WorldWideScience

Sample records for bundle thermohydraulic transients

  1. Transient thermohydraulic heat pipe modeling

    Science.gov (United States)

    Hall, Michael L.; Doster, Joseph M.

    Many space based reactor designs employ heat pipes as a means of conveying heat. In these designs, thermal radiation is the principle means for rejecting waste heat from the reactor system, making it desirable to operate at high temperatures. Lithium is generally the working fluid of choice as it undergoes a liquid-vapor transformation at the preferred operating temperature. The nature of remote startup, restart, and reaction to threats necessitates an accurate, detailed transient model of the heat pipe operation. A model is outlined of the vapor core region of the heat pipe which is part of a large model of the entire heat pipe thermal response. The vapor core is modeled using the area averaged Navier-Stokes equations in one dimension, which take into account the effects of mass, energy and momentum transfer. The core model is single phase (gaseous), but contains two components: lithium gas and a noncondensible vapor. The vapor core model consists of the continuity equations for the mixture and noncondensible, as well as mixture equations for internal energy and momentum.

  2. The combined thermohydraulics-neutronics code TRAB-SMABRE for 3D plant transient and accident analyses

    Energy Technology Data Exchange (ETDEWEB)

    Jaakko, M.; Antti, D.; Hanna, R.; Timo, V. [VTT Processes, (Finland)

    2004-07-01

    TRAB-3D models the PWR and BWR reactor core using the two-group diffusion equations in homogenized fuel assembly geometry with a sophisticated nodal method. Thermohydraulics is described using four equation formulation. The stand-alone version of the code also describes thermohydraulics of the rest of the BWR circuit with one dimensional components. The SMABRE code models the thermohydraulics of light water reactors. The five equation formulation with the drift flux phase separation is modelling the two-phase behaviour. Conservation equations are solved for the phase mass, mixture momentum and phase energy. Additional equations are for the noncondensable part in gas and boron in liquid. The TRAB-3D and SMABRE codes have been coupled earlier by using the parallel coupling principle, where in the core section the 3-dimensional TRAB core, and the parallel channel coarse SMABRE core are solved in parallel, but the rest of the circulation system is solved with SMABRE. As a new development the internal coupling to meet new requirements for the PWR and BWR transient analyses is being realised. Both the circuit and core thermohydraulics are solved in SMABRE. The core thermohydraulics solution inside the core wide iterations is repeated to allow rapid power changes. These are the fast pressure changes, control rod ejection and ATWS. The numerical solution in SMABRE has been improved to allow full core simulation with separate flow channel for each fuel element of a BWR core. For the PWR plants the method is used as well by simulating the core by one-dimensional parallel channels. New development is needed for the open core calculation. (authors)

  3. The combined thermohydraulics-neutronics code TRAB-SMABRE for 3D plant transient and accident analyses

    Energy Technology Data Exchange (ETDEWEB)

    Jaakko Miettinen; Timo Vanttola; Hanna Raety; Antti Daavittila [VTT Processes, P.O.Box 1604, FIN-02044 VTT (Finland)

    2005-07-01

    Full text of publication follows: TRAB-3D models the PWR and BWR reactor core using the two-group diffusion equations in homogenized fuel assembly geometry with a sophisticated nodal method. Thermohydraulics is described using four-equation formulation. The stand-alone version of the code also describes thermohydraulics of the rest of the BWR circuit with one-dimensional components. The SMABRE code models the thermohydraulics of light water reactors. The five-equation formulation with the drift flux phase separation is modelling the two-phase behaviour. Conservation equations are solved for the phase mass, mixture momentum and phase energy. Additional equations are for the noncondensable in gas and boron in liquid. The TRAB-3D and SMABRE codes have been coupled earlier by using the parallel coupling principle, where in the core section the 3-dimensional TRAB core, and the parallel channel coarse SMABRE core are solved in parallel, but rest of the circulation system is solved with SMABRE. As a new development the internal coupling to meet new requirements for the PWR and BWR transient analyses is being realised. Both the circuit and core thermohydraulics are solved in SMABRE. The core thermohydraulics solution inside the core wide iterations is repeated to allow rapid power changes. These are the fast pressure changes, control rod ejection and ATWS. The numerical solution in SMABRE has been improved to allow full core simulation with separate flow channel for each fuel element of a BWR core. For the PWR plants the method is used as well by simulating the core by one-dimensional parallel channels. New development is needed for the open core calculation. In general questions could be raised, what advantages are seen with the new internal coupling in comparison with the earlier realised parallel coupling, and which advantages may be seen in building the realtor physical model on the basis of the old code, developed since 1970's. The internal coupling allows

  4. Transient Left Bundle Branch Block due to Severe Hyperkalemia.

    Science.gov (United States)

    Kumar, Kishore; Biyyam, Madhavi; Singh, Amandeep; Bajantri, Bharat; Tariq, Hassan; Nayudu, Suresh Kumar; Chilimuri, Sridhar

    2017-04-01

    Hyperkalemia is a potentially life-threatening electrolyte imbalance that can lead to sudden death from cardiac arrhythmias and asystole. We present a case of transient left bundle branch block pattern on an electrocardiogram (ECG) secondary to hyperkalemia in a patient with history of end-stage renal disease. A 52-year-old man presented to the emergency room (ER) with chief complaints of weakness and lethargy after missing his regularly scheduled session of hemodialysis. A 12-lead ECG in the ER showed sinus tachycardia at 118 beats/min, wide QRS complexes, peaked T waves and left bundle branch block-like pattern. The initial basic metabolic panel revealed a serum potassium level of 8.8 mEq/L. Subsequently, the patient underwent emergent hemodialysis. Serum chemistry after hemodialysis showed improvement in serum potassium to 4.3 mEq/L. Repeat ECG performed after correcting potassium showed dissolution of left bundle branch block finding.

  5. Transient right bundle branch block in a patient with acute pulmonary embolism.

    Science.gov (United States)

    Gonzva, Jonathan; Viard, François-Valéry; Jost, Daniel; Lefort, Hugues; Tourtier, Jean-Pierre

    We report the case of an 86-year-old man found at home with acute chest pain and dyspnea. He presented some episodes of left chest pain combined with dyspnea. The physical examination revealed crackling sounds on the bases of the lungs without other anomalies. Electrocardiograms revealed a transient and complete right bundle branch block with inverted T waves in leads V1, V2, and V3. He was diagnosed with a proximal bilateral acute pulmonary embolism without acute cor pulmonale. We describe a case of a transient bundle branch block, without tachycardia or acute cor pulmonale, revealing a pulmonary embolism. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Heart Failure with Transient Left Bundle Branch Block in the Setting of Left Coronary Fistula

    Directory of Open Access Journals (Sweden)

    Stephen P. Juraschek

    2011-01-01

    Full Text Available Coronary arterial fistulas are rare communications between vessels or chambers of the heart. Although cardiac symptoms associated with fistulas are well described, fistulas are seldom considered in the differential diagnosis of acute myocardial ischemia. We describe the case of a 64-year-old man who presented with left shoulder pain, signs of heart failure, and a new left bundle branch block (LBBB. Cardiac catheterization revealed a small left anterior descending (LAD-to-pulmonary artery (PA fistula. Diuresis led to subjective improvement of the patient's symptoms and within several days the LBBB resolved. We hypothesize that the coronary fistula in this patient contributed to transient ischemia of the LAD territory through a coronary steal mechanism. We elected to observe rather than repair the fistula, as his symptoms and ECG changes resolved with treatment of his heart failure.

  7. [Intraoperative transient incomplete left bundle branch block in a patient with left axis deviation in pre-anesthetic electrocardiogram].

    Science.gov (United States)

    Sunaguchi, M; Imai, H; Shigemi, K; Imai, R; Ozaki, Y; Nakamura, Y; Tanaka, Y

    1998-11-01

    We encountered a case of transient incomplete left bundle branch block (TILBBB) during standard mastectomy under general anesthesia. The patient was a 40 year-old female (70 kg, 164 cm) without any abnormalities on preanesthetic examinations except -61 degrees left axis deviation in exercise electrocardiogram. Adriamycin 20 mg was administered preoperatively. After the skin incision, heart rate increased from 104 min-1 to 130 min-1 and the cardiac axis gradually rotated leftward with increasing Q wave depth on leads I and aVL. We diagnosed this as blockade of the anterior branch in the left bundle branch. After the administration of fentanyl (0.2 mg) and sevoflurane (3%), the heart rate decreased to 105 min-1 and the electrocardiogram returned to the initial wave form. This anesthetic course indicated that adriamycin had slightly damaged the cardiac muscle and inadequate anesthesia had caused tachycardia and transient left bundle branch block. Left axis deviation on preoperative exercise electrocardiogram suggests that the left bundle branch can easily be blocked with an increasing heart rate. Adequate depth of anesthesia would have prevented the increase in heart rate and abnormality in the cardiac conduction process.

  8. Investigation of combined free and forced convection in a 2 x 6 rod bundle during controlled flow transients

    Energy Technology Data Exchange (ETDEWEB)

    Bates, J.M.; Khan, E.U.

    1980-10-01

    An experimental study was performed to obtain local fluid velocity and temperature measurements in the mixed (combined free and forced) convection regime for specific flow coastdown transients. A brief investigation of steady-state flows for the purely free-convection regime was also completed. The study was performed using an electrically heated 2 x 6 rod bundle contained in a flow housing. In addition a transient data base was obtained for evaluating the COBRA-WC thermal-hydraulic computer program (a modified version of the COBRA-IV code).

  9. Coolant mixing in LMFBR rod bundles and outlet plenum mixing transients

    Science.gov (United States)

    Todreas, N. E.; Cheng, S. K.; Basehore, K.

    1984-08-01

    The thermal hydraulic performance of wire wrapped fuel bundles of LMFBR configuration was investigated. Results obtained included phenomenological models for friction factors, flow split and mixing characteristics; correlations for predicting these characteristics suitable for insertion in design codes; numerical codes for analyzing bundle behavior both of the lumped subchannel and distributed parameter categories and experimental techniques for pressure velocity, flow split, salt conductivity and temperature measurement in water cooled mockups of bundles and subchannels. Flow regimes investigated included laminar, transition and turbulent flow under forced convection and mixed convection conditions. Forced convections conditions are emphasized. Outlet plenum behavior is also investigated.

  10. Transient left bundle branch block induced by left-sided cardiac catheterization in patients without pre-existing conduction abnormalities.

    Science.gov (United States)

    Shimamoto, T; Nakata, Y; Sumiyoshi, M; Ogura, S; Takaya, J; Sakurai, H; Yamaguchi, H

    1998-02-01

    A traumatic left bundle branch block (LBBB) is uncommon in a patient with intact atrioventricular conduction. Three of our patients developed LBBB during a left-sided catheterization. Two patients suffered from angina pectoris and the other had an abdominal aneurysm. Two of them had a history of hypertension. None of the patients had ever shown any conduction abnormalities before the catheterization. The electrocardiogram just before the examination was normal in all 3 patients. LBBB was observed when a catheter was introduced into the left ventricle, and lasted 2--4 min without significant change in heart rates. Examination revealed no significant stenosis proximal to the first septal perforator and normal left ventricular contraction in all patients. One patient developed permanent LBBB 14 months later. Catheter-induced LBBB may occur easily with certain anatomical characteristics of the left bundle branch or the distal His bundle, with or without some concealed damage to the conduction system. It is important to keep this complication in mind and to pay adequate attention to patients' electrocardiograms as well as their angiographical findings, especially in those with pre-existing right bundle branch block.

  11. Obtaining of a simulator of thermohydraulics transients of the Cofrentes NPP using SNAP-TRACE platform; Obtencion de un simulador de transitorios termohidraulicos de la CN Cofrentes utilizando la plaraforma SNAP-TRACE

    Energy Technology Data Exchange (ETDEWEB)

    Escriva, A.; Munoz-cobo, J. L.; Concejal, A.; Soler, A.; Melara, J.; Albendea, M.

    2013-07-01

    The model developed using point kinetics and simulate various transients interactively, such as the firing of feed water turbo-pumps or the closing of the valves of main steam (MSIVs). Developed models allow to visualize, through different screens, the behavior of the whole plant as well as its control system.

  12. Thermo-hydraulic analysis of the windowless target system

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, Fosco [ENEA, Via Martiri di Monte Sole 4, 40129 Bologna (Italy)], E-mail: fosco.bianchi@bologna.enea.it; Ferri, Roberta [SIET, Via Nino Bixio 27, 29100 Piacenza (Italy); Moreau, Vincent [CRS4, Polaris Edificio 1 CP25, 09010 Pula (Canada) (Italy)

    2008-08-15

    The target system, whose function is to supply an external neutron source to a subcritical core in order to sustain the neutron chain reaction, is the most critical part of an ADS being subject to severe thermo-mechanical loading and material damage due to accelerator protons and fission neutrons. In order to reduce the material damage and to increase the life of the target system a windowless option was chosen in the framework of the European PDS-XADS project as reference configuration for the experimental ADS cooled by lead-bismuth eutectic alloy. This document deals with the results of the thermo-hydraulic analysis performed with STAR-CD and RELAP5 codes to assess the behaviour of the windowless target system during off-normal operating conditions. It also reports a description of modifications properly implemented in the codes for studying this kind of plant. The windowless target system shows a satisfactory thermo-hydraulic behaviour for the analysed accidents, except for the loss of both pumps without proton beam shut-off and for the beam trips lasting more than 1 s.

  13. Thermo-hydraulic design of earth-air heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    De Paepe, M. [Department of Flow, Heat and Combustion Mechanics, Ghent University, Ghent (Belgium); Janssens, A. [Department of Architecture and Urbanism, Ghent University, Ghent (Belgium)

    2003-07-01

    Earth-air heat exchangers, also called ground tube heat exchangers, are an interesting technique to reduce energy consumption in a building. They can cool or heat the ventilation air, using cold or heat accumulated in the soil. Several papers have been published in which a design method is described. Most of them are based on a discretisation of the one-dimensional heat transfer problem in the tube. Three-dimensional complex models, solving conduction and moisture transport in the soil are also found. These methods are of high complexity and often not ready for use by designers. In this paper, a one-dimensional analytical method is used to analyse the influence of the design parameters of the heat exchanger on the thermo-hydraulic performance. A relation is derived for the specific pressure drop, linking thermal effectiveness with pressure drop of the air inside the tube. The relation is used to formulate a design method which can be used to determine the characteristic dimensions of the earth-air heat exchanger in such a way that optimal thermal effectiveness is reached with acceptable pressure loss. The choice of the characteristic dimensions, becomes thus independent of the soil and climatological conditions. This allows designers to choose the earth-air heat exchanger configuration with the best performance. (author)

  14. Thermo-hydraulic design of earth-air heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Paepe, M. de [Ghent University (Belgium). Department of Flow, Heat and Combustion Mechanics; Janssens, A. [Ghent University (Belgium). Department of Architecture and Urbanism

    2003-05-01

    Earth-air heat exchangers, also called ground tube heat exchangers, are an interesting technique to reduce energy consumption in a building. They can cool or heat the ventilation air, using cold or heat accumulated in the soil. Several papers have been published in which a design method is described. Most of them are based on a discretisation of the one-dimensional heat transfer problem in the tube. Three-dimensional complex models, solving conduction and moisture transport in the soil are also found. These methods are of high complexity and often not ready for use by designers. In this paper, a one-dimensional analytical method is used to analyse the influence of the design parameters of the heat exchanger on the thermo-hydraulic performance. A relation is derived for the specific pressure drop, linking thermal effectiveness with pressure drop of the air inside the tube. The relation is used to formulate a design method which can be used to determine the characteristic dimensions of the earth-air heat exchanger in such a way that optimal thermal effectiveness is reached with acceptable pressure loss. The choice of the characteristic dimensions, becomes thus independent of the soil and climatological conditions. This allows designers to choose the earth-air heat exchanger configuration with the best performance. (author)

  15. Thermohydraulic design of saturated temperature capsule for IASCC irradiation test

    Energy Technology Data Exchange (ETDEWEB)

    Ide, Hiroshi; Matsui, Yoshinori; Itabashi, Yukio [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment] [and others

    2002-10-01

    An advanced water chemistry controlled irradiation research device is being developed in JAERI, to perform irradiation tests for irradiation assisted stress corrosion cracking (IASCC) research concerned with aging of LWR. This device enables the irradiation tests under the water chemistry condition and the temperature, which simulate the conditions for BWR core internals. The advanced water chemistry controlled irradiation research device is composed of saturated temperature capsule inserted into the JMTR core and the water chemistry control unit installed in the reactor building. Regarding the saturated temperature capsule, the Thermohydraulic design of capsule structure was done, aimed at controlling the specimen's temperature, feeding water velocity on specimen's surface to the environment of BWR nearer. As the result of adopting the new capsule structure based on the design study, it was found out that feeding water velocity at the surface of specimen's is increased to about 10 times as much as before, and nuclear heat generated in the capsule components can be removed safely even in the abnormal event such as the case of loss of feeding water. (author)

  16. Single Actin Bundle Rheology.

    Science.gov (United States)

    Strehle, Dan; Mollenkopf, Paul; Glaser, Martin; Golde, Tom; Schuldt, Carsten; Käs, Josef A; Schnauß, Jörg

    2017-10-24

    Bundled actin structures play an essential role in the mechanical response of the actin cytoskeleton in eukaryotic cells. Although responsible for crucial cellular processes, they are rarely investigated in comparison to single filaments and isotropic networks. Presenting a highly anisotropic structure, the determination of the mechanical properties of individual bundles was previously achieved through passive approaches observing bending deformations induced by thermal fluctuations. We present a new method to determine the bending stiffness of individual bundles, by measuring the decay of an actively induced oscillation. This approach allows us to systematically test anisotropic, bundled structures. Our experiments revealed that thin, depletion force-induced bundles behave as semiflexible polymers and obey the theoretical predictions determined by the wormlike chain model. Thickening an individual bundle by merging it with other bundles enabled us to study effects that are solely based on the number of involved filaments. These thicker bundles showed a frequency-dependent bending stiffness, a behavior that is inconsistent with the predictions of the wormlike chain model. We attribute this effect to internal processes and give a possible explanation with regard to the wormlike bundle theory.

  17. Single Actin Bundle Rheology

    Directory of Open Access Journals (Sweden)

    Dan Strehle

    2017-10-01

    Full Text Available Bundled actin structures play an essential role in the mechanical response of the actin cytoskeleton in eukaryotic cells. Although responsible for crucial cellular processes, they are rarely investigated in comparison to single filaments and isotropic networks. Presenting a highly anisotropic structure, the determination of the mechanical properties of individual bundles was previously achieved through passive approaches observing bending deformations induced by thermal fluctuations. We present a new method to determine the bending stiffness of individual bundles, by measuring the decay of an actively induced oscillation. This approach allows us to systematically test anisotropic, bundled structures. Our experiments revealed that thin, depletion force-induced bundles behave as semiflexible polymers and obey the theoretical predictions determined by the wormlike chain model. Thickening an individual bundle by merging it with other bundles enabled us to study effects that are solely based on the number of involved filaments. These thicker bundles showed a frequency-dependent bending stiffness, a behavior that is inconsistent with the predictions of the wormlike chain model. We attribute this effect to internal processes and give a possible explanation with regard to the wormlike bundle theory.

  18. Cytoskeletal bundle mechanics

    NARCIS (Netherlands)

    Bathe, Mark; Heussinger, Claus; Claessens, Mireille Maria Anna Elisabeth; Bausch, Andreas R.; Frey, Erwin

    2008-01-01

    The mechanical properties of cytoskeletal actin bundles play an essential role in numerous physiological processes, including hearing, fertilization, cell migration, and growth. Cells employ a multitude of actin-binding proteins to actively regulate bundle dimensions and cross-linking properties to

  19. An overview of IPPE research on liquid metal fast reactor thermohydraulics

    Energy Technology Data Exchange (ETDEWEB)

    Sorokin, A. P.; Efanov, A. D.; Zhukov, A. V.; Bogoslovskaia, G. P. [SSC RF-IPPE, Kaluga (Russian Federation)

    2003-07-01

    The paper presents brief information on the most significant researches in the fields of liquid metal hydrodynamics and heat transfer performed in the State Scientific Center of Russian Federation 'Institute for Physics and Power Engineering' named after A.I.Leypunski applied to sodium-cooled fast reactors. Experimental methods for studying liquid metal thermohydraulics and applied measurement techniques are overviewed briefly in the paper. Some results of fundamental thermohydraulic investigations, such as quasi-universal character of velocity and temperature profile in liquid metals, if considered normally to the channel wall etc. are presented. Specific features of heat transfer in liquid metal cooled fuel subassembly are mentioned, among them there are: high level of coolant temperature; significant influence of an interchannel exchange on velocity and temperature distribution; an availability of contact thermal resistance; large azimuthal non-uniformity of velocity and temperature; 'conjugate' problem of heat transfer in combined geometry of fuel pin; an absence of stabilization of heat transfer in non-standard channels; an influence of non-uniform heat generation. Special attention is given to the temperature fields in fuel subassembly subjected to deformation because of radioactive swelling and creeping, as well as in case of blockage of a part of subassembly cross section. Some results of thermohydraulic investigation are demonstrated for intermediate heat exchangers, pressurized head collectors. Also the developed methods and codes of thermohydraulic calculations applied to fast reactor core are considered: subchannel approach, porous body model.

  20. The ABCDEF Implementation Bundle

    Directory of Open Access Journals (Sweden)

    Annachiara Marra

    2016-08-01

    Full Text Available Long-term morbidity, long-term cognitive impairment and hospitalization-associated disability are common occurrence in the survivors of critical illness, with significant consequences for patients and for the caregivers. The ABCDEF bundle represents an evidence-based guide for clinicians to approach the organizational changes needed for optimizing ICU patient recovery and outcomes. The ABCDEF bundle includes: Assess, Prevent, and Manage Pain, Both Spontaneous Awakening Trials (SAT and Spontaneous Breathing Trials (SBT, Choice of analgesia and sedation, Delirium: Assess, Prevent, and Manage, Early mobility and Exercise, and Family engagement. The purpose of this review is to describe the core features of the ABCDEF bundle.

  1. Bundle Branch Block

    Science.gov (United States)

    ... 2015. Bundle branch block Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  2. Thermodynamics of fiber bundles

    OpenAIRE

    Pride, Steven R.; Toussaint, Renaud

    2002-01-01

    A recent theory that determines the properties of disordered solids as the solid accumulates damage is applied to the special case of fiber bundles with global load sharing and is shown to be exact in this case. The theory postulates that the probability of observing a given emergent damage state is obtained by maximizing the emergent entropy as defined by Shannon subject to energetic constraints. This theory yields the known exact results for the fiber-bundle model with global load sharing a...

  3. Numerical modeling of secondary side thermohydraulics of horizontal steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Melikhov, V.I.; Melikhov, O.I.; Nigmatulin, B.I. [Research and Engineering Centre of LWR Nuclear Plants Safety, Moscow (Russian Federation)

    1995-12-31

    A mathematical model for the transient three-dimensional secondary side thermal hydraulics of the horizontal steam generator has been developed. The calculations of the steam generator PGV-1000 and PGV-4 nominal regimes and comparison of numerical and experimental results have been carried out. 7 refs.

  4. Influence of the outlet air temperature on the thermohydraulic behaviour of air coolers

    Directory of Open Access Journals (Sweden)

    Đorđević Emila M.

    2003-01-01

    Full Text Available The determination of the optimal process conditions for the operation of air coolers demands a detailed analysis of their thermohydraulic behaviour on the one hand, and the estimation of the operating costs, on the other. One of the main parameters of the thermohydraulic behaviour of this type of equipment, is the outlet air temperature. The influence of the outlet air temperature on the performance of air coolers (heat transfer coefficient overall heat transfer coefficient, required surface area for heat transfer air-side pressure drop, fan power consumption and sound pressure level was investigated in this study. All the computations, using AirCooler software [1], were applied to cooling of the process fluid and the condensation of a multicomponent vapour mixture on two industrial devices of known geometries.

  5. Development and preliminary validation of a steam generator 3D thermohydraulics analysis code STAF

    Energy Technology Data Exchange (ETDEWEB)

    Cong, Tenglong [School of Nuclear Science and Technology, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Department of Engineering Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706 (United States); Zhang, Rui; Tian, Wenxi; Qiu, Suizheng [School of Nuclear Science and Technology, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Su, G.H., E-mail: ghsu@mail.xjtu.edu.cn [School of Nuclear Science and Technology, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049 (China)

    2016-03-15

    Highlights: • A steam generator thermohydraulics analysis code STAF is developed based on FLUENT. • Heat transfer from primary to secondary side is calculated during iteration in STAF. • Localized flow characteristics in steam generator can be obtained by STAF. • STAF is validated by simulating the AP 1000 steam generator. • STAF is validated by FRIGG test. - Abstract: Porous media model in Fluent code, coupled with two-phase mixture flow model, resistance model of tubes and heat transfer model through tubes, is employed to develop a steam generator thermohydraulics analysis code STAF (Steam generator Thermohydraulics Analysis code based on Fluent). In this code, the heat transfer from primary to secondary side is calculated three-dimensionally during iteration. The localized velocity, temperature, enthalpy, quality and void fraction in steam generator can be obtained by this code. STAF is validated in two ways. First, STAF is used to calculate the thermal-hydraulic parameters in steam generator of AP 1000. The calculated results are compared with designed values to prove that the coupled heat transfer calculation in STAF is accurate. Second, STAF is employed to simulate the FRIGG test to validate the localized parameter calculation performance by comparing the calculated localized void fraction with test values.

  6. RBMK thermohydraulic safety assessments using RELAP5/MOD3 codes

    Energy Technology Data Exchange (ETDEWEB)

    Tsiklauri, G.V.; Schmitt, B.E.

    1995-06-01

    The capability of the RELAP5/MOD3 code to validate various transients encountered in RBMK reactor postulated accidents has been assessed. The assessment results include a loss of coolant accident at the inlet of the core pressure tube, the blockage of a pressure tube, and the pressure response of the core cavity to in core pressure tube ruptures. These assessments show that the RELAP5/MOD3 code can predict major phenomena during postulated accidents in the RBMK reactors.

  7. Right bundle branch block

    DEFF Research Database (Denmark)

    Bussink, Barbara E; Holst, Anders Gaarsdal; Jespersen, Lasse

    2013-01-01

    AimsTo determine the prevalence, predictors of newly acquired, and the prognostic value of right bundle branch block (RBBB) and incomplete RBBB (IRBBB) on a resting 12-lead electrocardiogram in men and women from the general population.Methods and resultsWe followed 18 441 participants included.......5%/2.3% in women, P Right bundle branch block was associated with significantly...... increased all-cause and cardiovascular mortality in both genders with age-adjusted hazard ratios (HR) of 1.31 [95% confidence interval (CI), 1.11-1.54] and 1.87 (95% CI, 1.48-2.36) in the gender pooled analysis with little attenuation after multiple adjustment. Right bundle branch block was associated...

  8. Bundles of Banach algebras

    Directory of Open Access Journals (Sweden)

    J. W. Kitchen

    1994-01-01

    Full Text Available We study bundles of Banach algebras π:A→X, where each fiber Ax=π−1({x} is a Banach algebra and X is a compact Hausdorff space. In the case where all fibers are commutative, we investigate how the Gelfand representation of the section space algebra Γ(π relates to the Gelfand representation of the fibers. In the general case, we investigate how adjoining an identity to the bundle π:A→X relates to the standard adjunction of identities to the fibers.

  9. Buying bundles: the effects of bundle attributes on the value of bundling

    OpenAIRE

    Linthorst, M.M.; Telgen, Jan; Schotanus, Fredo

    2008-01-01

    We consider the situation in which a buyer has to find the optimal degree of bundling for buying goods and services. From a review of the literature we develop attributes associated with bundling. Each of these attributes has an effect on the value of a bundle. Combined, the attributes determine the value of a bundle. We describe how the various attributes of a bundle contribute to the value of a bundle given the context of the buying situation. Based on interviews, a further analysis of bund...

  10. Buying bundles: the effects of bundling attributes on the value of bundling

    OpenAIRE

    Linthorst, M.M.; Telgen, Jan; Schotanus, Fredo

    2008-01-01

    We consider the situation in which a buyer has to find the optimal degree of bundling for buying goods and services. From a review of the literature we develop attributes associated with bundling. Each of these attributes has an effect on the value of a bundle. Combined, the attributes determine the value of a bundle. We describe how the various attributes of a bundle contribute to the value of a bundle given the context of the buying situation. Based on interviews, a further analysis of bund...

  11. Analysis of Subchannel and Rod Bundle PSBT Experiments with CATHARE 3

    Directory of Open Access Journals (Sweden)

    M. Valette

    2012-01-01

    Full Text Available This paper presents the assessment of CATHARE 3 against PWR subchannel and rod bundle tests of the PSBT benchmark. Noticeable measurements were the following: void fraction in single subchannel and rod bundle, multiple liquid temperatures at subchannel exit in rod bundle, and DNB power and location in rod bundle. All these results were obtained both in steady and transient conditions. Void fraction values are satisfactory predicted by CATHARE 3 in single subchannels with the pipe module. More dispersed predictions of void values are obtained in rod bundles with the CATHARE 3 3D module at subchannel scale. Single-phase liquid mixing tests and DNB tests in rod bundle are also analyzed. After calibrating the mixing in liquid single phase with specific tests, DNB tests using void mixing give mitigated results, perhaps linked to inappropriate use of CHF lookup tables in such rod bundles with many spacers.

  12. ALUMINUM BOX BUNDLING PRESS

    Directory of Open Access Journals (Sweden)

    Iosif DUMITRESCU

    2015-05-01

    Full Text Available In municipal solid waste, aluminum is the main nonferrous metal, approximately 80- 85% of the total nonferrous metals. The income per ton gained from aluminum recuperation is 20 times higher than from glass, steel boxes or paper recuperation. The object of this paper is the design of a 300 kN press for aluminum box bundling.

  13. Dynamics of flagellar bundling

    Science.gov (United States)

    Janssen, Pieter; Graham, Michael

    2010-11-01

    Flagella are long thin appendages of microscopic organisms used for propulsion in low-Reynolds environments. For E. coli the flagella are driven by a molecular motor, which rotates the flagella in a counter-clockwise motion (CCM). When in a forward swimming motion, all flagella bundle up. If a motor reverses rotation direction, the flagella unbundle and the cell makes a tumbling motion. When all motors turn in the same CC direction again, the flagella bundle up, and forward swimming continues. To investigate the bundling, we consider two flexible helices next to each other, as well as several flagella attached to a spherical body. Each helix is modeled as several prolate spheroids connected at the tips by springs. For hydrodynamic interactions, we consider the flagella to made up of point forces, while the finite size of the body is incorporated via Fax'en's laws. We show that synchronization occurs quickly relative to the bundling process. For flagella next to each other, the initial deflection is generated by rotlet interactions generated by the rotating helices. At longer times, simulations show the flagella only wrap once around each other, but only for flagella that are closer than about 4 helix radii. Finally, we show a run-and-tumble motion of the body with attached flagella.

  14. Nuclear reactors transients identification and classification system; Sistema de identificacao e classificacao de transientes em reatores nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, Paulo Henrique

    2008-07-01

    This work describes the study and test of a system capable to identify and classify transients in thermo-hydraulic systems, using a neural network technique of the self-organizing maps (SOM) type, with the objective of implanting it on the new generations of nuclear reactors. The technique developed in this work consists on the use of multiple networks to do the classification and identification of the transient states, being each network a specialist at one respective transient of the system, that compete with each other using the quantization error, that is a measure given by this type of neural network. This technique showed very promising characteristics that allow the development of new functionalities in future projects. One of these characteristics consists on the potential of each network, besides responding what transient is in course, could give additional information about that transient. (author)

  15. Bundle pricing with comparable items

    NARCIS (Netherlands)

    Grigoriev, Alexander; van Loon, Joyce; Sviridenko, Maxim; Uetz, Marc Jochen; Vredeveld, Tjark; Arge, L.; Hoffmann, M.; Welzl, E.

    2007-01-01

    We consider a revenue maximization problem where we are selling a set of items, each available in a certain quantity, to a set of bidders. Each bidder is interested in one or several bundles of items. We assume the bidders’ valuations for each of these bundles to be known. Whenever bundle prices are

  16. Bundling ecosystem services in Denmark

    DEFF Research Database (Denmark)

    Turner, Katrine Grace; Odgaard, Mette Vestergaard; Bøcher, Peder Klith

    2014-01-01

    to form synergies. We identified six distinct ecosystem service bundle types, indicating multiple interactions at a landscape level. The bundle types showed specialized areas of agricultural production, high provision of cultural services at the coasts, multifunctional mixed-use bundle types around urban...

  17. Development of an extended thermo-hydraulic simulation tool for fusion magnet design study - Application to the initial versions of JT-60SA TF coils layout

    Science.gov (United States)

    Nicollet, S.; Lacroix, B.; Zani, L.; Hertout, P.; Portafaix, Ch.; Villari, R.

    2010-01-01

    In the framework of the EU participation to JT-60SA project [1], a dedicated simulation tool named after Thermo-hydraulic EXtended Tool (TEXTO) was developed at CEA between 2006 and 2007 in order to address in a reliable way the calculation of the magnet conductor temperature increase and temperature margins in different operating conditions. The simulation process is based on three different codes, addressing each specific aspects (MCNP for the 3D nuclear heat calculation, TRAPS for magnetic field, ANSYS for 2D transverse thermal contribution of coil casing), which finally stand as input for the well established code GANDALF (with transient helium properties). Both steady-state operating and disruption transient regimes can be studied with this process and a first application is performed on the basis of the design and operating conditions available at this time on JT-60SA TF magnets, i.e. the first version of the different design stages. The complete analysis is shown together with the associated proposals for the TF conductor layout that could be derived from these studies.

  18. Buying bundles: the effects of bundling attributes on the value of bundling

    NARCIS (Netherlands)

    Linthorst, M.M.; Telgen, Jan; Schotanus, Fredo

    2008-01-01

    We consider the situation in which a buyer has to find the optimal degree of bundling for buying goods and services. From a review of the literature we develop attributes associated with bundling. Each of these attributes has an effect on the value of a bundle. Combined, the attributes determine the

  19. Buying bundles: the effects of bundle attributes on the value of bundling

    NARCIS (Netherlands)

    Linthorst, M.M.; Telgen, Jan; Schotanus, Fredo

    2008-01-01

    We consider the situation in which a buyer has to find the optimal degree of bundling for buying goods and services. From a review of the literature we develop attributes associated with bundling. Each of these attributes has an effect on the value of a bundle. Combined, the attributes determine the

  20. Helices and vector bundles

    CERN Document Server

    Rudakov, A N

    1990-01-01

    This volume is devoted to the use of helices as a method for studying exceptional vector bundles, an important and natural concept in algebraic geometry. The work arises out of a series of seminars organised in Moscow by A. N. Rudakov. The first article sets up the general machinery, and later ones explore its use in various contexts. As to be expected, the approach is concrete; the theory is considered for quadrics, ruled surfaces, K3 surfaces and P3(C).

  1. Bundling harvester; Nippukorjausharvesteri

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, K. [Eko-Log Oy, Kuopio (Finland)

    1996-12-31

    The staring point of the project was to design and construct, by taking the silvicultural point of view into account, a harvesting and processing system especially for energy-wood, containing manually driven bundling harvester, automatizing of the harvester, and automatized loading. The equipment forms an ideal method for entrepreneur`s-line harvesting. The target is to apply the system also for owner`s-line harvesting. The profitability of the system promotes the utilization of the system in both cases. The objectives of the project were: to construct a test equipment and prototypes for all the project stages, to carry out terrain and strain tests in order to examine the usability and durability, as well as the capacity of the machine, to test the applicability of the Eko-Log system in simultaneous harvesting of energy and pulp woods, and to start the marketing and manufacturing of the products. The basic problems of the construction of the bundling harvester have been solved using terrain-tests. The prototype machine has been shown to be operable. Loading of the bundles to form sufficiently economically transportable loads has been studied, and simultaneously, the branch-biomass has been tried to be utilized without loosing the profitability of transportation. The results have been promising, and will promote the profitable utilization of wood-energy

  2. A Thermo-Hydraulic Tool for Automatic Virtual Hazop Evaluation

    Directory of Open Access Journals (Sweden)

    Pugi L.

