WorldWideScience

Sample records for stacked channel-belt complexes

  1. Architecture of channel-belt deposits in an aggrading shallow sandbed braided river: the lower Niobrara River, northeast Nebraska

    Science.gov (United States)

    Skelly, Raymond L.; Bristow, Charlie S.; Ethridge, Frank G.

    2003-05-01

    Architecture of recent channel-belt deposits of the Niobrara River, northeast Nebraska, USA, records the response of a sandy braided river to rapid base-level rise. Up to 3 m of aggradation has occurred within the lower 14 km of the Niobrara River since the mid-1950s as a result of base-level rise at the confluence of the Niobrara and Missouri Rivers. Aerial photographs and channel surveys indicate that the lower Niobrara has evolved from a relatively deep, stable channel with large, bank-attached braid bars to a relatively shallow, aggrading channel with braid bars and smaller secondary channels. Architecture of channel-belt deposits associated with the recent aggradation has been defined using ground-penetrating radar (GPR) and vibracores. The channel-belt deposits exhibit a series of amalgamated channel fills and braid bar complexes (i.e., macroforms). Radar facies identified in the GPR data represent architectural elements of the braid bar complexes, large and small bedforms [two-dimensional (2-D) and three-dimensional (3-D) dunes], and channels. Individual braid bars appear to consist of basal high-flow and upper low-flow components. Preservation of the complete, high-flow bar geometry is generally incomplete due to frequent migration of smaller scale, secondary channels within the channel belt (i.e., braided channel network) at low discharges. The large-scale stratification of the braid bar deposits is dominated by cross-channel and upstream accretion. Elements of downstream accretion are also recognized. These accretion geometries have not been documented previously in similar sandy braided rivers. Braid bar deposits with low-flow modification (e.g., incision by secondary channels) are recognized in the deeper portions of the deposits imaged by GPR. Preservation of braid bars, with both high- and low-flow components, is a result of the rapid base-level rise and channel-bed aggradation experienced by the Niobrara River over the past 45 years. Recent avulsion

  2. Structure of a stacked anthraquinone–DNA complex

    Science.gov (United States)

    De Luchi, Daniela; Usón, Isabel; Wright, Glenford; Gouyette, Catherine; Subirana, Juan A.

    2010-01-01

    The crystal structure of the telomeric sequence d(UBrAGG) interacting with an anthraquinone derivative has been solved by MAD. In all previously studied complexes of intercalating drugs, the drug is usually sandwiched between two DNA base pairs. Instead, the present structure looks like a crystal of stacked anthraquinone molecules in which isolated base pairs are intercalated. Unusual base pairs are present in the structure, such as G·G and A·UBr reverse Watson–Crick base pairs. PMID:20823516

  3. Pre-vegetation fluvial floodplains and channel-belts in the Late Neoproterozoic-Cambrian Santa Bárbara group (Southern Brazil)

    Science.gov (United States)

    Marconato, André; de Almeida, Renato Paes; Turra, Bruno Boito; Fragoso-Cesar, Antônio Romalino dos Santos

    2014-03-01

    One key element to the understanding of the dynamics of pre-vegetation fluvial systems is the reconstruction of processes operating on their floodplains given that, in modern systems, channel banks and floodplains are the environments most affected by plant colonization. Notwithstanding, few pre-vegetation floodplains have been described, and major questions regarding their most basic characteristics are still unresolved. In order to address these questions, detailed analysis of coeval channel-belt, fluvial floodplain and alluvial-fan deposits from the Santa Bárbara Group (Late Neoproterozoic to Early Cambrian, southern Brazil) was performed. While floodplain facies resemble ephemeral stream deposits, being coarser-grained than modern floodplains and marked by the stacking of flood event cycles, channel-belt deposits show composite bars, which do not present conclusive evidence for high water discharge variation. The floodplain deposits show particular features common to other pre-vegetation fluvial systems, such as better preserved small-scale structures, lack of bioturbation, and abundance of cross-laminated sandstones, while other features differ from previous depositional models, namely abundant mudcracks and evidence of soil formation. The lateral variation of depositional systems recorded in the Santa Bárbara Group shows contrasting signatures of water discharge variation in sand-dominated coeval environments, and offers an example of the relation between different alluvial environments before the evolution of land plants.

  4. Stacking of aligned cell sheets for layer-by-layer control of complex tissue structure.

    Science.gov (United States)

    Williams, Corin; Xie, Angela W; Yamato, Masayuki; Okano, Teruo; Wong, Joyce Y

    2011-08-01

    Children suffering from congenital heart defects (CHD) often require vascular reconstruction. Pediatric patients would greatly benefit from a cell-based tissue engineered vascular patch (TEVP) that has potential for growth. As artery structure and function are intimately linked, mimicking native tissue organization is an important design consideration. In this study, we cultured human mesenchymal stem cell on patterned thermo-responsive substrates. Cell alignment improved over time up to 2 wk in culture when sheets were ready for harvest. We then used cell sheets as "functional units" to build complex tissue structures that mimic native vascular smooth muscle cell organization in the medial layer of the artery. Cell sheets could be stacked using a gelatin stamp such that individual sheets in the construct were well aligned with each other (mimic of circumferential orientation) or at angles with respect to each other (mimic of herringbone structure). Controlling tissue organization layer-by-layer will be a powerful approach to building tissues with well defined and complex structure. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Fabrication And Mechanical Properties Of A Nanostructured Complex Aluminum Alloy By Three-Layer Stack Accumulative Roll-Bonding

    OpenAIRE

    Lee S.-H.; Lee S.R.

    2015-01-01

    A multi-layered complex aluminum alloy was successfully fabricated by three-layer stack accumulative roll bonding(ARB) process. The ARB using AA1050 and AA5052 alloy sheets was performed up to 7 cycles at ambient temperature without lubrication. The specimen processed by the ARB showed a multi-layer aluminum alloy sheet in which two aluminum alloys are alternately stacked. The grain size of the specimen decreased with the number of ARB cycles, became about 350nm in diameter after 7cycles. The...

  6. A self-assembled, π-stacked complex as a finely-tunable magnetic aligner for biomolecular NMR applications.

    Science.gov (United States)

    Sato, Sota; Takeuchi, Ryosuke; Yagi-Utsumi, Maho; Yamaguchi, Takumi; Yamaguchi, Yoshiki; Kato, Koichi; Fujita, Makoto

    2015-02-14

    The number of molecules constituting 1D intermolecular aggregates of the π-stacked self-assembled complex was controlled by altering the concentration and temperature. Enhanced magnetic orientation was observed for the aggregates with larger aggregation numbers. It was demonstrated that the designable complex aggregates serve as magnetic aligners to induce magnetic alignment upon an analyte protein coexisting in the solution, resulting in the observation of residual dipolar coupling (RDC) of the analyte.

  7. Formation of stacked luminescent complex of 8-hydroxyquinoline molecules on hydroxyapatite coating by using cold isostatic pressing.

    Science.gov (United States)

    Matsuya, Takehiko; Otsuka, Yuichi; Tagaya, Motohiro; Motozuka, Satoshi; Ohnuma, Kiyoshi; Mutoh, Yoshiharu

    2016-01-01

    Cold isostatic pressing successfully formed a chelate complex of 8-hydroxyquinoline (8 Hq) molecules on plasma-sprayed hydroxyapatite (HAp) coating by solid-state reaction. The complex emits a fluorescence peak at approximately 500 nm by UV irradiation. The red shift of the fluorescence was newly observed in the cases of highly compressed complex due to π - π stacking of aromatic ring in the molecular structure of 8 Hq. The immersed complex coating in Simulated Body Fluid (SBF) demonstrated amorphous apatite precipitation and kept its fluorescence property. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. The Charge-Transfer States in a Stacked Nucleobase Dimer Complex: A Benchmark study

    Czech Academy of Sciences Publication Activity Database

    Aquino, A. J. A.; Nachtigallová, Dana; Hobza, Pavel; Truhlar, D. G.; Hättig, Ch.; Lischka, Hans

    2011-01-01

    Roč. 32, č. 7 (2011), s. 1217-1227 ISSN 0192-8651 R&D Projects: GA MŠk LC512 Grant - others:NSF(US) CHE09-56776 Institutional research plan: CEZ:AV0Z40550506 Keywords : charge transfer * excited states * coupled cluster * DFT * stacked nucleobases Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.583, year: 2011

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-02-28

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

  10. Complex nonequilibrium dynamics of stacked polystyrene films deep in the glassy state

    Science.gov (United States)

    Boucher, Virginie M.; Cangialosi, Daniele; Alegría, Angel; Colmenero, Juan

    2017-05-01

    We investigate the kinetics of enthalpy recovery in stacked glassy polystyrene (PS) films with thickness from 30 to 95 nm over a wide temperature range below the glass transition temperature (Tg). We show that the time evolution toward equilibrium exhibits two mechanisms of recovery, in ways analogous to bulk PS. The fast mechanism, allowing partial enthalpy recovery toward equilibrium, displays Arrhenius temperature dependence with low activation energy, whereas the slow mechanism follows pronounced super-Arrhenius temperature dependence. In comparison to bulk PS, the time scales of the two mechanisms of recovery are considerably shorter and decreasing with the film thickness. Scaling of the equilibration times at various thicknesses indicates that the fast mechanism of recovery is compatible with the free volume holes diffusion model. Conversely, the slow mechanism of recovery appears to be accelerated with decreasing thickness more than predicted by the model and, therefore, its description requires additional ingredients. The implications, from both a fundamental and technological viewpoint, of the ability of thin polymer films to densify in relatively short time scales are discussed.

  11. Paleocene Wilcox cross-shelf channel-belt history and shelf-margin growth: Key to Gulf of Mexico sediment delivery

    Science.gov (United States)

    Zhang, Jinyu; Steel, Ronald; Ambrose, William

    2017-12-01

    Shelf margins prograde and aggrade by the incremental addition of deltaic sediments supplied from river channel belts and by stored shoreline sediment. This paper documents the shelf-edge trajectory and coeval channel belts for a segment of Paleocene Lower Wilcox Group in the northern Gulf of Mexico based on 400 wireline logs and 300 m of whole cores. By quantitatively analyzing these data and comparing them with global databases, we demonstrate how varying sediment supply impacted the Wilcox shelf-margin growth and deep-water sediment dispersal under greenhouse eustatic conditions. The coastal plain to marine topset and uppermost continental slope succession of the Lower Wilcox shelf-margin sediment prism is divided into eighteen high-frequency ( 300 ky duration) stratigraphic sequences, and further grouped into 5 sequence sets (labeled as A-E from bottom to top). Sequence Set A is dominantly muddy slope deposits. The shelf edge of Sequence Sets B and C prograded rapidly (> 10 km/Ma) and aggraded modestly ( 80 m/Ma) characterizes Sequence Sets D and E, which is associated with smaller (9-10 m thick on average) and isolated channel belts. This stratigraphic trend is likely due to an upward decreasing sediment supply indicated by the shelf-edge progradation rate and channel size, as well as an upward increasing shelf accommodation indicated by the shelf-edge aggradation rate. The rapid shelf-edge progradation and large rivers in Sequence Sets B and C confirm earlier suggestions that it was the early phase of Lower Wilcox dispersal that brought the largest deep-water sediment volumes into the Gulf of Mexico. Key factors in this Lower Wilcox stratigraphic trend are likely to have been a very high initial sediment flux to the Gulf because of the high initial release of sediment from Laramide catchments to the north and northwest, possibly aided by modest eustatic sea-level fall on the Texas shelf, which is suggested by the early, flat shelf-edge trajectory, high

  12. Dimensional Control and Morphological Transformations of Supramolecular Polymeric Nanofibers Based on Cofacially-Stacked Planar Amphiphilic Platinum(II) Complexes.

    Science.gov (United States)

    Robinson, Matthew E; Nazemi, Ali; Lunn, David J; Hayward, Dominic W; Boott, Charlotte E; Hsiao, Ming-Siao; Harniman, Robert L; Davis, Sean A; Whittell, George R; Richardson, Robert M; De Cola, Luisa; Manners, Ian

    2017-09-26

    Square-planar platinum(II) complexes often stack cofacially to yield supramolecular fiber-like structures with interesting photophysical properties. However, control over fiber dimensions and the resulting colloidal stability is limited. We report the self-assembly of amphiphilic Pt(II) complexes with solubilizing ancillary ligands based on polyethylene glycol [PEG n , where n = 16, 12, 7]. The complex with the longest solubilizing PEG ligand, Pt-PEG 16 , self-assembled to form polydisperse one-dimensional (1D) nanofibers (diameters fibers of length up to ca. 400 nm. The fiber lengths were dependent on the Pt-PEG 16 complex to seed mass ratio in a manner analogous to a living covalent polymerization of molecular monomers. Moreover, the fiber lengths were unchanged in solution after 1 week and were therefore "static" with respect to interfiber exchange processes on this time scale. In contrast, similarly formed near-uniform fibers of Pt-PEG 12 exhibited dynamic behavior that led to broadening of the length distribution within 48 h. After aging for 4 weeks in solution, Pt-PEG 12 fibers partially evolved into 2D platelets. Furthermore, self-assembly of Pt-PEG 7 yielded only transient fibers which rapidly evolved into 2D platelets. On addition of further fiber-forming Pt complex (Pt-PEG 16 ), the platelets formed assemblies via the growth of fibers selectively from their short edges. Our studies demonstrate that when interfiber dynamic exchange is suppressed, dimensional control and hierarchical structure formation are possible for supramolecular polymers through the use of kinetically controlled seeded growth methods.

  13. Coupled-Mode Theory for Complex-Index, Corrugated Multilayer Stacks

    DEFF Research Database (Denmark)

    Lüder, Hannes; Gerken, Martina; Adam, Jost

    We present a coupled-mode theory (CMT) approach for modelling the modal behaviour of multi- layer thinfilm devices with complex material parameters and periodic corrugations. Our method provides fast computation and extended physical insight as compared to standard numerical methods. Nanostructur....... Express 22, A1363-A1371, 2014 [2] L. T. Neustock et al., Journal of Sensors, ArticleID 6174527, 2016 [3] J. Adam, H. Lüder, and M. Gerken, OWTNM 2015 [4] W.-P. Huang and J. Mu, Opt. Express 17, 19134-19152, 2009...

  14. Algebraic stacks

    Indian Academy of Sciences (India)

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

  15. Mixed-Stack Architecture and Solvatomorphism of Trimeric Perfluoro-ortho-Phenylene Mercury complexes with Dithieno[3,2-b:2',3'-d]thiophene

    KAUST Repository

    Castañeda, Raúl

    2015-08-01

    The formation of the mixed-stack donor-acceptor complex of dithieno[3,2-b:2\\',3\\'-d]thiophene (1) and trimeric perfluoro-ortho-phenylene mercury (I) has been investigated under different conditions. Two solvatomorphs – mixed-stack complexes with a 1:1 donor-acceptor ratio and different solvent molecules in the solid state (dichloromethane (2) and dichloroethane (3)) have been obtained and characterized by experimental methods (FT-IR spectroscopy, differential thermogravimetric analysis, and X-ray crystallography) and quantum-chemical calculations at the density functional theory level. The differences in the solid state packing, thermal stability and potential charge-transfer properties of 2 and 3 are discussed.

  16. A series of Cd(II) complexes with π-π stacking and hydrogen bonding interactions: Structural diversities by varying the ligands

    International Nuclear Information System (INIS)

    Wang Xiuli; Zhang Jinxia; Liu Guocheng; Lin Hongyan

    2011-01-01

    Seven new Cd(II) complexes consisting of different phenanthroline derivatives and organic acid ligands, formulated as [Cd(PIP) 2 (dnba) 2 ] (1), [Cd(PIP)(ox)].H 2 O (2), [Cd(PIP)(1,4-bdc)(H 2 O)].4H 2 O (3), [Cd(3-PIP) 2 (H 2 O) 2 ].4H 2 O (4), [Cd 2 (3-PIP) 4 (4,4'-bpdc)(H 2 O) 2 ].5H 2 O (5), [Cd(3-PIP)(nip)(H 2 O)].H 2 O (6), [Cd 2 (TIP) 4 (4,4'-bpdc)(H 2 O) 2 ].3H 2 O (7) (PIP=2-phenylimidazo[4,5-f]1,10-phenanthroline, 3-PIP=2-(3-pyridyl)imidazo[4,5-f]1,10-phenanthroline, TIP=2-(2-thienyl)imidazo[4,5-f]1,10-phenanthroline, Hdnba=3,5-dinitrobenzoic acid, H 2 ox=oxalic acid, 1,4-H 2 bdc=benzene-1,4-dicarboxylic acid, 4,4'-H 2 bpdc=biphenyl-4,4'-dicarboxylic acid, H 2 nip=5-nitroisophthalic acid) have been synthesized under hydrothermal conditions. Complexes 1 and 4 possess mononuclear structures; complexes 5 and 7 are isostructural and have dinuclear structures; complexes 2 and 3 feature 1D chain structures; complex 6 contains 1D double chain, which are further extended to a 3D supramolecular structure by π-π stacking and hydrogen bonding interactions. The N-donor ligands with extended π-system and organic acid ligands play a crucial role in the formation of the final supramolecular frameworks. Moreover, thermal properties and fluorescence of 1-7 are also investigated. -- Graphical abstract: Seven new supramolecular architectures have been successfully isolated under hydrothermal conditions by reactions of different phen derivatives and Cd(II) salts together with organic carboxylate anions auxiliary ligands. Display Omitted Research highlights: → Complexes 1-7 are 0D or 1D polymeric structure, the π-π stacking and H-bonding interactions extend the complexes into 3D supramolecular network. To our knowledge, systematic study on π-π stacking and H-bonding interactions in cadmium(II) complexes are still limited. → The structural differences among the title complexes indicate the importance of N-donor chelating ligands for the creation of molecular

  17. Enhancement of second hyperpolarizabilities in open-shell singlet slipped-stack dimers composed of square planar nickel complexes involving o-semiquinonato type ligands.

    Science.gov (United States)

    Fukui, Hitoshi; Shigeta, Yasuteru; Nakano, Masayoshi; Kubo, Takashi; Kamada, Kenji; Ohta, Koji; Champagne, Benoît; Botek, Edith

    2011-02-17

    Using the spin-unrestricted hybrid density functional theory method, we have investigated the intermolecular interaction effects on the longitudinal static second hyperpolarizability (γ) of open-shell singlet slipped-stack dimers composed of singlet diradical square planar nickel complexes involving o-semiquinonato type ligands, Ni(o-C(6)H(4)X(2))(2) (where X = O, NH, S, Se, PH). For comparison, we have also examined the γ values of a closed-shell singlet slipped-stack dimer composed of closed-shell monomers Ni[o-C(6)H(4)S(NH(2))](2). It is found that for interplanar distance ranging between 3.0 and 5.0 Å the slipped-stack dimers with intermediate monomer diradical characters exhibit larger γ values per monomer (γ(dimer)/2) than those with large monomer diradical characters or than the closed-shell dimer. These results extend the domain of validity of the relationship found between γ and the diradical character for individual molecules. It also turns out that the ratio R = (γ(dimer)/2)/γ(monomer) increases upon decreasing the interplanar distance and that this increase is larger for intermediate diradical character than for the other cases. These phenomena have been analyzed by considering the γ density distributions of the dimers, demonstrating a significant field-induced third-order charge transfer between the monomers in the case of intermediate diradical character. The present results indicate that open-shell singlet slipped-stack aggregates composed of monomers with intermediate diradical characters constitute another mean for achieving highly efficient and tunable third-order nonlinear optical materials.

  18. Algebraic stacks

    Indian Academy of Sciences (India)

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

  19. Deploying OpenStack

    CERN Document Server

    Pepple, Ken

    2011-01-01

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

  20. 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.

  1. 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.

  2. 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.

  3. Quadratic forms and Clifford algebras on derived stacks

    OpenAIRE

    Vezzosi, Gabriele

    2013-01-01

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

  4. Stacking reactions of the borole complex Cp*Rh(η5-C4H4BPh) with the dicationic fragments [Cp*M]2+ (M = Rh or Ir)

    International Nuclear Information System (INIS)

    Loginov, D.A.; Muratov, D.V.; Starikova, Z.A.; Petrovskij, P.V.; Kudinov, A.R.

    2006-01-01

    The reaction of the (borole)rhodium iodide complex [(η-C 4 H 4 BPh)RhI] 4 with Cp*Li afforded the sandwich compound Cp*Rh(η-C 4 H 4 BPh) (1). The reactions of compound 1 with the solvated complexes [Cp*M(MeNO 2 ) 3 ] 2+ (BF 4 - ) 2 gave triple-decker cationic complexes with the central borole ligand [Cp*Rh(μ-η 5 :η 5 -C 4 H 4 BPh)MCp*] 2+ (BF 4 - ) 2 (M = Rh or Ir). The structure of complex 1 was established by X-ray diffraction [ru

  5. On Stack Reconstruction Problem

    Directory of Open Access Journals (Sweden)

    V. D. Аkeliev

    2009-01-01

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

  6. 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.

  7. po_stack_movie

    DEFF Research Database (Denmark)

    2009-01-01

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

  8. 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.

  9. Energy Expenditure of Sport Stacking

    Science.gov (United States)

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

    2009-01-01

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

  10. 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.

  11. Stack Caching Using Split Data Caches

    DEFF Research Database (Denmark)

    Nielsen, Carsten; Schoeberl, Martin

    2015-01-01

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

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

    Science.gov (United States)

    Silva, Gregory

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

  13. Passive stack ventilation

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-12-31

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

  14. 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.

  15. 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

  16. 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…

  17. HPC Software Stack Testing Framework

    Energy Technology Data Exchange (ETDEWEB)

    2017-07-27

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

  18. 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)

  19. PieceStack: Toward Better Understanding of Stacked Graphs.

    Science.gov (United States)

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

    2016-02-24

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

  20. Ternary complexes metal [Co(II), Ni(II), Cu(II) and Zn(II)]--ortho-iodohippurate (I-hip)--acyclovir. X-ray characterization of isostructural [(Co, Ni or Zn)(I-hip)(2)(ACV)(H(2)O)(3)] with stacking as a recognition factor.

    Science.gov (United States)

    Barceló-Oliver, M; Terrón, A; García-Raso, A; Fiol, J J; Molins, E; Miravitlles, C

    2004-11-01

    Four ternary metal--ortho-iodohippurate (I-hip)--acyclovir (ACV) complexes, [M(I-hip)(2)(ACV)(H(2)O)(3)] where M is Co(II) (1), Ni(II) (2), Cu (3) and Zn(II) have been obtained by reaction between the corresponding binary complexes M(II)(I-hip)(2)xnH(2)O and ACV. Three ternary complexes (M=Co, Ni and Zn) and the corresponding Zn(II)--ortho-iodohippurate binary derivative have been structurally characterized by X-ray diffraction: The studies show these three ternary complexes are isostructural and present, in solid state, an interesting stacking between the nucleobase and the aryl ring of the hippurate moiety, which probably promotes the formation of ternary complexes. Moreover, the two different ligands interact between them by means of ancillary hydrogen bonds with water molecules coordinated to the metal ion. It must be mentioned that these two recognition factors, hydrogen bonds plus stacking, could explain the reason for the isostructurality of these ternary derivatives with so different three metal ions, with diverses trends in coordination numbers and geometries. In solid state, there are two enantiomeric molecules that are related by an inversion center as the crystal-building unit (as a translational motif) for the ternary complexes.

  1. 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...

  2. 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..

  3. Multiple Segmentation of Image Stacks

    DEFF Research Database (Denmark)

    Smets, Jonathan; Jaeger, Manfred

    2014-01-01

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

  4. Simulating Small-Scale Object Stacking Using Stack Stability

    DEFF Research Database (Denmark)

    Kronborg Thomsen, Kasper; Kraus, Martin

    2015-01-01

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

  5. Pressurized electrolysis stack with thermal expansion capability

    Science.gov (United States)

    Bourgeois, Richard Scott

    2015-07-14

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

  6. The Direct FuelCell™ stack engineering

    Science.gov (United States)

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

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

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Development and durability of SOFC stacks

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-12-01

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

  13. 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.

  14. Solid Oxide Fuel Cell Stack Diagnostics

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Barfod, Rasmus Gottrup

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

  15. Studies on complex π-π and T-stacking features of imidazole and phenyl/p-halophenyl units in series of 5-amino-1-(phenyl/p-halophenyl)imidazole-4-carboxamides and their carbonitrile derivatives: Role of halogens in tuning of conformation

    Science.gov (United States)

    Das, Aniruddha

    2017-11-01

    5-amino-1-(phenyl/p-halophenyl)imidazole-4-carboxamides (N-phenyl AICA) (2a-e) and 5-amino-1-(phenyl/p-halophenyl)imidazole-4-carbonitriles (N-phenyl AICN) (3a-e) had been synthesized. X-ray crystallographic studies of 2a-e and 3a-e had been performed to identify any distinct change in stacking patterns in their crystal lattice. Single crystal X-ray diffraction studies of 2a-e revealed π-π stack formations with both imidazole and phenyl/p-halophenyl units in anti and syn parallel-displaced (PD)-type dispositions. No π-π stacking of imidazole occurred when the halogen substituent is bromo or iodo; π-π stacking in these cases occurred involving phenyl rings only. The presence of an additional T-stacking had been observed in crystal lattices of 3a-e. Vertical π-π stacking distances in anti-parallel PD-type arrangements as well as T-stacking distances had shown stacking distances short enough to impart stabilization whereas syn-parallel stacking arrangements had got much larger π-π stacking distances to belie any syn-parallel stacking stabilization. DFT studies had been pursued for quantifying the π-π stacking and T-stacking stabilization. The plotted curves for anti-parallel and T-stacked moieties had similarities to the 'Morse potential energy curve for diatomic molecule'. The minima of the curves corresponded to the most stable stacking distances and related energy values indicated stacking stabilization. Similar DFT studies on syn-parallel systems of 2b corresponded to no π-π stacking stabilization at all. Halogen-halogen interactions had also been observed to stabilize the compounds 2d, 2e and 3d. Nano-structural behaviour of the series of compounds 2a-e and 3a-e were thoroughly investigated.

  16. Geometric Patterns for Neighboring Bases Near the Stacked State in Nucleic Acid Strands.

    Science.gov (United States)

    Sedova, Ada; Banavali, Nilesh K

    2017-03-14

    Structural variation in base stacking has been analyzed frequently in isolated double helical contexts for nucleic acids, but not as often in nonhelical geometries or in complex biomolecular environments. In this study, conformations of two neighboring bases near their stacked state in any environment are comprehensively characterized for single-strand dinucleotide (SSD) nucleic acid crystal structure conformations. An ensemble clustering method is used to identify a reduced set of representative stacking geometries based on pairwise distances between select atoms in consecutive bases, with multiple separable conformational clusters obtained for categories divided by nucleic acid type (DNA/RNA), SSD sequence, stacking face orientation, and the presence or absence of a protein environment. For both DNA and RNA, SSD conformations are observed that are either close to the A-form, or close to the B-form, or intermediate between the two forms, or further away from either form, illustrating the local structural heterogeneity near the stacked state. Among this large variety of distinct conformations, several common stacking patterns are observed between DNA and RNA, and between nucleic acids in isolation or in complex with proteins, suggesting that these might be stable stacking orientations. Noncanonical face/face orientations of the two bases are also observed for neighboring bases in the same strand, but their frequency is much lower, with multiple SSD sequences across categories showing no occurrences of such unusual stacked conformations. The resulting reduced set of stacking geometries is directly useful for stacking-energy comparisons between empirical force fields, prediction of plausible localized variations in single-strand structures near their canonical states, and identification of analogous stacking patterns in newly solved nucleic acid containing structures.

