NURE aerial gamma-ray and magnetic reconnaissance survey: Colorado-Arizona area, Salton Sea NI 11-9, El Centro NI 11-12, Phoenix NI 12-7, Ajo NI 12-10, Lukeville NH 12-1 quadrangles

International Nuclear Information System (INIS)

1979-11-01

Volume II contains the geologic base map, flight path map, anomaly maps (uranium, thorium, potassium, uranium/thorium, uranium/potassium, thorium/potassium), radiometric multiple-parameter stacked profiles, magnetic and ancillary stacked profile data, and histograms

NURE aerial gamma-ray and magnetic reconnaissance survey of Maine and portions of New York. Final report

International Nuclear Information System (INIS)

1981-07-01

Volume II contains the flight line base map, anomaly maps (uranium, thorium, potassium, uranium/thorium, uranium/potassium, thorium/potassium), total count map, magnetic field map, uranium map, thorium map, potassium map, ratio maps for uranium/thorium, uranium/potassium, thorium/potassium, radiometric multiple-parameter stacked profiles, magnetic and ancillary stacked profile data, and histograms

NURE aerial gamma-ray and magnetic reconnaissance survey of Maine and portions of New York. Final report

International Nuclear Information System (INIS)

1981-07-01

Volume II contains the flight line base maps, anomaly maps (uranium, thorium, potassium, uranium/thorium, uranium/potassium, thorium/potassium), total count maps, magnetic field maps, uranium maps, thorium maps, potassium maps, ratio maps for U/T, U/K, T/K, radiometric multiple-parameter stacked profiles, magnetic and ancillary stacked profile data, and histograms

NURE aerial gamma-ray and magnetic reconnaissance survey of Maine and portions of New York. Final report

International Nuclear Information System (INIS)

1981-07-01

Volume II contains the flight line base map, anomaly maps (uranium, thorium, potassium, uranium/thorium, uranium/potassium, thorium/potassium), total count map, magnetic field map, uranium map, thorium map, potassium map, ratio maps for U/T, U/K, T/K, radiometric multiple-parameter stacked profiles, magnetic and ancillary stacked profile data, and histograms

NURE aerial gamma-ray and magnetic reconnaissance survey of Maine and portions of New York. Final report

International Nuclear Information System (INIS)

1981-06-01

Volume II contains the flight path maps, anomaly maps (uranium, thorium, potassium, uranium/thorium, uranium/potassium, thorium/potassium), radiometric multiple-parameter stacked profiles, magnetic and ancillary stacked profile data, histograms, total count maps, magnetic field maps, uranium maps, thorium maps, potassium maps, ratio maps for U/T, U/K, and T/K

NURE aerial gamma-ray and magnetic reconnaissance survey of Maine and portions of New York. Final report

International Nuclear Information System (INIS)

1981-06-01

Volume II contains the flight line base maps, anomaly maps (urnaium, thorium, potassium, uranium/thorium, uranium/potassium, thorium/potassium), radiometric multiple-parameter stacked profiles, magnetic and ancillary stacked profile data, histograms, total count maps, magnetic field maps, uranium maps, thorium maps, potassium maps, ratio maps for U/T, U/K, and T/K

NURE aerial gamma-ray and magnetic reconnaissance survey of Maine and portions of New York. Final report

International Nuclear Information System (INIS)

1981-07-01

Volume II contains the flight line base map anomaly maps (uranium, thorium, potassium, uranium/thorium, uranium/potassium, thorium/potassium), total count map, magnetic field map, uranium map, thorium map, potassium map, ratio maps for uranium/thorium, uranium/potassium, thorium/potassium, radiometric multiple-parameter stacked profiles, magnetic and ancillary stacked profile data, and histograms

NURE aerial gamma-ray and magnetic reconnaissance survey of Maine and portions of New York. Final report

International Nuclear Information System (INIS)

1981-07-01

Volume II contains the flight line base map, anomaly maps (uranium, thorium, potassium, uranium/thorium, uranium/potassium, thorium/potassium), radiometric multiple-parameter stacked profiles, magnetic and ancillary stacked profile data, histograms, total count map, magnetic field map, uranium map, thorium map, potassium map, ratio maps for U/T, U/K, and T/K

NURE aerial gamma-ray and magnetic reconnaissance survey of Maine and portions of New York. Final report

International Nuclear Information System (INIS)

1981-06-01

Volume II contains the flight line base map, anomaly maps (uranium, thorium, potassium, uranium/thorium, uranium/potassium, thorium/potassium), total count map, potassium map, ratio maps for uranium/thorium, uranium/potassium, thorium/potassium, radiometric multiple-parameter stacked profiles, magnetic and ancillary stacked profile data, and histograms

NURE aerial gamma-ray and magnetic detail survey: Gleason Mtn., Washington-Idaho area. Final report

International Nuclear Information System (INIS)

1981-05-01

Volume II contains the following: flight line base map; magnetic contour map, maps for uranium, thorium, potassium, thorium/potassium, uranium/potassium; multi-variate analysis map; geochemical analysis map; radiometric multiple parameter stacked profiles; magnetic and ancillary stacked profile data; statistical summaries and histograms for uranium, thorium, potassium, uranium/potassium, uranium/thorium, and thorium/potassium

NURE aerial gamma-ray and magnetic detail survey: Spirit Pluton, Washington area. Final report

International Nuclear Information System (INIS)

1981-06-01

Volume II contains the following: flight line base map; magnetic contour map; maps for uranium, thorium, potassium, uranium/thorium, thorium/potassium, uranium/potassium; multi-variate analysis map; geochemical analysis map; radiometric multiple parameter stacked profiles; magnetic and concillary stacked profile data; statistical summary and histograms for uranium, thorium, potassium, uranium/potassium, uranium/thorium, and thorium/potassium

NURE aerial gamma-ray and magnetic detail survey: W. Fork Sampoil River, Washington area. Final report

International Nuclear Information System (INIS)

1981-05-01

Volume II contains the following: flight line base maps; magnetic contour maps; maps for uranium, thorium, potassium, uranium/thorium, thorium/potassium, uranium/potassium; multi-variate analysis maps; geochemical analysis maps; radiometric multiple parameter stacked profiles; magnetic and ancillary stacked profile data; histograms and statistical summaries for potassium, uranium, thorium, uranium/potassium, uranium/thorium, and thorium/potassium

NURE aerial gamma-ray and magnetic detail survey: Chelan, Washington area. Final report

International Nuclear Information System (INIS)

1981-06-01

Volume II contains the flight line base map, magnetic contour map, maps for uranium, thorium, potassium, uranium/thorium, thorium/potassium, uranium/potassium, multi-variate analysis map, geochemical analysis map, radiometric multiple parameter stacked profiles, magnetic and ancillary stacked profile data, multi-variate histograms and statistical summaries for potassium, uranium, thorium, uranium/potassium, uranium/thorium, thorium/potassium

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

International Nuclear Information System (INIS)

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

2015-01-01

The proton beam energy of an isochronous 18 MeV cyclotron was determined using a novel version of the stacked copper-foils technique. This simple method used stacked foils of natural copper forming ‘thick’ targets to produce Zn radioisotopes by the well-documented (p,x) monitor-reactions. Primary beam energy was calculated using the "6"5Zn activity vs. depth profile in the target, with the results obtained using "6"2Zn and "6"3Zn (as comparators) in close agreement. Results from separate measurements using foil thicknesses of 100, 75, 50 or 25 µm to form the stacks also concurred closely. Energy was determined by iterative least-squares comparison of the normalized measured activity profile in a target-stack with the equivalent calculated normalized profile, using ‘energy’ as the regression variable. The technique exploits the uniqueness of the shape of the activity vs. depth profile of the monitor isotope in the target stack for a specified incident energy. The energy using "6"5Zn activity profiles and 50-μm foils alone was 18.03±0.02 [SD] MeV (95%CI=17.98–18.08), and 18.06±0.12 MeV (95%CI=18.02–18.10; NS) when combining results from all isotopes and foil thicknesses. When the beam energy was re-measured using "6"5Zn and 50-μm foils only, following a major upgrade of the ion sources and nonmagnetic beam controls the results were 18.11±0.05 MeV (95%CI=18.00–18.23; NS compared with ‘before’). Since measurement of only one Zn monitor isotope is required to determine the normalized activity profile this indirect yet precise technique does not require a direct beam-current measurement or a gamma-spectroscopy efficiency calibrated with standard sources, though a characteristic photopeak must be identified. It has some advantages over published methods using the ratio of cross sections of monitor reactions, including the ability to determine energies across a broader range and without need for customized beam degraders. - Highlights: • Simple

Geophysical Data Sets in GeoMapApp

Science.gov (United States)

Goodwillie, A. M.

2017-12-01

GeoMapApp (http://www.geomapapp.org), a free map-based data tool developed at Lamont-Doherty Earth Observatory, provides access to hundreds of integrated geoscience data sets that are useful for geophysical studies. Examples include earthquake and volcano catalogues, gravity and magnetics data, seismic velocity tomographic models, geological maps, geochemical analytical data, lithospheric plate boundary information, geodetic velocities, and high-resolution bathymetry and land elevations. Users can also import and analyse their own data files. Data analytical functions provide contouring, shading, profiling, layering and transparency, allowing multiple data sets to be seamlessly compared. A new digitization and field planning portal allow stations and waypoints to be generated. Sessions can be saved and shared with colleagues and students. In this eLightning presentation we will demonstrate some of GeoMapApp's capabilities with a focus upon subduction zones and tectonics. In the attached screen shot of the Cascadia margin, the contoured depth to the top of the subducting Juan de Fuca slab is overlain on a shear wave velocity depth slice. Geochemical data coloured on Al2O3 and scaled on MgO content is shown as circles. The stack of data profiles was generated along the white line.

Observation of dopant-profile independent electron transport in sub-monolayer TiO{sub x} stacked ZnO thin films grown by atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Saha, D., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Misra, P., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Joshi, M. P.; Kukreja, L. M. [Laser Materials Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Das, Gangadhar [Indus Synchrotrons Utilisation Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

2016-01-18

Dopant-profile independent electron transport has been observed through a combined study of temperature dependent electrical resistivity and magnetoresistance measurements on a series of Ti incorporated ZnO thin films with varying degree of static-disorder. These films were grown by atomic layer deposition through in-situ vertical stacking of multiple sub-monolayers of TiO{sub x} in ZnO. Upon decreasing ZnO spacer layer thickness, electron transport smoothly evolved from a good metallic to an incipient non-metallic regime due to the intricate interplay of screening of spatial potential fluctuations and strength of static-disorder in the films. Temperature dependent phase-coherence length as extracted from the magnetotransport measurement revealed insignificant role of inter sub-monolayer scattering as an additional channel for electron dephasing, indicating that films were homogeneously disordered three-dimensional electronic systems irrespective of their dopant-profiles. Results of this study are worthy enough for both fundamental physics perspective and efficient applications of multi-stacked ZnO/TiO{sub x} structures in the emerging field of transparent oxide electronics.

Halo Pressure Profile through the Skew Cross-power Spectrum of the Sunyaev–Zel’dovich Effect and CMB Lensing in Planck

Energy Technology Data Exchange (ETDEWEB)

Timmons, Nicholas; Cooray, Asantha; Feng, Chang [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Keating, Brian [Department of Physics, University of California, San Diego, La Jolla, CA 92093 (United States)

2017-11-01

We measure the cosmic microwave background (CMB) skewness power spectrum in Planck , using frequency maps of the HFI instrument and the Sunyaev–Zel’dovich (SZ) component map. The two-to-one skewness power spectrum measures the cross-correlation between CMB lensing and the thermal SZ effect. We also directly measure the same cross-correlation using the Planck CMB lensing map and the SZ map and compare it to the cross-correlation derived from the skewness power spectrum. We model fit the SZ power spectrum and CMB lensing–SZ cross-power spectrum via the skewness power spectrum to constrain the gas pressure profile of dark matter halos. The gas pressure profile is compared to existing measurements in the literature including a direct estimate based on the stacking of SZ clusters in Planck .

Stacking fault density and bond orientational order of fcc ruthenium nanoparticles

Science.gov (United States)

Seo, Okkyun; Sakata, Osami; Kim, Jae Myung; Hiroi, Satoshi; Song, Chulho; Kumara, Loku Singgappulige Rosantha; Ohara, Koji; Dekura, Shun; Kusada, Kohei; Kobayashi, Hirokazu; Kitagawa, Hiroshi

2017-12-01

We investigated crystal structure deviations of catalytic nanoparticles (NPs) using synchrotron powder X-ray diffraction. The samples were fcc ruthenium (Ru) NPs with diameters of 2.4, 3.5, 3.9, and 5.4 nm. We analyzed average crystal structures by applying the line profile method to a stacking fault model and local crystal structures using bond orientational order (BOO) parameters. The reflection peaks shifted depending on rules that apply to each stacking fault. We evaluated the quantitative stacking faults densities for fcc Ru NPs, and the stacking fault per number of layers was 2-4, which is quite large. Our analysis shows that the fcc Ru 2.4 nm-diameter NPs have a considerably high stacking fault density. The B factor tends to increase with the increasing stacking fault density. A structural parameter that we define from the BOO parameters exhibits a significant difference from the ideal value of the fcc structure. This indicates that the fcc Ru NPs are highly disordered.

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.

Non-destructive spatial characterization of buried interfaces in multilayer stacks via two color picosecond acoustics

Science.gov (United States)

Faria, Jorge C. D.; Garnier, Philippe; Devos, Arnaud

2017-12-01

We demonstrate the ability to construct wide-area spatial mappings of buried interfaces in thin film stacks in a non-destructive manner using two color picosecond acoustics. Along with the extraction of layer thicknesses and sound velocities from acoustic signals, the morphological information presented is a powerful demonstration of phonon imaging as a metrological tool. For a series of heterogeneous (polymer, metal, and semiconductor) thin film stacks that have been treated with a chemical procedure known to alter layer properties, the spatial mappings reveal changes to interior thicknesses and chemically modified surface features without the need to remove uppermost layers. These results compare well to atomic force microscopy scans showing that the technique provides a significant advantage to current characterization methods for industrially important device stacks.

Depth Profiling of La2O3 ∕ HfO2 Stacked Dielectrics for Nanoelectronic Device Applications

KAUST Repository

Alshareef, Husam N.

2011-01-03

Nanoscale La2O3 /HfO2 dielectric stacks have been studied using high resolution Rutherford backscattering spectrometry. The measured distance of the tail-end of the La signal from the dielectric/Si interface suggests that the origin of the threshold voltage shifts and the carrier mobility degradation may not be the same. Up to 20% drop in mobility and 500 mV shift in threshold voltage was observed as the La signal reached the Si substrate. Possible reasons for these changes are proposed, aided by depth profiling and bonding analysis. © 2011 The Electrochemical Society.

Testing the sampling efficiency of a nuclear power station stack monitor

Energy Technology Data Exchange (ETDEWEB)

Stroem, L.H. [Instrumentinvest, Nykoeping (Sweden)

1997-08-01

The test method comprises the injection of known amounts of monodisperse particles in the stack air stream, at a suitable point upstream of the sampling installation. To find a suitable injection polls, the gas flow was mapped by means of a tracer gas, released in various points in the stack base. The resulting concentration distributions at the stack sampler level were observed by means of an array of gas detectors. An injection point that produced symmetrical distribution over the stack area, and low concentrations at the stack walls was selected for the particle tests. Monodisperse particles of 6, 10, and 19 {mu}m aerodynamic diameter, tagged with dysprosium, were dispersed in the selected injection point. Particle concentration at the sampler level was measured. The losses to the stack walls were found to be less than 10 %. The particle concentrations at the four sampler inlets were calculated from the observed gas distribution. The amount calculated to be aspirated into the sampler piping was compared with the quantity collected by the sampling train ordinary filter, to obtain the sampling line transmission efficiency. 1 ref., 2 figs.

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

Science.gov (United States)

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

2017-02-01

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

NOAA JPSS Ozone Mapping and Profiler Suite (OMPS) Version 8 Nadir Profile Ozone (V8Pro) Environmental Data Record (EDR) from NDE

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a high quality operational Environmental Data Record (EDR) of nadir profiler ozone from the Ozone Mapping and Profiling Suite (OMPS) instrument...

Subsurface Profile Mapping using 3-D Compressive Wave Imaging

Directory of Open Access Journals (Sweden)

Hazreek Z A M

2017-01-01

Full Text Available Geotechnical site investigation related to subsurface profile mapping was commonly performed to provide valuable data for design and construction stage based on conventional drilling techniques. From past experience, drilling techniques particularly using borehole method suffer from limitations related to expensive, time consuming and limited data coverage. Hence, this study performs subsurface profile mapping using 3-D compressive wave imaging in order to minimize those conventional method constraints. Field measurement and data analysis of compressive wave (p-wave, vp was performed using seismic refraction survey (ABEM Terraloc MK 8, 7 kg of sledgehammer and 24 units of vertical geophone and OPTIM (SeisOpt@Picker & SeisOpt@2D software respectively. Then, 3-D compressive wave distribution of subsurface studied was obtained using analysis of SURFER software. Based on 3-D compressive wave image analyzed, it was found that subsurface profile studied consist of three main layers representing top soil (vp = 376 – 600 m/s, weathered material (vp = 900 – 2600 m/s and bedrock (vp > 3000 m/s. Thickness of each layer was varied from 0 – 2 m (first layer, 2 – 20 m (second layer and 20 m and over (third layer. Moreover, groundwater (vp = 1400 – 1600 m/s starts to be detected at 2.0 m depth from ground surface. This study has demonstrated that geotechnical site investigation data related to subsurface profiling was applicable to be obtained using 3-D compressive wave imaging. Furthermore, 3-D compressive wave imaging was performed based on non destructive principle in ground exploration thus consider economic, less time, large data coverage and sustainable to our environment.

Quantum baker maps with controlled-not coupling

International Nuclear Information System (INIS)

Vallejos, Raul O; Santoro, Pedro R del; Almeida, Alfredo M Ozorio de

2006-01-01

The characteristic stretching and squeezing of chaotic motion is linearized within the finite number of phase space domains which subdivide a classical baker map. Tensor products of such maps are also chaotic, but a more interesting generalized baker map arises if the stacking orders for the factor maps are allowed to interact. These maps are readily quantized, in such a way that the stacking interaction is entirely attributed to primary qubits in each map, if each jth subsystem has Hilbert space dimension D j 2 n j . We here study the particular example of two baker maps that interact via a controlled-not interaction, which is a universal gate for quantum computation. Numerical evidence indicates that the control subspace becomes an ideal Markovian environment for the target map in the limit of large Hilbert space dimension

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

Airborne gamma-ray spectrometer and magnetometer survey: New Rockford quadrangle, North Dakota. Final report

International Nuclear Information System (INIS)

1981-04-01

Volume II contains the flight path, radiometric multi-parameter stacked profiles, magnetic and ancillary parameter stacked profiles, histograms, and anomaly maps for the New Rockford Quadrangle in North Dakota

Corroboration of Raman and AFM mapping to study Si nanocrystals embedded in SiO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Rani, Ekta, E-mail: ades.ekta@gmail.com [Laser Physics Applications Section, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India); Homi Bhabha National Institute, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India); Ingale, Alka A. [Laser Physics Applications Section, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India); Homi Bhabha National Institute, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India); Chaturvedi, A. [Laser Material Processing Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India); Joshi, M.P.; Kukreja, L.M. [Homi Bhabha National Institute, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India); Laser Material Processing Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India)

2016-07-05

Raman and atomic force microscopy (AFM) mapping on the same selected area are used to get unique information about the morphology of Si nanocrystals (NCs) embedded in SiO{sub 2}, which is difficult to obtain by any other conventional technique. The sensitivity of Raman spectroscopy to surface/interface and confinement effects in NCs is effectively used to correlate the Raman intensity profile in Raman mapping with the topography obtained from AFM to understand that Si NCs are clustered in i) smaller clusters (∼100 nm) organized closely in two dimensions (2D) and ii) big (∼2 μm) three dimensional (3D) isolated clusters, although the growth is carried out to be multilayer (Si/SiO{sub 2}). Raman mapping performed by varying the focal spot along the depth shows stacking of larger (>∼60 Å) to smaller sizes (<∼40 Å) Si NCs from bottom to top for some clusters. To understand the observed morphologies, further study of specially grown Si–SiO{sub 2} nanocomposites is performed, which suggest formation of smaller Si NCs at the top due to annealing at 800 °C in Si rich SiO{sub 2} and possible existence of thermal gradient in an insulating matrix of SiO{sub 2.} Larger Si NCs are formed in the laser induced plume (plasma) itself. - Graphical abstract: a) Schematic showing the expected stacking of Si NCs obtained from Raman mapping, performed by changing focal spot along the depth, b) top, c) middle and d) bottom region of the cluster. - Highlights: • Methodology is developed to obtain Raman and AFM mapping at same selected area. • To get unique information, difficult to obtain using other conventional techniques. • Clusters (∼100 nm–2 μm) of Si nanocrystals embedded in SiO{sub 2} matrix are formed. • Stacking of Si nanocrystals from bottom to top (10–1 nm) is observed in some clusters. • Stacking of Si nanocrystals is understood as due to annealing and thermal gradient.

Crustal structure of the Churchill-Superior boundary zone between 80 and 98 deg W longitude from Magsat anomaly maps and stacked passes

Science.gov (United States)

Hall, D. H.; Millar, T. W.; Noble, I. A.

1985-01-01

A modeling technique using spherical shell elements and equivalent dipole sources has been applied to Magsat signatures at the Churchill-Superior boundary in Manitoba, Ontario, and Ungava. A large satellite magnetic anomaly (12 nT amplitude) on POGO and Magsat maps near the Churchill-Superior boundary was found to be related to the Richmond Gulf aulacogen. The averaged crustal magnetization in the source region is 5.2 A/m. Stacking of the magnetic traces from Magsat passes reveals a magnetic signature (10 nT amplitude) at the Churchill-Superior boundary in an area studied between 80 deg W and 98 deg W. Modeling suggests a steplike thickening of the crust on the Churchill side of the boundary in a layer with a magnetization of 5 A/m. Signatures on aeromagnetic maps are also found in the source areas for both of these satellite anomalies.

Mapping afforestation and its carbon stock using time-series Landsat stacks

Science.gov (United States)

Liu, L.; Wu, Y.

2015-12-01

The Three Norths Shelter Forest Programme (TNSFP) is the largest afforestation reconstruction project in the world. Remote sensing is a crucial tool to map land cover and cover changes, but it is still challenging to accurately quantify the plantation and its carbon stock from time-series satellite images. In this paper, the Yulin district, Shaanxi province, representing a typical afforestation area in the TNSFP region, was selected as the study area, and there were twenty-nine Landsat MSS/TM/ETM+ epochs were collected from 1974 to 2012 to reconstruct the forest changes and carbon stock in last 40 years. Firstly, the Landsat ground surface reflectance (GSR) images from 1974 to 2013 were collected and processed based on 6S atmospheric transfer code and a relative reflectance normalization algorithm. Subsequently, we developed a vegetation change tracking method to reconstruct the forest change history (afforestation and deforestation) from the dense time-series Landsat GSR images based on the integrated forest z-score (IFZ) model, and the afforestation age was successfully retrieved from the Landsat time-series stacks in the last forty years and shown to be consistent with the surveyed tree ages, with a RMSE value of 4.32 years and a determination coefficient (R²) of 0.824. Then, the AGB regression models were successfully developed by integrating vegetation indices and tree age. The simple ratio vegetation index (SR) is the best candidate of the commonly used vegetation indices for estimating forest AGB, and the forest AGB model was significantly improved using the combination of SR and tree age, with R² values from 0.50 to 0.727. Finally, the forest AGB images were mapped at eight epochs from 1985 to 2013 using SR and afforestation age. The total forest AGB in six counties of Yulin District increased by 20.8 G kg, from 5.8 G kg in 1986 to 26.6 G kg in 2013, a total increase of 360%. For the forest area since 1974, the forest AGB density increased from 15.72 t

LC-MS/MS Peptide Mapping with Automated Data Processing for Routine Profiling of N-Glycans in Immunoglobulins

Science.gov (United States)

Shah, Bhavana; Jiang, Xinzhao Grace; Chen, Louise; Zhang, Zhongqi

2014-06-01

Protein N-Glycan analysis is traditionally performed by high pH anion exchange chromatography (HPAEC), reversed phase liquid chromatography (RPLC), or hydrophilic interaction liquid chromatography (HILIC) on fluorescence-labeled glycans enzymatically released from the glycoprotein. These methods require time-consuming sample preparations and do not provide site-specific glycosylation information. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) peptide mapping is frequently used for protein structural characterization and, as a bonus, can potentially provide glycan profile on each individual glycosylation site. In this work, a recently developed glycopeptide fragmentation model was used for automated identification, based on their MS/MS, of N-glycopeptides from proteolytic digestion of monoclonal antibodies (mAbs). Experimental conditions were optimized to achieve accurate profiling of glycoforms. Glycan profiles obtained from LC-MS/MS peptide mapping were compared with those obtained from HPAEC, RPLC, and HILIC analyses of released glycans for several mAb molecules. Accuracy, reproducibility, and linearity of the LC-MS/MS peptide mapping method for glycan profiling were evaluated. The LC-MS/MS peptide mapping method with fully automated data analysis requires less sample preparation, provides site-specific information, and may serve as an alternative method for routine profiling of N-glycans on immunoglobulins as well as other glycoproteins with simple N-glycans.

Accelerated testing of solid oxide fuel cell stacks for micro combined heat and power application

DEFF Research Database (Denmark)

Hagen, Anke; Høgh, Jens Valdemar Thorvald; Barfod, Rasmus

2015-01-01

State-of-the-art (SoA) solid oxide fuel cell (SOFC) stacks are tested using profiles relevant for use in micro combined heat and power (CHP) units. Such applications are characterised by dynamic load profiles. In order to shorten the needed testing time and to investigate potential acceleration...... of degradation, the profiles are executed faster than required for real applications. Operation with fast load cycling, both using hydrogen and methane/steam as fuels, does not accelerate degradation compared to constant operation, which demonstrates the maturity of SoA stacks and enables transferring knowledge...... effect for long life-times than regular short time changes of operation. In order to address lifetime testing it is suggested to build a testing program consisting of defined modules that represent different application profiles, such as one module at constant conditions, followed by modules at one set...

A Force Sensorless Method for CFRP/Ti Stack Interface Detection during Robotic Orbital Drilling Operations

Directory of Open Access Journals (Sweden)

Qiang Fang

2015-01-01

Full Text Available Drilling carbon fiber reinforced plastics and titanium (CFRP/Ti stacks is one of the most important activities in aircraft assembly. It is favorable to use different drilling parameters for each layer due to their dissimilar machining properties. However, large aircraft parts with changing profiles lead to variation of thickness along the profiles, which makes it challenging to adapt the cutting parameters for different materials being drilled. This paper proposes a force sensorless method based on cutting force observer for monitoring the thrust force and identifying the drilling material during the drilling process. The cutting force observer, which is the combination of an adaptive disturbance observer and friction force model, is used to estimate the thrust force. An in-process algorithm is developed to monitor the variation of the thrust force for detecting the stack interface between the CFRP and titanium materials. Robotic orbital drilling experiments have been conducted on CFRP/Ti stacks. The estimate error of the cutting force observer was less than 13%, and the stack interface was detected in 0.25 s (or 0.05 mm before or after the tool transited it. The results show that the proposed method can successfully detect the CFRP/Ti stack interface for the cutting parameters adaptation.

Preparation and characterization of porphyrin-polythiophene stacked films as prepared by electrochemical method under stirring condition

International Nuclear Information System (INIS)

Sugawa, Kosuke; Akiyama, Tsuyoshi; Yamada, Sunao

2008-01-01

Porphyrin-polythiophene (pTh) stacked films consisting of meso-tetrathienylporphyrin (TThP) and bithiophene (BiTh) were prepared on transparent indium-tin-oxide (ITO) electrodes by sequential electrochemical scanning of applied potential between 0 and + 2 V vs Ag wire in the electrolyte solution of BiTh and TThP under stirring condition. First, the pTh films were prepared by electrochemical polymerization and then TThP was incorporated into the as-prepared pTh film by subsequent electrochemical scanning as described above in the TThP solution. The operation of solution stirring during electrochemical scanning achieved the formation of robust stacked films. UV/Vis and fluorescence spectra confirmed that the amount of TThP moiety increased with increasing the number of electrochemical scanning cycles in the TThP solution. In order to evaluate the incorporation profile of TThP, surface analyses and depth profiles of stacked films were carried out by XPS spectroscopy. The results suggested that all films formed porphyrin-polythiophene stacked structure precisely, and that TThP was exclusively incorporated around the outermost region of the pTh film

Publishing Platform for Aerial Orthophoto Maps, the Complete Stack

Science.gov (United States)

Čepický, J.; Čapek, L.

2016-06-01

When creating set of orthophoto maps from mosaic compositions, using airborne systems, such as popular drones, we need to publish results of the work to users. Several steps need to be performed in order get large scale raster data published. As first step, data have to be shared as service (OGC WMS as view service, OGC WCS as download service). But for some applications, OGC WMTS is handy as well, for faster view of the data. Finally the data have to become a part of web mapping application, so that they can be used and evaluated by non-technical users. In this talk, we would like to present automated line of those steps, where user puts in orthophoto image and as a result, OGC Open Web Services are published as well as web mapping application with the data. The web mapping application can be used as standard presentation platform for such type of big raster data to generic user. The publishing platform - Geosense online map information system - can be also used for combination of data from various resources and for creating of unique map compositions and as input for better interpretations of photographed phenomenons. The whole process is successfully tested with eBee drone with raster data resolution 1.5-4 cm/px on many areas and result is also used for creation of derived datasets, usually suited for property management - the records of roads, pavements, traffic signs, public lighting, sewage system, grave locations, and others.

Universal composition-structure-property maps for natural and biomimetic platelet-matrix composites and stacked heterostructures.

Science.gov (United States)

Sakhavand, Navid; Shahsavari, Rouzbeh

2015-03-16

Many natural and biomimetic platelet-matrix composites--such as nacre, silk, and clay-polymer-exhibit a remarkable balance of strength, toughness and/or stiffness, which call for a universal measure to quantify this outstanding feature given the structure and material characteristics of the constituents. Analogously, there is an urgent need to quantify the mechanics of emerging electronic and photonic systems such as stacked heterostructures. Here we report the development of a unified framework to construct universal composition-structure-property diagrams that decode the interplay between various geometries and inherent material features in both platelet-matrix composites and stacked heterostructures. We study the effects of elastic and elastic-perfectly plastic matrices, overlap offset ratio and the competing mechanisms of platelet versus matrix failures. Validated by several 3D-printed specimens and a wide range of natural and synthetic materials across scales, the proposed universally valid diagrams have important implications for science-based engineering of numerous platelet-matrix composites and stacked heterostructures.

Backside versus frontside advanced chemical analysis of high-k/metal gate stacks

Energy Technology Data Exchange (ETDEWEB)

Martinez, E., E-mail: eugenie.martinez@cea.fr [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Saidi, B. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Veillerot, M. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Caubet, P. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Fabbri, J-M. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Piallat, F. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Gassilloud, R. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Schamm-Chardon, S. [CEMES-CNRS et Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse (France)

2015-08-15

Highlights: • The backside approach is a promising solution for advanced chemical characterization of future MOSFETs. • Frontside ToF-SIMS and Auger depth profiles are affected by cumulative mixing effects and thus not relevant for analyzing ultra-thin layers. • Higher in-depth resolution is possible in the backside approach for Auger and ToF-SIMS depth profiling. • Backside depth profiling allows revealing ultra-thin layers and elemental in-depth redistribution inside high-k/metal gate stacks. • Backside XPS allows preserving the full metal gate, thus enabling the analysis of real technological samples. - Abstract: Downscaling of transistors beyond the 14 nm technological node requires the implementation of new architectures and materials. Advanced characterization methods are needed to gain information about the chemical composition of buried layers and interfaces. An effective approach based on backside analysis is presented here. X-ray photoelectron spectroscopy, Auger depth profiling and time-of-flight secondary ions mass spectrometry are combined to investigate inter-diffusion phenomena. To highlight improvements related to the backside method, backside and frontside analyses are compared. Critical information regarding nitrogen, oxygen and aluminium redistribution inside the gate stacks is obtained only in the backside configuration.

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.

Algebraic stacks

Indian Academy of Sciences (India)

Deligne, Mumford and Artin [DM, Ar2]) and consider algebraic stacks, then we can cons- truct the 'moduli ... the moduli scheme and the moduli stack of vector bundles. First I will give ... 1–31. © Printed in India. 1 ...... Cultura, Spain. References.

Visualizing flow fields using acoustic Doppler current profilers and the Velocity Mapping Toolbox

Science.gov (United States)

Jackson, P. Ryan

2013-01-01

The purpose of this fact sheet is to provide examples of how the U.S. Geological Survey is using acoustic Doppler current profilers for much more than routine discharge measurements. These instruments are capable of mapping complex three-dimensional flow fields within rivers, lakes, and estuaries. Using the Velocity Mapping Toolbox to process the ADCP data allows detailed visualization of the data, providing valuable information for a range of studies and applications.

StackGAN++: Realistic Image Synthesis with Stacked Generative Adversarial Networks

OpenAIRE

Zhang, Han; Xu, Tao; Li, Hongsheng; Zhang, Shaoting; Wang, Xiaogang; Huang, Xiaolei; Metaxas, Dimitris

2017-01-01

Although Generative Adversarial Networks (GANs) have shown remarkable success in various tasks, they still face challenges in generating high quality images. In this paper, we propose Stacked Generative Adversarial Networks (StackGAN) aiming at generating high-resolution photo-realistic images. First, we propose a two-stage generative adversarial network architecture, StackGAN-v1, for text-to-image synthesis. The Stage-I GAN sketches the primitive shape and colors of the object based on given...

Fault Creep along the Southern San Andreas from Interferometric Synthetic Aperture Radar, Permanent Scatterers, and Stacking

Science.gov (United States)

Lyons, Suzanne; Sandwell, David

2003-01-01

Interferometric synthetic aperture radar (InSAR) provides a practical means of mapping creep along major strike-slip faults. The small amplitude of the creep signal (less than 10 mm/yr), combined with its short wavelength, makes it difficult to extract from long time span interferograms, especially in agricultural or heavily vegetated areas. We utilize two approaches to extract the fault creep signal from 37 ERS SAR images along the southem San Andreas Fault. First, amplitude stacking is utilized to identify permanent scatterers, which are then used to weight the interferogram prior to spatial filtering. This weighting improves correlation and also provides a mask for poorly correlated areas. Second, the unwrapped phase is stacked to reduce tropospheric and other short-wavelength noise. This combined processing enables us to recover the near-field (approximately 200 m) slip signal across the fault due to shallow creep. Displacement maps fiom 60 interferograms reveal a diffuse secular strain buildup, punctuated by localized interseismic creep of 4-6 mm/yr line of sight (LOS, 12-18 mm/yr horizontal). With the exception of Durmid Hill, this entire segment of the southern San Andreas experienced right-lateral triggered slip of up to 10 cm during the 3.5-year period spanning the 1992 Landers earthquake. The deformation change following the 1999 Hector Mine earthquake was much smaller (4 cm) and broader than for the Landers event. Profiles across the fault during the interseismic phase show peak-to-trough amplitude ranging from 15 to 25 mm/yr (horizontal component) and the minimum misfit models show a range of creeping/locking depth values that fit the data.

SHARAKU: an algorithm for aligning and clustering read mapping profiles of deep sequencing in non-coding RNA processing.

Science.gov (United States)

Tsuchiya, Mariko; Amano, Kojiro; Abe, Masaya; Seki, Misato; Hase, Sumitaka; Sato, Kengo; Sakakibara, Yasubumi

2016-06-15

Deep sequencing of the transcripts of regulatory non-coding RNA generates footprints of post-transcriptional processes. After obtaining sequence reads, the short reads are mapped to a reference genome, and specific mapping patterns can be detected called read mapping profiles, which are distinct from random non-functional degradation patterns. These patterns reflect the maturation processes that lead to the production of shorter RNA sequences. Recent next-generation sequencing studies have revealed not only the typical maturation process of miRNAs but also the various processing mechanisms of small RNAs derived from tRNAs and snoRNAs. We developed an algorithm termed SHARAKU to align two read mapping profiles of next-generation sequencing outputs for non-coding RNAs. In contrast with previous work, SHARAKU incorporates the primary and secondary sequence structures into an alignment of read mapping profiles to allow for the detection of common processing patterns. Using a benchmark simulated dataset, SHARAKU exhibited superior performance to previous methods for correctly clustering the read mapping profiles with respect to 5'-end processing and 3'-end processing from degradation patterns and in detecting similar processing patterns in deriving the shorter RNAs. Further, using experimental data of small RNA sequencing for the common marmoset brain, SHARAKU succeeded in identifying the significant clusters of read mapping profiles for similar processing patterns of small derived RNA families expressed in the brain. The source code of our program SHARAKU is available at http://www.dna.bio.keio.ac.jp/sharaku/, and the simulated dataset used in this work is available at the same link. Accession code: The sequence data from the whole RNA transcripts in the hippocampus of the left brain used in this work is available from the DNA DataBank of Japan (DDBJ) Sequence Read Archive (DRA) under the accession number DRA004502. yasu@bio.keio.ac.jp Supplementary data are available

NOAA JPSS Ozone Mapping and Profiler Suite (OMPS) Nadir Total Column Sensor Data Record (SDR) from IDPS

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Ozone Mapping and Profiler Suite (OMPS) onboard the Suomi NPP satellite monitors ozone from space. OMPS will collect total column and vertical profile ozone data...

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.

Global mapping of vertical injection profiles of wild-fire emission

Science.gov (United States)

Sofiev, M.; Vankevich, R.; Ermakova, T.; Hakkarainen, J.

2012-08-01

A problem of a characteristic vertical profile of smoke released from wild-land fires is considered. A methodology for bottom-up evaluation of this profile is suggested and a corresponding global dataset is calculated. The profile estimation is based on: (i) a semi-empirical formula for plume-top height recently suggested by the authors, (ii) MODIS satellite observations of active wild-land fires, and (iii) meteorological conditions evaluated at each fireplace using output of ECMWF weather prediction model. Plumes from all fires recorded globally during two arbitrarily picked years 2001 and 2008 are evaluated and their smoke injection profiles are estimated with a time step of 3 h. The resulting 4-dimensional dataset is split to day- and night-time subsets. Each of the subsets is projected to global grid with resolution 1° × 1° × 500 m, averaged to monthly level, and normalised with total emission. Evaluation of the obtained dataset was performed at several levels. Firstly, the quality of the semi-empirical formula for plume-top computations was evaluated using recent additions to the MISR fire plume-height dataset. Secondly, the obtained maps of injection profiles are compared with another global distribution available from literature. Thirdly, the upper percentiles of the profiles are compared with an independent dataset of space-based lidar CALIOP. Finally, the stability of the calculated profiles with regard to inter-annual variations of the fire activity and meteorological conditions is roughly estimated by comparing the sub-sets for 2001 and 2008.

Development and characterization of a three-dimensional radiochromic film stack dosimeter for megavoltage photon beam dosimetry.