    2014-12-01

    Full Text Available Development of complex lubrication systems in the Oil&Gas industry has reached high levels of competitiveness in terms of requested performances and reliability. In particular, the use of HazOp (acronym of Hazard and Operability analysis represents a decisive factor to evaluate safety and reliability of plants. The HazOp analysis is a structured and systematic examination of a planned or existing operation in order to identify and evaluate problems that may represent risks to personnel or equipment. In particular, P&ID schemes (acronym of Piping and Instrument Diagram according to regulation in force ISO 14617 are used to evaluate the design of the plant in order to increase its safety and reliability in different operating conditions. The use of a simulation tool can drastically increase speed, efficiency and reliability of the design process. In this work, a tool, called TTH lib (acronym of Transient Thermal Hydraulic Library for the 1-D simulation of thermal hydraulic plants is presented. The proposed tool is applied to the analysis of safety relevant components of compressor and pumping units, such as lubrication circuits. Opposed to the known commercial products, TTH lib has been customized in order to ease simulation of complex interactions with digital logic components and plant controllers including their sensors and measurement systems. In particular, the proposed tool is optimized for fixed step execution and fast prototyping of Real Time code both for testing and production purposes. TTH lib can be used as a standard SimScape-Simulink library of components optimized and specifically designed in accordance with the P&ID definitions. Finally, an automatic code generation procedure has been developed, so TTH simulation models can be directly assembled from the P&ID schemes and technical documentation including detailed informations of sensor and measurement system.

  3. Bundled payments in orthopedic surgery.

    Science.gov (United States)

    Bushnell, Brandon D

    2015-02-01

    As a result of reading this article, physicians should be able to: 1. Describe the concept of bundled payments and the potential applications of bundled payments in orthopedic surgery. 2. For specific situations, outline a clinical episode of care, determine the participants in a bundling situation, and define care protocols and pathways. 3. Recognize the importance of resource utilization management, quality outcome measurement, and combined economic-clinical value in determining the value of bundled payment arrangements. 4. Identify the implications of bundled payments for practicing orthopedists, as well as the legal issues and potential future directions of this increasingly popular alternative payment method. Bundled payments, the idea of paying a single price for a bundle of goods and services, is a financial concept familiar to most American consumers because examples appear in many industries. The idea of bundled payments has recently gained significant momentum as a financial model with the potential to decrease the significant current costs of health care. Orthopedic surgery as a field of medicine is uniquely positioned for success in an environment of bundled payments. This article reviews the history, logistics, and implications of the bundled payment model relative to orthopedic surgery. Copyright 2015, SLACK Incorporated.

  4. Neutronics and thermo-hydraulic design of supercritical-water cooled solid breeder TBM

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jie; Wu, Yingwei, E-mail: wyw810@mail.xjtu.edu.cn; Tian, Wenxi; Su, Guanghui; Qiu, Suizheng

    2015-03-15

    Highlights: • A supercritical-water cooled solid breeder test blanket module (SWCB TBM) was designed. • The neutronics calculations show that the tritium breeding ratio (TBR) of SWCB TBM is 1.17. • The outlet temperature of SWCB TBM can reach as high as 500 °C. • Both thermal stress and deformation of the SWCB TBM design are within safety limits. - Abstract: In this paper, the supercritical-water cooled solid breeder test blanket module (SWCB TBM), using the supercritical water as the coolant, Li{sub 4}SiO{sub 4} lithium ceramic pebbles as a breeder, and beryllium pebbles as a neutron multiplier, was designed and analyzed for ITER. The results of neutronics, thermo-hydraulic and thermo-mechanical analysis are presented for the SWCB TBM. Neutronics calculations show that the proposed TBM has high tritium breeding ratio and power density. The tritium breeding ratio (TBR) of the proposed design is 1.17, which is greater than that of 1.15 required for tritium self-sufficiency. The thermo-hydraulic calculation proved that the TBM components can be effectively cooled to the allowable temperature with the temperature of outlet reaching 500 °C. According to thermo-mechanics calculation results, the first wall with the width of 17 mm is safe and the deformation of first wall is far below the limited value. All the results showed that the current TBM design was reasonable under the ITER normal condition.

  5. Effect of Parametric Uncertainties, Variations, and Tolerances on Thermohydraulic Performance of Flat Plate Solar Air Heater

    Directory of Open Access Journals (Sweden)

    Rajendra Karwa

    2014-01-01

    Full Text Available The paper presents results of an analysis carried out using a mathematical model to find the effect of the uncertainties, variations, and tolerances in design and ambient parameters on the thermohydraulic performance of flat plate solar air heater. Analysis shows that, for the range of flow rates considered, a duct height of 10 mm is preferred from the thermohydraulic consideration. The thermal efficiency changes by about 2.6% on variation in the wind heat transfer coefficient, ±5 K variation in sky temperature affects the efficiency by about ±1.3%, and solar insolation variation from 500 to 1000 Wm−2 affects the efficiency by about −1.5 to 1.3% at the lowest flow rate of 0.01 kgs−1 m−2 of the absorber plate with black paint. In general, these effects reduce with increase in flow rate and are lower for collector with selective coating on the absorber plate surface. The tolerances in the duct height and absorber plate emissivity should be small while positive tolerance of 3° in the collector slope for winter operation and ±3° for year round operation, and a positive tolerance for the gap between the absorber plate and glass cover at nominal value of 40 mm are recommended.

  6. Validation and verification of the MTR{sub P}C thermohydraulic package

    Energy Technology Data Exchange (ETDEWEB)

    Doval, Alicia [INVAP S.E., Bariloche, Rio Negro (Argentina). Nuclear Engineering Dept.]. E-mail: doval@invap.com.ar

    1998-07-01

    The MTR{sub P}C v2.6 is a computational package developed for research reactor design and calculation. It covers three of the main aspects of a research reactor: neutronic, shielding and thermohydraulic. In this work only the thermohydraulic package will be covered, dealing with verification and validation aspects. The package consists of the following steady state programs: CAUDVAP 2.60 for the hydraulic calculus, estimates the velocity distribution through different parallel channels connected to a common inlet and outlet common plenum. TERMIC 1H v3.0, used for the thermal design of research reactors, provides information about heat flux for a given maximum wall temperature, onset of nucleate boiling, redistribution phenomena and departure from nucleate boiling. CONVEC V3.0 allows natural convection calculations, giving information on heat fluxes for onset of nucleate boiling, pulsed and burn-out phenomena as well as total coolant flow. Results have been validated against experimental values and verified against theoretical and computational programmes results, showing a good agreement. (author)

  7. Heat flux: thermohydraulic investigation of solar air heaters used in agro-industrial applications

    Science.gov (United States)

    Rahmati Aidinlou, H.; Nikbakht, A. M.

    2017-03-01

    A new design of solar air heater simulator is presented to comply with the extensive applications inagro-industry. A wise installation of increased heat transfer surface area provided uniform and efficient heat diffusion over the duct. Nusselt number and friction factor have been investigated based on the constant roughness parameters such as relative roughness height (e/D), relative roughness pitch (P/e), angle of attack (α) and aspect ratio with Reynolds numbers ranging from 5000 to 19,000 in the fully developed region. Heat fluxes of 800, 900 and 1000 Wm-2 were provided. The enhancement in friction factor is observed to be 3.1656, 3.47 and 3.0856 times, and for the Nusselt number either, augmentation is calculated to be 1.4437, 1.4963 and 1.535 times, respectively, over the smooth duct for 800, 900 and 1000 Wm-2 heat fluxes. Thermohydraulic performance is plotted versus the Reynolds number based on the aforementioned roughness parameters at varying heat fluxes. The results show up that thermohydraulic performance is found to be maximum for 1000 Wm-2 at the average Reynolds number of 5151. Based on the results, we can verify that the introduced solar simulator can help analyzing and developing solar collector installations at the simulated heat fluxes.

  8. A novel thermo-hydraulic coupling model to investigate the crater formation in electrical discharge machining

    Science.gov (United States)

    Tang, Jiajing; Yang, Xiaodong

    2017-09-01

    A novel thermo-hydraulic coupling model was proposed in this study to investigate the crater formation in electrical discharge machining (EDM). The temperature distribution of workpiece materials was included, and the crater formation process was explained from the perspective of hydrodynamic characteristics of the molten region. To better track the morphology of the crater and the movement of debris, the level-set method was introduced in this study. Simulation results showed that the crater appears shortly after the ignition of the discharge, and the molten material is removed by vaporizing in the initial stage, then by splashing at the following time. The driving force for the detachment of debris in the splashing removal stage comes from the extremely large pressure difference in the upper part of the molten region, and the morphology of the crater is also influenced by the shearing flow of molten material. It was found that the removal ratio of molten material is only about 7.63% under the studied conditions, leaving most to form the re-solidification layer on the surface of the crater. The size of the crater reaches the maximum at the end of discharge duration then experiences a slight reduction because of the reflux of molten material after the discharge. The results of single pulse discharge experiments showed that the morphologies and sizes between the simulation crater and actual crater are good at agreement, verifying the feasibility of the proposed thermo-hydraulic coupling model in explaining the mechanisms of crater formation in EDM.

  9. Muon bundles from the Universe

    Directory of Open Access Journals (Sweden)

    Kankiewicz P.

    2018-01-01

    Full Text Available Recently the CERN ALICE experiment, in its dedicated cosmic ray run, observed muon bundles of very high multiplicities, thereby confirming similar findings from the LEP era at CERN (in the CosmoLEP project. Significant evidence for anisotropy of arrival directions of the observed high multiplicity muonic bundles is found. Estimated directionality suggests their possible extragalactic provenance. We argue that muonic bundles of highest multiplicity are produced by strangelets, hypothetical stable lumps of strange quark matter infiltrating our Universe.

  10. Modelling of fuel bundle deformation at high temperatures: requirements, models and steps for consideration

    Energy Technology Data Exchange (ETDEWEB)

    Xu, S.; Xu, Z.; Fan, H.; Nitheanandan, T. [Atomic Energy of Canada Limited, MIssissauga, Ontario (Canada)

    2010-07-01

    To model thermal mechanical bundle deformation behaviour under high temperature conditions, several factors need to be considered. These are the sources of loads, deformation mechanisms, interactions within bundle components, bundle and pressure tube (PT) interaction, and boundary constraints on the fuel bundles under in-reactor conditions. This paper describes the modelling of the following three processes: Bundle slumping due to high temperature creep-sag of individual elements and endplates; Differential element expansion and fuel element bowing; and, Bundle distortion under axial loads. To model these processes, a number of key mechanisms for bundle deformation must be considered, which include: 1) Interaction of fuel elements in a bundle with their neighbours, 2) Endplate deformation, 3) Fuel elements lateral deformation under various loads and mechanisms, 4) Interaction within a fuel element, 5) Material property change at high temperatures, 6) Transient response of a bundle, and 7) Bundle configuration change. This paper summarises the new models needed for the mechanistic modelling of the key mechanisms mentioned above and provides an example to show how an endplate plasticity model is developed with results. (author)

  11. Bundle Formation in Biomimetic Hydrogels

    NARCIS (Netherlands)

    Jaspers, Maarten; Pape, A C H; Voets, Ilja K; Rowan, Alan E; Portale, Giuseppe; Kouwer, Paul H J

    2016-01-01

    Bundling of single polymer chains is a crucial process in the formation of biopolymer network gels that make up the extracellular matrix and the cytoskeleton. This bundled architecture leads to gels with distinctive properties, including a large-pore-size gel formation at very low concentrations and

  12. Bundle Security Protocol for ION

    Science.gov (United States)

    Burleigh, Scott C.; Birrane, Edward J.; Krupiarz, Christopher

    2011-01-01

    This software implements bundle authentication, conforming to the Delay-Tolerant Networking (DTN) Internet Draft on Bundle Security Protocol (BSP), for the Interplanetary Overlay Network (ION) implementation of DTN. This is the only implementation of BSP that is integrated with ION.

  13. Recommendations; Rekommendationer foer analys av spaenningsrespons i roersystem utsatta foer termohydrauliska transienter

    Energy Technology Data Exchange (ETDEWEB)

    Bjoerndahl, Olof; Letzter, Adam; Marcinkiewicz, Jerzy; Segle, Peter (Inspecta Nuclear AB, 104 25 Stockholm (Sweden))

    2007-03-15

    Transient thermohydraulic events often control the design of piping systems in nuclear power plants. Water hammers due to valve closure, pressure transients caused by steam collapse and pipe break all result in structural loads that are characterised by a high frequency content. What also characterises these pressures/forces is the specific spatial and time dependence that is acting on the piping system and found in the wave propagation in the contained fluid. The aim with this project has been to develop recommendations for analysis of the stress response in piping systems subjected to thermohydraulic transients. Basis for this work is that the so called two-step-method is applied and that the structural response is calculated with modal superposition. Derived analysis criteria are based on the assumption that the associated volume strain energy in the wave propagation for the contained fluid may be well defined by a parameter, here called epsilon{sub PN}. The stress response in the piping system is assumed to be completely determined with certain accuracy for that part of the volume strain energy in the wave propagation associated with this parameter. A comprehensive work has been done to determine the accuracy in loadings calculated with RELAP5. Properties such as period elongation and associated spurious oscillations in the pressure wave transient have been investigated. Furthermore, has the characteristics of the artificial numerical damping in RELAP5 been identified. Based on desired accuracy of the thermohydraulic analysis together with knowledge about the duration of the thermohydraulic perturbation, the lowest upper frequency limit f{sub Pipe}, in the modal base that is required for the structure model is calculated. With perturbation is meant such as a valve closure. According to suggested criteria and with the upper frequency limit set, the essential parameters i) largest size of the elements in the structure model and ii) the largest applicable time

  14. Fission product release assessment for end fitting failure in Candu reactor loaded with CANFLEX-NU fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Dirk Joo; Jeong, Chang Joon; Lee, Kang Moon; Suk, Ho Chun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    Fission product release (FPR) assessment for End Fitting Failure (EFF) in CANDU reactor loaded with CANFLEX-natural uranium (NU) fuel bundles has been performed. The predicted results are compared with those for the reactor loaded with standard 37-element bundles. The total channel I-131 release at the end of transient for EFF accident is calculated to be 380.8 TBq and 602.9 TBq for the CANFLEX bundle and standard bundle channel cases, respectively. They are 4.9% and 7.9% of total inventory, respectively. The lower total releases of the CANFLEX bundle O6 channel are attributed to the lower initial fuel temperatures caused by the lower linear element power of the CANFLEX bundle compared with the standard bundle. 4 refs., 1 fig., 4 tabs. (Author)

  15. Fiber bundle phase conjugate mirror

    Science.gov (United States)

    Ward, Benjamin G.

    2012-05-01

    An improved method and apparatus for passively conjugating the phases of a distorted wavefronts resulting from optical phase mismatch between elements of a fiber laser array are disclosed. A method for passively conjugating a distorted wavefront comprises the steps of: multiplexing a plurality of probe fibers and a bundle pump fiber in a fiber bundle array; passing the multiplexed output from the fiber bundle array through a collimating lens and into one portion of a non-linear medium; passing the output from a pump collection fiber through a focusing lens and into another portion of the non-linear medium so that the output from the pump collection fiber mixes with the multiplexed output from the fiber bundle; adjusting one or more degrees of freedom of one or more of the fiber bundle array, the collimating lens, the focusing lens, the non-linear medium, or the pump collection fiber to produce a standing wave in the non-linear medium.

  16. Transient reflectivity on vertically aligned single-wall carbon nanotubes

    NARCIS (Netherlands)

    Galimberti, Gianluca; Ponzoni, Stefano; Ferrini, Gabriele; Hofmann, Stephan; Arshad, Muhammad; Cepek, Cinzia; Pagliara, Stefania

    2013-01-01

    One-color transient reflectivity measurements are carried out on two different samples of vertically aligned single-wall carbon nanotube bundles and compared with the response recently published on unaligned bundles. The negative sign of the optical response for both samples indicates that the free

  17. Design, construction and evaluation of solar flat-plate collector simulator based on the thermohydraulic coefficient

    Directory of Open Access Journals (Sweden)

    H Rahmati Aidinlou

    2017-05-01

    Full Text Available Introduction Increasing the area of absorber plate between the flowed air through the duct can be accomplished by corrugating the absorber plate or by using the artificial roughness underside of the absorber plate as the commercial methods for enhancing the thermohydraulic performance of the flat plate solar air heaters. Evaluation of this requires the construction of separated solar air heater which is costly and time consuming. The constructed solar flat-plate collector simulator can be a sufficient solution for obtaining the heat transfer and thermodynamic parameters for evaluating the absorber plate. The inclined broken roughness was chosen as the optimum roughness which is surrounded by three aluminum smooth walls. Materials and Methods The duct for both smooth and roughened plate have been constructed based on the ASHRAE 93-2010 standard. In order to achieve a fully thermal and hydraulic developed flow, the plenum is constructed. The centrifugal fan is considered by applying the required air volume at the pressure drop obtained by the duct, plenum and the orifice meter. The TSI velocity-meter 8355 is used to measure the velocity of air crossing through the pipe connected to the centrifugal fan. The micro manometer Kimo CPE310-s with the resolution of 0.1 Pa is used to measure the pressure drop across the test section of the smooth and roughened duct. The LM35 sensors are used to measure the absorber plate and air temperature through the test section. Obtained parameters are used to calculate the Nusselt number and friction factor across the test section for smooth and roughened absorber plate. The Nusselt number and friction factor parameters which is obtained for smooth absorber plate based on experimental set-up, is compared with Dittus-Bolter and Blasius equations, respectively, for validating the simulator. By calculating the Nusselt number and friction factor, Stanton number is obtained based on the equation (6, and thermohydraulic

  18. Semiflexible Biopolymers in Bundled Arrangements

    Directory of Open Access Journals (Sweden)

    Jörg Schnauß

    2016-07-01

    Full Text Available Bundles and networks of semiflexible biopolymers are key elements in cells, lending them mechanical integrity while also enabling dynamic functions. Networks have been the subject of many studies, revealing a variety of fundamental characteristics often determined via bulk measurements. Although bundles are equally important in biological systems, they have garnered much less scientific attention since they have to be probed on the mesoscopic scale. Here, we review theoretical as well as experimental approaches, which mainly employ the naturally occurring biopolymer actin, to highlight the principles behind these structures on the single bundle level.

  19. MAVEN EUV Modelled Data Bundle

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains solar irradiance spectra in 1-nm bins from 0-190 nm. The spectra are generated based upon the Flare Irradiance Spectra Model - Mars (FISM-M)...

  20. Left bundle-branch block

    DEFF Research Database (Denmark)

    Risum, Niels; Strauss, David; Sogaard, Peter

    2013-01-01

    The relationship between myocardial electrical activation by electrocardiogram (ECG) and mechanical contraction by echocardiography in left bundle-branch block (LBBB) has never been clearly demonstrated. New strict criteria for LBBB based on a fundamental understanding of physiology have recently...

  1. MAVEN SWEA Calibrated Data Bundle

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains fully calibrated electron energy/angle (3D) distributions, pitch angle distributions, and omni-directional energy spectra. Tables of sensitivity...

  2. MAVEN LPW Derived Data Bundle

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains data which have been derived from other data products or determined by fits to other data. These are science quality data produced by the LPW...

  3. MAVEN LPW Calibrated Data Bundle

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains fully calibrated, science quality data produced by the LPW instrument. The data include spacecraft potential, electric field waveforms and wave...

  4. Optimum control parameters and long-term productivity of geothermal reservoirs using coupled thermo-hydraulic process modelling

    OpenAIRE

    Aliyu, Musa D.; Chen, Hua-Peng

    2017-01-01

    Knowing the long-term performance of geothermal energy extraction is crucial to decision-makers and reservoir engineers for optimal management and sustainable utilisation. This article presents a three dimensional, numerical model of coupled thermo-hydraulic processes, in a deep heterogeneous geothermal reservoir overlain and underlain by impermeable layers, with discrete fracture. The finite element method is employed in modelling the reservoir, after conducting a verification study to test ...

  5. Transient reflectivity on vertically aligned single-wall carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Galimberti, Gianluca; Ponzoni, Stefano; Ferrini, Gabriele [Interdisciplinary Laboratory for Advanced Materials Physics (i-LAMP) and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, I-25121 Brescia (Italy); Hofmann, Stephan [Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Arshad, Muhammad [Zernike Institute for Advanced Materials, University of Groningen (Netherlands); ICTP, Strada Costiera 11, I-34151 Trieste (Italy); National Centre for Physics Quaid-i-Azam University Islamabad (Pakistan); Cepek, Cinzia [Istituto Officina dei Materiali — CNR, Laboratorio TASC, Area Science Park, Basovizza, I-34149 Trieste (Italy); Pagliara, Stefania, E-mail: pagliara@dmf.unicatt.it [Interdisciplinary Laboratory for Advanced Materials Physics (i-LAMP) and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, I-25121 Brescia (Italy)

    2013-09-30

    One-color transient reflectivity measurements are carried out on two different samples of vertically aligned single-wall carbon nanotube bundles and compared with the response recently published on unaligned bundles. The negative sign of the optical response for both samples indicates that the free electron character revealed on unaligned bundles is only due to the intertube interactions favored by the tube bending. Neither the presence of bundles nor the existence of structural defects in aligned bundles is able to induce a free-electron like behavior of the photoexcited carriers. This result is also confirmed by the presence of non-linear excitonic effects in the transient response of the aligned bundles. - Highlights: • Transient reflectivity measurements on two aligned carbon nanotube samples • Relationship between unalignment and/or bundling and intertube interaction • The bundling is not able to modify the intertube interactions • The presence of structural defects does not affect the intertube interactions • A localized exciton-like behavior has been revealed in these samples.

  6. Thermohydraulic Design Analysis Modeling for Korea Advanced NUclear Thermal Engine Rocket for Space Application

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Seung Hyun; Choi, Jae Young; Venneria, Paolo F.; Jeong, Yong Hoon; Chang, Soon Heung [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    NTR engines have continued as a main stream based on the mature technology. The typical core design of the NERVA derived engines uses hexagonal shaped fuel elements with circular cooling channels and structural tie-tube elements for supporting the fuel elements, housing moderator and regeneratively cooling the moderator. The state-of-the-art NTR designs mostly use a fast or epithermal neutron spectrum core utilizing a HEU fuel to make a high power reactor with small and simple core geometry. Nuclear propulsion is the most promising and viable option to achieve challenging deep space missions. Particularly, the attractions of a NTR include excellent thrust and propellant efficiency, bimodal capability, proven technology, and safe and reliable performance. The KANUTER-HEU and -LEU are the innovative and futuristic NTR engines to reduce the reactor size and to implement a LEU fuel in the reactor by using thermal neutron spectrum. The KANUTERs have some features in the reactor design such as the integrated fuel element and the regeneratively cooling channels to increase room for moderator and heat transfer in the core, and ensuing rocket performance. To study feasible design points in terms of thermo-hydraulics and to estimate rocket performance of the KANUTERs, the NSES is under development. The model of the NSES currently focuses on thermo-hydraulic analysis of the peculiar and complex EHTGR design during the propulsion mode in steady-state. The results indicate comparable performance for future applications, even though it uses the heavier LEU fuel. In future, the NSES will be modified to obtain temperature distribution of the entire reactor components and then more extensive design analysis of neutronics, thermohydraulics and their coupling will be conducted to validate design feasibility and to optimize the reactor design enhancing the rocket performance.

  7. Response of Compacted Bentonites to Thermal and Thermo-Hydraulic Loadings at High Temperatures

    Directory of Open Access Journals (Sweden)

    Snehasis Tripathy

    2017-07-01

    Full Text Available The final disposal of high-level nuclear waste in many countries is preferred to be in deep geological repositories. Compacted bentonites are proposed for use as the buffer surrounding the waste canisters which may be subjected to both thermal and hydraulic loadings. A significant increase in the temperature is anticipated within the buffer, particularly during the early phase of the repository lifetime. In this study, several non-isothermal and non-isothermal hydraulic tests were carried on compacted MX80 bentonite. Compacted bentonite specimens (water content = 15.2%, dry density = 1.65 Mg/m3 were subjected to a temperature of either 85 or 150 °C at one end, whereas the temperature at the opposite end was maintained at 25 °C. During the non-isothermal hydraulic tests, water was supplied from the opposite end of the heat source. The temperature and relative humidity were monitored along predetermined depths of the specimens. The profiles of water content, dry density, and degree of saturation were established after termination of the tests. The test results showed that thermal gradients caused redistribution of the water content, whereas thermo-hydraulic gradients caused both redistribution and an increase in the water content within compacted bentonites, both leading to development of axial stress of various magnitudes. The applied water injection pressures (5 and 600 kPa and temperature gradients appeared to have very minimal impact on the magnitude of axial stress developed. The thickness of thermal insulation layer surrounding the testing devices was found to influence the temperature and relative humidity profiles thereby impacting the redistribution of water content within compacted bentonites. Under the influence of both the applied thermal and thermo-hydraulic gradients, the dry density of the bentonite specimens increased near the heat source, whereas it decreased at the opposite end. The test results emphasized the influence of

  8. Changing axis deviation and intermittent right bundle branch block during acute myocardial infarction.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Sturiale, Mauro

    2011-03-03

    Dissimilar electrocardiographic patterns associated with right bundle branch block have been described. The prognosis of right bundle branch block in the absence of underlying cardiac disease is good but it may be poor in other cases, particularly coronary artery disease. Changing bundle branch block, new right bundle branch block, right bundle branch conduction disturbances have been reported in literature. Changing axis deviation has been reported alone or during acute myocardial infarction also associated with atrial fibrillation. Intermittent right axis deviation has been rarely reported in the presence of left bundle branch block also during atrial fibrillation and with acute myocardial infarction too. Isolated left posterior hemiblock is a very rare finding and transient right axis deviation associated with a left posterior hemiblock pattern has been also rarely described associated with acute myocardial infarction. We describe a case of changing axis deviation with intermittent right bundle branch block in a patient admitted with acute myocardial infarction. Also this case focuses attention on changing axis deviation and intermittent right bundle branch block during acute myocardial infarction. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  9. Right bundle branch block with revelation of changing axis deviation at the end of atrial fibrillation.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Sturiale, Mauro

    2009-11-12

    Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Left bundle branch block is usually associated with normal or left axis deviation. Rarely the ECG shows a left bundle branch block with changing QRS morphology and changing axis deviation. There are several possible explanations for the intermittent shift in the QRS axis in the presence of complete left bundle branch block. The most plausible explanation is the coexistence of left posterior hemiblock and predivisional left bundle branch block. Intermittent right axis deviation has been rarely reported in the presence of left bundle branch block also during atrial fibrillation and with acute myocardial infarction too. Isolated left posterior hemiblock is a very rare finding and transient right axis deviation associated with a left posterior hemiblock pattern has been also rarely described associated with acute myocardial infarction. Changing axis deviation with changing bundle branch block and new-onset of atrial fibrillation during acute myocardial infarction has been also reported. Changing axis deviation with intermittent right bundle branch block in a patient admitted with acute myocardial infarction has been also described. We present a case of a right bundle branch block with revelation of changing axis deviation at the end of atrial fibrillation in a 68-year-old Italian man.

  10. Thermohydraulic modeling of very high temperature reactors in regimes with loss of coolant using CFD

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Uebert G.; Dominguez, Dany S. [Universidade Estadual de Santa Cruz (UESC), Ilh´eus, BA (Brazil). Programa de P´os-Graduacao em Modelagem Computacional em Ciencia e Tecnologia; Mazaira, Leorlen Y.R.; Lira, Carlos A.B.O. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Hernandez, Carlos R.G., E-mail: uebert.gmoreira@gmail.com, E-mail: dsdominguez@gmail.com, E-mail: leored1984@gmail.com, E-mail: cabol@ufpe.br, E-mail: cgh@instec.cu [Instituto Superior de Tecnologas y Ciencias Aplicadas (InSTEC), La Habana (Cuba)

    2017-07-01

    The nuclear energy is a good alternative to meet the continuous increase in world energy demand. In this perspective, VHTRs (Very High Temperature Reactors) are serious candidates for energy generation due to its inherently safe performance, low power density and high conversion efficiency. However, the viability of these reactors depends on an efficient safety system in the operation of nuclear plants. The HTR (High Temperature Reactor)-10 model, an experimental reactor of the pebble bed type, is used as a case study in this work to perform the thermohydraulic simulation. Due to the complex patterns flow that appear in the pebble bed reactor core, and advances in computational capacity, CFD (Computational Fluid Dynamics) techniques are used to simulate these reactors. A realistic approach is adopted to simulate the central annular column of the reactor core, which each pebble bed element is modeled in detail. As geometrical model of the fuel elements was selected the BCC (Body Centered Cubic) arrangement. Previous works indicate this arrangement as the configuration that obtain higher fuel temperatures inside the core. Parameters considered for reactor design are available in the technical report of benchmark issues by IAEA (TECDOC-1694). Among the results obtained, we obtained the temperature profiles with different mass flow rates for the coolant. In general, the temperature distributions calculated are consistent with phenomenological behaviour. Even without consider the reactivity changes to reduce the reactor power or other safety procedures, the maximum temperatures do not exceed the recommended limits for fuel elements. (author)

  11. Thermohydraulic behavior of the liquid metal target of a spallation neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Y.

    1996-06-01

    The author presents work done on three main problems. (1) Natural circulation in double coaxial cylindircal container: The thermohydraulic behaviour of the liquid metal target of the spallation neutron source at PSI has been investigated. The configuration is a natural-circulation loop in a concentric double-tube-type container. The results show that the natural-circulation loop concept is valid for the design phase of the target construction, and the current specified design criteria will be fulfilled with the proposed parameter values. (2) Flow around the window: Water experiments were performed for geometry optimisation of the window shape of the SINQ container for avoiding generating recirculation zones at peripheral area and the optimal cooling of the central part of the beam entrance window. Flow visualisation technique was mainly used for various window shapes, gap distance between the window and the guide tube edge. (3) Flow in window cooling channels: Flows in narrow gaps of cooling channels of two different types of windows were studied by flow visualisation techniques. One type is a slightly curved round cooling channel and the other is hemispherical shape, both of which have only 2 mm gap distance and the water inlet is located on one side and flows out from the opposite side. In both cases, the central part of the flow area has lower velocity than peripheral area.

  12. GPU Parallel Bundle Block Adjustment

    Directory of Open Access Journals (Sweden)

    ZHENG Maoteng

    2017-09-01

    Full Text Available To deal with massive data in photogrammetry, we introduce the GPU parallel computing technology. The preconditioned conjugate gradient and inexact Newton method are also applied to decrease the iteration times while solving the normal equation. A brand new workflow of bundle adjustment is developed to utilize GPU parallel computing technology. Our method can avoid the storage and inversion of the big normal matrix, and compute the normal matrix in real time. The proposed method can not only largely decrease the memory requirement of normal matrix, but also largely improve the efficiency of bundle adjustment. It also achieves the same accuracy as the conventional method. Preliminary experiment results show that the bundle adjustment of a dataset with about 4500 images and 9 million image points can be done in only 1.5 minutes while achieving sub-pixel accuracy.

  13. Twist-off purification of hair bundles.

    Science.gov (United States)

    Shin, Jung-Bum; Pagana, James; Gillespie, Peter G

    2009-01-01

    Purification of hair bundles from inner-ear organs allows biochemical analysis of bundle constituents, including proteins and lipids. We describe here the "twist-off" method of bundle isolation, where dissected inner-ear organs are embedded in agarose, then subjected to a mechanical disruption that shears off bundles and leaves them in agarose blocks. With care in the dissection and in clean-up of the isolated bundles, contamination from cell bodies can be kept to a minimum. Isolated bundles can be analyzed by a variety of techniques, including immunocytochemistry, SDS-PAGE, immunoblotting, and mass spectrometry.

  14. Principal bundles the classical case

    CERN Document Server

    Sontz, Stephen Bruce

    2015-01-01

    This introductory graduate level text provides a relatively quick path to a special topic in classical differential geometry: principal bundles.  While the topic of principal bundles in differential geometry has become classic, even standard, material in the modern graduate mathematics curriculum, the unique approach taken in this text presents the material in a way that is intuitive for both students of mathematics and of physics. The goal of this book is to present important, modern geometric ideas in a form readily accessible to students and researchers in both the physics and mathematics communities, providing each with an understanding and appreciation of the language and ideas of the other.

  15. ADE bundles over surfaces with ADE singularities

    OpenAIRE

    Chen, Yunxia; Leung, Naichung Conan

    2012-01-01

    Given a complex projective surface with an ADE singularity and p_{g}=0, we construct ADE bundles over it and its minimal resolution. Furthermore, we descibe their minuscule representation bundles in terms of configurations of (reducible) (-1)-curves.

  16. PDS4 Bundle Creation Governance Using BPMN

    Science.gov (United States)

    Radulescu, C.; Levoe, S. R.; Algermissen, S. S.; Rye, E. D.; Hardman, S. H.

    2015-06-01

    The AMMOS-PDS Pipeline Service (APPS) provides a Bundle Builder tool, which governs the process of creating, and ultimately generates, PDS4 bundles incrementally, as science products are being generated.

  17. Developing the bundled glass column

    NARCIS (Netherlands)

    Oikonomopoulou, F.; Bristogianni, T; Veer, F.A.; Nijsse, R.; da Sousa Cruz, Paulo J.

    In this paper a bundled glass column is presented as a promising solution for a completely transparent, almost dematerialized structural compressive element. The aim is to ob-tain a glass column that can safely carry loads, achieve a high visual result and be relatively eas-ily manufactured.

  18. Line bundles and flat connections

    Indian Academy of Sciences (India)

    /fulltext/pmsc/127/03/0547-0549. Keywords. Calabi–Yau threefold; torsion; cocompact lattice; unitary representation. Abstract. We prove that there are cocompact lattices Γ in S L ( 2 , C ) with the property that there are holomorphic line bundles ...

  19. Line bundles and flat connections

    Indian Academy of Sciences (India)

    Calabi–Yau threefold; torsion; cocompact lattice; unitary representation. 2000 Mathematics Subject Classification. 81T30, 14D21, 53C07. 1. Stable bundles and unitary flat connections. 1.1 Admitting flat connections. Let X be a compact connected complex manifold of complex dimension δ. Let ω be the. (1, 1)-form on X ...

  20. Chemical vapor infiltration in single fiber bundles

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, D.J.; Barbero, R.S.; Currier, R.P.

    1990-01-01

    Chemical vapor infiltration (CVI) in single fiber bundles is studied under isothermal conditions. Understanding infiltration dynamics in single bundles is essential to process design and modeling efforts. Deposition of pyrolytic carbon in carbon-fiber bundles is chosen as the experimental system, with densification data obtained from thermogravimetric analysis. Data are then compared to predictions from a recently proposed CVI model for fiber bundle densification. 10 refs., 5 figs., 1 tab.

  1. Principal G-bundles on nodal curves

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    If Y is reducible these notions depend on parameters a = (a1,...,aI ). The study of G-bundles on Y is done by extending the notion of (generalized) parabolic vector bundles [U1] to generalized parabolic principal G-bundles (called GPGs in short) on the curve C and using the correspondence between them and principal ...

  2. Strategic and welfare implications of bundling

    DEFF Research Database (Denmark)

    Martin, Stephen

    1999-01-01

    A standard oligopoly model of bundling shows that bundling by a firm with a monopoly over one product has a strategic effect because it changes the substitution relationships between the goods among which consumers choose. Bundling in appropriate proportions is privately profitable, reduces rivals...

  3. The Atiyah bundle and connections on a principal bundle

    Indian Academy of Sciences (India)

    INDRANIL BISWAS. School of Mathematics, Tata Institute of Fundamental Research, Homi Bhabha Road,. Mumbai 400 005 .... (U) on A(EG)(U) and (U, g ⊕ Rd) defined by multiplication. Therefore, the sheaf A(EG) is locally free over FC∞. (M) of rank dim(g ⊕ Rd). Hence. A(EG) defines a C. ∞ vector bundle over M of rank ...

  4. Higher order jet prolongations type gauge natural bundles over vector bundles

    Directory of Open Access Journals (Sweden)

    Jan Kurek

    2004-05-01

    Full Text Available Let $rgeq 3$ and $mgeq 2$ be natural numbers and $E$ be a vector bundle with $m$-dimensional basis. We find all gauge natural bundles ``similar" to the $r$-jet prolongation bundle $J^rE$ of $E$. We also find all gauge natural bundles ``similar" to the vector $r$-tangent bundle $(J^r_{fl}(E,R_0^*$ of $E$.

