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Sample records for stack sampling technical

  1. 40 CFR 61.44 - Stack sampling.

    Science.gov (United States)

    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...

  2. 40 CFR 61.53 - Stack sampling.

    Science.gov (United States)

    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...

  3. 40 CFR 61.33 - Stack sampling.

    Science.gov (United States)

    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...

  4. Contemporary sample stacking in analytical electrophoresis.

    Science.gov (United States)

    Malá, Zdena; Šlampová, Andrea; Křivánková, Ludmila; Gebauer, Petr; Boček, Petr

    2015-01-01

    This contribution is a methodological review of the publications about the topic from the last 2 years. Therefore, it is primarily organized according to the methods and procedures used in surveyed papers and the origin and type of sample and specification of analytes form the secondary structure. The introductory part about navigation in the architecture of stacking brings a brief characterization of the various stacking methods, with the description of mutual links to each other and important differences among them. The main body of the article brings a survey of publications organized according to main principles of stacking and then according to the origin and type of the sample. Provided that the paper cited gave explicitly the relevant data, information about the BGE(s) used, procedure, detector employed, and reached LOD and/or concentration effect is given. The papers where the procedure used is a combination of diverse fragments and parts of various stacking techniques are mentioned in a special section on combined techniques. The concluding remarks in the final part of the review evaluate present state of art and the trends of sample stacking in CE. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Contemporary sample stacking in analytical electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Šlampová, Andrea; Malá, Zdeňka; Pantůčková, Pavla; Gebauer, Petr; Boček, Petr

    2013-01-01

    Roč. 34, č. 1 (2013), s. 3-18 ISSN 0173-0835 R&D Projects: GA ČR GAP206/10/1219 Institutional support: RVO:68081715 Keywords : biological samples * stacking * trace analysis * zone electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.161, year: 2013

  6. Contemporary sample stacking in analytical electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Malá, Zdeňka; Šlampová, Andrea; Křivánková, Ludmila; Gebauer, Petr; Boček, Petr

    2015-01-01

    Roč. 36, č. 1 (2015), s. 15-35 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : biological samples * stacking * trace analysis * zone electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.482, year: 2015

  7. Contemporary sample stacking in analytical electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Malá, Zdeňka; Gebauer, Petr; Boček, Petr

    2011-01-01

    Roč. 32, č. 1 (2011), s. 116-126 ISSN 0173-0835 R&D Projects: GA ČR GA203/08/1536; GA ČR GAP206/10/1219; GA AV ČR IAA400310703 Institutional research plan: CEZ:AV0Z40310501 Keywords : biological samples * stacking * trace analysis * zone electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.303, year: 2011

  8. Sampled-time control of a microbial fuel cell stack

    Science.gov (United States)

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

    2017-07-01

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

  9. 296-B-5 Stack monitoring and sampling system annual system assessment report

    International Nuclear Information System (INIS)

    Ridge, T.M.

    1995-02-01

    The B Plant Administration Manual requires an annual system assessment to evaluate and report the present condition of the sampling and monitoring system associated with Stack 296-B-5 at B Plant. The sampling and monitoring system associated with stack 296-B-5 is functional and performing satisfactorily. This document is an annual assessment report of the systems associated with the 296-B-5 stack

  10. 296-B-10 stack monitoring and sampling system annual system assessment report

    International Nuclear Information System (INIS)

    Ridge, T.M.

    1995-01-01

    B Plant Administration Manual, requires an annual system assessment to evaluate and report the present condition of the sampling and monitoring system associated with stack 296-B-10 at B Plant. The ventilation system of WESF (Waste Encapsulation and Storage Facility) is designed to provide airflow patterns so that air movement throughout the building is from areas of lesser radioactivity to areas of greater radioactivity. All potentially contaminated areas are maintained at a negative pressure with respect to the atmosphere so that air flows into the building at all times. The exhaust discharging through the 296-B-10 stack is continuously monitored and sampled using a sampling and monitoring probe assembly located approximately 17.4 meters (57 feet) above the base of the stack. The probe assembly consists of 5 nozzles for the sampling probe and 2 nozzles to monitor the flow. The sampling and monitoring system associated with Stack 296-B-10 is functional and performing satisfactorily

  11. Experimental verification of air flow rate measurement for representative isokinetic air sampling in ventilation stacks

    International Nuclear Information System (INIS)

    Okruhlica, P.; Mrtvy, M.; Kopecky, Z.

    2008-01-01

    Nuclear facilities are obliged to monitor their discharge's influence on environment. Main monitored factions in NPP's ventilation stacks are usually noble gasses, particulates and iodine. These factions are monitored in air sampled from ventilation stack by means of sampling rosette and bypass followed with on-line measuring monitors and balance sampling devices with laboratory evaluations. Correct air flow rate measurement and representative iso-kinetic air sampling system is essential for physical correct and metrological accurate evaluation of discharge influence on environment. Pairs of measuring sensors (Anemometer, pressure gauge, thermometer and humidity meter) are symmetrically placed in horizontal projection of stack on positions based on measured air flow velocity distribution characteristic, Analogically diameter of sampling rosette nozzles and their placement in the middle of 6- 7 annuluses are calculated for assurance of representative iso-kinetic sampling. (authors)

  12. Review of the Physical Science Facility Stack Air Sampling Probe Locations

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, John A.

    2007-09-30

    This letter report reviews compliance of the current design of the Physical Science Facility (PSF) stack air sampling locations with the ANSI/HPS N13.1-1999 standard. The review was based on performance criteria used for locating air sampling probes, the design documents provided and available information on systems previously tested for compliance with the criteria. Recommendations are presented for ways to bring the design into compliance with the requirements for the sampling probe placement.

  13. Single point aerosol sampling: Evaluation of mixing and probe performance in a nuclear stack

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, J.C.; Fairchild, C.I.; Wood, G.O. [Los Alamos National Laboratory, NM (United States)] [and others

    1995-02-01

    Alternative Reference Methodologies (ARMs) have been developed for sampling of radionuclides from stacks and ducts that differ from the methods required by the U.S. EPA. The EPA methods are prescriptive in selection of sampling locations and in design of sampling probes whereas the alternative methods are performance driven. Tests were conducted in a stack at Los Alamos National Laboratory to demonstrate the efficacy of the ARMs. Coefficients of variation of the velocity tracer gas, and aerosol particle profiles were determined at three sampling locations. Results showed numerical criteria placed upon the coefficients of variation by the ARMs were met at sampling stations located 9 and 14 stack diameters from flow entrance, but not at a location that is 1.5 diameters downstream from the inlet. Experiments were conducted to characterize the transmission of 10 {mu}m aerodynamic equivalent diameter liquid aerosol particles through three types of sampling probes. The transmission ratio (ratio of aerosol concentration at the probe exit plane to the concentration in the free stream) was 107% for a 113 L/min (4-cfm) anisokinetic shrouded probe, but only 20% for an isokinetic probe that follows the EPA requirements. A specially designed isokinetic probe showed a transmission ratio of 63%. The shrouded probe performance would conform to the ARM criteria; however, the isokinetic probes would not.

  14. An assessment of air sampling location for stack monitoring in nuclear facility

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Bok [University of Science and Technology, Daejeon (Korea, Republic of); Kim, Tae Hyoung; Lee, Jong Il; Kim, Bong Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-06-15

    In this study, air sampling locations in the stack of the Advanced Fuel Science Building (AFSB) at the Korea Atomic Energy Research Institute (KAERI) were assessed according to the ANSI/HPS N13.1-1999 specification. The velocity profile, flow angle and 10 μm aerosol particle profile at the cross-section as functions of stack height L and stack diameter D (L/D) were assessed according to the sampling location criteria using COMSOL. The criteria for the velocity profile were found to be met at 5 L/D or more for the height, and the criteria for the average flow angle were met at all locations through this assessment. The criteria for the particle profile were met at 5 L/D and 9 L/D. However, the particle profile at the cross-section of each sampling location was found to be non-uniform. In order to establish uniformity of the particle profile, a static mixer and a perimeter ring were modeled, after which the degrees of effectiveness of these components were compared. Modeling using the static mixer indicated that the sampling locations that met the criteria for the particle profile were 5-10 L/D. When modeling using the perimeter ring, the sampling locations that met the criteria for particle profile were 5 L/D and 7-10 L/D. The criteria for the velocity profile and the average flow angle were also met at the sampling locations that met the criteria for the particle profile. The methodologies used in this study can also be applied during assessments of air sampling locations when monitoring stacks at new nuclear facilities as well as existing nuclear facilities.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiao-Ying [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Recknagle, Kurtis P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    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 criteria 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

  16. Aerosol sampling from stacks and ducts at the Rocky Flats Plant

    International Nuclear Information System (INIS)

    McFarlane, A.R.; Anand, N.K.; Ortiz, C.A.

    1995-01-01

    While the Rocky Flats Plant (RFP) in Golden, CO is being decommissioned; there is air flow through the ventilation systems in the buildings. Although the air is HEPA filtered, under the requirements of both the U.S. EPA and the U.S. DOE, several of the stacks and ducts must be continuously monitored for radionuclide aerosol particles, where plutonium is the principal radionuclide of concern. The air sampling effort for compliance with EPA requirements is focussed on the acquisition of representative aerosol samples, which are collected on filters and subsequently analyzed in a laboratory. The goal of the DOE sampling is to acquire representative samples that can be analyzed with near-real-time monitors for alarming purposes, where the alarms are used to warn workers that may be affected by elevated concentrations of radionuclides. The air sampling at RFP is based on single point representative sampling with a shrouded probe. For stacks and ducts that are under the cognizance of EPA, the approach is embodied in a set of Alternate Reference Methodologies that EPA has approved for use at DOE facilities. Shrouded probes were designed based on numerical predictions of performance and the efficacy of the probes was verified by wind tunnel tests. Aerosol transport lines were designed using a code, DEPOSITION that provides optimization of aerosol penetration. Adequacy of a location for single point sampling was based on numerical criteria for mixing of both contaminant mass and fluid momentum as manifested by the uniformity of the velocity profile and the profiles of tracer gas and aerosol particles. Scale models were constructed of key ducts and these were tested in the laboratory to determine the proper locations. For ducts and stacks that fall under DOE, but not EPA requirements, similar methodology was used; however, the single point sampling location is based on alarming considerations

  17. 291-B-1 stack monitoring and sampling system annual system assessment report

    International Nuclear Information System (INIS)

    Ridge, T.M.

    1994-01-01

    The B Plant 291-B-1 main stack exhausts gaseous effluents to the atmosphere from the 221-B Building canyon and cells, the No. 1 Vessel Ventilation System (VVS1), the 212-B Cask Station cell ventilation system, and, to a limited capacity, the 224-B Building. VVS1 collects offgases from various process tanks in 221-B Building, while the 224-B system maintains a negative pressure in out-of-service, sealed process tanks. B Plant Administration Manual, WHC-CM-7-5, Section 5.30 requires an annual system assessment to evaluate and report the present condition of the sampling and monitoring system associated with Stack 291-B-1 (System Number B977A) at B Plant. The system is functional and performing satisfactorily

  18. Sampling of power plant stacks for air toxic emissions: Topical report for Phases 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-21

    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 the relative toxicological effects of exposure to particulate emissions.

  19. Sampling of power plant stacks for air toxic emissions: Final report for Phases 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-04-28

    A test program to collect and analyze size-fractionated stack gas particulate samples for selected inorganic hazardous air pollutants (HAPs) was conducted . 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 characterization, 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 the relative toxicological effects of exposure to particulate emissions. Field testing was conducted in two phases. The Phase I field program was performed over the period of August 24 through September 20, 1992, at the Tennessee Valley Authority Widows Creek Unit 8 Power Station, located near Stevenson (Jackson County), Alabama, on the Tennessee River. Sampling activities for Phase II were conducted from September 11 through October 14, 1993. Widows Creek Unit 8 is a 575-megawatt plant that uses bituminous coal averaging 3.7% sulfur and 13% ash. Downstream of the boiler, a venture wet scrubbing system is used for control of both sulfur dioxide and particulate emissions. There is no electrostatic precipitator (ESP) in this system. This system is atypical and represents only about 5% of the US utility industry. However, this site was chosen for this study because of the lack of information available for this particulate emission control system.

  20. Characterization of cotton gin PM10 emissions based on EPA stack sampling methodologies and particle size distributions

    Science.gov (United States)

    A project to characterize cotton gin emissions in terms of stack sampling was conducted during the 2008 through 2011 ginning seasons. The impetus behind the project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. EPA AP-42 emission factors ar...

  1. Recent progress of sample stacking in capillary electrophoresis (2014–2016)

    Czech Academy of Sciences Publication Activity Database

    Šlampová, Andrea; Malá, Zdeňka; Gebauer, Petr; Boček, Petr

    2017-01-01

    Roč. 38, č. 1 (2017), s. 20-32 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA16-09135S Institutional support: RVO:68081715 Keywords : stacking * zone electrophoresis * trace analysis * review Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 2.744, year: 2016

  2. Preliminary evaluation of the gaseous effluent sampling system at the 296-S-18 stack, 242-S evaporator

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, J.A.; Schwendiman, L.C.

    1977-04-01

    This evaluation of the 296-S-18 stack sampling system is part of a larger study, sponsored by ARHCO and conducted by Battelle-Northwest, of gaseous effluent sampling systems in ARHCO facilities. It is the fourth and last in a series of evaluations of tank farm stack sampling systems. The objectives of this study are: Evaluate the compliance of the existing effluent particulate sampling system with ARHCO's Interim Criteria for such systems by using sampling theory and radioactivity counting statistics; and make recommendations for corrective action which will lead to a particulate sampling system in compliance with the Interim Criteria. This study is considered preliminary because no experiments have been conducted to verify the sampling system's performance. The following report includes a brief summary, a detailed description and evaluation of the sampling system, conclusions about satisfactory or deficient areas of the sampling system and recommendations for corrective action. The appendices contain a copy of the Interim Criteria and the applicable ARHCO Emergency Procedure for radioactive gaseous discharges.

  3. Preliminary evaluation of the gaseous effluent sampling system at the 296-S-18 stack, 242-S evaporator

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, J.A.; Schwendiman, L.C.

    1977-04-01

    This evaluation of the 296-S-18 stack sampling system is part of a larger study, sponsored by ARHCO and conducted by Battelle-Northwest, of gaseous effluent sampling systems in ARHCO facilities. It is the fourth and last in a series of evaluations of tank farm stack sampling systems. The objectives of this study are: Evaluate the compliance of the existing effluent particulate sampling system with ARHCO`s Interim Criteria for such systems by using sampling theory and radioactivity counting statistics; and make recommendations for corrective action which will lead to a particulate sampling system in compliance with the Interim Criteria. This study is considered preliminary because no experiments have been conducted to verify the sampling system`s performance. The following report includes a brief summary, a detailed description and evaluation of the sampling system, conclusions about satisfactory or deficient areas of the sampling system and recommendations for corrective action. The appendices contain a copy of the Interim Criteria and the applicable ARHCO Emergency Procedure for radioactive gaseous discharges.

  4. Measurement of the Tracer Gradient and Sampling System Bias of the Hot Fuel Examination Facility Stack Air Monitoring System

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, John A.; Flaherty, Julia E.

    2011-07-20

    This report describes tracer gas uniformity and bias measurements made in the exhaust air discharge of the Hot Fuel Examination Facility at Idaho National Laboratory. The measurements were a follow-up on earlier measurements which indicated a lack of mixing of the two ventilation streams being discharged via a common stack. The lack of mixing is detrimental to the accuracy of air emission measurements. The lack of mixing was confirmed in these new measurements. The air sampling probe was found to be out of alignment and that was corrected. The suspected sampling bias in the air sample stream was disproved.

  5. System effects in sample self-stacking CZE: Single analyte peak splitting of salt-containing samples

    Czech Academy of Sciences Publication Activity Database

    Malá, Zdeňka; Gebauer, Petr; Boček, Petr

    2009-01-01

    Roč. 30, č. 5 (2009), s. 866-874 ISSN 0173-0835 R&D Projects: GA ČR GA203/08/1536; GA AV ČR IAA400310609; GA AV ČR IAA400310703 Institutional research plan: CEZ:AV0Z40310501 Keywords : CZE * peak splitting * self-stacking Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.077, year: 2009

  6. Technical Evaluation of Sample-Processing, Collection, and Preservation Methods

    Science.gov (United States)

    2014-07-01

    policy document entitled The National Strategy for Biosurveillance was released (White House, July 2012) as part of the National Security Strategy...concept of leveraging existing capabilities to “scan and discern the environment,” which implies the use of current technical biosurveillance ...testing of existing sample-processing technologies are expected to enable in silico evaluations of biosurveillance methodologies, equipment, and

  7. Confirmation of vanadium complex formation using electrospray mass spectrometry and determination of vanadium speciation by sample stacking capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Chen Zuliang [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia)]. E-mail: zuliang.chen@unisa.edu.au; Owens, Gary [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Naidu, Ravendra [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); CRC for Contamination Assessment and Remediation of Environments, Mawson Lakes Boulevard, Mawson Lakes, SA 5095 (Australia)

    2007-02-28

    Capillary zone electrophoresis (CZE) with UV detection was used to determine vanadium species. Nitrilotriacetic acid (NTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), ethylene glycol-bis(2-aminoethylether)-tetraacetic acid (EGTA) and 2,6-pyridinedicarboxylic acid (PDCA) were investigated to determine whether these ligands formed stable anionic complexes with vanadium. Of all the ligands studied HEDTA was the most suitable ligand because it gave the largest UV response with reasonable migration time. Electrospray mass spectrometry (ES-MS) was used to confirm the formation of [VO{sub 2}(HEDTA)]{sup 2-} and [VO(HEDTA)]{sup 1-} in solution. An electrolyte containing 25 mM phosphate, 0.25 mM tetradecyltrimethylammonium bromide (TTAB) at pH 5.5 was optimum for the separation of these anionic vanadium complexes. Sample stacking techniques, including large-volume sample stacking (LVSS) and field-amplified sample injection (FASI), were tested to improve the sensitivity. Best sensitivity was obtained using FASI, with detection limits of 0.001 {mu}M, equivalent to 0.4 {mu}g L{sup -1}, for [VO{sub 2}(HEDTA)]{sup 2-} and 0.01 {mu}M, equivalent to 3.4 {mu}g L{sup -1} for [VO(HEDTA)]{sup 1-}. The utility of the method for the speciation of V(IV) and V(V) was demonstrated using ground water samples.

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

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Antonio, Ernest J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    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 probe 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.

  9. CO2utilization via a novel anaerobic bioprocess configuration with simulated gas mixture and real stack gas samples.

    Science.gov (United States)

    Daglioglu, S Tugce; Karabey, Burcin; Ozdemir, Guven; Azbar, Nuri

    2017-11-28

    CO 2 , which is considered to be one of the major causes of climate change, has reached to critical levels in the atmosphere due to tremendous consumption of fossil fuels all over the world. In this study, anaerobic bioconversion of CO 2 into bio-methane using a novel bioprocess configuration (HYBRID bioreactor) was studied under mesophilic conditions. Varying ratios of H 2 /CO 2 gas mixture and volumetric feeding rates were investigated and no additional organic matter and trace element were needed throughout the study. The maximum methane production of 19 m 3 CH 4 /m 3 reactor/ d was achieved at a H 2 /CO 2 ratio of 4:1 and feeding rate of 24 m 3 gas/m 3 reactor /d. It was determined that H 2 conversion rate is about 96%. For demonstration purpose, real stack gas sample from a petrochemical industry was also tested under optimized operational conditions. No inhibitory effect from stack gas mixture was observed. This study provided an environmentally friendly and sustainable solution for industries such as petrochemical industry in order to produce extra energy while capturing their waste CO 2 . Thereby, a sustainable and environmentally friendly model solution was presented for industries with high CO 2 emissions. COV: coefficient of variation; Gt: gigatone; IEA: International Energy Agency; IPCC: International Panel on Climate Change; MBBR: moving bed biofilm reactor; MJ: Megajoule; UASB: upflow anaerobic sludge blanket; VFR: volumetric feeding rate.

  10. Sensitive determination of pyrrolizidine alkaloids in Tussilago farfara L. by field-amplified, sample-stacking, sweeping micellar electrokinetic chromatography.

    Science.gov (United States)

    Cao, Kun; Xu, Yi; Mu, Xiuni; Zhang, Qing; Wang, Renjie; Lv, Junjiang

    2016-11-01

    Pyrrolizidine alkaloids are the toxic components in Tussilago farfara L. Due to the lack of standard substances for quantitative analysis and traces of pyrrolizidine alkaloids in total alkaloids, the full quality control of Tussilago farfara L has been limited. In this study, we aimed to solve the difficulty of determination of pyrrolizidine alkaloids and identify more components in the total alkaloids. An on-line preconcentration method has been applied to improve determining sensitivity of pyrrolizidine alkaloids in Tussilago farfara L. in which included field-amplified sample stacking and sweeping in micellar electrokinetic capillary chromatography. The main parameters that affected separation and stacking efficiency were investigated in details. Under the optimal conditions, the sensitivity enhancement factors obtained by the developed method for the analytes were from 15- to 12-fold, the limits of detection of senkirkine and senecionine were 2∼5 μg/L. Senkirkine and senecionine have been detected in alkaloids (c) of Tussilago farfara L, along ferulic acid methyl ester and methyl caffeate. The developed method was also applied to the analysis of acid extraction (a) of Tussilago farfara L, and senkirkine could be detected directly. The results indicated that the developed method is feasible for the analysis of pyrrolizidine alkaloids in Tussilago farfara L with good recoveries. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Field-amplified sample stacking capillary electrophoresis with electrochemiluminescence applied to the determination of illicit drugs on banknotes.

    Science.gov (United States)

    Xu, Yuanhong; Gao, Ying; Wei, Hui; Du, Yan; Wang, Erkang

    2006-05-19

    Capillary electrophoresis (CE) with Ru(bpy)3(2+) electrochemiluminescence (ECL) detection system was established to the determination of contamination of banknotes with controlled drugs and a high efficiency on-column field-amplified sample stacking (FASS) technique was also optimized to increase the ECL intensity. The method was illustrated using heroin and cocaine, which are two typical and popular illicit drugs. Highest sample stacking was obtained when 0.01 mM acetic acid was chosen for sample dissolution with electrokinetical injection for 6 s at 17 kV. Under the optimized conditions: ECL detection at 1.2 V, separation voltage 10.0 kV, 20 mM phosphate-acetate (pH 7.2) as running buffer, 5 mM Ru(bpy)3(2+) with 50 mM phosphate-acetate (pH 7.2) in the detection cell, the standard curves were linear in the range of 7.50x10(-8) to 1.00x10(-5) M for heroin and 2.50x10(-7) to 1.00x10(-4) M for cocaine and detection limits of 50 nM for heroin and 60 nM for cocaine were achieved (S/N = 3), respectively. Relative standard derivations of the ECL intensity and the migration time were 3.50 and 0.51% for heroin and 4.44 and 0.12% for cocaine, respectively. The developed method was successfully applied to the determination of heroin and cocaine on illicit drug contaminated banknotes without any damage of the paper currency. A baseline resolution for heroin and cocaine was achieved within 6 min.

  12. Solid-Phase Extraction and Large-Volume Sample Stacking-Capillary Electrophoresis for Determination of Tetracycline Residues in Milk

    Directory of Open Access Journals (Sweden)

    Gabriela Islas

    2018-01-01

    Full Text Available Solid-phase extraction in combination with large-volume sample stacking-capillary electrophoresis (SPE-LVSS-CE was applied to measure chlortetracycline, doxycycline, oxytetracycline, and tetracycline in milk samples. Under optimal conditions, the proposed method had a linear range of 29 to 200 µg·L−1, with limits of detection ranging from 18.6 to 23.8 µg·L−1 with inter- and intraday repeatabilities < 10% (as a relative standard deviation in all cases. The enrichment factors obtained were from 50.33 to 70.85 for all the TCs compared with a conventional capillary zone electrophoresis (CZE. This method is adequate to analyze tetracyclines below the most restrictive established maximum residue limits. The proposed method was employed in the analysis of 15 milk samples from different brands. Two of the tested samples were positive for the presence of oxytetracycline with concentrations of 95 and 126 µg·L−1. SPE-LVSS-CE is a robust, easy, and efficient strategy for online preconcentration of tetracycline residues in complex matrices.

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

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Antonio, Ernest J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    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 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 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).

  14. Analysis of Three Compounds in Flos Farfarae by Capillary Electrophoresis with Large-Volume Sample Stacking

    Directory of Open Access Journals (Sweden)

    Hai-xia Yu

    2017-01-01

    Full Text Available The aim of this study was to develop a method combining an online concentration and high-efficiency capillary electrophoresis separation to analyze and detect three compounds (rutin, hyperoside, and chlorogenic acid in Flos Farfarae. In order to get good resolution and enrichment, several parameters such as the choice of running buffer, pH and concentration of the running buffer, organic modifier, temperature, and separation voltage were all investigated. The optimized conditions were obtained as follows: the buffer of 40 mM NaH2P04-40 mM Borax-30% v/v methanol (pH 9.0; the sample hydrodynamic injection of up to 4 s at 0.5 psi; 20 kV applied voltage. The diode-array detector was used, and the detection wavelength was 364 nm. Based on peak area, higher levels of selective and sensitive improvements in analysis were observed and about 14-, 26-, and 5-fold enrichment of rutin, hyperoside, and chlorogenic acid were achieved, respectively. This method was successfully applied to determine the three compounds in Flos Farfarae. The linear curve of peak response versus concentration was from 20 to 400 µg/ml, 16.5 to 330 µg/mL, and 25 to 500 µg/mL, respectively. The regression coefficients were 0.9998, 0.9999, and 0.9991, respectively.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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/Health 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.

  16. A generic-tee-plenum mixing system for application to single point aerosol sampling in stacks and ducts.

    Science.gov (United States)

    Han, Taewon; O'Neal, Dennis L; Ortiz, Carlos A

    2007-01-01

    The ANSI/HPS-N13.1-1999 standard is based on the concept of obtaining a single point representative sample from a location where the velocity and contaminant profiles are relatively uniform. It is difficult to predict the level of mixing in an arbitrary stack or duct without experimental data to meet the ANSI/HPS N13.1-1999 requirements. The goal of this study was to develop experimental data for a range of conditions in "S" (S-shaped configuration) duct systems with different mixing elements and "S" systems having one or two mixing elements. Results were presented in terms of the coefficients of variation (COVs) for velocity, tracer gas, and 10-mum aerodynamic diameter (AD) aerosol particle profiles at different downstream locations for each mixing element. Five mixing elements were tested, including a 90 degrees elbow, a commercial static mixer, a Small-Horizontal Generic-Tee-Plenum (SH-GTP), a Small-Vertical Generic-Tee-Plenum (SV-GTP), and a Large-Horizontal Generic-Tee-Plenum (LH-GTP) system. The COVs for velocity, gas concentration, and aerosol particles for the three GTP systems were all determined to be less than 8%. Tests with two different sizes of GTPs were conducted, and the results showed the performance of the GTPs was relatively unaffected by either size or velocity as reflected by the Reynolds number. The pressure coefficients were 0.59, 0.57, and 0.65, respectively, for the SH-GTP, SV-GTP, and LH-GTP. The pressure drop for the GTPs was approximately twice that of the round elbow, but a factor of 5 less than a Type IV Air Blender. The GTP was developed to provide a sampling location less than 4-duct diameters downstream of a mixing element with low pressure drop condition. The object of the developmental effort was to provide a system that could be employed in new stack; however, the concept of GTPs could also be retrofitted onto existing system applications as well. Results from these tests show that the system performance is well within the ANSI

  17. Rapid and sensitive determination of strychnine and brucine in human urine by capillary electrophoresis with field-amplified sample stacking.

    Science.gov (United States)

    Li, Junmei; Jiang, Ye

    2010-02-01

    A simple, rapid, sensitive and low-cost method using capillary electrophoresis (CE) coupled with field-amplified sample stacking (FASS) has been developed and validated for the simultaneous determination of strychnine and brucine residues in human urine. Before sample loading, a water plug (3.5 kPa, 3 s) was injected to contain sample cations and to permit FASS. Electrokinetic injection at a voltage (20 kV, 25 s) was then used to introduce cations. Separation was performed using 20 mM acetate buffer (pH 3.8) with an applied voltage of 20 kV. The calibration curves were linear over a range of 8.00-2.56 infinity 10(2) ng/mL (r = 0.9995) for strychnine and 10.0-3.20 x 10(2) ng/mL (r = 0.9999) for brucine. Extraction recoveries in urine were greater than 79.6 and 82.8% for strychnine and brucine, respectively, with an RSD of less than 4.9%. The detection limits (signal-to-noise ratio 3) for strychnine and brucine were 2.00 and 2.50 ng/mL, respectively. A urine sample from one healthy female volunteer (26 years old, 50 kg) was pretreated and analyzed. Strychnine and brucine levels in urine could be detected 24 h after administration. On these grounds, this method was feasible for application to preliminary screening of trace levels of abused drugs for both doping control and forensic analysis. (c) 2009 John Wiley & Sons, Ltd.

  18. Application of particle size distributions to total particulate stack samples to estimate PM2.5 and PM10 emission factors for agricultural sources

    Science.gov (United States)

    Particle size distributions (PSD) have long been used to more accurately estimate the PM10 fraction of total particulate matter (PM) stack samples taken from agricultural sources. These PSD analyses were typically conducted using a Coulter Counter with 50 micrometer aperture tube. With recent increa...

  19. Electrophoretic large volume sample stacking for sensitive determination of the anti-microbial agent pentamidine in rat plasma for pharmacological studies.

    Science.gov (United States)

    Tůma, Petr; Heneberg, Petr; Vaculín, Šimon; Koval, Dušan

    2018-01-02

    A sensitive capillary electrophoretic method with on-line sample preconcentration by large volume sample stacking has been developed for determination of the anti-microbial agent pentamidine. The separation is performed in a fused silica capillary coated with covalently bound hydroxypropyl cellulose, with an internal diameter of 50 μm and length of 31.5 cm; the background electrolyte was 100 mM acetic acid/Tris at pH 4.7. The stacking is tested using a model sample of 1 μM pentamidine dissolved in 25% infusion solution and 75% acidified acetonitrile. Stacking permits the injection of a sample zone with a length of 95% of the total capillary length to achieve an enhancing factor of 77 compared to low injection into 1.8% of the total capillary length, with simultaneous high separation efficiency of approximately 1 350 000 plates/m. Stacking is based on simultaneous application of a separation field and a hydrodynamic pressure to force the acetonitrile zone out of the capillary. This approach allows the determination of pentamidine in rat blood plasma using only 12.5 μL of plasma treated by the addition of acetonitrile in a ratio of 1:3 v/v. The attained LOD is 0.03 μM and the intra-day repeatability is 0.1% for the migration time and 1.0% for the peak area at the injection 28.3% of capillary length. The performed pharmacokinetic study with ten-second scanning of the blood reveals rapid dynamics of pentamidine in the arterial bloodstream, while the changes are much slower in the venous system. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Effect of NaOH on large-volume sample stacking of haloacetic acids in capillary zone electrophoresis with a low-pH buffer.

    Science.gov (United States)

    Tu, Chuanhong; Zhu, Lingyan; Ang, Chay Hoon; Lee, Hian Kee

    2003-06-01

    Large-volume sample stacking (LVSS) is an effective on-capillary sample concentration method in capillary zone electrophoresis, which can be applied to the sample in a low-conductivity matrix. NaOH solution is commonly used to back-extract acidic compounds from organic solvent in sample pretreatment. The effect of NaOH as sample matrix on LVSS of haloacetic acids was investigated in this study. It was found that the presence of NaOH in sample did not compromise, but rather help the sample stacking performance if a low pH background electrolyte (BGE) was used. The sensitivity enhancement factor was higher than the case when sample was dissolved in pure water or diluted BGE. Compared with conventional injection (0.4% capillary volume), 97-120-fold sensitivity enhancement in terms of peak height was obtained without deterioration of separation with an injection amount equal to 20% of the capillary volume. This method was applied to determine haloacetic acids in tap water by combination with liquid-liquid extraction and back-extraction into NaOH solution. Limits of detection at sub-ppb levels were obtained for real samples with direct UV detection.

  1. Algebraic stacks

    Indian Academy of Sciences (India)

    generally, any fiber product) is not uniquely defined: it is only defined up to unique isomorphism. ..... Fiber product. Given two morphisms f1 : F1 ! G, f2 : F2 ! G, we define a new stack. F1 آG F2 (with projections to F1 and F2) as follows. The objects are triples ًX1; X2; ق ..... In fact, any Artin stack F can be defined in this fashion.

  2. THE SAMPLING PROCESS IN THE FINANCIAL AUDIT .TECHNICAL PRACTICE APPROACH

    Directory of Open Access Journals (Sweden)

    GRIGORE MARIAN

    2014-07-01

    “Audit sampling” (sampling assumes appliancing audit procedures for less than 100% of the elements within an account or a trasaction class balance, such that all the samples will be selected. This will allow the auditor to obtain and to evaluate the audit evidence on some features for the selected elements, in purpose to assist or to express a conclusion regardind the population within the sample was extracted. The sampling in audit can use both a statistical or a non-statistical approach. (THE AUDIT INTERNATIONAl STANDARD 530 –THE SAMPLING IN AUDIT AND OTHER SELECTIVE TESTING PROCEDURES

  3. THE SAMPLING PROCESS IN THE FINANCIAL AUDIT .TECHNICAL PRACTICE APPROACH

    Directory of Open Access Journals (Sweden)

    Cardos Vasile-Daniel

    2014-12-01

    “Audit sampling” (sampling assumes appliancing audit procedures for less than 100% of the elements within an account or a trasaction class balance, such that all the samples will be selected. This will allow the auditor to obtain and to evaluate the audit evidence on some features for the selected elements, in purpose to assist or to express a conclusion regardind the population within the sample was extracted. The sampling in audit can use both a statistical or a non-statistical approach. (THE AUDIT INTERNATIONAl STANDARD 530 –THE SAMPLING IN AUDIT AND OTHER SELECTIVE TESTING PROCEDURES

  4. Sample Stacking Provides Three Orders of Magnitude Sensitivity Enhancement in SDS Capillary Gel Electrophoresis of Adeno-Associated Virus Capsid Proteins.

    Science.gov (United States)

    Zhang, Chao-Xuan; Meagher, Michael M

    2017-03-21

    Size-based protein analysis utilizing only 25 ng of total proteins has been realized by sodium dodecyl sulfate capillary gel electrophoresis (SDS CGE) with head-column field-amplified sample stacking as an online sample preconcentration technique. This method has been used as a replacement of SDS-PAGE for purity analysis of adeno-associated virus (AAV) therapeutic products of different serotypes and transgenes. A limit of detection of 0.2 ng/mL (3.3 pM) capsid proteins was achieved with convenient UV absorbance detection at 214 nm, equivalent to 20 pg of protein (330 attomole) loaded in the autosampler vial. For purity analysis, only 25 ng of total AAV capsid proteins (4.3 femtomole virus particles) were loaded to the autosampler vial. The sensitivity is comparable to silver-stained SDS-PAGE. The RSD of purity measurement was 0.0-0.8%, comparable to conventional SDS CGE utilizing 0.1-0.5 mg proteins. The new method provided 3 orders of magnitude sensitivity enhancement as compared to conventional SDS CGE. It shares all the advantages of conventional SDS CGE (labor-saving, easy automation, and convenient quantitation) and also the high sensitivity of silver stained SDS-PAGE. The sample stacking SDS CGE technique can be adopted for size-based analysis of other types of proteins. It is especially useful when protein quantity or concentration is not sufficient for regular SDS CGE or SDS-PAGE assay.

  5. Stack filter classifiers

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Reid B [Los Alamos National Laboratory; Hush, Don [Los Alamos National Laboratory

    2009-01-01

    Just as linear models generalize the sample mean and weighted average, weighted order statistic models generalize the sample median and weighted median. This analogy can be continued informally to generalized additive modeels in the case of the mean, and Stack Filters in the case of the median. Both of these model classes have been extensively studied for signal and image processing but it is surprising to find that for pattern classification, their treatment has been significantly one sided. Generalized additive models are now a major tool in pattern classification and many different learning algorithms have been developed to fit model parameters to finite data. However Stack Filters remain largely confined to signal and image processing and learning algorithms for classification are yet to be seen. This paper is a step towards Stack Filter Classifiers and it shows that the approach is interesting from both a theoretical and a practical perspective.

  6. Remaining Sites Verification Package for the 100-F-46, 119-F Stack Sampling French Drain. Attachment to Waste Site Reclassification Form 2008-021

    International Nuclear Information System (INIS)

    Capron, J.M.

    2008-01-01

    The 100-F-46 french drain consisted of a 1.5 to 3 m long, vertically buried, gravel-filled pipe that was approximately 1 m in diameter. Also included in this waste site was a 5 cm cast-iron pipeline that drained condensate from the 119-F Stack Sampling Building into the 100-F-46 french drain. In accordance with this evaluation, the confirmatory sampling results support a reclassification of this site to No Action. The current site conditions achieve the remedial action objectives and the corresponding remedial action goals established in the Remaining Sites ROD. The results of confirmatory sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River

  7. Algebraic stacks

    Indian Academy of Sciences (India)

    truct the 'moduli stack', that captures all the information that we would like in a fine moduli space. ..... the fine moduli space), it has the property that for any family W of vector bundles (i.e. W is a vector bundle over B ...... the etale topology is finer: V is a 'small enough open subset' because the square root can be defined on it.

  8. Automated large-volume sample stacking procedure to detect labeled peptides at picomolar concentration using capillary electrophoresis and laser-induced fluorescence detection.

    Science.gov (United States)

    Siri, Nathalie; Riolet, Pierre; Bayle, Christophe; Couderc, François

    2003-08-05

    We have developed an automated large-volume sample stacking (LVSS) procedure to detect fluorescein isothiocyanate-labeled peptides in the picomolar range. The injection duration is 10 min at 50 mbar to fill 62% of the capillary volume to the detection cell. The calculated limit of detection (S/N=3), filling 1% of the capillary volume, is 74 pM for bradykinin and 45 pM for L-enkephalin with samples diluted in water and analyzed in a 50 mM borate buffer, pH 9.2. With the automated LVSS system, the limits of detection are 7 pM for bradykinin, 3 pM for L-enkephalin and 2 pM for substance P. LVSS is shown to be quantitative from 500 to 10 pM.

  9. Fast and sensitive method to determine parabens by capillary electrophoresis using automatic reverse electrode polarity stacking mode: application to hair samples.

    Science.gov (United States)

    Sako, Alysson V F; Dolzan, Maressa D; Micke, Gustavo Amadeu

    2015-09-01

    This paper describes a fast and sensitive method for the determination of methyl, ethyl, propyl, and butylparaben in hair samples by capillary electrophoresis using automatic reverse electrode polarity stacking mode. In the proposed method, solutions are injected using the flush command of the analysis software (940 mbar) and the polarity switching is carried out automatically immediately after the sample injection. The advantages compared with conventional stacking methods are the increased analytical frequency, repeatability, and inter-day precision. All analyses were performed in a fused silica capillary (50 cm, 41.5 cm in effective length, 50 μm i.d.), and the background electrolyte was composed of 20 mmol L(-1) sodium tetraborate in 10 % of methanol, pH 9.3. For the reverse polarity, -25 kV/35 s was applied followed by application of +30 kV for the electrophoretic run. Temperature was set at 20 °C, and all analytes were monitored at 297 nm. The method showed acceptable linearity (r (2) > 0.997) in the studied range of 0.1-5.0 mg L(-1), limits of detection below 0.017 mg L(-1), and inter-day, intra-day, and instrumental precision better than 6.2, 3.6, and 4.6 %, respectively. Considering parabens is widely used as a preservative in many products and the reported possibility of damage to the hair and also to human health caused by these compounds, the proposed method was applied to evaluate the adsorption of parabens in hair samples. The results indicate that there is a greater adsorption of methylparaben compared to the other parabens tested and also dyed hairs had a greater adsorption capacity for parabens than natural hairs.

  10. Combination of large volume sample stacking and reversed pH junction in capillary electrophoresis for online preconcentration of glycoforms of recombinant human erythropoietin.

    Science.gov (United States)

    Liu, Jing; Liu, Zhen; Kang, Mingchao; Liu, Sichang; Chen, Hong-Yuan

    2009-02-01

    Resolution of glycoforms of a glycoprotein is usually a challenge for an analytical chemist, which is often associated with the difficulty of detecting a large number of glycoforms with sufficient sensitivity. CE is the main workhorse for the analysis of glycoproteins; however, the current methods are only applicable to high concentration samples. Therefore, the development of online preconcentration approaches is important for the CE analysis of glycoproteins. In this study, we present a combined strategy for online preconcentrating glycoforms of glycoproteins, which couples two individual online preconcentration techniques, i.e., large volume sample stacking (LVSS) and reversed pH junction (RPHJ). LVSS allows for compressing a large injected sample volume into a narrow sample zone, contributing to the main sensitivity improvement, while RPHJ coordinates the preconcentration process to improve the resolution. This strategy was verified with recombinant human erythropoietin (rhEPO), a typical glycoprotein, as the test analyte, and the effects of experimental conditions were investigated. It was found that there is a compromise between sensitivity enhancement and resolution for online preconcentration of glycoprotein glycoforms. By using this strategy, the detection sensitivity can be improved by 50-100 times for rhEPO.

  11. Project W-420 stack monitoring system upgrades

    International Nuclear Information System (INIS)

    CARPENTER, K.E.

    1999-01-01

    This project will execute the design, procurement, construction, startup, and turnover activities for upgrades to the stack monitoring system on selected Tank Waste Remediation System (TWRS) ventilation systems. In this plan, the technical, schedule, and cost baselines are identified, and the roles and responsibilities of project participants are defined for managing the Stack Monitoring System Upgrades, Project W-420

  12. Ultra-sensitive speciation analysis of mercury by CE-ICP-MS together with field-amplified sample stacking injection and dispersive solid-phase extraction.

    Science.gov (United States)

    Chen, YiQuan; Cheng, Xian; Mo, Fan; Huang, LiMei; Wu, Zujian; Wu, Yongning; Xu, LiangJun; Fu, FengFu

    2016-04-01

    A simple dispersive solid-phase extraction (DSPE) used to extract and preconcentrate ultra-trace MeHg, EtHg and Hg(2+) from water sample, and a sensitive method for the simultaneous analysis of MeHg, EtHg and Hg(2+) by using capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICP-MS) with field-amplified sample stacking injection (FASI) were first reported in this study. The DSPE used thiol cotton particles as adsorbent, and is simple and effective. It can be used to extract and preconcentrate ultra-trace mercury compounds in water samples within 30 min with a satisfied recovery and no mercury species alteration during the process. The FASI enhanced the sensitivity of CE-ICP-MS with 25-fold, 29-fold and 27-fold for MeHg, EtHg and Hg(2+) , respectively. Using FASI-CE-ICP-MS together with DSPE, we have successfully determined ultra-trace MeHg, EtHg and Hg(2+) in tap water with a limits of quantification (LOQs) of 0.26-0.45 pg/mL, an RSD (n = 3) analysis of ultra-trace mercury. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. On-line capillary electrophoresis enrichment by combining chitosan trapping with surfactant assisted sample stacking for the ultratrace determination of organic acids in Plateau alfalfa roots.

    Science.gov (United States)

    Li, Xi; Ju, Yuyun; Xu, Yinyin; Wang, Weifeng; Dong, Yalei; Ma, Yanhua; Chen, Xingguo

    2013-07-30

    In this paper, four organic acids constituents of Plateau alfalfa roots have been identified and detected by a novel capillary electrophoresis (CE) strategy which combined chitosan (CS) trapping and cetyltrimethyl ammonium bromide (CTAB) assisted sample stacking. Under the optimized condition, organic acids, i.e., aconitic acid, gallic acid, citric acid and l-malic acid were concentrated and separated within 3 min. Validation parameters of this method (such as detection limits, linearity and precision) were also investigated and the limit of detection (LOD) was 2.41-53.9 ng mL(-1). Linearity was obtained over the magnitude range of 5-4000 ng mL(-1) approximately for different organic acids and 3×10(2)-1.5×10(4) folds enrichment was achieved. The method has been applied to the determination of organic acids in roots of normal grown Plateau alfalfa and stressing affected Plateau alfalfa. Satisfactory results and recoveries were obtained in the analysis without costly and complicated sample pretreatment. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Insights into head-column field-amplified sample stacking: Part II. Study of the behavior of the electrophoretic system after electrokinetic injection of cationic compounds across a short water plug

    Czech Academy of Sciences Publication Activity Database

    Šesták, Jozef; Thormann, W.

    2017-01-01

    Roč. 1512, AUG (2017), s. 124-132 ISSN 0021-9673 Institutional support: RVO:68081715 Keywords : head- column field-amplified sample stacking * capillary electrophoresis * water plug Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 3.981, year: 2016

  15. Development of a New Microextraction Fiber Combined to On-Line Sample Stacking Capillary Electrophoresis UV Detection for Acidic Drugs Determination in Real Water Samples

    Directory of Open Access Journals (Sweden)

    Maria Espina-Benitez

    2017-07-01

    Full Text Available A new analytical method coupling a (off-line solid-phase microextraction with an on-line capillary electrophoresis (CE sample enrichment technique was developed for the analysis of ketoprofen, naproxen and clofibric acid from water samples, which are known as contaminants of emerging concern in aquatic environments. New solid-phase microextraction fibers based on physical coupling of chromatographic supports onto epoxy glue coated needle were studied for the off-line preconcentration of these micropollutants. Identification and quantification of such acidic drugs were done by capillary zone electrophoresis (CZE using ultraviolet diode array detection (DAD. Further enhancement of concentration sensitivity detection was achieved by on-line CE “acetonitrile stacking” preconcentration technique. Among the eight chromatographic supports investigated, Porapak Q sorbent showed higher extraction and preconcentration capacities. The screening of parameters that influence the microextraction process was carried out using a two-level fractional factorial. Optimization of the most relevant parameters was then done through a surface response three-factor Box-Behnken design. The limits of detection and limits of quantification for the three drugs ranged between 0.96 and 1.27 µg∙L−1 and 2.91 and 3.86 µg∙L−1, respectively. Recovery yields of approximately 95 to 104% were measured. The developed method is simple, precise, accurate, and allows quantification of residues of these micropollutants in Genil River water samples using inexpensive fibers.

  16. Savannah River Site sample and analysis plan for Clemson Technical Center waste

    International Nuclear Information System (INIS)

    Hagstrom, T.

    1998-04-01

    The purpose of this sampling and analysis plan is to determine the chemical, physical and radiological properties of the SRS radioactive Polychlorinated Biphenyl (PCB) liquid waste stream, to verify that it conforms to Waste Acceptance Criteria of the Department of Energy (DOE) East Tennessee Technology Park (ETTP) Toxic Substance Control Act (TSCA) Incineration Facility. Waste being sent to the ETTP TSCA Incinerator for treatment must be sufficiently characterized to ensure that the waste stream meets the waste acceptance criteria to ensure proper handling, classification, and processing of incoming waste to meet the Waste Storage and Treatment Facility's Operating Permits. This sampling and analysis plan is limited to WSRC container(s) of homogeneous or multiphasic radioactive PCB contaminated liquids generated in association with a treatability study at Clemson Technical Center (CTC) and currently stored at the WSRC Solid Waste Division Mixed Waste Storage Facility (MWSF)

  17. Technical Basis for the Removal of Unremediated Nitrate Salt Sampling (UNS) to Support LANL Treatment Studies

    Energy Technology Data Exchange (ETDEWEB)

    Funk, David John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-05

    The sampling of unremediated nitrate salts (UNS) was originally proposed by the U.S. Department of Energy (DOE) and Los Alamos National Security, LLC (LANS) (collectively, the Permittees) as a means to ensure adequate understanding and characterization of the problematic waste stream created when the Permittees remediated these nitrate salts-bearing waste with an organic absorbent. The proposal to sample the UNS was driven by a lack of understanding with respect to the radioactive contamination release that occurred within the underground repository at the Waste Isolation Pilot Plant (WIPP) in February 14, 2014, as well as recommendations made by a Peer Review Team. As discussed, the Permittees believe that current knowledge and understanding of the waste has sufficiently matured such that this additional sampling is not required. Perhaps more importantly, the risk of both chemical and radiological exposure to the workers sampling the UNS drum material is unwarranted. This memo provides the technical justification and rationale for excluding the UNS sampling from the treatment studies.

  18. Technical assessment of TRUSAF for compliance with work place air sampling. Revision 1

    International Nuclear Information System (INIS)

    Butler, J.D.

    1995-01-01

    The purpose of this Technical Work Document is to satisfy WHC-CM-1-6, the ''WHC Radiological Control Manual.'' This first revision of the original Supporting Document covers the period from January 1, 1994 to December 31, 1994. WHC-CM-1-6 is the primary guidance for radiological control at Westinghouse Hanford Company (WHC). As such, it complies with Title 10, Part 835 of the Code of Federal Regulations. In addition to WHC-CM-1-6, there is HSRCM-1, the ''Hanford Site Radiological Control Manual'' and several Department of Energy (DOE) Orders, national consensus standards, and reports that provide criteria, standards, and requirements for workplace air sampling programs. This document provides a summary of these, as they apply to WHC facility workplace air sampling programs. this document also provides an evaluation of the compliance of the TRUSAF workplace air sampling program to the criteria, standards, and requirements and documents. Where necessary, it also indicates changes needed to bring specific locations into compliance

  19. Technical bases and guidance for the use of composite soil sampling for demonstrating compliance with radiological release criteria

    International Nuclear Information System (INIS)

    Vitkus, Timothy J.

    2012-01-01

    This guidance provides information on methodologies and the technical bases that licensees should consider for incorporating composite sampling strategies into final status survey (FSS) plans. In addition, this guidance also includes appropriate uses of composite sampling for generating the data for other decommissioning site investigations such as characterization or other preliminary site investigations

  20. Deploying OpenStack

    CERN Document Server

    Pepple, Ken

    2011-01-01

    OpenStack was created with the audacious goal of being the ubiquitous software choice for building public and private cloud infrastructures. In just over a year, it's become the most talked-about project in open source. This concise book introduces OpenStack's general design and primary software components in detail, and shows you how to start using it to build cloud infrastructures. If you're a developer, technologist, or system administrator familiar with cloud offerings such as Rackspace Cloud or Amazon Web Services, Deploying OpenStack shows you how to obtain and deploy OpenStack softwar

  1. OpenStack cloud computing cookbook

    CERN Document Server

    Jackson, Kevin

    2013-01-01

    A Cookbook full of practical and applicable recipes that will enable you to use the full capabilities of OpenStack like never before.This book is aimed at system administrators and technical architects moving from a virtualized environment to cloud environments with familiarity of cloud computing platforms. Knowledge of virtualization and managing linux environments is expected.

  2. OpenStack essentials

    CERN Document Server

    Radez, Dan

    2015-01-01

    If you need to get started with OpenStack or want to learn more, then this book is your perfect companion. If you're comfortable with the Linux command line, you'll gain confidence in using OpenStack.

  3. Mastering OpenStack

    CERN Document Server

    Khedher, Omar

    2015-01-01

    This book is intended for system administrators, cloud engineers, and system architects who want to deploy a cloud based on OpenStack in a mid- to large-sized IT infrastructure. If you have a fundamental understanding of cloud computing and OpenStack and want to expand your knowledge, then this book is an excellent checkpoint to move forward.

  4. Sample stacking in CZE using dynamic thermal junctions I. Analytes with low dpKa/dT crossing a single thermally induced pH junction in a BGE with high dpH/dT.

    Science.gov (United States)

    Mandaji, Marcos; Rübensam, Gabriel; Hoff, Rodrigo Barcellos; Hillebrand, Sandro; Carrilho, Emanuel; Kist, Tarso Ledur

    2009-05-01

    The possibility to compress analyte bands at the beginning of CE runs has many advantages. Analytes at low concentration can be analyzed with high signal-to-noise ratios by using the so-called sample stacking methods. Moreover, sample injections with very narrow initial band widths (small initial standard deviations) are sometimes useful, especially if high resolutions among the bands are required in the shortest run time. In the present work, a method of sample stacking is proposed and demonstrated. It is based on BGEs with high thermal sensitive pHs (high dpH/dT) and analytes with low dpK(a)/dT. High thermal sensitivity means that the working pK(a) of the BGE has a high dpK(a)/dT in modulus. For instance, Tris and Ethanolamine have dpH/dT=-0.028/ degrees C and -0.029/ degrees C, respectively, whereas carboxylic acids have low dpK(a)/dT values, i.e. in the -0.002/ degrees C to+0.002/ degrees C range. The action of cooling and heating sections along the capillary during the runs affects also the local viscosity, conductivity, and electric field strength. The effect of these variables on electrophoretic velocity and band compression is theoretically calculated using a simple model. Finally, this stacking method was demonstrated for amino acids derivatized with naphthalene-2,3-dicarboxaldehyde and fluorescamine using a temperature difference of 70 degrees C between two neighbor sections and Tris as separation buffer. In this case, the BGE has a high pH thermal coefficient whereas the carboxylic groups of the analytes have low pK(a) thermal coefficients. The application of these dynamic thermal gradients increased peak height by a factor of two (and decreased the standard deviations of peaks by a factor of two) of aspartic acid and glutamic acid derivatized with naphthalene-2,3-dicarboxaldehyde and serine derivatized with fluorescamine. The effect of thermal compression of bands was not observed when runs were accomplished using phosphate buffer at pH 7 (negative

  5. Sample stacking in CZE using dynamic thermal junctions II: analytes with high dpKa/dT crossing a single thermal junction in a BGE with low dpH/dT.

