adapted approach

NASA Astrophysics Data System (ADS)

Maitra, Rahul; Sinha, Debalina; Sen, Sangita; Shee, Avijit; Mukherjee, Debashis

2012-06-01

We present here the formulations and implementations of Mukherjee's State-Specific and State-Universal Multi-reference Coupled Cluster theories, which are explicitly spin free being obtained via the Unitary Group Adapted (UGA) approach, and thus, do not suffer from spin-contamination. We refer to them as UGA-SSMRCC and UGASUMRCC respectively. We propose a new multi-exponential cluster Ansatz analogous to but different from the one suggested by Jeziorski and Monkhorst (JM). Unlike the JM Ansatz, our choice involves spin-free unitary generators for the cluster operators and we replace the traditional exponential structure for the wave-operator by a suitable normal ordered exponential. We sketch the consequences of choosing our Ansatz, which leads to fully spin-free finite power series structure of the direct term of the MRCC equations. The UGA-SUMRCC follows from a suitable hierarchical generation of the cluster amplitudes of increasing rank, while the UGA-SSMRCC requires suitable sufficiency conditions to arrive at a well-defined set of equations for the cluster amplitudes. We discuss two distinct and inequivalent sufficiency conditions and their pros and cons. We also discuss a variant of the UGA-SSMRCC, where the number of cluster amplitudes can be drastically reduced by internal contraction of the two-body inactive cluster amplitudes. These are the most numerous, and thus a spin-free internally contracted description will lead to a high speed-up factor. We refer to this as ICID-UGA-SSMRCC. Essentially the same mathematical manipulations provide us with the UGA-SUMRCC theory as well. Pilot numerical results are presented to indicate the promise and the efficacy of all the three methods.

Analysis of a topping-cycle, aircraft, gas-turbine-engine system which uses cryogenic fuel

NASA Technical Reports Server (NTRS)

Turney, G. E.; Fishbach, L. H.

1984-01-01

A topping-cycle aircraft engine system which uses a cryogenic fuel was investigated. This system consists of a main turboshaft engine that is mechanically coupled (by cross-shafting) to a topping loop, which augments the shaft power output of the system. The thermodynamic performance of the topping-cycle engine was analyzed and compared with that of a reference (conventional) turboshaft engine. For the cycle operating conditions selected, the performance of the topping-cycle engine in terms of brake specific fuel consumption (bsfc) was determined to be about 12 percent better than that of the reference turboshaft engine. Engine weights were estimated for both the topping-cycle engine and the reference turboshaft engine. These estimates were based on a common shaft power output for each engine. Results indicate that the weight of the topping-cycle engine is comparable with that of the reference turboshaft engine.

Study of LH2-fueled topping cycle engine for aircraft propulsion

NASA Technical Reports Server (NTRS)

Turney, G. E.; Fishbach, L. H.

1983-01-01

An analytical investigation was made of a topping cycle aircraft engine system which uses a cryogenic fuel. This system consists of a main turboshaft engine which is mechanically coupled (by cross-shafting) to a topping loop which augments the shaft power output of the system. The thermodynamic performance of the topping cycle engine was analyzed and compared with that of a reference (conventional-type) turboshaft engine. For the cycle operating conditions selected, the performance of the topping cycle engine in terms of brake specific fuel consumption (bsfc) was determined to be about 12 percent better than that of the reference turboshaft engine. Engine weights were estimated for both the topping cycle engine and the reference turboshaft engine. These estimates were based on a common shaft power output for each engine. Results indicate that the weight of the topping cycle engine is comparable to that of the reference turboshaft engine.

Multivariable control altitude demonstration on the F100 turbofan engine

NASA Technical Reports Server (NTRS)

Lehtinen, B.; Dehoff, R. L.; Hackney, R. D.

1979-01-01

The F100 Multivariable control synthesis (MVCS) program, was aimed at demonstrating the benefits of LGR synthesis theory in the design of a multivariable engine control system for operation throughout the flight envelope. The advantages of such procedures include: (1) enhanced performance from cross-coupled controls, (2) maximum use of engine variable geometry, and (3) a systematic design procedure that can be applied efficiently to new engine systems. The control system designed, under the MVCS program, for the Pratt & Whitney F100 turbofan engine is described. Basic components of the control include: (1) a reference value generator for deriving a desired equilibrium state and an approximate control vector, (2) a transition model to produce compatible reference point trajectories during gross transients, (3) gain schedules for producing feedback terms appropriate to the flight condition, and (4) integral switching logic to produce acceptable steady-state performance without engine operating limit exceedance.

Ocular diseases and nonbattle injuries seen at a tertiary care medical center during the Global War on Terrorism.

PubMed

Psolka, Maximilian; Bower, Kraig S; Brooks, Dain B; Donnelly, Steven J; Iglesias, Melissa; Rimm, William R; Ward, Thomas P

2007-05-01

We retrospectively reviewed the records of 107 U.S. military personnel referred to the Walter Reed Army Medical Center ophthalmology service with eye diseases and nonbattle injuries diagnosed during Operation Enduring Freedom and Operation Iraqi Freedom. Ocular diseases and nonbattle injuries ranged from minor to vision-threatening, represented a broad variety of conditions, and required the expertise of a number of ophthalmic subspecialists. The most common diagnoses were uveitis (13.1%), retinal detachment (11.2%), infectious keratitis (4.7%), and choroidal neovascularization (4.7%). Eighty-four patients (78.5%) met Army retention standards and were returned to duty. Twenty patients (18.7%) were referred to a medical evaluation board, seven (6.5%) of whom failed to meet retention standards for eye and vision; the retention status of three patients (2.8%) remains to be determined.

Displacement sensing system and method

DOEpatents

VunKannon, Jr., Robert S

2006-08-08

A displacement sensing system and method addresses demanding requirements for high precision sensing of displacement of a shaft, for use typically in a linear electro-dynamic machine, having low failure rates over multi-year unattended operation in hostile environments. Applications include outer space travel by spacecraft having high-temperature, sealed environments without opportunity for servicing over many years of operation. The displacement sensing system uses a three coil sensor configuration, including a reference and sense coils, to provide a pair of ratio-metric signals, which are inputted into a synchronous comparison circuit, which is synchronously processed for a resultant displacement determination. The pair of ratio-metric signals are similarly affected by environmental conditions so that the comparison circuit is able to subtract or nullify environmental conditions that would otherwise cause changes in accuracy to occur.

High heat transfer oxidizer heat exchanger design and analysis. [RL10-2B engine

NASA Technical Reports Server (NTRS)

Kmiec, Thomas D.; Kanic, Paul G.; Peckham, Richard J.

1987-01-01

The RL10-2B engine, a derivative of the RL10, is capable of multimode thrust operation. This engine operates at two low thrust levels: tank head idle (THI), which is approximately 1 to 2% of full thrust, and pumped idle (PI), which is 10% of full thrust. Operation at THI provides vehicle propellant settling thrust and efficient engine thermal conditioning; PI operation provides vehicle tank pre-pressurization and maneuver thrust for low-g deployment. Stable combustion of the RL10-2B engine during the low thrust operating modes can be accomplished by using a heat exchanger to supply gaseous oxygen to the propellant injector. The oxidizer heat exchanger (OHE) vaporizes the liquid oxygen using hydrogen as the energy source. The design, concept verification testing and analysis for such a heat exchanger is discussed. The design presented uses a high efficiency compact core to vaporize the oxygen, and in the self-contained unit, attenuates any pressure and flow oscillations which result from unstable boiling in the core. This approach is referred to as the high heat transfer design. An alternative approach which prevents unstable boiling of the oxygen by limiting the heat transfer is referred to as the low heat transfer design and is reported in Pratt & Whitney report FR-19135-2.

System and method of detecting cavitation in pumps

DOEpatents

Lu, Bin; Sharma, Santosh Kumar; Yan, Ting; Dimino, Steven A.

2017-10-03

A system and method for detecting cavitation in pumps for fixed and variable supply frequency applications is disclosed. The system includes a controller having a processor programmed to repeatedly receive real-time operating current data from a motor driving a pump, generate a current frequency spectrum from the current data, and analyze current data within a pair of signature frequency bands of the current frequency spectrum. The processor is further programmed to repeatedly determine fault signatures as a function of the current data within the pair of signature frequency bands, repeatedly determine fault indices based on the fault signatures and a dynamic reference signature, compare the fault indices to a reference index, and identify a cavitation condition in a pump based on a comparison between the reference index and a current fault index.

Adaptive fuzzy logic controller with direct action type structures for InnoSAT attitude control system

NASA Astrophysics Data System (ADS)

Bakri, F. A.; Mashor, M. Y.; Sharun, S. M.; Bibi Sarpinah, S. N.; Abu Bakar, Z.

2016-10-01

This study proposes an adaptive fuzzy controller for attitude control system (ACS) of Innovative Satellite (InnoSAT) based on direct action type structure. In order to study new methods used in satellite attitude control, this paper presents three structures of controllers: Fuzzy PI, Fuzzy PD and conventional Fuzzy PID. The objective of this work is to compare the time response and tracking performance among the three different structures of controllers. The parameters of controller were tuned on-line by adjustment mechanism, which was an approach similar to a PID error that could minimize errors between actual and model reference output. This paper also presents a Model References Adaptive Control (MRAC) as a control scheme to control time varying systems where the performance specifications were given in terms of the reference model. All the controllers were tested using InnoSAT system under some operating conditions such as disturbance, varying gain, measurement noise and time delay. In conclusion, among all considered DA-type structures, AFPID controller was observed as the best structure since it outperformed other controllers in most conditions.

RANS Simulation (Rotating Reference Frame Model [RRF]) of Single Full Scale DOE RM1 MHK Turbine

DOE Data Explorer

Javaherchi, Teymour; Stelzenmuller, Nick; Aliseda, Alberto

2013-04-10

Attached are the .cas and .dat files for the Reynolds Averaged Navier-Stokes (RANS) simulation of a single full scale DOE RM1 turbine implemented in ANSYS FLUENT CFD-package. In this case study taking advantage of the symmetry of the DOE RM1 geometry, only half of the geometry is modeled using (Single) Rotating Reference Frame model [RRF]. In this model RANS equations, coupled with k-\\omega turbulence closure model, are solved in the rotating reference frame. The actual geometry of the turbine blade is included and the turbulent boundary layer along the blade span is simulated using wall-function approach. The rotation of the blade is modeled by applying periodic boundary condition to sets of plane of symmetry. This case study simulates the performance and flow field in both the near and far wake of the device at the desired operating conditions. The results of these simulations showed good agreement to the only publicly available numerical simulation of the device done in the NREL. Please see the attached paper.

Overview of experimental preparation for the ITER-Like Wall at JET

NASA Astrophysics Data System (ADS)

Jet Efda Contributors Brezinsek, S.; Fundamenski, W.; Eich, T.; Coad, J. P.; Giroud, C.; Huber, A.; Jachmich, S.; Joffrin, E.; Krieger, K.; McCormick, K.; Lehnen, M.; Loarer, T.; de La Luna, E.; Maddison, G.; Matthews, G. F.; Mertens, Ph.; Nunes, I.; Philipps, V.; Riccardo, V.; Rubel, M.; Stamp, M. F.; Tsalas, M.

2011-08-01

Experiments in JET with carbon-based plasma-facing components have been carried out in preparation of the ITER-Like Wall with beryllium main chamber and full tungsten divertor. The preparatory work was twofold: (i) development of techniques, which ensure safe operation with the new wall and (ii) provision of reference plasmas, which allow a comparison of operation with carbon and metallic wall. (i) Compatibility with the W divertor with respect to energy loads could be achieved in N2 seeded plasmas at high densities and low temperatures, finally approaching partial detachment, with only moderate confinement reduction of 10%. Strike-point sweeping increases the operational space further by re-distributing the load over several components. (ii) Be and C migration to the divertor has been documented with spectroscopy and QMBs under different plasma conditions providing a database which will allow a comparison of the material transport to remote areas with metallic walls. Fuel retention rates of 1.0-2.0 × 1021 D s-1 were obtained as references in accompanied gas balance studies.

A Novel Sensor Based on a Single-Pixel Microwave Radiometer for Warm Object Counting: Concept Validation and IoT Perspectives

PubMed Central

Alimenti, Federico; Bonafoni, Stefania; Roselli, Luca

2017-01-01

Controlled measurements by a low-cost single-pixel microwave radiometer operating at 12.65 GHz were carried out to assess the detection and counting capability for targets warmer than the surroundings. The adopted reference test targets were pre-warmed water and oil; and a hand, both naked and wearing a glove. The results showed the reliability of microwave radiometry for counting operations under controlled conditions, and its effectiveness at detecting even warm targets masked by unheated dielectric layers. An electromagnetic model describing the scenario sensed by the radiometer antenna is proposed, and comparison with the experimental observations shows a good agreement. The measurements prove that reliable counting is enabled by an antenna temperature increment, for each target sample added, of around 1 K. Starting from this value, an analysis of the antenna filling factor was performed to provide an instrument useful for evaluating real applicability in many practical situations. This study also allows the direct people counting problem to be addressed, providing preliminary operational indications, reference numbers and experimental validation. PMID:28613264

Autoheated thermophilic aerobic digestion

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

Deeny, K.; Hahn, H.; Leonhard, D.

1991-10-01

Autothermal thermophilic aerobic digestion (ATAD) is first and foremost a digestion process, the primary purpose of which is to decompose a portion of the waste organic solids generated from wastewater treatment. As a result of the high operating temperature, digestion is expected to occur within a short time period (6 days) and accomplish a high degree of pathogen reduction. ATAD systems are two-stage aerobic digestion processes that operate under thermophilic temperature conditions (40 to 80C) without supplemental heat. Like composting, the systems rely on the conservation of heat released during digestion itself to attain and sustain the desired operating temperature.more » Typical ATAD systems operate at 55C and may reach temperatures of 60 to 65C in the second-stage reactor. Perhaps because of the high operating temperature, this process has been referred to as Liquid Composting.' Major advantages associated with thermophilic operation include high biological reaction rates and a substantial degree of pathogen reduction.« less

Apollo-Soyuz test project. Operations handbook command/service/docking modules (CSM 119/DM 1): Operational procedures reference issue

NASA Technical Reports Server (NTRS)

1974-01-01

Operational and configuration checks for the Apollo-Soyuz Test Project are presented. The checks include: backup crew prelaunch, prime crew prelaunch, boost and insertion, G and C reference data, G and N reference modes, rendezvous, navigation, Apollo-Soyuz operations, abort procedures, and emergency procedures.

CFD Code Survey for Thrust Chamber Application

NASA Technical Reports Server (NTRS)

Gross, Klaus W.

1990-01-01

In the quest fo find analytical reference codes, responses from a questionnaire are presented which portray the current computational fluid dynamics (CFD) program status and capability at various organizations, characterizing liquid rocket thrust chamber flow fields. Sample cases are identified to examine the ability, operational condition, and accuracy of the codes. To select the best suited programs for accelerated improvements, evaluation criteria are being proposed.

Novel spectrometers for environmental dose rate monitoring.

PubMed

Kessler, P; Behnke, B; Dabrowski, R; Dombrowski, H; Röttger, A; Neumaier, S

2018-07-01

A new generation of dosemeters, based on the scintillators LaBr 3 , CeBr 3 and SrI 2 , read out with conventional photomultipliers, to be used in the field of environmental gamma-radiation monitoring, was investigated. The main features of these new instruments and especially their outdoor performance, studied by long-term investigations under real weather conditions, are presented. The systems were tested at the reference sites for environmental radiation of the Physikalisch-Technische Bundesanstalt. The measurements are compared with that of well characterized classical dose rate reference instruments to demonstrate the suitability of new spectrometers for environmental dose rate monitoring even in adverse weather conditions. Their potential to replace the (mainly Geiger Müller based) dose rate meters operated in about 5000 European early waning network stations as well as in environmental radiation monitoring in general is shown. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

A real-time posture monitoring method for rail vehicle bodies based on machine vision

NASA Astrophysics Data System (ADS)

Liu, Dongrun; Lu, Zhaijun; Cao, Tianpei; Li, Tian

2017-06-01

Monitoring vehicle operation conditions has become significantly important in modern high-speed railway systems. However, the operational impact of monitoring the roll angle of vehicle bodies has principally been limited to tilting trains, while few studies have focused on monitoring the running posture of vehicle bodies during operation. We propose a real-time posture monitoring method to fulfil real-time monitoring requirements, by taking rail surfaces and centrelines as detection references. In realising the proposed method, we built a mathematical computational model based on space coordinate transformations to calculate attitude angles of vehicles in operation and vertical and lateral vibration displacements of single measuring points. Moreover, comparison and verification of reliability between system and field results were conducted. Results show that monitoring of the roll angles of car bodies obtained through the system exhibit variation trends similar to those converted from the dynamic deflection of bogie secondary air springs. The monitoring results of two identical conditions were basically the same, highlighting repeatability and good monitoring accuracy. Therefore, our monitoring results were reliable in reflecting posture changes in running railway vehicles.

Patient-specific biomechanical model of hypoplastic left heart to predict post-operative cardio-circulatory behaviour.

PubMed

Cutrì, Elena; Meoli, Alessio; Dubini, Gabriele; Migliavacca, Francesco; Hsia, Tain-Yen; Pennati, Giancarlo

2017-09-01

Hypoplastic left heart syndrome is a complex congenital heart disease characterised by the underdevelopment of the left ventricle normally treated with a three-stage surgical repair. In this study, a multiscale closed-loop cardio-circulatory model is created to reproduce the pre-operative condition of a patient suffering from such pathology and virtual surgery is performed. Firstly, cardio-circulatory parameters are estimated using a fully closed-loop cardio-circulatory lumped parameter model. Secondly, a 3D standalone FEA model is build up to obtain active and passive ventricular characteristics and unloaded reference state. Lastly, the 3D model of the single ventricle is coupled to the lumped parameter model of the circulation obtaining a multiscale closed-loop pre-operative model. Lacking any information on the fibre orientation, two cases were simulated: (i) fibre distributed as in the physiological right ventricle and (ii) fibre as in the physiological left ventricle. Once the pre-operative condition is satisfactorily simulated for the two cases, virtual surgery is performed. The post-operative results in the two cases highlighted similar hemodynamic behaviour but different local mechanics. This finding suggests that the knowledge of the patient-specific fibre arrangement is important to correctly estimate the single ventricle's working condition and consequently can be valuable to support clinical decision. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Synchronized Phasor Data for Analyzing Wind Power Plant Dynamic Behavior and Model Validation

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

Wan, Y. H.

2013-01-01

The U.S. power industry is undertaking several initiatives that will improve the operations of the power grid. One of those is the implementation of 'wide area measurements' using phasor measurement units (PMUs) to dynamically monitor the operations and the status of the network and provide advanced situational awareness and stability assessment. This project seeks to obtain PMU data from wind power plants and grid reference points and develop software tools to analyze and visualize synchrophasor data for the purpose of better understanding wind power plant dynamic behaviors under normal and contingency conditions.

Theoretical Study of the Conditions of Maximum Manifestation of the Error Due to Inhomogeneity of Thermocouple Legs

NASA Astrophysics Data System (ADS)

Liu, Zhigang; Song, Wenguang; Kochan, Orest; Mykyichuk, Mykola; Jun, Su

2017-07-01

The method of theoretical analysis of temperature ranges for the maximum manifestation of the error due to acquired thermoelectric inhomogeneity of thermocouple legs is proposed in this paper. The drift function of the reference function of a type K thermocouples in a ceramic insulation, that consisted of 1.2 mm diameter thermoelements after their exposure to 800°C for 10 000 h in an oxidizing atmosphere (air), is analyzed. The method takes into account various operating conditions to determine the optimal conditions for studying inhomogeneous thermocouples. The method can be applied for other types of thermocouples when taking into account their specific characteristics and the conditions that they have been exposed to.

Influence of Compression Ratio on High Load Performance and Knock Behavior for Gasoline Port-Fuel Injection, Natural Gas Direct Injection and Blended Operation in a Spark Ignition Engine

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

Pamminger, Michael; Sevik, James; Scarcelli, Riccardo

Natural Gas (NG) is an alternative fuel which has attracted a lot of attention recently, in particular in the US due to shale gas availability. The higher hydrogen-to-carbon (H/C) ratio, compared to gasoline, allows for decreasing carbon dioxide emissions throughout the entire engine map. Furthermore, the high knock resistance of NG allows increasing the efficiency at high engine loads compared to fuels with lower knock resistance. NG direct injection (DI) allows for fuel to be added after intake valve closing (IVC) resulting in an increase in power density compared to an injection before IVC. Steady-state engine tests were performed onmore » a single-cylinder research engine equipped with gasoline (E10) port-fuel injection (PFI) and NG DI to allow for in-cylinder blending of both fuels. Knock investigations were performed at two discrete compression ratios (CR), 10.5 and 12.5. Operating conditions span mid-load, wide-open-throttle and boosted conditions, depending on the knock response of the fuel blend. Blended operation was performed using E10 gasoline and NG. An additional gasoline type fuel (E85) with higher knock resistance than E10 was used as a high-octane reference fuel, since the octane rating of E10-NG fuel blends is unknown. Spark timing was varied at different loads under stoichiometric conditions in order to study the knock response as well as the effects on performance and efficiency. As anticipated, results suggest that the knock resistance can be increased significantly by increasing the NG amount. Comparing the engine operation with the least knock resistant fuel, E10 PFI, and the fuel blend with the highest knock resistance, 75% NG DI, shows an increase in indicated mean effective pressure of about 9 bar at CR 12.5. The usage of reference fuels with known knock characteristics allowed an assessment of knock characteristic of intermediate E10-NG blend levels. Mathematical correlations were developed allowing characterizing the occurrence of knocking combustion by using the Livengood-Wu knock integral. For most of the fueling strategies and operating conditions, the mathematical correlations show good agreement when compared to experimental data.« less

Assessment Regarding Impact of Atmospheric Conditions on Space Shuttle Launch Delays

NASA Technical Reports Server (NTRS)

Johnson D. L.; Pearson, S. D.; Vaughan, W. W.; Batts, G. W.

1998-01-01

The atmospheric environment definition has played a key role in the development and operation of the NASA Space Shuttle as it has in other NASA Space Vehicle Programs. The objective of any definition of natural environment design requirements for a space vehicle development is to insure that the vehicle will perform safely and in a timely manner relative to the mission(s) for which the vehicle is being developed. The NASA Space Shuttle has enjoyed the longest tenure of any Space Vehicle from an operational standpoint. As such, it has provided a wealth of information on many engineering aspects of a Space Vehicle plus the influence of the atmosphere on operational endeavors. The atmospheric environment associated with the NASA Space Shuttle launches at the NASA Kennedy Space Center in Florida has been reviewed and studied over the entire NASA Space Shuttle flight history. The results of the analysis of atmospheric environment related launch delays relative to other sources of launch delays has been assessed. This paper will provide a summary of those conditions as well as mission analysis examples focused on atmospheric constraints for launch. Atmospheric conditions associated with NASA Space Shuttle launch delays will be presented to provide a reference as to the type conditions experienced which have mainly caused the delays.

Establishing physico-chemical reference conditions in Mediterranean streams according to the European Water Framework Directive.

PubMed

Sánchez-Montoya, María del Mar; Arce, Maria Isabel; Vidal-Abarca, María Rosario; Suárez, María Luisa; Prat, Narcís; Gómez, Rosa

2012-05-01

Type-specific physico-chemical reference conditions are required for the assessment of ecological status in the Water Framework Directive context, similarly to the biological and hydro-morphological elements. This directive emphasises that natural variability of quality elements in high status (reference condition) needs to be quantified. Mediterranean streams often present a marked seasonal pattern in hydrological, biological and geochemical processes which could affect physico-chemical reference conditions. This study establishes general physico-chemical reference conditions (oxygenation, nutrient, salinity and acidification conditions) for different Mediterranean stream types. 116 potential reference sites located in 23 Mediterranean catchments in Spain were sampled in spring, summer and autumn in 2003. All sites were subjected to a screening method for the selection of reference sites in Mediterranean streams (Mediterranean Reference Criteria) and classified using a pre-established stream typology that establishes five different stream types (temporary streams, evaporite-calcareous at medium altitude, siliceous headwaters, calcareous headwaters and large watercourses). Reference conditions (reference value and reference threshold equivalents to high-good class boundary) were calculated using two different methods according to the availability of reference sites: the reference site 75th percentile approach of all reference sites and the 25th percentile of the population approach. The majority of the studied potential reference sites (76 out of 116) were selected as reference sites. Regarding type-specific reference conditions, only siliceous headwaters could be considered different from the rest of stream types because lower conductivity and pH. All reference stream types presented seasonal differences as regards some parameters, except for temporary streams due to the high natural variation of this stream type. For those parameters which presented seasonal differences in a specific stream type, the least restrictive values were proposed as reference conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Electromagnetic Pulse (EMP) survey of the Louisiana State Emergency Operating Center, Baton Rouge, Louisiana

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

Crutcher, R.I.; Buchanan, M.E.; Jones, R.W.

1989-08-01

The purpose of this report is to develop an engineering design package to protect the federal Emergency Management Agency (FEMA) National Radio System (FNARS) facilities from the effects of high-altitude electromagnetic pulses (HEMP). This report refers to the Louisiana State Emergency Operating Center (EOC) in Baton Rouge, Louisiana. This report addresses electromagnetic pulse (EMP) effects only, and disregards any condition in which radiation effects may be a factor. It has been established that, except for the source region of a surface burst, EMP effects of high-altitude bursts are more severe than comparable detonations in either air or surface regions. Anymore » system hardened to withstand the more extreme EMP environment will survive the less severe conditions. The threatening environment will therefore be limited to HEMP situations. 76 figs., 2 tabs.« less

Reducing Conservatism in Aircraft Engine Response Using Conditionally Active Min-Max Limit Regulators

NASA Technical Reports Server (NTRS)

May, Ryan D.; Garg, Sanjay

2012-01-01

Current aircraft engine control logic uses a Min-Max control selection structure to prevent the engine from exceeding any safety or operational limits during transients due to throttle commands. This structure is inherently conservative and produces transient responses that are slower than necessary. In order to utilize the existing safety margins more effectively, a modification to this architecture is proposed, referred to as a Conditionally Active (CA) limit regulator. This concept uses the existing Min-Max architecture with the modification that limit regulators are active only when the operating point is close to a particular limit. This paper explores the use of CA limit regulators using a publicly available commercial aircraft engine simulation. The improvement in thrust response while maintaining all necessary safety limits is demonstrated in a number of cases.

40 CFR 63.126 - Transfer operations provisions-reference control technology.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Transfer operations provisions-reference control technology. 63.126 Section 63.126 Protection of Environment ENVIRONMENTAL PROTECTION... Wastewater § 63.126 Transfer operations provisions—reference control technology. (a) For each Group 1...

40 CFR 63.126 - Transfer operations provisions-reference control technology.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Transfer operations provisions-reference control technology. 63.126 Section 63.126 Protection of Environment ENVIRONMENTAL PROTECTION... Wastewater § 63.126 Transfer operations provisions—reference control technology. (a) For each Group 1...

40 CFR 63.126 - Transfer operations provisions-reference control technology.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Transfer operations provisions-reference control technology. 63.126 Section 63.126 Protection of Environment ENVIRONMENTAL PROTECTION... Wastewater § 63.126 Transfer operations provisions—reference control technology. (a) For each Group 1...

40 CFR 63.126 - Transfer operations provisions-reference control technology.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Transfer operations provisions-reference control technology. 63.126 Section 63.126 Protection of Environment ENVIRONMENTAL PROTECTION... Wastewater § 63.126 Transfer operations provisions—reference control technology. (a) For each Group 1...

Computational Evaluation of Inlet Distortion on an Ejector Powered Hybrid Wing Body at Takeoff and Landing Conditions

NASA Technical Reports Server (NTRS)

Tompkins, Daniel M.; Sexton, Matthew R.; Mugica, Edward A.; Beyar, Michael D.; Schuh, Michael J.; Stremel, Paul M.; Deere, Karen A.; McMillin, Naomi; Carter, Melissa B.

2016-01-01

Due to the aft, upper surface engine location on the Hybrid Wing Body (HWB) planform, there is potential to shed vorticity and separated wakes into the engine when the vehicle is operated at off-design conditions and corners of the envelope required for engine and airplane certification. CFD simulations were performed of the full-scale reference propulsion system, operating at a range of inlet flow rates, flight speeds, altitudes, angles of attack, and angles of sideslip to identify the conditions which produce the largest distortion and lowest pressure recovery. Pretest CFD was performed by NASA and Boeing, using multiple CFD codes, with various turbulence models. These data were used to make decisions regarding model integration, characterize inlet flow distortion patterns, and help define the wind tunnel test matrix. CFD was also performed post-test; when compared with test data, it was possible to make comparisons between measured model-scale and predicted full-scale distortion levels. This paper summarizes these CFD analyses.

What learning theories can teach us in designing neurofeedback treatments

PubMed Central

Strehl, Ute

2014-01-01

Popular definitions of neurofeedback point out that neurofeedback is a process of operant conditioning which leads to self-regulation of brain activity. Self-regulation of brain activity is considered to be a skill. The aim of this paper is to clarify that not only operant conditioning plays a role in the acquisition of this skill. In order to design the learning process additional references have to be derived from classical conditioning, two-process-theory and in particular from skill learning and research into motivational aspects. The impact of learning by trial and error, cueing of behavior, feedback, reinforcement, and knowledge of results as well as transfer of self-regulation skills into everyday life will be analyzed in this paper. In addition to these learning theory basics this paper tries to summarize the knowledge about acquisition of self-regulation from neurofeedback studies with a main emphasis on clinical populations. As a conclusion it is hypothesized that learning to self-regulate has to be offered in a psychotherapeutic, i.e., behavior therapy framework. PMID:25414659

What learning theories can teach us in designing neurofeedback treatments.

PubMed

Strehl, Ute

2014-01-01

Popular definitions of neurofeedback point out that neurofeedback is a process of operant conditioning which leads to self-regulation of brain activity. Self-regulation of brain activity is considered to be a skill. The aim of this paper is to clarify that not only operant conditioning plays a role in the acquisition of this skill. In order to design the learning process additional references have to be derived from classical conditioning, two-process-theory and in particular from skill learning and research into motivational aspects. The impact of learning by trial and error, cueing of behavior, feedback, reinforcement, and knowledge of results as well as transfer of self-regulation skills into everyday life will be analyzed in this paper. In addition to these learning theory basics this paper tries to summarize the knowledge about acquisition of self-regulation from neurofeedback studies with a main emphasis on clinical populations. As a conclusion it is hypothesized that learning to self-regulate has to be offered in a psychotherapeutic, i.e., behavior therapy framework.

Some theoretical considerations of longitudinal stability in power-on flight with special reference to wind-tunnel testing, November 1942

NASA Technical Reports Server (NTRS)

Donlan, C. J.

1976-01-01

Some problems relating to longitudinal stability in power-on flight are considered. A derivation is included which shows that, under certain conditions, the rate of change of the pitching moment coefficient with lift coefficient as obtained in wind tunnel tests simulating constant power operation is directly proportional to one of the indices of stability commonly associated with flight analysis, (the slope of the curve relating the elevator angle for trim and lift coefficient). The necessity of analyzing power-on wind tunnel data for trim conditions is emphasized, and a method is provided for converting data obtained from constant thrust tests to simulated constant throttle flight conditions.

Simulation of an offshore wind farm using fluid power for centralized electricity generation

NASA Astrophysics Data System (ADS)

Jarquin-Laguna, A.

2016-09-01

A centralized approach for electricity generation within a wind farm is explored through the use of fluid power technology. This concept considers a new way of generation, collection and transmission of wind energy inside a wind farm, in which electrical conversion does not occur during any intermediate conversion step before the energy has reached the offshore central platform. A numerical model was developed to capture the relevant physics from the dynamic interaction between different turbines coupled to a common hydraulic network and controller. This paper presents two examples of the time-domain simulation results for an hypothetical hydraulic wind farm subject to turbulent wind conditions. The performance and operational parameters of individual turbines are compared with those of a reference wind farm with conventional technology turbines, using the same wind farm layout and environmental conditions. For the presented case study, results indicate that the individual wind turbines are able to operate within operational limits with the current pressure control concept. Despite the stochastic turbulent wind input and wake effects, the hydraulic wind farm is able to produce electricity with reasonable performance in both below and above rated conditions.

A CFD model for biomass fast pyrolysis in fluidized-bed reactors

NASA Astrophysics Data System (ADS)

Xue, Qingluan; Heindel, T. J.; Fox, R. O.

2010-11-01

A numerical study is conducted to evaluate the performance and optimal operating conditions of fluidized-bed reactors for fast pyrolysis of biomass to bio-oil. A comprehensive CFD model, coupling a pyrolysis kinetic model with a detailed hydrodynamics model, is developed. A lumped kinetic model is applied to describe the pyrolysis of biomass particles. Variable particle porosity is used to account for the evolution of particle physical properties. The kinetic scheme includes primary decomposition and secondary cracking of tar. Biomass is composed of reference components: cellulose, hemicellulose, and lignin. Products are categorized into groups: gaseous, tar vapor, and solid char. The particle kinetic processes and their interaction with the reactive gas phase are modeled with a multi-fluid model derived from the kinetic theory of granular flow. The gas, sand and biomass constitute three continuum phases coupled by the interphase source terms. The model is applied to investigate the effect of operating conditions on the tar yield in a fluidized-bed reactor. The influence of various parameters on tar yield, including operating temperature and others are investigated. Predicted optimal conditions for tar yield and scale-up of the reactor are discussed.

Comparison of Measures of Vibration Affecting Occupants of Military Vehicles

DTIC Science & Technology

1986-12-01

8217 ,, l I WES equipment 27. The WES equipment consisted of a battery operated absorbed power ( ABS -PW) meter with signal conditioning...West Germany. These will be referred to as the ISO ride meter and the ABS -PWR ridemeter, respectively. The first implemented the vibration measure...the ABS -PWR algorithms were used with each acceleration signal source (analog and digital) to provide a comprehensive basis for comparing the vibration

Fifty-eighth Christmas Bird Count. 166. Ocean City, Md

USGS Publications Warehouse

Keough, J.R.; Thompson, T.A.; Guntenspergen, G.R.; Wilcox, D.A.

1999-01-01

Gauging the impact of manipulative activities, such as rehabilitation or management, on wetlands requires having a notion of the unmanipulated condition as a reference. An understanding of the reference condition requires knowledge of dominant factors influencing ecosystem processes and biological communities. In this paper, we focus on natural physical factors (conditions and processes) that drive coastal wetland ecosystems of the Laurentian Great Lakes. Great Lakes coastal wetlands develop under conditions of large-lake hydrology and disturbance imposed at a hierarchy of spatial and temporal scales and contain biotic communities adapted to unstable and unpredictable conditions. Coastal wetlands are configured along a continuum of hydrogeomorphic types: open coastal wetlands, drowned river mouth and flooded delta wetlands, and protected wetlands, each developing distinct ecosystem properties and biotic communities. Hydrogeomorphic factors associated with the lake and watershed operate at a hierarchy of scales: a) local and short-term (seiches and ice action), b) watershed / lakewide / annual (seasonal water- level change), and c) larger or year-to-year and longer ( regional and/or greater than one-year). Other physical factors include the unique water quality features of each lake. The aim of this paper is to provide scientists and managers with a framework for considering regional and site-specific geomorphometry and a hierarchy of physical processes in planning management and conservation projects.

Hydrogeomorphic factors and ecosystem responses in coastal wetlands of the Great Lakes

USGS Publications Warehouse

Keough, Janet R.; Thompson, Todd A.; Guntenspergen, Glenn R.; Wilcox, Douglas A.

1999-01-01

Gauging the impact of manipulative activities, such as rehabilitation or management, on wetlands requires having a notion of the unmanipulated condition as a reference. And understanding of the reference condition requires knowledge of dominant factors influencing ecosystem processes and biological communities. In this paper, we focus on natural physical factors (conditions and processes) that drive coastal wetland ecosystems of the Laurentian Great Lakes. Great Lakes coastal wetlands develop under conditions of large-lake hydrology and disturbance imposed at a hiearchy of spatial and temporal scales and contain biotic communities adapted to unstable and unpredictable conditions. Coastal wetlands are configured along a continuum of hydrogeomorphic types: open coastal wetlands, drowned river mouth and flooded delta wetlands, and protected wetlands, each developing distinct ecosystem propertics and biotic communities. Hydrogeomorphic factors associated with the lake and watershed operate at a hierarchy of scales: a) local and short-term (seiches and ice action), b) watershed / lakewide / annual (seasonal water-level change), and c) larger or year-to-year and longer (regional and/or greater than one-year). Other physical factors include the unique water quality features of each lake. The aim of this paper is to provide scientists and managers with a framework for considering regional and site-specific geomorphometry and a hierarchy of physical processes in planning management and conservation projects.

Adaptive Control of a Utility-Scale Wind Turbine Operating in Region 3

NASA Technical Reports Server (NTRS)

Frost, Susan A.; Balas, Mark J.; Wright, Alan D.

2009-01-01

Adaptive control techniques are well suited to nonlinear applications, such as wind turbines, which are difficult to accurately model and which have effects from poorly known operating environments. The turbulent and unpredictable conditions in which wind turbines operate create many challenges for their operation. In this paper, we design an adaptive collective pitch controller for a high-fidelity simulation of a utility scale, variable-speed horizontal axis wind turbine. The objective of the adaptive pitch controller in Region 3 is to regulate generator speed and reject step disturbances. The control objective is accomplished by collectively pitching the turbine blades. We use an extension of the Direct Model Reference Adaptive Control (DMRAC) approach to track a reference point and to reject persistent disturbances. The turbine simulation models the Controls Advanced Research Turbine (CART) of the National Renewable Energy Laboratory in Golden, Colorado. The CART is a utility-scale wind turbine which has a well-developed and extensively verified simulator. The adaptive collective pitch controller for Region 3 was compared in simulations with a bas celliansesical Proportional Integrator (PI) collective pitch controller. In the simulations, the adaptive pitch controller showed improved speed regulation in Region 3 when compared with the baseline PI pitch controller and it demonstrated robustness to modeling errors.

Design and operation of a Loran-C time reference station

NASA Technical Reports Server (NTRS)

Putkovich, K.

1974-01-01

Some of the practical questions that arise when one decides to use Loran-C in a time reference system are explored. An extensive effort is made to provide basic, practical information on establishing and operating a reference station. Four areas were covered: (1) the design, configuration and operational concepts which should be considered prior to establishing and operating a reference station using Loran-C, (2) the options and tradeoffs available regarding capabilities, cost, size, versatility, ease of operation, etc., that are available to the designer, (3) what measurements are made, how they are made and what they mean, and (4) the experience the U.S. Naval Observatory Time Service Division has had in the design and operation of such stations.

Study of a LH2-fueled topping cycle engine for aircraft propulsion

NASA Technical Reports Server (NTRS)

Turney, G. E.; Fishbach, L. H.

1983-01-01

An analytical investigation was made of a topping cycle aircraft engine system which uses a cryogenic fuel. This system consists of a main turboshaft engine which is mechanically coupled (by cross-shafting) to a topping loop which augments the shaft power output of the system. The thermodynamic performance of the topping cycle engine was analyzed and compared with that of a reference (conventional-type) turboshaft engine. For the cycle operating conditions selected, the performance of the topping cycle engine in terms of brake specific fuel consumption (bsfc) was determined to be about 12 percent better than that of the reference turboshaft engine. Engine weights were estimated for both the topping cycle engine and the reference turboshaft engine. These estimates were based on a common shaft power output for each engine. Results indicate that the weight of the topping cycle engine is comparable to that of the reference turboshaft engine. Previously announced in STAR as N83-34942

Comparison of two confocal micro-XRF spectrometers with different design aspects

PubMed Central

Smolek, S; Nakazawa, T; Tabe, A; Nakano, K; Tsuji, K; Streli, C; Wobrauschek, P

2014-01-01

Two different confocal micro X-ray fluorescence spectrometers have been developed and installed at Osaka City University and the Vienna University of Technology Atominstitut. The Osaka City University system is a high resolution spectrometer operating in air. The Vienna University of Technology Atominstitut spectrometer has a lower spatial resolution but is optimized for light element detection and operates under vacuum condition. The performance of both spectrometers was compared. In order to characterize the spatial resolution, a set of nine specially prepared single element thin film reference samples (500 nm in thickness, Al, Ti, Cr, Fe Ni, Cu, Zr, Mo, and Au) was used. Lower limits of detection were determined using the National Institute of Standards and Technology standard reference material glass standard 1412. A paint layer sample (cultural heritage application) and paint on automotive steel samples were analyzed with both instruments. The depth profile information was acquired by scanning the sample perpendicular to the surface. © 2013 The Authors. X-Ray Spectrometry published by John Wiley & Sons, Ltd. PMID:26430286

Comparison of two confocal micro-XRF spectrometers with different design aspects.

PubMed

Smolek, S; Nakazawa, T; Tabe, A; Nakano, K; Tsuji, K; Streli, C; Wobrauschek, P

2014-03-01

Two different confocal micro X-ray fluorescence spectrometers have been developed and installed at Osaka City University and the Vienna University of Technology Atominstitut. The Osaka City University system is a high resolution spectrometer operating in air. The Vienna University of Technology Atominstitut spectrometer has a lower spatial resolution but is optimized for light element detection and operates under vacuum condition. The performance of both spectrometers was compared. In order to characterize the spatial resolution, a set of nine specially prepared single element thin film reference samples (500 nm in thickness, Al, Ti, Cr, Fe Ni, Cu, Zr, Mo, and Au) was used. Lower limits of detection were determined using the National Institute of Standards and Technology standard reference material glass standard 1412. A paint layer sample (cultural heritage application) and paint on automotive steel samples were analyzed with both instruments. The depth profile information was acquired by scanning the sample perpendicular to the surface. © 2013 The Authors. X-Ray Spectrometry published by John Wiley & Sons, Ltd.

Comparison of cooperative and non-cooperative adaptive optics reference performance for propagation with thermal blooming effects

NASA Astrophysics Data System (ADS)

Edwards, Brian E.; Nitkowski, Arthur; Lawrence, Ryan; Horton, Kasey; Higgs, Charles

2004-10-01

Atmospheric turbulence and laser-induced thermal blooming effects can degrade the beam quality of a high-energy laser (HEL) weapon, and ultimately limit the amount of energy deliverable to a target. Lincoln Laboratory has built a thermal blooming laboratory capable of emulating atmospheric thermal blooming and turbulence effects for tactical HEL systems. The HEL weapon emulation hardware includes an adaptive optics beam delivery system, which utilizes a Shack-Hartman wavefront sensor and a 349 actuator deformable mirror. For this experiment, the laboratory was configured to emulate an engagement scenario consisting of sea skimming target approaching directly toward the HEL weapon at a range of 10km. The weapon utilizes a 1.5m aperture and radiates at a 1.62 micron wavelength. An adaptive optics reference beam was provided as either a point source located at the target (cooperative) or a projected point source reflected from the target (uncooperative). Performance of the adaptive optics system was then compared between reference sources. Results show that, for operating conditions with a thermal blooming distortion number of 75 and weak turbulence (Rytov of 0.02 and D/ro of 3), cooperative beacon AO correction experiences Phase Compensation Instability, resulting in lower performance than a simple, open-loop condition. The uncooperative beacon resulted in slightly better performance than the open-loop condition.

Effect of inlet temperature on the performance of a catalytic reactor. [air pollution control

NASA Technical Reports Server (NTRS)

Anderson, D. N.

1978-01-01

A 12 cm diameter by 15 cm long catalytic reactor was tested with No. 2 diesel fuel in a combustion test rig at inlet temperatures of 700, 800, 900, and 1000 K. Other test conditions included pressures of 3 and 6 x 10 to the 5th power Pa, reference velocities of 10, 15, and 20 m/s, and adiabatic combustion temperatures in the range 1100 to 1400 K. The combustion efficiency was calculated from measurements of carbon monoxide and unburned hydrocarbon emissions. Nitrogen oxide emissions and reactor pressure drop were also measured. At a reference velocity of 10 m/s, the CO and unburned hydrocarbons emissions, and, therefore, the combustion efficiency, were independent of inlet temperature. At an inlet temperature of 1000 K, they were independent of reference velocity. Nitrogen oxides emissions resulted from conversion of the small amount (135 ppm) of fuel-bound nitrogen in the fuel. Up to 90 percent conversion was observed with no apparent effect of any of the test variables. For typical gas turbine operating conditions, all three pollutants were below levels which would permit the most stringent proposed automotive emissions standards to be met.

The work of the European Union Reference Laboratory for Food Additives (EURL) and its support for the authorisation process of feed additives in the European Union: a review

PubMed Central

von Holst, Christoph; Robouch, Piotr; Bellorini, Stefano; de la Huebra, María José González; Ezerskis, Zigmas

2016-01-01

ABSTRACT This paper describes the operation of the European Union Reference Laboratory for Feed Additives (EURL) and its role in the authorisation procedure of feed additives in the European Union. Feed additives are authorised according to Regulation (EC) No. 1831/2003, which introduced a completely revised authorisation procedure and also established the EURL. The regulations authorising feed additives contain conditions of use such as legal limits of the feed additives, which require the availability of a suitable method of analysis for official control purposes under real world conditions. It is the task of the EURL to evaluate the suitability of analytical methods as proposed by the industry for this purpose. Moreover, the paper shows that one of the major challenges is the huge variety of the methodology applied in feed additive analysis, thus requiring expertise in quite different analytical areas. In order to cope with this challenge, the EURL is supported by a network of national reference laboratories (NRLs) and only the merged knowledge of all NRLs allows for a scientifically sound assessment of the analytical methods. PMID:26540604

Visual enhancements in pick-and-place tasks: Human operators controlling a simulated cylindrical manipulator

NASA Technical Reports Server (NTRS)

Kim, Won S.; Tendick, Frank; Stark, Lawrence

1989-01-01

A teleoperation simulator was constructed with vector display system, joysticks, and a simulated cylindrical manipulator, in order to quantitatively evaluate various display conditions. The first of two experiments conducted investigated the effects of perspective parameter variations on human operators' pick-and-place performance, using a monoscopic perspective display. The second experiment involved visual enhancements of the monoscopic perspective display, by adding a grid and reference lines, by comparison with visual enhancements of a stereoscopic display; results indicate that stereoscopy generally permits superior pick-and-place performance, but that monoscopy nevertheless allows equivalent performance when defined with appropriate perspective parameter values and adequate visual enhancements.

Assessing reference evapotranspiration in a subhumid climate in NE Austria

NASA Astrophysics Data System (ADS)

Nolz, Reinhard; Eitzinger, Josef; Cepuder, Peter

2015-04-01

Computing reference evapotranspiration and multiplying it with a specific crop coefficient as recommended by the Food and Agriculture Organization of the United Nations (FAO) is the most widely accepted approach to estimate plant water requirements. The standardized form of the well-known FAO Penman-Monteith equation, published by the Environmental and Water Resources Institute of the American Society of Civil Engineers (ASCE-EWRI), is recommended as a standard procedure for calculating reference evapotranspiration. Applied and validated under different climatic conditions it generally achieved good results compared to other methods. However, several studies documented deviations between measured and calculated reference evapotranspiration depending on local environmental conditions. Consequently, it seems advisable to evaluate the model under local environmental conditions. Evapotranspiration was determined at a subhumid site in Austria (48°12'N, 16°34'E; 157 m asl) using a large weighing lysimeter operated at (limited) reference conditions and compared with calculations according to ASCE-EWRI. The lysimeter had an inner diameter of 1.9 m and a hemispherical bottom with a maximum depth of 2.5 m. Seepage water was measured at a free draining outlet using a tipping bucket. Lysimeter mass changes were sensed by a weighing facility with an accuracy of ±0.1 mm. Both rainfall and evapotranspiration were determined directly from lysimeter data using a simple water balance equation. Meteorological data for the ASCE-EWRI model were obtained from a weather station of the Central Institute for Meteorology and Geodynamics, Austria (ZAMG). The study period was from 2005 to 2010, analyses were based upon daily time steps. Daily calculated reference evapotranspiration was generally overestimated at small values, whereas it was rather underestimated when evapotranspiration was large, which is supported also by other studies. In the given case, advection of sensible heat proved to have an impact. On the other hand, it could not explain the differences exclusively, as it was also shown that small net radiation in combination with small wind velocity produced by trend better results than small net radiation with a large wind velocity, which is somehow contradicting the principle of advection. Obviously, there were also other disregarded influences, for example seasonal varying surface resistance, albedo and soil heat flux. Generally, the ASCE-EWRI equation for daily time steps performed best at average weather conditions. The outcomes should help to correctly interpret reference evapotranspiration data in the region and in similar environments and improve knowledge on the dynamics of the influencing factors that caused the deviations.

Enhanced Flight Vision Systems Operational Feasibility Study Using Radar and Infrared Sensors

NASA Technical Reports Server (NTRS)

Etherington, Timothy J.; Kramer, Lynda J.; Severance, Kurt; Bailey, Randall E.; Williams, Steven P.; Harrison, Stephanie J.

2015-01-01

Approach and landing operations during periods of reduced visibility have plagued aircraft pilots since the beginning of aviation. Although techniques are currently available to mitigate some of the visibility conditions, these operations are still ultimately limited by the pilot's ability to "see" required visual landing references (e.g., markings and/or lights of threshold and touchdown zone) and require significant and costly ground infrastructure. Certified Enhanced Flight Vision Systems (EFVS) have shown promise to lift the obscuration veil. They allow the pilot to operate with enhanced vision, in lieu of natural vision, in the visual segment to enable equivalent visual operations (EVO). An aviation standards document was developed with industry and government consensus for using an EFVS for approach, landing, and rollout to a safe taxi speed in visibilities as low as 300 feet runway visual range (RVR). These new standards establish performance, integrity, availability, and safety requirements to operate in this regime without reliance on a pilot's or flight crew's natural vision by use of a fail-operational EFVS. A pilot-in-the-loop high-fidelity motion simulation study was conducted at NASA Langley Research Center to evaluate the operational feasibility, pilot workload, and pilot acceptability of conducting straight-in instrument approaches with published vertical guidance to landing, touchdown, and rollout to a safe taxi speed in visibility as low as 300 feet RVR by use of vision system technologies on a head-up display (HUD) without need or reliance on natural vision. Twelve crews flew various landing and departure scenarios in 1800, 1000, 700, and 300 RVR. This paper details the non-normal results of the study including objective and subjective measures of performance and acceptability. The study validated the operational feasibility of approach and departure operations and success was independent of visibility conditions. Failures were handled within the lateral confines of the runway for all conditions tested. The fail-operational concept with pilot in the loop needs further study.

Some effects of adverse weather conditions on performance of airplane antiskid braking systems

NASA Technical Reports Server (NTRS)

Horne, W. B.; Mccarty, J. L.; Tanner, J. A.

1976-01-01

The performance of current antiskid braking systems operating under adverse weather conditions was analyzed in an effort to both identify the causes of locked-wheel skids which sometimes occur when the runway is slippery and to find possible solutions to this operational problem. This analysis was made possible by the quantitative test data provided by recently completed landing research programs using fully instrumented flight test airplanes and was further supported by tests performed at the Langley aircraft landing loads and traction facility. The antiskid system logic for brake control and for both touchdown and locked-wheel protection is described and its response behavior in adverse weather is discussed in detail with the aid of available data. The analysis indicates that the operational performance of the antiskid logic circuits is highly dependent upon wheel spin-up acceleration and can be adversely affected by certain pilot braking inputs when accelerations are low. Normal antiskid performance is assured if the tire-to-runway traction is sufficient to provide high wheel spin-up accelerations or if the system is provided a continuous, accurate ground speed reference. The design of antiskid systems is complicated by the necessity for tradeoffs between tire braking and cornering capabilities, both of which are necessary to provide safe operations in the presence of cross winds, particularly under slippery runway conditions.

Some in-field experiences of non-synchronous vibrations in large rotating machinery

NASA Technical Reports Server (NTRS)

Colnago, Giuseppe; Frigeri, Claudio; Vallini, Andrea; Zanetta, Gian Antonio

1989-01-01

Some problems associated with non-synchronous vibrations are analyzed by describing three cases experienced with fairly large rotating machines in operating conditions. In each case, a brief description is first given of the machine and of the instrumentation used. The experimental results are then presented, with reference to time or frequency domain recordings. The lines followed in diagnosis are then discussed and, lastly, the corrective action undertaken is presented.

Soil-Landscape Relations at Selected Sites Along Environmental Gradients in Northern Alaska.

DTIC Science & Technology

1981-05-01

conditions of a frigid humid climate, poor drainage, gleization and mechanical disturbance and thus were placed within the Zonal Soil Order. The...operating: (1) gleization , (2) congeliturbation, and (3) organic accretion. Manganese and iron occur in soil systems in both oxidized and/or reduced...yellowish-red mottles and in grey matrix, is referred to as gleying ( gleization ). In some gleyed soils the process is favored by a fluctuating water table

Design and methods of the Southeast Stream Quality Assessment (SESQA), 2014

USGS Publications Warehouse

Journey, Celeste A.; Van Metre, Peter C.; Bell, Amanda H.; Button, Daniel T.; Garrett, Jessica D.; Nakagaki, Naomi; Qi, Sharon L.; Bradley, Paul M.