  5. Multipath packet switch using packet bundling

    DEFF Research Database (Denmark)

    Berger, Michael Stubert

    2002-01-01

    The basic concept of packet bundling is to group smaller packets into larger packets based on, e.g., quality of service or destination within the packet switch. This paper presents novel applications of bundling in packet switching. The larger packets created by bundling are utilized to extend...... switching capacity by use of parallel switch planes. During the bundling operation, packets will experience a delay that depends on the actual implementation of the bundling and scheduling scheme. Analytical results for delay bounds and buffer size requirements are presented for a specific scheduling...

  6. 5 X 5 rod bundle flow field measurements downstream a PWR spacer grid

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Higor F.P.; Silva, Vitor V A.; Santos, André A.C.; Veloso, Maria A.F., E-mail: higorfabiano@gmail.com, E-mail: mdora@nuclear.ufmg.br, E-mail: vitors@cdtn.br, E-mail: aacs@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    The spacer grids are structures present in nuclear fuel assembly of Pressurized Water Reactors (PWR). They play an important structural role and also assist in heat removal through the assembly by promoting increased turbulence of the flow. Understanding the flow dynamics downstream the spacer grid is paramount for fuel element design and analysis. This paper presents water flow velocity profiles measurements downstream a spacer grid in a 5 x 5 rod bundle test rig with the objective of highlighting important fluid dynamic behavior near the grid and supplying data for CFD simulation validation. These velocity profiles were obtained at two different heights downstream the spacer grid using a LDV (Laser Doppler Velocimetry) through the top of test rig. The turbulence intensities and patterns of the swirl and cross flow were evaluated. The tests were conducted for Reynolds numbers ranging from 1.8 x 10{sup 4} to 5.4 x 10{sup 4}. This experimental research was carried out in thermo-hydraulics laboratory of Nuclear Technology Development Center – CDTN. Results show great repeatability and low uncertainties (< 1.24 %). Details of the flow field show how the mixture and turbulence induced by the spacer grid quickly decays downstream the spacer grid. It is shown that the developed methodology can supply high resolution low uncertainty results that can be used for validation of CFD simulations. (author)

  7. Computational fluid dynamic model for thermohydraulic calculation for the steady-state of the real scale HTR-1

    Energy Technology Data Exchange (ETDEWEB)

    Gamez, Abel; Rojas, Leorlen; Rosales, Jesus; Castro, Landy Y.; Gonzalez, Daniel; Garcia, Carlos, E-mail: agamezgmf@gmail.com, E-mail: leored1984@gmail.com, E-mail: jrosales@instec.cu, E-mail: lcastro@instec.cu, E-mail: danielgonro@gmail.com, E-mail: cgr@instec.cu [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana (Cuba); Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Oliveira, Carlos B. de, E-mail: cabol@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Dominguez, Dany S., E-mail: dsdominguez@gmail.com [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil)

    2015-07-01

    The high temperature gas cooled reactor (HTGR) is one of candidates of next generation of nuclear reactor according to IAEA report 2013. Evaluation of thermohydraulic performance and an experimental comparison results were proposed to the international research community. In this article, the tree dimensional CFD thermohydraulic modelation of steady state of HTR-10 modular reactor, using ANSYS CFX v14.0, has been done. Code-to-code and Code-to-experiment benchmark analyses, related to the testing program of the HTR-10 plant including steady state temperature distribution with the reactor at full power, were developed. The 3D real scale representation of reflector zone and fluid path flow inner and outer reflector blocks and cold helium cavity were carried out. The porous medium model was used to simulate the core zone in the reactor. The power distribution of the initial core published by IAEA-TECDOC-1694 obtained by Chief Scientific Investigators (CSIs) from China was used as heat sources in the core zone. (author)

  8. Coupling and elastic loading affect the active response by the inner ear hair cell bundles.

    Directory of Open Access Journals (Sweden)

    Clark Elliott Strimbu

    Full Text Available Active hair bundle motility has been proposed to underlie the amplification mechanism in the auditory endorgans of non-mammals and in the vestibular systems of all vertebrates, and to constitute a crucial component of cochlear amplification in mammals. We used semi-intact in vitro preparations of the bullfrog sacculus to study the effects of elastic mechanical loading on both natively coupled and freely oscillating hair bundles. For the latter, we attached glass fibers of different stiffness to the stereocilia and observed the induced changes in the spontaneous bundle movement. When driven with sinusoidal deflections, hair bundles displayed phase-locked response indicative of an Arnold Tongue, with the frequency selectivity highest at low amplitudes and decreasing under stronger stimulation. A striking broadening of the mode-locked response was seen with increasing stiffness of the load, until approximate impedance matching, where the phase-locked response remained flat over the physiological range of frequencies. When the otolithic membrane was left intact atop the preparation, the natural loading of the bundles likewise decreased their frequency selectivity with respect to that observed in freely oscillating bundles. To probe for signatures of the active process under natural loading and coupling conditions, we applied transient mechanical stimuli to the otolithic membrane. Following the pulses, the underlying bundles displayed active movement in the opposite direction, analogous to the twitches observed in individual cells. Tracking features in the otolithic membrane indicated that it moved in phase with the bundles. Hence, synchronous active motility evoked in the system of coupled hair bundles by external input is sufficient to displace large overlying structures.

  9. Transient response of a high-capacity heat pipe for Space Station Freedom

    Science.gov (United States)

    Ambrose, J. H.; Holmes, H. R.

    1991-01-01

    High-capacity heat pipe radiator panels have been proposed as the primary means of heat rejection for Space Station Freedom. In this system, the heat pipe would interface with the thermal bus condensers. Changes in system heat load can produce large temperature and heat load variations in individual heat pipes. Heat pipes could be required to start from an initially cold state, with heat loads temporarily exceeding their low-temperature transport capacity. The present research was motivated by the need for accurate prediction of such transient operating conditions. In this work, the cold startup of a 6.7-meter long high-capacity heat pipe is investigated experimentally and analytically. A transient thermohydraulic model of the heat pipe was developed which allows simulation of partially-primed operation. The results of cold startup tests using both constant temperature and constant heat flux evaporator boundary conditions are shown to be in good agreement with predicted transient response.

  10. Thermo-Hydraulic Analyses Associated with the Design of JT-60SA TF Coils Development and Validation of the Tacos/texto Tool

    Science.gov (United States)

    Lacroix, B.; Portafaix, C.; Hertout, P.; Nicollet, S.; Zani, L.; Barabaschi, P.; Villari, R.

    2010-04-01

    In the framework of the JT-60SA project, TF coils design activities have led to the development of TEXTO (Thermo-hydraulic EXtended TOol), a dedicated simulation tool centred on the GANDALF code for calculating the temperature margin (ΔTma) central criterion. From a first version providing conservative results, this tool has been upgraded to a pseudo 3D model by integrating a 1D thermo-hydraulic approach in ANSYS, leading to an additional and independent module named TACOS (Thermo-hydraulic Ansys COmputation Semi 3D). By providing He temperature in conductors, TACOS is well adapted for evaluating the impact of TF coils design choices in the framework of cost and feasibility optimization. TACOS also provides more accurate values of transverse heat flux from case to conductors, which can then be injected into TEXTO and allow the calculation of the temperature margin, thanks to the functionalities of GANDALF. Several validation calculations have been performed for the reference operation scenario, by comparison with GANDALF for validating the simplified thermo-hydraulic method of TACOS and by comparison with VINCENTA for an overall validation of the TACOS/TEXTO tool. Results have shown a good consistency between the different models, with a conductor temperature dispersion around 0.05 K in the critical zone.

  11. [Right Bundle Branch Block, Left Bundle Branch Block, Pace Maker in Case of Acute Coronary Syndrome - is the ECG of any Value?

    Science.gov (United States)

    Grautoff, Steffen

    2017-01-01

    The 12 lead ECG is difficult to evaluate if there is a persistent right or even left bundle block or a pace maker continually stimulating the right ventricle. Despite these pre-existing or new ECG changes it might still be possible to detect variations which can hint to an ST-elevation myocardial infarction (STEMI). Diagnosing significant ST elevations in a case of right bundle block is not very challenging. If the ECG shows a left bundle block the modified Sgarbossa criteria should be used for evaluation. These criteria can also be used in a pace maker ECG. If a patient is not pacemaker-dependent the stimulation can be paused transiently to reveal changes of the ST segment. At first medical contact it can be very important to assess these changes correctly in order to classify the ECG as a STEMI. © Georg Thieme Verlag KG Stuttgart · New York.

  12. Loss of feed flow, steam generator tube rupture and steam line break thermohydraulic experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mendler, O J; Takeuchi, K; Young, M Y

    1986-10-01

    The Westinghouse Model Boiler No. 2 (MB-2) steam generator test model at the Engineering Test Facility in Tampa, Florida, was reinstrumented and modified for performing a series of tests simulating steam generator accident transients. The transients simulated were: loss of feed flow, steam generator tube rupture, and steam line break events. This document presents a description of (1) the model boiler and the associated test facility, (2) the tests performed, and (3) the analyses of the test results.

  13. Static stress analysis of CANFLEX fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Suk, Ho Chun; Kang, Hee Young; Sim, Ki Seop; Jeong, Jang Hwan; Jun, Gi Su; Park, Ju Hwan; Lee, Che Han; Kim, Tae Hyoung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-02-01

    The static stress analysis of CANFLEX bundles is performed to evaluate the fuel structural integrity during the refuelling service. The structure analysis is carried out by predicting the drag force, stress and displacements of the fuel bundle. By the comparison of strength tests and analysis results, the displacement values are well agreed within 15%. The analysis shows that the CANFLEX fuel bundle keep its structural integrity. 24 figs., 6 tabs., 12 refs. (Author) .new.

  14. Evaluation of nonequilibrium effects in bundle dispersed-flow film boiling. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Morris, D.G.; Mullins, C.B.; Yoder, G.L.

    1983-01-01

    The effects of thermodynamic nonequilibrium in dispersed flow film boiling heat transfer are examined. Steady-state and transient rod-bundle data are used to evaluate several empirical heat-transfer models commonly employed to predict post-CHF behavior. The models that account for thermodynamic nonequilibrium perform adequately, while those that ignore nonequilibrium effects incur errors in wall superheat as high as 190/sup 0/K. Nonequilibrium effects can also be treated by explicitly modeling the phenomena. The thermal-hydraulic code COBRA-TF employs this approach. Using bundle data, the models in the code are evaluated. Analysis suggests that the interfacial heat transfer is overpredicted.

  15. Hydraulic characteristics of HANARO fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Cho, S.; Chung, H. J.; Chun, S. Y.; Yang, S. K.; Chung, M. K. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    This paper presents the hydraulic characteristics measured by using LDV (Laser Doppler Velocimetry) in subchannels of HANARO, KAERI research reactor, fuel bundle. The fuel bundle consists of 18 axially finned rods with 3 spacer grids, which are arranged in cylindrical configuration. The effects of the spacer grids on the turbulent flow were investigated by the experimental results. Pressure drops for each component of the fuel bundle were measured, and the friction factors of fuel bundle and loss coefficients for the spacer grids were estimated from the measured pressure drops. Implications regarding the turbulent thermal mixing were discussed. Vibration test results measured by using laser vibrometer were presented. 9 refs., 12 figs. (Author)

  16. Ulrich Schur bundles on flag varieties

    OpenAIRE

    Coskun, Izzet; Costa, Laura; Huizenga, Jack; Miró-Roig, Rosa Maria; Woolf, Matthew

    2015-01-01

    In this paper, we study equivariant vector bundles on partial flag varieties arising from Schur functors. We show that a partial flag variety with three or more steps does not admit an Ulrich bundle of this form with respect to the minimal ample class. We classify Ulrich bundles of this form on two-step flag varieties F(1,n-1;n), F(2,n-1;n), F(2,n-2;n), F(k,k+1;n) and F(k,k+2;n). We give a conjectural description of the two-step flag varieties which admit such Ulrich bundles.

  17. Equivariant Ulrich bundles on flag varieties

    OpenAIRE

    Coskun, Izzet; Huizenga, Jack; Woolf, Matthew

    2015-01-01

    In this paper, we study equivariant vector bundles on partial flag varieties arising from Schur functors. We show that a partial flag variety with three or more steps does not admit an Ulrich bundle of this form with respect to the minimal ample class. We classify Ulrich bundles of this form on two-step flag varieties F(2,n;n+1), F(2,n;n+2), F(k,k+1;n), and F(k,k+2;n). We give a conjectural description of the two-step flag varieties which admit such Ulrich bundles. Our results provide counter...

  18. Axis deviation without left bundle branch block.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Mancuso, Antonia

    2010-04-15

    It has been rarely reported changing axis deviation in the presence of left bundle branch block also during atrial fibrillation and with acute myocardial infarction too. It has also been rarely reported changing axis deviation with changing bundle branch block with onset of atrial fibrillation during acute myocardial infarction. We present a case of axis deviation without left bundle branch block and without atrial fibrillation and acute myocardial infarction in a 65-year-old Italian man. To our knowledge, this is the first report of axis deviation without left bundle branch block and without atrial fibrillation and acute myocardial infarction. Copyright 2008 Elsevier Ireland Ltd. All rights reserved.

  19. Thermohydraulic analysis of high-Prandtl-number fluid in complex duct simulating first wall in fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Satake, Masaaki [Advanced Fusion Reactor Engineering Laboratory, Department of Quantum Science and Energy Engineering, Graduate School of Engineering Tohoku University, Aramaki-Aza-Aoba 6-6-01-2, Aoba-ku, Sendai, Miyagi 980-8579 (Japan)], E-mail: msata@karma.qse.tohoku.ac.jp; Yuki, Kazuhisa [Advanced Fusion Reactor Engineering Laboratory, Department of Quantum Science and Energy Engineering, Graduate School of Engineering Tohoku University, Aramaki-Aza-Aoba 6-6-01-2, Aoba-ku, Sendai, Miyagi 980-8579 (Japan)], E-mail: kyuki@qse.tohoku.ac.jp; Hashizume, Hidetoshi [Advanced Fusion Reactor Engineering Laboratory, Department of Quantum Science and Energy Engineering, Graduate School of Engineering Tohoku University, Aramaki-Aza-Aoba 6-6-01-2, Aoba-ku, Sendai, Miyagi 980-8579 (Japan)], E-mail: hidetoshi.hashizume@qse.tohoku.ac.jp

    2010-04-15

    For fusion reactors, molten salt is one of the candidates for coolant materials. Molten salt is a high-Prandtl-number fluid; thus, it is necessary to enhance the heat transfer coefficient. It is proposed that rods are inserted into a duct to enhance the heat transfer coefficient. The flow field behind the rod in the duct is visualized to compare experimental data with simulation results. The trends and distributions in the numerical simulation are the same as those in the experiment, and furthermore, the magnitudes of the time and space scales in the numerical simulation are of the same order as those in the experiment. Thermohydraulic numerical analysis confirmed that the heat transfer coefficient is improved by inserting the rod when the fluid is a high-Prandtl-number fluid and the flow field is in the turbulent region. However, it is necessary for the rods to be arranged in the streamwise direction.

  20. Thermohydraulic stability coupled to the neutronic in a BWR; Estabilidad termohidraulica acoplada a la neutronica en un BWR

    Energy Technology Data Exchange (ETDEWEB)

    Calleros M, G.; Zapata Y, M.; Gomez H, R.A.; Mendez M, A. [Comision Federal de Electricidad, Central Nucleoelectrica de Laguna Verde, Carretera Cardel-Nautla Km. 42.5, Mpio. Alto Lucero, Veracruz (Mexico); Castlllo D, R. [ININ, Carretera Mexico-Toluca Km 36.5, La Marquesa, Estado de Mexico (Mexico)]. e-mail: gcm9acpp@cfe.gob.mx

    2006-07-01

    In a BWR type reactor the phenomenon of the nuclear fission is presented, in which are liberated in stochastic form neutrons, originating that the population of the same ones varies in statistic form around a mean value. This variation will cause that when the neutron flow impacts on the neutron detectors, its are had as a result neutron flow signals with fluctuations around an average value. In this article it is shown that it conforms it lapses the time, this variations in the neutron flow (and therefore, in the flow signal due only to the fission), they presented oscillations inside a stable range, which won't be divergent. Considering that the BWR is characterized because boiling phenomena are presented, which affect the moderation of the neutrons, additional variations will be had in the signal coming from the neutron detectors, with relationship to the fission itself, which will be influenced by the feedback of the moderator's reactivity and of the temperature of the fuel pellet. Also, as the BWR it has coupled control systems to maintain the coolant level one and of the thermal power of the reactor, for each control action it was affected the neutron population. This means that the reactor could end up straying of a stable state condition. By it previously described, the study of the thermohydraulic stability coupled to the neutronic is complex. In this work it is shown the phenomenology, the mathematical models and the theoretical behavior associated to the stability of the BWR type reactor; the variables that affect it are identified, the models that reproduce the behavior of the thermohydraulic stability coupled to the neutronic, the way to maintain stable the reactor and the instrumentation that can settle to detect and to suppress uncertainties is described. In particular, is make reference to the evolution of the methods to maintain the stability of the reactor and the detection system and suppression of uncertainties implemented in the

  1. HEMERA: a 3D coupled core-plant system for accidental reactor transient simulation

    Energy Technology Data Exchange (ETDEWEB)

    Bruna, G.B.; Fouquet, F.; Dubois, F. [Institut de Radioprotection et de Surete Nucleaire, 92 - Fontenay aux Roses (France); Le Pallec, J.C.; Richebois, E.; Hourcade, E.; Poinot-Salanon, C.; Royer, E. [CEA Saclay, Dir. de l' Energie Nucleaire (DEN/DM2S), 91 - Gif sur Yvette (France)

    2007-07-01

    In the framework of their collaboration to develop a system to study reactor transients in safety-representative conditions, IRSN (Radioprotection and Nuclear Safety Institute) and Cea have launched the development of a fully coupled 3-dimensional computational chain, called HEMERA (Highly Evolutionary Methods for Extensive Reactor Analyses), based on the French SAPHYR code system, composed of APOLLO-2, CRONOS-2 and FLICA-4 codes, and the system code CATHARE. It includes cross sections generation, steady-state, depletion and transient computation capabilities in a consistent approach. Multi-level and multi-dimensional models are developed to account for neutronics, core thermal-hydraulics, fuel thermal analysis and system thermohydraulics. Currently Control Rod Ejection (RIA) and Main Steam Line Break (MSLB) accidents are investigated. The HEMERA system is presently applied to French PWR. The present paper outlines the main physical phenomena to be accounted for in such a coupled computational chain with significant time and space effects.

  2. Calculations of multidimensional test reactor neutron diffusion problems with KORAT 3D code and its combination with two-velocity two-temperature thermohydraulic RATEG code

    Energy Technology Data Exchange (ETDEWEB)

    Voronova, O.A.; Grebennikov, A.N.; Zvenigorodskaya, O.A. [Russian Federal Nuclear Center, Arzamas (Russian Federation)] [and others

    1996-09-01

    The paper briefly presents the method for numerical computation of 3-D group neutron diffusion equation implemented in KORAT 3D code within SATURN complex and oriented to 3-D stationary and nonstationary calculations in nuclear reactor physics including those on up-to-date distributed-memory multiprocessors. The computational results are given obtained with the above mentioned code for multidimensional test reactor problems as well as the results of numerical efficiency studies for the code parallelization on multiprocessors Cray T3D and SP-2. Then the setup is given for 3-D dynamic problem simulating a hypothetical mode of WPBER reactor. The computational results are presented for the above problem which includes the neutron-nuclear processes, thermohydraulic processes and the feedback. The computations used two program complexes: KORAT 3D + multichannel two-velocity two-temperature thermohydraulics code RATEG and READY complex. (author)

  3. Application of thermohydraulic dispatcher in low temperature district heating systems for decreasing heat carrier transportation energy cost and increasing reliability of heat supply

    Science.gov (United States)

    Yavorovsky, Y. V.; Romanov, D. O.; Sennikov, V. V.; Sultanguzin, I. A.; Malenkov, A. S.; Zhigulina, E. V.; Lulaev, A. V.

    2017-11-01

    Low pressure district heating systems have low breakdown rate and allow decreasing heat carrier transportation energy cost by means of avoiding throttling of available water head. One of the basic elements of such systems is thermohydraulic dispatcher (THD) which separates primary circuit and secondary circuit (or circuits) that allows avoiding mutual hydraulic influence of circuits on each other and reducing water heads of network pumps. Analysis of perspective ways of using thermohydraulic dispatcher (THD) in low temperature district heating systems is made in this paper. Principal scheme and mathematical model of low pressure and temperature district heating system based on CHP generation with THD are considered. The main advantages of such systems are pointed out.

  4. Subchannel Code Benchmarking to Columbia University 4x4 and Pacific Northwest Laboratory 2x6 Bundle Test Data

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Kang Hoon; Oezdemir, Erdal; Oh, Seung Jong [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2014-10-15

    The subchannel code is used to assess the safety of a reactor core at the steady-state and transient conditions. KEPCO Nuclear Fuel (KNF) has been developed new subchannel code, THALES, for PWR core design application. In this study, we are comparing the THALES result with VIPRE-01 code result utilizing bundle test data. VIPRE-01 was developed under EPRI sponsorship and has been used by U.S. PWR commercial nuclear utilities, historically. THALES and VIPRE-01 codes were benchmarked to two kind of bundle test data which were at the steady-state and transient conditions. THALES predicted fluid velocity and temperature profile of bundle test data well and the error rate between THALES and VIPRE-01 was very small.

  5. Neutronics and thermohydraulics of the reactor C.E.N.E. Part II; Analisis neutronico y termohidraulico del reactor C.E.N.E. Parte II

    Energy Technology Data Exchange (ETDEWEB)

    Caro, R.

    1976-07-01

    In this report the analysis of neutronics thermohydraulics and shielding of the 10 HWt swimming pool reactor C.E.N.E is included. In each of these chapters is given a short description of the theoretical model used, along with the theoretical versus experimental checking carried out, whenever possible, with the reactors JEN-I and JEN-II of Junta de Energia Nuclear. (Author) 11 refs.

  6. Adaptation and implementation of the TRACE code for transient analysis on designs of cooled lead fast reactors; Adaptacion y aplicacion del codigo TRACE para el analisis de transitorios en disenos de reactores rapidos refrigerados por plomo

    Energy Technology Data Exchange (ETDEWEB)

    Lazaro, A.; Ammirabile, L.; Martorell, S.

    2014-07-01

    The article describes the changes implemented in the TRACE code to include thermodynamic tables of liquid lead drawn from experimental results. He then explains the process for developing a thermohydraulic model for the prototype ALFRED and analysis of a selection of representative transient conducted within the framework of international research projects. The study demonstrates the applicability of TRACE code to simulate designs of cooled lead fast reactors and exposes the high safety margins are there in this technology to accommodate the most severe transients identified in their security study. (Author)

  7. Why (almost) all bundles are chiral

    Science.gov (United States)

    Kost-Smith, Zachary V.; Blackwell, Robert A.; Glaser, Matthew A.

    2014-03-01

    We examine the self assembly of bundles of achiral hard rods with distributed, short-range attractive interactions. We show that in the majority of cases the equilibrium state of the bundle is chiral, with a double twist structure. We use biased Monte Carlo techniques and cell theory to compute the free energy as a function of an appropriately defined twist order parameter, and show that the formation of spontaneously chiral bundles is driven by maximization of orientational entropy. The finite curvature of the bundle boundary permits orientational escape, in which the circumferential angular range of motion of the rods is maximized for some finite average tilt. We map out the phase diagram of bundles in terms of the density, the ratio of rod length to bundle radius, L / R , and rod aspect ratio, L / D , and find transitions between untwisted, weakly twisted, and strongly twisted states. This work helps explain the common observation of twisted macroscopic bundles, and may provide insight into observations of twist in self-assembled membranes of colloidal rods.[2] This work funded by NSF MRSEC Grant DMR-0820579.

  8. Einstein metrics on tangent bundles of spheres

    Energy Technology Data Exchange (ETDEWEB)

    Dancer, Andrew S [Jesus College, Oxford University, Oxford OX1 3DW (United Kingdom); Strachan, Ian A B [Department of Mathematics, University of Hull, Hull HU6 7RX (United Kingdom)

    2002-09-21

    We give an elementary treatment of the existence of complete Kaehler-Einstein metrics with nonpositive Einstein constant and underlying manifold diffeomorphic to the tangent bundle of the (n+1)-sphere.

  9. Dynamic bi-product bundle pricing problem

    Directory of Open Access Journals (Sweden)

    Rafiei Hamed

    2014-01-01

    Full Text Available This paper addresses bundle pricing problem of two products in a stochastic environment so as to maximize net profit of a retailer. In the considered problem, it is assumed that customers are received upon a Poisson distribution and their demands follow a bi-variant distribution function. Also, it is assumed that products are sold individually or in the form of a bundle, which are offered from an initial stock of the products. To tackle the problem, a stochastic dynamic program is developed in which optimum values of the initial stock and order quantities of every planning period are determined. Moreover, prices of the individual products and their bundle are optimized. Also, the proposed dynamic program tackles bundling/ unbundling decisions taken in every planning period. A numerical example of a two planning period horizon is considered to validate the proposed model.

  10. Preliminary Thermo-hydraulic Core Design Analysis of Korea Advanced Nuclear Thermal Engine Rocket for Space Application

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Seung Hyun; Lee, Jeong Ik; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    {sub th} power and electricity generation with 100 kW{sub th} idle power. Consequently, KANUTER has the characteristics of a compact and lightweight system, excellent propellant efficiency, bimodal capability, and mission versatility as indicated in the reference design parameters. This thermo-hydraulic design analysis was carried out to estimate the optimum FWT of the unique SLHC fuel design in the core and thereby the maximum rocket performance. The FWT affects the mechanical strength of the SLHC fuel assembly as well as the thermo-hydraulic capability mainly depending on the heat transfer area of fuel. The thicker fuel wafer is mechanically strong with low pressure drop, while the thinner fuel wafer is thermally robust with less mechanical strength and higher shear stress in the core.

  11. Is It Complete Left Bundle Branch Block? Just Ablate the Right Bundle.

    Science.gov (United States)

    Ali, Hussam; Lupo, Pierpaolo; Foresti, Sara; De Ambroggi, Guido; Epicoco, Gianluca; Fundaliotis, Angelica; Cappato, Riccardo

    2017-03-01

    Complete left bundle branch block (LBBB) is established according to standard electrocardiographic criteria. However, functional LBBB may be rate-dependent or can perpetuate during tachycardia due to repetitive concealed retrograde penetration of impulses through the contralateral bundle "linking phenomenon." In this brief article, we present two patients with basal complete LBBB in whom ablating the right bundle unmasked the actual antegrade conduction capabilities of the left bundle. These cases highlight intriguing overlap between electrophysiological concepts of complete block, linking, extremely slow, and concealed conduction. © 2016 Wiley Periodicals, Inc.

  12. Physiological mechanisms of QRS narrowing in bundle branch block patients undergoing permanent His bundle pacing.

    Science.gov (United States)

    Teng, Alexandra E; Massoud, Louis; Ajijola, Olujimi A

    2016-01-01

    His bundle pacing is increasingly used to avoid chronic right ventricular pacing, and electrically resynchronize ventricular activation by narrowing or normalizing the QRS interval in left and right bundle branch block. The mechanisms by which this occurs remain poorly understood. In this review, the proposed mechanisms and evidence supporting them are discussed. Also discussed are aspects of mechanisms that are not completely supported by the evidence. We also review the differences and physiological bases for direct vs. indirect His bundle capture, and the physiological mechanisms for QRS narrowing vs. normalization following His bundle pacing. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Measurements of Flow Mixing at Subchannels in a Wire-Wrapped 37-Rod Bundle for a Sodium Cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyungmo; Bae, Hwang; Chang, Seok-Kyu; Choi, Sun Rock; Lee, Dong Won; Ko, Yung Joo; Choi, Hae Seob; Euh, Dong-Jin; Lee, Hyeong-Yeon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    For a safety analysis in a core thermal design of a sodium-cooled fast reactor (SFR), flow mixing characteristics at subchannels in a wire-wrapped rod bundle are very important. Wrapped wires make a cross flow in a around the fuel rod) of the fuel rod, and this effect lets flow be mixed. Experimental results of flow mixing can be meaningful for verification and validation of thermal mixing correlation in a reactor core thermo-hydraulic design code. A wire mesh sensing technique can be useful method for measuring of flow mixing characteristics. A wire mesh sensor has been traditionally used to measure the void fraction of a two-phase flow field, i.e. gas and liquid. However, it has been recently reported that the wire mesh sensor can be used successfully to recognize the flow field in liquid phase by injecting a tracing liquid with a different level of electric conductivity. This can be powerfully adapted to recognize flow mixing characteristics by wrapped wires in SFR core thermal design. In this work, we conducted the flow mixing experiments using a custom designed wire mesh sensor. To verify and validate computer codes for the SFR core thermal design, mixing experiments were conducted at a hexagonally arrayed 37-pin wire-wrapped fuel rod bundle test section. The well-designed wire mesh sensor was used to measure flow mixing characteristics. The developed post-processing method has its own merits, and flow mixing results were reasonable. In addition, by uncertainty analysis, the system errors and the random error were estimated in experiments. Therefore, the present results and methods can be used for design code verification and validation.

  14. IAEA coordinated research program on `harmonization and validation of fast reactor thermomechanical and thermohydraulic codes using experimental data`. 1. Thermohydraulic benchmark analysis on high-cycle thermal fatigue events occurred at French fast breeder reactor Phenix

    Energy Technology Data Exchange (ETDEWEB)

    Muramatsu, Toshiharu [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1997-06-01

    A benchmark exercise on `Tee junction of Liquid Metal Fast Reactor (LMFR) secondary circuit` was proposed by France in the scope of the said Coordinated Research Program (CRP) via International Atomic Energy Agency (IAEA). The physical phenomenon chosen here deals with the mixture of two flows of different temperature. In a LMFR, several areas of the reactor are submitted to this problem. They are often difficult to design, because of the complexity of the phenomena involved. This is one of the major problems of the LMFRs. This problem has been encountered in the Phenix reactor on the secondary loop, where defects in a tee junction zone were detected during a campaign of inspections after an operation of 90,000 hours of the reactor. The present benchmark is based on an industrial problem and deal with thermal striping phenomena. Problems on pipes induced by thermal striping phenomena have been observed in some reactors and experimental facilities coolant circuits. This report presents numerical results on thermohydraulic characteristics of the benchmark problem, carried out using a direct numerical simulation code DINUS-3 and a boundary element code BEMSET. From the analysis with both the codes, it was confirmed that the hot sodium from the small pipe rise into the cold sodium of the main pipe with thermally instabilities. Furthermore, it was indicated that the coolant mixing region including the instabilities agrees approximately with the result by eye inspections. (author)

  15. Thermo-Hydraulic Analysis of Heat Storage Filled with the Ceramic Bricks Dedicated to the Solar Air Heating System.

    Science.gov (United States)

    Nemś, Magdalena; Nemś, Artur; Kasperski, Jacek; Pomorski, Michał

    2017-08-12

    This article presents the results of a study into a packed bed filled with ceramic bricks. The designed storage installation is supposed to become part of a heating system installed in a single-family house and eventually to be integrated with a concentrated solar collector adapted to climate conditions in Poland. The system's working medium is air. The investigated temperature ranges and air volume flow rates in the ceramic bed were dictated by the planned integration with a solar air heater. Designing a packed bed of sufficient parameters first required a mathematical model to be constructed and heat exchange to be analyzed, since heat accumulation is a complex process influenced by a number of material properties. The cases discussed in the literature are based on differing assumptions and different formulas are used in calculations. This article offers a comparison of various mathematical models and of system operating parameters obtained from these models. The primary focus is on the Nusselt number. Furthermore, in the article, the thermo-hydraulic efficiency of the investigated packed bed is presented. This part is based on a relationship used in solar air collectors with internal storage.

  16. Capabilities needed for the next generation of thermo-hydraulic codes for use in real time applications

    Energy Technology Data Exchange (ETDEWEB)

    Arndt, S.A.

    1997-07-01

    The real-time reactor simulation field is currently at a crossroads in terms of the capability to perform real-time analysis using the most sophisticated computer codes. Current generation safety analysis codes are being modified to replace simplified codes that were specifically designed to meet the competing requirement for real-time applications. The next generation of thermo-hydraulic codes will need to have included in their specifications the specific requirement for use in a real-time environment. Use of the codes in real-time applications imposes much stricter requirements on robustness, reliability and repeatability than do design and analysis applications. In addition, the need for code use by a variety of users is a critical issue for real-time users, trainers and emergency planners who currently use real-time simulation, and PRA practitioners who will increasingly use real-time simulation for evaluating PRA success criteria in near real-time to validate PRA results for specific configurations and plant system unavailabilities.

  17. Limitations of transient power loads on DEMO and analysis of mitigation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Maviglia, F., E-mail: francesco.maviglia@euro-fusion.org [EUROfusion Consortium, PPPT Department, Boltzmannstr. 2, Garching (Germany); Consorzio CREATE, University Napoli Federico II – DIETI, 80125 Napoli (Italy); Federici, G. [EUROfusion Consortium, PPPT Department, Boltzmannstr. 2, Garching (Germany); Strohmayer, G. [Max-Planck-Institut fur Plasmaphysik, Boltzmannstr. 2, Garching (Germany); Wenninger, R. [EUROfusion Consortium, PPPT Department, Boltzmannstr. 2, Garching (Germany); Max-Planck-Institut fur Plasmaphysik, Boltzmannstr. 2, Garching (Germany); Bachmann, C. [EUROfusion Consortium, PPPT Department, Boltzmannstr. 2, Garching (Germany); Albanese, R. [Consorzio CREATE, University Napoli Federico II – DIETI, 80125 Napoli (Italy); Ambrosino, R. [Consorzio CREATE University Napoli Parthenope, Naples (Italy); Li, M. [Max-Planck-Institut fur Plasmaphysik, Boltzmannstr. 2, Garching (Germany); Loschiavo, V.P. [Consorzio CREATE, University Napoli Federico II – DIETI, 80125 Napoli (Italy); You, J.H. [Max-Planck-Institut fur Plasmaphysik, Boltzmannstr. 2, Garching (Germany); Zani, L. [CEA, IRFM, F-13108 St Paul-Lez-Durance (France)

    2016-11-01

    Highlights: • A parametric thermo-hydraulic analysis of the candidate DEMO divertor is presented. • The operational space assessment is presented under static and transient heat loads. • Strike points sweeping is analyzed as a divertor power exhaust mitigation technique. • Results are presented on sweeping installed power required, AC losses and thermal fatigue. - Abstract: The present European standard DEMO divertor target technology is based on a water-cooled tungsten mono-block with a copper alloy heat sink. This paper presents the assessment of the operational space of this technology under static and transient heat loads. A transient thermo-hydraulic analysis was performed using the code RACLETTE, which allowed a broad parametric scan of the target geometry and coolant conditions. The limiting factors considered were the coolant critical heat flux (CHF), and the temperature limits of the materials. The second part of the work is devoted to the study of the plasma strike point sweeping as a mitigation technique for the divertor power exhaust. The RACLETTE code was used to evaluate the impact of a large range of sweeping frequencies and amplitudes. A reduced subset of cases, which complied with the constraints, was benchmarked with a 3D FEM model. A reduction of the heat flux to the coolant, up to a factor ∼4, and lower material temperatures were found for an incident heat flux in the range (15–30) MW/m{sup 2}. Finally, preliminary assessments were performed on the installed power required for the sweeping, the AC losses in the superconductors and thermal fatigue analysis. No evident show stoppers were found.

  18. Analysis Thermo-hydraulic of trajectories related to procedures for operation of Emergency (POE). Application to the loss of a train of the DTH; Analisis termohidraulico de trayectorias vinculadas a Procedimientos de Operacion de emergencia (POE). Aplicacion a la perdida de un tren de RHR

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Saez, F.; Martorell Alsina, S.; Carlos Alberola, A.; Villanueva Lopez, J. F.; Martorell Aygues, P.

    2012-07-01

    This work explores different possible sequences at the loss of a train of the DTH when the plant is lowering power. The study of the different possible trajectories has been done through the collapse tool and study thermo-hydraulic each of these paths is done by the code TRACE Thermo-hydraulic.

