40 CFR Table 6 to Subpart Jjjjjj... - Establishing Operating Limits

Code of Federal Regulations, 2014 CFR

2014-07-01

... Dry sorbent or activated carbon injection rate operating parameters Establish a site-specific minimum sorbent or activated carbon injection rate operating limit according to § 63.11211(b) Data from the sorbent or activated carbon injection rate monitors and the mercury performance stack tests (a) You must...

40 CFR Table 6 to Subpart Jjjjjj... - Establishing Operating Limits

Code of Federal Regulations, 2013 CFR

2013-07-01

... Dry sorbent or activated carbon injection rate operating parameters Establish a site-specific minimum sorbent or activated carbon injection rate operating limit according to § 63.11211(b) Data from the sorbent or activated carbon injection rate monitors and the mercury performance stack tests (a) You must...

40 CFR 75.72 - Determination of NOX mass emissions for common stack and multiple stack configurations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the hourly stack flow rate (in scfh). Only one methodology for determining NOX mass emissions shall be...-diluent continuous emissions monitoring system and a flow monitoring system in the common stack, record... maintain a flow monitoring system and diluent monitor in the duct to the common stack from each unit; or...

Fatigue of extracted lead zirconate titanate multilayer actuators under unipolar high field electric cycling

NASA Astrophysics Data System (ADS)

Wang, Hong; Lee, Sung-Min; Wang, James L.; Lin, Hua-Tay

2014-12-01

Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses subunits extracted from prototypes has been pursued. Extracted 10-layer and 20-layer plate specimens were subjected to an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 108 cycles. The effects of measurement field level and stack size (number of PZT layers) on the fatigue responses of piezoelectric and dielectric coefficients were observed. On-line monitoring permitted examination of the fatigue response of the PZT stacks. The fatigue rate (based on on-line monitoring) and the fatigue index (based on the conductance spectrum from impedance measurement or small signal measurement) were developed to quantify the fatigue status of the PZT stacks. The controlling fatigue mechanism was analyzed against the fatigue observations. The data presented can serve as input to design optimization of PZT stacks and to operation optimization in critical applications, such as piezoelectric fuel injectors in heavy-duty diesel engines.

Fatigue of extracted lead zirconate titanate multilayer actuators under unipolar high field electric cycling

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

Wang, Hong; Lee, Sung Min; Wang, James L.

Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses subunits extracted from prototypes has been pursued. Extracted 10-layer and 20-layer plate specimens were subjected to an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 10^8 cycles. The effects of measurement field level and stack size (number of PZT layers) on the fatigue responses of piezoelectric and dielectric coefficients were observed. On-line monitoring permitted examination of the fatigue response of the PZT stacks. The fatigue rate (based on on-line monitoring) and themore » fatigue index (based on the conductance spectrum from impedance measurement or small signal measurement) were developed to quantify the fatigue status of the PZT stacks. The controlling fatigue mechanism was analyzed against the fatigue observations. The data presented can serve as input to design optimization of PZT stacks and to operation optimization in critical applications such as piezoelectric fuel injectors in heavy-duty diesel engines.« less

Fatigue of extracted lead zirconate titanate multilayer actuators under unipolar high field electric cycling

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

Wang, Hong, E-mail: wangh@ornl.gov; Lee, Sung-Min; Wang, James L.

Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses subunits extracted from prototypes has been pursued. Extracted 10-layer and 20-layer plate specimens were subjected to an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 10{sup 8} cycles. The effects of measurement field level and stack size (number of PZT layers) on the fatigue responses of piezoelectric and dielectric coefficients were observed. On-line monitoring permitted examination of the fatigue response of the PZT stacks. The fatigue rate (based on on-line monitoring) and the fatiguemore » index (based on the conductance spectrum from impedance measurement or small signal measurement) were developed to quantify the fatigue status of the PZT stacks. The controlling fatigue mechanism was analyzed against the fatigue observations. The data presented can serve as input to design optimization of PZT stacks and to operation optimization in critical applications, such as piezoelectric fuel injectors in heavy-duty diesel engines.« less

Fatigue of extracted lead zirconate titanate multilayer actuators under unipolar high field electric cycling

DOE PAGES

Wang, Hong; Lee, Sung Min; Wang, James L.; ...

2014-12-19

Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses subunits extracted from prototypes has been pursued. Extracted 10-layer and 20-layer plate specimens were subjected to an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 10^8 cycles. The effects of measurement field level and stack size (number of PZT layers) on the fatigue responses of piezoelectric and dielectric coefficients were observed. On-line monitoring permitted examination of the fatigue response of the PZT stacks. The fatigue rate (based on on-line monitoring) and themore » fatigue index (based on the conductance spectrum from impedance measurement or small signal measurement) were developed to quantify the fatigue status of the PZT stacks. The controlling fatigue mechanism was analyzed against the fatigue observations. The data presented can serve as input to design optimization of PZT stacks and to operation optimization in critical applications such as piezoelectric fuel injectors in heavy-duty diesel engines.« less

40 CFR 72.90 - Annual compliance certification report.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) using a common stack, were monitored or accounted for through the missing data procedures and reported in the quarterly monitoring reports, including whether conditionally valid data, as defined in § 72.2, were reported in the quarterly report. If conditionally valid data were reported, the owner or operator...

2016 Annual Site Environmental Report

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

Finley, Virginia

This report provides the U.S. Department of Energy (DOE) and the public with information on the level of radioactive and non-radioactive pollutants (if any) that are added to the environment as a result of Princeton Plasma Physics Laboratory’s (PPPL) operations. The results of the 2016 environmental surveillance and monitoring program for PPPL’s are presented and discussed. The report also summarizes environmental initiatives, assessments, and community involvement programs that were undertaken in 2016. PPPL has engaged in fusion energy research since 1951. The vision of the Laboratory is to create innovations to make fusion power a practical reality – a clean,more » alternative energy source. 2016 marked the eighteenth year of National Spherical Torus Experiment and the first year of NSTX-U (Upgrade) operations. The NSTX-U Project is a collaboration among national laboratories, universities, and national and international research institutions and is a major element in the US Fusion Energy Sciences Program. Its design tests the physics principles of spherical torus (ST) plasmas, playing an important role in the development of smaller, more economical fusion reactors. NSTX-U began operations after its first upgrade that installed the new center stack magnets and second neutral beam, which would allow for hotter plasmas and greater field strength to maintain the fusion reaction longer. Due to operational issues with a poloidal coil, NSTX-U operated briefly in 2016. In 2016, PPPL’s radiological environmental monitoring program measured tritium in the air at the NSTX-U Stack and at on -site sampling stations. Using highly sensitive monitors, PPPL is capable of detecting small changes in the ambient levels of tritium. The operation of an in- stack monitor located on D-site is used to demonstrate compliance with the National Emission Standard for Hazardous Air Pollutants (NESHAPs) regulations. Also included in PPPL’s radiological environmental monitoring program, are water monitoring – ground and surface, and waste waters. PPPL’s radiological monitoring program characterized the background levels of tritium in the environment; the data are presented in this report. Ground water monitoring continued under the New Jersey Department of Environmental Protection’s Site Remediation Program. PPPL monitored for non-radiological contaminants, mainly volatile organic compounds (components of chlorinated degreasing solvents). In 2016, PPPL was in compliance with its permit limits for surface and sanitary discharges, excepting two elevated chlorine-produced oxidant concentration. PPPL was honored with awards for its waste reduction and recycling program, and its “EPEAT” electronics purchasing for the third consecutive year.« less

Utilizing Non-Contact Stress Measurement System (NSMS) as a Health Monitor

NASA Technical Reports Server (NTRS)

Hayes, Terry; Hayes, Bryan; Bynum, Ken

2011-01-01

Continuously monitor all 156 blades throughout the entire operating envelope without adversely affecting tunnel conditions or compromise compressor shell integrity, Calculate dynamic response and identify the frequency/mode to determine individual blade deflection amplitudes, natural frequencies, phase, and damping (Q), Log static deflection to build a database of deflection values at certain compressor conditions to use as basis for real-time online Blade Stack monitor, Monitor for stall, surge, flutter, and blade damage, Operate with limited user input, low maintenance cost, safe illumination of probes, easy probe replacement, and require little or no access to compressor.

Fuel Cell/Electrochemical Cell Voltage Monitor

NASA Technical Reports Server (NTRS)

Vasquez, Arturo

2012-01-01

A concept has been developed for a new fuel cell individual-cell-voltage monitor that can be directly connected to a multi-cell fuel cell stack for direct substack power provisioning. It can also provide voltage isolation for applications in high-voltage fuel cell stacks. The technology consists of basic modules, each with an 8- to 16-cell input electrical measurement connection port. For each basic module, a power input connection would be provided for direct connection to a sub-stack of fuel cells in series within the larger stack. This power connection would allow for module power to be available in the range of 9-15 volts DC. The relatively low voltage differences that the module would encounter from the input electrical measurement connection port, coupled with the fact that the module's operating power is supplied by the same substack voltage input (and so will be at similar voltage), provides for elimination of high-commonmode voltage issues within each module. Within each module, there would be options for analog-to-digital conversion and data transfer schemes. Each module would also include a data-output/communication port. Each of these ports would be required to be either non-electrical (e.g., optically isolated) or electrically isolated. This is necessary to account for the fact that the plurality of modules attached to the stack will normally be at a range of voltages approaching the full range of the fuel cell stack operating voltages. A communications/ data bus could interface with the several basic modules. Options have been identified for command inputs from the spacecraft vehicle controller, and for output-status/data feeds to the vehicle.

40 CFR 62.14690 - What monitoring equipment must I install and what parameters must I monitor?

Code of Federal Regulations, 2010 CFR

2010-07-01

... subpart, you must install, calibrate, maintain, and continuously operate a bag leak detection system as... detection system for each exhaust stack of the fabric filter. (2) Each bag leak detection system must be... specifications and recommendations. (3) The bag leak detection system must be certified by the manufacturer to be...

40 CFR 75.16 - Special provisions for monitoring emissions from common, bypass, and multiple stacks for SO2...

Code of Federal Regulations, 2010 CFR

2010-07-01

... maintain an SO2 continuous emission monitoring system and flow monitoring system in the duct to the common... emission monitoring system and flow monitoring system in the common stack and combine emissions for the... continuous emission monitoring system and flow monitoring system in the duct to the common stack from each...

Interactive Inventory Monitoring

NASA Technical Reports Server (NTRS)

Garud, Sumedha

2013-01-01

Method and system for monitoring present location and/or present status of a target inventory item, where the inventory items are located on one or more inventory shelves or other inventory receptacles that communicate with an inventory base station through use of responders such as RFIDs. A user operates a hand held interrogation and display (lAD) module that communicates with, or is part of the base station to provide an initial inquiry. lnformation on location(s) of the larget invenlory item is also indicated visibly and/or audibly on the receptacle(s) for the user. Status information includes an assessment of operation readiness and a time, if known, that the specified inventory item or class was last removed or examined or modified. Presentation of a user access level may be required for access to the target inventgory item. Another embodiment provides inventory informatin for a stack as a sight-impaired or hearing-impaired person adjacent to that stack.

Interactive inventory monitoring

NASA Technical Reports Server (NTRS)

Spremo, Stevan M. (Inventor); Udoh, Usen E. (Inventor)

2009-01-01

Method and system for monitoring present location and/or present status of a target inventory item, where the inventory items are located on one or more inventory shelves or other inventory receptacles that communicate with an inventory base station through use of responders such as RFIDs. A user operates a hand held interrogation and display (IAD) module that communicates with, or is part of, the base station, to provide an initial inquiry. Information on location(s) of the target inventory item is also indicated visibly and/or audibly on the receptacle(s) for the user. Status information includes an assessment of operation readiness and a time, if known, that the specified inventory item or class was last removed or examined or modified. Presentation of a user access level may be required for access to the target inventory item. Another embodiment provides inventory information for a stack as a sight-impaired or hearing-impaired person passes adjacent to that stack.

Design and Implementation of an Operations Module for the ARGOS paperless Ship System

DTIC Science & Technology

1989-06-01

A. OPERATIONS STACK SCRIPTS SCRIPTS FOR STACK: operations * BACKGROUND #1: Operations * on openStack hide message box show menuBar pass openStack end... openStack ** CARD #1, BUTTON #1: Up ***** on mouseUp visual effect zoom out go to card id 10931 of stack argos end mouseUp ** CARD #1, BUTTON #2...STACK SCRIPTS SCRIPTS FOR STACK: Reports ** BACKGROUND #1: Operations * on openStack hie message box show menuBar pass openStack end openStack ** CARD #1

Non-Operational Property Evaluation for the Hanford Site River Corridor - 12409

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

Lowe, John; Aly, Alaa

2012-07-01

The Hanford Site River Corridor consists of the former reactor areas of the 100 Areas and the former industrial (fuel processing) area in the 300 Area. Most of the waste sites are located close to the decommissioned reactors or former industrial facilities along the Columbia River. Most of the surface area of the River Corridor consists of land with little or no subsurface infrastructure or indication of past or present releases of hazardous constituents, and is referred to as non-operational property or non-operational area. Multiple lines of evidence have been developed to assess identified fate and transport mechanisms and tomore » evaluate the potential magnitude and significance of waste site-related contaminants in the non-operational area. Predictive modeling was used for determining the likelihood of locating waste sites and evaluating the distribution of radionuclides in soil based on available soil concentration data and aerial radiological surveys. The results of this evaluation indicated: 1) With the exception of stack emissions, transport pathways associated with waste site contaminants are unlikely to result in dispersion of contaminants in soil away from operational areas, 2) Stack emissions that may have been associated with Hanford Site operations generally emitted short-lived and/or gaseous radionuclides, and (3) the likelihood of detecting elevated radionuclide concentrations or other waste sites in non-operational area soils is very small. The overall conclusions from the NPE evaluation of the River Corridor are: - With the exception of stack emissions to the air, transport pathways associated with waste site contaminants are unlikely to result in dispersion of contaminants in soil away from operational areas. While pathways such as windblown dust, overland transport and biointrusion have the potential for dispersing waste site contaminants, the resulting transport is unlikely to result in substantial contamination in non-operational areas. - Stack emissions that may have been associated with Hanford Site operations generally emitted short-lived and/or gaseous radionuclides; these radionuclides either would have decayed and would be undetectable in soil, or likely would not have deposited onto Hanford Site soils. A small fraction of the total historical emissions consisted of long-lived particulate radionuclides, which could have deposited onto the soil. Soil monitoring studies conducted as part of surveillance and monitoring programs do not indicate a build-up of radionuclide concentrations in soil, which might indicate potential deposition impacts from stack emissions. Aerial radiological surveys of the Hanford Site, while effective in detecting gamma-emitting nuclides, also do not indicate deposition patterns in soil from stack emissions. - The surveillance and monitoring programs also have verified that the limited occurrence of biointrusion observed in the River Corridor has not resulted in a spread of contamination into the non-operational areas. - Monitoring of radionuclides in ambient air conducted as part of the surveillance and monitoring programs generally show a low and declining trend of detected concentrations in air. Monitoring of radionuclides in soil and vegetation correspondingly show declining trends in concentrations, particularly for nuclides with short half lives (Cs-137, Co-60 and Sr-90). - Statistical analysis of the geographical distribution of waste sites based on man -made features and topography describes the likely locations of waste sites in the River Corridor. The results from this analysis reinforce the findings from the Orphan Site Evaluation program, which has systematically identified any remaining waste sites within the River Corridor. - Statistical analysis of the distribution of radionuclide concentrations observable from aerial surveys has confirmed that the likelihood of detecting elevated radionuclide concentrations in non-operational area soils is very small; the occurrences and locations where potentially elevated concentrations may be found are discussed below. In addition, statistical analysis showed that there is a relatively high probability (>50%) that concentrations of Cs-137 higher than background (3.9 Bq/kg or 1.05 pCi/g) are located outside of the operational portion of the 100-BC, 100-K, and 100-N Areas. This observation is based on modeled concentrations in soil derived from aerial radiography data. However, the extent is limited to a few meters from the respective facilities fence lines or known operational activities. Evaluation of the extent of contamination is being conducted as part of the RI process for each decision area. No unanticipated waste sites were identified either from the OSE program or statistical analysis of waste site proximity to known features. Based on the evaluation of these multiple lines of evidence, the likelihood of identifying waste sites or contaminant dispersal from Hanford site operations into non-operational areas can be considered very small. (authors)« less

Regenerative Fuel Cell Test Rig at Glenn Research Center

NASA Technical Reports Server (NTRS)

Chang, Bei-Jiann; Johnson, Donald W.; Garcia, Christopher P.; Jakupca, Ian J.; Scullin, Vincent J.; Bents, David J.

2003-01-01

The regenerative fuel cell development effort at Glenn Research Center (GRC) involves the integration of a dedicated fuel cell and electrolyzer into an energy storage system test rig. The test rig consists of a fuel cell stack, an electrolysis stack, cooling pumps, a water transfer pump, gas recirculation pumps, phase separators, storage tanks for oxygen (O2) and hydrogen (H2), heat exchangers, isolation valves, pressure regulators, interconnecting tubing, nitrogen purge provisions, and instrumentation for control and monitoring purposes. The regenerative fuel cell (RFC) thus formed is a completely closed system which is capable of autonomous cyclic operation. The test rig provides direct current (DC) load and DC power supply to simulate power consumption and solar power input. In addition, chillers are used as the heat sink to dissipate the waste heat from the electrochemical stack operation. Various vents and nitrogen (N2) sources are included in case inert purging is necessary to safe the RFC test rig.

81. THREE ADDITIONAL BLACK AND WHITE VIDEO MONITORS LOCATED IMMEDIATELY ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

81. THREE ADDITIONAL BLACK AND WHITE VIDEO MONITORS LOCATED IMMEDIATELY WEST OF THOSE IN CA-133-1-A-80. COMPLEX SAFETY WARNING LIGHTS FOR SLC-3E (PAD 2) AND BLDG. 763 (LOB) LOCATED ABOVE MONITOR 3; GREEN LIGHTS ON BOTTOM OF EACH STACK ILLUMINATED. LEFT TO RIGHT BELOW MONITORS: ACCIDENT REPORTING EMERGENCY NOTIFICATION SYSTEM TELEPHONE, ATLAS H FUEL COUNTER, AND DIGITAL COUNTDOWN CLOCK. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Laser Doppler systems in pollution monitoring

NASA Technical Reports Server (NTRS)

Miller, C. R.; Sonnenschein, C. M.; Herget, W. F.; Huffaker, R. M.

1976-01-01

The paper reports on a program undertaken to determine the feasibility of using a laser Doppler velocimeter (LDV) to measure smoke-stack gas exit velocity, particulate concentration, and mass flow. Measurements made with a CO2 laser Doppler radar system at a coal-burning power plant are compared with in-stack measurements made by a pitot tube. The operational principles of a LDV are briefly described along with the system employed in the present study. Data discussed include typical Doppler spectra from smoke-stack effluents at various laser elevation angles, the measured velocity profile across the stack exit, and the LDV-measured exit velocity as a function of the exit velocity measured by the in-stack instrument. The in-stack velocity is found to be about 14% higher than the LDV velocity, but this discrepancy is regarded as a systematic error. In general, linear relationships are observed between the laser data, the exit velocity, and the particulate concentration. It is concluded that an LDV has the capability of determining both the mass concentration and the mass flow from a power-plant smoke stack.

40 CFR Table 3 to Subpart Jjjjjj... - Operating Limits for Boilers With Emission Limits

Code of Federal Regulations, 2011 CFR

2011-07-01

... system alarm does not sound more than 5 percent of the operating time during each 6-month period. 2... the pressure drop at or above the lowest 1-hour average pressure drop across the wet scrubber and the... recent performance stack test. 8. Continuous Oxygen Monitor Maintain the oxygen level at or above the...

40 CFR 60.2944 - What operating parameter monitoring equipment must I install, and what operating parameters must...

Code of Federal Regulations, 2010 CFR

2010-07-01

... using a wet scrubber to comply with the emission limitations under § 60.2915, you must install... must include the date, time, and duration of the use of the bypass stack. (c) If you are using a method or air pollution control device other than a wet scrubber to comply with the emission limitations...

Primary particulate matter from ocean-going engines in the Southern California Air Basin.

PubMed

Agrawal, Harshit; Eden, Rudy; Zhang, Xinqiu; Fine, Philip M; Katzenstein, Aaron; Miller, J Wayne; Ospital, Jean; Teffera, Solomon; Cocker, David R

2009-07-15

The impact of primary fine particulate matter (PM2.5) from ship emissions within the Southern California Air Basin is quantified by comparing in-stack vanadium (V) and nickel (Ni) measurements from in-use ocean-going vessels (OGVs) with ambient measurements made at 10 monitoring stations throughout Southern California. V and Ni are demonstrated as robust markers for the combustion of heavy fuel oil in OGVs, and ambient measurements of fine particulate V and Ni within Southern California are shown to decrease inversely with increased distance from the ports of Los Angeles and Long Beach (ports). High levels of V and Ni were observed from in-stack emission measurements conducted on the propulsion engines of two different in-use OGVs. The in-stack V and Ni emission rates (g/h) normalized by the V and Ni contents in the fuel tested correlates with the stack total PM emission rates (g/h). The normalized emission rates are used to estimate the primary PM2.5 contributions from OGVs at 10 monitoring locations within Southern California. Primary PM2.5 contributions from OGVs were found to range from 8.8% of the total PM2.5 at the monitoring location closest to the port (West Long Beach) to 1.4% of the total PM2.5 at the monitoring location 80 km inland (Rubidoux). The calculated OGV contributions to ambient PM2.5 measurements at the 10 monitoring sites agree well with estimates developed using an emission inventory based regional model. Results of this analysis will be useful in determining the impacts of primary particulate emissions from OGVs upon worldwide communities downwind of port operations.

WLCG Monitoring Consolidation and further evolution

NASA Astrophysics Data System (ADS)

Saiz, P.; Aimar, A.; Andreeva, J.; Babik, M.; Cons, L.; Dzhunov, I.; Forti, A.; di Girolamo, A.; Karavakis, E.; Litmaath, M.; Magini, N.; Magnoni, L.; de los Rios, H. Martin; Roiser, S.; Sciaba, A.; Schulz, M.; Tarragon, J.; Tuckett, D.

2015-12-01

The WLCG monitoring system solves a challenging task of keeping track of the LHC computing activities on the WLCG infrastructure, ensuring health and performance of the distributed services at more than 170 sites. The challenge consists of decreasing the effort needed to operate the monitoring service and to satisfy the constantly growing requirements for its scalability and performance. This contribution describes the recent consolidation work aimed to reduce the complexity of the system, and to ensure more effective operations, support and service management. This was done by unifying where possible the implementation of the monitoring components. The contribution also covers further steps like the evaluation of the new technologies for data storage, processing and visualization and migration to a new technology stack.

Advanced measurement techniques to characterize thermo-mechanical aspects of solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Malzbender, J.; Steinbrech, R. W.

Advanced characterization methods have been used to analyze the thermo-mechanical behaviour of solid oxide fuel cells in a model stack. The primarily experimental work included contacting studies, sealing of a model stack, thermal and re-oxidation cycling. Also an attempt was made to correlate cell fracture in the stack with pore sizes determined from computer tomography. The contacting studies were carried out using pressure sensitive foils. The load to achieve full contact on anode and cathode side of the cell was assessed and applied in the subsequent model stack test. The stack experiment permitted a detailed analysis of stack compaction during sealing. During steady state operation thermal and re-oxidation cycling the changes in open cell voltage and acoustic emissions were monitored. Significant softening of the sealant material was observed at low temperatures. Heating in the thermal cycling loop of the stack appeared to be less critical than the cooling. Re-oxidation cycling led to significant damage if a critical re-oxidation time was exceeded. Microstructural studies permitted further insight into the re-oxidation mechanism. Finally, the maximum defect size in the cell was determined by computer tomography. A limit of maximum anode stress was estimated and the result correlated this with the failure strength observed during the model stack testing.

40 CFR 60.143 - Monitoring of operations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... steel production cycle, and the time and duration of any diversion of exhaust gases from the main stack... sensor or pressure tap must be located close to the water discharge point. The Administrator must be consulted for approval in advance of selecting alternative locations for the pressure sensor or tap. (3) All...

40 CFR 60.143 - Monitoring of operations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... steel production cycle, and the time and duration of any diversion of exhaust gases from the main stack... sensor or pressure tap must be located close to the water discharge point. The Administrator must be consulted for approval in advance of selecting alternative locations for the pressure sensor or tap. (3) All...

Method for operating a combustor in a fuel cell system

DOEpatents

Chalfant, Robert W.; Clingerman, Bruce J.

2002-01-01

A method of operating a combustor to heat a fuel processor in a fuel cell system, in which the fuel processor generates a hydrogen-rich stream a portion of which is consumed in a fuel cell stack and a portion of which is discharged from the fuel cell stack and supplied to the combustor, and wherein first and second streams are supplied to the combustor, the first stream being a hydrocarbon fuel stream and the second stream consisting of said hydrogen-rich stream, the method comprising the steps of monitoring the temperature of the fuel processor; regulating the quantity of the first stream to the combustor according to the temperature of the fuel processor; and comparing said quantity of said first stream to a predetermined value or range of predetermined values.

Source Term Estimates of Radioxenon Released from the BaTek Medical Isotope Production Facility Using External Measured Air Concentrations

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

Eslinger, Paul W.; Cameron, Ian M.; Dumais, Johannes R.

2015-10-01

Abstract Batan Teknologi (BaTek) operates an isotope production facility in Serpong, Indonesia that supplies 99mTc for use in medical procedures. Atmospheric releases of Xe-133 in the production process at BaTek are known to influence the measurements taken at the closest stations of the International Monitoring System (IMS). The purpose of the IMS is to detect evidence of nuclear explosions, including atmospheric releases of radionuclides. The xenon isotopes released from BaTek are the same as those produced in a nuclear explosion, but the isotopic ratios are different. Knowledge of the magnitude of releases from the isotope production facility helps inform analystsmore » trying to decide whether a specific measurement result came from a nuclear explosion. A stack monitor deployed at BaTek in 2013 measured releases to the atmosphere for several isotopes. The facility operates on a weekly cycle, and the stack data for June 15-21, 2013 show a release of 1.84E13 Bq of Xe-133. Concentrations of Xe-133 in the air are available at the same time from a xenon sampler located 14 km from BaTek. An optimization process using atmospheric transport modeling and the sampler air concentrations produced a release estimate of 1.88E13 Bq. The same optimization process yielded a release estimate of 1.70E13 Bq for a different week in 2012. The stack release value and the two optimized estimates are all within 10 percent of each other. Weekly release estimates of 1.8E13 Bq and a 40 percent facility operation rate yields a rough annual release estimate of 3.7E13 Bq of Xe-133. This value is consistent with previously published estimates of annual releases for this facility, which are based on measurements at three IMS stations. These multiple lines of evidence cross-validate the stack release estimates and the release estimates from atmospheric samplers.« less

40 CFR 63.10010 - What are my monitoring, installation, operation, and maintenance requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

... emissions are controlled with a common control device or series of control devices, are discharged to the... devices or multiple series of control devices are discharged to the atmosphere through more than one stack... control activities (including, as applicable, calibration checks and required zero and span adjustments...

40 CFR Appendix B to Part 75 - Quality Assurance and Quality Control Procedures

Code of Federal Regulations, 2011 CFR

2011-07-01

... suitable for inspection. A maintenance log may be used for this purpose. The following records should be... the previous 26 unit (or stack) operating hours; and (b) the 26 clock hour data validation window for... official test log for each monitoring system. (i) The results of any certification, recertification...

NASA Glenn Research Center's Fuel Cell Stack, Ancillary and System Test and Development Laboratory

NASA Technical Reports Server (NTRS)

Loyselle, Patricia L.; Prokopius, Kevin P.; Becks, Larry A.; Burger, Thomas H.; Dick, Joseph F.; Rodriguez, George; Bremenour, Frank; Long, Zedock

2011-01-01

At the NASA Glenn Research Center, a fully operational fuel cell test and evaluation laboratory is available which is capable of evaluating fuel cell components and systems for future NASA missions. Components and subsystems of various types can be operated and monitored under a variety of conditions utilizing different reactants. This fuel cell facility can test the effectiveness of various component and system designs to meet NASA's needs.

Method for monitoring stack gases for uranium activity

DOEpatents

Beverly, C.R.; Ernstberger, E.G.

1985-07-03

A method for monitoring the stack gases of a purge cascade of gaseous diffusion plant for uranium activity. A sample stream is taken from the stack gases and contacted with a volume of moisture-laden air for converting trace levels of uranium hexafluoride, if any, in the stack gases into particulate uranyl fluoride. A continuous strip of filter paper from a supply roll is passed through this sampling stream to intercept and gather any uranyl fluoride in the sampling stream. This filter paper is then passed by an alpha scintillation counting device where any radioactivity on the filter paper is sensed so as to provide a continuous monitoring of the gas stream for activity indicative of the uranium content in the stack gases. 1 fig.

Method for monitoring stack gases for uranium activity

DOEpatents

Beverly, Claude R.; Ernstberger, Harold G.

1988-01-01

A method for monitoring the stack gases of a purge cascade of a gaseous diffusion plant for uranium activity. A sample stream is taken from the stack gases and contacted with a volume of moisture-laden air for converting trace levels of uranium hexafluoride, if any, in the stack gases into particulate uranyl fluoride. A continuous strip of filter paper from a supply roll is passed through this sampling stream to intercept and gather any uranyl fluoride in the sampling stream. This filter paper is then passed by an alpha scintillation counting device where any radioactivity on the filter paper is sensed so as to provide a continuous monitoring of the gas stream for activity indicative of the uranium content in the stack gases.

Cascading and Parallelising Curvilinear Inertial Focusing Systems for High Volume, Wide Size Distribution, Separation and Concentration of Particles

PubMed Central

Miller, B.; Jimenez, M.; Bridle, H.

2016-01-01

Inertial focusing is a microfluidic based separation and concentration technology that has expanded rapidly in the last few years. Throughput is high compared to other microfluidic approaches although sample volumes have typically remained in the millilitre range. Here we present a strategy for achieving rapid high volume processing with stacked and cascaded inertial focusing systems, allowing for separation and concentration of particles with a large size range, demonstrated here from 30 μm–300 μm. The system is based on curved channels, in a novel toroidal configuration and a stack of 20 devices has been shown to operate at 1 L/min. Recirculation allows for efficient removal of large particles whereas a cascading strategy enables sequential removal of particles down to a final stage where the target particle size can be concentrated. The demonstration of curved stacked channels operating in a cascaded manner allows for high throughput applications, potentially replacing filtration in applications such as environmental monitoring, industrial cleaning processes, biomedical and bioprocessing and many more. PMID:27808244

40 CFR 63.10011 - How do I demonstrate initial compliance with the emissions limits and work practice standards?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Hazardous Air Pollutants: Coal- and Oil-Fired Electric Utility Steam Generating Units Testing and Initial... liquid oil-fired unit, and you use quarterly stack testing for HCl and HF plus site-specific parameter monitoring to demonstrate continuous performance, you must also establish a site-specific operating limit, in...

40 CFR 63.10011 - How do I demonstrate initial compliance with the emissions limits and work practice standards?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Hazardous Air Pollutants: Coal- and Oil-Fired Electric Utility Steam Generating Units Testing and Initial... liquid oil-fired unit, and you use quarterly stack testing for HCl and HF plus site-specific parameter monitoring to demonstrate continuous performance, you must also establish a site-specific operating limit, in...

40 CFR 63.7740 - What are my monitoring requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

... positive pressure baghouse equipped with a stack that is applied to meet any PM or total metal HAP..., regardless of type, that is applied to meet any PM or total metal HAP emissions limitation in this subpart... detectors, or equivalent means. (d) For each wet scrubber subject to the operating limits in § 63.7690(b)(2...

40 CFR 63.7740 - What are my monitoring requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

... pressure baghouse equipped with a stack that is applied to meet any PM or total metal HAP emissions..., that is applied to meet any PM or total metal HAP emissions limitation in this subpart, you must... detectors, or equivalent means. (d) For each wet scrubber subject to the operating limits in § 63.7690(b)(2...

40 CFR 63.7740 - What are my monitoring requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... positive pressure baghouse equipped with a stack that is applied to meet any PM or total metal HAP..., regardless of type, that is applied to meet any PM or total metal HAP emissions limitation in this subpart... detectors, or equivalent means. (d) For each wet scrubber subject to the operating limits in § 63.7690(b)(2...

40 CFR 75.82 - Monitoring of Hg mass emissions and heat input at common and multiple stacks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... heat input at common and multiple stacks. 75.82 Section 75.82 Protection of Environment ENVIRONMENTAL... Provisions § 75.82 Monitoring of Hg mass emissions and heat input at common and multiple stacks. (a) Unit... systems and perform the Hg emission testing described under § 75.81(b). If reporting of the unit heat...

Acoustic thermometry for detecting quenches in superconducting coils and conductor stacks

NASA Astrophysics Data System (ADS)

Marchevsky, M.; Gourlay, S. A.

2017-01-01

Quench detection capability is essential for reliable operation and protection of superconducting magnets, coils, cables, and machinery. We propose a quench detection technique based on sensing local temperature variations in the bulk of a superconducting winding by monitoring its transient acoustic response. Our approach is primarily aimed at coils and devices built with high-temperature superconductor materials where quench detection using standard voltage-based techniques may be inefficient due to the slow velocity of quench propagation. The acoustic sensing technique is non-invasive, fast, and capable of detecting temperature variations of less than 1 K in the interior of the superconductor cable stack in a 77 K cryogenic environment. We show results of finite element modeling and experiments conducted on a model superconductor stack demonstrating viability of the technique for practical quench detection, discuss sensitivity limits of the technique, and its various applications.

Stack Characterization in CryoSat Level1b SAR/SARin Baseline C

NASA Astrophysics Data System (ADS)

Scagliola, Michele; Fornari, Marco; Di Giacinto, Andrea; Bouffard, Jerome; Féménias, Pierre; Parrinello, Tommaso

2015-04-01

CryoSat was launched on the 8th April 2010 and is the first European ice mission dedicated to the monitoring of precise changes in the thickness of polar ice sheets and floating sea ice. CryoSat is the first altimetry mission operating in SAR mode and it carries an innovative radar altimeter called the Synthetic Aperture Interferometric Altimeter (SIRAL), that transmits pulses at a high pulse repetition frequency thus making the received echoes phase coherent and suitable for azimuth processing. The current CryoSat IPF (Instrument Processing Facility), Baseline B, was released in operation in February 2012. After more than 2 years of development, the release in operations of the Baseline C is expected in the first half of 2015. It is worth recalling here that the CryoSat SAR/SARin IPF1 generates 20Hz waveforms in correspondence of an approximately equally spaced set of ground locations on the Earth surface, i.e. surface samples, and that a surface sample gathers a collection of single-look echoes coming from the processed bursts during the time of visibility. Thus, for a given surface sample, the stack can be defined as the collection of all the single-look echoes pointing to the current surface sample, after applying all the necessary range corrections. The L1B product contains the power average of all the single-look echoes in the stack: the multi-looked L1B waveform. This reduces the data volume, while removing some information contained in the single looks, useful for characterizing the surface and modelling the L1B waveform. To recover such information, a set of parameters has been added to the L1B product: the stack characterization or beam behaviour parameters. The stack characterization, already included in previous Baselines, has been reviewed and expanded in Baseline C. This poster describes all the stack characterization parameters, detailing what they represent and how they have been computed. In details, such parameters can be summarized in: - Stack statistical parameters, such as skewness and kurtosis - Look angle (i.e. the angle at which the surfaces sample is seen with respect to the nadir direction of the satellite) and Doppler angle (i.e. the angle at which the surfaces sample is seen with respect to the normal to the velocity vector) for the first and the last single-look echoes in the stack. - Number of single-looks averaged in the stack (in Baseline C a stack-weighting has been applied that reduces the number of looks). With the correct use of these parameters, users will be able to retrieve some of the 'lost' information contained within the stack and fully exploit the L1B product.

Static regenerative fuel cell system for use in space

NASA Technical Reports Server (NTRS)

Levy, Alexander H. (Inventor); VanDine, Leslie L. (Inventor); Trocciola, John C. (Inventor)

1989-01-01

The cell stack can be operated as a fuel cell stack or as an electrolysis cell stack. The stack consists of a series of alternate fuel cell subassemblies with intervening electrolysis cell subassemblies, and interspersed cooling plates. The water produced and consumed in the two modes of operation migrates between adjacent cell subassemblies. The component plates are annular with a central hydrogen plenum and integral internal oxygen manifolds. No fluid pumps are needed to operate the stack in either mode.

Develop and test fuel cell powered on-site integrated total energy systems. Phase 3: Full-scale power plant development

NASA Technical Reports Server (NTRS)

Kaufman, A.; Pudick, S.; Wang, C. L.; Werth, J.; Whelan, J. A.

1984-01-01

Two 25-cell, 13 inch x 23 inch (4kW) stacks were started up to evaluate the reliability of component and stack technology developed through the end of 1983. Both stacks started up well and are running satisfactorily on hydrogen-air after 1900 hours and 800 hours, respectively. A synthetic-reformat mixing station is nearing completion, and both stacks will be operated on reformate fuel. A stack-protection control system was placed in operation for Stack No. 2, and a similar set-up is in preparation for Stack No. 1. This system serves to change operating conditions or shut the stack down to avoid deleterious effects from nonstack-related upsets. The capability will greatly improve changes of obtaining meaningful long-term test data.

Source term estimates of radioxenon released from the BaTek medical isotope production facility using external measured air concentrations.

PubMed

Eslinger, Paul W; Cameron, Ian M; Dumais, Johannes Robert; Imardjoko, Yudi; Marsoem, Pujadi; McIntyre, Justin I; Miley, Harry S; Stoehlker, Ulrich; Widodo, Susilo; Woods, Vincent T

2015-10-01

BATAN Teknologi (BaTek) operates an isotope production facility in Serpong, Indonesia that supplies (99m)Tc for use in medical procedures. Atmospheric releases of (133)Xe in the production process at BaTek are known to influence the measurements taken at the closest stations of the radionuclide network of the International Monitoring System (IMS). The purpose of the IMS is to detect evidence of nuclear explosions, including atmospheric releases of radionuclides. The major xenon isotopes released from BaTek are also produced in a nuclear explosion, but the isotopic ratios are different. Knowledge of the magnitude of releases from the isotope production facility helps inform analysts trying to decide if a specific measurement result could have originated from a nuclear explosion. A stack monitor deployed at BaTek in 2013 measured releases to the atmosphere for several isotopes. The facility operates on a weekly cycle, and the stack data for June 15-21, 2013 show a release of 1.84 × 10(13) Bq of (133)Xe. Concentrations of (133)Xe in the air are available at the same time from a xenon sampler located 14 km from BaTek. An optimization process using atmospheric transport modeling and the sampler air concentrations produced a release estimate of 1.88 × 10(13) Bq. The same optimization process yielded a release estimate of 1.70 × 10(13) Bq for a different week in 2012. The stack release value and the two optimized estimates are all within 10% of each other. Unpublished production data and the release estimate from June 2013 yield a rough annual release estimate of 8 × 10(14) Bq of (133)Xe in 2014. These multiple lines of evidence cross-validate the stack release estimates and the release estimates based on atmospheric samplers. Copyright © 2015 Elsevier Ltd. All rights reserved.

40 CFR 75.15 - Special provisions for measuring Hg mass emissions using the excepted sorbent trap monitoring...

Code of Federal Regulations, 2010 CFR

2010-07-01

... the excepted sorbent trap monitoring methodology. For an affected coal-fired unit under a State or...; (c) A certified flow monitoring system is required; (d) Correction for stack gas moisture content is... proportional to the stack gas volumetric flow rate. (f) At the beginning and end of each sample collection...

Short protection device for stack of electrolytic cells

DOEpatents

Katz, M.; Schroll, C.R.

1984-11-29

The present invention relates to a device for preventing the electrical shorting of a stack of electrolytic cells during an extended period of operation. The device has application to fuel cell and other electrolytic cell stacks operating in low or high temperature corrosive environments. It is of particular importance for use in a stack of fuel cells operating with molten metal carbonate electrolyte for the production of electric power. Also, the device may have application in similar technology involving stacks of electrolytic cells for electrolysis to decompose chemical compounds.

Real-time Stack Monitoring at the BaTek Medical Isotope Production Facility

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

McIntyre, Justin I.; Agusbudiman, A.; Cameron, Ian M.

2016-04-01

Radioxenon emissions from radiopharmaceutical production are a major source of background concentrations affecting the radioxenon detection systems of the International Monitoring System (IMS). Collection of real-time emissions data from production facilities makes it possible to screen out some medical isotope signatures from the IMS radioxenon data sets. This paper describes an effort to obtain and analyze real-time stack emissions data with the design, construction and installation of a small stack monitoring system developed by a joint CTBTO-IDC, BATAN, and PNNL team at the BaTek medical isotope production facility near Jakarta, Indonesia.

SRS environmental air surveillance program 1954-2015: General trends

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

Abbott, K.; Jannik, T.

The radiological monitoring program at SRS was established under the DuPont Company in June 1951 and was used as a measurement of the effectiveness of plant controls and as an authoritative record of environmental conditions surrounding the plant. It also served as a method of demonstrating compliance with applicable federal regulations and guidance. This document serves as a general summary of changes made specifically to the environmental air monitoring program since its inception, and a discussion of the general trends seen in the air monitoring program at SRS from 1954 to 2015. Initially, the environmental air surveillance program focused notmore » only on releases from SRS but also on fallout from various weapons testing performed through the end of 1978. Flypaper was used to measure the amount of fallout in the atmosphere during this period, and was present at each of the 10 monitoring stations. By 1959, all site stacks were included in the air monitoring program to determine their contribution to the airborne radioactivity onsite, and the number of air surveillance samplers rose to 18. This trend of an increased number of sampling locations continued to a peak of 35 sampling locations before shifting to a downward trend in the mid-1990s. In 1962, 4 outer-range samplers were placed in Savannah and Macon, GA, and in Greenville and Columbia, SC. Until 1976, air samplers were simply placed around the perimeter of the various operation locations (after 1959, this included stacks to determine their contribution to the airborne radioactivity), with the intent of creating as representative a distribution as possible of the air surrounding operations.« less

TI-59 PROGRAMMABLE CALCULATOR PROGRAMS FOR IN-STACK OPACITY, VENTURI SCRUBBERS, AND ELECTROSTATIC PRECIPITATORS

EPA Science Inventory

The report explains the basic concepts of in-stack opacity as measured by in-stack opacity monitors. Also included are calculator programs that model the performance of venturi scrubbers and electrostatic precipitators. The effect of particulate control devices on in-stack opacit...

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

Virginia L. Finley

The purpose of this report is to provide the U.S. Department of Energy (DOE) and the public with information on the level of radioactive and nonradioactive pollutants (if any) that are added to the environment as a result of the Princeton Plasma Physics Laboratory's (PPPL) operations. The results of the 2001 environmental surveillance and monitoring program for PPPL are presented and discussed. The report also summarizes environmental initiatives, assessments, and programs that were undertaken in 2001. PPPL has engaged in fusion energy research since 1951. The vision of the Laboratory is to create innovations to make fusion power a practicalmore » reality--a clean, alternative energy source. The Year 2001 marked the third year of National Spherical Torus Experiment (NSTX) operations and Tokamak Fusion Test Reactor (TFTR) dismantlement and deconstruction activities. A collaboration among fourteen national laboratories, universities, and research institutions, the NSTX is a major element in the U.S. Fusion Energy Sciences Program. It has been designed to test the physics principles of spherical torus (ST) plasmas. The ST concept could play an important role in the development of smaller, more economical fusion reactors. In 2001, PPPL's radiological environmental monitoring program measured tritium in the air at on- and off-site sampling stations. PPPL is capable of detecting small changes in the ambient levels of tritium by using highly sensitive monitors. The operation of an in-stack monitor located on D-site is a requirement of the National Emission Standard for Hazardous Air Pollutants (NESHAPs) regulations; also included in PPPL's radiological environmental monitoring program, are water monitoring--precipitation, ground-, surface-, and waste-waters. PPPL's radiological monitoring program characterized the ambient, background levels of tritium in the environment and from the D-site stack; the data are presented in this report. Groundwater monitoring continue d under a voluntary agreement with the New Jersey Department of Environmental Protection. PPPL monitored for the presence of nonradiological contaminants, mainly volatile organic compounds (components of degreasing solvents). Monitoring revealed the low levels of volatile organic compounds in an area adjacent to PPPL. In 2001, PPPL was in compliance with its permit limits for surface and sanitary discharges and had no reportable releases. Additionally, as part of DOE's program for the purchase of recycled content and other environmentally preferred products, PPPL has ranked in the excellent category of 80 to 90% of the goal.« less

Dual control of low concentration CO poisoning by anode air bleeding of low temperature polymer electrolyte membrane fuel cells

NASA Astrophysics Data System (ADS)

Klages, Merle; Tjønnås, Johannes; Zenith, Federico; Halvorsen, Ivar J.; Scholta, Joachim

2016-12-01

Fuel impurities, fed to a polymer electrolyte membrane fuel cell, can affect stack performance by poisoning of catalyst layers. This paper describes the dynamic behaviour of a stack, including state-of-the-art membrane electrode assemblies (MEA) of three different manufacturers, at different operating conditions. The voltage transients of the step responses to CO poisoning as well as air bleed recovery are compared, revealing differences in performance loss: slow poisoning versus fast recovery, incomplete recovery and voltage oscillation. The recorded behaviour is used to develop a model, based on Tafel equation and first order dynamic response, which can be calibrated to each MEA type. Using this model to predict voltage response, a controller is built with the aim of reducing the total amount of air bleed and monitoring upstream stack processes without the need of sensors measuring the poisoning level. Two controllers are implemented in order to show the concept from a heuristic, easy to implement, and a more technical side allowing more detailed analysis of the synthesis. The heuristic algorithm, based on periodic perturbations of the manipulated variable (air-bleed), is validated on a real stack, revealing a stabilized performance without the need of detailed stack properties knowledge.

33. VIEW OF FOUR OF SEVEN MONITORS SUSPENDED FROM CEILING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

33. VIEW OF FOUR OF SEVEN MONITORS SUSPENDED FROM CEILING OF SLC-3W CONTROL ROOM NEAR NORTH WALL. LEFT TO RIGHT ABOVE THE MONITORS: DIGITAL GREENWICH MEAN TIME CLOCK, COMPLEX SAFETY WARNING LIGHTS FOR SLC-3W (PAD-2) AND LOB (THE GREEN LIGHT ON THE BOTTOM OF EACH STACK IS ILLUMINATED), AND DIGITAL COUNTDOWN AND HOLD CLOCKS. LEFT TO RIGHT BELOW THE MONITORS: INDICATOR LIGHTS SHOWING WHICH PAD OR VEHICLE FACILITIES ARE RECEIVING POWER FROM POWER PLANT 4 ON SOUTH VAFB, LIGHTS TO INDICATE IF POWER PLANT 4 IS ON OR OFF LINE, DIGITAL COUNTDOWN CLOCK, AND MILITARY-TIME CLOCK. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

The Direct FuelCell™ stack engineering

NASA Astrophysics Data System (ADS)

Doyon, J.; Farooque, M.; Maru, H.

FuelCell Energy (FCE) has developed power plants in the size range of 300 kW to 3 MW for distributed power generation. Field-testing of the sub-megawatt plants is underway. The FCE power plants are based on its Direct FuelCell™ (DFC) technology. This is so named because of its ability to generate electricity directly from a hydrocarbon fuel, such as natural gas, by reforming it inside the fuel cell stack itself. All FCE products use identical 8000 cm 2 cell design, approximately 350-400 cells per stack, external gas manifolds, and similar stack compression systems. The difference lies in the packaging of the stacks inside the stack module. The sub-megawatt system stack module contains a single horizontal stack whereas the MW-class stack module houses four identical vertical stacks. The commonality of the design, internal reforming features, and atmospheric operation simplify the system design, reduce cost, improve efficiency, increase reliability and maintainability. The product building-block stack design has been advanced through three full-size stack operations at company's headquarters in Danbury, CT. The initial proof-of-concept of the full-size stack design was verified in 1999, followed by a 1.5 year of endurance verification in 2000-2001, and currently a value-engineered stack version is in operation. This paper discusses the design features, important engineering solutions implemented, and test results of FCE's full-size DFC stacks.

Final technical report. In-situ FT-IR monitoring of a black liquor recovery boiler

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

James Markham; Joseph Cosgrove; David Marran

1999-05-31

This project developed and tested advanced Fourier transform infrared (FT-IR) instruments for process monitoring of black liquor recovery boilers. The state-of-the-art FT-IR instruments successfully operated in the harsh environment of a black liquor recovery boiler and provided a wealth of real-time process information. Concentrations of multiple gas species were simultaneously monitored in-situ across the combustion flow of the boiler and extractively at the stack. Sensitivity to changes of particulate fume and carryover levels in the process flow were also demonstrated. Boiler set-up and operation is a complex balance of conditions that influence the chemical and physical processes in the combustionmore » flow. Operating parameters include black liquor flow rate, liquor temperature, nozzle pressure, primary air, secondary air, tertiary air, boiler excess oxygen and others. The in-process information provided by the FT-IR monitors can be used as a boiler control tool since species indicative of combustion efficiency (carbon monoxide, methane) and pollutant emissions (sulfur dioxide, hydrochloric acid and fume) were monitored in real-time and observed to fluctuate as operating conditions were varied. A high priority need of the U.S. industrial boiler market is improved measurement and control technology. The sensor technology demonstrated in this project is applicable to the need of industry.« less

40 CFR 75.72 - Determination of NOX mass emissions for common stack and multiple stack configurations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Determination of NOX mass emissions... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING NOX Mass Emissions Provisions § 75.72 Determination of NOX mass emissions for common stack and multiple stack...

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

Virginia L. Finley

The results of the 2000 environmental surveillance and monitoring program for the Princeton Plasma Physics Laboratory (PPPL) are presented and discussed. The purpose of this report is to provide the U.S. Department of Energy and the public with information on the level of radioactive and nonradioactive pollutants (if any) that are added to the environment as a result of PPPL's operations. The report also summarizes environmental initiatives, assessments, and programs that were undertaken in 2000. The Princeton Plasma Physics Laboratory has engaged in fusion energy research since 1951. The long-range goal of the U.S. Magnetic Fusion Energy Research Program ismore » to create innovations to make fusion power a practical reality -- an alternative energy source. The year 2000 marked the second year of National Spherical Torus Experiment (NSTX) operations and Tokamak Fusion Test Reactor (TFTR) dismantlement and deconstruction activities. A collaboration among fourteen national laboratories, universities, and research institutions, the NSTX is a major element in the U.S. Fusion Energy Sciences Program. It has been designed to test the physics principles of spherical torus (ST) plasmas. The ST concept could play an important role in the development of smaller, more economical fusion power plants. With its completion within budget and ahead of its target schedule, NSTX first plasma occurred on February 12, 1999. In 2000, PPPL's radiological environmental monitoring program measured tritium in the air at on-site and off-site sampling stations. PPPL is capable of detecting small changes in the ambient levels of tritium by using highly sensitive monitors. The operation of an in-stack monitor located on D-site is a requirement of the National Emission Standard for Hazardous Air Pollutants (NESHAPs) regulations with limits set by the Environmental Protection Agency (EPA). Also included in PPPL's radiological environmental monitoring program, are precipitation, surface, ground, a nd waste water monitoring. Groundwater investigations continued under a voluntary agreement with the New Jersey Department of Environmental Protection. PPPL monitored for the presence of nonradiological contaminants, mainly volatile organic compounds (components of degreasing solvents). Monitoring revealed the presence of low levels of volatile organic compounds in an area adjacent to PPPL. Also, PPPL's radiological monitoring program characterized the ambient, background levels of tritium in the environment and from the D-site stack; the data are presented in this report.« less

Redox flow cell energy storage systems

NASA Technical Reports Server (NTRS)

Thaller, L. H.

1979-01-01

NASA-Redox systems are electrochemical storage devices that use two fully soluble Redox couples, anode and cathode fluids, as active electrode materials separated by a highly selective ion exchange membrane. The reactants are contained in large storage tanks and pumped through a stack of Redox flow cells where the electrochemical reactions (reduction and oxidation) take place at porous carbon felt electrodes. A string or stack of these power producing cells is connected in series in a bipolar manner. Redox energy storage systems promise to be inexpensive and possess many features that provide for flexible design, long life, high reliability and minimal operation and maintenance costs. These features include independent sizing of power and storage capacity requirements and inclusion within the cell stack of a cell that monitors the state of charge of the system as a whole, and a rebalance cell which permits continuous correction to be made for minor side reactions that would tend to result in the anode fluid and cathode fluids becoming electrochemically out of balance. These system features are described and discussed.

Stack Flow Rate Changes and the ANSI/N13.1-1999 Qualification Criteria: Application to the Hanford Canister Storage Building Stack

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

Flaherty, Julia E.; Glissmeyer, John A.

2016-02-29

The Canister Storage Building (CSB), located in the 200-East Area of the Hanford Site, is a 42,000 square foot facility used to store spent nuclear fuel from past activities at the Hanford Site. Because the facility has the potential to emit radionuclides into the environment, its ventilation exhaust stack has been equipped with an air monitoring system. Subpart H of the National Emissions Standards for Hazardous Air Pollutants requires that a sampling probe be located in the exhaust stack in accordance with criteria established by the American National Standards Institute/Health Physics Society Standard N13.1-1999, Sampling and Monitoring Releases of Airbornemore » Radioactive Substances from the Stack and Ducts of Nuclear Facilities.« less

A review of polymer electrolyte membrane fuel cell stack testing

NASA Astrophysics Data System (ADS)

Miller, M.; Bazylak, A.

This paper presents an overview of polymer electrolyte membrane fuel cell (PEMFC) stack testing. Stack testing is critical for evaluating and demonstrating the viability and durability required for commercial applications. Single cell performance cannot be employed alone to fully derive the expected performance of PEMFC stacks, due to the non-uniformity in potential, temperature, and reactant and product flow distributions observed in stacks. In this paper, we provide a comprehensive review of the state-of-the art in PEMFC testing. We discuss the main topics of investigation, including single cell vs. stack-level performance, cell voltage uniformity, influence of operating conditions, durability and degradation, dynamic operation, and stack demonstrations. We also present opportunities for future work, including the need to verify the impact of stack size and cell voltage uniformity on performance, determine operating conditions for achieving a balance between electrical efficiency and flooding/dry-out, meet lifetime requirements through endurance testing, and develop a stronger understanding of degradation.

Assessment of the National Research Universal Reactor Proposed New Stack Sampling Probe Location for Compliance with ANSI/HPS N13.1-1999

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

Glissmeyer, John A.; Antonio, Ernest J.; Flaherty, Julia E.

2016-02-29

This document reports on a series of tests conducted to assess the proposed air sampling location for the National Research Universal reactor (NRU) complex exhaust stack, located in Chalk River, Ontario, Canada, with respect to the applicable criteria regarding the placement of an air sampling probe. Due to the age of the equipment in the existing monitoring system, and the increasing difficulty in acquiring replacement parts to maintain this equipment, a more up-to-date system is planned to replace the current effluent monitoring system, and a new monitoring location has been proposed. The new sampling probe should be located within themore » exhaust stack according to the criteria established by the American National Standards Institute/Health Physics Society (ANSI/HPS) N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities. These criteria address the capability of the sampling probe to extract a sample that represents the effluent stream. The internal Pacific Northwest National Laboratory (PNNL) project for this task was 65167, Atomic Energy Canada Ltd. Chalk River Effluent Duct Flow Qualification. The testing described in this document was guided by the Test Plan: Testing of the NRU Stack Air Sampling Position (TP-STMON-032).« less

A new approach for biological online testing of stack gas condensate from municipal waste incinerators.

PubMed

Elsner, Dorothea; Fomin, Anette

2002-01-01

A biological testing system for the monitoring of stack gas condensates of municipal waste incinerators has been developed using Euglena gracilis as a test organism. The motility, velocity and cellular form of the organisms were the endpoints, calculated by an image analysis system. All endpoints showed statistically significant changes in a short time when organisms were exposed to samples collected during combustion situations with increased pollutant concentrations. The velocity of the organisms proved to be the most appropriate endpoint. A semi-continuous system with E. gracilis for monitoring stack gas condensate is proposed, which could result in an online system for testing stack gas condensates in the future.