2015-07-15

This report provides a detailed description of the SESQA study components, including surveys of ecological conditions, routine water sampling, deployment of passive polar organic compound integrative samplers for pesticides and contaminants of emerging concern, and synoptic sediment sampling and toxicity testing at all urban, confined animal feeding operation, and reference sites. Continuous water-quality monitoring and daily pesticide sampling efforts conducted at a subset of urban sites are also described.

[Risk management of soybean-related asthma: monitoring and surveillance].

PubMed

Villalbí, Joan R; Carrascal, Dolors; Caylà, Joan A; Rodríguez, Pau; Cruz, M A Jesús; Pintó, Josep M

2011-01-01

Allergen emissions during soybean unloading operations in the Barcelona harbor have caused asthma epidemics. The present article aimed to describe the surveillance and control measures carried out by the public health services. Data were extracted from control systems from 1999 to 2009, with description of the surveillance schemes for allergen emissions, environmental concentrations (with defined reference levels) and for health. Of 95 studies of plant emission, four were above the reference levels, and filters were found to be the most likely cause. Mean environmental concentrations were low but were above the reference levels on 13 days; these levels were related to adverse meteorological conditions and incidents in the plants. No health effects were detected in the panel of patients nor epidemic asthma days. The system detects incidents and has shown its usefulness in protecting public health. Copyright © 2011 SESPAS. Published by Elsevier Espana. All rights reserved.

Flight Deck-Based Delegated Separation: Evaluation of an On-Board Interval Management System with Synthetic and Enhanced Vision Technology

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III; Shelton, Kevin J.; Kramer, Lynda J.; Arthur, Jarvis J.; Bailey, Randall E.; Norman, Rober M.; Ellis, Kyle K. E.; Barmore, Bryan E.

2011-01-01

An emerging Next Generation Air Transportation System concept - Equivalent Visual Operations (EVO) - can be achieved using an electronic means to provide sufficient visibility of the external world and other required flight references on flight deck displays that enable the safety, operational tempos, and visual flight rules (VFR)-like procedures for all weather conditions. Synthetic and enhanced flight vision system technologies are critical enabling technologies to EVO. Current research evaluated concepts for flight deck-based interval management (FIM) operations, integrated with Synthetic Vision and Enhanced Vision flight-deck displays and technologies. One concept involves delegated flight deck-based separation, in which the flight crews were paired with another aircraft and responsible for spacing and maintaining separation from the paired aircraft, termed, "equivalent visual separation." The operation required the flight crews to acquire and maintain an "equivalent visual contact" as well as to conduct manual landings in low-visibility conditions. The paper describes results that evaluated the concept of EVO delegated separation, including an off-nominal scenario in which the lead aircraft was not able to conform to the assigned spacing resulting in a loss of separation.

Generator voltage stabilisation for series-hybrid electric vehicles.

PubMed

Stewart, P; Gladwin, D; Stewart, J; Cowley, R

2008-04-01

This paper presents a controller for use in speed control of an internal combustion engine for series-hybrid electric vehicle applications. Particular reference is made to the stability of the rectified DC link voltage under load disturbance. In the system under consideration, the primary power source is a four-cylinder normally aspirated gasoline internal combustion engine, which is mechanically coupled to a three-phase permanent magnet AC generator. The generated AC voltage is subsequently rectified to supply a lead-acid battery, and permanent magnet traction motors via three-phase full bridge power electronic inverters. Two complementary performance objectives exist. Firstly to maintain the internal combustion engine at its optimal operating point, and secondly to supply a stable 42 V supply to the traction drive inverters. Achievement of these goals minimises the transient energy storage requirements at the DC link, with a consequent reduction in both weight and cost. These objectives imply constant velocity operation of the internal combustion engine under external load disturbances and changes in both operating conditions and vehicle speed set-points. An electronically operated throttle allows closed loop engine velocity control. System time delays and nonlinearities render closed loop control design extremely problematic. A model-based controller is designed and shown to be effective in controlling the DC link voltage, resulting in the well-conditioned operation of the hybrid vehicle.

Overview of condition monitoring and operation control of electric power conversion systems in direct-drive wind turbines under faults

NASA Astrophysics Data System (ADS)

Huang, Shoudao; Wu, Xuan; Liu, Xiao; Gao, Jian; He, Yunze

2017-09-01

Electric power conversion system (EPCS), which consists of a generator and power converter, is one of the most important subsystems in a direct-drive wind turbine (DD-WT). However, this component accounts for the most failures (approximately 60% of the total number) in the entire DD-WT system according to statistical data. To improve the reliability of EPCSs and reduce the operation and maintenance cost of DD-WTs, numerous researchers have studied condition monitoring (CM) and fault diagnostics (FD). Numerous CM and FD techniques, which have respective advantages and disadvantages, have emerged. This paper provides an overview of the CM, FD, and operation control of EPCSs in DD-WTs under faults. After introducing the functional principle and structure of EPCS, this survey discusses the common failures in wind generators and power converters; briefly reviewed CM and FD methods and operation control of these generators and power converters under faults; and discussed the grid voltage faults related to EPCSs in DD-WTs. These theories and their related technical concepts are systematically discussed. Finally, predicted development trends are presented. The paper provides a valuable reference for developing service quality evaluation methods and fault operation control systems to achieve high-performance and high-intelligence DD-WTs.

Normative Data for the NeuroCom Sensory Organization Test in US Military Special Operations Forces

PubMed Central

Pletcher, Erin R.; Williams, Valerie J.; Abt, John P.; Morgan, Paul M.; Parr, Jeffrey J.; Wohleber, Meleesa F.; Lovalekar, Mita; Sell, Timothy C.

2017-01-01

Context: Postural stability is the ability to control the center of mass in relation to a person's base of support and can be affected by both musculoskeletal injury and traumatic brain injury. The NeuroCom Sensory Organization Test (SOT) can be used to objectively quantify impairments to postural stability. The ability of postural stability to predict injury and be used as an acute injury-evaluation tool makes it essential to the screening and rehabilitation process. To our knowledge, no published normative data for the SOT from a healthy, highly active population are available for use as a reference for clinical decision making. Objective: To present a normative database of SOT scores from a US Military Special Operations population that can be used for future comparison. Design: Cross-sectional study. Setting: Human performance research laboratory. Patients or Other Participants: A total of 542 active military operators from Naval Special Warfare Combatant-Craft Crewmen (n = 149), Naval Special Warfare Command, Sea, Air, and Land (n = 101), US Army Special Operations Command (n = 171), and Air Force Special Operations Command (n = 121). Main Outcome Measure(s): Participants performed each of the 6 SOT conditions 3 times. Scores for each condition, total equilibrium composite score, and ratio scores for the somatosensory, visual, and vestibular systems were recorded. Results: Differences were present across all groups for SOT conditions 1 (P < .001), 2 (P = .001), 4 (P > .001), 5 (P > .001), and 6 (P = .001) and total equilibrium composite (P = .000), visual (P > .001), vestibular (P = .002), and preference (P > .001) NeuroCom scores. Conclusions: Statistical differences were evident in the distribution of postural stability across US Special Operations Forces personnel. This normative database for postural stability, as assessed by the NeuroCom SOT, can provide context when clinicians assess a Special Operations Forces population or any other groups that maintain a high level of conditioning and training. PMID:28140624

Normative Data for the NeuroCom Sensory Organization Test in US Military Special Operations Forces.

PubMed

Pletcher, Erin R; Williams, Valerie J; Abt, John P; Morgan, Paul M; Parr, Jeffrey J; Wohleber, Meleesa F; Lovalekar, Mita; Sell, Timothy C

2017-02-01

Postural stability is the ability to control the center of mass in relation to a person's base of support and can be affected by both musculoskeletal injury and traumatic brain injury. The NeuroCom Sensory Organization Test (SOT) can be used to objectively quantify impairments to postural stability. The ability of postural stability to predict injury and be used as an acute injury-evaluation tool makes it essential to the screening and rehabilitation process. To our knowledge, no published normative data for the SOT from a healthy, highly active population are available for use as a reference for clinical decision making. To present a normative database of SOT scores from a US Military Special Operations population that can be used for future comparison. Cross-sectional study. Human performance research laboratory. A total of 542 active military operators from Naval Special Warfare Combatant-Craft Crewmen (n = 149), Naval Special Warfare Command, Sea, Air, and Land (n = 101), US Army Special Operations Command (n = 171), and Air Force Special Operations Command (n = 121). Participants performed each of the 6 SOT conditions 3 times. Scores for each condition, total equilibrium composite score, and ratio scores for the somatosensory, visual, and vestibular systems were recorded. Differences were present across all groups for SOT conditions 1 (P < .001), 2 (P = .001), 4 (P > .001), 5 (P > .001), and 6 (P = .001) and total equilibrium composite (P = .000), visual (P > .001), vestibular (P = .002), and preference (P > .001) NeuroCom scores. Statistical differences were evident in the distribution of postural stability across US Special Operations Forces personnel. This normative database for postural stability, as assessed by the NeuroCom SOT, can provide context when clinicians assess a Special Operations Forces population or any other groups that maintain a high level of conditioning and training.

Crew and Display Concepts Evaluation for Synthetic / Enhanced Vision Systems

NASA Technical Reports Server (NTRS)

Bailey, Randall E.; Kramer, Lynda J.; Prinzel, Lawrence J., III

2006-01-01

NASA s Synthetic Vision Systems (SVS) project is developing technologies with practical applications that strive to eliminate low-visibility conditions as a causal factor to civil aircraft accidents and replicate the operational benefits of clear day flight operations, regardless of the actual outside visibility condition. Enhanced Vision System (EVS) technologies are analogous and complementary in many respects to SVS, with the principle difference being that EVS is an imaging sensor presentation, as opposed to a database-derived image. The use of EVS in civil aircraft is projected to increase rapidly as the Federal Aviation Administration recently changed the aircraft operating rules under Part 91, revising the flight visibility requirements for conducting operations to civil airports. Operators conducting straight-in instrument approach procedures may now operate below the published approach minimums when using an approved EVS that shows the required visual references on the pilot s Head-Up Display. An experiment was conducted to evaluate the complementary use of SVS and EVS technologies, specifically focusing on new techniques for integration and/or fusion of synthetic and enhanced vision technologies and crew resource management while operating under the newly adopted FAA rules which provide operating credit for EVS. Overall, the experimental data showed that significant improvements in SA without concomitant increases in workload and display clutter could be provided by the integration and/or fusion of synthetic and enhanced vision technologies for the pilot-flying and the pilot-not-flying.

The Then and Now of Reference Conditions in Streams of the Central Plains

NASA Astrophysics Data System (ADS)

Huggins, D.; Angelo, R.; Baker, D. S.; Welker, G.

2005-05-01

Models of contemporary and pre-settlement reference conditions were constructed for streams that once drained the tallgrass prairies of Iowa, Nebraska, Kansas and Missouri (e.g. Western Corn Belt Plains ecoregion), and for streams within the heart of the mixed grass prairie (e.g. Southwestern Tablelands ecoregion). Data on watershed, habitat, chemistry and biology compiled for existing reference streams (least or minimally impacted systems) were used to characterize contemporary reference conditions. Contemporary reference conditions within these two prairie regions are contrasted against hypothetical pre-settlement conditions using information from the best streams (upper 25%) of the current reference population, historical accounts, museum records, natural heritage programs, Public Land Survey and current remote sensing data. Similar comparisons were made between historical and current reference conditions for the Southwestern Tablelands located in central Kansas and Oklahoma. Much of this region remains in mixed grass prairie; has limited hydrological alterations (e.g. impoundments, dewatering) and low human and livestock densities. Within the tablelands these factors have preserved reference conditions that resemble historic conditions. Qualitative and quantitative comparisons indicate that many regions within the Central Plains require caution when using "least disturbed" reference streams and conditions to identify regional biological integrity goals relative to the Clean Water Act.

Assessing operating characteristics of CAD algorithms in the absence of a gold standard

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

Roy Choudhury, Kingshuk; Paik, David S.; Yi, Chin A.

2010-04-15

Purpose: The authors examine potential bias when using a reference reader panel as ''gold standard'' for estimating operating characteristics of CAD algorithms for detecting lesions. As an alternative, the authors propose latent class analysis (LCA), which does not require an external gold standard to evaluate diagnostic accuracy. Methods: A binomial model for multiple reader detections using different diagnostic protocols was constructed, assuming conditional independence of readings given true lesion status. Operating characteristics of all protocols were estimated by maximum likelihood LCA. Reader panel and LCA based estimates were compared using data simulated from the binomial model for a range ofmore » operating characteristics. LCA was applied to 36 thin section thoracic computed tomography data sets from the Lung Image Database Consortium (LIDC): Free search markings of four radiologists were compared to markings from four different CAD assisted radiologists. For real data, bootstrap-based resampling methods, which accommodate dependence in reader detections, are proposed to test of hypotheses of differences between detection protocols. Results: In simulation studies, reader panel based sensitivity estimates had an average relative bias (ARB) of -23% to -27%, significantly higher (p-value <0.0001) than LCA (ARB -2% to -6%). Specificity was well estimated by both reader panel (ARB -0.6% to -0.5%) and LCA (ARB 1.4%-0.5%). Among 1145 lesion candidates LIDC considered, LCA estimated sensitivity of reference readers (55%) was significantly lower (p-value 0.006) than CAD assisted readers' (68%). Average false positives per patient for reference readers (0.95) was not significantly lower (p-value 0.28) than CAD assisted readers' (1.27). Conclusions: Whereas a gold standard based on a consensus of readers may substantially bias sensitivity estimates, LCA may be a significantly more accurate and consistent means for evaluating diagnostic accuracy.« less

Land-use history and contemporary management inform an ecological reference model for longleaf pine woodland understory plant communities

Treesearch

Lars A. Brudvig; John L. Orrock; Ellen I. Damschen; Cathy D. Collins; Philip G. Hahn; W. Brett Mattingly; Joseph W. Veldman; Joan L. Walker

2014-01-01

Ecological restoration is frequently guided by reference conditions describing a successfully restored ecosystem; however, the causes and magnitude of ecosystem degradation vary, making simple knowledge of reference conditions insufficient for prioritizing and guiding restoration. Ecological reference models provide further guidance by quantifying reference conditions...

CSER 01-008 Canning of Thermally Stabilized Plutonium Oxide Powder in PFP Glovebox HC-21A

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

ERICKSON, D.G.

This document presents the analysis performed to support the canning operation in HC-21A. Most of the actual analysis was performed for the operation in HC-18M and HA-20MB, and is documented in HNF-2707 Rev I a (Erickson 2001a). This document will reference Erickson (2001a) as necessary to support the operation in HC-21A. The plutonium stabilization program at the Plutonium Finishing Plant (PFP) uses heat to convert plutonium-bearing materials into dry powder that is chemically stable for long term storage. The stabilized plutonium is transferred into one of several gloveboxes for the canning process, Gloveboxes HC-18M in Room 228'2, HA-20MB in Roommore » 235B, and HC-21A in Room 230B are to be used for this process. This document presents the analysis performed to support the canning operation in HC-21A. Most of the actual analysis was performed for the operation in HC-I8M and HA-20MB, and is documented in HNF-2707 Rev l a (Erickson 2001a). This document will reference Erickson (2001a) as necessary to support the operation in HC-21A. Evaluation of this operation included normal, base cases, and contingencies. The base cases took the normal operations for each type of feed material and added the likely off-normal events. Each contingency is evaluated assuming the unlikely event happens to the conservative base case. Each contingency was shown to meet the double contingency requirement. That is, at least two unlikely, independent, and concurrent changes in process conditions are required before a criticality is possible.« less

Modelling and simulation of a pervaporation process using tubular module for production of anhydrous ethanol

NASA Astrophysics Data System (ADS)

Hieu, Nguyen Huu

2017-09-01

Pervaporation is a potential process for the final step of ethanol biofuel production. In this study, a mathematical model was developed based on the resistance-in-series model and a simulation was carried out using the specialized simulation software COMSOL Multiphysics to describe a tubular type pervaporation module with membranes for the dehydration of ethanol solution. The permeance of membranes, operating conditions, and feed conditions in the simulation were referred from experimental data reported previously in literature. Accordingly, the simulated temperature and density profiles of pure water and ethanol-water mixture were validated based on existing published data.

SSME structural computer program development. Volume 3: BOPACE demonstration analysis of the SSME thrust chamber liner

NASA Technical Reports Server (NTRS)

Spring, A. H.

1973-01-01

The application of a structural computer program for analysis of a thrust chamber liner is discussed. Two objectives were accomplished as follows: (1) exercise of the full capabilities of the computer program and (2) definition of thermal and mechanical boundary conditions to reflect the emergency power level operating conditions for the SSME 47OK engine at a station just upstream of the thrust chamber throat. Creep information on the thrust chamber is presented as a reference curve of creep strain versus time for various temperatures. Contour plots of the effective plastic strain, effective stress, and effective creep strain are developed.

Study of flue-gas temperature difference in supercritical once-through boiler

NASA Astrophysics Data System (ADS)

Kang, Yanchang; Li, Bing; Song, Ang

2018-02-01

The 600 MW coal-fired once-through Boilers with opposed firing at a power plant are found to experience marked temperature variation and even overtemperature on the wall of the heating surface as a result of flue-gas temperature (FGT) variation in the boiler. In this study, operational adjustments were made to the pulverizing, combustion, and secondary air box systems in these boilers, in order to solve problems in internal combustion. The adjustments were found to reduce FGT difference and optimize the boiler’ combustion conditions. The results of this study can provide a reference for optimization of coal-fired boiler of the same type in similar conditions.

Measurement accuracy of weighing and tipping-bucket rainfall intensity gauges under dynamic laboratory testing

NASA Astrophysics Data System (ADS)

Colli, M.; Lanza, L. G.; La Barbera, P.; Chan, P. W.

2014-07-01

The contribution of any single uncertainty factor in the resulting performance of infield rain gauge measurements still has to be comprehensively assessed due to the high number of real world error sources involved, such as the intrinsic variability of rainfall intensity (RI), wind effects, wetting losses, the ambient temperature, etc. In recent years the World Meteorological Organization (WMO) addressed these issues by fostering dedicated investigations, which revealed further difficulties in assessing the actual reference rainfall intensity in the field. This work reports on an extensive assessment of the OTT Pluvio2 weighing gauge accuracy when measuring rainfall intensity under laboratory dynamic conditions (time varying reference flow rates). The results obtained from the weighing rain gauge (WG) were also compared with a MTX tipping-bucket rain gauge (TBR) under the same test conditions. Tests were carried out by simulating various artificial precipitation events, with unsteady rainfall intensity, using a suitable dynamic rainfall generator. Real world rainfall data measured by an Ogawa catching-type drop counter at a field test site located within the Hong Kong International Airport (HKIA) were used as a reference for the artificial rain generation system. Results demonstrate that the differences observed between the laboratory and field performance of catching-type gauges are only partially attributable to the weather and operational conditions in the field. The dynamics of real world precipitation events is responsible for a large part of the measurement errors, which can be accurately assessed in the laboratory under controlled environmental conditions. This allows for new testing methodologies and the development of instruments with enhanced performance in the field.

Self-Test Procedures for Gas Sensors Embedded in Microreactor Systems

PubMed Central

Helwig, Andreas; Hackner, Angelika; Zappa, Dario; Sberveglieri, Giorgio

2018-01-01

Metal oxide (MOX) gas sensors sensitively respond to a wide variety of combustible, explosive and poisonous gases. However, due to the lack of a built-in self-test capability, MOX gas sensors have not yet been able to penetrate safety-critical applications. In the present work we report on gas sensing experiments performed on MOX gas sensors embedded in ceramic micro-reaction chambers. With the help of an external micro-pump, such systems can be operated in a periodic manner alternating between flow and no-flow conditions, thus allowing repetitive measurements of the sensor resistances under clean air, R0, and under gas exposure, Rgas, to be obtained, even under field conditions. With these pairs of resistance values, eventual drifts in the sensor baseline resistance can be detected and drift-corrected values of the relative resistance response Resp=(R0−Rgas)/R0 can be determined. Residual poisoning-induced changes in the relative resistance response can be detected by reference to humidity measurements taken with room-temperature-operated capacitive humidity sensors which are insensitive to the poisoning processes operative on heated MOX gas sensors. PMID:29401673

Transient thermal analysis for radioactive liquid mixing operations in a large-scaled tank

DOE PAGES

Lee, S. Y.; Smith, III, F. G.

2014-07-25

A transient heat balance model was developed to assess the impact of a Submersible Mixer Pump (SMP) on radioactive liquid temperature during the process of waste mixing and removal for the high-level radioactive materials stored in Savannah River Site (SRS) tanks. The model results will be mainly used to determine the SMP design impacts on the waste tank temperature during operations and to develop a specification for a new SMP design to replace existing longshaft mixer pumps used during waste removal. The present model was benchmarked against the test data obtained by the tank measurement to examine the quantitative thermalmore » response of the tank and to establish the reference conditions of the operating variables under no SMP operation. The results showed that the model predictions agreed with the test data of the waste temperatures within about 10%.« less

Neural network feedforward control of a closed-circuit wind tunnel

NASA Astrophysics Data System (ADS)

Sutcliffe, Peter

Accurate control of wind-tunnel test conditions can be dramatically enhanced using feedforward control architectures which allow operating conditions to be maintained at a desired setpoint through the use of mathematical models as the primary source of prediction. However, as the desired accuracy of the feedforward prediction increases, the model complexity also increases, so that an ever increasing computational load is incurred. This drawback can be avoided by employing a neural network that is trained offline using the output of a high fidelity wind-tunnel mathematical model, so that the neural network can rapidly reproduce the predictions of the model with a greatly reduced computational overhead. A novel neural network database generation method, developed through the use of fractional factorial arrays, was employed such that a neural network can accurately predict wind-tunnel parameters across a wide range of operating conditions whilst trained upon a highly efficient database. The subsequent network was incorporated into a Neural Network Model Predictive Control (NNMPC) framework to allow an optimised output schedule capable of providing accurate control of the wind-tunnel operating parameters. Facilitation of an optimised path through the solution space is achieved through the use of a chaos optimisation algorithm such that a more globally optimum solution is likely to be found with less computational expense than the gradient descent method. The parameters associated with the NNMPC such as the control horizon are determined through the use of a Taguchi methodology enabling the minimum number of experiments to be carried out to determine the optimal combination. The resultant NNMPC scheme was employed upon the Hessert Low Speed Wind Tunnel at the University of Notre Dame to control the test-section temperature such that it follows a pre-determined reference trajectory during changes in the test-section velocity. Experimental testing revealed that the derived NNMPC controller provided an excellent level of control over the test-section temperature in adherence to a reference trajectory even when faced with unforeseen disturbances such as rapid changes in the operating environment.

Optical dynamic range maximization for humidity sensing by controlling growth of zinc oxide nanorods

NASA Astrophysics Data System (ADS)

Yusof, Haziezol Helmi Mohd; Harun, Sulaiman Wadi; Dimyati, Kaharudin; Bora, Tanujjal; Mohammed, Waleed S.; Dutta, Joydeep

2018-07-01

An experimental study of the dynamic range maximization with Zinc Oxide (ZnO) nanorods coated glass substrates for humidity and vapor sensing is reported. Growth time of the nanorods and the length of the coated segments were controlled to study the differences between a reference environmental condition (normal humidity or dry condition) and water vapor concentrations. In order to achieve long dynamic range of detection with respect to nanorods coverage, several substrates with triangular patterns of ZnO nanostructures were fabricated by selective hydrothermal growth over different durations of time (5 h, 10 h and 15 h). It was found that maximum dynamic range for the humidity sensing occurs for the combination parameters of normalized length (Z) of 0.23 and normalized scattering coefficient (ζ) of 0.3. A reduction in transmittance by 38% at humidity levels of 80% with reference point as 50% humidity was observed. The results could be correlated to a first order approximation model that assumes uniform growth and the optimum operating conditions for humidity sensing device. This study provides an option to correlate ZnO growth conditions for different vapor sensing applications which can set a platform for compact sensors where modulation of light intensity is followed.

Studies Related to the Oregon State University High Temperature Test Facility: Scaling, the Validation Matrix, and Similarities to the Modular High Temperature Gas-Cooled Reactor

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

Richard R. Schultz; Paul D. Bayless; Richard W. Johnson

2010-09-01

The Oregon State University (OSU) High Temperature Test Facility (HTTF) is an integral experimental facility that will be constructed on the OSU campus in Corvallis, Oregon. The HTTF project was initiated, by the U.S. Nuclear Regulatory Commission (NRC), on September 5, 2008 as Task 4 of the 5 year High Temperature Gas Reactor Cooperative Agreement via NRC Contract 04-08-138. Until August, 2010, when a DOE contract was initiated to fund additional capabilities for the HTTF project, all of the funding support for the HTTF was provided by the NRC via their cooperative agreement. The U.S. Department of Energy (DOE) beganmore » their involvement with the HTTF project in late 2009 via the Next Generation Nuclear Plant project. Because the NRC interests in HTTF experiments were only centered on the depressurized conduction cooldown (DCC) scenario, NGNP involvement focused on expanding the experimental envelope of the HTTF to include steady-state operations and also the pressurized conduction cooldown (PCC). Since DOE has incorporated the HTTF as an ingredient in the NGNP thermal-fluids validation program, several important outcomes should be noted: 1. The reference prismatic reactor design, that serves as the basis for scaling the HTTF, became the modular high temperature gas-cooled reactor (MHTGR). The MHTGR has also been chosen as the reference design for all of the other NGNP thermal-fluid experiments. 2. The NGNP validation matrix is being planned using the same scaling strategy that has been implemented to design the HTTF, i.e., the hierarchical two-tiered scaling methodology developed by Zuber in 1991. Using this approach a preliminary validation matrix has been designed that integrates the HTTF experiments with the other experiments planned for the NGNP thermal-fluids verification and validation project. 3. Initial analyses showed that the inherent power capability of the OSU infrastructure, which only allowed a total operational facility power capability of 0.6 MW, is inadequate to permit steady-state operation at reasonable conditions. 4. To enable the HTTF to operate at a more representative steady-state conditions, DOE recently allocated funding via a DOE subcontract to HTTF to permit an OSU infrastructure upgrade such that 2.2 MW will become available for HTTF experiments. 5. Analyses have been performed to study the relationship between HTTF and MHTGR via the hierarchical two-tiered scaling methodology which has been used successfully in the past, e.g., APEX facility scaling to the Westinghouse AP600 plant. These analyses have focused on the relationship between key variables that will be measured in the HTTF to the counterpart variables in the MHTGR with a focus on natural circulation, using nitrogen as a working fluid, and core heat transfer. 6. Both RELAP5-3D and computational fluid dynamics (CD-Adapco’s STAR-CCM+) numerical models of the MHTGR and the HTTF have been constructed and analyses are underway to study the relationship between the reference reactor and the HTTF. The HTTF is presently being designed. It has ¼-scaling relationship to the MHTGR in both the height and the diameter. Decisions have been made to design the reactor cavity cooling system (RCCS) simulation as a boundary condition for the HTTF to ensure that (a) the boundary condition is well defined and (b) the boundary condition can be modified easily to achieve the desired heat transfer sink for HTTF experimental operations.« less

Optical Data Processing for Missile Guidance.

DTIC Science & Technology

1984-11-21

and architectures for back -substitution and the solution of triangular systems of LAEs (linear algebraic equations). Most recently, a parallel QR...Calculation of I1 is quite difficult since the o T exact Z matrix is quite ill-conditioned. The two VC choices considered in our system are E - I and E I - 0...shown in fig. 1. It These operations are most commonly referred to as shows the ship in water with a sky and shoreline back - segmentation and also

Unusual presentation of gastric perforation in a neonate: subcutaneous emphysema and scrotal pneumatocele.

PubMed

Erdogan, Derya

2013-04-01

Gastric perforation in neonates is an uncommon condition. A four-day-male neonate was referred with respiratory distress, abdominal distention, right scrotal swelling and extensive emphysema of the abdominal wall. Abdominal X-ray findings showed bilateral sub-diaphragmatic free air, right scrotal pneumatocele and subcutaneous emphysema of the abdominal wall. During the operation, pre-pyloric perforation was determined. Primary repair by single layer suture was performed and postoperative period was uneventful.

Process concept of retorting of Julia Creek oil shale

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

Sitnai, O.

1984-06-01

A process is proposed for the above ground retorting of the Julia Creek oil shale in Queensland. The oil shale characteristics, process description, chemical reactions of the oil shale components, and the effects of variable and operating conditions on process performance are discussed. The process contains a fluidized bed combustor which performs both as a combustor of the spent shales and as a heat carrier generator for the pyrolysis step. 12 references, 5 figures, 5 tables.

Site Location Details, Air Pollution Monitoring Equipment Used, Aircraft Flight Path Information, and Deployment Configuration for the DISCOVER-AQ (Deriving Information on Surface Conditions from COlumn and VERtically Resolved Observations Relevant to Air Quality) Field Campaign in Colorado: Summer 2014

EPA Science Inventory

For EPA, this Summer 2014, Denver CO, DISCOVER-AQ field research activity focused on assessing Federal Reference Methods (FRMs) and Federal Equivalent Methods (FEMs) for ozone (O3) and Nitrogen Dioxide (NO2), while comparing their operational performance to each other and to smal...

Operational Level Air Commanders: A Search for the Elements of Genius

DTIC Science & Technology

1994-06-01

courage in the face of moral danger. This is also referred to as courage d’espirit. Richard Simpkin, author of Race to the Swift, identifies this as the...enemy’s political, military, economic or social infrastructure.83 Group Captain Andrew Vallance of the Royal Air Force asserts that �airpower has...Finally, Vallance suggests that airpower has some conditional characteristics. The first such characteristic is that of depending on bases. If your

Hyperparathyroidism: retrospect and prospect.

PubMed Central

Taylor, S.

1976-01-01

The history of hyperparathyroidism is outlined and the diagnosis and treatment of its various causes reviewed with reference to a series of 153 patients operated on for hyperparathyroidism in the past 20 years. In 119 cases the condition was primary, being due to a tumour or hyperplasia. Future developments in this field are briefly considered. Images Fig. 1 Fig. 3 Fig. 4 Fig. 2 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 PMID:782326

A Preliminary Study of Ice-Accretion Scaling for SLD Conditions

NASA Technical Reports Server (NTRS)

Anderson, David N.

2003-01-01

Proposed changes to aircraft icing certification rules are being considered by European, Canadian, and American regulatory agencies to include operation in super-cooled large droplet conditions (SLD). This paper reports results of an experimental study in the NASA Glenn Icing Research Tunnel (IRT) to evaluate how well scaling methods developed for Appendix C conditions might apply to SLD conditions. Until now, scaling studies have been confined to the FAA FAR-25 Appendix C envelope of atmospheric cloud conditions. Tests were made in which it was attempted to scale to a droplet MVD of 50 microns from clouds having droplet MVDs of 175, 120, 100, and 70 microns. Scaling was based on the Ruff method with scale velocities found either by maintaining constant Weber number or by using the average of the velocities obtained by maintaining constant Weber number and constant Reynolds number. Models were unswept NACA 0012 wing sections. The reference model had a chord of 91.4 cm. Scale models had chords of 91.4, 80.0, and 53.3 cm. Tests were conducted with reference airspeeds of 100 and 150 kt (52 and 77 m/s) and with freezing fractions of 1.0, 0.6, and 0.3. It was demonstrated that the scaled 50-micron cloud simulated well the non-dimensional ice shapes accreted in clouds with MVD's of 120 microns or less.

Rate Theory Modeling and Simulation of Silicide Fuel at LWR Conditions

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

Miao, Yinbin; Ye, Bei; Hofman, Gerard

As a promising candidate for the accident tolerant fuel (ATF) used in light water reactors (LWRs), the fuel performance of uranium silicide (U 3Si 2) at LWR conditions needs to be well understood. In this report, rate theory model was developed based on existing experimental data and density functional theory (DFT) calculations so as to predict the fission gas behavior in U 3Si 2 at LWR conditions. The fission gas behavior of U 3Si 2 can be divided into three temperature regimes. During steady-state operation, the majority of the fission gas stays in intragranular bubbles, whereas the dominance of intergranularmore » bubbles and fission gas release only occurs beyond 1000 K. The steady-state rate theory model was also used as reference to establish a gaseous swelling correlation of U 3Si 2 for the BISON code. Meanwhile, the overpressurized bubble model was also developed so that the fission gas behavior at LOCA can be simulated. LOCA simulation showed that intragranular bubbles are still dominant after a 70 second LOCA, resulting in a controllable gaseous swelling. The fission gas behavior of U 3Si 2 at LWR conditions is benign according to the rate theory prediction at both steady-state and LOCA conditions, which provides important references to the qualification of U 3Si 2 as a LWR fuel material with excellent fuel performance and enhanced accident tolerance.« less

Effect of fuel zoning and fuel nozzle design on pollution emissions at ground idle conditions for a double-annular ram-induction combustor

NASA Technical Reports Server (NTRS)

Clements, T. R.

1973-01-01

An exhaust emission survey was conducted on a double-annular ram induction combustor at simulated ground idle conditions. The combustor was designed for a large augmented turbofan engine capable of sustained flight speeds up to Mach 3.0. The emission levels of total hydrocarbon (THC), carbon monoxide, carbon dioxide, and nitric oxide were measured. The effects of fuel zoning, fuel nozzle design, and operating conditions (inlet temperature and reference Mach number) on the level of these emissions were determined. At an overall combustor fuel/air ratio of 0.007, fuel zoning reduced THC emissions by a factor of 5 to 1. The reduction in THC emissions is attributed to the increase in local fuel/air ratio provided by the fuel zoning. An alternative method of increasing fuel/air ratio would be to operate with larger-than-normal compressor overboard bleed; however, analysis on this method indicated an increase in idle fuel consumption of 20 percent. The use of air-atomizing nozzles reduced the THC emissions by 2 to 1.

Design and characterization of an RF excited micro atmospheric pressure plasma jet for reference in plasma medicine

NASA Astrophysics Data System (ADS)

Schulz-von der Gathen, Volker

2015-09-01

Over the last decade a huge variety of atmospheric pressure plasma jets has been developed and applied for plasma medicine. The efficiency of these non-equilibrium plasmas for biological application is based on the generated amounts of reactive species and radiation. The gas temperatures stay within a range tolerable for temperature-sensitive tissues. The variety of different discharge geometries complicates a direct comparison. In addition, in plasma-medicine the combination of plasma with reactive components, ambient air, as well as biologic tissue - typically also incorporating fluids - results in a complex system. Thus, real progress in plasma-medicine requires a profound knowledge of species, their fluxes and processes hitting biological tissues. That will allow in particular the necessary tailoring of the discharge to fit the conditions. The complexity of the problem can only be overcome by a common effort of many groups and requires a comparison of their results. A reference device based on the already well-investigated micro-scaled atmospheric pressure plasma jet is presented. It is developed in the frame of the European COST initiative MP1101 to establish a publicly available, stable and reproducible source, where required plasma conditions can be investigated. Here we present the design and the ideas behind. The presentation discusses the requirements for the reference source and operation conditions. Biological references are also defined by the initiative. A specific part of the talk will be attributed to the reproducibility of results from various samples of the device. Funding by the DFG within the Package Project PAK816 ``Plasma Cell Interaction in Dermatology'' and the Research Unit FOR 1123 ``Physics of microplasmas'' is gratefully acknowledged.

40 CFR 63.126 - Transfer operations provisions-reference control technology.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Wastewater § 63.126 Transfer operations provisions—reference control technology. (a) For each Group 1... control device. (1) Each vapor collection system shall be designed and operated to collect the organic... process, fuel gas system, or control device shall be operating. (b) For each Group 1 transfer rack the...

Performance Evaluation of UPQC under Nonlinear Unbalanced Load Conditions Using Synchronous Reference Frame Based Control

NASA Astrophysics Data System (ADS)

Kota, Venkata Reddy; Vinnakoti, Sudheer

2017-12-01

Today, maintaining Power Quality (PQ) is very important in the growing competent world. With new equipments and devices, new challenges are also being put before power system operators. Unified Power Quality Conditioner (UPQC) is proposed to mitigate many power quality problems and to improve the performance of the power system. In this paper, an UPQC with Fuzzy Logic controller for capacitor voltage balancing is proposed in Synchronous Reference Frame (SRF) based control with Modified Phased Locked Loop (MPLL). The proposed controller with SRF-MPLL based control is tested under non-linear and unbalanced load conditions. The system is developed in Matlab/Simulink and its performance is analyzed under various conditions like non-linear, unbalanced load and polluted supply voltage including voltage sag/swells. Active and reactive power flow in the system, power factor and %THD of voltages and currents before and after compensation are also analyzed in this work. Results prove the applicability of the proposed scheme for power quality improvement. It is observed that the fuzzy controller gives better performance than PI controller with faster capacitor voltage balancing and also improves the dynamic performance of the system.

Development of a Korean reference HLW disposal system under the Korean representative geologic conditions

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

Choi, Heui-Joo; Lee, Jong Youl; Choi, Jongwon

2007-07-01

The development of a Korean Reference disposal System for the spent fuels from PWR and CANDU reactors is outlined in this paper. Around 36,000 tU of spent fuels are being projected based on the lifetimes of 28 nuclear power reactors in Korea. Since the site for the geological disposal has not yet been decided, a hypothetical site with representative Korean geologic conditions is proposed for the conceptual design of the repository. The disposal rates of the spent fuels are determined according to the total operation time of 55 years. The canisters are optimized by considering natural Korean conditions, and themore » buffer is designed with domestic Ca-bentonite. The depth of the repository is determined to be 500 m below the ground's surface. The canister separation distances are determined through a thermal analysis. The main features of the repository are presented from the layout to the closure. A computer program has been developed to calculate and analyze the volume and the area of the disposal system to help in the cost analysis. The final output of the design is presented as a unit disposal cost, US $315 /kgU. (authors)« less

A new adaptive light beam focusing principle for scanning light stimulation systems.

PubMed

Bitzer, L A; Meseth, M; Benson, N; Schmechel, R

2013-02-01

In this article a novel principle to achieve optimal focusing conditions or rather the smallest possible beam diameter for scanning light stimulation systems is presented. It is based on the following methodology: First, a reference point on a camera sensor is introduced where optimal focusing conditions are adjusted and the distance between the light focusing optic and the reference point is determined using a laser displacement sensor. In a second step, this displacement sensor is used to map the topography of the sample under investigation. Finally, the actual measurement is conducted, using optimal focusing conditions in each measurement point at the sample surface, that are determined by the height difference between camera sensor and the sample topography. This principle is independent of the measurement values, the optical or electrical properties of the sample, the used light source, or the selected wavelength. Furthermore, the samples can be tilted, rough, bent, or of different surface materials. In the following the principle is implemented using an optical beam induced current system, but basically it can be applied to any other scanning light stimulation system. Measurements to demonstrate its operation are shown, using a polycrystalline silicon solar cell.

Design and Testing of a Controller for the Martian Atmosphere Pressure and Humidity Instrument DREAMS-P/H

NASA Astrophysics Data System (ADS)

Tapani Nikkanen, Timo; Schmidt, Walter; Genzer, Maria; Harri, Ari-Matti; Haukka, Harri

2013-04-01

The European Space Agency (ESA), driven by the goal of performing a soft landing on Mars, is planning to launch the Entry, descent and landing Demonstrator Module (EDM)[1] simultaneously with the Trace Gas Orbiter (TGO) as a part of the ExoMars program towards Mars in 2016. As a secondary objective, the EDM will gather meteorological data and observe the electrical environment of the landing site with its Dust characterisation, Risk assessment, and Environmental Analyser on the Martian Surface (DREAMS). The Finnish Meteorological Institute (FMI) is participating in the project by designing, building and testing a pressure and a humidity instrument for Mars, named DREAMS-P and DREAMS-H, respectively. The instruments are based on previous FMI designs, including ones flown on board the Huygens, Phoenix and Mars Science Laboratory.[2] Traditionally, the FMI pressure and humidity instruments have been controlled by an FPGA. However, the need to incorporate more autonomy and modifiability into instruments, cut the development time and component costs, stimulated interest to study a Commercial Off-The-Shelf (COTS) Microcontroller Unit (MCU) based instrument design. Thus, in the DREAMS-P/H design, an automotive MCU is used as the instrument controller. The MCU has been qualified for space by tests in and outside FMI. The DREAMS-P/H controller command and data interface utilizes a RS-422 connection to receive telecommands from and to transmit data to the Central Electronics Unit (CEU) of the DREAMS science package. The two pressure transducers of DREAMS-P and one humidity transducer of DREAMS-H are controlled by a single MCU. The MCU controls the power flow for each transducer and performs pulse counting measurements on sensor and reference channels to retrieve scientific data. Pressure and humidity measurements are scheduled and set up according to a configuration table assigned to each transducer. The configuration tables can be modified during the flight. The whole software is entirely interrupt driven, thus the MCU goes into a power saving standby mode whenever possible. Any measurement or other operation can be stopped by simply interrupting the controller with a telecommand. Software and functional tests of the DREAMS-P/H controller are needed to verify the performance of the instrument in nominal conditions and the correct operation and error detection in anomalous conditions. The nominal conditions tests range from simple functional and performance tests, to longer simulations of continued operation and measurements. Continued operation simulations can be implemented by executing accelerated runs of the expected normal measurement cycles. On the contrary, anomalous conditions tests are used to verify that the controller can handle bad telecommands or anomalous operation of the instrument transducers, for example in the case of malfunctioning sensors. Bad telecommand tests are done by feeding illegal parameters or scrambled telecommands to the controller. Malfunctioning sensors can be simulated by modifying the signals coming from the sensors and reference channels. All expected use cases and all imagined unexpected operating circumstances are studied to ensure that the system is robust. This also makes the planned modification of the design for other future missions easier and safer. Reference: [1] ESA ExoMars EDM mission: http://exploration.esa.int/science-e/www/object/index.cfm?fobjectid=47852 [2] FMI Space Projects website: http://space.fmi.fi/index.php?id=23

Mass Gauging Demonstrator for Any Gravitational Conditions

NASA Technical Reports Server (NTRS)

Korman, Valentin (Inventor); Pedersen, Kevin W. (Inventor); Witherow, William K. (Inventor)

2013-01-01

The present invention is a mass gauging interferometry system used to determine the volume contained within a tank. By using an optical interferometric technique to determine gas density and/or pressure a much smaller compression volume or higher fidelity measurement is possible. The mass gauging interferometer system is comprised of an optical source, a component that splits the optical source into a plurality of beams, a component that recombines the split beams, an optical cell operatively coupled to a tank, a detector for detecting fringes, and a means for compression. A portion of the beam travels through the optical cell operatively coupled to the tank, while the other beam(s) is a reference.

Optimization study for high speed radial turbine with special reference to design variables

NASA Technical Reports Server (NTRS)

Khalil, I.; Tabakoff, W.

1977-01-01

Numerical results of a theoretical investigation are presented to provide information about the effect of variation of the different design and operating parameters on radial inflow turbine performance. The effects of variations in the mass flow rate, rotor tip Mach number, inlet flow angles, number of rotor blades and hub to shroud radius ratio, on the internal fluid dynamics of turbine rotors, was investigated. A procedure to estimate the flow deviation angles at the turbine exit is also presented and used to examine the influence of the operating conditions and the rotor geometrical configuration on these deviations. The significance of the results obtained is discussed with respect to improved turbine performance.

Suspended sediment transport under estuarine tidal channel conditions

USGS Publications Warehouse

Sternberg, R.W.; Kranck, K.; Cacchione, D.A.; Drake, D.E.

1988-01-01

A modified version of the GEOPROBE tripod has been used to monitor flow conditions and suspended sediment distribution in the bottom boundary layer of a tidal channel within San Francisco Bay, California. Measurements were made every 15 minutes over three successive tidal cycles. They included mean velocity profiles from four electromagnetic current meters within 1 m of the seabed; mean suspended sediment concentration profiles from seven miniature nephelometers operated within 1 m of the seabed; near-bottom pressure fluctuations; vertical temperature gradient; and bottom photographs. Additionally, suspended sediment was sampled from four levels within 1 m of the seabed three times during each successive flood and ebb cycle. While the instrument was deployed, STD-nephelometer measurements were made throughout the water column, water samples were collected each 1-2 hours, and bottom sediment was sampled at the deployment site. From these measurements, estimates were made of particle settling velocity (ws) from size distributions of the suspended sediment, friction velocity (U*) from the velocity profiles, and reference concentration (Ca) was measured at z = 20 cm. These parameters were used in the suspended sediment distribution equations to evaluate their ability to predict the observed suspended sediment profiles. Three suspended sediment particle conditions were evaluated: (1) individual particle size in the 4-11 ?? (62.5-0.5 ??m) range with the reference concentration Ca at z = 20 cm (C??), (2) individual particle size in the 4-6 ?? size range, flocs representing the 7-11 ?? size range with the reference concentration Ca at z = 20 cm (Cf), and (3) individual particle size in the 4-6 ?? size range, flocs representing the 7-11 ?? size range with the reference concentration predicted as a function of the bed sediment size distribution and the square of the excess shear stress. In addition, computations of particle flux were made in order to show vertical variations in horizontal mass flux for varying flow conditions. ?? 1988.

Aeration optimization through operation at low dissolved oxygen concentrations: Evaluation of oxygen mass transfer dynamics in different activated sludge systems.

PubMed

Fan, Haitao; Qi, Lu; Liu, Guoqiang; Zhang, Yuankai; Fan, Qiang; Wang, Hongchen

2017-05-01

In wastewater treatment plants (WWTPs) using the activated sludge process, two methods are widely used to improve aeration efficiency - use of high-efficiency aeration devices and optimizing the aeration control strategy. Aeration efficiency is closely linked to sludge characteristics (such as concentrations of mixed liquor suspended solids (MLSS) and microbial communities) and operating conditions (such as air flow rate and operational dissolved oxygen (DO) concentrations). Moreover, operational DO is closely linked to effluent quality. This study, which is in reference to WWTP discharge class A Chinese standard effluent criteria, determined the growth kinetics parameters of nitrifiers at different DO levels in small-scale tests. Results showed that the activated sludge system could meet effluent criteria when DO was as low as 0.3mg/L, and that nitrifier communities cultivated under low DO conditions had higher oxygen affinity than those cultivated under high DO conditions, as indicated by the oxygen half-saturation constant and nitrification ability. Based on nitrifier growth kinetics and on the oxygen mass transfer dynamic model (determined using different air flow rate (Q' air ) and mixed liquor volatile suspended solids (MLVSS) values), theoretical analysis indicated limited potential for energy saving by improving aeration diffuser performance when the activated sludge system had low oxygen consumption; however, operating at low DO and low MLVSS could significantly reduce energy consumption. Finally, a control strategy coupling sludge retention time and MLVSS to minimize the DO level was discussed, which is critical to appropriate setting of the oxygen point and to the operation of low DO treatment technology. Copyright © 2016. Published by Elsevier B.V.

Aircraft Weather Mitigation for the Next Generation Air Transportation System

NASA Technical Reports Server (NTRS)

Stough, H. Paul, III

2007-01-01

Atmospheric effects on aviation are described by Mahapatra (1999) as including (1) atmospheric phenomena involving air motion - wind shear and turbulence; (2) hydrometeorological phenomena - rain, snow and hail; (3) aircraft icing; (4) low visibility; and (5) atmospheric electrical phenomena. Aircraft Weather Mitigation includes aircraft systems (e.g. airframe, propulsion, avionics, controls) that can be enacted (by a pilot, automation or hybrid systems) to suppress and/or prepare for the effects of encountered or unavoidable weather or to facilitate a crew operational decision-making process relative to weather. Aircraft weather mitigation can be thought of as a continuum (Figure 1) with the need to avoid all adverse weather at one extreme and the ability to safely operate in all weather conditions at the other extreme. Realistic aircraft capabilities fall somewhere between these two extremes. The capabilities of small general aviation aircraft would be expected to fall closer to the "Avoid All Adverse Weather" point, and the capabilities of large commercial jet transports would fall closer to the "Operate in All Weather Conditions" point. The ability to safely operate in adverse weather conditions is dependent upon the pilot s capabilities (training, total experience and recent experience), the airspace in which the operation is taking place (terrain, navigational aids, traffic separation), the capabilities of the airport (approach guidance, runway and taxiway lighting, availability of air traffic control), as well as the capabilities of the airplane. The level of mitigation may vary depending upon the type of adverse weather. For example, a small general aviation airplane may be equipped to operate "in the clouds" without outside visual references, but not be equipped to prevent airframe ice that could be accreted in those clouds.

A low-voltage sense amplifier with two-stage operational amplifier clamping for flash memory

NASA Astrophysics Data System (ADS)

Guo, Jiarong

2017-04-01

A low-voltage sense amplifier with reference current generator utilizing two-stage operational amplifier clamp structure for flash memory is presented in this paper, capable of operating with minimum supply voltage at 1 V. A new reference current generation circuit composed of a reference cell and a two-stage operational amplifier clamping the drain pole of the reference cell is used to generate the reference current, which avoids the threshold limitation caused by current mirror transistor in the traditional sense amplifier. A novel reference voltage generation circuit using dummy bit-line structure without pull-down current is also adopted, which not only improves the sense window enhancing read precision but also saves power consumption. The sense amplifier was implemented in a flash realized in 90 nm flash technology. Experimental results show the access time is 14.7 ns with power supply of 1.2 V and slow corner at 125 °C. Project supported by the National Natural Science Fundation of China (No. 61376028).

Hematology and Serum Biochemistry Reference Intervals for Six-Week-Old, Farm-Reared Chinese Ring-Necked Pheasants ( Phasianus colchicus ) from Minnesota.

PubMed

Dzikamunhenga, R S; Griffith, R W; Hostetter, S; Fisher, P; Larson, W

2017-06-01

Chinese ring-necked pheasants ( Phasianus colchicus ) are commonly farmed in intensive operations for purposes such as meat production, hunting preserves, or research. Under these conditions, pheasants frequently suffer medical ailments such as bacterial, viral, and parasitic infections or nutritional or metabolic disorders. Relatively little scientific information exists regarding clinical pathology reference intervals (RIs) for farm-reared pheasants. The objective of this study was to determine RIs for hematologic and serum biochemical variables for Chinese ring-necked pheasants from Minnesota at 6 wk of age. Blood samples from 119 clinically healthy Chinese ring-necked pheasants were analyzed using standard techniques. Reference intervals were generated in Microsoft® Excel® 2013 (Microsoft, Redmond, WA) using Reference Value Advisor freeware version 2.1 (Microsoft). Ninety-five percent RIs were determined using nonparametric methods that followed Clinical and Laboratory Standards Institute guidelines. These RIs will be useful for the monitoring of health and diagnosis of disease in confined Chinese ring-necked pheasant populations that are approximately 6 wk old.

Passive field reflectance measurements

NASA Astrophysics Data System (ADS)

Weber, Christian; Schinca, Daniel C.; Tocho, Jorge O.; Videla, Fabian

2008-10-01

The results of reflectance measurements performed with a three-band passive radiometer with independent channels for solar irradiance reference are presented. Comparative operation between the traditional method that uses downward-looking field and reference white panel measurements and the new approach involving duplicated downward- and upward-looking spectral channels (each latter one with its own diffuser) is analyzed. The results indicate that the latter method performs in very good agreement with the standard method and is more suitable for passive sensors under rapidly changing atmospheric conditions (such as clouds, dust, mist, smog and other scatterers), since a more reliable synchronous recording of reference and incident light is achieved. Besides, having separate channels for the reference and the signal allows a better balancing of gains in the amplifiers for each spectral channel. We show the results obtained in the determination of the normalized difference vegetation index (NDVI) corresponding to the period 2004-2007 field experiments concerning weed detection in soybean stubbles and fertilizer level assessment in wheat. The method may be used to refine sensor-based nitrogen fertilizer rate recommendations and to determine suitable zones for herbicide applications.

US Fish and Wildlife Service biomonitoring operations manual, Appendices A--K

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

Gianotto, D.F.; Rope, R.C.; Mondecar, M.

1993-04-01

Volume 2 contains Appendices and Summary Sheets for the following areas: A-Legislative Background and Key to Relevant Legislation, B- Biomonitoring Operations Workbook, C-Air Monitoring, D-Introduction to the Flora and Fauna for Biomonitoring, E-Decontamination Guidance Reference Field Methods, F-Documentation Guidance, Sample Handling, and Quality Assurance/Quality Control Standard Operating Procedures, G-Field Instrument Measurements Reference Field Methods, H-Ground Water Sampling Reference Field Methods, I-Sediment Sampling Reference Field Methods, J-Soil Sampling Reference Field Methods, K-Surface Water Reference Field Methods. Appendix B explains how to set up strategy to enter information on the ``disk workbook``. Appendix B is enhanced by DE97006389, an on-line workbook formore » users to be able to make revisions to their own biomonitoring data.« less

Summary of Notifiable Infectious Diseases and Conditions - United States, 2015.

PubMed

Adams, Deborah A; Thomas, Kimberly R; Jajosky, Ruth Ann; Foster, Loretta; Baroi, Gitangali; Sharp, Pearl; Onweh, Diana H; Schley, Alan W; Anderson, Willie J

2017-08-11

The Summary of Notifiable Infectious Diseases and Conditions - United States, 2015 (hereafter referred to as the summary) contains the official statistics, in tabular and graphical form, for the reported occurrence of nationally notifiable infectious diseases and conditions in the United States for 2015. Unless otherwise noted, data are final totals for 2015 reported as of June 30, 2016. These statistics are collected and compiled from reports sent by U.S. state and territories, New York City, and District of Columbia health departments to the National Notifiable Diseases Surveillance System (NNDSS), which is operated by CDC in collaboration with the Council of State and Territorial Epidemiologists (CSTE). This summary is available at https://www.cdc.gov/MMWR/MMWR_nd/index.html. This site also includes summary publications from previous years.