  19. Biomechanics of the porcine triple bundle anterior cruciate ligament.

    Science.gov (United States)

    Kato, Yuki; Ingham, Sheila J M; Linde-Rosen, Monica; Smolinski, Patrick; Horaguchi, Takashi; Fu, Freddie H

    2010-01-01

    Several species of animals are used as a model to study human anterior cruciate ligament (ACL) reconstruction. In many animals, three bundles were clearly discernible during dissection in the ACL. However, there are few reports about the biomechanical role of each bundle in the porcine knee. The purpose of this study is to investigate the role of each of the three bundles in the porcine knee, especially the intermediate bundle. Ten porcine knees were tested using a robotic/universal forcemoment sensor system. This system applied anterior loading of 89 N at 30 degrees, 60 degrees and 90 degrees of flexion, and a combined 7 Nm valgus and 4 Nm internal tibial torque at 30 degrees and 60 degrees of flexion before and after each bundle was selectively cut. The in situ force (N) for each bundle of the ACL was measured. Both intermediate (IM) bundle and postero-lateral (PL) bundle had significantly lower in situ force than the antero-medial (AM) bundle in anterior loading. The IM and PL bundles carried a larger proportion of the force under the torsional loads than the anterior loads. But IM bundle had a significant lower in situ force during the combined torque at 60 degrees of knee flexion, when compared intact ACL. In summary, IM bundle has a subordinate role to the AM and PL bundles. AM bundle is more dominant than IM and PL bundles. The porcine knee is a suitable model for ACL studies, especially for AP stability.

  20. Stability of Picard bundle over moduli space of stable vector bundles ...

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    Stability of Picard bundle over moduli space of stable vector bundles of rank two over a curve. INDRANIL BISWAS and TOM ´AS L G ´OMEZ. School of Mathematics, Tata Institute of Fundamental Research, Homi Bhabha Road,. Mumbai 400 005, India. E-mail: indranil@math.tifr.res.in; tomas@math.tifr.res.in. MS received 14 ...

  1. Stability of Picard bundle over moduli space of stable vector bundles ...

    Indian Academy of Sciences (India)

    Abstract. Answering a question of [BV] it is proved that the Picard bundle on the moduli space of stable vector bundles of rank two, on a Riemann surface of genus at least three, with fixed determinant of odd degree is stable.

  2. Temperature Distributions in LMR Fuel Pin Bundles as Modeled by COBRA-IV-I

    Science.gov (United States)

    Wright, Steven A.; Stout, Sherry

    2005-02-01

    Most pin type reactor designs for space power or terrestrial applications group the fuel pins into a number of relatively large fuel pin bundles or subassemblies. Fuel bundles for terrestrial liquid metal fast breeders reactors typically use 217 - 271 pins per sub-assembly, while some SP100 designs use up to 331 pins in a central subassembly that was surrounded by partial assemblies. Because thermal creep is exponentially related to temperature, small changes in fuel pin cladding temperature can make large differences in the lifetime in a high temperature liquid metal reactor (LMR). This paper uses the COBRA-IV-I computer code to determine the temperature distribution within LMR fuel bundles. COBRA-IV-I uses the sub-channel analysis approach to determine the enthalpy (or temperature) and flow distribution in rod bundles for both steady-state and transient conditions. The COBRA code runs in only a few seconds and has been benchmarked and tested extensively over a wide range of flow conditions. In this report the flow and temperature distributions for two types of lithium cooled space reactor core designs were calculated. One design uses a very tight fuel pin packing that has a pitch to diameter ratio of 1.05 (small wire wrap with a diameter of 392 μm) as proposed in SP100. The other design uses a larger pitch to diameter ratio of 1.09 with a larger more conventional sized wire wrap diameter of 1 mm. The results of the COBRA pin bundle calculations show that the larger pitch-to-diameter fuel bundle designs are more tolerant to local flow blockages, and in addition they are less sensitive to mal-flow distributions that occur near the edges of the subassembly.

  3. Cooperative retraction of bundled type IV pili enables nanonewton force generation.

    Directory of Open Access Journals (Sweden)

    Nicolas Biais

    2008-04-01

    Full Text Available The causative agent of gonorrhea, Neisseria gonorrhoeae, bears retractable filamentous appendages called type IV pili (Tfp. Tfp are used by many pathogenic and nonpathogenic bacteria to carry out a number of vital functions, including DNA uptake, twitching motility (crawling over surfaces, and attachment to host cells. In N. gonorrhoeae, Tfp binding to epithelial cells and the mechanical forces associated with this binding stimulate signaling cascades and gene expression that enhance infection. Retraction of a single Tfp filament generates forces of 50-100 piconewtons, but nothing is known, thus far, on the retraction force ability of multiple Tfp filaments, even though each bacterium expresses multiple Tfp and multiple bacteria interact during infection. We designed a micropillar assay system to measure Tfp retraction forces. This system consists of an array of force sensors made of elastic pillars that allow quantification of retraction forces from adherent N. gonorrhoeae bacteria. Electron microscopy and fluorescence microscopy were used in combination with this novel assay to assess the structures of Tfp. We show that Tfp can form bundles, which contain up to 8-10 Tfp filaments, that act as coordinated retractable units with forces up to 10 times greater than single filament retraction forces. Furthermore, single filament retraction forces are transient, whereas bundled filaments produce retraction forces that can be sustained. Alterations of noncovalent protein-protein interactions between Tfp can inhibit both bundle formation and high-amplitude retraction forces. Retraction forces build over time through the recruitment and bundling of multiple Tfp that pull cooperatively to generate forces in the nanonewton range. We propose that Tfp retraction can be synchronized through bundling, that Tfp bundle retraction can generate forces in the nanonewton range in vivo, and that such high forces could affect infection.

  4. Control of the neutronic and thermohydraulic conditions of power ramps in an irradiation loop for PWR fuel rod; Controle des conditions neutroniques et thermohydrauliques des rampes de puissance dans une boucle d`irradiation de combustibles de reacteur a eau pressurisee

    Energy Technology Data Exchange (ETDEWEB)

    Moulin, D.J.F.

    1993-09-10

    In order to study the power transients effects on PWR fuel rod clad, ramp tests in a pressurized water loop, are carried out at OSIRIS reactor. The present thesis deals with the on-line control of the device, during power ramp and conditioning irradiation. Based on a convolution-type resolution of the kinetics equations, a dynamic compensation of the Silver self-powered neutron detector was developed. With this method, the uncertainty of the ramp end-point is lower than 1%, thus it is very suited for monitoring both transient, as well as steady state conditions. Furthermore, a thermohydraulic model of the irradiation device is described: heat transfer equations, including gamma heating in materials, are solved to obtain temperatures and thermal fluxes of steady states. Results from the model and temperature measurements of the coolant are used together for fuel power determination, in real time. The clad external temperature profile is also calculated and displayed, to improve the irradiation monitoring. (author), 51 refs., 12 annexes, 66 figs.

  5. Experimental investigation of the impulse gas injection into liquid and the use of experimental data for verification of the HYDRA-IBRAE/LM thermohydraulic code

    Science.gov (United States)

    Lobanov, P. D.; Usov, E. V.; Butov, A. A.; Pribaturin, N. A.; Mosunova, N. A.; Strizhov, V. F.; Chukhno, V. I.; Kutlimetov, A. E.

    2017-10-01

    Experiments with impulse gas injection into model coolants, such as water or the Rose alloy, performed at the Novosibirsk Branch of the Nuclear Safety Institute, Russian Academy of Sciences, are described. The test facility and the experimental conditions are presented in details. The dependence of coolant pressure on the injected gas flow and the time of injection was determined. The purpose of these experiments was to verify the physical models of thermohydraulic codes for calculation of the processes that could occur during the rupture of tubes of a steam generator with heavy liquid metal coolant or during fuel rod failure in water-cooled reactors. The experimental results were used for verification of the HYDRA-IBRAE/LM system thermohydraulic code developed at the Nuclear Safety Institute, Russian Academy of Sciences. The models of gas bubble transportation in a vertical channel that are used in the code are described in detail. A two-phase flow pattern diagram and correlations for prediction of friction of bubbles and slugs as they float up in a vertical channel and of two-phase flow friction factor are presented. Based on the results of simulation of these experiments using the HYDRA-IBRAE/LM code, the arithmetic mean error in predicted pressures was calculated, and the predictions were analyzed considering the uncertainty in the input data, geometry of the test facility, and the error of the empirical correlation. The analysis revealed major factors having a considerable effect on the predictions. The recommendations are given on updating of the experimental results and improvement of the models used in the thermohydraulic code.

  6. The simulation of thermohydraulic phenomena in a pressurized water reactor primary loop

    Energy Technology Data Exchange (ETDEWEB)

    Popp, M

    1987-01-01

    Several important fluid flow and heat transfer phenomena essential to nuclear power reactor safety were investigated. Scaling and modeling laws for pressurized water reactors are reviewed and a new scaling approach focusing on the overall loop behavior is presented. Scaling criteria for one- and two-phase natural circulation are developed, as well as a simplified model describing the first phase of a small break loss of coolant accident. Reactor vessel vent valve effects are included in the analysis of steady one-phase natural circulation flow. Two new dimensionless numbers, which uniquely describe one-phase flow in natural circulation loops, were deduced and are discussed. A scaled model of the primary loop of a typical Babcock and Wilcox reactor was designed, built, and tested. The particular prototype modeled was the TMI unit 2 reactor. The electrically heated, stainless steel model operates at a maximum pressure of 300 psig and has a maximum heat input of 188 kW. The model is about 4 times smaller in height than the prototype reactor, with a nominal volume scale of 1:500. Experiments were conducted establishing subcooled natural circulation in the model loop. Both steady flow and power transients were investigated.

  7. Thermohydraulic study of a MTR fuel element aimed at the construction of an irradiation facility; Estudo termohidraulico de um elemento combustivel tipo MTR visando a construcao de um dispositivo de irradiacao

    Energy Technology Data Exchange (ETDEWEB)

    Coragem, Helio Boemer de Oliveira

    1980-07-01

    A thermohydraulic study of MTR fuel element is presented as a basic requirement for the development of an irradiation facility for testing fuel elements. A computer code named 'Thermo' has been developed for this purpose, which can stimulate different working conditions, such as, cooling, power elements and neutron flux, performing all pertinent thermohydraulic calculations. Thermocouples were used to measure the temperature gradients of the cooling fluid throughout the IEAR-1 reactor core. All experimental data are in good agreement with the theoretical model applied in this work. Finally, a draft of the proposed facility and its safety system is presented. (author)

  8. Development and application of an innovative tool to automate the process of results extraction from the thermo-hydraulic simulator Olga

    Directory of Open Access Journals (Sweden)

    Francesco Carducci

    2015-06-01

    Full Text Available This paper presents the development and application of an innovative code to extract in an automated way data from the thermo-hydraulic simulator Olga. The results show that the tool can significantly reduce the time needed for the data extraction procedure and increase the reliability of results due to the fact that there is no more the need of the human operator. Moreover, during the data extraction phase, the Olga code is available for running different simulations allowing to optimize the use of this resource.

  9. Reactor transient

    Energy Technology Data Exchange (ETDEWEB)

    Menegus, R.L.

    1956-05-31

    The authors are planning a calculation to be done on the Univac at the Louviers Building to estimate the effect of xenon transients, a high reactor power. This memorandum outlines the reasons why they prefer to do the work at Louviers rather than at another location, such as N.Y.U. They are to calculate the response of the reactor to a sudden change in position of the half rods. Qualitatively, the response will be a change in the rooftop ratio of the neutron flux. The rooftop ratio may oscillate with high damping, or, instead, it may oscillate for many cycles. It has not been possible for them to determine this response by hand calculation because of the complexity of the problem, and yet it is important for them to be certain that high power operation will not lead us to inherently unstable operation. Therefore they have resorted to machine computation. The system of differential equations that describes the response has seven dependent variables; therefore there are seven equations, each coupled with one or more of the others. The authors have discussed the problem with R.R. Haefner at the plant, and it is his opinion that the IBM 650 cannot adequately handle the system of seven equations because the characteristic time constants vary over a range of about 10{sup 8}. The Univac located at the Louviers Building is said to be satisfactory for this computation.

  10. Preliminary Thermohydraulic Analysis of a New Moderated Reactor Utilizing an LEU-Fuel for Space Nuclear Thermal Propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Seung Hyun; Choi, Jae Young; Venneria, Paolo F.; Jeong, Yong Hoon; Chang, Soon Heung [KAIST, Daejeon (Korea, Republic of)

    2015-10-15

    The Korea Advanced NUclear Thermal Engine Rocket utilizing an LEU fuel (KANUTER-LEU) is a non-proliferative and comparably efficient NTR engine with relatively low thrust levels of 40 - 50 kN for in-space transportation. The small modular engine can expand mission versatility, when flexibly used in a clustered engine arrangement, so that it can perform various scale missions from low-thrust robotic science missions to high-thrust manned missions. In addition, the clustered engine system can enhance engine redundancy and ensuing crew safety as well as the thrust. The propulsion system is an energy conversion system to transform the thermal energy of the reactor into the kinetic energy of the propellant to produce the powers for thrust, propellant feeding and electricity. It is mainly made up of a propellant Feeding System (PFS) comprising a Turbo-Pump Assembly (TPA), a Regenerative Nozzle Assembly (RNA), etc. For this core design study, an expander cycle is assumed to be the propulsion system. The EGS converts the thermal energy of the EHTGR in the idle operation (only 350 kW{sub th} power) to electric power during the electric power mode. This paper presents a preliminary thermohydraulic design analysis to explore the design space for the new reactor and to estimate the referential engine performance. The new non-proliferative NTR engine concept, KANUTER-LEU, is under designing to surmount the nuclear proliferation obstacles on allR and Dactivities and eventual commercialization for future generations. To efficiently implement a heavy LEU fuel for the NTR engine, its reactor design innovatively possesses the key characteristics of the high U density fuel with high heating and H{sub 2} corrosion resistances, the thermal neutron spectrum core and also minimizing non-fission neutron loss, and the compact reactor design with protectively cooling capability. To investigate feasible design space for the moderated EHTGR-LEU and resultant engine performance, the

  11. Balance Ability and Proprioception after Single-Bundle, Single-Bundle Augmentation, and Double-Bundle ACL Reconstruction

    Directory of Open Access Journals (Sweden)

    Yubao Ma

    2014-01-01

    Full Text Available Purpose. The present study sought to determine the influences of single-bundle (SB, single-bundle augmentation (SBA, and double-bundle (DB reconstructions on balance ability and proprioceptive function. Methods. 67 patients who underwent a single- or double-bundle ACL reconstruction or a SBA using multistranded autologous hamstring tendons were included in this study with a 1-year follow-up. Body sway and knee kinesthesia (using the threshold to detect passive motion test (TTDPM were measured to indicate balance ability and proprioceptive function, respectively. Additionally, within-subject differences in anterior-posterior stability of the tibia and lower extremity muscle strength were evaluated before and after surgery. Results. At 6 and 12 months after surgery, DB reconstruction resulted in better balance and proprioceptive function than SB reconstruction (P<0.05. Although no significant difference was observed in balance ability or proprioceptive function between the SBA and DB reconstructions, knee stability was significantly better with SBA and DB reconstructions than SB reconstruction (P<0.05. No significant differences were found in quadriceps and hamstrings strength among the three reconstruction techniques. Conclusions. Our findings consider that joint stability, proprioceptive function, and balance ability were superior with SBA and DB reconstructions compared to SB reconstruction at 6 and 12 months after surgery.

  12. Transient tachypnea - newborn

    Science.gov (United States)

    TTN; Wet lungs - newborns; Retained fetal lung fluid; Transient RDS; Prolonged transition; Neonatal - transient tachypnea ... Newborns with transient tachypnea have breathing problems soon after birth, most often within 1 to 2 hours. ...

  13. Graph Bundling by Kernel Density Estimation

    NARCIS (Netherlands)

    Hurter, C.; Ersoy, O.; Telea, A.

    We present a fast and simple method to compute bundled layouts of general graphs. For this, we first transform a given graph drawing into a density map using kernel density estimation. Next, we apply an image sharpening technique which progressively merges local height maxima by moving the convolved

  14. Permanent His-Bundle Pacing: Case Studies.

    Science.gov (United States)

    Vijayaraman, Pugazhendhi; Dandamudi, Gopi

    2016-12-01

    His bundle pacing (HBP) is a physiological alternative to right ventricular pacing. In addition to patients with normal His-Purkinje conduction, HBP can be valuable in patients with infranodal atrioventricular (AV) block and patients undergoing AV node ablation. The following case studies illustrate the challenges associated with HBP. © 2016 Wiley Periodicals, Inc.

  15. Fluxes, bundle gerbes and 2-Hilbert spaces

    Science.gov (United States)

    Bunk, Severin; Szabo, Richard J.

    2017-10-01

    We elaborate on the construction of a prequantum 2-Hilbert space from a bundle gerbe over a 2-plectic manifold, providing the first steps in a programme of higher geometric quantisation of closed strings in flux compactifications and of M5-branes in C-fields. We review in detail the construction of the 2-category of bundle gerbes and introduce the higher geometrical structures necessary to turn their categories of sections into 2-Hilbert spaces. We work out several explicit examples of 2-Hilbert spaces in the context of closed strings and M5-branes on flat space. We also work out the prequantum 2-Hilbert space associated with an M-theory lift of closed strings described by an asymmetric cyclic orbifold of the SU(2) WZW model, providing an example of sections of a torsion gerbe on a curved background. We describe the dimensional reduction of M-theory to string theory in these settings as a map from 2-isomorphism classes of sections of bundle gerbes to sections of corresponding line bundles, which is compatible with the respective monoidal structures and module actions.

  16. The unintended consequences of bundled payments.

    Science.gov (United States)

    Weeks, William B; Rauh, Stephen S; Wadsworth, Eric B; Weinstein, James N

    2013-01-01

    Consensus is building that episode-based bundled payments can produce substantial Medicare savings, and the Center for Medicare & Medicaid Innovation's Bundled Payment Initiative endorses this concept. The program generates potential cost savings by reducing the historic cost of time-defined episodes of care, provided through a discount. Although bundled payments can reduce waste primarily in the postacute care setting, concerns arise that, in an effort to maintain income levels that are necessary to cover fixed costs, providers may change their behaviors to increase the volume of episodes. Such actions would mitigate the savings that Medicare might have accrued and may perpetuate the fee-for-service payment mechanism, with episodes of care becoming the new service. Although bundled payments have some advantages over the current reimbursement system, true cost-savings to Medicare will be realized only when the federal government addresses the use issue that underlies much of the waste inherent in the system and provides ample incentives to eliminate capacity and move toward capitation.

  17. Capacity efficiency of recovery request bundling

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Dittmann, Lars; Berger, Michael Stübert

    2010-01-01

    This paper presents a comparison of recovery methods in terms of capacity efficiency. In particular, a method where recovery requests are bundled towards the destination (Shortcut Span Protection) is evaluated against traditional recovery methods. Our simulation results show that Shortcut Span...

  18. Meromorphic connections on vector bundles over curves

    Indian Academy of Sciences (India)

    Descartes,. 67084 Strasbourg Cedex, France. *Correspond author. E-mail: indranil@math.tifr.res.in; heu@math.unistra.fr. MS received 17 July 2013; revised 20 October 2013. Abstract. We give a criterion for filtered vector bundles over curves to admit a ...

  19. Anterior cruciate ligament reconstruction with double bundle versus single bundle: experimental study

    National Research Council Canada - National Science Library

    Roberto F. Mota e Albuquerque; Sandra Umeda Sasaki; Marco Martins Amatuzzi; Fabio Janson Angelini

    2007-01-01

    OBJECTIVE: To test an intra-articular reconstruction of the anterior cruciate ligament of the knee in 10 human cadavers by replacing 2 anterior cruciate ligament bundles, with the purpose of producing...

  20. Functional aspects of His bundle physiology and pathophysiology: Clinical implications.

    Science.gov (United States)

    Scherlag, Benjamin J; Lazzara, Ralph

    In this review we present evidence from many experimental studies which challenge the concept of predestination of His bundle fibers. Using both intra- and extracellular His bundle pacing in the context of atrio-ventricular block and the development of bundle branch blocks these experimental studies provide the underlying mechanisms for the recent clinical findings showing the benefits of permanent His bundle pacing. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. A case of 'Masquerading' bundle branch block: a forgotten concept.

    Science.gov (United States)

    Choudhary, Dinesh; Namboodiri, Narayanan; Tharakan, Jaganmohan A

    2014-01-01

    'Masquerading' bundle branch block (right bundle branch block in the precordial leads with left bundle branch block in frontal leads and left axis deviation) is seen most commonly with coronary artery disease and hypertension. No definite explanation is available so far for these changes. We are presenting a case of rare congenital intranuclear inclusion myopathy with congestive heart failure and 'Masquerading' bundle branch block in ECG. Copyright © 2013 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  2. Bundling revisited: substitute products and inter-firm discounts

    OpenAIRE

    Armstrong, Mark

    2010-01-01

    This paper extends the standard model of bundling to allow products to be substitutes and for products to be supplied by separate sellers. Whether integrated or separate, firms have an incentive to introduce bundling discounts when demand for the bundle is elastic relative to demand for stand-alone products. When products are partial substitutes, this typically gives an integrated firm a greater incentive to offer a bundle discount (relative to the standard model with additive preferences), w...

  3. Compactifications of reductive groups as moduli stacks of bundles

    DEFF Research Database (Denmark)

    Martens, Johan; Thaddeus, Michael

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

  4. Turkish and Native English Academic Writers' Use of Lexical Bundles

    Science.gov (United States)

    Öztürk, Yusuf; Köse, Gül Durmusoglu

    2016-01-01

    Lexical bundles such as "on the other hand" and "as a result of" are extremely common and important in academic discourse. The appropriate use of lexical bundles typical of a specific academic discipline is important for writers and the absence of such bundles may not sound fluent and native-like. Recent studies (e.g. Adel…

  5. Quillen bundle and geometric prequantization of non-abelian ...

    Indian Academy of Sciences (India)

    In this paper we prequantize the moduli space of non-abelian vortices. We explicitly calculate the symplectic form arising from 2 metric and we construct a prequantum line bundle whose curvature is proportional to this symplectic form. The prequantum line bundle turns out to be Quillen's determinant line bundle with a ...

  6. The Bundle of His in Prosthetic Heart Valve Replacement*

    African Journals Online (AJOL)

    1973-01-27

    Jan 27, 1973 ... ventricular seplUm which transected the bundle of His. Blocks were then fashioned backwards and forwards.. to include the whole of the bundle and the AV node. as well as the bifurcation of the bundle into its left and right branches. According to Davies: in order to study the whole conduction system in an ...

  7. Real parabolic vector bundles over a real curve

    Indian Academy of Sciences (India)

    weights are integral multiples of 1/N, and the category of real -equivariant vector bundles on (Y,σY ). ... The notion of parabolic vector bundles over a compact Riemann surface was introduced by Seshadri [4] and their .... stable. If F is a direct sum of stable vector bundles having the same slope, then F is called polystable.

  8. Geometry of torus bundles in integrable Hamiltonian systems

    NARCIS (Netherlands)

    Lukina, Olga

    2008-01-01

    Thesis is concerned with global properties of Lagrangian bundles, i.e. symplectic n-torus bundles, as these occur in integrable Hamiltonian systems. It treats obstructions to triviality and concerns with classification of such bundles, as well as with manifestations of global invariants in

  9. Experimental investigation of effect of flow attack angle on thermohydraulic performance of air flow in a rectangular channel with discrete V-pattern baffle on the heated plate

    Directory of Open Access Journals (Sweden)

    Raj Kumar

    2016-05-01

    Full Text Available In this work, the effect of angle of attack ( α a of the discrete V-pattern baffle on thermohydraulic performance of rectangular channel has been studied experimentally. The baffle wall was constantly heated and the other three walls of the channel were kept insulated. The experimentations were conducted to collect the data on Nusselt number ( N u b and friction factor ( f b by varying the Reynolds number (Re = 3000–21,000 and angle of attack ( α a from 30° to 70°, for the kept values of relative baffle height ( H b / H = 0 . 50 , relative pitch ratio ( P b / H = 1 . 0 , relative discrete width ( g w / H b = 1 . 5 and relative discrete distance ( D d / L v = 0 . 67 . As compared to the smooth wall, the V-pattern baffle roughened channel enhances the Nusselt number ( N u b and friction factor ( f b by 4.2 and 5.9 times, respectively. The present discrete V-pattern baffle shapes with angle of attack ( α a of 60° equivalent to flow Reynolds number of 3000 yields the greatest thermohydraulic performance. Discrete V-pattern baffle has improved thermal performance as compared to other baffle shapes’ rectangular channel.

  10. Study on in-vessel thermohydraulics phenomena of sodium-cooled fast reactors. 2. Numerical investigations on proprieties of R/V upper plenum separation

    Energy Technology Data Exchange (ETDEWEB)

    Muramatsu, Toshiharu; Yamaguchi, Akira [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center; Murakami, Satoshi [Customer System Co. Ltd., Tokai, Ibaraki (Japan)

    2002-03-01

    A large-scale sodium-cooled fast breeder reactor investigated in the feasibility studies on commercialized fast reactors has a tendency of consideration of thorough simplified and compacted system designs to realize drastic economical improvements. Therefore, special attention should be paid to thermohydraulic designs for gas entrainment behavior from free surfaces, a flow-induced vibration of in-vessel components, thermal shock for various structures due to high-speed coolant flows, nonsymmetrical coolant flows, etc. in the reactor vessel. In-vessel thermohydraulic analyses were carried out using a multi-dimensional code AQUA to contribute to a planning of water scaled-model experiments for the separated upper plena of the reactor vessel. >From the analysis, the following results were obtained. (1) It can be considered that there is little effect of volumetric flow rate between the upper plenum and the free surface plenum on hydrodynamic characteristics in the whole upper plenum. Because the affected area is limited in the neighborhood of gaps of hot/cold leg pipes. (2) Change in flow velocity components is limited around the outer wall of hot leg pipes if the gap width of the dipped plate and penetrating components changes. From the above results, it was concluded that the assumption seems to be valid that the free surface plenum hydrodynamic characteristics is independent of the upper plenum flows. However it is necessary to consider jet effects due to the hot leg intake flows affecting vortex concentrations in the upper plenum. (author)

  11. Masquerading bundle branch block: a variety of right bundle branch block with left anterior fascicular block.

    Science.gov (United States)

    Elizari, Marcelo V; Baranchuk, Adrian; Chiale, Pablo A

    2013-01-01

    The so-called 'masquerading' type of right bundle branch block is caused by the simultaneous presence of a high-degree left anterior fascicular block often accompanied with severe left ventricular enlargement and/or fibrotic block in the anterolateral wall of the left ventricle. These conditions tend to reorient the terminal electrical forces of the QRS complex towards the left and upwards, in such a way that the characteristic slurred S wave in lead I becomes smaller or even disappears. In many cases of standard masquerading right bundle branch block, a small Q wave in lead I is present due to the initial forces of the left anterior fascicular block, which are oriented rightwards and inferiorly. However, in some cases, the Q wave in lead I also vanishes, and the mimicking of a left bundle branch block becomes perfect in standard leads. This is commonly associated with an inferior myocardial infarction or severe inferior fibrosis in cardiomyopathies. The typical QRS changes of right bundle branch block may eventually be concealed even in the right precordial leads; under such circumstances, the ECG diagnosis may be mistaken and the right bundle branch block totally missed. The masquerading right bundle branch block carries a poor prognosis, since it always implies the presence of a severe underlying heart disease.

  12. Bundling of harvesting residues and whole-trees and the treatment of bundles; Hakkuutaehteiden ja kokopuiden niputus ja nippujen kaesittely

    Energy Technology Data Exchange (ETDEWEB)

    Kaipainen, H.; Seppaenen, V.; Rinne, S.

    1996-12-31

    The conditions on which the bundling of the harvesting residues from spruce regeneration fellings would become profitable were studied. The calculations showed that one of the most important features was sufficient compaction of the bundle, so that the portion of the wood in the unit volume of the bundle has to be more than 40 %. The tests showed that the timber grab loader of farm tractor was insufficient for production of dense bundles. The feeding and compression device of the prototype bundler was constructed in the research and with this device the required density was obtained.The rate of compaction of the dry spruce felling residues was about 40 % and that of the fresh residues was more than 50 %. The comparison between the bundles showed that the calorific value of the fresh bundle per unit volume was nearly 30 % higher than that of the dry bundle. This means that the treatment of the bundles should be done of fresh felling residues. Drying of the bundles succeeded well, and the crushing and chipping tests showed that the processing of the bundles at the plant is possible. The treatability of the bundles was also excellent. By using the prototype, developed in the research, it was possible to produce a bundle of the fresh spruce harvesting residues, the diameter of which was about 50 cm and the length about 3 m, and the rate of compaction over 50 %. By these values the reduction target of the costs is obtainable

  13. Combining QOF data with the care bundle approach may provide a more meaningful measure of quality in general practice

    Directory of Open Access Journals (Sweden)

    de Wet Carl

    2012-10-01

    Full Text Available Abstract Background A significant minority of patients do not receive all the evidence-based care recommended for their conditions. Health care quality may be improved by reducing this observed variation. Composite measures offer a different patient-centred perspective on quality and are utilized in acute hospitals via the ‘care bundle’ concept as indicators of the reliability of specific (evidence-based care delivery tasks and improved outcomes. A care bundle consists of a number of time-specific interventions that should be delivered to every patient every time. We aimed to apply the care bundle concept to selected QOF data to measure the quality of evidence-based care provision. Methods Care bundles and components were selected from QOF indicators according to defined criteria. Five clinical conditions were suitable for care bundles: Secondary Prevention of Coronary Heart Disease (CHD, Stroke & Transient Ischaemic Attack (TIA, Chronic Kidney Disease (CKD, Chronic Obstructive Pulmonary Disease (COPD and Diabetes Mellitus (DM. Each bundle has 3-8 components. A retrospective audit was undertaken in a convenience sample of nine general medical practices in the West of Scotland. Collected data included delivery (or not of individual bundle components to all patients included on specific disease registers. Practice level and overall compliance with bundles and components were calculated in SPSS and expressed as a percentage. Results Nine practices (64.3% with a combined patient population of 56,948 were able to provide data in the format requested. Overall compliance with developed QOF-based care bundles (composite measures was as follows: CHD 64.0%, range 35.0-71.9%; Stroke/TIA 74.1%, range 51.6-82.8%; CKD 69.0%, range 64.0-81.4%; and COPD 82.0%, range 47.9-95.8%; and DM 58.4%, range 50.3-65.2%. Conclusions In this small study compliance with individual QOF-based care bundle components was high, but overall (‘all or nothing’ compliance was

  14. Baseline left bundle branch block with right bundle branch escape complexes in a patient with coronary artery disease, presents like an alternating bundle branch block: a case report

    Science.gov (United States)

    Bhimaraj, Arvind; Abusin, Salaheldin; Margeta, Bosko

    2008-01-01

    Alternating bundle branch block (ABBB) is a less commonly encountered phenomenon with the advent of re-perfusion therapy for acute myocardial infarction. ECGs simulating the appearance of an ABBB need to be carefully analysed. We present an ECG showing a baseline Left Bundle Branch Block(LBBB) progressing to a high grade AV block with escape complexes having a Right Bundle Branch Block (RBBB) morphology. Such an ECG can be mistaken for an ABBB if not analysed carefully. PMID:19116014

  15. Non-abelian higher gauge theory and categorical bundle

    Science.gov (United States)

    Viennot, David

    2016-12-01

    A gauge theory is associated with a principal bundle endowed with a connection permitting to define horizontal lifts of paths. The horizontal lifts of surfaces cannot be defined into a principal bundle structure. An higher gauge theory is an attempt to generalize the bundle structure in order to describe horizontal lifts of surfaces. A such attempt is particularly difficult for the non-abelian case. Some structures have been proposed to realize this goal (twisted bundle, gerbes with connection, bundle gerbe, 2-bundle). Each of them uses a category in place of the total space manifold of the usual principal bundle structure. Some of them replace also the structure group by a category (more precisely a Lie crossed module viewed as a category). But the base space remains still a simple manifold (possibly viewed as a trivial category with only identity arrows). We propose a new principal categorical bundle structure, with a Lie crossed module as structure groupoid, but with a base space belonging to a bigger class of categories (which includes non-trivial categories), that we called affine 2-spaces. We study the geometric structure of the categorical bundles built on these categories (which are a more complicated structure than the 2-bundles) and the connective structures on these bundles. Finally we treat an example interesting for quantum dynamics which is associated with the Bloch wave operator theory.

  16. Current interruption transients calculation

    CERN Document Server

    Peelo, David F

    2014-01-01

    Provides an original, detailed and practical description of current interruption transients, origins, and the circuits involved, and how they can be calculated Current Interruption Transients Calculationis a comprehensive resource for the understanding, calculation and analysis of the transient recovery voltages (TRVs) and related re-ignition or re-striking transients associated with fault current interruption and the switching of inductive and capacitive load currents in circuits. This book provides an original, detailed and practical description of current interruption transients, origins,

  17. SIKAP KONSUMEN TERHADAP PRODUK BUNDLING AGRIBISNIS

    Directory of Open Access Journals (Sweden)

    Didi Junaedi

    2017-04-01

    implementation to Dekalb brand hybrid corn and Round-up brand herbicide. By analyzes how consumer attitudes toward buying intention in this regard farmers as buyer and retailers as products services. The data used is primary data. Primary data is obtained using 2 kind of respondents are retailers and farmers. The data obtained by distributed 30 questionnaires for retailers and 110 farmers in Grobogan. The descriptive statistic employed to analyzed data by using multiple linear regressions with t test, F test and coefficient of determination. The result showed that on retailers respondents attribute the product bundling has no significant influence to consumer buying intention but consumer attitudes significantly influence the buying intention. On the farmers respondents showed that attributes of the product bundling and consumer attitudes positive and significant influence to buying intention.

  18. Covariance and the hierarchy of frame bundles

    Science.gov (United States)

    Estabrook, Frank B.

    1987-01-01

    This is an essay on the general concept of covariance, and its connection with the structure of the nested set of higher frame bundles over a differentiable manifold. Examples of covariant geometric objects include not only linear tensor fields, densities and forms, but affinity fields, sectors and sector forms, higher order frame fields, etc., often having nonlinear transformation rules and Lie derivatives. The intrinsic, or invariant, sets of forms that arise on frame bundles satisfy the graded Cartan-Maurer structure equations of an infinite Lie algebra. Reduction of these gives invariant structure equations for Lie pseudogroups, and for G-structures of various orders. Some new results are introduced for prolongation of structure equations, and for treatment of Riemannian geometry with higher-order moving frames. The use of invariant form equations for nonlinear field physics is implicitly advocated.

  19. Client Provider Collaboration for Service Bundling

    Directory of Open Access Journals (Sweden)

    LETIA, I. A.

    2008-04-01

    Full Text Available The key requirement for a service industry organization to reach competitive advantages through product diversification is the existence of a well defined method for building service bundles. Based on the idea that the quality of a service or its value is given by the difference between expectations and perceptions, we draw the main components of a frame that aims to support the client and the provider agent in an active collaboration meant to co-create service bundles. Following e3-value model, we structure the supporting knowledge around the relation between needs and satisfying services. We deal with different perspectives about quality through an ontological extension of Value Based Argumentation. The dialog between the client and the provider takes the form of a persuasion whose dynamic object is the current best configuration. Our approach for building service packages is a demand driven approach, allowing progressive disclosure of private knowledge.

  20. Uncovering Ecosystem Service Bundles through Social Preferences

    Science.gov (United States)

    Martín-López, Berta; Iniesta-Arandia, Irene; García-Llorente, Marina; Palomo, Ignacio; Casado-Arzuaga, Izaskun; Amo, David García Del; Gómez-Baggethun, Erik; Oteros-Rozas, Elisa; Palacios-Agundez, Igone; Willaarts, Bárbara; González, José A.; Santos-Martín, Fernando; Onaindia, Miren; López-Santiago, Cesar; Montes, Carlos

    2012-01-01

    Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension of ecosystem services, despite being considered a research priority. We examined how ecosystem service bundles and trade-offs emerge from diverging social preferences toward ecosystem services delivered by various types of ecosystems in Spain. We conducted 3,379 direct face-to-face questionnaires in eight different case study sites from 2007 to 2011. Overall, 90.5% of the sampled population recognized the ecosystem’s capacity to deliver services. Formal studies, environmental behavior, and gender variables influenced the probability of people recognizing the ecosystem’s capacity to provide services. The ecosystem services most frequently perceived by people were regulating services; of those, air purification held the greatest importance. However, statistical analysis showed that socio-cultural factors and the conservation management strategy of ecosystems (i.e., National Park, Natural Park, or a non-protected area) have an effect on social preferences toward ecosystem services. Ecosystem service trade-offs and bundles were identified by analyzing social preferences through multivariate analysis (redundancy analysis and hierarchical cluster analysis). We found a clear trade-off among provisioning services (and recreational hunting) versus regulating services and almost all cultural services. We identified three ecosystem service bundles associated with the conservation management strategy and the rural-urban gradient. We conclude that socio-cultural preferences toward ecosystem services can serve as a tool to identify relevant services for people, the factors underlying these social preferences, and emerging ecosystem service bundles and trade-offs. PMID:22720006

  1. Twisted vector bundles on pointed nodal curves

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    DEFINITION 2.5. Let C → S be an n-pointed nodal curve over a k-scheme S and let ξ be a principal G- bundle on Cgen. A chart (U, η, ) for ξ is called balanced, if for each ... branches is via multiplication with primitive roots of unity which are inverse to each other. ...... Condition (16) implies that A0 is a block matrix of the form.