Study of medical isotope production facility stack emissions and noble gas isotopic signature using automatic gamma-spectra analysis platform

NASA Astrophysics Data System (ADS)

Zhang, Weihua; Hoffmann, Emmy; Ungar, Kurt; Dolinar, George; Miley, Harry; Mekarski, Pawel; Schrom, Brian; Hoffman, Ian; Lawrie, Ryan; Loosz, Tom

2013-04-01

The nuclear industry emissions of the four CTBT (Comprehensive Nuclear-Test-Ban Treaty) relevant radioxenon isotopes are unavoidably detected by the IMS along with possible treaty violations. Another civil source of radioxenon emissions which contributes to the global background is radiopharmaceutical production companies. To better understand the source terms of these background emissions, a joint project between HC, ANSTO, PNNL and CRL was formed to install real-time detection systems to support 135Xe, 133Xe, 131mXe and 133mXe measurements at the ANSTO and CRL 99Mo production facility stacks as well as the CANDU (CANada Deuterium Uranium) primary coolant monitoring system at CRL. At each site, high resolution gamma spectra were collected every 15 minutes using a HPGe detector to continuously monitor a bypass feed from the stack or CANDU primary coolant system as it passed through a sampling cell. HC also conducted atmospheric monitoring for radioxenon at approximately 200 km distant from CRL. A program was written to transfer each spectrum into a text file format suitable for the automatic gamma-spectra analysis platform and then email the file to a server. Once the email was received by the server, it was automatically analysed with the gamma-spectrum software UniSampo/Shaman to perform radionuclide identification and activity calculation for a large number of gamma-spectra in a short period of time (less than 10 seconds per spectrum). The results of nuclide activity together with other spectrum parameters were saved into the Linssi database. This database contains a large amount of radionuclide information which is a valuable resource for the analysis of radionuclide distribution within the noble gas fission product emissions. The results could be useful to identify the specific mechanisms of the activity release. The isotopic signatures of the various radioxenon species can be determined as a function of release time. Comparison of 133mXe and 133Xe activity ratios showed distinct differences between the closed CANDU primary coolant system and radiopharmaceutical production releases. According to the concept proposed by Kalinowski and Pistner (2006), the relationship between different isotopic activity ratios based on three or four radioxenon isotopes was plotted in a log-log diagram for source characterisation (civil vs. nuclear test). The multiple isotopic activity ratios were distributed in three distinct areas: HC atmospheric monitoring ratios extended to far left; the CANDU primary coolant system ratios lay in the middle; and 99Mo stack monitoring ratios for ANSTO and CRL were located on the right. The closed CANDU primary coolant has the lowest logarithmic mean ratio that represents the nuclear power reactor operation. The HC atmospheric monitoring exhibited a broad range of ratios spreading over several orders of magnitude. In contrast, the ANSTO and CRL stack emissions showed the smallest range of ratios but the results indicate at least two processes involved in the 99Mo productions. Overall, most measurements were found to be shifted towards the reactor domain. The hypothesis is that this is due to an accumulation of the isotope 131mXe in the stack or atmospheric background as it has the longest half-life and extra 131mXe emissions from the decay of 131I. The contribution of older 131mXe to a fresh release shifts the ratio of 133mXe/131mXe to the left. It was also very interesting to note that there were some situations where isotopic ratios from 99Mo production emissions fell within the nuclear test domain. This is due to operational variability, such as shorter target irradiation times. Martin B. Kalinowski and Christoph Pistner, (2006), Isotopic signature of atmospheric xenon released from light water reactors, Journal of Environmental Radioactivity, 88, 215-235.

Improvement of electricity generating performance and life expectancy of MCFC stack by applying Li/Na carbonate electrolyte. Test results and analysis of 0.44 m 2/10 kW- and 1.03 m 2/10 kW-class stack

NASA Astrophysics Data System (ADS)

Yoshiba, Fumihiko; Morita, Hiroshi; Yoshikawa, Masahiro; Mugikura, Yoshihiro; Izaki, Yoshiyuki; Watanabe, Takao; Komoda, Mineo; Masuda, Yuji; Zaima, Nobuyuki

Following the development of a 10 kW-class MCFC stack with a reactive area of 0.44 and 1.03 m 2, which applies a Li/Na carbonate electrolyte and a press stamping separator, many tests have now been carried out. In the installation tests, the observed cell voltages of the 0.44 m 2/10 kW-class stack agreed with the voltage predicted from the test results of the 100 cm 2 bench scale cell. This agreement proves that the installing procedure of the bench scale cell can be applied to the 0.44 m 2/10 kW-class stacks. The temperature distribution analysis model applied to the 100 kW-class stack was modified to calculate the temperature distribution of the 0.44 m 2/10 kW-class stack. Taking the heat loss and the heat transfer effect of the stack holder into account, the calculated temperature was close to the measured temperature; this result proves that the modification was adequate for the temperature analysis model. In the high current density operating tests on the 0.44 m 2/10 kW-class stack, an electrical power density of 2.46 kW/m 2 was recorded at an operating current density of 3000 A/m 2. In the endurance test on the 0.44 m 2/10 kW-class stack, however, unexpected Ni shortening occurred during the operating period 2500-4500 h, which had been caused by a defective formation of the electrolyte matrix. The shortening seems to have been caused by the crack, which appeared in the electrolyte matrix. The voltage degradation rate of the 0.44 m 2/10 kW-class stack was 0.52% over 1000 h, which proves that the matrix was inadequate for a long life expectancy of the MCFC stack. A final endurance test was carried out on the 1.03 m 2/10 kW-class stack, of which the matrix had been revised. The fuel utilisation and the leakage of anode gas never changed during the 10,000 h operating test. This result suggests that no shortening occurred during the 10,000 h endurance test. The cell voltage degradation rate was around 0.2-0.3% over 1000 h in the 1.03 m 2/10 kW-class stack. According to a comparison of the stack electricity generating performance of the 0.44 m 2 and the 1.03 m 2/10 kW-class stack under the same operating conditions, the performance of the 1.03 m 2 stack was lower at the beginning of the endurance test, however, its performance exceeded the performance of the 0.44 m 2/10 kW-class stack during the 10,000 h operating test. By carrying out the high current density operating test and the 10,000-hour endurance test using commercial sized 10 kW-class stacks, the stability of the MCFC stack with a Li/Na carbonate electrolyte and a press stamping separator has been proven.

Gaseous and particulate emissions from thermal power plants operating on different technologies.

PubMed

Athar, Makshoof; Ali, Mahboob; Khan, Misbahul Ain

2010-07-01

This paper presents the assessment of gaseous and particulate emissions from thermal power plants operating on different combustion technologies. Four thermal power plants operating on heavy furnace oil were selected for the study, among which three were based on diesel engine technology, while the fourth plant was based on oil-fired steam turbine technology. The stack emissions were monitored for critical air pollutants carbon monoxide, carbon dioxide, oxides of nitrogen, sulfur dioxide, particulate matter, lead, and mercury. The pollutant emissions were measured at optimum load conditions for a period of 6 months with an interval of 1 month. The results of stack emissions were compared with National Environmental Quality Standards of Pakistan and World Bank guidelines for thermal power plants, and few parameters were found higher than the permissible limits of emissions. It was observed that the emissions carbon monoxide, oxides of nitrogen, and particulate matters from diesel engine-based power plants were comparatively higher than the turbine-based power plants. The emissions of sulfur dioxide were high in all the plants, even the plants with different technologies, which was mainly due to high sulfur contents in fuel.

Probing Temperature Inside Planar SOFC Short Stack, Modules, and Stack Series

NASA Astrophysics Data System (ADS)

Yu, Rong; Guan, Wanbing; Zhou, Xiao-Dong

2017-02-01

Probing temperature inside a solid oxide fuel cell (SOFC) stack lies at the heart of the development of high-performance and stable SOFC systems. In this article, we report our recent work on the direct measurements of the temperature in three types of SOFC systems: a 5-cell short stack, a 30-cell stack module, and a stack series consisting of two 30-cell stack modules. The dependence of temperature on the gas flow rate and current density was studied under a current sweep or steady-state operation. During the current sweep, the temperature inside the 5-cell stack decreased with increasing current, while it increased significantly at the bottom and top of the 30-cell stack. During a steady-state operation, the temperature of the 5-cell stack was stable while it was increased in the 30-cell stack. In the stack series, the maximum temperature gradient reached 190°C when the gas was not preheated. If the gas was preheated and the temperature gradient was reduced to 23°C in the stack series with the presence of a preheating gas and segmented temperature control, this resulted in a low degradation rate.

The Deep Impact Network Experiment Operations Center Monitor and Control System

NASA Technical Reports Server (NTRS)

Wang, Shin-Ywan (Cindy); Torgerson, J. Leigh; Schoolcraft, Joshua; Brenman, Yan

2009-01-01

The Interplanetary Overlay Network (ION) software at JPL is an implementation of Delay/Disruption Tolerant Networking (DTN) which has been proposed as an interplanetary protocol to support space communication. The JPL Deep Impact Network (DINET) is a technology development experiment intended to increase the technical readiness of the JPL implemented ION suite. The DINET Experiment Operations Center (EOC) developed by JPL's Protocol Technology Lab (PTL) was critical in accomplishing the experiment. EOC, containing all end nodes of simulated spaces and one administrative node, exercised publish and subscribe functions for payload data among all end nodes to verify the effectiveness of data exchange over ION protocol stacks. A Monitor and Control System was created and installed on the administrative node as a multi-tiered internet-based Web application to support the Deep Impact Network Experiment by allowing monitoring and analysis of the data delivery and statistics from ION. This Monitor and Control System includes the capability of receiving protocol status messages, classifying and storing status messages into a database from the ION simulation network, and providing web interfaces for viewing the live results in addition to interactive database queries.

Investigation of Ruthenium Dissolution in Advanced Membrane Electrode Assemblies for Direct Methanol Based Fuel Cell Stacks

NASA Technical Reports Server (NTRS)

Valdez, Thomas I.; Firdosy, S.; Koel, B. E.; Narayanan, S. R.

2005-01-01

Dissolution of ruthenium was observed in the 80-cell stack. Duration testing was performed in single cell MEAs to determine the pathway of cell degradation. EDAX analysis on each of the single cell MEAs has shown that the Johnson Matthey commercial catalyst is stable in DMFC operation for 250 hours, no ruthenium dissolution was observed. Changes in the hydrophobicity of the cathode backing papers was minimum. Electrode polarization analysis revealed that the MEA performance loss is attributed to changes in the cathode catalyst layer. Ruthenium migration does not seem to occur during cell operation but can occur when methanol is absent from the anode compartment, the cathode compartment has access to air, and the cells in the stack are electrically connected to a load (Shunt Currents). The open-to-air cathode stack design allowed for: a) The MEAs to have continual access to oxygen; and b) The stack to sustain shunt currents. Ruthenium dissolution in a DMFC stack can be prevented by: a) Developing an internally manifolded stacks that seal reactant compartments when not in operation; b) Bringing the cell voltages to zero quickly when not in operation; and c) Limiting the total number of cells to 25 in an effort to limit shunt currents.

Application of Radioxenon Stack Emission Data in High-Resolution Atmospheric Transport Modelling

NASA Astrophysics Data System (ADS)

Kusmierczyk-Michulec, J.; Schoeppner, M.; Kalinowski, M.; Bourgouin, P.; Kushida, N.; Barè, J.

2017-12-01

The Comprehensive Nuclear-Test-Ban Treaty Organisation (CTBTO) has developed the capability to run high-resolution atmospheric transport modelling by employing WRF and Flexpart-WRF. This new capability is applied to simulate the impact of stack emission data on simulated concentrations and how the availability of such data improves the overall accuracy of atmospheric transport modelling. The presented case study focuses on xenon-133 emissions from IRE, a medical isotope production facility in Belgium, and air concentrations detected at DEX33, a monitoring station close to Freiburg, Germany. The CTBTO is currently monitoring the atmospheric concentration of xenon-133 at 25 stations and will further expand the monitoring efforts to 40 stations worldwide. The incentive is the ability to detect xenon-133 that has been produced and released from a nuclear explosion. A successful detection can be used to prove the nuclear nature of an explosion and even support localization efforts. However, xenon-133 is also released from nuclear power plants and to a larger degree from medical isotope production facilities. The availability of stack emission data in combination with atmospheric transport modelling can greatly facilitate the understanding of xenon-133 concentrations detected at monitoring stations to distinguish between xenon-133 that has been emitted from a nuclear explosion and from civilian sources. Newly available stack emission data is used with a high-resolution version of the Flexpart atmospheric transport model, namely Flexpart-WRF, to assess the impact of the emissions on the detected concentrations and the advantage gained from the availability of such stack emission data. The results are analyzed with regard to spatial and time resolution of the high-resolution model and in comparison to conventional atmospheric transport models with and without stack emission data.

30 CFR 250.441 - What are the requirements for a surface BOP stack?

Code of Federal Regulations, 2011 CFR

2011-07-01

... ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Blowout Preventer (bop) System Requirements § 250.441 What are the requirements for a surface BOP stack? (a) When you drill with a surface BOP stack, you must install the BOP...

30 CFR 250.441 - What are the requirements for a surface BOP stack?

Code of Federal Regulations, 2012 CFR

2012-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Blowout Preventer (bop) System Requirements § 250.441 What are the requirements for a surface BOP stack? (a) When you drill with a surface BOP stack, you must install the BOP...

30 CFR 250.441 - What are the requirements for a surface BOP stack?

Code of Federal Regulations, 2014 CFR

2014-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Blowout Preventer (bop) System Requirements § 250.441 What are the requirements for a surface BOP stack? (a) When you drill with a surface BOP stack, you must install the BOP...

30 CFR 250.441 - What are the requirements for a surface BOP stack?

Code of Federal Regulations, 2013 CFR

2013-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Blowout Preventer (bop) System Requirements § 250.441 What are the requirements for a surface BOP stack? (a) When you drill with a surface BOP stack, you must install the BOP...

A computer system to analyze showers in nuclear emulsions: Center Director's discretionary fund report

NASA Technical Reports Server (NTRS)

Meegan, C. A.; Fountain, W. F.; Berry, F. A., Jr.

1987-01-01

A system to rapidly digitize data from showers in nuclear emulsions is described. A TV camera views the emulsions though a microscope. The TV output is superimposed on the monitor of a minicomputer. The operator uses the computer's graphics capability to mark the positions of particle tracks. The coordinates of each track are stored on a disk. The computer then predicts the coordinates of each track through successive layers of emulsion. The operator, guided by the predictions, thus tracks and stores the development of the shower. The system provides a significant improvement over purely manual methods of recording shower development in nuclear emulsion stacks.

40 CFR 75.16 - Special provisions for monitoring emissions from common, bypass, and multiple stacks for SO2...

Code of Federal Regulations, 2011 CFR

2011-07-01

... emissions from common, bypass, and multiple stacks for SO2 emissions and heat input determinations. 75.16... emissions from common, bypass, and multiple stacks for SO2 emissions and heat input determinations. (a... by the Administrator, such that these emissions are not underestimated. (e) Heat input rate. The...

40 CFR 75.16 - Special provisions for monitoring emissions from common, bypass, and multiple stacks for SO 2...

Code of Federal Regulations, 2013 CFR

2013-07-01

... emissions from common, bypass, and multiple stacks for SO 2 emissions and heat input determinations. 75.16... emissions from common, bypass, and multiple stacks for SO 2 emissions and heat input determinations. (a... by the Administrator, such that these emissions are not underestimated. (e) Heat input rate. The...

40 CFR 75.16 - Special provisions for monitoring emissions from common, bypass, and multiple stacks for SO2...

Code of Federal Regulations, 2012 CFR

2012-07-01

... emissions from common, bypass, and multiple stacks for SO2 emissions and heat input determinations. 75.16... emissions from common, bypass, and multiple stacks for SO2 emissions and heat input determinations. (a... by the Administrator, such that these emissions are not underestimated. (e) Heat input rate. The...

40 CFR 75.16 - Special provisions for monitoring emissions from common, bypass, and multiple stacks for SO 2...

Code of Federal Regulations, 2014 CFR

2014-07-01

... emissions from common, bypass, and multiple stacks for SO 2 emissions and heat input determinations. 75.16... emissions from common, bypass, and multiple stacks for SO 2 emissions and heat input determinations. (a... by the Administrator, such that these emissions are not underestimated. (e) Heat input rate. The...

Monitoring Iodine-129 in Air and Milk Samples Collected Near the Hanford Site: An Investigation of Historical Iodine Monitoring Data

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

Fritz, Brad G.; Patton, Gregory W.

2006-01-01

While other research has reported on the concentrations of 129I in the environment surrounding active nuclear fuel reprocessing facilities, there is a shortage of information regarding how the concentrations change once facilities close. At the Hanford Site, the Plutonium-Uranium Extraction (PUREX) chemical separation plant was operational between 1983 and 1990, during which time 129I concentrations in air and milk were measured. After the cessation of operations in 1990, plant emissions decreased 2.5 orders of magnitude over an 8 year period, and monitoring of environmental levels continued. An evaluation of air and milk 129I concentration data spanning the PUREX operation andmore » post closure period was conducted to compare the changes in environmental levels of 129I measured. Measured concentrations over the monitoring period were below levels that could result in a potential human dose greater than 10 uSv. There was a significant and measurable difference in the measured air concentrations of 129I at different distances from the source, indicating a distinct Hanford fingerprint. Correlations between stack emissions of 129I and concentrations in air and milk indicate that atmospheric emissions were responsible for the 129I concentrations measured in environmental samples. The measured concentrations during PUREX operation were similar to observations made around a fuel reprocessing plant in Germany.« less

SRB Stack Training

NASA Image and Video Library

2018-01-30

Crane operators and ground support personnel practice lifting and stacking mock-ups of solid rocket booster (SRB) segments in High Bay 4 inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida. The training will help workers prepare for SRB stacking operations for the agency's Space Launch System SLS) rocket. The SLS will launch the Orion spacecraft on its first integrated flight, Exploration Mission-1.

PEM fuel cell stack heat and mass management

NASA Technical Reports Server (NTRS)

Vanderborgh, Nicholas E.; Kimble, Michael C.; Huff, James R.; Hedstrom, James C.

1992-01-01

PEM stacks are under evaluation as candidates for future space power technology. Results of long-term operation on a set of contemporary stacks fitted with different proton exchange membrane materials are given. Data on water balances show effects of membrane materials on stack performance.

Fuel cell stack arrangements

DOEpatents

Kothmann, Richard E.; Somers, Edward V.

1982-01-01

Arrangements of stacks of fuel cells and ducts, for fuel cells operating with separate fuel, oxidant and coolant streams. An even number of stacks are arranged generally end-to-end in a loop. Ducts located at the juncture of consecutive stacks of the loop feed oxidant or fuel to or from the two consecutive stacks, each individual duct communicating with two stacks. A coolant fluid flows from outside the loop, into and through cooling channels of the stack, and is discharged into an enclosure duct formed within the loop by the stacks and seals at the junctures at the stacks.

Monolithic stacked blue light-emitting diodes with polarization-enhanced tunnel junctions.

PubMed

Kuo, Yen-Kuang; Shih, Ya-Hsuan; Chang, Jih-Yuan; Lai, Wei-Chih; Liu, Heng; Chen, Fang-Ming; Lee, Ming-Lun; Sheu, Jinn-Kong

2017-08-07

Monolithic stacked InGaN light-emitting diode (LED) connected by a polarization-enhanced GaN/AlN-based tunnel junction is demonstrated experimentally in this study. The typical stacked LEDs exhibit 80% enhancement in output power compared with conventional single LEDs because of the repeated use of electrons and holes for photon generation. The typical operation voltage of stacked LEDs is higher than twice the operation voltage of single LEDs. This high operation voltage can be attributed to the non-optimal tunneling junction in stacked LEDs. In addition to the analyses of experimental results, theoretical analysis of different schemes of tunnel junctions, including diagrams of energy bands, diagrams of electric fields, and current-voltage relation curves, are investigated using numerical simulation. The results shown in this paper demonstrate the feasibility in developing cost-effective and highly efficient tunnel-junction LEDs.

Application of open-path Fourier transform infrared spectroscopy for atmospheric monitoring of a CO2 back-production experiment at the Ketzin pilot site (Germany).

PubMed

Sauer, Uta; Borsdorf, H; Dietrich, P; Liebscher, A; Möller, I; Martens, S; Möller, F; Schlömer, S; Schütze, C

2018-02-03

During a controlled "back-production experiment" in October 2014 at the Ketzin pilot site, formerly injected CO 2 was retrieved from the storage formation and directly released to the atmosphere via a vent-off stack. Open-path Fourier transform infrared (OP FTIR) spectrometers, on-site meteorological parameter acquisition systems, and distributed CO 2 point sensors monitored gas dispersion processes in the near-surface part of the atmospheric boundary layer. The test site provides a complex and challenging mosaic-like surface setting for atmospheric monitoring which can also be found at other storage sites. The main aims of the atmospheric monitoring of this experiment were (1) to quantify temporal and spatial variations in atmospheric CO 2 concentrations around the emitting vent-off stack and (2) to test if and how atmospheric monitoring can cope with typical environmental and operational challenges. A low environmental risk was encountered during the whole CO 2 back-production experiment. The study confirms that turbulent wind conditions favor atmospheric mixing processes and are responsible for rapid dilution of the released CO 2 leading to decreased detectability at all sensors. In contrast, calm and extremely stable wind conditions (especially occurring during the night) caused an accumulation of gases in the near-ground atmospheric layer with the highest amplitudes in measured gas concentration. As an important benefit of OP FTIR spectroscopic measurements and their ability to detect multiple gas species simultaneously, emission sources could be identified to a much higher certainty. Moreover, even simulation models using simplified assumptions help to find suitable monitoring network designs and support data analysis for certain wind conditions in such a complex environment.

Electrochemical cell stack assembly

DOEpatents

Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

2010-06-22

Multiple stacks of tubular electrochemical cells having a dense electrolyte disposed between an anode and a cathode preferably deposited as thin films arranged in parallel on stamped conductive interconnect sheets or ferrules. The stack allows one or more electrochemical cell to malfunction without disabling the entire stack. Stack efficiency is enhanced through simplified gas manifolding, gas recycling, reduced operating temperature and improved heat distribution.

Multi-channel temperature measurement system for automotive battery stack

NASA Astrophysics Data System (ADS)

Lewczuk, Radoslaw; Wojtkowski, Wojciech

2017-08-01

A multi-channel temperature measurement system for monitoring of automotive battery stack is presented in the paper. The presented system is a complete battery temperature measuring system for hybrid / electric vehicles that incorporates multi-channel temperature measurements with digital temperature sensors communicating through 1-Wire buses, individual 1-Wire bus for each sensor for parallel computing (parallel measurements instead of sequential), FPGA device which collects data from sensors and translates it for CAN bus frames. CAN bus is incorporated for communication with car Battery Management System and uses additional CAN bus controller which communicates with FPGA device through SPI bus. The described system can parallel measure up to 12 temperatures but can be easily extended in the future in case of additional needs. The structure of the system as well as particular devices are described in the paper. Selected results of experimental investigations which show proper operation of the system are presented as well.

Invited Article: Narrowband terahertz bandpass filters employing stacked bilayer metasurface antireflection structures

NASA Astrophysics Data System (ADS)

Chang, Chun-Chieh; Huang, Li; Nogan, John; Chen, Hou-Tong

2018-05-01

We experimentally demonstrate high-performance narrowband terahertz (THz) bandpass filters through cascading multiple bilayer metasurface antireflection structures. Each bilayer metasurface, consisting of a square array of silicon pillars with a self-aligned top gold resonator-array and a complementary bottom gold slot-array, enables near-zero reflection and simultaneously close-to-unity single-band transmission at designed operational frequencies in the THz spectral region. The THz bandpass filters based on stacked bilayer metasurfaces allow a fairly narrow, high-transmission passband, and a fast roll-off to an extremely clean background outside the passband, thereby providing superior bandpass performance. The demonstrated scheme of narrowband THz bandpass filtering is of great importance for a variety of applications where spectrally clean, high THz transmission over a narrow bandwidth is desired, such as THz spectroscopy and imaging, molecular detection and monitoring, security screening, and THz wireless communications.

Invited Article: Narrowband terahertz bandpass filters employing stacked bilayer metasurface antireflection structures

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

Chang, Chun-Chieh; Huang, Li; Nogan, John

We experimentally demonstrate high-performance narrowband terahertz (THz) bandpass filters through cascading multiple bilayer metasurface antireflection structures. Each bilayer metasurface, consisting of a square array of silicon pillars with a self-aligned top gold resonator-array and a complementary bottom gold slot-array, enables near-zero reflection and simultaneously close-to-unity single-band transmission at designed operational frequencies in the THz spectral region. The THz bandpass filters based on stacked bilayer metasurfaces allow a fairly narrow, high-transmission passband, and a fast roll-off to an extremely clean background outside the passband, thereby providing superior bandpass performance. The demonstrated scheme of narrowband THz bandpass filtering is of great importancemore » for a variety of applications where spectrally clean, high THz transmission over a narrow bandwidth is desired, such as THz spectroscopy and imaging, molecular detection and monitoring, security screening, and THz wireless communications.« less

Invited Article: Narrowband terahertz bandpass filters employing stacked bilayer metasurface antireflection structures

DOE PAGES

Chang, Chun-Chieh; Huang, Li; Nogan, John; ...

2018-02-01

We experimentally demonstrate high-performance narrowband terahertz (THz) bandpass filters through cascading multiple bilayer metasurface antireflection structures. Each bilayer metasurface, consisting of a square array of silicon pillars with a self-aligned top gold resonator-array and a complementary bottom gold slot-array, enables near-zero reflection and simultaneously close-to-unity single-band transmission at designed operational frequencies in the THz spectral region. The THz bandpass filters based on stacked bilayer metasurfaces allow a fairly narrow, high-transmission passband, and a fast roll-off to an extremely clean background outside the passband, thereby providing superior bandpass performance. The demonstrated scheme of narrowband THz bandpass filtering is of great importancemore » for a variety of applications where spectrally clean, high THz transmission over a narrow bandwidth is desired, such as THz spectroscopy and imaging, molecular detection and monitoring, security screening, and THz wireless communications.« less

High Temperature Electrolysis Pressurized Experiment Design, Operation, and Results

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

J.E. O'Brien; X. Zhang; G.K. Housley

2012-09-01

A new facility has been developed at the Idaho National Laboratory for pressurized testing of solid oxide electrolysis stacks. Pressurized operation is envisioned for large-scale hydrogen production plants, yielding higher overall efficiencies when the hydrogen product is to be delivered at elevated pressure for tank storage or pipelines. Pressurized operation also supports higher mass flow rates of the process gases with smaller components. The test stand can accommodate planar cells with dimensions up to 8.5 cm x 8.5 cm and stacks of up to 25 cells. It is also suitable for testing other cell and stack geometries including tubular cells.more » The pressure boundary for these tests is a water-cooled spool-piece pressure vessel designed for operation up to 5 MPa. Pressurized operation of a ten-cell internally manifolded solid oxide electrolysis stack has been successfully demonstrated up 1.5 MPa. The stack is internally manifolded and operates in cross-flow with an inverted-U flow pattern. Feed-throughs for gas inlets/outlets, power, and instrumentation are all located in the bottom flange. The entire spool piece, with the exception of the bottom flange, can be lifted to allow access to the internal furnace and test fixture. Lifting is accomplished with a motorized threaded drive mechanism attached to a rigid structural frame. Stack mechanical compression is accomplished using springs that are located inside of the pressure boundary, but outside of the hot zone. Initial stack heatup and performance characterization occurs at ambient pressure followed by lowering and sealing of the pressure vessel and subsequent pressurization. Pressure equalization between the anode and cathode sides of the cells and the stack surroundings is ensured by combining all of the process gases downstream of the stack. Steady pressure is maintained by means of a backpressure regulator and a digital pressure controller. A full description of the pressurized test apparatus is provided in this report. Results of initial testing showed the expected increase in open-cell voltage associated with elevated pressure. However, stack performance in terms of area-specific resistance was enhanced at elevated pressure due to better gas diffusion through the porous electrodes of the cells. Some issues such as cracked cells and seals were encountered during testing. Full resolution of these issues will require additional testing to identify the optimum test configurations and protocols.« less

Assessment of the Revised 3410 Building Filtered Exhaust Stack Sampling Probe Location

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

Yu, Xiao-Ying; Recknagle, Kurtis P.; Glissmeyer, John A.

2013-12-01

In order to support the air emissions permit for the 3410 Building, Pacific Northwest National Laboratory performed a series of tests in the exhaust air discharge from the reconfigured 3410 Building Filtered Exhaust Stack. The objective was to determine whether the location of the air sampling probe for emissions monitoring meets the applicable regulatory criteria governing such effluent monitoring systems. In particular, the capability of the air sampling probe location to meet the acceptance criteria of ANSI/HPS N13.1-2011 , Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities was determined. The qualification criteriamore » for these types of stacks address 1) uniformity of air velocity, 2) sufficiently small flow angle with respect to the axis of the duct, 3) uniformity of tracer gas concentration, and 4) uniformity of tracer particle concentration. Testing was performed to conform to the quality requirements of NQA-1-2000. Fan configurations tested included all fan combinations of any two fans at a time. Most of the tests were conducted at the normal flow rate, while a small subset of tests was performed at a slightly higher flow rate achieved with the laboratory hood sashes fully open. The qualification criteria for an air monitoring probe location are taken from ANSI/HPS N13.1-2011 and are paraphrased as follows with key results summarized: 1. Angular Flow—The average air velocity angle must not deviate from the axis of the stack or duct by more than 20°. Our test results show that the mean angular flow angles at the center two-thirds of the ducts are smaller than 4.5% for all testing conditions. 2. Uniform Air Velocity—The acceptance criterion is that the COV of the air velocity must be ≤ 20% across the center two thirds of the area of the stack. Our results show that the COVs of the air velocity across the center two-thirds of the stack are smaller than 2.9% for all testing conditions. 3. Uniform Concentration of Tracer Gases—The uniformity of the concentration of potential contaminants is first tested using a tracer gas to represent gaseous effluents. The tracer is injected downstream of the fan outlets and at the junction downstream fan discharges meet. The acceptance criteria are that 1) the COV of the measured tracer gas concentration is ≤20% across the center two-thirds of the sampling plane and 2) at no point in the sampling plane does the concentration vary from the mean by >30%. Our test results show that 1) the COV of the measured tracer gas concentration is < 2.9% for all test conditions and 2) at no point in the sampling plane does the concentration vary from the mean by >6.5%. 4. Uniform Concentration of Tracer Particles—Tracer particles of 10-μm aerodynamic diameter are used for the second demonstration of concentration uniformity. The acceptance criterion is that the COV of particle concentration is ≤ 20% across the center two thirds of the sampling plane. Our test results indicate that the COV of particle concentration is <9.9% across the center two-thirds of the sampling plane among all testing conditions. Thus, the reconfigured 3410 Building Filtered Exhaust Stack was determined to meet the qualification criteria given in the ANSI/HPS N13.1-2011 standard. Changes to the system configuration or operations outside the bounds described in this report (e.g., exhaust stack velocity changes, relocation of sampling probe, and addition of fans) may require re-testing or re-evaluation to determine compliance.« less

Influence of the charge double layer on solid oxide fuel cell stack behavior

NASA Astrophysics Data System (ADS)

Whiston, Michael M.; Bilec, Melissa M.; Schaefer, Laura A.

2015-10-01

While the charge double layer effect has traditionally been characterized as a millisecond phenomenon, longer timescales may be possible under certain operating conditions. This study simulates the dynamic response of a previously developed solid oxide fuel cell (SOFC) stack model that incorporates the charge double layer via an equivalent circuit. The model is simulated under step load changes. Baseline conditions are first defined, followed by consideration of minor and major deviations from the baseline case. This study also investigates the behavior of the SOFC stack with a relatively large double layer capacitance value, as well as operation of the SOFC stack under proportional-integral (PI) control. Results indicate that the presence of the charge double layer influences the SOFC stack's settling time significantly under the following conditions: (i) activation and concentration polarizations are significantly increased, or (ii) a large value of the double layer capacitance is assumed. Under normal (baseline) operation, on the other hand, the charge double layer effect diminishes within milliseconds, as expected. It seems reasonable, then, to neglect the charge double layer under normal operation. However, careful consideration should be given to potential variations in operation or material properties that may give rise to longer electrochemical settling times.

High Temporal Resolution Permafrost Monitoring Using a Multiple Stack Insar Technique

NASA Astrophysics Data System (ADS)

Eppler, J.; Kubanski, M.; Sharma, J.; Busler, J.

2015-04-01

The combined effect of climate change and accelerated economic development in Northern regions increases the threat of permafrost related surface deformation to buildings and transportation infrastructure. Satellite based InSAR provides a means for monitoring infrastructure that may be both remote and spatially extensive. However, permafrost poses challenges for InSAR monitoring due to the complex temporal deformation patterns caused by both seasonal active layer fluctuations and long-term changes in permafrost thickness. These dynamics suggest a need for increasing the temporal resolution of multi-temporal InSAR methods. To address this issue we have developed a method that combines and jointly processes two or more same side geometry InSAR stacks to provide a high-temporal resolution estimate of surface deformation. The method allows for combining stacks from more than a single SAR sensor and for a combination of frequency bands. Data for this work have been collected and analysed for an area near the community of Umiujaq, Quebec in Northern Canada and include scenes from RADARSAT-2, TerraSAR-X and COSMO-SkyMed. Multiple stack based surface deformation estimates are compared for several cases including results from the three sensors individually and for all sensors combined. The test cases show substantially similar surface deformation results which correlate well with surficial geology. The best spatial coverage of coherent targets was achieved when data from all sensors were combined. The proposed multiple stack method is demonstrated to improve the estimation of surface deformation in permafrost affected areas and shows potential for deriving InSAR based permafrost classification maps to aid in the monitoring of Northern infrastructure.

2D fluorescence spectroscopy for monitoring ion-exchange membrane based technologies - Reverse electrodialysis (RED).

PubMed

Pawlowski, Sylwin; Galinha, Claudia F; Crespo, João G; Velizarov, Svetlozar

2016-01-01

Reverse electrodialysis (RED) is one of the emerging, membrane-based technologies for harvesting salinity gradient energy. In RED process, fouling is an undesirable operation constraint since it leads to a decrease of the obtainable net power density due to increasing stack electric resistance and pressure drop. Therefore, early fouling detection is one of the main challenges for successful RED technology implementation. In the present study, two-dimensional (2D) fluorescence spectroscopy was used, for the first time, as a tool for fouling monitoring in RED. Fluorescence excitation-emission matrices (EEMs) of ion-exchange membrane surfaces and of natural aqueous streams were acquired during one month of a RED stack operation. Fouling evolvement on the ion-exchange membrane surfaces was successfully followed by 2D fluorescence spectroscopy and quantified using principal components analysis (PCA). Additionally, the efficiency of cleaning strategy was assessed by measuring the membrane fluorescence emission intensity before and after cleaning. The anion-exchange membrane (AEM) surface in contact with river water showed to be significantly affected due to fouling by humic compounds, which were found to cross through the membrane from the lower salinity (river water) to higher salinity (sea water) stream. The results obtained show that the combined approach of using 2D fluorescence spectroscopy and PCA has a high potential for studying fouling development and membrane cleaning efficiency in ion exchange membrane processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Control of electrolyte fill to fuel cell stack

DOEpatents

Pollack, William

1982-01-01

A fuel cell stack which can be operated with cells in a horizontal position so that the fuel cell stack does not have to be taken out of operation when adding an electrolyte such as an acid. Acid is supplied to each matrix in a stack of fuel cells at a uniform, low pressure so that the matrix can either be filled initially or replenished with acid lost in operation of the cell, without exceeding the bubble pressure of the matrix or the flooding pressure of the electrodes on either side of the matrix. Acid control to each cell is achieved by restricting and offsetting the opening of electrolyte fill holes in the matrix relative to openings in the plates which sandwich the matrix and electrodes therebetween.

Sampled-time control of a microbial fuel cell stack

NASA Astrophysics Data System (ADS)

Boghani, Hitesh C.; Dinsdale, Richard M.; Guwy, Alan J.; Premier, Giuliano C.

2017-07-01

Research into microbial fuel cells (MFCs) has reached the point where cubic metre-scale systems and stacks are being built and tested. Apart from performance enhancement through catalysis, materials and design, an important research area for industrial applicability is stack control, which can enhance MFCs stack power output. An MFC stack is controlled using a sampled-time digital control strategy, which has the advantage of intermittent operation with consequent power saving, and when used in a hybrid series stack connectivity, can avoid voltage reversals. A MFC stack comprising four tubular MFCs was operated hydraulically in series. Each MFC was connected to an independent controller and the stack was connected electrically in series, creating a hybrid-series connectivity. The voltage of each MFC in the stack was controlled such that the overall series stack voltage generated was the algebraic sum (1.26 V) of the individual MFC voltages (0.32, 0.32, 0.32 and 0.3). The controllers were able to control the individual voltages to the point where 2.52 mA was drawn from the stack at a load of 499.9 Ω (delivering 3.18 mW). The controllers were able to reject the disturbances and perturbations caused by electrical loading, temperature and substrate concentration.

Remote control flare stack igniter for combustible gases

NASA Technical Reports Server (NTRS)

Ray, W. L.

1972-01-01

Device has been designed and developed for igniting nonrecoverable combustible gases and sustaining combustion of gases evolving from various gas vent stacks. Igniter is superior to existing systems because of simplicity of operation, low cost fabrication, installation, operational and maintainability features, and excellent reliability in all phases of required operations.

Industrial chimney monitoring - contemporary methods

NASA Astrophysics Data System (ADS)

Kaszowska, Olga; Gruchlik, Piotr; Mika, Wiesław

2018-04-01

The paper presents knowledge acquired during the monitoring of a flue-gas stack, performed as part of technical and scientific surveillance of mining activity and its impact on industrial objects. The chimney is located in an area impacted by mining activity since the 1970s, from a coal mine which is no longer in existence. In the period of 2013-16, this area was subject to mining carried out by a mining entrepreneur who currently holds a license to excavate hard coal. Periodic measurements of the deflection of the 113-meter chimney are performed using conventional geodetic methods. The GIG used 3 methods to observe the stack: landbased 3D laser scanning, continuous deflection monitoring with a laser sensor, and drone-based visual inspections. The drone offered the possibility to closely inspect the upper sections of the flue-gas stack, which are difficult to see from the ground level.

Tests of a High Temperature Sample Conditioner for the Waste Treatment Plant LV-S2, LV-S3, HV-S3A and HV-S3B Exhaust Systems

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

Flaherty, Julia E.; Glissmeyer, John A.

2015-03-18

Tests were performed to evaluate a sample conditioning unit for stack monitoring at Hanford Tank Waste Treatment and Immobilization Plant (WTP) exhaust stacks with elevated air temperatures. The LV-S2, LV-S3, HV-S3A and HV-S3B exhaust stacks are expected to have elevated air temperature and dew point. At these emission points, exhaust temperatures are too high to deliver the air sample directly to the required stack monitoring equipment. As a result, a sample conditioning system is considered to cool and dry the air prior to its delivery to the stack monitoring system. The method proposed for the sample conditioning is a dilutionmore » system that will introduce cooler, dry air to the air sample stream. This method of sample conditioning is meant to reduce the sample temperature while avoiding condensation of moisture in the sample stream. An additional constraint is that the ANSI/HPS N13.1-1999 standard states that at least 50% of the 10 μm aerodynamic diameter (AD) particles present in the stack free stream must be delivered to the sample collector. In other words, depositional loss of particles should be limited to 50% in the sampling, transport, and conditioning systems. Based on estimates of particle penetration through the LV-S3 sampling system, the diluter should perform with about 80% penetration or better to ensure that the total sampling system passes the 50% or greater penetration criterion.« less

User Driven Image Stacking for ODI Data and Beyond via a Highly Customizable Web Interface

NASA Astrophysics Data System (ADS)

Hayashi, S.; Gopu, A.; Young, M. D.; Kotulla, R.

2015-09-01

While some astronomical archives have begun serving standard calibrated data products, the process of producing stacked images remains a challenge left to the end-user. The benefits of astronomical image stacking are well established, and dither patterns are recommended for almost all observing targets. Some archives automatically produce stacks of limited scientific usefulness without any fine-grained user or operator configurability. In this paper, we present PPA Stack, a web based stacking framework within the ODI - Portal, Pipeline, and Archive system. PPA Stack offers a web user interface with built-in heuristics (based on pointing, filter, and other metadata information) to pre-sort images into a set of likely stacks while still allowing the user or operator complete control over the images and parameters for each of the stacks they wish to produce. The user interface, designed using AngularJS, provides multiple views of the input dataset and parameters, all of which are synchronized in real time. A backend consisting of a Python application optimized for ODI data, wrapped around the SWarp software, handles the execution of stacking workflow jobs on Indiana University's Big Red II supercomputer, and the subsequent ingestion of the combined images back into the PPA archive. PPA Stack is designed to enable seamless integration of other stacking applications in the future, so users can select the most appropriate option for their science.

PM2.5 monitoring system based on ZigBee wireless sensor network

NASA Astrophysics Data System (ADS)

Lin, Lukai; Li, Xiangshun; Gu, Weiying

2017-06-01

In the view of the haze problem, aiming at improving the deficiency of the traditional PM2.5 monitoring methods, such as the insufficient real-time monitoring, limited transmission distance, high cost and the difficulty to maintain, the atmosphere PM2.5 monitoring system based on ZigBee technology is designed. The system combines the advantages of ZigBee’s low cost, low power consumption, high reliability and GPRS/Internet’s capability of remote transmission of data. Furthermore, it adopts TI’s Z-Stack protocol stack, and selects CC2530 chip and TI’s MSP430 microcontroller as the core, which establishes the air pollution monitoring network that is helpful for the early prediction of major air pollution disasters.

Test of Hydrogen-Oxygen PEM Fuel Cell Stack at NASA Glenn Research Center

NASA Technical Reports Server (NTRS)

Bents, David J.; Scullin, Vincent J.; Chang, Bei-Jiann; Johnson, Donald W.; Garcia, Christopher P.; Jakupca, Ian J.

2003-01-01

This paper describes performance characterization tests of a 64 cell hydrogen oxygen PEM fuel cell stack at NASA Glenn Research Center in February 2003. The tests were part of NASA's ongoing effort to develop a regenerative fuel cell for aerospace energy storage applications. The purpose of the tests was to verify capability of this stack to operate within a regenerative fuel cell, and to compare performance with earlier test results recorded by the stack developer. Test results obtained include polarization performance of the stack at 50 and 100 psig system pressure, and a steady state endurance run at 100 psig. A maximum power output of 4.8 kWe was observed during polarization runs, and the stack sustained a steady power output of 4.0 kWe during the endurance run. The performance data obtained from these tests compare reasonably close to the stack developer's results although some additional spread between best to worst performing cell voltages was observed. Throughout the tests, the stack demonstrated the consistent performance and repeatable behavior required for regenerative fuel cell operation.

Engineering aspects and hardware verification of a volume producable solid oxide fuel cell stack design for diesel auxiliary power units

NASA Astrophysics Data System (ADS)

Stelter, Michael; Reinert, Andreas; Mai, Björn Erik; Kuznecov, Mihail

A solid oxide fuel cell (SOFC) stack module is presented that is designed for operation on diesel reformate in an auxiliary power unit (APU). The stack was designed using a top-down approach, based on a specification of an APU system that is installed on board of vehicles. The stack design is planar, modular and scalable with stamped sheet metal interconnectors. It features thin membrane electrode assemblies (MEAs), such as electrolyte supported cells (ESC) and operates at elevated temperatures around 800 °C. The stack has a low pressure drop in both the anode and the cathode to facilitate a simple system layout. An overview of the technical targets met so far is given. A stack power density of 0.2 kW l -1 has been demonstrated in a fully integrated, thermally self-sustaining APU prototype running with diesel and without an external water supply.

40 CFR 63.1352 - Additional test methods.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing Industry Monitoring and... bypass stacks at portland cement manufacturing facilities, for use in applicability determinations under... kiln/raw mills and associated bypass stacks at portland cement manufacturing facilities, for use in...

Pressurized Testing of Solid Oxide Electrolysis Stacks with Advanced Electrode-Supported Cells

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

J. E. O'Brien; X. Zhang; G. K. Housley

2012-06-01

A new facility has been developed at the Idaho National Laboratory for pressurized testing of solid oxide electrolysis stacks. Pressurized operation is envisioned for large-scale hydrogen production plants, yielding higher overall efficiencies when the hydrogen product is to be delivered at elevated pressure for tank storage or pipelines. Pressurized operation also supports higher mass flow rates of the process gases with smaller components. The test stand can accommodate cell dimensions up to 8.5 cm x 8.5 cm and stacks of up to 25 cells. The pressure boundary for these tests is a water-cooled spool-piece pressure vessel designed for operation upmore » to 5 MPa. The stack is internally manifolded and operates in cross-flow with an inverted-U flow pattern. Feed-throughs for gas inlets/outlets, power, and instrumentation are all located in the bottom flange. The entire spool piece, with the exception of the bottom flange, can be lifted to allow access to the internal furnace and test fixture. Lifting is accomplished with a motorized threaded drive mechanism attached to a rigid structural frame. Stack mechanical compression is accomplished using springs that are located inside of the pressure boundary, but outside of the hot zone. Initial stack heatup and performance characterization occurs at ambient pressure followed by lowering and sealing of the pressure vessel and subsequent pressurization. Pressure equalization between the anode and cathode sides of the cells and the stack surroundings is ensured by combining all of the process gases downstream of the stack. Steady pressure is maintained by means of a backpressure regulator and a digital pressure controller. A full description of the pressurized test apparatus is provided in this paper.« less

Solid Oxide Fuel Cell short stack performance testing - part B: Operation in carbon capture applications and degradation issues

NASA Astrophysics Data System (ADS)

Mastropasqua, L.; Campanari, S.; Brouwer, J.

2017-12-01

The need to experimentally understand the performance of Solid Oxide Fuel Cells (SOFC) stacks under Carbon Capture and Storage (CCS) mode operating conditions, hence with anode recirculation, has prompted this two-part study. The steady state performance of a 6-cell short stack of Y2O3 stabilised Zirconia (YSZ) with Ni/YSZ anodes and composite Sr-doped LaMnO3 (LSM)/YSZ cathodes is experimentally evaluated. In Part A, the electrical and environmental performance are assessed and the results are compared with the commercial full-scale micro-Combined Heat and Power system, which comprises the same cells. In Part B of this work, a specific set of stack operating conditions important to CCS applications is explored. The experimental inlet composition is changed in order to reproduce a simulated syngas in CCS mode operation for different fuel utilisation factors. Operation with the simulated anode recycle syngas leads to lower voltage when the anode recycle is lower, mainly due to higher internal reforming and polarisation losses. A clear voltage trend is observed when the amount of CO content in the inlet fuel is increased, signalling an improvement of the polarisation performance at constant current density and fixed inlet equivalent hydrogen content. Stack degradation is measured and results in line with manufacturer's data.

40 CFR 503.40 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SEWAGE SLUDGE STANDARDS FOR THE USE OR... sewage sludge incinerator stack is monitored continuously for carbon monoxide. (2) The monthly average concentration of carbon monoxide in the exit gas from a sewage sludge incinerator stack, corrected for zero...

Performance of an annular solid-oxide fuel cell micro-stack array operating in single-chamber conditions

NASA Astrophysics Data System (ADS)

Liu, Mingliang; Lü, Zhe; Wei, Bo; Huang, Xiqiang; Zhang, Yaohui; Su, Wenhui

An annular micro-stack array consisting of four fuel cells has been fabricated and operated successfully in single-chamber conditions using a nitrogen-diluted oxygen-methane mixture as the operating gas. The single cells consist of a state-of-the-art porous NiO/Y 2O 3-stabilized ZrO 2 (YSZ) anode support, a YSZ electrolyte membrane and a modified La 0.7Sr 0.3MnO 3 (LSM) cathode. The annular configuration of the array is favorable for utilizing the heating effect. The maximum power output of the annular stack decreases with increasingCH 4/O 2 ratio. Its performance increases with increasing CH 4 flow rate and decreases with increasing N 2 flow rate. The power output of the stack is ∼380 mW at CH 4/O 2 = 1 and an N 2 flow rate of 100 sccm and the average maximum power density of each cell is ∼190 mW cm -2. The average performance of each cell in the annular micro-stack array is higher than that of an additional single cell placed next to the stack.

Dynamics-based Nondestructive Structural Monitoring Teclrniques

DTIC Science & Technology

2012-05-21

plate made from AS4/8552-2 carbon epoxy prepregs . The layup sequence: was [(0/45/90/-45)S]2 as illustrated in Figure 3.37. Each layer had the...at Penn State. Hexcel AS4/8552 unidirectional carbon/epoxy prepregs were used in the fabrication as raw materials. The prepregs were cut in pieces...with different fiber orientations and 132 stacked together following different stacking sequences. The stacked prepregs then went into a vacuum

Dynamics-based Nondestructive Structural Monitoring Techniques

DTIC Science & Technology

2012-06-21

made from AS4/8552-2 carbon epoxy prepregs . The layup sequence: was [(0/45/90/-45)S]2 as illustrated in Figure 3.37. Each layer had the thickness of...using facilities available at Penn State. Hexcel AS4/8552 unidirectional carbon/epoxy prepregs were used in the fabrication as raw materials. The... prepregs were cut in pieces with different fiber orientations and 132 stacked together following different stacking sequences. The stacked prepregs

40 CFR 270.62 - Hazardous waste incinerator permits.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Stack gas monitoring and pollution control equipment. (H) Nozzle and burner design. (I) Construction.... (iii) A detailed description of sampling and monitoring procedures, including sampling and monitoring locations in the system, the equipment to be used, sampling and monitoring frequency, and planned analytical...

Cell module and fuel conditioner development

NASA Technical Reports Server (NTRS)

Feret, J. M.

1981-01-01

A phosphoric acid fuel cell (PAFC) stack design having a 10 kW power rating for operation at higher than atmospheric pressure based on the existing Mark II design configuration is described. Functional analysis, trade studies and thermodynamic cycle analysis for requirements definition and system operating parameter selection purposes were performed. Fuel cell materials and components, and performance testing and evaluation of the repeating electrode components were characterized. The state of the art manufacturing technology for all fuel cell components and the fabrication of short stacks of various sites were established. A 10 kW PAFC stack design for higher pressure operation utilizing the top down systems engineering aproach was developed.

40 CFR 60.713 - Compliance provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... operator of the affected coating operation shall perform a liquid-liquid VOC material balance over each and... emission control device (other than a fixed-bed carbon adsorption system with individual exhaust stacks for...) when a fixed-bed carbon adsorption system with individual exhaust stacks for each adsorber vessel is...

40 CFR 60.713 - Compliance provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... operator of the affected coating operation shall perform a liquid-liquid VOC material balance over each and... emission control device (other than a fixed-bed carbon adsorption system with individual exhaust stacks for...) when a fixed-bed carbon adsorption system with individual exhaust stacks for each adsorber vessel is...

40 CFR 60.713 - Compliance provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... operator of the affected coating operation shall perform a liquid-liquid VOC material balance over each and... emission control device (other than a fixed-bed carbon adsorption system with individual exhaust stacks for...) when a fixed-bed carbon adsorption system with individual exhaust stacks for each adsorber vessel is...

OPERATING PARAMETERS TO MINIMIZE EMISSIONS DURING ROTARY KILN EMERGENCY SAFETY VENT OPENINGS

EPA Science Inventory

Certain designs of hazardous waste incinerator systems include emergency safety vents (ESVs). ESVs (also called dump stacks, vent stacks, emergency by-pass stacks, thermal relief valves, and pressure relief valves) are regarded as true emergency devices. Their purpose is to vent ...

Improved LIDT values for dielectric dispersive compensating mirrors applying ternary composites

NASA Astrophysics Data System (ADS)

Willemsen, T.; Schlichting, S.; Gyamfi, M.; Jupé, M.; Ehlers, H.; Morgner, U.; Ristau, D.

2016-12-01

The present contribution is addressed to an improved method to fabricate dielectric dispersive compensating mirrors (CMs) with an increased laser induced damage threshold (LIDT) by the use of ternary composite layers. Taking advantage of a novel in-situ phase monitor system, it is possible to control the sensitive deposition process more precisely. The study is initiated by a design synthesis, to achieve optimum reflection and GDD values for a conventional high low stack (HL)n. Afterwards the field intensity is analyzed, and layers affected by highest electric field intensities are exchanged by ternary composites of TaxSiyOz. Both designs have similar target specifications whereby one design is using ternary composites and the other one is distinguished by a (HL)n. The first layers of the stack are switched applying in-situ optical broad band monitoring in conjunction with a forward re-optimization algorithm, which also manipulates the layers remaining for deposition at each switching event. To accomplish the demanded GDD-spectra, the last layers are controlled by a novel in-situ white light interferometer operating in the infrared spectral range. Finally the CMs are measured in a 10.000 on 1 procedure according to ISO 21254 applying pulses with a duration of 130 fs at a central wavelength of 775 nm to determine the laser induced damage threshold.

The use of Graphic User Interface for development of a user-friendly CRS-Stack software

NASA Astrophysics Data System (ADS)

Sule, Rachmat; Prayudhatama, Dythia; Perkasa, Muhammad D.; Hendriyana, Andri; Fatkhan; Sardjito; Adriansyah

2017-04-01

The development of a user-friendly Common Reflection Surface (CRS) Stack software that has been built by implementing Graphical User Interface (GUI) is described in this paper. The original CRS-Stack software developed by WIT Consortium is compiled in the unix/linux environment, which is not a user-friendly software, so that a user must write the commands and parameters manually in a script file. Due to this limitation, the CRS-Stack become a non popular method, although applying this method is actually a promising way in order to obtain better seismic sections, which have better reflector continuity and S/N ratio. After obtaining successful results that have been tested by using several seismic data belong to oil companies in Indonesia, it comes to an idea to develop a user-friendly software in our own laboratory. Graphical User Interface (GUI) is a type of user interface that allows people to interact with computer programs in a better way. Rather than typing commands and module parameters, GUI allows the users to use computer programs in much simple and easy. Thus, GUI can transform the text-based interface into graphical icons and visual indicators. The use of complicated seismic unix shell script can be avoided. The Java Swing GUI library is used to develop this CRS-Stack GUI. Every shell script that represents each seismic process is invoked from Java environment. Besides developing interactive GUI to perform CRS-Stack processing, this CRS-Stack GUI is design to help geophysicists to manage a project with complex seismic processing procedures. The CRS-Stack GUI software is composed by input directory, operators, and output directory, which are defined as a seismic data processing workflow. The CRS-Stack processing workflow involves four steps; i.e. automatic CMP stack, initial CRS-Stack, optimized CRS-Stack, and CRS-Stack Supergather. Those operations are visualized in an informative flowchart with self explanatory system to guide the user inputting the parameter values for each operation. The knowledge of CRS-Stack processing procedure is still preserved in the software, which is easy and efficient to be learned. The software will still be developed in the future. Any new innovative seismic processing workflow will also be added into this GUI software.

International challenge to predict the impact of radioxenon releases from medical isotope production on a comprehensive nuclear test ban treaty sampling station

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

Eslinger, Paul W.; Bowyer, Ted W.; Achim, Pascal

Abstract The International Monitoring System (IMS) is part of the verification regime for the Comprehensive Nuclear-Test-Ban-Treaty Organization (CTBTO). At entry-into-force, half of the 80 radionuclide stations will be able to measure concentrations of several radioactive xenon isotopes produced in nuclear explosions, and then the full network may be populated with xenon monitoring afterward (Bowyer et al., 2013). Fission-based production of 99Mo for medical purposes also releases radioxenon isotopes to the atmosphere (Saey, 2009). One of the ways to mitigate the effect of emissions from medical isotope production is the use of stack monitoring data, if it were available, so thatmore » the effect of radioactive xenon emissions could be subtracted from the effect from a presumed nuclear explosion, when detected at an IMS station location. To date, no studies have addressed the impacts the time resolution or data accuracy of stack monitoring data have on predicted concentrations at an IMS station location. Recently, participants from seven nations used atmospheric transport modeling to predict the time-history of 133Xe concentration measurements at an IMS station in Germany using stack monitoring data from a medical isotope production facility in Belgium. Participants received only stack monitoring data and used the atmospheric transport model and meteorological data of their choice. Some of the models predicted the highest measured concentrations quite well (a high composite statistical model comparison rank or a small mean square error with the measured values). The results suggest release data on a 15 min time spacing is best. The model comparison rank and ensemble analysis suggests that combining multiple models may provide more accurate predicted concentrations than any single model. Further research is needed to identify optimal methods for selecting ensemble members and those methods may depend on the specific transport problem. None of the submissions based only on the stack monitoring data predicted the small measured concentrations very well. The one submission that best predicted small concentrations also included releases from nuclear power plants. Modeling of sources by other nuclear facilities with smaller releases than medical isotope production facilities may be important in discriminating those releases from releases from a nuclear explosion.« less

Feasibility study of ultrasonic elliptical vibration-assisted reaming of carbon fiber reinforced plastics/titanium alloy stacks.