    Science.gov (United States)

    Mandaji, Marcos; Rübensam, Gabriel; Hoff, Rodrigo Barcellos; Hillebrand, Sandro; Carrilho, Emanuel; Kist, Tarso Ledur

    2009-05-01

    In a previous work [M. Mandaji, et al., this issue] a sample stacking method was theoretically modeled and experimentally demonstrated for analytes with low dpK(a)/dT (analytes carrying carboxylic groups) and BGEs with high dpH/dT (high pH-temperature-coefficients). In that work, buffer pH was modulated with temperature, inducing electrophoretic mobility changes in the analytes. In the present work, the opposite conditions are studied and tested, i.e. analytes with high dpK(a)/dT and BGEs that exhibit low dpH/dT. It is well known that organic bases such as amines, imidazoles, and benzimidazoles exhibit high dpK(a)/dT. Temperature variations induce instantaneous changes on the basicity of these and other basic groups. Therefore, the electrophoretic velocity of some analytes changes abruptly when temperature variations are applied along the capillary. This is true only if BGE pH remains constant or if it changes in the opposite direction of pK(a) of the analyte. The presence of hot and cold sections along the capillary also affects local viscosity, conductivity, and electric field strength. The effect of these variables on electrophoretic velocity and band stacking efficacy was also taken into account in the theoretical model presented. Finally, this stacking method is demonstrated for lysine partially derivatized with naphthalene-2,3-dicarboxaldehyde. In this case, the amino group of the lateral chain was left underivatized and only the alpha amino group was derivatized. Therefore, the basicity of the lateral amino group, and consequently the electrophoretic mobility, was modulated with temperature while the pH of the buffer used remained unchanged.

  6. Stacking for Cosmic Magnetism with SKA Surveys

    OpenAIRE

    Stil, J. M.; Keller, B. W.

    2015-01-01

    Stacking polarized radio emission in SKA surveys provides statistical information on large samples that is not accessible otherwise due to limitations in sensitivity, source statistics in small fields, and averaging over frequency (including Faraday synthesis). Polarization is a special case because one obvious source of stacking targets is the Stokes I source catalog, possibly in combination with external catalogs, for example an SKA HI survey or a non-radio survey. We point out the signific...

  7. Progress of MCFC stack technology at Toshiba

    Energy Technology Data Exchange (ETDEWEB)

    Hori, M.; Hayashi, T.; Shimizu, Y. [Toshiba Corp., Tokyo (Japan)

    1996-12-31

    Toshiba is working on the development of MCFC stack technology; improvement of cell characteristics, and establishment of separator technology. For the cell technology, Toshiba has concentrated on both the restraints of NiO cathode dissolution and electrolyte loss from cells, which are the critical issues to extend cell life in MCFC, and great progress has been made. On the other hand, recognizing that the separator is one of key elements in accomplishing reliable and cost-competitive MCFC stacks, Toshiba has been accelerating the technology establishment and verification of an advanced type separator. A sub-scale stack with such a separator was provided for an electric generating test, and has been operated for more than 10,000 hours. This paper presents several topics obtained through the technical activities in the MCFC field at Toshiba.

  8. Temperature control of the graphite stack of the reactor RBMK-1500

    International Nuclear Information System (INIS)

    Lesnoj, S.

    1998-01-01

    The paper includes general information about RBMK-1500 reactor, construction features and main technical data; graphite moderator stack, temperature channel, thermocouple TXA-1379, its basic technical and metrologic parameters as well as its advantages and disadvantages

  9. On Stack Reconstruction Problem

    Directory of Open Access Journals (Sweden)

    V. D. Аkeliev

    2009-01-01

    Full Text Available The paper describes analytical investigations that study relation of fuel combustion regimes with concentration values of sulphur anhydride in flue gases and acid dew point. Coefficients of convective heat transfer at internal and external surfaces of stacks have been determined in the paper. The paper reveals the possibility to reconstruct stacks while using gas discharging channel made of composite material on the basis of glass-reinforced plastic which permits to reduce thermo-stressed actions on reinforced concrete and increase volume of released gases due to practically two-fold reduction of gas-dynamic pressure losses along the pipe length.

  10. Laser pulse stacking method

    Science.gov (United States)

    Moses, E.I.

    1992-12-01

    A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter. 2 figs.

  11. Stacking by electroinjection with discontinuous buffers in capillary zone electrophoresis.

    Science.gov (United States)

    Shihabi, Zak K

    2002-08-01

    The work presented here demonstrates that electroinjection can be performed using discontinuous buffers, which can result in better stacking than that obtained by hydrodynamic injection. The sample can be concentrated at the tip of the capillary leaving practically the whole capillary for sample separation. This results in several advantages, such as better sample concentration, higher plate number and shorter time of stacking. However, sample introduction by electromigration is suited for samples free or low in salt content. Samples, which are high in salt content, are better introduced by the hydrodynamic injection for stacking by the discontinuous buffers. Different simple methods to introduce the discontinuity in the buffer for electroinjection are discussed.

  12. po_stack_movie

    DEFF Research Database (Denmark)

    2009-01-01

    po_stack® er et reolsystem, hvis enkle elementer giver stor flexibilitet, variation og skulpturel virkning. Elementerne stables og forskydes frit, så reolens rum kan vendes til begge sider, være åbne eller lukkede og farvekombineres ubegrænset. Reolen kan let ombygges, udvides eller opdeles, når ...

  13. Learning SaltStack

    CERN Document Server

    Myers, Colton

    2015-01-01

    If you are a system administrator who manages multiple servers, then you know how difficult it is to keep your infrastructure in line. If you've been searching for an easier way, this book is for you. No prior experience with SaltStack is required.

  14. Insights into head-column field-amplified sample stacking: Part II. Study of the behavior of the electrophoretic system after electrokinetic injection of cationic compounds across a short water plug.

    Science.gov (United States)

    Šesták, Jozef; Thormann, Wolfgang

    2017-08-25

    Part I on head-column field-amplified sample stacking comprised a detailed study of the electrokinetic injection of a weak base across a short water plug into a phosphate buffer at low pH. The water plug is converted into a low conductive acidic zone and cationic analytes become stacked at the interface between this and a newly formed phosphoric acid zone. The fundamentals of electrokinetic processes occurring thereafter were studied experimentally and with computer simulation and are presented as part II. The configuration analyzed represents a discontinuous buffer system. Computer simulation revealed that the phosphoric acid zone at the plug-buffer interface becomes converted into a migrating phosphate buffer plug which corresponds to the cationically migrating system zone of the phosphate buffer system. Its mobility is higher than that of the analytes such that they migrate behind the system zone in a phosphate buffer comparable to the applied background electrolyte. The temporal behaviour of the current and the conductivity across the water plug were monitored and found to reflect the changes in the low conductivity plug. Determination of the buffer flow in the capillary revealed increased pumping caused by the mismatch of electroosmosis within the low conductivity plug and the buffer. This effect becomes elevated with increasing water plug length. For plug lengths up to 1% of the total column length the flow quickly drops to the electroosmotic flow of the buffer and simulations with experimentally determined current and flow values predict negligible band dispersion and no loss of resolution for both low and large molecular mass components. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Atmospheric aerosol studies using the 'Gent' stacked filter unit and other aerosol collectors, with multi-elemental analysis of the samples by nuclear-related analytical techniques. Appendix 4

    International Nuclear Information System (INIS)

    Maenhaut, Willy; Francois, Filip; Cafmeyer, Jan; Okunade, Olusola

    1995-01-01

    Our research within the core programme of the Co-ordinated Research Programme (CRP) on Air Pollution is described. This included the analysis of the analytical quality control Nuclepore filter samples, work on the calibration of the PM10 inlet of the 'Gent' stacked filter unit (SFU) sampler, and an aerosol study with this SFU sampler at an urban residential site in Gent. The calibration of the Gent PM10 inlet was done through intercomparisons with commercially available PM10 samplers, and quite reasonable agreement was obtained. For the study at the urban residential site, a total of 118 SFU samples were collected. The samples were analyzed for the particulate mass, black carbon and up to 29 elements. The elements were measured by PIXE and short-irradiation INAA. Median atmospheric concentrations and enrichment factors were calculated for the fine and coarse size fractions, and average FINE/COARSE ratios were derived. The median concentrations were compared with those from a study, done at the same site in the fall of 1986. The levels of the automotive elements Pb and Br had decreased by a factor of about three relative to 1986, but most other elements exhibited very similar concentrations. A brief overview is given of the status in our various regional and global scale aerosol studies. Finally, our plans for future work are given. (author)

  16. Cytological preparations for molecular analysis: A review of technical procedures, advantages and limitations for referring samples for testing.

    Science.gov (United States)

    da Cunha Santos, G; Saieg, M A; Troncone, G; Zeppa, P

    2018-04-01

    Minimally invasive procedures such as endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) must yield not only good quality and quantity of material for morphological assessment, but also an adequate sample for analysis of molecular markers to guide patients to appropriate targeted therapies. In this context, cytopathologists worldwide should be familiar with minimum requirements for refereeing cytological samples for testing. The present manuscript is a review with comprehensive description of the content of the workshop entitled Cytological preparations for molecular analysis: pre-analytical issues for EBUS TBNA, presented at the 40th European Congress of Cytopathology in Liverpool, UK. The present review emphasises the advantages and limitations of different types of cytology substrates used for molecular analysis such as archival smears, liquid-based preparations, archival cytospin preparations and FTA (Flinders Technology Associates) cards, as well as their technical requirements/features. These various types of cytological specimens can be successfully used for an extensive array of molecular studies, but the quality and quantity of extracted nucleic acids rely directly on adequate pre-analytical assessment of those samples. In this setting, cytopathologists must not only be familiar with the different types of specimens and associated technical procedures, but also correctly handle the material provided by minimally invasive procedures, ensuring that there is sufficient amount of material for a precise diagnosis and correct management of the patient through personalised care. © 2018 John Wiley & Sons Ltd.

  17. Technical developments for accurate determination of amount of samples used for TOF measurements

    Directory of Open Access Journals (Sweden)

    Terada Kazushi

    2017-01-01

    Full Text Available Activity determination of 241,243Am samples has been performed with two separate methods of calorimetry and gamma-ray spectroscopy. Decay heat measurements of the samples were carried out by using a calorimeter, and activities of the samples were accurately determined with uncertainties less than 0.45%. The primary source of uncertainty in the calorimetric method is the accuracy of available half-life data. Gamma-ray detection efficiencies of a HPGe detector were determined with uncertainties of 1.5% by combining measured efficiencies and Monte Carlo simulation. Activities of the samples were determined with uncertainties less than 2.0% by gamma-ray spectroscopy and were concordant with those of the calorimetry.

  18. Technical Note: New methodology for measuring viscosities in small volumes characteristic of environmental chamber particle samples

    Directory of Open Access Journals (Sweden)

    L. Renbaum-Wolff

    2013-01-01

    Full Text Available Herein, a method for the determination of viscosities of small sample volumes is introduced, with important implications for the viscosity determination of particle samples from environmental chambers (used to simulate atmospheric conditions. The amount of sample needed is < 1 μl, and the technique is capable of determining viscosities (η ranging between 10−3 and 103 Pascal seconds (Pa s in samples that cover a range of chemical properties and with real-time relative humidity and temperature control; hence, the technique should be well-suited for determining the viscosities, under atmospherically relevant conditions, of particles collected from environmental chambers. In this technique, supermicron particles are first deposited on an inert hydrophobic substrate. Then, insoluble beads (~1 μm in diameter are embedded in the particles. Next, a flow of gas is introduced over the particles, which generates a shear stress on the particle surfaces. The sample responds to this shear stress by generating internal circulations, which are quantified with an optical microscope by monitoring the movement of the beads. The rate of internal circulation is shown to be a function of particle viscosity but independent of the particle material for a wide range of organic and organic-water samples. A calibration curve is constructed from the experimental data that relates the rate of internal circulation to particle viscosity, and this calibration curve is successfully used to predict viscosities in multicomponent organic mixtures.

  19. Energy Expenditure of Sport Stacking

    Science.gov (United States)

    Murray, Steven R.; Udermann, Brian E.; Reineke, David M.; Battista, Rebecca A.

    2009-01-01

    Sport stacking is an activity taught in many physical education programs. The activity, although very popular, has been studied minimally, and the energy expenditure for sport stacking is unknown. Therefore, the purposes of this study were to determine the energy expenditure of sport stacking in elementary school children and to compare that value…

  20. OpenStack cloud security

    CERN Document Server

    Locati, Fabio Alessandro

    2015-01-01

    If you are an OpenStack administrator or developer, or wish to build solutions to protect your OpenStack environment, then this book is for you. Experience of Linux administration and familiarity with different OpenStack components is assumed.

  1. SRS reactor stack plume marking tests

    International Nuclear Information System (INIS)

    Petry, S.F.

    1992-03-01

    Tests performed in 105-K in 1987 and 1988 demonstrated that the stack plume can successfully be made visible (i.e., marked) by introducing smoke into the stack breech. The ultimate objective of these tests is to provide a means during an emergency evacuation so that an evacuee can readily identify the stack plume and evacuate in the opposite direction, thus minimizing the potential of severe radiation exposure. The EPA has also requested DOE to arrange for more tests to settle a technical question involving the correct calculation of stack downwash. New test canisters were received in 1988 designed to produce more smoke per unit time; however, these canisters have not been evaluated, because normal ventilation conditions have not been reestablished in K Area. Meanwhile, both the authorization and procedure to conduct the tests have expired. The tests can be performed during normal reactor operation. It is recommended that appropriate authorization and procedure approval be obtained to resume testing after K Area restart

  2. CRADA final report: Technical assessment of roll-to-roll operation of lamination process, thermal treatment, and alternative carbon fiber precursors for low-cost, high-efficiency manufacturing of flow battery stacks and other energy devices

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, Claus [ORNL; Madden, Thomas [Lockheed Martin Corporation; Wood III, David L [ORNL; Muth, Thomas R [ORNL; Warrington, Curtis [Lockheed Martin Corporation; Ozcan, Soydan [ORNL; Manson, Hunter [Oak Ridge National Laboratory (ORNL); Tekinalp, Halil L [ORNL; Smith, Mark A [ORNL; Lu, Yuan [ORNL; Loretz, Jeremy [Oak Ridge National Laboratory (ORNL)

    2015-09-23

    Among the various stationary-storage technologies under development, redox flow batteries (RFBs) offer the greatest potential to deliver inexpensive, scalable, and efficient grid-scale electrical-energy storage. Unlike traditional sealed batteries, in a flow battery power and energy are decoupled. Cell area and cell count in the stack determine the device power, and the chemical storage volume determines the total energy. Grid-scale energy-storage applications require megawatt-scale devices, which require the assembly of hundreds of large-area, bipolar cells per power plant. The cell-stack is the single system component with the largest impact on capital cost (due to the large number of highly engineered components) and operating costs (determined by overall round-trip efficiency).

  3. Minimizing technical variation during sample preparation prior to label-free quantitative mass spectrometry.

    Science.gov (United States)

    Scheerlinck, E; Dhaenens, M; Van Soom, A; Peelman, L; De Sutter, P; Van Steendam, K; Deforce, D

    2015-12-01

    Sample preparation is the crucial starting point to obtain high-quality mass spectrometry data and can be divided into two main steps in a bottom-up proteomics approach: cell/tissue lysis with or without detergents and a(n) (in-solution) digest comprising denaturation, reduction, alkylation, and digesting of the proteins. Here, some important considerations, among others, are that the reagents used for sample preparation can inhibit the digestion enzyme (e.g., 0.1% sodium dodecyl sulfate [SDS] and 0.5 M guanidine HCl), give rise to ion suppression (e.g., polyethylene glycol [PEG]), be incompatible with liquid chromatography-tandem mass spectrometry (LC-MS/MS) (e.g., SDS), and can induce additional modifications (e.g., urea). Taken together, all of these irreproducible effects are gradually becoming a problem when label-free quantitation of the samples is envisioned such as during the increasingly popular high-definition mass spectrometry (HDMS(E)) and sequential window acquisition of all theoretical fragment ion spectra (SWATH) data-independent acquisition strategies. Here, we describe the detailed validation of a reproducible method with sufficient protein yield for sample preparation without any known LC-MS/MS interfering substances by using 1% sodium deoxycholate (SDC) during both cell lysis and in-solution digest. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Technical studies on a composite groundwater sample from F- and H-Area

    International Nuclear Information System (INIS)

    Bibler, J.P.

    1990-01-01

    A composite sample of groundwater from F- and H-Areas was collected by Waste Management Tech and delivered to the Savannah River Laboratory to use in preliminary experiments that would test three remediation technologies under consideration. The three technologies are pH adjustment and filtration, decontamination with a strong acid ion exchange resin, and decontamination with a chelating ion exchange resin

  5. Phase microscopy of technical and biological samples through random phase modulation with a difuser

    DEFF Research Database (Denmark)

    Almoro, Percival; Pedrini, Giancarlo; Gundu, Phanindra Narayan

    2010-01-01

    A technique for phase microscopy using a phase diffuser and a reconstruction algorithm is proposed. A magnified specimen wavefront is projected on the diffuser plane that modulates the wavefront into a speckle field. The speckle patterns at axially displaced planes are sampled and used......) 2010 Optical Society of America...

  6. Levitation characteristics of HTS tape stacks

    Energy Technology Data Exchange (ETDEWEB)

    Pokrovskiy, S. V.; Ermolaev, Y. S.; Rudnev, I. A. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)

    2015-03-15

    Due to the considerable development of the technology of second generation high-temperature superconductors and a significant improvement in their mechanical and transport properties in the last few years it is possible to use HTS tapes in the magnetic levitation systems. The advantages of tapes on a metal substrate as compared with bulk YBCO material primarily in the strength, and the possibility of optimizing the convenience of manufacturing elements of levitation systems. In the present report presents the results of the magnetic levitation force measurements between the stack of HTS tapes containing of tapes and NdFeB permanent magnet in the FC and ZFC regimes. It was found a non- linear dependence of the levitation force from the height of the array of stack in both modes: linear growth at small thickness gives way to flattening and constant at large number of tapes in the stack. Established that the levitation force of stacks comparable to that of bulk samples. The numerical calculations using finite element method showed that without the screening of the applied field the levitation force of the bulk superconductor and the layered superconductor stack with a critical current of tapes increased by the filling factor is exactly the same, and taking into account the screening force slightly different.

  7. Stack Caching Using Split Data Caches

    DEFF Research Database (Denmark)

    Nielsen, Carsten; Schoeberl, Martin

    2015-01-01

    In most embedded and general purpose architectures, stack data and non-stack data is cached together, meaning that writing to or loading from the stack may expel non-stack data from the data cache. Manipulation of the stack has a different memory access pattern than that of non-stack data, showing...... higher temporal and spatial locality. We propose caching stack and non-stack data separately and develop four different stack caches that allow this separation without requiring compiler support. These are the simple, window, and prefilling with and without tag stack caches. The performance of the stack...

  8. UMTRA water sampling technical (peer) review: Responses to observations, comments, and recommendations submitted by Don Messinger (Roy F. Weston, Inc.)

    International Nuclear Information System (INIS)

    1993-08-01

    An independent technical review (peer review) was conducted during the period of September 15--17, 1992. The review was conducted by C. Warren Ankerberg (Geraghty and Miller, Inc., Tampa, Florida) and Don Messinger (Roy F. Weston, Inc., West Chester, Pennsylvania). The review was held at Jacobs Engineering in Albuquerque, New Mexico, and at the Shiprock, New Mexico, site. The peer review included a review of written documentation [water sampling standard operating procedures (SOP)], an inspection of technical reports and other deliverables, a review of staff qualifications and training, and a field visit to evaluate the compliance of field procedures with SOPS. Upon completion of the peer review, each reviewer independently prepared a report of findings from the review. The reports listed findings and recommended actions. This document responds to the observations, comments, and recommendations submitted by Don Messinger following his review. The format of this document is to present the findings and recommendations verbatim from Mr. Messinger's report, followed by responses from the UMTRA Project staff. Included in the responses from the UMTRA Project staff are recommended changes in SOPs and strategies for implementing the charges

  9. Method for monitoring stack gases for uranium activity

    International Nuclear Information System (INIS)

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

    1988-01-01

    A method for sampling stack gases emanating from the purge cascade of a gaseous diffusion cascade system utilized to enrich uranium for determining the presence and extent of uranium in the stack gases in the form of gaseous uranium hexafluoride, is described comprising the steps of removing a side stream of gases from the stack gases, contacting the side stream of the stack gases with a stream of air sufficiently saturated with moisture for reacting with and converting any gaseous uranium hexafluroide contracted thereby in the side stream of stack gases to particulate uranyl fluoride. Thereafter contacting the side stream of stack gases containing the particulate uranyl fluoride with moving filter means for continuously intercepting and conveying the intercepted particulate uranyl fluoride away from the side stream of stack gases, and continually scanning the moving filter means with radiation monitoring means for sensing the presence and extent of particulate uranyl fluoride on the moving filter means which is indicative of the extent of particulate uranyl fluoride in the side stream of stack gases which in turn is indicative of the presence and extent of uranium hexafluoride in the stack gases

  10. Passive stack ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, J.; Parkins, L.; Shaw, P.; Watkins, R. [Databuild, Birmingham (United Kingdom)

    1994-12-31

    The adequate ventilation of houses is essential for both the occupants and the building fabric. As air-tightness standards increase, background infiltration levels decrease and extra ventilation has to be designed into the building. Passive stack ventilation has many advantages - particularly when employed in low cost housing schemes -but it is essential that it performs satisfactorily. This paper give the results from monitoring two passive stack ventilation schemes. One scheme was a retrofit into refurbished local authority houses in which a package of energy efficiency measures had been taken and condensation had been a problem. The other series of tests were conducted on a new installation in a Housing Association development. Nine houses were monitored each of which had at least two passive vents. The results show air flow rates by the passive ducts equivalent to approximately 1 room air change per hour. The air flow in the ducts was influenced by both, internal to external temperature difference and wind speed and direction. (author)

  11. Asymmetric Flexible Supercapacitor Stack

    Directory of Open Access Journals (Sweden)

    Leela Mohana Reddy A

    2008-01-01

    Full Text Available AbstractElectrical double layer supercapacitor is very significant in the field of electrical energy storage which can be the solution for the current revolution in the electronic devices like mobile phones, camera flashes which needs flexible and miniaturized energy storage device with all non-aqueous components. The multiwalled carbon nanotubes (MWNTs have been synthesized by catalytic chemical vapor deposition technique over hydrogen decrepitated Mischmetal (Mm based AB3alloy hydride. The polymer dispersed MWNTs have been obtained by insitu polymerization and the metal oxide/MWNTs were synthesized by sol-gel method. Morphological characterizations of polymer dispersed MWNTs have been carried out using scanning electron microscopy (SEM, transmission electron microscopy (TEM and HRTEM. An assymetric double supercapacitor stack has been fabricated using polymer/MWNTs and metal oxide/MWNTs coated over flexible carbon fabric as electrodes and nafion®membrane as a solid electrolyte. Electrochemical performance of the supercapacitor stack has been investigated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy.

  12. Exhaust stack monitoring issues at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Rodgers, J.C.

    1987-11-01

    This report outlines the problems of obtaining valid, representative samples of, and continuously monitoring for, radioactive particulates in the discharge air from the underground disposal facilities at WIPP. There appears to be serious problems with the presently installed systems. Chapter 1 of the report provides an overview of current perspective on the major issues. Principal conclusions of the overview are that the present sampling locations are not optimum for the intended purpose; that the chosen probe design is not capable of meeting requirements for delivery of a representative sample to the detectors; and that the proposed test plan for the flow conditioning and monitoring system is seriously flawed. Chapter 2 is a summary of the major findings and recommendations of a peer review. The review suggested that the proposed flow conditioning concepts were likely to be an unworkable substitute for having adequate duct length between major disturbances in flow and the sampling or monitoring locations; that the use of probes of simpler design with large diameter inlet nozzles feeding short transmission lines would provide superior performance; and that conditions for monitoring discharge air would be far better ahead of the collar in the exhaust shaft than any location downstream. Chapter 3 contains the detailed technical basis for a conceptual design, and a proposed sample extraction system for the stack discharge location. 36 refs., 23 figs., 4 tabs

  13. Instant BlueStacks

    CERN Document Server

    Judge, Gary

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A fast-paced, example-based approach guide for learning BlueStacks.This book is for anyone with a Mac or PC who wants to run Android apps on their computer. Whether you want to play games that are freely available for Android but not your computer, or you want to try apps before you install them on a physical device or use it as a development tool, this book will show you how. No previous experience is needed as this is written in plain English

  14. Assessing Elementary Algebra with STACK

    Science.gov (United States)

    Sangwin, Christopher J.

    2007-01-01

    This paper concerns computer aided assessment (CAA) of mathematics in which a computer algebra system (CAS) is used to help assess students' responses to elementary algebra questions. Using a methodology of documentary analysis, we examine what is taught in elementary algebra. The STACK CAA system, http://www.stack.bham.ac.uk/, which uses the CAS…

  15. HPC Software Stack Testing Framework

    Energy Technology Data Exchange (ETDEWEB)

    2017-07-27

    The HPC Software stack testing framework (hpcswtest) is used in the INL Scientific Computing Department to test the basic sanity and integrity of the HPC Software stack (Compilers, MPI, Numerical libraries and Applications) and to quickly discover hard failures, and as a by-product it will indirectly check the HPC infrastructure (network, PBS and licensing servers).

  16. CAM and stack air sampler design guide

    International Nuclear Information System (INIS)

    Phillips, T.D.

    1994-01-01

    About 128 air samplers and CAMs presently in service to detect and document potential radioactive release from 'H' and 'F' area tank farm ventilation stacks are scheduled for replacement and/or upgrade by Projects S-5764, S-2081, S-3603, and S-4516. The seven CAMs scheduled to be upgraded by Project S-4516 during 1995 are expected to provide valuable experience for the three remaining projects. The attached document provides design guidance for the standardized High Level Waste air sampling system

  17. Standoff Stack Emissions Monitoring Using Short Range Lidar

    Science.gov (United States)

    Gravel, Jean-Francois Y.; Babin, Francois; Allard, Martin

    2016-06-01

    There are well documented methods for stack emissions monitoring. These are all based on stack sampling through sampling ports in well defined conditions. Once sampled, the molecules are quantified in instruments that often use optical techniques. Unfortunately sampling ports are not found on all stacks/ducts or the use of the sampling ports cannot be planned efficiently because of operational constraints or the emissions monitoring equipment cannot be driven to a remote stack/duct. Emissions monitoring using many of the same optical techniques, but at a standoff distance, through the atmosphere, using short range high spatial resolution lidar techniques was thus attempted. Standoff absorption and Raman will be discussed and results from a field campaign will be presented along with short descriptions of the apparatus. In the first phase of these tests, the molecules that were targeted were NO and O2. Spatially resolved optical measurements allow for standoff identification and quantification of molecules, much like the standardized methods, except for the fact that it is not done in the stack, but in the plume formed by the emissions from the stack. The pros and cons will also be discussed, and in particular the problem of mass emission estimates that require the knowledge of the flow rate and the distribution of molecular concentration in the plane of measurement.

  18. Standoff Stack Emissions Monitoring Using Short Range Lidar

    Directory of Open Access Journals (Sweden)

    Gravel Jean-Francois Y.

    2016-01-01

    Full Text Available There are well documented methods for stack emissions monitoring. These are all based on stack sampling through sampling ports in well defined conditions. Once sampled, the molecules are quantified in instruments that often use optical techniques. Unfortunately sampling ports are not found on all stacks/ducts or the use of the sampling ports cannot be planned efficiently because of operational constraints or the emissions monitoring equipment cannot be driven to a remote stack/duct. Emissions monitoring using many of the same optical techniques, but at a standoff distance, through the atmosphere, using short range high spatial resolution lidar techniques was thus attempted. Standoff absorption and Raman will be discussed and results from a field campaign will be presented along with short descriptions of the apparatus. In the first phase of these tests, the molecules that were targeted were NO and O2. Spatially resolved optical measurements allow for standoff identification and quantification of molecules, much like the standardized methods, except for the fact that it is not done in the stack, but in the plume formed by the emissions from the stack. The pros and cons will also be discussed, and in particular the problem of mass emission estimates that require the knowledge of the flow rate and the distribution of molecular concentration in the plane of measurement.

  19. Environmental assessment of phosphogypsum stacks

    International Nuclear Information System (INIS)

    Odat, M.; Al-Attar, L.; Raja, G.; Abdul Ghany, B.

    2008-03-01

    Phosphogypsum is one of the most important by-products of phosphate fertilizer industry. It is kept in large stacks to the west of Homs city. Storing Phosphogypsum as open stacks exposed to various environmental effects, wind and rain, may cause pollution of the surrounding ecosystem (soil, plant, water and air). This study was carried out in order to assess the environmental impact of Phosphogypsum stacks on the surrounding ecosystem. The obtained results show that Phosphogypsum stacks did not increase the concentration of radionuclides, i.e. Radon-222 and Radium-226, the external exposed dose of gamma rays, as well as the concentration of heavy metals in the components of the ecosystem, soil, plant, water and air, as their concentrations did not exceed the permissible limits. However, the concentration of fluorine in the upper layer of soil, located to the east of the Phosphogypsum stacks, increased sufficiently, especially in the dry period of the year. Also, the concentration of fluoride in plants growing up near-by the Phosphogypsum stacks was too high, exceeded the permissible levels. This was reflected in poising plants and animals, feeding on the plants. Consequently, increasing the concentration of fluoride in soil and plants is the main impact of Phosphogypsum stacks on the surrounding ecosystem. Minimising this effect could be achieved by establishing a 50 meter wide protection zone surrounding the Phosphogypsum stacks, which has to be planted with non palatable trees, such as pine and cypress, forming wind barriers. Increasing the concentrations of heavy metals and fluoride in infiltrated water around the stacks was high; hence cautions must be taken to prevent its usage in any application or disposal in adjacent rivers and leaks.(author)

  20. PieceStack: Toward Better Understanding of Stacked Graphs.

    Science.gov (United States)

    Wu, Tongshuang; Wu, Yingcai; Shi, Conglei; Qu, Huamin; Cui, Weiwei

    2016-02-24

    Stacked graphs have been widely adopted in various fields, because they are capable of hierarchically visualizing a set of temporal sequences as well as their aggregation. However, because of visual illusion issues, connections between overly-detailed individual layers and overly-generalized aggregation are intercepted. Consequently, information in this area has yet to be fully excavated. Thus, we present PieceStack in this paper, to reveal the relevance of stacked graphs in understanding intrinsic details of their displayed shapes. This new visual analytic design interprets the ways through which aggregations are generated with individual layers by interactively splitting and re-constructing the stacked graphs. A clustering algorithm is designed to partition stacked graphs into sub-aggregated pieces based on trend similarities of layers. We then visualize the pieces with augmented encoding to help analysts decompose and explore the graphs with respect to their interests. Case studies and a user study are conducted to demonstrate the usefulness of our technique in understanding the formation of stacked graphs.

  1. Prevalence of technical errors and periapical lesions in a sample of endodontically treated teeth: a CBCT analysis.

    Science.gov (United States)

    Nascimento, Eduarda Helena Leandro; Gaêta-Araujo, Hugo; Andrade, Maria Fernanda Silva; Freitas, Deborah Queiroz

    2018-01-21

    The aims of this study are to identify the most frequent technical errors in endodontically treated teeth and to determine which root canals were most often associated with those errors, as well as to relate endodontic technical errors and the presence of coronal restorations with periapical status by means of cone-beam computed tomography images. Six hundred eighteen endodontically treated teeth (1146 root canals) were evaluated for the quality of their endodontic treatment and for the presence of coronal restorations and periapical lesions. Each root canal was classified according to dental groups, and the endodontic technical errors were recorded. Chi-square's test and descriptive analyses were performed. Six hundred eighty root canals (59.3%) had periapical lesions. Maxillary molars and anterior teeth showed higher prevalence of periapical lesions (p technical error in all root canals, except for the second mesiobuccal root canal of maxillary molars and the distobuccal root canal of mandibular molars, which were non-filled in 78.4 and 30% of the cases, respectively. There is a high prevalence of apical radiolucencies, which increased in the presence of poor coronal restorations, endodontic technical errors, and when both conditions were concomitant. Underfilling was the most frequent technical error, followed by non-homogeneous and non-filled canals. Evaluation of endodontic treatment quality that considers every single root canal aims on warning dental practitioners of the prevalence of technical errors that could be avoided with careful treatment planning and execution.

  2. Electrochemical Detection in Stacked Paper Networks.

    Science.gov (United States)

    Liu, Xiyuan; Lillehoj, Peter B

    2015-08-01

    Paper-based electrochemical biosensors are a promising technology that enables rapid, quantitative measurements on an inexpensive platform. However, the control of liquids in paper networks is generally limited to a single sample delivery step. Here, we propose a simple method to automate the loading and delivery of liquid samples to sensing electrodes on paper networks by stacking multiple layers of paper. Using these stacked paper devices (SPDs), we demonstrate a unique strategy to fully immerse planar electrodes by aqueous liquids via capillary flow. Amperometric measurements of xanthine oxidase revealed that electrochemical sensors on four-layer SPDs generated detection signals up to 75% higher compared with those on single-layer paper devices. Furthermore, measurements could be performed with minimal user involvement and completed within 30 min. Due to its simplicity, enhanced automation, and capability for quantitative measurements, stacked paper electrochemical biosensors can be useful tools for point-of-care testing in resource-limited settings. © 2015 Society for Laboratory Automation and Screening.

  3. Learning algorithms for stack filter classifiers

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Reid B [Los Alamos National Laboratory; Hush, Don [Los Alamos National Laboratory; Zimmer, Beate G [TEXAS A& M

    2009-01-01

    Stack Filters define a large class of increasing filter that is used widely in image and signal processing. The motivations for using an increasing filter instead of an unconstrained filter have been described as: (1) fast and efficient implementation, (2) the relationship to mathematical morphology and (3) more precise estimation with finite sample data. This last motivation is related to methods developed in machine learning and the relationship was explored in an earlier paper. In this paper we investigate this relationship by applying Stack Filters directly to classification problems. This provides a new perspective on how monotonicity constraints can help control estimation and approximation errors, and also suggests several new learning algorithms for Boolean function classifiers when they are applied to real-valued inputs.

  4. Technical aspects of endoscopic ultrasound (EUS)-guided sampling in gastroenterology: European Society of Gastrointestinal Endoscopy (ESGE) Technical Guideline - March 2017.

    Science.gov (United States)

    Polkowski, Marcin; Jenssen, Christian; Kaye, Philip; Carrara, Silvia; Deprez, Pierre; Gines, Angels; Fernández-Esparrach, Gloria; Eisendrath, Pierre; Aithal, Guruprasad P; Arcidiacono, Paolo; Barthet, Marc; Bastos, Pedro; Fornelli, Adele; Napoleon, Bertrand; Iglesias-Garcia, Julio; Seicean, Andrada; Larghi, Alberto; Hassan, Cesare; van Hooft, Jeanin E; Dumonceau, Jean-Marc

    2017-10-01

    For routine EUS-guided sampling of solid masses and lymph nodes (LNs) ESGE recommends 25G or 22G needles (high quality evidence, strong recommendation); fine needle aspiration (FNA) and fine needle biopsy (FNB) needles are equally recommended (high quality evidence, strong recommendation).When the primary aim of sampling is to obtain a core tissue specimen, ESGE suggests using 19G FNA or FNB needles or 22G FNB needles (low quality evidence, weak recommendation).ESGE recommends using 10-mL syringe suction for EUS-guided sampling of solid masses and LNs with 25G or 22G FNA needles (high quality evidence, strong recommendation) and other types of needles (low quality evidence, weak recommendation). ESGE suggests neutralizing residual negative pressure in the needle before withdrawing the needle from the target lesion (moderate quality evidence, weak recommendation).ESGE does not recommend for or against using the needle stylet for EUS-guided sampling of solid masses and LNs with FNA needles (high quality evidence, strong recommendation) and suggests using the needle stylet for EUS-guided sampling with FNB needles (low quality evidence, weak recommendation).ESGE suggests fanning the needle throughout the lesion when sampling solid masses and LNs (moderate quality evidence, weak recommendation).ESGE equally recommends EUS-guided sampling with or without on-site cytologic evaluation (moderate quality evidence, strong recommendation). When on-site cytologic evaluation is unavailable, ESGE suggests performance of three to four needle passes with an FNA needle or two to three passes with an FNB needle (low quality evidence, weak recommendation).For diagnostic sampling of pancreatic cystic lesions without a solid component, ESGE suggests emptying the cyst with a single pass of a 22G or 19G needle (low quality evidence, weak recommendation). For pancreatic cystic lesions with a solid component, ESGE suggests sampling of the solid component using the same technique as in the

  5. Stacked generalization: an introduction to super learning.

    Science.gov (United States)

    Naimi, Ashley I; Balzer, Laura B

    2018-04-10

    Stacked generalization is an ensemble method that allows researchers to combine several different prediction algorithms into one. Since its introduction in the early 1990s, the method has evolved several times into a host of methods among which is the "Super Learner". Super Learner uses V-fold cross-validation to build the optimal weighted combination of predictions from a library of candidate algorithms. Optimality is defined by a user-specified objective function, such as minimizing mean squared error or maximizing the area under the receiver operating characteristic curve. Although relatively simple in nature, use of Super Learner by epidemiologists has been hampered by limitations in understanding conceptual and technical details. We work step-by-step through two examples to illustrate concepts and address common concerns.

  6. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

    Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

  7. Time-predictable Stack Caching

    DEFF Research Database (Denmark)

    Abbaspourseyedi, Sahar

    completely. Thus, in systems with hard deadlines the worst-case execution time (WCET) of the real-time software running on them needs to be bounded. Modern architectures use features such as pipelining and caches for improving the average performance. These features, however, make the WCET analysis more...... addresses, provides an opportunity to predict and tighten the WCET of accesses to data in caches. In this thesis, we introduce the time-predictable stack cache design and implementation within a time-predictable processor. We introduce several optimizations to our design for tightening the WCET while...... keeping the timepredictability of the design intact. Moreover, we provide a solution for reducing the cost of context switching in a system using the stack cache. In design of these caches, we use custom hardware and compiler support for delivering time-predictable stack data accesses. Furthermore...

  8. Glassy carbon based supercapacitor stacks

    Energy Technology Data Exchange (ETDEWEB)

    Baertsch, M.; Braun, A.; Koetz, R.; Haas, O. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Considerable effort is being made to develop electrochemical double layer capacitors (EDLC) that store relatively large quantities of electrical energy and possess at the same time a high power density. Our previous work has shown that glassy carbon is suitable as a material for capacitor electrodes concerning low resistance and high capacity requirements. We present the development of bipolar electrochemical glassy carbon capacitor stacks of up to 3 V. Bipolar stacks are an efficient way to meet the high voltage and high power density requirements for traction applications. Impedance and cyclic voltammogram measurements are reported here and show the frequency response of a 1, 2, and 3 V stack. (author) 3 figs., 1 ref..

  9. Multiple Segmentation of Image Stacks

    DEFF Research Database (Denmark)

    Smets, Jonathan; Jaeger, Manfred

    2014-01-01

    We propose a method for the simultaneous construction of multiple image segmentations by combining a recently proposed “convolution of mixtures of Gaussians” model with a multi-layer hidden Markov random field structure. The resulting method constructs for a single image several, alternative...... segmentations that capture different structural elements of the image. We also apply the method to collections of images with identical pixel dimensions, which we call image stacks. Here it turns out that the method is able to both identify groups of similar images in the stack, and to provide segmentations...

  10. Simulating Small-Scale Object Stacking Using Stack Stability

    DEFF Research Database (Denmark)

    Kronborg Thomsen, Kasper; Kraus, Martin

    2015-01-01

    This paper presents an extension system to a closed-source, real-time physics engine for improving structured stacking behavior with small-scale objects such as wooden toy bricks. The proposed system was implemented and evaluated. The tests showed that the system is able to simulate several common...

  11. Pressurized electrolysis stack with thermal expansion capability

    Science.gov (United States)

    Bourgeois, Richard Scott

    2015-07-14

    The present techniques provide systems and methods for mounting an electrolyzer stack in an outer shell so as to allow for differential thermal expansion of the electrolyzer stack and shell. Generally, an electrolyzer stack may be formed from a material with a high coefficient of thermal expansion, while the shell may be formed from a material having a lower coefficient of thermal expansion. The differences between the coefficients of thermal expansion may lead to damage to the electrolyzer stack as the shell may restrain the thermal expansion of the electrolyzer stack. To allow for the differences in thermal expansion, the electrolyzer stack may be mounted within the shell leaving a space between the electrolyzer stack and shell. The space between the electrolyzer stack and the shell may be filled with a non-conductive fluid to further equalize pressure inside and outside of the electrolyzer stack.

  12. The Direct FuelCell™ stack engineering

    Science.gov (United States)

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

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

  13. Computerized plutonium laboratory-stack monitoring system

    International Nuclear Information System (INIS)

    Stafford, R.G.; DeVore, R.K.

    1977-01-01

    The Los Alamos Scientific Laboratory has recently designed and constructed a Plutonium Research and Development Facility to meet design criteria imposed by the United States Energy Research and Development Administration. A primary objective of the design criteria is to assure environmental protection and to reliably monitor plutonium effluent via the ventilation exhaust systems. A state-of-the-art facility exhaust air monitoring system is described which establishes near ideal conditions for evaluating plutonium activity in the stack effluent. Total and static pressure sensing manifolds are incorporated to measure average velocity and integrated total discharge air volume. These data are logged at a computer which receives instrument data through a multiplex scanning system. A multipoint isokinetic sampling assembly with associated instrumentation is described. Continuous air monitors have been designed to sample from the isokinetic sampling assembly and transmit both instantaneous and integrated stack effluent concentration data to the computer and various cathode ray tube displays. The continuous air monitors also serve as room air monitors in the plutonium facility with the primary objective of timely evacuation of personnel if an above tolerance airborne plutonium concentration is detected. Several continuous air monitors are incorporated in the ventilation system to assist in identification of release problem areas

  14. Stack semantics of type theory

    DEFF Research Database (Denmark)

    Coquand, Thierry; Mannaa, Bassel; Ruch, Fabian

    2017-01-01

    We give a model of dependent type theory with one univalent universe and propositional truncation interpreting a type as a stack, generalizing the groupoid model of type theory. As an application, we show that countable choice cannot be proved in dependent type theory with one univalent universe...

  15. Multilayer Piezoelectric Stack Actuator Characterization

    Science.gov (United States)

    Sherrit, Stewart; Jones, Christopher M.; Aldrich, Jack B.; Blodget, Chad; Bao, Xioaqi; Badescu, Mircea; Bar-Cohen, Yoseph

    2008-01-01

    Future NASA missions are increasingly seeking to use actuators for precision positioning to accuracies of the order of fractions of a nanometer. For this purpose, multilayer piezoelectric stacks are being considered as actuators for driving these precision mechanisms. In this study, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and extreme temperatures and voltages. AC signal testing included impedance, capacitance and dielectric loss factor of each actuator as a function of the small-signal driving sinusoidal frequency, and the ambient temperature. DC signal testing includes leakage current and displacement as a function of the applied DC voltage. The applied DC voltage was increased to over eight times the manufacturers' specifications to investigate the correlation between leakage current and breakdown voltage. Resonance characterization as a function of temperature was done over a temperature range of -180C to +200C which generally exceeded the manufacturers' specifications. In order to study the lifetime performance of these stacks, five actuators from one manufacturer were driven by a 60volt, 2 kHz sine-wave for ten billion cycles. The tests were performed using a Lab-View controlled automated data acquisition system that monitored the waveform of the stack electrical current and voltage. The measurements included the displacement, impedance, capacitance and leakage current and the analysis of the experimental results will be presented.

  16. Open stack thermal battery tests

    Energy Technology Data Exchange (ETDEWEB)

    Long, Kevin N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Christine C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grillet, Anne M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Headley, Alexander J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fenton, Kyle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wong, Dennis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ingersoll, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-04-17

    We present selected results from a series of Open Stack thermal battery tests performed in FY14 and FY15 and discuss our findings. These tests were meant to provide validation data for the comprehensive thermal battery simulation tools currently under development in Sierra/Aria under known conditions compared with as-manufactured batteries. We are able to satisfy this original objective in the present study for some test conditions. Measurements from each test include: nominal stack pressure (axial stress) vs. time in the cold state and during battery ignition, battery voltage vs. time against a prescribed current draw with periodic pulses, and images transverse to the battery axis from which cell displacements are computed. Six battery configurations were evaluated: 3, 5, and 10 cell stacks sandwiched between 4 layers of the materials used for axial thermal insulation, either Fiberfrax Board or MinK. In addition to the results from 3, 5, and 10 cell stacks with either in-line Fiberfrax Board or MinK insulation, a series of cell-free “control” tests were performed that show the inherent settling and stress relaxation based on the interaction between the insulation and heat pellets alone.

  17. Adding large EM stack support

    KAUST Repository

    Holst, Glendon

    2016-12-01

    Serial section electron microscopy (SSEM) image stacks generated using high throughput microscopy techniques are an integral tool for investigating brain connectivity and cell morphology. FIB or 3View scanning electron microscopes easily generate gigabytes of data. In order to produce analyzable 3D dataset from the imaged volumes, efficient and reliable image segmentation is crucial. Classical manual approaches to segmentation are time consuming and labour intensive. Semiautomatic seeded watershed segmentation algorithms, such as those implemented by ilastik image processing software, are a very powerful alternative, substantially speeding up segmentation times. We have used ilastik effectively for small EM stacks – on a laptop, no less; however, ilastik was unable to carve the large EM stacks we needed to segment because its memory requirements grew too large – even for the biggest workstations we had available. For this reason, we refactored the carving module of ilastik to scale it up to large EM stacks on large workstations, and tested its efficiency. We modified the carving module, building on existing blockwise processing functionality to process data in manageable chunks that can fit within RAM (main memory). We review this refactoring work, highlighting the software architecture, design choices, modifications, and issues encountered.

  18. The measurement of power reactor stack releases under accident conditions

    International Nuclear Information System (INIS)

    Stroem, L.

    1989-01-01

    The performance of a typical Swedish monitor for ventilation stack radioactivity releases is examined critically with respect to accident generated radioactive particles. The conditions in the stack, particle character, and the monitor design are considered. A large LOCA outside the containment leads to high relative humidity, and high temperature, or mist in the stack. A small external LOCA results in a moderate increase in temperature and humidity, and condensing conditions only with reduced ventilation. Particle size and stickiness are estimated for different types of accident. A particle is sticky if it adheres after contact with a solid, smooth, dry, and clean surface. The monitor performance is concluded to be poor for large, sticky particles, like mist droplets. Dense aerosols, like fire smoke, will plug the sampling filter. Non-sticky particles are generally sampled with acceptable accuracy. (au)

  19. Development and durability of SOFC stacks

    Energy Technology Data Exchange (ETDEWEB)

    Beeaff, D.; Dinesen, A.R.; Mikkelsen, Lars; Nielsen, Karsten A.; Solvang, M.; Hendriksen, Peter V.

    2004-12-01

    The present project is a part of the Danish SOFC programme, which has the overall aim of establishing a Danish production of SOFC - cells, stacks and systems for economical and environmentally friendly power production. The aim of the present project was to develop and demonstrate (on a small scale, few cells, few thousand hours) a durable, thermally cyclable stack with high performance at 750 deg. C. Good progress towards this target has been made and demonstrated at the level of stack-elements (one cell between two interconnects) or small stacks (3 5 cells). Three different stacks or stack-elements have been operated for periods exceeding 3000 hr. The work has covered development of stack-components (seals, interconnects, coatings, contact layers), establishment of procedures for stack assembly and initiation, and detailed electrical characterisation with the aims of identifying performance limiting factors as well as long term durability. Further, post test investigations have been carried out to identify possible degradation mechanisms. (BA)

  20. Productivity Measurement Of Technical Institute

    Directory of Open Access Journals (Sweden)

    Miss.Pooja Yadav

    2015-05-01

    Full Text Available Abstract The increasing concern over globalization between other things has made the achievement of lifetime skills vital for all classes of people. Achievement of such skills can be developed from technical education programs in the advance of any nation. Skill gaining provides knowledge and inculcates the approaches that are essential for arrival and progress into an occupation. When skills are developed in any occupation it will provide and improve the standard of living with the cover beside poverty thereby behind national development. This paper observes sampling distribution and moving average concept that how technical education can generate the required skills the significance of skill acquisition its roles benefits and sustainability in national development. It also mentions among others that government should look into and improve productivity that can encourage skill achievement for the youths. The solutions are divided the sampling box into few group before stacking up workstation and use table and some other wood product. Cost reduction for each solution was intended and the solution with highest cost decrease is chosen to increase the productivity of the college.

  1. Traileka Glacier X-Stack. Final Scientific/Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Borkar, Shekhar [Intel Federal LLC, Fairfax, VA (United States)

    2015-09-01

    The XStack Traleika Glacier (XSTG) project was a three-year research award for exploring a revolutionary exascale-class machine software framework. The XSTG program, including Intel, UC San Diego, Pacific Northwest National Lab, UIUC, Rice University, Reservoir Labs, ET International, and U. Delaware, had major accomplishments, insights, and products resulting from this three-year effort.

  2. Stacking faults and microstructural parameters in non-mulberry silk ...

    Indian Academy of Sciences (India)

    Then the whole pattern fitting was done by introducing weight factors for the individual profiles and also taking into account the average stacking faults derived using eqs (4) and (5) in the final stage of refinement with the whole experimental diffraction data of the sample. Computational procedure is given in the flow chart ...

  3. Lightweight Stacks of Direct Methanol Fuel Cells

    Science.gov (United States)

    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.

  4. UMTRA water sampling technical (peer) review. Responses to observations, comments, and recommendations submitted by C. Warren Ankerberg (Geraghty ampersand Miller, Inc.)

    International Nuclear Information System (INIS)

    1993-08-01

    At the request of the Office of Independent Technical Review for the U.S. Department of Energy (DOE), Uranium Mill Tailings Remedial Action (UMTRA) Project, an independent technical review (peer review) was conducted during the period of September 15-17, 1992. The review was conducted by C. Warren Ankerberg (Geraghty ampersand Miller, Inc., Tampa, Florida) and Don Messinger (Roy F. Weston, Inc., West Chester, Pennsylvania). The peer review included a review of written documentation [water sampling standard operating procedures (SOP)], an inspection of technical reports and other deliverables, a review of staff qualifications and training, and a field visit to evaluate the compliance of field procedures with SOPs. The approach of the peer reviewers was to verify that the program meets the following criteria: Reported results are traceable to and consistent with recorded data. The basic assumptions and acceptance criteria are valid. Data are traceable to their origin and to reported analytical results. The procedures employed are consistent both internally and externally with written SOPs and regulatory guidelines. Inferences and conclusions are soundly based. The procedures and/or reports generated present work that satisfies the local, state and/or Federal regulatory requirements as applicable. The approach is consistent with industry standards and/or state-of-the-art technology, as practical. The data generated by activities are legally defensible and technically sound. UMTRA staff are adequately trained and qualified for the work. This document is a response to the observations, comments, and recommendations submitted by C. Warren Ankerberg following his review. The format of this document is to present the findings and recommendations verbatim from Mr. Ankerberg's report, followed by responses from the UMTRA Project staff. Included in the responses from the UMTRA Project staff are recommended changes in SOPs and strategies for implementing the changes

  5. Solid Oxide Fuel Cell Stack Diagnostics

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Barfod, Rasmus Gottrup

    . An operating stack is subject to compositional gradients in the gaseous reactant streams, and temperature gradients across each cell and across the stack, which complicates detailed analysis. Several experimental stacks from Topsoe Fuel Cell A/S were characterized using Electrochemical Impedance Spectroscopy...... (EIS). The stack measurement geometry was optimized for EIS by careful selection of the placement of current feeds and voltage probes in order to minimize measurement errors. It was demonstrated that with the improved placement of current feeds and voltage probes it is possible to separate the loss...... in the hydrogen fuel gas supplied to the stack. EIS was used to examine the long-term behavior and monitor the evolution of the impedance of each of the repeating units and the whole stack. The observed impedance was analyzed in detail for one of the repeating units and the whole stack and the losses reported...