  17. 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.

  18. Generalized data stacking programming model with applications

    Directory of Open Access Journals (Sweden)

    Hala Samir Elhadidy

    2016-09-01

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

  19. 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.)

  20. Hydrogen Embrittlement And Stacking-Fault Energies

    Science.gov (United States)

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

    1988-01-01

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

  1. Extent of Intramolecular pi Stacks in Aqueous Solution in Mixed-Ligand Copper(II) Complexes Formed by Heteroaromatic Amines and 1-[2-(Phosphonomethoxy)ethyl]cytosine (PMEC), a Relative of Antivirally Active Acyclic Nucleotide Analogues (Part 72)

    Czech Academy of Sciences Publication Activity Database

    Blindauer, C. A.; Sigel, A.; Operschall, B. P.; Holý, Antonín; Sigel, H.

    2013-01-01

    Roč. 639, 8-9 (2013), s. 1661-1673 ISSN 0044-2313 Institutional support: RVO:61388963 Keywords : nucleotide analogues * antivirals * complex stabilities * isomers * equilibria * mixed ligand complexes Subject RIV: CC - Organic Chemistry Impact factor: 1.251, year: 2013

  2. Intramolecular .pi.-.pi. stacking interactions in aqueous solution in mixed-ligand copper (II) complexes formed by heteroaromatic amines and the nucleotide analogue (PME2AP), an isomer of the antivirally active (PMEA)

    Czech Academy of Sciences Publication Activity Database

    Fernández-Botello, A.; Holý, Antonín; Moreno, V.; Operschall, B. P.; Sigel, H.

    2009-01-01

    Roč. 362, č. 3 (2009), s. 799-810 ISSN 0020-1693 R&D Projects: GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z40550506 Keywords : antiviral activity * intramolecular equilibria * isomeric complexes * phosphonate complexes Subject RIV: CC - Organic Chemistry Impact factor: 2.322, year: 2009

  3. Stacks of SPS Dipole Magnets

    CERN Multimedia

    1974-01-01

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

  4. California dreaming?[PEM stacks

    Energy Technology Data Exchange (ETDEWEB)

    Crosse, J.

    2002-06-01

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

  5. Stacking technology for a space constrained microsystem

    DEFF Research Database (Denmark)

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

    1998-01-01

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

  6. 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....

  7. 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...

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Intramolecular stacking interactions in ternary copper(II) complexes formed by a heteroaromatic amine and 9-[2-(2-phosphonoethoxy)ethyl]adenine, a relative of the antiviral nucleotide analogue 9-[2-(phosphonomethoxy)ethyl]adenine

    Czech Academy of Sciences Publication Activity Database

    Fernández-Botello, A.; Holý, Antonín; Moreno, V.; Sigel, H.

    2004-01-01

    Roč. 98, - (2004), s. 2114-2124 ISSN 0162-0134 R&D Projects: GA MŠk OC D20.002 Institutional research plan: CEZ:AV0Z4055905 Keywords : adenine nucleotide analogues * intramolecular equilibria * isomeric complexes Subject RIV: CC - Organic Chemistry Impact factor: 2.225, year: 2004

  13. Extent of Intramolecular p-Stacks in Aqueous Solution in Mixed-Ligand Copper(II) Complexes Formed by Heteroaromatic Amines and Several 2-Aminopurine Derivatives of the Antivirally Active Nucleotide Analog 9-[2-(Phosphonomethoxy)ethyl]adenine (PMEA)

    Czech Academy of Sciences Publication Activity Database

    Gómez-Coca, R. B.; Blindauer, C. A.; Sigel, A.; Operschall, B. P.; Holý, Antonín; Sigel, H.

    2012-01-01

    Roč. 9, č. 9 (2012), s. 2008-2034 ISSN 1612-1872 R&D Projects: GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z40550506 Keywords : copper complexes * nucleotides * acyclic nucleoside phosphonates * ANPs * antiviral activity Subject RIV: CE - Biochemistry Impact factor: 1.808, year: 2012

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    Kyoo Nam Choi

    2014-01-01

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

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

    International Nuclear Information System (INIS)

    Fergus, R.W.

    1985-01-01

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

  17. Lithiation-induced shuffling of atomic stacks

    KAUST Repository

    Nie, Anmin

    2014-09-10

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

  18. 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.

  19. Tunable electro-optic filter stack

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-09-05

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

  20. 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.

  1. 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.

  2. Structure of human telomeric RNA (TERRA): stacking of two G-quadruplex blocks in K(+) solution.

    Science.gov (United States)

    Martadinata, Herry; Phan, Anh Tuân

    2013-04-02

    Telomeric repeat-containing RNAs (TERRA) are transcription products of the telomeres. Human TERRA sequences containing UUAGGG repeats can form parallel-stranded G-quadruplexes. The stacking interaction of such structures was shown to be important for ligand targeting and higher-order arrangement of G-quadruplexes in long TERRA sequences. Here we report on the first high-resolution structure of a stacked G-quadruplex formed by the 10-nucleotide human TERRA sequence r(GGGUUAGGGU) in potassium solution. This structure comprises two dimeric three-layer parallel-stranded G-quadruplex blocks, which stack on each other at their 5'-ends. The adenine in each UUA loop is nearly coplanar with the 5'-end G-tetrad forming an A·(G·G·G·G)·A hexad, thereby increasing the stacking contacts between the two blocks. Interestingly, this stacking and loop conformation is different from all structures previously reported for the free human TERRA but resembles the structure previously determined for a complex between a human TERRA sequence and an acridine ligand. This stacking conformation is a potential target for drugs that recognize or induce the stacking interface.

  3. Wearable solar cells by stacking textile electrodes.

    Science.gov (United States)

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

    2014-06-10

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

  4. STACKING FAULT ENERGY IN HIGH MANGANESE ALLOYS

    Directory of Open Access Journals (Sweden)

    Eva Mazancová

    2009-04-01

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

  5. Stack-Based Typed Assembly Language

    National Research Council Canada - National Science Library

    Morrisett, Greg

    1998-01-01

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

  6. 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.

  7. 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.

  8. The motive of the moduli stack of G-bundles over the universal curve

    Indian Academy of Sciences (India)

    E-mail: dvb@math.purdue.edu. MS received 11 April 2007; revised 27 January 2008. Abstract. We define relative motives in the sense of André. After associating a complex in the derived category of motives to an algebraic stack we study this complex in the case of the moduli of G-bundles varying over the moduli of curves.

  9. Alignment of Memory Transfers of a Time-Predictable Stack Cache

    DEFF Research Database (Denmark)

    Abbaspourseyedi, Sahar; Brandner, Florian

    2014-01-01

    of complex cache states. Instead, only the occupancy level of the cache has to be determined. The memory transfers generated by the standard stack cache are not generally aligned. These unaligned accesses risk to introduce complexity to the otherwise simple WCET analysis. In this work, we investigate three...

  10. Stacking for Cosmic Magnetism with SKA Surveys

    OpenAIRE

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

    2015-01-01

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

  11. Environmental Modeling Framework using Stacked Gaussian Processes

    OpenAIRE

    Abdelfatah, Kareem; Bao, Junshu; Terejanu, Gabriel

    2016-01-01

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

  12. Generalized data stacking programming model with applications

    OpenAIRE

    Hala Samir Elhadidy; Rawya Yehia Rizk; Hassen Taher Dorrah

    2016-01-01

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

  13. Representations of stack triangulations in the plane

    OpenAIRE

    Selig, Thomas

    2013-01-01

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

  14. 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...

  15. Detailed Electrochemical Characterisation of Large SOFC Stacks

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  16. 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.

  17. Oxidation behavior of metallic interconnect in solid oxide fuel cell stack

    Science.gov (United States)

    Li, Jun; Zhang, Wenying; Yang, Jiajun; Yan, Dong; Pu, Jian; Chi, Bo; Jian, Li

    2017-06-01

    Oxidation behavior of integrated interconnect with bipolar plate and corrugated sheet made by ferrite steel SUS430 is investigated and compared in simulated environment and in a realistic stack. Electrical current is found to have a direction-related impact on the thickness of the Cr2O3/MnCr2O4 composite oxide scale. Oxide scale of the interconnect aged in the stack exhibits a dual-layered structure of a complex Mn-Cr oxide layer covered by iron oxide. The oxidation rates vary greatly depending on its local environment, with different thermal, electrical density, as well as gas composition conditions. By analyzing the thickness distribution of oxide scale and comparing them with the simulated test result, the oxidation behavior of interconnect in stack is described in high definition. ASR distribution is also conducted by calculation, which could help further understanding the behavior of stack degradation.

  18. Segmentation of RGB-D indoor scenes by stacking random forests and conditional random fields

    DEFF Research Database (Denmark)

    Thøgersen, Mikkel; Guerrero, Sergio Escalera; Gonzàlez, Jordi

    2016-01-01

    on stacked classifiers; the benefits are two fold: on one hand, the system scales well to consider different types of complex features and, on the other hand, the use of stacked classifiers makes the performance of the proposed technique more accurate. The proposed method consists of a random forest using...... a stacked random forest which gives the final predictions. The model is tested on the renown NYU-v2 dataset and the recently available SUNRGBD dataset. The approach shows that simple multimodal features with the power of using multi-class multi-scale stacked sequential learners (MMSSL) can achieve slight...... better performance than state of the art methods on the same dataset. The results show an improvement of 2.3% over the base model by using MMSSL and displays that the method is effective in this problem domain....

  19. Simulation Of Networking Protocols On Software Emulated Network Stack

    Directory of Open Access Journals (Sweden)

    Hrushikesh Nimkar

    2015-08-01

    Full Text Available With the increasing number and complexity of network based applications the need to easy configuration development and integration of network applications has taken a high precedence. Trivial activities such as configuration can be carried out efficiently if network services are software based rather than hardware based. Project aims at enabling the network engineers to easily include network functionalities into hisher configuration and define hisher own network stack without using the kernel network stack. Having thought of this we have implemented two functionalities UPNP and MDNS. The multicast Domain Name System MDNS resolves host names to IP addresses within small ad-hoc networks and without having need of special DNS server and its configuration. MDNS application provides every host with functionality to register itself to the router make a multicast DNS request and its resolution. To make adding network devices and networked programs to a network as easy as it is to plug in a piece of hardware into a PC we make use of UPnP. The devices and programs find out about the network setup and other networked devices and programs through discovery and advertisements of services and configure themselves accordingly. UPNP application provides every host with functionality of discovering services of other hosts and serving requests on demand. To implement these applications we have used snabbswitch framework which an open source virtualized ethernet networking stack.

  20. Performance evaluation of an open-cathode PEM fuel cell stack under ambient conditions: Case study of United Arab Emirates

    International Nuclear Information System (INIS)

    Al-Zeyoudi, Hend; Sasmito, Agus P.; Shamim, Tariq

    2015-01-01

    Highlights: • Performance evaluation of open-cathode PEM fuel cell stacks with forced air-convection. • Stack performance can vary up to 40% from winter to summer. • Hot and arid condition leads to membrane drying and performance deterioration. • Anode humidification improves the stack performance up to 40% during summer. - Abstract: The open-cathode polymer electrolyte membrane (PEM) fuel cell stack has been a promising candidate as a sustainable energy conversion system for replacing fossil fuel-based energy conversion devices in portable and automotive applications. As the ambient air is directly used to provide both oxidant and cooling, the complex cooling loop can be avoided which reduces the complexity and cost. However, the stack performance is highly affected by ambient conditions, i.e., ambient temperature and humidity. In this study, the effect of monthly ambient air conditions (temperature and humidity) is evaluated with respect to the stack’s power production performance as well as thermal, water and gas management by employing a validated three-dimensional open-cathode PEM fuel cell stack model. The annual climate data from the hot and arid environment of Abu Dhabi, United Arab Emirates (UAE) are used as a case study. The objective is to develop a better fundamental understanding of the interactions of physical phenomena in a fuel cell stack, which can assist in improving the performance and operation of an open-cathode PEM fuel cell-powered vehicle. The results indicate that the stack performance can vary significantly (up to 40%) from winter to summer, especially at high operating currents, with significant changes in the stack temperature and the water content at the membrane. Moreover, the anode humidification results in a significant improvement in the stack performance (up to 40%) in hot and dry conditions. However, a careful balance has to be struck between the humidifier parasitic load and the stack power.

  1. From Multi to Single Stack Automata

    Science.gov (United States)

    Atig, Mohamed Faouzi

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

  2. 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...

  3. Stacking fault tetrahedra formation in the neighbourhood of grain boundaries

    CERN Document Server

    Samaras, M; Van Swygenhoven, H; Victoria, M

    2003-01-01

    Large scale molecular dynamics computer simulations are performed to study the role of the grain boundary (GB) during the cascade evolution in irradiated nanocrystalline Ni. At all primary knock-on atom (PKA) energies in cascades near GBs, the damage produced after cooling down is vacancy dominated. Truncated stacking fault tetrahedra (TSFTs) are easily formed at 10 keV and higher PKA energies. At the higher energies a complex partial dislocation network forms, consisting of TSFTs. The GB acts as an interstitial sink without undergoing major structural changes.

  4. Broken sublattice symmetry states in Bernal stacked multilayer graphene

    Science.gov (United States)

    Yoon, Chiho; Jang, Yunsu; Jung, Jeil; Min, Hongki

    2017-06-01

    We analyze the ordered phases of Bernal stacked multilayer graphene in the presence of interaction induced band gaps due to sublattice symmetry breaking potentials, whose solutions can be analyzed in terms of light-mass and heavy-mass pseudospin doublets which have the same Chern numbers but opposite charge polarization directions. The application of a perpendicular external electric field reveals an effective Hund’s rule for the ordering of the sublattice pseudospin doublets in a tetralayer, while a similar but more complex phase diagram develops with increasing layer number.

  5. 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.

  6. Levitation characteristics of HTS tape stacks

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-15

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

  7. 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.

  8. Contemporary sample stacking in analytical electrophoresis.

    Science.gov (United States)

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

    2015-01-01

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

  9. Enhanced dynamical stability with harmonic slip stacking

    Directory of Open Access Journals (Sweden)

    Jeffrey Eldred

    2016-10-01

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

  10. 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.

  11. 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.

  12. Design Handbook for a Stack Foundation

    OpenAIRE

    Tuominen, Vilma

    2011-01-01

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

  13. Simple model of stacking-fault energies

    DEFF Research Database (Denmark)

    Stokbro, Kurt; Jacobsen, Lærke Wedel

    1993-01-01

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

  14. The computational optimization of heat exchange efficiency in stack chimneys

    Energy Technology Data Exchange (ETDEWEB)

    Van Goch, T.A.J.

    2012-02-15

    stack chimney heat exchanger is used for heating or cooling applications, what is the expected performance and how do the design parameters relate to this performance'. Simulation models were developed in the BPS tool ESP-r. The most important design parameters and their relative influence on the performance indicators were analysed based on sensitivity analysis (SA). From this analysis general design guidelines were derived ('optimal set of design parameters'). A multi objective optimization of the design parameters was performed on the simulation models, using the responsive surface methods and artificial neural network capabilities of optimization environment ModEContier to speed up the iteration process. In this optimization, 'heat exchange in stack chimneys is optimized annually'. The uncertainty in the optimized results has been analysed using uncertainty analysis (UA). Finally, the appropriateness of deploying a complex, high resolution simulation has been evaluated by studying current modelling resolution selection methodology found in literature.

  15. 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

  16. 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

  17. Testing of Electrodes, Cells and Short Stacks

    DEFF Research Database (Denmark)

    Hauch, Anne; Mogensen, Mogens Bjerg

    2017-01-01

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

  18. Stack Gas Scrubber Makes the Grade

    Science.gov (United States)

    Chemical and Engineering News, 1975

    1975-01-01

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

  19. 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.

  20. 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 ...

  1. 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

  2. The data type variety of stack algebras

    NARCIS (Netherlands)

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

    1995-01-01

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

  3. 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

  4. 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...

  5. 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...

  6. 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.

  7. Ab initio study of antiphase boundaries and stacking faults in L12 and DO22 compounds

    DEFF Research Database (Denmark)

    Rosengaard, N. M.; Skriver, Hans Lomholt

    1994-01-01

    We have performed ab initio calculations of the energies of antiphase boundaries as well as complex and superlattice intrinsic stacking faults in nine intermetallic compounds observed in the face-centered-cubic L1(2) and DO22 structures. The calculations were performed by means of a Green...

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

    Energy Technology Data Exchange (ETDEWEB)

    TUCK, J.A.

    1998-11-06

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

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

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann

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

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

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann

    2006-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Hou Shu-Yi

    2016-01-01

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

  12. Longitudinal ultrasonic vibration assisted guillotining of stacked paper.

    Science.gov (United States)

    Deibel, Karl-Robert; Kaiser, Fabian; Zimmermann, Remo; Meier, Linus; Bolt, Peter; Wegener, Konrad

    2014-08-01

    Ultrasonic vibration assisted cutting is a complex process with high dynamics. The interaction between cutting tool and workpiece is of key interest to understand the entire process. Experimental investigations are limited by the dynamics of the measurement system, and thus appropriately modeling of the ultrasonic vibration assisted cutting process is essential. In this investigation, a dynamic model regarding the ultrasonic vibration assisted guillotining of stacked paper sheets is developed. A Kelvin-Voigt material model, representing the individual sheets, is chosen, with its stiffness and damping parameters being empirically determined. A novel measurement strategy for studying the contact time and interaction between cutting tool and workpiece is introduced. It allows the verification of the highly dynamic behavior of the developed model. With the dynamic model, the experimentally observed cutting forces can be calculated. It is found that the dynamic forces cause a quicker failure of the material, which leads to a lower compression of the stack prior to reaching the critical cutting force. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Complete intrinsic coincident polarimetry using stacked organic photovoltaics

    Science.gov (United States)

    Gupta Roy, S.; Awartani, O. M.; Sen, P.; O'Connor, B. T.; Kudenov, M. W.

    2015-09-01

    Measuring the 2 dimensional Stokes vector, to determine the polarization state of light, finds application in multiple areas, including the characterization of aerosol size distributions, target identification, quality control by evaluating the distribution of stress birefringence, resolving data channels in telecommunications, and for evaluating biological tissues in medical imaging. Conventional methods, such as channeled and division of focal plane polarimeters, usually limit spatial resolution, while others, like division of aperture or division of amplitude polarimeters, have higher complexity and less compactness. To help solve these issues, we have developed a system that uses semitransparent organic photovoltaics (OPVs) as photodetectors. The active area of the devices consist of biaxially oriented polymer films, which enables the device to preferentially absorb certain polarized states of incident light, depending on the orientation of the polymer chains. Taking advantage of the cells' transparency and ease of processing, compared to inorganic materials, enables multiple devices to be "stacked" along the optical axis. Presently, experiments have been conducted to detect linear polarization states of light. We use three stacked OPVs, where each device can measure one of the first three Stokes parameters simultaneously, thereby ensuring high spatial and temporal resolution with inherent spatial registration. In this paper, the fabrication of the OPVs and the design and calibration technique is documented, along with experimental data, supporting the hypothesis.

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

    African Journals Online (AJOL)

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

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

    OpenAIRE

    Toen, B.

    1999-01-01

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

  16. Learning algorithms for stack filter classifiers

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  17. 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.

  18. Annular feed air breathing fuel cell stack

    Science.gov (United States)

    Wilson, Mahlon S.

    1996-01-01

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

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. CAM and stack air sampler design guide

    International Nuclear Information System (INIS)

    Phillips, T.D.

    1994-01-01

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

  5. Contemporary sample stacking in analytical electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Malá, Zdeňka; Gebauer, Petr; Boček, Petr

    2011-01-01

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

  6. Stacked Switched Capacitor Energy Buffer Architecture

    OpenAIRE

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  8. Thyristor stack for pulsed inductive plasma generation.

    Science.gov (United States)

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

    2009-03-01

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

  9. 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.

  10. 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

  11. 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

  12. Extent of intramolecular pi stacks in aqueous solution in mixed-ligand copper(II) complexes formed by heteroaromatic amines and the anticancer and antivirally active 9[2-(phosphonomethoxy)ethyl]guanine (PMEG). A comparison with related acyclic nucleotide analogues

    Czech Academy of Sciences Publication Activity Database

    Blindauer, C. A.; Sigel, A.; Operschall, B. P.; Griesser, R.; Holý, Antonín; Sigel, H.

    2016-01-01

    Roč. 103, Jan 8 (2016), s. 248-260 ISSN 0277-5387 Institutional support: RVO:61388963 Keywords : anticancer activity * antivirals * aromatic-ring stacking * isomeric equilibria * nucleotide analogues Subject RIV: CC - Organic Chemistry Impact factor: 1.926, year: 2016

  13. Refinement of numerical models and parametric study of SOFC stack performance

    Science.gov (United States)

    Burt, Andrew C.

    The presence of multiple air and fuel channels per fuel cell and the need to combine many cells in series result in complex steady-state temperature distributions within Solid Oxide Fuel Cell (SOFC) stacks. Flow distribution in these channels, when non-uniform, has a significant effect on cell and stack performance. Large SOFC stacks are very difficult to model using full 3-D CFD codes because of the resource requirements needed to solve for the many scales involved. Studies have shown that implementations based on Reduced Order Methods (ROM), if calibrated appropriately, can provide simulations of stacks consisting of more than 20 cells with reasonable computational effort. A pseudo 2-D SOFC stack model capable of studying co-flow and counter-flow cell geometries was developed by solving multiple 1-D SOFC single cell models in parallel on a Beowulf cluster. In order to study cross-flow geometries a novel Multi-Component Multi-Physics (MCMP) scheme was instantiated to produce a Reduced Order 3-D Fuel Cell Model. A C++ implementation of the MCMP scheme developed in this study utilized geometry, control volume, component, and model structures allowing each physical model to be solved only for those components for which it is relevant. Channel flow dynamics were solved using a 1-D flow model to reduce computational effort. A parametric study was conducted to study the influence of mass flow distribution, radiation, and stack size on fuel cell stack performance. Using the pseudo 2-D planar SOFC stack model with stacks of various sizes from 2 to 40 cells it was shown that, with adiabatic wall conditions, the asymmetry of the individual cell can produce a temperature distribution where high and low temperatures are found in the top and bottom cells, respectively. Heat transfer mechanisms such as radiation were found to affect the reduction of the temperature gradient near the top and bottom cell. Results from the reduced order 3-D fuel cell model showed that greater

  14. Improved Direct Methanol Fuel Cell Stack

    Science.gov (United States)

    Wilson, Mahlon S.; Ramsey, John C.

    2005-03-08

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

  15. NSF tandem stack support structure deflection characteristics

    International Nuclear Information System (INIS)

    Cook, J.

    1979-12-01

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

  16. Compliant Glass Seals for SOFC Stacks

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-04-30

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

  17. Effects of combustible stacking in large compartments

    DEFF Research Database (Denmark)

    Gentili, Filippo; Giuliani, Luisa; Bontempi, Franco

    2013-01-01

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

  18. Displacive phase transformations and generalized stacking faults

    Czech Academy of Sciences Publication Activity Database

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2017-07-01

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

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

    Science.gov (United States)

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

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

  1. Stray field interaction of stacked amorphous tapes

    International Nuclear Information System (INIS)

    Guenther, Wulf; Flohrer, Sybille

    2008-01-01

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

  2. Annular feed air breathing fuel cell stack

    Science.gov (United States)

    Wilson, Mahlon S.; Neutzler, Jay K.

    1997-01-01

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

  3. Stacking Analysis of Binary Systems with HAWC

    Science.gov (United States)

    Brisbois, Chad; HAWC Collaboration

    2017-01-01

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

  4. High performance zinc air fuel cell stack

    Science.gov (United States)

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

    2014-03-01

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

  5. 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.

  6. Computerized plutonium laboratory-stack monitoring system

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  7. 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)

  8. 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.

  9. A novel configuration for direct internal reforming stacks

    Science.gov (United States)

    Fellows, Richard

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

  10. Status of Slip Stacking at Fermilab Main Injector

    CERN Document Server

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

    2005-01-01

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

  11. A novel design for solid oxide fuel cell stacks

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-01-01

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

  12. 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.

  13. Post-Stack Seismic Data Enhancement of Thrust-Belt Area, Sabah Basin

    Science.gov (United States)

    Latiff, A. H. Abdul; Jamaludin, S. N. F.; Zakariah, M. N. A.

    2016-02-01

    In this paper, an integrated post-stack seismic data processing and interpretation for a complex thrust-belt area was proposed. The sequence was suggested due to poor seismic data quality of the Sabah basin area that was obtained after a pre-stack data processing sequences. This basin consists of a complex geological setting such as thrust-belt with steep dip reflector which is the main features of the region. In this paper, we outlined several methods used in the seismic data processing and interpretation such as amplitude recovery and frequency filtering for enhancing seismic data quality, and relative acoustic impedance, structural smoothing and wavelet coherency were used for attribute analysis. The outcome from this research aims at illuminating the hidden structures such as proper beds termination and faults systems that was heavily affected by low signal-to-noise ratio.

  14. 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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Data.gov (United States)

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

  17. 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.

  18. Interlayer vacancy defects in AA-stacked bilayer graphene: density functional theory predictions.

    Science.gov (United States)

    Vuong, A; Trevethan, T; Latham, C D; Ewels, C P; Erbahar, D; Briddon, P R; Rayson, M J; Heggie, M I

    2017-04-20

    AA-stacked graphite and closely related structures, where carbon atoms are located in registry in adjacent graphene layers, are a feature of graphitic systems including twisted and folded bilayer graphene, and turbostratic graphite. We present the results of ab initio density functional theory calculations performed to investigate the complexes that are formed from the binding of vacancy defects across neighbouring layers in AA-stacked bilayers. As with AB stacking, the carbon atoms surrounding lattice vacancies can form interlayer structures with sp 2 bonding that are lower in energy than in-plane reconstructions. The sp 2 interlayer bonding of adjacent multivacancy defects in registry creates a type of stable sp 2 bonded 'wormhole' or tunnel defect between the layers. We also identify a new class of 'mezzanine' structure characterised by sp 3 interlayer bonding, resembling a prismatic vacancy loop. The V 6 hexavacancy variant, where six sp 3 carbon atoms sit midway between two carbon layers and bond to both, is substantially more stable than any other vacancy aggregate in AA-stacked layers. Our focus is on vacancy generation and aggregation in the absence of extreme temperatures or intense beams.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-31

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

  20. Interlayer vacancy defects in AA-stacked bilayer graphene: density functional theory predictions

    Science.gov (United States)

    Vuong, A.; Trevethan, T.; Latham, C. D.; Ewels, C. P.; Erbahar, D.; Briddon, P. R.; Rayson, M. J.; Heggie, M. I.