  2. Principal bundles on the projective line

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    LetX be a complete nonsingular curve over the algebraic closurek ofk andGa reductive group over k. Let E → X be a principal G-bundle on X. E is said to be semistable if, for every reduction of structure group EP ⊂ E to a maximal parabolic subgroup P of G, we have degree EP (p) ≤ 0, where p is the Lie algebra of P and EP ...

  3. Abelian conformal field theory and determinant bundles

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard; Ueno, K.

    2007-01-01

    are up to a scale the same as the curvature of the connections constructed in [14, 16]. We study the sewing construction for nodal curves and its explicit relation to the constructed connections. Finally we construct preferred holomorphic sections of these line bundles and analyze their behaviour near...... nodal curves. These results are used in [4] to construct modular functors form the conformal field theories given in [14, 16] by twisting with an appropriate factional power of this Abelian theory....

  4. Uncovering ecosystem service bundles through social preferences.

    Directory of Open Access Journals (Sweden)

    Berta Martín-López

    Full Text Available Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension of ecosystem services, despite being considered a research priority. We examined how ecosystem service bundles and trade-offs emerge from diverging social preferences toward ecosystem services delivered by various types of ecosystems in Spain. We conducted 3,379 direct face-to-face questionnaires in eight different case study sites from 2007 to 2011. Overall, 90.5% of the sampled population recognized the ecosystem's capacity to deliver services. Formal studies, environmental behavior, and gender variables influenced the probability of people recognizing the ecosystem's capacity to provide services. The ecosystem services most frequently perceived by people were regulating services; of those, air purification held the greatest importance. However, statistical analysis showed that socio-cultural factors and the conservation management strategy of ecosystems (i.e., National Park, Natural Park, or a non-protected area have an effect on social preferences toward ecosystem services. Ecosystem service trade-offs and bundles were identified by analyzing social preferences through multivariate analysis (redundancy analysis and hierarchical cluster analysis. We found a clear trade-off among provisioning services (and recreational hunting versus regulating services and almost all cultural services. We identified three ecosystem service bundles associated with the conservation management strategy and the rural-urban gradient. We conclude that socio-cultural preferences toward ecosystem services can serve as a tool to identify relevant services for people, the factors underlying these social preferences, and emerging ecosystem service bundles and trade-offs.

  5. Uncovering ecosystem service bundles through social preferences.

    Science.gov (United States)

    Martín-López, Berta; Iniesta-Arandia, Irene; García-Llorente, Marina; Palomo, Ignacio; Casado-Arzuaga, Izaskun; Amo, David García Del; Gómez-Baggethun, Erik; Oteros-Rozas, Elisa; Palacios-Agundez, Igone; Willaarts, Bárbara; González, José A; Santos-Martín, Fernando; Onaindia, Miren; López-Santiago, Cesar; Montes, Carlos

    2012-01-01

    Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension of ecosystem services, despite being considered a research priority. We examined how ecosystem service bundles and trade-offs emerge from diverging social preferences toward ecosystem services delivered by various types of ecosystems in Spain. We conducted 3,379 direct face-to-face questionnaires in eight different case study sites from 2007 to 2011. Overall, 90.5% of the sampled population recognized the ecosystem's capacity to deliver services. Formal studies, environmental behavior, and gender variables influenced the probability of people recognizing the ecosystem's capacity to provide services. The ecosystem services most frequently perceived by people were regulating services; of those, air purification held the greatest importance. However, statistical analysis showed that socio-cultural factors and the conservation management strategy of ecosystems (i.e., National Park, Natural Park, or a non-protected area) have an effect on social preferences toward ecosystem services. Ecosystem service trade-offs and bundles were identified by analyzing social preferences through multivariate analysis (redundancy analysis and hierarchical cluster analysis). We found a clear trade-off among provisioning services (and recreational hunting) versus regulating services and almost all cultural services. We identified three ecosystem service bundles associated with the conservation management strategy and the rural-urban gradient. We conclude that socio-cultural preferences toward ecosystem services can serve as a tool to identify relevant services for people, the factors underlying these social preferences, and emerging ecosystem service bundles and trade-offs.

  6. Bundling harvester; Harvennuspuun automaattisen nippukorjausharvesterin kehittaeminen

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, K. [Eko-Log Oy, Kuopio (Finland)

    1997-12-01

    The starting point of the project was to design and construct, by taking the silvicultural point of view into account, a harvesting and processing system especially for energy-wood, containing manually driven bundling harvester, automating of the harvester, and automated loading. The equipment forms an ideal method for entrepreneur`s-line harvesting. The target is to apply the system also for owner`s-line harvesting. The profitability of the system promotes the utilisation of the system in both cases. The objectives of the project were: to construct a test equipment and prototypes for all the project stages, to carry out terrain and strain tests in order to examine the usability and durability, as well as the capacity of the machine, to test the applicability of the Eko-Log system in simultaneous harvesting of energy and pulp woods, and to start the marketing and manufacturing of the products. The basic problems of the construction of the bundling harvester have been solved using terrain-tests. The prototype machine has been shown to be operable. Loading of the bundles to form sufficiently economically transportable loads has been studied, and simultaneously, the branch-biomass has been tried to be utilised without loosing the profitability of transportation. The results have been promising, and will promote the profitable utilisation of wood-energy. (orig.)

  7. An analytical fiber bundle model for pullout mechanics of root bundles

    Science.gov (United States)

    Cohen, D.; Schwarz, M.; Or, D.

    2011-09-01

    Roots in soil contribute to the mechanical stability of slopes. Estimation of root reinforcement is challenging because roots form complex biological networks whose geometrical and mechanical characteristics are difficult to characterize. Here we describe an analytical model that builds on simple root descriptors to estimate root reinforcement. Root bundles are modeled as bundles of heterogeneous fibers pulled along their long axes neglecting root-soil friction. Analytical expressions for the pullout force as a function of displacement are derived. The maximum pullout force and corresponding critical displacement are either derived analytically or computed numerically. Key model inputs are a root diameter distribution (uniform, Weibull, or lognormal) and three empirical power law relations describing tensile strength, elastic modulus, and length of roots as functions of root diameter. When a root bundle with root tips anchored in the soil matrix is pulled by a rigid plate, a unique parameter, ?, that depends only on the exponents of the power law relations, dictates the order in which roots of different diameters break. If ? 1, large roots break first. When ? = 1, all fibers break simultaneously, and the maximum tensile force is simply the roots' mean force times the number of roots in the bundle. Based on measurements of root geometry and mechanical properties, the value of ? is less than 1, usually ranging between 0 and 0.7. Thus, small roots always fail first. The model shows how geometrical and mechanical characteristics of roots and root diameter distribution affect the pullout force, its maximum and corresponding displacement. Comparing bundles of roots that have similar mean diameters, a bundle with a narrow variance in root diameter will result in a larger maximum force and a smaller displacement at maximum force than a bundle with a wide diameter distribution. Increasing the mean root diameter of a bundle without changing the distribution's shape increases

  8. Study on in-vessel thermohydraulics phenomena of sodium-cooled fast reactors. 1. Numerical investigation for the rationalization of hydrodynamics in the upper plenum

    Energy Technology Data Exchange (ETDEWEB)

    Muramatsu, Toshiharu; Yamaguchi, Akira [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center; Murakami, Satoshi [Customer System Co.Ltd. (Japan)

    2002-02-01

    A large-scale sodium-cooled fast breeder reactor in feasibility studies on commercialized fast reactors has a tendency of consideration of thorough simplified and compacted system designs to realize drastic economical improvements. Therefore, special attention should be paid to thermohydraulic designs for a gas entrainment behavior from free surfaces, a flow-induced vibration of in-vessel components, a thermal shock for various structures due to high-speed coolant flows, nonsymmetrical coolant flows, etc. in the reactor vessel. In-vessel thermohydraulic analyses were carried out using a multi-dimensional code AQUA to understand the thermohydraulic characteristics in the upper plenum, and to investigate suitable in-vessel structure for the elimination of gas entrainment possibility. From the analysis, the following results were obtained. (1) It is difficult to rationale in-vessel flow patterns through adjustments of porous ratio and pressure loss for a hold down plate and baffle plates installed in an upper core structure. (2) Dummy plug insertion to a slit of the upper core structure is one of effective measures to stabilize in-vessel flow patterns. (3) Flow guide devices such as a baffle ring and a partial inner barrel are also effective measures to eliminate impinging jet to a dipped plate (D/P) and to reduce horizontal flow velocity components at free surface. (4) Installations of labyrinth structures to a R/V - D/P gap is successful for decreasing of free surface horizontal flows. (5) Gap closing of an in-vessel fuel pot and two cold trap components has the effects of reductions for free surface horizontal flows and for the difference of free surface levels. Following future investigations are important preventive measures against the gas entrainment from the free surface. (1) Flattening of spatial axial velocity distributions at the R/V - D/P gap. (2) Alleviation measures of vortex concentration at free surface. (3) Separation measures of 3-dimensional vortex

  9. COBRA-IV-I: an interim version of COBRA for thermal-hydraulic analysis of rod bundle nuclear fuel elements and cores

    Energy Technology Data Exchange (ETDEWEB)

    Wheeler, C.L.; Stewart, C.W.; Cena, R.J.; Rowe, D.S.; Sutey, A.M.

    1976-03-01

    The COBRA-IV-I computer code uses the subchannel analysis approach to determine the enthalpy and flow distribution in rod bundles for both steady-state and transient conditions. The steady-state and transient solution schemes used in COBRA-IIIC are still available in COBRA-IV-I as the implicit solution scheme option. In addition to these techniques, a new explicit solution scheme is now available which allows the calculation of severe transients involving flow reversals, recirculations, expulsion and reentry flows, with a pressure or flow boundary condition specified. Significant storage compaction and reduced running times have been achieved to allow the calculation of problems involving hundreds of subchannels.

  10. Thermohydraulics of a horizontal diphasic flow of superfluid helium; Thermo-hydraulique d'un ecoulement horizontal d'helium superfluide diphasique

    Energy Technology Data Exchange (ETDEWEB)

    Perraud, S

    2007-12-15

    This study aims at characterizing helium two phase flows, and to identify the dependence of their characteristics on various thermo-hydraulic parameters: vapour velocity, liquid height, vapour density, specificities of superfluidity. Both the engineer and the physicist's points of view are taken into consideration: the first one in terms of optimization of a particular cooling scheme based on a two-phase flow, and these second one in terms of more fundamental atomization-related questions. It has been shown that for velocities around 3 to 4 m/s, the liquid phase that was initially stratified undergoes an atomization through the presence of a drop haze carried by the vapor phase.This happens for superfluid helium as well as for normal helium without main differences on atomization.

  11. Influence of Bundle Diameter and Attachment Point on Kinematic Behavior in Double Bundle Anterior Cruciate Ligament Reconstruction Using Computational Model

    Directory of Open Access Journals (Sweden)

    Oh Soo Kwon

    2014-01-01

    Full Text Available A protocol to choose the graft diameter attachment point of each bundle has not yet been determined since they are usually dependent on a surgeon’s preference. Therefore, the influence of bundle diameters and attachment points on the kinematics of the knee joint needs to be quantitatively analyzed. A three-dimensional knee model was reconstructed with computed tomography images of a 26-year-old man. Based on the model, models of double bundle anterior cruciate ligament (ACL reconstruction were developed. The anterior tibial translations for the anterior drawer test and the internal tibial rotation for the pivot shift test were investigated according to variation of bundle diameters and attachment points. For the model in this study, the knee kinematics after the double bundle ACL reconstruction were dependent on the attachment point and not much influenced by the bundle diameter although larger sized anterior-medial bundles provided increased stability in the knee joint. Therefore, in the clinical setting, the bundle attachment point needs to be considered prior to the bundle diameter, and the current selection method of graft diameters for both bundles appears justified.

  12. The InterFrost benchmark of Thermo-Hydraulic codes for cold regions hydrology - first inter-comparison results

    Science.gov (United States)

    Grenier, Christophe; Roux, Nicolas; Anbergen, Hauke; Collier, Nathaniel; Costard, Francois; Ferrry, Michel; Frampton, Andrew; Frederick, Jennifer; Holmen, Johan; Jost, Anne; Kokh, Samuel; Kurylyk, Barret; McKenzie, Jeffrey; Molson, John; Orgogozo, Laurent; Rivière, Agnès; Rühaak, Wolfram; Selroos, Jan-Olof; Therrien, René; Vidstrand, Patrik

    2015-04-01

    The impacts of climate change in boreal regions has received considerable attention recently due to the warming trends that have been experienced in recent decades and are expected to intensify in the future. Large portions of these regions, corresponding to permafrost areas, are covered by water bodies (lakes, rivers) that interact with the surrounding permafrost. For example, the thermal state of the surrounding soil influences the energy and water budget of the surface water bodies. Also, these water bodies generate taliks (unfrozen zones below) that disturb the thermal regimes of permafrost and may play a key role in the context of climate change. Recent field studies and modeling exercises indicate that a fully coupled 2D or 3D Thermo-Hydraulic (TH) approach is required to understand and model the past and future evolution of landscapes, rivers, lakes and associated groundwater systems in a changing climate. However, there is presently a paucity of 3D numerical studies of permafrost thaw and associated hydrological changes, and the lack of study can be partly attributed to the difficulty in verifying multi-dimensional results produced by numerical models. Numerical approaches can only be validated against analytical solutions for a purely thermic 1D equation with phase change (e.g. Neumann, Lunardini). When it comes to the coupled TH system (coupling two highly non-linear equations), the only possible approach is to compare the results from different codes to provided test cases and/or to have controlled experiments for validation. Such inter-code comparisons can propel discussions to try to improve code performances. A benchmark exercise was initialized in 2014 with a kick-off meeting in Paris in November. Participants from USA, Canada, Germany, Sweden and France convened, representing altogether 13 simulation codes. The benchmark exercises consist of several test cases inspired by existing literature (e.g. McKenzie et al., 2007) as well as new ones. They

  13. Modifications in Compacted MX-80 Bentonite Due to Thermo-Hydraulic Treatment; Modificaciones en la Bentonita MX-80 Compactada Sometida a Tratamiento Termo-Hidraulico

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Espina, R.; Villar, M. V.

    2013-09-01

    The thermo-hydraulic tests reproduce the thermal and hydraulic conditions to which bentonite is subjected in the engineered barrier of a deep geological repository of radioactive waste. The results of thermo-hydraulic test TBT1500, which was running for approximately 1500 days, are presented. This is a continuation to the Technical Report Ciemat 1199, which presented results of test TBT500, performed under similar conditions but with duration of 500 days. In both tests the MX-80 bentonite was used with initial density and water content similar to those of the large-scale test TBT. The bentonite column was heated at the bottom at 140 degree centigrade and hydrated on top with deionized water. At the end of the test a sharp water content gradient was observed along the column, as well as an inverse dry density gradient. Hydration modified also the bentonite microstructure. Besides, an overall decrease of the smectite content with respect to the initial value took place, especially in the most hydrated areas where the percentage of interest ratified illite increased and in the longer test. On the other hand, the content of cristobalite, feldspars and calcite increased. Smectite dissolution processes (probably colloidal) occurred, particularly in the more hydrated areas and in the longer test. Due to the dissolution of low-solubility species and to the loss of exchangeable positions in the smectite, the content of soluble salts in the pore water increased with respect to the original one, especially in the longer test. The solubilized ions were transported; sodium, calcium, magnesium and sulphate having a similar mobility, which was in turn lower than that of potassium and chloride. The cationic exchange complex was also modified. (Author)

  14. Study on in-vessel thermohydraulics phenomena of sodium-cooled fast reactors. 3. Numerical investigation for thermal stratification phenomena in the upper plenum

    Energy Technology Data Exchange (ETDEWEB)

    Muramatsu, Toshiharu; Yamaguchi, Akira [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center; Wakita, Junichi [Customer System Co. Ltd. (Japan)

    2002-06-01

    A large-scale sodium-cooled fast breeder reactor in the feasibility studies on commercialized fast reactors has a feature of consideration of thorough simplified and compacted systems and components design to realize drastic economical improvements. Therefore, special attentions should be paid to thermohydraulic designs for gas entrainment behavior from free surface, flow-induced vibration of in-vessel components, thermal stratification in the plenum, thermal shock for various structures due to high-speed coolant flows, nonsymmetrical coolant flows, etc. in the reactor vessel. In-vessel thermohydraulic analyses were carried out using a multi-dimensional code AQUA to understand the thermal stratification characteristics in the upper plenum, and to investigate trade-off relations between gas entrainment and thermal stratification phenomena on in-vessel structures for the elimination of gas entrainment possibility. From the analysis, the following results were obtained. (1) Dummy plug insertion to a slit of the upper core structure is one of the effective measures to stabilize the in-vessel flow patterns and to mitigate in-vessel thermal shocks. (2) Though flow guide device such as a baffle ring attached to reactor vessel wall is an effective measure to eliminate impinging jet to dipped plate, rising characteristics of the thermal stratification interface are affected by the baffle ring devise. (3) Thermal stratification characteristics are not influenced very much by the installation of a partial inner barrel to the dipped plate, which is an effective measure to reduce the horizontal flow velocity components at free surface. (4) Labyrinth structures to the gap between the reactor vessel wall and the outer dipped plate have direct effects upon in-vessel thermal shock characteristics including thermal stratification phenomena due to the closing of flow path between the upper plenum and the free surface plenum. (author)

  15. Transient Global Amnesia

    Science.gov (United States)

    ... sudden memory loss. Request an Appointment at Mayo Clinic Causes The underlying cause of transient global amnesia is unknown. There appears to be a link between transient global amnesia and a history of migraines, though the underlying factors that contribute ...

  16. Monopoles and Modifications of Bundles over Elliptic Curves

    Directory of Open Access Journals (Sweden)

    Andrey M. Levin

    2009-06-01

    Full Text Available Modifications of bundles over complex curves is an operation that allows one to construct a new bundle from a given one. Modifications can change a topological type of bundle. We describe the topological type in terms of the characteristic classes of the bundle. Being applied to the Higgs bundles modifications establish an equivalence between different classical integrable systems. Following Kapustin and Witten we define the modifications in terms of monopole solutions of the Bogomolny equation. We find the Dirac monopole solution in the case R × (elliptic curve. This solution is a three-dimensional generalization of the Kronecker series. We give two representations for this solution and derive a functional equation for it generalizing the Kronecker results. We use it to define Abelian modifications for bundles of arbitrary rank. We also describe non-Abelian modifications in terms of theta-functions with characteristic.

  17. Trivalent Cation Induced Bundle Formation of Filamentous fd Phages.

    Science.gov (United States)

    Korkmaz Zirpel, Nuriye; Park, Eun Jin

    2015-09-01

    Bacteriophages are filamentous polyelectrolyte viral rods infecting only bacteria. In this study, we investigate the bundle formation of fd phages with trivalent cations having different ionic radii (Al(3+) , La(3+) and Y(3+) ) at various phage and counterion concentrations, and at varying bundling times. Aggregated phage bundles were detected at relatively low trivalent counterion concentrations (1 mM). Although 10 mM and 100 mM Y(3+) and La(3+) treatments formed larger and more intertwined phage bundles, Al(3+) and Fe(3+) treatments lead to the formation of networking filaments. Energy dispersive X-ray spectroscopy (EDX) analyses confirmed the presence of C, N and O peaks on densely packed phage bundles. Immunofluorescence labelling and ELISA analyses with anti-p8 antibodies showed the presence of phage filaments after bundling. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Transient drainage summary report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    This report summarizes the history of transient drainage issues on the Uranium Mill Tailings Remedial Action (UMTRA) Project. It defines and describes the UMTRA Project disposal cell transient drainage process and chronicles UMTRA Project treatment of the transient drainage phenomenon. Section 4.0 includes a conceptual cross section of each UMTRA Project disposal site and summarizes design and construction information, the ground water protection strategy, and the potential for transient drainage.

  19. Heat Transfer Analysis in Wire Bundles for Aerospace Vehicles

    Science.gov (United States)

    Rickman, S. L.; Iamello, C. J.

    2016-01-01

    Design of wiring for aerospace vehicles relies on an understanding of "ampacity" which refers to the current carrying capacity of wires, either, individually or in wire bundles. Designers rely on standards to derate allowable current flow to prevent exceedance of wire temperature limits due to resistive heat dissipation within the wires or wire bundles. These standards often add considerable margin and are based on empirical data. Commercial providers are taking an aggressive approach to wire sizing which challenges the conventional wisdom of the established standards. Thermal modelling of wire bundles may offer significant mass reduction in a system if the technique can be generalized to produce reliable temperature predictions for arbitrary bundle configurations. Thermal analysis has been applied to the problem of wire bundles wherein any or all of the wires within the bundle may carry current. Wire bundles present analytical challenges because the heat transfer path from conductors internal to the bundle is tortuous, relying on internal radiation and thermal interface conductance to move the heat from within the bundle to the external jacket where it can be carried away by convective and radiative heat transfer. The problem is further complicated by the dependence of wire electrical resistivity on temperature. Reduced heat transfer out of the bundle leads to higher conductor temperatures and, hence, increased resistive heat dissipation. Development of a generalized wire bundle thermal model is presented and compared with test data. The steady state heat balance for a single wire is derived and extended to the bundle configuration. The generalized model includes the effects of temperature varying resistance, internal radiation and thermal interface conductance, external radiation and temperature varying convective relief from the free surface. The sensitivity of the response to uncertainties in key model parameters is explored using Monte Carlo analysis.

  20. Isomonodromic Deformations and Very Stable Vector Bundles of Rank Two

    Science.gov (United States)

    Biswas, Indranil; Heu, Viktoria; Hurtubise, Jacques

    2017-12-01

    For the universal isomonodromic deformation of an irreducible logarithmic rank two connection over a smooth complex projective curve of genus at least two, consider the family of holomorphic vector bundles over curves underlying this universal deformation. In a previous work we proved that the vector bundle corresponding to a general parameter of this family is stable. Here we prove that the vector bundle corresponding to a general parameter is in fact very stable, meaning it does not admit any nonzero nilpotent Higgs field.

  1. Bundling Products and Services Through Modularization Strategies

    DEFF Research Database (Denmark)

    Bask, Anu; Hsuan, Juliana; Rajahonka, Mervi

    2012-01-01

    Modularity has been recognized as a powerful tool in improving the efficiency and management of product design and manufacturing. However, the integrated view on covering both, product and service modularity for product-service systems (PSS), is under researched. Therefore, in this paper our...... objective is to contribute to the PSS modularity. Thus, we describe configurations of PSSs and the bundling of products and services through modularization strategies. So far there have not been tools to analyze and determine the correct combinations of degrees of product and service modularities....

  2. Differential geometry bundles, connections, metrics and curvature

    CERN Document Server

    Taubes, Clifford Henry

    2011-01-01

    Bundles, connections, metrics and curvature are the 'lingua franca' of modern differential geometry and theoretical physics. This book will supply a graduate student in mathematics or theoretical physics with the fundamentals of these objects. Many of the tools used in differential topology are introduced and the basic results about differentiable manifolds, smooth maps, differential forms, vector fields, Lie groups, and Grassmanians are all presented here. Other material covered includes the basic theorems about geodesics and Jacobi fields, the classification theorem for flat connections, the

  3. Affine Flag Manifolds and Principal Bundles

    CERN Document Server

    Schmitt, Alexander HW

    2010-01-01

    Affine flag manifolds are infinite dimensional versions of familiar objects such as Gramann varieties. The book features lecture notes, survey articles, and research notes - based on workshops held in Berlin, Essen, and Madrid - explaining the significance of these and related objects (such as double affine Hecke algebras and affine Springer fibers) in representation theory (e.g., the theory of symmetric polynomials), arithmetic geometry (e.g., the fundamental lemma in the Langlands program), and algebraic geometry (e.g., affine flag manifolds as parameter spaces for principal bundles). Novel

  4. Vector bundles on complex projective spaces

    CERN Document Server

    Okonek, Christian; Spindler, Heinz

    1980-01-01

    This expository treatment is based on a survey given by one of the authors at the Séminaire Bourbaki in November 1978 and on a subsequent course held at the University of Göttingen. It is intended to serve as an introduction to the topical question of classification of holomorphic vector bundles on complex projective spaces, and can easily be read by students with a basic knowledge of analytic or algebraic geometry. Short supplementary sections describe more advanced topics, further results, and unsolved problems.

  5. PSH Transient Simulation Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-12-21

    PSH Transient Simulation Modeling presentation from the WPTO FY14 - FY16 Peer Review. Transient effects are an important consideration when designing a PSH system, yet numerical techniques for hydraulic transient analysis still need improvements for adjustable-speed (AS) reversible pump-turbine applications.

  6. Transient Ischemic Attack

    Medline Plus

    Full Text Available Transient Ischemic Attack TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an artery for a short time. The only ... TIA is that with TIA the blockage is transient (temporary). TIA symptoms occur rapidly and last a ...

  7. Discontinuous conduction in mouse bundle branches is caused by bundle-branch architecture

    NARCIS (Netherlands)

    van Veen, Toon A. B.; van Rijen, Harold V. M.; van Kempen, Marjan J. A.; Miquerol, Lucile; Opthof, Tobias; Gros, Daniel; Vos, Marc A.; Jongsma, Habo J.; de Bakker, Jacques M. T.

    2005-01-01

    Background - Recordings of the electrical activity of mouse bundle branches ( BBs) suggest reduced conduction velocity ( CV) in the midseptal compared with the proximal part of the BB. The present study was performed to elucidate the mechanism responsible for this slowing of conduction. Methods and

  8. Enthalpy and void distributions in subchannels of PHWR fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. W.; Choi, H.; Rhee, B. W. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    Two different types of the CANDU fuel bundles have been modeled for the ASSERT-IV code subchannel analysis. From calculated values of mixture enthalpy and void fraction distribution in the fuel bundles, it is found that net buoyancy effect is pronounced in the central region of the DUPIC fuel bundle when compared with the standard CANDU fuel bundle. It is also found that the central region of the DUPIC fuel bundle can be cooled more efficiently than that of the standard fuel bundle. From the calculated mixture enthalpy distribution at the exit of the fuel channel, it is found that the mixture enthalpy and void fraction can be highest in the peripheral region of the DUPIC fuel bundle. On the other hand, the enthalpy and the void fraction were found to be highest in the central region of the standard CANDU fuel bundle at the exit of the fuel channel. This study shows that the subchannel analysis is very useful in assessing thermal behavior of the fuel bundle that could be used in CANDU reactors. 10 refs., 4 figs., 2 tabs. (Author)

  9. Molybdenum-99-producing 37-element fuel bundle neutronically and thermal-hydraulically equivalent to a standard CANDU fuel bundle

    Energy Technology Data Exchange (ETDEWEB)

    Nichita, E., E-mail: Eleodor.Nichita@uoit.ca; Haroon, J., E-mail: Jawad.Haroon@uoit.ca

    2016-10-15

    Highlights: • A 37-element fuel bundle modified for {sup 99}Mo production in CANDU reactors is presented. • The modified bundle is neutronically and thermal-hydraulically equivalent to the standard bundle. • The modified bundle satisfies all safety criteria satisfied by the standard bundle. - Abstract: {sup 99m}Tc, the most commonly used radioisotope in diagnostic nuclear medicine, results from the radioactive decay of {sup 99}Mo which is currently being produced at various research reactors around the globe. In this study, the potential use of CANDU power reactors for the production of {sup 99}Mo is investigated. A modified 37-element fuel bundle, suitable for the production of {sup 99}Mo in existing CANDU-type reactors is proposed. The new bundle is specifically designed to be neutronically and thermal-hydraulically equivalent to the standard 37-element CANDU fuel bundle in normal, steady-state operation and, at the same time, be able to produce significant quantities of {sup 99}Mo when irradiated in a CANDU reactor. The proposed bundle design uses fuel pins consisting of a depleted-uranium centre surrounded by a thin layer of low-enriched uranium. The new molybdenum-producing bundle is analyzed using the lattice transport code DRAGON and the diffusion code DONJON. The proposed design is shown to produce 4081 six-day Curies of {sup 99}Mo activity per bundle when irradiated in the peak-power channel of a CANDU core, while maintaining the necessary reactivity and power rating limits. The calculated {sup 99}Mo yield corresponds to approximately one third of the world weekly demand. A production rate of ∼3 bundles per week can meet the global demand of {sup 99}Mo.

  10. Design and evaluate finned tube bundles

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. [ABCO Industries, Abilene, TX (United States)

    1996-09-01

    Finned tube bundles are widely used in heat exchangers, air coolers, waste heat boilers and fired heaters where energy transfer occurs between clean flue gases and a fluid with a high heat-transfer coefficient. They have several advantages including compactness, low gas pressure drop and low weight for a given duty compared to bare tube bundles. Choosing a fin type, arrangement and fin configuration requires a thorough analysis and economic evaluation. The solution is not unique since it depends on material and labor costs. Surface areas vary widely in finned tube designs for the same duty and gas pressure drop. Therefore, decisions should not be based on surface area alone. Plant engineers and consultants should consider operating costs in their evaluation because they accrue year after year. Selecting a boiler based on initial costs alone is not prudent. The paper discusses heat transfer and gas pressure drop with finned tubes, determining fin efficiency and effectiveness,g as pressure drop, tube wall and fin top temperatures, an example calculation, the effect of fin configuration on design, the effect of inline versus staggered arrangements and solid versus serrated fins, and concerns with high fin-density designs.

  11. Development boiling to sprinkled tube bundle

    Directory of Open Access Journals (Sweden)

    Kracík Petr

    2016-01-01

    Full Text Available This paper presents results of a studied heat transfer coefficient at the surface of a sprinkled tube bundle where boiling occurs. Research in the area of sprinkled exchangers can be divided into two major parts. The first part is research on heat transfer and determination of the heat transfer coefficient at sprinkled tube bundles for various liquids, whether boiling or not. The second part is testing of sprinkle modes for various tube diameters, tube pitches and tube materials and determination of individual modes’ interface. All results published so far for water as the falling film liquid apply to one to three tubes for which the mentioned relations studied are determined in rigid laboratory conditions defined strictly in advance. The sprinkled tubes were not viewed from the operational perspective where there are more tubes and various modes may occur in different parts with various heat transfer values. The article focuses on these processes. The tube is located in a low-pressure chamber where vacuum is generated using an exhauster via ejector. The tube consists of smooth copper tubes of 12 mm diameter placed horizontally one above another.

  12. Evaluation of Single-Bundle versus Double-Bundle PCL Reconstructions with More Than 10-Year Follow-Up

    Directory of Open Access Journals (Sweden)

    Masataka Deie

    2015-01-01

    Full Text Available Background. Posterior cruciate ligament (PCL injuries are not rare in acute knee injuries, and several recent anatomical studies of the PCL and reconstructive surgical techniques have generated improved patient results. Now, we have evaluated PCL reconstructions performed by either the single-bundle or double-bundle technique in a patient group followed up retrospectively for more than 10 years. Methods. PCL reconstructions were conducted using the single-bundle (27 cases or double-bundle (13 cases method from 1999 to 2002. The mean age at surgery was 34 years in the single-bundle group and 32 years in the double-bundle group. The mean follow-up period was 12.5 years. Patients were evaluated by Lysholm scoring, the gravity sag view, and knee arthrometry. Results. The Lysholm score after surgery was 89.1±5.6 points for the single-bundle group and 91.9±4.5 points for the double-bundle group. There was no significant difference between the methods in the side-to-side differences by gravity sag view or knee arthrometer evaluation, although several cases in both groups showed a side-to-side difference exceeding 5 mm by the latter evaluation method. Conclusions. We found no significant difference between single- and double-bundle PCL reconstructions during more than 10 years of follow-up.

  13. Qualification of the nuclear reactor core model DYN3D coupled to the thermohydraulic system code ATHLET, applied as an advanced tool for accident analysis of VVER-type reactors. Final report; Qualifizierung des Kernmodells DYN3D im Komplex mit dem Stoerfallcode ATHLET als fortgeschrittenes Werkzeug fuer die Stoerfallanalyse von WWER-Reaktoren. T. 1. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Grundmann, U.; Kliem, S.; Krepper, E.; Mittag, S; Rohde, U.; Schaefer, F.; Seidel, A.

    1998-03-01

    The nuclear reactor core model DYN3D with 3D neutron kinetics has been coupled to the thermohydraulic system code ATHLET. In the report, activities on qualification of the coupled code complex ATHLET-DYN3D as a validated tool for the accident analysis of russian VVER type reactors are described. That includes: - Contributions to the validation of the single codes ATHLET and DYN3D by the analysis of experiments on natural circulation behaviour in thermohydraulic test facilities and solution of benchmark tasks on reactivity initiated transients, - the acquisition and evaluation of measurement data on transients in nuclear power plants, the validation of ATHLET-DYN3D by calculating an accident with delayed scram and a pump trip in VVER plants, - the complementary improvement of the code DYN3D by extension of the neutron physical data base, implementation of an improved coolant mixing model, consideration of decay heat release and xenon transients, - the analysis of steam leak scenarios for VVER-440 type reactors with failure of different safety systems, investigation of different model options. The analyses showed, that with realistic coolant mixing modelling in the downcomer and the lower plenum, recriticality of the scramed reactor due to overcooling can be reached. The application of the code complex ATHLET-DYN3D in Czech Republic, Bulgaria and the Ukraine has been started. Future work comprises the verification of ATHLET-DYN3D with a DYN3D version for the square fuel element geometry of western PWR. (orig.) [Deutsch] Das Reaktorkernmodell DYN3D mit 3D Neutronenkinetik wurde an den Thermohydraulik-Systemcode ATHLET angekoppelt. Im vorliegenden Bericht werden Arbeiten zur Qualifizierung des gekoppelten Codekomplexes zu einem validierten Hilfsmittel fuer Stoerfallablaufanalysen zu Reaktoren des russischen Typs WWER dargestellt. Diese umfassten im einzelnen: - Beitraege zur Validierung der Einzelcodes ATHLET und DYN3D anhand der Nachrechnung von Experimenten zum

  14. TREAT Neutronics Analysis of Water-Loop Concept Accommodating LWR 9-rod Bundle

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Connie M.; Woolstenhulme, Nicolas E.; Parry, James R.; Bess, John D.; Housley, Gregory K.

    2016-09-01

    Abstract. Simulation of a variety of transient conditions has been successfully achieved in the Transient Reactor Test (TREAT) facility during operation between 1959 and 1994 to support characterization and safety analysis of nuclear fuels and materials. A majority of previously conducted tests were focused on supporting sodium-cooled fast reactor (SFR) designs. Experiments evolved in complexity. Simulation of thermal-hydraulic conditions expected to be encountered by fuels and materials in a reactor environment was realized in the development of TREAT sodium loop experiment vehicles. These loops accommodated up to 7-pin fuel bundles and served to simulate more closely the reactor environment while safely delivering large quantities of energy into the test specimen. Some of the immediate TREAT restart operations will be focused on testing light water reactor (LWR) accident tolerant fuels (ATF). Similar to the sodium loop objectives, a water loop concept, developed and analyzed in the 1990’s, aimed at achieving thermal-hydraulic conditions encountered in commercial power reactors. The historic water loop concept has been analyzed in the context of a reactivity insertion accident (RIA) simulation for high burnup LWR 2-pin and 3-pin fuel bundles. Findings showed sufficient energy could be deposited into the specimens for evaluation. Similar results of experimental feasibility for the water loop concept (past and present) have recently been obtained using MCNP6.1 with ENDF/B-VII.1 nuclear data libraries. The old water loop concept required only two central TREAT core grid spaces. Preparation for future experiments has resulted in a modified water loop conceptual design designated the TREAT water environment recirculating loop (TWERL). The current TWERL design requires nine TREAT core grid spaces in order to place the water recirculating pump under the TREAT core. Due to the effectiveness of water moderation, neutronics analysis shows that removal of seven additional

  15. An integral Riemann-Roch theorem for surface bundles

    DEFF Research Database (Denmark)

    Madsen, Ib Henning

    2010-01-01

    This paper is a response to a conjecture by T. Akita about an integral Riemann–Roch theorem for surface bundles.......This paper is a response to a conjecture by T. Akita about an integral Riemann–Roch theorem for surface bundles....