  6. Evolution of the Lunar Receiving Laboratory to the Astromaterial Sample Curation Facility: Technical Tensions Between Containment and Cleanliness, Between Particulate and Organic Cleanliness

    Science.gov (United States)

    Allton, J. H.; Zeigler, R. A.; Calaway, M. J.

    2016-01-01

    The Lunar Receiving Laboratory (LRL) was planned and constructed in the 1960s to support the Apollo program in the context of landing on the Moon and safely returning humans. The enduring science return from that effort is a result of careful curation of planetary materials. Technical decisions for the first facility included sample handling environment (vacuum vs inert gas), and instruments for making basic sample assessment, but the most difficult decision, and most visible, was stringent biosafety vs ultra-clean sample handling. Biosafety required handling of samples in negative pressure gloveboxes and rooms for containment and use of sterilizing protocols and animal/plant models for hazard assessment. Ultra-clean sample handling worked best in positive pressure nitrogen environment gloveboxes in positive pressure rooms, using cleanable tools of tightly controlled composition. The requirements for these two objectives were so different, that the solution was to design and build a new facility for specific purpose of preserving the scientific integrity of the samples. The resulting Lunar Curatorial Facility was designed and constructed, from 1972-1979, with advice and oversight by a very active committee comprised of lunar sample scientists. The high precision analyses required for planetary science are enabled by stringent contamination control of trace elements in the materials and protocols of construction (e.g., trace element screening for paint and flooring materials) and the equipment used in sample handling and storage. As other astromaterials, especially small particles and atoms, were added to the collections curated, the technical tension between particulate cleanliness and organic cleanliness was addressed in more detail. Techniques for minimizing particulate contamination in sample handling environments use high efficiency air filtering techniques typically requiring organic sealants which offgas. Protocols for reducing adventitious carbon on sample

  7. Technical note: Could benzalkonium chloride be a suitable alternative to mercuric chloride for preservation of seawater samples?

    Science.gov (United States)

    Gloël, J.; Robinson, C.; Tilstone, G. H.; Tarran, G.; Kaiser, J.

    2015-12-01

    Instrumental equipment unsuitable or unavailable for fieldwork as well as lack of ship space can necessitate the preservation of seawater samples prior to analysis in a shore-based laboratory. Mercuric chloride (HgCl2) is routinely used for such preservation, but its handling and subsequent disposal incur environmental risks and significant expense. There is therefore a strong motivation to find less hazardous alternatives. Benzalkonium chloride (BAC) has been used previously as microbial inhibitor for freshwater samples. Here, we assess the use of BAC for marine samples prior to the measurement of oxygen-to-argon (O2 / Ar) ratios, as used for the determination of biological net community production. BAC at a concentration of 50 mg dm-3 inhibited microbial activity for at least 3 days in samples tested with chlorophyll a (Chl a) concentrations up to 1 mg m-3. BAC concentrations of 100 and 200 mg dm-3 were no more effective than 50 mg dm-3. With fewer risks to human health and the environment, and no requirement for expensive waste disposal, BAC could be a viable alternative to HgCl2 for short-term preservation of seawater samples, but is not a replacement for HgCl2 in the case of oxygen triple isotope analysis, which requires storage over weeks to months. In any event, further tests on a case-by-case basis should be undertaken if use of BAC was considered, since its inhibitory activity may depend on concentration and composition of the microbial community.

  8. The influence of environment on corrosion of cast iron and carbon steel representing samples of outdoor metal technical heritage

    Science.gov (United States)

    Strzelec, M.; Marczak, J.; Skrzeczanowski, W.; Zatorska, A.; Sarzynski, A.; Czyz, K.; Zasada, D.

    2015-06-01

    This paper presents the results of annual measurements of the corrosion progress at test samples of cast iron and carbon steel placed in different natural environments. Comparative tests were performed in two outdoor stations, one at the Railway Museum in central Warsaw and one at the location of a Railway Museum in the small town of Sochaczew, 50 km west of Warsaw. The influence of surface roughness on the development of corrosion was determined by two kinds of treatment of all sample surfaces - metal brush or grinding. Stratigraphy and composition of corrosion products in quarterly periods were analyzed with laser-induced breakdown spectroscopy (LIBS) and Raman laser spectroscopy. Comparative tests were performed using a scanning electron microscopy (SEM) system equipped with energy dispersive spectrometer (EDS) and micro-chemical analytical methods. The corrosion layers on carbon steel have proven to be thicker on average than on cast iron, and thicker on the brushed parts of both materials. Furthermore, a thicker corrosion layer was found on the cast iron test samples exposed in Sochaczew than in Warsaw. Different iron oxides, namely lepidocrocite, goethite, hematite and magnetite were identified in the surface Raman spectra of corrosion layers, the last compound only in the sample from Sochaczew. SEM EDS measurements of surface elemental concentrations showed a higher concentration of sulfur in all samples from Sochaczew. Registered LIBS spectra have been additionally analyzed with statistical approach, using Factorial Analysis (FA). Results generally confirmed conclusions drawn from SEM/Raman/LIBS results.

  9. Stacking and discontinuous buffers in capillary zone electrophoresis.

    Science.gov (United States)

    Shihabi, Z K

    2000-08-01

    Discontinuous buffers for capillary zone electrophoresis (CZE) can be used under less rigid conditions compared to those for isotachophoresis for stacking. They can be prepared simply by modifying the sample itself, either by addition of small inorganic ions, low conductivity diluents, or both, and also by adjusting its pH, meanwhile injecting a large volume on the capillary. Zwitterionic and organic-based buffers such as triethanolamine and tris(hydroxymethyl)aminomethane (Tris) are well suited for stacking due to their low conductivity, provided the buffer is discontinuous as demonstrated here. A simple mechanism based on discontinuous buffers is described to explain many of the observed stacking types in CZE, pointing out the many similarities to transient isotachophoresis.

  10. Aquatic invertebrate sampling at selected outfalls in Operable Unit 1082; Technical areas 9, 11, 16 and 22

    Energy Technology Data Exchange (ETDEWEB)

    Cross, S.

    1995-09-01

    The Ecological Studies Team (EST) of ESH-20 at Los Alamos National Laboratory conducted preliminary aquatic sampling at outfalls within Operable Unit 1082 and nearby natural waterways. Eleven outfalls were sampled a total of eighteen times. Three natural waterways (upper Pajarito Canyon, Starmer`s Gulch, and Bulldog Spring) in the vicinity were sampled a total of six times. At most sites, EST recorded hydrological condition, physico-chemical parameters, wildlife uses, and vegetation. At each outfall with water and each natural waterway, EST collected an aquatic invertebrate sample which was analyzed by taxa composition, Wilhm`s biodiversity index, the community tolerance quotient (CTQ), and density. The physico-chemical parameters at most outfalls and natural waterways fell within the normal range of natural waters in the area. However, the outfalls are characterized by low biodiversity and severely stressed communities composed of a restricted number of taxa. The habitat at the other outfalls could probably support well-developed aquatic communities if sufficient water was available. At present, the hydrology at these outfalls is too slight and/or sporadic to support such a community in the foreseeable future. In contrast to the outfalls, the natural waterways of the area had greater densities of aquatic invertebrates, higher biodiversities, and lower CTQs.

  11. ZPEG: a hybrid DPCM-DCT based approach for compression of Z-stack images.

    Science.gov (United States)

    Khire, Sourabh; Cooper, Lee; Park, Yuna; Carter, Alexis; Jayant, Nikil; Saltz, Joel

    2012-01-01

    Modern imaging technology permits obtaining images at varying depths along the thickness, or the Z-axis of the sample being imaged. A stack of multiple such images is called a Z-stack image. The focus capability offered by Z-stack images is critical for many digital pathology applications. A single Z-stack image may result in several hundred gigabytes of data, and needs to be compressed for archival and distribution purposes. Currently, the existing methods for compression of Z-stack images such as JPEG and JPEG 2000 compress each focal plane independently, and do not take advantage of the Z-signal redundancy. It is possible to achieve additional compression efficiency over the existing methods, by exploiting the high Z-signal correlation during image compression. In this paper, we propose a novel algorithm for compression of Z-stack images, which we term as ZPEG. ZPEG extends the popular discrete-cosine transform (DCT) based image encoder to compress Z-stack images. This is achieved by decorrelating the neighboring layers of the Z-stack image using differential pulse-code modulation (DPCM). PSNR measurements, as well as subjective evaluations by experts indicate that ZPEG can encode Z-stack images at a higher quality as compared to JPEG, JPEG 2000 and JP3D at compression ratios below 50∶1.

  12. Analyses of Large Coal-Based SOFCs for High Power Stack Block Development

    Energy Technology Data Exchange (ETDEWEB)

    Recknagle, Kurtis P; Koeppel, Brian J

    2010-10-01

    This report summarizes the numerical modeling and analytical efforts for SOFC stack development performed for the coal-based SOFC program. The stack modeling activities began in 2004, but this report focuses on the most relevant results obtained since August 2008. This includes the latter half of Phase-I and all of Phase-II activities under technical guidance of VPS and FCE. The models developed to predict the thermal-flow-electrochemical behaviors and thermal-mechanical responses of generic planar stacks and towers are described. The effects of cell geometry, fuel gas composition, on-cell reforming, operating conditions, cell performance, seal leak, voltage degradation, boundary conditions, and stack height are studied. The modeling activities to evaluate and achieve technical targets for large stack blocks are described, and results from the latest thermal-fluid-electrochemical and structural models are summarized. Modeling results for stack modifications such as scale-up and component thickness reduction to realize cost reduction are presented. Supporting modeling activities in the areas of cell fabrication and loss of contact are also described.

  13. Vertically stacked nanocellulose tactile sensor.

    Science.gov (United States)

    Jung, Minhyun; Kim, Kyungkwan; Kim, Bumjin; Lee, Kwang-Jae; Kang, Jae-Wook; Jeon, Sanghun

    2017-11-16

    Paper-based electronic devices are attracting considerable attention, because the paper platform has unique attributes such as flexibility and eco-friendliness. Here we report on what is claimed to be the firstly fully integrated vertically-stacked nanocellulose-based tactile sensor, which is capable of simultaneously sensing temperature and pressure. The pressure and temperature sensors are operated using different principles and are stacked vertically, thereby minimizing the interference effect. For the pressure sensor, which utilizes the piezoresistance principle under pressure, the conducting electrode was inkjet printed on the TEMPO-oxidized-nanocellulose patterned with micro-sized pyramids, and the counter electrode was placed on the nanocellulose film. The pressure sensor has a high sensitivity over a wide range (500 Pa-3 kPa) and a high durability of 10 4 loading/unloading cycles. The temperature sensor combines various materials such as poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), silver nanoparticles (AgNPs) and carbon nanotubes (CNTs) to form a thermocouple on the upper nanocellulose layer. The thermoelectric-based temperature sensors generate a thermoelectric voltage output of 1.7 mV for a temperature difference of 125 K. Our 5 × 5 tactile sensor arrays show a fast response, negligible interference, and durable sensing performance.

  14. Technical management plan for sample generation, analysis, and data review for Phase 2 of the Clinch River Environmental Restoration Program

    International Nuclear Information System (INIS)

    Brandt, C.C.; Benson, S.B.; Beeler, D.A.

    1994-03-01

    The Clinch River Remedial Investigation (CRRI) is designed to address the transport, fate, and distribution of waterborne contaminants (radionuclides, metals, and organic compounds) released from the US Department of Energy's (DOE's) Oak Ridge Reservation (ORR) and to assess potential risks to human health and the environment associated with these contaminants. The remedial investigation is entering Phase 2, which has the following items as its objectives: define the nature and extent of the contamination in areas downstream from the DOE ORR, evaluate the human health and ecological risks posed by these contaminants, and perform preliminary identification and evaluation of potential remediation alternatives. This plan describes the requirements, responsibilities, and roles of personnel during sampling, analysis, and data review for the Clinch River Environmental Restoration Program (CR-ERP). The purpose of the plan is to formalize the process for obtaining analytical services, tracking sampling and analysis documentation, and assessing the overall quality of the CR-ERP data collection program to ensure that it will provide the necessary building blocks for the program decision-making process

  15. Generalized data stacking programming model with applications

    Directory of Open Access Journals (Sweden)

    Hala Samir Elhadidy

    2016-09-01

    Full Text Available Recent researches have shown that, everywhere in various sciences the systems are following stacked-based stored change behavior when subjected to events or varying environments “on and above” their normal situations. This paper presents a generalized data stack programming (GDSP model which is developed to describe the system changes under varying environment. These changes which are captured with different ways such as sensor reading are stored in matrices. Extraction algorithm and identification technique are proposed to extract the different layers between images and identify the stack class the object follows; respectively. The general multi-stacking network is presented including the interaction between various stack-based layering of some applications. The experiments prove that the concept of stack matrix gives average accuracy of 99.45%.

  16. Development of internal manifold heat exchanger (IMHEX reg-sign) molten carbonate fuel cell stacks

    International Nuclear Information System (INIS)

    Marianowski, L.G.; Ong, E.T.; Petri, R.J.; Remick, R.J.

    1991-01-01

    The Institute of Gas Technology (IGT) has been in the forefront of molten carbonate fuel cell (MCFC) development for over 25 years. Numerous cell designs have been tested and extensive tests have been performed on a variety of gas manifolding alternatives for cells and stacks. Based upon the results of these performance tests, IGT's development efforts started focusing on an internal gas manifolding concept. This work, initiated in 1988, is known today as the IMHEX reg-sign concept. MCP has developed a comprehensive commercialization program loading to the sale of commercial units in 1996. MCP's role is in the manufacture of stack components, stack assembly, MCFC subsystem testing, and the design, marketing and construction of MCFC power plants. Numerous subscale (1 ft 2 ) stacks have been operated containing between 3 and 70 cells. These tests verified and demonstrated the viability of internal manifolding from technical (no carbonate pumping), engineering (relaxed part dimensional tolerance requirements), and operational (good gas sealing) aspects. Simplified fabrication, ease of assembly, the elimination of external manifolds and all associated clamping requirements has significantly lowered anticipated stack costs. Ongoing 1 ft 2 stack testing is generating performance and endurance characteristics as a function of system specified operating conditions. Commercial-sized, full-area stacks (10 ft 2 ) are in the process of being assembled and will be tested in November. This paper will review the recent developments the MCFC scale-up and manufacture work of MCP, and the research and development efforts of IGT which support those efforts. 17 figs

  17. SeaWiFS technical report series. Volume 4: An analysis of GAC sampling algorithms. A case study

    Science.gov (United States)

    Yeh, Eueng-Nan (Editor); Hooker, Stanford B. (Editor); Hooker, Stanford B. (Editor); Mccain, Charles R. (Editor); Fu, Gary (Editor)

    1992-01-01

    The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) instrument will sample at approximately a 1 km resolution at nadir which will be broadcast for reception by realtime ground stations. However, the global data set will be comprised of coarser four kilometer data which will be recorded and broadcast to the SeaWiFS Project for processing. Several algorithms for degrading the one kilometer data to four kilometer data are examined using imagery from the Coastal Zone Color Scanner (CZCS) in an effort to determine which algorithm would best preserve the statistical characteristics of the derived products generated from the one kilometer data. Of the algorithms tested, subsampling based on a fixed pixel within a 4 x 4 pixel array is judged to yield the most consistent results when compared to the one kilometer data products.

  18. Flexural characteristics of a stack leg

    International Nuclear Information System (INIS)

    Cook, J.

    1979-06-01

    A 30 MV tandem Van de Graaff accelerator is at present under construction at Daresbury Laboratory. The insulating stack of the machine is of modular construction, each module being 860 mm in length. Each live section stack module contains 8 insulating legs mounted between bulkhead rings. The design, fabrication (from glass discs bonded to stainless steel discs using an epoxy film adhesive) and testing of the stack legs is described. (U.K.)

  19. Hydrogen Embrittlement And Stacking-Fault Energies

    Science.gov (United States)

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

    1988-01-01

    Embrittlement in Ni/Cu alloys appears related to stacking-fault porbabilities. Report describes attempt to show a correlation between stacking-fault energy of different Ni/Cu alloys and susceptibility to hydrogen embrittlement. Correlation could lead to more fundamental understanding and method of predicting susceptibility of given Ni/Cu alloy form stacking-fault energies calculated from X-ray diffraction measurements.

  20. Stacks of SPS Dipole Magnets

    CERN Multimedia

    1974-01-01

    Stacks of SPS Dipole Magnets ready for installation in the tunnel. The SPS uses a separated function lattice with dipoles for bending and quadrupoles for focusing. The 6.2 m long normal conducting dipoles are of H-type with coils that are bent-up at the ends. There are two types, B1 (total of 360) and B2 (384). Both are for a maximum field of 1.8 Tesla and have the same outer dimensions (450x800 mm2 vxh) but with different gaps (B1: 39x129 mm2, B2: 52x92 mm2) tailored to the beam size. The yoke, made of 1.5 mm thick laminations, consists of an upper and a lower half joined together in the median plane once the coils have been inserted.

  1. California dreaming?[PEM stacks

    Energy Technology Data Exchange (ETDEWEB)

    Crosse, J.

    2002-06-01

    Hyundai's Santa Fe FCEV will be on sale by the end of 2002. Hyundai uses PEM stacks that are manufactured by International Fuel Cells (IFC), a division of United Technologies. Santa Fe is equipped with a 65 kW electric powertrain of Enova systems and Shell's new gasoline reformer called Hydrogen Source. Eugene Jang, Senior Engineer - Fuel Cell and Materials at Hyundai stated that the compressor related losses on IFC system are below 3%. The maximum speed offered by the vehicle is estimated as 123km/hr while the petrol equivalent fuel consumption is quoted between 5.6L/100 km and 4.8L/100 km. Santa Fe is a compact vehicle offering better steering response and a pleasant drive. (author)

  2. Stacking technology for a space constrained microsystem

    DEFF Research Database (Denmark)

    Heschel, Matthias; Kuhmann, Jochen Friedrich; Bouwstra, Siebe

    1998-01-01

    In this paper we present a stacking technology for an integrated packaging of an intelligent transducer which is formed by a micromachined silicon transducer and an integrated circuit chip. Transducer and circuitry are stacked on top of each other with an intermediate chip in between. The bonding...

  3. Vector Fields and Flows on Differentiable Stacks

    DEFF Research Database (Denmark)

    A. Hepworth, Richard

    2009-01-01

    This paper introduces the notions of vector field and flow on a general differentiable stack. Our main theorem states that the flow of a vector field on a compact proper differentiable stack exists and is unique up to a uniquely determined 2-cell. This extends the usual result on the existence...... of vector fields....

  4. Learning OpenStack networking (Neutron)

    CERN Document Server

    Denton, James

    2014-01-01

    If you are an OpenStack-based cloud operator with experience in OpenStack Compute and nova-network but are new to Neutron networking, then this book is for you. Some networking experience is recommended, and a physical network infrastructure is required to provide connectivity to instances and other network resources configured in the book.

  5. On the "stacking fault" in copper

    NARCIS (Netherlands)

    Fransens, J.R.; Pleiter, F

    2003-01-01

    The results of a perturbed gamma-gamma angular correlations experiment on In-111 implanted into a properly cut single crystal of copper show that the defect known in the literature as "stacking fault" is not a planar faulted loop but a stacking fault tetrahedron with a size of 10-50 Angstrom.

  6. Regional and global atmospheric aerosol studies using the ''Gent'' stacked filter unit sampler and other aerosol collectors, with multi-elemental analysis of the samples by nuclear-related analytical techniques

    International Nuclear Information System (INIS)

    Maenhaut, W.; Francois, F.; Salma, I.; Cafmeyer, J.; Gilot, C.

    1994-01-01

    The ''Gent'' staked filter unit sampler and other collection devices are used in regional and global scale studies on the tropospheric atmospheric aerosols, its composition, sources and fate. The aerosol samples are analyzed by particle-induced X-ray emission analysis, instrumental neutron activation analysis, ion chromatography, a light reflectance technique (for determining black carbon), and gravimetry (for measuring the particular mass). In evaluating the data, use is made of receptor modelling techniques, transport models and wind sector analysis, and also of air mass trajectories and other meteorological information. Preliminary results from a long-term study in southern Norway are presented. It is suggested that the anthropogenic and soil dust aerosol components are mainly adverted to southern Norway by long-range transport and that the major fraction of the submicrometer particle mass is from anthropogenic origin. Preliminary results are also presented for an intensive study in southern Africa. On the basis of the data for two sites (about 40 km apart) in the Kruger National Park it was concluded that regionally representative aerosol samples were collected and that the biomass burning products account for more than 50% of the fine particle mass. Finally, our plans for future work are given. (author). 70 refs, 4 figs, 1 tab

  7. Status of MCFC stack technology at IHI

    Energy Technology Data Exchange (ETDEWEB)

    Hosaka, M.; Morita, T.; Matsuyama, T.; Otsubo, M. [Ishikawajima-Harima Heavy Industries Co., Ltd., Tokyo (Japan)

    1996-12-31

    The molten carbonate fuel cell (MCFC) is a promising option for highly efficient power generation possible to enlarge. IHI has been studying parallel flow MCFC stacks with internal manifolds that have a large electrode area of 1m{sup 2}. IHI will make two 250 kW stacks for MW plant, and has begun to make cell components for the plant. To improve the stability of stack, soft corrugated plate used in the separator has been developed, and a way of gathering current from stacks has been studied. The DC output potential of the plant being very high, the design of electric insulation will be very important. A 20 kW short stack test was conducted in 1995 FY to certificate some of the improvements and components of the MW plant. These activities are presented below.

  8. The impact of stack geometry and mean pressure on cold end temperature of stack in thermoacoustic refrigeration systems

    Science.gov (United States)

    Wantha, Channarong

    2018-02-01

    This paper reports on the experimental and simulation studies of the influence of stack geometries and different mean pressures on the cold end temperature of the stack in the thermoacoustic refrigeration system. The stack geometry was tested, including spiral stack, circular pore stack and pin array stack. The results of this study show that the mean pressure of the gas in the system has a significant impact on the cold end temperature of the stack. The mean pressure of the gas in the system corresponds to thermal penetration depth, which results in a better cold end temperature of the stack. The results also show that the cold end temperature of the pin array stack decreases more than that of the spiral stack and circular pore stack geometry by approximately 63% and 70%, respectively. In addition, the thermal area and viscous area of the stack are analyzed to explain the results of such temperatures of thermoacoustic stacks.

  9. Density of oxidation-induced stacking faults in damaged silicon

    NARCIS (Netherlands)

    Kuper, F.G.; Hosson, J.Th.M. De; Verwey, J.F.

    1986-01-01

    A model for the relation between density and length of oxidation-induced stacking faults on damaged silicon surfaces is proposed, based on interactions of stacking faults with dislocations and neighboring stacking faults. The model agrees with experiments.

  10. Tunable electro-optic filter stack

    Energy Technology Data Exchange (ETDEWEB)

    Fontecchio, Adam K.; Shriyan, Sameet K.; Bellingham, Alyssa

    2017-09-05

    A holographic polymer dispersed liquid crystal (HPDLC) tunable filter exhibits switching times of no more than 20 microseconds. The HPDLC tunable filter can be utilized in a variety of applications. An HPDLC tunable filter stack can be utilized in a hyperspectral imaging system capable of spectrally multiplexing hyperspectral imaging data acquired while the hyperspectral imaging system is airborne. HPDLC tunable filter stacks can be utilized in high speed switchable optical shielding systems, for example as a coating for a visor or an aircraft canopy. These HPDLC tunable filter stacks can be fabricated using a spin coating apparatus and associated fabrication methods.

  11. Dynamical stability of slip-stacking particles

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, Jeffrey; Zwaska, Robert

    2014-09-01

    We study the stability of particles in slip-stacking configuration, used to nearly double proton beam intensity at Fermilab. We introduce universal area factors to calculate the available phase space area for any set of beam parameters without individual simulation. We find perturbative solutions for stable particle trajectories. We establish Booster beam quality requirements to achieve 97% slip-stacking efficiency. We show that slip-stacking dynamics directly correspond to the driven pendulum and to the system of two standing-wave traps moving with respect to each other.

  12. Stacking faults in austempered ductile iron

    Energy Technology Data Exchange (ETDEWEB)

    Hermida, J.D. [CNEA, San Martin (Argentina). Dept. de Materiales

    1996-06-01

    During last decade, Austempered Ductile Iron (ADI) has been successfully used as an acceptable replacement material for steel in many applications, due to the relatively high strength and reasonable ductility obtained. These properties are the result of the special microstructure exhibited by this material at the end of the upper bainite reaction: ferrite platelets surrounded by high carbon stabilized austenite. However, at the beginning of the austempering treatment, the existence of interdendritic low carbon austenite is revealed by its transformation to martensite when cooling the sample or during subsequent deformation. The completion of the upper bainite reaction is of decisive importance to mechanical properties because the remaining martensite reduces ductility. It was observed that the rate of the upper bainite reaction is governed by the carbon content difference between the low and high carbon austenites. The carbon content is obtained by the lattice parameter measurement, because there exists a known expression that relates both magnitudes. Several works have used X-ray diffraction to measure the lattice parameter and phase concentrations as a function of austempering time. In these works, the lattice parameters were obtained directly from the {l_brace}220{r_brace} and {l_brace}311{r_brace} peaks position. The purpose of this work is to show more precise lattice parameters measurement and, very closely related to this, the existence of stacking faults in austenite, even at times within the processing window.

  13. Technical change to the work plan for the remedial investigation of the Salmon Site, Lamar County, Mississippi: Sampling and analysis plan background soil and groundwater study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    The Salmon Site, formerly known as the Tatum Dome Test Site, is located in south-central Mississippi, southwest of the city of Hattiesburg, in Lamar County. Between 1964 and 1970, two nuclear and two non-nuclear gas explosions were conducted deep underground in the Tatum Salt Dome beneath the site. The tests were performed as part of the former US Atomic Energy Commission`s Vela Uniform Program which was conducted to improve the United States` capability to detect underground nuclear explosions. This document details technical changes to the existing work plan for the remedial investigation of the Salmon Site. A previously conducted Remedial Investigation for the Salmon Site involved the preparation of ecological and human health risk assessments. These risk assessments, which are incorporated into the Remedial Investigation Report, identified several constituents of potential concern (COPC) that could potentially have a negative impact on ecological and human health. These COPC are the primary risk drivers for the Salmon Site; they include arsenic and naturally occurring, gamma-emitting radionuclides. If it can be demonstrated that similar concentrations of these COPCs occur naturally in surrounding areas, they can be removed from consideration in the risk assessments. The purpose of this sampling effort is to collect enough data to prove that the COPCs are naturally occurring and are not a result of the explosives testing activities conducted at the site. This will be accomplished by collecting enough soil samples to have a statistically valid population that can be used to produce defensible comparisons that prove the concentrations identified on site are the same as the background concentrations in surrounding areas.

  14. Wearable solar cells by stacking textile electrodes.

    Science.gov (United States)

    Pan, Shaowu; Yang, Zhibin; Chen, Peining; Deng, Jue; Li, Houpu; Peng, Huisheng

    2014-06-10

    A new and general method to produce flexible, wearable dye-sensitized solar cell (DSC) textiles by the stacking of two textile electrodes has been developed. A metal-textile electrode that was made from micrometer-sized metal wires was used as a working electrode, while the textile counter electrode was woven from highly aligned carbon nanotube fibers with high mechanical strengths and electrical conductivities. The resulting DSC textile exhibited a high energy conversion efficiency that was well maintained under bending. Compared with the woven DSC textiles that are based on wire-shaped devices, this stacked DSC textile unexpectedly exhibited a unique deformation from a rectangle to a parallelogram, which is highly desired in portable electronics. This lightweight and wearable stacked DSC textile is superior to conventional planar DSCs because the energy conversion efficiency of the stacked DSC textile was independent of the angle of incident light. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. STACKING FAULT ENERGY IN HIGH MANGANESE ALLOYS

    Directory of Open Access Journals (Sweden)

    Eva Mazancová

    2009-04-01

    Full Text Available Stacking fault energy of high manganese alloys (marked as TWIP and TRIPLEX is an important parameter determining deformation mechanism type realized in above mentioned alloys. Stacking fault energy level can be asserted with a gliding of partial and/or full dislocations, b gliding mechanism and twinning deformation process in connection with increasing of fracture deformation level (deformation elongation and with increasing of simultaneously realized work hardening proces., c gliding mechanism and deformation induced e-martensite formation. In contribution calculated stacking fault energies are presented for various chemical compositions of high manganese alloys. Stacking fault energy dependences on manganese, carbon, iron and alluminium contents are presented. Results are confronted with some accessible papers.The aim of work is to deepen knowledge of presented data. The TWIP and TRIPLEX alloys can be held for promissing new automotive materials.

  16. Stack-Based Typed Assembly Language

    National Research Council Canada - National Science Library

    Morrisett, Greg

    1998-01-01

    .... This paper also formalizes the typing connection between CPS based compilation and stack based compilation and illustrates how STAL can formally model calling conventions by specifying them as formal translations of source function types to STAL types.

  17. Characterization of Piezoelectric Stacks for Space Applications

    Science.gov (United States)

    Sherrit, Stewart; Jones, Christopher; Aldrich, Jack; Blodget, Chad; Bao, Xiaoqi; Badescu, Mircea; Bar-Cohen, Yoseph

    2008-01-01

    Future NASA missions are increasingly seeking to actuate mechanisms to precision levels in the nanometer range and below. Co-fired multilayer piezoelectric stacks offer the required actuation precision that is needed for such mechanisms. To obtain performance statistics and determine reliability for extended use, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and high temperatures and voltages. In order to study the lifetime performance of these stacks, five actuators were driven sinusoidally for up to ten billion cycles. An automated data acquisition system was developed and implemented to monitor each stack's electrical current and voltage waveforms over the life of the test. As part of the monitoring tests, the displacement, impedance, capacitance and leakage current were measured to assess the operation degradation. This paper presents some of the results of this effort.

  18. The stack on software and sovereignty

    CERN Document Server

    Bratton, Benjamin H

    2016-01-01

    A comprehensive political and design theory of planetary-scale computation proposing that The Stack -- an accidental megastructure -- is both a technological apparatus and a model for a new geopolitical architecture.

  19. Stacked spaces: Mapping digital infrastructures

    Directory of Open Access Journals (Sweden)

    Till Straube

    2016-09-01

    Full Text Available This article turns towards the spatial life of ‘digital infrastructures’, i.e. code, protocols, standards, and data formats that are hidden from view in everyday applications of computational technologies. It does so by drawing on the version control system Git as a case study, and telling the story of its initial development in order to reconstruct the circumstances and technical considerations surrounding its conception. This account engages with computational infrastructures on their own terms by adopting the figure of the ‘stack’ to frame a technically informed analysis, and exploring its implications for a different kind of geographic inquiry. Drawing on topology as employed by Law and Mol, attention is given to the multiplicity of spatialities and temporalities enrolled in digital infrastructures in general, and Git specifically. Along the lines of the case study and by reading it against other literatures, this notion of topology is expanded to include the material performation of fundamentally arbitrary, more-than-human topologies, as well as their nested articulation, translation and negotiation within digital infrastructures.

  20. Environmental Modeling Framework using Stacked Gaussian Processes

    OpenAIRE

    Abdelfatah, Kareem; Bao, Junshu; Terejanu, Gabriel

    2016-01-01

    A network of independently trained Gaussian processes (StackedGP) is introduced to obtain predictions of quantities of interest with quantified uncertainties. The main applications of the StackedGP framework are to integrate different datasets through model composition, enhance predictions of quantities of interest through a cascade of intermediate predictions, and to propagate uncertainties through emulated dynamical systems driven by uncertain forcing variables. By using analytical first an...

  1. Generalized data stacking programming model with applications

    OpenAIRE

    Hala Samir Elhadidy; Rawya Yehia Rizk; Hassen Taher Dorrah

    2016-01-01

    Recent researches have shown that, everywhere in various sciences the systems are following stacked-based stored change behavior when subjected to events or varying environments “on and above” their normal situations. This paper presents a generalized data stack programming (GDSP) model which is developed to describe the system changes under varying environment. These changes which are captured with different ways such as sensor reading are stored in matrices. Extraction algorithm and identif...

  2. Representations of stack triangulations in the plane

    OpenAIRE

    Selig, Thomas

    2013-01-01

    Stack triangulations appear as natural objects when defining an increasing family of triangulations by successive additions of vertices. We consider two different probability distributions for such objects. We represent, or "draw" these random stack triangulations in the plane $\\R^2$ and study the asymptotic properties of these drawings, viewed as random compact metric spaces. We also look at the occupation measure of the vertices, and show that for these two distributions it converges to som...

  3. A Time-predictable Stack Cache

    DEFF Research Database (Denmark)

    Abbaspour, Sahar; Brandner, Florian; Schoeberl, Martin

    2013-01-01

    Real-time systems need time-predictable architectures to support static worst-case execution time (WCET) analysis. One architectural feature, the data cache, is hard to analyze when different data areas (e.g., heap allocated and stack allocated data) share the same cache. This sharing leads to le...... of a cache for stack allocated data. Our port of the LLVM C++ compiler supports the management of the stack cache. The combination of stack cache instructions and the hardware implementation of the stack cache is a further step towards timepredictable architectures.......Real-time systems need time-predictable architectures to support static worst-case execution time (WCET) analysis. One architectural feature, the data cache, is hard to analyze when different data areas (e.g., heap allocated and stack allocated data) share the same cache. This sharing leads to less...... precise results of the cache analysis part of the WCET analysis. Splitting the data cache for different data areas enables composable data cache analysis. The WCET analysis tool can analyze the accesses to these different data areas independently. In this paper we present the design and implementation...

  4. Detailed Electrochemical Characterisation of Large SOFC Stacks

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Hjelm, Johan; Barfod, R.

    2012-01-01

    As solid oxide fuel cell (SOFC) technology is moving closer to a commercial break through, lifetime limiting factors, determination of the limits of safe operation and methods to measure the “state-of-health” of operating cells and stacks are becoming of increasing interest. This requires applica...... out at a range of ac perturbation amplitudes in order to investigate linearity of the response and the signal-to-noise ratio. Separation of the measured impedance into series and polarisation resistances was possible....... to analyse in detail. Today one is forced to use mathematical modelling to extract information about existing gradients and cell resistances in operating stacks, as mature techniques for local probing are not available. This type of spatially resolved information is essential for model refinement...... and validation, and helps to further the technological stack development. Further, more detailed information obtained from operating stacks is essential for developing appropriate process monitoring and control protocols for stack and system developers. An experimental stack with low ohmic resistance from Topsoe...

  5. Assessment for potential radionuclide emissions from stacks and diffuse and fugitive sources on the Hanford Site

    International Nuclear Information System (INIS)

    Davis, W.E.; Schmidt, J.W.; Gleckler, B.P.; Rhoads, K.

    1995-06-01

    By using the six EPA-approved methods, instead of only the original back calculation method for assessing the 84 WHC registered stacks, the number of stacks requiring continuous monitoring was reduced from 32 to 19 stacks. The intercomparison between results showed that no correlation existed between back calculations and release fractions. Also the NDA, upstream air samples, and powder release fraction method results were at least three orders of magnitude lower then the back calculations results. The most surprising results of the assessment came from NDA. NDA was found to be an easy method for assessing potential emissions. For the nine stacks assessed by NDA, all nine of the stacks would have required continuous monitoring when assessed by back calculations. However, when NDA was applied all stacks had potential emissions that would cause an EDE below the > 0.1 mrem/y standard. Apparent DFs for the HEPA filter systems were calculated for eight nondesignated stacks with emissions above the detection limit. These apparent DFs ranged from 0.5 to 250. The EDE dose to the MEI was calculated to be 0.028 mrem/y for diffuse and fugitive emissions from the Hanford Sited. This is well below the > 0.1 mrem/y standard

  6. From Multi to Single Stack Automata

    Science.gov (United States)

    Atig, Mohamed Faouzi

    We investigate the issue of reducing the verification problem of multi-stack machines to the one for single-stack machines. For instance, elegant (and practically efficient) algorithms for bounded-context switch analysis of multi-pushdown systems have been recently defined based on reductions to the reachability problem of (single-stack) pushdown systems [10,18]. In this paper, we extend this view to both bounded-phase visibly pushdown automata (BVMPA) [16] and ordered multi-pushdown automata (OMPA) [1] by showing that each of their emptiness problem can be reduced to the one for a class of single-stack machines. For these reductions, we introduce effective generalized pushdown automata (EGPA) where operations on stacks are (1) pop the top symbol of the stack, and (2) push a word in some (effectively) given set of words L over the stack alphabet, assuming that L is in some class of languages for which checking whether L intersects regular languages is decidable. We show that the automata-based saturation procedure for computing the set of predecessors in standard pushdown automata can be extended to prove that for EGPA too the set of all predecessors of a regular set of configurations is an effectively constructible regular set. Our reductions from OMPA and BVMPA to EGPA, together with the reachability analysis procedure for EGPA, allow to provide conceptually simple algorithms for checking the emptiness problem for each of these models, and to significantly simplify the proofs for their 2ETIME upper bounds (matching their lower-bounds).

  7. Start-Stop Test Procedures on the PEMFC Stack Level

    DEFF Research Database (Denmark)

    Mitzel, Jens; Nygaard, Frederik; Veltzé, Sune

    The test is addressed to investigate the influence on stack durability of a long stop followed by a restart of a stack. Long stop should be defined as a stop in which the anodic compartment is fully filled by air due to stack leakages. In systems, leakage level of the stack is low and time to fil...

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

    Energy Technology Data Exchange (ETDEWEB)

    Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    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 Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities.

  9. Data Quality Objectives Summary Report for the Demolition of the 116-D and 116-DR Stacks

    International Nuclear Information System (INIS)

    Adler, J. G.

    1999-01-01

    This data quality objective (DQO) summary report has been developed to support demolition and disposal of the 116-D and 116-DR stacks in the 100-D Area of the Hanford Site. This project-specific summary was developed to meet the requirements in BHI-EE-01, Environmental Investigations Procedures, Procedure 1.2, ''Data Quality Objectives,'' using a simplified DQO process. The pathway for disposal of the 116-D and 116-DR stacks is the Environmental Restoration Disposal Facility (ERDF), which requires the development of a waste profile. A combination of process knowledge, history, and existing analogous data will be used to build a waste profile to dispose of the stack and plenum debris in the ERDF. Additional sample data are not necessary for waste designation. This report also addresses the Resources, Conservation, and Recovery Act of 1976 treatment, storage, and disposal closure requirements associated with the 116-DR stack

  10. EmuStack: An OpenStack-Based DTN Network Emulation Platform (Extended Version

    Directory of Open Access Journals (Sweden)

    Haifeng Li

    2016-01-01

    Full Text Available With the advancement of computing and network virtualization technology, the networking research community shows great interest in network emulation. Compared with network simulation, network emulation can provide more relevant and comprehensive details. In this paper, EmuStack, a large-scale real-time emulation platform for Delay Tolerant Network (DTN, is proposed. EmuStack aims at empowering network emulation to become as simple as network simulation. Based on OpenStack, distributed synchronous emulation modules are developed to enable EmuStack to implement synchronous and dynamic, precise, and real-time network emulation. Meanwhile, the lightweight approach of using Docker container technology and network namespaces allows EmuStack to support a (up to hundreds of nodes large-scale topology with only several physical nodes. In addition, EmuStack integrates the Linux Traffic Control (TC tools with OpenStack for managing and emulating the virtual link characteristics which include variable bandwidth, delay, loss, jitter, reordering, and duplication. Finally, experiences with our initial implementation suggest the ability to run and debug experimental network protocol in real time. EmuStack environment would bring qualitative change in network research works.

  11. A polymer electrolyte fuel cell stack for stationary power generation from hydrogen fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gottesfeld, S. [Los Alamos National Lab., NM (United States)

    1995-09-01

    The fuel cell is the most efficient device for the conversion of hydrogen fuel to electric power. As such, the fuel cell represents a key element in efforts to demonstrate and implement hydrogen fuel utilization for electric power generation. The low temperature, polymer electrolyte membrane fuel cell (PEMFC) has recently been identified as an attractive option for stationary power generation, based on the relatively simple and benign materials employed, the zero-emission character of the device, and the expected high power density, high reliability and low cost. However, a PEMFC stack fueled by hydrogen with the combined properties of low cost, high performance and high reliability has not yet been demonstrated. Demonstration of such a stack will remove a significant barrier to implementation of this advanced technology for electric power generation from hydrogen. Work done in the past at LANL on the development of components and materials, particularly on advanced membrane/electrode assemblies (MEAs), has contributed significantly to the capability to demonstrate in the foreseeable future a PEMFC stack with the combined characteristics described above. A joint effort between LANL and an industrial stack manufacturer will result in the demonstration of such a fuel cell stack for stationary power generation. The stack could operate on hydrogen fuel derived from either natural gas or from renewable sources. The technical plan includes collaboration with a stack manufacturer (CRADA). It stresses the special requirements from a PEMFC in stationary power generation, particularly maximization of the energy conversion efficiency, extension of useful life to the 10 hours time scale and tolerance to impurities from the reforming of natural gas.

  12. Development of internal manifold heat exchanger (IMHEX reg sign ) molten carbonate fuel cell stacks

    Energy Technology Data Exchange (ETDEWEB)

    Marianowski, L.G.; Ong, E.T.; Petri, R.J.; Remick, R.J.

    1991-01-01

    The Institute of Gas Technology (IGT) has been in the forefront of molten carbonate fuel cell (MCFC) development for over 25 years. Numerous cell designs have been tested and extensive tests have been performed on a variety of gas manifolding alternatives for cells and stacks. Based upon the results of these performance tests, IGT's development efforts started focusing on an internal gas manifolding concept. This work, initiated in 1988, is known today as the IMHEX{reg sign} concept. MCP has developed a comprehensive commercialization program loading to the sale of commercial units in 1996. MCP's role is in the manufacture of stack components, stack assembly, MCFC subsystem testing, and the design, marketing and construction of MCFC power plants. Numerous subscale (1 ft{sup 2}) stacks have been operated containing between 3 and 70 cells. These tests verified and demonstrated the viability of internal manifolding from technical (no carbonate pumping), engineering (relaxed part dimensional tolerance requirements), and operational (good gas sealing) aspects. Simplified fabrication, ease of assembly, the elimination of external manifolds and all associated clamping requirements has significantly lowered anticipated stack costs. Ongoing 1 ft{sup 2} stack testing is generating performance and endurance characteristics as a function of system specified operating conditions. Commercial-sized, full-area stacks (10 ft{sup 2}) are in the process of being assembled and will be tested in November. This paper will review the recent developments the MCFC scale-up and manufacture work of MCP, and the research and development efforts of IGT which support those efforts. 17 figs.

  13. Forced Air-Breathing PEMFC Stacks

    Directory of Open Access Journals (Sweden)

    K. S. Dhathathreyan

    2012-01-01

    Full Text Available Air-breathing fuel cells have a great potential as power sources for various electronic devices. They differ from conventional fuel cells in which the cells take up oxygen from ambient air by active or passive methods. The air flow occurs through the channels due to concentration and temperature gradient between the cell and the ambient conditions. However developing a stack is very difficult as the individual cell performance may not be uniform. In order to make such a system more realistic, an open-cathode forced air-breathing stacks were developed by making appropriate channel dimensions for the air flow for uniform performance in a stack. At CFCT-ARCI (Centre for Fuel Cell Technology-ARC International we have developed forced air-breathing fuel cell stacks with varying capacity ranging from 50 watts to 1500 watts. The performance of the stack was analysed based on the air flow, humidity, stability, and so forth, The major advantage of the system is the reduced number of bipolar plates and thereby reduction in volume and weight. However, the thermal management is a challenge due to the non-availability of sufficient air flow to remove the heat from the system during continuous operation. These results will be discussed in this paper.

  14. Enhanced dynamical stability with harmonic slip stacking

    Directory of Open Access Journals (Sweden)

    Jeffrey Eldred

    2016-10-01

    Full Text Available We develop a configuration of radio-frequency (rf cavities to dramatically improve the performance of slip stacking. Slip stacking is an accumulation technique used at Fermilab to nearly double proton intensity by maintaining two beams of different momenta in the same storage ring. The two particle beams are longitudinally focused in the Recycler by two 53 MHz 100 kV rf cavities with a small frequency difference between them. We propose an additional 106 MHz 20 kV rf cavity with a frequency at the double the average of the upper and lower main rf frequencies. We show the harmonic rf cavity cancels out the resonances generated between the two main rf cavities and we derive the relationship between the harmonic rf voltage and the main rf voltage. We find the area factors that can be used to calculate the available phase space area for any set of beam parameters without individual simulation. We establish Booster beam quality requirements to achieve 99% slip stacking efficiency. We measure the longitudinal distribution of the Booster beam and use it to generate a realistic beam model for slip stacking simulation. We demonstrate that the harmonic rf cavity can not only reduce particle loss during slip stacking, but also reduce the final longitudinal emittance.

  15. Design Handbook for a Stack Foundation

    OpenAIRE

    Tuominen, Vilma

    2011-01-01

    This thesis was made for Citec Engineering Oy Ab as a handbook and as a design tool for concrete structure designers. Handbook is about the Wärtsilä Power Plant stack structure, which is a base for about 40 meters high stack pipe. The purpose is to make a calculation base to support the design work, which helps the designer to check the right dimensions of the structure. Thesis is about to be for the concrete designers and also other designers and authorities. As an example I have used an...

  16. Simple model of stacking-fault energies

    DEFF Research Database (Denmark)

    Stokbro, Kurt; Jacobsen, Lærke Wedel

    1993-01-01

    A simple model for the energetics of stacking faults in fcc metals is constructed. The model contains third-nearest-neighbor pairwise interactions and a term involving the fourth moment of the electronic density of states. The model is in excellent agreement with recently published local-density ......A simple model for the energetics of stacking faults in fcc metals is constructed. The model contains third-nearest-neighbor pairwise interactions and a term involving the fourth moment of the electronic density of states. The model is in excellent agreement with recently published local...

  17. Prototype particulate stack sampler with single-cut nozzle and microcomputer calculating/display system

    International Nuclear Information System (INIS)

    Eler, J.C.; Littlefield, L.G.; Tillery, M.I.

    1979-01-01

    A prototype particulate stack sampler (PPSS) has been developed to improve on the existing EPA Method 5 sampling apparatus. Its primary features are (1) higher sampling rate (56 1/min); (2) display (on demand) of all required variables and calculated values by a microcomputer-based calculating and display system; (3) continuous stack gas moisture determination; (4) a virtual impactor nozzle with 3 μm mass median diameter cutpoint which collects fine and coarse particle fractions on separate glass fiber filters; (5) a variable-area inlet to maintain isokinetic sampling conditions; and (6) conversion to stainless steel components from the glass specified by EPA Method 5. The basic sampling techniques of EPA Method 5 have been retained; however, versatility in the form of optional in-stack filters and general modernization of the stack sampler have been provided in the prototype design. Laboratory testing with monodisperse dye aerosols has shown the present variable inlet, virtual impactor nozzle to have a collection efficiency which is less than 77% and significant wall losses. This is primarily due to lack of symmetry in this rectangular jet impactor and short transition lengths dictated by physical design constraints (required passage of the nozzle through a 7.6 cm (3 in) diameter stack port). Electronic components have shown acceptable service in laboratory testing although no field testing of the prototype under a broad range of temperature, humidity, and SO 2 concentration has been undertaken

  18. 200 Area stack contamination. Interim report, August 2, 1948--October 11, 1948

    Energy Technology Data Exchange (ETDEWEB)

    Lapple, C.E.

    1948-10-11

    In connection with the problem of eliminating contamination of the atmosphere by the exhaust from the 221 Building ventilation air stacks, sand filters were previously recommended. Construction of a sand filter in West Area is about completed and construction of a filter in East Area is well underway. This report summarizes the status, technical findings, and comments and suggestions since the writer`s last Interim Report, dated August 6, 1948, was issued.

  19. Dose assessment from potential radionuclide emissions from stacks on the Hanford Site

    International Nuclear Information System (INIS)

    Davis, W.E.; Barnett, J.M.

    1995-04-01

    On February 3, 1993, the US Department of Energy, Richland Operations Office (RL), received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency (EPA), Region 10. The Compliance Order required RL to (1) evaluate all radionuclide emission points at the Hanford Site to determine which points are subject to the continuous emission sampling requirements of Title 40, Code of Federal Regulations, Part 61 (40 CFR 61), Subpart H, and (2) continuously sample radionuclide emissions in accordance with requirements in 40 CFR 61.93. The Information Request required RL to provide a written Compliance Plan to meet the requirements of the Compliance Order. A Compliance Plan was submitted to EPA, Region 10, on April 30, 1993. The Compliance Plan specified that a dose assessment would be performed for 84 Westinghouse Hanford Company (WHC) stacks registered with the Washington State Department of Health on the Hanford Site. Any stack identified in the assessment as having potential emissions to cause an effective dose equivalent (EDE) to a maximum exposed individual (MEI) greater than 0.1 mrem y -1 must have a compliant sampling system. In addition, a Federal Facility Compliance Agreement (FFCA) was signed on. February 7, 1994. The FFCA required that all unregistered stacks on the Hanford Site be assessed. This requirement increased the number of stacks to be assessed to 123 stacks. Six methods for performing the assessments are described. An initial assessment using only the HEPA filtration factor for back calculations identified 32 stacks that would have emissions which would cause an EDE to the MEI greater than 0.1 mrem y -1 . When the other methods were applied the number was reduced to 20 stacks. The paper discusses reasons for these overestimates

  20. Testing of Electrodes, Cells and Short Stacks

    DEFF Research Database (Denmark)

    Hauch, Anne; Mogensen, Mogens Bjerg

    2017-01-01

    The present contribution describes the electrochemical testing and characterization of electrodes, cells, and short stacks. To achieve the maximum insight and results from testing of electrodes and cells, it is obviously necessary to have a good understanding of the fundamental principles...

  1. Stack Gas Scrubber Makes the Grade

    Science.gov (United States)

    Chemical and Engineering News, 1975

    1975-01-01

    Describes a year long test of successful sulfur dioxide removal from stack gas with a calcium oxide slurry. Sludge disposal problems are discussed. Cost is estimated at 0.6 mill per kwh not including sludge removal. A flow diagram and equations are included. (GH)

  2. OpenStack Object Storage (Swift) essentials

    CERN Document Server

    Kapadia, Amar; Varma, Sreedhar

    2015-01-01

    If you are an IT administrator and you want to enter the world of cloud storage using OpenStack Swift, then this book is ideal for you. Basic knowledge of Linux and server technology is beneficial to get the most out of the book.

  3. Stacked spheres and lower bound theorem

    Indian Academy of Sciences (India)

    BASUDEB DATTA

    2011-11-20

    Nov 20, 2011 ... Preliminaries. Lower bound theorem. On going work. Definitions. An n-simplex is a convex hull of n + 1 affinely independent points. (called vertices) in some Euclidean space R. N . Stacked spheres and lower bound theorem. Basudeb Datta. Indian Institute of Science. 2 / 27 ...

  4. The data type variety of stack algebras

    NARCIS (Netherlands)

    Bergstra, J.A.; Tucker, J.V.

    1995-01-01

    We define and study the class of all stack algebras as the class of all minimal algebras in a variety defined by an infinite recursively enumerable set of equations. Among a number of results, we show that the initial model of the variety is computable, that its equational theory is decidable,

  5. Photoswitchable Intramolecular H-Stacking of Perylenebisimide

    NARCIS (Netherlands)

    Wang, Jiaobing; Kulago, Artem; Browne, Wesley R.; Feringa, Ben L.