Summary of Notifiable Infectious Diseases and Conditions - United States, 2013.

PubMed

Adams, Deborah; Fullerton, Kathleen; Jajosky, Ruth; Sharp, Pearl; Onweh, Diana; Schley, Alan; Anderson, Willie; Faulkner, Amanda; Kugeler, Kiersten

2015-10-23

The Summary of Notifiable Infectious Diseases and Condition-United States, 2013 (hereafter referred to as the summary) contains the official statistics, in tabular and graphic form, for the reported occurrence of nationally notifiable infectious diseases and conditions in the United States for 2013. Unless otherwise noted, data are final totals for 2013 reported as of June 30, 2014. These statistics are collected and compiled from reports sent by U.S. state and territory, New York City, and District of Columbia health departments to the National Notifiable Diseases Surveillance System (NNDSS), which is operated by CDC in collaboration with the Council of State and Territorial Epidemiologists (CSTE). This summary is available at http://www.cdc.gov/mmwr/mmwr_nd/index.html. This site also includes summary publications from previous years.

Summary of Notifiable Infectious Diseases and Conditions - United States, 2014.

PubMed

Adams, Deborah A; Thomas, Kimberly R; Jajosky, Ruth Ann; Foster, Loretta; Sharp, Pearl; Onweh, Diana H; Schley, Alan W; Anderson, Willie J

2016-10-14

The Summary of Notifiable Infectious Diseases and Conditions-United States, 2014 (hereafter referred to as the summary) contains the official statistics, in tabular and graphic form, for the reported occurrence of nationally notifiable infectious diseases and conditions in the United States for 2014. Unless otherwise noted, data are final totals for 2014 reported as of June 30, 2015. These statistics are collected and compiled from reports sent by U.S. state and territory, New York City, and District of Columbia health departments to the National Notifiable Diseases Surveillance System (NNDSS), which is operated by CDC in collaboration with the Council of State and Territorial Epidemiologists (CSTE). This summary is available at http://www.cdc.gov/mmwr/mmwr_nd/index.html. This site also includes summary publications from previous years.

The land management and operations database (LMOD)

USDA-ARS?s Scientific Manuscript database

This paper presents the design, implementation, deployment, and application of the Land Management and Operations Database (LMOD). LMOD is the single authoritative source for reference land management and operation reference data within the USDA enterprise data warehouse. LMOD supports modeling appl...

The Value of Biomedical Simulation Environments to Future Human Space Flight Missions

NASA Technical Reports Server (NTRS)

Mulugeta, Lealem; Myers, Jerry G.; Skytland, Nicholas G.; Platts, Steven H.

2010-01-01

With the ambitious goals to send manned missions to asteroids and onto Mars, substantial work will be required to ensure the well being of the men and women who will undertake these difficult missions. Unlike current International Space Station or Shuttle missions, astronauts will be required to endure long-term exposure to higher levels of radiation, isolation and reduced gravity. These new operation conditions will pose health risks that are currently not well understood and perhaps unanticipated. Therefore, it is essential to develop and apply advanced tools to predict, assess and mitigate potential hazards to astronaut health. NASA s Digital Astronaut Project (DAP) is working to develop and apply computational models of physiologic response to space flight operation conditions over various time periods and environmental circumstances. The collective application and integration of well vetted models assessing the physiology, biomechanics and anatomy is referred to as the Digital Astronaut. The Digital Astronaut simulation environment will serve as a practical working tool for use by NASA in operational activities such as the prediction of biomedical risks and functional capabilities of astronauts. In additional to space flight operation conditions, DAP s work has direct applicability to terrestrial biomedical research by providing virtual environments for hypothesis testing, experiment design, and to reduce animal/human testing. A practical application of the DA to assess pre and post flight responses to exercise is illustrated and the difficulty in matching true physiological responses is discussed.

Analysis on burnup step effect for evaluating reactor criticality and fuel breeding ratio

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

Saputra, Geby; Purnama, Aditya Rizki; Permana, Sidik

Criticality condition of the reactors is one of the important factors for evaluating reactor operation and nuclear fuel breeding ratio is another factor to show nuclear fuel sustainability. This study analyzes the effect of burnup steps and cycle operation step for evaluating the criticality condition of the reactor as well as the performance of nuclear fuel breeding or breeding ratio (BR). Burnup step is performed based on a day step analysis which is varied from 10 days up to 800 days and for cycle operation from 1 cycle up to 8 cycles reactor operations. In addition, calculation efficiency based onmore » the variation of computer processors to run the analysis in term of time (time efficiency in the calculation) have been also investigated. Optimization method for reactor design analysis which is used a large fast breeder reactor type as a reference case was performed by adopting an established reactor design code of JOINT-FR. The results show a criticality condition becomes higher for smaller burnup step (day) and for breeding ratio becomes less for smaller burnup step (day). Some nuclides contribute to make better criticality when smaller burnup step due to individul nuclide half-live. Calculation time for different burnup step shows a correlation with the time consuming requirement for more details step calculation, although the consuming time is not directly equivalent with the how many time the burnup time step is divided.« less

Initial Piloted Simulation Evaluation of the Reference-H High-Speed Civil Transport Design During Takeoff and Recovery From Limit Flight Conditions

NASA Technical Reports Server (NTRS)

Glaab, Louis J.

1999-01-01

An initial assessment of a proposed High-Speed Civil Transport (HSCT) was conducted in the fall of 1995 at the NASA Langley Research Center. This configuration, known as the Industry Reference-H (Ref.-H), was designed by the Boeing Aircraft Company as part of their work in the High Speed Research program. It included a conventional tail, a cranked-arrow wing, four mixed-flow turbofan engines, and capacity for transporting approximately 300 passengers. The purpose of this assessment was to evaluate and quantify operational aspects of the Reference-H configuration from a pilot's perspective with the additional goal of identifying design strengths as well as any potential configuration deficiencies. This study was aimed at evaluating the Ref.-H configuration at many points of the aircraft's envelope to determine the suitability of the vehicle to accomplish typical mission profiles as well as emergency or envelope-limit conditions. Pilot-provided Cooper-Harper ratings and comments constituted the primary vehicle evaluation metric. The analysis included simulated real-time piloted evaluations, performed in a 6 degree of freedom motion base NASA Langley Visual-Motion Simulator, combined with extensive bath analysis. The assessment was performed using the third major release of the simulation data base (known as Ref.-H cycle 2B).

Skylab reuse study, reference data, part 1. [habitability of the orbital workshop and airlock modules for the space transportation system

NASA Technical Reports Server (NTRS)

1978-01-01

The accommodations provided by the airlock module and the orbital workshop were completely examined with the thought of total reactivation as an enhancement to the STS long duration missions. Each subsystem is described and a summary of subsystem performance during the Skylab missions is presented. End-of-mission status and the status of today for each subsystem is shown together with refurbishment/resupply requirements and refurb kit descriptions to restore Skylab to full operational capability. An inspection/refurbishment and operations plan for Skylab is included. The initial Shuttle-tended operational activity would provide a safe, effective phase of Skylab rehabilitation while simultaneously benefitting the Orbiter crew through the addition of private accommodations, off-duty recreation area, and physical conditioning equipment. This period would also permit exercising selected onboard experiments.

Adaptive control of a jet turboshaft engine driving a variable pitch propeller using multiple models

NASA Astrophysics Data System (ADS)

Ahmadian, Narjes; Khosravi, Alireza; Sarhadi, Pouria

2017-08-01

In this paper, a multiple model adaptive control (MMAC) method is proposed for a gas turbine engine. The model of a twin spool turbo-shaft engine driving a variable pitch propeller includes various operating points. Variations in fuel flow and propeller pitch inputs produce different operating conditions which force the controller to be adopted rapidly. Important operating points are three idle, cruise and full thrust cases for the entire flight envelope. A multi-input multi-output (MIMO) version of second level adaptation using multiple models is developed. Also, stability analysis using Lyapunov method is presented. The proposed method is compared with two conventional first level adaptation and model reference adaptive control techniques. Simulation results for JetCat SPT5 turbo-shaft engine demonstrate the performance and fidelity of the proposed method.

Study on Calculation of Liquid Level And Storage of Tanks for LNG-fueled Vessels

NASA Astrophysics Data System (ADS)

Li, Kun; Wang, Guoqing; Liu, Chang

2018-01-01

As the ongoing development of the application of LNG as a clean energy in waterborne transport industry, the fleet scale of LNG-fueled vessels enlarged and the safety operation has attracted more attention in the industry. Especially the accurate detection of liquid level of LNG tanks is regarded as an important issue to ensure a safe and stable operation of LNG-fueled ships and a key parameter to keep the proper functioning of marine fuel storage system, supply system and safety control system. At present, detection of LNG tank liquid level mainly adopts differential pressure detection method. Liquid level condition could be found from the liquid level reference tables. However in practice, since LNG-fueled vessels are generally not in a stationary state, liquid state within the LNG tanks will constantly change, the detection of storage of tanks only by reference to the tables will cause deviation to some extent. By analyzing the temperature under different pressure, the effects of temperature change on density and volume integration calculation, a method of calculating the liquid level and storage of LNG tanks is put forward making the calculation of liquid level and actual storage of LNG tanks more accurately and providing a more reliable basis for the calculation of energy consumption level and operation economy for LNG-fueled vessels.

A novel bench-scale column assay to investigate site-specific nitrification biokinetics in biological rapid sand filters.

PubMed

Tatari, K; Smets, B F; Albrechtsen, H-J

2013-10-15

A bench-scale assay was developed to obtain site-specific nitrification biokinetic information from biological rapid sand filters employed in groundwater treatment. The experimental set-up uses granular material subsampled from a full-scale filter, packed in a column, and operated with controlled and continuous hydraulic and ammonium loading. Flowrates and flow recirculation around the column are chosen to mimic full-scale hydrodynamic conditions, and minimize axial gradients. A reference ammonium loading rate is calculated based on the average loading experienced in the active zone of the full-scale filter. Effluent concentrations of ammonium are analyzed when the bench-scale column is subject to reference loading, from which removal rates are calculated. Subsequently, removal rates above the reference loading are measured by imposing short-term loading variations. A critical loading rate corresponding to the maximum removal rate can be inferred. The assay was successfully applied to characterize biokinetic behavior from a test rapid sand filter; removal rates at reference loading matched those observed from full-scale observations, while a maximum removal capacity of 6.9 g NH4(+)-N/m(3) packed sand/h could easily be determined at 7.5 g NH4(+)-N/m(3) packed sand/h. This assay, with conditions reflecting full-scale observations, and where the biological activity is subject to minimal physical disturbance, provides a simple and fast, yet powerful tool to gain insight in nitrification kinetics in rapid sand filters. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assessing and Evaluating Department of Defense Efforts to Inform, Influence, and Persuade: Desk Reference

DTIC Science & Technology

2015-01-01

128 O’Hanlon, Michael, 187n107 OIF (Operation Iraqi Freedom), 1, 299 Olshefsky, Alisa M., 308n39 one - group pretest - posttest design, 154–155 online...procedures may result in differences between the pretest and posttest . Hawthorne effect Subjects may react positively to being part of the treatment group ...and Devra Moehler, used a four- group posttest -only design with two controls. Tro tro riders in Ghana were randomized to one of four conditions: a

Long-Term Effects of Dredging Operations Program. Biological Consequences of Bioaccumulation in Aquatic Animals: An Assessment of the Current Literature

DTIC Science & Technology

1984-06-01

at which an effect was first ob- served. The response parameters of growth, reproduction, and some measure of metabolism , such as scope for growth...Aspects of physiological condition in Mytilus edulis L., with special reference to the effects of oxygen tension and salinity . In: Proceed. 9th Europ. Mar...estuarine teleost fish, Gillichthgs mirabilis: Salinity and temperature effects . Arch. Environ. Contam. Toxicol. 6:337-348. Somero, G. N., P. H. Yancey, T

Reproducibility of total ozone column monitoring by the Arosa Brewer spectrophotometer triad

NASA Astrophysics Data System (ADS)

Stübi, R.; Schill, H.; Klausen, J.; Vuilleumier, L.; Ruffieux, D.

2017-04-01

The historical review of the total ozone column measurements with the Arosa Brewer triad in operation since 1998 is presented. The calibration history of the different instruments and the data quality control performed at Arosa are described. Over the last 15 years, the Brewer triad shows a dispersion of ˜0.4% between the three collocated instruments and a long-term stability of ±0.5%. These values are a reference metric achievable with well-maintained Brewer instruments under favorable measurement conditions.

[Surgical treatment of esophageal achalasia--20 years experience].

PubMed

Yaramov, N; Sokolov, M; Angelov, K; Toshev, S; Petrov, B

2009-01-01

Achalasia comes from a Greek word that means "failure to relax." Cardiospasm and achalasia refer to the same condition. This report addresses esophageal achalasia--its history, diagnosis, pathophysiology, and treatment options. We report our experience in treating this disorder surgically using modified Heller myotomy combined or not with partial gastric fundoplication. 47 patients with achalasia surgically operated in 20-years period are reported by authors. These features make it reasonable to reasses the relative indications for surgery and nonsurgical therapy in achalasia of the esophagus.

CPLOAS_2 user manual

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

Sallaberry, Cedric Jean-Marie.; Helton, Jon Craig

2012-10-01

Weak link (WL)/strong link (SL) systems are important parts of the overall operational design of high-consequence systems. In such designs, the SL system is very robust and is intended to permit operation of the entire system under, and only under, intended conditions. In contrast, the WL system is intended to fail in a predictable and irreversible manner under accident conditions and render the entire system inoperable before an accidental operation of the SL system. The likelihood that the WL system will fail to deactivate the entire system before the SL system fails (i.e., degrades into a configuration that could allowmore » an accidental operation of the entire system) is referred to as probability of loss of assured safety (PLOAS). This report describes the Fortran 90 program CPLOAS_2 that implements the following representations for PLOAS for situations in which both link physical properties and link failure properties are time-dependent: (i) failure of all SLs before failure of any WL, (ii) failure of any SL before failure of any WL, (iii) failure of all SLs before failure of all WLs, and (iv) failure of any SL before failure of all WLs. The effects of aleatory uncertainty and epistemic uncertainty in the definition and numerical evaluation of PLOAS can be included in the calculations performed by CPLOAS_2.« less

Evaluating physical habitat and water chemistry data from statewide stream monitoring programs to establish least-impacted conditions in Washington State

USGS Publications Warehouse

Wilmoth, Siri K.; Irvine, Kathryn M.; Larson, Chad

2015-01-01

Various GIS-generated land-use predictor variables, physical habitat metrics, and water chemistry variables from 75 reference streams and 351 randomly sampled sites throughout Washington State were evaluated for effectiveness at discriminating reference from random sites within level III ecoregions. A combination of multivariate clustering and ordination techniques were used. We describe average observed conditions for a subset of predictor variables as well as proposing statistical criteria for establishing reference conditions for stream habitat in Washington. Using these criteria, we determined whether any of the random sites met expectations for reference condition and whether any of the established reference sites failed to meet expectations for reference condition. Establishing these criteria will set a benchmark from which future data will be compared.

The intensity of knock in an internal combustion engine: An experimental and modeling study

NASA Astrophysics Data System (ADS)

Cowart, J. S.; Haghooie, M.; Newman, C. E.; Davis, G. C.; Pitz, W. J.; Westbrook, C. K.

1992-09-01

Experimental data have been obtained that characterize knock occurrence times and knock intensities in a spark ignition engine operating on indolene and 91 primary reference fuel, as spark timing and inlet temperature were varied. Individual, in-cylinder pressure histories measured under knocking conditions were conditioned and averaged to obtain representative pressure traces. These averaged pressure histories were used as input to a reduced and detailed chemical kinetic model. The time derivative of CO concentration and temperature were correlated with the measured knock intensity and percent cycles knocking. The goal was to evaluate the potential of using homogeneous, chemical kinetic models as predictive tools for knock intensity.

Calibration of the heat balance model for prediction of car climate

NASA Astrophysics Data System (ADS)

Pokorný, Jan; Fišer, Jan; Jícha, Miroslav

2012-04-01

In the paper, the authors refer to development a heat balance model to predict car climate and power heat load. Model is developed in Modelica language using Dymola as interpreter. It is a dynamical system, which describes a heat exchange between car cabin and ambient. Inside a car cabin, there is considered heat exchange between air zone, interior and air-conditioning system. It is considered 1D heat transfer with a heat accumulation and a relative movement Sun respect to the car cabin, whilst car is moving. Measurements of the real operating conditions of gave us data for model calibration. The model was calibrated for Škoda Felicia parking-summer scenarios.

Further evaluation of traditional icing scaling methods

NASA Technical Reports Server (NTRS)

Anderson, David N.

1996-01-01

This report provides additional evaluations of two methods to scale icing test conditions; it also describes a hybrid technique for use when scaled conditions are outside the operating envelope of the test facility. The first evaluation is of the Olsen method which can be used to scale the liquid-water content in icing tests, and the second is the AEDC (Ruff) method which is used when the test model is less than full size. Equations for both scaling methods are presented in the paper, and the methods were evaluated by performing icing tests in the NASA Lewis Icing Research Tunnel (IRT). The Olsen method was tested using 53 cm diameter NACA 0012 airfoils. Tests covered liquid-water-contents which varied by as much as a factor of 1.8. The Olsen method was generally effective in giving scale ice shapes which matched the reference shapes for these tests. The AEDC method was tested with NACA 0012 airfoils with chords from 18 cm to 53 cm. The 53 cm chord airfoils were used in reference tests, and 1/2 and 1/3 scale tests were made at conditions determined by applying the AEDC scaling method. The scale and reference airspeeds were matched in these tests. The AEDC method was found to provide fairly effective scaling for 1/2 size tests, but for 1/3 size models, scaling was generally less effective. In addition to these two scaling methods, a hybrid approach was also tested in which the Olsen method was used to adjust the LWC after size was scaled using the constant Weber number method. This approach was found to be an effective way to test when scaled conditions would otherwise be outside the capability of the test facility.

Creep-Fatigue Failure Diagnosis

PubMed Central

Holdsworth, Stuart

2015-01-01

Failure diagnosis invariably involves consideration of both associated material condition and the results of a mechanical analysis of prior operating history. This Review focuses on these aspects with particular reference to creep-fatigue failure diagnosis. Creep-fatigue cracking can be due to a spectrum of loading conditions ranging from pure cyclic to mainly steady loading with infrequent off-load transients. These require a range of mechanical analysis approaches, a number of which are reviewed. The microstructural information revealing material condition can vary with alloy class. In practice, the detail of the consequent cracking mechanism(s) can be camouflaged by oxidation at high temperatures, although the presence of oxide on fracture surfaces can be used to date events leading to failure. Routine laboratory specimen post-test examination is strongly recommended to characterise the detail of deformation and damage accumulation under known and well-controlled loading conditions to improve the effectiveness and efficiency of failure diagnosis. PMID:28793676

Behaviour of a full-scale expanded bed reactor with overlaid anaerobic and aerobic zones for domestic wastewater treatment.

PubMed

Mendonça, N M; Siman, R R; Niciura, C L; Campos, J R

2006-01-01

This paper presents the behaviour of a full-scale expanded bed reactor (160 m3) with overlaid anaerobic and aerobic zones used for municipal wastewater treatment. The research was carried out in two experimental steps: anaerobic and anaerobic-aerobic conditions, and the experimental results presented in this paper refer to four months of reactor operation. In the anaerobic condition, after inoculation and 60 days of operation, the reactor treating 3.40 kg CODm(-3)d(-1) for thetaH of 2.69 h, reached mean removal efficiencies of 76% for BOD, 72% for COD, and 80% for TSS, when the effluent presented mean values of 225 mg.L(-1) of COD, 98 mg.L(-1) of BOD and 35 mg.L(-1) of TSS. Under these conditions, for nitrogen loading of 0.27 kgN.m(-3)d(-1), the reactor generated an effluent with mean N-org. of 8 mg.L(-1) and N-ammon. of 37 mg.L(-1), demonstrating high potential of ammonification. For the anaerobic-aerobic condition (118th day) the system was operated with thetaH of 5.38 h presented mean removal efficiencies of 84% for BOD, 79% for COD, 76% for TSS, and 30% for TKN. The reactor's operation time was less than two months, which was not long enough to reach nitrification. Regarding the obtained results, this research confirmed that this reactor is configured as a flexible and adequate alternative for the treatment of sewage, requiring relatively small area and only thetaH of 10 h that can be adjusted to the local circumstances.

Passive serialization in a multitasking environment

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

Hennessey, J.P.; Osisek, D.L.; Seigh, J.W. II

1989-02-28

In a multiprocessing system having a control program in which data objects are shared among processes, this patent describes a method for serializing references to a data object by the processes so as to prevent invalid references to the data object by any process when an operation requiring exclusive access is performed by another process, comprising the steps of: permitting the processes to reference data objects on a shared access basis without obtaining a shared lock; monitoring a point of execution of the control program which is common to all processes in the system, which occurs regularly in the process'more » execution and across which no references to any data object can be maintained by any process, except references using locks; establishing a system reference point which occurs after each process in the system has passed the point of execution at least once since the last such system reference point; requesting an operation requiring exclusive access on a selected data object; preventing subsequent references by other processes to the selected data object; waiting until two of the system references points have occurred; and then performing the requested operation.« less

THE CONCEPT OF REFERENCE CONDITION, REVISITED ...

EPA Pesticide Factsheets

Ecological assessments of aquatic ecosystems depend on the ability to compare current conditions against some expectation of how they could be in the absence of significant human disturbance. The concept of a ‘‘reference condition’’ is often used to describe the standard or benchmark against which current condition is compared. If assessments are to be conducted consistently, then a common understanding of the definitions and complications of reference condition is necessary. A 2006 paper (Stoddard et al., 2006, Ecological Applications 16:1267-1276) made an early attempt at codifying the reference condition concept; in this presentation we will revisit the points raised in that paper (and others) and examine how our thinking has changed in a little over 10 years.Among the issues to be discussed: (1) the “moving target” created when reference site data are used to set thresholds in large scale assessments; (2) natural vs. human disturbance and their effects on reference site distributions; (3) circularity and the use of biological data to assist in reference site identification; (4) using site-scale (in-stream or in-lake) measurements vs. landscape-level human activity to identify reference conditions. Ecological assessments of aquatic ecosystems depend on the ability to compare current conditions against some expectation of how they could be in the absence of significant human disturbance. The concept of a ‘‘reference condition’’ is often use

Evaluation of New Reference Genes in Papaya for Accurate Transcript Normalization under Different Experimental Conditions

PubMed Central

Chen, Weixin; Chen, Jianye; Lu, Wangjin; Chen, Lei; Fu, Danwen

2012-01-01

Real-time reverse transcription PCR (RT-qPCR) is a preferred method for rapid and accurate quantification of gene expression studies. Appropriate application of RT-qPCR requires accurate normalization though the use of reference genes. As no single reference gene is universally suitable for all experiments, thus reference gene(s) validation under different experimental conditions is crucial for RT-qPCR analysis. To date, only a few studies on reference genes have been done in other plants but none in papaya. In the present work, we selected 21 candidate reference genes, and evaluated their expression stability in 246 papaya fruit samples using three algorithms, geNorm, NormFinder and RefFinder. The samples consisted of 13 sets collected under different experimental conditions, including various tissues, different storage temperatures, different cultivars, developmental stages, postharvest ripening, modified atmosphere packaging, 1-methylcyclopropene (1-MCP) treatment, hot water treatment, biotic stress and hormone treatment. Our results demonstrated that expression stability varied greatly between reference genes and that different suitable reference gene(s) or combination of reference genes for normalization should be validated according to the experimental conditions. In general, the internal reference genes EIF (Eukaryotic initiation factor 4A), TBP1 (TATA binding protein 1) and TBP2 (TATA binding protein 2) genes had a good performance under most experimental conditions, whereas the most widely present used reference genes, ACTIN (Actin 2), 18S rRNA (18S ribosomal RNA) and GAPDH (Glyceraldehyde-3-phosphate dehydrogenase) were not suitable in many experimental conditions. In addition, two commonly used programs, geNorm and Normfinder, were proved sufficient for the validation. This work provides the first systematic analysis for the selection of superior reference genes for accurate transcript normalization in papaya under different experimental conditions. PMID:22952972

EVALUATION OF DATA OBTAINED ON "MANUFACTURING PROCESS" DEVELOPMENT BUNDLES PD 1 THROUGH 5 PRIOR TO MACHINING OPERATIONS

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

Frankhouser, W.L.; Eyler, J.H.

1956-07-24

Five reference fuel rod bundles were welded and evaluated dimensionally. Dimensional data are presented for the as-welded condition and for the annealed bundle with spacer strips removed (prior to the final machining operations). The welding sequence developed for Core Manufacturing should provide A'' boundles in respect to rod spacing measurements. It will probably not be possible to meet the same requirements for water channel averages, because the design tolerances are not consistent with some factors inherent to the production process. A method to improve this situation is presented. The data presented were evaluated in a fashion similar to that whichmore » would be used in the proposed scheme. Rods tended to bow resulting in a slightly barrel-shaped'' boundle. It is believed this condition can be overcome by providing special bundle peripheral clamps during annealing. Rod distortion should also be reduced by a redesign and relocation of strip spacers. The new design is proposed. (auth)« less

A comprehensive study of bubble inflation in vacuum-assisted thermoforming based on whole-field strain measurements

NASA Astrophysics Data System (ADS)

Ayadi, A.; Lacrampe, M.-F.; Krawczak, P.

2018-05-01

This paper focuses on the potential use of stereo-DIC in thermoforming conditions to monitor large deformations of softened thermoplastic sheets posteriori to the sagging phenomenon. The study concerns HIPS sheets which are softened by the radiative heat-transfer mode then stretched by inflation of compressed-air for 1.5 s to form a large and quasi-spherical dome of 250 mm in diameter. While the bubble-inflation operation leads to large deformations of the softened sheet, it shows transitional geometrical instabilities due to the initial surface sagging. When the temperature-induced surface deformations are inaccessible by the stereoscopic system during the heating operation, the geometrical instabilities limit the identification of the reference of displacements which affects the accuracy of results based on image-correlation computations. To compare between the principal strains assessed from bubble-inflation tests conducted at different thermal conditions, a method for filtering these instabilities is developed in this study.

The effect of water injection on nitric oxide emissions of a gas turbine combustor burning ASTM Jet-A fuel

NASA Technical Reports Server (NTRS)

Marchionna, N. R.; Diehl, L. A.; Trout, A. M.

1973-01-01

Tests were conducted to determine the effect of water injection on oxides of nitrogen (NOx) emissions of a full annular, ram induction gas turbine combustor burning ASTM Jet-A fuel. The combustor was operated at conditions simulating sea-level takeoff and cruise conditions. Water at ambient temperature was injected into the combustor primary zone at water-fuel ratios up to 2. At an inlet-air temperature of 589 K (600 F) water injection decreased the NOx emission index at a constant exponential rate: NOx = NOx (o) e to the -15 W/F power (where W/F is the water-fuel ratio and NOx(o) indicates the value with no injection). The effect of increasing combustor inlet-air temperature was to decrease the effect of the water injection. Other operating variables such as pressure and reference Mach number did not appear to significantly affect the percent reduction in NOx. Smoke emissions were found to decrease with increasing water injection.

Alternative Methods for Estimating Plane Parameters Based on a Point Cloud

NASA Astrophysics Data System (ADS)

Stryczek, Roman

2017-12-01

Non-contact measurement techniques carried out using triangulation optical sensors are increasingly popular in measurements with the use of industrial robots directly on production lines. The result of such measurements is often a cloud of measurement points that is characterized by considerable measuring noise, presence of a number of points that differ from the reference model, and excessive errors that must be eliminated from the analysis. To obtain vector information points contained in the cloud that describe reference models, the data obtained during a measurement should be subjected to appropriate processing operations. The present paperwork presents an analysis of suitability of methods known as RANdom Sample Consensus (RANSAC), Monte Carlo Method (MCM), and Particle Swarm Optimization (PSO) for the extraction of the reference model. The effectiveness of the tested methods is illustrated by examples of measurement of the height of an object and the angle of a plane, which were made on the basis of experiments carried out at workshop conditions.

Auralization of Hybrid Wing Body Aircraft Flyover Noise from System Noise Predictions

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Aumann, Aric R.; Lopes, Leonvard V.; Burley, Casey L.

2013-01-01

System noise assessments of a state-of-the-art reference aircraft (similar to a Boeing 777-200ER with GE90-like turbofan engines) and several hybrid wing body (HWB) aircraft configurations were recently performed using NASA engine and aircraft system analysis tools. The HWB aircraft were sized to an equivalent mission as the reference aircraft and assessments were performed using measurements of airframe shielding from a series of propulsion airframe aeroacoustic experiments. The focus of this work is to auralize flyover noise from the reference aircraft and the best HWB configuration using source noise predictions and shielding data based largely on the earlier assessments. For each aircraft, three flyover conditions are auralized. These correspond to approach, sideline, and cutback operating states, but flown in straight and level flight trajectories. The auralizations are performed using synthesis and simulation tools developed at NASA. Audio and visual presentations are provided to allow the reader to experience the flyover from the perspective of a listener in the simulated environment.

40 CFR 75.22 - Reference test methods.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Reference test methods. 75.22 Section...) CONTINUOUS EMISSION MONITORING Operation and Maintenance Requirements § 75.22 Reference test methods. (a) The owner or operator shall use the following methods, which are found in appendices A-1 through A-4 to part...

Optimized autonomous operations of a 20 K space hydrogen sorption cryocooler

NASA Astrophysics Data System (ADS)

Borders, J.; Morgante, G.; Prina, M.; Pearson, D.; Bhandari, P.

2004-06-01

A fully redundant hydrogen sorption cryocooler is being developed for the European Space Agency Planck mission, dedicated to the measurement of the temperature anisotropies of the cosmic microwave background radiation with unprecedented sensitivity and resolution [Advances in Cryogenic Engineering 45A (2000) 499]. In order to achieve this ambitious scientific task, this cooler is required to provide a stable temperature reference (˜20 K) and appropriate cooling (˜1 W) to the two instruments on-board, with a flight operational lifetime of 18 months. During mission operations, communication with the spacecraft will be possible in a restricted time-window, not longer than 2 h/day. This implies the need for an operations control structure with the required robustness to safely perform autonomous procedures. The cooler performance depends on many operating parameters (such as the temperatures of the pre-cooling stages and the warm radiator), therefore the operation control system needs the capability to adapt to variations of these boundary conditions, while maintaining safe operating procedures. An engineering bread board (EBB) cooler was assembled and tested to evaluate the behavior of the system under conditions simulating flight operations and the test data were used to refine and improve the operation control software. In order to minimize scientific data loss, the cooler is required to detect all possible failure modes and to autonomously react to them by taking the appropriate action in a rapid fashion. Various procedures and schemes both general and specific in nature were developed, tested and implemented to achieve these goals. In general, the robustness to malfunctions was increased by implementing an automatic classification of anomalies in different levels relative to the seriousness of the error. The response is therefore proportional to the failure level. Specifically, the start-up sequence duration was significantly reduced, allowing a much faster activation of the system, particularly useful in case of restarts after inadvertent shutdowns arising from malfunctions in the spacecraft. The capacity of the system to detect J-T plugs was increased to the point that the cooler is able to autonomously identify actual contaminants clogging from gas flow reductions due to off-nominal operating conditions. Once a plug is confirmed, the software autonomously energizes, and subsequently turns off, a J-T defrost heater until the clog is removed, bringing the system back to normal operating conditions. In this paper, all the cooler Operational Modes are presented, together with the description of the logic structure of the procedures and the advantages they produce for the operations.

Self-Test Procedures for Gas Sensors Embedded in Microreactor Systems.

PubMed

Helwig, Andreas; Hackner, Angelika; Müller, Gerhard; Zappa, Dario; Sberveglieri, Giorgio

2018-02-03

Metal oxide (MOX) gas sensors sensitively respond to a wide variety of combustible, explosive and poisonous gases. However, due to the lack of a built-in self-test capability, MOX gas sensors have not yet been able to penetrate safety-critical applications. In the present work we report on gas sensing experiments performed on MOX gas sensors embedded in ceramic micro-reaction chambers. With the help of an external micro-pump, such systems can be operated in a periodic manner alternating between flow and no-flow conditions, thus allowing repetitive measurements of the sensor resistances under clean air, R 0 , and under gas exposure, R g a s , to be obtained, even under field conditions. With these pairs of resistance values, eventual drifts in the sensor baseline resistance can be detected and drift-corrected values of the relative resistance response R e s p = ( R 0 - R g a s ) / R 0 can be determined. Residual poisoning-induced changes in the relative resistance response can be detected by reference to humidity measurements taken with room-temperature-operated capacitive humidity sensors which are insensitive to the poisoning processes operative on heated MOX gas sensors.

Modeling the emissions of a dual fuel engine coupled with a biomass gasifier-supplementing the Wiebe function.

PubMed

Vakalis, Stergios; Caligiuri, Carlo; Moustakas, Konstantinos; Malamis, Dimitris; Renzi, Massimiliano; Baratieri, Marco

2018-03-12

There is a growing market demand for small-scale biomass gasifiers that is driven by the economic incentives and the legislative framework. Small-scale gasifiers produce a gaseous fuel, commonly referred to as producer gas, with relatively low heating value. Thus, the most common energy conversion systems that are coupled with small-scale gasifiers are internal combustion engines. In order to increase the electrical efficiency, the operators choose dual fuel engines and mix the producer gas with diesel. The Wiebe function has been a valuable tool for assessing the efficiency of dual fuel internal combustion engines. This study introduces a thermodynamic model that works in parallel with the Wiebe function and calculates the emissions of the engines. This "vis-à-vis" approach takes into consideration the actual conditions inside the cylinders-as they are returned by the Wiebe function-and calculates the final thermodynamic equilibrium of the flue gases mixture. This approach aims to enhance the operation of the dual fuel internal combustion engines by identifying the optimal operating conditions and-at the same time-advance pollution control and minimize the environmental impact.

Comparison of Numerically Simulated and Experimentally Measured Performance of a Rotating Detonation Engine

NASA Technical Reports Server (NTRS)

Paxson, Daniel E.; Fotia, Matthew L.; Hoke, John; Schauer, Fred

2015-01-01

A quasi-two-dimensional, computational fluid dynamic (CFD) simulation of a rotating detonation engine (RDE) is described. The simulation operates in the detonation frame of reference and utilizes a relatively coarse grid such that only the essential primary flow field structure is captured. This construction and other simplifications yield rapidly converging, steady solutions. Viscous effects, and heat transfer effects are modeled using source terms. The effects of potential inlet flow reversals are modeled using boundary conditions. Results from the simulation are compared to measured data from an experimental RDE rig with a converging-diverging nozzle added. The comparison is favorable for the two operating points examined. The utility of the code as a performance optimization tool and a diagnostic tool are discussed.

Development of an autofluorescence spectral database for the identification and classification of microbial extremophiles

NASA Astrophysics Data System (ADS)

Davis, Justin; Howard, Hillari; Hoover, Richard B.; Sabanayagam, Chandran R.

2010-09-01

Extremophiles are microorganisms that have adapted to severe conditions that were once considered devoid of life. The extreme settings in which these organisms flourish on Earth resemble many extraterrestrial environments. Identification and classification of extremophiles in situ (without the requirement for excessive handling and processing) can provide a basis for designing remotely operated instruments for extraterrestrial life exploration. An important consideration when designing such experiments is to prevent contamination of the environments. We are developing a reference spectral database of autofluorescence from microbial extremophiles using long-UV excitation (408 nm). Aromatic compounds are essential components of living systems, and biological molecules such as aromatic amino acids, nucleotides, porphyrins and vitamins can also exhibit fluorescence under long-UV excitation conditions. Autofluorescence spectra were obtained from a light microscope that additionally allowed observations of microbial geometry and motility. It was observed that all extremophiles studied displayed an autofluorescence peak at around 470 nm, followed by a long decay that was species specific. The autofluorescence database can potentially be used as a reference to identify and classify past or present microbial life in our solar system.

Development of an Autofluorescence Spectral Database for the Identification and Classification of Microbial Extremophiles

NASA Technical Reports Server (NTRS)

Sabanayagam, Chandran; Howard, Hillari; Hoover, Richard B.

2010-01-01

Extremophiles are microorganisms that have adapted to severe conditions that were once considered devoid of life. The extreme settings in which these organisms flourish on earth resemble many extraterrestrial environments. Identification and classification of extremophiles in situ (without the requirement for excessive handling and processing) can provide a basis for designing remotely operated instruments for extraterrestrial life exploration. An important consideration when designing such experiments is to prevent contamination of the environments. We are developing a reference spectral database of autofluorescence from microbial extremophiles using long-UV excitation (405 nm). Aromatic compounds are essential components of living systems, and biological molecules such as aromatic amino acids, nucleotides, porphyrins and vitamins can also exhibit fluorescence under long-UV excitation conditions. Autofluorescence spectra were obtained from a confocal microscope that additionally allowed observations of microbial geometry and motility. It was observed that all extremophiles studied displayed an autofluorescence peak at around 470 nm, followed by a long decay that was species specific. The autofluorescence database can potentially be used as a reference to identify and classify past or present microbial life in our solar system.

Cupola Furnace Computer Process Model

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

Seymour Katz

2004-12-31

The cupola furnace generates more than 50% of the liquid iron used to produce the 9+ million tons of castings annually. The cupola converts iron and steel into cast iron. The main advantages of the cupola furnace are lower energy costs than those of competing furnaces (electric) and the ability to melt less expensive metallic scrap than the competing furnaces. However the chemical and physical processes that take place in the cupola furnace are highly complex making it difficult to operate the furnace in optimal fashion. The results are low energy efficiency and poor recovery of important and expensive alloymore » elements due to oxidation. Between 1990 and 2004 under the auspices of the Department of Energy, the American Foundry Society and General Motors Corp. a computer simulation of the cupola furnace was developed that accurately describes the complex behavior of the furnace. When provided with the furnace input conditions the model provides accurate values of the output conditions in a matter of seconds. It also provides key diagnostics. Using clues from the diagnostics a trained specialist can infer changes in the operation that will move the system toward higher efficiency. Repeating the process in an iterative fashion leads to near optimum operating conditions with just a few iterations. More advanced uses of the program have been examined. The program is currently being combined with an ''Expert System'' to permit optimization in real time. The program has been combined with ''neural network'' programs to affect very easy scanning of a wide range of furnace operation. Rudimentary efforts were successfully made to operate the furnace using a computer. References to these more advanced systems will be found in the ''Cupola Handbook''. Chapter 27, American Foundry Society, Des Plaines, IL (1999).« less

TIGO: a geodetic observatory for the improvement of the global reference frame

NASA Astrophysics Data System (ADS)

Schlueter, Wolfgang; Hase, Hayo; Boeer, Armin

1999-12-01

The Bundesamt fuer Kartographie und Geodaesie (BKG) will provide a major contribution to the improvement and maintenance of the global reference frames: ICRF (International Celestial Reference Frame), ITRF (International Terrestrial Reference Frame) with the operation of TIGO (Transportable Integrated Geodetic Observatory). TIGO is designed as a transportable geodetic observatory which consists of all relevant geodetic space techniques for a fundamental station (including VLBI, SLR, GPS). The transportability of the observatory enables to fill up gaps in the International Space Geodetic Network and to optimize the contribution to the global reference frames. TIGO should operate for a period of 2 to 3 years (at minimum) at one location. BKG is looking for a cooperation with countries willing to contribute to the ITRF and to support the operation of TIGO.

Using Stressor Gradients to Determine Reference Expectations for Great River Fish Assemblages

EPA Science Inventory

Determining reference conditions for large and great rivers like the Mississippi, Missouri, and Ohio Rivers is difficult because there are few, if any, reaches in minimally disturbed condition. In this paper, we describe a method for determining internal reference conditions usin...

A common body of care: the ethics and politics of teamwork in the operating theater are inseparable.

PubMed

Bleakley, Alan

2006-06-01

In the operating theater, the micro-politics of practice, such as interpersonal communications, are central to patient safety and are intimately tied with values as well as knowledge and skills. Team communication is a shared and distributed work activity. In an era of "professionalism," that must now encompass "interprofessionalism," a virtue ethics framework is often invoked to inform practice choices, with reference to phronesis or practical wisdom. However, such a framework is typically cast in individualistic terms as a character trait, rather than in terms of a distributed quality that may be constituted through intentionally collaborative practice, or is an emerging property of a complex, adaptive system. A virtue ethics approach is a necessary but not sufficient condition for a collaborative bioethics within the operating theater. There is also an ecological imperative-the patient's entry into the household (oikos) of the operating theater invokes the need for "hospitality" as a form of ethical practice.

Faithful Pointer for Qubit Measurement

NASA Astrophysics Data System (ADS)

Kumari, Asmita; Pan, A. K.

2018-02-01

In the context of von Neumann projective measurement scenario for a qubit system, it is widely believed that the mutual orthogonality between the post-interaction pointer states is the sufficient condition for achieving the ideal measurement situation. However, for experimentally verifying the observable probabilities, the real space distinction between the pointer distributions corresponding to post-interaction pointer states play crucial role. It is implicitly assumed that mutual orthogonality ensures the support between the post-interaction pointer distributions to be disjoint. We point out that mutual orthogonality (formal idealness) does not necessarily imply the real space distinguishability (operational idealness), but converse is true. In fact, for the commonly referred Gaussian wavefunction, it is possible to obtain a measurement situation which is formally ideal but fully nonideal operationally. In this paper, we derive a class of pointer states, that we call faithful pointers, for which the degree of formal (non)idealness is equal to the operational (non)idealness. In other words, for the faithful pointers, if a measurement situation is formally ideal then it is operationally ideal and vice versa.

Executive Resources and Item-Context Binding: Exploring the Influence of Concurrent Inhibition, Updating, and Shifting Tasks on Context Memory

PubMed Central

Nieznański, Marek; Obidziński, Michał; Zyskowska, Emilia; Niedziałkowska, Daria

2015-01-01

Previous research has demonstrated that context memory performance decreases as a result of cognitive load. However, the role of specific executive resources availability has not been specified yet. In a dual-task experiment, participants performed three kinds of concurrent task engaging: inhibition, updating, or shifting operations. In comparison with a no-load single-task condition, a significant decrease in item and context memory was observed, regardless of the kind of executive task. When executive load conditions were compared with non-specific cognitive load conditions, a significant interference effect was observed in the case of the inhibition task. The inhibition process appears to be an aspect of executive control, which relies on the same resource as item-context binding does, especially when binding refers to associations retrieved from long-term memory. PMID:26435761

A comparison of endoscopic localization error rate between operating surgeons and referring endoscopists in colorectal cancer.

PubMed

Azin, Arash; Saleh, Fady; Cleghorn, Michelle; Yuen, Andrew; Jackson, Timothy; Okrainec, Allan; Quereshy, Fayez A

2017-03-01

Colonoscopy for colorectal cancer (CRC) has a localization error rate as high as 21 %. Such errors can have substantial clinical consequences, particularly in laparoscopic surgery. The primary objective of this study was to compare accuracy of tumor localization at initial endoscopy performed by either the operating surgeon or non-operating referring endoscopist. All patients who underwent surgical resection for CRC at a large tertiary academic hospital between January 2006 and August 2014 were identified. The exposure of interest was the initial endoscopist: (1) surgeon who also performed the definitive operation (operating surgeon group); and (2) referring gastroenterologist or general surgeon (referring endoscopist group). The outcome measure was localization error, defined as a difference in at least one anatomic segment between initial endoscopy and final operative location. Multivariate logistic regression was used to explore the association between localization error rate and the initial endoscopist. A total of 557 patients were included in the study; 81 patients in the operating surgeon cohort and 476 patients in the referring endoscopist cohort. Initial diagnostic colonoscopy performed by the operating surgeon compared to referring endoscopist demonstrated statistically significant lower intraoperative localization error rate (1.2 vs. 9.0 %, P = 0.016); shorter mean time from endoscopy to surgery (52.3 vs. 76.4 days, P = 0.015); higher tattoo localization rate (32.1 vs. 21.0 %, P = 0.027); and lower preoperative repeat endoscopy rate (8.6 vs. 40.8 %, P < 0.001). Initial endoscopy performed by the operating surgeon was protective against localization error on both univariate analysis, OR 7.94 (95 % CI 1.08-58.52; P = 0.016), and multivariate analysis, OR 7.97 (95 % CI 1.07-59.38; P = 0.043). This study demonstrates that diagnostic colonoscopies performed by an operating surgeon are independently associated with a lower localization error rate. Further research exploring the factors influencing localization accuracy and why operating surgeons have lower error rates relative to non-operating endoscopists is necessary to understand differences in care.

Coke Deposition and Smoke Formation in Turbojet Engines

NASA Technical Reports Server (NTRS)

Hibbard, R. R.; Wear, J. D.

1956-01-01

In the early development of jet engines, it was occasionally found that excessive amounts of coke or other carbonaceous deposits were formed in the combustion chamber. Sometimes a considerable amount of smoke was noted in the-exhaust gases. Excessive coke deposits may adversely affect jet-engine performance in several ways. The formation of excessive amounts of coke on or just downstream of a fuel nozzle (figs. 116(a) and (b)) changes the fuel-spray pattern and possibly affects combustor life and performance. Similar effects on performance can result from the deposition of coke on primary-air entry ports (fig. 116(c)). Sea-level or altitude starting may be impaired by the deposition of coke on spark-plug electrodes (fig. 116(b)), deposits either grounding the electrodes completely or causing the spark to occur at positions other than the intended gap. For some time it was thought that large deposits of coke in turbojet combustion chambers (fig. 116(a)) might break away and damage turbine blades; however, experience has indicated that for metal blades this problem is insignificant. (Cermet turbine blades may be damaged by loose coke deposits.) Finally, the deposition of coke may cause high-temperature areas, which promote liner warping and cracking (fig. 116(d)) from excessive temperature gradients and variations in thermal-expansion rates. Smoke in the exhaust gases does not generally impair engine performance but may be undesirable from a tactical or a nuisance standpoint. Appendix B of reference 1 and references 2 to 4 present data obtained from full-scale engines operated on test stands and from flight tests that indicate some effects on performance caused by coke deposits and smoke. Some information about the mechanism of coke formation is given in reference 5 and chapter IX. The data indicate that (1) high-boiling fuel residuals and partly polymerized products may be mixed with a large amount of smoke formed in the gas phase to account for the consistency, structure, and chemical composition of the soft coke in the dome and (2) the hard deposits on the liner are similar to petroleum coke and may result from the liquid-phase thermal cracking of the fuel. During the early development period of jet engines, it was noted that the excessive coke deposits and exhaust smoke were generally obtained when fuel-oil-type fuels were used. Engines using gasoline-type fuels were relatively free from the deposits and smoke. These results indicated that some type of quality control would be needed in fuel specifications. Also noted was the effect of engine operating conditions on coke deposition. It is possible that, even with a clean-burning fuel, an excessive amount of coke could be formed at some operating conditions. In this case, combustor redesign could possibly reduce the coke to a tolerable level. This chapter is a summary of the various coke-deposition and exhaust-smoke problems connected- with the turbojet combustor. Included are (1) the effect of coke deposition on combustor life or durability and performance; (2) the effect of combustor design, operating conditions, inlet variables, and fuel characteristics on coke deposition; (3) elimination of coke deposits; (4) the effect of operating conditions and fuel characteristics on formation of exhaust smoke; and (5) various bench test methods proposed for determining and controlling fuel quality.

Modeling of gas-liquid mass transfer in a stirred tank bioreactor agitated by a Rushton turbine or a new pitched blade impeller.

PubMed

Gelves, Ricardo; Dietrich, A; Takors, Ralf

2014-03-01

A combined computational fluid dynamics (CFD) and population balance model (PBM) approach has been applied to simulate hydrodynamics and mass transfer in a 0.18 m(3) gas-liquid stirred bioreactor agitated by (1) a Rushton turbine, and (2) a new pitched blade geometry with rotating cartridges. The operating conditions chosen were motivated by typical settings used for culturing mammalian cells. The effects of turbulence, rotating flow, bubbles breakage and coalescence were simulated using the k-ε, multiple reference frame (MRF), Sliding mesh (SM) and PBM approaches, respectively. Considering the new pitched blade geometry with rotating aeration microspargers, [Formula: see text] mass transfer was estimated to be 34 times higher than the conventional Rushton turbine set-up. Notably, the impeller power consumption was modeled to be about 50 % lower. Independent [Formula: see text] measurements applying the same operational conditions confirmed this finding. Motivated by these simulated and experimental results, the new aeration and stirring device is qualified as a very promising tool especially useful for cell culture applications which are characterized by the challenging problem of achieving relatively high mass transfer conditions while inserting only low stirrer energy.

Assessment of correlations and models for the prediction of CHF in water subcooled flow boiling

NASA Astrophysics Data System (ADS)

Celata, G. P.; Cumo, M.; Mariani, A.

1994-01-01

The present paper provides an analysis of available correlations and models for the prediction of Critical Heat Flux (CHF) in subcooled flow boiling in the range of interest of fusion reactors thermal-hydraulic conditions, i.e. high inlet liquid subcooling and velocity and small channel diameter and length. The aim of the study was to establish the limits of validity of present predictive tools (most of them were proposed with reference to light water reactors (LWR) thermal-hydraulic studies) in the above conditions. The reference dataset represents almost all available data (1865 data points) covering wide ranges of operating conditions in the frame of present interest (0.1 less than p less than 8.4 MPa; 0.3 less than D less than 25.4 mm; 0.1 less than L less than 0.61 m; 2 less than G less than 90.0 Mg/sq m/s; 90 less than delta T(sub sub,in) less than 230 K). Among the tens of predictive tools available in literature four correlations (Levy, Westinghouse, modified-Tong and Tong-75) and three models (Weisman and Ileslamlou, Lee and Mudawar and Katto) were selected. The modified-Tong correlation and the Katto model seem to be reliable predictive tools for the calculation of the CHF in subcooled flow boiling.

49 CFR 385.321 - What failures of safety management practices disclosed by the safety audit will result in a...

Code of Federal Regulations, 2013 CFR

2013-10-01

... disqualified by a State, has lost the right to operate a CMV in a State or who is disqualified to operate a... violation refers to a driver operating a CMV as defined under § 383.5. 9. § 387.7(a)—Operating a motor... Single occurrence. This violation refers to a driver operating a CMV as defined under § 390.5. 13. § 395...

49 CFR 385.321 - What failures of safety management practices disclosed by the safety audit will result in a...

Code of Federal Regulations, 2012 CFR

2012-10-01

... disqualified by a State, has lost the right to operate a CMV in a State or who is disqualified to operate a... violation refers to a driver operating a CMV as defined under § 383.5. 9. § 387.7(a)—Operating a motor... Single occurrence. This violation refers to a driver operating a CMV as defined under § 390.5. 13. § 395...

49 CFR 385.321 - What failures of safety management practices disclosed by the safety audit will result in a...

Code of Federal Regulations, 2014 CFR

2014-10-01

... disqualified by a State, has lost the right to operate a CMV in a State or who is disqualified to operate a... violation refers to a driver operating a CMV as defined under § 383.5. 9. § 387.7(a)—Operating a motor... Single occurrence. This violation refers to a driver operating a CMV as defined under § 390.5. 13. § 395...

Cyclogiro windmill

DOEpatents

Brulle, R.V.

1981-09-03

A cyclogiro windmill has a rotor provided with blades shaped in the configuration of symmetrical airfoils and actuators to pivot the blades about axes parallel to the axis of rotation for the rotor. The actuator for each blade constantly changes the rock angle for the blade, that is its angle with respect to a reference on the rotor, and this modulation is such that the blade in making a revolution around the axis of rotation for the rotor undergoes an interval of static operation wherein its angle of attack is for the most part constant and less than the static stall angle, a short interval where the blade flips to position in which its opposite surface is presented toward the free wind, a short interval of dynamic operation wherein the angle of attack exceeds the static stal angle, another interval of static operation at an angle of attack of essentially the same magnitude as before, another interval of blade flip, and another interval of dynamic operation. During the intervals of dynamic operation, the blades experience a significant increase in lift force without a corresponding increase in drag, so that a high lift-to-drag ratio develops. The blades during dynamic operation further develop strong vortices which are directed outwardly at the sides of the windmill stream tube, and this increases the width of the stream tube, causing a greater mass of air to flow through the rotor. The short intervals of operation under dynamic conditions enable the blades to extract more energy from the free wind than would be possible if the blade operated solely under static conditions, and this in turn renders the windmill more useful in moderate velocity winds as well as high velocity winds.

Cyclogiro windmill

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

Brulle, R.V.