Science.gov (United States)

McCaw, Travis J; Micka, John A; DeWerd, Larry A

2014-05-01

Three-dimensional (3D) dosimeters are particularly useful for verifying the commissioning of treatment planning and delivery systems, especially with the ever-increasing implementation of complex and conformal radiotherapy techniques such as volumetric modulated arc therapy. However, currently available 3D dosimeters require extensive experience to prepare and analyze, and are subject to large measurement uncertainties. This work aims to provide a more readily implementable 3D dosimeter with the development and characterization of a radiochromic film stack dosimeter for megavoltage photon beam dosimetry. A film stack dosimeter was developed using Gafchromic(®) EBT2 films. The dosimeter consists of 22 films separated by 1 mm-thick spacers. A Virtual Water™ phantom was created that maintains the radial film alignment within a maximum uncertainty of 0.3 mm. The film stack dosimeter was characterized using simulations and measurements of 6 MV fields. The absorbed-dose energy dependence and orientation dependence of the film stack dosimeter were investigated using Monte Carlo simulations. The water equivalence of the dosimeter was determined by comparing percentage-depth-dose (PDD) profiles measured with the film stack dosimeter and simulated using Monte Carlo methods. Film stack dosimeter measurements were verified with thermoluminescent dosimeter (TLD) microcube measurements. The film stack dosimeter was also used to verify the delivery of an intensity-modulated radiation therapy (IMRT) procedure. The absorbed-dose energy response of EBT2 film differs less than 1.5% between the calibration and film stack dosimeter geometries for a 6 MV spectrum. Over a series of beam angles ranging from normal incidence to parallel incidence, the overall variation in the response of the film stack dosimeter is within a range of 2.5%. Relative to the response to a normally incident beam, the film stack dosimeter exhibits a 1% under-response when the beam axis is parallel to the film

Seafloor Age-Stacking Reveals No Evidence for Milankovitch Cycle Influence on Abyssal Hills at Intermediate, Fast and Super-Fast Spreading Rates

Science.gov (United States)

Goff, J.; Zahirovic, S.; Müller, D.

2017-12-01

Recently published spectral analyses of seafloor bathymetry concluded that abyssal hills, highly linear ridges that are formed along seafloor spreading centers, exhibit periodicities that correspond to Milankovitch cycles - variations in Earth's orbit that affect climate on periods of 23, 41 and 100 thousand years. These studies argue that this correspondence could be explained by modulation of volcanic output at the mid-ocean ridge due to lithostatic pressure variations associated with rising and falling sea level. If true, then the implications are substantial: mapping the topography of the seafloor with sonar could be used as a way to investigate past climate change. This "Milankovitch cycle" hypothesis predicts that the rise and fall of abyssal hills will be correlated to crustal age, which can be tested by stacking, or averaging, bathymetry as a function of age; stacking will enhance any age-dependent signal while suppressing random components, such as fault-generated topography. We apply age-stacking to data flanking the Southeast Indian Ridge ( 3.6 cm/yr half rate), northern East Pacific Rise ( 5.4 cm/yr half rate) and southern East Pacific Rise ( 7.8 cm/yr half rate), where multibeam bathymetric coverage is extensive on the ridge flanks. At the greatest precision possible given magnetic anomaly data coverage, we have revised digital crustal age models in these regions with updated axis and magnetic anomaly traces. We also utilize known 2nd-order spatial statistical properties of abyssal hills to predict the variability of the age-stack under the null hypothesis that abyssal hills are entirely random with respect to crustal age; the age-stacked profile is significantly different from zero only if it exceeds this expected variability by a large margin. Our results indicate, however, that the null hypothesis satisfactorily explains the age-stacking results in all three regions of study, thus providing no support for the Milankovitch cycle hypothesis. The

Stacking stability of MoS2 bilayer: An ab initio study

International Nuclear Information System (INIS)

Tao Peng; Guo Huai-Hong; Yang Teng; Zhang Zhi-Dong

2014-01-01

The study of the stacking stability of bilayer MoS 2 is essential since a bilayer has exhibited advantages over single layer MoS 2 in many aspects for nanoelectronic applications. We explored the relative stability, optimal sliding path between different stacking orders of bilayer MoS 2 , and (especially) the effect of inter-layer stress, by combining first-principles density functional total energy calculations and the climbing-image nudge-elastic-band (CI-NEB) method. Among five typical stacking orders, which can be categorized into two kinds (I: AA, AB and II: AA', AB', A'B), we found that stacking orders with Mo and S superposing from both layers, such as AA' and AB, is more stable than the others. With smaller computational efforts than potential energy profile searching, we can study the effect of inter-layer stress on the stacking stability. Under isobaric condition, the sliding barrier increases by a few eV/(ucGPa) from AA' to AB', compared to 0.1 eV/(ucGPa) from AB to [AB]. Moreover, we found that interlayer compressive stress can help enhance the transport properties of AA'. This study can help understand why inter-layer stress by dielectric gating materials can be an effective means to improving MoS 2 on nanoelectronic applications. (condensed matter: structural, mechanical, and thermal properties)

Study of airborne gamma-ray spectrometer data procedures: Wind River Basin, Wyoming, Thermopolis Quadrangle

International Nuclear Information System (INIS)

1979-01-01

This volume contains the following data from the Thermopolis Quadrangle, Wind River Basin, Wyoming: statistical summary tables; flight-line averages; geologic map units; geologic map with record locations; uranium mines and occurrences, uranium location map; eU symbol anomaly map; eU/eTh symbol anomaly map; eU/K symbol anomaly map; eTh symbol anomaly map; K symbol anomaly map; eU profile anomaly map; eU/eTh profile anomaly map; eU/K profile anomaly map; eTh profile anomaly map; K profile anomaly map; eTh/K profile anomaly map; preferred anomaly maps (4- and 7-point), combined 4- and 7-point preferred anomaly map; and stacked significance factor profiles

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.

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.

High power multiple wavelength diode laser stack for DPSSL application without temperature control

Science.gov (United States)

Hou, Dong; Yin, Xia; Wang, Jingwei; Chen, Shi; Zhan, Yun; Li, Xiaoning; Fan, Yingmin; Liu, Xingsheng

2018-02-01

High power diode laser stack is widely used in pumping solid-state laser for years. Normally an integrated temperature control module is required for stabilizing the output power of solid-state laser, as the output power of the solid-state laser highly depends on the emission wavelength and the wavelength shift of diode lasers according to the temperature changes. However the temperature control module is inconvenient for this application, due to its large dimension, high electric power consumption and extra adding a complicated controlling system. Furthermore, it takes dozens of seconds to stabilize the output power when the laser system is turned on. In this work, a compact hard soldered high power conduction cooled diode laser stack with multiple wavelengths is developed for stabilizing the output power of solid-state laser in a certain temperature range. The stack consists of 5 laser bars with the pitch of 0.43mm. The peak output power of each bar in the diode laser stack reaches as much as 557W and the combined lasing wavelength spectrum profile spans 15nm. The solidstate laser, structured with multiple wavelength diode laser stacks, allows the ambient temperature change of 65°C without suddenly degrading the optical performance.

Radio-frequency properties of stacked long Josephson junctions with nonuniform bias current distribution

DEFF Research Database (Denmark)

Filatrella, G; Pedersen, Niels Falsig

1999-01-01

We have numerically investigated the behavior of stacks of long Josephson junctions considering a nonuniform bias profile. In the presence of a microwave field the nonuniform bias, which favors the formation of fluxons, can give rise to a change of the sequence of radio-frequency induced steps...

Modeling fuel cell stack systems

Energy Technology Data Exchange (ETDEWEB)

Lee, J H [Los Alamos National Lab., Los Alamos, NM (United States); Lalk, T R [Dept. of Mech. Eng., Texas A and M Univ., College Station, TX (United States)

1998-06-15

A technique for modeling fuel cell stacks is presented along with the results from an investigation designed to test the validity of the technique. The technique was specifically designed so that models developed using it can be used to determine the fundamental thermal-physical behavior of a fuel cell stack for any operating and design configuration. Such models would be useful tools for investigating fuel cell power system parameters. The modeling technique can be applied to any type of fuel cell stack for which performance data is available for a laboratory scale single cell. Use of the technique is demonstrated by generating sample results for a model of a Proton Exchange Membrane Fuel Cell (PEMFC) stack consisting of 125 cells each with an active area of 150 cm{sup 2}. A PEMFC stack was also used in the verification investigation. This stack consisted of four cells, each with an active area of 50 cm{sup 2}. Results from the verification investigation indicate that models developed using the technique are capable of accurately predicting fuel cell stack performance. (orig.)

Application of damping mechanism model and stacking fault probability in Fe-Mn alloy

International Nuclear Information System (INIS)

Huang, S.K.; Wen, Y.H.; Li, N.; Teng, J.; Ding, S.; Xu, Y.G.

2008-01-01

In this paper, the damping mechanism model of Fe-Mn alloy was analyzed using dislocation theory. Moreover, as an important parameter in Fe-Mn based alloy, the effect of stacking fault probability on the damping capacity of Fe-19.35Mn alloy after deep-cooling or tensile deformation was also studied. The damping capacity was measured using reversal torsion pendulum. The stacking fault probability of γ-austenite and ε-martensite was determined by means of X-ray diffraction (XRD) profile analysis. The microstructure was observed using scanning electronic microscope (SEM). The results indicated that with the strain amplitude increasing above a critical value, the damping capacity of Fe-19.35Mn alloy increased rapidly which could be explained using the breakaway model of Shockley partial dislocations. Deep-cooling and suitable tensile deformation could improve the damping capacity owning to the increasing of stacking fault probability of Fe-19.35Mn alloy

Stacking gels: A method for maximising output for pulsed-field gel electrophoresis

Directory of Open Access Journals (Sweden)

Heng See

2009-01-01

Full Text Available Pulsed field gel electrophoresis (PFGE, the gold standard of molecular typing methods, has a major disadvantage of an unusually long electrophoretic time. From the original protocol of 6 days, it was modified to 3 days and subsequently to a single day. We describe the procedure of stacking five to six gels one on top of another in order to increase and maximize the output in a shorter time without compromising the resolution and reproducibility. All the variables that affect pulsed field gels during electrophoresis were taken into consideration. We firstly optimized the parameters to be used and secondly determined whether stacking of five to six gels had any effect on the molecular separation during electrophoresis in comparison with a single gel run. DNA preparation, restriction, electrophoresis, staining and gel documentation was carried out based on previously published methods. Gels were analysed using BioNumerics and dice coefficient and unweighted pair group methods were used to generate dendrograms based on 1.5% tolerance values. Identical band profiles and band resolution-separation were seen in the PFGE patterns with single gel and multiple stacking gels. Cluster analysis further strengthened the fact that results from stacking gels were reproducible and comparable with a single gel run. This method of stacking gels saves time and maximizes the output at the same time. The run time for a single gel was about 28 hours, but with six stacked gels the run time was 54 hours compared with 28 x 6 = 168 hours if they were run separately as single gels thus saving time of 67.86%. Beside the big factor of saving time, stacking gels save resources (electricity, reagents, water, chemicals and working time by increasing the sample throughput in a shorter time without compromising on quality of data. But optimization of working parameters is vital depending on the PFGE system used.

Reciprocal space mapping by spot profile analyzing low energy electron diffraction

International Nuclear Information System (INIS)

Meyer zu Heringdorf, Frank-J.; Horn-von Hoegen, Michael

2005-01-01

We present an experimental approach for the recording of two-dimensional reciprocal space maps using spot profile analyzing low energy electron diffraction (SPA-LEED). A specialized alignment procedure eliminates the shifting of LEED patterns on the screen which is commonly observed upon variation of the electron energy. After the alignment, a set of one-dimensional sections through the diffraction pattern is recorded at different energies. A freely available software tool is used to assemble the sections into a reciprocal space map. The necessary modifications of the Burr-Brown computer interface of the two Leybold and Omicron type SPA-LEED instruments are discussed and step-by-step instructions are given to adapt the SPA 4.1d software to the changed hardware. Au induced faceting of 4 deg. vicinal Si(001) is used as an example to demonstrate the technique

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)

Environmental assessment of phosphogypsum stacks

International Nuclear Information System (INIS)

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

2009-01-01

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)

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.

Solid Oxide Fuel Cell Stack Diagnostics

DEFF Research Database (Denmark)

Mosbæk, Rasmus Rode; Barfod, Rasmus Gottrup

As SOFC technology is moving closer to a commercial break through, methods to measure the “state-of-health” of operating stacks are becoming of increasing interest. This requires application of advanced methods for detailed electrical and electrochemical characterization during operation....... 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...... 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...

Development and Characterization of an Electrically Rechargeable Zinc-Air Battery Stack

Directory of Open Access Journals (Sweden)

Hongyun Ma

2014-10-01

Full Text Available An electrically rechargeable zinc-air battery stack consisting of three single cells in series was designed using a novel structured bipolar plate with air-breathing holes. Alpha-MnO2 and LaNiO3 severed as the catalysts for the oxygen reduction reaction (ORR and oxygen evolution reaction (OER. The anodic and cathodic polarization and individual cell voltages were measured at constant charge-discharge (C-D current densities indicating a uniform voltage profile for each single cell. One hundred C-D cycles were carried out for the stack. The results showed that, over the initial 10 cycles, the average C-D voltage gap was about 0.94 V and the average energy efficiency reached 89.28% with current density charging at 15 mA·cm−2 and discharging at 25 mA·cm−2. The total increase in charging voltage over the 100 C-D cycles was ~1.56% demonstrating excellent stability performance. The stack performance degradation was analyzed by galvanostatic electrochemical impedance spectroscopy. The charge transfer resistance of ORR increased from 1.57 to 2.21 Ω and that of Zn/Zn2+ reaction increased from 0.21 to 0.34 Ω after 100 C-D cycles. The quantitative analysis guided the potential for the optimization of both positive and negative electrodes to improve the cycle life of the cell stack.

ooi: OpenStack OCCI interface

Directory of Open Access Journals (Sweden)

Álvaro López García

2016-01-01

Full Text Available In this document we present an implementation of the Open Grid Forum’s Open Cloud Computing Interface (OCCI for OpenStack, namely ooi (Openstack occi interface, 2015  [1]. OCCI is an open standard for management tasks over cloud resources, focused on interoperability, portability and integration. ooi aims to implement this open interface for the OpenStack cloud middleware, promoting interoperability with other OCCI-enabled cloud management frameworks and infrastructures. ooi focuses on being non-invasive with a vanilla OpenStack installation, not tied to a particular OpenStack release version.

ooi: OpenStack OCCI interface

Science.gov (United States)

López García, Álvaro; Fernández del Castillo, Enol; Orviz Fernández, Pablo

In this document we present an implementation of the Open Grid Forum's Open Cloud Computing Interface (OCCI) for OpenStack, namely ooi (Openstack occi interface, 2015) [1]. OCCI is an open standard for management tasks over cloud resources, focused on interoperability, portability and integration. ooi aims to implement this open interface for the OpenStack cloud middleware, promoting interoperability with other OCCI-enabled cloud management frameworks and infrastructures. ooi focuses on being non-invasive with a vanilla OpenStack installation, not tied to a particular OpenStack release version.

geomorphological mapping and geophysical profiling for the evaluation of natural hazards in an alpine catchment

NARCIS (Netherlands)

Seijmonsbergen, A.C.; de Graaff, L.W.S.

2006-01-01

Liechtenstein has faced an increasing number of natural hazards over recent decades: debris flows, slides, snow avalanches and floods repeatedly endanger the local infrastructure. Geomorphological field mapping and geo-electrical profiling was used to assess hazards near Malbun, a village

The SBOL Stack: A Platform for Storing, Publishing, and Sharing Synthetic Biology Designs.

Science.gov (United States)

Madsen, Curtis; McLaughlin, James Alastair; Mısırlı, Göksel; Pocock, Matthew; Flanagan, Keith; Hallinan, Jennifer; Wipat, Anil

2016-06-17

Recently, synthetic biologists have developed the Synthetic Biology Open Language (SBOL), a data exchange standard for descriptions of genetic parts, devices, modules, and systems. The goals of this standard are to allow scientists to exchange designs of biological parts and systems, to facilitate the storage of genetic designs in repositories, and to facilitate the description of genetic designs in publications. In order to achieve these goals, the development of an infrastructure to store, retrieve, and exchange SBOL data is necessary. To address this problem, we have developed the SBOL Stack, a Resource Description Framework (RDF) database specifically designed for the storage, integration, and publication of SBOL data. This database allows users to define a library of synthetic parts and designs as a service, to share SBOL data with collaborators, and to store designs of biological systems locally. The database also allows external data sources to be integrated by mapping them to the SBOL data model. The SBOL Stack includes two Web interfaces: the SBOL Stack API and SynBioHub. While the former is designed for developers, the latter allows users to upload new SBOL biological designs, download SBOL documents, search by keyword, and visualize SBOL data. Since the SBOL Stack is based on semantic Web technology, the inherent distributed querying functionality of RDF databases can be used to allow different SBOL stack databases to be queried simultaneously, and therefore, data can be shared between different institutes, centers, or other users.

Stack gas treatment

Science.gov (United States)

Reeves, Adam A.

1977-04-12

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

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...

Wide-Area Landslide Deformation Mapping with Multi-Path ALOS PALSAR Data Stacks: A Case Study of Three Gorges Area, China

Directory of Open Access Journals (Sweden)

Xuguo Shi

2016-02-01

Full Text Available In recent years, satellite synthetic aperture radar interferometry (InSAR has been adopted as a spaceborne geodetic tool to successfully measure surface deformation of a few well-known landslides in the Three Gorges area. In consideration of the fact that most events of slope failure happened at places other than those famous landslides since the reservoir impoundment in 2003, focusing on a limited number of slopes is insufficient to meet the requirements of regional-scale landslide disaster prevention and early warning. As a result, it has become a vital task to evaluate the overall stability of slopes across the vast area of Three Gorges using wide-coverage InSAR datasets. In this study, we explored the approach of carrying out joint analysis of multi-path InSAR data stacks for wide-area landslide deformation mapping. As an example, three ALOS (Advanced Land Observing Satellite PALSAR (Phased Array type L-band Synthetic Aperture Radar data stacks of neighboring ascending paths covering the area along the Yangtze River from Fengjie to Zigui were analyzed. A key problem to be solved is the separation of the tropospheric signal from the interferometric phase, for which we employed a hybrid description model of the atmospheric phase screen (APS to improve APS estimation from time series interferograms. The estimated atmospheric phase was largely correlated with the seasonal rainfall in the temporal dimension. The experimental results show that about 30 slopes covering total areas of 48 km2 were identified to be landslides in active deformation and should be kept under routine surveillance. Analyses of time series displacement measurements revealed that most landslides in the mountainous area far away from Yangtze River suffered from linear deformation, whereas landslides located on the river bank were destabilized predominantly by the influences of reservoir water level fluctuation and rainfall.

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.

Fast static field CIPT mapping of unpatterned MRAM film stacks

DEFF Research Database (Denmark)

Kjær, Daniel; Hansen, Ole; Henrichsen, Henrik Hartmann

2015-01-01

Current In-Plane Tunneling (CIPT) method measures both RA and TMR, but the usefulness for uniformity mapping, e.g. for tool optimization, is limited by excessive measurement time. Thus, we develop and demonstrate a fast complementary static magnetic field method focused only on measurement of RA. We...... compare the static field method to the standard CIPT method and find perfect agreement between the extracted RA values and measurement repeatability while the static field method is several times faster. The static field CIPT method is demonstrated for 200 mm wafer mapping showing radial as well...

Airborne gamma-ray spectrometer and magnetometer survey: Ely quadrangle, Nevada. Final report

International Nuclear Information System (INIS)

1980-01-01

Five uranium anomalies meet the minimum statistical requirements as defined in Volume I. These anomalies are tabulated and are shown on the Uranium Anomaly Interpretation Map, together with the interpretation of the magnetic data. This volume contains 12 appendices: flight line map; geology map; explanation of geologic legend; flight line/geology map; pseudo-contour maps; stacked profiles; anomaly maps; geologic histograms; speed and altitude histograms; statistical tables; magnetic and ancillary profile; and test line data

Helping Students Design HyperCard Stacks.

Science.gov (United States)

Dunham, Ken

1995-01-01

Discusses how to teach students to design HyperCard stacks. Highlights include introducing HyperCard, developing storyboards, introducing design concepts and scripts, presenting stacks, evaluating storyboards, and continuing projects. A sidebar presents a HyperCard stack evaluation form. (AEF)

Modular fuel-cell stack assembly

Science.gov (United States)

Patel, Pinakin

2010-07-13

A fuel cell assembly having a plurality of fuel cells arranged in a stack. An end plate assembly abuts the fuel cell at an end of said stack. The end plate assembly has an inlet area adapted to receive an exhaust gas from the stack, an outlet area and a passage connecting the inlet area and outlet area and adapted to carry the exhaust gas received at the inlet area from the inlet area to the outlet area. A further end plate assembly abuts the fuel cell at a further opposing end of the stack. The further end plate assembly has a further inlet area adapted to receive a further exhaust gas from the stack, a further outlet area and a further passage connecting the further inlet area and further outlet area and adapted to carry the further exhaust gas received at the further inlet area from the further inlet area to the further outlet area.

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

Assessing and Optimizing Argo profile mapping : An example in the Equatorial Pacific

Science.gov (United States)

Gasparin, Florent; Roemmich, Dean; Gilson, John; Sprintall, Janet

2014-05-01

Estimation of subsurface temperature, salinity and velocity has been revolutionized over the last decade as a result of development and deployment of the Argo Program. Argo products have become one of the major observational tools in Oceanography, used in a wide range of basic research, operational models, and education applications. To assess the skill of Argo in estimating oceanic conditions at different scales of variability in the Equatorial Pacific, we optimize Argo profile mapping by focusing on the covariance function. Decorrelation scales are discussed as well as impacts of several different interpolation schemes. The optimization is based on three points 1) Functional representation of the Argo sampled covariance, 2) Realism/Accuracy of the mapping errors and 3) Comparison with independent data such as TAO moorings and sea surface height. The last points show that Argo can represent more than 90% of the total TAO variance and around 80% of the intraseasonal TAO variability (between 10 and 100 days) at the Equator. As an illustration of the improvement, we show how Argo profiles can reveal the vertical structure and vertical phase propagation corresponding to the steric height annual cycle. We also discuss how this unique equatorial wave phenomena is modified during El Nino/La Nina events. This work anticipates a field experiment beginning in early 2014 and can be used for assessing and adapting the equatorial observational network.

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.

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

Determination of the stacking fault energies of face centured cubic metals and alloys by X-rays diffraction

International Nuclear Information System (INIS)

Borges, J.F.A.; Padilha, A.F.; Imakuma, K.

1988-03-01

An X-rays diffraction method was applied to measure the Stacking Fault Energies (SFE) of the AISI 304, AISI 316, AISI 347 and DIN-WERKSTOFF 1.4970 Austenitic Stainless Steels. The SFE determination plays an important role in the research of the mecanichal behaviour of the Metal and Alloys, their deformation mechanisms, stability of micro-structure and electronic configuration. The method is based on the relationship between the SFE and the ratio of the Mean Square Strains to the Stacking-Fault probability. The Mean Square Strain was evaluated by Fourier Analysis of X-rays Diffaction profiles, corrected to reduce instrumental effects, followed by the application of the Warren-Averbach method to the Fourier Coefficients. The Stacking-Fault probabilities were derived from the changes of peak separations between cold-worked and annealed specimens. (author) [pt

Pbar Beam Stacking in the Recycler by Longitudinal Phase-space Coating

Energy Technology Data Exchange (ETDEWEB)

Bhat, C. M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2013-08-06

Barrier rf buckets have brought about new challenges in longitudinal beam dynamics of charged particle beams in synchrotrons and at the same time led to many new remarkable prospects in beam handling. In this paper, I describe a novel beam stacking scheme for synchrotrons using barrier buckets without any emittance dilution to the beam. First I discuss the general principle of the method, called longitudinal phase-space coating. Multi-particle beam dynamics simulations of the scheme applied to the Recycler, convincingly validates the concepts and feasibility of the method. Then I demonstrate the technique experimentally in the Recycler and also use it in operation. A spin-off of this scheme is its usefulness in mapping the incoherent synchrotron tune spectrum of the beam particles in barrier buckets and producing a clean hollow beam in longitudinal phase space. Both of which are described here in detail with illustrations. The beam stacking scheme presented here is the first of its kind.

Depth profiling of extended defects in silicon by Rutherford backscattering measurements

International Nuclear Information System (INIS)

Gruska, B.; Goetz, G.

1981-01-01

Depth profiling of dislocations and stacking faults is carried out by analyzing axial and planar channeling data from As + -and P + -implanted silicon samples annealed at high temperatures. The analyzing procedure is based on the simple two-beam model. The results show that depth profiling of dislocations using planar channeling data is connected with a broadening of the real distributions. A degradation of the defect concentration and a deformation of the profile result for very high defect concentrations (> 5 x 10 5 cm/cm 2 ). All these effects can be neglected by analyzing axial channeling data. Depth profiling of stacking faults is restricted to the determination of the depth distribution of displaced atomic rows or planes. For both the procedures, axial as well as planar channeling measurements, the same depth profiles of displaced atomic rows are obtained. (author)

Text-Filled Stacked Area Graphs

DEFF Research Database (Denmark)

Kraus, Martin

2011-01-01

-filled stacked area graphs; i.e., graphs that feature stacked areas that are filled with small-typed text. Since these graphs allow for computing the text layout automatically, it is possible to include large amounts of textual detail with very little effort. We discuss the most important challenges and some...... solutions for the design of text-filled stacked area graphs with the help of an exemplary visualization of the genres, publication years, and titles of a database of several thousand PC games....

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

Maturing of SOFC cell and stack production technology and preparation for demonstration of SOFC stacks. Part 2

Energy Technology Data Exchange (ETDEWEB)

2006-07-01

The TOFC/Riso pilot plant production facility for the manufacture of anode-supported cells has been further up-scaled with an automated continuous spraying process and an extra sintering capacity resulting in production capacity exceeding 15,000 standard cells (12x12 cm2) in 2006 with a success rate of about 85% in the cell production. All processing steps such as tape-casting, spraying, screen-printing and atmospheric air sintering in the cell production have been selected on condition that up-scaling and cost effective, flexible, industrial mass production are feasible. The standard cell size is currently being increased to 18x18 cm2, and 150 cells of this size have been produced in 2006 for our further stack development. To improve quality and lower production cost, a new screen printing line is under establishment. TOFC's stack design is an ultra compact multilayer assembly of cells (including contact layers), metallic interconnects, spacer frames and glass seals. The compactness ensures minimized material consumption and low cost. Standard stacks with cross flow configuration contains 75 cells (12x12cm2) delivering about 1.2 kW at optimal operation conditions with pre-reformed NG as fuel. Stable performance has been demonstrated for 500-1000 hours. Significantly improved materials, especially concerning the metallic interconnect and the coatings have been introduced during the last year. Small stacks (5-10 cells) exhibit no detectable stack degradation using our latest cells and stack materials during test periods of 500-1000 hours. Larger stacks (50-75 cells) suffer from mal-distribution of gas and air inside the stacks, gas leakage, gas cross-over, pressure drop, and a certain loss of internal electrical contact during operation cycles. Measures have been taken to find solutions during the following development work. The stack production facilities have been improved and up-scaled. In 2006, 5 standard stacks have been assembled and burned in based on

Correlation and Stacking of Relative Paleointensity and Oxygen Isotope Data

Science.gov (United States)

Lurcock, P. C.; Channell, J. E.; Lee, D.

2012-12-01

The transformation of a depth-series into a time-series is routinely implemented in the geological sciences. This transformation often involves correlation of a depth-series to an astronomically calibrated time-series. Eyeball tie-points with linear interpolation are still regularly used, although these have the disadvantages of being non-repeatable and not based on firm correlation criteria. Two automated correlation methods are compared: the simulated annealing algorithm (Huybers and Wunsch, 2004) and the Match protocol (Lisiecki and Lisiecki, 2002). Simulated annealing seeks to minimize energy (cross-correlation) as "temperature" is slowly decreased. The Match protocol divides records into intervals, applies penalty functions that constrain accumulation rates, and minimizes the sum of the squares of the differences between two series while maintaining the data sequence in each series. Paired relative paleointensity (RPI) and oxygen isotope records, such as those from IODP Site U1308 and/or reference stacks such as LR04 and PISO, are warped using known warping functions, and then the un-warped and warped time-series are correlated to evaluate the efficiency of the correlation methods. Correlations are performed in tandem to simultaneously optimize RPI and oxygen isotope data. Noise spectra are introduced at differing levels to determine correlation efficiency as noise levels change. A third potential method, known as dynamic time warping, involves minimizing the sum of distances between correlated point pairs across the whole series. A "cost matrix" between the two series is analyzed to find a least-cost path through the matrix. This least-cost path is used to nonlinearly map the time/depth of one record onto the depth/time of another. Dynamic time warping can be expanded to more than two dimensions and used to stack multiple time-series. This procedure can improve on arithmetic stacks, which often lose coherent high-frequency content during the stacking process.

Implementation of Bluetooth serial port based profiles in embedded systems

Science.gov (United States)

Liu, Guanglei; Qiu, Zhengding; Wang, Quanping; Gao, Qiang

2001-10-01

Bluetooth is a new short-range wireless communication technology developing rapidly in recent years. Bluetooth software architecture consists of stack and profiles. Serial Port Profile (SPP) is an underlying profile that emulates RS232 serial cable connections between two peer devices. Based on SPP, Dial-up Networking (DUN) Profile establishes PPP connection with remote dial-up server, Fax Profile realizes document facsimile function and LAN Access Profile (LAP) provides local area network access service. When it comes to their implementation in embedded systems, there are several challenges such as memory consumption, code efficiency, code reliability, and code portability onto different OS and hardware platforms to be attacked. In this paper, we propose integrated software architecture after discussing the great similarities shared among the three SPP based profiles. Then implementation of the architecture is given, in which OS-dependent and OS-independent parts are clearly separated. Profile interfaces with stack and OS are specified respectively so that the three profiles as a whole can be ported onto various software and hardware platforms easily. As a result, policy of transplanting our implementation onto different platforms is addressed at the end of the paper.

Mechanisms for plasma etching of HfO{sub 2} gate stacks with Si selectivity and photoresist trimming

Energy Technology Data Exchange (ETDEWEB)

Shoeb, Juline; Kushner, Mark J. [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109-2122 (United States)

2009-11-15

To minimize leakage currents resulting from the thinning of the insulator in the gate stack of field effect transistors, high-dielectric constant (high-k) metal oxides, and HfO{sub 2} in particular, are being implemented as a replacement for SiO{sub 2}. To speed the rate of processing, it is desirable to etch the gate stack (e.g., metal gate, antireflection layers, and dielectric) in a single process while having selectivity to the underlying Si. Plasma etching using Ar/BCl{sub 3}/Cl{sub 2} mixtures effectively etches HfO{sub 2} while having good selectivity to Si. In this article, results from integrated reactor and feature scale modeling of gate-stack etching in Ar/BCl{sub 3}/Cl{sub 2} plasmas, preceded by photoresist trimming in Ar/O{sub 2} plasmas, are discussed. It was found that BCl{sub n} species react with HfO{sub 2}, which under ion impact, form volatile etch products such as B{sub m}OCl{sub n} and HfCl{sub n}. Selectivity to Si is achieved by creating Si-B bonding as a precursor to the deposition of a BCl{sub n} polymer which slows the etch rate relative to HfO{sub 2}. The low ion energies required to achieve this selectivity then challenge one to obtain highly anisotropic profiles in the metal gate portion of the stack. Validation was performed with data from literature. The effect of bias voltage and key reactant probabilities on etch rate, selectivity, and profile are discussed.

Variable magnification dual lens electron holography for semiconductor junction profiling and strain mapping.

Science.gov (United States)

Wang, Y Y; Li, J; Domenicucci, A; Bruley, J

2013-01-01

Dual lens operation for electron holography, which was developed previously (Wang et al., Ultramicroscopy 101 (2004) 63-72; US patent: 7,015,469 B2 (2006)), is re-investigated for bright field (junction profiling) and dark field (strain mapping) electron holography using FEI instrumentation (i.e. F20 and Titan). It is found that dual lens operation provides a wide operational range for electron holography. In addition, the dark field image tilt increases at high objective lens current to include Si diffraction spot. Under the condition of high spatial resolution (1 nm fringe spacing), a large field of view (450 nm), and high fringe contrast (26%) with dual lens operation, a junction map is obtained and strain maps of Si device on and diffraction are acquired. In this paper, a fringe quality number, N', which is number of fringe times fringe contrast, is proposed to estimate the quality of an electron hologram and mathematical reasoning for the N' number is provided. Copyright © 2012 Elsevier B.V. All rights reserved.

V-stack piezoelectric actuator

Science.gov (United States)

Ardelean, Emil V.; Clark, Robert L.

2001-07-01

Aeroelastic control of wings by means of a distributed, trailing-edge control surface is of interest with regards to maneuvers, gust alleviation, and flutter suppression. The use of high energy density, piezoelectric materials as motors provides an appealing solution to this problem. A comparative analysis of the state of the art actuators is currently being conducted. A new piezoelectric actuator design is presented. This actuator meets the requirements for trailing edge flap actuation in both stroke and force. It is compact, simple, sturdy, and leverages stroke geometrically with minimum force penalties while displaying linearity over a wide range of stroke. The V-Stack Piezoelectric Actuator, consists of a base, a lever, two piezoelectric stacks, and a pre-tensioning element. The work is performed alternately by the two stacks, placed on both sides of the lever. Pre-tensioning can be readily applied using a torque wrench, obviating the need for elastic elements and this is for the benefit of the stiffness of the actuator. The characteristics of the actuator are easily modified by changing the base or the stacks. A prototype was constructed and tested experimentally to validate the theoretical model.

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.

Mapping forest canopy disturbance in the Upper Great Lakes, USA

Science.gov (United States)

James D. Garner; Mark D. Nelson; Brian G. Tavernia; Charles H. (Hobie) Perry; Ian W. Housman

2015-01-01

A map of forest canopy disturbance was generated for Michigan, Wisconsin, and most of Minnesota using 42 Landsat time series stacks (LTSS) and a vegetation change tracker (VCTw) algorithm. Corresponding winter imagery was used to reduce commission errors of forest disturbance by identifying areas of persistent snow cover. The resulting disturbance age map was classed...

Towards stacked zone plates

International Nuclear Information System (INIS)

Werner, S; Rehbein, S; Guttman, P; Heim, S; Schneider, G

2009-01-01

Fresnel zone plates are the key optical elements for soft and hard x-ray microscopy. For short exposure times and minimum radiation load of the specimen the diffraction efficiency of the zone plate objectives has to be maximized. As the efficiency strongly depends on the height of the diffracting zone structures the achievable aspect ratio of the nanostructures determines these limits. To reach aspect ratios ≥ 20:1 for high efficient optics we propose to superimpose zone plates on top of each other. With this multiplication approach the final aspect ratio is only limited by the number of stacked zone plate layers. For the stack process several nanostructuring process steps have to be developed and/or improved. Our results show for the first time two layers of zone plates stacked on top of each other.

Tunable electro-optic filter stack

Science.gov (United States)

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.

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.

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

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.)

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...

Principles for Instructional Stack Development in HyperCard.

Science.gov (United States)

McEneaney, John E.

The purpose of this paper is to provide information about obtaining and using HyperCard stacks that introduce users to principles of stack development. The HyperCard stacks described are available for downloading free of charge from a server at Indiana University South Bend. Specific directions are given for stack use, with advice for beginners. A…

Using qualimetric engineering and extremal analysis to optimize a proton exchange membrane fuel cell stack

International Nuclear Information System (INIS)

Besseris, George J.

2014-01-01

Highlights: • We consider the optimal configuration of a PEMFC stack. • We utilize qualimetric engineering tools (Taguchi screening, regression analysis). • We achieve analytical solution on a restructured power-law fitting. • We discuss the Pt-cost involvement in the unit and area minimization scope. - Abstract: The optimal configuration of the proton exchange membrane fuel-cell (PEMFC) stack has received attention recently because of its potential use as an isolated energy distributor for household needs. In this work, the original complex problem for generating an optimal PEMFC stack based on the number of cell units connected in series and parallel arrangements as well as on the cell area is revisited. A qualimetric engineering strategy is formulated which is based on quick profiling the PEMFC stack voltage response. Stochastic screening is initiated by employing an L 9 (3 3 ) Taguchi-type OA for partitioning numerically the deterministic expression of the output PEMFC stack voltage such that to facilitate the sizing of the magnitude of the individual effects. The power and current household specifications for the stack system are maintained at the typical settings of 200 W at 12 V, respectively. The minimization of the stack total-area requirement becomes explicit in this work. The relationship of cell voltage against cell area is cast into a power-law model by regression fitting that achieves a coefficient of determination value of 99.99%. Thus, the theoretical formulation simplifies into a non-linear extremal problem with a constrained solution due to a singularity which is solved analytically. The optimal solution requires 22 cell units connected in series where each unit is designed with an area value of 151.4 cm 2 . It is also demonstrated how to visualize the optimal solution using the graphical method of operating lines. The total area of 3270.24 cm 2 becomes a new benchmark for the optimal design of the studied PEMFC stack configuration. It is

Trapping a magnetic field of 7.9 T using a bulk magnet fabricated from stack of coated conductors

International Nuclear Information System (INIS)

Tamegai, T.; Hirai, T.; Sun, Y.; Pyon, S.

2016-01-01

Highlight: • A bulk magnet is fabricated using double stack of coated conductors (CC). • Magneto-optical imaging of the CC confirmed its homogeneity. • The fabricated bulk magnet has successfully trapped a magnetic field of 7.9 T. • The trapped magnetic field is consistent with the magnetic induction calculated from J_c(B) characteristics of the CC. - Abstract: We have fabricated a bulk magnet using double stack, each 130 layers, of short segments of coated conductors (CCs). The bulk magnet is magnetized by field-cooling in a magnetic field of 9 T down to 4.2 K. After reducing the magnetic field down to zero, we have successfully trapped a magnetic field of 7.9 T at the centre of the double stack. The magnetic field profile of the bulk magnet is calculated by fully considering the J_c(B) characteristics of the short segment of the CC. The trapped magnetic field values measured by Hall probes at three locations near the centre of the double stacks agree reasonably well with the calculated magnetic induction.

A superconducting isochronous cyclotron stack as a driver for a thorium-cycle power reactor

International Nuclear Information System (INIS)

Kim, G.; May, D.; McIntyre, P.; Sattarov, A.

2001-01-01

Designs for thorium-cycle power reactors require a proton driver capable of 1 GeV energy and 10 MW total power. For this purpose we have prepared a preliminary design for the magnetic structure for a stack of 5 super-conducting isochronous cyclotrons, each delivering 2 MW beam power. By achieving the required power with multiple independent apertures rather than pushing beyond currently achieved limits, we hope to arrive at a design that is cost-minimum and reliable. Each sector magnet consists of a flux-coupled stack of cold-iron inserts supported within a single warm-iron, in a fashion inspired by the new Riken heavy-ion cyclotron. We have developed a preliminary field design in which in-plane fields are cancelled in all 5 apertures and the field-map is appropriate for the focusing optics of the sector cyclotron

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.

Stacking the Equiangular Spiral

OpenAIRE

Agrawal, A.; Azabi, Y. O.; Rahman, B. M.

2013-01-01

We present an algorithm that adapts the mature Stack and Draw (SaD) methodology for fabricating the exotic Equiangular Spiral Photonic Crystal Fiber. (ES-PCF) The principle of Steiner chains and circle packing is exploited to obtain a non-hexagonal design using a stacking procedure based on Hexagonal Close Packing. The optical properties of the proposed structure are promising for SuperContinuum Generation. This approach could make accessible not only the equiangular spiral but also other qua...

Stochastic stacking without filters

International Nuclear Information System (INIS)

Johnson, R.P.; Marriner, J.

1982-12-01

The rate of accumulation of antiprotons is a critical factor in the design of p anti p colliders. A design of a system to accumulate higher anti p fluxes is presented here which is an alternative to the schemes used at the CERN AA and in the Fermilab Tevatron I design. Contrary to these stacking schemes, which use a system of notch filters to protect the dense core of antiprotons from the high power of the stack tail stochastic cooling, an eddy current shutter is used to protect the core in the region of the stack tail cooling kicker. Without filters one can have larger cooling bandwidths, better mixing for stochastic cooling, and easier operational criteria for the power amplifiers. In the case considered here a flux of 1.4 x 10 8 per sec is achieved with a 4 to 8 GHz bandwidth

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…

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.