    2010-01-01

    Dynamic control over the formation of H- or J-type aggregates of chromophores is of fundamental importance for developing responsive organic optoelectronic materials. In this study, the first example of photoswitching between a nonstacked and an intramolecularly H-stacked arrangement of

  6. Annex I.G. Demolition of the G1 stack at Marcoule by toppling

    International Nuclear Information System (INIS)

    2005-01-01

    The G1 stack at Marcoule was constructed during the first half of 1956 as a ventilation outlet for the G1 reactor, which is cooled by air. After the G1 reactor was decommissioned, the G1 stack served as a ventilation outlet for two new nuclear facilities on the site. Being no longer in compliance with regulations and having many inadequacies and uncertainties in terms of the prestressed concrete, the stack posed a potential damage risk in extreme wind or in the event of an earthquake. In 1994 it was decided that a new stack would be built to act as an outlet for the existing nuclear facilities, and that the old one would be demolished. The G1 stack was 100 m in height, 10 m in diameter and constructed with 24 vertically stacked concrete rings consisting of nine prefabricated sections, each 3.6 m in height. It was capped by a metal deflector (about 6 m in height and weighing 50 t). The inside consisted of nine semicircular tubes constructed of steel sheet metal weighing 120 t. The base of the stack consisted of the foundation, a plate and a base plate which were constructed at the site. The barrel sections were prefabricated. Construction lasted from January 1956 to June 1956. At the base, the cylindrical portion of the stack widened to form three feet extending to a depth of 7.5 m. The base plate of the stack was formed onsite to the height of 16.7 m and then prestressed using cables. A repair carried out in 1964 included adding a concrete lining of the initial rings of the cylinder up to a level of 22.1 m. Additional prestressing with the base plate and repair of the horizontal and vertical prestressing of the barrel were also carried out, leaving only 22 rings and 43 visible cables. The total mass of the stack was 2170 t, including: - Concrete: cylinder 800 t, base plate 1200 t; - Steel: internal structures 120 t, deflector 50 t. The main radiological risk was the presence of traces of tritium. The radioactive inventory for the entire stack was estimated in 2000

  7. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Stoessel, Chris

    2013-11-13

    This project developed a new high-performance R-10/high SHGC window design, reviewed market positioning and evaluated manufacturing solutions required for broad market adoption. The project objectives were accomplished by: identifying viable technical solutions based on modeling of modern and potential coating stacks and IGU designs; development of new coating material sets for HM thin film stacks, as well as improved HM IGU designs to accept multiple layers of HM films; matching promising new coating designs with new HM IGU designs to demonstrate performance gains; and, in cooperation with a window manufacturer, assess the potential for high-volume manufacturing and cost efficiency of a HM-based R-10 window with improved solar heat gain characteristics. A broad view of available materials and design options was applied to achieve the desired improvements. Gated engineering methodologies were employed to guide the development process from concept generation to a window demonstration. The project determined that a slightly de-rated window performance allows formulation of a path to achieve the desired cost reductions to support end consumer adoption.

  8. Project W-420 Stack Monitoring system upgrades conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    TUCK, J.A.

    1998-11-06

    This document describes the scope, justification, conceptual design, and performance of Project W-420 stack monitoring system upgrades on six NESHAP-designated, Hanford Tank Farms ventilation exhaust stacks.

  9. Heuristic Solution Approaches to the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann

    This paper introduces the Double Travelling Salesman Problem with Multiple Stacks and presents a three different metaheuristic approaches to its solution. The Double Travelling Salesman Problem with Multiple Stacks is concerned with finding the shortest route performing pickups and deliveries...

  10. Heuristic Solution Approaches to the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann

    2006-01-01

    This paper introduces the Double Travelling Salesman Problem with Multiple Stacks and presents a three different metaheuristic approaches to its solution. The Double Travelling Salesman Problem with Multiple Stacks is concerned with finding the shortest route performing pickups and deliveries...

  11. DEVS Models of Palletized Ground Stacking in Storeyed Grain Warehouse

    Directory of Open Access Journals (Sweden)

    Hou Shu-Yi

    2016-01-01

    Full Text Available Processed grain stored in storeyed warehouse is generally stacked on the ground without pallets. However, in order to improve the storing way, we developed a new stacking method, palletized ground stacking. Simulation should be used to present this new storing way. DEVS provides a formalized way to describe the system model. In this paper, DEVS models of palletized ground stacking in storeyed grain warehouse are given and a simulation model is developed by AutoMod.

  12. Sport stacking motor intervention programme for children with ...

    African Journals Online (AJOL)

    The purpose of this study was to explore sport stacking as an alternative intervention approach with typically developing children and in addition to improve DCD. Sport stacking consists of participants stacking and unstacking 12 specially designed plastic cups in predetermined sequences in as little time as possible.

  13. Notes on G-theory of Deligne-Mumford stacks

    OpenAIRE

    Toen, B.

    1999-01-01

    Based on the methods used by the author to prove the Riemann-Roch formula for algebraic stacks, this paper contains a description of the rationnal G-theory of Deligne-Mumford stacks over general bases. We will use these results to study equivariant K-theory, and also to define new filtrations on K-theory of algebraic stacks.

  14. Stacked, filtered multi-channel X-ray diode array

    Energy Technology Data Exchange (ETDEWEB)

    MacNeil, Lawrence [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Dutra, Eric [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Raphaelian, Mark [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Compton, Steve [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jacoby, Barry [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-08-01

    There are many types of X-ray diodes used for X-ray flux or spectroscopic measurements and for estimating the spectral shape of the VUV to soft X-ray spectrum. However, a need exists for a low-cost, robust X-ray diode to use for experiments in hostile environments on multiple platforms, and for experiments that utilize forces that may destroy the diode(s). Since the typical proposed use required a small size with a minimal single line-of-sight, a parallel array could not be used. So, a stacked, filtered multi-channel X-ray diode array was developed, called the MiniXRD. To achieve significant cost savings while maintaining robustness and ease of field setup, repair, and replacement, we designed the system to be modular. The filters were manufactured in-house and cover the range from 450 eV to 5000 eV. To achieve the line-of-sight accuracy needed, we developed mounts and laser alignment techniques. We modeled and tested elements of the diode design at NSTec Livermore Operations (NSTec / LO) to determine temporal response and dynamic range, leading to diode shape and circuitry changes to optimize impedance and charge storage. The authors fielded individual and stacked systems at several national facilities as ancillary "ride-along" diagnostics to test and improve the design usability. This paper presents the MiniXRD system performance, which supports consideration as a viable low-costalternative for multiple-channel low-energy X-ray measurements. This diode array is currently at Technical Readiness Level (TRL) 6.

  15. Industrial stacks design; Diseno de chimeneas industriales

    Energy Technology Data Exchange (ETDEWEB)

    Cacheux, Luis [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1986-12-31

    The Instituto de Investigaciones Electricas (IIE) though its Civil Works Department, develops, under contract with CFE`s Gerencia de Proyectos Termoelectricos (Management of Fossil Power Plant Projects), a series of methods for the design of stacks, which pretends to solve the a present day problem: the stack design of the fossil power plants that will go into operation during the next coming years in the country. [Espanol] El Instituto de Investigaciones Electricas (IIE), a traves del Departamento de Ingenieria Civil, desarrolla, bajo contrato con la Gerencia de Proyectos Termoelectricos, de la Comision Federal de Electricidad (CFE), un conjunto de metodos para el diseno de chimeneas, con el que se pretende resolver un problema inmediato: el diseno de las chimeneas de las centrales termoelectricas que entraran en operacion durante los proximos anos, en el pais.

  16. Annular feed air breathing fuel cell stack

    Science.gov (United States)

    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.

  17. System for inspection of stacked cargo containers

    Science.gov (United States)

    Derenzo, Stephen [Pinole, CA

    2011-08-16

    The present invention relates to a system for inspection of stacked cargo containers. One embodiment of the invention generally comprises a plurality of stacked cargo containers arranged in rows or tiers, each container having a top, a bottom a first side, a second side, a front end, and a back end; a plurality of spacers arranged in rows or tiers; one or more mobile inspection devices for inspecting the cargo containers, wherein the one or more inspection devices are removeably disposed within the spacers, the inspection means configured to move through the spacers to detect radiation within the containers. The invented system can also be configured to inspect the cargo containers for a variety of other potentially hazardous materials including but not limited to explosive and chemical threats.

  18. Multistage Force Amplification of Piezoelectric Stacks

    Science.gov (United States)

    Xu, Tian-Bing (Inventor); Siochi, Emilie J. (Inventor); Zuo, Lei (Inventor); Jiang, Xiaoning (Inventor); Kang, Jin Ho (Inventor)

    2015-01-01

    Embodiments of the disclosure include an apparatus and methods for using a piezoelectric device, that includes an outer flextensional casing, a first cell and a last cell serially coupled to each other and coupled to the outer flextensional casing such that each cell having a flextensional cell structure and each cell receives an input force and provides an output force that is amplified based on the input force. The apparatus further includes a piezoelectric stack coupled to each cell such that the piezoelectric stack of each cell provides piezoelectric energy based on the output force for each cell. Further, the last cell receives an input force that is the output force from the first cell and the last cell provides an output apparatus force In addition, the piezoelectric energy harvested is based on the output apparatus force. Moreover, the apparatus provides displacement based on the output apparatus force.

  19. Radiation-Tolerant Intelligent Memory Stack - RTIMS

    Science.gov (United States)

    Ng, Tak-kwong; Herath, Jeffrey A.

    2011-01-01

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

  20. Absorption spectra of AA-stacked graphite

    International Nuclear Information System (INIS)

    Chiu, C W; Lee, S H; Chen, S C; Lin, M F; Shyu, F L

    2010-01-01

    AA-stacked graphite shows strong anisotropy in geometric structures and velocity matrix elements. However, the absorption spectra are isotropic for the polarization vector on the graphene plane. The spectra exhibit one prominent plateau at middle energy and one shoulder structure at lower energy. These structures directly reflect the unique geometric and band structures and provide sufficient information for experimental fitting of the intralayer and interlayer atomic interactions. On the other hand, monolayer graphene shows a sharp absorption peak but no shoulder structure; AA-stacked bilayer graphene has two absorption peaks at middle energy and abruptly vanishes at lower energy. Furthermore, the isotropic features are expected to exist in other graphene-related systems. The calculated results and the predicted atomic interactions could be verified by optical measurements.

  1. Development of on-site PAFC stacks

    Energy Technology Data Exchange (ETDEWEB)

    Hotta, K.; Matsumoto, Y. [Kansai Electric Power Co., Amagasaki (Japan); Horiuchi, H.; Ohtani, T. [Mitsubishi Electric Corp., Kobe (Japan)

    1996-12-31

    PAFC (Phosphoric Acid Fuel Cell) has been researched for commercial use and demonstration plants have been installed in various sites. However, PAFC don`t have a enough stability yet, so more research and development must be required in the future. Especially, cell stack needs a proper state of three phases (liquid, gas and solid) interface. It is very difficult technology to keep this condition for a long time. In the small size cell with the electrode area of 100 cm{sup 2}, gas flow and temperature distributions show uniformity. But in the large size cell with the electrode area of 4000 cm{sup 2}, the temperature distributions show non-uniformity. These distributions would cause to be shorten the cell life. Because these distributions make hot-spot and gas poverty in limited parts. So we inserted thermocouples in short-stack for measuring three-dimensional temperature distributions and observed effects of current density and gas utilization on temperature.

  2. Stacked Switched Capacitor Energy Buffer Architecture

    OpenAIRE

    Chen, Minjie; Perreault, David J.; Afridi, Khurram

    2012-01-01

    Electrolytic capacitors are often used for energy buffering applications, including buffering between single-phase ac and dc. While these capacitors have high energy density compared to film and ceramic capacitors, their life is limited. This paper presents a stacked switched capacitor (SSC) energy buffer architecture and some of its topological embodiments, which when used with longer life film capacitors overcome this limitation while achieving effective energy densities comparable to elect...

  3. Modeling the Air Flow in the 3410 Building Filtered Exhaust Stack System

    Energy Technology Data Exchange (ETDEWEB)

    Recknagle, Kurtis P.; Barnett, J. Matthew; Suffield, Sarah R.

    2013-01-23

    Additional ventilation capacity has been designed for the 3410 Building filtered exhaust stack system. The updated system will increase the number of fans from two to three and will include ductwork to incorporate the new fan into the existing stack. Stack operations will involve running various two-fan combinations at any given time. The air monitoring system of the existing two-fan stack was previously found to be in compliance with the ANSI/HPS N13.1-1999 standard, however it is not known if the modified (three-fan) system will comply. Subsequently, a full-scale three-dimensional (3-D) computational fluid dynamics (CFD) model of the modified stack system has been created to examine the sampling location for compliance with the standard. The CFD modeling results show good agreement with testing data collected from the existing 3410 Building stack and suggest that velocity uniformity and flow angles will remain well within acceptance criteria when the third fan and associated ductwork is installed. This includes two-fan flow rates up to 31,840 cfm for any of the two-fan combinations. For simulation cases in which tracer gas and particles are introduced in the main duct, the model predicts that both particle and tracer gas coefficients of variance (COVs) may be larger than the acceptable 20 percent criterion of the ANSI/HPS N13.1-1999 standard for each of the two-fan, 31,840 cfm combinations. Simulations in which the tracers are introduced near the fans result in improved, though marginally acceptable, COV values for the tracers. Due to the remaining uncertainty that the stack will qualify with the addition of the third fan and high flow rates, a stationary air blender from Blender Products, Inc. is considered for inclusion in the stack system. A model of the air blender has been developed and incorporated into the CFD model. Simulation results from the CFD model that includes the air blender show striking improvements in tracer gas mixing and tracer particle

  4. When is stacking confusing? The impact of confusion on stacking in deep H I galaxy surveys

    Science.gov (United States)

    Jones, Michael G.; Haynes, Martha P.; Giovanelli, Riccardo; Papastergis, Emmanouil

    2016-01-01

    We present an analytic model to predict the H I mass contributed by confused sources to a stacked spectrum in a generic H I survey. Based on the ALFALFA (Arecibo Legacy Fast ALFA) correlation function, this model is in agreement with the estimates of confusion present in stacked Parkes telescope data, and was used to predict how confusion will limit stacking in the deepest Square Kilometre Array precursor H I surveys. Stacking with LADUMA (Looking At the Distant Universe with MeerKAT) and DINGO UDEEP (Deep Investigation of Neutral Gas Origins - Ultra Deep) data will only be mildly impacted by confusion if their target synthesized beam size of 10 arcsec can be achieved. Any beam size significantly above this will result in stacks that contain a mass in confused sources that is comparable to (or greater than) that which is detectable via stacking, at all redshifts. CHILES (COSMOS H I Large Extragalactic Survey) 5 arcsec resolution is more than adequate to prevent confusion influencing stacking of its data, throughout its bandpass range. FAST (Five hundred metre Aperture Spherical Telescope) will be the most impeded by confusion, with H I surveys likely becoming heavily confused much beyond z = 0.1. The largest uncertainties in our model are the redshift evolution of the H I density of the Universe and the H I correlation function. However, we argue that the two idealized cases we adopt should bracket the true evolution, and the qualitative conclusions are unchanged regardless of the model choice. The profile shape of the signal due to confusion (in the absence of any detection) was also modelled, revealing that it can take the form of a double Gaussian with a narrow and wide component.

  5. Thyristor stack for pulsed inductive plasma generation.

    Science.gov (United States)

    Teske, C; Jacoby, J; Schweizer, W; Wiechula, J

    2009-03-01

    A thyristor stack for pulsed inductive plasma generation has been developed and tested. The stack design includes a free wheeling diode assembly for current reversal. Triggering of the device is achieved by a high side biased, self supplied gate driver unit using gating energy derived from a local snubber network. The structure guarantees a hard firing gate pulse for the required high dI/dt application. A single fiber optic command is needed to achieve a simultaneous turn on of the thyristors. The stack assembly is used for switching a series resonant circuit with a ringing frequency of 30 kHz. In the prototype pulsed power system described here an inductive discharge has been generated with a pulse duration of 120 micros and a pulse energy of 50 J. A maximum power transfer efficiency of 84% and a peak power of 480 kW inside the discharge were achieved. System tests were performed with a purely inductive load and an inductively generated plasma acting as a load through transformer action at a voltage level of 4.1 kV, a peak current of 5 kA, and a current switching rate of 1 kA/micros.

  6. Guanine base stacking in G-quadruplex nucleic acids

    Science.gov (United States)

    Lech, Christopher Jacques; Heddi, Brahim; Phan, Anh Tuân

    2013-01-01

    G-quadruplexes constitute a class of nucleic acid structures defined by stacked guanine tetrads (or G-tetrads) with guanine bases from neighboring tetrads stacking with one another within the G-tetrad core. Individual G-quadruplexes can also stack with one another at their G-tetrad interface leading to higher-order structures as observed in telomeric repeat-containing DNA and RNA. In this study, we investigate how guanine base stacking influences the stability of G-quadruplexes and their stacked higher-order structures. A structural survey of the Protein Data Bank is conducted to characterize experimentally observed guanine base stacking geometries within the core of G-quadruplexes and at the interface between stacked G-quadruplex structures. We couple this survey with a systematic computational examination of stacked G-tetrad energy landscapes using quantum mechanical computations. Energy calculations of stacked G-tetrads reveal large energy differences of up to 12 kcal/mol between experimentally observed geometries at the interface of stacked G-quadruplexes. Energy landscapes are also computed using an AMBER molecular mechanics description of stacking energy and are shown to agree quite well with quantum mechanical calculated landscapes. Molecular dynamics simulations provide a structural explanation for the experimentally observed preference of parallel G-quadruplexes to stack in a 5′–5′ manner based on different accessible tetrad stacking modes at the stacking interfaces of 5′–5′ and 3′–3′ stacked G-quadruplexes. PMID:23268444

  7. A new method for the characterisation and quantitative speciation of base metal smelter stack particulates.

    Science.gov (United States)

    Skeaff, James M; Thibault, Yves; Hardy, David J

    2011-06-01

    Base metal smelters may be a source of particulates containing metals of environmental concern released to the atmosphere. Knowledge of the quantitative chemical speciation of particulate releases from base metal smelters will be of value in smelter emission fingerprinting, site-specific risk assessments, predictions of the behaviour of smelter stack particulates released to the environment and in resolving liability issues related to current and historic releases. Accordingly, we have developed an innovative approach comprising bulk chemical analysis, a leaching procedure, X-ray diffraction analysis and scanning electron microscopy/electron probe microanalysis characterisation in a step-wise apportioning procedure to derive the quantitative speciation of particulate samples from the stacks of three copper smelters designated as A, B and C. For the A smelter stack particulates, the major calculated percentages were 29 CuSO(4), 20 ZnSO(4).H(2)O, 13 (Cu(0.94)Zn(0.06))(2)(AsO(4))(OH), 11 PbSO(4) and four As(2)O(3). For the B smelter stack particulates, the primary calculated percentages were 20 ZnSO(4).H(2)O, 20 PbSO(4), 12 CuSO(4) and nine As(2)O(3). Finally, we calculated that the C smelter stack particulates mostly comprised 34 ZnSO(4).H(2)O, 19 (Cu(0.84)Zn(0.16))(AsO(3)OH), 11 PbSO(4), 10 As(2)O(3) and nine Zn(3)(AsO(4))(2). Between 56% and 67% by weight of the smelter stack particulates, including the As, was soluble in water. For these and other operations, the data and approach may be useful in estimating metals partitioning among water, soil and sediment, as well as predictions of the effects of the stack particulates released to the environment.

  8. Introduction of a stack-phantom for PET

    International Nuclear Information System (INIS)

    Jonsson, C.; Schnell, P.O.; Jacobsson, H.; Engelin, L.; Danielsson, A.M.; Johansson, L.; Larsson, S.A.; Pagani, M.; Stone-Elander, S.

    2002-01-01

    Aim: We have previously developed a new flexible phantom system for SPECT, i.e. 'the stack phantom' (Eur. J. Nucl. Med. 27, No.2, 131-139, 2000). The unique feature of this phantom system is that it allows studies with, as well as without major degrading impacts from photon attenuation and Compton scattering. The specific aim of this work was to further develop the system with special reference to PET. Material and methods: The principle of the phantom concept is discrete sampling of 3D objects by a series of equidistant 2D planes. The 2D planes are a digitised set of 2D sections, representing the radioactivity distribution in the object of interest. Using a grey scale related to the radioactivity concentration, selected images are printed by radioactive ink on thin paper sheets and stacked into the 3D structure with low-density or with tissue equivalent material in between. Using positron emitting radionuclides, the paper sheets alone may not be sufficiently thick to avoid annihilation losses due to escaping positrons. In order to investigate the amount of additional material needed, a spot of radioactivity ( 18 F) was printed out and subsequently covered by adding thin plastic films (0.055mm) on both sides of the paper. Short PET scans (ECAT 921) were performed and the count-rate was registered after each additional layer of plastic cover. A first prototype, a cylindrical cold-spot phantom was constructed on the basis of these results. Nine identical sheets were printed out and first mounted in between 4 mm plates of polystyrene (density 1.04 g/cm 3 ). After a PET-scan, the paper sheets were re-mounted in between a low-density material (Divinycell, H30, density 0.03 g/cm 3 ) before repeating the PET scan. Results: For 18 F, the number of registered annihilation photons increased with increasing number of plastic sheets from 70% for the pure paper sheet to about 100% with 0.5 mm plastic cover on each side. PET of the low-density stacked cold spot phantom

  9. Fiscal year 1980-81 implementation plan in support of technical development and integration of sampling and aggregation procedures. [crop acreage estimation

    Science.gov (United States)

    1981-01-01

    The specific objectives of the FY 1980-81 tasks are: (1) further refinements to the weighted aggregation procedure; (2) improved approaches for estimating within-stratum variance; (3) more intensive investigation of alternative sampling strategies such as full-frame sampling strategy, and (4) further developments in regard to a simulated approach for assessing the performance of the overall designed sampling and aggregation system.

  10. To stack or not to stack: Spectral energy distribution properties of Lyα-emitting galaxies at z = 2.1

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, Carlos J.; Bish, Hannah; Gawiser, Eric; Kurczynski, Peter [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Acquaviva, Viviana [Physics Department, New York City College of Technology, City University of New York, 300 Jay Street, Brooklyn, NY 11201 (United States); Finkelstein, Steven L. [Department of Astronomy, The University of Texas at Austin, Austin, TX 78712 (United States); Ciardullo, Robin; Gronwall, Caryl; Hagen, Alex [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Ashby, Matthew L. N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Feldmeier, John [Department of Physics and Astronomy, Youngstown State University, Youngstown, OH 44555 (United States); Ferguson, Henry; Koekemoer, Anton [Space Telescope Science Institute, Baltimore, MD (United States); Guaita, Lucia [Department of Astronomy, Oskar Klein Center, Stockholm University, Roslagstullsbacken 21, Stockholm (Sweden); Newman, Jeffrey A. [Department of Physics and Astronomy, University of Pittsburgh, 3409 O' Hara St., Pittsburgh, PA 15260 (United States); Padilla, Nelson [Departmento de Astronomia y Astrofisica, Universidad Católica de Chile, Santiago (Chile)

    2014-03-01

    We use the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) GOODS-S multi-wavelength catalog to identify counterparts for 20 Lyα emitting (LAE) galaxies at z = 2.1. We build several types of stacked spectral energy distributions (SEDs) of these objects. We combine photometry to form average and median flux-stacked SEDs, and postage-stamp images to form average and median image-stacked SEDs. We also introduce scaled flux stacks that eliminate the influence of variation in overall brightness. We use the SED fitting code SpeedyMC to constrain the physical properties of individual objects and stacks. Our LAEs at z = 2.1 have stellar masses ranging from 2 × 10{sup 7} M {sub ☉} to 8 × 10{sup 9} M {sub ☉} (median = 3 × 10{sup 8} M {sub ☉}), ages ranging from 4 Myr to 500 Myr (median = 100 Myr), and E(B – V) between 0.02 and 0.24 (median = 0.12). Although still low, this represents significantly more dust reddening than has been reported for LAEs at higher redshifts. We do not observe strong correlations between Lyα equivalent width (EW) and age or E(B – V). The Lyα radiative transfer (q) factors of our sample are predominantly close to one and do not correlate strongly with EW or E(B – V). The absence of strong correlations with EW or q implies that Lyα radiative transfer is highly anisotropic and/or prevents Lyα photons from scattering in dusty regions. The SED parameters of the flux stacks match the average and median values of the individual objects, with the flux-scaled median SED performing best with uncertainties reduced by a factor of two. Median image-stacked SEDs provide a poor representation of the median individual object, and none of the stacking methods capture the large dispersion of LAE properties.

  11. Magnetization loss for stacks of ReBCO tapes

    Science.gov (United States)

    Bykovsky, N.; De Marzi, G.; Uglietti, D.; Bruzzone, P.; Muzzi, L.

    2017-02-01

    The AC loss measurements of the high temperature superconductor (HTS) cable prototype in the EDIPO test facility motivated detailed investigations of the loss contributions from the tape, strand and cable stages of the HTS fusion conductor design proposed at the Swiss Plasma Center. As an initial step of the task, magnetization tests of soldered stacks of HTS tapes were carried out at temperatures of 5 and 77 {{K}} and magnetic fields up to 12 {{T}} using the vibrating sample magnetometer technique. The influence on the magnetization loss of the number of tapes, width of the tape, field’s orientation and tape’s manufacturer is studied experimentally performing both the major and minor magnetization loops with different ramp rates of the applied magnetic field. In order to validate the test results, a numerical model is developed and presented in this work. From the numerical model we also deduced an analytical approach for the magnetization loss in the stacks of tapes with arbitrary number of tapes in the critical state model. Comparison between the measured and estimated magnetization loss of the cable prototypes is reported as well.

  12. External magnetic field and self-field effects in stacked long Josephson junctions

    DEFF Research Database (Denmark)

    Carapella, G.; Costabile, G.; Mygind, Jesper

    1996-01-01

    We have fabricated and tested samples consisting of two long stacked Josephson junctions with direct access to the intermediate electrode, whose thickness is smaller than London penetration depth lambda(L). The electrodes are patterned so that the junctions can be independently biased in the over...

  13. Experimental Evidence for Phase-Locked States in Stacked Long Josephson Junctions

    DEFF Research Database (Denmark)

    Carapella, Giovanni; Costabile, Giovanni; Mancher, Martin

    1997-01-01

    We fabricated and tested samples consisteing of two long stacked Josephson junctions with direct access to the intermediate electrode, whose thickness is smaller than the London penetration depth $\\lambda _L$. The electrodes are patterned so that the junctions can be idependently biased in the ov...

  14. Imagining Technicities

    DEFF Research Database (Denmark)

    Liboriussen, Bjarke; Plesner, Ursula

    2011-01-01

    to the elements of taste and skill. In the final analysis those references were synthesized as five imagined technicities: the architect, the engineer, the client, the Chinese, and the Virtual World native. Because technicities are often assumed and rarely discussed as actants who influence practice, their role......, this article focuses on innovative uses of virtual worlds in architecture. We interviewed architects, industrial designers and other practitioners. Conceptually supported by an understanding of technicity found in Cultural Studies, the interviews were then coded with a focus on interviewees’ references...... in cooperation and development of ICTs seems to pass unnoticed. However, since they are aligned into ICTs, technicities impact innovation....

  15. Simplified method to determine absolute ac-loss values of superconducting tapes for varying sample geometries

    International Nuclear Information System (INIS)

    Schmidt, C; Goldacker, W

    2006-01-01

    The measurement of energy dissipation in superconducting high T c tapes in an external ac-field is of major concern for their technical application at 50 Hz. The widely used technique is based on the measurement of the magnetization loop which is proportional to the dissipated energy. Since the proportionality constant depends on the geometry of the sample and of the pick-up coils used, calibration of the system is necessary. A convenient way is the calibration with a calorimetric measurement which however leads, at 77 K, to the problem of long thermal time constants. It requires furthermore a special preparation of the sample which must be thermally insulated from the cooling bath. This paper gives a simple relationship between the sample geometry and the calorimetric calibration factor, empirically deduced from measurements on tapes and stacks of tapes with rectangular cross sections. The accuracy of the method is within about ±10 %, which is sufficient for most technical applications

  16. Improved Direct Methanol Fuel Cell Stack

    Science.gov (United States)

    Wilson, Mahlon S.; Ramsey, John C.

    2005-03-08

    A stack of direct methanol fuel cells exhibiting a circular footprint. A cathode and anode manifold, tie-bolt penetrations and tie-bolts are located within the circular footprint. Each fuel cell uses two graphite-based plates. One plate includes a cathode active area that is defined by serpentine channels connecting the inlet and outlet cathode manifold. The other plate includes an anode active area defined by serpentine channels connecting the inlet and outlet of the anode manifold, where the serpentine channels of the anode are orthogonal to the serpentine channels of the cathode. Located between the two plates is the fuel cell active region.

  17. NSF tandem stack support structure deflection characteristics

    International Nuclear Information System (INIS)

    Cook, J.

    1979-12-01

    Results are reported of load tests carried out on the glass legs of the insulating stack of the 30 MV tandem Van de Graaff accelerator now under construction at Daresbury Laboratory. The tests to investigate the vulnerability of the legs when subjected to tensile stresses were designed to; establish the angle of rotation of the pads from which the stresses in the glass legs may be calculated, proof-test the structure and at the same time reveal any asymmetry in pad rotations or deflections, and to confirm the validity of the computer design analysis. (UK)

  18. Compliant Glass Seals for SOFC Stacks

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Yeong -Shyung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Choi, Jung-Pyung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Xu, Wei [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stephens, Elizabeth V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Koeppel, Brian J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stevenson, Jeffry W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lara-Curzio, Edgar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-04-30

    This report summarizes results from experimental and modeling studies performed by participants in the Solid-State Energy Conversion Alliance (SECA) Core Technology Program, which indicate that compliant glass-based seals offer a number of potential advantages over conventional seals based on de-vitrifying glasses, including reduced stresses during stack operation and thermal cycling, and the ability to heal micro-damage induced during thermal cycling. The properties and composition of glasses developed and/or investigated in these studies are reported, along with results from long-term (up to 5,800h) evaluations of seals based on a compliant glass containing ceramic particles or ceramic fibers.

  19. Effects of combustible stacking in large compartments

    DEFF Research Database (Denmark)

    Gentili, Filippo; Giuliani, Luisa; Bontempi, Franco

    2013-01-01

    This paper focuses on the modelling of fire in case of various distributions of combustible materials in a large compartment. Large compartments often represent a challenge for structural fire safety, because of lack of prescriptive rules to follow and difficulties of taking into account the effect...... to different stacking configurations of the pallets with the avail of a CFD code. The results in term of temperatures of the hot gasses and of the steel elements composing the structural system are compared with simplified analytical model of localized and post-flashover fires, with the aim of highlighting...

  20. Displacive phase transformations and generalized stacking faults

    Czech Academy of Sciences Publication Activity Database

    Paidar, Václav; Ostapovets, Andriy; Duparc, O. H.; Khalfallah, O.

    2012-01-01

    Roč. 122, č. 3 (2012), s. 490-492 ISSN 0587-4246. [International Symposium on Physics of Materials, ISPMA /12./. Praha, 04.09.2011-08.09.2011] R&D Projects: GA AV ČR IAA100100920 Institutional research plan: CEZ:AV0Z10100520 Keywords : ab-initio calculations * close-packed structures * generalized stacking faults * homogeneous deformation * lattice deformation * many-body potentials Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.531, year: 2012

  1. Technical Proposal for Loading 3000 Gallon Crude Oil Samples from Field Terminal to Sandia Pressurized Tanker to Support US DOE/DOT Crude Oil Characterization Research Study

    Energy Technology Data Exchange (ETDEWEB)

    Lord, David; Allen, Raymond

    2016-10-01

    Sandia National Laboratories is seeking access to crude oil samples for a research project evaluating crude oil combustion properties in large-scale tests at Sandia National Laboratories in Albuquerque, NM. Samples must be collected from a source location and transported to Albuquerque in a tanker that complies with all applicable regulations for transportation of crude oil over public roadways. Moreover, the samples must not gain or lose any components, to include dissolved gases, from the point of loading through the time of combustion at the Sandia testing facility. In order to achieve this, Sandia designed and is currently procuring a custom tanker that utilizes water displacement in order to achieve these performance requirements. The water displacement procedure is modeled after the GPA 2174 standard “Obtaining Liquid Hydrocarbons Samples for Analysis by Gas Chromatography” (GPA 2014) that is used routinely by crude oil analytical laboratories for capturing and testing condensates and “live” crude oils, though it is practiced at the liter scale in most applications. The Sandia testing requires 3,000 gallons of crude. As such, the water displacement method will be upscaled and implemented in a custom tanker. This report describes the loading process for acquiring a ~3,000 gallon crude oil sample from commercial process piping containing single phase liquid crude oil at nominally 50-100 psig. This document contains a general description of the process (Section 2), detailed loading procedure (Section 3) and associated oil testing protocols (Section 4).

  2. AC impedance diagnosis of a 500 W PEM fuel cell stack . Part I: Stack impedance

    Science.gov (United States)

    Yuan, Xiaozi; Sun, Jian Colin; Blanco, Mauricio; Wang, Haijiang; Zhang, Jiujun; Wilkinson, David P.

    Diagnosis of stack performance is of importance to proton exchange membrane (PEM) fuel cell research. This paper presents the diagnostic testing results of a 500 W Ballard Mark V PEM fuel cell stack with an active area of 280 cm 2 by electrochemical impedance spectroscopy (EIS). The EIS was measured using a combination of a FuelCon test station, a TDI loadbank, and a Solartron 1260 Impedance/Gain-Phase Analyzer operating in the galvanostatic mode. The method described in this work can obtain the impedance spectra of fuel cells with a larger geometric surface area and power, which are normally difficult to measure due to the limitations on commercial load banks operating at high currents. By using this method, the effects of temperature, flow rate, and humidity on the stack impedance spectra were examined. The results of the electrochemical impedance analysis show that with increasing temperature, the charge transfer resistance decreases due to the slow oxygen reduction reaction (ORR) process at low temperature. If the stack is operated at a fixed air flow rate, a low frequency arc appears and grows with increasing current due to the shortage of air. The anode humidification cut-off does not affect the spectra compared to the cut-off for cathode humidification.

  3. Improved charge trapping flash device with Al2O3/HfSiO stack as blocking layer

    International Nuclear Information System (INIS)

    Zheng Zhi-Wei; Huo Zong-Liang; Zhu Chen-Xin; Xu Zhong-Guang; Liu Jing; Liu Ming

    2011-01-01

    In this paper, we investigate an Al 2 O 3 /HfSiO stack as the blocking layer of a metal—oxide—nitride—oxide—silicon-type (MONOS) memory capacitor. Compared with a memory capacitor with a single HfSiO layer as the blocking layer or an Al 2 O 3 /HfO 2 stack as the blocking layer, the sample with the Al 2 O 3 /HfSiO stack as the blocking layer shows high program/erase (P/E) speed and good data retention characteristics. These improved performances can be explained by energy band engineering. The experimental results demonstrate that the memory device with an Al 2 O 3 /HfSiO stack as the blocking layer has great potential for further high-performance nonvolatile memory applications. (interdisciplinary physics and related areas of science and technology)

  4. Stray field interaction of stacked amorphous tapes

    International Nuclear Information System (INIS)

    Guenther, Wulf; Flohrer, Sybille

    2008-01-01

    In this study, magnetic cores made of amorphous rectangular tape layers are investigated. The quality factor Q of the tape material decreases rapidly, however, when stacking at least two tape layers. The hysteresis loop becomes non-linear, and the coercivity increases. These effects are principally independent of the frequency and occur whether tape layers are insulated or not. The Kerr-microscopy was used to monitor local hysteresis loops by varying the distance of two tape layers. The magnetization direction of each magnetic domain is influenced by the anisotropy axis, the external magnetic field and the stray field of magnetic domains of the neighboring tape layers. We found that crossed easy axes (as the extreme case for inclined axes) of congruent domains retain the remagnetization and induce a plateau of the local loop. Summarizing local loops leads to the observed increase of coercivity and non-linearity of the inductively measured loop. A high Q-factor can be preserved if the easy axes of stacked tape layers are identical within the interaction range in the order of mm

  5. Annular feed air breathing fuel cell stack

    Science.gov (United States)

    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.

  6. Stacking Analysis of Binary Systems with HAWC

    Science.gov (United States)

    Brisbois, Chad; HAWC Collaboration

    2017-01-01

    Detecting binary systems at TeV energies is an important problem because only a handful of such systems are currently known. The nature of such systems is typically thought to be composed of a compact object and a massive star. The TeV emission from these systems does not obviously correspond to emission in GeV or X-ray, where many binary systems have previously been found. This study focuses on a stacking method to detect TeV emission from LS 5039, a known TeV binary, to test its efficacy in HAWC data. Stacking is a widely employed method for increasing signal to noise ratio in optical astronomy, but has never been attempted previously with HAWC. HAWC is an ideal instrument to search for TeV binaries, because of its wide field of view and high uptime. Applying this method to the entire sky may allow HAWC to detect binary sources of very short or very long periods not sensitive to current analyses. NSF, DOE, Los Alamos, Michigan Tech, CONACyt, UNAM, BUAP.

  7. High performance zinc air fuel cell stack

    Science.gov (United States)

    Pei, Pucheng; Ma, Ze; Wang, Keliang; Wang, Xizhong; Song, Mancun; Xu, Huachi

    2014-03-01

    A zinc air fuel cell (ZAFC) stack with inexpensive manganese dioxide (MnO2) as the catalyst is designed, in which the circulation flowing potassium hydroxide (KOH) electrolyte carries the reaction product away and acts as a coolant. Experiments are carried out to investigate the characteristics of polarization, constant current discharge and dynamic response, as well as the factors affecting the performance and uniformity of individual cells in the stack. The results reveal that the peak power density can be as high as 435 mW cm-2 according to the area of the air cathode sheet, and the influence factors on cell performance and uniformity are cell locations, filled state of zinc pellets, contact resistance, flow rates of electrolyte and air. It is also shown that the time needed for voltages to reach steady state and that for current step-up or current step-down are both in milliseconds, indicating the ZAFC can be excellently applied to vehicles with rapid dynamic response demands.

  8. Generalized stacking fault energies of alloys.

    Science.gov (United States)

    Li, Wei; Lu, Song; Hu, Qing-Miao; Kwon, Se Kyun; Johansson, Börje; Vitos, Levente

    2014-07-02

    The generalized stacking fault energy (γ surface) provides fundamental physics for understanding the plastic deformation mechanisms. Using the ab initio exact muffin-tin orbitals method in combination with the coherent potential approximation, we calculate the γ surface for the disordered Cu-Al, Cu-Zn, Cu-Ga, Cu-Ni, Pd-Ag and Pd-Au alloys. Studying the effect of segregation of the solute to the stacking fault planes shows that only the local chemical composition affects the γ surface. The calculated alloying trends are discussed using the electronic band structure of the base and distorted alloys.Based on our γ surface results, we demonstrate that the previous revealed 'universal scaling law' between the intrinsic energy barriers (IEBs) is well obeyed in random solid solutions. This greatly simplifies the calculations of the twinning measure parameters or the critical twinning stress. Adopting two twinnability measure parameters derived from the IEBs, we find that in binary Cu alloys, Al, Zn and Ga increase the twinnability, while Ni decreases it. Aluminum and gallium yield similar effects on the twinnability.

  9. Technical Network

    CERN Multimedia

    2007-01-01

    In order to optimize the management of the Technical Network (TN), to ease the understanding and purpose of devices connected to the TN, and to improve security incident handling, the Technical Network Administrators and the CNIC WG have asked IT/CS to verify the "description" and "tag" fields of devices connected to the TN. Therefore, persons responsible for systems connected to the TN will receive email notifications from IT/CS asking them to add the corresponding information in the network database. Thank you very much for your cooperation. The Technical Network Administrators & the CNIC WG

  10. Technical Network

    CERN Multimedia

    2007-01-01

    In order to optimise the management of the Technical Network (TN), to facilitate understanding of the purpose of devices connected to the TN and to improve security incident handling, the Technical Network Administrators and the CNIC WG have asked IT/CS to verify the "description" and "tag" fields of devices connected to the TN. Therefore, persons responsible for systems connected to the TN will receive e-mails from IT/CS asking them to add the corresponding information in the network database at "network-cern-ch". Thank you very much for your cooperation. The Technical Network Administrators & the CNIC WG

  11. Manufacturing of cells and stacks for SOFC development, test and demonstration projects and SOFC hotbox design development

    Energy Technology Data Exchange (ETDEWEB)

    2008-09-15

    The purpose of this project is to support the continued SOFC development through manufacturing process optimization and manufacturing of SOFC cells and stacks. These cells and stacks will serve as a necessary base for the development activities and for the establishment of a number of test and demonstration activities. The manufacture will also help provide operating experience and reduce manufacturing cost. Another main focus of the manufacturing is to assure technical improvements and reliability. It is imperative to the eventual success of the technology that test and demonstration is carried out in the pre-market conditions that will exist for the next years in the three market segments targeted by TOFC (Distributed generation, micro CHP and APU incl. marine APU). Finally, the project also includes development activities focusing on the stack-system interface (hotbox design development) and on dealing with transients and start up and shut down times, which is of particular importance for APU and micro CHP applications. Three topics are addressed:1) Cell manufacture, including production development, capacity lift and manuf. of cells for test and demonstration; 2) Stack manufacture and test, including a test facility, stack manuf. and test of stacks in a system at HCV; 3) Hotbox design development, including design, prototype construction and testing. The progress of this project is documented. Major achievements are successful manufacture of adequate amounts of cells and stacks according to the application. Furthermore significant over-performance in design, construction and test of a methanol based hotbox prototype as well as publication of this. (au)

  12. Description of gasket failure in a 7 cell PEMFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Husar, Attila; Serra, Maria [Institut de Robotica i Informatica Industrial, Parc Tecnologic de Barcelona, Edifici U, C. Llorens i Artigas, 4-6, 2a Planta, 08028 Barcelona (Spain); Kunusch, Cristian [Laboratorio de Electronica Industrial Control e Instrumentacion, Facultad de Ingenieria, UNLP (Argentina)

    2007-06-10

    This article presents the data and the description of a fuel cell stack that failed due to gasket degradation. The fuel cell under study is a 7 cell stack. The unexpected change in several variables such as temperature, pressure and voltage indicated the possible failure of the stack. The stack was monitored over a 6 h period in which data was collected and consequently analyzed to conclude that the fuel cell stack failed due to a crossover leak on the anode inlet port located on the cathode side gasket of cell 2. This stack failure analysis revealed a series of indicators that could be used by a super visional controller in order to initiate a shutdown procedure. (author)

  13. Seismic (SSE) evaluation for the 291Z stack at the Hanford Site -- Addition of environmental monitoring penetrations

    International Nuclear Information System (INIS)

    Baxter, J.T.

    1994-01-01

    The purpose of this 291Z stack analysis is to determine the structural effects of chipping additional holes into the stacks concrete walls. The proposed holes are for new environmental monitoring sample probes to be installed at three different elevations. The approximate elevations proposed at this time are 50 ft, 135 ft and 175 ft. There will be four holes required at each of the elevations to support two sample probes extending across the diameter of the stack. A structural sensitivity study has been completed to assess the effect of the proposed holes on the baseline seismic qualification of the stack completed by URS/John A. Blume ampersand Associates, Engineers, San Francisco, California (URS/Blume) in August, 1988. Results of the sensitivity study indicate that the stack would still have adequate structural moment capacity if the new holes were drilled cutting the vertical strength reinforcing steel, or if existing penetrations added since original construction have inadvertently cut vertical rebars. For current and future modifications, no vertical rebar should be cut. A limited number of horizontal rebar, no more than 2, may be cut at the new hole locations without significantly influencing the stack structural shear capacity. New penetrations in the 291Z stack should not be located below elevation 47 ft., 4 in. due to rebar layout and the fact that maximum seismic structural loads occur below this elevation. No vertical rebar should be cut when chipping the new penetrations in the stack concrete wall for the environmental monitoring equipment. Wind load qualification was reviewed. Seismic loads govern over wind loads for all structural load cases; therefore no additional wind analyses are required

  14. Stack Characterization in CryoSat Level1b SAR/SARin Baseline C

    Science.gov (United States)

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

    2015-04-01

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

  15. Combining parametric, semi-parametric, and non-parametric survival models with stacked survival models.

    Science.gov (United States)

    Wey, Andrew; Connett, John; Rudser, Kyle

    2015-07-01

    For estimating conditional survival functions, non-parametric estimators can be preferred to parametric and semi-parametric estimators due to relaxed assumptions that enable robust estimation. Yet, even when misspecified, parametric and semi-parametric estimators can possess better operating characteristics in small sample sizes due to smaller variance than non-parametric estimators. Fundamentally, this is a bias-variance trade-off situation in that the sample size is not large enough to take advantage of the low bias of non-parametric estimation. Stacked survival models estimate an optimally weighted combination of models that can span parametric, semi-parametric, and non-parametric models by minimizing prediction error. An extensive simulation study demonstrates that stacked survival models consistently perform well across a wide range of scenarios by adaptively balancing the strengths and weaknesses of individual candidate survival models. In addition, stacked survival models perform as well as or better than the model selected through cross-validation. Finally, stacked survival models are applied to a well-known German breast cancer study. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Quadratic forms and Clifford algebras on derived stacks

    OpenAIRE

    Vezzosi, Gabriele

    2013-01-01

    In this paper we present an approach to quadratic structures in derived algebraic geometry. We define derived n-shifted quadratic complexes, over derived affine stacks and over general derived stacks, and give several examples of those. We define the associated notion of derived Clifford algebra, in all these contexts, and compare it with its classical version, when they both apply. Finally, we prove three main existence results for derived shifted quadratic forms over derived stacks, define ...

  17. Use of impedance tagging to monitor fuel cell stack performance

    Science.gov (United States)

    Silva, Gregory

    Fuel cells are electrochemical device that are traditionally assembled in stacks to perform meaningful work. Monitoring the state of the stack is vitally important to ensure that it is operating efficiently and that constituent cells are not failing for one of a several common reasons including membrane dehydration, gas diffusion layer flooding, reactant starvation, and physical damage. Current state-of-the-art monitoring systems are costly and require at least one connection per cell on the stack, which introduces reliability concerns for stacks consisting of hundreds of cells. This thesis presents a novel approach for diagnosing problems in a fuel cell stack that attempts to reduce the cost and complexity of monitoring cells in a stack. The proposed solution modifies the electrochemical impedance spectroscopy (EIS) response of each cell in the stack by connecting an electrical tag in parallel with each cell. This approach allows the EIS response of the entire stack to identify and locate problems in the stack. Capacitors were chosen as tags because they do not interfere with normal stack operation and because they can generate distinct stack EIS responses. An experiment was performed in the Center for Automation Technologies an Systems (CATS) fuel cell laboratory at Rensselaer Polytechnic Institute (RPI) to perform EIS measurements on a single cell with and without capacitor tags to investigate the proposed solution. The EIS data collected from this experiment was used to create a fuel cell model to investigate the proposed solution under ideal conditions. This thesis found that, although the concept shows some promise in simulations, significant obstacles to implementing the proposed solution. Observed EIS response when the capacitor tags were connected did not match the expected EIS response. Constraints on the capacitor tags found by the model impose significant manufacturing challenges to the proposed solution. Further development of the proposed solution is

  18. Stacked Heterogeneous Neural Networks for Time Series Forecasting

    Directory of Open Access Journals (Sweden)

    Florin Leon

    2010-01-01

    Full Text Available A hybrid model for time series forecasting is proposed. It is a stacked neural network, containing one normal multilayer perceptron with bipolar sigmoid activation functions, and the other with an exponential activation function in the output layer. As shown by the case studies, the proposed stacked hybrid neural model performs well on a variety of benchmark time series. The combination of weights of the two stack components that leads to optimal performance is also studied.

  19. A novel configuration for direct internal reforming stacks

    Science.gov (United States)

    Fellows, Richard

    This paper presents a stack concept that can be applied to both molten carbonate fuel cell (MCFC) and solid oxide fuel cell (SOFC) internal reforming stacks. It employs anode recycle and allows the design of very simple system configurations, while giving enhanced efficiencies and high specific power densities. The recycle of anode exit gas to the anode inlet has previously been proposed as a means of preventing carbon deposition in direct internal reforming (DIR) stacks. When applied to a normal stack this reduces the Nernst voltages because the recycle stream is relatively depleted in hydrogen. In the concept proposed here, known as the `Smarter' stack, there are two anode exit streams, one of which is depleted, while the other is relatively undepleted. The depleted stream passes directly to the burner, and the undepleted stream is recycled to the stack inlet. By this means high Nernst voltages are achieved in the stack. The concept has been simulated and assessed for parallel-flow and cross-flow MCFC and SOFC stacks and graphs are presented showing temperature distributions. The `Smarter' stacks employ a high recycle rate resulting in a reduced natural gas concentration at the stack inlet, and this reduces or eliminates the unfavourable temperature dip. Catalyst grading can further improve the temperature distribution. The concept allows simple system configurations in which the need for fuel pre-heat is eliminated. Efficiencies are up to 10 percentage points higher than for conventional stacks with the same cell area and maximum stack temperature. The concept presented here was devised in a project part-funded by the EU, and has been adopted by the European Advanced DIR-MCFC development programme led by BCN.

  20. Status of Slip Stacking at Fermilab Main Injector

    CERN Document Server

    Seiya, Kiyomi; Chase, Brian; Dey, Joseph; Kourbanis, Ioanis; MacLachlan, James A; Meisner, Keith G; Pasquinelli, Ralph J; Reid, John; Rivetta, Claudio H; Steimel, Jim

    2005-01-01

    In order to increase proton intensity on anti proton production cycle of the Main Injector we are going to use the technique of 'slip stacking' and doing machine studies. In slip stacking, one bunch train is injected at slightly lower energy and second train is at slightly higher energy. Afterwards they are aligned longitudinally and captured with one rf bucket. This longitudinal stacking process is expected to double the bunch intensity. The required intensity for anti proton production is 8·1012

  1. A novel design for solid oxide fuel cell stacks

    Energy Technology Data Exchange (ETDEWEB)

    Al-Qattan, A.M.; Chmielewski, D.J.; Al-Hallaj, S.; Selman, J.R. [Illinois Inst. of Technology, Chicago, IL (United States). Dept. of Chemical and Environmental Engineering

    2004-01-01

    Conventional fuel cell stack designs suffer from severe spatial nonuniformity in both temperature and current density. Such variations are known to create damaging thermal stresses within the stack and thus, impact overall lifespan. In this work, we propose a novel stack design aimed at reducing spatial variations at the source. We propose a mechanism of distributed fuel feed in which the heat generation profile can be influenced directly. Simulation results are presented to illustrate the potential of the proposed scheme. (author)

  2. Development of the electric utility dispersed use PAFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Horiuchi, Hiroshi; Kotani, Ikuo [Mitsubishi Electric Co., Kobe (Japan); Morotomi, Isamu [Kansai Electric Power Co., Hyogo (Japan)] [and others

    1996-12-31

    Kansai Electric Power Co. and Mitsubishi Electric Co. have been developing the electric utility dispersed use PAFC stack operated under the ambient pressure. The new cell design have been developed, so that the large scale cell (1 m{sup 2} size) was adopted for the stack. To confirm the performance and the stability of the 1 m{sup 2} scale cell design, the short stack study had been performed.

  3. Design and development of an automated uranium pellet stacking system

    International Nuclear Information System (INIS)

    Reiss, B.S.; Nokleby, S.B.

    2010-01-01

    A novel design for an automated uranium pellet stacking system is presented. This system is designed as a drop-in solution to the current production line to enhance the fuel pellet stacking process. The three main goals of this system are to reduce worker exposure to radiation to as low as reasonable achievable (ALARA), improve product quality, and increase productivity. The proposed system will reduce the potential for human error. This single automated system will replace the two existing pellet stacking stations while increasing the total output, eliminating pellet stacking as a bottleneck in the fuel bundle assembly process. (author)

  4. Highly Efficient, Durable Regenerative Solid Oxide Stack, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Precision Combustion, Inc. (PCI) proposes to develop a highly efficient regenerative solid oxide stack design. Novel structural elements allow direct internal...

  5. Independent determination of the accuracy of the OSTR stack gas monitor and its operational application

    International Nuclear Information System (INIS)

    Pickett, B.D.; Johnson, A.G.

    1982-01-01

    This study was undertaken to determine the accuracy of the stack gas monitor, using techniques which were independent of the monitoring system itself. Samples of argon-41 to be used as the standards in this study were carefully produced in the thermal column of the OSTR and counted on a Ge(Li) detector which was connected to a multichannel analyzer (MCA). As the argon-41 standard in the gas sample flask decayed, the concentration of the argon-41 was compared to the output of the Ge(Li)/MCA system. This established a calibration curve for the counting system, whereby a sample with an unknown concentration of argon-41 could be counted and the subsequent count rate from the sample converted to a concentration expressed in mCi per milliliter. Gas samples were extracted from various points in the reactor exhaust system and the concentrations of argon-41 were determined by counting on the Ge(Li)/MCA system. Each sample concentration was then compared to the argon-41 concentration indicated by the stack gas monitor. The initial results indicated that, although possibly intermittent, the argon-41 concentrations displayed by the stack gas monitor were often approximately 50% of those predicted by analysis of individual samples from the exhaust system. Several possible sources for the discrepancy were checked, including the method of SGM calibration, uneven mixing of exhaust air and argon-41 in the reactor building exhaust stream, and dilution of the gas concentration in the SGM system by air leakage into the system. After considerable effort, the latter cause was found to be the culprit, due to an aging gasket around the stack monitor's moving particulate-filter-paper housing

  6. Manifold seal structure for fuel cell stack

    Science.gov (United States)

    Collins, William P.