1981-09-03

A cyclogiro windmill has a rotor provided with blades shaped in the configuration of symmetrical airfoils and actuators to pivot the blades about axes parallel to the axis of rotation for the rotor. The actuator for each blade constantly changes the rock angle for the blade, that is its angle with respect to a reference on the rotor, and this modulation is such that the blade in making a revolution around the axis of rotation for the rotor undergoes an interval of static operation wherein its angle of attack is for the most part constant and less than the staticmore » stall angle, a short interval where the blade flips to position in which its opposite surface is presented toward the free wind, a short interval of dynamic operation wherein the angle of attack exceeds the static stal angle, another interval of static operation at an angle of attack of essentially the same magnitude as before, another interval of blade flip, and another interval of dynamic operation. During the intervals of dynamic operation, the blades experience a significant increase in lift force without a corresponding increase in drag, so that a high lift-to-drag ratio develops. The blades during dynamic operation further develop strong vortices which are directed outwardly at the sides of the windmill stream tube, and this increases the width of the stream tube, causing a greater mass of air to flow through the rotor. The short intervals of operation under dynamic conditions enable the blades to extract more energy from the free wind than would be possible if the blade operated solely under static conditions, and this in turn renders the windmill more useful in moderate velocity winds as well as high velocity winds.« less

An analytic-numerical method for the construction of the reference law of operation for a class of mechanical controlled systems

NASA Astrophysics Data System (ADS)

Mizhidon, A. D.; Mizhidon, K. A.

2017-04-01

An analytic-numerical method for the construction of a reference law of operation for a class of dynamic systems describing vibrations in controlled mechanical systems is proposed. By the reference law of operation of a system, we mean a law of the system motion that satisfies all the requirements for the quality and design features of the system under permanent external disturbances. As disturbances, we consider polyharmonic functions with known amplitudes and frequencies of the harmonics but unknown initial phases. For constructing the reference law of motion, an auxiliary optimal control problem is solved in which the cost function depends on a weighting coefficient. The choice of the weighting coefficient ensures the design of the reference law. Theoretical foundations of the proposed method are given.

Surveillance of Environmental and Procedural Measures of Infection Control in the Operating Theatre Setting

PubMed Central

Raggi, Alessandra; Sanna, Tiziana; Mazzetti, Magda; Orsi, Alessandra; Zanni, Angela; Farruggia, Patrizia

2017-01-01

The microbiological contamination of operating theatres and the lack of adherence to best practices by surgical staff represent some of the factors affecting Surgical Site Infections (SSIs). The aim of the present study was to assess the microbiological quality of operating settings and the staff compliance to the SSI evidence-based control measures. Ten operating rooms were examined for microbiological contamination of air and surfaces, after cleaning procedures, in “at rest” conditions. Furthermore, 10 surgical operations were monitored to assess staff compliance to the recommended practices. None of the air samples exceeded microbiological reference standards and only six of the 200 surface samples (3.0%) were slightly above recommended levels. Potentially pathogenic bacteria and moulds were never detected. Staff compliance to best practices varied depending on the type of behaviour investigated and the role of the operator. The major not compliant behaviours were: pre-operative skin antisepsis, crowding of the operating room and hand hygiene of the anaesthetist. The good environmental microbiological quality observed is indicative of the efficacy of the cleaning-sanitization procedures adopted. The major critical point was staff compliance to recommended practices. Awareness campaigns are therefore necessary, aimed at improving the organisation of work so as to facilitate compliance to operative protocols. PMID:29283367

Late diagnosis of a neglected cervical carcinoma in an elderly woman: a case report.

PubMed

Iavazzo, Christos; Efthimiou, Dorothy; Valavanis, Christos; Leontara, Joanna; Zarganis, Peter; Vorgias, George

2006-04-20

We report the case of an 88-year-old, Greek patient who was referred to our department with a bleeding mass that occupied her entire vagina. This exophytic tumor had extensive ulcerated areas and originated from the cervix. The biopsies taken from the mass confirmed it to be squamous cell carcinoma. Despite the giant size of the tumor, the parametria and middle and lower vagina were not infiltrated. Rather, the neglected mass created a severe septic condition that was progressing to disseminated intravascular coagulation DIC status. Because of the patient's advanced age and critical condition, we performed a "toilet" operation to remove the tumor mass. We subsequently administered radical radiation therapy with satisfactory results.

78 FR 76212 - Patient Protection and Affordable Care Act; Maximizing January 1, 2014 Coverage Opportunities

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-17

... referring to State Partnership Exchanges, which are a form of FFE. We use the term ``State-based SHOPs'' to refer to Small Business Health Options Programs (SHOPs) operated by a state and ``FF-SHOPs'' to refer to a SHOP operated by CMS. On March 27, 2012, we published a final rule entitled Patient Protection and...

Short-Term Frequency Response of a DFIG-Based Wind Turbine Generator for Rapid Frequency Stabilization

DOE PAGES

Yang, Dejian; Kang, Moses; Muljadi, Eduard; ...

2017-11-14

This paper proposes a short-term frequency-response scheme of a doubly-fed induction generator (DFIG)-based wind turbine generator (WTG) for improving rotor speed recovery and frequency nadir. In the energy-releasing period, to improve the frequency nadir and rotor speed convergence by releasing a large amount of kinetic energy stored in the rotating masses in a DFIG-based WTG, the power reference is increased up to the torque limit referred to the power and reduces along with it for a predefined period which is determined based on the occurrence time of the frequency nadir in a power grid. Then, the reference decreases so thatmore » the rotor speed is forced to be converged to the preset value in the stable operating region of the rotor speed. In the energy-absorbing period, to quickly recover the rotor speed, the reference smoothly decreases with the rotor speed and time during a predefined period until it intersects with the maximum power point tracking curve. The simulation results demonstrate that the proposed scheme successfully achieves rapid frequency stabilization with the improved frequency nadir under various wind conditions based on the IEEE 14-bus system.« less

Short-Term Frequency Response of a DFIG-Based Wind Turbine Generator for Rapid Frequency Stabilization

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

Yang, Dejian; Kang, Moses; Muljadi, Eduard

This paper proposes a short-term frequency-response scheme of a doubly-fed induction generator (DFIG)-based wind turbine generator (WTG) for improving rotor speed recovery and frequency nadir. In the energy-releasing period, to improve the frequency nadir and rotor speed convergence by releasing a large amount of kinetic energy stored in the rotating masses in a DFIG-based WTG, the power reference is increased up to the torque limit referred to the power and reduces along with it for a predefined period which is determined based on the occurrence time of the frequency nadir in a power grid. Then, the reference decreases so thatmore » the rotor speed is forced to be converged to the preset value in the stable operating region of the rotor speed. In the energy-absorbing period, to quickly recover the rotor speed, the reference smoothly decreases with the rotor speed and time during a predefined period until it intersects with the maximum power point tracking curve. The simulation results demonstrate that the proposed scheme successfully achieves rapid frequency stabilization with the improved frequency nadir under various wind conditions based on the IEEE 14-bus system.« less

Evaluation of home allergen sampling devices.

PubMed

Sercombe, J K; Liu-Brennan, D; Garcia, M L; Tovey, E R

2005-04-01

Simple, inexpensive methods of sampling from allergen reservoirs are necessary for large-scale studies or low-cost householder-operated allergen measurement. We tested two commercial devices: the Indoor Biotechnologies Mitest Dust Collector and the Drager Bio-Check Allergen Control; two devices of our own design: the Electrostatic Cloth Sampler (ECS) and the Press Tape Sampler (PTS); and a Vacuum Sampler as used in many allergen studies (our Reference Method). Devices were used to collect dust mite allergen samples from 16 domestic carpets. Results were examined for correlations between the sampling methods. With mite allergen concentration expressed as microg/g, the Mitest, the ECS and the PTS correlated with the Reference Method but not with each other. When mite allergen concentration was expressed as microg/m2 the Mitest and the ECS correlated with the Reference Method but the PTS did not. In the high allergen conditions of this study, the Drager Bio-Check did not relate to any methods. The Mitest Dust Collector, the ECS and the PTS show performance consistent with the Reference Method. Many techniques can be used to collect dust mite allergen samples. More investigation is needed to prove any method as superior for estimating allergen exposure.

Crop Field Reflectance Measurements

NASA Astrophysics Data System (ADS)

Weber, Christian; Schinca, Daniel C.; Tocho, Jorge O.; Videla, Fabian

2008-04-01

We present in this paper the results of reflectance measurements performed with a three-band passive radiometer with independent channels for solar irradiance reference. The comparative operation of the traditional method that alternatively uses measurements of the field (downward-looking) and a white panel for reference (downard-looking) and the new approach that involves duplicated spectral channels, each one with its own difuser that point upwards to the zenith direction (upward-looking) is analyzed. The results indicated that the latter method is more suitable for use with passive sensors under rapid changing atmospheric conditions (such as clouds, dust, mist, smog and other scatterers), since a more reliable synchronic record of reference and incident light is achieved. Besides, having separate channels for the reference and the signal allow a better balancing of gains in the amplifiers for each spectral channel. We show the results obtained in the determination of the Normalized Difference Vegetation Index (NDVI) corresponding to 2006 and 2007 field experiments concerning weeds detection and fertilizer levels assessing in wheat, to refine sensor-based fertilizer nitrogen rate recommendations. It is also shown the variation of the radiometric normalization measurements taken at noon (nadir solar position) for the whole culture cycle corresponding to two seasons (winter and spring).

A set-theoretic model reference adaptive control architecture for disturbance rejection and uncertainty suppression with strict performance guarantees

NASA Astrophysics Data System (ADS)

Arabi, Ehsan; Gruenwald, Benjamin C.; Yucelen, Tansel; Nguyen, Nhan T.

2018-05-01

Research in adaptive control algorithms for safety-critical applications is primarily motivated by the fact that these algorithms have the capability to suppress the effects of adverse conditions resulting from exogenous disturbances, imperfect dynamical system modelling, degraded modes of operation, and changes in system dynamics. Although government and industry agree on the potential of these algorithms in providing safety and reducing vehicle development costs, a major issue is the inability to achieve a-priori, user-defined performance guarantees with adaptive control algorithms. In this paper, a new model reference adaptive control architecture for uncertain dynamical systems is presented to address disturbance rejection and uncertainty suppression. The proposed framework is predicated on a set-theoretic adaptive controller construction using generalised restricted potential functions.The key feature of this framework allows the system error bound between the state of an uncertain dynamical system and the state of a reference model, which captures a desired closed-loop system performance, to be less than a-priori, user-defined worst-case performance bound, and hence, it has the capability to enforce strict performance guarantees. Examples are provided to demonstrate the efficacy of the proposed set-theoretic model reference adaptive control architecture.

INNOVATIVE TECHNOLOGY EVALUATION REPORT ...

EPA Pesticide Factsheets

The Split Core Sampler for Submerged Sediments (Split Core Sampler) designed and fabricated by Arts Manufacturing & Supply, Inc., was demonstrated under the U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation Program in April and May 1999 at sites in EPA Regions 1 and 5, respectively. In addition to assessing ease of sampler operation, key objectives of the demonstration included evaluating the samplers ability to (1) consistently collect a given volume of sediment, (2) consistently collect sediment in a given depth interval, (3) collect samples with consistent characteristics from a homogenous layer of sediment, and (4) collect samples under a variety of site conditions. This report describes the demonstration results for the Split Core Sampler and two conventional samplers (the Hand Corer and Vibrocorer) used as reference samplers. During the demonstration, the Split Core Sampler performed as well as or better than the reference samplers. Based on visual observations, both the Split Core Sampler and reference samplers collected partially compressed samples of consolidated and unconsolidated sediments from the sediment surface downward; sample representativeness may be questionable because of core shortening and core compression. Sediment stratification was preserved for both consolidated and unconsolidated sediment samples collected by the Split Core Sampler and reference samplers. No sampler was able to collect samples

NUTRITIONAL ASPECTS OF ANASTOMOTIC OPERATIONS—With Special Reference to the Sprue Syndrome

PubMed Central

Jones, Chester M.

1949-01-01

Necessary but radical operation which results in short-circuits between various levels of the digestive tract, with or without resections of portions of the esophagus, stomach or intestine, frequently cures the condition for which the operation was done, but leaves the patient with difficult nutritional problems. These nutritional disturbances are usually associated with inability to maintain or gain weight as a result of badly regulated movement of food material through the altered digestive tract, and by the removal or diversion of important digestive secretions, such as those elaborated by the stomach, pancreas, duodenum and small bowel. Increased intestinal rate and diminished specific gastrointestinal secretions reduce the ability of the small bowel to properly absorb food, with resulting malnutrition, deficiency disease, and at times specific avitaminosis. Inability to absorb fat and fat-soluble substances is a constant feature of these conditions. Successful treatment of the nutritional problems involves constant, prolonged overfeeding of nonbulky foods, usually given in regular, frequently administered meals of small volume. Vitamin concentrates may occasionally be of some temporary assistance but are not needed if a balanced diet is given and may cause undesirable and sometimes dangerous symptoms. The use of supplemental substances, such as liver extract and a wetting agent, such as “Tween 80,” to improve fat absorption have been demonstrated to be of value. The postoperative conditions described are fairly similar to the condition known as sprue, and it is possible that the general principles underlying the treatment of this disease apply to the entire group of post-operative nutritional disturbances alluded to. PMID:18143479

Performance of Thermal Mass Flow Meters in a Variable Gravitational Environment

NASA Technical Reports Server (NTRS)

Brooker, John E.; Ruff, Gary A.

2004-01-01

The performance of five thermal mass flow meters, MKS Instruments 179A and 258C, Unit Instruments UFM-8100, Sierra Instruments 830L, and Hastings Instruments HFM-200, were tested on the KC-135 Reduced Gravity Aircraft in orthogonal, coparallel, and counterparallel orientations relative to gravity. Data was taken throughout the parabolic trajectory where the g-level varied from 0.01 to 1.8 times normal gravity. Each meter was calibrated in normal gravity in the orthogonal position prior to flight followed by ground testing at seven different flow conditions to establish a baseline operation. During the tests, the actual flow rate was measured independently using choked-flow orifices. Gravitational acceleration and attitude had a unique effect on the performance of each meter. All meters operated within acceptable limits at all gravity levels in the calibrated orthogonal position. However, when operated in other orientations, the deviations from the reference flow became substantial for several of the flow meters. Data analysis indicated that the greatest source of error was the effect of orientation, followed by the gravity level. This work emphasized that when operating thermal flow meters in a variable gravity environment, it is critical to orient the meter in the same direction relative to gravity in which it was calibrated. Unfortunately, there was no test in normal gravity that could predict the performance of a meter in reduced gravity. When operating in reduced gravity, all meters indicated within 5 percent of the full scale reading at all flow conditions and orientations.

A novel model-based control strategy for aerobic filamentous fungal fed-batch fermentation processes.

PubMed

Mears, Lisa; Stocks, Stuart M; Albaek, Mads O; Cassells, Benny; Sin, Gürkan; Gernaey, Krist V

2017-07-01

A novel model-based control strategy has been developed for filamentous fungal fed-batch fermentation processes. The system of interest is a pilot scale (550 L) filamentous fungus process operating at Novozymes A/S. In such processes, it is desirable to maximize the total product achieved in a batch in a defined process time. In order to achieve this goal, it is important to maximize both the product concentration, and also the total final mass in the fed-batch system. To this end, we describe the development of a control strategy which aims to achieve maximum tank fill, while avoiding oxygen limited conditions. This requires a two stage approach: (i) calculation of the tank start fill; and (ii) on-line control in order to maximize fill subject to oxygen transfer limitations. First, a mechanistic model was applied off-line in order to determine the appropriate start fill for processes with four different sets of process operating conditions for the stirrer speed, headspace pressure, and aeration rate. The start fills were tested with eight pilot scale experiments using a reference process operation. An on-line control strategy was then developed, utilizing the mechanistic model which is recursively updated using on-line measurements. The model was applied in order to predict the current system states, including the biomass concentration, and to simulate the expected future trajectory of the system until a specified end time. In this way, the desired feed rate is updated along the progress of the batch taking into account the oxygen mass transfer conditions and the expected future trajectory of the mass. The final results show that the target fill was achieved to within 5% under the maximum fill when tested using eight pilot scale batches, and over filling was avoided. The results were reproducible, unlike the reference experiments which show over 10% variation in the final tank fill, and this also includes over filling. The variance of the final tank fill is reduced by over 74%, meaning that it is possible to target the final maximum fill reproducibly. The product concentration achieved at a given set of process conditions was unaffected by the control strategy. Biotechnol. Bioeng. 2017;114: 1459-1468. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Experimental studies on thermodynamic effects of developed cavitation

NASA Technical Reports Server (NTRS)

Ruggeri, R. S.

1974-01-01

A method for predicting thermodynamic effects of cavitation (changes in cavity pressure relative to stream vapor pressure) is presented. The prediction method accounts for changes in liquid, liquid temperature, flow velocity, and body scale. Both theoretical and experimental studies used in formulating the method are discussed. The prediction method provided good agreement between predicted and experimental results for geometrically scaled venturis handling four different liquids of widely diverse physical properties. Use of the method requires geometric similarity of the body and cavitated region and a known reference cavity-pressure depression at one operating condition.

Performance simulation for the design of solar heating and cooling systems

NASA Technical Reports Server (NTRS)

Mccormick, P. O.

1975-01-01

Suitable approaches for evaluating the performance and the cost of a solar heating and cooling system are considered, taking into account the value of a computer simulation concerning the entire system in connection with the large number of parameters involved. Operational relations concerning the collector efficiency in the case of a new improved collector and a reference collector are presented in a graph. Total costs for solar and conventional heating, ventilation, and air conditioning systems as a function of time are shown in another graph.

Frequency stabilization for mobile satellite terminals via LORAN

NASA Technical Reports Server (NTRS)

Ernst, Gregory J.; Kee, Steven M.; Marquart, Robert C.

1990-01-01

Digital satellite communication systems require careful management of frequency stability. Historically, frequency stability has been accomplished by continuously powered, high cost, high performance reference oscillators. Today's low cost mobile satellite communication equipment must operate under wide ranging environmental conditions, stabilize quickly after application of power, and provide adequate performance margin to overcome RF link impairments unique to the land mobile environment. Methods for frequency stabilization in land mobile applications must meet these objectives without incurring excessive performance degradation. A frequency stabilization scheme utilizing the LORAN (Long Range Navigation) system is presented.

Testbeds for Assessing Critical Scenarios in Power Control Systems

NASA Astrophysics Data System (ADS)

Dondossola, Giovanna; Deconinck, Geert; Garrone, Fabrizio; Beitollahi, Hakem

The paper presents a set of control system scenarios implemented in two testbeds developed in the context of the European Project CRUTIAL - CRitical UTility InfrastructurAL Resilience. The selected scenarios refer to power control systems encompassing information and communication security of SCADA systems for grid teleoperation, impact of attacks on inter-operator communications in power emergency conditions, impact of intentional faults on the secondary and tertiary control in power grids with distributed generators. Two testbeds have been developed for assessing the effect of the attacks and prototyping resilient architectures.

Experimental evaluation of a 600 lbf spacecraft rocket engine.

NASA Technical Reports Server (NTRS)

Hoehn, F. W.

1972-01-01

Experimental results are presented for a long-duration-capability (1000-sec), space-storable, bipropellant liquid rocket motor burning fluorine/hydrazine or FLOX/monomethylhydrazine. The interrelationship between injected mixture ratio and the per cent film cooling on vacuum specific impulse performance and chamber heat transfer is given. Experimental sea level measurements are used to predict space vacuum performance based upon simplified JANNAF reference procedures. Dynamic combustion stability is demonstrated over a wide range of operating conditions. Analytical results of char penetration, erosion, and ablative wall temperature distributions are presented for prototype chamber designs.

Unified implementation of the reference architecture : concept of operations.

DOT National Transportation Integrated Search

2015-10-19

This document describes the Concept of Operations (ConOps) for the Unified Implementation of the Reference Architecture, located in Southeast Michigan, which supports connected vehicle research and development. This ConOps describes the current state...

Voice and Valence-Altering Operations in Falam Chin: A Role and Reference Grammar Approach

ERIC Educational Resources Information Center

King, Deborah

2010-01-01

This dissertation describes and analyzes voice and valence-altering operations in Falam Chin, a Tibeto-Burman language of Burma. The data is explained within the framework of Role and Reference Grammar (RRG), which supplies several key concepts particularly useful for generalizing the behavior of the Falam Chin operations. The first is RRG's…

Probability of loss of assured safety in systems with multiple time-dependent failure modes.

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

Helton, Jon Craig; Pilch, Martin.; Sallaberry, Cedric Jean-Marie.

2012-09-01

Weak link (WL)/strong link (SL) systems are important parts of the overall operational design of high-consequence systems. In such designs, the SL system is very robust and is intended to permit operation of the entire system under, and only under, intended conditions. In contrast, the WL system is intended to fail in a predictable and irreversible manner under accident conditions and render the entire system inoperable before an accidental operation of the SL system. The likelihood that the WL system will fail to deactivate the entire system before the SL system fails (i.e., degrades into a configuration that could allowmore » an accidental operation of the entire system) is referred to as probability of loss of assured safety (PLOAS). Representations for PLOAS for situations in which both link physical properties and link failure properties are time-dependent are derived and numerically evaluated for a variety of WL/SL configurations, including PLOAS defined by (i) failure of all SLs before failure of any WL, (ii) failure of any SL before failure of any WL, (iii) failure of all SLs before failure of all WLs, and (iv) failure of any SL before failure of all WLs. The effects of aleatory uncertainty and epistemic uncertainty in the definition and numerical evaluation of PLOAS are considered.« less

Defining Chlorophyll-a Reference Conditions in European Lakes

PubMed Central

Alves, Maria Helena; Argillier, Christine; van den Berg, Marcel; Buzzi, Fabio; Hoehn, Eberhard; de Hoyos, Caridad; Karottki, Ivan; Laplace-Treyture, Christophe; Solheim, Anne Lyche; Ortiz-Casas, José; Ott, Ingmar; Phillips, Geoff; Pilke, Ansa; Pádua, João; Remec-Rekar, Spela; Riedmüller, Ursula; Schaumburg, Jochen; Serrano, Maria Luisa; Soszka, Hanna; Tierney, Deirdre; Urbanič, Gorazd; Wolfram, Georg

2010-01-01

The concept of “reference conditions” describes the benchmark against which current conditions are compared when assessing the status of water bodies. In this paper we focus on the establishment of reference conditions for European lakes according to a phytoplankton biomass indicator—the concentration of chlorophyll-a. A mostly spatial approach (selection of existing lakes with no or minor human impact) was used to set the reference conditions for chlorophyll-a values, supplemented by historical data, paleolimnological investigations and modelling. The work resulted in definition of reference conditions and the boundary between “high” and “good” status for 15 main lake types and five ecoregions of Europe: Alpine, Atlantic, Central/Baltic, Mediterranean, and Northern. Additionally, empirical models were developed for estimating site-specific reference chlorophyll-a concentrations from a set of potential predictor variables. The results were recently formulated into the EU legislation, marking the first attempt in international water policy to move from chemical quality standards to ecological quality targets. PMID:20401659

IODP Expedition 335: Deep Sampling in ODP Hole 1256D

NASA Astrophysics Data System (ADS)

Teagle, D. A. H.; Ildefonse, B.; Blum, P.; IODP Expedition 335 Scientists, the

2012-04-01

Observations of the gabbroic layers of untectonized ocean crust are essential to test theoretical models of the accretion of new crust at mid-ocean ridges. Integrated Ocean Drilling Program (IODP) Expedition 335 ("Superfast Spreading Rate Crust 4") returned to Ocean Drilling Program (ODP) Hole 1256D with the intention of deepening this reference penetration of intact ocean crust a significant distance (~350 m) into cumulate gabbros. Three earlier cruises to Hole 1256D (ODP 206, IODP 309/312) have drilled through the sediments, lavas, and dikes and 100 m into a complex dike-gabbro transition zone. Operations on IODP Expedition 335 proved challenging throughout, with almost three weeks spent re-opening and securing unstable sections of the hole. When coring commenced, the comprehensive destruction of the coring bit required further remedial operations to remove junk and huge volumes of accumulated drill cuttings. Hole-cleaning operations using junk baskets were successful, and they recovered large irregular samples that document a hitherto unseen sequence of evolving geological conditions and the intimate coupling between temporally and spatially intercalated intrusive, hydrothermal, contact-metamorphic, partial melting, and retrogressive processes. Hole 1256D is now clean of junk, and it has been thoroughly cleared of the drill cuttings that hampered operations during this and previous expeditions. At the end of Expedition 335, we briefly resumed coring before undertaking cementing operations to secure problematic intervals. To ensure the greatest scientific return from the huge efforts to stabilize this primary ocean lithosphere reference site, it would be prudent to resume the deepening of Hole 1256D in the nearest possible future while it is open to full depth. doi:10.2204/iodp.sd.13.04.2011

Encounter risk analysis of rainfall and reference crop evapotranspiration in the irrigation district

NASA Astrophysics Data System (ADS)

Zhang, Jinping; Lin, Xiaomin; Zhao, Yong; Hong, Yang

2017-09-01

Rainfall and reference crop evapotranspiration are random but mutually affected variables in the irrigation district, and their encounter situation can determine water shortage risks under the contexts of natural water supply and demand. However, in reality, the rainfall and reference crop evapotranspiration may have different marginal distributions and their relations are nonlinear. In this study, based on the annual rainfall and reference crop evapotranspiration data series from 1970 to 2013 in the Luhun irrigation district of China, the joint probability distribution of rainfall and reference crop evapotranspiration are developed with the Frank copula function. Using the joint probability distribution, the synchronous-asynchronous encounter risk, conditional joint probability, and conditional return period of different combinations of rainfall and reference crop evapotranspiration are analyzed. The results show that the copula-based joint probability distributions of rainfall and reference crop evapotranspiration are reasonable. The asynchronous encounter probability of rainfall and reference crop evapotranspiration is greater than their synchronous encounter probability, and the water shortage risk associated with meteorological drought (i.e. rainfall variability) is more prone to appear. Compared with other states, there are higher conditional joint probability and lower conditional return period in either low rainfall or high reference crop evapotranspiration. For a specifically high reference crop evapotranspiration with a certain frequency, the encounter risk of low rainfall and high reference crop evapotranspiration is increased with the decrease in frequency. For a specifically low rainfall with a certain frequency, the encounter risk of low rainfall and high reference crop evapotranspiration is decreased with the decrease in frequency. When either the high reference crop evapotranspiration exceeds a certain frequency or low rainfall does not exceed a certain frequency, the higher conditional joint probability and lower conditional return period of various combinations likely cause a water shortage, but the water shortage is not severe.

Drilling force and temperature of bone under dry and physiological drilling conditions

NASA Astrophysics Data System (ADS)

Xu, Linlin; Wang, Chengyong; Jiang, Min; He, Huiyu; Song, Yuexian; Chen, Hanyuan; Shen, Jingnan; Zhang, Jiayong

2014-11-01

Many researches on drilling force and temperature have been done with the aim to reduce the labour intensiveness of surgery, avoid unnecessary damage and improve drilling quality. However, there has not been a systematic study of mid- and high-speed drilling under dry and physiological conditions(injection of saline). Furthermore, there is no consensus on optimal drilling parameters. To study these parameters under dry and physiological drilling conditions, pig humerus bones are drilled with medical twist drills operated using a wide range of drilling speeds and feed rates. Drilling force and temperature are measured using a YDZ-II01W dynamometer and a NEC TVS-500EX thermal infrared imager, respectively, to evaluate internal bone damage. To evaluate drilling quality, bone debris and hole morphology are observed by SEM(scanning electron microscopy). Changes in drilling force and temperature give similar results during drilling such that the value of each parameter peaks just before the drill penetrates through the osteon of the compact bone into the trabeculae of the spongy bone. Drilling temperatures under physiological conditions are much lower than those observed under dry conditions, while a larger drilling force occurs under physiological conditions than dry conditions. Drilling speed and feed rate have a significant influence on drilling force, temperature, bone debris and hole morphology. The investigation of the effect of drilling force and temperature on internal bone damage reveals that a drilling speed of 4500 r/min and a feed rate of 50 mm/min are recommended for bone drilling under physiological conditions. Drilling quality peaks under these optimal parameter conditions. This paper proposes the optimal drilling parameters under mid- and high-speed surgical drilling, considering internal bone damage and drilling quality, which can be looked as a reference for surgeons performing orthopedic operations.

Precision displacement reference system

DOEpatents

Bieg, Lothar F.; Dubois, Robert R.; Strother, Jerry D.

2000-02-22

A precision displacement reference system is described, which enables real time accountability over the applied displacement feedback system to precision machine tools, positioning mechanisms, motion devices, and related operations. As independent measurements of tool location is taken by a displacement feedback system, a rotating reference disk compares feedback counts with performed motion. These measurements are compared to characterize and analyze real time mechanical and control performance during operation.

RANS computations for identification of 1-D cavitation model parameters: application to full load cavitation vortex rope

NASA Astrophysics Data System (ADS)

Alligné, S.; Decaix, J.; Müller, A.; Nicolet, C.; Avellan, F.; Münch, C.

2017-04-01

Due to the massive penetration of alternative renewable energies, hydropower is a key energy conversion technology for stabilizing the electrical power network by using hydraulic machines at off design operating conditions. At full load, the axisymmetric cavitation vortex rope developing in Francis turbines acts as an internal source of energy, leading to an instability commonly referred to as self-excited surge. 1-D models are developed to predict this phenomenon and to define the range of safe operating points for a hydropower plant. These models require a calibration of several parameters. The present work aims at identifying these parameters by using CFD results as objective functions for an optimization process. A 2-D Venturi and 3-D Francis turbine are considered.

Collecting cometary soil samples? Development of the ROSETTA sample acquisition system

NASA Technical Reports Server (NTRS)

Coste, P. A.; Fenzi, M.; Eiden, Michael

1993-01-01

In the reference scenario of the ROSETTA CNRS mission, the Sample Acquisition System is mounted on the Comet Lander. Its tasks are to acquire three kinds of cometary samples and to transfer them to the Earth Return Capsule. Operations are to be performed in vacuum and microgravity, on a probably rough and dusty surface, in a largely unknown material, at temperatures in the order of 100 K. The concept and operation of the Sample Acquisition System are presented. The design of the prototype corer and surface sampling tool, and of the equipment for testing them at cryogenic temperatures in ambient conditions and in vacuum in various materials representing cometary soil, are described. Results of recent preliminary tests performed in low temperature thermal vacuum in a cometary analog ice-dust mixture are provided.

Operator Variability in Scan Positioning is a Major Component of HR-pQCT Precision Error and is Reduced by Standardized Training

PubMed Central

Bonaretti, Serena; Vilayphiou, Nicolas; Chan, Caroline Mai; Yu, Andrew; Nishiyama, Kyle; Liu, Danmei; Boutroy, Stephanie; Ghasem-Zadeh, Ali; Boyd, Steven K.; Chapurlat, Roland; McKay, Heather; Shane, Elizabeth; Bouxsein, Mary L.; Black, Dennis M.; Majumdar, Sharmila; Orwoll, Eric S.; Lang, Thomas F.; Khosla, Sundeep; Burghardt, Andrew J.

2017-01-01

Introduction HR-pQCT is increasingly used to assess bone quality, fracture risk and anti-fracture interventions. The contribution of the operator has not been adequately accounted in measurement precision. Operators acquire a 2D projection (“scout view image”) and define the region to be scanned by positioning a “reference line” on a standard anatomical landmark. In this study, we (i) evaluated the contribution of positioning variability to in vivo measurement precision, (ii) measured intra- and inter-operator positioning variability, and (iii) tested if custom training software led to superior reproducibility in new operators compared to experienced operators. Methods To evaluate the operator in vivo measurement precision we compared precision errors calculated in 64 co-registered and non-co-registered scan-rescan images. To quantify operator variability, we developed software that simulates the positioning process of the scanner’s software. Eight experienced operators positioned reference lines on scout view images designed to test intra- and inter-operator reproducibility. Finally, we developed modules for training and evaluation of reference line positioning. We enrolled 6 new operators to participate in a common training, followed by the same reproducibility experiments performed by the experienced group. Results In vivo precision errors were up to three-fold greater (Tt.BMD and Ct.Th) when variability in scan positioning was included. Inter-operator precision errors were significantly greater than short-term intra-operator precision (p<0.001). New trained operators achieved comparable intra-operator reproducibility to experienced operators, and lower inter-operator reproducibility (p<0.001). Precision errors were significantly greater for the radius than for the tibia. Conclusion Operator reference line positioning contributes significantly to in vivo measurement precision and is significantly greater for multi-operator datasets. Inter-operator variability can be significantly reduced using a systematic training platform, now available online (http://webapps.radiology.ucsf.edu/refline/). PMID:27475931

Performance and durability of improved air-atomizing splash-cone fuel nozzles

NASA Technical Reports Server (NTRS)

Ingebo, R. D.; Norgren, C. T.

1974-01-01

An improved design of air-atomizing fuel nozzles was determined from a study of four differently shaped splash-cone fuel nozzles after 56 hr of durability testing in a combustor segment. Test conditions included fuel-air ratios of 0.008 to 0.018, inlet-air total pressures of 41 to 203 N/cm, inlet-air temperatures of 477 to 811 K, and a reference velocity of 21.3 m/sec. Flat-tip fuel nozzles showed the least erosion damage and at a combustor operating condition of 700 K and 101 N/sq cm an oxides-of-nitrogen emission index of 12 and a smoke number of approximately 18 with a fuel-air ratio of 0.018. Emission indices for carbon monoxide and unburned hydrocarbons were 44 and 16, respectively, at simulated idle conditions of 477 K and 41 N/sq cm.

Implementation of Portable Emissions Measurement Systems (PEMS) for the Real-driving Emissions (RDE) Regulation in Europe.

PubMed

Giechaskiel, Barouch; Vlachos, Theodoros; Riccobono, Francesco; Forni, Fausto; Colombo, Rinaldo; Montigny, Francois; Le-Lijour, Philippe; Carriero, Massimo; Bonnel, Pierre; Weiss, Martin

2016-12-04

Vehicles are tested in controlled and relatively narrow laboratory conditions to determine their official emission values and reference fuel consumption. However, on the road, ambient and driving conditions can vary over a wide range, sometimes causing emissions to be higher than those measured in the laboratory. For this reason, the European Commission has developed a complementary Real-Driving Emissions (RDE) test procedure using the Portable Emissions Measurement Systems (PEMS) to verify gaseous pollutant and particle number emissions during a wide range of normal operating conditions on the road. This paper presents the newly-adopted RDE test procedure, differentiating six steps: 1) vehicle selection, 2) vehicle preparation, 3) trip design, 4) trip execution, 5) trip verification, and 6) calculation of emissions. Of these steps, vehicle preparation and trip execution are described in greater detail. Examples of trip verification and the calculations of emissions are given.

Implementation of Portable Emissions Measurement Systems (PEMS) for the Real-driving Emissions (RDE) Regulation in Europe

PubMed Central

Giechaskiel, Barouch; Vlachos, Theodoros; Riccobono, Francesco; Forni, Fausto; Colombo, Rinaldo; Montigny, Francois; Le-Lijour, Philippe; Carriero, Massimo; Bonnel, Pierre; Weiss, Martin

2016-01-01

Vehicles are tested in controlled and relatively narrow laboratory conditions to determine their official emission values and reference fuel consumption. However, on the road, ambient and driving conditions can vary over a wide range, sometimes causing emissions to be higher than those measured in the laboratory. For this reason, the European Commission has developed a complementary Real-Driving Emissions (RDE) test procedure using the Portable Emissions Measurement Systems (PEMS) to verify gaseous pollutant and particle number emissions during a wide range of normal operating conditions on the road. This paper presents the newly-adopted RDE test procedure, differentiating six steps: 1) vehicle selection, 2) vehicle preparation, 3) trip design, 4) trip execution, 5) trip verification, and 6) calculation of emissions. Of these steps, vehicle preparation and trip execution are described in greater detail. Examples of trip verification and the calculations of emissions are given. PMID:28060306

Pressure-Drop Considerations in the Characterization of Dew-Point Transfer Standards at High Temperatures

NASA Astrophysics Data System (ADS)

Mitter, H.; Böse, N.; Benyon, R.; Vicente, T.

2012-09-01

During calibration of precision optical dew-point hygrometers (DPHs), it is usually necessary to take into account the pressure drop induced by the gas flow between the "point of reference" and the "point of use" (mirror or measuring head of the DPH) either as a correction of the reference dew-point temperature or as part of the uncertainty estimation. At dew-point temperatures in the range of ambient temperature and below, it is sufficient to determine the pressure drop for the required gas flow, and to keep the volumetric flow constant during the measurements. In this case, it is feasible to keep the dry-gas flow into the dew-point generator constant or to measure the flow downstream the DPH at ambient temperature. In normal operation, at least one DPH in addition to the monitoring DPH are used, and this operation has to be applied to each instrument. The situation is different at high dew-point temperatures up to 95 °C, the currently achievable upper limit reported in this paper. With increasing dew-point temperatures, the reference gas contains increasing amounts of water vapour and a constant dry-gas flow will lead to a significant enhanced volume flow at the conditions at the point of use, and therefore, to a significantly varying pressure drop depending on the applied dew-point temperature. At dew-point temperatures above ambient temperature, it is also necessary to heat the reference gas and the mirror head of the DPH sufficiently to avoid condensation which will additionally increase the volume flow and the pressure drop. In this paper, a method is provided to calculate the dry-gas flow rate needed to maintain a known wet-gas flow rate through a chilled mirror for a range of temperature and pressures.

An integrated monitoring approach using multiple reference sites to assess sustainable restoration in coastal Louisiana

Treesearch

Gregory D. Steyer; Robert R. Twilley; Richard C. Raynie

2006-01-01

Achieving sustainable resource management in coastal Louisiana requires establishing reference conditions that incorporate the goals and objectives of restoration efforts. Since the reference condition is usually considered sustainable, it can be a gauge to assess the present condition of a (degraded) system or to evaluate progress of management actions toward some...

Getting a Handle on Learning Anatomy with Interactive Three-Dimensional Graphics

ERIC Educational Resources Information Center

Stull, Andrew T.; Hegarty, Mary; Mayer, Richard E.

2009-01-01

In 2 experiments, participants learned bone anatomy by using a handheld controller to rotate an on-screen 3-dimensional bone model. The on-screen bone either included orientation references, which consisted of visible lines marking its axes (orientation reference condition), or did not include such references (no-orientation reference condition).…

Optimum Operating Conditions for PZT Actuators for Vibrotactile Wearables

NASA Astrophysics Data System (ADS)

Logothetis, Irini; Matsouka, Dimitra; Vassiliadis, Savvas; Vossou, Clio; Siores, Elias

2018-04-01

Recently, vibrotactile wearables have received much attention in fields such as medicine, psychology, athletics and video gaming. The electrical components presently used to generate vibration are rigid; hence, the design and creation of ergonomical wearables are limited. Significant advances in piezoelectric components have led to the production of flexible actuators such as piezoceramic lead zirconate titanate (PZT) film. To verify the functionality of PZT actuators for use in vibrotactile wearables, the factors influencing the electromechanical conversion were analysed and tested. This was achieved through theoretical and experimental analyses of a monomorph clamped-free structure for the PZT actuator. The research performed for this article is a three-step process. First, a theoretical analysis presents the equations governing the actuator. In addition, the eigenfrequency of the film was analysed preceding the experimental section. For this stage, by applying an electric voltage and varying the stimulating electrical characteristics (i.e., voltage, electrical waveform and frequency), the optimum operating conditions for a PZT film were determined. The tip displacement was measured referring to the mechanical energy converted from electrical energy. From the results obtained, an equation for the mechanical behaviour of PZT films as actuators was deduced. It was observed that the square waveform generated larger tip displacements. In conjunction with large voltage inputs at the predetermined eigenfrequency, the optimum operating conditions for the actuator were achieved. To conclude, PZT films can be adapted to assist designers in creating comfortable vibrotactile wearables.

Optimum Operating Conditions for PZT Actuators for Vibrotactile Wearables

NASA Astrophysics Data System (ADS)

Logothetis, Irini; Matsouka, Dimitra; Vassiliadis, Savvas; Vossou, Clio; Siores, Elias

2018-07-01

Recently, vibrotactile wearables have received much attention in fields such as medicine, psychology, athletics and video gaming. The electrical components presently used to generate vibration are rigid; hence, the design and creation of ergonomical wearables are limited. Significant advances in piezoelectric components have led to the production of flexible actuators such as piezoceramic lead zirconate titanate (PZT) film. To verify the functionality of PZT actuators for use in vibrotactile wearables, the factors influencing the electromechanical conversion were analysed and tested. This was achieved through theoretical and experimental analyses of a monomorph clamped-free structure for the PZT actuator. The research performed for this article is a three-step process. First, a theoretical analysis presents the equations governing the actuator. In addition, the eigenfrequency of the film was analysed preceding the experimental section. For this stage, by applying an electric voltage and varying the stimulating electrical characteristics (i.e., voltage, electrical waveform and frequency), the optimum operating conditions for a PZT film were determined. The tip displacement was measured referring to the mechanical energy converted from electrical energy. From the results obtained, an equation for the mechanical behaviour of PZT films as actuators was deduced. It was observed that the square waveform generated larger tip displacements. In conjunction with large voltage inputs at the predetermined eigenfrequency, the optimum operating conditions for the actuator were achieved. To conclude, PZT films can be adapted to assist designers in creating comfortable vibrotactile wearables.

Thermal imager sources of non-uniformities: modeling of static and dynamic contributions during operations

NASA Astrophysics Data System (ADS)

Sozzi, B.; Olivieri, M.; Mariani, P.; Giunti, C.; Zatti, S.; Porta, A.

2014-05-01

Due to the fast-growing of cooled detector sensitivity in the last years, on the image 10-20 mK temperature difference between adjacent objects can theoretically be discerned if the calibration algorithm (NUC) is capable to take into account and compensate every spatial noise source. To predict how the NUC algorithm is strong in all working condition, the modeling of the flux impinging on the detector becomes a challenge to control and improve the quality of a properly calibrated image in all scene/ambient conditions including every source of spurious signal. In literature there are just available papers dealing with NU caused by pixel-to-pixel differences of detector parameters and by the difference between the reflection of the detector cold part and the housing at the operative temperature. These models don't explain the effects on the NUC results due to vignetting, dynamic sources out and inside the FOV, reflected contributions from hot spots inside the housing (for example thermal reference far of the optical path). We propose a mathematical model in which: 1) detector and system (opto-mechanical configuration and scene) are considered separated and represented by two independent transfer functions 2) on every pixel of the array the amount of photonic signal coming from different spurious sources are considered to evaluate the effect on residual spatial noise due to dynamic operative conditions. This article also contains simulation results showing how this model can be used to predict the amount of spatial noise.

Type-2 fuzzy logic control based MRAS speed estimator for speed sensorless direct torque and flux control of an induction motor drive.

PubMed

Ramesh, Tejavathu; Kumar Panda, Anup; Shiva Kumar, S

2015-07-01

In this research study, a model reference adaptive system (MRAS) speed estimator for speed sensorless direct torque and flux control (DTFC) of an induction motor drive (IMD) using two adaptation mechanism schemes are proposed to replace the conventional proportional integral controller (PIC). The first adaptation mechanism scheme is based on Type-1 fuzzy logic controller (T1FLC), which is used to achieve high performance sensorless drive in both transient as well as steady state conditions. However, the Type-1 fuzzy sets are certain and unable to work effectively when higher degree of uncertainties presents in the system which can be caused by sudden change in speed or different load disturbances, process noise etc. Therefore, a new Type-2 fuzzy logic controller (T2FLC) based adaptation mechanism scheme is proposed to better handle the higher degree of uncertainties and improves the performance and also robust to various load torque and sudden change in speed conditions, respectively. The detailed performances of various adaptation mechanism schemes are carried out in a MATLAB/Simulink environment with a speed sensor and speed sensorless modes of operation when an IMD is operating under different operating conditions, such as, no-load, load and sudden change in speed, respectively. To validate the different control approaches, the system also implemented on real-time system and adequate results are reported for its validation. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

National Airspace System Delay Estimation Using Weather Weighted Traffic Counts

NASA Technical Reports Server (NTRS)

Chatterji, Gano B.; Sridhar, Banavar

2004-01-01

Assessment of National Airspace System performance, which is usually measured in terms of delays resulting from the application of traffic flow management initiatives in response to weather conditions, volume, equipment outages and runway conditions, is needed both for guiding flow control decisions during the day of operations and for post operations analysis. Comparison of the actual delay, resulting from the traffic flow management initiatives, with the expected delay, based on traffic demand and other conditions, provides the assessment of the National Airspace System performance. This paper provides a method for estimating delay using the expected traffic demand and weather. In order to identify the cause of delays, 517 days of National Airspace System delay data reported by the Federal Aviation Administration s Operations Network were analyzed. This analysis shows that weather is the most important causal factor for delays followed by equipment and runway delays. Guided by these results, the concept of weather weighted traffic counts as a measure of system delay is described. Examples are given to show the variation of these counts as a function of time of the day. The various datasets, consisting of aircraft position data, enroute severe weather data, surface wind speed and visibility data, reported delay data and number of aircraft handled by the Centers data, and their sources are described. The procedure for selecting reference days on which traffic was minimally impacted by weather is described. Different traffic demand on each reference day of the week, determined by analysis of 42 days of traffic and delay data, was used as the expected traffic demand for each day of the week. Next, the method for computing the weather weighted traffic counts using the expected traffic demand, derived from reference days, and the expanded regions around severe weather cells is discussed. It is shown via a numerical example that this approach improves the dynamic range of the weather weighted traffic counts considerably. Time histories of these new weather weighted traffic counts are used for synthesizing two statistical features, six histogram features and six time domain features. In addition to these enroute weather features, two surface weather features of number of major airports in the United States with high mean winds and low mean visibility are also described. A least squares procedure for establishing a functional relation between the features, using combinations of these features, and system delays is explored using 36 days of data. Best correlations between the estimated delays using the functional relation and the actual delays provided by the Operations Network are obtained with two different combinations of features: 1) six time domain features of weather weighted traffic counts plus two surface weather features, and 2) six histogram features and mean of weather weighted traffic counts along with the two surface weather features. Correlation coefficient values of 0.73 and 0.83 were found in these two instances.

Application of permanents of square matrices for DNA identification in multiple-fatality cases

PubMed Central

2013-01-01

Background DNA profiling is essential for individual identification. In forensic medicine, the likelihood ratio (LR) is commonly used to identify individuals. The LR is calculated by comparing two hypotheses for the sample DNA: that the sample DNA is identical or related to a reference DNA, and that it is randomly sampled from a population. For multiple-fatality cases, however, identification should be considered as an assignment problem, and a particular sample and reference pair should therefore be compared with other possibilities conditional on the entire dataset. Results We developed a new method to compute the probability via permanents of square matrices of nonnegative entries. As the exact permanent is known as a #P-complete problem, we applied the Huber–Law algorithm to approximate the permanents. We performed a computer simulation to evaluate the performance of our method via receiver operating characteristic curve analysis compared with LR under the assumption of a closed incident. Differences between the two methods were well demonstrated when references provided neither obligate alleles nor impossible alleles. The new method exhibited higher sensitivity (0.188 vs. 0.055) at a threshold value of 0.999, at which specificity was 1, and it exhibited higher area under a receiver operating characteristic curve (0.990 vs. 0.959, P = 9.6E-15). Conclusions Our method therefore offers a solution for a computationally intensive assignment problem and may be a viable alternative to LR-based identification for closed-incident multiple-fatality cases. PMID:23962363

Defining And Employing Reference Conditions For Ecological Restoration Of The Lower Missouri River, USA

NASA Astrophysics Data System (ADS)

Jacobson, R. B.; Elliott, C. M.; Reuter, J. M.

2008-12-01

Ecological reference conditions are especially challenging for large, intensively managed rivers like the Lower Missouri. Historical information provides broad understanding of how the river has changed, but translating historical information into quantitative reference conditions remains a challenge. Historical information is less available for biological and chemical conditions than for physical conditions. For physical conditions, much of the early historical condition is documented in date-specific measurements or maps, and it is difficult to determine how representative these conditions are for a river system that was characterized historically by large floods and high channel migration rates. As an alternative to a historically defined least- disturbed condition, spatial variation within the Missouri River basin provides potential for defining a best- attainable reference condition. A possibility for the best-attainable condition for channel morphology is an unchannelized segment downstream of the lowermost dam (rkm 1298 - 1203). This segment retains multiple channels and abundant sandbars although it has a highly altered flow regime and a greatly diminished sediment supply. Conversely, downstream river segments have more natural flow regimes, but have been narrowed and simplified for navigation and bank stability. We use two computational tools to compensate for the lack of ideal reference conditions. The first is a hydrologic model that synthesizes natural and altered flow regimes based on 100 years of daily inputs to the river (daily routing model, DRM, US Army Corps of Engineers, 1998); the second tool is hydrodynamic modeling of habitat availability. The flow-regime and hydrodynamic outputs are integrated to define habitat-duration curves as the basis for reference conditions (least-disturbed flow regime and least-disturbed channel morphology). Lacking robust biological response models, we use mean residence time of water and a habitat diversity index as generic ecosystem indicators.

Validation of reference genes for RT-qPCR studies of gene expression in banana fruit under different experimental conditions.

PubMed

Chen, Lei; Zhong, Hai-ying; Kuang, Jian-fei; Li, Jian-guo; Lu, Wang-jin; Chen, Jian-ye

2011-08-01

Reverse transcription quantitative real-time PCR (RT-qPCR) is a sensitive technique for quantifying gene expression, but its success depends on the stability of the reference gene(s) used for data normalization. Only a few studies on validation of reference genes have been conducted in fruit trees and none in banana yet. In the present work, 20 candidate reference genes were selected, and their expression stability in 144 banana samples were evaluated and analyzed using two algorithms, geNorm and NormFinder. The samples consisted of eight sample sets collected under different experimental conditions, including various tissues, developmental stages, postharvest ripening, stresses (chilling, high temperature, and pathogen), and hormone treatments. Our results showed that different suitable reference gene(s) or combination of reference genes for normalization should be selected depending on the experimental conditions. The RPS2 and UBQ2 genes were validated as the most suitable reference genes across all tested samples. More importantly, our data further showed that the widely used reference genes, ACT and GAPDH, were not the most suitable reference genes in many banana sample sets. In addition, the expression of MaEBF1, a gene of interest that plays an important role in regulating fruit ripening, under different experimental conditions was used to further confirm the validated reference genes. Taken together, our results provide guidelines for reference gene(s) selection under different experimental conditions and a foundation for more accurate and widespread use of RT-qPCR in banana.

The Global Geodetic Observing System: Space Geodesy Networks for the Future

NASA Technical Reports Server (NTRS)

Pearlman, Michael; Pavlis, Erricos; Ma, Chopo; Altamini, Zuheir; Noll, Carey; Stowers, David

2011-01-01

Ground-based networks of co-located space geodetic techniques (VLBI, SLR, GNSS. and DORIS) are the basis for the development and maintenance of the International Terrestrial Reference frame (ITRF), which is our metric of reference for measurements of global change, The Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG) has established a task to develop a strategy to design, integrate and maintain the fundamental geodetic network and supporting infrastructure in a sustainable way to satisfy the long-term requirements for the reference frame. The GGOS goal is an origin definition at 1 mm or better and a temporal stability on the order of 0.1 mm/y, with similar numbers for the scale and orientation components. These goals are based on scientific requirements to address sea level rise with confidence, but other applications are not far behind. Recent studies including one by the US National Research Council has strongly stated the need and the urgency for the fundamental space geodesy network. Simulations are underway to examining accuracies for origin, scale and orientation of the resulting ITRF based on various network designs and system performance to determine the optimal global network to achieve this goal. To date these simulations indicate that 24 - 32 co-located stations are adequate to define the reference frame and a more dense GNSS and DORIS network will be required to distribute the reference frame to users anywhere on Earth. Stations in the new global network will require geologically stable sites with good weather, established infrastructure, and local support and personnel. GGOS wil seek groups that are interested in participation. GGOS intends to issues a Call for Participation of groups that would like to contribute in the network implementation and operation. Some examples of integrated stations currently in operation or under development will be presented. We will examine necessary conditions and challenges in designing a co-location station.

The Pavlovian analysis of instrumental conditioning.

PubMed

Gormezano, I; Tait, R W

1976-01-01

An account was given of the development within the Russian literature of a uniprocess formulation of classical and instrumental conditioning, known as the bidirectional conditioning hypothesis. The hypothesis purports to offer a single set of Pavlovian principles to account for both paradigms, based upon a neural model which assumes that bidirectional (forward and backward) connections are formed in both calssical and instrumental conditioning situations. In instrumental conditioning, the bidirectional connections are hypothesized to be simply more complex than those in classical conditioning, and any differences in empirical functions are presumed to lie not in difference in mechanism, but in the strength of the forward and backward connections. Although bidirectional connections are assumed to develop in instrumental conditioning, the experimental investigation of the bidirectional conditioning hypothesis has been essentially restricted to the classical conditioning operations of pairing two CSs (sensory preconditioning training), a US followed by a CS (backward conditioning training) and two USs. However, the paradigm involving the pairing of two USs, because of theoretical and analytical considerations, is the one most commonly employed by Russian investigators. The results of an initial experiment involving the pairing of two USs, and reference to the results of a more extensive investigation, leads us to tentatively question the validity of the bidirectional conditioning account of instrumental conditioning.

Thermal storage HVAC system retrofit provides economical air conditioning

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

Smith, S.F.