  16. Restriction Theorem for Principal bundles in Arbitrary Characteristic

    DEFF Research Database (Denmark)

    Gurjar, Sudarshan

    2015-01-01

    The aim of this paper is to prove two basic restriction theorem for principal bundles on smooth projective varieties in arbitrary characteristic generalizing the analogues theorems of Mehta-Ramanathan for vector bundles. More precisely, let G be a reductive algebraic group over an algebraically c...

  17. Phase Space Reduction of Star Products on Cotangent Bundles.

    NARCIS (Netherlands)

    Kowalzig, N.; Neumaier, N.; Pflaum, M.

    2005-01-01

    In this paper we construct star products on Marsden-Weinstein reduced spaces in case both the original phase space and the reduced phase space are (symplectomorphic to) cotangent bundles. Under the assumption that the original cotangent bundle $T^*Q$ carries a symplectic structure of form

  18. Monoubiquitination Inhibits the Actin Bundling Activity of Fascin.

    Science.gov (United States)

    Lin, Shengchen; Lu, Shuang; Mulaj, Mentor; Fang, Bin; Keeley, Tyler; Wan, Lixin; Hao, Jihui; Muschol, Martin; Sun, Jianwei; Yang, Shengyu

    2016-12-30

    Fascin is an actin bundling protein that cross-links individual actin filaments into straight, compact, and stiff bundles, which are crucial for the formation of filopodia, stereocillia, and other finger-like membrane protrusions. The dysregulation of fascin has been implicated in cancer metastasis, hearing loss, and blindness. Here we identified monoubiquitination as a novel mechanism that regulates fascin bundling activity and dynamics. The monoubiquitination sites were identified to be Lys247 and Lys250, two residues located in a positive charge patch at the actin binding site 2 of fascin. Using a chemical ubiquitination method, we synthesized chemically monoubiquitinated fascin and determined the effects of monoubiquitination on fascin bundling activity and dynamics. Our data demonstrated that monoubiquitination decreased the fascin bundling EC50, delayed the initiation of bundle assembly, and accelerated the disassembly of existing bundles. By analyzing the electrostatic properties on the solvent-accessible surface of fascin, we proposed that monoubiquitination introduced steric hindrance to interfere with the interaction between actin filaments and the positively charged patch at actin binding site 2. We also identified Smurf1 as a E3 ligase regulating the monoubiquitination of fascin. Our findings revealed a previously unidentified regulatory mechanism for fascin, which will have important implications for the understanding of actin bundle regulation under physiological and pathological conditions. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Lexical Bundles in L1 and L2 Academic Writing

    Science.gov (United States)

    Chen, Yu-Hua; Baker, Paul

    2010-01-01

    This paper adopts an automated frequency-driven approach to identify frequently-used word combinations (i.e., "lexical bundles") in academic writing. Lexical bundles retrieved from one corpus of published academic texts and two corpora of student academic writing (one L1, the other L2), were investigated both quantitatively and qualitatively.…

  20. Lexical Bundles: Facilitating University "Talk" in Group Discussions

    Science.gov (United States)

    Heng, Chan Swee; Kashiha, Hadi; Tan, Helen

    2014-01-01

    Group discussion forms an integral language experience for most language learners, providing them with an opportunity to express themselves in a naturalistic setting. Multi-word expressions are commonly used and one of them is lexical bundles. Lexical bundles are types of extended collocations that occur more commonly than we expect; they are…

  1. A novel microbond bundle pullout technique to evaluate the ...

    Indian Academy of Sciences (India)

    2017-07-26

    Jul 26, 2017 ... to be a need to develop a microbond bundle pullout test that is comparable in all aspects to the semi-empirical resin slab/fibre bundle pullout approach [9]. The improvement of the known draw backs of the single fibre microbond pullout method [7], such as the difficulty in formulation and testing (with lack.

  2. Hair bundles are specialized for ATP delivery via creatine kinase.

    NARCIS (Netherlands)

    Shin, J.B.; Streijger, F.; Beynon, A.J.; Peters, T.; Gadzala, L.; McMillen, D.; Bystrom, C.; Zee, C.E.E.M. van der; Wallimann, T.; Gillespie, P.G.

    2007-01-01

    When stimulated strongly, a hair cell's mechanically sensitive hair bundle may consume ATP too rapidly for replenishment by diffusion. To provide a broad view of the bundle's protein complement, including those proteins participating in energy metabolism, we used shotgun mass spectrometry methods to

  3. Smooth Bundling of Large Streaming and Sequence Graphs

    NARCIS (Netherlands)

    Hurter, C.; Ersoy, O.; Telea, A.

    2013-01-01

    Dynamic graphs are increasingly pervasive in modern information systems. However, understanding how a graph changes in time is difficult. We present here two techniques for simplified visualization of dynamic graphs using edge bundles. The first technique uses a recent image-based graph bundling

  4. Computational imaging through a fiber-optic bundle

    Science.gov (United States)

    Lodhi, Muhammad A.; Dumas, John Paul; Pierce, Mark C.; Bajwa, Waheed U.

    2017-05-01

    Compressive sensing (CS) has proven to be a viable method for reconstructing high-resolution signals using low-resolution measurements. Integrating CS principles into an optical system allows for higher-resolution imaging using lower-resolution sensor arrays. In contrast to prior works on CS-based imaging, our focus in this paper is on imaging through fiber-optic bundles, in which manufacturing constraints limit individual fiber spacing to around 2 μm. This limitation essentially renders fiber-optic bundles as low-resolution sensors with relatively few resolvable points per unit area. These fiber bundles are often used in minimally invasive medical instruments for viewing tissue at macro and microscopic levels. While the compact nature and flexibility of fiber bundles allow for excellent tissue access in-vivo, imaging through fiber bundles does not provide the fine details of tissue features that is demanded in some medical situations. Our hypothesis is that adapting existing CS principles to fiber bundle-based optical systems will overcome the resolution limitation inherent in fiber-bundle imaging. In a previous paper we examined the practical challenges involved in implementing a highly parallel version of the single-pixel camera while focusing on synthetic objects. This paper extends the same architecture for fiber-bundle imaging under incoherent illumination and addresses some practical issues associated with imaging physical objects. Additionally, we model the optical non-idealities in the system to get lower modelling errors.

  5. Frobenius pull backs of vector bundles in higher dimensions

    Indian Academy of Sciences (India)

    Frobenius pull backs; instability degree, vector bundles. 1. Introduction. Let X be a nonsingular projective variety defined over an algebraically closed field k of an arbitrary characteristic, and let H be a very ample line bundle on X. Let E be a torsion free sheaf on X. Then the notion of E being stable (resp. semistable) is well- ...

  6. On Harder–Narasimhan reductions for Higgs principal bundles

    Indian Academy of Sciences (India)

    in Ramanathan's paper. The aim of this paper is to generalize the methods of Biswas and Holla to give a unified approach to the case of principal bundles with Higgs structure on smooth projective varieties as well as the case of ramified bundles on smooth curves [4] (see §2, §5 for definitions). Recall that for the case of ...

  7. [Bundle-branch block depending on the heart rate].

    Science.gov (United States)

    Apostolov, L

    1975-01-01

    Five patients are reported, admitted to the hospital, with diseases predominantly of the cardio-vascular system. During the electrocardiographic examinations bundle branch block was established, depending on heart rate. It fluctuated within the physiological limits from 50 to 90/min. In three of the patients, the bundle branch block appeared with the quickening of the heart rate (tachycardia-depending bundle branch block) and in two of the patients--the bundle branch block appeared during the slowing down of the heart action and disappeared with its quickening (bradicardia-depending bundle branch block). A brief literature review is presented and attention is paid to the possible diagnostic errors and the treatment mode of those patients with cardiac tonic and antiarrhythmic medicaments.

  8. Bundles over Quantum RealWeighted Projective Spaces

    Directory of Open Access Journals (Sweden)

    Tomasz Brzeziński

    2012-09-01

    Full Text Available The algebraic approach to bundles in non-commutative geometry and the definition of quantum real weighted projective spaces are reviewed. Principal U(1-bundles over quantum real weighted projective spaces are constructed. As the spaces in question fall into two separate classes, the negative or odd class that generalises quantum real projective planes and the positive or even class that generalises the quantum disc, so do the constructed principal bundles. In the negative case the principal bundle is proven to be non-trivial and associated projective modules are described. In the positive case the principal bundles turn out to be trivial, and so all the associated modules are free. It is also shown that the circle (coactions on the quantum Seifert manifold that define quantum real weighted projective spaces are almost free.

  9. Artificial ciliary bundles with nano fiber tip links

    CERN Document Server

    Asadnia, Mohsen; Miao, Jianmin; Triantafyllou, Michael

    2015-01-01

    Mechanosensory ciliary bundles in fishes are the inspiration for carefully engineered artificial flow sensors. We report the development of a new class of ultrasensitive MEMS flow sensors that mimic the intricate morphology of the ciliary bundles, including the stereocilia, tip links, and the cupula, and thereby achieve threshold detection limits that match the biological example. An artificial ciliary bundle is achieved by fabricating closely-spaced arrays of polymer micro-pillars with gradiating heights. Tip links that form the fundamental sensing elements are realized through electrospinning aligned PVDF piezoelectric nano-fibers that link the distal tips of the polymer cilia. An optimized synthesis of hyaluronic acid-methacrylic anhydride hydrogel that results in properties close to the biological cupula, together with drop-casting method are used to form the artificial cupula that encapsulates the ciliary bundle. In testing, fluid drag force causes the ciliary bundle to slide, stretching the flexible nan...

  10. Superconductivity in an Inhomogeneous Bundle of Metallic and Semiconducting Nanotubes

    Directory of Open Access Journals (Sweden)

    Ilya Grigorenko

    2013-01-01

    Full Text Available Using Bogoliubov-de Gennes formalism for inhomogeneous systems, we have studied superconducting properties of a bundle of packed carbon nanotubes, making a triangular lattice in the bundle's transverse cross-section. The bundle consists of a mixture of metallic and doped semiconducting nanotubes, which have different critical transition temperatures. We investigate how a spatially averaged superconducting order parameter and the critical transition temperature depend on the fraction of the doped semiconducting carbon nanotubes in the bundle. Our simulations suggest that the superconductivity in the bundle will be suppressed when the fraction of the doped semiconducting carbon nanotubes will be less than 0.5, which is the percolation threshold for a two-dimensional triangular lattice.

  11. Framework for shape analysis of white matter fiber bundles.

    Science.gov (United States)

    Glozman, Tanya; Bruckert, Lisa; Pestilli, Franco; Yecies, Derek W; Guibas, Leonidas J; Yeom, Kristen W

    2017-12-02

    Diffusion imaging coupled with tractography algorithms allows researchers to image human white matter fiber bundles in-vivo. These bundles are three-dimensional structures with shapes that change over time during the course of development as well as in pathologic states. While most studies on white matter variability focus on analysis of tissue properties estimated from the diffusion data, e.g. fractional anisotropy, the shape variability of white matter fiber bundle is much less explored. In this paper, we present a set of tools for shape analysis of white matter fiber bundles, namely: (1) a concise geometric model of bundle shapes; (2) a method for bundle registration between subjects; (3) a method for deformation estimation. Our framework is useful for analysis of shape variability in white matter fiber bundles. We demonstrate our framework by applying our methods on two datasets: one consisting of data for 6 normal adults and another consisting of data for 38 normal children of age 11 days to 8.5 years. We suggest a robust and reproducible method to measure changes in the shape of white matter fiber bundles. We demonstrate how this method can be used to create a model to assess age-dependent changes in the shape of specific fiber bundles. We derive such models for an ensemble of white matter fiber bundles on our pediatric dataset and show that our results agree with normative human head and brain growth data. Creating these models for a large pediatric longitudinal dataset may improve understanding of both normal development and pathologic states and propose novel parameters for the examination of the pediatric brain. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Bundling of elastic filaments induced by hydrodynamic interactions

    Science.gov (United States)

    Man, Yi; Page, William; Poole, Robert J.; Lauga, Eric

    2017-12-01

    Peritrichous bacteria swim in viscous fluids by rotating multiple helical flagellar filaments. As the bacterium swims forward, all its flagella rotate in synchrony behind the cell in a tight helical bundle. When the bacterium changes its direction, the flagellar filaments unbundle and randomly reorient the cell for a short period of time before returning to their bundled state and resuming swimming. This rapid bundling and unbundling is, at its heart, a mechanical process whereby hydrodynamic interactions balance with elasticity to determine the time-varying deformation of the filaments. Inspired by this biophysical problem, we present in this paper what is perhaps the simplest model of bundling whereby two or more straight elastic filaments immersed in a viscous fluid rotate about their centerline, inducing rotational flows which tend to bend the filaments around each other. We derive an integrodifferential equation governing the shape of the filaments resulting from mechanical balance in a viscous fluid at low Reynolds number. We show that such equation may be evaluated asymptotically analytically in the long-wavelength limit, leading to a local partial differential equation governed by a single dimensionless bundling number. A numerical study of the dynamics predicted by the model reveals the presence of two configuration instabilities with increasing bundling numbers: first to a crossing state where filaments touch at one point and then to a bundled state where filaments wrap along each other in a helical fashion. We also consider the case of multiple filaments and the unbundling dynamics. We next provide an intuitive physical model for the crossing instability and show that it may be used to predict analytically its threshold and adapted to address the transition to a bundling state. We then use a macroscale experimental implementation of the two-filament configuration in order to validate our theoretical predictions and obtain excellent agreement. This long

  13. Restriction of Preferences to the Set of Consumption Bundles, In a Model with Production and Consumption Bundles

    NARCIS (Netherlands)

    Schalk, S.

    1999-01-01

    In contrast to the neo-classical theory of Arrow and Debreu, a model of a private ownership economy is presented, in which production and consumption bundles are treated separately. Each of the two types of bundles is assumed to establish a con- vex cone. Production technologies can convert

  14. Single-Bundle Versus Double-Bundle Reconstruction for Anterior Cruciate Ligament Rupture: A Meta-Analysis-Does Anatomy Matter?

    NARCIS (Netherlands)

    Eck, Carola F. Van; Kopf, Sebastian; Irrgang, James J.; Blankevoort, Leendert; Bhandari, Mohit; Fu, Freddie H.; Poolman, Rudolf W.

    2012-01-01

    Purpose: To determine whether double-bundle anterior cruciate ligament reconstruction leads to better restoration of anterior and rotational laxity and range of motion than single-bundle reconstruction. Methods: A search was performed in the Medline, Embase, CINAHL, and Cochrane databases. All

  15. Cost-effectiveness of a central venous catheter care bundle.

    Directory of Open Access Journals (Sweden)

    Kate A Halton

    Full Text Available BACKGROUND: A bundled approach to central venous catheter care is currently being promoted as an effective way of preventing catheter-related bloodstream infection (CR-BSI. Consumables used in the bundled approach are relatively inexpensive which may lead to the conclusion that the bundle is cost-effective. However, this fails to consider the nontrivial costs of the monitoring and education activities required to implement the bundle, or that alternative strategies are available to prevent CR-BSI. We evaluated the cost-effectiveness of a bundle to prevent CR-BSI in Australian intensive care patients. METHODS AND FINDINGS: A Markov decision model was used to evaluate the cost-effectiveness of the bundle relative to remaining with current practice (a non-bundled approach to catheter care and uncoated catheters, or use of antimicrobial catheters. We assumed the bundle reduced relative risk of CR-BSI to 0.34. Given uncertainty about the cost of the bundle, threshold analyses were used to determine the maximum cost at which the bundle remained cost-effective relative to the other approaches to infection control. Sensitivity analyses explored how this threshold alters under different assumptions about the economic value placed on bed-days and health benefits gained by preventing infection. If clinicians are prepared to use antimicrobial catheters, the bundle is cost-effective if national 18-month implementation costs are below $1.1 million. If antimicrobial catheters are not an option the bundle must cost less than $4.3 million. If decision makers are only interested in obtaining cash-savings for the unit, and place no economic value on either the bed-days or the health benefits gained through preventing infection, these cost thresholds are reduced by two-thirds. CONCLUSIONS: A catheter care bundle has the potential to be cost-effective in the Australian intensive care setting. Rather than anticipating cash-savings from this intervention, decision

  16. Effects of generation and optimization of libraries of effective sections in the analysis of transient in PWR reactors; Efectos de generacion y optimizacion de librerias de secciones eficaces en el analisis de transitorios en reactores PWR

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Cervera, S.; Garcia Herranz, N.; Cuervo, D.; Ahnert, C.

    2014-07-01

    In this paper evaluates the impact that has a certain mesh on a transient in a PWR reactor in the expulsion of a control bar. Have been used for this purpose the coupled codes neutronic and Thermo-hydraulic COBAYA3/COBRA-TF. This objective has been chosen the OECD/NEA PWR MOX/UO{sub 2} rod ejection transient benchmark provides isotopic compositions and defined geometric configurations that allow the use of codes lattice to generate own bookstores. The code used for this transport has been the code APOLLO2.8. The results show large discrepancies when using the benchmark library or libraries own by comparing them to the other participants solutions. The source of these discrepancies is the nodal effective sections provided in the benchmark. (Author)

  17. Bundling Actin Filaments From Membranes: Some Novel Players

    Directory of Open Access Journals (Sweden)

    Clément eThomas

    2012-08-01

    Full Text Available Progress in live-cell imaging of the cytoskeleton has significantly extended our knowledge about the organization and dynamics of actin filaments near the plasma membrane of plant cells. Noticeably, two populations of filamentous structures can be distinguished. On the one hand, fine actin filaments which exhibit an extremely dynamic behavior basically characterized by fast polymerization and prolific severing events, a process referred to as actin stochastic dynamics. On the other hand, thick actin bundles which are composed of several filaments and which are comparatively more stable although they constantly remodel as well. There is evidence that the actin cytoskeleton plays critical roles in trafficking and signaling at both the cell cortex and organelle periphery but the exact contribution of actin bundles remains unclear. A common view is that actin bundles provide the long-distance tracks used by myosin motors to deliver their cargo to growing regions and accordingly play a particularly important role in cell polarization. However, several studies support that actin bundles are more than simple passive highways and display multiple and dynamic roles in the regulation of many processes, such as cell elongation, polar auxin transport, stomatal and chloroplast movement, and defense against pathogens. The list of identified plant actin-bundling proteins is ever expanding, supporting that plant cells shape structurally and functionally different actin bundles. Here I review the most recently characterized actin-bundling proteins, with a particular focus on those potentially relevant to membrane trafficking and/or signaling.

  18. Aerosol retention in the flooded steam generator bundle during SGTR

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Terttaliisa, E-mail: terttaliisa.lind@psi.c [Paul Scherrer Institut, Department of Nuclear Energy and Safety, 5232 Villigen (Switzerland); Dehbi, Abdel; Guentay, Salih [Paul Scherrer Institut, Department of Nuclear Energy and Safety, 5232 Villigen (Switzerland)

    2011-01-15

    Research highlights: High retention of aerosol particles in a steam generator bundle flooded with water. Increasing particle inertia, i.e., particle size and velocity, increases retention. Much higher retention of aerosol particles in the steam generator bundle flooded with water than in a dry bundle. Much higher retention of aerosol particles in the steam generator bundle than in a bare pool. Bare pool models have to be adapted to be applicable for flooded bundles. - Abstract: A steam generator tube rupture in a pressurized water reactor may cause accidental release of radioactive particles into the environment. Its specific significance is in its potential to bypass the containment thereby providing a direct pathway of the radioactivity from the primary circuit to the environment. Under certain severe accident scenarios, the steam generator bundle may be flooded with water. In addition, some severe accident management procedures are designed to minimize the release of radioactivity into the environment by flooding the defective steam generator secondary side with water when the steam generator has dried out. To extend our understanding of the particle retention phenomena in the flooded steam generator bundle, tests were conducted in the ARTIST and ARTIST II programs to determine the effect of different parameters on particle retention. The effects of particle type (spherical or agglomerate), particle size, gas mass flow rate, and the break submergence on particle retention were investigated. Results can be summarized as follows: increasing particle inertia was found to increase retention in the flooded bundle. Particle shape, i.e., agglomerate or spherical structure, did not affect retention significantly. Even with a very low submergence, 0.3 m above the tube break, significant aerosol retention took place underlining the importance of the jet-bundle interactions close to the tube break. Droplets were entrained from the water surface with high gas flow rates

  19. Dark-field illuminated reflectance fiber bundle endoscopic microscope

    Science.gov (United States)

    Liu, Xuan; Huang, Yong; Kang, Jin U.

    2011-04-01

    We propose a reflectance fiber bundle microscope using a dark-field illumination configuration for applications in endoscopic medical imaging and diagnostics. Our experiment results show that dark-field illumination can effectively suppress strong specular reflection from the proximal end of the fiber bundle. We realized a lateral resolution of 4.4 μm using the dark-field illuminated fiber bundle configuration. To demonstrate the feasibility of using the system to study cell morphology, we obtained still and video images of two thyroid cancer cell lines. Our results clearly allow differentiation of different cancer cell types.

  20. Moduli of Parabolic Higgs Bundles and Atiyah Algebroids

    DEFF Research Database (Denmark)

    Logares, Marina; Martens, Johan

    2010-01-01

    In this paper we study the geometry of the moduli space of (non-strongly) parabolic Higgs bundles over a Riemann surface with marked points. We show that this space possesses a Poisson structure, extending the one on the dual of an Atiyah algebroid over the moduli space of parabolic vector bundles....... By considering the case of full flags, we get a Grothendieck–Springer resolution for all other flag types, in particular for the moduli spaces of twisted Higgs bundles, as studied by Markman and Bottacin and used in the recent work of Laumon–Ngô. We discuss the Hitchin system, and demonstrate that all...

  1. [Intermittent left bundle branch block - reversal to normal conduction during general anesthesia].

    Science.gov (United States)

    Silva, Ana Maria Oliveira Correia da; Silva, Emília Alexandra Gaspar Lima da

    Transient changes in intraoperative cardiac conduction are uncommon. Rare cases of the development or remission of complete left bundle branch block under general and locoregional anesthesia associated with myocardial ischemia, hypertension, tachycardia, and drugs have been reported. Complete left bundle branch block is an important clinical manifestation in some chronic hypertensive patients, which may also be a sign of coronary artery disease, aortic valve disease, or underlying cardiomyopathy. Although usually permanent, it can occur intermittently depending on heart rate (when heart rate exceeds a certain critical value). This is a case of complete left bundle branch block recorded in the preoperative period of urgent surgery that reverted to normal intraoperative conduction under general anesthesia after a decrease in heart rate. It resurfaced, intermittently and in a heart-rate-dependent manner, in the early postoperative period, eventually reverting to normal conduction in a sustained manner during semi-intensive unit monitoring. The test to identify markers of cardiac muscle necrosis was negative. Pain due to the emergency surgical condition and in the early postoperative period may have been the cause of the increase in heart rate up to the critical value, causing blockage. Although the development or remission of this blockade under anesthesia is uncommon, the anesthesiologist should be alert to the possibility of its occurrence. It may be benign; however, the correct diagnosis is very important. The electrocardiographic manifestations may mask or be confused with myocardial ischemia, factors that are especially important in a patient under general anesthesia unable to report the characteristic symptoms of ischemia. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  2. New-Onset Left Bundle Branch Block Induced by Transcutaneous Aortic Valve Implantation.

    Science.gov (United States)

    Massoullié, Grégoire; Bordachar, Pierre; Ellenbogen, Kenneth A; Souteyrand, Géraud; Jean, Frédéric; Combaret, Nicolas; Vorilhon, Charles; Clerfond, Guillaume; Farhat, Mehdi; Ritter, Philippe; Citron, Bernard; Lusson, Jean-R; Motreff, Pascal; Ploux, Sylvain; Eschalier, Romain

    2016-03-01

    New-onset left bundle branch block (LBBB) is a specific concern of transcutaneous aortic valve implantation (TAVI) given its estimated incidence ranging from 5% to 65%. This high rate of occurrence is dependent on the type of device used (size and shape), implantation methods, and patient co-morbidities. The appearance of an LBBB after TAVI reflects a very proximal lesion of the left bundle branch as it exits the bundle of His. At times transient, its persistence can lead to permanent pacemaker implantation in 15% to 20% of cases, most often for high-degree atrioventricular block. The management of LBBB after TAVI is currently not defined by international societies resulting in individual centers developing their own management strategy. The potential consequences of LBBB are dysrhythmias (atrioventricular block, syncope, and sudden death) and functional (heart failure) complications. Prompt postprocedural recognition and management (permanent pacemaker implantation) of patients prevents the occurrence of potential complications and may constitute the preferred approach in this frail and elderly population despite additional costs and complications of cardiac pacing. Moreover, the expansion of future indications for TAVI necessitates better identification of the predictive factors for the development of LBBB. Indeed, long-term right ventricular pacing may potentially increase the risk of developing heart failure in this population. In conclusion, it is thus imperative to not only develop new aortic prostheses with a less-deleterious impact on the conduction system but also to prescribe appropriate pacing modes in this frail population. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Intermittent left bundle branch block - reversal to normal conduction during general anesthesia

    Directory of Open Access Journals (Sweden)

    Ana Maria Oliveira Correia da Silva

    Full Text Available Abstract Background and objectives: Transient changes in intraoperative cardiac conduction are uncommon. Rare cases of the development or remission of complete left bundle branch block under general and locoregional anesthesia associated with myocardial ischemia, hypertension, tachycardia, and drugs have been reported. Complete left bundle branch block is an important clinical manifestation in some chronic hypertensive patients, which may also be a sign of coronary artery disease, aortic valve disease, or underlying cardiomyopathy. Although usually permanent, it can occur intermittently depending on heart rate (when heart rate exceeds a certain critical value. Case report: This is a case of complete left bundle branch block recorded in the preoperative period of urgent surgery that reverted to normal intraoperative conduction under general anesthesia after a decrease in heart rate. It resurfaced, intermittently and in a heart-rate-dependent manner, in the early postoperative period, eventually reverting to normal conduction in a sustained manner during semi-intensive unit monitoring. The test to identify markers of cardiac muscle necrosis was negative. Pain due to the emergency surgical condition and in the early postoperative period may have been the cause of the increase in heart rate up to the critical value, causing blockage. Conclusions: Although the development or remission of this blockade under anesthesia is uncommon, the anesthesiologist should be alert to the possibility of its occurrence. It may be benign; however, the correct diagnosis is very important. The electrocardiographic manifestations may mask or be confused with myocardial ischemia, factors that are especially important in a patient under general anesthesia unable to report the characteristic symptoms of ischemia.

  4. Implementation of the optimization for the methodology of the neutronic calculation and thermo-hydraulic in IEA-R1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Stefani, Giovanni Laranjo de; Conti, Thadeu das Neves; Fedorenko, Giuliana G.; Castro, Vinicius A.; Maio, Mireia F., E-mail: gstefani@ipen.b, E-mail: tnconti@ipen.b, E-mail: g.fedorenko@ipen.b, E-mail: vcastro@ipen.b, E-mail: mfmaio@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Santos, Thiago Augusto dos, E-mail: tsantos@ipen.b [Universidade de Sao Paulo (IFUSP), Sao Paulo, SP (Brazil). Inst. de Fisica

    2011-07-01

    This work objective was to create a manager program that would automate the programs and computer codes in use for neutronic calculation and thermo-hydraulic in IEA-R1 reactor thus making the process for calculation of safety parameters and for configuration change up to 98% faster than that used in the reactor today. This process was tested in combination with the reactor operators and is being implemented by the quality department. The main codes and programs involved in the calculations of configuration change are Leopard, Hammier-Technion, Twodb, Citation and Cobra. Calculations of delayed neutron and criticality coefficients given in the process of safety parameters calculation are given by the Hammer-Technion and Citation in a process that involves about eleven repetitions so that it meets all the necessary conditions (such different temperatures of the moderator and fuel). The results are entirely consistent with the expected and absolutely the same as those given by manual process. Thus the work shows its reliability as well the advantage of saving time, once a process that could take up to four hours was turned in one that takes around five minutes when done in a home computer. Much of this advantage is due to the fact that were created subprograms to treat the output of each program used and transform them into the input of the other programs, removing from it the intermediate essential data for this to occur, thus avoiding also a possible human error by handling the various data supplied. (author)

  5. Thermo-hydraulic modelling of the South East Gas Pipeline System - an integrated model; Modelagem termo-hidraulica do Sistema de Gasodutos do Sudeste : um modelo integrado

    Energy Technology Data Exchange (ETDEWEB)

    Vianna Neto, Armando M.; Santos, Arnaldo M.; Mercon, Eduardo G. [TRANSPETRO - PETROBRAS Transportes, Rio de Janeiro, RJ (Brazil)

    2003-07-01

    This paper presents the development of an integrated simulation model, for the numerical calculation of thermal-hydraulic behaviors in the Brazilian southeast onshore gas pipeline flow system, remotely operated by TRANSPETRO's Gas Pipeline Control Centre (CCG). In its final application, this model is supposed to provide simulated results at the closer range to reality, in order to improve gas pipeline simulation studies and evaluations for the system in question. Considering the fact that numerical thermo-hydraulic simulation becomes the CCG's most important tool to analyze the boundary conditions to adjust the mentioned gas flow system, this paper seeks and takes aim to the optimization of the following prime attributions of a gas pipeline control centre: verification of system behaviors, face to some unit maintenance stop or procedure, programmed or not, or to some new gas outlet or inlet connection to the system; daily operational compatibility analysis between programmed and realized gas volumes; gas technical expedition and delivery analysis. Finally, all this work was idealized and carried out within the one-phase flow domain (dry gas) (author)

  6. Thermohydraulic simulation of HTR-10 nuclear reactor core using realistic CFD approach; Simulacao termohidraulica do nucleo do reator nuclear HTR-10 com o uso da abordagem realistica CFD

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alexandro S.; Dominguez, Dany S., E-mail: alexandrossilva@gmail.com, E-mail: dsdominguez@gmail.com [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil); Mazaira, Leorlen Y. Rojas; Hernandez, Carlos R.G., E-mail: leored1984@gmail.com, E-mail: cgh@instec.cu [Instituto Superior de Tecnologias y Ciencias Aplicadas, La Habana (Cuba); Lira, Carlos Alberto Brayner de Oliveira, E-mail: cabol@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2015-07-01

    High-temperature gas-cooled reactors (HTGRs) have the potential to be used as possible energy generation sources in the near future, owing to their inherently safe performance by using a large amount of graphite, low power density design, and high conversion efficiency. However, safety is the most important issue for its commercialization in nuclear energy industry. It is very important for safety design and operation of an HTGR to investigate its thermal–hydraulic characteristics. In this article, it was performed the thermal–hydraulic simulation of compressible flow inside the core of the pebble bed reactor HTR (High Temperature Reactor)-10 using Computational Fluid Dynamics (CFD). The realistic approach was used, where every closely packed pebble is realistically modelled considering a graphite layer and sphere of fuel. Due to the high computational cost is impossible simulate the full core; therefore, the geometry used is a column of FCC (Face Centered Cubic) cells, with 41 layers and 82 pebbles. The input data used were taken from the thermohydraulic IAEA Benchmark (TECDOC-1694). The results show the profiles of velocity and temperature of the coolant in the core, and the temperature distribution inside the pebbles. The maximum temperatures in the pebbles do not exceed the allowable limit for this type of nuclear fuel. (author)

  7. Feasibility study of the university of Utah TRIGA reactor power upgrade - part II: Thermohydraulics and heat transfer study in respect to cooling system requirements and design

    Directory of Open Access Journals (Sweden)

    Babitz Philip

    2013-01-01

    Full Text Available The thermodynamic conditions of the University of Utah's TRIGA Reactor were simulated using SolidWorks Flow Simulation, Ansys, Fluent and PARET-ANL. The models are developed for the reactor's currently maximum operating power of 90 kW, and a few higher power levels to analyze thermohydraulics and heat transfer aspects in determining a design basis for higher power including the cost estimate. It was found that the natural convection current becomes much more pronounced at higher power levels with vortex shedding also occurring. A departure from nucleate boiling analysis showed that while nucleate boiling begins near 210 kW it remains in this state and does not approach the critical heat flux at powers up to 500 kW. Based on these studies, two upgrades are proposed for extended operation and possibly higher reactor power level. Together with the findings from Part I studies, we conclude that increase of the reactor power is highly feasible yet dependable on its purpose and associated investments.

  8. Numerical Study on Influence of Cross Flow on Rewetting of AHWR Fuel Bundle

    Directory of Open Access Journals (Sweden)

    Mithilesh Kumar

    2014-01-01

    Full Text Available Numerical study on AHWR fuel bundle has been carried out to assess influence of circumferential and cross flow rewetting on the conduction heat transfer. The AHWR fuel bundle quenching under accident condition is designed primarily with radial jets at several axial locations. A 3D (r, θ, z transient conduction fuel pin model has been developed to carry out the study with a finite difference method (FDM technique with alternating direction implicit (ADI scheme. The single pin has been considered to study effect of circumferential conduction and multipins have been considered to study the influence of cross flow. Both analyses are carried out with the same fluid temperature and heat transfer coefficients as boundary conditions. It has been found from the analyses that, for radial jet, the circumferential conduction is significant and due to influence of overall cross flow the reductions in fuel temperature in the same quench plane in different rings are different with same initial surface temperature. Influence of cross flow on rewetting is found to be very significant. Outer fuel pins rewetting time is higher than inner.

  9. Simulation of finite size effects of the fiber bundle model

    Science.gov (United States)

    Hao, Da-Peng; Tang, Gang; Xun, Zhi-Peng; Xia, Hui; Han, Kui

    2018-01-01

    In theory, the macroscopic fracture of materials should correspond with the thermodynamic limit of the fiber bundle model. However, the simulation of a fiber bundle model with an infinite size is unrealistic. To study the finite size effects of the fiber bundle model, fiber bundle models of various size are simulated in detail. The effects of system size on the constitutive behavior, critical stress, maximum avalanche size, avalanche size distribution, and increased step number of external load are explored. The simulation results imply that there is no feature size or cut size for macroscopic mechanical and statistical properties of the model. The constitutive curves near the macroscopic failure for various system size can collapse well with a simple scaling relationship. Simultaneously, the introduction of a simple extrapolation method facilitates the acquisition of more accurate simulation results in a large-limit system, which is better for comparison with theoretical results.

  10. Improved Conjugate Gradient Bundle Adjustment of Dunhuang Wall Painting Images

    Science.gov (United States)

    Hu, K.; Huang, X.; You, H.

    2017-09-01

    Bundle adjustment with additional parameters is identified as a critical step for precise orthoimage generation and 3D reconstruction of Dunhuang wall paintings. Due to the introduction of self-calibration parameters and quasi-planar constraints, the structure of coefficient matrix of the reduced normal equation is banded-bordered, making the solving process of bundle adjustment complex. In this paper, Conjugate Gradient Bundle Adjustment (CGBA) method is deduced by calculus of variations. A preconditioning method based on improved incomplete Cholesky factorization is adopt to reduce the condition number of coefficient matrix, as well as to accelerate the iteration rate of CGBA. Both theoretical analysis and experimental results comparison with conventional method indicate that, the proposed method can effectively conquer the ill-conditioned problem of normal equation and improve the calculation efficiency of bundle adjustment with additional parameters considerably, while maintaining the actual accuracy.

