PROCESS WATER BUILDING, TRA605. FLASH EVAPORATORS ARE PLACED ON UPPER ...

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

PROCESS WATER BUILDING, TRA-605. FLASH EVAPORATORS ARE PLACED ON UPPER LEVEL OF EAST SIDE OF BUILDING. WALLS WILL BE FORMED AROUND THEM. WORKING RESERVOIR BEYOND. CAMERA FACING EASTERLY. EXHAUST AIR STACK IS UNDER CONSTRUCTION AT RIGHT OF VIEW. INL NEGATIVE NO. 2579. Unknown Photographer, 6/18/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Performance of air-cathode stacked microbial fuel cells systems for wastewater treatment and electricity production.

PubMed

Estrada-Arriaga, Edson Baltazar; Guillen-Alonso, Yvonne; Morales-Morales, Cornelio; García-Sánchez, Liliana; Bahena-Bahena, Erick Obed; Guadarrama-Pérez, Oscar; Loyola-Morales, Félix

2017-07-01

Two different air-cathode stacked microbial fuel cell (MFC) configurations were evaluated under continuous flow during the treatment of municipal wastewater and electricity production at a hydraulic retention time (HRT) of 3, 1, and 0.5 d. Stacked MFC 1 was formed by 20 individual air-cathode MFC units. The second stacked MFC (stacked MFC 2) consisted of 40 air-cathode MFC units placed in a shared reactor. The maximum voltages produced at closed circuit (1,000 Ω) were 170 mV for stacked MFC 1 and 94 mV for stacked MFC 2. Different power densities in each MFC unit were obtained due to a potential drop phenomenon and to a change in chemical oxygen demand (COD) concentrations inside reactors. The maximum power densities from individual MFC units were up to 1,107 mW/m 2 for stacked MFC 1 and up to 472 mW/m 2 for stacked MFC 2. The maximum power densities in stacked MFC 1 and MFC 2 connected in series were 79 mW/m 2 and 4 mW/m 2 , respectively. Electricity generation and COD removal efficiencies were reduced when the HRT was decreased. High removal efficiencies of 84% of COD, 47% of total nitrogen, and 30% of total phosphorus were obtained during municipal wastewater treatment.

40 CFR Appendix Xi to Part 266 - Lead-Bearing Materials That May be Processed in Exempt Lead Smelters

Code of Federal Regulations, 2012 CFR

2012-07-01

... analyses Acid filters Baghouse bags Clothing (e.g., coveralls, aprons, shoes, hats, gloves) Sweepings Air filter bags and cartridges Respiratory cartridge filters Shop abrasives Stacking boards Waste shipping... pallets Water treatment sludges, filter cakes, residues, and solids Emission control dusts, sludges...

40 CFR Appendix Xi to Part 266 - Lead-Bearing Materials That May be Processed in Exempt Lead Smelters

Code of Federal Regulations, 2013 CFR

2013-07-01

... analyses Acid filters Baghouse bags Clothing (e.g., coveralls, aprons, shoes, hats, gloves) Sweepings Air filter bags and cartridges Respiratory cartridge filters Shop abrasives Stacking boards Waste shipping... pallets Water treatment sludges, filter cakes, residues, and solids Emission control dusts, sludges...

40 CFR Appendix Xi to Part 266 - Lead-Bearing Materials That May be Processed in Exempt Lead Smelters

Code of Federal Regulations, 2014 CFR

2014-07-01

... analyses Acid filters Baghouse bags Clothing (e.g., coveralls, aprons, shoes, hats, gloves) Sweepings Air filter bags and cartridges Respiratory cartridge filters Shop abrasives Stacking boards Waste shipping... pallets Water treatment sludges, filter cakes, residues, and solids Emission control dusts, sludges...

40 CFR Appendix Xi to Part 266 - Lead-Bearing Materials That May be Processed in Exempt Lead Smelters

Code of Federal Regulations, 2011 CFR

2011-07-01

... analyses Acid filters Baghouse bags Clothing (e.g., coveralls, aprons, shoes, hats, gloves) Sweepings Air filter bags and cartridges Respiratory cartridge filters Shop abrasives Stacking boards Waste shipping... pallets Water treatment sludges, filter cakes, residues, and solids Emission control dusts, sludges...

40 CFR Appendix Xi to Part 266 - Lead-Bearing Materials That May be Processed in Exempt Lead Smelters

Code of Federal Regulations, 2010 CFR

2010-07-01

... analyses Acid filters Baghouse bags Clothing (e.g., coveralls, aprons, shoes, hats, gloves) Sweepings Air filter bags and cartridges Respiratory cartridge filters Shop abrasives Stacking boards Waste shipping... pallets Water treatment sludges, filter cakes, residues, and solids Emission control dusts, sludges...

Image transfer by cascaded stack of photonic crystal and air layers.

PubMed

Shen, C; Michielsen, K; De Raedt, H

2006-01-23

We demonstrate image transfer by a cascaded stack consisting of two and three triangular-lattice photonic crystal slabs separated by air. The quality of the image transfered by the stack is sensitive to the air/photonic crystal interface termination and the frequency. Depending on the frequency and the surface termination, the image can be transfered by the stack with very little deterioration of the resolution, that is the resolution of the final image is approximately the same as the resolution of the image formed behind one single photonic crystal slab.

Development of 3 and 5kW Fuel Cell Power Plants

DTIC Science & Technology

1985-12-12

automotive type air -cooled (cross-flow) copper heat exchanger (Figure 7.7) was used for water reclamation. A 48V, 0.5A brushless DC blower was used to...and the balance is combusted in ’a burner to supply heat required for the endothermic reforming process. The phosphoric acid fuel cell stack is air ...the use of inter- changeable power conditioners . A microprocessor based con- troller provides event sequencing and system. control during startup

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

Demonstration of Nautilus Centripetal Capillary Condenser Technology

NASA Technical Reports Server (NTRS)

Wheeler, RIchard; Tang, Linh; Wambolt, Spencer; Golliher, Eric; Agui, Juan

2016-01-01

This paper describes the results of a proof of concept effort for development of a Nautilus Centripetal Capillary Condenser (NCCC or NC3) used for microgravity compatible water recovery from moist air with integral passive phase separation. Removal of liquid condensate from the air stream exiting a condenser is readily performed here on Earth. In order to perform this function in space however, without gravity or mechanical action, other tactics including utilization of inertial, drag and capillary forces are required. Within the NC3, liquid water forms via condensation on cold condenser surfaces as humid air passes along multiple spiral channels, each in its own plane, all together forming a stacked plate assembly. Non-mechanical inertial forces are employed to transfer condensate, as it forms, via centripetal action to the outer perimeter of each channel. A V-shaped groove, constructed on this outer edge of the spiral channel, increases local capillary forces thereby retaining the liquid. Air drag then pulls the liquid along to a collection region near the center of the device. Dry air produced by each parallel spiral channel is combined in a common orthogonal, out-of-plane conduit passing down the axial center of the stacked device. Similarly, the parallel condensate streams are combined and removed from the condenser/separator through yet another out-of-plane axial conduit. NC3 is an integration of conventional finned condenser operation, combined with static phase separation and capillary transport phenomena. A Mars' transit mission would be a logical application for this technology where gravity is absent and the use of vibrating, energy-intensive, motor-driven centrifugal separators is undesired. Here a vapor stream from either the Heat Melt Compactor or the Carbon dioxide Reduction Assembly, for example, would be dried to a dew point of 10 deg using a passive NC3 condenser/separator with the precious water condensate recycled to the water bus.

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.

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.

STEAM PLANT, TRA609. SECTION A SHOWS FEATURES OF NORTH/SOUTH AXIS: ...

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

STEAM PLANT, TRA-609. SECTION A SHOWS FEATURES OF NORTH/SOUTH AXIS: STEAM GENERATOR AND CATWALK, STACK, DEGREASER FEED WATER HEATER IN PENTHOUSE, MEZZANINE, SURGE TANK PIT (BELOW GROUND LEVEL). UTILITY ROOM SHOWS DIESEL ENGINE GENERATORS, AIR TANKS, STARTING AIR COMPRESSORS. OUTSIDE SOUTH END ARE EXHAUST MUFFLER, AIR INTAKE OIL FILTER, RADIATOR COOLING UNIT, AIR SURGE TANK. SECTION B CROSSES WEST TO EAST NEAR SOUTH END OF BUILDING TO SHOW ARRANGEMENT OF DIESEL ENGINE GENERATOR, AIR DRIER, AFTER COOLER, AIR COMPRESSOR, AND BLOWDOWN TANK. BLAW-KNOX 3150-9-2, 6/1950. INL INDEX NO. 431-0609-00-098-100018, REV. 3. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

PROCESS WATER BUILDING, TRA605. AERIAL TAKEN WHILE SEVERAL PIPE TRENCHES ...

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

PROCESS WATER BUILDING, TRA-605. AERIAL TAKEN WHILE SEVERAL PIPE TRENCHES REMAINED OPEN. CAMERA FACES EASTERLY. NOTE DUAL PIPES BETWEEN REACTOR BUILDING AND NORTH SIDE OF PROCESS WATER BUILDING. PIPING NEAR WORKING RESERVOIR HEADS FOR RETENTION RESERVOIR. PIPE FROM DEMINERALIZER ENTERS MTR FROM NORTH. SEE ALSO TRENCH FOR COOLANT AIR DUCT AT SOUTH SIDE OF MTR AND LEADING TO FAN HOUSE AND STACK. INL NEGATIVE NO. 2966-A. Unknown Photographer, 7/31/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Graphene oxide membranes with high permeability and selectivity for dehumidification of air

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

Shin, Yongsoon; Liu, Wei; Schwenzer, Birgit

Hierarchically stacked 2D graphene oxide (GO) membranes are a fascinating and promising new class of materials with the potential for radically improved water vapor/gas separation with excellent selectivity and high permeability. This paper details dehumidification results from flowing gas mixtures through free-standing GO membrane samples prepared by a casting method. The first demonstrated use of free-standing GO membranes for water vapor separation reveals outstanding water vapor permeability and H2O/N2 selectivity. Free-standing GO membranes exhibit extremely high water vapor permeability of 1.82 x 105 Barrer and a water vapor permeance of 1.01 x 10-5 mol/m2sPa, while the nitrogen permeability was belowmore » the system’s detection limit, yielding a selectivity >104 in 80% relative humidity (RH) air at 30.8 °C. The results show great potential for a range of energy conversion and environmental applications« less

Characteristic Analysis of Air-gun Source Wavelet based on the Vertical Cable Data

NASA Astrophysics Data System (ADS)

Xing, L.

2016-12-01

Air guns are important sources for marine seismic exploration. Far-field wavelets of air gun arrays, as a necessary parameter for pre-stack processing and source models, plays an important role during marine seismic data processing and interpretation. When an air gun fires, it generates a series of air bubbles. Similar to onshore seismic exploration, the water forms a plastic fluid near the bubble; the farther the air gun is located from the measurement, the more steady and more accurately represented the wavelet will be. In practice, hydrophones should be placed more than 100 m from the air gun; however, traditional seismic cables cannot meet this requirement. On the other hand, vertical cables provide a viable solution to this problem. This study uses a vertical cable to receive wavelets from 38 air guns and data are collected offshore Southeast Qiong, where the water depth is over 1000 m. In this study, the wavelets measured using this technique coincide very well with the simulated wavelets and can therefore represent the real shape of the wavelets. This experiment fills a technology gap in China.

Surface and Interface Chemistry for Gate Stacks on Silicon

NASA Astrophysics Data System (ADS)

Frank, M. M.; Chabal, Y. J.

This chapter addresses the fundamental silicon surface science associated with the continued progress of nanoelectronics along the path prescribed by Moore's law. Focus is on hydrogen passivation layers and on ultrathin oxide films encountered during silicon cleaning and gate stack formation in the fabrication of metal-oxide-semiconductor field-effect transistors (MOSFETs). Three main topics are addressed. (i) First, the current practices and understanding of silicon cleaning in aqueous solutions are reviewed, including oxidizing chemistries and cleans leading to a hydrogen passivation layer. The dependence of the final surface termination and morphology/roughness on reactant choice and pH and the influence of impurities such as dissolved oxygen or metal ions are discussed. (ii) Next, the stability of hydrogen-terminated silicon in oxidizing liquid and gas phase environments is considered. In particular, the remarkable stability of hydrogen-terminated silicon surface in pure water vapor is discussed in the context of atomic layer deposition (ALD) of high-permittivity (high-k) gate dielectrics where water is often used as an oxygen precursor. Evidence is also provided for co-operative action between oxygen and water vapor that accelerates surface oxidation in humid air. (iii) Finally, the fabrication of hafnium-, zirconium- and aluminum-based high-k gate stacks is described, focusing on the continued importance of the silicon/silicon oxide interface. This includes a review of silicon surface preparation by wet or gas phase processing and its impact on high-k nucleation during ALD growth, and the consideration of gate stack capacitance and carrier mobility. In conclusion, two issues are highlighted: the impact of oxygen vacancies on the electrical characteristics of high-k MOS devices, and the way alloyed metal ions (such as Al in Hf-based gate stacks) in contact with the interfacial silicon oxide layer can be used to control flatband and threshold voltages.

Effects of coolant parameters on steady state temperature distribution in phospheric-acid fuel cell electrode

NASA Technical Reports Server (NTRS)

Alkasab, K. A.; Abdul-Aziz, A.

1991-01-01

The influence of thermophysical properties and flow rate on the steady-state temperature distribution in a phosphoric-acid fuel cell electrode plate was experimentally investigated. An experimental setup that simulates the operating conditions prevailing in a phosphoric-acid fuel cell stack was used. The fuel cell cooling system utilized three types of coolants to remove excess heat generated in the cell electrode and to maintain a reasonably uniform temperature distribution in the electrode plate. The coolants used were water, engine oil, and air. These coolants were circulated at Reynolds number ranging from 1165 to 6165 for water; 3070 to 6864 for air; and 15 to 79 for oil. Experimental results are presented.

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.

Effect on combined cycle efficiency of stack gas temperature constraints to avoid acid corrosion

NASA Technical Reports Server (NTRS)

Nainiger, J. J.

1980-01-01

To avoid condensation of sulfuric acid in the gas turbine exhaust when burning fuel oils contaning sulfur, the exhaust stack temperature and cold-end heat exchanger surfaces must be kept above the condensation temperature. Raising the exhaust stack temperature, however, results in lower combined cycle efficiency compared to that achievable by a combined cycle burning a sulfur-free fuel. The maximum difference in efficiency between the use of sulfur-free and fuels containing 0.8 percent sulfur is found to be less than one percentage point. The effect of using a ceramic thermal barrier coating (TBC) and a fuel containing sulfur is also evaluated. The combined-cycle efficiency gain using a TBC with a fuel containing sulfur compared to a sulfur-free fuel without TBC is 0.6 to 1.0 percentage points with air-cooled gas turbines and 1.6 to 1.8 percentage points with water-cooled gas turbines.

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

IET. Stack interior. Masons lay fire brick liner, leaving air ...

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

IET. Stack interior. Masons lay fire brick liner, leaving air layer between bricks and concrete wall. Date: May 20, 1955. INEEL negative no. 55-1306 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Air stacking: effects on pulmonary function in patients with spinal muscular atrophy and in patients with congenital muscular dystrophy*,**

PubMed Central

Marques, Tanyse Bahia Carvalho; Neves, Juliana de Carvalho; Portes, Leslie Andrews; Salge, João Marcos; Zanoteli, Edmar; Reed, Umbertina Conti

2014-01-01

OBJECTIVE: Respiratory complications are the main causes of morbidity and mortality in patients with neuromuscular disease (NMD). The objectives of this study were to determine the effects that routine daily home air-stacking maneuvers have on pulmonary function in patients with spinal muscular atrophy (SMA) and in patients with congenital muscular dystrophy (CMD), as well as to identify associations between spinal deformities and the effects of the maneuvers. METHODS: Eighteen NMD patients (ten with CMD and eight with SMA) were submitted to routine daily air-stacking maneuvers at home with manual resuscitators for four to six months, undergoing pulmonary function tests before and after that period. The pulmonary function tests included measurements of FVC; PEF; maximum insufflation capacity (MIC); and assisted and unassisted peak cough flow (APCF and UPCF, respectively) with insufflations. RESULTS: After the use of home air-stacking maneuvers, there were improvements in the APCF and UPCF. In the patients without scoliosis, there was also a significant increase in FVC. When comparing patients with and without scoliosis, the increases in APCF and UPCF were more pronounced in those without scoliosis. CONCLUSIONS: Routine daily air-stacking maneuvers with a manual resuscitator appear to increase UPCF and APCF in patients with NMD, especially in those without scoliosis. PMID:25410841

Air stacking: effects on pulmonary function in patients with spinal muscular atrophy and in patients with congenital muscular dystrophy.

PubMed

Marques, Tanyse Bahia Carvalho; Neves, Juliana de Carvalho; Portes, Leslie Andrews; Salge, João Marcos; Zanoteli, Edmar; Reed, Umbertina Conti

2014-10-01

Respiratory complications are the main causes of morbidity and mortality in patients with neuromuscular disease (NMD). The objectives of this study were to determine the effects that routine daily home air-stacking maneuvers have on pulmonary function in patients with spinal muscular atrophy (SMA) and in patients with congenital muscular dystrophy (CMD), as well as to identify associations between spinal deformities and the effects of the maneuvers. Eighteen NMD patients (ten with CMD and eight with SMA) were submitted to routine daily air-stacking maneuvers at home with manual resuscitators for four to six months, undergoing pulmonary function tests before and after that period. The pulmonary function tests included measurements of FVC; PEF; maximum insufflation capacity (MIC); and assisted and unassisted peak cough flow (APCF and UPCF, respectively) with insufflations. After the use of home air-stacking maneuvers, there were improvements in the APCF and UPCF. In the patients without scoliosis, there was also a significant increase in FVC. When comparing patients with and without scoliosis, the increases in APCF and UPCF were more pronounced in those without scoliosis. Routine daily air-stacking maneuvers with a manual resuscitator appear to increase UPCF and APCF in patients with NMD, especially in those without scoliosis.

Fuel cell stack with passive air supply

DOEpatents

Ren, Xiaoming; Gottesfeld, Shimshon

2006-01-17

A fuel cell stack has a plurality of polymer electrolyte fuel cells (PEFCs) where each PEFC includes a rectangular membrane electrode assembly (MEA) having a fuel flow field along a first axis and an air flow field along a second axis perpendicular to the first axis, where the fuel flow field is long relative to the air flow field. A cathode air flow field in each PEFC has air flow channels for air flow parallel to the second axis and that directly open to atmospheric air for air diffusion within the channels into contact with the MEA.

Improve Your Boiler's Combustion Efficiency: Office of Industrial Technologies (OIT) Steam Energy Tips No.4

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

Not Available

2002-03-01

Operating your boiler with an optimum amount of excess air will minimize heat loss up the stack and improve combustion efficiency. Combustion efficiency is a measure of how effectively the heat content of a fuel is transferred into usable heat. The stack temperature and flue gas oxygen (or carbon dioxide) concentrations are primary indicators of combustion efficiency. Given complete mixing, a precise or stoichiometric amount of air is required to completely react with a given quantity of fuel. In practice, combustion conditions are never ideal, and additional or ''excess'' air must be supplied to completely burn the fuel. The correctmore » amount of excess air is determined from analyzing flue gas oxygen or carbon dioxide concentrations. Inadequate excess air results in unburned combustibles (fuel, soot, smoke, and carbon monoxide) while too much results in heat lost due to the increased flue gas flow--thus lowering the overall boiler fuel-to-steam efficiency. The table relates stack readings to boiler performance. On well-designed natural gas-fired systems, an excess air level of 10% is attainable. An often stated rule of thumb is that boiler efficiency can be increased by 1% for each 15% reduction in excess air or 40 F reduction in stack gas temperature.« less

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

The WISGSK: A computer code for the prediction of a multistage axial compressor performance with water ingestion

NASA Technical Reports Server (NTRS)

Tsuchiya, T.; Murthy, S. N. B.

1982-01-01

A computer code is presented for the prediction of off-design axial flow compressor performance with water ingestion. Four processes were considered to account for the aero-thermo-mechanical interactions during operation with air-water droplet mixture flow: (1) blade performance change, (2) centrifuging of water droplets, (3) heat and mass transfer process between the gaseous and the liquid phases and (4) droplet size redistribution due to break-up. Stage and compressor performance are obtained by a stage stacking procedure using representative veocity diagrams at a rotor inlet and outlet mean radii. The Code has options for performance estimation with (1) mixtures of gas and (2) gas-water droplet mixtures, and therefore can take into account the humidity present in ambient conditions. A test case illustrates the method of using the Code. The Code follows closely the methodology and architecture of the NASA-STGSTK Code for the estimation of axial-flow compressor performance with air flow.

Almost twenty years' search of transuranium isotopes in effluents discharged to air from nuclear power plants with VVER reactors.

PubMed

Hölgye, Z; Filgas, R

2006-04-01

Airborne effluents of 5 stacks (stacks 1-5) of three nuclear power plants, with 9 pressurized water reactors VVER of 4,520 MWe total power, were searched for transuranium isotopes in different time periods. The search started in 1985. The subject of this work is a presentation of discharge data for the period of 1998-2003 and a final evaluation. It was found that 238Pu, 239,240Pu, 241Am, 242Cm, and 244Cm can be present in airborne effluents. Transuranium isotope contents in most of the quarterly effluent samples from stacks 2, 4 and 5 were not measurable. Transuranium isotopes were present in the effluents from stack l during all 9 years of the study and from stack 3 since the 3rd quarter of 1996 as a result of a defect in the fuel cladding. A relatively high increase of transuranium isotopes in effluents from stack 3 occurred in the 3rd quarter of 1999, and a smaller increase occurred in the 3rd quarter of 2003. In each instance 242Cm prevailed in the transuranium isotope mixtures. 238Pu/239,240Pu, 241Am/239,240Pu, 242Cm/239,240Pu, and 244Cm/239,240Pu ratios in fuel for different burn-up were calculated, and comparison of these ratios in fuel and effluents was performed.

Estimates of air drying times for several hardwoods and softwoods

Treesearch

W.T. Simpson; C.A. Hart

2000-01-01

Published data on estimated air drying times of lumber are of limited usefulness because they are restricted to a specific location or to the time of year the lumber is stacked for drying. At best, these estimates give a wide range of possible times over a broad range of possible locations and stacking dates. This report describes a method for estimating air drying...

Method for estimating air-drying times of lumber

Treesearch

William T. Simpson; C. Arthur Hart

2001-01-01

Published information on estimated air-drying times of lumber is of limited usefulness because it is restricted to a specific location or to the time of year the lumber is stacked for drying. At best, these estimates give a wide range of possible times over a broad range of possible locations and stacking dates. In this paper, we describe a method for estimating air-...

40 CFR 52.2465 - Original identification of plan section.

Code of Federal Regulations, 2011 CFR

2011-07-01

... engineering practice (GEP) stack height,” “hazardous air pollutant,” “nearby,” “stationary source” and... good engineering practice (GEP) stack height requirements submitted on May 12, 1986 by the Virginia... Executive Director, Virginia State Air Pollution Control Board, transmitting the revised good engineering...

Effects of cooling system parameters on heat transfer in PAFC stack. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Ali A.

1985-01-01

Analytical and experimental study for the effects of cooling system parameters on the heat transfer and temperature distribution in the electrode plates of a phosphoric acid fuel-cell has been conducted. An experimental set-up that simulates the operating conditions prevailing in a phosphoric-acid fuel-cell stack was designed and constructed. The set-up was then used to measure the overall heat transfer coefficient, the thermal contact resistance, and the electrode temperature distribution for two different cooling plate configurations. Two types of cooling plate configurations, serpentine and straight, were tested. Air, water, and oil were used as coolants. Measurements for the heat transfer coefficient and the thermal contact resistance were made for various flow rates ranging from 16 to 88 Kg/hr, and stack clamping pressure ranging from O to 3448 Kpa. The experimental results for the overall heat transfer coefficient were utilized to derive mathematical relations for the overall heat transfer coefficient as a function of stack clamping pressure and Reynolds number for the three coolants. The empirically derived formulas were incorporated in a previously developed computer program to predict electrodes temperature distribution and the performance of the stack cooling system. The results obtained were then compared with those available in the literature. The comparison showed maximum deviation of +/- 11%.

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...

40 CFR 60.1290 - How are the stack test data used?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 6 2011-07-01 2011-07-01 false How are the stack test data used? 60.1290 Section 60.1290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Modification or Reconstruction is Commenced After June 6, 2001 Stack Testing § 60.1290 How are the stack test...

40 CFR 60.1290 - How are the stack test data used?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 7 2014-07-01 2014-07-01 false How are the stack test data used? 60.1290 Section 60.1290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Modification or Reconstruction is Commenced After June 6, 2001 Stack Testing § 60.1290 How are the stack test...

40 CFR 60.1290 - How are the stack test data used?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false How are the stack test data used? 60.1290 Section 60.1290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Modification or Reconstruction is Commenced After June 6, 2001 Stack Testing § 60.1290 How are the stack test...

40 CFR 60.1290 - How are the stack test data used?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 7 2012-07-01 2012-07-01 false How are the stack test data used? 60.1290 Section 60.1290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Modification or Reconstruction is Commenced After June 6, 2001 Stack Testing § 60.1290 How are the stack test...

40 CFR 60.1290 - How are the stack test data used?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 7 2013-07-01 2013-07-01 false How are the stack test data used? 60.1290 Section 60.1290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Modification or Reconstruction is Commenced After June 6, 2001 Stack Testing § 60.1290 How are the stack test...

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

Adelphi-Goddard emulsified fuel project. [using water/oil emulsions

NASA Technical Reports Server (NTRS)

1977-01-01

Thermal efficiency and particle emissions were studied using water/oil emulsions. These studies were done using number 2 and number 6 fuel oil. The number 6 oil had a sulfur content greater than one percent and experiments were conducted to remove the sulfur dioxide from the stack gases. Test findings include: (1) emulsion effected a reduction in soot at a low excess air levels; (2) a steam atomizing system will produce a water/oil emulsion. The fuel in the study was emulsified in the steam atomization process, hence, pre-emulsification did not yield a dramatic reduction in soot or an increase in thermal efficiency.

Annular feed air breathing fuel cell stack

DOEpatents

Wilson, Mahlon S.; Neutzler, Jay K.

1997-01-01

A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. The fuel distribution manifold is formed from a hydrophilic-like material to redistribute water produced by fuel and oxygen reacting at the cathode. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

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.

40 CFR 52.2633 - Stack height regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Stack height regulations. 52.2633 Section 52.2633 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... with the “Guideline for Determination of Good Engineering Practice Stack Height (Technical Support...

40 CFR 52.2384 - Stack height review.

Code of Federal Regulations, 2010 CFR

2010-07-01

....2384 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... affected by stack height credits greater than good engineering practice or any other prohibited dispersion... than ‘good engineering practice’ stack height or from using ‘other dispersion techniques.’ ” Thus...

40 CFR 52.383 - Stack height review.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Stack height review. 52.383 Section 52.383 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... by stack height credits greater than good engineering practice or any other prohibited dispersion...

40 CFR 51.118 - Stack height provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Stack height provisions. 51.118 Section 51.118 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Control Strategy § 51.118 Stack...

40 CFR 52.1034 - Stack height review.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Stack height review. 52.1034 Section 52.1034 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... affected by stack height credits greater than good engineering practice or any other prohibited dispersion...

40 CFR 51.164 - Stack height procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 51.164 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... source's stack height that exceeds good engineering practice or by any other dispersion technique, except... source based on a good engineering practice stack height that exceeds the height allowed by § 51.100(ii...

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.

40 CFR 61.44 - 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. 61.44 Section 61.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Firing § 61.44 Stack sampling. (a) Sources subject to § 61.42(b) shall be continuously sampled, during...

40 CFR 61.44 - 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. 61.44 Section 61.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Firing § 61.44 Stack sampling. (a) Sources subject to § 61.42(b) shall be continuously sampled, during...

Vertical feed stick wood fuel burning furnace system

DOEpatents

Hill, Richard C.

1984-01-01

A new and improved stove or furnace for efficient combustion of wood fuel including a vertical feed combustion chamber for receiving and supporting wood fuel in a vertical attitude or stack, a major upper portion of the combustion chamber column comprising a water jacket for coupling to a source of water or heat transfer fluid and for convection circulation of the fluid for confining the locus of wood fuel combustion to the bottom of the vertical gravity feed combustion chamber. A flue gas propagation delay channel extending from the laterally directed draft outlet affords delayed travel time in a high temperature environment to assure substantially complete combustion of the gaseous products of wood burning with forced air as an actively induced draft draws the fuel gas and air mixture laterally through the combustion and high temperature zone. Active sources of forced air and induced draft are included, multiple use and circuit couplings for the recovered heat, and construction features in the refractory material substructure and metal component superstructure.

Partial Section Through Stack, Water Tank, and Privy; Plan ...

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

Partial Section Through Stack, Water Tank, and Privy; Plan - Stack, Privies, & Changing Rooms; Elevation - Central of Georgia Railway, Savannah Repair Shops & Terminal Facilities, Bounded by West Broad, Jones, West Boundary & Hull Streets, Savannah, Chatham County, GA

Compressor discharge bleed air circuit in gas turbine plants and related method

DOEpatents

Anand, Ashok Kumar; Berrahou, Philip Fadhel; Jandrisevits, Michael

2002-01-01

A gas turbine system that includes a compressor, a turbine component and a load, wherein fuel and compressor discharge bleed air are supplied to a combustor and gaseous products of combustion are introduced into the turbine component and subsequently exhausted to atmosphere. A compressor discharge bleed air circuit removes bleed air from the compressor and supplies one portion of the bleed air to the combustor and another portion of the compressor discharge bleed air to an exhaust stack of the turbine component in a single cycle system, or to a heat recovery steam generator in a combined cycle system. In both systems, the bleed air diverted from the combustor may be expanded in an air expander to reduce pressure upstream of the exhaust stack or heat recovery steam generator.

Compressor discharge bleed air circuit in gas turbine plants and related method

DOEpatents

Anand, Ashok Kumar [Niskayuna, NY; Berrahou, Philip Fadhel [Latham, NY; Jandrisevits, Michael [Clifton Park, NY

2003-04-08

A gas turbine system that includes a compressor, a turbine component and a load, wherein fuel and compressor discharge bleed air are supplied to a combustor and gaseous products of combustion are introduced into the turbine component and subsequently exhausted to atmosphere. A compressor discharge bleed air circuit removes bleed air from the compressor and supplies one portion of the bleed air to the combustor and another portion of the compressor discharge bleed air to an exhaust stack of the turbine component in a single cycle system, or to a heat recovery steam generator in a combined cycle system. In both systems, the bleed air diverted from the combustor may be expanded in an air expander to reduce pressure upstream of the exhaust stack or heat recovery steam generator.

Cell module and fuel conditioner development

NASA Technical Reports Server (NTRS)

Hoover, D. Q., Jr.

1982-01-01

The phosphoric acid fuel cell module (stack) development which culminated in an 80 cell air-cooled stack with separated gas cooling and treed cooling plates is described. The performance of the 80 cell stack was approx. 100 mV per cell higher than that attained during phase 1. The components and materials performed stably for over 8000 hours in a 5 cell stack. The conceptual design of a fuel conditioning system is described.

Discrete regenerative fuel cell reduces hysteresis for sustainable cycling of water

PubMed Central

Park, Kiwon; Lee, Jungkoo; Kim, Hyung-Man; Choi, Kap-Seung; Hwang, Gunyong

2014-01-01

The discrete regenerative fuel cell is being developed as a residential power control that synchronizes with a renewables load which fluctuates significantly with the time and weather. The power of proton exchange membrane fuel cells can be scaled-up adjustably to meet the residential power demand. As a result, scale-ups from a basic unit cell with a 25 cm2 active area create a serpentine flow-field on an active area of 100 cm2 and take into account the excessive current and the remaining power obtained by stacking single cells. Operating a fuel cell utilising oxygen produced by the electrolyser instead of air improves the electrochemical reaction and the water balance. Furthermore, the performance test results with oxygen instead of air show almost no hysteresis, which results in the very stable operation of the proton exchange membrane fuel cell as well as the sustainable cycle of water by hydrogen and oxygen mediums. PMID:24699531

Effective Stack Design in Air Pollution Control.

ERIC Educational Resources Information Center

Clarke, John H.

1968-01-01

Stack design problems fall into two general caterories--(1) those of building re-entry, and (2) those of general area pollution. Extensive research has developed adequate information, available in the literature, to permit effective stack design. A major roadblock to effective design has been the strong belief by architects and engineers that high…

Stack gas treatment

DOEpatents

Reeves, Adam A.

1977-04-12

Hot stack gases transfer contained heat to a gravity flow of pebbles treated with a catalyst, cooled stacked gases and a sulfuric acid mist is withdrawn from the unit, and heat picked up by the pebbles is transferred to air for combustion or other process. The sulfuric acid (or sulfur, depending on the catalyst) is withdrawn in a recovery unit.

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.

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.

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.

40 CFR 63.421 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... entire vapor processing system except the exhaust port(s) or stack(s). Flare means a thermal oxidation...(ee). Thermal oxidation system means a combustion device used to mix and ignite fuel, air pollutants...

40 CFR 63.421 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... entire vapor processing system except the exhaust port(s) or stack(s). Flare means a thermal oxidation...(ee). Thermal oxidation system means a combustion device used to mix and ignite fuel, air pollutants...

40 CFR 63.421 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... entire vapor processing system except the exhaust port(s) or stack(s). Flare means a thermal oxidation...(ee). Thermal oxidation system means a combustion device used to mix and ignite fuel, air pollutants...

40 CFR 63.421 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... entire vapor processing system except the exhaust port(s) or stack(s). Flare means a thermal oxidation...(ee). Thermal oxidation system means a combustion device used to mix and ignite fuel, air pollutants...

PBF Cooling Tower detail. Camera facing southwest into north side ...

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

PBF Cooling Tower detail. Camera facing southwest into north side of Tower. Five horizontal layers of splash bars constitute fill decks, which will break up falling water into droplets, promoting evaporative cooling. Louvered faces, through which air enters tower, are on east and west sides. Louvers have been installed. Support framework for one of two venturi-shaped fan stacks (or "vents") is in center top. Orifices in hot basins (not in view) will distribute water over fill. Photographer: Kirsh. Date: May 15, 1969. INEEL negative no. 69-3032 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Miniature DMFCs with passive thermal-fluids management system

NASA Astrophysics Data System (ADS)

Guo, Zhen; Faghri, Amir

A new miniature DMFC system that includes a fuel cell stack, a fuel tank and a passive ancillary system (termed "thermal-fluids management system" in this paper) is presented. The thermal-fluids management system utilizes passive approaches for fuel storage and delivery, air breathing, water management, CO 2 release and thermal management. With 5.1 g of neat methanol in the fuel cartridge, a prototype has successfully demonstrated 18 h of continuous operation with total power output of 1.56 Wh.

LOFT. Mobile test building (TAN624) is recycled from ANP program ...

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

LOFT. Mobile test building (TAN-624) is recycled from ANP program for placement before LOFT containment building door. It has not yet been connected to containment building. Note borated water tank at right of dome. Narrow, vertical structure at right of door is shroud is shroud for air exhaust duct. Filter vaults lie between duct shroud and stack. Camera facing westerly. Date: 1974. INEEL negative no. 74-1072 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Partition/Ion-Exclusion Chromatographic Ion Stacking for the Analysis of Trace Anions in Water and Salt Samples by Ion Chromatography.

PubMed

Akter, Fouzia; Saito, Shingo; Tasaki-Handa, Yuiko; Shibukawa, Masami

2018-01-01

A new analytical methodology for a simple and efficient on-line preconcentration of trace inorganic anions in water and salt samples prior to ion chromatographic determination is proposed. The preconcentration method is based on partition/ion-exclusion chromatographic ion stacking (PIEC ion stacking) with a hydrophilic polymer gel column containing a small amount of fixed anionic charges. The developed on-line PIEC ion stacking-ion chromatography method was validated by recovery experiments for the determination of nitrate in tap water in terms of both accuracy and precision, and the results showed the reliability of the method. The method proposed was also successfully applied to the determination of trace impurity nitrite and nitrate in reagent-grade salts of sodium sulfate. A low background level can be achieved since pure water is used as the eluant for the PIEC ion stacking. It is possible to reach sensitive detection at sub-μg L -1 levels by on-line PIEC ion stacking-ion chromatography.

Cell module and fuel conditioner

NASA Technical Reports Server (NTRS)

Hoover, D. Q., Jr.

1981-01-01

The results of the completed tests on Stack 561 and the on-going tests of 562 (23 cell stacks of the MK-1 and M-2 designs respectively) are reported and their performance is compared. Results of the on-going endurance test of Stack 560 (5 cell, MK-2) are reported. Plans for fabrication of Stacks 563 and 564 (23 cell stacks of the MK-1 and MK-2 design) are summarized. Results of the burner tests are given. Excellent performance was achieved on simulated anode exhaust gas over very wide load and air/fuel ranges.

Generator module architecture for a large solid oxide fuel cell power plant

DOEpatents

Gillett, James E.; Zafred, Paolo R.; Riggle, Matthew W.; Litzinger, Kevin P.

2013-06-11

A solid oxide fuel cell module contains a plurality of integral bundle assemblies, the module containing a top portion with an inlet fuel plenum and a bottom portion receiving air inlet feed and containing a base support, the base supports dense, ceramic exhaust manifolds which are below and connect to air feed tubes located in a recuperator zone, the air feed tubes passing into the center of inverted, tubular, elongated, hollow electrically connected solid oxide fuel cells having an open end above a combustion zone into which the air feed tubes pass and a closed end near the inlet fuel plenum, where the fuel cells comprise a fuel cell stack bundle all surrounded within an outer module enclosure having top power leads to provide electrical output from the stack bundle, where the fuel cells operate in the fuel cell mode and where the base support and bottom ceramic air exhaust manifolds carry from 85% to all 100% of the weight of the stack, and each bundle assembly has its own control for vertical and horizontal thermal expansion control.

