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Sample records for staggered herringbone channels

  1. Efficient gas-liquid contact using microfluidic membrane devices with staggered herringbone mixers.

    Science.gov (United States)

    Femmer, Tim; Eggersdorfer, Max L; Kuehne, Alexander J C; Wessling, Matthias

    2015-08-07

    We describe a novel membrane based gas-liquid-contacting device with increased mass transport and reduced pressure loss by combining a membrane with a staggered herringbone static mixer. Herringbone structures are imposed on the microfluidic channel geometry via soft lithography, acting as mixers which introduce secondary flows at the membrane interface. Such flows include Dean vortices and Taylor flows generating effective mixing while improving mass transport and preventing concentration polarization in microfluidic channels. Furthermore, our static herringbone mixer membranes effectively reduce pressure losses leading to devices with enhanced transfer properties for microfluidic gas-liquid contact. We investigate the red blood cell distribution to tailor our devices towards miniaturised extracorporeal membrane oxygenation and improved comfort of patients with lung insufficiencies.

  2. Operation of direct channel microchannel plates in the ''herringbone'' scheme

    International Nuclear Information System (INIS)

    Sorokin, O.M.

    1982-01-01

    Operation of two series connection microchannel plates (MCP) in the monoelectron mode is investigat4eed. MCP of 0.8 mm thick and having 28 mm diameter were investigated. The channel cross section is equal to approximately μm, channel angle is 7 deg. A formula for the noise power factor in the mode of channel saturation is derived. The experimental data processing by collector pulse amplitude distribution results in the conclusion on possibility of sharp drop of MCP amplification noise factor at transition into the saturation mode. Shown is the principal possibility of obtaining the amplitude resolution up to 0.05 and on the base of it - application of ''herringbone'' scheme as an amplitude detector. A possibility of detecting 1-, 2-, 3- and 4-electron photoemission events in the ultraviolet spectrum region with < or approximately 5% resolution is illustrated. It is shown that the ''herringbone'' scheme is comparatively simple in operation despite a centain difficulty in gap regulation and it does require superhigh vacuum or fine technology and it is stable in operation at the pressure of approximately 0, 3 mPa

  3. Realization of a passive micromixer using herringbone structure

    Science.gov (United States)

    Whulanza, Yudan; Utomo, Muhammad S.; Hilman, Adam

    2018-02-01

    Micromixing is an important research area for a variety of applications in sensing and diagnostics. In this paper, we are trying to develop an overall understanding of the process of mixing by allowing two fluid flows to flow through various asymmetrical structures. We have successfully realized and compared the performance of different passive micromixer designs based on the idea of staggered herringbone micromixer. The herringbone structure is expected to affect the flow rate. We design few microchannels using varieties on velocity, height and distance between herringbone. The layout of the structure is based on the staggered herringbone bilayers where the layer is positioned on the bottom wall of the microchannel. From simulation and experiment, it is known that the height of the channel and herringbone structure affect the flow, and the most effective height of the main channel and herringbone structure is 0.3 and 0.14 mm (2:1 ratio).

  4. Power module assemblies with staggered coolant channels

    Science.gov (United States)

    Herron, Nicholas Hayden; Mann, Brooks S; Korich, Mark D

    2013-07-16

    A manifold is provided for supporting a power module assembly with a plurality of power modules. The manifold includes a first manifold section. The first face of the first manifold section is configured to receive the first power module, and the second face of the first manifold section defines a first cavity with a first baseplate thermally coupled to the first power module. The first face of the second manifold section is configured to receive the second power module, and the second face of the second manifold section defines a second cavity with a second baseplate thermally coupled to the second power module. The second face of the first manifold section and the second face of the second manifold section are coupled together such that the first cavity and the second cavity form a coolant channel. The first cavity is at least partially staggered with respect to second cavity.

  5. Microfluidic Manufacturing of Polymeric Nanoparticles: Comparing Flow Control of Multiscale Structure in Single-Phase Staggered Herringbone and Two-Phase Reactors.

    Science.gov (United States)

    Xu, Zheqi; Lu, Changhai; Riordon, Jason; Sinton, David; Moffitt, Matthew G

    2016-12-06

    We compare the microfluidic manufacturing of polycaprolactone-block-poly(ethylene oxide) (PCL-b-PEO) nanoparticles (NPs) in a single-phase staggered herringbone (SHB) mixer and in a two-phase gas-liquid segmented mixer. NPs generated from two different copolymer compositions in both reactors and at three different flow rates, along with NPs generated using a conventional bulk method, are compared with respect to morphologies, dimensions, and internal crystallinities. Our work, the first direct comparison between alternate microfluidic NP synthesis methods, shows three key findings: (i) NP morphologies and dimensions produced in the bulk are different from those produced in a microfluidic mixer, whereas NP crystallinities produced in the bulk and in the SHB mixer are similar; (ii) NP morphologies, dimensions, and crystallinities produced in the single-phase SHB and two-phase mixers at the lowest flow rate are similar; and (iii) NP morphologies, dimensions, and crystallinities change with flow rate in the two-phase mixer but not in the single-phase SHB mixer. These findings provide new insights into the relative roles of mixing and shear in the formation and flow-directed processing of polymeric NPs in microfluidics, informing future reactor designs for manufacturing NPs of low polydispersity and controlled multiscale structure and function.

  6. Effect of wall proximity of two staggered triangular cylinders on the transport process in a channel

    Directory of Open Access Journals (Sweden)

    Mousa Farhadi

    2016-09-01

    Full Text Available A numerical investigation has been carried out to analyze the heat transfer and the flow field around two isothermal triangular cylinders of equal size placed staggered in a horizontal plane channel with adiabatic walls. Computations have been carried out for Reynolds numbers (based on triangle width 100, 250, and 350, lateral gap ratios (d/B 0, 0.5, and 1, and longitudinal gap ratios (S/B 1, 2, 3 and 4. The effect of longitudinal and lateral gap between obstacles and proximity of channel walls is investigated. Results show that when obstacles are placed in close vicinity of the channel's wall (d/B = 1, vortex shedding disappears at the downstream of triangles at Re = 100 and 250 at all S/B, but for Re = 350 creating and disappearing of the vortex shedding depend on the longitudinal gap ratio (S/B. Proximity of obstacles has more effect on the second triangle than the first triangle especially from longitudinal gap ratio equals 2, so that with approaching the channel wall, the Nusselt number for the first triangle decreases, while for the second triangle a different behavior is seen. Staggered arrangement causes the Nusselt number of the second triangle to become greater than the first triangle.

  7. Experimental study of heat transfer and pressures drops for cans with spiral herring-bone fins

    International Nuclear Information System (INIS)

    Pelce, J.; Francois, S.; Houseaux, O.; Pierre, B.

    1964-01-01

    Cans fitted with herring-bone fins are used for cooling uranium in certain nuclear reactor. By herring-bone is meant a staggered arrangement of the fins which have a plane of symmetry parallel to the general direction of liquid flow. The main geometrical parameter are then: the number of fins, the number of herring-bones, the angle of inclination of the fins with respect to the can axis, the dimensions of the fins, the can diameter and the channel diameter. The research is essentially experimental. The test are of three types: full size tests, in conditions approaching those in the reactor (constant flux, CO 2 under pressure); full size tests but with a constant wall temperature, much easier to set up, and intended to distinguish rapidly between the merits of the various types of can; large-scale tests with air at atmospheric pressure for studying the phenomena in more detail. For each can tried out there is a corresponding pressure drop coefficient, a mean thermal exchange coefficient Mo-bar and a minimum exchange coefficient Mo min and Mo-bar are related by the expression Mo min = Mo-bar * f c * f, where f c and f are respectively circumferential and longitudinal singularity factor determined from a statistical study of all the temperatures measured for each can. The results are presented in about thirty tables and figures the most noteworthy results being summarized in the conclusion. (authors) [fr

  8. Joint Interference Alignment and Power Allocation for K-User Multicell MIMO Channel through Staggered Antenna Switching.

    Science.gov (United States)

    Selvaprabhu, Poongundran; Chinnadurai, Sunil; Sarker, Md Abdul Latif; Lee, Moon Ho

    2018-01-28

    In this paper, we characterise the joint interference alignment (IA) and power allocation strategies for a K -user multicell multiple-input multiple-output (MIMO) Gaussian interference channel. We consider a MIMO interference channel with blind-IA through staggered antenna switching on the receiver. We explore the power allocation and feasibility condition for cooperative cell-edge (CE) mobile users (MUs) by assuming that the channel state information is unknown. The new insight behind the transmission strategy of the proposed scheme is premeditated (randomly generated transmission strategy) and partial cooperative CE MUs, where the transmitter is equipped with a conventional antenna, the receiver is equipped with a reconfigurable multimode antenna (staggered antenna switching pattern), and the receiver switches between preset T modes. Our proposed scheme assists and aligns the desired signals and interference signals to cancel the common interference signals because the received signal must have a corresponding independent signal subspace. The capacity for a K -user multicell MIMO Gaussian interference channel with reconfigurable multimode antennas is completely characterised. Furthermore, we show that the proposed K -user multicell MIMO scheduling and K -user L -cell CEUs partial cooperation algorithms elaborate the generalisation of K -user IA and power allocation strategies. The numerical results demonstrate that the proposed intercell interference scheme with partial-cooperative CE MUs achieves better capacity and signal-to-interference plus noise ratio (SINR) performance compared to noncooperative CE MUs and without intercell interference schemes.

  9. Joint Interference Alignment and Power Allocation for K-User Multicell MIMO Channel through Staggered Antenna Switching

    Directory of Open Access Journals (Sweden)

    Poongundran Selvaprabhu

    2018-01-01

    Full Text Available In this paper, we characterise the joint interference alignment (IA and power allocation strategies for a K-user multicell multiple-input multiple-output (MIMO Gaussian interference channel. We consider a MIMO interference channel with blind-IA through staggered antenna switching on the receiver. We explore the power allocation and feasibility condition for cooperative cell-edge (CE mobile users (MUs by assuming that the channel state information is unknown. The new insight behind the transmission strategy of the proposed scheme is premeditated (randomly generated transmission strategy and partial cooperative CE MUs, where the transmitter is equipped with a conventional antenna, the receiver is equipped with a reconfigurable multimode antenna (staggered antenna switching pattern, and the receiver switches between preset T modes. Our proposed scheme assists and aligns the desired signals and interference signals to cancel the common interference signals because the received signal must have a corresponding independent signal subspace. The capacity for a K-user multicell MIMO Gaussian interference channel with reconfigurable multimode antennas is completely characterised. Furthermore, we show that the proposed K-user multicell MIMO scheduling and K-user L-cell CEUs partial cooperation algorithms elaborate the generalisation of K-user IA and power allocation strategies. The numerical results demonstrate that the proposed intercell interference scheme with partial-cooperative CE MUs achieves better capacity and signal-to-interference plus noise ratio (SINR performance compared to noncooperative CE MUs and without intercell interference schemes.

  10. Periodically fully developed laminar flow and heat transfer in a two-dimensional horizontal channel with staggered fins

    Directory of Open Access Journals (Sweden)

    Turgut Oğuz

    2017-01-01

    Full Text Available The 2-D periodically fully developed laminar forced convection fluid flow and heat transfer characteristics in a horizontal channel with staggered fins are investigated numerically under constant wall heat flux boundary condition. Study is performed using ANSYS Fluent 6.3.26 which uses finite volume method. Air (Pr @ 0.7 and Freon-12 (Pr @ 3.5 are used as working fluids. Effects of Reynolds number, Prandtl number, fin height, and distances between two fins on heat transfer and friction factor are examined. Results are given in the form of non-dimensional average Nusselt number and average Darcy friction factor as a function of Reynolds number for different fin distances and Prandtl numbers. The velocity and temperature profiles are also obtained. It is seen that as the fin distance increases, behavior approaches the finless channel, as expected. Also, thermal enhancement factors are given graphically for working fluids. It is seen that heat transfer dominates the friction as both the distance between two fins and Prandtl number increase. It is also seen that fins having blockage ratio of 0.10 in 2-D periodically fully developed laminar flow is not advantageous in comparison to smooth channel without fins.

  11. Flow over bio-inspired 3D herringbone wall riblets

    Science.gov (United States)

    Chen, Huawei; Rao, Fugang; Shang, Xiaopeng; Zhang, Deyuan; Hagiwara, Ichiro

    2014-03-01

    Under the inspiration of small riblets of shark skin, the microgroove drag reduction riblets whose direction set along fluid flow have been widely investigated. Herringbone-type riblets of bird flight feather are seldom exploited although bird also has excellent flight performance. Inspired from the flight feather, novel bio-inspired plane-3D (p-3D) and spatial-3D (s-3D) herringbone wall riblets are proposed. Through experiment measurement of drag reduction in water tunnel, maximum drag reduction of p-3D and s-3D herringbone riblets was about 17 and 20 %, higher than traditional microgroove riblets. Moreover, significant change of drag reduction was also found by change of the angle between herringbone riblets. In particular, maximum drag reduction occurred as angle between herringbone riblets was about 60° close to real flight feather, which indicates that microstructure of bird flight feather has great impact on flight performance.

  12. Levitation and locomotion on an air-table of plates with herringbone grooves

    Science.gov (United States)

    Hinch, John; de Maleprade, Helene

    2017-11-01

    Recent experiments in ESPCI in Paris and numerical simulations in Nano- and Microfluidics in Darmstadt have shown that plates with herringbone grooves in their base are accelerated on an air-table in the direction that the chevron grooves point. A simple two-dimensional model is constructed of the air flow down a channel with pressure controlled influx across the lower boundary. Limiting cases are considered of low and high Reynolds numbers, and of small and large pressure drop down the channel compared with the pressure drop across the porous plate. The levitation and locomotion forces are calculated. A prediction is made for the locomotive acceleration which avoids the complications of the shorter grooves which exit the front and back edges.

  13. Developing the EFL Students’ Reading Comprehension By Employing Herringbone Technique

    Directory of Open Access Journals (Sweden)

    Yunisrina Qismullah Yusuf

    2016-11-01

    Full Text Available This research aims to find out whether Herringbone Technique can developEFL students’ reading comprehension or not, especially in finding the main idea and supporting details in a recount text. The literature notes that Herringbone is known to be one of the techniques that can helpstudents to find important information and main idea in a text by seeking for answers on six comprehension questions on a diagram, viewed such as a fish’s skeleton. The sample of this research was 30 second grade junior high school students. The researchers employed simple random sampling to choose the sample. It further used the quantitative experimental approach with the pre-experimental design in the form of one group pre-test-post-test design.Pre-test was given before treatments, while post-test was given after the students were taught reading by using the Herringbone Technique. Each pre-test and post-test consisted of ten questions. The statistical formulas were used to analyze the data from the students tests’ scores. The mean score of pre-test was 59 and the post-test was 76. Futhermore, the result of t-test was 10.15, while the critical value of 0.05 significant level was 2.045, with the degree of freedom of 29. Since t-test (10.15 was higher than t-table (2.045, this study concludes that this technique could increase the EFL students’ reading comprehension.Despite in practice the researchers found that this technique decreased the students’ efforts in note-taking, however it did not inhibited them in obtaining improved scores in their reading tests.

  14. Experimental study of heat transfer and pressures drops for cans with spiral herring-bone fins; Etude experimentale du transfert de chaleur et des pertes de charges des gaines a ailettes helicoidales en chevron

    Energy Technology Data Exchange (ETDEWEB)

    Pelce, J.; Francois, S.; Houseaux, O.; Pierre, B. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    Cans fitted with herring-bone fins are used for cooling uranium in certain nuclear reactor. By herring-bone is meant a staggered arrangement of the fins which have a plane of symmetry parallel to the general direction of liquid flow. The main geometrical parameter are then: the number of fins, the number of herring-bones, the angle of inclination of the fins with respect to the can axis, the dimensions of the fins, the can diameter and the channel diameter. The research is essentially experimental. The test are of three types: full size tests, in conditions approaching those in the reactor (constant flux, CO{sub 2} under pressure); full size tests but with a constant wall temperature, much easier to set up, and intended to distinguish rapidly between the merits of the various types of can; large-scale tests with air at atmospheric pressure for studying the phenomena in more detail. For each can tried out there is a corresponding pressure drop coefficient, a mean thermal exchange coefficient Mo-bar and a minimum exchange coefficient Mo{sub min} and Mo-bar are related by the expression Mo{sub min} = Mo-bar * f{sub c} * f, where f{sub c} and f are respectively circumferential and longitudinal singularity factor determined from a statistical study of all the temperatures measured for each can. The results are presented in about thirty tables and figures the most noteworthy results being summarized in the conclusion. (authors) [French] Les gaines a ailettes en chevron sont utilisees pour le refroidissement de l'uranium dans certains reacteurs nucleaires. Par chevron, on entend une disposition alternee des ailettes ayant un plan de symetrie parallele a la direction generale de l'ecoulement fluide. Les principaux parametres geometriques sont alors: le nombre des ailettes, le nombre de chevrons, l'angle d'inclinaison des ailettes par rapport a l'axe de la gaine, les dimensions des ailettes, le diametre de la gaine et le diametre du canal. L

  15. Modeling and Analysis of the Static Characteristics and Dynamic Responses of Herringbone-grooved Thrust Bearings

    Science.gov (United States)

    Yu, Yunluo; Pu, Guang; Jiang, Kyle

    2017-12-01

    This paper describes a theoretical investigation of static and dynamic characteristics of herringbone-grooved air thrust bearings. Firstly, Finite Difference Method (FDM) and Finite Volume Method (FVM) are used in combination to solve the non-linear Reynolds equation and to find the pressure distribution of the film and the total loading capacity of the bearing. The influence of design parameters on air film gap characteristics, including the air film thickness, depth of the groove and rotating speed, are analyzed based on the FDM model. The simulation results show that hydrostatic thrust bearings can achieve a better load capacity with less air consumption than herringbone grooved thrust bearings at low compressibility number; herringbone grooved thrust bearings can achieve a higher load capacity but with more air consumption than hydrostatic thrust bearing at high compressibility number; herringbone grooved thrust bearings would lose stability at high rotating speeds, and the stability increases with the depth of the grooves.

  16. Staggering but not knocked out

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2012-11-01

    Italy's PV market is staggering like a boxer almost knocked out. It has been hit hard by the country's deep economic recession. Conto Energia V has been yet another blow with cuts of up to 40 % in the solar feed-in tariffs. But the situation is not hopeless.

  17. Taste changing in staggered quarks

    International Nuclear Information System (INIS)

    Quentin Mason

    2004-01-01

    The authors present results from a systematic perturbative investigation of taste-changing in improved staggered quarks. They show one-loop taste-changing interactions can be removed perturbatively by an effective four-quark term and calculate the necessary coefficients

  18. On staggered indecomposable Virasoro modules

    International Nuclear Information System (INIS)

    Kytoelae, Kalle; Ridout, David

    2009-06-01

    In this article, certain indecomposable Virasoro modules are studied. Specifically, the Virasoro mode L0 is assumed to be non-diagonalisable, possessing Jordan blocks of rank two. Moreover, the module is further assumed to have a highest weight submodule, the ''left module'', and that the quotient by this submodule yields another highest weight module, the ''right module''. Such modules, which have been called staggered, have appeared repeatedly in the logarithmic conformal field theory literature, but their theory has not been explored in full generality. Here, such a theory is developed for the Virasoro algebra using rather elementary techniques. The focus centres on two different but related questions typically encountered in practical studies: How can one identify a given staggered module, and how can one demonstrate the existence of a proposed staggered module. Given just the values of the highest weights of the left and right modules, themselves subject to simple necessary conditions, invariants are defined which together with the knowledge of the left and right modules uniquely identify a staggered module. The possible values of these invariants form a vector space of dimension zero, one or two, and the structures of the left and right modules limit the isomorphism classes of the corresponding staggered modules to an affine subspace (possibly empty). The number of invariants and affine restrictions is purely determined by the structures of the left and right modules. Moreover, in order to facilitate applications, the expressions for the invariants and restrictions are given by formulae as explicit as possible (they generally rely on expressions for Virasoro singular vectors). Finally, the text is liberally peppered throughout with examples illustrating the general concepts. These have been carefully chosen for their physical relevance or for the novel features they exhibit. (orig.)

  19. On staggered indecomposable Virasoro modules

    Science.gov (United States)

    Kytölä, Kalle; Ridout, David

    2009-12-01

    In this article, certain indecomposable Virasoro modules are studied. Specifically, the Virasoro mode L0 is assumed to be nondiagonalizable, possessing Jordan blocks of rank 2. Moreover, the module is further assumed to have a highest weight submodule, the "left module," and that the quotient by this submodule yields another highest weight module, the "right module." Such modules, which have been called staggered, have appeared repeatedly in the logarithmic conformal field theory literature, but their theory has not been explored in full generality. Here, such a theory is developed for the Virasoro algebra using rather elementary techniques. The focus centers on two different but related questions typically encountered in practical studies: How can one identify a given staggered module, and how can one demonstrate the existence of a proposed staggered module. Given just the values of the highest weights of the left and right modules, themselves subject to simple necessary conditions, invariants are defined which together with the knowledge of the left and right modules uniquely identify a staggered module. The possible values of these invariants form a vector space of dimension 0, 1, or 2, and the structures of the left and right modules limit the isomorphism classes of the corresponding staggered modules to an affine subspace (possibly empty). The number of invariants and affine restrictions is purely determined by the structures of the left and right modules. Moreover, in order to facilitate applications, the expressions for the invariants and restrictions are given by formulas as explicit as possible (they generally rely on expressions for Virasoro singular vectors). Finally, the text is liberally peppered throughout with examples illustrating the general concepts. These have been carefully chosen for their physical relevance or for the novel features they exhibit.

  20. On staggered indecomposable Virasoro modules

    Energy Technology Data Exchange (ETDEWEB)

    Kytoelae, Kalle [Geneve Univ. (Switzerland); Ridout, David [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2009-06-15

    In this article, certain indecomposable Virasoro modules are studied. Specifically, the Virasoro mode L0 is assumed to be non-diagonalisable, possessing Jordan blocks of rank two. Moreover, the module is further assumed to have a highest weight submodule, the ''left module'', and that the quotient by this submodule yields another highest weight module, the ''right module''. Such modules, which have been called staggered, have appeared repeatedly in the logarithmic conformal field theory literature, but their theory has not been explored in full generality. Here, such a theory is developed for the Virasoro algebra using rather elementary techniques. The focus centres on two different but related questions typically encountered in practical studies: How can one identify a given staggered module, and how can one demonstrate the existence of a proposed staggered module. Given just the values of the highest weights of the left and right modules, themselves subject to simple necessary conditions, invariants are defined which together with the knowledge of the left and right modules uniquely identify a staggered module. The possible values of these invariants form a vector space of dimension zero, one or two, and the structures of the left and right modules limit the isomorphism classes of the corresponding staggered modules to an affine subspace (possibly empty). The number of invariants and affine restrictions is purely determined by the structures of the left and right modules. Moreover, in order to facilitate applications, the expressions for the invariants and restrictions are given by formulae as explicit as possible (they generally rely on expressions for Virasoro singular vectors). Finally, the text is liberally peppered throughout with examples illustrating the general concepts. These have been carefully chosen for their physical relevance or for the novel features they exhibit. (orig.)

  1. Numerical analysis and comparison of three types of herringbone frame structure for highway subgrade slopes protection

    Science.gov (United States)

    Nie, Yihua; Tang, Saiqian; Xu, Yang; Mao, Kunli

    2018-04-01

    In order to obtain mechanical response distribution of herringbone frame structure for highway subgrade slopes protection and select the best structure type, 3D numerical models of three types herringbone frame structure were established and analyzed in finite element software ANSYS. Indoor physical model of soil slope protected by herringbone frame structure was built and mechanical response of the frame structure was measured by loading tests. Numerical results indicate slope foot is the stress most disadvantageous location. Comparative analysis shows that structure composed of mortar rubble base layer and precast concrete blocks paving layer is the best one for resisting deformation and structure with cement mortar base layer and precast concrete blocks paving layer is the best one for being of low stress.

  2. Fin-and-tube heat exchanger enhancement with a combined herringbone and vortex generator design

    DEFF Research Database (Denmark)

    Välikangas, Turo; Singh, Shobhana; Sørensen, Kim

    2018-01-01

    Vortex generators (VGs) are the most commonly investigated enhancement methods in the field of improved heat exchangers. The aim of present work is to study the effect of VGs in a fin-and-tube heat exchanger (FTHE) with herringbone fin shape. The delta winglet VG design with length (s) and height...... (H) is selected based on previous studies. The investigated VG design is simple and considered realistic from the manufacturing point of view. The combined enhancement with herringbone fin and the VG is evaluated by simulating the conjugate heat transfer and the air flow. The structured mesh...... transfer in the herringbone fin but also decrease the pressure drop. The highest and longest investigated VG design is found to perform the best because of its ability to delay the flow detachment from the tube, to feed high kinetic energy flow to the recirculation zone and to create longitudinal vortices...

  3. Staggering towards a calculation of weak amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Sharpe, S.R.

    1988-09-01

    An explanation is given of the methods required to calculate hadronic matrix elements of the weak Hamiltonians using lattice QCD with staggered fermions. New results are presented for the 1-loop perturbative mixing of the weak interaction operators. New numerical techniques designed for staggered fermions are described. A preliminary result for the kaon B parameter is presented. 24 refs., 3 figs.

  4. Staggering towards a calculation of weak amplitudes

    International Nuclear Information System (INIS)

    Sharpe, S.R.

    1988-09-01

    An explanation is given of the methods required to calculate hadronic matrix elements of the weak Hamiltonians using lattice QCD with staggered fermions. New results are presented for the 1-loop perturbative mixing of the weak interaction operators. New numerical techniques designed for staggered fermions are described. A preliminary result for the kaon B parameter is presented. 24 refs., 3 figs

  5. Tool kit for staggered fermions

    International Nuclear Information System (INIS)

    Kilcup, G.W.; Sharpe, S.R.

    1986-01-01

    The symmetries of staggered fermions are analyzed both discrete and continuous. Tools are presented that allow a simple decomposition of representations of the continuum symmetries into representations of the discrete lattice symmetries, both at zero and non-zero spatial momenta. These tools are used to find the lattice transcriptions of the operators that appear in the weak interaction Hamiltonian. The lattice Ward Identities are derived that follow from the single partially conserved axial symmetry. Using these identities, the lattice equivalents of the continuum PCAC relations are found. Combining all these tools, Ward Identities are obtained, for the matrix elements of the weak interaction Hamiltonian, from which the behavior of the matrix elements as the pion and kaon masses vanish are derived. The same behavior as in the continuum is found

  6. The Influence of Herringbone Technique Towards the Reading Comprehension of the Second Year Students of SMPN 4 Siak Hulu

    OpenAIRE

    Yuzulia, Irza; ', Mahdum Ph. D; ', Eliwarti, M. App.ling

    2017-01-01

    This pre-experimental research aimed to find out whether there is significant influence of students' reading comprehension after using Herringbone Technique in teaching reading at the second year of SMPN 4 Siak Hulu. Thus, the problem to be discussed is whether or not there is any significant influence of the students' reading comprehension after using Herringbone Technique in teaching reading at the second year of SMPN 4 Siak Hulu. The design of the research was one group pretest-posttest de...

  7. Bifurcation analysis of an aerodynamic journal bearing system considering the effect of stationary herringbone grooves

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.-C. [Department of Mechanical Engineering, Far East College, 49, Hsin-Shih, Tainan 744, Taiwan (China)]. E-mail: ccwang@cc.fec.edu.tw

    2007-08-15

    This paper investigates the bifurcation and nonlinear behavior of an aerodynamic journal bearing system taking into account the effect of stationary herringbone grooves. A finite difference method based on the successive over relation approach is employed to solve the Reynolds' equation. The analysis reveals a complex dynamical behavior comprising periodic and quasi-periodic responses of the rotor center. The dynamic behavior of the bearing system varies with changes in the bearing number and rotor mass. The results of this study provide a better understanding of the nonlinear dynamics of aerodynamic grooved journal bearing systems.

  8. Bifurcation analysis of an aerodynamic journal bearing system considering the effect of stationary herringbone grooves

    International Nuclear Information System (INIS)

    Wang, C.-C.

    2007-01-01

    This paper investigates the bifurcation and nonlinear behavior of an aerodynamic journal bearing system taking into account the effect of stationary herringbone grooves. A finite difference method based on the successive over relation approach is employed to solve the Reynolds' equation. The analysis reveals a complex dynamical behavior comprising periodic and quasi-periodic responses of the rotor center. The dynamic behavior of the bearing system varies with changes in the bearing number and rotor mass. The results of this study provide a better understanding of the nonlinear dynamics of aerodynamic grooved journal bearing systems

  9. Weak interaction matrix elements with staggered fermions

    International Nuclear Information System (INIS)

    Sharpe, S.R.

    1986-08-01

    An overview of the results of the Los Alamos Advanced Computing Group is given. The theory behind the measurement of Weak Interaction Matrix Elements using staggered fermions is presented, and contrasted with that for Wilson fermions. This is followed by a preliminary discussion of numerical results on a 12 3 x 30 lattice. 10 refs., 4 figs

  10. Kaon decay amplitudes using staggered fermions

    International Nuclear Information System (INIS)

    Sharpe, S.R.

    1986-12-01

    A status report is given of an attempt, using staggered fermions to calculate the real and imaginary parts of the amplitudes for K → ππ,. Semi-quantitative results are found for the imaginary parts, and these suggest that ε' might be smaller than previously expected in the standard model

  11. Fan Stagger Angle for Dirt Rejection

    Science.gov (United States)

    Gallagher, Edward J. (Inventor); Rose, Becky E. (Inventor); Brilliant, Lisa I. (Inventor)

    2015-01-01

    A gas turbine engine includes a spool, a turbine coupled to drive the spool, a propulsor coupled to be rotated about an axis by the turbine through the spool, and a gear assembly coupled between the propulsor and the spool such that rotation of the turbine drives the propulsor at a different speed than the spool. The propulsor includes a hub and a row of propulsor blades that extend from the hub. Each of the propulsor blades has a span between a root at the hub and a tip, and a chord between a leading edge and a trailing edge. The chord forms a stagger angle alpha with the axis, and the stagger angle alpha is less than 15 deg. at a position along the propulsor blade that is within an inboard 20% of the span.

  12. Staggered broad-band reflecting multilayers.

    Science.gov (United States)

    Heavens, O S; Liddell, H M

    1966-03-01

    Considerable broadening of the reflectance band of a multilayer stack may be obtained by staggering the layer thicknesses in such a way that they form either an arithmetic or geometric progression. Results are shown for asymmetric and symmetric filters of 15, 25, and 35 layers. The presence of the narrowband transmission peaks exhibited by the symmetric filters is explained, and the advantages of the use of this type of filter as an interference filter is discussed.

  13. Lower working heights decrease contraction intensity of shoulder muscles in a herringbone 30° milking parlor.

    Science.gov (United States)

    Cockburn, Marianne; Schick, Matthias; Maffiuletti, Nicola A; Gygax, Lorenz; Savary, Pascal; Umstätter, Christina

    2017-06-01

    Musculoskeletal disorders have been a main concern in milkers for many years. To improve posture, a formula was developed in a previous study to calculate ergonomically optimal working heights for various milking parlor types. However, the working height recommendations based on the formula for the herringbone 30° parlor were broad. To clarify the recommendations for the optimal working height, we investigated the effect of working height on upper limb and shoulder muscle contraction intensities. We evaluated 60 milking cluster attachment procedures in a herringbone 30° milking parlor in 7 men and 9 women. Specifically, we examined the effect of working height on muscle contraction intensity of 4 arm and shoulder muscles bilaterally (flexor carpi ulnaris, biceps brachii, deltoideus anterior, and upper trapezius) by using surface electromyography. The working heights (low, medium, and high), which reflect the ratio of the subject's height to the height of the udder base, were used in the milking health formula to determine and fit individual depth of pits. Data were evaluated for each muscle and arm side in the functions holding and attaching. Statistical analysis was performed using linear mixed effects models, where muscle contraction intensity served as a target variable, whereas working height coefficient, sex, subject height, and repetition were treated as fixed effects, and repetition group nested in working height nested in subject was considered a random effect. Contraction intensities decreased with decreasing working height for the deltoideus anterior and upper trapezius, but not for the flexor carpi ulnaris or the biceps brachii muscles in both holding and attaching arm functions. We found that milking at a lower working height reduced muscle contraction intensities of the shoulder muscles. Women showed higher contraction intensities than men, whereas subject height had no effect. The study demonstrated that a lower working height decreased muscular

  14. Perturbative improvement of staggered fermions using fat links

    International Nuclear Information System (INIS)

    Lee, Weonjong

    2002-01-01

    We study the possibility of improving staggered fermions using various fat links in order to reduce perturbative corrections to the gauge-invariant staggered fermion operators. We prove five theorems on SU(3) projection, triviality in renormalization, multiple SU(3) projections, uniqueness, and equivalence. As a result of these theorems, we show that, at the one-loop level, the renormalization of staggered fermion operators is identical between SU(3) projected Fat7 links and hypercubic links, as long as the action and operators are constructed by imposing the same perturbative improvement condition. In addition, we propose a new view of SU(3) projection as a tool of tadpole improvement for the staggered fermion doublers. As a conclusion, we present alternative choices of constructing fat links to improve the staggered fermion action and operators, which deserve further investigation

  15. Staggered Pairing Phenomenology for UBe_13

    Science.gov (United States)

    Martisovits, V.; Cox, D. L.

    1998-03-01

    The staggered-pairing Ginzburg-Landau phenomenology based upon Cooper pairs with a finite center-of-mass momentum was previously applied to the hexagonal heavy-fermion superconductors UPt_3,(R. Heid, Ya. B. Bazaliy, V. Martisovits, and D. L. Cox, Phys. Rev. Lett. 74), 2571 (1995). UPd_2Al_3, and UNi_2Al_3.(V. Martisovits and D. L. Cox (to be published); Report No. cond-mat/9706245.) Here we apply this phenomenology to study the cubic heavy-fermion superconductor UBe_13. We find the momentum of Cooper pairs to be at X points on the Brillouin-zone boundary and identify a three-component superconducting order parameter transforming as an X-point irreducible representation of the space group. Minimizing the free energy, we find possible superconducting phases and the upper critical field H_c2. We investigate coupling to strain fields and the possibility of magnetic order and charge-density waves induced by superconductivity. To explain multiple superconducting phases in the temperature-thorium-concentration phase diagram of U_1-xTh_xBe_13, we model the influence of thorium in terms of random tetragonal strain fields.

  16. Estimation of Parameters of CCF with Staggered Testing

    International Nuclear Information System (INIS)

    Kim, Myung-Ki; Hong, Sung-Yull

    2006-01-01

    Common cause failures are extremely important in reliability analysis and would be dominant to risk contributor in a high reliable system such as a nuclear power plant. Of particular concern is common cause failure (CCF) that degrades redundancy or diversity implemented to improve a reliability of systems. Most of analyses of parameters of CCF models such as beta factor model, alpha factor model, and MGL(Multiple Greek Letters) model deal a system with a nonstaggered testing strategy. Non-staggered testing is that all components are tested at the same time (or at least the same shift) and staggered testing is that if there is a failure in the first component, all the other components are tested immediately, and if it succeeds, no more is done until the next scheduled testing time. Both of them are applied in the nuclear power plants. The strategy, however, is not explicitly described in the technical specifications, but implicitly in the periodic test procedure. For example, some redundant components particularly important to safety are being tested with staggered testing strategy. Others are being performed with non-staggered testing strategy. This paper presents the parameter estimator of CCF model such as beta factor model, MGL model, and alpha factor model with staggered testing strategy. In addition, a new CCF model, rho factor model, is proposed and its parameter is presented with staggered testing strategy

  17. Heavy-light semileptonic decays in staggered chiral perturbation theory

    Science.gov (United States)

    Aubin, C.; Bernard, C.

    2007-07-01

    We calculate the form factors for the semileptonic decays of heavy-light pseudoscalar mesons in partially quenched staggered chiral perturbation theory (SχPT), working to leading order in 1/mQ, where mQ is the heavy-quark mass. We take the light meson in the final state to be a pseudoscalar corresponding to the exact chiral symmetry of staggered quarks. The treatment assumes the validity of the standard prescription for representing the staggered “fourth-root trick” within SχPT by insertions of factors of 1/4 for each sea-quark loop. Our calculation is based on an existing partially quenched continuum chiral perturbation theory calculation with degenerate sea quarks by Bećirević, Prelovsek, and Zupan, which we generalize to the staggered (and nondegenerate) case. As a byproduct, we obtain the continuum partially quenched results with nondegenerate sea quarks. We analyze the effects of nonleading chiral terms, and find a relation among the coefficients governing the analytic valence mass dependence at this order. Our results are useful in analyzing lattice computations of form factors B→π and D→K, when the light quarks are simulated with the staggered action.

  18. Direct numerical simulations of drag reduction in turbulent channel flow over bio-inspired herringbone riblet-texture

    NARCIS (Netherlands)

    Benschop, H.O.G.; Westerweel, J.; Breugem, W.P.

    2015-01-01

    The use of drag reducing surface textures is a promising passive method to reduce fuel consumption. Probably most wellknown is the utilisation of shark-skin inspired ridges or riblets parallel to the mean flow. They can reduce drag up to 10%. Recently another bio-inspired texture based on bird

  19. Reaction mechanisms and staggering in S+Ni collisions

    International Nuclear Information System (INIS)

    D'Agostino, M.; Bruno, M.; Gulminelli, F.; Morelli, L.; Baiocco, G.; Bardelli, L.; Barlini, S.; Cannata, F.; Casini, G.; Geraci, E.; Gramegna, F.; Kravchuk, V.L.; Marchi, T.; Moroni, A.; Ordine, A.; Raduta, Ad.R.

    2011-01-01

    The reactions 32 S+ 58 Ni and 32 S+ 64 Ni are studied at 14.5 A MeV. After a selection of the collision mechanism, we show that important even-odd effects are present in the isotopic fragment distributions when the excitation energy is small. Close to the multifragmentation threshold this staggering appears hidden by the rapid variation of the production yields with the fragment size. Once this effect is accounted for, the staggering appears to be a universal feature of fragment production, slightly enhanced when the emission source is neutron poor. A closer look at the behavior of the production yields as a function of the neutron excess N-Z, reveals that odd-even effects cannot be explained by pairing effects in the nuclear masses alone, but depend in a more complex way on the de-excitation chain.

  20. LES investigation of infinite staggered wind-turbine arrays

    International Nuclear Information System (INIS)

    Yang, Xiaolei; Sotiropoulos, Fotis

    2014-01-01

    The layouts of turbines affect the turbine wake interactions and thus the wind farm performance. The wake interactions in infinite staggered wind-turbine arrays are investigated and compared with infinite aligned turbine arrays in this paper. From the numerical results we identify three types of wake behaviours, which are significantly different from wakes in aligned wind-turbine arrays. For the first type, each turbine wake interferes with the pair of staggered downstream turbine wakes and the aligned downstream turbine. For the second type, each turbine wake interacts with the first two downstream turbine wakes but does not show significant interference with the second aligned downstream turbine. For the third type, each turbine wake recovers immediately after passing through the gap of the first two downstream turbines and has little interaction with the second downstream turbine wakes The extracted power density and power efficiency are also studied and compared with aligned wind-turbine arrays

  1. MILC staggered conjugate gradient performance on Intel KNL

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ruiz [Indiana Univ., Bloomington, IN (United States). Dept. of Physics; Detar, Carleton [Univ. of Utah, Salt Lake City, UT (United States). Dept. of Physics and Astronomy; Doerfler, Douglas W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Gottlieb, Steven [Indiana Univ., Bloomington, IN (United States). Dept. of Physics; Jha, Asish [Intel Corp., Hillsboro, OR (United States). Sofware and Services Group; Kalamkar, Dhiraj [Intel Labs., Bangalore (India). Parallel Computing Lab.; Toussaint, Doug [Univ. of Arizona, Tucson, AZ (United States). Physics Dept.

    2016-11-03

    We review our work done to optimize the staggered conjugate gradient (CG) algorithm in the MILC code for use with the Intel Knights Landing (KNL) architecture. KNL is the second gener- ation Intel Xeon Phi processor. It is capable of massive thread parallelism, data parallelism, and high on-board memory bandwidth and is being adopted in supercomputing centers for scientific research. The CG solver consumes the majority of time in production running, so we have spent most of our effort on it. We compare performance of an MPI+OpenMP baseline version of the MILC code with a version incorporating the QPhiX staggered CG solver, for both one-node and multi-node runs.

  2. An interpretation of staggering effects by correlation observables

    Directory of Open Access Journals (Sweden)

    Baiocco G.

    2012-07-01

    Full Text Available The reactions 32S+58,64Ni are studied at 14.5 A MeV. Evidence is found for odd-even effects in isotopic observables of the decay of a projectile-like source. The influence of secondary decays on the staggering is studied with a correlation function technique, showing that odd-even effects are due to interplay between pairing effects in the nuclear masses and in the level densities.

  3. An optimal staggered harvesting strategy for herbaceous biomass energy crops

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, M.G.; English, B.C. [Univ. of Tennessee, Knoxville, TN (United States)

    1993-12-31

    Biofuel research over the past two decades indicates lignocellulosic crops are a reliable source of feedstock for alternative energy. However, under the current technology of producing, harvesting and converting biomass crops, the cost of biofuel is not competitive with conventional biofuel. Cost of harvesting biomass feedstock is a single largest component of feedstock cost so there is a cost advantage in designing a biomass harvesting system. Traditional farmer-initiated harvesting operation causes over investment. This study develops a least-cost, time-distributed (staggered) harvesting system for example switch grass, that calls for an effective coordination between farmers, processing plant and a single third-party custom harvester. A linear programming model explicitly accounts for the trade-off between yield loss and benefit of reduced machinery overhead cost, associated with the staggered harvesting system. Total cost of producing and harvesting switch grass will decline by 17.94 percent from conventional non-staggered to proposed staggered harvesting strategy. Harvesting machinery cost alone experiences a significant reduction of 39.68 percent from moving from former to latter. The net return to farmers is estimated to increase by 160.40 percent. Per tonne and per hectare costs of feedstock production will decline by 17.94 percent and 24.78 percent, respectively. These results clearly lend support to the view that the traditional system of single period harvesting calls for over investment on agricultural machinery which escalates the feedstock cost. This social loss to the society in the form of escalated harvesting cost can be avoided if there is a proper coordination among farmers, processing plant and custom harvesters as to when and how biomass crop needs to be planted and harvested. Such an institutional arrangement benefits producers, processing plant and, in turn, end users of biofuels.

  4. Optimization of the Single Staggered Wire and Tube Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Arsana I Made

    2016-01-01

    Full Text Available Wire and tube heat exchanger consists of a coiled tube, and wire is welded on the two sides of it in normal direction of the tube. Generally,wire and tube heat exchanger uses inline wire arrangement between the two sides, whereas in this study, it used staggered wire arrangement that reduces the restriction of convection heat transfer. This study performed the optimization of single staggered wire and tube heat exchanger to increase the capacity and reduce the mass of the heat exchanger. Optimization was conducted with the Hooke-Jeeves method, which aims to optimize the geometry of the heat exchanger, especially on the diameter (dw and the distance between wires (pw. The model developed to present heat transfer correlations on single staggered wire and tube heat exchanger was valid. The maximum optimization factor obtained when the diameter wire was 0.9 mm and the distance between wires (pw was 11 mm with the fref value = 1.5837. It means that the optimized design only using mass of 59,10 % and could transfer heat about 98,5 % from the basis design.

  5. Towards an understanding of staggering effects in dissipative binary collisions

    International Nuclear Information System (INIS)

    D'Agostino, M.; Bruno, M.; Gulminelli, F.; Morelli, L.; Baiocco, G.; Bardelli, L.; Barlini, S.; Cannata, F.; Casini, G.; Geraci, E.; Gramegna, F.; Kravchuk, V.L.; Marchi, T.; Moroni, A.; Ordine, A.; Raduta, Ad.R.

    2012-01-01

    The reactions 32 S+ 58,64 Ni are studied at 14.5 A MeV. Evidence is found for important odd–even effects in isotopic observables of selected peripheral collisions corresponding to the decay of a projectile-like source. The influence of secondary decays on the staggering is studied with a correlation function technique. It is shown that this method is a powerful tool to get experimental information on the evaporation chain, in order to constrain model calculations. Specifically, we show that odd–even effects are due to interplay between pairing effects in the nuclear masses and in the level densities.

  6. Improving the quark number susceptibilities for staggered fermions

    International Nuclear Information System (INIS)

    Gavai, Rajiv V.

    2003-01-01

    Quark number susceptibilities approach their ideal gas limit at sufficiently high temperatures. As in the case of other thermodynamic quantities, this limit itself is altered substantially on lattices with small temporal extent, N t = 4-8, making it thus difficult to check the validity of perturbation theory. Unlike other observables, improving susceptibilities or number densities is subject to constraints of current conservation and absence of chemical potential (μ) dependent divergences. We construct such an improved number density and susceptibility for staggered fermions and show that they approximate the continuum ideal gas limit better on small temporal lattices

  7. XFEM Modelling of Multi-holes Plate with Single-row and Staggered Holes Configurations

    Directory of Open Access Journals (Sweden)

    Supar Khairi

    2017-01-01

    Full Text Available Joint efficiency is the key to composite structures assembly design, good structures response is dependent upon multi-holes behavior as subjected to remote loading. Current benchmarking work were following experimental testing series taken from literature on multi-holes problem. Eleven multi-hole configurations were investigated with various pitch and gage distance of staggered holes and non-staggered holes (single-row holes. Various failure modes were exhibited, most staggered holes demonstrates staggered crack path but non-staggered holes series displayed crack path along net-section plane. Stress distribution were carried out and good agreement were exhibited in experimental observation as reported in the respective literature. Consequently, strength prediction work were carried out under quasi-static loading, most showed discrepancy between 8% -31%, better prediction were exhibited in thicker and non-staggered holes plate combinations.

  8. Global phenomenological descriptions of nuclear odd-even mass staggering

    DEFF Research Database (Denmark)

    Hove, Dennis; Jensen, Aksel Stenholm; Riisager, Karsten

    2013-01-01

    We examine the general nature of nuclear odd-even mass differences by employing neutron and proton mass relations that emphasize these effects. The most recent mass tables are used. The possibility of a neutron excess dependence of the staggering is examined in detail in separate regions defined ...... into a global phenomenological expression, ready to use in a binding energy formula. The results deviate from previous parametrizations, and in particular found to be significantly superior to a recent two term, A−1 dependence.......We examine the general nature of nuclear odd-even mass differences by employing neutron and proton mass relations that emphasize these effects. The most recent mass tables are used. The possibility of a neutron excess dependence of the staggering is examined in detail in separate regions defined...... by the main nuclear shells, and a clear change in this dependency is found at Z=50 for both neutrons and protons. A further separation into odd and even neutron (proton) number produces very accurate local descriptions of the mass differences for each type of nucleons. These odd-even effects are combined...

  9. ΔI = 2 Nuclear Staggering in Superdeformed Rotational Bands

    Directory of Open Access Journals (Sweden)

    Okasha M. D.

    2014-01-01

    Full Text Available A four parameters model including collective rotational en ergies to fourth order is ap- plied to reproduce the ∆ I = 2 staggering in transition energies in four selected super deformed rotational bands, namely, 148 Gd (SD6, 194 Hg (SD1, SD2, SD3. The model parameters and the spin of the bandhead have been extracted a ssuming various val- ues to the lowest spin of the bandhead at nearest integer, in o rder to obtain a minimum root mean square deviation between calculated and the exper imental transition energies. This allows us to suggest the spin values for the energy level s which are experimentally unknown. For each band a staggering parameter represent the deviation of the transition energies from a smooth reference has been determined by calc ulating the fourth order derivative of the transition energies at a given spin. The st aggering parameter contains five consecutive transition energies which is denoted here a s the five-point formula. In order to get information about the dynamical moment of ine rtia, the two point for- mula which contains only two consecutive transition energi es has been also considered. The dynamical moment of inertia decreasing with increasing rotational frequency for A ∼ 150, while increasing for A ∼ 190 mass regions.

  10. Staggered and short-period solutions of the saturable discrete nonlinear Schrodinger equation

    DEFF Research Database (Denmark)

    Khare, A.; Rasmussen, K.O.; Samuelsen, Mogens Rugholm

    2009-01-01

    We point out that the nonlinear Schrodinger lattice with a saturable nonlinearity also admits staggered periodic aswell as localized pulse-like solutions. Further, the same model also admits solutions with a short period. We examine the stability of these solutions and find that the staggered...

  11. Lowrank seismic-wave extrapolation on a staggered grid

    KAUST Repository

    Fang, Gang

    2014-05-01

    © 2014 Society of Exploration Geophysicists. We evaluated a new spectral method and a new finite-difference (FD) method for seismic-wave extrapolation in time. Using staggered temporal and spatial grids, we derived a wave-extrapolation operator using a lowrank decomposition for a first-order system of wave equations and designed the corresponding FD scheme. The proposed methods extend previously proposed lowrank and lowrank FD wave extrapolation methods from the cases of constant density to those of variable density. Dispersion analysis demonstrated that the proposed methods have high accuracy for a wide wavenumber range and significantly reduce the numerical dispersion. The method of manufactured solutions coupled with mesh refinement was used to verify each method and to compare numerical errors. Tests on 2D synthetic examples demonstrated that the proposed method is highly accurate and stable. The proposed methods can be used for seismic modeling or reverse-time migration.

  12. Temperature-dependent thermal properties of a paraffin phase change material embedded with herringbone style graphite nanofibers

    International Nuclear Information System (INIS)

    Warzoha, Ronald J.; Weigand, Rebecca M.; Fleischer, Amy S.

    2015-01-01

    Highlights: • The thermal properties of a PCM with nanofibers are determined. • The solid-phase thermal conductivity scales exponentially with volume fraction. • The liquid-phase thermal conductivity is only enhanced beyond a critical percolation threshold. • The nanoscale interface resistance depends on the nanoparticle’s dimensionality. • The thermal diffusivity and volumetric heat capacity of the nanoenhanced PCMs are found. - Abstract: In many studies, carbon nanoparticles with high values of thermal conductivity (10–3000 W/m K) have been embedded into phase change thermal energy storage materials (PCMs) in order to enhance their bulk thermal properties. While a great deal of work to date has focused on determining the effect of these nanoparticles on a PCM’s solid phase thermal properties, little is known about their effect on its liquid phase thermal properties. Thus, in this study, the effect of implanting randomly oriented herringbone style graphite nanofibers (HGNF, average diameter = 100 nm, average length = 20 μm) on the bulk thermal properties of an organic paraffin PCM (IGI 1230A, T melt = 329.15 K) in both the solid and liquid phase is quantified. The bulk thermal conductivity, volumetric heat capacity and thermal diffusivity of HGNF/PCM nanocomposites are obtained as a function of temperature and HGNF volume loading level. It is found that the property enhancement varies significantly depending on the material phase. In order to explain the difference between solid and liquid phase thermal properties, heat flow at the nanoparticle–PCM and nanoparticle–nanoparticle interfaces is examined as a function of HGNF loading level and temperature. To do this, the solid and liquid phase thermal boundary resistances (TBRs) between the nanoparticles and the surrounding PCM and/or between contacting nanoparticles are found. Results suggest that the TBR at the HGNF–PCM interface is nearly double the TBR across the HGNF–HGNF interface in

  13. The interference between two flat plates normal to a stream in staggered arrangement, 1

    International Nuclear Information System (INIS)

    Hirano, Kimitaka; Kawashima, Akira; Ohsako, Hideyuki.

    1983-01-01

    The clarification of the mutual interference characteristics between the bodies with sharp corners, such as flat plates and rectangular prisms placed perpendicularly to flow, is a fundamental and important problem. But it has not yet been sufficiently clarified. In flat plates, the points of breaking away do not move, a large breaking away region is in the wake, and the thickness is very thin in the direction of main flow. Moreover, a moment arises around the center of flat plates. In this study, a new parameter expressing the influence of channel walls on a single flat plate in the measuring part of two-dimensional wind tunnel experiment was proposed. The change of steady drag coefficient and Strouhal number corresponding to the series and parallel arrangements of two plates was clarified, and the patterns of the mutual interference were classified by using the results of visualizing flow in a circulation tank together. By the experimental results in the widely changed staggered arrangements, the isodrag contour diagram and isomoment contour diagram were drawn, and the general characteristics of mutual interference related to steady drag and moment were clarified. The experimental setup and method and the results are reported. (Kako, I.)

  14. Ginsparg-Wilson pions scattering in a sea of staggered quarks

    International Nuclear Information System (INIS)

    Chen, J.-W.; O'Connell, Donal; Van de Water, Ruth; Walker-Loud, Andre

    2006-01-01

    We calculate isospin 2 pion-pion scattering in chiral perturbation theory for a partially quenched, mixed action theory with Ginsparg-Wilson valence quarks and staggered sea quarks. We point out that for some scattering channels, the power-law volume dependence of two-pion states in nonunitary theories such as partially quenched or mixed action QCD is identical to that of QCD. Thus one can extract infinite-volume scattering parameters from mixed action simulations. We then determine the scattering length for both 2 and 2+1 sea quarks in the isospin limit. The scattering length, when expressed in terms of the pion mass and the decay constant measured on the lattice, has no contributions from mixed valence-sea mesons, thus it does not depend upon the parameter, C Mix , that appears in the chiral Lagrangian of the mixed theory. In addition, the contributions which nominally arise from operators appearing in the mixed action O(a 2 m q ) Lagrangian exactly cancel when the scattering length is written in this form. This is in contrast to the scattering length expressed in terms of the bare parameters of the chiral Lagrangian, which explicitly exhibits all the sicknesses and lattice spacing dependence allowed by a partially quenched mixed action theory. These results hold for both 2 and 2+1 flavors of sea quarks

  15. Animal physiology and genetic aspects of ryegrass staggers in grazing sheep.

    Science.gov (United States)

    Morris, C A; Wheeler, T T; Henderson, H V; Towers, N R; Phua, S H

    2017-07-01

    Ryegrass staggers (RGS) is a metabolic disease of herbivores, caused by the ingestion of perennial ryegrass (Lolium perenne L.) containing a fungal endophyte (Neotyphodium lolii) which produces a tremorgenic toxin, lolitrem B. RGS has a major economic impact for agriculture in New Zealand as well as internationally. Management of RGS in grazing sheep can be problematic, and there is an incomplete knowledge of the interaction between the toxin and the grazing animal. This review is focused on recent advances in understanding the molecular physiology of RGS in the affected animal as well as the influence of animal genetics on the degree of susceptibility to RGS. Investigations to date suggest that the primary target for toxin is the large conductance, calcium-activated, potassium (BK) channel, resulting in disruption of neuromuscular junction signalling. Genetic investigation has established the existence of genes influencing resistance to RGS, however their identity has not been confirmed and their impact has not been established. Studies to date suggest that a multi-gene selection approach will be necessary in order to develop an effective selection tool for use in the agricultural industries.

  16. Spontaneous emission spectra from a staggered-array undulator

    International Nuclear Information System (INIS)

    Shimada, Shigeki; Okada, Kouji; Masuda, Kai; Sobajima, Masaaki; Yoshikawa, Kiyoshi; Ohnishi, Masami; Yamamoto, Yasushi; Toku, Hisayuki

    1997-01-01

    A staggered-array undulator set inside the superconducting solenoid coils is shown to be able to provide high undulator fields larger than the longitudinal magnetic fields, a small undulator period, easy tunability through the solenoid coil current, and compact and easy fabrication. The overall performance characteristics of this undulator were studied mainly with respect to iron and aluminum disk widths, and spontaneous emission spectra through the numerical calculations. The maximum undulator field is found to be obtained for the ratio of the aluminum disk width to the undulator period of 0.45. The line widths (FWHM) of the spontaneous emission spectra, however, do not show N w -1 dependence on the number of the undulator period N w for practical beams with a Gaussian distribution, compared with for a single electron. The energy spread among various parameters is seen to play an important role in reducing the FWHM with increase of N w . The large tunability of the wavelength is proved to cover 6-10 mm by changing the solenoid magnetic field from 0.4 T to 1.6 T. (author)

  17. X-ray imaging bilinear staggered GaAs detectors

    Energy Technology Data Exchange (ETDEWEB)

    Achmadullin, R.A.; Dvoryankin, V.F. E-mail: vfd217@ire216.msk.su; Dvoryankina, G.G.; Dikaev, Y.M.Yu.M.; Krikunov, A.I.; Kudryashov, A.A.; Panova, T.M.; Petrov, A.G.; Telegin, A.A

    2004-09-21

    The multichannel bilinear X-ray detector based on epitaxial GaAs structures is developed to obtain a digital X-ray image. Each detector operates in photovoltaic mode without reverse bias that enables almost complete elimination of detector noise arising due to leakage currents. The sensitivity range of the epitaxial GaAs photovoltaic X-ray detector covers the effective energies from 8 to 120 keV. A maximum response of the detector operating in the short-circuit mode was observed at an energy of 35 keV and amounted to 30 {mu}A min/(Gy cm{sup 2}). The multichannel detector was made of 1024 pixels with pitch of 0.8 mm. The spatial resolution of double staggered sensor row is twice as high as the resolution of that of single sensor row with the same pitch. Measured spatial resolution is 1.2 line-pairs/mm, contrast sensitivity not worse 1% and dynamic range defined as the ratio of maximum detectable X-ray signal to electronic noise level more than 2000 are received.

  18. X-ray imaging bilinear staggered GaAs detectors

    International Nuclear Information System (INIS)

    Achmadullin, R.A.; Dvoryankin, V.F.; Dvoryankina, G.G.; Dikaev, Y.M.Yu.M.; Krikunov, A.I.; Kudryashov, A.A.; Panova, T.M.; Petrov, A.G.; Telegin, A.A.

    2004-01-01

    The multichannel bilinear X-ray detector based on epitaxial GaAs structures is developed to obtain a digital X-ray image. Each detector operates in photovoltaic mode without reverse bias that enables almost complete elimination of detector noise arising due to leakage currents. The sensitivity range of the epitaxial GaAs photovoltaic X-ray detector covers the effective energies from 8 to 120 keV. A maximum response of the detector operating in the short-circuit mode was observed at an energy of 35 keV and amounted to 30 μA min/(Gy cm 2 ). The multichannel detector was made of 1024 pixels with pitch of 0.8 mm. The spatial resolution of double staggered sensor row is twice as high as the resolution of that of single sensor row with the same pitch. Measured spatial resolution is 1.2 line-pairs/mm, contrast sensitivity not worse 1% and dynamic range defined as the ratio of maximum detectable X-ray signal to electronic noise level more than 2000 are received

  19. High temperature QCD with three flavors of improved staggered quarks

    International Nuclear Information System (INIS)

    Bernard, C.; Burch, T.; Tar, C.E. de; Gottlieb, Steven; Gregory, Eric; Heller, U.M.; Osborn, J.; Sugar, R.L.; Toussaint, D.