1993-03-01

This article describes an EMS-controlled HVAC system that meets the ventilation and cooling needs of an 18,000-seat indoor ice hockey arena. The Buffalo Memorial Auditorium (affectionately referred to as the Aud) was built in 1937 under the Works Project Administration of the federal government. Its original configuration included a 12,000-seat arena with an ice skating rink. By the late 1980s, the city was unsuccessfully attempting to attract events and tenants to the auditorium, which lacked air conditioning and other modern amenities. Thus, it was decided to renovate the facility to make it marketable. The first phase of the renovation includedmore » installing an air-conditioning system in the arena and repairing the existing building systems that were inoperable because of deferred maintenance. After considering the existing conditions (such as size of the space, intermittent usage, construction restrictions, operating budgets and the limited operations staff), the engineering team designed an innovative HVAC system. The system's features include: a carbon dioxide monitoring device that controls the intake of outside air; an ice storage system that provides chilled water and shifts electrical demand to off-peak hours; and a design that uses the building mass as a heat sink. A new energy management system (EMS) determines building cooling needs based on the type of event, ambient conditions and projected audience size. Then, it selects the most economical method to obtain the desired arena temperature.« less

Numerically constructed internal-coordinate Hamiltonian with Eckart embedding and its application for the inversion tunneling of ammonia.

PubMed

Fábri, Csaba; Mátyus, Edit; Császár, Attila G

2014-02-05

It is shown that the use of an Eckart-frame embedding with a kinetic energy operator expressed in curvilinear internal coordinates becomes feasible and straightforward to implement for arbitrary molecular compositions and internal coordinates if the operator is defined numerically over a (discrete variable representation) grid. The algorithm proposed utilizes the transformation method of Dymarsky and Kudin to maintain the rotational Eckart condition. In order to demonstrate the applicability and flexibility of our approach the non-rigid ammonia molecule is considered and the corresponding rotational-vibrational energy levels and wave functions are computed using kinetic energy operators with three different embeddings. Two of them fulfill the Eckart conditions corresponding to a trigonal pyramidal (C3v) and a trigonal planar (D3h) reference structure and the third one is a non-Eckart frame. The computed energy levels are, of course, identical, and the structure of the three different wave-function representations are analyzed in terms of the rigid rotor functions for a symmetric top. The possible advantages of one frame representation over another are discussed concerning the interpretation of the rovibrational states in terms of the traditional rigid rotor labels. Copyright © 2013 Elsevier B.V. All rights reserved.

Lean Blow-out Studies in a Swirl Stabilized Annular Gas Turbine Combustor

NASA Astrophysics Data System (ADS)

Mishra, R. K.; Kishore Kumar, S.; Chandel, Sunil

2015-05-01

Lean blow out characteristics in a swirl stabilized aero gas turbine combustor have been studied using computational fluid dynamics. For CFD analysis, a 22.5° sector of an annular combustor is modeled using unstructured tetrahedral meshes comprising 1.2 × 106 elements. The governing equations are solved using the eddy dissipation combustion model in CFX. The primary combustion zone is analyzed by considering it as a well stirred reactor. The analysis has been carried out for different operating conditions of the reactants entering into the control volume. The results are treated as the base-line or reference values. Combustion lean blow-out limits are further characterized studying the behavior of combustion zone during transient engine operation. The validity of the computational study has been established by experimental study on a full-scale annular combustor in an air flow test facility that is capable of simulating different conditions at combustor inlet. The experimental result is in a good agreement with the analytical predictions. Upon increasing the combustor mass flow, the lean blow out limit increases, i.e., the blow out occurs at higher fuel-air ratios. In addition, when the operating pressure decreases, the lean blow out limit increases, i.e., blow out occurs at higher fuel-air ratios.

Optimal Parameter Design of Coarse Alignment for Fiber Optic Gyro Inertial Navigation System.

PubMed

Lu, Baofeng; Wang, Qiuying; Yu, Chunmei; Gao, Wei

2015-06-25

Two different coarse alignment algorithms for Fiber Optic Gyro (FOG) Inertial Navigation System (INS) based on inertial reference frame are discussed in this paper. Both of them are based on gravity vector integration, therefore, the performance of these algorithms is determined by integration time. In previous works, integration time is selected by experience. In order to give a criterion for the selection process, and make the selection of the integration time more accurate, optimal parameter design of these algorithms for FOG INS is performed in this paper. The design process is accomplished based on the analysis of the error characteristics of these two coarse alignment algorithms. Moreover, this analysis and optimal parameter design allow us to make an adequate selection of the most accurate algorithm for FOG INS according to the actual operational conditions. The analysis and simulation results show that the parameter provided by this work is the optimal value, and indicate that in different operational conditions, the coarse alignment algorithms adopted for FOG INS are different in order to achieve better performance. Lastly, the experiment results validate the effectiveness of the proposed algorithm.

Electrochemical Selective and Simultaneous Detection of Diclofenac and Ibuprofen in Aqueous Solution Using HKUST-1 Metal-Organic Framework-Carbon Nanofiber Composite Electrode.

PubMed

Motoc, Sorina; Manea, Florica; Iacob, Adriana; Martinez-Joaristi, Alberto; Gascon, Jorge; Pop, Aniela; Schoonman, Joop

2016-10-17

In this study, the detection protocols for the individual, selective, and simultaneous determination of ibuprofen (IBP) and diclofenac (DCF) in aqueous solutions have been developed using HKUST-1 metal-organic framework-carbon nanofiber composite (HKUST-CNF) electrode. The morphological and electrical characterization of modified composite electrode prepared by film casting was studied by scanning electronic microscopy and four-point-probe methods. The electrochemical characterization of the electrode by cyclic voltammetry (CV) was considered the reference basis for the optimization of the operating conditions for chronoamperometry (CA) and multiple-pulsed amperometry (MPA). This electrode exhibited the possibility to selectively detect IBP and DCF by simple switching the detection potential using CA. However, the MPA operated under optimum working conditions of four potential levels selected based on CV shape in relation to the potential value, pulse time, and potential level number, and order allowed the selective/simultaneous detection of IBP and DCF characterized by the enhanced detection performance. For this application, the HKUST-CNF electrode exhibited a good stability and reproducibility of the results was achieved.

Electrochemical Selective and Simultaneous Detection of Diclofenac and Ibuprofen in Aqueous Solution Using HKUST-1 Metal-Organic Framework-Carbon Nanofiber Composite Electrode

PubMed Central

Motoc, Sorina; Manea, Florica; Iacob, Adriana; Martinez-Joaristi, Alberto; Gascon, Jorge; Pop, Aniela; Schoonman, Joop

2016-01-01

In this study, the detection protocols for the individual, selective, and simultaneous determination of ibuprofen (IBP) and diclofenac (DCF) in aqueous solutions have been developed using HKUST-1 metal-organic framework-carbon nanofiber composite (HKUST-CNF) electrode. The morphological and electrical characterization of modified composite electrode prepared by film casting was studied by scanning electronic microscopy and four-point-probe methods. The electrochemical characterization of the electrode by cyclic voltammetry (CV) was considered the reference basis for the optimization of the operating conditions for chronoamperometry (CA) and multiple-pulsed amperometry (MPA). This electrode exhibited the possibility to selectively detect IBP and DCF by simple switching the detection potential using CA. However, the MPA operated under optimum working conditions of four potential levels selected based on CV shape in relation to the potential value, pulse time, and potential level number, and order allowed the selective/simultaneous detection of IBP and DCF characterized by the enhanced detection performance. For this application, the HKUST-CNF electrode exhibited a good stability and reproducibility of the results was achieved. PMID:27763509

Energy Performance and Optimal Control of Air-conditioned Buildings Integrated with Phase Change Materials

NASA Astrophysics Data System (ADS)

Zhu, Na

This thesis presents an overview of the previous research work on dynamic characteristics and energy performance of buildings due to the integration of PCMs. The research work on dynamic characteristics and energy performance of buildings using PCMs both with and without air-conditioning is reviewed. Since the particular interest in using PCMs for free cooling and peak load shifting, specific research efforts on both subjects are reviewed separately. A simplified physical dynamic model of building structures integrated with SSPCM (shaped-stabilized phase change material) is developed and validated in this study. The simplified physical model represents the wall by 3 resistances and 2 capacitances and the PCM layer by 4 resistances and 2 capacitances respectively while the key issue is the parameter identification of the model. This thesis also presents the studies on the thermodynamic characteristics of buildings enhanced by PCM and on the investigation of the impacts of PCM on the building cooling load and peak cooling demand at different climates and seasons as well as the optimal operation and control strategies to reduce the energy consumption and energy cost by reducing the air-conditioning energy consumption and peak load. An office building floor with typical variable air volume (VAV) air-conditioning system is used and simulated as the reference building in the comparison study. The envelopes of the studied building are further enhanced by integrating the PCM layers. The building system is tested in two selected cities of typical climates in China including Hong Kong and Beijing. The cold charge and discharge processes, the operation and control strategies of night ventilation and the air temperature set-point reset strategy for minimizing the energy consumption and electricity cost are studied. This thesis presents the simulation test platform, the test results on the cold storage and discharge processes, the air-conditioning energy consumption and demand reduction potentials in typical air-conditioning seasons in typical China cites as well as the impacts of operation and control strategies.

30 CFR 203.54 - How does my relief arrangement for an oil and gas lease operate if prices rise sharply?

Code of Federal Regulations, 2010 CFR

2010-07-01

... gas lease operate if prices rise sharply? 203.54 Section 203.54 Mineral Resources MINERALS MANAGEMENT... arrangement for an oil and gas lease operate if prices rise sharply? In those months when your current reference price rises by at least 25 percent above your base reference price, you must pay the effective...

Special Operations Forces Reference Manual. Fourth Edition

DTIC Science & Technology

2015-06-01

Special Operations Forces Reference Manual Fourth Edition The JSOU Press MacDill AFB, Florida June 2015 Prepared by Joint Special Operations...other national and international security decision-makers, both military and civilian, through teaching, outreach, and research in the science and art...Luke First Edition, June 2005 (Revised July 2006) Second Edition, August 2008 Third Edition, September 2011 Fourth Edition, June 2015 This work was

Effects of dynamic operating conditions on nitrification in biological rapid sand filters for drinking water treatment.

PubMed

Lee, Carson O; Boe-Hansen, Rasmus; Musovic, Sanin; Smets, Barth; Albrechtsen, Hans-Jørgen; Binning, Philip

2014-11-01

Biological rapid sand filters are often used to remove ammonium from groundwater for drinking water supply. They often operate under dynamic substrate and hydraulic loading conditions, which can lead to increased levels of ammonium and nitrite in the effluent. To determine the maximum nitrification rates and safe operating windows of rapid sand filters, a pilot scale rapid sand filter was used to test short-term increased ammonium loads, set by varying either influent ammonium concentrations or hydraulic loading rates. Ammonium and iron (flock) removal were consistent between the pilot and the full-scale filter. Nitrification rates and ammonia-oxidizing bacteria and archaea were quantified throughout the depth of the filter. The ammonium removal capacity of the filter was determined to be 3.4 g NH4-N m(-3) h(-1), which was 5 times greater than the average ammonium loading rate under reference operating conditions. The ammonium removal rate of the filter was determined by the ammonium loading rate, but was independent of both the flow and influent ammonium concentration individually. Ammonia-oxidizing bacteria and archaea were almost equally abundant in the filter. Both ammonium removal and ammonia-oxidizing bacteria density were strongly stratified, with the highest removal and ammonia-oxidizing bacteria densities at the top of the filter. Cell specific ammonium oxidation rates were on average 0.6 × 10(2) ± 0.2 × 10(2) fg NH4-N h(-1) cell(-1). Our findings indicate that these rapid sand filters can safely remove both nitrite and ammonium over a larger range of loading rates than previously assumed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Monitoring by Use of Clusters of Sensor-Data Vectors

NASA Technical Reports Server (NTRS)

Iverson, David L.

2007-01-01

The inductive monitoring system (IMS) is a system of computer hardware and software for automated monitoring of the performance, operational condition, physical integrity, and other aspects of the health of a complex engineering system (e.g., an industrial process line or a spacecraft). The input to the IMS consists of streams of digitized readings from sensors in the monitored system. The IMS determines the type and amount of any deviation of the monitored system from a nominal or normal ( healthy ) condition on the basis of a comparison between (1) vectors constructed from the incoming sensor data and (2) corresponding vectors in a database of nominal or normal behavior. The term inductive reflects the use of a process reminiscent of traditional mathematical induction to learn about normal operation and build the nominal-condition database. The IMS offers two major advantages over prior computational monitoring systems: The computational burden of the IMS is significantly smaller, and there is no need for abnormal-condition sensor data for training the IMS to recognize abnormal conditions. The figure schematically depicts the relationships among the computational processes effected by the IMS. Training sensor data are gathered during normal operation of the monitored system, detailed computational simulation of operation of the monitored system, or both. The training data are formed into vectors that are used to generate the database. The vectors in the database are clustered into regions that represent normal or nominal operation. Once the database has been generated, the IMS compares the vectors of incoming sensor data with vectors representative of the clusters. The monitored system is deemed to be operating normally or abnormally, depending on whether the vector of incoming sensor data is or is not, respectively, sufficiently close to one of the clusters. For this purpose, a distance between two vectors is calculated by a suitable metric (e.g., Euclidean distance) and "sufficiently close" signifies lying at a distance less than a specified threshold value. It must be emphasized that although the IMS is intended to detect off-nominal or abnormal performance or health, it is not necessarily capable of performing a thorough or detailed diagnosis. Limited diagnostic information may be available under some circumstances. For example, the distance of a vector of incoming sensor data from the nearest cluster could serve as an indication of the severity of a malfunction. The identity of the nearest cluster may be a clue as to the identity of the malfunctioning component or subsystem. It is possible to decrease the IMS computation time by use of a combination of cluster-indexing and -retrieval methods. For example, in one method, the distances between each cluster and two or more reference vectors can be used for the purpose of indexing and retrieval. The clusters are sorted into a list according to these distance values, typically in ascending order of distance. When a set of input data arrives and is to be tested, the data are first arranged as an ordered set (that is, a vector). The distances from the input vector to the reference points are computed. The search of clusters from the list can then be limited to those clusters lying within a certain distance range from the input vector; the computation time is reduced by not searching the clusters at a greater distance.

Normal order and extended Wick theorem for a multiconfiguration reference wave function

NASA Astrophysics Data System (ADS)

Kutzelnigg, Werner; Mukherjee, Debashis

1997-07-01

A generalization of normal ordering and of Wick's theorem with respect to an arbitrary reference function Φ as some generalized "physical vacuum" is formulated in a different (but essentially equivalent) way than that suggested previously by one of the present authors. Guiding principles are that normal order operators with respect to any reference state must be expressible as linear combinations of those with respect to the genuine vacuum, that the vacuum expectation value of a normal order operator must vanish (with respect to the vacuum to which it is in normal order), and that the well-known formalism for a single Slater determinant as physical vacuum must be contained as a special case. The derivation is largely based on the concepts of "Quantum Chemistry in Fock space," which means that particle-number-conserving operators (excitation operators) play a central role. Nevertheless, the contraction rules in the frame of a generalized Wick theorem are derived, that hold for non-particle-number-conserving operators as well. The contraction rules are formulated and illustrated in terms of diagrams. The contractions involve the "residual n-particle density matrices" λ, which are the irreducible (non-factorizable) parts of the conventional n-particle density matrices γ, in the sense of a cumulant expansion for the density. A spinfree formulation is presented as well. The expression of the Hamiltonian in normal order with respect to a multiconfiguration reference function leads to a natural definition of a generalized Fock operator. MC-SCF-theory is easily worked out in this context. The paper concludes with a discussion of the excited configurations and the first-order interacting space, that underlies a perturbative coupled cluster type correction to the MCSCF function for an arbitrary reference function, and with general implications of the new formalism, that is related to "internally contracted multireference configuration interaction." The present generalization of normal ordering is not only valid for arbitrary reference functions, but also if the reference state is an ensemble state.

On the theory of behavioral mechanics.

PubMed

Dzendolet, E

1999-12-01

The Theory of Behavioral Mechanics is the behavioral analogue of Newton's laws of motion, with the rate of responding in operant conditioning corresponding to physical velocity. In an earlier work, the basic relation between rate of responding and sessions under two FI schedules and over a range of commonly used session values had been shown to be a power function. Using that basic relation, functions for behavioral acceleration, mass, and momentum are derived here. Data from other laboratories also support the applicability of a power function to VI schedules. A particular numerical value is introduced here to be the standard reference value for the behavioral force under the VI-60-s schedule. This reference allows numerical values to be calculated for the behavioral mass and momentum of individual animals. A comparison of the numerical values of the momenta of two animals can be used to evaluate their relative resistances to change, e.g., to extinction, which is itself viewed as a continuously changing behavioral force being imposed on the animal. This overall numerical approach allows behavioral force-values to be assigned to various experimental conditions such as the evaluation of the behavioral force of a medication dosage.

The Impact of Indoor and Outdoor Radiometer Calibration on Solar Measurements: Preprint

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

Habte, Aron; Sengupta, Manajit; Andreas, Afshin

2016-07-01

Accurate solar radiation data sets are critical to reducing the expenses associated with mitigating performance risk for solar energy conversion systems, and they help utility planners and grid system operators understand the impacts of solar resource variability. The accuracy of solar radiation measured by radiometers depends on the instrument performance specification, installation method, calibration procedure, measurement conditions, maintenance practices, location, and environmental conditions. This study addresses the effect of calibration methodologies and the resulting calibration responsivities provided by radiometric calibration service providers such as the National Renewable Energy Laboratory (NREL) and manufacturers of radiometers. Some of these radiometers are calibratedmore » indoors, and some are calibrated outdoors. To establish or understand the differences in calibration methodology, we processed and analyzed field-measured data from these radiometers. This study investigates calibration responsivities provided by NREL's broadband outdoor radiometer calibration (BORCAL) and a few prominent manufacturers. The reference radiometer calibrations are traceable to the World Radiometric Reference. These different methods of calibration demonstrated 1% to 2% differences in solar irradiance measurement. Analyzing these values will ultimately assist in determining the uncertainties of the radiometer data and will assist in developing consensus on a standard for calibration.« less

Computational Fluid Dynamics Ventilation Study for the Human Powered Centrifuge at the International Space Station

NASA Technical Reports Server (NTRS)

Son, Chang H.

2012-01-01

The Human Powered Centrifuge (HPC) is a facility that is planned to be installed on board the International Space Station (ISS) to enable crew exercises under the artificial gravity conditions. The HPC equipment includes a "bicycle" for long-term exercises of a crewmember that provides power for rotation of HPC at a speed of 30 rpm. The crewmember exercising vigorously on the centrifuge generates the amount of carbon dioxide of about two times higher than a crewmember in ordinary conditions. The goal of the study is to analyze the airflow and carbon dioxide distribution within Pressurized Multipurpose Module (PMM) cabin when HPC is operating. A full unsteady formulation is used for airflow and CO2 transport CFD-based modeling with the so-called sliding mesh concept when the HPC equipment with the adjacent Bay 4 cabin volume is considered in the rotating reference frame while the rest of the cabin volume is considered in the stationary reference frame. The rotating part of the computational domain includes also a human body model. Localized effects of carbon dioxide dispersion are examined. Strong influence of the rotating HPC equipment on the CO2 distribution detected is discussed.

[Ergonomic risk assessment: aspects applicable in the light of current standards].

PubMed

Baracco, A; Perrelli, F; Romano, C

2010-01-01

The Italian decree law 81/2008 mentions the application of ergonomic principles as a basic tool for the prevention. In this regulation we can not find the definition either of Ergonomics nor of the competences required for its correct application. The Authors consider that occupational physicians have a suitable competence and knowledge on the matter, thanks to their highly specialized training. Actually, the ergonomic doctrine shows up in the daily practice of occupational physicians, who regularly base their activity on the evaluation of the binomial "worker-task": in the management of fitness to work judgements they try to combine operating conditions with worker's psychophysical state, not confining themselves to a simple expression ofa medico-legal certificate. However, the legislative references to specific regulations raise difficulties to occupational physicians in dealing with aspects such as gender, age, reference values and methodological choices. The Authors debate these difficulties in the application of rules.

LACIE performance predictor final operational capability program description, volume 2

NASA Technical Reports Server (NTRS)

1976-01-01

Given the swath table files, the segment set for one country and cloud cover data, the SAGE program determines how many times and under what conditions each segment is accessed by satellites. The program writes a record for each segment on a data file which contains the pertinent acquisition data. The weather data file can also be generated from a NASA supplied tape. The Segment Acquisition Selector Program (SACS) selects data from the segment reference file based upon data input manually and from a crop window file. It writes the extracted data to a data acquisition file and prints two summary reports. The POUT program reads from associated LACIE files and produces printed reports. The major types of reports that can be produced are: (1) Substrate Reference Data Reports, (2) Population Mean, Standard Deviation and Histogram Reports, (3) Histograms of Monte Carlo Statistics Reports, and (4) Frequency of Sample Segment Acquisitions Reports.

Conclusiveness of natural languages and recognition of images

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

Wojcik, Z.M.

1983-01-01

The conclusiveness is investigated using recognition processes and one-one correspondence between expressions of a natural language and graphs representing events. The graphs, as conceived in psycholinguistics, are obtained as a result of perception processes. It is possible to generate and process the graphs automatically, using computers and then to convert the resulting graphs into expressions of a natural language. Correctness and conclusiveness of the graphs and sentences are investigated using the fundamental condition for events representation processes. Some consequences of the conclusiveness are discussed, e.g. undecidability of arithmetic, human brain assymetry, correctness of statistical calculations and operations research. It ismore » suggested that the group theory should be imposed on mathematical models of any real system. Proof of the fundamental condition is also presented. 14 references.« less

Effect of fermentation conditions on biohydrogen production from cassava starch by anaerobic mixed cultures

NASA Astrophysics Data System (ADS)

Tien, Hai M.; Le, Kien A.; Tran, An T.; Le, Phung K.

2016-06-01

In this work, a series of batch tests were conducted to investigate the effect of pH, temperature, fermentation time, and inoculums ratio to hydrogen production using cassava starch as a substrate. The statistical analysis of the experiment indicated that the significant effects for the fermentation yield were the main effect of temperature, pH and inoculums ratio. It was fouund that the suitable fermentation conditions of biohydrogen production should be at temperature 40 ° C; pH 6.5, inoculums to medium ratio 10 % and COD operation at 4800 g/mL. The maximum value of hydrogen volume produced was 76.22 mL. These affected has been evaluated and the result can be used as an reference for the pilot or industrial biohydrogen production.

A weighted ℓ{sub 1}-minimization approach for sparse polynomial chaos expansions

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

Peng, Ji; Hampton, Jerrad; Doostan, Alireza, E-mail: alireza.doostan@colorado.edu

2014-06-15

This work proposes a method for sparse polynomial chaos (PC) approximation of high-dimensional stochastic functions based on non-adapted random sampling. We modify the standard ℓ{sub 1}-minimization algorithm, originally proposed in the context of compressive sampling, using a priori information about the decay of the PC coefficients, when available, and refer to the resulting algorithm as weightedℓ{sub 1}-minimization. We provide conditions under which we may guarantee recovery using this weighted scheme. Numerical tests are used to compare the weighted and non-weighted methods for the recovery of solutions to two differential equations with high-dimensional random inputs: a boundary value problem with amore » random elliptic operator and a 2-D thermally driven cavity flow with random boundary condition.« less

Optical fibre sensing: a solution for industry

NASA Astrophysics Data System (ADS)

Sun, T.; Fabian, M.; Chen, Y.; Vidakovic, M.; Javdani, S.; Grattan, K. T. V.; Carlton, J.; Gerada, C.; Brun, L.

2017-04-01

Optical fibres have been explored widely for their sensing capability to meet increasing industrial needs, building on their success in telecommunications. This paper provides a review of research activities at City University of London in response to industrial challenges through the development of a range of fibre Bragg grating (FBG)-based sensors for transportation structural monitoring. For marine propellers, arrays of FBGs mapped onto the surface of propeller blades allow for capturing vibrational modes, with reference to simulation data. The research funded by EU Cleansky programme enables the development of self-sensing electric motor drives to support `More Electric Aircraft' concept. The partnership with Faiveley Brecknell Willis in the UK enables the integration of FBG sensors into the railway current-collecting pantographs for real-time condition monitoring when they are operating under 25kV conditions.

Starting and Operating Live Virtual Reference Services: A How-To-Do-It Manual for Librarians. How-To-Do-It Manuals for Librarians, Number 118.

ERIC Educational Resources Information Center

Meola, Marc; Stormont, Sam

This guide discusses the essentials of live virtual reference, preparing for virtual reference, and implementing and incorporating virtual reference. Chapter 1, "Understanding Live Virtual Reference," lays out what virtual reference is and how it compares to other forms of reference. Chapter 2, "Offering Live Virtual Reference," presents ten…

Inductively coupled plasma atomic fluorescence spectrometric determination of cadmium, copper, iron, lead, manganese and zinc

USGS Publications Warehouse

Sanzolone, R.F.

1986-01-01

An inductively coupled plasma atomic fluorescence spectrometric method is described for the determination of six elements in a variety of geological materials. Sixteen reference materials are analysed by this technique to demonstrate its use in geochemical exploration. Samples are decomposed with nitric, hydrofluoric and hydrochloric acids, and the residue dissolved in hydrochloric acid and diluted to volume. The elements are determined in two groups based on compatibility of instrument operating conditions and consideration of crustal abundance levels. Cadmium, Cu, Pb and Zn are determined as a group in the 50-ml sample solution under one set of instrument conditions with the use of scatter correction. Limitations of the scatter correction technique used with the fluorescence instrument are discussed. Iron and Mn are determined together using another set of instrumental conditions on a 1-50 dilution of the sample solution without the use of scatter correction. The ranges of concentration (??g g-1) of these elements in the sample that can be determined are: Cd, 0.3-500; Cu, 0.4-500; Fe, 85-250 000; Mn, 45-100 000; Pb, 5-10 000; and Zn, 0.4-300. The precision of the method is usually less than 5% relative standard deviation (RSD) over a wide concentration range and acceptable accuracy is shown by the agreement between values obtained and those recommended for the reference materials.

Evaluative Conditioning: The “How” Question

PubMed Central

Jones, Christopher R.; Olson, Michael A.; Fazio, Russell H.

2011-01-01

Evaluative conditioning (EC) refers to attitude formation or change toward an object due to that object's mere co-occurrence with another valenced object or objects. This chapter focuses on the “how” question, that is, the question of what cognitive processes intervene between mere co-occurrence and attitude formation or change. Though EC has typically been thought of as occurring through a single, albeit contentious, mechanism, we begin by pointing out that both the heterogeneity of EC methodologies and the abundance of inconsistent results suggest that multiple processes with different characteristics can produce EC. We describe how the earliest posited process of EC, Pavlovian conditioning or signal learning, is a valid mechanism of EC that appears to have operated in some experiments but is unlikely to have operated in others and also cannot account for various EC findings. We describe other mechanisms of EC, when they can be expected to occur, and what characteristics they have. We particularly focus our attention on a process model of EC we have recently introduced, the implicit misattribution model. Finally, we describe the implications of a multi-process view of EC, which we argue can help resolve theoretical controversies and further the application of EC as a practical intervention for influencing attitudes in various domains. PMID:22241936

On the performance of a high head Francis turbine at design and off-design conditions

NASA Astrophysics Data System (ADS)

Aakti, B.; Amstutz, O.; Casartelli, E.; Romanelli, G.; Mangani, L.

2015-01-01

In the present paper, fully 360 degrees transient and steady-state simulations of a Francis turbine were performed at three operating conditions, namely at part load (PL), best efficiency point (BEP), and high load (HL), using different numerical approaches for the pressure-velocity coupling. The simulation domain includes the spiral casing with stay and guide vanes, the runner and the draft tube. The main target of the investigations is the numerical prediction of the overall performance of the high head Francis turbine model as well as local and integral quantities of the complete machine in different operating conditions. All results were compared with experimental data published by the workshop organization. All CFD simulations were performed at model scale with a new in-house, 3D, unstructured, object-oriented finite volume code within the framework of the open source OpenFOAM library. The novel fully coupled pressure-based solver is designed to solve the incompressible RANS- Equations and is capable of handling multiple references of frame (MRF). The obtained results show that the overall performance is well captured by the simulations. Regarding the local flow distributions within the inlet section of the draft-tube, the axial velocity is better estimated than the circumferential component.

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

Singer, Brett C.; Less, Brennan D.; Delp, William W.

To inform efforts to improve combustion appliance testing in residential energy efficiency programs, we studied the frequency of coincident fan use and depressurization-induced downdrafting and spillage from atmospherically vented (i.e., natural draft) wall furnaces in airtight apartments. Indoor environmental conditions, heating appliance operation, use of exhaust fans, and cooking with stovetop or oven were monitored for approximately three weeks each in 16 apartment units in two buildings in Northern California. Apartments also were assessed using standard combustion appliance safety test methods and enhanced protocols. Monitoring occurred in February and March of 2016, with heating demand corresponding to 7.3 ± 0.5more » heating degree-days at a 65ºF reference temperature. Most of the furnaces spilled combustion products when the apartments were depressurized in the “worst-case” challenge condition of all exhaust fans operating at their highest settings and all windows closed. Many also spilled under less challenging conditions (e.g., with kitchen exhaust fan on low and bathroom fan operating). On average, bathroom exhaust fans were operated 3.9% of monitored minutes (13.5% max), and cooking (burner or kitchen fan operation) occurred 4.6% of minutes (max 13.3%). Event lengths averaged 17 minutes (max 540) and 34 minutes (max 324), respectively. Their coincident operation averaged 0.34% of minutes (max 2.0%), with average event length of 13 minutes (max 92 minutes). This suggests that the operation of apartment units at or near the currently used worst-case challenge condition is quite rare. Wall furnace burners operated an average of 2.8% of minutes (max of 8.9%), with average burner cycle length of 14 minutes (max 162). Coincident bath fan use, cooking and wall furnace operation was very rare, occurring only a handful of times across all apartments. The highest rate was 0.075% of monitored minutes in one apartment, and the longest event length was 12 minutes. Exhaust fan operation in this study may have been more frequent than typical as participants were asked to use an exhaust fan whenever cooking or bathing. Consistent with the low levels of coincident operation, unambiguous spillage occurred in only 4 apartments and the longest event was 5 minutes. The frequency of partial spillage is unknown, owing to a lack of a clear signal from monitored parameters. Downdrafting during exhaust fan use occurred in all 13 of the apartments with relevant data, and 9 of these units had 10 or more events. Exhaust fans also sometimes led to weakened draft, even if downdrafting did not occur. Each unambiguous spillage event identified in the study was immediately preceded by downdrafting. The observed occurrence of downdrafting and spillage may have been impacted in those apartments with the most severe drafting problems (i.e., appliances spilled combustion pollutants under ‘natural’ test conditions), because occupants in these units were instructed to open windows whenever using the kitchen exhaust fan.« less

Evidence for Model-based Computations in the Human Amygdala during Pavlovian Conditioning

PubMed Central

Prévost, Charlotte; McNamee, Daniel; Jessup, Ryan K.; Bossaerts, Peter; O'Doherty, John P.

2013-01-01

Contemporary computational accounts of instrumental conditioning have emphasized a role for a model-based system in which values are computed with reference to a rich model of the structure of the world, and a model-free system in which values are updated without encoding such structure. Much less studied is the possibility of a similar distinction operating at the level of Pavlovian conditioning. In the present study, we scanned human participants while they participated in a Pavlovian conditioning task with a simple structure while measuring activity in the human amygdala using a high-resolution fMRI protocol. After fitting a model-based algorithm and a variety of model-free algorithms to the fMRI data, we found evidence for the superiority of a model-based algorithm in accounting for activity in the amygdala compared to the model-free counterparts. These findings support an important role for model-based algorithms in describing the processes underpinning Pavlovian conditioning, as well as providing evidence of a role for the human amygdala in model-based inference. PMID:23436990

Causal Factors and Adverse Conditions of Aviation Accidents and Incidents Related to Integrated Resilient Aircraft Control

NASA Technical Reports Server (NTRS)

Reveley, Mary S.; Briggs, Jeffrey L.; Evans, Joni K.; Sandifer, Carl E.; Jones, Sharon Monica

2010-01-01

The causal factors of accidents from the National Transportation Safety Board (NTSB) database and incidents from the Federal Aviation Administration (FAA) database associated with loss of control (LOC) were examined for four types of operations (i.e., Federal Aviation Regulation Part 121, Part 135 Scheduled, Part 135 Nonscheduled, and Part 91) for the years 1988 to 2004. In-flight LOC is a serious aviation problem. Well over half of the LOC accidents included at least one fatality (80 percent in Part 121), and roughly half of all aviation fatalities in the studied time period occurred in conjunction with LOC. An adverse events table was updated to provide focus to the technology validation strategy of the Integrated Resilient Aircraft Control (IRAC) Project. The table contains three types of adverse conditions: failure, damage, and upset. Thirteen different adverse condition subtypes were gleaned from the Aviation Safety Reporting System (ASRS), the FAA Accident and Incident database, and the NTSB database. The severity and frequency of the damage conditions, initial test conditions, and milestones references are also provided.

Compilation of load spectrum of loader drive axle

NASA Astrophysics Data System (ADS)

Wei, Yongxiang; Zhu, Haoyue; Tang, Heng; Yuan, Qunwei

2018-03-01

In order to study the preparation method of gear fatigue load spectrum for loaders, the load signal of four typical working conditions of loader is collected. The signal that reflects the law of load change is obtained by preprocessing the original signal. The torque of the drive axle is calculated by using the rain flow counting method. According to the operating time ratio of each working condition, the two dimensional load spectrum based on the real working conditions of the drive axle of loader is established by the cycle extrapolation and synthesis method. The two-dimensional load spectrum is converted into one-dimensional load spectrum by means of the mean of torque equal damage method. Torque amplification includes the maximum load torque of the main reduction gear. Based on the theory of equal damage, the accelerated cycles are calculated. In this way, the load spectrum of the loading condition of the drive axle is prepared to reflect loading condition of the loader. The load spectrum can provide reference for fatigue life test and life prediction of loader drive axle.

Approaches to defining reference regimes for river restoration planning

NASA Astrophysics Data System (ADS)

Beechie, T. J.

2014-12-01

Reference conditions or reference regimes can be defined using three general approaches, historical analysis, contemporary reference sites, and theoretical or empirical models. For large features (e.g., floodplain channels and ponds) historical data and maps are generally reliable. For smaller features (e.g., pools and riffles in small tributaries), field data from contemporary reference sites are a reasonable surrogate for historical data. Models are generally used for features that have no historical information or present day reference sites (e.g., beaver pond habitat). Each of these approaches contributes to a watershed-wide understanding of current biophysical conditions relative to potential conditions, which helps create not only a guiding vision for restoration, but also helps quantify and locate the largest or most important restoration opportunities. Common uses of geomorphic and biological reference conditions include identifying key areas for habitat protection or restoration, and informing the choice of restoration targets. Examples of use of each of these three approaches to define reference regimes in western USA illustrate how historical information and current research highlight key restoration opportunities, focus restoration effort in areas that can produce the largest ecological benefit, and contribute to estimating restoration potential and assessing likelihood of achieving restoration goals.

SETTING EXPECTATIONS FOR THE ECOLOGICAL CONDITION OF STREAMS: THE CONCEPT OF REFERENCE CONDITION

EPA Science Inventory

An important component of the biological assessment of stream condition is an evaluation of the direct or indirect effects of human activities or disturbances. The concept of a "reference condition" is increasingly used to describe the standard or benchmark against which current ...

Design Reference Missions (DRM): Integrated ODM 'Air-Taxi' Mission Features

NASA Technical Reports Server (NTRS)

Kloesel, Kurt; Starr, Ginn; Saltzman, John A.

2017-01-01

Design Reference Missions (DRM): Integrated ODM Air-Taxi Mission Features, Hybrid Electric Integrated System Testbed (HEIST) flight control. Structural Health, Energy Storage, Electric Components, Loss of Control, Degraded Systems, System Health, Real-Time IO Operator Geo-Fencing, Regional Noise Abatement and Trusted Autonomy Inter-operability.

Water Quality in Small Community Distribution Systems. A Reference Guide for Operators

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) has developed this reference guide to assist the operators and managers of small- and medium-sized public water systems. This compilation provides a comprehensive picture of the impact of the water distribution system network on dist...

Defining the Reference Condition for Wadeable Streams in the Sand Hills Subdivision of the Southeastern Plains Ecoregion, USA

NASA Astrophysics Data System (ADS)

Kosnicki, Ely; Sefick, Stephen A.; Paller, Michael H.; Jarrell, Miller S.; Prusha, Blair A.; Sterrett, Sean C.; Tuberville, Tracey D.; Feminella, Jack W.

2014-09-01

The Sand Hills subdivision of the Southeastern Plains ecoregion has been impacted by historical land uses over the past two centuries and, with the additive effects of contemporary land use, determining reference condition for streams in this region is a challenge. We identified reference condition based on the combined use of 3 independent selection methods. Method 1 involved use of a multivariate disturbance gradient derived from several stressors, method 2 was based on variation in channel morphology, and method 3 was based on passing 6 of 7 environmental criteria. Sites selected as reference from all 3 methods were considered primary reference, whereas those selected by 2 or 1 methods were considered secondary or tertiary reference, respectively. Sites not selected by any of the methods were considered non-reference. In addition, best professional judgment (BPJ) was used to exclude some sites from any reference class, and comparisons were made to examine the utility of BPJ. Non-metric multidimensional scaling indicated that use of BPJ may help designate non-reference sites when unidentified stressors are present. The macroinvertebrate community measures Ephemeroptera, Plecoptera, Trichoptera richness and North Carolina Biotic Index showed no differences between primary and secondary reference sites when BPJ was ignored. However, there was no significant difference among primary, secondary, and tertiary reference sites when BPJ was used. We underscore the importance of classifying reference conditions, especially in regions that have endured significant anthropogenic activity. We suggest that the use of secondary reference sites may enable construction of models that target a broader set of management interests.

User's Guide for MetView: A Meteorological Display and Assessment Tool

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

Glantz, Clifford S.; Pelton, Mitchell A.; Allwine, K Jerry

2000-09-27

MetView Version 2.0 is an easy-to-use model for accessing, viewing, and analyzing meteorological data. MetView provides both graphical and numerical displays of data. It can accommodate data from an extensive meteorological monitoring network that includes near-surface monitoring locations, instrumented towers, sodars, and meteorologist observations. MetView is used operationally for both routine, emergency response, and research applications at the U.S. Department of Energy's Hanford Site. At the Site's Emergency Operations Center, MetView aids in the access, visualization, and interpretation of real-time meteorological data. Historical data can also be accessed and displayed. Emergency response personnel at the Emergency Operations Center use MetViewmore » products in the formulation of protective action recommendations and other decisions. In the initial stage of an emergency, MetView can be operated using a very simple, five-step procedure. This first-responder procedure allows non-technical staff to rapidly generate meteorological products and disseminate key information. After first-responder information products are produced, the Emergency Operations Center's technical staff can conduct more sophisticated analyses using the model. This may include examining the vertical variation in winds, assessing recent changes in atmospheric conditions, evaluating atmospheric mixing rates, and forecasting changes in meteorological conditions. This user's guide provides easy-to-follow instructions for both first-responder and routine operation of the model. Examples, with explanations, are provided for each type of MetView output display. Information is provided on the naming convention, format, and contents of each type of meteorological data file used by the model area. This user's guide serves as a ready reference for experienced MetView users and a training manual for new users.« less

Concept of Operations for RCO SPO

NASA Technical Reports Server (NTRS)

Matessa, Michael; Strybel, Thomas; Vu, Kim; Battiste, Vernol; Schnell, Thomas

2017-01-01

Reduced crew operations (RCO) refers to the reduction of crew members flying long-haul or military operations with more than one pilot onboard. Single pilot operations (SPO) refers to flying a commercial transport aircraft with only one pilot on board the aircraft, assisted by advanced onboard automation andor ground operators providing piloting support services. Properly implemented, RCO/SPO could provide operating cost savings while maintaining a level of safety no less than conventional two-pilot commercial operations. A concept of operations (ConOps) for any paradigm describes the characteristics of its various components and their integration in a multi-dimensional design space. This paper presents key options for humanautomation function allocation being considered by NASA in its ongoing development of RCO/SPO ConOps.

An Effective Hybrid Evolutionary Algorithm for Solving the Numerical Optimization Problems

NASA Astrophysics Data System (ADS)

Qian, Xiaohong; Wang, Xumei; Su, Yonghong; He, Liu

2018-04-01

There are many different algorithms for solving complex optimization problems. Each algorithm has been applied successfully in solving some optimization problems, but not efficiently in other problems. In this paper the Cauchy mutation and the multi-parent hybrid operator are combined to propose a hybrid evolutionary algorithm based on the communication (Mixed Evolutionary Algorithm based on Communication), hereinafter referred to as CMEA. The basic idea of the CMEA algorithm is that the initial population is divided into two subpopulations. Cauchy mutation operators and multiple paternal crossover operators are used to perform two subpopulations parallelly to evolve recursively until the downtime conditions are met. While subpopulation is reorganized, the individual is exchanged together with information. The algorithm flow is given and the performance of the algorithm is compared using a number of standard test functions. Simulation results have shown that this algorithm converges significantly faster than FEP (Fast Evolutionary Programming) algorithm, has good performance in global convergence and stability and is superior to other compared algorithms.

Child abuse and neglect in Japan: coin-operated-locker babies.

PubMed

Kouno, A; Johnson, C F

1995-01-01

The coin-operated-locker baby is a type of child abuse that may be unique to Japan. The term refers to newborns who are placed, while alive or dead, in coin-operated lockers. This practice has been decreased by specific measures. It is likely that social and economic variables in Japan account for differences in the frequency and types of child abuse cases when compared to American or European societies as social conditions in Japan change the reported incidence of child abuse may increase in the future. Recently, the government of Osaka organized a group specifically designed to deal with the detection and protection of abused and neglected children. In 1993, they published a manual on how to deal with child abuse, but the Japanese judicial administration still uses old laws for abuse cases. The development of new laws is occurring in parts of the country now. This paper introduces the present status of coping with child abuse and neglect in Japan.

Optimal reconstruction of the states in qutrit systems

NASA Astrophysics Data System (ADS)

Yan, Fei; Yang, Ming; Cao, Zhuo-Liang

2010-10-01

Based on mutually unbiased measurements, an optimal tomographic scheme for the multiqutrit states is presented explicitly. Because the reconstruction process of states based on mutually unbiased states is free of information waste, we refer to our scheme as the optimal scheme. By optimal we mean that the number of the required conditional operations reaches the minimum in this tomographic scheme for the states of qutrit systems. Special attention will be paid to how those different mutually unbiased measurements are realized; that is, how to decompose each transformation that connects each mutually unbiased basis with the standard computational basis. It is found that all those transformations can be decomposed into several basic implementable single- and two-qutrit unitary operations. For the three-qutrit system, there exist five different mutually unbiased-bases structures with different entanglement properties, so we introduce the concept of physical complexity to minimize the number of nonlocal operations needed over the five different structures. This scheme is helpful for experimental scientists to realize the most economical reconstruction of quantum states in qutrit systems.

Structural Health Monitoring for a Z-Type Special Vehicle

PubMed Central

Yuan, Chaolin; Ren, Liang; Li, Hongnan

2017-01-01

Nowadays there exist various kinds of special vehicles designed for some purposes, which are different from regular vehicles in overall dimension and design. In that case, accidents such as overturning will lead to large economical loss and casualties. There are still no technical specifications to follow to ensure the safe operation and driving of these special vehicles. Owing to the poor efficiency of regular maintenance, it is more feasible and effective to apply real-time monitoring during the operation and driving process. In this paper, the fiber Bragg grating (FBG) sensors are used to monitor the safety of a z-type special vehicle. Based on the structural features and force distribution, a reasonable structural health monitoring (SHM) scheme is presented. Comparing the monitoring results with the finite element simulation results guarantees the accuracy and reliability of the monitoring results. Large amounts of data are collected during the operation and driving progress to evaluate the structural safety condition and provide reference for SHM systems developed for other special vehicles. PMID:28587161

Initial Operation and Shakedown of the Nuclear Thermal Rocket Element Environmental Simulator (NTREES)

NASA Technical Reports Server (NTRS)

Emrich, William J., Jr.

2014-01-01

To support the on-going nuclear thermal propulsion effort, a state-of-the-art non nuclear experimental test setup has been constructed to evaluate the performance characteristics of candidate fuel element materials and geometries in representative environments. The facility to perform this testing is referred to as the Nuclear Thermal Rocket Element Environment Simulator (NTREES). This device can simulate the environmental conditions (minus the radiation) to which nuclear rocket fuel components will be subjected during reactor operation. Prototypical fuel elements mounted in the simulator are inductively heated in such a manner so as to accurately reproduce the temperatures and heat fluxes which would normally occur as a result of nuclear fission in addition to being exposed to flowing hydrogen. Recent upgrades to NTREES now allow power levels 24 times greater than those achievable in the previous facility configuration. This higher power operation will allow near prototypical power densities and flows to finally be achieved in most prototypical fuel elements.

A guide to safe field operations

USGS Publications Warehouse

Yobbi, D.K.; Yorke, T.H.; Mycyk, R.T.

1996-01-01

Most functions of the U.S. Geological Survey (USGS), Water Resources Division (WRD) require employees to participate in numerous field activities ranging from routine meetings with cooperators, other federal and public officials, and private citizens to potentially hazardous assignments, such as making flood measurements and scuba diving to service underwater instruments. It is paramount that each employee be aware of safety procedures and operational policies of the WRD to ensure that (1) their activities avoid or minimize personal injury to the employee, coworkers, or anyone in the vicinity of the field activity, and (2) their conduct does not infringe on the personal or property rights of any individual or organization. The purpose of the guide is to familiarize employees with the operational and safety procedures expected to be followed by each employee as a representative of the WRD. It is also intended as a training tool for all new employees and a document to be reviewed by each employee before undertaking a field assignment. It includes general procedures that are standard and applicable to all field operations, such as communication, vehicle operation, and adequate preparation for anticipated weather conditions. It also includes a discussion of specific procedures and safety considerations for most of the routine field assignments undertaken by hydrologists and hydrologic technicians of the WRD. The guide is not intended to be a technical handbook outlining step-by-step procedures for performing specific tasks or a comprehensive discussion of every possible activity that may be undertaken by a USGS employee. Employees are referred to the Techniques for Water-Resources Investigations (TWRI) series for specific technical procedures and to the U.S. Geological Survey Safety and Environmental Health Handbook 445-1-H (USGS, August 1989), USGS Occupational Hazards and Safety Procedures Handbook 445-2-H (December 1993), the WRD notebook on Safety Policy and Guidance Memoranda, and other references for procedures and safety issues related to nonroutine activities, such as operations on large vessels and aircraft.

Efficacy of a Deep Learning System for Detecting Glaucomatous Optic Neuropathy Based on Color Fundus Photographs.

PubMed

Li, Zhixi; He, Yifan; Keel, Stuart; Meng, Wei; Chang, Robert T; He, Mingguang

2018-03-02

To assess the performance of a deep learning algorithm for detecting referable glaucomatous optic neuropathy (GON) based on color fundus photographs. A deep learning system for the classification of GON was developed for automated classification of GON on color fundus photographs. We retrospectively included 48 116 fundus photographs for the development and validation of a deep learning algorithm. This study recruited 21 trained ophthalmologists to classify the photographs. Referable GON was defined as vertical cup-to-disc ratio of 0.7 or more and other typical changes of GON. The reference standard was made until 3 graders achieved agreement. A separate validation dataset of 8000 fully gradable fundus photographs was used to assess the performance of this algorithm. The area under receiver operator characteristic curve (AUC) with sensitivity and specificity was applied to evaluate the efficacy of the deep learning algorithm detecting referable GON. In the validation dataset, this deep learning system achieved an AUC of 0.986 with sensitivity of 95.6% and specificity of 92.0%. The most common reasons for false-negative grading (n = 87) were GON with coexisting eye conditions (n = 44 [50.6%]), including pathologic or high myopia (n = 37 [42.6%]), diabetic retinopathy (n = 4 [4.6%]), and age-related macular degeneration (n = 3 [3.4%]). The leading reason for false-positive results (n = 480) was having other eye conditions (n = 458 [95.4%]), mainly including physiologic cupping (n = 267 [55.6%]). Misclassification as false-positive results amidst a normal-appearing fundus occurred in only 22 eyes (4.6%). A deep learning system can detect referable GON with high sensitivity and specificity. Coexistence of high or pathologic myopia is the most common cause resulting in false-negative results. Physiologic cupping and pathologic myopia were the most common reasons for false-positive results. Copyright © 2018 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Precision limits of the twin-beam multiband URSULA

NASA Technical Reports Server (NTRS)

Debiase, G. A.; Paterno, L.; Fedel, B.; Santagati, G.; Ventura, R.

1988-01-01

URSULA is a multiband astronomical photoelectric photometer which minimizes errors introduced by the presence of the atmosphere. It operates with two identical channels, one for the star to be measured and the other for a reference star. After a technical description of the present version of the apparatus, some measurements of stellar sources of different brightness, and in different atmospheric conditions are presented. These measurements, based on observations made with the 91 cm Cassegrain telescope of the Catania Astrophysical Observatory, are used to check the photometer accuracy and compare its performance with that of standard photometers.

Procedural considerations for CPV outdoor power ratings per IEC 62670

NASA Astrophysics Data System (ADS)

Muller, Matthew; Kurtz, Sarah; Rodriguez, Jose

2013-09-01

The IEC Working Group 7 (WG7) is in the process of developing a draft procedure for an outdoor concentrating photovoltaic (CPV) module power rating at Concentrator Standard Operating Conditions (CSOC). WG7 recently achieved some consensus that using component reference cells to monitor/limit spectral variation is the preferred path for the outdoor power rating. To build on this consensus, the community must quantify these spectral limits and select a procedure for calculating and reporting a power rating. This work focuses on statistically comparing several procedures the community is considering in context with monitoring/limiting spectral variation.

Heat Transfer Analysis of a Closed Brayton Cycle Space Radiator

NASA Technical Reports Server (NTRS)

Juhasz, Albert J.

2007-01-01

This paper presents a mathematical analysis of the heat transfer processes taking place in a radiator for a closed cycle gas turbine (CCGT), also referred to as a Closed Brayton Cycle (CBC) space power system. The resulting equations and relationships have been incorporated into a radiator sub-routine of a numerical triple objective CCGT optimization program to determine operating conditions yielding maximum cycle efficiency, minimum radiator area and minimum overall systems mass. Study results should be of interest to numerical modeling of closed cycle Brayton space power systems and to the design of fluid cooled radiators in general.

Analysis of Rare Earth Elements in Geologic Samples using Inductively Coupled Plasma Mass Spectrometry; US DOE Topical Report - DOE/NETL-2016/1794

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

Bank, Tracy L.; Roth, Elliot A.; Tinker, Phillip

2016-04-17

Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is used to measure the concentrations of rare earth elements (REE) in certified standard reference materials including shale and coal. The instrument used in this study is a Perkin Elmer Nexion 300D ICP-MS. The goal of the study is to identify sample preparation and operating conditions that optimized recovery of each element of concern. Additionally, the precision and accuracy of the technique are summarized and the drawbacks and limitations of the method are outlined.

Spatial reference frames of visual, vestibular, and multimodal heading signals in the dorsal subdivision of the medial superior temporal area.

PubMed

Fetsch, Christopher R; Wang, Sentao; Gu, Yong; Deangelis, Gregory C; Angelaki, Dora E

2007-01-17

Heading perception is a complex task that generally requires the integration of visual and vestibular cues. This sensory integration is complicated by the fact that these two modalities encode motion in distinct spatial reference frames (visual, eye-centered; vestibular, head-centered). Visual and vestibular heading signals converge in the primate dorsal subdivision of the medial superior temporal area (MSTd), a region thought to contribute to heading perception, but the reference frames of these signals remain unknown. We measured the heading tuning of MSTd neurons by presenting optic flow (visual condition), inertial motion (vestibular condition), or a congruent combination of both cues (combined condition). Static eye position was varied from trial to trial to determine the reference frame of tuning (eye-centered, head-centered, or intermediate). We found that tuning for optic flow was predominantly eye-centered, whereas tuning for inertial motion was intermediate but closer to head-centered. Reference frames in the two unimodal conditions were rarely matched in single neurons and uncorrelated across the population. Notably, reference frames in the combined condition varied as a function of the relative strength and spatial congruency of visual and vestibular tuning. This represents the first investigation of spatial reference frames in a naturalistic, multimodal condition in which cues may be integrated to improve perceptual performance. Our results compare favorably with the predictions of a recent neural network model that uses a recurrent architecture to perform optimal cue integration, suggesting that the brain could use a similar computational strategy to integrate sensory signals expressed in distinct frames of reference.

Development of a toolkit to enhance care processes for people with a long-term neurological condition: a qualitative descriptive study.