PubMed

Geng, Daxi; Zhang, Deyuan; Li, Zhe; Liu, Dapeng

2017-03-01

The production of high quality bolt holes, especially on the carbon fiber reinforced plastics/titanium alloy (CFRP/Ti) stacks, is essential to the manufacturing process in order to facilitate part assembly and improve the component mechanical integrity in aerospace industry. Reaming is widely used as a mandatory operation for bolt holes to meet the strict industry requirements. In this paper, the ultrasonic elliptical vibration-assisted reaming (UEVR) which is considered as a new method for finish machining of CFRP/Ti stacked holes is studied. The paper outlines an analysis of tool performance and hole quality in UEVR compared with that in conventional reaming (CR). Experimental results show that the quality of holes was significantly improved in UEVR. This is substantiated by monitoring cutting force, hole geometric precision and surface finish. The average thrust forces and torque in UEVR were decreased over 30% and 60% respectively. It is found that, during first 45 holes, better diameter tolerance (IT7 vs. IT8), smaller diameter difference of CFRP and Ti holes (around 3μm vs. 12μm), better geometrical errors were achieved in UEVR as compared to CR. As for surface finish, both of the average roughness and hole surface topography in UEVR were obviously improved. Copyright © 2016 Elsevier B.V. All rights reserved.

A new, simple and precise method for measuring cyclotron proton beam energies using the activity vs. depth profile of zinc-65 in a thick target of stacked copper foils.

PubMed

Asad, A H; Chan, S; Cryer, D; Burrage, J W; Siddiqui, S A; Price, R I

2015-11-01

The proton beam energy of an isochronous 18MeV cyclotron was determined using a novel version of the stacked copper-foils technique. This simple method used stacked foils of natural copper forming 'thick' targets to produce Zn radioisotopes by the well-documented (p,x) monitor-reactions. Primary beam energy was calculated using the (65)Zn activity vs. depth profile in the target, with the results obtained using (62)Zn and (63)Zn (as comparators) in close agreement. Results from separate measurements using foil thicknesses of 100, 75, 50 or 25µm to form the stacks also concurred closely. Energy was determined by iterative least-squares comparison of the normalized measured activity profile in a target-stack with the equivalent calculated normalized profile, using 'energy' as the regression variable. The technique exploits the uniqueness of the shape of the activity vs. depth profile of the monitor isotope in the target stack for a specified incident energy. The energy using (65)Zn activity profiles and 50-μm foils alone was 18.03±0.02 [SD] MeV (95%CI=17.98-18.08), and 18.06±0.12MeV (95%CI=18.02-18.10; NS) when combining results from all isotopes and foil thicknesses. When the beam energy was re-measured using (65)Zn and 50-μm foils only, following a major upgrade of the ion sources and nonmagnetic beam controls the results were 18.11±0.05MeV (95%CI=18.00-18.23; NS compared with 'before'). Since measurement of only one Zn monitor isotope is required to determine the normalized activity profile this indirect yet precise technique does not require a direct beam-current measurement or a gamma-spectroscopy efficiency calibrated with standard sources, though a characteristic photopeak must be identified. It has some advantages over published methods using the ratio of cross sections of monitor reactions, including the ability to determine energies across a broader range and without need for customized beam degraders. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development and Applications of a Stage Stacking Procedure

NASA Technical Reports Server (NTRS)

Kulkarni, Sameer; Celestina, Mark L.; Adamczyk, John J.

2012-01-01

The preliminary design of multistage axial compressors in gas turbine engines is typically accomplished with mean-line methods. These methods, which rely on empirical correlations, estimate compressor performance well near the design point, but may become less reliable off-design. For land-based applications of gas turbine engines, off-design performance estimates are becoming increasingly important, as turbine plant operators desire peaking or load-following capabilities and hot-day operability. The current work develops a one-dimensional stage stacking procedure, including a newly defined blockage term, which is used to estimate the off-design performance and operability range of a 13-stage axial compressor used in a power generating gas turbine engine. The new blockage term is defined to give mathematical closure on static pressure, and values of blockage are shown to collapse to curves as a function of stage inlet flow coefficient and corrected shaft speed. In addition to these blockage curves, the stage stacking procedure utilizes stage characteristics of ideal work coefficient and adiabatic efficiency. These curves are constructed using flow information extracted from computational fluid dynamics (CFD) simulations of groups of stages within the compressor. Performance estimates resulting from the stage stacking procedure are shown to match the results of CFD simulations of the entire compressor to within 1.6% in overall total pressure ratio and within 0.3 points in overall adiabatic efficiency. Utility of the stage stacking procedure is demonstrated by estimation of the minimum corrected speed which allows stable operation of the compressor. Further utility of the stage stacking procedure is demonstrated with a bleed sensitivity study, which estimates a bleed schedule to expand the compressors operating range.

Small stack performance of intermediate temperature-operating solid oxide fuel cells using stainless steel interconnects and anode-supported single cell

NASA Astrophysics Data System (ADS)

Bae, Joongmyeon; Lim, Sungkwang; Jee, Hyunjin; Kim, Jung Hyun; Yoo, Young-Sung; Lee, Taehee

We are developing 1 kW class solid oxide fuel cell (SOFC) system for residential power generation (RPG) application supported by Korean Government. Anode-supported single cells with thin electrolyte layer of YSZ (yttria-stabilized zirconia) or ScSZ (scandia-stabilized zirconia) for intermediate temperature operation (650-750 °C), respectively, were fabricated and small stacks were built and evaluated. The LSCF/ScSZ/Ni-YSZ single cell showed performance of 543 mW cm -2 at 650 °C and 1680 mW cm -2 at 750 °C. The voltage of 15-cell stack based on 5 cm × 5 cm single cell (LSM/YSZ/Ni-YSZ) at 150 mW was 12.5 V in hydrogen as fuel of 120 sccm per cell at 750 °C and decreased to about 10.9 V at 500 h operation time. A 5-cell stack based on the LSCF/YSZ/FL/Ni-YSZ showed the maximum power density of 30 W, 25 W and 20 W at 750 °C, 700 °C and 650 °C, respectively. LSCF/ScSZ/Ni-YSZ-based stack showed better performance than LSCF/YSZ/Ni-YSZ stack from the experiment temperature range. I- V characteristics by using hydrogen gas and reformate gas of methane as fuel were investigated at 750 °C in LSCF/ScSZ/FL/Ni-YSZ-based 5-cell stack.

LONG-TERM PERFORMANCE OF SOLID OXIDE STACKS WITH ELECTRODE-SUPPORTED CELLS OPERATING IN THE STEAM ELECTROLYSIS MODE

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

J. E. O'Brien; R. C. O'Brien; X. Zhang

2011-11-01

Performance characterization and durability testing have been completed on two five-cell high-temperature electrolysis stacks constructed with advanced cell and stack technologies. The solid oxide cells incorporate a negative-electrode-supported multi-layer design with nickel-zirconia cermet negative electrodes, thin-film yttria-stabilized zirconia electrolytes, and multi-layer lanthanum ferrite-based positive electrodes. The per-cell active area is 100 cm2. The stack is internally manifolded with compliant mica-glass seals. Treated metallic interconnects with integral flow channels separate the cells. Stack compression is accomplished by means of a custom spring-loaded test fixture. Initial stack performance characterization was determined through a series of DC potential sweeps in both fuel cellmore » and electrolysis modes of operation. Results of these sweeps indicated very good initial performance, with area-specific resistance values less than 0.5 ?.cm2. Long-term durability testing was performed with A test duration of 1000 hours. Overall performance degradation was less than 10% over the 1000-hour period. Final stack performance characterization was again determined by a series of DC potential sweeps at the same flow conditions as the initial sweeps in both electrolysis and fuel cell modes of operation. A final sweep in the fuel cell mode indicated a power density of 0.356 W/cm2, with average per-cell voltage of 0.71 V at a current of 50 A.« less

Study on component interface evolution of a solid oxide fuel cell stack after long term operation

NASA Astrophysics Data System (ADS)

Yang, Jiajun; Huang, Wei; Wang, Xiaochun; Li, Jun; Yan, Dong; Pu, Jian; Chi, Bo; Li, Jian

2018-05-01

A 5-cell solid oxide fuel cell (SOFC) stack with external manifold structure is assembled and underwent a durability test with an output of 250 W for nearly 4400 h when current density and operating temperature are 355 mA/cm2 and 750 °C. Cells used in the stack are anode-supported cells (ASC) with yttria-stabilized zirconia (YSZ) electrolytes, Ni/YSZ hydrogen electrodes, and YSZ based composite cathode. The dimension of the cell is 150 × 150 mm (active area: 130 × 130 mm). Ceramic-glass sealant is used in the stack to keep the gas tightness between cells, interconnects and manifolds. Pure hydrogen and dry air are used as fuel and oxidant respectively. The stack has a maximum output of 340 W at 562 mA/cm2 current density at 750 °C. The stack shows a degradation of 1.5% per 1000 h during the test with 2 thermal cycles to room temperature. After the test, the stack was dissembled and examined. The relationship between microstructure changes of interfaces and degradation in the stack are discussed. The microstructure evolution of interfaces between electrode, contact material and current collector are unveiled and their relationship with the degradation is discussed.

Operation of a solid oxide fuel cell on biodiesel with a partial oxidation reformer

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

Siefert, N, Shekhawat, D.; Gemmen, R.; Berry, D.

The National Energy Technology Laboratory’s Office of Research & Development (NETL/ORD) has successfully demonstrated the operation of a solid oxide fuel cell (SOFC) using reformed biodiesel. The biodiesel for the project was produced and characterized by West Virginia State University (WVSU). This project had two main aspects: 1) demonstrate a catalyst formulation on monolith for biodiesel fuel reforming; and 2) establish SOFC stack test stand capabilities. Both aspects have been completed successfully. For the first aspect, in–house patented catalyst specifications were developed, fabricated and tested. Parametric reforming studies of biofuels provided data on fuel composition, catalyst degradation, syngas composition, andmore » operating parameters required for successful reforming and integration with the SOFC test stand. For the second aspect, a stack test fixture (STF) for standardized testing, developed by Pacific Northwest National Laboratory (PNNL) and Lawrence Berkeley National Laboratory (LBNL) for the Solid Energy Conversion Alliance (SECA) Program, was engineered and constructed at NETL. To facilitate the demonstration of the STF, NETL employed H.C. Starck Ceramics GmbH & Co. (Germany) anode supported solid oxide cells. In addition, anode supported cells, SS441 end plates, and cell frames were transferred from PNNL to NETL. The stack assembly and conditioning procedures, including stack welding and sealing, contact paste application, binder burn-out, seal-setting, hot standby, and other stack assembly and conditioning methods were transferred to NETL. In the future, fuel cell stacks provided by SECA or other developers could be tested at the STF to validate SOFC performance on various fuels. The STF operated on hydrogen for over 1000 hrs before switching over to reformed biodiesel for 100 hrs of operation. Combining these first two aspects led to demonstrating the biodiesel syngas in the STF. A reformer was built and used to convert 0.5 ml/min of biodiesel into mostly hydrogen and carbon monoxide (syngas.) The syngas was fed to the STF and fuel cell stack. The results presented in this experimental report document one of the first times a SOFC has been operated on syngas from reformed biodiesel.« less

A high-performance aluminum-feed microfluidic fuel cell stack

NASA Astrophysics Data System (ADS)

Wang, Yifei; Leung, Dennis Y. C.

2016-12-01

In this paper, a six-cell microfluidic fuel cell (MFC) stack is demonstrated. Low-cost aluminum is fed directly to the stack, which produces hydrogen fuel on site, through the Al-H2O reaction. This design is not only cost-efficient, but also eliminates the need for hydrogen storage. Unlike the conventional MFC stacks which generally require complex electrolyte distribution and management, the present Al-feed MFC stack requires only a single electrolyte stream, flowing successively through individual cells, which is finally utilized for hydrogen generation. In this manner, the whole system is greatly simplified while the operational robustness is also improved. With 2 M sodium hydroxide solution as electrolyte and kitchen foil Al as fuel, the present six-cell stack (in series) exhibits an open circuit voltage of nearly 6 V and a peak power density of 180.6 mWcm-2 at room temperature. In addition, an energy density of 1 Whg-1(Al) is achieved, which is quite high and comparable with its proton exchange membrane-based counterparts. Finally, pumpless operation of the present stack, together with its practical applications are successfully demonstrated, including lightening LED lights, driving an electric fan, and cell phone charging.

40 CFR 63.307 - Standards for bypass/bleeder stacks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Standards for Coke Oven Batteries § 63.307 Standards for bypass/bleeder stacks. (a)(1) Except as otherwise... flow generated by the battery, which shall thereafter be operated and maintained. (2) Coke oven... operator of a brownfield coke oven battery or a padup rebuild shall install such a flare system before...

40 CFR 63.307 - Standards for bypass/bleeder stacks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Standards for Coke Oven Batteries § 63.307 Standards for bypass/bleeder stacks. (a)(1) Except as otherwise... flow generated by the battery, which shall thereafter be operated and maintained. (2) Coke oven... operator of a brownfield coke oven battery or a padup rebuild shall install such a flare system before...

Wavefront attributes in anisotropic media

NASA Astrophysics Data System (ADS)

Vanelle, C.; Abakumov, I.; Gajewski, D.

2018-07-01

Surface-measured wavefront attributes are the key ingredient to multiparameter methods, which are nowadays standard tools in seismic data processing. However, most operators are restricted to application to isotropic media. Whereas application of an isotropic operator will still lead to satisfactory stack results, further processing steps that interpret isotropic stacking parameters in terms of wavefront attributes will lead to erroneous results if anisotropy is present but not accounted for. In this paper, we derive relationships between the stacking parameters and anisotropic wavefront attributes that allow us to apply the common reflection surface type operator to 3-D media with arbitrary anisotropy for the zero-offset and finite-offset configurations including converted waves. The operator itself is expressed in terms of wavefront attributes that are measured in the acquisition surface, that is, no model assumptions are made. Numerical results confirm that the accuracy of the new anisotropic operator is of the same magnitude as that of its isotropic counterpart.

40 CFR 75.53 - Monitoring plan.

Code of Federal Regulations, 2012 CFR

2012-07-01

... are pre-combustion, post-combustion, or integral to the combustion process; control equipment code... fuel flow-to-load test in section 2.1.7 of appendix D to this part is used: (A) The upper and lower... and applied to the hourly flow rate data: (A) Stack or duct width at the test location, ft; (B) Stack...

Pollution Measuring System

NASA Technical Reports Server (NTRS)

1980-01-01

Research Ventures, Inc.'s visiplume is a portable, microprocessor-controlled air pollution monitor for measuring sulfur dioxide emissions from fossil fuel-fired power plants, and facilities that manufacture sulfuric acid. It observes smokestack plumes at a distance from the stack obviating the expense and difficulty of installing sample collectors in each stack and later analyzing the samples.

International challenge to predict the impact of radioxenon releases from medical isotope production on a comprehensive nuclear test ban treaty sampling station.

PubMed

Eslinger, Paul W; Bowyer, Ted W; Achim, Pascal; Chai, Tianfeng; Deconninck, Benoit; Freeman, Katie; Generoso, Sylvia; Hayes, Philip; Heidmann, Verena; Hoffman, Ian; Kijima, Yuichi; Krysta, Monika; Malo, Alain; Maurer, Christian; Ngan, Fantine; Robins, Peter; Ross, J Ole; Saunier, Olivier; Schlosser, Clemens; Schöppner, Michael; Schrom, Brian T; Seibert, Petra; Stein, Ariel F; Ungar, Kurt; Yi, Jing

2016-06-01

The International Monitoring System (IMS) is part of the verification regime for the Comprehensive Nuclear-Test-Ban-Treaty Organization (CTBTO). At entry-into-force, half of the 80 radionuclide stations will be able to measure concentrations of several radioactive xenon isotopes produced in nuclear explosions, and then the full network may be populated with xenon monitoring afterward. An understanding of natural and man-made radionuclide backgrounds can be used in accordance with the provisions of the treaty (such as event screening criteria in Annex 2 to the Protocol of the Treaty) for the effective implementation of the verification regime. Fission-based production of (99)Mo for medical purposes also generates nuisance radioxenon isotopes that are usually vented to the atmosphere. One of the ways to account for the effect emissions from medical isotope production has on radionuclide samples from the IMS is to use stack monitoring data, if they are available, and atmospheric transport modeling. Recently, individuals from seven nations participated in a challenge exercise that used atmospheric transport modeling to predict the time-history of (133)Xe concentration measurements at the IMS radionuclide station in Germany using stack monitoring data from a medical isotope production facility in Belgium. Participants received only stack monitoring data and used the atmospheric transport model and meteorological data of their choice. Some of the models predicted the highest measured concentrations quite well. A model comparison rank and ensemble analysis suggests that combining multiple models may provide more accurate predicted concentrations than any single model. None of the submissions based only on the stack monitoring data predicted the small measured concentrations very well. Modeling of sources by other nuclear facilities with smaller releases than medical isotope production facilities may be important in understanding how to discriminate those releases from releases from a nuclear explosion. Published by Elsevier Ltd.

Transient analysis of a solid oxide fuel cell stack with crossflow configuration

NASA Astrophysics Data System (ADS)

Yuan, P.; Liu, S. F.

2018-05-01

This study investigates the transient response of the cell temperature and current density of a solid oxide fuel cell having 6 stacks with crossflow configuration. A commercial software repeatedly solves the governing equations of each stack, and get the convergent results of the whole SOFC stack. The preliminary results indicate that the average current density of each stack is similar to others, so the power output between different stacks are uniform. Moreover, the average cell temperature among stacks is different, and the central stacks have higher temperature due to its harder heat dissipation. For the operating control, the cell temperature difference among stacks is worth to concern because the temperature difference will be over 10 °C in the analysis case. The increasing of the inlet flow rate of the fuel and air will short the transient state, increase the average current density, and drop the cell temperature difference among the stacks. Therefore, the inlet flow rate is an important factor for transient performance of a SOFC stack.

40 CFR 63.307 - Standards for bypass/bleeder stacks.

Code of Federal Regulations, 2014 CFR

2014-07-01

... National Emission Standards for Coke Oven Batteries § 63.307 Standards for bypass/bleeder stacks. (a)(1.... (2) Coke oven emissions shall not be vented to the atmosphere through bypass/bleeder stacks, except.... (3) The owner or operator of a brownfield coke oven battery or a padup rebuild shall install such a...

40 CFR 63.307 - Standards for bypass/bleeder stacks.

Code of Federal Regulations, 2013 CFR

2013-07-01

... National Emission Standards for Coke Oven Batteries § 63.307 Standards for bypass/bleeder stacks. (a)(1.... (2) Coke oven emissions shall not be vented to the atmosphere through bypass/bleeder stacks, except.... (3) The owner or operator of a brownfield coke oven battery or a padup rebuild shall install such a...

40 CFR 63.307 - Standards for bypass/bleeder stacks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... National Emission Standards for Coke Oven Batteries § 63.307 Standards for bypass/bleeder stacks. (a)(1.... (2) Coke oven emissions shall not be vented to the atmosphere through bypass/bleeder stacks, except.... (3) The owner or operator of a brownfield coke oven battery or a padup rebuild shall install such a...

Transient deformational properties of high temperature alloys used in solid oxide fuel cell stacks

NASA Astrophysics Data System (ADS)

Molla, Tesfaye Tadesse; Kwok, Kawai; Frandsen, Henrik Lund

2017-05-01

Stresses and probability of failure during operation of solid oxide fuel cells (SOFCs) is affected by the deformational properties of the different components of the SOFC stack. Though the overall stress relaxes with time during steady state operation, large stresses would normally appear through transients in operation including temporary shut downs. These stresses are highly affected by the transient creep behavior of metallic components in the SOFC stack. This study investigates whether a variation of the so-called Chaboche's unified power law together with isotropic hardening can represent the transient behavior of Crofer 22 APU, a typical iron-chromium alloy used in SOFC stacks. The material parameters for the model are determined by measurements involving relaxation and constant strain rate experiments. The constitutive law is implemented into commercial finite element software using a user-defined material model. This is used to validate the developed constitutive law to experiments with constant strain rate, cyclic and creep experiments. The predictions from the developed model are found to agree well with experimental data. It is therefore concluded that Chaboche's unified power law can be applied to describe the high temperature inelastic deformational behaviors of Crofer 22 APU used for metallic interconnects in SOFC stacks.

Monitoring iodine-129 in air and milk samples collected near the Hanford Site: an investigation of historical iodine monitoring data.

PubMed

Fritz, Brad G; Patton, Gregory W

2006-01-01

While other research has reported on the concentrations of (129)I in the environment surrounding active nuclear fuel reprocessing facilities, there is a shortage of information regarding how the concentrations change once facilities close. At the Hanford Site, the Plutonium-Uranium Extraction (PUREX) chemical separation plant was operating between 1983 and 1990, during which time (129)I concentrations in air and milk were measured. After the cessation of chemical processing, plant emissions decreased 2.5 orders of magnitude over an 8-year period. An evaluation of (129)I and (127)I concentration data in air and milk spanning the PUREX operation and post-closure period was conducted to compare the changes in environmental levels. Measured concentrations over the monitoring period were below the levels that could result in a potential annual human dose greater than 1 mSv. There was a measurable difference in the measured air concentrations of (129)I at different distances from the source, indicating a distinct Hanford fingerprint. Correlations between stack emissions of (129)I and concentrations in air and milk indicate that atmospheric emissions were the major source of (129)I measured in environmental samples. The measured concentrations during PUREX operations were similar to observations made around a fuel reprocessing plant in Germany. After the PUREX Plant stopped operating, (129)I concentration measurements made upwind of Hanford were similar to the results from Seville, Spain.

Critical flow rate of anode fuel exhaust in a PEM fuel cell system

NASA Astrophysics Data System (ADS)

Zhu, Wenhua H.; Payne, Robert U.; Tatarchuk, Bruce J.

A manual purge line was added into the exterior fuel exhaust stream of a Ballard PEM stack in a Nexa™ power module. With the addition of manual exhaust purge, high levels of inert gases were intentionally added to the anode feed without changing normal operational procedures. A new method of determining the critical minimum flow rate in the anode exhaust stream was given by an anode mass balance. This type of operation makes dual use of membranes in the MEAs as both gas purifiers and as solid electrolytes. The PEM stack was successfully operated with up to ca. 7% nitrogen or carbon dioxide in the absence of a palladium-based hydrogen separator at ca. 200 W power level. Nitrogen in the anode stream was concentrated from 7.5% to 91.6%. The system maintained a fuel efficiency of 99% at a manual purge rate of 2.22 ml s -1 and no auto purge. The fuel cell stack efficiency was 64% and the stack output efficiency was 75%. The overall system efficiency was 39%. After troublesome CO and H 2S poisons were removed, a hydrocarbon reformate containing high levels of CO 2 and H 2O was further used in the Nexa™ stack. The size and complexity of the fuel processing system may be reduced at a specified power level by using this operational method.

30 CFR 250.442 - What are the requirements for a subsea BOP stack?

Code of Federal Regulations, 2010 CFR

2010-07-01

... OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations...) When you drill with a subsea BOP stack, you must install the BOP system before drilling below surface casing. The District Manager may require you to install a subsea BOP system before drilling below the...

Cell module and fuel conditioner development

NASA Technical Reports Server (NTRS)

Feret, J. M.

1982-01-01

The efforts performed to develop a phosphoric acid fuel cell (PAFC) stack design having a 10 kW power rating for operation at higher than atmospheric pressure based on the existing Mark II design configuration are described. The work involves: (1) Performance of pertinent functional analysis, trade studies and thermodynamic cycle analysis for requirements definition and system operating parameter selection purposes, (2) characterization of fuel cell materials and components, and performance testing and evaluation of the repeating electrode components, (3) establishment of the state-of-the-art manufacturing technology for all fuel cell components at Westinghouse and the fabrication of short stacks of various sites, and (4) development of a 10 kW PAFC stack design for higher pressure operation utilizing the top down systems engineering approach.

Optimization of properties and operating parameters of a passive DMFC mini-stack at ambient temperature

NASA Astrophysics Data System (ADS)

Baglio, V.; Stassi, A.; Matera, F. V.; Di Blasi, A.; Antonucci, V.; Aricò, A. S.

An investigation of properties and operating parameters of a passive DMFC monopolar mini-stack, such as catalyst loading and methanol concentration, was carried out. From this analysis, it was derived that a proper Pt loading is necessary to achieve the best compromise between electrode thickness and number of catalytic sites for the anode and cathode reactions to occur at suitable rates. Methanol concentrations ranging from 1 M up to 10 M and an air-breathing operation mode were investigated. A maximum power of 225 mW was obtained at ambient conditions for a three-cell stack, with an active single cell area of 4 cm 2, corresponding to a power density of about 20 mW cm -2.

Co-flow planar SOFC fuel cell stack

DOEpatents

Chung, Brandon W.; Pham, Ai Quoc; Glass, Robert S.

2004-11-30

A co-flow planar solid oxide fuel cell stack with an integral, internal manifold and a casing/holder to separately seal the cell. This construction improves sealing and gas flow, and provides for easy manifolding of cell stacks. In addition, the stack construction has the potential for an improved durability and operation with an additional increase in cell efficiency. The co-flow arrangement can be effectively utilized in other electrochemical systems requiring gas-proof separation of gases.

Phosphoric acid electric utility fuel cell technology development

NASA Astrophysics Data System (ADS)

Breault, R. D.; Briggs, T. A.; Congdon, J. V.; Demarche, T. E.; Gelting, R. L.; Goller, G. J.; Luoma, W. L.; McCloskey, M. W.; Mientek, A. P.; Obrien, J. J.

1991-04-01

The major objective of this effort was the advancement of cell and stack technology required to meet performance and cost criteria for fabrication and operation of a prototype large area, full height phosphoric acid fuel cell stack. The performance goal for the cell stack corresponded to a power density of 150 wsf, and the manufactured cost goal was a 510 $/kW reduction (in 1981 dollars) compared to existing 3.7 ft.(exp 2) active area cell stacks.

Recent Upgrades at the Safety and Tritium Applied Research Facility

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

Cadwallader, Lee Charles; Merrill, Brad Johnson; Stewart, Dean Andrew

This paper gives a brief overview of the Safety and Tritium Applied Research (STAR) facility operated by the Fusion Safety Program (FSP) at the Idaho National Laboratory (INL). FSP researchers use the STAR facility to carry out experiments in tritium permeation and retention in various fusion materials, including wall armor tile materials. FSP researchers also perform other experimentation as well to support safety assessment in fusion development. This lab, in its present two-building configuration, has been in operation for over ten years. The main experiments at STAR are briefly described. This paper discusses recent work to enhance personnel safety atmore » the facility. The STAR facility is a Department of Energy less than hazard category 3 facility; the personnel safety approach calls for ventilation and tritium monitoring for radiation protection. The tritium areas of STAR have about 4 to 12 air changes per hour, with air flow being once through and then routed to the facility vent stack. Additional radiation monitoring has been installed to read the laboratory room air where experiments with tritium are conducted. These ion chambers and bubblers are used to verify that no significant tritium concentrations are present in the experiment rooms. Standby electrical power has been added to the facility exhaust blower so that proper ventilation will now operate during commercial power outages as well as the real-time tritium air monitors.« less

Fuel cell CO sensor

DOEpatents

Grot, Stephen Andreas; Meltser, Mark Alexander; Gutowski, Stanley; Neutzler, Jay Kevin; Borup, Rodney Lynn; Weisbrod, Kirk

1999-12-14

The CO concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and/or voltage behavior patterns from a PEM-probe communicating with the reformate feed stream. Pattern recognition software may be used to compare the current and voltage patterns from the PEM-probe to current and voltage telltale outputs determined from a reference cell similar to the PEM-probe and operated under controlled conditions over a wide range of CO concentrations in the H.sub.2 fuel stream. A CO sensor includes the PEM-probe, an electrical discharge circuit for discharging the PEM-probe to monitor the CO concentration, and an electrical purging circuit to intermittently raise the anode potential of the PEM-probe's anode to at least about 0.8 V (RHE) to electrochemically oxidize any CO adsorbed on the probe's anode catalyst.

Method of monitoring CO concentrations in hydrogen feed to a PEM fuel cell

DOEpatents

Grot, Stephen Andreas; Meltser, Mark Alexander; Gutowski, Stanley; Neutzler, Jay Kevin; Borup, Rodney Lynn; Weisbrod, Kirk

2000-01-01

The CO concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and/or voltage behavior patterns from a PEM-probe communicating with the reformate feed stream. Pattern recognition software may be used to compare the current and voltage patterns from the PEM-probe to current and voltage telltale outputs determined from a reference cell similar to the PEM-probe and operated under controlled conditions over a wide range of CO concentrations in the H.sub.2 fuel stream. The PEM-probe is intermittently purged of any CO build-up on the anode catalyst (e.g., by (1) flushing the anode with air, (2) short circuiting the PEM-probe, or (3) reverse biasing the PEM-probe) to keep the PEM-probe at peak performance levels.

A prototype of an automated high resolution InSAR volcano-monitoring system in the MED-SUV project

NASA Astrophysics Data System (ADS)

Chowdhury, Tanvir A.; Minet, Christian; Fritz, Thomas

2016-04-01

Volcanic processes which produce a variety of geological and hydrological hazards are difficult to predict and capable of triggering natural disasters on regional to global scales. Therefore it is important to monitor volcano continuously and with a high spatial and temporal sampling rate. The monitoring of active volcanoes requires the reliable measurement of surface deformation before, during and after volcanic activities and it helps for the better understanding and modelling of the involved geophysical processes. Space-borne synthetic aperture radar (SAR) interferometry (InSAR), persistent scatterer interferometry (PSI) and small baseline subset algorithm (SBAS) provide a powerful tool for observing the eruptive activities and measuring the surface changes of millimetre accuracy. All the mentioned techniques with deformation time series extraction address the challenges by exploiting medium to large SAR image stacks. The process of selecting, ordering, downloading, storing, logging, extracting and preparing the data for processing is very time consuming has to be done manually for every single data-stack. In many cases it is even an iterative process which has to be done regularly and continuously. Therefore, data processing becomes slow which causes significant delays in data delivery. The SAR Satellite based High Resolution Data Acquisition System, which will be developed at DLR, will automate this entire time consuming tasks and allows an operational volcano monitoring system. Every 24 hours the system runs for searching new acquired scene over the volcanoes and keeps track of the data orders, log the status and download the provided data via ftp-transfer including E-Mail alert. Furthermore, the system will deliver specified reports and maps to a database for review and use by specialists. The user interaction will be minimized and iterative processes will be totally avoided. In this presentation, a prototype of SAR Satellite based High Resolution Data Acquisition System, which is developed and operated by DLR, will be described in detail. The workflow of the developed system is described which allow a meaningful contribution of SAR for monitoring volcanic eruptive activities. A more robust and efficient InSAR data processing in IWAP processor will be introduced in the framework of a remote sensing task of MED-SUV project. An application of the developed prototype system to a historic eruption of Mount Etna and Piton de la Fournaise will be depicted in the last part of the presentation.

Performance Analysis of Air Breathing Proton Exchange Membrane Fuel Cell Stack (PEMFCS) At Different Operating Condition

NASA Astrophysics Data System (ADS)

Sunil, V.; Venkata siva, G.; Yoganjaneyulu, G.; Ravikumar, V. V.

2017-08-01

The answer for an emission free power source in future is in the form of fuel cells which combine hydrogen and oxygen producing electricity and a harmless by product-water. A proton exchange membrane (PEM) fuel cell is ideal for automotive applications. A single cell cannot supply the essential power for any application. Hence PEM fuel cell stacks are used. The effect of different operating parameters namely: type of convection, type of draught, hydrogen flow rate, hydrogen inlet pressure, ambient temperature and humidity, hydrogen humidity, cell orientation on the performance of air breathing PEM fuel cell stack was analyzed using a computerized fuel cell test station. Then, the fuel cell stack was subjected to different load conditions. It was found that the stack performs very poorly at full capacity (runs only for 30 min. but runs for 3 hours at 50% capacity). Hence, a detailed study was undertaken to maximize the duration of the stack’s performance at peak load.

On gate stack scalability of double-gate negative-capacitance FET with ferroelectric HfO2 for energy efficient sub-0.2 V operation

NASA Astrophysics Data System (ADS)

Jang, Kyungmin; Saraya, Takuya; Kobayashi, Masaharu; Hiramoto, Toshiro

2018-02-01

We have investigated the gate stack scalability and energy efficiency of double-gate negative-capacitance FET (DGNCFET) with a CMOS-compatible ferroelectric HfO2 (FE:HfO2). Analytic model-based simulation is conducted to investigate the impacts of ferroelectric characteristic of FE:HfO2 and gate stack thickness on the I on/I off ratio of DGNCFET. DGNCFET has wider design window for the gate stack where higher I on/I off ratio can be achieved than DG classical MOSFET. Under a process-induced constraint with sub-10 nm gate length (L g), FE:HfO2-based DGNCFET still has a design point for high I on/I off ratio. With an optimized gate stack thickness for sub-10 nm L g, FE:HfO2-based DGNCFET has 2.5× higher energy efficiency than DG classical MOSFET even at ultralow operation voltage of sub-0.2 V.

First field demonstration of cloud datacenter workflow automation employing dynamic optical transport network resources under OpenStack and OpenFlow orchestration.

PubMed

Szyrkowiec, Thomas; Autenrieth, Achim; Gunning, Paul; Wright, Paul; Lord, Andrew; Elbers, Jörg-Peter; Lumb, Alan

2014-02-10

For the first time, we demonstrate the orchestration of elastic datacenter and inter-datacenter transport network resources using a combination of OpenStack and OpenFlow. Programmatic control allows a datacenter operator to dynamically request optical lightpaths from a transport network operator to accommodate rapid changes of inter-datacenter workflows.

30 CFR 250.441 - What are the requirements for a surface BOP stack?

Code of Federal Regulations, 2010 CFR

2010-07-01

... OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations...? (a) When you drill with a surface BOP stack, you must install the BOP system before drilling below... with blind-shear rams. The blind-shear rams must be capable of shearing the drill pipe that is in the...

30 CFR 250.416 - What must I include in the diverter and BOP descriptions?

Code of Federal Regulations, 2010 CFR

2010-07-01

... OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Applying for A Permit to Drill § 250.416 What must I include in the diverter and BOP descriptions? You must... rams installed in the BOP stack (both surface and subsea stacks) are capable of shearing the drill pipe...

Operation of Thin-Film Electrolyte Metal-Supported Solid Oxide Fuel Cells in Lightweight and Stationary Stacks: Material and Microstructural Aspects

PubMed Central

Roehrens, Daniel; Packbier, Ute; Fang, Qingping; Blum, Ludger; Sebold, Doris; Bram, Martin; Menzler, Norbert

2016-01-01

In this study we report on the development and operational data of a metal-supported solid oxide fuel cell with a thin film electrolyte under varying conditions. The metal-ceramic structure was developed for a mobile auxiliary power unit and offers power densities of 1 W/cm2 at 800 °C, as well as robustness under mechanical, thermal and chemical stresses. A dense and thin yttria-doped zirconia layer was applied to a nanoporous nickel/zirconia anode using a scalable adapted gas-flow sputter process, which allowed the homogeneous coating of areas up to 100 cm2. The cell performance is presented for single cells and for stack operation, both in lightweight and stationary stack designs. The results from short-term operation indicate that this cell technology may be a very suitable alternative for mobile applications. PMID:28773883

40 CFR 75.53 - Monitoring plan.

Code of Federal Regulations, 2010 CFR

2010-07-01

... this part. (c)-(d) [Reserved] (e) Contents of the monitoring plan. Each monitoring plan shall contain..., rounded to the nearest 100 lb/hr); (J) Identification of all units using a common stack; (K) Activation...: (A) Program(s) for which the EDR is submitted; (B) Unit classification; (C) Reporting frequency; (D...

40 CFR 75.53 - Monitoring plan.

Code of Federal Regulations, 2011 CFR

2011-07-01

... this part. (c)-(d) [Reserved] (e) Contents of the monitoring plan. Each monitoring plan shall contain..., rounded to the nearest 100 lb/hr); (J) Identification of all units using a common stack; (K) Activation...: (A) Program(s) for which the EDR is submitted; (B) Unit classification; (C) Reporting frequency; (D...

Fuel cell power supply with oxidant and fuel gas switching

DOEpatents

McElroy, James F.; Chludzinski, Paul J.; Dantowitz, Philip

1987-01-01

This invention relates to a fuel cell vehicular power plant. Fuel for the fuel stack is supplied by a hydrocarbon (methanol) catalytic cracking reactor and CO shift reactor. A water electrolysis subsystem is associated with the stack. During low power operation part of the fuel cell power is used to electrolyze water with hydrogen and oxygen electrolysis products being stored in pressure vessels. During peak power intervals, viz, during acceleration or start-up, pure oxygen and pure hydrogen from the pressure vessel are supplied as the reaction gases to the cathodes and anodes in place of air and methanol reformate. This allows the fuel cell stack to be sized for normal low power/air operation but with a peak power capacity several times greater than that for normal operation.

Fuel cell power supply with oxidant and fuel gas switching

DOEpatents

McElroy, J.F.; Chludzinski, P.J.; Dantowitz, P.

1987-04-14

This invention relates to a fuel cell vehicular power plant. Fuel for the fuel stack is supplied by a hydrocarbon (methanol) catalytic cracking reactor and CO shift reactor. A water electrolysis subsystem is associated with the stack. During low power operation part of the fuel cell power is used to electrolyze water with hydrogen and oxygen electrolysis products being stored in pressure vessels. During peak power intervals, viz, during acceleration or start-up, pure oxygen and pure hydrogen from the pressure vessel are supplied as the reaction gases to the cathodes and anodes in place of air and methanol reformate. This allows the fuel cell stack to be sized for normal low power/air operation but with a peak power capacity several times greater than that for normal operation. 2 figs.

Assessment of opacimeter calibration according to International Standard Organization 10155.

PubMed

Gomes, J F

2001-01-01

This paper compares the calibration method for opacimeters issued by the International Standard Organization (ISO) 10155 with the manual reference method for determination of dust content in stack gases. ISO 10155 requires at least nine operational measurements, corresponding to three operational measurements per each dust emission range within the stack. The procedure is assessed by comparison with previous calibration methods for opacimeters using only two operational measurements from a set of measurements made at stacks from pulp mills. The results show that even if the international standard for opacimeter calibration requires that the calibration curve is to be obtained using 3 x 3 points, a calibration curve derived using 3 points could be, at times, acceptable in statistical terms, provided that the amplitude of individual measurements is low.

Novel electrical energy storage system based on reversible solid oxide cells: System design and operating conditions

NASA Astrophysics Data System (ADS)

Wendel, C. H.; Kazempoor, P.; Braun, R. J.

2015-02-01

Electrical energy storage (EES) is an important component of the future electric grid. Given that no other widely available technology meets all the EES requirements, reversible (or regenerative) solid oxide cells (ReSOCs) working in both fuel cell (power producing) and electrolysis (fuel producing) modes are envisioned as a technology capable of providing highly efficient and cost-effective EES. However, there are still many challenges and questions from cell materials development to system level operation of ReSOCs that should be addressed before widespread application. This paper presents a novel system based on ReSOCs that employ a thermal management strategy of promoting exothermic methanation within the ReSOC cell-stack to provide thermal energy for the endothermic steam/CO2 electrolysis reactions during charging mode (fuel producing). This approach also serves to enhance the energy density of the stored gases. Modeling and parametric analysis of an energy storage concept is performed using a physically based ReSOC stack model coupled with thermodynamic system component models. Results indicate that roundtrip efficiencies greater than 70% can be achieved at intermediate stack temperature (680 °C) and elevated stack pressure (20 bar). The optimal operating condition arises from a tradeoff between stack efficiency and auxiliary power requirements from balance of plant hardware.

Fuel cell system with sodium borohydride as hydrogen source for unmanned aerial vehicles

NASA Astrophysics Data System (ADS)

Kim, Kyunghwan; Kim, Taegyu; Lee, Kiseong; Kwon, Sejin

In this study, we design and fabricate a fuel cell system for application as a power source in unmanned aerial vehicles (UAVs). The fuel cell system consists of a fuel cell stack, hydrogen generator, and hybrid power management system. PEMFC stack with an output power of 100 W is prepared and tested to decide the efficient operating conditions; the stack must be operated in the dead-end mode with purge in order to ensure prolonged stack performance. A hydrogen generator is fabricated to supply gaseous hydrogen to the stack. Sodium borohydride (NaBH 4) is used as the hydrogen source in the present study. Co/Al 2O 3 catalyst is prepared for the hydrolysis of the alkaline NaBH 4 solution at room temperature. The fabricated Co catalyst is comparable to the Ru catalyst. The UAV consumes more power in the takeoff mode than in the cruising mode. A hybrid power management system using an auxiliary battery is developed and evaluated for efficient energy management. Hybrid power from both the fuel cell and battery powers takeoff and turning flight operations, while the fuel cell supplies steady power during the cruising flight. The capabilities of the fuel-cell UAVs for long endurance flights are validated by successful flight tests.

RECENT ADVANCES IN HIGH TEMPERATURE ELECTROLYSIS AT IDAHO NATIONAL LABORATORY: STACK TESTS

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

X, Zhang; J. E. O'Brien; R. C. O'Brien

2012-07-01

High temperature steam electrolysis is a promising technology for efficient sustainable large-scale hydrogen production. Solid oxide electrolysis cells (SOECs) are able to utilize high temperature heat and electric power from advanced high-temperature nuclear reactors or renewable sources to generate carbon-free hydrogen at large scale. However, long term durability of SOECs needs to be improved significantly before commercialization of this technology. A degradation rate of 1%/khr or lower is proposed as a threshold value for commercialization of this technology. Solid oxide electrolysis stack tests have been conducted at Idaho National Laboratory to demonstrate recent improvements in long-term durability of SOECs. Electrolytesupportedmore » and electrode-supported SOEC stacks were provided by Ceramatec Inc., Materials and Systems Research Inc. (MSRI), and Saint Gobain Advanced Materials (St. Gobain), respectively for these tests. Long-term durability tests were generally operated for a duration of 1000 hours or more. Stack tests based on technology developed at Ceramatec and MSRI have shown significant improvement in durability in the electrolysis mode. Long-term degradation rates of 3.2%/khr and 4.6%/khr were observed for MSRI and Ceramatec stacks, respectively. One recent Ceramatec stack even showed negative degradation (performance improvement) over 1900 hours of operation. A three-cell short stack provided by St. Gobain, however, showed rapid degradation in the electrolysis mode. Improvements on electrode materials, interconnect coatings, and electrolyteelectrode interface microstructures contribute to better durability of SOEC stacks.« less

A new slip stacking RF system for a twofold power upgrade of Fermilab's Accelerator Complex

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

Madrak, Robyn

2014-05-15

Fermilab's Accelerator Complex has been recently upgraded, in order to increase the 120 GeV proton beam power on target from about 400 kW to over 700 kW for NOvA and other future intensity frontier experiments. One of the key ingredients of the upgrade is the offloading of some Main Injector synchrotron operations - beam injection and RF manipulation called ''slip stacking'' - to the 8GeV Recycler Ring, which had until recently been used only for low-intensity antiproton storage and cooling. This required construction of two new 53 MHz RF systems for the slip-stacking manipulations. The cavities operate simultaneously at Vmore » peak ≲150 kV, but at slightly different frequencies (Δf=1260 Hz). Their installation was completed in September 2013. This article describes the novel solutions used in the design of the new cavities, their tuning system, and the associated high power RF system. First results showing effective operation of the RF system, beam capture and successful slip-stacking in the Recycler Ring are presented.« less

LHCb experience with running jobs in virtual machines

NASA Astrophysics Data System (ADS)

McNab, A.; Stagni, F.; Luzzi, C.

2015-12-01

The LHCb experiment has been running production jobs in virtual machines since 2013 as part of its DIRAC-based infrastructure. We describe the architecture of these virtual machines and the steps taken to replicate the WLCG worker node environment expected by user and production jobs. This relies on the uCernVM system for providing root images for virtual machines. We use the CernVM-FS distributed filesystem to supply the root partition files, the LHCb software stack, and the bootstrapping scripts necessary to configure the virtual machines for us. Using this approach, we have been able to minimise the amount of contextualisation which must be provided by the virtual machine managers. We explain the process by which the virtual machine is able to receive payload jobs submitted to DIRAC by users and production managers, and how this differs from payloads executed within conventional DIRAC pilot jobs on batch queue based sites. We describe our operational experiences in running production on VM based sites managed using Vcycle/OpenStack, Vac, and HTCondor Vacuum. Finally we show how our use of these resources is monitored using Ganglia and DIRAC.

Geometry effects on cooling in a standing wave cylindrical thermoacousic resonator

NASA Astrophysics Data System (ADS)

Mohd-Ghazali, Normah; Ghazali, Ahmad Dairobi; Ali, Irwan Shah; Rahman, Muhammad Aminullah A.

2012-06-01

Numerous reports have established the refrigeration applications of thermoacoustic cooling without compressors and refrigerants. Significant cooling effects can be obtained in a thermoacoustic resonator fitted with a heat exchanging stack and operated at resonance frequency. Past studies, however, have hardly referred to the fundamental relationship between resonant frequency and the resonator geometry. This paper reports the thermoacoustic cooling effects at resonance obtained by changing the diameter of the resonator while holding the length constant and vice versa. Experiments were completed at atmospheric pressure with air as the working fluid using a number of pvc tubes having parallel plate stack from Mylar. The temperature difference measured across the stack showed that a volume increase in the working fluid in general increases the temperature gradient for the quarter-and half-wavelength resonators. Doubling the diameter from 30 mm to 60 mm produced the highest temperature difference due to the greater number of stack plates resulting in a higher overall thermoacaoustic cooling. Increasing the resonator length only produced a small increase in temperature gradient since the resonant frequency at operation is only slightly changed. Investigation on the aspect ratio exhibits no influence on the temperature difference across the stack. This study have shown that the resonator length and diameter do affect the temperature difference across the thermoacoustic stack, and further research should be done to consider the contribution of the stack mass on the overall desired thermoacoustic cooling.

Improved Durability of SOEC Stacks for High Temperature Electrolysis

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

James E. O'Brien; Robert C. O'Brien; Xiaoyu Zhang

2013-01-01

High temperature steam electrolysis is a promising technology for efficient and sustainable large-scale hydrogen production. Solid oxide electrolysis cells (SOECs) are able to utilize high temperature heat and electric power from advanced high-temperature nuclear reactors or renewable sources to generate carbon-free hydrogen at large scale. However, long term durability of SOECs needs to be improved significantly before commercialization of this technology can be realized. A degradation rate of 1%/khr or lower is proposed as a threshold value for commercialization of this technology. Solid oxide electrolysis stack tests have been conducted at Idaho National Laboratory to demonstrate recent improvements in long-termmore » durability of SOECs. Electrolyte-supported and electrode-supported SOEC stacks were provided by Ceramatec Inc. and Materials and Systems Research Inc. (MSRI), respectively, for these tests. Long-term durability tests were generally operated for a duration of 1000 hours or more. Stack tests based on technologies developed at Ceramatec and MSRI have shown significant improvement in durability in the electrolysis mode. Long-term degradation rates of 3.2%/khr and 4.6%/khr were observed for MSRI and Ceramatec stacks, espectively. One recent Ceramatec stack even showed negative degradation (performance improvement) over 1900 hours of operation. Optimization of electrode materials, interconnect coatings, and electrolyte-electrode interface microstructures contribute to better durability of SOEC stacks.« less

SIMULATIONS OF TRANSVERSE STACKING IN THE NSLS-II BOOSTER

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

Fliller III, R.; Shaftan, T.

2011-03-28

The NSLS-II injection system consists of a 200 MeV linac and a 3 GeV booster. The linac needs to deliver 15 nC in 80 - 150 bunches to the booster every minute to achieve current stability goals in the storage ring. This is a very stringent requirement that has not been demonstrated at an operating light source. We have developed a scheme to transversely stack two bunch trains in the NSLS-II booster in order to alleviate the charge requirements on the linac. This scheme has been outlined previously. In this paper we show particle tracking simulations of the tracking scheme.more » We show simulations of the booster ramp with a stacked beam for a variety of lattice errors and injected beam parameters. In all cases the performance of the proposed stacking method is sufficient to reduce the required charge from the linac. For this reason the injection system of the NSLS-II booster is being designed to include this feature. The NSLS-II injection system consists of a 200 MeV linac and a 3 GeV booster. The injectors must provide 7.5nC in bunch trains 80-150 bunches long every minute for top off operation of the storage ring. Top off then requires that the linac deliver 15nC of charge once losses in the injector chain are taken into consideration. This is a very stringent requirement that has not been demonstrated at an operating light source. For this reason we have developed a method to transversely stack two bunch trains in the booster while maintaining the charge transport efficiency. This stacking scheme has been discussed previously. In this paper we show the simulations of the booster ramp with a single bunch train in the booster. Then we give a brief overview of the stacking scheme. Following, we show the results of stacking two bunch trains in the booster with varying beam emittances and train separations. The behavior of the beam through the ramp is examined showing that it is possible to stack two bunch trains in the booster.« less

Ablation of film stacks in solar cell fabrication processes

DOEpatents

Harley, Gabriel; Kim, Taeseok; Cousins, Peter John

2013-04-02

A dielectric film stack of a solar cell is ablated using a laser. The dielectric film stack includes a layer that is absorptive in a wavelength of operation of the laser source. The laser source, which fires laser pulses at a pulse repetition rate, is configured to ablate the film stack to expose an underlying layer of material. The laser source may be configured to fire a burst of two laser pulses or a single temporally asymmetric laser pulse within a single pulse repetition to achieve complete ablation in a single step.

Elimination of voltage reversal in multiple membrane electrode assembly installed microbial fuel cells (mMEA-MFCs) stacking system by resistor control.

PubMed

Kim, Bongkyu; Chang, In Seop

2018-08-01

Voltage reversal (VR) in series connection of multiple membrane electrode assembly installed microbial fuel cells (mMEA-MFC) is eliminated by manipulating the resistor control. Discharge test results collected from two mMEA-MFCs initially operated (designated as P1 and P2) confirm that the performance of P2 exceeds that of P1. Thus, driving P1 and P2 as serially stacked MFCs generate the VR in P1. Controlling the inserted resistor adjust the current production of P2 to maintain balance with P1, and the VR in P1 is eliminated in the operation of stacking mode. Thus, manipulating the internal resistance provide an applicable approach to suppress VR in the stacking of mMEA-MFCs system. Copyright © 2018 Elsevier Ltd. All rights reserved.

Polymer electrolyte fuel cell mini power unit for portable application

NASA Astrophysics Data System (ADS)

Urbani, F.; Squadrito, G.; Barbera, O.; Giacoppo, G.; Passalacqua, E.; Zerbinati, O.

This paper describes the design, realisation and test of a power unit based on a polymer electrolyte fuel cell, operating at room temperature, for portable application. The device is composed of an home made air breathing fuel cell stack, a metal hydride tank for H 2 supply, a dc-dc converter for power output control and a fan for stack cooling. The stack is composed by 10 cells with an active surface of 25 cm 2 and produces a rated power of 15 W at 6 V and 2 A. The stack successfully runs with end-off fed hydrogen without appreciable performance degradation during the time. The final assembled system is able to generate 12 W at 9.5 V, and power a portable DVD player for 3 h in continuous. The power unit has collected about 100 h of operation without maintenance.

Electrically Conductive and Protective Coating for Planar SOFC Stacks

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

Choi, Jung-Pyung; Stevenson, Jeffry W.

Ferritic stainless steels are preferred interconnect materials for intermediate temperature SOFCs because of their resistance to oxidation, high formability and low cost. However, their protective oxide layer produces Cr-containing volatile species at SOFC operating temperatures and conditions, which can cause cathode poisoning. Electrically conducting spinel coatings have been developed to prevent cathode poisoning and to maintain an electrically conductive pathway through SOFC stacks. However, this coating is not compatible with the formation of stable, hermetic seals between the interconnect frame component and the ceramic cell. Thus, a new aluminizing process has been developed by PNNL to enable durable sealing, preventmore » Cr evaporation, and maintain electrical insulation between stack repeat units. Hence, two different types of coating need to have stable operation of SOFC stacks. This paper will focus on the electrically conductive coating process. Moreover, an advanced coating process, compatible with a non-electrically conductive coating will be« less

Heat and fuel coupled operation of a high temperature polymer electrolyte fuel cell with a heat exchanger methanol steam reformer

NASA Astrophysics Data System (ADS)

Schuller, G.; Vázquez, F. Vidal; Waiblinger, W.; Auvinen, S.; Ribeirinha, P.

2017-04-01

In this work a methanol steam reforming (MSR) reactor has been operated thermally coupled to a high temperature polymer electrolyte fuel cell stack (HT-PEMFC) utilizing its waste heat. The operating temperature of the coupled system was 180 °C which is significantly lower than the conventional operating temperature of the MSR process which is around 250 °C. A newly designed heat exchanger reformer has been developed by VTT (Technical Research Center of Finland LTD) and was equipped with commercially available CuO/ZnO/Al2O3 (BASF RP-60) catalyst. The liquid cooled, 165 cm2, 12-cell stack used for the measurements was supplied by Serenergy A/S. The off-heat from the electrochemical fuel cell reaction was transferred to the reforming reactor using triethylene glycol (TEG) as heat transfer fluid. The system was operated up to 0.4 A cm-2 generating an electrical power output of 427 Wel. A total stack waste heat utilization of 86.4% was achieved. It has been shown that it is possible to transfer sufficient heat from the fuel cell stack to the liquid circuit in order to provide the needed amount for vaporizing and reforming of the methanol-water-mixture. Furthermore a set of recommendations is given for future system design considerations.

Software systems for operation, control, and monitoring of the EBEX instrument

NASA Astrophysics Data System (ADS)

Milligan, Michael; Ade, Peter; Aubin, François; Baccigalupi, Carlo; Bao, Chaoyun; Borrill, Julian; Cantalupo, Christopher; Chapman, Daniel; Didier, Joy; Dobbs, Matt; Grainger, Will; Hanany, Shaul; Hillbrand, Seth; Hubmayr, Johannes; Hyland, Peter; Jaffe, Andrew; Johnson, Bradley; Kisner, Theodore; Klein, Jeff; Korotkov, Andrei; Leach, Sam; Lee, Adrian; Levinson, Lorne; Limon, Michele; MacDermid, Kevin; Matsumura, Tomotake; Miller, Amber; Pascale, Enzo; Polsgrove, Daniel; Ponthieu, Nicolas; Raach, Kate; Reichborn-Kjennerud, Britt; Sagiv, Ilan; Tran, Huan; Tucker, Gregory S.; Vinokurov, Yury; Yadav, Amit; Zaldarriaga, Matias; Zilic, Kyle

2010-07-01

We present the hardware and software systems implementing autonomous operation, distributed real-time monitoring, and control for the EBEX instrument. EBEX is a NASA-funded balloon-borne microwave polarimeter designed for a 14 day Antarctic flight that circumnavigates the pole. To meet its science goals the EBEX instrument autonomously executes several tasks in parallel: it collects attitude data and maintains pointing control in order to adhere to an observing schedule; tunes and operates up to 1920 TES bolometers and 120 SQUID amplifiers controlled by as many as 30 embedded computers; coordinates and dispatches jobs across an onboard computer network to manage this detector readout system; logs over 3 GiB/hour of science and housekeeping data to an onboard disk storage array; responds to a variety of commands and exogenous events; and downlinks multiple heterogeneous data streams representing a selected subset of the total logged data. Most of the systems implementing these functions have been tested during a recent engineering flight of the payload, and have proven to meet the target requirements. The EBEX ground segment couples uplink and downlink hardware to a client-server software stack, enabling real-time monitoring and command responsibility to be distributed across the public internet or other standard computer networks. Using the emerging dirfile standard as a uniform intermediate data format, a variety of front end programs provide access to different components and views of the downlinked data products. This distributed architecture was demonstrated operating across multiple widely dispersed sites prior to and during the EBEX engineering flight.