    2003-01-01

    We present an update of our study of high temperature QCD with three flavors of quarks, using a Symanzik improved gauge action and the Asqtad staggered quark action. Simulations are being carried out on lattices with N t = 4, 6 and 8 for the case of three degenerate quarks with masses less than or equal to the strange quark mass, m s and on lattices with N t = 6 and 8 for degenerate up and down quarks with masses in the range 0.2m s ≤ m u,d ≤ 0.6m s and the strange quark fixed near its physical value. We also report on first computations of quark number susceptibilities with the Asqtad action. These susceptibilities are of interest because they can be related to event-by-event fluctuations in heavy ion collision experiments. Use of the improved quark action leads to a substantial reduction in lattice artifacts. This can be seen already for free fermions and carries over into our results for QCD

  20. Systematics of the K suppi = 2+ gamma vibrational bands and odd-even staggering

    CERN Document Server

    Gupta, J B

    2003-01-01

    The structure of the K suppi = 2+ gamma vibrational bands and the quasi-gamma bands of even-Z-even-N nuclei is investigated on a global scale, vis-a-vis the variation of band head, the moment of inertia of the band and the odd-even spin staggering. The variation with N and Z and with spin J of the odd-even spin energy staggering index is studied and a unified view of the same is presented. (author)

  1. Two-color lattice QCD with staggered quarks

    Energy Technology Data Exchange (ETDEWEB)

    Scheffler, David

    2015-07-20

    The study of quantum chromodynamics (QCD) at finite temperature and density provides important contributions to the understanding of strong-interaction matter as it is present e.g. in nuclear matter and in neutron stars or as produced in heavy-ion collision experiments. Lattice QCD is a non-perturbative approach, where equations of motion for quarks and gluons are discretized on a finite space-time lattice. The method successfully describes the behavior of QCD in the vacuum and at finite temperature, however it cannot be applied to finite baryon density due to the fermion sign problem. Various QCD-like theories, that offer to draw conclusions about QCD, allow simulations also at finite densities. In this work we investigate two-color QCD as a popular example of a QCD-like theory free from the sign problem with methods from lattice gauge theory. For the generation of gauge configurations with two dynamical quark flavors in the staggered formalism with the ''rooting trick'' we apply the Rational Hybrid Monte Carlo (RHMC) algorithm. We carry out essential preparatory work for future simulations at finite density. As a start, we concentrate on the calculation of the effective potential for the Polyakov loop, which is an order parameter for the confinement-deconfinement transition, in dependence of the temperature and quark mass. It serves as an important input for effective models of QCD. We obtain the effective potential via the histogram method from local distributions of the Polyakov loop. To study the influence of dynamical quarks on gluonic observables, the simulations are performed with large quark masses and are compared to calculations in the pure gauge theory. In the second part of the thesis we examine aspects of the chiral phase transition along the temperature axis. The symmetry group of chiral symmetry in two-color QCD is enlarged to SU(2N{sub f}). Discretized two-color QCD in the staggered formalism exhibits a chiral symmetry breaking

  2. The Nucleon Axial Form Factor and Staggered Lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Aaron Scott [Chicago U.

    2017-01-01

    The study of neutrino oscillation physics is a major research goal of the worldwide particle physics program over the upcoming decade. Many new experiments are being built to study the properties of neutrinos and to answer questions about the phenomenon of neutrino oscillation. These experiments need precise theoretical cross sections in order to access fundamental neutrino properties. Neutrino oscillation experiments often use large atomic nuclei as scattering targets, which are challenging for theorists to model. Nuclear models rely on free-nucleon amplitudes as inputs. These amplitudes are constrained by scattering experiments with large nuclear targets that rely on the very same nuclear models. The work in this dissertation is the rst step of a new initiative to isolate and compute elementary amplitudes with theoretical calculations to support the neutrino oscillation experimental program. Here, the eort focuses on computing the axial form factor, which is the largest contributor of systematic error in the primary signal measurement process for neutrino oscillation studies, quasielastic scattering. Two approaches are taken. First, neutrino scattering data on a deuterium target are reanalyzed with a model-independent parametrization of the axial form factor to quantify the present uncertainty in the free-nucleon amplitudes. The uncertainties on the free-nucleon cross section are found to be underestimated by about an order of magnitude compared to the ubiquitous dipole model parametrization. The second approach uses lattice QCD to perform a rst-principles computation of the nucleon axial form factor. The Highly Improved Staggered Quark (HISQ) action is employed for both valence and sea quarks. The results presented in this dissertation are computed at physical pion mass for one lattice spacing. This work presents a computation of the axial form factor at zero momentum transfer, and forms the basis for a computation of the axial form factor momentum dependence

  3. Numerical properties of staggered quarks with a taste-dependent mass term

    CERN Document Server

    de Forcrand, Philippe; Panero, Marco

    2012-01-01

    The numerical properties of staggered Dirac operators with a taste-dependent mass term proposed by Adams [1,2] and by Hoelbling [3] are compared with those of ordinary staggered and Wilson Dirac operators. In the free limit and on (quenched) interacting configurations, we consider their topological properties, their spectrum, and the resulting pion mass. Although we also consider the spectral structure, topological properties, locality, and computational cost of an overlap operator with a staggered kernel, we call attention to the possibility of using the Adams and Hoelbling operators without the overlap construction. In particular, the Hoelbling operator could be used to simulate two degenerate flavors without additive mass renormalization, and thus without fine-tuning in the chiral limit.

  4. Gap states and edge properties of rectangular graphene quantum dot in staggered potential

    Science.gov (United States)

    Jeong, Y. H.; Eric Yang, S.-R.

    2017-09-01

    We investigate edge properties of a gapful rectangular graphene quantum dot in a staggered potential. In such a system gap states with discrete and closely spaced energy levels exist that are spatially located on the left or right zigzag edge. We find that, although the bulk states outside the energy gap are nearly unaffected, spin degeneracy of each gap state is lifted by the staggered potential. We have computed the occupation numbers of spin-up and -down gap states at various values of the strength of the staggered potential. The electronic and magnetic properties of the zigzag edges depend sensitively on these numbers. We discuss the possibility of applying this system as a single electron spintronic device.

  5. Single-molecule observation of helix staggering, sliding, and coiled coil misfolding

    Science.gov (United States)

    Xi, Zhiqun; Gao, Ying; Sirinakis, George; Guo, Honglian; Zhang, Yongli

    2012-01-01

    The biological functions of coiled coils generally depend on efficient folding and perfect pairing of their α-helices. Dynamic changes in the helical registry that lead to staggered helices have only been proposed for a few special systems and not found in generic coiled coils. Here, we report our observations of multiple staggered helical structures of two canonical coiled coils. The partially folded structures are formed predominantly by coiled coil misfolding and occasionally by helix sliding. Using high-resolution optical tweezers, we characterized their energies and transition kinetics at a single-molecule level. The staggered states occur less than 2% of the time and about 0.1% of the time at zero force. We conclude that dynamic changes in helical registry may be a general property of coiled coils. Our findings should have broad and unique implications in functions and dysfunctions of proteins containing coiled coils. PMID:22451899

  6. Ergovaline does not alter the severity of ryegrass staggers induced by lolitrem B.

    Science.gov (United States)

    Finch, S C; Vlaming, J B; Sutherland, B L; van Koten, C; Mace, W J; Fletcher, L R

    2018-03-01

    To investigate a possible interaction between lolitrem B and ergovaline by comparing the incidence and severity of ryegrass staggers in sheep grazing ryegrass (Lolium perenne) containing lolitrem B or ryegrass containing both lolitrem B and ergovaline. Ninety lambs, aged approximately 6 months, were grazed on plots of perennial ryegrass infected with either AR98 endophyte (containing lolitrem B), standard endophyte (containing lolitrem B and ergovaline) or no endophyte, for up to 42 days from 2 February 2010. Ten lambs were grazed on three replicate plots per cultivar. Herbage samples were collected for alkaloid analysis and lambs were scored for ryegrass staggers (scores from 0-5) weekly during the study. Any animal which was scored ≥4 was removed from the study. Concentrations of lolitrem B did not differ between AR98 and standard endophyte-infected pastures during the study period (p=0.26), and ergovaline was present only in standard endophyte pastures. Ryegrass staggers was observed in sheep grazing both the AR98 and standard endophyte plots, with median scores increasing in the third week of the study. Prior to the end of the 42-day grazing period, 22 and 17 animals were removed from the standard endophyte and AR98 plots, respectively, because their staggers scores were ≥4. The cumulative probability of lambs having scores ≥4 did not differ between animals grazing the two pasture types (p=0.41). There was no evidence for ergovaline increasing the severity of ryegrass staggers induced by lolitrem B. In situations where the severity of ryegrass staggers appears to be greater than that predicted on the basis of concentrations of lolitrem B, the presence of other tremorgenic alkaloids should be investigated.

  7. Horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications.

    Science.gov (United States)

    Ma, Hongcai; Wu, Lin

    2015-07-10

    We present the design of a horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications. This solar concentrator consists of an array of telecentric primary concentrators, a horizontally staggered lightguide layer, and a vertically tapered lightguide layer. The primary concentrator is realized by two plano-aspheric lenses with lateral movement and maintains a high F-number over an angle range of ±23.5°. The results of the simulations show that the solar concentrator achieves a high concentration ratio of 500× with ±0.5° of acceptance angle by a single-axis tracker and dual lateral translation stages.

  8. Cu-PDC-bpa solid coordination frameworks (PDC=2,5-pyrindinedicarboxylate; bpa=1,2-DI(4-pyridil)ethane)): 2D and 3D structural flexibility producing a 3-c herringbone array next to ideal

    Energy Technology Data Exchange (ETDEWEB)

    Llano-Tomé, Francisco, E-mail: francisco.llano@ehu.eus [Departamento de Mineralogía y Petrología, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU), Apdo 644, 48080 Bilbao (Spain); Bazán, Begoña, E-mail: bego.bazan@ehu.eus [Departamento de Mineralogía y Petrología, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU), Apdo 644, 48080 Bilbao (Spain); BCMaterials Parque Tecnológico de Zamudio, Ibaizabal Bidea, Edificio 500–Planta 1, 48160 Derio (Spain); Urtiaga, Miren-Karmele, E-mail: karmele.urtiaga@ehu.eus [Departamento de Mineralogía y Petrología, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU), Apdo 644, 48080 Bilbao (Spain); Barandika, Gotzone, E-mail: gotzone.barandika@ehu.eus [Departamento de Química Inorgánica, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV/EHU), Apdo 644, 48080 Bilbao (Spain); Antonia Señarís-Rodríguez, M., E-mail: tonasr@udc.es [QUIMOLMAT, Centro de Investigaciones Científicas Avanzadas (CICA) and Departamento de Química Fundamental, Facultad de Ciencias, Universidad de A Coruña, 15071A Coruña (Spain); and others

    2015-10-15

    Combination of polycarboxylate anions and dipyridyl ligands is an effective strategy to produce solid coordination frameworks (SCF) which are crystalline materials based on connections between metal ions through organic ligands. In this context, this work is focused on two novel Cu{sup II}-based SCFs exhibiting PDC (2,5-pyridinedicarboxylate) and bpa (1,2-di(4-pyridyl)ethane), being the first structures reported in literature containing both ligands. Chemical formula are [Cu{sub 2}[(PDC){sub 2}(bpa)(H{sub 2}O){sub 2}]·3H{sub 2}O·DMF (1), and [Cu{sub 2}(PDC){sub 2}(bpa)(H{sub 2}O){sub 2}]·7H{sub 2}O (2), where DMF is dimethylformamide. Compounds 1 and 2 have been characterized by means of X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric (TG) analysis, differential thermal analysis (DTA) and dielectric measurements. The crystallographic analysis revealed that compounds 1 and 2 can be described as herringbone-type layers formed by helicoidal Cu-PDC-Cu chains connected through bpa ligands. Solvent molecules are crystallized between the layers, providing the inter-layer connections through hydrogen bonds. Differences between both compounds are attributable to the flexibility of bpa (in 2D) as well as to the 3D packing of the layers which is solvent dependent. This fact results in the fact that compound 2 is the most regular 3-c herringbone array reported so far. The structural dynamism of these networks is responsible for the crystalline to-amorphous to-crystalline (CAC) transformation from compound 1 to compound 2. Crystallochemical features for both compounds have also been studied and compared to similar 3-connected herringbone-arrays. - Graphical abstract: Cu-PDC-bpa 3-c herringbone arrays. - Highlights: • The most ideal herringbone array reported so far is a Cu-PDC-bpa SCF. • Conformational freedom of bpa results in 2D and 3D flexibility of the SCFs. • The flexibility of the SCFs is related to a phase transformation. • Dielectric

  9. A superlinearly convergent finite volume method for the incompressible Navier-Stokes equations on staggered unstructured grids

    International Nuclear Information System (INIS)

    Vidovic, D.; Segal, A.; Wesseling, P.

    2004-01-01

    A method for linear reconstruction of staggered vector fields with special treatment of the divergence is presented. An upwind-biased finite volume scheme for solving the unsteady incompressible Navier-Stokes equations on staggered unstructured triangular grids that uses this reconstruction is described. The scheme is applied to three benchmark problems and is found to be superlinearly convergent in space

  10. Weakly coupled S=1/2 quantum Heisenberg antiferromagnetic chains in an effective staggered field

    International Nuclear Information System (INIS)

    Sato, Masahiro; Oshikawa, Masaki

    2002-01-01

    We study weakly coupled S=1/2 quantum Heisenberg antiferromagnetic chains in an effective staggered field. Applying mean-field (MF) theory, spin-wave theory and chain MF (CMF) theory, we can see analytically some effects of the staggered field in this higher dimensional spin system. In particular, when the staggered field and the inter-chain inter-action compete with each other, we conjecture from the MF theory that a nontrivial phase is present. The spin wave theory predicts that the behavior of the gaps induced by a staggered field is different between the competitive case and the non-competitive case. When the inter-chain interactions are weak enough, we can improve the MF phase diagram by using CMF theory and the analytical results of field theories. The ordered phase region predicted by the CMF theory is fairly smaller than one of the MF theory. Cu-benzoate, CuCl 2 · 2DMSO (dimethylsulphoxide), BaCu 2 (Si 1-x Ge x ) 2 O 7 , etc., could be described by our model in enough low temperature. (author)

  11. Kinetics of full scrum and staggered scrum engagement in under 19 ...

    African Journals Online (AJOL)

    Two hundred and eight male Rugby Union players from 13 high schools, whose ages ranged from 16 to 19 years, were used to examine the kinetics of the full scrum versus staggered scrum engagement techniques. Telemetric pressure transducers were used to measure the engagement and sustained forces acting on the ...

  12. Enhancement of Radiative Efficiency with Staggered InGaN Quantum Well Light Emitting Diodes

    Energy Technology Data Exchange (ETDEWEB)

    Tansu, Nelson; Dierolf, Volkmar; Huang, Gensheng; Penn, Samson; Zhao, Hongping; Liu, Guangyu; Li, Xiaohang; Poplawsky, Jonathan

    2011-07-14

    The technology on the large overlap InGaN QWs developed in this program is currently implemented in commercial technology in enhancing the internal quantum efficiency in major LED industry in US and Asia. The scientific finding from this work supported by the DOE enabled the implementation of this step-like staggered quantum well in the commercial LEDs.

  13. The use of staggered scheme and an absorbing buffer zone for computational aeroacoustics

    Science.gov (United States)

    Nark, Douglas M.

    1995-01-01

    Various problems from those proposed for the Computational Aeroacoustics (CAA) workshop were studied using second and fourth order staggered spatial discretizations in conjunction with fourth order Runge-Kutta time integration. In addition, an absorbing buffer zone was used at the outflow boundaries. Promising results were obtained and provide a basis for application of these techniques to a wider variety of problems.

  14. Experimental study of induced staggered magnetic fields in dysprosium gallium garnet (DGG)

    International Nuclear Information System (INIS)

    Steiner, M.; Corliss, L.M.; Hastings, J.M.; Blume, M.; Giordano, N.; Wolf, W.P.

    1979-01-01

    Neutron diffraction techniques have been used to study induced staggered magnetic field effects in DGG. The application of a uniform magnetic field at temperatures much greater than the Neel temperature induces a significant amount of antiferromagnetic order. The temperature and field dependences of this effect are in good agreement with recent theoretical predicions

  15. Partial dynamical symmetry and odd-even staggering in deformed nuclei

    Directory of Open Access Journals (Sweden)

    Leviatan A.

    2015-01-01

    Full Text Available Partial dynamical symmetry (PDS is shown to be relevant for describing the odd-even staggering in the γ-band of 156Gd while retaining solvability and good SU(3 symmetry for the ground and β bands. Several classes of interacting boson model Hamiltonians with SU(3 PDS are surveyed.

  16. Remarks on the determination of the odd--even staggering parameter in the spectrum of cadmium

    International Nuclear Information System (INIS)

    Gerstenkorn, S.; Stroke, H.H.

    1976-01-01

    From an analysis of the isotope shifts in the Cd 3261, 4678, and 4416 A lines, it is pointed out that a precise determination of the odd--even staggering parameter is limited less by experimental error than by the lack of reliable knowledge of the specific mass effect

  17. A study of manufacturing tubes with nano/ultrafine grain structure by stagger spinning

    International Nuclear Information System (INIS)

    Xia, Qinxiang; Xiao, Gangfeng; Long, Hui; Cheng, Xiuquan; Yang, Baojian

    2014-01-01

    Highlights: • Proposing a method of manufacturing tubes with nano/ultrafine crystal. • Obtaining the refined ferritic grains with an size of 500 nm after stagger spinning. • Obtaining the equiaxial ferritic grains with an size of 600 nm after annealing. - Abstract: A new method of manufacturing tubes with nano/ultrafine grain structure by stagger spinning and recrystallization annealing is proposed in this study. Two methods of the stagger spinning process are developed, the corresponding macroforming quality, microstructural evolution and mechanical properties of the spun tubes made of ASTM 1020 steel are analysed. The results reveal that a good surface smoothness and an improved spin-formability of spun parts can be obtained by the process combining of 3-pass spinning followed by a 580 °C × 0.5 h static recrystallization and 2-pass spinning with a 580 °C × 1 h static recrystallization annealing under the severe thinning ratio of wall thickness reduction. The ferritic grains with an average initial size of 50 μm are refined to 500 nm after stagger spinning under the 87% thinning ratio of wall thickness reduction. The equiaxial ferritic grains with an average size of 600 nm are generated through re-nucleation and grain growth by subsequent recrystallization annealing at 580 °C for 1 h heat preservation. The tensile strength of spun tubes has been founded to be proportional to the reciprocal of layer spacing of pearlite (LSP), and the elongation is inversely proportional to the reciprocal of LSP. This study shows that the developed method of stagger power spinning has the potential to be used to manufacture bulk metal components with nano/ultrafine grain structure

  18. A representation of curved boundaries for the solution of the Navier-Stokes equations on a staggered three-dimensional Cartesian grid

    International Nuclear Information System (INIS)

    Kirkpatrick, M.P.; Armfield, S.W.; Kent, J.H.

    2003-01-01

    A method is presented for representing curved boundaries for the solution of the Navier-Stokes equations on a non-uniform, staggered, three-dimensional Cartesian grid. The approach involves truncating the Cartesian cells at the boundary surface to create new cells which conform to the shape of the surface. We discuss in some detail the problems unique to the development of a cut cell method on a staggered grid. Methods for calculating the fluxes through the boundary cell faces, for representing pressure forces and for calculating the wall shear stress are derived and it is verified that the new scheme retains second-order accuracy in space. In addition, a novel 'cell-linking' method is developed which overcomes problems associated with the creation of small cells while avoiding the complexities involved with other cell-merging approaches. Techniques are presented for generating the geometric information required for the scheme based on the representation of the boundaries as quadric surfaces. The new method is tested for flow through a channel placed oblique to the grid and flow past a cylinder at Re=40 and is shown to give significant improvement over a staircase boundary formulation. Finally, it is used to calculate unsteady flow past a hemispheric protuberance on a plate at a Reynolds number of 800. Good agreement is obtained with experimental results for this flow

  19. Radial and staggered treatment patterns to correct hyperopia using noncontact holmium:YAG laser thermal keratoplasty.

    Science.gov (United States)

    Vinciguerra, P; Kohnen, T; Azzolini, M; Radice, P; Epstein, D; Koch, D D

    1998-01-01

    To compare the effects of two treatment patterns in the correction of hyperopia by noncontact holmium:YAG laser thermal keratoplasty (LTK). Divisione Oculistica, Ospedale S. Gerardo, Monza, Italy. Using two treatment patterns, we performed noncontact LTK in one session in 16 eyes of 8 patients with isometropic hyperopic refractive errors; mean preoperative subjective cycloplegic refraction was +4.90 diopters (D) +/- 1.17 (SD). The treatment consisted of 24 spots in three concentric rings of eight spots each; ring diameters were 6.0, 7.0, and 8.0 mm, respectively. Each spot received seven pulses of laser energy at 30 mJ/pulse. We treated one eye of each patient with a radial pattern (the spots of the three rings aligned on the eight semimeridians) and the fellow eye with a staggered pattern (the spots of the contiguous rings at 22.5 degrees from each other). Follow-up at 1, 15, 30, 90, 180, and 360 days included subjective cycloplegic refraction, uncorrected (UCVA) and spectacle-corrected visual acuity (SCVA), computerized videokeratography (CVK), and Scheimpflug camera examination. One year postoperatively, the mean subjective cycloplegic refraction was +2.75 +/- 1.6 D in the eyes treated with the radial pattern and +3.40 +/- 1.6 D in those treated with the staggered pattern; the mean change in subjective cycloplegic refraction was 2.15 and 1.50 D, respectively. Mean UCVA improved by five lines in the radial group and by four lines in the staggered group. Mean SCVA returned to preoperative levels by day 15 in the radial group and at 1 year in the staggered group; at 1 year, SCVA improved by one line in the radial group and remained unchanged in the staggered group. No eye lost one or more lines of SCVA. Refractive astigmatism was essentially unchanged in both groups. Scheimpflug photography and CVK indicated larger and more uniform corrected zones in the radial group. Radial and staggered patterns effectively corrected low hyperopia, although both were subject to a

  20. Modeling seismic wave propagation using staggered-grid mimetic finite differences

    Directory of Open Access Journals (Sweden)

    Freysimar Solano-Feo

    2017-04-01

    Full Text Available Mimetic finite difference (MFD approximations of continuous gradient and divergence operators satisfy a discrete version of the Gauss-Divergence theorem on staggered grids. On the mimetic approximation of this integral conservation principle, an unique boundary flux operator is introduced that also intervenes on the discretization of a given boundary value problem (BVP. In this work, we present a second-order MFD scheme for seismic wave propagation on staggered grids that discretized free surface and absorbing boundary conditions (ABC with same accuracy order. This scheme is time explicit after coupling a central three-level finite difference (FD stencil for numerical integration. Here, we briefly discuss the convergence properties of this scheme and show its higher accuracy on a challenging test when compared to a traditional FD method. Preliminary applications to 2-D seismic scenarios are also presented and show the potential of the mimetic finite difference method.

  1. Skew information in the XY model with staggered Dzyaloshinskii-Moriya interaction

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Liang, E-mail: lqiu@cumt.edu.cn [School of Physics, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China); Quan, Dongxiao [State Key Laboratory of Integrated Services Networks, Xidian University, Xi' an, Shaanxi 710071 (China); Pan, Fei; Liu, Zhi [School of Physics, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China)

    2017-06-01

    We study the performance of the lower bound of skew information in the vicinity of transition point for the anisotropic spin-1/2 XY chain with staggered Dzyaloshinskii-Moriya interaction by use of quantum renormalization-group method. For a fixed value of the Dzyaloshinskii-Moriya interaction, there are two saturated values for the lower bound of skew information corresponding to the spin-fluid and Néel phases, respectively. The scaling exponent of the lower bound of skew information closely relates to the correlation length of the model and the Dzyaloshinskii-Moriya interaction shifts the factorization point. Our results show that the lower bound of skew information can be a good candidate to detect the critical point of XY spin chain with staggered Dzyaloshinskii-Moriya interaction.

  2. Investigation of writing error in staggered heated-dot magnetic recording systems

    Science.gov (United States)

    Tipcharoen, W.; Warisarn, C.; Tongsomporn, D.; Karns, D.; Kovintavewat, P.

    2017-05-01

    To achieve an ultra-high storage capacity, heated-dot magnetic recording (HDMR) has been proposed, which heats a bit-patterned medium before recording data. Generally, an error during the HDMR writing process comes from several sources; however, we only investigate the effects of staggered island arrangement, island size fluctuation caused by imperfect fabrication, and main pole position fluctuation. Simulation results demonstrate that a writing error can be minimized by using a staggered array (hexagonal lattice) instead of a square array. Under the effect of main pole position fluctuation, the writing error is higher than the system without main pole position fluctuation. Finally, we found that the error percentage can drop below 10% when the island size is 8.5 nm and the standard deviation of the island size is 1 nm in the absence of main pole jitter.

  3. On the spectrum of the staggered Dirac operator at finite chemical potential

    International Nuclear Information System (INIS)

    Vink, J.C.; Nationaal Inst. voor Kernfysica en Hoge-Energiefysica

    1988-12-01

    The spectrum of the staggered Dirac operator in two-dimensional QEDF is investigated at finite chemical potential. In the quenced model, it is shown that lattice artefacts cause a spurious scattering of eigenvalues. This scattering disappears when lattice distance is taken to zero. In the unquenced model, a new approach is used to show that similar effects are absent. (author). 17 refs.; 6 figs

  4. Diffraction of love waves by two staggered perfectly weak half-planes

    International Nuclear Information System (INIS)

    Asghar, S.; Zaman, F.D.; Sajida Asghar

    1989-01-01

    Love wave travelling in a layer of uniform thickness overlying a half-space is assumed to be incident on two parallel but staggered perfectly weak half-planes lying in the upper layer. The diffracted fields is calculated using the modified Wiener-Hopf technique and contour integration method. The diffracted waves satisfy the dispersion relations appropriate to different regions formed by the perfectly weak half-planes

  5. Bottleneck congestion and distribution of work start times: The economics of staggered work hours revisited

    OpenAIRE

    Takayama, Yuki

    2014-01-01

    Since the seminal work of Henderson (1981), a number of studies examined the effect of staggered work hours by analyzing models of work start time choice that consider the trade-off between negative congestion externalities and positive production externalities. However, these studies described traffic congestion using flow congestion models. This study develops a model of work start time choice with bottleneck congestion and discloses the intrinsic properties of the model. To this end, this ...

  6. New 2D adaptive mesh refinement algorithm based on conservative finite-differences with staggered grid

    Science.gov (United States)

    Gerya, T.; Duretz, T.; May, D. A.

    2012-04-01

    We present new 2D adaptive mesh refinement (AMR) algorithm based on stress-conservative finite-differences formulated for non-uniform rectangular staggered grid. The refinement approach is based on a repetitive cell splitting organized via a quad-tree construction (every parent cell is split into 4 daughter cells of equal size). Irrespective of the level of resolution every cell has 5 staggered nodes (2 horizontal velocities, 2 vertical velocities and 1 pressure) for which respective governing equations, boundary conditions and interpolation equations are formulated. The connectivity of the grid is achieved via cross-indexing of grid cells and basic nodal points located in their corners: four corner nodes are indexed for every cell and up to 4 surrounding cells are indexed for every node. The accuracy of the approach depends critically on the formulation of the stencil used at the "hanging" velocity nodes located at the boundaries between different levels of resolution. Most accurate results are obtained for the scheme based on the volume flux balance across the resolution boundary combined with stress-based interpolation of velocity orthogonal to the boundary. We tested this new approach with a number of 2D variable viscosity analytical solutions. Our tests demonstrate that the adaptive staggered grid formulation has convergence properties similar to those obtained in case of a standard, non-adaptive staggered grid formulation. This convergence is also achieved when resolution boundary crosses sharp viscosity contrast interfaces. The convergence rates measured are found to be insensitive to scenarios when the transition in grid resolution crosses sharp viscosity contrast interfaces. We compared various grid refinement strategies based on distribution of different field variables such as viscosity, density and velocity. According to these tests the refinement allows for significant (0.5-1 order of magnitude) increase in the computational accuracy at the same

  7. Entropy Stable Staggered Grid Spectral Collocation for the Burgers' and Compressible Navier-Stokes Equations

    Science.gov (United States)

    Carpenter, Mark H.; Parsani, Matteo; Fisher, Travis C.; Nielsen, Eric J.

    2015-01-01

    Staggered grid, entropy stable discontinuous spectral collocation operators of any order are developed for Burgers' and the compressible Navier-Stokes equations on unstructured hexahedral elements. This generalization of previous entropy stable spectral collocation work [1, 2], extends the applicable set of points from tensor product, Legendre-Gauss-Lobatto (LGL) to a combination of tensor product Legendre-Gauss (LG) and LGL points. The new semi-discrete operators discretely conserve mass, momentum, energy and satisfy a mathematical entropy inequality for both Burgers' and the compressible Navier-Stokes equations in three spatial dimensions. They are valid for smooth as well as discontinuous flows. The staggered LG and conventional LGL point formulations are compared on several challenging test problems. The staggered LG operators are significantly more accurate, although more costly to implement. The LG and LGL operators exhibit similar robustness, as is demonstrated using test problems known to be problematic for operators that lack a nonlinearly stability proof for the compressible Navier-Stokes equations (e.g., discontinuous Galerkin, spectral difference, or flux reconstruction operators).

  8. Re: Penetration Behavior of Opposed Rows of Staggered Secondary Air Jets Depending on Jet Penetration Coefficient and Momentum Flux Ratio

    Science.gov (United States)

    Holdeman, James D.

    2016-01-01

    The purpose of this article is to explain why the extension of the previously published C = (S/Ho)sqrt(J) scaling for opposed rows of staggered jets wasn't directly successful in the study by Choi et al. (2016). It is not surprising that staggered jets from opposite sides do not pass each other at the expected C value, because Ho/D and sqrt(J) are much larger than the maximum in previous studies. These, and large x/D's, tend to suggest development of 2-dimensional flow. Although there are distinct optima for opposed rows of in-line jets, single-side injection, and opposed rows of staggered jets based on C, opposed rows of staggered jets provide as good or better mixing performance, at any C value, than opposed rows of in-line jets or jets from single-side injection.

  9. Channelling and channelling radiation

    International Nuclear Information System (INIS)

    Soerensen, A.H.; Uggerhoej, E.

    1987-01-01

    The study of channelling phenomena has developed rapidly since the early 1960s and today channelling has found many applications. The radiation emitted by channelled megaelectronvolt and gigaelectronvolt electrons and positrons has been investigated extensively and the possibility of, for example, constructing intense tunable X- and γ-ray sources is being explored. Multi-gigaelectronvolt radiation and pair-creation processes in single crystals show similarities with strong-field effects and are of particular interest because of high production rates that persist far beyond the channelling regime. (author)

  10. Integral staggered point-matching method for millimeter-wave reflective diffraction gratings on electron cyclotron heating systems

    International Nuclear Information System (INIS)

    Xia, Donghui; Huang, Mei; Wang, Zhijiang; Zhang, Feng; Zhuang, Ge

    2016-01-01

    Highlights: • The integral staggered point-matching method for design of polarizers on the ECH systems is presented. • The availability of the integral staggered point-matching method is checked by numerical calculations. • Two polarizers are designed with the integral staggered point-matching method and the experimental results are given. - Abstract: The reflective diffraction gratings are widely used in the high power electron cyclotron heating systems for polarization strategy. This paper presents a method which we call “the integral staggered point-matching method” for design of reflective diffraction gratings. This method is based on the integral point-matching method. However, it effectively removes the convergence problems and tedious calculations of the integral point-matching method, making it easier to be used for a beginner. A code is developed based on this method. The calculation results of the integral staggered point-matching method are compared with the integral point-matching method, the coordinate transformation method and the low power measurement results. It indicates that the integral staggered point-matching method can be used as an optional method for the design of reflective diffraction gratings in electron cyclotron heating systems.

  11. Pseudo-spectral method using rotated staggered grid for elastic wave propagation in 3D arbitrary anisotropic media

    KAUST Repository

    Zou, Peng

    2017-05-10

    Staggering grid is a very effective way to reduce the Nyquist errors and to suppress the non-causal ringing artefacts in the pseudo-spectral solution of first-order elastic wave equations. However, the straightforward use of a staggered-grid pseudo-spectral method is problematic for simulating wave propagation when the anisotropy level is greater than orthorhombic or when the anisotropic symmetries are not aligned with the computational grids. Inspired by the idea of rotated staggered-grid finite-difference method, we propose a modified pseudo-spectral method for wave propagation in arbitrary anisotropic media. Compared with an existing remedy of staggered-grid pseudo-spectral method based on stiffness matrix decomposition and a possible alternative using the Lebedev grids, the rotated staggered-grid-based pseudo-spectral method possesses the best balance between the mitigation of artefacts and efficiency. A 2D example on a transversely isotropic model with tilted symmetry axis verifies its effectiveness to suppress the ringing artefacts. Two 3D examples of increasing anisotropy levels demonstrate that the rotated staggered-grid-based pseudo-spectral method can successfully simulate complex wavefields in such anisotropic formations.

  12. Integral staggered point-matching method for millimeter-wave reflective diffraction gratings on electron cyclotron heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Donghui [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China); Huang, Mei [Southwestern Institute of Physics, 610041 Chengdu (China); Wang, Zhijiang, E-mail: wangzj@hust.edu.cn [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China); Zhang, Feng [Southwestern Institute of Physics, 610041 Chengdu (China); Zhuang, Ge [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China)

    2016-10-15

    Highlights: • The integral staggered point-matching method for design of polarizers on the ECH systems is presented. • The availability of the integral staggered point-matching method is checked by numerical calculations. • Two polarizers are designed with the integral staggered point-matching method and the experimental results are given. - Abstract: The reflective diffraction gratings are widely used in the high power electron cyclotron heating systems for polarization strategy. This paper presents a method which we call “the integral staggered point-matching method” for design of reflective diffraction gratings. This method is based on the integral point-matching method. However, it effectively removes the convergence problems and tedious calculations of the integral point-matching method, making it easier to be used for a beginner. A code is developed based on this method. The calculation results of the integral staggered point-matching method are compared with the integral point-matching method, the coordinate transformation method and the low power measurement results. It indicates that the integral staggered point-matching method can be used as an optional method for the design of reflective diffraction gratings in electron cyclotron heating systems.

  13. EM reconstruction of dual isotope PET using staggered injections and prompt gamma positron emitters

    International Nuclear Information System (INIS)

    Andreyev, Andriy; Sitek, Arkadiusz; Celler, Anna

    2014-01-01

    Purpose: The aim of dual isotope positron emission tomography (DIPET) is to create two separate images of two coinjected PET radiotracers. DIPET shortens the duration of the study, reduces patient discomfort, and produces perfectly coregistered images compared to the case when two radiotracers would be imaged independently (sequential PET studies). Reconstruction of data from such simultaneous acquisition of two PET radiotracers is difficult because positron decay of any isotope creates only 511 keV photons; therefore, the isotopes cannot be differentiated based on the detected energy. Methods: Recently, the authors have proposed a DIPET technique that uses a combination of radiotracer A which is a pure positron emitter (such as 18 F or 11 C) and radiotracer B in which positron decay is accompanied by the emission of a high-energy (HE) prompt gamma (such as 38 K or 60 Cu). Events that are detected as triple coincidences of HE gammas with the corresponding two 511 keV photons allow the authors to identify the lines-of-response (LORs) of isotope B. These LORs are used to separate the two intertwined distributions, using a dedicated image reconstruction algorithm. In this work the authors propose a new version of the DIPET EM-based reconstruction algorithm that allows the authors to include an additional, independent estimate of radiotracer A distribution which may be obtained if radioisotopes are administered using a staggered injections method. In this work the method is tested on simple simulations of static PET acquisitions. Results: The authors’ experiments performed using Monte-Carlo simulations with static acquisitions demonstrate that the combined method provides better results (crosstalk errors decrease by up to 50%) than the positron-gamma DIPET method or staggered injections alone. Conclusions: The authors demonstrate that the authors’ new EM algorithm which combines information from triple coincidences with prompt gammas and staggered injections

  14. On the Quality of Velocity Interpolation Schemes for Marker-in-Cell Method and Staggered Grids

    Science.gov (United States)

    Pusok, Adina E.; Kaus, Boris J. P.; Popov, Anton A.

    2017-03-01

    The marker-in-cell method is generally considered a flexible and robust method to model the advection of heterogenous non-diffusive properties (i.e., rock type or composition) in geodynamic problems. In this method, Lagrangian points carrying compositional information are advected with the ambient velocity field on an Eulerian grid. However, velocity interpolation from grid points to marker locations is often performed without considering the divergence of the velocity field at the interpolated locations (i.e., non-conservative). Such interpolation schemes can induce non-physical clustering of markers when strong velocity gradients are present (Journal of Computational Physics 166:218-252, 2001) and this may, eventually, result in empty grid cells, a serious numerical violation of the marker-in-cell method. To remedy this at low computational costs, Jenny et al. (Journal of Computational Physics 166:218-252, 2001) and Meyer and Jenny (Proceedings in Applied Mathematics and Mechanics 4:466-467, 2004) proposed a simple, conservative velocity interpolation scheme for 2-D staggered grid, while Wang et al. (Geochemistry, Geophysics, Geosystems 16(6):2015-2023, 2015) extended the formulation to 3-D finite element methods. Here, we adapt this formulation for 3-D staggered grids (correction interpolation) and we report on the quality of various velocity interpolation methods for 2-D and 3-D staggered grids. We test the interpolation schemes in combination with different advection schemes on incompressible Stokes problems with strong velocity gradients, which are discretized using a finite difference method. Our results suggest that a conservative formulation reduces the dispersion and clustering of markers, minimizing the need of unphysical marker control in geodynamic models.

  15. Response of Maize Crop to Spatial Arrangement and Staggered Interseeding of Haricot Bean

    Directory of Open Access Journals (Sweden)

    Tamiru Hirpa

    2014-09-01

    Full Text Available Field studies conducted to determine the effects of intercrop row arrangements and staggered intercropping of haricot bean (Phaseolus vulgaris L. on the performances of maize (Zea mays L. crop at Hallaba and Taba areas in 2013 cropping season, southern Ethiopia, revealed that there were significant effects of cropping patterns and staggered interseeding of the legume component on growth and yield components of maize crop. Significant interaction of row arrangement × intercropping time of haricot bean was observed with respect to leaf area index (LAI of the maize crop. Increasing trends of LAI of maize crop were observed as interseeding of haricot bean was delayed for 3 weeks after maize (WAM that stabilized during the 6 WAM interseeding time. Maize stover production was significantly high at 1:2 row ratio and delaying of the undersowing haricot bean in the already established maize crop for 6 weeks, 10.94 tha-1 and 11.39 t ha-1, respectively. Maize grain yield showed a significant variation with respect to the staggered sowing of haricot bean, whereby the highest (3.99 t ha-1 being recorded when haricot bean intercropping was delayed for 21 days after maize planting. The data of this study revealed that the larger maize plant canopy providing larger photosynthetic area, attained when haricot bean interseeding was delayed, probably resulted in higher grain yield of maize. DOI: http://dx.doi.org/10.3126/ije.v3i3.11072 International Journal of Environment Vol.3(3 2014: 126-138

  16. EM reconstruction of dual isotope PET using staggered injections and prompt gamma positron emitters

    Science.gov (United States)

    Andreyev, Andriy; Sitek, Arkadiusz; Celler, Anna

    2014-01-01

    Purpose: The aim of dual isotope positron emission tomography (DIPET) is to create two separate images of two coinjected PET radiotracers. DIPET shortens the duration of the study, reduces patient discomfort, and produces perfectly coregistered images compared to the case when two radiotracers would be imaged independently (sequential PET studies). Reconstruction of data from such simultaneous acquisition of two PET radiotracers is difficult because positron decay of any isotope creates only 511 keV photons; therefore, the isotopes cannot be differentiated based on the detected energy. Methods: Recently, the authors have proposed a DIPET technique that uses a combination of radiotracer A which is a pure positron emitter (such as 18F or 11C) and radiotracer B in which positron decay is accompanied by the emission of a high-energy (HE) prompt gamma (such as 38K or 60Cu). Events that are detected as triple coincidences of HE gammas with the corresponding two 511 keV photons allow the authors to identify the lines-of-response (LORs) of isotope B. These LORs are used to separate the two intertwined distributions, using a dedicated image reconstruction algorithm. In this work the authors propose a new version of the DIPET EM-based reconstruction algorithm that allows the authors to include an additional, independent estimate of radiotracer A distribution which may be obtained if radioisotopes are administered using a staggered injections method. In this work the method is tested on simple simulations of static PET acquisitions. Results: The authors’ experiments performed using Monte-Carlo simulations with static acquisitions demonstrate that the combined method provides better results (crosstalk errors decrease by up to 50%) than the positron-gamma DIPET method or staggered injections alone. Conclusions: The authors demonstrate that the authors’ new EM algorithm which combines information from triple coincidences with prompt gammas and staggered injections improves

  17. Weak interaction matrix elements with staggered fermions. I: theory and a trial run

    International Nuclear Information System (INIS)

    Sharpe, S.R.; Patel, A.; Gupta, R.; Guralnik, G.; Kilsup, G.W.

    1986-08-01

    We present results of a preliminary study of the matrix elements of weak interaction operators using staggered fermions. We describe our method for transcribing the weak interaction Hamiltonian onto the lattice. This method preserves exact Ward Identities analogous to those of the continuum. The calculation uses operators involving 0, 1, 2, 3 and 4 gauge links. We present results for all these operators obtained on 8 3 x 16 lattices generated both with the Wilson action (β = 5.6) and an improved action

  18. Nucleon structure in the chiral regime with domain wall fermions on an improved staggered sea

    International Nuclear Information System (INIS)

    R.G. Edwards; G. Fleming; Ph. Hagler; J.W. Negele; K. Orginos; A.V. Pochinsky; D.B. Renner; D.G. Richards; W. Schroers

    2006-01-01

    Moments of unpolarized, helicity, and transversity distributions, electromagnetic form factors, and generalized form factors of the nucleon are presented from a preliminary analysis of lattice results using pion masses down to 359 MeV. The twist two matrix elements are calculated using a mixed action of domain wall valence quarks and asqtad staggered sea quarks and are renormalized perturbatively. Several observables are extrapolated to the physical limit using chiral perturbation theory. Results are compared with experimental moments of quark distributions and electromagnetic form factors and phenomenologically determined generalized form factors, and the implications on the transverse structure and spin content of the nucleon are discussed

  19. Aerodynamic drag of a staggered flat-oval finning tube banks at the small reynolds numbers

    Directory of Open Access Journals (Sweden)

    Максим Михайлович Вознюк

    2015-06-01

    Full Text Available Experimental investigations of aerodynamic drag of staggered bundles of flat-oval tubes with incomplete transversal fins in the range of Reynolds numbers 600 <  < 20000 are performed. New calculation correlations for determining of drag coefficients for 1<3000 are suggested, the impact of basic geometric and regime parameters on aerodynamic drag of bundles are determined. The received calculation depending is possible to use in developing of heat transfer surfaces for “dry” cooling towers and air cooling apparatus and economizers

  20. Calculation of cell face velocity of non-staggered grid system

    KAUST Repository

    Li, Wang

    2012-07-28

    In this paper, the cell face velocities in the discretization of the continuity equation, the momentum equation, and the scalar equation of a non-staggered grid system are calculated and discussed. Both the momentum interpolation and the linear interpolation are adopted to evaluate the coefficients in the discretized momentum and scalar equations. Their performances are compared. When the linear interpolation is used to calculate the coefficients, the mass residual term in the coefficients must be dropped to maintain the accuracy and convergence rate of the solution. © Shanghai University and Springer-Verlag Berlin Heidelberg 2012.

  1. Calculation of the Nucleon Axial Form Factor Using Staggered Lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Aaron S. [Fermilab; Hill, Richard J. [Perimeter Inst. Theor. Phys.; Kronfeld, Andreas S. [Fermilab; Li, Ruizi [Indiana U.; Simone, James N. [Fermilab

    2016-10-14

    The nucleon axial form factor is a dominant contribution to errors in neutrino oscillation studies. Lattice QCD calculations can help control theory errors by providing first-principles information on nucleon form factors. In these proceedings, we present preliminary results on a blinded calculation of $g_A$ and the axial form factor using HISQ staggered baryons with 2+1+1 flavors of sea quarks. Calculations are done using physical light quark masses and are absolutely normalized. We discuss fitting form factor data with the model-independent $z$ expansion parametrization.

  2. Staggered-electromagnetophoresis with a Split-flow System for the Separation of Microparticles by a Hollow Fiber-embedded PDMS Microchip.

    Science.gov (United States)

    Iiguni, Yoshinori; Tanaka, Ayaka; Kitagawa, Shinya; Ohtani, Hajime

    2016-01-01

    A novel microchip separation system for microparticles based on electromagnetophoresis (EMP) was developed. In this system, focusing and separation of flowing microparticles in a microchannel could be performed by staggered-EMP by controlling the electric current applied to the channel locally combined with the split-flow system for fractionation of eluates. To apply the electric current through the flushing medium in the microchannel, a hollow fiber-embedded microchip with multiple electrodes was fabricated. The hollow fiber was made by a semi-permeable membrane and could separate small molecules. This microchip allowed us to apply the electric current to a part of the microchannel without any pressure control device because a main channel contacted with the subchannels that had electrodes through the semi-permeable membrane. Moreover, the separation using this microchip was combined with the split-flow system at two outlets to improve separation efficiency. Using this system, with the split-flow ratio of 10:1, 87% of 3 μm polystyrene (PS) latex particles were isolated from a mixture of 3 and 10 μm particles. Even the separation of 6 and 10 μm PS particles was achieved with about 77% recovery and 100% purity. In addition, by controlling the applied current, size fractionation of polypropylene (PP) particles was demonstrated. Moreover, biological particles such as pollens could be separated with high separation efficiency by this technique.

  3. Cas9-catalyzed DNA Cleavage Generates Staggered Ends: Evidence from Molecular Dynamics Simulations

    Science.gov (United States)

    Zuo, Zhicheng; Liu, Jin

    2016-11-01

    The CRISPR-associated endonuclease Cas9 from Streptococcus pyogenes (spCas9) along with a single guide RNA (sgRNA) has emerged as a versatile toolbox for genome editing. Despite recent advances in the mechanism studies on spCas9-sgRNA-mediated double-stranded DNA (dsDNA) recognition and cleavage, it is still unclear how the catalytic Mg2+ ions induce the conformation changes toward the catalytic active state. It also remains controversial whether Cas9 generates blunt-ended or staggered-ended breaks with overhangs in the DNA. To investigate these issues, here we performed the first all-atom molecular dynamics simulations of the spCas9-sgRNA-dsDNA system with and without Mg2+ bound. The simulation results showed that binding of two Mg2+ ions at the RuvC domain active site could lead to structurally and energetically favorable coordination ready for the non-target DNA strand cleavage. Importantly, we demonstrated with our simulations that Cas9-catalyzed DNA cleavage produces 1-bp staggered ends rather than generally assumed blunt ends.

  4. Parametric modeling and stagger angle optimization of an axial flow fan

    International Nuclear Information System (INIS)

    Li, M X; Zhang, C H; Liu, Y; Zheng, S Y

    2013-01-01

    Axial flow fans are widely used in every field of social production. Improving their efficiency is a sustained and urgent demand of domestic industry. The optimization of stagger angle is an important method to improve fan performance. Parametric modeling and calculation process automation are realized in this paper to improve optimization efficiency. Geometric modeling and mesh division are parameterized based on GAMBIT. Parameter setting and flow field calculation are completed in the batch mode of FLUENT. A control program is developed in Visual C++ to dominate the data exchange of mentioned software. It also extracts calculation results for optimization algorithm module (provided by Matlab) to generate directive optimization control parameters, which as feedback are transferred upwards to modeling module. The center line of the blade airfoil, based on CLARK y profile, is constructed by non-constant circulation and triangle discharge method. Stagger angles of six airfoil sections are optimized, to reduce the influence of inlet shock loss as well as gas leak in blade tip clearance and hub resistance at blade root. Finally an optimal solution is obtained, which meets the total pressure requirement under given conditions and improves total pressure efficiency by about 6%

  5. Parametric modeling and stagger angle optimization of an axial flow fan

    Science.gov (United States)

    Li, M. X.; Zhang, C. H.; Liu, Y.; Y Zheng, S.

    2013-12-01

    Axial flow fans are widely used in every field of social production. Improving their efficiency is a sustained and urgent demand of domestic industry. The optimization of stagger angle is an important method to improve fan performance. Parametric modeling and calculation process automation are realized in this paper to improve optimization efficiency. Geometric modeling and mesh division are parameterized based on GAMBIT. Parameter setting and flow field calculation are completed in the batch mode of FLUENT. A control program is developed in Visual C++ to dominate the data exchange of mentioned software. It also extracts calculation results for optimization algorithm module (provided by Matlab) to generate directive optimization control parameters, which as feedback are transferred upwards to modeling module. The center line of the blade airfoil, based on CLARK y profile, is constructed by non-constant circulation and triangle discharge method. Stagger angles of six airfoil sections are optimized, to reduce the influence of inlet shock loss as well as gas leak in blade tip clearance and hub resistance at blade root. Finally an optimal solution is obtained, which meets the total pressure requirement under given conditions and improves total pressure efficiency by about 6%.

  6. Experimental study of thermal–hydraulic performance of cam-shaped tube bundle with staggered arrangement

    International Nuclear Information System (INIS)

    Bayat, Hamidreza; Lavasani, Arash Mirabdolah; Maarefdoost, Taher

    2014-01-01

    Highlights: • Thermal–hydraulic performance of a non-circular tube bundle has been investigated experimentally. • Tubes were mounted in staggered arrangement with two longitudinal pitch ratios 1.5 and 2. • Drag coefficient and Nusselt number of tubes in second row was measured. • Friction factor of this tube bundle is lower than circular tube bundle. • Thermal–hydraulic performance of this tube bundle is greater than circular tube bundle. - Abstract: Flow and heat transfer from cam-shaped tube bank in staggered arrangement is studied experimentally. Tubes were located in test section of an open loop wind tunnel with two longitudinal pitch ratios 1.5 and 2. Reynolds number varies in range of 27,000 ⩽ Re D ⩽ 42,500 and tubes surface temperature is between 78 and 85 °C. Results show that both drag coefficient and Nusselt number depends on position of tube in tube bank and Reynolds number. Tubes in the first column have maximum value of drag coefficient, while its Nusselt number is minimum compared to other tubes in tube bank. Moreover, pressure drop from this tube bank is about 92–93% lower than circular tube bank and as a result thermal–hydraulic performance of this tube bank is about 6 times greater than circular tube bank

  7. Analysis of the influence of the interlayer staggered zone in the basalt of Jinsha River Basin on the main buildings

    Science.gov (United States)

    Guo, Qiaona; Huang, Jiangwei

    2018-02-01

    In this paper, the finite element software FEFLOW is used to simulate the seepage field of the interlayer staggered zone C2 in the basalt of Jinsha River Basin. The influence of the interlayer staggered zone C2 on the building is analyzed. Combined with the waterproof effect of current design scheme of anti-seepage curtain, the seepage field in the interlayer staggered zone C2 is discussed under different design schemes. The optimal design scheme of anti-seepage curtain is put forward. The results showed that the case four can effectively reduce the head and hydraulic gradient of underground powerhouse area, and improve the groundwater seepage field in the plant area.

  8. Energy Stability Analysis of Some Fully Discrete Numerical Schemes for Incompressible Navier–Stokes Equations on Staggered Grids

    KAUST Repository

    Chen, Huangxin

    2017-09-01

    In this paper we consider the energy stability estimates for some fully discrete schemes which both consider time and spatial discretizations for the incompressible Navier–Stokes equations. We focus on three kinds of fully discrete schemes, i.e., the linear implicit scheme for time discretization with the finite difference method (FDM) on staggered grids for spatial discretization, pressure-correction schemes for time discretization with the FDM on staggered grids for the solutions of the decoupled velocity and pressure equations, and pressure-stabilization schemes for time discretization with the FDM on staggered grids for the solutions of the decoupled velocity and pressure equations. The energy stability estimates are obtained for the above each fully discrete scheme. The upwind scheme is used in the discretization of the convection term which plays an important role in the design of unconditionally stable discrete schemes. Numerical results are given to verify the theoretical analysis.

  9. High‐order rotated staggered finite difference modeling of 3D elastic wave propagation in general anisotropic media

    KAUST Repository

    Chu, Chunlei

    2009-01-01

    We analyze the dispersion properties and stability conditions of the high‐order convolutional finite difference operators and compare them with the conventional finite difference schemes. We observe that the convolutional finite difference method has better dispersion properties and becomes more efficient than the conventional finite difference method with the increasing order of accuracy. This makes the high‐order convolutional operator a good choice for anisotropic elastic wave simulations on rotated staggered grids since its enhanced dispersion properties can help to suppress the numerical dispersion error that is inherent in the rotated staggered grid structure and its efficiency can help us tackle 3D problems cost‐effectively.

  10. Towards corrections to the strong coupling limit of staggered lattice QCD

    CERN Document Server

    Fromm, Michael; Philipsen, Owe; de Forcrand, Philippe; Unger, Wolfgang; Miura, Kotaroh

    2011-01-01

    We report on the first steps of an ongoing project to add gauge observables and gauge corrections to the well-studied strong coupling limit of staggered lattice QCD, which has been shown earlier to be amenable to numerical simulations by the worm algorithm in the chiral limit and at finite density. Here we show how to evaluate the expectation value of the Polyakov loop in the framework of the strong coupling limit at finite temperature, allowing to study confinement properties along with those of chiral symmetry breaking. We find the Polyakov loop to rise smoothly, thus signalling deconfinement. The non-analytic nature of the chiral phase transition is reflected in the derivative of the Polyakov loop. We also discuss how to construct an effective theory for non-zero lattice coupling, which is valid to $O(\\beta)$.

  11. Field theory of a terahertz staggered double-grating arrays waveguide Cerenkov traveling wave amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wenqiu; He, Fangming [Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Zicheng; Luo, Jirun; Zhao, Ding; Liu, Qinglun [Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-04-15

    Based on a rectilinear sheet electron beam propagating through the tunnel of a staggered double-grating arrays waveguide (SDGAW) slow-wave structure (SWS), a three dimensional field theory for describing the modes and the beam-wave interaction is presented, in which the higher order terms inside the grooves are retained. The fields' distribution and the conductivity losses are also calculated utilizing the theoretical model. With the optimized parameters of the SWS and the electron beam, a 1 THz SDGAW Cerenkov traveling wave amplifier may obtain a moderate net gain (the peak gain is 12.7 dB/cm) and an ultra 3 dB wideband (0.19 THz) considering the serious Ohmic losses. The theoretical results have been compared with those calculated by 3D HFSS code and CST STUDIO particle-in-cell simulations.

  12. N{sub f}=1 QCD in external magnetic fields: staggered fermions

    Energy Technology Data Exchange (ETDEWEB)

    Cea, Paolo [INFN, Sezione di Bari, Via Amendola 173, I-70126 Bari (Italy); Dipartimento di Fisica dell’Università di Bari, Via Amendola 173, I-70126 Bari (Italy); Cosmai, Leonardo [INFN, Sezione di Bari, Via Amendola 173, I-70126 Bari (Italy)

    2015-12-10

    We investigate N{sub f}=1 QCD in external magnetic fields on the lattice. The background field is introduced by means of the so-called Schrödinger functional. We adopt standard staggered fermions with constant bare mass am=0.025 and magnetic fields with constant magnetic flux up to a{sup 2}eH≃2.3562. We find that the the deconfinement and chiral symmetry restoration temperatures do not depend on the strength of the applied magnetic field. Our method allow us to easily study the effects of the external magnetic fields on the QCD thermodynamics. We determine the influences of applied magnetic fields to the free energy, pressure, and equation of state of strongly interacting matter.

  13. Constitutive Modelling in Thermomechanical Processes, Using The Control Volume Method on Staggered Grid

    DEFF Research Database (Denmark)

    Thorborg, Jesper

    -strain relation has been suggested. The intention of this method is to provide fast numerical results with reasonable accuracy in relation to the first order effects of the presented classical plasticity model. Application of the $J_2$ flow theory and the alternative method have shown some agreement...... of the method has been focused on high temperature processes such as casting and welding and the interest of using nonlinear constitutive stress-strain relations has grown to extend the applicability of the method. The work of implementing classical plasticity into the control volume formulation has been based...... on the $J_2$ flow theory describing an isotropic hardening material with a temperature dependent yield stress. This work has successfully been verified by comparing results to analytical solutions. Due to the comprehensive implementation in the staggered grid an alternative constitutive stress...

  14. An arbitrary-order staggered time integrator for the linear acoustic wave equation

    Science.gov (United States)

    Lee, Jaejoon; Park, Hyunseo; Park, Yoonseo; Shin, Changsoo

    2018-02-01

    We suggest a staggered time integrator whose order of accuracy can arbitrarily be extended to solve the linear acoustic wave equation. A strategy to select the appropriate order of accuracy is also proposed based on the error analysis that quantitatively predicts the truncation error of the numerical solution. This strategy not only reduces the computational cost several times, but also allows us to flexibly set the modelling parameters such as the time step length, grid interval and P-wave speed. It is demonstrated that the proposed method can almost eliminate temporal dispersive errors during long term simulations regardless of the heterogeneity of the media and time step lengths. The method can also be successfully applied to the source problem with an absorbing boundary condition, which is frequently encountered in the practical usage for the imaging algorithms or the inverse problems.

  15. Staggered-Grid Finite Difference Method with Variable-Order Accuracy for Porous Media

    Directory of Open Access Journals (Sweden)

    Jinghuai Gao

    2013-01-01

    Full Text Available The numerical modeling of wave field in porous media generally requires more computation time than that of acoustic or elastic media. Usually used finite difference methods adopt finite difference operators with fixed-order accuracy to calculate space derivatives for a heterogeneous medium. A finite difference scheme with variable-order accuracy for acoustic wave equation has been proposed to reduce the computation time. In this paper, we develop this scheme for wave equations in porous media based on dispersion relation with high-order staggered-grid finite difference (SFD method. High-order finite difference operators are adopted for low-velocity regions, and low-order finite difference operators are adopted for high-velocity regions. Dispersion analysis and modeling results demonstrate that the proposed SFD method can decrease computational costs without reducing accuracy.

  16. Stress analysis of three-dimensional roadway layout of stagger arrangement with field observation

    Science.gov (United States)

    Cui, Zimo; Chanda, Emmanuel; Zhao, Jingli; Wang, Zhihe

    2018-01-01

    Longwall top-coal caving (LTCC) has been a popular, more productive and cost-effective method for extracting thick (> 5 m) to ultra-thick coal seams in recent years. However, low-level recovery ratio of coal resources and top-coal loss above the supports at both ends of working face are long-term problems. Geological factors, such as large dip angle, soft rock, mining depth further complicate the problems. This paper proposes addressing this issue by adopting three-dimensional roadway layout of stagger arrangement (3-D RLSA). In this study, the first step was to analyse the stress environment surrounding head entry in the replacing working face based on the stress distribution characteristics at the triangular coal-pillar side in gob and the stress slip line field theory. In the second step, filed observation was conducted. Finally, an economic evaluation of the 3-D RLSA for extracting thick to ultra-thick seams was conducted.