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

Estimates of ground level TSP, SO sub 2 and HCI for a municipal waste incinerator to be located at Tynes Bay - Bermuda

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

Kent Simmons, J.A.; Knap, A.H.

1991-04-01

The computer model Industrial Source Complex Short Term (ISCST) was used to study the stack emissions from a refuse incinerator proposed for the inland of Bermuda. The model predicts that the highest ground level pollutant concentrations will occur near Prospect, 800 m to 1,000 m due south of the stack. The authors installed a portable laboratory and instruments at Prospect to begin making air quality baseline measurements. By comparing the model's estimates of the incinerator contribution to the background levels measured at the site they predicted that stack emissions would not cause an increase in TSP or SO{sub 2}. Themore » incinerator will be a significant source of HCI to Bermuda air with ambient levels approaching air quality guidelines.« less

Structure of ice crystallized from supercooled water

PubMed Central

Malkin, Tamsin L.; Murray, Benjamin J.; Brukhno, Andrey V.; Anwar, Jamshed; Salzmann, Christoph G.

2012-01-01

The freezing of water to ice is fundamentally important to fields as diverse as cloud formation to cryopreservation. At ambient conditions, ice is considered to exist in two crystalline forms: stable hexagonal ice and metastable cubic ice. Using X-ray diffraction data and Monte Carlo simulations, we show that ice that crystallizes homogeneously from supercooled water is neither of these phases. The resulting ice is disordered in one dimension and therefore possesses neither cubic nor hexagonal symmetry and is instead composed of randomly stacked layers of cubic and hexagonal sequences. We refer to this ice as stacking-disordered ice I. Stacking disorder and stacking faults have been reported earlier for metastable ice I, but only for ice crystallizing in mesopores and in samples recrystallized from high-pressure ice phases rather than in water droplets. Review of the literature reveals that almost all ice that has been identified as cubic ice in previous diffraction studies and generated in a variety of ways was most likely stacking-disordered ice I with varying degrees of stacking disorder. These findings highlight the need to reevaluate the physical and thermodynamic properties of this metastable ice as a function of the nature and extent of stacking disorder using well-characterized samples. PMID:22232652

Structure of ice crystallized from supercooled water.

PubMed

Malkin, Tamsin L; Murray, Benjamin J; Brukhno, Andrey V; Anwar, Jamshed; Salzmann, Christoph G

2012-01-24

The freezing of water to ice is fundamentally important to fields as diverse as cloud formation to cryopreservation. At ambient conditions, ice is considered to exist in two crystalline forms: stable hexagonal ice and metastable cubic ice. Using X-ray diffraction data and Monte Carlo simulations, we show that ice that crystallizes homogeneously from supercooled water is neither of these phases. The resulting ice is disordered in one dimension and therefore possesses neither cubic nor hexagonal symmetry and is instead composed of randomly stacked layers of cubic and hexagonal sequences. We refer to this ice as stacking-disordered ice I. Stacking disorder and stacking faults have been reported earlier for metastable ice I, but only for ice crystallizing in mesopores and in samples recrystallized from high-pressure ice phases rather than in water droplets. Review of the literature reveals that almost all ice that has been identified as cubic ice in previous diffraction studies and generated in a variety of ways was most likely stacking-disordered ice I with varying degrees of stacking disorder. These findings highlight the need to reevaluate the physical and thermodynamic properties of this metastable ice as a function of the nature and extent of stacking disorder using well-characterized samples.

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.

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

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.

Stable and Selective Humidity Sensing Using Stacked Black Phosphorus Flakes.

PubMed

Yasaei, Poya; Behranginia, Amirhossein; Foroozan, Tara; Asadi, Mohammad; Kim, Kibum; Khalili-Araghi, Fatemeh; Salehi-Khojin, Amin

2015-10-27

Black phosphorus (BP) atomic layers are known to undergo chemical degradation in humid air. Yet in more robust configurations such as films, composites, and embedded structures, BP can potentially be utilized in a large number of practical applications. In this study, we explored the sensing characteristics of BP films and observed an ultrasensitive and selective response toward humid air with a trace-level detection capability and a very minor drift over time. Our experiments show that the drain current of the BP sensor increases by ∼4 orders of magnitude as the relative humidity (RH) varies from 10% to 85%, which ranks it among the highest ever reported values for humidity detection. The mechanistic studies indicate that the operation principle of the BP film sensors is based on the modulation in the leakage ionic current caused by autoionization of water molecules and ionic solvation of the phosphorus oxoacids produced on moist BP surfaces. Our stability tests reveal that the response of the BP film sensors remains nearly unchanged after prolonged exposures (up to 3 months) to ambient conditions. This study opens up the route for utilizing BP stacked films in many potential applications such as energy generation/storage systems, electrocatalysis, and chemical/biosensing.

Analysis of activated air following high yield shots in the NIF

DOE PAGES

Khater, Hesham; Brereton, Sandra

2015-07-24

During the ignition experimental campaign, the National Ignition Facility (NIF) is expected to perform shots with varying fusion yield (up to 20 MJ or 7.1 x 10 18 neutrons per shot) and a maximum annual yield of 1200 MJ. A detailed MCNP model of the Target Bay (TB) and the two switchyards (SY) has been developed to estimate the post-shot radiation environment inside the facility. During D-T shots, a pulse of 14.1 MeV neutrons streaming outside the Target Chamber (TC) will activate the air present inside the TB and the argon gas inside the laser tubes. Smaller levels of activitymore » are also generated in the SY air and in the argon portion of the SY laser beam path. The activated TB air will be mixed with fresh air from the Operations Support Building (OSB) before release through the stack. Flow of activated air from the Target Bay is controlled by the heating, ventilating, and air conditioning (HVAC) system. 16N (T 1/2 = 7.13 s) dominates the radiation levels during the first minute following the shot. It is expected that 16N will decay away during the confinement time before releasing the TB air through the stack. The other major contributors are 13N (T 1/2 = 9.97 min) and 41Ar (T 1/2 = 1.83 h). In general a low dose rate of < 1 μSv/h is expected near the stack during the first few hours following a 20 MJ shot. Here, the amount of activated Target Bay air released through the stack is very small and does not pose significant hazard to personnel or the environment. In the mean time, due to a very small leakage rate out of the laser tubes, the activated argon gas decays within the tubes and any resulting release to the environment is insignificant.« less

Analysis of activated air following high yield shots in the NIF

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

Khater, Hesham; Brereton, Sandra

During the ignition experimental campaign, the National Ignition Facility (NIF) is expected to perform shots with varying fusion yield (up to 20 MJ or 7.1 x 10 18 neutrons per shot) and a maximum annual yield of 1200 MJ. A detailed MCNP model of the Target Bay (TB) and the two switchyards (SY) has been developed to estimate the post-shot radiation environment inside the facility. During D-T shots, a pulse of 14.1 MeV neutrons streaming outside the Target Chamber (TC) will activate the air present inside the TB and the argon gas inside the laser tubes. Smaller levels of activitymore » are also generated in the SY air and in the argon portion of the SY laser beam path. The activated TB air will be mixed with fresh air from the Operations Support Building (OSB) before release through the stack. Flow of activated air from the Target Bay is controlled by the heating, ventilating, and air conditioning (HVAC) system. 16N (T 1/2 = 7.13 s) dominates the radiation levels during the first minute following the shot. It is expected that 16N will decay away during the confinement time before releasing the TB air through the stack. The other major contributors are 13N (T 1/2 = 9.97 min) and 41Ar (T 1/2 = 1.83 h). In general a low dose rate of < 1 μSv/h is expected near the stack during the first few hours following a 20 MJ shot. Here, the amount of activated Target Bay air released through the stack is very small and does not pose significant hazard to personnel or the environment. In the mean time, due to a very small leakage rate out of the laser tubes, the activated argon gas decays within the tubes and any resulting release to the environment is insignificant.« less

Vertical feed stick wood fuel burning furnace system

DOEpatents

Hill, Richard C.

1982-01-01

A stove or furnace for efficient combustion of wood fuel includes a vertical feed combustion chamber (15) for receiving and supporting wood fuel in a vertical attitude or stack. A major upper portion of the combustion chamber column comprises a water jacket (14) for coupling to a source of water or heat transfer fluid for convection circulation of the fluid. The locus (31) of wood fuel combustion is thereby confined to the refractory base of the combustion chamber. A flue gas propagation delay channel (34) extending laterally from the base of the chamber affords delayed travel time in a high temperature refractory environment sufficient to assure substantially complete combustion of the gaseous products of wood burning with forced air prior to extraction of heat in heat exchanger (16). Induced draft draws the fuel gas and air mixture laterally through the combustion chamber and refractory high temperature zone to the heat exchanger and flue. Also included are active sources of forced air and induced draft, multiple circuit couplings for the recovered heat, and construction features in the refractory material substructure and metal component superstructure.

The structure of ice crystallized from supercooled water

NASA Astrophysics Data System (ADS)

Murray, Benjamin

2013-03-01

The freezing of water to ice is fundamentally important to fields as diverse as cloud formation to cryopreservation. Traditionally ice was thought to exist in two well-crystalline forms: stable hexagonal ice and metastable cubic ice. It has recently been shown, using X-ray diffraction data, that ice which crystallizes homogeneously and heterogeneously from supercooled water is neither of these phases. The resulting ice is disordered in one dimension and therefore possesses neither cubic nor hexagonal symmetry and is instead composed of randomly stacked layers of cubic and hexagonal sequences. We refer to this ice as stacking-disordered ice I (ice Isd) . This result is consistent with a number of computational studies of the crystallization of water. Review of the literature reveals that almost all ice that has been identified as cubic ice in previous diffraction studies and generated in a variety of ways was most likely stacking-disordered ice I with varying degrees of stacking disorder, which raises the question of whether cubic ice exists. New data will be presented which shows significant stacking disorder (or stacking faults on the order of 1 in every 100 layers of ice Ih) in droplets which froze heterogeneously as warm as 257 K. The identification of stacking-disordered ice from heterogeneous ice nucleation supports the hypothesis that the structure of ice that initially crystallises from supercooled water is stacking-disordered ice I, independent of nucleation mechanism, but this ice can relax to the stable hexagonal phase subject to the kinetics of recrystallization. The formation and persistence of stacking disordered ice in the Earth's atmosphere will also be discussed. Funded by the European Research Council (FP7, 240449 ICE)

Pneumothorax as a complication of lung volume recruitment.

PubMed

Westermann, Erik J A; Jans, Maurice; Gaytant, Michael A; Bach, John R; Kampelmacher, Mike J

2013-01-01

Lung volume recruitment involves deep inflation techniques to achieve maximum insufflation capacity in patients with respiratory muscle weakness, in order to increase peak cough flow, thus helping to maintain airway patency and improve ventilation. One of these techniques is air stacking, in which a manual resuscitator is used in order to inflate the lungs. Although intrathoracic pressures can rise considerably, there have been no reports of respiratory complications due to air stacking. However, reaching maximum insufflation capacity is not recommended in patients with known structural abnormalities of the lungs or chronic obstructive airway disease. We report the case of a 72-year-old woman who had poliomyelitis as a child, developed torsion scoliosis and post-polio syndrome, and had periodic but infrequent asthma attacks. After performing air stacking for 3 years, the patient suddenly developed a pneumothorax, indicating that this technique should be used with caution or not at all in patients with a known pulmonary pathology.

Fuel-Cell Water Separator

NASA Technical Reports Server (NTRS)

Burke, Kenneth Alan; Fisher, Caleb; Newman, Paul

2010-01-01

The main product of a typical fuel cell is water, and many fuel-cell configurations use the flow of excess gases (i.e., gases not consumed by the reaction) to drive the resultant water out of the cell. This two-phase mixture then exits through an exhaust port where the two fluids must again be separated to prevent the fuel cell from flooding and to facilitate the reutilization of both fluids. The Glenn Research Center (GRC) has designed, built, and tested an innovative fuel-cell water separator that not only removes liquid water from a fuel cell s exhaust ports, but does so with no moving parts or other power-consuming components. Instead it employs the potential and kinetic energies already present in the moving exhaust flow. In addition, the geometry of the separator is explicitly intended to be integrated into a fuel-cell stack, providing a direct mate with the fuel cell s existing flow ports. The separator is also fully scalable, allowing it to accommodate a wide range of water removal requirements. Multiple separators can simply be "stacked" in series or parallel to adapt to the water production/removal rate. GRC s separator accomplishes the task of water removal by coupling a high aspect- ratio flow chamber with a highly hydrophilic, polyethersulfone membrane. The hydrophilic membrane readily absorbs and transports the liquid water away from the mixture while simultaneously resisting gas penetration. The expansive flow path maximizes the interaction of the water particles with the membrane while minimizing the overall gas flow restriction. In essence, each fluid takes its corresponding path of least resistance, and the two fluids are effectively separated. The GRC fuel-cell water separator has a broad range of applications, including commercial hydrogen-air fuel cells currently being considered for power generation in automobiles.

Wind Tunnel Model Study of the Hot Exhaust Plume from the Compressor Research Facility at Wright-Patterson Air Force Base, Ohio

DTIC Science & Technology

1977-10-01

PLUME FROM THE COMPRESSOR JtESEARCHJAC ILITY AT WRIGHT- /ATTERSON AIR FORCE JBASE, OHIO , r= mrm (.) Gary R./Ludwig 9. PERFORMING ORGANIZATION NAME... ms Mass flux of stack exhaust gas (slugs/sec) nrtfl Mass flux of ambient air and stack exhaust gas mixture st plume cross-section A (slugs/sec...the horizontal momentum flux in the ambient wind be the same in the model as it is in full-scale. /»» Ms M i a. ’ ro P>"S P*» + ’f (3) where 0

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.

Trace elements by instrumental neutron activation analysis for pollution monitoring

NASA Technical Reports Server (NTRS)

Sheibley, D. W.

1975-01-01

Methods and technology were developed to analyze 1000 samples/yr of coal and other pollution-related samples. The complete trace element analysis of 20-24 samples/wk averaged 3-3.5 man-hours/sample. The computerized data reduction scheme could identify and report data on as many as 56 elements. In addition to coal, samples of fly ash, bottom ash, crude oil, fuel oil, residual oil, gasoline, jet fuel, kerosene, filtered air particulates, ore, stack scrubber water, clam tissue, crab shells, river sediment and water, and corn were analyzed. Precision of the method was plus or minus 25% based on all elements reported in coal and other sample matrices. Overall accuracy was estimated at 50%.

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

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

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.

Air conditioning system

DOEpatents

Lowenstein, Andrew; Miller, Jeffrey; Gruendeman, Peter; DaSilva, Michael

2005-02-01

An air conditioner comprises a plurality of plates arranged in a successively stacked configuration with portions thereof having a spaced apart arrangement, and defining between successive adjacent pairs of plates at the spaced apart portions a first and second series of discrete alternating passages wherein a first air stream is passed through the first series of passages and a second air stream is passed through the second series of passages; and said stacked configuration of plates forming integrally therewith a liquid delivery means for delivering from a source a sufficient quantity of a liquid to the inside surfaces of the first series of fluid passages in a manner which provides a continuous flow of the liquid from a first end to a second end of the plurality of plates while in contact with the first air stream.

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.

Enhancement of thermal stability and water resistance in yttrium-doped GeO{sub 2}/Ge gate stack

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

Lu, Cimang, E-mail: cimang@adam.t.u-tokyo.ac.jp; Hyun Lee, Choong; Zhang, Wenfeng

2014-03-03

We have systematically investigated the material and electrical properties of yttrium-doped GeO{sub 2} (Y-GeO{sub 2}) on Germanium (Ge). A significant improvement of both thermal stability and water resistance were demonstrated by Y-GeO{sub 2}/Ge stack, compared to that of pure GeO{sub 2}/Ge stack. The excellent electrical properties of Y-GeO{sub 2}/Ge stacks with low D{sub it} were presented as well as enhancement of dielectric constant in Y-GeO{sub 2} layer, which is beneficial for further equivalent oxide thickness scaling of Ge gate stack. The improvement of thermal stability and water resistance are discussed both in terms of the Gibbs free energy lowering andmore » network modification of Y-GeO{sub 2}.« less

Void-Free Lid for Food Packaging

NASA Technical Reports Server (NTRS)

Watson, C. D.; Farris, W. P.

1986-01-01

Flexible cover eliminates air pockets in sealed container. Universal food-package lid formed from flexible plastic. Partially folded, lid unfolded by depressing center portion. Height of flat portion of lid above flange thereby reduced. Pressure of food against central oval depression pops it out, forming dome that provides finger grip for mixing contents with water or opening lid. Therefore food stays fresh, allows compact stacking of partially filled containers, and resists crushing. Originally developed for packaging dehydrated food for use in human consumption on Space Shuttle missions. Other uses include home canning and commercial food packaging.

L'Anse Warden Electric Company Boiler Number One Emission Test Report – March 2017

EPA Pesticide Factsheets

L’Anse Warden Electric Company (LWEC) submitted results from an emission test on the Boiler No. 1 stack. Stack air emission testing was conducted in March 2017, and the report became available in June 2017

L'Anse Warden Electric Company Boiler Number One Emission Test Report – December 2016

EPA Pesticide Factsheets

L’Anse Warden Electric Company (LWEC) submitted results from an emission test on the Boiler No. 1 stack. Stack air emission testing was conducted in December 2016, and the report became available in January 2017

L'Anse Warden Electric Company Boiler Number One Emission Test Report – July 2016

EPA Pesticide Factsheets

L’Anse Warden Electric Company (LWEC) submitted results from an emission test on the Boiler No. 1 stack. Stack air emission testing was conducted in July 2016, and the report became available in August 2016.

L'Anse Warden Electric Company Boiler Number One Emission Test Report – June 2017

EPA Pesticide Factsheets

L’Anse Warden Electric Company (LWEC) submitted results from an emission test on the Boiler No. 1 stack. Stack air emission testing was conducted in March 2017, and the report became available in June 2017

40 CFR 63.7320 - By what date must I conduct performance tests or other initial compliance demonstrations?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery Stacks Initial Compliance... coke oven battery stack by the compliance date that is specified in § 63.7283. (c) For each work...

40 CFR 63.7320 - By what date must I conduct performance tests or other initial compliance demonstrations?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery Stacks Initial Compliance... coke oven battery stack by the compliance date that is specified in § 63.7283. (c) For each work...

40 CFR 63.7320 - By what date must I conduct performance tests or other initial compliance demonstrations?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery Stacks Initial Compliance... coke oven battery stack by the compliance date that is specified in § 63.7283. (c) For each work...

40 CFR 63.7320 - By what date must I conduct performance tests or other initial compliance demonstrations?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery Stacks Initial Compliance... coke oven battery stack by the compliance date that is specified in § 63.7283. (c) For each work...

40 CFR 52.1169 - Stack height review.

Code of Federal Regulations, 2010 CFR

2010-07-01

....1169 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... limitations have been affected by stack height credits greater than good engineering practice or any other... under the Massachusetts SIP and our delegated PSD authority, the Department of Environmental Quality...

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...

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%.

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.

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% and second, that of a CP square patch fed from the ground plane side by a surface launch connector is 1.87%. Third, the impedance bandwidth of a CP stacked square patch fed by a surface launch connector is 2.22%. 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 center frequency, brought about by the reconfiguring of the physical layer antenna, can be exploited in a cognitive system since it expands the usable frequency spectrum for software reconfiguration in the presence of interference. In addition, varying the fixed air gap in the stacked antenna geometry by increments of 0.254 mm further expands the usable frequency spectrum.

3. View, piping and stack associated with the oxidizer vault ...

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

3. View, piping and stack associated with the oxidizer vault storage area in foreground with Systems Integration Laboratory (T-28) in background, looking northwest. - Air Force Plant PJKS, Systems Integration Laboratory, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

Dampers for Natural Draft Heaters: Technical Report

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

Lutz, James D.; Biermayer, Peter; King, Derek

2008-10-27

Energy required for water heating accounts for approximately 40percent of national residential natural gas consumption in California. With water heating contributing such a substantial portion of natural gas consumption, it is important to pay attention to water heater efficiencies. This paper reports on an investigation of a patented, buoyancy-operated flue damper. It is an add-on design to a standard atmospherically vented natural-draft gas-fired storage water heater. The flue damper was expected to reduce off-cycle standby losses, which would lead to improvements in the efficiency of the water heater. The test results showed that the Energy Factor of the baseline watermore » heater was 0.576. The recovery efficiency was 0.768. The standby heat loss coefficient was 10.619 (BTU/hr-oF). After the damper was installed, the test results show an Energy Factor for the baseline water heater of 0.605. The recovery efficiency was 0.786. The standby heat loss coefficient was 9.135 (BTU/hr-oF). The recovery efficiency increased 2.3percent and the standby heat loss coefficient decreased 14percent. When the burner was on, the baseline water heater caused 28.0 CFM of air to flow from the room. During standby, the flow was 12.4 CFM. The addition of the damper reduced the flow when the burner was on to 23.5 CFM. During standby, flow with the damper was reduced to 11.1 CFM. The flue damper reduced off-cycle standby losses, and improved the efficiency of the water heater. The flue damper also improved the recovery efficiency of the water heater by restricting on-cycle air flows through the flue.With or without the flue damper, off-cycle air flow upthe stack is nearly half the air flow rate as when the burner is firing.« less

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.

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

Fuel Cells Utilizing Oxygen From Air at Low Pressures

NASA Technical Reports Server (NTRS)

Cisar, Alan; Boyer, Chris; Greenwald, Charles

2006-01-01

A fuel cell stack has been developed to supply power for a high-altitude aircraft with a minimum of air handling. The fuel cell is capable of utilizing oxygen from ambient air at low pressure with no need for compression. For such an application, it is advantageous to take oxygen from the air (in contradistinction to carrying a supply of oxygen onboard), but it is a challenging problem to design a fuel-cell stack of reasonable weight that can generate sufficient power while operating at reduced pressures. The present fuel-cell design is a response to this challenge. The design features a novel bipolar plate structure in combination with a gas-diffusion structure based on a conductive metal core and a carbon gas-diffusion matrix. This combination makes it possible for the flow fields in the stack to have a large open fraction (ratio between open volume and total volume) to permit large volumes of air to flow through with exceptionally low backpressure. Operations at reduced pressure require a corresponding increase in the volume of air that must be handled to deliver the same number of moles of oxygen to the anodes. Moreover, the increase in the open fraction, relative to that of a comparable prior fuel-cell design, reduces the mass of the stack. The fuel cell has been demonstrated to operate at a power density as high as 105 W/cm2 at an air pressure as low as 2 psia (absolute pressure 14 kPa), which is the atmospheric pressure at an altitude of about 50,000 ft ( 15.2 km). The improvements in the design of this fuel cell could be incorporated into designs of other fuel cells to make them lighter in weight and effective at altitudes higher than those of prior designs. Potential commercial applications for these improvements include most applications now under consideration for fuel cells.

Natural gas availability and ambient air quality in the Baton Rouge/New Orleans industrial complex

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

Fieler, E.R.; Harrison, D.P.

1978-02-26

Three scenarios were modeled for the Baton Rouge/New Orleans area for 1985: one assumes the substitution of residual oil (0.7% sulfur) for gas to decrease gas-burning stationary sources from 80 to 8% and the use of properly designed stacks for large emitters; the second makes identical gas supply assumptions but adds proper stack dispersion for medium as well as large emitters; and the third is based on 16% gas-burning stationary sources. The Climatological Dispersion Model was used to translate (1974) emission rates into ambient air concentrations. Growth rates for residential, commercial, and transportation sources, but not industry, were considered. Themore » results show that proper policies, which would require not only tall stacks for large oil burning units (and for intermediate units also in the areas of high industrial concentration), but also the careful location of new plants would permit continued industrial expansion without severe air pollution problems.« less

40 CFR 61.53 - 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. 61.53 Section 61.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... sampling. (a) Mercury ore processing facility. (1) Unless a waiver of emission testing is obtained under...

40 CFR 61.53 - 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. 61.53 Section 61.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... sampling. (a) Mercury ore processing facility. (1) Unless a waiver of emission testing is obtained under...

40 CFR 52.2534 - Stack height review.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Stack height review. 52.2534 Section 52.2534 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... greater than good engineering practice or any other prohibited dispersion technique as defined in EPA's...

Rise Time Reduction of Thermal Actuators Operated in Air and Water through Optimized Pre-Shaped Open-Loop Driving.

PubMed

Larsen, T; Doll, J C; Loizeau, F; Hosseini, N; Peng, A W; Fantner, G; Ricci, A J; Pruitt, B L

2017-01-01

Electrothermal actuators have many advantages compared to other actuators used in Micro-Electro-Mechanical Systems (MEMS). They are simple to design, easy to fabricate and provide large displacements at low voltages. Low voltages enable less stringent passivation requirements for operation in liquid. Despite these advantages, thermal actuation is typically limited to a few kHz bandwidth when using step inputs due to its intrinsic thermal time constant. However, the use of pre-shaped input signals offers a route for reducing the rise time of these actuators by orders of magnitude. We started with an electrothermally actuated cantilever having an initial 10-90% rise time of 85 μs in air and 234 μs in water for a standard open-loop step input. We experimentally characterized the linearity and frequency response of the cantilever when operated in air and water, allowing us to obtain transfer functions for the two cases. We used these transfer functions, along with functions describing desired reduced rise-time system responses, to numerically simulate the required input signals. Using these pre-shaped input signals, we improved the open-loop 10-90% rise time from 85 μs to 3 μs in air and from 234 μs to 5 μs in water, an improvement by a factor of 28 and 47, respectively. Using this simple control strategy for MEMS electrothermal actuators makes them an attractive alternative to other high speed micromechanical actuators such as piezoelectric stacks or electrostatic comb structures which are more complex to design, fabricate, or operate.

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.

Control Techtronics International

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

West, J.

1995-12-31

Polish graded coal can be burned in existing stoker boilers and meet the 1998 Air Quality standard. This is accomplished with the Control Techtronics microprocessor-based combustion controller accurately and repeatedly: (a) matching the combustion air to the coal firing rate, with continuous stack sensor feedback; (b) continuously varying the boiler`s firing rate based on output water temperature or steam pressure; (c) continuously varying the exhaust fan`s speed to maintain minimum negative pressure in the boiler`s combustion chamber; and recirculating a portion of the flue gas, at varying amounts throughout the boiler`s firing rate. Systems for five boilers have been installedmore » and are operating on MPEC`s Balicka plant in Krakow. Control Techtronics International has $10 million of U.S. Export-Import Bank funds available for similar projects throughout Poland.« less

Converting environmental wastes into valuable resources

NASA Technical Reports Server (NTRS)

Duval, Leonard A.

1993-01-01

This concept employs a viable energy saving method that uses a solvent to separate oil from particle matter; it can be used in metal forming industries to deoil sludges, oxides, and particle matter that is presently committed to landfill. If oily particles are used in their oily state, severe consequences to environmental control systems such as explosions or filter blinding, occur in the air handling equipment. This is due to the presence of hydrocarbons in the stack gasses resulting from the oily particles. After deoiling, the particles can be recycled and the separated oil can be used as a fuel. The process does not produce a waste of it's own and does not harm air or water. It demonstrates the dual benefits of it being commercially viable and in the national interest of conserving resources.

Converting environmental wastes into valuable resources

NASA Astrophysics Data System (ADS)

Duval, Leonard A.

1993-02-01

This concept employs a viable energy saving method that uses a solvent to separate oil from particle matter; it can be used in metal forming industries to deoil sludges, oxides, and particle matter that is presently committed to landfill. If oily particles are used in their oily state, severe consequences to environmental control systems such as explosions or filter blinding, occur in the air handling equipment. This is due to the presence of hydrocarbons in the stack gasses resulting from the oily particles. After deoiling, the particles can be recycled and the separated oil can be used as a fuel. The process does not produce a waste of it's own and does not harm air or water. It demonstrates the dual benefits of it being commercially viable and in the national interest of conserving resources.

Lightweight Stacks of Direct Methanol Fuel Cells

NASA Technical Reports Server (NTRS)

Narayanan, Sekharipuram; Valdez, Thomas

2004-01-01

An improved design concept for direct methanol fuel cells makes it possible to construct fuel-cell stacks that can weigh as little as one-third as much as do conventional bipolar fuel-cell stacks of equal power. The structural-support components of the improved cells and stacks can be made of relatively inexpensive plastics. Moreover, in comparison with conventional bipolar fuel-cell stacks, the improved fuel-cell stacks can be assembled, disassembled, and diagnosed for malfunctions more easily. These improvements are expected to bring portable direct methanol fuel cells and stacks closer to commercialization. In a conventional bipolar fuel-cell stack, the cells are interspersed with bipolar plates (also called biplates), which are structural components that serve to interconnect the cells and distribute the reactants (methanol and air). The cells and biplates are sandwiched between metal end plates. Usually, the stack is held together under pressure by tie rods that clamp the end plates. The bipolar stack configuration offers the advantage of very low internal electrical resistance. However, when the power output of a stack is only a few watts, the very low internal resistance of a bipolar stack is not absolutely necessary for keeping the internal power loss acceptably low.

NPDES Permit for Cheyenne Mountain Air Force Station in Colorado

EPA Pesticide Factsheets

Under NPDES permit CO-0034762, the Cheyenne Mountain Air Force Station is authorized to discharge from the interior storm drainage system and air exhaust stacks at the Cheyenne Mountain Complex in El Paso County, Colorado, to tributaries Fountain Creek.

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...

40 CFR 63.9882 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2010 CFR

2010-07-01

... CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Primary Magnesium... affected sources are each new and existing primary magnesium refining facility. (b) This subpart covers emissions from each spray dryer stack, magnesium chloride storage bins scrubber stack, melt/reactor system...

40 CFR 63.9882 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2012 CFR

2012-07-01

... CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Primary Magnesium... affected sources are each new and existing primary magnesium refining facility. (b) This subpart covers emissions from each spray dryer stack, magnesium chloride storage bins scrubber stack, melt/reactor system...

40 CFR 63.9882 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2014 CFR

2014-07-01

... CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Primary Magnesium... affected sources are each new and existing primary magnesium refining facility. (b) This subpart covers emissions from each spray dryer stack, magnesium chloride storage bins scrubber stack, melt/reactor system...

40 CFR 63.9882 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2011 CFR

2011-07-01

... CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Primary Magnesium... affected sources are each new and existing primary magnesium refining facility. (b) This subpart covers emissions from each spray dryer stack, magnesium chloride storage bins scrubber stack, melt/reactor system...

40 CFR 63.9882 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2013 CFR

2013-07-01

... CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Primary Magnesium... affected sources are each new and existing primary magnesium refining facility. (b) This subpart covers emissions from each spray dryer stack, magnesium chloride storage bins scrubber stack, melt/reactor system...

40 CFR 52.1532 - Stack height review.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New Hampshire § 52.1532 Stack height review. The State of New Hampshire has declared to the satisfaction of EPA that no existing emission... the New Hampshire SIP and our delegated PSD authority, the New Hampshire Air Resources Agency will...

40 CFR 52.1532 - Stack height review.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New Hampshire § 52.1532 Stack height review. The State of New Hampshire has declared to the satisfaction of EPA that no existing emission... the New Hampshire SIP and our delegated PSD authority, the New Hampshire Air Resources Agency will...

40 CFR 52.1532 - Stack height review.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New Hampshire § 52.1532 Stack height review. The State of New Hampshire has declared to the satisfaction of EPA that no existing emission... the New Hampshire SIP and our delegated PSD authority, the New Hampshire Air Resources Agency will...

40 CFR 52.1532 - Stack height review.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New Hampshire § 52.1532 Stack height review. The State of New Hampshire has declared to the satisfaction of EPA that no existing emission... the New Hampshire SIP and our delegated PSD authority, the New Hampshire Air Resources Agency will...

40 CFR 52.1532 - Stack height review.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New Hampshire § 52.1532 Stack height review. The State of New Hampshire has declared to the satisfaction of EPA that no existing emission... the New Hampshire SIP and our delegated PSD authority, the New Hampshire Air Resources Agency will...

Post-experimental analysis of a solid oxide fuel cell stack using hybrid seals

NASA Astrophysics Data System (ADS)

Thomann, O.; Rautanen, M.; Himanen, O.; Tallgren, J.; Kiviaho, J.

2015-01-01

A post-experimental analysis of a SOFC stack is presented. The stack was operated for 1800 h at 700 °C with air and hydrogen and contained hybrid glass-Thermiculite 866 seals. The goal of this work was to investigate the sealing microstructure and possible corrosion during mid-term operation. It was found that hybrid seals could effectively compensate for manufacturing tolerances of cells and other components due to the compliance of the glass layer. Additionally, different interfaces were investigated for corrosion. Corrosion was not observed at two-phase interfaces such as Crofer 22 APU/glass, glass/electrolyte and glass/Thermiculite 866. The three-phase interface between Crofer 22 APU/glass/hydrogen exhibited no corrosion. Some evidence of non-systematic corrosion was found at the Crofer 22 APU/glass/air interface. The possible reasons for the corrosion are discussed. Lastly, dual exposure to humid hydrogen and air of the 0.2 mm Crofer 22 APU interconnect had no detrimental effect on the corrosion compared to air exposure. Overall the hybrid seals used in combination with the thin interconnects were found to be a promising solution due to the low leak rate and limited material interactions.

Flow Characteristics of a Multiple Nozzle Exhaust Gas Eductor System.

DTIC Science & Technology

1981-03-01

these exhaust gases are a temperatures significantly above those of conventionally powered ships. A few of the problems caused by these high temperatures ...systems designed for marine gas turbine applications must substantially cool exhaust gases , present an exterior stack surface temperature which will not...stack in. H 02 R - Gas constant for air, 53.34 ft-lbf/Ibm-R s - Entropy, Btu/Ibm-R S - Primary dimension of mixing stack T - Absolute temperature , R

Fuel cell arrangement

DOEpatents

Isenberg, A.O.

1987-05-12

A fuel cell arrangement is provided wherein cylindrical cells of the solid oxide electrolyte type are arranged in planar arrays where the cells within a plane are parallel. Planes of cells are stacked with cells of adjacent planes perpendicular to one another. Air is provided to the interior of the cells through feed tubes which pass through a preheat chamber. Fuel is provided to the fuel cells through a channel in the center of the cell stack; the fuel then passes the exterior of the cells and combines with the oxygen-depleted air in the preheat chamber. 3 figs.

Fuel cell arrangement

DOEpatents

Isenberg, Arnold O.

1987-05-12

A fuel cell arrangement is provided wherein cylindrical cells of the solid oxide electrolyte type are arranged in planar arrays where the cells within a plane are parallel. Planes of cells are stacked with cells of adjacent planes perpendicular to one another. Air is provided to the interior of the cells through feed tubes which pass through a preheat chamber. Fuel is provided to the fuel cells through a channel in the center of the cell stack; the fuel then passes the exterior of the cells and combines with the oxygen-depleted air in the preheat chamber.

Emissions of polycyclic aromatic hydrocarbons from batch hot mix asphalt plants.

PubMed

Lee, Wen-Jhy; Chao, Wen-Hui; Shih, Minliang; Tsai, Cheng-Hsien; Chen, Thomas Jeng-Ho; Tsai, Perng-Jy

2004-10-15

This study was set out to assess the characteristics of polycyclic aromatic hydrocarbon (PAH) emissions from batch hot mix asphalt (HMA) plants and PAH removal efficiencies associated with their installed air pollution control devices. Field samplings were conducted on six randomly selected batch HMA plants. For each selected plant, stack flue gas samples were collected from both stacks of the batch mixer (n = 5) and the preheating boiler (n = 5), respectively. PAH samples were also collected from the field to assess PAHs that were directly emitted from the discharging chute (n = 3). To assess PAH removal efficiencies of the installed air pollution control devices, PAH contents in both cyclone fly ash (n=3) and bag filter fly ash (n = 3) were analyzed. Results show that the total PAH concentration (mean; RSD) in the stack flue gas of the batch mixer (354 microg/Nm3; 78.5%) was higher than that emitted from the discharging chute (107 microg/Nm3; 70.1%) and that in the stack flue gas of the preheating boiler (83.7 microg/Nm3; 77.6%). But the total BaPeq concentration of that emitted from the discharging chute (0.950 microg/Nm3; 84.4%) was higher than contained in the stack flue gas of the batch mixer (0.629 microg/Nm3; 86.8%) and the stack flue gas of the preheating boiler (= 0.112 microg/Nm3; 80.3%). The mean total PAH emission factor for all selected batch mix plants (= 139 mg/ton x product) was much higher than that reported by U.S. EPA for the drum mix asphalt plant (range = 11.8-79.0 mg/ton x product). We found the overall removal efficiency of the installed air pollution control devices (i.e., cyclone + bag filter) on total PAHs and total BaPeq were 22.1% and 93.7%, respectively. This implies that the installed air pollution control devices, although they have a very limited effect on the removal of total PAHs, do significantly reduce the carcinogenic potencies associated with PAH emissions from batch HMA plants.

Scattering by Spheroidal and Rough Particles.

DTIC Science & Technology

1982-12-01

expanded polystyrene beads(Sincl.air-Koppers DylJ.te F 40) in the weight proportion 0.025 to 1.0, and molding the homogeaeous mixture in cement molds...stacking 7 expanded polystyrene (Sinclair-Koppers Dylite F 40) cylinders. The second group(/030 series) is prepared by coating the similar stack by

40 CFR 60.1780 - How are the stack test data used?

Code of Federal Regulations, 2014 CFR

2014-07-01

... for carbon monoxide, nitrogen oxides, and sulfur dioxide, see § 60.1725. ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false How are the stack test data used? 60.1780 Section 60.1780 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 60.1780 - How are the stack test data used?