Active microchannel fluid processing unit and method of making

DOEpatents

Bennett, Wendy D [Kennewick, WA; Martin, Peter M [Kennewick, WA; Matson, Dean W [Kennewick, WA; Roberts, Gary L [West Richland, WA; Stewart, Donald C [Richland, WA; Tonkovich, Annalee Y [Pasco, WA; Zilka, Jennifer L [Pasco, WA; Schmitt, Stephen C [Dublin, OH; Werner, Timothy M [Columbus, OH

2001-01-01

The present invention is an active microchannel fluid processing unit and method of making, both relying on having (a) at least one inner thin sheet; (b) at least one outer thin sheet; (c) defining at least one first sub-assembly for performing at least one first unit operation by stacking a first of the at least one inner thin sheet in alternating contact with a first of the at least one outer thin sheet into a first stack and placing an end block on the at least one inner thin sheet, the at least one first sub-assembly having at least a first inlet and a first outlet; and (d) defining at least one second sub-assembly for performing at least one second unit operation either as a second flow path within the first stack or by stacking a second of the at least one inner thin sheet in alternating contact with second of the at least one outer thin sheet as a second stack, the at least one second sub-assembly having at least a second inlet and a second outlet.

Active microchannel fluid processing unit and method of making

DOEpatents

Bennett, Wendy D [Kennewick, WA; Martin, Peter M [Kennewick, WA; Matson, Dean W [Kennewick, WA; Roberts, Gary L [West Richland, WA; Stewart, Donald C [Richland, WA; Tonkovich, Annalee Y [Pasco, WA; Zilka, Jennifer L [Pasco, WA; Schmitt, Stephen C [Dublin, OH; Werner, Timothy M [Columbus, OH

2002-12-10

The present invention is an active microchannel fluid processing unit and method of making, both relying on having (a) at least one inner thin sheet; (b) at least one outer thin sheet; (c) defining at least one first sub-assembly for performing at least one first unit operation by stacking a first of the at least one inner thin sheet in alternating contact with a first of the at least one outer thin sheet into a first stack and placing an end block on the at least one inner thin sheet, the at least one first sub-assembly having at least a first inlet and a first outlet; and (d) defining at least one second sub-assembly for performing at least one second unit operation either as a second flow path within the first stack or by stacking a second of the at least one inner thin sheet in alternating contact with second of the at least one outer thin sheet as a second stack, the at least one second sub-assembly having at least a second inlet and a second outlet.

MONITORING OF INCINERATOR EMISSIONS

EPA Science Inventory

Monitoring of Incinerator Emissions is a chapter to be included in a book entitled Hazardous Waste Incineration, edited by A. Sarofim and D. Pershing, and published by John Wiley and Sons. he chapter describes stack sampling and analysis procedures in use on hazardous waste incin...

Electrolyte matrix in a molten carbonate fuel cell stack

DOEpatents

Reiser, C.A.; Maricle, D.L.

1987-04-21

A fuel cell stack is disclosed with modified electrolyte matrices for limiting the electrolytic pumping and electrolyte migration along the stack external surfaces. Each of the matrices includes marginal portions at the stack face of substantially greater pore size than that of the central body of the matrix. Consequently, these marginal portions have insufficient electrolyte fill to support pumping or wicking of electrolyte from the center of the stack of the face surfaces in contact with the vertical seals. Various configurations of the marginal portions include a complete perimeter, opposite edge portions corresponding to the air plenums and tab size portions corresponding to the manifold seal locations. These margins will substantially limit the migration of electrolyte to and along the porous manifold seals during operation of the electrochemical cell stack. 6 figs.

Electrolyte matrix in a molten carbonate fuel cell stack

DOEpatents

Reiser, Carl A.; Maricle, Donald L.

1987-04-21

A fuel cell stack is disclosed with modified electrolyte matrices for limiting the electrolytic pumping and electrolyte migration along the stack external surfaces. Each of the matrices includes marginal portions at the stack face of substantially greater pore size than that of the central body of the matrix. Consequently, these marginal portions have insufficient electrolyte fill to support pumping or wicking of electrolyte from the center of the stack of the face surfaces in contact with the vertical seals. Various configurations of the marginal portions include a complete perimeter, opposite edge portions corresponding to the air plenums and tab size portions corresponding to the manifold seal locations. These margins will substantially limit the migration of electrolyte to and along the porous manifold seals during operation of the electrochemical cell stack.

Commercialisation of Solid Oxide Fuel Cells - opportunities and forecasts

NASA Astrophysics Data System (ADS)

Dziurdzia, B.; Magonski, Z.; Jankowski, H.

2016-01-01

The paper presents the analysis of commercialisation possibilities of the SOFC stack designed at AGH. The paper reminds the final design of the stack, presented earlier at IMAPS- Poland conferences, its recent modifications and measurements. The stack consists of planar double-sided ceramic fuel cells which characterize by the special anode construction with embedded fuel channels. The stack features by a simple construction without metallic interconnectors and frames, lowered thermal capacity and quick start-up time. Predictions for the possible applications of the stack include portable generators for luxurious caravans, yachts, ships at berth. The SOFC stack operating as clean, quiet and efficient power source could replace on-board diesel generators. Market forecasts shows that there is also some room on a market for the SOFC stack as a standalone generator in rural areas far away from the grid. The paper presents also the survey of SOFC market in Europe USA, Australia and other countries.

Analysis of anabolic androgenic steroids in urine by full-capillary sample injection combined with a sweeping CE stacking method.

PubMed

Wang, Chun-Chi; Cheng, Shu-Fang; Cheng, Hui-Ling; Chen, Yen-Ling

2013-02-01

This study describes an on-line stacking CE approach by sweeping with whole capillary sample filling for analyzing five anabolic androgenic steroids in urine samples. The five anabolic steroids for detection were androstenedione, testosterone, epitestosterone, boldenone, and clostebol. Anabolic androgenic steroids are abused in sport doping because they can promote muscle growth. Therefore, a sensitive detection method is imperatively required for monitoring the urine samples of athletes. In this research, an interesting and reliable stacking capillary electrophoresis method was established for analysis of anabolic steroids in urine. After liquid-liquid extraction by n-hexane, the supernatant was dried and reconstituted with 30 mM phosphate buffer (pH 5.00) and loaded into the capillary by hydrodynamic injection (10 psi, 99.9 s). The stacking and separation were simultaneously accomplished at -20 kV in phosphate buffer (30 mM, pH 5.0) containing 100 mM sodium dodecyl sulfate and 40 % methanol. During the method validation, calibration curves were linear (r≥0.990) over a range of 50-1,000 ng/mL for the five analytes. In the evaluation of precision and accuracy for this method, the absolute values of the RSD and the RE in the intra-day (n=3) and inter-day (n=5) analyses were all less than 6.6 %. The limit of detection for the five analytes was 30 ng/mL (S/N=5, sampling 99.9 s at 10 psi). Compared with simple MECK, this stacking method possessed a 108- to 175-fold increase in sensitivity. This simple and sensitive stacking method could be used as a powerful tool for monitoring the illegal use of doping.

Design and operation of interconnectors for solid oxide fuel cell stacks

NASA Astrophysics Data System (ADS)

Winkler, W.; Koeppen, J.

Highly efficient combined cycles with solid oxide fuel cell (SOFC) need an integrated heat exchanger in the stack to reach efficiencies of about 80%. The stack costs must be lower than 1000 DM/kW. A newly developed welded metallic (Haynes HA 230) interconnector with a free stretching planar SOFC and an integrated heat exchanger was tested in thermal cycling operation. The design allowed a cycling of the SOFC without mechanical damage of the electrolyte in several tests. However, more tests and a further design optimization will be necessary. These results could indicate that commercial high-temperature alloys can be used as interconnector material in order to fullfil the cost requirements.

InSAR data for monitoring land subsidence: time to think big

NASA Astrophysics Data System (ADS)

Ferretti, A.; Colombo, D.; Fumagalli, A.; Novali, F.; Rucci, A.

2015-11-01

Satellite interferometric synthetic aperture radar (InSAR) data have proven effective and valuable in the analysis of urban subsidence phenomena based on multi-temporal radar images. Results obtained by processing data acquired by different radar sensors, have shown the potential of InSAR and highlighted the key points for an operational use of this technology, namely: (1) regular acquisition over large areas of interferometric data stacks; (2) use of advanced processing algorithms, capable of estimating and removing atmospheric disturbances; (3) access to significant processing power for a regular update of the information over large areas. In this paper, we show how the operational potential of InSAR has been realized thanks to the recent advances in InSAR processing algorithms, the advent of cloud computing and the launch of new satellite platforms, specifically designed for InSAR analyses (e.g. Sentinel-1a operated by the ESA and ALOS2 operated by JAXA). The processing of thousands of SAR scenes to cover an entire nation has been performed successfully in Italy in a project financed by the Italian Ministry of the Environment. The challenge for the future is to pass from the historical analysis of SAR scenes already acquired in digital archives to a near real-time monitoring program where up to date deformation data are routinely provided to final users and decision makers.

42. VIEW EAST OF PLASTIC STACK (PROBABLY PVC) WHICH VENTED ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

42. VIEW EAST OF PLASTIC STACK (PROBABLY PVC) WHICH VENTED FUMES FROM THE DIPPING OPERATIONS IN BUILDING 49A; BUILDING 49 IS AT THE LEFT OF THE PHOTOGRAPH - Scovill Brass Works, 59 Mill Street, Waterbury, New Haven County, CT

Non-Platinum Group Metal OER/ORR Catalysts for Alkaline Membrane Fuel Cells and Electrolyzers

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

Danilovic, Nemanja; Ayers, Katherine

Regenerative fuel cells (RFC) are energy storage devices that capture electrical energy in the form of hydrogen, with potential application for backup power and energy storage in remote locations, unmanned missions, and renewable energy capture. A unitized regenerative fuel cell (URFC) combines two separate electrochemical devices (fuel cell and electrolyzer) into one stack. The stack cost is driven by the platinum group metal (PGM) catalysts and the flow field components designed to withstand high potentials in acidic environments. Since the stack is the most expensive subcomponent of both the fuel cell and electrolyzer system, combining the two devices results inmore » substantial reduction in capital cost. However, in the past, combining the two stacks sacrificed device performance (operating cost) largely because the fuel cell had to operate with the thick electrolysis membranes in a URFC configuration, and due to water management issues in switching modes. Recent work in membrane-based electrolysis has resulted in more mechanically robust designs and materials that allow much thinner membranes, and work in flow cell design such as flow batteries has shown improved water transport through channel design and wet-proofing approaches. Therefore, the URFC concept is worth revisiting. At the same time, alkaline exchange membrane (AEM) devices are gathering attention due to the promise of PGM and valve metal elimination from the stack and a resulting strategic and capital cost benefit as compared with proton exchange membrane (PEM) systems. The result is a lower capital cost system that has half the precious metal group (PGM) catalysts, membrane and other stack component materials compared with discrete RFCs, although at the sacrifice of performance (operating cost). Proton has identified innovative AEM based RFC's to fulfill the role of low capital cost energy storage device owing to the use of non-precious metal containing electrodes, that enables certain markets where higher operating costs can be tolerated.« less

Tests of by-pass diodes at cryogenic temperatures for the KATRIN magnets

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

Gil, W.; Bolz, H.; Jansen, A.

The Karlsruhe Tritium Neutrino experiment (KATRIN) requires a series of superconducting solenoid magnets for guiding beta-electrons from the source to the detector. By-pass diodes will operate at liquid helium temperatures to protect the superconducting magnets and bus bars in case of quenches. The operation conditions of the by-pass diodes depend on the different magnet systems of KATRIN. Therefore, different diode stacks are designed with adequate copper heat sinks assuming adiabatic conditions. The by-pass diode stacks have been submitted to cold tests both at liquid nitrogen and liquid helium temperatures for checking operation conditions. This report presents the test set upmore » and first results of the diode characteristics at 300 K and 77 K, as well as of endurance tests of the diode stacks at constant current load at 77 K and 4.2 K.« less

Electrolytic cell stack with molten electrolyte migration control

DOEpatents

Kunz, H. Russell; Guthrie, Robin J.; Katz, Murray

1988-08-02

An electrolytic cell stack includes inactive electrolyte reservoirs at the upper and lower end portions thereof. The reservoirs are separated from the stack of the complete cells by impermeable, electrically conductive separators. Reservoirs at the negative end are initially low in electrolyte and the reservoirs at the positive end are high in electrolyte fill. During stack operation electrolyte migration from the positive to the negative end will be offset by the inactive reservoir capacity. In combination with the inactive reservoirs, a sealing member of high porosity and low electrolyte retention is employed to limit the electrolyte migration rate.

Electrolytic cell stack with molten electrolyte migration control

DOEpatents

Kunz, H.R.; Guthrie, R.J.; Katz, M.

1987-03-17

An electrolytic cell stack includes inactive electrolyte reservoirs at the upper and lower end portions thereof. The reservoirs are separated from the stack of the complete cells by impermeable, electrically conductive separators. Reservoirs at the negative end are initially low in electrolyte and the reservoirs at the positive end are high in electrolyte fill. During stack operation electrolyte migration from the positive to the negative end will be offset by the inactive reservoir capacity. In combination with the inactive reservoirs, a sealing member of high porosity and low electrolyte retention is employed to limit the electrolyte migration rate. 5 figs.

Improved 3D seismic attribute mapping by CRS stacking instead of NMO stacking: Application to a geothermal reservoir in the Polish Basin

NASA Astrophysics Data System (ADS)

Pussak, Marcin; Bauer, Klaus; Stiller, Manfred; Bujakowski, Wieslaw

2014-04-01

Within a seismic reflection processing work flow, the common-reflection-surface (CRS) stack can be applied as an alternative for the conventional normal moveout (NMO) or the dip moveout (DMO) stack. The advantages of the CRS stack include (1) data-driven automatic determination of stacking operator parameters, (2) imaging of arbitrarily curved geological boundaries, and (3) significant increase in signal-to-noise (S/N) ratio by stacking far more traces than used in a conventional stack. In this paper we applied both NMO and CRS stackings to process a sparse 3D seismic data set acquired within a geothermal exploration study in the Polish Basin. The stacked images show clear enhancements in quality achieved by the CRS stack in comparison with the conventional stack. While this was expected from previous studies, we also found remarkable improvements in the quality of seismic attributes when the CRS stack was applied instead of the conventional stack. For the major geothermal target reservoir (Lower Jurassic horizon Ja1), we present a comparison between both stacking methods for a number of common attributes, including root-mean-square (RMS) amplitudes, instantaneous frequencies, coherency, and spectral decomposition attributes derived from the continuous wavelet transform. The attribute maps appear noisy and highly fluctuating after the conventional stack, and are clearly structured after the CRS stack. A seismic facies analysis was finally carried out for the Ja1 horizon using the attributes derived from the CRS stack by using self-organizing map clustering techniques. A corridor parallel to a fault system was identified, which is characterized by decreased RMS amplitudes and decreased instantaneous frequencies. In our interpretation, this region represents a fractured, fluid-bearing compartment within the sandstone reservoir, which indicates favorable conditions for geothermal exploitation.

Radiation-Tolerant Intelligent Memory Stack - RTIMS

NASA Technical Reports Server (NTRS)

Ng, Tak-kwong; Herath, Jeffrey A.

2011-01-01

This innovation provides reconfigurable circuitry and 2-Gb of error-corrected or 1-Gb of triple-redundant digital memory in a small package. RTIMS uses circuit stacking of heterogeneous components and radiation shielding technologies. A reprogrammable field-programmable gate array (FPGA), six synchronous dynamic random access memories, linear regulator, and the radiation mitigation circuits are stacked into a module of 42.7 42.7 13 mm. Triple module redundancy, current limiting, configuration scrubbing, and single- event function interrupt detection are employed to mitigate radiation effects. The novel self-scrubbing and single event functional interrupt (SEFI) detection allows a relatively soft FPGA to become radiation tolerant without external scrubbing and monitoring hardware

40 CFR 60.4880 - How do I develop a site-specific monitoring plan for my continuous monitoring, bag leak detection...

Code of Federal Regulations, 2012 CFR

2012-07-01

... section are met. (A) The zero (low-level), mid-level (if applicable), or high-level calibration drift... representative of the relative or absolute particulate matter loadings for each exhaust stack, roof vent, or...

40 CFR 60.4880 - How do I develop a site-specific monitoring plan for my continuous monitoring, bag leak detection...

Code of Federal Regulations, 2014 CFR

2014-07-01

... section are met. (A) The zero (low-level), mid-level (if applicable), or high-level calibration drift... representative of the relative or absolute particulate matter loadings for each exhaust stack, roof vent, or...

40 CFR 60.4880 - How do I develop a site-specific monitoring plan for my continuous monitoring, bag leak detection...

Code of Federal Regulations, 2013 CFR

2013-07-01

... section are met. (A) The zero (low-level), mid-level (if applicable), or high-level calibration drift... representative of the relative or absolute particulate matter loadings for each exhaust stack, roof vent, or...

Design, fabrication and performance of a mixed-reactant membraneless micro direct methanol fuel cell stack

NASA Astrophysics Data System (ADS)

Abrego-Martínez, J. C.; Moreno-Zuria, A.; Cuevas-Muñiz, F. M.; Arriaga, L. G.; Sun, Shuhui; Mohamedi, Mohamed

2017-12-01

In the present work, we report the design, fabrication and evaluation of a membraneless mixed-reactant and air-breathing microfluidic direct methanol fuel cell (ML-μDMFC) stack operated in passive mode. The operation under mixed-reactant conditions was achieved by using a highly methanol-tolerant Ag/Pt/CP cathode with ultra-low Pt loading in alkaline medium. Prior to the fabrication of the stack, a flow simulation was made in order to study the behavior of the reactants stream in the microchannel through the 2 cells. Subsequently, the device was tested in passive mode using a mixture of 5 M MeOH +0.5 M KOH. The results showed that by connecting the 2 cells in series, it is possible to effectively double the voltage of a single ML-μDMFC, as well as increasing the absolute power by 75% with practically no cost increase. The stack was capable of operate continuously for more than 2 h with a single charge of 40 μL, producing an OCV of 0.89 V and a maximum power density of 3.33 mW mgPt-1. Additionally, the device exhibited good stability throughout a 10 h test.

Dynamic fiber Bragg grating strain sensor interrogation with real-time measurement

NASA Astrophysics Data System (ADS)

Park, Jinwoo; Kwon, Yong Seok; Ko, Myeong Ock; Jeon, Min Yong

2017-11-01

We demonstrate a 1550 nm band resonance Fourier-domain mode-locked (FDML) fiber laser with fiber Bragg grating (FBG) array. Using the FDML fiber laser, we successfully demonstrate real-time monitoring of dynamic FBG strain sensor interrogation for structural health monitoring. The resonance FDML fiber laser consists of six multiplexed FBGs, which are arranged in series with delay fiber lengths. It is operated by driving the fiber Fabry-Perot tunable filter (FFP-TF) with a sinusoidal waveform at a frequency corresponding to the round-trip time of the laser cavity. Each FBG forms a laser cavity independently in the FDML fiber laser because the light travels different length for each FBG. The very closely positioned two FBGs in a pair are operated simultaneously with a frequency in the FDML fiber laser. The spatial positions of the sensing pair can be distinguished from the variation of the applied frequency to the FFP-TF. One of the FBGs in the pair is used as a reference signal and the other one is fixed on the piezoelectric transducer stack to apply the dynamic strain. We successfully achieve real-time measurement of the abrupt change of the frequencies applied to the FBG without any signal processing delay. The real-time monitoring system is displayed simultaneously on the monitor for the variation of the two peaks, the modulation interval of the two peaks, and their fast Fourier transform spectrum. The frequency resolution of the dynamic variation could reach up to 0.5 Hz for 2 s integration time. It depends on the integration time to measure the dynamic variation. We believe that the real-time monitoring system will have a potential application for structural health monitoring.

Toward Wireless Health Monitoring via an Analog Signal Compression-Based Biosensing Platform.

PubMed

Zhao, Xueyuan; Sadhu, Vidyasagar; Le, Tuan; Pompili, Dario; Javanmard, Mehdi

2018-06-01

Wireless all-analog biosensor design for the concurrent microfluidic and physiological signal monitoring is presented in this paper. The key component is an all-analog circuit capable of compressing two analog sources into one analog signal by the analog joint source-channel coding (AJSCC). Two circuit designs are discussed, including the stacked-voltage-controlled voltage source (VCVS) design with the fixed number of levels, and an improved design, which supports a flexible number of AJSCC levels. Experimental results are presented on the wireless biosensor prototype, composed of printed circuit board realizations of the stacked-VCVS design. Furthermore, circuit simulation and wireless link simulation results are presented on the improved design. Results indicate that the proposed wireless biosensor is well suited for sensing two biological signals simultaneously with high accuracy, and can be applied to a wide variety of low-power and low-cost wireless continuous health monitoring applications.

Phosphoric and electric utility fuel cell technology development

NASA Astrophysics Data System (ADS)

Breault, R. D.; Briggs, T. A.; Congdon, J. V.; Demarche, T. E.; Gelting, R. L.; Goller, G. J.; Luoma, W. I.; McCloskey, M. W.; Mientek, A. P.; Obrien, J. J.

1984-01-01

The advancement of electric utility cell stack technology and reduction of cell stack cost was initiated. The cell stack has a nominal 10 ft (2) active area and operates at 120 psia/405(0)F. The program comprises six parallel phases, which culminate in a full height, 10-ft(2) stack verification test: (1) provides the information and services needed to manage the effort, including definition of the prototype commercial power plant; (2) develops the technical base for long term improvements to the cell stack; (3) develops materials and processing techniques for cell stack components incorporating the best available technology; (4) provides the design of hardware and conceptual processing layouts, and updates the power plant definition of Phase 1 to reflect the results of Phases 2 and 3; Phase 5 manufactures the hardware to verify the achievements of Phases 2 and 3, and analyzes the cost of this hardware; and Phase 6 tests the cell stacks assembled from the hardware of Phase 5 to assess the state of development.

Evaluation of a 2.5 kWel automotive low temperature PEM fuel cell stack with extended operating temperature range up to 120 °C

NASA Astrophysics Data System (ADS)

Ruiu, Tiziana; Dreizler, Andreas M.; Mitzel, Jens; Gülzow, Erich

2016-01-01

Nowadays, the operating temperature of polymer electrolyte membrane fuel cell stacks is typically limited to 80 °C due to water management issues of membrane materials. In the present work, short-term operation at elevated temperatures up to 120 °C and long-term steady-state operation under automotive relevant conditions at 80 °C are examined using a 30-cell stack developed at DLR. The high temperature behavior is investigated by using temperature cycles between 90 and 120 °C without adjustment of the gases dew points, to simulate a short-period temperature increase, possibly caused by an extended power demand and/or limited heat removal. This galvanostatic test demonstrates a fully reversible performance decrease of 21 ± 1% during each thermal cycle. The irreversible degradation rate is about a factor of 6 higher compared to the one determined by the long-term test. The 1200-h test at 80 °C demonstrates linear stack voltage decay with acceptable degradation rate, apart from a malfunction of the air compressor, which results in increased catalyst degradation effects on individual cells. This interpretation is based on an end-of-life characterization, aimed to investigate catalyst, electrode and membrane degradation, by determining hydrogen crossover rates, high frequency resistances, electrochemically active surface areas and catalyst particle sizes.

Classification of Reactor Facility Operational State Using SPRT Methods with Radiation Sensor Networks

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

Ramirez Aviles, Camila A.; Rao, Nageswara S.

We consider the problem of inferring the operational state of a reactor facility by using measurements from a radiation sensor network, which is deployed around the facility’s ventilation stack. The radiation emissions from the stack decay with distance, and the corresponding measurements are inherently random with parameters determined by radiation intensity levels at the sensor locations. We fuse measurements from network sensors to estimate the intensity at the stack, and use this estimate in a one-sided Sequential Probability Ratio Test (SPRT) to infer the on/off state of the reactor facility. We demonstrate the superior performance of this method over conventionalmore » majority vote fusers and individual sensors using (i) test measurements from a network of NaI sensors, and (ii) emulated measurements using radioactive effluents collected at a reactor facility stack. We analytically quantify the performance improvements of individual sensors and their networks with adaptive thresholds over those with fixed ones, by using the packing number of the radiation intensity space.« less

Electrolyte paste for molten carbonate fuel cells

DOEpatents

Bregoli, Lawrance J.; Pearson, Mark L.

1995-01-01

The electrolyte matrix and electrolyte reservoir plates in a molten carbonate fuel cell power plant stack are filled with electrolyte by applying a paste of dry electrolyte powder entrained in a dissipatable carrier to the reactant flow channels in the current collector plate. The stack plates are preformed and solidified to final operating condition so that they are self sustaining and can be disposed one atop the other to form the power plant stack. Packing the reactant flow channels with the electrolyte paste allows the use of thinner electrode plates, particularly on the anode side of the cells. The use of the packed electrolyte paste provides sufficient electrolyte to fill the matrix and to entrain excess electrolyte in the electrode plates, which also serve as excess electrolyte reservoirs. When the stack is heated up to operating temperatures, the electrolyte in the paste melts, the carrier vaporizes, or chemically decomposes, and the melted electrolyte is absorbed into the matrix and electrode plates.

Assessment of the LV-C2 Stack Sampling Probe Location for Compliance with ANSI/HPS N13.1-1999

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

Glissmeyer, John A.; Antonio, Ernest J.; Flaherty, Julia E.

2015-09-01

This document reports on a series of tests conducted to assess the proposed air sampling location for the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Low-Activity Waste (LAW) C2V (LV-C2) exhaust stack with respect to the applicable criteria regarding the placement of an air sampling probe. Federal regulations require that a sampling probe be located in the exhaust stack according to the criteria established by the American National Standards Institute/Health Physics Society (ANSI/HPS) N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities. These criteria address the capability of the sampling probemore » to extract a sample that represents the effluent stream. The tests were conducted on the LV-C2 scale model system. Based on the scale model tests, the location proposed for the air sampling probe in the scale model stack meets the requirements of the ANSI/HPS N13.1-1999 standard for velocity uniformity, flow angle, gas tracer and particle tracer uniformity. Additional velocity uniformity and flow angle tests on the actual stack will be necessary during cold startup to confirm the validity of the scale model results in representing the actual stack.« less

Numerical simulation of a mini PEMFC stack

NASA Astrophysics Data System (ADS)

Liu, Zhixiang; Mao, Zongqiang; Wang, Cheng; Zhuge, Weilin; Zhang, Yangjun

Fuel cell modeling and simulation has aroused much attention recently because it can probe transport and reaction mechanism. In this paper, a computational fuel cell dynamics (CFCD) method was applied to simulate a proton exchange membrane fuel cell (PEMFC) stack for the first time. The air cooling mini fuel cell stack consisted of six cells, in which the active area was 8 cm 2 (2 cm × 4 cm). With reasonable simplification, the computational elements were effectively reduced and allowed a simulation which could be conducted on a personal computer without large-scale parallel computation. The results indicated that the temperature gradient inside the fuel cell stack was determined by the flow rate of the cooling air. If the air flow rate is too low, the stack could not be effectively cooled and the temperature will rise to a range that might cause unstable stack operation.

High Temperature Electrolysis 4 kW Experiment Design, Operation, and Results

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

J.E. O'Brien; X. Zhang; K. DeWall

2012-09-01

This report provides results of long-term stack testing completed in the new high-temperature steam electrolysis multi-kW test facility recently developed at INL. The report includes detailed descriptions of the piping layout, steam generation and delivery system, test fixture, heat recuperation system, hot zone, instrumentation, and operating conditions. This facility has provided a demonstration of high-temperature steam electrolysis operation at the 4 kW scale with advanced cell and stack technology. This successful large-scale demonstration of high-temperature steam electrolysis will help to advance the technology toward near-term commercialization.

Application of IDT Sensors for Structural Health Monitoring of Windmill Turbine Blades Made of Composite Material

NASA Astrophysics Data System (ADS)

Nalladega, V.; Na, J. K.; Druffner, C.

2011-06-01

Interdigital transducers (IDT) generate and receive ultrasonic surface waves without the complexity involved with secondary devices such as angled wedges or combs. The IDT sensors have been successfully applied for the NDE of homogeneous materials like metals in order to detect cracks and de-bond. However, these transducers have not been yet adapted for complex and anisotropic materials like fiber-reinforced composites. This work presents the possibility of using IDT sensors for monitoring structural damages in wind turbine blades, typically made of fiberglass composites. IDT sensors with a range of operating frequency between 250 kHz and 1 MHz are initially tested on representative composite test panels for ultrasonic surface wave properties including beam spread, propagation distance and effect of material's anisotropy. Based on these results, an optimum frequency range for the IDT sensor is found to be 250-500 kHz. Subsequently, IDT sensors with operating frequency 500 kHz are used to detect and quantify artificial defects created in the composite test samples. Discussions are made on the interaction of ultrasonic fields with these defects along with the effects of fiber directionality and composite layer stacking.

Acoustic streaming related to minor loss phenomenon in differentially heated elements of thermoacoustic devices

NASA Astrophysics Data System (ADS)

Mironov, Mikhail; Gusev, Vitalyi; Auregan, Yves; Lotton, Pierrick; Bruneau, Michel; Piatakov, Pavel

2002-08-01

It is demonstrated that the differentially heated stack, the heart of all thermoacoustic devices, provides a source of streaming additional to those associated with Reynolds stresses in quasi-unidirectional gas flow. This source of streaming is related to temperature-induced asymmetry in the generation of vortices and turbulence near the stack ends. The asymmetry of the hydrodynamic effects in an otherwise geometrically symmetric stack is due to the temperature difference between stack ends. The proposed mechanism of streaming excitation in annular thermoacoustic devices operates even in the absence of thermo-viscous interaction of sound waves with resonator walls. copyright 2002 Acoustical Society of America.

UTC Power/Delphi SECA CBS Final Report

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

Gorman, Michael; Kerr, Rich

2013-04-04

The subject report summarizes the results of solid oxide fuel cell development conducted by UTC Power in conjunction with Delphi Automotive Systems under a cost-share program with from October 2008 through March of 2013. Over that period Delphi Automotive Systems developed a nearly four times larger area solid oxide fuel cell stack capable of operating on pre-reformed natural gas and simulated coal gas with durability demonstrated to 5,000 hours and projected to exceed 10,000 hours. The new stack design was scaled to 40-cell stacks with power output in excess of 6.25kW. Delphi also made significant strides in improving the manufacturability,more » yield and production cost of these solid oxide fuel cells over the course of the program. Concurrently, UTC Power developed a conceptual design for a 120 MW Integrated Gasification Fuel Cell (IGFC) operating on coal syngas with as high as 57% Higher Heating Value (HHV) efficiency as a measure of the feasibility of the technology. Subsequently a 400 kW on-site system preliminary design with 55% Lower Heating Value (LHV) efficiency operating on natural gas was down-selected from eighteen candidate designs. That design was used as the basis for a 25kW breadboard power plant incorporating four Delphi cell stacks that was tested on natural gas before the program was discontinued due to the sale of UTC Power in early 2013. Though the program was cut short of the endurance target of 3,000 hours, many aspects of the technology were proven including: large-area, repeatable cell manufacture, cell stack operation on simulated coal gas and natural gas and integrated power plant operation on natural gas. The potential of the technology for high efficiency stationary electric power generation is clear. Acceptable production costs, durability, and reliability in real world environments are the remaining challenges to commercialization.« less

Final Report - MEA and Stack Durability for PEM Fuel Cells

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

Yandrasits, Michael A.

2008-02-15

Proton exchange membrane fuel cells are expected to change the landscape of power generation over the next ten years. For this to be realized one of the most significant challenges to be met for stationary systems is lifetime, where 40,000 hours of operation with less than 10% decay is desired. This project conducted fundamental studies on the durability of membrane electrode assemblies (MEAs) and fuel cell stack systems with the expectation that knowledge gained from this project will be applied toward the design and manufacture of MEAs and stack systems to meet DOE’s 2010 stationary fuel cell stack systems targets.more » The focus of this project was PEM fuel cell durability – understanding the issues that limit MEA and fuel cell system lifetime, developing mitigation strategies to address the lifetime issues and demonstration of the effectiveness of the mitigation strategies by system testing. To that end, several discoveries were made that contributed to the fundamental understanding of MEA degradation mechanisms. (1) The classically held belief that membrane degradation is solely due to end-group “unzipping” is incorrect; there are other functional groups present in the ionomer that are susceptible to chemical attack. (2) The rate of membrane degradation can be greatly slowed or possibly eliminated through the use of additives that scavenge peroxide or peroxyl radicals. (3) Characterization of GDL using dry gases is incorrect due to the fact that fuel cells operate utilizing humidified gases. The proper characterization method involves using wet gas streams and measuring capillary pressure as demonstrated in this project. (4) Not all Platinum on carbon catalysts are created equally – the major factor impacting catalyst durability is the type of carbon used as the support. (5) System operating conditions have a significant impact of lifetime – the lifetime was increased by an order of magnitude by changing the load profile while all other variables remain the same. (6) Through the use of statistical lifetime analysis methods, it is possible to develop new MEAs with predicted durability approaching the DOE 2010 targets. (7) A segmented cell was developed that extend the resolution from ~ 40 to 121 segments for a 50cm2 active area single cell which allowed for more precise investigation of the local phenomena in a operating fuel cell. (8) The single cell concept was extended to a fuel size stack to allow the first of its kind monitoring and mapping of an operational fuel cell stack. An internal check used during this project involved evaluating the manufacturability of any new MEA component. If a more durable MEA component was developed in the lab, but could not be scaled-up to ‘high speed, high volume manufacturing’, then that component was not selected for the final MEA-fuel cell system demonstration. It is the intent of the team to commercialize new products developed under this project, but commercialization can not occur if the manufacture of said new components is difficult or if the price is significantly greater than existing products as to make the new components not cost competitive. Thus, the end result of this project is the creation of MEA and fuel cell system technology that is capable of meeting the DOEs 2010 target of 40,000 hours for stationary fuel cell systems (although this lifetime has not been demonstrated in laboratory or field testing yet) at a cost that is economically viable for the developing fuel cell industry. We have demonstrated over 2,000 hours of run time for the MEA and system developed under this project.« less

Smart rock technology for real-time monitoring of bridge scour and riprap effectiveness - design guidelines and visualization tool.

DOT National Transportation Integrated Search

2016-12-31

This study aims to further develop and demonstrate the recently-proposed smart rock technology for : scour depth and protection effectiveness monitoring. A smart rock is one or two stacked magnets encased : in a concrete sphere with a specially-desig...

40 CFR 75.22 - Reference test methods.

Code of Federal Regulations, 2011 CFR

2011-07-01

... recertification of continuous emission monitoring Systems; NOX emission tests of low mass emission units under... continuous moisture monitoring systems are conducted. For the purpose of determining the stack gas molecular... traverse requirement of the method; (iv) Section 8.6 of the method allowing for the use of “Dynamic Spiking...

40 CFR 63.323 - Test methods and monitoring.

Code of Federal Regulations, 2012 CFR

2012-07-01

... downstream from any flow disturbance such as a bend, expansion, contraction, or outlet; downstream from no other inlet; and 2 stack or duct diameters upstream from any flow disturbance such as a bend, expansion... monitoring by inserting the colorimetric detector or PCE gas analyzer tube into the open space above the...

40 CFR 63.323 - Test methods and monitoring.

Code of Federal Regulations, 2014 CFR

2014-07-01

... downstream from any flow disturbance such as a bend, expansion, contraction, or outlet; downstream from no other inlet; and 2 stack or duct diameters upstream from any flow disturbance such as a bend, expansion... monitoring by inserting the colorimetric detector or PCE gas analyzer tube into the open space above the...

40 CFR 63.323 - Test methods and monitoring.

Code of Federal Regulations, 2013 CFR

2013-07-01

... downstream from any flow disturbance such as a bend, expansion, contraction, or outlet; downstream from no other inlet; and 2 stack or duct diameters upstream from any flow disturbance such as a bend, expansion... monitoring by inserting the colorimetric detector or PCE gas analyzer tube into the open space above the...

40 CFR 60.717 - Reporting and monitoring requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... in § 60.713(b)(1) (liquid material balance); (2) The VOC contained in the coatings for the... monitoring only the carbon adsorption system outlet concentration levels of organic compounds, the periods.... (i) For carbon adsorption systems with a common exhaust stack for all the individual adsorber vessels...

40 CFR 60.717 - Reporting and monitoring requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... in § 60.713(b)(1) (liquid material balance); (2) The VOC contained in the coatings for the... monitoring only the carbon adsorption system outlet concentration levels of organic compounds, the periods.... (i) For carbon adsorption systems with a common exhaust stack for all the individual adsorber vessels...

40 CFR 60.717 - Reporting and monitoring requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... in § 60.713(b)(1) (liquid material balance); (2) The VOC contained in the coatings for the... monitoring only the carbon adsorption system outlet concentration levels of organic compounds, the periods.... (i) For carbon adsorption systems with a common exhaust stack for all the individual adsorber vessels...

40 CFR 60.717 - Reporting and monitoring requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... in § 60.713(b)(1) (liquid material balance); (2) The VOC contained in the coatings for the... monitoring only the carbon adsorption system outlet concentration levels of organic compounds, the periods.... (i) For carbon adsorption systems with a common exhaust stack for all the individual adsorber vessels...

40 CFR 60.717 - Reporting and monitoring requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... in § 60.713(b)(1) (liquid material balance); (2) The VOC contained in the coatings for the... monitoring only the carbon adsorption system outlet concentration levels of organic compounds, the periods.... (i) For carbon adsorption systems with a common exhaust stack for all the individual adsorber vessels...

40 CFR 60.5200 - How do I develop a site-specific monitoring plan for my continuous monitoring, bag leak detection...

Code of Federal Regulations, 2012 CFR

2012-07-01

... control if the conditions of paragraph (a)(7)(i)(A) or (a)(7)(i)(B) of this section are met. (A) The zero... representative of the relative or absolute particulate matter loadings for each exhaust stack, roof vent, or...

40 CFR 60.5200 - How do I develop a site-specific monitoring plan for my continuous monitoring, bag leak detection...

Code of Federal Regulations, 2014 CFR

2014-07-01

... control if the conditions of paragraph (a)(7)(i)(A) or (a)(7)(i)(B) of this section are met. (A) The zero... representative of the relative or absolute particulate matter loadings for each exhaust stack, roof vent, or...

40 CFR 60.5200 - How do I develop a site-specific monitoring plan for my continuous monitoring, bag leak detection...

Code of Federal Regulations, 2013 CFR

2013-07-01

... control if the conditions of paragraph (a)(7)(i)(A) or (a)(7)(i)(B) of this section are met. (A) The zero... representative of the relative or absolute particulate matter loadings for each exhaust stack, roof vent, or...

40 CFR 75.66 - Petitions to the Administrator.

Code of Federal Regulations, 2014 CFR

2014-07-01

... for each submission. (b) Alternative flow monitoring method petition. In cases where no location exists for installation of a flow monitor in either the stack or the ducts serving an affected unit that satisfies the minimum physical siting criteria in appendix A of this part or where installation of a flow...

40 CFR 75.66 - Petitions to the Administrator.

Code of Federal Regulations, 2013 CFR

2013-07-01

... for each submission. (b) Alternative flow monitoring method petition. In cases where no location exists for installation of a flow monitor in either the stack or the ducts serving an affected unit that satisfies the minimum physical siting criteria in appendix A of this part or where installation of a flow...

40 CFR 75.66 - Petitions to the Administrator.

Code of Federal Regulations, 2011 CFR

2011-07-01

... for each submission. (b) Alternative flow monitoring method petition. In cases where no location exists for installation of a flow monitor in either the stack or the ducts serving an affected unit that satisfies the minimum physical siting criteria in appendix A of this part or where installation of a flow...

40 CFR 75.66 - Petitions to the Administrator.

Code of Federal Regulations, 2012 CFR

2012-07-01

... for each submission. (b) Alternative flow monitoring method petition. In cases where no location exists for installation of a flow monitor in either the stack or the ducts serving an affected unit that satisfies the minimum physical siting criteria in appendix A of this part or where installation of a flow...

40 CFR 61.33 - Stack sampling.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Stack sampling. 61.33 Section 61.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... sampling. (a) Unless a waiver of emission testing is obtained under § 61.13, each owner or operator...

40 CFR 61.33 - Stack sampling.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 8 2011-07-01 2011-07-01 false Stack sampling. 61.33 Section 61.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... sampling. (a) Unless a waiver of emission testing is obtained under § 61.13, each owner or operator...

Memory and Energy Optimization Strategies for Multithreaded Operating System on the Resource-Constrained Wireless Sensor Node

PubMed Central

Liu, Xing; Hou, Kun Mean; de Vaulx, Christophe; Xu, Jun; Yang, Jianfeng; Zhou, Haiying; Shi, Hongling; Zhou, Peng

2015-01-01

Memory and energy optimization strategies are essential for the resource-constrained wireless sensor network (WSN) nodes. In this article, a new memory-optimized and energy-optimized multithreaded WSN operating system (OS) LiveOS is designed and implemented. Memory cost of LiveOS is optimized by using the stack-shifting hybrid scheduling approach. Different from the traditional multithreaded OS in which thread stacks are allocated statically by the pre-reservation, thread stacks in LiveOS are allocated dynamically by using the stack-shifting technique. As a result, memory waste problems caused by the static pre-reservation can be avoided. In addition to the stack-shifting dynamic allocation approach, the hybrid scheduling mechanism which can decrease both the thread scheduling overhead and the thread stack number is also implemented in LiveOS. With these mechanisms, the stack memory cost of LiveOS can be reduced more than 50% if compared to that of a traditional multithreaded OS. Not is memory cost optimized, but also the energy cost is optimized in LiveOS, and this is achieved by using the multi-core “context aware” and multi-core “power-off/wakeup” energy conservation approaches. By using these approaches, energy cost of LiveOS can be reduced more than 30% when compared to the single-core WSN system. Memory and energy optimization strategies in LiveOS not only prolong the lifetime of WSN nodes, but also make the multithreaded OS feasible to run on the memory-constrained WSN nodes. PMID:25545264

Sustainable water desalination and electricity generation in a separator coupled stacked microbial desalination cell with buffer free electrolyte circulation.

PubMed

Chen, Xi; Liang, Peng; Wei, Zhimou; Zhang, Xiaoyuan; Huang, Xia

2012-09-01

A separator coupled circulation stacked microbial desalination cell (c-SMDC-S) was constructed to stabilize the pH imbalances in MDCs without buffer solution and achieved the stable desalination. The long-term operation of c-SMDC-S, regular stacked MDC (SMDC) and no separator coupled circulation SMDC (c-SMDC) were tested. The SMDC and c-SMDC could only stably operate for 1 week and 1 month owing to dramatic anolyte pH decrease and serious biofilm growth on the air cathode, respectively. The c-SMDC-S gained in anolyte alkalinity and operated stably for about 60 days without the thick biofilm growth on cathode. Besides, the chemical oxygen demand removal and coulombic efficiency were 64 ± 6% and 30 ± 2%, higher than that of SMDC and c-SMDC, respectively. It was concluded that the circulation of alkalinity could remove pH imbalance while the separator could expand the operation period and promote the conversion of organic matter to electricity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Progress in the planar CPn SOFC system design verification

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

Elangovan, S.; Hartvigsen, J.; Khandkar, A.

1996-04-01

SOFCo is developing a high efficiency, modular and scaleable planar SOFC module termed the CPn design. This design has been verified in a 1.4 kW module test operated directly on pipeline natural gas. The design features multistage oxidation of fuel wherein the fuel is consumed incrementally over several stages. High efficiency is achieved by uniform current density distribution per stage, which lowers the stack resistance. Additional benefits include thermal regulation and compactness. Test results from stack modules operating in pipeline natural gas are presented.

Electrodialysis operation with buffer solution

DOEpatents

Hryn, John N [Naperville, IL; Daniels, Edward J [Orland Park, IL; Krumdick, Greg K [Crete, IL

2009-12-15

A new method for improving the efficiency of electrodialysis (ED) cells and stacks, in particular those used in chemical synthesis. The process entails adding a buffer solution to the stack for subsequent depletion in the stack during electrolysis. The buffer solution is regenerated continuously after depletion. This buffer process serves to control the hydrogen ion or hydroxide ion concentration so as to protect the active sites of electrodialysis membranes. The process enables electrodialysis processing options for products that are sensitive to pH changes.

Motion Imagery and Robotics Application (MIRA)

NASA Technical Reports Server (NTRS)

Martinez, Lindolfo; Rich, Thomas

2011-01-01

Objectives include: I. Prototype a camera service leveraging the CCSDS Integrated protocol stack (MIRA/SM&C/AMS/DTN): a) CCSDS MIRA Service (New). b) Spacecraft Monitor and Control (SM&C). c) Asynchronous Messaging Service (AMS). d) Delay/Disruption Tolerant Networking (DTN). II. Additional MIRA Objectives: a) Demo of Camera Control through ISS using CCSDS protocol stack (Berlin, May 2011). b) Verify that the CCSDS standards stack can provide end-to-end space camera services across ground and space environments. c) Test interoperability of various CCSDS protocol standards. d) Identify overlaps in the design and implementations of the CCSDS protocol standards. e) Identify software incompatibilities in the CCSDS stack interfaces. f) Provide redlines to the SM&C, AMS, and DTN working groups. d) Enable the CCSDS MIRA service for potential use in ISS Kibo camera commanding. e) Assist in long-term evolution of this entire group of CCSDS standards to TRL 6 or greater.

On the interplay between chirality and exciton coupling: a DFT calculation of the circular dichroism in π-stacked ethylene.

PubMed

Norman, Patrick; Linares, Mathieu

2014-09-01

The chirality of stacked weakly interacting π-systems was interpreted in terms of Frenkel exciton states and the formation of excitonic circular dichroism (CD) bands was monitored for ethylene stacks of varying sizes. Convergence of CD bands with respect to the system size was observed for stacks involving around 10 molecules. By means of rotation around the C-C double bond in ethylene, chirality was induced in the monomeric system and which was shown to dominate the spectral responses, even for polymer aggregates. In helical assemblies of chiral entities, there will always be a mix of excitonic and monomeric contributions to the CD signal and it is demonstrated that the complex polarization propagator approach in combination with Density Functional Theory is a suitable method to address this situation. © 2014 Wiley Periodicals, Inc.

A CMOS image sensor with stacked photodiodes for lensless observation system of digital enzyme-linked immunosorbent assay

NASA Astrophysics Data System (ADS)

Takehara, Hironari; Miyazawa, Kazuya; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Kim, Soo Hyeon; Iino, Ryota; Noji, Hiroyuki; Ohta, Jun

2014-01-01

A CMOS image sensor with stacked photodiodes was fabricated using 0.18 µm mixed signal CMOS process technology. Two photodiodes were stacked at the same position of each pixel of the CMOS image sensor. The stacked photodiodes consist of shallow high-concentration N-type layer (N+), P-type well (PW), deep N-type well (DNW), and P-type substrate (P-sub). PW and P-sub were shorted to ground. By monitoring the voltage of N+ and DNW individually, we can observe two monochromatic colors simultaneously without using any color filters. The CMOS image sensor is suitable for fluorescence imaging, especially contact imaging such as a lensless observation system of digital enzyme-linked immunosorbent assay (ELISA). Since the fluorescence increases with time in digital ELISA, it is possible to observe fluorescence accurately by calculating the difference from the initial relation between the pixel values for both photodiodes.

ESTIMATION OF THE SPACE SHUTTLE ROLLOUT FORCING FUNCTION

NASA Technical Reports Server (NTRS)

James, George H., III; Carne, Thomas; Elliott, Kenny; Wilson, Bruce

2005-01-01

The Space Shuttle Vehicle is assembled in the Vertical Assembly Building (VAB) at Kennedy Space Flight Center in Florida. The Vehicle is stacked on a Mobile Launch Platform (MLP) that weighs eight million pounds. A Crawler Transporter (CT) then carries the MLP and the stacked vehicle (12 million pounds total weight) to the launch complex located 5 miles away. This operation is performed at 0.9 mph resulting in a 4.5-hour transport. A recent test was performed to monitor the dynamic environment that was produced during rollout. It was found that the rollout is a harmonic-rich dynamic environment that was previously not understood. This paper will describe work that has been performed to estimate the forcing function that is produced in the transportation process. The rollout analysis team has determined that there are two families of harmonics of the drive train, which excite the system as a function of CT speed. There are also excitation sources, which are random or narrow-band in frequency and are not a function of CT speed. This presentation will discuss the application of the Sum of Weighted Accelerations Technique (SWAT) to further refine this understanding by estimating the forces and moments at the center-of-mass.

A Study of the Ethernet Troughput Performance of the Embedded System

NASA Astrophysics Data System (ADS)

Duan, Zhi-Yu; Zhao, Zhao-Wang

2007-09-01

An ethernet acceleration solution developed for the NIOS II Embedded System in astronomical applications - Mason Express is introduced in this paper. By manually constructing the proper network protocol headers and directly driving the hardware, Mason Express goes around the performance bottleneck of the Light Weighted IP stack (LWIP), and achieves up to 90Mb/s unidirectional data troughput rate from the embedded system board to the data collecting computer. With the LWIP stack, the maximum data rate is about 10.57Mb/s. Mason Express is a total software solution and no hardware changes required, neither does it affect the uCOS II operating system nor the LWIP stack, and can be implemented with or without any embedded operating system. It maximally protects the intelligence investment of the users.

Pressure Dome for High-Pressure Electrolyzer

NASA Technical Reports Server (NTRS)

Norman, Timothy; Schmitt, Edwin

2012-01-01

A high-strength, low-weight pressure vessel dome was designed specifically to house a high-pressure [2,000 psi (approx. = 13.8 MPa)] electrolyzer. In operation, the dome is filled with an inert gas pressurized to roughly 100 psi (approx. = 690 kPa) above the high, balanced pressure product oxygen and hydrogen gas streams. The inert gas acts to reduce the clamping load on electrolyzer stack tie bolts since the dome pressure acting axially inward helps offset the outward axial forces from the stack gas pressure. Likewise, radial and circumferential stresses on electrolyzer frames are minimized. Because the dome is operated at a higher pressure than the electrolyzer product gas, any external electrolyzer leak prevents oxygen or hydrogen from leaking into the dome. Instead the affected stack gas stream pressure rises detectably, thereby enabling a system shutdown. All electrical and fluid connections to the stack are made inside the pressure dome and require special plumbing and electrical dome interfaces for this to be accomplished. Further benefits of the dome are that it can act as a containment shield in the unlikely event of a catastrophic failure. Studies indicate that, for a given active area (and hence, cell ID), frame outside diameter must become ever larger to support stresses at higher operating pressures. This can lead to a large footprint and increased costs associated with thicker and/or larger diameter end-plates, tie-rods, and the frames themselves. One solution is to employ rings that fit snugly around the frame. This complicates stack assembly and is sometimes difficult to achieve in practice, as its success is strongly dependent on frame and ring tolerances, gas pressure, and operating temperature. A pressure dome permits an otherwise low-pressure stack to operate at higher pressures without growing the electrolyzer hardware. The pressure dome consists of two machined segments. An O-ring is placed in an O-ring groove in the flange of the bottom segment and is trapped by the flange on the top dome segment when these components are bolted together with high-strength bolts. The pressure dome has several unique features. It is made (to ASME Pressure Vessel guidelines) in a high-strength aluminum alloy with the strength of stainless steel and the weight benefits of aluminum. The flange of the upper dome portion contains specially machined flats for mounting the dome, and other flats dedicated to the special feedthroughs for electrical connections. A pressure dome can be increased in length to house larger stacks (more cells) of the same diameter with the simple addition of a cylindrical segment. To aid in dome assembly, two stainless steel rings are employed. One is used beneath the heads of the high-strength bolts in lieu of individual hardened washers, and another is used instead of individual nuts. Like electrolyzers could be operated at low or high pressures simply by operating the electrolyzer outside or inside a pressurized dome.

Extended Life PZT Stack Test Fixture

NASA Technical Reports Server (NTRS)

Badescu, Mircea; Sherrit, S.; Bao, X.; Aldrich, J.; Bar-Cohen, Y.; Jones, C.

2009-01-01

Piezoelectric stacks are being sought to be used as actuators for precision positioning and deployment of mechanisms in future planetary missions. Beside the requirement for very high operation reliability, these actuators are required for operation at space environments that are considered harsh compared to normal terrestrial conditions.These environmental conditions include low and high temperatures and vacuum or high pressure. Additionally, the stacks are subjected to high stress and in some applications need to operate with a very long lifetime durability.Many of these requirements are beyond the current industry design margins for nominal terrestrial applications. In order to investigate some of the properties that will indicate the durability of such actuators and their limitations we have developed a new type of test fixture that can be easily integrated in various test chambers for simulating environmental conditions, can provide access for multiple measurements while being exposed to adjustable stress levels. We designed and built two test fixtures and these fixtures were made to be adjustable for testing stacks with different dimensions and can be easily used in small or large numbers. The properties that were measured using these fixtures include impedance, capacitance, dielectric loss factor, leakage current, displacement, breakdown voltage, and lifetime performance. The fixtures characteristics and the test capabilities are presented in this paper.

In-situ diagnostic tools for hydrogen transfer leak characterization in PEM fuel cell stacks part II: Operational applications

NASA Astrophysics Data System (ADS)

Niroumand, Amir M.; Homayouni, Hooman; DeVaal, Jake; Golnaraghi, Farid; Kjeang, Erik

2016-08-01

This paper describes a diagnostic tool for in-situ characterization of the rate and distribution of hydrogen transfer leaks in Polymer Electrolyte Membrane (PEM) fuel cell stacks. The method is based on reducing the air flow rate from a high to low value at a fixed current, while maintaining an anode overpressure. At high air flow rates, the reduction in air flow results in lower oxygen concentration in the cathode and therefore reduction in cell voltages. Once the air flow rate in each cell reaches a low value at which the cell oxygen-starves, the voltage of the corresponding cell drops to zero. However, oxygen starvation results from two processes: 1) the electrochemical oxygen reduction reaction which produces current; and 2) the chemical reaction between oxygen and the crossed over hydrogen. In this work, a diagnostic technique has been developed that accounts for the effect of the electrochemical reaction on cell voltage to identify the hydrogen leak rate and number of leaky cells in a fuel cell stack. This technique is suitable for leak characterization during fuel cell operation, as it only requires stack air flow and voltage measurements, which are readily available in an operational fuel cell system.

Queue and stack sorting algorithm optimization and performance analysis

NASA Astrophysics Data System (ADS)

Qian, Mingzhu; Wang, Xiaobao

2018-04-01

Sorting algorithm is one of the basic operation of a variety of software development, in data structures course specializes in all kinds of sort algorithm. The performance of the sorting algorithm is directly related to the efficiency of the software. A lot of excellent scientific research queue is constantly optimizing algorithm, algorithm efficiency better as far as possible, the author here further research queue combined with stacks of sorting algorithms, the algorithm is mainly used for alternating operation queue and stack storage properties, Thus avoiding the need for a large number of exchange or mobile operations in the traditional sort. Before the existing basis to continue research, improvement and optimization, the focus on the optimization of the time complexity of the proposed optimization and improvement, The experimental results show that the improved effectively, at the same time and the time complexity and space complexity of the algorithm, the stability study corresponding research. The improvement and optimization algorithm, improves the practicability.

A New, Scalable and Low Cost Multi-Channel Monitoring System for Polymer Electrolyte Fuel Cells.

PubMed

Calderón, Antonio José; González, Isaías; Calderón, Manuel; Segura, Francisca; Andújar, José Manuel

2016-03-09

In this work a new, scalable and low cost multi-channel monitoring system for Polymer Electrolyte Fuel Cells (PEFCs) has been designed, constructed and experimentally validated. This developed monitoring system performs non-intrusive voltage measurement of each individual cell of a PEFC stack and it is scalable, in the sense that it is capable to carry out measurements in stacks from 1 to 120 cells (from watts to kilowatts). The developed system comprises two main subsystems: hardware devoted to data acquisition (DAQ) and software devoted to real-time monitoring. The DAQ subsystem is based on the low-cost open-source platform Arduino and the real-time monitoring subsystem has been developed using the high-level graphical language NI LabVIEW. Such integration can be considered a novelty in scientific literature for PEFC monitoring systems. An original amplifying and multiplexing board has been designed to increase the Arduino input port availability. Data storage and real-time monitoring have been performed with an easy-to-use interface. Graphical and numerical visualization allows a continuous tracking of cell voltage. Scalability, flexibility, easy-to-use, versatility and low cost are the main features of the proposed approach. The system is described and experimental results are presented. These results demonstrate its suitability to monitor the voltage in a PEFC at cell level.