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

Constructing Ozone Profile Climatologies with Self-Organizing Maps: Illustrations with CONUS Ozonesonde Data

Science.gov (United States)

Thompson, A. M.; Stauffer, R. M.; Young, G. S.

2015-12-01

Ozone (O3) trends analysis is typically performed with monthly or seasonal averages. Although this approach works well for stratospheric or total O3, uncertainties in tropospheric O3 amounts may be large due to rapid meteorological changes near the tropopause and in the lower free troposphere (LFT) where pollution has a days-weeks lifetime. We use self-organizing maps (SOM), a clustering technique, as an alternative for creating tropospheric climatologies from O3 soundings. In a previous study of 900 tropical ozonesondes, clusters representing >40% of profiles deviated > 1-sigma from mean O­3. Here SOM are based on 15 years of data from four sites in the contiguous US (CONUS; Boulder, CO; Huntsville, AL; Trinidad Head, CA; Wallops Island, VA). Ozone profiles from 2 - 12 km are used to evaluate the impact of tropopause variability on climatology; 2 - 6 km O3 profile segments are used for the LFT. Near-tropopause O­3 is twice the mean O­3 mixing ratio in three clusters of 2 - 12 km O3, representing > 15% of profiles at each site. Large mid and lower-tropospheric O3 deviations from monthly means are found in clusters of both 2 - 12 and 2 - 6 km O3. Positive offsets result from pollution and stratosphere-to-troposphere exchange. In the LFT the lowest tropospheric O3 is associated with subtropical air. Some clusters include profiles with common seasonality but other factors, e.g., tropopause height or LFT column amount, characterize other SOM nodes. Thus, as for tropical profiles, CONUS O­3 averages can be a poor choice for a climatology.

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..

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.

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.

Expected Performance of Ozone Climate Data Records from Ozone Mapping and Profiler Suite Limb Profiler

Science.gov (United States)

Xu, P. Q.; Rault, D. F.; Pawson, S.; Wargan, K.; Bhartia, P. K.

2012-01-01

The Ozone Mapping and Profiler Suite Limb Profiler (OMPS/LP) was launched on board of the Soumi NPP space platform in late October 2011. It provides ozone-profiling capability with high-vertical resolution from 60 Ian to cloud top. In this study, an end-to-end Observing System Simulation Experiment (OSSE) of OMPS/LP ozone is discussed. The OSSE was developed at NASA's Global Modeling and Assimilation Office (GMAO) using the Goddard Earth Observing System (GEOS-5) data assimilation system. The "truth" for this OSSE is built by assimilating MLS profiles and OMI ozone columns, which is known to produce realistic three-dimensional ozone fields in the stratosphere and upper troposphere. OMPS/LP radiances were computed at tangent points computed by an appropriate orbital model. The OMPS/LP forward RT model, Instrument Models (IMs) and EDR retrieval model were introduced and pseudo-observations derived. The resultant synthetic OMPS/LP observations were evaluated against the "truth" and subsequently these observations were assimilated into GEOS-5. Comparison of this assimilated dataset with the "truth" enables comparisons of the likely uncertainties in 3-D analyses of OMPS/LP data. This study demonstrated the assimilation capabilities of OMPS/LP ozone in GEOS-5, with the monthly, zonal mean (O-A) smaller than 0.02ppmv at all levels, the nns(O-A) close to O.lppmv from 100hPa to 0.2hPa; and the mean(O-B) around the 0.02ppmv for all levels. The monthly zonal mean analysis generally agrees to within 2% of the truth, with larger differences of 2-4% (0.1-0.2ppmv) around 10hPa close to North Pole and in the tropical tropopause region, where the difference is above 20% due to the very low ozone concentrations. These OSSEs demonstrated that, within a single data assimilation system and the assumption that assimilated MLS observations provide a true rendition of the stratosphere, the OMPS/LP ozone data are likely to produce accurate analyses through much of the stratosphere

Predicting the liquefaction phenomena from shear velocity profiling: Empirical approach to 6.3 Mw, May 2006 Yogyakarta earthquake

Energy Technology Data Exchange (ETDEWEB)

Hartantyo, Eddy, E-mail: hartantyo@ugm.ac.id [PhD student, Physics Department, FMIPA, UGM. Sekip Utara Yogyakarta 55281 Indonesia (Indonesia); Brotopuspito, Kirbani S.; Sismanto; Waluyo [Geophysics Laboratory, FMIPA, Universitas Gadjah Mada, Sekip Utara Yogyakarta 55281 (Indonesia)

2015-04-24

The liquefactions phenomena have been reported after a shocking 6.5Mw earthquake hit Yogyakarta province in the morning at 27 May 2006. Several researchers have reported the damage, casualties, and soil failure due to the quake, including the mapping and analyzing the liquefaction phenomena. Most of them based on SPT test. The study try to draw the liquefaction susceptibility by means the shear velocity profiling using modified Multichannel Analysis of Surface Waves (MASW). This paper is a preliminary report by using only several measured MASW points. The study built 8-channel seismic data logger with 4.5 Hz geophones for this purpose. Several different offsets used to record the high and low frequencies of surface waves. The phase-velocity diagrams were stacked in the frequency domain rather than in time domain, for a clearer and easier dispersion curve picking. All codes are implementing in Matlab. From these procedures, shear velocity profiling was collected beneath each geophone’s spread. By mapping the minimum depth of shallow water table, calculating PGA with soil classification, using empirical formula for saturated soil weight from shear velocity profile, and calculating CRR and CSR at every depth, the liquefaction characteristic can be identify in every layer. From several acquired data, a liquefiable potential at some depth below water table was obtained.

Variable magnification dual lens electron holography for semiconductor junction profiling and strain mapping

International Nuclear Information System (INIS)

Wang, Y.Y.; Li, J.; Domenicucci, A.; Bruley, J.

2013-01-01

Dual lens operation for electron holography, which was developed previously (Wang et al., Ultramicroscopy 101 (2004) 63–72; US patent: 7,015,469 B2 (2006)), is re-investigated for bright field (junction profiling) and dark field (strain mapping) electron holography using FEI instrumentation (i.e. F20 and Titan). It is found that dual lens operation provides a wide operational range for electron holography. In addition, the dark field image tilt increases at high objective lens current to include Si 〈0 0 4〉 diffraction spot. Under the condition of high spatial resolution (1 nm fringe spacing), a large field of view (450 nm), and high fringe contrast (26%) with dual lens operation, a junction map is obtained and strain maps of Si device on 〈2 2 0〉 and 〈0 0 4〉 diffraction are acquired. In this paper, a fringe quality number, N′, which is number of fringe times fringe contrast, is proposed to estimate the quality of an electron hologram and mathematical reasoning for the N′ number is provided. -- Highlights: ► Dual lens electron holography is implemented on FEI instruments (Titan and F20). ► Wide range of field of view (0.1–0.9 μm) and fringe spacing (0.5–6 nm) is achieved. ► Fringe quality number is proposed to quantify the quality of an electron hologram. ► Junction map at high spatial resolution is provided. ► Strain maps along 〈2 2 0〉 and 〈0 0 4〉 direction of Si by dark field electron holography are reported.

Sharing programming resources between Bio* projects through remote procedure call and native call stack strategies.

Science.gov (United States)

Prins, Pjotr; Goto, Naohisa; Yates, Andrew; Gautier, Laurent; Willis, Scooter; Fields, Christopher; Katayama, Toshiaki

2012-01-01

Open-source software (OSS) encourages computer programmers to reuse software components written by others. In evolutionary bioinformatics, OSS comes in a broad range of programming languages, including C/C++, Perl, Python, Ruby, Java, and R. To avoid writing the same functionality multiple times for different languages, it is possible to share components by bridging computer languages and Bio* projects, such as BioPerl, Biopython, BioRuby, BioJava, and R/Bioconductor. In this chapter, we compare the two principal approaches for sharing software between different programming languages: either by remote procedure call (RPC) or by sharing a local call stack. RPC provides a language-independent protocol over a network interface; examples are RSOAP and Rserve. The local call stack provides a between-language mapping not over the network interface, but directly in computer memory; examples are R bindings, RPy, and languages sharing the Java Virtual Machine stack. This functionality provides strategies for sharing of software between Bio* projects, which can be exploited more often. Here, we present cross-language examples for sequence translation, and measure throughput of the different options. We compare calling into R through native R, RSOAP, Rserve, and RPy interfaces, with the performance of native BioPerl, Biopython, BioJava, and BioRuby implementations, and with call stack bindings to BioJava and the European Molecular Biology Open Software Suite. In general, call stack approaches outperform native Bio* implementations and these, in turn, outperform RPC-based approaches. To test and compare strategies, we provide a downloadable BioNode image with all examples, tools, and libraries included. The BioNode image can be run on VirtualBox-supported operating systems, including Windows, OSX, and Linux.

Spherical Torus Center Stack Design

International Nuclear Information System (INIS)

C. Neumeyer; P. Heitzenroeder; C. Kessel; M. Ono; M. Peng; J. Schmidt; R. Woolley; I. Zatz

2002-01-01

The low aspect ratio spherical torus (ST) configuration requires that the center stack design be optimized within a limited available space, using materials within their established allowables. This paper presents center stack design methods developed by the National Spherical Torus Experiment (NSTX) Project Team during the initial design of NSTX, and more recently for studies of a possible next-step ST (NSST) device

Transition Funding for the Shallow Water Integrated Mapping System SWIMS and Modular Microstructure Profiler MMP

Science.gov (United States)

2013-09-30

the performance of operational and climate models, as well as for understanding local problems such as pollutant dispersal and biological...Mapping System (SWIMS) and Modular Microstructure Profiler (MMP) Matthew H. Alford Applied Physics Laboratory 1013 NE 40th Street Seattle, WA...in Juan de Fuca Submarine Canyon . Measurements were successful. In the next few weeks we will be testing MMP from our local work boat, the R/V Jack

Profile: Asian Americans

Science.gov (United States)

... and Data > Minority Population Profiles > Asian American Profile: Asian Americans Asian American Profile (Map of the US with the top 10 states displaying the largest Asian American population according to the Census Bureau) CA - ...

Heel Effect: Dose Mapping And Profiling For Mobile C-Arm Fluoroscopy Unit Toshiba SXT-1000A

International Nuclear Information System (INIS)

Husaini Salleh; Mohd Khalid Matori; Muhammad Jamal Md Isa; Mohd Ramli Arshad; Shahrul Azlan Azizan; Mohd Firdaus Abdul Rahman; Md Khairusalih Md Zin

2014-01-01

Heel Effect is the well known phenomena in x-ray production. It contributes the effect to image formation and as well as scattered radiation. But there is paucity in the study related to heel effect. This study is for mapping and profiling the dose on the surface of water phantom by using mobile C-arm unit Toshiba SXT-1000A. Based on the result the dose profile is increasing up to about 57 % from anode to cathode bound of the irradiated area. This result and information can be used as a guide to manipulate these phenomena for better image quality and radiation safety for this specific and dedicated fluoroscopy unit. (author)

The untyped stack calculus and Bohm's theorem

Directory of Open Access Journals (Sweden)

Alberto Carraro

2013-03-01

Full Text Available The stack calculus is a functional language in which is in a Curry-Howard correspondence with classical logic. It enjoys confluence but, as well as Parigot's lambda-mu, does not admit the Bohm Theorem, typical of the lambda-calculus. We present a simple extension of stack calculus which is for the stack calculus what Saurin's Lambda-mu is for lambda-mu.

Full Piezoelectric Multilayer-Stacked Hybrid Actuation/Transduction Systems

Science.gov (United States)

Su, Ji; Jiang, Xiaoning; Zu, Tian-Bing

2011-01-01

The Stacked HYBATS (Hybrid Actuation/Transduction system) demonstrates significantly enhanced electromechanical performance by using the cooperative contributions of the electromechanical responses of multilayer, stacked negative strain components and positive strain components. Both experimental and theoretical studies indicate that, for Stacked HYBATS, the displacement is over three times that of a same-sized conventional flextensional actuator/transducer. The coupled resonance mode between positive strain and negative strain components of Stacked HYBATS is much stronger than the resonance of a single element actuation only when the effective lengths of the two kinds of elements match each other. Compared with the previously invented hybrid actuation system (HYBAS), the multilayer Stacked HYBATS can be designed to provide high mechanical load capability, low voltage driving, and a highly effective piezoelectric constant. The negative strain component will contract, and the positive strain component will expand in the length directions when an electric field is applied on the device. The interaction between the two elements makes an enhanced motion along the Z direction for Stacked-HYBATS. In order to dominate the dynamic length of Stacked-HYBATS by the negative strain component, the area of the cross-section for the negative strain component will be much larger than the total cross-section areas of the two positive strain components. The transverse strain is negative and longitudinal strain positive in inorganic materials, such as ceramics/single crystals. Different piezoelectric multilayer stack configurations can make a piezoelectric ceramic/single-crystal multilayer stack exhibit negative strain or positive strain at a certain direction without increasing the applied voltage. The difference of this innovation from the HYBAS is that all the elements can be made from one-of-a-kind materials. Stacked HYBATS can provide an extremely effective piezoelectric

A large sample of shear-selected clusters from the Hyper Suprime-Cam Subaru Strategic Program S16A Wide field mass maps

Science.gov (United States)

Miyazaki, Satoshi; Oguri, Masamune; Hamana, Takashi; Shirasaki, Masato; Koike, Michitaro; Komiyama, Yutaka; Umetsu, Keiichi; Utsumi, Yousuke; Okabe, Nobuhiro; More, Surhud; Medezinski, Elinor; Lin, Yen-Ting; Miyatake, Hironao; Murayama, Hitoshi; Ota, Naomi; Mitsuishi, Ikuyuki

2018-01-01

We present the result of searching for clusters of galaxies based on weak gravitational lensing analysis of the ˜160 deg2 area surveyed by Hyper Suprime-Cam (HSC) as a Subaru Strategic Program. HSC is a new prime focus optical imager with a 1.5°-diameter field of view on the 8.2 m Subaru telescope. The superb median seeing on the HSC i-band images of 0.56" allows the reconstruction of high angular resolution mass maps via weak lensing, which is crucial for the weak lensing cluster search. We identify 65 mass map peaks with a signal-to-noise (S/N) ratio larger than 4.7, and carefully examine their properties by cross-matching the clusters with optical and X-ray cluster catalogs. We find that all the 39 peaks with S/N > 5.1 have counterparts in the optical cluster catalogs, and only 2 out of the 65 peaks are probably false positives. The upper limits of X-ray luminosities from the ROSAT All Sky Survey (RASS) imply the existence of an X-ray underluminous cluster population. We show that the X-rays from the shear-selected clusters can be statistically detected by stacking the RASS images. The inferred average X-ray luminosity is about half that of the X-ray-selected clusters of the same mass. The radial profile of the dark matter distribution derived from the stacking analysis is well modeled by the Navarro-Frenk-White profile with a small concentration parameter value of c500 ˜ 2.5, which suggests that the selection bias on the orientation or the internal structure for our shear-selected cluster sample is not strong.

Sharing programming resources between Bio* projects through remote procedure call and native call stack strategies

DEFF Research Database (Denmark)

Prins, Pjotr; Goto, Naohisa; Yates, Andrew

2012-01-01

Open-source software (OSS) encourages computer programmers to reuse software components written by others. In evolutionary bioinformatics, OSS comes in a broad range of programming languages, including C/C++, Perl, Python, Ruby, Java, and R. To avoid writing the same functionality multiple times...... for different languages, it is possible to share components by bridging computer languages and Bio* projects, such as BioPerl, Biopython, BioRuby, BioJava, and R/Bioconductor. In this chapter, we compare the two principal approaches for sharing software between different programming languages: either by remote...... procedure call (RPC) or by sharing a local call stack. RPC provides a language-independent protocol over a network interface; examples are RSOAP and Rserve. The local call stack provides a between-language mapping not over the network interface, but directly in computer memory; examples are R bindings, RPy...

Simple Stacking Methods for Silicon Micro Fuel Cells

Directory of Open Access Journals (Sweden)

Gianmario Scotti

2014-08-01

Full Text Available We present two simple methods, with parallel and serial gas flows, for the stacking of microfabricated silicon fuel cells with integrated current collectors, flow fields and gas diffusion layers. The gas diffusion layer is implemented using black silicon. In the two stacking methods proposed in this work, the fluidic apertures and gas flow topology are rotationally symmetric and enable us to stack fuel cells without an increase in the number of electrical or fluidic ports or interconnects. Thanks to this simplicity and the structural compactness of each cell, the obtained stacks are very thin (~1.6 mm for a two-cell stack. We have fabricated two-cell stacks with two different gas flow topologies and obtained an open-circuit voltage (OCV of 1.6 V and a power density of 63 mW·cm−2, proving the viability of the design.

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.

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.

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.

Combining hyperspectral imagery and legacy measured soil profiles to map subsurface soil properties in a Mediterranean area (Cap-Bon, Tunisia)

Science.gov (United States)

Lagacherie, Philippe; Sneep, Anne-Ruth; Gomez, Cécile

2013-04-01

Previous studies have demonstrated that Visible Near InfraRed (Vis-NIR) Hyperspectral imagery is a cost-efficient way for mapping soil properties at fine resolutions (~5m) over large areas. However, such mapping is only feasible for soil surface since the effective penetration depths of optical sensors do not exceed several millimetres. This study aimed to extend the use of Vis-NIR hyperspectral imagery to the mapping of subsurface properties at three intervals of depth (15-30 cm, 30-60 cm and 60-100 cm) as specified by the GlobalSoilMap project. To avoid additional data collection, our basic idea was to develop an original Digital Soil Mapping approach that combines the digital maps of surface soil properties obtained from Vis-NIR hyperspectral imagery with legacy soil profiles of the region and with easily available images of DEM-derived parameters. The study was conducted in a pedologically-contrasted 300km² cultivated area located in the Cap Bon region (Northern Tunisia). AISA-Dual Vis-NIR hyperspectral airborne data were acquired over the studied area with a fine spatial resolution (5 m) and fine spectral resolution (260 spectral bands from 450 to 2500nm). Vegetated surfaces were masked to conserve only bare soil surface which represented around 50% of the study area. Three soil surface properties (clay and sand contents, Cation Exchange Capacity) were successfully mapped over the bare soils, from these data using Partial Least Square Regression models (R2 > 0.7). We used as additional data a set of images of landscape covariates derived from a 30 meter DEM and a local database of 152 legacy soil profiles from which soil properties values at the required intervals of depths were computed using an equal-area-spline algorithm. Our Digital Soil Mapping approach followed two steps: i) the development of surface-subsurface functions - linear models and random forests - that estimates subsurface property values from surface ones and landscape covariates and that

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.

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...

On the measurement of the stacking-fault energies of face centered cubic metal and austenitic stainless steels by X-ray diffraction

International Nuclear Information System (INIS)

Borges, J.F.A.

1985-01-01

An X-rays diffraction method was applied to measure the Stacking-Fault Energies (SFE) of the AISI 304, AISI 316, AISI 347 and DIN-WERKSTOFF 1.4970 Austenitic Stainless Steels. The SFE determination plays an important role in the research of the mechanical behaviour of the Metal and Alloys, their deformation mechanisms, stability of microstructure amd electronic configuration. The method is based on the relationship between the SFE and the ratio of the Mean Square Strain to the Stacking-Fault probability. The Mean Square Strain was evaluated by Fourier Analysis of X-rays Diffraction profiles, corrected to reduce instrumental effects, followed by the application of the Warren-Averbach method to the Fourier Coefficients. The Stacking-Fault probabilities were derived from the changes of peak separations between cold-worked and annealed specimens. (author) [pt

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

Trace interpolation by slant-stack migration

International Nuclear Information System (INIS)

Novotny, M.

1990-01-01

The slant-stack migration formula based on the radon transform is studied with respect to the depth steep Δz of wavefield extrapolation. It can be viewed as a generalized trace-interpolation procedure including wave extrapolation with an arbitrary step Δz. For Δz > 0 the formula yields the familiar plane-wave decomposition, while for Δz > 0 it provides a robust tool for migration transformation of spatially under sampled wavefields. Using the stationary phase method, it is shown that the slant-stack migration formula degenerates into the Rayleigh-Sommerfeld integral in the far-field approximation. Consequently, even a narrow slant-stack gather applied before the diffraction stack can significantly improve the representation of noisy data in the wavefield extrapolation process. The theory is applied to synthetic and field data to perform trace interpolation and dip reject filtration. The data examples presented prove that the radon interpolator works well in the dip range, including waves with mutual stepouts smaller than half the dominant period

Development of Auto-Stacking Warehouse Truck

Directory of Open Access Journals (Sweden)

Kuo-Hsien Hsia

2018-03-01

Full Text Available Warehouse automation is a very important issue for the promotion of traditional industries. For the production of larger and stackable products, it is usually necessary to operate a fork-lifter for the stacking and storage of the products by a skilled person. The general autonomous warehouse-truck does not have the ability of stacking objects. In this paper, we develop a prototype of auto-stacking warehouse-truck that can work without direct operation by a skill person. With command made by an RFID card, the stacker truck can take the packaged product to the warehouse on the prior-planned route and store it in a stacking way in the designated storage area, or deliver the product to the shipping area or into the container from the storage area. It can significantly reduce the manpower requirements of the skilled-person of forklift technician and improve the safety of the warehousing area.

Variable magnification dual lens electron holography for semiconductor junction profiling and strain mapping

Energy Technology Data Exchange (ETDEWEB)

Wang, Y.Y., E-mail: wangyy@us.ibm.com [IBM Micro-electronics Division, Zip 40E, Hudson Valley Research Park, 2070 Route 52, Hopewell Junction, NY 12533 (United States); Li, J.; Domenicucci, A. [IBM Micro-electronics Division, Zip 40E, Hudson Valley Research Park, 2070 Route 52, Hopewell Junction, NY 12533 (United States); Bruley, J. [IBM TJ Watson Research Center, 1101 Kitchawan Road, Route 134 Yorktown Heights, NY 10598 (United States)

2013-01-15

Dual lens operation for electron holography, which was developed previously (Wang et al., Ultramicroscopy 101 (2004) 63-72; US patent: 7,015,469 B2 (2006)), is re-investigated for bright field (junction profiling) and dark field (strain mapping) electron holography using FEI instrumentation (i.e. F20 and Titan). It is found that dual lens operation provides a wide operational range for electron holography. In addition, the dark field image tilt increases at high objective lens current to include Si Left-Pointing-Angle-Bracket 0 0 4 Right-Pointing-Angle-Bracket diffraction spot. Under the condition of high spatial resolution (1 nm fringe spacing), a large field of view (450 nm), and high fringe contrast (26%) with dual lens operation, a junction map is obtained and strain maps of Si device on Left-Pointing-Angle-Bracket 2 2 0 Right-Pointing-Angle-Bracket and Left-Pointing-Angle-Bracket 0 0 4 Right-Pointing-Angle-Bracket diffraction are acquired. In this paper, a fringe quality number, N Prime , which is number of fringe times fringe contrast, is proposed to estimate the quality of an electron hologram and mathematical reasoning for the N Prime number is provided. -- Highlights: Black-Right-Pointing-Pointer Dual lens electron holography is implemented on FEI instruments (Titan and F20). Black-Right-Pointing-Pointer Wide range of field of view (0.1-0.9 {mu}m) and fringe spacing (0.5-6 nm) is achieved. Black-Right-Pointing-Pointer Fringe quality number is proposed to quantify the quality of an electron hologram. Black-Right-Pointing-Pointer Junction map at high spatial resolution is provided. Black-Right-Pointing-Pointer Strain maps along Left-Pointing-Angle-Bracket 2 2 0 Right-Pointing-Angle-Bracket and Left-Pointing-Angle-Bracket 0 0 4 Right-Pointing-Angle-Bracket direction of Si by dark field electron holography are reported.

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...

SOFC - Manufacture of stacks for test and demonstration related activities, stack and system tests and identification of end user requirements. Final report

Energy Technology Data Exchange (ETDEWEB)

Jacobsen, Joachim; Primdahl, S.; Boegh Elmose, H.; Weineisen, H.; Richter, A.

2008-11-15

The aim of the project was to solve the technical challenges in relation to stack functionality in connection with operation of multi stack assemblies under realistic operating conditions. It was the intention to make a targeted effort with the aim of developing a high performance stack technology suitable for both small and large units. An important part of the project was the testing of stack assemblies up to 10 kW power range with relevant fuel and realistic operation condition in the test facility at HC OErstedvaerket. The manufacturing of stacks in the project was as planned a number of stacks (70 kW) for use in demonstration projects both for single stacks and for multi stack assemblies. The start up of the work on the SOFC test facility at HC OErstedsvaerket (HCV) was delayed due to a late delivery of the unit from the PSO 6385 project. A number of unforeseen events during the project have meant that the SOFC test facility at HCV has not until now been ready for performing tests. The experience gained from the operation of a 20 kW Alpha unit in a co-operation between TOFC and Waertsilae now provides an important contribution to the future multi stack assemblies. The work on identification of end user requirements has resulted in a number of different development priorities for the m-CHP and the Distributed Generation market segments. (au)

Synthesis of carbon nanotubes from palm oil on stacking and non-stacking substrate by thermal-CVD method

Science.gov (United States)

Robaiah, M.; Rusop, M.; Abdullah, S.; Khusaimi, Z.; Azhan, H.; Fadzlinatul, M. Y.; Salifairus, M. J.; Asli, N. A.

2018-05-01

Palm oil has been used as the carbon source to synthesize carbon nanotubes (CNTs) on silicon substrates using the thermal chemical vapor deposition (CVD) method. Meanwhile, silicon has been applied using two techniques, which are stacked technique and non-stacked technique. The CNTs were grown at the constant time of 30 minutes with various synthesis temperatures of 750 °C, 850 °C and 950 °C. The CNTs were characterized using micro-Raman spectroscopy and field emission scanning electron microscopy (FESEM). It was found that the density, growth rate, diameter and length of the CNTs produced were affected by the synthesis temperature. Moreover, the structure slightly changes were observed between CNTs obtained in SS and NSS. The synthesize temperature of 750 °C was considered as the suitable temperature for the production of CNTs due to low ID/IG ratio, which for stacked is 0.89 and non-stacked are 0.90. The possible explanation for the different morphology of the produced CNTs was also discussed.

From the Catalog to the Book on the Shelf: Building a Mapping Application for Vufind

Directory of Open Access Journals (Sweden)

Kathleen Bauer

2012-06-01

Full Text Available At Yale University Library (YUL, recorded reference transactions revealed that after finding a book in the catalog patrons had difficulty knowing how to use the call number to find the book on the shelf. The Library created a mobile service to help locate the call number in the library stacks. From any call number of a book in Sterling Memorial Library at YUL, a map will be displayed which highlights that call number’s general area on a floor in the stacks. YUL introduced the mapping application in Yufind, a catalog in place at Yale since 2008 which is based on Vufind.

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.

Numerical model for stack gas diffusion in terrain with buildings. Variations in air flow and gas concentration with additional building near stack

International Nuclear Information System (INIS)

Sada, Koichi; Michioka, Takenobu; Ichikawa, Yoichi; Komiyama, Sumito; Numata, Kunio

2009-01-01

A numerical simulation method for predicting atmospheric flow and stack gas diffusion using a calculation domain of several km around a stack under complex terrain conditions containing buildings has been developed. The turbulence closure technique using a modified k-ε-type model without a hydrostatic approximation was used for flow calculation, and some of the calculation grids near the ground were treated as buildings using a terrain-following coordinate system. Stack gas diffusion was predicted using the Lagrangian particle model, that is, the stack gas was represented by trajectories of released particles. The developed numerical model was applied to a virtual terrain and building conditions in this study prior to the applications of a numerical model for real terrain and building conditions. The height of the additional building (H a ), located about 200 m leeward from the stack, was varied (i.e., H a =0, 20, 30 and 50 m), and its effects on airflow and the concentration of stack gas at a released height of 75 m were calculated. Furthermore, effective stack height, which was used in the safety analysis of atmospheric diffusion for nuclear facilities in Japan, was evaluated from the calculated ground-level concentration of stack gas. The cavity region behind the additional building was calculated, and turbulence near the cavity was observed to decrease when the additional building was present. According to these flow variations with the additional building, tracer gas tended to diffuse to the ground surface rapidly with the additional building at the leeward position of the cavity, and the ground-level stack gas concentration along the plume axis also increased with the height of the additional building. However, the variations in effective stack height with the height of the additional building were relatively small and ranged within several m in this study. (author)

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.

Profiling a Mind Map User: A Descriptive Appraisal

Science.gov (United States)

Tucker, Joanne M.; Armstrong, Gary R.; Massad, Victor J.

2010-01-01

Whether manually or through the use of software, a non-linear information organization framework known as mind mapping offers an alternative method for capturing thoughts, ideas and information to linear thinking modes such as outlining. Mind mapping is brainstorming, organizing, and problem solving. This paper examines mind mapping techniques,…

High-Density Stacked Ru Nanocrystals for Nonvolatile Memory Application

International Nuclear Information System (INIS)

Ping, Mao; Zhi-Gang, Zhang; Li-Yang, Pan; Jun, Xu; Pei-Yi, Chen

2009-01-01

Stacked ruthenium (Ru) nanocrystals (NCs) are formed by rapid thermal annealing for the whole gate stacks and embedded in memory structure, which is compatible with conventional CMOS technology. Ru NCs with high density (3 × 10 12 cm −2 ), small size (2–4 nm) and good uniformity both in aerial distribution and morphology are formed. Attributed to the higher surface trap density, a memory window of 5.2 V is obtained with stacked Ru NCs in comparison to that of 3.5 V with single-layer samples. The stacked Ru NCs device also exhibits much better retention performance because of Coulomb blockade and vertical uniformity between stacked Ru NCs

NOAA JPSS Ozone Mapping and Profiler Suite (OMPS) Version 8 Total Ozone (V8TOz) Environmental Data Record (EDR) from NDE

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a high quality operational Environmental Data Record (EDR) of total column ozone from the Ozone Mapping and Profiling Suite (OMPS) instrument...

Vertical melting of a stack of membranes

Science.gov (United States)

Borelli, M. E. S.; Kleinert, H.; Schakel, A. M. J.

2001-02-01

A stack of tensionless membranes with nonlinear curvature energy and vertical harmonic interaction is studied. At low temperatures, the system forms a lamellar phase. At a critical temperature, the stack disorders vertically in a melting-like transition.

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.

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.

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.

Dimensional crossover of electron weak localization in ZnO/TiO{sub x} stacked layers grown by atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Saha, D., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Misra, P., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Joshi, M. P.; Kukreja, L. M. [Laser Materials Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Bhartiya, S. [Laser Materials Development & Devices Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Gupta, M. [UGC-DAE Consortium for Scientific Research, Indore 452 017 (India)

2016-01-25

We report on the dimensional crossover of electron weak localization in ZnO/TiO{sub x} stacked layers having well-defined and spatially-localized Ti dopant profiles along film thickness. These films were grown by in situ incorporation of sub-monolayer TiO{sub x} on the growing ZnO film surface and subsequent overgrowth of thin conducting ZnO spacer layer using atomic layer deposition. Film thickness was varied in the range of ∼6–65 nm by vertically stacking different numbers (n = 1–7) of ZnO/TiO{sub x} layers of nearly identical dopant-profiles. The evolution of zero-field sheet resistance (R{sub ◻}) versus temperature with decreasing film thickness showed a metal to insulator transition. On the metallic side of the metal-insulator transition, R{sub ◻}(T) and magnetoresistance data were found to be well corroborated with the theoretical framework of electron weak localization in the diffusive transport regime. The temperature dependence of both R{sub ◻} and inelastic scattering length provided strong evidence for a smooth crossover from 2D to 3D weak localization behaviour. Results of this study provide deeper insight into the electron transport in low-dimensional n-type ZnO/TiO{sub x} stacked layers which have potential applications in the field of transparent oxide electronics.

Turbostratic stacked CVD graphene for high-performance devices

Science.gov (United States)

Uemura, Kohei; Ikuta, Takashi; Maehashi, Kenzo

2018-03-01

We have fabricated turbostratic stacked graphene with high-transport properties by the repeated transfer of CVD monolayer graphene. The turbostratic stacked CVD graphene exhibited higher carrier mobility and conductivity than CVD monolayer graphene. The electron mobility for the three-layer turbostratic stacked CVD graphene surpassed 10,000 cm2 V-1 s-1 at room temperature, which is five times greater than that for CVD monolayer graphene. The results indicate that the high performance is derived from maintenance of the linear band dispersion, suppression of the carrier scattering, and parallel conduction. Therefore, turbostratic stacked CVD graphene is a superior material for high-performance devices.

OpenStack augstas pieejamības risinājumi

OpenAIRE

Dreiže, Toms

2016-01-01

Šis bakalaura darbs ir pētījums par OpenStack IaaS mākoņpakalpojumu platformu. Tā mērķis ir sniegt ieskatu augstas pieejamības pamatprincipos un OpenStack mākoņpakalpojumu platformas piedāvātajos augstas pieejamības nodrošināšanas risinājumos. Bakalaura darba gaitā ir veikta augsti pieejamas OpenStack trīs mezglu sistēmas uzstādīšana, izmantojot Galera Cluster datubāzu klasteri un HAProxy slodzes līdzsvarotāju. Tika pārbaudīta OpenStack augsta pieejamība, testējot OpenStack Glance komponentes...

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)

High resolution reflection seismic mapping of shallow coal seams

CSIR Research Space (South Africa)

Mngadi, SB

2013-10-01

Full Text Available the extent of the mine workings. Two 94 m profiles (tied to boreholes) were surveyed using a sledgehammer source. Processing was optimized to image the shallow reflections. The refraction seismic models and stacked time sections were compared and integrated...

400 W High Temperature PEM Fuel Cell Stack Test

DEFF Research Database (Denmark)

Andreasen, Søren Juhl; Kær, Søren Knudsen

2006-01-01

This work demonstrates the operation of a 30 cell high temperature PEM (HTPEM) fuel cell stack. This prototype stack has been developed at the Institute of Energy Technology, Aalborg University, as a proof-of-concept for a low pressure cathode air cooled HTPEM stack. The membranes used are Celtec...

Barrier inhomogeneities at vertically stacked graphene-based heterostructures.

Science.gov (United States)

Lin, Yen-Fu; Li, Wenwu; Li, Song-Lin; Xu, Yong; Aparecido-Ferreira, Alex; Komatsu, Katsuyoshi; Sun, Huabin; Nakaharai, Shu; Tsukagoshi, Kazuhito

2014-01-21

The integration of graphene and other atomically flat, two-dimensional materials has attracted much interest and been materialized very recently. An in-depth understanding of transport mechanisms in such heterostructures is essential. In this study, vertically stacked graphene-based heterostructure transistors were manufactured to elucidate the mechanism of electron injection at the interface. The temperature dependence of the electrical characteristics was investigated from 300 to 90 K. In a careful analysis of current-voltage characteristics, an unusual decrease in the effective Schottky barrier height and increase in the ideality factor were observed with decreasing temperature. A model of thermionic emission with a Gaussian distribution of barriers was able to precisely interpret the conduction mechanism. Furthermore, mapping of the effective Schottky barrier height is unmasked as a function of temperature and gate voltage. The results offer significant insight for the development of future layer-integration technology based on graphene-based heterostructures.

Dynamic Model of High Temperature PEM Fuel Cell Stack Temperature

DEFF Research Database (Denmark)

Andreasen, Søren Juhl; Kær, Søren Knudsen

2007-01-01

cathode air cooled 30 cell HTPEM fuel cell stack developed at the Institute of Energy Technology at Aalborg University. This fuel cell stack uses PEMEAS Celtec P-1000 membranes, runs on pure hydrogen in a dead end anode configuration with a purge valve. The cooling of the stack is managed by running......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...... 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...

Linkage mapping of putative regulator genes of barley grain development characterized by expression profiling

Directory of Open Access Journals (Sweden)

Wobus Ulrich

2009-01-01

Full Text Available Abstract Background Barley (Hordeum vulgare L. seed development is a highly regulated process with fine-tuned interaction of various tissues controlling distinct physiological events during prestorage, storage and dessication phase. As potential regulators involved within this process we studied 172 transcription factors and 204 kinases for their expression behaviour and anchored a subset of them to the barley linkage map to promote marker-assisted studies on barley grains. Results By a hierachical clustering of the expression profiles of 376 potential regulatory genes expressed in 37 different tissues, we found 50 regulators preferentially expressed in one of the three grain tissue fractions pericarp, endosperm and embryo during seed development. In addition, 27 regulators found to be expressed during both seed development and germination and 32 additional regulators are characteristically expressed in multiple tissues undergoing cell differentiation events during barley plant ontogeny. Another 96 regulators were, beside in the developing seed, ubiquitously expressed among all tissues of germinating seedlings as well as in reproductive tissues. SNP-marker development for those regulators resulted in anchoring 61 markers on the genetic linkage map of barley and the chromosomal assignment of another 12 loci by using wheat-barley addition lines. The SNP frequency ranged from 0.5 to 1.0 SNP/kb in the parents of the various mapping populations and was 2.3 SNP/kb over all eight lines tested. Exploration of macrosynteny to rice revealed that the chromosomal orders of the mapped putative regulatory factors were predominantly conserved during evolution. Conclusion We identified expression patterns of major transcription factors and signaling related genes expressed during barley ontogeny and further assigned possible functions based on likely orthologs functionally well characterized in model plant species. The combined linkage map and reference

Enhancement of stack ventilation in hot and humid climate using a combination of roof solar collector and vertical stack

Energy Technology Data Exchange (ETDEWEB)

Yusoff, Wardah Fatimah Mohammad; Salleh, Elias [Department of Architecture, Faculty of Design and Architecture, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Adam, Nor Mariah [Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Sapian, Abdul Razak [Department of Architecture, Kulliyyah of Architecture and Environmental Design, International Islamic University Malaysia, P.O. Box 10, 50728 Kuala Lumpur (Malaysia); Yusof Sulaiman, Mohamad [Solar Energy Research Institute, 3rd Floor, Tun Sri Lanang Library Building, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

2010-10-15

In the hot and humid climate, stack ventilation is inefficient due to small temperature difference between the inside and outside of naturally ventilated buildings. Hence, solar induced ventilation is a feasible alternative in enhancing the stack ventilation. This paper aims to investigate the effectiveness of a proposed solar induced ventilation strategy, which combines a roof solar collector and a vertical stack, in enhancing the stack ventilation performance in the hot and humid climate. The methodology selected for the investigation is physical experimental modelling which was carried out in the actual environment. The results are presented and discussed in terms of two performance variables: air temperature and air velocity. The findings indicate that the proposed strategy is able to enhance the stack ventilation, both in semi-clear sky and overcast sky conditions. The highest air temperature difference between the air inside the stack and the ambient air (T{sub i}-T{sub o}) is achieved in the semi-clear sky condition, which is about 9.9 C (45.8 C-35.9 C). Meanwhile, in the overcast sky condition, the highest air temperature difference (T{sub i}-T{sub o}) is 6.2 C (39.3 C-33.1 C). The experimental results also indicate good agreement with the theoretical results for the glass temperature, the air temperature in the roof solar collector's channel and the absorber temperature. The findings also show that wind has significant effect to the induced air velocity by the proposed strategy. (author)

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.

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.

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.

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.