    2017-04-01

    AA-stacked graphite and closely related structures, where carbon atoms are located in registry in adjacent graphene layers, are a feature of graphitic systems including twisted and folded bilayer graphene, and turbostratic graphite. We present the results of ab initio density functional theory calculations performed to investigate the complexes that are formed from the binding of vacancy defects across neighbouring layers in AA-stacked bilayers. As with AB stacking, the carbon atoms surrounding lattice vacancies can form interlayer structures with sp 2 bonding that are lower in energy than in-plane reconstructions. The sp 2 interlayer bonding of adjacent multivacancy defects in registry creates a type of stable sp 2 bonded ‘wormhole’ or tunnel defect between the layers. We also identify a new class of ‘mezzanine’ structure characterised by sp 3 interlayer bonding, resembling a prismatic vacancy loop. The V 6 hexavacancy variant, where six sp 3 carbon atoms sit midway between two carbon layers and bond to both, is substantially more stable than any other vacancy aggregate in AA-stacked layers. Our focus is on vacancy generation and aggregation in the absence of extreme temperatures or intense beams.

  1. 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)

  2. Application of Post-stack migration to seismic data associated with fault structures

    OpenAIRE

    Koduru Anitha; Mohanty P. R

    2015-01-01

    In hydrocarbon exploration, wave-equation migration techniques play an important role in imaging the complex geological structures. Usually, post-stack migration scheme is applied to the seismic data to improve the resolution with restoration of dipping reflectors to their true position. As a result, the migrated time sections are interpretable in terms of subsurface features. As a numerical study, three fault models are considered for the present study. First of all, ...

  3. Manifold seal structure for fuel cell stack

    Science.gov (United States)

    Collins, William P.

    1988-01-01

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

  4. Directive Stacked Patch Antenna for UWB Applications

    Directory of Open Access Journals (Sweden)

    Sharif I. Mitu Sheikh

    2013-01-01

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

  5. ATLAS software stack on ARM64

    Science.gov (United States)

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

    2017-10-01

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

  6. ATLAS software stack on ARM64

    CERN Document Server

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

    2017-01-01

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

  7. Stacked generalization: an introduction to super learning.

    Science.gov (United States)

    Naimi, Ashley I; Balzer, Laura B

    2018-04-10

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

  8. Actuators Using Piezoelectric Stacks and Displacement Enhancers

    Science.gov (United States)

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

    2015-01-01

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

  9. 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.

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

    DEFF Research Database (Denmark)

    Jordan, Alexander; Abbaspourseyedi, Sahar; Schoeberl, Martin

    2016-01-01

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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  12. 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...

  13. High Power, Repetitive, Stacked Blumlein Pulse Generators Commuted by a Single Switching Element

    Science.gov (United States)

    Bhawalkar, Jayant Dilip

    In this work, the stacked Blumlein pulsers developed at the University of Texas at Dallas were characterized and shown to be versatile sources of pulse power for a variety of applications. These devices consisted of several triaxial Blumleins stacked in series at one end. The lines were charged in parallel and synchronously commuted repetitively with a single switching element at the other end. In this way, relatively low charging voltages were multiplied to give a high discharge voltage across an arbitrary load without the need for complex Marx bank circuitry. Several pulser parameters such as the number of stacked Blumlein lines, line configuration, type of switching element, and the length of the lines, were varied and the waveform characteristics were observed and analyzed. It was shown that these devices are capable of generating fast rising waveforms with a wide range of peak voltage and current values. The generation of high power waveforms with pulse durations in the range of 80-600 ns was demonstrated without degradation of the voltage gains. The results of this work indicated that unlike generators based on stacked transmission lines, the effects of parasitic modes were not appreciable for the stacked Blumlein pulsers. Opportunities for tactically packaging these pulsers were also investigated and a significant reduction in their size and weight was demonstrated. For this, dielectric lifetime and Blumlein spacing studies were performed on small scale prototypes. In addition to production of intense X-ray pulses, the possible applications for these novel pulsers include driving magnetrons for high power microwave generation, pumping laser media, or powering e-beam diodes. They could also serve as compact, tabletop sources of high power pulses for various research experiments.

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

    Science.gov (United States)

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

    2017-09-11

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

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

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2007-01-01

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

  16. Direct methanol fuel cell stack based on MEMS technology

    Science.gov (United States)

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

    2008-10-01

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

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

    Science.gov (United States)

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

    2008-09-01

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

  18. Physical Sciences Laboratory 1 Rooftop Stack Mixing Study

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-30

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

  19. Improvement of seismic imaging of complex geologic structures

    Energy Technology Data Exchange (ETDEWEB)

    Duquet, B.

    1996-04-11

    Successful imaging of complex geologic structures by pre-stack depth migration requires a correct velocity model of the subsurface. In recent years, it has been proposed to use pre-stack depth migration of the cube of pre-stack depth migrated images and the subsequent use of the interpretation for velocity model update. However, in complex geologic structures, pre-stack depth migration does not yield results of sufficient quality for interpretation. We therefore propose a new wave-field imaging technique based on linearized inversion using the paraxial approximation of the wave equation. Using this technique we can remove the artifacts contaminating the individual depth images by integrating a priori information in the inverse problem. The application of the method to synthetic and real data shows that it allows us to largely improve the quality of the depth images at reasonable cost.We thus obtain an interpretable cube of depth images that makes migration velocity analysis feasible in complex structures. In 3D, due to the size of the problem there is still a large interest in using post stack techniques for velocity model determination. The quality of the results of such techniques relies on the quality of the stacking process. Classical data stacking techniques rely on simplifications that are not valid anymore in case of complex geologic structures. We propose a data stacking technique based on depth domain stacking after pre-stack depth migration, followed by explosive reflector modeling, to obtain the stacked seismic data. This method which is totally automatic yield 3 D stacked data that are suitable for 3D post stack velocity determination techniques.

  20. 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.

  1. Black Hole Spectroscopy with Coherent Mode Stacking.

    Science.gov (United States)

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

    2017-04-21

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

  2. Stacking faults in austempered ductile iron

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-06-01

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

  3. ATLAS software stack on ARM64

    CERN Document Server

    Smith, Joshua Wyatt; The ATLAS collaboration

    2016-01-01

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

  4. Long Duration Balloon Charge Controller Stack Integration

    Science.gov (United States)

    Clifford, Kyle

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

  5. Weyl magnons in noncoplanar stacked kagome antiferromagnets

    Science.gov (United States)

    Owerre, S. A.

    2018-03-01

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

  6. Large neighborhood search for the double traveling salesman problem with multiple stacks

    Energy Technology Data Exchange (ETDEWEB)

    Bent, Russell W [Los Alamos National Laboratory; Van Hentenryck, Pascal [BROWN UNIV

    2009-01-01

    This paper considers a complex real-life short-haul/long haul pickup and delivery application. The problem can be modeled as double traveling salesman problem (TSP) in which the pickups and the deliveries happen in the first and second TSPs respectively. Moreover, the application features multiple stacks in which the items must be stored and the pickups and deliveries must take place in reserve (LIFO) order for each stack. The goal is to minimize the total travel time satisfying these constraints. This paper presents a large neighborhood search (LNS) algorithm which improves the best-known results on 65% of the available instances and is always within 2% of the best-known solutions.

  7. Investigation of a Superscalar Operand Stack Using FO4 and ASIC Wire-Delay Metrics

    Directory of Open Access Journals (Sweden)

    Christopher Bailey

    2014-01-01

    Full Text Available Complexity in processor microarchitecture and the related issues of power density, hot spots and wire delay, are seen to be a major concern for design migration into low nanometer technologies of the future. This paper evaluates the hardware cost of an alternative to register-file organization, the superscalar stack issue array (SSIA. We believe this is the first such reported study using discrete stack elements. Several possible implementations are evaluated, using a 90 nm standard cell library as a reference model, yielding delay data and FO4 metrics. The evaluation, including reference to ASIC layout, RC extraction, and timing simulation, suggests a 4-wide issue rate of at least four Giga-ops/sec at 90 nm and opportunities for twofold future improvement by using more advanced design approaches.

  8. Charliecloud: Unprivileged containers for user-defined software stacks in HPC

    Energy Technology Data Exchange (ETDEWEB)

    Priedhorsky, Reid [Los Alamos National Laboratory; Randles, Timothy C. [Los Alamos National Laboratory

    2016-08-09

    Supercomputing centers are seeing increasing demand for user-defined software stacks (UDSS), instead of or in addition to the stack provided by the center. These UDSS support user needs such as complex dependencies or build requirements, externally required configurations, portability, and consistency. The challenge for centers is to provide these services in a usable manner while minimizing the risks: security, support burden, missing functionality, and performance. We present Charliecloud, which uses the Linux user and mount namespaces to run industry-standard Docker containers with no privileged operations or daemons on center resources. Our simple approach avoids most security risks while maintaining access to the performance and functionality already on offer, doing so in less than 500 lines of code. Charliecloud promises to bring an industry-standard UDSS user workflow to existing, minimally altered HPC resources.

  9. 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.

  10. 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

  11. 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.

  12. 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.

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

    OpenAIRE

    Bagchi, Bhaskar; Datta, Basudeb

    2012-01-01

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

  14. 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.

  15. 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)

  16. Occurrence and stability of lone pair–π stacking interactions between ribose and nucleobases in functional RNAs

    KAUST Repository

    Chawla, Mohit

    2017-08-18

    The specific folding pattern and function of RNA molecules lies in various weak interactions, in addition to the strong base-base pairing and stacking. One of these relatively weak interactions, characterized by the stacking of the O4′ atom of a ribose on top of the heterocycle ring of a nucleobase, has been known to occur but has largely been ignored in the description of RNA structures. We identified 2015 ribose–base stacking interactions in a high-resolution set of non-redundant RNA crystal structures. They are widespread in structured RNA molecules and are located in structural motifs other than regular stems. Over 50% of them involve an adenine, as we found ribose-adenine contacts to be recurring elements in A-minor motifs. Fewer than 50% of the interactions involve a ribose and a base of neighboring residues, while approximately 30% of them involve a ribose and a nucleobase at least four residues apart. Some of them establish inter-domain or inter-molecular contacts and often implicate functionally relevant nucleotides. In vacuo ribose-nucleobase stacking interaction energies were calculated by quantum mechanics methods. Finally, we found that lone pair–π stacking interactions also occur between ribose and aromatic amino acids in RNA–protein complexes.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  18. 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.

  19. 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.

  20. Static analysis of worst-case stack cache behavior

    DEFF Research Database (Denmark)

    Jordan, Alexander; Brandner, Florian; Schoeberl, Martin

    2013-01-01

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

  1. A Stack Cache for Real-Time Systems

    DEFF Research Database (Denmark)

    Schoeberl, Martin; Nielsen, Carsten

    2016-01-01

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

  2. 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.

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

    Science.gov (United States)

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

    2016-02-24

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

  4. SEE on Different Layers of Stacked-SRAMs

    CERN Document Server

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

    2015-01-01

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

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

    Science.gov (United States)

    2017-09-15

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

  6. 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.

  7. A new method for beam stacking in storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C.M.; /Fermilab

    2008-06-01

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

  8. Stacking faults and phase transformations in silicon nitride

    Science.gov (United States)

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

    1998-11-01

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

  9. 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

  10. 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.

  11. 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.

  12. Standoff Stack Emissions Monitoring Using Short Range Lidar

    Science.gov (United States)

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

    2016-06-01

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

  13. Standoff Stack Emissions Monitoring Using Short Range Lidar

    Directory of Open Access Journals (Sweden)

    Gravel Jean-Francois Y.

    2016-01-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

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

    Science.gov (United States)

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

    2018-02-01

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

  16. Alternative Donor--Acceptor Stacks from Crown Ethers and Naphthalene Diimide Derivatives: Rapid, Selective Formation from Solution and Solid State Grinding

    Energy Technology Data Exchange (ETDEWEB)

    Advanced Light Source; Liu, Yi; Klivansky, Liana; Cao, Dennis; Snauko, Marian; Teat, Simon J.; Struppe, Jochem O.; Koshkakaryan, Gayane

    2009-01-22

    Self assembling {pi}-conjugated molecules into ordered structures are of increasing interest in the field of organic electronics. One particular example is charge transfer complexes containing columnar alternative donor-acceptor (ADA) stacks, where neutral and ionic ground states can be readily tuned to modulate electrical, optical, and ferroelectrical properties. Aromatic-aromatic and charge transfer interactions have been the leading driving forces in assisting the self-assembly of ADA stacks. Various folding structures containing ADA stacks were assembled in solution with the aid of solvophobic or ion-binding interactions. Meanwhile, examples of solid ADA stacks, which are more appealing for practical use in devices, were obtained from cocrystalization of binary components or mesophase assembly of liquid crystals in bulk blends. Regardless of these examples, faster and more controllable approaches towards precise supramolecular order in the solid state are still highly desirable.

  17. Effect of stacking sequence on the coefficients of mutual influence of composite laminates

    Science.gov (United States)

    Dupir (Hudișteanu, I.; Țăranu, N.; Axinte, A.

    2016-11-01

    Fiber reinforced polymeric (FRP) composites are nowadays widely used in engineering applications due to their outstanding features, such as high specific strength and specific stiffness as well as good corrosion resistance. A major advantage of fibrous polymeric composites is that their anisotropy can be controlled through suitable choice of the influencing parameters. The unidirectional fiber reinforced composites provide much higher longitudinal mechanical properties compared to the transverse ones. Therefore, composite laminates are formed by stacking two or more laminas, with different fiber orientations, as to respond to complex states of stresses. These laminates experience the effect of axial-shear coupling, which is caused by applying normal or shear stresses, implying shear or normal strains, respectively. The normal-shear coupling is expressed by the coefficients of mutual influence. They are engineering constants of primary interest for composite laminates, since the mismatch of the material properties between adjacent layers can produce interlaminar stresses and/or plies delamination. The paper presents the variation of the in-plane and flexural coefficients of mutual influence for three types of multi-layered composites, with different stacking sequences. The results are obtained using the Classical Lamination Theory (CLT) and are illustrated graphically in terms of fiber orientations, for asymmetric, antisymmetric and symmetric laminates. Conclusions are formulated on the variation of these coefficients, caused by the stacking sequence.

  18. Application of Post-stack migration to seismic data associated with fault structures

    Science.gov (United States)

    Koduru, Anitha; Mohanty, P. R.

    2015-06-01

    In hydrocarbon exploration, wave-equation migration techniques play an important role in imaging the complex geological structures. Usually, post-stack migration scheme is applied to the seismic data to improve the resolution with restoration of dipping reflectors to their true position. As a result, the migrated time sections are interpretable in terms of subsurface features. As a numerical study, three fault models are considered for the present study. First of all, synthetic time sections are generated corresponding to three models. Later, post stack migration schemes such as Gazdag(PS), Phase-shift with turning rays and reverse time migration (T-K) domain techniques are applied in order to judge the imaging accuracy, preservation of true amplitude and computational speed. All the three post stack time migrated sections delineate the structure with their throw.However, the reverse time migrations (T-K) clearly delineate the reflectors in restoring the throw properly with minimum computational time. In order to test the validity the numerical results, similar exercise has been undertaken using field seismic data of KG basin, India. The results indicates that the field migrated sections are imaged. But, the reverse time migration (T-K ) provides the best subsurface image with restoration of reflectors and collapse of diffracted events with least computational time. Gazdag (PS) and Phase-Shift with turning migrated section shows the reduction of amplitude whereas, the reverse time migration preserved the amplitude fully.

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

    Science.gov (United States)

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

    2014-01-01

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

  20. Stacked Denoising Autoencoders Applied to Star/Galaxy Classification

    Science.gov (United States)

    Qin, Hao-ran; Lin, Ji-ming; Wang, Jun-yi

    2017-04-01

    In recent years, the deep learning algorithm, with the characteristics of strong adaptability, high accuracy, and structural complexity, has become more and more popular, but it has not yet been used in astronomy. In order to solve the problem that the star/galaxy classification accuracy is high for the bright source set, but low for the faint source set of the Sloan Digital Sky Survey (SDSS) data, we introduced the new deep learning algorithm, namely the SDA (stacked denoising autoencoder) neural network and the dropout fine-tuning technique, which can greatly improve the robustness and antinoise performance. We randomly selected respectively the bright source sets and faint source sets from the SDSS DR12 and DR7 data with spectroscopic measurements, and made preprocessing on them. Then, we randomly selected respectively the training sets and testing sets without replacement from the bright source sets and faint source sets. At last, using these training sets we made the training to obtain the SDA models of the bright sources and faint sources in the SDSS DR7 and DR12, respectively. We compared the test result of the SDA model on the DR12 testing set with the test results of the Library for Support Vector Machines (LibSVM), J48 decision tree, Logistic Model Tree (LMT), Support Vector Machine (SVM), Logistic Regression, and Decision Stump algorithm, and compared the test result of the SDA model on the DR7 testing set with the test results of six kinds of decision trees. The experiments show that the SDA has a better classification accuracy than other machine learning algorithms for the faint source sets of DR7 and DR12. Especially, when the completeness function is used as the evaluation index, compared with the decision tree algorithms, the correctness rate of SDA has improved about 15% for the faint source set of SDSS-DR7.

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

    National Research Council Canada - National Science Library

    Lottero, Richard

    2001-01-01

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

  2. Shapes of interacting RNA complexes

    DEFF Research Database (Denmark)

    Fu, Benjamin Mingming; Reidys, Christian

    2014-01-01

    Shapes of interacting RNA complexes are studied using a filtration via their topological genus. A shape of an RNA complex is obtained by (iteratively) collapsing stacks and eliminating hairpin loops.This shape-projection preserves the topological core of the RNA complex and for fixed topological...... genus there are only finitely many such shapes. Our main result is a new bijection that relates the shapes of RNA complexes with shapes of RNA structures. This allows to compute the shape polynomial of RNA complexes via the shape polynomial of RNA structures. We furthermore present a linear time uniform...... sampling algorithm for shapes of RNA complexes of fixed topological genus....

  3. 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.

  4. 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

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

    International Nuclear Information System (INIS)

    Papon, Anne-Marie

    1979-01-01

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

  6. Communication: Thermodynamics of stacking disorder in ice nuclei

    Science.gov (United States)

    Quigley, D.

    2014-09-01

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

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

    Science.gov (United States)

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

    2015-02-01

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

  8. Edge-edge interactions in stacked graphene nanoplatelets

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-01

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

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

    Science.gov (United States)

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

    2015-06-28

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

  10. 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.

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

    International Nuclear Information System (INIS)

    Stroem, L.

    1989-01-01

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

  12. Electric toy vehicle powered by a PEMFC stack

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-15

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

  13. Piezoelectric stack actuator parameter extraction with hysteresis compensation

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. Nuclear fuel rod with retainer for pellet stack

    International Nuclear Information System (INIS)

    Cloue, J.M.

    1986-01-01

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

  20. 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.

  1. Exact Solutions to the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

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

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

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

    Science.gov (United States)

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

    2009-01-01

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

  3. 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.

  4. Second Generation Small Pixel Technology Using Hybrid Bond Stacking

    Science.gov (United States)

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

    2018-01-01

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

  5. Second Generation Small Pixel Technology Using Hybrid Bond Stacking

    OpenAIRE

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

    2018-01-01

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

  6. Second Generation Small Pixel Technology Using Hybrid Bond Stacking

    Directory of Open Access Journals (Sweden)

    Vincent C. Venezia

    2018-02-01

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

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

    Science.gov (United States)

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

    2018-02-24

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

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

    International Nuclear Information System (INIS)

    Guo, Yuzheng; Robertson, John

    2016-01-01

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

  9. Simulation of Collective Excitations in Long Josephson Junction Stacks

    Science.gov (United States)

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

    2018-02-01

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

  10. Spectrally tunable linear polarization rotation using stacked metallic metamaterials

    Science.gov (United States)

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

    2017-08-01

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

  11. 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

  12. Analysis of the Impedance Resonance of Piezoelectric Multi-Fiber Composite Stacks

    Science.gov (United States)

    Sherrit, S.; Djrbashian, A.; Bradford, S C

    2013-01-01

    Multi-Fiber CompositesTM (MFC's) produced by Smart Materials Corp behave essentially like thin planar stacks where each piezoelectric layer is composed of a multitude of fibers. We investigate the suitability of using previously published inversion techniques for the impedance resonances of monolithic co-fired piezoelectric stacks to the MFCTM to determine the complex material constants from the impedance data. The impedance equations examined in this paper are those based on the derivation. The utility of resonance techniques to invert the impedance data to determine the small signal complex material constants are presented for a series of MFC's. The technique was applied to actuators with different geometries and the real coefficients were determined to be similar within changes of the boundary conditions due to change of geometry. The scatter in the imaginary coefficient was found to be larger. The technique was also applied to the same actuator type but manufactured in different batches with some design changes in the non active portion of the actuator and differences in the dielectric and the electromechanical coupling between the two batches were easily measureable. It is interesting to note that strain predicted by small signal impedance analysis is much lower than high field stains. Since the model is based on material properties rather than circuit constants, it could be used for the direct evaluation of specific aging or degradation mechanisms in the actuator as well as batch sorting and adjustment of manufacturing processes.

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

    DEFF Research Database (Denmark)

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

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

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2008-03-28

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

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

    DEFF Research Database (Denmark)

    Carapella, Giovanni; Constabile, Giovanni; Petraglia, Antonio

    1996-01-01

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

  17. Compactifications of reductive groups as moduli stacks of bundles

    DEFF Research Database (Denmark)

    Martens, Johan; Thaddeus, Michael

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

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

    Indian Academy of Sciences (India)

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

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2012-10-16

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

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  2. Tunable infrared plasmonic devices using graphene/insulator stacks

    Science.gov (United States)

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

    2012-05-01

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    Indian Academy of Sciences (India)

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

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

    Indian Academy of Sciences (India)

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

  6. 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)

  7. Thermal entrance effects in a thermoacoustic stacked screen regenerator

    NARCIS (Netherlands)

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

    2014-01-01

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

  8. Proposal of stack Effect technology for predicted future years

    Science.gov (United States)

    Teddy Badai Samodra, FX; Adi Indrawan, Iwan

    2017-12-01

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

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

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

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

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

    NARCIS (Netherlands)

    Grouve, Wouter Johannes Bernardus; Akkerman, Remko

    2010-01-01

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

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

    Indian Academy of Sciences (India)

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

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

    African Journals Online (AJOL)

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

  13. Precise stacking and bonding technology for RDDS structure

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  14. Development and Applications of a Stage Stacking Procedure

    Science.gov (United States)

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

    2012-01-01

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

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

    Science.gov (United States)

    Kablou, Yashar

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

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

    KAUST Repository

    Zhang, Long-li

    2014-07-01

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

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

    Science.gov (United States)

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

    2012-01-01

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

  18. Stability study of pre-stack seismic inversion based on the full Zoeppritz equation

    Science.gov (United States)

    Liang, Lifeng; Zhang, Hongbing; Guo, Qiang; Saeed, Wasif; Shang, Zuoping; Huang, Guojiao

    2017-10-01

    Pre-stack seismic inversion is highly important and complicated. Its result is non-unique, and the process is unstable because pre-stack seismic inversion is an ill-posed problem that simultaneously obtains the results of multiple parameters. Combining the full Zoeppritz equation and additional assumptions with edge-preserving regularization (EPR) can help mitigate the problem. To achieve this combination, we developed an inversion method by constructing a new objective function, which includes the EPR and the Markov random field. The method directly gains reflectivity R PP by the full Zoeppritz equation instead of its approximations and effectively controls the stability of simultaneous inversion by two additional assumptions: the sectional constant V S/V P and the generalized Gardner equation. Thus, the simultaneous inversion of multiple parameters is directed toward to V P, ΔL S (the fitting deviation of V S) and density, and the generalized Gardner equation is regarded as a constraint from which the fitting relationship is derived. We applied the fast simulated annealing algorithm to solve the nonlinear optimization problem. The test results on 2D synthetic data indicated that the stability of simultaneous inversion for V P, ΔL S and density is better than these for V P, V S, and density. The inverted result of density gradually worsens as the deviation ΔL D (the fitting deviation of the density) increases. Moreover, the inverted results were acceptable when using the fitting relationships with error, although they showed varying degrees of influence. We constructed time-varying and space-varying fitting relationships using the logging data in pre-stack inversion of the field seismic data. This improved the inverted results of the simultaneous inversion for complex geological models. Finally, the inverted results of the field data distinctly revealed more detailed information about the layers and matched well with the logging data along the wells over most

  19. Identifying same-cell contours in image stacks: a key step in making 3D reconstructions.

    Science.gov (United States)

    Leung, Tony Kin Shun; Veldhuis, Jim H; Krens, S F Gabby; Heisenberg, C P; Brodland, G Wayne

    2011-02-01

    Identification of contours belonging to the same cell is a crucial step in the analysis of confocal stacks and other image sets in which cell outlines are visible, and it is central to the making of 3D cell reconstructions. When the cells are close packed, the contour grouping problem is more complex than that found in medical imaging, for example, because there are multiple regions of interest, the regions are not separable from each other by an identifiable background and regions cannot be distinguished by intensity differences. Here, we present an algorithm that uses three primary metrics-overlap of contour areas in adjacent images, co-linearity of the centroids of these areas across three images in a stack, and cell taper-to assign cells to groups. Decreasing thresholds are used to successively assign contours whose membership is less obvious. In a final step, remaining contours are assigned to existing groups by setting all thresholds to zero and groups having strong hour-glass shapes are partitioned. When applied to synthetic data from isotropic model aggregates, a curved model epithelium in which the long axes of the cells lie at all possible angles to the transection plane, and a confocal image stack, algorithm assignments were between 97 and 100% accurate in sets having at least four contours per cell. The algorithm is not particularly sensitive to the thresholds used, and a single set of parameters was used for all of the tests. The algorithm, which could be extended to time-lapse data, solves a key problem in the translation of image data into cell information.

  20. 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

  1. Seismic analysis, evaluation and upgrade design for a DOE exhaust stack building

    International Nuclear Information System (INIS)

    Malik, L.E.; Maryak, M.E.