  17. Cellular uptake of magnetite nanoparticles enhanced by NdFeB magnets in staggered arrangement

    Science.gov (United States)

    Lu, Yi-Ching; Chang, Fan-Yu; Tu, Shu-Ju; Chen, Jyh-Ping; Ma, Yunn-Hwa

    2017-04-01

    Magnetic force may greatly enhance uptake of magnetic nanoparticles (MNPs) by cultured cells; however, the effects of non-uniformity of magnetic field/ magnetic gradient on MNP internalization in culture has not been elucidated. Cellular uptake of polyacrylic acid coated-MNP by LN229 cells was measured with cylindrical NdFeB magnets arranged in a staggered pattern. The magnetic field generated by placing a magnet underneath (H-field) elicited a homogenous distribution of MNPs on the cells in culture; whereas the field without magnet underneath (L-field) resulted in MNP distribution along the edge of the wells. Cell-associated MNP (MNPcell) appeared to be magnetic field- and concentration-dependent. In H-field, MNPcell reached plateau within one hour of exposure to MNP with only one-min application of the magnetic force in the beginning of incubation; continuous presence of the magnet for 2 h did not further increase MNPcell, suggesting that magnetic force-induced uptake may be primarily contributed to enhanced MNP sedimentation. Although MNP distribution was much inhomogeneous in L-field, averaged MNPcell in the L-field may reach as high as 80% of that in H-field during 1-6 h incubation, suggesting high capacity of MNP internalization. In addition, no significant difference was observed in MNPcell analyzed by flow cytometry with the application of H-field of staggered plate vs. filled magnet plate. Therefore, biological variation may dominate MNP internalization even under relatively uniformed magnetic field; whereas non-uniformed magnetic field may serve as a model for tumor targeting with MNPs in vivo.

  18. A comparative study of Purkinje cells in two RORalpha gene mutant mice: staggerer and RORalpha(-/-).

    Science.gov (United States)

    Doulazmi, M; Frédéric, F; Capone, F; Becker-André, M; Delhaye-Bouchaud, N; Mariani, J

    2001-04-30

    The staggerer (Rora(sg/sg)) mutation is a deletion in the RORalpha gene, one member of a family of nuclear receptor genes related to the retinoic acid receptor. Recently Steinmayr et al. (Proc. Natl. Acad. Sci. USA 95 (1998) 3960) generated a RORalpha null-mutant mouse (Rora(-/-)) by using a targeting vector in which a beta-Gal gene replaces the second finger of the DNA-binding domain of RORalpha. The Rora(-/-) cerebellum is qualitatively a phenocopy of the Rora(sg/sg) one, but the two strains differ slightly in their motor skills. To address the question whether the morphological defects in the Rora(-/-) cerebellum are identical to the Rora(sg/sg) one, we compared number and size of Purkinje cells in both staggerer and RORalpha null-mutant mice, using calbindin (CaBP) immunohistochemistry and revelation of beta-Gal activity. Compared to control cerebella the Rora(sg/sg) cerebellum has 82% fewer CaBP-positive cells. In Rora(-/-) mouse, all the the beta-Gal-positive Purkinje cells also expressed CaBP, but the cerebellum contained 78% less CaBP-positive cells than control, a deficit not different from the one observed in Rora(sg/sg). We show similar mediolateral compartments in Purkinje cell number and cytological abnormality in Rora(sg/sg) and Rora(-/-) mice. These results provide quantitative support for the hypothesis that the cerebellar phenotype in the homozygous Rora(sg/sg) is due to the lack of function of the RORalpha gene.

  19. Investigation of analog/RF performance of staggered heterojunctions based nanowire tunneling field-effect transistors

    Science.gov (United States)

    Chakraborty, Avik; Sarkar, Angsuman

    2015-04-01

    In this paper, the analog/RF performance of an III-V semiconductor based staggered hetero-tunnel-junction (HETJ) n-type nanowire (NW) tunneling FET (n-TFET) is investigated, for the first time. The device performance figure-of-merits governing the analog/RF performance such as transconductance (gm), transconductance-to-drive current ratio (gm/IDS), output resistance (Rout), intrinsic gain and unity-gain cutoff frequency (fT) have been studied. The analog/RF performance parameters is compared between HETJ NW TFET and a homojunction (HJ) NW n-type TFET of similar dimensions. In addition to enhanced ION and subthreshold swing, a significant improvement in the analog/RF performance parameters obtained by the HETJ n-TFET over HJ counterpart for use in analog/mixed signal System-on-Chip (SoC) applications is reported. Moreover, the analog/RF performance parameters of a III-V based staggered HETJ NW TFET is also compared with a heterojunction (HETJ) NW n-type MOSFET having same material as HETJ n-TFET and equal dimension in order to provide a systematic comparison between HETJ-TFET and HETJ-MOSFET for use in analog/mixed-signal applications. The results reveal that HETJ n-TFET provides higher Rout and hence, a higher intrinsic gain, an improved gm/IDS ratio, and reasonable fT at lower values of gate-overdrive voltage as compared to the HETJ NW n-MOSFET.

  20. A Study of a Powder Coating Gun Near Field: Particle Flow in an Isothermal Staggered Concentric Air Jet

    Directory of Open Access Journals (Sweden)

    Graham Payne

    2014-07-01

    Full Text Available An experimental study of inert particle dispersion in an isothermal concentric air jet near field was conducted for cases of standard non-staggered and alternative staggered jet nozzles, each taken from a polymer powder flame deposition gun. The experimental work consisted of analysis of high speed digital images of the inert two phase isothermal jet flow, illuminated by a laser light sheet along and across the jet axis. The analysis of particle spread in the jet, represented by families of particle density distributions, clearly showed that the staggered nozzles resulted in a better-focused flow, with narrower distributions in the near field, and in the elimination of the recirculation zone that disrupted the particle flow in a non-staggered nozzle arrangement. In all cases, histograms of the cross-sectional particle area density were found to be approximately Gaussian. It was also found that there was a wide variation in the size and shape of the ground polymer particles used and these two characteristics caused a wide variation in the radial and axial velocities of the particles. Despite the differences between single-phase numerical simulations and experimental results, reported in Payne et al. [1], the introduction of particles into a numerical model produced satisfactory agreement with the particle velocities found experimentally.

  1. The sequential organ failure assessment (SOFA) score is an effective triage marker following staggered paracetamol (acetaminophen) overdose.

    Science.gov (United States)

    Craig, D G; Zafar, S; Reid, T W D J; Martin, K G; Davidson, J S; Hayes, P C; Simpson, K J

    2012-06-01

    The sequential organ failure assessment (SOFA) score is an effective triage marker following single time point paracetamol (acetaminophen) overdose, but has not been evaluated following staggered (multiple supratherapeutic doses over >8 h, resulting in cumulative dose of >4 g/day) overdoses. To evaluate the prognostic accuracy of the SOFA score following staggered paracetamol overdose. Time-course analysis of 50 staggered paracetamol overdoses admitted to a tertiary liver centre. Individual timed laboratory samples were correlated with corresponding clinical parameters and the daily SOFA scores were calculated. A total of 39/50 (78%) patients developed hepatic encephalopathy. The area under the SOFA receiver operator characteristic for death/liver transplantation was 87.4 (95% CI 73.2-95.7), 94.3 (95% CI 82.5-99.1), and 98.4 (95% CI 84.3-100.0) at 0, 24 and 48 h, respectively, postadmission. A SOFA score of paracetamol overdose, is associated with a good prognosis. Both the SOFA and APACHE II scores could improve triage of high-risk staggered paracetamol overdose patients. © 2012 Blackwell Publishing Ltd.

  2. Staggered overdose pattern and delay to hospital presentation are associated with adverse outcomes following paracetamol-induced hepatotoxicity.

    Science.gov (United States)

    Craig, Darren G N; Bates, Caroline M; Davidson, Janice S; Martin, Kirsty G; Hayes, Peter C; Simpson, Kenneth J

    2012-02-01

    Paracetamol (acetaminophen) poisoning remains the major cause of severe acute hepatotoxicity in the UK. In this large single centre cohort study we examined the clinical impact of staggered overdoses and delayed presentation following paracetamol overdose. Between 1992 and 2008, 663 patients were admitted with paracetamol-induced severe liver injury, of whom 161 (24.3%) had taken a staggered overdose. Staggered overdose patients were significantly older and more likely to abuse alcohol than single time point overdose patients. Relief of pain (58.2%) was the commonest rationale for repeated supratherapeutic ingestion. Despite lower total ingested paracetamol doses and lower admission serum alanine aminotransferase concentrations, staggered overdose patients were more likely to be encephalopathic on admission, require renal replacement therapy or mechanical ventilation and had higher mortality rates compared with single time point overdoses (37.3% vs. 27.8%, P= 0.025), although this overdose pattern did not independently predict death. The King's College poor prognostic criteria had reduced sensitivity (77.6, 95% CI 70.8, 81.5) for this pattern of overdose. Of the 396/450 (88.0%) single time point overdoses in whom accurate timings could be obtained, 178 (44.9%) presented to medical services >24 h following overdose. Delayed presentation beyond 24 h post overdose was independently associated with death/liver transplantation (OR 2.25, 95% CI 1.23, 4.12, P= 0.009). Both delayed presentation and staggered overdose pattern are associated with adverse outcomes following paracetamol overdose. These patients are at increased risk of developing multi-organ failure and should be considered for early transfer to specialist liver centres. © 2011 The Authors. British Journal of Clinical Pharmacology © 2011 The British Pharmacological Society.

  3. Cellular uptake of magnetite nanoparticles enhanced by NdFeB magnets in staggered arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yi-Ching; Chang, Fan-Yu [Department of Physiology and Pharmacology & Healthy Aging Research Center, Guishan, Taoyuan City 33302, Taiwan, ROC (China); Tu, Shu-Ju [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Guishan, Taoyuan City 33302, Taiwan, ROC (China); Chen, Jyh-Ping [Department of Chemical and Materials Engineering, Chang Gung University, Guishan, Taoyuan City 33302, Taiwan, ROC (China); Ma, Yunn-Hwa, E-mail: yhma@mail.cgu.edu.tw [Department of Physiology and Pharmacology & Healthy Aging Research Center, Guishan, Taoyuan City 33302, Taiwan, ROC (China); Department of Neurology, Chang Gung Memorial Hospital, Guishan, Taoyuan City 33305, Taiwan, ROC (China)

    2017-04-01

    Magnetic force may greatly enhance uptake of magnetic nanoparticles (MNPs) by cultured cells; however, the effects of non-uniformity of magnetic field/ magnetic gradient on MNP internalization in culture has not been elucidated. Cellular uptake of polyacrylic acid coated-MNP by LN229 cells was measured with cylindrical NdFeB magnets arranged in a staggered pattern. The magnetic field generated by placing a magnet underneath (H-field) elicited a homogenous distribution of MNPs on the cells in culture; whereas the field without magnet underneath (L-field) resulted in MNP distribution along the edge of the wells. Cell-associated MNP (MNP{sub cell}) appeared to be magnetic field- and concentration-dependent. In H-field, MNP{sub cell} reached plateau within one hour of exposure to MNP with only one-min application of the magnetic force in the beginning of incubation; continuous presence of the magnet for 2 h did not further increase MNP{sub cell}, suggesting that magnetic force-induced uptake may be primarily contributed to enhanced MNP sedimentation. Although MNP distribution was much inhomogeneous in L-field, averaged MNP{sub cell} in the L-field may reach as high as 80% of that in H-field during 1–6 h incubation, suggesting high capacity of MNP internalization. In addition, no significant difference was observed in MNP{sub cell} analyzed by flow cytometry with the application of H-field of staggered plate vs. filled magnet plate. Therefore, biological variation may dominate MNP internalization even under relatively uniformed magnetic field; whereas non-uniformed magnetic field may serve as a model for tumor targeting with MNPs in vivo. - Graphical abstract: Averaged MNP uptake by glioma cells in the low and non-uniformed magnetic field reached as high as 80% of that in uniformed magnetic field, which is probably due to both heterogeneous distributions of MNPs in the non-uniformed magnetic field and high capacity of the MNP uptake by these cells. - Highlights:

  4. An effective method for smoothing the staggered dose distribution of multi-leaf collimator field edge

    International Nuclear Information System (INIS)

    Hwang, I.-M.; Lin, S.-Y.; Lee, M.-S.; Wang, C.-J.; Chuang, K.-S.; Ding, H.-J.

    2002-01-01

    Purpose: To smooth the staggered dose distribution that occurs in stepped leaves defined by a multi-leaf collimator (MLC). Materials and methods: The MLC Shaper program controlled the stepped leaves, which were shifted in a traveling range, the pattern of shift was from the position of out-bound to in-bound with a one-segment (cross-bound), three-segment, and five-segment shifts. Film was placed at a depth of 1.5 cm and irradiated with the same irradiation dose used for the cerrobend block experiment. Four field edges with the MLC defining at 15 deg., 30 deg., 45 deg., 60 deg. angels relative to the jaw edge were performed, respectively, in this study. For the field edge defined by the multi-segment technique, the amplitude of the isodose lines for 50% isodose line and both the 80% and 20% isodose lines were measured. The effective penumbra widths with 90-10% and 80-20% distances for different irradiations were determined at four field edges with the MLC defining at 15 deg., 30 deg., 45 deg., 60 deg. angels relative to the jaw edge. Results: Use of the five-segment technique for multi-leaf collimation at the 60 deg. angle field edge smoothes each isodose line into an effectively straight line, similar to the pattern achieved using a cerrobend block. The separation of these lines is also important. The 80-20% effective penumbra width with five-segment techniques (8.23 mm) at 60 deg. angle relative to the jaw edge is little wider (1.9 times) than the penumbra of cerrobend block field edge (4.23 mm). We also found that the 90-10% effective penumbra width with five-segment techniques (12.68 mm) at 60 deg. angle relative to the jaw edge is little wider (1.28 times) than the penumbra of cerrobend block field edge (9.89 mm). Conclusion: The multi-segment technique is effective in smoothing the MLC staggered field edge. The effective penumbra width with more segment techniques at larger degree angles relative to the field edge is little wider than the penumbra for a

  5. A Study of a Powder Coating Gun near Field: A Case of Staggered Concentric Jet Flow

    Directory of Open Access Journals (Sweden)

    Edward Grandmaison

    2013-11-01

    Full Text Available This paper examines, experimentally and numerically, an isothermal coaxial air jet, created by an innovative nozzle design for an air propane torch, used for the thermal deposition of polymers. This design includes staggering the origins of the central and annular jets and creating an annular air jet with an inward radial velocity component. The experimental work used a Pitot tube to measure axial velocity on the jet centerline and in the fully developed flow. The static gauge pressure in the near field was also measured and found to be positive, an unexpected result. The numerical work used Gambit and Fluent. An extensive grid sensitivity study was conducted and it was found that results from a relatively coarse mesh were substantially the same as results from a mesh with almost 11 times the number of control volumes. A thorough evaluation of all of the RANS models in Fluent 6.3.26 found that the flow fields they calculated showed at most partial agreement with the experimental results. The greatest difference between numerical and experimental results was the incorrect prediction by all RANS models of a recirculation zone in the near field on the jet axis. Experimental work showed it did not exist.

  6. Natural convection heat transfer for a staggered array of heated, horizontal cylinders within a rectangular enclosure

    Energy Technology Data Exchange (ETDEWEB)

    Triplett, C.E.

    1996-12-01

    This thesis presents the results of an experimental investigation of natural convection heat transfer in a staggered array of heated cylinders, oriented horizontally within a rectangular enclosure. The main purpose of this research was to extend the knowledge of heat transfer within enclosed bundles of spent nuclear fuel rods sealed within a shipping or storage container. This research extends Canaan`s investigation of an aligned array of heated cylinders that thermally simulated a boiling water reactor (BWR) spent fuel assembly sealed within a shipping or storage cask. The results are presented in terms of piecewise Nusselt-Rayleigh number correlations of the form Nu = C(Ra){sup n}, where C and n are constants. Correlations are presented both for individual rods within the array and for the array as a whole. The correlations are based only on the convective component of the heat transfer. The radiative component was calculated with a finite-element code that used measured surface temperatures, rod array geometry, and measured surface emissivities as inputs. The correlation results are compared to Canaan`s aligned array results and to other studies of natural convection in horizontal tube arrays.

  7. Natural convection heat transfer for a staggered array of heated, horizontal cylinders within a rectangular enclosure

    International Nuclear Information System (INIS)

    Triplett, C.E.

    1996-12-01

    This thesis presents the results of an experimental investigation of natural convection heat transfer in a staggered array of heated cylinders, oriented horizontally within a rectangular enclosure. The main purpose of this research was to extend the knowledge of heat transfer within enclosed bundles of spent nuclear fuel rods sealed within a shipping or storage container. This research extends Canaan's investigation of an aligned array of heated cylinders that thermally simulated a boiling water reactor (BWR) spent fuel assembly sealed within a shipping or storage cask. The results are presented in terms of piecewise Nusselt-Rayleigh number correlations of the form Nu = C(Ra) n , where C and n are constants. Correlations are presented both for individual rods within the array and for the array as a whole. The correlations are based only on the convective component of the heat transfer. The radiative component was calculated with a finite-element code that used measured surface temperatures, rod array geometry, and measured surface emissivities as inputs. The correlation results are compared to Canaan's aligned array results and to other studies of natural convection in horizontal tube arrays

  8. Development of Non-staggered, SMAC numerical scheme for a two-fluid model

    International Nuclear Information System (INIS)

    Yoon, H. Y.; Jeong, Jae Jun

    2007-06-01

    The SMAC(Simplified Marker And Cell) method, along with the SIMPLE, has long been used efficiently for the computational fluid dynamics. Usually, the majority of the applications are single phase compressible or incompressible fluids, and the numerical methods are to be modified to implement the following items for the analysis of two-phase flows. - Non-staggered grid for the analysis of a complex geometry - Application of the two-phase models - Coupling of the energy conservation equations - Two-phase flows with phase change. In this report, the SMAC Method is reviewed and extended to compressible two-phase flows with phase change. A pilot code CUPID-M is developed using the proposed numerical method. A set of verification calculations are carried out for th CUPID-M. At first, isothermal air-water flow is simulated to verify the numerical method against two-phase flow flow problems. Next, the two-phase flows with phase change are calculated using CUPID-M and the results are compared to that of CUPID-I, which is based on the coupled ICE method. The calculation time is shorter with CUPID-M than with CUPID-I, while the calculations are unstable with CUPID-M for the rapid phase change problems. Thus, CUPID-M and CUPID-I can be used as an user input considering the application problems

  9. An analytical solution for contact resistance of staggered organic field-effect transistors

    Science.gov (United States)

    Karimi-Alavijeh, Hamidreza; Katebi-Jahromi, Alireza

    2017-03-01

    We have developed analytical models for bias dependent contact resistance (RC) and output characteristics of staggered organic field-effect transistors (OFETS) based on a bulk resistance-approximated and mobility-modified current-crowding method. Numerical evaluations of RC and its resistive components show that the bias dependency of the bulk resistance is negligible. Consequently, the properties of the active layer interfaces determine RC and its characteristics. Effective parameters include a normally constant charge injection barrier at the organic-metal interface (Eb) and a gate induced surface carrier-concentration (PS0) at the organic-insulator boundary. The energy barrier pertains to the fabrication process, and its related resistance (rc) can be determined as the fitting parameter of the theoretical model. However, PS0 is strongly gate bias dependent and the results of the numerical model indicate that the resulting component (rch) is dominant and has a considerable effect on RC and its characteristics. More importantly, PS0 as the key parameter of the contact resistance is analytically expressible and by using a proposed mobility-modified current-crowding model, the contact resistance can be analytically formulated. Accordingly, the output characteristics of the OFETs in the triode region can be also analytically modeled using the developed relation of RC.

  10. Large odd-even staggering in the very light platinum isotopes from laser spectroscopy

    CERN Document Server

    Le Blanc, F; Cabaret, L A; Crawford, J E; Duong, H T; Genevey, J; Girod, M; Huber, G; Krieg, M; Lee, J K P; Lettry, Jacques; Lunney, M D; Obert, J; Oms, J; Peru, S; Putaux, J C; Roussière, B; Sauvage, J; Sebastian, V; Zemlyanoi, S G

    1998-01-01

    Laser spectroscopy measurements have been carried out on very neutron-deficient platinum isotopes with the COMPLIS experimental set-up on line with the ISOLDE-Booster facility. For the first time, Hg alpha -decay was exploited to extend the very light platinum chain. Using the 5d/sup 9/6s /sup 3/D/sub 3/ to 5d/sup 9/6p /sup 3/P /sub 2/ optical transition, hyperfine spectra of /sup 182,181,180,179,178/Pt and /sup 183/Pt/sup m/ were recorded for the first time. The variation of the mean square charge radius between these nuclei, the magnetic moments of the odd isotopes and the quadrupole moment of /sup 183/Pt/sup m/ were thus measured. A large deformation change between /sup 183/Pt/sup 9/ and /sup 183/Pt/sup m/, an odd-even staggering of the charge radius and a deformation drop from A=179 are clearly observed. All these results are discussed and compared with microscopic theoretical predictions using Hartree-Fock- Bogolyubov calculations using the Gogny force. (20 refs).

  11. The Effect of First-Step Techniques from the Staggered Stance in American Football

    DEFF Research Database (Denmark)

    Knudsen, Nikolas Sten; Andersen, Thomas Bull

    2017-01-01

    The purpose of this study was to evaluate 3 different starting techniques from the staggered stance with regards to sprint time, reaction time, linear impulse and power. 11 male amateur American football players volunteered to participate in a testing session consisting of twelve 5 m sprints, 4...... in each technique (normal (NORM), backwards false step (BFS) and forwards false step (FFS)) in random order. Sprint starts were performed on force plates to investigate ground reaction forces, reaction time and total sprint time. Analysis showed significant differences in sprint times, with NORM (1.......77±0.10 s) being faster than FFS (1.81±0.12 s) and BFS (2.01±0.13 s), and FFS being faster than BFS, although no differences were found in reaction time. In terms of mean force and power, NORM (331.1±39.2N, 542.2±72.3W) and FFS (320.8±43.2N, 550.9±81.4W) were significantly larger than BFS (256.9±36.2N, 443...

  12. Performance Analysis and Modeling of a Tubular Staggered-Tooth Transverse-Flux PM Linear Machine

    Directory of Open Access Journals (Sweden)

    Shaohong Zhu

    2016-03-01

    Full Text Available This paper investigates the performance analysis and mathematical modeling of a staggered-tooth transverse-flux permanent magnet linear synchronous machine (STTF-PMLSM, which is characterized by simple structure and low flux leakage. Firstly, the structure advantages and operation principle of the STTF-PMLSM are introduced, and a simplified one phase model is established to investigate the performance of the machine in order to save the computation time. Then, the electromagnetic characteristics, including no-load flux linkage, electromotive force (EMF, inductance, detent force and thrust force, are simulated and analyzed in detail. After that, the theoretical analysis of the detent force, thrust force, and power factor are carried out. And the theoretical analysis results are validated with 3-D finite-element method (FEM. Finally, an improved mathematical model of the machine based on d-q rotating coordinate system is proposed, in which inductance harmonics and coupling between d- and q-axis inductance is considered. The results from the proposed mathematical model are in accordance with the results from 3-D FEM, which proves the validity and effectiveness of the proposed mathematical model. This provides a powerful foundation for the control of the machine.

  13. Dave Eggers's a heartbreaking work of staggering genius: memoir as a "pain-relief device".

    Science.gov (United States)

    Miller, Elise

    2011-10-01

    Dave Eggers's memoir is an important addition to the tradition of autobiography in America, and offers significant contributions to our understanding of creativity, sublimation, and the psychology of the memoir-writing process. A Heartbreaking Work of Staggering Genius is really two books--an autobiographical narrative about unbearable suffering, and a book of psychoanalytic commentary on the challenges of writing a memoir about catastrophic loss and trauma. The main narrative suggests the psychological resilience it takes to contain unbearable suffering. The metanarrative renders transparent the mind of someone who is both remembering his losses and constantly reflecting upon the process of writing about them. Eggers's identification with authorship, rather than bereavement or traumatization, may have played an important role in containing his affect and his sense of self when the heartbreaking events were originally unfolding. But a price is paid when a son uses his art to construct a new identity as an author--unconscious conflicts, primitive affect, anxieties about failing, as well as guilt about succeeding--consequences often missed by readers. Heartbreaking is a palimpsest, a story about story-telling superimposed on tales of death and survival, but its messages will be missed unless all its parts are preserved when being read or studied.

  14. Exploration of the horizontally staggered light guides for high concentration CPV applications.

    Science.gov (United States)

    Selimoglu, Ozgur; Turan, Rasit

    2012-08-13

    The material and processing costs are still the major drawbacks of the c-Si based photovoltaic (PV) technology. The wafer cost comprises up to 35-40% of the total module cost. New approaches and system designs are needed in order to reduce the share of the wafer cost in photovoltaic energy systems. Here we explore the horizontally staggered light guide solar optics for use in Concentrated Photovoltaic (CPV) applications. This optical system comprises a lens array system coupled to a horizontal light guide which directs the incoming light beam to its edge. We have designed and simulated this system using a commercial ray tracing software (Zemax). The system is more compact, thinner and more robust compared to the conventional CPV systems. Concentration levels as high as 1000x can easily be reached when the system is properly designed. With such a high concentration level, a good acceptance angle of + -1 degree is still be conserved. The analysis of the system reveals that the total optical efficiency of the system could be as high as %94.4 without any anti-reflection (AR) coating. Optical losses can be reduced by just accommodating a single layer AR coating on the initial lens array leading to a %96.5 optical efficiency. Thermal behavior of high concentration linear concentrator is also discussed and compared with a conventional point focus CPV system.

  15. Chiral phase transition of three flavor QCD with nonzero magnetic field using standard staggered fermions

    Science.gov (United States)

    Tomiya, Akio; Ding, Heng-Tong; Mukherjee, Swagato; Schmidt, Christian; Wang, Xiao-Dan

    2018-03-01

    Lattice simulations for (2+1)-flavor QCD with external magnetic field demon-strated that the quark mass is one of the important parameters responsible for the (inverse) magnetic catalysis. We discuss the dependences of chiral condensates and susceptibilities, the Polyakov loop on the magnetic field and quark mass in three degenerate flavor QCD. The lattice simulations are performed using standard staggered fermions and the plaquette action with spatial sizes Nσ = 16 and 24 and a fixed temporal size Nτ = 4. The value of the quark masses are chosen such that the system undergoes a first order chiral phase transition and crossover with zero magnetic field. We find that in light mass regime, the quark chiral condensate undergoes magnetic catalysis in the whole temperature region and the phase transition tend to become stronger as the magnetic field increases. In crossover regime, deconfinement transition temperature is shifted by the magnetic field when quark mass ma is less than 0:4. The lattice cutoff effects are also discussed.

  16. Nuclear shape staggering in very neutron deficient Hg isotopes detected by laser spectroscopy

    International Nuclear Information System (INIS)

    Dabkiewicz, P.; Duke, C.; Fischer, H.; Kuehl, T.; Kluge, H.-J.

    1978-01-01

    The isotope shift in the lambda = 2537 A line of the even isotopes 206 Hg, 190 Hg, 188 Hg, 186 Hg, 184 Hg as well as of the I = 13/2 isomers of 191 Hg, 189 Hg, 187 Hg, 185 Hg has been measured by use of a tunable dye laser at the on-line masseparator ISOLDE at CERN. The resulting delta 2 > values follow the line, extrapolated from the chain 205 Hg- 187 Hg which is known to have spherical nuclear shape at the heavy end changing smoothly to slight oblate deformation for the lighter isotopes. Previous measurements of the I = 1/2 groundstates of 181 Hg. 183 Hg and 185 Hg revealed a sharp shape transition to strong deformation. Combined with the new results the following effects can be proved for the first time from the model-independent quantity delta 2 >: 1) the existence of odd even-shape staggering, 2) the coexistence of very different shapes in one and the same nucleus as manifested by the huge isomer shift in 185 Hg, 3) the absence of mixing of the different shapes. (author)

  17. Simulating dam-break over an erodible embankment using SWE-Exner model and semi-implicit staggered scheme

    Science.gov (United States)

    Ambara, M. D.; Gunawan, P. H.

    2018-03-01

    The impact of a dam-break wave on an erodible embankment with a steep slope has been studied recently using both experimental and numerical approaches. In this paper, the semi-implicit staggered scheme for approximating the shallow water-Exner model will be elaborated to describe the erodible sediment on a steep slope. This scheme is known as a robust scheme to approximate shallow water-Exner model. The results are shown in a good agreement with the experimental data. The comparisons of numerical results with data experiment using slopes Φ = 59.04 and Φ = 41.42 by coefficient of Grass formula Ag = 2 × 10‑5 and Ag = 10‑5 respectively are found the closest results to the experiment. This paper can be seen as the additional validation of semi-implicit staggered scheme in the paper of Gunawan, et al (2015).

  18. Tight-binding electrons on triangular and kagome lattices under staggered modulated magnetic fields: quantum Hall effects and Hofstadter butterflies

    Energy Technology Data Exchange (ETDEWEB)

    Li Juan; Wang Yifei; Gong Changde, E-mail: yfwang_nju@hotmail.com [Center for Statistical and Theoretical Condensed Matter Physics, and Department of Physics, Zhejiang Normal University, Jinhua 321004 (China)

    2011-04-20

    We consider the tight-binding models of electrons on a two-dimensional triangular lattice and kagome lattice under staggered modulated magnetic fields. Such fields have two components: a uniform-flux part with strength {phi}, and a staggered-flux part with strength {Delta}{phi}. Various properties of the Hall conductances and Hofstadter butterflies are studied. When {phi} is fixed, variation of {Delta}{phi} leads to the quantum Hall transitions and Chern numbers of Landau subbands being redistributed between neighboring pairs. The energy spectra with nonzero {Delta}{phi}s have similar fractal structures but quite different energy gaps compared with the original Hofstadter butterflies of {Delta}{phi} = 0. Moreover, the fan-like structure of Landau levels in the low magnetic field region is also modified appreciably by {Delta}{phi}.

  19. Hydrogen bonds and van der Waals forces as tools for the construction of a herringbone pattern in the crystal structure of hexane-1,6-diaminium hexane-1,6-diyl bis(hydrogen phosphonate

    Directory of Open Access Journals (Sweden)

    Guido J. Reiss

    2017-01-01

    Full Text Available The asymmetric unit of the title salt, [H3N(CH26NH3][(HOO2P(CH26PO2(OH], consists of one half of a hexane-1,6-diaminium dication and one half of a hexane-1,6-diyl bis(hydrogen phosphonate dianion. Both are located around different centres of inversion (Wyckoff sites: 2a and 2d of the space group P21/c. The shape of the hexane-1,6-diaminium cation is best described as a double hook. Both aminium groups as well as the two attached CH2 groups are turned out from the plane of the central four C atoms. In contrast, all six C atoms of the dianion are almost in a plane. The hydrogen phosphonate (–PO3H groups of the anions and the aminium groups of the cations form two-dimensional O—H... and O—H...N hydrogen-bonded networks parallel to the ac plane, built up from ten-membered and twelve-membered ring motifs with graph-set descriptors R33(10 and R54(12, respectively. These networks are linked by the alkylene chains of the anions and cations. The resulting three-dimensional network shows a herringbone pattern, which resembles the parent structures 1,6-diaminohexane and hexane-1,6-diphosphonic acid.

  20. Postprandial effects of consuming a staggered meal on gut peptide and glycemic responses in obese women and men.

    Science.gov (United States)

    Griffith, Lisa; Haddad, Ella H; Tonstad, Serena

    2016-01-01

    Eating slowly by staggering a meal may reduce energy intake. Our aim was to examine the effect of eating a portion of beans 15min before the rest of the meal, on gastrointestinal (GI) peptides, glucose and insulin concentrations and subsequent energy intake in obese adults. This was a randomised crossover design study with 28 obese subjects. Participants consumed a standardised breakfast on test days followed by test meals: (1) control meal containing 86g (0.5 cup) of beans, and (2) staggered meal in which 86g (0.5 cup) of beans were consumed 15min before the rest of the meal. Blood obtained prior to and at 30, 60, and 120min following the meals was analysed for acylated ghrelin, unacylated ghrelin, glucagon-like peptide-1 (GLP-1), peptide YY, oxyntomodulin, glucose and insulin. Feelings of hunger and satiety were assessed using analog visual scales. Energy intake following the test meal was obtained by computer assisted dietary recalls. Mixed model statistical analysis of data showed time effects for unacylated ghrelin, GLP-1, glucose, insulin, hunger and fullness, however, meal effects were not shown for any of the parameters. GLP-1 area under the curve from baseline to 120min (AUC0-120) decreased by 19% (P=0.024) and that of glucose increased by 7% (P=0.046) following the staggered compared to the control bean meal. Energy intake subsequent to the test meals did not differ between treatments. In conclusion, lengthening meal times by staggering eating did not benefit hormonal, metabolic or appetite control in obese individuals. Copyright © 2015 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

  1. JIGSAW-GEO (1.0): locally orthogonal staggered unstructured grid generation for general circulation modelling on the sphere

    Science.gov (United States)

    Engwirda, Darren

    2017-06-01

    An algorithm for the generation of non-uniform, locally orthogonal staggered unstructured spheroidal grids is described. This technique is designed to generate very high-quality staggered Voronoi-Delaunay meshes appropriate for general circulation modelling on the sphere, including applications to atmospheric simulation, ocean-modelling and numerical weather prediction. Using a recently developed Frontal-Delaunay refinement technique, a method for the construction of high-quality unstructured spheroidal Delaunay triangulations is introduced. A locally orthogonal polygonal grid, derived from the associated Voronoi diagram, is computed as the staggered dual. It is shown that use of the Frontal-Delaunay refinement technique allows for the generation of very high-quality unstructured triangulations, satisfying a priori bounds on element size and shape. Grid quality is further improved through the application of hill-climbing-type optimisation techniques. Overall, the algorithm is shown to produce grids with very high element quality and smooth grading characteristics, while imposing relatively low computational expense. A selection of uniform and non-uniform spheroidal grids appropriate for high-resolution, multi-scale general circulation modelling are presented. These grids are shown to satisfy the geometric constraints associated with contemporary unstructured C-grid-type finite-volume models, including the Model for Prediction Across Scales (MPAS-O). The use of user-defined mesh-spacing functions to generate smoothly graded, non-uniform grids for multi-resolution-type studies is discussed in detail.

  2. Development of multi dimensional analysis code for containment safety and performance based on staggered semi-implicit finite volume method

    International Nuclear Information System (INIS)

    Hong, Soon Joon; Hwang, Su Hyun; Han, Tae Young; Lee, Byung Chul; Byun, Choong Sup

    2009-01-01

    A solver of 3-dimensional thermal hydraulic analysis code for a large building having multi rooms such as reactor containment was developed based on 2-phase and 3-field conservation equations. Three fields mean gas, continuous liquid, and dispersed drop. Gas field includes steam, air and hydrogen. Gas motion equation and state equation also considered. Homogeneous and equilibrium conditions were assumed for gas motion equation. Source terms related with phase change were explicitly expressed for the implicit scheme. Resultantly, total 17 independent equations were setup, and total 17 primitive unknowns were identified. Numerical scheme followed the FVM (Finite Volume Method) based on staggered orthogonal structured grid and semi-implicit method. Staggered grid system produces staggered numerical cells of a scalar cell and a vector cell. The porosity method was adopted for easy handling the complex structures inside a computational cell. Such porosity method has been known to be very effective in reducing mesh numbers and acquiring accurate results in spite of fewer meshes. In the actual programming C++ language of OOP (Object Oriented Programming) was used. The code developed by OOP has the features such as the information hiding, encapsulation, modularity and inheritance. These can offer code developers the more explicit and clearer development method. Classes were designed. Cell and Face, and Volume and Component are the bases of the largest Class, System. Class Solver was designed in order to run the solver. Sample runs showed physically reasonable results. The foundation of code was setup through a series of numerical development. (author)

  3. Entropy Stable Staggered Grid Discontinuous Spectral Collocation Methods of any Order for the Compressible Navier--Stokes Equations

    KAUST Repository

    Parsani, Matteo

    2016-10-04

    Staggered grid, entropy stable discontinuous spectral collocation operators of any order are developed for the compressible Euler and Navier--Stokes equations on unstructured hexahedral elements. This generalization of previous entropy stable spectral collocation work [M. H. Carpenter, T. C. Fisher, E. J. Nielsen, and S. H. Frankel, SIAM J. Sci. Comput., 36 (2014), pp. B835--B867, M. Parsani, M. H. Carpenter, and E. J. Nielsen, J. Comput. Phys., 292 (2015), pp. 88--113], extends the applicable set of points from tensor product, Legendre--Gauss--Lobatto (LGL), to a combination of tensor product Legendre--Gauss (LG) and LGL points. The new semidiscrete operators discretely conserve mass, momentum, energy, and satisfy a mathematical entropy inequality for the compressible Navier--Stokes equations in three spatial dimensions. They are valid for smooth as well as discontinuous flows. The staggered LG and conventional LGL point formulations are compared on several challenging test problems. The staggered LG operators are significantly more accurate, although more costly from a theoretical point of view. The LG and LGL operators exhibit similar robustness, as is demonstrated using test problems known to be problematic for operators that lack a nonlinear stability proof for the compressible Navier--Stokes equations (e.g., discontinuous Galerkin, spectral difference, or flux reconstruction operators).

  4. Research of heat transfer of staggered horizontal bundles of finned tubes at free air convection

    Science.gov (United States)

    Novozhilova, A. V.; Maryna, Z. G.; Samorodov, A. V.; Lvov, E. A.

    2017-11-01

    The study of free-convective processes is important because of the cooling problem in many machines and systems, where other ways of cooling are impossible or impractical. Natural convective processes are common in the steam turbine air condensers of electric power plants located within the city limits, in dry cooling towers of circulating water systems, in condensers cooled by air and water, in radiators cooling oil of power electric transformers, in emergency cooling systems of nuclear reactors, in solar power, as well as in air-cooling of power semiconductor energy converters. All this makes actual the synthesis of the results of theoretical and experimental research of free convection for heat exchangers with finned tube bundles. The results of the study of free-convection heat transfer for two-, three- and four-row staggered horizontal bundles of industrial bimetallic finned tubes with finning factor of 16.8 and equilateral tubes arrangement are presented. Cross and diagonal steps in the bundles are the same: 58; 61; 64; 70; 76; 86; 100 mm, which corresponds to the relative steps: 1.042; 1.096; 1.152; 1.258; 1.366; 1.545; 1.797. These steps are standardized for air coolers. An equation for calculating the free-convection heat transfer, taking into account the influence of geometrical parameters in the range of Rayleigh number from 30,000 to 350,000 with an average deviation of ± 4.8%, has been obtained. The relationship presented in the article allows designing a wide range of air coolers for various applications, working in the free convection modes.

  5. The power spectral density of digital modulations transmitted over nonlinear channels

    Science.gov (United States)

    Divsalar, D.; Simon, M. K.

    1982-01-01

    This paper examines by analytical methods the power spectral densities of digital modulations (in particular, staggered and unstaggered quadrature modulations) passed through band-limited nonlinear channels. Previously observed (by computer simulation or hardware measurement) behavior of such spectra with regard to the suppression or restoration of its sidelobes after passing through the nonlinearity is verified analytically. Several examples corresponding to specific quadrature modulations and filter-nonlinearity combinations are presented as illustrations of the general results.

  6. Hastatic order in the two-channel Kondo-Heisenberg model

    Science.gov (United States)

    Zhang, Guanghua; Flint, Rebecca

    Understanding Kondo physics in materials with non-Kramers doublets requires understanding the two channel Kondo effect, as valence fluctuations are from a non-Kramers doublet ground state to an excited Kramers doublet. Here, the development of a heavy Fermi liquid requires a channel symmetry breaking hybridization. This order, which breaks both single and double time-reversal symmetry was recently introduced as hastatic order. Here we employ an SU(N) fermionic mean-field treatment of the two-channel Kondo-Heisenberg model on a square lattice to explore properties of hastatic order and particularly the competition between the hastatic order and magnetism, as embodied by a spin liquid phase in our model. For simplicity, only a momentum independent hybrization between the non-Kramers f2 states and conduction electrons is considered. Upon varying the RKKY coupling and conduction electron density, we find both uniform and staggered [ Q = (π , π) ] hastatic order, in addition to the spin liquid phase, with metal-insulator transitions, including Lifshitz transitions inside the staggered phase. As the band degeneracy of the conduction electron bands is broken, the uniform hastatic order is partially suppressed compared to the staggered phase.

  7. Ion channeling

    International Nuclear Information System (INIS)

    Erramli, H.; Blondiaux, G.

    1994-01-01

    Channeling phenomenon was predicted, many years ago, by stark. The first channeling experiments were performed in 1963 by Davies and his coworkers. Parallely Robinson and Oen have investigated this process by simulating trajectories of ions in monocrystals. This technique has been combined with many methods like Rutherford Backscattering Spectrometry (R.B.S.), Particles Induced X-rays Emission (P.I.X.E) and online Nuclear Reaction (N.R.A.) to localize trace elements in the crystal or to determine crystalline quality. To use channeling for material characterization we need data about the stopping power of the incident particle in the channeled direction. The ratios of channeled to random stopping powers of silicon for irradiation in the direction have been investigated and compared to the available theoretical results. We describe few applications of ion channeling in the field of materials characterization. Special attention is given to ion channeling combined with Charged Particle Activation Analysis (C.P.A.A.) for studying the behaviour of oxygen atoms in Czochralski silicon lattices under the influence of internal gettering and in different gaseous atmospheres. Association between ion channeling and C.P.A.A was also utilised for studying the influence of the growing conditions on concentration and position of carbon atoms at trace levels in the MOVPE Ga sub (1-x) Al sub x lattice. 6 figs., 1 tab., 32 refs. (author)

  8. Heat exchange and pressure drop of herring-bone fin surfaces. Experimental cell results at constant wall temperature; Echange de chaleur et perte de charge de surfaces a ailettes en chevrons. Resultats experimentaux en cellule a temperature de paroi constante

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1968-07-01

    The increase in the specific power of nuclear reactors of the gas-graphite type has necessitated the use of high performance exchange surfaces for canning the fuel (natural uranium). For this, experiments were carried out on cans fitted with herring-bone fins, at constant wall temperature; a flow of water at 100 deg. C passes inside the can which is cooled externally by a flow of CO{sub 2} at 15 bars pressure. This experimental set-up makes it possible to compare the aero-thermal performances of the different cans with an accuracy of 5 per cent. This report presents the results obtained in the form of a friction coefficient f{sub 0} and mean Margoulis number m{sub 0} as a function of the Reynolds number Re{sub 0}, this latter varying from 3 x 10{sup 5} to 9 x 10{sup 5}. (authors) [French] L'augmentation de la puissance specifique des reacteurs nucleaires de la filiere graphite-gaz a necessite l'utilisation de surfaces d'echange a hautes performances pour gainer le combustible (uranium naturel). Dans cette optique, des gaines munies d'ailettes disposees en chevron ont ete experimentees a temperature de paroi constante: un courant d'eau a 100 deg. C circule a l'interieur de la gaine qui est refroidie exterieurement par un ecoulement de CO{sub 2} sous une pression de 15 bars. Cette methode experimentale permet de situer les performances aerothermiques des gaines les unes par rapport aux autres a 5 pour cent pres. Ce rapport presente les resultats obtenus sous la forme d'un coefficient de frottement f{sub 0} et d'un nombre de Margoulis moyen m{sub 0} en fonction du nombre de Reynolds Re{sub 0}, ce dernier pouvant varier de 3. 10{sup 5} a 9. 10{sup 5}. (auteurs)

  9. 3D Staggered-Grid Finite-Difference Simulation of Acoustic Waves in Turbulent Moving Media

    Science.gov (United States)

    Symons, N. P.; Aldridge, D. F.; Marlin, D.; Wilson, D. K.; Sullivan, P.; Ostashev, V.

    2003-12-01

    Acoustic wave propagation in a three-dimensional heterogeneous moving atmosphere is accurately simulated with a numerical algorithm recently developed under the DOD Common High Performance Computing Software Support Initiative (CHSSI). Sound waves within such a dynamic environment are mathematically described by a set of four, coupled, first-order partial differential equations governing small-amplitude fluctuations in pressure and particle velocity. The system is rigorously derived from fundamental principles of continuum mechanics, ideal-fluid constitutive relations, and reasonable assumptions that the ambient atmospheric motion is adiabatic and divergence-free. An explicit, time-domain, finite-difference (FD) numerical scheme is used to solve the system for both pressure and particle velocity wavefields. The atmosphere is characterized by 3D gridded models of sound speed, mass density, and the three components of the wind velocity vector. Dependent variables are stored on staggered spatial and temporal grids, and centered FD operators possess 2nd-order and 4th-order space/time accuracy. Accurate sound wave simulation is achieved provided grid intervals are chosen appropriately. The gridding must be fine enough to reduce numerical dispersion artifacts to an acceptable level and maintain stability. The algorithm is designed to execute on parallel computational platforms by utilizing a spatial domain-decomposition strategy. Currently, the algorithm has been validated on four different computational platforms, and parallel scalability of approximately 85% has been demonstrated. Comparisons with analytic solutions for uniform and vertically stratified wind models indicate that the FD algorithm generates accurate results with either a vanishing pressure or vanishing vertical-particle velocity boundary condition. Simulations are performed using a kinematic turbulence wind profile developed with the quasi-wavelet method. In addition, preliminary results are presented

  10. Dual-mixed finite elements for the three-field Stokes model as a finite volume method on staggered grids

    KAUST Repository

    Kou, Jisheng

    2017-06-09

    In this paper, a new three-field weak formulation for Stokes problems is developed, and from this, a dual-mixed finite element method is proposed on a rectangular mesh. In the proposed mixed methods, the components of stress tensor are approximated by piecewise constant functions or Q1 functions, while the velocity and pressure are discretized by the lowest-order Raviart-Thomas element and the piecewise constant functions, respectively. Using quadrature rules, we demonstrate that this scheme can be reduced into a finite volume method on staggered grid, which is extensively used in computational fluid mechanics and engineering.

  11. Heat transfer of a staggered fining flat-oval tube banks in cross flow at the small Reynolds number

    Directory of Open Access Journals (Sweden)

    Максим Михайлович Вознюк

    2015-05-01

    Full Text Available Experimental investigations of heat transfer of staggered bundles of flat-oval tubes with incomplete transversal finning in the range of Reynolds numbers 500 < <20000 are performed. New calculation correlations for determining of heat transfer coefficients for 1<3000 are suggested, the impact of basic geometric and regime parameters on intensity of external heat transfer are determined. The received calculation depending is possible to use in developing of heat transfer surfaces for “dry” cooling towers and air cooling apparatuses

  12. Effects of Front-Loading and Stagger Angle on Endwall Losses of High Lift Low Pressure Turbine Vanes

    Science.gov (United States)

    2012-09-01

    length scale at z/H = 0.20 ………….… 131 Fig. E.1 Traverse arrangement to enable 3D movement inside the wind tunnel …..… 132 Fig. E.2 Diagram of in...2 ] USAF = United States Air Force 2D = two-dimensional 3D = three-dimensional 1 EFFECTS OF FRONT-LOADING AND STAGGER ANGLE ON ENDWALL...within the wakes. I used Druck LPM 5481 pressure transducers, calibrated using a Ruska 7250LP laboratory standard (the reported accuracy is within

  13. Three-dimensional viscoelastic time-domain finite-difference seismic modelling using the staggered Adams-Bashforth time integrator

    Science.gov (United States)

    Bohlen, Thomas; Wittkamp, Florian

    2016-03-01

    We analyse the performance of a higher order accurate staggered viscoelastic time-domain finite-difference method, in which the staggered Adams-Bashforth (ABS) third-order and fourth-order accurate time integrators are used for temporal discretization. ABS is a multistep method that uses previously calculated wavefields to increase the order of accuracy in time. The analysis shows that the numerical dispersion is much lower than that of the widely used second-order leapfrog method. Numerical dissipation is introduced by the ABS method which is significantly smaller for fourth-order than third-order accuracy. In 1-D and 3-D simulation experiments, we verify the convincing improvements of simulation accuracy of the fourth-order ABS method. In a realistic elastic 3-D scenario, the computing time reduces by a factor of approximately 2.4, whereas the memory requirements increase by approximately a factor of 2.2. The ABS method thus provides an alternative strategy to increase the simulation accuracy in time by investing computer memory instead of computing time.

  14. Risk-based decision making for staggered bioterrorist attacks : resource allocation and risk reduction in "reload" scenarios.

    Energy Technology Data Exchange (ETDEWEB)

    Lemaster, Michelle Nicole; Gay, David M. (Sandia National Laboratories, Albuquerque, NM); Ehlen, Mark Andrew (Sandia National Laboratories, Albuquerque, NM); Boggs, Paul T.; Ray, Jaideep

    2009-10-01

    Staggered bioterrorist attacks with aerosolized pathogens on population centers present a formidable challenge to resource allocation and response planning. The response and planning will commence immediately after the detection of the first attack and with no or little information of the second attack. In this report, we outline a method by which resource allocation may be performed. It involves probabilistic reconstruction of the bioterrorist attack from partial observations of the outbreak, followed by an optimization-under-uncertainty approach to perform resource allocations. We consider both single-site and time-staggered multi-site attacks (i.e., a reload scenario) under conditions when resources (personnel and equipment which are difficult to gather and transport) are insufficient. Both communicable (plague) and non-communicable diseases (anthrax) are addressed, and we also consider cases when the data, the time-series of people reporting with symptoms, are confounded with a reporting delay. We demonstrate how our approach develops allocations profiles that have the potential to reduce the probability of an extremely adverse outcome in exchange for a more certain, but less adverse outcome. We explore the effect of placing limits on daily allocations. Further, since our method is data-driven, the resource allocation progressively improves as more data becomes available.

  15. SBP-SAT finite difference discretization of acoustic wave equations on staggered block-wise uniform grids

    KAUST Repository

    Gao, Longfei

    2018-02-16

    We consider the numerical simulation of the acoustic wave equations arising from seismic applications, for which staggered grid finite difference methods are popular choices due to their simplicity and efficiency. We relax the uniform grid restriction on finite difference methods and allow the grids to be block-wise uniform with nonconforming interfaces. In doing so, variations in the wave speeds of the subterranean media can be accounted for more efficiently. Staggered grid finite difference operators satisfying the summation-by-parts (SBP) property are devised to approximate the spatial derivatives appearing in the acoustic wave equation. These operators are applied within each block independently. The coupling between blocks is achieved through simultaneous approximation terms (SATs), which impose the interface condition weakly, i.e., by penalty. Ratio of the grid spacing of neighboring blocks is allowed to be rational number, for which specially designed interpolation formulas are presented. These interpolation formulas constitute key pieces of the simultaneous approximation terms. The overall discretization is shown to be energy-conserving and examined on test cases of both theoretical and practical interests, delivering accurate and stable simulation results.

  16. An experimental study on the effect of wind load around tall towers of square and hexagonal shapes in staggered form

    Science.gov (United States)

    Anwar, Proma; Islam, Md. Quamrul; Ali, Mohammad

    2017-06-01

    In this research work an experiment is conducted to observe the effect of wind load around square and hexagonal shaped cylinders in staggered form. The experiment is performed in an open circuit wind tunnel at a Reynolds number of 4.23×104 based on the face width of the cylinder across the flow direction. The flow velocity has been kept uniform at 14.3 m/s throughout the experiment. The test is conducted for single cylinders first and then in staggered form. The cylinders are rotated to create different angles of attack and the angles are chosen at a definite interval. The static pressure readings are taken at different locations of the cylinder by inclined multi-manometers. From the surface static pressure readings pressure coefficients, drag coefficients and lift coefficients are calculated using numerical integration method. These results will surely help engineers to design buildings more stable against wind load. All the results are expressed in non-dimensional form, so that they can be applied for prototype structures.

  17. MARKETING CHANNELS

    Directory of Open Access Journals (Sweden)

    Ljiljana Stošić Mihajlović

    2014-07-01

    Full Text Available Marketing channel is a set of entities and institutions, completion of distribution and marketing activities, attend the efficient and effective networking of producers and consumers. Marketing channels include the total flows of goods, money and information taking place between the institutions in the system of marketing, establishing a connection between them. The functions of the exchange, the physical supply and service activities, inherent in the system of marketing and trade. They represent paths which products and services are moving after the production, which will ultimately end up buying and eating by the user.

  18. Isospin transport phenomena and odd-even staggering in 84Kr+112,124Sn collisions at 35 AMeV

    Directory of Open Access Journals (Sweden)

    Piantelli S.

    2015-01-01

    Full Text Available Experimental results concerning isospin transport phenomena and odd-even staggering in Z and N distributions are presented. Data refer to 84Kr+112,124Sn collisions at 35AMeV and they were collected with a high resolution FAZIA telescope, able to isotopically resolve ions up to Z ∼ 20. Evidences of isospin diffusion and drift obtained from the /Z behaviour of the detected fragments are discussed. The odd-even staggering both in Z and N is compared with experimental data available in literature, finding that it shows a common trend in different reaction types.

  19. Isospin transport phenomena and odd-even staggering in 84Kr+112,124Sn collisions at 35 AMeV

    Science.gov (United States)

    Piantelli, S.; Casini, G.; Maurenzig, P. R.; Olmi, A.; Barlini, S.; Bini, M.; Carboni, S.; Pasquali, G.; Poggi, G.; Stefanini, A. A.; Valdré, S.; Bougault, R.; Bonnet, E.; Borderie, B.; Chbihi, A.; Frankland, J. D.; Gruyer, D.; Lopez, O.; Le Neindre, N.; Parlog, M.; Rivet, M.-F.; Vient, E.; Rosato, E.; Spadaccini, G.; Vigilante, M.; Bruno, M.; Marchi, T.; Morelli, L.; Cinausero, M.; Degerlier, M.; Gramegna, F.; Kozik, T.; Twarog, T.; Alba, R.; Maiolino, C.; Santonocito, D.

    2015-04-01

    Experimental results concerning isospin transport phenomena and odd-even staggering in Z and N distributions are presented. Data refer to 84Kr+112,124Sn collisions at 35AMeV and they were collected with a high resolution FAZIA telescope, able to isotopically resolve ions up to Z ˜ 20. Evidences of isospin diffusion and drift obtained from the /Z behaviour of the detected fragments are discussed. The odd-even staggering both in Z and N is compared with experimental data available in literature, finding that it shows a common trend in different reaction types.

  20. Staggered-grid finite-difference acoustic modeling with the Time-Domain Atmospheric Acoustic Propagation Suite (TDAAPS).

    Energy Technology Data Exchange (ETDEWEB)

    Aldridge, David Franklin; Collier, Sandra L. (U.S. Army Research Laboratory); Marlin, David H. (U.S. Army Research Laboratory); Ostashev, Vladimir E. (NOAA/Environmental Technology Laboratory); Symons, Neill Phillip; Wilson, D. Keith (U.S. Army Cold Regions Research Engineering Lab.)

    2005-05-01

    This document is intended to serve as a users guide for the time-domain atmospheric acoustic propagation suite (TDAAPS) program developed as part of the Department of Defense High-Performance Modernization Office (HPCMP) Common High-Performance Computing Scalable Software Initiative (CHSSI). TDAAPS performs staggered-grid finite-difference modeling of the acoustic velocity-pressure system with the incorporation of spatially inhomogeneous winds. Wherever practical the control structure of the codes are written in C++ using an object oriented design. Sections of code where a large number of calculations are required are written in C or F77 in order to enable better compiler optimization of these sections. The TDAAPS program conforms to a UNIX style calling interface. Most of the actions of the codes are controlled by adding flags to the invoking command line. This document presents a large number of examples and provides new users with the necessary background to perform acoustic modeling with TDAAPS.

  1. Channel Power in Multi-Channel Environments

    NARCIS (Netherlands)

    M.G. Dekimpe (Marnik); B. Skiera (Bernd)

    2004-01-01

    textabstractIn the literature, little attention has been paid to instances where companies add an Internet channel to their direct channel portfolio. However, actively managing multiple sales channels requires knowing the customers’ channel preferences and the resulting channel power. Two key

  2. Investigating the iatrogenic effects of repeated suicidal ideation screening on suicidal and depression symptoms: A staggered sequential study.

    Science.gov (United States)

    Hom, Melanie A; Stanley, Ian H; Rogers, Megan L; Gallyer, Austin J; Dougherty, Sean P; Davis, Lisa; Joiner, Thomas E

    2018-02-21

    Research suggests that screening for suicidality does not have iatrogenic effects; however, less is known regarding the impact of repeatedly screening for suicidal ideation among individuals with varying levels of exposure to these screenings. This staggered sequential study evaluated whether suicidal ideation severity increases with repeated screening for suicidal ideation and depression symptoms. Undergraduates (N = 207) were recruited at one of four time points (baseline [n = 37], 1 month later [n = 61], 4 months later [n = 55], and 12 months later [n = 54]) to complete the self-report Beck Depression Inventory (BDI). Participants completed the BDI at the time point at which they were recruited and all subsequent study time points. Non-parametric tests were employed to compare suicidal ideation severity (BDI Item 9) and depression symptom severity (BDI total score): (1) within each group across time points and (2) within each time point across groups. Suicidal ideation severity did not significantly differ within any group across time points, and for two groups, depression symptom severity decreased over time. For analyses between groups, suicidal ideation and depression symptom scores were, at times, significantly lower during subsequent BDI completion time points. This study utilized a relatively small sample size and participants of low clinical severity. Findings align with prior research indicating that suicidality screening is not iatrogenic. This study also expanded upon previous studies by leveraging a staggered sequential design to compare suicidal ideation and depression symptom severity among individuals with varying exposure to suicidal ideation screenings. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Starburst Channels

    Science.gov (United States)

    2007-01-01

    [figure removed for brevity, see original site] Figure 1 Translucent carbon dioxide ice covers the polar regions of Mars seasonally. It is warmed and sublimates (evaporates) from below, and escaping gas carves a numerous channel morphologies. In this example (figure 1) the channels form a 'starburst' pattern, radiating out into feathery extensions. The center of the pattern is being buried with dust and new darker dust fans ring the outer edges. This may be an example of an expanding morphology, where new channels are formed as the older ones fill and are no longer efficiently channeling the subliming gas out. Observation Geometry Image PSP_003443_0980 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 21-Apr-2007. The complete image is centered at -81.8 degrees latitude, 76.2 degrees East longitude. The range to the target site was 247.1 km (154.4 miles). At this distance the image scale is 24.7 cm/pixel (with 1 x 1 binning) so objects 74 cm across are resolved. The image shown here has been map-projected to 25 cm/pixel. The image was taken at a local Mars time of 04:52 PM and the scene is illuminated from the west with a solar incidence angle of 71 degrees, thus the sun was about 19 degrees above the horizon. At a solar longitude of 223.4 degrees, the season on Mars is Northern Autumn.