A New, Scalable and Low Cost Multi-Channel Monitoring System for Polymer Electrolyte Fuel Cells

PubMed Central

Calderón, Antonio José; González, Isaías; Calderón, Manuel; Segura, Francisca; Andújar, José Manuel

2016-01-01

In this work a new, scalable and low cost multi-channel monitoring system for Polymer Electrolyte Fuel Cells (PEFCs) has been designed, constructed and experimentally validated. This developed monitoring system performs non-intrusive voltage measurement of each individual cell of a PEFC stack and it is scalable, in the sense that it is capable to carry out measurements in stacks from 1 to 120 cells (from watts to kilowatts). The developed system comprises two main subsystems: hardware devoted to data acquisition (DAQ) and software devoted to real-time monitoring. The DAQ subsystem is based on the low-cost open-source platform Arduino and the real-time monitoring subsystem has been developed using the high-level graphical language NI LabVIEW. Such integration can be considered a novelty in scientific literature for PEFC monitoring systems. An original amplifying and multiplexing board has been designed to increase the Arduino input port availability. Data storage and real-time monitoring have been performed with an easy-to-use interface. Graphical and numerical visualization allows a continuous tracking of cell voltage. Scalability, flexibility, easy-to-use, versatility and low cost are the main features of the proposed approach. The system is described and experimental results are presented. These results demonstrate its suitability to monitor the voltage in a PEFC at cell level. PMID:27005630

Stackable air-cooled heatsinks for diode lasers

NASA Astrophysics Data System (ADS)

Crum, T. R.; Harrison, J.; Srinivasan, R.; Miller, R. L.

2007-02-01

Micro-channel heatsink assemblies made from bonding multi-layered etched metal sheets are commercially available and are often used for removing the high waste heat loads generated by the operation of diode-laser bars. Typically, a diode-laser bar is bonded onto a micro-channel (also known as mini-channel) heatsink then stacked in an array to create compact high power diode-laser sources for a multitude of applications. Under normal operation, the diode-laser waste heat is removed by passing coolant (typically de-ionized water) through the channels of the heatsink. Because of this, the heatsink internal structure, including path length and overall channel size, is dictated by the liquid coolant properties. Due to the material characteristics of these conductive heatsinks, and the necessary electrically serial stacking geometry, there are several restrictions imparted on the coolant liquid to maintain performance and lifetime. Such systems require carefully monitored and conductive limited de-ionized water, as well as require stable pH levels, and suitable particle filtration. These required coolant systems are either stand alone, or heat exchangers are typically costly and heavy restricting certain applications where minimal weight to power ratios are desired. In this paper, we will baseline the existing water cooled Spectra-Physics Monsoon TM heatsink technology utilizing compressed air, and demonstrate a novel modular stackable heatsink concept for use with gaseous fluids that, in some applications may replace the existing commercially available water-cooled heatsink technology. We will explain the various benefits of utilizing air while maintaining mechanical form factors and packing densities. We will also show thermal-fluid modeling results and predictions as well as operational performance curves for efficiency and power and compare these data to the existing commercially available technology.

Assessment of the LV-S2 & LV-S3 Stack Sampling Probe Locations for Compliance with ANSI/HPS N13.1-1999

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

Glissmeyer, John A.; Antonio, Ernest J.; Flaherty, Julia E.

2014-09-30

This document reports on a series of tests conducted to assess the proposed air sampling locations for the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Group 1-2A exhaust stacks with respect to the applicable criteria regarding the placement of an air sampling probe. The LV-C2, LV-S2, and LV-S3 exhaust stacks were tested together as a group (Test Group 1-2A). This report only covers the results of LV-S2 and LV-S3; LV-C2 will be reported on separately. Federal regulations1 require that a sampling probe be located in the exhaust stack according to the criteria established by the American National Standards Institute/Healthmore » Physics Society (ANSI/HPS) N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities. 2 These criteria address the capability of the sampling probe to extract a sample that represents the effluent stream.« less

A long-term stable power supply µDMFC stack for wireless sensor node applications

NASA Astrophysics Data System (ADS)

Wu, Zonglin; Wang, Xiaohong; Li, Xiaozhao; Xu, Manqi; Liu, Litian

2014-10-01

In this paper, a passive, air-breathing four-cell micro direct methanol fuel cell (µDMFC) stack featuring a fuel delivery structure for long-term and stable power supply is designed, fabricated and tested. The fuel is reserved in a T-shaped tank and diffuses through the porous diffusion layer to the catalyst at the anode. A peak power density of 25.7 mW cm-2 and a maximum power output of 113 mW are achieved with 3 M methanol at room temperature, and the stack can produce 60 mW of power, even though only 5% fuel remains in the reservoir. Combined with a low-input dc-dc convertor, the stack can realize a stable and optional constant voltage output from 1 V-6 V. The stack successfully powered a heavy metal sensor node for water environment monitoring 12 d continuously, with consumption of 10 mL 5 M methanol solution. As such, it is believed to be applicable for powering wireless sensor nodes.

Final Technical Report: Affordable, High-Performance, Intermediate Temperature Solid Oxide Fuel Cells

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

Blackburn, Bryan M.; Bishop, Sean; Gore, Colin

In this project, we improved the power output and voltage efficiency of our intermediate temperature solid oxide fuel cells (IT-SOFCs) with a focus on ~600 °C operation. At these temperatures and with the increased power density (i.e., fewer cells for same power output), the stack cost should be greatly reduced while extending durability. Most SOFC stacks operate at temperatures greater than 800 °C. This can greatly increase the cost of the system (stacks and BOP) as well as maintenance costs since the most common degradation mechanisms are thermally driven. Our approach uses no platinum group metal (PGM) materials and themore » lower operating temperature allows use of simple stainless steel interconnects and commercial off-the-shelf gaskets in the stack. Furthermore, for combined heating and power (CHP) applications the stack exhaust still provides “high quality” waste heat that can be recovered and used in a chiller or boiler. The anticipated performance, durability, and resulting cost improvements (< $700/kWe) will also move us closer to reaching the full potential of this technology for distributed generation (DG) and residential/commercial CHP. This includes eventual extension to cleaner, more efficient portable generators, auxiliary power units (APUs), and range extenders for transportation. The research added to the understanding of the area investigated by exploring various methods for increasing power density (Watts/square centimeter of active area in each cell) and increasing cell efficiency (increasing the open circuit voltage, or cell voltage with zero external electrical current). The results from this work demonstrated an optimized cell that had greater than 1 W/cm2 at 600 °C and greater than 1.6 W/cm2 at 650 °C. This was demonstrated in large format sizes using both 5 cm by 5 cm and 10 cm by 10 cm cells. Furthermore, this work demonstrated that high stability (no degradation over > 500 hours) can be achieved together with high performance in large format cells as large as 10 cm by 10 cm when operated at ~600 °C. The project culminated in the demonstration of a 12-cell stack using the porous anode-based SOFC technology.« less

Piezohydraulic Pump Development

NASA Technical Reports Server (NTRS)

Lynch, Christopher S.

2005-01-01

Reciprocating piston piezohydraulic pumps were developed originally under the Smart Wing Phase II program (Lynch) and later under the CHAP program (CSA, Kinetic Ceramics). These pumps focused on 10 cm scale stack actuators operating below resonance and, more recently, at resonance. A survey of commercially available linear actuators indicates that obtaining power density and specific power greater than electromagnetic linear actuators requires driving the stacks at frequencies greater than 1 KHz at high fields. In the case of 10 cm scale actuators the power supply signal conditioning becomes large and heavy and the soft PZT stack actuators generate a lot of heat due to internal losses. Reciprocation frequencies can be increased and material losses significantly decreased through use of millimeter scale single crystal stack actuators. We are presently targeting the design of pumps that utilize stacks at the 1-10 mm length scale and run at reciprocating frequencies of 20kHz or greater. This offers significant advantages over current approaches including eliminating audible noise and significantly increasing the power density and specific power of the system (including electronics). The pump currently under development will comprise an LC resonant drive of a resonant crystal and head mass operating against a resonant fluid column. Each of these resonant systems are high Q and together should produce a single high Q second order system.

A preliminary study of a miniature planar 6-cell PEMFC stack combined with a small hydrogen storage canister

NASA Astrophysics Data System (ADS)

Zhang, Xigui; Zheng, Dan; Wang, Tao; Chen, Cong; Cao, Jianyu; Yan, Jian; Wang, Wenming; Liu, Juanying; Liu, Haohan; Tian, Juan; Li, Xinxin; Yang, Hui; Xia, Baojia

The fabrication and performance evaluation of a miniature 6-cell PEMFC stack based on Micro-Electronic-Mechanical-System (MEMS) technology is presented in this paper. The stack with a planar configuration consists of 6-cells in serial interconnection by spot welding one cell anode with another cell cathode. Each cell was made by sandwiching a membrane-electrode-assembly (MEA) between two flow field plates fabricated by a classical MEMS wet etching method using silicon wafer as the original material. The plates were made electrically conductive by sputtering a Ti/Pt/Au composite metal layer on their surfaces. The 6-cells lie in the same plane with a fuel buffer/distributor as their support, which was fabricated by the MEMS silicon-glass bonding technology. A small hydrogen storage canister was used as fuel source. Operating on dry H 2 at a 40 ml min -1 flow rate and air-breathing conditions at room temperature and atmospheric pressure, the linear polarization experiment gave a measured peak power of 0.9 W at 250 mA cm -2 for the stack and average power density of 104 mW cm -2 for each cell. The results suggested that the stack has reasonable performance benefiting from an even fuel supply. But its performance tended to deteriorate with power increase, which became obvious at 600 mW. This suggests that the stack may need some power assistance, from say supercapacitors to maintain its stability when operated at higher power.

A novel pilot-scale stacked microbial fuel cell for efficient electricity generation and wastewater treatment.

PubMed

Wu, Shijia; Li, Hui; Zhou, Xuechen; Liang, Peng; Zhang, Xiaoyuan; Jiang, Yong; Huang, Xia

2016-07-01

A novel stacked microbial fuel cell (MFC) which had a total volume of 72 L with granular activated carbon (GAC) packed bed electrodes was constructed and verified to present remarkable power generation and COD removal performance due to its advantageous design of stack and electrode configuration. During the fed-batch operation period, a power density of 50.9 ± 1.7 W/m(3) and a COD removal efficiency of 97% were achieved within 48 h. Because of the differences among MFC modules in the stack, reversal current occurred in parallel circuit connection with high external resistances (>100 Ω). This reversal current consequently reduced the electrochemical performance of some MFC modules and led to a lower power density in parallel circuit connection than that in independent circuit connection. While increasing the influent COD concentrations from 200 to 800 mg/L at hydraulic retention time of 1.25 h in continuous operation mode, the power density of stacked MFC increased from 25.6 ± 2.5 to 42.1 ± 1.2 W/m(3) and the COD removal rates increased from 1.3 to 5.2 kg COD/(m(3) d). This study demonstrated that this novel MFC stack configuration coupling with GAC packed bed electrode could be a feasible strategy to effectively scale up MFC systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Exhaust-stack nozzle area and shape for individual cylinder exhaust-gas jet-propulsion system

NASA Technical Reports Server (NTRS)

Pinkel, Benjamin; Turner, Richard; Voss, Fred; Humble, Leroy V

1943-01-01

This report presents the results of an investigation conducted on the effect of exhaust-stack nozzle area, shape, and length on engine power, jet thrust, and gain in net thrust (engine propeller plus jet). Single-cylinder engine data were obtained using three straight stacks 25, 44, and 108 inches in length; an S-shaped stack, a 90 degree bend, a 180 degree bend, and a short straight stack having a closed branch faired into it. Each stack was fitted with nozzles varying in exit area from 0.91 square inch to the unrestricted area of the stack of 4.20 square inches. The engine was generally operated over a range of engine speeds from 1300 to 2100 r.p.m, inlet-manifold pressures from 22 to 30 inches of mercury absolute, and a fuel-air ratio of 0.08. The loss in engine power, the jet thrust, and the gain in net thrust are correlated in terms of several simple parameters. An example is given for determining the optimum nozzle area and the overall net thrust.

Electric utility acid fuel cell stack technology advancement

NASA Astrophysics Data System (ADS)

Congdon, J. V.; Goller, G. J.; Greising, G. J.; Obrien, J. J.; Randall, S. A.; Sandelli, G. J.; Breault, R. D.; Austin, G. W.; Bopse, S.; Coykendall, R. D.

1984-11-01

The principal effort under this program was directed at the fuel cell stack technology required to accomplish the initial feasibility demonstrations of increased cell stack operating pressures and temperatures, increased cell active area, incorporation of the ribbed substrate cell configuration at the bove conditions, and the introduction of higher performance electrocatalysts. The program results were successful with the primary accomplishments being: (1) fabrication of 10 sq ft ribbed substrate, cell components including higher performing electrocatalysts; (2) assembly of a 10 sq ft, 30-cell short stack; and (3) initial test of this stack at 120 psia and 405 F. These accomplishments demonstrate the feasibility of fabricating and handling large area cells using materials and processes that are oriented to low cost manufacture. An additional accomplishment under the program was the testing of two 3.7 sq ft short stacks at 12 psia/405 F to 5400 and 4500 hours respectively. These tests demonstrate the durability of the components and the cell stack configuration to a nominal 5000 hours at the higher pressure and temperature condition planned for the next electric utility power plant.

Electric utility acid fuel cell stack technology advancement

NASA Technical Reports Server (NTRS)

Congdon, J. V.; Goller, G. J.; Greising, G. J.; Obrien, J. J.; Randall, S. A.; Sandelli, G. J.; Breault, R. D.; Austin, G. W.; Bopse, S.; Coykendall, R. D.

1984-01-01

The principal effort under this program was directed at the fuel cell stack technology required to accomplish the initial feasibility demonstrations of increased cell stack operating pressures and temperatures, increased cell active area, incorporation of the ribbed substrate cell configuration at the bove conditions, and the introduction of higher performance electrocatalysts. The program results were successful with the primary accomplishments being: (1) fabrication of 10 sq ft ribbed substrate, cell components including higher performing electrocatalysts; (2) assembly of a 10 sq ft, 30-cell short stack; and (3) initial test of this stack at 120 psia and 405 F. These accomplishments demonstrate the feasibility of fabricating and handling large area cells using materials and processes that are oriented to low cost manufacture. An additional accomplishment under the program was the testing of two 3.7 sq ft short stacks at 12 psia/405 F to 5400 and 4500 hours respectively. These tests demonstrate the durability of the components and the cell stack configuration to a nominal 5000 hours at the higher pressure and temperature condition planned for the next electric utility power plant.

The effect of applied control strategy on the current-voltage correlation of a solid oxide fuel cell stack during dynamic operation

NASA Astrophysics Data System (ADS)

Szmyd, Janusz S.; Komatsu, Yosuke; Brus, Grzegorz; Ghigliazza, Francesco; Kimijima, Shinji; Ściążko, Anna

2014-09-01

This paper discusses the transient characteristics of the planar type SOFC cell stack, of which the standard output is 300 W. The transient response of the voltage to the manipulation of an electric current was investigated. The effects of the response and of the operating condition determined by the operating temperature of the stack were studied by mapping a current-voltage (I-V) correlation. The current-based fuel control (CBFC) was adopted for keeping the fuel utilization factor at constant while the value of the electric current was ramped at the constant rate. The present experimental study shows that the transient characteristics of the cell voltage are determined by primarily the operating temperature caused by the manipulation of the current. Particularly, the slope of the I-V curve and the overshoot found on the voltage was remarkably influenced by the operating temperature. The different values of the fuel utilization factor influence the height of the settled voltages. The CBFC has significance in determining the slope of the I-V characteristic, but the different values ofthe fuel utilization factor does not affect the slope as the operating temperature does. The CBFC essentially does not alter the amplitude of the overshoot on the voltage response, since this is dominated by the operating temperature and its change is caused by manipulating the current.

System for adding sulfur to a fuel cell stack system for improved fuel cell stability

DOEpatents

Mukerjee, Subhasish; Haltiner, Jr., Karl J; Weissman, Jeffrey G

2013-08-13

A system for adding sulfur to a reformate stream feeding a fuel cell stack, having a sulfur source for providing sulfur to the reformate stream and a metering device in fluid connection with the sulfur source and the reformate stream. The metering device injects sulfur from the sulfur source to the reformate stream at a predetermined rate, thereby providing a conditioned reformate stream to the fuel cell stack. The system provides a conditioned reformate stream having a predetermined sulfur concentration that gives an acceptable balance of minimal drop in initial power with the desired maximum stability of operation over prolonged periods for the fuel cell stack.

Design and Performance of a 1 ms High-Speed Vision Chip with 3D-Stacked 140 GOPS Column-Parallel PEs †.

PubMed

Nose, Atsushi; Yamazaki, Tomohiro; Katayama, Hironobu; Uehara, Shuji; Kobayashi, Masatsugu; Shida, Sayaka; Odahara, Masaki; Takamiya, Kenichi; Matsumoto, Shizunori; Miyashita, Leo; Watanabe, Yoshihiro; Izawa, Takashi; Muramatsu, Yoshinori; Nitta, Yoshikazu; Ishikawa, Masatoshi

2018-04-24

We have developed a high-speed vision chip using 3D stacking technology to address the increasing demand for high-speed vision chips in diverse applications. The chip comprises a 1/3.2-inch, 1.27 Mpixel, 500 fps (0.31 Mpixel, 1000 fps, 2 × 2 binning) vision chip with 3D-stacked column-parallel Analog-to-Digital Converters (ADCs) and 140 Giga Operation per Second (GOPS) programmable Single Instruction Multiple Data (SIMD) column-parallel PEs for new sensing applications. The 3D-stacked structure and column parallel processing architecture achieve high sensitivity, high resolution, and high-accuracy object positioning.

A novel approach to model the transient behavior of solid-oxide fuel cell stacks

NASA Astrophysics Data System (ADS)

Menon, Vikram; Janardhanan, Vinod M.; Tischer, Steffen; Deutschmann, Olaf

2012-09-01

This paper presents a novel approach to model the transient behavior of solid-oxide fuel cell (SOFC) stacks in two and three dimensions. A hierarchical model is developed by decoupling the temperature of the solid phase from the fluid phase. The solution of the temperature field is considered as an elliptic problem, while each channel within the stack is modeled as a marching problem. This paper presents the numerical model and cluster algorithm for coupling between the solid phase and fluid phase. For demonstration purposes, results are presented for a stack operated on pre-reformed hydrocarbon fuel. Transient response to load changes is studied by introducing step changes in cell potential and current. Furthermore, the effect of boundary conditions and stack materials on response time and internal temperature distribution is investigated.

75 FR 33391 - Amendments to the Protocol Gas Verification Program and Minimum Competency Requirements for Air...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-11

...Recent EPA gas audit results indicate that some gas cylinders used to calibrate continuous emission monitoring systems on stationary sources do not meet EPA's performance specification. Reviews of stack test reports in recent years indicate that some stack testers do not properly follow EPA test methods or do not correctly calculate test method results. Therefore, EPA is proposing to amend its Protocol Gas Verification Program (PGVP) and the minimum competency requirements for air emission testing (formerly air emission testing body requirements) to improve the accuracy of emissions data. EPA is also proposing to amend other sections of the Acid Rain Program continuous emission monitoring system regulations by adding and clarifying certain recordkeeping and reporting requirements, removing the provisions pertaining to mercury monitoring and reporting, removing certain requirements associated with a class-approved alternative monitoring system, disallowing the use of a particular quality assurance option in EPA Reference Method 7E, adding an incorporation by reference that was inadvertently left out of the January 24, 2008 final rule, and clarifying the language and applicability of certain provisions.

Extracting 5m Shorelines From Multi-Temporal Images

NASA Astrophysics Data System (ADS)

Kapadia, A.; Jordahl, K. A.; Kington, J. D., IV

2016-12-01

Planet operates the largest Earth observing constellation of satellites, collecting imagery at an unprecedented temporal resolution. While daily cadence is expected in early 2017, Planet has already imaged the majority of landmass several dozen times over the past year. The current dataset provides enough value to build and test algorithms to automatically extract information. Here we demonstrate the extraction of shorelines across California using image stacks. The method implemented uses as input an uncalibrated RGB data product and limited NIR combined with the National Land Cover Database 2011 (NLCD2011) and Shuttle Radar Topography Mission (SRTM) to extract shorelines at 5 meter resolution. In the near future these methods along with daily cadence of imagery will allow for temporal monitoring of shorelines on a global scale.

Bloch surface wave structures for high sensitivity detection and compact waveguiding

NASA Astrophysics Data System (ADS)

Khan, Muhammad Umar; Corbett, Brian

2016-01-01

Resonant propagating waves created on the surface of a dielectric multilayer stack, called Bloch surface waves (BSW), can be designed for high sensitivity monitoring of the adjacent refractive index as an alternative platform to the metal-based surface plasmon resonance (SPR) sensing. The resonant wavelength and polarization can be designed by engineering of the dielectric layers unlike the fixed resonance of SPR, while the wide bandwidth low loss of dielectrics permits sharper resonances, longer propagation lengths and thus their use in waveguiding devices. The transparency of the dielectrics allows the excitation and monitoring of surface-bound fluorescent molecules. We review the recent developments in this technology. We show the advantages that can be obtained by using high index contrast layered structures. Operating at 1550 nm wavelengths will allow the BSW sensors to be implemented in the silicon photonics platform where active waveguiding can be used in the realization of compact planar integrated circuits for multi-parameter sensing.

Real-time radon monitoring at Stromboli volcano: influence of environmental parameters on 222Rn degassing

NASA Astrophysics Data System (ADS)

Cigolini, C.; Ripepe, M.; Poggi, P.; Laiolo, M.

2008-12-01

Two real-time stations for radon monitoring are currently operative at Stromboli volcano. The 222Rn electronic dosimeters are interfaced with an electronic board connected to a radiomodem for wireless data transfer (through a directional antenna) to a receiving station at the volcano observatory (COA). Radon activity data and enviromental parameters (soil temperature and atmospheric pressure) are sampled every 15 minutes and are instantaneously elaborated and transferred via web so that they can be checked in remote. Collected time series show that there is an overall inverse correlation between radon emissions and seasonal temperature variations. Signal processing analysis show that radon emissions in sectors of diffuse degassing are modulated by tidal forces as well. In addition, radon activities recorded at the summit station, located along the summit fracture zone where the gas flux is concentrated, are positively correlated with changes in atmospheric pressure and confirm the occurrence of the 'atmospheric stack effect'. It is not excluded that this process may play an active role in modulating Stromboli explosivity.

PPC750 Performance Monitor

NASA Technical Reports Server (NTRS)

Meyer, Donald; Uchenik, Igor

2007-01-01

The PPC750 Performance Monitor (Perfmon) is a computer program that helps the user to assess the performance characteristics of application programs running under the Wind River VxWorks real-time operating system on a PPC750 computer. Perfmon generates a user-friendly interface and collects performance data by use of performance registers provided by the PPC750 architecture. It processes and presents run-time statistics on a per-task basis over a repeating time interval (typically, several seconds or minutes) specified by the user. When the Perfmon software module is loaded with the user s software modules, it is available for use through Perfmon commands, without any modification of the user s code and at negligible performance penalty. Per-task run-time performance data made available by Perfmon include percentage time, number of instructions executed per unit time, dispatch ratio, stack high water mark, and level-1 instruction and data cache miss rates. The performance data are written to a file specified by the user or to the serial port of the computer

Field studies: Test method for on-line continuous measurement of total hydrocarbons (THC) and non-methane hydrocarbons (NMHC) in stack gas

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

Hsiao, H.H.; Lai, C.C.; Chu, H.W.

A new method for on-line monitoring of total hydrocarbons and non-methane hydrocarbons in stack gas simultaneously was developed in this study. Based on the principle of on-line GC/FID, the method was developed and can be considered as a new modification of the Method 25 and 25A of US EPA. Major advantages of the method included (1) capability of distinguishing methane as Method 25; (2) near-real-time results; (3) broad species coverage; (4) monitoring methane in straightforward manner; (5) low operation and maintenance costs. In the proposed method, test samples were continuously pumped from detection sources and loaded with a two-loop samplingmore » valve. The samples were then injected into two GC columns-empty and molecular sieve columns. The empty column was used for detection of THC, and the molecular sieve column was for methane. The detector in this GC was FID. NMHC concentration was obtained by subtracting methane from THC. The tests were carried out to measure the THC and methane in waste gas in various industries, including surface coating, semiconductor manufacturing, synthetic leather industries. Recovery rates of THC in the samples were between 86% to 114% for about 100 m of transfer line of samples. For the standard gas, the recovery rate was about 101%, 6.6 % of measurement precision, and 88%--114% of accuracy. The results showed the promising and reliable measurement of the test method for THC and methane in waste gas.« less

Life Sciences Laboratory 2 Fan Exhaust Mixing Study

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

Flaherty, Julia E.; Antonio, Ernest J.

An SF 6 tracer release was performed in the LSL-II ventilation stack over the weekend of March 5, 2016. The primary purpose of this study was to experimentally determine the gaseous concentration of material from a fume hood to the fan outlet, as well as at typical worker locations, to gain an understanding of potential worker exposures impacts. Five different fan operating configurations were utilized to ensure that the full spectrum of historical operating configurations was addressed. Some summary points from this study include: •Relatively high concentrations were observed within the stack area. –Between 50 and 100% of the exhaustmore » concentration may be observed within the stack. •Background concentrations were observed outside the stack area. –Workers outside the stack itself, but on the roof, are unlikely to be impacted by the exhaust. •Elevated concentrations on the order of 25% of the exhaust concentrations were observed within the Penthouse. •Transport time from a laboratory fume hood to the exhaust fan is within one to two minutes. •Penthouse concentrations climb from background levels to steady state over 15+ minutes. •Wind speed and wind direction did not play a significant role in the test outcomes. –A slight bias in the concentration distribution may be discernable based on wind speed and direction. •When both fans are operating, material from fume hoods on the east side preferentially flow through the east fan, while material from fume hoods on the west side preferentially flow through the west fan. This effectively doubles the concentration at that fan. This mixing study will inform other study components to develop a more complete picture of the worker potential exposure from LSL-II Rooftop activities. Estimating the mean concentration in the stack from chemical inventories and fume hood emissions for both current and historical laboratory activities is a separate effort. These estimates of mean ventilation concentrations will utilize this mixing study to estimate the potential exposure to workers working in and around the LSL-II stack.« less

Convolutional neural network-based malaria diagnosis from focus stack of blood smear images acquired using custom-built slide scanner.

PubMed

Gopakumar, Gopalakrishna Pillai; Swetha, Murali; Sai Siva, Gorthi; Sai Subrahmanyam, Gorthi R K

2018-03-01

The present paper introduces a focus stacking-based approach for automated quantitative detection of Plasmodium falciparum malaria from blood smear. For the detection, a custom designed convolutional neural network (CNN) operating on focus stack of images is used. The cell counting problem is addressed as the segmentation problem and we propose a 2-level segmentation strategy. Use of CNN operating on focus stack for the detection of malaria is first of its kind, and it not only improved the detection accuracy (both in terms of sensitivity [97.06%] and specificity [98.50%]) but also favored the processing on cell patches and avoided the need for hand-engineered features. The slide images are acquired with a custom-built portable slide scanner made from low-cost, off-the-shelf components and is suitable for point-of-care diagnostics. The proposed approach of employing sophisticated algorithmic processing together with inexpensive instrumentation can potentially benefit clinicians to enable malaria diagnosis. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Interferometer design and controls for pulse stacking in high power fiber lasers

NASA Astrophysics Data System (ADS)

Wilcox, Russell; Yang, Yawei; Dahlen, Dar; Xu, Yilun; Huang, Gang; Qiang, Du; Doolittle, Lawrence; Byrd, John; Leemans, Wim; Ruppe, John; Zhou, Tong; Sheikhsofla, Morteza; Nees, John; Galvanauskas, Almantas; Dawson, Jay; Chen, Diana; Pax, Paul

2017-03-01

In order to develop a design for a laser-plasma accelerator (LPA) driver, we demonstrate key technologies that enable fiber lasers to produce high energy, ultrafast pulses. These technologies must be scalable, and operate in the presence of thermal drift, acoustic noise, and other perturbations typical of an operating system. We show that coherent pulse stacking (CPS), which requires optical interferometers, can be made robust by image-relaying, multipass optical cavities, and by optical phase control schemes that sense pulse train amplitudes from each cavity. A four-stage pulse stacking system using image-relaying cavities is controlled for 14 hours using a pulse-pattern sensing algorithm. For coherent addition of simultaneous ultrafast pulses, we introduce a new scheme using diffractive optics, and show experimentally that four pulses can be added while a preserving pulse width of 128 fs.

40 CFR 62.14442 - What must my inspection include?

Code of Federal Regulations, 2014 CFR

2014-07-01

...; (15) Inspect bypass stack components; (16) Ensure proper calibration of thermocouples, sorbent feed... calibration of thermocouples, sorbent feed systems and any other monitoring equipment; and (3) Include...

40 CFR 62.14442 - What must my inspection include?

Code of Federal Regulations, 2013 CFR

2013-07-01

...; (15) Inspect bypass stack components; (16) Ensure proper calibration of thermocouples, sorbent feed... calibration of thermocouples, sorbent feed systems and any other monitoring equipment; and (3) Include...

40 CFR 265.377 - Monitoring and inspections.

Code of Federal Regulations, 2010 CFR

2010-07-01

... steady state or other appropriate thermal treatment conditions must be made immediately either... process flow and level controls. (2) The stack plume (emissions), where present, must be observed visually...

Fuel Cell Stack Testing and Durability in Support of Ion Tiger UAV

DTIC Science & Technology

2010-06-02

N00173-08-2-C008 specified. In June 2008, the first M250 stack 242503 data were incorporated into the PEMFC system model as a look-up data table...control and operational model which implements the operational strategy by controlling the power from the PEMFC systems and battery pack for a total...Outputs PEMFC System Outputs <~~>*<*,yrx**i~yc*r»>r-’+**^^ FCS_P«wi_Dwn«l (W) 10 15 20 25 BfOfumon PCM« Cwnind Wi ) 5 10 15

The `advanced DIR-MCFC development' project, an overview

NASA Astrophysics Data System (ADS)

Kortbeek, P. J.; Ottervanger, R.

An overview is given of the approach and mid-term status of the joint European `Advanced DIR-MCFC Development' project, in which BCN, BG plc, GDF, ECN, Stork, Schelde and Sydkraft co-operate. Hospitals are identified as an attractive initial market for cogeneration direct internal reforming-molten carbonate fuel cell (DIR-MCFC) systems in the size of 400 kWe. Innovative system and stack design concepts are being developed for this application. The `SMARTER' system, based on DIR stacks, combines high electric efficiency and a wide operational window with optimal system simplicity and low cost.

SAFT nickel hydrogen cell cycling status

NASA Technical Reports Server (NTRS)

Borthomieu, Yannick; Duquesne, Didier

1994-01-01

An overview of the NiH2 cell development is given. The NiH2 SAFT system is an electrochemical (single or dual) stack (IPV). The stack is mounted in an hydroformed Inconel 718 vessel operating at high pressure, equipped with 'rabbit ears' ceramic brazed electrical feedthroughs. The cell design is described: positive electrode, negative electrode, and stack configuration. Overviews of low earth orbit and geostationary earth orbit cyclings are provided. DPA results are also provided. The cycling and DPA results demonstrate that SAFT NiH2 is characterized by high reliability and very stable performances.

Multimode resistive switching in nanoscale hafnium oxide stack as studied by atomic force microscopy

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

Hou, Y., E-mail: houyi@pku.edu.cn, E-mail: lfliu@pku.edu.cn; IMEC, Kapeldreef 75, B-3001 Heverlee; Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Heverlee

2016-07-11

The nanoscale resistive switching in hafnium oxide stack is investigated by the conductive atomic force microscopy (C-AFM). The initial oxide stack is insulating and electrical stress from the C-AFM tip induces nanometric conductive filaments. Multimode resistive switching can be observed in consecutive operation cycles at one spot. The different modes are interpreted in the framework of a low defect quantum point contact theory. The model implies that the optimization of the conductive filament active region is crucial for the future application of nanoscale resistive switching devices.

A thermodynamic approach for selecting operating conditions in the design of reversible solid oxide cell energy systems

NASA Astrophysics Data System (ADS)

Wendel, Christopher H.; Kazempoor, Pejman; Braun, Robert J.

2016-01-01

Reversible solid oxide cell (ReSOC) systems are being increasingly considered for electrical energy storage, although much work remains before they can be realized, including cell materials development and system design optimization. These systems store electricity by generating a synthetic fuel in electrolysis mode and subsequently recover electricity by electrochemically oxidizing the stored fuel in fuel cell mode. System thermal management is improved by promoting methane synthesis internal to the ReSOC stack. Within this strategy, the cell-stack operating conditions are highly impactful on system performance and optimizing these parameters to suit both operating modes is critical to achieving high roundtrip efficiency. Preliminary analysis shows the thermoneutral voltage to be a useful parameter for analyzing ReSOC systems and the focus of this study is to quantitatively examine how it is affected by ReSOC operating conditions. The results reveal that the thermoneutral voltage is generally reduced by increased pressure, and reductions in temperature, fuel utilization, and hydrogen-to-carbon ratio. Based on the thermodynamic analysis, many different combinations of these operating conditions are expected to promote efficient energy storage. Pressurized systems can achieve high efficiency at higher temperature and fuel utilization, while non-pressurized systems may require lower stack temperature and suffer from reduced energy density.

In-ground operation of Geothermic Fuel Cells for unconventional oil and gas recovery

NASA Astrophysics Data System (ADS)

Sullivan, Neal; Anyenya, Gladys; Haun, Buddy; Daubenspeck, Mark; Bonadies, Joseph; Kerr, Rick; Fischer, Bernhard; Wright, Adam; Jones, Gerald; Li, Robert; Wall, Mark; Forbes, Alan; Savage, Marshall

2016-01-01

This paper presents operating and performance characteristics of a nine-stack solid-oxide fuel cell combined-heat-and-power system. Integrated with a natural-gas fuel processor, air compressor, reactant-gas preheater, and diagnostics and control equipment, the system is designed for use in unconventional oil-and-gas processing. Termed a ;Geothermic Fuel Cell; (GFC), the heat liberated by the fuel cell during electricity generation is harnessed to process oil shale into high-quality crude oil and natural gas. The 1.5-kWe SOFC stacks are packaged within three-stack GFC modules. Three GFC modules are mechanically and electrically coupled to a reactant-gas preheater and installed within the earth. During operation, significant heat is conducted from the Geothermic Fuel Cell to the surrounding geology. The complete system was continuously operated on hydrogen and natural-gas fuels for ∼600 h. A quasi-steady operating point was established to favor heat generation (29.1 kWth) over electricity production (4.4 kWe). Thermodynamic analysis reveals a combined-heat-and-power efficiency of 55% at this condition. Heat flux to the geology averaged 3.2 kW m-1 across the 9-m length of the Geothermic Fuel Cell-preheater assembly. System performance is reviewed; some suggestions for improvement are proposed.

Enabling IPv6 at FZU - WLCG Tier2 in Prague

NASA Astrophysics Data System (ADS)

Kouba, Tomáš; Chudoba, Jiří; Eliáš, Marek

2014-06-01

The usage of the new IPv6 protocol in production is becoming reality in the HEP community and the Computing Centre of the Institute of Physics in Prague participates in many IPv6 related activities. Our contribution presents experience with monitoring in HEPiX distributed IPv6 testbed which includes 11 remote sites. We use Nagios to check availability of services and Smokeping for monitoring the network latency. Since it is not always trivial to setup DNS in a dual stack environment properly, we developed a Nagios plugin for checking whether a domain name is resolvable when using only IP protocol version 6 and only version 4. We will also present local area network monitoring and tuning related to IPv6 performance. One of the most important software for a grid site is a batch system for a job execution. We will present our experience with configuring and running Torque batch system in a dual stack environment. We also discuss the steps needed to run VO specific jobs in our IPv6 testbed.

Development of Anode-Supported Single Cells and Small Stacks for Intermediate Temperature Sofc at Kepri

NASA Astrophysics Data System (ADS)

Yoo, Y.-S.; Park, J.-W.; Park, J.-K.; Lim, H.-C.; Oh, J.-M.; Bae, J.-M.

Recent results on intermediate temperature-operating solid oxide fuel cells (IT-SOFC) are mainly focused on getting the higher performance of single cell at lower operating temperature, especially using planar type. We have started a project to develop 1 kW-class SOFC system for Residential Power Generation(RPG) application. For a 1 kW-class SOFC stack that can be operated at intermediate temperatures, we have developed anode-supported, planar type SOFC to have advantages for commercialization of SOFCs considering mass production and using cost-effective interconnects such as ferritic stainless steels. At higher temperature, performance of SOFC can be increased due to higher electrochemical activity of electrodes and lower ohmic losses, but the surface of metallic interconnects at cathode side is rapidly oxidized into resistive oxide scale. For efficient operation of SOFC at reduced temperature at, firstly we have developed alternative cathode materials of LSCF instead of LSM to get higher performance of electrodes, and secondly introduced functional-layered structure at anode side. The I-V and AC impedance characteristics of improved single cells and small stacks were evaluated at intermediate temperatures (650°C and 750°C) using hydrogen gas as a fuel.

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

Shoup, R.W.; Long, F.; Martin, T.H.

Sandia is developing PBFA-Z, a 20-MA driver for z-pinch experiments by replacing the water lines, insulator stack, and MITLs on PBFA II with new hardware. The design of the vacuum insulator stack was dictated by the drive voltage, the electric field stress and grading requirements, the water line and MITL interface requirements, and the machine operations and maintenance requirements. The insulator stack will consist of four separate modules, each of a different design because of different voltage drive and hardware interface requirements. The shape of the components in each module, i.e., grading rings, insulator rings, flux excluders, anode and cathodemore » conductors, and the design of the water line and MITL interfaces, were optimized by using the electrostatic analysis codes, ELECTRO and JASON. The time dependent performance of the insulator stack was evaluated using IVORY, a 2-D PIC code. This paper will describe the insulator stack design and present the results of the ELECTRO and IVORY analyses.« less

Three-dimensional computational fluid dynamics modelling and experimental validation of the Jülich Mark-F solid oxide fuel cell stack

NASA Astrophysics Data System (ADS)

Nishida, R. T.; Beale, S. B.; Pharoah, J. G.; de Haart, L. G. J.; Blum, L.

2018-01-01

This work is among the first where the results of an extensive experimental research programme are compared to performance calculations of a comprehensive computational fluid dynamics model for a solid oxide fuel cell stack. The model, which combines electrochemical reactions with momentum, heat, and mass transport, is used to obtain results for an established industrial-scale fuel cell stack design with complex manifolds. To validate the model, comparisons with experimentally gathered voltage and temperature data are made for the Jülich Mark-F, 18-cell stack operating in a test furnace. Good agreement is obtained between the model and experiment results for cell voltages and temperature distributions, confirming the validity of the computational methodology for stack design. The transient effects during ramp up of current in the experiment may explain a lower average voltage than model predictions for the power curve.

Hardware simulation of fuel cell/gas turbine hybrids

NASA Astrophysics Data System (ADS)

Smith, Thomas Paul

Hybrid solid oxide fuel cell/gas turbine (SOFC/GT) systems offer high efficiency power generation, but face numerous integration and operability challenges. This dissertation addresses the application of hardware-in-the-loop simulation (HILS) to explore the performance of a solid oxide fuel cell stack and gas turbine when combined into a hybrid system. Specifically, this project entailed developing and demonstrating a methodology for coupling a numerical SOFC subsystem model with a gas turbine that has been modified with supplemental process flow and control paths to mimic a hybrid system. This HILS approach was implemented with the U.S. Department of Energy Hybrid Performance Project (HyPer) located at the National Energy Technology Laboratory. By utilizing HILS the facility provides a cost effective and capable platform for characterizing the response of hybrid systems to dynamic variations in operating conditions. HILS of a hybrid system was accomplished by first interfacing a numerical model with operating gas turbine hardware. The real-time SOFC stack model responds to operating turbine flow conditions in order to predict the level of thermal effluent from the SOFC stack. This simulated level of heating then dynamically sets the turbine's "firing" rate to reflect the stack output heat rate. Second, a high-speed computer system with data acquisition capabilities was integrated with the existing controls and sensors of the turbine facility. In the future, this will allow for the utilization of high-fidelity fuel cell models that infer cell performance parameters while still computing the simulation in real-time. Once the integration of the numeric and the hardware simulation components was completed, HILS experiments were conducted to evaluate hybrid system performance. The testing identified non-intuitive transient responses arising from the large thermal capacitance of the stack that are inherent to hybrid systems. Furthermore, the tests demonstrated the capabilities of HILS as a research tool for investigating the dynamic behavior of SOFC/GT hybrid power generation systems.

Next Generation Robust Low Noise Seismometer for Nuclear Monitoring

DTIC Science & Technology

2008-09-01

of four fine platinum mesh electrodes, two anodes, and two cathodes, separated by thin polymer mesh or laser-perforated mica spacers. The stack is...cell (Abramocvich and Daragan, 1992-94): ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ −− )exp(1 00 kT qU l eSDc =I (6) 2008 Monitoring Research Review: Ground-Based

Optical monitoring of rugate filters

NASA Astrophysics Data System (ADS)

Lappschies, Marc; Görtz, Björn; Ristau, Detlev

2005-09-01

Rugate filters have a high potential for solving specific design problems in many applications of modern optics and lighting technology. However, the exact manufacture of these gradual layer systems is still a challenge which could not be solved completely until today. One of the prominent approaches for the production of rugate filters is based on independent quartz crystal devices measuring the rate of the different coating materials. As an alternative, optical broadband monitoring has been already qualified for controlling the deposition of complicated non quarterwave stacks. In the present study, promising results of this deposition control concept as a direct monitoring of rugate filters will be presented. In a first attempt, the continuous change of refractive indices in the graded layers was transformed to a set of discrete homogeneous sub-layers with thicknesses values of around 5 nm. These discrete layers are realized by defined mixtures of two materials. A data base for the dispersion behavior was created for the different mixing ratios and is employed for the production of such quasi-rugate filters. The optical monitor is operated in the routine mode determining the switching points of the layers. Selected examples will be presented for quasi rugate coatings produced by ion beam sputtering from a movable zone target. Different designs will be discussed considering production problems as well as achievable optical properties.

MMS Spacecraft Uncrated & Moved

NASA Image and Video Library

2014-10-29

Workers prepare a payload dolly for the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, during uncrating operations in the Building 2 south encapsulation bay at the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. The MMS upper stack, mini-stack number 2, is scheduled to arrive in about two weeks. MMS is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration and turbulence. Launch aboard a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station is targeted for March 12, 2015.

MMS Spacecraft Uncrated & Moved

NASA Image and Video Library

2014-10-29

Two of the observatories, the lower stack, mini-stack number 1, for NASA's Magnetospheric Multiscale Observatory, or MMS, glides toward a payload dolly during uncrating operations in the Building 2 south encapsulation bay at the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. The MMS upper stack, mini-stack number 2, is scheduled to arrive in about two weeks. MMS is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration and turbulence. Launch aboard a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station is targeted for March 12, 2015.

MMS Spacecraft Uncrated & Moved

NASA Image and Video Library

2014-10-29

A crane is lowered toward the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, during uncrating operations in the Building 2 south encapsulation bay at the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. The MMS upper stack, mini-stack number 2, is scheduled to arrive in about two weeks. MMS is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration and turbulence. Launch aboard a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station is targeted for March 12, 2015.

Hanford Site radionuclide national emission standards for hazardous ari pollutants registered and and unregistered stack (powered exhaust) source assessment

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

Davis, W.E.

1995-12-01

On February 3, 1993, US DOE Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Div. of US EPA, Region X. The compliance order requires the Richland Operations Office to evaluate all radionuclide emission points at the Hanford site to determine which are subject to the continuous emission measurement requirements in Title 40, Code of Federal Regulations (CFR), Part 61, Subpart H, and to continuously measure radionuclide emissions in accordance with 40 CFR 61.93. The Information Request required The provision of a written compliance plan to meet the requirements of themore » compliance order. A compliance plan was submitted to EPA, Region X, on April 30, 1993. It set as one of the milestones, the complete assessment of the Hanford Site 84 stacks registered with the Washington State Department of Health, by December 17, 1993. This milestone was accomplished. The compliance plan also called for reaching a Federal Facility Compliance Agreement; this was reached on February 7, 1994, between DOE Richland Operations and EPA, Region X. The milestone to assess the unregistered stacks (powered exhaust) by August 31, 1994, was met. This update presents assessments for 72 registered and 22 unregistered stacks with potential emissions > 0.1 mrem/yr.« less

A SCREENING LEVEL RISK ASSESSMENT OF THE INDIRECT IMPACTS FROM THE COLUMBUS WASTE TO ENERGY FACILITY IN COLUMBUS, OHIO

EPA Science Inventory

Testing for emissions of dioxins from the stack of the Columbus, Ohio Waste to Energy (WTE) municipal solid waste combustion facility in 1992 implied that dioxin concentrations in stack gas averaged 328 ng TEQ/m3. The incinerator had been in operation since the early 1980s. In ...

Analytical Tools for Cloudscope Ice Measurement

NASA Technical Reports Server (NTRS)

Arnott, W. Patrick

1998-01-01

The cloudscope is a ground or aircraft instrument for viewing ice crystals impacted on a sapphire window. It is essentially a simple optical microscope with an attached compact CCD video camera whose output is recorded on a Hi-8 mm video cassette recorder equipped with digital time and date recording capability. In aircraft operation the window is at a stagnation point of the flow so adiabatic compression heats the window to sublimate the ice crystals so that later impacting crystals can be imaged as well. A film heater is used for ground based operation to provide sublimation, and it can also be used to provide extra heat for aircraft operation. The compact video camera can be focused manually by the operator, and a beam splitter - miniature bulb combination provide illumination for night operation. Several shutter speeds are available to accommodate daytime illumination conditions by direct sunlight. The video images can be directly used to qualitatively assess the crystal content of cirrus clouds and contrails. Quantitative size spectra are obtained with the tools described in this report. Selected portions of the video images are digitized using a PCI bus frame grabber to form a short movie segment or stack using NIH (National Institute of Health) Image software with custom macros developed at DRI. The stack can be Fourier transform filtered with custom, easy to design filters to reduce most objectionable video artifacts. Particle quantification of each slice of the stack is performed using digital image analysis. Data recorded for each particle include particle number and centroid, frame number in the stack, particle area, perimeter, equivalent ellipse maximum and minimum radii, ellipse angle, and pixel number. Each valid particle in the stack is stamped with a unique number. This output can be used to obtain a semiquantitative appreciation of the crystal content. The particle information becomes the raw input for a subsequent program (FORTRAN) that synthesizes each slice and separates the new from the sublimating particles. The new particle information is used to generate quantitative particle concentration, area, and mass size spectra along with total concentration, solar extinction coefficient, and ice water content. This program directly creates output in html format for viewing with a web browser.

Four-flap Breast Reconstruction: Bilateral Stacked DIEP and PAP Flaps

PubMed Central

Mayo, James L.; Allen, Robert J.

2015-01-01

Background: In cases of bilateral breast reconstruction when the deep inferior epigastric perforator (DIEP) free flap alone does not provide sufficient volume for body-specific reconstruction, stacking each DIEP flap with a second free flap will deliver added volume and maintain a purely autologous reconstruction. Stacking the profunda artery perforator (PAP) flap with the DIEP flap offers favorable aesthetics and ideal operative efficiency. We present the indications, technique, and outcomes of our experience with 4-flap breast reconstruction using stacked DIEP/PAP flaps. Methods: The authors performed 4-flap DIEP/PAP breast reconstruction in 20 patients who required bilateral reconstruction without adequate single donor flap volume. The timing of reconstruction, average mastectomy/flap weights, and operative time are reported. Complications reviewed include fat necrosis, dehiscence, hematoma, seroma, mastectomy flap necrosis, and flap loss. Results: Twenty patients underwent 4-flap DIEP/PAP breast reconstruction. Surgical time averaged 7 hours and 20 minutes. The primary recipient vessels were the antegrade and retrograde internal mammary vessels. No flap losses occurred. Complications included 1 hematoma, 1 incidence of arterial and venous thrombosis successfully treated with anastomotic revision, 1 incidence of thigh donor site dehiscence, and 3 episodes of minor mastectomy skin flap necrosis. Conclusions: Four-flap breast reconstruction is a favorable autologous reconstructive option for patients requiring bilateral reconstruction without adequate single donor flap volume. Stacking DIEP/PAP flaps as described is both safe and efficient. Furthermore, this combination provides superior aesthetics mirroring the natural geometry of the breast. Bilateral stacked DIEP/PAP flaps represent our first choice for breast reconstruction in this patient population. PMID:26090273

Model-based development of low-level control strategies for transient operation of solid oxide fuel cell systems

NASA Astrophysics Data System (ADS)

Sorrentino, Marco; Pianese, Cesare

The exploitation of an SOFC-system model to define and test control and energy management strategies is presented. Such a work is motivated by the increasing interest paid to SOFC technology by industries and governments due to its highly appealing potentialities in terms of energy savings, fuel flexibility, cogeneration, low-pollution and low-noise operation. The core part of the model is the SOFC stack, surrounded by a number of auxiliary devices, i.e. air compressor, regulating pressure valves, heat exchangers, pre-reformer and post-burner. Due to the slow thermal dynamics of SOFCs, a set of three lumped-capacity models describes the dynamic response of fuel cell and heat exchangers to any operation change. The dynamic model was used to develop low-level control strategies aimed at guaranteeing targeted performance while keeping stack temperature derivative within safe limits to reduce stack degradation due to thermal stresses. Control strategies for both cold-start and warmed-up operations were implemented by combining feedforward and feedback approaches. Particularly, the main cold-start control action relies on the precise regulation of methane flow towards anode and post-burner via by-pass valves; this strategy is combined with a cathode air-flow adjustment to have a tight control of both stack temperature gradient and warm-up time. Results are presented to show the potentialities of the proposed model-based approach to: (i) serve as a support to control strategies development and (ii) solve the trade-off between fast SOFC cold-start and avoidance of thermal-stress caused damages.

Energy-Sensitive Ion- and Cathode-Luminescent Radiation-Beam Monitors Based on Multilayer Thin-Film Designs.

PubMed

Gil-Rostra, Jorge; Ferrer, Francisco J; Espinós, Juan Pedro; González-Elipe, Agustín R; Yubero, Francisco

2017-05-17

A multilayer luminescent design concept is presented to develop energy-sensitive radiation-beam monitors on the basis of colorimetric analysis. Each luminescent layer within the stack consists of rare-earth-doped transparent oxides of optical quality and a characteristic luminescent emission under excitation with electron or ion beams. For a given type of particle beam (electron, protons, α particles, etc.), its penetration depth and therefore its energy loss at a particular buried layer within the multilayer stack depend on the energy of the initial beam. The intensity of the luminescent response of each layer is proportional to the energy deposited by the radiation beam within the layer, so characteristic color emission will be achieved if different phosphors are considered in the layers of the luminescent stack. Phosphor doping, emission efficiency, layer thickness, and multilayer structure design are key parameters relevant to achieving a broad colorimetric response. Two case examples are designed and fabricated to illustrate the capabilities of these new types of detector to evaluate the kinetic energy of either electron beams of a few kilo-electron volts or α particles of a few mega-electron volts.

Vapor and liquid optical monitoring with sculptured Bragg microcavities

NASA Astrophysics Data System (ADS)

Oliva-Ramirez, Manuel; Gil-Rostra, Jorge; López-Santos, Maria Carmen; González-Elipe, Agustín R.; Yubero, Francisco

2017-10-01

Sculptured porous Bragg microcavities (BMs) formed by the successive stacking of columnar SiO2 and TiO2 thin films with a zig-zag columnar microstructure are prepared by glancing angle deposition. These BMs act as wavelength-dependent optical retarders. This optical behavior is attributed to a self-structuration of the stacked layers involving the lateral association of nanocolumns in the direction perpendicular to the main flux of particles during the multilayer film growth, as observed by focused ion beam scanning electron microscopy. The retardance of these optically active BMs can be modulated by dynamic infiltration of their open porosity with vapors, liquids, or solutions with different refractive indices. The tunable birefringence of these nanostructured photonic systems has been successfully simulated with a simple model that assumes that each layer within the BMs stack has uniaxial birefringence. The sculptured BMs have been incorporated as microfluidic chips for optical transduction for label-free vapor and liquid sensing. Several examples of the detection performance of these chips, working either in reflection or transmission configuration, for the optical monitoring of vapor and liquids of different refractive indices and aqueous solutions of glucose flowing through the microfluidic chips are described.

Energy-efficient process-stacking multiplexing access for 60-GHz mm-wave wireless personal area networks.

PubMed

Estevez, Claudio; Kailas, Aravind

2012-01-01

Millimeter-wave technology shows high potential for future wireless personal area networks, reaching over 1 Gbps transmissions using simple modulation techniques. Current specifications consider dividing the spectrum into effortlessly separable spectrum ranges. These low requirements open a research area in time and space multiplexing techniques for millimeter-waves. In this work a process-stacking multiplexing access algorithm is designed for single channel operation. The concept is intuitive, but its implementation is not trivial. The key to stacking single channel events is to operate while simultaneously obtaining and handling a-posteriori time-frame information of scheduled events. This information is used to shift a global time pointer that the wireless access point manages and uses to synchronize all serviced nodes. The performance of the proposed multiplexing access technique is lower bounded by the performance of legacy TDMA and can significantly improve the effective throughput. Work is validated by simulation results.

Technology development for phosphoric acid fuel cell powerplant, phase 2

NASA Technical Reports Server (NTRS)

Christner, L.

1981-01-01

The development of materials, cell components, and reformers for on site integrated energy systems is described. Progress includes: (1) heat-treatment of 25 sq cm, 350 sq cm and 1200 sq cm cell test hardware was accomplished. Performance of fuel cells is improved by using this material; (2) electrochemical and chemical corrosion rates of heat-treated and as-molded graphite/phenolic resin composites in phosphoric acid were determined; (3) three cell, 5 in. x 15 in. stacks operated for up to 10,000 hours and 12 in. x 17 in. five cell stacks were tested for 5,000 hours; (4) a three cell 5 in. x 15 in. stack with 0.12 mg Pt/sq cm anodes and 0.25 mg Pt/sq cm cathodes was operated for 4,500 hours; and (5) an ERC proprietary high bubble pressure matrix, MAT-1, was tested for up to 10,000 hours.

Pumpless thermal management of water-cooled high-temperature proton exchange membrane fuel cells

NASA Astrophysics Data System (ADS)

Song, Tae-Won; Choi, Kyoung-Hwan; Kim, Ji-Rae; Yi, Jung S.

2011-05-01

Proton exchange membrane fuel cells (PEMFCs) have been considered for combined heat and power (CHP) applications, but cost reduction has remained an issue for commercialization. Among various types of PEMFC, the high-temperature (HT) PEMFC is gaining more attention due to the simplicity of the system, that will make the total system cost lower. A pumpless cooling concept is introduced to reduce the number of components of a HT PEMFC system even further and also decrease the parasitic power required for operating the system. In this concept, water is used as the coolant, and the buoyancy force caused by the density difference between vapour and liquid when operated above boiling temperate is utilized to circulate the coolant between the stack and the cooling device. In this study, the basic parameters required to design the cooling device are discussed, and the stable operation of the HT PEMFC stack in both the steady-state and during transient periods is demonstrated. It found that the pumpless cooling method provides more uniform temperature distribution within the stack, regardless of the direction of coolant flow.

Control Code for Bearingless Switched-Reluctance Motor

NASA Technical Reports Server (NTRS)

Morrison, Carlos R.