    1991-01-01

    An exhaust stack building of a nuclear reactor facility with complex structural configuration has been analyzed and evaluated and retrofitted for seismic forces. The building was built in the 1950's and had not been designed to resist seismic forces. A rigorous analysis and evaluation program was implemented to minimize costly retrofits required to upgrade the building to resist high seismic forces. Seismic evaluations were performed for the building in its as-is configuration, and as modified for several upgrade schemes. Soil-structure-interaction, basemat flexibility and the influence of the nearby reactor building were considered in rigorous seismic analyses. These analyses and evaluations enabled limited upgrades to qualify the stack building for the seismic forces. Some of the major conclusions of this study are: (1) a phased approach of seismic analyses, utilizing simplified models to evaluate practicable upgrade schemes, and, then incorporating the most suitable scheme in a rigorous model to obtain design forces for upgrades, is an efficient and cost-effective approach for seismic qualification of nuclear facilities to higher seismic criteria; and, (2) finalizing the upgrade of a major nuclear facility is an iterative process, which continues throughout the construction of the upgrades

  2. ENHANCING CLOSE-UP IMAGE BASED 3D DIGITISATION WITH FOCUS STACKING

    Directory of Open Access Journals (Sweden)

    G. Kontogianni

    2017-08-01

    Full Text Available The 3D digitisation of small artefacts is a very complicated procedure because of their complex morphological feature structures, concavities, rich decorations, high frequency of colour changes in texture, increased accuracy requirements etc. Image-based methods present a low cost, fast and effective alternative because laser scanning does not meet the accuracy requirements in general. A shallow Depth of Field (DoF affects the image-based 3D reconstruction and especially the point matching procedure. This is visible not only in the total number of corresponding points but also in the resolution of the produced 3D model. The extension of the DoF is a very important task that should be incorporated in the data collection to attain a better quality of the image set and a better 3D model. An extension of the DoF can be achieved with many methods and especially with the use of the focus stacking technique. In this paper, the focus stacking technique was tested in a real-world experiment to digitise a museum artefact in 3D. The experiment conditions include the use of a full frame camera equipped with a normal lens (50mm, with the camera being placed close to the object. The artefact has already been digitised with a structured light system and that model served as the reference model in which 3D models were compared and the results were presented.

  3. 3D Printing of Plant Golgi Stacks from Their Electron Tomographic Models.

    Science.gov (United States)

    Mai, Keith Ka Ki; Kang, Madison J; Kang, Byung-Ho

    2017-01-01

    Three-dimensional (3D) printing is an effective tool for preparing tangible 3D models from computer visualizations to assist in scientific research and education. With the recent popularization of 3D printing processes, it is now possible for individual laboratories to convert their scientific data into a physical form suitable for presentation or teaching purposes. Electron tomography is an electron microscopy method by which 3D structures of subcellular organelles or macromolecular complexes are determined at nanometer-level resolutions. Electron tomography analyses have revealed the convoluted membrane architectures of Golgi stacks, chloroplasts, and mitochondria. But the intricacy of their 3D organizations is difficult to grasp from tomographic models illustrated on computer screens. Despite the rapid development of 3D printing technologies, production of organelle models based on experimental data with 3D printing has rarely been documented. In this chapter, we present a simple guide to creating 3D prints of electron tomographic models of plant Golgi stacks using the two most accessible 3D printing technologies.

  4. 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.

  5. Stacking metal nano-patterns and fabrication of moth-eye structure

    Science.gov (United States)

    Taniguchi, Jun

    2018-01-01

    Nanoimprint lithography (NIL) can be used as a tool for three-dimensional nanoscale fabrication. In particular, complex metal pattern structures in polymer material are demanded as plasmonic effect devices and metamaterials. To fabricate of metallic color filter, we used silver ink and NIL techniques. Metallic color filter was composed of stacking of nanoscale silver disc patterns and polymer layers, thus, controlling of polymer layer thickness is necessary. To control of thickness of polymer layer, we used spin-coating of UV-curable polymer and NIL. As a result, ten stacking layers with 1000 nm layer thickness was obtained and red color was observed. Ultraviolet nanoimprint lithography (UV-NIL) is the most effective technique for mass fabrication of antireflection structure (ARS) films. For the use of ARS films in mobile phones and tablet PCs, which are touch-screen devices, it is important to protect the films from fingerprints and dust. In addition, as the nanoscale ARS that is touched by the hand is fragile, it is very important to obtain a high abrasion resistance. To solve these problems, a UV-curable epoxy resin has been developed that exhibits antifouling properties and high hardness. The high abrasion resistance ARS films are shown to withstand a load of 250 g/cm2 in the steel wool scratch test, and the reflectance is less than 0.4%.

  6. Nonlinear modelling of polymer electrolyte membrane fuel cell stack using nonlinear cancellation technique

    International Nuclear Information System (INIS)

    Barus, R. P. P.; Tjokronegoro, H. A.; Leksono, E.; Ismunandar

    2014-01-01

    Fuel cells are promising new energy conversion devices that are friendly to the environment. A set of control systems are required in order to operate a fuel cell based power plant system optimally. For the purpose of control system design, an accurate fuel cell stack model in describing the dynamics of the real system is needed. Currently, linear model are widely used for fuel cell stack control purposes, but it has limitations in narrow operation range. While nonlinear models lead to nonlinear control implemnetation whos more complex and hard computing. In this research, nonlinear cancellation technique will be used to transform a nonlinear model into a linear form while maintaining the nonlinear characteristics. The transformation is done by replacing the input of the original model by a certain virtual input that has nonlinear relationship with the original input. Then the equality of the two models is tested by running a series of simulation. Input variation of H2, O2 and H2O as well as disturbance input I (current load) are studied by simulation. The error of comparison between the proposed model and the original nonlinear model are less than 1 %. Thus we can conclude that nonlinear cancellation technique can be used to represent fuel cell nonlinear model in a simple linear form while maintaining the nonlinear characteristics and therefore retain the wide operation range

  7. Impact of Alloying on Stacking Fault Energies in γ-TiAl

    Directory of Open Access Journals (Sweden)

    Phillip Dumitraschkewitz

    2017-11-01

    Full Text Available Microstructure and mechanical properties are key parameters influencing the performance of structural multi-phase alloys such as those based on intermetallic TiAl compounds. There, the main constituent, a γ -TiAl phase, is derived from a face-centered cubic structure. Consequently, the dissociation of dislocations and generation of stacking faults (SFs are important factors contributing to the overall deformation behavior, as well as mechanical properties, such as tensile/creep strength and, most importantly, fracture elongation below the brittle-to-ductile transition temperature. In this work, SFs on the { 111 plane in γ -TiAl are revisited by means of ab initio calculations, finding their energies in agreement with previous reports. Subsequently, stacking fault energies are evaluated for eight ternary additions, namely group IVB–VIB elements, together with Ti off-stoichiometry. It is found that the energies of superlattice intrinsic SFs, anti-phase boundaries (APBs, as well as complex SFs decrease by 20–40% with respect to values in stoichiometric γ -TiAl once an alloying element X is present in the fault plane having thus a composition of Ti-50Al-12.5X. In addition, Mo, Ti and V stabilize the APB on the (111 plane, which is intrinsically unstable at 0 K in stoichiometric γ -TiAl.

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

    Science.gov (United States)

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

    2005-01-01

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

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

    Directory of Open Access Journals (Sweden)

    S. Marchevsky

    1995-04-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  11. 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...

  12. Directly connected series coupled HTPEM fuel cell stacks to a Li-ion battery DC bus for a fuel cell electrical vehicle

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Ashworth, Leanne; Remón, Ian Natanael

    2008-01-01

    The work presented in this paper examines the use of pure hydrogen fuelled high temperature polymer electrolyte membrane (HTPEM) fuel cell stacks in an electrical car, charging a Li-ion battery pack. The car is equipped with two branches of two series coupled 1 kW fuel cell stacks which...... are connected directly parallel to the battery pack during operation. This enables efficient charging of the batteries for increased driving range. With no power electronics used, the fuel cell stacks follow the battery pack voltage, and charge the batteries passively. This saves the electrical and economical...... losses related to these components and their added system complexity. The new car battery pack consists of 23 Li-ion battery cells and the charging and discharging are monitored by a battery management system (BMS) which ensures safe operating conditions for the batteries. The direct connection...

  13. 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.

  14. Radar Target Recognition Based on Stacked Denoising Sparse Autoencoder

    Directory of Open Access Journals (Sweden)

    Zhao Feixiang

    2017-04-01

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

  15. High specific power, direct methanol fuel cell stack

    Science.gov (United States)

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

    2007-05-08

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

  16. Detailed experimental characterization of a reformate fuelled PEM stack

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  17. STACKING ON COMMON REFLECTION SURFACE WITH MULTIPARAMETER TRAVELTIME

    Directory of Open Access Journals (Sweden)

    Montes V. Luis A.

    2006-12-01

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

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

    KAUST Repository

    Klionovski, Kirill

    2017-11-01

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

  19. 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.

  20. Remote Sensing Image Classification Based on Stacked Denoising Autoencoder

    Directory of Open Access Journals (Sweden)

    Peng Liang

    2017-12-01

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

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

    International Nuclear Information System (INIS)

    Pandi, Liliana Yetta; Rohman, Budi

    2003-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ioan URSU

    2016-12-01

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

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

    International Nuclear Information System (INIS)

    Leopando, L.S.

    1994-01-01

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

  4. Review of the stack discharge active particle contamination problem

    Energy Technology Data Exchange (ETDEWEB)

    Parker, H M

    1948-03-22

    Quantities of the order of ten million to 100 million radioactive particles per month were emitted from the stacks over a period of several months. High activity in the range 0.1 to 3..mu..c was probably confined to large carrier particles of corrosion debris from iron ductwork in the separations plant ventilation air system. This report discusses chemical, physical and radiochemical properties of the particles, and possible biological and health effects of exposure to them. (ACR)

  5. Cutting Forces Prediction in the Dry Slotting of Aluminium Stacks

    OpenAIRE

    SALGUERO, Jorge; CALAMAZ, Madalina; BATISTA, Moises; GIROT, Franck; MARCOS, Mariano

    2014-01-01

    International audience; Cutting forces are one of the inherent phenomena and a very significant indicator of themetal cutting process. The work presented in this paper is an investigation of the prediction of these parameters in slotting processes of UNS A92024-T3 (Al-Cu) stacks. So, cutting speed (V) and feed per tooth (fz) based parametric models, for experimental components of cutting force, F(fz,V) have been proposed. These models have been developed from the individual models extracted f...

  6. Availability Analysis of the Ventilation Stack CAM Interlock System

    CERN Document Server

    Young, J

    2000-01-01

    Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies, and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability.

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

    OpenAIRE

    Dorrah, Hassen Taher

    2014-01-01

    This paper presents an elaborated analysis for investigating the stack-based layering processes during the systems change pathway. The system change pathway is defined as the path resulting from the combinations of all successive changes induced on the system when subjected to varying environments, activities, events, or any excessive internal or external influences and happenings “on and above” its normal stands, situations or set-points during its course of life. The analysis is essentially...

  8. Numerical simulations of flux flow in stacked Josephson junctions

    DEFF Research Database (Denmark)

    Madsen, Søren Peder; Pedersen, Niels Falsig

    2005-01-01

    We numerically investigate Josephson vortex flux flow states in stacked Josephson junctions, motivated by recent experiments trying to observe the vortices in a square vortex lattice when a magnetic field is applied to layered high-Tc superconductors of the Bi2Sr2CaCu2Ox type. By extensive...... numerical simulations, we are able to clearly distinguish between triangular and square vortex lattices and to identify the parameters leading to an in-phase vortex configuration....

  9. High Temperature PEM Fuel Cell Stacks with Advent TPS Meas

    Directory of Open Access Journals (Sweden)

    Neophytides Stylianos

    2017-01-01

    Full Text Available High power/high energy applications are expected to greatly benefit from high temperature Polymer Electrolyte Membrane Fuel Cells (PEMFCs. In this work, a combinatorial approach is presented, in which separately developed and evaluated MEAs, design and engineering are employed to result in reliable and effective stacks operating above 180°C and having the characteristics well matched to applications including auxiliary power, micro combined heat and power, and telecommunication satellites.

  10. Parametric Sensitivity Tests- European PEM Fuel Cell Stack Test Procedures

    DEFF Research Database (Denmark)

    Araya, Samuel Simon; Andreasen, Søren Juhl; Kær, Søren Knudsen

    2014-01-01

    performed based on test procedures proposed by a European project, Stack-Test. The sensitivity of a Nafion-based low temperature PEMFC stack’s performance to parametric changes was the main objective of the tests. Four crucial parameters for fuel cell operation were chosen; relative humidity, temperature......, pressure, and stoichiometry at varying current density. Furthermore, procedures for polarization curve recording were also tested both in ascending and descending current directions....

  11. Nature and magnitude of aromatic stacking of nucleic acid bases

    Czech Academy of Sciences Publication Activity Database

    Šponer, Jiří; Riley, K.E.; Hobza, Pavel

    2008-01-01

    Roč. 10, č. 19 (2008), s. 2595-2610 ISSN 1463-9076 R&D Projects: GA AV ČR(CZ) IAA400550510 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702; CEZ:AV0Z40550506 Keywords : quantum chemical calculations * base-stacking * DNA Subject RIV: BO - Biophysics Impact factor: 4.064, year: 2008

  12. Stacking-Based Visualization of Trajectory Attribute Data.

    Science.gov (United States)

    Tominski, C; Schumann, H; Andrienko, G; Andrienko, N

    2012-12-01

    Visualizing trajectory attribute data is challenging because it involves showing the trajectories in their spatio-temporal context as well as the attribute values associated with the individual points of trajectories. Previous work on trajectory visualization addresses selected aspects of this problem, but not all of them. We present a novel approach to visualizing trajectory attribute data. Our solution covers space, time, and attribute values. Based on an analysis of relevant visualization tasks, we designed the visualization solution around the principle of stacking trajectory bands. The core of our approach is a hybrid 2D/3D display. A 2D map serves as a reference for the spatial context, and the trajectories are visualized as stacked 3D trajectory bands along which attribute values are encoded by color. Time is integrated through appropriate ordering of bands and through a dynamic query mechanism that feeds temporally aggregated information to a circular time display. An additional 2D time graph shows temporal information in full detail by stacking 2D trajectory bands. Our solution is equipped with analytical and interactive mechanisms for selecting and ordering of trajectories, and adjusting the color mapping, as well as coordinated highlighting and dedicated 3D navigation. We demonstrate the usefulness of our novel visualization by three examples related to radiation surveillance, traffic analysis, and maritime navigation. User feedback obtained in a small experiment indicates that our hybrid 2D/3D solution can be operated quite well.

  13. Slip-stacking Dynamics and the 20 Hz Booster

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, Jeffery; Zwaska, Robert

    2015-03-01

    Slip-stacking is an accumulation technique used at Fermilab since 2004 which nearly doubles the proton intensity. The Proton Improvement Plan II intensity upgrades require a reduction in slip-stacking losses by approximately a factor of 2. We study the single-particle dynamics that determine the stability of slip-stacking particles. We introduce universal area factors to calculate the available phase space area for any set of beam parameters without individual simulation. We show the particle loss as a function of time. We calculate the injection efficiency as a function of longitudinal emittance and aspect-ratio. We demonstrate that the losses from RF single particle dynamics can be reduced by a factor of 4-10 (depending on beam parameters) by upgrading the Fermilab Booster from a 15-Hz cycle-rate to a 20-Hz cycle-rate. We recommend a change in injection scheme to eliminate the need for a greater momentum aperture in the Fermilab Recycler.

  14. Calculated stacking-fault energies of elemental metals

    DEFF Research Database (Denmark)

    Rosengaard, N. M.; Skriver, Hans Lomholt

    1993-01-01

    We have performed ab initio calculations of twin, intrinsic, and extrinsic face-centered-cubic stacking faults for all the 3d, 4d, and 5d transition metals by means of a Green's-function technique, based on the linear-muffin-tin-orbitals method within the tight-binding and atomic-sphere approxima......We have performed ab initio calculations of twin, intrinsic, and extrinsic face-centered-cubic stacking faults for all the 3d, 4d, and 5d transition metals by means of a Green's-function technique, based on the linear-muffin-tin-orbitals method within the tight-binding and atomic......-sphere approximations. The results are in excellent agreement with recent layer Korringa-Kohn-Rostoker Green's-function calculations where stacking-fault energies for Ni, Cu, Rh, Pd, Ag, Ir, and Au were found by means of the the so-called force theorem. We find that the self-consistent fault energies for all the metals...... on the local atomic coordination are obeyed to a high degree of accuracy....

  15. Nuclear Magnetic Shieldings of Stacked Aromatic and Antiaromatic Molecules.

    Science.gov (United States)

    Sundholm, Dage; Rauhalahti, Markus; Özcan, Nergiz; Mera-Adasme, Raúl; Kussmann, Jörg; Luenser, Arne; Ochsenfeld, Christian

    2017-05-09

    Nuclear magnetic shieldings have been calculated at the density functional theory (DFT) level for stacks of benzene, hexadehydro[12]annulene, dodecadehydro[18]annulene, and hexabenzocoronene. The magnetic shieldings due to the ring currents in the adjacent molecules have been estimated by calculating nucleus independent molecular shieldings for the monomer in the atomic positions of neighbor molecules. The calculations show that the independent shielding model works reasonably well for the 1 H NMR shieldings of benzene and hexadehydro[12]annulene, whereas for the larger molecules and for the 13 C NMR shieldings the interaction between the molecules leads to shielding effects that are at least of the same size as the ring current contributions from the adjacent molecules. A better agreement is obtained when the nearest neighbors are also considered at full quantum mechanical (QM) level. The calculations suggest that the nearest solvent molecules must be included in the quantum mechanical system, at least when estimating solvent shifts at the molecular mechanics (MM) level. Current density calculations show that the stacking does not significantly affect the ring current strengths of the individual molecules, whereas the shape of the ring current for a single molecule differs from that of the stacked molecules.

  16. 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.

  17. Comparison of strain fields in truncated and un-truncated quantum dots in stacked InAs/GaAs nanostructures with varying stacking periods

    CERN Document Server

    Shin, H; Yoo, Y H

    2003-01-01

    Strain fields in truncated and un-truncated InAs quantum dots with the same height and base length have been compared numerically when the dots are vertically stacked in a GaAs matrix at various stacking periods. The compressive hydrostatic strain in truncated dots decreases slightly as compared with the un-truncated dots without regard to the stacking period studied. However, the reduction in tensile biaxial strain, compressive radial strain and tensile axial strain was salient in the truncated dot and the reduction increased with decreasing stacking period. From such changes in strain, changes in the band gap and related properties are anticipated.

  18. Identification of critical parameters for PEMFC stack performance characterization and control strategies for reliable and comparable stack benchmarking

    DEFF Research Database (Denmark)

    Mitzel, Jens; Gülzow, Erich; Kabza, Alexander

    2016-01-01

    This paper is focused on the identification of critical parameters and on the development of reliable methodologies to achieve comparable benchmark results. Possibilities for control sensor positioning and for parameter variation in sensitivity tests are discussed and recommended options for the ......This paper is focused on the identification of critical parameters and on the development of reliable methodologies to achieve comparable benchmark results. Possibilities for control sensor positioning and for parameter variation in sensitivity tests are discussed and recommended options...... in an average cell voltage deviation of 21 mV. Test parameters simulating different stack applications are summarized. The stack demonstrated comparable average cell voltage of 0.63 V for stationary and portable conditions. For automotive conditions, the voltage increased to 0.69 V, mainly caused by higher...

  19. Measurements of the LHCb software stack on the ARM architecture

    International Nuclear Information System (INIS)

    Kartik, S Vijay; Couturier, Ben; Clemencic, Marco; Neufeld, Niko

    2014-01-01

    The ARM architecture is a power-efficient design that is used in most processors in mobile devices all around the world today since they provide reasonable compute performance per watt. The current LHCb software stack is designed (and thus expected) to build and run on machines with the x86/x86 6 4 architecture. This paper outlines the process of measuring the performance of the LHCb software stack on the ARM architecture – specifically, the ARMv7 architecture on Cortex-A9 processors from NVIDIA and on full-fledged ARM servers with chipsets from Calxeda – and makes comparisons with the performance on x86 6 4 architectures on the Intel Xeon L5520/X5650 and AMD Opteron 6272. The paper emphasises the aspects of performance per core with respect to the power drawn by the compute nodes for the given performance – this ensures a fair real-world comparison with much more 'powerful' Intel/AMD processors. The comparisons of these real workloads in the context of LHCb are also complemented with the standard synthetic benchmarks HEPSPEC and Coremark. The pitfalls and solutions for the non-trivial task of porting the source code to build for the ARMv7 instruction set are presented. The specific changes in the build process needed for ARM-specific portions of the software stack are described, to serve as pointers for further attempts taken up by other groups in this direction. Cases where architecture-specific tweaks at the assembler lever (both in ROOT and the LHCb software stack) were needed for a successful compile are detailed – these cases are good indicators of where/how the software stack as well as the build system can be made more portable and multi-arch friendly. The experience gained from the tasks described in this paper are intended to i) assist in making an informed choice about ARM-based server solutions as a feasible low-power alternative to the current compute nodes, and ii) revisit the software design and build system for portability and

  20. 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...

  1. 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.

  2. 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

  3. Stress-induced formation mechanism of stacking fault tetrahedra in nano-cutting of single crystal copper

    International Nuclear Information System (INIS)

    Wang, Quanlong; Bai, Qingshun; Chen, Jiaxuan; Guo, Yongbo; Xie, Wenkun

    2015-01-01

    increase in the initial stage and fluctuates at their equilibrium position at stable cutting stage, which is because of the energy accumulation and release leading to the dislocation emission. A typically stacking fault tetrahedra is nucleated in the subsurface defect layer, which is induced by the complex tension and compression stress. The stress-induced mechanism of stacking fault tetrahedra formation is investigated by atomic scale evolution and local stress distribution.

  4. Relative stabilities and the spectral signatures of stacked and hydrogen-bonded dimers of serotonin

    Science.gov (United States)

    Dev, S.; Giri, K.; Majumder, M.; Sathyamurthy, N.

    2015-10-01

    The O-HṡṡṡN hydrogen-bonded dimer of serotonin is shown to be more stable than the stacked dimer in its ground electronic state, by using the Møller-Plesset second-order perturbation theory (MP2) and the 6-31g** basis set. The vertical excitation energy for the lowest π → π* transition for the monomer as well as the dimer is predicted by time-dependent density functional theory. The experimentally observed red shift of excitation wavelength on oligomerisation is explained in terms of the change in the HOMO-LUMO energy gap due to complex formation. The impact of dimer formation on the proton magnetic resonance spectrum of serotonin monomer is also examined.

  5. Microtechnology management considering test and cost aspects for stacked 3D ICs with MEMS

    Science.gov (United States)

    Hahn, K.; Wahl, M.; Busch, R.; Grünewald, A.; Brück, R.

    2018-01-01

    Innovative automotive systems require complex semiconductor devices currently only available in consumer grade quality. The European project TRACE will develop and demonstrate methods, processes, and tools to facilitate usage of Consumer Electronics (CE) components to be deployable more rapidly in the life-critical automotive domain. Consumer electronics increasingly use heterogeneous system integration methods and "More than Moore" technologies, which are capable to combine different circuit domains (Analog, Digital, RF, MEMS) and which are integrated within SiP or 3D stacks. Making these technologies or at least some of the process steps available under automotive electronics requirements is an important goal to keep pace with the growing demand for information processing within cars. The approach presented in this paper aims at a technology management and recommendation system that covers technology data, functional and non-functional constraints, and application scenarios, and that will comprehend test planning and cost consideration capabilities.

  6. Layer-component-based communication stack framework for wireless residential control systems

    DEFF Research Database (Denmark)

    Torbensen, Rune; Hjorth, Theis

    2010-01-01

    This paper describes methods to lower the entry barrier for creating products that interoperate in the emerging heterogeneous residential control network domain. For designing reconfigurable, layer-component-based communication stacks, a flexible framework is proposed that supports several types ...... shown how the framework facilitates fast prototyping and makes developing secure wireless control systems less complex....... of nodes such as bridges, controllers, sensor/actuators - as well as secure communication between them. A special messaging system facilitates inter-component communication, and a Virtual Port Service protocol enables resource addressing. The end-devices in the heterogeneous network are made accessible...... on a common IP infrastructure, regardless of individual wireless technology. Legacy home automation devices are also supported. A prototype has been implemented on multiple resource-constrained hardware platforms, to demonstrate that the solution is both feasible for low-cost devices and portable. It has been...

  7. Layer-component-based communication stack framework for wireless residential control systems

    DEFF Research Database (Denmark)

    Torbensen, R.; Hjorth, Theis S.

    2011-01-01

    This paper describes methods to lower the entry barrier for creating products that interoperate in the emerging heterogeneous residential control network domain. For designing reconfigurable, layer-component-based communication stacks, a flexible framework is proposed that supports several types ...... shown how the framework facilitates fast prototyping and makes developing secure wireless control systems less complex....... of nodes such as bridges, controllers, sensor/actuators – as well as secure communication between them. A special messaging system facilitates inter-component communication, and a Virtual Port Service protocol enables resource addressing. The end-devices in the heterogeneous network are made accessible...... on a common IP infrastructure, regardless of individual wireless technology. Legacy home automation devices are also supported. A prototype has been implemented on multiple resource-constrained hardware platforms, to demonstrate that the solution is both feasible for low-cost devices and portable. It has been...

  8. 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.

  9. 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.

  10. Preliminary study on rotary ultrasonic machining of CFRP/Ti stacks.

    Science.gov (United States)

    Cong, W L; Pei, Z J; Treadwell, C

    2014-08-01

    Reported drilling methods for CFRP/Ti stacks include twist drilling, end milling, core grinding, and their derived methods. The literature does not have any report on drilling of CFRP/Ti stacks using rotary ultrasonic machining (RUM). This paper, for the first time, reports a study on drilling of CFRP/Ti stacks using RUM. It also compares results on drilling of CFRP/Ti stacks using RUM with reported results on drilling of CFRP/Ti stacks using other methods. When drilling CFRP/Ti stacks using RUM, cutting force, torque, and CFRP surface roughness were lower, hole size variation was smaller, CFRP groove depth was smaller, tool life was longer, and there was no obvious Ti exit burr and CFRP entrance delamination. Ti surface roughness when drilling of CFRP/Ti stacks using RUM was about the same as those when using other methods. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Theoretical study on effects of curvature of graphene in conjunction with simultaneous anion- and - stacking interactions

    Directory of Open Access Journals (Sweden)

    Pouya Karimi

    2015-12-01

    Full Text Available A graphene sheet (C102H30 has been rolled up by computational quantum chemistry methods to construct single-walled carbon nanotube fragments (SWCNTFs. The anion-π interactions of F- anion together with π-π stacking interactions of benzene on inner face and outer face of the central rings of SWCNTFs have been concurrently investigated. Structural parameters and energy data of the ternary benzene-SWCNTF-F- complexes were considered. Also, effects of charge transfer and aromaticity were estimated to determine how curvature of graphene influences on simultaneous anion-π and π-π stacking interactions.  Results indicate that curvature of graphene leads to structural changes in SWCNTFs which effects on simultaneous interactions of F- anion and benzene with SWCNTFs. Also, results show that although p-p stacking is a weak interaction, but it can impact on order of binding energies in complexes involved both p-p stacking and anion-p interactions. 

  12. Characterization of dry-stack interlocking compressed earth blocks

    OpenAIRE

    Moreira, Thomas Wilfried Sturm; Ramos, Luís F.; Lourenço, Paulo B.