Code of Federal Regulations, 2012 CFR

2012-07-01

... for carbon monoxide, nitrogen oxides, and sulfur dioxide, see § 60.1725. ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false How are the stack test data used? 60.1780 Section 60.1780 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 60.1780 - How are the stack test data used?

Code of Federal Regulations, 2010 CFR

2010-07-01

... for carbon monoxide, nitrogen oxides, and sulfur dioxide, see § 60.1725. ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false How are the stack test data used? 60.1780 Section 60.1780 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 60.1780 - How are the stack test data used?

Code of Federal Regulations, 2011 CFR

2011-07-01

... for carbon monoxide, nitrogen oxides, and sulfur dioxide, see § 60.1725. ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false How are the stack test data used? 60.1780 Section 60.1780 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 60.1780 - How are the stack test data used?

Code of Federal Regulations, 2013 CFR

2013-07-01

... for carbon monoxide, nitrogen oxides, and sulfur dioxide, see § 60.1725. ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false How are the stack test data used? 60.1780 Section 60.1780 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

Cell module and fuel conditioner

NASA Technical Reports Server (NTRS)

Hoover, D. Q., Jr.

1980-01-01

The computer code for the detailed analytical model of the MK-2 stacks is described. An ERC proprietary matrix is incorporated in the stacks. The mechanical behavior of the stack during thermal cycles under compression was determined. A 5 cell stack of the MK-2 design was fabricated and tested. Designs for the next three stacks were selected and component fabrication initiated. A 3 cell stack which verified the use of wet assembly and a new acid fill procedure were fabricated and tested. Components for the 2 kW test facility were received or fabricated and construction of the facility is underway. The definition of fuel and water is used in a study of the fuel conditioning subsystem. Kinetic data on several catalysts, both crushed and pellets, was obtained in the differential reactor. A preliminary definition of the equipment requirements for treating tap and recovered water was developed.

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.

40 CFR Table 3 to Subpart Ttttt of... - Initial Compliance With Emission Limits

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Primary Magnesium... dryer stack a. The average mass flow of particulate matter from the control system applied to emissions...

Stacking Oxygen-Separation Cells

NASA Technical Reports Server (NTRS)

Schroeder, James E.

1991-01-01

Simplified configuration and procedure developed for assembly of stacks of solid-electrolyte cells separating oxygen from air electrochemically. Reduces number of components and thus reduces probability of such failures as gas leaks, breakdown of sensitive parts, and electrical open or short circuits. Previous, more complicated version of cell described in "Improved Zirconia Oxygen-Separation Cell" (NPO-16161).

40 CFR Table I-17 to Subpart I of... - Expected and Possible By-Products for Electronics Manufacturinglg

Code of Federal Regulations, 2014 CFR

2014-07-01

... Electronics Manufacturinglg I Table I-17 to Subpart I of Part 98 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Electronics... for Electronics Manufacturinglg For each stack system for which you use the “stack test method” to...

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.

Air-stable n-channel organic thin-film transistors with high field-effect mobility based on N ,N'-bis(heptafluorobutyl)-3,4:9,10-perylene diimide

NASA Astrophysics Data System (ADS)

Oh, Joon Hak; Liu, Shuhong; Bao, Zhenan; Schmidt, Rüdiger; Würthner, Frank

2007-11-01

The thin-film transistor characteristics of n-channel organic semiconductor, N ,N'-bis(2,2,3,3,4,4,4-heptafluorobutyl)-perylene tetracarboxylic diimide, are described. The slip-stacked face-to-face molecular packing allows a very dense parallel arrangement of the molecules, leading to field-effect mobility as high as 0.72cm2V-1s-1. The mobility only slightly decreased after exposure to air and remained stable for more than 50days. Our results reveal that molecular packing effects such as close stacking of perylene diimide units and segregation effects imparted by the fluorinated side chains are crucial for the air stability.

Simulation of existing gas-fuelled conventional steam power plant using Cycle Tempo

NASA Astrophysics Data System (ADS)

Jamel, M. S.; Abd Rahman, A.; Shamsuddin, A. H.

2013-06-01

Simulation of a 200 MW gas-fuelled conventional steam power plant located in Basra, Iraq was carried out. The thermodynamic performance of the considered power plant is estimated by a system simulation. A flow-sheet computer program, "Cycle-Tempo" is used for the study. The plant components and piping systems were considered and described in detail. The simulation results were verified against data gathered from the log sheet obtained from the station during its operation hours and good results were obtained. Operational factors like the stack exhaust temperature and excess air percentage were studied and discussed, as were environmental factors, such as ambient air temperature and water inlet temperature. In addition, detailed exergy losses were illustrated and describe the temperature profiles for the main plant components. The results prompted many suggestions for improvement of the plant performance.

Using Waste Heat for External Processes (English/Chinese) (Fact Sheet) (in Chin3se; English)

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

Not Available

Chinese translation of the Using Waste Heat for External Processes fact sheet. Provides suggestions on how to use waste heat in industrial applications. The temperature of exhaust gases from fuel-fired industrial processes depends mainly on the process temperature and the waste heat recovery method. Figure 1 shows the heat lost in exhaust gases at various exhaust gas temperatures and percentages of excess air. Energy from gases exhausted from higher temperature processes (primary processes) can be recovered and used for lower temperature processes (secondary processes). One example is to generate steam using waste heat boilers for the fluid heaters used inmore » petroleum crude processing. In addition, many companies install heat exchangers on the exhaust stacks of furnaces and ovens to produce hot water or to generate hot air for space heating.« less

The near-source impacts of diesel backup generators in urban environments

NASA Astrophysics Data System (ADS)

Tong, Zheming; Zhang, K. Max

2015-05-01

Distributed power generation, located close to consumers, plays an important role in the current and future power systems. However, its near-source impacts in complex urban environments are not well understood. In this paper, we focused on diesel backup generators that participate in demand response (DR) programs. We first improved the micro-environmental air quality simulations by employing a meteorology processor, AERMET, to generate site-specific boundary layer parameters for the Large Eddy Simulation (LES) modeling. The modeling structure was then incorporated into the CTAG model to evaluate the environmental impacts of diesel backup generators in near-source microenvironments. We found that the presence of either tall upwind or downwind building can deteriorate the air quality in the near-stack street canyons, largely due to the recirculation zones generated by the tall buildings, reducing the near-stack dispersion. Decreasing exhaust momentum ratio (stack exit velocity/ambient wind velocity) draws more exhaust into the recirculation zone, and reduces the effective stack height, which results in elevated near-ground concentrations inside downwind street canyons. The near-ground PM2.5 concentration for the worst scenarios could well exceed 100 μg m-3, posing potential health risk to people living and working nearby. In general, older diesel backup generators (i.e., Tier 1, 2 or older) without the up-to-date emission control may significantly increase the pollutant concentration in the near-source street canyons if participating in DR programs. Even generators that comply with Tier-4 standards could lead to PM hotspots if their stacks are next to tall buildings. Our study implies that the siting of diesel backup generators stacks should consider not only the interactions of fresh air intake and exhaust outlet for the building housing the backup generators, but also the dispersion of exhaust plumes in the surrounding environment.

Analysis of Percent On-Cell Reformation of Methane in SOFC Stacks and the Effects on Thermal, Electrical, and Mechanical Performance

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

Recknagle, Kurtis P.; Koeppel, Brian J.; Sun, Xin

2007-04-30

Numerical simulations were performed to determine the effect that varying the percent on-cell steam-methane reformation would have on the thermal, electrical, and mechanical performance of generic, planar solid oxide fuel cell stacks. The study was performed using three-dimensional model geometries for cross-, co-, and counter-flow configuration stacks of 10x10- and 20x20-cm cell sizes. The analysis predicted the stress and temperature difference would be minimized for the 10x10-cm counter- and cross-flow stacks when 40 to 50% of the reformation reaction occurred on the anode. Gross electrical power density was virtually unaffected by the reforming. The co-flow stack benefited most from themore » on-cell reforming and had the lowest anode stresses of the 20x20-cm stacks. The analyses also suggest that airflows associated with 15% air utilization may be required for cooling the larger (20x20-cm) stacks.« less

Simultaneous stack-gas scrubbing and waste water treatment

NASA Technical Reports Server (NTRS)

Poradek, J. C.; Collins, D. D.

1980-01-01

Simultaneous treatment of wastewater and S02-laden stack gas make both treatments more efficient and economical. According to results of preliminary tests, solution generated by stack gas scrubbing cycle reduces bacterial content of wastewater. Both processess benefit by sharing concentrations of iron.

Lighting system combining daylight concentrators and an artificial source

DOEpatents

Bornstein, Jonathan G.; Friedman, Peter S.

1985-01-01

A combined lighting system for a building interior includes a stack of luminescent solar concentrators (LSC), an optical conduit made of preferably optical fibers for transmitting daylight from the LSC stack, a collimating lens set at an angle, a fixture for receiving the daylight at one end and for distributing the daylight as illumination inside the building, an artificial light source at the other end of the fixture for directing artifical light into the fixture for distribution as illumination inside the building, an automatic dimmer/brightener for the artificial light source, and a daylight sensor positioned near to the LSC stack for controlling the automatic dimmer/brightener in response to the daylight sensed. The system also has a reflector positioned behind the artificial light source and a fan for exhausting heated air out of the fixture during summer and for forcing heated air into the fixture for passage into the building interior during winter.

KSC-2011-1457

NASA Image and Video Library

2011-02-15

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 576-E at Vandenberg Air Force Base in California, Orbital Sciences workers prepare NASA's Glory upper stack for attachment to the Taurus XL rocket's Stage 0. The upper stack consists of Stages 1, 2 and 3 of the Taurus as well as the encapsulated Glory spacecraft. Workers put the non-flight environmental shield over the fairing prior to assembly. A portion of the umbilical tower is attached to the upper stack which falls away from the spacecraft during liftoff. The Orbital Sciences Taurus XL rocket will launch Glory into low Earth orbit. Once Glory reaches orbit, it will collect data on the properties of aerosols and black carbon. It also will help scientists understand how the sun's irradiance affects Earth's climate. Launch is scheduled for 5:09 a.m. EST Feb. 23. For information, visit www.nasa.gov/glory. Photo credit: NASA/Randy Beaudoin, VAFB

40 CFR 61.202 - Standard.

Code of Federal Regulations, 2010 CFR

2010-07-01

... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standards for Radon Emissions From... the stack does not emit more than 20 pCi/(m2-sec) (1.9 pCi/(ft2-sec)) of radon-222 into the air. [57...

40 CFR 61.202 - Standard.

Code of Federal Regulations, 2011 CFR

2011-07-01

... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standards for Radon Emissions From... the stack does not emit more than 20 pCi/(m2-sec) (1.9 pCi/(ft2-sec)) of radon-222 into the air. [57...

40 CFR 60.1300 - What test methods must I use to stack test?

Code of Federal Regulations, 2010 CFR

2010-07-01

... to the Administrator for approval under § 60.8(b) to use a reference method with minor changes in... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What test methods must I use to stack test? 60.1300 Section 60.1300 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...

40 CFR 60.1790 - What test methods must I use to stack test?

Code of Federal Regulations, 2010 CFR

2010-07-01

... methods in table 6 of this subpart for other required equations. (e) You can apply to the Administrator... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What test methods must I use to stack test? 60.1790 Section 60.1790 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...

40 CFR 62.15245 - What test methods must I use to stack test?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 9 2014-07-01 2014-07-01 false What test methods must I use to stack test? 62.15245 Section 62.15245 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF STATE PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Federal Plan Requirements for Small...

40 CFR 60.1300 - What test methods must I use to stack test?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 6 2011-07-01 2011-07-01 false What test methods must I use to stack test? 60.1300 Section 60.1300 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Small Municipal Waste Combustion Units for...

40 CFR 60.1790 - What test methods must I use to stack test?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 6 2011-07-01 2011-07-01 false What test methods must I use to stack test? 60.1790 Section 60.1790 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Emission Guidelines and Compliance Times for Small Municipal Waste...

40 CFR 62.15245 - What test methods must I use to stack test?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 9 2013-07-01 2013-07-01 false What test methods must I use to stack test? 62.15245 Section 62.15245 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF STATE PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Federal Plan Requirements for Small...

40 CFR 62.15245 - What test methods must I use to stack test?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 9 2012-07-01 2012-07-01 false What test methods must I use to stack test? 62.15245 Section 62.15245 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF STATE PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Federal Plan Requirements for Small...

40 CFR 60.1790 - What test methods must I use to stack test?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 7 2012-07-01 2012-07-01 false What test methods must I use to stack test? 60.1790 Section 60.1790 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Emission Guidelines and Compliance Times for Small Municipal Waste...

40 CFR 60.1300 - What test methods must I use to stack test?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 7 2012-07-01 2012-07-01 false What test methods must I use to stack test? 60.1300 Section 60.1300 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Small Municipal Waste Combustion Units for...

40 CFR 60.1790 - What test methods must I use to stack test?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 7 2014-07-01 2014-07-01 false What test methods must I use to stack test? 60.1790 Section 60.1790 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Emission Guidelines and Compliance Times for Small Municipal Waste...

40 CFR 60.1300 - What test methods must I use to stack test?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 7 2014-07-01 2014-07-01 false What test methods must I use to stack test? 60.1300 Section 60.1300 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Small Municipal Waste Combustion Units for...

40 CFR 62.15245 - What test methods must I use to stack test?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 8 2011-07-01 2011-07-01 false What test methods must I use to stack test? 62.15245 Section 62.15245 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF STATE PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Federal Plan Requirements for Small...

40 CFR 60.1790 - What test methods must I use to stack test?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 7 2013-07-01 2013-07-01 false What test methods must I use to stack test? 60.1790 Section 60.1790 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Emission Guidelines and Compliance Times for Small Municipal Waste...

40 CFR 60.1300 - What test methods must I use to stack test?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 7 2013-07-01 2013-07-01 false What test methods must I use to stack test? 60.1300 Section 60.1300 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Small Municipal Waste Combustion Units for...

40 CFR Table 5 of Subpart Aaaa of... - Requirements for Stack Tests

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Requirements for Stack Tests 5 Table 5 of Subpart AAAA of Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Small Municipal Waste Combustion Units for...

40 CFR Table 5 of Subpart Aaaa of... - Requirements for Stack Tests

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Requirements for Stack Tests 5 Table 5 of Subpart AAAA of Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Small Municipal Waste Combustion Units for...

40 CFR Table I-9 to Subpart I of... - Methods and Procedures for Conducting Emissions Test for Stack Systems

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Methods and Procedures for Conducting Emissions Test for Stack Systems I Table I-9 to Subpart I of Part 98 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Electronics...

Air pollution and dry deposition of nitrogen and sulphur in the AOSR estimated using passive samplers

Treesearch

Yu-Mei Hsu; Andrzej Bytnerowicz

2015-01-01

NO2 and SO2 are the primary pollutants produced by industrial facilities of the Athabasca Oil sand Region (AOSR), Alberta, Canada. The major emission sources are the upgrader stacks for SO2 and stacks, mine fleets and vehicles for NO2. After emitting from the sources, NO

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.

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, arrive in the Building 1 airlock 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 Uncovering of Spacecraft

NASA Image and Video Library

2014-10-30

Technicians remove the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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, roll into the Building 1 airlock 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

Workers position two of the observatories, the lower stack, mini-stack number 1 for NASA's Magnetospheric Multiscale Observatory, or MMS, onto a payload dolly 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.

Proton Exchange Membrane (PEM) Fuel Cells for Space Applications

NASA Technical Reports Server (NTRS)

Bradley, Karla

2004-01-01

This presentation will provide a summary of the PEM fuel cell development at the National Aeronautics and Space Administration, Johnson Space Center (NASA, JSC) in support of future space applications. Fuel cells have been used for space power generation due to their high energy storage density for multi-day missions. The Shuttle currently utilizes the alkaline fuel cell technology, which has highly safe and reliable performance. However, the alkaline technology has a limited life due to the corrosion inherent to the alkaline technology. PEM fuel cells are under development by industry for transportation, residential and commercial stationary power applications. NASA is trying to incorporate some of this stack technology development in the PEM fuel cells for space. NASA has some unique design and performance parameters which make developing a PEM fuel cell system more challenging. Space fuel cell applications utilize oxygen, rather than air, which yields better performance but increases the hazard level. To reduce the quantity of reactants that need to be flown in space, NASA also utilizes water separation and reactant recirculation. Due to the hazards of utilizing active components for recirculation and water separation, NASA is trying to develop passive recirculation and water separation methods. However, the ability to develop recirculation components and water separators that are gravity-independent and successfully operate over the full range of power levels is one of the greatest challenges to developing a safe and reliable PEM fuel cell system. PEM stack, accessory component, and system tests that have been performed for space power applications will be discussed.

KSC-2015-1065

NASA Image and Video Library

2015-01-12

The protective covers are removed from around the solar panels on the upper stack of the Magnetospheric Multiscale spacecraft, or MMS, in the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. Preparations are underway for illumination testing of the spacecraft's upper stack. Illumination testing of the lower instrumentation payload stack was completed in December. 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. To learn more about MMS, visit http://www.nasa.gov/mms. Photo credit: NASA/Kim Shiflett

KSC-2015-1066

NASA Image and Video Library

2015-01-12

The protective covers are removed from around the solar panels on the upper stack of the Magnetospheric Multiscale spacecraft, or MMS, in the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. Preparations are underway for illumination testing of the spacecraft's upper stack. Illumination testing of the lower instrumentation payload stack was completed in December. 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. To learn more about MMS, visit http://www.nasa.gov/mms. Photo credit: NASA/Kim Shiflett

2. RICE THRESHING MILL WITH CHIMNEY STACK. Fire burned on ...

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

2. RICE THRESHING MILL WITH CHIMNEY STACK. Fire burned on top of water pipe at base of chimney stack and steam went thru pipes to boiler on south side of wall. - Mansfield Plantation, Rice Threshing Mill, U.S. Route 701 vicinity, Georgetown, Georgetown County, SC

40 CFR 60.4930 - What definitions must I know?

Code of Federal Regulations, 2011 CFR

2011-07-01

... stack means a device used for discharging combustion gases to avoid severe damage to the air pollution..., 2010. Fabric filter means an add-on air pollution control device used to capture particulate matter by... sludge prior to incineration). (2) A change in the air pollution control devices used to comply with the...

40 CFR 60.4930 - What definitions must I know?

Code of Federal Regulations, 2013 CFR

2013-07-01

... stack means a device used for discharging combustion gases to avoid severe damage to the air pollution..., 2010. Fabric filter means an add-on air pollution control device used to capture particulate matter by... sludge prior to incineration). (2) A change in the air pollution control devices used to comply with the...

40 CFR 60.4930 - What definitions must I know?

Code of Federal Regulations, 2012 CFR

2012-07-01

... stack means a device used for discharging combustion gases to avoid severe damage to the air pollution..., 2010. Fabric filter means an add-on air pollution control device used to capture particulate matter by... sludge prior to incineration). (2) A change in the air pollution control devices used to comply with the...

40 CFR 60.4930 - What definitions must I know?

Code of Federal Regulations, 2014 CFR

2014-07-01

... stack means a device used for discharging combustion gases to avoid severe damage to the air pollution..., 2010. Fabric filter means an add-on air pollution control device used to capture particulate matter by... sludge prior to incineration). (2) A change in the air pollution control devices used to comply with the...

Staged venting of fuel cell system during rapid shutdown

DOEpatents

Clingerman, Bruce J.; Doan, Tien M.; Keskula, Donald H.

2002-01-01

A venting methodology and system for rapid shutdown of a fuel cell apparatus of the type used in a vehicle propulsion system. H.sub.2 and air flows to the fuel cell stack are slowly bypassed to the combustor upon receipt of a rapid shutdown command. The bypass occurs over a period of time (for example one to five seconds) using conveniently-sized bypass valves. Upon receipt of the rapid shutdown command, the anode inlet of the fuel cell stack is instantaneously vented to a remote vent to remove all H.sub.2 from the stack. Airflow to the cathode inlet of the fuel cell stack gradually diminishes over the bypass period, and when the airflow bypass is complete the cathode inlet is also instantaneously vented to a remote vent to eliminate pressure differentials across the stack.

Staged venting of fuel cell system during rapid shutdown

DOEpatents

Keskula, Donald H.; Doan, Tien M.; Clingerman, Bruce J.

2004-09-14

A venting methodology and system for rapid shutdown of a fuel cell apparatus of the type used in a vehicle propulsion system. H.sub.2 and air flows to the fuel cell stack are slowly bypassed to the combustor upon receipt of a rapid shutdown command. The bypass occurs over a period of time (for example one to five seconds) using conveniently-sized bypass valves. Upon receipt of the rapid shutdown command, the anode inlet of the fuel cell stack is instantaneously vented to a remote vent to remove all H.sub.2 from the stack. Airflow to the cathode inlet of the fuel cell stack gradually diminishes over the bypass period, and when the airflow bypass is complete the cathode inlet is also instantaneously vented to a remote vent to eliminate pressure differentials across the stack.

Extent and relevance of stacking disorder in “ice Ic”

PubMed Central

Kuhs, Werner F.; Sippel, Christian; Falenty, Andrzej; Hansen, Thomas C.

2012-01-01

A solid water phase commonly known as “cubic ice” or “ice Ic” is frequently encountered in various transitions between the solid, liquid, and gaseous phases of the water substance. It may form, e.g., by water freezing or vapor deposition in the Earth’s atmosphere or in extraterrestrial environments, and plays a central role in various cryopreservation techniques; its formation is observed over a wide temperature range from about 120 K up to the melting point of ice. There was multiple and compelling evidence in the past that this phase is not truly cubic but composed of disordered cubic and hexagonal stacking sequences. The complexity of the stacking disorder, however, appears to have been largely overlooked in most of the literature. By analyzing neutron diffraction data with our stacking-disorder model, we show that correlations between next-nearest layers are clearly developed, leading to marked deviations from a simple random stacking in almost all investigated cases. We follow the evolution of the stacking disorder as a function of time and temperature at conditions relevant to atmospheric processes; a continuous transformation toward normal hexagonal ice is observed. We establish a quantitative link between the crystallite size established by diffraction and electron microscopic images of the material; the crystallite size evolves from several nanometers into the micrometer range with progressive annealing. The crystallites are isometric with markedly rough surfaces parallel to the stacking direction, which has implications for atmospheric sciences. PMID:23236184

Stacked waveguide reactors with gradient embedded scatterers for high-capacity water cleaning

DOE PAGES

Ahsan, Syed Saad; Gumus, Abdurrahman; Erickson, David

2015-11-04

We present a compact water-cleaning reactor with stacked layers of waveguides containing gradient patterns of optical scatterers that enable uniform light distribution and augmented water-cleaning rates. Previous photocatalytic reactors using immersion, external, or distributive lamps suffer from poor light distribution that impedes scalability. Here, we use an external UV-source to direct photons into stacked waveguide reactors where we scatter the photons uniformly over the length of the waveguide to thin films of TiO 2-catalysts. In conclusion, we also show 4.5 times improvement in activity over uniform scatterer designs, demonstrate a degradation of 67% of the organic dye, and characterize themore » degradation rate constant.« less

Stacked waveguide reactors with gradient embedded scatterers for high-capacity water cleaning

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

Ahsan, Syed Saad; Gumus, Abdurrahman; Erickson, David

We present a compact water-cleaning reactor with stacked layers of waveguides containing gradient patterns of optical scatterers that enable uniform light distribution and augmented water-cleaning rates. Previous photocatalytic reactors using immersion, external, or distributive lamps suffer from poor light distribution that impedes scalability. Here, we use an external UV-source to direct photons into stacked waveguide reactors where we scatter the photons uniformly over the length of the waveguide to thin films of TiO 2-catalysts. In conclusion, we also show 4.5 times improvement in activity over uniform scatterer designs, demonstrate a degradation of 67% of the organic dye, and characterize themore » degradation rate constant.« less

40 CFR Table 5 of Subpart Aaaa to... - Requirements for Stack Tests

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Requirements for Stack Tests 5 Table 5 of Subpart AAAA to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Pt. 60, Subpt. AAAA, Table 5 Table 5 of Subpart AAAA to Part 60—Requirement...

40 CFR Table 5 of Subpart Aaaa to... - Requirements for Stack Tests

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Requirements for Stack Tests 5 Table 5 of Subpart AAAA to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Pt. 60, Subpt. AAAA, Table 5 Table 5 of Subpart AAAA to Part 60—Requirement...

40 CFR Table 5 of Subpart Aaaa to... - Requirements for Stack Tests

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Requirements for Stack Tests 5 Table 5 of Subpart AAAA to Part 60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Pt. 60, Subpt. AAAA, Table 5 Table 5 of Subpart AAAA to Part 60—Requirement...

KSC-2009-1681

NASA Image and Video Library

2009-02-18

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, upper stack is prepared to be raised to vertical. The upper stack, consists of stages 1, 2 and 3 of the Taurus. The spacecraft is scheduled for launch aboard Orbital Sciences' Taurus XL rocket Feb. 24 from Vandenberg. The spacecraft will collect precise global measurements of carbon dioxide (CO2) in the Earth's atmosphere. Scientists will analyze OCO data to improve our understanding of the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Photo credit: NASA/Randy Beaudoin, VAFB

24 CFR 3280.406 - Air chamber test method for certification and qualification of formaldehyde emission levels.

Code of Federal Regulations, 2010 CFR

2010-04-01

... particleboard is produced or surface-finished, whichever is later, the panels must be dead-stacked or air-tight... with the Standard Test Method for Determining Formaldehyde Levels from Wood Products Under Defined Test...

Development of a High Reliability Compact Air Independent PEMFC Power System

NASA Technical Reports Server (NTRS)

Vasquez, Arturo; Wynne, Bob

2013-01-01

Autonomous Underwater Vehicles (AUV's) have received increasing attention in recent years as military and commercial users look for means to maintain a mobile and persistent presence in the undersea world. Compact, neutrally buoyant power systems are needed for both small and large vehicles. Historically, batteries have been employed in these applications, but the energy density and therefore mission duration are limited with current battery technologies. Vehicles with stored energy requirements greater than approximately 10 kWh have an alternate means to get long duration power. High efficiency Proton Exchange Membrane (PEM) fuel cell systems utilizing pure hydrogen and oxygen reactants show the potential for an order of magnitude energy density improvement over batteries as long as the subsystems are compact. One key aspect to achieving a compact and energy dense system is the design of the fuel cell balance of plant (BOP). Recent fuel cell work, initially focused on NASA applications requiring high reliability, has developed systems that can meet target power and energy densities. Passive flow through systems using ejector driven reactant (EDR) circulation have been developed to provide high reactant flow and water management within the stack, with minimal parasitic losses compared to blowers. The ejectors and recirculation loops, along with valves and other BOP instrumentation, have been incorporated within the stack end plate. In addition, components for water management and reactant conditioning have been incorporated within the stack to further minimize the BOP. These BOP systems are thermally and functionally integrated into the stack hardware and fit into the small volumes required for AUV and future NASA applications to maximize the volume available for reactants. These integrated systems provide a compact solution for the fuel cell BOP and maximize the efficiency and reliability of the system. Designs have been developed for multiple applications ranging from less than 1 kWe to 70 kWe. These systems occupy a very small portion of the overall energy system, allowing most of the system volume to be used for reactants. The fuel cell systems have been optimized to use reactants efficiently with high stack efficiency and low parasitic losses. The resulting compact, highly efficient fuel cell system provides exceptional reactant utilization and energy density. Key design variables and supporting test data are presented. Future development activities are described.

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

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.

MMS Uncovering of Spacecraft

NASA Image and Video Library

2014-10-30

A technician carefully removes the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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 Uncovering of Spacecraft

NASA Image and Video Library

2014-10-30

Technicians begin to remove the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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 for NASA's Magnetospheric Multiscale Observatory, or MMS, the lower stack, mini-stack number 1, begin the trip from the Building 2 south encapsulation bay to the Building 1 high 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 Uncovering of Spacecraft

NASA Image and Video Library

2014-10-30

Technicians prepare to remove the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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 Uncovering of Spacecraft

NASA Image and Video Library

2014-10-30

Technicians have removed most of the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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

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 Uncovering of Spacecraft

NASA Image and Video Library

2014-10-30

Most of the protective covering has been removed from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, inside Building 1 D high 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

Preparations are underway to remove the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, from their protective shipping container 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

Preparations are underway to tow two of the observatories, the lower stack, mini-stack number 1, for NASA's Magnetospheric Multiscale Observatory, or MMS, from the Building 2 south encapsulation bay to the Building 1 high 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 Uncovering of Spacecraft

NASA Image and Video Library

2014-10-30

Preparations are underway to remove the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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

Workers surround two of the observatories, the lower stack, mini-stack number 1, for NASA's Magnetospheric Multiscale Observatory, or MMS, on their trip from the Building 2 south encapsulation bay to the Building 1 high 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.

MMS Spacecraft Uncrated & Moved

NASA Image and Video Library

2014-10-29

The protective shipping container is lifted from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, 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 Uncovering of Spacecraft

NASA Image and Video Library

2014-10-30

A technician prepares to remove the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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.

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.

Three-dimensional vapor intrusion modeling approach that combines wind and stack effects on indoor, atmospheric, and subsurface domains.

PubMed

Shirazi, Elham; Pennell, Kelly G

2017-12-13

Vapor intrusion (IV) exposure risks are difficult to characterize due to the role of atmospheric, building and subsurface processes. This study presents a three-dimensional VI model that extends the common subsurface fate and transport equations to incorporate wind and stack effects on indoor air pressure, building air exchange rate (AER) and indoor contaminant concentration to improve VI exposure risk estimates. The model incorporates three modeling programs: (1) COMSOL Multiphysics to model subsurface fate and transport processes, (2) CFD0 to model atmospheric air flow around the building, and (3) CONTAM to model indoor air quality. The combined VI model predicts AER values, zonal indoor air pressures and zonal indoor air contaminant concentrations as a function of wind speed, wind direction and outdoor and indoor temperature. Steady state modeling results for a single-story building with a basement demonstrate that wind speed, wind direction and opening locations in a building play important roles in changing the AER, indoor air pressure, and indoor air contaminant concentration. Calculated indoor air pressures ranged from approximately -10 Pa to +4 Pa depending on weather conditions and building characteristics. AER values, mass entry rates and indoor air concentrations vary depending on weather conditions and building characteristics. The presented modeling approach can be used to investigate the relationship between building features, AER, building pressures, soil gas concentrations, indoor air concentrations and VI exposure risks.

Heat transfer optimization for air-mist cooling between a stack of parallel plates

NASA Astrophysics Data System (ADS)

Issa, Roy J.

2010-06-01

A theoretical model is developed to predict the upper limit heat transfer between a stack of parallel plates subject to multiphase cooling by air-mist flow. The model predicts the optimal separation distance between the plates based on the development of the boundary layers for small and large separation distances, and for dilute mist conditions. Simulation results show the optimal separation distance to be strongly dependent on the liquid-to-air mass flow rate loading ratio, and reach a limit for a critical loading. For these dilute spray conditions, complete evaporation of the droplets takes place. Simulation results also show the optimal separation distance decreases with the increase in the mist flow rate. The proposed theoretical model shall lead to a better understanding of the design of fins spacing in heat exchangers where multiphase spray cooling is used.

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.

Treatment of synthetic arsenate wastewater with iron-air fuel cell electrocoagulation to supply drinking water and electricity in remote areas.

PubMed

Kim, Jung Hwan; Maitlo, Hubdar Ali; Park, Joo Yang

2017-05-15

Electrocoagulation with an iron-air fuel cell is an innovative arsenate removal system that can operate without an external electricity supply. Thus, this technology is advantageous for treating wastewater in remote regions where it is difficult to supply electricity. In this study, the possibility of real applications of this system for arsenate treatment with electricity production was verified through electrolyte effect investigations using a small-scale fuel cell and performance testing of a liter-scale fuel cell stack. The electrolyte species studied were NaCl, Na 2 SO 4 , and NaHCO 3 . NaCl was overall the most effective electrolyte for arsenate treatment, although Na 2 SO 4 produced the greatest electrical current and power density. In addition, although the current density and power density were proportional to the concentrations of NaCl and Na 2 SO 4 , the use of concentrations above 20 mM of NaCl and Na 2 SO 4 inhibited arsenate treatment due to competition effects between anions and arsenate in adsorption onto the iron hydroxide. The dominant iron hydroxide produced at the iron anode was found to be lepidocrocite by means of Raman spectroscopy. A liter-scale four-stack iron-air fuel cell with 10 mM NaCl electrolyte was found to be able to treat about 300 L of 1 ppm arsenate solution to below 10 ppb during 1 day, based on its 60-min treatment capacity, as well as produce the maximum power density of 250 mW/m 2 . Copyright © 2017 Elsevier Ltd. All rights reserved.

NASA PEMFC Development Background and History

NASA Technical Reports Server (NTRS)

Hoberecht, Mark

2011-01-01

NASA has been developing proton-exchange-membrane (PEM) fuel cell power systems for the past decade, as an upgraded technology to the alkaline fuel cells which presently provide power for the Shuttle Orbiter. All fuel cell power systems consist of one or more fuel cell stacks in combination with appropriate balance-of-plant hardware. Traditional PEM fuel cells are characterized as flow-through, in which recirculating reactant streams remove product water from the fuel cell stack. NASA recently embarked on the development of non-flow-through fuel cell systems, in which reactants are dead-ended into the fuel cell stack and product water is removed by internal wicks. This simplifies the fuel cell power system by eliminating the need for pumps to provide reactant circulation, and mechanical water separators to remove the product water from the recirculating reactant streams. By eliminating these mechanical components, the resulting fuel cell power system has lower mass, volume, and parasitic power requirements, along with higher reliability and longer life. Four vendors have designed and fabricated non-flow-through fuel cell stacks under NASA funding. One of these vendors is considered the "baseline" vendor, and the remaining three vendors are competing for the "alternate" role. Each has undergone testing of their stack hardware integrated with a NASA balance-of-plant. Future Exploration applications for this hardware include primary fuel cells for a Lunar Lander and regenerative fuel cells for Surface Systems.

Self-Driven Desalination and Advanced Treatment of Wastewater in a Modularized Filtration Air Cathode Microbial Desalination Cell.

PubMed

Zuo, Kuichang; Wang, Zhen; Chen, Xi; Zhang, Xiaoyuan; Zuo, Jiaolan; Liang, Peng; Huang, Xia

2016-07-05

Microbial desalination cells (MDCs) extract organic energy from wastewater for in situ desalination of saline water. However, to desalinate salt water, traditional MDCs often require an anolyte (wastewater) and a catholyte (other synthetic water) to produce electricity. Correspondingly, the traditional MDCs also produced anode effluent and cathode effluent, and may produce a concentrate solution, resulting in a low production of diluate. In this study, nitrogen-doped carbon nanotube membranes and Pt carbon cloths were utilized as filtration material and cathode to fabricate a modularized filtration air cathode MDC (F-MDC). With real wastewater flowing from anode to cathode, and finally to the middle membrane stack, the diluate volume production reached 82.4%, with the removal efficiency of salinity and chemical oxygen demand (COD) reached 93.6% and 97.3% respectively. The final diluate conductivity was 68 ± 12 μS/cm, and the turbidity was 0.41 NTU, which were sufficient for boiler supplementary or industrial cooling. The concentrate production was only 17.6%, and almost all the phosphorus and salt, and most of the nitrogen were recovered, potentially allowing the recovery of nutrients and other chemicals. These results show the potential utility of the modularized F-MDC in the application of municipal wastewater advanced treatment and self-driven desalination.

AB-stacked square-like bilayer ice in graphene nanocapillaries.

PubMed

Zhu, YinBo; Wang, FengChao; Bai, Jaeil; Zeng, Xiao Cheng; Wu, HengAn

2016-08-10

Water, when constrained between two graphene sheets and under ultrahigh pressure, can manifest dramatic differences from its bulk counterparts such as the van der Waals pressure induced water-to-ice transformation, known as the metastability limit of two-dimensional (2D) liquid. Here, we present result of a new crystalline structure of bilayer ice with the AB-stacking order, observed from molecular dynamics simulations of constrained water. This AB-stacked bilayer ice (BL-ABI) is transformed from the puckered monolayer square-like ice (pMSI) under higher lateral pressure in the graphene nanocapillary at ambient temperature. BL-ABI is a proton-ordered ice with square-like pattern. The transition from pMSI to BL-ABI is through crystal-to-amorphous-to-crystal pathway with notable hysteresis-loop in the potential energy during the compression/decompression process, reflecting the compression/tensile limit of the 2D monolayer/bilayer ice. In a superheating process, the BL-ABI transforms into the AB-stacked bilayer amorphous ice with the square-like pattern.

Nuclear reactor reflector

DOEpatents

Hopkins, Ronald J.; Land, John T.; Misvel, Michael C.

1994-01-01

A nuclear reactor reflector is disclosed that comprises a stack of reflector blocks with vertical water flow passages to cool the reflector. The interface between blocks is opposite support points for reactor fuel rods. Water flows between the reflector and the reactor barrel from passages in a bottom block. The top block contains a flange to limit this flow and the flange has a slot to receive an alignment pin that is welded to the barrel. The pin is held in the slot by two removable shims. Alignment bars extend the length of the stack in slots machined in each block when the stack is assembled.

Nuclear reactor reflector

DOEpatents

Hopkins, R.J.; Land, J.T.; Misvel, M.C.

1994-06-07

A nuclear reactor reflector is disclosed that comprises a stack of reflector blocks with vertical water flow passages to cool the reflector. The interface between blocks is opposite support points for reactor fuel rods. Water flows between the reflector and the reactor barrel from passages in a bottom block. The top block contains a flange to limit this flow and the flange has a slot to receive an alignment pin that is welded to the barrel. The pin is held in the slot by two removable shims. Alignment bars extend the length of the stack in slots machined in each block when the stack is assembled. 12 figs.