PubMed

Sezier, Ann; Mudge, Suzie; Kayes, Nicola; Kersten, Paula; Payne, Deborah; Harwood, Matire; Potter, Eden; Smith, Greta; McPherson, Kathryn M

2018-06-30

To (A) explore perspectives of people with a long-term neurological condition, and of their family, clinicians and other stakeholders on three key processes: two-way communication, self-management and coordination of long-term care; and (B) use these data to develop a 'Living Well Toolkit', a structural support aiming to enhance the quality of these care processes. This qualitative descriptive study drew on the principles of participatory research. Data from interviews and focus groups with participants (n=25) recruited from five hospital, rehabilitation and community settings in New Zealand were analysed using conventional content analysis. Consultation with a knowledge-user group (n=4) and an implementation champion group (n=4) provided additional operational knowledge important to toolkit development and its integration into clinical practice. Four main, and one overarching, themes were constructed: (1) tailoring care: referring to getting to know the person and their individual circumstances; (2) i nvolving others: representing the importance of negotiating the involvement of others in the person's long-term management process; (3) exchanging knowledge: referring to acknowledging patient expertise; and (4) enabling: highlighting the importance of empowering relationships and processes. The overarching theme was: a ssume nothing . These themes informed the development of a toolkit comprising of two parts: one to support the person with the long-term neurological condition, and one targeted at clinicians to guide interaction and support their engagement with patients. Perspectives of healthcare users, clinicians and other stakeholders were fundamental to the development of the Living Well Toolkit. The findings were used to frame toolkit specifications and highlighted potential operational issues that could prove key to its success. Further research to evaluate its use is now underway. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Satellite power system: Concept development and evaluation program, reference system report

NASA Technical Reports Server (NTRS)

1979-01-01

The Satellite Power System (SPS) Reference System is discussed and the technical and operational information required in support of environmental, socioeconomic, and comparative assessment studies are emphasized. The reference System concept features a gallium-aluminum-arsenide, and silicon solar cell options. Other aspects of an SPS are the construction of bases in space, launch and mission control bases on earth, and fleets of various transportation vehicles to support the construction and maintenance operations of the satellites.

Thermodynamic analysis and economical evaluation of two 310-80 K pre-cooling stage configurations for helium refrigeration and liquefaction cycle

NASA Astrophysics Data System (ADS)

Zhu, Z. G.; Zhuang, M.; Jiang, Q. F.; Y Zhang, Q.; Feng, H. S.

2017-12-01

In 310-80 K pre-cooling stage, the temperature of the HP helium stream reduces to about 80 K where nearly 73% of the enthalpy drop from room temperature to 4.5 K occurs. Apart from the most common liquid nitrogen pre-cooling, another 310-80 K pre-cooling configuration with turbine is employed in some helium cryoplants. In this paper, thermodynamic and economical performance of these two kinds of 310-80 K pre-cooling stage configurations has been studied at different operating conditions taking discharge pressure, isentropic efficiency of turbines and liquefaction rate as independent parameters. The exergy efficiency, total UA of heat exchangers and operating cost of two configurations are computed. This work will provide a reference for choosing 310-80 K pre-cooling stage configuration during design.

The development of community water supplies in Ghana*

PubMed Central

Ferguson, W. R. W.

1962-01-01

Ghana, with a population of 6 700 000, largely distributed in rural districts, is representative of many a country where the problem of water supply is associated with the construction of numerous small supplies for the villages and towns scattered over the whole area. This paper gives a general impression of the various methods in use for tackling the problem. Well-sinking, drilling, and pond-digging, and the advantages and disadvantages of a variety of methods, are described, and the problems met with under different geological conditions are considered. Details of the various systems for pumping the water from the source to the villages and towns are given. The important question of standardization, both in design and equipment, is dealt with, and reference is made to the operation of supplies and to the training of operatives. PMID:13892347

Structural Health Monitoring challenges on the 10-MW offshore wind turbine model

NASA Astrophysics Data System (ADS)

Di Lorenzo, E.; Kosova, G.; Musella, U.; Manzato, S.; Peeters, B.; Marulo, F.; Desmet, W.

2015-07-01

The real-time structural damage detection on large slender structures has one of its main application on offshore Horizontal Axis Wind Turbines (HAWT). The renewable energy market is continuously pushing the wind turbine sizes and performances. This is the reason why nowadays offshore wind turbines concepts are going toward a 10 MW reference wind turbine model. The aim of the work is to perform operational analyses on the 10-MW reference wind turbine finite element model using an aeroelastic code in order to obtain long-time-low- cost simulations. The aeroelastic code allows simulating the damages in several ways: by reducing the edgewise/flapwise blades stiffness, by adding lumped masses or considering a progressive mass addiction (i.e. ice on the blades). The damage detection is then performed by means of Operational Modal Analysis (OMA) techniques. Virtual accelerometers are placed in order to simulate real measurements and to estimate the modal parameters. The feasibility of a robust damage detection on the model has been performed on the HAWT model in parked conditions. The situation is much more complicated in case of operating wind turbines because the time periodicity of the structure need to be taken into account. Several algorithms have been implemented and tested in the simulation environment. They are needed in order to carry on a damage detection simulation campaign and develop a feasible real-time damage detection method. In addition to these algorithms, harmonic removal tools are needed in order to dispose of the harmonics due to the rotation.

Frequency control circuit for all-digital phase-lock loops

NASA Technical Reports Server (NTRS)

Anderson, T. O.

1973-01-01

Phase-lock loop references all its operations to fixed high-frequency service clock operating at highest speed which digital circuits permit. Wide-range control circuit provides linear control of frequency of reference signal. It requires only two counters in combination with control circuit consisting only of flip-flop and gate.

49 CFR 385.321 - What failures of safety management practices disclosed by the safety audit will result in a...

Code of Federal Regulations, 2011 CFR

2011-10-01

... occurrence. This violation refers to a driver operating a CMV as defined under § 383.5. 9. § 387.7(a... unqualified driver Single occurrence. This violation refers to a driver operating a CMV as defined under § 390...

CPLOAS_2 User Manual.

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

Sallaberry, Cedric Jean-Marie; Helton, Jon C.

2015-05-01

Weak link (WL)/strong link (SL) systems are important parts of the overall operational design of high - consequence systems. In such designs, the SL system is very robust and is intended to permit operation of the entire system under, and only under, intended conditions. In contrast, the WL system is intended to fail in a predictable and irreversible manner under accident conditions and render the entire system inoperable before an accidental operation of the SL system. The likelihood that the WL system will fail to d eactivate the entire system before the SL system fails (i.e., degrades into a configurationmore » that could allow an accidental operation of the entire system) is referred to as probability of loss of assured safety (PLOAS). This report describes the Fortran 90 program CPLOAS_2 that implements the following representations for PLOAS for situations in which both link physical properties and link failure properties are time - dependent: (i) failure of all SLs before failure of any WL, (ii) failure of any SL before f ailure of any WL, (iii) failure of all SLs before failure of all WLs, and (iv) failure of any SL before failure of all WLs. The effects of aleatory uncertainty and epistemic uncertainty in the definition and numerical evaluation of PLOAS can be included in the calculations performed by CPLOAS_2. Keywords: Aleatory uncertainty, CPLOAS_2, Epistemic uncertainty, Probability of loss of assured safety, Strong link, Uncertainty analysis, Weak link« less

Can natural variability trigger effects on fish and fish habitat as defined in environment Canada's metal mining environmental effects monitoring program?

PubMed

Mackey, Robin; Rees, Cassandra; Wells, Kelly; Pham, Samantha; England, Kent

2013-01-01

The Metal Mining Effluent Regulations (MMER) took effect in 2002 and require most metal mining operations in Canada to complete environmental effects monitoring (EEM) programs. An "effect" under the MMER EEM program is considered any positive or negative statistically significant difference in fish population, fish usability, or benthic invertebrate community EEM-defined endpoints. Two consecutive studies with the same statistically significant differences trigger more intensive monitoring, including the characterization of extent and magnitude and investigation of cause. Standard EEM study designs do not require multiple reference areas or preexposure sampling, thus results and conclusions about mine effects are highly contingent on the selection of a near perfect reference area and are at risk of falsely labeling natural variation as mine related "effects." A case study was completed to characterize the natural variability in EEM-defined endpoints during preexposure or baseline conditions. This involved completing a typical EEM study in future reference and exposure lakes surrounding a proposed uranium (U) mine in northern Saskatchewan, Canada. Moon Lake was sampled as the future exposure area as it is currently proposed to receive effluent from the U mine. Two reference areas were used: Slush Lake for both the fish population and benthic invertebrate community surveys and Lake C as a second reference area for the benthic invertebrate community survey. Moon Lake, Slush Lake, and Lake C are located in the same drainage basin in close proximity to one another. All 3 lakes contained similar water quality, fish communities, aquatic habitat, and a sediment composition largely comprised of fine-textured particles. The fish population survey consisted of a nonlethal northern pike (Esox lucius) and a lethal yellow perch (Perca flavescens) survey. A comparison of the 5 benthic invertebrate community effect endpoints, 4 nonlethal northern pike population effect endpoints, and 10 lethal yellow perch effect endpoints resulted in the observation of several statistically significant differences at the future exposure area relative to the reference area and/or areas. When the data from 2 reference areas assessed for the benthic invertebrate community survey were pooled, no significant differences in effect endpoints were observed. These results demonstrate weaknesses in the definition of an "effect" used by the MMER EEM program and in the use of a single reference area. Determination of the ecological significance of statistical differences identified as part of EEM programs conducted during the operational period should consider preexisting (background) natural variability between reference and exposure areas. Copyright © 2012 SETAC.

Measurements of Heat Flux Differences Within a Large Wind Farm During the 2013 Crop/Wind-Energy Experiment (CWEX-13)

NASA Astrophysics Data System (ADS)

Rajewski, D. A.

2015-12-01

Wind farms are an important resource for electrical generation in the Central U.S., however with each installation there are many poorly documented interactions with the local and surrounding environment. The impact of wind farms on surface microclimate is largely understood conceptually using numerical or wind tunnel models or ex situ satellite-detected changes. Measurements suitable for calibration of numerical simulations are few and of limited applicability but are urgently needed to improve parameterization of wind farm aerodynamics influenced by the diurnal evolution of the boundary layer. Among large eddy simulations of wind farm wakes in thermally stable stratification, there are discrepancies on the influence of turbine-induced mixing on the surface heat flux. We provide measurements from seven surface flux stations, vertical profiling LiDARs located upwind and downwind of turbines, and SCADA measurements from turbines during the 2013 Crop Wind Energy Experiment (CWEX-13) as the best evidence for the variability of turbine induced heat flux within a large wind farm. Examination of ambient conditions (wind direction, wind veer, and thermal stratification) and on turbine operation factors (hub-height wind speed, normalized power) reveal conditions that lead to the largest modification of heat flux. Our results demonstrate the highest flux change from the reference station to be where the leading few lines of turbines influence the surface. Under stably stratified conditions turbine-scale turbulence is highly efficient at bringing warmer air aloft to the surface, leading to an increase in downward heat flux. Conversely we see that the combination of wakes from several lines of turbines reduces the flux contrast from the reference station. In this regime of deep wind-farm flow, wake turbulence is similar in scale and intensity to the reference conditions. These analysis tools can be extended to other turbine SCADA and microclimate variables (e.g. temperature) to improve basic understanding of turbine-turbine and total wind farm wake interactions. Forthcoming tall-tower measurements will provide additional opportunities for comparison of simulated wind and thermal profiles in non-wake, and waked flow conditions.

Land-Use History and Contemporary Management Inform an Ecological Reference Model for Longleaf Pine Woodland Understory Plant Communities.

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

Brudvig, Lars A.; Orrock, John L.; Damschen, Ellen I.

Ecological restoration is frequently guided by reference conditions describing a successfully restored ecosystem; however, the causes and magnitude of ecosystem degradation vary, making simple knowledge of reference conditions insufficient for prioritizing and guiding restoration. Ecological reference models provide further guidance by quantifying reference conditions, as well as conditions at degraded states that deviate from reference conditions. Many reference models remain qualitative, however, limiting their utility. We quantified and evaluated a reference model for southeastern U.S. longleaf pine woodland understory plant communities. We used regression trees to classify 232 longleaf pine woodland sites at three locations along the Atlantic coastal plainmore » based on relationships between understory plant community composition, soils lol(which broadly structure these communities), and factors associated with understory degradation, including fire frequency, agricultural history, and tree basal area. To understand the spatial generality of this model, we classified all sites together. and for each of three study locations separately. Both the regional and location-specific models produced quantifiable degradation gradients–i.e., progressive deviation from conditions at 38 reference sites, based on understory species composition, diversity and total cover, litter depth, and other attributes. Regionally, fire suppression was the most important degrading factor, followed by agricultural history, but at individual locations, agricultural history or tree basal area was most important. At one location, the influence of a degrading factor depended on soil attributes. We suggest that our regional model can help prioritize longleaf pine woodland restoration across our study region; however, due to substantial landscape-to-landscape variation, local management decisions should take into account additional factors (e.g., soil attributes). Our study demonstrates the utility of quantifying degraded states and provides a series of hypotheses for future experimental restoration work. More broadly, our work provides a framework for developing and evaluating reference models that incorporate multiple, interactive anthropogenic drivers of ecosystem degradation.« less

On the quantum Landau collision operator and electron collisions in dense plasmas

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

Daligault, Jérôme, E-mail: daligaul@lanl.gov

2016-03-15

The quantum Landau collision operator, which extends the widely used Landau/Fokker-Planck collision operator to include quantum statistical effects, is discussed. The quantum extension can serve as a reference model for including electron collisions in non-equilibrium dense plasmas, in which the quantum nature of electrons cannot be neglected. In this paper, the properties of the Landau collision operator that have been useful in traditional plasma kinetic theory and plasma transport theory are extended to the quantum case. We outline basic properties in connection with the conservation laws, the H-theorem, and the global and local equilibrium distributions. We discuss the Fokker-Planck formmore » of the operator in terms of three potentials that extend the usual two Rosenbluth potentials. We establish practical closed-form expressions for these potentials under local thermal equilibrium conditions in terms of Fermi-Dirac and Bose-Einstein integrals. We study the properties of linearized quantum Landau operator, and extend two popular approximations used in plasma physics to include collisions in kinetic simulations. We apply the quantum Landau operator to the classic test-particle problem to illustrate the physical effects embodied in the quantum extension. We present useful closed-form expressions for the electron-ion momentum and energy transfer rates. Throughout the paper, similarities and differences between the quantum and classical Landau collision operators are emphasized.« less

On the quantum Landau collision operator and electron collisions in dense plasmas

NASA Astrophysics Data System (ADS)

Daligault, Jérôme

2016-03-01

The quantum Landau collision operator, which extends the widely used Landau/Fokker-Planck collision operator to include quantum statistical effects, is discussed. The quantum extension can serve as a reference model for including electron collisions in non-equilibrium dense plasmas, in which the quantum nature of electrons cannot be neglected. In this paper, the properties of the Landau collision operator that have been useful in traditional plasma kinetic theory and plasma transport theory are extended to the quantum case. We outline basic properties in connection with the conservation laws, the H-theorem, and the global and local equilibrium distributions. We discuss the Fokker-Planck form of the operator in terms of three potentials that extend the usual two Rosenbluth potentials. We establish practical closed-form expressions for these potentials under local thermal equilibrium conditions in terms of Fermi-Dirac and Bose-Einstein integrals. We study the properties of linearized quantum Landau operator, and extend two popular approximations used in plasma physics to include collisions in kinetic simulations. We apply the quantum Landau operator to the classic test-particle problem to illustrate the physical effects embodied in the quantum extension. We present useful closed-form expressions for the electron-ion momentum and energy transfer rates. Throughout the paper, similarities and differences between the quantum and classical Landau collision operators are emphasized.

46 CFR 109.105 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Incorporation by reference. 109.105 Section 109.105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS General § 109.105 Incorporation by reference. (a) Certain material is incorporated by reference...

46 CFR 109.105 - Incorporation by reference.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Incorporation by reference. 109.105 Section 109.105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS General § 109.105 Incorporation by reference. (a) Certain material is incorporated by reference...

46 CFR 109.105 - Incorporation by reference.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Incorporation by reference. 109.105 Section 109.105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS General § 109.105 Incorporation by reference. (a) Certain material is incorporated by reference...

46 CFR 109.105 - Incorporation by reference.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Incorporation by reference. 109.105 Section 109.105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS General § 109.105 Incorporation by reference. (a) Certain material is incorporated by reference...

46 CFR 109.105 - Incorporation by reference.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Incorporation by reference. 109.105 Section 109.105 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS General § 109.105 Incorporation by reference. (a) Certain material is incorporated by reference...

Methods, systems and apparatus for controlling third harmonic voltage when operating a multi-space machine in an overmodulation region

DOEpatents

Perisic, Milun; Kinoshita, Michael H; Ranson, Ray M; Gallegos-Lopez, Gabriel

2014-06-03

Methods, system and apparatus are provided for controlling third harmonic voltages when operating a multi-phase machine in an overmodulation region. The multi-phase machine can be, for example, a five-phase machine in a vector controlled motor drive system that includes a five-phase PWM controlled inverter module that drives the five-phase machine. Techniques for overmodulating a reference voltage vector are provided. For example, when the reference voltage vector is determined to be within the overmodulation region, an angle of the reference voltage vector can be modified to generate a reference voltage overmodulation control angle, and a magnitude of the reference voltage vector can be modified, based on the reference voltage overmodulation control angle, to generate a modified magnitude of the reference voltage vector. By modifying the reference voltage vector, voltage command signals that control a five-phase inverter module can be optimized to increase output voltages generated by the five-phase inverter module.

Irrigation Training Manual. Planning, Design, Operation, and Management of Small-Scale Irrigation Systems [and] Irrigation Reference Manual. A Technical Reference to Be Used with the Peace Corps Irrigation Training Manual T0076 in the Selection, Planning, Design, Operation, and Management of Small-Scale Irrigation Systems.

ERIC Educational Resources Information Center

Salazar, LeRoy; And Others

This resource for trainers involved in irrigated agriculture training for Peace Corps volunteers consists of two parts: irrigation training manual and irrigation reference manual. The complete course should fully prepare volunteers serving as irrigation, specialists to plan, implement, evaluate and manage small-scale irrigation projects in arid,…

Coherent Frequency Reference System for the NASA Deep Space Network

NASA Technical Reports Server (NTRS)

Tucker, Blake C.; Lauf, John E.; Hamell, Robert L.; Gonzaler, Jorge, Jr.; Diener, William A.; Tjoelker, Robert L.

2010-01-01

The NASA Deep Space Network (DSN) requires state-of-the-art frequency references that are derived and distributed from very stable atomic frequency standards. A new Frequency Reference System (FRS) and Frequency Reference Distribution System (FRD) have been developed, which together replace the previous Coherent Reference Generator System (CRG). The FRS and FRD each provide new capabilities that significantly improve operability and reliability. The FRS allows for selection and switching between frequency standards, a flywheel capability (to avoid interruptions when switching frequency standards), and a frequency synthesis system (to generate standardized 5-, 10-, and 100-MHz reference signals). The FRS is powered by redundant, specially filtered, and sustainable power systems and includes a monitor and control capability for station operations to interact and control the frequency-standard selection process. The FRD receives the standardized 5-, 10-, and 100-MHz reference signals and distributes signals to distribution amplifiers in a fan out fashion to dozens of DSN users that require the highly stable reference signals. The FRD is also powered by redundant, specially filtered, and sustainable power systems. The new DSN Frequency Distribution System, which consists of the FRS and FRD systems described here, is central to all operational activities of the NASA DSN. The frequency generation and distribution system provides ultra-stable, coherent, and very low phase-noise references at 5, l0, and 100 MHz to between 60 and 100 separate users at each Deep Space Communications Complex.

Diagnosis of Bubonic Plague by PCR in Madagascar under Field Conditions

PubMed Central

Rahalison, L.; Vololonirina, E.; Ratsitorahina, M.; Chanteau, S.

2000-01-01

The diagnostic value of a PCR assay that amplifies a 501-bp fragment of the Yersinia pestis caf1 gene has been determined in a reference laboratory with 218 bubo aspirates collected from patients with clinically suspected plague managed in a regional hospital in Madagascar. The culture of Y. pestis and the detection of the F1 antigen (Ag) by enzyme-linked immunosorbent assay (ELISA) were used as reference diagnostic methods. The sensitivity of PCR was 89% (57 of 64) for the Y. pestis-positive patients, and 80.7% (63 of 78) for the F1 Ag-positive patients. The specificity of PCR for the culture-, F1 Ag-, and antibody-negative patients (n = 105) was 100%. Because in Madagascar most patients with plague are managed and their clinical samples are collected in remote villages, the usefulness of PCR was evaluated for routine diagnostic use in the operational conditions of the control program. The sensitivity of PCR was 50% (25 of 50) relative to the results of culture and 35.2% (19 of 54) relative to the results of the F1 Ag immunocapture ELISA. The specificity of PCR under these conditions was 96%. In conclusion, the PCR method was found to be very specific but not as sensitive as culture or the F1 Ag detection method. The limitation in sensitivity may have been due to suboptimal field conditions and the small volumes of samples used for DNA extraction. This technique is not recommended as a routine diagnostic test for plague in Madagascar. PMID:10618097

Isokinetic TWC Evaporator Probe: Development of the IKP2 and Performance Testing for the HAIC-HIWC Darwin 2014 and Cayenne-2015 Field Campaigns

NASA Technical Reports Server (NTRS)

Strapp, John W.; Lilie, Lyle E.; Ratvasky, Thomas P.; Davison, Craig R.; Dumont, Christopher J.

2016-01-01

A new Isokinetic Total Water Content Evaporator (IKP2) was downsized from a prototype instrument, specifically to make airborne measurements of hydrometeor total water content (TWC) in deep tropical convective clouds to assess the new ice crystal Appendix D icing envelope. The probe underwent numerous laboratory and wind tunnel investigations to ensure reliable operation under the difficult high altitude/speed/TWC conditions under which other TWC instruments have been known to either fail, or have unknown performance characteristics. The article tracks the testing and modifications of the IKP2 probe to ensure its readiness for three flight campaigns in 2014 and 2015. Comparisons are made between the IKP2 and the NASA Icing Research Tunnel reference values in liquid conditions, and to an exploratory technique estimating ice water content from a bulk ice capture cylinder method in glaciated conditions. These comparisons suggest that the initial target of 20 percent accuracy in TWC has been achieved and likely exceeded for tested TWC values in excess of about 0.5 gm (exp -3). Uncertainties in the ice water content reference method have been identified. Complications are introduced in the necessary subtraction of an independently measured background water vapour concentration, errors of which are small at the colder flight temperatures, but increase rapidly with increasing temperature, and ultimately limit the practical use of the instrument in a tropical convective atmosphere to conditions colder than about 0 degrees C. A companion article in this conference traces the accuracy of the components of the IKP2 to derive estimated system accuracy.

Isokinetic TWC Evaporator Probe: Development of the IKP2 and Performance Testing for the HAIC-HIWC Darwin 2014 and Cayenne 2015 Field Campaigns

NASA Technical Reports Server (NTRS)

Strapp, J. Walter; Lilie, Lyle E.; Ratvasky, Thomas P.; Davison, Craig; Dumont, Chris

2016-01-01

A new Isokinetic Total Water Content Evaporator (IKP2) was downsized from a prototype instrument, specifically to make airborne measurements of hydrometeor total water content (TWC) in deep tropical convective clouds to assess the new ice crystal Appendix D icing envelope. The probe underwent numerous laboratory and wind tunnel investigations to ensure reliable operation under the difficult high altitude/speed/TWC conditions under which other TWC instruments have been known to either fail, or have unknown performance characteristics. The article tracks the testing and modifications of the IKP2 probe to ensure its readiness for three flight campaigns in 2014 and 2015. Comparisons are made between the IKP2 and the NASA Icing Research Tunnel reference values in liquid conditions, and to an exploratory technique estimating ice water content from a bulk ice capture cylinder method in glaciated conditions. These comparisons suggest that the initial target of 20% accuracy in TWC has been achieved and likely exceeded for tested TWC values in excess of about 0.5/cu gm. Uncertainties in the ice water content reference method have been identified. Complications are introduced in the necessary subtraction of an independently measured background water vapor concentration, errors of which are small at the colder flight temperatures, but increase rapidly with increasing temperature, and ultimately limit the practical use of the instrument in a tropical convective atmosphere to conditions colder than about 0 C. A companion article in this conference traces the accuracy of the components of the IKP2 to derive estimated system accuracy.

Effect of alcohol references in music on alcohol consumption in public drinking places.

PubMed

Engels, Rutger C M E; Slettenhaar, Gert; ter Bogt, Tom; Scholte, Ron H J

2011-01-01

People are exposed to many references to alcohol, which might influence their consumption of alcohol directly. In a field experiment, we tested whether textual references to alcohol in music played in bars lead to higher revenues of alcoholic beverages. We created two databases: one contained songs referring to alcohol, the parallel database contained songs with matching artists, tempo, and energetic content, but no references to alcohol. Customers of three bars were exposed to either music textually referring to alcohol or to the control condition, resulting in 23 evenings in both conditions. Bartenders were instructed to play songs with references to alcohol (or not) during a period of 2 hours each of the evenings of interest. They were not blind to the experimental condition. The results showed that customers who were exposed to music with textual references to alcohol spent significantly more on alcoholic drinks compared to customers in the control condition. This pilot study provides preliminary evidence that alcohol-related lyrics directly affect alcohol consumption in public drinking places. Since our study is one of the first testing direct effects of music lyrics on consumption, our small-scale, preliminary study needs replication before firm conclusions can be drawn. Copyright © American Academy of Addiction Psychiatry.

The scopolamine-reversal paradigm in rats and monkeys: the importance of computer-assisted operant-conditioning memory tasks for screening drug candidates.

PubMed

Buccafusco, Jerry J; Terry, Alvin V; Webster, Scott J; Martin, Daniel; Hohnadel, Elizabeth J; Bouchard, Kristy A; Warner, Samantha E

2008-08-01

The scopolamine-reversal model is enjoying a resurgence of interest in clinical studies as a reversible pharmacological model for Alzheimer's disease (AD). The cognitive impairment associated with scopolamine is similar to that in AD. The scopolamine model is not simply a cholinergic model, as it can be reversed by drugs that are noncholinergic cognition-enhancing agents. The objective of the study was to determine relevance of computer-assisted operant-conditioning tasks in the scopolamine-reversal model in rats and monkeys. Rats were evaluated for their acquisition of a spatial reference memory task in the Morris water maze. A separate cohort was proficient in performance of an automated delayed stimulus discrimination task (DSDT). Rhesus monkeys were proficient in the performance of an automated delayed matching-to-sample task (DMTS). The AD drug donepezil was evaluated for its ability to reverse the decrements in accuracy induced by scopolamine administration in all three tasks. In the DSDT and DMTS tasks, the effects of donepezil were delay (retention interval)-dependent, affecting primarily short delay trials. Donepezil produced significant but partial reversals of the scopolamine-induced impairment in task accuracies after 2 mg/kg in the water maze, after 1 mg/kg in the DSDT, and after 50 microg/kg in the DMTS task. The two operant-conditioning tasks (DSDT and DMTS) provided data most in keeping with those reported in clinical studies with these drugs. The model applied to nonhuman primates provides an excellent transitional model for new cognition-enhancing drugs before clinical trials.

An Universal packaging technique for low-drift implantable pressure sensors.

PubMed

Kim, Albert; Powell, Charles R; Ziaie, Babak

2016-04-01

Monitoring bodily pressures provide valuable diagnostic and prognostic information. In particular, long-term measurement through implantable sensors is highly desirable in situations where percutaneous access can be complicated or dangerous (e.g., intracranial pressure in hydrocephalic patients). In spite of decades of progress in the fabrication of miniature solid-state pressure sensors, sensor drift has so far severely limited their application in implantable systems. In this paper, we report on a universal packaging technique for reducing the sensor drift. The described method isolates the pressure sensor from a major source of drift, i.e., contact with the aqueous surrounding environment, by encasing the sensor in a silicone-filled medical-grade polyurethane balloon. In-vitro soak tests for 100 days using commercial micromachined piezoresistive pressure sensors demonstrate a stable operation with the output remaining within 1.8 cmH2O (1.3 mmHg) of a reference pressure transducer. Under similar test conditions, a non-isolated sensor fluctuates between 10 and 20 cmH2O (7.4-14.7 mmHg) of the reference, without ever settling to a stable operation regime. Implantation in Ossabow pigs demonstrate the robustness of the package and its in-vivo efficacy in reducing the baseline drift.

Aircraft Design Considerations to Meet One Engine Inoperative (OEI) Safety Requirements

NASA Technical Reports Server (NTRS)

Scott, Mark W.

2012-01-01

Commercial airlines are obligated to operate such that an aircraft can suffer an engine failure at any point in its mission and terminate the flight without an accident. Only minimal aircraft damage is allowable, such as brake replacement due to very heavy application, or an engine inspection and/or possible removal due to use of an emergency rating. Such performance criteria are often referred to as zero exposure, referring to zero accident exposure to an engine failure. The critical mission segment for meeting one engine inoperative (OEI) criteria is takeoff. For a given weight, wind, and ambient condition, fixed wing aircraft require a balanced field length. This is the longer of the distance to take off if an engine fails at a predetermined critical point in the takeoff profile, or the distance to reject the takeoff and brake to a stop. Rotorcraft have requirements for horizontal takeoff procedures that are equivalent to a balanced field length requirements for fixed wing aircraft. Rotorcraft also perform vertical procedures where no runway or heliport distance is available. These were developed primarily for elevated heliports as found on oil rigs or rooftops. They are also used for ground level operations as might be found at heliports at the end of piers or other confined areas.

Identification of a novel reference gene for apple transcriptional profiling under postharvest conditions.

PubMed

Storch, Tatiane Timm; Pegoraro, Camila; Finatto, Taciane; Quecini, Vera; Rombaldi, Cesar Valmor; Girardi, César Luis

2015-01-01

Reverse Transcription quantitative PCR (RT-qPCR) is one of the most important techniques for gene expression profiling due to its high sensibility and reproducibility. However, the reliability of the results is highly dependent on data normalization, performed by comparisons between the expression profiles of the genes of interest against those of constitutively expressed, reference genes. Although the technique is widely used in fruit postharvest experiments, the transcription stability of reference genes has not been thoroughly investigated under these experimental conditions. Thus, we have determined the transcriptional profile, under these conditions, of three genes commonly used as reference--ACTIN (MdACT), PROTEIN DISULPHIDE ISOMERASE (MdPDI) and UBIQUITIN-CONJUGATING ENZYME E2 (MdUBC)--along with two novel candidates--HISTONE 1 (MdH1) and NUCLEOSSOME ASSEMBLY 1 PROTEIN (MdNAP1). The expression profile of the genes was investigated throughout five experiments, with three of them encompassing the postharvest period and the other two, consisting of developmental and spatial phases. The transcriptional stability was comparatively investigated using four distinct software packages: BestKeeper, NormFinder, geNorm and DataAssist. Gene ranking results for transcriptional stability were similar for the investigated software packages, with the exception of BestKeeper. The classic reference gene MdUBC ranked among the most stably transcribed in all investigated experimental conditions. Transcript accumulation profiles for the novel reference candidate gene MdH1 were stable throughout the tested conditions, especially in experiments encompassing the postharvest period. Thus, our results present a novel reference gene for postharvest experiments in apple and reinforce the importance of checking the transcription profile of reference genes under the experimental conditions of interest.

Application of automation and robotics to lunar surface human exploration operations

NASA Technical Reports Server (NTRS)

Woodcock, Gordon R.; Sherwood, Brent; Buddington, Patricia A.; Bares, Leona C.; Folsom, Rolfe; Mah, Robert; Lousma, Jack

1990-01-01

Major results of a study applying automation and robotics to lunar surface base buildup and operations concepts are reported. The study developed a reference base scenario with specific goals, equipment concepts, robot concepts, activity schedules and buildup manifests. It examined crew roles, contingency cases and system reliability, and proposed a set of technologies appropriate and necessary for effective lunar operations. This paper refers readers to four companion papers for quantitative details where appropriate.

Separation of nitrogen heterocyclic compounds from model coal tar fraction by solvent extraction

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

Kim, S.J.; Chun, Y.J.

2005-07-01

The separation of four kinds of nitrogen heterocyclic compounds (NHCs) from a model mixture comprising NHCs (indole (In), quinoline (Q), iso-quinoline (iQ), quinaldine (Qu)), three kinds of bicyclic aromatic compounds (BACs; 1-methyl-naphthalene (IMN), 2-methyl naphthalene (2MN), dimethylnaphthalene (DMN)), biphenyl (Bp) and phenyl ether (Pe) was examined by a solvent extraction. The model mixture used as a raw material of this work was prepared according to the components and compositions contained in coal tar fraction (the temperature ranges of fraction: 240-265{sup o}C). An aqueous solution of methanol, ethanol, iso-propyl alcohol, N,N-dimethyl acetamide, DMF, formamide, N-methylformamide/methanol, and formamide/methanol were used as solvents.more » An aqueous solution of formamide was found suitable for separating NHCs contained in coal tar fraction based on distribution coefficient and selectivity. The effect of operation factors on separating NHCs was investigated by the distribution equilibrium using an aqueous solution of formamide. Increasing the operation temperature and the volume ratio of solvent to feed at initial (S/F)(o) resulted in improving the distribution coefficients of each NHC, but increasing the volume fraction of water in the solvent at initial (y(w,O)) resulted in deteriorating the distribution coefficients of each NHC. With increasing y(w,O) and (S/F)(o), the selectivities of each NHC in reference to DMN increased. Increase in operation temperature resulted in decrease in selectivities of each NHC in reference to DMN. At an experimental condition fixed, the sequence of the distribution coefficient and selectivity in reference to DMN for each NHC was In {gt} iQ {gt} Q {gt} Qu, and also the sequence of the distribution coefficient for each BAC was IMN {gt} 2MN {gt} DMN. The sequence of the distribution coefficient for entire compounds analyzed by this work was In {gt} iQ {gt} Q {gt} Qu {gt} BP {gt} 1MN {gt} 2MN {gt} Pe {gt} DMN.« less

Silver-silver sulfate reference electrodes for use in lead-acid batteries

NASA Astrophysics Data System (ADS)

Ruetschi, Paul

Electrochemical properties of silver-silver sulfate reference electrodes for lead-acid batteries are described, and the following possible applications discussed: Determination of individual capacities of positive and negative plates. Monitoring individual electrode behavior during deep discharge and cell reversal. Optimization charge or discharge parameters, by controlling the current such that pre-determined limits of positive or negative half-cell potential are respected. Observation of acid concentration differences, for example due to acid stratification, by measuring diffusion potentials (concentration-cell voltages). Detection of defective cells, and defective plate sets, in a string of cells, at the end of their service life. Silver-silver sulfate reference electrodes, permanently installed in lead-acid cells, may be a means to improve battery management, and therewith to improve reliability and service life. In vented batteries, reference electrodes may be used to limit positive plate polarization during charge, or float-charge. Limiting the positive half-cell potential to an upper, pre-set value would permit to keep anodic corrosion as low as possible. During cycling, discharge could be terminated when the half-cell potential of the positive electrode has dropped to a pre-set limit. This would prevent excessive discharge of the positive electrodes, which could result in an improvement of cycle life. In valve-regulated batteries, reference electrodes may be used to adjust float-charge conditions such as to assure sufficient cathodic polarization of the negative electrodes, in order to avoid sulfation. The use of such reference electrodes could be beneficial particularly in multi-cell batteries, with overall voltages above 12 V, operated in a partial-state-of-charge.

Determining water and nitrogen balances for beneficial management practices using lysimeters at Wagna test site (Austria).

PubMed

Klammler, Gernot; Fank, Johann

2014-11-15

The shallow Murtal aquifer south of Graz, Austria, provides easily withdrawable groundwater, which is supplied as drinking water without any chemical treatment. The aquifer is also used intensively by agriculture. Common agricultural management practices are the main source for diffuse nitrogen leaching and high groundwater nitrate concentrations. To safeguard the coexisting use of these two important resources, lysimeters are operated at the agricultural test site Wagna, Austria, and the influence of two beneficial management practices--low nitrogen input and organic farming--on nitrogen leaching towards groundwater is investigated. The technical lysimeter design as presented here consists of: (1) high-resolution weighing cells, (2) a suction controlled lower boundary condition for sucking off seepage water, thus emulating undisturbed field conditions, (3) comparative soil temperature, water content and matrix potential measurements inside and outside the lysimeter at different depths, (4) an installation of the lysimeters directly into test plots and (5) a removable upper lysimeter ring enabling machinery soil tillage. Our results indicate that oasis effects or fringe effects of the lysimeter cylinder on unsaturated water flow did not occur. Another lysimeter cultivated with lawn is operated for observing grass-reference evapotranspiration, which resulted in good agreement with calculated grass-reference evapotranspiration according to the FAO-Penman-Monteith method. We conclude that lysimeters installed at Wagna test site did not show any fringe effects and, thus, are appropriate tools for measuring water balance elements and nitrogen leaching of arable and grass land at point scale. Furthermore, our results for the period of 2005 to 2011 show that beneficial management practices reduced nitrate leaching and, hence, may allow for a sustainable coexistence of drinking water supply and agriculture in the Murtal aquifer. Copyright © 2014 Elsevier B.V. All rights reserved.

Characterization of a microDiamond detector in high-dose-per-pulse electron beams for intra operative radiation therapy.

PubMed

Di Venanzio, C; Marinelli, Marco; Tonnetti, A; Verona-Rinati, G; Falco, M D; Pimpinella, M; Ciccotelli, A; De Stefano, S; Felici, G; Marangoni, F

2015-12-01

To characterize a synthetic diamond dosimeter (PTW Freiburg microDiamond 60019) in high dose-per-pulse electron beams produced by an Intra Operative Radiation Therapy (IORT) dedicated accelerator. The dosimetric properties of the microDiamond were assessed under 6, 8 and 9 MeV electron beams by a NOVAC11 mobile accelerator (Sordina IORT Technologies S.p.A.). The characterization was carried out with dose-per-pulse ranging from 26 to 105 mGy per pulse. The microDiamond performance was compared with an Advanced Markus ionization chamber and a PTW silicon diode E in terms of dose linearity, percentage depth dose (PDD) curves, beam profiles and output factors. A good linearity of the microDiamond response was verified in the dose range from 0.2 Gy to 28 Gy. A sensitivity of 1.29 nC/Gy was measured under IORT electron beams, resulting within 1% with respect to the one obtained in reference condition under (60)Co gamma irradiation. PDD measurements were found in agreement with the ones by the reference dosimeters, with differences in R50 values below 0.3 mm. Profile measurements evidenced a high spatial resolution of the microDiamond, slightly worse than the one of the silicon diode. The penumbra widths measured by the microDiamond resulted approximately 0.5 mm larger than the ones by the Silicon diode. Output factors measured by the microDiamond were found within 2% with those obtained by the Advanced Markus down to 3 cm diameter field sizes. The microDiamond dosimeter was demonstrated to be suitable for precise dosimetry in IORT applications under high dose-per-pulse conditions. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Design and implementation of adaptive PI control schemes for web tension control in roll-to-roll (R2R) manufacturing.

PubMed

Raul, Pramod R; Pagilla, Prabhakar R

2015-05-01

In this paper, two adaptive Proportional-Integral (PI) control schemes are designed and discussed for control of web tension in Roll-to-Roll (R2R) manufacturing systems. R2R systems are used to transport continuous materials (called webs) on rollers from the unwind roll to the rewind roll. Maintaining web tension at the desired value is critical to many R2R processes such as printing, coating, lamination, etc. Existing fixed gain PI tension control schemes currently used in industrial practice require extensive tuning and do not provide the desired performance for changing operating conditions and material properties. The first adaptive PI scheme utilizes the model reference approach where the controller gains are estimated based on matching of the actual closed-loop tension control systems with an appropriately chosen reference model. The second adaptive PI scheme utilizes the indirect adaptive control approach together with relay feedback technique to automatically initialize the adaptive PI gains. These adaptive tension control schemes can be implemented on any R2R manufacturing system. The key features of the two adaptive schemes is that their designs are simple for practicing engineers, easy to implement in real-time, and automate the tuning process. Extensive experiments are conducted on a large experimental R2R machine which mimics many features of an industrial R2R machine. These experiments include trials with two different polymer webs and a variety of operating conditions. Implementation guidelines are provided for both adaptive schemes. Experimental results comparing the two adaptive schemes and a fixed gain PI tension control scheme used in industrial practice are provided and discussed. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Post-aerocapture orbit selection and maintenance for the Aerofast mission to Mars

NASA Astrophysics Data System (ADS)

Pontani, Mauro; Teofilatto, Paolo

2012-10-01

Aerofast is the abbreviation of “aerocapture for future space transportation” and represents a project aimed at developing aerocapture techniques with regard to an interplanetary mission to Mars, in the context of the 7th Framework Program, with the financial support of the European Union. This paper describes the fundamental characteristics of the operational orbit after aerocapture for the mission of interest, as well as the related maintenance strategy. The final orbit selection depends on the desired lighting conditions, maximum revisit time of specific target regions, and feasibility of the orbit maintenance strategy. A sunsynchronous, frozen, repeating-ground-track orbit is chosen. First, the period of repetition is such that adjacent ascending node crossings (over the Mars surface) have a separation compatible with the swath of the optical payload. Secondly, the sunsynchronism condition ensures that a given latitude is periodically visited at the same local time, which condition is essential for comparing images of the same region at different epochs. Lastly, the fulfillment of the frozen condition guarantees improved orbit stability with respect to perturbations due to the zonal harmonics of Mars gravitational field. These three fundamental features of the operational orbit lead to determining its mean orbital elements. The evaluation of short and long period effects (e.g., those due to the sectorial harmonics of the gravitational field or to the aerodynamic drag) requires the determination of the osculating orbital elements at an initial reference time. This research describes a simple and accurate approach that leads to numerically determining these initial values, without employing complicated analytical developments. Numerical simulations demonstrate the long-period stability of the orbit when a significant number of harmonics of the gravitational field are taken into account. However, aerodynamic drag produces a relatively slow orbital decay at the altitudes considered for the mission. This circumstance implies the progressive loss of the sunsynchronism condition, and therefore corrective maneuvers are to be performed. This work proves that actually only in-plane maneuvers are necessary, evaluates the overall delta-v budget needed in the period of repetition (85 Martian nodal days), and proposes a simple maintenance strategy, making reference to the worst-case scenario, which corresponds to the highest seasonal values of the atmospheric density and to the maximum value of the ballistic coefficient of the spacecraft.

Development of a Converter-Based Transmission Line Emulator with Three-Phase Short-Circuit Fault Emulation Capability

DOE PAGES

Zhang, Shuoting; Liu, Bo; Zheng, Sheng; ...

2018-01-01

A transmission line emulator has been developed to flexibly represent interconnected ac lines under normal operating conditions in a voltage source converter (VSC)-based power system emulation platform. As the most serious short-circuit fault condition, the three-phase short-circuit fault emulation is essential for power system studies. Here, this paper proposes a model to realize a three-phase short-circuit fault emulation at different locations along a single transmission line or one of several parallel-connected transmission lines. At the same time, a combination method is proposed to eliminate the undesired transients caused by the current reference step changes while switching between the fault statemore » and the normal state. Experiment results verify the developed transmission line three-phase short-circuit fault emulation capability.« less

Evaluation of Low-Tech Indoor Remediation Methods ...

EPA Pesticide Factsheets

Report This study identified, collected, evaluated, and summarized available articles, reports, guidance documents, and other pertinent information related to common housekeeping activities within the United States. This resulted in a summary compendium including relevant information about multiple low-tech cleaning methods from the literature search results. Through discussion and prioritization, an EPA project team, made up of several EPA scientists and emergency responders, focused the information into a list of 14 housekeeping activities for decontamination evaluation testing. These types of activities are collectively referred to as “low-tech” remediation methods because of the comparative simple tools, equipment, and operations involved. Similarly, eight common household surfaces were chosen that were contaminated using three different contamination conditions. Thirty-three combinations of methods and surfaces were chosen for testing under the three contamination conditions for a total of 99 tests.

Development of a Converter-Based Transmission Line Emulator with Three-Phase Short-Circuit Fault Emulation Capability

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

Zhang, Shuoting; Liu, Bo; Zheng, Sheng

A transmission line emulator has been developed to flexibly represent interconnected ac lines under normal operating conditions in a voltage source converter (VSC)-based power system emulation platform. As the most serious short-circuit fault condition, the three-phase short-circuit fault emulation is essential for power system studies. Here, this paper proposes a model to realize a three-phase short-circuit fault emulation at different locations along a single transmission line or one of several parallel-connected transmission lines. At the same time, a combination method is proposed to eliminate the undesired transients caused by the current reference step changes while switching between the fault statemore » and the normal state. Experiment results verify the developed transmission line three-phase short-circuit fault emulation capability.« less

Premission and postmission simulation studies of the foot-controlled maneuvering unit for Skylab experiment T-020. [astronaut maneuvering equipment - space environment simulation

NASA Technical Reports Server (NTRS)

Hewes, D. E.; Glover, K. E.

1975-01-01

A Skylab experiment was conducted to study the maneuvering capabilities of astronauts using a relatively simple self-locomotive device, referred to as the foot-controlled maneuvering unit, and to evaluate the effectiveness of ground-based facilities simulating the operation of this device in weightless conditions of space. Some of the special considerations given in the definition and development of the experiment as related to the two ground-based simulators are reviewed. These simulators were used to train the test subjects and to obtain baseline data which could be used for comparison with the in-flight tests that were performed inside the Skylab orbital workshop. The results of both premission and postmission tests are discussed, and subjective comparisons of the in-flight and ground-based test conditions are presented.

Inertial Measures of Motion for Clinical Biomechanics: Comparative Assessment of Accuracy under Controlled Conditions - Effect of Velocity

PubMed Central

Lebel, Karina; Boissy, Patrick; Hamel, Mathieu; Duval, Christian

2013-01-01

Background Inertial measurement of motion with Attitude and Heading Reference Systems (AHRS) is emerging as an alternative to 3D motion capture systems in biomechanics. The objectives of this study are: 1) to describe the absolute and relative accuracy of multiple units of commercially available AHRS under various types of motion; and 2) to evaluate the effect of motion velocity on the accuracy of these measurements. Methods The criterion validity of accuracy was established under controlled conditions using an instrumented Gimbal table. AHRS modules were carefully attached to the center plate of the Gimbal table and put through experimental static and dynamic conditions. Static and absolute accuracy was assessed by comparing the AHRS orientation measurement to those obtained using an optical gold standard. Relative accuracy was assessed by measuring the variation in relative orientation between modules during trials. Findings Evaluated AHRS systems demonstrated good absolute static accuracy (mean error < 0.5o) and clinically acceptable absolute accuracy under condition of slow motions (mean error between 0.5o and 3.1o). In slow motions, relative accuracy varied from 2o to 7o depending on the type of AHRS and the type of rotation. Absolute and relative accuracy were significantly affected (p<0.05) by velocity during sustained motions. The extent of that effect varied across AHRS. Interpretation Absolute and relative accuracy of AHRS are affected by environmental magnetic perturbations and conditions of motions. Relative accuracy of AHRS is mostly affected by the ability of all modules to locate the same global reference coordinate system at all time. Conclusions Existing AHRS systems can be considered for use in clinical biomechanics under constrained conditions of use. While their individual capacity to track absolute motion is relatively consistent, the use of multiple AHRS modules to compute relative motion between rigid bodies needs to be optimized according to the conditions of operation. PMID:24260324

USING ABIOTIC INDICATORS OF REFERENCE CONDITION AND BIOTIC INDICATORS OF CONDITION TO ASSESS GREAT RIVER ECOSYSTEMS

EPA Science Inventory

This presentation outlines the approach and preliminary assessment results for EMAP-GRE. The use of biological indicators and reference conditions for river assessments has implications for scientists, river managers, and state and tribal natural resource regulators.

Identification of Reference Genes in Human Myelomonocytic Cells for Gene Expression Studies in Altered Gravity

PubMed Central

Thiel, Cora S.; Hauschild, Swantje; Tauber, Svantje; Paulsen, Katrin; Raig, Christiane; Raem, Arnold; Biskup, Josefine; Gutewort, Annett; Hürlimann, Eva; Philpot, Claudia; Lier, Hartwin; Engelmann, Frank; Layer, Liliana E.

2015-01-01

Gene expression studies are indispensable for investigation and elucidation of molecular mechanisms. For the process of normalization, reference genes (“housekeeping genes”) are essential to verify gene expression analysis. Thus, it is assumed that these reference genes demonstrate similar expression levels over all experimental conditions. However, common recommendations about reference genes were established during 1 g conditions and therefore their applicability in studies with altered gravity has not been demonstrated yet. The microarray technology is frequently used to generate expression profiles under defined conditions and to determine the relative difference in expression levels between two or more different states. In our study, we searched for potential reference genes with stable expression during different gravitational conditions (microgravity, normogravity, and hypergravity) which are additionally not altered in different hardware systems. We were able to identify eight genes (ALB, B4GALT6, GAPDH, HMBS, YWHAZ, ABCA5, ABCA9, and ABCC1) which demonstrated no altered gene expression levels in all tested conditions and therefore represent good candidates for the standardization of gene expression studies in altered gravity. PMID:25654098

Identification of reference genes in human myelomonocytic cells for gene expression studies in altered gravity.

PubMed

Thiel, Cora S; Hauschild, Swantje; Tauber, Svantje; Paulsen, Katrin; Raig, Christiane; Raem, Arnold; Biskup, Josefine; Gutewort, Annett; Hürlimann, Eva; Unverdorben, Felix; Buttron, Isabell; Lauber, Beatrice; Philpot, Claudia; Lier, Hartwin; Engelmann, Frank; Layer, Liliana E; Ullrich, Oliver

2015-01-01

Gene expression studies are indispensable for investigation and elucidation of molecular mechanisms. For the process of normalization, reference genes ("housekeeping genes") are essential to verify gene expression analysis. Thus, it is assumed that these reference genes demonstrate similar expression levels over all experimental conditions. However, common recommendations about reference genes were established during 1 g conditions and therefore their applicability in studies with altered gravity has not been demonstrated yet. The microarray technology is frequently used to generate expression profiles under defined conditions and to determine the relative difference in expression levels between two or more different states. In our study, we searched for potential reference genes with stable expression during different gravitational conditions (microgravity, normogravity, and hypergravity) which are additionally not altered in different hardware systems. We were able to identify eight genes (ALB, B4GALT6, GAPDH, HMBS, YWHAZ, ABCA5, ABCA9, and ABCC1) which demonstrated no altered gene expression levels in all tested conditions and therefore represent good candidates for the standardization of gene expression studies in altered gravity.

Assessing ecological departure from reference conditions with the Fire Regime Condition Class (FRCC) Mapping Tool

Treesearch

Stephen W. Barrett; Thomas DeMeo; Jeffrey L. Jones; J.D. Zeiler; Lee C. Hutter

2006-01-01

Knowledge of ecological departure from a range of reference conditions provides a critical context for managing sustainable ecosystems. Fire Regime Condition Class (FRCC) is a qualitative measure characterizing possible departure from historical fire regimes. The FRCC Mapping Tool was developed as an ArcMap extension utilizing the protocol identified by the Interagency...

Nutrient concentrations and their relations to the biotic integrity of wadeable streams in Wisconsin

USGS Publications Warehouse

Robertson, Dale M.; Graczyk, David J.; Garrison, Paul J.; Wang, Lizhu; LaLiberte, Gina; Bannerman, Roger

2006-01-01

Excessive nutrient (phosphorus and nitrogen) loss from watersheds is frequently associated with degraded water quality in streams. To reduce this loss, agricultural performance standards and regulations for croplands and livestock operations are being proposed by various States. In addition, the U.S. Environmental Protection Agency is establishing regionally based nutrient criteria that can be refined by each State to determine whether actions are needed to improve a stream's water quality. More confidence in the environmental benefits of the proposed performance standards and nutrient criteria will be possible with a better understanding of the biotic responses to a range of nutrient concentrations in different environmental settings. The U.S. Geological Survey and the Wisconsin Department of Natural Resources collected data from 240 wadeable streams throughout Wisconsin to: 1) describe how nutrient concentrations and biotic-community structure vary throughout the State; 2) determine which environmental characteristics are most strongly related to the distribution of nutrient concentrations; 3) determine reference water-quality and biotic conditions for different areas of the State; 4) determine how the biotic community of streams in different areas of the State respond to changes in nutrient concentrations; 5) determine the best regionalization scheme to describe the patterns in reference conditions and the responses in water quality and the biotic community; and 6) develop new indices to estimate nutrient concentrations in streams from a combination of biotic indices. The ultimate goal of this study is to provide the information needed to guide the development of regionally based nutrient criteria for Wisconsin streams. For total nitrogen (N) and suspended chlorophyll (SCHL) concentrations and water clarity, regional variability in reference conditions and in the responses in water quality to changes in land use are best described by subdividing wadeable streams into two categories: streams in areas with high clay-content soils (Environmental Phosphorus Zone 3, EPZ 3) and streams throughout the rest of the State. The regional variability in the response in total phosphorus (P) concentrations is also best described by subdividing the streams into these two categories; however, little consistent variability was found in reference P concentrations in streams throughout the State. Reference P concentrations are smilar throughout the State (0.03-0.04 mg/L). Reference N concentrations are divided into two categories: 0.6-0.7 mg/L in all streams except those in areas with high clay-content soils, where 0.4 mg/L is more appropriate. Reference SCHL concentrations are divided into two categories: 1.2-1.7 ?g/L in all streams except those in areas with high clay-content soils, where 1.0 ?g/L may be more appropriate. Reference water clarity is divided into two categories: streams in areas with high clay-content soils with a lower reference water clarity (Secchi tube depth, SD, of about 110 cm) and streams throughout the rest of the State (SD greater than or equal to about 115 cm). For each category of the biotic community (SCHL and benthic chlorophyll a concentrations (BCHL), periphytic diatoms, macroinvertebrates, and fish), a few biotic indices were more related to differences in nutrient concentrations than were others. For each of the indices more strongly related to nutrient concentrations, reference conditions were obtained by determining values corresponding to the worst 75th percentile value from a subset of minimally impacted streams (streams having reference nutrient concentrations). By examining the biotic community in streams having either reference P or N concentrations but not both, the relative importance of these two nutrients was determined. For SCHL, P was the more important limiting nutrient; however, for BCHL and all macroinvertebrate indices, it appears that N was the more important nutrient when concent

Computer Aided Reference Services in the Academic Library: Experiences in Organizing and Operating an Online Reference Service.