  4. Towards the development of a fully coupled arterial-venous 1D model: suitability of using a 1D finite volume method with staggered spatial discretization

    CSIR Research Space (South Africa)

    Bogaers, Alfred EJ

    2012-07-01

    Full Text Available In this paper we outline the development of a 1D finite volume model to solve for blood flow through the arterial system. The model is based on a staggered spatial discretization which leads to a stable solution scheme. This scheme can accurately...

  5. 49 CFR Figure 1 to Subpart B of... - Example of Location and Staggering of Emergency Window Exits-§ 238.113

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Example of Location and Staggering of Emergency Window Exits-§ 238.113 1 Figure 1 to Subpart B of Part 238 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT...

  6. 49 CFR Figure 2 to Subpart B of... - Example of a Multi-Level Car Complying with Window Location and Staggering Requirements-§§ 238...

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Example of a Multi-Level Car Complying with Window Location and Staggering Requirements-§§ 238.113 and 238.114 2 Figure 2 to Subpart B of Part 238 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...

  7. 29 CFR Appendix H to Subpart R of... - Double Connections: Illustration of a Clipped End Connection and a Staggered Connection: Non...

    Science.gov (United States)

    2010-07-01

    ... Connection and a Staggered Connection: Non-Mandatory Guidelines for Complying With § 1926.756(c)(1) H Appendix H to Subpart R of Part 1926 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY... CONSTRUCTION Steel Erection Pt. 1926, Subpt. R, App. H Appendix H to Subpart R of Part 1926—Double Connections...

  8. The Finite-Surface Method for incompressible flow: a step beyond staggered grid

    Science.gov (United States)

    Hokpunna, Arpiruk; Misaka, Takashi; Obayashi, Shigeru

    2017-11-01

    We present a newly developed higher-order finite surface method for the incompressible Navier-Stokes equations (NSE). This method defines the velocities as a surface-averaged value on the surfaces of the pressure cells. Consequently, the mass conservation on the pressure cells becomes an exact equation. The only things left to approximate is the momentum equation and the pressure at the new time step. At certain conditions, the exact mass conservation enables the explicit n-th order accurate NSE solver to be used with the pressure treatment that is two or four order less accurate without loosing the apparent convergence rate. This feature was not possible with finite volume of finite difference methods. We use Fourier analysis with a model spectrum to determine the condition and found that the range covers standard boundary layer flows. The formal convergence and the performance of the proposed scheme is compared with a sixth-order finite volume method. Finally, the accuracy and performance of the method is evaluated in turbulent channel flows. This work is partially funded by a research colloaboration from IFS, Tohoku university and ASEAN+3 funding scheme from CMUIC, Chiang Mai University.

  9. Motion of small cross-channel clusters on W(2 1 1) surface: A density functional theory study

    Science.gov (United States)

    Jurczyszyn, L.; Antczak, G.

    2014-04-01

    The adsorption and diffusion of cross-channel ad-dimers and ad-trimers was investigated using ab-initio DFT calculations. In contrast to in-channel dimers, the motion of cross-channel dimers proceeds one ad-atom at the time with an activation energy comparable to observed for quasi-isolated ad-atoms. The separation of ad-atoms by the surface channel wall lowers, but not eliminates, ad-atoms interactions. Pair interactions show long-range oscillatory behavior with an electronic origin. The short range interactions are modified by creation of straight and staggered direct bonds. Motion of ad-trimers proceeds in the same fashion as for cross-channel ad-dimers.

  10. Statin prescribing for people with severe mental illnesses: a staggered cohort study of 'real-world' impacts.

    Science.gov (United States)

    Blackburn, R; Osborn, D; Walters, K; Falcaro, M; Nazareth, I; Petersen, I

    2017-03-07

    To estimate the 'real-world effectiveness of statins for primary prevention of cardiovascular disease (CVD) and for lipid modification in people with severe mental illnesses (SMI), including schizophrenia and bipolar disorder. Series of staggered cohorts. We estimated the effect of statin prescribing on CVD outcomes using a multivariable Poisson regression model or linear regression for cholesterol outcomes. 587 general practice (GP) surgeries across the UK reporting data to The Health Improvement Network. All permanently registered GP patients aged 40-84 years between 2002 and 2012 who had a diagnosis of SMI. Exclusion criteria were pre-existing CVD, statin-contraindicating conditions or a statin prescription within the 24 months prior to the study start. One or more statin prescriptions during a 24-month 'baseline' period (vs no statin prescription during the same period). The primary outcome was combined first myocardial infarction and stroke. All-cause mortality and total cholesterol concentration were secondary outcomes. We identified 2944 statin users and 42 886 statin non-users across the staggered cohorts. Statin prescribing was not associated with significant reduction in CVD events (incident rate ratio 0.89; 95% CI 0.68 to 1.15) or all-cause mortality (0.89; 95% CI 0.78 to 1.02). Statin prescribing was, however, associated with statistically significant reductions in total cholesterol of 1.2 mmol/L (95% CI 1.1 to 1.3) for up to 2 years after adjusting for differences in baseline characteristics. On average, total cholesterol decreased from 6.3 to 4.6 in statin users and 5.4 to 5.3 mmol/L in non-users. We found that statin prescribing to people with SMI in UK primary care was effective for lipid modification but not CVD events. The latter finding may reflect insufficient power to detect a smaller effect size than that observed in randomised controlled trials of statins in people without SMI. Published by the BMJ Publishing Group Limited. For

  11. [Study on the white channel system carved on the wooden acupoint figurine of Laoguanshan: comments on lacquer-coating acupoint figure].

    Science.gov (United States)

    Liu, Chengzhong

    2018-02-12

    There are two systems as the red channel system and the white channel system carved or painted on the wooden figurine of Laoguanshan of Benque school. The two systems are horizontally staggered each other without overlapped. The red channel system, similar to Shuangbaoshan wooden figurine, have channels, but without points. For the white channel system, the running courses of channels result from the sensation distributions of the points after optional stimulation. The Laoguanshan wooden figurine focuses on the illustration of the white channel system, named as white channel figurine. Compared with the Shuangbaoshan red channel figurine, together with examples, such as the running course of the white channel related to the meridian of heart-transfer-point, the white channel related to the belt vessel linking to lung-transfer-point, stomach-transfer-point and kidney-transfer-point, as well as the corresponding photographs. It is indicated that the Laoguanshan white channel figurine is a training aid for testing the sensation marching along channel (SMC) caused by transfer-point stimulation. The white channel system is a flexible way of channel. The study aims to observe the QI /SMC reaching the affected area and contributes to clinical practice. This discovery is not related to the "intermediate link theory" in the Yellow Emperor meridian system.

  12. Theoretical and experimental study of heat transfers and pressure drops along surfaces fitted with herring-bone fins: correlation between geometric and aero thermal parameters; Etudes theorique et experimentale du transfert de chaleur et des pertes de charge de surfaces munies d'ailettes disposees en chevron - correlation entre parametres geometriques et aerothermiques

    Energy Technology Data Exchange (ETDEWEB)

    Pelce, J.; Malherbe, J.; Pierre, B. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    Principal results are given of experimental research which has been carried out on the flow of a fluid along a surface fitted with herringbone fins. Aero-thermal tests have been effected on a large number of these surfaces whose geometrical parameters have been made to vary systematically. In particular, work on a large scale model has made it possible to analyse the mechanisms of heat transfer and of pressure drops. On this basis a theoretical study has led to the establishment of a correlation between the geometric configuration and the aero-thermal performances of these surfaces. Experimental results are in good agreement with the theoretical relationships. An expression has thus been derived applicable to this type of herring-boned surface in a wide zone. (authors) [French] L'ecoulement d'un fluide au voisinage d'une surface munie d'ailettes disposees en chevron a fait l'objet de recherches experimentales dont on a rappele les principaux resultats. Des essais aerothermiques ont ete effectues sur un grand nombre de ces surfaces dont a fait varier les parametres geometriques de facon systematique. En particulier, des etudes sur une maquette a grande echelle ont permis d'analyser les mecanismes de transfert de chaleur et de perte de charge. Sur ces bases, une etude theorique a conduit a des correlations entre la geometrie et les performances aerothermiques de ces surfaces. Les resultats experimentaux sont en bon accord avec les relations theoriques. On possede ainsi une formulation pour ce type de surface ailettee valable dans un domaine etendu. (auteurs)

  13. Interim analysis based on the weighted log-rank test for delayed treatment effects under staggered patient entry.

    Science.gov (United States)

    Yoshida, Mizuki; Matsuyama, Yutaka

    2016-01-01

    Fleming and Harrington's G(ρ,γ) class of weighted log-rank tests is appropriate for detecting delayed treatment effects such as those seen in cancer vaccines. A conditional power (CP) and an alpha spending function (ASF) approach are useful for interim analyses that are conducted with the aim of early termination due to futility and efficacy, respectively. However, calculation of the CP and the total Type I error probability are often not considered for delayed effects under the staggered patient entry. In this article, we first propose methods for calculating the CP analytically based on the weighted log-rank test. We compared the performances of the proposed methods with two other methods (i.e., usual log-rank test and optimal one) under the delayed alternatives. Our simulations demonstrated that the CP based on the weighted log-rank test was more powerful than that of the usual log-rank test and was comparable to the CP based on the optimal log-rank test. Second, we quantitatively evaluated the degree to which the Type I error probability was inflated when an ASF approach with forced independent increments assumption was applied to the weighted log-rank test. The proposed method will provide valuable tools in the decision-making stage of the interim analysis.

  14. Localizing gene regulation reveals a staggered wood decay mechanism for the brown rot fungus Postia placenta

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiwei; Presley, Gerald N.; Hammel, Kenneth E.; Ryu, Jae-San; Menke, Jon R.; Figueroa, Melania; Hu, Dehong; Orr, Galya; Schilling, Jonathan S.

    2016-09-12

    The fungi that cause brown rot of wood are essential contributors to biomass recycling in forest ecosystems. Their highly efficient cellulolytic systems, which may have practical applications, apparently depend on a combination of two mechanisms: nonselective oxidation of the lignocellulose by reactive oxygen species (ROS) coupled with hydrolysis of the polysaccharide components by a limited set of glycoside hydrolases (GHs). Since the production of strongly oxidizing ROS appears incompatible with the operation of GHs, it has been proposed that the fungi regulate ROS production by maintaining concentration gradients of the chelated metal ions they use to generate extracellular oxidants. However, calculations have indicated that this protective mechanism is physically infeasible. We examined a different hypothesis, that expression of ROS and GH components is temporally staggered by brown rot fungi in wood. We sectioned thin wafers of spruce and aspen that had been colonized directionally by Postia placenta and measured expression of relevant genes and some of the encoded enzymes, thus using the spatial distribution of fungal hyphae to resolve a fine-scale temporal sequence. Hierarchical clustering of gene expression for eight oxidoreductases thought to have a role in ROS production and of eight GHs revealed a zone of oxidoreductase upregulation at the hyphal front that persisted about 48 h before upregulation of the GHs. Additional evidence for differential expression was provided by localization of endoglucanase, xylanase, mannanase, and laccase activities in the colonized wood. Our results support a two-step mechanism for brown rot, in which substrate oxidation precedes enzymatic hydrolysis.

  15. Analysis and Optimization of a Novel 2-D Magnet Array with Gaps and Staggers for a Moving-Magnet Planar Motor

    Science.gov (United States)

    Chen, Xuedong; Zeng, Lizhan

    2018-01-01

    This paper presents a novel 2-D magnet array with gaps and staggers, which is especially suitable for magnetically levitated planar motor with moving magnets. The magnetic flux density distribution is derived by Fourier analysis and superposition. The influences of gaps and staggers on high-order harmonics and flux density were analyzed, and the optimized design is presented. Compared with the other improved structures based on traditional Halbach magnet arrays, the proposed design has the lowest high-order harmonics percentage, and the characteristics of flux density meet the demand of high acceleration in horizontal directions. It is also lightweight and easy to manufacture. The proposed magnet array was built, and the calculation results have been verified with experiment. PMID:29300323

  16. Dynamic Channel Allocation

    Science.gov (United States)

    2003-09-01

    21 9. Beowulf Ethernet Channel Bonding.................................................22 F. SUMMARY...on demand, hybrid channel allocation in wireless networks, and 3 Beowulf Ethernet channel bonding. The background information presented in this...channels are available for dynamic allocation [Ref 32]. 9. Beowulf Ethernet Channel Bonding A by-product of using older computers in a NASA research lab

  17. Theoretical investigation of GaAsBi/GaAsN tunneling field-effect transistors with type-II staggered tunneling junction

    Science.gov (United States)

    Wang, Yibo; Liu, Yan; Han, Genquan; Wang, Hongjuan; Zhang, Chunfu; Zhang, Jincheng; Hao, Yue

    2017-06-01

    We investigate GaAsBi/GaAsN system for the design of type-II staggered hetero tunneling field-effect transistor (hetero-TFET). Strain-symmetrized GaAsBi/GaAsN with effective lattice match to GaAs exhibits a type-II band lineup, and the effective bandgap EG,eff at interface is significantly reduced with the incorporation of Bi and N elements. The band-to-band tunneling (BTBT) rate and drive current of GaAsBi/GaAsN hetero-TFETs are boosted due to the utilizing of the type-II staggered tunneling junction with the reduced EG,eff. Numerical simulation shows that the drive current and subthreshold swing (SS) characteristics of GaAsBi/GaAsN hetero-TFETs are remarkably improved by increasing Bi and N compositions. The dilute content GaAs0.85Bi0.15/GaAs0.92N0.08 staggered hetero-nTFET achieves 7.8 and 550 times higher ION compared to InAs and In0.53Ga0.47As homo-TFETs, respectively, at the supply voltage of 0.3 V. GaAsBi/GaAsN heterostructure is a potential candidate for high performance TFET.

  18. A Study of the Transient Response of Duct Junctions: Measurements and Gas-Dynamic Modeling with a Staggered Mesh Finite Volume Approach

    Directory of Open Access Journals (Sweden)

    Antonio J. Torregrosa

    2017-05-01

    Full Text Available Duct junctions play a major role in the operation and design of most piping systems. The objective of this paper is to establish the potential of a staggered mesh finite volume model as a way to improve the description of the effect of simple duct junctions on an otherwise one-dimensional flow system, such as the intake or exhaust of an internal combustion engine. Specific experiments have been performed in which different junctions have been characterized as a multi-port, and that have provided precise and reliable results on the propagation of pressure pulses across junctions. The results obtained have been compared to simulations performed with a staggered mesh finite volume method with different flux limiters and different meshes and, as a reference, have also been compared with the results of a more conventional pressure loss-based model. The results indicate that the staggered mesh finite volume model provides a closer description of wave dynamics, even if further work is needed to establish the optimal calculation settings.

  19. A Priori Estimates of Solution of a Homogeneous Boundary Value Problem for Parabolic Type Equations by the Discontinuous Galerkin Method on Staggered Grids

    Directory of Open Access Journals (Sweden)

    Ruslan V. Zhalnin

    2017-12-01

    Full Text Available Introduction: In this paper, we present a priori error analysis of the solution of a homogeneous boundary value problem for a second-order differential equation by the discontinuous Galerkin method on staggered grids. Materials and Methods: This study is based on the unified hp-version error analysis of local discontinuous Galerkin method proposed by Castillo et al. [Optimal a priori error estimates for the hp-version of the local discontinuous Galerkin method for convection-diffusion problems, 2002]. The purpose of this paper is to present a new approach to the error analysis of the solution of parabolic equations by the discontinuous Galerkin method on staggered grids. Results: We suggest that approximation errors depend on the characteristic size of the cells and the degree of polynomials used in the basis functions. The necessary lemmas are formulated for the problem solution. The complete proof of the lemmas formulated is carried out. We formulated and proved a theorem, in which a priori error estimates are given for solving parabolic equations using the discontinuous Galerkin method on staggered grids Discussion and Conclusions: The obtained results are consistent with similar studies of other authors and complement them. Further work on this topic involves the study of diffusion-type equations of order higher than the first and the production of a posteriori error estimates.

  20. A simple and universal ligation mediated fusion of genes based on hetero-staggered PCR for generating immunodominant chimeric proteins.

    Science.gov (United States)

    Reddy, Prakash K; Ramlal, Shylaja; Sripathy, Murali H; Batra, Harshvardhan

    2012-11-01

    We developed a simple T4 DNA ligase mediated strategy for inframe splicing of two or more cohesive genes generated by hetero-staggered PCR and directionally cloning the spliced product bearing sticky overhangs in to a correspondingly cut vector. For this, two pairs of primers are used in two different parallel PCRs, for generation of each cohesive gene product. We exemplified this strategy by splicing two major super-antigen genes of Staphylococcus aureus, namely, staphylococcal enterotoxin A (sea), and toxic shock syndrome toxin (tsst-1) followed by its directional cloning into pre-digested pRSET A vector. The fusion gene encoding chimeric recombinant SEA-TSST protein (32kDa) was expressed in E. coli BL21(DE3) host strain. The recombinant chimeric protein retained the antigenicity of both toxins as observed by the strong immunoreactivity with commercial antibodies against both SEA and TSST-1 toxin components by Western blot analysis. We observed that the present method for gene splicing with cohesive ends is simple since it does not require elaborate standardization and a single fusion product is obtained consistently during nested PCR with forward primer of first gene and reverse primer of second gene. For comparison, we fused the same genes using splicing by overlap extension PCR (SOE-PCR) and consistently obtained DNA smearing and multiple non-specific bands even after several rounds of PCRs from gel excised product. Moreover, the newly described method requires only two to six complimentary sticky ends between the genes to be spliced, in contrast to long stretch of overlapping nucleotides in case of SOE-PCR. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. A Study on the Uncertainty of Flow-Induced Vibration in a Cross Flow over Staggered Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji-Su; Park, Jong-Woon [Dongguk univ, Gyeong Ju (Korea, Republic of); Choi, Hyeon-Kyeong [HanNam University, Daejeon (Korea, Republic of)

    2015-05-15

    Cross-flow in many support columns of very high temperature reactor (VHTR) lower plenum would have FIV issues under high speed flow jetting from the core. For a group of multiple circular cylinders subjected to a cross-flow, three types of potential vibration mechanisms may exist: (1) Vortex-induced vibration (VIV), (2) Fluid-elastic vibration (FEV) and (3) Turbulence-induced vibration (TIV). Kevalahan studied the free vibration of circular cylinders in a tightly packed periodic square inline array of cylinders. Pandey et al. studied the flue gas flow distribution in the Low Temperature Super Heater (LTSH) tube bundles situated in second pass of a utility boiler and the phenomenon of flow induced vibration. Nakamura et al. studied flow instability of cylinder arrays resembling U-bend tubes in steam generators. The FIV evaluation is usually performed with computational fluid dynamic (CFD) analysis to obtain unknown frequency of oscillation of the multiple objects under turbulent flow and thus the uncertainty residing in the turbulence model used should be quantified. In this paper, potential FIV uncertainty arising from the turbulence phenomena are evaluated for a typical cross flow through staggered tube bundles resembling the VHTR lower plenum support columns. Flow induced vibration (FIV) is one of the important mechanical and fatigue issues in nuclear systems. Especially, cross-flow in many support structures of VHTR lower plenum would have FIV issues under highly turbulent jet flows from the core. The results show that the effect of turbulence parameters on FIV is not negligible and the uncertainty is 5 to 10%. Present method can be applied to future FIV evaluations of nuclear systems. More extensive studies on flow induced vibration in a plant scale by using more rigorous computational methods are under way.

  2. Theoretical study of O- and Zn-face polarity effect on the optical properties of the conventional and staggered ZnO/Zn{sub 1−x}Cd{sub x}O/ZnO quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Shtepliuk, I., E-mail: ivan.shtepliuk@liu.se; Khranovskyy, V.; Yakimova, R.

    2015-11-02

    In this work we present a comparative study of Zn-face and O-face polarity Zn{sub 1−x}CdxO-based conventional and staggered quantum-well (QW) structures. The calculation of optical properties of QWs was performed by means of self-consistent Schrodinger–Poisson solver with consideration of polarization-induced effects. The conventional Zn-face and O-face QWs possess similar values of transition energy and an overlap of electron and hole wave functions. A change of the polarity from Zn-face to O-face for the conventional QWs influences only a shape of the conduction and valence band edge profile. It is revealed that the utilization of the staggered QWs leads to an improvement of the confinement characteristics. In addition, the O-face staggered QW structure has larger values of transition energy and overlap integral compared to the Zn-face staggered QW structure. O-terminated staggered QW structure is less dependent on the well thickness and has lower sensitivity to Cd content in embedded Zn{sub 1−x}CdxO layer. Control of the material polarity and design of the staggered QWs provide cost-effective approach for engineering the QW band structures with enhanced QW performance. This enables constructing of the Zn{sub 1−x}CdxO-based light emission diodes with improved radiative efficiency emitting, applicable for solid state lighting. - Highlights: • Effect of polar face on properties of Zn{sub 1−x}Cd{sub x}O quantum wells (QWs) was studied. • O-face staggered QWs were found to possess improved optical properties. • Sensitivity of transition energy to well width was found to be weaker for O-face QW. • Using of the embedded layer in QW reduces quantum confinement Stark effect.

  3. Comparison of the 2nd-order and 4th-order Staggered-Grid Finite-Difference Implementations of the TSN Method for Rupture Propagation

    Science.gov (United States)

    Kristek, J.; Moczo, P.; Galis, M.

    2006-12-01

    The TSN (Traction-at-Split-Nodes) method has been developed independently by Andrews (1973, 1976, 1999) and Day (1977, 1982). Andrews implemented his TSN formulation in the finite-difference scheme in which spatial differentiation is equivalent to the 2nd-order finite-element method. Day implemented his slightly different formulation of the TSN method in the 2nd-order partly-staggered finite-difference scheme. Dalguer and Day (2006) adapted the TSN method to the velocity-stress staggered-grid finite-difference scheme. Whereas the 4th-order spatial differencing is applied outside the fault, the 2nd-order differencing is applied along the fault plane. We present two implementations of the Day's TSN formulation in the velocity-stress staggered-grid finite-difference scheme for a 3D viscoelastic medium. In the first one we apply the 2nd-order spatial differencing everywhere in the grid including derivatives at the fault in the direction perpendicular to the fault plane. In the second implementation we similarly apply the 4th-order spatial differencing. In both cases we use the adjusted finite-difference approximations (AFDA, Kristek et al. 2002, Moczo et al. 2004) to derivatives in the direction perpendicular to the fault plane in order to have the same order of approximation everywhere. We numerically investigate convergence rates of both implementations with respect to rupture-time, final-slip, and peak-slip-rate metrics. Moreover, we compare the numerical solutions to those obtained by the finite-element implementation of the TSN method.

  4. Virological failure of staggered and simultaneous treatment interruption in HIV patients who began Efavirenz-based regimens after allergic reactions to nevirapine

    Directory of Open Access Journals (Sweden)

    Siripassorn Krittaecho

    2013-01-01

    Full Text Available Abstract Objective The objective of this work was to study the virological outcomes associated with two different types of treatment interruption strategies in patients with allergic reactions to nevirapine (NVP. We compared the virological outcomes of (1 HIV-1-infected patients who discontinued an initial NVP-based regimen because of cutaneous allergic reactions to NVP; different types of interruption strategies were used, and second-line regimen was based on efavirenz (EFV; and (2 HIV-1-infected patients who began an EFV-based regimen as a first-line therapy (controls. Methods This retrospective cohort included patients who began an EFV-based regimen, between January 2002 and December 2008, as either an initial regimen or as a subsequent regimen after resolving a cutaneous allergic reaction against an initial NVP-based regimen. The study ended in March 2010. The primary outcome was virological failure, which was defined as either (a two consecutive plasma HIV-1 RNA levels >400 copies/mL or (b a plasma HIV-1 RNA level >1,000 copies/mL plus any genotypic resistance mutation. Results A total of 559 patients were stratified into three groups: (a Simultaneous Interruption, in which the subjects simultaneously discontinued all the drugs in an NVP-based regimen following an allergic reaction (n=161; (b Staggered Interruption, in which the subjects discontinued NVP treatment while continuing nucleoside reverse transcriptase inhibitor (NRTI backbone therapy for a median of 7 days (n=82; and (c Control, in which the subjects were naïve to antiretroviral therapy (n=316. The overall median follow-up time was 43 months. Incidence of virological failure in Simultaneous Interruption was 12.9 cases per 1,000 person-years, which trended toward being higher than the incidences in Staggered Interruption (5.4 and Control (6.6. However, differences were not statistically significant. Conclusions Among the patients who had an acute allergic reaction to first

  5. New Channels, New Possibilities

    DEFF Research Database (Denmark)

    Pieterson, Willem; Ebbers, Wolfgang; Østergaard Madsen, Christian

    2017-01-01

    In this contribution we discuss the characteristics of what we call the fourth generation of public sector service channels: social robots. Based on a review of relevant literature we discuss their characteristics and place into multi-channel models of service delivery. We argue that social robots...... is not one homogenous type of channels, but rather breaks down in different (sub)types of channels, each with different characteristics and possibilities to supplement and/or replace existing channels. Given the variety of channels, we foresee challenges in incorporating these new channels in multi-channel...... models of service delivery. This is especially relevant given the current lack of evaluations of such models, the broad range of channels available, and their different stages of deployment at governments around the world. Nevertheless, social robots offer an potentially very relevant addition...

  6. Hadamard quantum broadcast channels

    Science.gov (United States)

    Wang, Qingle; Das, Siddhartha; Wilde, Mark M.

    2017-10-01

    We consider three different communication tasks for quantum broadcast channels, and we determine the capacity region of a Hadamard broadcast channel for these various tasks. We define a Hadamard broadcast channel to be such that the channel from the sender to one of the receivers is entanglement-breaking and the channel from the sender to the other receiver is complementary to this one. As such, this channel is a quantum generalization of a degraded broadcast channel, which is well known in classical information theory. The first communication task we consider is classical communication to both receivers, the second is quantum communication to the stronger receiver and classical communication to other, and the third is entanglement-assisted classical communication to the stronger receiver and unassisted classical communication to the other. The structure of a Hadamard broadcast channel plays a critical role in our analysis: The channel to the weaker receiver can be simulated by performing a measurement channel on the stronger receiver's system, followed by a preparation channel. As such, we can incorporate the classical output of the measurement channel as an auxiliary variable and solve all three of the above capacities for Hadamard broadcast channels, in this way avoiding known difficulties associated with quantum auxiliary variables.

  7. Universal scaling of Néel temperature, staggered magnetization density, and spin-wave velocity of three-dimensional disordered and clean quantum antiferromagnets

    Science.gov (United States)

    Tan, D.-R.; Jiang, F.-J.

    2017-02-01

    The Néel temperature, staggered magnetization density, as well as the spin-wave velocity of a three-dimensional (3D) quantum Heisenberg model with antiferromagnetic disorder (randomness) are calculated using first-principles nonperturbative quantum Monte Carlo simulations. In particular, we examine the validity of universal scaling relations that are related to these three studied physical quantities. These relations are relevant to experimental data and are firmly established for clean (regular) 3D dimerized spin-1/2 Heisenberg models. Remarkably, our numerical results show that the considered scaling relations remain true for the investigated model with the introduced disorder. In addition, while the presence of disorder may change the physical properties of regular dimerized models, hence leading to different critical theories, both the obtained data of Néel temperature and staggered magnetization density in our study are fully compatible with the expected critical behavior for clean dimerized systems. As a result, it is persuasive to conclude that the related quantum phase transitions of the considered disordered model and its clean analogues are governed by the same critical theory, which is not always the case in general. Finally, we also find smooth scaling curves even emerging when both the data of the investigated disordered model as well as its associated clean system are taken into account concurrently. This in turn implies that, while in a restricted sense, the considered scaling relations for 3D spin-1/2 antiferromagnets are indeed universal.

  8. Identical Bands and ΔI=2 Staggering in Superdeformed Nuclei in A~150 Mass Region Using Three Parameters Rotational Model

    Directory of Open Access Journals (Sweden)

    Khalaf A. M.

    2012-10-01

    Full Text Available By using a computer simulated search program, the experimental gamma transition en- ergies for superdeformed rotational bands (SDRB’s in A 150 region are fitted to proposed three-parameters model. The model parameters and the spin of the bandhead were obtained for the selected ten SDRB’s namely: 150 Gd (yrast and excited SD bands, 151 Tb (yrast and excited SD bands, 152 Dy (yrast SD bands, 148 Gd (SD-1,SD-6, 149 Gd (SD-1, 153 Dy (SD-1 and 148 Eu (SD-1. The Kinematic J (1 and dynamic J (2 moments of inertia are studied as a function of the rotational frequency ~ ω . From the calculated results, we notic that the excited SD bands have identical energies to their Z + 1 neigh- bours for the twinned SD bands in N = 86 nuclei. Also the analysis done allows us to confirm Δ I = 2 staggering in the yrast SD bands of 148 Gd, 149 Gd, 153 Dy, and 148 Eu and in the excited SD bands of 148 Gd, by performing a staggering parameter analysis. For each band, we calculated the deviation of the gamma ray energies from smooth ref- erence representing the finite di ff erence approximation to the fourth derivative of the gamma ray transition energies at a given spin.

  9. Calcium Channel Blockers

    Science.gov (United States)

    ... conditions, such as Raynaud's disease For people of African heritage and older people, calcium channel blockers might ... high-blood-pressure/in-depth/calcium-channel-blockers/ART-20047605 . Mayo Clinic Footer Legal Conditions and Terms ...

  10. KV7 potassium channels

    DEFF Research Database (Denmark)

    Stott, Jennifer B; Jepps, Thomas Andrew; Greenwood, Iain A

    2014-01-01

    Potassium channels are key regulators of smooth muscle tone, with increases in activity resulting in hyperpolarisation of the cell membrane, which acts to oppose vasoconstriction. Several potassium channels exist within smooth muscle, but the KV7 family of voltage-gated potassium channels have been...

  11. Quantum Channels With Memory

    International Nuclear Information System (INIS)

    Rybar, T.

    2012-01-01

    Quantum memory channels represent a very general, yet simple and comprehensible model for causal processes. As such they have attracted considerable research interest, mostly aimed on their transfer capabilities and structure properties. Most notably it was shown that memory channels can be implemented via physically naturally motivated collision models. We also define the concept of repeatable channels and show that only unital channels can be implemented repeat ably with pure memory channels. In the special case of qubit channels we also show that every unital qubit channel has a repeatable implementation. We also briefly explore the possibilities of stroboscopical simulation of channels and show that all random unitary channels can be stroboscopically simulated. Particularly in qubit case, all indivisible qubit channels are also random unitary, hence for qubit all indivisible channels can be stroboscopically simulated. Memory channels also naturally capture the framework of correlated experiments. We develop methods to gather and interpret data obtained in such setting and in detail examine the two qubit case. We also show that for control unitary interactions the measured data will never contradict a simple unitary evolution. Thus no memory effects can be spotted then. (author)

  12. Channel morphology [Chapter 5

    Science.gov (United States)

    Jonathan W. Long; Alvin L. Medina; Daniel G. Neary

    2012-01-01

    Channel morphology has become an increasingly important subject for analyzing the health of rivers and associated fish populations, particularly since the popularization of channel classification and assessment methods. Morphological data can help to evaluate the flows of sediment and water that influence aquatic and riparian habitat. Channel classification systems,...

  13. LaMEM: a Massively Parallel Staggered-Grid Finite-Difference Code for Thermo-Mechanical Modeling of Lithospheric Deformation with Visco-Elasto-Plastic Rheologies

    Science.gov (United States)

    Kaus, B.; Popov, A.

    2014-12-01

    The complexity of lithospheric rheology and the necessity to resolve the deformation patterns near the free surface (faults and folds) sufficiently well places a great demand on a stable and scalable modeling tool that is capable of efficiently handling nonlinearities. Our code LaMEM (Lithosphere and Mantle Evolution Model) is an attempt to satisfy this demand. The code utilizes a stable and numerically inexpensive finite difference discretization with the spatial staggering of velocity, pressure, and temperature unknowns (a so-called staggered grid). As a time discretization method the forward Euler, or a combination of the predictor-corrector and the fourth-order Runge-Kutta can be chosen. Elastic stresses are rotated on the markers, which are also used to track all relevant material properties and solution history fields. The Newtonian nonlinear iteration, however, is handled at the level of the grid points to avoid spurious averaging between markers and grid. Such an arrangement required us to develop a non-standard discretization of the effective strain-rate second invariant. Important feature of the code is its ability to handle stress-free and open-box boundary conditions, in which empty cells are simply eliminated from the discretization, which also solves the biggest problem of the sticky-air approach - namely large viscosity jumps near the free surface. We currently support an arbitrary combination of linear elastic, nonlinear viscous with multiple creep mechanisms, and plastic rheologies based on either a depth-dependent von Mises or pressure-dependent Drucker-Prager yield criteria.LaMEM is being developed as an inherently parallel code. Structurally all its parts are based on the building blocks provided by PETSc library. These include Jacobian-Free Newton-Krylov nonlinear solvers with convergence globalization techniques (line search), equipped with different linear preconditioners. We have also implemented the coupled velocity-pressure multigrid

  14. Combustion wave propagation regimes in a channel equipped with an array of cross-flow cylindrical obstacles

    Science.gov (United States)

    Pinos, Thomas Arthur Richard

    Flame propagation through a channel equipped with obstacles was studied experimentally. Two types of obstacle geometries were investigated, i.e., wall-mounted cross-flow cylinders and fence-type obstacles mounted on the top and bottom channel surfaces. The motivation for this research is its applications to both high-speed propulsion and industrial explosion safety. The effect of obstacle distribution and blockage ratio on flame acceleration was investigated in a 2.54cm x 7.6cm "narrow" channel with wall-mounted cross-flow cylindrical obstacles. The cylinders were arranged in a "staggered" or "inline" pattern, with blockage ratios of 0.5 and 0.67. Schlieren images were used to study the flame shape and its leading edge velocity for a range of fuel-air mixtures compositions. It was determined that initial flame propagation occurs faster in higher blockage ratios due to the higher frequency perturbation to the flow. Flame acceleration led to different quasi-steady flame and detonation propagation regimes. In general, higher final steady flame velocities were reached in the lower blockage ratios, and detonation limits were found to be influenced by the geometry. The influence of channel width on flame acceleration was also determined using fence-type obstacles with a single blockage ratio. Experiments were performed in a 2.54cm x 7.6cm and 7.6cm x 7.6cm channel. Schlieren images were again used to study the flame shape and to obtain leading edge velocity. The flame tip was found to have a parabolic profile across the channel width for the narrower channel and flatter profile in the wider channel. It was determined that the channel width has a weak effect on the flame velocity down the channel length. As such, flame acceleration was initially only slightly more pronounced in the narrow channel before the reverse became true later in the wide channel.

  15. Marginal flow and gap flow in strongly staggered cascades of slightly convex profiles; Rand- und Spaltstroemungen in stark gestaffelten Verdichtergittern aus schwach gewoelbten Profilen

    Energy Technology Data Exchange (ETDEWEB)

    Sasongko, H. [Technische Univ. Braunschweig (Germany). Inst. fuer Stroemungsmechanik

    1997-09-01

    Marginal flow and gap flow through a highly staggered cascade consisting of slightly convex profiles were investigated in two steps. Cascades without gap were investigated in the first step and cascades with gap in the second. In the first step, a slightly staggered cascade of identical geometry was used for comparison. In the second step, an external rotor cascade of 9C7/32,5C50 profiles with a division ratio t/l = 1.0 and a staggering angle of {lambda} = 50 was used. At a Reynolds number Re{sub j} = 3.5 x 10{sup 5} and gap widths of s/l = 0.0, 0.01 and 0.3, flows, wakes and pressure distributions were measured and diagrams made. The measurements were evaluated by mass averaging and with the aid of the pulse method. In addition to the averaged results of a standard investigation, the dissertation comprises extensive data on 3D flow near the blade ends and at the side wall as a function of blade angles and gap widths between blades and side wall. This was the first time that marginal flow and gap flow of strongly staggered cascades with slightly convex profiles were investigated in a cascade wind tunnel. The findings are therefore quite new and deviate strongly from the results of earlier investigations on strongly convex profiles. The findings were compared with the results of compressor investigations, and good agreement was found. (orig./AKF) [Deutsch] Die vorliegende Arbeit berichtet ueber die in zwei Schritten durchgefuehrten Untersuchungen der Rand- und Spaltstroemungen eines hoch gestaffelten Verdichtergitters aus schwach gewoelbten Profilen. Im ersten Schritt wurde das Gitter ohne Spalt, im zweiten Schritt mit Spalt untersucht. Vergleichsgitter im ersten Schritt war ein zusaetzlich untersuchtes Gitter schwacher Staffelung mit sonst gleicher Geometrie. Vergleichsgitter im zweiten Schritt war das hoch gestaffelte Gitter aus dem ersten Schritt. Das untersuchte Verdichtergitter ist ein Rotor-Aussenschnitt-Gitter aus 9C7/32,5C50-Profilen mit einem

  16. Experimental process investigation of a latent heat energy storage system with a staggered heat exchanger with different phase change materials for solar thermal energy storage applications

    Science.gov (United States)

    Tsolakoglou, Nikolas P.; Koukou, Maria K.; Vrachopoulos, Michalis Gr.; Tachos, Nikolaos; Lymberis, Kostas; Stathopoulos, Vassilis

    2017-11-01

    This work investigates melting and solidification processes of four different Phase Change Materials (PCM) used as latent heat thermal storage system. The experimental rig was consisted of an insulated tank, filled with the under investigation PCM, a staggered heat exchanger to supply or extract heat from the PCM cavity and a water pump to circulate Heat Transfer Fluid (HTF). Both charging (melting) and discharging (solidification) processes were conducted for two different HTF flow rates. The main scope of this work was to develop a first approach and to investigate the behaviour of PCM under various load conditions (different HTF flow rates). Results show that different HTF flow rates affect melting and solidification time periods; in both processes time was reduced while HTF flow rate was increased but in differentways due to the transition from conduction to convection heat transfer mechanisms.

  17. Experimental process investigation of a latent heat energy storage system with a staggered heat exchanger with different phase change materials for solar thermal energy storage applications

    Directory of Open Access Journals (Sweden)

    Tsolakoglou Nikolas P.

    2017-01-01

    Full Text Available This work investigates melting and solidification processes of four different Phase Change Materials (PCM used as latent heat thermal storage system. The experimental rig was consisted of an insulated tank, filled with the under investigation PCM, a staggered heat exchanger to supply or extract heat from the PCM cavity and a water pump to circulate Heat Transfer Fluid (HTF. Both charging (melting and discharging (solidification processes were conducted for two different HTF flow rates. The main scope of this work was to develop a first approach and to investigate the behaviour of PCM under various load conditions (different HTF flow rates. Results show that different HTF flow rates affect melting and solidification time periods; in both processes time was reduced while HTF flow rate was increased but in differentways due to the transition from conduction to convection heat transfer mechanisms.

  18. HIPPI and Fibre Channel

    International Nuclear Information System (INIS)

    Tolmie, D.E.

    1992-01-01

    The High-Performance Parallel Interface (HIPPI) and Fibre Channel are near-gigabit per second data communications interfaces being developed in ANSI standards Task Group X3T9.3. HIPPI is the current interface of choice in the high-end and supercomputer arena, and Fibre Channel is a follow-on effort. HIPPI came from a local area network background, and Fibre Channel came from a mainframe to peripheral interface background

  19. Semileptonic B to D Decays at Nonzero Recoil with 2+1 Flavors of Improved Staggered Quarks

    International Nuclear Information System (INIS)

    Qiu, Si-Wei; DeTar, Carleton; Du, Daping; Kronfeld, Andreas S.; Laiho, Jack; Van de Water, Ruth S.

    2011-01-01

    The Fermilab Lattice-MILC collaboration is completing a comprehensive program of heavy-light physics on the MILC (2+1)-flavor asqtad ensembles with lattice spacings as small as 0.045 fm and light-to-strange-quark mass ratios as low as 1/20. We use the Fermilab interpretation of the clover action for heavy valence quarks and the asqtad action for light valence quarks. The central goal of the program is to provide ever more exacting tests of the unitarity of the CKM matrix. We give a progress report on one part of the program, namely the analysis of the semileptonic decay B to D at both zero and nonzero recoil. Although final results are not presented, we discuss improvements in the analysis methods, the statistical errors, and the parameter coverage that we expect will lead to a significant reduction in the final error for |V cb | from this decay channel.

  20. Ion Channels in Leukocytes

    Science.gov (United States)

    1991-07-01

    be fitted to a Hodgkin - conductance. K (1.0) > Rb (0.77) > NH4 (0.10) > Cs Huxley type n4j model (17, 38). However, the rate of K0 (0.02) > Na (ɘ.01...15, 25 activated) T- and B-cells, murine B-cells? SCG, single-channel conductance under physiological ionic gradient- tfor ructif~ y ig ehannel, largest...the channel induces a confor- kat T-cell line (52). Fina:! y , single-channel recordings of mational change that ina.-tix ates the channel rather human T

  1. A channel profile analyser

    International Nuclear Information System (INIS)

    Gobbur, S.G.

    1983-01-01

    It is well understood that due to the wide band noise present in a nuclear analog-to-digital converter, events at the boundaries of adjacent channels are shared. It is a difficult and laborious process to exactly find out the shape of the channels at the boundaries. A simple scheme has been developed for the direct display of channel shape of any type of ADC on a cathode ray oscilliscope display. This has been accomplished by sequentially incrementing the reference voltage of a precision pulse generator by a fraction of a channel and storing ADC data in alternative memory locations of a multichannel pulse height analyser. Alternative channels are needed due to the sharing at the boundaries of channels. In the flat region of the profile alternate memory locations are channels with zero counts and channels with the full scale counts. At the boundaries all memory locations will have counts. The shape of this is a direct display of the channel boundaries. (orig.)

  2. Real time stagger of electric network advanced analysis functions of a modern control center; Escalonamento em tempo real das funcoes avancadas de analise de rede eletrica de um moderno centro de controle

    Energy Technology Data Exchange (ETDEWEB)

    Zagari, Eduardo Nicola Ferraz

    1996-02-01

    This work presents two models for implementation of staggers for network analysis functions in real time for a control center. The methodology is described. Tests were performed in a electric power system of Campinas region, Sao Paulo sate - Southeast Brazil. Results are presented.

  3. A linearization of quantum channels

    Science.gov (United States)

    Crowder, Tanner

    2015-06-01

    Because the quantum channels form a compact, convex set, we can express any quantum channel as a convex combination of extremal channels. We give a Euclidean representation for the channels whose inverses are also valid channels; these are a subset of the extreme points. They form a compact, connected Lie group, and we calculate its Lie algebra. Lastly, we calculate a maximal torus for the group and provide a constructive approach to decomposing any invertible channel into a product of elementary channels.

  4. DESIGN OF PARABOLIC CHANNELS

    Directory of Open Access Journals (Sweden)

    A. K. Alibekov

    2015-01-01

    Full Text Available The dependence of the apparent location of the hydraulic parameters of parabolic channels in earthen channel and volume of dredging required in their design and construction, on the basis of conditions to ensure the stability of the slope at the maximum water flow rate. 

  5. Calcium channel blocker overdose

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002580.htm Calcium-channel blocker overdose To use the sharing features on this ... vary. However, the main ingredient is called a calcium-channel antagonist. It helps decrease the heart's pumping strength, which ...

  6. CHANNEL ESTIMATION TECHNIQUE

    DEFF Research Database (Denmark)

    2015-01-01

    the communication channel. The method further includes determining a sequence of second coefficient estimates of the communication channel based on a decomposition of the first coefficient estimates in a dictionary matrix and a sparse vector of the second coefficient estimates, the dictionary matrix including...

  7. Athermalized channeled spectropolarimeter enhancement.

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Julia Craven; Way, Brandyn Michael; Mercier, Jeffrey Alan; Hunt, Jeffery P.

    2013-09-01

    Channeled spectropolarimetry can measure the complete polarization state of light as a function of wavelength. Typically, a channeled spectropolarimeter uses high order retarders made of uniaxial crystal to amplitude modulate the measured spectrum with the spectrally-dependent Stokes polarization information. A primary limitation of conventional channeled spectropolarimeters is related to the thermal variability of the retarders. Thermal variation often forces frequent system recalibration, particularly for field deployed systems. However, implementing thermally stable retarders, made of biaxial crystal, results in an athermal channeled spectropolarimeter that relieves the need for frequent recalibration. This report presents experimental results for an anthermalized channeled spectropolarimeter prototype produced using potassium titanyl phosphate. The results of this prototype are compared to the current thermal stabilization state of the art. Finally, the application of the technique to the thermal infrared is studied, and the athermalization concept is applied to an infrared imaging spectropolarimeter design.

  8. Cardiac potassium channel subtypes

    DEFF Research Database (Denmark)

    Schmitt, Nicole; Grunnet, Morten; Olesen, Søren-Peter

    2014-01-01

    . The underlying posttranscriptional and posttranslational remodeling of the individual K(+) channels changes their activity and significance relative to each other, and they must be viewed together to understand their role in keeping a stable heart rhythm, also under menacing conditions like attacks of reentry......About 10 distinct potassium channels in the heart are involved in shaping the action potential. Some of the K(+) channels are primarily responsible for early repolarization, whereas others drive late repolarization and still others are open throughout the cardiac cycle. Three main K(+) channels...... that they could constitute targets for new pharmacological treatment of atrial fibrillation. The interplay between the different K(+) channel subtypes in both atria and ventricle is dynamic, and a significant up- and downregulation occurs in disease states such as atrial fibrillation or heart failure...

  9. Muon cooling channels

    CERN Document Server

    Eberhard-K-Kei

    2003-01-01

    A procedure uses the equations that govern ionization cooling, and leads to the most important parameters of a muon cooling channel that achieves assumed performance parameters. First, purely transverse cooling is considered, followed by both transverse and longitudinal cooling in quadrupole and solenoid channels. Similarities and differences in the results are discussed in detail, and a common notation is developed. Procedure and notation are applied to a few published cooling channels. The parameters of the cooling channels are derived step by step, starting from assumed values of the initial, final and equilibrium emittances, both transverse and longitudinal, the length of the cooling channel, and the material properties of the absorber. The results obtained include cooling lengths and partition numbers, amplitude functions and limits on the dispersion at the absorber, length, aperture and spacing of the absorber, parameters of the RF system that achieve the longitudinal amplitude function and bucket area ...

  10. Microstructure evolution and mechanical properties of a Ti-35Nb-3Zr-2Ta biomedical alloy processed by equal channel angular pressing (ECAP).

    Science.gov (United States)

    Lin, Zhengjie; Wang, Liqiang; Xue, Xiaobing; Lu, Weijie; Qin, Jining; Zhang, Di

    2013-12-01

    In this paper, an equal channel angular pressing method is employed to refine grains and enhance mechanical properties of a new β Ti-35Nb-3Zr-2Ta biomedical alloy. After the 4th pass, the ultrafine equiaxed grains of approximately 300 nm and 600 nm are obtained at pressing temperatures of 500 and 600°C respectively. The SEM images of billets pressed at 500°C reveal the evolution of shear bands and finally at the 4th pass intersectant networks of shear bands, involving initial band propagation and new band broadening, are formed with the purpose of accommodating large plastic strain. Furthermore, a unique herringbone microstructure of twinned martensitic variants is observed in TEM images. The results of microhardness measurements and uniaxial tensile tests show a significant improvement in microhardness and tensile strength from 534 MPa to 765 MPa, while keeping a good level of ductility (~16%) and low elastic modulus (~59 GPa). The maximum superelastic strain of 1.4% and maximum recovered strain of 2.7% are obtained in the billets pressed at 500°C via the 4th pass, which exhibits an excellent superelastic behavior. Meanwhile, the effects of different accumulative deformations and pressing temperatures on superelasticity of the ECAP-processed alloys are investigated. © 2013. Published by Elsevier B.V. All rights reserved.

  11. Numerical study of the effects of lamp configuration and reactor wall roughness in an open channel water disinfection UV reactor.

    Science.gov (United States)

    Sultan, Tipu

    2016-07-01

    This article describes the assessment of a numerical procedure used to determine the UV lamp configuration and surface roughness effects on an open channel water disinfection UV reactor. The performance of the open channel water disinfection UV reactor was numerically analyzed on the basis of the performance indictor reduction equivalent dose (RED). The RED values were calculated as a function of the Reynolds number to monitor the performance. The flow through the open channel UV reactor was modelled using a k-ε model with scalable wall function, a discrete ordinate (DO) model for fluence rate calculation, a volume of fluid (VOF) model to locate the unknown free surface, a discrete phase model (DPM) to track the pathogen transport, and a modified law of the wall to incorporate the reactor wall roughness effects. The performance analysis was carried out using commercial CFD software (ANSYS Fluent 15.0). Four case studies were analyzed based on open channel UV reactor type (horizontal and vertical) and lamp configuration (parallel and staggered). The results show that lamp configuration can play an important role in the performance of an open channel water disinfection UV reactor. The effects of the reactor wall roughness were Reynolds number dependent. The proposed methodology is useful for performance optimization of an open channel water disinfection UV reactor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Extraction of contact resistance and channel parameters from the electrical characteristics of a single bottom-gate/top-contact organic transistor

    Science.gov (United States)

    Takagaki, Shunsuke; Yamada, Hirofumi; Noda, Kei

    2016-03-01

    A parameter extraction procedure for staggered-type organic field-effect transistors (OFETs), in which only the electrical characteristics of a single device are needed, was newly considered. The existing differential method and the transition voltage method for evaluating contact and channel parameters in OFETs were complementarily combined. The calibration of the total resistance between the source and the drain was also incorporated to compensate discrepancies in the total resistances calculated from output and transfer characteristics, caused by the existence of nonignorable contact resistance and carrier traps. By using our proposed method, gate-voltage-dependent contact resistance and channel mobility in the linear regime were evaluated for bottom-gate/top-contact pentacene thin-film transistors, and the channel-length dependence of these parameters was investigated. A series of results of parameter extraction confirm the validity of our proposed method, which is advantageous in avoiding the influences of characteristic variations that are frequently observed in practical OFET devices.

  13. Utilizing Schottky barriers to suppress short-channel effects in organic transistors

    Science.gov (United States)

    Fernández, Anton F.; Zojer, Karin

    2017-10-01

    Transistors with short channel lengths exhibit profound deviations from the ideally expected behavior. One of the undesired short-channel effects is an enlarged OFF current that is associated with a premature turn on of the transistor. We present an efficient approach to suppress the OFF current, defined as the current at zero gate source bias, in short-channel organic transistors. We employ two-dimensional device simulations based on the drift-diffusion model to demonstrate that intentionally incorporating a Schottky barrier for injection enhances the ON-OFF ratio in both staggered and coplanar transistor architectures. The Schottky barrier is identified to directly counteract the origin of enlarged OFF currents: Short channels promote a drain-induced barrier lowering. The latter permits unhindered injection of charges even at reverse gate-source bias. An additional Schottky barrier hampers injection for such points of operations. We explain how it is possible to find the Schottky barrier of the smallest height necessary to exactly compensate for the premature turn on. This approach offers a substantial enhancement of the ON-OFF ratio. We show that this roots in the fact that such optimal barrier heights offer an excellent compromise between an OFF current diminished by orders of magnitude and an only slightly reduced ON current.

  14. Numerical turbulent convective heat transfer and fluid flow in complex channels

    Energy Technology Data Exchange (ETDEWEB)

    Rokni, M.

    1996-04-01

    This investigation concerns numerical turbulent heat transfer and fluid flow in complex channels for fully developed periodic state. Numerical application of different turbulence models for forced convective heat transfer in three dimensional channels are presented. It also concerns prediction of secondary motions and temperature distribution in straight and corrugated ducts with different cross section area. The standard linear k-e and Speziale`s non-linear k-e models with wall functions are applied to calculate the turbulent shear stresses. SED, GGDH and WET models are used to predict the turbulent heat fluxes. The overall thermal-hydraulic performance is presented in terms of friction factor and Nu-number. Some formulas are also presented to estimate the Nu-number in various wavy channels. The numerical approach is based on the finite volume technique with non-staggered grid arrangement. Rhie-Chow interpolation with SIMPLEC-algorithm is used. The convective terms are treated by hybrid, MUSCL, van Leer and QUICK schemes while the diffusive terms are treated by central difference scheme. The fully developed turbulent state is achieved by imposing periodic conditions in the main flow direction. In general, a numerical method for calculation of turbulent convective heat transfer in complex channels is presented. 4 refs, 3 figs

  15. Validation and Analysis of Numerical Results for a Two-Pass Trapezoidal Channel With Different Cooling Configurations of Trailing Edge.

    Science.gov (United States)

    Siddique, Waseem; El-Gabry, Lamyaa; Shevchuk, Igor V; Fransson, Torsten H

    2013-01-01

    High inlet temperatures in a gas turbine lead to an increase in the thermal efficiency of the gas turbine. This results in the requirement of cooling of gas turbine blades/vanes. Internal cooling of the gas turbine blade/vanes with the help of two-pass channels is one of the effective methods to reduce the metal temperatures. In particular, the trailing edge of a turbine vane is a critical area, where effective cooling is required. The trailing edge can be modeled as a trapezoidal channel. This paper describes the numerical validation of the heat transfer and pressure drop in a trapezoidal channel with and without orthogonal ribs at the bottom surface. A new concept of ribbed trailing edge has been introduced in this paper which presents a numerical study of several trailing edge cooling configurations based on the placement of ribs at different walls. The baseline geometries are two-pass trapezoidal channels with and without orthogonal ribs at the bottom surface of the channel. Ribs induce secondary flow which results in enhancement of heat transfer; therefore, for enhancement of heat transfer at the trailing edge, ribs are placed at the trailing edge surface in three different configurations: first without ribs at the bottom surface, then ribs at the trailing edge surface in-line with the ribs at the bottom surface, and finally staggered ribs. Heat transfer and pressure drop is calculated at Reynolds number equal to 9400 for all configurations. Different turbulent models are used for the validation of the numerical results. For the smooth channel low-Re k-ɛ model, realizable k-ɛ model, the RNG k-ω model, low-Re k-ω model, and SST k-ω models are compared, whereas for ribbed channel, low-Re k-ɛ model and SST k-ω models are compared. The results show that the low-Re k-ɛ model, which predicts the heat transfer in outlet pass of the smooth channels with difference of +7%, underpredicts the heat transfer by -17% in case of ribbed channel compared to

  16. Investigation on flow and heat transfer characteristics in rectangular channel with drop-shaped pin fins

    Directory of Open Access Journals (Sweden)

    Fengming Wang

    2012-12-01

    Full Text Available The flow and heat transfer characteristics inside a rectangular channel embedded with pin fins were numerically and experimentally investigated. Several differently shaped pin fins (i.e., circular, elliptical, and drop-shaped with the same cross-sectional areas were compared in a staggered arrangement. The Reynolds number based on the obstructed section hydraulic diameter (defined as the ratio of the total wetted surface area to the open duct volume available for flow was varied from 4800 to 8200. The more streamlined drop-shaped pin fins were better at delaying or suppressing separation of the flow passing through them, which decreased the aerodynamic penalty compared to circular pin fins. The heat transfer enhancement of the drop-shaped pin fins was less than that of the circular pin fins. In terms of specific performance parameters, drop-shaped pin fins are a promising alternative configuration to circular pin fins.

  17. Coherifying quantum channels

    Science.gov (United States)

    Korzekwa, Kamil; Czachórski, Stanisław; Puchała, Zbigniew; Życzkowski, Karol

    2018-04-01

    Is it always possible to explain random stochastic transitions between states of a finite-dimensional system as arising from the deterministic quantum evolution of the system? If not, then what is the minimal amount of randomness required by quantum theory to explain a given stochastic process? Here, we address this problem by studying possible coherifications of a quantum channel Φ, i.e., we look for channels {{{Φ }}}{ \\mathcal C } that induce the same classical transitions T, but are ‘more coherent’. To quantify the coherence of a channel Φ we measure the coherence of the corresponding Jamiołkowski state J Φ. We show that the classical transition matrix T can be coherified to reversible unitary dynamics if and only if T is unistochastic. Otherwise the Jamiołkowski state {J}{{Φ }}{ \\mathcal C } of the optimally coherified channel is mixed, and the dynamics must necessarily be irreversible. To assess the extent to which an optimal process {{{Φ }}}{ \\mathcal C } is indeterministic we find explicit bounds on the entropy and purity of {J}{{Φ }}{ \\mathcal C }, and relate the latter to the unitarity of {{{Φ }}}{ \\mathcal C }. We also find optimal coherifications for several classes of channels, including all one-qubit channels. Finally, we provide a non-optimal coherification procedure that works for an arbitrary channel Φ and reduces its rank (the minimal number of required Kraus operators) from {d}2 to d.

  18. Evaluation channel performance in multichannel environments

    NARCIS (Netherlands)

    Gensler, S.; Dekimpe, M.; Skiera, B.

    2007-01-01

    Evaluating channel performance is crucial for actively managing multiple sales channels, and requires understanding the customers' channel preferences. Two key components of channel performance are (i) the existing customers' intrinsic loyalty to a particular channel and (ii) the channel's ability

  19. Fractional channel multichannel analyzer

    Science.gov (United States)

    Brackenbush, L.W.; Anderson, G.A.

    1994-08-23

    A multichannel analyzer incorporating the features of the present invention obtains the effect of fractional channels thus greatly reducing the number of actual channels necessary to record complex line spectra. This is accomplished by using an analog-to-digital converter in the asynchronous mode, i.e., the gate pulse from the pulse height-to-pulse width converter is not synchronized with the signal from a clock oscillator. This saves power and reduces the number of components required on the board to achieve the effect of radically expanding the number of channels without changing the circuit board. 9 figs.

  20. Cl- channels in apoptosis

    DEFF Research Database (Denmark)

    Wanitchakool, Podchanart; Ousingsawat, Jiraporn; Sirianant, Lalida

    2016-01-01

    A remarkable feature of apoptosis is the initial massive cell shrinkage, which requires opening of ion channels to allow release of K(+), Cl(-), and organic osmolytes to drive osmotic water movement and cell shrinkage. This article focuses on the role of the Cl(-) channels LRRC8, TMEM16/anoctamin......, and cystic fibrosis transmembrane conductance regulator (CFTR) in cellular apoptosis. LRRC8A-E has been identified as a volume-regulated anion channel expressed in many cell types. It was shown to be required for regulatory and apoptotic volume decrease (RVD, AVD) in cultured cell lines. Its presence also...

  1. Direct channel problems and phenomena

    International Nuclear Information System (INIS)

    Cutkosky, R.E.

    1975-01-01

    Direct channel problems and phenomena are considered covering the need for precision hadron spectroscopy, the data base for precision hadron spectroscopy, some relations between direct-channel and cross-channel effects, and spin rotation phenomena

  2. Channel Choice: A Literature Review

    DEFF Research Database (Denmark)

    Østergaard Madsen, Christian; Kræmmergaard, Pernille

    2015-01-01

    The channel choice branch of e-government studies citizens’ and businesses’ choice of channels for interacting with government, and how government organizations can integrate channels and migrate users towards the most cost-efficient channels. In spite of the valuable contributions offered no sys...... no systematic overview exist of channel choice. We present a literature review of channel choice studies in government to citizen context identifying authors, countries, methods, concepts, units of analysis, and theories, and offer suggestionsfor future studies....