Sampling for Air Chemical Emissions from the Life Sciences Laboratory II

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

Ballinger, Marcel Y.; Lindberg, Michael J.

Sampling for air chemical emissions from the Life Science Laboratory II (LSL-II) ventilation stack was performed in an effort to determine potential exposure of maintenance staff to laboratory exhaust on the building roof. The concern about worker exposure was raised in December 2015 and several activities were performed to assist in estimating exposure concentrations. Data quality objectives were developed to determine the need for and scope and parameters of a sampling campaign to measure chemical emissions from research and development activities to the outside air. The activities provided data on temporal variation of air chemical concentrations and a basis formore » evaluating calculated emissions. Sampling for air chemical emissions was performed in the LSL-II ventilation stack over the 6-week period from July 26 to September 1, 2016. A total of 12 sampling events were carried out using 16 sample media. Resulting analysis provided concentration data on 49 analytes. All results were below occupational exposure limits and most results were below detection limits. When compared to calculated emissions, only 5 of the 49 chemicals had measured concentrations greater than predicted. This sampling effort will inform other study components to develop a more complete picture of a worker’s potential exposure from LSL-II rooftop activities. Mixing studies were conducted to inform spatial variation in concentrations at other rooftop locations and can be used in conjunction with these results to provide temporal variations in concentrations for estimating the potential exposure to workers working in and around the LSL-II stack.« less

Proton exchange membrane fuel cells for space and electric vehicle applications: From basic research to technology development

NASA Technical Reports Server (NTRS)

Srinivasan, Supramaniam; Mukerjee, Sanjeev; Parthasarathy, A.; CesarFerreira, A.; Wakizoe, Masanobu; Rho, Yong Woo; Kim, Junbom; Mosdale, Renaut A.; Paetzold, Ronald F.; Lee, James

1994-01-01

The proton exchange membrane fuel cell (PEMFC) is one of the most promising electrochemical power sources for space and electric vehicle applications. The wide spectrum of R&D activities on PEMFC's, carried out in our Center from 1988 to date, is as follows (1) Electrode Kinetic and Electrocatalysis of Oxygen Reduction; (2) Optimization of Structures of Electrodes and of Membrane and Electrode Assemblies; (3) Selection and Evaluation of Advanced Proton Conducting Membranes and of Operating Conditions to Attain High Energy Efficiency; (4) Modeling Analysis of Fuel Cell Performance and of Thermal and Water Management; and (5) Engineering Design and Development of Multicell Stacks. The accomplishments on these tasks may be summarized as follows: (1) A microelectrode technique was developed to determine the electrode kinetic parameters for the fuel cell reactions and mass transport parameters for the H2 and O2 reactants in the proton conducting membrane. (2) High energy efficiencies and high power densities were demonstrated in PEMFCs with low platinum loading electrodes (0.4 mg/cm(exp 2) or less), advanced membranes and optimized structures of membrane and electrode assemblies, as well as operating conditions. (3) The modeling analyses revealed methods to minimize mass transport limitations, particularly with air as the cathodic reactant; and for efficient thermal and water management. (4) Work is in progress to develop multi-kilowatt stacks with the electrodes containing low platinum loadings.

Molecular dynamics simulation studies of caffeine aggregation in aqueous solution.

PubMed

Tavagnacco, Letizia; Schnupf, Udo; Mason, Philip E; Saboungi, Marie-Louise; Cesàro, Attilio; Brady, John W

2011-09-22

Molecular dynamics simulations were carried out on a system of eight independent caffeine molecules in a periodic box of water at 300 K, representing a solution near the solubility limit for caffeine at room temperature, using a newly developed CHARMM-type force field for caffeine in water. Simulations were also conducted for single caffeine molecules in water using two different water models (TIP3P and TIP4P). Water was found to structure in a complex fashion around the planar caffeine molecules, which was not sensitive to the water model used. As expected, extensive aggregation of the caffeine molecules was observed, with the molecules stacking their flat faces against one another like coins, with their methylene groups staggered to avoid steric clashes. A dynamic equilibrum was observed between large n-mers, including stacks with all eight solute molecules, and smaller clusters, with the calculated osmotic coefficient being in acceptable agreement with the experimental value. The insensitivity of the results to water model and the congruence with experimental thermodynamic data suggest that the observed stacking interactions are a realistic representation of the actual association mechanism in aqueous caffeine solutions.

Air drying of softwood lumber, Fairbanks, Alaska.

Treesearch

George R Sampson; Forrest A. Ruppert

1985-01-01

Air-drying rates for two stacks of 2-inch-thick white spruce were observed in the Fairbanks area during summer 1982. The air-drying rate for the same size lumber was also observed during winter 1982-83. Very little drying occurred during the winter. Drying rates in summer were correlated with average daily temperature and average daily dew point to derive predictive...

Graphene membranes with nanoslits for seawater desalination via forward osmosis.

PubMed

Dahanayaka, Madhavi; Liu, Bo; Hu, Zhongqiao; Pei, Qing-Xiang; Chen, Zhong; Law, Adrian Wing-Keung; Zhou, Kun

2017-11-22

Stacked graphene (GE) membranes with cascading nanoslits can be synthesized economically compared to monolayer nanoporous GE membranes, and have potential for molecular separation. This study focuses on investigating the seawater desalination performance of these stacked GE layers as forward osmosis (FO) membranes by using molecular dynamics simulations. The FO performance is evaluated in terms of water flux and salt rejection and is explained by analysing the water density distribution and radial distribution function. The water flow displays an Arrhenius type relation with temperature and the activation energy for the stacked GE membrane is estimated to be 8.02 kJ mol -1 , a value much lower than that of commercially available FO membranes. The study reveals that the membrane characteristics including the pore width, offset, interlayer separation distance and number of layers have significant effects on the desalination performance. Unlike monolayer nanoporous GE membranes, at an optimum layer separation distance, the stacked GE membranes with large pore widths and completely misaligned pore configuration can retain complete ion rejection and maintain a high water flux. Findings from the present study are helpful in developing GE-based membranes for seawater desalination via FO.

KSC-2014-4351

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, roll into the Building 1 airlock 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

MMS Spacecraft Uncrated & Moved

NASA Image and Video Library

2014-10-29

Workers attach a crane to the protective shipping container to prepare to uncover the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS. They were delivered to 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.

Stable isotope insights into the weathering processes of a phosphogypsum disposal area.

PubMed

Papaslioti, Evgenia-Maria; Pérez-López, Rafael; Parviainen, Annika; Macías, Francisco; Delgado-Huertas, Antonio; Garrido, Carlos J; Marchesi, Claudio; Nieto, José M

2018-04-28

Highly acidic phosphogypsum wastes with elevated potential for contaminant leaching are stack-piled near coastal areas worldwide, threatening the adjacent environment. Huge phosphogypsum stacks were disposed directly on the marshes of the Estuary of Huelva (SW Spain) without any impermeable barrier to prevent leaching and thus, contributing to the total contamination of the estuarine environment. According to the previous weathering model, the process water ponded on the surface of the stack, initially used to carry the waste, was thought to be the main washing agent through its infiltration and subsequently the main component of the leachates emerging as the edge outflows. Preliminary restorations have been applied to the site and similar ones are planned for the future considering process water as the only pollution agent. Further investigation to validate the pollution pathway was necessary, thus an evaluation of the relationship between leachates and weathering agents of the stack was carried out using stable isotopes (δ 18 O, δ 2 H, and δ 34 S) as geochemical tracers. Quantification of the contribution of all possible end-members to the phosphogypsum leachates was also conducted using ternary mixing via the stable isotopic tracers. The results ruled out ponded process water as main vector of edge outflow pollution and unveiled a continuous infiltration of estuarine waters to the stack implying that is subjected to an open weathering system. The isotopic tracers revealed a progressive contribution downstream from fluvial to marine signatures in the composition of the edge outflows, depending on the location of each disposal zone within the different estuarine morphodynamic domains. Thus, the current study suggests that the access of intertidal water inside the phosphogypsum stack, for instance through secondary tidal channels, is the main responsible for the weathering of the waste in depth, underlying the necessity for new, more effective restorations plans. Copyright © 2018 Elsevier Ltd. All rights reserved.

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.

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.

Solid oxide fuel cell generator with removable modular fuel cell stack configurations

DOEpatents

Gillett, J.E.; Dederer, J.T.; Zafred, P.R.; Collie, J.C.

1998-04-21

A high temperature solid oxide fuel cell generator produces electrical power from oxidation of hydrocarbon fuel gases such as natural gas, or conditioned fuel gases, such as carbon monoxide or hydrogen, with oxidant gases, such as air or oxygen. This electrochemical reaction occurs in a plurality of electrically connected solid oxide fuel cells bundled and arrayed in a unitary modular fuel cell stack disposed in a compartment in the generator container. The use of a unitary modular fuel cell stack in a generator is similar in concept to that of a removable battery. The fuel cell stack is provided in a pre-assembled self-supporting configuration where the fuel cells are mounted to a common structural base having surrounding side walls defining a chamber. Associated generator equipment may also be mounted to the fuel cell stack configuration to be integral therewith, such as a fuel and oxidant supply and distribution systems, fuel reformation systems, fuel cell support systems, combustion, exhaust and spent fuel recirculation systems, and the like. The pre-assembled self-supporting fuel cell stack arrangement allows for easier assembly, installation, maintenance, better structural support and longer life of the fuel cells contained in the fuel cell stack. 8 figs.

Solid oxide fuel cell generator with removable modular fuel cell stack configurations

DOEpatents

Gillett, James E.; Dederer, Jeffrey T.; Zafred, Paolo R.; Collie, Jeffrey C.

1998-01-01

A high temperature solid oxide fuel cell generator produces electrical power from oxidation of hydrocarbon fuel gases such as natural gas, or conditioned fuel gases, such as carbon monoxide or hydrogen, with oxidant gases, such as air or oxygen. This electrochemical reaction occurs in a plurality of electrically connected solid oxide fuel cells bundled and arrayed in a unitary modular fuel cell stack disposed in a compartment in the generator container. The use of a unitary modular fuel cell stack in a generator is similar in concept to that of a removable battery. The fuel cell stack is provided in a pre-assembled self-supporting configuration where the fuel cells are mounted to a common structural base having surrounding side walls defining a chamber. Associated generator equipment may also be mounted to the fuel cell stack configuration to be integral therewith, such as a fuel and oxidant supply and distribution systems, fuel reformation systems, fuel cell support systems, combustion, exhaust and spent fuel recirculation systems, and the like. The pre-assembled self-supporting fuel cell stack arrangement allows for easier assembly, installation, maintenance, better structural support and longer life of the fuel cells contained in the fuel cell stack.

A disposable power source in resource-limited environments: A paper-based biobattery generating electricity from wastewater.

PubMed

Fraiwan, Arwa; Kwan, Landen; Choi, Seokheun

2016-11-15

We report a novel paper-based biobattery which generates power from microorganism-containing liquid derived from renewable and sustainable wastewater which is readily accessible in the local environment. The device fuses the art of origami and the technology of microbial fuel cells (MFCs) and has the potential to shift the paradigm for flexible and stackable paper-based batteries by enabling exceptional electrical characteristics and functionalities. 3D, modular, and retractable battery stack is created from (i) 2D paper sheets through high degrees of folding and (ii) multifunctional layers sandwiched for MFC device configuration. The stack is based on ninja star-shaped origami design formed by eight MFC modular blades, which is retractable from sharp shuriken (closed) to round frisbee (opened). The microorganism-containing wastewater is added into an inlet of the closed battery stack and it is transported into each MFC module through patterned fluidic pathways in the paper layers. During operation, the battery stack is transformed into the round frisbee to connect eight MFC modules in series for improving the power output and simultaneously expose all air-cathodes to the air for their cathodic reactions. The device generates desired values of electrical current and potential for powering an LED for more than 20min. Copyright © 2016 Elsevier B.V. All rights reserved.

Experimental research of high frequency standing wave thermoacoustic refrigerator driven by loudspeaker

NASA Astrophysics Data System (ADS)

Chunping, Zhang; Wei, Liu; Zhichun, Yang; Zhengyu, Li; Xiaoqing, Zhang; Feng, Wu

2012-05-01

A small size standing wave thermoacoustic refrigerator driven by a high frequency loudspeaker has been experimentally studied. Instead of water cooling, the cold heat exchanger of the refrigerator was cooled by air through fins on it. By working at 600-700 Hz and adjusting the position of the thermoacoustic core components including the stack and adjacent exchangers, the influences of it on the capability of refrigeration were experimentally investigated. The lowest temperature of 4.1 °C in the cold heat exchanger with the highest temperature difference of 21.5 °C between two heat exchangers were obtained. And the maximum cooling power of 9.7 W has been achieved.

New design of a PEFC cathode separator of for water management

NASA Astrophysics Data System (ADS)

Sugiura, K.; Takahashi, N.; Kamimura, T.

2017-11-01

Generally, polymer electrolyte fuel cells (PEFCs) need humidifiers to prevent the drying of the membrane, but this use of humidifiers creates water management issues, such as the flooding/plugging phenomena and decreased system efficiency because of an increase in the electric energy needed for auxiliary equipment. Although most researchers have developed high-temperature membranes that do not need humidifiers, a lot of time is necessary for the development of these membranes, and these membranes drive up costs. Therefore, we propose a new cathode separator design that can recycle water generated by power generation in the same cell and a stack structure that can redistribute water collected in the cathode outlet manifold to drying cells. Because the new cathode separator has a bypass channel from the gas outlet to the gas inlet to transport excess water, a dry part in the gas inlet is supplied with excess water in the gas outlet through the bypass channel even if the PEFC is operated under dry conditions. Excess water in the PEFC stack can be transported from the cell with excess water to the drying cell through the cathode outlet manifold with a porous wall. Therefore, we confirm the influence of the plugging phenomenon in the cathode gas outlet manifold on the cell performance of each cell in the stack. As a result, the cell performance of the new cathode separator design is better than that of the standard separator under the low humidity conditions. We confirm that the plugging phenomenon in the cathode outlet manifold affects the cell performance of each cell in the stack.

6-[6-(Pyridin-2-yl)-1,2,4,5-tetra-zin-3-yl]pyridin-3-amine monohydrate.

PubMed

Broichhagen, Johannes; Klingl, Yvonne E; Trauner, Dirk; Mayer, Peter

2016-02-01

The packing of the title compound, C12H9N7·H2O, is dominated by hydrogen bonding and π-stacking. Layers parallel to [010] are established by hydrogen bonds involving all amine donor functions and one of the water donor functions, while the remaining water donor function enables the stacking of the layers along [10-1], which is accompanied by π-stacking. In the molecule, the plane of the central tetra-zine ring forms angles of 5.33 (7) and 19.84 (8)° with the adjacent 3-amine-pyridine and pyridine rings, respectively.

Interlayer Water Regulates the Bio-nano Interface of a β-sheet Protein stacking on Graphene

PubMed Central

Lv, Wenping; Xu, Guiju; Zhang, Hongyan; Li, Xin; Liu, Shengju; Niu, Huan; Xu, Dongsheng; Wu, Ren'an

2015-01-01

Using molecular dynamics simulations, we investigated an integrated bio-nano interface consisting of a β-sheet protein stacked onto graphene. We found that the stacking assembly of the model protein on graphene could be controlled by water molecules. The interlayer water filled within interstices of the bio-nano interface could suppress the molecular vibration of surface groups on protein, and could impair the CH···π interaction driving the attraction of the protein and graphene. The intermolecular coupling of interlayer water would be relaxed by the relative motion of protein upon graphene due to the interaction between water and protein surface. This effect reduced the hindrance of the interlayer water against the assembly of protein on graphene, resulting an appropriate adsorption status of protein on graphene with a deep free energy trap. Thereby, the confinement and the relative sliding between protein and graphene, the coupling of protein and water, and the interaction between graphene and water all have involved in the modulation of behaviors of water molecules within the bio-nano interface, governing the hindrance of interlayer water against the protein assembly on hydrophobic graphene. These results provide a deep insight into the fundamental mechanism of protein adsorption onto graphene surface in water. PMID:25557857

Interlayer water regulates the bio-nano interface of a β-sheet protein stacking on graphene.

PubMed

Lv, Wenping; Xu, Guiju; Zhang, Hongyan; Li, Xin; Liu, Shengju; Niu, Huan; Xu, Dongsheng; Wu, Ren'an

2015-01-05

Using molecular dynamics simulations, we investigated an integrated bio-nano interface consisting of a β-sheet protein stacked onto graphene. We found that the stacking assembly of the model protein on graphene could be controlled by water molecules. The interlayer water filled within interstices of the bio-nano interface could suppress the molecular vibration of surface groups on protein, and could impair the CH···π interaction driving the attraction of the protein and graphene. The intermolecular coupling of interlayer water would be relaxed by the relative motion of protein upon graphene due to the interaction between water and protein surface. This effect reduced the hindrance of the interlayer water against the assembly of protein on graphene, resulting an appropriate adsorption status of protein on graphene with a deep free energy trap. Thereby, the confinement and the relative sliding between protein and graphene, the coupling of protein and water, and the interaction between graphene and water all have involved in the modulation of behaviors of water molecules within the bio-nano interface, governing the hindrance of interlayer water against the protein assembly on hydrophobic graphene. These results provide a deep insight into the fundamental mechanism of protein adsorption onto graphene surface in water.

Interlayer Water Regulates the Bio-nano Interface of a β-sheet Protein stacking on Graphene

NASA Astrophysics Data System (ADS)

Lv, Wenping; Xu, Guiju; Zhang, Hongyan; Li, Xin; Liu, Shengju; Niu, Huan; Xu, Dongsheng; Wu, Ren'an

2015-01-01

Using molecular dynamics simulations, we investigated an integrated bio-nano interface consisting of a β-sheet protein stacked onto graphene. We found that the stacking assembly of the model protein on graphene could be controlled by water molecules. The interlayer water filled within interstices of the bio-nano interface could suppress the molecular vibration of surface groups on protein, and could impair the CH...π interaction driving the attraction of the protein and graphene. The intermolecular coupling of interlayer water would be relaxed by the relative motion of protein upon graphene due to the interaction between water and protein surface. This effect reduced the hindrance of the interlayer water against the assembly of protein on graphene, resulting an appropriate adsorption status of protein on graphene with a deep free energy trap. Thereby, the confinement and the relative sliding between protein and graphene, the coupling of protein and water, and the interaction between graphene and water all have involved in the modulation of behaviors of water molecules within the bio-nano interface, governing the hindrance of interlayer water against the protein assembly on hydrophobic graphene. These results provide a deep insight into the fundamental mechanism of protein adsorption onto graphene surface in water.

Determination of hexavalent chromium concentration in industrial waste incinerator stack gas by using a modified ion chromatography with post-column derivatization method.

PubMed

Miyake, Yuichi; Tokumura, Masahiro; Iwazaki, Yuta; Wang, Qi; Amagai, Takashi; Horii, Yuichi; Otsuka, Hideyuki; Tanikawa, Noboru; Kobayashi, Takeshi; Oguchi, Masahiro

2017-06-16

An ion chromatography with post-column derivatization with 1,5-diphenylcarbazide (IC-DPC) analytical method was modified to enable measurement of trace-level hexavalent chromium (Cr(VI)) in air. One of the difficulties in determining trace levels of Cr(VI) in air with conventional IC-DPC methods is co-elution of the solvent and ion peaks due to high concentrations of ionic compounds in the extract. However, by using gradient elution rather than isocratic elution we were able to fully resolve the Cr(VI) ion peak from the solvent peak without the need for diluting the extract, which would have reduced the minimum quantifiable level of the method. With this method, we were able to detect Cr(VI) in air at concentrations of 5.3ng/m 3 (assuming a sampling volume of 1m 3 and a final solution volume of 10mL). Recovery tests at three different concentrations of Cr(VI) (50, 250, 1000ng) were performed with or without fly ash; recovery rates at all the concentrations of Cr(VI), with or without fly ash, ranged from 68% to 110% (mean±relative standard deviation, 96%±11%), and there were no differences in recovery rates with respect to the presence or absence of fly ash. Finally, we used the developed method to determine the concentration of Cr(VI) in stack gases collected from eight industrial waste incinerators located in Japan. The concentration of Cr(VI) in the stack gases ranged from below the method quantification limit to 3100ng/m 3 . The highest concentrations of Cr(VI) detected in the stack gases were two to three orders of magnitude higher than that in ambient air in Japan. Copyright © 2017 Elsevier B.V. All rights reserved.

The fate of mercury collected from air pollution control devices

EPA Science Inventory

The mercury that enters a coal-fired power plant, originates from the coal that is burned, and leaves through the output streams that include stack emissions and air pollution control (APC) residues (either in solid or liquid form). This article describes recent fmdings on the fa...

40 CFR 49.129 - Rule for limiting emissions of sulfur dioxide.

Code of Federal Regulations, 2010 CFR

2010-07-01

... emissions from a combustion source stack must not exceed an average of 500 parts per million by volume, on a..., air pollution source, ambient air, British thermal unit (Btu), coal, combustion source, continuous..., incinerator, marine vessel, mobile sources, motor vehicle, nonroad engine, nonroad vehicle, open burning...

40 CFR 49.129 - Rule for limiting emissions of sulfur dioxide.

Code of Federal Regulations, 2011 CFR

2011-07-01

... emissions from a combustion source stack must not exceed an average of 500 parts per million by volume, on a..., air pollution source, ambient air, British thermal unit (Btu), coal, combustion source, continuous..., incinerator, marine vessel, mobile sources, motor vehicle, nonroad engine, nonroad vehicle, open burning...

Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases

DOEpatents

Walker, Richard J.

1986-01-01

A continuous method is presented for removing both oxides of sulfur and oxides of nitrogen from combustion or exhaust gases with the regeneration of the absorbent. Exhaust gas is cleaned of particulates and HCl by a water scrub prior to contact with a liquid absorbent that includes an aqueous solution of bisulfite and sulfite ions along with a metal chelate, such as, an iron or zinc aminopolycarboxylic acid. Following contact with the combustion gases the spent absorbent is subjected to electrodialysis to transfer bisulfite ions into a sulfuric acid solution while splitting water with hydroxide and hydrogen ion migration to equalize electrical charge. The electrodialysis stack includes alternate layers of anion selective and bipolar membranes. Oxides of nitrogen are removed from the liquid absorbent by air stripping at an elevated temperature and the regenerated liquid absorbent is returned to contact with exhaust gases for removal of sulfur oxides and nitrogen oxides.

Water on graphene: review of recent progress

NASA Astrophysics Data System (ADS)

Melios, C.; Giusca, C. E.; Panchal, V.; Kazakova, O.

2018-04-01

The sensitivity of graphene to the surrounding environment is given by its π electrons, which are directly exposed to molecules in the ambient air. The high sensitivity of graphene to the local environment has shown to be both advantageous and problematic for graphene-based devices, such as transistors and sensors, where the graphene carrier concentration and mobility changes due to ambient humidity variations. In this review, recent progress is presented in understanding the effects of water on different types of graphene: epitaxially grown and quasi-free standing on SiC(0 0 0 1), grown by chemical vapour deposition and transfered on SiO2, and exfoliated flakes. It is demonstrated that water withdraws electrons from graphene, but the graphene-water interaction highly depends on the thickness, layer stacking, underlying substrate and substrate-induced doping. Moreover, we highlight the importance of clear and unambiguous description of the environmental conditions (i.e. relative humidity) whenever a routine characterisation for carrier concentration and mobility is reported (often presented as a simple figure-of-merit), as these electrical characteristics are highly dependent on the adsorbed molecules and the surrounding environment.

Atmospheric occurrence and health risks of PCDD/Fs, polychlorinated biphenyls, and polychlorinated naphthalenes by air inhalation in metallurgical plants.

PubMed

Yang, Lili; Liu, Guorui; Zheng, Minghui; Jin, Rong; Zhu, Qingqing; Zhao, Yuyang; Zhang, Xian; Xu, Yang

2017-02-15

Metallurgical plants are important sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs). It is significant to evaluate the air levels and human risks of PCDD/Fs, PCBs and PCNs in metallurgical plants considering their adverse effects on human health and thousands of metallurgical plants being in operation in China. The estimated inhalation intakes of PCDD/Fs, PCBs, and PCNs together in eight iron ore sintering plants, three secondary copper plants, four secondary aluminum plants, and one secondary lead plant were 4.9-213.4, 21.4-4026.4, 28.7-630, and 11.7fgTEQkg -1 day -1 , respectively, and the corresponding cancer risks were estimated to be 8.7×10 -7 to 3.8×10 -5 , 5.1×10 -6 to 1.1×10 -4 , 3.8×10 -6 to 7.1×10 -4 , and 2.1×10 -6 , respectively. The estimated cancer risk were higher than 100 per million people for three secondary aluminum and copper smelters among the sixteen metallurgical plants, indicating high cancer risks. Stack gas samples from metallurgical plants were also collected and analyzed for comparing their emission profiles with that of air samples. The comparison of PCDD/F, PCB and PCN profiles between air samples and stack gas samples by similarity calculation and principal component analysis suggested the influence of stack gas emissions from metallurgical plants on surrounding air. These results are helpful for understanding the exposure risk to PCDD/Fs, PCBs and PCNs in numerous metallurgical plants being operation in China. Copyright © 2016 Elsevier B.V. All rights reserved.

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-2014-4347

NASA Image and Video Library

2014-10-29

CAPE CANAVERAL, Fla. – Workers position two of the observatories, the lower stack, mini-stack number 1 for NASA's Magnetospheric Multiscale Observatory, or MMS, onto a payload dolly 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-2014-4356

NASA Image and Video Library

2014-10-30

CAPE CANAVERAL, Fla. – Technicians begin to remove the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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-2014-4353

NASA Image and Video Library

2014-10-30

CAPE CANAVERAL, Fla. – Preparations are underway to remove the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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-2014-4362

NASA Image and Video Library

2014-10-30

CAPE CANAVERAL, Fla. – Technicians have removed most of the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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

KSC-2014-4355

NASA Image and Video Library

2014-10-30

CAPE CANAVERAL, Fla. – Technicians prepare to remove the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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-2014-4340

NASA Image and Video Library

2014-10-29

CAPE CANAVERAL, Fla. – Preparations are underway to remove the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, from their protective shipping container 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-2014-4342

NASA Image and Video Library

2014-10-29

CAPE CANAVERAL, Fla. – The protective shipping container is lifted from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, 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-2014-4364

NASA Image and Video Library

2014-10-30

CAPE CANAVERAL, Fla. – Most of the protective covering has been removed from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, inside Building 1 D high 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-2014-4357

NASA Image and Video Library

2014-10-30

CAPE CANAVERAL, Fla. – Technicians begin to remove the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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-2014-4354

NASA Image and Video Library

2014-10-30

CAPE CANAVERAL, Fla. – A technician prepares to remove the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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-2014-4360

NASA Image and Video Library

2014-10-30

CAPE CANAVERAL, Fla. – Technicians remove the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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-2014-4348

NASA Image and Video Library

2014-10-29

CAPE CANAVERAL, Fla. – Preparations are underway to tow two of the observatories, the lower stack, mini-stack number 1, for NASA's Magnetospheric Multiscale Observatory, or MMS, from the Building 2 south encapsulation bay to the Building 1 high 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-2014-4363

NASA Image and Video Library

2014-10-30

CAPE CANAVERAL, Fla. – Most of the protective covering has been removed from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, inside Building 1 D high 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-2014-4358

NASA Image and Video Library

2014-10-30

CAPE CANAVERAL, Fla. – Technicians remove the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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-2014-4359

NASA Image and Video Library

2014-10-30

CAPE CANAVERAL, Fla. – Technicians remove the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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-2014-4361

NASA Image and Video Library

2014-10-30

CAPE CANAVERAL, Fla. – A technician carefully removes the protective covering from the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS, in Building 1 D high 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

Architecture of Pd-Au bimetallic nanoparticles in sodium bis(2-ethylhexyl)sulfosuccinate reverse micelles as investigated by X-ray absorption spectroscopy.

PubMed

Chen, Ching-Hsiang; Sarma, Loka Subramanyam; Chen, Jium-Ming; Shih, Shou-Chu; Wang, Guo-Rung; Liu, Din-Goa; Tang, Mau-Tsu; Lee, Jyh-Fu; Hwang, Bing-Joe

2007-09-01

In this study, we demonstrate the unique application of X-ray absorption spectroscopy (XAS) as a fundamental characterization tool to help in designing and controlling the architecture of Pd-Au bimetallic nanoparticles within a water-in-oil microemulsion system of water/sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/n-heptane. Structural insights obtained from the in situ XAS measurements recorded at each step during the formation process revealed that Pd-Au bimetallic clusters with various Pd-Au atomic stackings are formed by properly performing hydrazine reduction and redox transmetalation reactions sequentially within water-in-oil microemulsions. A structural model is provided to explain reasonably each reaction step and to give detailed insight into the nucleation and growth mechanism of Pd-Au bimetallic clusters. The combination of in situ XAS analysis at both the Pd K-edge and the Au L(III)-edge and UV-vis absorption spectral features confirms that the formation of Pd-Au bimetallic clusters follows a (Pd(nuclei)-Au(stack))-Pd(surf) stacking. This result further implies that the thickness of Au(stack) and Pd(surf) layers may be modulated by varying the dosage of the Au precursor and hydrazine, respectively. In addition, a bimetallic (Pd-Au)(alloy) nanocluster with a (Pd(nuclei)-Au(stack))-(Pd-Au(alloy))(surf) stacking was also designed and synthesized in order to check the feasibility of Pd(surf) layer modification. The result reveals that the Pd(surf) layer of the stacked (Pd(nuclei)-Au)(stack) bimetallic clusters can be successfully modified to form a (Au-Pd alloy)(surf) layer by a co-reduction of Pd and Au ions by hydrazine. Further, we demonstrate the alloying extent or atomic distribution of Pd and Au in Pd-Au bimetallic nanoparticles from the derived XAS structural parameters. The complete XAS-based methodology, demonstrated here on the Pd-Au bimetallic system, can easily be extended to design and control the alloying extent or atomic distribution, atomic stacking, and electronic structure to construct many other types of bimetallic systems for interesting applications.

7. View northwest of smoke stack on Armory Street Pump ...

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

7. View northwest of smoke stack on Armory Street Pump House. - Lake Whitney Water Filtration Plant, Armory Street Pumphouse, North side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

Co-flow anode/cathode supply heat exchanger for a solid-oxide fuel cell assembly

DOEpatents

Haltiner, Jr., Karl J.; Kelly, Sean M.

2005-11-22

In a solid-oxide fuel cell assembly, a co-flow heat exchanger is provided in the flow paths of the reformate gas and the cathode air ahead of the fuel cell stack, the reformate gas being on one side of the exchanger and the cathode air being on the other. The reformate gas is at a substantially higher temperature than is desired in the stack, and the cathode gas is substantially cooler than desired. In the co-flow heat exchanger, the temperatures of the reformate and cathode streams converge to nearly the same temperature at the outlet of the exchanger. Preferably, the heat exchanger is formed within an integrated component manifold (ICM) for a solid-oxide fuel cell assembly.

KSC-2009-1714

NASA Image and Video Library

2009-02-18

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, the crane in the foreground moves the cables used to lower NASA's Orbiting Carbon Observatory, OCO, upper stack onto to the Taurus XL Stage 0 motor behind it. The upper stack consists of Stages 1, 2 and 3 of the Taurus, as well as the encapsulated OCO spacecraft. OCO is scheduled for launch the Taurus rocket Feb. 24 from Vandenberg. The spacecraft will collect precise global measurements of carbon dioxide (CO2) in the Earth's atmosphere. Scientists will analyze OCO data to improve our understanding of the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Photo credit: NASA/Richard Nielsen, VAFB

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.

Development of an active isolation mat based on dielectric elastomer stack actuators for mechanical vibration cancellation

NASA Astrophysics Data System (ADS)

Karsten, Roman; Flittner, Klaus; Haus, Henry; Schlaak, Helmut F.

2013-04-01

This paper describes the development of an active isolation mat for cancelation of vibrations on sensitive devices with a mass of up to 500 gram. Vertical disturbing vibrations are attenuated actively while horizontal vibrations are damped passively. The dimensions of the investigated mat are 140 × 140 × 20 mm. The mat contains 5 dielectric elastomer stack actuators (DESA). The design and the optimization of active isolation mat are realized by ANSYS FEM software. The best performance shows a DESA with air cushion mounted on its circumference. Within the mounting encased air increases static and reduces dynamic stiffness. Experimental results show that vibrations with amplitudes up to 200 μm can be actively eliminated.

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.

Cell module and fuel conditioner development

NASA Astrophysics Data System (ADS)

Hoover, D. Q., Jr.

1980-01-01

Components for the first 5 cell stack (no cooling plates) of the MK-2 design were fabricated. Preliminary specfications and designs for the components of a 23 cell MK-1 stack with four DIGAS cooling plates were developed. The MK-2 was selected as a bench mark design and a preliminary design of the facilities required for high rate manufacture of fuel cell modules was developed. Two stands for testing 5 cell stacks were built and design work for modifying existing stands and building new stands for 23 and 80 cell stacks was initiated. Design and procurement of components and materials for the catalyst test stand were completed and construction initiated. Work on the specifications of pipeline gas, tap water and recovered water and definition of equipment required for treatment was initiated. An innovative geometry for the reformer was conceived and modifications of the computer program to be used in its design were stated.

[Effect of salts, stabilizing and destabilizing the structure of water, on the stacking association of adenosine].

PubMed

Maevskiĭ, A A; Sukhorukov, B I

1976-11-01

A spectrophotometric study, based on the concentration relationship of electron absorption spectra, of the effects of salts which stabilize and destabilize the water structure on the constant (K) of adenosine: stacking association has been carried out. A significant decrease of K was observed in NaClO4 which embodied strong destabilizing effect. Opposite effect was observed on other salts studied. According to K value the stacking-interaction of adenosine in the range of salt concentration 0 divided by 3M for different anions and cations are arranged in rows: SO4--greater than Cl- greater than ClO4-; Na+ greater than Li+greater than K+. The data obtained suggest that the effect of salts on thermostability of various oligo- and polynucleotides and on B leads to C DNA transition may be essentially concerned with the effect of both cations and anions of salts on the stacking-interaction of bases.

Molecular Dynamics Simulation Studies of Caffeine Aggregation in Aqueous Solution

PubMed Central

Tavagnacco, Letizia; Schnupf, Udo; Mason, Philip E.; Saboungi, Marie-Louise; Cesàro, Attilio; Brady, John W.

2011-01-01

Molecular dynamics simulations were carried out on a system of eight independent caffeine molecules in a periodic box of water at 300 K, representing a solution near the solubility limit for caffeine at room temperature, using a newly-developed CHARMM-type force field for caffeine in water. Simulations were also conducted for single caffeine molecules in water using two different water models (TIP3P and TIP4P). Water was found to structure in a complex fashion around the planar caffeine molecules, which was not sensitive to the water model used. As expected, extensive aggregation of the caffeine molecules was observed, with the molecules stacking their flat faces against one another like coins, with their methylene groups staggered to avoid steric clashes. A dynamic equilibrum was observed between large n-mers, including stacks with all eight solute molecules, and smaller clusters, with the calculated osmotic coefficient being in acceptable agreement with the experimental value. The insensitivity of the results to water model and the congruence with experimental thermodynamic data suggest that the observed stacking interactions are a realistic representation of the actual association mechanism in aqueous caffeine solutions. PMID:21812485

Long-term evaluation of solid oxide fuel cell candidate materials in a 3-cell generic short stack fixture, Part II: sealing glass stability, microstructure and interfacial reactions.

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

Chou, Y. S.; Stevenson, Jeffry W.; Choi, Jung-Pyung

2014-03-15

A generic solid oxide fuel cell stack test fixture was developed to evaluate candidate materials and processing methods under realistic conditions. Part I of the work addressed the stack fixture, seal system and cell performance of a 3-cell short stack tested at 800oC for 6000h. Commercial NiO-YSZ anode-supported thin YSZ electrolyte cells with LSM cathodes were used for assessment and were tested in constant current mode with dilute (~50% H2) fuel versus air. Part II of the work examined the sealing glass stability, microstructure development, interfacial reactions, and volatility issues. Part III of the work investigated the stability of Ce-(Mn,Co)more » spinel coating, AISI441 metallic interconnect, alumina coating, and cell degradation. After 6000h of testing, the refractory sealing glass YSO77 (Ba-Sr-Y-B-Si) showed desirable chemical compatibility with YSZ electrolyte in that no discernable interfacial reaction was identified, consistent with thermodynamic calculations. In addition, no glass penetration into the thin electrolyte was observed. At the aluminized AISI441 interface, the protective alumina coating appeared to be corroded by the sealing glass. Air side interactions appeared to be more severe than fuel side interactions. Metal species such as Cr, Mn, and Fe were detected in the glass, but were limited to the vicinity of the interface. No alkaline earth chromates were found at the air side. Volatility was also studied in a similar glass and weight loss in a wet reducing environment was determined. Using the steady-state volatility data, the life time (40,000h) weight loss of refractory sealing glass YSO77 was estimated to be less than 0.1 wt%.« less

Hardware/Software Data Acquisition System for Real Time Cell Temperature Monitoring in Air-Cooled Polymer Electrolyte Fuel Cells

PubMed Central

Bartolucci, Veronica

2017-01-01

This work presents a hardware/software data acquisition system developed for monitoring the temperature in real time of the cells in Air-Cooled Polymer Electrolyte Fuel Cells (AC-PEFC). These fuel cells are of great interest because they can carry out, in a single operation, the processes of oxidation and refrigeration. This allows reduction of weight, volume, cost and complexity of the control system in the AC-PEFC. In this type of PEFC (and in general in any PEFC), the reliable monitoring of temperature along the entire surface of the stack is fundamental, since a suitable temperature and a regular distribution thereof, are key for a better performance of the stack and a longer lifetime under the best operating conditions. The developed data acquisition (DAQ) system can perform non-intrusive temperature measurements of each individual cell of an AC-PEFC stack of any power (from watts to kilowatts). The stack power is related to the temperature gradient; i.e., a higher power corresponds to a higher stack surface, and consequently higher temperature difference between the coldest and the hottest point. The developed DAQ system has been implemented with the low-cost open-source platform Arduino, and it is completed with a modular virtual instrument that has been developed using NI LabVIEW. Temperature vs time evolution of all the cells of an AC-PEFC both together and individually can be registered and supervised. The paper explains comprehensively the developed DAQ system together with experimental results that demonstrate the suitability of the system. PMID:28698497

Hardware/Software Data Acquisition System for Real Time Cell Temperature Monitoring in Air-Cooled Polymer Electrolyte Fuel Cells.