ERIC Educational Resources Information Center

Hoover, Ryan E.

1979-01-01

Summarizes the development of the Computer-Aided Reference Services (CARS) division of the University of Utah Libraries' reference department. Development, organizational structure, site selection, equipment, management, staffing and training considerations, promotion and marketing, budget and pricing, record keeping, statistics, and evaluation…

Selection of suitable reference genes for gene expression studies in Staphylococcus capitis during growth under erythromycin stress.

PubMed

Cui, Bintao; Smooker, Peter M; Rouch, Duncan A; Deighton, Margaret A

2016-08-01

Accurate and reproducible measurement of gene transcription requires appropriate reference genes, which are stably expressed under different experimental conditions to provide normalization. Staphylococcus capitis is a human pathogen that produces biofilm under stress, such as imposed by antimicrobial agents. In this study, a set of five commonly used staphylococcal reference genes (gyrB, sodA, recA, tuf and rpoB) were systematically evaluated in two clinical isolates of Staphylococcus capitis (S. capitis subspecies urealyticus and capitis, respectively) under erythromycin stress in mid-log and stationary phases. Two public software programs (geNorm and NormFinder) and two manual calculation methods, reference residue normalization (RRN) and relative quantitative (RQ), were applied. The potential reference genes selected by the four algorithms were further validated by comparing the expression of a well-studied biofilm gene (icaA) with phenotypic biofilm formation in S. capitis under four different experimental conditions. The four methods differed considerably in their ability to predict the most suitable reference gene or gene combination for comparing icaA expression under different conditions. Under the conditions used here, the RQ method provided better selection of reference genes than the other three algorithms; however, this finding needs to be confirmed with a larger number of isolates. This study reinforces the need to assess the stability of reference genes for analysis of target gene expression under different conditions and the use of more than one algorithm in such studies. Although this work was conducted using a specific human pathogen, it emphasizes the importance of selecting suitable reference genes for accurate normalization of gene expression more generally.

Hallmarks of mechanochemistry: from nanoparticles to technology.

PubMed

Baláž, Peter; Achimovičová, Marcela; Baláž, Matej; Billik, Peter; Cherkezova-Zheleva, Zara; Criado, José Manuel; Delogu, Francesco; Dutková, Erika; Gaffet, Eric; Gotor, Francisco José; Kumar, Rakesh; Mitov, Ivan; Rojac, Tadej; Senna, Mamoru; Streletskii, Andrey; Wieczorek-Ciurowa, Krystyna

2013-09-21

The aim of this review article on recent developments of mechanochemistry (nowadays established as a part of chemistry) is to provide a comprehensive overview of advances achieved in the field of atomistic processes, phase transformations, simple and multicomponent nanosystems and peculiarities of mechanochemical reactions. Industrial aspects with successful penetration into fields like materials engineering, heterogeneous catalysis and extractive metallurgy are also reviewed. The hallmarks of mechanochemistry include influencing reactivity of solids by the presence of solid-state defects, interphases and relaxation phenomena, enabling processes to take place under non-equilibrium conditions, creating a well-crystallized core of nanoparticles with disordered near-surface shell regions and performing simple dry time-convenient one-step syntheses. Underlying these hallmarks are technological consequences like preparing new nanomaterials with the desired properties or producing these materials in a reproducible way with high yield and under simple and easy operating conditions. The last but not least hallmark is enabling work under environmentally friendly and essentially waste-free conditions (822 references).

Conditioning of sewage sludge by Fenton's reagent combined with skeleton builders.

PubMed

Liu, Huan; Yang, Jiakuan; Shi, Yafei; Li, Ye; He, Shu; Yang, Changzhu; Yao, Hong

2012-06-01

Physical conditioners, often known as skeleton builders, are commonly used to improve the dewaterability of sewage sludge. This study evaluated a novel joint usage of Fenton's reagent and skeleton builders, referred to as the F-S inorganic composite conditioner, focusing on their efficacies and the optimization of the major operational parameters. The results demonstrate that the F-S composite conditioner for conditioning sewage sludge is a viable alternative to conventional organic polymers, especially when ordinary Portland cement (OPC) and lime are used as the skeleton builders. Experimental investigations confirmed that Fenton reaction required sufficient time (80 min in this study) to degrade organics in the sludge. The optimal condition of this process was at pH=5, Fe(2+)=40 mg g(-1) (dry solids), H(2)O(2)=32 mg g(-1), OPC=300 mg g(-1) and lime=400 mg g(-1), in which the specific resistance to filtration reduction efficiency of 95% was achieved. Copyright © 2012 Elsevier Ltd. All rights reserved.

A Numerical Study of Spray Injected in a Gas Turbine Lean Pre-Mixed Pre-Vaporized Combustor

NASA Astrophysics Data System (ADS)

Amoresano, Amedeo; Cameretti, Maria Cristina; Tuccillo, Raffaele

2015-04-01

The authors have performed a numerical study to investigate the spray evolution in a modern gas turbine combustor of the Lean Pre-Mixed Pre-vaporized type. The CFD tool is able to simulate the injection conditions, by isolating and studying some specific phenomena. The calculations have been performed by using a 3-D fluid dynamic code, the FLUENT flow solver, by choosing the injection models on the basis of a comparative analysis with some experimental data, in terms of droplet diameters, obtained by PDA technique. In a first phase of the investigation, the numerical simulation refers to non-evaporating flow conditions, in order to validate the estimation of the fundamental spray parameters. Next, the calculations employ boundary conditions close to those occurring in the actual combustor operation, in order to predict the fuel vapour distribution throughout the premixing chamber. The results obtained allow the authors to perform combustion simulation in the whole domain.

Time Projection Compton Spectrometer (TPCS). User`s guide

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

Landron, C.O.; Baldwin, G.T.

1994-04-01

The Time Projection Compton Spectrometer (TPCS) is a radiation diagnostic designed to determine the time-integrated energy spectrum between 100 keV -- 2 MeV of flash x-ray sources. This guide is intended as a reference for the routine operator of the TPCS. Contents include a brief overview of the principle of operation, detailed component descriptions, detailed assembly and disassembly procedures, guide to routine operations, and troubleshooting flowcharts. Detailed principle of operation, signal analysis and spectrum unfold algorithms are beyond the scope of this guide; however, the guide makes reference to sources containing this information.

Accuracy of available methods for quantifying the heat power generation of nanoparticles for magnetic hyperthermia.

PubMed

Andreu, Irene; Natividad, Eva

2013-12-01

In magnetic hyperthermia, characterising the specific functionality of magnetic nanoparticle arrangements is essential to plan the therapies by simulating maximum achievable temperatures. This functionality, i.e. the heat power released upon application of an alternating magnetic field, is quantified by means of the specific absorption rate (SAR), also referred to as specific loss power (SLP). Many research groups are currently involved in the SAR/SLP determination of newly synthesised materials by several methods, either magnetic or calorimetric, some of which are affected by important and unquantifiable uncertainties that may turn measurements into rough estimates. This paper reviews all these methods, discussing in particular sources of uncertainties, as well as their possible minimisation. In general, magnetic methods, although accurate, do not operate in the conditions of magnetic hyperthermia. Calorimetric methods do, but the easiest to implement, the initial-slope method in isoperibol conditions, derives inaccuracies coming from the lack of matching between thermal models, experimental set-ups and measuring conditions, while the most accurate, the pulse-heating method in adiabatic conditions, requires more complex set-ups.

Boundary condition identification for a grid model by experimental and numerical dynamic analysis

NASA Astrophysics Data System (ADS)

Mao, Qiang; Devitis, John; Mazzotti, Matteo; Bartoli, Ivan; Moon, Franklin; Sjoblom, Kurt; Aktan, Emin

2015-04-01

There is a growing need to characterize unknown foundations and assess substructures in existing bridges. It is becoming an important issue for the serviceability and safety of bridges as well as for the possibility of partial reuse of existing infrastructures. Within this broader contest, this paper investigates the possibility of identifying, locating and quantifying changes of boundary conditions, by leveraging a simply supported grid structure with a composite deck. Multi-reference impact tests are operated for the grid model and modification of one supporting bearing is done by replacing a steel cylindrical roller with a roller of compliant material. Impact based modal analysis provide global modal parameters such as damped natural frequencies, mode shapes and flexibility matrix that are used as indicators of boundary condition changes. An updating process combining a hybrid optimization algorithm and the finite element software suit ABAQUS is presented in this paper. The updated ABAQUS model of the grid that simulates the supporting bearing with springs is used to detect and quantify the change of the boundary conditions.

Effect of micro-aeration on anaerobic digestion of primary sludge under septic tank conditions.

PubMed

Diak, James; Örmeci, Banu; Kennedy, Kevin J

2013-04-01

Micro-aeration, which refers to the addition of very small amounts of air, is a simple technology that can potentially be incorporated in septic tanks to improve the digestion performance. The purpose of this study was to investigate and compare the effects of micro-aeration on anaerobic digestion of primary sludge under septic tank conditions. 1.6 L batch reactor experiments were carried out in duplicate using raw primary sludge, with 4.1 % total solids, and diluted primary sludge, with 2.1 % total solids. Reactors were operated for 5 weeks at room temperature to simulate septic tank conditions. Micro-aeration rate of 0.00156 vvm effectively solubilised chemical oxygen demand (COD) and improved the subsequent degradation of COD. Micro-aeration also increased the generation of ammonia and soluble proteins, but did not improve the reduction in total and volatile solids, or the reduction in carbohydrates. Experiments using diluted sludge samples showed similar trends as the experiments with raw sludge, which suggest that initial solids concentration did not have a significant effect on the degradation of primary sludge under septic tank conditions.

10 CFR 431.95 - Materials incorporated by reference.

Code of Federal Regulations, 2011 CFR

2011-01-01

... reference. (1) Air-Conditioning and Refrigeration Institute (ARI) Standard 210/240-2003 published in 2003... standards from the Air-Conditioning and Refrigeration Institute, 4301 North Fairfax Drive, Suite 425...

Biographical Sources in Science and Technology, Engineering Reference Books, and General Sources for Financial Ratios and Operating Ratios. Bibliographic Series No. 12.

ERIC Educational Resources Information Center

Ahrens, Joan

The selected information sources held by the Arkansas University library which are listed include such general sources as Moody's and Standard and Poor's publications and bibliographies for financial and operating ratios. Reference books for engineering published between 1965-1976 include handbooks, dictionaries, manuals, encyclopedias,…

43 CFR 3160.0-7 - Cross references.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) ONSHORE OIL AND GAS OPERATIONS Onshore Oil and Gas Operations: General § 3160.0-7 Cross references. 25 CFR parts 221, 212, 213, and 227 30 CFR Group 200 40 CFR Chapter V 43 CFR parts 2, 4, and 1820 and Groups 3000, 3100 and 3500 [48 FR 36584, Aug. 12, 1983] ...

Regional metamorphism at extreme conditions: Implications for orogeny at convergent plate margins

NASA Astrophysics Data System (ADS)

Zheng, Yong-Fei; Chen, Ren-Xu

2017-09-01

Regional metamorphism at extreme conditions refers either to Alpine-type metamorphism at low geothermal gradients of <10 °C/km, or to Buchan-type metamorphism at high geothermal gradients of >30 °C/km. Extreme pressures refer to those above the polymorphic transition of quartz to coesite, so that ultrahigh-pressure (UHP) eclogite-facies metamorphism occurs at mantle depths of >80 km. Extreme temperatures refer to those higher than 900 °C at crustal depths of ≤80 km, so that ultrahigh-temperature (UHT) granulite-facies metamorphism occurs at medium to high pressures. While crustal subduction at the low geothermal gradients results in blueschist-eclogite facies series without arc volcanism, heating of the thinned orogenic lithosphere brings about the high geothermal gradients for amphibolite-granulite facies series with abundant magmatism. Therefore, UHP metamorphic rocks result from cold lithospheric subduction to the mantle depths, whereas UHT metamorphic rocks are produced by hot underplating of the asthenospheric mantle at the crustal depths. Active continental rifting is developed on the thinned lithosphere in response to asthenospheric upwelling, and this tectonism is suggested as a feasible mechanism for regional granulite-facies metamorphism, with the maximum temperature depending on the extent to which the mantle lithosphere is thinned prior to the rifting. While lithospheric compression is associated with subduction metamorphism in accretionary and collisional orogens, the thinned orogenic lithosphere undergoes extension due to the asthenospheric upwelling to result in orogen-parallel rifting metamorphism and magmatism. Thus, the rifting metamorphism provides a complement to the subduction metamorphism and its operation marks the asthenospheric heating of the orogenic lithosphere. Because of the partial melting and melt extraction of the lower continental crust, contemporaneous granite-migmatite-granulite associations may serve as a petrological indicator of rifting orogeny that is superimposed on precedingly accretionary and collisional orogens. The UHT metamorphic rocks have occurred since the Archean, suggesting that the hot underplating has operated very early in the Earth's history. In contrast, the UHP metamorphic rocks primarily occur in the Phanerozoic, indicating that the thermal regime of many subduction zones has changed since the Neoproterozoic for the cold subduction.

An integrated low phase noise radiation-pressure-driven optomechanical oscillator chipset

PubMed Central

Luan, Xingsheng; Huang, Yongjun; Li, Ying; McMillan, James F.; Zheng, Jiangjun; Huang, Shu-Wei; Hsieh, Pin-Chun; Gu, Tingyi; Wang, Di; Hati, Archita; Howe, David A.; Wen, Guangjun; Yu, Mingbin; Lo, Guoqiang; Kwong, Dim-Lee; Wong, Chee Wei

2014-01-01

High-quality frequency references are the cornerstones in position, navigation and timing applications of both scientific and commercial domains. Optomechanical oscillators, with direct coupling to continuous-wave light and non-material-limited f × Q product, are long regarded as a potential platform for frequency reference in radio-frequency-photonic architectures. However, one major challenge is the compatibility with standard CMOS fabrication processes while maintaining optomechanical high quality performance. Here we demonstrate the monolithic integration of photonic crystal optomechanical oscillators and on-chip high speed Ge detectors based on the silicon CMOS platform. With the generation of both high harmonics (up to 59th order) and subharmonics (down to 1/4), our chipset provides multiple frequency tones for applications in both frequency multipliers and dividers. The phase noise is measured down to −125 dBc/Hz at 10 kHz offset at ~400 μW dropped-in powers, one of the lowest noise optomechanical oscillators to date and in room-temperature and atmospheric non-vacuum operating conditions. These characteristics enable optomechanical oscillators as a frequency reference platform for radio-frequency-photonic information processing. PMID:25354711

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

Kang, Moses; Kim, Keonhui; Muljadi, Eduard

This paper proposes a torque limit-based inertial control scheme of a doubly-fed induction generator (DFIG) that supports the frequency control of a power system. If a frequency deviation occurs, the proposed scheme aims to release a large amount of kinetic energy (KE) stored in the rotating masses of a DFIG to raise the frequency nadir (FN). Upon detecting the event, the scheme instantly increases its output to the torque limit and then reduces the output with the rotor speed so that it converges to the stable operating range. To restore the rotor speed while causing a small second frequency dipmore » (SFD), after the rotor speed converges the power reference is reduced by a small amount and maintained until it meets the reference for maximum power point tracking control. The test results demonstrate that the scheme can improve the FN and maximum rate of change of frequency while causing a small SFD in any wind conditions and in a power system that has a high penetration of wind power, and thus the scheme helps maintain the required level of system reliability. The scheme releases the KE from 2.9 times to 3.7 times the Hydro-Quebec requirement depending on the power reference.« less

Process-based reference conditions: An alternative approach for managed river systems

NASA Astrophysics Data System (ADS)

Grams, P.; Melis, T.; Wright, S.; Schmidt, J.; Topping, D.

2008-12-01

Physical reference conditions, whether based on historic information or the condition of nearby less impaired systems, provide necessary information that contributes to an assessment of stream condition and the nature of channel transformation. In many cases, however, the utility of this traditional 'reference' approach may end at the assessment stage and not be applicable to establishing and implementing restoration goals. Ongoing impacts such as continued existence of an upstream dam or the persistence of invasive vegetation may render restoration based on a physical reference infeasible. In these circumstances, an alternative approach is to identify and describe reference processes in place of physical reference conditions. This is the case for the Colorado River where large dams, a commitment to hydropower production, and legal mandates for regional distribution and off- channel consumption of water greatly reduce the relevance of historical conditions in setting goals for rehabilitation. In this setting, two strategies are available for setting reference conditions. One is maintenance of post-dam sediment mass balance, which attempts to ensure that the channel does not continue to degrade or aggrade and that riverine habitats do not continue to diverge from their historical condition. Post- dam sediment mass balance can be quantified at a reconnaissance or project scale. The second strategy is to define key processes that maintain the native ecosystem. These processes may, or may not, be consistent with maintenance of sediment mass balance, but they may be key to rejuvenation of spawning and rearing habitats, maintenance of historical ranges of temperature and turbidity, maintenance of a sustainable food base for the native aquatic community, or maintaining other riverine resources. Both strategies require careful monitoring of processes (e.g. sediment flux), which may add considerably to the cost and complexity of a monitoring program. An additional challenge in adopting the second strategy is that it is difficult to define when a process is adequately restored, since many ecosystem processes collectively limit recovery of populations of native communities.

Memory for Details with Self-Referencing

PubMed Central

Serbun, Sarah J.; Shih, Joanne Y.; Gutchess, Angela H.

2011-01-01

Self-referencing benefits item memory, but little is known about the ways in which referencing the self affects memory for details. Experiment 1 assessed whether the effects of self-referencing operate only at the item, or general, level or also enhance memory for specific visual details of objects. Participants incidentally encoded objects by making judgments in reference to the self, a close other (one’s mother), or a familiar other (Bill Clinton). Results indicate that referencing the self or a close other enhances both specific and general memory. Experiments 2 and 3 assessed verbal memory for source in a task that relied on distinguishing between different mental operations (internal sources). Results indicate that self-referencing disproportionately enhances source memory, relative to conditions referencing other people, semantic, or perceptual information. We conclude that self-referencing not only enhances specific memory for both visual and verbal information, but can disproportionately improve memory for specific internal source details as well. PMID:22092106

Four-dimensional gravity as an almost-Poisson system

NASA Astrophysics Data System (ADS)

Ita, Eyo Eyo

2015-04-01

In this paper, we examine the phase space structure of a noncanonical formulation of four-dimensional gravity referred to as the Instanton representation of Plebanski gravity (IRPG). The typical Hamiltonian (symplectic) approach leads to an obstruction to the definition of a symplectic structure on the full phase space of the IRPG. We circumvent this obstruction, using the Lagrange equations of motion, to find the appropriate generalization of the Poisson bracket. It is shown that the IRPG does not support a Poisson bracket except on the vector constraint surface. Yet there exists a fundamental bilinear operation on its phase space which produces the correct equations of motion and induces the correct transformation properties of the basic fields. This bilinear operation is known as the almost-Poisson bracket, which fails to satisfy the Jacobi identity and in this case also the condition of antisymmetry. We place these results into the overall context of nonsymplectic systems.

UMTRA project list of reportable occurrences

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

Not Available

1994-04-01

This UMTRA Project List of Reportable occurrences is provided to facilitate efficient categorization of reportable occurrences. These guidelines have been established in compliance with DOE minimum reporting requirements under DOE Order 5000.3B. Occurrences are arranged into nine groups relating to US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project operations for active sites. These nine groupings are provided for reference to determined whether an occurrence meets reporting requirement criteria in accordance with the minimum reporting requirements. Event groups and significance categories that cannot or will not occur, and that do not apply to UMTRA Project operations, aremore » omitted. Occurrence categorization shall be as follows: Group 1. Facility Condition; Group 2. Environmental; Group 3. Personnel Safety; Group 4. Personnel Radiation Protection; Group 5. Safeguards and Security; Group 6. Transportation; Group 7. Value Basis Reporting; Group 8. Facility Status; and Group 9. Cross-Category Items.« less

A theoretical study on tunneling based biosensor having a redox-active monolayer using physics based simulation

NASA Astrophysics Data System (ADS)

Kim, Kyoung Yeon; Lee, Won Cheol; Yun, Jun Yeon; Lee, Youngeun; Choi, Seoungwook; Jin, Seonghoon; Park, Young June

2018-01-01

We developed a numerical simulator to model the operation of a tunneling based biosensor which has a redox-active monolayer. The simulator takes a realistic device structure as a simulation domain, and it employs the drift-diffusion equation for ion transport, the non-equilibrium Green's function formalism for electron tunneling, and the Ramo-Shockley theorem for accurate calculation of non-faradaic current. We also accounted for the buffer reaction and the immobilized peptide layer. For efficient transient simulation, the implicit time integration scheme is employed where the solution at each time step is obtained from the coupled Newton-Raphson method. As an application, we studied the operation of a recently fabricated reference-electrode free biosensor in various bias conditions and confirmed the effect of buffer reaction and the current flowing mechanism. Using the simulator, we also found a strategy to maximize the sensitivity of the tunneling based sensor.

Memory for details with self-referencing.

PubMed

Serbun, Sarah J; Shih, Joanne Y; Gutchess, Angela H

2011-11-01

Self-referencing benefits item memory, but little is known about the ways in which referencing the self affects memory for details. Experiment 1 assessed whether the effects of self-referencing operate only at the item, or general, level or whether they also enhance memory for specific visual details of objects. Participants incidentally encoded objects by making judgements in reference to the self, a close other (one's mother), or a familiar other (Bill Clinton). Results indicate that referencing the self or a close other enhances both specific and general memory. Experiments 2 and 3 assessed verbal memory for source in a task that relied on distinguishing between different mental operations (internal sources). The results indicate that self-referencing disproportionately enhances source memory, relative to conditions referencing other people, semantic, or perceptual information. We conclude that self-referencing not only enhances specific memory for both visual and verbal information, but can also disproportionately improve memory for specific internal source details.

Acute Calcific Tendinitis of the Index Finger in a Child.

PubMed

Walocko, Frances M; Sando, Ian C; Haase, Steven C; Kozlow, Jeffrey H

2017-09-01

Calcific tendinitis is characterized by calcium hydroxyapatite crystal deposition within tendons and is a common cause of musculoskeletal pain in adults. Its clinical manifestations may be acute, chronic, or asymptomatic. Acute calcific tendinitis is self-resolving condition that is rarely reported in the pediatric population and may be overlooked for more common processes, leading to unnecessary treatment. A chart reivew was performed of a single case of acute calcific tendonitis of the index finger in a child. We describe a case of calcific tendinitis of the index finger in a 9-year-old boy who was referred to us for a second opinion after surgical exploration of an acutely inflamed digit was recommended based on his initial presentation. The calcifications and symptoms resolved over time without operative management. Although rare in children, acute calcific tendinitis can present similar to an infection. However, appropriate managment is non-operative as the symptoms and radiographic findings resolve over time.

Operating and environmental characteristics of Sigma Tau hydrogen masers used in the Very Long Baseline Array (VLBA)

NASA Technical Reports Server (NTRS)

Tucker, T. K.

1989-01-01

Presented here are the results obtained from performance evaluation of a pair of Sigma Tau Standards Corporation Model VLBA-112 active hydrogen maser frequency standards. These masers were manufactured for the National Radio Astronomy Observatory (NRAO) for use on the Very Long Baseline Array (VLBA) project and were furnished to the Jet Propulsion Laboratory (JPL) for the purpose of these tests. Tests on the two masers were performed in the JPL Frequency Standards Laboratory (FSL) and included the characterization of output frequency stability versus environmental factors such as temperature, humidity, magnetic field, and barometric pressure. The performance tests also included the determination of phase noise and Allan variance using both FSL and Sigma Tau masers as references. All tests were conducted under controlled laboratory conditions, with only the desired environmental and operational parameters varied to determine sensitivity to external environment.

The Impeller Exit Flow Coefficient As a Performance Map Variable for Predicting Centrifugal Compressor Off-Design Operation Applied to a Supercritical CO 2 Working Fluid

DOE PAGES

Liese, Eric; Zitney, Stephen E.

2017-06-26

A multi-stage centrifugal compressor model is presented with emphasis on analyzing use of an exit flow coefficient vs. an inlet flow coefficient performance parameter to predict off-design conditions in the critical region of a supercritical carbon dioxide (CO 2) power cycle. A description of the performance parameters is given along with their implementation in a design model (number of stages, basic sizing, etc.) and a dynamic model (for use in transient studies). A design case is shown for two compressors, a bypass compressor and a main compressor, as defined in a process simulation of a 10 megawatt (MW) supercritical COmore » 2 recompression Brayton cycle. Simulation results are presented for a simple open cycle and closed cycle process with changes to the inlet temperature of the main compressor which operates near the CO 2 critical point. Results showed some difference in results using the exit vs. inlet flow coefficient correction, however, it was not significant for the range of conditions examined. Here, this paper also serves as a reference for future works, including a full process simulation of the 10 MW recompression Brayton cycle.« less

The Impeller Exit Flow Coefficient As a Performance Map Variable for Predicting Centrifugal Compressor Off-Design Operation Applied to a Supercritical CO 2 Working Fluid

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

Liese, Eric; Zitney, Stephen E.

A multi-stage centrifugal compressor model is presented with emphasis on analyzing use of an exit flow coefficient vs. an inlet flow coefficient performance parameter to predict off-design conditions in the critical region of a supercritical carbon dioxide (CO 2) power cycle. A description of the performance parameters is given along with their implementation in a design model (number of stages, basic sizing, etc.) and a dynamic model (for use in transient studies). A design case is shown for two compressors, a bypass compressor and a main compressor, as defined in a process simulation of a 10 megawatt (MW) supercritical COmore » 2 recompression Brayton cycle. Simulation results are presented for a simple open cycle and closed cycle process with changes to the inlet temperature of the main compressor which operates near the CO 2 critical point. Results showed some difference in results using the exit vs. inlet flow coefficient correction, however, it was not significant for the range of conditions examined. Here, this paper also serves as a reference for future works, including a full process simulation of the 10 MW recompression Brayton cycle.« less

Altitude Effects on Thermal Ice Protection System Performance; a Study of an Alternative Approach

NASA Technical Reports Server (NTRS)

Addy, Harold E., Jr.; Orchard, David; Wright, William B.; Oleskiw, Myron

2016-01-01

Research has been conducted to better understand the phenomena involved during operation of an aircraft's thermal ice protection system under running wet icing conditions. In such situations, supercooled water striking a thermally ice-protected surface does not fully evaporate but runs aft to a location where it freezes. The effects of altitude, in terms of air pressure and density, on the processes involved were of particular interest. Initial study results showed that the altitude effects on heat energy transfer were accurately modeled using existing methods, but water mass transport was not. Based upon those results, a new method to account for altitude effects on thermal ice protection system operation was proposed. The method employs a two-step process where heat energy and mass transport are sequentially matched, linked by matched surface temperatures. While not providing exact matching of heat and mass transport to reference conditions, the method produces a better simulation than other methods. Moreover, it does not rely on the application of empirical correction factors, but instead relies on the straightforward application of the primary physics involved. This report describes the method, shows results of testing the method, and discusses its limitations.

Geomorphological reference condition definition as a basis for river restoration and river management: the example of Oiartzun, Oria and Urumea River basins (Basque Country)

NASA Astrophysics Data System (ADS)

Ibisate, Askoa; Ollero, Alfredo; Sáenz de Olazagoitia, Ana; Acín, Vanesa; Granado, David; Herrero, Xabier; Horacio, Jesús

2017-04-01

The application of hydrogeomorphology as a tool for river management and decision making on reference condition definition for river restoration is presented. Water Framework Directive (2000/60/CE) requires the identification of reference conditions and attainable target images, to achieve the good ecological status, taking into account the direct and indirect changes in the basin and river course. Data collection was done through an exhaustive fieldwork and GIS tools. Based on geomorphological homogeneous river reaches identification (waterfall, bedrock, step-pool, cascade, coluvial, run, riffle-pool, heavily modified), the hydrogeomorphological assessment of all of them in relation to its "natural" condition allowed the identification of those with a good or very good hydrogeomorphological condition, considered as reference condition. The loss of hydrogeomorphological quality was closely linked to sociodemographical pressure, due to artificial elements in the river course, floodplain and land use changes on the basin. The assessment done based on pressures and impacts allowed the proposal of specific restoration objectives which facilitated the identification of the elements that degrade the hydrogeomorphological quality of the reaches, and helped the identification of specific restoration actions. In addition it was possible to set the reaches with the potentiality of being restored, those reversible and those that due to its high degradation were considered irreversible, and therefore not able to be restored, except for some rehabilitation or mitigation measures. The application in two basins, Oria and Oiartzun, concluded that 36% of the reaches could recover their geomorphological good status and a 40% could be considered as reference condition for other reaches. This geomorphological based reference condition definition could be linked and complete with ecological data.

78 FR 18415 - Connected Vehicle Reference Implementation Architecture Workshop; Notice of Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-26

... DEPARTMENT OF TRANSPORTATION Connected Vehicle Reference Implementation Architecture Workshop...) Intelligent Transportation System Joint Program Office (ITS JPO) will host a free Connected Vehicle Reference... manufacturing, developing, deploying, operating, or maintaining the connected [[Page 18416

Simulation Evaluation of Equivalent Vision Technologies for Aerospace Operations

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Williams, Steven P.; Wilz, Susan J.; Arthur, Jarvis J.

2009-01-01

A fixed-based simulation experiment was conducted in NASA Langley Research Center s Integration Flight Deck simulator to investigate enabling technologies for equivalent visual operations (EVO) in the emerging Next Generation Air Transportation System operating environment. EVO implies the capability to achieve or even improve on the safety of current-day Visual Flight Rules (VFR) operations, maintain the operational tempos of VFR, and perhaps even retain VFR procedures - all independent of the actual weather and visibility conditions. Twenty-four air transport-rated pilots evaluated the use of Synthetic/Enhanced Vision Systems (S/EVS) and eXternal Vision Systems (XVS) technologies as enabling technologies for future all-weather operations. The experimental objectives were to determine the feasibility of XVS/SVS/EVS to provide for all weather (visibility) landing capability without the need (or ability) for a visual approach segment and to determine the interaction of XVS/EVS and peripheral vision cues for terminal area and surface operations. Another key element of the testing investigated the pilot's awareness and reaction to non-normal events (i.e., failure conditions) that were unexpectedly introduced into the experiment. These non-normal runs served as critical determinants in the underlying safety of all-weather operations. Experimental data from this test are cast into performance-based approach and landing standards which might establish a basis for future all-weather landing operations. Glideslope tracking performance appears to have improved with the elimination of the approach visual segment. This improvement can most likely be attributed to the fact that the pilots didn't have to simultaneously perform glideslope corrections and find required visual landing references in order to continue a landing. Lateral tracking performance was excellent regardless of the display concept being evaluated or whether or not there were peripheral cues in the side window. Although workload ratings were significantly less when peripheral cues were present compared to when there were none, these differences appear to be operationally inconsequential. Larger display concepts tested in this experiment showed significant situation awareness (SA) improvements and workload reductions compared to smaller display concepts. With a fixed display size, a color display was more influential in SA and workload ratings than a collimated display.

NL(q) Theory: A Neural Control Framework with Global Asymptotic Stability Criteria.

PubMed

Vandewalle, Joos; De Moor, Bart L.R.; Suykens, Johan A.K.

1997-06-01

In this paper a framework for model-based neural control design is presented, consisting of nonlinear state space models and controllers, parametrized by multilayer feedforward neural networks. The models and closed-loop systems are transformed into so-called NL(q) system form. NL(q) systems represent a large class of nonlinear dynamical systems consisting of q layers with alternating linear and static nonlinear operators that satisfy a sector condition. For such NL(q)s sufficient conditions for global asymptotic stability, input/output stability (dissipativity with finite L(2)-gain) and robust stability and performance are presented. The stability criteria are expressed as linear matrix inequalities. In the analysis problem it is shown how stability of a given controller can be checked. In the synthesis problem two methods for neural control design are discussed. In the first method Narendra's dynamic backpropagation for tracking on a set of specific reference inputs is modified with an NL(q) stability constraint in order to ensure, e.g., closed-loop stability. In a second method control design is done without tracking on specific reference inputs, but based on the input/output stability criteria itself, within a standard plant framework as this is done, for example, in H( infinity ) control theory and &mgr; theory. Copyright 1997 Elsevier Science Ltd.

Laboratory Simulation and Measurement of Instrument Drift in Quartz-Resonant Pressure Gauges

NASA Astrophysics Data System (ADS)

Sasagawa, G. S.; Zumberge, M. A.

2017-12-01

Marine geodesy uses ocean bottom pressure sensors to measure vertical deformation of the sea floor, including that due to volcanic inflation and subsidence, episodic tremor and slip, plate subduction, and deformation due to hydrocarbon extraction at offshore reservoirs. Instrumental drift is inherent in existing pressure sensors and introduce uncertainties in data interpretation. Different methods have been developed to control drift, using varying techniques and instrumentation. Laboratory measurements of sensor drift, under controlled conditions that simulate seafloor pressures and temperatures, would allow for evaluating pressure gauge drift and the efficacy of new drift control methods. We have constructed and operated a laboratory system to monitor the drift of 15 quartz resonant pressure gauges over a year. The temperature and pressure are maintained and controlled at approximately 5 °C and 1900 dbar. A deadweight tester was used to provide a reference signal at frequent intervals; the time series of reference pressure signals is a direct measure of each gauge's drift. Several other tests were conducted, including a) evaluation of a custom outgassing sensor used as proxy for instrument drift, b) determination of the oscillator drift in the pressure gauge signal conditioning electronics, and c) a test of ambient air pressure calibration, also known as the A-0-A method. First results will be presented.

40 CFR 50.3 - Reference conditions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.3 Reference conditions. All measurements of air quality that... reported based on actual ambient air volume measured at the actual ambient temperature and pressure at the...

Electrostatic Discharge Test of Multi-Junction Solar Array Coupons After Combined Space Environmental Exposures

NASA Technical Reports Server (NTRS)

Wright, Kenneth H.; Schneider, Todd; Vaughn, Jason; Hoang, Bao; Funderburk, Victor V.; Wong, Frankie; Gardiner, George

2010-01-01

A set of multi-junction GaAs/Ge solar array test coupons were subjected to a sequence of 5-year increments of combined environmental exposure tests. The test coupons capture an integrated design intended for use in a geosynchronous (GEO) space environment. A key component of this test campaign is conducting electrostatic discharge (ESD) tests in the inverted gradient mode. The protocol of the ESD tests is based on the ISO/CD 11221, the ISO standard for ESD testing on solar array panels. This standard is currently in its final review with expected approval in 2010. The test schematic in the ISO reference has been modified with Space System/Loral designed circuitry to better simulate the on-orbit operational conditions of its solar array design. Part of the modified circuitry is to simulate a solar array panel coverglass flashover discharge. All solar array coupons used in the test campaign consist of 4 cells. The ESD tests are performed at the beginning of life (BOL) and at each 5-year environment exposure point. The environmental exposure sequence consists of UV radiation, electron/proton particle radiation, thermal cycling, and ion thruster plume. This paper discusses the coverglass flashover simulation, ESD test setup, and the importance of the electrical test design in simulating the on-orbit operational conditions. Results from 5th-year testing are compared to the baseline ESD characteristics determined at the BOL condition.

Numerical analyses of baseline JT-60SA design concepts with the COREDIV code

NASA Astrophysics Data System (ADS)

Zagórski, R.; Gałązka, K.; Ivanova-Stanik, I.; Stępniewski, W.; Garzotti, L.; Giruzzi, G.; Neu, R.; Romanelli, M.

2017-06-01

JT-60SA reference design scenarios at high (#3) and low (#2) density have been analyzed with the help of the self-consistent COREDIV code. Simulations results for a standard C wall and full W wall have been compared in terms of the influence of impurities, both intrinsic (C, W) and seeded (N, Ar, Ne, Kr), on the radiation losses and plasma parameters. For scenario #3 in a C environment, the regime of detachment on divertor plates can be achieved with N or Ne seeding, whereas for the low density and high power scenario (#2), the C and seeding impurity radiation does not effectively reduce power to the targets. In this case, only an increase of either average density or edge density together with Kr seeding might help to develop conditions with strong radiation losses and semi-detached conditions in the divertor. The calculations show that, in the case of a W divertor, the power load to the plate is mitigated by seeding and the central plasma dilution is smaller compared to the C divertor. For the high density case (#3) with Ne seeding, operation in full detachment mode is predicted. Ar seems to be an optimal choice for the low-density high-power scenario #2, showing a wide operating window, whereas Ne leads to high plasma dilution at high seeding levels albeit not achieving semi-detached conditions in the divertor.

Thermal lensing effects in rod-based Tm3+: YLF amplifiers versus pump and cooling conditions

NASA Astrophysics Data System (ADS)

Jolly, A.; Vidal, S.; Boullet, J.

2018-06-01

We report on a comprehensive study of the thermal-lensing penalties in rod-based, end-pumped amplifiers made of thulium-doped YLF. Aiming to optimize the beam quality under optimized pump and cooling conditions, this applies to the definition of highly efficient laser designs with operation up to the saturation of the gain. Single-pass and double-pass pump schemes are benchmarked by means of an innovative modeling process, to determine the appropriate rod’s length and the complete set of input data which determines the spatial transfer function of a given rod. This is done in the form of an equivalent, pump-dependent, thick GRIN lens. The characteristics of this highly astigmatic and basically divergent lens are computed thanks to complementary 3D-FEM thermo-mechanical modeling. To benchmark the different contributors to natural thermal-lensing phenomena, we refer to the situation of uniform side-cooling. The computational results are parameterized in a broad range of operating conditions. Then we suggest non-uniform side-cooling, as a possible option of interest for cancelling the astigmatism. The development of YLF-based amplifiers of a new generation taking advantage of a highly stable and easily controllable beam quality, either using rod-based or slab-based architectures, will be part of the potential applications of this fairly generic modeling approach.

Cross - Scale Intercomparison of Climate Change Impacts Simulated by Regional and Global Hydrological Models in Eleven Large River Basins

NASA Technical Reports Server (NTRS)

Hattermann, F. F.; Krysanova, V.; Gosling, S. N.; Dankers, R.; Daggupati, P.; Donnelly, C.; Florke, M.; Huang, S.; Motovilov, Y.; Buda, S.;

Cross-scale intercomparison of climate change impacts simulated by regional and global hydrological models in eleven large river basins

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

Hattermann, F. F.; Krysanova, V.; Gosling, S. N.

Ideally, the results from models operating at different scales should agree in trend direction and magnitude of impacts under climate change. However, this implies that the sensitivity of impact models designed for either scale to climate variability and change is comparable. In this study, we compare hydrological changes simulated by 9 global and 9 regional hydrological models (HM) for 11 large river basins in all continents under reference and scenario conditions. The foci are on model validation runs, sensitivity of annual discharge to climate variability in the reference period, and sensitivity of the long-term average monthly seasonal dynamics to climatemore » change. One major result is that the global models, mostly not calibrated against observations, often show a considerable bias in mean monthly discharge, whereas regional models show a much better reproduction of reference conditions. However, the sensitivity of two HM ensembles to climate variability is in general similar. The simulated climate change impacts in terms of long-term average monthly dynamics evaluated for HM ensemble medians and spreads show that the medians are to a certain extent comparable in some cases with distinct differences in others, and the spreads related to global models are mostly notably larger. Summarizing, this implies that global HMs are useful tools when looking at large-scale impacts of climate change and variability, but whenever impacts for a specific river basin or region are of interest, e.g. for complex water management applications, the regional-scale models validated against observed discharge should be used.« less

Linking water quality guidelines to the natural characteristics of catchments in order to support distinct aquatic ecosystems: Water quality guidelines for suspended particulate matter

NASA Astrophysics Data System (ADS)

Bilotta, G. S.; Grove, M. K.; Harrison, C.; Joyce, C. B.; Peacock, C.

2012-12-01

The natural characteristics of a catchment provide a template that controls the background rates of geomorphological processes operating within that catchment, which in-turn determines the background physico-chemical and hydro-morphological characteristics of the catchment's surface waters. Large differences in the natural characteristics of catchments (e.g. geology, topography, climate), lead to unique physico-chemical and hydro-morphological conditions that support unique freshwater communities. However, this uniqueness is not always recognised in international water quality guidelines, which often attempt to apply blanket water-quality guidelines to 'protect' a wide range of ecosystems. In this paper we investigate the natural characteristics that control background concentrations of suspended particulate matter (SPM - including nano-scale particles to sand-sized sediments), which is a well-known cause of ecological degradation. At present, the management of SPM is hampered by a lack of understanding of the SPM conditions that water quality managers should aim to achieve in contrasting environments in order to support good ecological status. To address this, in this paper we examine the SPM preferences of contrasting biological communities that are in reference condition (minimal anthropogenic disturbance and high ecological status). We analyse historical SPM data collected on a monthly basis from a wide range of reference-condition temperate environments (638 stream/river sites comprising 42 different biological community-types). This analysis reveals that there are statistically significant differences (One-way ANOVA p < 0.001) between the background SPM concentrations observed in contrasting communities that are in reference condition. Mean background SPM concentrations for contrasting communities ranged from 1.7 to 26.2 mg L-1 (i.e. more than a 15-fold difference). We propose a model for predicting environment-specific water quality guidelines for SPM. In order to develop this model, the 638 reference-condition sites were first classified into one of five mean background SPM ranges (0.00-5.99, 6.00-11.99, 12.00-17.99, 18.00-23.99 and >24.00 mg L-1). Stepwise Multiple Discriminant Analysis (MDA) of these ranges showed that a site's SPM range can be predicted as a function of: mean annual air temperature, mean annual precipitation, mean altitude of upstream catchment, distance from source, slope to source, channel width and depth, the percentage of catchment area comprised of clay, chalk, and hard rock solid geology, and the percentage of the catchment area comprised of blown sand/landslide material as the surface (drift) material. Although the model is still being improved and developed, this research highlights the need to link water quality guidelines to the natural characteristics of catchments and the physico-chemical preferences of the biological communities that would naturally inhabit them.

Transforming community access to space science models

NASA Astrophysics Data System (ADS)

MacNeice, Peter; Hesse, Michael; Kuznetsova, Maria; Maddox, Marlo; Rastaetter, Lutz; Berrios, David; Pulkkinen, Antti

2012-04-01

Researching and forecasting the ever changing space environment (often referred to as space weather) and its influence on humans and their activities are model-intensive disciplines. This is true because the physical processes involved are complex, but, in contrast to terrestrial weather, the supporting observations are typically sparse. Models play a vital role in establishing a physically meaningful context for interpreting limited observations, testing theory, and producing both nowcasts and forecasts. For example, with accurate forecasting of hazardous space weather conditions, spacecraft operators can place sensitive systems in safe modes, and power utilities can protect critical network components from damage caused by large currents induced in transmission lines by geomagnetic storms.

Transforming Community Access to Space Science Models

NASA Technical Reports Server (NTRS)

MacNeice, Peter; Heese, Michael; Kunetsova, Maria; Maddox, Marlo; Rastaetter, Lutz; Berrios, David; Pulkkinen, Antti

2012-01-01

Researching and forecasting the ever changing space environment (often referred to as space weather) and its influence on humans and their activities are model-intensive disciplines. This is true because the physical processes involved are complex, but, in contrast to terrestrial weather, the supporting observations are typically sparse. Models play a vital role in establishing a physically meaningful context for interpreting limited observations, testing theory, and producing both nowcasts and forecasts. For example, with accurate forecasting of hazardous space weather conditions, spacecraft operators can place sensitive systems in safe modes, and power utilities can protect critical network components from damage caused by large currents induced in transmission lines by geomagnetic storms.

Preliminary investigation of the performance of a single tubular combustor at pressure up to 12 atmospheres

NASA Technical Reports Server (NTRS)

Wear, Jerrold D; Butze, Helmut F

1954-01-01

The effects of combustor operation at conditions representative of those encountered in high pressure-ratio turbojet engines or at high flight speeds on carbon deposition, exhaust smoke, and combustion efficiency were studied in a single tubular combustor. Carbon deposition and smoke formation tests were conducted over a range of combustor-inlet pressures from 33 to 173 pounds per square inch absolute and combustor reference velocities from 78 to 143 feet per second. Combustion efficiency tests were conducted over a range of pressures from 58 to 117 pounds per square inch absolute and velocities from 89 to 172 feet per second.

Pattern recognition monitoring of PEM fuel cell

DOEpatents

Meltser, M.A.

1999-08-31

The CO-concentration in the H{sub 2} feed stream to a PEM fuel cell stack is monitored by measuring current and voltage behavior patterns from an auxiliary cell attached to the end of the stack. The auxiliary cell is connected to the same oxygen and hydrogen feed manifolds that supply the stack, and discharges through a constant load. Pattern recognition software compares the current and voltage patterns from the auxiliary cell to current and voltage signature determined from a reference cell similar to the auxiliary cell and operated under controlled conditions over a wide range of CO-concentrations in the H{sub 2} fuel stream. 4 figs.

Pattern recognition monitoring of PEM fuel cell

DOEpatents

Meltser, Mark Alexander

1999-01-01

The CO-concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and voltage behavior patterns from an auxiliary cell attached to the end of the stack. The auxiliary cell is connected to the same oxygen and hydrogen feed manifolds that supply the stack, and discharges through a constant load. Pattern recognition software compares the current and voltage patterns from the auxiliary cell to current and voltage signature determined from a reference cell similar to the auxiliary cell and operated under controlled conditions over a wide range of CO-concentrations in the H.sub.2 fuel stream.

A Behavior-Analytic Account of Cognitive Bias in Clinical Populations

PubMed Central

Wray, Alisha M; Freund, Rachel A; Dougher, Michael J

2009-01-01

Cognitive bias refers to a well-established finding that individuals who suffer from certain clinical problems (e.g., depression, anxiety, posttraumatic stress disorder, substance abuse, etc.) selectively attend to, remember, and interpret events relevant to their condition. Although a body of literature exists that has tried to examine this phenomenon, most existing explanations are mentalistic and mediational. In this paper we offer a behavior-analytic account of cognitive bias, its development, and how it may contribute to maintenance of clinical problems. This account is based on establishing operations or motivating events, verbal processes, and relational responding. Clinical and future research implications are also discussed. PMID:22478512

Designing and Implementation a Lab Testing Method for Power Cables Insulation Resistance According with STAS 10411-89, SR EN ISO/CEI/17025/2005

NASA Astrophysics Data System (ADS)

Dobra, R.; Pasculescu, D.; Marc, G.; Risteiu, M.; Antonov, A.

2017-06-01

Insulation resistance measurement is one of the most important tests required by standards and regulations in terms of electrical safety. Why these tests are is to prevent possible accidents caused by electric shock, damage to equipment or outbreak of fire in normal operating conditions of electrical cables. The insulation resistance experiment refers to the testing of electrical cable insulation, which has a measured resistance that must be below the imposed regulations. Using a microcontroller system data regarding the insulation resistance of the power cables is acquired and with SCADA software the test results are displayed.

Computer program documentation for the dynamic analysis of a noncontacting mechanical face seal

NASA Technical Reports Server (NTRS)

Auer, B. M.; Etsion, I.

1980-01-01

A computer program is presented which achieves a numerical solution for the equations of motion of a noncontacting mechanical face seal. The flexibly-mounted primary seal ring motion is expressed by a set of second order differential equations for three degrees of freedom. These equations are reduced to a set of first order equations and the GEAR software package is used to solve the set of first order equations. Program input includes seal design parameters and seal operating conditions. Output from the program includes velocities and displacements of the seal ring about the axis of an inertial reference system. One example problem is described.

Increasing the Operational Value of Event Messages

NASA Technical Reports Server (NTRS)

Li, Zhenping; Savkli, Cetin; Smith, Dan

2003-01-01

Assessing the health of a space mission has traditionally been performed using telemetry analysis tools. Parameter values are compared to known operational limits and are plotted over various time periods. This presentation begins with the notion that there is an incredible amount of untapped information contained within the mission s event message logs. Through creative advancements in message handling tools, the event message logs can be used to better assess spacecraft and ground system status and to highlight and report on conditions not readily apparent when messages are evaluated one-at-a-time during a real-time pass. Work in this area is being funded as part of a larger NASA effort at the Goddard Space Flight Center to create component-based, middleware-based, standards-based general purpose ground system architecture referred to as GMSEC - the GSFC Mission Services Evolution Center. The new capabilities and operational concepts for event display, event data analyses and data mining are being developed by Lockheed Martin and the new subsystem has been named GREAT - the GMSEC Reusable Event Analysis Toolkit. Planned for use on existing and future missions, GREAT has the potential to increase operational efficiency in areas of problem detection and analysis, general status reporting, and real-time situational awareness.

High-quality remote interactive imaging in the operating theatre

NASA Astrophysics Data System (ADS)

Grimstead, Ian J.; Avis, Nick J.; Evans, Peter L.; Bocca, Alan

2009-02-01

We present a high-quality display system that enables the remote access within an operating theatre of high-end medical imaging and surgical planning software. Currently, surgeons often use printouts from such software for reference during surgery; our system enables surgeons to access and review patient data in a sterile environment, viewing real-time renderings of MRI & CT data as required. Once calibrated, our system displays shades of grey in Operating Room lighting conditions (removing any gamma correction artefacts). Our system does not require any expensive display hardware, is unobtrusive to the remote workstation and works with any application without requiring additional software licenses. To extend the native 256 levels of grey supported by a standard LCD monitor, we have used the concept of "PseudoGrey" where slightly off-white shades of grey are used to extend the intensity range from 256 to 1,785 shades of grey. Remote access is facilitated by a customized version of UltraVNC, which corrects remote shades of grey for display in the Operating Room. The system is successfully deployed at Morriston Hospital, Swansea, UK, and is in daily use during Maxillofacial surgery. More formal user trials and quantitative assessments are being planned for the future.

Development, Test, and Evaluation of Microwave Radar Water Level (MWWL) Sensors' Wave Measurement Capability

NASA Astrophysics Data System (ADS)

Iyer, S. K.; Heitsenrether, R.

2015-12-01

Waves can have a significant impact on many coastal operations including navigational safety, recreation, and even the economy. Despite this, as of 2009, there were only 181 in situ real-time wave observation networks nationwide (IOOS 2009). There has recently been interest in adding real-time wave measurement systems to already existing NOAA Center for Operational Oceanographic Products and Services (CO-OPS) stations. Several steps have already been taken in order to achieve this, such as integrating information from existing wave measurement buoys and initial testing of multiple different wave measurement systems (Heitsenrether et al. 2012). Since wave observations can be derived from high frequency water level changes, we will investigate water level sensors' capability to measure waves. Recently, CO-OPS has been transitioning to new microwave radar water level (MWWL) sensors which have higher resolution and theoretically a greater potential wave measurement capability than the acoustic sensors in stilling wells. In this study, we analyze the wave measurement capability of MWWL sensors at two high energy wave environments, Duck, NC and La Jolla, CA, and compare results to two "reference" sensors (A Nortek acoustic waves and currents profiler (AWAC) at Duck and a single point pressure sensor at La Jolla). A summary of results from the two field test sites will be presented, including comparisons of wave energy spectra, significant wave height, and peak period measured by the test MWWL sensors and both reference AWAC and pressure sensors. In addition, relationships between MWWL versus reference wave sensor differences and specific wave conditions will be discussed. Initial results from spectral analysis and the calculation of bulk wave parameters indicate that MWWL sensors set to the "NoFilter" processing setting can produce wave measurements capability that compare well to the two reference sensors. These results support continued development to enable the installation of MWWL sensors at CO-OPS locations as a method of measuring waves.