Method for applying a thin film barrier stack to a device with microstructures, and device provided with such a thin film barrier stack

NARCIS (Netherlands)

2005-01-01

A method for applying a thin film barrier stack to a device with microstructures, such as, for instance, an OLED, wherein the thin film barrier stack forms a barrier to at least moisture and oxygen, wherein the stack is built up from a combination of org. and inorg. layers, characterized in that a

Airborne gamma-ray spectrometer and magnetometer survey: Kingston quadrangle (New York). Final report

International Nuclear Information System (INIS)

1981-01-01

No uranium anomalies meet the minimum statistical requirements as defined in Volume I. There is no Uranium Anomaly Map for this volume. Potassium (%K), equivalent Uranium (ppm eU), equivalent Thorium (ppm eTh), eU/eTh, eU/K, eTh/K, and magnetic pseudo-contour maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation in Volume II

Airborne gamma-ray spectrometer and magnetometer survey: Toronto quadrangle (New York). Final report

International Nuclear Information System (INIS)

1981-01-01

No uranium anomalies meet the minimum statistical requirements as defined in Volume I. There is no Uranium Anomaly Map for this volume. Potassium (%K), equivalent Uranium (ppm eU), equivalent Thorium (ppm eTh), eU/eTh, eU/K, eTh/K, and magnetic pseudo-contour maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation in Volume II

Airborne gamma-ray spectrometer and magnetometer survey, Copalis Beach quadrangle (Washington). Final report

International Nuclear Information System (INIS)

1981-01-01

No uranium anomalies meet the minimum statistical requirements as defined. There is no Uranium Anomaly Interpretation Map for the Copalis Beach quadrangle. Potassium (%K), equivalent Uranium (ppM eU), equivalent Thorium (ppM eT), eU/eT, eU/K, eT/K, and magnetic pseudo-contour maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation

Stack Monitor Operating Experience Review

International Nuclear Information System (INIS)

Cadwallader, L.C.; Bruyere, S.A.

2009-01-01

Stack monitors are used to sense radioactive particulates and gases in effluent air being vented from rooms of nuclear facilities. These monitors record the levels and types of effluents to the environment. This paper presents the results of a stack monitor operating experience review of the U.S. Department of Energy (DOE) Occurrence Reporting and Processing System (ORPS) database records from the past 18 years. Regulations regarding these monitors are briefly described. Operating experiences reported by the U.S. DOE and in engineering literature sources were reviewed to determine the strengths and weaknesses of these monitors. Electrical faults, radiation instrumentation faults, and human errors are the three leading causes of failures. A representative 'all modes' failure rate is 1E-04/hr. Repair time estimates vary from an average repair time of 17.5 hours (with spare parts on hand) to 160 hours (without spare parts on hand). These data should support the use of stack monitors in any nuclear facility, including the National Ignition Facility and the international ITER project.

Study and Development of an OpenStack solution

OpenAIRE

Jorba Brosa, Maria

2014-01-01

Estudi i desenvolupament d'una solució de virtualització amb Openstack. Es farà un especial èmfasi en la part de seguretat. Deployment of a solution based in OpenStack for the creation of an Infrastructure service cloud. Implementación de una solución basada en OpenStack para la creación de una infrastructura de servicios cloud. Implementació d'una solució basada en OpenStack per la creació d'una infrastructura de serveis cloud.

High efficiency x-ray nanofocusing by the blazed stacking of binary zone plates

Science.gov (United States)

Mohacsi, I.; Karvinen, P.; Vartiainen, I.; Diaz, A.; Somogyi, A.; Kewish, C. M.; Mercere, P.; David, C.

2013-09-01

The focusing efficiency of binary Fresnel zone plate lenses is fundamentally limited and higher efficiency requires a multi step lens profile. To overcome the manufacturing problems of high resolution and high efficiency multistep zone plates, we investigate the concept of stacking two different binary zone plates in each other's optical near-field. We use a coarse zone plate with π phase shift and a double density fine zone plate with π/2 phase shift to produce an effective 4- step profile. Using a compact experimental setup with piezo actuators for alignment, we demonstrated 47.1% focusing efficiency at 6.5 keV using a pair of 500 μm diameter and 200 nm smallest zone width. Furthermore, we present a spatially resolved characterization method using multiple diffraction orders to identify manufacturing errors, alignment errors and pattern distortions and their effect on diffraction efficiency.

Exploring online evolution of network stacks

OpenAIRE

Imai, Pierre

2013-01-01

Network stacks today follow a one-size-fits-all philosophy. They are mostly kept unmodified due to often prohibitive costs of engineering, deploying and administrating customisation of the networking software, with the Internet stack architecture still largely being based on designs and assumptions made for the ARPANET 40 years ago. We venture that heterogeneous and rapidly changing networks of the future require, in order to be successful, run-time self-adaptation mechanisms at different tim...

Visualization of Disciplinary Profiles: Enhanced Science Overlay Maps

Directory of Open Access Journals (Sweden)

Stephen Carley

2017-08-01

Full Text Available Purpose: The purpose of this study is to modernize previous work on science overlay maps by updating the underlying citation matrix, generating new clusters of scientific disciplines, enhancing visualizations, and providing more accessible means for analysts to generate their own maps. Design/methodology/approach: We use the combined set of 2015 Journal Citation Reports for the Science Citation Index (n of journals = 8,778 and the Social Sciences Citation Index (n = 3,212 for a total of 11,365 journals. The set of Web of Science Categories in the Science Citation Index and the Social Sciences Citation Index increased from 224 in 2010 to 227 in 2015. Using dedicated software, a matrix of 227 × 227 cells is generated on the basis of whole-number citation counting. We normalize this matrix using the cosine function. We first develop the citing-side, cosine-normalized map using 2015 data and VOSviewer visualization with default parameter values. A routine for making overlays on the basis of the map (“wc15.exe” is available at http://www.leydesdorff.net/wc15/index.htm. Findings: Findings appear in the form of visuals throughout the manuscript. In Figures 1–9 we provide basemaps of science and science overlay maps for a number of companies, universities, and technologies. Research limitations: As Web of Science Categories change and/or are updated so is the need to update the routine we provide. Also, to apply the routine we provide users need access to the Web of Science. Practical implications: Visualization of science overlay maps is now more accurate and true to the 2015 Journal Citation Reports than was the case with the previous version of the routine advanced in our paper. Originality/value: The routine we advance allows users to visualize science overlay maps in VOSviewer using data from more recent Journal Citation Reports.

Stacking fault energy measurements in solid solution strengthened Ni-Cr-Fe alloys using synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Unfried-Silgado, Jimy [Metals Characterization and Processing Laboratory, Brazilian Nanothecnology National Laboratory - CNPEM/ABTLuS, Caixa Postal 6192, CEP 13083-970, Campinas, Sao Paulo (Brazil); Universidade Estadual de Campinas UNICAMP, Faculdade de Engenharia Mecanica FEM, Campinas (Brazil); Universidad Autonoma del Caribe, Grupo IMTEF, Ingenieria Mecanica, Barranquilla (Colombia); Wu, Leonardo [Metals Characterization and Processing Laboratory, Brazilian Nanothecnology National Laboratory - CNPEM/ABTLuS, Caixa Postal 6192, CEP 13083-970, Campinas, Sao Paulo (Brazil); Furlan Ferreira, Fabio [Universidade Federal do ABC, Centro de Ciencias Naturais e Humanas (CCNH), Sao Paulo (Brazil); Mario Garzon, Carlos [Universidad Nacional de Colombia, Departamento de Fisica, Bogota (Colombia); Ramirez, Antonio J, E-mail: antonio.ramirez@lnnano.org.br [Metals Characterization and Processing Laboratory, Brazilian Nanothecnology National Laboratory - CNPEM/ABTLuS, Caixa Postal 6192, CEP 13083-970, Campinas, Sao Paulo (Brazil)

2012-12-15

The stacking fault energy (SFE) in a set of experimental Ni-Cr-Fe alloys was determined using line profile analysis on synchrotron X-ray diffraction measurements. The methodology used here is supported by the Warren-Averbach calculations and the relationships among the stacking fault probability ({alpha}) and the mean-square microstrain (<{epsilon}{sup 2}{sub L}>). These parameters were obtained experimentally from cold-worked and annealed specimens extracted from the set of studied Ni-alloys. The obtained results show that the SFE in these alloys is strongly influenced by the kind and quantity of addition elements. Different effects due to the action of carbide-forming elements and the solid solution hardening elements on the SFE are discussed here. The simultaneous addition of Nb, Hf, and, Mo, in the studied Ni-Cr-Fe alloys have generated the stronger decreasing of the SFE. The relationships between SFE and the contributions on electronic structure from each element of additions were established.

Radiation damage and life-time evaluation of RBMK graphite stack

Energy Technology Data Exchange (ETDEWEB)

Platonov, P A; Chugunov, O K; Manevsky, V N; Karpukhin, V I [Russian Research Centre Kurchatov Inst., Moscow (Russian Federation). Reactor Material Div.

1996-08-01

At the present time there are 11 NPP units with RBMK reactors in operation in Russia, with the oldest now in operation 22 years. Design life-time of the RBMK-1000 reactor is 30 years. This paper addresses the evaluation of RBMK graphite stack life-time. It is the practice in Russia to evaluate the reliability of the channel reactor graphite stack using at least three criteria: degradation of physical-mechanical properties of graphite, preservation of the graphite brick integrity, and degradation of the graphite stack as a structure. Stack life-time evaluation by different criteria indicates that the most realistic approach may be realized on the basis of the criteria of brick cracking and degradation of the graphite stack as a structure. The RBMK reactor graphite stack life-time depends on its temperature and for different units it may be different. (author). 2 refs, 10 figs.

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....

A high-performance aluminum-feed microfluidic fuel cell stack

Science.gov (United States)

Wang, Yifei; Leung, Dennis Y. C.

2016-12-01

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

Visualization of disciplinary profiles: Enhanced science overlay maps

NARCIS (Netherlands)

Carley, S.; Porter, A.L.; Rafols, I.; Leydesdorff, L.

Purpose The purpose of this study is to modernize previous work on science overlay maps by updating the underlying citation matrix, generating new clusters of scientific disciplines, enhancing visualizations, and providing more accessible means for analysts to generate their own maps.

Dynamic stack testing and HiL simulation

Energy Technology Data Exchange (ETDEWEB)

Randolf, G. [GRandalytics, Honolulu, HI (United States)

2009-07-01

The applications for fuel cell and stack deployment have changed rapidly over the years, from stationary backup supplies to highly dynamic automotive power systems. As a result, testing must keep up in order to ensure mature products of high quality. A new breed of stack test stations has been designed, based on a newly developed single cell, high dynamic hardware-in-the-loop (HiL) simulator in order to meet the growing demand of realistic fuel cell testing scenarios for aviation and automotive industries. The paper described and illustrated the test station architecture and outline of communication nodes. The paper also described the voltage monitor and presented schematics of voltage monitoring modules. The basic requirements of the architecture that were presented included low latency; flexible communication with simulation targets and other data input/output nodes; scalability to various stack sizes; and, safety and reliability. It was concluded that first tests with the voltage monitoring system not only confirmed the design, high throughput and signal quality, but also suggested another application, namely a stack impedance spectrometer for each individual cell. 1 ref., 3 figs.

Project W-420 Ventilation Stack Monitoring System Year 2000 Compliance Assessment Project Plan

International Nuclear Information System (INIS)

BUSSELL, J.H.

1999-01-01

This document contains a limited assessment of Year 2000 compliance for Project W-420. Additional information is provided as a road map to project documents and other references that may be used to verify Year 2000 compliance. This assessment describes the potential Year 2000 (Y2K) problems and describes the methods for achieving Y2K Compliance for Project W-420, Ventilation Stack Monitoring Systems Upgrades. The purpose of this assessment is to give an overview of the project. This document will not be updated and any dates contained in this document are estimates and may change. The project work scope includes upgrades to ventilation stacks and generic effluent monitoring systems (GEMS) at the 244-A Double Contained Receiver Tank (DCRT), the 244-BX DCRT, the 244-CR Vault, tanks 241-C-105 and 241-C-106, the 244-S DCRT, and the 244-TX DCRT. A detailed description of system dates, functions, interfaces, potential Y2K problems, and date resolutions can not be described since the project is in the definitive design phase, This assessment will describe the methods, protocols, and practices to ensure that equipment and systems do not have Y2K problems

Development of an Integrated Polymer Microfluidic Stack

International Nuclear Information System (INIS)

Datta, Proyag; Hammacher, Jens; Pease, Mark; Gurung, Sitanshu; Goettert, Jost

2006-01-01

Microfluidic is a field of considerable interest. While significant research has been carried out to develop microfluidic components, very little has been done to integrate the components into a complete working system. We present a flexible modular system platform that addresses the requirements of a complete microfluidic system. A microfluidic stack system is demonstrated with the layers of the stack being modular for specific functions. The stack and accompanying infrastructure provides an attractive platform for users to transition their design concepts into a working microfluidic system quickly with very little effort. The concept is demonstrated by using the system to carry out a chemilumiscence experiment. Details regarding the fabrication, assembly and experimental methods are presented

Optimization of hole generation in Ti/CFRP stacks

Science.gov (United States)

Ivanov, Y. N.; Pashkov, A. E.; Chashhin, N. S.

2018-03-01

The article aims to describe methods for improving the surface quality and hole accuracy in Ti/CFRP stacks by optimizing cutting methods and drill geometry. The research is based on the fundamentals of machine building, theory of probability, mathematical statistics, and experiment planning and manufacturing process optimization theories. Statistical processing of experiment data was carried out by means of Statistica 6 and Microsoft Excel 2010. Surface geometry in Ti stacks was analyzed using a Taylor Hobson Form Talysurf i200 Series Profilometer, and in CFRP stacks - using a Bruker ContourGT-Kl Optical Microscope. Hole shapes and sizes were analyzed using a Carl Zeiss CONTURA G2 Measuring machine, temperatures in cutting zones were recorded with a FLIR SC7000 Series Infrared Camera. Models of multivariate analysis of variance were developed. They show effects of drilling modes on surface quality and accuracy of holes in Ti/CFRP stacks. The task of multicriteria drilling process optimization was solved. Optimal cutting technologies which improve performance were developed. Methods for assessing thermal tool and material expansion effects on the accuracy of holes in Ti/CFRP/Ti stacks were developed.

Operation of a Five-Stage 40,000-CM2-Area Insulator Stack at 158 KV/CM

International Nuclear Information System (INIS)

Anderson RA; Clark, Robert E; Corcoran, PA; Douglas, John W; Gilliland, TL; Horry, ML; Hughes, Thomas P; Ives, HC; Long, FW; Martin, TH; McDaniel, DH; Milton, Osborne; Mostrom, Michael A; Seamen, JF; Shoup, RW; Smith, ID; Smith, JW; Spielman, RB; Struve, KW; Stygar, WA; Vogtlin, George E; Wagoner, TC; Yamamoto, Osamu

1999-01-01

We have demonstrated successful operation of a 3.35- m-diameter insulator stack at 158 kV/cm on five consecutive Z-accelerator shots. The stack consisted of five +45 deg;-profile 5.715-cm-thick cross-linked-polystyrene (Rexolite- 1422) insulator rings, and four anodized- aluminum grading rings shaped to reduce the field at cathode triple junctions. The width of the voltage pulse at 89% of peak was 32 ns. We compare this result to a new empirical flashover relation developed from previous small-insulator experiments conducted with flat unanodized electrodes. The relation predicts a 50% flashover probability for a Rexolite insulator during an applied voltage pulse when E max e -0.27/d (t eff C) 1/10 = 224, where E max is the peak mean electric field (kV/cm), d is the insulator thickness (cm), t eff is the effective pulse width (ps), and C is the insulator circumference (cm). We find the Z stack can be operated at a stress at least 19% higher than predicted. This result, and previous experiments conducted by Vogtlin, suggest anodized electrodes with geometries that reduce the field at both anode and cathode triple junctions would improve the flashover strength of +45 deg; insulators

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

Fabrication of high gradient insulators by stack compression

Science.gov (United States)

Harris, John Richardson; Sanders, Dave; Hawkins, Steven Anthony; Norona, Marcelo

2014-04-29

Individual layers of a high gradient insulator (HGI) are first pre-cut to their final dimensions. The pre-cut layers are then stacked to form an assembly that is subsequently pressed into an HGI unit with the desired dimension. The individual layers are stacked, and alignment is maintained, using a sacrificial alignment tube that is removed after the stack is hot pressed. The HGI's are used as high voltage vacuum insulators in energy storage and transmission structures or devices, e.g. in particle accelerators and pulsed power systems.

A dilute Cu(Ni) alloy for synthesis of large-area Bernal stacked bilayer graphene using atmospheric pressure chemical vapour deposition

Energy Technology Data Exchange (ETDEWEB)

Madito, M. J.; Bello, A.; Dangbegnon, J. K.; Momodu, D. Y.; Masikhwa, T. M.; Barzegar, F.; Manyala, N., E-mail: ncholu.manyala@up.ac.za [Department of Physics, Institute of Applied Materials, SARCHI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028 (South Africa); Oliphant, C. J.; Jordaan, W. A. [National Metrology Institute of South Africa, Private Bag X34, Lynwood Ridge, Pretoria 0040 (South Africa); Fabiane, M. [Department of Physics, Institute of Applied Materials, SARCHI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028 (South Africa); Department of Physics, National University of Lesotho, P.O. Roma 180 (Lesotho)

2016-01-07

A bilayer graphene film obtained on copper (Cu) foil is known to have a significant fraction of non-Bernal (AB) stacking and on copper/nickel (Cu/Ni) thin films is known to grow over a large-area with AB stacking. In this study, annealed Cu foils for graphene growth were doped with small concentrations of Ni to obtain dilute Cu(Ni) alloys in which the hydrocarbon decomposition rate of Cu will be enhanced by Ni during synthesis of large-area AB-stacked bilayer graphene using atmospheric pressure chemical vapour deposition. The Ni doped concentration and the Ni homogeneous distribution in Cu foil were confirmed with inductively coupled plasma optical emission spectrometry and proton-induced X-ray emission. An electron backscatter diffraction map showed that Cu foils have a single (001) surface orientation which leads to a uniform growth rate on Cu surface in early stages of graphene growth and also leads to a uniform Ni surface concentration distribution through segregation kinetics. The increase in Ni surface concentration in foils was investigated with time-of-flight secondary ion mass spectrometry. The quality of graphene, the number of graphene layers, and the layers stacking order in synthesized bilayer graphene films were confirmed by Raman and electron diffraction measurements. A four point probe station was used to measure the sheet resistance of graphene films. As compared to Cu foil, the prepared dilute Cu(Ni) alloy demonstrated the good capability of growing large-area AB-stacked bilayer graphene film by increasing Ni content in Cu surface layer.

Validation of a HT-PEMFC stack for CHP applications

Energy Technology Data Exchange (ETDEWEB)

Pasupathi, S.; Ulleberg, Oe. [Western Cape Univ. (South Africa). HySA Systems, SAIAMC; Bujlo, P. [Western Cape Univ. (South Africa). HySA Systems, SAIAMC; Electrotechnical Institute Wroclaw Division (Poland); Scholta, J. [Centre for Solar Energy and Hydrogen Research (ZSW) (Germany)

2010-07-01

Fuel cell systems are very attractive for stationary co-generation applications as they can produce heat and electricity efficiently in a decentralized and environmentally friendly manner. PEMFC stacks operating at temperatures above 120 C, specifically in the range of 140-180 C, are ideal for co-generation purposes. In this study, preliminary results from a HTPEMFC stack designed for CHP applications is presented and discussed. A short, five-cell, HT-PEMFC stack was assembled with Celtec- P-2100 MEAs and validated in terms of electrical performance. The stack was operated with hydrogen and air at 160 C and the utilization curves for anode and cathode were recorded for a wide range of gas utilization at a current density of 0.52 A/cm{sup 2}. The current voltage characteristic was measured at optimal utilization values at 160 C. A 1kW stack is assembled and is currently being validated for its performance under various operating conditions for use in CHP applications. (orig.)

Routes to a commercially viable PEM fuel cell stack

Energy Technology Data Exchange (ETDEWEB)

Newton, J.; Foster, S.E.; Hodgson, D.; Marrett, A.

2002-07-01

This report describes the results of a project to design and build a 10 kW{sub e} proton exchange membrane fuel cell (PEMFC) stack, including membrane electrode assemblies (MEAs), bipolar plates and stack hardware. The aim was to prove the design concept and to demonstrate functionality by operating the stack at >1 kW{sub e}/L and 500 W/kg for 200 hours operation. The project was extended to include the assembly and testing of two additional 1 kW{sub e} PEMFC stacks based on coated metal components. Low equivalent weight perfluorinated ionomer ion exchange membranes were prepared and were found to give a superior electrochemical performance to commercial materials. A technique to etch various stainless steel grades and control processes was successfully developed and optimised. Coatings for stainless steel and titanium were successfully developed and met the required performance criteria. All PEMFC stack components were selected and designed to enable subsequent commercial manufacture.

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.

Sport stacking activities in school children's motor skill development.

Science.gov (United States)

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

2011-10-01

This study examined the impact of a 12-wk. sport stacking intervention on reaction time (RT), manual dexterity, and hand-eye coordination in elementary school-aged children. 80 Grade 2 students participated in a 15-min. sport stacking practice session every school day for 12 wk., and were tested on psychomotor performance improvement. Tests for choice RT, manual dexterity, and photoelectric rotary pursuit tracking were conducted pre- and post-intervention for both experimental group (n = 36) and the controls (n = 44) who did no sport stacking. Students who had the intervention showed a greater improvement in two-choice RT. No other group difference was found. Such sport stacking activities may facilitate children's central processing and perceptual-motor integration.

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.

Detailed Electrochemical Characterisation of Large SOFC Stacks

DEFF Research Database (Denmark)

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

2012-01-01

application of advanced methods for detailed electrochemical characterisation during operation. An operating stack is subject to steep compositional gradients in the gaseous reactant streams, and significant temperature gradients across each cell and across the stack, which makes it a complex system...... Fuel Cell A/S was characterised in detail using electrochemical impedance spectroscopy. An investigation of the optimal geometrical placement of the current probes and voltage probes was carried out in order to minimise measurement errors caused by stray impedances. Unwanted stray impedances...... are particularly problematic at high frequencies. Stray impedances may be caused by mutual inductance and stray capacitance in the geometrical set-up and do not describe the fuel cell. Three different stack geometries were investigated by electrochemical impedance spectroscopy. Impedance measurements were carried...

The Stack-Size of Combinatorial Tries Revisited

Directory of Open Access Journals (Sweden)

Markus E. Nebel

2002-12-01

Full Text Available In the present paper we consider a generalized class of extended binary trees in which leaves are distinguished in order to represent the location of a key within a trie of the same structure. We prove an exact asymptotic equivalent to the average stack-size of trees with α internal nodes and β leaves corresponding to keys; we assume that all trees with the same parameters α and β have the same probability. The assumption of that uniform model is motivated for example by the usage of tries for the compression of blockcodes. Furthermore, we will prove asymptotics for the r-th moments of the stack-size and we will show that a normalized stack-size possesses a theta distribution in the limit.

Crystallite size effects in stacking faulted nickel hydroxide and its electrochemical behaviour

International Nuclear Information System (INIS)

Ramesh, T.N.

2009-01-01

β-Nickel hydroxide comprises a long range periodic arrangement of atoms with a stacking sequence of AC AC AC-having an ideal composition Ni(OH) 2 . Variation in the preparative conditions can lead to the changes in the stacking sequence (AC AC BA CB AC AC or AC AC AB AC AC). This type of variation in stacking sequence can result in the formation of stacking fault in nickel hydroxide. The stability of the stacking fault depends on the free energy content of the sample. Stacking faults in nickel hydroxide is essential for better electrochemical activity. Also there are reports correlating particle size to the better electrochemical activity. Here we present the effect of crystallite size on the stacking faulted nickel hydroxide samples. The electrochemical performance of stacking faulted nickel hydroxide with small crystallite size exchanges 0.8e/Ni, while the samples with larger crystallite size exchange 0.4e/Ni. Hence a right combination of crystallite size and stacking fault content has to be controlled for good electrochemical activity of nickel hydroxide

From obc seismic to porosity volume: A pre-stack analysis of a turbidite reservoir, deepwater Campos Basin, Brazil

Science.gov (United States)

Martins, Luiz M. R.

The Campos Basin is the best known and most productive of the Brazilian coastal basins. Turbidites are, by far, the main oil-bearing reservoirs. Using a four component (4-C) ocean-bottom-cable (OBC) seismic survey I set out to improve the reservoir characterization in a deep-water turbidite field in the Campos Basin. In order to achieve my goal, pre-stack angle gathers were derived and PP and PS inversion were performed. The inversion was used as an input to predict the petrophysical properties of the reservoir. Converting seismic reflection amplitudes into impedance profiles not only maximizes vertical resolution but also minimizes tuning effects. Mapping the porosity is extremely important in the development of a hydrocarbon reservoirs. Combining seismic attributes derived from the P-P data and porosity logs I use linear multi-regression and neural network geostatistical tools to predict porosity between the seismic attributes and porosity logs at the well locations. After predicting porosity in well locations, those relationships were applied to the seismic attributes to generate a 3-D porosity volume. The predicted porosity volume highlighted the best reservoir facies in the reservoir. The integration of elastic impedance, shear impedance and porosity improved the reservoir characterization.

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.

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...

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...

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)

Charge transfer in pi-stacked systems including DNA

International Nuclear Information System (INIS)

Siebbeles, L.D.A.

2003-01-01

Charge migration in DNA is a subject of intense current study motivated by long-range detection of DNA damage and the potential application of DNA as a molecular wire in nanoscale electronic devices. A key structural element, which makes DNA a medium for long-range charge transfer, is the array of stacked base pairs in the interior of the double helix. The overlapping pi-orbitals of the nucleobases provide a pathway for motion of charge carriers generated on the stack. This 'pi-pathway' resembles the columnarly stacked macrocyclic cores in discotic materials such as triphenylenes. The structure of these pi-stacked systems is highly disordered with dynamic fluctuations occurring on picosecond to nanosecond time scales. Theoretical calculations, concerning the effects of structural disorder and nucleobase sequence in DNA, on the dynamics of charge carriers are presented. Electronic couplings and localization energies of charge carriers were calculated using density functional theory (DFT). Results for columnarly stacked triphenylenes and DNA nucleobases are compared. The results are used to provide insight into the factors that control the mobility of charge carriers. Further, experimental results on the site-selective oxidation of guanine nucleobases in DNA (hot spots for DNA damage) are analyzed on basis of the theoretical results

Studi Implementasi Lean Six Sigma dengan Pendekatan Value Stream Mapping untuk Mereduksi Idle Time Material pada Gudang Pelat dan Profil

Directory of Open Access Journals (Sweden)

Wawan Widiatmoko

2013-03-01

Full Text Available Peningkatan volume kegiatan industri maritim di Indonesia menuntut industri perkapalan di daerah Surabaya untuk lebih meningkatkan pelayanan baik berupa bangunan baru maupun reparasi kapal. Berdasarkan hal tersebut galangan harus mampu mengelola proses produksi dengan baik sehingga menghasilkan keuntungan yang maksimum. Salah satunya adalah proses inventory dan transport of materials yang efektif. Tugas akhir bertujuan untuk mengetahui sistem inventori yang diterapkan oleh perusahaan yang dijadikan sampel serta idle time material pelat dan profil yang ada di gudang bahan baku dengan menggunakan metode lean six sigma dengan pendekatan value stream mapping. Dari hasil perhitungan menggunakan diperoleh nilai sigma perhitungan idle time sebesar 0.1976 sehingga perlu dilakukan upaya peningkatan nilai sigma pengadaan material itu sendiri. Berdasarkan hasil analisa penyebab adanya idle time dengan menggunakan RCA diperoleh beberapa faktor yaitu : rendahnya nilai sigma penggunaan material, tidak tercapainya target pengerjaan pada proses fabrikasi, proses pengadaan material yang tidak mempertimbangkan strategi proses pembangunan kapal. Dengan penerapan lean six sigma dengan pendekatan value stream mapping dihasilkan usulan perbaikan proses inventori di perusahaan antara lain : meningkatkan nilai sigma penggunaan material, melakukan strategi pembelian material sesuai strategi pembangunan kapal berdasarkan zona, memperbaiki kerjasama dengan supplier material pelat dan profil. Pembuatan future state mapping mendapatkan usulan perbaikan dengan pembuatan perencanaan pengadaan material dengan mempertimbangkan strategi pembangunan kapal berdasarkan zona pembangunannya. Diperoleh strategi pengadaan material yang dilakukan sebanyak 4 kali order.

Optoelectronic interconnects for 3D wafer stacks

Science.gov (United States)

Ludwig, David; Carson, John C.; Lome, Louis S.

1996-01-01

Wafer and chip stacking are envisioned as means of providing increased processing power within the small confines of a three-dimensional structure. Optoelectronic devices can play an important role in these dense 3-D processing electronic packages in two ways. In pure electronic processing, optoelectronics can provide a method for increasing the number of input/output communication channels within the layers of the 3-D chip stack. Non-free space communication links allow the density of highly parallel input/output ports to increase dramatically over typical edge bus connections. In hybrid processors, where electronics and optics play a role in defining the computational algorithm, free space communication links are typically utilized for, among other reasons, the increased network link complexity which can be achieved. Free space optical interconnections provide bandwidths and interconnection complexity unobtainable in pure electrical interconnections. Stacked 3-D architectures can provide the electronics real estate and structure to deal with the increased bandwidth and global information provided by free space optical communications. This paper will provide definitions and examples of 3-D stacked architectures in optoelectronics processors. The benefits and issues of these technologies will be discussed.

Reliability analysis and initial requirements for FC systems and stacks

Science.gov (United States)

Åström, K.; Fontell, E.; Virtanen, S.

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

Development and preliminary experimental study on micro-stacked insulator

International Nuclear Information System (INIS)

Ren Chengyan; Yuan Weiqun; Zhang Dongdong; Yan Ping; Wang Jue

2009-01-01

High gradient insulating technology is one of the key technologies in new type dielectric wall accelerator(DWA). High gradient insulator, namely micro-stacked insulator, was developed and preliminary experimental study was done. Based on the finite element and particle simulating method, surface electric field distribution and electron movement track of micro-stacked insulator were numerated, and then the optimized design proposal was put forward. Using high temperature laminated method, we developed micro-stacked insulator samples which uses exhaustive fluorinated ethylene propylene(FEP) as dielectric layer and stainless steel as metal layer. Preliminary experiment of vacuum surface flashover in nanosecond pulse voltage was done and micro-stacked insulator exhibited favorable vacuum surface flashover performance with flashover field strength of near 180 kV/cm. (authors)

Tropospheric Ozonesonde Profiles at Long-term U.S. Monitoring Sites: 1. A Climatology Based on Self-Organizing Maps

Science.gov (United States)

Stauffer, Ryan M.; Thompson, Anne M.; Young, George S.

2016-01-01

Sonde-based climatologies of tropospheric ozone (O3) are vital for developing satellite retrieval algorithms and evaluating chemical transport model output. Typical O3 climatologies average measurements by latitude or region, and season. A recent analysis using self-organizing maps (SOM) to cluster ozonesondes from two tropical sites found that clusters of O3 mixing ratio profiles are an excellent way to capture O3variability and link meteorological influences to O3 profiles. Clusters correspond to distinct meteorological conditions, e.g., convection, subsidence, cloud cover, and transported pollution. Here the SOM technique is extended to four long-term U.S. sites (Boulder, CO; Huntsville, AL; Trinidad Head, CA; and Wallops Island, VA) with4530 total profiles. Sensitivity tests on k-means algorithm and SOM justify use of 3 3 SOM (nine clusters). Ateach site, SOM clusters together O3 profiles with similar tropopause height, 500 hPa height temperature, and amount of tropospheric and total column O3. Cluster means are compared to monthly O3 climatologies.For all four sites, near-tropopause O3 is double (over +100 parts per billion by volume; ppbv) the monthly climatological O3 mixing ratio in three clusters that contain 1316 of profiles, mostly in winter and spring.Large midtropospheric deviations from monthly means (6 ppbv, +710 ppbv O3 at 6 km) are found in two of the most populated clusters (combined 3639 of profiles). These two clusters contain distinctly polluted(summer) and clean O3 (fall-winter, high tropopause) profiles, respectively. As for tropical profiles previously analyzed with SOM, O3 averages are often poor representations of U.S. O3 profile statistics.

Airborne gamma-ray spectrometer and magnetometer survey, Bend quadrangle (Oregon). Final report

International Nuclear Information System (INIS)

1981-01-01

Eight uranium anomalies meet the minimum statistical requirements as defined in Volume I. These anomalies are listed and are shown on the Uranium Anomaly Interpretation Map. Potassim (%K), equivalent Uranium (ppM eU), equivalent Thorium (ppM eT), eU/eT, eU/K, eT/K, and Magnetic Pseudo Contour Maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation in Volume II

PRECISION COSMOGRAPHY WITH STACKED VOIDS

International Nuclear Information System (INIS)

Lavaux, Guilhem; Wandelt, Benjamin D.

2012-01-01

We present a purely geometrical method for probing the expansion history of the universe from the observation of the shape of stacked voids in spectroscopic redshift surveys. Our method is an Alcock-Paczyński (AP) test based on the average sphericity of voids posited on the local isotropy of the universe. It works by comparing the temporal extent of cosmic voids along the line of sight with their angular, spatial extent. We describe the algorithm that we use to detect and stack voids in redshift shells on the light cone and test it on mock light cones produced from N-body simulations. We establish a robust statistical model for estimating the average stretching of voids in redshift space and quantify the contamination by peculiar velocities. Finally, assuming that the void statistics that we derive from N-body simulations is preserved when considering galaxy surveys, we assess the capability of this approach to constrain dark energy parameters. We report this assessment in terms of the figure of merit (FoM) of the dark energy task force and in particular of the proposed Euclid mission which is particularly suited for this technique since it is a spectroscopic survey. The FoM due to stacked voids from the Euclid wide survey may double that of all other dark energy probes derived from Euclid data alone (combined with Planck priors). In particular, voids seem to outperform baryon acoustic oscillations by an order of magnitude. This result is consistent with simple estimates based on mode counting. The AP test based on stacked voids may be a significant addition to the portfolio of major dark energy probes and its potentialities must be studied in detail.

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

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.

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.

Calculation of tritium release from reactor's stack

International Nuclear Information System (INIS)

Akhadi, M.

1996-01-01

Method for calculation of tritium release from nuclear to environment has been discussed. Part of gas effluent contain tritium in form of HTO vapor released from reactor's stack was sampled using silica-gel. The silica-gel was put in the water to withdraw HTO vapor absorbed by silica-gel. Tritium concentration in the water was measured by liquid scintillation counter of Aloka LSC-703. Tritium concentration in the gas effluent and total release of tritium from reactor's stack during certain interval time were calculated using simple mathematic formula. This method has examined for calculation of tritium release from JRR-3M's stack of JAERI, Japan. From the calculation it was obtained the value of tritium release as much as 4.63 x 10 11 Bq during one month. (author)

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.

Nonlinearly stacked low noise turbofan stator

Science.gov (United States)

Schuster, William B. (Inventor); Nolcheff, Nick A. (Inventor); Gunaraj, John A. (Inventor); Kontos, Karen B. (Inventor); Weir, Donald S. (Inventor)

2009-01-01

A nonlinearly stacked low noise turbofan stator vane having a characteristic curve that is characterized by a nonlinear sweep and a nonlinear lean is provided. The stator is in an axial fan or compressor turbomachinery stage that is comprised of a collection of vanes whose highly three-dimensional shape is selected to reduce rotor-stator and rotor-strut interaction noise while maintaining the aerodynamic and mechanical performance of the vane. The nonlinearly stacked low noise turbofan stator vane reduces noise associated with the fan stage of turbomachinery to improve environmental compatibility.

Characterization of polymer solar cells by TOF-SIMS depth profiling

NARCIS (Netherlands)

Bulle-Lieuwma, C.W.T.; Gennip, van W.J.H.; Duren, van J.K.J.; Jonkheijm, P.; Janssen, R.A.J.; Niemantsverdriet, J.W.

2003-01-01

Solar cells consisting of polymer layers sandwiched between a transparent electrode on glass and a metal top electrode are studied using dynamic time-of-flight secondary ion mass spectrometry (TOF-SIMS) in dual-beam mode. Because depth profiling of polymers and polymer-metal stacks is a relatively

Airborne gamma-ray spectrometer and magnetometer survey: Victoria quadrangle (Washington). Final report

International Nuclear Information System (INIS)

1981-01-01

One uranium anomaly meets the minimum statistical requirements. Potassium (%K), equivalent Uranium (ppM eU), equivalent Thorium (ppM eT), eU/eT, eU/K, eT/K, and magnetic pseudo-contour maps are presented. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation. Anomaly number 1 is over an exposure of the Permian Shuksan metamorphic suite which is predominantly phyllite

Comprehensive first-principles study of stable stacking faults in hcp metals

International Nuclear Information System (INIS)

Yin, Binglun; Wu, Zhaoxuan; Curtin, W.A.

2017-01-01

The plastic deformation in hcp metals is complex, with the associated dislocation core structures and properties not well understood on many slip planes in most hcp metals. A first step in establishing the dislocation properties is to examine the stable stacking fault energy and its structure on relevant slip planes. However, this has been perplexing in the hcp structure due to additional in-plane displacements on both sides of the slip plane. Here, density functional theory guided by crystal symmetry analysis is used to study all relevant stable stacking faults in 6 hcp metals (Mg, Ti, Zr, Re, Zn, Cd). Specially, the stable stacking fault energy, position, and structure on the Basal, Prism I and II, Pyramidal I and II planes are determined using all-periodic supercells with full atomic relaxation. All metals show similar stacking fault position and structure as dictated by crystal symmetry, but the associated stacking fault energy, being governed by the atomic bonding, differs significantly among them. Stacking faults on all the slip planes except the Basal plane show substantial out-of-plane displacements while stacking faults on the Prism II, Pyramidal I and II planes show additional in-plane displacements, all extending to multiple atom layers. The in-plane displacements are not captured in the standard computational approach for stacking faults, and significant differences are shown in the energies of such stacking faults between the standard approach and fully-relaxed case. The existence of well-defined stable stacking fault on the Pyramidal planes suggests zonal dislocations are unlikely. Calculations on the equilibrium partial separation further suggests 〈c + a〉 dissociation into three partials on the Pyramidal I plane is unlikely and 〈c〉 dissociation on Prism planes is unlikely to be stable against climb-dissociation onto the Basal planes in these metals.

Analysis of preemption costs for the stack cache

DEFF Research Database (Denmark)

Naji, Amine; Abbaspour, Sahar; Brandner, Florian

2018-01-01

, 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...

A stacking method and its applications to Lanzarote tide gauge records

Science.gov (United States)

Zhu, Ping; van Ruymbeke, Michel; Cadicheanu, Nicoleta

2009-12-01

A time-period analysis tool based on stacking is introduced in this paper. The original idea comes from the classical tidal analysis method. It is assumed that the period of each major tidal component is precisely determined based on the astronomical constants and it is unchangeable with time at a given point in the Earth. We sum the tidal records at a fixed tidal component center period T then take the mean of it. The stacking could significantly increase the signal-to-noise ratio (SNR) if a certain number of stacking circles is reached. The stacking results were fitted using a sinusoidal function, the amplitude and phase of the fitting curve is computed by the least squares methods. The advantage of the method is that: (1) an individual periodical signal could be isolated by stacking; (2) one can construct a linear Stacking-Spectrum (SSP) by changing the stacking period Ts; (3) the time-period distribution of the singularity component could be approximated by a Sliding-Stacking approach. The shortcoming of the method is that in order to isolate a low energy frequency or separate the nearby frequencies, we need a long enough series with high sampling rate. The method was tested with a numeric series and then it was applied to 1788 days Lanzarote tide gauge records as an example.