    2015-01-01

    Earth has been a traditional building material to construct houses in Africa. One of the most common techniques is the use of sun dried or kiln fired adobe bricks with mud mortar. Fired bricks are the main cause for deforestation in countries like Malawi. Although this technique is low-cost, the bricks vary largely in shape, strength and durability. This leads to weak houses which suffer considerable damage during floods and seismic events. One solution is the use of dry-stack masonry with st...

  13. Production and Reliability Oriented SOFC Cell and Stack Design

    DEFF Research Database (Denmark)

    Hauth, Martin; Lawlor, Vincent; Cartellieri, Peter

    2017-01-01

    established. The probabilistic models were related to the experimentally obtained properties of base materials to establish a statistical relationship between the material properties and the most relevant load effects. Software algorithms for meta models that allow the detection of relationships between input...... in production, material and operating parameters for the optimization phase. A methodology for 3D description of spatial distribution of material properties based on a random field models was developed and validated by experiments. Homogenized material models on multiple levels of the SOFC stack were...

  14. Heteroplasmon hybridization in stacked complementary plasmo-photonic crystals.

    Science.gov (United States)

    Iwanaga, Masanobu; Choi, Bongseok

    2015-03-11

    We constructed plasmo-photonic crystals in which efficient light-trapping, plasmonic resonances couple with photonic guided resonances of large density of states and high-quality factor. We have numerically and experimentally shown that heteroplasmon hybrid modes emerge in stacked complementary (SC) plasmo-photonic crystals. The resonant electromagnetic-field distributions evidence that the two hybrid modes originate from two different heteroplasmons, exhibiting a large energy splitting of 300 meV. We further revealed a series of plasmo-photonic modes in the SC crystals.

  15. Pressurized Operation of a Planar Solid Oxide Cell Stack

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Sun, Xiufu; Ebbesen, Sune Dalgaard

    2016-01-01

    Solid oxide cells (SOCs) can be operated either as fuel cells (SOFC) to convert fuels to electricity or as electrolyzers (SOEC) to convert electricity to fuels such as hydrogen or methane. Pressurized operation of SOCs provide several benefits on both cell and system level. If successfully matured...... (electrode performance) increases for thermodynamic and kinetic reasons, respectively. Further, the summit frequency of the gas concentration impedance arc and the pressure difference across the stack and heat exchangers is seen to decrease with increasing pressure following a power-law expression. Finally...

  16. Introduction of a stack-phantom for PET

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  17. Nanocomposite Materials of Alternately Stacked C60 Monolayer and Graphene

    International Nuclear Information System (INIS)

    Ishikawa, M.; Miura, K.; Kamiya, S.; Yoshimoto, S.; Suzuki, M.; Kuwahara, D.; Sasaki, N.

    2010-01-01

    We synthesized the novel nanocomposite consisting alternately of a stacked single graphene sheet and a C 60 monolayer by using the graphite intercalation technique in which alkylamine molecules help intercalate large C 60 molecules into the graphite. Moreover, it is found that the intercalated C 60 molecules can rotate in between single graphene sheets by using C 13 NMR measurements. This preparation method provides a general way for intercalating huge fullerene molecules into graphite, which will lead to promising materials with novel mechanical, physical, and electrical properties.

  18. Nanocomposite Materials of Alternately Stacked C60 Monolayer and Graphene

    Directory of Open Access Journals (Sweden)

    Makoto Ishikawa

    2010-01-01

    Full Text Available We synthesized the novel nanocomposite consisting alternately of a stacked single graphene sheet and a C60 monolayer by using the graphite intercalation technique in which alkylamine molecules help intercalate large C60 molecules into the graphite. Moreover, it is found that the intercalated C60 molecules can rotate in between single graphene sheets by using C13 NMR measurements. This preparation method provides a general way for intercalating huge fullerene molecules into graphite, which will lead to promising materials with novel mechanical, physical, and electrical properties.

  19. Improved DNA clamps by stacking to adjacent nucleobases

    DEFF Research Database (Denmark)

    Fatthalla, M.I.; Pedersen, Erik Bjerregaard

    2012-01-01

    Three or four aromatic rings interconnected by acetylene bridges form a stiff conjugated system with sufficient conformational freedom to make it useful to link together the two strands of a DNA clamp. Upon targeting a ssDNA, the conformational flexibility allows better stacking of the linker...... to the underlying non-planar base triplet in the formed triplex. This type of triplexes has a substantially higher thermal melting temperature which can be further improved by inserting locked nucleic acids (LNAs) in the Hoogsteen part of the clamp. An extremely high sensitivity to mismatches is observed...

  20. Evaluation of a stack: A concrete chimney with brick liner

    International Nuclear Information System (INIS)

    Joshi, J.R.; Amin, J.A.; Porthouse, R.A.

    1995-01-01

    A 200 ft. tall stack, consisting of a concrete chimney with an independent acid proof brick liner built in the 1950's, serving the Separations facility at the Savannah River Site (SRS), was evaluated for the performance category 3 (PC3) level of Natural Phenomena Hazards (NPH) effects. The inelastic energy absorption capacity of the concrete chimney was considered in the evaluation of the earthquake resistance, in particular, to compute the F μ factor. The calculated value of F μ exceeded 3.0, while the seismic demand for the PC3 level, using an F μ value of 1.5, was found to be less than the capacity of the concrete chimney. The capacity formulation of ACI 307 was modified to incorporate the effect of an after design opening on the tension side. There are considerable uncertainties in determining the earthquake resistance of the independent brick liner. The critical liner section, located at the bottom of the breeching opening, does not meet the current recommendations. A discussion is provided for the possible acceptable values for the ''Moment Reduction Factor'', R w or F μ for the liner. Comments are provided on the comparison of stack demands using response spectra (RS) versus time history (TH) analysis, with and without soil structure interaction (SSI) effects

  1. Enhancing THz Absorption using Thin-Film Multilayer Stacks

    Science.gov (United States)

    Grbovic, Dragoslav; Bolakis, Christos; Karunasiri, Gamani

    2010-03-01

    Terahertz imaging has seen significant proliferation in recent years. This band of electromagnetic spectrum has been underutilized for a long time due to the lack of sufficiently powerful sources and sensitive detectors. Because of virtually harmless effects on living tissue, terahertz (THz) radiation is attractive for various applications, ranging from non-invasive medical diagnostics to detection of concealed weapons. Our work focuses on identifying materials, or more specifically a stack of thin-films with increased absorption in the band of interest. In this work, we demonstrate a method that combines finite element modeling, thin-film deposition and experimental characterization to create highly-absorptive multi-layer stacks. Finite element modeling is used to simulate the absorption of a combination of thin dielectric and metallic films. Metals are deposited using e-beam evaporation and dielectric films using plasma enhanced chemical vapor deposition (PECVD). The simulated and measured THz absorption characteristics of the composite thin-film multilayer stacts will be presented.

  2. Uniqueness of magnetotomography for fuel cells and fuel cell stacks

    International Nuclear Information System (INIS)

    Lustfeld, H; Hirschfeld, J; Reissel, M; Steffen, B

    2009-01-01

    The criterion for the applicability of any tomographic method is its ability to construct the desired inner structure of a system from external measurements, i.e. to solve the inverse problem. Magnetotomography applied to fuel cells and fuel cell stacks aims at determining the inner current densities from measurements of the external magnetic field. This is an interesting idea since in those systems the inner electric current densities are large, several hundred mA per cm 2 and therefore relatively high external magnetic fields can be expected. Still the question remains how uniquely the inverse problem can be solved. Here we present a proof that by exploiting Maxwell's equations extensively the inverse problem of magnetotomography becomes unique under rather mild assumptions and we show that these assumptions are fulfilled in fuel cells and fuel cell stacks. Moreover, our proof holds true for any other device fulfilling the assumptions listed here. Admittedly, our proof has one caveat: it does not contain an estimate of the precision requirements the measurements need to fulfil for enabling reconstruction of the inner current densities from external magnetic fields.

  3. Low hydrostatic head electrolyte addition to fuel cell stacks

    Science.gov (United States)

    Kothmann, Richard E.

    1983-01-01

    A fuel cell and system for supply electrolyte, as well as fuel and an oxidant to a fuel cell stack having at least two fuel cells, each of the cells having a pair of spaced electrodes and a matrix sandwiched therebetween, fuel and oxidant paths associated with a bipolar plate separating each pair of adjacent fuel cells and an electrolyte fill path for adding electrolyte to the cells and wetting said matrices. Electrolyte is flowed through the fuel cell stack in a back and forth fashion in a path in each cell substantially parallel to one face of opposite faces of the bipolar plate exposed to one of the electrodes and the matrices to produce an overall head uniformly between cells due to frictional pressure drop in the path for each cell free of a large hydrostatic head to thereby avoid flooding of the electrodes. The bipolar plate is provided with channels forming paths for the flow of the fuel and oxidant on opposite faces thereof, and the fuel and the oxidant are flowed along a first side of the bipolar plate and a second side of the bipolar plate through channels formed into the opposite faces of the bipolar plate, the fuel flowing through channels formed into one of the opposite faces and the oxidant flowing through channels formed into the other of the opposite faces.

  4. Magnetization loss for stacks of ReBCO tapes

    Science.gov (United States)

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

    2017-02-01

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

  5. Interface band alignment in high-k gate stacks

    Science.gov (United States)

    Eric, Bersch; Hartlieb, P.

    2005-03-01

    In order to successfully implement alternate high-K dielectric materials into MOS structures, the interface properties of MOS gate stacks must be better understood. Dipoles that may form at the metal/dielectric and dielectric/semiconductor interfaces make the band offsets difficult to predict. We have measured the conduction and valence band densities of states for a variety MOS stacks using in situ using inverse photoemission (IPE) and photoemission spectroscopy (PES), respectively. Results obtained from clean and metallized (with Ru or Al) HfO2/Si, SiO2/Si and mixed silicate films will be presented. IPE indicates a shift of the conduction band minimum (CBM) to higher energy (i.e. away from EF) with increasing SiO2. The effect of metallization on the location of band edges depends upon the metal species. The addition of N to the dielectrics shifts the CBM in a way that is thickness dependent. Possible mechanisms for these observed effects will be discussed.

  6. Stacking fault tetrahedron induced plasticity in copper single crystal

    International Nuclear Information System (INIS)

    Zhang, Liang; Lu, Cheng; Tieu, Kiet; Su, Lihong; Zhao, Xing; Pei, Linqing

    2017-01-01

    Stacking fault tetrahedron (SFT) is the most common type of vacancy clustered defects in fcc metals and alloys, and can play an important role in the mechanical properties of metallic materials. In this study, molecular dynamics (MD) simulations were carried out to investigate the incipience of plasticity and the underlying atomic mechanisms in copper single crystals with SFT. Different deformation mechanisms of SFT were reported due to the crystal orientations and loading directions (compression and tension). The results showed that the incipient plasticity in crystals with SFT resulted from the heterogeneous dislocation nucleation from SFT, so the stress required for plastic deformation was less than that needed for perfect single crystals. Three crystal orientations ([1 0 0], [1 1 0] and [1 1 1]) were specified in this study because they can represent most of the typical deformation mechanisms of SFT. MD simulations revealed that the structural transformation of SFT was frequent under the applied loading; a metastable SFT structure and the collapse of SFT were usually observed. The structural transformation resulted in a different reduction of yield stress in compression and tension, and also caused a decreased or reversed compression/tension asymmetry. Compressive stress can result in the unfaulting of Frank loop in some crystal orientations. According to the elastic theory of dislocation, the process of unfaulting was closely related to the size of the dislocation loop and the stacking fault energy.

  7. Hyperspectral anomaly detection based on stacked denoising autoencoders

    Science.gov (United States)

    Zhao, Chunhui; Li, Xueyuan; Zhu, Haifeng

    2017-10-01

    Hyperspectral anomaly detection (AD) is an important technique of unsupervised target detection and has significance in real situations. Due to the high dimensionality of hyperspectral data, AD will be influenced by noise, nonlinear correlation of band, or other factors that lead to the decline of detection accuracy. To overcome this problem, a method of hyperspectral AD based on stacked denoising autoencoders (AE) (HADSDA) is proposed. Simultaneously, two different feature detection models, spectral feature (SF) and fused feature by clustering (FFC), are constructed to verify the effectiveness of the proposed algorithm. The SF detection model uses the SF of each pixel. The FFC detection model uses a similar set of pixels constructed by clustering and then fuses the set of pixels by the stacked denoising autoencoders algorithm (SDA). The SDA is an algorithm that can automatically learn nonlinear deep features of the image. Compared with other linear or nonlinear feature extraction methods, the detection result of the proposed algorithm is greatly improved. Experiment results show that the proposed algorithm is an excellent feature learning method and can achieve higher detection performance.

  8. Migration velocity analysis using pre-stack wave fields

    KAUST Repository

    Alkhalifah, Tariq Ali

    2016-08-25

    Using both image and data domains to perform velocity inversion can help us resolve the long and short wavelength components of the velocity model, usually in that order. This translates to integrating migration velocity analysis into full waveform inversion. The migration velocity analysis part of the inversion often requires computing extended images, which is expensive when using conventional methods. As a result, we use pre-stack wavefield (the double-square-root formulation) extrapolation, which includes the extended information (subsurface offsets) naturally, to make the process far more efficient and stable. The combination of the forward and adjoint pre-stack wavefields provides us with update options that can be easily conditioned to improve convergence. We specifically use a modified differential semblance operator to split the extended image into a residual part for classic differential semblance operator updates and the image (Born) modelling part, which provides reflections for higher resolution information. In our implementation, we invert for the velocity and the image simultaneously through a dual objective function. Applications to synthetic examples demonstrate the features of the approach.

  9. Stacking faults in a layered cobalt tellurium phosphate oxochloride

    Science.gov (United States)

    Zimmermann, Iwan; Johnsson, Mats

    2015-02-01

    The new compound Co2Te3(PO4)O6Cl was synthesized by chemical reactions in a sealed and evacuated silica tube. The crystal structure was solved from single crystal diffraction data and is made up by charge neutral layers. Within the layers two types of chains are made up by edge sharing [CoO6] and [CoO5Cl] polyhedra respectively. The chains are separated by tellurium oxide and phosphate building blocks. There are only weak Van der Waals interactions in between the layers and severe diffuse scattering is observed due to faulted stacking of the layers. Structure solutions in a P-1 triclinic cell and a larger monoclinic cell in P21/c are discussed and compared to a computer generated model. The reasons for the stacking faults may be due to that there are two positions available for each layer that results in similar connectivity to the next layer in addition to the relatively wide channels in between the layers that reduce the Van der Waals interactions in between them.

  10. The Alpine nappe stack in western Austria: A crustal-scale cross-section

    Science.gov (United States)

    Pomella, Hannah; Bertrand, Audrey; Ortner, Hugo; Zerlauth, Michael; Fügenschuh, Bernhard

    2013-04-01

    A N-S oriented crustal-scale cross-section was constructed east of the Rhine valley in Vorarlberg, western Austria addressing the central Alps-eastern Alps boundary. The construction was based on published data, surface geology, drillings, as well as on reinterpreted seismic lines. The general architecture of the examined area can be described as a typical foreland fold-and-thrust belt, comprising the tectonic units of the Subalpine Molasse, (Ultra-)Helvetic, Penninic, and Austroalpine nappes. These units overthrusted the autochthonous Molasse along the south-dipping listric Alpine basal thrust. The thermotectonic evolution of this nappe stack is adressed by Bertrand et al. (this session). The Subalpine Molasse is multiply stacked, forming a triangle-zone (Müller et al. 1984). The shortening within the Subalpine Molasse in the cross section has been calculated using the Lower Marine Molasse as a reference and amounts to approx. 46 km, (~70%). Towards east the shortening within the Subalpine Molasse decreases dramatically as shown by Ortner et al. (this session). A well-defined seismic feature in the research area is the European basement together with its autochthonous cover, with a moderate southward dip from about 3500m BSL to approx. 6500m BSL along the ca. 50km long section. Several seismic sections show fault structures offsetting the top of the European basement as well as autochthonous cover. Another discontinuous double reflector that can be identified in several seismic sections is interpreted as the base of the Helvetic nappe complex (approx. at 5000m BSL in the southernmost parts). The internal structure of the Helvetic nappe stack could hardly be resolved. The assumed hinterland dipping duplex-structure of the Helvetic nappes results from surface and borehole-data. However, there are at least two Helvetic nappes needed to fill the available space. The deeper one, termed "Hohenemse nappe" (Wyssling, 1985), is overlain by the superficially exposed

  11. 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

  12. π -Stacking interactions in YFP, quantum mechanics and force field evaluations in the S0 and S1 states

    Science.gov (United States)

    Merabti, Karim Elhadj; Azizi, Sihem; Ridard, Jacqueline; Lévy, Bernard; Demachy, Isabelle

    2017-08-01

    We study the π -stacking interaction between the chromophore and Tyr203 in the Yellow Fluorescent Protein (YFP) in order to (i) evaluate the contribution of the internal interaction energy of the isolated Chromophore-Tyrosine complex (Eint) to the 26 nm red shift observed from GFP to YFP, (ii) compare the effects of Eint and of the proteic environment. To that end, we perform quantum mechanical and force field (ff) calculations of the isolated complex in S0 and S1 states on a large sample of geometries, together with molecular dynamics simulations and potential of mean force analysis. The calculated absorption wavelengths are found red shifted with respect to the isolated chromophore by 12-19 nm, that represents a large part of the GFP-YFP shift. We find that the effect of the protein is determinant on the dynamics of the complex while the error that results from using a classicalff is of limited effect.

  13. The Integration of CloudStack and OCCI/OpenNebula with DIRAC

    International Nuclear Information System (INIS)

    Méndez Muñoz, Víctor; Merino Arévalo, Gonzalo; Fernández Albor, Víctor; Saborido Silva, Juan José; Graciani Diaz, Ricardo; Casajús Ramo, Adriàn; Fernández Pena, Tomás

    2012-01-01

    The increasing availability of Cloud resources is arising as a realistic alternative to the Grid as a paradigm for enabling scientific communities to access large distributed computing resources. The DIRAC framework for distributed computing is an easy way to efficiently access to resources from both systems. This paper explains the integration of DIRAC with two open-source Cloud Managers: OpenNebula (taking advantage of the OCCI standard) and CloudStack. These are computing tools to manage the complexity and heterogeneity of distributed data center infrastructures, allowing to create virtual clusters on demand, including public, private and hybrid clouds. This approach has required to develop an extension to the previous DIRAC Virtual Machine engine, which was developed for Amazon EC2, allowing the connection with these new cloud managers. In the OpenNebula case, the development has been based on the CernVM Virtual Software Appliance with appropriate contextualization, while in the case of CloudStack, the infrastructure has been kept more general, which permits other Virtual Machine sources and operating systems being used. In both cases, CernVM File System has been used to facilitate software distribution to the computing nodes. With the resulting infrastructure, the cloud resources are transparent to the users through a friendly interface, like the DIRAC Web Portal. The main purpose of this integration is to get a system that can manage cloud and grid resources at the same time. This particular feature pushes DIRAC to a new conceptual denomination as interware, integrating different middleware. Users from different communities do not need to care about the installation of the standard software that is available at the nodes, nor the operating system of the host machine which is transparent to the user. This paper presents an analysis of the overhead of the virtual layer, doing some tests to compare the proposed approach with the existing Grid solution. License

  14. Air-Cooled Stack Freeze Tolerance Freeze Failure Modes and Freeze Tolerance Strategies for GenDriveTM Material Handling Application Systems and Stacks Final Scientific Report

    Energy Technology Data Exchange (ETDEWEB)

    Hancock, David, W.

    2012-02-14

    Air-cooled stack technology offers the potential for a simpler system architecture (versus liquid-cooled) for applications below 4 kilowatts. The combined cooling and cathode air allows for a reduction in part count and hence a lower cost solution. However, efficient heat rejection challenges escalate as power and ambient temperature increase. For applications in ambient temperatures below freezing, the air-cooled approach has additional challenges associated with not overcooling the fuel cell stack. The focus of this project was freeze tolerance while maintaining all other stack and system requirements. Through this project, Plug Power advanced the state of the art in technology for air-cooled PEM fuel cell stacks and related GenDrive material handling application fuel cell systems. This was accomplished through a collaborative work plan to improve freeze tolerance and mitigate freeze-thaw effect failure modes within innovative material handling equipment fuel cell systems designed for use in freezer forklift applications. Freeze tolerance remains an area where additional research and understanding can help fuel cells to become commercially viable. This project evaluated both stack level and system level solutions to improve fuel cell stack freeze tolerance. At this time, the most cost effective solutions are at the system level. The freeze mitigation strategies developed over the course of this project could be used to drive fuel cell commercialization. The fuel cell system studied in this project was Plug Power's commercially available GenDrive platform providing battery replacement for equipment in the material handling industry. The fuel cell stacks were Ballard's commercially available FCvelocity 9SSL (9SSL) liquid-cooled PEM fuel cell stack and FCvelocity 1020ACS (Mk1020) air-cooled PEM fuel cell stack.

  15. 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.

  16. 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

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

    Science.gov (United States)

    2010-06-02

    This report covers efforts by the Hawaii Natural Energy Institute (HNEI) of the University of Hawaii under the ONR-funded Ion Tiger UAV award that included testing of Ion Tiger fuel cell stacks in HNEI’s Hawaii Fuel Cell Test Facility located in Honolulu, Hawaii. Work was focused on steady-state stack characteristics of Protonex fuel cell stacks under various operating conditions. In addition, Hardware-in-the-Loop testing was performed to characterize dynamic

  18. 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)

  19. 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

  20. Planar SOFC technology: stack design and development for lower cost and manufacturability

    Energy Technology Data Exchange (ETDEWEB)

    Pyke, S.H.; Howard, P.J.; Leah, R.T.

    2002-07-01

    This report summarises the results of a project to examine the performance of an externally manifolded solid oxide fuel cell (SOFC) stack based on a planar, anode-supported cells geometry, and to develop sealing materials and a design for a SOFC stack for potential low cost manufacture. The testing of short stacks, the development of innovative glass-ceramic sealing materials, and the development of an SOFC model to assess cell performance are described along with the development of a new stack geometry based on an internally manifolded geometry.

  1. Exact and heuristic solutions to the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

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

    The double travelling salesman problem with multiple stacks (DTSPMS) is a pickup and delivery problem where pickups and deliveries are separated, such that all pickup operations are performed before the first delivery takes place. All operations are carried out by one vehicle and no reloading...... is allowed. The vehicle provides several separated (horizontal) stacks/rows for the transportation of the orders, such that each stack is accessed using a LIFO principle, independently of the other stacks. In a real-life setting the dimensions of the problem is 33 orders each consisting of one euro...

  2. 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.

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

    Science.gov (United States)

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

    2012-01-01

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

  4. Testing and Evaluation of an Advanced High Performance Planar SOFC Stack

    National Research Council Canada - National Science Library

    Elangovan, S

    1999-01-01

    .... SOFCo has conducted several programs which synergistically address this objective: an internally funded program focusing on stack development and system integration for pipeline natural gas (PNG...

  5. 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.

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

    Science.gov (United States)

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

    2017-07-01

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

  7. Very Weak Signals (VWS detected by stacking method according to different astronomical periodicities (HiCum

    Directory of Open Access Journals (Sweden)

    M. van Ruymbeke

    2007-11-01

    Full Text Available A stacking method to detect very weak signals is introduced in this paper. This method is to stack observed data in different well known periodicities according to the astronomical clock since majority geophysical observations are time based. We validated this method by applying it in four different cases. Interactions behind the observed parameters become obviously after it is stacked in two diurnal and semidiurnal tidal periodical waves. Amplitude and phase variations will be also measurable when a sliding windows stacking is used. This could be an important reference to find precursors before some earthquakes and volcanic events, corresponding to attenuations of medium patterns.

  8. Plume trajectory formation under stack tip self-enveloping

    Science.gov (United States)

    Gribkov, A. M.; Zroichikov, N. A.; Prokhorov, V. B.

    2017-10-01

    The phenomenon of stack tip self-enveloping and its influence upon the conditions of plume formation and on the trajectory of its motion are considered. Processes are described occurring in the initial part of the plume while the interaction between vertically directed flue gases outflowing from the stack and a horizontally directed moving air flow at high wind velocities that lead to the formation of a flag-like plume. Conditions responsible for the origin and evolution of interaction between these flows are demonstrated. For the first time, a plume formed under these conditions without bifurcation is registered. A photo image thereof is presented. A scheme for the calculation of the motion of a plume trajectory is proposed, the quantitative characteristics of which are obtained based on field observations. The wind velocity and direction, air temperature, and atmospheric turbulence at the level of the initial part of the trajectory have been obtained based on data obtained from an automatic meteorological system (mounted on the outer parts of a 250 m high stack no. 1 at the Naberezhnye Chelny TEPP plant) as well as based on the results of photographing and theodolite sighting of smoke puffs' trajectory taking into account their velocity within its initial part. The calculation scheme is supplemented with a new acting force—the force of self-enveloping. Based on the comparison of the new calculation scheme with the previous one, a significant contribution of this force to the development of the trajectory is revealed. A comparison of the natural full-scale data with the results of the calculation according to the proposed new scheme is made. The proposed calculation scheme has allowed us to extend the application of the existing technique to the range of high wind velocities. This approach would make it possible to simulate and investigate the trajectory and full rising height of the calculated the length above the mouth of flue-pipes, depending on various modal

  9. Stacking and energetic contribution of aromatic islands at the binding interface of antibody proteins

    Science.gov (United States)

    2010-01-01

    Background The enrichment and importance of some aromatic residues, such as Tyr and Trp, have been widely noticed at the binding interfaces of antibodies from many experimental and statistical results, some of which were even identified as “hot spots” contributing significantly greater to the binding affinity than other amino acids. However, how these aromatic residues influence the immune binding still deserves further investigation. A large-scale examination was done regarding the local spatial environment around the interfacial Tyr or Trp residues. Energetic contribution of these Tyr and Trp residues to the binding affinity was then studied regarding 82 representative antibody interfaces covering 509 immune complexes from the PDB database and IMGT/3Dstructure-DB. Results The connectivity analysis of interfacial residues showed that Tyr and Trp tended to cluster into the spatial Aromatic Islands (AI) rather than being distributed randomly at the antibody interfaces. Out of 82 antibody-antigen complexes, 72% (59) interfaces were found to contain AI with more than 3 aromatic residues. The statistical test against an empirical distribution indicated that the existence of AI was significant in about 60% representative antibody interfaces. Secondly, the loss of solvent accessible surface area (SASA) for side chains of aromatic residues between actually crowded state and independent state was nicely correlated with the AI size increasing in a linearly positive way which indicated that the aromatic side chains in AI tended to take a compact and ordered stacking conformation at the interfaces. Interestingly, the SASA loss of AI was also correlated roughly with the averaged gap of binding free energy between the theoretical and experimental data for immune complexes. Conclusions The results of our study revealed the wide existence and statistical significance of “Aromatic Island” (AI) composed of the spatially clustered Tyr and Trp residues at the antibody

  10. The stack: a new bacterial structure analyzed in the Antarctic bacterium Pseudomonas deceptionensis M1(T by transmission electron microscopy and tomography.