PubMed

Segura, Francisca; Bartolucci, Veronica; Andújar, José Manuel

2017-07-09

This work presents a hardware/software data acquisition system developed for monitoring the temperature in real time of the cells in Air-Cooled Polymer Electrolyte Fuel Cells (AC-PEFC). These fuel cells are of great interest because they can carry out, in a single operation, the processes of oxidation and refrigeration. This allows reduction of weight, volume, cost and complexity of the control system in the AC-PEFC. In this type of PEFC (and in general in any PEFC), the reliable monitoring of temperature along the entire surface of the stack is fundamental, since a suitable temperature and a regular distribution thereof, are key for a better performance of the stack and a longer lifetime under the best operating conditions. The developed data acquisition (DAQ) system can perform non-intrusive temperature measurements of each individual cell of an AC-PEFC stack of any power (from watts to kilowatts). The stack power is related to the temperature gradient; i.e., a higher power corresponds to a higher stack surface, and consequently higher temperature difference between the coldest and the hottest point. The developed DAQ system has been implemented with the low-cost open-source platform Arduino, and it is completed with a modular virtual instrument that has been developed using NI LabVIEW. Temperature vs time evolution of all the cells of an AC-PEFC both together and individually can be registered and supervised. The paper explains comprehensively the developed DAQ system together with experimental results that demonstrate the suitability of the system.

77 FR 39177 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Regional Haze

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-02

... of SO 2 from each of 167 stacks in 19 states, 28 percent control of non-EGU SO 2 emissions, and... INFORMATION CONTACT: Charles Hatten, Environmental Engineer, Control Strategies Section, Air Programs Branch... Directors Consortium (LADCO), Ohio identified one non-electric generating unit (non-EGU) source, P.H...

40 CFR 93.159 - Procedures for conformity determinations of general Federal actions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... based on the applicable air quality models, data bases, and other requirements specified in the most... applicable air quality models, data bases, and other requirements specified in the most recent version of the... data are available, such as actual stack test data from stationary sources which are part of the...

Characterization of Coal Combustion Residues from Electric Utilities Using Wet Scrubbers for Multi-Pollutant Control

EPA Science Inventory

This report evaluates changes that may occur to coal combustion residues (CCRs) in response to changes in air pollution control technology at coal-fired power plants, which will reduce emissions from the flue gas stack by transferring pollutants to fly ash and other air pollution...

Impacts of Hazardous Air Pollutants Emitted from Phosphate Fertilizer Production Plants on their Ambient Concentration Levels in the Tampa Bay Area

EPA Science Inventory

The concentrations and distribution of Hazardous Air Pollutants (HAPs) metals emitted from four phosphate fertilizer plants in Central Florida, as well as their environmental and health impacts, were assessed. The dominant HAP metals emitted from the stacks of these plants were M...

49 CFR 176.405 - Stowage of charcoal.

Code of Federal Regulations, 2013 CFR

2013-10-01

... bags and offered for transportation on board a vessel in a quantity over 1016 kg (2240 pounds) must be loaded so that the bags are laid horizontally and stacked with space for efficient air circulation. If... repaired bags restowed. (d) Charcoal “screenings” packed in bags must be stowed to provide spaces for air...

49 CFR 176.405 - Stowage of charcoal.

Code of Federal Regulations, 2014 CFR

2014-10-01

... bags and offered for transportation on board a vessel in a quantity over 1016 kg (2240 pounds) must be loaded so that the bags are laid horizontally and stacked with space for efficient air circulation. If... repaired bags restowed. (d) Charcoal “screenings” packed in bags must be stowed to provide spaces for air...

49 CFR 176.405 - Stowage of charcoal.

Code of Federal Regulations, 2012 CFR

2012-10-01

... bags and offered for transportation on board a vessel in a quantity over 1016 kg (2240 pounds) must be loaded so that the bags are laid horizontally and stacked with space for efficient air circulation. If... repaired bags restowed. (d) Charcoal “screenings” packed in bags must be stowed to provide spaces for air...

The interfacial-organized monolayer water film (MWF) induced ``two-step'' aggregation of nanographene: both in stacking and sliding assembly pathways

NASA Astrophysics Data System (ADS)

Lv, Wenping; Wu, Ren'an

2013-03-01

A computational investigation was carried out to understand the aggregation of nanoscale graphene with two typical pathways of stacking assembly and sliding assembly in water. The interfacial-organized monolayer water film (MWF) induced ``two-step'' aggregation of nanographene in both stacking and sliding assembly pathways was reported for the first time. By means of potential mean forces (PMFs) calculation, no energy barrier was observed during the sliding assembly of two graphene nanosheets, while the PMF profiles could be impacted by the contact forms of nanographene and the MWF within the interplate of two graphene nanosheets. To explore the potential physical basis of the ``hindering role'' of self-organized interfacial water, the dynamical and structural properties as well as the status of hydrogen bonds (H-bonds) for interfacial water were investigated. We found that the compact, ordered structure and abundant H-bonds of the MWF could be taken as the fundamental aspects of the ``hindering role'' of interfacial water for the hydrophobic assembly of nanographene. These findings are displaying a potential to further understand the hydrophobic assembly which mostly dominate the behaviors of nanomaterials, proteins etc. in aqueous solutions.A computational investigation was carried out to understand the aggregation of nanoscale graphene with two typical pathways of stacking assembly and sliding assembly in water. The interfacial-organized monolayer water film (MWF) induced ``two-step'' aggregation of nanographene in both stacking and sliding assembly pathways was reported for the first time. By means of potential mean forces (PMFs) calculation, no energy barrier was observed during the sliding assembly of two graphene nanosheets, while the PMF profiles could be impacted by the contact forms of nanographene and the MWF within the interplate of two graphene nanosheets. To explore the potential physical basis of the ``hindering role'' of self-organized interfacial water, the dynamical and structural properties as well as the status of hydrogen bonds (H-bonds) for interfacial water were investigated. We found that the compact, ordered structure and abundant H-bonds of the MWF could be taken as the fundamental aspects of the ``hindering role'' of interfacial water for the hydrophobic assembly of nanographene. These findings are displaying a potential to further understand the hydrophobic assembly which mostly dominate the behaviors of nanomaterials, proteins etc. in aqueous solutions. Electronic supplementary information (ESI) available: The evolution of interaction energy for two graphene nanosheets assembly in stacking (a) and sliding (b) pathway was plotted in Fig. S1. The time evolution of three dimension distance for stacking assembly of two graphene nanosheets with the edge-edge orientation of 45° was plotted in Fig. S2. The initial orientations of graphene nanosheets in three simulations (edge-edge distance in x-direction (dx) was 0.3 nm, but in z-direction (dz) was 0.0 nm, 0.4 nm and 0.7 nm, respectively) were shown in Fig. S3. The snapshots of the evolution of hydration shells during the sliding assembly of nanographene were shown in Fig. S4, with the separation of two graphene nanosheets in z-direction is (a) 0 nm and (b) 0.7 nm, respectively. The process of two graphene nanosheets assembly in stacking pathway was shown in Movie S1 as video. The process of two graphene nanosheets (with a separation of 0.7 nm in normal direction) assembly in sliding pathway was shown in Movie S2 as video. The dynamical evolution of interfacial water during the sliding assembly of nanographene was shown in Movie S3 as video. The process of extruding the monolayer water film (MWF) out of the interplate of two graphene nanosheets was shown in Movie S4 as video. Movie S5 displays that the graphene-water-graphene sandwiched structure was successfully maintained during a 10 ns MD simulation. See DOI: 10.1039/c3nr33447c

6-[6-(Pyridin-2-yl)-1,2,4,5-tetra­zin-3-yl]pyridin-3-amine monohydrate

PubMed Central

Broichhagen, Johannes; Klingl, Yvonne E.; Trauner, Dirk; Mayer, Peter

2016-01-01

The packing of the title compound, C12H9N7·H2O, is dominated by hydrogen bonding and π-stacking. Layers parallel to [010] are established by hydrogen bonds involving all amine donor functions and one of the water donor functions, while the remaining water donor function enables the stacking of the layers along [10-1], which is accompanied by π-stacking. In the molecule, the plane of the central tetra­zine ring forms angles of 5.33 (7) and 19.84 (8)° with the adjacent 3-amine-pyridine and pyridine rings, respectively. PMID:26958397

Full-Scale Hollow Fiber Spacesuit Water Membrane Evaporator Prototype Development and Testing for Advanced Spacesuits

NASA Technical Reports Server (NTRS)

Bue, Grant; Trevino, Luis; Tsioulos, Gus; Mitchell, Keith; Dillon, Paul; Weaver, Gregg

2009-01-01

The spacesuit water membrane evaporator (SWME) is being developed to perform the thermal control function for advanced spacesuits to take advantage of recent advances in micropore membrane technology in providing a robust heat-rejection device that is potentially less sensitive to contamination than is the sublimator. Principles of a sheet membrane SWME design were demonstrated using a prototypic test article that was tested in a vacuum chamber at JSC in July 1999. The Membrana Celgard X50-215 microporous hollow fiber (HoFi) membrane was selected after recent contamination tests as the superior candidate among commercial alternatives for HoFi SWME prototype development. Although a number of design variants were considered, one that grouped the fiber layers into stacks, which were separated by small spaces and packaged into a cylindrical shape, was deemed best for further development. An analysis of test data showed that eight layer stacks of the HoFi sheets that had good exposure on each side of the stack would evaporate water with high efficiency. A design that has 15,000 tubes, with 18 cm of exposed tubes between headers has been built and tested that meets the size, weight, and performance requirements of the SWME. This full-scale prototype consists of 30 stacks, each of which are formed into a chevron shape and separated by spacers and organized into three sectors of ten nested stacks. Testing has been performed to show contamination resistance to the constituents expected to be found in potable water produced by the distillation processes. Other tests showed the sensitivity to surfactants.

Determination of the gaseous hydrogen ductile-brittle transition in copper-nickel alloys

NASA Technical Reports Server (NTRS)

Parr, R. A.; Johnston, M. H.; Davis, J. H.; Oh, T. K.

1985-01-01

A series of copper-nickel alloys were fabricated, notched tensile specimens machined for each alloy, and the specimens tested in 34.5 MPa hydrogen and in air. A notched tensile ratio was determined for each alloy and the hydrogen environment embrittlement (HEE) determined for the alloys of 47.7 weight percent nickel to 73.5 weight percent nickel. Stacking fault probability and stacking fault energies were determined for each alloy using the x ray diffraction line shift and line profiles technique. Hydrogen environment embrittlement was determined to be influenced by stacking fault energies; however, the correlation is believed to be indirect and only partially responsible for the HEE behavior of these alloys.

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

NASA Astrophysics Data System (ADS)

Wu, Z. L.; Wang, X. H.; Teng, F.; Li, X. Z.; Wu, X. M.; Liu, L. T.

2013-12-01

A passive, air-breathing 4-cell micro direct methanol fuel cell (μDMFC) stack is presented featured by a fuel delivery structure for a long-term & stable power supply. The fuel is reserved in a T shape tank and diffuses through the porous diffusion layer to the catalyst at anode. The stack has a maximum power output of 110mW with 3M methanol at room temperature and output a stable power even thought 5% fuel is the remained in reservoir. Its performance decreases less than 3% for 100 hours continuous work. As such, it is believed to be more applicable for powering the wireless sensor nodes.

KSC-2015-1070

NASA Image and Video Library

2015-01-12

Workers conduct a solar array illumination test on the upper stack of the Magnetospheric Multiscale spacecraft, or MMS, in the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. Illumination testing of the lower instrumentation payload stack was completed in December. 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. To learn more about MMS, visit http://www.nasa.gov/mms. Photo credit: NASA/Kim Shiflett

KSC-2015-1073

NASA Image and Video Library

2015-01-12

Workers conduct a solar array illumination test on the upper stack of the Magnetospheric Multiscale spacecraft, or MMS, in the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. Illumination testing of the lower instrumentation payload stack was completed in December. 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. To learn more about MMS, visit http://www.nasa.gov/mms. Photo credit: NASA/Kim Shiflett

KSC-2015-1068

NASA Image and Video Library

2015-01-12

A solar array illumination test is performed on the upper stack of the Magnetospheric Multiscale spacecraft, or MMS, in the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. Illumination testing of the lower instrumentation payload stack was completed in December. 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. To learn more about MMS, visit http://www.nasa.gov/mms. Photo credit: NASA/Kim Shiflett

KSC-2015-1072

NASA Image and Video Library

2015-01-12

A solar array illumination test is performed on the upper stack of the Magnetospheric Multiscale spacecraft, or MMS, in the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. Illumination testing of the lower instrumentation payload stack was completed in December. 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. To learn more about MMS, visit http://www.nasa.gov/mms. Photo credit: NASA/Kim Shiflett

40 CFR 61.44 - Stack sampling.

Code of Federal Regulations, 2013 CFR

2013-07-01

... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium Rocket Motor... within 30 days after samples are taken and before any subsequent rocket motor firing or propellant...

40 CFR 61.44 - Stack sampling.

Code of Federal Regulations, 2014 CFR

2014-07-01

... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium Rocket Motor... within 30 days after samples are taken and before any subsequent rocket motor firing or propellant...

40 CFR 61.44 - Stack sampling.

Code of Federal Regulations, 2012 CFR

2012-07-01

... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium Rocket Motor... within 30 days after samples are taken and before any subsequent rocket motor firing or propellant...

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.

KSC-2014-4341

NASA Image and Video Library

2014-10-29

CAPE CANAVERAL, Fla. – Workers attach a crane to the protective shipping container to prepare to uncover the lower stack, mini-stack number 1, two of the observatories for NASA's Magnetospheric Multiscale Observatory, or MMS. They were delivered to 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

Femtosecond laser ablation of highly oriented pyrolytic graphite: a green route for large-scale production of porous graphene and graphene quantum dots

NASA Astrophysics Data System (ADS)

Russo, Paola; Hu, Anming; Compagnini, Giuseppe; Duley, Walter W.; Zhou, Norman Y.

2014-01-01

Porous graphene (PG) and graphene quantum dots (GQDs) are attracting attention due to their potential applications in photovoltaics, catalysis, and bio-related fields. We present a novel way for mass production of these promising materials. The femtosecond laser ablation of highly oriented pyrolytic graphite (HOPG) is employed for their synthesis. Porous graphene (PG) layers were found to float at the water-air interface, while graphene quantum dots (GQDs) were dispersed in the solution. The sheets consist of one to six stacked layers of spongy graphene, which form an irregular 3D porous structure that displays pores with an average size of 15-20 nm. Several characterization techniques have confirmed the porous nature of the collected layers. The analyses of the aqueous solution confirmed the presence of GQDs with dimensions of about 2-5 nm. It is found that the formation of both PG and GQDs depends on the fs-laser ablation energy. At laser fluences less than 12 J cm-2, no evidence of either PG or GQDs is detected. However, polyynes with six and eight carbon atoms per chain are found in the solution. For laser energies in the 20-30 J cm-2 range, these polyynes disappeared, while PG and GQDs were found at the water-air interface and in the solution, respectively. The origin of these materials can be explained based on the mechanisms for water breakdown and coal gasification. The absence of PG and GQDs, after the laser ablation of HOPG in liquid nitrogen, confirms the proposed mechanisms.Porous graphene (PG) and graphene quantum dots (GQDs) are attracting attention due to their potential applications in photovoltaics, catalysis, and bio-related fields. We present a novel way for mass production of these promising materials. The femtosecond laser ablation of highly oriented pyrolytic graphite (HOPG) is employed for their synthesis. Porous graphene (PG) layers were found to float at the water-air interface, while graphene quantum dots (GQDs) were dispersed in the solution. The sheets consist of one to six stacked layers of spongy graphene, which form an irregular 3D porous structure that displays pores with an average size of 15-20 nm. Several characterization techniques have confirmed the porous nature of the collected layers. The analyses of the aqueous solution confirmed the presence of GQDs with dimensions of about 2-5 nm. It is found that the formation of both PG and GQDs depends on the fs-laser ablation energy. At laser fluences less than 12 J cm-2, no evidence of either PG or GQDs is detected. However, polyynes with six and eight carbon atoms per chain are found in the solution. For laser energies in the 20-30 J cm-2 range, these polyynes disappeared, while PG and GQDs were found at the water-air interface and in the solution, respectively. The origin of these materials can be explained based on the mechanisms for water breakdown and coal gasification. The absence of PG and GQDs, after the laser ablation of HOPG in liquid nitrogen, confirms the proposed mechanisms. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr05572h

Effects of sugar functional groups, hydrophobicity, and fluorination on carbohydrate-DNA stacking interactions in water.

PubMed

Lucas, Ricardo; Peñalver, Pablo; Gómez-Pinto, Irene; Vengut-Climent, Empar; Mtashobya, Lewis; Cousin, Jonathan; Maldonado, Olivia S; Perez, Violaine; Reynes, Virginie; Aviñó, Anna; Eritja, Ramón; González, Carlos; Linclau, Bruno; Morales, Juan C

2014-03-21

Carbohydrate-aromatic interactions are highly relevant for many biological processes. Nevertheless, experimental data in aqueous solution relating structure and energetics for sugar-arene stacking interactions are very scarce. Here, we evaluate how structural variations in a monosaccharide including carboxyl, N-acetyl, fluorine, and methyl groups affect stacking interactions with aromatic DNA bases. We find small differences on stacking interaction among the natural carbohydrates examined. The presence of fluorine atoms within the pyranose ring slightly increases the interaction with the C-G DNA base pair. Carbohydrate hydrophobicity is the most determinant factor. However, gradual increase in hydrophobicity of the carbohydrate does not translate directly into a steady growth in stacking interaction. The energetics correlates better with the amount of apolar surface buried upon sugar stacking on top of the aromatic DNA base pair.

KSC-2009-1723

NASA Image and Video Library

2009-02-19

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, spacecraft awaits a GN2 instrument purge flow test in preparation for launch Feb. 24. The spacecraft sits atop Orbital Sciences' Taurus XL rocket. At right is a portion of the umbilical tower attached to the upper stack. The spacecraft sits atop Orbital Sciences' Taurus XL rocket. At right is a portion of the umbilical tower attached to the upper stack. The spacecraft will collect precise global measurements of carbon dioxide (CO2) in the Earth's atmosphere. Scientists will analyze OCO data to improve our understanding of the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Photo courtesy of Jim Stowers, Orbital Sciences

Graphics-oriented Battlefield Tracking Systems: U.S. Army and Air Force Interoperability

DTIC Science & Technology

2010-12-10

systems. There are hundreds of applications used to control joint air operations, to synchronize land forces, and to develop a common operational...plan and synchronize the employment of 5 combat power (Department of Defense 2010c, II-9). The subsystem that facilitates graphics-oriented...during the battle recounts, “we had so many different assets up in the air . . . they were stacked up on so many different levels” ( Jung 2009

76 FR 24421 - Approval and Promulgation of Air Quality Implementation Plans; New Mexico; Section 110(a)(2...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-02

... approval based on the November 2, 1988, approval of New Mexico's stack height regulations (53 FR 44191), at.... Guy Donaldson, Chief, Air Planning Section (6PD- L), Environmental Protection Agency, 1445 Ross Avenue... Section (6PD-L), Environmental Protection Agency, 1445 Ross Avenue, Suite 1200, Dallas, Texas 75202-2733...

75 FR 65067 - National Emission Standards for Hazardous Air Pollutant Emissions: Hard and Decorative Chromium...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-21

... non-air quality health and environmental impacts) and are commonly referred to as maximum achievable... process, stack, storage, or fugitive emissions point, (D) are design, equipment, work practice, or... combination of the above. CAA section 112(d)(2)(A)-(E). The MACT standard may take the form of a design...

Environmental Assessment for Infrastructure Improvements in the Base Developed Area at Eielson Air Force Base, Alaska

DTIC Science & Technology

2011-03-01

utilizing aqueous ammonia used to control nitrogen oxide and dry flue gas desulfurization used to control sulfur dioxide) will be included as part of...blowers; boiler combustion air and forced draft fans; boiler flue gas ; induced draft fans and stacks; as well as extensions of the plant control

Environmental Assessment for Infrastructure Improvements in the Base Developed Area at Eielson Air Force Base, Alaska

DTIC Science & Technology

2011-03-01

aqueous ammonia used to control nitrogen oxide and dry flue gas desulfurization used to control sulfur dioxide) will be included as part of the...boiler combustion air and forced draft fans; boiler flue gas ; induced draft fans and stacks; as well as extensions of the plant control; electrical

Modeling and optimization of the air system in polymer exchange membrane fuel cell systems

NASA Astrophysics Data System (ADS)

Bao, Cheng; Ouyang, Minggao; Yi, Baolian

Stack and air system are the two most important components in the fuel cell system (FCS). It is meaningful to study their properties and the trade-off between them. In this paper, a modified one-dimensional steady-state analytical fuel cell model is used. The logarithmic mean of the inlet and the outlet oxygen partial pressure is adopted to avoid underestimating the effect of air stoichiometry. And the pressure drop model in the grid-distributed flow field is included in the stack analysis. Combined with the coordinate change preprocessing and analog technique, neural network is used to treat the MAP of compressor and turbine in the air system. Three kinds of air system topologies, the pure screw compressor, serial booster and exhaust expander are analyzed in this article. A real-code genetic algorithm is programmed to obtain the global optimum air stoichiometric ratio and the cathode outlet pressure. It is shown that the serial booster and expander with the help of exhaust recycling, can improve more than 3% in the FCS efficiency comparing to the pure screw compressor. As the net power increases, the optimum cathode outlet pressure keeps rising and the air stoichiometry takes on the concave trajectory. The working zone of the proportional valve is also discussed. This presented work is helpful to the design of the air system in fuel cell system. The steady-state optimum can also be used in the dynamic control.

Simultaneous treatment of SO2 containing stack gases and waste water

NASA Technical Reports Server (NTRS)

Poradek, J. C.; Collins, D. D. (Inventor)

1978-01-01

A process for simultaneously removing sulfur dioxide from stack gases and the like and purifying waste water such as derived from domestic sewage is described. A portion of the gas stream and a portion of the waste water, the latter containing dissolved iron and having an acidic pH, are contacted in a closed loop gas-liquid scrubbing zone to effect absorption of the sulfur dioxide into the waste water. A second portion of the gas stream and a second portion of the waste water are controlled in an open loop gas-liquid scrubbing zone. The second portion of the waste water contains a lesser amount of iron than the first portion of the waste water. Contacting in the openloop scrubbing zone is sufficient to acidify the waste water which is then treated to remove solids originally present.

NASA Non-Flow-Through PEM Fuel Cell System for Aerospace Applications

NASA Technical Reports Server (NTRS)

Araghi, Koorosh R.

2011-01-01

NASA is researching passive NFT Proton Exchange Membrane (PEM) fuel cell technologies for primary fuel cell power plants in air-independent applications. NFT fuel cell power systems have a higher power density than flow through systems due to both reduced parasitic loads and lower system mass and volume. Reactant storage still dominates system mass/volume considerations. NFT fuel cell stack testing has demonstrated equivalent short term performance to flow through stacks. More testing is required to evaluate long-term performance.

KSC-2015-1067

NASA Image and Video Library

2015-01-12

Preparations are underway for illumination testing of the solar panels on the upper stack of the Magnetospheric Multiscale spacecraft, or MMS, in the Astrotech payload processing facility in Titusville, Florida, near Kennedy Space Center. Illumination testing of the lower instrumentation payload stack was completed in December. 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. To learn more about MMS, visit http://www.nasa.gov/mms. Photo credit: NASA/Kim Shiflett

Entropy and biological systems: experimentally-investigated entropy-driven stacking of plant photosynthetic membranes.

PubMed

Jia, Husen; Liggins, John R; Chow, Wah Soon

2014-02-24

According to the Second Law of Thermodynamics, an overall increase of entropy contributes to the driving force for any physicochemical process, but entropy has seldom been investigated in biological systems. Here, for the first time, we apply Isothermal Titration Calorimetry (ITC) to investigate the Mg(2+)-induced spontaneous stacking of photosynthetic membranes isolated from spinach leaves. After subtracting a large endothermic interaction of MgCl₂ with membranes, unrelated to stacking, we demonstrate that the enthalpy change (heat change at constant pressure) is zero or marginally positive or negative. This first direct experimental evidence strongly suggests that an entropy increase significantly drives membrane stacking in this ordered biological structure. Possible mechanisms for the entropy increase include: (i) the attraction between discrete oppositely-charged areas, releasing counterions; (ii) the release of loosely-bound water molecules from the inter-membrane gap; (iii) the increased orientational freedom of previously-aligned water dipoles; and (iv) the lateral rearrangement of membrane components.

Entropy and biological systems: Experimentally-investigated entropy-driven stacking of plant photosynthetic membranes

PubMed Central

Jia, Husen; Liggins, John R.; Chow, Wah Soon

2014-01-01

According to the Second Law of Thermodynamics, an overall increase of entropy contributes to the driving force for any physicochemical process, but entropy has seldom been investigated in biological systems. Here, for the first time, we apply Isothermal Titration Calorimetry (ITC) to investigate the Mg2+-induced spontaneous stacking of photosynthetic membranes isolated from spinach leaves. After subtracting a large endothermic interaction of MgCl2 with membranes, unrelated to stacking, we demonstrate that the enthalpy change (heat change at constant pressure) is zero or marginally positive or negative. This first direct experimental evidence strongly suggests that an entropy increase significantly drives membrane stacking in this ordered biological structure. Possible mechanisms for the entropy increase include: (i) the attraction between discrete oppositely-charged areas, releasing counterions; (ii) the release of loosely-bound water molecules from the inter-membrane gap; (iii) the increased orientational freedom of previously-aligned water dipoles; and (iv) the lateral rearrangement of membrane components. PMID:24561561

The role of the cubic structure in freezing of a supercooled water droplet on an ice substrate

NASA Astrophysics Data System (ADS)

Takahashi, T.; Kobayashi, T.

1983-12-01

The possibility of the formation of a metastable cubic (diamond) structure and its role in freezing of a supercooled water droplet on an ice substrate are discussed in terms of two-dimensional nucleation. The mode of stacking sequence of new layers formed by two-dimensional nucleation is divided into single and multi-nucleation according to the degree of supercooling and to the size of the supercooled droplet. In the case of single nucleation a frozen droplet develops into a complete hexagonal single crystal or an optically single crystal (containing discontinuous stacking faults). In the case of multi-nucleation attention is paid to the size effect and the stacking direction of the nucleus to calculate the waiting time in the nucleation. Then the frozen droplets are crystallographically divided into three categories: completely single crystals, optically single crystals (containing a small cubic structure, i.e. stacking faults) and polycrystals with a misorientation of 70.53° between the c-axes.

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.

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.

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.

International Space Station (ISS)

NASA Image and Video Library

2001-03-01

The Environmental Control and Life Support System (ECLSS) Group of the Flight Projects Directorate at the Marshall Space Flight Center in Huntsville, Alabama, is responsible for designing and building the life support systems that will provide the crew of the International Space Station (ISS) a comfortable environment in which to live and work. This photograph shows the mockup of the the ECLSS to be installed in the Node 3 module of the ISS. From left to right, shower rack, waste management rack, Water Recovery System (WRS) Rack #2, WRS Rack #1, and Oxygen Generation System (OGS) rack are shown. The WRS provides clean water through the reclamation of wastewaters and is comprised of a Urine Processor Assembly (UPA) and a Water Processor Assembly (WPA). The UPA accepts and processes pretreated crewmember urine to allow it to be processed along with other wastewaters in the WPA. The WPA removes free gas, organic, and nonorganic constituents before the water goes through a series of multifiltration beds for further purification. The OGS produces oxygen for breathing air for the crew and laboratory animals, as well as for replacing oxygen loss. The OGS is comprised of a cell stack, which electrolyzes (breaks apart the hydrogen and oxygen molecules) some of the clean water provided by the WRS, and the separators that remove the gases from the water after electrolysis.

The Advantages of Non-Flow-Through Fuel Cell Power Systems for Aerospace Applications

NASA Technical Reports Server (NTRS)

Hoberecht, Mark; Burke, Kenneth; Jakupca, Ian

2011-01-01

NASA has been developing proton-exchange-membrane (PEM) fuel cell power systems for the past decade, as an upgraded technology to the alkaline fuel cells which presently provide power for the Shuttle Orbiter. All fuel cell power systems consist of one or more fuel cell stacks in combination with appropriate balance-of-plant hardware. Traditional PEM fuel cells are characterized as flow-through, in which recirculating reactant streams remove product water from the fuel cell stack. NASA recently embarked on the development of non-flow-through fuel cell systems, in which reactants are dead-ended into the fuel cell stack and product water is removed by internal wicks. This simplifies the fuel cell power system by eliminating the need for pumps to provide reactant circulation, and mechanical water separators to remove the product water from the recirculating reactant streams. By eliminating these mechanical components, the resulting fuel cell power system has lower mass, volume, and parasitic power requirements, along with higher reliability and longer life. These improved non-flow-through fuel cell power systems therefore offer significant advantages for many aerospace applications.

40 CFR 63.7280 - What is the purpose of this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and..., and battery stacks at coke oven batteries. This subpart also establishes requirements to demonstrate...

40 CFR 63.7280 - What is the purpose of this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and..., and battery stacks at coke oven batteries. This subpart also establishes requirements to demonstrate...

40 CFR 63.7280 - What is the purpose of this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and..., and battery stacks at coke oven batteries. This subpart also establishes requirements to demonstrate...

40 CFR 63.7280 - What is the purpose of this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and..., and battery stacks at coke oven batteries. This subpart also establishes requirements to demonstrate...

40 CFR 63.7280 - What is the purpose of this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

...) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery... battery stacks at coke oven batteries. This subpart also establishes requirements to demonstrate initial...

Oxygen separation from air using zirconia solid electrolyte membranes

NASA Technical Reports Server (NTRS)

Suitor, J. W.; Marner, W. J.; Schroeder, J. E.; Losey, R. W.; Ferrall, J. F.

1988-01-01

Air separation using a zirconia solid electrolyte membrane is a possible alternative source of oxygen. The process of zirconia oxygen separation is reviewed, and an oxygen plant concept using such separation is described. Potential cell designs, stack designs, and testing procedures are examined. Fabrication of the materials used in a zirconia module as well as distribution plate design and fabrication are examined.

High-Temperature, Dual-Atmosphere Corrosion of Solid-Oxide Fuel Cell Interconnects

NASA Astrophysics Data System (ADS)

Gannon, Paul; Amendola, Roberta

2012-12-01

High-temperature corrosion of ferritic stainless steel (FSS) surfaces can be accelerated and anomalous when it is simultaneously subjected to different gaseous environments, e.g., when separating fuel (hydrogen) and oxidant (air) streams, in comparison with single-atmosphere exposures, e.g., air only. This so-called "dual-atmosphere" exposure is realized in many energy-conversion systems including turbines, boilers, gasifiers, heat exchangers, and particularly in intermediate temperature (600-800°C) planar solid-oxide fuel cell (SOFC) stacks. It is generally accepted that hydrogen transport through the FSS (plate or tube) and its subsequent integration into the growing air-side surface oxide layer can promote accelerated and anomalous corrosion—relative to single-atmosphere exposure—via defect chemistry changes, such as increased cation vacancy concentrations, decreased oxygen activity, and steam formation within the growing surface oxide layers. Establishment of a continuous and dense surface oxide layer on the fuel side of the FSS can inhibit hydrogen transport and the associated effects on the air side. Minor differences in FSS composition, microstructure, and surface conditions can all have dramatic influences on dual-atmosphere corrosion behaviors. This article reviews high-temperature, dual-atmosphere corrosion phenomena and discusses implications for SOFC stacks, related applications, and future research.

Characterization of polychlorinated dibenzo-p-dioxins and dibenzofurans, dioxin-like polychlorinated biphenyls, and polychlorinated naphthalenes in the environment surrounding secondary copper and aluminum metallurgical facilities in China.

PubMed

Hu, Jicheng; Zheng, Minghui; Liu, Wenbin; Nie, Zhiqiang; Li, Changliang; Liu, Guorui; Xiao, Ke

2014-10-01

Unintentionally produced persistent organic pollutants (UP-POPs) were determined in ambient air from around five secondary non-ferrous metal processing plants in China, to investigate the potential impacts of the emissions of these plants on their surrounding environments. The target compounds were polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), and polychlorinated naphthalenes (PCNs). The PCDD/F, dl-PCB, and PCN concentrations in the ambient air downwind of the plants were 4.70-178, 8.23-7520 and 152-4190 pg/m(3), respectively, and the concentrations upwind of the plants were lower. Clear correlations were found between ambient air and stack gas concentrations of the PCDD/Fs, dl-PCBs, and PCNs among the five plants, respectively. Furthermore, the UP-POPs homolog and congener patterns in the ambient air were similar to the patterns in the stack gas samples. These results indicate that UP-POPs emissions from the plants investigated have obvious impacts on the environments surrounding the plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Solid oxide fuel cell matrix and modules

DOEpatents

Riley, Brian

1990-01-01

Porous refractory ceramic blocks arranged in an abutting, stacked configuration and forming a three dimensional array provide a support structure and coupling means for a plurality of solid oxide fuel cells (SOFCs). Each of the blocks includes a square center channel which forms a vertical shaft when the blocks are arranged in a stacked array. Positioned within the channel is a SOFC unit cell such that a plurality of such SOFC units disposed within a vertical shaft form a string of SOFC units coupled in series. A first pair of facing inner walls of each of the blocks each include an interconnecting channel hole cut horizontally and vertically into the block walls to form gas exit channels. A second pair of facing lateral walls of each block further include a pair of inner half circular grooves which form sleeves to accommodate anode fuel and cathode air tubes. The stack of ceramic blocks is self-supporting, with a plurality of such stacked arrays forming a matrix enclosed in an insulating refractory brick structure having an outer steel layer. The necessary connections for air, fuel, burnt gas, and anode and cathode connections are provided through the brick and steel outer shell. The ceramic blocks are so designed with respect to the strings of modules that by simple and logical design the strings could be replaced by hot reloading if one should fail. The hot reloading concept has not been included in any previous designs.

Water-Floating Giant Nanosheets from Helical Peptide Pentamers

NASA Astrophysics Data System (ADS)

Lee, Jaehun; Nam, Ki Tae

One of the important challenges in the development of protein-mimetic materials is to understand the sequence specific assembly behavior and the dynamic folding change. Conventional strategies to construct two dimensional nanostructures from the peptides have been limited to beta-sheet forming sequences in use of basic building blocks because of their natural tendency to form sheet like aggregations. Here we identified a new peptide sequence, YFCFY that can form dimers by the disulfide bridge, fold into helix and assemble into macroscopic flat sheet at the air/water interface. Because of large driving force for two dimensional assembly and high elastic modulus of the resulting sheet, the peptide assembly induces the flattening of initially round water droplet. Additionally, we found that stabilization of helix by the dimerization is a key determinant for maintaining macroscopic flatness over a few tens centimeter even with a uniform thickness below 10 nm. Furthermore, the capability to transfer 2D film from water droplet to other substrates allows for the multiple stacking of 2D peptide nanostructure, suggesting possible applications in the biomimetic catalysts, biosensor and 2D related electronic devices. This work was supported by Samsung Research Funding Center of Samsung Electronics under Project Number SRFC-MA1401-01.

International Space Station (ISS)

NASA Image and Video Library

2000-09-01

The Environmental Control and Life Support System (ECLSS) Group of the Flight Projects Directorate at the Marshall Space Flight Center (MSFC) in Huntsville, Alabama, is responsible for designing and building the life support systems that will provide the crew of the International Space Station (ISS) a comfortable environment in which to live and work. This is a close-up view of ECLSS Oxygen Generation System (OGS) rack. The ECLSS Group at the MSFC oversees the development of the OGS, which produces oxygen for breathing air for the crew and laboratory animals, as well as for replacing oxygen lost due to experiment use, airlock depressurization, module leakage, and carbon dioxide venting. The OGS consists primarily of the Oxygen Generator Assembly (OGA), provided by the prime contractor, the Hamilton Sundstrand Space Systems, International (HSSSI) in Windsor Locks, Cornecticut and a Power Supply Module (PSM), supplied by the MSFC. The OGA is comprised of a cell stack that electrolyzes (breaks apart the hydrogen and oxygen molecules) some of the clean water provided by the Water Recovery System and the separators that remove the gases from water after electrolysis. The PSM provides the high power to the OGA needed to electrolyze the water.