2007-01-01

A computer program has been devised for controlling a machine that is an integral combination of magnetic bearings and a switched-reluctance motor. The motor contains an eight-pole stator and a hybrid rotor, which has both (1) a circular lamination stack for levitation and (2) a six-pole lamination stack for rotation. The program computes drive and levitation currents for the stator windings with real-time feedback control. During normal operation, two of the four pairs of opposing stator poles (each pair at right angles to the other pair) levitate the rotor. The remaining two pairs of stator poles exert torque on the six-pole rotor lamination stack to produce rotation. This version is executable in a control-loop time of 40 s on a Pentium (or equivalent) processor that operates at a clock speed of 400 MHz. The program can be expanded, by addition of logic blocks, to enable control of position along additional axes. The code enables adjustment of operational parameters (e.g., motor speed and stiffness, and damping parameters of magnetic bearings) through computer keyboard key presses.

Dynamic modeling, experimental evaluation, optimal design and control of integrated fuel cell system and hybrid energy systems for building demands

NASA Astrophysics Data System (ADS)

Nguyen, Gia Luong Huu

Fuel cells can produce electricity with high efficiency, low pollutants, and low noise. With the advent of fuel cell technologies, fuel cell systems have since been demonstrated as reliable power generators with power outputs from a few watts to a few megawatts. With proper equipment, fuel cell systems can produce heating and cooling, thus increased its overall efficiency. To increase the acceptance from electrical utilities and building owners, fuel cell systems must operate more dynamically and integrate well with renewable energy resources. This research studies the dynamic performance of fuel cells and the integration of fuel cells with other equipment in three levels: (i) the fuel cell stack operating on hydrogen and reformate gases, (ii) the fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit, and (iii) the hybrid energy system consisting of photovoltaic panels, fuel cell system, and energy storage. In the first part, this research studied the steady-state and dynamic performance of a high temperature PEM fuel cell stack. Collaborators at Aalborg University (Aalborg, Denmark) conducted experiments on a high temperature PEM fuel cell short stack at steady-state and transients. Along with the experimental activities, this research developed a first-principles dynamic model of a fuel cell stack. The dynamic model developed in this research was compared to the experimental results when operating on different reformate concentrations. Finally, the dynamic performance of the fuel cell stack for a rapid increase and rapid decrease in power was evaluated. The dynamic model well predicted the performance of the well-performing cells in the experimental fuel cell stack. The second part of the research studied the dynamic response of a high temperature PEM fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit with high thermal integration. After verifying the model performance with the obtained experimental data, the research studied the control of airflow to regulate the temperature of reactors within the fuel processor. The dynamic model provided a platform to test the dynamic response for different control gains. With sufficient sensing and appropriate control, a rapid response to maintain the temperature of the reactor despite an increase in power was possible. The third part of the research studied the use of a fuel cell in conjunction with photovoltaic panels, and energy storage to provide electricity for buildings. This research developed an optimization framework to determine the size of each device in the hybrid energy system to satisfy the electrical demands of buildings and yield the lowest cost. The advantage of having the fuel cell with photovoltaic and energy storage was the ability to operate the fuel cell at baseload at night, thus reducing the need for large battery systems to shift the solar power produced in the day to the night. In addition, the dispatchability of the fuel cell provided an extra degree of freedom necessary for unforeseen disturbances. An operation framework based on model predictive control showed that the method is suitable for optimizing the dispatch of the hybrid energy system.

KSC-2013-3934

NASA Image and Video Library

2013-11-07

CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, technicians monitor the progress as the fourth ogive panel is lifted by crane so that they can be installed on the Orion ground test vehicle in Vehicle Assembly Building high bay 4. Three of the panels have already been installed on the test vehicle. The ogive panels enclose and protect the Orion spacecraft and attach to the Launch Abort System. The test vehicle is being used by the Ground Systems Development and Operations Program for path finding operations, including simulated manufacturing, assembly and stacking procedures. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted test flight of Orion is scheduled to launch in 2014 atop a Delta IV rocket and in 2017 on NASA’s Space Launch System rocket. For more information, visit www.nasa.gov/orion. Photo credit: Kim Shiflett

KSC-2013-3929

NASA Image and Video Library

2013-10-30

CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, technicians monitor the progress as a crane is used to move one of four ogive panels closer for installation on the Orion ground test vehicle in Vehicle Assembly Building high bay 4. The ogive panels enclose and protect the Orion spacecraft and attach to the Launch Abort System. The test vehicle is being used by the Ground Systems Development and Operations Program for path finding operations, including simulated manufacturing, assembly and stacking procedures. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted test flight of Orion is scheduled to launch in 2014 atop a Delta IV rocket and in 2017 on NASA’s Space Launch System rocket. For more information, visit www.nasa.gov/orion. Photo credit: Kim Shiflett

KSC-2013-3936

NASA Image and Video Library

2013-11-07

CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, technicians monitor the progress as the fourth ogive panel is lifted by crane so that they can be installed on the Orion ground test vehicle in Vehicle Assembly Building high bay 4. Three of the panels have already been installed on the test vehicle. The ogive panels enclose and protect the Orion spacecraft and attach to the Launch Abort System. The test vehicle is being used by the Ground Systems Development and Operations Program for path finding operations, including simulated manufacturing, assembly and stacking procedures. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted test flight of Orion is scheduled to launch in 2014 atop a Delta IV rocket and in 2017 on NASA’s Space Launch System rocket. For more information, visit www.nasa.gov/orion. Photo credit: Kim Shiflett

KSC-2013-3935

NASA Image and Video Library

2013-11-07

CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, technicians monitor the progress as the fourth ogive panel is lifted by crane so that they can be installed on the Orion ground test vehicle in Vehicle Assembly Building high bay 4. Three of the panels have already been installed on the test vehicle. The ogive panels enclose and protect the Orion spacecraft and attach to the Launch Abort System. The test vehicle is being used by the Ground Systems Development and Operations Program for path finding operations, including simulated manufacturing, assembly and stacking procedures. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted test flight of Orion is scheduled to launch in 2014 atop a Delta IV rocket and in 2017 on NASA’s Space Launch System rocket. For more information, visit www.nasa.gov/orion. Photo credit: Kim Shiflett

KSC-2013-3928

NASA Image and Video Library

2013-10-30

CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, technicians monitor the progress as a crane is used to move one of four ogive panels closer for installation on the Orion ground test vehicle in Vehicle Assembly Building high bay 4. The ogive panels enclose and protect the Orion spacecraft and attach to the Launch Abort System. The test vehicle is being used by the Ground Systems Development and Operations Program for path finding operations, including simulated manufacturing, assembly and stacking procedures. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted test flight of Orion is scheduled to launch in 2014 atop a Delta IV rocket and in 2017 on NASA’s Space Launch System rocket. For more information, visit www.nasa.gov/orion. Photo credit: Kim Shiflett

Online estimation of internal stack temperatures in solid oxide fuel cell power generating units

NASA Astrophysics Data System (ADS)

Dolenc, B.; Vrečko, D.; Juričić, Ɖ.; Pohjoranta, A.; Pianese, C.

2016-12-01

Thermal stress is one of the main factors affecting the degradation rate of solid oxide fuel cell (SOFC) stacks. In order to mitigate the possibility of fatal thermal stress, stack temperatures and the corresponding thermal gradients need to be continuously controlled during operation. Due to the fact that in future commercial applications the use of temperature sensors embedded within the stack is impractical, the use of estimators appears to be a viable option. In this paper we present an efficient and consistent approach to data-driven design of the estimator for maximum and minimum stack temperatures intended (i) to be of high precision, (ii) to be simple to implement on conventional platforms like programmable logic controllers, and (iii) to maintain reliability in spite of degradation processes. By careful application of subspace identification, supported by physical arguments, we derive a simple estimator structure capable of producing estimates with 3% error irrespective of the evolving stack degradation. The degradation drift is handled without any explicit modelling. The approach is experimentally validated on a 10 kW SOFC system.

Enclosed ground-flare incinerator

DOEpatents

Wiseman, Thomas R.

2000-01-01

An improved ground flare is provided comprising a stack, two or more burner assemblies, and a servicing port so that some of the burner assemblies can be serviced while others remain in operation. The burner assemblies comprise a burner conduit and nozzles which are individually fitted to the stack's burner chamber and are each removably supported in the chamber. Each burner conduit is sealed to and sandwiched between a waste gas inlet port and a matching a closure port on the other side of the stack. The closure port can be opened for physically releasing the burner conduit and supplying sufficient axial movement room for extracting the conduit from the socket, thereby releasing the conduit for hand removal through a servicing port. Preferably, the lower end of the stack is formed of one or more axially displaced lower tubular shells which are concentrically spaced for forming annular inlets for admitting combustion air. An upper tubular exhaust stack, similarly formed, admits additional combustion air for increasing the efficiency of combustion, increasing the flow of exhausted for improved atmospheric dispersion and for cooling the upper stack.

In-Situ Measurement of High-Temperature Proton Exchange Membrane Fuel Cell Stack Using Flexible Five-in-One Micro-Sensor

PubMed Central

Lee, Chi-Yuan; Weng, Fang-Bor; Kuo, Yzu-Wei; Tsai, Chao-Hsuan; Cheng, Yen-Ting; Cheng, Chih-Kai; Lin, Jyun-Ting

2016-01-01

In the chemical reaction that proceeds in a high-temperature proton exchange membrane fuel cell stack (HT-PEMFC stack), the internal local temperature, voltage, pressure, flow and current nonuniformity may cause poor membrane material durability and nonuniform fuel distribution, thus influencing the performance and lifetime of the fuel cell stack. In this paper micro-electro-mechanical systems (MEMS) are utilized to develop a high-temperature electrochemical environment-resistant five-in-one micro-sensor embedded in the cathode channel plate of an HT-PEMFC stack, and materials and process parameters are appropriately selected to protect the micro-sensor against failure or destruction during long-term operation. In-situ measurement of the local temperature, voltage, pressure, flow and current distributions in the HT-PEMFC stack is carried out. This integrated micro-sensor has five functions, and is favorably characterized by small size, good acid resistance and temperature resistance, quick response, real-time measurement, and the goal is being able to be put in any place for measurement without affecting the performance of the battery. PMID:27763559

In-Situ Measurement of High-Temperature Proton Exchange Membrane Fuel Cell Stack Using Flexible Five-in-One Micro-Sensor.

PubMed

Lee, Chi-Yuan; Weng, Fang-Bor; Kuo, Yzu-Wei; Tsai, Chao-Hsuan; Cheng, Yen-Ting; Cheng, Chih-Kai; Lin, Jyun-Ting

2016-10-18

In the chemical reaction that proceeds in a high-temperature proton exchange membrane fuel cell stack (HT-PEMFC stack), the internal local temperature, voltage, pressure, flow and current nonuniformity may cause poor membrane material durability and nonuniform fuel distribution, thus influencing the performance and lifetime of the fuel cell stack. In this paper micro-electro-mechanical systems (MEMS) are utilized to develop a high-temperature electrochemical environment-resistant five-in-one micro-sensor embedded in the cathode channel plate of an HT-PEMFC stack, and materials and process parameters are appropriately selected to protect the micro-sensor against failure or destruction during long-term operation. In-situ measurement of the local temperature, voltage, pressure, flow and current distributions in the HT-PEMFC stack is carried out. This integrated micro-sensor has five functions, and is favorably characterized by small size, good acid resistance and temperature resistance, quick response, real-time measurement, and the goal is being able to be put in any place for measurement without affecting the performance of the battery.

Advancements in high-power diode laser stacks for defense applications

NASA Astrophysics Data System (ADS)

Pandey, Rajiv; Merchen, David; Stapleton, Dean; Patterson, Steve; Kissel, Heiko; Fassbender, Wilhlem; Biesenbach, Jens

2012-06-01

This paper reports on the latest advancements in vertical high-power diode laser stacks using micro-channel coolers, which deliver the most compact footprint, power scalability and highest power/bar of any diode laser package. We present electro-optical (E-O) data on water-cooled stacks with wavelengths ranging from 7xx nm to 9xx nm and power levels of up to 5.8kW, delivered @ 200W/bar, CW mode, and a power-conversion efficiency of >60%, with both-axis collimation on a bar-to-bar pitch of 1.78mm. Also, presented is E-O data on a compact, conductively cooled, hardsoldered, stack package based on conventional CuW and AlN materials, with bar-to-bar pitch of 1.8mm, delivering average power/bar >15W operating up to 25% duty cycle, 10ms pulses @ 45C. The water-cooled stacks can be used as pump-sources for diode-pumped alkali lasers (DPALs) or for more traditional diode-pumped solid-state lasers (DPSSL). which are power/brightness scaled for directed energy weapons applications and the conductively-cooled stacks as illuminators.

VALIDATION OF MERCURY CEMS WHEN COFIRING BIOMASS AT MADISON ELECTRIC'S BLOUNT STATION

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

Dennis L. Laudal; Jeffrey S. Thompson

2000-09-30

The state of Wisconsin has been concerned about mercury deposition into its lakes and streams and has been evaluating strategies to reduce mercury emissions. As part of this effort, the Blount Station, owned and operated by Madison Gas and Electric Company (MGE), has undergone a project to evaluate the effects and potential mercury emissions reduction of cofiring preconsumer waste. MGE owns and operates the Blount Generating Station located in central Madison, Wisconsin. At present, Blount operates with nine boilers and six turbine generators. The two largest boilers at Blount produce 400,000 pounds of steam per hour at 950 F andmore » 1250 psi. These larger boilers, MGE's Boiler Nos. 8 and 9, have the capability of cofiring both paper and plastic. MGE's Blount Generating Station was one of the first electric generating stations in the United States to retrofit its existing steam boilers to successfully burn refuse-derived fuel and other alternate fuels including waste paper and wood. It is the No. 9 boiler that was the focus of this project to determine the effect of cofiring PDF (plastic- and paper-derived fuel) on speciated mercury emissions. The project was laid out to compare four different fuel combinations: (1) coal feed only, (2) coal with plastic, (3) coal with paper, and (4) coal with paper and plastic. The design was to run the boiler for 2 days at each condition, thus allowing four samples to be taken at each condition. This plan was aimed at getting at least three representative samples at each condition and allowed for difficulties in sampling and boiler operation. The following objectives were accomplished as part of the project to determine the effects of cofiring PDF on mercury emissions and speciation at MGE Blount Station: Successfully completed all of the mercury sampling for each of the four boiler/PDF conditions using the Ontario Hydro (OH) mercury speciation method; Determined mercury concentrations at the stack location using mercury continuous emission monitors (CEMs) for each of the four boiler/PDF conditions; Calculated the overall mercury mass balance for each of the runs; Determined chlorine concentrations at the stack location using EPA Method 26A for each of the four boiler/PDF conditions; and Calculated speciated mercury flow to determine removal and/or transformations before its exiting the unit at the stack for each of the four boiler/PDF conditions.« less

Assessing the induced seismicity by hydraulic fracturing at the Wysin site (Poland)

NASA Astrophysics Data System (ADS)

Ángel López Comino, José; Cesca, Simone; Kriegerowski, Marius; Heimann, Sebastian; Dahm, Torsten; Mirek, Janusz; Lasocky, Stanislaw

2017-04-01

Induced seismicity related to industrial processes including shale gas and oil exploitation is a current issues that implies enough reasons to be concerned. Hydraulic fracturing usually induces weak events. However, scenarios with larger earthquakes are possible, e.g. if the injected fluids alter friction conditions and trigger the failure of neighbouring faults. This work is focused on a hydrofracking experiment monitored in the framework of the SHEER (SHale gas Exploration and Exploitation induced Risks) EU project at the Wysin site, located in the central-western part of the Peribaltic synclise of Pomerania, Poland. A specific network setup has been installed combining surface installation with three small-scale arrays and a shallow borehole installation. The fracking operations were carried out in June and July 2016 at a depth 4000 m. The monitoring has been operational before, during and after the termination of hydraulic fracturing operations. We apply a recently developed automated full waveform detection algorithm based on the stacking of smooth characteristic function and the identification of high coherence in the signals recorded at different stations. The method was tested with synthetic data and different detector levels yielding values of magnitude of completeness around 0.1. An unsupervised detection catalogue is generated with real data for a time period May-September 2016. We identify strong temporal changes (day/night) of the detection performance. A manual revision of the detected signals reveals that most detections are associated to local and regional seismic signals. Only two events could be assigned to the volume potentially affected by the fracking operations.

Engineering support for magnetohydrodynamic power plant analysis and design studies

NASA Technical Reports Server (NTRS)

Carlson, A. W.; Chait, I. L.; Marchmont, G.; Rogali, R.; Shikar, D.

1980-01-01

The major factors which influence the economic engineering selection of stack inlet temperatures in combined cycle MHD powerplants are identified and the range of suitable stack inlet temperatures under typical operating conditions is indicated. Engineering data and cost estimates are provided for four separately fired high temperature air heater (HTAH) system designs for HTAH system thermal capacity levels of 100, 250, 500 and 1000 MWt. An engineering survey of coal drying and pulverizing equipment for MHD powerplant application is presented as well as capital and operating cost estimates for varying degrees of coal pulverization.

Program scheme using common source lines in channel stacked NAND flash memory with layer selection by multilevel operation

NASA Astrophysics Data System (ADS)

Kim, Do-Bin; Kwon, Dae Woong; Kim, Seunghyun; Lee, Sang-Ho; Park, Byung-Gook

2018-02-01

To obtain high channel boosting potential and reduce a program disturbance in channel stacked NAND flash memory with layer selection by multilevel (LSM) operation, a new program scheme using boosted common source line (CSL) is proposed. The proposed scheme can be achieved by applying proper bias to each layer through its own CSL. Technology computer-aided design (TCAD) simulations are performed to verify the validity of the new method in LSM. Through TCAD simulation, it is revealed that the program disturbance characteristics is effectively improved by the proposed scheme.

Microseismic event location by master-event waveform stacking

NASA Astrophysics Data System (ADS)

Grigoli, F.; Cesca, S.; Dahm, T.

2016-12-01

Waveform stacking location methods are nowadays extensively used to monitor induced seismicity monitoring assoiciated with several underground industrial activities such as Mining, Oil&Gas production and Geothermal energy exploitation. In the last decade a significant effort has been spent to develop or improve methodologies able to perform automated seismological analysis for weak events at a local scale. This effort was accompanied by the improvement of monitoring systems, resulting in an increasing number of large microseismicity catalogs. The analysis of microseismicity is challenging, because of the large number of recorded events often characterized by a low signal-to-noise ratio. A significant limitation of the traditional location approaches is that automated picking is often done on each seismogram individually, making little or no use of the coherency information between stations. In order to improve the performance of the traditional location methods, in the last year, alternative approaches have been proposed. These methods exploits the coherence of the waveforms recorded at different stations and do not require any automated picking procedure. The main advantage of this methods relies on their robustness even when the recorded waveforms are very noisy. On the other hand, like any other location method, the location performance strongly depends on the accuracy of the available velocity model. When dealing with inaccurate velocity models, in fact, location results can be affected by large errors. Here we will introduce a new automated waveform stacking location method which is less dependent on the knowledge of the velocity model and presents several benefits, which improve the location accuracy: 1) it accounts for phase delays due to local site effects, e.g. surface topography or variable sediment thickness 2) theoretical velocity model are only used to estimate travel times within the source volume, and not along the whole source-sensor path. We finally compare the location results for both synthetics and real data with those obtained by using classical waveforms stacking approaches.

KSC-2013-3717

NASA Image and Video Library

2013-10-22

CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, technicians monitor the progress as the Orion ground test vehicle, or GTA, is lifted by crane in the transfer aisle of the Vehicle Assembly Building. The ground test vehicle is being used for path finding operations, including simulated manufacturing, assembly and stacking procedures. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted test flight of Orion is scheduled to launch in 2014 atop a Delta IV rocket and in 2017 on NASA’s Space Launch System rocket. For more information, visit www.nasa.gov/orion. Photo credit: Dimitri Gerondidakis

KSC-2013-3719

NASA Image and Video Library

2013-10-22

CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, technicians monitor the progress as the Orion ground test vehicle, or GTA, is lifted by crane in the transfer aisle of the Vehicle Assembly Building. The ground test vehicle is being used for path finding operations, including simulated manufacturing, assembly and stacking procedures. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted test flight of Orion is scheduled to launch in 2014 atop a Delta IV rocket and in 2017 on NASA’s Space Launch System rocket. For more information, visit www.nasa.gov/orion. Photo credit: Dimitri Gerondidakis

KSC-04PD-2561

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In a Vehicle Assembly Building (VAB) high bay, workers monitor the movement of a Solid Rocket Booster (SRB) aft center segment as it is lowered toward an aft segment already secured to a Mobile Launch Platform. These segments are part of the right SRB for the Space Shuttle Return to Flight mission, STS-114. Two SRBs are stacked on a Mobile Launch Platform for each Shuttle flight and later joined by an External Tank. The twin 149-foot tall, 12-foot diameter SRBs provide the main propulsion system during launch. They operate in parallel with the Space Shuttle main engines for the first two minutes of flight and jettison away from the orbiter with help from the Booster Separation Motors, about 26.3 nautical miles above the Earths surface.

Method and apparatus for adding electrolyte to a fuel cell stack

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

Congdon, J.V.; English, J.G.

1986-06-24

A process is described for adding electrolyte to a fuel cell stack, the stack comprising sheet-like elements defining a plurality of fuel cell units disposed one atop the other in abutting relationship, the units defining a substantially flat, vertically extending face, each unit including a cell comprising a pair of sheet-like spaced apart gas porous electrodes with a porous matrix layer sandwiched therebetween for retaining electrolyte during cell operation, each unit also including a sheet-like substantially non-porous separator, the separator being sandwiched between the cells of adjacent units. The improvement described here consists of: extending at least one of themore » sheet-like elements of each of a plurality of the fuel cell units outwardly from the stack face to define horizontal tabs disposed one above the other; depositing dilute electrolyte directly from electrolyte supply means upon substantially the full length, parallel to the stack face, of at least the uppermost tab, the tabs being constructed and arranged such that at least a portion of the deposited electrolyte cascades from tab to tab and down the face of the stack, the deposited electrolyte being absorbed by capillary action into the elements of the stack, the step of depositing continuing until all of the electrodes and matrix layers of the stack are fully saturated with the dilute electrolyte; and thereafter evaporating liquid from the saturated elements under controlled conditions of humidity and temperature until the stack has a desired electrolyte volume and electrolyte concentration therein.« less

Nondestructive cell evaluation techniques in SOFC stack manufacturing

NASA Astrophysics Data System (ADS)

Wunderlich, C.

2016-04-01

Independent from the specifics of the application, a cost efficient manufacturing of solid oxide fuel cells (SOFC), its electrolyte membranes and other stack components, leading to reliable long-life stacks is the key for the commercial viability of this fuel cell technology. Tensile and shear stresses are most critical for ceramic components and especially for thin electrolyte membranes as used in SOFC cells. Although stack developers try to reduce tensile stresses acting on the electrolyte by either matching CTE of interconnects and electrolytes or by putting SOFC cells under some pressure - at least during transient operation of SOFC stacks ceramic cells will experience some tensile stresses. Electrolytes are required to have a high Weibull characteristic fracture strength. Practical experiences in stack manufacturing have shown that statistical fracture strength data generated by tests of electrolyte samples give limited information on electrolyte or cell quality. In addition, the cutting process of SOFC electrolytes has a major influence on crack initiation. Typically, any single crack in one the 30 to 80 cells in series connection will lead to a premature stack failure drastically reducing stack service life. Thus, for statistical reasons only 100% defect free SOFC cells must be assembled in stacks. This underlines the need for an automated inspection. So far, only manual processes of visual or mechanical electrolyte inspection are established. Fraunhofer IKTS has qualified the method of optical coherence tomography for an automated high throughput inspection. Alternatives like laser speckle photometry and acoustical methods are still under investigation.

A metallic interconnect for a solid oxide fuel cell stack

NASA Astrophysics Data System (ADS)

England, Diane Mildred

A solid oxide fuel cell (SOFC) electrochemically converts the chemical energy of reaction into electrical energy. The commercial success of planar, SOFC stack technology has a number of challenges, one of which is the interconnect that electrically and physically connects the cathode of one cell to the anode of an adjacent cell in the SOFC stack and in addition, separates the anodic and cathodic gases. An SOFC stack operating at intermediate temperatures, between 600°C and 800°C, can utilize a metallic alloy as an interconnect material. Since the interconnect of an SOFC stack must operate in both air and fuel environments, the oxidation kinetics, adherence and electronic resistance of the oxide scales formed on commercial alloys were investigated in air and wet hydrogen under thermal cycling conditions to 800°C. The alloy, Haynes 230, exhibited the slowest oxidation kinetics and the lowest area-specific resistance as a function of oxidation time of all the alloys in air at 800°C. However, the area-specific resistance of the oxide scale formed on Haynes 230 in wet hydrogen was unacceptably high after only 500 hours of oxidation, which was attributed to the high resistivity of Cr2O3 in a reducing atmosphere. A study of the electrical conductivity of the minor phase manganese chromite, MnXCr3-XO4, in the oxide scale of Haynes 230, revealed that a composition closer to Mn2CrO4 had significantly higher electrical conductivity than that closer to MnCr 2O4. Haynes 230 was coated with Mn to form a phase closer to the Mn2CrO4 composition for application on the fuel side of the interconnect. U.S. Patent No. 6,054,231 is pending. Although coating a metallic alloy is inexpensive, the stringent economic requirements of SOFC stack technology required an alloy without coating for production applications. As no commercially available alloy, among the 41 alloys investigated, performed to the specifications required, a new alloy was created and designated DME-A2. The oxide scale formed on DME-A2 at 800°C exhibited extremely high electrical conductivity with respect to the commercially available alloys studied. This new alloy shows great promise for use as an interconnect material for a planar SOFC stack operating at intermediate temperatures.

Evaluation of distributed gas cooling of pressurized PAFC for utility power generation

NASA Technical Reports Server (NTRS)

Farooque, M.; Maru, H.; Skok, A.

1981-01-01

Two short stacks were pressure tested at 446 kPa (4.4 atm.) and the pressure gains were more than the theoretically predicted gains. Temperature profiles were observed to be independent of operating pressure. The pressure drop was found to be inversely proportional to operating pressure as expected. Continuous pressurized operation of a stack for 1000 hours verified the compatability of the fuel cell component design. A simple pressurization procedure was also developed. Six separate designs, covering two gas cooling schemes (DIGAS and separated) and two cooling channel geometries (straight through and treed), were analysed on the net voltage output basis. Separated cooling with 5 cells per cooler was recognized to be the best among the designs considered.

40 CFR 60.743 - Compliance provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... operations not using carbon adsorption beds with individual exhausts. This method is applicable when the... carbon adsorption system with individual exhaust stacks for each adsorber vessel. The owner or operator... operations using carbon adsorption beds with individual exhausts. This method is applicable when emissions...

40 CFR 60.743 - Compliance provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... operations not using carbon adsorption beds with individual exhausts. This method is applicable when the... carbon adsorption system with individual exhaust stacks for each adsorber vessel. The owner or operator... operations using carbon adsorption beds with individual exhausts. This method is applicable when emissions...

40 CFR 60.743 - Compliance provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... operations not using carbon adsorption beds with individual exhausts. This method is applicable when the... carbon adsorption system with individual exhaust stacks for each adsorber vessel. The owner or operator... operations using carbon adsorption beds with individual exhausts. This method is applicable when emissions...

2000W high beam quality diode laser for direct materials processing

NASA Astrophysics Data System (ADS)

Qin, Wen-bin; Liu, You-qiang; Cao, Yin-hua; Gao, Jing; Pan, Fei; Wang, Zhi-yong

2011-11-01

This article describes high beam quality and kilowatt-class diode laser system for direct materials processing, using optical design software ZEMAX® to simulate the diode laser optical path, including the beam shaping, collimation, coupling, focus, etc.. In the experiment, the diode laser stack of 808nm and the diode laser stack of 915nm were used for the wavelength coupling, which were built vertical stacks up to 16 bars. The threshold current of the stack is 6.4A, the operating current is 85A and the output power is 1280W. Through experiments, after collimating the diode laser beam with micro-lenses, the fast axis BPP of the stack is less than 60mm.mrad, and the slow-axis BPP of the stack is less than 75mm.mrad. After shaping the laser beam and improving the beam quality, the fast axis BPP of the stack is still 60mm.mrad, and the slow-axis BPP of the stack is less than 19mm.mrad. After wavelength coupling and focusing, ultimately the power of 2150W was obtained, focal spot size of 1.5mm * 1.2mm with focal length 300mm. The laser power density is 1.2×105W/cm2, and that can be used for metal remelting, alloying, cladding and welding. The total optical coupling conversion efficiency is 84%, and the total electrical - optical conversion efficiency is 50%.

Investigation of sulfonated polysulfone membranes as electrolyte in a passive-mode direct methanol fuel cell mini-stack

NASA Astrophysics Data System (ADS)

Lufrano, F.; Baglio, V.; Staiti, P.; Stassi, A.; Aricò, A. S.; Antonucci, V.

This paper reports on the development of polymer electrolyte membranes (PEMs) based on sulfonated polysulfone for application in a DMFC mini-stack operating at room temperature in passive mode. The sulfonated polysulfone (SPSf) with two degrees of sulfonation (57 and 66%) was synthesized by a well-known sulfonation process. SPSf membranes with different thicknesses were prepared and investigated. These membranes were characterized in terms of methanol/water uptake, proton conductivity, and fuel cell performance in a DMFC single cell and mini-stack operating at room temperature. The study addressed (a) control of the synthesis of sulfonated polysulfone, (b) optimization of the assembling procedure, (c) a short lifetime investigation and (d) a comparison of DMFC performance in active-mode operation vs. passive-mode operation. The best passive DMFC performance was 220 mW (average cell power density of about 19 mW cm -2), obtained with a thin SPSf membrane (70 μm) at room temperature, whereas the performance of the same membrane-based DMFC in active mode was 38 mW cm -2. The conductivity of this membrane, SPSf (IEC = 1.34 mequiv. g -1) was 2.8 × 10 -2 S cm -1. A preliminary short-term test (200 min) showed good stability during chrono-amperometry measurements.

Regenerative fuel cell study for satellites in GEO orbit

NASA Technical Reports Server (NTRS)

Levy, Alexander; Vandine, Leslie L.; Stedman, James K.

1987-01-01

Summarized are the results of a 12-month study to identify high performance regenerative hydrogen-oxygen fuel cell concepts for geosynchronous satellite application. Emphasis was placed on concepts with the potential for high energy density (W-hr/lb) and passive means for water and heat management to maximize system reliability. Both polymer membrane and alkaline electrolyte fuel cells were considered, with emphasis on the alkaline cell because of its high performance, advanced state of development, and proven ability to operate in a launch and space environment. Three alkaline system concepts were studied. The first, the integrated design, utilized a configuration in which the fuel cell and electrolysis cells are alternately stacked inside a pressure vessel. Product water is transferred by diffusion during electrolysis and waste heat is conducted through the pressure wall, thus using completely passive means for transfer and control. The second alkaline system, the dedicated design, uses a separate fuel cell and electrolysis stack so that each unit can be optimized in size and weight based on its orbital operating period. The third design was a dual function stack configuration, in which each cell can operate in both fuel cell and electrolysis mode, thus eliminating the need for two separate stacks and associated equipment. Results indicate that using near term technology energy densities between 46 and 52 W-hr/lb can be achieved at efficiencies of 55 percent. System densities of 115 W-hr/lb are contemplated.

System Design of a Natural Gas PEM Fuel Cell Power Plant for Buildings

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

Joe Ferrall, Tim Rehg, Vesna Stanic

2000-09-30

The following conclusions are made based on this analysis effort: (1) High-temperature PEM data are not available; (2) Stack development effort for Phase II is required; (3) System results are by definition preliminary, mostly due to the immaturity of the high-temperature stack; other components of the system are relatively well defined; (4) The Grotthuss conduction mechanism yields the preferred system characteristics; the Grotthuss conduction mechanism is also much less technically mature than the vehicle mechanism; (5) Fuel processor technology is available today and can be procured for Phase II (steam or ATR); (6) The immaturity of high-temperature membrane technology requiresmore » that a robust system design be developed in Phase II that is capable of operating over a wide temperature and pressure range - (a) Unpressurized or Pressurized PEM (Grotthuss mechanism) at 140 C, Highest temperature most favorable, Lowest water requirement most favorable, Pressurized recommended for base loaded operation, Unpressurized may be preferred for load following; (b) Pressurized PEM (vehicle mechanism) at about 100 C, Pressure required for saturation, Fuel cell technology currently available, stack development required. The system analysis and screening evaluation resulted in the identification of the following components for the most promising system: (1) Steam reforming fuel processor; (2) Grotthuss mechanism fuel cell stack operating at 140 C; (3) Means to deliver system waste heat to a cogeneration unit; (4) Pressurized system utilizing a turbocompressor for a base-load power application. If duty cycling is anticipated, the benefits of compression may be offset due to complexity of control. In this case (and even in the base loaded case), the turbocompressor can be replaced with a blower for low-pressure operation.« less

Combined analysis of modeled and monitored SO2 concentrations at a complex smelting facility.

PubMed

Rehbein, Peter J G; Kennedy, Michael G; Cotsman, David J; Campeau, Madonna A; Greenfield, Monika M; Annett, Melissa A; Lepage, Mike F

2014-03-01

Vale Canada Limited owns and operates a large nickel smelting facility located in Sudbury, Ontario. This is a complex facility with many sources of SO2 emissions, including a mix of source types ranging from passive building roof vents to North America's tallest stack. In addition, as this facility performs batch operations, there is significant variability in the emission rates depending on the operations that are occurring. Although SO2 emission rates for many of the sources have been measured by source testing, the reliability of these emission rates has not been tested from a dispersion modeling perspective. This facility is a significant source of SO2 in the local region, making it critical that when modeling the emissions from this facility for regulatory or other purposes, that the resulting concentrations are representative of what would actually be measured or otherwise observed. To assess the accuracy of the modeling, a detailed analysis of modeled and monitored data for SO2 at the facility was performed. A mobile SO2 monitor sampled at five locations downwind of different source groups for different wind directions resulting in a total of 168 hr of valid data that could be used for the modeled to monitored results comparison. The facility was modeled in AERMOD (American Meteorological Society/U.S. Environmental Protection Agency Regulatory Model) using site-specific meteorological data such that the modeled periods coincided with the same times as the monitored events. In addition, great effort was invested into estimating the actual SO2 emission rates that would likely be occurring during each of the monitoring events. SO2 concentrations were modeled for receptors around each monitoring location so that the modeled data could be directly compared with the monitored data. The modeled and monitored concentrations were compared and showed that there were no systematic biases in the modeled concentrations. This paper is a case study of a Combined Analysis of Modelled and Monitored Data (CAMM), which is an approach promulgated within air quality regulations in the Province of Ontario, Canada. Although combining dispersion models and monitoring data to estimate or refine estimates of source emission rates is not a new technique, this study shows how, with a high degree of rigor in the design of the monitoring and filtering of the data, it can be applied to a large industrial facility, with a variety of emission sources. The comparison of modeled and monitored SO2 concentrations in this case study also provides an illustration of the AERMOD model performance for a large industrial complex with many sources, at short time scales in comparison with monitored data. Overall, this analysis demonstrated that the AERMOD model performed well.

FM-to-AM modulations induced by a weak residual reflection stack of sine-modulated pulses in inertial confinement fusion laser systems

NASA Astrophysics Data System (ADS)

Huang, Xiaoxia; Deng, Xuewei; Zhou, Wei; Hu, Dongxia; Guo, Huaiwen; Wang, Yuancheng; Zhao, Bowang; Zhong, Wei; Deng, Wu

2018-02-01

We report on frequency to amplitude modulation (FM-to-AM) conversion induced by a weak residual reflection stack of sine-modulated pulses in a complex laser system. Theoretical and experimental investigations reveal that when weak residual reflected pulses stack on the main pulse, the spectral intensity changes in the stacked region, which then converts to obvious AM. This kind of FM-to-AM effect often occurs in the tail of the pulse and cannot be eliminated by common compensation methods, which even enhance the modulation depth. Furthermore, the actual intensity modulation frequency and depth induced by the residual reflection stack are much higher and deeper than observed on the oscilloscope, which is harmful for safe operation of the laser facility and the driving power balance during inertial confinement fusion. To eliminate this kind of FM-to-AM effect, any possible on-axis and near-axis residual reflection in laser systems must be avoided.

Scale dependant compensational stacking of channelized sedimentary deposits

NASA Astrophysics Data System (ADS)

Wang, Y.; Straub, K. M.; Hajek, E. A.

2010-12-01

Compensational stacking, the tendency for sediment transport system to preferentially fill topographic lows, thus smoothing out topographic relief is a concept used in the interpretation of the stratigraphic record. Recently, a metric was developed to quantify the strength of compensation in sedimentary basins by comparing observed stacking patterns to what would be expected from simple, uncorrelated stacking. This method uses the rate of decay of spatial variability in sedimentation between picked depositional horizons with increasing vertical stratigraphic averaging distance. We explore how this metric varies as a function of stratigraphic scale using data from physical experiments, stratigraphy exposed in outcrops and numerical models. In an experiment conducted at Tulane University’s Sediment Dynamics Laboratory, the topography of a channelized delta formed by weakly cohesive sediment was monitored along flow-perpendicular transects at a high temporal resolution relative to channel kinematics. Over the course of this experiment a uniform relative subsidence pattern, designed to isolate autogenic processes, resulted in the construction of a stratigraphic package that is 25 times as thick as the depth of the experimental channels. We observe a scale-dependence on the compensational stacking of deposits set by the system’s avulsion time-scale. Above the avulsion time-scale deposits stack purely compensationally, but below this time-scale deposits stack somewhere between randomly and deterministically. The well-exposed Ferris Formation (Cretaceous/Paleogene, Hanna Basin, Wyoming, USA) also shows scale-dependant stratigraphic organization which appears to be set by an avulsion time-scale. Finally, we utilize simple object-based models to illustrate how channel avulsions influence compensation in alluvial basins.

Solid oxide fuel cell short stack performance testing - Part A: Experimental analysis and μ-combined heat and power unit comparison

NASA Astrophysics Data System (ADS)

Mastropasqua, L.; Campanari, S.; Brouwer, J.

2017-12-01

The need to experimentally understand the detailed performance of SOFC stacks under operating conditions typical of commercial SOFC systems has prompted this two-part study. The steady state performance of a 6-cell short stack of yttria (Y2O3) stabilised zirconia (YSZ) with Ni/YSZ anodes and composite Sr-doped lanthanum manganite (LaMnO3, LSM)/YSZ cathodes is experimentally evaluated. In Part A, the stack characterisation is carried out by means of sensitivity analyses on the fuel utilisation factor and the steam-to-carbon ratio. Electrical and environmental performances are assessed and the results are compared with a commercial full-scale micro-CHP system, which comprises the same cells. The results show that the measured temperature dynamics of the short stack in a test stand environment are on the order of many minutes; therefore, one cannot neglect temperature dynamics for a precise measurement of the steady state polarisation behaviour. The overall polarisation performance is comparable to that of the full stack employed in the micro-CHP system, confirming the good representation that short-stack analyses can give of the entire SOFC module. The environmental performance is measured verifying the negligible values of NO emissions (<10 ppb) across the whole polarisation curve.

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

Shoup, R.W.; Long, F.; Martin, T.H.

Sandia has developed PBFA-Z, a 20-MA driver for z-pinch experiments by replacing the water lines, insulator stack. and MITLs on PBFA II with hardware of a new design. The PBFA-Z accelerator was designed to deliver 20 MA to a 15-mg z-pinch load in 100 ns. The accelerator was modeled using circuit codes to determine the time-dependent voltage and current waveforms at the input and output of the water lines, the insulator stack, and the MITLs. The design of the vacuum insulator stack was dictated by the drive voltage, the electric field stress and grading requirements, the water line and MITLmore » interface requirements, and the machine operations and maintenance requirements. The insulator stack consists of four separate modules, each of a different design because of different voltage drive and hardware interface requirements. The shape of the components in each module, i.e., grading rings, insulator rings, flux excluders, anode and cathode conductors, and the design of the water line and MITL interfaces, were optimized by using the electrostatic analysis codes, ELECTRO and JASON. The time-dependent performance of the insulator stacks was evaluated using IVORY, a 2-D PIC code. This paper will describe the insulator stack design, present the results of the ELECTRO and IVORY analyses, and show the results of the stack measurements.« less

Development and Experimental Evaluation of Passive Fuel Cell Thermal Control

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.; Jakupca, Ian J.; Castle, Charles H.; Burke, Kenneth A.

2014-01-01

To provide uniform cooling for a fuel cell stack, a cooling plate concept was evaluated. This concept utilized thin cooling plates to extract heat from the interior of a fuel cell stack and move this heat to a cooling manifold where it can be transferred to an external cooling fluid. The advantages of this cooling approach include a reduced number of ancillary components and the ability to directly utilize an external cooling fluid loop for cooling the fuel cell stack. A number of different types of cooling plates and manifolds were developed. The cooling plates consisted of two main types; a plate based on thermopyrolytic graphite (TPG) and a planar (or flat plate) heat pipe. The plates, along with solid metal control samples, were tested for both thermal and electrical conductivity. To transfer heat from the cooling plates to the cooling fluid, a number of manifold designs utilizing various materials were devised, constructed, and tested. A key aspect of the manifold was that it had to be electrically nonconductive so it would not short out the fuel cell stack during operation. Different manifold and cooling plate configurations were tested in a vacuum chamber to minimize convective heat losses. Cooling plates were placed in the grooves within the manifolds and heated with surface-mounted electric pad heaters. The plate temperature and its thermal distribution were recorded for all tested combinations of manifold cooling flow rates and heater power loads. This testing simulated the performance of the cooling plates and manifold within an operational fuel cell stack. Different types of control valves and control schemes were tested and evaluated based on their ability to maintain a constant temperature of the cooling plates. The control valves regulated the cooling fluid flow through the manifold, thereby controlling the heat flow to the cooling fluid. Through this work, a cooling plate and manifold system was developed that could maintain the cooling plates within a minimal temperature band with negligible thermal gradients over power profiles that would be experienced within an operating fuel cell stack.

On Orbit ISS Oxygen Generation System Operation Status

NASA Technical Reports Server (NTRS)

Diderich, Greg S.; Polis, Pete; VanKeuren, Steven P.; Erickson, Robert; Mason, Richard

2011-01-01

The International Space Station (ISS) United States Orbital Segment (USOS) Oxygen Generation System (OGS) has accumulated almost a year of operation at varied oxygen production rates within the US Laboratory Module (LAB) since it was first activated in July 2007. It was operated intermittently through 2009 and 2010, due to filter clogging and acid accumulation in the recirculation loop. Since the installation of a deionizing bed in the recirculation loop in May of 2011 the OGA has been operated continuously. Filters in the recirculation loop have clogged and have been replaced. Hydrogen sensors have drifted apart, and a power failure may have condensed water on a hydrogen sensor. A pump delta pressure sensor failed, and a replacement new spare pump failed to start. Finally, the voltage across the cell stack increased out of tolerance due to cation contamination, and the cell stack was replaced. This paper will discuss the operating experience and characteristics of the OGS, as well as operational issues and their resolution.

Operating experience with a 250 kW el molten carbonate fuel cell (MCFC) power plant

NASA Astrophysics Data System (ADS)

Bischoff, Manfred; Huppmann, Gerhard

The MTU MCFC program is carried out by a European consortium comprising the German companies MTU Friedrichshafen GmbH, Ruhrgas AG and RWE Energie AG as well as the Danish company Energi E2 S/A. MTU acts as consortium leader. The company shares a license and technology exchange agreement with Fuel Cell Energy Inc., Danbury, CT, USA (formerly Energy Research Corp., ERC). The program was started in 1990 and covers a period of about 10 years. The highlights of this program to date are: Considerable improvements regarding component stability have been demonstrated on laboratory scale. Manufacturing technology has been developed to a point which enables the consortium to fabricate the porous components on a 250 cm 2 scale. Several large area stacks with 5000-7660 cm 2 cell area and a power range of 3-10 kW have been tested at the facilities in Munich (Germany) and Kyndby (Denmark). These stacks have been supplied by FCE. As far as the system design is concerned it was soon realized that conventional systems do not hold the promise for competitive power plants. A system analysis led to the conclusion that a new innovative design approach is required. As a result the "Hot Module" system was developed by the consortium. A Hot Module combines all the components of a MCFC system operating at the similar temperatures and pressures into a common thermally insulated vessel. In August 1997 the consortium started its first full size Hot Module MCFC test plant at the facilities of Ruhrgas AG in Dorsten, Germany. The stack was assembled in Munich using 292 cell packages purchased from FCE. The plant is based on the consortium's unique and proprietary "Hot Module" concept. It operates on pipeline natural gas and was grid connected on 16 August 1997. After a total of 1500 h of operation, the plant was intentionally shut down in a controlled manner in April 1998 for post-test analysis. The Hot Module system concept has demonstrated its functionality. The safety concept has been convincingly proven, though in part unintentionally. The electrical power level of 155 kW (ca. 60% of maximum power) achieved allows validation of the concept with reasonable degree of confidence. Horizontal stack operation—an essential innovation of the Hot Module concept—is feasible. The fuel processing subsystem worked reliably as expected. After initial problems in the inverter control software, the electrical and control subsystem operated to full satisfaction. Stable automatic operation not only under various load conditions, but also in idle mode, hot parking mode, and grid-independent mode has been demonstrated. Together with progress achieved by FCE in the qualification of large direct fuel cell (DFC) stacks the basis was laid for the next test unit of similar design, which will be operated in Bielefeld, Germany. The pre-tests of the stack took place already in July 1999 with good results. Additionally, projects for the test of the DFC Hot Module operating on biogas and other opportunity fuels are under preparation.

Multimodal Freight Distribution to Support Increased Port Operations

DOT National Transportation Integrated Search

2016-10-01

To support improved port operations, three different aspects of multimodal freight distribution are investigated: (i) Efficient load planning for double stack trains at inland ports; (ii) Optimization of a multimodal network for environmental sustain...

Production of medically useful bromine isotopes via alpha-particle induced nuclear reactions

NASA Astrophysics Data System (ADS)

Breunig, Katharina; Scholten, Bernhard; Spahn, Ingo; Hermanne, Alex; Spellerberg, Stefan; Coenen, Heinz H.; Neumaier, Bernd

2017-09-01

The cross sections of α-particle induced reactions on arsenic leading to the formation of 76,77,78Br were measured from their respective thresholds up to 37 MeV. Thin sediments of elemental arsenic powder were irradiated together with Al degrader and Cu monitor foils using the established stacked-foil technique. For determination of the effective α-particle energies and of the effective beam current through the stacks the cross-section ratios of the monitor nuclides 67Ga/66Ga were used. This should help resolve discrepancies in existing literature data. Comparison of the data with the available excitation functions shows some slight energy shifts as well as some differences in curve shapes. The calculated thick target yields indicate, that 77Br can be produced in the energy range Eα = 25 → 17 MeV free of isotopic impurities in quantities sufficient for medical application.

In situ monitoring of stacking fault formation and its carrier lifetime mediation in p-type 4H-SiC

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

Chen, Bin, E-mail: chenbinmse@gmail.com; Chen, Jun; Yao, Yuanzhao

Using the fine control of an electron beam (e-beam) in scanning electron microscopy with the capabilities of both electrical and optical imaging, the stacking fault (SF) formation together with its tuning of carrier lifetime was in situ monitored and investigated in p-type 4H-SiC homoepitaxial films. The SFs were formed through engineering basal plane dislocations with the energy supplied by the e-beam. The e-beam intensity required for the SF formation in the p-type films was ∼100 times higher than that in the n-type ones. The SFs reduced the minority-carrier lifetime in the p-type films, which was opposite to that observed inmore » the n-type case. The reason for the peculiar SF behavior in the p-type 4H-SiC is discussed with the cathodoluminescence results.« less

Thermo-Mechanical and Electrochemistry Modeling of Planar SOFC Stacks

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

Khaleel, Mohammad A.; Recknagle, Kurtis P.; Lin, Zijing

2002-12-01

Modeling activities at PNNL support design and development of modular SOFC systems. The SOFC stack modeling capability at PNNL has developed to a level at which planar stack designs can be compared and optimized for startup performance. Thermal-fluids and stress modeling is being performed to predict the transient temperature distribution and to determine the thermal stresses based on the temperature distribution. Current efforts also include the development of a model for calculating current density, cell voltage, and heat production in SOFC stacks with hydrogen or other fuels. The model includes the heat generation from both Joule heating and chemical reactions.more » It also accounts for species production and destruction via mass balance. The model is being linked to the finite element code MARC to allow for the evaluation of temperatures and stresses during steady state operations.« less

High Temperature Steam Electrolysis: Demonstration of Improved Long-Term Performance

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

J. E. O'Brien; X. Zhang; R. C. O'Brien

2011-11-01

Long-term performance is an ongoing issue for hydrogen production based on high-temperature steam electrolysis (HTSE). For commercial deployment, solid-oxide electrolysis stacks must achieve high performance with long-term degradation rates of {approx}0.5%/1000 hours or lower. Significant progress has been achieved toward this goal over the past few years. This paper will provide details of progress achieved under the Idaho National Laboratory high temperature electrolysis research program. Recent long-term stack tests have achieved high initial performance with degradation rates less than 5%/khr. These tests utilize internally manifolded stacks with electrode-supported cells. The cell material sets are optimized for the electrolysis mode ofmore » operation. Details of the cells and stacks will be provided along with details of the test apparatus, procedures, and results.« less

KSC-2014-4344

NASA Image and Video Library

2014-10-29

CAPE CANAVERAL, Fla. – A crane is lowered toward the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, during uncrating operations in the Building 2 south encapsulation bay at the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. The MMS upper stack, mini-stack number 2, is scheduled to arrive in about two weeks. MMS is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration and turbulence. Launch aboard a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station is targeted for March 12, 2015. To learn more about MMS, visit http://mms.gsfc.nasa.gov. Photo credit: NASA/Dan Casper

KSC-2014-4343

NASA Image and Video Library

2014-10-29

CAPE CANAVERAL, Fla. – Workers prepare a payload dolly for the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, during uncrating operations in the Building 2 south encapsulation bay at the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. The MMS upper stack, mini-stack number 2, is scheduled to arrive in about two weeks. MMS is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration and turbulence. Launch aboard a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station is targeted for March 12, 2015. To learn more about MMS, visit http://mms.gsfc.nasa.gov. Photo credit: NASA/Dan Casper

KSC-2014-4345

NASA Image and Video Library

2014-10-29

CAPE CANAVERAL, Fla. – Two of the observatories, the lower stack, mini-stack number 1, for NASA's Magnetospheric Multiscale Observatory, or MMS, glides toward a payload dolly during uncrating operations in the Building 2 south encapsulation bay at the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. The MMS upper stack, mini-stack number 2, is scheduled to arrive in about two weeks. MMS is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration and turbulence. Launch aboard a United Launch Alliance Atlas V rocket from Space Launch Complex 41 on Cape Canaveral Air Force Station is targeted for March 12, 2015. To learn more about MMS, visit http://mms.gsfc.nasa.gov. Photo credit: NASA/Dan Casper

MSuPDA: A Memory Efficient Algorithm for Sequence Alignment.

PubMed

Khan, Mohammad Ibrahim; Kamal, Md Sarwar; Chowdhury, Linkon

2016-03-01

Space complexity is a million dollar question in DNA sequence alignments. In this regard, memory saving under pushdown automata can help to reduce the occupied spaces in computer memory. Our proposed process is that anchor seed (AS) will be selected from given data set of nucleotide base pairs for local sequence alignment. Quick splitting techniques will separate the AS from all the DNA genome segments. Selected AS will be placed to pushdown automata's (PDA) input unit. Whole DNA genome segments will be placed into PDA's stack. AS from input unit will be matched with the DNA genome segments from stack of PDA. Match, mismatch and indel of nucleotides will be popped from the stack under the control unit of pushdown automata. During the POP operation on stack, it will free the memory cell occupied by the nucleotide base pair.

Reliability analysis and initial requirements for FC systems and stacks

NASA Astrophysics Data System (ADS)

Åström, K.; Fontell, E.; Virtanen, S.

In the year 2000 Wärtsilä Corporation started an R&D program to develop SOFC systems for CHP applications. The program aims to bring to the market highly efficient, clean and cost competitive fuel cell systems with rated power output in the range of 50-250 kW for distributed generation and marine applications. In the program Wärtsilä focuses on system integration and development. System reliability and availability are key issues determining the competitiveness of the SOFC technology. In Wärtsilä, methods have been implemented for analysing the system in respect to reliability and safety as well as for defining reliability requirements for system components. A fault tree representation is used as the basis for reliability prediction analysis. A dynamic simulation technique has been developed to allow for non-static properties in the fault tree logic modelling. Special emphasis has been placed on reliability analysis of the fuel cell stacks in the system. A method for assessing reliability and critical failure predictability requirements for fuel cell stacks in a system consisting of several stacks has been developed. The method is based on a qualitative model of the stack configuration where each stack can be in a functional, partially failed or critically failed state, each of the states having different failure rates and effects on the system behaviour. The main purpose of the method is to understand the effect of stack reliability, critical failure predictability and operating strategy on the system reliability and availability. An example configuration, consisting of 5 × 5 stacks (series of 5 sets of 5 parallel stacks) is analysed in respect to stack reliability requirements as a function of predictability of critical failures and Weibull shape factor of failure rate distributions.

Randomly Detected Genetically Modified (GM) Maize (Zea mays L.) near a Transport Route Revealed a Fragile 45S rDNA Phenotype

PubMed Central

Waminal, Nomar Espinosa; Ryu, Ki Hyun; Choi, Sun-Hee; Kim, Hyun Hee

2013-01-01

Monitoring of genetically modified (GM) crops has been emphasized to prevent their potential effects on the environment and human health. Monitoring of the inadvertent dispersal of transgenic maize in several fields and transport routes in Korea was carried out by qualitative multiplex PCR, and molecular analyses were conducted to identify the events of the collected GM maize. Cytogenetic investigations through fluorescence in situ hybridization (FISH) of the GM maize were performed to check for possible changes in the 45S rDNA cluster because this cluster was reported to be sensitive to replication and transcription stress. Three GM maize kernels were collected from a transport route near Incheon port, Korea, and each was found to contain NK603, stacked MON863 x NK603, and stacked NK603 x MON810 inserts, respectively. Cytogenetic analysis of the GM maize containing the stacked NK603 x MON810 insert revealed two normal compact 5S rDNA signals, but the 45S rDNA showed a fragile phenotype, demonstrating a “beads-on-a-string” fragmentation pattern, which seems to be a consequence of genetic modification. Implications of the 45S rDNA cluster fragility in GM maize are also discussed. PMID:24040165

Creep Mechanisms of a Ni-Co-Based-Wrought Superalloy with Low Stacking Fault Energy

NASA Astrophysics Data System (ADS)

Tian, Chenggang; Xu, Ling; Cui, Chuanyong; Sun, Xiaofeng

2015-10-01

In order to study the influences of stress and temperature on the creep deformation mechanisms of a newly developed Ni-Co-based superalloy with low stacking fault energy, creep experiments were carried out under a stress range of 345 to 840 MPa and a temperature range of 923 K to 1088 K (650 °C to 815 °C). The mechanisms operated under the various creep conditions were identified and the reasons for their transformation were well discussed. A deformation mechanism map under different creep conditions was summarized, which provides a qualitative representation of the operative creep mechanisms as a function of stress and temperature.

Performance of PEM fuel cells stack as affected by number of cell and gas flow-rate

NASA Astrophysics Data System (ADS)

Syampurwadi, A.; Onggo, H.; Indriyati; Yudianti, R.

2017-03-01

The proton exchange membrane fuel cell (PEMFC) is a promising technology as an alternative green energy due to its high power density, low operating temperatures, low local emissions, quiet operation and fast start up-shutdown. In order to apply fuel cell as portable power supply, the performance investigation of small number of cells is needed. In this study, PEMFC stacks consisting of 1, 3, 5 and 7-cells with an active area of 25 cm2 per cell have been designed and developed. Their was evaluated in variation of gas flow rate. The membrane electrode assembly (MEA) was prepared by hot-pressing commercial gas diffusion electrodes (Pt loading 0.5 mg/cm2) on pre-treated Nafion 117 membrane. The stacks were constructed using bipolar plates in serpentine pattern and Z-type gas flow configuration. The experimental results were presented as polarization and power output curves which show the effects of varying number of cells and H2/O2 flow-rates on the PEMFC performance. The experimental results showed that not only number of cells and gas flow-rates affected the fuel cells performance, but also the operating temperature as a result of electrochemistry reaction inside the cell.