  3. Volume Regulated Channels

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjær

    , controlled cell death and cellular migration. Volume regulatory mechanisms has long been in focus for regulating cellular proliferation and my thesis work have been focusing on the role of Cl- channels in proliferation with specific emphasis on ICl, swell. Pharmacological blockage of the ubiquitously...... but are also essential for a number of physiological processes such as proliferation, controlled cell death, migration and endocrinology. The thesis have been focusing on two Channels, namely the swelling activated Cl- channel (ICl, swell) and the transient receptor potential Vanilloid (TRPV4) channel. I: Cl...... understood. Potential agonist binding sites have been proposed in transmembrane domains 3 and 4, in congruence with agonist binding sites of TRPV1. However, the functional relationship between TRPV4 and agonist binding is not yet understood. In this thesis is further elaborate the structure...

  4. Sensing with Ion Channels

    CERN Document Server

    Martinac, Boris

    2008-01-01

    All living cells are able to detect and translate environmental stimuli into biologically meaningful signals. Sensations of touch, hearing, sight, taste, smell or pain are essential to the survival of all living organisms. The importance of sensory input for the existence of life thus justifies the effort made to understand its molecular origins. Sensing with Ion Channels focuses on ion channels as key molecules enabling biological systems to sense and process the physical and chemical stimuli that act upon cells in their living environment. Its aim is to serve as a reference to ion channel specialists and as a source of new information to non specialists who want to learn about the structural and functional diversity of ion channels and their role in sensory physiology.

  5. Calcium channel blocker poisoning

    Directory of Open Access Journals (Sweden)

    Miran Brvar

    2005-04-01

    Full Text Available Background: Calcium channel blockers act at L-type calcium channels in cardiac and vascular smooth muscles by preventing calcium influx into cells with resultant decrease in vascular tone and cardiac inotropy, chronotropy and dromotropy. Poisoning with calcium channel blockers results in reduced cardiac output, bradycardia, atrioventricular block, hypotension and shock. The findings of hypotension and bradycardia should suggest poisoning with calcium channel blockers.Conclusions: Treatment includes immediate gastric lavage and whole-bowel irrigation in case of ingestion of sustainedrelease products. All patients should receive an activated charcoal orally. Specific treatment includes calcium, glucagone and insulin, which proved especially useful in shocked patients. Supportive care including the use of catecholamines is not always effective. In the setting of failure of pharmacological therapy transvenous pacing, balloon pump and cardiopulmonary by-pass may be necessary.

  6. Coding for optical channels

    CERN Document Server

    Djordjevic, Ivan; Vasic, Bane

    2010-01-01

    This unique book provides a coherent and comprehensive introduction to the fundamentals of optical communications, signal processing and coding for optical channels. It is the first to integrate the fundamentals of coding theory and optical communication.

  7. Tritium in the Channel

    International Nuclear Information System (INIS)

    Masson, M.; Fievet, B.; Bailly-Du-Bois, P.; Olivier, A.; Tenailleau, L.

    2009-01-01

    After having recalled that sea waters entering the Channel exhibit a natural concentration of tritium, the authors outline that spent nuclear fuel reprocessing plants are now the main sources of tritium for marine ecosystems as some oceanographic campaigns showed it. If data about the presence of tritium in water are numerous, data concerning the presence of tritiated water and of organically bound tritium in organisms are much less frequent. However, some surveys have been performed along the Channel French coasts

  8. Channelling versus inversion

    DEFF Research Database (Denmark)

    Gale, A.S.; Surlyk, Finn; Anderskouv, Kresten

    2013-01-01

    Evidence from regional stratigraphical patterns in Santonian−Campanian chalk is used to infer the presence of a very broad channel system (5 km across) with a depth of at least 50 m, running NNW−SSE across the eastern Isle of Wight; only the western part of the channel wall and fill is exposed. W......−Campanian chalks in the eastern Isle of Wight, involving penecontemporaneous tectonic inversion of the underlying basement structure, are rejected....

  9. Numerical Simulation of Density Current Evolution in a Diverging Channel

    Directory of Open Access Journals (Sweden)

    Mitra Javan

    2012-01-01

    Full Text Available When a buoyant inflow of higher density enters a reservoir, it sinks below the ambient water and forms an underflow. Downstream of the plunge point, the flow becomes progressively diluted due to the fluid entrainment. This study seeks to explore the ability of 2D width-averaged unsteady Reynolds-averaged Navier-Stokes (RANS simulation approach for resolving density currents in an inclined diverging channel. 2D width-averaged unsteady RANS equations closed by a buoyancy-modified − turbulence model are integrated in time with a second-order fractional step approach coupled with a direct implicit method and discretized in space on a staggered mesh using a second-order accurate finite volume approach incorporating a high-resolution semi-Lagrangian technique for the convective terms. A series of 2D width-averaged unsteady simulations is carried out for density currents. Comparisons with the experimental measurements and the other numerical simulations show that the predictions of velocity and density field are with reasonable accuracy.

  10. Course on Ionic Channels

    CERN Document Server

    1986-01-01

    This book is based on a series of lectures for a course on ionic channels held in Santiago, Chile, on November 17-20, 1984. It is intended as a tutorial guide on the properties, function, modulation, and reconstitution of ionic channels, and it should be accessible to graduate students taking their first steps in this field. In the presentation there has been a deliberate emphasis on the spe­ cific methodologies used toward the understanding of the workings and function of channels. Thus, in the first section, we learn to "read" single­ channel records: how to interpret them in the theoretical frame of kinetic models, which information can be extracted from gating currents in re­ lation to the closing and opening processes, and how ion transport through an open channel can be explained in terms of fluctuating energy barriers. The importance of assessing unequivocally the origin and purity of mem­ brane preparations and the use of membrane vesicles and optical tech­ niques in the stUGY of ionic channels a...

  11. A Randomized controlled trial on safety and efficacy of single intramuscular versus staggered oral dose of 600 000IU Vitamin D in treatment of nutritional rickets.

    Science.gov (United States)

    Mondal, Krishanu; Seth, Anju; Marwaha, Raman K; Dhanwal, Dinesh; Aneja, Satinder; Singh, Ritu; Sonkar, Pitambar

    2014-06-01

    Comparison of efficacy and safety of two different regimens of vitamin D-600 000 IU as a single intramuscular dose, and 60 000IU orally once a week for 10 weeks-in treatment of nutritional rickets. Children with nutritional rickets (age: 0.5-5 years, n = 61) were randomized to receive either 60 000IU vitamin D orally once a week for 10 weeks or 600 000IU single intramuscular injection. Serum calcium, phosphate, alkaline phosphatase, urinary calcium/creatinine ratio, serum 25 hydroxy vitamin D and radiological score were compared at 12-week follow-up. No difference was found in efficacy of the two regimens on comparing biochemical and radiological parameters. Serum 25 hydroxy vitamin D >100 ng/ml was found in two children in the oral group and one child in the intramuscular group. No child developed hypercalcemia or hypercalciuria after starting treatment. Staggered oral and one-time intramuscular administrations of 600 000IU vitamin D are equally effective and safe in treatment of nutritional rickets. © The Author [2014]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. A Newton-Krylov method with approximate Jacobian for implicit solution of Navier-Stokes on staggered overset-curvilinear grids with immersed boundaries

    Science.gov (United States)

    Asgharzadeh, Hafez; Borazjani, Iman

    2014-11-01

    Time step-size restrictions and low convergence rates are major bottle necks for implicit solution of the Navier-Stokes in simulations involving complex geometries with moving boundaries. Newton-Krylov method (NKM) is a combination of a Newton-type method for super-linearly convergent solution of nonlinear equations and Krylov subspace methods for solving the Newton correction equations, which can theoretically address both bottle necks. The efficiency of this method vastly depends on the Jacobian forming scheme e.g. automatic differentiation is very expensive and Jacobian-free methods slow down as the mesh is refined. A novel, computationally efficient analytical Jacobian for NKM was developed to solve unsteady incompressible Navier-Stokes momentum equations on staggered curvilinear grids with immersed boundaries. The NKM was validated and verified against Taylor-Green vortex and pulsatile flow in a 90 degree bend and efficiently handles complex geometries such as an intracranial aneurysm with multiple overset grids, pulsatile inlet flow and immersed boundaries. The NKM method is shown to be more efficient than the semi-implicit Runge-Kutta methods and Jabobian-free Newton-Krylov methods. We believe NKM can be applied to many CFD techniques to decrease the computational cost. This work was supported partly by the NIH Grant R03EB014860, and the computational resources were partly provided by Center for Computational Research (CCR) at University at Buffalo.

  13. Classification for the universal scaling of Néel temperature and staggered magnetization density of three-dimensional dimerized spin-1/2 antiferromagnets

    Science.gov (United States)

    Tan, D.-R.; Li, C.-D.; Jiang, F.-J.

    2018-03-01

    Inspired by the recent theoretical development relevant to the experimental data of TlCuCl3, particularly those associated with the universal scaling between the Néel temperature TN and the staggered magnetization density Ms, we carry out a detailed investigation of three-dimensional (3D) dimerized quantum antiferromagnets using the first-principles quantum Monte Carlo calculations. Through this study we wish to better understand the microscopic effects on these scaling relations of TN and Ms, hence to shed light on some of the observed inconsistency between the theoretical and the experimental results. Remarkably, for the considered 3D dimerized models, we find that the established universal scaling relations are not only valid, but can each be categorized within its kind by the amount of stronger antiferromagnetic couplings connected to each spin. Convincing numerical evidence is provided to support the validity of this classification scheme. Based on all the related results known in the literature, we further argue that the proposed categorization for the universal scaling investigated in our paper should be applicable for 3D dimerized spin systems with (certain kinds of) quenched disorder and (or) on lattice geometries other than those considered here. The relevance of the outcomes presented in this investigation to the experiments of TlCuCl3 is briefly discussed as well.

  14. Solving phase appearance/disappearance two-phase flow problems with high resolution staggered grid and fully implicit schemes by the Jacobian-free Newton–Krylov Method

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Ling; Zhao, Haihua; Zhang, Hongbin

    2016-04-01

    The phase appearance/disappearance issue presents serious numerical challenges in two-phase flow simulations. Many existing reactor safety analysis codes use different kinds of treatments for the phase appearance/disappearance problem. However, to our best knowledge, there are no fully satisfactory solutions. Additionally, the majority of the existing reactor system analysis codes were developed using low-order numerical schemes in both space and time. In many situations, it is desirable to use high-resolution spatial discretization and fully implicit time integration schemes to reduce numerical errors. In this work, we adapted a high-resolution spatial discretization scheme on staggered grid mesh and fully implicit time integration methods (such as BDF1 and BDF2) to solve the two-phase flow problems. The discretized nonlinear system was solved by the Jacobian-free Newton Krylov (JFNK) method, which does not require the derivation and implementation of analytical Jacobian matrix. These methods were tested with a few two-phase flow problems with phase appearance/disappearance phenomena considered, such as a linear advection problem, an oscillating manometer problem, and a sedimentation problem. The JFNK method demonstrated extremely robust and stable behaviors in solving the two-phase flow problems with phase appearance/disappearance. No special treatments such as water level tracking or void fraction limiting were used. High-resolution spatial discretization and second- order fully implicit method also demonstrated their capabilities in significantly reducing numerical errors.

  15. adequacy of drainage channels f drainage channels in a small

    African Journals Online (AJOL)

    eobe

    carried out and data obtain from drainage channels. The time of concentratio version of version of Kirpich equation (new equation of time new equation of time from the drainage channels were determined using results showed that most of the drainage channels h. All the drainage channels of basin A had velocities ra.

  16. Ion channelling in diamond

    International Nuclear Information System (INIS)

    Derry, T.E.

    1978-06-01

    Diamond is one of the most extreme cases from a channelling point of view, having the smallest thermal vibration amplitude and the lowest atomic number of commonly-encountered crystals. These are the two parameters most important for determining channelling behaviour. It is of consiberable interest therefore to see how well the theories explaining and predicting the channeling properties of other substance, succeed with diamond. Natural diamond, although the best available form for these experiments, is rather variable in its physical properties. Part of the project was devoted to considering and solving the problem of obtaining reproducible results representative of the ideal crystal. Channelling studies were performed on several good crystals, using the Rutherford backscattering method. Critical angles for proton channelling were measured for incident energies from 0.6 to 4.5 MeV, in the three most open axes and three most open planes of the diamond structure, and for α-particle channelling at 0.7 and 1.0 MeV (He + ) in the same axes and planes. For 1.0 MeV protons, the crystal temperature was varied from 20 degrees Celsius to 700 degrees Celsius. The results are presented as curves of backscattered yield versus angle in the region of each axis or plane, and summarised in the form of tables and graphs. Generally the critical angles, axial minimum yields, and temperature dependence are well predicted by the accepted theories. The most valuable overall conclusion is that the mean thermal vibration amplitude of the atoms in a crytical determines the critical approach distance to the channel walls at which an ion can remain channelled, even when this distance is much smaller than the Thomas-Fermi screening distance of the atomic potential, as is the case in diamond. A brief study was made of the radiation damage caused by α-particle bombardment, via its effect on the channelling phenomenon. It was possible to hold damage down to negligible levels during the

  17. Channel identification machines.

    Science.gov (United States)

    Lazar, Aurel A; Slutskiy, Yevgeniy B

    2012-01-01

    We present a formal methodology for identifying a channel in a system consisting of a communication channel in cascade with an asynchronous sampler. The channel is modeled as a multidimensional filter, while models of asynchronous samplers are taken from neuroscience and communications and include integrate-and-fire neurons, asynchronous sigma/delta modulators and general oscillators in cascade with zero-crossing detectors. We devise channel identification algorithms that recover a projection of the filter(s) onto a space of input signals loss-free for both scalar and vector-valued test signals. The test signals are modeled as elements of a reproducing kernel Hilbert space (RKHS) with a Dirichlet kernel. Under appropriate limiting conditions on the bandwidth and the order of the test signal space, the filter projection converges to the impulse response of the filter. We show that our results hold for a wide class of RKHSs, including the space of finite-energy bandlimited signals. We also extend our channel identification results to noisy circuits.

  18. Channel Identification Machines

    Directory of Open Access Journals (Sweden)

    Aurel A. Lazar

    2012-01-01

    Full Text Available We present a formal methodology for identifying a channel in a system consisting of a communication channel in cascade with an asynchronous sampler. The channel is modeled as a multidimensional filter, while models of asynchronous samplers are taken from neuroscience and communications and include integrate-and-fire neurons, asynchronous sigma/delta modulators and general oscillators in cascade with zero-crossing detectors. We devise channel identification algorithms that recover a projection of the filter(s onto a space of input signals loss-free for both scalar and vector-valued test signals. The test signals are modeled as elements of a reproducing kernel Hilbert space (RKHS with a Dirichlet kernel. Under appropriate limiting conditions on the bandwidth and the order of the test signal space, the filter projection converges to the impulse response of the filter. We show that our results hold for a wide class of RKHSs, including the space of finite-energy bandlimited signals. We also extend our channel identification results to noisy circuits.

  19. Channel plate for DNA sequencing

    Science.gov (United States)

    Douthart, Richard J.; Crowell, Shannon L.

    1998-01-01

    This invention is a channel plate that facilitates data compaction in DNA sequencing. The channel plate has a length, a width and a thickness, and further has a plurality of channels that are parallel. Each channel has a depth partially through the thickness of the channel plate. Additionally an interface edge permits electrical communication across an interface through a buffer to a deposition membrane surface.

  20. Nanoscale Vacuum Channel Transistor.

    Science.gov (United States)

    Han, Jin-Woo; Moon, Dong-Il; Meyyappan, M

    2017-04-12

    Vacuum tubes that sparked the electronics era had given way to semiconductor transistors. Despite their faster operation and better immunity to noise and radiation compared to the transistors, the vacuum device technology became extinct due to the high power consumption, integration difficulties, and short lifetime of the vacuum tubes. We combine the best of vacuum tubes and modern silicon nanofabrication technology here. The surround gate nanoscale vacuum channel transistor consists of sharp source and drain electrodes separated by sub-50 nm vacuum channel with a source to gate distance of 10 nm. This transistor performs at a low voltage (3 microamperes). The nanoscale vacuum channel transistor can be a possible alternative to semiconductor transistors beyond Moore's law.

  1. Chaos in quantum channels

    Science.gov (United States)

    Hosur, Pavan; Qi, Xiao-Liang; Roberts, Daniel A.; Yoshida, Beni

    2016-02-01

    We study chaos and scrambling in unitary channels by considering their entanglement properties as states. Using out-of-time-order correlation functions to diagnose chaos, we characterize the ability of a channel to process quantum information. We show that the generic decay of such correlators implies that any input subsystem must have near vanishing mutual information with almost all partitions of the output. Additionally, we propose the negativity of the tripartite information of the channel as a general diagnostic of scrambling. This measures the delocalization of information and is closely related to the decay of out-of-time-order correlators. We back up our results with numerics in two non-integrable models and analytic results in a perfect tensor network model of chaotic time evolution. These results show that the butterfly effect in quantum systems implies the information-theoretic definition of scrambling.

  2. CANDU fuel channels

    International Nuclear Information System (INIS)

    Coleman, C.E.; Cheadle, B.A.

    1997-01-01

    The service life of CANDU fuel channels is determined by the component that has to withstand the most severe conditions, the Zr-2.5Nb pressure tube. The latest fuel channels are expected to have a lifetime of over 30 years. The properties that control service life are fracture and deformation. For fracture, a defence-in-depth approach is used - preventing crack initiation and invoking leak-before-break. Confidence in the serviceability of fuel channels is based on current knowledge of the state of health of the components evaluated by surveillance. Degradation of properties with service is slow, allowing sufficient time to judge and act when end-of-life is reached. Methods for improving the properties of components are outlined. (author)

  3. Phenacyl-thiophene and quinone semiconductors designed for solution processability and air-stability in high mobility n-channel field-effect transistors.

    Science.gov (United States)

    Letizia, Joseph A; Cronin, Scott; Ortiz, Rocio Ponce; Facchetti, Antonio; Ratner, Mark A; Marks, Tobin J

    2010-02-08

    Electron-transporting organic semiconductors (n-channel) for field-effect transistors (FETs) that are processable in common organic solvents or exhibit air-stable operation are rare. This investigation addresses both these challenges through rational molecular design and computational predictions of n-channel FET air-stability. A series of seven phenacyl-thiophene-based materials are reported incorporating systematic variations in molecular structure and reduction potential. These compounds are as follows: 5,5'''-bis(perfluorophenylcarbonyl)-2,2':5',- 2'':5'',2'''-quaterthiophene (1), 5,5'''-bis(phenacyl)-2,2':5',2'': 5'',2'''-quaterthiophene (2), poly[5,5'''-(perfluorophenac-2-yl)-4',4''-dioctyl-2,2':5',2'':5'',2'''-quaterthiophene) (3), 5,5'''-bis(perfluorophenacyl)-4,4'''-dioctyl-2,2':5',2'':5'',2'''-quaterthiophene (4), 2,7-bis((5-perfluorophenacyl)thiophen-2-yl)-9,10-phenanthrenequinone (5), 2,7-bis[(5-phenacyl)thiophen-2-yl]-9,10-phenanthrenequinone (6), and 2,7-bis(thiophen-2-yl)-9,10-phenanthrenequinone, (7). Optical and electrochemical data reveal that phenacyl functionalization significantly depresses the LUMO energies, and introduction of the quinone fragment results in even greater LUMO stabilization. FET measurements reveal that the films of materials 1, 3, 5, and 6 exhibit n-channel activity. Notably, oligomer 1 exhibits one of the highest mu(e) (up to approximately = 0.3 cm(2) V(-1) s(-1)) values reported to date for a solution-cast organic semiconductor; one of the first n-channel polymers, 3, exhibits mu(e) approximately = 10(-6) cm(2) V(-1) s(-1) in spin-cast films (mu(e)=0.02 cm(2) V(-1) s(-1) for drop-cast 1:3 blend films); and rare air-stable n-channel material 5 exhibits n-channel FET operation with mu(e)=0.015 cm(2) V(-1) s(-1), while maintaining a large I(on:off)=10(6) for a period greater than one year in air. The crystal structures of 1 and 2 reveal close herringbone interplanar pi-stacking distances (3.50 and 3.43 A, respectively

  4. MITOCHONDRIAL BKCa CHANNEL

    Directory of Open Access Journals (Sweden)

    Enrique eBalderas

    2015-03-01

    Full Text Available Since its discovery in a glioma cell line 15 years ago, mitochondrial BKCa channel (mitoBKCa has been studied in brain cells and cardiomyocytes sharing general biophysical properties such as high K+ conductance (~300 pS, voltage-dependency and Ca2+-sensitivity. Main advances in deciphering the molecular composition of mitoBKCa have included establishing that it is encoded by the Kcnma1 gene, that a C-terminal splice insert confers mitoBKCa ability to be targeted to cardiac mitochondria, and evidence for its potential coassembly with β subunits. Notoriously, β1 subunit directly interacts with cytochrome c oxidase and mitoBKCa can be modulated by substrates of the respiratory chain. mitoBKCa channel has a central role in protecting the heart from ischemia, where pharmacological activation of the channel impacts the generation of reactive oxygen species and mitochondrial Ca2+ preventing cell death likely by impeding uncontrolled opening of the mitochondrial transition pore. Supporting this view, inhibition of mitoBKCa with Iberiotoxin, enhances cytochrome c release from glioma mitochondria. Many tantalizing questions remain. Some of them are: how is mitoBKCa coupled to the respiratory chain? Does mitoBKCa play non-conduction roles in mitochondria physiology? Which are the functional partners of mitoBKCa? What are the roles of mitoBKCa in other cell types? Answers to these questions are essential to define the impact of mitoBKCa channel in mitochondria biology and disease.

  5. Channels of Propaganda.

    Science.gov (United States)

    Sproule, J. Michael

    Defining propaganda as "efforts by special interests to win over the public covertly by infiltrating messages into various channels of public expression ordinarily viewed as politically neutral," this book argues that propaganda has become pervasive in American life. Pointing out that the 1990s society is inundated with propaganda from…

  6. Chemistry in Microfluidic Channels

    Science.gov (United States)

    Chia, Matthew C.; Sweeney, Christina M.; Odom, Teri W.

    2011-01-01

    General chemistry introduces principles such as acid-base chemistry, mixing, and precipitation that are usually demonstrated in bulk solutions. In this laboratory experiment, we describe how chemical reactions can be performed in a microfluidic channel to show advanced concepts such as laminar fluid flow and controlled precipitation. Three sets of…

  7. Channeling through Bent Crystals

    Energy Technology Data Exchange (ETDEWEB)

    Mack, Stephanie; /Ottawa U. /SLAC

    2012-09-07

    Bent crystals have demonstrated potential for use in beam collimation. A process called channeling is when accelerated particle beams are trapped by the nuclear potentials in the atomic planes within a crystal lattice. If the crystal is bent then the particles can follow the bending angle of the crystal. There are several different effects that are observed when particles travel through a bent crystal including dechanneling, volume capture, volume reflection and channeling. With a crystal placed at the edge of a particle beam, part of the fringe of the beam can be deflected away towards a detector or beam dump, thus helping collimate the beam. There is currently FORTRAN code by Igor Yazynin that has been used to model the passage of particles through a bent crystal. Using this code, the effects mentioned were explored for beam energy that would be seen at the Facility for Advanced Accelerator Experimental Tests (FACET) at a range of crystal orientations with respect to the incoming beam. After propagating 5 meters in vacuum space past the crystal the channeled particles were observed to separate from most of the beam with some noise due to dechanneled particles. Progressively smaller bending radii, with corresponding shorter crystal lengths, were compared and it was seen that multiple scattering decreases with the length of the crystal therefore allowing for cleaner detection of the channeled particles. The input beam was then modified and only a portion of the beam sent through the crystal. With the majority of the beam not affected by the crystal, most particles were not deflected and after propagation the channeled particles were seen to be deflected approximately 5mm. After a portion of the beam travels through the crystal, the entire beam was then sent through a quadrupole magnet, which increased the separation of the channeled particles from the remainder of the beam to a distance of around 20mm. A different code, which was developed at SLAC, was used to

  8. Quantum communication under channel uncertainty

    International Nuclear Information System (INIS)

    Noetzel, Janis Christian Gregor

    2012-01-01

    This work contains results concerning transmission of entanglement and subspaces as well as generation of entanglement in the limit of arbitrary many uses of compound- and arbitrarily varying quantum channels (CQC, AVQC). In both cases, the channel is described by a set of memoryless channels. Only forward communication between one sender and one receiver is allowed. A code is said to be ''good'' only, if it is ''good'' for every channel out of the set. Both settings describe a scenario, in which sender and receiver have only limited channel knowledge. For different amounts of information about the channel available to sender or receiver, coding theorems are proven for the CQC. For the AVQC, both deterministic and randomised coding schemes are considered. Coding theorems are proven, as well as a quantum analogue of the Ahlswede-dichotomy. The connection to zero-error capacities of stationary memoryless quantum channels is investigated. The notion of symmetrisability is defined and used for both classes of channels.

  9. Learning Channels and Verbal Behavior

    Science.gov (United States)

    Lin, Fan-Yu; Kubina, Richard M., Jr.

    2004-01-01

    This article reviews the basics of learning channels and how specification of stimuli can help enhance verbal behavior. This article will define learning channels and the role of the ability matrix in training verbal behavior.

  10. The StaggerGrid project

    DEFF Research Database (Denmark)

    Collet, Remo; Magic, Zazralt; Asplund, Martin

    2011-01-01

    In this contribution, we present the STAGGERGRID, a collaborative project for the construction of a comprehensive grid of time-dependent, three-dimensional (3-D), hydrodynamic model atmospheres of solar- and late-type stars with different effective temperatures, surface gravities, and chemical...

  11. Joint synthetic aperture radar plus ground moving target indicator from single-channel radar using compressive sensing

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Douglas; Hallquist, Aaron; Anderson, Hyrum

    2017-10-17

    The various embodiments presented herein relate to utilizing an operational single-channel radar to collect and process synthetic aperture radar (SAR) and ground moving target indicator (GMTI) imagery from a same set of radar returns. In an embodiment, data is collected by randomly staggering a slow-time pulse repetition interval (PRI) over a SAR aperture such that a number of transmitted pulses in the SAR aperture is preserved with respect to standard SAR, but many of the pulses are spaced very closely enabling movers (e.g., targets) to be resolved, wherein a relative velocity of the movers places them outside of the SAR ground patch. The various embodiments of image reconstruction can be based on compressed sensing inversion from undersampled data, which can be solved efficiently using such techniques as Bregman iteration. The various embodiments enable high-quality SAR reconstruction, and high-quality GMTI reconstruction from the same set of radar returns.

  12. ``Just Another Distribution Channel?''

    Science.gov (United States)

    Lemstra, Wolter; de Leeuw, Gerd-Jan; van de Kar, Els; Brand, Paul

    The telecommunications-centric business model of mobile operators is under attack due to technological convergence in the communication and content industries. This has resulted in a plethora of academic contributions on the design of new business models and service platform architectures. However, a discussion of the challenges that operators are facing in adopting these models is lacking. We assess these challenges by considering the mobile network as part of the value system of the content industry. We will argue that from the perspective of a content provider the mobile network is ‘just another’ distribution channel. Strategic options available for the mobile communication operators are to deliver an excellent distribution channel for content delivery or to move upwards in the value chain by becoming a content aggregator. To become a mobile content aggregator operators will have to develop or acquire complementary resources and capabilities. Whether this strategic option is sustainable remains open.

  13. Geysering in boiling channels

    Energy Technology Data Exchange (ETDEWEB)

    Aritomi, Masanori; Takemoto, Takatoshi [Tokyo Institute of Technology, Tokyo (Japan); Chiang, Jing-Hsien [Japan NUS Corp. Ltd., Toyko (Japan)] [and others

    1995-09-01

    A concept of natural circulation BWRs such as the SBWR has been proposed and seems to be promising in that the primary cooling system can be simplified. The authors have been investigating thermo-hydraulic instabilities which may appear during the start-up in natural circulation BWRs. In our previous works, geysering was investigated in parallel boiling channels for both natural and forced circulations, and its driving mechanism and the effect of system pressure on geysering occurrence were made clear. In this paper, geysering is investigated in a vertical column and a U-shaped vertical column heated in the lower parts. It is clarified from the results that the occurrence mechanism of geysering and the dependence of system pressure on geysering occurrence coincide between parallel boiling channels in circulation systems and vertical columns in non-circulation systems.

  14. Radar channel balancing with commutation

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2014-02-01

    When multiple channels are employed in a pulse-Doppler radar, achieving and maintaining balance between the channels is problematic. In some circumstances the channels may be commutated to achieve adequate balance. Commutation is the switching, trading, toggling, or multiplexing of the channels between signal paths. Commutation allows modulating the imbalance energy away from the balanced energy in Doppler, where it can be mitigated with filtering.

  15. Nuclear reactor coolant channels

    International Nuclear Information System (INIS)

    Macbeth, R.V.

    1978-01-01

    A nuclear reactor coolant channel is described that is suitable for sub-cooled reactors as in pressurised water reactors as well as for bulk boiling, as in boiling water reactors and steam generating nuclear reactors. The arrangement aims to improve heat transfer between the fuel elements and the coolant. Full constructional details are given. See also other similar patents by the author. (U.K.)

  16. Channel box compression device

    International Nuclear Information System (INIS)

    Nakamizo, Hiroshi; Tanaka, Yuki.

    1996-01-01

    The device of the present invention reduces the volume of spent fuel channel boxes of power plant facilities to eliminate secondary wastes, suppress generation of radiation sources and improve storage space efficiency. The device has a box-like shape. A support frame is disposed on the lateral side of the box for supporting spent channel boxes. A horizontal transferring unit and a vertical transferring compression unit driven by a driving mechanism are disposed in the support frame. Further, the compression unit may have a rotational compression roller so as to move freely in the transferring unit. In addition, the transferring unit and the driving mechanism may be disposed outside of pool water. With such a constitution, since spent channel boxes are compressed and bent by horizontal movement of the transferring unit and the vertical movement of the compression unit, no cut pieces or cut powders are generated. Further, if the transferring unit and the driving mechanism are disposed outside of the pool water, it is not necessary to make them waterproof, which facilitates the maintenance. (I.S.)

  17. Ion channeling revisited

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, Barney Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Corona, Aldo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nguyen, Anh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    A MS Excel program has been written that calculates accidental, or unintentional, ion channeling in cubic bcc, fcc and diamond lattice crystals or polycrystalline materials. This becomes an important issue when simulating the creation by energetic neutrons of point displacement damage and extended defects using beams of ions. All of the tables and graphs in the three Ion Beam Analysis Handbooks that previously had to be manually looked up and read from were programed into Excel in handy lookup tables, or parameterized, for the case of the graphs, using rather simple exponential functions with different powers of the argument. The program then offers an extremely convenient way to calculate axial and planar half-angles and minimum yield or dechanneling probabilities, effects on half-angles of amorphous overlayers, accidental channeling probabilities for randomly oriented crystals or crystallites, and finally a way to automatically generate stereographic projections of axial and planar channeling half-angles. The program can generate these projections and calculate these probabilities for axes and [hkl] planes up to (555).

  18. TRP channels in kidney disease.

    NARCIS (Netherlands)

    Hsu, Y.J.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2007-01-01

    Mammalian TRP channel proteins form six-transmembrane cation-permeable channels that may be grouped into six subfamilies on the basis of amino acid sequence homology (TRPC, TRPV, TRPM, TRPA, TRPP, and TRPML). Recent studies of TRP channels indicate that they are involved in numerous fundamental cell

  19. The STAGGER-grid: A grid of 3D stellar atmosphere models. V. Synthetic stellar spectra and broad-band photometry

    Science.gov (United States)

    Chiavassa, A.; Casagrande, L.; Collet, R.; Magic, Z.; Bigot, L.; Thévenin, F.; Asplund, M.

    2018-03-01

    Context. The surface structures and dynamics of cool stars are characterised by the presence of convective motions and turbulent flows which shape the emergent spectrum. Aims: We used realistic three-dimensional (3D) radiative hydrodynamical simulations from the STAGGER-grid to calculate synthetic spectra with the radiative transfer code OPTIM3D for stars with different stellar parameters to predict photometric colours and convective velocity shifts. Methods: We calculated spectra from 1000 to 200 000 Å with a constant resolving power of λ/Δλ = 20 000 and from 8470 and 8710 Å (Gaia Radial Velocity Spectrometer - RVS - spectral range) with a constant resolving power of λ/Δλ = 300 000. Results: We used synthetic spectra to compute theoretical colours in the Johnson-Cousins UBV (RI)C, SDSS, 2MASS, Gaia, SkyMapper, Strömgren systems, and HST-WFC3. Our synthetic magnitudes are compared with those obtained using 1D hydrostatic models. We showed that 1D versus 3D differences are limited to a small percent except for the narrow filters that span the optical and UV region of the spectrum. In addition, we derived the effect of the convective velocity fields on selected Fe I lines. We found the overall convective shift for 3D simulations with respect to the reference 1D hydrostatic models, revealing line shifts of between -0.235 and +0.361 km s-1. We showed a net correlation of the convective shifts with the effective temperature: lower effective temperatures denote redshifts and higher effective temperatures denote blueshifts. We conclude that the extraction of accurate radial velocities from RVS spectra need an appropriate wavelength correction from convection shifts. Conclusions: The use of realistic 3D hydrodynamical stellar atmosphere simulations has a small but significant impact on the predicted photometry compared with classical 1D hydrostatic models for late-type stars. We make all the spectra publicly available for the community through the POLLUX database

  20. Intracellular ion channels and cancer

    Directory of Open Access Journals (Sweden)

    Luigi eLeanza

    2013-09-01

    Full Text Available Several types of channels play a role in the maintenance of ion homeostasis in subcellular organelles including endoplasmatic reticulum, nucleus, lysosome, endosome and mitochondria. Here we give a brief overview of the contribution of various mitochondrial and other organellar channels to cancer cell proliferation or death. Much attention is focused on channels involved in intracellular calcium signaling and on ion fluxes in the ATP-producing organelle mitochondria. Mitochondrial K+ channels (Ca2+-dependent BKCa and IKCa, ATP-dependent KATP, Kv1.3, two-pore TWIK-related Acid-Sensitive K+ channel-3 (TASK-3, Ca2+ uniporter MCU, Mg2+-permeable Mrs2, anion channels (voltage-dependent chloride channel VDAC, intracellular chloride channel CLIC and the Permeability Transition Pore (MPTP contribute importantly to the regulation of function in this organelle. Since mitochondria play a central role in apoptosis, modulation of their ion channels by pharmacological means may lead to death of cancer cells. The nuclear potassium channel Kv10.1 and the nuclear chloride channel CLIC4 as well as the endoplasmatic reticulum (ER-located inositol 1,4,5-trisphosphate (IP3 receptor, the ER-located Ca2+ depletion sensor STIM1 (stromal interaction molecule 1, a component of the store-operated Ca2+ channel and the ER-resident TRPM8 are also mentioned. Furthermore, pharmacological tools affecting organellar channels and modulating cancer cell survival are discussed. The channels described in this review are summarized on Figure 1. Overall, the view is emerging that intracellular ion channels may represent a promising target for cancer treatment.

  1. Planar channeling observed by radiography

    International Nuclear Information System (INIS)

    Delsarte, Guy

    1970-06-01

    Radiographies of crystals by means of channeled particles exhibit channeling patterns. The origin of these patterns is studied, The role played by planar channeling is demonstrated. It is shown that these patterns are local amplifications of the process generating the images of a crystal on the radiography. It is deduced that planar channeling plays a determining role in the formation of these images. An orientation chamber using transmitted planar channels is described. The orientation of very small grains in a polycrystal can be very easily obtained, (author) [fr

  2. Toward Eco-Friendly and Highly Efficient Solar Water Splitting Using In2S3/Anatase/Rutile TiO2Dual-Staggered-Heterojunction Nanodendrite Array Photoanode.

    Science.gov (United States)

    Yang, Jih-Sheng; Wu, Jih-Jen

    2018-01-31

    The TiO 2 -based heterojunction nanodendrite (ND) array composed of anatase nanoparticles (ANPs) on the surface of the rutile ND (RND) array is selected as the model photoanode to demonstrate the strategies toward eco-friendly and efficient solar water splitting using neutral electrolyte and seawater. Compared with the performances in alkaline electrolyte, a non-negligible potential drop across the electrolyte as well as impeded charge injection and charge separation is monitored in the ANP/RND array photoanode with neutral electrolyte, which are, respectively, ascribed to the series resistance of neutral electrolyte, the fundamentally pH-dependent water oxidation mechanism on TiO 2 surface, as well as the less band bending at the interface of TiO 2 and neutral electrolyte. Accordingly, a TiO 2 -based dual-staggered heterojunction ND array photoanode is further designed in this work to overcome the issue of less band bending with the neutral electrolyte. The improvement of charge separation efficiency is realized by the deposition of a transparent In 2 S 3 layer on the ANP/RND array photoanode for constructing additional staggered heterojunction. Under illumination of AM 1.5G (100 mW cm -2 ), the improved photocurrent densities acquired both in neutral electrolyte and seawater at 1.23 V vs reversible hydrogen electrode (RHE), which approach the theoretical value for rutile TiO 2 , are demonstrated in the dual-staggered-heterojunction ND array photoanode. Faradaic efficiencies of ∼95 and ∼32% for solar water oxidation in neutral electrolyte and solar seawater oxidation for 2 h are acquired at 1.23 V vs RHE, respectively.

  3. An Accounting Mechanism of the Protrusion Effect in the Annular Channel When Calculating the Leontiev Tube

    Directory of Open Access Journals (Sweden)

    N. A. Kiselev

    2017-01-01

    Full Text Available The paper analyses a technique to calculate the Leontiev tube and shows that there are several ways to increase operating efficiency of this device of gas-dynamic energy separation. Application of regular relief (dimples and protrusions on the wall between supersonic and subsonic channels is one of them.Analyses the results available in publications of experimentally numerically investigated influence of semi-spherical protrusions in the slot channels on the enhancement of heat transfer and drag coefficients at various Reynolds numbers.Shows that at the laminar flow owing to semi-spherical protrusions in the slot channel a heat transfer coefficient can be 1.1‑2.6 times increased with simultaneous 1.7‑4.8 times growth of drag coefficient (as compared to the smooth channel.At transition and turbulent flows the heat transfer enhancement, because of shallow dimples (depth-to-print diameter ratio is from 0.1 to 0.25, can reach 1.1‑2.4 times, with simultaneous 1.2‑7.9 times growth of the drag coefficient (as compared to smooth channel.Using the higher protrusions can provide up to 3.0‑3.5 times heat transfer intensification, but in this case there is an outrunning growth of the drag coefficient.It is shown that the staggered array of the shallow spherical protrusions is advisable to use for heat transfer enhancement in the subsonic channel of the Leontiev tube. The shallow spherical dimples correspond to them and operate as heat transfer intensifiers in the supersonic channel.The paper proposes a mechanism that enables taking into consideration an impact of the protrusions in the slot channel on the intensification of the heat transfer and momentum processes when calculating the gas-dynamic energy separation device (Leontiev tube using the known (earlier published technique.The study has been implemented under supporting Grant no. 15-08-08428 of the Russian Foundation for Basic Research.

  4. Heat transfer and pressure drop of supercritical carbon dioxide flowing in several printed circuit heat exchanger channel patterns

    International Nuclear Information System (INIS)

    Carlson, M.; Kruizenga, A.; Anderson, M.; Corradini, M.

    2012-01-01

    Closed-loop Brayton cycles using supercritical carbon dioxide (SCO 2 ) show potential for use in high-temperature power generation applications including High Temperature Gas Reactors (HTGR) and Sodium-Cooled Fast Reactors (SFR). Compared to Rankine cycles SCO 2 Brayton cycles offer similar or improved efficiency and the potential for decreased capital costs due to a reduction in equipment size and complexity. Compact printed-circuit heat exchangers (PCHE) are being considered as part of several SCO 2 Brayton designs to further reduce equipment size with increased energy density. Several designs plan to use a gas cooler operating near the pseudo-critical point of carbon dioxide to benefit from large variations in thermophysical properties, but further work is needed to validate correlations for heat transfer and pressure-drop characteristics of SCO 2 flows in candidate PCHE channel designs for a variety of operating conditions. This paper presents work on experimental measurements of the heat transfer and pressure drop behavior of miniature channels using carbon dioxide at supercritical pressure. Results from several plate geometries tested in horizontal cooling-mode flow are presented, including a straight semi-circular channel, zigzag channel with a bend angle of 80 degrees, and a channel with a staggered array of extruded airfoil pillars modeled after a NACA 0020 airfoil with an 8.1 mm chord length facing into the flow. Heat transfer coefficients and bulk temperatures are calculated from measured local wall temperatures and local heat fluxes. The experimental results are compared to several methods for estimating the friction factor and Nusselt number of cooling-mode flows at supercritical pressures in millimeter-scale channels. (authors)

  5. Channels in tokamak reactor shields

    International Nuclear Information System (INIS)

    Shchipakin, O.L.

    1981-01-01

    The results of calculations of neutron transport through the channels in the tokamak reactor radiation shields, obtained by the Monte Carlo method and by the method of discrete ordinates, are considered. The given data show that the structural materials of the channel and that of the blanket and shields in the regions close to it are subjected to almost the same irradiation as the first wall and therefore they should satisfy the technical requirements. The radiation energy release in the injector channel wall, caused by neutron shooting, substantially depends on the channel dimensions. At the channel large diameter (0.7-10 m) this dependence noticeably decreases. The investigation of the effect of the injector channel cross section form on the neutron flux density through the channel, testifies to weak dependence of shooting radiation intensity on the form of the channel cross section. It is concluded that measures to decrease unfavourable effect of the channels on the safety of the power tokamak reactor operation and maintenance cause substantial changes in reactor design due to which the channel protection must be developed at first stages. The Monte Carlo method is recommended to be used for variant calculations and when calculating the neutron flux functionals in specific points of the system the discrete ordinate method is preferred [ru

  6. Channel Wall Landslides

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] The multiple landslides in this VIS image occur along a steep channel wall. Note the large impact crater in the context image. The formation of the crater may have initially weakened that area of the surface prior to channel formation. Image information: VIS instrument. Latitude -2.7, Longitude 324.8 East (35.2 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  7. A Micromechanical RF Channelizer

    Science.gov (United States)

    Akgul, Mehmet

    The power consumption of a radio generally goes as the number and strength of the RF signals it must process. In particular, a radio receiver would consume much less power if the signal presented to its electronics contained only the desired signal in a tiny percent bandwidth frequency channel, rather than the typical mix of signals containing unwanted energy outside the desired channel. Unfortunately, a lack of filters capable of selecting single channel bandwidths at RF forces the front-ends of contemporary receivers to accept unwanted signals, and thus, to operate with sub-optimal efficiency. This dissertation focuses on the degree to which capacitive-gap transduced micromechanical resonators can achieve the aforementioned RF channel-selecting filters. It aims to first show theoretically that with appropriate scaling capacitive-gap transducers are strong enough to meet the needed coupling requirements; and second, to fully detail an architecture and design procedure needed to realize said filters. Finally, this dissertation provides an actual experimentally demonstrated RF channel-select filter designed using the developed procedures and confirming theoretical predictions. Specifically, this dissertation introduces four methods that make possible the design and fabrication of RF channel-select filters. The first of these introduces a small-signal equivalent circuit for parallel-plate capacitive-gap transduced micromechanical resonators that employs negative capacitance to model the dependence of resonance frequency on electrical stiffness in a way that facilitates the analysis of micromechanical circuits loaded with arbitrary electrical impedances. The new circuit model not only correctly predicts the dependence of electrical stiffness on the impedances loading the input and output electrodes of parallel-plate capacitive-gap transduced micromechanical device, but does so in a visually intuitive way that identifies current drive as most appropriate for

  8. A Newton–Krylov method with an approximate analytical Jacobian for implicit solution of Navier–Stokes equations on staggered overset-curvilinear grids with immersed boundaries

    Science.gov (United States)

    Asgharzadeh, Hafez; Borazjani, Iman

    2016-01-01

    The explicit and semi-implicit schemes in flow simulations involving complex geometries and moving boundaries suffer from time-step size restriction and low convergence rates. Implicit schemes can be used to overcome these restrictions, but implementing them to solve the Navier-Stokes equations is not straightforward due to their non-linearity. Among the implicit schemes for nonlinear equations, Newton-based techniques are preferred over fixed-point techniques because of their high convergence rate but each Newton iteration is more expensive than a fixed-point iteration. Krylov subspace methods are one of the most advanced iterative methods that can be combined with Newton methods, i.e., Newton-Krylov Methods (NKMs) to solve non-linear systems of equations. The success of NKMs vastly depends on the scheme for forming the Jacobian, e.g., automatic differentiation is very expensive, and matrix-free methods without a preconditioner slow down as the mesh is refined. A novel, computationally inexpensive analytical Jacobian for NKM is developed to solve unsteady incompressible Navier-Stokes momentum equations on staggered overset-curvilinear grids with immersed boundaries. Moreover, the analytical Jacobian is used to form preconditioner for matrix-free method in order to improve its performance. The NKM with the analytical Jacobian was validated and verified against Taylor-Green vortex, inline oscillations of a cylinder in a fluid initially at rest, and pulsatile flow in a 90 degree bend. The capability of the method in handling complex geometries with multiple overset grids and immersed boundaries is shown by simulating an intracranial aneurysm. It was shown that the NKM with an analytical Jacobian is 1.17 to 14.77 times faster than the fixed-point Runge-Kutta method, and 1.74 to 152.3 times (excluding an intensively stretched grid) faster than automatic differentiation depending on the grid (size) and the flow problem. In addition, it was shown that using only the

  9. A Newton-Krylov method with an approximate analytical Jacobian for implicit solution of Navier-Stokes equations on staggered overset-curvilinear grids with immersed boundaries.

    Science.gov (United States)

    Asgharzadeh, Hafez; Borazjani, Iman

    2017-02-15

    The explicit and semi-implicit schemes in flow simulations involving complex geometries and moving boundaries suffer from time-step size restriction and low convergence rates. Implicit schemes can be used to overcome these restrictions, but implementing them to solve the Navier-Stokes equations is not straightforward due to their non-linearity. Among the implicit schemes for nonlinear equations, Newton-based techniques are preferred over fixed-point techniques because of their high convergence rate but each Newton iteration is more expensive than a fixed-point iteration. Krylov subspace methods are one of the most advanced iterative methods that can be combined with Newton methods, i.e., Newton-Krylov Methods (NKMs) to solve non-linear systems of equations. The success of NKMs vastly depends on the scheme for forming the Jacobian, e.g., automatic differentiation is very expensive, and matrix-free methods without a preconditioner slow down as the mesh is refined. A novel, computationally inexpensive analytical Jacobian for NKM is developed to solve unsteady incompressible Navier-Stokes momentum equations on staggered overset-curvilinear grids with immersed boundaries. Moreover, the analytical Jacobian is used to form preconditioner for matrix-free method in order to improve its performance. The NKM with the analytical Jacobian was validated and verified against Taylor-Green vortex, inline oscillations of a cylinder in a fluid initially at rest, and pulsatile flow in a 90 degree bend. The capability of the method in handling complex geometries with multiple overset grids and immersed boundaries is shown by simulating an intracranial aneurysm. It was shown that the NKM with an analytical Jacobian is 1.17 to 14.77 times faster than the fixed-point Runge-Kutta method, and 1.74 to 152.3 times (excluding an intensively stretched grid) faster than automatic differentiation depending on the grid (size) and the flow problem. In addition, it was shown that using only the

  10. The Channel Tunnel

    Science.gov (United States)

    2006-01-01

    The Channel Tunnel is a 50.5 km-long rail tunnel beneath the English Channel at the Straits of Dover. It connects Dover, Kent in England with Calais, northern France. The undersea section of the tunnel is unsurpassed in length in the world. A proposal for a Channel tunnel was first put forward by a French engineer in 1802. In 1881, a first attempt was made at boring a tunnel from the English side; the work was halted after 800 m. Again in 1922, English workers started boring a tunnel, and advanced 120 m before it too was halted for political reasons. The most recent attempt was begun in 1987, and the tunnel was officially opened in 1994. At completion it was estimated that the project cost around $18 billion. It has been operating at a significant loss since its opening, despite trips by over 7 million passengers per year on the Eurostar train, and over 3 million vehicles per year. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance. The

  11. UPSO three channel fast photometer

    Science.gov (United States)

    Gupta, S. K.; Sagar, R.; Joshi, S.; Ashoka, B. N.; Babu, V. C.; Seetha, S.; Girish, V.

    2001-09-01

    The design and performance of a modular portable three channel fast photometer is described. It can be disassembled as single individual channels such that the system can also be used as a single channel photometer. The instrument is put into operation since November 1999 on the 1-m UPSO telescope at Nainital. Since then, it is used extensively for the survey of roAp stars in the northern sky at UPSO. The discoveries made using this new photometer are also mentioned.

  12. Upgrading a marketing channels role

    Directory of Open Access Journals (Sweden)

    Tišma-Borota Ankica

    2002-01-01

    Full Text Available As one of the marketing mix instruments, marketing channels were usually behind other instruments (product, price and promotion. Many companies regarded marketing channels as something that was 'left' after more important strategies of price, product and promotion were created. In recent past, things have changed and marketing channels became more interesting for research. This change came as a result of change in global market functioning especially in competitive advantage, distributors' strength and increasing technology.

  13. Pull Promotions and Channel Coordination

    OpenAIRE

    Eitan Gerstner; James D. Hess

    1995-01-01

    This paper recommends that manufacturers consider a pull price promotion as a coordination device in an independent channel of distribution. Uncoordinated decisions of both manufacturer and retailer to charge high prices can break down the effort to expand the market, resulting in losses to the channel as a whole. We show that manufacturers can enhance channel price coordination by designing pull price discounts that target price-conscious consumers. The increased price coordination improves ...

  14. Single-channel kinetics of BK (Slo1 channels

    Directory of Open Access Journals (Sweden)

    Yanyan eGeng

    2015-01-01

    Full Text Available Single-channel kinetics has proven a powerful tool to reveal information about the gating mechanisms that control the opening and closing of ion channels. This introductory review focuses on the gating of large conductance Ca2+- and voltage-activated K+ (BK or Slo1 channels at the single-channel level. It starts with single-channel current records and progresses to presentation and analysis of single-channel data and the development of gating mechanisms in terms of discrete state Markov (DSM models. The DSM models are formulated in terms of the tetrameric modular structure of BK channels, consisting of a central transmembrane pore-gate domain (PGD attached to four surrounding transmembrane voltage sensing domains (VSD and a large intracellular cytosolic domain (CTD, also referred to as the gating ring. The modular structure and data analysis shows that the Ca2+ and voltage dependent gating considered separately can each be approximated by 10-state two-tiered models with 5 closed states on the upper tier and 5 open states on the lower tier. The modular structure and joint Ca2+ and voltage dependent gating are consistent with a 50 state two-tiered model with 25 closed states on the upper tier and 25 open states on the lower tier. Adding an additional tier of brief closed (flicker states to the 10-state or 50-state models improved the description of the gating. For fixed experimental conditions a channel would gate in only a subset of the potential number of states. The detected number of states and the correlations between adjacent interval durations are consistent with the tiered models. The examined models can account for the single-channel kinetics and the bursting behavior of gating. Ca2+ and voltage activate BK channels by predominantly increasing the effective opening rate of the channel with a smaller decrease in the effective closing rate. Ca2+ and depolarization thus activate by mainly destabilizing the closed states.

  15. UMTS Common Channel Sensitivity Analysis

    DEFF Research Database (Denmark)

    Pratas, Nuno; Rodrigues, António; Santos, Frederico

    2006-01-01

    and as such it is necessary that both channels be available across the cell radius. This requirement makes the choice of the transmission parameters a fundamental one. This paper presents a sensitivity analysis regarding the transmission parameters of two UMTS common channels: RACH and FACH. Optimization of these channels...... is performed and values for the key transmission parameters in both common channels are obtained. On RACH these parameters are the message to preamble offset, the initial SIR target and the preamble power step while on FACH it is the transmission power offset....

  16. Development of small-volume, microfluidic chaotic mixers for future application in two-dimensional liquid chromatography

    NARCIS (Netherlands)

    Ianovska, Margaryta A.; Mulder, Patty P. M. F. A.; Verpoorte, Elisabeth

    2017-01-01

    We report a microfluidic chaotic micromixer with staggered herringbone grooves having a geometry optimized for fast mobile-phase modification at the interface of a two-dimensional liquid chromatography system. The volume of the 300 mm mixers is 1.6 microliters and they provide mixing within 26 s at

  17. Negative particle planar and axial channeling and channeling collimation

    Energy Technology Data Exchange (ETDEWEB)

    Carrigan, Richard A., Jr.; /Fermilab

    2009-12-01

    While information exists on high energy negative particle channeling there has been little study of the challenges of negative particle bending and channeling collimation. Partly this is because negative dechanneling lengths are relatively much shorter. Electrons are not particularly useful for investigating negative particle channeling effects because their material interactions are dominated by channeling radiation. Another important factor is that the current central challenge in channeling collimation is the proton-proton Large Hadron Collider (LHC) where both beams are positive. On the other hand in the future the collimation question might reemerge for electon-positron or muon colliders. Dechanneling lengths increase at higher energies so that part of the negative particle experimental challenge diminishes. In the article different approaches to determining negative dechanneling lengths are reviewed. The more complicated case for axial channeling is also discussed. Muon channeling as a tool to investigate dechanneling is also discussed. While it is now possible to study muon channeling it will probably not illuminate the study of negative dechanneling.

  18. ZnO-channel thin-film transistors: Channel mobility

    International Nuclear Information System (INIS)

    Hoffman, R.L.

    2004-01-01

    ZnO-channel thin-film transistor (TFT) test structures are fabricated using a bottom-gate structure on thermally oxidized Si; ZnO is deposited via RF sputtering from an oxide target, with an unheated substrate. Electrical characteristics are evaluated, with particular attention given to the extraction and interpretation of transistor channel mobility. ZnO-channel TFT mobility exhibits severe deviation from that assumed by ideal TFT models; mobility extraction methodology must accordingly be recast so as to provide useful insight into device operation. Two mobility metrics, μ avg and μ inc , are developed and proposed as relevant tools in the characterization of nonideal TFTs. These mobility metrics are employed to characterize the ZnO-channel TFTs reported herein; values for μ inc as high as 25 cm2/V s are measured, comprising a substantial increase in ZnO-channel TFT mobility as compared to previously reported performance for such devices

  19. One-sided asymptotically mean stationary channels

    OpenAIRE

    Simon, Francois

    2014-01-01

    This paper proposes an analysis of asymptotically mean stationary (AMS) communication channels. A hierarchy based on stability properties (stationarity, quasi-stationarity, recurrence and asymptotically mean stationarity) of channels is identified. Stationary channels are a subclass of quasi-stationary channels which are a subclass of recurrent AMS channels which are a subclass of AMS channels. These classes are proved to be stable under Markovian composition of channels (e.g., the cascade of...

  20. An improved channel assessment scheme

    KAUST Repository

    Bader, Ahmed

    2014-05-01

    A source node in a multihop network determines whether to transmit in a channel based on whether the channel is occupied by a packet transmission with a large number of relays; whether the source node is in the data tones back-off zone; and the source node is in the busy tone back-off zone.

  1. Perceived quality of channel zapping

    NARCIS (Netherlands)

    Kooij, R.E.; Ahmed, K.; Brunnström, K.

    2006-01-01

    The end user experience of service quality is critical to the success of a service provider's IPTV deployment program. A key element involved in validating IPTV quality of experience (QoE) is how quickly and reliably users can change TV channels, often referred to as channel zapping. Currently there

  2. Channel Communication and Reconfigurable Hardware

    NARCIS (Netherlands)

    Bos, M.; Havinga, Paul J.M.; Smit, Gerardus Johannes Maria; Karelse, F.

    2000-01-01

    Many applications can be structured as a set of processes or threads that communicate via channels. These threads can be executed on various platforms (e.g. general purpose CPU, DSP, FPGA, etc). In our research we apply channels as a basic communication mechanism between threads in a reconfigurable

  3. Hydraulic jumps in a channel

    DEFF Research Database (Denmark)

    Bonn, D.; Andersen, Anders Peter; Bohr, Tomas

    2009-01-01

    We present a study of hydraulic jumps with flow predominantly in one direction, created either by confining the flow to a narrow channel with parallel walls or by providing an inflow in the form of a narrow sheet. In the channel flow, we find a linear height profile upstream of the jump as expected...

  4. Defect Distributions in Channeling Experiments

    DEFF Research Database (Denmark)

    Andersen, Hans Henrik; Sigmund, P.

    1965-01-01

    A simple collision model allows to calculate energy losses of perfectly channeled particles. The maximum energy loss is related in a simple way to the displacement energy of lattice atoms perpendicular to the channel. From that, one obtains rather definite predictions on the possibility...

  5. Theoretical investigations on two-phase flow instability in parallel channels under axial non-uniform heating

    International Nuclear Information System (INIS)

    Lu, Xiaodong; Wu, Yingwei; Zhou, Linglan; Tian, Wenxi; Su, Guanghui; Qiu, Suizheng; Zhang, Hong

    2014-01-01

    Highlights: • We developed a model based on homogeneous flow model to analyze two-phase flow instability in parallel channels. • The influence of axial non-uniform heating on the system stability has been investigated. • Influences of various factors on system instability under cosine heat flux have been studied. • The system under top-peaked heat flux is the most stable system. - Abstract: Two-phase flow instability in parallel channels heated by axial non-uniform heat flux has been theoretically studied in this paper. The system control equations of parallel channels were established based on the homogeneous flow model in two-phase region. Semi-implicit finite-difference scheme and staggered mesh method were used to discretize the equations, and the difference equations were solved by chasing method. Cosine, bottom-peaked and top-peaked heat fluxes were used to study the influence of non-uniform heating on two-phase flow instability of the parallel channels system. The marginal stability boundaries (MSB) of parallel channels and three-dimensional instability spaces (or instability reefs) under different heat flux conditions have been obtained. Compared with axial uniform heating, axial non-uniform heating will affect the system stability. Cosine and bottom-peaked heat fluxes can destabilize the system stability in high inlet subcooling region, while the opposite effect can be found in low inlet subcooling region. However, top-peaked heat flux can enhance the system stability in the whole region. In addition, for cosine heat flux, increasing the system pressure or inlet resistance coefficient can strengthen the system stability, and increasing the heating power will destabilize the system stability. The influence of inlet subcooling number on the system stability is multi-valued under cosine heat flux

  6. Voltage-gated Proton Channels

    Science.gov (United States)

    DeCoursey, Thomas E.