KSC-2011-1459

NASA Image and Video Library

2011-02-15

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 576-E at Vandenberg Air Force Base in California, Orbital Sciences workers monitor NASA's Glory upper stack as a crane lifts it from a stationary rail for attachment to the Taurus XL rocket's Stage 0. The upper stack consists of Stages 1, 2 and 3 of the Taurus as well as the encapsulated Glory spacecraft. Workers put the non-flight environmental shield over the fairing prior to assembly. The Orbital Sciences Taurus XL rocket will launch Glory into low Earth orbit. Once Glory reaches orbit, it will collect data on the properties of aerosols and black carbon. It also will help scientists understand how the sun's irradiance affects Earth's climate. Launch is scheduled for 5:09 a.m. EST Feb. 23. For information, visit www.nasa.gov/glory. Photo credit: NASA/Randy Beaudoin, VAFB

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

MacDonald, R.; Kelley, D.E.

In 1998, when Sunlaw Energy Corporation needed to retrofit their two natural gas fired power plants to meet new emissions requirements that were soon to come into place, they looked at existing technologies and found them either economically or environmentally undesirable. With the help of General Electric they developed a program of water injection that was capable of reducing the NO{sub x} emissions to 25 ppm. This, however, was not low enough to meet coming regulations. Sunlaw concluded that the best option for pollution control was to invert their own system. A partnership was formed between Sunlaw and Advanced Catalystmore » Systems, a catalyst development and manufacturing firm. The result of their efforts was Goal Line Environmental Technologies and the SCONOx catalytic absorption system. The newest SCONOx system, commissioned at Sunlaw's Federal cogeneration plant in December 1996, treats the exhaust of a GELM2500 gas turbine. Combined with water injection, it has reduced NO{sub x} emission from 160 ppm down to 1--2 ppm. Carbon monoxide emissions are virtually eliminated, with stack readings less than ambient levels. The SCONOx system uses single catalyst for both CO and NO{sub x} control. It oxidizes CO to CO{sub 2} and NO to NO{sub 2}, and the NO{sub 2} is then absorbed onto the surface of the catalyst. Just as a sponge absorbs water and must be periodically regenerated, the catalyst must be regenerated. This is accomplished by passing a dilute hydrogen gas across the surface of the catalyst in the absence of oxygen. Nitrogen oxygen are broken down into nitrogen and water, and this is exhausted up the stack instead of NO{sub x}. The SCONOx system is a breakthrough in CO and NO{sub x} control technology that makes it possible to have clean air without the use of ammonia or other hazardous materials. It is truly an environmentally friendly NO{sub x} system.« less

CrossTalk. The Journal of Defense Software Engineering. Volume 16, Number 11, November 2003

DTIC Science & Technology

2003-11-01

memory area, and stack pointer. These systems are classified as preemptive or nonpreemptive depending on whether they can preempt an existing task or not...of charge. The Software Technology Support Center was established at Ogden Air Logistics Center (AFMC) by Headquarters U.S. Air Force to help Air...device. A script file could be a list of commands for a command interpreter such as a batch file [15]. A communications port consists of a queue to hold

Large volume flow-through scintillating detector

DOEpatents

Gritzo, Russ E.; Fowler, Malcolm M.

1995-01-01

A large volume flow through radiation detector for use in large air flow situations such as incinerator stacks or building air systems comprises a plurality of flat plates made of a scintillating material arranged parallel to the air flow. Each scintillating plate has a light guide attached which transfers light generated inside the scintillating plate to an associated photomultiplier tube. The output of the photomultiplier tubes are connected to electronics which can record any radiation and provide an alarm if appropriate for the application.

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.

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

High specific power, direct methanol fuel cell stack

DOEpatents

Ramsey, John C [Los Alamos, NM; Wilson, Mahlon S [Los Alamos, NM

2007-05-08

The present invention is a fuel cell stack including at least one direct methanol fuel cell. A cathode manifold is used to convey ambient air to each fuel cell, and an anode manifold is used to convey liquid methanol fuel to each fuel cell. Tie-bolt penetrations and tie-bolts are spaced evenly around the perimeter to hold the fuel cell stack together. Each fuel cell uses two graphite-based plates. One plate includes a cathode active area that is defined by serpentine channels connecting the inlet manifold with an integral flow restrictor to the outlet manifold. The other plate includes an anode active area defined by serpentine channels connecting the inlet and outlet of the anode manifold. Located between the two plates is the fuel cell active region.

Solid oxide fuel cell matrix and modules

DOEpatents

Riley, B.

1988-04-22

Porous refractory ceramic blocks arranged in an abutting, stacked configuration and forming a three dimensional array provide a support structure and coupling means for a plurality of solid oxide fuel cells (SOFCs). The stack of ceramic blocks is self-supporting, with a plurality of such stacked arrays forming a matrix enclosed in an insulating refractory brick structure having an outer steel layer. The necessary connections for air, fuel, burnt gas, and anode and cathode connections are provided through the brick and steel outer shell. The ceramic blocks are so designed with respect to the strings of modules that by simple and logical design the strings could be replaced by hot reloading if one should fail. The hot reloading concept has not been included in any previous designs. 11 figs.

Permanent-magnet-less synchronous reluctance system

DOEpatents

Hsu, John S

2012-09-11

A permanent magnet-less synchronous system includes a stator that generates a magnetic revolving field when sourced by an alternating current. An uncluttered rotor is disposed within the magnetic revolving field and spaced apart from the stator to form an air gap relative to an axis of rotation. The rotor includes a plurality of rotor pole stacks having an inner periphery biased by single polarity of a north-pole field and a south-pole field, respectively. The outer periphery of each of the rotor pole stacks are biased by an alternating polarity.

Implementation of Stack Height Regulations - Exceptions from Restrictions on Credit for Merged Stacks

EPA Pesticide Factsheets

This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

Novel ferrocene-anchored ZnO nanoparticle/carbon nanotube assembly for glucose oxidase wiring: application to a glucose/air fuel cell.

PubMed

Haddad, Raoudha; Mattei, Jean-Gabriel; Thery, Jessica; Auger, Aurélien

2015-06-28

Glucose oxidase (GOx) is immobilized on ZnO nanoparticle-modified electrodes. The immobilized glucose oxidase shows efficient mediated electron transfer with ZnO nanoparticles to which the ferrocenyl moiety is π-stacked into a supramolecular architecture. The constructed ZnO-Fc/CNT modified electrode exhibits high ferrocene surface coverage, preventing any leakage of the π-stacked ferrocene from the newly described ZnO hybrid nanoparticles. The use of the new architecture of ZnO supported electron mediators to shuttle electrons from the redox centre of the enzyme to the surface of the working electrode can effectively bring about successful glucose oxidation. These modified electrodes evaluated as a highly efficient architecture provide a catalytic current for glucose oxidation and are integrated in a specially designed glucose/air fuel cell prototype using a conventional platinum-carbon (Pt/C) cathode at physiological pH (7.0). The obtained architecture leads to a peak power density of 53 μW cm(-2) at 300 mV for the Nafion® based biofuel cell under "air breathing" conditions at room temperature.

Solar-Powered Cooler and Heater for an Automobile Interior

NASA Technical Reports Server (NTRS)

Howard, Richard T.

2006-01-01

The apparatus would include a solar photovoltaic panel mounted on the roof and a panellike assembly mounted in a window opening. The window-mounted assembly would include a stack of thermoelectric devices sandwiched between two heat sinks. A fan would circulate interior air over one heat sink. Another fan would circulate exterior air over the other heat sink. The fans and the thermoelectric devices would be powered by the solar photovoltaic panel. By means of a double-pole, double-throw switch, the panel voltage fed to the thermoelectric stack would be set to the desired polarity: For cooling operation, the chosen polarity would be one in which the thermoelectric devices transport heat from the inside heat sink to the outside one; for heating operation, the opposite polarity would be chosen. Because thermoelectric devices are more efficient in heating than in cooling, this apparatus would be more effective as a heater than as a cooler. However, if the apparatus were to include means to circulate air between the outside and the inside without opening the windows, then its effectiveness as a cooler in a hot, sunny location would be increased.

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.

40 CFR 63.9652 - What definitions apply to this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

... cooler vent stack and gravity conveyor gallery vents designed to remove heat and water vapor from the... traveling grate, a rotary kiln, and an annular cooler. The grate kiln indurating furnace begins at the point... the hardened pellets exit the cooler. The atmospheric pellet cooler vent stack is not included as part...

40 CFR 63.9652 - What definitions apply to this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

... cooler vent stack and gravity conveyor gallery vents designed to remove heat and water vapor from the... traveling grate, a rotary kiln, and an annular cooler. The grate kiln indurating furnace begins at the point... the hardened pellets exit the cooler. The atmospheric pellet cooler vent stack is not included as part...

40 CFR 63.9652 - What definitions apply to this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... cooler vent stack and gravity conveyor gallery vents designed to remove heat and water vapor from the... traveling grate, a rotary kiln, and an annular cooler. The grate kiln indurating furnace begins at the point... the hardened pellets exit the cooler. The atmospheric pellet cooler vent stack is not included as part...

40 CFR 63.9652 - What definitions apply to this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

... cooler vent stack and gravity conveyor gallery vents designed to remove heat and water vapor from the... traveling grate, a rotary kiln, and an annular cooler. The grate kiln indurating furnace begins at the point... the hardened pellets exit the cooler. The atmospheric pellet cooler vent stack is not included as part...

40 CFR 63.9652 - What definitions apply to this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

... cooler vent stack and gravity conveyor gallery vents designed to remove heat and water vapor from the... traveling grate, a rotary kiln, and an annular cooler. The grate kiln indurating furnace begins at the point... the hardened pellets exit the cooler. The atmospheric pellet cooler vent stack is not included as part...

Determining the Source of Water Vapor in a Cerium Oxide Electrochemical Oxygen Separator to Achieve Aviator Grade Oxygen

NASA Technical Reports Server (NTRS)

Graf, John; Taylor, Dale; Martinez, James

2014-01-01

More than a metric ton of water is transported to the International Space Station (ISS) each year to provide breathing oxygen for the astronauts. Water is a safe and compact form of stored oxygen. The water is electrolyzed on ISS and ambient pressure oxygen is delivered to the cabin. A much smaller amount of oxygen is used each year in spacesuits to conduct Extra Vehicular Activities (EVAs). Space suits need high pressure (>1000 psia) high purity oxygen (must meet Aviator Breathing Oxygen "ABO" specifications, >99.5% O2). The water / water electrolysis system cannot directly provide high pressure, high purity oxygen, so oxygen for EVAs is transported to ISS in high pressure gas tanks. The tanks are relatively large and heavy, and the majority of the system launch weight is for the tanks and not the oxygen. Extracting high purity oxygen from cabin air and mechanically compressing the oxygen might enable on-board production of EVA grade oxygen using the existing water / water electrolysis system. This capability might also benefit human spaceflight missions, where oxygen for EVAs could be stored in the form of water, and converted into high pressure oxygen on-demand. Cerium oxide solid electrolyte-based ion transport membranes have been shown to separate oxygen from air, and a supported monolithic wafer form of the CeO2 electrolyte membrane has been shown to deliver oxygen at pressures greater than 300 psia. These supported monolithic wafers can withstand high pressure differentials even though the membrane is very thin, because the ion transport membrane is supported on both sides (Fig 1). The monolithic supported wafers have six distinct layers, each with matched coefficients of thermal expansion. The wafers are assembled into a cell stack which allows easy air flow across the wafers, uniform current distribution, and uniform current density (Fig 2). The oxygen separation is reported to be "infinitely selective" to oxygen [1] with reported purity of 99.99% [2]. Combined with a mechanical compressor, a Solid Electrolyte Oxygen Separator (SEOS) should be capable of producing ABO grade oxygen at pressures >2400 psia, on the space station. Feasibility tests using a SEOS integrated with a mechanical compressor identified an unexpected contaminant in the oxygen: water vapour was found in the oxygen product, sometimes at concentrations higher than 40 ppm (the ABO limit for water vapour is 7 ppm). If solid electrolyte membranes are really "infinitely selective" to oxygen as they are reported to be, where did the water come from? If water is getting into the oxygen, what other contaminants might get into the oxygen? Microscopic analyses of wafers, welds, and oxygen delivery tubes were performed in an attempt to find the source of the water vapour contamination. Hot and cold pressure decay tests were performed. Measurements of water vapour as a function of O2 delivery rate, O2 delivery pressure, and process air humidity levels were the most instructive in finding the source of water contamination (Fig 3). Water contamination was directly affected by oxygen delivery rate (doubling the oxygen production rate cut the water level in half). Water was affected by process air humidity levels and delivery pressure in a way that indicates the water was diffusing into the oxygen delivery system.

Hollow Fiber Spacesuit Water Membrane Evaporator Development and Testing for Advanced Spacesuits

NASA Technical Reports Server (NTRS)

Bue, Grant C.; Trevino, Luis A.; Tsioulos, Gus; Settles, Joseph; Colunga, Aaron; Vogel, Matthew; Vonau, Walt

2010-01-01

The spacesuit water membrane evaporator (SWME) is being developed to perform the thermal control function for advanced spacesuits to take advantage of recent advances in micropore membrane technology in providing a robust heat-rejection device that is potentially less sensitive to contamination than is the sublimator. Principles of a sheet membrane SWME design were demonstrated using a prototypic test article that was tested in a vacuum chamber at JSC in July 1999. The Membrana Celgard X50-215 microporous hollow fiber (HoFi) membrane was selected after recent contamination tests as the most suitable candidate among commercial alternatives for HoFi SWME prototype development. A design that grouped the fiber layers into stacks, which were separated by small spaces and packaged into a cylindrical shape, was developed into a full-scale prototype consisting 14,300 tube bundled into 30 stacks, each of which are formed into a chevron shape and separated by spacers and organized into three sectors of ten nested stacks. Vacuum chamber testing has been performed characterize heat rejection as a function of inlet water temperature and water vapor backpressure and to show contamination resistance to the constituents expected to be found in potable water produced by the distillation processes. Other tests showed the tolerance to freezing and suitability to reject heat in a Mars pressure environment.

Modeling two-phase flow in three-dimensional complex flow-fields of proton exchange membrane fuel cells

NASA Astrophysics Data System (ADS)

Kim, Jinyong; Luo, Gang; Wang, Chao-Yang

2017-10-01

3D fine-mesh flow-fields recently developed by Toyota Mirai improved water management and mass transport in proton exchange membrane (PEM) fuel cell stacks, suggesting their potential value for robust and high-power PEM fuel cell stack performance. In such complex flow-fields, Forchheimer's inertial effect is dominant at high current density. In this work, a two-phase flow model of 3D complex flow-fields of PEMFCs is developed by accounting for Forchheimer's inertial effect, for the first time, to elucidate the underlying mechanism of liquid water behavior and mass transport inside 3D complex flow-fields and their adjacent gas diffusion layers (GDL). It is found that Forchheimer's inertial effect enhances liquid water removal from flow-fields and adds additional flow resistance around baffles, which improves interfacial liquid water and mass transport. As a result, substantial improvements in high current density cell performance and operational stability are expected in PEMFCs with 3D complex flow-fields, compared to PEMFCs with conventional flow-fields. Higher current density operation required to further reduce PEMFC stack cost per kW in the future will necessitate optimizing complex flow-field designs using the present model, in order to efficiently remove a large amount of product water and hence minimize the mass transport voltage loss.

Hollow Fiber Flight Prototype Spacesuit Water Membrane Evaporator Design and Testing

NASA Technical Reports Server (NTRS)

Bue, Grant; Vogel, Matt; Makinen, Janice; Tsioulos, Gus

2010-01-01

The spacesuit water membrane evaporator (SWME) is being developed to perform thermal control for advanced spacesuits and to take advantage of recent advances in micropore membrane technology. This results in a robust heat-rejection device that is potentially less sensitive to contamination than is the sublimator. The Membrana Celgard X50-215 microporous hollow-fiber (HoFi) membrane was selected after recent extensive testing as the most suitable candidate among commercial alternatives for continued SWME prototype development. The current design was based on a previous design that grouped the fiber layers into stacks, which were separated by small spaces and packaged into a cylindrical shape. This was developed into a full-scale prototype consisting of 14,300 tube bundled into 30 stacks, each of which is formed into a chevron shape and separated by spacers and organized into three sectors of 10 nested stacks. The new design replaced metal components with plastic ones, and has a custom built flight like backpressure valve mounted on the side of the SWME housing to reduce backpressure when fully open. The spacers that provided separation of the chevron fiber stacks were eliminated. Vacuum chamber testing showed improved heat rejection as a function of inlet water temperature and water vapor backpressure compared with the previous design. Other tests pushed the limits of tolerance to freezing and showed suitability to reject heat in a Mars pressure environment with and without a sweep gas. Tolerance to contamination by constituents expected to be found in potable water produced by distillation processes was tested in a conventional way by allowing constituents to accumulate in the coolant as evaporation occurs. For this purpose, the SWME cartridge has endured an equivalent of 30 EVAs exposure and demonstrated minimal performance decline.

Air-Sea Interaction in the Gulf of Tehuantepec

NASA Astrophysics Data System (ADS)

Khelif, D.; Friehe, C. A.; Melville, W. K.

2007-05-01

Measurements of meteorological fields and turbulence were made during gap wind events in the Gulf of Tehuantepec using the NSF C-130 aircraft. The flight patterns started at the shore and progressed to approximately 300km offshore with low-level (30m) tracks, stacks and soundings. Parameterizations of the wind stress, sensible and latent heat fluxes were obtained from approximately 700 5 km low-level tracks. Structure of the marine boundary layer as it evolved off-shore was obtained with stack patterns, aircraft soundings and deployment of dropsondes. The air-sea fluxes approximately follow previous parameterizations with some evidence of the drag coefficient leveling out at about 20 meters/sec with the latent heat flux slightly increasing. The boundary layer starts at shore as a gap wind low-level jet, thins as the jet expands out over the gulf, exhibits a hydraulic jump, and then increases due to turbulent mixing.

Stack air-breathing membraneless glucose microfluidic biofuel cell

NASA Astrophysics Data System (ADS)

Galindo-de-la-Rosa, J.; Moreno-Zuria, A.; Vallejo-Becerra, V.; Arjona, N.; Guerra-Balcázar, M.; Ledesma-García, J.; Arriaga, L. G.

2016-11-01

A novel stacked microfluidic fuel cell design comprising re-utilization of the anodic and cathodic solutions on the secondary cell is presented. This membraneless microfluidic fuel cell employs porous flow-through electrodes in a “V”-shape cell architecture. Enzymatic bioanodic arrays based on glucose oxidase were prepared by immobilizing the enzyme onto Toray carbon paper electrodes using tetrabutylammonium bromide, Nafion and glutaraldehyde. These electrodes were characterized through the scanning electrochemical microscope technique, evidencing a good electrochemical response due to the electronic transference observed with the presence of glucose over the entire of the electrode. Moreover, the evaluation of this microfluidic fuel cell with an air-breathing system in a double-cell mode showed a performance of 0.8951 mWcm-2 in a series connection (2.2822mAcm-2, 1.3607V), and 0.8427 mWcm-2 in a parallel connection (3.5786mAcm-2, 0.8164V).

KSC-2009-1724

NASA Image and Video Library

2009-02-19

VANDENBERG AIR FORCE BASE, Calif. -- With the fairing door off, Orbital Sciences' Glenn Weigle and Brett Gladish take the GN2 flow reading on NASA's Orbiting Carbon Observatory, or OCO, spacecraft on Launch Complex 576-E at Vandenberg Air Force Base in California. The encapsulated OCO tops Orbital Sciences' Taurus XL rocket, which is scheduled to launch Feb. 24. The spacecraft sits atop Orbital Sciences' Taurus XL rocket. At right is a portion of the umbilical tower attached to the upper stack. The spacecraft sits atop Orbital Sciences' Taurus XL rocket. At right is a portion of the umbilical tower attached to the upper stack. The spacecraft will collect precise global measurements of carbon dioxide (CO2) in the Earth's atmosphere. Scientists will analyze OCO data to improve our understanding of the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Photo courtesy of Jim Stowers, Orbital Sciences

Modeling and Qualification of a Modified Emission Unit for Radioactive Air Emissions Stack Sampling Compliance.

PubMed

Barnett, J Matthew; Yu, Xiao-Ying; Recknagle, Kurtis P; Glissmeyer, John A

2016-11-01

A planned laboratory space and exhaust system modification to the Pacific Northwest National Laboratory Material Science and Technology Building indicated that a new evaluation of the mixing at the air sampling system location would be required for compliance to ANSI/HPS N13.1-2011. The modified exhaust system would add a third fan, thereby increasing the overall exhaust rate out the stack, thus voiding the previous mixing study. Prior to modifying the radioactive air emissions exhaust system, a three-dimensional computational fluid dynamics computer model was used to evaluate the mixing at the sampling system location. Modeling of the original three-fan system indicated that not all mixing criteria could be met. A second modeling effort was conducted with the addition of an air blender downstream of the confluence of the three fans, which then showed satisfactory mixing results. The final installation included an air blender, and the exhaust system underwent full-scale tests to verify velocity, cyclonic flow, gas, and particulate uniformity. The modeling results and those of the full-scale tests show agreement between each of the evaluated criteria. The use of a computational fluid dynamics code was an effective aid in the design process and allowed the sampling system to remain in its original location while still meeting the requirements for sampling at a well mixed location.

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.

A 1 kWel thermoelectric stack for geothermal power generation - Modeling and geometrical optimization

NASA Astrophysics Data System (ADS)

Suter, C.; Jovanovic, Z.; Steinfeld, A.

2012-06-01

A thermoelectric stack composed of arrays of Bi-Te alloy thermoelectric converter (TEC) modules is considered for geothermal heat conversion. The TEC modules consist of Al2O3 plates with surface 30×30 mm2 and 127 p-type (Bi0.2Sb0.8)2Te3 and n-type Bi2(Te0.96Se0.04)3 thermoelement pairs, each having a cross-section of 1.05×1.05 mm2, and with a figure-of-merit of 1 and a heat-to-electricity conversion efficiency of ˜5%. A heat transfer model is formulated to couple conduction in the thermoelements with convection between the Al2O3 plates and the water flow in counter-flow channel configuration. The calculated open-circuit voltages are compared to those resulting from the mean temperature differences across the TEC modules computed by CFD. The investigated parameters are: hot water inlet and outlet temperatures (373 - 413 K and 323 - 363 K, respectively), stack length (300 - 1500 mm), thermoelement length (1 - 4 mm) and hot channel heights (0.2 - 2 mm). The heat transfer model is then applied to optimize a 1 kWel stack with hot water inlet at 393 K and outlet at 353 K for either maximum heat-to-electricity conversion efficiency of 2.9% or minimum size of 0.0044 m3.

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

M. L. Abbott; K. N. Keck; R. E. Schindler

This screening level risk assessment evaluates potential adverse human health and ecological impacts resulting from continued operations of the calciner at the New Waste Calcining Facility (NWCF) at the Idaho Nuclear Technology and Engineering Center (INTEC), Idaho National Engineering and Environmental Laboratory (INEEL). The assessment was conducted in accordance with the Environmental Protection Agency (EPA) report, Guidance for Performing Screening Level Risk Analyses at Combustion Facilities Burning Hazardous Waste. This screening guidance is intended to give a conservative estimate of the potential risks to determine whether a more refined assessment is warranted. The NWCF uses a fluidized-bed combustor to solidifymore » (calcine) liquid radioactive mixed waste from the INTEC Tank Farm facility. Calciner off volatilized metal species, trace organic compounds, and low-levels of radionuclides. Conservative stack emission rates were calculated based on maximum waste solution feed samples, conservative assumptions for off gas partitioning of metals and organics, stack gas sampling for mercury, and conservative measurements of contaminant removal (decontamination factors) in the off gas treatment system. Stack emissions were modeled using the ISC3 air dispersion model to predict maximum particulate and vapor air concentrations and ground deposition rates. Results demonstrate that NWCF emissions calculated from best-available process knowledge would result in maximum onsite and offsite health and ecological impacts that are less then EPA-established criteria for operation of a combustion facility.« less

The Legacy of Arsenic Contamination from Giant Mine, Northern Canada: An Assessment of Impacts Based on Lake Water and Lake Sediment Core Analysis

NASA Astrophysics Data System (ADS)

Blais, J. M.; Korosi, J.

2016-12-01

The Giant Mine, which operated between 1948 and 2004 and located near the City of Yellowknife (Northwest Territories, Canada), has left a legacy of arsenic, antimony, and mercury contamination extending to the present day. Over 20,000 tonnes of arsenic trioxide dust was released from roaster stack emissions during its first 10 years of operations, leading to a significant contamination of the surrounding landscape. Here we present a summary of impacts by the recent contamination from Giant Mine on the surrounding region. A survey we conducted of 25 lakes of the region in 2010 revealed that most lake water within a 15 km radius of the roaster stack had arsenic concentrations in water > 10 mg/L, the standard for drinking water, with concentrations declining exponentially with increasing distance from the roaster stack. Sediment cores from lakes were collected near the Giant Mine roaster stack and radiometrically dated by 137Cs and excess 210Pb. Arsenic concentrations in these sediments increased by 1700% during the 1950s and 60s, consistent with the history of arsenic releases from roaster emissions. Correspondingly, pelagic diatoms and cladocerans were extirpated from one lake during this period, based on microfossil analysis of lake sediment deposits. Sediment core analysis further showed that this lake ecosystem has not recovered, even ten years after closure of the mine. Likely causes for the lack of recent recovery are explored with the use of sediment toxicity bioassays, using a novel paleo-ecotoxicological approach of using toxicity assessments of radiometrically dated lake sediment horizons.

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

Thin film battery/fuel cell power generating system. Final report of the continuation contract (Tasks 1-4), April 1, 1978-March 31, 1980

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

Not Available

1980-06-30

Research on the design, development, and testing of a high-temperature solid electrolyte (HTSOE) fuel cell is described in detail. Task 1 involves the development and refinement of fabrication processes for the porous support tube, fuel electrode, solid electrolyte, air electrode, and interconnection. Task 2 includes the life testing of cell components and the stack; task 3 involves the stack performance evaluation; task 4 includes demonstrating the reproducibility of 10 watt stacks. A cost, design and benefit study to evaluate the nature and worth of an industrial cogeneration application of the HTSOE fuel cell is underway. Here, promisng applications are nowmore » being considered, from which a single application has been selected as a basis for the study - an integrated aluminum production facility. (WHK)« less

Analysis of ambient SO 2 concentrations and winds in the complex surroundings of a thermal power plant

NASA Astrophysics Data System (ADS)

Mlakar, P.

2004-11-01

SO2 pollution is still a significant problem in Slovenia, especially around large thermal power plants (TPPs), like the one at Šoštanj. The Šoštanj TPP is the exclusive source of SO2 in the area and is therefore a perfect example for air pollution studies. In order to understand air pollution around the Šoštanj TPP in detail, some analyses of emissions and ambient concentrations of SO2 at six automated monitoring stations in the surroundings of the TPP were made. The data base from 1991 to 1993 was used when there were no desulfurisation plants in operation. Statistical analyses of the influence of the emissions from the three TPP stacks at different measuring points were made. The analyses prove that the smallest stack (100 m) mainly pollutes villages and towns near the TPP within a radius of a few kilometres. The medium stack's (150 m) influence is noticed at shorter as well as at longer distances up to more than ten kilometres. The highest stack (230 m) pollutes mainly at longer distances, where the plume reaches the higher hills. Detailed analyses of ambient SO2 concentrations were made. They show the temporal and spatial distribution of different classes of SO2 concentrations from very low to alarming values. These analyses show that pollution patterns at a particular station remain the same if observed on a yearly basis, but can vary very much if observed on a monthly basis, mainly because of different weather patterns. Therefore the winds in the basin (as the most important feature influencing air pollution dispersion) were further analysed in detail to find clusters of similar patterns. For cluster analysis of ground-level winds patterns in the basin around the Šoštanj Thermal Power Plant, the Kohonen neural network and Leaders' method were used. Furthermore, the dependence of ambient SO2 concentrations on the clusters obtained was analysed. The results proved that effective cluster analysis can be a useful tool for compressing a huge wind data base in order to find the correlation between winds and pollutant concentrations. The analyses made provide a better insight into air pollution over complex terrain.

Role of stacking disorder in ice nucleation

NASA Astrophysics Data System (ADS)

Lupi, Laura; Hudait, Arpa; Peters, Baron; Grünwald, Michael; Gotchy Mullen, Ryan; Nguyen, Andrew H.; Molinero, Valeria

2017-11-01

The freezing of water affects the processes that determine Earth’s climate. Therefore, accurate weather and climate forecasts hinge on good predictions of ice nucleation rates. Such rate predictions are based on extrapolations using classical nucleation theory, which assumes that the structure of nanometre-sized ice crystallites corresponds to that of hexagonal ice, the thermodynamically stable form of bulk ice. However, simulations with various water models find that ice nucleated and grown under atmospheric temperatures is at all sizes stacking-disordered, consisting of random sequences of cubic and hexagonal ice layers. This implies that stacking-disordered ice crystallites either are more stable than hexagonal ice crystallites or form because of non-equilibrium dynamical effects. Both scenarios challenge central tenets of classical nucleation theory. Here we use rare-event sampling and free energy calculations with the mW water model to show that the entropy of mixing cubic and hexagonal layers makes stacking-disordered ice the stable phase for crystallites up to a size of at least 100,000 molecules. We find that stacking-disordered critical crystallites at 230 kelvin are about 14 kilojoules per mole of crystallite more stable than hexagonal crystallites, making their ice nucleation rates more than three orders of magnitude higher than predicted by classical nucleation theory. This effect on nucleation rates is temperature dependent, being the most pronounced at the warmest conditions, and should affect the modelling of cloud formation and ice particle numbers, which are very sensitive to the temperature dependence of ice nucleation rates. We conclude that classical nucleation theory needs to be corrected to include the dependence of the crystallization driving force on the size of the ice crystallite when interpreting and extrapolating ice nucleation rates from experimental laboratory conditions to the temperatures that occur in clouds.

Role of stacking disorder in ice nucleation.

PubMed

Lupi, Laura; Hudait, Arpa; Peters, Baron; Grünwald, Michael; Gotchy Mullen, Ryan; Nguyen, Andrew H; Molinero, Valeria

2017-11-08

The freezing of water affects the processes that determine Earth's climate. Therefore, accurate weather and climate forecasts hinge on good predictions of ice nucleation rates. Such rate predictions are based on extrapolations using classical nucleation theory, which assumes that the structure of nanometre-sized ice crystallites corresponds to that of hexagonal ice, the thermodynamically stable form of bulk ice. However, simulations with various water models find that ice nucleated and grown under atmospheric temperatures is at all sizes stacking-disordered, consisting of random sequences of cubic and hexagonal ice layers. This implies that stacking-disordered ice crystallites either are more stable than hexagonal ice crystallites or form because of non-equilibrium dynamical effects. Both scenarios challenge central tenets of classical nucleation theory. Here we use rare-event sampling and free energy calculations with the mW water model to show that the entropy of mixing cubic and hexagonal layers makes stacking-disordered ice the stable phase for crystallites up to a size of at least 100,000 molecules. We find that stacking-disordered critical crystallites at 230 kelvin are about 14 kilojoules per mole of crystallite more stable than hexagonal crystallites, making their ice nucleation rates more than three orders of magnitude higher than predicted by classical nucleation theory. This effect on nucleation rates is temperature dependent, being the most pronounced at the warmest conditions, and should affect the modelling of cloud formation and ice particle numbers, which are very sensitive to the temperature dependence of ice nucleation rates. We conclude that classical nucleation theory needs to be corrected to include the dependence of the crystallization driving force on the size of the ice crystallite when interpreting and extrapolating ice nucleation rates from experimental laboratory conditions to the temperatures that occur in clouds.

Timing of Benthic Foraminiferal δ18O Change in Deep and Intermediate Waters of the Atlantic and Indo-Pacific for 0-45 ka

NASA Astrophysics Data System (ADS)

Stern, J.; Lisiecki, L. E.

2011-12-01

Isotopic and compositional studies of marine sediment cores provide a wealth of insight into past and present climate processes, but accurately dating these records remains problematic. Age models developed by correlation of marine isotope stages in benthic foraminiferal δ18O are limited by the degree to which similarity in the timing and character of the records can be assumed. Skinner and Shackleton (2005) demonstrated that the marine isotope stage (MIS) 2/1 boundary in benthic foraminiferal δ18O occurred ~4,000 yr later at a deep equatorial Pacific site compared to a deep North Atlantic site due to diachronous changes in deep water temperature and local hydrography during the deglaciation. To further investigate the extent of potential differences at both orbital and millennial timescales, we compare stacks of benthic foraminiferal δ18O for the intermediate Atlantic, deep Atlantic, intermediate Indo-Pacific, and deep Indo-Pacific. The four stacks were generated by averaging together 40, 153, 30, and 75 individual records, respectively. Unique age models for each of the four stacks from 0-45 ka are based on a total of >1,200 radiocarbon dates from planktonic foraminfera in a subset of the cores used for the stacks. We discuss the relative timing of major events during Termination I in the four stacks, including a prominent reversal ~13-15 ka in the intermediate Atlantic. We also compare the expression of millennial-scale climate change associated with Heinrich Event 4 in the four stacks.

Uranium chemistry in stack solutions and leachates of phosphogypsum disposed at a coastal area in Cyprus.

PubMed

Lysandrou, M; Pashalidis, I

2008-02-01

The effect of the matrix composition (main constituents) on the concentration and chemical behavior of uranium in phosphogypsum stack solutions and leachates has been investigated. Solid and aqueous samples were taken from three different sub-areas of a phosphogypsum stack at a coastal area in Vasilikos (Cyprus). The sub-areas are characterized whether by their acidity (e.g. "aged" and "non-aged" phosphogypsum) or by their salt content, originating from pulping water during wet stacking or (after deposition) from the adjacent sea. Measurements in stack solutions and leachates showed that phosphogypsum characteristics affect both, the concentration and the chemical behavior of uranium in solution. Uranium concentration in solutions of increased salinity is up to three orders of magnitude higher than in solutions of low salinity and this is attributed to the effect of ionic strength on the solubility of phosphogypsum. Modelling showed that uranium in stack solutions is predominantly present in the form of uranium(VI) phosphate complexes (e.g. UO(2)(H(2)PO(4))(2), UO(2)HPO(4)), whereas in leachates uranium(VI) fluoro complexes (e.g. UO(2)F(2), UO(2)F(3)(-)) are predominant in solution. The latter indicates that elution of uranium from phosphogypsum takes places most probably in the form of fluoro complexes. Both, effective elution by saline water and direct migration of uranium to the sea, where it forms very stable uranium(VI) carbonato complexes, indicate that the adjacent sea will be the final receptor of uranium released from Vasilikos phosphogypsum.

Environmental Control and Life Support System Mockup

NASA Technical Reports Server (NTRS)

2001-01-01

The Environmental Control and Life Support System (ECLSS) Group of the Flight Projects Directorate at the Marshall Space Flight Center in Huntsville, Alabama, is responsible for designing and building the life support systems that will provide the crew of the International Space Station (ISS) a comfortable environment in which to live and work. This photograph shows the mockup of the the ECLSS to be installed in the Node 3 module of the ISS. From left to right, shower rack, waste management rack, Water Recovery System (WRS) Rack #2, WRS Rack #1, and Oxygen Generation System (OGS) rack are shown. The WRS provides clean water through the reclamation of wastewaters and is comprised of a Urine Processor Assembly (UPA) and a Water Processor Assembly (WPA). The UPA accepts and processes pretreated crewmember urine to allow it to be processed along with other wastewaters in the WPA. The WPA removes free gas, organic, and nonorganic constituents before the water goes through a series of multifiltration beds for further purification. The OGS produces oxygen for breathing air for the crew and laboratory animals, as well as for replacing oxygen loss. The OGS is comprised of a cell stack, which electrolyzes (breaks apart the hydrogen and oxygen molecules) some of the clean water provided by the WRS, and the separators that remove the gases from the water after electrolysis.

Lidar and aircraft studies of deep Cirrus systems from the 1986 FIRE IFO

NASA Technical Reports Server (NTRS)

Sassen, Kenneth; Heymsfield, Andrew J.; Knight, Nancy C.

1990-01-01

Several NCAR King Air flight missions were conducted during the Wisconsin FIRE IFO experiment in support of the University of Utah polarization lidar observations of deep cirrus cloud systems at the Wausau ground site. Data collected from four cirrus systems are included in this analysis, including those of 22 and 28 October, and 1 and 2 November. Lidar data were generally obtained at 2 min intervals in the zenith direction over observation periods that ranged from approximately 4 to 10 h, bracketing the aircraft missions. The data were processed to yield height-time (HTI) displays of lidar linear depolarization ratio sigma and relative range-normalized return power P. King Air operations consisted of a combination of rapid profiling and Lagrangian spiral descents and stacked racetrack patterns in the vicinity of the field site. From the spiral descents are constructed vertical profiles of ice particle concentration N(sub i) and ice mass content IWC derived from PMS 2-D probe imagery and, when detected, FSSP cloud droplet concentration N(sub W) and liquid water content, LWC. Aircraft flight leg data are presented for the vertical velocity W and the same ice and water cloud content parameters. In addition, aerosol particle concentrations obtained with the ASAS probe are examined, and photographs of ice particles collected in-situ on oil-coated slides are presented to illustrate ice particle habit.

Design and demonstration of a storage-assisted air conditioning system

NASA Astrophysics Data System (ADS)

Rizzuto, J. E.

1981-03-01

The system is a peak-shaving system designed to provide a levelized air conditioning load. The system also requires minimum air conditioner and thermal storage capacity. The storage-assisted air conditioning system uses a Glauber's salt-based phase change material in sausage like containers called CHUBS. The CHUBS are two (2) inches in diameter and 20 inches long. They are stacked in modules of 64 CHUBS which are appropriately spaced and oriented in the storage system so that air may pass perpendicular to the long axis of the CHUBS. The phase change material, has a thermal storage capacity in the range of 45 to 50 Btu/lb and a transition temperature of approximately 55 F.

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.