Portable DMFC system with methanol sensor-less control

NASA Astrophysics Data System (ADS)

Chen, C. Y.; Liu, D. H.; Huang, C. L.; Chang, C. L.

This work develops a prototype 20 W portable DMFC by system integration of stack, condenser, methanol sensor-less control and start-up characteristics. The effects of these key components and control schemes on the performance are also discussed. To expedite the use of portable DMFC in electronic applications, the system utilizes a novel methanol sensor-less control method, providing improved fuel efficiency, durability, miniaturization and cost reduction. The operating characteristics of the DMFC stack are applied to control the fuel ejection time and period, enabling the system to continue operating even when the MEAs of the stack are deteriorated. The portable system is also designed with several features including water balance and quick start-up (in 5 min). Notably, the proposed system using methanol sensor-less control with injection of pure methanol can power the DVD player and notebook PC. The system specific energy and energy density following three days of operation are 362 Wh kg -1 and 335 Wh L -1, respectively, which are better than those of lithium batteries (∼150 Wh kg -1 and ∼250 Wh L -). This good energy storage feature demonstrates that the portable DMFC is likely to be valuable in computer, communication and consumer electronic (3C) markets.

Monitoring CO 2 Storage at Cranfield, Mississippi with Time-Lapse Offset VSP – Using Integration and Modeling to Reduce Uncertainty

DOE PAGES

Daley, Thomas M.; Hendrickson, Joel; Queen, John H.

2014-12-31

A time-lapse Offset Vertical Seismic Profile (OVSP) data set was acquired as part of a subsurface monitoring program for geologic sequestration of CO 2. The storage site at Cranfield, near Natchez, Mississippi, is part of a detailed area study (DAS) site for geologic carbon sequestration operated by the U.S. Dept. of Energy’s Southeast Regional Carbon Sequestration Partnership (SECARB). The DAS site includes three boreholes, an injection well and two monitoring wells. The project team selected the DAS site to examine CO 2 sequestration multiphase fluid flow and pressure at the interwell scale in a brine reservoir. The time-lapse (TL) OVSPmore » was part of an integrated monitoring program that included well logs, crosswell seismic, electrical resistance tomography and 4D surface seismic. The goals of the OVSP were to detect the CO 2 induced change in seismic response, give information about the spatial distribution of CO 2 near the injection well and to help tie the high-resolution borehole monitoring to the 4D surface data. The VSP data were acquired in well CFU 31-F1, which is the ~3200 m deep CO 2 injection well at the DAS site. A preinjection survey was recorded in late 2009 with injection beginning in December 2009, and a post injection survey was conducted in Nov 2010 following injection of about 250 kT of CO 2. The sensor array for both surveys was a 50-level, 3-component, Sercel MaxiWave system with 15 m (49 ft) spacing between levels. The source for both surveys was an accelerated weight drop, with different source trucks used for the two surveys. Consistent time-lapse processing was applied to both data sets. Time-lapse processing generated difference corridor stacks to investigate CO 2 induced reflection amplitude changes from each source point. Corridor stacks were used for amplitude analysis to maximize the signal-to-noise ratio (S/N) for each shot point. Spatial variation in reflectivity (used to ‘map’ the plume) was similar in magnitude to the corridor stacks but, due to relatively lower S/N, the results were less consistent and more sensitive to processing and therefore are not presented. We examined the overall time-lapse repeatability of the OVSP data using three methods, the NRMS and Predictability (Pred) measures of Kragh and Christie (2002) and the signal-to-distortion ratio (SDR) method of Cantillo (2011). Because time-lapse noise was comparable to the observed change, multiple methods were used to analyze data reliability. The reflections from the top and base reservoir were identified on the corridor stacks by correlation with a synthetic response generated from the well logs. A consistent change in the corridor stack amplitudes from pre- to post-CO 2 injection was found for both the top and base reservoir reflections on all ten shot locations analyzed. In addition to the well-log synthetic response, a finite-difference elastic wave propagation model was built based on rock/fluid properties obtained from well logs, with CO 2 induced changes guided by time-lapse crosswell seismic tomography (Ajo-Franklin, et al., 2013) acquired at the DAS site. Time-lapse seismic tomography indicated that two reservoir zones were affected by the flood. The modeling established that interpretation of the VSP trough and peak event amplitudes as reflectivity from the top and bottom of reservoir is appropriate even with possible tuning effects. Importantly, this top/base change gives confidence in an interpretation that these changes arise from within the reservoir, not from bounding lithology. The modeled time-lapse change and the observed field data change from 10 shotpoints are in agreement for both magnitude and polarity of amplitude change for top and base of reservoir. Therefore, we conclude the stored CO 2 has been successfully detected and, furthermore, the observed seismic reflection change can be applied to Cranfield’s 4D surface seismic for spatially delineating the CO 2/brine interface.« less

Note: A short-pulse high-intensity molecular beam valve based on a piezoelectric stack actuator

NASA Astrophysics Data System (ADS)

Abeysekera, Chamara; Joalland, Baptiste; Shi, Yuanyuan; Kamasah, Alexander; Oldham, James M.; Suits, Arthur G.

2014-11-01

Solenoid and piezoelectric disk valves, which are widely used to generate molecular beam pulses, still suffer from significant restrictions, such as pulse durations typically >50 μs, low repetition rates, and limited gas flows and operational times. Much of this arises owing to the limited forces these actuators can achieve. To overcome these limitations, we have developed a new pulsed valve based on a high-force piezoelectric stack actuator. We show here that operation with pulse durations as low as 20 μs and repetition rates up to 100 Hz can be easily achieved by operating the valve in conjunction with a commercial fast high-voltage switch. We outline our design and demonstrate its performance with molecular beam characterization via velocity map ion imaging.

Note: a short-pulse high-intensity molecular beam valve based on a piezoelectric stack actuator.

PubMed

Abeysekera, Chamara; Joalland, Baptiste; Shi, Yuanyuan; Kamasah, Alexander; Oldham, James M; Suits, Arthur G

2014-11-01

Solenoid and piezoelectric disk valves, which are widely used to generate molecular beam pulses, still suffer from significant restrictions, such as pulse durations typically >50 μs, low repetition rates, and limited gas flows and operational times. Much of this arises owing to the limited forces these actuators can achieve. To overcome these limitations, we have developed a new pulsed valve based on a high-force piezoelectric stack actuator. We show here that operation with pulse durations as low as 20 μs and repetition rates up to 100 Hz can be easily achieved by operating the valve in conjunction with a commercial fast high-voltage switch. We outline our design and demonstrate its performance with molecular beam characterization via velocity map ion imaging.

MICROPROCESSOR-BASED DATA-ACQUISITION SYSTEM FOR A BOREHOLE RADAR.

USGS Publications Warehouse

Bradley, Jerry A.; Wright, David L.

1987-01-01

An efficient microprocessor-based system is described that permits real-time acquisition, stacking, and digital recording of data generated by a borehole radar system. Although the system digitizes, stacks, and records independently of a computer, it is interfaced to a desktop computer for program control over system parameters such as sampling interval, number of samples, number of times the data are stacked prior to recording on nine-track tape, and for graphics display of the digitized data. The data can be transferred to the desktop computer during recording, or it can be played back from a tape at a latter time. Using the desktop computer, the operator observes results while recording data and generates hard-copy graphics in the field. Thus, the radar operator can immediately evaluate the quality of data being obtained, modify system parameters, study the radar logs before leaving the field, and rerun borehole logs if necessary. The system has proven to be reliable in the field and has increased productivity both in the field and in the laboratory.

Electrical Generation for More-Electric Aircraft Using Solid Oxide Fuel Cells

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

Whyatt, Greg A.; Chick, Lawrence A.

This report examines the potential for Solid-Oxide Fuel Cells (SOFC) to provide electrical generation on-board commercial aircraft. Unlike a turbine-based auxiliary power unit (APU) a solid oxide fuel cell power unit (SOFCPU) would be more efficient than using the main engine generators to generate electricity and would operate continuously during flight. The focus of this study is on more-electric aircraft which minimize bleed air extraction from the engines and instead use electrical power obtained from generators driven by the main engines to satisfy all major loads. The increased electrical generation increases the potential fuel savings obtainable through more efficient electricalmore » generation using a SOFCPU. However, the weight added to the aircraft by the SOFCPU impacts the main engine fuel consumption which reduces the potential fuel savings. To investigate these relationships the Boeing 787­8 was used as a case study. The potential performance of the SOFCPU was determined by coupling flowsheet modeling using ChemCAD software with a stack performance algorithm. For a given stack operating condition (cell voltage, anode utilization, stack pressure, target cell exit temperature), ChemCAD software was used to determine the cathode air rate to provide stack thermal balance, the heat exchanger duties, the gross power output for a given fuel rate, the parasitic power for the anode recycle blower and net power obtained from (or required by) the compressor/expander. The SOFC is based on the Gen4 Delphi planar SOFC with assumed modifications to tailor it to this application. The size of the stack needed to satisfy the specified condition was assessed using an empirically-based algorithm. The algorithm predicts stack power density based on the pressure, inlet temperature, cell voltage and anode and cathode inlet flows and compositions. The algorithm was developed by enhancing a model for a well-established material set operating at atmospheric pressure to reflect the effect of elevated pressure and to represent the expected enhancement obtained using a promising cell material set which has been tested in button cells but not yet used to produce full-scale stacks. The predictions for the effect of pressure on stack performance were based on literature. As part of this study, additional data were obtained on button cells at elevated pressure to confirm the validity of the predictions. The impact of adding weight to the 787-8 fuel consumption was determined as a function of flight distance using a PianoX model. A conceptual design for a SOFC power system for the Boeing 787 is developed and the weight estimated. The results indicate that the power density of the stacks must increase by at least a factor of 2 to begin saving fuel on the 787 aircraft. However, the conceptual design of the power system may still be useful for other applications which are less weight sensitive.« less

Direct fuel cell power plants: the final steps to commercialization

NASA Astrophysics Data System (ADS)

Glenn, Donald R.

Since the last paper presented at the Second Grove Fuel Cell Symposium, the Energy Research Corporation (ERC) has established two commercial subsidiaries, become a publically-held firm, expanded its facilities and has moved the direct fuel cell (DFC) technology and systems significantly closer to commercial readiness. The subsidiaries, the Fuel Cell Engineering Corporation (FCE) and Fuel Cell Manufacturing Corporation (FCMC) are perfecting their respective roles in the company's strategy to commercialize its DFC technology. FCE is the prime contractor for the Santa Clara Demonstration and is establishing the needed marketing, sales, engineering, and servicing functions. FCMC in addition to producing the stacks and stack modules for the Santa Clara demonstration plant is now upgrading its production capability and product yields, and retooling for the final stack scale-up for the commercial unit. ERC has built and operated the tallest and largest capacities-to-date carbonate fuel cell stacks as well as numerous short stacks. While most of these units were tested at ERC's Danbury, Connecticut (USA) R&D Center, others have been evaluated at other domestic and overseas facilities using a variety of fuels. ERC has supplied stacks to Elkraft and MTU for tests with natural gas, and RWE in Germany where coal-derived gas were used. Additional stack test activities have been performed by MELCO and Sanyo in Japan. Information from some of these activities is protected by ERC's license arrangements with these firms. However, permission for limited data releases will be requested to provide the Grove Conference with up-to-date results. Arguably the most dramatic demonstration of carbonate fuel cells in the utility-scale, 2 MW power plant demonstration unit, located in the City of Santa Clara, California. Construction of the unit's balance-of-plant (BOP) has been completed and the installed equipment has been operationally checked. Two of the four DFC stack sub-modules, each rated at 500 kW, are on-site and will be installed to the BOP upon completion of the BOP pretests now in the final stages. Full operation and commencement of the formal demonstration is to begin late this year. Now five years old, the Fuel Cell Commercialization Group (FCCG) has grown to include over 30 buyers. The Group's Committees have been actively working with FCE personnel to hone the plant's performance, configuration and cost/benefit trade-offs to assure a market-responsive unit results from the collaboration. A standard contract has been developed for use with the FCCG buyers to streamline the purchase agreement negotiations for the early units. These are essential steps to support a market entry for the 2.8 MW power plant in 1999. The paper details the program's progress and provides additional information on the current demonstration and stack test efforts, with comparisons to earlier test data. Recent accomplishments and planned efforts to affect market entry of the first production units is reviewed as well.

Real-time monitoring of emissions from monoethanolamine-based industrial scale carbon capture facilities.

PubMed

Zhu, Liang; Schade, Gunnar Wolfgang; Nielsen, Claus Jørgen

2013-12-17

We demonstrate the capabilities and properties of using Proton Transfer Reaction time-of-flight mass spectrometry (PTR-ToF-MS) to real-time monitor gaseous emissions from industrial scale amine-based carbon capture processes. The benchmark monoethanolamine (MEA) was used as an example of amines needing to be monitored from carbon capture facilities, and to describe how the measurements may be influenced by potentially interfering species in CO2 absorber stack discharges. On the basis of known or expected emission compositions, we investigated the PTR-ToF-MS MEA response as a function of sample flow humidity, ammonia, and CO2 abundances, and show that all can exhibit interferences, thus making accurate amine measurements difficult. This warrants a proper sample pretreatment, and we show an example using a dilution with bottled zero air of 1:20 to 1:10 to monitor stack gas concentrations at the CO2 Technology Center Mongstad (TCM), Norway. Observed emissions included many expected chemical species, dominantly ammonia and acetaldehyde, but also two new species previously not reported but emitted in significant quantities. With respect to concerns regarding amine emissions, we show that accurate amine quantifications in the presence of water vapor, ammonia, and CO2 become feasible after proper sample dilution, thus making PTR-ToF-MS a viable technique to monitor future carbon capture facility emissions, without conventional laborious sample pretreatment.

40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?

Code of Federal Regulations, 2010 CFR

2010-07-01

... activated carbon? If your municipal waste combustion unit uses activated carbon to control dioxins/furans or... dioxins/furans and mercury stack test, determine the average carbon feed rate in kilograms (or pounds) per...

40 CFR 62.15275 - How do I monitor the injection rate of activated carbon?

Code of Federal Regulations, 2010 CFR

2010-07-01

... carbon? If your municipal waste combustion unit uses activated carbon to control dioxins/furans or... dioxins/furans and mercury stack test, determine the average carbon feed rate in kilograms (or pounds) per...

40 CFR 60.1330 - How do I monitor the injection rate of activated carbon?

Code of Federal Regulations, 2010 CFR

2010-07-01

... combustion unit uses activated carbon to control dioxins/furans or mercury emissions, you must meet three... feed rate (for example, screw feeder speed). (b) During each dioxins/furans and mercury stack test...

Increasing Update Rates in the Building Walkthrough System with Automatic Model-Space Subdivision and Potentially Visible Set Calculations

DTIC Science & Technology

1990-07-01

34 ACM Computing Surveys. 6(1): 1- 55. [Syzmanski85] Syzmanski, T. G. and C. J. V. Wyk. (1985). " GOALIE : A Space Efficient System for VLSI Artwork...this. Essentially we initialize a stack with the root. We then pull an element of this stack and if it is a cell we run the occlusion operation on the

Develop and test fuel cell powered on-site integrated total energy systems. Phase 3: Full-scale power plant development

NASA Technical Reports Server (NTRS)

Feigenbaum, H.; Kaufman, A.; Wang, C. L.; Werth, J.; Whelan, J. A.

1983-01-01

Operating experience with a 5kW methanol-air integrated system is described. On-going test results for a 24-cell, two-sq ft (4kW) stack are reported. The main activity for this stack is currently the evaluation of developmental non-metalic cooling plates. Single-cell test results are presented for a promising developmental cathode catalyst.

Phosphoric and electric utility fuel technology development

NASA Astrophysics Data System (ADS)

Breault, R. D.; Briggs, T. A.; Congdon, J. V.; Gelting, R. L.; Goller, G. J.; Luoma, W. L.; McCloskey, M. W.; Mientek, A. P.; Obrien, J. J.; Randall, S. A.

1985-05-01

Seventeen hundred hours and 11 thermal cycles were accumulated on the second 10 sq ft short stack at 120 psia and 405 F. A subscale cell out from 10 sq ft electrodes in the same batch used for the second 10 sq ft short stack accumulated over 4100 hours with performance conforming close to the E-line goal at 120 psia and 400 F. Over 14,870 hours and 42 thermal cycles were accumulated on the 3.7 sq ft, 30-cell short stack at 120 psia and 405 F. A subscale cell with GSB-18 catalyst completed over 10,000 hours of operation at 120 psia, 400 F. The full-size, 10 sq ft stack containment vessel and reactant gas manifolds were observed. The improved edge seal decreased leakage by more than 50% from the conventional edge seal. Cross-pressure tolerance also improved. Continuous automatic operation of the substrate forming machine was demonstrated by producing substrates at a 50% faster rate with high yields and low material loss. The cooler bonding cycle was significantly reduced by using a cold press in conjunction with the hot press. A lower cost stainless steel tubing is identified that could reduce cooler array cost by up to 50%. Assembly of the automated cell fill and assembly machine is initiated.

An experimental investigation of thermoacoustic lasers operating in audible frequency range

NASA Astrophysics Data System (ADS)

Kolhe, Sanket Anil

Thermoacoustic lasers convert heat from a high-temperature heat source into acoustic power while rejecting waste heat to a low temperature sink. The working fluids involved can be air or noble gases which are nontoxic and environmentally benign. Simple in construction due to absence of moving parts, thermoacoustic lasers can be employed to achieve generation of electricity at individual homes, water-heating for domestic purposes, and to facilitate space heating and cooling. The possibility of utilizing waste heat or solar energy to run thermoacoustic devices makes them technically promising and economically viable to generate large quantities of acoustic energy. The research presented in this thesis deals with the effects of geometric parameters (stack position, stack length, tube length) associated with a thermoacoustic laser on the output sound wave. The effects of varying input power on acoustic output were also studied. Based on the experiments, optimum operating conditions were identified and qualitative and/or quantitative explanations were provided to justify our observations. It was observed that the maximum sound pressure level was generated for the laser with the stack positioned at a distance of quarter lengths of a resonator from the closed end. Higher sound pressure levels were recorded for the laser with longer stack lengths and longer resonator lengths. Efforts were also made to develop high-frequency thermoacoustic lasers.

Post-test characterization of a solid oxide fuel cell stack operated for more than 30,000 hours: The cell

NASA Astrophysics Data System (ADS)

Menzler, Norbert H.; Sebold, Doris; Guillon, Olivier

2018-01-01

A four-layer solid oxide fuel cell stack with planar anode-supported cells was operated galvanostatically at 700 °C and 0.5Acm-2 for nearly 35,000 h. One of the four planes started to degrade more rapidly after ∼28,000 h and finally more progressively after ∼33,000 h. The stack was then shut down and a post-test analysis was carefully performed. The cell was characterized with respect to cathodic impurities and clarification of the reason(s) for failure. Wet chemical analysis revealed very low chromium incorporation into the cathode. However, SEM and TEM observations on polished and fractured surfaces showed catastrophic failure in the degraded layer. The cathode-barrier-electrolyte cell layer system delaminated from the entire cell over large areas. The source of delamination was the formation of a porous, sponge-like secondary phase consisting of zirconia, yttria and manganese (oxide). Large secondary phase islands grew from the electrolyte-anode interface towards the anode and cracked the bonding between both layers. The manganese originated from the contact or protection layers used on the air side. This stack result shows that volatile species - in this case manganese - should be avoided, especially when long-term applications are envisaged.

Transformation diffusion reconstruction of three-dimensional histology volumes from two-dimensional image stacks.

PubMed

Casero, Ramón; Siedlecka, Urszula; Jones, Elizabeth S; Gruscheski, Lena; Gibb, Matthew; Schneider, Jürgen E; Kohl, Peter; Grau, Vicente

2017-05-01

Traditional histology is the gold standard for tissue studies, but it is intrinsically reliant on two-dimensional (2D) images. Study of volumetric tissue samples such as whole hearts produces a stack of misaligned and distorted 2D images that need to be reconstructed to recover a congruent volume with the original sample's shape. In this paper, we develop a mathematical framework called Transformation Diffusion (TD) for stack alignment refinement as a solution to the heat diffusion equation. This general framework does not require contour segmentation, is independent of the registration method used, and is trivially parallelizable. After the first stack sweep, we also replace registration operations by operations in the space of transformations, several orders of magnitude faster and less memory-consuming. Implementing TD with operations in the space of transformations produces our Transformation Diffusion Reconstruction (TDR) algorithm, applicable to general transformations that are closed under inversion and composition. In particular, we provide formulas for translation and affine transformations. We also propose an Approximated TDR (ATDR) algorithm that extends the same principles to tensor-product B-spline transformations. Using TDR and ATDR, we reconstruct a full mouse heart at pixel size 0.92µm×0.92µm, cut 10µm thick, spaced 20µm (84G). Our algorithms employ only local information from transformations between neighboring slices, but the TD framework allows theoretical analysis of the refinement as applying a global Gaussian low-pass filter to the unknown stack misalignments. We also show that reconstruction without an external reference produces large shape artifacts in a cardiac specimen while still optimizing slice-to-slice alignment. To overcome this problem, we use a pre-cutting blockface imaging process previously developed by our group that takes advantage of Brewster's angle and a polarizer to capture the outline of only the topmost layer of wax in the block containing embedded tissue for histological sectioning. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Thermodynamic Simulation of Equilibrium Composition of Reaction Products at Dehydration of a Technological Channel in a Uranium-Graphite Reactor

NASA Astrophysics Data System (ADS)

Pavliuk, A. O.; Zagumennov, V. S.; Kotlyarevskiy, S. G.; Bespala, E. V.

2018-01-01

The problems of accumulation of nuclear fuel spills in the graphite stack in the course of operation of uranium-graphite nuclear reactors are considered. The results of thermodynamic analysis of the processes in the graphite stack at dehydration of a technological channel, fuel element shell unsealing and migration of fission products, and activation of stable nuclides in structural elements of the reactor and actinides inside the graphite moderator are given. The main chemical reactions and compounds that are produced in these modes in the reactor channel during its operation and that may be hazardous after its shutdown and decommissioning are presented. Thermodynamic simulation of the equilibrium composition is performed using the specialized code TERRA. The results of thermodynamic simulation of the equilibrium composition in different cases of technological channel dehydration in the course of the reactor operation show that, if the temperature inside the active core of the nuclear reactor increases to the melting temperature of the fuel element, oxides and carbides of nuclear fuel are produced. The mathematical model of the nonstationary heat transfer in a graphite stack of a uranium-graphite reactor in the case of the technological channel dehydration is presented. The results of calculated temperature evolution at the center of the fuel element, the replaceable graphite element, the air gap, and in the surface layer of the block graphite are given. The numerical results show that, in the case of dehydration of the technological channel in the uranium-graphite reactor with metallic uranium, the main reaction product is uranium dioxide UO2 in the condensed phase. Low probability of production of pyrophoric uranium compounds (UH3) in the graphite stack is proven, which allows one to disassemble the graphite stack without the risk of spontaneous graphite ignition in the course of decommissioning of the uranium-graphite nuclear reactor.

40 CFR 61.33 - Stack sampling.

Code of Federal Regulations, 2014 CFR

2014-07-01

... which has an initial startup date preceding February 27, 2014; or (2) Within 90 days of startup in the case of a new source which did not have an initial startup date preceding February 27, 2014. (b) The... relative frequency of operation of different types of processes, operating hours, operating capacities, or...

Electrical power from sea and river water by reverse electrodialysis: a first step from the laboratory to a real power plant.

PubMed

Veerman, Joost; Saakes, Michel; Metz, Sybrand J; Harmsen, G Jan

2010-12-01

Electricity can be produced directly with reverse electrodialysis (RED) from the reversible mixing of two solutions of different salinity, for example, sea and river water. The literature published so far on RED was based on experiments with relatively small stacks with cell dimensions less than 10 × 10 cm(2). For the implementation of the RED technique, it is necessary to know the challenges associated with a larger system. In the present study we show the performance of a scaled-up RED stack, equipped with 50 cells, each measuring 25 × 75 cm(2). A single cell consists of an AEM (anion exchange membrane) and a CEM (cation exchange membrane) and therefore, the total active membrane area in the stack is 18.75 m(2). This is the largest dimension of a reverse electrodialysis stack published so far. By comparing the performance of this stack with a small stack (10 × 10 cm(2), 50 cells) it was found that the key performance parameter to maximal power density is the hydrodynamic design of the stack. The power densities of the different stacks depend on the residence time of the fluids in the stack. For the large stack this was negatively affected by the increased hydrodynamic losses due to the longer flow path. It was also found that the large stack generated more power when the sea and river water were flowing in co-current operation. Co-current flow has other advantages, the local pressure differences between sea and river water compartments are low, hence preventing leakage around the internal manifolds and through pinholes in the membranes. Low pressure differences also enable the use of very thin membranes (with low electrical resistance) as well as very open spacers (with low hydrodynamic losses) in the future. Moreover, we showed that the use of segmented electrodes increase the power output by 11%.

A new information architecture, website and services for the CMS experiment

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

Taylor, Lucas; Rusack, Eleanor; Zemleris, Vidmantas

2012-01-01

The age and size of the CMS collaboration at the LHC means it now has many hundreds of inhomogeneous web sites and services, and hundreds of thousands of documents. We describe a major initiative to create a single coherent CMS internal and public web site. This uses the Drupal web Content Management System (now supported by CERN/IT) on top of a standard LAMP stack (Linux, Apache, MySQL, and php/perl). The new navigation, content and search services are coherently integrated with numerous existing CERN services (CDS, EDMS, Indico, phonebook, Twiki) as well as many CMS internal Web services. We describe themore » information architecture, the system design, implementation and monitoring, the document and content database, security aspects, and our deployment strategy, which ensured continual smooth operation of all systems at all times.« less

A new Information Architecture, Website and Services for the CMS Experiment

NASA Astrophysics Data System (ADS)

Taylor, Lucas; Rusack, Eleanor; Zemleris, Vidmantas

2012-12-01

The age and size of the CMS collaboration at the LHC means it now has many hundreds of inhomogeneous web sites and services, and hundreds of thousands of documents. We describe a major initiative to create a single coherent CMS internal and public web site. This uses the Drupal web Content Management System (now supported by CERN/IT) on top of a standard LAMP stack (Linux, Apache, MySQL, and php/perl). The new navigation, content and search services are coherently integrated with numerous existing CERN services (CDS, EDMS, Indico, phonebook, Twiki) as well as many CMS internal Web services. We describe the information architecture; the system design, implementation and monitoring; the document and content database; security aspects; and our deployment strategy, which ensured continual smooth operation of all systems at all times.

KSC-2013-3728

NASA Image and Video Library

2013-10-22

CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, technicians monitor the progress as the Orion ground test vehicle, or GTA, is lowered by crane toward a mockup of the service module in high bay 4 of the Vehicle Assembly Building. The ground test vehicle is being used for path finding operations, including simulated manufacturing, assembly and stacking procedures. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted test flight of Orion is scheduled to launch in 2014 atop a Delta IV rocket and in 2017 on NASA’s Space Launch System rocket. For more information, visit www.nasa.gov/orion. Photo credit: Dimitri Gerondidakis

KSC-2013-3727

NASA Image and Video Library

2013-10-22

CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, technicians monitor the progress as the Orion ground test vehicle, or GTA, is being lowered by crane toward a mockup of the service module in high bay 4 of the Vehicle Assembly Building. The ground test vehicle is being used for path finding operations, including simulated manufacturing, assembly and stacking procedures. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted test flight of Orion is scheduled to launch in 2014 atop a Delta IV rocket and in 2017 on NASA’s Space Launch System rocket. For more information, visit www.nasa.gov/orion. Photo credit: Dimitri Gerondidakis

Domestic wastewater treatment and power generation in continuous flow air-cathode stacked microbial fuel cell: Effect of series and parallel configuration.

PubMed

Estrada-Arriaga, Edson Baltazar; Hernández-Romano, Jesús; García-Sánchez, Liliana; Guillén Garcés, Rosa Angélica; Bahena-Bahena, Erick Obed; Guadarrama-Pérez, Oscar; Moeller Chavez, Gabriela Eleonora

2018-05-15

In this study, a continuous flow stack consisting of 40 individual air-cathode MFC units was used to determine the performance of stacked MFC during domestic wastewater treatment operated with unconnected individual MFC and in series and parallel configuration. The voltages obtained from individual MFC units were of 0.08-1.1 V at open circuit voltage, while in series connection, the maximum power and current density were 2500 mW/m 2 and 500 mA/m 2 (4.9 V), respectively. In parallel connection, the maximum power and current density was 5.8 mW/m 2 and 24 mA/m 2 , respectively. When the cells were not connected to each other MFC unit, the main bacterial species found in the anode biofilms were Bacillus and Lysinibacillus. After switching from unconnected to series and parallel connections, the most abundant species in the stacked MFC were Pseudomonas aeruginosa, followed by different Bacilli classes. This study demonstrated that when the stacked MFC was switched from unconnected to series and parallel connections, the pollutants removal, performance electricity and microbial community changed significantly. Voltages drops were observed in the stacked MFC, which was mainly limited by the cathodes. These voltages loss indicated high resistances within the stacked MFC, generating a parasitic cross current. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

Wheeler, Douglas; Ulsh, Michael

The results of two Manufacturing Readiness Assessments of PEM fuel cell stacks and material handling equipment (MHE) and backup power (BUP) PEM fuel cell systems are given. Design modifications of fuel cell systems were made because the initial, 2008 designs did not fully meet the operational requirements of the markets. This situation indicates the 2008 risk elements were overstated.For 2010 BUP and MHE fuel cell systems, manufacturers had not reached the Low Rate Initial Production (LRIP) defined in the 2008 MRA Report at 1,000 units per year per manufacturer.For fuel cell stacks, LRIP was demonstrated by more than one manufacturer.Themore » federal tax incentive program has compensated for the initial high cost of fuel cell systems.The Balance-of-Plant (BOP) has not evolved as rapidly as the PEM fuel cell stack manufacturing readiness.The BOP in 2014 is as costly as the fuel cell stack for MHE applications.« less

Low voltage to high voltage level shifter and related methods

NASA Technical Reports Server (NTRS)

Mentze, Erik J. (Inventor); Buck, Kevin M. (Inventor); Hess, Herbert L. (Inventor); Cox, David F. (Inventor)

2006-01-01

A shifter circuit comprises a high and low voltage buffer stages and an output buffer stage. The high voltage buffer stage comprises multiple transistors arranged in a transistor stack having a plurality of intermediate nodes connecting individual transistors along the stack. The transistor stack is connected between a voltage level being shifted to and an input voltage. An inverter of this stage comprises multiple inputs and an output. Inverter inputs are connected to a respective intermediate node of the transistor stack. The low voltage buffer stage has an input connected to the input voltage and an output, and is operably connected to the high voltage buffer stage. The low voltage buffer stage is connected between a voltage level being shifted away from and a lower voltage. The output buffer stage is driven by the outputs of the high voltage buffer stage inverter and the low voltage buffer stage.

Unitized regenerative fuel cell system

NASA Technical Reports Server (NTRS)

Burke, Kenneth A. (Inventor)

2008-01-01

A Unitized Regenerative Fuel Cell system uses heat pipes to convey waste heat from the fuel cell stack to the reactant storage tanks. The storage tanks act as heat sinks/sources and as passive radiators of the waste heat from the fuel cell stack. During charge up, i.e., the electrolytic process, gases are conveyed to the reactant storage tanks by way of tubes that include dryers. Reactant gases moving through the dryers give up energy to the cold tanks, causing water vapor in with the gases to condense and freeze on the internal surfaces of the dryer. During operation in its fuel cell mode, the heat pipes convey waste heat from the fuel cell stack to the respective reactant storage tanks, thereby heating them such that the reactant gases, as they pass though the respective dryers on their way to the fuel cell stacks retrieve the water previously removed.

Method to improve reliability of a fuel cell system using low performance cell detection at low power operation

DOEpatents

Choi, Tayoung; Ganapathy, Sriram; Jung, Jaehak; Savage, David R.; Lakshmanan, Balasubramanian; Vecasey, Pamela M.

2013-04-16

A system and method for detecting a low performing cell in a fuel cell stack using measured cell voltages. The method includes determining that the fuel cell stack is running, the stack coolant temperature is above a certain temperature and the stack current density is within a relatively low power range. The method further includes calculating the average cell voltage, and determining whether the difference between the average cell voltage and the minimum cell voltage is greater than a predetermined threshold. If the difference between the average cell voltage and the minimum cell voltage is greater than the predetermined threshold and the minimum cell voltage is less than another predetermined threshold, then the method increments a low performing cell timer. A ratio of the low performing cell timer and a system run timer is calculated to identify a low performing cell.

Ares I-X Flight Test Vehicle: Stack 5 Modal Test

NASA Technical Reports Server (NTRS)

Buehrle, Ralph D.; Templeton, Justin D.; Reaves, Mercedes C.; Horta, Lucas G.; Gaspar, James L.; Bartolotta, Paul A.; Parks, Russel A.; Lazor, Danel R.

2010-01-01

Ares I-X was the first flight test vehicle used in the development of NASA's Ares I crew launch vehicle. The Ares I-X used a 4-segment reusable solid rocket booster from the Space Shuttle heritage with mass simulators for the 5th segment, upper stage, crew module and launch abort system. Three modal tests were defined to verify the dynamic finite element model of the Ares I-X flight test vehicle. Test configurations included two partial stacks and the full Ares I-X flight test vehicle on the Mobile Launcher Platform. This report focuses on the first modal test that was performed on the top section of the vehicle referred to as Stack 5, which consisted of the spacecraft adapter, service module, crew module and launch abort system simulators. This report describes the test requirements, constraints, pre-test analysis, test operations and data analysis for the Ares I-X Stack 5 modal test.

Ares I-X Flight Test Vehicle:Stack 1 Modal Test

NASA Technical Reports Server (NTRS)

Buehrle, Ralph D.; Templeton, Justin D.; Reaves, Mercedes C.; Horta, Lucas G.; Gaspar, James L.; Bartolotta, Paul A.; Parks, Russel A.; Lazor, Daniel R.

2010-01-01

Ares I-X was the first flight test vehicle used in the development of NASA s Ares I crew launch vehicle. The Ares I-X used a 4-segment reusable solid rocket booster from the Space Shuttle heritage with mass simulators for the 5th segment, upper stage, crew module and launch abort system. Three modal tests were defined to verify the dynamic finite element model of the Ares I-X flight test vehicle. Test configurations included two partial stacks and the full Ares I-X flight test vehicle on the Mobile Launcher Platform. This report focuses on the second modal test that was performed on the middle section of the vehicle referred to as Stack 1, which consisted of the subassembly from the 5th segment simulator through the interstage. This report describes the test requirements, constraints, pre-test analysis, test operations and data analysis for the Ares I-X Stack 1 modal test.

Spectral gain profile of a multi-stack terahertz quantum cascade laser

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

Bachmann, D., E-mail: dominic.bachmann@tuwien.ac.at; Deutsch, C.; Krall, M.

2014-11-03

The spectral gain of a multi-stack terahertz quantum cascade laser, composed of three active regions with emission frequencies centered at 2.3, 2.7, and 3.0 THz, is studied as a function of driving current and temperature using terahertz time-domain spectroscopy. The optical gain associated with the particular quantum cascade stacks clamps at different driving currents and saturates to different values. We attribute these observations to varying pumping efficiencies of the respective upper laser states and to frequency dependent optical losses. The multi-stack active region exhibits a spectral gain full width at half-maximum of 1.1 THz. Bandwidth and spectral position of themore » measured gain match with the broadband laser emission. As the laser action ceases with increasing operating temperature, the gain at the dominant lasing frequency of 2.65 THz degrades sharply.« less

MSuPDA: A memory efficient algorithm for sequence alignment.

PubMed

Khan, Mohammad Ibrahim; Kamal, Md Sarwar; Chowdhury, Linkon

2015-01-16

Space complexity is a million dollar question in DNA sequence alignments. In this regards, MSuPDA (Memory Saving under Pushdown Automata) can help to reduce the occupied spaces in computer memory. Our proposed process is that Anchor Seed (AS) will be selected from given data set of Nucleotides base pairs for local sequence alignment. Quick Splitting (QS) techniques will separate the Anchor Seed from all the DNA genome segments. Selected Anchor Seed will be placed to pushdown Automata's (PDA) input unit. Whole DNA genome segments will be placed into PDA's stack. Anchor Seed from input unit will be matched with the DNA genome segments from stack of PDA. Whatever matches, mismatches or Indel, of Nucleotides will be POP from the stack under the control of control unit of Pushdown Automata. During the POP operation on stack it will free the memory cell occupied by the Nucleotide base pair.

The Effect of Initial Irrigation Conditions on Heap Leaching Efficiency

NASA Astrophysics Data System (ADS)

Briseño Arellano, A. D.; Milczarek, M.; Yao, M.; Brusseau, M. L. L.

2017-12-01

Heap leaching is an unsaturated flow metal recovery process, in which mined ore is irrigated with a lixiviant to dissolve metal contained in the ore. The metal is then extracted from solution. Large scale operations involve stacking ore to depths of 6 to 18 meters on pads that may be hundreds of hectares in area. Heterogeneities within the stacked ore can lead to uneven wetting and the formation of preferential flow pathways, which reduces solution contact and lowers metal recovery. Furthermore, mineral dissolution can cause alteration of the porous media structure and loss of ore permeability. Many mine operators believe that slow initial irrigation rates help minimize permeability loss and increase metal recovery rates. However, this phenomenon has not been studied in detail. Experiments were conducted to investigate the effect of varying initial irrigation rates on leach ore stability. These were conducted with large columns (1.5 m high, 0.5 m in diameter) packed with crushed ore samples that are known to have permeability constraints. The columns were highly instrumented to assess potential changes in material properties both spatially and temporally. Water content was measured with three different methods: capacitance soil moisture sensors placed at 20-cm intervals; a neutron probe to periodically log every 30 cm from four different directions; and electrical resistivity sensors to create a 2-dimensional tomography profile of water content over time. Tensiometers were paired with the soil moisture sensors to measure matric suction and characterize moisture retention characteristics. A non-reactive tracer was used to characterize advective-dispersive transport under unsaturated conditions. A dye solution was introduced at the end of each experiment to map preferential pathways. Continuous monitoring of settling at the surface assisted in measuring consolidation and loss in permeability.

ADAPTING FTIR MEASUREMENT TECHNOLOGY TO HOMELAND SECURITY APPLICATIONS

EPA Science Inventory

Open-path Fourier transform infrared (OP-FTIR) sensors have numerous advantages for measuring chemical plumes over wide areas compared to point detection sensors. Extractive FTIR sensors have been used for industrial stack monitoring and are attractive for building ventilation sy...

Contourograph display system for monitoring electrocardiograms

NASA Technical Reports Server (NTRS)

Golden, D. P., Jr.; Maudlin, D. G.; Wolthuis, R. A.

1970-01-01

Electrocardiogram is displayed as a contourogram on the cathode ray tube of a variable-persistence oscilloscope. Each cycle is stacked below its predecessors giving a three dimensional effect. A major change in the signal is apparent as a change in the contourogram pattern.

Finding Malicious Cyber Discussions in Social Media

DTIC Science & Technology

2015-12-11

automatically filter cyber discussions from Stack Exchange, Reddit, and Twitter posts written in English. Criminal hackers often use social media...monitoring hackers on Facebook and in private chat rooms. As a result, system administrators were prepared to counter distributed denial-of-service

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

Crawford, Aladsair J.; Viswanathan, Vilayanur V.; Stephenson, David E.

A robust performance-based cost model is developed for all-vanadium, iron-vanadium and iron chromium redox flow batteries. Systems aspects such as shunt current losses, pumping losses and thermal management are accounted for. The objective function, set to minimize system cost, allows determination of stack design and operating parameters such as current density, flow rate and depth of discharge (DOD). Component costs obtained from vendors are used to calculate system costs for various time frames. A 2 kW stack data was used to estimate unit energy costs and compared with model estimates for the same size electrodes. The tool has been sharedmore » with the redox flow battery community to both validate their stack data and guide future direction.« less

Compact, Lightweight Dual- Frequency Microstrip Antenna Feed for Future Soil Moisture and Sea Surface Salinity Missions

NASA Technical Reports Server (NTRS)

Yueh, Simon H.; Wilson, William J.; Njoku, Eni; Hunter, Don; Dinardo, Steve; Kona, Keerti S.; Manteghi, Majid; Gies, Dennis; Rahmat-Samii, Yahya

2004-01-01

The development of a compact, lightweight, dual frequency antenna feed for future soil moisture and sea surface salinity (SSS) missions is described. The design is based on the microstrip stacked-patch array (MSPA) to be used to feed a large lightweight deployable rotating mesh antenna for spaceborne L-band (approx. 1 GHz) passive and active sensing systems. The design features will also enable applications to airborne sensors operating on small aircrafts. This paper describes the design of stacked patch elements, 16-element array configuration and power-divider beam forming network The test results from the fabrication of stacked patches and power divider were also described.

Evaluation of gas cooling for pressurized phosphoric acid fuel cell stacks

NASA Technical Reports Server (NTRS)

Farooque, M.; Skok, A. J.; Maru, H. C.; Kothmann, R. E.; Harry, R. W.

1983-01-01

Gas cooling is a more reliable, less expensive and a more simple alternative to conventional liquid cooling for heat removal from the phosphoric acid fuel cell (PAFC). The feasibility of gas cooling has already been demonstrated in atmospheric pressure stacks. This paper presents theoretical and experimental investigation of gas cooling for pressurized PAFC. Two approaches to gas cooling, Distributed Gas Cooling (DIGAS) and Separated Gas Cooling (SGC) were considered, and a theoretical comparison on the basis of cell performance indicated SGC to be superior to DIGAS. The feasibility of SGC was experimentally demonstrated by operating a 45-cell stack for 700 hours at pressure, and determining thermal response and the effect of other related parameters.

Fabrication of a prototype dipole for the SSC Low Energy Booster

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

Spencer, C.M.

1993-12-01

The Low Energy Booster of the Superconducting Super Collider (SSC) will be a synchrotron containing 96 dipoles operating between 0.13 T and 1.35 T at 10 Hz. Each dipole`s 1.865 m-long core is made from {approximately}2900 steel laminations (lams), each 52 {times} 66 cm and 0.635 mm thick. A need to minimize power supply costs and stringent field specifications led to a straight core with very tight mechanical tolerances of the order of 0.05 mm. To satisfy these tolerances, we decided to stack the core in a vertical position; i.e., with the laminations laid horizontally. We designed and built anmore » unusual vertical stacking fixture that pivots into a horizontal position after all the laminations have been stacked and compressed and four support angles welded onto the laminations. The stacking fixture, our experience using it, and conclusions as to the merits of stacking such a long core vertically will be described. The methods of insulating and potting the pancake coils and their installation into the unsplittable core is also described.« less

Tubular gage for a liquid-metal-cooled fast breeder reactor

DOEpatents

Hutter, Ernest; Tuma, Leroy A.

1977-06-14

Spring-loaded plungers are arranged about a housing for insertion into a polygonal tube, one plunger for each side of the tube. Each plunger has a locking cam and sliding wedge mechanism which can overcome the spring force associated with the plunger and lock it in any position. The wedges are operated by a rod moveable axially in the housing. Several housings with their associated plungers can be stacked. The stack is lowered into the polygonal tube with all of the plungers locked in a fully inward position. When the stack is in the tube, each wedge is moved to release its locking cam, allowing each of the plungers to spring outward against an inner side of the tube. Each housing will thus gage the internal dimensions of the tube at its elevation. The plungers are locked in position, the entire stack is rotated to bring the plungers into the corners described by the intersections of the flat sides, and the stack is removed from the tube whereupon the dimensions across opposite locked plungers may be read by a micrometer.

The effects of a high-stack coal-burning power plant on the relative pH of the superficial bark of hardwood trees

Treesearch

David F. Grether

1976-01-01

The Allen S. King Generating Plant near Bayport, Minnesota delivers 420 tons of sulfur dioxide to the atmosphere daily from a 789 foot (240 m) stack. Dispersal from this height theoretically minimizes harmful effects of the gases on vegetation. Six years of post-operational pH tests on hardwoods, in the area, show fluctuations in, but no significant increase of the...

Note: A short-pulse high-intensity molecular beam valve based on a piezoelectric stack actuator

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

Abeysekera, Chamara; Joalland, Baptiste; Shi, Yuanyuan

2014-11-15

Solenoid and piezoelectric disk valves, which are widely used to generate molecular beam pulses, still suffer from significant restrictions, such as pulse durations typically >50 μs, low repetition rates, and limited gas flows and operational times. Much of this arises owing to the limited forces these actuators can achieve. To overcome these limitations, we have developed a new pulsed valve based on a high-force piezoelectric stack actuator. We show here that operation with pulse durations as low as 20 μs and repetition rates up to 100 Hz can be easily achieved by operating the valve in conjunction with a commercialmore » fast high-voltage switch. We outline our design and demonstrate its performance with molecular beam characterization via velocity map ion imaging.« less

[Analysis on Mechanism of Rainout Carried by Wet Stack of Thermal Power Plant].

PubMed

Ouyang, Li-hua; Zhuang, Ye; Liu, Ke-wei; Chen, Zhen-yu; Gu, Peng

2015-06-01

Rainout from wet-stack took placed in many thermal power plants with WFGD system. Research on causes of the rainout is important to solve the problem. The objective of this research is to analyze the mechanism of rainout. Field study was performed to collect experimental data in one thermal power plant, including the amount of desulfurization slurry carried by wet flue gas, liquor condensate from wet duct, and droplets from the wet stack. Source apportionment analysis was carried out based on physical and chemical data of liquid sample and solid sample. The result showed that mist eliminator operated well, which met the performance guarantee value. But the total amount of desulfurization slurry in flue gas and the sulfate concentration in liquid condensate discharge from the wet duct/stack increased. The liquid condensate accumulated in the wet duct/stack led to liquid re-entrainment. In conclusion, the rainout in this power plant was caused by the short of wet ductwork or liquid discharge system, the droplets caused by re-entrainment carried by the saturated gas released from the stack. The main undissolved components of the rainout were composite carbonate and aluminosilicate. Although ash concentration in this WFGD met the regulation criteria, source apportionment analysis showed that fly ash contributed to rainout was accounted for 60%. This percentage value was same as the data of solid particles in the condensate. It is important to optimize the wet ductwork, wet stack liner, liquid collectors and drainage. Avoiding the accumulation from saturated vapor thermal condensation is an effective way to solve the wet stack rainout.

40 CFR 60.747 - Reporting and recordkeeping requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... monitoring only the carbon adsorption system outlet concentration levels of organic compounds, the periods.... (i) For carbon adsorption systems with a common exhaust stack for all the individual adsorber vessels... recent performance test that demonstrated compliance. (ii) For carbon adsorption systems with individual...

40 CFR 60.747 - Reporting and recordkeeping requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... monitoring only the carbon adsorption system outlet concentration levels of organic compounds, the periods.... (i) For carbon adsorption systems with a common exhaust stack for all the individual adsorber vessels... recent performance test that demonstrated compliance. (ii) For carbon adsorption systems with individual...

40 CFR 60.747 - Reporting and recordkeeping requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... monitoring only the carbon adsorption system outlet concentration levels of organic compounds, the periods.... (i) For carbon adsorption systems with a common exhaust stack for all the individual adsorber vessels... recent performance test that demonstrated compliance. (ii) For carbon adsorption systems with individual...

40 CFR 60.747 - Reporting and recordkeeping requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... monitoring only the carbon adsorption system outlet concentration levels of organic compounds, the periods.... (i) For carbon adsorption systems with a common exhaust stack for all the individual adsorber vessels... recent performance test that demonstrated compliance. (ii) For carbon adsorption systems with individual...

Reconfigurable Wideband Circularly Polarized Stacked Square Patch Antenna for Cognitive Radios

NASA Technical Reports Server (NTRS)

Barbosa Kortright, Miguel A.; Waldstein, Seth W.; Simons, Rainee N.

2017-01-01

An almost square patch, a square patch and a stacked square patch with corner truncation for circular polarization (CP) are researched and developed at X-band for cognitive radios. Experimental results indicate, first, that the impedance bandwidth of a CP almost square patch fed from the edge by a 50 ohm line is 1.70 percent and second, that of a CP square patch fed from the ground plane side by a surface launch connector is 1.87 percent. Third, the impedance bandwidth of a CP stacked square patch fed by a surface launch connector is 2.22 percent. The measured center frequency for the CP square patch fed by a surface launch connector without and with an identical stacked patch is 8.45 and 8.1017 GHz, respectively. By stacking a patch, separated by a fixed air gap of 0.254 mm, the center frequency is observed to shift by as much as 348.3 MHz. The shift in the center frequency can be exploited to reconfigure the operating frequency by mechanically increasing the air gap. The results indicate that a tuning bandwidth of about 100 MHz can be achieved when the distance of separation between the driven patch and the stacked patch is increased from its initial setting of 0.254 to 1.016 mm.

Multilayer Piezoelectric Stack Actuator Characterization

NASA Technical Reports Server (NTRS)

Sherrit, Stewart; Jones, Christopher M.; Aldrich, Jack B.; Blodget, Chad; Bao, Xioaqi; Badescu, Mircea; Bar-Cohen, Yoseph

2008-01-01

Future NASA missions are increasingly seeking to use actuators for precision positioning to accuracies of the order of fractions of a nanometer. For this purpose, multilayer piezoelectric stacks are being considered as actuators for driving these precision mechanisms. In this study, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and extreme temperatures and voltages. AC signal testing included impedance, capacitance and dielectric loss factor of each actuator as a function of the small-signal driving sinusoidal frequency, and the ambient temperature. DC signal testing includes leakage current and displacement as a function of the applied DC voltage. The applied DC voltage was increased to over eight times the manufacturers' specifications to investigate the correlation between leakage current and breakdown voltage. Resonance characterization as a function of temperature was done over a temperature range of -180C to +200C which generally exceeded the manufacturers' specifications. In order to study the lifetime performance of these stacks, five actuators from one manufacturer were driven by a 60volt, 2 kHz sine-wave for ten billion cycles. The tests were performed using a Lab-View controlled automated data acquisition system that monitored the waveform of the stack electrical current and voltage. The measurements included the displacement, impedance, capacitance and leakage current and the analysis of the experimental results will be presented.

Seismic Reservoir Characterization for Assessment of CO2 EOR at the Mississippian Reservoir in South-Central Kansas

NASA Astrophysics Data System (ADS)

Tsoflias, G. P.; Graham, B.; Haga, L.; Watney, L.

2017-12-01

The Mississippian in Kansas and Oklahoma is a highly heterogeneous, fractured, oil producing reservoir with thickness typically below seismic resolution. At Wellington field in south-central Kansas CO2 was injected in the Mississippian reservoir for enhanced oil recovery. This study examines the utility of active source surface seismic for characterization of Mississippian reservoir properties and monitoring CO2. Analysis of post-stack 3D seismic data showed the expected response of a gradational transition (ramp velocity) where thicker reservoir units corresponded with lower reflection amplitudes, lower frequency and a 90o phase change. Reflection amplitude could be correlated to reservoir thickness. Pre-stack gather analysis showed that porosity zones of the Mississippian reservoir exhibit characteristic AVO response. Simultaneous AVO inversion estimated P- and S-Impedances, which along with formation porosity logs and post-stack seismic data attributes were incorporated in multi-attribute linear-regression analysis and predicted reservoir porosity with an overall correlation of 0.90 to well data. The 3D survey gather azimuthal anisotropy analysis (AVAZ) provided information on the fault and fracture network and showed good agreement to the regional stress field and well data. Mississippian reservoir porosity and fracture predictions agreed well with the observed mobility of the CO2 in monitoring wells. Fluid substitution modeling predicted acoustic impedance reduction in the Mississippian carbonate reservoir introduced by the presence of CO2. Future work includes the assessment of time-lapse seismic, acquired after the injection of CO2. This work demonstrates that advanced seismic interpretation methods can be used successfully for characterization of the Mississippian reservoir and monitoring of CO2.

Acquisition of multiple image stacks with a confocal laser scanning microscope

NASA Astrophysics Data System (ADS)

Zuschratter, Werner; Steffen, Thomas; Braun, Katharina; Herzog, Andreas; Michaelis, Bernd; Scheich, Henning

1998-06-01

Image acquisition at high magnification is inevitably correlated with a limited view over the entire tissue section. To overcome this limitation we designed software for multiple image-stack acquisition (3D-MISA) in confocal laser scanning microscopy (CLSM). The system consists of a 4 channel Leica CLSM equipped with a high resolution z- scanning stage mounted on a xy-monitorized stage. The 3D- MISA software is implemented into the microscope scanning software and uses the microscope settings for the movements of the xy-stage. It allows storage and recall of 70 xyz- positions and the automatic 3D-scanning of image arrays between selected xyz-coordinates. The number of images within one array is limited only by the amount of disk space or memory available. Although for most applications the accuracy of the xy-scanning stage is sufficient for a precise alignment of tiled views, the software provides the possibility of an adjustable overlap between two image stacks by shifting the moving steps of the xy-scanning stage. After scanning a tiled image gallery of the extended focus-images of each channel will be displayed on a graphic monitor. In addition, a tiled image gallery of individual focal planes can be created. In summary, the 3D-MISA allows 3D-image acquisition of coherent regions in combination with high resolution of single images.

The Characterisation of a PEM Fuel-Cell System with a Focus on UAS Applications

DTIC Science & Technology

2014-01-01

consumption at rated output Approximately 580 ml/min (at normal conditions) Maximum permissible cell temperature Operation: 50 °C; starting: 45 °C...serves to control the temperature of the stack as well as to provide oxygen for the reaction. Fur- thermore, the theoretically computed airflow rate is...The stack temperature has a significant effect on the performance of a fuel cell. Therefore, an understanding of how a fuel cell functions across a

Physical and chemical characterization of residual oil-fired power plant emissions

EPA Science Inventory

Although the toxicity of oil combustion emissions is a significant public health concern, few studies characterize the emissions from plant-scale utility boilers firing residual oil. This study remedies that deficiency by sampling and monitoring stack emissions from a 432 Giga Jo...

40 CFR 63.1352 - Additional test methods.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing Industry Monitoring and... rates of emission of HCl from kilns and associated bypass stacks at portland cement manufacturing... specific organic HAP from raw material dryers, kilns and in-line kiln/raw mills at Portland cement...

40 CFR 63.1352 - Additional test methods.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing Industry Monitoring and... rates of emission of HCl from kilns and associated bypass stacks at portland cement manufacturing... specific organic HAP from raw material dryers, kilns and in-line kiln/raw mills at Portland cement...

40 CFR 52.380 - Rules and regulations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the following elements of the revisions: (1)-(2) [Reserved] (3) The program to review new and modified... (5) Stack height regulations (6) Interstate pollution requirements (7) Monitoring requirements (8) Conflict of interest provisions. (9) Use of 1 percent sulfur content fuel by the following residual oil...

40 CFR 52.380 - Rules and regulations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the following elements of the revisions: (1)-(2) [Reserved] (3) The program to review new and modified... (5) Stack height regulations (6) Interstate pollution requirements (7) Monitoring requirements (8) Conflict of interest provisions. (9) Use of 1 percent sulfur content fuel by the following residual oil...

40 CFR 52.380 - Rules and regulations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the following elements of the revisions: (1)-(2) [Reserved] (3) The program to review new and modified... (5) Stack height regulations (6) Interstate pollution requirements (7) Monitoring requirements (8) Conflict of interest provisions. (9) Use of 1 percent sulfur content fuel by the following residual oil...

40 CFR 52.380 - Rules and regulations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the following elements of the revisions: (1)-(2) [Reserved] (3) The program to review new and modified... (5) Stack height regulations (6) Interstate pollution requirements (7) Monitoring requirements (8) Conflict of interest provisions. (9) Use of 1 percent sulfur content fuel by the following residual oil...

NASA Ames Research Center 60 MW Power Supply Modernization

NASA Technical Reports Server (NTRS)

Choy, Yuen Ching; Ilinets, Boris V.; Miller, Ted; Nagel, Kirsten (Technical Monitor)

2001-01-01

The NASA Ames Research Center 60 MW DC Power Supply was built in 1974 to provide controlled DC power for the Thermophysics Facility Arc Jet Laboratory. The Power Supply has gradually losing reliability due to outdated technology and component life limitation. NASA has decided to upgrade the existing rectifier modules with contemporary high-power electronics and control equipment. NASA plans to complete this project in 2001. This project includes a complete replacement of obsolete thyristor stacks in all six rectifier modules and rectifier bridge control system. High power water-cooled thyristors and freewheeling diodes will be used. The rating of each of the six modules will be 4000 A at 5500 V. The control firing angle signal will be sent from the Facility Control System to six modules via fiberoptic cable. The Power Supply control and monitoring system will include a Master PLC in the Facility building and a Slave PLC in each rectifier module. This system will also monitor each thyristor level in each stack and the auxiliary equipment.