    2014-01-01

    Voltage-gated proton channels, HV1, have vaulted from the realm of the esoteric into the forefront of a central question facing ion channel biophysicists, namely the mechanism by which voltage-dependent gating occurs. This transformation is the result of several factors. Identification of the gene in 2006 revealed that proton channels are homologues of the voltage-sensing domain of most other voltage-gated ion channels. Unique, or at least eccentric, properties of proton channels include dimeric architecture with dual conduction pathways, perfect proton selectivity, a single-channel conductance ~103 smaller than most ion channels, voltage-dependent gating that is strongly modulated by the pH gradient, ΔpH, and potent inhibition by Zn2+ (in many species) but an absence of other potent inhibitors. The recent identification of HV1 in three unicellular marine plankton species has dramatically expanded the phylogenetic family tree. Interest in proton channels in their own right has increased as important physiological roles have been identified in many cells. Proton channels trigger the bioluminescent flash of dinoflagellates, facilitate calcification by coccolithophores, regulate pH-dependent processes in eggs and sperm during fertilization, secrete acid to control the pH of airway fluids, facilitate histamine secretion by basophils, and play a signaling role in facilitating B-cell receptor mediated responses in B lymphocytes. The most elaborate and best-established functions occur in phagocytes, where proton channels optimize the activity of NADPH oxidase, an important producer of reactive oxygen species. Proton efflux mediated by HV1 balances the charge translocated across the membrane by electrons through NADPH oxidase, minimizes changes in cytoplasmic and phagosomal pH, limits osmotic swelling of the phagosome, and provides substrate H+ for the production of H2O2 and HOCl, reactive oxygen species crucial to killing pathogens. PMID:23798303

  7. Amazon floodplain channels regulate channel-floodplain water exchange

    Science.gov (United States)

    Bates, P. D.; Baugh, C.; Trigg, M.

    2017-12-01

    We examine the role of floodplain channels in regulating the exchange of water between the Amazon main stem and its extensive floodplains using a combination of field survey, remote sensing and numerical modelling for a 30,000 km2 area around the confluence of the Solimões and Purus rivers. From Landsat imagery we identified 1762 individual floodplain channel reaches with total length of nearly 9300 line km that range in width from 900m to 20m. Using a boat survey we measured width and depth along 509 line km of floodplain channels in 45 separate reaches and used these data to develop geomorphic relationships between width and depth. This enabled reconstruction of the depth of all other channels in the Landsat survey to an RMSE of 2.5m. We then constructed a 2D hydraulic model of this site which included all 9300km of floodplain channels as sub-grid scale features using a recently developed version of the LISFLOOD-FP code. The DEM for the model was derived from a version of the SRTM Digital Elevation Model that was processed to remove vegetation artefacts. The model was run at 270m resolution over the entire 30,000 km2 domain for the period from 2002-2009. Simulations were run with and without floodplain channels to examine the impact of these features on floodplain flow dynamics and storage. Simulated floodplain channel hydraulics were validated against a combination of in-situ and remotely sensed data. Our results show that approximately 100 km3 of water is exchanged between the channel and the floodplain during a typical annual cycle, and 8.5±2.1% of mainstem flows is routed through the floodplain. The overall effect of floodplains channels was to increase the duration of connections between the Amazon River and the floodplain. Inclusion of floodplain channels in the model increased inundation volume by 7.3% - 11.3% at high water, and decreased it at low water by 4.0% - 16.6%, with the range in these estimates due to potential errors in floodplain channel

  8. NALCN ion channels have alternative selectivity filters resembling calcium channels or sodium channels

    NARCIS (Netherlands)

    Senatore, A.; Monteil, A.; van Minnen, J.; Smit, A.B.; Spafford, J.D.

    2013-01-01

    NALCN is a member of the family of ion channels with four homologous, repeat domains that include voltage-gated calcium and sodium channels. NALCN is a highly conserved gene from simple, extant multicellular organisms without nervous systems such as sponges and placozoans and mostly remains a single

  9. Substrate channeling in proline metabolism

    Science.gov (United States)

    Arentson, Benjamin W.; Sanyal, Nikhilesh; Becker, Donald F.

    2012-01-01

    Proline metabolism is an important pathway that has relevance in several cellular functions such as redox balance, apoptosis, and cell survival. Results from different groups have indicated that substrate channeling of proline metabolic intermediates may be a critical mechanism. One intermediate is pyrroline-5-carboxylate (P5C), which upon hydrolysis opens to glutamic semialdehyde (GSA). Recent structural and kinetic evidence indicate substrate channeling of P5C/GSA occurs in the proline catabolic pathway between the proline dehydrogenase and P5C dehydrogenase active sites of bifunctional proline utilization A (PutA). Substrate channeling in PutA is proposed to facilitate the hydrolysis of P5C to GSA which is unfavorable at physiological pH. The second intermediate, gamma-glutamyl phosphate, is part of the proline biosynthetic pathway and is extremely labile. Substrate channeling of gamma-glutamyl phosphate is thought to be necessary to protect it from bulk solvent. Because of the unfavorable equilibrium of P5C/GSA and the reactivity of gamma-glutamyl phosphate, substrate channeling likely improves the efficiency of proline metabolism. Here, we outline general strategies for testing substrate channeling and review the evidence for channeling in proline metabolism. PMID:22201749

  10. Melt Channel Formation in Paraffin With Applications to Lava Channels

    Science.gov (United States)

    Whitehead, J. A.; Mills, C. J.

    2005-12-01

    We present the results from laboratory experiments designed to explore channel formation caused by instabilities in fluid flow, and to provide a simple experimental basis to facilitate the extension of lava channel theory. Kelemen et. al. [1995] reported on a series of experiments that explored channel formation resulting from fluid instabilities caused by the ``reactive infiltration instability'' (RII). However, the material used in portions of their experiments was undesirable because of a poorly suited rheology. Therefore, our experiments were initiated as an extension of those earlier experiments, using instead a material with more robust rheological properties. The material chosen for this series of experiments is a paraffin with a freezing temperature of 4°C, which is transparent when liquid and opaque-white when frozen. The paraffin is pumped at a constant and controlled rate into a narrow gap between two circular plates, both with a diameter of ~51cm. The gap is open along the circumference of the plates, allowing the paraffin to flow out of the gap once it reaches the edge of the plate. The upper plate is constructed of Plexiglas to allow observation of the wax below, and it has a hole in the center through which the paraffin is pumped. The lower plate is constructed of aluminum, painted black, and kept at -5°C by circulating coolant through a reservoir below the it. As the paraffin, which is kept at 20°C before being pumped into the gap, flows over the cold lower plate, it begins to freeze and eventually fills up the gap between the plates. A single channel then forms, surrounded by solid paraffin, and the liquid being pumped in is transported via this channel to the edge of the plate. This is a stable state for all but the lowest flow rates attempted and verifies the results from the earlier work exploring the RII. We conducted experiments at different flows rates from 270mL/min to <30mL/min, and recorded the dimensions of the steady state channel

  11. ACE Strategy with Virtual Channels

    Directory of Open Access Journals (Sweden)

    T. Tichy

    2008-12-01

    Full Text Available Cochlear implant is an electronic device, which can mediate hearing sensations to profoundly deaf people. Contemporary cochlear implants are sophisticated electronic devices; however, their performance could still be improved. This paper describes an experiment we made in that direction: additional 21 virtual channels were implemented by sequential stimulation of adjacent intracochlear electrodes, and the ACE strategy with virtual channels (ACEv, Advanced Combination Encoder strategy with virtual channels for the Nucleus® 24 Cochlear Implant System was created and verified in a clinical test with four patients.

  12. Sodium channels in planar lipid bilayers. Channel gating kinetics of purified sodium channels modified by batrachotoxin

    Science.gov (United States)

    1986-01-01

    Single channel currents of sodium channels purified from rat brain and reconstituted into planar lipid bilayers were recorded. The kinetics of channel gating were investigated in the presence of batrachotoxin to eliminate inactivation and an analysis was conducted on membranes with a single active channel at any given time. Channel opening is favored by depolarization and is strongly voltage dependent. Probability density analysis of dwell times in the closed and open states of the channel indicates the occurrence of one open state and several distinct closed states in the voltage (V) range-120 mV less than or equal to V less than or equal to +120 mV. For V less than or equal to 0, the transition rates between stages are exponentially dependent on the applied voltage, as described in mouse neuroblastoma cells (Huang, L. M., N. Moran, and G. Ehrenstein. 1984. Biophysical Journal. 45:313- 322). In contrast, for V greater than or equal to 0, the transition rates are virtually voltage independent. Autocorrelation analysis (Labarca, P., J. Rice, D. Fredkin, and M. Montal. 1985. Biophysical Journal. 47:469-478) shows that there is no correlation in the durations of successive open or closing events. Several kinetic schemes that are consistent with the experimental data are considered. This approach may provide information about the mechanism underlying the voltage dependence of channel activation. PMID:2426388

  13. Multi-channel Kondo necklace

    International Nuclear Information System (INIS)

    Fazekas, P.; Kee Haeyoung.

    1993-06-01

    A multi-channel generalization of Doniach's Kondo necklace model is formulated, and its phase diagram studied in the mean-field approximation. Our intention is to introduce the possible simplest model which displays some of the features expected from the overscreened Kondo lattice. The N conduction electron channels are represented by N sets of pseudospins τ J , j = 1 1,..., N which are all antiferromagnetically coupled to a periodic array of modul S = 1/2 spins. Exploiting permutation symmetry in the channel index j allows us to write down the self-consistency equation for general N. For N > 2, we find that the critical temperature is rising with increasing Kondo interaction; we interpret this effect by pointing out that the Kondo coupling creates the composite pseudospin objects which undergo an ordering transition. The relevance of our findings to the underlying fermionic multi-channel problem is discussed. (author). 33 refs, 1 fig

  14. FMCG companies specific distribution channels

    Directory of Open Access Journals (Sweden)

    Ioana Barin

    2009-12-01

    Full Text Available Distribution includes all activities undertaken by the producer, alone or in cooperation, since the end of the final finished products or services until they are in possession of consumers. The distribution consists of the following major components: distribution channels or marketing channels, which together form a distribution network; logistics o rphysical distribution. In order to effective achieve, distribution of goods requires an amount of activities and operational processes related to transit of goods from producer to consumer, the best conditions, using existing distribution channels and logistics system. One of the essential functions of a distribution is performing acts of sale, through which, with the actual movement of goods, their change of ownership takes place, that the successive transfer of ownership from producer to consumer. This is an itinerary in the economic cycle of goods, called the distribution channel.

  15. Potassium Channels in Neurofbromatosis-1

    National Research Council Canada - National Science Library

    Chen, Mingkui

    2006-01-01

    .... We were the first to investigate potential mechanisms of cognitive impairment in NF-1 at the molecular level involving potassium channels, and demonstrated a possible mechanism for the learning deficits seen in NF1...

  16. Marketing channel behaviour and performance

    OpenAIRE

    Duarte, Margarida

    2000-01-01

    Thesis submitted to University of Manchester for the degree of Doctor of Philosophy in the Faculty of Business Administration. A major aim of this study is to offer a relatively comprehensive picture of marketing channel behaviour and performance. Given the statistical difficulties in testing a very large, comprehensive model to achieve this aim, two separate but overlapping models are proposed. One model specifically addresses behaviour in marketing channels, while the other integrates k...

  17. Learning the MMSE Channel Estimator

    OpenAIRE

    Neumann, David; Wiese, Thomas; Utschick, Wolfgang

    2017-01-01

    We present a method for estimating conditionally Gaussian random vectors with random covariance matrices, which uses techniques from the field of machine learning. Such models are typical in communication systems, where the covariance matrix of the channel vector depends on random parameters, e.g., angles of propagation paths. If the covariance matrices exhibit certain Toeplitz and shift-invariance structures, the complexity of the MMSE channel estimator can be reduced to O(M log M) floating ...

  18. Eight channel telephone telemetry system

    Science.gov (United States)

    Smith, R. E.

    1973-01-01

    A portable, indirectly coupled telephone system is reported which transmits/to a central receiving site eight channels of EEG data of sufficient fidelity for screening and/or limited diagnostic use. The system requires no electrical connection to the telephone at the transmitter or at the receiver and is compatible with common EEG recording practice for real-time recording. It accepts 8 input channels simultaneously with one telephone transmitter and one telephone receiver operates from standard power sources.

  19. Electrophysiological characterisation of KCNQ channel modulators

    DEFF Research Database (Denmark)

    Schrøder, R.L

    Potassium (K+) ion channels are ubiquitously expressed in mammalian cells, and each channel serves a precise physiological role due to its specific biophysical characteristics and expression pattern. A few K+ channels are targets for certain drugs, and in this thesis it is suggested that the KCNQ K......+ channels may be targets for neuroprotective, anti-epileptic and anti-nociceptive compounds. The importance of these channels is underscored by the fact that four out of five KCNQ channel subtypes are involved in severe human diseases. However, the pharmacology of the KCNQ channels is yet poorly understood...... as these channels were identified only recently. Therefore, there is a need for understanding the biophysical behavior and pharmacology of these ion channels. KCNQ channels belong to the group of voltage-activated K+ channels. The subfamily consists of KCNQ1-5, which is primarily expressed in the CNS, heart, ear...

  20. NALCN ion channels have alternative selectivity filters resembling calcium channels or sodium channels.

    Directory of Open Access Journals (Sweden)

    Adriano Senatore

    Full Text Available NALCN is a member of the family of ion channels with four homologous, repeat domains that include voltage-gated calcium and sodium channels. NALCN is a highly conserved gene from simple, extant multicellular organisms without nervous systems such as sponges and placozoans and mostly remains a single gene compared to the calcium and sodium channels which diversified into twenty genes in humans. The single NALCN gene has alternatively-spliced exons at exons 15 or exon 31 that splices in novel selectivity filter residues that resemble calcium channels (EEEE or sodium channels (EKEE or EEKE. NALCN channels with alternative calcium, (EEEE and sodium, (EKEE or EEKE -selective pores are conserved in simple bilaterally symmetrical animals like flatworms to non-chordate deuterostomes. The single NALCN gene is limited as a sodium channel with a lysine (K-containing pore in vertebrates, but originally NALCN was a calcium-like channel, and evolved to operate as both a calcium channel and sodium channel for different roles in many invertebrates. Expression patterns of NALCN-EKEE in pond snail, Lymnaea stagnalis suggest roles for NALCN in secretion, with an abundant expression in brain, and an up-regulation in secretory organs of sexually-mature adults such as albumen gland and prostate. NALCN-EEEE is equally abundant as NALCN-EKEE in snails, but is greater expressed in heart and other muscle tissue, and 50% less expressed in the brain than NALCN-EKEE. Transfected snail NALCN-EEEE and NALCN-EKEE channel isoforms express in HEK-293T cells. We were not able to distinguish potential NALCN currents from background, non-selective leak conductances in HEK293T cells. Native leak currents without expressing NALCN genes in HEK-293T cells are NMDG(+ impermeant and blockable with 10 µM Gd(3+ ions and are indistinguishable from the hallmark currents ascribed to mammalian NALCN currents expressed in vitro by Lu et al. in Cell. 2007 Apr 20;129(2:371-83.

  1. Planar channeling in superlattices: Theory

    International Nuclear Information System (INIS)

    Ellison, J.A.; Picraux, S.T.; Allen, W.R.; Chu, W.K.

    1988-01-01

    The well-known continuum model theory for planar channeled energetic particles in perfect crystals is extended to layered crystalline structures and applied to superlattices. In a strained-layer structure, the planar channels with normals which are not perpendicular to the growth direction change their direction at each interface, and this dramatically influences the channeling behavior. The governing equation of motion for a planar channeled ion in a strained-layer superlattice with equal layer thicknesses is a one degree of freedom nonlinear oscillator which is periodically forced with a sequence of δ functions. These δ functions, which are of equal spacing and amplitude with alternating sign, represent the tilts at each of the interfaces. Thus upon matching an effective channeled particle wavelength, corresponding to a natural period of the nonlinear oscillator, to the period of the strained-layer superlattice, corresponding to the periodic forcing, strong resonance effects are expected. The condition of one effective wavelength per period corresponds to a rapid dechanneling at a well-defined depth (catastrophic dechanneling), whereas two wavelengths per period corresponds to no enhanced dechanneling after the first one or two layers (resonance channeling). A phase plane analysis is used to characterize the channeled particle motion. Detailed calculations using the Moliere continuum potential are compared with our previously described modified harmonic model, and new results are presented for the phase plane evolution, as well as the dechanneling as a function of depth, incident angle, energy, and layer thickness. General scaling laws are developed and nearly universal curves are obtained for the dechanneling versus depth under catastrophic dechanneling

  2. Volume of the space of qubit-qubit channels and state transformations under random quantum channels

    OpenAIRE

    Lovas, Attila; Andai, Attila

    2017-01-01

    The simplest building blocks for quantum computations are the qubit-qubit quantum channels. In this paper, we analyze the structure of these channels via their Choi representation. The restriction of a quantum channel to the space of classical states (i.e. probability distributions) is called the underlying classical channel. The structure of quantum channels over a fixed classical channel is studied, the volume of general and unital qubit channels with respect to the Lebesgue measure is comp...

  3. 47 CFR 76.57 - Channel positioning.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Channel positioning. 76.57 Section 76.57... CABLE TELEVISION SERVICE Carriage of Television Broadcast Signals § 76.57 Channel positioning. (a) At... choice of channel position when it requests carriage. Channel positioning requests from local commercial...

  4. Lithofacies characterization and channel development in the ...

    African Journals Online (AJOL)

    ... and multistory channel complex. The different stages of channel development can be considered in terms of low efficiency and high efficiency flows, which are related to slope equilibrium. Keywords: Outcrop, slope, channel development, channel architecture, process model, lowstand. Journal of Mining and Geology Vol.

  5. Information transfer through quantum channels

    International Nuclear Information System (INIS)

    Kretschmann, D.

    2007-01-01

    This PhD thesis represents work done between Aug. 2003 and Dec. 2006 in Reinhard F. Werner's quantum information theory group at Technische Universitaet Braunschweig, and Artur Ekert's Centre for Quantum Computation at the University of Cambridge. My thesis falls into the field of abstract quantum information theory. This work investigates both fundamental properties of quantum channels and their asymptotic capacities for classical as well as quantum information transfer. Stinespring's theorem is the basic structure theorem for quantum channels. It implies that every quantum channel can be represented as a unitary evolution on an enlarged system. In Ch. 3 we present a continuity theorem for Stinespring's representation: two quantum channels are similar if and only if it is possible to find unitary implementations that are likewise similar, with dimension-independent norm bounds. The continuity theorem allows to derive a formulation of the information-disturbance tradeoff in terms of quantum channels, and a continuity estimate for the no-broadcasting principle. In Ch. 4 we then apply the continuity theorem to give a strengthened no-go proof for quantum bit commitment, an important cryptographic primitive. This result also provides a natural characterization of those protocols that fall outside the standard setting of unconditional security, and thus may allow secure bit commitment. We present a new such protocol whose security relies on decoherence in the receiver's lab. Ch. 5 reviews the capacities of quantum channels for the transfer of both classical and quantum information, and investigates several variations in the notion of channel capacity. Memory effects are then investigated in detail in Ch. 6. We advertise a model which is sufficiently general to encompass all causal automata: every quantum process in which the outputs up to any given time t do not depend on the inputs at times t'>t can be represented as a concatenated memory channel. We then explain how

  6. Information transfer through quantum channels

    Energy Technology Data Exchange (ETDEWEB)

    Kretschmann, D.

    2007-03-12

    This PhD thesis represents work done between Aug. 2003 and Dec. 2006 in Reinhard F. Werner's quantum information theory group at Technische Universitaet Braunschweig, and Artur Ekert's Centre for Quantum Computation at the University of Cambridge. My thesis falls into the field of abstract quantum information theory. This work investigates both fundamental properties of quantum channels and their asymptotic capacities for classical as well as quantum information transfer. Stinespring's theorem is the basic structure theorem for quantum channels. It implies that every quantum channel can be represented as a unitary evolution on an enlarged system. In Ch. 3 we present a continuity theorem for Stinespring's representation: two quantum channels are similar if and only if it is possible to find unitary implementations that are likewise similar, with dimension-independent norm bounds. The continuity theorem allows to derive a formulation of the information-disturbance tradeoff in terms of quantum channels, and a continuity estimate for the no-broadcasting principle. In Ch. 4 we then apply the continuity theorem to give a strengthened no-go proof for quantum bit commitment, an important cryptographic primitive. This result also provides a natural characterization of those protocols that fall outside the standard setting of unconditional security, and thus may allow secure bit commitment. We present a new such protocol whose security relies on decoherence in the receiver's lab. Ch. 5 reviews the capacities of quantum channels for the transfer of both classical and quantum information, and investigates several variations in the notion of channel capacity. Memory effects are then investigated in detail in Ch. 6. We advertise a model which is sufficiently general to encompass all causal automata: every quantum process in which the outputs up to any given time t do not depend on the inputs at times t'>t can be represented as a concatenated memory

  7. Optimality of private quantum channels

    International Nuclear Information System (INIS)

    Bouda, Jan; Ziman, Mario

    2007-01-01

    We addressed the question of optimality of private quantum channels. We have shown that the Shannon entropy of the classical key necessary to securely transfer the quantum information is lower bounded by the entropy exchange of the private quantum channel E and the von Neumann entropy of the ciphertext state ρ (0) . Based on these bounds we have shown that decomposition of private quantum channels into orthogonal unitaries (if they exist) optimizes the entropy. For non-ancillary single-qubit PQC we have derived the optimal entropy for the arbitrary set of plaintexts. In particular, we have shown that except when the (closure of the) set of plaintexts contains all states, one bit key is sufficient. We characterized and analysed all the possible single-qubit private quantum channels for an arbitrary set of plaintexts. For the set of plaintexts consisting of all qubit states we have characterized all possible approximate private quantum channels and we have derived the relation between the security parameter and the corresponding minimal entropy

  8. The minimum yield in channeling

    International Nuclear Information System (INIS)

    Uguzzoni, A.; Gaertner, K.; Lulli, G.; Andersen, J.U.

    2000-01-01

    A first estimate of the minimum yield was obtained from Lindhard's theory, with the assumption of a statistical equilibrium in the transverse phase-space of channeled particles guided by a continuum axial potential. However, computer simulations have shown that this estimate should be corrected by a fairly large factor, C (approximately equal to 2.5), called the Barrett factor. We have shown earlier that the concept of a statistical equilibrium can be applied to understand this result, with the introduction of a constraint in phase-space due to planar channeling of axially channeled particles. Here we present an extended test of these ideas on the basis of computer simulation of the trajectories of 2 MeV α particles in Si. In particular, the gradual trend towards a full statistical equilibrium is studied. We also discuss the introduction of this modification of standard channeling theory into descriptions of the multiple scattering of channeled particles (dechanneling) by a master equation and show that the calculated minimum yields are in very good agreement with the results of a full computer simulation

  9. Charged and Neutral Particles Channeling Phenomena Channeling 2008

    Science.gov (United States)

    Dabagov, Sultan B.; Palumbo, Luigi

    2010-04-01

    On the discovery of coherent Bremsstrahlung in a single crystal at the Frascati National Laboratories / C. Barbiellini, G. P. Murtas and S. B. Dabagov -- Advances in coherent Bremsstrahlung and LPM-effect studies (to the lOOth anniversary from the birth of L. D. Landau) / N. F. Shul'ga -- Spectra of radiation and created particles at intermediate energy in oriented crystal taking into account energy loss / V. N. Baier and V. M. Katkov -- The coherent Bremsstrahlung beam at MAX-lab facility / K. Fissum ... [et al.] -- Radiation from thin, structured targets (CERN NA63) / A. Dizdar -- Hard incoherent radiation in thick crystals / N. F. Shul'ga, V. V. Syshchenko and A. I. Tarnovsky -- Coherent Bremsstrahlung in periodically deformed crystals with a complex base / A. R. Mkrtchyan, A. A. Saharian and V. V. Parazian -- Induction of coherent x-ray Bremsstrahlung in crystals under the influence of acoustic waves / A. R. Mkrtchyan and V. V. Parazian -- Coherent processes in bent single crystals / V. A. Maisheev -- Experimental and theoretical investigation of complete transfer phenomenon for media with various heat exchange coefficients / A. R. Mkrtchyan, A. E. Movsisyan and V. R. Kocharyan -- Coherent pair production in crystals / A. R. Mkrtchyan, A. A. Saharian and V. V. Parazian -- Negative particle planar and axial channeling and channeling collimation / R. A. Carrigan, Jr. -- CERN crystal-based collimation in modern hadron colliders / W. Scandale -- Studies and application of bent crystals for beam steering at 70 GeV IHEP accelerator / A. G. Afonin ... [et al.] -- Crystal collimation studies at the Tevatron (T-980) / N. V. Mokhov ... [et al.] -- Fabrication of crystals for channeling of particles in accellerators / A. Mazzolari ... [et al.] -- New possibilities to facilitate collimation of both positively and negatively charged particle beams by crystals / V. Guidi, A. Mazzolari and V. V. Tikhomirov -- Increase of probability of particle capture into the channeling

  10. Channels of Monetary Transmission in the CIS

    OpenAIRE

    Jamilov, Rustam

    2012-01-01

    Twenty years have passed since the breakdown of the Soviet Union, and it is time to draw a concluding line for monetary policy efficiency in the Commonwealth of Independent States (CIS). We propose a comprehensive treatment of the subject for nine members of the CIS for the period of 2000-2009. Four transmission channels are investigated: interest rate channel, exchange rate channel, bank lending channel, and monetary channel. First, we design a VAR framework for each CIS member-state and inv...

  11. Modification of single Na+ channels by batrachotoxin.

    OpenAIRE

    Quandt, F N; Narahashi, T

    1982-01-01

    The modifications in the properties of voltage-gated Na+ channels caused by batrachotoxin were studied by using the patch clamp method for measuring single channel currents from excised membranes of N1E-115 neuroblastoma cells. The toxin-modified open state of the Na+ channel has a decreased conductance in comparison to that of normal Na+ channels. The lifetime of the modified open state is drastically prolonged, and channels now continue to open during a maintained depolarization so that the...

  12. Insect sodium channels and insecticide resistance

    OpenAIRE

    Dong, Ke

    2007-01-01

    Voltage-gated sodium channels are essential for the generation and propagation of action potentials (i.e., electrical impulses) in excitable cells. Although most of our knowledge about sodium channels is derived from decades of studies of mammalian isoforms, research on insect sodium channels is revealing both common and unique aspects of sodium channel biology. In particular, our understanding of the molecular dynamics and pharmacology of insect sodium channels has advanced greatly in recent...

  13. Pharmacological modulation of SK3 channels

    DEFF Research Database (Denmark)

    Grunnet, M; Jespersen, Thomas; Angelo, K

    2001-01-01

    Small-conductance, calcium-activated K+ channels (SK channels) are voltage-insensitive channels that have been identified molecularly within the last few years. As SK channels play a fundamental role in most excitable cells and participate in afterhyperpolarization (AHP) and spike-frequency adapt...... at concentrations of 3 microM and above. Amitriptyline, a tricyclic antidepressive widely used clinically, inhibits SK3 channels with an IC50 of 39.1 +/- 10 microM (n=6)....

  14. Axial channeling of uttrarelativistic electrons

    Energy Technology Data Exchange (ETDEWEB)

    Telegin, V.I.; Khokonov, M.Kh. (Moskovskij Gosudarstvennyj Univ. (USSR). Nauchno-Issledovatel' skij Inst. Yadernoj Fiziki)

    1982-07-01

    The dynamics of motion of ultrarelativistic electrons under axial channeling conditions is investigated. The analysis is based on the solution of the kinetic equation obtained recently by Beloshitsky and Kumakhov. The particle dechanneling function is investigated as depending on the type of a crystal, particle energy and angle of entrance into the single crystal. It is found that for most of the beam the major diffusion mechanism is scattering by electrons. It is shown that an optimal depth range exists for which the fraction of channeled particles sharply increases at the expense of the quasi-channeled particles. In a number of cases the dechanneling length for crystals with high atomic numbers may be greater than that of light elements.

  15. Axial channeling of uttrarelativistic electrons

    International Nuclear Information System (INIS)

    Telegin, V.I.; Khokonov, M.Kh.

    1982-01-01

    The dynamics of motion of ultrarelativistic electrons under axial channeling conditions is investigated. The analysis is based on the solution of the kinetic equation obtained recently by Beloshitsky and Kumakhov. The particle dechanneling function is investigated as depending on the type of a crystal, particle energy and angle of entrance into the single crystal. It is found that for most of the beam the major diffusion mechanism is scattering by electrons. It is shown that an optimal depth range exists for which the fraction of channeled particles sharply increases at the expense of the quasi-channeled particles. In a number of cases the dechanneling length for crystals with high atomic numbers may be greater than that of light elements

  16. Evaluate interference in digital channels

    Science.gov (United States)

    Davarian, F.; Sumida, J.

    1985-01-01

    Any future mobile satellite service (MSS) which is to provide simultaneous mobile communications for a large number of users will have to make very efficient use of the spectrum. As the spectrum available for an MSS is limited, the system's channels should be packed as closely together as possible, with minimum-width guard bands. In addition the employment of frequency reuse schemes is an important factor. Difficulties regarding these solutions are related to the introduction of interference in the link. A balance must be achieved between the competing aims of spectrum conservation and low interference. While the interference phenomenon in narrowband FM voice channels is reasonably well understood, very little effort, however, has been devoted to the problem in digital radios. Attention is given to work, which illuminates the effects of cochannel and adjacent channel interference on digital FM (FSK) radios.

  17. Pannexin-1 channels in epilepsy.

    Science.gov (United States)

    Aquilino, Mark S; Whyte-Fagundes, Paige; Zoidl, Georg; Carlen, Peter L

    2017-09-05

    Pannexin-1 (Panx1) expression is raised in several animal seizure models and in resected human epileptic brain tissue, suggesting relevance to epilepsy. Multiple factors that are characteristic of seizures are thought to regulate Panx1 channel opening, including elevated levels of extracellular K + . Panx1, when open, 1) releases ATP, glutamate, and other metabolites into the extracellular medium, and 2) may depolarize the membrane due to a channel reversal potential around 0mV. Resultant ATP release from stimulated Panx1 can activate purinergic receptors, including P2X7 receptors. Glutamate and other signaling molecules released by Panx1 opening may have both excitatory and inhibitory actions on seizure generation. This review examines the critical and complex roles of Panx1 channels in epilepsy, which could provide a basis for future therapeutics. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Antenna for Ultrawideband Channel Sounding

    DEFF Research Database (Denmark)

    Zhekov, Stanislav Stefanov; Tatomirescu, Alexandru; Pedersen, Gert F.

    2016-01-01

    A novel compact antenna for ultrawideband channel sounding is presented. The antenna is composed of a symmetrical biconical antenna modified by adding a cylinder and a ring to each cone. A feeding coaxial cable is employed during the simulations in order to evaluate and reduce its impact on the a......A novel compact antenna for ultrawideband channel sounding is presented. The antenna is composed of a symmetrical biconical antenna modified by adding a cylinder and a ring to each cone. A feeding coaxial cable is employed during the simulations in order to evaluate and reduce its impact...

  19. The Orange Juice Distribution Channels

    African Journals Online (AJOL)

    the agents in the European marketing channels of the FCOJ, focusing on the final juice consumers, retailing, food ... Marketing channels are defined as “a set of interdependent organisations involved in the process of making a .... Mexico - 8.0 8.0 8.3 8.0 8.0 - -. Venezuela - 7.9 8.0 7.5 7.3 7.1 - -. Taiwan - 4.4 4.9 6.2 6.6 7.0 - -.

  20. Visualizing multi-channel networks

    DEFF Research Database (Denmark)

    Antemijczuk, Paweł; Magiera, Marta; Jørgensen, Sune Lehmann

    2014-01-01

    In this paper, we propose a visualization to illustrate social interactions, built from multiple distinct channels of communication. The visualization displays a summary of dense personal information in a compact graphical notation. The starting point is an abstract drawing of a spider’s web. Below...

  1. Sorting out river channel patterns

    NARCIS (Netherlands)

    Kleinhans, M.G.

    2010-01-01

    Rivers self-organize their pattern/planform through feedbacks between bars, channels, floodplain and vegetation, which emerge as a result of the basic spatial sorting process of wash load sediment and bed sediment. The balance between floodplain formation and destruction determines the width and

  2. Sales promotion and channel coordination

    NARCIS (Netherlands)

    Wierenga, B.; Soethoudt, J.M.

    2010-01-01

    Consumer sales promotions are usually the result of the decisions of two marketing channel parties, the manufacturer and the retailer. In making these decisions, each party normally follows its own interest: i.e. maximizes its own profit. Unfortunately, this results in a suboptimal outcome for the

  3. Single top t-channel

    CERN Document Server

    Faltermann, Nils

    2017-01-01

    The production of single top quarks allows to study the interplay of top quark physics and the electroweak sector of the standard model. Deviations from predictions can be a hint for physics beyond the standard model. The t-channel is the dominant production mode for single top quarks at the LHC. This talk presents the latest measurements from the ATLAS and CMS collaborations.

  4. Improved Ion-Channel Biosensors

    Science.gov (United States)

    Nadeau, Jay; White, Victor; Dougherty, Dennis; Maurer, Joshua

    2004-01-01

    An effort is underway to develop improved biosensors of a type based on ion channels in biomimetic membranes. These sensors are microfabricated from silicon and other materials compatible with silicon. As described, these sensors offer a number of advantages over prior sensors of this type.

  5. CONDUCTIVE CHANNEL FOR ENERGY TRANSMISSION

    Directory of Open Access Journals (Sweden)

    V. V. Apollonov

    2014-01-01

    Full Text Available Laser spark obtained by using a conical optics is much more appropriate to form conducting channels in atmosphere. Only two types of lasers are actively considered to be used in forming high-conductivity channels in atmosphere, controlled by laser spark: pulsed sub-microsecond gas and chemical lasers (CO2, DF and short pulse solid-state and UV lasers. Main advantage of short pulse lasers is their ability in forming of super long ionized channels with a characteristic diameter of ~100  µ  in atmosphere along the  beam propagation direction. At estimated electron densities below  10 ⋅ 16 cm–3 in these filaments and laser wavelengths in the range of 0,5–1,0 mm, the plasma barely absorbs laser radiation.  In this case, the length of the track composed of many filaments is determined by the laser intensity and may reach many kilometers at a femtosecond pulse energy of ~100 mJ. However, these lasers could not be used to form high-conductivity long channels in atmosphere. The ohmic resistance of this type a conducting channels turned out to be very high, and the gas in the channels could not be strongly heated (< 1 J. An electric breakdown controlled by radiation of femtosecond solid-state laser was implemented in only at a length of 3 m with a voltage of 2 MV across the discharge gap (670 kV/m.Not so long ago scientific group from P. N. Lebedev has improved that result, the discharge gap – 1 m had been broken under KrF laser irradiation when switching high-voltage (up to 390 kV/m electric discharge by 100-ns UV pulses. Our previous result  –  16 m long conducting channel controlled by a  laser spark at the voltage  –  3 MV  – was obtained more than 20 years ago in Russia and Japan by using pulsed CO2  laser with energy  –  0,5 kJ. An average electric field strength  was < 190 kV/m. It is still too much for efficient applications.

  6. Interior point decoding for linear vector channels

    International Nuclear Information System (INIS)

    Wadayama, T

    2008-01-01

    In this paper, a novel decoding algorithm for low-density parity-check (LDPC) codes based on convex optimization is presented. The decoding algorithm, called interior point decoding, is designed for linear vector channels. The linear vector channels include many practically important channels such as inter-symbol interference channels and partial response channels. It is shown that the maximum likelihood decoding (MLD) rule for a linear vector channel can be relaxed to a convex optimization problem, which is called a relaxed MLD problem

  7. An Effective Channel Allocation Scheme to Reduce Co-Channel and Adjacent Channel Interference for WMN Backhaul

    International Nuclear Information System (INIS)

    Abbasi, S.; Ismaili, I.A.; Khuhawar, F.Y.

    2016-01-01

    Two folded work presents channel allocation scheme sustaining channel orthogonality and channel spacing to reduce CCI (Co-Channel Interference) and ACI (Adjacent Channel Interference) for inter flow of an intra-flow link. Proposed scheme as a part of radio resource allocation is applied on infrastructure based backhaul of wireless mesh network using directional antennas. The proposed approach is applied separately on 2.4 and 5GHz bands. Interference of connectivity graph is modelled by strongly connected directed graph and greedy algorithms are used for channel allocation. We have used OPNET Modeller suite to simulate network models for this research. The proposed arrangement reduces the channel interference and increases system throughput. In this research, the influence of channel is computed in terms of network throughput and delay. (author)

  8. The MISO wiretap channel with channel uncertainty: Asymptotic perspectives

    KAUST Repository

    Chaaban, Anas

    2017-05-12

    The N-antenna MISO Gaussian wiretap channel with imperfect channel-state information at the transmitter (CSIT) is studied in terms of secrecy rate scaling versus the signal-to-noise ratio (SNR) and N. Two schemes are considered, beamforming (BF) and artificial noise injection (AN). It is shown that if the CSIT error is independent of SNR, then both schemes do not achieve scaling versus SNR. However, if this error vanishes as SNR increases, then AN achieves the optimal scaling versus SNR, contrary to BF. Scaling can be achieved in BF by increasing N. In fact, BF achieves the optimal scaling versus N. In the AN scheme however, injecting noise in multiple direction deteriorates its scaling versus N. Nevertheless, AN can achieve the optimal scaling if noise is sent in only one direction. This leads to better performance than BF if the CSIT error is smaller than a threshold which is also derived.

  9. Studi Numerik Karakteristik Pengeringan Batubara pada Fluidized Bed Coal Dyer Terhadap Pengaruh Variasi Temperatur Air Heater dengan Tube Heater Tersusun Staggered dan Perbandingan Volume Chamber dan Volume Batubara Sebesar 50%

    Directory of Open Access Journals (Sweden)

    Ayu Sarah Novrizqa

    2013-03-01

    Full Text Available Indonesia mempunyai sumber daya batubara yang cukup besar dan sebagian besar sumber daya tersebut termasuk ke dalam batubara peringkat rendah berupa lignit dan sub-bituminus yang memiliki kadar air yang tinggi. Tingginya kadar air menyebabkan rendahnya nilai kalor, sehingga pemanfaatan batubara jenis ini menjadi terbatas dan sulit untuk dipasarkan. Oleh karena itu perlu adanya teknologi pengeringan yang dapat meningkatkan nilai kalor dari batubara tersebut. Dalam proses pengeringan akan melibatkan perpindahan panas dan massa. Proses ini akan didefinisikan dalam suatu studi numerik, dimana penelitian ini dilakukan dengan metode numerik dengan software Fluent 6.3.26. Pemilihan kondisi simulasi digunakan model turbulensi k-ε realizable dan skema interpolasi first-order upwind. Serta mempelajari pengaruh temperatur inlet udara pengering yang divariasikan. Variasi temperatur adalah 316 K, 327 K, 339 K. Dari penelitian ini  dapat diketahui nilai drying rate serta pengaruh temperatur dan posisi batubara dalam proses pengeringan pada drying chamber fluidized bed coal dryer dengan tube heater tersusun staggered serta pengaruh dari perbandingan volume batubara dengan volume chamber sebesar 50%. Moisture content batubara yang paling banyak berkurang dialami oleh temperature outlet terbesar yaitu 339 K dari 0,22 hingga 0,0167. Laju pengeringan yang memiliki waktu paling cepat yaitu pada temperatur 339 K, sekitar 1100 detik, sedangkan yang memiliki waktu paling lama yaitu pada temperatur 316 K, sekitar 4600 detik.

  10. The KATP channel in migraine pathophysiology

    DEFF Research Database (Denmark)

    Al-Karagholi, Mohammad Al-Mahdi; Hansen, Jakob Møller; Severinsen, Johanne

    2017-01-01

    BACKGROUND: To review the distribution and function of KATP channels, describe the use of KATP channels openers in clinical trials and make the case that these channels may play a role in headache and migraine. DISCUSSION: KATP channels are widely present in the trigeminovascular system and play...... an important role in the regulation of tone in cerebral and meningeal arteries. Clinical trials using synthetic KATP channel openers report headache as a prevalent-side effect in non-migraine sufferers, indicating that KATP channel opening may cause headache, possibly due to vascular mechanisms. Whether KATP...... channel openers can provoke migraine in migraine sufferers is not known. CONCLUSION: We suggest that KATP channels may play an important role in migraine pathogenesis and could be a potential novel therapeutic anti-migraine target....

  11. Channel Estimation in DCT-Based OFDM

    Science.gov (United States)

    Wang, Yulin; Zhang, Gengxin; Xie, Zhidong; Hu, Jing

    2014-01-01

    This paper derives the channel estimation of a discrete cosine transform- (DCT-) based orthogonal frequency-division multiplexing (OFDM) system over a frequency-selective multipath fading channel. Channel estimation has been proved to improve system throughput and performance by allowing for coherent demodulation. Pilot-aided methods are traditionally used to learn the channel response. Least square (LS) and mean square error estimators (MMSE) are investigated. We also study a compressed sensing (CS) based channel estimation, which takes the sparse property of wireless channel into account. Simulation results have shown that the CS based channel estimation is expected to have better performance than LS. However MMSE can achieve optimal performance because of prior knowledge of the channel statistic. PMID:24757439

  12. Matagorda Ship Channel, Texas: Jetty Stability Study

    National Research Council Canada - National Science Library

    Kraus, Nicholas C; Lin, Lihwa; Batten, Brian K; Brown, Gary L

    2006-01-01

    .... The current has produced a large area of scour on the bay side of the inlet adjacent to the west jetty, and vessels encountering a strong along-channel and cross-channel current at the entrance...

  13. Coastal Maintained Channels in US waters

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This layer shows coastal channels and waterways that are maintained and surveyed by the U.S. Army Corps of Engineers (USACE). These channels are necessary...

  14. Modification of single Na+ channels by batrachotoxin.

    Science.gov (United States)

    Quandt, F N; Narahashi, T

    1982-11-01

    The modifications in the properties of voltage-gated Na+ channels caused by batrachotoxin were studied by using the patch clamp method for measuring single channel currents from excised membranes of N1E-115 neuroblastoma cells. The toxin-modified open state of the Na+ channel has a decreased conductance in comparison to that of normal Na+ channels. The lifetime of the modified open state is drastically prolonged, and channels now continue to open during a maintained depolarization so that the probability of a channel being open becomes constant. Modified and normal open states of Na+ channels coexist in batrachotoxin-exposed membrane patches. Unlike the normal condition, Na+ channels exposed to batrachotoxin open spontaneously at large negative potentials. These spontaneous openings apparently cause the toxin-induced increase in Na+ permeability which, in turn, causes membrane depolarization.

  15. Targeting sodium channels in cardiac arrhythmia

    NARCIS (Netherlands)

    Remme, Carol Ann; Wilde, Arthur A. M.

    2014-01-01

    Cardiac voltage-gated sodium channels are responsible for proper electrical conduction in the heart. During acquired pathological conditions and inherited sodium channelopathies, altered sodium channel function causes conduction disturbances and ventricular arrhythmias. Although the clinical,

  16. Quantum Correlations Evolution Asymmetry in Quantum Channels

    International Nuclear Information System (INIS)

    Li Meng; Huang Yun-Feng; Guo Guang-Can

    2017-01-01

    It was demonstrated that the entanglement evolution of a specially designed quantum state in the bistochastic channel is asymmetric. In this work, we generalize the study of the quantum correlations, including entanglement and quantum discord, evolution asymmetry to various quantum channels. We found that the asymmetry of entanglement and quantum discord only occurs in some special quantum channels, and the behavior of the entanglement evolution may be quite different from the behavior of the quantum discord evolution. To quantum entanglement, in some channels it decreases monotonously with the increase of the quantum channel intensity. In some other channels, when we increase the intensity of the quantum channel, it decreases at first, then keeps zero for some time, and then rises up. To quantum discord, the evolution becomes more complex and you may find that it evolutes unsmoothly at some points. These results illustrate the strong dependence of the quantum correlations evolution on the property of the quantum channels. (paper)

  17. Channel CAT: A Tactical Link Analysis Tool

    National Research Council Canada - National Science Library

    Coleman, Michael

    1997-01-01

    .... This thesis produced an analysis tool, the Channel Capacity Analysis Tool (Channel CAT), designed to provide an automated tool for the analysis of design decisions in developing client-server software...

  18. BK channel modulators: a comprehensive overview

    DEFF Research Database (Denmark)

    Nardi, Antonio; Olesen, Søren-Peter

    2008-01-01

    The large Ca(2+)-activated K(+) channel (BK channel) reflects per excellence the dilemma of the molecular target driven drug discovery process. Significant experimental evidence suggests that the BK channels play a pivotal and specific role in many pathophysiological conditions supporting...... the notion that the channel represents an innovative and promising drug target. However, after more than ten years of intense research effort both in academia and industry, scientists have yet to witness the approval of a single BK channel modulator for clinical use. On the contrary, three BK openers...... and blockers 4) Marketed and/or investigational drugs with BK-modulating side properties and structural analogues 5) Naturally-occurring BK channel openers and structural analogues 6) Synthetic BK channel openers. This review is intended to provide readers with current opinion on the BK channel as a drug...

  19. Thermoelectricity in Heterogeneous Nanofluidic Channels.

    Science.gov (United States)

    Li, Long; Wang, Qinggong

    2018-04-19

    Ionic fluids are essential to energy conversion, water desalination, drug delivery, and lab-on-a-chip devices. Ionic transport in nanoscale confinements and complex physical fields still remain elusive. Here, a nanofluidic system is developed using nanochannels of heterogeneous surface properties to investigate transport properties of ions under different temperatures. Steady ionic currents are observed under symmetric temperature gradients, which is equivalent to generating electricity using waste heat (e.g., electronic chips and solar panels). The currents increase linearly with temperature gradient and nonlinearly with channel size. Contributions to ion motion from temperatures and channel properties are evaluated for this phenomenon. The findings provide insights into the study of confined ionic fluids in multiphysical fields, and suggest applications in thermal energy conversion, temperature sensors, and chip-level thermal management. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Radio propagation measurement and channel modelling

    CERN Document Server

    Salous, Sana

    2013-01-01

    While there are numerous books describing modern wireless communication systems that contain overviews of radio propagation and radio channel modelling, there are none that contain detailed information on the design, implementation and calibration of radio channel measurement equipment, the planning of experiments and the in depth analysis of measured data. The book would begin with an explanation of the fundamentals of radio wave propagation and progress through a series of topics, including the measurement of radio channel characteristics, radio channel sounders, measurement strategies

  1. Degenerate RFID Channel Modeling for Positioning Applications

    Directory of Open Access Journals (Sweden)

    A. Povalac

    2012-12-01

    Full Text Available This paper introduces the theory of channel modeling for positioning applications in UHF RFID. It explains basic parameters for channel characterization from both the narrowband and wideband point of view. More details are given about ranging and direction finding. Finally, several positioning scenarios are analyzed with developed channel models. All the described models use a degenerate channel, i.e. combined signal propagation from the transmitter to the tag and from the tag to the receiver.

  2. Improving Channel Coordination Through Franchising

    OpenAIRE

    Rajiv Lal

    1990-01-01

    In this paper, we explore the role of franchising arrangements in improving coordination between channel members. In particular we focus on two elements of the franchising contract, namely, the royalty structure and the monitoring technology. We begin with a simple analysis where a manufacturer distributes its product through a retailer and the retail demand is affected by the retail price and the service provided by the retailer. In this context we show that neither royalty payments nor moni...

  3. Digital Multi Channel Analyzer Enhancement

    International Nuclear Information System (INIS)

    Gonen, E.; Marcus, E.; Wengrowicz, U.; Beck, A.; Nir, J.; Sheinfeld, M.; Broide, A.; Tirosh, D.

    2002-01-01

    A cement analyzing system based on radiation spectroscopy had been developed [1], using novel digital approach for real-time, high-throughput and low-cost Multi Channel Analyzer. The performance of the developed system had a severe problem: the resulted spectrum suffered from lack of smoothness, it was very noisy and full of spikes and surges, therefore it was impossible to use this spectrum for analyzing the cement substance. This paper describes the work carried out to improve the system performance

  4. Trafficking of neuronal calcium channels

    Czech Academy of Sciences Publication Activity Database

    Weiss, Norbert; Zamponi, G. W.

    2017-01-01

    Roč. 1, č. 1 (2017), č. článku NS20160003. ISSN 2059-6553 R&D Projects: GA ČR GA15-13556S; GA MŠk 7AMB15FR015 Institutional support: RVO:61388963 Keywords : calcium channel * neuron * trafficing Subject RIV: ED - Physiology OBOR OECD: Physiology (including cytology) http://www. neuron alsignaling.org/content/1/1/NS20160003

  5. Muon decay channeling in silicon

    International Nuclear Information System (INIS)

    Bosshard, A.; Patterson, B.D.; Straumann, U.; Truoel, P.; Wichert, Th.

    1984-01-01

    This experiment employs the channeling effect of the host lattice on the trajectories of decay positrons in order to determine the position of positive muons implanted into silicon crystals. Low-momentum ( 0 ). In order to achieve sufficient angular resolution, the Si wafer is bent to a spherical shape, thereby focussing a particular crystal axis to a point at the center of the MWPC (located 3.4 m from the wafer). (Auth.)

  6. Local Transfer Coefficient, Smooth Channel

    Directory of Open Access Journals (Sweden)

    R. T. Kukreja

    1998-01-01

    Full Text Available Naphthalene sublimation technique and the heat/mass transfer analogy are used to determine the detailed local heat/mass transfer distributions on the leading and trailing walls of a twopass square channel with smooth walls that rotates about a perpendicular axis. Since the variation of density is small in the flow through the channel, buoyancy effect is negligible. Results show that, in both the stationary and rotating channel cases, very large spanwise variations of the mass transfer exist in he turn and in the region immediately downstream of the turn in the second straight pass. In the first straight pass, the rotation-induced Coriolis forces reduce the mass transfer on the leading wall and increase the mass transfer on the trailing wall. In the turn, rotation significantly increases the mass transfer on the leading wall, especially in the upstream half of the turn. Rotation also increases the mass transfer on the trailing wall, more in the downstream half of the turn than in the upstream half of the turn. Immediately downstream of the turn, rotation causes the mass transfer to be much higher on the trailing wall near the downstream corner of the tip of the inner wall than on the opposite leading wall. The mass transfer in the second pass is higher on the leading wall than on the trailing wall. A slower flow causes higher mass transfer enhancement in the turn on both the leading and trailing walls.

  7. 47 CFR 95.29 - Channels available.

    Science.gov (United States)

    2010-10-01

    ... no more than 5 watts ERP. (g) Fixed stations in GMRS systems authorized before March 18, 1968... transmission of another GMRS station on a different channel or channels), the licensee of the GMRS system must... GMRS system from the following 462 MHz channels: 462.5500, 462.5750, 462.6000, 462.6250, 462.6500, 462...

  8. Modulation of ERG channels by XE991

    DEFF Research Database (Denmark)

    Elmedyb, Pernille; Calloe, Kirstine; Schmitt, Nicole

    2007-01-01

    In neuronal tissue, KCNQ2-5 channels conduct the physiologically important M-current. In some neurones, the M-current may in addition be conducted partly by ERG potassium channels, which have widely overlapping expression with the KCNQ channel subunits. XE991 and linopiridine are known to be stan...

  9. Electronic Commerce and Retail Channel Substitution

    NARCIS (Netherlands)

    M.C.W. Janssen (Maarten); R. van der Noll

    2002-01-01

    textabstractWe analyze a market where firms compete in a conventional and an electronic retail channel. Consumers easily compare prices online, but some incur purchase uncertainties on the online channel. We investigate the market shares of the two retail channels and the prices that are charged. We

  10. Molecular determinants in TRPV5 channel assembly.

    NARCIS (Netherlands)

    Chang, Q.; Gyftogianni, E.; Graaf, K.F.J. van de; Hoefs, S.J.G.; Weidema, A.F.; Bindels, R.J.M.; Hoenderop, J.G.J.

    2004-01-01

    The epithelial Ca(2+) channels TRPV5 and TRPV6 mediate the Ca(2+) influx in 1,25-dihydroxyvitamin D(3)-responsive epithelia and are therefore essential in the maintenance of the body Ca(2+) balance. These Ca(2+) channels assemble in (hetero)tetrameric channel complexes with different functional

  11. Molecular determinants in TRPV5 channel assembly

    NARCIS (Netherlands)

    Chang, Qing; Gyftogianni, Emmanouela; van de Graaf, Stan F. J.; Hoefs, Susan; Weidema, Freek A.; Bindels, René J. M.; Hoenderop, Joost G. J.

    2004-01-01

    The epithelial Ca(2+) channels TRPV5 and TRPV6 mediate the Ca(2+) influx in 1,25-dihydroxyvitamin D(3)-responsive epithelia and are therefore essential in the maintenance of the body Ca(2+) balance. These Ca(2+) channels assemble in (hetero)tetrameric channel complexes with different functional

  12. The use of service channels by citizens in the Netherlands: implications for multi-channel management

    NARCIS (Netherlands)

    Pieterson, Willem Jan; Ebbers, Wolfgang E.

    2008-01-01

    Many governmental organizations are changing their service channel management strategies to multi-channel management. However, very few empirical studies exist that explore how these multi-channel strategies should be shaped. In this article we test a number of hypotheses on citizens' channel use

  13. Channel discrimination power of bipartite quantum states

    Science.gov (United States)

    Caiaffa, Matteo; Piani, Marco

    2018-03-01

    We quantify the usefulness of a bipartite quantum state in the ancilla-assisted channel discrimination of arbitrary quantum channels, formally defining a worst-case-scenario channel discrimination power for bipartite quantum states. We show that such a quantifier is deeply connected with the operator Schmidt decomposition of the state. We compute the channel discrimination power exactly for pure states, and provide upper and lower bounds for general mixed states. We show that highly entangled states can outperform any state that passes the realignment criterion for separability and that the channel discrimination power of a state is bounded by its quantum discord.

  14. BKCa-Channel Structure and Function

    Science.gov (United States)

    Cox, Daniel H.

    Among ion channels, the large-conductance Ca2+-activated K+ channel (BKCa channel) is in many ways unique. It has a very large single-channel conductance—ten times that of most vertebrate K+ channels—and yet it maintains strict K+ selectivity. It senses as little as 200 nM Ca2+, but it contains no consensus Ca2+-binding motifs, and it is the only channel to be activated by both intracellular Ca2+ and membrane voltage. In fact, there is a synergy between these stimuli such that the higher the internal Ca2+ concentration ([Ca2+]), the smaller the depolarization needed to activate the channel. Furthermore, the BKCa channel has its own brand of auxiliary subunits that profoundly affect gating. In this chapter, I will discuss what is understood about the origins of these properties in terms of allosteric models and channel structure. At the outset, however, I should say that there is not yet a crystal structure of the BKCa channel or any of its components, so much of the current thinking about BKCa-channel structure relies on analogy to other channels.

  15. Performance Analysis of Iterative Channel Estimation and Multiuser Detection in Multipath DS-CDMA Channels

    OpenAIRE

    Li, Husheng; Betz, Sharon M.; Poor, H. Vincent

    2006-01-01

    This paper examines the performance of decision feedback based iterative channel estimation and multiuser detection in channel coded aperiodic DS-CDMA systems operating over multipath fading channels. First, explicit expressions describing the performance of channel estimation and parallel interference cancellation based multiuser detection are developed. These results are then combined to characterize the evolution of the performance of a system that iterates among channel estimation, multiu...

  16. On luminescence bleaching of tidal channel sediments

    DEFF Research Database (Denmark)

    Fruergaard, Mikkel; Pejrup, Morten; Murray, Andrew S.

    2015-01-01

    We investigate the processes responsible for bleaching of the quartz OSL signal from tidal channel sediment. Tidal dynamics are expected to play an important role for complete bleaching of tidal sediments. However, no studies have examined the amount of reworking occurring in tidal channels...... and on tidal flats due to the mixing caused by currents and waves. We apply bed level data to evaluate the amount of vertical sediment reworking in modern tidal channels and at a tidal flat. Cycles of deposition and erosion are measured with a bed level sensor, and the results show that gross sedimentation...... was several times higher than net sedimentation. We propose that tidal channel sediment is bleached either on the tidal flat before it is transported to the tidal channels and incorporated in channel-fill successions or, alternatively, on the shallow intertidal part of the channel banks. Based...

  17. Post-Translational Modifications of TRP Channels

    Directory of Open Access Journals (Sweden)

    Olaf Voolstra

    2014-04-01

    Full Text Available Transient receptor potential (TRP channels constitute an ancient family of cation channels that have been found in many eukaryotic organisms from yeast to human. TRP channels exert a multitude of physiological functions ranging from Ca2+ homeostasis in the kidney to pain reception and vision. These channels are activated by a wide range of stimuli and undergo covalent post-translational modifications that affect and modulate their subcellular targeting, their biophysical properties, or channel gating. These modifications include N-linked glycosylation, protein phosphorylation, and covalent attachment of chemicals that reversibly bind to specific cysteine residues. The latter modification represents an unusual activation mechanism of ligand-gated ion channels that is in contrast to the lock-and-key paradigm of receptor activation by its agonists. In this review, we summarize the post-translational modifications identified on TRP channels and, when available, explain their physiological role.

  18. Clay mineral variations near Pennsylvanian sandstone channels

    International Nuclear Information System (INIS)

    Shaffer, N.R.; Indiana Univ., Bloomington, IN; Murray, H.H.

    1993-01-01

    Large linear sandstone bodies in the Illinois Basin have been interpreted as representing fresh water river channels that flowed through generally marine to brackish Pennsylvanian deltaic environments; fresh water from such channels could have affected deposition of adjacent coal-bearing rocks. Low-sulfur coals are commonly associated with the sandstone bodies, which may also host petroleum, uranium, fresh water, or other resources. Thus techniques to locate such channels would be economically useful. Previous studies have shown that clay mineral distributions and bulk chemistries of clay-rich sediments are affected when fresh waters mix with sea water. Such changes associated laterally with freshwater channels might have caused distinctive clay mineral or chemical patterns to develop around the channels. Mineralogies and chemical compositions of more than 500 mudrock samples taken immediately above the springfield Coal Member of the Petersburg Formation from 52 sections located from channel margins to 63 miles distant were determined to discern patterns that could aid in finding channels

  19. A BWR fuel channel tracking system

    International Nuclear Information System (INIS)

    Reynolds, R.S.

    1987-01-01

    A relational database management system with a query language, Reference 1, has been used to develop a Boiling Water Reactor (BWR) fuel channel tracking system on a microcomputer. The software system developed implements channel vendor and Nuclear Regulatory Commission recommendations for in-core channel movements between reactor operating cycles. A BWR Fuel channel encloses the fuel bundle and is typically fabricated using Ziracoly-4. The channel serves three functions: (1) it provides a barrier to separate two parallel flow paths, one inside the fuel assembly and the other in the bypass region outside the fuel assembly and between channels; (2) it guides the control rod as it moves between fuel assemblies and provides a bearing surface for the blades; and (3) it provides rigidity for the fuel bundle. All of these functions are necessary in typical BWR core designs. Fuel channels are not part of typical Pressurized Water Reactor (PWR) core designs

  20. BK channel modulators: a comprehensive overview

    DEFF Research Database (Denmark)

    Nardi, Antonio; Olesen, Søren-Peter

    2008-01-01

    channels as a potentially attractive target, the design and synthesis of potent and selective BK modulators continue based on novel chemical ideas. A comprehensive overview of BK channel modulators is therefore timely and important to the current medicinal chemist for review, summary, and classification......The large Ca(2+)-activated K(+) channel (BK channel) reflects per excellence the dilemma of the molecular target driven drug discovery process. Significant experimental evidence suggests that the BK channels play a pivotal and specific role in many pathophysiological conditions supporting...... the notion that the channel represents an innovative and promising drug target. However, after more than ten years of intense research effort both in academia and industry, scientists have yet to witness the approval of a single BK channel modulator for clinical use. On the contrary, three BK openers...