  11. Bundles of Norms About Teen Sex and Pregnancy.

    Science.gov (United States)

    Mollborn, Stefanie; Sennott, Christie

    2015-09-01

    Teen pregnancy is a cultural battleground in struggles over morality, education, and family. At its heart are norms about teen sex, contraception, pregnancy, and abortion. Analyzing 57 interviews with college students, we found that "bundles" of related norms shaped the messages teens hear. Teens did not think their communities encouraged teen sex or pregnancy, but normative messages differed greatly, with either moral or practical rationalizations. Teens readily identified multiple norms intended to regulate teen sex, contraception, abortion, childbearing, and the sanctioning of teen parents. Beyond influencing teens' behavior, norms shaped teenagers' public portrayals and post hoc justifications of their behavior. Although norm bundles are complex to measure, participants could summarize them succinctly. These bundles and their conflicting behavioral prescriptions create space for human agency in negotiating normative pressures. The norm bundles concept has implications for teen pregnancy prevention policies and can help revitalize social norms for understanding health behaviors. © The Author(s) 2014.

  12. Some applications on tangent bundle with Kaluza-Klein metric

    Directory of Open Access Journals (Sweden)

    Murat Altunbaş

    2017-01-01

    Full Text Available In this paper, differential equations of geodesics; parallelism, incompressibility and closeness conditions of the horizontal and complete lift of the vector fields are investigated with respect to Kaluza-Klein metric on tangent bundle.

  13. Algebraic Frobenius splitting of cotangent bundles of flag varieties

    National Research Council Canada - National Science Library

    Hague, Chuck

    2013-01-01

    Following the program of algebraic Frobenius splitting begun by Kumar and Littelmann, we use representation-theoretic techniques to construct a Frobenius splitting of the cotangent bundle of the flag...

  14. Design and synthesis of DNA four-helix bundles.

    Science.gov (United States)

    Rangnekar, Abhijit; Gothelf, Kurt V; LaBean, Thomas H

    2011-06-10

    The field of DNA nanotechnology has evolved significantly in the past decade. Researchers have succeeded in synthesizing tile-based structures and using them to form periodic lattices in one, two and three dimensions. Origami-based structures have also been used to create nanoscale structures in two and three dimensions. Design and construction of DNA bundles with fixed circumference has added a new dimension to the field. Here we report the design and synthesis of a DNA four-helix bundle. It was found to be extremely rigid and stable. When several such bundles were assembled using appropriate sticky-ends, they formed micrometre-long filaments. However, when creation of two-dimensional sheet-like arrays of the four-helix bundles was attempted, nanoscale rings were observed instead. The exact reason behind the nanoring formation is yet to be ascertained, but it provides an exciting prospect for making programmable circular nanostructures using DNA.

  15. IMPROVED CONJUGATE GRADIENT BUNDLE ADJUSTMENT OF DUNHUANG WALL PAINTING IMAGES

    Directory of Open Access Journals (Sweden)

    K. Hu

    2017-09-01

    Full Text Available Bundle adjustment with additional parameters is identified as a critical step for precise orthoimage generation and 3D reconstruction of Dunhuang wall paintings. Due to the introduction of self-calibration parameters and quasi-planar constraints, the structure of coefficient matrix of the reduced normal equation is banded-bordered, making the solving process of bundle adjustment complex. In this paper, Conjugate Gradient Bundle Adjustment (CGBA method is deduced by calculus of variations. A preconditioning method based on improved incomplete Cholesky factorization is adopt to reduce the condition number of coefficient matrix, as well as to accelerate the iteration rate of CGBA. Both theoretical analysis and experimental results comparison with conventional method indicate that, the proposed method can effectively conquer the ill-conditioned problem of normal equation and improve the calculation efficiency of bundle adjustment with additional parameters considerably, while maintaining the actual accuracy.

  16. CANFLEX fuel bundle cross-flow endurance test (test report)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Deok; Chung, C. H.; Chang, S. K.; Kim, B. D.

    1997-04-01

    As part of the normal refuelling sequence of CANDU nuclear reactor, both new and irradiated bundles can be parked in the cross-flow region of the liner tubes. This situation occurs normally for a few minutes. The fuel bundle which is subjected to the cross-flow should be capable of withstanding the consequences of cross flow for normal periods, and maintain its mechanical integrity. The cross-flow endurance test was conducted for CANFLEX bundle, latest developed nuclear fuel, at CANDU-Hot Test Loop. The test was carried out during 4 hours at the inlet cross-flow region. After the test, the bundle successfully met all acceptance criteria after the 4 hours cross-flow test. (author). 2 refs., 3 tabs.

  17. Introductory lectures on fibre bundles and topology for physicists

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, G.H.

    1978-05-01

    These lectures may provide useful background material for understanding gauge theories, particularly the nonperturbative effects such as instantons and monopoles. The mathematical language of topology and fibre bundles is introduced.

  18. Bohr--Sommerfeld Lagrangians of moduli spaces of Higgs bundles

    DEFF Research Database (Denmark)

    Biswas, Indranil; Gammelgaard, Niels Leth; Logares, Marina

    Let $X$ be a compact connected Riemann surface of genus at least two. Let $M_H(r,d)$ denote the moduli space of semistable Higgs bundles on $X$ of rank $r$ and degree $d$. We prove that the compact complex Bohr-Sommerfeld Lagrangians of $M_H(r,d)$ are precisely the irreducible components of the n......Let $X$ be a compact connected Riemann surface of genus at least two. Let $M_H(r,d)$ denote the moduli space of semistable Higgs bundles on $X$ of rank $r$ and degree $d$. We prove that the compact complex Bohr-Sommerfeld Lagrangians of $M_H(r,d)$ are precisely the irreducible components...... of the nilpotent cone in $M_H(r,d)$. This generalizes to Higgs $G$-bundles and also to the parabolic Higgs bundles....

  19. Design and synthesis of DNA four-helix bundles

    Energy Technology Data Exchange (ETDEWEB)

    Rangnekar, Abhijit; Gothelf, Kurt V [Department of Chemistry, Centre for DNA Nanotechnology (CDNA) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000 Aarhus C (Denmark); LaBean, Thomas H, E-mail: kvg@chem.au.dk, E-mail: thl@cs.duke.edu [Department of Chemistry, Duke University, Durham, NC 27708 (United States)

    2011-06-10

    The field of DNA nanotechnology has evolved significantly in the past decade. Researchers have succeeded in synthesizing tile-based structures and using them to form periodic lattices in one, two and three dimensions. Origami-based structures have also been used to create nanoscale structures in two and three dimensions. Design and construction of DNA bundles with fixed circumference has added a new dimension to the field. Here we report the design and synthesis of a DNA four-helix bundle. It was found to be extremely rigid and stable. When several such bundles were assembled using appropriate sticky-ends, they formed micrometre-long filaments. However, when creation of two-dimensional sheet-like arrays of the four-helix bundles was attempted, nanoscale rings were observed instead. The exact reason behind the nanoring formation is yet to be ascertained, but it provides an exciting prospect for making programmable circular nanostructures using DNA.

  20. [Transient epileptic amnesia].

    Science.gov (United States)

    Muramatsu, Kazuhiro; Yoshizaki, Takahito

    2016-03-01

    Transient amnesia is one of common clinical phenomenon of epilepsy that are encountered by physicians. The amnestic attacks are often associated with persistent memory disturbances. Epilepsy is common among the elderly, with amnesia as a common symptom and convulsions relatively uncommon. Therefore, amnesia due to epilepsy can easily be misdiagnosed as dementia. The term 'transient epileptic amnesia (TEA)' was introduced in the early 1990s by Kapur, who highlighted that amnestic attacks caused by epilepsy can be similar to those occurring in 'transient global amnesia', but are distinguished by features brevity and recurrence. In 1998, Zeman et al. proposed diagnostic criteria for TEA.

  1. A Discrete Theory of Connections on Principal Bundles

    OpenAIRE

    Leok, M; Marsden, JE; Weinstein, AD

    2017-01-01

    Connections on principal bundles play a fundamental role in expressing the equations of motion for mechanical systems with symmetry in an intrinsic fashion. A discrete theory of connections on principal bundles is constructed by introducing the discrete analogue of the Atiyah sequence, with a connection corresponding to the choice of a splitting of the short exact sequence. Equivalent representations of a discrete connection are considered, and an extension of the pair groupoid composition, t...

  2. On the Geometry of Cotangent Bundles of Lie Groups

    OpenAIRE

    Manga, Bakary

    2015-01-01

    Lie groups of automorphisms of cotangent bundles of Lie groups are completely characterized and interesting results are obtained. We give prominence to the fact that the Lie groups of automorphisms of cotangent bundles of Lie groups are super symmetric Lie groups. In the cases of orthogonal Lie lgebras, semi-simple Lie algebras and compact Lie algebras we recover by simple methods interesting co-homological known results. The Lie algebra of prederivations encompasses the one of derivations as...

  3. CHF prediction in rod bundles using round tube data

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Wallen F.; Veloso, Maria A.F.; Pereira, Cláubia; Costa, Antonella L., E-mail: wallenfds@yahoo.com.br, E-mail: mdora@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2017-07-01

    The present work concerns the use of 1995 CHF table for uniformly heated round tubes, developed jointly by Canadian and Russian researchers, for the prediction of critical heat fluxes in rod bundles geometries. Comparisons between measured and calculated critical heat fluxes indicate that this table could be applied to rod bundles provided that a suitable correction factor is employed. The tolerance limits associated with the departure from nucleate boiling ratio (DNBR) are evaluated by using statistical analysis. (author)

  4. Page 1 Moduli for bundles over curves - 325 through the ...

    Indian Academy of Sciences (India)

    (B End V, with the reduced structure. Note that C is an open subscheme in C and C is a multicone in G) End V. By the hypothesis of the lemma and assumption Mo = G, for te Twe have an isomorphism (p, Eo- ºr, We can interpret p, as a section of the fiber bundle (e. X ..) (G) with fiber G associated to the G × G. bundle Eo * Č, ...

  5. Mitotic spindle: kinetochore fibers hold on tight to interpolar bundles.

    Science.gov (United States)

    Tolić, Iva M

    2017-07-19

    When a cell starts to divide, it forms a spindle, a micro-machine made of microtubules, which separates the duplicated chromosomes. The attachment of microtubules to chromosomes is mediated by kinetochores, protein complexes on the chromosome. Spindle microtubules can be divided into three major classes: kinetochore microtubules, which form k-fibers ending at the kinetochore; interpolar microtubules, which extend from the opposite sides of the spindle and interact in the middle; and astral microtubules, which extend towards the cell cortex. Recent work in human cells has shown a close relationship between interpolar and kinetochore microtubules, where interpolar bundles are attached laterally to kinetochore fibers almost all along their length, acting as a bridge between sister k-fibers. Most of the interpolar bundles are attached to a pair of sister kinetochore fibers and vice versa. Thus, the spindle is made of modules consisting of a pair of sister kinetochore fibers and a bundle of interpolar microtubules that connects them. These interpolar bundles, termed bridging fibers, balance the forces acting at kinetochores and support the rounded shape of the spindle during metaphase. This review discusses the structure, function, and formation of kinetochore fibers and interpolar bundles, with an emphasis on how they interact. Their connections have an impact on the force balance in the spindle and on chromosome movement during mitosis because the forces in interpolar bundles are transmitted to kinetochore fibers and hence to kinetochores through these connections.

  6. Splitting 3-plane sub-bundles over the product of two real projective spaces

    Directory of Open Access Journals (Sweden)

    Maria Hermínia de Paula Leite Mello

    2003-11-01

    Full Text Available Let α be a real vector bundle of fiber dimension three over the product RP(m×RP(n which splits as a Whitney sum of line bundles. We show that the necessary and sufficient conditions for α to embed as a sub-bundle of a certain family of vector bundles β of fiber dimension m+n is the vanishing of the last three Stiefel-Whitney classes of the virtual bundle0 β−α. Among the target bundles β we consider the tangent bundle.

  7. Transient Ischemic Attack

    Medline Plus

    Full Text Available ... TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an ... a short time. The only difference between a stroke and TIA is that with TIA the blockage ...

  8. Transient tic disorder

    Science.gov (United States)

    ... makes 1 or many brief, repeated, movements or noises (tics). These movements or noises are involuntary (not on purpose). Causes Transient tic ... less than a year. Other disorders such as anxiety , attention deficit hyperactivity disorder ( ADHD ), uncontrollable movement ( myoclonus ), ...

  9. Transient Ischemic Attack

    Medline Plus

    Full Text Available ... Ischemic Attack TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an artery for a short time. The only difference between a stroke ...

  10. Transient Microcavity Sensor

    CERN Document Server

    Shu, Fang-Jie; Özdemir, Şahin Kaya; Yang, Lan; Guo, Guang-Can

    2015-01-01

    A transient and high sensitivity sensor based on high-Q microcavity is proposed and studied theoretically. There are two ways to realize the transient sensor: monitor the spectrum by fast scanning of probe laser frequency or monitor the transmitted light with fixed laser frequency. For both methods, the non-equilibrium response not only tells the ultrafast environment variance, but also enable higher sensitivity. As examples of application, the transient sensor for nanoparticles adhering and passing by the microcavity is studied. It's demonstrated that the transient sensor can sense coupling region, external linear variation together with the speed and the size of a nanoparticle. We believe that our researches will open a door to the fast dynamic sensing by microcavity.

  11. Transient multivariable sensor evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Vilim, Richard B.; Heifetz, Alexander

    2017-02-21

    A method and system for performing transient multivariable sensor evaluation. The method and system includes a computer system for identifying a model form, providing training measurement data, generating a basis vector, monitoring system data from sensor, loading the system data in a non-transient memory, performing an estimation to provide desired data and comparing the system data to the desired data and outputting an alarm for a defective sensor.

  12. A quantitative histopathological study of right bundle branch block complicating acute anteroseptal myocardial infarction.

    OpenAIRE

    Okabe, M; Fukuda, K; Nakashima, Y; Hiroki, T; Arakawa, K; Kikuchi, M

    1991-01-01

    The aim of the present study was to evaluate whether necrosis of the right bundle branch is responsible for development of right bundle branch block in acute myocardial infarction. Twenty patients with acute anteroseptal myocardial infarction were studied--10 with right bundle branch block (group A) and 10 without (group B)--to evaluate by serial sectioning the pathological extent of myocardial infarction surrounding the right bundle branch and also that of right bundle branch necrosis. Myoca...

  13. SCADOP: Phenomenological modeling of dryout in nuclear fuel rod bundles

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Arnab, E-mail: arnie@barc.gov.in; Chandraker, D.K., E-mail: dineshkc@barc.gov.in; Vijayan, P.K., E-mail: vijayanp@barc.gov.in

    2015-11-15

    Highlights: • Phenomenological model for annular flow dryout is presented. • The model evaluates initial entrained fraction using a new methodology. • The history effect in annular flow is predicted and validated. • Rod bundle dryout is predicted using subchannel methodology. • Model is validated against experimental dryout data in tubes and rod bundles. - Abstract: Analysis and prediction of dryout is of important consequence to safety of nuclear fuel clusters of boiling water type of reactors. Traditionally, experimental correlations are used for dryout predictions. Since these correlations are based on operating parameters and do not aim to model the underlying phenomena, there has been a proliferation of the correlations, each catering to some specific bundle geometry under a specific set of operating conditions. Moreover, such experiments are extremely costly. In general, changes in tested bundle geometry for improvement in thermal-hydraulic performance would require re-experimentation. Understanding and modeling the basic processes leading to dryout in flow boiling thus has great incentive. Such a model has the ability to predict dryout in any rod bundle geometry, unlike the operating parameter based correlation approach. Thus more informed experiments can be carried out. A good model can, reduce the number of experiments required during the iterations in bundle design. In this paper, a phenomenological model as indicated above is presented. The model incorporates a new methodology to estimate the Initial Entrained Fraction (IEF), i.e., entrained fraction at the onset of annular flow. The incorporation of this new methodology is important since IEF is often assumed ad-hoc and sometimes also used as a parameter to tune the model predictions to experimental data. It is highlighted that IEF may be low under certain conditions against the general perception of a high IEF due to influence of churn flow. It is shown that the same phenomenological model is

  14. Histones bundle F-actin filaments and affect actin structure.

    Science.gov (United States)

    Blotnick, Edna; Sol, Asaf; Muhlrad, Andras

    2017-01-01

    Histones are small polycationic proteins complexed with DNA located in the cell nucleus. Upon apoptosis they are secreted from the cells and react with extracellular polyanionic compounds. Actin which is a polyanionic protein, is also secreted from necrotic cells and interacts with histones. We showed that both histone mixture (histone type III) and the recombinant H2A histone bundles F-actin, increases the viscosity of the F-actin containing solution and polymerizes G-actin. The histone-actin bundles are relatively insensitive to increase of ionic strength, unlike other polycation, histatin, lysozyme, spermine and LL-37 induced F-actin bundles. The histone-actin bundles dissociate completely only in the presence of 300-400 mM NaCl. DNA, which competes with F-actin for histones, disassembles histone induced actin bundles. DNase1, which depolymerizes F- to G-actin, actively unbundles the H2A histone induced but slightly affects the histone mixture induced actin bundles. Cofilin decreases the amount of F-actin sedimented by low speed centrifugation, increases light scattering and viscosity of F-actin-histone mixture containing solutions and forms star like superstructures by copolymerizing G-actin with H2A histone. The results indicate that histones are tightly attached to F-actin by strong electrostatic and hydrophobic forces. Since both histones and F-actin are present in the sputum of patients with cystic fibrosis, therefore, the formation of the stable histone-actin bundles can contribute to the pathology of this disease by increasing the viscosity of the sputum. The actin-histone interaction in the nucleus might affect gene expression.

  15. Histones bundle F-actin filaments and affect actin structure.

    Directory of Open Access Journals (Sweden)

    Edna Blotnick

    Full Text Available Histones are small polycationic proteins complexed with DNA located in the cell nucleus. Upon apoptosis they are secreted from the cells and react with extracellular polyanionic compounds. Actin which is a polyanionic protein, is also secreted from necrotic cells and interacts with histones. We showed that both histone mixture (histone type III and the recombinant H2A histone bundles F-actin, increases the viscosity of the F-actin containing solution and polymerizes G-actin. The histone-actin bundles are relatively insensitive to increase of ionic strength, unlike other polycation, histatin, lysozyme, spermine and LL-37 induced F-actin bundles. The histone-actin bundles dissociate completely only in the presence of 300-400 mM NaCl. DNA, which competes with F-actin for histones, disassembles histone induced actin bundles. DNase1, which depolymerizes F- to G-actin, actively unbundles the H2A histone induced but slightly affects the histone mixture induced actin bundles. Cofilin decreases the amount of F-actin sedimented by low speed centrifugation, increases light scattering and viscosity of F-actin-histone mixture containing solutions and forms star like superstructures by copolymerizing G-actin with H2A histone. The results indicate that histones are tightly attached to F-actin by strong electrostatic and hydrophobic forces. Since both histones and F-actin are present in the sputum of patients with cystic fibrosis, therefore, the formation of the stable histone-actin bundles can contribute to the pathology of this disease by increasing the viscosity of the sputum. The actin-histone interaction in the nucleus might affect gene expression.

  16. The safety analysis and thermohydraulic methodologies for the power updating analyses in Spanish PWR plants; Methodologias de diseno termohidraulico y de analisis de seguridad en los aumentos de potencia de centrales PWR

    Energy Technology Data Exchange (ETDEWEB)

    Salesa, F.

    2014-02-01

    This article describes the Safety Analysis and Thermohydraulic methodologies used by ENUSA for the Power Updating analyses in Spanish PWR plants of Westinghouse design: Design tools have been developed over the first cycles resulting new correlations of DNB, fitted to the new fuel assemblies, new DNBR calculation methodology and other improvements in the design areas. Using these methodologies, the available margins between design and limit values are wider. These new margins have allowed to accomplish the design criteria under the new power updating operational conditions. (Author)

  17. An in vitro biomechanical comparison of anterior cruciate ligament reconstruction: single bundle versus anatomical double bundle techniques

    Directory of Open Access Journals (Sweden)

    Sandra Umeda Sasaki

    2008-01-01

    Full Text Available INTRODUCTION: Anterior cruciate ligament ruptures are frequent, especially in sports. Surgical reconstruction with autologous grafts is widely employed in the international literature. Controversies remain with respect to technique variations as continuous research for improvement takes place. One of these variations is the anatomical double bundle technique, which is performed instead of the conventional single bundle technique. More recently, there has been a tendency towards positioning the two bundles through double bone tunnels in the femur and tibia (anatomical reconstruction. OBJECTIVES: To compare, through biomechanical tests, the practice of anatomical double bundle anterior cruciate ligament reconstruction with a patellar graft to conventional single bundle reconstruction with the same amount of patellar graft in a paired experimental cadaver study. METHODS: Nine pairs of male cadaver knees ranging in age from 44 to 63 years were randomized into two groups: group A (single bundle and group B (anatomical reconstruction. Each knee was biomechanically tested under three conditions: intact anterior cruciate ligament, reconstructed anterior cruciate ligament, and injured anterior cruciate ligament. Maximum anterior dislocation, rigidity, and passive internal tibia rotation were recorded with knees submitted to a 100 N horizontal anterior dislocation force applied to the tibia with the knees at 30, 60 and 90 degrees of flexion. RESULTS: There were no differences between the two techniques for any of the measurements by ANOVA tests. CONCLUSION: The technique of anatomical double bundle reconstruction of the anterior cruciate ligament with bone-patellar tendon-bone graft has a similar biomechanical behavior with regard to anterior tibial dislocation, rigidity, and passive internal tibial rotation.

  18. Effects of different initial bundle tensioning strategies on the outcome of double-bundle ACL reconstruction: a cohort study

    Directory of Open Access Journals (Sweden)

    Muneta Takeshi

    2011-07-01

    Full Text Available Abstract Background This study was performed to investigate the effects of different strategies and initial tension applied to each one of the bundles, antero-medial (AM and postero-lateral (PL, on clinical outcome in double bundle (DB ACL reconstruction. Methods One hundred fifty-one primary unilateral DB ACL reconstructions performed by a single surgeon from 1994 through 2002 were included in the study with a follow-up of at least 24 months. They were divided in the following 3 groups: Group I - Higher initial tension applied manually in the AM bundle compared to PL. II - Higher tension applied in the PL bundle compared to AM. III - The 2 bundles were attempted to be equally tensioned. All fixations were performed in 30 degrees of flexion. Group I = 59 patients, group II = 53 patients and group III = 39 patients. The groups had no statistical differences concerning demographic distribution. Clinical outcome was retrospectively evaluated by use of knee range of motion, manual knee laxity tests, KT-1000, Lysholm knee scale, subjective recovery scale and sports performance recovery scale. The differences of data were analyzed among the three groups. Results Group I showed a significant extension deficit compared with groups II and III. ANOVA revealed a significant difference of anterior laxity measured by the KT-1000 (average KT difference of 2.1, 2.1 and 1.2 mm in Group I, II and III, respectively. A statistical difference was found among the three groups regarding subjective and sports performance recovery scales with Group II showing higher scores in recovery than Group I. Conclusions The current clinical study does not recommend manual maximum of initial tension applied to the anteromedial or posterolateral bundles with graft tension imbalance at 30 degrees of flexion in double-bundle ACL reconstruction to achieve a better clinical outcome.

  19. The 2-Hilbert space of a prequantum bundle gerbe

    Science.gov (United States)

    Bunk, Severin; Sämann, Christian; Szabo, Richard J.

    We construct a prequantum 2-Hilbert space for any line bundle gerbe whose Dixmier-Douady class is torsion. Analogously to usual prequantization, this 2-Hilbert space has the category of sections of the line bundle gerbe as its underlying 2-vector space. These sections are obtained as certain morphism categories in Waldorf’s version of the 2-category of line bundle gerbes. We show that these morphism categories carry a monoidal structure under which they are semisimple and abelian. We introduce a dual functor on the sections, which yields a closed structure on the morphisms between bundle gerbes and turns the category of sections into a 2-Hilbert space. We discuss how these 2-Hilbert spaces fit various expectations from higher prequantization. We then extend the transgression functor to the full 2-category of bundle gerbes and demonstrate its compatibility with the additional structures introduced. We discuss various aspects of Kostant-Souriau prequantization in this setting, including its dimensional reduction to ordinary prequantization.

  20. Improvements to Wire Bundle Thermal Modeling for Ampacity Determination

    Science.gov (United States)

    Rickman, Steve L.; Iannello, Christopher J.; Shariff, Khadijah

    2017-01-01

    Determining current carrying capacity (ampacity) of wire bundles in aerospace vehicles is critical not only to safety but also to efficient design. Published standards provide guidance on determining wire bundle ampacity but offer little flexibility for configurations where wire bundles of mixed gauges and currents are employed with varying external insulation jacket surface properties. Thermal modeling has been employed in an attempt to develop techniques to assist in ampacity determination for these complex configurations. Previous developments allowed analysis of wire bundle configurations but was constrained to configurations comprised of less than 50 elements. Additionally, for vacuum analyses, configurations with very low emittance external jackets suffered from numerical instability in the solution. A new thermal modeler is presented allowing for larger configurations and is not constrained for low bundle infrared emissivity calculations. Formulation of key internal radiation and interface conductance parameters is discussed including the effects of temperature and air pressure on wire to wire thermal conductance. Test cases comparing model-predicted ampacity and that calculated from standards documents are presented.

  1. Anatomy of an Oligourea Six-Helix Bundle.

    Science.gov (United States)

    Lombardo, Caterina M; Collie, Gavin W; Pulka-Ziach, Karolina; Rosu, Frederic; Gabelica, Valerie; Mackereth, Cameron D; Guichard, Gilles

    2016-08-24

    Non-natural synthetic oligomers that adopt well-defined secondary structures (i.e., foldamers) represent appealing components for the fabrication of bioinspired self-assembled architectures at the nanometer scale. Recently, peptidomimetic N,N'-linked oligourea helices have been designed de novo with the ability to fold into discrete helix bundles in aqueous conditions. In order to gain better insight into the determinants of oligourea helix bundle formation, we have investigated the sequence-to-structure relationship of an 11-mer oligourea previously shown to assemble into a six-helix bundle. Using circular dichroism, NMR spectroscopy, native mass-spectrometry and X-ray crystallography, we studied how bundle formation was affected by systematic replacement of the hydrophobic surface of the oligourea helix with either polar or different hydrophobic side chains. The molecular information gathered here has revealed several key requirements for foldamer bundle formation in aqueous conditions, and provides valuable insight toward the development of foldamer quaternary assemblies with improved (bio)physical properties and divergent topologies.

  2. Ecosystem service bundles for analyzing tradeoffs in diverse landscapes

    Science.gov (United States)

    Raudsepp-Hearne, C.; Peterson, G. D.; Bennett, E. M.

    2010-01-01

    A key challenge of ecosystem management is determining how to manage multiple ecosystem services across landscapes. Enhancing important provisioning ecosystem services, such as food and timber, often leads to tradeoffs between regulating and cultural ecosystem services, such as nutrient cycling, flood protection, and tourism. We developed a framework for analyzing the provision of multiple ecosystem services across landscapes and present an empirical demonstration of ecosystem service bundles, sets of services that appear together repeatedly. Ecosystem service bundles were identified by analyzing the spatial patterns of 12 ecosystem services in a mixed-use landscape consisting of 137 municipalities in Quebec, Canada. We identified six types of ecosystem service bundles and were able to link these bundles to areas on the landscape characterized by distinct social–ecological dynamics. Our results show landscape-scale tradeoffs between provisioning and almost all regulating and cultural ecosystem services, and they show that a greater diversity of ecosystem services is positively correlated with the provision of regulating ecosystem services. Ecosystem service-bundle analysis can identify areas on a landscape where ecosystem management has produced exceptionally desirable or undesirable sets of ecosystem services. PMID:20194739

  3. Syntheses of Nanostructure Bundles Based on Semiconducting Metal Silicides

    Science.gov (United States)

    Li, Wen; Ishikawa, Daisuke; Tatsuoka, Hirokazu

    2013-08-01

    A variety of nanostructure bundles and arrays based on semiconducting metal silicides have been synthesized using abundant and non-toxic starting materials. Three types of fabrication techniques of the nanostructure bundles or arrays, including direct growth, template synthesis using natural nanostructured materials and template synthesis using artificially fabricated nanostructured materials are demonstrated. CrSi2 nanowire bundles were directly grown by the exposure of Si substrates to CrCl2 vapor at atmospheric pressure. A hexagonal MoSi2 nanosheet, Mg2Si/MgO composite nanowire and Mg2Si nanowire bundles and MnSi1.7 nanowire array were synthesized using a MoS2 layered material, a SiOx nanofiber bundle, a Si nanowire array, and a Si nanowire array as the templates, respectively. Additionally, the fabrication phenomenon and structural properties of the nanostructured semiconducting metal silicides were investigated. These reactions provided the low-cost and controllable synthetic techniques to synthesize large scale and one-dimensional semiconducting metal silicides for thermoelectric applications.

  4. A prospective comparative study of clinical and functional outcomes between anatomic double bundle and single bundle hamstring grafts for arthroscopic anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Morey, Vivek M; Nag, Hira Lal; Chowdhury, Buddhadev; Sankineani, Sukesh Rao; Naranje, Sameer M

    2015-09-01

    Despite a number of studies comparing postoperative stability and function after anatomic single bundle and double bundle anterior cruciate ligament reconstruction, it remains unclear whether double bundle reconstruction has better functional outcome than single bundle anterior cruciate ligament reconstruction. To compare the subjective functional outcome as well as clinical stability in patients treated with either anatomic single bundle or anatomic double bundle anterior cruciate ligament (ACL) reconstruction. We hypothesized that there would be no difference in the postoperative functional outcome and clinical stability between anatomical double bundle anterior cruciate ligament reconstructions when compared to single bundle anterior cruciate ligament reconstructions. We prospectively followed 40 patients out of which, 20 patients were operated for anatomic single bundle ACL reconstruction and other 20 patients underwent anatomic double bundle ACL reconstruction. Patient evaluation using the laxity tests and outcome scales was done preoperatively and at 12, 24 and 48 months after the surgery. Clinical stability was assessed by Lachman test, Pivot shift test and Delhi active test. Functional outcome was assessed by International Knee Documentation Committee (IKDC), Lysholm and Modified Cincinnati scores. Patients in both groups were evaluated at regular intervals for a minimum period of 48 months (mean 51 months, range 48-56 months). For all subjective scores, double bundle group patients reported statistically significant higher scores compared to single bundle group patients. Graded stability results of the Lachman, and Pivot shift tests were significantly higher in the anatomically reconstructed double bundle patient group. We suggest that functional outcome and clinical stability may be better with anatomical double bundle anterior cruciate ligament reconstruction as compared to anatomical single bundle anterior cruciate ligament reconstruction. Copyright

  5. Uncertainty and Sensitivity Studies with TRACE-SUSA and TRACE-DAKOTA by Means of Transient BFBT Data

    Directory of Open Access Journals (Sweden)

    Wadim Jaeger

    2013-01-01

    Full Text Available In the present paper, an uncertainty and sensitivity study is performed for transient void fraction and pressure drop measurements. Two transients have been selected from the NUPEC BFBT database. The first one is a turbine trip without bypass and the second one is a trip of a recirculation pump. TRACE (version 5.0 patch 2 is used for the thermohydraulic study and SUSA and DAKOTA are used for the quantification of the model uncertainties and the evaluation of the sensitivities. As uncertain parameters geometrical values, hydraulic diameter, and wall roughness are considered while mass flow rate, power, pressure, and inlet subcooling (inlet temperature are chosen as boundary and input conditions. Since these parameters change with time, it is expected that the importance of them on pressure drop and void fraction will change, too. The results show that the pressure drop is mostly sensitive to geometrical variations like the hydraulic diameter and the form loss coefficient of the spacer grid. For low void fractions, the parameter of the highest importance is the inlet temperature/subcooling while at higher void fraction the power is also of importance.

  6. Single-Phase Bundle Flows Including Macroscopic Turbulence Model

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Jun; Yoon, Han Young [KAERI, Daejeon (Korea, Republic of); Yoon, Seok Jong; Cho, Hyoung Kyu [Seoul National University, Seoul (Korea, Republic of)

    2016-05-15

    To deal with various thermal hydraulic phenomena due to rapid change of fluid properties when an accident happens, securing mechanistic approaches as much as possible may reduce the uncertainty arising from improper applications of the experimental models. In this study, the turbulence mixing model, which is well defined in the subchannel analysis code such as VIPRE, COBRA, and MATRA by experiments, is replaced by a macroscopic k-e turbulence model, which represents the aspect of mathematical derivation. The performance of CUPID with macroscopic turbulence model is validated against several bundle experiments: CNEN 4x4 and PNL 7x7 rod bundle tests. In this study, the macroscopic k-e model has been validated for the application to subchannel analysis. It has been implemented in the CUPID code and validated against CNEN 4x4 and PNL 7x7 rod bundle tests. The results showed that the macroscopic k-e turbulence model can estimate the experiments properly.

  7. Symposium on Singularities, Representation of Algebras, and Vector Bundles

    CERN Document Server

    Trautmann, Günther

    1987-01-01

    It is well known that there are close relations between classes of singularities and representation theory via the McKay correspondence and between representation theory and vector bundles on projective spaces via the Bernstein-Gelfand-Gelfand construction. These relations however cannot be considered to be either completely understood or fully exploited. These proceedings document recent developments in the area. The questions and methods of representation theory have applications to singularities and to vector bundles. Representation theory itself, which had primarily developed its methods for Artinian algebras, starts to investigate algebras of higher dimension partly because of these applications. Future research in representation theory may be spurred by the classification of singularities and the highly developed theory of moduli for vector bundles. The volume contains 3 survey articles on the 3 main topics mentioned, stressing their interrelationships, as well as original research papers.

  8. Narrow muon bundles from muon pair production in rock

    CERN Document Server

    Kudryavtsev, V A; Spooner, N J C

    1999-01-01

    We revise the process of muon pair production by high-energy muons in rock using the recently published cross-section. The three- dimensional Monte Carlo code MUSIC has been used to obtain the characteristics of the muon bundles initiated via this process. We have compared them with those of conventional muon bundles initiated in the atmosphere and shown that large underground detectors, capable of collecting hundreds of thousands of multiple muon events, can discriminate statistically muon induced bundles from conventional ones. However, we find that the enhancement of the measured muon decoherence function over that predicted at small distances, recently reported by the MACRO experiment, cannot be explained by the effect of muon pair production alone, unless its cross-section is underestimated by a factor of 3. (20 refs).

  9. Product bundling as a customer loyalty strategy; Kundenbindung durch Produktbuendel

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, H.G. [Arthur Andersen Business Consulting GmbH, Duesseldorf (Germany)

    2000-12-01

    In the deregulated market in electricity, all marketers and energy-related service providers are competing not only for new customers, but also for customer loyalty. The article sets out concepts and strategies developed by a business consulting firm, for maintaing or enhancing customer loyalty in the end-use market segment, focusing on customized product bundling. A four-tier approach for product bundle development and implementation is discussed. (orig./CB) [German] Fuer Energieversorger und -dienstleister ergibt sich neben der Neukundengewinnung der strategische Zwang zur Bindung bestehender Kunden. An praktischen Ansaetzen fuer Privatkunden stehen neben Value-Added-Services und Incentives (Kundenclub, -karte) nicht zuletzt Produktbuendel (Bundles) zur Verfuegung. Zur erfolgreichen Entwicklung und Implementierung von Produktbuendeln wird ein vierphasiges Vorgehensmodell erlaeutert. (orig./CB)

  10. Measurement of secondary flow vortices on a rod bundle

    Energy Technology Data Exchange (ETDEWEB)

    Vonka, V.

    1988-02-01

    Secondary flow vortices in infinite rod bundles have been predicted by a number of theoretical analyses. Nevertheless experimental verification was difficult, since the magnitude of the secondary velocities appeared to be less than the accuracy of the experimental techniques used. Only indications of the maximum velocity magnitude have been available but no report on successful direct measurement is known to the author. At ECN, laser Doppler velocimetry is successfully used for measurement of secondary flow vortices in two regular subchannels of a triangularly arranged bare rod bundle with pitch-to-diameter ratio P/D-1.3 under the Reynolds number conditions 60,000 and 175,000. One single secondary vortex, having the average tangential velocity slightly less than 0.1% of the mean bulk velocity, is resolved per minimum symmetry sector of the bundle geometry. Ensemble averages are made to obtain quantitative description of the vortex and to form a data base for comparison with calculations.