    1988-01-01

    The seal between the sides of a fuel cell stack and the gas manifolds is improved by adding a mechanical interlock between the adhesive sealing strip and the abutting surface of the manifolds. The adhesive is a material which can flow to some extent when under compression, and the mechanical interlock is formed providing small openings in the portion of the manifold which abuts the adhesive strip. When the manifolds are pressed against the adhesive strips, the latter will flow into and through the manifold openings to form buttons or ribs which mechanically interlock with the manifolds. These buttons or ribs increase the bond between the manifolds and adhesive, which previously relied solely on the adhesive nature of the adhesive.

  7. Directive Stacked Patch Antenna for UWB Applications

    Directory of Open Access Journals (Sweden)

    Sharif I. Mitu Sheikh

    2013-01-01

    Full Text Available Directional ultrawideband (UWB antennas are popular in wireless signal-tracking and body-area networks. This paper presents a stacked microstrip antenna with an ultrawide impedance bandwidth of 114%, implemented by introducing defects on the radiating patches and the ground plane. The compact (20×34 mm antenna exhibits a directive radiation patterns for all frequencies of the 3–10.6 GHz band. The optimized reflection response and the radiation pattern are experimentally verified. The designed UWB antenna is used to maximize the received power of a software-defined radio (SDR platform. For an ultrawideband impulse radio system, this class of antennas is essential to improve the performance of the communication channels.

  8. ATLAS software stack on ARM64

    Science.gov (United States)

    Smith, Joshua Wyatt; Stewart, Graeme A.; Seuster, Rolf; Quadt, Arnulf; ATLAS Collaboration

    2017-10-01

    This paper reports on the port of the ATLAS software stack onto new prototype ARM64 servers. This included building the “external” packages that the ATLAS software relies on. Patches were needed to introduce this new architecture into the build as well as patches that correct for platform specific code that caused failures on non-x86 architectures. These patches were applied such that porting to further platforms will need no or only very little adjustments. A few additional modifications were needed to account for the different operating system, Ubuntu instead of Scientific Linux 6 / CentOS7. Selected results from the validation of the physics outputs on these ARM 64-bit servers will be shown. CPU, memory and IO intensive benchmarks using ATLAS specific environment and infrastructure have been performed, with a particular emphasis on the performance vs. energy consumption.

  9. ATLAS software stack on ARM64

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00529764; The ATLAS collaboration; Stewart, Graeme; Seuster, Rolf; Quadt, Arnulf

    2017-01-01

    This paper reports on the port of the ATLAS software stack onto new prototype ARM64 servers. This included building the “external” packages that the ATLAS software relies on. Patches were needed to introduce this new architecture into the build as well as patches that correct for platform specific code that caused failures on non-x86 architectures. These patches were applied such that porting to further platforms will need no or only very little adjustments. A few additional modifications were needed to account for the different operating system, Ubuntu instead of Scientific Linux 6 / CentOS7. Selected results from the validation of the physics outputs on these ARM 64-bit servers will be shown. CPU, memory and IO intensive benchmarks using ATLAS specific environment and infrastructure have been performed, with a particular emphasis on the performance vs. energy consumption.

  10. Technical innovation in dynamic contrast-enhanced magnetic resonance imaging of musculoskeletal tumors: an MR angiographic sequence using a sparse k-space sampling strategy.

    Science.gov (United States)

    Fayad, Laura M; Mugera, Charles; Soldatos, Theodoros; Flammang, Aaron; del Grande, Filippo

    2013-07-01

    We demonstrate the clinical use of an MR angiography sequence performed with sparse k-space sampling (MRA), as a method for dynamic contrast-enhanced (DCE)-MRI, and apply it to the assessment of sarcomas for treatment response. Three subjects with sarcomas (2 with osteosarcoma, 1 with high-grade soft tissue sarcomas) underwent MRI after neoadjuvant therapy/prior to surgery, with conventional MRI (T1-weighted, fluid-sensitive, static post-contrast T1-weighted sequences) and DCE-MRI (MRA, time resolution = 7-10 s, TR/TE 2.4/0.9 ms, FOV 40 cm(2)). Images were reviewed by two observers in consensus who recorded image quality (1 = diagnostic, no significant artifacts, 2 = diagnostic, 75 % with good response, >75 % with poor response). DCE-MRI findings were concordant with histological response (arterial enhancement with poor response, no arterial enhancement with good response). Unlike conventional DCE-MRI sequences, an MRA sequence with sparse k-space sampling is easily integrated into a routine musculoskeletal tumor MRI protocol, with high diagnostic quality. In this preliminary work, tumor enhancement characteristics by DCE-MRI were used to assess treatment response.

  11. Technical innovation in dynamic contrast-enhanced magnetic resonance imaging of musculoskeletal tumors: an MR angiographic sequence using a sparse k-space sampling strategy

    International Nuclear Information System (INIS)

    Fayad, Laura M.; Mugera, Charles; Grande, Filippo del; Soldatos, Theodoros; Flammang, Aaron

    2013-01-01

    We demonstrate the clinical use of an MR angiography sequence performed with sparse k-space sampling (MRA), as a method for dynamic contrast-enhanced (DCE)-MRI, and apply it to the assessment of sarcomas for treatment response. Three subjects with sarcomas (2 with osteosarcoma, 1 with high-grade soft tissue sarcomas) underwent MRI after neoadjuvant therapy/prior to surgery, with conventional MRI (T1-weighted, fluid-sensitive, static post-contrast T1-weighted sequences) and DCE-MRI (MRA, time resolution = 7-10 s, TR/TE 2.4/0.9 ms, FOV 40 cm 2 ). Images were reviewed by two observers in consensus who recorded image quality (1 = diagnostic, no significant artifacts, 2 = diagnostic, 75 % with good response, >75 % with poor response). DCE-MRI findings were concordant with histological response (arterial enhancement with poor response, no arterial enhancement with good response). Unlike conventional DCE-MRI sequences, an MRA sequence with sparse k-space sampling is easily integrated into a routine musculoskeletal tumor MRI protocol, with high diagnostic quality. In this preliminary work, tumor enhancement characteristics by DCE-MRI were used to assess treatment response. (orig.)

  12. Actuators Using Piezoelectric Stacks and Displacement Enhancers

    Science.gov (United States)

    Bar-Cohen, Yoseph; Sherrit, Stewart; Bao, Xiaoqi; Badescu, Mircea; Lee, Hyeong Jae; Walkenmeyer, Phillip; Lih, Shyh-Shiuh

    2015-01-01

    Actuators are used to drive all active mechanisms including machines, robots, and manipulators to name a few. The actuators are responsible for moving, manipulating, displacing, pushing and executing any action that is needed by the mechanism. There are many types and principles of actuation that are responsible for these movements ranging from electromagnetic, electroactive, thermo-mechanic, piezoelectric, electrostrictive etc. Actuators are readily available from commercial producers but there is a great need for reducing their size, increasing their efficiency and reducing their weight. Studies at JPL’s Non Destructive Evaluation and Advanced Actuators (NDEAA) Laboratory have been focused on the use of piezoelectric stacks and novel designs taking advantage of piezoelectric’s potential to provide high torque/force density actuation and high electromechanical conversion efficiency. The actuators/motors that have been developed and reviewed in this paper are operated by various horn configurations as well as the use of pre-stress flexures that make them thermally stable and increases their coupling efficiency. The use of monolithic designs that pre-stress the piezoelectric stack eliminates the use of compression stress bolt. These designs enable the embedding of developed solid-state motors/actuators in any structure with the only macroscopically moving parts are the rotor or the linear translator. Finite element modeling and design tools were used to determine the requirements and operation parameters and the results were used to simulate, design and fabricate novel actuators/motors. The developed actuators and performance will be described and discussed in this paper.

  13. PISA 2009 Technical Report

    Science.gov (United States)

    OECD Publishing (NJ1), 2012

    2012-01-01

    The "PISA 2009 Technical Report" describes the methodology underlying the PISA 2009 survey. It examines additional features related to the implementation of the project at a level of detail that allows researchers to understand and replicate its analyses. The reader will find a wealth of information on the test and sample design,…

  14. Loss of collected particles from the filter of the stack monitor, the Ringhals-1 power reactor

    International Nuclear Information System (INIS)

    Stroem, L.

    1993-01-01

    The function of the filter holder was examined in the laboratory and in the Ringhals measurement installation. It was concluded that a loss of sample could occur, if the filter has a heavy particle deposit. An approximate relation between deposits thickness and loss of sample could be determined. Particle concentration in the stack air is sometimes so high, that loss of sample can occur. The test have also revealed that the sample air stream can by-pass the filter, without proper indication of the defect. Control instrumentation is proposed

  15. Archaeological investigations at a toolstone source area and temporary camp: Sample Unit 19-25, Nevada Test Site, Nye County, Nevada. Technical report No. 77

    Energy Technology Data Exchange (ETDEWEB)

    Jones, R.C.; DuBarton, A.; Edwards, S.; Pippin, L.C.; Beck, C.M.

    1993-12-31

    Archaeological investigations were initiated at Sample Unit 19--25 to retrieve information concerning settlement and subsistence data on the aboriginal hunter and gatherers in the area. Studies included collection and mapping of 35.4 acres at site 26NY1408 and excavation and mapping of 0.02 acres at site 26NY7847. Cultural resources include two rock and brush structures and associated caches and a large lithic toolstone source area and lithic artifact scatter. Temporally diagnostic artifacts indicate periodic use throughout the last 12,000 years; however dates associated with projectile points indicate most use was in the Middle and Late Archaic. Radiocarbon dates from the rock and brush structures at site 26NY7847 indicate a construction date of A.D. 1640 and repair between A.D. 1800 and 1950 for feature 1 and between A.D. 1330 and 1390 and repair at A.D. 1410 for feature 2. The dates associated with feature 2 place its construction significantly earlier than similar structures found elsewhere on Pahute Mesa. Activity areas appear to reflect temporary use of the area for procurement of available lithic and faunal resources and the manufacture of tools.

  16. Simultaneous stack-gas scrubbing and waste water treatment

    Science.gov (United States)

    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.

  17. A Software Managed Stack Cache for Real-Time Systems

    DEFF Research Database (Denmark)

    Jordan, Alexander; Abbaspourseyedi, Sahar; Schoeberl, Martin

    2016-01-01

    In a real-time system, the use of a scratchpad memory can mitigate the difficulties related to analyzing data caches, whose behavior is inherently hard to predict. We propose to use a scratchpad memory for stack allocated data. While statically allocating stack frames for individual functions to ...

  18. Calculation of AC losses in large HTS stacks and coils

    DEFF Research Database (Denmark)

    Zermeno, Victor; Abrahamsen, Asger Bech; Mijatovic, Nenad

    2012-01-01

    In this work, we present a homogenization method to model a stack of HTS tapes under AC applied transport current or magnetic field. The idea is to find an anisotropic bulk equivalent for the stack of tapes, where the internal alternating structures of insulating, metallic, superconducting and su...

  19. Efficient Context Switching for the Stack Cache: Implementation and Analysis

    DEFF Research Database (Denmark)

    Abbaspourseyedi, Sahar; Brandner, Florian; Naji, Amine

    2015-01-01

    , the analysis of the stack cache was limited to individual tasks, ignoring aspects related to multitasking. A major drawback of the original stack cache design is that, due to its simplicity, it cannot hold the data of multiple tasks at the same time. Consequently, the entire cache content needs to be saved...

  20. An industrial FT-IR process gas analyzer for stack gas cems analysis

    Energy Technology Data Exchange (ETDEWEB)

    Welch, G.M. [American instruments, Anacortes, WA (United States); Herman, B.E. [Applied Automation/Hartmann & Braun, Bartlesville, OK (United States)

    1995-12-31

    This paper describes utilizing Fourier Transform Infrared (FT-IR) technology to meet and exceed EPA requirements to Continuously Monitor Carbon Monoxide (CO) and Sulfur Dioxide (SO){sub 2} in an oil refinery. The application consists of Continuous Emission Monitoring (CEMS) of two stacks from a Fluid Catalytic Cracking unit (FCCU). The discussion will follow the project from initial specifications, installation, start-up, certification results (RATA, 7 day drift), Cylinder Gas Audit (CGA) and the required maintenance. FT-IR is a powerful analytical tool suitable for measurement of stack component gases required to meet CEMS regulations, and allows simultaneous multi-component analysis of complex stack gas streams with a continuous sample stream flow through the measurement cell. The Michelson Interferometer in a unique {open_quotes}Wishbone{close_quotes} design and with a special alignment control enables standardized configuration of the analyzer for flue gas analysis. Normal stack gas pollutants: NO{sub x}, SO{sub 2}, and CO; as well as water soluble pollutants such as NH{sub 3} and HCI may be accurately determined and reported even in the presence of 0-31 Vol % water vapor concentrations (hot and wet). This FT-IR analyzer has been operating with EPA Certification in an oil refinery environment since September 1994.

  1. Mechanical sieve for screening mineral samples

    Science.gov (United States)

    Otto, W. P.

    1970-01-01

    Mechanical sieve consists of three horizontal screens mounted in a vertical stack. A combination of rotation and tapping produces an even flow across the screens, dislodges trapped particles, an ensures rapid segregation of the sample.

  2. Technical basis for the reduction of the maximum temperature TGA-MS analysis of oxide samples from the 3013 destructive examination program

    International Nuclear Information System (INIS)

    Scogin, J. H.

    2016-01-01

    Thermogravimetric analysis with mass spectroscopy of the evolved gas (TGA-MS) is used to quantify the moisture content of materials in the 3013 destructive examination (3013 DE) surveillance program. Salts frequently present in the 3013 DE materials volatilize in the TGA and condense in the gas lines just outside the TGA furnace. The buildup of condensate can restrict the flow of purge gas and affect both the TGA operations and the mass spectrometer calibration. Removal of the condensed salts requires frequent maintenance and subsequent calibration runs to keep the moisture measurements by mass spectroscopy within acceptable limits, creating delays in processing samples. In this report, the feasibility of determining the total moisture from TGA-MS measurements at a lower temperature is investigated. A temperature of the TGA-MS analysis which reduces the complications caused by the condensation of volatile materials is determined. Analysis shows that an excellent prediction of the presently measured total moisture value can be made using only the data generated up to 700 °C and there is a sound physical basis for this estimate. It is recommended that the maximum temperature of the TGA-MS determination of total moisture for the 3013 DE program be reduced from 1000 °C to 700 °C. It is also suggested that cumulative moisture measurements at 550 °C and 700°C be substituted for the measured value of total moisture in the 3013 DE database. Using these raw values, any of predictions of the total moisture discussed in this report can be made.

  3. Technical basis for the reduction of the maximum temperature TGA-MS analysis of oxide samples from the 3013 destructive examination program

    Energy Technology Data Exchange (ETDEWEB)

    Scogin, J. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-24

    Thermogravimetric analysis with mass spectroscopy of the evolved gas (TGA-MS) is used to quantify the moisture content of materials in the 3013 destructive examination (3013 DE) surveillance program. Salts frequently present in the 3013 DE materials volatilize in the TGA and condense in the gas lines just outside the TGA furnace. The buildup of condensate can restrict the flow of purge gas and affect both the TGA operations and the mass spectrometer calibration. Removal of the condensed salts requires frequent maintenance and subsequent calibration runs to keep the moisture measurements by mass spectroscopy within acceptable limits, creating delays in processing samples. In this report, the feasibility of determining the total moisture from TGA-MS measurements at a lower temperature is investigated. A temperature of the TGA-MS analysis which reduces the complications caused by the condensation of volatile materials is determined. Analysis shows that an excellent prediction of the presently measured total moisture value can be made using only the data generated up to 700 °C and there is a sound physical basis for this estimate. It is recommended that the maximum temperature of the TGA-MS determination of total moisture for the 3013 DE program be reduced from 1000 °C to 700 °C. It is also suggested that cumulative moisture measurements at 550 °C and 700°C be substituted for the measured value of total moisture in the 3013 DE database. Using these raw values, any of predictions of the total moisture discussed in this report can be made.

  4. The behaviour of stacking fault energy upon interstitial alloying.

    Science.gov (United States)

    Lee, Jee-Yong; Koo, Yang Mo; Lu, Song; Vitos, Levente; Kwon, Se Kyun

    2017-09-11

    Stacking fault energy is one of key parameters for understanding the mechanical properties of face-centered cubic materials. It is well known that the plastic deformation mechanism is closely related to the size of stacking fault energy. Although alloying is a conventional method to modify the physical parameter, the underlying microscopic mechanisms are not yet clearly established. Here, we propose a simple model for determining the effect of interstitial alloying on the stacking fault energy. We derive a volumetric behaviour of stacking fault energy from the harmonic approximation to the energy-lattice curve and relate it to the contents of interstitials. The stacking fault energy is found to change linearly with the interstitial content in the usual low concentration domain. This is in good agreement with previously reported experimental and theoretical data.

  5. Dynamic Model of High Temperature PEM Fuel Cell Stack Temperature

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2007-01-01

    The present work involves the development of a model for predicting the dynamic temperature of a high temperature PEM (HTPEM) fuel cell stack. The model is developed to test different thermal control strategies before implementing them in the actual system. The test system consists of a prototype...... parts, where also the temperatures are measured. The heat balance of the system involves a fuel cell model to describe the heat added by the fuel cells when a current is drawn. Furthermore the model also predicts the temperatures, when heating the stack with external heating elements for start-up, heat...... the stack at a high stoichiometric air flow. This is possible because of the PBI fuel cell membranes used, and the very low pressure drop in the stack. The model consists of a discrete thermal model dividing the stack into three parts: inlet, middle and end and predicting the temperatures in these three...

  6. Direct methanol fuel cell stack based on MEMS technology

    Science.gov (United States)

    Zhang, Yufeng; Tang, Xiaochuan; Yuan, Zhenyu; Liu, Xiaowei

    2008-10-01

    This paper presents a design configuration of silicon-based micro direct methanol fuel cell (DMFC) stack in a planar array. The integrated series connection is oriented in a "flip-flop" configuration with electrical interconnections made by thin-film metal layers that coat the flow channels etched in the silicon substrate. The configuration features small connection space and low contact resistance. The MEMS fabrication process was utilized to fabricate the silicon plates of DMFC stack. This DMFC stack with an active area of 64mm x 11mm was characterized at room temperature and normal atmosphere. Experimental results show that the prototype stack is able to generate an open-circuit voltage of 2.7V and a maximum power density of 2.2mW/cm2, which demonstrate the feasibility of this new DMFC stack configuration.

  7. Deformation Induced Microtwins and Stacking Faults in Aluminum Single Crystal

    Science.gov (United States)

    Han, W. Z.; Cheng, G. M.; Li, S. X.; Wu, S. D.; Zhang, Z. F.

    2008-09-01

    Microtwins and stacking faults in plastically deformed aluminum single crystal were successfully observed by high-resolution transmission electron microscope. The occurrence of these microtwins and stacking faults is directly related to the specially designed crystallographic orientation, because they were not observed in pure aluminum single crystal or polycrystal before. Based on the new finding above, we propose a universal dislocation-based model to judge the preference or not for the nucleation of deformation twins and stacking faults in various face-centered-cubic metals in terms of the critical stress for dislocation glide or twinning by considering the intrinsic factors, such as stacking fault energy, crystallographic orientation, and grain size. The new finding of deformation induced microtwins and stacking faults in aluminum single crystal and the proposed model should be of interest to a broad community.

  8. Physical Sciences Laboratory 1 Rooftop Stack Mixing Study

    Energy Technology Data Exchange (ETDEWEB)

    Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Antonio, Ernest J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-30

    To address concerns about worker exposures on the Physical Science Laboratory (PSL) rooftop, a tracer study was conducted to measure gaseous tracer concentrations downwind of six stacks on the southern half of the PSL building (PSL-1). These concerns were raised, in part, due to the non-standard configuration of the stacks on this building. Five of the six stacks were only about 8 feet tall, with one shorter stack that was essentially level with the roof deck. These stacks were reconfigured in August 2016, and these exhaust points on PSL-1 are now 18 feet tall. This report describes the objectives of the tracer tests performed on PSL-1, provides an overview of how the tests were executed, and presents results of the tests. The tests on the PSL rooftop were a follow-on project from a similar study performed on the LSL-II ventilation exhaust (Flaherty and Antonio, 2016).

  9. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball

    2010-01-01

    Operational Experience At the end of the first full-year running period of LHC, CMS is established as a reliable, robust and mature experiment. In particular common systems and infrastructure faults accounted for <0.6 % CMS downtime during LHC pp physics. Technical operation throughout the entire year was rather smooth, the main faults requiring UXC access being sub-detector power systems and rack-cooling turbines. All such problems were corrected during scheduled technical stops, in the shadow of tunnel access needed by the LHC, or in negotiated accesses or access extensions. Nevertheless, the number of necessary accesses to the UXC averaged more than one per week and the technical stops were inevitably packed with work packages, typically 30 being executed within a few days, placing a high load on the coordination and area management teams. It is an appropriate moment for CMS Technical Coordination to thank all those in many CERN departments and in the Collaboration, who were involved in CMS techni...

  10. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball

    2010-01-01

    Operational Experience Since the closure of the detector in February, the technical operation of CMS has been quite smooth and reliable. Some minor interventions in UXC were required to cure failures of power supplies, fans, readout boards and rack cooling connections, but all these failures were repaired in scheduled technical stops or parasitically during access dedicated to fixing LHC technical problems. The only occasion when CMS had to request an access between fills was to search for the source of an alarm from the leak-detection cables mounted in the DT racks. After a few minutes of diagnostic search, a leaking air-purge was found. Replacement was complete within 2 hours. This incident demonstrated once more the value of these leak detection cables; the system will be further extended (during the end of year technical stop) to cover more racks in UXC and the floor beneath the detector. The magnet has also been operating reliably and reacted correctly to the 14s power cut on 29 May (see below). In or...

  11. Technical endoscopy

    International Nuclear Information System (INIS)

    Cavalar, K.O.

    1988-01-01

    A survey is provided on different versions of endoscopes, taking into account the new developments of video endoscopy. With a variety of practical examples it is shown that technical tests using endoscopy are a demanding task for nondestructive testing, whose requirements can only be met on a customized basis. (orig./HP) [de

  12. Technical Training: Technical Training Seminar

    CERN Multimedia

    2004-01-01

    TECHNICAL TRAINING Monique Duval tel. 74924 technical.training@cern.ch Monday 9 February 2004 From 10:00 to 12:00 - IT Auditorium - bldg. 31, 3rd floor ANSOFT High-Frequency Seminar David Prestaux, Application Engineer, ANSOFT F-78535 BUC, France This Technical Training seminar will present two Ansoft application products: Ansoft HFSS and Ansoft Designer. Ansoft HFSS makes use of the Finite Element Method (FEM) to calculate field solutions from first principles. It can accurately predict all high-frequency behaviours such as dispersion, mode conversion, and losses due to materials and radiation. Ansoft Designer is a suite of design tools to fully integrate high-frequency, physics-based electromagnetic simulations into a seamless system-level simulation environment. Ansoft Designer uses a simple interface to give complete control over every design task, by a method allowing multiple solvers, Solver on Demand. • Introduction • Overview of the Ansoft Total solution • Ansoft HFSS 9...

  13. Reflector imaging by diffraction stacking with stacking velocity analysis; Jugo sokudo kaiseki wo tomonau sanran jugoho ni yoru hanshamen imaging

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, J.; Rokugawa, S.; Kato, Y. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering; Yokota, T. [Japan National Oil Corp., Tokyo (Japan); Miyazaki, T. [Geological Survey of Japan, Tsukuba (Japan)

    1997-10-22

    Concerning seismic reflection survey for geometrical arrangement between pits, the scattering stacking method with stacking velocity analysis is compared with the CDP (common depth point horizontal stacking method). The advantages of the CDP supposedly include the following. Since it presumes an average velocity field, it can determine velocities having stacking effects. The method presumes stratification and, since such enables the division of huge quantities of observed data into smaller groups, more data can be calculated in a shorter time period. The method has disadvantages, attributable to its presuming an average velocity field, that accuracy in processing is lower when the velocity field contrast is higher, that accuracy in processing is low unless stratification is employed, and that velocities obtained from stacking velocity analysis are affected by dipped structures. Such shortcomings may be remedied in the scattering stacking method with stacking velocity analysis. Possibilities are that, as far as the horizontal reflection plane is concerned, it may yield stack records higher in S/N ratio than the CDP. Findings relative to dipped reflection planes will be introduced at the presentation. 6 refs., 12 figs.

  14. Graphite stack corrosion of BUGEY-1 reactor (synthesis)

    International Nuclear Information System (INIS)

    Petit, A.; Brie, M.

    1996-01-01

    The definitive shutdown date for the BUGEY-1 reactor was May 27th, 1994, after 12.18 full power equivalent years and this document briefly describes some of the feedback of experience from operation of this reactor. The radiolytic corrosion of graphite stack is the major problem for BUGEY-1 reactor, despite the inhibition of the reaction by small quantities of CH 4 added to the coolant gas. The mechanical behaviour of the pile is predicted using the ''INCA'' code (stress calculation), which uses the results of graphite weight loss variation determined using the ''USURE'' code. The weight loss of graphite is determined by annually taking core samples from the channel walls. The results of the last test programme undertaken after the definitive shutdown of BUGEY-1 have enabled an experimental graph to be established showing the evolution of the compression resistance (perpendicular and parallel direction to the extrusion axis) as a function of the weight loss. The numerous analyses, made on the samples carried out in the most sensitive regions, have allowed to verify that no brutal degradation of the mechanical properties of graphite happens for the high value of weight loss up to 40% (maximum weight loss reached locally). (author). 10 refs, 3 figs, 4 tabs

  15. Black Hole Spectroscopy with Coherent Mode Stacking.

    Science.gov (United States)

    Yang, Huan; Yagi, Kent; Blackman, Jonathan; Lehner, Luis; Paschalidis, Vasileios; Pretorius, Frans; Yunes, Nicolás

    2017-04-21

    The measurement of multiple ringdown modes in gravitational waves from binary black hole mergers will allow for testing the fundamental properties of black holes in general relativity and to constrain modified theories of gravity. To enhance the ability of Advanced LIGO/Virgo to perform such tasks, we propose a coherent mode stacking method to search for a chosen target mode within a collection of multiple merger events. We first rescale each signal so that the target mode in each of them has the same frequency and then sum the waveforms constructively. A crucial element to realize this coherent superposition is to make use of a priori information extracted from the inspiral-merger phase of each event. To illustrate the method, we perform a study with simulated events targeting the ℓ=m=3 ringdown mode of the remnant black holes. We show that this method can significantly boost the signal-to-noise ratio of the collective target mode compared to that of the single loudest event. Using current estimates of merger rates, we show that it is likely that advanced-era detectors can measure this collective ringdown mode with one year of coincident data gathered at design sensitivity.

  16. ATLAS software stack on ARM64

    CERN Document Server

    Smith, Joshua Wyatt; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment explores new hardware and software platforms that, in the future, may be more suited to its data intensive workloads. One such alternative hardware platform is the ARM architecture, which is designed to be extremely power efficient and is found in most smartphones and tablets. CERN openlab recently installed a small cluster of ARM 64-bit evaluation prototype servers. Each server is based on a single-socket ARM 64-bit system on a chip, with 32 Cortex-A57 cores. In total, each server has 128 GB RAM connected with four fast memory channels. This paper reports on the port of the ATLAS software stack onto these new prototype ARM64 servers. This included building the "external" packages that the ATLAS software relies on. Patches were needed to introduce this new architecture into the build as well as patches that correct for platform specific code that caused failures on non-x86 architectures. These patches were applied such that porting to further platforms will need no or only very little adj...

  17. Long Duration Balloon Charge Controller Stack Integration

    Science.gov (United States)

    Clifford, Kyle

    NASA and the Columbia Scientific Balloon Facility are interested in updating the design of the charge controller on their long duration balloon (LDB) in order to enable the charge controllers to be directly interfaced via RS232 serial communication by a ground testing computers and the balloon's flight computer without the need to have an external electronics stack. The design involves creating a board that will interface with the existing boards in the charge controller in order to receive telemetry from and send commands to those boards, and interface with a computer through serial communication. The inputs to the board are digital status inputs indicating things like whether the photovoltaic panels are connected or disconnected; and analog inputs with information such as the battery voltage and temperature. The outputs of the board are 100ms duration command pulses that will switch relays that do things like connect the photovoltaic panels. The main component of this design is a PIC microcontroller which translates the outputs of the existing charge controller into serial data when interrogated by a ground testing or flight computer. Other components involved in the design are an AD7888 12-bit analog to digital converter, a MAX3232 serial transceiver, various other ICs, capacitors, resistors, and connectors.

  18. Lithiation-induced shuffling of atomic stacks

    KAUST Repository

    Nie, Anmin

    2014-09-10

    In rechargeable lithium-ion batteries, understanding the atomic-scale mechanism of Li-induced structural evolution occurring at the host electrode materials provides essential knowledge for design of new high performance electrodes. Here, we report a new crystalline-crystalline phase transition mechanism in single-crystal Zn-Sb intermetallic nanowires upon lithiation. Using in situ transmission electron microscopy, we observed that stacks of atomic planes in an intermediate hexagonal (h-)LiZnSb phase are "shuffled" to accommodate the geometrical confinement stress arising from lamellar nanodomains intercalated by lithium ions. Such atomic rearrangement arises from the anisotropic lithium diffusion and is accompanied by appearance of partial dislocations. This transient structure mediates further phase transition from h-LiZnSb to cubic (c-)Li2ZnSb, which is associated with a nearly "zero-strain" coherent interface viewed along the [001]h/[111]c directions. This study provides new mechanistic insights into complex electrochemically driven crystalline-crystalline phase transitions in lithium-ion battery electrodes and represents a noble example of atomic-level structural and interfacial rearrangements.

  19. Weyl magnons in noncoplanar stacked kagome antiferromagnets

    Science.gov (United States)

    Owerre, S. A.

    2018-03-01

    Weyl nodes have been experimentally realized in photonic, electronic, and phononic crystals. However, magnonic Weyl nodes are yet to be seen experimentally. In this paper, we propose Weyl magnon nodes in noncoplanar stacked frustrated kagome antiferromagnets, naturally available in various real materials. Most crucially, the Weyl nodes in the current system occur at the lowest excitation and possess a topological thermal Hall effect, therefore they are experimentally accessible at low temperatures due to the population effect of bosonic quasiparticles. In stark contrast to other magnetic systems, the current Weyl nodes do not rely on time-reversal symmetry breaking by the magnetic order. Rather, they result from explicit macroscopically broken time reversal symmetry by the scalar spin chirality of noncoplanar spin textures and can be generalized to chiral spin liquid states. Moreover, the scalar spin chirality gives a real space Berry curvature which is not available in previously studied magnetic Weyl systems. We show the existence of magnon arc surface states connecting projected Weyl magnon nodes on the surface Brillouin zone. We also uncover the first realization of triply-degenerate nodal magnon point in the noncollinear regime with zero scalar spin chirality.

  20. Stacking faults and phase changes in Mg-doped InGaN grown on Si

    International Nuclear Information System (INIS)

    Liliental-Weber, Zuzanna; Yu, Kin M.; Reichertz, Lothar A.; Ager, Joel W.; Walukiewicz, Wladek; Schaff, William J.; Hawkridge, Michael E.

    2009-01-01

    We report evidence for the role of Mg in the formation of basal stacking faults and a phase transition in In x Ga 1-x N layers doped with Mg grown by molecular beam epitaxy on Si(111) substrates with AlN buffer layers. Several samples with varying In content between x∝0.1 and x∝0.3 are examined by transmission electron microscopy and other techniques. High densities of basal stacking faults are observed in the central region of the InGaN layer away from the substrate or layer surface, but at varying depths within this region. Selected area diffraction patterns show that while the InGaN layer is initially in the wurtzite phase (and of good quality) AlN buffer layer, there is a change to the zinc blende phase in the upper part of the InGaN layer. SIMS measurements show that the Mg concentration drops from a maximum to a steady concentration coinciding with the presence of the basal stacking faults. There is little change in In or Ga concentrations in the same area. High-resolution electron microscopy from the area of the stacking faults confirms that the change to the cubic phase is abrupt across one such fault. These results indicate that Mg plays a role in the formation of stacking faults and the phase change observed in In x Ga 1-x N alloys. We also consider the role of In in the formation of these defects. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. On-line stacking techniques for the nonaqueous capillary electrophoretic determination of acrylamide in processed food

    International Nuclear Information System (INIS)

    Tezcan, Filiz; Erim, F. Bedia

    2008-01-01

    In the present study, field amplified sample stacking (FASS) techniques in the nonaqueous capillary electrophoresis method (NACE) were introduced for the on-line concentration of the acrylamide to improve acrylamide detection at 210 nm by diode-array detection. Acetonitrile (ACN) as a nonaqueous solvent permits acrylamide to be protonated through the change of its acid-base chemistry, allowing capillary electrophoretic separation of this compound. Choosing 30 mmol L -1 HClO 4 , 20 mmol L -1 NaClO 4 , 218 mmol L -1 CH 3 COOH in ACN as the separation electrolyte and employing sample stacking methods, the LOD value of acrylamide was decreased to 2.6 ng mL -1 with electrokinetic injection and 4.4 ng mL -1 with hydrodynamic injection. Optimized stacking conditions were applied to the determination of acrylamide in several foodstuffs. The method is simple, rapid, inexpensive, and widely applicable for the determination of acrylamide in food samples

  2. Efficiency of Polymer Electrolyte Membrane Fuel Cell Stack

    Directory of Open Access Journals (Sweden)

    Hans Bosma

    2011-08-01

    Full Text Available This paper applies a feedforward control of optimal oxygen excess ratio that maximize net power (improve efficiency of a NedStack P8.0-64 PEM fuel cell stack (FCS system. Net powers profile as a function of oxygen excess ratio for some points of operation are analyzed by using FCS model. The relationships between stack current and the corresponding control input voltage that gives an optimal oxygen excess ratio are used to design a feedforward control scheme. The results of this scheme are compared to the results of a feedforward control using a constant oxygen excess ratio. Simulation results show that optimal oxygen excess ratio improves fuel cell performance compared to the results of constant oxygen excess ratio. The same procedures are performed experimentally for the FCS system. The behaviour of the net power of the fuel cell stack with respect to the variation of oxygen excess ratio is analyzed to obtain optimal values. Data of stack current and the corresponding voltage input to the compressor that gives optimal values of oxygen excess ratio are used to develop a feedforward control. Feedforward control based on constant and optimal oxygen excess ratio control, are implemented in the NedStack P8.0-64 PEM fuel cell stack system by using LabVIEW. Implementation results shows that optimal oxygen excess ratio control improves the fuel cell performance compared to the constant oxygen excess ratio control.

  3. Stacking and Analysis of Melamine in Milk Products with Acetonitrile-Salt Stacking Technique in Capillary Electrophoresis

    Directory of Open Access Journals (Sweden)

    Yu Kong

    2014-01-01

    Full Text Available Melamine was measured in real milk products with capillary electrophoresis (CE based on acetonitrile-salt stacking (ASS method. Real milk samples were deproteinized with acetonitrile at a final concentration of 60% (v/v and then injected hydrodynamically at 50 mBar for 40.0 s. The optimized buffer contains 80.0 mmol/L pH 2.8 phosphates. Melamine could be detected within 20.0 min at +10 kV with a low limit of detection (LOD of 0.03 μmol/L. Satisfactory reproducibility (inter- and intraday RSD% both for migration time and peak area was lower than 5.0% and a wide linearity range of 0.05 μmol/L ~ 10.0 μmol/L were achieved. The proposed method was suitable for routine assay of MEL in real milk samples that was subjected to a simple treatment step.

  4. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball

    Overview From a technical perspective, CMS has been in “beam operation” state since 6th November. The detector is fully closed with all components operational and the magnetic field is normally at the nominal 3.8T. The UXC cavern is normally closed with the radiation veto set. Access to UXC is now only possible during downtimes of LHC. Such accesses must be carefully planned, documented and carried out in agreement with CMS Technical Coordination, Experimental Area Management, LHC programme coordination and the CCC. Material flow in and out of UXC is now strictly controlled. Access to USC remains possible at any time, although, for safety reasons, it is necessary to register with the shift crew in the control room before going down.It is obligatory for all material leaving UXC to pass through the underground buffer zone for RP scanning, database entry and appropriate labeling for traceability. Technical coordination (notably Stephane Bally and Christoph Schaefer), the shift crew and run ...

  5. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball and W. Zeuner

    2011-01-01

    In this report we will review the main achievements of the Technical Stop and the progress of several centrally-managed projects to support CMS operation and maintenance and prepare the way for upgrades. Overview of the extended Technical Stop  The principal objectives of the extended Technical Stop affecting the detector itself were the installation of the TOTEM T1 telescopes on both ends, the readjustment of the alignment link-disk in YE-2, the replacement of the light-guide sleeves for all PMs of both HFs, and some repairs on TOTEM T2 and CASTOR. The most significant tasks were, however, concentrated on the supporting infrastructure. A detailed line-by-line leak search was performed in the C6F14 cooling system of the Tracker, followed by the installation of variable-frequency drives on the pump motors of the SS1 and SS2 tracker cooling plants to reduce pressure transients during start-up. In the electrical system, larger harmonic filters were installed in ...

  6. Consolidity: Stack-based systems change pathway theory elaborated

    Directory of Open Access Journals (Sweden)

    Hassen Taher Dorrah

    2014-06-01

    Full Text Available This paper presents an elaborated analysis for investigating the stack-based layering processes during the systems change pathway. The system change pathway is defined as the path resulting from the combinations of all successive changes induced on the system when subjected to varying environments, activities, events, or any excessive internal or external influences and happenings “on and above” its normal stands, situations or set-points during its course of life. The analysis is essentially based on the important overall system paradigm of “Time driven-event driven-parameters change”. Based on this paradigm, it is considered that any affected activity, event or varying environment is intelligently self-recorded inside the system through an incremental consolidity-scaled change in system parameters of the stack-based layering types. Various joint stack-based mathematical and graphical approaches supported by representable case studies are suggested for the identification, extraction, and processing of various stack-based systems changes layering of different classifications and categorizations. Moreover, some selected real life illustrative applications are provided to demonstrate the (infinite stack-based identification and recognition of the change pathway process in the areas of geology, archeology, life sciences, ecology, environmental science, engineering, materials, medicine, biology, sociology, humanities, and other important fields. These case studies and selected applications revealed that there are general similarities of the stack-based layering structures and formations among all the various research fields. Such general similarities clearly demonstrate the global concept of the “fractals-general stacking behavior” of real life systems during their change pathways. Therefore, it is recommended that concentrated efforts should be expedited toward building generic modular stack-based systems or blocks for the mathematical

  7. Loop Entropy Assists Tertiary Order: Loopy Stabilization of Stacking Motifs

    Directory of Open Access Journals (Sweden)

    Daniel P. Aalberts

    2011-11-01

    Full Text Available The free energy of an RNA fold is a combination of favorable base pairing and stacking interactions competing with entropic costs of forming loops. Here we show how loop entropy, surprisingly, can promote tertiary order. A general formula for the free energy of forming multibranch and other RNA loops is derived with a polymer-physics based theory. We also derive a formula for the free energy of coaxial stacking in the context of a loop. Simulations support the analytic formulas. The effects of stacking of unpaired bases are also studied with simulations.

  8. Mixed Mechanism of Lubrication by Lipid Bilayer Stacks.

    Science.gov (United States)

    Boţan, Alexandru; Joly, Laurent; Fillot, Nicolas; Loison, Claire

    2015-11-10

    Although the key role of lipid bilayer stacks in biological lubrication is generally accepted, the mechanisms underlying their extreme efficiency remain elusive. In this article, we report molecular dynamics simulations of lipid bilayer stacks undergoing load and shear. When the hydration level is reduced, the velocity accommodation mechanism changes from viscous shear in hydration water to interlayer sliding in the bilayers. This enables stacks of hydrated lipid bilayers to act as efficient boundary lubricants for various hydration conditions, structures, and mechanical loads. We also propose an estimation for the friction coefficient; thanks to the strong hydration forces between lipid bilayers, the high local viscosity is not in contradiction with low friction coefficients.

  9. On $k$-stellated and $k$-stacked spheres

    OpenAIRE

    Bagchi, Bhaskar; Datta, Basudeb

    2012-01-01

    We introduce the class $\\Sigma_k(d)$ of $k$-stellated (combinatorial) spheres of dimension $d$ ($0 \\leq k \\leq d + 1$) and compare and contrast it with the class ${\\cal S}_k(d)$ ($0 \\leq k \\leq d$) of $k$-stacked homology $d$-spheres. We have $\\Sigma_1(d) = {\\cal S}_1(d)$, and $\\Sigma_k(d) \\subseteq {\\cal S}_k(d)$ for $d \\geq 2k - 1$. However, for each $k \\geq 2$ there are $k$-stacked spheres which are not $k$-stellated. The existence of $k$-stellated spheres which are not $k$-stacked remains...

  10. Optimized stacked RADFETs for milli-rad dose measurement

    International Nuclear Information System (INIS)

    O'Connell, B.; Lane, B.; Mohammadzadeh, A.

    1999-01-01

    This paper details the improvements in the design of stacked RADFETs for increased radiation sensitivity. The issues of high read-out voltage has been shown to be a draw-back. It is the body (bulk)effect factor that is responsible for the increased overall stack Threshold voltage (V T ), which is greater than the sum of the individual devices V T . From extensive process and device simulation and resultant circuit simulation, modified stack structures have been proposed and designed. New and exciting result of lower initial (pre-irradiation) output voltage as well as increased radiation sensitivity will be presented. (author)

  11. Technical communications

    International Nuclear Information System (INIS)

    Krueger, D.A.

    1987-01-01

    Bitter almond oil (benzaldehyde), a flavoring compound used in many foods, was isolated from apricot kernels; 2 synthetic benzaldehyde samples were obtained from commercial sources. All samples were analyzed for radiocarbon ( 14 C) content. The natural sample yielded a value consistent with its natural origin (approximately 116% of Modern Standard Activity), while the synthetic samples were devoid of 14 C activity as expected for a petrochemical material. Implications for quality control of bitter almond oil are discussed

  12. Technical Training: Technical Training Seminar

    CERN Multimedia

    2004-01-01

    Tuesday 30 March TECHNICAL TRAINING SEMINAR From 9:00 to 12:00 and from 13:00 to 16:00 hrs - Council Chamber, Salle B, Salle des Pas Perdus National Instruments (NI) on Tour 2004 Claudia Jüngel, Evrem Yarkin, Joel Clerc, Hervé Baour / NATIONAL INSTRUMENTS The special event NI on Tour 2004, run in Germany, Austria and Switzerland, will be at CERN on March 30. Technical seminars and free introductory courses will be offered all day long in the Council Chamber, Salle B, and Salle des Pas Perdus (buildings 61 and 503). Technical conferences: 09:00 - 12:00 Data acquisition systems on PCs. Industrial measurement and control techniques. 13:00 - 16:00 Advanced LabVIEW software and PXI instrumentation. Measuring instruments and system components for teststand automation. Introductory courses: 09:00 - 12:00 DIAdem: Data analysis and presentation 13:00 - 16:00 Data acquisition with LabVIEW Language: English and French Free special seminar. Registration is recommended with National Instruments Switzerland (please sp...

  13. Technical Training: Technical Training Seminar

    CERN Multimedia

    2004-01-01

    Tuesday 30 March TECHNICAL TRAINING SEMINAR From 9:00 to 12:00 and from 13:00 to 16:00 hrs - Council Chamber, Salle B, Salle des Pas Perdus National Instruments (NI) on Tour 2004 Claudia Jüngel, Evrem Yarkin, Joel Clerc, Hervé Baour / NATIONAL INSTRUMENTS The special event NI on Tour 2004, run in Germany, Austria and Switzerland, will be at CERN on March 30. Technical seminars and free introductory courses will be offered all day long in the Council Chamber, Salle B, and Salle des Pas Perdus (buildings 61 and 503). Technical conferences: 09:00 - 12:00 Data acquisition systems on PCs. Industrial measurement and control techniques. 13:00 - 16:00 Advanced LabVIEW software and PXI instrumentation. Measuring instruments and system components for teststand automation. Introductory courses: 09:00 - 12:00 DIAdem: Data analysis and presentation 13:00 - 16:00 Data acquisition with LabVIEW Language: English and French Free special seminar. Registration is recommended with National Instruments Swi...

  14. Fuel flow distribution in SOFC stacks revealed by impedance spectroscopy

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Hjelm, Johan; Barfod, Rasmus

    2014-01-01

    . An operating stack is subject to compositional gradients in the gaseous reactant streams, and temperature gradients across each cell and across the stack, which complicates detailed analysis. An experimental stack with low ohmic resistance from Topsoe Fuel Cell A/S was characterized using Electrochemical...... Impedance Spectroscopy (EIS). The stack measurement geometry was optimized for EIS by careful selection of the placement of current feeds and voltage probes in order to minimize measurement errors. It was demonstrated that with the improved placement of current feeds and voltage probes it is possible...... to separate the loss contributions in an ohmic and a polarization part and that the low frequency response is useful in detecting mass transfer limitations. This methodology can be used to detect possible minor changes in the supply of gas to the individual cells, which is important when going to high fuel...

  15. Simulation of magnetization and levitation characteristics of HTS tape stacks

    Science.gov (United States)

    Anischenko, I. V.; Pokrovskii, S. V.; Mineev, N. A.

    2017-12-01

    In this work it is presented a computational model of a magnetic levitation system based on stacks of high-temperature second generation superconducting tapes (HTS) GdBa2Cu3O7-x. Calculated magnetic field and the current distributions in the system for different stacks geometries in the zero-field cooling mode are also presented. The magnetization curves of the stacks in the external field of a permanent NdFeB magnet and the levitation force dependence on the gap between the magnet and the HTS tapes stack were obtained. A model of the magnetic system, oriented to levitation application, is given. Results of modeling were compared with the experimental data.

  16. Fast principal component analysis for stacking seismic data

    Science.gov (United States)

    Wu, Juan; Bai, Min

    2018-04-01

    Stacking seismic data plays an indispensable role in many steps of the seismic data processing and imaging workflow. Optimal stacking of seismic data can help mitigate seismic noise and enhance the principal components to a great extent. Traditional average-based seismic stacking methods cannot obtain optimal performance when the ambient noise is extremely strong. We propose a principal component analysis (PCA) algorithm for stacking seismic data without being sensitive to noise level. Considering the computational bottleneck of the classic PCA algorithm in processing massive seismic data, we propose an efficient PCA algorithm to make the proposed method readily applicable for industrial applications. Two numerically designed examples and one real seismic data are used to demonstrate the performance of the presented method.

  17. Static analysis of worst-case stack cache behavior

    DEFF Research Database (Denmark)

    Jordan, Alexander; Brandner, Florian; Schoeberl, Martin

    2013-01-01

    Utilizing a stack cache in a real-time system can aid predictability by avoiding interference that heap memory traffic causes on the data cache. While loads and stores are guaranteed cache hits, explicit operations are responsible for managing the stack cache. The behavior of these operations can......-graph, the worst-case bounds can be efficiently yet precisely determined. Our evaluation using the MiBench benchmark suite shows that only 37% and 21% of potential stack cache operations actually store to and load from memory, respectively. Analysis times are modest, on average running between 0.46s and 1.30s per...... be analyzed statically. We present algorithms that derive worst-case bounds on the latency-inducing operations of the stack cache. Their results can be used by a static WCET tool. By breaking the analysis down into subproblems that solve intra-procedural data-flow analysis and path searches on the call...

  18. A Stack Cache for Real-Time Systems

    DEFF Research Database (Denmark)

    Schoeberl, Martin; Nielsen, Carsten

    2016-01-01

    Real-time systems need time-predictable computing platforms to allowfor static analysis of the worst-case execution time. Caches are important for good performance, but data caches arehard to analyze for the worst-case execution time. Stack allocated data has different properties related to local......Real-time systems need time-predictable computing platforms to allowfor static analysis of the worst-case execution time. Caches are important for good performance, but data caches arehard to analyze for the worst-case execution time. Stack allocated data has different properties related...... to locality, lifetime, and static analyzability of access addresses comparedto static or heap allocated data. Therefore, caching of stack allocateddata benefits from having its own cache. In this paper we present a cache architecture optimized for stack allocateddata. This cache is additional to the normal...

  19. DBaaS with OpenStack Trove

    CERN Document Server

    Giardini, Andrea

    2013-01-01

    The purpose of the project was to evaluate the Trove component for OpenStack, understand if it can be used with the CERN infrastructure and report the benefits and disadvantages of this software. Currently, databases for CERN projects are provided by a DbaaS software developed inside the IT-DB group. This solution works well with the actual infrastructure but it is not easy to maintain. With the migration of the CERN infrastructure to OpenStack the Database group started to evaluate the Trove component. Instead of mantaining an own DbaaS service it can be interesting to migrate everything to OpenStack and replace the actual DbaaS software with Trove. This way both virtual machines and databases will be managed by OpenStack itself.

  20. Stacking dependence of carrier transport properties in multilayered black phosphorous.

    Science.gov (United States)

    Sengupta, A; Audiffred, M; Heine, T; Niehaus, T A

    2016-02-24

    We present the effect of different stacking orders on carrier transport properties of multi-layer black phosphorous. We consider three different stacking orders AAA, ABA and ACA, with increasing number of layers (from 2 to 6 layers). We employ a hierarchical approach in density functional theory (DFT), with structural simulations performed with generalized gradient approximation (GGA) and the bandstructure, carrier effective masses and optical properties evaluated with the meta-generalized gradient approximation (MGGA). The carrier transmission in the various black phosphorous sheets was carried out with the non-equilibrium green's function (NEGF) approach. The results show that ACA stacking has the highest electron and hole transmission probabilities. The results show tunability for a wide range of band-gaps, carrier effective masses and transmission with a great promise for lattice engineering (stacking order and layers) in black phosphorous.

  1. SEE on Different Layers of Stacked-SRAMs

    CERN Document Server

    Gupta, V; Tsiligiannis, G; Rousselet, M; Mohammadzadeh, A; Javanainen, A; Virtanen, A; Puchner, H; Saigné, F; Wrobel, F; Dilillo, L

    2015-01-01

    This paper presents heavy-ion and proton radiation test results of a 90 nm COTS SRAM with stacked structure. Radiation tests were made using high penetration heavy-ion cocktails at the HIF (Belgium) and at RADEF (Finland) as well as low energy protons at RADEF. The heavy-ion SEU cross-section showed an unusual profile with a peak at the lowest LET (heavy-ion with the highest penetration range). The discrepancy is due to the fact that the SRAM is constituted of two vertically stacked dice. The impact of proton testing on the response of both stacked dice is presented. The results are discussed and the SEU cross-sections of the upper and lower layers are compared. The impact of the stacked structure on the proton SEE rate is investigated.

  2. INDOT Technical Training Plan : [Technical Summary

    Science.gov (United States)

    2012-01-01

    A wide range of job classifications, increasing technical : performance expectations, licensing and certification requirements, : budget restrictions and frequent department : reorganization has made technical training of employees : more difficult, ...

  3. Tracer gas experiment to verify the dispersion from a tall stack

    International Nuclear Information System (INIS)

    Sivertsen, B.; Irwin, J.S.

    1996-01-01

    At the request of the Ministerios de Obras Publicas y Urbanismo (MOPU) in Madrid, the Norwegian Institute for Air Research (NILU) planned and carried out a comprehensive field experiment at the Andorra (Teruel) power plant in Spain. All together, eleven releases of sulfur hexafluoride (SF6) tracer were carried out at the 1,200 MW electric coal fired power plant. The tracer was emitted into the atmosphere from the 343 m high stack, stack exit diameter of 9 m. The stack gas emission characteristics were nearly constant during the period having an exit temperature of 175.1 C (1.9), exit velocity of 35.5 m/s (0.14) and sulfur dioxide (SO 2 ) emission rate of 46.1 x 10 3 kg/hr (5.15 x 10 3 ); standard deviations are listed in parentheses. Samples were taken at the surface along sampling arcs located approximately 8, 23, 43 and 75 km downwind. The releases were undertaken during typical late spring daytime conditions. The synoptic weather conditions were dominated by a large high pressure system on the Atlantic, west of Spain. Fronts were passing the area from the north and a low pressure system was developing over central Europe (Germany). Winds at the surface were generally brisk from the northwest at 7 to 12 m/s

  4. Prolonged incubation and stacked film exposure improve sensitivity in western blotting.

    Science.gov (United States)

    Luo, Haitao; Rankin, Gary O; Straley, Shannon; Chen, Yi Charlie

    2011-01-01

    Western blotting is a basic technique for protein detection. For proteins of less abundance or antibodies of poorer quality, an increased sensitivity is often desired. Although it is commonly known that higher concentrations of antibodies and prolonged film exposure times will help improve sensitivity in western blots, both measures come with their own risks, and it is often unclear to which extent these measures should be applied. We conducted time-course studies to investigate protein-antibody interactions and primary antibody-secondary antibody interactions in western blotting. We also propose a protocol of stacked film exposure and have tested it in standard curves and cancer cell samples. Our study found that protein-primary antibody interactions and primary antibody-secondary antibody interactions could take a longer time than commonly used "one hour" or "overnight", and in some cases longer than 48h, to reach its maximum binding. We also show that the modified protocol of stacked film exposure works well for both standard curves and biological samples, reaching a maximum sensitivity in western blots without blurring target signals or increasing backgrounds. In addition to regular optimization of antibody concentrations and film exposure time, a prolonged incubation with antibodies and stacked film exposure will also help improve sensitivity and reduce background in western blotting. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Golden-ratio rotated stack-of-stars acquisition for improved volumetric MRI.