  1. Vortex dynamics behind a self-oscillating inverted flag placed in a channel flow: Time-resolved particle image velocimetry measurements

    Science.gov (United States)

    Yu, Yuelong; Liu, Yingzheng; Chen, Yujia

    2017-12-01

    The unsteady flow behind an inverted flag placed in a water channel and then excited into a self-oscillating state is measured using time-resolved particle image velocimetry. The dynamically deformed profiles of the inverted flag are determined by a novel algorithm that combines morphological image processing and principle component analysis. Three modes are discovered with the successive decrease in the dimensionless bending stiffness: the biased mode, the flapping mode, and the deflected mode. The distinctly different flow behavior is discussed in terms of instantaneous velocity field, phase-averaged vorticity field, time-mean flow field, and turbulent kinetic energy. The results demonstrated that the biased mode generated abundant vortices at the oscillating side of the inverted flag. In the deflected mode, the inverted flag is highly deflected to one side of the channel and remains almost stationary, inducing two stable recirculation zones and a considerably inversed flow between them. In the flapping mode, the strongly oscillating flag periodically provides a strengthened influence on the fluid near the two sidewalls. The reverse von Kármán vortex street is well formed and energetic in the wake, and a series of high-speed impingement jets between the neighboring vortices are directed toward the sidewalls in a staggered fashion.

  2. Multicarrier chaotic communications in multipath fading channels without channel estimation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shilian, E-mail: wangsl@nudt.edu.cn; Zhang, Zhili [College of Electrical Science and Engineering, National University of Defense Technology, Changsha, 410073, P R China (China)

    2015-01-15

    A multi-carrier chaotic shift keying(MC-CSK) communication scheme with low probability of interception(LPI) is proposed in this article. We apply chaotic spreading sequences in the frequency domain, mapping a different chip of a chaotic sequence to an individual orthogonal frequency division multiplexing(OFDM) subcarrier. In each block size of $M$ OFDM symbols, we use one pilot OFDM symbol inserted time-spaced in all-frequency to transmit the reference chaotic signal and use the other M-1 OFDM symbols to transmit the information-bearing signals each spreaded by the reference chaotic signal. At the receiver, we construct a differential detector after DFT and recover the information bits from the correlations between the pilot OFDM symbol and the other M-1 OFDM symbols in each block size of M. Performance analysis and computer simulations show that the MC-CSK outperforms differential chaos shift keying(DCSK) in AWGN channels with high bandwidth efficiency for the block size of M=2 and that the MC-CSK exploits effectively the frequent diversity of the multipath channel.

  3. Multicarrier chaotic communications in multipath fading channels without channel estimation

    International Nuclear Information System (INIS)

    Wang, Shilian; Zhang, Zhili

    2015-01-01

    A multi-carrier chaotic shift keying(MC-CSK) communication scheme with low probability of interception(LPI) is proposed in this article. We apply chaotic spreading sequences in the frequency domain, mapping a different chip of a chaotic sequence to an individual orthogonal frequency division multiplexing(OFDM) subcarrier. In each block size of $M$ OFDM symbols, we use one pilot OFDM symbol inserted time-spaced in all-frequency to transmit the reference chaotic signal and use the other M-1 OFDM symbols to transmit the information-bearing signals each spreaded by the reference chaotic signal. At the receiver, we construct a differential detector after DFT and recover the information bits from the correlations between the pilot OFDM symbol and the other M-1 OFDM symbols in each block size of M. Performance analysis and computer simulations show that the MC-CSK outperforms differential chaos shift keying(DCSK) in AWGN channels with high bandwidth efficiency for the block size of M=2 and that the MC-CSK exploits effectively the frequent diversity of the multipath channel

  4. Effect of the Presence of Semi-circular Cylinders on Heat Transfer From Heat Sources Placed in Two Dimensional Channel

    Directory of Open Access Journals (Sweden)

    Ahmed W. Mustava

    2013-04-01

    Full Text Available The effect of a semi-circular cylinders in a two dimensional channel on heat transfer by forced convection from two heat sources with a constant temperature has been studied numerically. Each channel contains two heat sources; one on the upper surface of the channel and the other on the lower surface of the channel. There is semi-circular cylinder under the source in upper surface and there is semi-circular cylinder above the source in lower surface. The location of the second heat source with its semi-cylinder has been changed and keeps the first source with its semi- cylinder at the same location. The flow and temperature field are studied numerically with different values of Reynolds numbers and for different spacing between the centers of the semi-cylinders. The laminar flow field is analyzed numerically by solving the steady forms of the two-dimensional incompressible Navier- Stokes and energy equations.  The Cartesian velocity components and pressure on a collocated (non-staggered grid are used as dependent variables in the momentum equations, which discretized by finite volume method, body fitted coordinates are used to represent the complex channel geometry accurately, and grid generation technique based on elliptic partial differential equations is employed. SIMPLE algorithm is used to adjust the velocity field to satisfy the conservation of mass.  The range of Reynolds number is (Re= 100 – 800 and the range of the spacing between the semi-cylinders is(1-4 and the Prandtl number is 0.7.The results showed that increasing the spacing between the semi-cylinders increases the average of Nusselt number of the first heat source for all Reynolds numbers. As well as the results show that the best case among the cases studied to enhance the heat transfer is when the second heat source and its semi-cylinder located on at the distance (S=1.5 from the first half of the cylinder and the Reynolds number is greater than (Re ≥ 400 because of the

  5. An improved pseudotargeted metabolomics approach using multiple ion monitoring with time-staggered ion lists based on ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry

    International Nuclear Information System (INIS)

    Wang, Yang; Liu, Fang; Li, Peng; He, Chengwei; Wang, Ruibing; Su, Huanxing; Wan, Jian-Bo

    2016-01-01

    Pseudotargeted metabolomics is a novel strategy integrating the advantages of both untargeted and targeted methods. The conventional pseudotargeted metabolomics required two MS instruments, i.e., ultra-high performance liquid chromatography/quadrupole-time- of-flight mass spectrometry (UHPLC/Q-TOF MS) and UHPLC/triple quadrupole mass spectrometry (UHPLC/QQQ-MS), which makes method transformation inevitable. Furthermore, the picking of ion pairs from thousands of candidates and the swapping of the data between two instruments are the most labor-intensive steps, which greatly limit its application in metabolomic analysis. In the present study, we proposed an improved pseudotargeted metabolomics method that could be achieved on an UHPLC/Q-TOF/MS instrument operated in the multiple ion monitoring (MIM) mode with time-staggered ion lists (tsMIM). Full scan-based untargeted analysis was applied to extract the target ions. After peak alignment and ion fusion, a stepwise ion picking procedure was used to generate the ion lists for subsequent single MIM and tsMIM. The UHPLC/Q-TOF tsMIM MS-based pseudotargeted approach exhibited better repeatability and a wider linear range than the UHPLC/Q-TOF MS-based untargeted metabolomics method. Compared to the single MIM mode, the tsMIM significantly increased the coverage of the metabolites detected. The newly developed method was successfully applied to discover plasma biomarkers for alcohol-induced liver injury in mice, which indicated its practicability and great potential in future metabolomics studies. - Highlights: • An UHPLC/Q-TOF tsMIM MS-based pseudotargeted metabolomics was proposed. • Compared to full scan, the improved method exhibits better repeatability and a wider linear range. • The proposed method could achieve pseudotargeted analysis on one UHPLC/Q-TOF/MS instrument. • The developed method was successfully used to discover biomarkers for alcohol-induced liver injury.

  6. An improved pseudotargeted metabolomics approach using multiple ion monitoring with time-staggered ion lists based on ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Wang, Yang; Liu, Fang; Li, Peng; He, Chengwei; Wang, Ruibing; Su, Huanxing; Wan, Jian-Bo

    2016-07-13

    Pseudotargeted metabolomics is a novel strategy integrating the advantages of both untargeted and targeted methods. The conventional pseudotargeted metabolomics required two MS instruments, i.e., ultra-high performance liquid chromatography/quadrupole-time- of-flight mass spectrometry (UHPLC/Q-TOF MS) and UHPLC/triple quadrupole mass spectrometry (UHPLC/QQQ-MS), which makes method transformation inevitable. Furthermore, the picking of ion pairs from thousands of candidates and the swapping of the data between two instruments are the most labor-intensive steps, which greatly limit its application in metabolomic analysis. In the present study, we proposed an improved pseudotargeted metabolomics method that could be achieved on an UHPLC/Q-TOF/MS instrument operated in the multiple ion monitoring (MIM) mode with time-staggered ion lists (tsMIM). Full scan-based untargeted analysis was applied to extract the target ions. After peak alignment and ion fusion, a stepwise ion picking procedure was used to generate the ion lists for subsequent single MIM and tsMIM. The UHPLC/Q-TOF tsMIM MS-based pseudotargeted approach exhibited better repeatability and a wider linear range than the UHPLC/Q-TOF MS-based untargeted metabolomics method. Compared to the single MIM mode, the tsMIM significantly increased the coverage of the metabolites detected. The newly developed method was successfully applied to discover plasma biomarkers for alcohol-induced liver injury in mice, which indicated its practicability and great potential in future metabolomics studies. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. An improved pseudotargeted metabolomics approach using multiple ion monitoring with time-staggered ion lists based on ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yang; Liu, Fang; Li, Peng; He, Chengwei; Wang, Ruibing; Su, Huanxing; Wan, Jian-Bo, E-mail: jbwan@umac.mo

    2016-07-13

    Pseudotargeted metabolomics is a novel strategy integrating the advantages of both untargeted and targeted methods. The conventional pseudotargeted metabolomics required two MS instruments, i.e., ultra-high performance liquid chromatography/quadrupole-time- of-flight mass spectrometry (UHPLC/Q-TOF MS) and UHPLC/triple quadrupole mass spectrometry (UHPLC/QQQ-MS), which makes method transformation inevitable. Furthermore, the picking of ion pairs from thousands of candidates and the swapping of the data between two instruments are the most labor-intensive steps, which greatly limit its application in metabolomic analysis. In the present study, we proposed an improved pseudotargeted metabolomics method that could be achieved on an UHPLC/Q-TOF/MS instrument operated in the multiple ion monitoring (MIM) mode with time-staggered ion lists (tsMIM). Full scan-based untargeted analysis was applied to extract the target ions. After peak alignment and ion fusion, a stepwise ion picking procedure was used to generate the ion lists for subsequent single MIM and tsMIM. The UHPLC/Q-TOF tsMIM MS-based pseudotargeted approach exhibited better repeatability and a wider linear range than the UHPLC/Q-TOF MS-based untargeted metabolomics method. Compared to the single MIM mode, the tsMIM significantly increased the coverage of the metabolites detected. The newly developed method was successfully applied to discover plasma biomarkers for alcohol-induced liver injury in mice, which indicated its practicability and great potential in future metabolomics studies. - Highlights: • An UHPLC/Q-TOF tsMIM MS-based pseudotargeted metabolomics was proposed. • Compared to full scan, the improved method exhibits better repeatability and a wider linear range. • The proposed method could achieve pseudotargeted analysis on one UHPLC/Q-TOF/MS instrument. • The developed method was successfully used to discover biomarkers for alcohol-induced liver injury.

  8. Conductive Channel for Energy Transmission

    Science.gov (United States)

    Apollonov, Victor V.

    2011-11-01

    For many years the attempts to create conductive channels of big length were taken in order to study the upper atmosphere and to settle special tasks, related to energy transmission. There upon the program of creation of "Impulsar" represents a great interest, as this program in a combination with high-voltage high repetition rate electrical source can be useful to solve the above mentioned problems (N. Tesla ideas for the days of high power lasers). The principle of conductive channel production can be shortly described as follows. The "Impulsar"—laser jet engine vehicle—propulsion take place under the influence of powerful high repetition rate pulse-periodic laser radiation. In the experiments the CO2—laser and solid state Nd:YAG laser systems had been used. Active impulse appears thanks to air breakdown (30 km), placed in the vicinity of the focusing mirror-acceptor of the breakdown waves. With each pulse of powerful laser the device rises up, leaving a bright and dense trace of products with high degree of ionization and metallization by conductive nano-particles due to ablation. Conductive dust plasma properties investigation in our experiments was produced by two very effective approaches: high power laser controlled ablation and by explosion of wire. Experimental and theoretical results of conductive canal modeling will be presented. The estimations show that with already experimentally demonstrated figures of specific thrust impulse the lower layers of the Ionosphere can be reached in several ten seconds that is enough to keep the high level of channel conductivity and stability with the help of high repetition rate high voltage generator. Some possible applications for new technology are highlighted.

  9. Precipitation patterns during channel flow

    Science.gov (United States)

    Jamtveit, B.; Hawkins, C.; Benning, L. G.; Meier, D.; Hammer, O.; Angheluta, L.

    2013-12-01

    Mineral precipitation during channelized fluid flow is widespread in a wide variety of geological systems. It is also a common and costly phenomenon in many industrial processes that involve fluid flow in pipelines. It is often referred to as scale formation and encountered in a large number of industries, including paper production, chemical manufacturing, cement operations, food processing, as well as non-renewable (i.e. oil and gas) and renewable (i.e. geothermal) energy production. We have studied the incipient stages of growth of amorphous silica on steel plates emplaced into the central areas of the ca. 1 meter in diameter sized pipelines used at the hydrothermal power plant at Hellisheidi, Iceland (with a capacity of ca 300 MW electricity and 100 MW hot water). Silica precipitation takes place over a period of ca. 2 months at approximately 120°C and a flow rate around 1 m/s. The growth produces asymmetric ca. 1mm high dendritic structures ';leaning' towards the incoming fluid flow. A novel phase-field model combined with the lattice Boltzmann method is introduced to study how the growth morphologies vary under different hydrodynamic conditions, including non-laminar systems with turbulent mixing. The model accurately predicts the observed morphologies and is directly relevant for understanding the more general problem of precipitation influenced by turbulent mixing during flow in channels with rough walls and even for porous flow. Reference: Hawkins, C., Angheluta, L., Hammer, Ø., and Jamtveit, B., Precipitation dendrites in channel flow. Europhysics Letters, 102, 54001

  10. Propagation Characterization and MIMO Channel-Modelling for 3G

    DEFF Research Database (Denmark)

    Schumacher, Laurent; Berger, Lars Torsten; Ramiro-Moreno, Juan

    2004-01-01

    This paper presents a survey of MIMO channel models, distinguishing between determinsistic and stochastic channel models.......This paper presents a survey of MIMO channel models, distinguishing between determinsistic and stochastic channel models....

  11. Flexible linings for drainage channels

    Energy Technology Data Exchange (ETDEWEB)

    Crowhurst, A.D.

    1984-12-01

    Watercourses formed in fill areas present special problems. Since soils may not be fully compacted erosion may occur to a greater degree than would otherwise be the case. Rigid structures built under these conditions may well fail due to settlement or to scour from flows passing under the structure. Concrete may well also be more obtrusive in rural landscapes. An alternative exists in the form of thin layers of wire enclosed rip-rap which have several advantages when used for channel linings. This method gives both strength and economy coupled with a natural appearance.

  12. Mechanosensitive gating of Kv channels.

    Directory of Open Access Journals (Sweden)

    Catherine E Morris

    Full Text Available K-selective voltage-gated channels (Kv are multi-conformation bilayer-embedded proteins whose mechanosensitive (MS Popen(V implies that at least one conformational transition requires the restructuring of the channel-bilayer interface. Unlike Morris and colleagues, who attributed MS-Kv responses to a cooperative V-dependent closed-closed expansion↔compaction transition near the open state, Mackinnon and colleagues invoke expansion during a V-independent closed↔open transition. With increasing membrane tension, they suggest, the closed↔open equilibrium constant, L, can increase >100-fold, thereby taking steady-state Popen from 0→1; "exquisite sensitivity to small…mechanical perturbations", they state, makes a Kv "as much a mechanosensitive…as…a voltage-dependent channel". Devised to explain successive gK(V curves in excised patches where tension spontaneously increased until lysis, their L-based model falters in part because of an overlooked IK feature; with recovery from slow inactivation factored in, their g(V datasets are fully explained by the earlier model (a MS V-dependent closed-closed transition, invariant L≥4. An L-based MS-Kv predicts neither known Kv time courses nor the distinctive MS responses of Kv-ILT. It predicts Kv densities (hence gating charge per V-sensor several-fold different from established values. If opening depended on elevated tension (L-based model, standard gK(V operation would be compromised by animal cells' membrane flaccidity. A MS V-dependent transition is, by contrast, unproblematic on all counts. Since these issues bear directly on recent findings that mechanically-modulated Kv channels subtly tune pain-related excitability in peripheral mechanoreceptor neurons we undertook excitability modeling (evoked action potentials. Kvs with MS V-dependent closed-closed transitions produce nuanced mechanically-modulated excitability whereas an L-based MS-Kv yields extreme, possibly excessive

  13. Use of navigation channels by Lake Sturgeon: Does channelization increase vulnerability of fish to ship strikes?

    Directory of Open Access Journals (Sweden)

    Darryl W Hondorp

    Full Text Available Channelization for navigation and flood control has altered the hydrology and bathymetry of many large rivers with unknown consequences for fish species that undergo riverine migrations. In this study, we investigated whether altered flow distributions and bathymetry associated with channelization attracted migrating Lake Sturgeon (Acipenser fulvescens into commercial navigation channels, potentially increasing their exposure to ship strikes. To address this question, we quantified and compared Lake Sturgeon selection for navigation channels vs. alternative pathways in two multi-channel rivers differentially affected by channelization, but free of barriers to sturgeon movement. Acoustic telemetry was used to quantify Lake Sturgeon movements. Under the assumption that Lake Sturgeon navigate by following primary flow paths, acoustic-tagged Lake Sturgeon in the more-channelized lower Detroit River were expected to choose navigation channels over alternative pathways and to exhibit greater selection for navigation channels than conspecifics in the less-channelized lower St. Clair River. Consistent with these predictions, acoustic-tagged Lake Sturgeon in the more-channelized lower Detroit River selected the higher-flow and deeper navigation channels over alternative migration pathways, whereas in the less-channelized lower St. Clair River, individuals primarily used pathways alternative to navigation channels. Lake Sturgeon selection for navigation channels as migratory pathways also was significantly higher in the more-channelized lower Detroit River than in the less-channelized lower St. Clair River. We speculated that use of navigation channels over alternative pathways would increase the spatial overlap of commercial vessels and migrating Lake Sturgeon, potentially enhancing their vulnerability to ship strikes. Results of our study thus demonstrated an association between channelization and the path use of migrating Lake Sturgeon that could prove

  14. Pauli diagonal channels constant on axes

    Energy Technology Data Exchange (ETDEWEB)

    Nathanson, Michael [Department of Mathematics and Computer Science, St. Mary' s College of California, Moraga, CA 94575 (United States); Ruskai, Mary Beth [Department of Mathematics, Tufts University, Medford, MA 02155 (United States)

    2007-07-13

    We define and study the properties of channels which are analogous to unital qubit channels in several ways. A full treatment can be given only when the dimension d = p{sup m} a prime power, in which case each of the d + 1 mutually unbiased bases (MUB) defines an axis. Along each axis the channel looks like a depolarizing channel, but the degree of depolarization depends on the axis. When d is not a prime power, some of our results still hold, particularly in the case of channels with one symmetry axis. We describe the convex structure of this class of channels and the subclass of entanglement breaking channels. We find new bound entangled states for d = 3. For these channels, we show that the multiplicativity conjecture for maximal output p-norm holds for p = 2. We also find channels with behaviour not exhibited by unital qubit channels, including two pairs of orthogonal bases with equal output entropy in the absence of symmetry. This provides new numerical evidence for the additivity of minimal output entropy.

  15. VKCDB: Voltage-gated potassium channel database

    Directory of Open Access Journals (Sweden)

    Gallin Warren J

    2004-01-01

    Full Text Available Abstract Background The family of voltage-gated potassium channels comprises a functionally diverse group of membrane proteins. They help maintain and regulate the potassium ion-based component of the membrane potential and are thus central to many critical physiological processes. VKCDB (Voltage-gated potassium [K] Channel DataBase is a database of structural and functional data on these channels. It is designed as a resource for research on the molecular basis of voltage-gated potassium channel function. Description Voltage-gated potassium channel sequences were identified by using BLASTP to search GENBANK and SWISSPROT. Annotations for all voltage-gated potassium channels were selectively parsed and integrated into VKCDB. Electrophysiological and pharmacological data for the channels were collected from published journal articles. Transmembrane domain predictions by TMHMM and PHD are included for each VKCDB entry. Multiple sequence alignments of conserved domains of channels of the four Kv families and the KCNQ family are also included. Currently VKCDB contains 346 channel entries. It can be browsed and searched using a set of functionally relevant categories. Protein sequences can also be searched using a local BLAST engine. Conclusions VKCDB is a resource for comparative studies of voltage-gated potassium channels. The methods used to construct VKCDB are general; they can be used to create specialized databases for other protein families. VKCDB is accessible at http://vkcdb.biology.ualberta.ca.

  16. A Perspective on the MIMO Wiretap Channel

    KAUST Repository

    Oggier, Frederique

    2015-10-01

    A wiretap channel is a communication channel between a transmitter Alice and a legitimate receiver Bob, in the presence of an eavesdropper Eve. The goal of communication is to achieve reliability between Alice and Bob, but also confidentiality despite Eve’s presence. Wiretap channels are declined in all kinds of flavors, depending on the underlying channels used by the three players: discrete memoryless channels, additive Gaussian noise channels, or fading channels, to name a few. In this survey, we focus on the case where the three players use multiple-antenna channels with Gaussian noise to communicate. After summarizing known results for multiple-input–multiple-output (MIMO) channels, both in terms of achievable reliable data rate (capacity) and code design, we introduce the MIMO wiretap channel. We then state the MIMO wiretap capacity, summarize the idea of the proof(s) behind this result, and comment on the insights given by the proofs on the physical meaning of the secrecy capacity. We finally discuss design criteria for MIMO wiretap codes.

  17. Quantum circuits for quantum channels

    Science.gov (United States)

    Iten, Raban; Colbeck, Roger; Christandl, Matthias

    2017-05-01

    We study the implementation of quantum channels with quantum computers while minimizing the experimental cost, measured in terms of the number of controlled-not (cnot) gates required (single-qubit gates are free). We consider three different models. In the first, the quantum circuit model (QCM), we consider sequences of single-qubit and cnot gates and allow qubits to be traced out at the end of the gate sequence. In the second (RandomQCM), we also allow external classical randomness. In the third (MeasuredQCM) we also allow measurements followed by operations that are classically controlled on the outcomes. We prove lower bounds on the number of cnot gates required and give near-optimal decompositions in almost all cases. Our main result is a MeasuredQCM circuit for any channel from m qubits to n qubits that uses at most one ancilla and has a low cnot count. We give explicit examples for small numbers of qubits that provide the lowest known cnot counts.

  18. Stable channel of reclaimed tidal lowland

    Science.gov (United States)

    Syarifudin, Achmad; Imanuddin, Momon S.; Moerwanto, Arie S.; Suryadi, F. X.

    2017-11-01

    This study aimed to develop models of the Operation and Maintenance in the reclaimed tidal marsh area to get a stable channel. The research location is reclaimed tidal delta area Telang I Primary 8 representing land typology A/B and a survey conducted in 13 South Secondary Schemes following existing tertiary Telang I. MIKE - 11 computer models used used to analyze the movement of sediment in the channel in both the Primary channel 8, SPD, SDU and tertiary channels in block 13 South. Calibration model with multiple channels in the field of physical parameters has been performed to obtain results close to the results of measurement modeling sediment movement in the channel. The integration models of MIKE - 11 models with various scenarios are used to model the operation and maintenance of the channel in the tidal marsh area to get a stable channel. According to the scheme P8 - 13S, OM models obtained 75 percent, in which the secondary channel (SPD/SDU) and built flap gate in tertiary channel, get a well prototype model of the stable channel (equilibriums), where the average erosion on P8 at a distance of 3,200 m in the amount of 4,472,049 m3 and the mean sedimentation in the SPD of 963,836 m3 and mean of sedimentation in the tertiary channel of 3,508,213 m3. Similarly, on average erosion P8 by 4,135,649 m3 and the mean sedimentation in the SDU of 681,304 m3 and the mean sedimentation in the tertiary channel of 3,454,345 m3.

  19. What controls sediment flux in dryland channels?

    Science.gov (United States)

    Michaelides, K.; Singer, M. B.

    2010-12-01

    Theories for the development of longitudinal and grain size profiles in perennial fluvial systems are well developed, allowing for generalization of sediment flux and sorting in these fluvial systems over decadal to millennial time scales under different forcings (e.g., sediment supply, climate changes, etc). However, such theoretical frameworks are inadequate for understanding sediment flux in dryland channels subject to spatially and temporally discontinuous streamflow, where transport capacity is usually much lower than sediment supply. In such fluvial systems, channel beds are poorly sorted with weak vertical layering, poorly defined bar forms, minimal downstream fining, and straight longitudinal profiles. Previous work in dryland channels has documented sediment flux at higher rates than their humid counterparts once significant channel flow develops, pulsations in bed material transport under constant discharge, and oscillations in dryland channel width that govern longitudinal patterns in erosion and deposition. These factors point to less well appreciated controls on sediment flux in dryland valley floors that invite further study. This paper investigates the relative roles of hydrology, bed material grain size, and channel width on sediment flux rates in the Rambla de Nogalte in southeastern Spain. Topographic valley cross sections and hillslope and channel particle sizes were collected from an ephemeral-river reach. Longitudinal grain-size variation on the hillslopes and on the channel bed were analysed in order to determine the relationship between hillslope supply characteristics and channel grain-size distribution and longitudinal changes. Local fractional estimates of bed-material transport in the channel were calculated using a range of channel discharge scenarios in order to examine the effect of channel hydrology on sediment transport. Numerical modelling was conducted to investigate runoff connectivity from hillslopes to channel and to examine the

  20. Pore size matters for potassium channel conductance

    Science.gov (United States)

    Moldenhauer, Hans; Pincuntureo, Matías

    2016-01-01

    Ion channels are membrane proteins that mediate efficient ion transport across the hydrophobic core of cell membranes, an unlikely process in their absence. K+ channels discriminate K+ over cations with similar radii with extraordinary selectivity and display a wide diversity of ion transport rates, covering differences of two orders of magnitude in unitary conductance. The pore domains of large- and small-conductance K+ channels share a general architectural design comprising a conserved narrow selectivity filter, which forms intimate interactions with permeant ions, flanked by two wider vestibules toward the internal and external openings. In large-conductance K+ channels, the inner vestibule is wide, whereas in small-conductance channels it is narrow. Here we raise the idea that the physical dimensions of the hydrophobic internal vestibule limit ion transport in K+ channels, accounting for their diversity in unitary conductance. PMID:27619418

  1. Roughness coefficients for stream channels in Arizona

    Science.gov (United States)

    Aldridge, B.N.; Garrett, J.M.

    1973-01-01

    When water flows in an open channel, energy is lost through friction along the banks and bed of the channel and through turbulence within the channel. The amount of energy lost is governed by channel roughness, which is expressed in terms of a roughness coefficient. An evaluation of the roughness coefficient is necessary in many hydraulic computations that involve flow in an open channel. Owing to the lack of satisfactory quantitative procedure, the ability of evaluate roughness coefficients can be developed only through experience; however, a basic knowledge of the methods used to assign the coefficients and the factors affecting them will be a great help. One of the most commonly used equations in open-channel hydraulics is that of Manning. The Manning equation is       1.486

  2. US U-25 channel performance analysis

    Energy Technology Data Exchange (ETDEWEB)

    Doss, E.; Pan, Y. C.

    1980-07-01

    The results of an ANL computational analysis of the performance of the US U-25 MHD channel are presented. This channel has gone through several revisions. The major revision occurred after it had been decided by the DOE Office of MHD to operate the channel with platinum-clad copper electrodes (cold), rather than with ceramic electrodes (hot), as originally planned. This work has been performed at the request of the DOE Office of MHD and the US U-25 generator design Review Committee. The channel specifications and operating conditions are presented. The combustor temperature and thermodynamic and electrical properties of the plasma are computed, and the results are discussed. The MHD channel performance has been predicted for different operating conditions. Sensitivity studies have also been performed on the effects of mass flow rate, surface roughness, combustor temperatures, and loading on the channel performance.

  3. BK channel activators and their therapeutic perspectives

    DEFF Research Database (Denmark)

    Bentzen, Bo Hjorth; Olesen, Søren-Peter; Rønn, Lars C B

    2014-01-01

    The large conductance calcium- and voltage-activated K(+) channel (KCa1.1, BK, MaxiK) is ubiquitously expressed in the body, and holds the ability to integrate changes in intracellular calcium and membrane potential. This makes the BK channel an important negative feedback system linking increases...... in intracellular calcium to outward hyperpolarizing potassium currents. Consequently, the channel has many important physiological roles including regulation of smooth muscle tone, neurotransmitter release and neuronal excitability. Additionally, cardioprotective roles have been revealed in recent years. After...... a short introduction to the structure, function and regulation of BK channels, we review the small organic molecules activating BK channels and how these tool compounds have helped delineate the roles of BK channels in health and disease....

  4. Analytical Prediction Of Meandering Channel Evolution

    Science.gov (United States)

    Chen, D.; Duan, J. G.

    2003-12-01

    The evolution of meandering channels, as a complex phenomenon, has been the research subject challenging river engineers for decades. The evolution of meandering channels is a complex morph-dynamic process resulted from the interaction among flow, sediment, and bank material. The rate of bank erosion was conventionally assumed to be proportional to the magnitude of near-bank excessive velocity or shear stress. A number of laboratory experiments on mild curved channels of flat beds indicated that the high velocity zone crosses the channel centerline at the neighborhood of the downstream inflection point instead of immediately downstream of the apex. If bank erosion only occurs at the places of high shear stress, the erosion of convex banks should be observed in these laboratory flumes, and the bends tend to subside. However, numerous experiments proved that a moderately or highly sinuous channel was initiated from a straight or mildly curved channel of no transverse slope by eroding the concave banks. Obviously

  5. KATP Channels in the Cardiovascular System.

    Science.gov (United States)

    Foster, Monique N; Coetzee, William A

    2016-01-01

    KATP channels are integral to the functions of many cells and tissues. The use of electrophysiological methods has allowed for a detailed characterization of KATP channels in terms of their biophysical properties, nucleotide sensitivities, and modification by pharmacological compounds. However, even though they were first described almost 25 years ago (Noma 1983, Trube and Hescheler 1984), the physiological and pathophysiological roles of these channels, and their regulation by complex biological systems, are only now emerging for many tissues. Even in tissues where their roles have been best defined, there are still many unanswered questions. This review aims to summarize the properties, molecular composition, and pharmacology of KATP channels in various cardiovascular components (atria, specialized conduction system, ventricles, smooth muscle, endothelium, and mitochondria). We will summarize the lessons learned from available genetic mouse models and address the known roles of KATP channels in cardiovascular pathologies and how genetic variation in KATP channel genes contribute to human disease. Copyright © 2016 the American Physiological Society.

  6. Pharmaceutical Distribution Market Channels in Poland

    OpenAIRE

    Agnieszka Woś

    2009-01-01

    Distribution on the pharmaceutical market in Poland is interesting and the most difficult sphere to manage. Numerous varied and specialized companies operating on the market cause that the processes of choosing middlemen in distribution channels are very complex. The hereby article presents the role and location of the companies operating within distribution channels on the pharmaceutical market. It draws attention to the development of non-pharmacy and non-wholesale sales channels.

  7. Monetary Policy and the Redistribution Channel

    OpenAIRE

    Adrien Auclert

    2015-01-01

    This paper evaluates the role of redistribution in the transmission mechanism of monetary policy to consumption. Using consumer theory, I show that redistribution has aggregate effects whenever marginal propensities to consume (MPCs) covary, across households, with balance-sheet exposures to aggregate shocks. Unexpected inflation gives rise to a Fisher channel and real interest rate shocks to an interest rate exposure channel; both channels are likely to contribute to the expansionary effects...

  8. Quantum privacy and Schur product channels

    Science.gov (United States)

    Levick, Jeremy; Kribs, David W.; Pereira, Rajesh

    2017-12-01

    We investigate the quantum privacy properties of an important class of quantum channels, by making use of a connection with Schur product matrix operations and associated correlation matrix structures. For channels implemented by mutually commuting unitaries, which cannot privatise qubits encoded directly into subspaces, we nevertheless identify private algebras and subsystems that can be privatised by the channels. We also obtain further results by combining our analysis with tools from the theory of quasi-orthogonal operator algebras and graph theory.

  9. Stability analysis for downflow in heated channels

    International Nuclear Information System (INIS)

    Sampaio, P.A.B. de.

    1985-01-01

    Stability and flow distribution are analysed for downflow in heated channels. It is shown that at low flow rates instabilities associated with the buoyancy forces may appear. A computer code in FORTRAN language to determine downflow distribution among n heated channels is presented. The model used to calculate downflow distribution and the onset of instability is compared with experiments performed in a test section with two parallel channels. (Author) [pt

  10. Multi-Channel Capacitive Sensor Arrays

    OpenAIRE

    Wang, Bingnan; Long, Jiang; Teo, Koon Hoo

    2016-01-01

    In this paper, multi-channel capacitive sensor arrays based on microstrip band-stop filters are studied. The sensor arrays can be used to detect the proximity of objects at different positions and directions. Each capacitive sensing structure in the array is connected to an inductive element to form resonance at different frequencies. The resonances are designed to be isolated in the frequency spectrum, such that the change in one channel does not affect resonances at other channels. The indu...

  11. Universal communication part II: channels with memory

    OpenAIRE

    Lomnitz, Yuval; Feder, Meir

    2012-01-01

    Consider communication over a channel whose probabilistic model is completely unknown vector-wise and is not assumed to be stationary. Communication over such channels is challenging because knowing the past does not indicate anything about the future. The existence of reliable feedback and common randomness is assumed. In a previous paper it was shown that the Shannon capacity cannot be attained, in general, if the channel is not known. An alternative notion of "capacity" was defined, as the...

  12. [Synopsis about the hypothesis of "information channel" of channel-collateral system].

    Science.gov (United States)

    Chang, Xi-Lang

    2008-10-01

    The author of the present paper founded a theorem about the "incompleteness of single channel structure" (nerve, blood vessel, lymphatic, interspace, aperture, etc.) through quantitative and qualitative analysis about the economic information channel in the human body, which eliminates the probability of single channel structure in the information channel of channel (meridian)-collateral system. After comprehensive analysis on the current researches, the author puts forward a neodoxy, i.e., the body "information channel" structure of the channel-collateral system, mainly follows the distribution regularity of systemic statistics, and is not a single specific entity; various layers of the information channel in the main stems of the channel-collaterals are composed of optimized structure tissues. Hence, the structure of this information channel of channel-collateral system is an overall-optimized, sequential and compatible systemic structure. From this neodoxy, the author brings forward a working principle of channel-collaterals, which is supported theoretically by bio-auxology. The longitudinal distribution of the main stems of meridian-collaterals is considered to result from that in the process of the animal evolution, in the animals moving forward, the microscopic complicated movement of intracorporeal information and energy molecules is related to the forward macroscopic and non-uniform movement of organism in trans-measure. Its impulse and kinetic momentum forms a main vector in the longitudinal direction of the body (the direction of the main stem of channel-collaterals). In order to adapt to and utilize natural regularities, the main stems of the channel-collaterals gradually differentiate and evolve in the living organism, forming a whole system. The "hypothesis of biological origin of channel-collateral system" and "that of information channel of the channel-collaterals in the body" constitute a relatively complete theoretical system framework.

  13. Channel Restoration Design for Meandering Rivers

    National Research Council Canada - National Science Library

    Soar, Philip

    2001-01-01

    A framework for channel restoration design is presented that attempts to bridge the divide between reconnaissance level geomorphological designs at one extreme and numerical modeling of hydrodynamics...

  14. Achromatic Cooling Channel with Li Lenses

    Energy Technology Data Exchange (ETDEWEB)

    Balbekov, V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2002-04-29

    A linear cooling channel with Li lenses, solenoids, and 201 MHz RF cavities is considered. A special lattice design is used to minimize chromatic aberrations by suppression of several betatron resonances. Transverse emittance of muon beam decreases from 2 mm to 0.5 mm at the channel of about 110 m length. Longitudinal heating is modest, therefore transmission of the channel is rather high: 96% without decay and 90% with decay. Minimal beam emittance achievable by similar channel estimated as about 0.25 mm at surface field of Li lenses 10 T.

  15. Flow and sediment transport across oblique channels

    DEFF Research Database (Denmark)

    Hjelmager Jensen, Jacob; Madsen, Erik Østergaard; Fredsøe, Jørgen

    1998-01-01

    A 3D numerical investigation of flow across channels aligned obliquely to the main flow direction has been conducted. The applied numerical model solves the Reynolds-averaged Navier-Stokes equations using the k-ε model for turbulence closure on a curvilinear grid. Three momentum equations...... are solved, but the computational domain is 2D due to a uniformity along the channel alignment. Two important flow features arise when the flow crosses the channel: (i) the flow will be refracted in the direction of the channel alignment. This may be described by a depth-averaged model. (ii) due to shear...

  16. Calcium channel blockers and prostate cancer.

    Science.gov (United States)

    Loughlin, Kevin R

    2014-07-01

    The relationship between calcium channel blockers and prostate cancer has been an area of increased interest to investigators. Calcium channel blockers have been shown to influence cell proliferation, differentiation, and apoptosis. Clinically, the association between calcium channel blockers and the development of prostate cancer has been controversial. However, on a basic science level, there is evidence that calcium channel blockers induce cytotoxicity in androgen receptor positive cell lines and may offer an innovative strategy for the treatment of castration-resistant prostate cancer. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Measuring Balance Across Multiple Radar Receiver Channels.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W.; Bickel, Douglas L.

    2018-03-01

    When radar receivers employ multiple channels, the general intent is for the receive channels to be as alike as possible, if not as ideal as possible. This is usually done via prudent hardware design, supplemented by system calibration. Towards this end, we require a quality metric for ascertaining the goodness of a radar channel, and the degree of match to sibling channels. We propose a relevant and useable metric to do just that. Acknowledgements This report was the result of an unfunded research and development activity.

  18. The Origins of Transmembrane Ion Channels

    Science.gov (United States)

    Pohorille, Andrew; Wilson, Michael A.

    2012-01-01

    Even though membrane proteins that mediate transport of ions and small molecules across cell walls are among the largest and least understood biopolymers in contemporary cells, it is still possible to shed light on their origins and early evolution. The central observation is that transmembrane portions of most ion channels are simply bundles of -helices. By combining results of experimental and computer simulation studies on synthetic models and natural channels, mostly of non-genomic origin, we show that the emergence of -helical channels was protobiologically plausible, and did not require highly specific amino acid sequences. Despite their simple structure, such channels could possess properties that, at the first sight, appear to require markedly larger complexity. Specifically, we explain how the antiamoebin channels, which are made of identical helices, 16 amino acids in length, achieve efficiency comparable to that of highly evolved channels. We further show that antiamoebin channels are extremely flexible, compared to modern, genetically coded channels. On the basis of our results, we propose that channels evolved further towards high structural complexity because they needed to acquire stable rigid structures and mechanisms for precise regulation rather than improve efficiency. In general, even though architectures of membrane proteins are not nearly as diverse as those of water-soluble proteins, they are sufficiently flexible to adapt readily to the functional demands arising during evolution.

  19. Customer Engagement Tool (Multi Channel Communication)

    Data.gov (United States)

    Social Security Administration — Add new infrastructure within SSA's Enterprise Architecture to allow interactions over multiple, yet to be defined, channels. Possibilities include: Provide a portal...

  20. Fuel channel closure and adapter

    International Nuclear Information System (INIS)

    Cashen, W.S.

    1985-01-01

    This invention provides a mechanical closure/actuating ram combination particularly suited for use in sealing the ends of the pressure tubes when a CANDU-type reactor is refueled. It provides a cluster that may be inserted into a fuel channel end fitting to provide at least partial closing off of a pressure tube while permitting the disengagement of the fueling machine and its withdrawal from the closure for other purposes. The invention also provides a ram/closure combination wherein the application of loading force to a deformable sealing disk is regulated by a massive load bar component forming part of the fueling machine and being therefore accessible for maintenance or replacement

  1. Channeling and related crystal effects

    International Nuclear Information System (INIS)

    Uggerhoj, Erik

    1995-01-01

    Channeling, the interaction of particles with oriented crystals, has been applied in a wide variety of scientific and technological areas. A workshop at Aarhus, Denmark, this summer highlighted progress and future directions. Radiation emission has been explored and linked to coherent bremsstrahlung and other oriented crystal radiations. Dramatic effects have been found for ultra-relativistic electrons with Lorentz factors of 105 6. Single crystals are unique for investigations of quantum electrodynamics in strong external fields because probabilities for processes in axial/ planar fields are determined by the magnitude of these fields in the particle rest frame. Erik Uggerhoj of Aarhus reported on an extensive series of experiments concerning radiation emission, pair production, and shower formation carried out at CERN by the NA43 collaboration. As Vladimir Baier of Novosibirsk and Yuri Kononets of Kurchatov noted, theoretical treatment of these interconnected radiation distributions is challenging and much work needs to be done. In general, the agreement with the CERN experiments is good, but many areas like polarization phenomena and particle production need investigation. Prominent among high energy applications is extraction from accelerators. At the workshop, Alexei Asseev reported on beam extraction using a bent crystal at Serpukhov. Konrad Elsener and Jukka Klem reviewed recent CERN SPS studies driven by the possibility of using crystals for extraction of LHC beams. Thornton Murphy of Fermilab announced a step in that direction, with a demonstration this summer of extraction from the Tevatron at 900 GeV. Bent crystal channeling is also used for handling extracted high energy beams. Niels Doble presented a beautiful example of a beam for the CERN NA48 CP-violation experiment. Yuri Chesnokov reported that beams had been deflected through angles up to 150 milliradians at Serpukhov

  2. EPICS channel access using websocket

    International Nuclear Information System (INIS)

    Uchiyama, A.; Furukawa, K.; Higurashi, Y.

    2012-01-01

    Web technology is useful as a means of widely disseminating accelerator and beam status information. For this purpose, WebOPI was implemented by SNS as a web-based system using Ajax (asynchronous JavaScript and XML) with EPICS. On the other hand, it is often necessary to control the accelerator from different locations as well as the central control room during beam operation and maintenance. However, it is not realistic to replace the GUI-based operator interface (OPI) with a Web-based system using Ajax technology because of interactive performance issue. Therefore, as a next generation OPI over the web using EPICS Channel Access (CA), we developed a client system based on WebSocket, which is a new protocol provided by the Internet Engineering Task Force (IETF) for Web-based systems. WebSocket is a web technology that provides bidirectional, full-duplex communication channels over a single TCP connection. By utilizing Node.js and the WebSocket access library called Socket.IO, a WebSocket server was implemented. Node.js is a server-side JavaScript language built on the Google V8 JavaScript Engine. In order to construct the WebSocket server as an EPICS CA client, an add-on for Node.js was developed in C/C++ using the EPICS CA library, which is included in the EPICS base. As a result, for accelerator operation, Web-based client systems became available not only in the central control room but also with various types of equipment. (author)

  3. An information-guided channel-hopping scheme for block-fading channels with estimation errors

    KAUST Repository

    Yang, Yuli

    2010-12-01

    Information-guided channel-hopping technique employing multiple transmit antennas was previously proposed for supporting high data rate transmission over fading channels. This scheme achieves higher data rates than some mature schemes, such as the well-known cyclic transmit antenna selection and space-time block coding, by exploiting the independence character of multiple channels, which effectively results in having an additional information transmitting channel. Moreover, maximum likelihood decoding may be performed by simply decoupling the signals conveyed by the different mapping methods. In this paper, we investigate the achievable spectral efficiency of this scheme in the case of having channel estimation errors, with optimum pilot overhead for minimum meansquare error channel estimation, when transmitting over blockfading channels. Our numerical results further substantiate the robustness of the presented scheme, even with imperfect channel state information. ©2010 IEEE.

  4. Differential Effects of TRPA and TRPV Channels on Behaviors of

    Directory of Open Access Journals (Sweden)

    Jennifer Thies

    2016-01-01

    Full Text Available TRPA and TRPV ion channels are members of the transient receptor potential (TRP cation channel superfamily, which mediates various sensory transductions. In Caenorhabditis elegans , the TRPV channels are known to affect chemosensation, while the TRPA-1 channel is associated with thermosensation and mechanosensation. We examined thermosensation, chemosensation, and osmosensation in strains lacking TRPA-1 or TRPV channels. We found that TRPV channel knockout worms exhibited similar behavioral deficits associated with thermotaxis as the TRPA-1 channel knockout, suggesting a dual role for TRPV channels. In contrast, chemosensation responses, assessed by both avoidance reversal behavior and NaCl osmosensation, were dependent on TRPV channels but seemed independent of TRPA-1 channel. Our findings suggest that, in addition to TRPA-1 channel, TRPV channels are necessary for thermotaxis and may activate, or modulate, the function of TRPA-1 channels. In contrast, TRPA-1 channels do not have a dual responsibility, as they have no functional role in odorant avoidance or osmosensation.

  5. XPM-induced degradation of multilevel phase modulated channel caused by neighboring NRZ modulated channels

    DEFF Research Database (Denmark)

    Jensen, Jesper Bevensee; Schiellerup, G.; Peucheret, Christophe

    2008-01-01

    The impact of XPM from NRZ modulated channels on an 8-level phase modulated channel in a WDM system was investigated. Requirements on launch power are found. 400 km transmission was achieved with negligible penalty.......The impact of XPM from NRZ modulated channels on an 8-level phase modulated channel in a WDM system was investigated. Requirements on launch power are found. 400 km transmission was achieved with negligible penalty....

  6. Innate immune response of channel catfish (Ictalurus punctatus) mannose-binding lectin to channel catfish virus

    Science.gov (United States)

    The channel catfish virus (CCV) is a pathogenic herpesvirus that infects channel catfish (Ictalurus punctatus) in pond aquaculture in the Southeast USA. The innate immune protein mannose-binding lectin (MBL) could play an important role in the innate response of channel catfish by binding to the CC...

  7. Highlights for the 6th International Ion Channel Conference: ion channel structure, function, disease and therapeutics

    Directory of Open Access Journals (Sweden)

    Limei Wang

    2017-11-01

    Full Text Available To foster communication and interactions amongst international scholars and scientists in the field of ion channel research, the 6th International Ion Channel Conference (IICC-2017 was held between June 23–27, 2017 in the eastern coastal city of Qingdao, China. The meeting consisted of 450 attendees and 130 speakers and poster presenters. The program consisted of research progress, new findings and ongoing studies that were focused on (1 Ion channel structure and function; (2 Ion channel physiology and human diseases; (3 Ion channels as targets for drug discovery; (4 Technological advances in ion channel research. An insightful overview was presented on the structure and function of the mechanotransduction channel Drosophila NOMPC (No mechanoreceptor potential C, a member of the transient receptor potential (TRP channel family. Recent studies on Transmembrane protein 16 or Anoctamin-1 (TMEM16A, a member of the calcium-activated chloride channel [CaCC] family were summarized as well. In addition, topics for ion channel regulation, homeostatic feedback and brain disorders were thoroughly discussed. The presentations at the IICC-2017 offer new insights into our understanding of ion channel structures and functions, and ion channels as targets for drug discovery.

  8. Multi-reaction-channel fitting calculations in a coupled-channel ...

    Indian Academy of Sciences (India)

    Gx; 13.75.Jz; 14.20.Gk; 25.80.-e. 1. Introduction. To describe channel coupling effects we adopt the K-matrix formalism. ... Also for some of the strangeness production channels the effect of including the ρ-channel clearly affects the .... The range multiplier for the values is given on top, the name of the parameter below. 220.

  9. Optimising the Quality of Experience during Channel Zapping : The Impact of Advertisements during Channel Zapping

    NARCIS (Netherlands)

    Kooij, R.E.; Klos, V.B.; Godana, B.E.; Nicolai, F.P.; Ahmed, O.K.

    2009-01-01

    Nowadays various digital television services are available. However, the user of these services experiences longer delays than the traditional analog TV while switching from channel to channel. The digital TV operator usually displays a black screen with the channel number during zapping. However,

  10. Theoretical postulation of PLC channel model

    Directory of Open Access Journals (Sweden)

    Alexandru Ionuţ Chiuţă

    2009-05-01

    Full Text Available The objective of this document is to supply atheoretical basis for modelling the communicationlinks over powerlines. A comprehensive summary oftransmission properties and the noise scenario onpublic mains supply when used for data transmissionare given.Different PLC models - PLC channel, noise inPLC channel, coupling units, filters and conditioningdevices – will be created and they will be used tosimulate the PLC channel.PLC applications will have to work at veryunusual channels, solely designed for optimalelectrical power transportation, completelydisregarding signal transmission at high frequencies.It is shown that the typical properties aredescribed by transfer functions and noise scenariostypical for access and inhouse networks. The generaltransfer function for different channel types is derivedand, since an emulation system should reproducetypical classes of channels rather than singlemeasurements, the transfer function is concretisedwith reference channels. These are later serving asbasis for development of channel simulators andchannel emulators. Special attention is paid tomodelling of aperiodic impulsive noise since PLCsystems are reacting very sensitive to them and thisclass of noise has been insufficiently considered so far.

  11. Channel One Online: Advertising Not Educating.

    Science.gov (United States)

    Pasnik, Shelley

    Rather than viewing Channel One's World Wide Web site as an authentic news bureau, as the organization claims, it is better understood as an advertising delivery system. The web site is an attempt to expand Channel One's reach into schools, taking advantage of unsuspecting teachers and students who might fall prey to spurious claims. This paper…

  12. Energy detector performance in Rician fading channel

    Directory of Open Access Journals (Sweden)

    Brkić Srđan S.

    2013-01-01

    Full Text Available In this paper we analyzed the problem of detection of unknown signals in the Rician fading channel. A closed-form expression for the probability of detection is derived, followed by the numerical results. The analysis was extended to the case of cooperative sensor network in which the environment can be modelled by independent Rician fading channels.

  13. The sedimentary record of submarine channel morphodynamics

    NARCIS (Netherlands)

    de Leeuw, J.

    2017-01-01

    Submarine channels are ubiquitous on the ocean floor and are considered to be the equivalent of rivers on land. These channels are created by turbidity currents, which originate from the continental margins and which can transport sediment for thousands of kilometres into the oceans. The aim of this

  14. Polyps in continent catheterizable bladder channels.

    Science.gov (United States)

    Groth, Travis W; Mitchell, Michael E; Balcom, Anthony H

    2013-02-01

    We describe our experience with polyps encountered in bladder continent catheterizable channels. An IRB-approved retrospective study was conducted on all patients at Children's Hospital of Wisconsin with continent catheterizable channels managed by a single physician over a 16-year time period. Fifty-five patients were identified with bladder channels. During a median follow-up of 7 years (range 3-16 years), 20% (11/55) of bladder channels developed polyps. The time to diagnosis of a polyp in bladder channels from initial surgery ranged from 3 months to 8 years (median of 29 months). Fifty-five percent (6/11) of patients who developed bladder polyps were symptomatic. All patients' symptoms resolved after treatment by endoscopic resection. Forty-five percent (5/11) of polyps recurred after resection. The time of recurrence ranged from 4 months to 7 years (median of 19 months). Polyps were universally benign inflammatory granulomatous tissue. This is the first series reporting the incidence of polyps in bladder catheterizable channels. Patients with continent catheterizable bladder channels can develop symptomatic polyps in their channels, of unknown long-term significance and risk. Copyright © 2011 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  15. Measuring vibrations in fuel channels CNE

    International Nuclear Information System (INIS)

    Martín Ghiselli, A.; Fiori, J.; Sacchi, M.; Villabrille, G.

    2013-01-01

    This paper present a description of implementation and execution of vibration measurements made at the request of NUCLEOELECTRICA ARGENTINA S.A. on the ends of the reactor fuel channels of Embalse Nuclear Power Plant to explore possible differences between the dynamic behavior of empty fuel channel and with full charge of fuel elements inside. (author)

  16. Hydrodynamic blood plasma separation in microfluidic channels

    DEFF Research Database (Denmark)

    Jouvet, Lionel

    2010-01-01

    The separation of red blood cells from plasma flowing in microchannels is possible by biophysical effects such as the Zweifach–Fung bifurcation law. In the present study, daughter channels are placed alongside a main channel such that cells and plasma are collected separately. The device is aimed...

  17. Steady turbulent flow in curved rectangular channels

    NARCIS (Netherlands)

    De Vriend, H.J.

    1979-01-01

    After the study of fully developed and developing steady laminar flow in curved channels of shallow rectangular wet cross-section (see earlier reports in this series), steady turbulent flow in such channels is investigated as a next step towards a mathematical model of the flow in shallow river

  18. Developing laminar flow in curved rectangular channels

    NARCIS (Netherlands)

    De Vriend, H.J.

    1978-01-01

    As an intermediate step between earlier investigations on fully developed laminar flow in curved channels of shallow rectancular wet cross-section and the mathematical modeling of turbulent flow in river bends, a mathematical model of developing laminar flow in such channels is investigated. The

  19. On the dynamics of the Zanzibar Channel

    Science.gov (United States)

    Zavala-Garay, J.; Theiss, J.; Moulton, M.; Walsh, C.; van Woesik, R.; Mayorga-Adame, C. G.; García-Reyes, M.; Mukaka, D. S.; Whilden, K.; Shaghude, Y. W.

    2015-09-01

    The Zanzibar Channel lies between the mainland of Tanzania and Zanzibar Island in the tropical western Indian Ocean, is about 100 km long, 40 km wide, and 40 m deep, and is essential to local socioeconomic activities. This paper presents a model of the seasonal and tidal dynamics of the Zanzibar Channel based on the Regional Ocean Modeling System (ROMS) and a comparison of the model and observations. The seasonal dynamics of the channel is forced by remote processes and the local wind. Remote forcing creates the East African Coastal Current, a portion of which flows through the channel northward with a seasonally varying magnitude. The local wind enhances this seasonality in the surface Ekman layer, resulting in a stronger northward flow during the southwest monsoon season and a weak northward or occasionally southward flow during the northeast monsoon season. The tidal flows converge and diverge in the center of the channel and reduce the transport in the channel. The remotely forced, wind-forced, and tidal dynamics contain 5%, 3%, and 92% of the total kinetic energy, respectively. Despite their low kinetic energy, the remotely forced and wind-forced flows are most relevant in advecting channel water to the open ocean, which occurs in 19 days at the peak of the southwest monsoon season. The channel is well mixed, except during brief periods in the two rainy seasons, and temporarily cools between December and February. The dispersion of passive tracers is presented as an example of potential model applications.

  20. Forbidden Channels and SIMP Dark Matter

    OpenAIRE

    Choi Soo-Min; Kang Yoo-Jin; Lee Hyun Min

    2018-01-01

    In this review, we focus on dark matter production from thermal freeze-out with forbidden channels and SIMP processes. We show that forbidden channels can be dominant to produce dark matter depending on the dark photon and / or dark Higgs mass compared to SIMP.

  1. Laboratory Experiments on Meandering Meltwater Channels

    Science.gov (United States)

    Fernandez, R.; Berens, J.; Parker, G.; Stark, C. P.

    2017-12-01

    Meandering channels of all scales and flowing over a wide variety of media have common planform patterns. Although the analogy in planform suggests there is a common underlying framework, the constitutive relations driving planform evolution through vertical incision/deposition and lateral migration differ from medium to medium. The driving processes in alluvial and mixed bedrock-alluvial meandering channels have been studied substantially over the last decades. However, this is not the case for meandering channels in other media such as ice or soluble rock. Here we present results from experiments conducted at the Ven Te Chow Hydrosystems Laboratory of the University of Illinois at Urbana-Champaign on meltwater meandering channels. A rivulet is carved into an ice block and water is allowed to flow at a constant discharge. Planform evolution is analyzed with time lapse imaging and complemented with rubber molds of the channel once the experiment is over. These molds give us the full 3D structure of the meandering, including incisional overhang. Vertical incision rates are measured throughout the run by taking elevations along the channel, and these measurements are complemented with analysis from the molds. We show examples of meandering of intense amplitude with deep overhangs. Features resembling scroll bars document cyclically punctuated melting. We report on lateral migration rates, incision rates, sinuosity, channel depths, channel widths, reach averaged velocities, bend wavelengths and amplitudes and compare them to values reported in the literature for alluvial rivers.

  2. Adaptive RAC codes employing statistical channel evaluation ...

    African Journals Online (AJOL)

    An adaptive encoding technique using row and column array (RAC) codes employing a different number of parity columns that depends on the channel state is proposed in this paper. The trellises of the proposed adaptive codes and a statistical channel evaluation technique employing these trellises are designed and ...

  3. Mixed convection in a baffled grooved channel

    Indian Academy of Sciences (India)

    In the present numerical work, flow structure and heat transfer characteristics are investigated in a baffled grooved channel, differentially heated from the sides. The baffle is placed vertically downward from the top wall of grooved channel geometry, with the motive of diverting outside forced flow towards the inside of the ...

  4. Pharmacological modulation of SK3 channels

    DEFF Research Database (Denmark)

    Grunnet, M; Jespersen, Thomas; Angelo, K

    2001-01-01

    -frequency adaptation, pharmacological modulation of SK channels may be of significant clinical importance. Here we report the functional expression of SK3 in HEK293 and demonstrate a broad pharmacological profile for these channels. Brain slice studies commonly employ 4-aminopyridine (4-AP) to block voltage...

  5. Ion channel model development and validation

    Science.gov (United States)

    Nelson, Peter Hugo

    2010-03-01

    The structure of the KcsA ion channel selectivity filter is used to develop three simple models of ion channel permeation. The quantitative predictions of the knock-on model are tested by comparison with experimental data from single-channel recordings of the KcsA channel. By comparison with experiment, students discover that the knock-on model can't explain saturation of ion channel current as the concentrations of the bathing solutions are increased. By inverting the energy diagram, students derive the association-dissociation model of ion channel permeation. This model predicts non-linear Michaelis-Menten saturating behavior that requires students to perform non-linear least-squares fits to the experimental data. This is done using Excel's solver feature. Students discover that this simple model does an excellent job of explaining the qualitative features of ion channel permeation but cannot account for changes in voltage sensitivity. The model is then extended to include an electrical dissociation distance. This rapid translocation model is then compared with experimental data from a wide variety of ion channels and students discover that this model also has its limitations. Support from NSF DUE 0836833 is gratefully acknowledged.