    Directory of Open Access Journals (Sweden)

    Lidia Delgado

    Full Text Available In recent years, improvements in transmission electron microscopy (TEM techniques and the use of tomography have provided a more accurate view of the complexity of the ultrastructure of prokaryotic cells. Cryoimmobilization of specimens by rapid cooling followed by freeze substitution (FS and sectioning, freeze fracture (FF and observation of replica, or cryoelectron microscopy of vitreous sections (CEMOVIS now allow visualization of biological samples close to their native state, enabling us to refine our knowledge of already known bacterial structures and to discover new ones. Application of these techniques to the new Antarctic cold-adapted bacterium Pseudomonasdeceptionensis M1(T has demonstrated the existence of a previously undescribed cytoplasmic structure that does not correspond to known bacterial inclusion bodies or membranous formations. This structure, which we term a "stack", was mainly visualized in slow growing cultures of P. deceptionensis M1(T and can be described as a set of stacked membranous discs usually arranged perpendicularly to the cell membrane, but not continuous with it, and found in variable number in different locations within the cell. Regardless of their position, stacks were mostly observed very close to DNA fibers. Stacks are not exclusive to P. deceptionensis M1(T and were also visualized in slow-growing cultures of other bacteria. This new structure deserves further study using cryoelectron tomography to refine its configuration and to establish whether its function could be related to chromosome dynamics.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-29

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

  12. Availability Analysis of the Ventilation Stack CAM Interlock System

    International Nuclear Information System (INIS)

    YOUNG, J.

    2000-01-01

    Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability. Further, requiring an alarm to actuate upon CAM failure is not necessary to maintain the availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability. However, if CAM failures were only detected by the 92-day functional tests required in the Authorization Basis (AB), CAM availability would be much less than that credited in the safety analysis. Therefore it is recommended that the current surveillance practice of daily simple system checks, 30-day source checks and 92-day functional tests be continued in order to maintain CAM availability

  13. Multi-channel temperature measurement system for automotive battery stack

    Science.gov (United States)

    Lewczuk, Radoslaw; Wojtkowski, Wojciech

    2017-08-01

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

  14. Engineering the hypersonic phononic band gap of hybrid Bragg stacks.

    Science.gov (United States)

    Schneider, Dirk; Liaqat, Faroha; El Boudouti, El Houssaine; El Hassouani, Youssef; Djafari-Rouhani, Bahram; Tremel, Wolfgang; Butt, Hans-Jürgen; Fytas, George

    2012-06-13

    We report on the full control of phononic band diagrams for periodic stacks of alternating layers of poly(methyl methacrylate) and porous silica combining Brillouin light scattering spectroscopy and theoretical calculations. These structures exhibit large and robust on-axis band gaps determined by the longitudinal sound velocities, densities, and spacing ratio. A facile tuning of the gap width is realized at oblique incidence utilizing the vector nature of the elastic wave propagation. Off-axis propagation involves sagittal waves in the individual layers, allowing access to shear moduli at nanoscale. The full theoretical description discerns the most important features of the hypersonic one-dimensional crystals forward to a detailed understanding, a precondition to engineer dispersion relations in such structures.

  15. RPLsh: An Interactive Shell for Stack-based Numerical Computation

    Science.gov (United States)

    Rauch, Kevin P.

    RPL shell or RPLsh, is an interactive numerical shell designed to combine the convenience of a hand-held calculator with the computational power and advanced numerical functionality of a workstation. The user interface is modelled after stack-based scientific calculators such as those made by Hewlett-Packard RPL is the name of the Forth-like programming language used in the HP 48 series), but includes many features not found in hand-held devices, such as a multi-threaded kernel with job control, integrated extended precision arithmetic, a large library of special functions, and a dynamic, resizable window display. As a native C/C++ application, it is over 1000 times faster than HP 48 emulators (e.g. Emu48 ) in simple benchmarks; for extended precision numerical analysis, its performance can exceed that of Mathematica by similar amounts. Current development focuses on interactive user functionality, with comprehensive programming and debugging support to follow.

  16. Improved exact method for the double TSP with multiple stacks

    DEFF Research Database (Denmark)

    Lusby, Richard Martin; Larsen, Jesper

    2011-01-01

    The Double TSP with Multiple Stacks is a logistics problem where one must, using a container, transport a given number of orders from a set of pickup customers to a set of delivery customers at minimum cost. Each order corresponds to the movement of one pallet, all pickups must be completed before...... the first delivery, and the container cannot be repacked once packed. In this paper we improve the previously proposed exact method of Lusby et al. (Int Trans Oper Res 17 (2010), 637–652) through an additional preprocessing technique that uses the longest common subsequence between the respective pickup...... and delivery problems. The results suggest an impressive improvement, and we report, for the first time, optimal solutions to several unsolved instances from the literature containing 18 customers. Instances with 28 customers are also shown to be solvable within a few percent of optimality. © 2011 Wiley...

  17. CaPiTo: protocol stacks for services

    DEFF Research Database (Denmark)

    Gao, Han; Nielson, Flemming; Nielson, Hanne Riis

    2011-01-01

    CaPiTo allows the modelling of service-oriented applications using process algebras at three levels of abstraction. The abstract level focuses on the key functionality of the services; the plug-in level shows how to obtain security using standardised protocol stacks; finally, the concrete level...... for ensuring the absence of security flaws. The method used is based on static analysis of the corresponding LySa specifications. We illustrate the development on two industrial case studies; one taken from the banking sector and the other a single sign-on protocol....... allows to consider how security is obtained using asymmetric and symmetric cryptographic primitives. The CaPiTo approach therefore caters for a variety of developers that need to cooperate on designing and implementing service-oriented applications. We show how to formally analyse CaPiTo specifications...

  18. Strontium titanate/silicon-based terahertz photonic crystal multilayer stack

    International Nuclear Information System (INIS)

    Xin, J.Z.; Jim, K.L.; Tsang, Y.H.; Chan, H.L.W.; Leung, C.W.; Yang, J.; Gong, X.J.; Chen, L.Q.; Gao, F.

    2012-01-01

    A one-dimensional photonic crystal working in the terahertz (THz) range was designed and implemented. To facilitate the design, the transmission properties of strontium titanate crystals were characterized by THz-time-domain spectroscopy. Relatively high refractive index (∝18.5) and transmission ratio (0.08) were observed between 0.2 to 1 THz. A stacked structure of (Si d Si /STO d STO ) N /Si d Si was then designed, with transmission spectra calculated by the transfer matrix method. The effects of the filling ratio (d STO /(d Si +d STO )), periodicity (d Si +d STO ) and the number of repeats N on the transmission of PC were investigated. The effect of introducing a defect layer was also studied. Based on these, Si/STO multilayers with STO defect thickness of 125 μm and 200 μm were measured. The shift of the defect mode was observed and compared with the calculations. (orig.)

  19. Fast static field CIPT mapping of unpatterned MRAM film stacks

    Science.gov (United States)

    Kjaer, Daniel; Hansen, Ole; Hartmann Henrichsen, Henrik; Chenchen, Jacob Wang; Noergaard, Kristian; Folmer Nielsen, Peter; Hjorth Petersen, Dirch

    2015-04-01

    While investigating uniformity of magnetic tunnel junction (MTJ) stacks we find experimentally and analytically that variation in the resistance area product (RA) is more important to monitor as compared to the tunnel magnetoresistance (TMR), which is less sensitive to MTJ variability. The standard 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 as asymmetrical variations related to the MTJ deposition conditions.

  20. Optimization Design of Bipolar Plate Flow Field in PEM Stack

    Science.gov (United States)

    Wen, Ming; He, Kanghao; Li, Peilong; Yang, Lei; Deng, Li; Jiang, Fei; Yao, Yong

    2017-12-01

    A new design of bipolar plate flow field in proton exchange membrane (PEM) stack was presented to develop a high-performance transfer efficiency of the two-phase flow. Two different flow fields were studied by using numerical simulations and the performance of the flow fields was presented. the hydrodynamic properties include pressure gap between inlet and outlet, the Reynold’s number of the two types were compared based on the Navier–Stokes equations. Computer aided optimization software was implemented in the design of experiments of the preferable flow field. The design of experiments (DOE) for the favorable concept was carried out to study the hydrodynamic properties when changing the design parameters of the bipolar plate.

  1. Development of Thread-compatible Open Source Stack

    Science.gov (United States)

    Zimmermann, Lukas; Mars, Nidhal; Schappacher, Manuel; Sikora, Axel

    2017-07-01

    The Thread protocol is a recent development based on 6LoWPAN (IPv6 over IEEE 802.15.4), but with extensions regarding a more media independent approach, which - additionally - also promises true interoperability. To evaluate and analyse the operation of a Thread network a given open source 6LoWPAN stack for embedded devices (emb::6) has been extended in order to comply with the Thread specification. The implementation covers Mesh Link Establishment (MLE) and network layer functionality as well as 6LoWPAN mesh under routing mechanism based on MAC short addresses. The development has been verified on a virtualization platform and allows dynamical establishment of network topologies based on Thread’s partitioning algorithm.

  2. Sodium-Induced Reordering of Atomic Stacks in Black Phosphorus

    KAUST Repository

    Cheng, Yingchun

    2017-01-12

    While theoretical simulations predict contradictory results about how the intercalation of foreign metal atoms affects the order of atomic layers in black phosphorus (BP), no direct experimental visualization work has yet clarified this ambiguity. By in situ electrochemical sodiation of BP inside a high-resolution transmission electron microscope and first-principles calculations, we found that sodium intercalation induces a relative glide of/ ⟨010⟩ {001}, resulting in reordering of atomic stacks from AB to AC in BP. The observed local amorphization in our experiments is triggered by lattice constraints. We predict that intercalation of sodium or other metal atoms introduces n-type carriers in BP. This potentially opens a new field for two-dimensional electronics based on BP.

  3. Edge blurring in stacked x-ray film screen combinations

    International Nuclear Information System (INIS)

    Lyle, J.W.

    1984-01-01

    The Advanced Experiments Group of B-Division, LLNL, has been seeking to improve the sensitivity and spatial resolution of stacked film screens for bremsstrahlung flash radiography of imploding, dense metal shells. In the work reported here, we experimentally measured the spreading of the x-ray shadow of the edge of a uranium block in two film-and-screen combinations. We also used the SANDYL code, which models photon and electron scattering, to calculate the theoretical edge spreading in an array of films and screens. Experimentally, the uranium edge was spread to a width of 1.7 mm in the combination 0.15-mm-Ta/NDT9-XAR5, and 1.5 mm in the combination 0.25-mm-Ta/NDT6-XAR5. The theoretical calculation agreed with these results

  4. Ab initio engineering of materials with stacked hexagonal tin frameworks

    Science.gov (United States)

    Shao, Junping; Beaufils, Clément; Kolmogorov, Aleksey N.

    2016-07-01

    The group-IV tin has been hypothesized to possess intriguing electronic properties in an atom-thick hexagonal form. An attractive pathway of producing sizable 2D crystallites of tin is based on deintercalation of bulk compounds with suitable tin frameworks. Here, we have identified a new synthesizable metal distannide, NaSn2, with a 3D stacking of flat hexagonal layers and examined a known compound, BaSn2, with buckled hexagonal layers. Our ab initio results illustrate that despite being an exception to the 8-electron rule, NaSn2 should form under pressures easily achievable in multi-anvil cells and remain (meta)stable under ambient conditions. Based on calculated Z2 invariants, the predicted NaSn2 may display topologically non-trivial behavior and the known BaSn2 could be a strong topological insulator.

  5. Implementing inverted master-slave 3D semiconductor stack

    Science.gov (United States)

    Coteus, Paul W.; Hall, Shawn A.; Takken, Todd E.

    2016-03-08

    A method and apparatus are provided for implementing an enhanced three dimensional (3D) semiconductor stack. A chip carrier has an aperture of a first length and first width. A first chip has at least one of a second length greater than the first length or a second width greater than the first width; a second chip attached to the first chip, the second chip having at least one of a third length less than the first length or a third width less than the first width; the first chip attached to the chip carrier by connections in an overlap region defined by at least one of the first and second lengths or the first and second widths; the second chip extending into the aperture; and a heat spreader attached to the chip carrier and in thermal contact with the first chip for dissipating heat from both the first chip and second chip.

  6. The Beam Characteristics of High Power Diode Laser Stack

    Science.gov (United States)

    Gu, Yuanyuan; Fu, Yueming; Lu, Hui; Cui, Yan

    2018-03-01

    Direct diode lasers have some of the most attractive features of any laser. They are very efficient, compact, wavelength versatile, low cost, and highly reliable. However, the full utilization of direct diode lasers has yet to be realized. However, the poor quality of diode laser beam itself, directly affect its application ranges, in order to better use of diode laser stack, need a proper correction of optical system, which requires accurate understanding of the diode laser beam characteristics. Diode laser could make it possible to establish the practical application because of rectangular beam patterns which are suitable to make fine bead with less power. Therefore diode laser cladding will open a new field of repairing for the damaged machinery parts which must contribute to recycling of the used machines and saving of cost.

  7. Effect of ship-stack effluents on cloud reflectivity

    Science.gov (United States)

    Coakley, James A., Jr.; Bernstein, Robert L.; Durkee, Philip A.

    1987-01-01

    Under stable meteorological conditions the effect of ship-stack exhaust on overlying clouds was detected in daytime satellite images as an enhancement in cloud reflectivity at 3.7 micrometers. The exhaust is a source of cloud-condensation nuclei that increases the number of cloud droplets while reducing droplet size. This reduction in droplet size causes the reflectivity at 3.7 micrometers to be greater than the levels for nearby noncontaminated clouds of similar physical characteristics. The increase in droplet number causes the reflectivity at 0.63 micrometer to be significantly higher for the contaminated clouds despite the likelihood that the exhaust is a source of particles that absorb at visible wavelengths. The effect of aerosols on cloud reflectivity is expected to have a larger influence on the earth's albedo than that due to the direct scattering and absorption of sunlight by the aerosols alone.

  8. Preloading Piezoelectric Stack Actuator in High-speed Nanopositioning Systems

    Directory of Open Access Journals (Sweden)

    Yuen Yong

    2016-10-01

    Full Text Available Recent development in high-speed nanotechnology applications such as scanning probe microscopy and nanofabrication has increased interest on the advancement of high-bandwidth flexure-guided nanopositioning systems. These systems are capable of providing motions with sub-nanometer resolution over a positioning bandwidth of a few kilohertz or more. High-speed nanopositioning devices are commonly driven by compact and stiff piezoelectric stack actuators. However, these actuators are highly sensitive to tensile and lateral forces. During high-speed operations, excessive inertia force due to the effective mass of nanopositioning system could potentially damage the actuator. To protect the piezoelectric actuator, preload is often applied to compensate for these inertial forces. This article surveys key challenges in existing preload techniques in the context of high-speed nanopositioning designs, and explores how these challenges can be overcome.

  9. Network Intrusion Detection through Stacking Dilated Convolutional Autoencoders

    Directory of Open Access Journals (Sweden)

    Yang Yu

    2017-01-01

    Full Text Available Network intrusion detection is one of the most important parts for cyber security to protect computer systems against malicious attacks. With the emergence of numerous sophisticated and new attacks, however, network intrusion detection techniques are facing several significant challenges. The overall objective of this study is to learn useful feature representations automatically and efficiently from large amounts of unlabeled raw network traffic data by using deep learning approaches. We propose a novel network intrusion model by stacking dilated convolutional autoencoders and evaluate our method on two new intrusion detection datasets. Several experiments were carried out to check the effectiveness of our approach. The comparative experimental results demonstrate that the proposed model can achieve considerably high performance which meets the demand of high accuracy and adaptability of network intrusion detection systems (NIDSs. It is quite potential and promising to apply our model in the large-scale and real-world network environments.

  10. Emission shaping in fluorescent proteins: role of electrostatics and π-stacking.

    Science.gov (United States)

    Park, Jae Woo; Rhee, Young Min

    2016-02-07

    For many decades, simulating the excited state properties of complex systems has been an intriguing but daunting task due to its high computational cost. Here, we apply molecular dynamics based techniques with interpolated potential energy surfaces toward calculating fluorescence spectra of the green fluorescent protein (GFP) and its variants in a statistically meaningful manner. With the GFP, we show that the diverse electrostatic tuning can shape the emission features in many different ways. By computationally modulating the electrostatic interactions between the chromophore phenoxy oxygen and its nearby residues, we demonstrate that we indeed can shift the emission to the blue or to the red side in a predictable manner. We rationalize the shifting effects of individual residues in the GFP based on the responses of both the adiabatic and the diabatic electronic states of the chromophore. We next exhibit that the yellow emitting variant, the Thr203Tyr mutant, generates changes in the electrostatic interactions and an additional π-stacking interaction. These combined effects indeed induce a red shift to emit the fluorescence into the yellow region. With the series of demonstrations, we suggest that our approach can provide sound rationales and useful insights in understanding different responses of various fluorescent complexes, which may be helpful in designing new light emitting proteins and other related systems in future studies.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-01

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

  12. FERMI LAT STACKING ANALYSIS OF SWIFT LOCALIZED GRBs

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, M.; Buehler, R. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M. [Department of Physics and Astronomy, Clemson University, Kinard Lab of Physics, Clemson, SC 29634-0978 (United States); Atwood, W. B. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Axelsson, M. [Department of Physics, KTH Royal Institute of Technology, AlbaNova, SE-106 91 Stockholm (Sweden); Baldini, L. [Università di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa I-56127 Pisa (Italy); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D.; Buson, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bellazzini, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bhat, P. N. [Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Bissaldi, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, 70126 Bari (Italy); Bonino, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Torino, I-10125 Torino (Italy); Bottacini, E.; Caliandro, G. A.; Cameron, R. A. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Brandt, T. J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Bregeon, J. [Laboratoire Univers et Particules de Montpellier, Université Montpellier, CNRS/IN2P3, Montpellier (France); Bruel, P. [Laboratoire Leprince-Ringuet, École polytechnique, CNRS/IN2P3, Palaiseau (France); Anderson, B., E-mail: jchiang@slac.stanford.edu; and others

    2016-05-10

    We perform a comprehensive stacking analysis of data collected by the Fermi Large Area Telescope (LAT) of γ -ray bursts (GRBs) localized by the Swift spacecraft, which were not detected by the LAT but which fell within the instrument’s field of view at the time of trigger. We examine a total of 79 GRBs by comparing the observed counts over a range of time intervals to that expected from designated background orbits, as well as by using a joint likelihood technique to model the expected distribution of stacked counts. We find strong evidence for subthreshold emission at MeV to GeV energies using both techniques. This observed excess is detected during intervals that include and exceed the durations typically characterizing the prompt emission observed at keV energies and lasts at least 2700 s after the co-aligned burst trigger. By utilizing a novel cumulative likelihood analysis, we find that although a burst’s prompt γ -ray and afterglow X-ray flux both correlate with the strength of the subthreshold emission, the X-ray afterglow flux measured by Swift ’ s X-ray Telescope at 11 hr post trigger correlates far more significantly. Overall, the extended nature of the subthreshold emission and its connection to the burst’s afterglow brightness lend further support to the external forward shock origin of the late-time emission detected by the LAT. These results suggest that the extended high-energy emission observed by the LAT may be a relatively common feature but remains undetected in a majority of bursts owing to instrumental threshold effects.

  13. The capacity to retrieve escaped ER proteins extends to the trans-most cisterna of the Golgi stack.

    Science.gov (United States)

    Miesenböck, G; Rothman, J E

    1995-04-01

    To explore how far into the Golgi stack the capacity to retrieve KDEL proteins extends, we have introduced an exogenous probe (the peptide YHPNSTCSEKDEL) into the TGN of living cells. For this purpose, a CHO cell line expressing a c-myc-tagged version of the transmembrane protein TGN38--which cycles between the TGN and the cell surface--was generated. The cells internalized peptides that were disulfide bonded to anti-myc antibodies and accumulated the peptide-antibody complexes in the TGN. Peptides released from these complexes underwent retrograde transport to the ER, as evidenced by the transfer of N-linked carbohydrate to their acceptor site. The KDEL-tagged glycopeptides (approximately 10% of the endocytosed load) behaved like endogenous ER residents: they stayed intracellular, and their oligosaccharide side chains remained sensitive to endoglycosidase H. An option thus exists to extract ER residents even at the most distant pole of the Golgi stack, suggesting that sorting of resident from exported ER proteins may occur in a multistage process akin to fractional distillation.

  14. 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.

  15. Phosphorus and nitrogen losses from poultry litter stacks and leaching through soils

    Science.gov (United States)

    The practice of stacking poultry litter in fields prior to spreading provides important logistical benefits to farmers but is controversial due to its potential to serve as a source of nutrients to leachate and runoff. We evaluated nutrient fate under stacked poultry litter to assess differences in ...

  16. Measuring the effect of demagnetization in stacks of gadolinium plates using the magnetocaloric effect

    DEFF Research Database (Denmark)

    Lipsø, Hans Kasper Wigh; Nielsen, Kaspar Kirstein; Christensen, Dennis

    2011-01-01

    The effect of demagnetization in a stack of gadolinium plates is determined experimentally by using spatially resolved measurements of the adiabatic temperature change due to the magnetocaloric effect. The number of plates in the stack, the spacing between them and the position of the plate...

  17. Cfd Analysis of Heat Transfer in a Microtubular Solid Oxide Fuel Cell Stack

    Directory of Open Access Journals (Sweden)

    Pianko-Oprych Paulina

    2014-09-01

    Full Text Available The aim of this work was to achieve a deeper understanding of the heat transfer in a microtubular Solid Oxide Fuel Cell (mSOFC stack based on the results obtained by means of a Computational Fluid Dynamics tool. Stack performance predictions were based on simulations for a 16 anodesupported mSOFCs sub-stack, which was a component of the overall stack containing 64 fuel cells. The emphasis of the paper was put on steady-state modelling, which enabled identification of heat transfer between the fuel cells and air flow cooling the stack and estimation of the influence of stack heat losses. Analysis of processes for different heat losses and the impact of the mSOFC reaction heat flux profile on the temperature distribution in the mSOFC stack were carried out. Both radiative and convective heat transfer were taken into account in the analysis. Two different levels of the inlet air velocity and three different values of the heat losses were considered. Good agreement of the CFD model results with experimental data allowed to predict the operation trends, which will be a reliable tool for optimisation of the working setup and ensure sufficient cooling of the mSOFC stack.

  18. Methane Steam Reforming over an Ni-YSZ Solid Oxide Fuel Cell Anode in Stack Configuration

    DEFF Research Database (Denmark)

    Mogensen, David; Grunwaldt, Jan-Dierk; Hendriksen, Peter Vang

    2014-01-01

    The kinetics of catalytic steam reforming of methane over an Ni-YSZ anode of a solid oxide fuel cell (SOFC) have been investigated with the cell placed in a stack configuration. In order to decrease the degree of conversion, a single cell stack with reduced area was used. Measurements were...

  19. Plants with stacked genetically modified events: to assess or not to assess?

    DEFF Research Database (Denmark)

    Kok, Esther J.; Pedersen, Jan W.; Onori, Roberta

    2014-01-01

    of these differences relates to the so-called ‘stacked GM events’, that is, GMOs, plants so far, where new traits are combined by conventional crossing of different GM plants. This paper advocates rethinking the current food/feed safety assessment of stacked GM events in Europe based on an analysis of different...

  20. 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.

  1. 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

  2. Development Of A Solid Oxide Fuel Cell Stack By Delphi And Battelle

    Energy Technology Data Exchange (ETDEWEB)

    Mukerjee, Subhasish; Shaffer, Steven J.; Zizelman, James; Chick, Lawrence A.; Baskaran, Suresh; Chou, Y. S.; Coyle, Christopher A.; Deibler, John E.; Maupin, Gary D.; Meinhardt, Kerry D.; Paxton, Dean M.; Peters, Timothy J.; Sprenkle, Vince L.; Weil, K. Scott; Williford, Rick E.

    2003-01-20

    Delphi and Battelle are developing a Solid Oxide Fuel Cell (SOFC) stack for transportation and residential applications. This paper describes the status of development of the Generation 2 stack and key progress made in addressing some of the challenges in this technology.

  3. Durable SOC stacks for production of hydrogen and synthesis gas by high temperature electrolysis

    DEFF Research Database (Denmark)

    Ebbesen, Sune Dalgaard; Høgh, Jens Valdemar Thorvald; Nielsen, Karsten Agersted

    2011-01-01

    Electrolysis of steam and co-electrolysis of steam and carbon dioxide was studied in Solid Oxide Electrolysis Cell (SOEC) stacks composed of Ni/YSZ electrode supported SOECs. The results of this study show that long-term electrolysis is feasible without notable degradation in these SOEC stacks...

  4. Maximum supercurrent in two Josephson-junction stacks: Theory and experiment

    DEFF Research Database (Denmark)

    Carapella, G; Costabile, G; Sakai, S

    1998-01-01

    The interaction between two long Josephson junctions in a stack is investigated experimentally in the absence of applied magnetic field. Mutual interaction is observed when both junctions or only one junction in the stack is in the zero voltage state. To account for the observed phenomena we...... propose a model that takes into account the nonuniform self-fields generated by the bias currents....

  5. 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

  6. Test impact on the overall die-to-wafer 3D stacked IC cost

    NARCIS (Netherlands)

    Taouil, M.; Hamdioui, S.; Beenakker, K.; Marinissen, E.J.

    2011-01-01

    One of the key challenges in 3D Stacked-ICs (3D-SIC) is to guarantee high product quality at minimal cost. Quality is mostly determined by the applied tests and cost trade-offs. Testing 3D-SICs is very challenging due to several additional test moments for the mid-bond stacks, i.e., partially

  7. π-Stacking interactions between G-quartets and circulenes: A ...

    Indian Academy of Sciences (India)

    Abstract. Structures of planar and bowl-shaped circulenes as well as their stacks with G-quartet (G4) have been investigated through dispersion-corrected Density Functional Theory (DFT-D). The binding energies are substantial ∼10 kcal/mol with d ∼3.5 Å between the stacking rings. The calculations show that G4 binds ...

  8. 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)

  9. A method of measuring stacked objects volume based on laser sensing

    Science.gov (United States)

    Zhao, Qijie; Wu, Yijing; Li, Xianfa; Xu, Jiao; Meng, Qingxu

    2017-10-01

    Stacked objects volume measurement is now widely used in the fields of enterprise material management. It is significant to improve the efficiency of enterprise management and to reduce the cost of management and operation. The method based on laser sensing is one of the key methods to measure the stacked objects volume. This paper presents a laser sensing measurement method of stacked objects based on bottom plane extraction and real-time calibration. A calibration method for a laser scanning sensor and inertial measurement sensor is proposed. Three-dimensional reconstructions of stacked objects and volume calculations are carried out after acquisition and processing of point clouds. Volume measurement experiments of the single box and stacked boxes have been conducted respectively. Experimental results show that the measurement method is feasible and valid with good accuracy.

  10. 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

  11. 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.

  12. Efficient thin-film stack characterization using parametric sensitivity analysis for spectroscopic ellipsometry in semiconductor device fabrication

    International Nuclear Information System (INIS)

    Likhachev, D.V.