    Science.gov (United States)

    Zhou, Ziwu; Han, Fei; Yan, Lirong; Wang, Danny J J; Hu, Peng

    2017-12-01

    To develop and evaluate an improved stack-of-stars radial sampling strategy for reducing streaking artifacts. The conventional stack-of-stars sampling strategy collects the same radial angle for every partition (slice) encoding. In an undersampled acquisition, such an aligned acquisition generates coherent aliasing patterns and introduces strong streaking artifacts. We show that by rotating the radial spokes in a golden-angle manner along the partition-encoding direction, the aliasing pattern is modified, resulting in improved image quality for gridding and more advanced reconstruction methods. Computer simulations were performed and phantom as well as in vivo images for three different applications were acquired. Simulation, phantom, and in vivo experiments confirmed that the proposed method was able to generate images with less streaking artifact and sharper structures based on undersampled acquisitions in comparison with the conventional aligned approach at the same acceleration factors. By combining parallel imaging and compressed sensing in the reconstruction, streaking artifacts were mostly removed with improved delineation of fine structures using the proposed strategy. We present a simple method to reduce streaking artifacts and improve image quality in 3D stack-of-stars acquisitions by re-arranging the radial spoke angles in the 3D partition direction, which can be used for rapid volumetric imaging. Magn Reson Med 78:2290-2298, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  6. Modeling of a Stacked Power Module for Parasitic Inductance Extraction

    Science.gov (United States)

    2017-09-15

    ARL-TR-8138 ● SEP 2017 US Army Research Laboratory Modeling of a Stacked Power Module for Parasitic Inductance Extraction by...not return it to the originator. ARL-TR-8138 ● SEP 2017 US Army Research Laboratory Modeling of a Stacked Power Module for...aware that notwithstanding any other provision of law , no person shall be subject to any penalty for failing to comply with a collection of information if

  7. National Spherical Torus Experiment (NSTX) Center Stack Upgrade

    International Nuclear Information System (INIS)

    Neumeyer, C.; Avasarala, S.; Chrzanowski, J.; Dudek, L.; Fan, H.; Hatcher, H.; Heitzenroeder, P.; Menard, J.; Ono, M.; Ramakrishnan, S.; Titus, P.; Woolley, R.; Zhan, H.

    2009-01-01

    The purpose of the NSTX Center Stack Upgrade project is to expand the NSTX operational space and thereby the physics basis for next-step ST facilities. The plasma aspect ratio (ratio of plasma major to minor radius) of the upgrade is increased to 1.5 from the original value of 1.26, which increases the cross sectional area of the center stack by a factor of ∼ 3 and makes possible higher levels of performance and pulse duration.

  8. A new method for beam stacking in storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C.M.; /Fermilab

    2008-06-01

    Recently, I developed a new beam stacking scheme for synchrotron storage rings called 'longitudinal phase-space coating' (LPSC). This scheme has been convincingly validated by multi-particle beam dynamics simulations and has been demonstrated with beam experiments at the Fermilab Recycler. Here, I present the results from both simulations and experiments. The beam stacking scheme presented here is the first of its kind.

  9. Stacking faults and phase transformations in silicon nitride

    Science.gov (United States)

    Milhet, X.; Demenet, J.-L.; Rabier, J.

    1998-11-01

    From observations of extended dislocation nodes in β silicon nitride, possible stacking fault structures in the basal plane of this compound have been investigated. It has been found that stacking fault structure is locally analogous to α silicon nitride. A phase transformation α to β or β to α can also be achieved by cooperative shear of partial dislocations with 1/3<~ngle1bar{1}00rangle Burgers vectors.

  10. LOFT diesel generator ''A'' exhaust stack seismic analysis

    International Nuclear Information System (INIS)

    Blandford, R.K.

    1978-01-01

    A stress analysis of the LOFT Diesel Generator ''A'' Exhaust Stack was performed to determine its reaction to Safe-Shutdown Earthquake loads. The exhaust stack silencer and supporting foundation was found to be inadequate for the postulated seismic accelerations. Lateral support is required to prevent overturning of the silencer pedestal and reinforcement of the 4'' x 0.5'' silencer base straps is necessary. Basic requirements for this additional support are discussed

  11. Field-induced stacking transition of biofunctionalized trilayer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Masato Nakano, C. [Flintridge Preparatory School, La Canada, California 91011 (United States); Sajib, Md Symon Jahan; Samieegohar, Mohammadreza; Wei, Tao [Dan F. Smith Department of Chemical Engineering, Lamar University, Beaumont, Texas 77710 (United States)

    2016-02-01

    Trilayer graphene (TLG) is attracting a lot of attention as their stacking structures (i.e., rhombohedral vs. Bernal) drastically affect electronic and optical properties. Based on full-atom molecular dynamics simulations, we here predict electric field-induced rhombohedral-to-Bernal transition of TLG tethered with proteins. Furthermore, our simulations show that protein's electrophoretic mobility and diffusivity are enhanced on TLG surface. This phenomenon of controllable TLG stacking transition will contribute to various applications including biosensing.

  12. Measurements of proton energy spectra using a radiochromic film stack

    Science.gov (United States)

    Filkins, T. M.; Steidle, Jessica; Ellison, D. M.; Steidle, Jeffrey; Freeman, C. G.; Padalino, S. J.; Fiksel, G.; Regan, S. P.; Sangster, T. C.

    2014-10-01

    The energy spectrum of protons accelerated from the rear-side of a thin foil illuminated with ultra-intense laser light from the OMEGA EP laser system at the University of Rochester's Laboratory for Laser Energetics (LLE) was measured using a stack of radiochromic film (RCF). The film stack consisted of four layers of Gafchromic HD-V2 film and four layers of Gafchromic MD-V2-55 film. Aluminum foils of various thicknesses were placed between each piece of RCF in the stack. This arrangement allowed protons with energies of 30 MeV to reach the back layer of RCF in the stack. The stack was placed in the detector plane of a Thomson parabola ion energy (TPIE) spectrometer. Each piece of film in the stack was scanned using a commercially available flat-bed scanner (Epson 10000XL). The resulting optical density was converted into proton fluence using an absolute calibration of the RCF obtained at the SUNY Geneseo 1.7 MV Pelletron accelerator laboratory. In these calibration measurements, the sensitivity of the radiochromic film was measured using monoenergetic protons produced by the accelerator. Details of the analysis procedure and the resulting proton energy spectra will be presented. Funded in part by a grant from the DOE through the Laboratory for Laser Energetics.

  13. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball and W. Zeuner

    2013-01-01

    For the reporting period, the CMS common systems and infrastructure worked well, without failures that caused significant data losses. One more disconnection of the magnet cold box occurred in the shadow of interruptions in data taking, caused by a series of technical faults. The recognition during 2012 that re-connection can only safely be done at around 2 T implies a minimum magnet recovery time of 12 hours and raises serious concerns about the number of ramping cycles of the magnet these incidents cause. This has triggered studies of how to make the cryo-system of the magnet more robust against failures. The proton-proton run ended just before the end-of-year CERN closure, during which CASTOR was installed on the negative end of CMS and both ZDC calorimeters were installed in TAN absorbers the LHC tunnel, in preparation for the heavy-ion run. The installation of CASTOR was an excellent “engineering test” of procedures for working in an activated environment. Despite some technical pr...

  14. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball and W. Zeuner

    2011-01-01

      Operational experience 2011 CMS is approaching the end of a very successful year of operation. Proton- proton running ended in the late afternoon of 30th October with a stunning 5.73 fb–1 delivered by LHC, of which CMS recorded 5.22 fb–1. During heavy-ion operation, which continues until 7th December, both the accelerator and the CMS detector have also performed very well. Despite the encouraging overall reliability of technical operation, several infrastructure failures which occurred since the last Bulletin are worthy of mention, with one leading for the first time to significant data-loss. On 10th July, a CERN-wide power failure brought down essentially all services including the magnet, due to an MCS setting being left in “manual” after the recent technical stop, but there was no significant damage and the detector was operational before the LHC, despite a slow and tortuous recovery (one of several indications this year that there is room for improve...

  15. TECHNICAL COORDINATION

    CERN Multimedia

    Austin Ball

    Summary of progress since last CMS week. Ten years of construction work have been completed. CMS is closed, in very close to the ideal low luminosity configuration, and performed well in the first tests with LHC beam. Behind this encouraging news is the story of a summer of intense commitment by many teams (from the collaboration and 3 CERN departments) working together, against the clock and despite many minor setbacks, to ensure that the experiment was ready to play a leading role in the excitement of September 10. Following beampipe bakeout and refill with pure neon, a magnificent effort by the ECAL group and the pt 5 technical crew made it possible to install and commission all 4 ECAL endcap Dees before the end of August. In the shadow of this activity, the barrel and forward pixel trackers and part of the beam monitoring were installed within the vac tank. The pt 5 technical teams then succeeded in safely removing the 20t installation tables and their support blocks from beneath the already installed ...

  16. Technical presentation

    CERN Multimedia

    FP Department

    2009-01-01

    07 April 2009 Technical presentation by Leuze Electronics: 14.00 – 15.00, Main Building, Room 61-1-017 (Room A) Photoelectric sensors, data identification and transmission systems, image processing systems. We at Leuze Electronics are "the sensor people": we have been specialising in optoelectronic sensors and safety technology for accident prevention for over 40 years. Our dedicated staff are all highly customer oriented. Customers of Leuze Electronics can always rely on one thing – on us! •\tFounded in 1963 •\t740 employees •\t115 MEUR turnover •\t20 subsidiaries •\t3 production facilities in southern Germany Product groups: •\tPhotoelectric sensors •\tIdentification and measurements •\tSafety devices

  17. Technical presentation

    CERN Multimedia

    FI Department

    2008-01-01

    RADIOSPARES, the leading catalogue distributor of components (electronic, electrical, automation, etc.) and industrial supplies will be at CERN on Friday 3 October 2008 (Main Building, Room B, from 9.00 a.m. to 3.00 p.m.) to introduce its new 2008/2009 catalogue. This will be the opportunity for us to present our complete range of products in more detail: 400 000 part numbers available on our web site (Radiospares France, RS International, extended range of components from other manufacturers); our new services: quotations, search for products not included in the catalogue, SBP products (Small Batch Production: packaging in quantities adapted to customers’ requirements); partnership with our focus manufacturers; demonstration of the on-line purchasing tool implemented on our web site in conjunction with CERN. RADIOSPARES will be accompanied by representatives of FLUKE and TYCO ELECTRONICS, who will make presentations, demonstrate materials and answer any technical questio...

  18. Technical presentation

    CERN Multimedia

    GS Department

    2010-01-01

    10 March 2010 DYNEOS 10:00 – 12:00 - Main Building, Room B, 61-1-009 Dyneos AG is active in the fields of photonics, laser and high-precision positioning. Our highly qualified engineer team has more than 30 years of experience in electro-optical solutions sales. The engineers are supported by a technical and administrative team. We are focused on the Swiss market and represent six suppliers (Coherent, PI Physik Instrumente, SIOS, Nanonics Imaging, APE, Ekspla) in order to give a qualified sales and service support to our customers. Our products are dedicated to the research field as well as to industry. In addition to standard catalog products, we offer custom designs to fulfill the specific needs of OEM customers or specific applications.

  19. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball and W. Zeuner

    2010-01-01

    Overview Once again, the bulk of this article reviews the intense activity of a recently completed shutdown, which, although quite unforeseeable until a few weeks before it started, proved by its success that our often advertised capability to conduct major maintenance within a two month period is real. Although safely completed, on-time to remarkable precision, the activity was not without incident, and highlighted our dependence on many experienced, specialist teams and their precise choreography. Even after the yoke was safely closed, magnet re-commissioning and beampipe pumpdown showed new and thought-provoking behaviour. The struggle to maintain adequate technical resources will be a pre-occupation over the coming months, in parallel with the start of truly sustained operation, for which various procedures are still being put in place. Planning for future shutdowns must now become a high priority, with many working groups and task forces already in existence to prepare infrastructure improvements and to...

  20. Technical Training: Technical Training Seminar

    CERN Multimedia

    2004-01-01

    TECHNICAL TRAINING Monique Duval tel. 74924 technical.training@cern.ch Tuesday 3 February 2004 From 09:00 to 13:30 - Training Centre Auditorium - bldg. 593, room 11 USB (Universal Serial Bus) CYPRESS Seminar Claudia Colombini, Field Application Engineer CYPRESS ActiveComp Electronic GmbH D-85077 MANCHING, Germany As a pioneer in USB, CYPRESS sets the standard for cost-effective solutions without sacrificing functionality, performance or reliability. Having shipped over 200 million USB devices, Cypress is the undisputed market leader and demonstrates unmatched USB expertise. With the industry's broadest selection of USB solutions, Cypress has the right silicon, software and support for every USB application, from Low-speed to High-Speed and USB On-The-Go (OTG). 9:00 - 10:30 Overview of USB systems. USB CYPRESS product overview. Peripherals: Low Speed, Full Speed, High Speed (1.1 and 2.0). Hub Solutions, Embedded Host Solutions, On-The-Go (OTG) and wireless USB. USB Development Tools (first part) 10:30 -...

  1. Mini MAX - Medicaid Sample

    Data.gov (United States)

    U.S. Department of Health & Human Services — To facilitate wider use of MAX, CMS contracted with Mathematica to convene a technical expert panel (TEP) and determine the feasibility of creating a sample file for...

  2. Soil Gas Sampling

    Science.gov (United States)

    Field Branches Quality System and Technical Procedures: This document describes general and specific procedures, methods and considerations to be used and observed when collecting soil gas samples for field screening or laboratory analysis.

  3. Role of SiC substrate surface on local tarnishing of deposited silver mirror stacks

    Science.gov (United States)

    Limam, Emna; Maurice, Vincent; Seyeux, Antoine; Zanna, Sandrine; Klein, Lorena H.; Chauveau, Grégory; Grèzes-Besset, Catherine; Savin De Larclause, Isabelle; Marcus, Philippe

    2018-04-01

    The role of the SiC substrate surface on the resistance to the local initiation of tarnishing of thin-layered silver stacks for demanding space mirror applications was studied by combined surface and interface analysis on model stack samples deposited by cathodic magnetron sputtering and submitted to accelerated aging in gaseous H2S. It is shown that suppressing the surface pores resulting from the bulk SiC material production process by surface pretreatment eliminates the high aspect ratio surface sites that are imperfectly protected by the SiO2 overcoat after the deposition of silver. The formation of channels connecting the silver layer to its environment through the failing protection layer at the surface pores and locally enabling H2S entry and Ag2S growth as columns until emergence at the stack surface is suppressed, which markedly delays tarnishing initiation and thereby preserves the optical performance. The results revealed that residual tarnishing initiation proceeds by a mechanism essentially identical in nature but involving different pathways short circuiting the protection layer and enabling H2S ingress until the silver layer. These permeation pathways are suggested to be of microstructural origin and could correspond to the incompletely coalesced intergranular boundaries of the SiO2 layer.

  4. Porous Structures in Stacked, Crumpled and Pillared Graphene-Based 3D Materials.

    Science.gov (United States)

    Guo, Fei; Creighton, Megan; Chen, Yantao; Hurt, Robert; Külaots, Indrek

    2014-01-01

    Graphene, an atomically thin material with the theoretical surface area of 2600 m 2 g -1 , has great potential in the fields of catalysis, separation, and gas storage if properly assembled into functional 3D materials at large scale. In ideal non-interacting ensembles of non-porous multilayer graphene plates, the surface area can be adequately estimated using the simple geometric law ~ 2600 m 2 g -1 /N, where N is the number of graphene sheets per plate. Some processing operations, however, lead to secondary plate-plate stacking, folding, crumpling or pillaring, which give rise to more complex structures. Here we show that bulk samples of multilayer graphene plates stack in an irregular fashion that preserves the 2600/N surface area and creates regular slot-like pores with sizes that are multiples of the unit plate thickness. In contrast, graphene oxide deposits into films with massive area loss (2600 to 40 m 2 g -1 ) due to nearly perfect alignment and stacking during the drying process. Pillaring graphene oxide sheets by co-deposition of colloidal-phase particle-based spacers has the potential to partially restore the large monolayer surface. Surface areas as high as 1000 m 2 g -1 are demonstrated here through colloidal-phase deposition of graphene oxide with water-dispersible aryl-sulfonated ultrafine carbon black as a pillaring agent.

  5. Multiresolution imaging using golden angle stack-of-stars and compressed sensing for dynamic MR urography.

    Science.gov (United States)

    Pandey, Abhishek; Yoruk, Umit; Keerthivasan, Mahesh; Galons, Jean-Philippe; Sharma, Puneet; Johnson, Kevin; Martin, Diego R; Altbach, Maria I; Bilgin, Ali; Saranathan, Manojkumar

    2017-07-01

    To develop a novel multiresolution MRI methodology for accurate estimation of glomerular filtration rate (GFR) in vivo. A three-dimensional golden-angle radial stack-of-stars (SoS) trajectory was used for data acquisition on a 3 Tesla MRI scanner. Multiresolution reconstruction and analysis was performed using arterial input function reconstructed at 1-s. temporal resolution and renal dynamic data reconstructed using compressed sensing (CS) with 4-s temporal resolution. The method was first validated using simulations and the clinical utility of the technique was evaluated by comparing the GFR estimates from the proposed method to the estimated GFR (eGFR) obtained from serum creatinine for 10 subjects. The 4-s temporal resolution CS images minimized streaking artifacts and noise while the 1-s temporal resolution AIF minimized errors in GFR estimates. A paired t-test showed that there was no statistically significant difference between MRI based total GFR values and serum creatinine based eGFR estimates (P = 0.92). We have demonstrated the feasibility of multiresolution MRI using a golden angle radial stack-of-stars scheme to accurately estimate GFR as well as produce diagnostic quality dynamic images in vivo. 1 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2017;46:303-311. © 2017 International Society for Magnetic Resonance in Medicine.

  6. Local degradation analysis of a real long-term operated DMFC stack MEA

    Science.gov (United States)

    Hartmann, Peter; Gerteisen, Dietmar

    2012-12-01

    Understanding degradation of the membrane-electrode assembly (MEA) of direct methanol fuel cells (DMFC) is important technically and scientifically for the advancement of this technology. In this work, we carry out a spatially resolved investigation of the degradation of an MEA, which has been degraded through its operation lifetime. The MEA has an active area of 320 cm2 and has been used in operation of a DMFC stack for more than 3000 h to power a lift truck. The analysis of degradation with respect to the local position of the flow field pattern was carried out by cutting the MEA into small pieces that are characterized in a 1 cm2 sized test cell with a reference electrode setup. The characterization techniques involved measurement of anode and cathode polarization curves, electrode potential relaxation curves after current interruption, MeOH-stripping voltammograms, cyclic voltammetry and SEM/EDX analysis. The MEA pieces were prepared by Laser ablation technique to realize the reference electrodes. The analysis yielded an independence of performance from the local position of the MEAs within the stack in terms of the anode and cathode flow fields.

  7. Three-Dimensional Modeling of the Detonation of a Munitions Stack and the Loading on an Adjacent Stack Protected by a Water Barricade

    National Research Council Canada - National Science Library

    Lottero, Richard

    2001-01-01

    This report describes the results of three-dimensional (3-D) hydrocode computations modeling the detonation of a donor munitions stack and the loading on and response of a protective water barricade and a nearby acceptor munitions stack...

  8. Generalized diffraction-stack migration and filtering of coherent noise

    KAUST Repository

    Zhan, Ge

    2014-01-27

    We reformulate the equation of reverse-time migration so that it can be interpreted as summing data along a series of hyperbola-like curves, each one representing a different type of event such as a reflection or multiple. This is a generalization of the familiar diffraction-stack migration algorithm where the migration image at a point is computed by the sum of trace amplitudes along an appropriate hyperbola-like curve. Instead of summing along the curve associated with the primary reflection, the sum is over all scattering events and so this method is named generalized diffraction-stack migration. This formulation leads to filters that can be applied to the generalized diffraction-stack migration operator to mitigate coherent migration artefacts due to, e.g., crosstalk and aliasing. Results with both synthetic and field data show that generalized diffraction-stack migration images have fewer artefacts than those computed by the standard reverse-time migration algorithm. The main drawback is that generalized diffraction-stack migration is much more memory intensive and I/O limited than the standard reverse-time migration method. © 2014 European Association of Geoscientists & Engineers.

  9. Effect of flow parameters on flare stack generator noise

    International Nuclear Information System (INIS)

    Dinn, T.S.

    1998-01-01

    The SoundPLAN Computer Noise Model was used to determine the general effect of flare noise in a community adjacent to a petrochemical plant. Tests were conducted to determine the effect of process flow conditions and the pulsating flame on the flare stack generator noise from both a refinery flare and process flare. Flaring under normal plant operations, the flaring of fuel gas and the flaring of hydrogen were the three conditions that were tested. It was shown that the steam flow rate was the determining factor in the flare stack generated noise. Variations in the water seal level in the flare line surge tank increased or decreased the gas flowrate, which resulted in a pulsating flame. The period and amplitude of the pulsating noise from the flare stacks was determined by measuring several parameters. Flare stack noise oscillations were found to be greater for the process flare than for the refinery flare stack. It was suggested that minimizing the amount of steam fed to the flare and improving the burner design would minimize noise. 2 tabs., 6 figs

  10. Estimation of stacking fault and twin energies in transition metals

    International Nuclear Information System (INIS)

    Papon, Anne-Marie

    1979-01-01

    As twins and stacking faults play an important role in the plastic deformation of metals, the objective of this research thesis is, by using an as correct as possible description of band d state density, to assess the internal energy of twins and stacking faults in metals with a CFC, HC or CC crystal structure. If, in transition metals, cohesion mainly results from d electron attraction, other terms intervening in crystal equilibrium must also be taken into account. Thus, the author proposes a decomposition of cohesion energy. The geometry of twins and stacking faults in compact phases is defined, and energy calculations are presented and discussed. Alloying effects are then addressed, as well as a general comparison with available experimental results. After a geometric description of twins and stacking faults in CC structures, their energies are calculated for a Gaussian distribution of state density. For higher order moments, defect energy due to d orbital anisotropy is assessed, and then applied to energy and stability calculations in twins and stacking faults for various relaxed atomic configurations

  11. SHEDS-Dietary Technical Manual Appendices

    Science.gov (United States)

    The appendices for the SHEDS-Dietary Technical Manual include a sample food diary, backgorund information on the water concentration data used in SHEDS-Dietary, a food list, food definitions and sample code.

  12. A real-time stack radioactivity monitoring system and dose projection program

    Energy Technology Data Exchange (ETDEWEB)

    Hull, A.P.; Michael, P.A. [Brookhaven National Laboratory, Upton, NY (United States); Bernstein, H.J. [Bernstein & Sons, Bellport, NY (United States)

    1995-02-01

    At Brookhaven National Laboratory, a commercial Low- and High-Range Air Effluent Monitor has become operational at the 60 Mw (t) High Flux Beam Reactor. Its output data is combined with that from ground-level and elevated meteorological sensors to provide a real-time projection of the down-wind dose rates from noble gases and radioiodines released from the HFBR`s 100 m stack. The output of the monitor, and the meteorological sensors and the dose projections can be viewed at emergency response terminals located in the Reactor Control Room, its Technical Support Center and at the laboratory`s separately located Meteorological Station and Monitoring and Assessment Center.

  13. Numerical investigation of a novel burner to combust anode exhaust gases of SOFC stacks

    Directory of Open Access Journals (Sweden)

    Pianko-Oprych Paulina

    2017-09-01

    Full Text Available The aim of the present study was a numerical investigation of the efficiency of the combustion process of a novel concept burner under different operating conditions. The design of the burner was a part of the development process of a complete SOFC based system and a challenging combination of technical requirements to be fulfilled. A Computational Fluid Dynamics model of a non-premixed burner was used to simulate combustion of exhaust gases from the anode region of Solid Oxide Fuel Cell stacks. The species concentrations of the exhaust gases were compared with experimental data and a satisfactory agreement of the conversion of hydrocarbons was obtained. This validates the numerical methodology and also proves applicability of the developed approach that quantitatively characterized the interaction between the exhaust gases and burner geometry for proper combustion modelling. Thus, the proposed CFD approach can be safely used for further numerical optimisation of the burner design.

  14. Evaluation of the Split-H approach to modeling non-buoyant releases from vent stacks

    International Nuclear Information System (INIS)

    Ramsdell, J.V.

    1983-04-01

    Position C.2.b of Regulatory Guide 1.111 describes an approach to modeling the diffusion of effluents from roof top vents and short stacks using an elevated plume model under some conditions and using a ground-level source building wake model under other conditions. The approach is sometimes called a Split-H model. This report presents the results of an evaluation of the technical basis for and utility of the concept behind the Split-H model, outlines the devlopment of an upgraded model with those estimated using the Regulatory Guide Split-H model and a ground-level building wake model, and discusses alternatives to the Regulatory Guide position that the NRC may wish to consider. Concentration comparisons are made using model results for meteorological data from 18 nuclear power plant sites

  15. 49 CFR 178.815 - Stacking test.

    Science.gov (United States)

    2010-10-01

    ... comes in contact with the test sample. Compression must be applied end to end. The speed of the... a load suitable for dynamic compression testing. (e) Criteria for passing the test. (1) For metal... unsafe for transportation, and no loss of contents. (4) For the dynamic compression test, a container...

  16. 49 CFR 178.606 - Stacking test.

    Science.gov (United States)

    2010-10-01

    ... compression testing machine. The test must be conducted at room temperature on an empty, unsealed packaging... lowered until it comes in contact with the test sample. Compression must be applied end to end. The speed... to inner packagings likely to reduce safety in transportation. For the dynamic compression test, a...

  17. 49 CFR 178.980 - Stacking test.

    Science.gov (United States)

    2010-10-01

    ... contact with the test sample. Compression must be applied end to end. The speed of the compression tester... into a load suitable for dynamic compression testing. (e) Criterion for passing the test. (1) For metal.... (3) For the dynamic compression test, a container passes the test if, after application of the...

  18. TECHNICAL COORDINATION

    CERN Multimedia

    A. Ball and W. Zeuner

    2012-01-01

      UXC + detectors As explained in detail in the November 2011 bulletin, the bellows unit at −18.5 m from the CMS interaction point was identified as a prime candidate for the regularly occurring pressure spikes which occasionally led to sustained severe background conditions in 2011, affecting dead time and data quality. Similar regions in LHC with vacuum instabilities were observed to be close to bellows, which radiography showed to have distorted RF-fingers — on removal, they proved to have been severely overheated. The plans for the Year-End Technical Stop were adapted to prioritise radiography of the bellows at 16 m to 18 m either end of CMS. Excellent work by the beam pipe, survey and heavy mechanical teams allowed the X-rays to be taken as planned on 20th December, showing that the bellow at −18.5m had an obvious non-conformity. The RF-fingers were found inside the end of the opposing flared pipe instead of outside. In addition, the overlap between fingers and...

  19. TECHNICAL COORDINATION

    CERN Multimedia

    Austin Ball

    2013-01-01

      Since the last report, much visible progress has been made, as the LS1 programme approaches the halfway point. From early October, technical and safety shift-crew have been present around the clock, allowing detectors to stay switched on overnight, ensuring that safety systems are operational and instructions for non-expert shift-crew are clear. LS1 progress Throughout the summer, whilst the solenoid vacuum tank and YB0 surfaces were accessible, an extensive installation programme took place to prepare for Tracker colder operation and the PLT installation, in 2014, the Phase 1 Pixel Tracker installation, in 2016–’17, and the HCAL Phase 1 upgrade completion, ending in LS2. This included pipework for N2 or dry air to flush the Tracker bulkhead region, many sensors to monitor temperature and dew point in the Tracker and its service channels, heating wires outside the Tracker cooling bundles, supports for the new vacuum-jacketed, concentric, CO2 Pixel cooling lines, the PLT cool...

  20. Local Conduction in MoxW1–xSe2: The Role of Stacking Faults, Defects, and Alloying

    Science.gov (United States)

    2018-01-01

    Here, we report on the surface conductivity of WSe2 and MoxW1–xSe2 (0 ≤ x ≤ 1) crystals investigated with conductive atomic force microscopy. We found that stacking faults, defects, and chemical heterogeneities form distinct two-dimensional and one-dimensional conduction paths on the transition metal dichalcogenide surface. In the case of WSe2, in addition to step edges, we find a significant amount of stacking faults (formed during the cleaving process) that strongly influence the surface conductivity. These regions are attributed to the alternation of the 2H and 3R polytypism. The stacking faults form regular 2D patterns by alternation of the underlying stacking order, with a periodicity that varies significantly between different regions and samples. In the case of MoxW1–xSe2, its conductivity has a localized nature, which depends on the underlying chemical composition and the Mo/W ratio. Segregation to W-rich and Mo-rich regions during the growth process leads to nonuniform conduction paths on the surface of the alloy. We found a gradual change of the conductivity moving from one region to the other, reminiscent of lateral band bending. Our results demonstrate the use of C-AFM as a nanoscopic tool to probe the electrical properties of largely inhomogeneous samples and show the complicated nature of the surface conductivity of TMDC alloys. PMID:29578328

  1. Local Conduction in Mo xW1- xSe2: The Role of Stacking Faults, Defects, and Alloying.

    Science.gov (United States)

    Bampoulis, Pantelis; Sotthewes, Kai; Siekman, Martin H; Zandvliet, Harold J W

    2018-04-18

    Here, we report on the surface conductivity of WSe 2 and Mo x W 1- x Se 2 (0 ≤ x ≤ 1) crystals investigated with conductive atomic force microscopy. We found that stacking faults, defects, and chemical heterogeneities form distinct two-dimensional and one-dimensional conduction paths on the transition metal dichalcogenide surface. In the case of WSe 2 , in addition to step edges, we find a significant amount of stacking faults (formed during the cleaving process) that strongly influence the surface conductivity. These regions are attributed to the alternation of the 2H and 3R polytypism. The stacking faults form regular 2D patterns by alternation of the underlying stacking order, with a periodicity that varies significantly between different regions and samples. In the case of Mo x W 1- x Se 2 , its conductivity has a localized nature, which depends on the underlying chemical composition and the Mo/W ratio. Segregation to W-rich and Mo-rich regions during the growth process leads to nonuniform conduction paths on the surface of the alloy. We found a gradual change of the conductivity moving from one region to the other, reminiscent of lateral band bending. Our results demonstrate the use of C-AFM as a nanoscopic tool to probe the electrical properties of largely inhomogeneous samples and show the complicated nature of the surface conductivity of TMDC alloys.

  2. Communication: Thermodynamics of stacking disorder in ice nuclei

    Science.gov (United States)

    Quigley, D.

    2014-09-01

    A simple Ising-like model for the stacking thermodynamics of ice 1 is constructed for nuclei in supercooled water, and combined with classical nucleation theory. For relative stabilities of cubic and hexagonal ice I within the range of experimental estimates, this predicts critical nuclei are stacking disordered at strong sub-cooling, consistent with recent experiments. At higher temperatures nucleation of pure hexagonal ice is recovered. Lattice-switching Monte-Carlo is applied to accurately compute the relative stability of cubic and hexagonal ice for the popular mW model of water. Results demonstrate that this model fails to adequately capture the relative energetics of the two polytypes, leading to stacking disorder at all temperatures.

  3. Reliability assessment of germanium gate stacks with promising initial characteristics

    Science.gov (United States)

    Lu, Cimang; Lee, Choong Hyun; Nishimura, Tomonori; Nagashio, Kosuke; Toriumi, Akira

    2015-02-01

    This work reports on the reliability assessment of germanium (Ge) gate stacks with promising initial electrical properties, with focus on trap generation under a constant electric stress field (Estress). Initial Ge gate stack properties do not necessarily mean highly robust reliability when it is considered that traps are newly generated under high Estress. A small amount of yttrium- or scandium oxide-doped GeO2 (Y-GeO2 or Sc-GeO2, respectively) significantly reduces trap generation in Ge gate stacks without deterioration of the interface. This is explained by the increase in the average coordination number (Nav) of the modified GeO2 network that results from the doping.

  4. Edge-edge interactions in stacked graphene nanoplatelets

    Energy Technology Data Exchange (ETDEWEB)

    Cruz Silva, Eduardo [ORNL; Terrones Maldonado, Humberto [ORNL; Terrones Maldonado, Mauricio [ORNL; Jia, Xiaoting [Massachusetts Institute of Technology (MIT); Sumpter, Bobby G [ORNL; Dresselhaus, M [Massachusetts Institute of Technology (MIT); Meunier, V. [Rensselaer Polytechnic Institute (RPI)

    2013-01-01

    High-resolution transmission electron microscopy (HRTEM) studies show the dynamics of small graphene platelets on larger graphene layers. The platelets move nearly freely to eventually lock in at well-defined positions close to the edges of the larger underlying graphene sheet. While such movement is driven by a shallow potential energy surface described by an interplane interaction, the lock-in position occurs by via edge-edge interactions of the platelet and the graphene surface located underneath. Here we quantitatively study this behavior using van der Waals density functional calculations. Local interactions at the open edges are found to dictate stacking configurations that are different from Bernal (AB) stacking. These stacking configurations are known to be otherwise absent in edge-free two-dimensional (2D) graphene. The results explain the experimentally observed platelet dynamics and provide a detailed account of the new electronic properties of these combined systems.

  5. Magneto-optical properties of ABC-stacked trilayer graphene.

    Science.gov (United States)

    Lin, Yi-Ping; Lin, Chiun-Yan; Ho, Yen-Hung; Do, Thi-Nga; Lin, Ming-Fa

    2015-06-28

    The generalized tight-binding model is developed to investigate the magneto-optical absorption spectra of ABC-stacked trilayer graphene. The absorption peaks can be classified into nine categories of inter-Landau-level optical excitations, including three intra-group and six inter-group ones. Most of them belong to the twin-peak structures because of the asymmetric Landau level spectrum. The threshold absorption peak alone comes from a certain excitation channel, and its frequency is associated with a specific interlayer atomic interaction. The Landau-level anticrossings cause extra absorption peaks. Moreover, a simple relationship between the absorption frequency and the field strength is absent. The magneto-optical properties of ABC-stacked trilayer graphene are totally different from those of AAA- and ABA-stacked ones, such as the number, intensity and frequency of absorption peaks.

  6. Thermoacoustic design using stem of goose down stack

    Science.gov (United States)

    Farikhah, Irna; Ristanto, Sigit; Idrus, Hadiyati; Kaltsum, Ummi; Faisal, Affandi; Setiawan, Ihsan; Setio Utomo, Agung Bambang

    2012-09-01

    Many refrigerators using CFC as a refrigerant are seen as the cause of the depletion of ozone. Hence, thermoacoustic was chosen as an alternative refrigerator that safe for environment. There are many variable that influenced the optimization of thermoacoustic design. One of them is thermal conductivity of material of stack. The Stack material must have a low thermal conductivity. In this research we used organic stack made of stem of goose down. It has superior thermal insulating. It means that they have the lowest thermal conductivity. The system uses no refrigerant or compressor, and the only mechanical moving part is the loudspeaker connected to a signal generator that produces the acoustic. The working fluid is air and the material of resonator is stainless steel. A series test on the laboratory found that there is a decrease of 5°C in temperature for about 2 minutes.

  7. Electric toy vehicle powered by a PEMFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Beneito, Ruben; Vilaplana, Joaquin; Gisbert, Santiago [Technological Institute for Toy (AIJU), 03440 Ibi (Spain)

    2007-07-15

    The article describes the design and development of an electric toy vehicle powered by a fuel cell stack. The system consisted of a 150 W PEMFC stack powered by hydrogen/air, a tank of metal hydrides of AB (TiFe) alloy type with a capacity of 300 standard litres, for storing hydrogen, and an electronic power device based on electrolytic capacitors, to supply peak power demands during acceleration and start up of the vehicle. The air supply was provided by a fan preceded by a filter, and in a similar manner the stack was cooled by an air ventilation system. An electrovalve was used to supply H{sub 2} in dead-ended mode. All the components were integrated in the vehicle, and the prototype was tested in real working conditions, in a test bench and by children. (author)

  8. Piezoelectric stack actuator parameter extraction with hysteresis compensation

    DEFF Research Database (Denmark)

    Zsurzsan, Tiberiu-Gabriel; Mangeot, Charles; Andersen, Michael A. E.

    2014-01-01

    The Piezoelectric Actuator Drive (PAD) is a type of rotary motor that transforms the linear motion of piezoelectric stack actuators into a precise rotational motion. The very high stiffness of the actuators employed make this type of motor suited for open-loop control, but the inherent hysteresis...... exhibited by piezoelectric ceramics causes losses. Therefore, this paper presents a straightforward method to measure piezoelectric stack actuator equiv- alent parameters that includes nonlinearities. By folding the nonlinearities into a newly-defined cou- pling coefficient, the inherent hysteretic behavior...... of piezoelectric stack actuators can be greatly reduced through precompensation. Experimental results show a fitting accuracy of 98.8 % between the model and measurements and a peak absolute error reduction by a factor of 10 compared to the manufacturer- provided parameter. This method improves both the static...

  9. Salt Concentration Differences Alter Membrane Resistance in Reverse Electrodialysis Stacks

    KAUST Repository

    Geise, Geoffrey M.

    2014-01-14

    Membrane ionic resistance is usually measured by immersing the membrane in a salt solution at a single, fixed concentration. While salt concentration is known to affect membrane resistance when the same concentration is used on both sides of the membrane, little is known about membrane resistance when the membrane is placed between solutions of different concentrations, such as in a reverse electrodialysis (RED) stack. Ionic resistance measurements obtained using Selemion CMV and AMV that separated sodium chloride and ammonium bicarbonate solutions of different concentrations were greater than those measured using only the high-concentration solution. Measured RED stack resistances showed good agreement with resistances calculated using an equivalent series resistance model, where the membranes accounted for 46% of the total stack resistance. The high area resistance of the membranes separating different salt concentration solutions has implications for modeling and optimizing membranes used in RED systems.

  10. Continued SOFC cell and stack technology and improved production methods

    Energy Technology Data Exchange (ETDEWEB)

    Wandel, M.; Brodersen, K.; Phair, J. (and others)

    2009-05-15

    Within this project significant results are obtained on a number of very diverse areas ranging from development of cell production, metallic creep in interconnect to assembling and test of stacks with foot print larger than 500 cm2. Out of 38 milestones 28 have been fulfilled and 10 have been partly fulfilled. This project has focused on three main areas: 1) The continued cell development and optimization of manufacturing processes aiming at production of large foot-print cells, improving cell performance and development environmentally more benign production methods. 2) Stack technology - especially stacks with large foot print and improving the stack design with respect to flow geometry and gas leakages. 3) Development of stack components with emphasis on sealing (for 2G as well as 3G), interconnect (coat, architecture and creep) and test development. Production of cells with a foot print larger than 500 cm2 is very difficult due to the brittleness of the cells and great effort has been put into this topic. Eight cells were successfully produced making it possible to assemble and test a real stack thereby giving valuable results on the prospects of stacks with large foot print. However, the yield rate is very low and a significant development to increase this yield lies ahead. Several lessons were learned on the stack level regarding 'large foot print' stacks. Modelling studies showed that the width of the cell primarily is limited by production and handling of the cell whereas the length (in the flow direction) is limited by e.g. pressure drop and necessary manifolding. The optimal cell size in the flow direction was calculated to be between approx20 cm and < 30 cm. From an economical point of view the production yield is crucial and stacks with large foot print cell area are only feasible if the cell production yield is significantly enhanced. Co-casting has been pursued as a production technique due to the possibilities in large scale production

  11. Electrically Conductive and Protective Coating for Planar SOFC Stacks

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jung-Pyung; Stevenson, Jeffry W.

    2017-12-04

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

  12. Multipole Stack for the 800 MeV PS Booster

    CERN Multimedia

    1975-01-01

    The 800 MeV PS Booster had seen first beam in its 4 superposed rings in 1972, routine operation began in 1973. In the strive for ever higher beam intensities, the need for additional multipole lenses became evident. After detailed studies, the manufacture of 8 stacks of multipoles was launched in 1974. Each stack consists of 4 superposed multipoles and each multipole has 4 concentric shells. From the innermost to the outermost shell, Type A contains octupole, skew-octupole, sextupole, skew-sextupole. Type B contains skew-octupole, skew-sextupole, vertical dipole, horizontal dipole. Completion of installation in 1976 opened the way to higher beam intensities. M. Battiaz is seen here with a multipole stack and its many electrical connections.

  13. Technical innovation and management

    International Nuclear Information System (INIS)

    Yoon, Yang Cheol

    1982-08-01

    This book gives explanations of the conception of technical innovation, development plan in Korea, connection between technology and a growth factor in national income, problem of technical innovation in developing country, analysis on cooperation between a developed country and a developing country, evaluation and strategy of technical development in Korea, technical innovation of industry, management of technical industry, analysis of special condition in Korea.

  14. Impact of Global Economic Crisis on Technical and Vocational ...

    African Journals Online (AJOL)

    The study examined the relationship between global economic crisis (GEC) and inadequacy of facilities for administration of the Technical and. Vocational Education. The descriptive survey design with a random sample of 100 technical teachers from a population of 139 technical teachers in all six Technical Colleges in ...

  15. Nuclear fuel rod with retainer for pellet stack

    International Nuclear Information System (INIS)

    Cloue, J.M.

    1986-01-01

    The rod, usable in pressurized water reactors, comprises a stack of fuel pellets and means holding the stack against an end plug of the fuel can during handling operations. These means include a radially expansive element (retainer) of which the shape is so that when it is free at ambient temperature it is gripping the inside of the casing, and a temperature sensitive spacer which contracts the retainer to release it from the casing at a temperature between the ambient and the operating temperature of a reactor [fr

  16. Implementing cloud storage with OpenStack Swift

    CERN Document Server

    Rajana, Kris; Varma, Sreedhar

    2014-01-01

    This tutorial-based book has a step-by-step approach for each topic, ensuring it is thoroughly covered and easy to follow. If you are an IT administrator who wants to enter the world of cloud storage using OpenStack Swift, then this book is ideal for you. Whether your job is to build, manage, or use OpenStack Swift, this book is an ideal way to move your career ahead. Only basic Linux and server technology skills are expected, to take advantage of this book.

  17. Exact Solutions to the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann; Archetti, Claudia; Madsen, Oli B.G.

    In the Double Travelling Salesman Problem with Multiple Stacks (DTSPMS) a set of orders is given, each one requiring transportation of one item from a customer in a pickup region to a customer in a delivery region. The vehicle available for the transportation in each region carries a container......, which is organised in rows of given length. Each row is handled independently from the others according to a LIFO stack policy. The DTSPMS consists in determining the pickup tour, the loading plan of the container and the delivery tour in such a way that the total length of the two tours is minimised...

  18. Hardware Evaluation of the Horizontal Exercise Fixture with Weight Stack

    Science.gov (United States)

    Newby, Nate; Leach, Mark; Fincke, Renita; Sharp, Carwyn

    2009-01-01

    HEF with weight stack seems to be a very sturdy and reliable exercise device that should function well in a bed rest training setting. A few improvements should be made to both the hardware and software to improve usage efficiency, but largely, this evaluation has demonstrated HEF's robustness. The hardware offers loading to muscles, bones, and joints, potentially sufficient to mitigate the loss of muscle mass and bone mineral density during long-duration bed rest campaigns. With some minor modifications, the HEF with weight stack equipment provides the best currently available means of performing squat, heel raise, prone row, bench press, and hip flexion/extension exercise in a supine orientation.

  19. Experimental 1 kW 20 cell PEFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, F.N.; Marmy, C.A.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ruge, M. [Swiss Federal Inst. of Technology (ETH), Zuerich (Switzerland)

    1999-08-01

    A 20-cell PEFC stack was designed and built. Resin impregnated graphite was used as bipolar plate material. The air cooling of the stack was optimized by introducing high surface structures into the open space of the cooling plates. At {eta} (H{sub 2} LHV) = 0.5 a power of 880 W was obtained under conditions of low gas-pressures of 1.15 bar{sub a}. The auxiliary power for process air supply and cooling at 880 W power is less than 7% of the power output, indicating that the described system may be operated at a high efficiency. (author) 5 figs., 2 refs.

  20. Second Generation Small Pixel Technology Using Hybrid Bond Stacking

    Science.gov (United States)

    Venezia, Vincent C.; Hsiung, Alan Chih-Wei; Yang, Wu-Zang; Zhang, Yuying; Zhao, Cheng; Lin, Zhiqiang; Grant, Lindsay A.

    2018-01-01

    In this work, OmniVision’s second generation (Gen2) of small-pixel BSI stacking technologies is reviewed. The key features of this technology are hybrid-bond stacking, deeper back-side, deep-trench isolation, new back-side composite metal-oxide grid, and improved gate oxide quality. This Gen2 technology achieves state-of-the-art low-light image-sensor performance for 1.1, 1.0, and 0.9 µm pixel products. Additional improvements on this technology include less than 100 ppm white-pixel process and a high near-infrared (NIR) QE technology. PMID:29495272

  1. Second Generation Small Pixel Technology Using Hybrid Bond Stacking

    OpenAIRE

    Vincent C. Venezia; Alan Chih-Wei Hsiung; Wu-Zang Yang; Yuying Zhang; Cheng Zhao; Zhiqiang Lin; Lindsay A. Grant

    2018-01-01

    In this work, OmniVision’s second generation (Gen2) of small-pixel BSI stacking technologies is reviewed. The key features of this technology are hybrid-bond stacking, deeper back-side, deep-trench isolation, new back-side composite metal-oxide grid, and improved gate oxide quality. This Gen2 technology achieves state-of-the-art low-light image-sensor performance for 1.1, 1.0, and 0.9 µm pixel products. Additional improvements on this technology include less than 100 ppm white-pixel process a...

  2. Second Generation Small Pixel Technology Using Hybrid Bond Stacking

    Directory of Open Access Journals (Sweden)

    Vincent C. Venezia

    2018-02-01

    Full Text Available In this work, OmniVision’s second generation (Gen2 of small-pixel BSI stacking technologies is reviewed. The key features of this technology are hybrid-bond stacking, deeper back-side, deep-trench isolation, new back-side composite metal-oxide grid, and improved gate oxide quality. This Gen2 technology achieves state-of-the-art low-light image-sensor performance for 1.1, 1.0, and 0.9 µm pixel products. Additional improvements on this technology include less than 100 ppm white-pixel process and a high near-infrared (NIR QE technology.

  3. Second Generation Small Pixel Technology Using Hybrid Bond Stacking.

    Science.gov (United States)

    Venezia, Vincent C; Hsiung, Alan Chih-Wei; Yang, Wu-Zang; Zhang, Yuying; Zhao, Cheng; Lin, Zhiqiang; Grant, Lindsay A

    2018-02-24

    In this work, OmniVision's second generation (Gen2) of small-pixel BSI stacking technologies is reviewed. The key features of this technology are hybrid-bond stacking, deeper back-side, deep-trench isolation, new back-side composite metal-oxide grid, and improved gate oxide quality. This Gen2 technology achieves state-of-the-art low-light image-sensor performance for 1.1, 1.0, and 0.9 µm pixel products. Additional improvements on this technology include less than 100 ppm white-pixel process and a high near-infrared (NIR) QE technology.

  4. Band engineering in transition metal dichalcogenides: Stacked versus lateral heterostructures

    International Nuclear Information System (INIS)

    Guo, Yuzheng; Robertson, John

    2016-01-01

    We calculate a large difference in the band alignments for transition metal dichalcogenide (TMD) heterojunctions when arranged in the stacked layer or lateral (in-plane) geometries, using direct supercell calculations. The stacked case follows the unpinned limit of the electron affinity rule, whereas the lateral geometry follows the strongly pinned limit of alignment of charge neutrality levels. TMDs therefore provide one of the few clear tests of band alignment models, whereas three-dimensional semiconductors give less stringent tests because of accidental chemical trends in their properties.

  5. Simulation of Collective Excitations in Long Josephson Junction Stacks

    Science.gov (United States)

    Rahmonov, Ilhom; Shukrinov, Yury; Atanasova, Pavlina; Zemlyanaya, Elena; Streltsova, Oksana; Zuev, Maxim; Plecenik, Andrej; Irie, Akinobu

    2018-02-01

    The phase dynamics of a stack of long Josephson junctions has been studied. Both inductive and capacitive couplings between Josephson junctions have been taken into account in the calculations. The IV-curve, the dependence on the bias current of the radiation power and dynamics of each JJs of the stack have been investigated. The coexistence of the charge traveling wave and fluxon states has been observed. This state can be considered as a new collective excitation in the system of coupled Josephson junctions. We demonstrate that the observed collective excitation leads to the decrease of radiation power from the system.

  6. Spectrally tunable linear polarization rotation using stacked metallic metamaterials

    Science.gov (United States)

    Romain, Xavier; Baida, Fadi I.; Boyer, Philippe

    2017-08-01

    We make a theoretical study of the transmission properties of a stack of metallic metamaterials and show that is able to achieve a perfect transmission selectively exhibiting broadband (Q {10}5) polarization rotation. We especially highlight how the arrangement of the stacked structure, as well as the metamaterial unit cell geometry, has a large influence on transmission in the spectral domain. For this purpose, we use an extended analytical Jones formalism that allows us to obtain a rigorous and analytical expression of the transmission. Such versatile structures could find potential applications in polarimetry or in the control of light polarization for THz waves.

  7. From the components to the stack. Developing and designing 5kW HT-PEFC stacks; Von der Komponente zum Stack. Entwicklung und Auslegung von HT-PEFC-Stacks der 5 kW-Klasse

    Energy Technology Data Exchange (ETDEWEB)

    Bendzulla, Anne

    2010-12-22

    The aim of the present project is to develop a stack design for a 5-kW HTPEFC system. First, the state of the art of potential materials and process designs will be discussed for each component. Then, using this as a basis, three potential stack designs with typical attributes will be developed and assessed in terms of practicality with the aid of a specially derived evaluation method. Two stack designs classified as promising will be discussed in detail, constructed and then characterized using short stack tests. Comparing the stack designs reveals that both designs are fundamentally suitable for application in a HT-PEFC system with on-board supply. However, some of the performance data differ significantly for the two stack designs. The preferred stack design for application in a HT-PEFC system is characterized by robust operating behaviour and reproducible high-level performance data. Moreover, in compact constructions (120 W/l at 60 W/kg), the stack design allows flexible cooling with thermal oil or air, which can be adapted to suit specific applications. Furthermore, a defined temperature gradient can be set during operation, allowing the CO tolerance to be increased by up to 10 mV. The short stack design developed within the scope of the present work therefore represents an ideal basis for developing a 5-kW HT-PEFC system. Topics for further research activities include improving the performance by reducing weight and/or volume, as well as optimizing the heat management. The results achieved within the framework of this work clearly show that HTPEFC stacks have the potential to play a decisive role in increasing efficiency in the future, particularly when combined with an on-board supply system. (orig.) [German] Ziel der vorliegenden Arbeit ist die Entwicklung eines Stackkonzeptes fuer ein 5 kW-HT-PEFC System. Dazu wird zunaechst fuer jede Komponente der Stand der Technik moeglicher Materialien und Prozesskonzepte diskutiert. Darauf aufbauend werden drei

  8. Potential radionuclide emissions from stacks on the Hanford site, Part 2: Dose assessment methodology using portable low-resolution gamma spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, J.M. [Westinghouse Hanford Company, Richland, WA (United States)

    1995-02-01

    In September 1992, the Westinghouse Hanford Company began developing an in situ measurement method to assess gamma radiation emanating from high-efficiency particulate air filters using portable low-resolution gamma spectroscopy. The purpose of the new method was to assess radioactive exhaust stack air emissions from empirical data rather than from theoretical models and to determine the potential unabated dose to an offsite theoretical maximally exposed individual. In accordance with Title 40, Code of Federal Regulations, Part 61, Subpart H, {open_quotes}National Emission Standards for Hazardous Air Pollutants{close_quotes}, stacks that have the potential to emit {ge} 1 {mu}Sv y{sup {minus}1} (0.1 mrem y{sup {minus}1}) to the maximally exposed individual are considered {open_quotes}major{close_quotes} and must meet the continuous monitoring requirements. After the method was tested and verified, the U.S. Environmental Protection Agency, Region 10, approved its use in June 1993. Of the 125 stacks operated by the Westinghouse Hanford Company, 22 were targeted for evaluation by this method, and 15 were assessed. (The method could not be applied at seven stacks because of excessive background radiation or because no gamma emitting particles appear in the emission stream.) The most significant result from this study was the redesignation of the T Plant main stack. The stack was assessed as being {open_quotes}minor{close_quotes}, and it now only requires periodic confirmatory measurements and meets federally imposed sampling requirements.