  6. Hydraulics of free overfall in -shaped channels

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    MS received 15 October 2001; revised 13 February 2002. Abstract. In this paper, two methods are presented to analyse the free overfall in. -shaped (equilateral triangle-shaped) channels. First, the flow upstream of a free overfall from smooth horizontal or mildly sloping -shaped channels is analysed theoretically to ...

  7. Channel selection for automatic seizure detection

    DEFF Research Database (Denmark)

    Duun-Henriksen, Jonas; Kjaer, Troels Wesenberg; Madsen, Rasmus Elsborg

    2012-01-01

    Objective: To investigate the performance of epileptic seizure detection using only a few of the recorded EEG channels and the ability of software to select these channels compared with a neurophysiologist. Methods: Fifty-nine seizures and 1419 h of interictal EEG are used for training and testing...

  8. Functional architecture of the CFTR chloride channel.

    Science.gov (United States)

    Linsdell, Paul

    2014-02-01

    Cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), a member of the ATP-binding cassette (ABC) family of membrane transport proteins. CFTR is unique among ABC proteins in that it functions not as an active transporter but as an ATP-gated Cl(-) channel. As an ion channel, the function of the CFTR transmembrane channel pore that mediates Cl(-) movement has been studied in great detail. On the other hand, only low resolution structural data is available on the transmembrane parts of the protein. The structure of the channel pore has, however, been modeled on the known structure of active transporter ABC proteins. Currently, significant barriers exist to building a unified view of CFTR pore structure and function. Reconciling functional data on the channel with indirect structural data based on other proteins with very different transport functions and substrates has proven problematic. This review summarizes current structural and functional models of the CFTR Cl(-) channel pore, including a comprehensive review of previous electrophysiological investigations of channel structure and function. In addition, functional data on the three-dimensional arrangement of pore-lining helices, as well as contemporary hypotheses concerning conformational changes in the pore that occur during channel opening and closing, are discussed. Important similarities and differences between different models of the pore highlight current gaps in our knowledge of CFTR structure and function. In order to fill these gaps, structural and functional models of the membrane-spanning pore need to become better integrated.

  9. REVIEW OF WIRELESS MIMO CHANNEL MODELS | Anioke ...

    African Journals Online (AJOL)

    The need to increase spectral efficiency has led to the design of multiple antenna systems for both transmit and receive sides otherwise known as MIMO. Channel modeling forms an integral part of this design. Therefore it is very important to investigate and understand existing MIMO channel models. This paper provides a ...

  10. Voltage-gated lipid ion channels

    DEFF Research Database (Denmark)

    Blicher, Andreas; Heimburg, Thomas Rainer

    2013-01-01

    probability as a function of voltage. The voltage-dependence of the lipid pores is found comparable to that of protein channels. Lifetime distributions of open and closed events indicate that the channel open distribution does not follow exponential statistics but rather power law behavior for long open times...

  11. REVIEW OF WIRELESS MIMO CHANNEL MODELS

    African Journals Online (AJOL)

    user

    The need to increase spectral efficiency has led to the design of multiple antenna systems for both transmit and receive sides otherwise known as MIMO. Channel modeling forms an integral part of this design. Therefore it is very important to investigate and understand existing MIMO channel models. This paper provides a ...

  12. Privacy of a lossy bosonic memory channel

    International Nuclear Information System (INIS)

    Ruggeri, Giovanna; Mancini, Stefano

    2007-01-01

    We study the security of the information transmission between two honest parties realized through a lossy bosonic memory channel when losses are captured by a dishonest party. We then show that entangled inputs can enhance the private information of such a channel, which however does never overcome that of unentangled inputs in absence of memory

  13. Radio Channel Modeling in Body Area Networks

    NARCIS (Netherlands)

    An, L.; Bentum, Marinus Jan; Meijerink, Arjan; Scanlon, W.G.

    2009-01-01

    A body area network (BAN) is a network of bodyworn or implanted electronic devices, including wireless sensors which can monitor body parameters or to de- tect movements. One of the big challenges in BANs is the propagation channel modeling. Channel models can be used to understand wave propagation

  14. Radio channel modeling in body area networks

    NARCIS (Netherlands)

    An, L.; Bentum, Marinus Jan; Meijerink, Arjan; Scanlon, W.G.

    2010-01-01

    A body area network (BAN) is a network of bodyworn or implanted electronic devices, including wireless sensors which can monitor body parameters or to detect movements. One of the big challenges in BANs is the propagation channel modeling. Channel models can be used to understand wave propagation in

  15. Micromachining of buried micro channels in silicon

    NARCIS (Netherlands)

    de Boer, Meint J.; Tjerkstra, R.W.; Berenschot, Johan W.; Jansen, Henricus V.; Burger, G.J.; Burger, G.J.; Gardeniers, Johannes G.E.; Elwenspoek, Michael Curt; van den Berg, Albert

    A new method for the fabrication of micro structures for fluidic applications, such as channels, cavities, and connector holes in the bulk of silicon wafers, called buried channel technology (BCT), is presented in this paper. The micro structures are constructed by trench etching, coating of the

  16. Channel agnostic healthcare for resource constrained environments

    CSIR Research Space (South Africa)

    Alberts, Ronell

    2015-01-01

    Full Text Available . In order to reach as many end users as possible through the devices that they already own and are comfortable with, channel agnostic access is needed that would support the different mobile access channels using a variety of communications protocols...

  17. Atlantic water flow through the Faroese Channels

    Directory of Open Access Journals (Sweden)

    B. Hansen

    2017-11-01

    Full Text Available Through the Faroese Channels – the collective name for a system of channels linking the Faroe–Shetland Channel, Wyville Thomson Basin, and Faroe Bank Channel – there is a deep flow of cold waters from Arctic regions that exit the system as overflow through the Faroe Bank Channel and across the Wyville Thomson Ridge. The upper layers, in contrast, are dominated by warm, saline water masses from the southwest, termed Atlantic water. In spite of intensive research over more than a century, there are still open questions on the passage of these waters through the system with conflicting views in recent literature. Of special note is the suggestion that there is a flow of Atlantic water from the Faroe–Shetland Channel through the Faroe Bank Channel, which circles the Faroes over the slope region in a clockwise direction. Here, we combine the observational evidence from ship-borne hydrography, moored current measurements, surface drifter tracks, and satellite altimetry to address these questions and propose a general scheme for the Atlantic water flow through this channel system. We find no evidence for a continuous flow of Atlantic water from the Faroe–Shetland Channel to the Faroe Bank Channel over the Faroese slope. Rather, the southwestward-flowing water over the Faroese slope of the Faroe–Shetland Channel is totally recirculated within the combined area of the Faroe–Shetland Channel and Wyville Thomson Basin, except possibly for a small release in the form of eddies. This does not exclude a possible westward flow over the southern tip of the Faroe Shelf, but even including that, we estimate that the average volume transport of a Circum-Faroe Current does not exceed 0.5 Sv (1 Sv  =  106 m3 s−1. Also, there seems to be a persistent flow of Atlantic water from the western part of the Faroe Bank Channel into the Faroe–Shetland Channel that joins the Slope Current over the Scottish slope. These conclusions will affect

  18. Atlantic water flow through the Faroese Channels

    Science.gov (United States)

    Hansen, Bogi; Poulsen, Turið; Margretha Húsgarð Larsen, Karin; Hátún, Hjálmar; Østerhus, Svein; Darelius, Elin; Berx, Barbara; Quadfasel, Detlef; Jochumsen, Kerstin

    2017-11-01

    Through the Faroese Channels - the collective name for a system of channels linking the Faroe-Shetland Channel, Wyville Thomson Basin, and Faroe Bank Channel - there is a deep flow of cold waters from Arctic regions that exit the system as overflow through the Faroe Bank Channel and across the Wyville Thomson Ridge. The upper layers, in contrast, are dominated by warm, saline water masses from the southwest, termed Atlantic water. In spite of intensive research over more than a century, there are still open questions on the passage of these waters through the system with conflicting views in recent literature. Of special note is the suggestion that there is a flow of Atlantic water from the Faroe-Shetland Channel through the Faroe Bank Channel, which circles the Faroes over the slope region in a clockwise direction. Here, we combine the observational evidence from ship-borne hydrography, moored current measurements, surface drifter tracks, and satellite altimetry to address these questions and propose a general scheme for the Atlantic water flow through this channel system. We find no evidence for a continuous flow of Atlantic water from the Faroe-Shetland Channel to the Faroe Bank Channel over the Faroese slope. Rather, the southwestward-flowing water over the Faroese slope of the Faroe-Shetland Channel is totally recirculated within the combined area of the Faroe-Shetland Channel and Wyville Thomson Basin, except possibly for a small release in the form of eddies. This does not exclude a possible westward flow over the southern tip of the Faroe Shelf, but even including that, we estimate that the average volume transport of a Circum-Faroe Current does not exceed 0.5 Sv (1 Sv = 106 m3 s-1). Also, there seems to be a persistent flow of Atlantic water from the western part of the Faroe Bank Channel into the Faroe-Shetland Channel that joins the Slope Current over the Scottish slope. These conclusions will affect potential impacts from offshore activities in the

  19. Complex Simulation Model of Mobile Fading Channel

    Directory of Open Access Journals (Sweden)

    Tomas Marek

    2005-01-01

    Full Text Available In the mobile communication environment the mobile channel is the main limiting obstacle to reach the best performance of wireless system. Modeling of the radio channel consists of two basic fading mechanisms - Long-term fading and Short-term fading. The contribution deals with simulation of complex mobile radio channel, which is the channel with all fading components. Simulation model is based on Clarke-Gans theoretical model for fading channel and is developed in MATLAB environment. Simulation results have shown very good coincidence with theory. This model was developed for hybrid adaptation 3G uplink simulator (described in this issue during the research project VEGA - 1/0140/03.

  20. Indoor MIMO Channel Measurement and Modeling

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ødum; Andersen, Jørgen Bach

    2005-01-01

    Forming accurate models of the multiple input multiple output (MIMO) channel is essential both for simulation as well as understanding of the basic properties of the channel. This paper investigates different known models using measurements obtained with a 16x32 MIMO channel sounder for the 5.8GHz...... band. The measurements were carried out in various indoor scenarios including both temporal and spatial aspects of channel changes. The models considered include the so-called Kronecker model, a model proposed by Weichselberger et. al., and a model involving the full covariance matrix, the most...... accurate model for Gaussian channels. For each of the environments different sizes of both the transmitter and receiver antenna arrays are investigated, 2x2 up to 16x32. Generally it was found that in terms of capacity cumulative distribution functions (CDFs) all models fit well for small array sizes...

  1. Customers’ Perception regarding Assurance of Bancassurance Channel

    Directory of Open Access Journals (Sweden)

    Choudhury Mousumi

    2016-12-01

    Full Text Available Bancassurance has evolved as a strong distribution channel in India. Bancassurance means that the insurance company and the bank come together to offer insurance products from the counter of the banks to the bank’s customer. The present study attempts to analyse customers’ perception regarding assurance of bancassurance channel in providing insurance-related services. The study also tries to find out the impact of various demographic variables on customers’ perception regarding assurance of bancassurance channel. The study finds that customers consider bancassurance channel having high assurance in providing insurance services. It is also found in the study that there is no significant association between the demographic variables considered in the study and customers’ perception regarding assurance of bancassurance channel.

  2. An intracellular anion channel critical for pigmentation.

    Science.gov (United States)

    Bellono, Nicholas W; Escobar, Iliana E; Lefkovith, Ariel J; Marks, Michael S; Oancea, Elena

    2014-12-16

    Intracellular ion channels are essential regulators of organellar and cellular function, yet the molecular identity and physiological role of many of these channels remains elusive. In particular, no ion channel has been characterized in melanosomes, organelles that produce and store the major mammalian pigment melanin. Defects in melanosome function cause albinism, characterized by vision and pigmentation deficits, impaired retinal development, and increased susceptibility to skin and eye cancers. The most common form of albinism is caused by mutations in oculocutaneous albinism II (OCA2), a melanosome-specific transmembrane protein with unknown function. Here we used direct patch-clamp of skin and eye melanosomes to identify a novel chloride-selective anion conductance mediated by OCA2 and required for melanin production. Expression of OCA2 increases organelle pH, suggesting that the chloride channel might regulate melanin synthesis by modulating melanosome pH. Thus, a melanosomal anion channel that requires OCA2 is essential for skin and eye pigmentation.

  3. A computer program for analyzing channel geometry

    Science.gov (United States)

    Regan, R.S.; Schaffranek, R.W.

    1985-01-01

    The Channel Geometry Analysis Program (CGAP) provides the capability to process, analyze, and format cross-sectional data for input to flow/transport simulation models or other computational programs. CGAP allows for a variety of cross-sectional data input formats through use of variable format specification. The program accepts data from various computer media and provides for modification of machine-stored parameter values. CGAP has been devised to provide a rapid and efficient means of computing and analyzing the physical properties of an open-channel reach defined by a sequence of cross sections. CGAP 's 16 options provide a wide range of methods by which to analyze and depict a channel reach and its individual cross-sectional properties. The primary function of the program is to compute the area, width, wetted perimeter, and hydraulic radius of cross sections at successive increments of water surface elevation (stage) from data that consist of coordinate pairs of cross-channel distances and land surface or channel bottom elevations. Longitudinal rates-of-change of cross-sectional properties are also computed, as are the mean properties of a channel reach. Output products include tabular lists of cross-sectional area, channel width, wetted perimeter, hydraulic radius, average depth, and cross-sectional symmetry computed as functions of stage; plots of cross sections; plots of cross-sectional area and (or) channel width as functions of stage; tabular lists of cross-sectional area and channel width computed as functions of stage for subdivisions of a cross section; plots of cross sections in isometric projection; and plots of cross-sectional area at a fixed stage as a function of longitudinal distance along an open-channel reach. A Command Procedure Language program and Job Control Language procedure exist to facilitate program execution on the U.S. Geological Survey Prime and Amdahl computer systems respectively. (Lantz-PTT)

  4. The Zambezi Channel: A new perspective on submarine channel evolution at low latitudes

    Science.gov (United States)

    Wiles, E.; Green, A.; Watkeys, M.; Jokat, W.

    2017-06-01

    Submarine channels are not stand-alone systems. They are long-lived systems modified by imperceptibly slow processes and rapid gravity flows, in some part controlled by hinterland dynamics. The submarine Zambezi Channel, within the Mozambique Channel, receives sediment from the Zambezi River catchment which has a dynamic tectonic and morphological history. Using recently collected multibeam bathymetry and PARASOUND data we discuss the geomorphology of the Zambezi Channel. Results show this system to be distinct in geomorphologic character when compared to other low-latitude submarine channels, sharing similarities with high-latitude systems. We propose a new, source-to-sink, hypothesis for the evolution of the Zambezi Channel, taking in to consideration hinterland tectonics, palaeo-lake development, river capture and rapid gravity flows. This hypothesis accounts for the unique present-day anatomy of the Zambezi Channel within the dynamic framework of the systems regional setting.

  5. Dynamic Digital Channelizer Based on Spectrum Sensing.

    Science.gov (United States)

    Hu, Junpeng; Zuo, Zhen; Huang, Zhiping; Dong, Zhi

    2015-01-01

    The ability to efficiently channelize a received signal with dynamic sub-channel bandwidths is a key requirement of software defined radio (SDR) systems. The digital channelizer, which is used to split the received signal into a number of sub-channels, plays an important role in SDR systems. In this paper, a design of dynamic digital channelizer is presented. The proposed method is novel in that it employs a cosine modulated filter bank (CMFB) to divide the received signal into multiple frequency sub-bands and a spectrum sensing technique, which is mostly used in cognitive radio, is introduced to detect the presence of signal of each sub-band. The method of spectrum sensing is carried out based on the eigenvalues of covariance matrix of received signal. The ratio of maximum-minimum eigenvalue of each sub-band is vulnerable to noise fluctuation. This paper suggests an optimized method to calculate the ratio of maximum-minimum eigenvalue. The simulation results imply that the design of digital channelizer can effectively separate the received signal with dynamically changeable sub-channel signals.

  6. Renoprotective effect of calcium channel blockers

    Directory of Open Access Journals (Sweden)

    Dimković Nada

    2009-01-01

    Full Text Available The advancing chronic renal failure is at most the consequence of secondary haemodynamic and metabolic factors as intraglomerular hypertension and glomerular hypertrophy. Although tight blood pressure control is the major preventive mechanism for progressive renal failure, ACE inhibitors and angiotensin receptor blockers have some other renoprotective mechanisms beyond the blood pressure control. That is why these two groups of antihypertensive drugs traditionally have advantages in treating renal patients especially those with proteinuria over 400-1000 mg/day. Even if earlier experimental studies have shown renoprotective effect of calcium channel blockers, later clinical studies did not prove that calcium channel blockers have any advantages in renal protection over ACE inhibitors given as monotherapy or in combination with ACE inhibitors. It was explained by action of calcium channel blockers on afferent but not on efferent glomerular arterioles; a well known mechanism that leads to intraglomerular hypertension. New generations of dihydropiridine calcium channel blockers can dilate even efferent arterioles not causing unfavorable haemodynamic disturbances. This finding was confirmed in clinical studies which showed that renoprotection established by calcium channel blockers was not inferior to that of ACE inhibitors and that calcium channel blockers and ACE inhibitors have additive effect on renoprotection. Newer generation of dihydropiridine calcium channel blockers seem to offer more therapeutic possibilities in renoprotection by their dual action on afferent and efferent glomerular arterioles and, possibly by other effects beyond the blood pressure control.

  7. Electronic trade effect of marketing channels

    Directory of Open Access Journals (Sweden)

    Lovreta Stipe

    2009-01-01

    Full Text Available E-commerce has caused many significant changes in marketing channels. Consumers had obtained multiple benefits from e-commerce. In addition, it has increased the level of competition in marketing channels. However, the focus of this paper is multichannel strategy and integration of physical (store and electronic marketing channels. E-commerce has induced dynamic development of multichannel strategy. This strategy has evolved as a consequence of multichannel consumer orientation. In developed economies, consumers are multichannel entities and active marketers aim to meet their requirements by creating multichannel offer.

  8. Two-Channel Dielectric Wake Field Accelerator

    International Nuclear Information System (INIS)

    Hirshfield, Jay L.

    2012-01-01

    Experimental results are reported for test beam acceleration and deflection in a two-channel, cm-scale, rectangular dielectric-lined wakefield accelerator structure energized by a 14-MeV drive beam. The dominant waveguide mode of the structure is at ∼30 GHz, and the structure is configured to exhibit a high transformer ratio (∼12:1). Accelerated bunches in the narrow secondary channel of the structure are continuously energized via Cherenkov radiation that is emitted by a drive bunch moving in the wider primary channel. Observed energy gains and losses, transverse deflections, and changes in the test bunch charge distribution compare favorably with predictions of theory.

  9. Numerical simulation of separated flows in channels

    Science.gov (United States)

    Louda, Petr; Příhoda, Jaromír; Sváček, Petr; Kozel, Karel

    2012-04-01

    The work deals with numerical modelling of turbulent flows in channels with an expansion of the cross-section where flow separation and reattachment occur. The performance of several eddy viscosity models and an explicit algebraic Reynolds stress model (EARSM) is studied. The used test cases are flows in channels with various backward facing steps where the step is perpendicular or inclined and the top wall is parallel or deflected. Furthermore, a channel with the circular ramp is considered. The numerical solution is achieved by the finite volume method or by the finite element method. The results of both numerical approaches are compared.

  10. Estimation and Direct Equalization of Doubly Selective Channels

    NARCIS (Netherlands)

    Barhumi, I.; Leus, G.; Moonen, M.

    2006-01-01

    We propose channel estimation and direct equalization techniques for transmission over doubly selective channels. The doubly selective channel is approximated using the basis expansion model (BEM). Linear and decision feedback equalizers implemented by time-varying finite impulse response (FIR)

  11. SK2 channel expression and function in cerebellar Purkinje cells

    NARCIS (Netherlands)

    Hosy, Eric; Piochon, Claire; Teuling, Eva; Rinaldo, Lorenzo; Hansel, Christian

    2011-01-01

    Small-conductance calcium-activated K(+) channels (SK channels) regulate the excitability of neurons and their responsiveness to synaptic input patterns. SK channels contribute to the afterhyperpolarization (AHP) following action potential bursts, and curtail excitatory postsynaptic potentials

  12. Channel Measurements and Characteristics for Cooperative Positioning Applications

    DEFF Research Database (Denmark)

    Wang, Wei; Steinböck, Gerhard; Jost, Thomas

    2012-01-01

    We have conducted an indoor channel measurement campaign to characterize the propagation channel for the development of cooperative positioning algorithms. The campaign focused particularly on the characteristics of multi-link channels with applications to positioning. In this contribution we...

  13. Multi-channel software defined radio experimental evaluation and analysis

    CSIR Research Space (South Africa)

    Van der Merwe, JR

    2014-09-01

    Full Text Available Multi-channel software-defined radios (SDRs) can be utilised as inexpensive prototyping platforms for transceiver arrays. The application for multi-channel prototyping is discussed and measured results of coherent channels for both receiver...

  14. Channel Planform Dynamics Monitoring and Channel Stability Assessment in Two Sediment-Rich Rivers in Taiwan

    Directory of Open Access Journals (Sweden)

    Cheng-Wei Kuo

    2017-01-01

    Full Text Available Recurrent flood events induced by typhoons are powerful agents to modify channel morphology in Taiwan’s rivers. Frequent channel migrations reflect highly sensitive valley floors and increase the risk to infrastructure and residents along rivers. Therefore, monitoring channel planforms is essential for analyzing channel stability as well as improving river management. This study analyzed annual channel changes along two sediment-rich rivers, the Zhuoshui River and the Gaoping River, from 2008 to 2015 based on satellite images of FORMOSAT-2. Channel areas were digitized from mid-catchment to river mouth (~90 km. Channel stability for reaches was assessed through analyzing the changes of river indices including braid index, active channel width, and channel activity. In general, the valley width plays a key role in braided degree, active channel width, and channel activity. These indices increase as the valley width expands whereas the braid index decreases slightly close to the river mouth due to the change of river types. This downstream pattern in the Zhuoshui River was interrupted by hydraulic construction which resulted in limited changes downstream from the weir, due to the lack of water and sediment supply. A 200-year flood, Typhoon Morakot in 2009, induced significant changes in the two rivers. The highly active landscape in Taiwan results in very sensitive channels compared to other regions. An integrated Sensitivity Index was proposed for identifying unstable reaches, which could be a useful reference for river authorities when making priorities in river regulation strategy. This study shows that satellite image monitoring coupled with river indices analysis could be an effective tool to evaluate spatial and temporal changes in channel stability in highly dynamic river systems.

  15. Developing and verifying design and operational criteria for the active sludge process involving staggered feed with the elimination of nitrogen; Desarrollo y verificacion de criterios de diseno y oporacion para el proceso de fangos activos de alimentacion escalonada con eliminacion de nitrogeno

    Energy Technology Data Exchange (ETDEWEB)

    Larrea, L.; Larrea, A.; Ayesa, E.; Rodrigo, J. C.

    2000-07-01

    This study focused on the staggered feed process with three denitrification-nitrification reactor phases. In the first place, criteria for the optimum selection of design parameters were developed using simulations based on mathematical models of the process and efficient operational strategies were suggested. The results of the simulation were then verified by means of tests in a pilot plant. In regard to the design parameters, the simulation studies showed that the optimum in-flow to the three anoxic reactors lies within the range 40-40-20% to 33-33-34%, depending on the characteristics of the waste water and the requirements of the effluent. These latter two conditions and, therefore, the distribution of the inflow, determine the volumes of the aerobic and anoxic reactors. The operating strategy proposed consists in reducing the concentration of dissolved oxygen in the first two aerobic reactors and using optional areas in the last D-N stage of the process. The experimental results obtained confirmed the validity of the design and operational criteria that had been developed. Finally, it was found that if IWA model no. 1 is appropriately calibrated, it has a great capacity for predicting the behaviour of the staggered feed process. (Author) 12 refs.

  16. Dual-recycling channel management for WEEE with stochastic demand

    OpenAIRE

    Li, Chuanfa; Feng, Lipan; Wang, Xuehong

    2014-01-01

    More and more enterprises collecting e-wastes through the online recycling channel as the rapidly improving of the customer acceptance of the online recycling channel. And they are facing a problem, however, that they have to offer a higher price in the online recycling channel than the traditional recycling channel as well as reducing the searching cost by using the online recycling channel. Base on that, we incorporate a detailed consumer recycling channel choice model where the collection ...

  17. Superconducting muon channel at J-PARC

    International Nuclear Information System (INIS)

    Shimomura, K.; Koda, A.; Strasser, P.; Kawamura, N.; Fujimori, H.; Makimura, S.; Higemoto, W.; Nakahara, K.; Ishida, K.; Nishiyama, K.; Nagamine, K.; Miyake, Y.

    2009-01-01

    The Muon Science Laboratory at the Materials and Life Science Facility is now under construction in Japan Proton Accelerator Research Complex (J-PARC), where four types of muon channels are planned to be installed. A conventional superconducting muon channel will be installed at the first stage, which can extract surface (positive) muons and decay positive/negative muons up to 120 MeV/c, and the expected muon yield is a few 10 6 /s at 60 MeV/c (for both positive and negative). This channel will be used for various kinds of experiments like muon catalyzed fusion, μSR and nondestructive elements analysis. The present status of the superconducting muon channel is briefly reported.

  18. Subspace Analysis of Indoor UWB Channels

    Directory of Open Access Journals (Sweden)

    Rachid Saadane

    2005-03-01

    Full Text Available This work aims at characterizing the second-order statistics of indoor ultra-wideband (UWB channels using channel sounding techniques. We present measurement results for different scenarios conducted in a laboratory setting at Institut Eurécom. These are based on an eigendecomposition of the channel autocovariance matrix, which allows for the analysis of the growth in the number of significant degrees of freedom of the channel process as a function of the signaling bandwidth as well as the statistical correlation between different propagation paths. We show empirical eigenvalue distributions as a function of the signal bandwidth for both line-of-sight and non-line-of-sight situations. Furthermore, we give examples where paths from different propagation clusters (possibly arising from reflection or diffraction show strong statistical dependence.

  19. ENHANCING HSPF MODEL CHANNEL HYDRAULIC REPRESENTATION

    Science.gov (United States)

    The Hydrological Simulation Program - FORTRAN (HSPF) is a comprehensive watershed model, which employs depth-area-volume-flow relationships known as hydraulic function table (FTABLE) to represent stream channel cross-sections and reservoirs. An accurate FTABLE determination for a...

  20. Quantum channel construction with circuit quantum electrodynamics

    Science.gov (United States)

    Shen, Chao; Noh, Kyungjoo; Albert, Victor V.; Krastanov, Stefan; Devoret, M. H.; Schoelkopf, R. J.; Girvin, S. M.; Jiang, Liang

    2017-04-01

    Quantum channels can describe all transformations allowed by quantum mechanics. We adapt two existing works [S. Lloyd and L. Viola, Phys. Rev. A 65, 010101 (2001), 10.1103/PhysRevA.65.010101 and E. Andersson and D. K. L. Oi, Phys. Rev. A 77, 052104 (2008), 10.1103/PhysRevA.77.052104] to superconducting circuits, featuring a single qubit ancilla with quantum nondemolition readout and adaptive control. This construction is efficient in both ancilla dimension and circuit depth. We point out various applications of quantum channel construction, including system stabilization and quantum error correction, Markovian and exotic channel simulation, implementation of generalized quantum measurements, and more general quantum instruments. Efficient construction of arbitrary quantum channels opens up exciting new possibilities for quantum control, quantum sensing, and information processing tasks.

  1. Active Brownian motion in a narrow channel

    Science.gov (United States)

    Ao, X.; Ghosh, P. K.; Li, Y.; Schmid, G.; Hänggi, P.; Marchesoni, F.

    2014-12-01

    We review recent advances in rectification control of artificial microswimmers, also known as Janus particles, diffusing along narrow, periodically corrugated channels. The swimmer self-propulsion mechanism is modeled so as to incorporate a nonzero torque (propulsion chirality). We first summarize the effects of chirality on the autonomous current of microswimmers freely diffusing in channels of different geometries. In particular, left-right and upside-down asymmetric channels are shown to exhibit different transport properties. We then report new results on the dependence of the diffusivity of chiral microswimmers on the channel geometry and their own self-propulsion mechanism. The self-propulsion torque turns out to play a key role as a transport control parameter.

  2. Rip Channel Migration in the Nearshore

    National Research Council Canada - National Science Library

    Minetree, Courtney M

    2006-01-01

    Video imaging data generated from the Naval Postgraduate School Imaging System (NAPSIS) during November 2004 to June 2006 was analyzed to determine the location of rip channels and track their morphology...

  3. Piezo1 Channels Are Inherently Mechanosensitive

    Directory of Open Access Journals (Sweden)

    Ruhma Syeda

    2016-11-01

    Full Text Available The conversion of mechanical force to chemical signals is critical for many biological processes, including the senses of touch, pain, and hearing. Mechanosensitive ion channels play a key role in sensing the mechanical stimuli experienced by various cell types and are present in organisms from bacteria to mammals. Bacterial mechanosensitive channels are characterized thoroughly, but less is known about their counterparts in vertebrates. Piezos have been recently established as ion channels required for mechanotransduction in disparate cell types in vitro and in vivo. Overexpression of Piezos in heterologous cells gives rise to large mechanically activated currents; however, it is unclear whether Piezos are inherently mechanosensitive or rely on alternate cellular components to sense mechanical stimuli. Here, we show that mechanical perturbations of the lipid bilayer alone are sufficient to activate Piezo channels, illustrating their innate ability as molecular force transducers.

  4. Theory of Alike Selectivity in Biological Channels

    Science.gov (United States)

    Luchinsky, Dmitry G.; Gibby, Will A. T.; Kaufman, Igor Kh.; Eisenberg, Robert S.; McClintock, Peter V. E.

    2016-01-01

    We introduce a statistical mechanical model of the selectivity filter that accounts for the interaction between ions within the channel and derive Eisenman equation of the filter selectivity directly from the condition of barrier-less conduction.

  5. Nonperturbative approach to relativistic quantum communication channels

    Science.gov (United States)

    Landulfo, André G. S.

    2016-05-01

    We investigate the transmission of both classical and quantum information between two arbitrary observers in globally hyperbolic spacetimes using a quantum field as a communication channel. The field is supposed to be in some arbitrary quasifree state and no choice of representation of its canonical commutation relations is made. Both sender and receiver possess some localized two-level quantum system with which they can interact with the quantum field to prepare the input and receive the output of the channel, respectively. The interaction between the two-level systems and the quantum field is such that one can trace out the field degrees of freedom exactly and thus obtain the quantum channel in a nonperturbative way. We end the paper determining the unassisted as well as the entanglement-assisted classical and quantum channel capacities.

  6. Flame Dynamics inside Rectangular Meso scale Channels

    Science.gov (United States)

    Anwar, Muzammil; Naseer Mohammad, Abdul; Mohammad, Akram; Juhany, Khalid A.

    2018-03-01

    The present work is focused on the experimental study of flame dynamics in preheated meso-scale straight channels of various aspect ratios (2, 5, 12 and 15) and inlet dimensions.Premixed methane-air mixture were used for the reported experiments. To maintain a positive wall temperature gradient inside the channel, the lower part of the rectangular channels were heated at a constant temperature using an external electric heater. Laminar premixed flames were stabilized inside these channels. Various flame propagation modes such as concave, planar, and convex flames with respect to unburned mixture. Concave flames lead to flashback whereas convex flames lead to blowout. Increase in aspect ratio and decrease of flow velocity leads to flame flashback.

  7. Lossy Channel Games under Incomplete Information

    Directory of Open Access Journals (Sweden)

    Rayna Dimitrova

    2013-03-01

    Full Text Available In this paper we investigate lossy channel games under incomplete information, where two players operate on a finite set of unbounded FIFO channels and one player, representing a system component under consideration operates under incomplete information, while the other player, representing the component's environment is allowed to lose messages from the channels. We argue that these games are a suitable model for synthesis of communication protocols where processes communicate over unreliable channels. We show that in the case of finite message alphabets, games with safety and reachability winning conditions are decidable and finite-state observation-based strategies for the component can be effectively computed. Undecidability for (weak parity objectives follows from the undecidability of (weak parity perfect information games where only one player can lose messages.

  8. Studying Kv Channels Function using Computational Methods.

    Science.gov (United States)

    Deyawe, Audrey; Kasimova, Marina A; Delemotte, Lucie; Loussouarn, Gildas; Tarek, Mounir

    2018-01-01

    In recent years, molecular modeling techniques, combined with MD simulations, provided significant insights on voltage-gated (Kv) potassium channels intrinsic properties. Among the success stories are the highlight of molecular level details of the effects of mutations, the unraveling of several metastable intermediate states, and the influence of a particular lipid, PIP 2 , in the stability and the modulation of Kv channel function. These computational studies offered a detailed view that could not have been reached through experimental studies alone. With the increase of cross disciplinary studies, numerous experiments provided validation of these computational results, which endows an increase in the reliability of molecular modeling for the study of Kv channels. This chapter offers a description of the main techniques used to model Kv channels at the atomistic level.

  9. Multi-channel gas-delivery system

    Energy Technology Data Exchange (ETDEWEB)

    Rozenzon, Yan; Trujillo, Robert T.; Beese, Steven C.

    2016-09-13

    One embodiment of the present invention provides a gas-delivery system for delivering reaction gas to a reactor chamber. The gas-delivery system includes a main gas-inlet port for receiving reaction gases and a gas-delivery plate that includes a plurality of gas channels. A gas channel includes a plurality of gas holes for allowing the reaction gases to enter the reactor chamber from the gas channel. The gas-delivery system further includes a plurality of sub-gas lines coupling together the main gas-inlet port and the gas-delivery plate, and a respective sub-gas line is configured to deliver a portion of the received reaction gases to a corresponding gas channel.

  10. Modified MIMO Cube for Enhanced Channel Capacity

    Directory of Open Access Journals (Sweden)

    Lajos Nagy

    2012-01-01

    Full Text Available This paper deals with the optimization of MIMO antenna elements' position in modified MIMO cube for getting maximal channel capacity in indoor environment. The dependence of the channel capacity on the antenna orientation was analyzed by simulations. We have also examined the effect of the frequency dependence of the antenna system (in case of conjugate matching and nonconjugate matching for the channel capacity. Based on the simulation results in the created and measured antenna system, the antennas were at a right angle to each other. At the two chosen different structures, we measured the antenna parameters and the channel capacity. In this paper, we present the results of the measurements which clearly confirm our simulations. We will point out the differences between the two antenna structures.

  11. ULYSSES JUPITER EPAC ALL DATA CHANNELS

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains Ulysses Energetic Particle Composition Experiment (EPAC) 1 hour averaged proton and electron flux data from all data channels submitted from...

  12. Spatial Modulation in the Underwater Acoustic Communication Channel

    National Research Council Canada - National Science Library

    Kilfoyle, Daniel

    2000-01-01

    .... The technique, termed spatial modulation, seeks to control the spatial distribution of signal energy such that multiple parallel communication channels are supported by the single, physical ocean channel...

  13. Spinal Gap Junction Channels in Neuropathic Pain

    OpenAIRE

    Jeon, Young Hoon; Youn, Dong Ho

    2015-01-01

    Damage to peripheral nerves or the spinal cord is often accompanied by neuropathic pain, which is a complex, chronic pain state. Increasing evidence indicates that alterations in the expression and activity of gap junction channels in the spinal cord are involved in the development of neuropathic pain. Thus, this review briefly summarizes evidence that regulation of the expression, coupling, and activity of spinal gap junction channels modulates pain signals in neuropathic pain states induced...

  14. Environmental Modeling of Storm Water Channels

    OpenAIRE

    L. Grinis

    2014-01-01

    Turbulent flow in complex geometries receives considerable attention due to its importance in many engineering applications. It has been the subject of interest for many researchers. Some of these interests include the design of storm water channels. The design of these channels requires testing through physical models. The main practical limitation of physical models is the so called “scale effect”, that is, the fact that in many cases only primary physical mechanisms can be correctly repres...

  15. Cooperative communications hardware, channel and PHY

    CERN Document Server

    Dohler, Mischa

    2010-01-01

    Facilitating Cooperation for Wireless Systems Cooperative Communications: Hardware, Channel & PHY focuses on issues pertaining to the PHY layer of wireless communication networks, offering a rigorous taxonomy of this dispersed field, along with a range of application scenarios for cooperative and distributed schemes, demonstrating how these techniques can be employed. The authors discuss hardware, complexity and power consumption issues, which are vital for understanding what can be realized at the PHY layer, showing how wireless channel models differ from more traditional

  16. The TRIUMF stopped π-μ channel

    International Nuclear Information System (INIS)

    Al-Qazzaz, N.M.M.; Beer, G.A.; Mason, G.R.

    1980-01-01

    The TRIUMF π-μ channel (M9) is described and the measured optical paramters are compared with design values. Measured beam characteristics of pions and muons for several different momenta are reported for protons incident on Be and Cu production targets. A beam of cloud muons at the channel momentum, from π decays near the production target, has been obtained having a high stopping density and small spot size. (auth)

  17. Dechanneling function for relativistic axially channeled electrons

    International Nuclear Information System (INIS)

    Muralev, V.A.; Telegin, V.I.

    1981-01-01

    Behaviour of the x(t) dechanneling function depending on the depth is theoretically studied. Theoretical consideration of x(t) for axial channeled relativistic electrons in anisotropic medium results in two-dimensional kinetic equation with mixed derivatives of the parabolic type. The kinetic equation in the approximation of the continuous Lindchard model for relativistic axial channeled electrons is numerically solved. The depth dependence of the x(t) dechanneling function is obtained [ru

  18. Channels of distribution on tourist market

    Directory of Open Access Journals (Sweden)

    Đelić Tanja A.

    2005-01-01

    Full Text Available Changes in distribution channels in tourist industry, made as a result of introducing online CRS and Internet, enabled tourist companies offer their products in electronic way to end-users without using agents. In that way technology improvement results in change of the structure of sale channels in the whole tourist market and online orders are growing, as well as the use of agencies are diminishing.

  19. The Business Cluster's Distribution e-Channels

    OpenAIRE

    Milan Davidovic

    2011-01-01

    The business cluster cooperative potential and business capability improvement are dependent on e-business implementation and business model change dynamics in cluster and his members based in new and existing distribution channels, customer relationships management and supplychain integration. In this work analyse cluster’s e-business models, e-commerce forms and distribution e-channels for three business cases: when cluster members are oriented on own business, on cooperative’s project or c...

  20. Vertical transmission of channel catfish virus.

    Science.gov (United States)

    Wise, J A; Harrell, S F; Busch, R L; Boyle, J A

    1988-09-01

    Channel catfish broodfish were examined nondestructively for the presence of channel catfish virus (CCV), using a nucleic acid-probing technique. A dot blot assay was tested and shown to be accurate and rapid in the diagnosis of CCV. Two CCV-positive fish were successfully mated, and fertilized eggs were collected. Offspring that hatched were tested and were shown to have CCV. This result indicated vertical transmission of CCV, a herpesvirus.

  1. Store-Operated Calcium Channel and Cancer

    OpenAIRE

    Yang S; Chang WC

    2012-01-01

    The increase of intracellular Ca2+ concentration is an important mechanism that regulates a variety of physiological processes ranging from exocytosis to gene regulation and cell proliferation [1]. Calcium release from intracellular stores (mainly endoplasmic reticulum, ER) or calcium entry through calcium channels can be used by cells to evoke a higher level of cytosolic Ca2+ concentration. In non-excitable cells, a major pathway for Ca2+ influx is via store-operated Ca2+ channels (also know...

  2. Discovery and Development of Calcium Channel Blockers

    OpenAIRE

    Godfraind, Théophile

    2017-01-01

    In the mid 1960s, experimental work on molecules under screening as coronary dilators allowed the discovery of the mechanism of calcium entry blockade by drugs later named calcium channel blockers. This paper summarizes scientific research on these small molecules interacting directly with L-type voltage-operated calcium channels. It also reports on experimental approaches translated into understanding of their therapeutic actions. The importance of calcium in muscle contraction was discovere...

  3. Bayesian Inference Methods for Sparse Channel Estimation

    DEFF Research Database (Denmark)

    Pedersen, Niels Lovmand

    2013-01-01

    of Bayesian inference algorithms for sparse channel estimation. Sparse inference methods aim at finding the sparse representation of a signal given in some overcomplete dictionary of basis vectors. Within this context, one of our main contributions to the field of SBL is a hierarchical representation...... and computational complexity. We also analyze the impact of transceiver filters on the sparseness of the channel response, and propose a dictionary design that permits the deployment of sparse inference methods in conditions of low bandwidth....

  4. Development of a tuneable channel cut crystal

    Science.gov (United States)

    Treimer, W.; Strobl, M.; Hilger, A.

    2001-10-01

    We have developed the first tuneable channel cut crystal for ultra small angle neutron scattering and neutron optical experiments. The Darwin range of a perfect crystal can be reduced down to a fraction of its natural width. This “Darwin reduction” was realised without any change of the beam geometry which yields an intensity gain relative to conventional asymmetric Bragg diffraction. With such tuneable channel cut crystal peaks nearly δ-peaks can experimentally be realised.

  5. Effect of Coriolis and centrifugal forces on flow and heat transfer at high rotation number and high density ratio in non orthogonally internal cooling channel

    Directory of Open Access Journals (Sweden)

    Brahim Berrabah

    2017-02-01

    Full Text Available Numerical predictions of three-dimensional flow and heat transfer are performed for a two-pass square channel with 45° staggered ribs in non-orthogonally mode-rotation using the second moment closure model. At Reynolds number of 25,000, the rotation numbers studied were 0, 0.24, 0.35 and 1.00. The density ratios were 0.13, 0.23 and 0.50. The results show that at high buoyancy parameter and high rotation number with a low density ratio, the flow in the first passage is governed by the secondary flow induced by the rotation whereas the secondary flow induced by the skewed ribs was almost distorted. As a result the heat transfer rate is enhanced on both co-trailing and co-leading sides compared to low and medium rotation number. In contrast, for the second passage, the rotation slightly reduces the heat transfer rate on co-leading side at high rotation number with a low density ratio and degrades it significantly on both co-trailing and co-leading sides at high buoyancy parameter compared to the stationary, low and medium rotation numbers. The numerical results are in fair agreement with available experimental data in the bend region and the second passage, while in the first passage were overestimated at low and medium rotation numbers.

  6. Joint source/channel coding of scalable video over noisy channels

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, G.; Zakhor, A. [Department of Electrical Engineering and Computer Sciences University of California Berkeley, California94720 (United States)

    1997-01-01

    We propose an optimal bit allocation strategy for a joint source/channel video codec over noisy channel when the channel state is assumed to be known. Our approach is to partition source and channel coding bits in such a way that the expected distortion is minimized. The particular source coding algorithm we use is rate scalable and is based on 3D subband coding with multi-rate quantization. We show that using this strategy, transmission of video over very noisy channels still renders acceptable visual quality, and outperforms schemes that use equal error protection only. The flexibility of the algorithm also permits the bit allocation to be selected optimally when the channel state is in the form of a probability distribution instead of a deterministic state. {copyright} {ital 1997 American Institute of Physics.}

  7. Research on Spatial Channel Model for Vehicle-to-Vehicle Communication Channel in Roadside Scattering Environment

    Directory of Open Access Journals (Sweden)

    Xin Chen

    2017-01-01

    Full Text Available In this paper, an extension of spatial channel model (SCM for vehicle-to-vehicle (V2V communication channel in roadside scattering environment is investigated for the first time theoretically and by simulations. Subsequently, to efficiently describe the roadside scattering environment and reflect the nonstationary properties of V2V channels, the proposed SCM V2V model divides the scattering objects into three categories of clusters according to the location of effective scatterers by introducing critical distance. We derive general expressions for the most important statistical properties of V2V channels, such as channel impulse response, power spectral density, angular power density, autocorrelation function, and Doppler spread of the proposed model. The impact of vehicle speed, traffic density, and angle of departure, angle of arrival, and other statistical performances on the V2V channel model is thoroughly discussed. Numerical simulation results are presented to validate the accuracy and effectiveness of the proposed model.

  8. Efficient Channel Management Mechanism to Enhance Channel Utilization for Sensing Data Delivery in Vehicular Ad Hoc Networks

    OpenAIRE

    Tsogoo, Buyandelger; Yoo, Sang-Jo

    2015-01-01

    IEEE 1609.4 defines MAC layer implementation in a vehicular ad hoc network (VANET). In IEEE 1609.4 multichannel operation, the control channel interval (CCHI) and the service channel interval (SCHI) are defined such that service channels cannot be utilized during the CCHI, and vice versa, which leads to poor utilization of scarce spectrum resources. In this paper, we propose a multi-schedule-based channel switching mechanism to improve channel utilization and uniformly distribute channel load...

  9. A novel potassium channel in photosynthetic cyanobacteria.

    Directory of Open Access Journals (Sweden)

    Manuela Zanetti

    Full Text Available Elucidation of the structure-function relationship of a small number of prokaryotic ion channels characterized so far greatly contributed to our knowledge on basic mechanisms of ion conduction. We identified a new potassium channel (SynK in the genome of the cyanobacterium Synechocystis sp. PCC6803, a photosynthetic model organism. SynK, when expressed in a K(+-uptake-system deficient E. coli strain, was able to recover growth of these organisms. The protein functions as a potassium selective ion channel when expressed in Chinese hamster ovary cells. The location of SynK in cyanobacteria in both thylakoid and plasmamembranes was revealed by immunogold electron microscopy and Western blotting of isolated membrane fractions. SynK seems to be conserved during evolution, giving rise to a TPK (two-pore K(+ channel family member which is shown here to be located in the thylakoid membrane of Arabidopsis. Our work characterizes a novel cyanobacterial potassium channel and indicates the molecular nature of the first higher plant thylakoid cation channel, opening the way to functional studies.

  10. Evaporative Lithography in Open Microfluidic Channel Networks

    KAUST Repository

    Lone, Saifullah

    2017-02-24

    We demonstrate a direct capillary-driven method based on wetting and evaporation of various suspensions to fabricate regular two-dimensional wires in an open microfluidic channel through continuous deposition of micro- or nanoparticles under evaporative lithography, akin to the coffee-ring effect. The suspension is gently placed in a loading reservoir connected to the main open microchannel groove on a PDMS substrate. Hydrophilic conditions ensure rapid spreading of the suspension from the loading reservoir to fill the entire channel length. Evaporation during the spreading and after the channel is full increases the particle concentration toward the end of the channel. This evaporation-induced convective transport brings particles from the loading reservoir toward the channel end where this flow deposits a continuous multilayered particle structure. The particle deposition front propagates backward over the entire channel length. The final dry deposit of the particles is thereby much thicker than the initial volume fraction of the suspension. The deposition depth is characterized using a 3D imaging profiler, whereas the deposition topography is revealed using a scanning electron microscope. The patterning technology described here is robust and passive and hence operates without an external field. This work may well become a launching pad to construct low-cost and large-scale thin optoelectronic films with variable thicknesses and interspacing distances.

  11. On conduction in a bacterial sodium channel.

    Directory of Open Access Journals (Sweden)

    Simone Furini

    Full Text Available Voltage-gated Na⁺-channels are transmembrane proteins that are responsible for the fast depolarizing phase of the action potential in nerve and muscular cells. Selective permeability of Na⁺ over Ca²⁺ or K⁺ ions is essential for the biological function of Na⁺-channels. After the emergence of the first high-resolution structure of a Na⁺-channel, an anionic coordination site was proposed to confer Na⁺ selectivity through partial dehydration of Na⁺ via its direct interaction with conserved glutamate side chains. By combining molecular dynamics simulations and free-energy calculations, a low-energy permeation pathway for Na⁺ ion translocation through the selectivity filter of the recently determined crystal structure of a prokaryotic sodium channel from Arcobacter butzleri is characterised. The picture that emerges is that of a pore preferentially occupied by two ions, which can switch between different configurations by crossing low free-energy barriers. In contrast to K⁺-channels, the movements of the ions appear to be weakly coupled in Na⁺-channels. When the free-energy maps for Na⁺ and K⁺ ions are compared, a selective site is characterised in the narrowest region of the filter, where a hydrated Na⁺ ion, and not a hydrated K⁺ ion, is energetically stable.

  12. Inhibitory effects of imperatorin on voltage-gated K(+) channels and ATP-sensitive K(+) channels.

    Science.gov (United States)

    Wang, Yu-Wen; Yang, Chin-Tsang; Chen, Yi-Hung; Gong, Chi-Li; Chen, Yu-Fang; Kuo, Yueh-Hsiung; Leung, Yuk-Man

    2015-02-01

    Imperatorin is a furocoumarin isolated from Angelica archangelica and Cnidium monnieri. It has multiple neuromodulatory actions such as anticonvulsant effects, anxiolytic effects and anti-nociceptive effects. Although there have been reports demonstrating its effects on voltage-gated Na(+) channels (VGSC) and transient reversal potential (TRP) V1 channels in neurons, there is hitherto no work showing whether this compound affects voltage-gated K(+) (Kv) channels and ATP-sensitive K(+) (KATP) channels. We investigated the effects of imperatorin on K(+) channels using whole-cell configuration voltage-clamp technique. Imperatorin inhibited Kv channels in differentiated neuronal NG108-15 cells, and caused a left shift in the steady-state inactivation curve without affecting activation gating. Imperatorin also inhibited heterologously expressed wild type Kv1.2 and Kv2.1 channels, but became much less potent in inhibiting Kv1.2 V370G, a mutant defective in C-type inactivation, implying that drug inhibition depends on C-type inactivation. At a high concentration (100μM), imperatorin also suppressed KATP channels. Our results suggest that imperatorin inhibited both Kv and KATP channels. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  13. On the secrecy capacity of the MISO wiretap channel under imperfect channel estimation

    KAUST Repository

    Rezki, Zouheir

    2014-12-01

    We consider a wiretap channel consisting of a source with multiple antennas, a legitimate receiver and an eavesdropper with a single antenna each. The channels between the source and the receivers undergo fast fading. We assume that the transmitter, in addition to the statistics of both channels, is only aware of a noisy version of the CSI to the legitimate receiver referred to as main channel. The legitimate receiver is aware of both its instantaneous channel gain and the transmitter\\'s estimate of the main channel. On the other hand, the eavesdropper\\'s receiver, in addition to its instantaneous channel realization, is aware of the actual main CSI and the transmitter\\'s estimate as well. While the capacity of this channel is still open even with perfect CSI at the transmitter, we provide in this paper upper and lower bounds on the secrecy capacity. The upper bound is tighter than the one corresponding to perfect main CSI and the gap between the two upper bounds is characterized in function of the channel estimation error variance, at high-SNR. Furthermore, we show that our upper and lower bounds coincide in the case of no main CSI providing a trivial secrecy capacity.

  14. Morphological dynamics of an englacial channel

    Science.gov (United States)

    Vatne, Geir; Irvine-Fynn, Tristram D. L.

    2016-07-01

    Despite an interest in the hydraulic functioning of supraglacial and englacial channels over the last 4 decades, the processes and forms of such ice-bounded streams have remained poorly documented. Recent glaciological research has demonstrated the potential significance of so-called "cut-and-closure" streams, where englacial or subglacial flow paths are created from the long-term incision of supraglacial channels. These flow paths are reported to exhibit step-pool morphology, comprising knickpoints and/or knickzones, exaggerated in dimensions in comparison to supraglacial channels. However, little is known of the development of such channels' morphology. Here, we examine the spatial organisation of step pools and the upstream migration of steps, many of which form knickzones, with repeated surveys over a 10-year period in an englacial conduit in cold-based Austre Brøggerbreen, Svalbard. The observations show upstream step recession to be the dominant process for channel evolution. This is paralleled by an increase in average step height and conduit gradient over time. Characteristic channel-reach types and step-riser forms are consistently observed in each of the morphological surveys reported. We suggest that the formation of steps has a hydrodynamic origin, where step-pool geometry is more efficient for energy dissipation than meanders. The englacial channel system is one in rapid transition towards a quasi-equilibrium form within a decadal timescale. The evolution and recession of knickzones reported here result in the formation of a 37 m deep moulin shaft, suggesting that over time an incising supraglacial channel may evolve towards an englacial channel form exhibiting a stable end-point characterised by a singular vertical descent, which potentially can reach the glacier bed. This challenges the prevailing notions that crevasses or hydrofractures are needed to form deep moulins. Our observations highlight the need to further examine the adjustment processes

  15. The human role in changing river channels

    Science.gov (United States)

    Gregory, K. J.

    2006-09-01

    Direct consequences of the human role, where human activity affects river channels through engineering works including channelization, dam construction, diversion and culverting, have been long recognised [Marsh, G.P., 1864. Man and Nature or Physical Geography as Modified by Human Action. Charles Scribner, New York; Thomas Jr., W.L., (ed.) 1956. Man's Role in Changing the Face of the Earth. Chicago, University of Chicago Press, Chicago.]. The less obvious indirect effects of point and reach changes occurring downstream and throughout the basin, however, are much more recently appreciated, dating from key contributions by Strahler [Strahler, A.N., 1956. The nature of induced erosion and aggradation. In W. L. Thomas (Ed.), Man's Role in Changing the Face of the Earth. University of Chicago Press, Chicago, 621-638.], Wolman [Wolman, M.G., 1967. A cycle of sedimentation and erosion in urban river channels. Geografiska Annaler 49A, 385-95.], Schumm [Schumm, S.A., 1969. River metamorphosis. Proceedings American Society of Civil Engineers, Journal Hydraulics Division 95, 255-73.], and Graf [Graf, W.L., 1977. The rate law in fluvial geomorphology. American Journal of Science, 277, 178-191.]. These are complemented by effects of alterations of land use, such as deforestation, intensive agriculture and incidence of fire, with the most extreme effects produced by building activity and urbanisation. Changing river channels are most evident in the channel cross-section where changes of size, shape and composition are now well-established, with up to tenfold increases or decreases illustrated by results from more than 200 world studies. In addition the overall channel planform, the network and the ecology have changed. Specific terms have become associated with changing river channels including enlargement, shrinkage and metamorphosis. Although the scope of adjustment has been established, it has not always been possible to predict what will happen in a particular location

  16. Secure Broadcasting with Uncertain Channel State Information

    KAUST Repository

    Hyadi, Amal

    2017-03-13

    We investigate the problem of secure broadcasting over fast fading channels with imperfect main channel state information (CSI) at the transmitter. In particular, we analyze the effect of the noisy estimation of the main CSI on the throughput of a broadcast channel where the transmission is intended for multiple legitimate receivers in the presence of an eavesdropper. Besides, we consider the realistic case where the transmitter is only aware of the statistics of the eavesdropper\\'s CSI and not of its channel\\'s realizations. First, we discuss the common message transmission case where the source broadcasts the same information to all the receivers, and we provide an upper and a lower bounds on the ergodic secrecy capacity. For this case, we show that the secrecy rate is limited by the legitimate receiver having, on average, the worst main channel link and we prove that a non-zero secrecy rate can still be achieved even when the CSI at the transmitter is noisy. Then, we look at the independent messages case where the transmitter broadcasts multiple messages to the receivers, and each intended user is interested in an independent message. For this case, we present an expression for the achievable secrecy sum-rate and an upper bound on the secrecy sum-capacity and we show that, in the limit of large number of legitimate receivers K, our achievable secrecy sum-rate follows the scaling law log((1-a ) log(K)), where is the estimation error variance of the main CSI. The special cases of high SNR, perfect and no-main CSI are also analyzed. Analytical derivations and numerical results are presented to illustrate the obtained expressions for the case of independent and identically distributed Rayleigh fading channels.

  17. PERFORMANCE CHARACTERISTICS OF HERRINGBONE-GROOVED JOURNAL BEARINGS OPERATING AT HIGH ECCENTRICITY RATIOS AND WITH MISALIGNMENT.

    Science.gov (United States)

    journal bearing with compressible lubricant is solved by the numerical method of matrix influence coefficients for the case of arbitrary eccentricity and misalignment. Performance characteristics are presented for one particular bearing over the range 0 < Lambda < 20. Results are presented showing the restoring moment due to misalignment, the effect of L/D ratio at large eccentricity and the influence of eccentricity ratio on the optimum values of groove parameters for maximum radial stiffness. Comparison is made with experimental results.

  18. Modified herringbone reconstruction on Au(1 1 1) induced by self-assembled Azure A islands

    Science.gov (United States)

    Rossel, Frédéric; Brodard, Pierre; Patthey, François; Richardson, Neville V.; Schneider, Wolf-Dieter

    2008-07-01

    Upon submonolayer deposition of Azure A molecules onto reconstructed Au(1 1 1), two-dimensional quasi-rectangular islands are observed by low-temperature scanning tunneling microscopy. Strikingly, the 22 × √3 reconstruction with alternating hexagonal close packed (hcp) and face centered cubic (fcc) domains of the native Au(1 1 1) surface layer is found to be strongly modified underneath the self-assembled islands of Azure A molecules. The bridge-hcp-bridge-fcc-bridge period of 63 Å on clean Au(1 1 1) is expanded by about 12% and occasionally reaches even 22%. This increase of the unreconstructed fcc areas underneath the molecular islands reflects a partial lifting of the reconstruction caused by the interaction between the adsorbed molecules and the outermost Au atoms at the molecule-metal interface.

  19. Design curves for optimizing stability of herringbone-grooved journal bearings

    Science.gov (United States)

    Fleming, D. P.; Hamrock, B. J.

    1973-01-01

    Curves span wide range of operating conditions, including: lubricant compressibility numbers from 0 to 80, bearing length-to-diameter ratios from 1/4 to 2, and either rotating or stationary grooved members.

  20. Unsupervised Idealization of Ion Channel Recordings by Minimum Description Length: Application to Human PIEZO1-Channels

    Directory of Open Access Journals (Sweden)

    Jakob K. Dreyer

    2017-04-01

    Full Text Available Researchers can investigate the mechanistic and molecular basis of many physiological phenomena in cells by analyzing the fundamental properties of single ion channels. These analyses entail recording single channel currents and measuring current amplitudes and transition rates between conductance states. Since most electrophysiological recordings contain noise, the data analysis can proceed by idealizing the recordings to isolate the true currents from the noise. This de-noising can be accomplished with threshold crossing algorithms and Hidden Markov Models, but such procedures generally depend on inputs and supervision by the user, thus requiring some prior knowledge of underlying processes. Channels with unknown gating and/or functional sub-states and the presence in the recording of currents from uncorrelated background channels present substantial challenges to such analyses. Here we describe and characterize an idealization algorithm based on Rissanen's Minimum Description Length (MDL Principle. This method uses minimal assumptions and idealizes ion channel recordings without requiring a detailed user input or a priori assumptions about channel conductance and kinetics. Furthermore, we demonstrate that correlation analysis of conductance steps can resolve properties of single ion channels in recordings contaminated by signals from multiple channels. We first validated our methods on simulated data defined with a range of different signal-to-noise levels, and then showed that our algorithm can recover channel currents and their substates from recordings with multiple channels, even under conditions of high noise. We then tested the MDL algorithm on real experimental data from human PIEZO1 channels and found that our method revealed the presence of substates with alternate conductances.