Multi-microscopy study of the influence of stacking faults and three-dimensional In distribution on the optical properties of m-plane InGaN quantum wells grown on microwire sidewalls

Energy Technology Data Exchange (ETDEWEB)

Mancini, L.; Lefebvre, W.; Houard, J.; Blum, I.; Vurpillot, F.; Rigutti, L., E-mail: lorenzo.rigutti@univ-rouen.fr [Groupe de Physique des Matériaux, UMR CNRS 6634, Normandie University, INSA and University of Rouen, 76800 St Etienne du Rouvray (France); Hernández-Maldonado, D. [Groupe de Physique des Matériaux, UMR CNRS 6634, Normandie University, INSA and University of Rouen, 76800 St Etienne du Rouvray (France); SuperSTEM STFC Daresbury Laboratories, Warrington WA4 4AD (United Kingdom); Eymery, J.; Durand, C. [CEA, CNRS, Université Grenoble Alpes, 38000 Grenoble (France); Tchernycheva, M. [Institut d' Electronique Fondamentale, UMR CNRS 8622, University Paris Saclay, 91405 Orsay (France)

2016-01-25

The optical properties of m-plane InGaN/GaN quantum wells grown on microwire sidewalls were investigated carrying out a correlative scanning transmission electron microscopy (STEM), atom probe tomography (APT), and micro-photoluminescence study applied on single nanoscale field-emission tips obtained by a focused ion beam annular milling. Instead of assuming simple rectangular composition profiles, yielding misleading predictions for the optical transition energies, we can thus take into account actual compositional distributions and the presence of stacking faults (SFs). SFs were shown to be responsible for a lowering of the recombination energies of the order of 0.1 eV with respect to those expected for defect-free quantum wells (QWs). Such energy reduction allows establishing a good correspondence between the transition energies observed by optical spectroscopy and those calculated on the basis of the QWs In measured composition and distribution assessed by STEM structural analysis and APT chemical mapping.

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.

Scanning SQUID microscopy of a ferromanganese crust from the northwestern Pacific: Submillimeter scale magnetostratigraphy as a new tool for age determination and mapping of environmental magnetic parameters

Science.gov (United States)

Noguchi, A.; Oda, H.; Yamamoto, Y.; Usui, A.; Sato, M.; Kawai, J.

2017-06-01

Ferromanganese crusts record long-term deep-sea environmental changes. Thus, providing their reliable high-resolution age models is important. We applied a magnetostratigraphic technique to estimate the growth rate of a ferromanganese crust using scanning SQUID (superconducting quantum interference device) microscope (SSM). SSM is designed to map the magnetic field across thin sections with submillimeter resolution. The crust sample was taken from the Takuyo-Daigo Seamount, northwestern Pacific, and recorded a limited supply of dust and sediment from continents. After drift correction and removal of spike noises, the magnetic field values were stacked within the areas of high signal-to-noise ratios. By correlating the obtained profiles with a standard geomagnetic polarity timescale, we obtained an average growth rate of 3.37 ± 0.06 mm/Ma, which is consistent with that obtained by 10Be/9Be geochronology (2.93 ± 0.15 mm/Ma). S ratio mapping shows low values after 3 Ma, associated with voids between columnar structures.

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.

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.

Ablation of film stacks in solar cell fabrication processes

Science.gov (United States)

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

2013-04-02

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

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.

Self-Patterning of Silica/Epoxy Nanocomposite Underfill by Tailored Hydrophilic-Superhydrophobic Surfaces for 3D Integrated Circuit (IC) Stacking.

Science.gov (United States)

Tuan, Chia-Chi; James, Nathan Pataki; Lin, Ziyin; Chen, Yun; Liu, Yan; Moon, Kyoung-Sik; Li, Zhuo; Wong, C P

2017-03-15

As microelectronics are trending toward smaller packages and integrated circuit (IC) stacks nowadays, underfill, the polymer composite filled in between the IC chip and the substrate, becomes increasingly important for interconnection reliability. However, traditional underfills cannot meet the requirements for low-profile and fine pitch in high density IC stacking packages. Post-applied underfills have difficulties in flowing into the small gaps between the chip and the substrate, while pre-applied underfills face filler entrapment at bond pads. In this report, we present a self-patterning underfilling technology that uses selective wetting of underfill on Cu bond pads and Si 3 N 4 passivation via surface energy engineering. This novel process, fully compatible with the conventional underfilling process, eliminates the issue of filler entrapment in typical pre-applied underfilling process, enabling high density and fine pitch IC die bonding.

Design and analysis of the PBFA-Z vacuum insulator stack

International Nuclear Information System (INIS)

Shoup, R.W.; Long, F.; Martin, T.H.; Stygar, W.A.; Spielman, R.B.; Struve, K.W.; Mostrom, M.; Corcoran, P.; Smith, I.

1996-01-01

Sandia is developing PBFA-Z, a 20-MA driver for z-pinch experiments by replacing the water lines, insulator stack, and MITLs on PBFA II with new hardware. The design of the vacuum insulator stack was dictated by the drive voltage, the electric field stress and grading requirements, the water line and MITL interface requirements, and the machine operations and maintenance requirements. The insulator stack will consist of four separate modules, each of a different design because of different voltage drive and hardware interface requirements. The shape of the components in each module, i.e., grading rings, insulator rings, flux excluders, anode and cathode conductors, and the design of the water line and MITL interfaces, were optimized by using the electrostatic analysis codes, ELECTRO and JASON. The time-dependent performance of the insulator stack was evaluated using IVORY, a 2-D PIC code. The insulator stack design and present the results of the ELECTRO and IVORY analyses are described. (author). 2 tabs., 9 figs., 3 refs

Design and analysis of the PBFA-Z vacuum insulator stack

Energy Technology Data Exchange (ETDEWEB)

Shoup, R W [Field Command Defense Nuclear Agency, Kirtland AFB, NM (United States); Long, F; Martin, T H; Stygar, W A; Spielman, R B [Sandia National Laboratories, Albuquerque, NM (United States). Dept 9573; Ives, H [EG and G, Albuquerque, NM (United States); Struve, K W; Mostrom, M [Mission Research Corp., Albuquerque, NM (United States); Corcoran, P; Smith, I [Pulse Sciences, Inc., San Leandro, CA (United States)

1997-12-31

Sandia is developing PBFA-Z, a 20-MA driver for z-pinch experiments by replacing the water lines, insulator stack, and MITLs on PBFA II with new hardware. The design of the vacuum insulator stack was dictated by the drive voltage, the electric field stress and grading requirements, the water line and MITL interface requirements, and the machine operations and maintenance requirements. The insulator stack will consist of four separate modules, each of a different design because of different voltage drive and hardware interface requirements. The shape of the components in each module, i.e., grading rings, insulator rings, flux excluders, anode and cathode conductors, and the design of the water line and MITL interfaces, were optimized by using the electrostatic analysis codes, ELECTRO and JASON. The time-dependent performance of the insulator stack was evaluated using IVORY, a 2-D PIC code. The insulator stack design and present the results of the ELECTRO and IVORY analyses are described. (author). 2 tabs., 9 figs., 3 refs.

Long Josephson Junction Stack Coupled to a Cavity

DEFF Research Database (Denmark)

Madsen, Søren Peder; Pedersen, Niels Falsig; Groenbech-Jensen, N.

2007-01-01

A stack of inductively coupled long Josephson junctions are modeled as a system of coupled sine-Gordon equations. One boundary of the stack is coupled electrically to a resonant cavity. With one fluxon in each Josephson junction, the inter-junction fluxon forces are repulsive. We look at a possible...... transition, induced by the cavity, to a bunched state....

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.

Mapping Soil Organic Matter with Hyperspectral Imaging

Science.gov (United States)

Moni, Christophe; Burud, Ingunn; Flø, Andreas; Rasse, Daniel

2014-05-01

Soil organic matter (SOM) plays a central role for both food security and the global environment. Soil organic matter is the 'glue' that binds soil particles together, leading to positive effects on soil water and nutrient availability for plant growth and helping to counteract the effects of erosion, runoff, compaction and crusting. Hyperspectral measurements of samples of soil profiles have been conducted with the aim of mapping soil organic matter on a macroscopic scale (millimeters and centimeters). Two soil profiles have been selected from the same experimental site, one from a plot amended with biochar and another one from a control plot, with the specific objective to quantify and map the distribution of biochar in the amended profile. The soil profiles were of size (30 x 10 x 10) cm3 and were scanned with two pushbroomtype hyperspectral cameras, one which is sensitive in the visible wavelength region (400 - 1000 nm) and one in the near infrared region (1000 - 2500 nm). The images from the two detectors were merged together into one full dataset covering the whole wavelength region. Layers of 15 mm were removed from the 10 cm high sample such that a total of 7 hyperspectral images were obtained from the samples. Each layer was analyzed with multivariate statistical techniques in order to map the different components in the soil profile. Moreover, a 3-dimensional visalization of the components through the depth of the sample was also obtained by combining the hyperspectral images from all the layers. Mid-infrared spectroscopy of selected samples of the measured soil profiles was conducted in order to correlate the chemical constituents with the hyperspectral results. The results show that hyperspectral imaging is a fast, non-destructive technique, well suited to characterize soil profiles on a macroscopic scale and hence to map elements and different organic matter quality present in a complete pedon. As such, we were able to map and quantify biochar in our

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

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.

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.

High power, repetitive stacked Blumlein pulse generators

Energy Technology Data Exchange (ETDEWEB)

Davanloo, F; Borovina, D L; Korioth, J L; Krause, R K; Collins, C B [Univ. of Texas at Dallas, Richardson, TX (United States). Center for Quantum Electronics; Agee, F J [US Air Force Phillips Lab., Kirtland AFB, NM (United States); Kingsley, L E [US Army CECOM, Ft. Monmouth, NJ (United States)

1997-12-31

The repetitive stacked Blumlein pulse power generators developed at the University of Texas at Dallas consist of several triaxial Blumleins stacked in series at one end. The lines are charged in parallel and synchronously commuted with a single switch at the other end. In this way, relatively low charging voltages are multiplied to give a high discharge voltage across an arbitrary load. Extensive characterization of these novel pulsers have been performed over the past few years. Results indicate that they are capable of producing high power waveforms with rise times and repetition rates in the range of 0.5-50 ns and 1-300 Hz, respectively, using a conventional thyratron, spark gap, or photoconductive switch. The progress in the development and use of stacked Blumlein pulse generators is reviewed. The technology and the characteristics of these novel pulsers driving flash x-ray diodes are discussed. (author). 4 figs., 5 refs.

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.

Simulations Of Transverse Stacking In The NSLS-II Booster

International Nuclear Information System (INIS)

Fliller, R. III; Shaftan, T.

2011-01-01

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

Simulation and Optimization of Air-Cooled PEMFC Stack for Lightweight Hybrid Vehicle Application

Directory of Open Access Journals (Sweden)

Jingming Liang

2015-01-01

Full Text Available A model of 2 kW air-cooled proton exchange membrane fuel cell (PEMFC stack has been built based upon the application of lightweight hybrid vehicle after analyzing the characteristics of heat transfer of the air-cooled stack. Different dissipating models of the air-cooled stack have been simulated and an optimal simulation model for air-cooled stack called convection heat transfer (CHT model has been figured out by applying the computational fluid dynamics (CFD software, based on which, the structure of the air-cooled stack has been optimized by adding irregular cooling fins at the end of the stack. According to the simulation result, the temperature of the stack has been equally distributed, reducing the cooling density and saving energy. Finally, the 2 kW hydrogen-air air-cooled PEMFC stack is manufactured and tested by comparing the simulation data which is to find out its operating regulations in order to further optimize its structure.

Project W-420 Stack Monitoring system upgrades conceptual design report

International Nuclear Information System (INIS)

TUCK, J.A.

1998-01-01

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

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.

Behavior of a nuclear power plant ventilation stack for wind loads

International Nuclear Information System (INIS)

Venkatachalapathy, V.

2012-01-01

This paper describes behavior of self supporting tall reinforced concrete (RC) ventilation stack of a nuclear power plant (NPP) for wind loads. Since the static and equivalent dynamic wind loads are inter-dependant on overall size of the stack, proper sizing of the stack geometry is important for reducing wind loads. The present study investigated the influence of engineered backfill soil on lateral response of ventilation stack. Ignoring backfill soil stiffness up to ground height does not allow to predict actual critical wind velocity causing across wind oscillation. The results show that proposed modification in the stack geometry modeled using 2D beam-spring elements is economical than that of single tapered geometry. Shaft diameter reduced in the proposed geometry indicates that there is a scope for overall space savings in the NPP layout. (author)

Planck 2015 results IX. Diffuse component separation: CMB maps

DEFF Research Database (Denmark)

Adam, R.; Ade, P. A R; Aghanim, N.

2016-01-01

We present foreground-reduced cosmic microwave background (CMB) maps derived from the full Planck data set in both temperature and polarization. Compared to the corresponding Planck 2013 temperature sky maps, the total data volume is larger by a factor of 3.2 for frequencies between 30 and 70 GHz......, and between 4.5 and 6.1μK averaged over pixels. The cosmological parameters derived from the analysis of temperature power spectra are in agreement at the 1σ level with the Planck 2015 likelihood. Unresolved mismatches between the noise properties of the data and simulations prevent a satisfactory description...... of the higher-order statistical properties of the polarization maps. Thus, the primary applications of these polarization maps are those that do not require massive simulations for accurate estimation of uncertainties, for instance estimation of cross-spectra and cross-correlations, or stacking analyses...

Reducing Communication Overhead by Scheduling TCP Transfers on Mobile Devices using Wireless Network Performance Maps

DEFF Research Database (Denmark)

Højgaard-Hansen, Kim; Madsen, Tatiana Kozlova; Schwefel, Hans-Peter

2012-01-01

The performance of wireless communication networks has been shown to have a strong location dependence. Measuring the performance while having accurate location information available makes it possible to generate performance maps. In this paper we propose a framework for the generation and use...... of such performance maps. We demonstrate how the framework can be used to reduce the retransmissions and to better utilise network resources when performing TCP-based file downloads in vehicular M2M communication scenarios. The approach works on top of a standard TCP stack hence has to map identified transmission...

Boiler briquette coal versus raw coal: Part I--Stack gas emissions.

Science.gov (United States)

Ge, S; Bai, Z; Liu, W; Zhu, T; Wang, T; Qing, S; Zhang, J

2001-04-01

Stack gas emissions were characterized for a steam-generating boiler commonly used in China. The boiler was tested when fired with a newly formulated boiler briquette coal (BB-coal) and when fired with conventional raw coal (R-coal). The stack gas emissions were analyzed to determine emission rates and emission factors and to develop chemical source profiles. A dilution source sampling system was used to collect PM on both Teflon membrane filters and quartz fiber filters. The Teflon filters were analyzed gravimetrically for PM10 and PM2.5 mass concentrations and by X-ray fluorescence (XRF) for trace elements. The quartz fiber filters were analyzed for organic carbon (OC) and elemental carbon (EC) using a thermal/optical reflectance technique. Sulfur dioxide was measured using the standard wet chemistry method. Carbon monoxide was measured using an Orsat combustion analyzer. The emission rates of the R-coal combustion (in kg/hr), determined using the measured stack gas concentrations and the stack gas emission rates, were 0.74 for PM10, 0.38 for PM2.5, 20.7 for SO2, and 6.8 for CO, while those of the BB-coal combustion were 0.95 for PM10, 0.30 for PM2.5, 7.5 for SO2, and 5.3 for CO. The fuel-mass-based emission factors (in g/kg) of the R-coal, determined using the emission rates and the fuel burn rates, were 1.68 for PM10, 0.87 for PM2.5, 46.7 for SO2, and 15 for CO, while those of the BB-coal were 2.51 for PM10, 0.79 for PM2.5, 19.9 for SO2, and 14 for CO. The task-based emission factors (in g/ton steam generated) of the R-coal, determined using the fuel-mass-based emission factors and the coal/steam conversion factors, were 0.23 for PM10, 0.12 for PM2.5, 6.4 for SO2, and 2.0 for CO, while those of the BB-coal were 0.30 for PM10, 0.094 for PM2.5, 2.4 for SO2, and 1.7 for CO. PM10 and PM2.5 elemental compositions are also presented for both types of coal tested in the study.

Boiler Briquette Coal versus Raw Coal: Part I-Stack Gas Emissions.

Science.gov (United States)

Ge, Su; Bai, Zhipeng; Liu, Weili; Zhu, Tan; Wang, Tongjian; Qing, Sheng; Zhang, Junfeng

2001-04-01

Stack gas emissions were characterized for a steam-generating boiler commonly used in China. The boiler was tested when fired with a newly formulated boiler briquette coal (BB-coal) and when fired with conventional raw coal (R-coal). The stack gas emissions were analyzed to determine emission rates and emission factors and to develop chemical source profiles. A dilution source sampling system was used to collect PM on both Teflon membrane filters and quartz fiber filters. The Teflon filters were analyzed gravimetrically for PM 10 and PM 2.5 mass concentrations and by X-ray fluorescence (XRF) for trace elements. The quartz fiber filters were analyzed for organic carbon (OC) and elemental carbon (EC) using a thermal/optical reflectance technique. Sulfur dioxide was measured using the standard wet chemistry method. Carbon monoxide was measured using an Orsat combustion analyzer. The emission rates of the R-coal combustion (in kg/hr), determined using the measured stack gas concentrations and the stack gas emission rates, were 0.74 for PM 10 , 0.38 for PM 25 , 20.7 for SO 2 , and 6.8 for CO, while those of the BB-coal combustion were 0.95 for PM 10 , 0.30 for PM 2 5 , 7.5 for SO 2 , and 5.3 for CO. The fuel-mass-based emission factors (in g/kg) of the R-coal, determined using the emission rates and the fuel burn rates, were 1.68 for PM 10 , 0.87 for PM 25 , 46.7 for SO 2 , and 15 for CO, while those of the BB-coal were 2.51 for PM 10 , 0.79 for PM 2.5 , 19.9 for SO 2 , and 14 for CO. The task-based emission factors (in g/ton steam generated) of the R-coal, determined using the fuel-mass-based emission factors and the coal/ steam conversion factors, were 0.23 for PM 10 , 0.12 for PM 2.5 , 6.4 for SO 2 , and 2.0 for CO, while those of the BB-coal were 0.30 for PM 10 , 0.094 for PM 2.5 , 2.4 for SO 2 , and 1.7 for CO. PM 10 and PM 2.5 elemental compositions are also presented for both types of coal tested in the study.

Inter-layered clay stacks in Jurassic shales

Science.gov (United States)

Pye, K.; Krinsley, D. H.

1983-01-01

Scanning electron microscopy in the backscattered electron mode is used together with energy-dispersive X-ray microanalysis to show that Lower Jurassic shales from the North Sea Basin contain large numbers of clay mineral stacks up to 150 microns in size. Polished shale sections are examined to determine the size, shape orientation, textural relationships, and internal compositional variations of the clays. Preliminary evidence that the clay stacks are authigenic, and may have formed at shallow burial depths during early diagenesis, is presented.

Numerical Study on the Cooling Characteristics of a Passive-Type PEMFC Stack

International Nuclear Information System (INIS)

Lee, Jae Hyuk; Kim, Bo Sung; Lee, Yong Taek; Kim, Yong Chan

2010-01-01

In a passive-type PEMFC stack, axial fans operate to supply both oxidant and coolant to cathode side of the stack. It is possible to make a simple system because the passive-type PEMFC stack does not require additional cooling equipment. However, the performance of a cooling system in which water is used as a coolant is better than that of the air-cooling system. To ensure system reliability, it is essential to make cooling system effective by adopting an optimal stack design. In this study, a numerical investigation has been carried out to identify an optimum cooling strategy. Various channel configurations were applied to the test section. The passive-type PEMFC was tested by varying airflow rate distribution at the cathode side and external heat transfer coefficient of the stack. The best cooling performance was achieved when a channel with thick ribs was used, and the overheating at the center of the stack was reduced when a case in which airflow was concentrated at the middle of the stack was used

GRIM-Filter: Fast seed location filtering in DNA read mapping using processing-in-memory technologies.

Science.gov (United States)

Kim, Jeremie S; Senol Cali, Damla; Xin, Hongyi; Lee, Donghyuk; Ghose, Saugata; Alser, Mohammed; Hassan, Hasan; Ergin, Oguz; Alkan, Can; Mutlu, Onur

2018-05-09

Seed location filtering is critical in DNA read mapping, a process where billions of DNA fragments (reads) sampled from a donor are mapped onto a reference genome to identify genomic variants of the donor. State-of-the-art read mappers 1) quickly generate possible mapping locations for seeds (i.e., smaller segments) within each read, 2) extract reference sequences at each of the mapping locations, and 3) check similarity between each read and its associated reference sequences with a computationally-expensive algorithm (i.e., sequence alignment) to determine the origin of the read. A seed location filter comes into play before alignment, discarding seed locations that alignment would deem a poor match. The ideal seed location filter would discard all poor match locations prior to alignment such that there is no wasted computation on unnecessary alignments. We propose a novel seed location filtering algorithm, GRIM-Filter, optimized to exploit 3D-stacked memory systems that integrate computation within a logic layer stacked under memory layers, to perform processing-in-memory (PIM). GRIM-Filter quickly filters seed locations by 1) introducing a new representation of coarse-grained segments of the reference genome, and 2) using massively-parallel in-memory operations to identify read presence within each coarse-grained segment. Our evaluations show that for a sequence alignment error tolerance of 0.05, GRIM-Filter 1) reduces the false negative rate of filtering by 5.59x-6.41x, and 2) provides an end-to-end read mapper speedup of 1.81x-3.65x, compared to a state-of-the-art read mapper employing the best previous seed location filtering algorithm. GRIM-Filter exploits 3D-stacked memory, which enables the efficient use of processing-in-memory, to overcome the memory bandwidth bottleneck in seed location filtering. We show that GRIM-Filter significantly improves the performance of a state-of-the-art read mapper. GRIM-Filter is a universal seed location filter that can be

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.

A dual shared stack for FSLM in Erika Enterprise

NARCIS (Netherlands)

Balasubramanian, S.M.N.; Afshar, S.; Gai, P.; Behnam, M.; Bril, R.J.

2017-01-01

Recently, the flexible spin-lock model (FSLM) has been introduced, unifying spin-based and suspension-based resource sharing protocols for real-time multi-core platforms. Unlike the multiprocessor stack resource policy (MSRP), FSLM doesn’t allow tasks on a core to share a single stack, however. In

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...

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

Revisit the carpet cloak from optical conformal mapping

OpenAIRE

Li, Hui; Xu, Yadong; Wu, Qiannan; Chen, Huanyang

2013-01-01

The original carpet cloak [Phys. Rev. Lett. 101, 203901 (2008)] was designed by a numerical method, the quasi-conformal mapping. Therefore its refractive index profile was obtained numerically. In this letter, we propose a new carpet cloak based on the optical conformal mapping, with an analytical form of a refractive index profile, thereby facilitating future experimental designs.

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.

40 CFR 63.307 - Standards for bypass/bleeder stacks.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Standards for bypass/bleeder stacks. 63.307 Section 63.307 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Standards for Coke Oven Batteries § 63.307 Standards for bypass/bleeder stacks. (a)(1) Except as otherwise...

Conservative Initial Mapping For Multidimensional Simulations of Stellar Explosions

International Nuclear Information System (INIS)

Chen, Ke-Jung; Heger, Alexander; Almgren, Ann

2012-01-01

Mapping one-dimensional stellar profiles onto multidimensional grids as initial conditions for hydrodynamics calculations can lead to numerical artifacts, one of the most severe of which is the violation of conservation laws for physical quantities such as energy and mass. Here we introduce a numerical scheme for mapping one-dimensional spherically-symmetric data onto multidimensional meshes so that these physical quantities are conserved. We validate our scheme by porting a realistic 1D Lagrangian stellar profile to the new multidimensional Eulerian hydro code CASTRO. Our results show that all important features in the profiles are reproduced on the new grid and that conservation laws are enforced at all resolutions after mapping.

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

Production and Reliability Oriented SOFC Cell and Stack Design

DEFF Research Database (Denmark)

Hauth, Martin; Lawlor, Vincent; Cartellieri, Peter

2017-01-01

The paper presents an innovative development methodology for a production and reliability oriented SOFC cell and stack design aiming at improving the stacks robustness, manufacturability, efficiency and cost. Multi-physics models allowed a probabilistic approach to consider statistical variations...... 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...... and output parameters and to perform a sensitivity analysis were developed and implemented. The capabilities of the methodology is illustrated on two practical cases....

Theory and experiment on electromagnetic-wave-propagation velocities in stacked superconducting tunnel structures

DEFF Research Database (Denmark)

Sakai, S.; Ustinov, A. V.; Kohlstedt, H.

1994-01-01

Characteristic velocities of the electromagnetic waves propagating in vertically stacked Josephson transmission are theoretically discussed. An equation for solving n velocities of the waves in an n Josephson-junction stack is derived. The solutions of two- and threefold stacks are especially...... focused on. Furthermore, under the assumption that all parameters of the layers are equal, analytic solutions for a generic N-fold stack are presented. The velocities of the waves in two- and three-junction stacks by Nb-Al-AlOx-Nb systems are experimentally obtained by measuring the cavity resonance...

Stack Parameters Effect on the Performance of Anharmonic Resonator Thermoacoustic Heat Engine

KAUST Repository

Nouh, Mostafa A.; Arafa, Nadim M.; Abdel-Rahman, Ehab

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.

ejIP: A TCP/IP Stack for Embedded Java

DEFF Research Database (Denmark)

Schoeberl, Martin

2011-01-01

present the design and implementation of a network stack written entirely in Java. This implementation serves as an example how to implement system functions in a safe language and gives evidence that Java can be used for operating system related functionality. The described TCP/IP stack ejIP has already...

Review of measurement techniques for stack monitoring of long-lived alpha emitters

International Nuclear Information System (INIS)

Kordas, J.F.; Phelps, P.L.

1978-01-01

As a result of the promulgation of new guidelines by the Environmental Protection Agency (40 CFR 190) for releases of long-lived, alpha-emitting substances, the stack-monitoring requirements for measuring long-lived alpha particles may change in terms of both monitored isotopes and the detection levels. This paper briefly reviews stack-monitoring requirements for long-lived alpha-emitting particles. It also examines the currently deployed alpha-particulate, stack-monitoring systems and discusses prototype systems that may be applicable to stack monitoring

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

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.

Numerical and experimental studies of stack shunt current for vanadium redox flow battery

International Nuclear Information System (INIS)

Yin, Cong; Guo, Shaoyun; Fang, Honglin; Liu, Jiayi; Li, Yang; Tang, Hao

2015-01-01

Highlights: • A coupled three-dimensional model of VRB cell stack is developed. • Shunt current of the stack is studied with the model and experiment. • Increased electrolyte resistance in channel and manifold lowers the shunt current. • Shunt current loss increases with stack cell number nonlinearly. - Abstract: The stack shunt current of VRB (vanadium redox flow battery) was investigated with experiments and 3D (three-dimensional) simulations. In the proposed model, cell voltages and electrolyte conductivities were calculated based on electrochemical reaction distributions and SOC (state of charge) values, respectively, while coulombic loss was estimated according to shunt current and vanadium ionic crossover through membrane. Shunt current distributions and coulombic efficiency are analyzed in terms of electrolyte conductivities and stack cell numbers. The distributions of cell voltages and shunt currents calculated with proposed model are validated with single cell and short stack tests. The model can be used to optimize VRB stack manifold and channel designs to improve VRB system efficiency

Estimates of the Lightning NOx Profile in the Vicinity of the North Alabama Lightning Mapping Array

Science.gov (United States)

Koshak, William J.; Peterson, Harold S.; McCaul, Eugene W.; Blazar, Arastoo

2010-01-01

The NASA Marshall Space Flight Center Lightning Nitrogen Oxides Model (LNOM) is applied to August 2006 North Alabama Lightning Mapping Array (NALMA) data to estimate the (unmixed and otherwise environmentally unmodified) vertical source profile of lightning nitrogen oxides, NOx = NO + NO2. Data from the National Lightning Detection Network (Trademark) (NLDN) is also employed. This is part of a larger effort aimed at building a more realistic lightning NOx emissions inventory for use by the U.S. Environmental Protection Agency (EPA) Community Multiscale Air Quality (CMAQ) modeling system. Overall, special attention is given to several important lightning variables including: the frequency and geographical distribution of lightning in the vicinity of the NALMA network, lightning type (ground or cloud flash), lightning channel length, channel altitude, channel peak current, and the number of strokes per flash. Laboratory spark chamber results from the literature are used to convert 1-meter channel segments (that are located at a particular known altitude; i.e., air density) to NOx concentration. The resulting lightning NOx source profiles are discussed.

Some important results from the air pollution distribution model STACKS (1988-1992)

International Nuclear Information System (INIS)

Erbrink, J.J.

1993-01-01

Attention is paid to the results of the study on the distribution of air pollutants by high chimney-stacks of electric power plants. An important product of the study is the integrated distribution model STACKS (Short Term Air-pollutant Concentrations Kema modelling System). The improvements and the extensions of STACKS are described in relation to the National Model, which has been used to estimate the environmental effects of individual chimney-stacks. The National Model shows unacceptable variations for high pollutant sources. Based on the results of STACKS revision of the National model has been taken into consideration. By means of the revised National Model a more realistic estimation of the environmental effects of electric power plants can be carried out

Stacking non-BPS D-branes

International Nuclear Information System (INIS)

Alberghi, Gian Luigi; Caceres, Elena; Goldstein, Kevin; Lowe, David A. . lowe@het.brown.edu

2001-08-01

We present a candidate supergravity solution for a stacked configuration of stable non-BPS D-branes in Type II string theory compactified on T 4 /Z 2 . This gives a supergravity description of nonabelian tachyon condensation on the brane woldvolume. (author)

New approach for dynamic flow management within the PEMFC stack

International Nuclear Information System (INIS)

Varlam, Mihai; Culcer, Mihai; Carcadea, Elena; Stefanescu, Ioan; Iliescu, Mariana; Enache, Adrian

2009-01-01

An adequate gas and water flow management is a key issue to reach and maintain a higher output power for a PEM fuel cell stack. One of the main aspects which could limit the performance of a PEM fuel cell stack is the weak capability for a non-uniform water distribution management within the fuel cell. The produced water could become a handicap to attain the best working performance by blocking the catalytic surfaces and by preventing the mass transport process. Usually, the excess water is removed in one cell, comparatively to others from the stack and taking into account that all the cells are supplied in parallel from a common air admission pipe, a limitation of gas flow rate within that cell is created. Consequently, this constraint will reduce further the water removal speed. This feedback process will generate finally a drastic decrease of the fuel cell stack performance. A new practical solution to this water and gas non-uniformity of distributions problem is to use a sequential purge procedure of several fuel cell groups inside the stack which could guarantee a right management of water. An experimental setup has been built based on four fuel cell stack. Every fuel cell was connected to a single removal pipe via a solenoid valve. A computer-controlled hardware and software system has been designed and built, in order to generate a given opening-closing sequence for the automatic valve system. (authors)

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)

Stacking dependence of carrier transport properties in multilayered black phosphorous

Science.gov (United States)

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

2016-02-01

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.

Extended Life PZT Stack Test Fixture

Science.gov (United States)

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

2009-01-01

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

Safety Evaluation of Radioactive Material Transport Package under Stacking Test Condition

International Nuclear Information System (INIS)

Lee, Ju Chan; Seo, Ki Seog; Yoo, Seong Yeon

2012-01-01

Radioactive waste transport package was developed to transport eight drums of low and intermediate level waste(LILW) in accordance with the IAEA and domestic related regulations. The package is classified with industrial package IP-2. IP-2 package is required to undergo a free drop test and a stacking test. After free drop and stacking tests, it should prevent the loss or dispersal of radioactive contents, and loss of shielding integrity which would result in more than 20 % increase in the radiation level at any external surface of the package. The objective of this study is to establish the safety test method and procedure for stacking test and to prove the structural integrities of the IP-2 package. Stacking test and analysis were performed with a compressive load equal to five times the weight of the package for a period of 24 hours using a full scale model. Strains and displacements were measured at the corner fitting of the package during the stacking test. The measured strains and displacements were compared with the analysis results, and there were good agreements. It is very difficult to measure the deflection at the container base, so the maximum deflection of the container base was calculated by the analysis method. The maximum displacement at the corner fitting and deflection at the container base were less than their allowable values. Dimensions of the test model, thickness of shielding material and bolt torque were measured before and after the stacking test. Throughout the stacking test, it was found that there were no loss or dispersal of radioactive contents and no loss of shielding integrity. Thus, the package was shown to comply with the requirements to maintain structural integrity under the stacking condition.

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.

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...... allowing for overcritical current densities to be considered. The method presented here allowed for a computational speedup factor of up to 2 orders of magnitude when compared to full 2-D simulations taking into account the actual structure of the stacks without compromising accuracy....

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.

Evidence of a non-dimensional parameter controlling the flooding of PEMFC stack

Energy Technology Data Exchange (ETDEWEB)

Buaud, Fabrice; Lelandais, Damien [Heat and Energy Department, Polytech' Nantes, Nantes University, Rue Christian Pauc, BP50609, 44 306 Nantes Cedex 3 (France); Auvity, Bruno [Heat and Energy Department, Polytech' Nantes, Nantes University, Rue Christian Pauc, BP50609, 44 306 Nantes Cedex 3 (France); Laboratoire de Thermocinetique de Nantes (CNRS-UMR 6607) (France)

2008-06-15

Water management is a key issue to get satisfactory and stable Polymer exchange membrane fuel cell (PEMFC) performances. The work reported in the present paper focuses on the determination of the operational conditions when using PEMFC stack working with ambient air without extra humidification. The objectives are to reduce as much as possible the auxiliaries consumptions. As far as the reaction air blower is concerned, the specific goal of the present tests is to find the minimum air flow rate to feed the PEMFC stack in order to prevent flooding. Our particular interest concerns the control of a PEMFC stack to power a prototype vehicle for the Shell Eco Marathon race. Tests are then conducted on a wide range of stoichiometry, for different values of current and stack temperature using ambient air. Flooding is shown to depend on all these parameters. A water balance calculation is developed comparing the amount of water produced by the electrochemical reaction to the amount of water transported as vapour in the exit air flow minus the amount of water incoming the stack in the ambient air. A non-dimensional number called the Flooding Number is constructed. This balance is first considered in the ideal case with the theoretical flow rate of reactants and products. It is shown that the stack temperature and the stoichiometry are the main order parameters and that conditions of ambient air have only secondary effects on the water balance. In a second step, the Flooding Number is evaluated for all the experimental tests. A critical Flooding Number appears clearly delimiting the range of operational conditions for which stack flooding appears. This result allows us to control the air blower and the cooling fan during the runs at the Shell Eco Marathon 2007 race in order to reduce hydrogen consumption due to auxiliaries. The non-dimensional number exhibited in the present paper is believed to be relevant to stack flooding. It can be used for any PEMFC stack to make clear

Multi-Stacked Supported Lipid Bilayer Micropatterning through Polymer Stencil Lift-Off

Directory of Open Access Journals (Sweden)

Yujie Zhu

2015-08-01

Full Text Available Complex multi-lamellar structures play a critical role in biological systems, where they are present as lamellar bodies, and as part of biological assemblies that control energy transduction processes. Multi-lamellar lipid layers not only provide interesting systems for fundamental research on membrane structure and bilayer-associated polypeptides, but can also serve as components in bioinspired materials or devices. Although the ability to pattern stacked lipid bilayers at the micron scale is of importance for these purposes, limited work has been done in developing such patterning techniques. Here, we present a simple and direct approach to pattern stacked supported lipid bilayers (SLBs using polymer stencil lift-off and the electrostatic interactions between cationic and anionic lipids. Both homogeneous and phase-segregated stacked SLB patterns were produced, demonstrating that the stacked lipid bilayers retain lateral diffusivity. We demonstrate patterned SLB stacks of up to four bilayers, where fluorescence resonance energy transfer (FRET and quenching was used to probe the interactions between lipid bilayers. Furthermore, the study of lipid phase behaviour showed that gel phase domains align between adjacent layers. The proposed stacked SLB pattern platform provides a robust model for studying lipid behaviour with a controlled number of bilayers, and an attractive means towards building functional bioinspired materials or devices.

The shape of velocity dispersion profiles and the dynamical state of galaxy clusters

Science.gov (United States)

Costa, A. P.; Ribeiro, A. L. B.; de Carvalho, R. R.

2018-01-01

Motivated by the existence of the relationship between the dynamical state of clusters and the shape of the velocity dispersion profiles (VDPs), we study the VDPs for Gaussian (G) and non-Gaussian (NG) systems for a subsample of clusters from the Yang catalogue. The groups cover a redshift interval of 0.03 ≤ z ≤ 0.1 with halo mass ≥1014 M⊙. We use a robust statistical method, Hellinger Distance, to classify the dynamical state of the systems according to their velocity distribution. The stacked VDP of each class, G and NG, is then determined using either Bright or Faint galaxies. The stacked VDP for G groups displays a central peak followed by a monotonically decreasing trend which indicates a predominance of radial orbits, with the Bright stacked VDP showing lower velocity dispersions in all radii. The distinct features we find in NG systems are manifested not only by the characteristic shape of VDP, with a depression in the central region, but also by a possible higher infall rate associated with galaxies in the Faint stacked VDP.

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

Science.gov (United States)

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

2003-01-01

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

Modelling baryonic effects on galaxy cluster mass profiles

Science.gov (United States)

Shirasaki, Masato; Lau, Erwin T.; Nagai, Daisuke

2018-06-01

Gravitational lensing is a powerful probe of the mass distribution of galaxy clusters and cosmology. However, accurate measurements of the cluster mass profiles are limited by uncertainties in cluster astrophysics. In this work, we present a physically motivated model of baryonic effects on the cluster mass profiles, which self-consistently takes into account the impact of baryons on the concentration as well as mass accretion histories of galaxy clusters. We calibrate this model using the Omega500 hydrodynamical cosmological simulations of galaxy clusters with varying baryonic physics. Our model will enable us to simultaneously constrain cluster mass, concentration, and cosmological parameters using stacked weak lensing measurements from upcoming optical cluster surveys.

Modelling Baryonic Effects on Galaxy Cluster Mass Profiles

Science.gov (United States)

Shirasaki, Masato; Lau, Erwin T.; Nagai, Daisuke

2018-03-01

Gravitational lensing is a powerful probe of the mass distribution of galaxy clusters and cosmology. However, accurate measurements of the cluster mass profiles are limited by uncertainties in cluster astrophysics. In this work, we present a physically motivated model of baryonic effects on the cluster mass profiles, which self-consistently takes into account the impact of baryons on the concentration as well as mass accretion histories of galaxy clusters. We calibrate this model using the Omega500 hydrodynamical cosmological simulations of galaxy clusters with varying baryonic physics. Our model will enable us to simultaneously constrain cluster mass, concentration, and cosmological parameters using stacked weak lensing measurements from upcoming optical cluster surveys.

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.

Rozšíření modulů OpenStack pro platformu Ansible

OpenAIRE

Šamalík, Adam

2016-01-01

OpenStack je cloudová platforma s distribuovanou architekturou, jejíž instalace je velice komplexní. V této práci navrhnu Ansible Playbook (automatický instalační skript), který OpenStack nainstaluje. OpenStack is a cloud platform with distributed architecture that is very complex to deploy. In this thesis, I will design an Ansible playbok (automatic deployment script) to deploy a custom OpenStack architecture. C

Statistics of Stacked Strata on Experimental Shelf Margins

Science.gov (United States)

Fernandes, A. M.; Straub, K. M.