CERTS Microgrid Laboratory Test Bed - PIER Final Project Report

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

Eto, Joseph H.; Eto, Joseph H.; Lasseter, Robert

2008-07-25

The objective of the CERTS Microgrid Laboratory Test Bed project was to enhance the ease of integrating small energy sources into a microgrid. The project accomplished this objective by developing and demonstrating three advanced techniques, collectively referred to as the CERTS Microgrid concept, that significantly reduce the level of custom field engineering needed to operate microgrids consisting of small generating sources. The techniques comprising the CERTS Microgrid concept are: 1) a method for effecting automatic and seamless transitions between grid-connected and islanded modes of operation; 2) an approach to electrical protection within the microgrid that does not depend on highmore » fault currents; and 3) a method for microgrid control that achieves voltage and frequency stability under islanded conditions without requiring high-speed communications. The techniques were demonstrated at a full-scale test bed built near Columbus, Ohio and operated by American Electric Power. The testing fully confirmed earlier research that had been conducted initially through analytical simulations, then through laboratory emulations, and finally through factory acceptance testing of individual microgrid components. The islanding and resychronization method met all Institute of Electrical and Electronics Engineers 1547 and power quality requirements. The electrical protections system was able to distinguish between normal and faulted operation. The controls were found to be robust and under all conditions, including difficult motor starts. The results from these test are expected to lead to additional testing of enhancements to the basic techniques at the test bed to improve the business case for microgrid technologies, as well to field demonstrations involving microgrids that involve one or mroe of the CERTS Microgrid concepts.« less

Identification of Suitable Reference Genes for Gene Expression Normalization in qRT-PCR Analysis in Watermelon

PubMed Central

Gao, Lingyun; Zhao, Shuang; Jiang, Wei; Huang, Yuan; Bie, Zhilong

2014-01-01

Watermelon is one of the major Cucurbitaceae crops and the recent availability of genome sequence greatly facilitates the fundamental researches on it. Quantitative real-time reverse transcriptase PCR (qRT–PCR) is the preferred method for gene expression analyses, and using validated reference genes for normalization is crucial to ensure the accuracy of this method. However, a systematic validation of reference genes has not been conducted on watermelon. In this study, transcripts of 15 candidate reference genes were quantified in watermelon using qRT–PCR, and the stability of these genes was compared using geNorm and NormFinder. geNorm identified ClTUA and ClACT, ClEF1α and ClACT, and ClCAC and ClTUA as the best pairs of reference genes in watermelon organs and tissues under normal growth conditions, abiotic stress, and biotic stress, respectively. NormFinder identified ClYLS8, ClUBCP, and ClCAC as the best single reference genes under the above experimental conditions, respectively. ClYLS8 and ClPP2A were identified as the best reference genes across all samples. Two to nine reference genes were required for more reliable normalization depending on the experimental conditions. The widely used watermelon reference gene 18SrRNA was less stable than the other reference genes under the experimental conditions. Catalase family genes were identified in watermelon genome, and used to validate the reliability of the identified reference genes. ClCAT1and ClCAT2 were induced and upregulated in the first 24 h, whereas ClCAT3 was downregulated in the leaves under low temperature stress. However, the expression levels of these genes were significantly overestimated and misinterpreted when 18SrRNA was used as a reference gene. These results provide a good starting point for reference gene selection in qRT–PCR analyses involving watermelon. PMID:24587403

Identification of suitable reference genes for gene expression normalization in qRT-PCR analysis in watermelon.

PubMed

Kong, Qiusheng; Yuan, Jingxian; Gao, Lingyun; Zhao, Shuang; Jiang, Wei; Huang, Yuan; Bie, Zhilong

2014-01-01

Watermelon is one of the major Cucurbitaceae crops and the recent availability of genome sequence greatly facilitates the fundamental researches on it. Quantitative real-time reverse transcriptase PCR (qRT-PCR) is the preferred method for gene expression analyses, and using validated reference genes for normalization is crucial to ensure the accuracy of this method. However, a systematic validation of reference genes has not been conducted on watermelon. In this study, transcripts of 15 candidate reference genes were quantified in watermelon using qRT-PCR, and the stability of these genes was compared using geNorm and NormFinder. geNorm identified ClTUA and ClACT, ClEF1α and ClACT, and ClCAC and ClTUA as the best pairs of reference genes in watermelon organs and tissues under normal growth conditions, abiotic stress, and biotic stress, respectively. NormFinder identified ClYLS8, ClUBCP, and ClCAC as the best single reference genes under the above experimental conditions, respectively. ClYLS8 and ClPP2A were identified as the best reference genes across all samples. Two to nine reference genes were required for more reliable normalization depending on the experimental conditions. The widely used watermelon reference gene 18SrRNA was less stable than the other reference genes under the experimental conditions. Catalase family genes were identified in watermelon genome, and used to validate the reliability of the identified reference genes. ClCAT1and ClCAT2 were induced and upregulated in the first 24 h, whereas ClCAT3 was downregulated in the leaves under low temperature stress. However, the expression levels of these genes were significantly overestimated and misinterpreted when 18SrRNA was used as a reference gene. These results provide a good starting point for reference gene selection in qRT-PCR analyses involving watermelon.

Long-period gratings in photonic crystal fibers operating near the phase-matching turning point for evanescent chemical and biochemical sensing

NASA Astrophysics Data System (ADS)

Kanka, Jiri

2012-06-01

Fiber-optic long-period grating (LPG) operating near the dispersion turning point in its phase matching curve (PMC), referred to as a Turn Around Point (TAP) LPG, is known to be extremely sensitive to external parameters. Moreover, in a TAP LPG the phase matching condition can be almost satisfied over large spectral range, yielding a broadband LPG operation. TAP LPGs have been investigated, namely for use as broadband mode convertors and biosensors. So far TAP LPGs have been realized in specially designed or post-processed conventional fibers, not yet in PCFs, which allow a great degree of freedom in engineering the fiber's dispersion properties through the control of the PCF structural parameters. We have developed the design optimization technique for TAP PCF LPGs employing the finite element method for PCF modal analysis in a combination with the Nelder-Mead simplex method for minimizing the objective function based on target-specific PCF properties. Using this tool we have designed TAP PCF LPGs for specified wavelength ranges and refractive indices of medium in the air holes. Possible TAP PCF-LPG operational regimes - dual-resonance, broadband mode conversion and transmitted intensity-based operation - will be demonstrated numerically. Potential and limitations of TAP PCF-LPGs for evanescent chemical and biochemical sensing will be assessed.

Identification of a Novel Reference Gene for Apple Transcriptional Profiling under Postharvest Conditions

PubMed Central

Storch, Tatiane Timm; Pegoraro, Camila; Finatto, Taciane; Quecini, Vera; Rombaldi, Cesar Valmor; Girardi, César Luis

2015-01-01

Reverse Transcription quantitative PCR (RT-qPCR) is one of the most important techniques for gene expression profiling due to its high sensibility and reproducibility. However, the reliability of the results is highly dependent on data normalization, performed by comparisons between the expression profiles of the genes of interest against those of constitutively expressed, reference genes. Although the technique is widely used in fruit postharvest experiments, the transcription stability of reference genes has not been thoroughly investigated under these experimental conditions. Thus, we have determined the transcriptional profile, under these conditions, of three genes commonly used as reference—ACTIN (MdACT), PROTEIN DISULPHIDE ISOMERASE (MdPDI) and UBIQUITIN-CONJUGATING ENZYME E2 (MdUBC)—along with two novel candidates—HISTONE 1 (MdH1) and NUCLEOSSOME ASSEMBLY 1 PROTEIN (MdNAP1). The expression profile of the genes was investigated throughout five experiments, with three of them encompassing the postharvest period and the other two, consisting of developmental and spatial phases. The transcriptional stability was comparatively investigated using four distinct software packages: BestKeeper, NormFinder, geNorm and DataAssist. Gene ranking results for transcriptional stability were similar for the investigated software packages, with the exception of BestKeeper. The classic reference gene MdUBC ranked among the most stably transcribed in all investigated experimental conditions. Transcript accumulation profiles for the novel reference candidate gene MdH1 were stable throughout the tested conditions, especially in experiments encompassing the postharvest period. Thus, our results present a novel reference gene for postharvest experiments in apple and reinforce the importance of checking the transcription profile of reference genes under the experimental conditions of interest. PMID:25774904

40 CFR 63.1330 - Wastewater provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... through 63.149. (i) When §§ 63.132 through 63.149 refer to table 8 compounds, the owner or operator is....149 refer to table 9 compounds, the owner or operator is only required to consider compounds that meet the definition of organic HAP in § 63.1312 and that are listed on table 9 of 40 CFR part 63, subpart G...

40 CFR 63.1330 - Wastewater provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... through 63.149. (i) When §§ 63.132 through 63.149 refer to table 8 compounds, the owner or operator is....149 refer to table 9 compounds, the owner or operator is only required to consider compounds that meet the definition of organic HAP in § 63.1312 and that are listed on table 9 of 40 CFR part 63, subpart G...

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.

Theoretical features of MHD equilibria with flow

NASA Astrophysics Data System (ADS)

Beklemishev, Alexei; Tessarotto, Massimo

2002-11-01

The effect produced on plasma dynamics by plasma flows, especially those produced by strong E× B-drifts represent an important theoretical issue in magnetic confinement. These include in particular Stellarator equilibria in the presence of weak flows, with velocity much smaller in magnitude than the ion thermal velocity [1]. Strong flows, however, more generally can be produced locally in a variety of physical situations (for example due to strong radial electric fields, neutral beams, RF heating, etc.). These flows can be important in establishing advanced operational regimes, such as the recently discovered HDH mode in the W7-AS Stellarator [2]. Goal of this work is to investigate theoretical features of the MHD equilibria in the presence of strong flows, with particular reference to conditions of existence of kinetic equilibria, particle adiabatic and/or bounce-averaged invariants. References 1 - M. Tessarotto, J.L. Johnson, R.B. White and L.J. Zheng, Phys. Plasmas 3, 2653 (1996); 2 - K. McCormick et al., Phys. Rev. Lett. 89, 15001 (2002).

Potential Offshore Wind Energy Areas in California: An Assessment of Locations, Technology, and Costs

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

Musial, Walter; Beiter, Philipp; Tegen, Suzanne

This report summarizes a study of possible offshore wind energy locations, technologies, and levelized cost of energy in the state of California between 2015 and 2030. The study was funded by the U.S. Department of the Interior's Bureau of Ocean Energy Management (BOEM), the federal agency responsible for regulating renewable energy development on the Outer Continental Shelf. It is based on reference wind energy areas where representative technology and performance characteristics were evaluated. These reference areas were identified as sites that were suitable to represent offshore wind cost and technology based on physical site conditions, wind resource quality, known existingmore » site use, and proximity to necessary infrastructure. The purpose of this study is to assist energy policy decision-making by state utilities, independent system operators, state government officials and policymakers, BOEM, and its key stakeholders. The report is not intended to serve as a prescreening exercise for possible future offshore wind development.« less

Adaptive PIF Control for Permanent Magnet Synchronous Motors Based on GPC

PubMed Central

Lu, Shaowu; Tang, Xiaoqi; Song, Bao

2013-01-01

To enhance the control performance of permanent magnet synchronous motors (PMSMs), a generalized predictive control (GPC)-based proportional integral feedforward (PIF) controller is proposed for the speed control system. In this new approach, firstly, based on the online identification of controlled model parameters, a simplified GPC law supplies the PIF controller with suitable control parameters according to the uncertainties in the operating conditions. Secondly, the speed reference curve for PMSMs is usually required to be continuous and continuously differentiable according to the general servo system design requirements, so the adaptation of the speed reference is discussed in details in this paper. Hence, the performance of the speed control system using a GPC-based PIF controller is improved for tracking some specified signals. The main motivation of this paper is the extension of GPC law to replace the traditional PI or PIF controllers in industrial applications. The efficacy and usefulness of the proposed controller are verified through experimental results. PMID:23262481

Adaptive PIF control for permanent magnet synchronous motors based on GPC.

PubMed

Lu, Shaowu; Tang, Xiaoqi; Song, Bao

2012-12-24

To enhance the control performance of permanent magnet synchronous motors (PMSMs), a generalized predictive control (GPC)-based proportional integral feedforward (PIF) controller is proposed for the speed control system. In this new approach, firstly, based on the online identification of controlled model parameters, a simplified GPC law supplies the PIF controller with suitable control parameters according to the uncertainties in the operating conditions. Secondly, the speed reference curve for PMSMs is usually required to be continuous and continuously differentiable according to the general servo system design requirements, so the adaptation of the speed reference is discussed in details in this paper. Hence, the performance of the speed control system using a GPC-based PIF controller is improved for tracking some specified signals. The main motivation of this paper is the extension of GPC law to replace the traditional PI or PIF controllers in industrial applications. The efficacy and usefulness of the proposed controller are verified through experimental results.

Clinical and epidemiological aspects of cornea transplant patients of a reference hospital 1

PubMed Central

Cruz, Giovanna Karinny Pereira; de Azevedo, Isabelle Campos; Carvalho, Diana Paula de Souza Rego Pinto; Vitor, Allyne Fortes; Santos, Viviane Euzébia Pereira; Ferreira, Marcos Antonio

2017-01-01

ABSTRACT Objective: clinically characterizing cornea transplant patients and their distribution according to indicated and post-operative conditions of cornea transplantation, as well as estimating the average waiting time. Method: a cross-sectional, descriptive and analytical study performed for all cornea transplants performed at a reference service (n=258). Data were analyzed using Statistical Package for the Social Sciences, version 20.0. Results: the main indicator for cornea transplant was keratoconus. The mean waiting time for the transplant was approximately 5 months and 3 weeks for elective transplants and 9 days for urgent cases. An association between the type of corneal disorder with gender, age, previous surgery, eye classification, glaucoma and anterior graft failure were found. Conclusion: keratoconus was the main indicator for cornea transplant. Factors such as age, previous corneal graft failure (retransplantation), glaucoma, cases of surgeries prior to cornea transplant (especially cataract surgery) may be related to the onset corneal endothelium disorders. PMID:28614429

30 CFR 250.901 - What industry standards must your platform meet?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Structures for Hurricane Conditions, (as incorporated by reference in § 250.198); (5) API Bulletin 2INT-EX, Interim Guidance for Assessment of Existing Offshore Structures for Hurricane Conditions, (as incorporated by reference in § 250.198); (6) API Bulletin 2INT-MET, Interim Guidance on Hurricane Conditions in...

30 CFR 250.901 - What industry standards must your platform meet?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Structures for Hurricane Conditions, (as incorporated by reference in § 250.198); (5) API Bulletin 2INT-EX, Interim Guidance for Assessment of Existing Offshore Structures for Hurricane Conditions, (as incorporated by reference in § 250.198); (6) API Bulletin 2INT-MET, Interim Guidance on Hurricane Conditions in...

30 CFR 250.901 - What industry standards must your platform meet?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Structures for Hurricane Conditions, (as incorporated by reference in § 250.198); (5) API Bulletin 2INT-EX, Interim Guidance for Assessment of Existing Offshore Structures for Hurricane Conditions, (as incorporated by reference in § 250.198); (6) API Bulletin 2INT-MET, Interim Guidance on Hurricane Conditions in...

METHODS MODULE

EPA Science Inventory

The ultimate goal of classification is to reduce variation within classes to enable detection of differences between reference and impacted condition within classes as cost-effectively as possible, while minimizing the number of classes for which reference conditions must be defi...

Self-reference enhances relational memory in young and older adults.

PubMed

Hou, Mingzhu; Grilli, Matthew D; Glisky, Elizabeth L

2017-11-27

The present study investigated the influence of self-reference on two kinds of relational memory, internal source memory and associative memory, in young and older adults. Participants encoded object-location word pairs using the strategies of imagination and sentence generation, either with reference to themselves or to a famous other (i.e., George Clooney or Oprah Winfrey). Both young and older adults showed memory benefits in the self-reference conditions compared to other-reference conditions on both tests, and the self-referential effects in older adults were not limited by low memory or executive functioning. These results suggest that self-reference can benefit relational memory in older adults relatively independently of basic memory and executive functions.

Global daily reference evapotranspiration modeling and evaluation

USGS Publications Warehouse

Senay, G.B.; Verdin, J.P.; Lietzow, R.; Melesse, Assefa M.

2008-01-01

Accurate and reliable evapotranspiration (ET) datasets are crucial in regional water and energy balance studies. Due to the complex instrumentation requirements, actual ET values are generally estimated from reference ET values by adjustment factors using coefficients for water stress and vegetation conditions, commonly referred to as crop coefficients. Until recently, the modeling of reference ET has been solely based on important weather variables collected from weather stations that are generally located in selected agro-climatic locations. Since 2001, the National Oceanic and Atmospheric Administration’s Global Data Assimilation System (GDAS) has been producing six-hourly climate parameter datasets that are used to calculate daily reference ET for the whole globe at 1-degree spatial resolution. The U.S. Geological Survey Center for Earth Resources Observation and Science has been producing daily reference ET (ETo) since 2001, and it has been used on a variety of operational hydrological models for drought and streamflow monitoring all over the world. With the increasing availability of local station-based reference ET estimates, we evaluated the GDAS-based reference ET estimates using data from the California Irrigation Management Information System (CIMIS). Daily CIMIS reference ET estimates from 85 stations were compared with GDAS-based reference ET at different spatial and temporal scales using five-year daily data from 2002 through 2006. Despite the large difference in spatial scale (point vs. ∼100 km grid cell) between the two datasets, the correlations between station-based ET and GDAS-ET were very high, exceeding 0.97 on a daily basis to more than 0.99 on time scales of more than 10 days. Both the temporal and spatial correspondences in trend/pattern and magnitudes between the two datasets were satisfactory, suggesting the reliability of using GDAS parameter-based reference ET for regional water and energy balance studies in many parts of the world. While the study revealed the potential of GDAS ETo for large-scale hydrological applications, site-specific use of GDAS ETo in complex hydro-climatic regions such as coastal areas and rugged terrain may require the application of bias correction and/or disaggregation of the GDAS ETo using downscaling techniques.

Comparison of different incubation conditions for microbiological environmental monitoring.

PubMed

Gordon, Oliver; Berchtold, Manfred; Staerk, Alexandra; Roesti, David

2014-01-01

Environmental monitoring represents an integral part of the microbiological quality control system of a pharmaceutical manufacturing operation. However, guidance documents differ regarding recommendation of a procedure, particularly regarding incubation time, incubation temperature, or nutrient media. Because of these discrepancies, many manufacturers decide for a particular environmental monitoring sample incubation strategy and support this decision with validation data. Such validations are typically laboratory-based in vitro studies, meaning that these are based on comparing incubation conditions and nutrient media through use of cultured microorganisms. An informal survey of the results of these in vitro studies performed at Novartis or European manufacturing sites of different pharmaceutical companies highlighted that no consensus regarding the optimal incubation conditions for microbial recovery existed. To address this question differently, we collected a significant amount of samples directly from air, inanimate surfaces, and personnel in pharmaceutical production and packaging rooms during manufacturing operation (in situ study). Samples were incubated under different conditions suggested in regulatory guidelines, and recovery of total aerobic microorganisms as well as moulds was assessed. We found the highest recovery of total aerobic count from areas with personnel flow using a general microbiological growth medium incubated at 30-35 °C. The highest recovery of moulds was obtained with mycological medium incubated at 20-25 °C. Single-plate strategies (two-temperature incubation or an intermediate incubation temperature of 25-30 °C) also yielded reasonable recovery of total aerobic count and moulds. However, recovery of moulds was found to be highly inefficient at 30-35 °C compared to lower incubation temperatures. This deficiency could not be rectified by subsequent incubation at 20-25 °C. A laboratory-based in vitro study performed in parallel was inconclusive. We consider our results potentially conferrable to other pharmaceutical manufacturing sites in moderate climate zones and believe that these should represent a valuable reference for definition of the incubation strategy of microbiological environmental monitoring samples. Microbiological environmental monitoring confirms that pharmaceutical cleanrooms are in an appropriate hygienic condition for manufacturing of drug products. Guidance documents from different health authorities or expert groups differ regarding recommendation of the applied incubation time, incubation temperature, or nutrient media. Therefore, many pharmaceutical manufacturers perform studies that aim to identify the optimal incubation setup for environmental monitoring samples. An informal survey of the results of such studies, which had been performed at Novartis or European manufacturing sites of different pharmaceutical companies, highlighted no consensus regarding the optimal incubation conditions for microbial recovery. All these studies had been conducted in the laboratory using selections of cultured microbial strains. We tried to solve this disagreement by collecting a significant amount of real environmental monitoring samples directly from the environment in pharmaceutical production and packaging rooms during manufacturing operation. These samples were then incubated under different conditions suggested in the regulatory guidelines. We believe that the results of our study are more meaningful than laboratory-based experiments because we used environmental samples with microorganisms directly isolated from the manufacturing area. Therefore, we believe that our results should represent a valuable reference for definition of the incubation strategy of microbiological environmental monitoring samples. © PDA, Inc. 2014.

Battlefield radar imaging through airborne millimetric wave SAR (Synthetic Aperture Radar)

NASA Astrophysics Data System (ADS)

Carletti, U.; Daddio, E.; Farina, A.; Morabito, C.; Pangrazi, R.; Studer, F. A.

Airborne synthetic aperture radar (SAR), operating in the millimetric-wave (mmw) region, is discussed with reference to a battlefield surveillance application. The SAR system provides high resolution real-time imaging of the battlefield and moving target detection, under adverse environmental conditions (e.g., weather, dust, smoke, obscurants). The most relevant and original aspects of the system are the band of operation (i.e., mmw in lieu of the more traditional microwave region) and the use of an unmanned platform. The former implies reduced weight and size requirements, thus allowing use of small unmanned platforms. The latter enchances the system operational effectiveness by permitting accomplishment of recognition missions in depth beyond the FEBA. An overall system architecture based on the onboard sensor, the platform, the communication equipment, and a mobile ground station is described. The main areas of ongoing investigation are presented: the simulation of the end-to-end system, and the critical technological issues such as mmw antenna, transmitter, signal processor for image formation and platform attitude errors compensation and detection and imaging of moving targets.

Merged and corrected 915 MHz Radar Wind Profiler moments

DOE Data Explorer

Jonathan Helmus,Virendra Ghate, Frederic Tridon

2014-06-25

The radar wind profiler (RWP) present at the SGP central facility operates at 915 MHz and was reconfigured in early 2011, to collect key sets of measurements for precipitation and boundary layer studies. The RWP is configured to run in two main operating modes: a precipitation (PR) mode with frequent vertical observations and a boundary layer (BL) mode that is similar to what has been traditionally applied to RWPs. To address issues regarding saturation of the radar signal, range resolution and maximum range, the RWP PR mode is set to operate with two different pulse lengths, termed as short pulse (SP) and long pulse (LP). Please refer to the RWP handbook (Coulter, 2012) for further information. Data from the RWP PR-SP and PR-LP modes have been extensively used to study deep precipitating clouds, especially their dynamical structure as the RWP data does not suffer from signal attenuation during these conditions (Giangrande et al., 2013). Tridon et al. (2013) used the data collected during the Mid-latitude Continental Convective Cloud Experiment (MC3E) to improve the estimation of noise floor of the RWP recorded Doppler spectra.

Experimental validation of a self-calibrating cryogenic mass flowmeter

NASA Astrophysics Data System (ADS)

Janzen, A.; Boersch, M.; Burger, B.; Drache, J.; Ebersoldt, A.; Erni, P.; Feldbusch, F.; Oertig, D.; Grohmann, S.

2017-12-01

The Karlsruhe Institute of Technology (KIT) and the WEKA AG jointly develop a commercial flowmeter for application in helium cryostats. The flowmeter functions according to a new thermal measurement principle that eliminates all systematic uncertainties and enables self-calibration during real operation. Ideally, the resulting uncertainty of the measured flow rate is only dependent on signal noises, which are typically very small with regard to the measured value. Under real operating conditions, cryoplant-dependent flow rate fluctuations induce an additional uncertainty, which follows from the sensitivity of the method. This paper presents experimental results with helium at temperatures between 30 and 70 K and flow rates in the range of 4 to 12 g/s. The experiments were carried out in a control cryostat of the 2 kW helium refrigerator of the TOSKA test facility at KIT. Inside the cryostat, the new flowmeter was installed in series with a Venturi tube that was used for reference measurements. The measurement results demonstrate the self-calibration capability during real cryoplant operation. The influences of temperature and flow rate fluctuations on the self-calibration uncertainty are discussed.

Fuel conservation evaluation of US (United States) Army helicopters. Part 4. OH-58C flight testing. Final report 22 Sep 20-Nov 82

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

Belte, D.; Stratton, M.V.

1982-08-01

The United States Army Aviation Engineering Flight Activity conducted level flight performance tests of the OH-58C helicopter at Edwards AFB, California from 22 September to 20 November 1981, and at St. Paul, Minnesota, from 12 January to 9 February 1982. Nondimensional methods were used to identify effects of compressibility and blade stall on performance, and increased referred rotor speeds were used to supplement the range of currently available level flight data. Maximum differences in nondimensional power required attributed to compressibility effects varied from 6.5 to 11%. However, high actual rotor speed at a given condition can result in less powermore » required than at low rotor speed even with the compressibility penalty. The power required characteristics determined by these tests can be combined with engine performance to determine the most fuel efficient operating conditions.« less

Rural sewage treatment processing in Yongjia County, Zhejiang Province

NASA Astrophysics Data System (ADS)

Wang, W. H.; Kuan, T. H.

2016-08-01

Issues regarding water pollution in rural areas of China have garnered increased attention over the years. Further discussion on the circumstances and results of existing domestic sewage treatment methods may serve as an appropriate reference in solving these important issues. This article explored the current conditions of water contamination in rural areas of China, introduced the characteristics and effects of applicable sewage treatment technology, and summarized the results of the planning, installation, and operation of rural sewage treatment facilities in Yongjia County in Zhejiang Province. However, relying on a single technical design rule is not adequate for solving the practical problems that these villages face. Instead, methods of planning rural sewage treatment should be adapted to better suit local conditions and different residential forms. It is crucial, ultimately, for any domestic sewage treatment system in a rural area to be commissioned, engineered, and maintained by a market-oriented professional company.

Advances in Meningeal Immunity.

PubMed

Rua, Rejane; McGavern, Dorian B

2018-06-01

The central nervous system (CNS) is an immunologically specialized tissue protected by a blood-brain barrier. The CNS parenchyma is enveloped by a series of overlapping membranes that are collectively referred to as the meninges. The meninges provide an additional CNS barrier, harbor a diverse array of resident immune cells, and serve as a crucial interface with the periphery. Recent studies have significantly advanced our understanding of meningeal immunity, demonstrating how a complex immune landscape influences CNS functions under steady-state and inflammatory conditions. The location and activation state of meningeal immune cells can profoundly influence CNS homeostasis and contribute to neurological disorders, but these cells are also well equipped to protect the CNS from pathogens. In this review, we discuss advances in our understanding of the meningeal immune repertoire and provide insights into how this CNS barrier operates immunologically under conditions ranging from neurocognition to inflammatory diseases. Published by Elsevier Ltd.

Numerical analysis of the effects induced by normal faults and dip angles on rock bursts

NASA Astrophysics Data System (ADS)

Jiang, Lishuai; Wang, Pu; Zhang, Peipeng; Zheng, Pengqiang; Xu, Bin

2017-10-01

The study of mining effects under the influences of a normal fault and its dip angle is significant for the prediction and prevention of rock bursts. Based on the geological conditions of panel 2301N in a coalmine, the evolution laws of the strata behaviors of the working face affected by a fault and the instability of the fault induced by mining operations with the working face of the footwall and hanging wall advancing towards a normal fault are studied using UDEC numerical simulation. The mechanism that induces rock burst is revealed, and the influence characteristics of the fault dip angle are analyzed. The results of the numerical simulation are verified by conducting a case study regarding the microseismic events. The results of this study serve as a reference for the prediction of rock bursts and their classification into hazardous areas under similar conditions.

Acoustic Radiation from High-Speed Turbulent Boundary Layers in a Tunnel-Like Environment

NASA Technical Reports Server (NTRS)

Duan, Lian; Choudhari, Meelan M.; Zhang, Chao

2015-01-01

Direct numerical simulation of acoustic radiation from a turbulent boundary layer in a cylindrical domain will be conducted under the flow conditions corresponding to those at the nozzle exit of the Boeing/AFOSR Mach-6 Quiet Tunnel (BAM6QT) operated under noisy-flow conditions with a total pressure p(sub t) of 225 kPa and a total temperature of T(sub t) equal to 430 K. Simulations of acoustic radiation from a turbulent boundary layer over a flat surface are used as a reference configuration to illustrate the effects of the cylindrical enclosure. A detailed analysis of acoustic freestream disturbances in the cylindrical domain will be reported in the final paper along with a discussion pertaining to the significance of the flat-plate acoustic simulations and guidelines concerning the modeling of the effects of an axisymmetric tunnel wall on the noise field.

Thermal Performance Comparison of Glass Microsphere and Perlite Insulation Systems for Liquid Hydrogen Storage Tanks

NASA Astrophysics Data System (ADS)

Sass, J. P.; Fesmire, J. E.; Nagy, Z. F.; Sojourner, S. J.; Morris, D. L.; Augustynowicz, S. D.

2008-03-01

A technology demonstration test project was conducted by the Cryogenics Test Laboratory at the Kennedy Space Center (KSC) to provide comparative thermal performance data for glass microspheres, referred to as bubbles, and perlite insulation for liquid hydrogen tank applications. Two identical 1/15th scale versions of the 3,200,000 liter spherical liquid hydrogen tanks at Launch Complex 39 at KSC were custom designed and built to serve as test articles for this test project. Evaporative (boil-off) calorimeter test protocols, including liquid nitrogen and liquid hydrogen, were established to provide tank test conditions characteristic of the large storage tanks that support the Space Shuttle launch operations. This paper provides comparative thermal performance test results for bubbles and perlite for a wide range of conditions. Thermal performance as a function of cryogenic commodity (nitrogen and hydrogen), vacuum pressure, insulation fill level, tank liquid level, and thermal cycles will be presented.

How Explicit and Implicit Test Instructions in an Implicit Learning Task Affect Performance

PubMed Central

Witt, Arnaud; Puspitawati, Ira; Vinter, Annie

2013-01-01

Typically developing children aged 5 to 8 years were exposed to artificial grammar learning. Following an implicit exposure phase, half of the participants received neutral instructions at test while the other half received instructions making a direct, explicit reference to the training phase. We first aimed to assess whether implicit learning operated in the two test conditions. We then evaluated the differential impact of age on learning performances as a function of test instructions. The results showed that performance did not vary as a function of age in the implicit instructions condition, while age effects emerged when explicit instructions were employed at test. However, performance was affected differently by age and the instructions given at test, depending on whether the implicit learning of short or long units was assessed. These results suggest that the claim that the implicit learning process is independent of age needs to be revised. PMID:23326409

An Analytical Time–Domain Expression for the Net Ripple Produced by Parallel Interleaved Converters

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

Johnson, Brian B.; Krein, Philip T.

We apply modular arithmetic and Fourier series to analyze the superposition of N interleaved triangular waveforms with identical amplitudes and duty-ratios. Here, interleaving refers to the condition when a collection of periodic waveforms with identical periods are each uniformly phase-shifted across one period. The main result is a time-domain expression which provides an exact representation of the summed and interleaved triangular waveforms, where the peak amplitude and parameters of the time-periodic component are all specified in closed-form. Analysis is general and can be used to study various applications in multi-converter systems. This model is unique not only in that itmore » reveals a simple and intuitive expression for the net ripple, but its derivation via modular arithmetic and Fourier series is distinct from prior approaches. The analytical framework is experimentally validated with a system of three parallel converters under time-varying operating conditions.« less

High Fidelity CFD Analysis and Validation of Rotorcraft Gearbox Aerodynamics Under Operational and Oil-Out Conditions

NASA Technical Reports Server (NTRS)

Kunz, Robert F.

2014-01-01

This document represents the evolving formal documentation of the NPHASE-PSU computer code. Version 3.15 is being delivered along with the software to NASA in 2013.Significant upgrades to the NPHASE-PSU have been made since the first delivery of draft documentation to DARPA and USNRC in 2006. These include a much lighter, faster and memory efficient face based front end, support for arbitrary polyhedra in front end, flow-solver and back-end, a generalized homogeneous multiphase capability, and several two-fluid modelling and algorithmic elements. Specific capability installed for the NASA Gearbox Windage Aerodynamics NRA are included in this version: Hybrid Immersed Overset Boundary Method (HOIBM) [Noack et. al (2009)] Periodic boundary conditions for multiple frames of reference, Fully generalized immersed boundary method, Fully generalized conjugate heat transfer, Droplet deposition, bouncing, splashing models, and, Film transport and breakup.

Operator assistant to support deep space network link monitor and control

NASA Technical Reports Server (NTRS)

Cooper, Lynne P.; Desai, Rajiv; Martinez, Elmain

1992-01-01

Preparing the Deep Space Network (DSN) stations to support spacecraft missions (referred to as pre-cal, for pre-calibration) is currently an operator and time intensive activity. Operators are responsible for sending and monitoring several hundred operator directivities, messages, and warnings. Operator directives are used to configure and calibrate the various subsystems (antenna, receiver, etc.) necessary to establish a spacecraft link. Messages and warnings are issued by the subsystems upon completion of an operation, changes of status, or an anomalous condition. Some points of pre-cal are logically parallel. Significant time savings could be realized if the existing Link Monitor and Control system (LMC) could support the operator in exploiting the parallelism inherent in pre-cal activities. Currently, operators may work on the individual subsystems in parallel, however, the burden of monitoring these parallel operations resides solely with the operator. Messages, warnings, and directives are all presented as they are received; without being correlated to the event that triggered them. Pre-cal is essentially an overhead activity. During pre-cal, no mission is supported, and no other activity can be performed using the equipment in the link. Therefore, it is highly desirable to reduce pre-cal time as much as possible. One approach to do this, as well as to increase efficiency and reduce errors, is the LMC Operator Assistant (OA). The LMC OA prototype demonstrates an architecture which can be used in concert with the existing LMC to exploit parallelism in pre-cal operations while providing the operators with a true monitoring capability, situational awareness and positive control. This paper presents an overview of the LMC OA architecture and the results from initial prototyping and test activities.

SLS-SPEC-159 Cross-Program Design Specification for Natural Environments (DSNE) Revision D

NASA Technical Reports Server (NTRS)

Roberts, Barry C.

2015-01-01

This document is derived from the former National Aeronautics and Space Administration (NASA) Constellation Program (CxP) document CxP 70023, titled "The Design Specification for Natural Environments (DSNE), Revision C." The original document has been modified to represent updated Design Reference Missions (DRMs) for the NASA Exploration Systems Development (ESD) Programs. The DSNE completes environment-related specifications for architecture, system-level, and lower-tier documents by specifying the ranges of environmental conditions that must be accounted for by NASA ESD Programs. To assure clarity and consistency, and to prevent requirements documents from becoming cluttered with extensive amounts of technical material, natural environment specifications have been compiled into this document. The intent is to keep a unified specification for natural environments that each Program calls out for appropriate application. This document defines the natural environments parameter limits (maximum and minimum values, energy spectra, or precise model inputs, assumptions, model options, etc.), for all ESD Programs. These environments are developed by the NASA Marshall Space Flight Center (MSFC) Natural Environments Branch (MSFC organization code: EV44). Many of the parameter limits are based on experience with previous programs, such as the Space Shuttle Program. The parameter limits contain no margin and are meant to be evaluated individually to ensure they are reasonable (i.e., do not apply unrealistic extreme-on-extreme conditions). The natural environments specifications in this document should be accounted for by robust design of the flight vehicle and support systems. However, it is understood that in some cases the Programs will find it more effective to account for portions of the environment ranges by operational mitigation or acceptance of risk in accordance with an appropriate program risk management plan and/or hazard analysis process. The DSNE is not intended as a definition of operational models or operational constraints, nor is it adequate, alone, for ground facilities which may have additional requirements (for example, building codes and local environmental constraints). "Natural environments," as the term is used here, refers to the environments that are not the result of intended human activity or intervention. It consists of a variety of external environmental factors (most of natural origin and a few of human origin) which impose restrictions or otherwise impact the development or operation of flight vehicles and destination surface systems. These natural environments include the following types of environments: Terrestrial environments at launch, abort, and normal landing sites (winds, temperatures, pressures, surface roughness, sea conditions, etc.); Space environments (ionizing radiation, orbital debris, meteoroids, thermosphere density, plasma, solar, Earth, and lunar-emitted thermal radiation, etc.); Destination environments (Lunar surface and orbital, Mars atmosphere and surface, near Earth asteroids, etc.). Many of the environmental specifications in this document are based on models, data, and environment descriptions contained in the CxP 70044, Constellation Program Natural Environment Definition for Design (NEDD). The NEDD provides additional detailed environment data and model descriptions to support analytical studies for ESD Programs. For background information on specific environments and their effects on spacecraft design and operations, the environment models, and the data used to generate the specifications contained in the DSNE, the reader is referred to the NEDD paragraphs listed in each section of the DSNE. Also, most of the environmental specifications in this document are tied specifically to the ESD DRMs in ESD-10012, Revision B, Exploration Systems Development Concept of Operations (ConOps). Coordination between these environment specifications and the DRMs must be maintained. This document should be compatible with the current ESD DRMs, but updates to the mission definitions and variations in interpretation may require adjustments to the environment specifications.

Workload: Measurement and Management

NASA Technical Reports Server (NTRS)

Gore, Brian Francis; Casner, Stephen

2010-01-01

Poster: The workload research project has as its task to survey the available literature on: (1) workload measurement techniques; and (2) the effects of workload on operator performance. The first set of findings provides practitioners with a collection of simple-to-use workload measurement techniques along with characterizations of the kinds of tasks each technique has been shown reliably address. This allows design practitioners to select and use the most appropriate techniques for the task(s) at hand. The second set of findings provides practitioners with the guidance they need to design for appropriate kinds and amounts of workload across all tasks for which the operator is responsible. This guidance helps practitioners design systems and procedures that ensure appropriate levels of engagement across all tasks, and avoid designs and procedures that result in operator boredom, complacency, loss of awareness, undue levels of stress, or skill atrophy that can result from workload that distracts operators from the tasks they perform and monitor, workload levels that are too low, too high, or too consistent or predictable. Only those articles that were peer reviewed, long standing and generally accepted in the field, and applicable to a relevant range of conditions in a select domain of interest, in analogous "extreme" environments to those in space were included. In addition, all articles were reviewed and evaluated on uni-dimensional and multi-dimensional considerations. Casner & Gore also examined the notion of thresholds and the conditions that may benefit mostly from the various methodological approaches. Other considerations included whether the tools would be suitable for guiding a requirement-related and design-related question. An initial review of over 225 articles was conducted and entered into an EndNote database. The reference list included a range of conditions in the domain of interest (subjective/objective measures), the seminal works in workload, as well as summary works

A Reusable Design for Precision Lunar Landing Systems

NASA Technical Reports Server (NTRS)

Fuhrman, Linda; Brand, Timothy; Fill, Tom; Norris, Lee; Paschall, Steve

2005-01-01

The top-level architecture to accomplish NASA's Vision for Space Exploration is to use Lunar missions and systems not just as an end in themselves, but also as testbeds for the more ambitious goals of Human Mars Exploration (HME). This approach means that Lunar missions and systems are most likely going to be targeted for (Lunar) polar missions, and also for long-duration (months) surface stays. This overacting theme creates basic top-level requirements for any next-generation lander system: 1) Long duration stays: a) Multiple landers in close proximity; b) Pinpoint landings for "surface rendezvous"; c) Autonomous landing of pre-positioned assets; and d) Autonomous Hazard Detection and Avoidance. 2) Polar and deep-crater landings (dark); 3) Common/extensible systems for Moon and Mars, crew and cargo. These requirements pose challenging technology and capability needs. Compare and contrast: 4) Apollo: a) 1 km landing accuracy; b) Lunar near-side (well imaged and direct-to-Earth com. possible); c) Lunar equatorial (landing trajectories offer best navigation support from Earth); d) Limited lighting conditions; e) Significant ground-in-the-loop operations; 5) Lunar Access: a) 10-100m landing precision; b) "Anywhere" access includes polar (potentially poor nav. support from Earth) and far side (poor gravity and imaging; no direct-to-Earth com); c) "Anytime" access includes any lighting condition (including dark); d) Full autonomous landing capability; e) Extensible design for tele-operation or operator-in-the-loop; and f) Minimal ground support to reduce operations costs. The Lunar Access program objectives, therefore, are to: a) Develop a baseline Lunar Precision Landing System (PLS) design to enable pinpoint "anywhere, anytime" landings; b) landing precision 10m-100m; c) Any LAT, LON; and d) Any lighting condition; This paper will characterize basic features of the next generation Lunar landing system, including trajectory types, sensor suite options and a reference system architecture.

Evaluation and improvement of the efficiency of the Seidel humeral nail by numerical-experimental analysis of the bone-implant contact.

PubMed

Giudice, Fabio; La Rosa, Guido; Russo, Tullio; Varsalona, Roberto

2006-09-01

Seidel intramedullary humeral nail is locked distally by a spreading device and proximally by transverse cross locking screws. The main problems found in its use are: the loosening of the distal anchorage, even after X-ray verification of the correct expansion of the device; the formation of distal fractures, occurring even 1 month after the operation; the system's low stability. The problems noted can be ascribed to the behaviour of the spreading device for distal fixing. The present study, therefore, was directed at analysing the contact between the spreading mechanism and the medullary canal in relation to the geometric parameters of the mechanism itself. The main objective was to define the correct regulation of the expansion in the operating theatre, and to delimit the more appropriate conditions of use, allowing the surgeon to evaluate the suitability of this particular device for the type of fracture under treatment. Numerical and experimental techniques were used to perform an analysis of the implant behaviour. This investigation, referred to immediate post-operative condition, allowed to evaluate the stability to traction of the system, to define the typology and properties of the bone-implant contact zone and to quantify the stresses produced, all as a function of the parameter on which the surgeon intervenes in the operating theatre: the number of turns used to tighten the spreading screw. The results obtained confirm and explain the disadvantages associated with the distal expansion system: the bone-implant contact turns out to be inefficient, as revealed by the distribution of the pressure on the inner wall of the medullary canal. On the basis of the results, it is possible to define the optimal conditions of use of the nail, and to formulate a simple solution for the improvement of its performance.

Evaluation and selection of reliable reference genes for gene expression under abiotic stress in cotton (Gossypium hirsutum L.).

PubMed

Wang, Min; Wang, Qinglian; Zhang, Baohong

2013-11-01

Reference genes are critical for normalization of the gene expression level of target genes. The widely used housekeeping genes may change their expression levels at different tissue under different treatment or stress conditions. Therefore, systematical evaluation on the housekeeping genes is required for gene expression analysis. Up to date, no work was performed to evaluate the housekeeping genes in cotton under stress treatment. In this study, we chose 10 housekeeping genes to systematically assess their expression levels at two different tissues (leaves and roots) under two different abiotic stresses (salt and drought) with three different concentrations. Our results show that there is no best reference gene for all tissues at all stress conditions. The reliable reference gene should be selected based on a specific condition. For example, under salt stress, UBQ7, GAPDH and EF1A8 are better reference genes in leaves; TUA10, UBQ7, CYP1, GAPDH and EF1A8 were better in roots. Under drought stress, UBQ7, EF1A8, TUA10, and GAPDH showed less variety of expression level in leaves and roots. Thus, it is better to identify reliable reference genes first before performing any gene expression analysis. However, using a combination of housekeeping genes as reference gene may provide a new strategy for normalization of gene expression. In this study, we found that combination of four housekeeping genes worked well as reference genes under all the stress conditions. © 2013.

A Centralized, Web-Based Annual Training and Certification Program for a Decentralized Adjutant General Corps Will Improve the Level of Human Resources Proficiency for Human Resources Professionals in the U.S. Active Army, U.S. Army Reserve and U.S. National Guard Components

DTIC Science & Technology

2009-12-11

66  Army eLearning ............................................................................................................ 67  AG...support Army transformation” and potential Overseas Contingency Operations (OCO), previously referred to as the Global War on Terror, with high...Operations, formerly referred to as the Global War on Terror, in two theaters has been 53 difficult due to high operational tempos. Mentorship under PSDR

Advanced Transport Operating System (ATOPS) control display unit software description

NASA Technical Reports Server (NTRS)

Slominski, Christopher J.; Parks, Mark A.; Debure, Kelly R.; Heaphy, William J.

1992-01-01

The software created for the Control Display Units (CDUs), used for the Advanced Transport Operating Systems (ATOPS) project, on the Transport Systems Research Vehicle (TSRV) is described. Module descriptions are presented in a standardized format which contains module purpose, calling sequence, a detailed description, and global references. The global reference section includes subroutines, functions, and common variables referenced by a particular module. The CDUs, one for the pilot and one for the copilot, are used for flight management purposes. Operations performed with the CDU affects the aircraft's guidance, navigation, and display software.

Manual discrimination of force

NASA Technical Reports Server (NTRS)

Pang, Xiao-Dong; Tan, HONG-Z.; Durlach, Nathaniel I.

1991-01-01

Optimal design of human-machine interfaces for teleoperators and virtual-environment systems which involve the tactual and kinesthetic modalities requires knowledge of the human's resolving power in these modalities. The resolution of the interface should be appropriately matched to that of the human operator. We report some preliminary results on the ability of the human hand to distinguish small differences in force under a variety of conditions. Experiments were conducted on force discrimination with the thumb pushing an interface that exerts a constant force over the pushing distance and the index finger pressing against a fixed support. The dependence of the sensitivity index d' on force increment can be fit by a straight line through the origin and the just-noticeable difference (JND) in force can thus be described by the inverse of the slope of this line. The receiver operating characteristic (ROC) was measured by varying the a priori probabilities of the two alternatives, reference force and reference force plus an increment, in one-interval, two-alternative, forced-choice experiments. When plotted on normal deviate coordinates, the ROC's were roughly straight lines of unit slope, thus supporting the assumption of equal-variance normal distributions and the use of the conventional d' measure. The JND was roughly 6-8 percent for reference force ranging from 2.5 to 10 newtons, pushing distance from 5 to 30 mm, and initial finger-span from 45 to 125 mm. Also, the JND remained the same when the subjects were instructed to change the average speed of pushing from 23 to 153 mm/sec. The pushing was terminated by reaching either a wall or a well, and the JND's were essentially the same in both cases.

Age Induced Effects on ESD Characteristics of Solar Array Coupons After Combined Space Environmental Exposures

NASA Technical Reports Server (NTRS)

Wright, Kenneth H.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Funderburk, Victor V.; Wong, Frankie; Gardiner, George

2012-01-01

A set of multi-junction GaAs/Ge solar array test coupons provided by Space Systems/Loral were subjected to a sequence of 5-year increments of combined space environment exposure tests. The test coupons capture an integrated design intended for use in a geosynchronous (GEO) space environment. A key component of this test campaign is performing electrostatic discharge (ESD) tests in the inverted gradient mode. The protocol of the ESD tests is based on the ISO standard for ESD testing on solar array panels [ISO-11221]. The test schematic in the ISO reference has been modified with Space System/Loral designed circuitry to better simulate the on-orbit operational conditions of its solar array design. Part of the modified circuitry is to simulate a solar array panel coverglass flashover discharge. All solar array coupons used in the test campaign consist of four cells constructed to form two strings. The ESD tests were performed at the beginning-of-life (BOL) and at each 5-year environment exposure point until end-of-life (EOL) at 15 years. The space environmental exposure sequence consisted of ultra-violet radiation, electron/proton particle radiation, thermal cycling, and Xenon ion thruster plume erosion. This paper describes the ESD test setup and the importance of the electrical test design in simulating the on-orbit operational conditions. Arc inception voltage results along with ESD test behavior from the BOL condition through the 15th year age condition are discussed. In addition, results from a Xenon plasma plume exposure test with an EOL coupon under the full ESD test condition will be discussed.

Macro- and micro- geodynamic of Terebliya-Riksk geodetic man-caused polygon of Ukrainian Carpathians influenced by specificities of structure-geological and hydro-geological conditions

NASA Astrophysics Data System (ADS)

Kulchyzkyy, A.; Serebryannyy, Y.; Tretyak, K.; Trevogo, I.; Zadoroznnyy, V.

2009-04-01

Terebliya-Riksk diversion power station is located on two levels ( with difference of 180m ) of south mountainside of Ukrainian Carpathians and separate parts of this power station lie inside rock. Therefore influential parameters of it's stability are geological, tectonic and hydrogeological conditions in complex. Monitoring of intensity and nature of displacements of flow ( pressure) pipe and other objects of power station with geoditic methods indicates that fluctuations of water-level in reservoir caused bouth by natural and artificial efects are of great influence on objects mentioned. Based on geodetical high-precision observations made by LeicaTPS 1201 robotic total station short-periodic components of fundamental vibrations which result in their destructive deformation were determined. Mathematical apparatus ( which uses function of Fourie series and theory of cinematic coefficients ) for displacements determinations of pressure pipe was disigned. Complex of engineering-geological surveys gave an opportunity to define the origin of macro- and micro- geodynamics movements of Terebliya-Riksk diversion power station region. Engineering-geological conditions which influence on power station structure most of all were determined as following : small foldings and cleavage areas appearances, also fluctuations of level of underground water (refered to hydrogeological conditions). Periodic micro-displacemets appearances ( which operate on reducing-stretching scheme) fixed on power station structure are turned to be in direct relation on to what exend reservoir is filled up. Permanent macro- displacements appearances ( which operates in north-west direction ) fixed on pressure pipe are the result sum of residual micro-displacements caused by return periodic movements and are determined by structure-geological, engineering-geological and tectonic conditions.

A New Framework for Quantifying Lidar Uncertainty

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

Newman, Jennifer, F.; Clifton, Andrew; Bonin, Timothy A.

2017-03-24

As wind turbine sizes increase and wind energy expands to more complex and remote sites, remote sensing devices such as lidars are expected to play a key role in wind resource assessment and power performance testing. The switch to remote sensing devices represents a paradigm shift in the way the wind industry typically obtains and interprets measurement data for wind energy. For example, the measurement techniques and sources of uncertainty for a remote sensing device are vastly different from those associated with a cup anemometer on a meteorological tower. Current IEC standards discuss uncertainty due to mounting, calibration, and classificationmore » of the remote sensing device, among other parameters. Values of the uncertainty are typically given as a function of the mean wind speed measured by a reference device. However, real-world experience has shown that lidar performance is highly dependent on atmospheric conditions, such as wind shear, turbulence, and aerosol content. At present, these conditions are not directly incorporated into the estimated uncertainty of a lidar device. In this presentation, we propose the development of a new lidar uncertainty framework that adapts to current flow conditions and more accurately represents the actual uncertainty inherent in lidar measurements under different conditions. In this new framework, sources of uncertainty are identified for estimation of the line-of-sight wind speed and reconstruction of the three-dimensional wind field. These sources are then related to physical processes caused by the atmosphere and lidar operating conditions. The framework is applied to lidar data from an operational wind farm to assess the ability of the framework to predict errors in lidar-measured wind speed.« less

A methodology for TLD postal dosimetry audit of high-energy radiotherapy photon beams in non-reference conditions.

PubMed

Izewska, Joanna; Georg, Dietmar; Bera, Pranabes; Thwaites, David; Arib, Mehenna; Saravi, Margarita; Sergieva, Katia; Li, Kaibao; Yip, Fernando Garcia; Mahant, Ashok Kumar; Bulski, Wojciech

2007-07-01

A strategy for national TLD audit programmes has been developed by the International Atomic Energy Agency (IAEA). It involves progression through three sequential dosimetry audit steps. The first step audits are for the beam output in reference conditions for high-energy photon beams. The second step audits are for the dose in reference and non-reference conditions on the beam axis for photon and electron beams. The third step audits involve measurements of the dose in reference, and non-reference conditions off-axis for open and wedged symmetric and asymmetric fields for photon beams. Through a co-ordinated research project the IAEA developed the methodology to extend the scope of national TLD auditing activities to more complex audit measurements for regular fields. Based on the IAEA standard TLD holder for high-energy photon beams, a TLD holder was developed with horizontal arm to enable measurements 5cm off the central axis. Basic correction factors were determined for the holder in the energy range between Co-60 and 25MV photon beams. New procedures were developed for the TLD irradiation in hospitals. The off-axis measurement methodology for photon beams was tested in a multi-national pilot study. The statistical distribution of dosimetric parameters (off-axis ratios for open and wedge beam profiles, output factors, wedge transmission factors) checked in 146 measurements was 0.999+/-0.012. The methodology of TLD audits in non-reference conditions with a modified IAEA TLD holder has been shown to be feasible.

Bibliography On Multiprocessors And Distributed Processing

NASA Technical Reports Server (NTRS)

Miya, Eugene N.

1988-01-01

Multiprocessor and Distributed Processing Bibliography package consists of large machine-readable bibliographic data base, which in addition to usual keyword searches, used for producing citations, indexes, and cross-references. Data base contains UNIX(R) "refer" -formatted ASCII data and implemented on any computer running under UNIX(R) operating system. Easily convertible to other operating systems. Requires approximately one megabyte of secondary storage. Bibliography compiled in 1985.

14 CFR 135.207 - VFR: Helicopter surface reference requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false VFR: Helicopter surface reference requirements. 135.207 Section 135.207 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... VFR/IFR Operating Limitations and Weather Requirements § 135.207 VFR: Helicopter surface reference...

14 CFR 135.207 - VFR: Helicopter surface reference requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false VFR: Helicopter surface reference requirements. 135.207 Section 135.207 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... VFR/IFR Operating Limitations and Weather Requirements § 135.207 VFR: Helicopter surface reference...

14 CFR 135.207 - VFR: Helicopter surface reference requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false VFR: Helicopter surface reference requirements. 135.207 Section 135.207 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... VFR/IFR Operating Limitations and Weather Requirements § 135.207 VFR: Helicopter surface reference...

14 CFR 135.207 - VFR: Helicopter surface reference requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false VFR: Helicopter surface reference requirements. 135.207 Section 135.207 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... VFR/IFR Operating Limitations and Weather Requirements § 135.207 VFR: Helicopter surface reference...

14 CFR 135.207 - VFR: Helicopter surface reference requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false VFR: Helicopter surface reference requirements. 135.207 Section 135.207 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... VFR/IFR Operating Limitations and Weather Requirements § 135.207 VFR: Helicopter surface reference...