  9. Extensive radioactive characterization of a phosphogypsum stack in SW Spain: {sup 226}Ra, {sup 238}U, {sup 210}Po concentrations and {sup 222}Rn exhalation rate

    Energy Technology Data Exchange (ETDEWEB)

    Abril, Jose-Maria, E-mail: jmabril@us.es [Dpto. Fisica Aplicada I, Universidad de Sevilla, EUITA, Ctra Utrera Km 1, 41013 Seville (Spain); Garcia-Tenorio, Rafael, E-mail: gtenorio@us.es [Dpto. Fisica Aplicada II, Universidad de Sevilla, ETSA, Avda. Reina Mercedes s/n, 41012 Seville (Spain); Manjon, Guillermo, E-mail: manjon@us.es [Dpto. Fisica Aplicada II, Universidad de Sevilla, ETSA, Avda. Reina Mercedes s/n, 41012 Seville (Spain)

    2009-05-30

    Phosphogypsum (PG) is a by-product of the phosphate fertilizer industries that contains relatively high concentrations of uranium series radionuclides. The US-EPA regulates the agriculture use of PG, attending to its {sup 226}Ra content and to the {sup 222}Rn exhalation rate from inactive stacks. Measurements of {sup 222}Rn exhalation rates in PG stacks typically show a large and still poorly understood spatial and temporal variability, and the published data are scarce. This work studies an inactive PG stack in SW Spain of about 0.5 km{sup 2} from where PG can be extracted for agriculture uses, and an agriculture soil 75 km apart, being representative of the farms to be amended with PG. Activity concentrations of {sup 226}Ra, {sup 238}U and {sup 210}Po have been measured in 30 PG samples (0-90 cm horizon) allowing for the construction of maps with spatial distributions in the PG stack and for the characterization of the associated PG inputs to agriculture soils. Averaged {sup 226}Ra concentrations for the stack were 730 {+-} 60 Bq kg{sup -1} (d.w.), over the US-EPA limit of 370 Bq kg{sup -1}. {sup 222}Rn exhalation rate has been measured by the charcoal canister method in 49 sampling points with 3 canisters per sampling point. Values in PG stack were under the US-EPA limit of 2600 Bq m{sup -2} h{sup -1}, but they were one order of magnitude higher than those found in the agriculture soil. Variability in radon emissions has been studied at different spatial scales. Radon exhalation rates were correlated with {sup 226}Ra concentrations and daily potential evapotranspiration (ETo). They increased with ETo in agriculture soils, but showed an opposite behaviour in the PG stack.

  10. An Exact Method for the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Larsen, Jesper; Lusby, Richard Martin; Ehrgott, Matthias

    The double travelling salesman problem with multiple stacks (DTSPMS) is a pickup and delivery problem in which all pickups must be completed before any deliveries can be made. The problem originates from a real-life application where a 40 foot container (configured as 3 columns of 11 rows) is used...

  11. An Exact Method for the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Lusby, Richard Martin; Larsen, Jesper; Ehrgott, Matthias

    2010-01-01

    The double travelling salesman problem with multiple stacks (DTSPMS) is a pickup and delivery problem in which all pickups must be completed before any deliveries can be made. The problem originates from a real-life application where a 40 foot container (configured as 3 columns of 11 rows) is used...

  12. Hydrothermal synthesis and photoluminescent properties of stacked indium sulfide superstructures.

    Science.gov (United States)

    Xing, Yan; Zhang, Hongjie; Song, Shuyan; Feng, Jing; Lei, Yongqian; Zhao, Lijun; Li, Meiye

    2008-03-28

    Unusual hierarchical stacked superstructures of cubic beta-In2S3 were fabricated via a facile hydrothermal process in the presence of a surfactant cetyltrimethylammonium bromide CTAB; the 3D superstructures were developed by helical propagation of surface steps from microflakes of 10-20 nm thickness.

  13. Phase locked fluxon-antifluxon states in stacked Josephson junctions

    DEFF Research Database (Denmark)

    Carapella, Giovanni; Constabile, Giovanni; Petraglia, Antonio

    1996-01-01

    Measurements were made on a two-stack long Josephson junction with very similar parameters and electrical access to the thin middle electrode. Mutually phase-locked fluxon-antifluxon states were observed. The observed propagation velocity is in agreement with the theoretical prediction. The I-V c...... in the junctions coexist with fluxons. (C) 1996 American Institute of Physics....

  14. Compactifications of reductive groups as moduli stacks of bundles

    DEFF Research Database (Denmark)

    Martens, Johan; Thaddeus, Michael

    Let G be a reductive group. We introduce the moduli problem of "bundle chains" parametrizing framed principal G-bundles on chains of lines. Any fan supported in a Weyl chamber determines a stability condition on bundle chains. Its moduli stack provides an equivariant toroidal compactification of G...

  15. Rhythmic ring–ring stacking drives the circadian oscillator clockwise

    Science.gov (United States)

    Chang, Yong-Gang; Tseng, Roger; Kuo, Nai-Wei; LiWang, Andy

    2012-01-01

    The oscillator of the circadian clock of cyanobacteria is composed of three proteins, KaiA, KaiB, and KaiC, which together generate a self-sustained ∼24-h rhythm of phosphorylation of KaiC. The mechanism propelling this oscillator has remained elusive, however. We show that stacking interactions between the CI and CII rings of KaiC drive the transition from the phosphorylation-specific KaiC–KaiA interaction to the dephosphorylation-specific KaiC–KaiB interaction. We have identified the KaiB-binding site, which is on the CI domain. This site is hidden when CI domains are associated as a hexameric ring. However, stacking of the CI and CII rings exposes the KaiB-binding site. Because the clock output protein SasA also binds to CI and competes with KaiB for binding, ring stacking likely regulates clock output. We demonstrate that ADP can expose the KaiB-binding site in the absence of ring stacking, providing an explanation for how it can reset the clock. PMID:22967510

  16. Rhythmic ring-ring stacking drives the circadian oscillator clockwise.

    Science.gov (United States)

    Chang, Yong-Gang; Tseng, Roger; Kuo, Nai-Wei; LiWang, Andy

    2012-10-16

    The oscillator of the circadian clock of cyanobacteria is composed of three proteins, KaiA, KaiB, and KaiC, which together generate a self-sustained ∼24-h rhythm of phosphorylation of KaiC. The mechanism propelling this oscillator has remained elusive, however. We show that stacking interactions between the CI and CII rings of KaiC drive the transition from the phosphorylation-specific KaiC-KaiA interaction to the dephosphorylation-specific KaiC-KaiB interaction. We have identified the KaiB-binding site, which is on the CI domain. This site is hidden when CI domains are associated as a hexameric ring. However, stacking of the CI and CII rings exposes the KaiB-binding site. Because the clock output protein SasA also binds to CI and competes with KaiB for binding, ring stacking likely regulates clock output. We demonstrate that ADP can expose the KaiB-binding site in the absence of ring stacking, providing an explanation for how it can reset the clock.

  17. Revisiting the Fundamentals and Capabilities of the Stack Compression Test

    DEFF Research Database (Denmark)

    Alves, L.M.; Nielsen, Chris Valentin; Martin, P.A.F.

    2011-01-01

    performance by comparing the flow curves obtained from its utilisation with those determined by means of compressive testing carried out on solid cylinder specimens of the same material. Results show that mechanical testing of materials by means of the stack compression test is capable of meeting...... the increasing demand of accurate and reliable flow curves for sheet metals....

  18. Tunable infrared plasmonic devices using graphene/insulator stacks

    Science.gov (United States)

    Yan, Hugen; Li, Xuesong; Chandra, Bhupesh; Tulevski, George; Wu, Yanqing; Freitag, Marcus; Zhu, Wenjuan; Avouris, Phaedon; Xia, Fengnian

    2012-05-01

    The collective oscillation of carriers--the plasmon--in graphene has many desirable properties, including tunability and low loss. However, in single-layer graphene, the dependence on carrier concentration of both the plasmonic resonance frequency and magnitude is relatively weak, limiting its applications in photonics. Here, we demonstrate transparent photonic devices based on graphene/insulator stacks, which are formed by depositing alternating wafer-scale graphene sheets and thin insulating layers, then patterning them together into photonic-crystal-like structures. We show experimentally that the plasmon in such stacks is unambiguously non-classical. Compared with doping in single-layer graphene, distributing carriers into multiple graphene layers effectively enhances the plasmonic resonance frequency and magnitude, which is different from the effect in a conventional semiconductor superlattice and is a direct consequence of the unique carrier density scaling law of the plasmonic resonance of Dirac fermions. Using patterned graphene/insulator stacks, we demonstrate widely tunable far-infrared notch filters with 8.2 dB rejection ratios and terahertz linear polarizers with 9.5 dB extinction ratios. An unpatterned stack consisting of five graphene layers shields 97.5% of electromagnetic radiation at frequencies below 1.2 THz. This work could lead to the development of transparent mid- and far-infrared photonic devices such as detectors, modulators and three-dimensional metamaterial systems.

  19. Stacked-Bloch-wave electron diffraction simulations using GPU acceleration

    International Nuclear Information System (INIS)

    Pennington, Robert S.; Wang, Feng; Koch, Christoph T.

    2014-01-01

    In this paper, we discuss the advantages for Bloch-wave simulations performed using graphics processing units (GPUs), based on approximating the matrix exponential directly instead of performing a matrix diagonalization. Our direct matrix-exponential algorithm yields a functionally identical electron scattering matrix to that generated with matrix diagonalization. Using the matrix-exponential scaling-and-squaring method with a Padé approximation, direct GPU-based matrix-exponential double-precision calculations are up to 20× faster than CPU-based calculations and up to approximately 70× faster than matrix diagonalization. We compare precision and runtime of scaling and squaring methods with either the Padé approximation or a Taylor expansion. We also discuss the stacked-Bloch-wave method, and show that our stacked-Bloch-wave implementation yields the same electron scattering matrix as traditional Bloch-wave matrix diagonalization. - Highlights: • Bloch-wave and stacked-Bloch-wave calculations can be accelerated with GPUs. • Direct approximation of the matrix exponential can be faster than diagonalization. • GPU-based direct approximation can be ≈70× faster than CPU diagonalization. • Larger matrices benefit more from this approach than smaller ones. • Stacked-Bloch-wave scattering results are functionally identical to diagonalization

  20. Do Identical Polar Diatomic Molecules Form Stacked or Linear ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 8. Do Identical Polar Diatomic Molecules Form Stacked or Linear Dimers?: Hydrogen Bonding is Not Just Dipole-Dipole Interactions. C W Williams Richard N Zare E Arunan. General Article Volume 19 Issue 8 August 2014 pp 704-712 ...

  1. 7. Data Structures: Lists, Queues, Stacks and Arrays

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 6. Algorithms - Data Structures: Lists, Queues, Stacks and Arrays. R K Shyamasundar ... Author Affiliations. R K Shyamasundar1. Computer Science Group, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India ...

  2. Seismic fragility of ventilation stack of nuclear power plant

    International Nuclear Information System (INIS)

    Nefedov, S.S.; Yugai, T.Z.; Kalinkin, I.V.; Vizir, P.L.

    2003-01-01

    Fragility study of safety related elements is necessary step in seismic PSA of nuclear power plant (NPP). In present work fragility was analyzed after the example of the ventilation stack of NPP. Ventilation stack, considered in present work, is a separately erected construction with height of 100 m made of cast-in-place reinforced concrete. In accordance with IAEA terminology fragility of element is defined as conditional probability of its failure at given level of seismic loading. Failure of a ventilation stack was considered as development of the plastic hinge in some section of a shaft. Seismic ground acceleration a, which corresponds to failure, could be defined as limit seismic acceleration of ventilation stack [a]. Limit seismic acceleration [a] was considered as random value. Sources of its variation are connected with stochastic nature of factors determining it (properties of construction materials, soils etc.), and also with uncertainties of existing analytical techniques. Random value [a] was assumed to be distributed lognormally. Median m[a] and logarithmically standard deviation β of this distribution were defined by 'scaling method' developed by R.P. Kennedy et al. Using this values fragility curves were plotted for different levels of confidence probability. (author)

  3. Thermal entrance effects in a thermoacoustic stacked screen regenerator

    NARCIS (Netherlands)

    Bühler, Simon; wilcox, D; Oosterhuis, Joris; van der Meer, Theodorus H.

    2014-01-01

    Thermoacoustic cryocoolers are of raising interest because they are cost effective and reliable. The underlying heat pumping process occurs in the regenerator, where a sound wave interacts with a solid matrix material. Stacked screens are frequently used to build regenerators for thermoacoustic

  4. Proposal of stack Effect technology for predicted future years

    Science.gov (United States)

    Teddy Badai Samodra, FX; Adi Indrawan, Iwan

    2017-12-01

    Recently, stack effect is a general problem solver in providing vertical ventilation for urban environmental issues. However, study on resilient technology of stack effect for future years as predicted by climate trend should be conducted. Therefore, this research proposes a design of new technology on operable and adaptable vertical ventilation to the environmental change. The research method is conducted by comprehensive simulation of Ecotect Analysis, ANSYS Fluent and Matlab. Urban environment of Surabaya, as the research location, is the representative of tropical region. The results showed that the stack effect height and area could be modified instantly adjusting the environmental condition time by time in the future years. With 1.8 m of stack width, the proposed technology could capture 40 m3 of vertical air flow which is useful for physiological cooling and its dimension could be modified depending on the environmental condition. By providing resilient technology, predictable and sustainable ventilation method is offered to anticipate an unpredicted global warming and environmental change.

  5. Multipole stack for the 4 rings of the PS Booster

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    The PS Booster (originally 800 MeV, now 1.4 GeV) saw first beam in 1972, routine operation began in 1973. The strive for ever higher intensities required the addition of multipoles. Manufacture of 8 stacks of multipoles was launched in 1974, for installation in 1976. For details, see 7511120X.

  6. Consolidation process model for film stacking glass/PPS laminates

    NARCIS (Netherlands)

    Grouve, Wouter Johannes Bernardus; Akkerman, Remko

    2010-01-01

    A model is proposed to optimise the processing parameters for the consolidation of glass/polyphenylene sulphide (PPS) laminates using a film stacking procedure. In a split approach, the heating and consolidation phase are treated separately. The heating phase is modelled using the one-dimensional

  7. 7. Data Structures: Lists, Queues, Stacks and Arrays

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 6. Algorithms - Data Structures: Lists, Queues, Stacks and Arrays. R K Shyamasundar. Series Article Volume 2 Issue 6 June 1997 pp 39-46. Fulltext. Click here to view fulltext PDF. Permanent link:

  8. Calculating the output distribution of stack filters that are erosion ...

    African Journals Online (AJOL)

    Two procedures to compute the output distribution ϕs of certain stack filters S (so called erosion-dilation cascades) are given. One rests on the disjunctive normal form of S and also yields the rank selection probabilities. The other is based on inclusion-exclusion and e.g. yields ϕs for some important LULU-operators S.

  9. Precise stacking and bonding technology for RDDS structure

    International Nuclear Information System (INIS)

    Higo, T; Toge, N.; Suzuki, T.

    2000-01-01

    The X-band accelerating structures called RDDS1 (Rounded Dumped Detuned Structure) for the linear collider have been developed. The main body of RDDS1 was successfully fabricated in Japan (KEK, IHI). We established basic fabrication techniques through the development of prototype structures including RDDS1. The precise stacking and bonding technologies for RDDS structure are presented in this paper. (author)

  10. Surface passivation and optical characterization of Al2O3/a-SiCx stacks on c-Si substrates.

    Science.gov (United States)

    López, Gema; Ortega, Pablo R; Voz, Cristóbal; Martín, Isidro; Colina, Mónica; Morales, Anna B; Orpella, Albert; Alcubilla, Ramón

    2013-01-01

    The aim of this work is to study the surface passivation of aluminum oxide/amorphous silicon carbide (Al2O3/a-SiCx) stacks on both p-type and n-type crystalline silicon (c-Si) substrates as well as the optical characterization of these stacks. Al2O3 films of different thicknesses were deposited by thermal atomic layer deposition (ALD) at 200 °C and were complemented with a layer of a-SiCx deposited by plasma-enhanced chemical vapor deposition (PECVD) to form anti-reflection coating (ARC) stacks with a total thickness of 75 nm. A comparative study has been carried out on polished and randomly textured wafers. We have experimentally determined the optimum thickness of the stack for photovoltaic applications by minimizing the reflection losses over a wide wavelength range (300-1200 nm) without compromising the outstanding passivation properties of the Al2O3 films. The upper limit of the surface recombination velocity (S eff,max) was evaluated at a carrier injection level corresponding to 1-sun illumination, which led to values below 10 cm/s. Reflectance values below 2% were measured on textured samples over the wavelength range of 450-1000 nm.

  11. Development and Applications of a Stage Stacking Procedure

    Science.gov (United States)

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

    2012-01-01

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

  12. Hydrodynamic Modelling and Experimental Analysis of FE-DMFC Stacks

    Science.gov (United States)

    Kablou, Yashar

    Direct methanol fuel cells (DMFCs) present some unique features such as having liquid fuel, quick refueling process, compact design and high energy density. These characteristics make them incredibly suitable as a promising power source for portable electronic applications, such as cell phones or laptop computers. Despite of these positive aspects, the commercial development of DMFCs has nevertheless been hindered by some important issues such as, carbon dioxide formation at the anode compartment and, methanol crossover through the membrane. Many researchers have tried to model the two-phase flow behavior inside the DMFC anode compartment using the "homogenous flow modelling" approach, which has proven to be inaccurate specially when dealing with DMFC stacks. On the other hand, several strategies to prevent methanol crossover have been suggested in the literature, including the use of a flowing electrolyte between the DMFC anode and cathode compartments. Preliminary tests on flowing electrolyte direct methanol fuel cells (FE-DMFCs) have shown promising results; however, further investigation should be carried out on the stack level. In the first part of this study, a quasi two-dimensional numerical model was developed, to predict the two-phase flow behavior within the DMFC anode compartment, both in single cell and stack levels. Various types of flow modelling approaches and void fraction correlations were utilized to estimate the pressure drop across the anode compartment. It was found that the "separated flow modelling" approach, as well as CISE correlation for void fraction (developed at the CISE labs in Milan), yield the best results. In the second part, a five-cell FE-DMFC stack unit with a parallel serpentine flow bed design and U-type manifold configuration, was developed and tested at various operating conditions. It was found that, the flowing electrolyte effectively reduced methanol crossover and, improved the stack performance.

  13. Study on the polarity, solubility, and stacking characteristics of asphaltenes

    KAUST Repository

    Zhang, Long-li

    2014-07-01

    The structure and transformation of fused aromatic ring system in asphaltenes play an important role in the character of asphaltenes, and in step affect the properties of heavy oils. Polarity, solubility and structural characteristics of asphaltenes derived from Tahe atmospheric residue (THAR) and Tuo-826 heavy crude oil (Tuo-826) were analyzed for study of their internal relationship. A fractionation method was used to separate the asphaltenes into four sub-fractions, based on their solubility in the mixed solvent, for the study of different structural and physical-chemical properties, such as polarity, solubility, morphology, stacking characteristics, and mean structural parameters. Transmission electron microscope (TEM) observation can present the intuitive morphology of asphaltene molecules, and shows that the structure of asphaltenes is in local order as well as long range disorder. The analysis results showed that n-heptane asphaltenes of THAR and Tuo-826 had larger dipole moment values, larger fused aromatic ring systems, larger mean number of stacking layers, and less interlayer spacing between stacking layers than the corresponding n-pentane asphaltenes. The sub-fractions that were inclined to precipitate from the mixture of n-heptane and tetrahydrofuran had larger polarity and less solubility. From the first sub-fraction to the fourth sub-fraction, polarity, mean stacking numbers, and average layer size from the TEM images follow a gradual decrease. The structural parameters derived from TEM images could reflect the largest fused aromatic ring system in asphaltene molecule, yet the parameters derived from 1H NMR data reflected the mean message of poly-aromatic ring systems. The structural parameters derived from TEM images were more consistent with the polarity variation of sub-fractions than those derived from 1H NMR data, which indicates that the largest fused aromatic ring system will play a more important role in the stacking characteristics of

  14. Do Stacked Species Distribution Models Reflect Altitudinal Diversity Patterns?

    Science.gov (United States)

    Mateo, Rubén G.; Felicísimo, Ángel M.; Pottier, Julien; Guisan, Antoine; Muñoz, Jesús

    2012-01-01

    The objective of this study was to evaluate the performance of stacked species distribution models in predicting the alpha and gamma species diversity patterns of two important plant clades along elevation in the Andes. We modelled the distribution of the species in the Anthurium genus (53 species) and the Bromeliaceae family (89 species) using six modelling techniques. We combined all of the predictions for the same species in ensemble models based on two different criteria: the average of the rescaled predictions by all techniques and the average of the best techniques. The rescaled predictions were then reclassified into binary predictions (presence/absence). By stacking either the original predictions or binary predictions for both ensemble procedures, we obtained four different species richness models per taxa. The gamma and alpha diversity per elevation band (500 m) was also computed. To evaluate the prediction abilities for the four predictions of species richness and gamma diversity, the models were compared with the real data along an elevation gradient that was independently compiled by specialists. Finally, we also tested whether our richness models performed better than a null model of altitudinal changes of diversity based on the literature. Stacking of the ensemble prediction of the individual species models generated richness models that proved to be well correlated with the observed alpha diversity richness patterns along elevation and with the gamma diversity derived from the literature. Overall, these models tend to overpredict species richness. The use of the ensemble predictions from the species models built with different techniques seems very promising for modelling of species assemblages. Stacking of the binary models reduced the over-prediction, although more research is needed. The randomisation test proved to be a promising method for testing the performance of the stacked models, but other implementations may still be developed. PMID

  15. High-throughput Three-dimensional Gel Electrophoresis for Versatile Utilities: A Stacked Slice-gel System for Separation and Reactions (4SR)

    OpenAIRE

    Salimullah, Md.; Mori, Masaki; Nishigaki, Koichi

    2006-01-01

    A novel high-throughput system, called the stacked slice-gel system for separation and reactions (4SR), was developed for the analysis of DNA/RNA and protein/peptide. The system provides a novel three-dimensional gel electrophoresis approach that exploits the property of stacked slice gels. It allows multiple samples simultaneously to react as well as to be separated, offering a two-dimensional (m ? n) sample loading system. For this purpose, high-throughput multi-micro vessels (MMVs) contain...

  16. Method of detecting stacks with leaky fuel elements in liquid-metal-cooled reactor and apparatus for effecting same

    International Nuclear Information System (INIS)

    Aristarkhov, N.N.; Efimov, I.A.; Zaistev, B.I.; Peters, I.G.; Tymosh, B.S.

    1976-01-01

    Described is a method of detecting stacks with leaky fuel elements in a liquid-metal-cooled reactor, consisting in that prior to withdrawing a coolant sample, gas is accumulated in the coolant of the stack being controlled, the reactor being shut down, separated from the sample by means of an inert carrier gas, and the radioactivity of the separated gas is measured. An apparatus for carrying out said method comprises a sampler in the form of a tube parallel to the reactor axis in the hole of a rotating plug and adapted to move along the reactor axis. Made in the top portion of the tube are holes for the introduction of the inert carrier gas and the removal thereof together with the gases evolved from the coolant, while the bottom portion of the tube is provided with a sealing member

  17. Career Satisfaction Following Technical Education

    Science.gov (United States)

    McDonald, Betty Manager

    2011-01-01

    The effect of career and technical education in the Caribbean is an area of intervention research that needs more attention. This present research is the first of its kind within the region. The study benefits from a large sample size (N = 500) conducted among a non-traditional population in the field of career development. This paper reports on…

  18. Study of the mechanism of acetonitrile stacking and its application for directly combining liquid-phase microextraction with micellar electrokinetic chromatography.

    Science.gov (United States)

    Sun, Jingru; Feng, Jing; Shi, Ludi; Liu, Laping; He, Hui; Fan, Yingying; Hu, Shibin; Liu, Shuhui

    2016-08-26

    Acetonitrile stacking is an online concentration method that is distinctive due to its inclusion of a high proportion of organic solvent in sample matrices. We previously designed a universal methodology for the combination of liquid-phase microextraction (LPME) and capillary electrophoresis (CE) using acetonitrile stacking and micellar electrokinetic chromatography (MEKC) mode, thereby achieving large-volume injection of the diluted LPME extractant and the online concentration. In this report, the methodology was extended to the analysis of highly substituted hydrophobic chlorophenols in wines using diethyl carbonate as the extractant. Additionally, the mechanism of acetonitrile stacking was studied. The results indicated that the combination of LPME and MEKC exhibited good analytical performance: with ∼40-fold concentration by LPME, a 20-cm (33% of the total length) sample plug injection of an eight-fold dilution of diethyl carbonate with the organic solvent-saline solution produced enrichments higher by a factor of 260-791. Limits of qualification ranged from 5.5 to 16.0ng/mL. Acceptable reproducibilities of lower than 1.8% for migration time and 8.6% for peak areas were obtained. A dual stacking mechanism of acetonitrile stacking was revealed, involving transient isotachophoresis plus pH-junction stacking. The latter was associated with a pH shift induced by the presence of acetonitrile. The pseudo-stationary phase (Brij-35) played an important role in reducing the CE running time by weakening the isotachophoretic migration of the analyte ions following Cl(-) ions. The combination of acetonitrile stacking and nonionic micelle-based MEKC appears to be a perfect match for introducing water-immiscible LPME extractants into an aqueous CE system and can thus significantly expand the application of LPME-CE in green analytical chemistry. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Final Technical Report for Award DESC0011912, "Trimodal Tapping Mode Atomic Force Microscopy: Simultaneous 4D Mapping of Conservative and Dissipative Probe-Sample Interactions of Energy-Relevant Materials”

    Energy Technology Data Exchange (ETDEWEB)

    Solares, Santiago D. [George Washington Univ., Washington, DC (United States)

    2017-09-22

    The final project report covering the period 7/1/14-6/30/17 provides an overview of the technical accomplishments in the areas of (i) fundamental viscoelasticity, (ii) multifrequency atomic force microscopy, and (iii) characterization of energy-relevant materials with atomic force microscopy. A list of publications supported by the project is also provided.

  20. Strategy of technical innovation

    International Nuclear Information System (INIS)

    Lee, Ga Jong

    1990-12-01

    This book deals with policy of scientific technique and technical innovation such as research for development and types of technical innovation, historical development and process of technical innovation, economic growth, technology change and investment for research and development, structure and form of technical transfer with the meaning process, from, structure and theory, economic growth and investment of research and development with experiential analysis and case study on strategy of technical innovation in electron and fine chemical industry.

  1. Technical Efficiency of the Spanish Dairy

    NARCIS (Netherlands)

    Kapelko, M.; Oude Lansink, A.G.J.M.

    2013-01-01

    This chapter uses DEA to measure the technical efficiency of a sample of Spanish dairy processing firms over the period 2001–2009. Differences in technical efficiency between firms of different sizes and between firms that operated in international markets versus those that were not are tested. The

  2. Electronic structure of the rotation twin stacking fault in β-ZnS

    International Nuclear Information System (INIS)

    Northrup, J.E.; Cohen, M.L.

    1981-01-01

    The electronic structure of the rotation twin stacking fault in β-ZnS is calculated with the self-consistent pseudopotential method. The stacking fault creates a potential barrier of approx.0.07 eV and induces the localization of stacking-fault resonances near the top of the valence band. Stacking-fault states are also predicted to exist in the various gaps in the projected valence-band structure

  3. Investigation of Ruthenium Dissolution in Advanced Membrane Electrode Assemblies for Direct Methanol Based Fuel Cells Stacks

    Science.gov (United States)

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

    2005-01-01

    This viewgraph presentation gives a detailed review of the Direct Methanol Based Fuel Cell (DMFC) stack and investigates the Ruthenium that was found at the exit of the stack. The topics include: 1) Motivation; 2) Pathways for Cell Degradation; 3) Cell Duration Testing; 4) Duration Testing, MEA Analysis; and 5) Stack Degradation Analysis.

  4. The Methods of Design and Implementation of Stack Filters for Image Processing

    Directory of Open Access Journals (Sweden)

    S. Marchevsky

    1995-04-01

    Full Text Available This paper deals with a large class of nonlinear digital filters, the stack filters, which contain all combinations and compositions of rank order operators within a finite window. Attention is given to design and effective hardware implementation of an optimal stack filter for image processing. Presented simulation results confirm robustness of stack filters in the image restoration corrupted by impulsive noise.

  5. The Effect of a Sport Stacking Intervention on Handwriting with Second Grade Students

    Science.gov (United States)

    Li, Yuhua; Coleman, Diane; Ransdell, Mary; Coleman, Lyndsie; Irwin, Carol

    2014-01-01

    The present study examined the impact a 14-week sport stacking (cup stacking) exercise intervention would have on children's handwriting quality and speed. Eighty-three second graders were randomly assigned to either an experimental or a control group. The experimental group (n = 42) participated in a 15-min session of sport stacking activities…

  6. Modelling and Evaluation of Heating Strategies for High Temperature Polymer Electrolyte Membrane Fuel Cell Stacks

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2008-01-01

    Experiments were conducted on two different cathode air cooled high temperature PEM (HTPEM) fuel cell stacks; a 30 cell 400W prototype stack using two bipolar plates per cell, and a 65 cell 1 kW commercial stack using one bipolar plate per cell. The work seeks to examine the use of different...

  7. Spam comments prediction using stacking with ensemble learning

    Science.gov (United States)

    Mehmood, Arif; On, Byung-Won; Lee, Ingyu; Ashraf, Imran; Choi, Gyu Sang

    2018-01-01

    Illusive comments of product or services are misleading for people in decision making. The current methodologies to predict deceptive comments are concerned for feature designing with single training model. Indigenous features have ability to show some linguistic phenomena but are hard to reveal the latent semantic meaning of the comments. We propose a prediction model on general features of documents using stacking with ensemble learning. Term Frequency/Inverse Document Frequency (TF/IDF) features are inputs to stacking of Random Forest and Gradient Boosted Trees and the outputs of the base learners are encapsulated with decision tree to make final training of the model. The results exhibits that our approach gives the accuracy of 92.19% which outperform the state-of-the-art method.

  8. Radar Target Recognition Based on Stacked Denoising Sparse Autoencoder

    Directory of Open Access Journals (Sweden)

    Zhao Feixiang

    2017-04-01

    Full Text Available Feature extraction is a key step in radar target recognition. The quality of the extracted features determines the performance of target recognition. However, obtaining the deep nature of the data is difficult using the traditional method. The autoencoder can learn features by making use of data and can obtain feature expressions at different levels of data. To eliminate the influence of noise, the method of radar target recognition based on stacked denoising sparse autoencoder is proposed in this paper. This method can extract features directly and efficiently by setting different hidden layers and numbers of iterations. Experimental results show that the proposed method is superior to the K-nearest neighbor method and the traditional stacked autoencoder.

  9. High specific power, direct methanol fuel cell stack

    Science.gov (United States)

    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.

  10. Detailed experimental characterization of a reformate fuelled PEM stack

    DEFF Research Database (Denmark)

    Korsgaard, Anders; Nielsen, Mads Pagh; Kær, Søren Knudsen

    2006-01-01

    Increasing attention is given to fuel cells for micro combined heat and power systems for local households. Currently, mainly three different types of fuel cells are commercially competitive: SOFC, low- and high-temperature PEM fuel cells. In the present paper the Low Temperature PEM technology...... is in focus. To be able to design highly efficient micro CHP systems, it is critical to have a reliable performance map of not only the stack performance in the nominal operating point but also at system part load.  Issues like parasitic power consumption of the balance of plant components, dynamic...... with electric power output from 1-3-kW. All process inputs for the stack can be altered to provide realistic performance analyses, corresponding to those encountered in field applications. These include cathode/anode dew point control, cathode flow rate, cooling water temperature control as well as synthesis...

  11. STACKING ON COMMON REFLECTION SURFACE WITH MULTIPARAMETER TRAVELTIME

    Directory of Open Access Journals (Sweden)

    Montes V. Luis A.

    2006-12-01

    Full Text Available Commonly seismic images are displayed in time domain because the model in depth can be known only in well logs. To produce seismic sections, pre and post stack processing approaches use time or depth velocity models whereas the common reflection method does not, instead it requires a set of parameters established for the first layer. A set of synthetic data of an anticline model, with sources and receivers placed on a flat topography, was used to observe the performance of this method. As result, a better reflector recovering compared against conventional processing sequence was observed.
    The procedure was extended to real data, using a dataset acquired on a zone characterized by mild topography and quiet environment reflectors in the Eastern Colombia planes, observing an enhanced and a better continuity of the reflectors in the CRS stacked section.

  12. Physically Connected Stacked Patch Antenna Design with 100% Bandwidth

    KAUST Repository

    Klionovski, Kirill

    2017-11-01

    Typically, stacked patch antennas are parasitically coupled and provide larger bandwidth than a single patch antenna. Here, we show a stacked patch antenna design where square patches with semi-circular cutouts are physically connected to each other. This arrangement provides 100% bandwidth from 23.9–72.2 GHz with consistent high gain (5 dBi or more) across the entire bandwidth. In another variation, a single patch loaded with a superstrate provides 83.5% bandwidth from 25.6–62.3 GHz. The mechanism of bandwidth enhancement is explained through electromagnetic simulations. Measured reflection coefficient, radiation patterns and gain results confirm the extremely wideband performance of the design.

  13. Piezoelectric Multilayer-Stacked Hybrid Actuation/Transduction System

    Science.gov (United States)

    Xu, Tian-Bing (Inventor); Jiang, Xiaoning (Inventor); Su, Ji (Inventor)

    2014-01-01

    A novel full piezoelectric multilayer stacked hybrid actuation/transduction system. The system demonstrates significantly-enhanced electromechanical performance by utilizing the cooperative contributions of the electromechanical responses of multilayer stacked negative and positive strain components. Both experimental and theoretical studies indicate that for this system, the displacement is over three times that of a same-sized conventional flextensional actuator/transducer. The system consists of at least 2 layers which include electromechanically active components. The layers are arranged such that when electric power is applied, one layer contracts in a transverse direction while the second layer expands in a transverse direction which is perpendicular to the transverse direction of the first layer. An alternate embodiment includes a third layer. In this embodiment, the outer two layers contract in parallel transverse directions while the middle layer expands in a transverse direction which is perpendicular to the transverse direction of the outer layers.

  14. Remote Sensing Image Classification Based on Stacked Denoising Autoencoder

    Directory of Open Access Journals (Sweden)

    Peng Liang

    2017-12-01

    Full Text Available Focused on the issue that conventional remote sensing image classification methods have run into the bottlenecks in accuracy, a new remote sensing image classification method inspired by deep learning is proposed, which is based on Stacked Denoising Autoencoder. First, the deep network model is built through the stacked layers of Denoising Autoencoder. Then, with noised input, the unsupervised Greedy layer-wise training algorithm is used to train each layer in turn for more robust expressing, characteristics are obtained in supervised learning by Back Propagation (BP neural network, and the whole network is optimized by error back propagation. Finally, Gaofen-1 satellite (GF-1 remote sensing data are used for evaluation, and the total accuracy and kappa accuracy reach 95.7% and 0.955, respectively, which are higher than that of the Support Vector Machine and Back Propagation neural network. The experiment results show that the proposed method can effectively improve the accuracy of remote sensing image classification.

  15. Rain Sensor with Stacked Light Waveguide Having Tilted Air Gap

    Directory of Open Access Journals (Sweden)

    Kyoo Nam Choi

    2014-01-01

    Full Text Available Vehicle sensor to detect rain drop on and above waveguide utilizing light deflection and scattering was realized, keeping wide sensing coverage and sensitivity to detect mist accumulation. Proposed sensor structure under stacked light wave guide consisted of light blocking fixture surrounding photodetector and adjacent light source. Tilted air gap between stacked light waveguide and light blocking fixture played major role to increase sensitivity and to enhance linearity. This sensor structure eliminated complex collimating optics, while keeping wide sensing coverage using simple geometry. Detection algorithm based on time-to-intensity transformation process was used to convert raining intensity into countable raining process. Experimental result inside simulated rain chamber showed distinct different response between light rain and normal rain. Application as automobile rain sensor is expected.

  16. Stack monitor for the Proof-of-Breeding Project

    International Nuclear Information System (INIS)

    Fergus, R.W.

    1985-01-01

    This stack monitor system is a coordinated arrangement of hardware and software to monitor four hot cells (8 stacks) during the fuel dissection for the Proof-of-Breeding Project. The cell monitors, which are located in fan lofts, contain a microprocessor, radiation detectors, air flow sensors, and air flow control equipment. Design criteria included maximizing microprocessor control while minimizing the hardware complexity. The monitors have been programmed to produce concentration and total activity release data based on several detector measurements and flow rates. Although each monitor can function independently, a microcomputer can also be used to control each cell monitor including reprogramming if necessary. All programming is software, as opposed to firmware, with machine language for compactness in the cell monitors and Basic language for adaptability in the microcomputer controller

  17. The Effect of NPP's Stack Height to Radiation Dose

    International Nuclear Information System (INIS)

    Pandi, Liliana Yetta; Rohman, Budi

    2003-01-01

    The purpose of dose calculation for accidents is to analyze the capability of NPP to maintain the safety of public and workers in case an accident occurs on the Plant in a site. This paper calculates the Loss of Coolant Accident in PWR plant. The calculation results shows that no risks of serious radiation exposure are given to the neighboring public even if such a large accident occurred, and the effect of stack height can be predicted by analysis of the calculation results. The whole dose is calculated for some location (100 m, 300 m, 500 m, 700 m, 900 m, 1500 m, and 2000 m) with three difference stack height i.e. 0 m, 40 m and 100 m. The result of the whole dose calculation is under permitted criteria for whole dose : 0.25 Sv and thyroid dose : 3.0 Sv. The calculation of radiation dose in this paper use EEDCDQ code

  18. Performance of PZT stacks under high-field electric cycling at various temperatures in heavy-duty diesel engine fuel injectors

    Science.gov (United States)

    Wang, Hong; Lee, Sung-Min; Lin, Hua-Tay; Stafford, Randy

    2016-04-01

    Testing and characterization of large prototype lead zirconate titanate (PZT) stacks present substantial technical challenges to electronic systems. The work in this study shows that an alternative approach can be pursued by using subunits extracted from prototype stacks. Piezoelectric and dielectric integrity was maintained even though the PZT plate specimens experienced an additional loading process involved with the extraction after factory poling. Extracted 10-layer plate specimens were studied by an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 108 cycles, both at room temperature (22°C) and at 50°C. The elevated temperature had a defined impact on the fatigue of PZT stacks. About 48 and 28% reductions were observed in the piezoelectric and dielectric coefficients, respectively, after 108 cycles at 50°C, compared with reductions of 25 and 15% in the respective coefficients at 22°C. At the same time, the loss tangent varied to a limited extent. The evolution of PZT-electrode interfacial layers or nearby dielectric layers should account for the difference in the fatigue rates of piezoelectric and dielectric coefficients. But the basic contribution to observed fatigue may result from the buildup of a bias field that finally suppressed the motion of the domain walls. Finally, monitoring of dielectric coefficients can be an effective tool for on-line lifetime prediction of PZT stacks in service if a failure criterion is defined properly.

  19. Mathematical modeling of a V-stack piezoelectric aileron actuation

    Directory of Open Access Journals (Sweden)

    Ioan URSU

    2016-12-01

    Full Text Available The article presents a mathematical modeling of aileron actuation that uses piezo V-shaped stacks. The aim of the actuation is the increasing of flutter speed in the context of a control law, in order to widen the flight envelope. In this way the main advantage of such a piezo actuator, the bandwidth is exploited. The mathematical model is obtained based on free body diagrams, and the numerical simulations allow a preliminary sizing of the actuator.

  20. Basic design parameters for the new PRR-1 stack

    International Nuclear Information System (INIS)

    Leopando, L.S.

    1994-01-01

    This report presents the results of work done to establish the basic design parameters of the new stack of the Philippine Research Reactor-1 (PRR-1). The work was undertaken to assure that the radioactive air emissions of the PRR-1, under both accident and normal operating conditions, will comply with modern safety practices. The work was done during June and July 1994. (author). 6 refs., 13 figs., 13 tabs

  1. Review of the stack discharge active particle contamination problem

    Energy Technology Data Exchange (ETDEWEB)

    Parker, H M

    1948-03-22

    Quantities of the order of ten million to 100 million radioactive particles per month were emitted from the stacks over a period of several months. High activity in the range 0.1 to 3..mu..c was probably confined to large carrier particles of corrosion debris from iron ductwork in the separations plant ventilation air system. This report discusses chemical, physical and radiochemical properties of the particles, and possible biological and health effects of exposure to them. (ACR)

  2. Cutting Forces Prediction in the Dry Slotting of Aluminium Stacks

    OpenAIRE

    SALGUERO, Jorge; CALAMAZ, Madalina; BATISTA, Moises; GIROT, Franck; MARCOS, Mariano

    2014-01-01

    International audience; Cutting forces are one of the inherent phenomena and a very significant indicator of themetal cutting process. The work presented in this paper is an investigation of the prediction of these parameters in slotting processes of UNS A92024-T3 (Al-Cu) stacks. So, cutting speed (V) and feed per tooth (fz) based parametric models, for experimental components of cutting force, F(fz,V) have been proposed. These models have been developed from the individual models extracted f...

  3. Availability Analysis of the Ventilation Stack CAM Interlock System

    CERN Document Server

    Young, J

    2000-01-01

    Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies, and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability.

  4. Structure of a stacked anthraquinone–DNA complex

    Science.gov (United States)

    De Luchi, Daniela; Usón, Isabel; Wright, Glenford; Gouyette, Catherine; Subirana, Juan A.

    2010-01-01

    The crystal structure of the telomeric sequence d(UBrAGG) interacting with an anthraquinone derivative has been solved by MAD. In all previously studied complexes of intercalating drugs, the drug is usually sandwiched between two DNA base pairs. Instead, the present structure looks like a crystal of stacked anthraquinone molecules in which isolated base pairs are intercalated. Unusual base pairs are present in the structure, such as G·G and A·UBr reverse Watson–Crick base pairs. PMID:20823516

  5. Consolidity: Stack-based systems change pathway theory elaborated

    OpenAIRE

    Dorrah, Hassen Taher

    2014-01-01

    This paper presents an elaborated analysis for investigating the stack-based layering processes during the systems change pathway. The system change pathway is defined as the path resulting from the combinations of all successive changes induced on the system when subjected to varying environments, activities, events, or any excessive internal or external influences and happenings “on and above” its normal stands, situations or set-points during its course of life. The analysis is essentially...

  6. Numerical simulations of flux flow in stacked Josephson junctions

    DEFF Research Database (Denmark)

    Madsen, Søren Peder; Pedersen, Niels Falsig

    2005-01-01

    We numerically investigate Josephson vortex flux flow states in stacked Josephson junctions, motivated by recent experiments trying to observe the vortices in a square vortex lattice when a magnetic field is applied to layered high-Tc superconductors of the Bi2Sr2CaCu2Ox type. By extensive...... numerical simulations, we are able to clearly distinguish between triangular and square vortex lattices and to identify the parameters leading to an in-phase vortex configuration....

  7. High Temperature PEM Fuel Cell Stacks with Advent TPS Meas

    Directory of Open Access Journals (Sweden)

    Neophytides Stylianos

    2017-01-01

    Full Text Available High power/high energy applications are expected to greatly benefit from high temperature Polymer Electrolyte Membrane Fuel Cells (PEMFCs. In this work, a combinatorial approach is presented, in which separately developed and evaluated MEAs, design and engineering are employed to result in reliable and effective stacks operating above 180°C and having the characteristics well matched to applications including auxiliary power, micro combined heat and power, and telecommunication satellites.

  8. Parametric Sensitivity Tests- European PEM Fuel Cell Stack Test Procedures

    DEFF Research Database (Denmark)

    Araya, Samuel Simon; Andreasen, Søren Juhl; Kær, Søren Knudsen

    2014-01-01

    performed based on test procedures proposed by a European project, Stack-Test. The sensitivity of a Nafion-based low temperature PEMFC stack’s performance to parametric changes was the main objective of the tests. Four crucial parameters for fuel cell operation were chosen; relative humidity, temperature......, pressure, and stoichiometry at varying current density. Furthermore, procedures for polarization curve recording were also tested both in ascending and descending current directions....

  9. Nature and magnitude of aromatic stacking of nucleic acid bases

    Czech Academy of Sciences Publication Activity Database

    Šponer, Jiří; Riley, K.E.; Hobza, Pavel

    2008-01-01

    Roč. 10, č. 19 (2008), s. 2595-2610 ISSN 1463-9076 R&D Projects: GA AV ČR(CZ) IAA400550510 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702; CEZ:AV0Z40550506 Keywords : quantum chemical calculations * base-stacking * DNA Subject RIV: BO - Biophysics Impact factor: 4.064, year: 2008

  10. Simulation Of Networking Protocols On Software Emulated Network Stack

    Directory of Open Access Journals (Sweden)

    Hrushikesh Nimkar

    2015-08-01

    Full Text Available With the increasing number and complexity of network based applications the need to easy configuration development and integration of network applications has taken a high precedence. Trivial activities such as configuration can be carried out efficiently if network services are software based rather than hardware based. Project aims at enabling the network engineers to easily include network functionalities into hisher configuration and define hisher own network stack without using the kernel network stack. Having thought of this we have implemented two functionalities UPNP and MDNS. The multicast Domain Name System MDNS resolves host names to IP addresses within small ad-hoc networks and without having need of special DNS server and its configuration. MDNS application provides every host with functionality to register itself to the router make a multicast DNS request and its resolution. To make adding network devices and networked programs to a network as easy as it is to plug in a piece of hardware into a PC we make use of UPnP. The devices and programs find out about the network setup and other networked devices and programs through discovery and advertisements of services and configure themselves accordingly. UPNP application provides every host with functionality of discovering services of other hosts and serving requests on demand. To implement these applications we have used snabbswitch framework which an open source virtualized ethernet networking stack.

  11. Stacking-Based Visualization of Trajectory Attribute Data.

    Science.gov (United States)

    Tominski, C; Schumann, H; Andrienko, G; Andrienko, N

    2012-12-01

    Visualizing trajectory attribute data is challenging because it involves showing the trajectories in their spatio-temporal context as well as the attribute values associated with the individual points of trajectories. Previous work on trajectory visualization addresses selected aspects of this problem, but not all of them. We present a novel approach to visualizing trajectory attribute data. Our solution covers space, time, and attribute values. Based on an analysis of relevant visualization tasks, we designed the visualization solution around the principle of stacking trajectory bands. The core of our approach is a hybrid 2D/3D display. A 2D map serves as a reference for the spatial context, and the trajectories are visualized as stacked 3D trajectory bands along which attribute values are encoded by color. Time is integrated through appropriate ordering of bands and through a dynamic query mechanism that feeds temporally aggregated information to a circular time display. An additional 2D time graph shows temporal information in full detail by stacking 2D trajectory bands. Our solution is equipped with analytical and interactive mechanisms for selecting and ordering of trajectories, and adjusting the color mapping, as well as coordinated highlighting and dedicated 3D navigation. We demonstrate the usefulness of our novel visualization by three examples related to radiation surveillance, traffic analysis, and maritime navigation. User feedback obtained in a small experiment indicates that our hybrid 2D/3D solution can be operated quite well.

  12. Slip-stacking Dynamics and the 20 Hz Booster

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, Jeffery; Zwaska, Robert

    2015-03-01

    Slip-stacking is an accumulation technique used at Fermilab since 2004 which nearly doubles the proton intensity. The Proton Improvement Plan II intensity upgrades require a reduction in slip-stacking losses by approximately a factor of 2. We study the single-particle dynamics that determine the stability of slip-stacking particles. We introduce universal area factors to calculate the available phase space area for any set of beam parameters without individual simulation. We show the particle loss as a function of time. We calculate the injection efficiency as a function of longitudinal emittance and aspect-ratio. We demonstrate that the losses from RF single particle dynamics can be reduced by a factor of 4-10 (depending on beam parameters) by upgrading the Fermilab Booster from a 15-Hz cycle-rate to a 20-Hz cycle-rate. We recommend a change in injection scheme to eliminate the need for a greater momentum aperture in the Fermilab Recycler.

  13. Calculated stacking-fault energies of elemental metals

    DEFF Research Database (Denmark)

    Rosengaard, N. M.; Skriver, Hans Lomholt

    1993-01-01

    We have performed ab initio calculations of twin, intrinsic, and extrinsic face-centered-cubic stacking faults for all the 3d, 4d, and 5d transition metals by means of a Green's-function technique, based on the linear-muffin-tin-orbitals method within the tight-binding and atomic-sphere approxima......We have performed ab initio calculations of twin, intrinsic, and extrinsic face-centered-cubic stacking faults for all the 3d, 4d, and 5d transition metals by means of a Green's-function technique, based on the linear-muffin-tin-orbitals method within the tight-binding and atomic......-sphere approximations. The results are in excellent agreement with recent layer Korringa-Kohn-Rostoker Green's-function calculations where stacking-fault energies for Ni, Cu, Rh, Pd, Ag, Ir, and Au were found by means of the the so-called force theorem. We find that the self-consistent fault energies for all the metals...... on the local atomic coordination are obeyed to a high degree of accuracy....

  14. Nuclear Magnetic Shieldings of Stacked Aromatic and Antiaromatic Molecules.

    Science.gov (United States)

    Sundholm, Dage; Rauhalahti, Markus; Özcan, Nergiz; Mera-Adasme, Raúl; Kussmann, Jörg; Luenser, Arne; Ochsenfeld, Christian

    2017-05-09

    Nuclear magnetic shieldings have been calculated at the density functional theory (DFT) level for stacks of benzene, hexadehydro[12]annulene, dodecadehydro[18]annulene, and hexabenzocoronene. The magnetic shieldings due to the ring currents in the adjacent molecules have been estimated by calculating nucleus independent molecular shieldings for the monomer in the atomic positions of neighbor molecules. The calculations show that the independent shielding model works reasonably well for the 1 H NMR shieldings of benzene and hexadehydro[12]annulene, whereas for the larger molecules and for the 13 C NMR shieldings the interaction between the molecules leads to shielding effects that are at least of the same size as the ring current contributions from the adjacent molecules. A better agreement is obtained when the nearest neighbors are also considered at full quantum mechanical (QM) level. The calculations suggest that the nearest solvent molecules must be included in the quantum mechanical system, at least when estimating solvent shifts at the molecular mechanics (MM) level. Current density calculations show that the stacking does not significantly affect the ring current strengths of the individual molecules, whereas the shape of the ring current for a single molecule differs from that of the stacked molecules.

  15. Multibands tunneling in AAA-stacked trilayer graphene

    Science.gov (United States)

    Redouani, Ilham; Jellal, Ahmed; Bahaoui, Abdelhadi; Bahlouli, Hocine

    2018-04-01

    We study the electronic transport through np and npn junctions for AAA-stacked trilayer graphene. Two kinds of gates are considered where the first is a single gate and the second is a double gate. After obtaining the solutions for the energy spectrum, we use the transfer matrix method to determine the three transmission probabilities for each individual cone τ = 0 , ± 1 . We show that the quasiparticles in AAA-stacked trilayer graphene are not only chiral but also labeled by an additional cone index τ. The obtained bands are composed of three Dirac cones that depend on the chirality indexes. We show that there is perfect transmission for normal or near normal incidence, which is a manifestation of the Klein tunneling effect. We analyze also the corresponding total conductance, which is defined as the sum of the conductance channels in each individual cone. Our results are numerically discussed and compared with those obtained for ABA- and ABC-stacked trilayer graphene.

  16. Comparison of strain fields in truncated and un-truncated quantum dots in stacked InAs/GaAs nanostructures with varying stacking periods

    CERN Document Server

    Shin, H; Yoo, Y H

    2003-01-01

    Strain fields in truncated and un-truncated InAs quantum dots with the same height and base length have been compared numerically when the dots are vertically stacked in a GaAs matrix at various stacking periods. The compressive hydrostatic strain in truncated dots decreases slightly as compared with the un-truncated dots without regard to the stacking period studied. However, the reduction in tensile biaxial strain, compressive radial strain and tensile axial strain was salient in the truncated dot and the reduction increased with decreasing stacking period. From such changes in strain, changes in the band gap and related properties are anticipated.

  17. Diffusion of Nickel into Ferritic Steel Interconnects of Solid Oxide Fuel/Electrolysis Stacks

    DEFF Research Database (Denmark)

    Molin, Sebastian; Chen, Ming; Bowen, Jacob R.