2015-12-01

Continental margin deposits provide the most complete record on Earth of paleo-landscapes, but these records are complex and difficult to interpret. To a seismic geomorphologist or stratigrapher, mapped surfaces often present a static diachronous record of these landscapes through time. We present data that capture the dynamics of experimental shelf-margin landscapes at high-temporal resolution and define internal hierarchies within stacked channelized and weakly channelized deposits from the shelf to the slope. Motivated by observations from acoustically-imaged continental margins offshore Brunei and in the Gulf of Mexico, we use physical experiments to quantify stratal patterns of sub-aqueous slope channels and lobes that are linked to delta-top channels. The data presented here are from an experiment that was run for 26 hours of experimental run time. Overhead photographs and topographic scans captured flow dynamics and surface aggradation/degradation every ten minutes. Currents rich in sediment built a delta that prograded to the shelf-edge. These currents were designed to plunge at the shoreline and travel as turbidity currents beyond the delta and onto the continental slope. Pseudo-subsidence was imposed by a slight base-level rise that generated accommodation space and promoted the construction of stratigraphy on the delta-top. Compensational stacking is a term that is frequently applied to deposits that tend to fill in topographic lows in channelized and weakly channelized systems. The compensation index, a metric used to quantify the strength of compensation, is used here to characterize deposits at different temporal scales on the experimental landscape. The compensation timescale is the characteristic time at which the accumulated deposits begins to match the shape of basin-wide subsidence rates (uniform for these experiments). We will use the compensation indices along strike transects across the delta, proximal slope and distal slope to evaluate the

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.

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.

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.

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.

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.

Spectral-spatial classification of hyperspectral data with mutual information based segmented stacked autoencoder approach

Science.gov (United States)

Paul, Subir; Nagesh Kumar, D.

2018-04-01

Hyperspectral (HS) data comprises of continuous spectral responses of hundreds of narrow spectral bands with very fine spectral resolution or bandwidth, which offer feature identification and classification with high accuracy. In the present study, Mutual Information (MI) based Segmented Stacked Autoencoder (S-SAE) approach for spectral-spatial classification of the HS data is proposed to reduce the complexity and computational time compared to Stacked Autoencoder (SAE) based feature extraction. A non-parametric dependency measure (MI) based spectral segmentation is proposed instead of linear and parametric dependency measure to take care of both linear and nonlinear inter-band dependency for spectral segmentation of the HS bands. Then morphological profiles are created corresponding to segmented spectral features to assimilate the spatial information in the spectral-spatial classification approach. Two non-parametric classifiers, Support Vector Machine (SVM) with Gaussian kernel and Random Forest (RF) are used for classification of the three most popularly used HS datasets. Results of the numerical experiments carried out in this study have shown that SVM with a Gaussian kernel is providing better results for the Pavia University and Botswana datasets whereas RF is performing better for Indian Pines dataset. The experiments performed with the proposed methodology provide encouraging results compared to numerous existing approaches.

Development of a Three Dimensional Neural Sensing Device by a Stacking Method

Directory of Open Access Journals (Sweden)

Chih-Wei Chang

2010-04-01

Full Text Available This study reports a new stacking method for assembling a 3-D microprobe array. To date, 3-D array structures have usually been assembled with vertical spacers, snap fasteners and a supporting platform. Such methods have achieved 3-D structures but suffer from complex assembly steps, vertical interconnection for 3-D signal transmission, low structure strength and large implantable opening. By applying the proposed stacking method, the previous techniques could be replaced by 2-D wire bonding. In this way, supporting platforms with slots and vertical spacers were no longer needed. Furthermore, ASIC chips can be substituted for the spacers in the stacked arrays to achieve system integration, design flexibility and volume usage efficiency. To avoid overflow of the adhesive fluid during assembly, an anti-overflow design which made use of capillary action force was applied in the stacking method as well. Moreover, presented stacking procedure consumes only 35 minutes in average for a 4 × 4 3-D microprobe array without requiring other specially made assembly tools. To summarize, the advantages of the proposed stacking method for 3-D array assembly include simplified assembly process, high structure strength, smaller opening area and integration ability with active circuits. This stacking assembly technique allows an alternative method to create 3-D structures from planar components.

Three dimensional analysis of planar solid oxide fuel cell stack considering radiation

Energy Technology Data Exchange (ETDEWEB)

Tanaka, T.; Inui, Y.; Urata, A.; Kanno, T. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan)

2007-05-15

The authors have been engaged in numerical simulations of the planar type solid oxide fuel cell (SOFC) to make clear the dependence of the cell performance on its operating conditions. Up to now, the authors have already developed the simulation codes for the one channel region and the single cell plate in its cell stack. To calculate accurately the effect of radiation heat transfer from the cell stack surfaces, however, a code that can treat the whole cell stack is necessary. In the present study, therefore, the authors newly develop a three dimensional simulation code of the planar SOFC stack, and the detailed effect of the radiation heat transfer is investigated. It is made clear that the conventional codes are sufficiently accurate, and the newly developed whole cell stack code is not inevitable to predict the maximum cell temperature. This is because the thermal conductivity of the cell materials made of ceramics is very small, and the central part of the cell stack is almost free from the influence of radiation heat transfer. On the other hand, the stack simulation is needed to calculate accurately the cell voltage because the radiation heat transfer reduces it when the ambient temperature is low. The bad influence of low ambient temperature on the voltage is, however, small and relatively high voltage is obtained even when the ambient temperature is very low. (author)

Frequency domain method for the stack of seismic and radar data

Energy Technology Data Exchange (ETDEWEB)

Zhou, H; Sato, M [Tohoku University, Sendai (Japan); Xu, S

1997-10-22

With relation to the stacking method of elastic wave and radar wave, the frequency domain stacking method using the Fourier conversion was proposed as a method for automatically removing errors in time correction leaving advantages of the conventional horizontal stacking method. Concerning an example of wave motion with the same wave form and time difference, as a result of the analysis conducted by this method, it was found that not only effects are kept of suppressing random noise and regular noise in the conventional horizontal stacking method, but the resolution in the original wave motion data is kept. In the example, amplitude of the noise was a half of the wave motion signal, but if it is more than 0.85 times of the wave motion signal, favorable result cannot be obtained in this method. In the analysis in the area where time correction is very difficult and the correction cannot be made completely, it is useful also for the time domain stacking method to acquire data on high resolution of elastic wave and radar wave. 4 refs., 2 figs.

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...

Dual stacked partial least squares for analysis of near-infrared spectra

Energy Technology Data Exchange (ETDEWEB)

Bi, Yiming [Institute of Automation, Chinese Academy of Sciences, 100190 Beijing (China); Xie, Qiong, E-mail: yimbi@163.com [Institute of Automation, Chinese Academy of Sciences, 100190 Beijing (China); Peng, Silong; Tang, Liang; Hu, Yong; Tan, Jie [Institute of Automation, Chinese Academy of Sciences, 100190 Beijing (China); Zhao, Yuhui [School of Economics and Business, Northeastern University at Qinhuangdao, 066000 Qinhuangdao City (China); Li, Changwen [Food Research Institute of Tianjin Tasly Group, 300410 Tianjin (China)

2013-08-20

Graphical abstract: -- Highlights: •Dual stacking steps are used for multivariate calibration of near-infrared spectra. •A selective weighting strategy is introduced that only a subset of all available sub-models is used for model fusion. •Using two public near-infrared datasets, the proposed method achieved competitive results. •The method can be widely applied in many fields, such as Mid-infrared spectra data and Raman spectra data. -- Abstract: A new ensemble learning algorithm is presented for quantitative analysis of near-infrared spectra. The algorithm contains two steps of stacked regression and Partial Least Squares (PLS), termed Dual Stacked Partial Least Squares (DSPLS) algorithm. First, several sub-models were generated from the whole calibration set. The inner-stack step was implemented on sub-intervals of the spectrum. Then the outer-stack step was used to combine these sub-models. Several combination rules of the outer-stack step were analyzed for the proposed DSPLS algorithm. In addition, a novel selective weighting rule was also involved to select a subset of all available sub-models. Experiments on two public near-infrared datasets demonstrate that the proposed DSPLS with selective weighting rule provided superior prediction performance and outperformed the conventional PLS algorithm. Compared with the single model, the new ensemble model can provide more robust prediction result and can be considered an alternative choice for quantitative analytical applications.

Dual stacked partial least squares for analysis of near-infrared spectra

International Nuclear Information System (INIS)

Bi, Yiming; Xie, Qiong; Peng, Silong; Tang, Liang; Hu, Yong; Tan, Jie; Zhao, Yuhui; Li, Changwen

2013-01-01

Graphical abstract: -- Highlights: •Dual stacking steps are used for multivariate calibration of near-infrared spectra. •A selective weighting strategy is introduced that only a subset of all available sub-models is used for model fusion. •Using two public near-infrared datasets, the proposed method achieved competitive results. •The method can be widely applied in many fields, such as Mid-infrared spectra data and Raman spectra data. -- Abstract: A new ensemble learning algorithm is presented for quantitative analysis of near-infrared spectra. The algorithm contains two steps of stacked regression and Partial Least Squares (PLS), termed Dual Stacked Partial Least Squares (DSPLS) algorithm. First, several sub-models were generated from the whole calibration set. The inner-stack step was implemented on sub-intervals of the spectrum. Then the outer-stack step was used to combine these sub-models. Several combination rules of the outer-stack step were analyzed for the proposed DSPLS algorithm. In addition, a novel selective weighting rule was also involved to select a subset of all available sub-models. Experiments on two public near-infrared datasets demonstrate that the proposed DSPLS with selective weighting rule provided superior prediction performance and outperformed the conventional PLS algorithm. Compared with the single model, the new ensemble model can provide more robust prediction result and can be considered an alternative choice for quantitative analytical applications

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.

Reexamination of the ISABELLE box car stacking scheme

International Nuclear Information System (INIS)

Chasman, R.

1975-01-01

Box car stacking of ISABELLE after acceleration of the fundamental frequency in the AGS is reviewed with the present ISABELLE parameters and examined with regard to longitudinal impedence requirements. The scheme results in an impedance tolerance of Z/n less than or equal to 30 Ω compared to Z/n less than or equal to 5 Ω obtained for rf stacking. However, to meet the claimed luminosity, the AGS performance demands are increased above those assumed in the ISABELLE proposal

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)

Die-stacking architecture

CERN Document Server

Xie, Yuan

2015-01-01

The emerging three-dimensional (3D) chip architectures, with their intrinsic capability of reducing the wire length, promise attractive solutions to reduce the delay of interconnects in future microprocessors. 3D memory stacking enables much higher memory bandwidth for future chip-multiprocessor design, mitigating the ""memory wall"" problem. In addition, heterogenous integration enabled by 3D technology can also result in innovative designs for future microprocessors. This book first provides a brief introduction to this emerging technology, and then presents a variety of approaches to design

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

Reliability prediction of large fuel cell stack based on structure stress analysis

Science.gov (United States)

Liu, L. F.; Liu, B.; Wu, C. W.

2017-09-01

The aim of this paper is to improve the reliability of Proton Electrolyte Membrane Fuel Cell (PEMFC) stack by designing the clamping force and the thickness difference between the membrane electrode assembly (MEA) and the gasket. The stack reliability is directly determined by the component reliability, which is affected by the material property and contact stress. The component contact stress is a random variable because it is usually affected by many uncertain factors in the production and clamping process. We have investigated the influences of parameter variation coefficient on the probability distribution of contact stress using the equivalent stiffness model and the first-order second moment method. The optimal contact stress to make the component stay in the highest level reliability is obtained by the stress-strength interference model. To obtain the optimal contact stress between the contact components, the optimal thickness of the component and the stack clamping force are optimally designed. Finally, a detailed description is given how to design the MEA and gasket dimensions to obtain the highest stack reliability. This work can provide a valuable guidance in the design of stack structure for a high reliability of fuel cell stack.

40 CFR 63.7296 - What emission limitations must I meet for battery stacks?

Science.gov (United States)

2010-07-01

... for battery stacks? 63.7296 Section 63.7296 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY..., Quenching, and Battery Stacks Emission Limitations and Work Practice Standards § 63.7296 What emission limitations must I meet for battery stacks? You must not discharge to the atmosphere any emissions from any...

Using Self-Organizing Map (SOM) Clusters of Ozonesonde Profiles to Evaluate Climatologies and Create Linkages between Meteorology and Pollution

Science.gov (United States)

Stauffer, R. M.; Thompson, A. M.; Young, G. S.; Oltmans, S. J.; Johnson, B.

2016-12-01

Ozone (O3) climatologies are typically created by averaging ozonesonde profiles on a monthly or seasonal basis, either for specific regions or zonally. We demonstrate the advantages of using a statistical clustering technique, self-organizing maps (SOM), over this simple averaging, through analysis of more than 4500 sonde profiles taken from the long-term US sites at Boulder, CO; Huntsville, AL; Trinidad Head, CA; and Wallops Island, VA. First, we apply SOM to O3 mixing ratios from surface to 12 km amsl. At all four sites, profiles in SOM clusters exhibit similar tropopause height, 500 hPa height and temperature, and total and tropospheric column O3. Second, when profiles from each SOM cluster are compared to monthly O3 means, near-tropopause O3 in three of the clusters is double (over +100 ppbv) the climatological O3 mixing ratio. The three clusters include 13-16% of all profiles, mostly from winter and spring. Large mid-tropospheric deviations from monthly means are found in two highly-populated clusters that represent either distinctly polluted (summer) or clean O3 (fall-winter, high tropopause) profiles. Thus, SOM indeed appear to represent US O3 profile statistics better than conventional climatologies. In the case of Trinidad Head, SOM clusters of O3 profile data from the lower troposphere (surface-6 km amsl) can discriminate background vs polluted O3 and the meteorology associated with each. Two of nine O3 clusters exhibit thin layers ( 100s of m thick) of high O3, typically between 1 and 4 km. Comparisons between clusters and downwind, high-altitude surface O3 measurements display a marked impact of the elevated tropospheric O­­3. Days corresponding to the high O3 clusters exhibit hourly surface O3 anomalies at surface sites of +5 -10 ppbv compared to a climatology; the anomalies can last up to four days. We also explore applications of SOM to tropical ozonesonde profiles, where tropospheric O3 variability is generally smaller.

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

Fuel flow distribution in SOFC stacks revealed by impedance spectroscopy

DEFF Research Database (Denmark)

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

2014-01-01

As SOFC technology is moving closer to a commercial break through, methods to measure the “state-of-health” of operating stacks are becoming of increasing interest. This requires application of advanced methods for detailed electrical and electrochemical characterization during operation. An oper......As SOFC technology is moving closer to a commercial break through, methods to measure the “state-of-health” of operating stacks are becoming of increasing interest. This requires application of advanced methods for detailed electrical and electrochemical characterization during operation...... utilizations. The fuel flow distribution provides important information about the operating limits of the stack when high electrical efficiency is required....

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.

Stack Monitoring System At PUSPATI TRIGA Reactor

International Nuclear Information System (INIS)

Zamrul Faizad Omar; Mohd Sabri Minhat; Zareen Khan Abdul Jalil Khan; Ridzuan Abdul Mutalib; Khairulezwan Abdul Manan; Nurfarhana Ayuni Joha; Izhar Abu Hussin

2014-01-01

This paper describes the current Stack Monitoring System at PUSPATI TRIGA Reactor (RTP) building. A stack monitoring system is a continuous air monitor placed at the reactor top for monitoring the presence of radioactive gaseous in the effluent air from the RTP building. The system consists of four detectors that provide the reading for background, particulate, Iodine and Noble gas. There is a plan to replace the current system due to frequent fault of the system, thus thorough understanding of the current system is required. Overview of the whole system will be explained in this paper. Some current results would be displayed and moving forward brief plan would be mentioned. (author)

Frictional forces in an SOFC stack with sliding seals

Energy Technology Data Exchange (ETDEWEB)

Yamazaki, T; Oishi, N; Namikawa, T; Yamazaki, Y [Tokyo Institute of Technology, Tokyo (Japan)

1996-06-05

The detrimental thermal stresses in planar SOFC stacks can be reduced using sliding seals. In the proposal planar stack the electrolyte film is sandwiched by YSZ support rings to release the thermal stresses. In order to estimate the strength of the support ring, the frictional forces between heat resistant alloy and YSZ were measured at 900{degree}C. The coefficient of friction between Hastelloy X and YSZ increased when they were measured lifter 144h heating. However, the coefficient of friction between HA-214 and YSZ did not increase. The measurement and a calculation of the stresses in the support rings led the result that a thickness of 0.6mm was necessary for 200mm diameter support rings under a stack pressure of 0.1kgcm{sup -2}. 6 refs., 9 figs., 1 tab.

Institutional Profiles: Some Strategic Tools

Directory of Open Access Journals (Sweden)

Frans van Vught

2014-04-01

Full Text Available In this paper we argue that both internal and external pressures and conditions urge contemporary higher education institutions to carefully think through their institutional profiles positions in domestic and global higher education contexts. We subsequently analyse strategic positioning from the strategic management literature and offer four tools — mapping, multi-dimensional ranking, benchmarking and degree profiling — to assist higher education institutions in their profiling and positioning strategies.

A small mono-polar direct methanol fuel cell stack with passive operation

Science.gov (United States)

Chan, Y. H.; Zhao, T. S.; Chen, R.; Xu, C.

A passive direct methanol fuel cell (DMFC) stack that consists of six unit cells was designed, fabricated, and tested. The stack was tested with different methanol concentrations under ambient conditions. It was found that the stack performance increased when the methanol concentration inside the fuel tank was increased from 2.0 to 6.0 M. The improved performance is primarily due to the increased cell temperature as a result of the exothermic reaction between the permeated methanol and oxygen on the cathode. Moreover, the increased cell temperature enhanced the water evaporation rate on the air-breathing cathode, which significantly reduced water flooding on the cathode and further improved the stack performance. This passive DMFC stack, providing 350 mW at 1.8 V, was successfully applied to power a seagull display kit. The seagull display kit can continuously run for about 4 h on a single charge of 25 cm 3 4.0-M methanol solution.

Stacks with TiN/titanium as the bipolar plate for PEMFCs

International Nuclear Information System (INIS)

Ren, Zhijun; Zhang, Dongming; Wang, Zaiyi

2012-01-01

Proton exchange membrane fuel cell (PEMFC) is a potential alternative for the internal combustion engine. But many problems, such as metallic bipolar plate instead of graphite bipolar plate to decrease the cost, should be solved before its application. Based on the previous results that single cell with TiN/Ti as bipolar plates shows high performance and enough long-time durability, the progress on the stacks with TiN/Ti as bipolar plates is reported in this manuscript. Till now seldom report is focused on stacks because of the complicated processing technique, especially for that with TiN/Ti as bipolar plate. The flow field in the plate is punched from titanium deformation, and two plates are welded by laser welding to form one piece of bipolar plate. The adopted processing techniques for stacks with TiN/Ti as bipolar plate exhibit advantage and feasibility in industry. The power density by weight for the stack is as high as 1353 W kg −1 , although it still has space to be improved. Next work should be focused on the design of flow channel parameters and flow field type based on plastic deformation of metal materials. -- Highlights: ► The progress on the stacks with TiN/Ti as bipolar plates is reported. ► The adopted processing techniques exhibit feasibility in industry. ► The power density by weight for the stack is as high as 1353 W kg −1 .

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...

Optimal Stack Layout in a Sea Container Terminal with Automated Lifting Vehicles

OpenAIRE

Roy, D.; Gupta, A.; Parhi, S.; de Koster, M.B.M.

2014-01-01

textabstractContainer terminal performance is largely determined by its design decisions, which include the number and type of quay cranes (QCs), stack cranes (SCs), transport vehicles, vehicle travel path, and stack layout. The terminal design process is complex because it is affected by factors such as topological constraints, stochastic interactions among the quayside, vehicle transport and stackside operations. Further, the orientation of the stack layout (parallel or perpendicular to the...

Detection and Antigenic Profiling of Undeclared Peanut in Imported Garlic Using an xMAP Multiplex Immunoassay for Food Allergens.

Science.gov (United States)

Pedersen, Ronnie O; Peters, Tim; Panda, Rakhi; Wehling, Paul; Garber, Eric A E

2017-07-01

A shipment of imported garlic powder was suspected of containing peanut. Samples (subs) collected from the shipment displayed considerable variability in peanut antigenicity when analyzed by enzyme-linked immunosorbent assay (ELISA). This raised questions regarding whether peanut was actually present, the amount present, and the basis for the variability in antigenic content. Analyses that used an xMAP multiplex assay for the detection of peanut and additional food allergens generated responses that were characteristic of peanut. Specifically, the relative intensities of two different peanut-specific antibodies coupled to beads (peanut-37 and -38) and the antigen profiles were identical to garlic controls spiked with peanut. In addition, the xMAP data did not indicate the presence of other allergens. Quantitative analyses indicated an approximately fivefold variation in peanut concentration among different subs. In contrast, within a sub, the apparent peanut concentration appeared constant. Particle size analyses of the garlic powder subs indicated a single distribution profile, with a peak at 380 μm. ELISA analysis of sieve-fractionated garlic powder from one of the subs indicated that slightly less than half of the detectable peanut was smaller than 212 μm, with the remainder almost evenly split between 212 and 300 μm and >300 μm. Modeling to predict possible oral exposure levels of peanut other than those directly measured requires additional research on the physicochemical properties of peanut and garlic, along with information on the production of the garlic powder.

Stacked magnet superconducting bearing

International Nuclear Information System (INIS)

Rigney, T.K. II; Saville, M.P.

1993-01-01

A superconducting bearing is described, comprising: a plurality of permanent magnets magnetized end-to-end and stacked side-by-side in alternating polarity, such that flux lines flow between ends of adjacent magnets; isolating means, disposed between said adjacent magnets, for reducing flux leakage between opposing sides of said adjacent magnets; and a member made of superconducting material having at least one surface in communication with said flux lines

Iridium Interfacial Stack (IRIS)

Science.gov (United States)

Spry, David James (Inventor)

2015-01-01

An iridium interfacial stack ("IrIS") and a method for producing the same are provided. The IrIS may include ordered layers of TaSi.sub.2, platinum, iridium, and platinum, and may be placed on top of a titanium layer and a silicon carbide layer. The IrIS may prevent, reduce, or mitigate against diffusion of elements such as oxygen, platinum, and gold through at least some of its layers.

Chernobyl risk reduction via ventilation stack repair: a successful international project

International Nuclear Information System (INIS)

Gore, B.F.; Glukhov, A.Y.; Schmidt, J.P.; Vargo, G.I.; Osterloh, J.V.; Kupny, V.I.; Korneev, A.A.; Matvejev, Y.A.

1999-01-01

The recently completed project to repair the ChNPP Unit 3/4 ventilation stack is the first international project providing a direct physical improvement and safety upgrade at the Shelter (Ukrytie) facility. The 1986 explosion at Chernobyl NPP Unit 4 severely damaged the ventilation stack framework of bracing and its foundation. At one node, where six elements of the framework joined together, one element was completely missing one element was torn from the node and left hanging from its other end, and one element was badly bent and dented. Foundation supports were knocked measurably off plumb. Repair of the ChNPP ventilation stack is the first international project providing direct physical improvement and safety upgrade at the Shelter facility. The repairs have restored the stack to full design strength, from an emergency condition with a high probability of collapse

Device for equalizing molten electrolyte content in a fuel cell stack

Science.gov (United States)

Smith, J.L.

1985-12-23

A device for equalizing the molten electrolyte content throughout the height of a fuel cell stack is disclosed. The device includes a passageway for electrolyte return with electrolyte wettable wicking material in the opposite end portions of the passageway. One end portion is disposed near the upper, negative end of the stack where electrolyte flooding occurs. The second end portion is placed near the lower, positive end of the stack where electrolyte is depleted. Heating means are provided at the upper portion of the passageway to increase electrolyte vapor pressure in the upper wicking material. The vapor is condensed in the lower passageway portion and conducted as molten electrolyte in the lower wick to the positive end face of the stack. An inlet is provided to inject a modifying gas into the passageway and thereby control the rate of electrolyte return.

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

Role of stacking disorder in ice nucleation.

Science.gov (United States)

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

2017-11-08

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

The operation and monitoring of sewage disposal by stack injection

Energy Technology Data Exchange (ETDEWEB)

Jensen, D.A. [Alyeska Pipeline Service Co. (United States)

1994-12-31

A system that uses turbine exhaust to evaporate sewage, was described. The Alyeska Pipeline Service developed the system for isolated pump stations located in permafrost areas. The pumps moving the crude oil in the Trans Alaska Pipeline System (TAPS) were driven by simple cycle gas turbine engines which produce large amounts of waste heat. The waste heat was used to evaporate the sewage effluent, effectively destroying all pathogens in it. The process, known as `stack injection`, was recently upgraded to increase efficiency and safety. Stack injection was being used at five pump stations. Methods used to control operation of the stack injection system, and field data used to redesign the system were reviewed. 3 figs., 3 refs.

Assessment of self-organizing maps to analyze sole-carbon source utilization profiles.

Science.gov (United States)

Leflaive, Joséphine; Céréghino, Régis; Danger, Michaël; Lacroix, Gérard; Ten-Hage, Loïc

2005-07-01

The use of community-level physiological profiles obtained with Biolog microplates is widely employed to consider the functional diversity of bacterial communities. Biolog produces a great amount of data which analysis has been the subject of many studies. In most cases, after some transformations, these data were investigated with classical multivariate analyses. Here we provided an alternative to this method, that is the use of an artificial intelligence technique, the Self-Organizing Maps (SOM, unsupervised neural network). We used data from a microcosm study of algae-associated bacterial communities placed in various nutritive conditions. Analyses were carried out on the net absorbances at two incubation times for each substrates and on the chemical guild categorization of the total bacterial activity. Compared to Principal Components Analysis and cluster analysis, SOM appeared as a valuable tool for community classification, and to establish clear relationships between clusters of bacterial communities and sole-carbon sources utilization. Specifically, SOM offered a clear bidimensional projection of a relatively large volume of data and were easier to interpret than plots commonly obtained with multivariate analyses. They would be recommended to pattern the temporal evolution of communities' functional diversity.

Depth profile measurement with lenslet images of the plenoptic camera

Science.gov (United States)

Yang, Peng; Wang, Zhaomin; Zhang, Wei; Zhao, Hongying; Qu, Weijuan; Zhao, Haimeng; Asundi, Anand; Yan, Lei

2018-03-01

An approach for carrying out depth profile measurement of an object with the plenoptic camera is proposed. A single plenoptic image consists of multiple lenslet images. To begin with, these images are processed directly with a refocusing technique to obtain the depth map, which does not need to align and decode the plenoptic image. Then, a linear depth calibration is applied based on the optical structure of the plenoptic camera for depth profile reconstruction. One significant improvement of the proposed method concerns the resolution of the depth map. Unlike the traditional method, our resolution is not limited by the number of microlenses inside the camera, and the depth map can be globally optimized. We validated the method with experiments on depth map reconstruction, depth calibration, and depth profile measurement, with the results indicating that the proposed approach is both efficient and accurate.

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.

Snow-covered Landsat time series stacks improve automated disturbance mapping accuracy in forested landscapes

Science.gov (United States)

Kirk M. Stueve; Ian W. Housman; Patrick L. Zimmerman; Mark D. Nelson; Jeremy B. Webb; Charles H. Perry; Robert A. Chastain; Dale D. Gormanson; Chengquan Huang; Sean P. Healey; Warren B. Cohen

2011-01-01

Accurate landscape-scale maps of forests and associated disturbances are critical to augment studies on biodiversity, ecosystem services, and the carbon cycle, especially in terms of understanding how the spatial and temporal complexities of damage sustained from disturbances influence forest structure and function. Vegetation change tracker (VCT) is a highly automated...

Taxonomy of multi-focal nematode image stacks by a CNN based image fusion approach.

Science.gov (United States)

Liu, Min; Wang, Xueping; Zhang, Hongzhong

2018-03-01

In the biomedical field, digital multi-focal images are very important for documentation and communication of specimen data, because the morphological information for a transparent specimen can be captured in form of a stack of high-quality images. Given biomedical image stacks containing multi-focal images, how to efficiently extract effective features from all layers to classify the image stacks is still an open question. We present to use a deep convolutional neural network (CNN) image fusion based multilinear approach for the taxonomy of multi-focal image stacks. A deep CNN based image fusion technique is used to combine relevant information of multi-focal images within a given image stack into a single image, which is more informative and complete than any single image in the given stack. Besides, multi-focal images within a stack are fused along 3 orthogonal directions, and multiple features extracted from the fused images along different directions are combined by canonical correlation analysis (CCA). Because multi-focal image stacks represent the effect of different factors - texture, shape, different instances within the same class and different classes of objects, we embed the deep CNN based image fusion method within a multilinear framework to propose an image fusion based multilinear classifier. The experimental results on nematode multi-focal image stacks demonstrated that the deep CNN image fusion based multilinear classifier can reach a higher classification rate (95.7%) than that by the previous multilinear based approach (88.7%), even we only use the texture feature instead of the combination of texture and shape features as in the previous work. The proposed deep CNN image fusion based multilinear approach shows great potential in building an automated nematode taxonomy system for nematologists. It is effective to classify multi-focal image stacks. Copyright © 2018 Elsevier B.V. All rights reserved.

Retrofitting of an improved stack monitoring system in Rajasthan atomic power station

International Nuclear Information System (INIS)

Natarajan, K.

1985-01-01

The problems encountered in the measurement of inert gas activities, iodine activity and tritium activity released through the stack in RAPS are described and the considerations for the development of improved instruments outlined. The new approach provides for better accuracy of measurement of all the relevant radioactive parameters in the stack at one centralised place. The construction work in the station for the newly conceived stack activity monitoring system is completed and the earlier equipment used is installed in the room temporarily. Development prototypes of stack inert gas monitoring system and iodine monitoring system as described in Section 5 are made and evaluated. Fabrication of new equipment for retrofitting in RAPS is in progress and these will replace the equipment temporarily installed in the station

Continued maturing of SOFC cell production technology and development and demonstration of SOFC stacks. Final report

Energy Technology Data Exchange (ETDEWEB)

2008-08-15

The overall objective of the 6385 project was to develop stack materials, components and stack technology including industrial relevant manufacturing methods for cells components and stacks. Furthermore, the project should include testing and demonstration of the stacks under relevant operating conditions. A production of 6.829 cells, twenty 75-cell stacks and a number of small stacks was achieved. Major improvements were also made in the manufacturing methods and in stack design. Two test and demonstration activities were included in the project. The first test unit was established at H.C. OErsted power plant at the Copenhagen waterfront in order to perform test of SOFC stacks. The unit will be used for tests in other projects. The second demonstration unit is the alpha prototype demonstration in a system running on natural gas in Finland. The alpha prototype demonstration system with 24 TOFC (Topsoe Fuel Cell) stacks was established and started running in October 2007 and operational experience was gained in the period from October 2007 to February 2008. (auther)

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

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

Cell design and image analysis for in situ Raman mapping of inhomogeneous state-of-charge profiles in lithium-ion batteries

Science.gov (United States)

Fang, Shuyu; Yan, Min; Hamers, Robert J.

2017-06-01

The study of inhomogeneous battery failure processes requires proper tools with high spatial resolving power. Here we describe a simple way to adapt industry-standard coin cells to enable in situ Raman mapping of lithium-ion battery materials. We describe the important cell design parameters and validate that the design achieves a uniform potential distribution within the region probed by Raman. We further validate that the cell yields electrical performance characteristics equivalent to a standard, non-modified coin cell. Using this cell, we probe the local charging profiles of LiNi0.5Mn0.3Co0.2O2 ("NMC") particles during cycling and demonstrate the ability to achieve spatial maps of the Raman spectra. In order to reduce the effects of local topography, we further analyze these data by numerically extracting the local frequency of the A1g vibrational mode, which is sensitive to the local extent of lithiation, and producing spatial maps of the local frequency of the A1g mode. This work demonstrates a way to collect and analyze high quality in situ spectra with an easy-to-implement cell design that can be applied to a wide range of electrode materials.

Temperature dependence of stacking faults in catalyst-free GaAs nanopillars.

Science.gov (United States)

Shapiro, Joshua N; Lin, Andrew; Ratsch, Christian; Huffaker, D L

2013-11-29

Impressive opto-electronic devices and transistors have recently been fabricated from GaAs nanopillars grown by catalyst-free selective-area epitaxy, but this growth technique has always resulted in high densities of stacking faults. A stacking fault occurs when atoms on the growing (111) surface occupy the sites of a hexagonal-close-pack (hcp) lattice instead of the normal face-centered-cubic (fcc) lattice sites. When stacking faults occur consecutively, the crystal structure is locally wurtzite instead of zinc-blende, and the resulting band offsets are known to negatively impact device performance. Here we present experimental and theoretical evidence that indicate stacking fault formation is related to the size of the critical nucleus, which is temperature dependent. The difference in energy between the hcp and fcc orientation of small nuclei is computed using density-function theory. The minimum energy difference of 0.22 eV is calculated for a nucleus with 21 atoms, so the population of nuclei in the hcp orientation is expected to decrease as the nucleus grows larger. The experiment shows that stacking fault occurrence is dramatically reduced from 22% to 3% by raising the growth temperature from 730 to 790 ° C. These data are interpreted using classical nucleation theory which dictates a larger critical nucleus at higher growth temperature.

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.

Moving object detection in top-view aerial videos improved by image stacking

Science.gov (United States)

Teutsch, Michael; Krüger, Wolfgang; Beyerer, Jürgen

2017-08-01

Image stacking is a well-known method that is used to improve the quality of images in video data. A set of consecutive images is aligned by applying image registration and warping. In the resulting image stack, each pixel has redundant information about its intensity value. This redundant information can be used to suppress image noise, resharpen blurry images, or even enhance the spatial image resolution as done in super-resolution. Small moving objects in the videos usually get blurred or distorted by image stacking and thus need to be handled explicitly. We use image stacking in an innovative way: image registration is applied to small moving objects only, and image warping blurs the stationary background that surrounds the moving objects. Our video data are coming from a small fixed-wing unmanned aerial vehicle (UAV) that acquires top-view gray-value images of urban scenes. Moving objects are mainly cars but also other vehicles such as motorcycles. The resulting images, after applying our proposed image stacking approach, are used to improve baseline algorithms for vehicle detection and segmentation. We improve precision and recall by up to 0.011, which corresponds to a reduction of the number of false positive and false negative detections by more than 3 per second. Furthermore, we show how our proposed image stacking approach can be implemented efficiently.

Fluxons in long and annular intrinsic Josephson junction stacks

CERN Document Server

Clauss, T; Moessle, M; Müller, A; Weber, A; Kölle, D; Kleiner, R

2002-01-01

A promising approach towards a THz oscillator based on intrinsic Josephson junctions in high-temperature superconductors is based on the collective motion of Josephson fluxons, which are predicted to form various configurations ranging from a triangular to a quadratic lattice. Not only for this reason, but certainly also for the sake of basic physics, several experimental and theoretical investigations have been done on the subject of collective fluxon dynamics in stacked intrinsic Josephson junctions. In this paper we will present some experimental results on the fluxon dynamics of long intrinsic Josephson junction stacks made of Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8. The stacks were formed either in an open or in an annular geometry, and clear resonant fluxon modes were observed. Experiments discussed include measurements of current-voltage characteristics in external magnetic fields and in external microwave fields.

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

Halo Profiles and the Concentration–Mass Relation for a ΛCDM Universe

Science.gov (United States)

Child, Hillary L.; Habib, Salman; Heitmann, Katrin; Frontiere, Nicholas; Finkel, Hal; Pope, Adrian; Morozov, Vitali

2018-05-01

Profiles of dark matter-dominated halos at the group and cluster scales play an important role in modern cosmology. Using results from two very large cosmological N-body simulations, which increase the available volume at their mass resolution by roughly two orders of magnitude, we robustly determine the halo concentration–mass (c‑M) relation over a wide range of masses, employing multiple methods of concentration measurement. We characterize individual halo profiles, as well as stacked profiles, relevant for galaxy–galaxy lensing and next-generation cluster surveys; the redshift range covered is 0 ≤ z ≤ 4, with a minimum halo mass of M 200c ∼ 2 × 1011 M ⊙. Despite the complexity of a proper description of a halo (environmental effects, merger history, nonsphericity, relaxation state), when the mass is scaled by the nonlinear mass scale M ⋆(z), we find that a simple non-power-law form for the c–M/M ⋆ relation provides an excellent description of our simulation results across eight decades in M/M ⋆ and for 0 ≤ z ≤ 4. Over the mass range covered, the c–M relation has two asymptotic forms: an approximate power law below a mass threshold M/M ⋆ ∼ 500–1000, transitioning to a constant value, c 0 ∼ 3 at higher masses. The relaxed halo fraction decreases with mass, transitioning to a constant value of ∼0.5 above the same mass threshold. We compare Navarro–Frenk–White (NFW) and Einasto fits to stacked profiles in narrow mass bins at different redshifts; as expected, the Einasto profile provides a better description of the simulation results. At cluster scales at low redshift, however, both NFW and Einasto profiles are in very good agreement with the simulation results, consistent with recent weak lensing observations.

Image transfer by cascaded stack of photonic crystal and air layers

NARCIS (Netherlands)

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

2006-01-01

We demonstrate image transfer by a cascaded stack consisting of two and three triangular-lattice photonic crystal slabs separated by air. The quality of the image transfered by the stack is sensitive to the air/photonic crystal interface termination and the frequency. Depending on the frequency and

Influence factors of the inter-nanowire thermal contact resistance in the stacked nanowires

Science.gov (United States)

Wu, Dongxu; Huang, Congliang; Zhong, Jinxin; Lin, Zizhen

2018-05-01

The inter-nanowire thermal contact resistance is important for tuning the thermal conductivity of a nanocomposite for thermoelectric applications. In this paper, the stacked copper nanowires are applied for studying the thermal contact resistance. The stacked copper nanowires are firstly made by the cold-pressing method, and then the nanowire stacks are treated by sintering treatment. With the effect of the volumetric fraction of nanowires in the stack and the influence of the sintering-temperature on the thermal contact resistance discussed, results show that: The thermal conductivity of the 150-nm copper nanowires can be enlarged almost 2 times with the volumetric fraction increased from 32 to 56% because of the enlarged contact-area and contact number of a copper nanowire. When the sintering temperature increases from 293 to 673 K, the thermal conductivity of the stacked 300-nm nanowires could be enlarged almost 2.5 times by the sintering treatment, because of the improved lattice property of the contact zone. In conclusion, application of a high volumetric fraction or/and a sintering-treatment are effectivity to tune the inter-nanowire thermal contact resistance, and thus to tailor the thermal conductivity of a nanowire network or stack.

Assessment of the seismic resistance of a ventilation stack on a reactor building

International Nuclear Information System (INIS)

Makovicka, Daniel; Makovicka, Daniel

2005-01-01

The paper analyzes the seismic resistance of a ventilation stack on a reactor building, including the possible reserves of increasing the resistance. Structures of this type are highly sensitive to seismic loads, as the tuning of the stack (the spectrum of its lowest natural frequencies) corresponds with the frequency spectrum of excitation due to seismic effects. The purpose of the paper is to present an example of an actual structure to show the character of the response of the structure, and the participation of the individual frequency components of the response in the overall stress and strain state of a structure of this type. The methodology for a numerical analysis of the structure is also given. The load of the stack proper is modified by the transfer characteristics of the building. In engineering practice, the system is usually divided into two subsystems: the building with the sub-base, and the stack proper. The level of justification for the application of this simplification depends on the distance of the natural frequencies of the stack from the natural frequencies of the building. Finally, the paper deals with possible errors in determining the actual seismic resistance of the stack structure

Long-term operation of a solid oxide cell stack for coelectrolysis of steam and CO2

DEFF Research Database (Denmark)

Agersted, Karsten; Chen, Ming; Blennow, Peter

2016-01-01

of synthetic fuels such as methane, methanol or DME. Previously we have reported electrolysis operation of solid oxide cell stacks for periods up to about 1000 hours. In this work, operation of a Haldor Topsoe 8-cell stack (stack design of 2014) in co-electrolysis mode for 6000 hours is reported. The stack....... Initial operation at 700 oC and -0.25 A/cm2 lasted for only 120 hours due to severe degradation of the bottom cell. Regaining the stack performance was realized by increasing the operation temperature to 750 oC. After reactivation, the stack showed negligible degradation at 750 oC and -0.25 A/cm2...... and about 1.4 %/1000 h performance degradation at 750 oC and -0.5 A/cm2. This study demonstrates feasibility of long-term co-electrolysis operation via SOEC stacks and of careful temperature variation as a tool to regain the stack performance....