    2015-01-01

    During semiconductor device fabrication, control of the layer thicknesses is an important task for in-line metrology since the correct thickness values are essential for proper device performance. At the present time, ellipsometry is widely used for routine process monitoring and process improvement as well as characterization of various materials in the modern nanoelectronic manufacturing. The wide recognition of this technique is based on its non-invasive, non-intrusive and non-destructive nature, high measurement precision, accuracy and speed, and versatility to characterize practically all types of materials used in modern semiconductor industry (dielectrics, semiconductors, metals, polymers, etc.). However, it requires the use of one of the multi-parameter non-linear optimization methods due to its indirect nature. This fact creates a big challenge for analysis of multilayered structures since the number of simultaneously determined model parameters, for instance, thin film thicknesses and model variables related to film optical properties, should be restricted due to parameter cross-correlations. In this paper, we use parametric sensitivity analysis to evaluate the importance of various model parameters and to suggest their optimal search ranges. In this work, the method is applied practically for analysis of a few structures with up to five-layered film stack. It demonstrates an evidence-based improvement in accuracy of multilayered thin-film thickness measurements which suggests that the proposed approach can be useful for industrial applications. - Highlights: • An improved method for multilayered thin-film stack characterization is proposed. • The screening-type technique based on so-called “elementary effects” was employed. • The model parameters were ranked according to relative importance for model output. • The method is tested using two examples of complex thin-film stack characterization. • The approach can be useful in many practical

  13. Fault Localization Method by Partitioning Memory Using Memory Map and the Stack for Automotive ECU Software Testing

    Directory of Open Access Journals (Sweden)

    Kwanhyo Kim

    2016-09-01

    Full Text Available Recently, the usage of the automotive Electronic Control Unit (ECU and its software in cars is increasing. Therefore, as the functional complexity of such software increases, so does the likelihood of software-related faults. Therefore, it is important to ensure the reliability of ECU software in order to ensure automobile safety. For this reason, systematic testing methods are required that can guarantee software quality. However, it is difficult to locate a fault during testing with the current ECU development system because a tester performs the black-box testing using a Hardware-in-the-Loop (HiL simulator. Consequently, developers consume a large amount of money and time for debugging because they perform debugging without any information about the location of the fault. In this paper, we propose a method for localizing the fault utilizing memory information during black-box testing. This is likely to be of use to developers who debug automotive software. In order to observe whether symbols stored in the memory have been updated, the memory is partitioned by a memory map and the stack, thus the fault candidate region is reduced. A memory map method has the advantage of being able to finely partition the memory, and the stack method can partition the memory without a memory map. We validated these methods by applying these to HiL testing of the ECU for a body control system. The preliminary results indicate that a memory map and the stack reduce the possible fault locations to 22% and 19% of the updated memory, respectively.

  14. Stacked Autoencoders for the P300 Component Detection

    Directory of Open Access Journals (Sweden)

    Lukáš Vařeka

    2017-05-01

    Full Text Available Novel neural network training methods (commonly referred to as deep learning have emerged in recent years. Using a combination of unsupervised pre-training and subsequent fine-tuning, deep neural networks have become one of the most reliable classification methods. Since deep neural networks are especially powerful for high-dimensional and non-linear feature vectors, electroencephalography (EEG and event-related potentials (ERPs are one of the promising applications. Furthermore, to the authors' best knowledge, there are very few papers that study deep neural networks for EEG/ERP data. The aim of the experiments subsequently presented was to verify if deep learning-based models can also perform well for single trial P300 classification with possible application to P300-based brain-computer interfaces. The P300 data used were recorded in the EEG/ERP laboratory at the Department of Computer Science and Engineering, University of West Bohemia, and are publicly available. Stacked autoencoders (SAEs were implemented and compared with some of the currently most reliable state-of-the-art methods, such as LDA and multi-layer perceptron (MLP. The parameters of stacked autoencoders were optimized empirically. The layers were inserted one by one and at the end, the last layer was replaced by a supervised softmax classifier. Subsequently, fine-tuning using backpropagation was performed. The architecture of the neural network was 209-130-100-50-20-2. The classifiers were trained on a dataset merged from four subjects and subsequently tested on different 11 subjects without further training. The trained SAE achieved 69.2% accuracy that was higher (p < 0.01 than the accuracy of MLP (64.9% and LDA (65.9%. The recall of 58.8% was slightly higher when compared with MLP (56.2% and LDA (58.4%. Therefore, SAEs could be preferable to other state-of-the-art classifiers for high-dimensional event-related potential feature vectors.

  15. Analysis of NSTX Upgrade OH Magnet and Center Stack

    Energy Technology Data Exchange (ETDEWEB)

    A. Zolfaghari, P. Titus, J. Chrzanowski, A. Salehzadeh, F. Dahlgren

    2010-11-30

    The new ohmic heating (OH) coil and center stack for the National Spherical Torus Experiment (NSTX) upgrade are required to meet cooling and structural requirements for operation at the enhanced 1 Tesla toroidal field and 2 MA plasma current. The OH coil is designed to be cooled in the time between discharges by water flowing in the center of the coil conductor. We performed resistive heating and thermal hydraulic analyses to optimize coolant channel size to keep the coil temperature below 100 C and meet the required 20 minute cooling time. Coupled electromagnetic, thermal and structural FEA analyses were performed to determine if the OH coil meets the requirements of the structural design criteria. Structural response of the OH coil to its self-field and the field from other coils was analyzed. A model was developed to analyze the thermal and electromagnetic interaction of centerstack components such as the OH coil, TF inner legs and the Bellville washer preload mechanism. Torsional loads from the TF interaction with the OH and poloidal fields are transferred through the TF flag extensions via a torque transfer coupling to the rest of the tokamak structure. A 3D FEA analysis was performed to qualify this design. The results of these analyses, which will be presented in this paper, have led to the design of OH coil and centerstack components that meet the requirements of the NSTX-upgrade structural design criteria.

  16. SAR Target Recognition with Feature Fusion Based on Stacked Autoencoder

    Directory of Open Access Journals (Sweden)

    Kang Miao

    2017-04-01

    Full Text Available A feature fusion algorithm based on a Stacked AutoEncoder (SAE for Synthetic Aperture Rader (SAR imagery is proposed in this paper. Firstly, 25 baseline features and Three-Patch Local Binary Patterns (TPLBP features are extracted. Then, the features are combined in series and fed into the SAE network, which is trained by a greedy layer-wise method. Finally, the softmax classifier is employed to fine tune the SAE network for better fusion performance. Additionally, the Gabor texture features of SAR images are extracted, and the fusion experiments between different features are carried out. The results show that the baseline features and TPLBP features have low redundancy and high complementarity, which makes the fused feature more discriminative. Compared with the SAR target recognition algorithm based on SAE or CNN (Convolutional Neural Network, the proposed method simplifies the network structure and increases the recognition accuracy and efficiency. 10-classes SAR targets based on an MSTAR dataset got a classification accuracy up to 95.88%, which verifies the effectiveness of the presented algorithm.

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

    International Nuclear Information System (INIS)

    Petit, A.; Brie, M.

    1996-01-01

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

  18. Strontium titanate/silicon-based terahertz photonic crystal multilayer stack

    Energy Technology Data Exchange (ETDEWEB)

    Xin, J.Z.; Jim, K.L.; Tsang, Y.H.; Chan, H.L.W.; Leung, C.W. [Hong Kong Polytechnic University, Department of Applied Physics and Materials Research Centre, Kowloon, Hong Kong (China); Yang, J.; Gong, X.J.; Chen, L.Q.; Gao, F. [Chinese Academy of Sciences, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Shenzhen (China)

    2012-04-15

    A one-dimensional photonic crystal working in the terahertz (THz) range was designed and implemented. To facilitate the design, the transmission properties of strontium titanate crystals were characterized by THz-time-domain spectroscopy. Relatively high refractive index ({proportional_to}18.5) and transmission ratio (0.08) were observed between 0.2 to 1 THz. A stacked structure of (Si d{sub Si}/STO d{sub STO}){sub N} /Si d{sub Si} was then designed, with transmission spectra calculated by the transfer matrix method. The effects of the filling ratio (d{sub STO}/(d{sub Si}+d{sub STO})), periodicity (d{sub Si}+d{sub STO}) and the number of repeats N on the transmission of PC were investigated. The effect of introducing a defect layer was also studied. Based on these, Si/STO multilayers with STO defect thickness of 125 {mu}m and 200 {mu}m were measured. The shift of the defect mode was observed and compared with the calculations. (orig.)

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

    International Nuclear Information System (INIS)

    Rodgers, J.C.

    1987-11-01

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

  20. Mechanically Stacked Four-Junction Concentrator Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, Myles A.; Geisz, John F.; Ward, J. Scott; Garcia, Ivan; Friedman, Daniel J.; King, Richard R.; Chiu, Philip T.; France, Ryan M.; Duda, Anna; Olavarria, Waldo J.; Young, Michelle; Kurtz, Sarah R.

    2015-06-14

    Multijunction solar cells can be fabricated by bonding together component cells that are grown separately. Because the component cells are each grown lattice-matched to suitable substrates, this technique allows alloys of different lattice constants to be combined without the structural defects introduced when using metamorphic buffers. Here we present results on the fabrication and performance of four-junction mechanical stacks composed of GaInP/GaAs and GaInAsP/GaInAs tandems, grown on GaAs and InP substrates, respectively. The two tandems were bonded together with a low-index, transparent epoxy that acts as an omni-directional reflector to the GaAs bandedge luminescence, while simultaneously transmitting nearly all of the sub-bandgap light. As determined by electroluminescence measurements and optical modeling, the GaAs subcell demonstrates a higher internal radiative limit and thus higher subcell voltage, compared with GaAs subcells without enhanced internal optics; all four subcells exhibit excellent material quality. The device was fabricated with four contact terminals so that each tandem can be operated at its maximum power point, which raises the cumulative efficiency and decreases spectral sensitivity. Efficiencies exceeding 38% at one-sun have been demonstrated. Eliminating the series resistance is the key challenge for the concentrator cells. We will discuss the performance of one-sun and concentrator versions of the device, and compare the results to recently fabricated monolithic four-junction cells.

  1. Electrical characterization of vertically stacked p-FET SOI nanowires

    Science.gov (United States)

    Cardoso Paz, Bruna; Cassé, Mikaël; Barraud, Sylvain; Reimbold, Gilles; Vinet, Maud; Faynot, Olivier; Antonio Pavanello, Marcelo

    2018-03-01

    This work presents the performance and transport characteristics of vertically stacked p-type MOSFET SOI nanowires (NWs) with inner spacers and epitaxial growth of SiGe raised source/drain. The conventional procedure to extract the effective oxide thickness (EOT) and Shift and Ratio Method (S&R) have been adapted and validated through tridimensional numerical simulations. Electrical characterization is performed for NWs with [1 1 0]- and [1 0 0]-oriented channels, as a function of both fin width (WFIN) and channel length (L). Results show a good electrostatic control and reduced short channel effects (SCE) down to 15 nm gate length, for both orientations. Effective mobility is found around two times higher for [1 1 0]- in comparison to [1 0 0]-oriented NWs due to higher holes mobility contribution in (1 1 0) plan. Improvements obtained on ION/IOFF by reducing WFIN are mainly due to subthreshold slope decrease, once small and none mobility increase is obtained for [1 1 0]- and [1 0 0]-oriented NWs, respectively.

  2. Thickness Dependent Interlayer Magnetoresistance in Multilayer Graphene Stacks

    Directory of Open Access Journals (Sweden)

    S. C. Bodepudi

    2016-01-01

    Full Text Available Chemical Vapor Deposition grown multilayer graphene (MLG exhibits large out-of-plane magnetoresistance due to interlayer magnetoresistance (ILMR effect. It is essential to identify the factors that influence this effect in order to explore its potential in magnetic sensing and data storage applications. It has been demonstrated before that the ILMR effect is sensitive to the interlayer coupling and the orientation of the magnetic field with respect to the out-of-plane (c-axis direction. In this work, we investigate the role of MLG thickness on ILMR effect. Our results show that the magnitude of ILMR effect increases with the number of graphene layers in the MLG stack. Surprisingly, thicker devices exhibit field induced resistance switching by a factor of at least ~107. This effect persists even at room temperature and to our knowledge such large magnetoresistance values have not been reported before in the literature at comparable fields and temperatures. In addition, an oscillatory MR effect is observed at higher field values. A physical explanation of this effect is presented, which is consistent with our experimental scenario.

  3. Stacked microbial desalination cells to enhance water desalination efficiency.

    Science.gov (United States)

    Chen, Xi; Xia, Xue; Liang, Peng; Cao, Xiaoxin; Sun, Haotian; Huang, Xia

    2011-03-15

    Microbial desalination cell (MDC) is a new method to obtain clean water from brackish water using electricity generated from organic matters by exoelectrogenic bacteria. Anions and cations, derived from salt solution filled in the desalination chamber between the anode and cathode, move to the anode and cathode chambers under the force of electrical field, respectively. On the basis of the primitive single-desalination-chambered MDC, stacked microbial desalination cells (SMDCs) were developed in order to promote the desalination rate in the present study. The effects of desalination chamber number and external resistance were investigated. Results showed that a remarkable increase in the total desalination rate (TDR) could be obtained by means of increasing the desalination cell number and reducing the external resistance, which caused the charge transfer efficiency increased since the SMDCs enabled more pairs of ions separated while one electron passed through the external circuit. The maximum TDR of 0.0252 g/h was obtained using a two-desalination-chambered SMDC with an external resistance of 10 Ω, which was 1.4 times that of single-desalination-chambered MDC. SMDCs proved to be an effective approach to increase the total water desalination rate if provided a proper desalination chamber number and external resistance.

  4. High Power High Efficiency Diode Laser Stack for Processing

    Science.gov (United States)

    Gu, Yuanyuan; Lu, Hui; Fu, Yueming; Cui, Yan

    2018-03-01

    High-power diode lasers based on GaAs semiconductor bars are well established as reliable and highly efficient laser sources. As diode laser is simple in structure, small size, longer life expectancy with the advantages of low prices, it is widely used in the industry processing, such as heat treating, welding, hardening, cladding and so on. Respectively, diode laser could make it possible to establish the practical application because of rectangular beam patterns which are suitable to make fine bead with less power. At this power level, it can have many important applications, such as surgery, welding of polymers, soldering, coatings and surface treatment of metals. But there are some applications, which require much higher power and brightness, e.g. hardening, key hole welding, cutting and metal welding. In addition, High power diode lasers in the military field also have important applications. So all developed countries have attached great importance to high-power diode laser system and its applications. This is mainly due their low performance. In this paper we will introduce the structure and the principle of the high power diode stack.

  5. 3D stacked chips from emerging processes to heterogeneous systems

    CERN Document Server

    Fettweis, Gerhard

    2016-01-01

    This book explains for readers how 3D chip stacks promise to increase the level of on-chip integration, and to design new heterogeneous semiconductor devices that combine chips of different integration technologies (incl. sensors) in a single package of the smallest possible size.  The authors focus on heterogeneous 3D integration, addressing some of the most important challenges in this emerging technology, including contactless, optics-based, and carbon-nanotube-based 3D integration, as well as signal-integrity and thermal management issues in copper-based 3D integration. Coverage also includes the 3D heterogeneous integration of power sources, photonic devices, and non-volatile memories based on new materials systems.   •Provides single-source reference to the latest research in 3D optoelectronic integration: process, devices, and systems; •Explains the use of wireless 3D integration to improve 3D IC reliability and yield; •Describes techniques for monitoring and mitigating thermal behavior in 3D I...

  6. Stacking Ensemble Learning for Short-Term Electricity Consumption Forecasting

    Directory of Open Access Journals (Sweden)

    Federico Divina

    2018-04-01

    Full Text Available The ability to predict short-term electric energy demand would provide several benefits, both at the economic and environmental level. For example, it would allow for an efficient use of resources in order to face the actual demand, reducing the costs associated to the production as well as the emission of CO 2 . To this aim, in this paper we propose a strategy based on ensemble learning in order to tackle the short-term load forecasting problem. In particular, our approach is based on a stacking ensemble learning scheme, where the predictions produced by three base learning methods are used by a top level method in order to produce final predictions. We tested the proposed scheme on a dataset reporting the energy consumption in Spain over more than nine years. The obtained experimental results show that an approach for short-term electricity consumption forecasting based on ensemble learning can help in combining predictions produced by weaker learning methods in order to obtain superior results. In particular, the system produces a lower error with respect to the existing state-of-the art techniques used on the same dataset. More importantly, this case study has shown that using an ensemble scheme can achieve very accurate predictions, and thus that it is a suitable approach for addressing the short-term load forecasting problem.

  7. Supramolecular helical stacking of metallomesogens derived from enantiopure and racemic polycatenar oxazolines.

    Science.gov (United States)

    Barberá, Joaquín; Cavero, Emma; Lehmann, Matthias; Serrano, José-Luis; Sierra, Teresa; Vázquez, Jesús T

    2003-04-16

    The present report undertakes a challenge of general interest in supramolecular chemistry: the achievement of helical organizations with controlled structure. To achieve this target we considered the possibility of inducing supramolecular chirality using molecules that were designed to organize into columnar mesophases. The use of oxazoline-derived ligands and metal coordination served as tools to prepare molecules with a phasmidic-like structure, which show columnar organization in the liquid crystalline state. To ensure the formation of chiral mesophases, these complexes bear stereogenic centers in the rigid coordination environment of the metal. X-ray and circular dichroism experiments have revealed that chirality transfer does indeed take place from the chiral molecule to the columnar liquid crystal organization. This chiral columnar organization appears as a helix consisting of stacks of molecules that rotate with respect to one another along the column while maintaining their mean planes parallel to each other. In fact, it has been concluded that packing of these polycatenar molecules must be more efficient upon rotation of a molecule with respect to the adjacent one along the column. Furthermore, the same type of helical supraorganization has been found to be present in the mesophase of the racemic mixture and the mixture of diastereomers prepared from the racemic ligand. In this case, segregation of the optical isomers is proposed to occur to give rise to both types of helix (right-handed and left-handed).

  8. A Smart City Lighting Case Study on an OpenStack-Powered Infrastructure

    Directory of Open Access Journals (Sweden)

    Giovanni Merlino

    2015-07-01

    Full Text Available The adoption of embedded systems, mobile devices and other smart devices keeps rising globally, and the scope of their involvement broadens, for instance, in smart city-like scenarios. In light of this, a pressing need emerges to tame such complexity and reuse as much tooling as possible without resorting to vertical ad hoc solutions, while at the same time taking into account valid options with regard to infrastructure management and other more advanced functionalities. Existing solutions mainly focus on core mechanisms and do not allow one to scale by leveraging infrastructure or adapt to a variety of scenarios, especially if actuators are involved in the loop. A new, more flexible, cloud-based approach, able to provide device-focused workflows, is required. In this sense, a widely-used and competitive framework for infrastructure as a service, such as OpenStack, with its breadth in terms of feature coverage and expanded scope, looks to fit the bill, replacing current application-specific approaches with an innovative application-agnostic one. This work thus describes the rationale, efforts and results so far achieved for an integration of IoT paradigms and resource ecosystems with such a kind of cloud-oriented device-centric environment, by focusing on a smart city scenario, namely a park smart lighting example, and featuring data collection, data visualization, event detection and coordinated reaction, as example use cases of such integration.

  9. A Smart City Lighting Case Study on an OpenStack-Powered Infrastructure.

    Science.gov (United States)

    Merlino, Giovanni; Bruneo, Dario; Distefano, Salvatore; Longo, Francesco; Puliafito, Antonio; Al-Anbuky, Adnan

    2015-07-06

    The adoption of embedded systems, mobile devices and other smart devices keeps rising globally, and the scope of their involvement broadens, for instance, in smart city-like scenarios. In light of this, a pressing need emerges to tame such complexity and reuse as much tooling as possible without resorting to vertical ad hoc solutions, while at the same time taking into account valid options with regard to infrastructure management and other more advanced functionalities. Existing solutions mainly focus on core mechanisms and do not allow one to scale by leveraging infrastructure or adapt to a variety of scenarios, especially if actuators are involved in the loop. A new, more flexible, cloud-based approach, able to provide device-focused workflows, is required. In this sense, a widely-used and competitive framework for infrastructure as a service, such as OpenStack, with its breadth in terms of feature coverage and expanded scope, looks to fit the bill, replacing current application-specific approaches with an innovative application-agnostic one. This work thus describes the rationale, efforts and results so far achieved for an integration of IoT paradigms and resource ecosystems with such a kind of cloud-oriented device-centric environment, by focusing on a smart city scenario, namely a park smart lighting example, and featuring data collection, data visualization, event detection and coordinated reaction, as example use cases of such integration.

  10. Substituent Effects in π-Stacking of Histidine on Functionalized-SWNT and Graphene.

    Science.gov (United States)

    Tian, Ge; Li, Huifang; Ma, Wanyong; Wang, Yixuan

    2015-06-15

    Adsorptions of histidine on the functionalized (10,0) single-walled carbon nanotube (SWNT) and graphene were investigated using density function theory methods, M05-2x and DFT-D. The results show that the binding of the histidine ring to the functionalized SWNT is weaker than that to the pristine SWNT for both singlet and triplet complexes, regardless of the electron-donating (-OH, -NH 2 ) or electron-withdrawing (-COOH) character and their attached sites. The present decreased binding is opposite to the well-known enhanced binding in the substituted benzene dimers. Since the atoms of the histidine are distant from the substituent atoms by over 6Å, there would be no direct interaction between histidine and the substituent as in the case of the substituted benzene systems. The decreased binding can be mainly driven by the aromaticity of the functionalized SWNT. The nucleus-independent chemical shift (NICS) index analysis for the functionalized SWNTs in deed shows that local aromaticity of SWNT is decreased because of the electron redistribution induced by functional groups, and the π-π stacking between the histidine ring and functionalized -SWNT is therefore decreased as compared to the pristine SWNT. However, the above trend does not remain for the binding between the histidine and graphene. The binding of the histidine to the functionalized graphene with -OH and -NH 2 is just slightly weaker than that to the pristine graphene, while its binding to COOH-SWNT becomes a little bit stronger.

  11. A Smart City Lighting Case Study on an OpenStack-Powered Infrastructure

    Science.gov (United States)

    Merlino, Giovanni; Bruneo, Dario; Distefano, Salvatore; Longo, Francesco; Puliafito, Antonio; Al-Anbuky, Adnan

    2015-01-01

    The adoption of embedded systems, mobile devices and other smart devices keeps rising globally, and the scope of their involvement broadens, for instance, in smart city-like scenarios. In light of this, a pressing need emerges to tame such complexity and reuse as much tooling as possible without resorting to vertical ad hoc solutions, while at the same time taking into account valid options with regard to infrastructure management and other more advanced functionalities. Existing solutions mainly focus on core mechanisms and do not allow one to scale by leveraging infrastructure or adapt to a variety of scenarios, especially if actuators are involved in the loop. A new, more flexible, cloud-based approach, able to provide device-focused workflows, is required. In this sense, a widely-used and competitive framework for infrastructure as a service, such as OpenStack, with its breadth in terms of feature coverage and expanded scope, looks to fit the bill, replacing current application-specific approaches with an innovative application-agnostic one. This work thus describes the rationale, efforts and results so far achieved for an integration of IoT paradigms and resource ecosystems with such a kind of cloud-oriented device-centric environment, by focusing on a smart city scenario, namely a park smart lighting example, and featuring data collection, data visualization, event detection and coordinated reaction, as example use cases of such integration. PMID:26153775

  12. Segmenting Brain Tissues from Chinese Visible Human Dataset by Deep-Learned Features with Stacked Autoencoder

    Directory of Open Access Journals (Sweden)

    Guangjun Zhao

    2016-01-01

    Full Text Available Cryosection brain images in Chinese Visible Human (CVH dataset contain rich anatomical structure information of tissues because of its high resolution (e.g., 0.167 mm per pixel. Fast and accurate segmentation of these images into white matter, gray matter, and cerebrospinal fluid plays a critical role in analyzing and measuring the anatomical structures of human brain. However, most existing automated segmentation methods are designed for computed tomography or magnetic resonance imaging data, and they may not be applicable for cryosection images due to the imaging difference. In this paper, we propose a supervised learning-based CVH brain tissues segmentation method that uses stacked autoencoder (SAE to automatically learn the deep feature representations. Specifically, our model includes two successive parts where two three-layer SAEs take image patches as input to learn the complex anatomical feature representation, and then these features are sent to Softmax classifier for inferring the labels. Experimental results validated the effectiveness of our method and showed that it outperformed four other classical brain tissue detection strategies. Furthermore, we reconstructed three-dimensional surfaces of these tissues, which show their potential in exploring the high-resolution anatomical structures of human brain.

  13. Batch Image Encryption Using Generated Deep Features Based on Stacked Autoencoder Network

    Directory of Open Access Journals (Sweden)

    Fei Hu

    2017-01-01

    Full Text Available Chaos-based algorithms have been widely adopted to encrypt images. But previous chaos-based encryption schemes are not secure enough for batch image encryption, for images are usually encrypted using a single sequence. Once an encrypted image is cracked, all the others will be vulnerable. In this paper, we proposed a batch image encryption scheme into which a stacked autoencoder (SAE network was introduced to generate two chaotic matrices; then one set is used to produce a total shuffling matrix to shuffle the pixel positions on each plain image, and another produces a series of independent sequences of which each is used to confuse the relationship between the permutated image and the encrypted image. The scheme is efficient because of the advantages of parallel computing of SAE, which leads to a significant reduction in the run-time complexity; in addition, the hybrid application of shuffling and confusing enhances the encryption effect. To evaluate the efficiency of our scheme, we compared it with the prevalent “logistic map,” and outperformance was achieved in running time estimation. The experimental results and analysis show that our scheme has good encryption effect and is able to resist brute-force attack, statistical attack, and differential attack.

  14. Three-Dimensional Microwave Imaging for Concealed Weapon Detection Using Range Stacking Technique

    Directory of Open Access Journals (Sweden)

    Weixian Tan

    2017-01-01

    Full Text Available Three-dimensional (3D microwave imaging has been proven to be well suited for concealed weapon detection application. For the 3D image reconstruction under two-dimensional (2D planar aperture condition, most of current imaging algorithms focus on decomposing the 3D free space Green function by exploiting the stationary phase and, consequently, the accuracy of the final imagery is obtained at a sacrifice of computational complexity due to the need of interpolation. In this paper, from an alternative viewpoint, we propose a novel interpolation-free imaging algorithm based on wavefront reconstruction theory. The algorithm is an extension of the 2D range stacking algorithm (RSA with the advantages of low computational cost and high precision. The algorithm uses different reference signal spectrums at different range bins and then forms the target functions at desired range bin by a concise coherent summation. Several practical issues such as the propagation loss compensation, wavefront reconstruction, and aliasing mitigating are also considered. The sampling criterion and the achievable resolutions for the proposed algorithm are also derived. Finally, the proposed method is validated through extensive computer simulations and real-field experiments. The results show that accurate 3D image can be generated at a very high speed by utilizing the proposed algorithm.