Environmental tracers for elucidating the weathering process in a phosphogypsum disposal site: Implications for restoration

NASA Astrophysics Data System (ADS)

Pérez-López, Rafael; Nieto, José M.; de la Rosa, Jesús D.; Bolívar, Juan P.

2015-10-01

This study provides geochemical data with the aim of identifying and tracing the weathering of phosphogypsum wastes stack-piled directly on salt-marshes of the Tinto River (Estuary of Huelva, SW Spain). With that purpose, different types of highly-polluted acid solutions were collected in the stack. Connection between these solutions and the estuarine environment was studied by geochemical tracers, such as rare earth elements (REE) and their North American Shale Composite (NASC)-normalized patterns and Cl/Br ratios. Phosphogypsum-related wastewaters include process water stored on the surface, pore-water contained in the phosphogypsum profile and edge outflow water emerging from inside the stack. Edge outflow waters are produced by waterlogging at the contact between phosphogypsum and the nearly impermeable marsh surface and discharge directly into the estuary. Process water shows geochemical characteristics typical of phosphate fertilizers, i.e. REE patterns with an evident enrichment of heavy-REE (HREE) with respect to middle-REE (MREE) and light-REE (LREE). By contrast, REE patterns of deeper pore-water and edge outflows are identical to those of Tinto River estuary waters, with a clear enrichment of MREE relative to LREE and HREE denoting influence of acid mine drainage. Cl/Br ratios of these solutions are very close to that of seawater, which also supports its estuarine origin. These findings clearly show that process water is not chemically connected with edge outflows through pore-waters, as was previously believed. Phosphogypsum weathering likely occurs by an upward flow of seawater from the marsh because of overpressure and permeability differences. Several recommendations are put forward in this study to route restoration actions, such as developing treatment systems to improve the quality of the edge outflow waters before discharging to the receiving environment.

Fluid flow in porous media using image-based modelling to parametrize Richards' equation.

PubMed

Cooper, L J; Daly, K R; Hallett, P D; Naveed, M; Koebernick, N; Bengough, A G; George, T S; Roose, T

2017-11-01

The parameters in Richards' equation are usually calculated from experimentally measured values of the soil-water characteristic curve and saturated hydraulic conductivity. The complex pore structures that often occur in porous media complicate such parametrization due to hysteresis between wetting and drying and the effects of tortuosity. Rather than estimate the parameters in Richards' equation from these indirect measurements, image-based modelling is used to investigate the relationship between the pore structure and the parameters. A three-dimensional, X-ray computed tomography image stack of a soil sample with voxel resolution of 6 μm has been used to create a computational mesh. The Cahn-Hilliard-Stokes equations for two-fluid flow, in this case water and air, were applied to this mesh and solved using the finite-element method in COMSOL Multiphysics. The upscaled parameters in Richards' equation are then obtained via homogenization. The effect on the soil-water retention curve due to three different contact angles, 0°, 20° and 60°, was also investigated. The results show that the pore structure affects the properties of the flow on the large scale, and different contact angles can change the parameters for Richards' equation.

The evaluation of stack metal emissions from hazardous waste incinerators: assessing human exposure through noninhalation pathways.

PubMed Central

Sedman, R M; Polisini, J M; Esparza, J R

1994-01-01

Potential public health effects associated with exposure to metal emissions from hazardous waste incinerators through noninhalation pathways were evaluated. Instead of relying on modeling the movement of toxicants through various environmental media, an approach based on estimating changes from baseline levels of exposure was employed. Changes in soil and water As, Cd, Hg, Pb, Cr, and Be concentrations that result from incinerator emissions were first determined. Estimates of changes in human exposure due to direct contact with shallow soil or the ingestion of surface water were then ascertained. Projected changes in dietary intakes of metals due to incinerator emissions were estimated based on changes from baseline dietary intakes that are monitored in U.S. Food and Drug Administration total diet studies. Changes from baseline intake were deemed to be proportional to the projected changes in soil or surface water metal concentrations. Human exposure to metals emitted from nine hazardous waste incinerators were then evaluated. Metal emissions from certain facilities resulted in tangible human exposure through noninhalation pathways. However, the analysis indicated that the deposition of metals from ambient air would result in substantially greater human exposure through noninhalation pathways than the emissions from most of the facilities. PMID:7925180

15. SITE BUILDING 004 ELECTRIC POWER STATION VIEW ...

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

15. SITE BUILDING 004 - ELECTRIC POWER STATION - VIEW IS LOOKING SOUTH 55° EAST AT FIVE DIESEL ENGINE/ GENERATOR SILENCER SYSTEM EXHAUST STACKS. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

Lamination effects on a 3D model of the magnetic core of power transformers

NASA Astrophysics Data System (ADS)

Poveda-Lerma, Antonio; Serrano-Callergues, Guillermo; Riera-Guasp, Martin; Pineda-Sanchez, Manuel; Puche-Panadero, Ruben; Perez-Cruz, Juan

2017-12-01

In this paper the lamination effect on the model of a power transformer's core with stacked E-I structure is analyzed. The distribution of the magnetic flux in the laminations depends on the stacking method. In this work it is shown, using a 3D FEM model and an experimental prototype, that the non-uniform distribution of the flux in a laminated E-I core with alternate-lap joint stack increases substantially the average value of the magnetic flux density in the core, compared with a butt joint stack. Both the simulated model and the experimental tests show that the presence of constructive air-gaps in the E-I junctions gives rise to a zig-zag flux in the depth direction. This inter-lamination flux reduces the magnetic flux density in the I-pieces and increases substantially the magnetic flux density in the E-pieces, with highly saturated points that traditional 2D analysis cannot reproduce. The relation between the number of laminations included in the model, and the computational resourses needed to build it, is also evaluated in this work.

Aeroservoelastic Stability Analysis of the X-43A Stack

NASA Technical Reports Server (NTRS)

Pak, Chan-gi

2008-01-01

The first air launch attempt of an X-43A stack, consisting of the booster, adapter and Hyper-X research vehicle, ended in failure shortly after the successful drop from the National Aeronautics and Space Administration Dryden Flight Research Center (Edwards, California) B-52B airplane and ignition of the booster. The stack was observed to begin rolling and yawing violently upon reaching transonic speeds, and the grossly oscillating fins of the booster separated shortly thereafter. The flight then had to be terminated with the stack out of control. Very careful linear flutter and aeroservoelastic analyses were subsequently performed as reported herein to numerically duplicate the observed instability. These analyses properly identified the instability mechanism and demonstrated the importance of including the flight control laws, rigid-body modes, structural flexible modes and control surface flexible modes. In spite of these efforts, however, the predicted instability speed remained more than 25 percent higher than that observed in flight. It is concluded that transonic shock phenomena, which linear analyses cannot take into account, are also important for accurate prediction of this mishap instability.

49 CFR 173.465 - Type A packaging tests.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., with contents, must be capable of withstanding the water spray, free drop, stacking and penetration... paragraph (b) of this section are met. (b) Water spray test. The water spray test must precede each test or test sequence prescribed in this section. The water spray test must simulate exposure to rainfall of...

Femtosecond laser ablation of highly oriented pyrolytic graphite: a green route for large-scale production of porous graphene and graphene quantum dots.

PubMed

Russo, Paola; Hu, Anming; Compagnini, Giuseppe; Duley, Walter W; Zhou, Norman Y

2014-02-21

Porous graphene (PG) and graphene quantum dots (GQDs) are attracting attention due to their potential applications in photovoltaics, catalysis, and bio-related fields. We present a novel way for mass production of these promising materials. The femtosecond laser ablation of highly oriented pyrolytic graphite (HOPG) is employed for their synthesis. Porous graphene (PG) layers were found to float at the water-air interface, while graphene quantum dots (GQDs) were dispersed in the solution. The sheets consist of one to six stacked layers of spongy graphene, which form an irregular 3D porous structure that displays pores with an average size of 15-20 nm. Several characterization techniques have confirmed the porous nature of the collected layers. The analyses of the aqueous solution confirmed the presence of GQDs with dimensions of about 2-5 nm. It is found that the formation of both PG and GQDs depends on the fs-laser ablation energy. At laser fluences less than 12 J cm(-2), no evidence of either PG or GQDs is detected. However, polyynes with six and eight carbon atoms per chain are found in the solution. For laser energies in the 20-30 J cm(-2) range, these polyynes disappeared, while PG and GQDs were found at the water-air interface and in the solution, respectively. The origin of these materials can be explained based on the mechanisms for water breakdown and coal gasification. The absence of PG and GQDs, after the laser ablation of HOPG in liquid nitrogen, confirms the proposed mechanisms.

Fast stack activation procedure and effective long-term storage for high-performance polymer electrolyte membrane fuel cell

NASA Astrophysics Data System (ADS)

Yang, Seung Yong; Seo, Dong-Jun; Kim, Myeong-Ri; Seo, Min Ho; Hwang, Sun-Mi; Jung, Yong-Min; Kim, Beom-Jun; Yoon, Young-Gi; Han, Byungchan; Kim, Tae-Young

2016-10-01

Time-saving stack activation and effective long-term storage are one of most important issues that must be resolved for the commercialization of polymer electrolyte membrane fuel cell (PEMFC). Herein, we developed the cost-effective stack activation method to finish the whole activation within 30 min and the long-term storage method by using humidified N2 without any significant decrease in cell's performance for 30 days. Specifically, the pre-activation step with the direct injection of DI water into the stack and storage at 65 or 80 °C for 2 h increases the distinctive phase separation between the hydrophobic and hydrophilic regions in Nafion membrane, which significantly reduces the total activation time within 30 min. Additionally, the long-term storage with humidified N2 has no effect on the Pt oxidation and drying of Nafion membrane for 30 days due to its exergonic reaction in the cell. As a result, the high water content in Nafion membrane and the decrease of Pt oxidation are the critical factors that have a strong influence on the activation and long-term storage for high-performance PEMFC.

Thermodynamics-hydration relationships within loops that affect G-quadruplexes under molecular crowding conditions.

PubMed

Fujimoto, Takeshi; Nakano, Shu-ichi; Sugimoto, Naoki; Miyoshi, Daisuke

2013-01-31

We systematically investigated the effects of loop length on the conformation, thermodynamic stability, and hydration of DNA G-quadruplexes under dilute and molecular crowding conditions in the presence of Na(+). Structural analysis showed that molecular crowding induced conformational switches of oligonucleotides with the longer guanine stretch and the shorter thymine loop. Thermodynamic parameters further demonstrated that the thermodynamic stability of G-quadruplexes increased by increasing the loop length from two to four, whereas it decreased by increasing the loop length from four to six. Interestingly, we found by osmotic pressure analysis that the number of water molecules released from the G-quadruplex decreased with increasing thermodynamic stability. We assumed that base-stacking interactions within the loops not only stabilized the whole G-quadruplex structure but also created hydration sites by accumulating nucleotide functional groups. The molecular crowding effects on the stability of G-quadruplexes composed of abasic sites, which reduce the stacking interactions at the loops, further demonstrated that G-quadruplexes with fewer stacking interactions within the loops released a larger number of water molecules upon folding. These results showed that the stacking interactions within the loops determined the thermodynamic stability and hydration of the whole G-quadruplex.

Air Force Studies Board Block 00 Studies

DTIC Science & Technology

2016-07-14

effectively in efforts aimed at reducing energy consumption . Without more data on energy use, “You don’t know what you don’t know.” The question was raised...with Oxygen Trim Maintain Excess Oxygen Below 5%, Below 8% for Stokers Reduce Stack Temperature to 330°F for Sulfur Bearing Fuels Minimize...current approaches to industrial process energy with a goal of highlighting potential ways to reduce Air Force industrial process energy consumption .1

Hydration of Caffeine at High Temperature by Neutron Scattering and Simulation Studies.

PubMed

Tavagnacco, L; Brady, J W; Bruni, F; Callear, S; Ricci, M A; Saboungi, M L; Cesàro, A

2015-10-22

The solvation of caffeine in water is examined with neutron diffraction experiments at 353 K. The experimental data, obtained by taking advantage of isotopic H/D substitution in water, were analyzed by empirical potential structure refinement (EPSR) in order to extract partial structure factors and site-site radial distribution functions. In parallel, molecular dynamics (MD) simulations were carried out to interpret the data and gain insight into the intermolecular interactions in the solutions and the solvation process. The results obtained with the two approaches evidence differences in the individual radial distribution functions, although both confirm the presence of caffeine stacks at this temperature. The two approaches point to different accessibility of water to the caffeine sites due to different stacking configurations.

Experimental investigations of stability of static liquid fillets and liquid-gas interface in capillary passages for gas-free liquid acquisition in zero gravity

NASA Astrophysics Data System (ADS)

Purohit, Ghanshyam Purshottamdas

Experimental investigations of static liquid fillets formed between small gaps of a cylindrical surface and a flat surface are carried out. The minimum volume of liquid required to form a stable fillet and the maximum liquid content the fillet can hold before becoming unstable are studied. Fillet shapes are captured in photographs obtained by a high speed image system. Experiments were conducted using water, UPA and PF 5060 on two surfaces-stand-blasted titanium and polished copper for different surface inclinations. Experimental data are generalized using appropriate non-dimensional groups. Analytical model are developed to describe the fillet curvature. Fillet curvature data are compared against model predictions and are found to be in close agreement. Bubble point experiments were carried out to measure the capillary pressure difference across the liquid-gas interface in the channels of photo-chemically etched disk stacks. Experiments were conducted using titanium stacks of five different geometrical configurations. Both well wetting liquids (IPA and PF5060) and partially wetting liquid (water) were used during experiments. Test results are found to be in close agreement with analytical predictions. Experiments were carried out to measure the frictional pressure drop across the stack as a function of liquid flow rate using two different liquids (water and IPA) and five stacks of different geometrical configurations. A channel pressure drop model is developed by treating the flow within stack channels as fully developed laminar flow between parallel plates and solving the one-dimensional Navier Stokes equation. An alternate model is developed by treating the flow in channels as flow within porous media. Expressions are developed for effective porosity and permeability for the stacks and the pressure drop is related to these parameters. Pressure drop test results are found to be in close agreement with model predictions. As a specific application of this work, a surface tension propellant management device (PMD) that uses photo-chemically etched disk stacks as capillary elements is examined. These PMDs are used in gas pressurized liquid propellant tanks to supply gas-free propellant to rocket engines in near zero-gravity environment. The experimentally validated models are integrated to perform key analyses for predicting PMD performance in zero gravity.

Thermal management of advanced fuel cell power systems

NASA Technical Reports Server (NTRS)

Vanderborgh, N. E.; Hedstrom, J.; Huff, J.

1990-01-01

It is shown that fuel cell devices are particularly attractive for the high-efficiency, high-reliability space hardware necessary to support upcoming space missions. These low-temperature hydrogen-oxygen systems necessarily operate with two-phase water. In either PEMFCs (proton exchange membrane fuel cells) or AFCs (alkaline fuel cells), engineering design must be critically focused on both stack temperature control and on the relative humidity control necessary to sustain appropriate conductivity within the ionic conductor. Water must also be removed promptly from the hardware. Present designs for AFC space hardware accomplish thermal management through two coupled cooling loops, both driven by a heat transfer fluid, and involve a recirculation fan to remove water and heat from the stack. There appears to be a certain advantage in using product water for these purposes within PEM hardware, because in that case a single fluid can serve both to control stack temperature, operating simultaneously as a heat transfer medium and through evaporation, and to provide the gas-phase moisture levels necessary to set the ionic conductor at appropriate performance levels. Moreover, the humidification cooling process automatically follows current loads. This design may remove the necessity for recirculation gas fans, thus demonstrating the long-term reliability essential for future space power hardware.

Structural and dynamic characteristics in monolayer square ice.

PubMed

Zhu, YinBo; Wang, FengChao; Wu, HengAn

2017-07-28

When water is constrained between two sheets of graphene, it becomes an intriguing monolayer solid with a square pattern due to the ultrahigh van der Waals pressure. However, the square ice phase has become a matter of debate due to the insufficient experimental interpretation and the slightly rhomboidal feature in simulated monolayer square-like structures. Here, we performed classical molecular dynamics simulations to reveal monolayer square ice in graphene nanocapillaries from the perspective of structure and dynamic characteristics. Monolayer square-like ice (instantaneous snapshot), assembled square-rhombic units with stacking faults, is a long-range ordered structure, in which the square and rhombic units are assembled in an order of alternative distribution, and the other rhombic unit forms stacking faults (polarized water chains). Spontaneous flipping of water molecules in monolayer square-like ice is intrinsic and induces transformations among different elementary units, resulting in the structural evolution of monolayer square ice in dynamics. The existence of stacking faults should be attributed to the spontaneous flipping behavior of water molecules under ambient temperature. Statistical averaging results (thermal average positions) demonstrate the inherent square characteristic of monolayer square ice. The simulated data and insight obtained here might be significant for understanding the topological structure and dynamic behavior of monolayer square ice.

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

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.

Method for Making a Fuel Cell from a Solid Oxide Monolithic Framework

NASA Technical Reports Server (NTRS)

Sofie, Stephen W. (Inventor); Cable, Thomas L. (Inventor)

2014-01-01

The invention is a novel solid oxide fuel cell (SOFC) stack comprising individual bi-electrode supported fuel cells in which a thin electrolyte is supported between electrodes of essentially equal thickness. Individual cell units are made from graded pore ceramic tape that has been created by the freeze cast method followed by freeze drying. Each piece of graded pore tape later becomes a graded pore electrode scaffold that subsequent to sintering, is made into either an anode or a cathode by means of appropriate solution and thermal treatment means. Each cell unit is assembled by depositing of a thin coating of ion conducting ceramic material upon the side of each of two pieces of tape surface having the smallest pore openings, and then mating the coated surfaces to create an unsintered electrode scaffold pair sandwiching an electrolyte layer. The opposing major outer exposed surfaces of each cell unit is given a thin coating of electrically conductive ceramic, and multiple cell units are stacked, or built up by stacking of individual cell layers, to create an unsintered fuel cell stack. Ceramic or glass edge seals are installed to create flow channels for fuel and air. The cell stack with edge sealants is then sintered into a ceramic monolithic framework. Said solution and thermal treatments means convert the electrode scaffolds into anodes and cathodes. The thin layers of electrically conductive ceramic become the interconnects in the assembled stack.

Annular feed air breathing fuel cell stack

DOEpatents

Wilson, Mahlon S.

1996-01-01

A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

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.

Dynamic response performance of proton exchange membrane fuel cell stack with Pt/C-RuO2·xH2O electrode

NASA Astrophysics Data System (ADS)

Lu, Lu; Xu, Hongfeng; Zhao, Hong; Sun, Xin; Dong, Yiming; Ren, Ruiming

2013-11-01

The dynamic response performance of a proton exchange membrane fuel cell (PEMFC) significantly affects its durability and reliability. Thus, the improvement of the dynamic performance of PEMFC has become the key for prolonging the PEMFC life in fuel cell vehicle applications. In this study, RuO2·xH2O is prepared by sol-gel method, and then sprayed onto catalyst layers to promote PEMFC dynamic response performance. The prepared RuO2·xH2O is characterized by TEM, which shows that the average particle size of RuO2·xH2O is 8 nm and that the particulates are uniformly distributed. A 10-cell stack is assembled using membrane electrode assembly (MEA) with and without RuO2·xH2O. This stack is studied under various loading cycles and operating conditions, including different air stoichiometries, relative humidities, and loading degrees. Results show that the steady-state performance of the MEA with RuO2·xH2O is better than that in the MEA without RuO2·xH2O with a decreasing relative humidity from 80% to 20%. A slower and more unstable dynamic response of the MEA without RuO2·xH2O is observed as air stoichiometry and relative humidity decrease as well as the loading increase. Thus, RuO2·xH2O improves the dynamic response performance, indicating that RuO2·xH2O can buffer the voltage undershoot, improve the stability, and prolong the lifetime of the PEMFC stack.

REDUCTION OF COAL-BASED METAL EMISSIONS BY FURNACE SORBENT INJECTION

EPA Science Inventory

The ability of sorbent injection technology to reduce the potential for trace metal emissions from coal combustion was researched. Pilot scale tests of high-temperature furnace sorbent injection were accompanied by stack sampling for coal-based, metallic air toxics. Tested sorben...

40 CFR 63.1352 - Additional test methods.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing Industry... determine the rates of emission of HCl from kilns and associated bypass stacks at portland cement... emission of specific organic HAP from raw material dryers, and kilns at Portland cement manufacturing...

40 CFR 52.990 - Stack height regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 52.990 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... emission limitation for a specific source exceeds the height allowed by Section 921(A) “Good Engineering... Department of Environmental Quality, dated September 23, 1986, stated that: In specific, the State regulation...

Reduce Air Infiltration in Furnaces (English/Chinese) (Fact Sheet) (in Chinese; English)

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

Not Available

Chinese translation of the Reduce Air Infiltration in Furnaces fact sheet. Provides suggestions on how to improve furnace energy efficiency. Fuel-fired furnaces discharge combustion products through a stack or a chimney. Hot furnace gases are less dense and more buoyant than ambient air, so they rise, creating a differential pressure between the top and the bottom of the furnace. This differential, known as thermal head, is the source of a natural draft or negative pressure in furnaces and boilers. A well-designed furnace (or boiler) is built to avoid air leakage into the furnace or leakage of flue gases from themore » furnace to the ambient. However, with time, most furnaces develop cracks or openings around doors, joints, and hearth seals. These openings (leaks) usually appear small compared with the overall dimensions of the furnace, so they are often ignored. The negative pressure created by the natural draft (or use of an induced-draft fan) in a furnace draws cold air through the openings (leaks) and into the furnace. The cold air becomes heated to the furnace exhaust gas temperature and then exits through the flue system, wasting valuable fuel. It might also cause excessive oxidation of metals or other materials in the furnaces. The heat loss due to cold air leakage resulting from the natural draft can be estimated if you know four major parameters: (1) The furnace or flue gas temperature; (2) The vertical distance H between the opening (leak) and the point where the exhaust gases leave the furnace and its flue system (if the leak is along a vertical surface, H will be an average value); (3) The area of the leak, in square inches; and (4) The amount of operating time the furnace spends at negative pressure. Secondary parameters that affect the amount of air leakage include these: (1) The furnace firing rate; (2) The flue gas velocity through the stack or the stack cross-section area; (3) The burner operating conditions (e.g., excess air, combustion air temperature, and so on). For furnaces or boilers using an induced-draft (ID) fan, the furnace negative pressure depends on the fan performance and frictional losses between the fan inlet and the point of air leakage. In most cases, it would be necessary to measure or estimate negative pressure at the opening. The amount of air leakage, the heat lost in flue gases, and their effects on increased furnace or boiler fuel consumption can be calculated by using the equations and graphs given in Industrial Furnaces (see W. Trinks et al., below). Note that the actual heat input required to compensate for the heat loss in flue gases due to air leakage would be greater than the heat contained in the air leakage because of the effect of available heat in the furnace. For a high-temperature furnace that is not maintained properly, the fuel consumption increase due to air leakage can be as high as 10% of the fuel input.« less

Stacking of purines in water: the role of dipolar interactions in caffeine.

PubMed

Tavagnacco, L; Di Fonzo, S; D'Amico, F; Masciovecchio, C; Brady, J W; Cesàro, A

2016-05-11

During the last few decades it has been ascertained that base stacking is one of the major contributions stabilizing nucleic acid conformations. However, the understanding of the nature of the interactions involved in the stacking process remains under debate and it is a subject of theoretical and experimental studies. Structural similarity between purine bases (guanine and adenine) in DNA and the caffeine molecule makes caffeine an excellent model for the purine bases. The present study clearly shows that dipolar interactions play a fundamental role in determining stacking of purine molecules in solution. In order to reach this achievement, polarized ultraviolet Raman resonant scattering experiments have been carried out on caffeine aqueous solutions as a function of concentration and temperature. The investigation pointed out at the aggregation and solvation properties, particularly at elevated temperatures. Kubo-Anderson theory was used as a framework to investigate the non-coincidence effect (NCE) occurring in the totally symmetric breathing modes of the purine rings, and in the bending modes of the methyl groups of caffeine. The NCE concentration dependence shows that caffeine aggregation at 80 °C occurs by planar stacking of the hydrophobic faces. The data clearly indicate that dipolar interactions determine the reorientational motion of the molecules in solution and are the driving force for the stacking of caffeine. In parallel, the observed dephasing times imply a change in caffeine interactions as a function of temperature and concentration. A decrease, at low water content, of the dephasing time for the ring breathing vibration mode indicates that self-association alters the solvation structure that is detectable at low concentration. These results are in agreement with simulation predictions and serve as an important validation of the models used in those calculations.

MICRO AUTO GASIFICATION SYSTEM: EMISSIONS ...

EPA Pesticide Factsheets

A compact, CONEX-housed waste to energy unit, Micro Auto Gasification System (MAGS), was characterized for air emissions from burning of military waste types. The MAGS unit is a dual chamber gasifier with a secondary diesel-fired combustor. Eight tests were conducted with multiple waste types in a 7-day period at the Kilauea Military Camp in Hawai’i. The emissions characterized were chosen based on regulatory emissions limits as well as their ability to cause adverse health effects on humans: particulate matter (PM), mercury, heavy metals, volatile organic compounds (VOCs), polyaromatic hydrocarbons (PAHs), and polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Three military waste feedstock compositions reflecting the variety of wastes to be encountered in theatre were investigated: standard waste (SW), standard waste with increased plastic content (HP), standard waste without SW food components but added first strike ration (FSR) food and packaging material (termed FSR). A fourth waste was collected from the Kilauea dumpster that served the dining facility and room lodging (KMC). Limited scrubber water and solid ash residue samples were collected to obtain a preliminary characterization of these effluents/residues.Gasifying SW, HP, and KMC resulted in similar PCDD/PCDF stack concentrations, 0.26-0.27 ng TEQ/m3 at 7% O2, while FSR waste generated a notably higher stack concentration of 0.68 ng TEQ/m3 at 7% O2. The PM emission

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.

Evaluations of HRI (Heat Recovery Incinerators) at NS (Naval Station) Mayport and NAS (Naval Air Station) Jacksonville, Florida-Lessons Learned Report.

DTIC Science & Technology

1984-07-01

primary chamber is lined with 2 in. of insulating mineral wool and 4 in. of castable refractory with a service temperature of 2500*F. 5.5.5.4...material. The refractory should be air cooled by circulating combustion air between it and the outer shell. A minimum of 2-in.-high density mineral wool or...passes through the roof. The 50-ft-high and 6-ft-4-in.-O.D. stack is constructed of steel and lined with 4 in. of refractory and 2 in. of mineral

Natural ventilation of buildings: opposing wind and buoyancy

NASA Astrophysics Data System (ADS)

Linden, Paul; Hunt, Gary

1998-11-01

The use of natural ventilation in buildings is an attractive way to reduce energy usage thereby reducing costs and CO2 emissions. Generally, it is necessary to remove excess heat from a building and the designer can use the buoyancy forces associated with the above ambient temperatures within the building to drive a flow - 'stack' ventilation. The most efficient mode is displacement ventilation where warm air accumulates near the top of the building and flows out through upper level vents and cooler air flows in at lower levels. Ventilation will also be driven between these lower and upper openings by the wind. We report on laboratory modeling and theory which investigates the effects of an opposing wind on stack ventilation driven by a constant source of heat within a space under displacement ventilation. We show that there is a critical wind speed, expressed in dimensionless terms as a critical Froude number, above which displacement ventilation is replaced by (less efficient) mixing ventilation with reversed flow. Below this critical speed, displacement ventilation, in which the interior has a two-layer stratification, is maintained. The criterion for the change in ventilation mode is derived from general considerations of mixing efficiencies in stratified flows. We conclude that even when wind effects might appear to be dominant, the inhibition of mixing by the stable stratification within the space ensures that stack ventilation can operate over a wide range of apparently adverse conditions.

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.

Waste separation: Does it influence municipal waste combustor emissions?

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

Chandler, A.J.; Rigo, H.G.

1996-09-01

It has been suggested that MSW incinerator emissions show significant variations because of the heterogeneous nature of the waste fed to the furnace. This argument has even been used to propose banning certain materials from incinerators. However, data previously reported by the authors suggests that a large portion of the trace metals come from natural sources. Furthermore, full scale incinerator spiking experiments suggest that certain forms of trace metals have minimal effects on stack emissions. Similar studies with chlorinated plastics have failed to identify a significant effect on incinerator dioxin emissions. The implication of segregating the lawn and garden wastemore » and other fines from the furnace feed is explored using data from a 400 tpd mass burn facility equipped with a conditioning tower, dry reactor and fabric filter air pollution control system (APCS) preceded by an NRT separation system. The stack emissions have been tested periodically since commissioning to characterize emissions for various seasons using both processed fuel and raw MSW. Front end processing to remove selected portions of the waste stream based upon size or physical properties, i.e. fines, grass, or ferrous materials, did not result in a statistically significant difference in stack emissions. System operating regime, and in particular those that effect the effective air to cloth ratio in the fabric filter, appear to be the principal influence on emission levels.« less

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 52.1832 - Stack height regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 52.1832 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... letter to Douglas M. Skie, EPA, dated May 11, 1988, Dana K. Mount, Director, Division of Environmental Engineering stated: * * * We are submitting this letter to allow EPA to continue to process our current SIP...

The Evolution of Academic Library Architecture: A Summary.

ERIC Educational Resources Information Center

Toombs, Kenneth E.

1992-01-01

Reviews the history of architectural developments in academic libraries. Highlights include natural lighting and the invention of the incandescent bulb; compact shelving; open versus closed stacks; modular construction methods; central air conditioning and controlled environments; interior arrangements; access to handicapped users and staff; and…

COST EFFECTIVE CONTROL OF HEXAVALENT CHROMIUM AIR EMISSIONS FROM FUNCTIONAL CHROMIUM ELECTROPLATING

EPA Science Inventory

This paper will summrize thie pollution prevention (p2) method to control stack emissions from hard chromium plating operations performed by the USEPA's National Risk Management Research Laboratory (NRMRL) over the last four years. During literature research and user surveys, it...

DETAIL VIEW OF A HANDHELD “BUMPER,” USED TO AID IN ...

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

DETAIL VIEW OF A HANDHELD “BUMPER,” USED TO AID IN POSITIONING THE ORBITER DURING STACKING PROCEDURES - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

PHOTOCHEMICAL AND AEROSOL MODELING WITH THE CMAQ PLUME-IN-GRID APPROACH

EPA Science Inventory

Emissions of nitrogen oxides (NO) and/or sulfur oxides (SO) from individual point sources, such as coal-fired power plants, with tall stacks contribute to reduced air quality. These primary species are important precursors of various oxidant species and secondary fine particul...

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

May, C.A.; Breitigam, W.; Bauer, R.S.

The laminates that are used to prepare advanced composite parts generally require curing at high temperature and pressure, and their raw material shelf lives are limited. The epoxy resin systems that the authors describe here offer the potential of extended shelf life while curing at relatively low temperatures with a method the authors call rapid thermoset processing (RTP). A laminate is formed by stacking the prepreg in a pre-determined manner as required by the end product configuration. The prepreg is then bagged by placing it in a sealed envelope of a heat-resistant film, which is subsequently bonded to a metalmore » surface (the tool) with a heat-resistant vacuum bag putty. The bag has an access hole through which vacuum can be applied to the prepreg stack, facilitating removal of air and other volatiles. This assembly is then heated under vacuum and pressure in an autoclave, the resin melts, and any excess air or volatile matter bleeds from the configuration, resulting in the required dense, void-free laminate.« less

Bandwidth enhancement of electromagnetic coupled nonuniform H-shaped microstrip patch antenna for higher band of Wi-MAX applications

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

Bhardwaj, Dheeraj, E-mail: dbhardwaj.bit@gmail.com; Gulati, Gitansh, E-mail: gitanshgulati@gmail.com; Saraswat, Srishti, E-mail: saraswat.srishti@yahoo.in

The bandwidth enhancement of a stacked non-uniform electromagnetically coupled H-shaped Microstrip Antenna (SNHMA) with tapered edges is analyzed and simulated using the IE3D simulator. The proposed antenna prototype is drafted on FR-4 material and stacked further with an air discontinuity of 0.3 mm to the next layer. The various parameters optimized to achieve the best performance from the modified SNHMA primarily include a)length b)width of the patch c)air gap thickness. The redesigned antenna serves at two distinct frequencies with an elevated bandwidth of 30.85 % at the central frequency 5.762 GHz, approximately four times the bandwidth of the standard patch having themore » same dimensions. The simulated radiation patterns (E-plane and H-plane) are exhibited within the range of frequencies where the broadband response is observed. The specifications of the proposed structure make it promising for the higher band of Wi-MAX applications.« less

High power vertical stacked diode laser development using macro-channel water cooling and hard solder bonding technology

NASA Astrophysics Data System (ADS)

Yu, Dongshan; Liang, Xuejie; Wang, Jingwei; Li, Xiaoning; Nie, Zhiqiang; Liu, Xingsheng

2017-02-01

A novel marco channel cooler (MaCC) has been developed for packaging high power diode vertical stacked (HPDL) lasers, which eliminates many of the issues in commercially-available copper micro-channel coolers (MCC). The MaCC coolers, which do not require deionized water as coolant, were carefully designed for compact size and superior thermal dissipation capability. Indium-free packaging technology was adopted throughout product design and fabrication process to minimize the risk of solder electromigration and thermal fatigue at high current density and long pulse width under QCW operation. Single MaCC unit with peak output power of up to 700W/bar at pulse width in microsecond range and 200W/bar at pulse width in millisecond range has been recorded. Characteristic comparison on thermal resistivity, spectrum, near filed and lifetime have been conducted between a MaCC product and its counterpart MCC product. QCW lifetime test (30ms 10Hz, 30% duty cycle) has also been conducted with distilled water as coolant. A vertical 40-MaCC stack product has been fabricated, total output power of 9 kilowatts has been recorded under QCW mode (3ms, 30Hz, 9% duty cycle).

Three-wheel air turbocompressor for PEM fuel cell systems

DOEpatents

Rehg, Tim; Gee, Mark; Emerson, Terence P.; Ferrall, Joe; Sokolov, Pavel

2003-08-19

A fuel cell system comprises a compressor and a fuel processor downstream of the compressor. A fuel cell stack is in communication with the fuel processor and compressor. A combustor is downstream of the fuel cell stack. First and second turbines are downstream of the fuel processor and in parallel flow communication with one another. A distribution valve is in communication with the first and second turbines. The first and second turbines are mechanically engaged to the compressor. A bypass valve is intermediate the compressor and the second turbine, with the bypass valve enabling a compressed gas from the compressor to bypass the fuel processor.

77 FR 130 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Intercontinental...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-03

... issues: Water availability; Impacts from subsidence; Impacts to oil and gas exploration and operation in... processing facilities, including the ore process plant, dry stack tailings pile, evaporation ponds, water...

Solid oxide fuel cell power plant having a fixed contact oxidation catalyzed section of a multi-section cathode air heat exchanger

DOEpatents

Saito, Kazuo; Lin, Yao

2015-02-17

The multi-section cathode air heat exchanger (102) includes at least a first heat exchanger section (104), and a fixed contact oxidation catalyzed section (126) secured adjacent each other in a stack association. Cool cathode inlet air flows through cool air channels (110) of the at least first (104) and oxidation catalyzed sections (126). Hot anode exhaust flows through hot air channels (124) of the oxidation catalyzed section (126) and is combusted therein. The combusted anode exhaust then flows through hot air channels (112) of the first section (104) of the cathode air heat exchanger (102). The cool and hot air channels (110, 112) are secured in direct heat exchange relationship with each other so that temperatures of the heat exchanger (102) do not exceed 800.degree. C. to minimize requirements for using expensive, high-temperature alloys.

Simultaneous stack gas scrubbing wastewater purification

NASA Technical Reports Server (NTRS)

1978-01-01

Variations of a process for removing sulfur dioxide from stack gases and using it to treat municipal waste water are described. The once-through system lowers the pH of the scrubbing water from minor depressions to a pH of about 2.5 under certain conditions. A recycle system uses iron for catalytic oxidation of sulfurous acid to sulfuric acid allowing very large amounts of sulfur dioxide to be absorbed in a small portion of water. The partial recycle system uses municipal wastewater and iron as a scrubbing medium, followed by neutralization of the wastewater with lime to produce an iron hydroxide precipitation which, when removed, produces tertiary quality treated wastewater. The SO2 scrubber is described, test results are analyzed, and a preliminary capital cost estimate for the three processes is included.

Long-range Transported African Dust in the Caribbean Region: Dust Concentrations and Water-soluble Ions

NASA Astrophysics Data System (ADS)

Santos-Figueroa, G.; Avilés-Piñeiro, G. M.; Mayol-Bracero, O. L.

2017-12-01

Long-range transported African dust (LRTAD) particles reach the Caribbean region every year during the summer months causing an increase in PM10 concentrations and by consequence degradation of air quality. During African dust (AD) incursions at the Caribbean region, PM10 concentration could exceeds the exposure limit of 50 µg/m³ 24-hour mean established by the World Health Organization (WHO). To have a better understanding of the impacts of AD particles to climate and public health at the Caribbean region it is necessary to study and determine the spatial and temporal distribution of dust particles. In order to address this, aerosols samples were collected during and absence of AD incursions during the summer of 2017 using a Hi-Volume (Hi-Vol) sampler for total suspended particles (TSP) at two sampling stations in Puerto Rico. The first station is a marine site located at Cabezas de San Juan (CSJ) Nature Reserve in Fajardo, and the second station is an urban site located at the Facundo Bueso (FB) building at the University of Puerto Rico-Rio Piedras. Aerosol samples were collected using Whatman 41 grade filters from which we determined the concentration of dust particles and the water-soluble ions (e.g., Na+, NH4+, Ca+2, Cl-, SO4-2) in the presence and absence of LRTAD particles. Saharan Air Layer (SAL) imagery, the results from the air mass backward trajectories calculated with the NOAA Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT), and the spectral coefficients from measurements at CSJ were used to monitor and confirm the presence of air masses coming from North Africa. Average dust concentrations using the Stacked-Filter Units (SFUs) at CSJ are around 4 μg/m3. LRTAD concentrations and ionic speciation results using the Hi-Vol for the marine and urban sites will be presented at the conference.