Linear identification and model adjustment of a PEM fuel cell stack

Energy Technology Data Exchange (ETDEWEB)

Kunusch, C; Puleston, P F; More, J J [LEICI, Departamento de Electrotecnia, Universidad Nacional de La Plata, calle 1 esq. 47 s/n, 1900 La Plata (Argentina); Consejo de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Husar, A [Institut de Robotica i Informatica Industrial (CSIC-UPC), c/ Llorens i Artigas 4-6, 08028 Barcelona (Spain); Mayosky, M A [LEICI, Departamento de Electrotecnia, Universidad Nacional de La Plata, calle 1 esq. 47 s/n, 1900 La Plata (Argentina); Comision de Investigaciones Cientificas (CIC), Provincia de Buenos Aires (Argentina)

2008-07-15

In the context of fuel cell stack control a mayor challenge is modeling the interdependence of various complex subsystem dynamics. In many cases, the states interaction is usually modeled through several look-up tables, decision blocks and piecewise continuous functions. Many internal variables are inaccessible for measurement and cannot be used in control algorithms. To make significant contributions in this area, it is necessary to develop reliable models for control and design purposes. In this paper, a linear model based on experimental identification of a 7-cell stack was developed. The procedure followed to obtain a linear model of the system consisted in performing spectroscopy tests of four different single-input single-output subsystems. The considered inputs for the tests were the stack current and the cathode oxygen flow rate, while the measured outputs were the stack voltage and the cathode total pressure. The resulting model can be used either for model-based control design or for on-line analysis and errors detection. (author)

Spherical distribution structure of the semiconductor laser diode stack for pumping

International Nuclear Information System (INIS)

Zhao Tianzhuo; Yu Jin; Liu Yang; Zhang Xue; Ma Yunfeng; Fan Zhongwei

2011-01-01

A semiconductor laser diode stack is used for pumping and 8 semiconductor laser diode arrays of the stack are put on a sphere, and the output of every bar is specially off-axis compressed to realize high coupling efficiency. The output beam of this semiconductor laser diode stack is shaped by a hollow duct to the laser active medium. The efficiency of the hollow light pipe, which is used for semiconductor laser diode stack coupling, is analyzed by geometric optics and ray tracing. Geometric optics analysis diagnoses the reasons for coupling loss and guides the design of the structure. Ray tracing analyzes the relation between the structural parameters and the output characteristics of this pumping system, and guides parameter optimization. Simulation and analysis results show that putting the semiconductor laser diode arrays on a spherical surface can increase coupling efficiency, reduce the optimum duct length and improve the output energy field distribution. (semiconductor devices)

Simulation and resolution of voltage reversal in microbial fuel cell stack.

Science.gov (United States)

Sugnaux, Marc; Savy, Cyrille; Cachelin, Christian Pierre; Hugenin, Gérald; Fischer, Fabian

2017-08-01

To understand the biotic and non-biotic contributions of voltage reversals in microbial fuel cell stacks (MFC) they were simulated with an electronic MFC-Stack mimic. The simulation was then compared with results from a real 3L triple MFC-Stack with shared anolyte. It showed that voltage reversals originate from the variability of biofilms, but also the external load plays a role. When similar biofilm properties were created on all anodes the likelihood of voltage reversals was largely reduced. Homogenous biofilms on all anodes were created by electrical circuit alternation and electrostimulation. Conversely, anolyte recirculation, or increased nutriment supply, postponed reversals and unfavourable voltage asymmetries on anodes persisted. In conclusion, voltage reversals are often a negative event but occur also in close to best MFC-Stack performance. They were manageable and this with a simplified MFC architecture in which multiple anodes share the same anolyte. Copyright © 2017 Elsevier Ltd. All rights reserved.

Element stacking method for topology optimization with material-dependent boundary and loading conditions

DEFF Research Database (Denmark)

Yoon, Gil Ho; Park, Y.K.; Kim, Y.Y.

2007-01-01

A new topology optimization scheme, called the element stacking method, is developed to better handle design optimization involving material-dependent boundary conditions and selection of elements of different types. If these problems are solved by existing standard approaches, complicated finite...... element models or topology optimization reformulation may be necessary. The key idea of the proposed method is to stack multiple elements on the same discretization pixel and select a single or no element. In this method, stacked elements on the same pixel have the same coordinates but may have...... independent degrees of freedom. Some test problems are considered to check the effectiveness of the proposed stacking method....

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.

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

Science.gov (United States)

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

2017-04-01

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

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...... model to simulate the temperature development of a fuel cell stack during heating can be used for assistance in system and control design. The heating strategies analyzed and tested reduced the startup time of one of the fuel cell stacks from 1 h to about 6 min....

Gravitational redshift and asymmetric redshift-space distortions for stacked clusters

Science.gov (United States)

Cai, Yan-Chuan; Kaiser, Nick; Cole, Shaun; Frenk, Carlos

2017-06-01

We derive the expression for the observed redshift in the weak field limit in the observer's past light cone, including all relativistic terms up to second order in velocity. We then apply it to compute the cluster-galaxy cross-correlation functions (CGCF) using N-body simulations. The CGCF is asymmetric along the line of sight owing to the presence of the small second-order terms such as the gravitational redshift (GRedshift). We identify two systematics in the modelling of the GRedshift signal in stacked clusters. First, it is affected by the morphology of dark matter haloes and the large-scale cosmic-web. The non-spherical distribution of galaxies around the central halo and the presence of neighbouring clusters systematically reduce the GRedshift signal. This bias is approximately 20 per cent for Mmin ≃ 1014 M⊙ h-1, and is more than 50 per cent for haloes with Mmin ≃ 2 × 1013 M⊙ h-1 at r > 4 Mpc h-1. Secondly, the best-fitting GRedshift profiles as well as the profiles of all other relativistic terms are found to be significantly different in velocity space compared to their real space versions. We find that the relativistic Doppler redshift effect, like other second-order effects, is subdominant to the GRedshift signal. We discuss some subtleties relating to these effects in velocity space. We also find that the S/N of the GRedshift signal increases with decreasing halo mass.

Gait profile score and movement analysis profile in patients with Parkinson's disease during concurrent cognitive load

Science.gov (United States)

Speciali, Danielli S.; Oliveira, Elaine M.; Cardoso, Jefferson R.; Correa, João C. F.; Baker, Richard; Lucareli, Paulo R. G.

2014-01-01

Background: Gait disorders are common in individuals with Parkinson's Disease (PD) and the concurrent performance of motor and cognitive tasks can have marked effects on gait. The Gait Profile Score (GPS) and the Movement Analysis Profile (MAP) were developed in order to summarize the data of kinematics and facilitate understanding of the results of gait analysis. Objective: To investigate the effectiveness of the GPS and MAP in the quantification of changes in gait during a concurrent cognitive load while walking in adults with and without PD. Method: Fourteen patients with idiopathic PD and nine healthy subjects participated in the study. All subjects performed single and dual walking tasks. The GPS/MAP was computed from three-dimensional gait analysis data. Results: Differences were found between tasks for GPS (PGait Variable Score (GVS) (pelvic rotation, knee flexion-extension and ankle dorsiflexion-plantarflexion) (Pgait impairment during the dual task and suggest that GPS/MAP may be used to evaluate the effects of concurrent cognitive load while walking in patients with PD. PMID:25054382

A “4-cell” modular passive DMFC (direct methanol fuel cell) stack for portable applications

International Nuclear Information System (INIS)

Wang, Luwen; He, Mingyan; Hu, Yue; Zhang, Yufeng; Liu, Xiaowei; Wang, Gaofeng

2015-01-01

A “4-cell” modular passive DMFC (direct methanol fuel cell) stack, which can be freely combined and applied to various electronic devices, is designed, fabricated and tested. Two PCB (printed circuit board) based accessories are designed and fabricated for electrically connecting and mechanically assembling the “4-cell” modules. The maximum power density of the “4-cell” module is 27 mW cm −2 at 5 M methanol concentration. The steady-state performances of the modular stacks with different numbers of modules are tested. The extra power loss of the multiple module stacks due to inter-module electrical connections is predicted by mathematical fitting method. The fitting results indicate that the efficiencies of the multiple module stacks are all above 90% up to 10 modules. The dynamic performances of the modular stacks are also investigated for portable applications. The results show that the modular stacks exhibit good responsiveness and reproducibility at high loading current (>100 mA). Finally, the modular stacks are successfully applied to drive the experimental fan and charge the mobile phone. - Highlights: • A “4-cell” modular passive DMFC (direct methanol fuel cell) stack is designed, fabricated and tested. • This modular DMFC stack can assemble more single cells with high efficiency. • The modular stack exhibit good responsiveness and reproducibility for portable application

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.

Computational fluid dynamics simulations of single-phase flow in a filter-press flow reactor having a stack of three cells

International Nuclear Information System (INIS)

Sandoval, Miguel A.; Fuentes, Rosalba; Walsh, Frank C.; Nava, José L.; Ponce de León, Carlos

2016-01-01

Highlights: • Computational fluid dynamic simulations in a filter-press stack of three cells. • The fluid velocity was different in each cell due to local turbulence. • The upper cell link pipe of the filter press cell acts as a fluid mixer. • The fluid behaviour tends towards a continuous mixing flow pattern. • Close agreement between simulations and experimental data was achieved. - Abstract: Computational fluid dynamics (CFD) simulations were carried out for single-phase flow in a pre-pilot filter press flow reactor with a stack of three cells. Velocity profiles and streamlines were obtained by solving the Reynolds-Averaged Navier-Stokes (RANS) equations with a standard k − ε turbulence model. The flow behaviour shows the appearance of jet flow at the entrance to each cell. At lengths from 12 to 15 cm along the cells channels, a plug flow pattern is developed at all mean linear flow rates studied here, 1.2 ≤ u ≤ 2.1 cm s −1 . The magnitude of the velocity profiles in each cell was different, due to the turbulence generated by the change of flow direction in the last fluid manifold. Residence time distribution (RTD) simulations indicated that the fluid behaviour tends towards a continuous mixing flow pattern, owing to flow at the output of each cell across the upper cell link pipe, which acts as a mixer. Close agreement between simulations and experimental RTD was obtained.

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 in ...... are developed for the problem and used with each of the heuristics. Finally some computational results are given along with lower bounds on the objective value....

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 in ...... are developed for the problem and used with each of the heuristics. Finally some computational results are given along with lower bounds on the objective value....

Lower power by voltage stacking : a fine-grained system design approach

NARCIS (Netherlands)

Blutman, K.; Kapoor, A.; Martinez, J.G.; Fatemi, S.H.; Pineda de Gyvez, J.

2016-01-01

Stacking voltage domains on top of each other is a design approach that is getting the attention of engineering communities due to the implicit high efficiency of the power delivery. Previous works have shown voltage stacking at the core level only. In this paper we present a more involved approach

Test Plan for Long-Term Operation of a Ten-Cell High Temperature Electrolysis Stack

International Nuclear Information System (INIS)

James E. O'Brien; Carl M. Stoots; J. Stephen Herring

2008-01-01

This document defines a test plan for a long-term (2500 Hour) test of a ten-cell high-temperature electrolysis stack to be performed at INL during FY09 under the Nuclear Hydrogen Initiative. This test was originally planned for FY08, but was removed from our work scope as a result of the severe budget cuts in the FY08 NHI Program. The purpose of this test is to evaluate stack performance degradation over a relatively long time period and to attempt to identify some of the degradation mechanisms via post-test examination. This test will be performed using a planar ten-cell Ceramatec stack, with each cell having dimensions of 10 cm x 10 cm. The specific makeup of the stack will be based on the results of a series of shorter duration ten-cell stack tests being performed during FY08, funded by NGNP. This series of tests was aimed at evaluating stack performance with different interconnect materials and coatings and with or without brazed edge rails. The best performing stack from the FY08 series, in which five different interconnect/coating/edge rail combinations were tested, will be selected for the FY09 long-term test described herein

Electricity generation and microbial community in response to short-term changes in stack connection of self-stacked submersible microbial fuel cell powered by glycerol

DEFF Research Database (Denmark)

Zhao, Nannan; Angelidaki, Irini; Zhang, Yifeng

2017-01-01

community. In this study, a self-stacked submersible microbial fuel cell (SSMFC) powered by glycerol was tested to elucidate this important issue. In series connection, the maximum voltage output reached to 1.15 V, while maximum current density was 5.73 mA in parallel. In both connections, the maximum power......Stack connection (i.e., in series or parallel) of microbial fuel cell (MFC) is an efficient way to boost the power output for practical application. However, there is little information available on short-term changes in stack connection and its effect on the electricity generation and microbial...... density increased with the initial glycerol concentration. However, the glycerol degradation was even faster in parallel connection. When the SSMFC was shifted from series to parallel connection, the reactor reached to a stable power output without any lag phase. Meanwhile, the anodic microbial community...

The Influence of the Density of Coconut Fiber as Stack in Thermo-Acoustics Refrigeration System

Science.gov (United States)

Hartulistiyoso, E.; Yulianto, M.; Sucahyo, L.

2018-05-01

An experimental study of using coconut fiber as stack with varying density in thermo-acoustics refrigeration system has been done. Stack is a device which is described as the “heart” in thermo-acoustics refrigeration system. The length of stack is a fix parameter in this experiment. The performance of the coconut fiber was evaluated from the density of stack (varied from 30%, 50% and 70%), position of stack (varied from 0 to 34 cm from the sound generator), and frequency of sound generator (varied from 150 Hz, 200Hz, 250Hz and 300Hz). The inside, outside, and environment temperatures were collected every second using Data Acquisition (DAQ). The result showed that the increase of stack density will increase the performance of thermo-acoustics refrigeration system. The higher density produced temperature differences in cold side and hot side of 5.4°C. In addition, the position of stack and frequency of sound generator have an important role in the performance of thermo-acoustics refrigeration system for all variations of the density.

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

Single-Event Transgene Product Levels Predict Levels in Genetically Modified Breeding Stacks.

Science.gov (United States)

Gampala, Satyalinga Srinivas; Fast, Brandon J; Richey, Kimberly A; Gao, Zhifang; Hill, Ryan; Wulfkuhle, Bryant; Shan, Guomin; Bradfisch, Greg A; Herman, Rod A

2017-09-13

The concentration of transgene products (proteins and double-stranded RNA) in genetically modified (GM) crop tissues is measured to support food, feed, and environmental risk assessments. Measurement of transgene product concentrations in breeding stacks of previously assessed and approved GM events is required by many regulatory authorities to evaluate unexpected transgene interactions that might affect expression. Research was conducted to determine how well concentrations of transgene products in single GM events predict levels in breeding stacks composed of these events. The concentrations of transgene products were compared between GM maize, soybean, and cotton breeding stacks (MON-87427 × MON-89034 × DAS-Ø15Ø7-1 × MON-87411 × DAS-59122-7 × DAS-40278-9 corn, DAS-81419-2 × DAS-44406-6 soybean, and DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 × MON-88913-8 × DAS-81910-7 cotton) and their component single events (MON-87427, MON-89034, DAS-Ø15Ø7-1, MON-87411, DAS-59122-7, and DAS-40278-9 corn, DAS-81419-2, and DAS-44406-6 soybean, and DAS-21023-5, DAS-24236-5, SYN-IR102-7, MON-88913-8, and DAS-81910-7 cotton). Comparisons were made within a crop and transgene product across plant tissue types and were also made across transgene products in each breeding stack for grain/seed. Scatter plots were generated comparing expression in the stacks to their component events, and the percent of variability accounted for by the line of identity (y = x) was calculated (coefficient of identity, I 2 ). Results support transgene concentrations in single events predicting similar concentrations in breeding stacks containing the single events. Therefore, food, feed, and environmental risk assessments based on concentrations of transgene products in single GM events are generally applicable to breeding stacks composed of these events.

Density Functional Study of Stacking Structures and Electronic Behaviors of AnE-PV Copolymer.

Science.gov (United States)

Dong, Chuan-Ding; Beenken, Wichard J D

2016-10-10

In this work, we report an in-depth investigation on the π-stacking and interdigitating structures of poly(p-anthracene-ethynylene)-alt-poly(p-phenylene-vinylene) copolymer with octyl and ethyl-hexyl side chains and the resulting electronic band structures using density functional theory calculations. We found that in the π-stacking direction, the preferred stacking structure, determined by the steric effect of the branched ethyl-hexyl side chains, is featured by the anthracene-ethynylene units stacking on the phenylene-vinylene units of the neighboring chains and vice versa. This stacking structure, combined with the interdigitating structure where the branched side chains of the laterally neighboring chains are isolated, defines the energetically favorable structure of the ordered copolymer phase, which provides a good compromise between light absorption and charge-carrier transport.

Drift Wave Test Particle Transport in Reversed Shear Profile

International Nuclear Information System (INIS)

Horton, W.; Park, H.B.; Kwon, J.M.; Stronzzi, D.; Morrison, P.J.; Choi, D.I.

1998-01-01

Drift wave maps, area preserving maps that describe the motion of charged particles in drift waves, are derived. The maps allow the integration of particle orbits on the long time scale needed to describe transport. Calculations using the drift wave maps show that dramatic improvement in the particle confinement, in the presence of a given level and spectrum of E x B turbulence, can occur for q(r)-profiles with reversed shear. A similar reduction in the transport, i.e. one that is independent of the turbulence, is observed in the presence of an equilibrium radial electric field with shear. The transport reduction, caused by the combined effects of radial electric field shear and both monotonic and reversed shear magnetic q-profiles, is also investigated

Bipolarly stacked electrolyser for energy and space efficient fabrication of supercapacitor electrodes

Science.gov (United States)

Liu, Xiaojuan; Wu, Tao; Dai, Zengxin; Tao, Keran; Shi, Yong; Peng, Chuang; Zhou, Xiaohang; Chen, George Z.

2016-03-01

Stacked electrolysers with titanium bipolar plates are constructed for electrodeposition of polypyrrole electrodes for supercapacitors. The cathode side of the bipolar Ti plates are pre-coated with activated carbon. In this new design, half electrolysis occurs which significantly lowers the deposition voltage. The deposited electrodes are tested in a symmetrical unit cell supercapacitor and an asymmetrical supercapacitor stack. Both devices show excellent energy storage performances and the capacitance values are very close to the design value, suggesting a very high current efficiency during the electrodeposition. The electrolyser stack offers multi-fold benefits for preparation of conducting polymer electrodes, i.e. low energy consumption, facile control of the electrode capacitance and simultaneous preparation of a number of identical electrodes. Therefore, the stacked bipolar electrolyser is a technology advance that offers an engineering solution for mass production of electrodeposited conducting polymer electrodes for supercapacitors.

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 ...

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

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

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...

Toward advising SME's on stacked funding

NARCIS (Netherlands)

Rauwerda, Kirsten; van Teeffelen, Lex; de Graaf, Frank Jan

2017-01-01

This paper addresses new funding issues faced by SMEs. Over a period of nine months, the authors conducted a preliminary study into the problems surrounding stacked funding faced by SMEs and their financial advisers. The study includes a short literature review, the outcomes of three round table

Integrated fuel cell stack shunt current prevention arrangement

Energy Technology Data Exchange (ETDEWEB)

Roche, Robert P. (Cheshire, CT); Nowak, Michael P. (Bolton, CT)

1992-01-01

A fuel cell stack includes a plurality of fuel cells juxtaposed with one another in the stack and each including a pair of plate-shaped anode and cathode electrodes that face one another, and a quantity of liquid electrolyte present at least between the electrodes. A separator plate is interposed between each two successive electrodes of adjacent ones of the fuel cells and is unified therewith into an integral separator plate. Each integral separator plate is provided with a circumferentially complete barrier that prevents flow of shunt currents onto and on an outer peripheral surface of the separator plate. This barrier consists of electrolyte-nonwettable barrier members that are accommodated, prior to the formation of the integral separator plate, in corresponding edge recesses situated at the interfaces between the electrodes and the separator plate proper. Each barrier member extends over the entire length of the associated marginal portion and is flush with the outer periphery of the integral separator plate. This barrier also prevents cell-to-cell migration of any electrolyte that may be present at the outer periphery of the integral separator plate while the latter is incorporated in the fuel cell stack.

A microcontroller with 96% power-conversion efficiency using stacked voltage domains

NARCIS (Netherlands)

Blutman, K.; Kapoor, A.; Majumdar, A.; Martinez, J.G.; Echeverri, J.; Sevat, L.; Van Der Wel, A.; Fatemi, H.; Pineda de Gyvez, J.; Makinwa, K.

2016-01-01

This paper presents a CMOS 40nm microcontroller where for the first time, stacked voltage domains are used. The system features an ARM Cortex M0+ processor, 4kB ROM, 16kB SRAM, peripherals, and an on-chip switched-capacitor voltage regulator (SCVR). By using voltage stacking the test chip achieves

Docker on OpenStack

OpenAIRE

Agarwal, Nitin; Moreira, Belmiro

2014-01-01

Project Specification CERN is establishing a large scale private cloud based on OpenStack as part of the expansion of the computing infrastructure for storing the data coming out of the Large Hadron Collider (LHC) experiments. As the data coming out of the detectors is increasing continuously that needs to be stored in the data center, we need more physical resources (more money) and since Virtual machines takes lot of CPU and memory overhead and minutes for creating the images, booting u...

Quality Assurance of Solid Oxide Fuel Cell (SOFC) and Electrolyser (SOEC) Stacks

DEFF Research Database (Denmark)

Lang, Michael; Auer, Corinna; Couturier, Karine

2017-01-01

In the EU-funded project “Solid oxide cell and stack testing and quality assurance” (SOCTESQA) standardized and industry wide test modules and programs for high temperature solid oxide cells and stacks are being developed. These test procedures can be applied for the fuel cell (SOFC......), the electrolysis (SOEC) and in the combined SOFC/SOEC mode. In order to optimize the test modules the project partners have tested identical SOC stacks with the same test programs in several testing campaigns. Altogether 10 pre-normative test modules were developed: Start-up, current-voltage characteristics...

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.

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.

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... Power Module for Parasitic Inductance Extraction 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Steven Kaplan

a comparative survey on mind mapping tools

Directory of Open Access Journals (Sweden)

Avgoustos A. TSINAKOS

2009-07-01

Full Text Available Mind Mapping is an important technique that improves the way you takes notes, and enhances your creative problem solving. By using Mind Maps, you can quickly identify and understand the structure of a subject and the way that pieces of information fit together, as well as recording the raw facts contained in normal notes. It can also be used as complementary tools for knowledge construction and sharing. Their suitability as a pedagogical tool for education, e-learning and training, increases their importance. Also, in a world of information overload and businesses struggling to keep up with the place of change, knowledge workers need effective tools to organize, analyze, brainstorm and collaborate on ideas. In resent years, a wide variety of mind mapping software tools have been developed. An often question that comes up, due to this plethora of software tools, is “which is the best mind mapping software?” Anyone who gives you an immediate answer either knows you and your mind mapping activities very well or their answer in not worth a lot. The “best” depends so much on how you use mind maps. In this paper we are trying to investigate different user profiles and to identify various axes for comparison among mind mapping tools that are suitable for a specific user profile, describe each axis and then analyze each tool.

Analyses of plasma parameter profiles in JT-60U

Energy Technology Data Exchange (ETDEWEB)

Shirai, Hiroshi; Shimizu, Katsuhiro; Hayashi, Nobuhiko [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Itakura, Hirofumi; Takase, Keizou [CSK Co. Ltd., Tokyo (Japan)

2001-01-01

The methods how diagnostics data are treated as the surface quantity of magnetic surface and processed to the profile data in the JT-60U plasmas are summarized. The MHD equilibrium obtained by solving Grad-Shafranov equation on the MHD equilibrium calculation and registration software FBEQU are saved shot by shot as a database. Various experimental plasma data measured at various geometrical positions on JT-60 are mapped onto the MHD equilibrium and treated as functions of the volume averaged minor radius {rho} on the experimental data time slice monitoring software SLICE. Experimental data are integrated and edited on SLICE. The experimental data measured as the line integral values are transformed by Able inversion. The mapped data are fitted to a functional form and saved to the profile database MAP-DB. SLICE can also read data from MAP-DB and redisplay and transform them. In addition, SLICE can generate the profile data TOKRD as run data for orbit following Monte-Carlo (OFMC) code, analyzer for current drive consistent with MHD equilibrium (ACCOME) code and tokamak predictive and interpretive code system (TOPICS). (author)

Analyses of plasma parameter profiles in JT-60U

International Nuclear Information System (INIS)

Shirai, Hiroshi; Shimizu, Katsuhiro; Hayashi, Nobuhiko

2001-01-01

The methods how diagnostics data are treated as the surface quantity of magnetic surface and processed to the profile data in the JT-60U plasmas are summarized. The MHD equilibrium obtained by solving Grad-Shafranov equation on the MHD equilibrium calculation and registration software FBEQU are saved shot by shot as a database. Various experimental plasma data measured at various geometrical positions on JT-60 are mapped onto the MHD equilibrium and treated as functions of the volume averaged minor radius ρ on the experimental data time slice monitoring software SLICE. Experimental data are integrated and edited on SLICE. The experimental data measured as the line integral values are transformed by Able inversion. The mapped data are fitted to a functional form and saved to the profile database MAP-DB. SLICE can also read data from MAP-DB and redisplay and transform them. In addition, SLICE can generate the profile data TOKRD as run data for orbit following Monte-Carlo (OFMC) code, analyzer for current drive consistent with MHD equilibrium (ACCOME) code and tokamak predictive and interpretive code system (TOPICS). (author)

Numerical investigation of thermal behaviors in lithium-ion battery stack discharge

International Nuclear Information System (INIS)

Liu, Rui; Chen, Jixin; Xun, Jingzhi; Jiao, Kui; Du, Qing

2014-01-01

Highlights: • The thermal behaviors of a Li-ion battery stack have been investigated by modeling. • Parametric studies have been performed focusing on three different cooling materials. • Effects of discharge rate, ambient temperature and Reynolds number are examined. • General guidelines are proposed for the thermal management of a Li-ion battery stack. - Abstract: Thermal management is critically important to maintain the performance and prolong the lifetime of a lithium-ion (Li-ion) battery. In this paper, a two-dimensional and transient model has been developed for the thermal management of a 20-flat-plate-battery stack, followed by comprehensive numerical simulations to study the influences of ambient temperature, Reynolds number, and discharge rate on the temperature distribution in the stack with different cooling materials. The simulation results indicate that liquid cooling is generally more effective in reducing temperature compared to phase-change material, while the latter can lead to more homogeneous temperature distribution. Fast and deep discharge should be avoided, which generally yields high temperature beyond the acceptable range regardless of cooling materials. At low or even subzero ambient temperatures, air cooling is preferred over liquid cooling because heat needs to be retained rather than removed. Such difference becomes small when the ambient temperature increases to a mild level. The effects of Reynolds number are apparent in liquid cooling but negligible in air cooling. Choosing appropriate cooling material and strategy is particularly important in low ambient temperature and fast discharge cases. These findings improve the understanding of battery stack thermal behaviors and provide the general guidelines for thermal management system. The present model can also be used in developing control system to optimize battery stack thermal behaviors

Analysis of stacking overlap in nucleic acid structures: algorithm and application.

Science.gov (United States)

Pingali, Pavan Kumar; Halder, Sukanya; Mukherjee, Debasish; Basu, Sankar; Banerjee, Rahul; Choudhury, Devapriya; Bhattacharyya, Dhananjay

2014-08-01

RNA contains different secondary structural motifs like pseudo-helices, hairpin loops, internal loops, etc. in addition to anti-parallel double helices and random coils. The secondary structures are mainly stabilized by base-pairing and stacking interactions between the planar aromatic bases. The hydrogen bonding strength and geometries of base pairs are characterized by six intra-base pair parameters. Similarly, stacking can be represented by six local doublet parameters. These dinucleotide step parameters can describe the quality of stacking between Watson-Crick base pairs very effectively. However, it is quite difficult to understand the stacking pattern for dinucleotides consisting of non canonical base pairs from these parameters. Stacking interaction is a manifestation of the interaction between two aromatic bases or base pairs and thus can be estimated best by the overlap area between the planar aromatic moieties. We have calculated base pair overlap between two consecutive base pairs as the buried van der Waals surface between them. In general, overlap values show normal distribution for the Watson-Crick base pairs in most double helices within a range from 45 to 50 Å(2) irrespective of base sequence. The dinucleotide steps with non-canonical base pairs also are seen to have high overlap value, although their twist and few other parameters are rather unusual. We have analyzed hairpin loops of different length, bulges within double helical structures and pseudo-continuous helices using our algorithm. The overlap area analyses indicate good stacking between few looped out bases especially in GNRA tetraloop, which was difficult to quantitatively characterise from analysis of the base pair or dinucleotide step parameters. This parameter is also seen to be capable to distinguish pseudo-continuous helices from kinked helix junctions.

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

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.

Industrial stacks design; Diseno de chimeneas industriales

Energy Technology Data Exchange (ETDEWEB)

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

1987-12-31

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.

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.

Computerized method and system for designing an aerodynamic focusing lens stack

Science.gov (United States)

Gard, Eric [San Francisco, CA; Riot, Vincent [Oakland, CA; Coffee, Keith [Diablo Grande, CA; Woods, Bruce [Livermore, CA; Tobias, Herbert [Kensington, CA; Birch, Jim [Albany, CA; Weisgraber, Todd [Brentwood, CA

2011-11-22

A computerized method and system for designing an aerodynamic focusing lens stack, using input from a designer related to, for example, particle size range to be considered, characteristics of the gas to be flowed through the system, the upstream temperature and pressure at the top of a first focusing lens, the flow rate through the aerodynamic focusing lens stack equivalent at atmosphere pressure; and a Stokes number range. Based on the design parameters, the method and system determines the total number of focusing lenses and their respective orifice diameters required to focus the particle size range to be considered, by first calculating for the orifice diameter of the first focusing lens in the Stokes formula, and then using that value to determine, in iterative fashion, intermediate flow values which are themselves used to determine the orifice diameters of each succeeding focusing lens in the stack design, with the results being output to a designer. In addition, the Reynolds numbers associated with each focusing lens as well as exit nozzle size may also be determined to enhance the stack design.

Stacking machine learning classifiers to identify Higgs bosons at the LHC

International Nuclear Information System (INIS)

Alves, A.

2017-01-01

Machine learning (ML) algorithms have been employed in the problem of classifying signal and background events with high accuracy in particle physics. In this paper, we compare the performance of a widespread ML technique, namely, stacked generalization , against the results of two state-of-art algorithms: (1) a deep neural network (DNN) in the task of discovering a new neutral Higgs boson and (2) a scalable machine learning system for tree boosting, in the Standard Model Higgs to tau leptons channel, both at the 8 TeV LHC. In a cut-and-count analysis, stacking three algorithms performed around 16% worse than DNN but demanding far less computation efforts, however, the same stacking outperforms boosted decision trees. Using the stacked classifiers in a multivariate statistical analysis (MVA), on the other hand, significantly enhances the statistical significance compared to cut-and-count in both Higgs processes, suggesting that combining an ensemble of simpler and faster ML algorithms with MVA tools is a better approach than building a complex state-of-art algorithm for cut-and-count.

Scalable microbial fuel cell (MFC) stack for continuous real wastewater treatment.

Science.gov (United States)

Zhuang, Li; Zheng, Yu; Zhou, Shungui; Yuan, Yong; Yuan, Haoran; Chen, Yong

2012-02-01

A tubular air-cathode microbial fuel cell (MFC) stack with high scalability and low material cost was constructed and the ability of simultaneous real wastewater treatment and bioelectricity generation was investigated under continuous flow mode. At the two organic loading rates (ORLs) tested (1.2 and 4.9kg COD/m(3)d), five non-Pt MFCs connected in series and parallel circuit modes treating swine wastewater can enable an increase of the voltage and the current. The parallel stack retained high power output and the series connection underwent energy loss due to the substrate cross-conduction effect. With continuous electricity production, the parallel stack achieved 83.8% of COD removal and 90.8% of NH(4)(+)-N removal at 1.2kg COD/m(3)d, and 77.1% COD removal and 80.7% NH(4)(+)-N removal at 4.9kg COD/m(3)d. The MFC stack system in this study was demonstrated to be able to treat real wastewater with the added benefit of harvesting electricity energy. Copyright © 2011 Elsevier Ltd. All rights reserved.

Stacking multiple connecting functional materials in tandem organic light-emitting diodes

Science.gov (United States)

Zhang, Tao; Wang, Deng-Ke; Jiang, Nan; Lu, Zheng-Hong

2017-02-01

Tandem device is an important architecture in fabricating high performance organic light-emitting diodes and organic photovoltaic cells. The key element in making a high performance tandem device is the connecting materials stack, which plays an important role in electric field distribution, charge generation and charge injection. For a tandem organic light-emitting diode (OLED) with a simple Liq/Al/MoO3 stack, we discovered that there is a significant current lateral spreading causing light emission over an extremely large area outside the OLED pixel when the Al thickness exceeds 2 nm. This spread light emission, caused by an inductive electric field over one of the device unit, limits one’s ability to fabricate high performance tandem devices. To resolve this issue, a new connecting materials stack with a C60 fullerene buffer layer is reported. This new structure permits optimization of the Al metal layer in the connecting stack and thus enables us to fabricate an efficient tandem OLED having a high 155.6 cd/A current efficiency and a low roll-off (or droop) in current efficiency.

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...

Prediction of residual stress distribution in multi-stacked thin film by curvature measurement and iterative FEA

International Nuclear Information System (INIS)

Choi, Hyeon Chang; Park, Jun Hyub

2005-01-01

In this study, residual stress distribution in multi-stacked film by MEMS (Micro-Electro Mechanical System) process is predicted using Finite Element Method (FEM). We develop a finite element program for REsidual Stress Analysis (RESA) in multi-stacked film. The RESA predicts the distribution of residual stress field in multi-stacked film. Curvatures of multi-stacked film and single layers which consist of the multi-stacked film are used as the input to the RESA. To measure those curvatures is easier than to measure a distribution of residual stress. To verify the RESA, mean stresses and stress gradients of single and multilayers are measured. The mean stresses are calculated from curvatures of deposited wafer by using Stoney's equation. The stress gradients are calculated from the vertical deflection at the end of cantilever beam. To measure the mean stress of each layer in multi-stacked film, we measure the curvature of wafer with the film after etching layer by layer in multi-stacked film

Predicting and mapping soil available water capacity in Korea.

Science.gov (United States)

Hong, Suk Young; Minasny, Budiman; Han, Kyung Hwa; Kim, Yihyun; Lee, Kyungdo

2013-01-01

The knowledge on the spatial distribution of soil available water capacity at a regional or national extent is essential, as soil water capacity is a component of the water and energy balances in the terrestrial ecosystem. It controls the evapotranspiration rate, and has a major impact on climate. This paper demonstrates a protocol for mapping soil available water capacity in South Korea at a fine scale using data available from surveys. The procedures combined digital soil mapping technology with the available soil map of 1:25,000. We used the modal profile data from the Taxonomical Classification of Korean Soils. The data consist of profile description along with physical and chemical analysis for the modal profiles of the 380 soil series. However not all soil samples have measured bulk density and water content at -10 and -1500 kPa. Thus they need to be predicted using pedotransfer functions. Furthermore, water content at -10 kPa was measured using ground samples. Thus a correction factor is derived to take into account the effect of bulk density. Results showed that Andisols has the highest mean water storage capacity, followed by Entisols and Inceptisols which have loamy texture. The lowest water retention is Entisols which are dominated by sandy materials. Profile available water capacity to a depth of 1 m was calculated and mapped for Korea. The western part of the country shows higher available water capacity than the eastern part which is mountainous and has shallower soils. The highest water storage capacity soils are the Ultisols and Alfisols (mean of 206 and 205 mm, respectively). Validation of the maps showed promising results. The map produced can be used as an indication of soil physical quality of Korean soils.

Predicting and mapping soil available water capacity in Korea

Directory of Open Access Journals (Sweden)

Suk Young Hong

2013-04-01

Full Text Available The knowledge on the spatial distribution of soil available water capacity at a regional or national extent is essential, as soil water capacity is a component of the water and energy balances in the terrestrial ecosystem. It controls the evapotranspiration rate, and has a major impact on climate. This paper demonstrates a protocol for mapping soil available water capacity in South Korea at a fine scale using data available from surveys. The procedures combined digital soil mapping technology with the available soil map of 1:25,000. We used the modal profile data from the Taxonomical Classification of Korean Soils. The data consist of profile description along with physical and chemical analysis for the modal profiles of the 380 soil series. However not all soil samples have measured bulk density and water content at −10 and −1500 kPa. Thus they need to be predicted using pedotransfer functions. Furthermore, water content at −10 kPa was measured using ground samples. Thus a correction factor is derived to take into account the effect of bulk density. Results showed that Andisols has the highest mean water storage capacity, followed by Entisols and Inceptisols which have loamy texture. The lowest water retention is Entisols which are dominated by sandy materials. Profile available water capacity to a depth of 1 m was calculated and mapped for Korea. The western part of the country shows higher available water capacity than the eastern part which is mountainous and has shallower soils. The highest water storage capacity soils are the Ultisols and Alfisols (mean of 206 and 205 mm, respectively. Validation of the maps showed promising results. The map produced can be used as an indication of soil physical quality of Korean soils.

Stack and area tritium monitoring systems for the tokamak fusion test reactor (TFTR)

International Nuclear Information System (INIS)

Pearson, G.G.; Meixler, L.D.; Sirsingh, R.A.P.

1992-01-01

This paper reports on the TFTR Tritium Stack and Area Monitoring Systems which have been developed to provide the required level of reliability in a cost effective manner consistent with the mission of the Tritium Handling System on TFTR. Personnel protection, environmental responsibility, and tritium containing system integrity have been the considerations in system design. During the Deuterium-Tritium (D-T) experiments on TFTR, tritium will be used for the first time as one of the fuels. Area monitors provide surveillance of the air in various rooms at TFTR. Stack monitors monitor the air at the TFTR test site that is exhausted through the HVAC systems, from the room exhaust stacks and the tritium systems process vents. The philosophies for the implementation of the Stack and Area Tritium Monitoring Systems at TFTR are to use hardwired controls wherever personnel protection is involved, and to take advantage of modern intelligent controllers to provide a distributed system to support the functions of tracking, displaying, and archiving concentration levels of tritium for all of the monitored areas and stacks

Effect of Additional Structure on Effective Stack Height of Gas Dispersion in Atmosphere

Directory of Open Access Journals (Sweden)

Takenobu Michioka

2016-03-01

Full Text Available Wind-tunnel experiments were conducted to evaluate the effect of additional structure (building, sea wall and banking on the effective stack height, which is usually used in safety analyses of nuclear power facilities in Japan. The effective stack heights were estimated with and without the additional structure in addition to the reactor building while varying several conditions such as the source height, the height of additional structure and the distance between the source position and the additional structure. When the source height is equivalent to the reactor building height, the additional structure enhances both the vertical and horizontal gas dispersion widths and decreases the ground gas concentration, and it means that the additional structure does not decrease the effective stack height. When the source height is larger than the reactor height, the additional structures might affect the effective stack height. As the distance between the source and the additional structure decreases, or as the height of the additional structure increases, the structure has a larger effect on the effective stack height.