  15. Marginalised Stacked Denoising Autoencoders for Robust Representation of Real-Time Multi-View Action Recognition

    Directory of Open Access Journals (Sweden)

    Feng Gu

    2015-07-01

    Full Text Available Multi-view action recognition has gained a great interest in video surveillance, human computer interaction, and multimedia retrieval, where multiple cameras of different types are deployed to provide a complementary field of views. Fusion of multiple camera views evidently leads to more robust decisions on both tracking multiple targets and analysing complex human activities, especially where there are occlusions. In this paper, we incorporate the marginalised stacked denoising autoencoders (mSDA algorithm to further improve the bag of words (BoWs representation in terms of robustness and usefulness for multi-view action recognition. The resulting representations are fed into three simple fusion strategies as well as a multiple kernel learning algorithm at the classification stage. Based on the internal evaluation, the codebook size of BoWs and the number of layers of mSDA may not significantly affect recognition performance. According to results on three multi-view benchmark datasets, the proposed framework improves recognition performance across all three datasets and outputs record recognition performance, beating the state-of-art algorithms in the literature. It is also capable of performing real-time action recognition at a frame rate ranging from 33 to 45, which could be further improved by using more powerful machines in future applications.

  16. Generalized uniform formulae for atmospheric dispersion of activities released from a ventilation stack or from a leaky reactor building

    International Nuclear Information System (INIS)

    Vlachovsky, K.; Veverka, O.; Valenta, V.

    1976-01-01

    Relations are given for the calculation of the atmospheric transport and dispersion of industrial gaseous wastes released from the stacks of factories, power plants and nuclear power plants. Modified formulae are derived for stack disposal from a small stack, also applicable in calculating the gaseous waste release from a leaky reactor. Uniform generalized formulae are presented serving the calculation of both high and short stack disposals as well as of reactor building leakages. (L.O.)

  17. A new method to determine earthquake depth: stacking multiple-station autocorrelogram

    Science.gov (United States)

    Zhang, M.; Tian, D.; Wen, L.

    2013-12-01

    Accurate determination of source depth of the earthquakes in the crust is still challenging, because of our imperfect knowledge of velocity structure and unclear depth phase of the earthquakes. We develop a new method to determine earthquake source depth, based on stacking multiple-station autocorrelogram (SMAC). We determine source depth using both direct SH wave and its coda. In coda wave interferometry, the stacking of the cross-correlograms of two earthquake coda can be treated as the Green's function from one earthquake to the other. The stacking of the autocorrelograms of an earthquake coda can thus be treated as the Green's function from the earthquake to itself. By stacking autocorrelograms of SH wave coda recorded at each station, we retrieve the surface reflection from the source and back to the source, which is used to determine the source depth. In the stacking of direct wave autocorrelograms, the time difference between the surface reflection and the main wave would depend on source depth, Moho depth and epicentral distance. We derive travel time difference between the surface reflection and the main SH wave by grid-searching those parameters. The autocorrelograms are stacked along the theoretical travel times predicted based on each source depth, Moho depth and epicentral distance. The source depth in the set of the parameters that gives the most prominent stacking energy is regarded as the best-fitting source depth. We demonstrate the validity of SMAC in both synthetics and actual data for an earthquake occurring in Japan Island.

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

    Science.gov (United States)

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

    2018-05-01

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

  19. 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.

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

    International Nuclear Information System (INIS)

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

    1995-06-01

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

  1. 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

  2. Towards further understanding of stacking fault tetrahedron absorption and defect-free channels – A molecular dynamics study

    International Nuclear Information System (INIS)

    Fan, Haidong; El-Awady, Jaafar A.; Wang, Qingyuan

    2015-01-01

    Highlights: • Stacking fault tetrahedron (SFT) is fully absorbed by screw dislocation. • Absorbed SFT becomes moveable with the aid of Lomer dislocations. • Finally SFT is removed from the specimen or from defect-free channels. • Two scenarios responsible for the formation of defect-free channels were proposed. - Abstract: The mechanisms leading to stacking fault tetrahedron (SFT) absorption via interactions with dislocations, and subsequent formation of plastic flow localization in defect-free channels, which were frequently observed in irradiated materials in transmission electron microscopy experiments, are still unclear. To address this, screw dislocation interactions with SFTs in copper were investigated using molecular dynamics (MD) simulations. The interaction details reveal that a screw dislocation can fully absorb an SFT through the thermally activated transformation of Lomer–Cottrell lock into Lomer dislocations. After absorption, almost all the vacancies in the SFT are transferred into Lomer dislocations, which are able to move transversely under complex loading conditions. As a result, SFTs can be removed from the material (for SFTs near surface) or from defect-free channels (for SFTs in the bulk) with the aid of Lomer dislocations. In addition, it was shown that this absorption process is favorable only at high temperature, low applied shear stress and/or high SFT density. These results are in good agreement with in situ TEM observations. The current simulations and analyses provide useful insights into the formation mechanisms of defect-free channels in irradiated materials

  3. Influence of fluvial sandstone architecture on geothermal energy production

    NARCIS (Netherlands)

    Willems, C.J.L.; Maghami Nick, Hamidreza M.; Weltje, G.J.; Donselaar, M.E.; Bruhn, D.F.

    2015-01-01

    Fluvial sandstone reservoirs composed of stacked meander belts are considered as potential geothermal resources in the Netherlands. Net-to-gross, orientation and stacking pattern of the channel belts is of major importance for the connectivity between the injection and production well in such

  4. Classifier Subset Selection for the Stacked Generalization Method Applied to Emotion Recognition in Speech

    Science.gov (United States)

    Álvarez, Aitor; Sierra, Basilio; Arruti, Andoni; López-Gil, Juan-Miguel; Garay-Vitoria, Nestor

    2015-01-01

    In this paper, a new supervised classification paradigm, called classifier subset selection for stacked generalization (CSS stacking), is presented to deal with speech emotion recognition. The new approach consists of an improvement of a bi-level multi-classifier system known as stacking generalization by means of an integration of an estimation of distribution algorithm (EDA) in the first layer to select the optimal subset from the standard base classifiers. The good performance of the proposed new paradigm was demonstrated over different configurations and datasets. First, several CSS stacking classifiers were constructed on the RekEmozio dataset, using some specific standard base classifiers and a total of 123 spectral, quality and prosodic features computed using in-house feature extraction algorithms. These initial CSS stacking classifiers were compared to other multi-classifier systems and the employed standard classifiers built on the same set of speech features. Then, new CSS stacking classifiers were built on RekEmozio using a different set of both acoustic parameters (extended version of the Geneva Minimalistic Acoustic Parameter Set (eGeMAPS)) and standard classifiers and employing the best meta-classifier of the initial experiments. The performance of these two CSS stacking classifiers was evaluated and compared. Finally, the new paradigm was tested on the well-known Berlin Emotional Speech database. We compared the performance of single, standard stacking and CSS stacking systems using the same parametrization of the second phase. All of the classifications were performed at the categorical level, including the six primary emotions plus the neutral one. PMID:26712757

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    Yu Kong

    2014-01-01

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

  7. Interactive display of stacks of images in scientific presentations with PowerPoint.

    Science.gov (United States)

    Gniadek, Thomas J; Desjardins, Benoit

    2004-09-01

    We describe a new tool to facilitate the creation and interactive display of stacks of images for scientific and educational presentations using Microsoft PowerPoint. This new tool allows interactive scrolling through stacks of images. After a presentation is created, all elements required to display the stacks of images are embedded in the PowerPoint file. These presentations can be run on any computer (Macintosh or IBM-compatible versions) using PowerPoint with no other preinstalled software, making this tool useful for scientific and educational presentations at national and international meetings.

  8. 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...... (one for pickups and one for deliveries) using only one container. Repacking is not allowed, instead each item can be positioned in one of several rows in the container, such that each row can be considered a LIFO (last in, first out) stack, but no mutual constraints exist between the rows. Two...

  9. 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.

  10. Solid Oxide Cell and Stack Testing, Safety and Quality Assurance (SOCTESQA)

    DEFF Research Database (Denmark)

    Auer, C.; Lang, M.; Couturier, K.

    2015-01-01

    The market penetration of fuel and electrolysis cell energy systems in Europe requires the development of reliable assessment, testing and prediction of performance and durability of solid oxide cells and stacks (SOC). To advance in this field the EU-project “SOCTESQA” was launched in May 2014....... Partners from different countries in Europe and one external party from Singapore are working together to develop uniform and industry wide test procedures and protocols for SOC cell/stack assembly. In this project new application fields which are based on the operation of the SOC cell/stack assembly...

  11. 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...

  12. Diffuse scattering in random-stacking hexagonal close-packed crystals of colloidal hard spheres

    Science.gov (United States)

    Byelov, Dmytro V.; Hilhorst, Jan; Reinink, Anke B. G. M. Leferink op; Snigireva, Irina; Snigirev, Anatoly; Vaughan, Gavin B. M.; Portale, Giuseppe; Petukhov, Andrei V.

    2010-02-01

    Microradian X-ray diffraction from sedimentary colloidal crystals is studied using synchrotron radiation with photon energies of 12.4, 27, and 38 keV. Stacking disorder in these hard-sphere crystals leads to diffuse X-ray scattering along the Bragg scattering rods normal to the randomly stacked layers. We observed the appearance of diffuse scattering, shown to be induced by multiple scattering, along the secondary Bragg rods in between the stacking-independent true Bragg reflections. This effect can be reduced by measuring at higher X-ray energies.

  13. Thermodynamic and critical properties of an antiferromagnetically stacked triangular Ising antiferromagnet in a field

    Science.gov (United States)

    Žukovič, M.; Borovský, M.; Bobák, A.

    2018-05-01

    We study a stacked triangular lattice Ising model with both intra- and inter-plane antiferromagnetic interactions in a field, by Monte Carlo simulation. We find only one phase transition from a paramagnetic to a partially disordered phase, which is of second order and 3D XY universality class. At low temperatures we identify two highly degenerate phases: at smaller (larger) fields the system shows long-range ordering in the stacking direction (within planes) but not in the planes (stacking direction). Nevertheless, crossovers to these phases do not have a character of conventional phase transitions but rather linear-chain-like excitations.

  14. Quantitative review of degradation and lifetime of solid oxide cells and stacks

    DEFF Research Database (Denmark)

    Skafte, Theis Løye; Hjelm, Johan; Blennow, Peter

    2016-01-01

    A comprehensive review of degradation and lifetime for solid oxide cells and stacks hasbeen conducted. Based on more than 50 parameters from 150 publications and 1 000 000hours of accumulated testing, this paper presents a quantitative analysis of the currentinternational status of degradation...... updating by thecommunity is encouraged. Furthermore, the commonly reported test parameters anddegradation indicators are discussed. The difficulty in standardizing testing due tovariations in cell and stack design, materials and intended purpose of the system isacknowledged. A standardization of reporting...... of long-term single-cell- and stack-tests isproposed....

  15. 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.

  16. 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.

  17. Interfacing HTCondor-CE with OpenStack

    Science.gov (United States)

    Bockelman, B.; Caballero Bejar, J.; Hover, J.

    2017-10-01

    Over the past few years, Grid Computing technologies have reached a high level of maturity. One key aspect of this success has been the development and adoption of newer Compute Elements to interface the external Grid users with local batch systems. These new Compute Elements allow for better handling of jobs requirements and a more precise management of diverse local resources. However, despite this level of maturity, the Grid Computing world is lacking diversity in local execution platforms. As Grid Computing technologies have historically been driven by the needs of the High Energy Physics community, most resource providers run the platform (operating system version and architecture) that best suits the needs of their particular users. In parallel, the development of virtualization and cloud technologies has accelerated recently, making available a variety of solutions, both commercial and academic, proprietary and open source. Virtualization facilitates performing computational tasks on platforms not available at most computing sites. This work attempts to join the technologies, allowing users to interact with computing sites through one of the standard Computing Elements, HTCondor-CE, but running their jobs within VMs on a local cloud platform, OpenStack, when needed. The system will re-route, in a transparent way, end user jobs into dynamically-launched VM worker nodes when they have requirements that cannot be satisfied by the static local batch system nodes. Also, once the automated mechanisms are in place, it becomes straightforward to allow an end user to invoke a custom Virtual Machine at the site. This will allow cloud resources to be used without requiring the user to establish a separate account. Both scenarios are described in this work.

  18. Four-Dimensional Lung Treatment Planning in Layer-Stacking Carbon Ion Beam Treatment: Comparison of Layer-Stacking and Conventional Ungated/Gated Irradiation

    International Nuclear Information System (INIS)

    Mori, Shinichiro; Kanematsu, Nobuyuki; Asakura, Hiroshi; Sharp, Gregory C.; Kumagai, Motoki; Dobashi, Suguru; Nakajima, Mio; Yamamoto, Naoyoshi; Kandatsu, Susumu; Baba, Masayuki

    2011-01-01

    Purpose: We compared four-dimensional (4D) layer-stacking and conventional carbon ion beam distribution in the treatment of lung cancer between ungated and gated respiratory strategies using 4DCT data sets. Methods and Materials: Twenty lung patients underwent 4DCT imaging under free-breathing conditions. Using planning target volumes (PTVs) at respective respiratory phases, two types of compensating bolus were designed, a full single respiratory cycle for the ungated strategy and an approximately 30% duty cycle for the exhalation-gated strategy. Beams were delivered to the PTVs for the ungated and gated strategies, PTV(ungated) and PTV(gated), respectively, which were calculated by combining the respective PTV(Tn)s by layer-stacking and conventional irradiation. Carbon ion beam dose distribution was calculated as a function of respiratory phase by applying a compensating bolus to 4DCT. Accumulated dose distributions were calculated by applying deformable registration. Results: With the ungated strategy, accumulated dose distributions were satisfactorily provided to the PTV, with D95 values for layer-stacking and conventional irradiation of 94.0% and 96.2%, respectively. V20 for the lung and Dmax for the spinal cord were lower with layer-stacking than with conventional irradiation, whereas Dmax for the skin (14.1 GyE) was significantly lower (21.9 GyE). In addition, dose conformation to the GTV/PTV with layer-stacking irradiation was better with the gated than with the ungated strategy. Conclusions: Gated layer-stacking irradiation allows the delivery of a carbon ion beam to a moving target without significant degradation of dose conformity or the development of hot spots.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-01

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

  20. Principal Components Analysis (PCA) Image used to characterize the complexity of the seafloor around St. John, USVI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Eight complexity surfaces (mean depth, standard deviation of depth, curvature, plan curvature, profile curvature, rugosity, slope, and slope of slope) were stacked...

  1. Charge-transfer complexes from decamethylferrocene and 1,4-quinone derivatives: neutral-ionic phase diagrams for metallocene complexes.

    Science.gov (United States)

    Mochida, Tomoyuki; Funasako, Yusuke; Azumi, Hiroko

    2011-09-28

    Charge-transfer (CT) complexes of ferrocenes with 1,4-quinone derivatives were investigated. Deca- and octamethylferrocene complexes with 1,4-naphthoquinone derivatives were prepared and structurally characterized; these were neutral 1:2 DA complexes with mixed-stack structures. The formation of complexes with 1,4-benzoquinones was examined by applying solvent-drop grinding. CT energies and phase transitions in these neutral and other ionic complexes were investigated. Their electronic states are discussed on the basis of the phase diagrams derived for mixed-stack ferrocene-based CT complexes, taking into account their dependence on the DA ratio, dimensionality, and intermolecular interactions. This journal is © The Royal Society of Chemistry 2011

  2. 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

  3. New routes to library success 100+ ideas from outside the stacks

    CERN Document Server

    Doucett, Elisabeth

    2015-01-01

    An exciting survey of creativity in action, Doucett's book will encourage public library directors, managers, trustees, and staff to cross-pollinate their own expertise with innovative ideas from outside the stacks.

  4. Characterisation of a Planar Solid Oxide Cell Stack Operated at Elevated Pressure

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Graves, Christopher R.; Chen, Ming

    2016-01-01

    be operated either as electrolysers (SOEC) to convert electricity to fuels such as hydrogen or methane, and as fuel cells (SOFC) to convert fuels to electricity. Both productivity and conversion efficiency can be improved if the SOC operation pressure can be increased from ambient pressure to 10-30 bar. Here...... we characterize an SOC stack operated at pressures from ambient pressure to 10 bar without fluctuations in the steam supply. The pressure dependency of stack temperature, cell area specific resistance (ASR), current-voltage (iV) curves, stack impedance spectra and pressure drop across the stack...... and heat exchangers is analyzed and the expected impact of pressurization on the hydrogen production cost is evaluated....

  5. Characterization of a Planar Solid Oxide Cell Stack Operated at Elevated Pressure

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Graves, Christopher R.; Chen, Ming

    2016-01-01

    be operated either as electrolyzers (SOEC) to convert electricity to fuels such as hydrogen or methane, and as fuel cells (SOFC) to convert fuels to electricity. Both productivity and conversion efficiency can be improved if the SOC operation pressure can be increased from ambient pressure to 10–30 bar....... In this paper we characterize an SOC stack operated at pressures from ambient pressure to 10 bar. The pressure dependency of stack temperature, cell area specific resistance (ASR), current-voltage (iV) curves, stack impedance spectra and pressure drop across the stack and heat exchangers is analyzed...... in this paper. Additionally, the expected impact on the hydrogen production efficiency and cost is discussed....

  6. 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.

  7. 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

  8. Structural and quantum chemical analysis of exciton coupling in homo- and heteroaggregate stacks of merocyanines

    Science.gov (United States)

    Bialas, David; Zitzler-Kunkel, André; Kirchner, Eva; Schmidt, David; Würthner, Frank

    2016-01-01

    Exciton coupling is of fundamental importance and determines functional properties of organic dyes in (opto-)electronic and photovoltaic devices. Here we show that strong exciton coupling is not limited to the situation of equal chromophores as often assumed. Quadruple dye stacks were obtained from two bis(merocyanine) dyes with same or different chromophores, respectively, which dimerize in less-polar solvents resulting in the respective homo- and heteroaggregates. The structures of the quadruple dye stacks were assigned by NMR techniques and unambiguously confirmed by single-crystal X-ray analysis. The heteroaggregate stack formed from the bis(merocyanine) bearing two different chromophores exhibits remarkably different ultraviolet/vis absorption bands compared with those of the homoaggregate of the bis(merocyanine) comprising two identical chromophores. Quantum chemical analysis based on an extension of Kasha's exciton theory appropriately describes the absorption properties of both types of stacks revealing strong exciton coupling also between different chromophores within the heteroaggregate. PMID:27680284

  9. Stack Memory Implementation and Analysis of Timing Constraint, Power and Memory using FPGA

    DEFF Research Database (Denmark)

    Pandey, Nisha; Pandey, Bishwajeet; Thind, Vandana

    2017-01-01

    Abstract— in this work of analysis, stack memory algorithm is implemented on a number of FPGA platforms like virtex4, virtex5, virtex6, virtex6 low power and virtex7 low voltage and very detailed observations/investigations were made about timing constraint, memory and power dissipation. The main...... real-time output, so that source used to realize the project is not wasted and get an energy efficient design. However, Stack memory is an approach in which information is entered and deleted from the stack memory segment in the pattern of last in first out mechanism. There are several ways...... of implementation of stack memory algorithm but virtex4 and virtex7 low voltage were considered to be the most efficient platforms for its operation. The developed system is energy efficient as the algorim ensures less memory utilization, less power consumption and short time for signal travel....

  10. Methane Steam Reforming over an Ni-YSZ Solid Oxide Fuel Cell Anode in Stack Configuration

    Directory of Open Access Journals (Sweden)

    D. Mogensen

    2014-01-01

    Full Text Available The kinetics of catalytic steam reforming of methane over an Ni-YSZ anode of a solid oxide fuel cell (SOFC have been investigated with the cell placed in a stack configuration. In order to decrease the degree of conversion, a single cell stack with reduced area was used. Measurements were performed in the temperature range 600–800°C and the partial pressures of all reactants and products were varied. The obtained rates could be well fitted with a power law expression (r ∝PCH40.7. A simple model is presented which is capable of predicting the methane conversion in a stack configuration from intrinsic kinetics of the anode support material. The predictions are compared with the stack measurements presented here, and good agreement is observed.

  11. Stack Memory Implementation and Analysis of Timing Constraint, Power and Memory using FPGA

    DEFF Research Database (Denmark)

    Thind, Vandana; Pandey, Nisha; Pandey, Bishwajeet

    2017-01-01

    of implementation of stack memory algorithm but virtex4 and virtex7 low voltage were considered to be the most efficient platforms for its operation. The developed system is energy efficient as the algorim ensures less memory utilization, less power consumption and short time for signal travel.......Abstract— in this work of analysis, stack memory algorithm is implemented on a number of FPGA platforms like virtex4, virtex5, virtex6, virtex6 low power and virtex7 low voltage and very detailed observations/investigations were made about timing constraint, memory and power dissipation. The main...... real-time output, so that source used to realize the project is not wasted and get an energy efficient design. However, Stack memory is an approach in which information is entered and deleted from the stack memory segment in the pattern of last in first out mechanism. There are several ways...

  12. Limestone/adipic acid FGD and stack opacity reduction pilot plant tests at Big Rivers

    Energy Technology Data Exchange (ETDEWEB)

    Laslo, D.; Bakke, E.; Chisholm, E.

    1984-01-01

    Big Rivers Electric Corporation (BREC) contracted Peabody Process Systems, Inc. (PPSI) to install a flue gas cleaning (FGC) pilot plant at the BREC R.D. Green Station Unit No. 2 located at Sebree, KY. A six month test program was completed demonstrating technology for: alternatives to using lime as an alkali; methods for improving cake dewatering; identification of the causes of high stack opacity; and methods for the reduction of high stack opacity. This paper presents highlights extracted from the reports submitted by PPSI to BREC on this test program. BREC was primarily interested in reduction of operating costs, if possible, by using an alkali less expensive than lime, and by improving the poor dewatering characteristic inherent in a dolomitic lime system. BREC was also within compliance for particulate emissions and opacity in the duct after the dry electrostatic precipitator, but not in compliance with the stack opacity regulation, and therefore wanted to investigate methods for stack opacity reduction.

  13. Mercury Dispersion Modeling And Purge Ventilation Stack Height Determination For Tank 40H

    Energy Technology Data Exchange (ETDEWEB)

    Rivera-Giboyeaux, A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-05-19

    The SRNL Atmospheric Technologies Group performed an analysis for mercury emissions from H-Tank Farm - Tank 40 ventilation system exhaust in order to assess whether the Short Term Exposure Limit (STEL), or Threshold Limit Value (TLV) levels for mercury will be exceeded during bulk sludge slurry mixing and sludge removal operations. The American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) was used as the main dispersion modelling tool for this analysis. The results indicated that a 45-foot stack is sufficient to raise the plume centerline from the Tank 40 release to prevent mercury exposure problems for any of the stack discharge scenarios provided. However, a 42-foot stack at Tank 40 is sufficient to prevent mercury exposure concerns in all emission scenarios except the 50 mg/m3 release. At a 42-foot stack height, values exceeding the exposure standards are only measured on receptors located above 34 feet.

  14. 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....... The temperature is predicted in these three parts, where they also are measured. The heat balance of the system involves a fuel cell model to describe the heat added by the fuel cells when a current is drawn. Furthermore the model also predicts the temperatures when heating the stack with external heating...... elements for start-up, heat 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....

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

    International Nuclear Information System (INIS)

    Lesnoj, S.

    1998-01-01

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

  16. ORELA data acquisition system hardware. Vol. 6. Eight-stage stacking buffer memory (Q-5066)

    International Nuclear Information System (INIS)

    Wintenberg, R.E.; Reynolds, J.W.

    1977-01-01

    A Stacking Buffer Memory for de-randomizing data on high data rate experiments at ORELA is documented by a description of operation, mechanical details of design, and a detailed theory of operation illustrated through six examples of operation

  17. Magnetism of an adatom on biased AA-stacked bilayer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, Yawar, E-mail: yawar.mohammadi@gmail.com [Department of Physics, Islamic Azad University, Kermanshah Branch, Kermanshah (Iran, Islamic Republic of); Moradian, Rostam [Department of Physics, Razi University, Kermanshah (Iran, Islamic Republic of); Nano Science and Nano Technology Research Center, Razi University, Kermanshah (Iran, Islamic Republic of)

    2014-06-01

    We study the magnetism of an adatom adsorbed on AA-stacked bilayer graphene (BLG) in both unbiased and biased cases using the Anderson impurity model. We find different magnetic phase diagrams for the adatom, depending on its energy level. The magnetic phase of the adatom varies from that in normal metals to that in graphene. This is because of the individual energy dependence of the density of states (DOS) of AA-stacked BLG and anomalous broadening of the adatom energy level. We also investigate the effect of a bias voltage on the DOS of AA-stacked BLG and show that adatom magnetization can be controlled by applying a bias voltage. This allows the possibility of using AA-stacked BLG in spintronic devices.

  18. 21 CFR 866.2440 - Automated medium dispensing and stacking device.

    Science.gov (United States)

    2010-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2440... stacking device is a device intended for medical purposes to dispense a microbiological culture medium into...

  19. Fabrication of highly porous LSM/CGO cell stacks for electrochemical flue gas purification

    DEFF Research Database (Denmark)

    Andersen, Kjeld Bøhm; Bræstrup, Frantz Radzik; Kammer Hansen, Kent

    2013-01-01

    In this study porous cell stacks for electrochemical flue gas purification were fabricated using tape casting and lamination followed by sintering. Two different mixtures of pore formers were used; either a mixture of two types of graphite or a mixture of graphite with polymethyl methacrylate micro-particles....... It was shown that the porous cell stacks fabricated with polymethyl methacrylate had a higher porosity but a similar back pressure compared to the porous cell stacks fabricated with only graphite as a pore former. This was due to a high back pressure of the electrolyte layer. The porous cell stacks fabricated...... with polymethyl methacrylate as a pore former seem to be well suited for i.e. caption of soot particles. Furthermore, the back pressure of the electrode layer was significantly reduced when using polymethyl methacrylate pore formers. However, a better interconnectivity of the pores formed by the polymethyl...

  20. Stacking fault domains as sources of a-type threading dislocations in III-nitride heterostructures

    Science.gov (United States)

    Smalc-Koziorowska, J.; Bazioti, C.; Albrecht, M.; Dimitrakopulos, G. P.

    2016-02-01

    A mechanism for the nucleation of a-type threading dislocation half-loops from basal stacking faults in wurtzite III-nitride heterostructures is presented. Transmission electron microscopy observations, in conjunction with topological and strain analysis, show that there are two possible configurations of closed domains comprising basal stacking faults of I1 type. It is shown that the lattice dislocation may emanate when the sphalerite structural units of the stacking faults in the closed domain are oriented in a parallel manner. The closed domain configurations do not introduce any shift on the basal planes, resulting in zero defect content along the growth direction. The stacking fault domains are hexagonal, with sides along the ⟨ 10 1 ¯ 0 ⟩ directions, and the threading dislocation half loops nucleate at the line nodes. The mechanism was found to be operational in multiple III-nitride systems.