High temperature semiconductor diode laser pumps for high energy laser applications

NASA Astrophysics Data System (ADS)

Campbell, Jenna; Semenic, Tadej; Guinn, Keith; Leisher, Paul O.; Bhunia, Avijit; Mashanovitch, Milan; Renner, Daniel

2018-02-01

Existing thermal management technologies for diode laser pumps place a significant load on the size, weight and power consumption of High Power Solid State and Fiber Laser systems, thus making current laser systems very large, heavy, and inefficient in many important practical applications. To mitigate this thermal management burden, it is desirable for diode pumps to operate efficiently at high heat sink temperatures. In this work, we have developed a scalable cooling architecture, based on jet-impingement technology with industrial coolant, for efficient cooling of diode laser bars. We have demonstrated 60% electrical-to-optical efficiency from a 9xx nm two-bar laser stack operating with propylene-glycolwater coolant, at 50 °C coolant temperature. To our knowledge, this is the highest efficiency achieved from a diode stack using 50 °C industrial fluid coolant. The output power is greater than 100 W per bar. Stacks with additional laser bars are currently in development, as this cooler architecture is scalable to a 1 kW system. This work will enable compact and robust fiber-coupled diode pump modules for high energy laser applications.

Artificial dielectric stepped-refractive-index lens for the terahertz region.

PubMed

Hernandez-Serrano, A I; Mendis, Rajind; Reichel, Kimberly S; Zhang, Wei; Castro-Camus, E; Mittleman, Daniel M

2018-02-05

In this paper we theoretically and experimentally demonstrate a stepped-refractive-index convergent lens made of a parallel stack of metallic plates for terahertz frequencies based on artificial dielectrics. The lens consist of a non-uniformly spaced stack of metallic plates, forming a mirror-symmetric array of parallel-plate waveguides (PPWGs). The operation of the device is based on the TE 1 mode of the PPWG. The effective refractive index of the TE 1 mode is a function of the frequency of operation and the spacing between the plates of the PPWG. By varying the spacing between the plates, we can modify the local refractive index of the structure in every individual PPWG that constitutes the lens producing a stepped refractive index profile across the multi stack structure. The theoretical and experimental results show that this structure is capable of focusing a 1 cm diameter beam to a line focus of less than 4 mm for the design frequency of 0.18 THz. This structure shows that this artificial-dielectric concept is an important technology for the fabrication of next generation terahertz devices.

Ti-Doped GaOx Resistive Switching Memory with Self-Rectifying Behavior by Using NbOx/Pt Bilayers.

PubMed

Park, Ju Hyun; Jeon, Dong Su; Kim, Tae Geun

2017-12-13

Crossbar arrays (CBAs) with resistive random access memory (ReRAM) constitute an established architecture for high-density memory. However, sneak paths via unselected cells increase the total power consumption of these devices and limit the array size. To eliminate such sneak-path problems, we propose a Ti/GaO x /NbO x /Pt structure with a self-rectifying resistive-switching (RS) behavior. In this structure, to reduce the operating voltage, we used a Ti/GaO x stack to increase the number of trap sites in the RS GaO x layer through interfacial reactions between the Ti and GaO x layers. This increase enables easier carrier transport with reduced electric fields. We then adopted a NbO x /Pt stack to add rectifying behavior to the RS GaO x layer. This behavior is a result of the large Schottky barrier height between the NbO x and Pt layers. Finally, both the Ti/GaO x and NbO x /Pt stacks were combined to realize a self-rectifying ReRAM device, which exhibited excellent performance. Characteristics of the device include a low operating voltage range (-2.8 to 2.5 V), high on/off ratios (∼20), high selectivity (∼10 4 ), high operating speeds (200-500 ns), a very low forming voltage (∼3 V), stable operation, and excellent uniformity for high-density CBA-based ReRAM applications.

AGC-4 Experiment Irradiation Monitoring Data Qualification Interim Report

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

Hull, Laurence Charles

2016-08-01

The Graphite Technology Development Program is running a series of six experiments to quantify the effects of irradiation on nuclear grade graphite. The fourth experiment, Advanced Graphite Creep 4 (AGC 4), began with Advanced Test Reactor (ATR) cycle 157D on May 30, 2015, and has been irradiated for two cycles. The capsule was removed from the reactor after ATR cycle 158A, which ended on January 2, 2016, due to interference with another experiment. Irradiation will resume when the interfering experiment is removed from the reactor. This report documents qualification of AGC 4 experiment irradiation monitoring data for use by themore » Advanced Reactor Technologies (ART) Technology Development Office (TDO) Program for research and development activities required to design and license the first HTR nuclear plant. Qualified data meet the requirements for use as described in the experiment planning and quality assurance documents. Failed data do not meet the requirements and provide no useable information. Trend data may not meet all requirements, but still provide some useable information. Use of Trend data requires assessment of how any deficiencies affect a particular use of the data. All thermocouples (TCs) have functioned throughout the AGC-4 experiment. All temperature data are Qualified for use by the ART TDO Program. Argon, helium, and total gas flow data were within expected ranges and are Qualified for use by the ART TDO Program. Discharge gas line moisture values were consistently low during cycle 157D. At the start of cycle 158A, gas moisture briefly spiked to over 600 ppmv and then declined throughout the cycle. Moisture values are within the measurement range of the instrument and are Qualified for use by the ART TDO Program. Graphite creep specimens were subjected to one of three loads, 393, 491, or 589 lbf. For a brief period during cycle 157D between 12:19 on June 2, 2015 and 08:23 on June 11, 2015 the load cells were wired incorrectly resulting in missing stack load data. Missing stack loads were estimated from measured ram pressures using regression equations developed from the existing data from cycle 157D. Estimated stack loads during this period are considered to be an accurate representation of actual load applied to the stacks. These loads deviate slightly from the planned loads. This deviation does not prevent the data from being Qualified for use, but must be taken into account when analyzing the effect of load on creep. Stack displacement increased consistently throughout the first two cycles with total displacement ranging from 0.4 to 0.8 in. During ATR outages, a set of pneumatic rams raised the stacks of graphite creep specimens to ensure the specimens were not stuck within the test train. This stack raising was performed twice. All stacks were raised successfully each time. The load and displacement data are Qualified for use by the ART TDO Program.« less

KSC-2013-3726

NASA Image and Video Library

2013-10-22

CAPE CANAVERAL, Fla. – At NASA’s Kennedy Space Center in Florida, technicians monitor the progress as the Orion ground test vehicle, or GTA, was lifted high in the air by crane in the transfer aisle of the Vehicle Assembly Building and is being lowered toward a mockup of the service module in high bay 4. The ground test vehicle is being used for path finding operations, including simulated manufacturing, assembly and stacking procedures. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted test flight of Orion is scheduled to launch in 2014 atop a Delta IV rocket and in 2017 on NASA’s Space Launch System rocket. For more information, visit www.nasa.gov/orion. Photo credit: Dimitri Gerondidakis

Lifetime improvement mechanism in organic light-emitting diodes with mixed materials at a heterojunction interface

NASA Astrophysics Data System (ADS)

Minagawa, Masahiro; Takahashi, Noriko

2016-02-01

To investigate the lifetime improvement mechanism caused by mixing at the heterojunction interface, organic light-emitting diodes (OLEDs) with stacked and mixed 4,4‧-bis[N-(1-naphthyl)-N-phenyl-amino]-biphenyl (α-NPD)/tris(8-hydroxyquinoline)aluminum (Alq3) interfaces were fabricated, and changes in their displacement current due to continuous operation were measured. A decrease in accumulated holes at the α-NPD/Alq3 interface was observed in the stacked configuration devices over longer operations. These results indicate that the injected hole density was reduced during continuous operation, implying that the carrier balance became uneven in the emission region. However, few accumulated holes and changes in the displacement current due to continuous operation were observed in the devices having the mixed layer. Therefore, it was deduced that the number of holes concentrated between the α-NPD and Alq3 layers was decreased by mixing at the heterojunction interface, and that the change in the number of holes was smaller during continuous operation, resulting in less degradation.

Superresolution near-field imaging with surface waves

NASA Astrophysics Data System (ADS)

Fu, Lei; Liu, Zhaolun; Schuster, Gerard

2018-02-01

We present the theory for near-field superresolution imaging with surface waves and time reverse mirrors (TRMs). Theoretical formulae and numerical results show that applying the TRM operation to surface waves in an elastic half-space can achieve superresolution imaging of subwavelength scatterers if they are located less than about 1/2 of the shear wavelength from the source line. We also show that the TRM operation for a single frequency is equivalent to natural migration, which uses the recorded data to approximate the Green's functions for migration, and only costs O(N4) algebraic operations for post-stack migration compared to O(N6) operations for natural pre-stack migration. Here, we assume the sources and receivers are on an N × N grid and there are N2 trial image points on the free surface. Our theoretical predictions of superresolution are validated with tests on synthetic data. The field-data tests suggest that hidden faults at the near surface can be detected with subwavelength imaging of surface waves by using the TRM operation if they are no deeper than about 1/2 the dominant shear wavelength.

PBF (PER620) north facade. Camera facing south. Small metal shed ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF (PER-620) north facade. Camera facing south. Small metal shed at right is Stack Gas Monitor Building, PER-629. Date: March 2004. INEEL negative no. HD-41-2-4 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Simplified and low cost optical remote sensing technology for fenceline monitoring of fugitive releases

EPA Science Inventory

Reducing fugitive emissions of hazardous air pollutants from industrial facilities is an ongoing priority for the U.S. Environmental Protection Agency (EPA). Unlike stack emissions, fugitive releases are difficult to detect due to their spatial extent and inherent temporal variab...

Data recording and trend display during anaesthesia using 'MacLab'.

PubMed

Kennedy, R R

1991-08-01

A single screen display of variables monitored during anaesthesia may be ergonomically superior to the 'stack' of monitors seen in many anaesthetising locations. A system based on a MacLab (Analogue Digital Instruments) analogue-to-digital convertor used in conjunction with a Macintosh computer was evaluated. The system was configured to provide trend displays of up to eight variables on a single screen. It was found to be a useful adjunct to monitoring during anaesthesia. Advantages of this system are low cost, flexibility, and the quality of the software and support provided. Limitations of this and other similar systems are discussed.

A High Volume Stack Sampler

NASA Technical Reports Server (NTRS)

Boubel, Richard W.

1971-01-01

The stack sampler described in this paper has been developed to overcome the difficulties of particulate sampling with presently available equipment. Its use on emissions from hog fuel fired boilers, back-fired incinerators, wigwam burners, asphalt plants, and seed cleaning cyclones is reported. The results indicate that the sampler is rapid and reliable in its use. It is relatively simple and inexpensive to operate. For most sources it should be considered over the more complicated and expensive sampling trains being used and specified.

LOFT. Containment building (TAN650) with fourrail tracks in place. Stack ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

LOFT. Containment building (TAN-650) with four-rail tracks in place. Stack has been erected. Curved shroud over doorway and to the right is weather protection for railroad door seen in HAER photo ID-33-E-367. Motor-operated door rolls on wheels to open and close. Service portions of containment building can be seen at rear of dome on left and right. Camera facing north. Date: 1973. INEEL negative no. 73-1600 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Material characteristics and equivalent circuit models of stacked graphene oxide for capacitive humidity sensors

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

Han, Kook In; Lee, In Gyu; Hwang, Wan Sik, E-mail: mhshin@kau.ac.kr, E-mail: whwang@kau.ac.kr

The oxidation properties of graphene oxide (GO) are systematically correlated with their chemical sensing properties. Based on an impedance analysis, the equivalent circuit models of the capacitive sensors are established, and it is demonstrated that capacitive operations are related to the degree of oxidation. This is also confirmed by X-ray diffraction and Raman analysis. Finally, highly sensitive stacked GO sensors are shown to detect humidity in capacitive mode, which can be useful in various applications requiring low power consumption.

Parsing recursive sentences with a connectionist model including a neural stack and synaptic gating.

PubMed

Fedor, Anna; Ittzés, Péter; Szathmáry, Eörs

2011-02-21

It is supposed that humans are genetically predisposed to be able to recognize sequences of context-free grammars with centre-embedded recursion while other primates are restricted to the recognition of finite state grammars with tail-recursion. Our aim was to construct a minimalist neural network that is able to parse artificial sentences of both grammars in an efficient way without using the biologically unrealistic backpropagation algorithm. The core of this network is a neural stack-like memory where the push and pop operations are regulated by synaptic gating on the connections between the layers of the stack. The network correctly categorizes novel sentences of both grammars after training. We suggest that the introduction of the neural stack memory will turn out to be substantial for any biological 'hierarchical processor' and the minimalist design of the model suggests a quest for similar, realistic neural architectures. Copyright © 2010 Elsevier Ltd. All rights reserved.

Order-disorder twinning model and stacking faults in alpha-NTO.

PubMed

Schwarzenbach, Dieter; Kirschbaum, Kristin; Pinkerton, A Alan

2006-10-01

Crystals of the recently published [Bolotina, Kirschbaum & Pinkerton (2005). Acta Cryst. B61, 577-584] triclinic (P\\overline1) structure of 5-nitro-2,4-dihydro-1,2,4-triazol-3-one (alpha-NTO) occur as fourfold twins. There are Z' = 4 independent molecules per asymmetric unit. We show that the structure contains layers with 2-periodic layer-group symmetry p2(1)/b 1 (1). This symmetry is lost through the stacking of the layers, which is a possible explanation for Z' = 4. A layer can assume four different but equivalent positions with respect to its nearest neighbor. Twinning arises through stacking faults and is an instructive example of the application of order-disorder theory using local symmetry operations. The near-neighbor relations between molecules remain unchanged through all twin boundaries. The four structures with maximum degree of order, one of which is the observed one, and the family reflections common to all domains are identified. Rods of weak diffuse scattering confirm the stacking model.

Mercury Dispersion Modeling And Purge Ventilation Stack Height Determination For Tank 40H

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

Rivera-Giboyeaux, A.

2017-05-19

The SRNL Atmospheric Technologies Group performed an analysis for mercury emissions from H-Tank Farm - Tank 40 ventilation system exhaust in order to assess whether the Short Term Exposure Limit (STEL), or Threshold Limit Value (TLV) levels for mercury will be exceeded during bulk sludge slurry mixing and sludge removal operations. The American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) was used as the main dispersion modelling tool for this analysis. The results indicated that a 45-foot stack is sufficient to raise the plume centerline from the Tank 40 release to prevent mercury exposure problems for any of the stackmore » discharge scenarios provided. However, a 42-foot stack at Tank 40 is sufficient to prevent mercury exposure concerns in all emission scenarios except the 50 mg/m 3 release. At a 42-foot stack height, values exceeding the exposure standards are only measured on receptors located above 34 feet.« less

Study of Thermomechanical Properties of The Epoxy-Impregnated Cable Composite for a 15 T Nb3Sn Dipole Demonstrator

NASA Astrophysics Data System (ADS)

Li, Pei; Krave, Steve; Zlobin, Alexander

2017-12-01

The knowledge of the thermomechanical properties of the composite of cable/insulation/epoxy impregnation are important for the design, fabrication and operation of superconducting accelerator magnets. As a part of the 15 T dipole magnet development at Fermi National Accelerator Laboratory (FNAL), we studied the thermomechanical properties of cable stack that represents the cable composites in the 15 T dipole. The measurements include thermal contraction and strain-stress characterization under compressive load along the principal directions. The cable stack samples show hysteresis behaviour in loading-unloading cycles, which is found to be most dramatic along the azimuthal direction. Also, the choice of insulation material/procedure is found to strongly impact the bonding between cables and epoxy/cable layers. The cable stacks measured in this study use E-glass tape wrapping insulation and show weaker bonding to cables than similar cable stacks using S-2 glass sleeves insulation previously studied.

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

Rao, Nageswara S.; Ramirez Aviles, Camila A.

We consider the problem of inferring the operational status of a reactor facility using measurements from a radiation sensor network deployed around the facility’s ventilation off-gas stack. The intensity of stack emissions decays with distance, and the sensor counts or measurements are inherently random with parameters determined by the intensity at the sensor’s location. We utilize the measurements to estimate the intensity at the stack, and use it in a one-sided Sequential Probability Ratio Test (SPRT) to infer on/off status of the reactor. We demonstrate the superior performance of this method over conventional majority fusers and individual sensors using (i)more » test measurements from a network of 21 NaI detectors, and (ii) effluence measurements collected at the stack of a reactor facility. We also analytically establish the superior detection performance of the network over individual sensors with fixed and adaptive thresholds by utilizing the Poisson distribution of the counts. We quantify the performance improvements of the network detection over individual sensors using the packing number of the intensity space.« less

Compact piezoelectric tripod manipulator based on a reverse bridge-type amplification mechanism

NASA Astrophysics Data System (ADS)

Na, Tae-Won; Choi, Jun-Ho; Jung, Jin-Young; Kim, Hyeong-Geon; Han, Jae-Hung; Park, Kwang-Chun; Oh, Il-Kwon

2016-09-01

We report a hierarchical piezoelectric tripod manipulator based on a reverse bridge-type displacement amplifier. The reverse bridge-type amplification mechanism is pre-strained by each piezo-stack actuator up to 60 μm and is cross-stacked in a series arrangement to make a compact and high-stroke manipulator having load-bearing characteristics. The designed manipulator with three degrees of freedom is compact with a height of 56.0 mm, a diameter of 48.6 mm and total weight of 115 g. It achieves a translational stroke of up to 880 μm in heaving motion and a tilting angle of up to 2.0° in rotational motion within the operating voltage and power range of the piezoelectric stack actuator. A key feature of the present design is built-in and pre-strained displacement amplification mechanisms integrated with piezoelectric stacked actuators, resulting in a compact tripod manipulator having exceptionally high stroke and load-bearing capacity.

Feasibility of Active Monitoring for Plate Coupling Using ACROSS

NASA Astrophysics Data System (ADS)

Yamaoka, K.; Watanabe, T.; Ikuta, R.

2004-12-01

Detectability of temporal changes in reflected wave from the boundary of subducting plates in Tokai district with active sources are studied. Based on rock experiments the change in the intensity of reflection wave can be caused by change in coupling between subducting and overriding plates. ACROSS (Accurately-Controlled Rountine-Operated Signal System) consists of sinusoidal vibration sources and receivers is proved to provide a data of excellent signal resolution. The following technical issues should be overcome to monitor the returned signal from boundaries of subducting plates. (1) Long term operation of the source. (2) Detection of temporal change. (3) Accurate estimation of source functions and their temporal change. First two issues have already overcome. We have already succeeded a long-term operation experiment with the ACROSS system in Awaji, Japan. The operation was carried out for 15 months with only minor troubles. Continuous signal during the experiment are successfully obtained. In the experiment we developed a technique to monitor the temporal change of travel time with a resolution of several tens of microseconds. The third issue is one of the most difficult problem for practical monitoring using artificial sources. In the 15-month experiment we correct the source function using the record of seismometers that were deployed around the source We also estimate the efficiency of the reflected wave detection using ACROSS system. We use a data of seismic exploration experiment by blasts that carried out above subducting plate in Tokai district. Clear reflection from the surface of the Philippine Sea plate is observed in the waveform. Assuming that the ACROSS source is installed at the same place of the blast source, the detectability of temporal variation of reflection wave can be estimated. As we have measured the variation of signal amplitude that depends on the distance from an ACROSS source, ground noise at seismic stations (receivers) provide us the signal-to-noise ratio for the signal from ACROSS. The resolution can be estimated only by the signal-to-noise ratio. We surveyed the noise level at the place where reflection from the boundary of subducting Philippine Sea Plate can be detected. The results show that the resolution will be better than 1% in amplitude and 0.1milisecond in travel time for the stacking of one week using three-unit source and ten-elements receiver arrays.

Use of Sentinel-1 SAR data to monitor Mosul dam vulnerability

NASA Astrophysics Data System (ADS)

Riccardi, Paolo; Tessari, Giulia; Lecci, Daniele; Floris, Mario; Pasquali, Paolo

2017-04-01

The structural monitoring of dams is an important practice to guarantee their safety. Moreover, the water reservoir and the efficient operation and safety of surrounding areas need to be monitored. Considering the importance of large dams as multipurpose infrastructure for flood control, energy production, water supply and irrigation, ensuring their longevity is a key aspect on their management. Therefore, it is of great importance to detect dam deterioration potentially resulting in its shutdown or failure, preventing life and economic losses. Traditional dam monitoring requires the identification of soil movements, tilt, displacements, structural stress and strain behaviour. Since the '90, innovative remote sensing techniques based on satellite Synthetic Aperture Radar (SAR) data were developed to detect and monitor surface displacements. The main advantages of SAR data are the non-invasiveness of their acquisition, the possibility to cover large areas in a short time and the advancement. Moreover, the availability of SAR satellite acquisitions from the 1990s enables to reconstruct the historical evolution of dam behaviour. Furthermore, the use of SAR Interferometry (InSAR) techniques, Differential InSAR (DInSAR) and Advanced stacking techniques (A-DInSAR), produce accurate velocity maps and displacement time-series. The importance of these techniques emerges when environmental or logistic conditions do not allow to monitor dams applying the traditional geodetic techniques. An iconic case demonstrating the relevance of remote sensing observations is the Mosul Dam, the largest Iraqi dam, where monitoring and maintaining are impeded for political controversy, thus the risk for the population is very high. It is considered one of the most dangerous dams in the world because of the erosion of the gypsum rock at the basement and the difficult interventions due to security issues. It consists of 113 m tall and 3.4 km long earth-fill embankment-type, with a clay core. It was completed in 1984 and started generating power on 1986. Since then, frequent consolidation works have been carried out pumping cement mixtures into the soil foundation to keep it stable and prevent it from sinking and then breaking apart. To overcome the impossibility of directly monitoring the structure, analysis of recent deformation affecting the Mosul dam is achieved considering C-band Sentinel-1 SAR data, acquired from the end of 2014 to the present. These 20-m ground resolution data can provide a millimetric precision on displacements. Furthermore, ESA archive available SAR data (ERS and Envisat) are considered to reconstruct the temporal evolution of the deformations. In this work, different stacks of data are processed applying SBAS and PS A-DInSAR techniques; deformation fields obtained from SAR data are evaluated to assess the temporal evolution of the strains affecting the structure. Obtained results represent the preliminary stage of a multidisciplinary project, finalised to assess possible damages affecting a dam through remote sensing and civil engineering surveys.

Nonlinear empirical model of gas humidity-related voltage dynamics of a polymer-electrolyte-membrane fuel cell stack

NASA Astrophysics Data System (ADS)

Meiler, M.; Andre, D.; Schmid, O.; Hofer, E. P.

Intelligent energy management is a cost-effective key path to realize efficient automotive drive trains [R. O'Hayre, S.W. Cha, W. Colella, F.B. Prinz. Fuel Cell Fundamentals, John Wiley & Sons, Hoboken, 2006]. To develop operating strategy in fuel cell drive trains, precise and computational efficient models of all system components, especially the fuel cell stack, are needed. Should these models further be used in diagnostic or control applications, then some major requirements must be fulfilled. First, the model must predict the mean fuel cell voltage very precisely in all possible operating conditions, even during transients. The model output should be as smooth as possible to support best efficient optimization strategies of the complete system. At least, the model must be computational efficient. For most applications, a difference between real fuel cell voltage and model output of less than 10 mV and 1000 calculations per second will be sufficient. In general, empirical models based on system identification offer a better accuracy and consume less calculation resources than detailed models derived from theoretical considerations [J. Larminie, A. Dicks. Fuel Cell Systems Explained, John Wiley & Sons, West Sussex, 2003]. In this contribution, the dynamic behaviour of the mean cell voltage of a polymer-electrolyte-membrane fuel cell (PEMFC) stack due to variations in humidity of cell's reactant gases is investigated. The validity of the overall model structure, a so-called general Hammerstein model (or Uryson model), was introduced recently in [M. Meiler, O. Schmid, M. Schudy, E.P. Hofer. Dynamic fuel cell stack model for real-time simulation based on system identification, J. Power Sources 176 (2007) 523-528]. Fuel cell mean voltage is calculated as the sum of a stationary and a dynamic voltage component. The stationary component of cell voltage is represented by a lookup-table and the dynamic voltage by a parallel placed, nonlinear transfer function. A suitable experimental setup to apply fast variations of gas humidity is introduced and is used to investigate a 10 cell PEMFC stack under various operation conditions. Using methods like stepwise multiple-regression a good mathematical description with reduced free parameters is achieved.

The computing and data infrastructure to interconnect EEE stations

NASA Astrophysics Data System (ADS)

Noferini, F.; EEE Collaboration

2016-07-01

The Extreme Energy Event (EEE) experiment is devoted to the search of high energy cosmic rays through a network of telescopes installed in about 50 high schools distributed throughout the Italian territory. This project requires a peculiar data management infrastructure to collect data registered in stations very far from each other and to allow a coordinated analysis. Such an infrastructure is realized at INFN-CNAF, which operates a Cloud facility based on the OpenStack opensource Cloud framework and provides Infrastructure as a Service (IaaS) for its users. In 2014 EEE started to use it for collecting, monitoring and reconstructing the data acquired in all the EEE stations. For the synchronization between the stations and the INFN-CNAF infrastructure we used BitTorrent Sync, a free peer-to-peer software designed to optimize data syncronization between distributed nodes. All data folders are syncronized with the central repository in real time to allow an immediate reconstruction of the data and their publication in a monitoring webpage. We present the architecture and the functionalities of this data management system that provides a flexible environment for the specific needs of the EEE project.

Monitoring industrial wastewater by online GC-MS with direct aqueous injection.

PubMed

Wortberg, M; Ziemer, W; Kugel, M; Müller, H; Neu, H-J

2006-03-01

An online GC-MS-system for automated monitoring of crude wastewater at a complex chemical production site is presented. The modular system is, in principal, based on commercial equipment, but utilizes a special, two-stage injector, which consists of a splitless vaporization chamber on top of a PTV injector filled with Tenax. This set-up enables direct injection of wastewater. Almost 140 volatile and semi-volatile compounds are calibrated down to 1 mg L(-1), which is sufficient for analysis of the influent of the wastewater-treatment plant. Two instruments analyze alternately, every 20 min, and the instrument cycle time is 40 min. The quantitative results are transferred to a database which is connected to a process-control system. Depending on the nature and concentration of a compound, an alarm can be generated and the wastewater stream can be diverted into an "off spec tank" if necessary. The GC-MS-system operates quasi-continuously with a system availability >98%. Data quality is automatically controlled in each run and by daily analysis of a quality-control sample. The development of a novel stacked PTV-PTV injector design to expand the range of analytes to selected basic compounds is described.

Real-time monitoring of human blood clotting using a lateral excited film bulk acoustic resonator

NASA Astrophysics Data System (ADS)

Chen, Da; Wang, Jingjng; Wang, Peng; Guo, Qiuquan; Zhang, Zhen; Ma, Jilong

2017-04-01

Frequent assay of hemostatic status is an essential issue for the millions of patients using anticoagulant drugs. In this paper, we presented a micro-fabricated film bulk acoustic sensor for the real-time monitoring of blood clotting and the measurement of hemostatic parameters. The device was made of an Au/ZnO/Si3N4 film stack and excited by a lateral electric field. It operated under a shear mode resonance with the frequency of 1.42 GHz and had a quality factor of 342 in human blood. During the clotting process of blood, the resonant frequency decreased along with the change of blood viscosity and showed an apparent step-ladder curve, revealing the sequential clotting stages. An important hemostatic parameter, prothrombin time, was quantitatively determined from the frequency response for different dilutions of the blood samples. The effect of a typical anticoagulant drug (heparin) on the prothrombin time was exemplarily shown. The proposed sensor displayed a good consistency and clinical comparability with the standard coagulometric methods. Thanks to the availability of direct digital signals, excellent potentials of miniaturization and integration, the proposed sensor has promising application for point-of-care coagulation technologies.

Injected carrier concentration dependence of the expansion of single Shockley-type stacking faults in 4H-SiC PiN diodes

NASA Astrophysics Data System (ADS)

Tawara, T.; Matsunaga, S.; Fujimoto, T.; Ryo, M.; Miyazato, M.; Miyazawa, T.; Takenaka, K.; Miyajima, M.; Otsuki, A.; Yonezawa, Y.; Kato, T.; Okumura, H.; Kimoto, T.; Tsuchida, H.

2018-01-01

We investigated the relationship between the dislocation velocity and the injected carrier concentration on the expansion of single Shockley-type stacking faults by monitoring the electroluminescence from 4H-SiC PiN diodes with various anode Al concentrations. The injected carrier concentration was calculated using a device simulation that took into account the measured accumulated charge in the drift layer during diode turn-off. The dislocation velocity was strongly dependent on the injected hole concentration, which represents the excess carrier concentration. The activation energy of the dislocation velocity was quite small (below 0.001 eV between 310 and 386 K) over a fixed range of hole concentrations. The average threshold hole concentration required for the expansion of bar-shaped single Shockley-type stacking faults at the interface between the buffer layer and the substrate was determined to be 1.6-2.5 × 1016 cm-3 for diodes with a p-type epitaxial anode with various Al concentrations.

Gas sensor

DOEpatents

Schmid, Andreas K.; Mascaraque, Arantzazu; Santos, Benito; de la Figuera, Juan

2014-09-09

A gas sensor is described which incorporates a sensor stack comprising a first film layer of a ferromagnetic material, a spacer layer, and a second film layer of the ferromagnetic material. The first film layer is fabricated so that it exhibits a dependence of its magnetic anisotropy direction on the presence of a gas, That is, the orientation of the easy axis of magnetization will flip from out-of-plane to in-plane when the gas to be detected is present in sufficient concentration. By monitoring the change in resistance of the sensor stack when the orientation of the first layer's magnetization changes, and correlating that change with temperature one can determine both the identity and relative concentration of the detected gas. In one embodiment the stack sensor comprises a top ferromagnetic layer two mono layers thick of cobalt deposited upon a spacer layer of ruthenium, which in turn has a second layer of cobalt disposed on its other side, this second cobalt layer in contact with a programmable heater chip.

A Urea Biosensor from Stacked Sol-Gel Films with Immobilized Nile Blue Chromoionophore and Urease Enzyme

PubMed Central

Alqasaimeh, Muawia Salameh; Heng, Lee Yook; Ahmad, Musa

2007-01-01

An optical urea biosensor was fabricated by stacking several layers of sol-gel films. The stacking of the sol-gel films allowed the immobilization of a Nile Blue chromoionophore (ETH 5294) and urease enzyme separately without the need of any chemical attachment procedure. The absorbance response of the biosensor was monitored at 550 nm, i.e. the deprotonation of the chromoionophore. This multi-layer sol-gel film format enabled higher enzyme loading in the biosensor to be achieved. The urea optical biosensor constructed from three layers of sol-gel films that contained urease demonstrated a much wider linear response range of up to 100 mM urea when compared with biosensors that constructed from 1-2 layers of films. Analysis of urea in urine samples with this optical urea biosensor yielded results similar to that determined by a spectrophotometric method using the reagent p-dimethylaminobenzaldehyde (R2 = 0.982, n = 6). The average recovery of urea from urine samples using this urea biosensor is approximately 103%.

40 CFR 60.36e - Inspection guidelines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... bypass stack components; (xvi) Ensure proper calibration of thermocouples, sorbent feed systems and any...) for proper operation, if applicable; (ii) Ensure proper calibration of thermocouples, sorbent feed...

40 CFR 60.36e - Inspection guidelines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... bypass stack components; (xvi) Ensure proper calibration of thermocouples, sorbent feed systems and any...) for proper operation, if applicable; (ii) Ensure proper calibration of thermocouples, sorbent feed...

40 CFR 60.36e - Inspection guidelines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... bypass stack components; (xvi) Ensure proper calibration of thermocouples, sorbent feed systems and any...) for proper operation, if applicable; (ii) Ensure proper calibration of thermocouples, sorbent feed...

Performance Testing of Tracer Gas and Tracer Aerosol Detectors for use in Radionuclide NESHAP Compliance Testing

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

Fuehne, David Patrick; Lattin, Rebecca Renee

The Rad-NESHAP program, part of the Air Quality Compliance team of LANL’s Compliance Programs group (EPC-CP), and the Radiation Instrumentation & Calibration team, part of the Radiation Protection Services group (RP-SVS), frequently partner on issues relating to characterizing air flow streams. This memo documents the most recent example of this partnership, involving performance testing of sulfur hexafluoride detectors for use in stack gas mixing tests. Additionally, members of the Rad-NESHAP program performed a functional trending test on a pair of optical particle counters, comparing results from a non-calibrated instrument to a calibrated instrument. Prior to commissioning a new stack samplingmore » system, the ANSI Standard for stack sampling requires that the stack sample location must meet several criteria, including uniformity of tracer gas and aerosol mixing in the air stream. For these mix tests, tracer media (sulfur hexafluoride gas or liquid oil aerosol particles) are injected into the stack air stream and the resulting air concentrations are measured across the plane of the stack at the proposed sampling location. The coefficient of variation of these media concentrations must be under 20% when evaluated over the central 2/3 area of the stack or duct. The instruments which measure these air concentrations must be tested prior to the stack tests in order to ensure their linear response to varying air concentrations of either tracer gas or tracer aerosol. The instruments used in tracer gas and aerosol mix testing cannot be calibrated by the LANL Standards and Calibration Laboratory, so they would normally be sent off-site for factory calibration by the vendor. Operational requirements can prevent formal factory calibration of some instruments after they have been used in hazardous settings, e.g., within a radiological facility with potential airborne contamination. The performance tests described in this document are intended to demonstrate the reliable performance of the test instruments for the specific tests used in stack flow characterization.« less

Performance of PZT stacks under high-field electric cycling at various temperatures in heavy-duty diesel engine fuel injectors

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

Wang, Hong; Lin, Hua-Tay; Stafford, Mr Randy

2016-01-01

Testing and characterization of large prototype lead zirconate titanate (PZT) stacks present substantial technical challenges to electronic systems. The work in this study shows that an alternative approach can be pursued by using subunits extracted from prototype stacks. Piezoelectric and dielectric integrity was maintained even though the PZT plate specimens experienced an additional loading process involved with the extraction after factory poling. Extracted 10-layer plate specimens were studied by an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 108 cycles, both at room temperature (22 C) and at 50 C. The elevated temperature had amore » defined impact on the fatigue of PZT stacks. About 48 and 28% reductions were observed in the piezoelectric and dielectric coefficients, respectively, after 108 cycles at 50 C, compared with reductions of 25 and 15% in the respective coefficients at 22 C. At the same time, the loss tangent varied to a limited extent. The evolution of PZT electrode interfacial layers or nearby dielectric layers should account for the difference in the fatigue rates of piezoelectric and dielectric coefficients. But the basic contribution to observed fatigue may result from the buildup of a bias field that finally suppressed the motion of the domain walls. Finally, monitoring of dielectric coefficients can be an effective tool for on-line lifetime prediction of PZT stacks in service if a failure criterion is defined properly.« less

Performance of PZT stacks under high-field electric cycling at various temperatures in heavy-duty diesel engine fuel injectors

NASA Astrophysics Data System (ADS)

Wang, Hong; Lee, Sung-Min; Lin, Hua-Tay; Stafford, Randy

2016-04-01

Testing and characterization of large prototype lead zirconate titanate (PZT) stacks present substantial technical challenges to electronic systems. The work in this study shows that an alternative approach can be pursued by using subunits extracted from prototype stacks. Piezoelectric and dielectric integrity was maintained even though the PZT plate specimens experienced an additional loading process involved with the extraction after factory poling. Extracted 10-layer plate specimens were studied by an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 108 cycles, both at room temperature (22°C) and at 50°C. The elevated temperature had a defined impact on the fatigue of PZT stacks. About 48 and 28% reductions were observed in the piezoelectric and dielectric coefficients, respectively, after 108 cycles at 50°C, compared with reductions of 25 and 15% in the respective coefficients at 22°C. At the same time, the loss tangent varied to a limited extent. The evolution of PZT-electrode interfacial layers or nearby dielectric layers should account for the difference in the fatigue rates of piezoelectric and dielectric coefficients. But the basic contribution to observed fatigue may result from the buildup of a bias field that finally suppressed the motion of the domain walls. Finally, monitoring of dielectric coefficients can be an effective tool for on-line lifetime prediction of PZT stacks in service if a failure criterion is defined properly.

RECOMMENDED OPERATING PROCEDURE NO. 51: GLASS SOURCE ASSESSMENT SAMPLING SYSTEM (GLASS SASS)

EPA Science Inventory

The report is a recommended operating procedure (ROP), prepared for use in research activities conducted by EPA's Air and Energy Engineering Research Laboratory (AEERL). he method described is applicable to the stack sampling of flue gas from a rotary kiln and to associated equip...

Process test plan, phase II: waste retrieval sluicing system emissions collection

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

POWERS, R.L.

1999-06-01

This Process Test Plan is prepared to continue from HNF-3733 which was Phase I of the test. Supplemental operational controls and sampling requirements are defined to safely obtain gas samples from the 296-C-006 ventilation system stack during active operation of the sluicing equipment.

40 CFR 75.57 - General recordkeeping provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... stack gas (percent H2O, rounded to the nearest tenth). If the continuous moisture monitoring system... record daily the following information for CO2 mass emissions: (i) Date; (ii) Daily combustion-formed CO2... whether optional procedure to adjust combustion-formed CO2 mass emissions for carbon retained in flyash...

40 CFR 75.57 - General recordkeeping provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... stack gas (percent H2O, rounded to the nearest tenth). If the continuous moisture monitoring system... record daily the following information for CO2 mass emissions: (i) Date; (ii) Daily combustion-formed CO2... whether optional procedure to adjust combustion-formed CO2 mass emissions for carbon retained in flyash...

40 CFR 75.57 - General recordkeeping provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... stack gas (percent H2O, rounded to the nearest tenth). If the continuous moisture monitoring system... record daily the following information for CO2 mass emissions: (i) Date; (ii) Daily combustion-formed CO2... whether optional procedure to adjust combustion-formed CO2 mass emissions for carbon retained in flyash...

40 CFR 75.57 - General recordkeeping provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... stack gas (percent H2O, rounded to the nearest tenth). If the continuous moisture monitoring system... record daily the following information for CO2 mass emissions: (i) Date; (ii) Daily combustion-formed CO2... whether optional procedure to adjust combustion-formed CO2 mass emissions for carbon retained in flyash...

40 CFR 270.62 - Hazardous waste incinerator permits.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., at the request of the applicant when good cause is shown. The permit may be modified to reflect the...) Stack gas monitoring and pollution control equipment. (H) Nozzle and burner design. (I) Construction... imminent hazard to human health or the environment; (iii) The trial burn will help the Director to...

40 CFR 270.62 - Hazardous waste incinerator permits.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., at the request of the applicant when good cause is shown. The permit may be modified to reflect the...) Stack gas monitoring and pollution control equipment. (H) Nozzle and burner design. (I) Construction... imminent hazard to human health or the environment; (iii) The trial burn will help the Director to...

40 CFR 270.62 - Hazardous waste incinerator permits.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., at the request of the applicant when good cause is shown. The permit may be modified to reflect the...) Stack gas monitoring and pollution control equipment. (H) Nozzle and burner design. (I) Construction... imminent hazard to human health or the environment; (iii) The trial burn will help the Director to...

40 CFR 270.62 - Hazardous waste incinerator permits.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., at the request of the applicant when good cause is shown. The permit may be modified to reflect the...) Stack gas monitoring and pollution control equipment. (H) Nozzle and burner design. (I) Construction... imminent hazard to human health or the environment; (iii) The trial burn will help the Director to...

40 CFR 60.714 - Installation of monitoring devices and recordkeeping.

Code of Federal Regulations, 2013 CFR

2013-07-01

... by the test method described in § 60.713(b)(1) (liquid material balance) shall maintain records of... equipment controlled by a carbon adsorption system and demonstrating compliance by the procedures described..., as appropriate. (1) For carbon adsorption systems with a common exhaust stack for all the individual...

40 CFR 60.714 - Installation of monitoring devices and recordkeeping.

Code of Federal Regulations, 2014 CFR

2014-07-01

... by the test method described in § 60.713(b)(1) (liquid material balance) shall maintain records of... equipment controlled by a carbon adsorption system and demonstrating compliance by the procedures described..., as appropriate. (1) For carbon adsorption systems with a common exhaust stack for all the individual...

40 CFR 60.714 - Installation of monitoring devices and recordkeeping.

Code of Federal Regulations, 2012 CFR

2012-07-01

... by the test method described in § 60.713(b)(1) (liquid material balance) shall maintain records of... equipment controlled by a carbon adsorption system and demonstrating compliance by the procedures described..., as appropriate. (1) For carbon adsorption systems with a common exhaust stack for all the individual...

40 CFR 60.714 - Installation of monitoring devices and recordkeeping.

Code of Federal Regulations, 2010 CFR

2010-07-01

... by the test method described in § 60.713(b)(1) (liquid material balance) shall maintain records of... equipment controlled by a carbon adsorption system and demonstrating compliance by the procedures described..., as appropriate. (1) For carbon adsorption systems with a common exhaust stack for all the individual...

40 CFR 60.714 - Installation of monitoring devices and recordkeeping.

Code of Federal Regulations, 2011 CFR

2011-07-01

... by the test method described in § 60.713(b)(1) (liquid material balance) shall maintain records of... equipment controlled by a carbon adsorption system and demonstrating compliance by the procedures described..., as appropriate. (1) For carbon adsorption systems with a common exhaust stack for all the individual...

A twice-paired watershed experimental design to assess stacked practices through field-edge monitoring

USDA-ARS?s Scientific Manuscript database

To improve our ability to reduce nutrient losses from agricultural lands to receiving waters, comprehensive approaches that employ a variety of conservation practices placed within and below field edges will be needed. There is a need to obtain experimental data to better understand how conservation...

40 CFR 52.2565 - Original identification of plan.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Amended Regulations VI and VII, and an Identification and Analysis of the Impact of the 1979 West Virginia... State of West Virginia on November 4, 1983 which establishes an Ambient Air Quality Monitoring Network...) Revision to the State implementation plan consisting of a good engineering practice (GEP) for stack heights...

40 CFR 52.2565 - Original identification of plan.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Amended Regulations VI and VII, and an Identification and Analysis of the Impact of the 1979 West Virginia... State of West Virginia on November 4, 1983 which establishes an Ambient Air Quality Monitoring Network...) Revision to the State implementation plan consisting of a good engineering practice (GEP) for stack heights...

40 CFR 52.2565 - Original identification of plan.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Amended Regulations VI and VII, and an Identification and Analysis of the Impact of the 1979 West Virginia... State of West Virginia on November 4, 1983 which establishes an Ambient Air Quality Monitoring Network...) Revision to the State implementation plan consisting of a good engineering practice (GEP) for stack heights...

40 CFR 52.2565 - Original identification of plan.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) Amended Regulations VI and VII, and an Identification and Analysis of the Impact of the 1979 West Virginia... State of West Virginia on November 4, 1983 which establishes an Ambient Air Quality Monitoring Network...) Revision to the State implementation plan consisting of a good engineering practice (GEP) for stack heights...

Test/QA Plan for Verification of Cavity Ringdown Spectroscopy Systems for Ammonia Monitoring in Stack Gas

EPA Science Inventory

The purpose of the cavity ringdown spectroscopy (CRDS) technology test and quality assurance plan is to specify procedures for a verification test applicable to commercial cavity ringdown spectroscopy technologies. The purpose of the verification test is to evaluate the performa...

40 CFR 63.9631 - What are my monitoring requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... inspections, vibration detectors, or equivalent means. (b) Except as provided in paragraph (c) of this section... average opacity of emissions exiting each control device stack according to the requirements in § 63.9633... pollution control device other than a baghouse, wet scrubber, dry electrostatic precipitator, or wet...

40 CFR 63.9631 - What are my monitoring requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

... inspections, vibration detectors, or equivalent means. (b) Except as provided in paragraph (c) of this section... average opacity of emissions exiting each control device stack according to the requirements in § 63.9633... pollution control device other than a baghouse, wet scrubber, dry electrostatic precipitator, or wet...

40 CFR 63.9631 - What are my monitoring requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

... inspections, vibration detectors, or equivalent means. (b) Except as provided in paragraph (c) of this section... average opacity of emissions exiting each control device stack according to the requirements in § 63.9633... pollution control device other than a baghouse, wet scrubber, dry electrostatic precipitator, or wet...

DETECTION OF MERCURIC BROMIDE IN A GAS PHASE FLOW CELL BY LASER PHOTOFRAGMENT FLUORESCENCE SPECTROSCOPY. (R825380)

EPA Science Inventory

Photofragment fluorescence (PFF) spectroscopy offers real-time monitoring
capability with high-analytical sensitivity and selectivity for volatile mercury
compounds found in process gas streams, such as incinerator stacks. In this
work, low concentrations (6 ppb to...

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

Gottesfeld, S.

The fuel cell is the most efficient device for the conversion of hydrogen fuel to electric power. As such, the fuel cell represents a key element in efforts to demonstrate and implement hydrogen fuel utilization for electric power generation. The low temperature, polymer electrolyte membrane fuel cell (PEMFC) has recently been identified as an attractive option for stationary power generation, based on the relatively simple and benign materials employed, the zero-emission character of the device, and the expected high power density, high reliability and low cost. However, a PEMFC stack fueled by hydrogen with the combined properties of low cost,more » high performance and high reliability has not yet been demonstrated. Demonstration of such a stack will remove a significant barrier to implementation of this advanced technology for electric power generation from hydrogen. Work done in the past at LANL on the development of components and materials, particularly on advanced membrane/electrode assemblies (MEAs), has contributed significantly to the capability to demonstrate in the foreseeable future a PEMFC stack with the combined characteristics described above. A joint effort between LANL and an industrial stack manufacturer will result in the demonstration of such a fuel cell stack for stationary power generation. The stack could operate on hydrogen fuel derived from either natural gas or from renewable sources. The technical plan includes collaboration with a stack manufacturer (CRADA). It stresses the special requirements from a PEMFC in stationary power generation, particularly maximization of the energy conversion efficiency, extension of useful life to the 10 hours time scale and tolerance to impurities from the reforming of natural gas.« less

Simulation-based Testing of Control Software

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

Ozmen, Ozgur; Nutaro, James J.; Sanyal, Jibonananda

It is impossible to adequately test complex software by examining its operation in a physical prototype of the system monitored. Adequate test coverage can require millions of test cases, and the cost of equipment prototypes combined with the real-time constraints of testing with them makes it infeasible to sample more than a small number of these tests. Model based testing seeks to avoid this problem by allowing for large numbers of relatively inexpensive virtual prototypes that operate in simulation time at a speed limited only by the available computing resources. In this report, we describe how a computer system emulatormore » can be used as part of a model based testing environment; specifically, we show that a complete software stack including operating system and application software - can be deployed within a simulated environment, and that these simulations can proceed as fast as possible. To illustrate this approach to model based testing, we describe how it is being used to test several building control systems that act to coordinate air conditioning loads for the purpose of reducing peak demand. These tests involve the use of ADEVS (A Discrete Event System Simulator) and QEMU (Quick Emulator) to host the operational software within the simulation, and a building model developed with the MODELICA programming language using Buildings Library and packaged as an FMU (Functional Mock-up Unit) that serves as the virtual test environment.« less

A quick method for AlCu interconnect electromigration performance predicting and monitoring

NASA Astrophysics Data System (ADS)

Zhang, Wenjie; Yi, Leeward; Tao, Kai; Ma, Yue; Chang, Pingyi; Mao, Duli; Wu, Jin; Zou, S. C.

2006-05-01

The film properties and microstructures of (bottom)Si/SiO2/Ti(top) and (bottom)Si/SiO2/Ti/TiN/AlCu(top) stacks deposited by different processes were characterized. The resistivities of thin Ti films and the reflectivities of AlCu alloy films were found to correlate with the microstructure as well as the mean time to failure (MTTF) in the electromigration (EM) test. A quick-turn monitor for AlCu interconnect reliability in the semiconductor manufacturing industry was established.

Electrochemical characterization of Fe-air rechargeable oxide battery in planar solid oxide cell stacks

NASA Astrophysics Data System (ADS)

Fang, Qingping; Berger, Cornelius M.; Menzler, Norbert H.; Bram, Martin; Blum, Ludger

2016-12-01

Iron-air rechargeable oxide batteries (ROB) comprising solid oxide cells (SOC) as energy converters and Fe/metal-oxide redox couples were characterized using planar SOC stacks. The charge and discharge of the battery correspond to the operations in the electrolysis and fuel cell modes, respectively, but with a stagnant atmosphere consisting of hydrogen and steam. A novel method was employed to establish the stagnant atmosphere for battery testing during normal SOC operation without complicated modification to the test bench and stack/battery concept. Manipulation of the gas compositions during battery operation was not necessary, but the influence of the leakage current from the testing system had to be considered. Batteries incorporating Fe2O3/8YSZ, Fe2O3/CaO and Fe2O3/ZrO2 storage materials were characterized at 800 °C. A maximum charge capacity of 30.4 Ah per layer (with an 80 cm2 active cell area) with ∼0.5 mol Fe was reached with a current of 12 A. The charge capacity lost 11% after ∼130 ROB cycles due to the increased agglomeration of active materials and formation of a dense oxide layer on the surface. The round trip efficiencies of the tested batteries were ≤84% due to the large internal resistance. With state-of-the-art cells, the round trip efficiency can be further improved.

Temporal changes in shear velocity from ambient noise at New Zealand geothermal fields

NASA Astrophysics Data System (ADS)

Civilini, F.; Savage, M. K.; Townend, J.

2016-12-01

We use ambient noise to compare shear velocity changes with geothermal production processes at the Ngatamariki and Rotokawa geothermal fields, located in the central North Island of New Zealand. We calculate shear velocity changes through an analysis of cross correlation functions of diffusive seismic wavefields between stations, which are proportional to Green's functions of the station path. Electricity production at Ngatamariki uses an 82 MW binary type power station manufactured by Ormat Technologies, which began operations in mid-2013 and is owned and operated by Mighty River Power. The "Nga Awa Purua" triple flash power plant at the Rotokawa geothermal field was established in 2010 with parnership between Mighty River Power and Tauhara North No. 2 trust and currently operates 174 MW of generation. The seismometers of both networks, deployed primarily to observe microseismicity within the field, were installed prior to well stimulation and the start of production. Although cultural noise dominates the energy spectrum, a strong natural ambient noise signal can be detected when filtering below 1 Hz. Despite similar noise settings, the signal-to-noise ratio of cross correlation stacks at Rotokawa was more than two times greater than at Ngatamariki. We use stacks of cross correlations between stations prior to the onset of production as references, and compare them with cross correlations of moving stacks in time periods of well stimulation and the onset of electricity production.

Deployment of 464XLAT (RFC6877) alongside IPv6-only CPU resources at WLCG sites

NASA Astrophysics Data System (ADS)

Froy, T. S.; Traynor, D. P.; Walker, C. J.

2017-10-01

IPv4 is now officially deprecated by the IETF. A significant amount of effort has already been expended by the HEPiX IPv6 Working Group on testing dual-stacked hosts and IPv6-only CPU resources. Dual-stack adds complexity and administrative overhead to sites that may already be starved of resource. This has resulted in a very slow uptake of IPv6 from WLCG sites. 464XLAT (RFC6877) is intended for IPv6 single-stack environments that require the ability to communicate with IPv4-only endpoints. This paper will present a deployment strategy for 464XLAT, operational experiences of using 464XLAT in production at a WLCG site and important information to consider prior to deploying 464XLAT.

Time-lapse processing of 2D seismic profiles with testing of static correction methods at the CO2 injection site Ketzin (Germany)

NASA Astrophysics Data System (ADS)

Bergmann, Peter; Yang, Can; Lüth, Stefan; Juhlin, Christopher; Cosma, Calin

2011-09-01

The Ketzin project provides an experimental pilot test site for the geological storage of CO2. Seismic monitoring of the Ketzin site comprises 2D and 3D time-lapse experiments with baseline experiments in 2005. The first repeat 2D survey was acquired in 2009 after 22 kt of CO2 had been injected into the Stuttgart Formation at approximately 630 m depth. Main objectives of the 2D seismic surveys were the imaging of geological structures, detection of injected CO2, and comparison with the 3D surveys. Time-lapse processing highlighted the importance of detailed static corrections to account for travel time delays, which are attributed to different near-surface velocities during the survey periods. Compensation for these delays has been performed using both pre-stack static corrections and post-stack static corrections. The pre-stack method decomposes the travel time delays of baseline and repeat datasets in a surface consistent manner, while the latter cross-aligns baseline and repeat stacked sections along a reference horizon. Application of the static corrections improves the S/N ratio of the time-lapse sections significantly. Based on our results, it is recommended to apply a combination of both corrections when time-lapse processing faces considerable near-surface velocity changes. Processing of the datasets demonstrates that the decomposed solution of the pre-stack static corrections can be used for interpretation of changes in near-surface velocities. In particular, the long-wavelength part of the solution indicates an increase in soil moisture or a shallower groundwater table in the repeat survey. Comparison with the processing results of 2D and 3D surveys shows that both image the subsurface, but with local variations which are mainly associated to differences in the acquisition geometry and source types used. Interpretation of baseline and repeat stacks shows that no CO2 related time-lapse signature is observable where the 2D lines allow monitoring of the reservoir. This finding is consistent with the time-lapse results of the 3D surveys, which show an increase in reflection amplitude centered around the injection well. To further investigate any potential CO2 signature, an amplitude versus offset (AVO) analysis was performed. The time-lapse analysis of the AVO does not indicate the presence of CO2, as expected, but shows signs of a pressure response in the repeat data.

29 CFR 780.151 - Particular operations on commodities.

Code of Federal Regulations, 2010 CFR

2010-07-01

... AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT... 3(f): (a) Grain, seed, and forage crops. Weighing, binning, stacking, drying, cleaning, grading...

29 CFR 780.151 - Particular operations on commodities.

Code of Federal Regulations, 2013 CFR

2013-07-01

... AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT... 3(f): (a) Grain, seed, and forage crops. Weighing, binning, stacking, drying, cleaning, grading...

29 CFR 780.151 - Particular operations on commodities.

Code of Federal Regulations, 2014 CFR

2014-07-01

... AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT... 3(f): (a) Grain, seed, and forage crops. Weighing, binning, stacking, drying, cleaning, grading...

29 CFR 780.151 - Particular operations on commodities.

Code of Federal Regulations, 2011 CFR

2011-07-01

... AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT... 3(f): (a) Grain, seed, and forage crops. Weighing, binning, stacking, drying, cleaning, grading...

29 CFR 780.151 - Particular operations on commodities.

Code of Federal Regulations, 2012 CFR

2012-07-01

... AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT... 3(f): (a) Grain, seed, and forage crops. Weighing, binning, stacking, drying, cleaning, grading...

The thermal stability of Pt/epitaxial Gd2O3/Si stacks and its dependence on heat-treatment ambient

NASA Astrophysics Data System (ADS)

Lipp, E.; Osten, H. J.; Eizenberg, M.

2009-12-01

The stability of Pt/epitaxial Gd2O3/Si stacks is studied by monitoring the chemical and electrical properties following heat treatments in forming gas and in vacuum at temperatures between 400 and 650 °C. Our results show that stack instability is realized via diffusion of Gd through the Pt grain boundaries, which was observed after forming-gas annealing at 550 °C for 30 min. The Gd diffusion kinetics in forming gas is studied by secondary ion mass spectrometry analysis, showing that the diffusion process occurs according to C-type kinetics with an activation energy of 0.73±0.04 eV. Following vacuum heat treatments at 600 °C for 30 min, Si outdiffusion is observed, in addition to Gd outdiffusion. Si outdiffusion results in the formation of PtSi clusters on the metal surface following vacuum annealing at 650 °C. In contrast, in the case of forming-gas treatments, Si diffusion and silicide formation were detected only after annealing at 700 °C. The better stability of Pt/Gd2O3/Si stacks in forming gas is correlated with the content of oxygen in the Pt layer during the treatment.