    2013-01-01

    diffusion of nickel from the Ni/YSZ electrode or the contact layer into the interconnect plate. Such diffusion can cause austenization of the ferritic structure and could possibly alter corrosion properties of the steel. Whereas this process has already been recognized by SOFC stack developers, only...... a limited number of studies have been devoted to the phenomenon. Here, diffusion of Ni into ferritic Crofer 22 APU steel is studied in a wet hydrogen atmosphere after 250 hours of exposure at 800 °C using Ni-plated (~ 10 micron thick coatings) sheet steel samples as a model system. Even after...... this relatively short time all the metallic nickel in the coating has reacted and formed solid solutions with iron and chromium. Diffusion of Ni into the steel causes formation of the austenite FCC phase. The microstructure and composition of the oxide scale formed on the sample surface after 250 hours is similar...

  18. Technical efficiency, efficiency change, technical progress and ...

    African Journals Online (AJOL)

    Technical efficiency, efficiency change, technical progress and productivity growth in the national health systems of continental African countries. ... a view to analysing changes in efficiency and changes in technology. The analysis was based on a five-year panel data (1999-2003) from all the 53 countries of continental ...

  19. Identification of critical parameters for PEMFC stack performance characterization and control strategies for reliable and comparable stack benchmarking

    DEFF Research Database (Denmark)

    Mitzel, Jens; Gülzow, Erich; Kabza, Alexander

    2016-01-01

    This paper is focused on the identification of critical parameters and on the development of reliable methodologies to achieve comparable benchmark results. Possibilities for control sensor positioning and for parameter variation in sensitivity tests are discussed and recommended options for the ......This paper is focused on the identification of critical parameters and on the development of reliable methodologies to achieve comparable benchmark results. Possibilities for control sensor positioning and for parameter variation in sensitivity tests are discussed and recommended options...... in an average cell voltage deviation of 21 mV. Test parameters simulating different stack applications are summarized. The stack demonstrated comparable average cell voltage of 0.63 V for stationary and portable conditions. For automotive conditions, the voltage increased to 0.69 V, mainly caused by higher...

  20. Measurements of the LHCb software stack on the ARM architecture

    International Nuclear Information System (INIS)

    Kartik, S Vijay; Couturier, Ben; Clemencic, Marco; Neufeld, Niko

    2014-01-01

    The ARM architecture is a power-efficient design that is used in most processors in mobile devices all around the world today since they provide reasonable compute performance per watt. The current LHCb software stack is designed (and thus expected) to build and run on machines with the x86/x86 6 4 architecture. This paper outlines the process of measuring the performance of the LHCb software stack on the ARM architecture – specifically, the ARMv7 architecture on Cortex-A9 processors from NVIDIA and on full-fledged ARM servers with chipsets from Calxeda – and makes comparisons with the performance on x86 6 4 architectures on the Intel Xeon L5520/X5650 and AMD Opteron 6272. The paper emphasises the aspects of performance per core with respect to the power drawn by the compute nodes for the given performance – this ensures a fair real-world comparison with much more 'powerful' Intel/AMD processors. The comparisons of these real workloads in the context of LHCb are also complemented with the standard synthetic benchmarks HEPSPEC and Coremark. The pitfalls and solutions for the non-trivial task of porting the source code to build for the ARMv7 instruction set are presented. The specific changes in the build process needed for ARM-specific portions of the software stack are described, to serve as pointers for further attempts taken up by other groups in this direction. Cases where architecture-specific tweaks at the assembler lever (both in ROOT and the LHCb software stack) were needed for a successful compile are detailed – these cases are good indicators of where/how the software stack as well as the build system can be made more portable and multi-arch friendly. The experience gained from the tasks described in this paper are intended to i) assist in making an informed choice about ARM-based server solutions as a feasible low-power alternative to the current compute nodes, and ii) revisit the software design and build system for portability and

  1. Solid Oxide Cell and Stack Testing, Safety and Quality Assurance (SOCTESQA)

    DEFF Research Database (Denmark)

    Auer, C.; Lang, M.; Couturier, K.

    2015-01-01

    In the EU-funded project “SOCTESQA” partners from Europe and Singapore are working together to develop uniform and industry wide test procedures and protocols for solid oxide cells and stacks SOC cell/stack assembly. New application fields which are based on the operation of the SOC cell/stack as......In the EU-funded project “SOCTESQA” partners from Europe and Singapore are working together to develop uniform and industry wide test procedures and protocols for solid oxide cells and stacks SOC cell/stack assembly. New application fields which are based on the operation of the SOC cell...

  2. LAB3 Cosmic Ray Test Stand Analysis of Steel Stack Supports

    International Nuclear Information System (INIS)

    Cease, H.

    1998-01-01

    A cosmic ray test stand is being constructed at Lab 3. The stand consists of two stacks of steel plates one resting on top of the other. The top stack is composed of 6 plates of steel making an overall stack size of 34.5-inch x 40-inch x 99-inch. The bottom stack also has 6 layers of plate making an overall size of approximately 49.5-inch x 82-inch x 99-inch. The bottom stack is supported with three support legs. See drawing 3823.000ME-900428 for the individual plate orientation. The minimum support leg size and necessary welds between plates are determined.

  3. Dose assessment for potential radionuclide emissions from stacks on the Hanford Site: NESHAP compliance

    International Nuclear Information System (INIS)

    Davis, W.E.; Barnett, J.M.; Kenoyer, J.L.

    1994-03-01

    The purpose of this document is to present the assessment results for the registered stacks on the Hanford Site for potential emissions, i.e. emissions with no control devices in place. Further, the document will identify those stacks requiring continuous monitoring, i.e. the effective dose equivalent from potential emissions >0.1 mrem/yr. The stack assessment of potential emissions was performed on 84 registered stacks on the Hanford Site. These emission sources represent individual point sources presently registered under Washington Administrative code 246-247 with the Washington Department of Health. The methods used in assessing the potential emissions from the stacks are described

  4. LLNL 1981: technical horizons

    International Nuclear Information System (INIS)

    1981-07-01

    Research programs at LLNL for 1981 are described in broad terms. In his annual State of the Laboratory address, Director Roger Batzel projected a $481 million operating budget for fiscal year 1982, up nearly 13% from last year. In projects for the Department of Energy and the Department of Defense, the Laboratory applies its technical facilities and capabilities to nuclear weapons design and development and other areas of defense research that include inertial confinement fusion, nonnuclear ordnances, and particle-beam technology. LLNL is also applying its unique experience and capabilities to a variety of projects that will help the nation meet its energy needs in an environmentally acceptable manner. A sampling of recent achievements by LLNL support organizations indicates their diversity

  5. The computational optimization of heat exchange efficiency in stack chimneys

    Energy Technology Data Exchange (ETDEWEB)

    Van Goch, T.A.J.

    2012-02-15

    For many industrial processes, the chimney is the final step before hot fumes, with high thermal energy content, are discharged into the atmosphere. Tapping into this energy and utilizing it for heating or cooling applications, could improve sustainability, efficiency and/or reduce operational costs. Alternatively, an unused chimney, like the monumental chimney at the Eindhoven University of Technology, could serve as an 'energy channeler' once more; it can enhance free cooling by exploiting the stack effect. This study aims to identify design parameters that influence annual heat exchange in such stack chimney applications and optimize these parameters for specific scenarios to maximize the performance. Performance is defined by annual heat exchange, system efficiency and costs. The energy required for the water pump as compared to the energy exchanged, defines the system efficiency, which is expressed in an efficiency coefficient (EC). This study is an example of applying building performance simulation (BPS) tools for decision support in the early phase of the design process. In this study, BPS tools are used to provide design guidance, performance evaluation and optimization. A general method for optimization of simulation models will be studied, and applied in two case studies with different applications (heating/cooling), namely; (1) CERES case: 'Eindhoven University of Technology monumental stack chimney equipped with a heat exchanger, rejects heat to load the cold source of the aquifer system on the campus of the university and/or provides free cooling to the CERES building'; and (2) Industrial case: 'Heat exchanger in an industrial stack chimney, which recoups heat for use in e.g. absorption cooling'. The main research question, addressing the concerns of both cases, is expressed as follows: 'what is the optimal set of design parameters so heat exchange in stack chimneys is optimized annually for the cases in which a

  6. A new stack effluent monitoring system at the Risoe Hot Cell plant

    International Nuclear Information System (INIS)

    Boetter-Jensen, L.; Hedemann Jensen, P.; Lauridsen, B.

    1984-06-01

    This report describes a new stack effluent monitoring system that has been installed at the Hot Cell facility. It is an integrating iodine/particulate system consisting of a γ-shielded flow house in which a continous air sample from the ventilation channel ia sucked through coal and glass filter papers. Activity is accumulated on the filter papers and a thin plastic scintillator detects the β-radiation from the trapped iodine or particulate activity. The stack effluent monitoring system has a two-step regulating function as applied to the ventilation system, first switching it to a recirculating mode, and finally to building-seal after given releases of 131 I. The collection efficiency for iodine in form of elementary iodine (I 2 ) and methyliodide (CH 3 I) has been determined experimentally. The unwanted response from a noble gas release has also been determined from experiments. The noble gas response was determined from puff releases of the nuclide 41 Ar in the concrete cells. It is concluded that the iodine/particulate system is extremely sensitive and that it can easily detect iodine or particulate releases as low as a few MBq. A gamma monitor placed in connection with the iodine/particulate system detects Xe/Kr-releases as low as a few tens of MBq per second. (author)

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

    Science.gov (United States)

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

    2015-09-01

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

  8. Stacking-dependent electronic property of trilayer graphene epitaxially grown on Ru(0001)

    Energy Technology Data Exchange (ETDEWEB)

    Que, Yande; Xiao, Wende, E-mail: wdxiao@iphy.ac.cn, E-mail: hjgao@iphy.ac.cn; Chen, Hui; Wang, Dongfei; Du, Shixuan; Gao, Hong-Jun, E-mail: wdxiao@iphy.ac.cn, E-mail: hjgao@iphy.ac.cn [Institute of Physics and University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190 (China)

    2015-12-28

    The growth, atomic structure, and electronic property of trilayer graphene (TLG) on Ru(0001) were studied by low temperature scanning tunneling microscopy and spectroscopy in combined with tight-binding approximation (TBA) calculations. TLG on Ru(0001) shows a flat surface with a hexagonal lattice due to the screening effect of the bottom two layers and the AB-stacking in the top two layers. The coexistence of AA- and AB-stacking in the bottom two layers leads to three different stacking orders of TLG, namely, ABA-, ABC-, and ABB-stacking. STS measurements combined with TBA calculations reveal that the density of states of TLG with ABC- and ABB-stacking is characterized by one and two sharp peaks near to the Fermi level, respectively, in contrast to the V-shaped feature of TLG with ABA-stacking. Our work demonstrates that TLG on Ru(0001) might be an ideal platform for exploring stacking-dependent electronic properties of graphene.

  9. Preliminary study on rotary ultrasonic machining of CFRP/Ti stacks.

    Science.gov (United States)

    Cong, W L; Pei, Z J; Treadwell, C

    2014-08-01

    Reported drilling methods for CFRP/Ti stacks include twist drilling, end milling, core grinding, and their derived methods. The literature does not have any report on drilling of CFRP/Ti stacks using rotary ultrasonic machining (RUM). This paper, for the first time, reports a study on drilling of CFRP/Ti stacks using RUM. It also compares results on drilling of CFRP/Ti stacks using RUM with reported results on drilling of CFRP/Ti stacks using other methods. When drilling CFRP/Ti stacks using RUM, cutting force, torque, and CFRP surface roughness were lower, hole size variation was smaller, CFRP groove depth was smaller, tool life was longer, and there was no obvious Ti exit burr and CFRP entrance delamination. Ti surface roughness when drilling of CFRP/Ti stacks using RUM was about the same as those when using other methods. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Technical training: places available

    CERN Multimedia

    2013-01-01

    If you would like more information on a course, or for any other inquiry/suggestions, please contact Technical.Training@cern.ch. Eva Stern and Elise Romero, Technical Training Administration (Tel: 74924)

  11. Technical training - places available

    CERN Multimedia

    2013-01-01

    If you would like more information on a course, or have any other inquiry/suggestions, please contact Technical.Training@cern.ch. Eva Stern and Elise Romero, Technical Training Administration (Tel: 74924)

  12. Technical training: places available

    CERN Multimedia

    2014-01-01

    If you would like more information on a course, or have any other inquiry/suggestions, please contact Technical.Training@cern.ch. Eva Stern and Marie Lahchimi, Technical Training Administration (Tel: 74924)

  13. Technical training: places available

    CERN Multimedia

    2014-01-01

    If you would like more information on a course, or have any other inquiry/suggestions, please contact Technical.Training@cern.ch. Eva Stern and Elise Romero, Technical Training Administration (Tel: 74924)

  14. Technical training: places available

    CERN Multimedia

    2013-01-01

    If you would like more information on a course, or for any other inquiry/suggestions, please contact Technical.Training@cern.ch. Eva Stern and Elise Romero, Technical Training Administration (Tél : 74924)  

  15. Technical Assistance Plan (TAP)

    Science.gov (United States)

    A Technical Assistance Plan (TAP) enables community groups to retain the services of an independent technical advisor and to provide resources for a community group to help inform other community members about site decisions.

  16. Potential radionuclide emissions from stacks on the Hanford Site, Part 2: Dose assessment methodology using portable low-resolution gamma spectroscoy

    International Nuclear Information System (INIS)

    Barnett, J.M.

    1994-07-01

    In September 1992, the Westinghouse Hanford Company began developing an in situ measurement method to assess gamma radiation emanating from high-efficiency particulate air filters using portable low-resolution gamma spectroscopy. The purpose of the new method was to assess radioactive exhaust stack air emissions from empirical data rather than from theoretical models and to determine the potential unabated dose to an offsite theoretical maximally exposed individual. In accordance with Title 40, Code of Federal Regulations, Part 61, Subpart H, ''National Emission Standards for Hazardous Air Pollutants'', stacks that have the potential to emit ≥ 0.1 mrem per year to the maximally exposed individual are considered ''major'' and must meet the continuous monitoring requirements. After the method was tested and verified, the US Environmental Protection Agency, Region 10, approved its use in June 1993. Of the 125 stacks operated by the Westinghouse Hanford Company, 22 were targeted for evaluation by this method; and 15 were assessed. The most significant,result from this study was the redesignation. of the T Plant main stack. The stack was assessed as being ''minor'', and it now only requires periodic confirmatory measurements and meets federally imposed sampling requirements

  17. Generalized sampling in Julia

    DEFF Research Database (Denmark)

    Jacobsen, Christian Robert Dahl; Nielsen, Morten; Rasmussen, Morten Grud

    2017-01-01

    Generalized sampling is a numerically stable framework for obtaining reconstructions of signals in different bases and frames from their samples. For example, one can use wavelet bases for reconstruction given frequency measurements. In this paper, we will introduce a carefully documented toolbox...... for performing generalized sampling in Julia. Julia is a new language for technical computing with focus on performance, which is ideally suited to handle the large size problems often encountered in generalized sampling. The toolbox provides specialized solutions for the setup of Fourier bases and wavelets....... The performance of the toolbox is compared to existing implementations of generalized sampling in MATLAB....

  18. Teaching Technical Writing - Towards Technical Writing

    DEFF Research Database (Denmark)

    Kastberg, Peter

    2000-01-01

    In this paper I will present key aspects of the curriculum for the university degree in technical translation that I have designed for and subsequently implemented at the German Department of the Aarhus School of Business, Denmark. My starting point will be a critical discussion of the norm...... that used to govern what the quality of an LSP text should be as opposed to the standpoint, which I advocate. By way of summing up, I will show how a university curriculum is designed so that - upon graduation - the technical translator could also be methodological quite well suited to take on the challenge...... of technical writing....

  19. Oxidation precursor dependence of atomic layer deposited Al2O3 films in a-Si:H(i)/Al2O3 surface passivation stacks

    Science.gov (United States)

    Xiang, Yuren; Zhou, Chunlan; Jia, Endong; Wang, Wenjing

    2015-03-01

    In order to obtain a good passivation of a silicon surface, more and more stack passivation schemes have been used in high-efficiency silicon solar cell fabrication. In this work, we prepared a-Si:H(i)/Al2O3 stacks on KOH solution-polished n-type solar grade mono-silicon(100) wafers. For the Al2O3 film deposition, both thermal atomic layer deposition (T-ALD) and plasma enhanced atomic layer deposition (PE-ALD) were used. Interface trap density spectra were obtained for Si passivation with a-Si films and a-Si:H(i)/Al2O3 stacks by a non-contact corona C-V technique. After the fabrication of a-Si:H(i)/Al2O3 stacks, the minimum interface trap density was reduced from original 3 × 1012 to 1 × 1012 cm-2 eV-1, the surface total charge density increased by nearly one order of magnitude for PE-ALD samples and about 0.4 × 1012 cm-2 for a T-ALD sample, and the carrier lifetimes increased by a factor of three (from about 10 μs to about 30 μs). Combining these results with an X-ray photoelectron spectroscopy analysis, we discussed the influence of an oxidation precursor for ALD Al2O3 deposition on Al2O3 single layers and a-Si:H(i)/Al2O3 stack surface passivation from field-effect passivation and chemical passivation perspectives. In addition, the influence of the stack fabrication process on the a-Si film structure was also discussed in this study.

  20. An appraisal of undergraduate curriculum of technical education in ...

    African Journals Online (AJOL)

    The purpose of this study was to appraise the curriculum of technical teacher education in terms of its compatibility to the goals of the programme. A sample of three Universities offering technical teacher programme was used for the study. Components of the technical teacher education curriculum in each institution were ...

  1. Characterization of dry-stack interlocking compressed earth blocks

    OpenAIRE

    Moreira, Thomas Wilfried Sturm; Ramos, Luís F.; Lourenço, Paulo B.

    2015-01-01

    Earth has been a traditional building material to construct houses in Africa. One of the most common techniques is the use of sun dried or kiln fired adobe bricks with mud mortar. Fired bricks are the main cause for deforestation in countries like Malawi. Although this technique is low-cost, the bricks vary largely in shape, strength and durability. This leads to weak houses which suffer considerable damage during floods and seismic events. One solution is the use of dry-stack masonry with st...

  2. Production and Reliability Oriented SOFC Cell and Stack Design

    DEFF Research Database (Denmark)

    Hauth, Martin; Lawlor, Vincent; Cartellieri, Peter

    2017-01-01

    established. The probabilistic models were related to the experimentally obtained properties of base materials to establish a statistical relationship between the material properties and the most relevant load effects. Software algorithms for meta models that allow the detection of relationships between input...... in production, material and operating parameters for the optimization phase. A methodology for 3D description of spatial distribution of material properties based on a random field models was developed and validated by experiments. Homogenized material models on multiple levels of the SOFC stack were...

  3. Heteroplasmon hybridization in stacked complementary plasmo-photonic crystals.

    Science.gov (United States)

    Iwanaga, Masanobu; Choi, Bongseok

    2015-03-11

    We constructed plasmo-photonic crystals in which efficient light-trapping, plasmonic resonances couple with photonic guided resonances of large density of states and high-quality factor. We have numerically and experimentally shown that heteroplasmon hybrid modes emerge in stacked complementary (SC) plasmo-photonic crystals. The resonant electromagnetic-field distributions evidence that the two hybrid modes originate from two different heteroplasmons, exhibiting a large energy splitting of 300 meV. We further revealed a series of plasmo-photonic modes in the SC crystals.

  4. Pressurized Operation of a Planar Solid Oxide Cell Stack

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Sun, Xiufu; Ebbesen, Sune Dalgaard

    2016-01-01

    Solid oxide cells (SOCs) can be operated either as fuel cells (SOFC) to convert fuels to electricity or as electrolyzers (SOEC) to convert electricity to fuels such as hydrogen or methane. Pressurized operation of SOCs provide several benefits on both cell and system level. If successfully matured...... (electrode performance) increases for thermodynamic and kinetic reasons, respectively. Further, the summit frequency of the gas concentration impedance arc and the pressure difference across the stack and heat exchangers is seen to decrease with increasing pressure following a power-law expression. Finally...

  5. Stacking fault tetrahedra formation in the neighbourhood of grain boundaries

    CERN Document Server

    Samaras, M; Van Swygenhoven, H; Victoria, M

    2003-01-01

    Large scale molecular dynamics computer simulations are performed to study the role of the grain boundary (GB) during the cascade evolution in irradiated nanocrystalline Ni. At all primary knock-on atom (PKA) energies in cascades near GBs, the damage produced after cooling down is vacancy dominated. Truncated stacking fault tetrahedra (TSFTs) are easily formed at 10 keV and higher PKA energies. At the higher energies a complex partial dislocation network forms, consisting of TSFTs. The GB acts as an interstitial sink without undergoing major structural changes.

  6. Nanocomposite Materials of Alternately Stacked C60 Monolayer and Graphene

    International Nuclear Information System (INIS)

    Ishikawa, M.; Miura, K.; Kamiya, S.; Yoshimoto, S.; Suzuki, M.; Kuwahara, D.; Sasaki, N.

    2010-01-01

    We synthesized the novel nanocomposite consisting alternately of a stacked single graphene sheet and a C 60 monolayer by using the graphite intercalation technique in which alkylamine molecules help intercalate large C 60 molecules into the graphite. Moreover, it is found that the intercalated C 60 molecules can rotate in between single graphene sheets by using C 13 NMR measurements. This preparation method provides a general way for intercalating huge fullerene molecules into graphite, which will lead to promising materials with novel mechanical, physical, and electrical properties.

  7. Nanocomposite Materials of Alternately Stacked C60 Monolayer and Graphene

    Directory of Open Access Journals (Sweden)

    Makoto Ishikawa

    2010-01-01

    Full Text Available We synthesized the novel nanocomposite consisting alternately of a stacked single graphene sheet and a C60 monolayer by using the graphite intercalation technique in which alkylamine molecules help intercalate large C60 molecules into the graphite. Moreover, it is found that the intercalated C60 molecules can rotate in between single graphene sheets by using C13 NMR measurements. This preparation method provides a general way for intercalating huge fullerene molecules into graphite, which will lead to promising materials with novel mechanical, physical, and electrical properties.

  8. Broken sublattice symmetry states in Bernal stacked multilayer graphene

    Science.gov (United States)

    Yoon, Chiho; Jang, Yunsu; Jung, Jeil; Min, Hongki

    2017-06-01

    We analyze the ordered phases of Bernal stacked multilayer graphene in the presence of interaction induced band gaps due to sublattice symmetry breaking potentials, whose solutions can be analyzed in terms of light-mass and heavy-mass pseudospin doublets which have the same Chern numbers but opposite charge polarization directions. The application of a perpendicular external electric field reveals an effective Hund’s rule for the ordering of the sublattice pseudospin doublets in a tetralayer, while a similar but more complex phase diagram develops with increasing layer number.

  9. Improved DNA clamps by stacking to adjacent nucleobases

    DEFF Research Database (Denmark)

    Fatthalla, M.I.; Pedersen, Erik Bjerregaard

    2012-01-01

    Three or four aromatic rings interconnected by acetylene bridges form a stiff conjugated system with sufficient conformational freedom to make it useful to link together the two strands of a DNA clamp. Upon targeting a ssDNA, the conformational flexibility allows better stacking of the linker...... to the underlying non-planar base triplet in the formed triplex. This type of triplexes has a substantially higher thermal melting temperature which can be further improved by inserting locked nucleic acids (LNAs) in the Hoogsteen part of the clamp. An extremely high sensitivity to mismatches is observed...

  10. Some experience with measurements of stack releases and their correlation with environmental measurements

    International Nuclear Information System (INIS)

    Czarnecki, J.

    1988-01-01

    The first nuclear power plants (NPP) in Switzerland were built during the late 1960s and the early 1970s (PWR-Beznau and BWR-Muhleberg). A new generation of NPPs were built ten years later (PWR-Goesgen and BWR-Leibstadt). In all these NPP special attention was given to the sampling and measurements of the releases of radioactive materials, in particular long lived aerosols and J-131. The sampling systems at the Swiss NPP were originally installed on the basis of the American National Standard Guide to sampling Airborne Radioactive Materials in Nuclear Facilities, (ANSI NI3, 1 - 1969) or equivalent standards such as ISO 2889 and DIN 25423. Unfortunately, the sampling systems described in these guides cover only that fraction of radioactive aerosols, which is preferentially retained in various portions of the respiratory tract (0.3 to 10 Μm). In a NPP one can expect during an accident a very wide range of particles with diameters as large as 100 and more Μm, which can be transported away by the stack effluent and may not be properly sampled and measured. It should be taken into account that there are some non filtered rooms and that filters can fail or even break. Such particles when released cause a ground contamination in the vicinity of the plant. Such an event occurred in September 1986 in the NPP-Muhleberg

  11. Evaluation of a stack: A concrete chimney with brick liner

    International Nuclear Information System (INIS)

    Joshi, J.R.; Amin, J.A.; Porthouse, R.A.

    1995-01-01

    A 200 ft. tall stack, consisting of a concrete chimney with an independent acid proof brick liner built in the 1950's, serving the Separations facility at the Savannah River Site (SRS), was evaluated for the performance category 3 (PC3) level of Natural Phenomena Hazards (NPH) effects. The inelastic energy absorption capacity of the concrete chimney was considered in the evaluation of the earthquake resistance, in particular, to compute the F μ factor. The calculated value of F μ exceeded 3.0, while the seismic demand for the PC3 level, using an F μ value of 1.5, was found to be less than the capacity of the concrete chimney. The capacity formulation of ACI 307 was modified to incorporate the effect of an after design opening on the tension side. There are considerable uncertainties in determining the earthquake resistance of the independent brick liner. The critical liner section, located at the bottom of the breeching opening, does not meet the current recommendations. A discussion is provided for the possible acceptable values for the ''Moment Reduction Factor'', R w or F μ for the liner. Comments are provided on the comparison of stack demands using response spectra (RS) versus time history (TH) analysis, with and without soil structure interaction (SSI) effects

  12. Enhancing THz Absorption using Thin-Film Multilayer Stacks

    Science.gov (United States)

    Grbovic, Dragoslav; Bolakis, Christos; Karunasiri, Gamani

    2010-03-01

    Terahertz imaging has seen significant proliferation in recent years. This band of electromagnetic spectrum has been underutilized for a long time due to the lack of sufficiently powerful sources and sensitive detectors. Because of virtually harmless effects on living tissue, terahertz (THz) radiation is attractive for various applications, ranging from non-invasive medical diagnostics to detection of concealed weapons. Our work focuses on identifying materials, or more specifically a stack of thin-films with increased absorption in the band of interest. In this work, we demonstrate a method that combines finite element modeling, thin-film deposition and experimental characterization to create highly-absorptive multi-layer stacks. Finite element modeling is used to simulate the absorption of a combination of thin dielectric and metallic films. Metals are deposited using e-beam evaporation and dielectric films using plasma enhanced chemical vapor deposition (PECVD). The simulated and measured THz absorption characteristics of the composite thin-film multilayer stacts will be presented.

  13. Uniqueness of magnetotomography for fuel cells and fuel cell stacks

    International Nuclear Information System (INIS)

    Lustfeld, H; Hirschfeld, J; Reissel, M; Steffen, B

    2009-01-01

    The criterion for the applicability of any tomographic method is its ability to construct the desired inner structure of a system from external measurements, i.e. to solve the inverse problem. Magnetotomography applied to fuel cells and fuel cell stacks aims at determining the inner current densities from measurements of the external magnetic field. This is an interesting idea since in those systems the inner electric current densities are large, several hundred mA per cm 2 and therefore relatively high external magnetic fields can be expected. Still the question remains how uniquely the inverse problem can be solved. Here we present a proof that by exploiting Maxwell's equations extensively the inverse problem of magnetotomography becomes unique under rather mild assumptions and we show that these assumptions are fulfilled in fuel cells and fuel cell stacks. Moreover, our proof holds true for any other device fulfilling the assumptions listed here. Admittedly, our proof has one caveat: it does not contain an estimate of the precision requirements the measurements need to fulfil for enabling reconstruction of the inner current densities from external magnetic fields.

  14. Longitudinal ultrasonic vibration assisted guillotining of stacked paper.

    Science.gov (United States)

    Deibel, Karl-Robert; Kaiser, Fabian; Zimmermann, Remo; Meier, Linus; Bolt, Peter; Wegener, Konrad

    2014-08-01

    Ultrasonic vibration assisted cutting is a complex process with high dynamics. The interaction between cutting tool and workpiece is of key interest to understand the entire process. Experimental investigations are limited by the dynamics of the measurement system, and thus appropriately modeling of the ultrasonic vibration assisted cutting process is essential. In this investigation, a dynamic model regarding the ultrasonic vibration assisted guillotining of stacked paper sheets is developed. A Kelvin-Voigt material model, representing the individual sheets, is chosen, with its stiffness and damping parameters being empirically determined. A novel measurement strategy for studying the contact time and interaction between cutting tool and workpiece is introduced. It allows the verification of the highly dynamic behavior of the developed model. With the dynamic model, the experimentally observed cutting forces can be calculated. It is found that the dynamic forces cause a quicker failure of the material, which leads to a lower compression of the stack prior to reaching the critical cutting force. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Low hydrostatic head electrolyte addition to fuel cell stacks

    Science.gov (United States)

    Kothmann, Richard E.

    1983-01-01

    A fuel cell and system for supply electrolyte, as well as fuel and an oxidant to a fuel cell stack having at least two fuel cells, each of the cells having a pair of spaced electrodes and a matrix sandwiched therebetween, fuel and oxidant paths associated with a bipolar plate separating each pair of adjacent fuel cells and an electrolyte fill path for adding electrolyte to the cells and wetting said matrices. Electrolyte is flowed through the fuel cell stack in a back and forth fashion in a path in each cell substantially parallel to one face of opposite faces of the bipolar plate exposed to one of the electrodes and the matrices to produce an overall head uniformly between cells due to frictional pressure drop in the path for each cell free of a large hydrostatic head to thereby avoid flooding of the electrodes. The bipolar plate is provided with channels forming paths for the flow of the fuel and oxidant on opposite faces thereof, and the fuel and the oxidant are flowed along a first side of the bipolar plate and a second side of the bipolar plate through channels formed into the opposite faces of the bipolar plate, the fuel flowing through channels formed into one of the opposite faces and the oxidant flowing through channels formed into the other of the opposite faces.

  16. Complete intrinsic coincident polarimetry using stacked organic photovoltaics

    Science.gov (United States)

    Gupta Roy, S.; Awartani, O. M.; Sen, P.; O'Connor, B. T.; Kudenov, M. W.

    2015-09-01

    Measuring the 2 dimensional Stokes vector, to determine the polarization state of light, finds application in multiple areas, including the characterization of aerosol size distributions, target identification, quality control by evaluating the distribution of stress birefringence, resolving data channels in telecommunications, and for evaluating biological tissues in medical imaging. Conventional methods, such as channeled and division of focal plane polarimeters, usually limit spatial resolution, while others, like division of aperture or division of amplitude polarimeters, have higher complexity and less compactness. To help solve these issues, we have developed a system that uses semitransparent organic photovoltaics (OPVs) as photodetectors. The active area of the devices consist of biaxially oriented polymer films, which enables the device to preferentially absorb certain polarized states of incident light, depending on the orientation of the polymer chains. Taking advantage of the cells' transparency and ease of processing, compared to inorganic materials, enables multiple devices to be "stacked" along the optical axis. Presently, experiments have been conducted to detect linear polarization states of light. We use three stacked OPVs, where each device can measure one of the first three Stokes parameters simultaneously, thereby ensuring high spatial and temporal resolution with inherent spatial registration. In this paper, the fabrication of the OPVs and the design and calibration technique is documented, along with experimental data, supporting the hypothesis.

  17. Interface band alignment in high-k gate stacks

    Science.gov (United States)

    Eric, Bersch; Hartlieb, P.

    2005-03-01

    In order to successfully implement alternate high-K dielectric materials into MOS structures, the interface properties of MOS gate stacks must be better understood. Dipoles that may form at the metal/dielectric and dielectric/semiconductor interfaces make the band offsets difficult to predict. We have measured the conduction and valence band densities of states for a variety MOS stacks using in situ using inverse photoemission (IPE) and photoemission spectroscopy (PES), respectively. Results obtained from clean and metallized (with Ru or Al) HfO2/Si, SiO2/Si and mixed silicate films will be presented. IPE indicates a shift of the conduction band minimum (CBM) to higher energy (i.e. away from EF) with increasing SiO2. The effect of metallization on the location of band edges depends upon the metal species. The addition of N to the dielectrics shifts the CBM in a way that is thickness dependent. Possible mechanisms for these observed effects will be discussed.

  18. Stacking fault tetrahedron induced plasticity in copper single crystal

    International Nuclear Information System (INIS)

    Zhang, Liang; Lu, Cheng; Tieu, Kiet; Su, Lihong; Zhao, Xing; Pei, Linqing

    2017-01-01

    Stacking fault tetrahedron (SFT) is the most common type of vacancy clustered defects in fcc metals and alloys, and can play an important role in the mechanical properties of metallic materials. In this study, molecular dynamics (MD) simulations were carried out to investigate the incipience of plasticity and the underlying atomic mechanisms in copper single crystals with SFT. Different deformation mechanisms of SFT were reported due to the crystal orientations and loading directions (compression and tension). The results showed that the incipient plasticity in crystals with SFT resulted from the heterogeneous dislocation nucleation from SFT, so the stress required for plastic deformation was less than that needed for perfect single crystals. Three crystal orientations ([1 0 0], [1 1 0] and [1 1 1]) were specified in this study because they can represent most of the typical deformation mechanisms of SFT. MD simulations revealed that the structural transformation of SFT was frequent under the applied loading; a metastable SFT structure and the collapse of SFT were usually observed. The structural transformation resulted in a different reduction of yield stress in compression and tension, and also caused a decreased or reversed compression/tension asymmetry. Compressive stress can result in the unfaulting of Frank loop in some crystal orientations. According to the elastic theory of dislocation, the process of unfaulting was closely related to the size of the dislocation loop and the stacking fault energy.

  19. Hyperspectral anomaly detection based on stacked denoising autoencoders

    Science.gov (United States)

    Zhao, Chunhui; Li, Xueyuan; Zhu, Haifeng

    2017-10-01

    Hyperspectral anomaly detection (AD) is an important technique of unsupervised target detection and has significance in real situations. Due to the high dimensionality of hyperspectral data, AD will be influenced by noise, nonlinear correlation of band, or other factors that lead to the decline of detection accuracy. To overcome this problem, a method of hyperspectral AD based on stacked denoising autoencoders (AE) (HADSDA) is proposed. Simultaneously, two different feature detection models, spectral feature (SF) and fused feature by clustering (FFC), are constructed to verify the effectiveness of the proposed algorithm. The SF detection model uses the SF of each pixel. The FFC detection model uses a similar set of pixels constructed by clustering and then fuses the set of pixels by the stacked denoising autoencoders algorithm (SDA). The SDA is an algorithm that can automatically learn nonlinear deep features of the image. Compared with other linear or nonlinear feature extraction methods, the detection result of the proposed algorithm is greatly improved. Experiment results show that the proposed algorithm is an excellent feature learning method and can achieve higher detection performance.

  20. Migration velocity analysis using pre-stack wave fields

    KAUST Repository

    Alkhalifah, Tariq Ali

    2016-08-25

    Using both image and data domains to perform velocity inversion can help us resolve the long and short wavelength components of the velocity model, usually in that order. This translates to integrating migration velocity analysis into full waveform inversion. The migration velocity analysis part of the inversion often requires computing extended images, which is expensive when using conventional methods. As a result, we use pre-stack wavefield (the double-square-root formulation) extrapolation, which includes the extended information (subsurface offsets) naturally, to make the process far more efficient and stable. The combination of the forward and adjoint pre-stack wavefields provides us with update options that can be easily conditioned to improve convergence. We specifically use a modified differential semblance operator to split the extended image into a residual part for classic differential semblance operator updates and the image (Born) modelling part, which provides reflections for higher resolution information. In our implementation, we invert for the velocity and the image simultaneously through a dual objective function. Applications to synthetic examples demonstrate the features of the approach.

  1. Stacking faults in a layered cobalt tellurium phosphate oxochloride

    Science.gov (United States)

    Zimmermann, Iwan; Johnsson, Mats

    2015-02-01

    The new compound Co2Te3(PO4)O6Cl was synthesized by chemical reactions in a sealed and evacuated silica tube. The crystal structure was solved from single crystal diffraction data and is made up by charge neutral layers. Within the layers two types of chains are made up by edge sharing [CoO6] and [CoO5Cl] polyhedra respectively. The chains are separated by tellurium oxide and phosphate building blocks. There are only weak Van der Waals interactions in between the layers and severe diffuse scattering is observed due to faulted stacking of the layers. Structure solutions in a P-1 triclinic cell and a larger monoclinic cell in P21/c are discussed and compared to a computer generated model. The reasons for the stacking faults may be due to that there are two positions available for each layer that results in similar connectivity to the next layer in addition to the relatively wide channels in between the layers that reduce the Van der Waals interactions in between them.

  2. Final Report - MEA and Stack Durability for PEM Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Yandrasits, Michael A.

    2008-02-15

    Proton exchange membrane fuel cells are expected to change the landscape of power generation over the next ten years. For this to be realized one of the most significant challenges to be met for stationary systems is lifetime, where 40,000 hours of operation with less than 10% decay is desired. This project conducted fundamental studies on the durability of membrane electrode assemblies (MEAs) and fuel cell stack systems with the expectation that knowledge gained from this project will be applied toward the design and manufacture of MEAs and stack systems to meet DOE’s 2010 stationary fuel cell stack systems targets. The focus of this project was PEM fuel cell durability – understanding the issues that limit MEA and fuel cell system lifetime, developing mitigation strategies to address the lifetime issues and demonstration of the effectiveness of the mitigation strategies by system testing. To that end, several discoveries were made that contributed to the fundamental understanding of MEA degradation mechanisms. (1) The classically held belief that membrane degradation is solely due to end-group “unzipping” is incorrect; there are other functional groups present in the ionomer that are susceptible to chemical attack. (2) The rate of membrane degradation can be greatly slowed or possibly eliminated through the use of additives that scavenge peroxide or peroxyl radicals. (3) Characterization of GDL using dry gases is incorrect due to the fact that fuel cells operate utilizing humidified gases. The proper characterization method involves using wet gas streams and measuring capillary pressure as demonstrated in this project. (4) Not all Platinum on carbon catalysts are created equally – the major factor impacting catalyst durability is the type of carbon used as the support. (5) System operating conditions have a significant impact of lifetime – the lifetime was increased by an order of magnitude by changing the load profile while all other variables remain

  3. Air-Cooled Stack Freeze Tolerance Freeze Failure Modes and Freeze Tolerance Strategies for GenDriveTM Material Handling Application Systems and Stacks Final Scientific Report

    Energy Technology Data Exchange (ETDEWEB)

    Hancock, David, W.

    2012-02-14

    Air-cooled stack technology offers the potential for a simpler system architecture (versus liquid-cooled) for applications below 4 kilowatts. The combined cooling and cathode air allows for a reduction in part count and hence a lower cost solution. However, efficient heat rejection challenges escalate as power and ambient temperature increase. For applications in ambient temperatures below freezing, the air-cooled approach has additional challenges associated with not overcooling the fuel cell stack. The focus of this project was freeze tolerance while maintaining all other stack and system requirements. Through this project, Plug Power advanced the state of the art in technology for air-cooled PEM fuel cell stacks and related GenDrive material handling application fuel cell systems. This was accomplished through a collaborative work plan to improve freeze tolerance and mitigate freeze-thaw effect failure modes within innovative material handling equipment fuel cell systems designed for use in freezer forklift applications. Freeze tolerance remains an area where additional research and understanding can help fuel cells to become commercially viable. This project evaluated both stack level and system level solutions to improve fuel cell stack freeze tolerance. At this time, the most cost effective solutions are at the system level. The freeze mitigation strategies developed over the course of this project could be used to drive fuel cell commercialization. The fuel cell system studied in this project was Plug Power's commercially available GenDrive platform providing battery replacement for equipment in the material handling industry. The fuel cell stacks were Ballard's commercially available FCvelocity 9SSL (9SSL) liquid-cooled PEM fuel cell stack and FCvelocity 1020ACS (Mk1020) air-cooled PEM fuel cell stack.

  4. High thermal stability in W/MgO/CoFeB/W/CoFeB/W stacks via ultrathin W insertion with perpendicular magnetic anisotropy

    Science.gov (United States)

    Liu, Yi; Yu, Tao; Zhu, Zhengyong; Zhong, Huicai; Khamis, Khamis Masoud; Zhu, Kaigui

    2016-07-01

    The perpendicular magnetic anisotropy (PMA) of a series of top MgO/CoFeB/W stacks were studied. In these stacks, the thickness of CoFeB is limited in a range of 1.1-2.2 nm. It was found that the stack can still maintain PMA in a 1.9 nm thick CoFeB free layer. Besides, we investigated the thermal stability factor ∆ of a spin transfer torque magnetic random access memory (STT-MRAM) by inserting an ultra-thin W film of 0.8 nm between two CoFeB films. The result shows a clear PMA behavior for the samples with CoFeB thickness up to 2.5 nm, and an in-plane magnetic anisotropy (IMA) when the CoFeB is thicker than 2.5 nm. Moreover, the thermal stability factor ∆ of the CoFeB stack with W insertion is about 132 for a 50 nm size STT-MRAM device, which is remarkably improved compared to 112 for a sample without W insertion. Our results represent an alternative way to realize the endurance at high annealing temperature, high-density and high ∆ in STT-MRAM device by ultra-thin W insertion.

  5. Slip-stacking Dynamics for High-Power Proton Beams at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, Jeffrey Scott [Indiana Univ., Bloomington, IN (United States)

    2015-12-01

    Slip-stacking is a particle accelerator configuration used to store two particle beams with different momenta in the same ring. The two beams are longitudinally focused by two radiofrequency (RF) cavities with a small frequency difference between them. Each beam is synchronized to one RF cavity and perturbed by the other RF cavity. Fermilab uses slip-stacking in the Recycler so as to double the power of the 120 GeV proton beam in the Main Injector. This dissertation investigates the dynamics of slip-stacking beams analytically, numerically and experimentally. In the analytic analysis, I find the general trajectory of stable slip-stacking particles and identify the slip-stacking parametric resonances. In the numerical analysis, I characterize the stable phase-space area and model the particle losses. In particular, I evaluate the impact of upgrading the Fermilab Booster cycle-rate from 15 Hz to 20 Hz as part of the Proton Improvement Plan II (PIP-II). The experimental analysis is used to verify my approach to simulating slip-stacking loss. I design a study for measuring losses from the longitudinal single-particle dynamics of slip-stacking as a function of RF cavity voltage and RF frequency separation. I further propose the installation of a harmonic RF cavity and study the dynamics of this novel slip-stacking configuration. I show the harmonic RF cavity cancels out parametric resonances in slip-stacking, reduces emittance growth during slip-stacking, and dramatically enhances the stable phase-space area. The harmonic cavity is expected to reduce slip-stacking losses to far exceed PIP-II requirements. These results raise the possibility of extending slip-stacking beyond the PIP-II era.

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

    Science.gov (United States)

    2010-06-02

    This report covers efforts by the Hawaii Natural Energy Institute (HNEI) of the University of Hawaii under the ONR-funded Ion Tiger UAV award that included testing of Ion Tiger fuel cell stacks in HNEI’s Hawaii Fuel Cell Test Facility located in Honolulu, Hawaii. Work was focused on steady-state stack characteristics of Protonex fuel cell stacks under various operating conditions. In addition, Hardware-in-the-Loop testing was performed to characterize dynamic

  7. Improved solid oxide fuel cell stacks: Power density, durability and modularity. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lund Frandsen, H.; Kiebach, W.R.; Hoeegh, J. (Technical Univ. of Denmark. Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)) (and others)

    2010-10-15

    This report presents the work performed within the project PSO2009-1-10207 during the period from 01-04-2009 - 31-06-2010. The report is divided into three parts covering the three work packages: Stack components; Stacks and durability; and Large SOFC systems: modularity and scalability. The project contains 38 milestones and all milestones in the project have been either fully or partly fulfilled. Two major achievements within this project concern the robustness towards dynamic operations and implementation of cells with more active cathodes: Within this project tools to evaluate and test SOFC stacks with respect to robustness during dynamic operations has been developed. From stack tests performed under dynamic conditions it was observed that the effect on degradation and failure seemed to be very little. The thermo-mechanical models developed in this project in combination with the dynamic stack model was used in combination to understand why. The results clearly showed that the hardest stress field applied to the cells arises from the steady state operating point rather than from the dynamic conditions. This is a very promising result concerning the fact that especially small CHP units in a commercial system will experience dynamic conditions from load cycling and thermal cycling. A new type of cell with a more active cathode has been formulated and introduced into the TOFC stacks in this project. The aim was to improve the effect of the stack by 25 %. However, compared to a standard stack with the ''old'' cells, the stack effect was increased by 44% - from a cross flow stack with standard 2G cells to a cross flow stack with 2.5G cells. The new type of cells also show an excellent stability towards moisture in the cathode feed, and a stack with 2.5G cells has been tested for 12.000 hrs with a degradation rate of 30 mOMEGAcm2/1000 hr. (Author)

  8. Stacking fault growth of FCC crystal: The Monte-Carlo simulation approach

    International Nuclear Information System (INIS)

    Jian Jianmin; Ming Naiben

    1988-03-01

    The Monte-Carlo method has been used to simulate the growth of the FCC (111) crystal surface, on which is presented the outcrop of a stacking fault. The comparison of the growth rates has been made between the stacking fault containing surface and the perfect surface. The successive growth stages have been simulated. It is concluded that the outcrop of stacking fault on the crystal surface can act as a self-perpetuating step generating source. (author). 7 refs, 3 figs

  9. Nucleoelectric plants technical memory

    International Nuclear Information System (INIS)

    Araujo Pereira, Alvaro de

    1991-01-01

    The work explains the basic norms that establish the guidelines to the Technical Memory elaboration of this electrical energy sector - the nucleoelectric plants. It guides the technicians who execute the Technical Memory of the plants, exposing the items that may compose the work: contents: introduction, planning, proposition, equipment and materials supply, construction, commissioning, commercial actions, budget, financing and costs; generalities: drawings and photographies, monetary references, terminology, system units, management, graphic guide project, responsible staff, a summarized technical card and illustrations

  10. Planar SOFC technology: stack design and development for lower cost and manufacturability

    Energy Technology Data Exchange (ETDEWEB)

    Pyke, S.H.; Howard, P.J.; Leah, R.T.

    2002-07-01

    This report summarises the results of a project to examine the performance of an externally manifolded solid oxide fuel cell (SOFC) stack based on a planar, anode-supported cells geometry, and to develop sealing materials and a design for a SOFC stack for potential low cost manufacture. The testing of short stacks, the development of innovative glass-ceramic sealing materials, and the development of an SOFC model to assess cell performance are described along with the development of a new stack geometry based on an internally manifolded geometry.

  11. Exact and heuristic solutions to the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann; Archetti, Claudia; Madsen, Oli B.G.

    The double travelling salesman problem with multiple stacks (DTSPMS) is a pickup and delivery problem where pickups and deliveries are separated, such that all pickup operations are performed before the first delivery takes place. All operations are carried out by one vehicle and no reloading...... is allowed. The vehicle provides several separated (horizontal) stacks/rows for the transportation of the orders, such that each stack is accessed using a LIFO principle, independently of the other stacks. In a real-life setting the dimensions of the problem is 33 orders each consisting of one euro...

  12. Power sources involving ~ 300W PEMFC fuel cell stacks cooled by different media

    Directory of Open Access Journals (Sweden)

    Dudek Magdalena

    2017-01-01

    Full Text Available Two constructions of ~300W PEMFC stacks, cooled by different media, were analysed. An open-cathode ~300W PEMFC stack cooled by air (Horizon, Singapore and a PEMFC F-42 stack cooled by a liquid medium (Schunk, Germany were chosen for all of the investigations described in this paper. The potential for the design and construction of power sources involving fuel cells, as well as of a hybrid system (fuel cell-lithium battery for mobile and stationary applications, is presented and discussed. The impact of certain experimental parameters on PEMFC stack performance is analysed and discussed.

  13. Testing and Evaluation of an Advanced High Performance Planar SOFC Stack

    National Research Council Canada - National Science Library

    Elangovan, S

    1999-01-01

    .... SOFCo has conducted several programs which synergistically address this objective: an internally funded program focusing on stack development and system integration for pipeline natural gas (PNG...

  14. Stack Parameters Effect on the Performance of Anharmonic Resonator Thermoacoustic Heat Engine

    KAUST Repository

    Nouh, Mostafa A.

    2014-01-01

    A thermoacoustic heat engine (TAHE) converts heat into acoustic power with no moving parts. It exhibits several advantages over traditional engines, such as simple design, stable functionality, and environment-friendly working gas. In order to further improve the performance of TAHE, stack parameters need to be optimized. Stack\\'s position, length and plate spacing are the three main parameters that have been investigated in this study. Stack\\'s position dictates both the efficiency and the maximum produced acoustic power of the heat engine. Positioning the stack closer to the pressure anti-node might ensure high efficiency on the expense of the maximum produced acoustic power. It is noticed that the TAHE efficiency can further be improved by spacing the plates of the stack at a value of 2.4 of the thermal penetration depth, δk . Changes in the stack length will not affect the efficiency much as long as the temperature gradient across the stack, as a ratio of the critical temperature gradient ψ is more than 1. Upon interpreting the effect of these variations, attempts are made towards reaching the engine\\'s most powerful operating point.

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

    Science.gov (United States)

    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.

  16. Very Weak Signals (VWS detected by stacking method according to different astronomical periodicities (HiCum

    Directory of Open Access Journals (Sweden)

    M. van Ruymbeke

    2007-11-01

    Full Text Available A stacking method to detect very weak signals is introduced in this paper. This method is to stack observed data in different well known periodicities according to the astronomical clock since majority geophysical observations are time based. We validated this method by applying it in four different cases. Interactions behind the observed parameters become obviously after it is stacked in two diurnal and semidiurnal tidal periodical waves. Amplitude and phase variations will be also measurable when a sliding windows stacking is used. This could be an important reference to find precursors before some earthquakes and volcanic events, corresponding to attenuations of medium patterns.

  17. Plume trajectory formation under stack tip self-enveloping

    Science.gov (United States)

    Gribkov, A. M.; Zroichikov, N. A.; Prokhorov, V. B.

    2017-10-01

    The phenomenon of stack tip self-enveloping and its influence upon the conditions of plume formation and on the trajectory of its motion are considered. Processes are described occurring in the initial part of the plume while the interaction between vertically directed flue gases outflowing from the stack and a horizontally directed moving air flow at high wind velocities that lead to the formation of a flag-like plume. Conditions responsible for the origin and evolution of interaction between these flows are demonstrated. For the first time, a plume formed under these conditions without bifurcation is registered. A photo image thereof is presented. A scheme for the calculation of the motion of a plume trajectory is proposed, the quantitative characteristics of which are obtained based on field observations. The wind velocity and direction, air temperature, and atmospheric turbulence at the level of the initial part of the trajectory have been obtained based on data obtained from an automatic meteorological system (mounted on the outer parts of a 250 m high stack no. 1 at the Naberezhnye Chelny TEPP plant) as well as based on the results of photographing and theodolite sighting of smoke puffs' trajectory taking into account their velocity within its initial part. The calculation scheme is supplemented with a new acting force—the force of self-enveloping. Based on the comparison of the new calculation scheme with the previous one, a significant contribution of this force to the development of the trajectory is revealed. A comparison of the natural full-scale data with the results of the calculation according to the proposed new scheme is made. The proposed calculation scheme has allowed us to extend the application of the existing technique to the range of high wind velocities. This approach would make it possible to simulate and investigate the trajectory and full rising height of the calculated the length above the mouth of flue-pipes, depending on various modal

  18. Venous Sampling

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Venous sampling Venous sampling is a diagnostic procedure that uses ... the limitations of venous sampling? What is venous sampling? Venous sampling is a diagnostic procedure that involves ...

  19. Availability Analysis of the Ventilation Stack CAM Interlock System

    International Nuclear Information System (INIS)

    YOUNG, J.

    2000-01-01

    Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability. Further, requiring an alarm to actuate upon CAM failure is not necessary to maintain the availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability. However, if CAM failures were only detected by the 92-day functional tests required in the Authorization Basis (AB), CAM availability would be much less than that credited in the safety analysis. Therefore it is recommended that the current surveillance practice of daily simple system checks, 30-day source checks and 92-day functional tests be continued in order to maintain CAM availability

  20. Multi-channel temperature measurement system for automotive battery stack

    Science.gov (United States)

    Lewczuk, Radoslaw; Wojtkowski, Wojciech

    2017-08-01

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