Fabrication of a Cu/Ni stack in supercritical carbon dioxide at low-temperature

Energy Technology Data Exchange (ETDEWEB)

Rasadujjaman, Md, E-mail: rasadphy@duet.ac.bd [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan); Department of Physics, Dhaka University of Engineering & Technology, Gazipur 1700 (Bangladesh); Watanabe, Mitsuhiro [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan); Sudoh, Hiroshi; Machida, Hideaki [Gas-Phase Growth Ltd., 2-24-16 Naka, Koganei, Tokyo 184-0012 (Japan); Kondoh, Eiichi [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan)

2015-09-30

We report the low-temperature deposition of Cu on a Ni-lined substrate in supercritical carbon dioxide. A novel Cu(I) amidinate precursor was used to reduce the deposition temperature. From the temperature dependence of the growth rate, the activation energy for Cu growth on the Ni film was determined to be 0.19 eV. The films and interfaces were characterized by Auger electron spectroscopy. At low temperature (140 °C), we successfully deposited a Cu/Ni stack with a sharp Cu/Ni interface. The stack had a high adhesion strength (> 1000 mN) according to microscratch testing. The high adhesion strength originated from strong interfacial bonding between the Cu and the Ni. However, at a higher temperature (240 °C), significant interdiffusion was observed and the adhesion became weak. - Highlights: • Cu/Ni stack fabricated in supercritical CO{sub 2} at low temperature. • A novel Cu(I) amidinate precursor was used to reduce the deposition temperature. • Adhesion strength of Cu/Ni stack improved dramatically. • Fabricated Cu/Ni stack is suitable for Cu interconnections in microelectronics.

Lens proteome map and alpha-crystallin profile of the catfish Rita rita.

Science.gov (United States)

Mohanty, Bimal Prasanna; Bhattacharjee, Soma; Das, Manas Kumar

2011-02-01

Crystallins are a diverse group of proteins that constitute nearly 90% of the total soluble proteins of the vertebrate eye lens and these tightly packed crystallins are responsible for transparency of the lens. These proteins have been studied in different model and non-model species for understanding the modifications they undergo with ageing that lead to cataract, a disease of protein aggregation. In the present investigation, we studied the lens crystallin profile of the tropical freshwater catfish Rita rita. Profiles of lens crystallins were analyzed and crystallin proteome maps of Rita rita were generated for the first time. alphaA-crystallins, member of the alpha-crystallin family, which are molecular chaperons and play crucial role in maintaining lens transparency were identified by 1- and 2-D immunoblot analysis with anti-alphaA-crystallin antibody. Two protein bands of 19-20 kDa were identified as alphaA-crystallins on 1-D immunoblots and these bands separated into 10 discrete spots on 2-D immunoblot. However, anti-alphaB-crystallin and antiphospho-alphaB-crystallin antibodies were not able to detect any immunoreactive bands on 1- and 2-D immunoblots, indicating alphaB-crystallin was either absent or present in extremely low concentration in Rita rita lens. Thus, Rita rita alpha-crystallins are more like that of the catfish Clarias batrachus and the mammal kangaroo in its alphaA- and alphaB-crystallin content (contain low amount from 5-9% of alphaB-crystallin) and unlike the dogfish, zebrafish, human, bovine and mouse alpha-crystallins (contain higher amount of alphaB-crystallin from 25% in mouse and bovine to 85% in dogfish). Results of the present study can be the baseline information for stimulating further investigation on Rita rita lens crystallins for comparative lens proteomics. Comparing and contrasting the alpha-crystallins of the dogfish and Rita rita may provide valuable information on the functional attributes of alphaA- and alphaB-isoforms, as

Optimal Stack Layout in a Sea Container Terminal with Automated Lifting Vehicles

NARCIS (Netherlands)

D. Roy (Debjit); A. Gupta (Akash); S. Parhi (Sampanna); M.B.M. de Koster (René)

2014-01-01

textabstractContainer terminal performance is largely determined by its design decisions, which include the number and type of quay cranes (QCs), stack cranes (SCs), transport vehicles, vehicle travel path, and stack layout. The terminal design process is complex because it is affected by factors

A cross-stacked plasmonic nanowire network for high-contrast femtosecond optical switching.

Science.gov (United States)

Lin, Yuanhai; Zhang, Xinping; Fang, Xiaohui; Liang, Shuyan

2016-01-21

We report an ultrafast optical switching device constructed by stacking two layers of gold nanowires into a perpendicularly crossed network, which works at a speed faster than 280 fs with an on/off modulation depth of about 22.4%. The two stacks play different roles in enhancing consistently the optical switching performance due to their different dependence on the polarization of optical electric fields. The cross-plasmon resonance based on the interaction between the perpendicularly stacked gold nanowires and its Fano-coupling with Rayleigh anomaly is the dominant mechanism for such a high-contrast optical switching device.

Research and Development of Fully Automatic Alien Smoke Stack and Packaging System

Science.gov (United States)

Yang, Xudong; Ge, Qingkuan; Peng, Tao; Zuo, Ping; Dong, Weifu

2017-12-01

The problem of low efficiency of manual sorting packaging for the current tobacco distribution center, which developed a set of safe efficient and automatic type of alien smoke stack and packaging system. The functions of fully automatic alien smoke stack and packaging system adopt PLC control technology, servo control technology, robot technology, image recognition technology and human-computer interaction technology. The characteristics, principles, control process and key technology of the system are discussed in detail. Through the installation and commissioning fully automatic alien smoke stack and packaging system has a good performance and has completed the requirements for shaped cigarette.

MBARI Mapping AUV: A High-Resolution Deep Ocean Seafloor Mapping Capability

Science.gov (United States)

Caress, D. W.; Kirkwood, W. J.; Thomas, H.; McEwen, R.; Henthorn, R.; McGill, P.; Thompson, D.; Sibenac, M.; Jensen, S.; Shane, F.; Hamilton, A.

2005-05-01

The Monterey Bay Aquarium Research Institute (MBARI) is developing an autonomous seafloor mapping capability for deep ocean science applications. The MBARI Mapping AUV is a 0.53 m (21 in) diameter, 5.1 m (16.7 ft) long, Dorado-class vehicle designed to carry four mapping sonars. The primary sensor is a 200 kHz multibeam sonar producing swath bathymetry and sidescan. In addition, the vehicle carries 100 kHz and 410 kHz chirp sidescan sonars, and a 2-16 kHz sweep chirp subbottom profiler. Navigation and attitude data are obtained from an inertial navigation system (INS) incorporating a ring laser gyro and a 300 kHz Doppler velocity log (DVL). The vehicle also includes acoustic modem, ultra-short baseline navigation, and long-baseline navigation systems. The Mapping AUV is powered by 6 kWhr of Li-polymer batteries, providing expected mission duration of 12 hours at a typical speed of 1.5 m/s. All components of the vehicle are rated to 6000 m depth, allowing MBARI to conduct high-resolution mapping of the deep-ocean seafloor. The sonar package is also be mountable on ROV Ventana, allowing surveys at altitudes less than 20 m at topographically challenging sites. The vehicle was assembled and extensively tested during 2004; this year we are commencing operations for MBARI science projects while continuing the process of testing and integrating the complete suite of sensors and systems. MBARI is beginning to use this capability to observe the changing morphology of dynamic systems such as submarine canyons and active slumps, to map deep-water benthic habitats at resolutions comparable to ROV and submersible observations, to provide basemaps for ROV dives, and to provide high resolution bathymetry and subbottom profiles as part of a variety of projects requiring knowledge of the seafloor. We will present initial results from surveys in and around Monterey Canyon, including high resolution repeat surveys of four sites along the canyon axis.

Design and experimental characterization of a 350 W High Temperature PEM fuel cell stack

Directory of Open Access Journals (Sweden)

Nicola Zuliani

2011-01-01

Full Text Available High Temperature Proton Exchange Membrane (HT PEM fuel cell based on polybenzimidazole (PBI polymer and phosphoric acid, can be operated at temperature between 120 °C and 180 °C. Reactants humidification is not required and CO content up to 2% in the fuel can be tolerated, affecting only marginally performance. This is what makes HT PEM very attractive, as low quality reformed hydrogen can be used and water management problems are avoided. Till nowadays, from experimental point of view, only few studies relate to the development and characterization of high temperature stacks. The aim of this work is to present the main design features and the performance curves of a 25 cells HT PEM stack based on PBI and phosphoric acid membranes. Performance curves refer to the stack operating with two type of fuels: pure hydrogen and a gas mixture simulating a typical steam reformer output. The stack voltage distribution analysis and the stack temperature distribution analysis suggest that cathode air could be used as coolant leading to a better thermal management. This could simplify stack design and system BOP, thus increasing system performance.

Development of HT-PEMFC components and stack for CHP unit

Energy Technology Data Exchange (ETDEWEB)

Jensen, Jens Oluf; Li, Q. (Technical Univ. of Denmark, Dept. of Chemistry, Kgs. Lyngby (Denmark)); Terkelsen, C.; Rudbech, H.C.; Steenberg, T. (Danish Power System Aps, Charlottenlund (Denmark)); Thibault de Rycke (IRD Fuel Cell A/S, Svendborg (Denmark))

2009-10-15

The aim of the project has been to further develop components for an all Danish high temperature PEM fuel cells stack for application in combined heat and power units (CHP units). The final product aimed at was a 1.5-2 kW stack for operation at 150-200 deg. C. The project follows the previous PSO project 4760, 'High Temperature PEM Fuel Cell'. The project has addressed the HT-PEM fuel cells form a components point of view and the materials here for. The main areas were polymer and membrane development, electrode and MEA development (MEA = membrane electrode assembly, i.e. the cells.) and stack development. The membrane development begins with the polymer. The polymerization technique was improved significantly in two ways. Better understanding of the process and the critical issues has led to more reproducible results with repeated high molecular weights. The molecular weight is decisive for the membrane strength and durability. The process was also scaled up to 100-200 g polymer pr. batch in a new polymerization facility build during the project. It is dimensioned for larger batches too, but this was not verified during the project. The polymer cannot be purchased in the right quality for fuel cell membranes and it is important that it manufacture is not a limiting factor at the present state. Experiments with other membrane casting techniques were also made. The traditional PBI doped with phosphoric acid is still the state of art membrane for the HT-PEM fuel cells, but progress was also made with modified membranes. Different variants of PBI were synthesized and tested. Electrodes have been manufactured by a spray technique in contrast to the previously applied tape casting. The hand held spray gun previously led to an improvement of the electrodes, but the reproducibility was limited. Subsequently the construction of a semi automated spray machine was started and results like of the best hand sprayed electrodes were obtained. A viable way of MEA rim

The use of pattern decomposition to study the combined X-ray diffraction effects of crystallite size and stacking faults in ex-oxalate zinc oxide

International Nuclear Information System (INIS)

Langford, J.I.; Boultif, A.; Auffredic, J.P.; Louer, D.

1993-01-01

The microstructure of ZnO powder, obtained from thermal decomposition of the oxalate and studied previously by electron microscopy and adsorption calorimetry, was investigated by means of X-ray powder diffraction pattern decomposition. A Williamson-Hall plot revealed that some lines were broadened solely due to the effects of crystallite size, whereas other breadths included a contribution due to stacking faults. Spherical and cylindrical models are used to describe the form of the crystallites and procedures are presented for separating 'size' effects from 'mistake' broadening. This leads to estimates of the mean dimensions of the crystallites and the stacking-fault probability. The analysis demonstrates that, with good-quality data for a large number of reflections, a considerable amount of detailed information can be obtained about microstructure. On the other hand, it reveals some of the limitations of current procedures for modelling diffraction line profiles. (orig.)

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.

Dynamic Model of the High Temperature Proton Exchange Membrane Fuel Cell Stack Temperature

DEFF Research Database (Denmark)

Andreasen, Søren Juhl; Kær, Søren Knudsen

2009-01-01

The present work involves the development of a model for predicting the dynamic temperature of a high temperature proton exchange membrane (HTPEM) fuel cell stack. The model is developed to test different thermal control strategies before implementing them in the actual system. The test system co...... elements for start-up, heat conduction through stack insulation, cathode air convection, and heating of the inlet gases in the manifold. Various measurements are presented to validate the model predictions of the stack temperatures....

Temperature and flow distribution in planar SOFC stacks

Directory of Open Access Journals (Sweden)

Monica Østenstad

1995-07-01

Full Text Available Simulation of a planar Solid Oxide Fuel Cell stack requires the solution of the mass balances of the chemical species, the energy balances, the charge balance and the channel flow equations in order to compute the species concentrations, the temperature distributions, the current density and the channel flows. The unit cell geometry can be taken into account by combining detailed modeling of a unit cell with a homogenized model of a whole stack. In this study the effect of the asymmetric temperature distribution on the channel flows in a conventional cross-flow design has been investigated. The bidirectional cross-flow design is introduced, for which we can show more directional temperature and flow distributions.

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

Regular control of monitors for effluents from nuclear power plant stacks

International Nuclear Information System (INIS)

Stroem, L.

1979-01-01

The report describes a test procedure for emission monitoring devices for nuclear power plants. The follosing procedures are described, inspection, determination of the air flow through the stack, measurement and adjustment of the flow in the stack loop, measurement and adjustment of flow and density in the measuring loop, calibration of the gas detector, efficiency of sampling of methyliodide and aerosol. (K.K.)

Model and Design of a Power Driver for Piezoelectric Stack Actuators

Directory of Open Access Journals (Sweden)

Chiaberge M

2010-01-01

Full Text Available A power driver has been developed to control piezoelectric stack actuators used in automotive application. An FEM model of the actuator has been implemented starting from experimental characterization of the stack and mechanical and piezoelectric parameters. Experimental results are reported to show a correct piezoelectric actuator driving method and the possibility to obtain a sensorless positioning control.

High Yield Chemical Vapor Deposition Growth of High Quality Large-Area AB Stacked Bilayer Graphene

Science.gov (United States)

Liu, Lixin; Zhou, Hailong; Cheng, Rui; Yu, Woo Jong; Liu, Yuan; Chen, Yu; Shaw, Jonathan; Zhong, Xing; Huang, Yu; Duan, Xiangfeng

2012-01-01

Bernal stacked (AB stacked) bilayer graphene is of significant interest for functional electronic and photonic devices due to the feasibility to continuously tune its band gap with a vertical electrical field. Mechanical exfoliation can be used to produce AB stacked bilayer graphene flakes but typically with the sizes limited to a few micrometers. Chemical vapor deposition (CVD) has been recently explored for the synthesis of bilayer graphene but usually with limited coverage and a mixture of AB and randomly stacked structures. Herein we report a rational approach to produce large-area high quality AB stacked bilayer graphene. We show that the self-limiting effect of graphene growth on Cu foil can be broken by using a high H2/CH4 ratio in a low pressure CVD process to enable the continued growth of bilayer graphene. A high temperature and low pressure nucleation step is found to be critical for the formation of bilayer graphene nuclei with high AB stacking ratio. A rational design of a two-step CVD process is developed for the growth of bilayer graphene with high AB stacking ratio (up to 90 %) and high coverage (up to 99 %). The electrical transport studies demonstrated that devices made of the as-grown bilayer graphene exhibit typical characteristics of AB stacked bilayer graphene with the highest carrier mobility exceeding 4,000 cm2/V·s at room temperature, comparable to that of the exfoliated bilayer graphene. PMID:22906199

Airborne system for mapping and tracking extended gamma ray sources

International Nuclear Information System (INIS)

Stuart, T.P.; Hendricks, T.J.; Wallace, G.G.; Cleland, J.R.

1976-01-01

An airborne system was developed for mapping and tracking extended sources of airborne or terrestrially distributed γ-ray emitters. The system records 300 channel γ-ray spectral data every three seconds on magnetic tape. Computer programs have been written to isolate the contribution from the particular radionuclide of interest. Aircraft position as sensed by a microwave ranging system is recorded every second on magnetic tape. Measurements of airborne stack releases of 41 A concentrations versus time or aircraft position agree well with computer code predictions

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.

Mapping in vivo target interaction profiles of covalent inhibitors using chemical proteomics with label-free quantification.

Science.gov (United States)

van Rooden, Eva J; Florea, Bogdan I; Deng, Hui; Baggelaar, Marc P; van Esbroeck, Annelot C M; Zhou, Juan; Overkleeft, Herman S; van der Stelt, Mario

2018-04-01

Activity-based protein profiling (ABPP) has emerged as a valuable chemical proteomics method to guide the therapeutic development of covalent drugs by assessing their on-target engagement and off-target activity. We recently used ABPP to determine the serine hydrolase interaction landscape of the experimental drug BIA 10-2474, thereby providing a potential explanation for the adverse side effects observed with this compound. ABPP allows mapping of protein interaction landscapes of inhibitors in cells, tissues and animal models. Whereas our previous protocol described quantification of proteasome activity using stable-isotope labeling, this protocol describes the procedures for identifying the in vivo selectivity profile of covalent inhibitors with label-free quantitative proteomics. The optimization of our protocol for label-free quantification methods results in high proteome coverage and allows the comparison of multiple biological samples. We demonstrate our protocol by assessing the protein interaction landscape of the diacylglycerol lipase inhibitor DH376 in mouse brain, liver, kidney and testes. The stages of the protocol include tissue lysis, probe incubation, target enrichment, sample preparation, liquid chromatography-mass spectrometry (LC-MS) measurement, data processing and analysis. This approach can be used to study target engagement in a native proteome and to identify potential off targets for the inhibitor under investigation. The entire protocol takes at least 4 d, depending on the number of samples.

MEAN STACK WEB DEVELOPMENT

OpenAIRE

Le Thanh, Nghi

2017-01-01

The aim of the thesis is to provide a universal website using JavaScript as the main programming language. It also shows the basic parts anyone need to create a web application. The thesis creates a simple CMS using MEAN stack. MEAN is a collection of JavaScript based technologies used to develop web application. It is an acronym for MongoDB, Express, AngularJS and Node.js. It also allows non-technical users to easily update and manage a website’s content. But the application also lets o...

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

Optical transceiver ICs based on 3D die-stacking of opto-electronic devices

NARCIS (Netherlands)

Duan, P.; Raz, O.; Smalbrugge, B.E.; Plassche, van de K.L.; Dorren, H.J.S.

2013-01-01

Wafer scale fabrication of the 3D stacked transceivers is discussed. Uniform open eye patterns at 10 Gb/s/channel of both 3D stacked transmitter and receiver ICs indicates that the interconnection technology is robust.

Calculating transport AC losses in stacks of high temperature superconductor coated conductors with magnetic substrates using FEM

International Nuclear Information System (INIS)

Ainslie, Mark D.; Flack, Tim J.; Campbell, Archie M.

2012-01-01

Properties of stacks of HTS coated conductors with and without a magnetic substrate. Non-magnetic substrate model is consistent with existing methods. Presence of a magnetic substrate increases the total AC loss of the stack. Differences and similarities between certain tapes within stacks are explained. Ferromagnetic loss of substrate negligible in most cases except small currents/fields. In this paper, the authors investigate the electromagnetic properties of stacks of high temperature superconductor (HTS) coated conductors with a particular focus on calculating the total transport AC loss. The cross-section of superconducting cables and coils is often modeled as a two-dimensional stack of coated conductors, and these stacks can be used to estimate the AC loss of a practical device. This paper uses a symmetric two dimensional (2D) finite element model based on the H formulation, and a detailed investigation into the effects of a magnetic substrate on the transport AC loss of a stack is presented. The number of coated conductors in each stack is varied from 1 to 150, and three types of substrate are compared: non-magnetic weakly magnetic and strongly magnetic. The non-magnetic substrate model is comparable with results from existing models for the limiting cases of a single tape (Norris) and an infinite stack (Clem). The presence of a magnetic substrate increases the total AC loss of the stack, due to an increased localized magnetic flux density, and the stronger the magnetic material, the further the flux penetrates into the stack overall. The AC loss is calculated for certain tapes within the stack, and the differences and similarities between the losses throughout the stack are explained using the magnetic flux penetration and current density distributions in those tapes. The ferromagnetic loss of the substrate itself is found to be negligible in most cases, except for small magnitudes of current. Applying these findings to practical applications, where AC

Low-power DRAM-compatible Replacement Gate High-k/Metal Gate Stacks

Science.gov (United States)

Ritzenthaler, R.; Schram, T.; Bury, E.; Spessot, A.; Caillat, C.; Srividya, V.; Sebaai, F.; Mitard, J.; Ragnarsson, L.-Å.; Groeseneken, G.; Horiguchi, N.; Fazan, P.; Thean, A.

2013-06-01

In this work, the possibility of integration of High-k/Metal Gate (HKMG), Replacement Metal Gate (RMG) gate stacks for low power DRAM compatible transistors is studied. First, it is shown that RMG gate stacks used for Logic applications need to be seriously reconsidered, because of the additional anneal(s) needed in a DRAM process. New solutions are therefore developed. A PMOS stack HfO2/TiN with TiN deposited in three times combined with Work Function metal oxidations is demonstrated, featuring a very good Work Function of 4.95 eV. On the other hand, the NMOS side is shown to be a thornier problem to solve: a new solution based on the use of oxidized Ta as a diffusion barrier is proposed, and a HfO2/TiN/TaOX/TiAl/TiN/TiN gate stack featuring an aggressive Work Function of 4.35 eV (allowing a Work Function separation of 600 mV between NMOS and PMOS) is demonstrated. This work paves the way toward the integration of gate-last options for DRAM periphery transistors.

A Simple Semantics and Static Analysis for Stack Inspection

Directory of Open Access Journals (Sweden)

Anindya Banerjee

2013-09-01

Full Text Available The Java virtual machine and the .NET common language runtime feature an access control mechanism specified operationally in terms of run-time stack inspection. We give a denotational semantics in "eager" form, and show that it is equivalent to the "lazy" semantics using stack inspection. We give a static analysis of safety, i.e., the absence of security errors, that is simpler than previous proposals. We identify several program transformations that can be used to remove run-time checks. We give complete, detailed proofs for safety of the analysis and for the transformations, exploiting compositionality of the eager semantics.

Interrelation of Entropic Contributors to π -Stacking in Solution

Science.gov (United States)

Starodub, Maria A.; Lantushenko, Anastasia O.; Evstigneev, Vladislav P.; Golovchenko, Igor V.; Mykhina, Yulia V.; Savin, Valery V.; Evstigneev, Maxim P.

2016-08-01

The recently published most complete set of thermodynamical data on self- and hetero-complexation of aromatic molecules measured under comparable experimental conditions were analyzed. The main aim of this study is to get insights into contribution of various entropic factors to π -stacking in aqueous solution. It was found that the experimental entropy change on π -stacking is determined by counterbalancing effects of two principal factors, i.e., the hydrophobic interaction (positive contribution) and the loss of degrees of freedom (negative contribution) modulated by the electrostatic contribution. Other factors, including the mixing entropy contribution, were shown to be less important.

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.

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.

Modeling shoreface profile evolution

NARCIS (Netherlands)

Stive, M.J.F.; De Vriend, H.J.

1995-01-01

Current knowledge of hydro-, sediment and morpho-dynamics in the shoreface environment is insufficient to undertake shoreface-profile evolution modelling on the basis of first physical principles. We propose a simple, panel-type model to map observed behaviour. The internal dynamics are determined

Modelling shoreface profile evolution

NARCIS (Netherlands)

Stive, Marcel J.F.; de Vriend, Huib J.

1995-01-01

Current knowledge of hydro-, sediment and morpho-dynamics in the shoreface environment is insufficient to undertake shoreface-profile evolution modelling on the basis of first physical principles. We propose a simple, panel-type model to map observed behaviour. The internal dynamics are determined

AIC-based diffraction stacking for local earthquake locations at the Sumatran Fault (Indonesia)

Science.gov (United States)

Hendriyana, Andri; Bauer, Klaus; Muksin, Umar; Weber, Michael

2018-05-01

We present a new workflow for the localization of seismic events which is based on a diffraction stacking approach. In order to address the effects from complex source radiation patterns, we suggest to compute diffraction stacking from a characteristic function (CF) instead of stacking the original waveform data. A new CF, which is called in the following mAIC (modified from Akaike Information Criterion) is proposed. We demonstrate that both P- and S-wave onsets can be detected accurately. To avoid cross-talk between P and S waves due to inaccurate velocity models, we separate the P and S waves from the mAIC function by making use of polarization attributes. Then, the final image function is represented by the largest eigenvalue as a result of the covariance analysis between P- and S-image functions. Results from synthetic experiments show that the proposed diffraction stacking provides reliable results. The workflow of the diffraction stacking method was finally applied to local earthquake data from Sumatra, Indonesia. Recordings from a temporary network of 42 stations deployed for nine months around the Tarutung pull-apart basin were analysed. The seismic event locations resulting from the diffraction stacking method align along a segment of the Sumatran Fault. A more complex distribution of seismicity is imaged within and around the Tarutung basin. Two lineaments striking N-S were found in the centre of the Tarutung basin which support independent results from structural geology.

Spatial walk-off compensated beta-barium borate stack for efficient deep-UV generation

Science.gov (United States)

Li, Da; Lee, Huai-Chuan; Meissner, Stephanie K.; Meissner, Helmuth E.

2018-02-01

Beta-Barium Borate (β-BBO) crystal is commonly used in nonlinear frequency conversion from visible to deep ultraviolet (DUV). However, in a single crystal BBO, its large spatial walk-off effect will reduce spatial overlap of ordinary and extraordinary beam, and thus degrade the conversion efficiency. To overcome the restrictions in current DUV conversion systems, Onyx applies adhesive-free bonding technique to replace the single crystal BBO with a spatial Walk-off Compensated (WOC) BBO stack, which is capable of correcting the spatial walk-off while retaining a constant nonlinear coefficient in the adjacent bonding layers. As a result, the β-BBO stack will provide good beam quality, high conversion efficiency, and broader acceptance angle and spectral linewidth, when compared with a single crystal of BBO. In this work, we report on performance of a spatial walk-off compensated β-BBO stack with adhesive-free bonding technique, for efficiently converting from the visible to DUV range. The physics behind the WOC BBO stack are demonstrated, followed by simulation of DUV conversion efficiency in an external resonance cavity. We also demonstrate experimentally the beam quality improvement in a 4-layer WOC BBO stack over a single BBO crystal.

On the relationship between the irregular reflector and the data processing by stacking; Hanshamen keijo to jugo shori ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Matsushima, J; Yokota, T; Miyazaki, T [Geological Survey of Japan, Tsukuba (Japan); Rokukawa, S [The University of Tokyo, Tokyo (Japan). Faculty of Engineering

1996-05-01

An examination was made on the possibility of data processing by stacking with scattered waves assumed in a seismic exploration analysis (diffraction stacking method). In the examination, a CDP stacking method and the diffraction stacking method were compared through numerical experiments in the case of imaging a flat reflection surface and an irregular reflection surface. As a result, it was revealed that the CDP stacking method for stacking mirror reflection waves was merely a processing to raise S/N ratio while the diffraction stacking method for stacking with scattered waves assumed contained a migrational aspect as well as an aspect to raise S/N ratio. Consequently, it was shown that, if an oscillator was properly arranged, a structural imaging was possible not by the shape of a reflection surface but by the diffraction stacking method. Additionally, the diffraction stacking method revealed that the imaging effect varied by frequency with the stacking effect decreased at high frequencies, and that no stacking effect decreased at low frequencies but resolution lowered in horizontal direction. 4 refs., 8 figs.

Minimizing End-to-End Interference in I/O Stacks Spanning Shared Multi-Level Buffer Caches

Science.gov (United States)

Patrick, Christina M.

2011-01-01

This thesis presents an end-to-end interference minimizing uniquely designed high performance I/O stack that spans multi-level shared buffer cache hierarchies accessing shared I/O servers to deliver a seamless high performance I/O stack. In this thesis, I show that I can build a superior I/O stack which minimizes the inter-application interference…

Nb/NiCu bilayers in single and stacked superconductive tunnel junctions: preliminary results

International Nuclear Information System (INIS)

Pepe, G.P.; Ruotolo, A.; Parlato, L.; Peluso, G.; Ausanio, G.; Carapella, G.; Latempa, R.

2004-01-01

We present preliminary experimental results concerning both single and stacked tunnel junctions in which one of the electrodes was formed by a superconductor/ferromagnet (S/F) bi-layer. In particular, in the stacked configuration a Nb/NiCu bi-layer was used as the intermediate electrode, and it was probed by tunneling on both sides. Tunnel junctions have been characterized in terms of current-voltage characteristics (IVC), and differential conductance. Preliminary steady-state injection-detection measurements performed in the stacked devices at T=4.2 K are also presented and discussed

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

Science.gov (United States)

Lv, Wenping; Wu, Ren'an

2013-03-01

A computational investigation was carried out to understand the aggregation of nanoscale graphene with two typical pathways of stacking assembly and sliding assembly in water. The interfacial-organized monolayer water film (MWF) induced ``two-step'' aggregation of nanographene in both stacking and sliding assembly pathways was reported for the first time. By means of potential mean forces (PMFs) calculation, no energy barrier was observed during the sliding assembly of two graphene nanosheets, while the PMF profiles could be impacted by the contact forms of nanographene and the MWF within the interplate of two graphene nanosheets. To explore the potential physical basis of the ``hindering role'' of self-organized interfacial water, the dynamical and structural properties as well as the status of hydrogen bonds (H-bonds) for interfacial water were investigated. We found that the compact, ordered structure and abundant H-bonds of the MWF could be taken as the fundamental aspects of the ``hindering role'' of interfacial water for the hydrophobic assembly of nanographene. These findings are displaying a potential to further understand the hydrophobic assembly which mostly dominate the behaviors of nanomaterials, proteins etc. in aqueous solutions.A computational investigation was carried out to understand the aggregation of nanoscale graphene with two typical pathways of stacking assembly and sliding assembly in water. The interfacial-organized monolayer water film (MWF) induced ``two-step'' aggregation of nanographene in both stacking and sliding assembly pathways was reported for the first time. By means of potential mean forces (PMFs) calculation, no energy barrier was observed during the sliding assembly of two graphene nanosheets, while the PMF profiles could be impacted by the contact forms of nanographene and the MWF within the interplate of two graphene nanosheets. To explore the potential physical basis of the ``hindering role'' of self-organized interfacial

Okeanos Explorer (EX1504L1): CAPSTONE NWHI Exploration Mapping

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam and singlebeam mapping operations will be conducted 24 hours a day throughout the cruise. Sub-bottom profile mapping will be conducted 24 hours a day at...

Okeanos Explorer (EX1604): CAPSTONE Wake Island PRIMNM (Preliminary Mapping)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam and singlebeam mapping operations will be conducted 24 hours a day throughout the cruise. Sub-bottom profile mapping will be conducted 24 hours a day at...

A mathematical model of an automatic assembler to stack fuel pellets

International Nuclear Information System (INIS)

Jarvis, R.G.; Joynes, R.; Bretzlaff, C.I.

1980-11-01

Fuel elements for CANDU reactors are assembled from stacks of cylindrical UO 2 pellets, with close tolerances on lengths and diameters. Present stacking techniques involve extensive manual operations and they can be speeded up and reduced in cost by an automated device. If gamma-active fuel is handled such a device is essential. An automatic fuel pellet assembly process was modelled mathematically. The model indicated a suitable sequence of pellet manipulations to arrive at a stack length that was always within tolerance. This sequence was used as the inital input for the design of mechanical hardware. The mechanical design and the refinement of the mathematical model proceeded simultaneously. Mechanical constraints were allowed for in the model, and its optimized sequence of operations was incorporated in a microcomputer program to control the mechanical hardware. (auth)

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...

Scaling the CERN OpenStack cloud

Science.gov (United States)

Bell, T.; Bompastor, B.; Bukowiec, S.; Castro Leon, J.; Denis, M. K.; van Eldik, J.; Fermin Lobo, M.; Fernandez Alvarez, L.; Fernandez Rodriguez, D.; Marino, A.; Moreira, B.; Noel, B.; Oulevey, T.; Takase, W.; Wiebalck, A.; Zilli, S.

2015-12-01

CERN has been running a production OpenStack cloud since July 2013 to support physics computing and infrastructure services for the site. In the past year, CERN Cloud Infrastructure has seen a constant increase in nodes, virtual machines, users and projects. This paper will present what has been done in order to make the CERN cloud infrastructure scale out.

High-frequency self-aligned graphene transistors with transferred gate stacks

Science.gov (United States)

Cheng, Rui; Bai, Jingwei; Liao, Lei; Zhou, Hailong; Chen, Yu; Liu, Lixin; Lin, Yung-Chen; Jiang, Shan; Huang, Yu; Duan, Xiangfeng

2012-01-01

Graphene has attracted enormous attention for radio-frequency transistor applications because of its exceptional high carrier mobility, high carrier saturation velocity, and large critical current density. Herein we report a new approach for the scalable fabrication of high-performance graphene transistors with transferred gate stacks. Specifically, arrays of gate stacks are first patterned on a sacrificial substrate, and then transferred onto arbitrary substrates with graphene on top. A self-aligned process, enabled by the unique structure of the transferred gate stacks, is then used to position precisely the source and drain electrodes with minimized access resistance or parasitic capacitance. This process has therefore enabled scalable fabrication of self-aligned graphene transistors with unprecedented performance including a record-high cutoff frequency up to 427 GHz. Our study defines a unique pathway to large-scale fabrication of high-performance graphene transistors, and holds significant potential for future application of graphene-based devices in ultra–high-frequency circuits. PMID:22753503

Isopleths of surface air concentration and surface air kerma rate due to a radioactive cloud released from a stack (3)

International Nuclear Information System (INIS)

Tachibana, Haruo; Kikuchi, Masamitsu; Sekita, Tsutomu; Yamaguchi, Takenori

2004-06-01

This report is a revised edition of 'Isopleths of Surface Air Concentration and Surface Air Absorbed Dose Rate due to a Radioactive Cloud Released from a Stack(II) '(JAERI-M 90-206) and based on the revised Nuclear Safety Guidelines reflected the ICRP1990 Recommendation. Characteristics of this report are the use of Air Karma Rate (Gy/h) instead of Air Absorbed Dose Rate (Gy/h), and the record of isopleths of surface air concentration and surface air karma rate on CD-ROM. These recorded data on CD-ROM can be printed out on paper and/or pasted on digital map by personal computer. (author)

Flow-induced plastic collapse of stacked fuel plates

Energy Technology Data Exchange (ETDEWEB)

Davis, D C; Scarton, H A

1985-03-01

Flow-induced plastic collapse of stacked fuel plate assemblies was first noted in experimental reactors such as the ORNL High Flux Reactor Assembly and the Engineering Test Reactor (ETR). The ETR assembly is a stack of 19 thin flat rectangular fuel plates separated by narrow channels through which a coolant flows to remove the heat generated by fission of the fuel within the plates. The uranium alloyed plates have been noted to buckle laterally and plastically collapse at the system design coolant flow rate of 10.7 m/s, thus restricting the coolant flow through adjacent channels. A methodology and criterion are developed for predicting the plastic collapse of ETR fuel plates. The criterion is compared to some experimental results and the Miller critical velocity theory.

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.

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.

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

Doping profile measurements in silicon using terahertz time domain spectroscopy (THz-TDS) via electrochemical anodic oxidation

Science.gov (United States)

Tulsyan, Gaurav

Doping profiles are engineered to manipulate device properties and to determine electrical performances of microelectronic devices frequently. To support engineering studies afterward, essential information is usually required from physically characterized doping profiles. Secondary Ion Mass Spectrometry (SIMS), Spreading Resistance Profiling (SRP) and Electrochemical Capacitance Voltage (ECV) profiling are standard techniques for now to map profile. SIMS yields a chemical doping profile via ion sputtering process and owns a better resolution, whereas ECV and SRP produce an electrical doping profile detecting free carriers in microelectronic devices. The major difference between electrical and chemical doping profiles is at heavily doped regions greater than 1020 atoms/cm3. At the profile region over the solubility limit, inactive dopants induce a flat plateau and detected by electrical measurements only. Destructive techniques are usually designed as stand-alone systems to study impurities. For an in-situ process control purpose, non-contact methods, such as ellipsometry and non-contact capacitance voltage (CV) techniques are current under development. In this theses work, terahertz time domain spectroscopy (THz-TDS) is utilized to achieve electrical doping profile in both destructive and non-contact manners. In recent years the Terahertz group at Rochester Institute Technology developed several techniques that use terahertz pulses to non-destructively map doping profiles. In this thesis, we study a destructive but potentially higher resolution version of the terahertz based approach to map the profile of activated dopants and augment the non-destructive approaches already developed. The basic idea of the profile mapping approach developed in this MS thesis is to anodize, and thus oxidize to silicon dioxide, thin layers (down to below 10 nm) of the wafer with the doping profile to be mapped. Since the dopants atoms and any free carriers in the silicon oxide thin

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.

The double travelling salesman problem with multiple stacks - Formulation and heuristic solution approaches

DEFF Research Database (Denmark)

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

2009-01-01

This paper introduces the double travelling salesman problem with multiple stacks and presents four different metaheuristic approaches to its solution. The double TSP with multiple stacks is concerned with determining the shortest route performing pickups and deliveries in two separated networks...

Ab-initio calculation of electronic structure and optical properties of AB-stacked bilayer α-graphyne

Science.gov (United States)

Behzad, Somayeh

2016-09-01

Monolayer α-graphyne is a new two-dimensional carbon allotrope with many special features. In this work the electronic properties of AA- and AB-stacked bilayers of this material and then the optical properties are studied, using first principle plane wave method. The electronic spectrum has two Dirac cones for AA stacked bilayer α-graphyne. For AB-stacked bilayer, the interlayer interaction changes the linear bands into parabolic bands. The optical spectra of the most stable AB-stacked bilayer closely resemble to that of the monolayer, except for small shifts of peak positions and increasing of their intensity. For AB-stacked bilayer, a pronounced peak has been found at low energies under the perpendicular polarization. This peak can be clearly ascribed to the transitions at the Dirac point as a result of the small degeneracy lift in the band structure.

Pre-stack estimation of time-lapse seismic velocity changes : an example from the Sleipner CO2-sequestration project

International Nuclear Information System (INIS)

Ghaderi, A.; Landro, M.; Ghaderi, A.

2005-01-01

Carbon dioxide (CO 2 ) is being injected into a shallow sand formation at around a 1,000 metre depth at the Sleipner Field located in the North Sea. It is expected that the CO 2 injected in the bottom of the formation, will form a plume consisting of CO 2 accumulating in thin lenses during migration up through the reservoir. Several studies have been published using stacked seismic data from 1994, 1999, 2001 and 2002. A thorough analysis of post-stack seismic data from the Sleipner CO2-Sequestration Pilot Project was conducted. Interpretation of seismic data is usually done on post-stack data. For a given subsurface reflection point, seismic data are acquired for various incidence angles, typically 40 angles. These 40 seismic signals are stacked together in order to reduce noise. The term pre-stack refers to seismic data prior to this step. For hydrocarbon-related 4-dimensional seismic studies, travel time shift estimations have been used. This paper compared pre-stack and post-stack estimation of average velocity changes based on measured 4-dimensional travel time shifts. It is more practical to compare estimated velocity changes than the actual travel time changes, since the time shifts vary with offset for pre-stack time-lapse seismic analysis. It was concluded that the pre-stack method gives smaller velocity changes when estimated between two key horizons. Therefore, pre-stack travel time analysis in addition to conventional post-stack analysis is recommended. 6 refs., 12 figs

Comparison of source moment tensor recovered by diffraction stacking migration and source time reversal imaging

Science.gov (United States)

Zhang, Q.; Zhang, W.

2017-12-01

Diffraction stacking migration is an automatic location methods and widely used in microseismic monitoring of the hydraulic fracturing. It utilizes the stacking of thousands waveform to enhance signal-to-noise ratio of weak events. For surface monitoring, the diffraction stacking method is suffered from polarity reverse among receivers due to radiation pattern of moment source. Joint determination of location and source mechanism has been proposed to overcome the polarity problem but needs significantly increased computational calculations. As an effective method to recover source moment tensor, time reversal imaging based on wave equation can locate microseismic event by using interferometry on the image to extract source position. However, the time reversal imaging is very time consuming compared to the diffraction stacking location because of wave-equation simulation.In this study, we compare the image from diffraction stacking and time reversal imaging to check if the diffraction stacking can obtain similar moment tensor as time reversal imaging. We found that image produced by taking the largest imaging value at each point along time axis does not exhibit the radiation pattern, while with the same level of calculation efficiency, the image produced for each trial origin time can generate radiation pattern similar to time reversal imaging procedure. Thus it is potential to locate the source position by the diffraction stacking method for general moment tensor sources.

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