Study on Self-start up of Polymer Electrolyte Fuel Cell Stack at Subzero Temperature

NASA Astrophysics Data System (ADS)

Shirato, Hiroyasu; Hoshina, Hideo; Yamakoshi, Yukiyasu; Tomita, Kazuhiko; Oka, Yoshiaki

This paper aims to boot up polymer electrolyte fuel cells at subzero temperature without energy from outside and compass the conditions. Visualization tests of water drainage and voltage-current density characteristics provided the selection of a serpentine type as a channel of a fuel cell separator for cold region. The successful start-up of the cell at subzero temperature requires suitable current densities corresponding to the ambient temperature since the lower the temperature is, the lower the cell voltage soon after the start-up is. Suitable amount of exhausted energy is also necessary for the successful self start-up. Humidification using potassium acetate 30 mass% solution provides increased impedance of the cell and inhibits the water freezing owing to its dispersal to the electrode compared to no humidification. A stack laminated 25 sheets of the serpentine type separators enables stabilized power generation at normal temperature. The stack is also bootable with no energy from outside at 263K.

Sample stacking of fast-moving anions in capillary zone electrophoresis with pH-suppressed electroosmotic flow.

PubMed

Quirino, J P; Terabe, S

1999-07-30

On-line sample concentration of fast moving inorganic anions by large volume sample stacking (LVSS) and field enhanced sample injection (FESI) with a water plug under acidic conditions is presented. Detection sensitivity enhancements were around 100 and 1000-fold for LVSS and FESI, respectively. However, reproducibility and linearity of response in the LVSS approach is superior compared to the FESI approach.

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...

Summary of Uranium Solubility Studies in Concrete Waste Forms and Vadose Zone Environments

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

Golovich, Elizabeth C.; Wellman, Dawn M.; Serne, R. Jeffrey

2011-09-30

One of the methods being considered for safely disposing of Category 3 low-level radioactive wastes is to encase the waste in concrete. Concrete encasement would contain and isolate the waste packages from the hydrologic environment and act as an intrusion barrier. The current plan for waste isolation consists of stacking low-level waste packages on a trench floor, surrounding the stacks with reinforced steel, and encasing these packages in concrete. These concrete-encased waste stacks are expected to vary in size with maximum dimensions of 6.4 m long, 2.7 m wide, and 4 m high. The waste stacks are expected to havemore » a surrounding minimum thickness of 15 cm of concrete encasement. These concrete-encased waste packages are expected to withstand environmental exposure (solar radiation, temperature variations, and precipitation) until an interim soil cover or permanent closure cover is installed and to remain largely intact thereafter. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. This report presents the results of investigations elucidating the uranium mineral phases controlling the long-term fate of uranium within concrete waste forms and the solubility of these phases in concrete pore waters and alkaline, circum-neutral vadose zone environments.« less

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

Christians, Jeffrey A.; Schulz, Philip; Tinkham, Jonathan S.

Long-term device stability is the most pressing issue that impedes perovskite solar cell commercialization, given the achieved 22.7% efficiency. The perovskite absorber material itself has been heavily scrutinized for being prone to degradation by water, oxygen and ultraviolet light. To date, most reports characterize device stability in the absence of these extrinsic factors. Here we show that, even under the combined stresses of light (including ultraviolet light), oxygen and moisture, perovskite solar cells can retain 94% of peak efficiency despite 1,000 hours of continuous unencapsulated operation in ambient air conditions (relative humidity of 10-20%). Each interface and contact layer throughoutmore » the device stack plays an important role in the overall stability which, when appropriately modified, yields devices in which both the initial rapid decay (often termed burn-in) and the gradual slower decay are suppressed. This extensively modified device architecture and the understanding developed will lead towards durable long-term device performance.« less

KSC-99pp1252

NASA Image and Video Library

1999-10-25

The Zero Emissions (ZE) transit bus tours the KSC Visitor Complex for a test ride. In the background are a mock-up orbiter named Explorer (left) and a stack of solid rocket boosters and external tank (right), typically used on Shuttle launches. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by-product "exhaust" from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. The ZE bus is being used on tour routes at the KSC Visitor Complex for two days to introduce the public to the concept

Major design issues of molten carbonate fuel cell power generation unit

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

Chen, T.P.

1996-04-01

In addition to the stack, a fuel cell power generation unit requires fuel desulfurization and reforming, fuel and oxidant preheating, process heat removal, waste heat recovery, steam generation, oxidant supply, power conditioning, water supply and treatment, purge gas supply, instrument air supply, and system control. These support facilities add considerable cost and system complexity. Bechtel, as a system integrator of M-C Power`s molten carbonate fuel cell development team, has spent substantial effort to simplify and minimize these supporting facilities to meet cost and reliability goals for commercialization. Similiar to other fuels cells, MCFC faces design challenge of how to complymore » with codes and standards, achieve high efficiency and part load performance, and meanwhile minimize utility requirements, weight, plot area, and cost. However, MCFC has several unique design issues due to its high operating temperature, use of molten electrolyte, and the requirement of CO2 recycle.« less

Direct hydrogen fuel cell systems for hybrid vehicles

NASA Astrophysics Data System (ADS)

Ahluwalia, Rajesh K.; Wang, X.

Hybridizing a fuel cell system with an energy storage system offers an opportunity to improve the fuel economy of the vehicle through regenerative braking and possibly to increase the specific power and decrease the cost of the combined energy conversion and storage systems. Even in a hybrid configuration it is advantageous to operate the fuel cell system in a load-following mode and use the power from the energy storage system when the fuel cell alone cannot meet the power demand. This paper discusses an approach for designing load-following fuel cell systems for hybrid vehicles and illustrates it by applying it to pressurized, direct hydrogen, polymer-electrolyte fuel cell (PEFC) systems for a mid-size family sedan. The vehicle level requirements relative to traction power, response time, start-up time and energy conversion efficiency are used to select the important parameters for the PEFC stack, air management system, heat rejection system and the water management system.

Hydrogen-oxygen driven Zero Emissions bus drives around KSC Visitor Complex

NASA Technical Reports Server (NTRS)

1999-01-01

The Zero Emissions (ZE) transit bus tours the KSC Visitor Complex for a test ride. In the background are a mock-up orbiter named Explorer (left) and a stack of solid rocket boosters and external tank (right), typically used on Shuttle launches. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by-product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. The ZE bus is being used on tour routes at the KSC Visitor Complex for two days to introduce the public to the concept.

Environmental impacts and sustainability of egg production systems.

PubMed

Xin, H; Gates, R S; Green, A R; Mitloehner, F M; Moore, P A; Wathes, C M

2011-01-01

As part of a systemic assessment toward social sustainability of egg production, we have reviewed current knowledge about the environmental impacts of egg production systems and identified topics requiring further research. Currently, we know that 1) high-rise cage houses generally have poorer air quality and emit more ammonia than manure belt (MB) cage houses; 2) manure removal frequency in MB houses greatly affects ammonia emissions; 3) emissions from manure storage are largely affected by storage conditions, including ventilation rate, manure moisture content, air temperature, and stacking profile; 4) more baseline data on air emissions from high-rise and MB houses are being collected in the United States to complement earlier measurements; 5) noncage houses generally have poorer air quality (ammonia and dust levels) than cage houses; 6) noncage houses tend to be colder during cold weather due to a lower stocking density than caged houses, leading to greater feed and fuel energy use; 7) hens in noncage houses are less efficient in resource (feed, energy, and land) utilization, leading to a greater carbon footprint; 8) excessive application of hen manure to cropland can lead to nutrient runoff to water bodies; 9) hen manure on open (free) range may be subject to runoff during rainfall, although quantitative data are lacking; 10) mitigation technologies exist to reduce generation and emission of noxious gases and dust; however, work is needed to evaluate their economic feasibility and optimize design; and 11) dietary modification shows promise for mitigating emissions. Further research is needed on 1) indoor air quality, barn emissions, thermal conditions, and energy use in alternative hen housing systems (1-story floor, aviary, and enriched cage systems), along with conventional housing systems under different production conditions; 2) environmental footprint for different US egg production systems through life cycle assessment; 3) practical means to mitigate air emissions from different production systems; 4) process-based models for predicting air emissions and their fate; and 5) the interactions between air quality, housing system, worker health, and animal health and welfare.

Gas block mechanism for water removal in fuel cells

DOEpatents

Issacci, Farrokh; Rehg, Timothy J.

2004-02-03

The present invention is directed to apparatus and method for cathode-side disposal of water in an electrochemical fuel cell. There is a cathode plate. Within a surface of the plate is a flow field comprised of interdigitated channels. During operation of the fuel cell, cathode gas flows by convection through a gas diffusion layer above the flow field. Positioned at points adjacent to the flow field are one or more porous gas block mediums that have pores sized such that water is sipped off to the outside of the flow field by capillary flow and cathode gas is blocked from flowing through the medium. On the other surface of the plate is a channel in fluid communication with each porous gas block mediums. The method for water disposal in a fuel cell comprises installing the cathode plate assemblies at the cathode sides of the stack of fuel cells and manifolding the single water channel of each of the cathode plate assemblies to the coolant flow that feeds coolant plates in the stack.

Distribution of PCDD/Fs in the fly ash and atmospheric air of two typical hazardous waste incinerators in eastern China.

PubMed

Chen, Tong; Zhan, Ming-Xiu; Lin, Xiao-Qing; Fu, Jian-Ying; Lu, Sheng-Yong; Li, Xiao-Dong

2015-01-01

Distribution of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) in the fly ash and atmospheric air of one medical waste incinerator (MWI) and one industrial hazardous waste incinerator (IHWI) plants were characterized. The PCDD/F concentrations of the stack gas (fly ash) produced from MWI and IHWI were 17.7 and 0.7 ng international toxic equivalent (I-TEQ)/Nm(3) (4.1 and 2.5 ng I-TEQ/g), respectively. For workplace air, the total concentrations of PCDD/Fs were 11.32 and 0.28 pg I-TEQ/Nm(3) (819.5 and 15.3 pg/Nm(3)). We assumed that the large differences of PCDD/F concentrations in workplace air were due to the differences in chlorine content of the waste, combustion conditions, and other contamination sources. With respect to the homologue profiles, the concentrations of PCDFs decreased with the increase of the substituted chlorine number for each site. Among all of the PCDD/F congeners, 2,3,4,7,8-PeCDF was the most important contributor to the I-TEQ value accounting for ca. 43 % of two sites. The gas/particle partition of PCDD/Fs in the atmosphere of the workplace in the MWI was also investigated, indicating that PCDD/Fs were more associated in the particle phase, especially for the higher chlorinated ones. Moreover, the ratio of the I-TEQ values in particle and gas phase of workplace air was 11.0. At last, the relationship between the distribution of PCDD/Fs in the workplace air and that from stack gas and fly ash was also analyzed and discussed. The high correlation coefficient might be a sign for diffuse gas emissions at transient periods of fumes escaping from the incinerator.

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.

Highly Conductive and Transparent Large-Area Bilayer Graphene Realized by MoCl5 Intercalation.

PubMed

Kinoshita, Hiroki; Jeon, Il; Maruyama, Mina; Kawahara, Kenji; Terao, Yuri; Ding, Dong; Matsumoto, Rika; Matsuo, Yutaka; Okada, Susumu; Ago, Hiroki

2017-11-01

Bilayer graphene (BLG) comprises a 2D nanospace sandwiched by two parallel graphene sheets that can be used to intercalate molecules or ions for attaining novel functionalities. However, intercalation is mostly demonstrated with small, exfoliated graphene flakes. This study demonstrates intercalation of molybdenum chloride (MoCl 5 ) into a large-area, uniform BLG sheet, which is grown by chemical vapor deposition (CVD). This study reveals that the degree of MoCl 5 intercalation strongly depends on the stacking order of the graphene; twist-stacked graphene shows a much higher degree of intercalation than AB-stacked. Density functional theory calculations suggest that weak interlayer coupling in the twist-stacked graphene contributes to the effective intercalation. By selectively synthesizing twist-rich BLG films through control of the CVD conditions, low sheet resistance (83 Ω ▫ -1 ) is realized after MoCl 5 intercalation, while maintaining high optical transmittance (≈95%). The low sheet resistance state is relatively stable in air for more than three months. Furthermore, the intercalated BLG film is applied to organic solar cells, realizing a high power conversion efficiency. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Climatic variability in Princess Elizabeth Land (East Antarctica) over the last 350 years

NASA Astrophysics Data System (ADS)

Ekaykin, Alexey A.; Vladimirova, Diana O.; Lipenkov, Vladimir Y.; Masson-Delmotte, Valérie

2017-01-01

We use isotopic composition (δD) data from six sites in Princess Elizabeth Land (PEL) in order to reconstruct air temperature variability in this sector of East Antarctica over the last 350 years. First, we use the present-day instrumental mean annual surface air temperature data to demonstrate that the studied region (between Russia's Progress, Vostok and Mirny research stations) is characterized by uniform temperature variability. We thus construct a stacked record of the temperature anomaly for the whole sector for the period of 1958-2015. A comparison of this series with the Southern Hemisphere climatic indices shows that the short-term inter-annual temperature variability is primarily governed by the Antarctic Oscillation (AAO) and Interdecadal Pacific Oscillation (IPO) modes of atmospheric variability. However, the low-frequency temperature variability (with period > 27 years) is mainly related to the anomalies of the Indian Ocean Dipole (IOD) mode. We then construct a stacked record of δD for the PEL for the period of 1654-2009 from individual normalized and filtered isotopic records obtained at six different sites (PEL2016 stacked record). We use a linear regression of this record and the stacked PEL temperature record (with an apparent slope of 9 ± 5.4 ‰ °C-1) to convert PEL2016 into a temperature scale. Analysis of PEL2016 shows a 1 ± 0.6 °C warming in this region over the last 3 centuries, with a particularly cold period from the mid-18th to the mid-19th century. A peak of cooling occurred in the 1840s - a feature previously observed in other Antarctic records. We reveal that PEL2016 correlates with a low-frequency component of IOD and suggest that the IOD mode influences the Antarctic climate by modulating the activity of cyclones that bring heat and moisture to Antarctica. We also compare PEL2016 with other Antarctic stacked isotopic records. This work is a contribution to the PAGES (Past Global Changes) and IPICS (International Partnerships in Ice Core Sciences) Antarctica 2k projects.

Determination of herbicides in mineral and stagnant waters at ng/L levels using capillary electrophoresis and UV detection combined with solid-phase extraction and sample stacking.

PubMed

Hernández-Borges, Javier; García-Montelongo, Francisco J; Cifuentes, Alejandro; Rodríguez-Delgado, Miguel Angel

2005-04-08

In this work, the combined use of solid-phase extraction (SPE) and on-line preconcentration strategies as normal stacking mode (NSM) and stacking with matrix removal (SWMR) for the ultrasensitive and simultaneous capillary electrophoresis-ultraviolet analysis (CE-UV) of five triazolopyrimidine sulfonanilide pesticides (i.e., diclosulam, cloransulam-methyl, flumetsulam, metosulam and florasulam) in different types of water is investigated. An adequate separation electrolyte for the separation and stacking of these pesticides was obtained, considering also its compatibility with MS detection, which consisted of 24 mM formic acid and 16 mM ammonium carbonate at pH 6.4. It was observed that the use of this running buffer together with the SWMR preconcentration method provided the best results in terms of sensitivity (between 6.54 and 11.9 microg/L) and peak efficiency (up to 550000 theoretical plates per meter, NTP/m). When this on-line preconcentration procedure was combined with an off-line sample preconcentration step as SPE using C18 cartridges, the selected herbicides could be detected in the ng/L range. The optimized SPE-SWMR-CE-UV method was applied to the determination of the selected group of pesticides in spiked and non-spiked mineral and stagnant waters. Recoveries ranged between 55 and 110% and limits of detection between 131 and 342 ng/L. This work shows the great possibilities of the combined use of SPE-SWMR-CE-UV to overcome the sensitivity problems usually linked to CE analysis.

Stratal stacking patterns and tectono-sedimentary evolution of hyperextended magma-poor rifted margins

NASA Astrophysics Data System (ADS)

Ribes, C.; Gillard, M.; Epin, M. E.; Ghienne, J. F.; Manatschal, G.; Karner, G. D.; Johnson, C. A.

2016-12-01

Research on the formation and evolution of deep-water rifted margins has undergone a major paradigm shift in recent years. An increasing number of studies of present-day and fossil rifted margins allow us to identify and characterize the structural architecture of the most distal parts of rifted margins, the so-called hyperextended, magma-poor rifted margins. However, at present, little is known about the depositional environments, sedimentary facies, stacking patterns, subsidence and thermal history within these domains. In this context, characterizing the stratal stacking patterns and understanding their spatial and temporal evolution is a new challenge. The major difficulty comes from the fact that the observed stratigraphic geometries and facies relationships are a result of the complex interplay between sediment supply and available accommodation, which is controlled by not only the regional generation of accommodation, but also by local tectono-magmatic processes. These parameters are poorly constrained or even sufficiently known in these tectonic settings. Indeed, the complex structural evolution of hyperextended magma-poor rifted margins, including the development of poly-phase in-sequence and out of sequence extensional detachment faults and associated mantle exhumation and magmatic activity, can generate complex accommodation patterns over a highly structured top basement. The presentation summarizes early results concerning the controlling parameters on ultra-deep water stratigraphic stacking patterns and to provide a conceptual framework. This observation-driven approach combines fieldwork from fossil Alpine Tethys margins exposed in the Alps and the analysis of seismic reflection data from present-day deep water rifted margins such as the Australian-Antarctic, East India and Iberia-Newfoundland margins.

Structural and thermodynamic consideration of metal oxide doped GeO{sub 2} for gate stack formation on germanium

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

Lu, Cimang, E-mail: cimang@adam.t.u-tokyo.ac.jp; Lee, Choong Hyun; Zhang, Wenfeng

2014-11-07

A systematic investigation was carried out on the material and electrical properties of metal oxide doped germanium dioxide (M-GeO{sub 2}) on Ge. We propose two criteria on the selection of desirable M-GeO{sub 2} for gate stack formation on Ge. First, metal oxides with larger cation radii show stronger ability in modifying GeO{sub 2} network, benefiting the thermal stability and water resistance in M-GeO{sub 2}/Ge stacks. Second, metal oxides with a positive Gibbs free energy for germanidation are required for good interface properties of M-GeO{sub 2}/Ge stacks in terms of preventing the Ge-M metallic bond formation. Aggressive equivalent oxide thickness scalingmore » to 0.5 nm is also demonstrated based on these understandings.« less

Herschel Far Infrared Spectra of Dusty Star-Forming Galaxies

NASA Astrophysics Data System (ADS)

Wilson, Derek; Cooray, Asantha R.; Nayyeri, Hooshang

2017-01-01

We stack archival spectra from the Herschel Space Observatory's SPIRE Spectrometer in three redshift bins from low redshifts (z < 0.2), through intermediate redshifts (0.2 < z < 1), and up to high redshifts (z > 1) in order to determine the average properties of the gas and dust in dusty, star-forming galaxies and (U)LIRGs. In the lower-redshift stack, we detect a host of water and carbon monoxide rotational transition lines, as well as some fine structure lines such as [NII]. At intermediate redshifts, only a [CII] line appears. The high-redshift stack displays strong [CII] emission, as well as faint emission from [OI] and [OIII]. The observed emission lines are used to model the average number density and radiation field strength in the photodissociation regions of our high-redshift sample, and the spectral line energy distributions of CO rotational transitions from the low-redshift stack are presented.

40 CFR 70.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... section 183(f) of the Act; (11) Any standard or other requirement of the program to control air pollution... emissions which could not reasonably pass through a stack, chimney, vent, or other functionally-equivalent... means any stationary source (or any group of stationary sources that are located on one or more...

40 CFR Table 3 to Subpart Ttttt of... - Initial Compliance With Emission Limits

Code of Federal Regulations, 2011 CFR

2011-07-01

... CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Primary Magnesium...), did not exceed 200 lbs/hr. 2. Each magnesium chloride storage bin scrubber stack a. The average mass flow of hydrochloric acid from the control system applied to the magnesium chloride storage bins...

40 CFR Table 3 to Subpart Ttttt of... - Initial Compliance With Emission Limits

Code of Federal Regulations, 2010 CFR

2010-07-01

... CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Primary Magnesium...), did not exceed 200 lbs/hr. 2. Each magnesium chloride storage bin scrubber stack a. The average mass flow of hydrochloric acid from the control system applied to the magnesium chloride storage bins...

40 CFR Table 3 to Subpart Ttttt of... - Initial Compliance With Emission Limits

Code of Federal Regulations, 2013 CFR

2013-07-01

... CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Primary Magnesium...), did not exceed 200 lbs/hr. 2. Each magnesium chloride storage bin scrubber stack a. The average mass flow of hydrochloric acid from the control system applied to the magnesium chloride storage bins...

40 CFR Table 3 to Subpart Ttttt of... - Initial Compliance With Emission Limits

Code of Federal Regulations, 2012 CFR

2012-07-01

... CATEGORIES (CONTINUED) National Emissions Standards for Hazardous Air Pollutants for Primary Magnesium...), did not exceed 200 lbs/hr. 2. Each magnesium chloride storage bin scrubber stack a. The average mass flow of hydrochloric acid from the control system applied to the magnesium chloride storage bins...

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...

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...

Development of the anode bipolar plate/membrane assembly unit for air breathing PEMFC stack using silicone adhesive bonding

NASA Astrophysics Data System (ADS)

Kim, Minkook; Lee, Dai Gil

2016-05-01

Polymer electrolyte membrane fuel cells (PEMFC) exhibit a wide power range, low operating temperature, high energy density and long life time. These advantages favor PEMFC for applications such as vehicle power sources, portable power, and backup power applications. With the push towards the commercialization of PEMFC, especially for portable power applications, the overall balance of plants (BOPs) of the systems should be minimized. To reduce the mass and complexity of the systems, air-breathing PEMFC stack design with open cathode channel configuration is being developed. However, the open cathode channel configuration incurs hydrogen leakage problem. In this study, the bonding strength of a silicon adhesive between the Nafion membrane and the carbon fiber/epoxy composite bipolar plate was measured. Then, an anode bipolar plate/membrane assembly unit which was bonded with the silicone adhesive was developed to solve the hydrogen leakage problem. The reliability of the anode bipolar plate/membrane assembly unit was estimated under the internal pressure of hydrogen by the FE analysis. Additionally, the gas sealability of the developed air breathing PEMFC unit cell was experimentally measured. Finally, unit cell performance of the developed anode bipolar plate/membrane assembly unit was tested and verified under operating conditions without humidity and temperature control.

Calibration and GEANT4 Simulations of the Phase II Proton Compute Tomography (pCT) Range Stack Detector

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

Uzunyan, S. A.; Blazey, G.; Boi, S.

Northern Illinois University in collaboration with Fermi National Accelerator Laboratory (FNAL) and Delhi University has been designing and building a proton CT scanner for applications in proton treatment planning. The Phase II proton CT scanner consists of eight planes of tracking detectors with two X and two Y coordinate measurements both before and after the patient. In addition, a range stack detector consisting of a stack of thin scintillator tiles, arranged in twelve eight-tile frames, is used to determine the water equivalent path length (WEPL) of each track through the patient. The X-Y coordinates and WEPL are required input formore » image reconstruction software to find the relative (proton) stopping powers (RSP) value of each voxel in the patient and generate a corresponding 3D image. In this Note we describe tests conducted in 2015 at the proton beam at the Central DuPage Hospital in Warrenville, IL, focusing on the range stack calibration procedure and comparisons with the GEANT~4 range stack simulation.« less

Compact gasoline fuel processor for passenger vehicle APU

NASA Astrophysics Data System (ADS)

Severin, Christopher; Pischinger, Stefan; Ogrzewalla, Jürgen

Due to the increasing demand for electrical power in today's passenger vehicles, and with the requirements regarding fuel consumption and environmental sustainability tightening, a fuel cell-based auxiliary power unit (APU) becomes a promising alternative to the conventional generation of electrical energy via internal combustion engine, generator and battery. It is obvious that the on-board stored fuel has to be used for the fuel cell system, thus, gasoline or diesel has to be reformed on board. This makes the auxiliary power unit a complex integrated system of stack, air supply, fuel processor, electrics as well as heat and water management. Aside from proving the technical feasibility of such a system, the development has to address three major barriers:start-up time, costs, and size/weight of the systems. In this paper a packaging concept for an auxiliary power unit is presented. The main emphasis is placed on the fuel processor, as good packaging of this large subsystem has the strongest impact on overall size. The fuel processor system consists of an autothermal reformer in combination with water-gas shift and selective oxidation stages, based on adiabatic reactors with inter-cooling. The configuration was realized in a laboratory set-up and experimentally investigated. The results gained from this confirm a general suitability for mobile applications. A start-up time of 30 min was measured, while a potential reduction to 10 min seems feasible. An overall fuel processor efficiency of about 77% was measured. On the basis of the know-how gained by the experimental investigation of the laboratory set-up a packaging concept was developed. Using state-of-the-art catalyst and heat exchanger technology, the volumes of these components are fixed. However, the overall volume is higher mainly due to mixing zones and flow ducts, which do not contribute to the chemical or thermal function of the system. Thus, the concept developed mainly focuses on minimization of those component volumes. Therefore, the packaging utilizes rectangular catalyst bricks and integrates flow ducts into the heat exchangers. A concept is presented with a 25 l fuel processor volume including thermal isolation for a 3 kW el auxiliary power unit. The overall size of the system, i.e. including stack, air supply and auxiliaries can be estimated to 44 l.

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

Mobility of rare earth elements, yttrium and scandium from a phosphogypsum stack: Environmental and economic implications.

PubMed

Cánovas, Carlos Ruiz; Macías, Francisco; Pérez López, Rafael; Nieto, José Miguel

2018-03-15

This paper investigates the mobility and fluxes of REE, Y and Sc under weathering conditions from an anomalously metal-rich phosphogypsum stack in SW Spain. The interactions of the phosphogypsum stack with rainfall and organic matter-rich solutions, simulating the weathering processes observed due to its location on salt-marshes, were simulated by leaching tests (e.g. EN 12457-2 and TCLP). Despite the high concentration of REE, Y and Sc contained in the phosphogypsum stack, their mobility during the leaching tests was very low; <0.66% and 1.8% of the total content of these elements were released during both tests. Chemical and mineralogical evidences suggest that phosphate minerals may act as sources of REE and Y in the phosphogypsum stack while fluoride minerals may act as sinks, controlling their mobility. REE fractionation processes were identified in the phosphogypsum stack; a depletion of LREE in the saturated zone was identified due probably to the dissolution of secondary LREE phosphates previously formed during apatite dissolution in the industrial process. Thus, the vadose zone of the stack would preserve the original REE signature of phosphate rocks. On the other hand, an enrichment of MREE in relation to HREE of edge outflows is observed due to the higher influence of estuarine waters on the leaching process of the phosphogypsum stack. Despite the low mobility of REE, Y and Sc in the phosphogypsum, around 104kg/yr of REE and 40kg/yr of Y and Sc are released from the stack to the estuary, which may imply an environmental concern. The information obtained in this study could be used to optimize extraction methods aimed to recover REE, Y and Sc from phosphogypsum, mitigating the pollution to the environment. Copyright © 2017 Elsevier B.V. All rights reserved.

Comprehensive assessment of toxic emissions from coal-fired power plants

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

Brown, T D; Schmidt, C E; Radziwon, A S

1991-01-01

The Pittsburgh Energy Technology Center (PETC) of the US Department of Energy (DOE) has two current investigations, initiated before passage of the Clean Air Act Amendment (CAAA), that will determine the air toxic emissions from coal-fired electric utilities. DOE has contracted with Battelle Memorial Institute and Radian corporation to conduct studies focusing on the potential air toxics, both organic and inorganic, associated with different size fractions of fine particulate matter emitted from power plant stacks. Table 2 indicates the selected analytes to be investigated during these studies. PETC is also developing guidance on the monitoring of Hazardous Air Pollutants (HAPS)more » to be incorporated in the Environmental Monitoring plans for the demonstration projects in its Clean Coal Technology Program.« less

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

NONE

Under contract with the US Department of Energy (DE-AC22-92PCO0367), Pittsburgh Energy Technology Center, Radian Corporation has conducted a test program to collect and analyze size-fractionated stack gas particulate samples for selected inorganic hazardous air pollutants (HAPS). Specific goals of the program are (1) the collection of one-gram quantities of size-fractionated stack gas particulate matter for bulk (total) and surface chemical charactization, and (2) the determination of the relationship between particle size, bulk and surface (leachable) composition, and unit load. The information obtained from this program identifies the effects of unit load, particle size, and wet FGD system operation on themore » relative toxicological effects of exposure to particulate emissions.« less

Experimental Determination of Exhaust Gas Thrust, Special Report

NASA Technical Reports Server (NTRS)

Pinkel, Benjamin; Voss, Fred

1940-01-01

This investigation presents the results of tests made on a radial engine to determine the thrust that can be obtained from the exhaust gas when discharged from separate stacks and when discharged from the collector ring with various discharge nozzles. The engine was provided with a propeller to absorb the power and was mounted on a test stand equipped with scales for measuring the thrust and engine torque. The results indicate that at full open throttle at sea level, for the engine tested, a gain in thrust horsepower of 18 percent using separate stacks, and 9.5 percent using a collector ring and discharge nozzle, can be expected at an air speed of 550 miles per hour.

Deep learning architecture for air quality predictions.

PubMed

Li, Xiang; Peng, Ling; Hu, Yuan; Shao, Jing; Chi, Tianhe

2016-11-01

With the rapid development of urbanization and industrialization, many developing countries are suffering from heavy air pollution. Governments and citizens have expressed increasing concern regarding air pollution because it affects human health and sustainable development worldwide. Current air quality prediction methods mainly use shallow models; however, these methods produce unsatisfactory results, which inspired us to investigate methods of predicting air quality based on deep architecture models. In this paper, a novel spatiotemporal deep learning (STDL)-based air quality prediction method that inherently considers spatial and temporal correlations is proposed. A stacked autoencoder (SAE) model is used to extract inherent air quality features, and it is trained in a greedy layer-wise manner. Compared with traditional time series prediction models, our model can predict the air quality of all stations simultaneously and shows the temporal stability in all seasons. Moreover, a comparison with the spatiotemporal artificial neural network (STANN), auto regression moving average (ARMA), and support vector regression (SVR) models demonstrates that the proposed method of performing air quality predictions has a superior performance.

Franckeite as a naturally occurring van der Waals heterostructure

PubMed Central

Molina-Mendoza, Aday J.; Giovanelli, Emerson; Paz, Wendel S.; Niño, Miguel Angel; Island, Joshua O.; Evangeli, Charalambos; Aballe, Lucía; Foerster, Michael; van der Zant, Herre S. J.; Rubio-Bollinger, Gabino; Agraït, Nicolás; Palacios, J. J.; Pérez, Emilio M.; Castellanos-Gomez, Andres

2017-01-01

The fabrication of van der Waals heterostructures, artificial materials assembled by individual stacking of 2D layers, is among the most promising directions in 2D materials research. Until now, the most widespread approach to stack 2D layers relies on deterministic placement methods, which are cumbersome and tend to suffer from poor control over the lattice orientations and the presence of unwanted interlayer adsorbates. Here, we present a different approach to fabricate ultrathin heterostructures by exfoliation of bulk franckeite which is a naturally occurring and air stable van der Waals heterostructure (composed of alternating SnS2-like and PbS-like layers stacked on top of each other). Presenting both an attractive narrow bandgap (<0.7 eV) and p-type doping, we find that the material can be exfoliated both mechanically and chemically down to few-layer thicknesses. We present extensive theoretical and experimental characterizations of the material's electronic properties and crystal structure, and explore applications for near-infrared photodetectors. PMID:28194037

Insight into unusual impurity absorbability of GeO(2) in GeO(2)∕Ge stacks.

PubMed

Ogawa, Shingo; Suda, Taichi; Yamamoto, Takashi; Kutsuki, Katsuhiro; Hideshima, Iori; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji

2011-10-03

Adsorbed species and its diffusion behaviors in GeO(2)∕Ge stacks, which are future alternative metal-oxide-semiconductor (MOS) materials, have been investigated using various physical analyses. We clarified that GeO(2) rapidly absorbs moisture in air just after its exposure. After the absorbed moisture in GeO(2) reaches a certain limit, the GeO(2) starts to absorb some organic molecules, which is accompanied by a structural change in GeO(2) to form a partial carbonate or hydroxide. We also found that the hydrogen distribution in GeO(2) shows intrinsic characteristics, indicative of different diffusion behaviors at the surface and at the GeO(2)∕Ge interface. Because the impurity absorbability of GeO(2) has a great influence on the electrical properties in Ge-MOS devices, these results provide valuable information in realizing high quality GeO(2)∕Ge stacks for the actual use of Ge-MOS technologies.

Air pollution from gas flaring: new emission factor estimates and detection in a West African aerosol remote-sensing climatology

NASA Astrophysics Data System (ADS)

MacKenzie, Rob; Fawole, Olusegun Gabriel; Levine, James; Cai, Xiaoming

2016-04-01

Gas flaring, the disposal of gas through stacks in an open-air flame, is a common feature in the processing of crude oil, especially in oil-rich regions of the world. Gas flaring is a prominent source of volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAH), CO, CO2, nitrogen oxides (NOx), SO2 (in "sour" gas only), and soot (black carbon), as well as the release of locally significant amounts of heat. The rates of emission of these pollutants from gas flaring depend on a number of factors including, but not limited to, fuel composition and quantity, stack geometry, flame/combustion characteristics, and prevailing meteorological conditions. Here, we derive new estimated emission factors (EFs) for carbon-containing pollutants (excluding PAH). The air pollution dispersion model, ADMS5, is used to simulate the dispersion of the pollutants from flaring stacks in the Niger delta. A seasonal variation of the dispersion pattern of the pollutant within a year is studied in relation to the movements of the West Africa Monsoon (WAM) and other prevailing meteorological factors. Further, we have clustered AERONET aerosol signals using trajectory analysis to identify dominant aerosol sources at the Ilorin site in West Africa (4.34 oE, 8.32 oN). A 10-year trajectory-based analysis was undertaken (2005-2015, excluding 2010). Of particular interest are air masses that have passed through the gas flaring region in the Niger Delta area en-route the AERONET site. 7-day back trajectories were calculated using the UK Universities Global Atmospheric Modelling Programme (UGAMP) trajectory model which is driven by analyses from the European Centre for Medium-Range Weather Forecasts (ECMWF). From the back-trajectory calculations, dominant sources are identified, using literature classifications: desert dust (DD); Biomass burning (BB); and Urban-Industrial (UI). We use a combination of synoptic trajectories and aerosol optical properties to distinguish a fourth source: that due to gas flaring. We discuss the relative impact of these different aerosol sources on the overall radiative forcing at Ilorin AERONET site.

A ten liter stacked microbial desalination cell packed with mixed ion-exchange resins for secondary effluent desalination.

PubMed

Zuo, Kuichang; Cai, Jiaxiang; Liang, Shuai; Wu, Shijia; Zhang, Changyong; Liang, Peng; Huang, Xia

2014-08-19

The architecture and performance of microbial desalination cell (MDC) have been significantly improved in the past few years. However, the application of MDC is still limited in a scope of small-scale (milliliter) reactors and high-salinity-water desalination. In this study, a large-scale (>10 L) stacked MDC packed with mixed ion-exchange resins was fabricated and operated in the batch mode with a salt concentration of 0.5 g/L NaCl, a typical level of domestic wastewater. With circulation flow rate of 80 mL/min, the stacked resin-packed MDC (SR-MDC) achieved a desalination efficiency of 95.8% and a final effluent concentration of 0.02 g/L in 12 h, which is comparable with the effluent quality of reverse osmosis in terms of salinity. Moreover, the SR-MDC kept a stable desalination performance (>93%) when concentrate volume decreased from 2.4 to 0.1 L (diluate/concentrate volume ratio increased from 1:1 to 1:0.04), where only 0.875 L of nonfresh water was consumed to desalinate 1 L of saline water. In addition, the SR-MDC achieved a considerable desalination rate (95.4 mg/h), suggesting a promising application for secondary effluent desalination through deriving biochemical electricity from wastewater.

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

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.

WATER MASERS IN THE ANDROMEDA GALAXY. I. A SURVEY FOR WATER MASERS, AMMONIA, AND HYDROGEN RECOMBINATION LINES

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

Darling, Jeremy; Gerard, Benjamin; Amiri, Nikta

We report the results of a Green Bank Telescope survey for water masers, ammonia (1, 1) and (2, 2), and the H66 α recombination line toward 506 luminous compact 24 μ m emitting regions in the Andromeda Galaxy (M31). We include the 206 sources observed in the Darling water maser survey for completeness. The survey was sensitive enough to detect any maser useful for ∼10 μ as yr{sup 1} astrometry. No new water masers, ammonia lines, or H66 α recombination lines were detected individually or in spectral stacks reaching rms noise levels of ∼3 mJy and ∼0.2 mJy, respectively, inmore » 3.1–3.3 km s{sup 1} channels. The lack of detections in individual spectra and in the spectral stacks is consistent with Galactic extrapolations. Contrary to previous assertions, there do not seem to be any additional bright water masers to be found in M31. The strong variability of water masers may enable new maser detections in the future, but variability may also limit the astrometric utility of known (or future) masers because flaring masers must also fade.« less