  11. Gradient Bundle Analysis: A Full Topological Approach to Chemical Bonding

    CERN Document Server

    Morgenstern, Amanda

    2016-01-01

    The "chemical bond" is a central concept in molecular sciences, but there is no consensus as to what a bond actually is. Therefore, a variety of bonding models have been developed, each defining the structure of molecules in a different manner with the goal of explaining and predicting chemical properties. This thesis describes the initial development of gradient bundle analysis (GBA), a chemical bonding model that creates a high resolution picture of chemical interactions within the charge density framework. GBA is based on concepts from the quantum theory of atoms in molecules (QTAIM), but uses a more complete picture of the topology and geometry of the electron charge density to understand and predict bonding interactions. Gradient bundles are defined as volumes bounded by zero-flux surfaces (ZFSs) in the gradient of the charge density with well-defined energies. The structure of gradient bundles provides an avenue for detecting the locations of valence electrons, which correspond to reactive regions in a ...

  12. Failure of a MEA reclaimer tube bundle due to corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Shaban, H.; Abdo, M.S.E.; Lal, D.P.

    1988-08-01

    The removal of sulphur compounds from natural gas used in ammonia production is carried out by scrubbing with monoethanol amine (MEA). To avoid build up of corrosion and degradation products, a portion of the circulating MEA solution is passed through a reclaimer. This is essentially a kettle-type reboiler with a tube bundle made of 316L stainless steel. Occasional failures of the tube bundle due to pitting corrosion have been reported. It is suggested that the excessive pitting corrosion observed on the upper rows of the tube bundle could be partly due to high steam temperature but mainly due to the liquid level falling below the tubes leaving an accumulation of corrosive degradation products on the exposed surfaces, normally these corrosive products remain diluted in the MEA solution and cause little corrosion of the covered tubes. Their concentration on the dry upper layers of the hot metal tubes, however, leads to excessive corrosion. (U.K.).

  13. Designing cooperatively folded abiotic uni- and multimolecular helix bundles

    Science.gov (United States)

    de, Soumen; Chi, Bo; Granier, Thierry; Qi, Ting; Maurizot, Victor; Huc, Ivan

    2018-01-01

    Abiotic foldamers, that is foldamers that have backbones chemically remote from peptidic and nucleotidic skeletons, may give access to shapes and functions different to those of peptides and nucleotides. However, design methodologies towards abiotic tertiary and quaternary structures are yet to be developed. Here we report rationally designed interactional patterns to guide the folding and assembly of abiotic helix bundles. Computational design facilitated the introduction of hydrogen-bonding functionalities at defined locations on the aromatic amide backbones that promote cooperative folding into helix-turn-helix motifs in organic solvents. The hydrogen-bond-directed aggregation of helices not linked by a turn unit produced several thermodynamically and kinetically stable homochiral dimeric and trimeric bundles with structures that are distinct from the designed helix-turn-helix. Relative helix orientation within the bundles may be changed from parallel to tilted on subtle solvent variations. Altogether, these results prefigure the richness and uniqueness of abiotic tertiary structure behaviour.

  14. The concept of double bundle ACL simulation with a single bundle patellar tendon graft. A cadaveric feasibility study.

    Science.gov (United States)

    Jacobi, Matthias; Magnussen, Robert A; Villa, Vincent; Demey, Guillaume; Neyret, Philippe

    2012-06-07

    There is significant interest in the restoration of the double-bundle anatomy of the native ACL when performing ACL reconstruction. Possible techniques include those utilizing two separate grafts with independent tunnels and those that attempt to mimic this anatomy with a single graft and fewer tunnels. Many of the latter techniques require specific instrumentation and are technically challenging. We demonstrate that the double-bundle anatomy of the native ACL can theoretically be mimicked by a single-bundle reconstruction. We performed single bundle ACL reconstruction with a bone-patellar tendon-bone (BTB) graft in two cadaveric knees. Both grafts were placed to mimic the native ACL footprints - one reconstruction was performed with rectangular bone blocks and oval tunnels and one was performed utilizing a standard BTB graft and round tunnels. Qualitative assessment of graft behavior was made as the knees were taken through a range of motion. The ACL graft was able to qualitatively mimic the behavior of the native ACL in both knees provided the bone blocks were correctly orientated. ACL reconstruction with a single BTB graft can qualitatively mimic the behavior of the two bundles of the native ACL. The key to ensuring this behavior was noted to be appropriate orientation of the graft in the tunnels. Quantitative biomechanical investigations are necessary to evaluate the impact of graft orientation on function.

  15. The concept of double bundle ACL simulation with a single bundle patellar tendon graft. A cadaveric feasibility study

    Directory of Open Access Journals (Sweden)

    Jacobi Matthias

    2012-06-01

    Full Text Available Abstract Background There is significant interest in the restoration of the double-bundle anatomy of the native ACL when performing ACL reconstruction. Possible techniques include those utilizing two separate grafts with independent tunnels and those that attempt to mimic this anatomy with a single graft and fewer tunnels. Many of the latter techniques require specific instrumentation and are technically challenging. We demonstrate that the double-bundle anatomy of the native ACL can theoretically be mimicked by a single-bundle reconstruction. Methods We performed single bundle ACL reconstruction with a bone-patellar tendon-bone (BTB graft in two cadaveric knees. Both grafts were placed to mimic the native ACL footprints – one reconstruction was performed with rectangular bone blocks and oval tunnels and one was performed utilizing a standard BTB graft and round tunnels. Qualitative assessment of graft behavior was made as the knees were taken through a range of motion. Results The ACL graft was able to qualitatively mimic the behavior of the native ACL in both knees provided the bone blocks were correctly orientated. Conclusions ACL reconstruction with a single BTB graft can qualitatively mimic the behavior of the two bundles of the native ACL. The key to ensuring this behavior was noted to be appropriate orientation of the graft in the tunnels. Quantitative biomechanical investigations are necessary to evaluate the impact of graft orientation on function.

  16. Mechanical Stresses and Forces in Stereocilia Bundles of Inner and Outer Hair Cells

    Science.gov (United States)

    Mueller, R.; Maier, H.; Boehnke, F.; Arnold, W.

    2003-02-01

    The precise mechanism of mechanoelectrical transduction in stereocilia bundles is not known. It is very difficult to measure the extremely small stresses, which occur at the stereocilia bundles. Therefore we developed 3-D finite element models of stereocilia bundles (guinea pig) to obtain quantitative results. The stereocilia bundles of the outer hair cells show a characteristic W-form. Therefore, it is interesting to compare the mechanical behavior of the stereocilia bundle of an outer hair cell with that of an inner hair cell with its linear arrangement. Our analysis provides estimates of forces and stresses on the transducer channels of mammalian hair bundles, although the model does not include active mechanisms yet.

  17. The Analysis of SBWR Critical Power Bundle Using Cobrag Code

    Directory of Open Access Journals (Sweden)

    Yohannes Sardjono

    2013-03-01

    Full Text Available The coolant mechanism of SBWR is similar with the Dodewaard Nuclear Power Plant (NPP in the Netherlands that first went critical in 1968. The similarity of both NPP is cooled by natural convection system. These coolant concept is very related with same parameters on fuel bundle design especially fuel bundle length, core pressure drop and core flow rate as well as critical power bundle. The analysis was carried out by using COBRAG computer code. COBRAG computer code is GE Company proprietary. Basically COBRAG computer code is a tool to solve compressible three-dimensional, two fluid, three field equations for two phase flow. The three fields are the vapor field, the continuous liquid field, and the liquid drop field. This code has been applied to analyses model flow and heat transfer within the reactor core. This volume describes the finitevolume equations and the numerical solution methods used to solve these equations. This analysis of same parameters has been done i.e.; inlet sub cooling 20 BTU/lbm and 40 BTU/lbm, 1000 psi pressure and R-factor is 1.038, mass flux are 0.5 Mlb/hr.ft2, 0.75 Mlb/hr.ft2, 1.00 Mlb/hr.ft2 and 1.25 Mlb/hr.ft2. Those conditions based on history operation of some type of the cell fuel bundle line at GE Nuclear Energy. According to the results, it can be concluded that SBWR critical power bundle is 10.5 % less than current BWR critical power bundle with length reduction of 12 ft to 9 ft.

  18. Learning Bundled Care Opportunities from Electronic Medical Records.

    Science.gov (United States)

    Chen, You; Kho, Abel N; Liebovitz, David; Ivory, Catherine; Osmundson, Sarah; Bian, Jiang; Malin, Bradley A

    2017-11-22

    The traditional fee-for-service approach to healthcare can lead to the management of a patient's conditions in a siloed manner, inducing various negative consequences. It has been recognized that a bundled approach to healthcare - one that manages a collection of health conditions together - may enable greater efficacy and cost savings. However, it is not always evident which sets of conditions should be managed in a bundled manner. In this study, we investigate if a data-driven approach can automatically learn potential bundles. We designed a framework to infer health condition collections (HCCs) based on the similarity of their clinical workflows, according to electronic medical record (EMR) utilization. We evaluated the framework with data from over 16,500 inpatient stays from Northwestern Memorial Hospital in Chicago, Illinois. The plausibility of the inferred HCCs for bundled care was assessed through an online survey of a panel of five experts, whose responses were analyzed via an analysis of variance (ANOVA) at a 95% confidence level. We further assessed the face validity of the HCCs using evidence in the published literature. The framework inferred four HCCs, indicative of 1) fetal abnormalities, 2) late pregnancies, 3) prostate problems, and 4) chronic diseases, with congestive heart failure featuring prominently. Each HCC was substantiated with evidence in the literature and was deemed plausible for bundled care by the experts at a statistically significant level. The findings suggest that an automated EMR data-driven framework conducted can provide a basis for discovering bundled care opportunities. Still, translating such findings into actual care management will require further refinement, implementation, and evaluation. Copyright © 2017. Published by Elsevier Inc.

  19. Transient Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Analytical theory of transient heat conduction.Fourier's law. General heat conducation equation. Thermal diffusivity. Biot and Fourier numbers. Lumped analysis and time constant. Semi-infinite body: fixed surface temperature, convective heat transfer at the surface, or constant surface heat flux...

  20. Transient cavitation in pipelines

    NARCIS (Netherlands)

    Kranenburg, C.

    1974-01-01

    The aim of the present study is to set up a one-dimensional mathematical model, which describes the transient flow in pipelines, taking into account the influence of cavitation and free gas. The flow will be conceived of as a three-phase flow of the liquid, its vapour and non-condensible gas. The

  1. Fast bundle algorithm for multiple-instance learning.

    Science.gov (United States)

    Bergeron, Charles; Moore, Gregory; Zaretzki, Jed; Breneman, Curt M; Bennett, Kristin P

    2012-06-01

    We present a bundle algorithm for multiple-instance classification and ranking. These frameworks yield improved models on many problems possessing special structure. Multiple-instance loss functions are typically nonsmooth and nonconvex, and current algorithms convert these to smooth nonconvex optimization problems that are solved iteratively. Inspired by the latest linear-time subgradient-based methods for support vector machines, we optimize the objective directly using a nonconvex bundle method. Computational results show this method is linearly scalable, while not sacrificing generalization accuracy, permitting modeling on new and larger data sets in computational chemistry and other applications. This new implementation facilitates modeling with kernels.

  2. Cellulosic Fibers: Effect of Processing on Fiber Bundle Strength

    DEFF Research Database (Denmark)

    Thygesen, Anders; Madsen, Bo; Thomsen, Anne Belinda

    2011-01-01

    A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding, and cotto......A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding...

  3. On a Lie Algebraic Characterization of Vector Bundles

    Directory of Open Access Journals (Sweden)

    Pierre B.A. Lecomte

    2012-01-01

    Full Text Available We prove that a vector bundle π: E→M is characterized by the Lie algebra generated by all differential operators on E which are eigenvectors of the Lie derivative in the direction of the Euler vector field. Our result is of Pursell-Shanks type but it is remarkable in the sense that it is the whole fibration that is characterized here. The proof relies on a theorem of [Lecomte P., J. Math. Pures Appl. (9 60 (1981, 229-239] and inherits the same hypotheses. In particular, our characterization holds only for vector bundles of rank greater than 1.

  4. Compressive Transient Imaging

    KAUST Repository

    Sun, Qilin

    2017-04-01

    High resolution transient/3D imaging technology is of high interest in both scientific research and commercial application. Nowadays, all of the transient imaging methods suffer from low resolution or time consuming mechanical scanning. We proposed a new method based on TCSPC and Compressive Sensing to achieve a high resolution transient imaging with a several seconds capturing process. Picosecond laser sends a serious of equal interval pulse while synchronized SPAD camera\\'s detecting gate window has a precise phase delay at each cycle. After capturing enough points, we are able to make up a whole signal. By inserting a DMD device into the system, we are able to modulate all the frames of data using binary random patterns to reconstruct a super resolution transient/3D image later. Because the low fill factor of SPAD sensor will make a compressive sensing scenario ill-conditioned, We designed and fabricated a diffractive microlens array. We proposed a new CS reconstruction algorithm which is able to denoise at the same time for the measurements suffering from Poisson noise. Instead of a single SPAD senor, we chose a SPAD array because it can drastically reduce the requirement for the number of measurements and its reconstruction time. Further more, it not easy to reconstruct a high resolution image with only one single sensor while for an array, it just needs to reconstruct small patches and a few measurements. In this thesis, we evaluated the reconstruction methods using both clean measurements and the version corrupted by Poisson noise. The results show how the integration over the layers influence the image quality and our algorithm works well while the measurements suffer from non-trival Poisson noise. It\\'s a breakthrough in the areas of both transient imaging and compressive sensing.

  5. Study of thermophysical and thermohydraulic properties of sodium for fast sodium cooled reactors; Estudio de las propiedades termofisicas y termohidraulicas del sodio para reactores rapidos enfriados por sodio

    Energy Technology Data Exchange (ETDEWEB)

    Vega R, A. K.; Espinosa P, G. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, San Rafael Atlixco No. 186, Col. Vicentina, 09340 Ciudad de Mexico (Mexico); Gomez T, A. M., E-mail: a.karen.vr@gmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2016-09-15

    The importance of liquid sodium lies in its use as a coolant for fast reactors, but why should liquid metal be used as a coolant instead of water? Water is difficult to use as a coolant for a fast nuclear reactor because its acts as a neutron moderator, that is, stop the fast neutrons and converts them to thermal neutrons. Nuclear reactors such as the Pressurized Water Reactor or the Boiling Water Reactor are thermal reactors, which mean they need thermal neutrons for their operation. However, is necessary for fast reactors to conserve as much fast neutrons, so that the liquid metal coolants that do have this capability are implemented. Sodium does not need to be pressurized, its low melting point and its high boiling point, higher than the operating temperature of the reactor, make it an adequate coolant, also has a high thermal conductivity, which is necessary to transfer thermal energy and its viscosity is close to that of the water, which indicates that is an easily transportable liquid and does not corrode the steel parts of the reactor. This paper presents a brief state of the art of the rapid nuclear reactors that operated and currently operate, as well as projects in the door in some countries; types of nuclear reactors which are cooled by liquid sodium and their operation; the mathematical models for obtaining the properties of liquid sodium in a range of 393 to 1673 Kelvin degrees and a pressure atmosphere. Finally a program is presented in FORTRAN named Thermo-Sodium for the calculation of the properties, which requires as input data the Kelvin temperature in which the liquid sodium is found and provides at the user the thermo-physical and thermo-hydraulic properties for that data temperature. Additional to this the user is asked the Reynolds number and the hydraulic diameter in case of knowing them, and in this way the program will provide the value of the convective coefficient and that of the dimensionless numbers: Nusselt, Prandtl and Peclet. (Author)

  6. Geophysical investigation and monitoring of thermo-hydraulic conditions of closed talik and icing of the Kuuguluk River at Salluit, northern Quebec, Canada

    Science.gov (United States)

    Fortier, R.; Lemieux, J. M.; Molson, J. W. H.; Therrien, R.; Ouellet, M.

    2016-12-01

    The Inuit community of Salluit in northern Quebec, Canada, is located in the continuous permafrost zone characterized by a mean annual air temperature (MAAT) of -8.0 °C over the period from 1981 to 2010. In such cold environment, it is challenging to find a sustainable supply of water. A well drilled in fractured bedrock and located in a closed talik underneath the Kuuguluk River is used as a source of drinking water by the municipality of Salluit. To verify the lateral extent of the closed talik beneath the floodplain of Kuuguluk River, a geophysical investigation using ground penetrating radar (GPR) profiling and capacitively-coupled electrical resistivity tomography (ERT) was undertaken in spring 2011. Moreover, a mooring with water level and temperature dataloggers in the river was installed over the 2015-2016 period to assess the thermo-hydraulic conditions of the river bed. The icing which forms each year in the floodplain of Kuuguluk River was used in spring 2011 as a bridge to cross over the river and move along the geophysical equipment. Three thaw bulbs in the ice-rich permafrost of the floodplain were inferred from low resistivity anomalies in the model of electrical resistivity. The largest bulb is about 40 m wide and 14 m thick. According to the mooring results, the mean annual temperature of the river bed (MATRB) was 1.4 °C in 2015-2016 while the MAAT was -7.1 °C. This MATRB above 0 °C is due to the heat storage of running surface water in the river bed and the suprapermafrost water flow in the closed talik. River bed temperature below 0 °C and as low as -3 °C from October 10th 2015 to November 20th 2015 and from January 23rd to April 17th 2016 were recorded. The spring freshet occurred on June 24th2016. Outside these periods, the river bed temperature stayed remarkably stable at 0.05 °C in winter time. While the water level in the Kuuguluk River varies from 0.4 to 1.0 m in summer time following the precipitation events, the water pressure can

  7. 3D thermohydraulic modeling of the coupling of surface water bodies to the subsurface below the major urban center of Berlin

    Science.gov (United States)

    Frick, Maximilian; Scheck-Wenderoth, Magdalena; Cacace, Mauro; Schneider, Michael

    2017-04-01

    This study aims at a better understanding of the present-day thermal and hydraulic configuration below the major urban center of Berlin, capital city of Germany. The study area is located in the Northeast German Basin, showing an infill of several kilometers of sediments. Herein, the shallow sedimentary succession is made up of a sequence of alternating aquifers and aquitards, most importantly the local aquitard of the Rupelian clay. This geological unit represents a natural barrier between the deeper saline aquifers and the shallow fresh water aquifers from whom Berlin produces 100% of its drinking water. Additionally, the shallow thermal and hydraulic configuration has been anthropogenically overprinted which may also influence deeper domains to some extent. In this study we make use of 3D thermohydraulic models of the subsurface, focusing on the coupling of surface water bodies to the underground, based on newly available hydraulic data integrated into a 3D hydrogeological model. The results of the study show, that the coupling of surface water bodies and groundwater might lead to significant modifications of predicted subsurface temperatures and fluid flow field. These modifications are most prominent, where differences in hydraulic head between surface water bodies and the adjacent aquifers are highest. Consequently, the predicted surface to groundwater flow field differs most in these areas and it also results in differences in predicted temperatures as a consequence of advective heat transport. Quantitatively, the presence of major lakes may account for temperature differences up to 5°C, while considering rivers only accounts for modifications up to 1°C. Additionally, the models created in this study set up a basis for future thermohaline simulations as saline groundwater may represent a threat to drinking water supply. First results from the models run in this study already indicate, that uprising heated water from deeper domains may rise to shallow

  8. EXTERNAL VERIFICATION OF THE BUNDLE ADJUSTMENT IN PHOTOGRAMMETRIC SOFTWARE USING THE DAMPED BUNDLE ADJUSTMENT TOOLBOX

    Directory of Open Access Journals (Sweden)

    N. Börlin

    2016-06-01

    Full Text Available The aim of this paper is to investigate whether the Matlab-based Damped Bundle Adjustment Toolbox (DBAT can be used to provide independent verification of the BA computation of two popular software—PhotoModeler (PM and PhotoScan (PS. For frame camera data sets with lens distortion, DBAT is able to reprocess and replicate subsets of PM results with high accuracy. For lens-distortion-free data sets, DBAT can furthermore provide comparative results between PM and PS. Data sets for the discussed projects are available from the authors. The use of an external verification tool such as DBAT will enable users to get an independent verification of the computations of their software. In addition, DBAT can provide computation of quality parameters such as estimated standard deviations, correlation between parameters, etc., something that should be part of best practice for any photogrammetric software. Finally, as the code is free and open-source, users can add computations of their own.

  9. Innovative Defense Acquisition Concept Deployer Equipment Bundle (DEB)

    Science.gov (United States)

    2017-06-01

    METHODOLOGY This project reviewed a substantial amount of literature , to include applicable concept plans, memorandums, cost benefit analyses, organizational...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA MBA PROFESSIONAL REPORT INNOVATIVE DEFENSE ACQUISITION CONCEPT DEPLOYER...ACQUISITION CONCEPT DEPLOYER EQUIPMENT BUNDLE (DEB) 5. FUNDING NUMBERS 6. AUTHOR(S) Frederic Albesa, Isaac J. Ortman, and Stephen F. Kirouac 7

  10. Temperature response of bundle-sheath conductance in maize leaves

    NARCIS (Netherlands)

    Yin, Xinyou; Putten, Van Der Peter E.L.; Struik, Paul C.; Driever, Steven M.

    2016-01-01

    A small bundle-sheath conductance (g bs) is essential for the C4 CO2-concentrating mechanism to suppress photorespiration effectively. To predict the productivity of C4 crops accurately under global warming, it is necessary to examine whether and how g

  11. Quillen bundle and geometric prequantization of non-abelian ...

    Indian Academy of Sciences (India)

    E-mail: rkmn@mri.ernet.in; rukmini.dey@gmail.com; smr@bose.res.in. MS received 7 September 2010; revised 23 November 2010. Abstract. In this paper we prequantize the moduli space of non-abelian vortices. We explicitly calculate the symplectic form arising from L2 metric and we construct a prequantum line bundle ...

  12. Multicell slug flow heat transfer analysis of finite LMFBR bundles

    Energy Technology Data Exchange (ETDEWEB)

    Yeung, M.K.; Wolf, L.

    1978-12-01

    An analytical two-dimensional, multi-region, multi-cell technique has been developed for the thermal analysis of LMFBR rod bundles. Local temperature fields of various unit cells were obtained for 7, 19, and 37-rod bundles of different geometries and power distributions. The validity of the technique has been verified by its excellent agreement with the THTB calculational result. By comparing the calculated fully-developed circumferential clad temperature distribution with those of the experimental measurements, an axial correction factor has been derived to account for the entrance effect for practical considerations. Moreover, the knowledge of the local temperature field of the rod bundle leads to the determination of the effective mixing lengths L/sub ij/ for adjacent subchannels of various geometries. It was shown that the implementation of the accurately determined L/sub ij/ into COBRA-IIIC calculations has fairly significant effects on intersubchannel mixing. In addition, a scheme has been proposed to couple the 2-D distributed and lumped parameter calculation by COBRA-IIIC such that the entrance effect can be implanted into the distributed parameter analysis. The technique has demonstrated its applicability for a 7-rod bundle and the results of calculation were compared to those of three-dimensional analyses and experimental measurements.

  13. Metallic/semiconducting ratio of carbon nanotubes in a bundle ...

    Indian Academy of Sciences (India)

    SWCNTs) in a bundle by resonant Raman spectroscopy. The calculation has been done for the three peak positions in radial breathing mode (RBM) spectra obtained by using a laser excitation wavelength () of 633 nm from He–Ne laser on ...

  14. The fibre bundle anatomy of human cruciate ligaments

    NARCIS (Netherlands)

    Mommersteeg, T. J.; Kooloos, J. G.; Blankevoort, L.; Kauer, J. M.; Huiskes, R.; Roeling, F. Q.

    1995-01-01

    The cruciate ligaments of the knee consist of numerous fascicles, groups of which comprise fibre bundles. The stabilising function of these ligaments is established by changes in the lengths and orientations of the fascicles. Understanding the function of knee ligaments thus requires an

  15. Metabolic profiling of laser microdissected vascular bundles of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Fiehn Oliver

    2005-08-01

    Full Text Available Abstract Background Laser microdissection is a useful tool for collecting tissue-specific samples or even single cells from animal and plant tissue sections. This technique has been successfully employed to study cell type-specific expression at the RNA, and more recently also at the protein level. However, metabolites were not amenable to analysis after laser microdissection, due to the procedures routinely applied for sample preparation. Using standard tissue fixation and embedding protocols to prepare histological sections, metabolites are either efficiently extracted by dehydrating solvents, or washed out by embedding agents. Results In this study, we used cryosectioning as an alternative method that preserves sufficient cellular structure while minimizing metabolite loss by excluding any solute exchange steps. Using this pre-treatment procedure, Arabidopsis thaliana stem sections were prepared for laser microdissection of vascular bundles. Collected samples were subsequently analyzed by gas chromatography-time of flight mass spectrometry (GC-TOF MS to obtain metabolite profiles. From 100 collected vascular bundles (~5,000 cells, 68 metabolites could be identified. More than half of the identified metabolites could be shown to be enriched or depleted in vascular bundles as compared to the surrounding tissues. Conclusion This study uses the example of vascular bundles to demonstrate for the first time that it is possible to analyze a comprehensive set of metabolites from laser microdissected samples at a tissue-specific level, given that a suitable sample preparation procedure is used.

  16. AdS 3-manifolds and Higgs bundles

    DEFF Research Database (Denmark)

    Alessandrini, Daniele; Li, Qiongling

    2017-01-01

    In this paper we investigate the relationships between closed AdS $3$-manifolds and Higgs bundles. We have a new way to construct AdS structures that allows us to see many of their properties explicitly, for example we can recover the very recent formula by Tholozan for their volume. We give natu...

  17. Heat transfer and fluid friction in bundles of twisted tubes

    Science.gov (United States)

    Dzyubenko, B. V.; Dreitser, G. A.

    1986-06-01

    The results of heat-transfer and friction studies in bundles of twisted tubes and rods with spiral wire-wrap spacers are analyzed, and recommendations are given for calculating the heat-transfer coefficient in heat exchangers using twisted tubes.

  18. Fission yeast Scp3 potentially maintains microtubule orientation through bundling.

    Directory of Open Access Journals (Sweden)

    Kanako Ozaki

    Full Text Available Microtubules play important roles in organelle transport, the maintenance of cell polarity and chromosome segregation and generally form bundles during these processes. The fission yeast gene scp3+ was identified as a multicopy suppressor of the cps3-81 mutant, which is hypersensitive to isopropyl N-3-chlorophenylcarbamate (CIPC, a poison that induces abnormal multipolar spindle formation in higher eukaryotes. In this study, we investigated the function of Scp3 along with the effect of CIPC in the fission yeast Schizosaccharomyces pombe. Microscopic observation revealed that treatment with CIPC, cps3-81 mutation and scp3+ gene deletion disturbed the orientation of microtubules in interphase cells. Overexpression of scp3+ suppressed the abnormal orientation of microtubules by promoting bundling. Functional analysis suggested that Scp3 functions independently from Ase1, a protein largely required for the bundling of the mitotic spindle. A strain lacking the ase1+ gene was more sensitive to CIPC, with the drug affecting the integrity of the mitotic spindle, indicating that CIPC has a mitotic target that has a role redundant with Ase1. These results suggested that multiple systems are independently involved to ensure microtubule orientation by bundling in fission yeast.

  19. MYOCARDIAL DEFORMATION AND COMPLETE LEFT BUNDLE BRANCH BLOCK

    Directory of Open Access Journals (Sweden)

    E. N. Pavlyukova

    2015-12-01

    Full Text Available Tissue Doppler imaging is evolving as a useful echocardiographic tool for quantitative assessment of left ventricular systolic and diastolic function. Over the last 10 years, myocardial deformation imaging has become possible initially with tissue Doppler , and more recently with myocardial speckle-tracking using 2D echocardiography. Unlike simple tissue velocity measurements, deformation measurements are specific for the region of interest. Strain rate or strain measurements have been used as sensitive indicators for subclinical diseases, and it is the most widely used tool to assess mechanical dyssynchrony. Left bundle branch block is a frequent, etiologically heterogeneous, clinically hostile and diagnostically challenging entity. About 2% of patients underwent cardiac stress testing show stable or intermittent left bundle branch block. Presence of left bundle branch block is associated with a lower and slower diastolic coronary flow velocity especially during hyperemia. Stress echocardiography is the best option for the diagnosis of ischemic heart disease, albeit specificity and sensitivity reduce in patients with left bundle branch block in the territory of left anterior descending artery in presence of initial septum dyskinesia.

  20. Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction

    NARCIS (Netherlands)

    Hofbauer, Marcus; Muller, Bart; Wolf, Megan; Forsythe, Brian; Fu, Freddie H.

    2013-01-01

    Over the past decade, intense research of the function of the 2 distinct bundles, the anteromedial and posterolateral, of the anterior cruciate ligament (ACL) has led to pronounced changes in the technical concepts of ACL reconstruction. Recently, the renewed focus of ACL reconstruction has been to

  1. Reminiscences Of The First His Bundle Electrography In India

    Directory of Open Access Journals (Sweden)

    Nambiar C.A

    2002-04-01

    Full Text Available Dr Onkar Narula was making a huge wave those days with his work on His Bundle Electrocardiography and Corrected Sinus Node Recovery Time. He visited us in late 1972 or early 1973,probably the latter date. Till then venous catheterizations (including pacing were done by open cut down. I remember the first time we used venous sheath through right femoral vein. Dr Bhatia was the operator and I was assisting him and Dr Savithri Srivasthava was the senior Registrar. With Dr Narula showing the way we did the first His Bundle Recording and I analysed the whole roll manually as was the method those days. We had to improvise a junction box as the recording equipment did not have a proper connecting accessory at that time. After Dr Narula left we did His Bundle recording on many more patients and undertook a study. This was published as: Effect of acute digitalization on His Bundle Intervals and Corrected Sinus Node Recovery Time in young adults.M.L.Bhatia,C.Ashokan Nambiar,S.Shrivastava and Sujoy B.Roy: Indian Heart Journal:Vol-2:1977.1The article was received for publication on 29/11/1973 as acknowledged underneath, but strangely it took a long time to come in print. I have preserved some of the cath rolls and reprint of the article.

  2. Frobenius pull backs of vector bundles in higher dimensions

    Indian Academy of Sciences (India)

    ... of a Frobenius pull back of is a refinement of the Frobenius pull back of the Harder–Narasimhan filtration of , provided there is a lower bound on the characteristic (in terms of rank of and the slope of the destabilizing sheaf of the cotangent bundle of ). We also recall some examples, due to Raynaud and Monsky, ...

  3. The Roach muscle bundle and umbilical cord coiling

    NARCIS (Netherlands)

    de Laat, Monique W. M.; Nikkels, Peter G. J.; Franx, Arie; Visser, Gerard H. A.

    2007-01-01

    To determine if presence of the Roach muscle, a small muscle bundle lying just beside the umbilical artery, contributes to umbilical cord coiling. 251 umbilical cords were examined. The umbilical coiling index (UCI) was calculated as the number of coils divided by the cord length in cm. Cords were

  4. Subanalytic bundles and tubular neighbourhoods of zero-loci

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. We introduce the natural and fairly general notion of a subanalytic bundle. (with a finite dimensional vector space P of sections) on a subanalytic subset X of a real analytic manifold M, and prove that when M is compact, there is a Baire subset U of sections in P whose zero-loci in X have tubular neighbourhoods, ...

  5. On the classification of complex vector bundles of stable rank

    Indian Academy of Sciences (India)

    This classification becomes more effective on generalized flag manifolds, where the Lie algebra formalism and concrete integrability conditions describe in constructive terms the Chern classes of a vector bundle. ... Since deceased; Mathematics Department, University of California, Santa Barbara, CA 93106, USA ...

  6. On infinitesimal conformal transformations of the tangent bundles ...

    Indian Academy of Sciences (India)

    The metric. ˜g, which is called a synectic lift of the Riemannian metric g, was introduced by Talantova and Shirokov [4] to study the differential geometry of tangent bundles of Riemannian manifolds (for details, also see [5]). Their paper is concerned with the geometry of the space of n dual variables. The concept of a dual ...

  7. On the classification of complex vector bundles of stable rank

    Indian Academy of Sciences (India)

    According to previous observations, this would imply (under the above torsion conditions) a classification of all rank r complex vector bundles on X, for stable rank r ≥ n/2. A few partial answers to this question are known. For instance, a classical result of. Wu asserts that any couple of cohomology classes (c1,c2) ∈ H2(X, ...

  8. Transient FDTD simulation validation

    OpenAIRE

    Jauregui Tellería, Ricardo; Riu Costa, Pere Joan; Silva Martínez, Fernando

    2010-01-01

    In computational electromagnetic simulations, most validation methods have been developed until now to be used in the frequency domain. However, the EMC analysis of the systems in the frequency domain many times is not enough to evaluate the immunity of current communication devices. Based on several studies, in this paper we propose an alternative method of validation of the transients in time domain allowing a rapid and objective quantification of the simulations results.

  9. Transient cerebral ischemia.

    OpenAIRE

    Cusimano, M D; Ameli, F M

    1989-01-01

    Stroke is a major cause of disability and death in North America. About 30% to 40% of patients with stroke have had transient ischemic attacks (TIAs). The recognition and treatment of TIAs and possibly of asymptomatic stenoses of the carotid arteries may be beneficial in preventing stroke. We review the epidemiologic features, natural history, pathogenetic features, clinical presentation, methods of investigation and management of patients with TIAs.

  10. A case of ‘Masquerading’ bundle branch block: A forgotten concept

    OpenAIRE

    Dinesh Choudhary; Narayanan Namboodiri; Jaganmohan A. Tharakan

    2014-01-01

    ‘Masquerading’ bundle branch block (right bundle branch block in the precordial leads with left bundle branch block in frontal leads and left axis deviation) is seen most commonly with coronary artery disease and hypertension. No definite explanation is available so far for these changes. We are presenting a case of rare congenital intranuclear inclusion myopathy with congestive heart failure and ‘Masquerading’ bundle branch block in ECG.

  11. Structural Causes of Right Bundle Branch Block?Time for a Closer Look?

    OpenAIRE

    Ker, James

    2010-01-01

    Right bundle branch block is an electrocardiographic phenomenon with specific criteria. Currently, two specific forms of right bundle branch block are acknowledged, a proximal and a distal variant. A vast array of pathologies can cause proximal, distal or even combined forms of right bundle branch block. In this study it is suggested that a third type of right bundle branch block exist: one caused by a subaortic muscular tendon in the left ventricle, leading to an increased velocity of conduc...

  12. Transient Astrophysics Probe

    Science.gov (United States)

    Camp, Jordan

    2017-08-01

    Transient Astrophysics Probe (TAP), selected by NASA for a funded Concept Study, is a wide-field high-energy transient mission proposed for flight starting in the late 2020s. TAP’s main science goals, called out as Frontier Discovery areas in the 2010 Decadal Survey, are time-domain astrophysics and counterparts of gravitational wave (GW) detections. The mission instruments include unique imaging soft X-ray optics that allow ~500 deg2 FoV in each of four separate modules; a high sensitivity, 1 deg2 FoV soft X-ray telescope based on single crystal silicon optics; a passively cooled, 1 deg2 FoV Infrared telescope with bandpass 0.6-3 micron; and a set of ~8 small NaI gamma-ray detectors. TAP will observe many events per year of X-ray transients related to compact objects, including tidal disruptions of stars, supernova shock breakouts, neutron star bursts and superbursts, and high redshift Gamma-Ray Bursts. Perhaps most exciting is TAP’s capability to observe X-ray and IR counterparts of GWs involving stellar mass black holes detected by LIGO/Virgo, and possibly X-ray counterparts of GWs from supermassive black holes, detected by LISA and Pulsar Timing Arrays.

  13. Advanced PFBC transient analysis

    Energy Technology Data Exchange (ETDEWEB)

    White, J.S. [Parsons Power Group, Inc., Reading, PA (United States); Bonk, D.L.; Rogers, L. [USDOE Morgantown Energy Technology Center, WV (United States)

    1996-12-31

    Transient modeling and analysis of Advanced Pressurized Fluidized Bed Combustion (PFBC) systems is a research area that is currently under investigative study by the United States Department of Energy`s Morgantown Energy Technology Center (METC). The object of the effort is to identify key operating parameters affecting plant performance and then quantify the basic response of major sub-systems to changes in operating conditions. PC-TRAX, a commercially available dynamic software program, was chosen and applied in this modeling and analysis effort. This paper summarizes and describes the development of a series of TRAX-based transient models of Advanced PFBC power plants. These power plants generate a high temperature flue gas by burning coal or other suitable fuel in a PFBC. The high temperature flue gas supports low-Btu fuel gas or natural gas combustion in a gas turbine topping combustor. When utilized, low-Btu fuel gas is produced in a bubbling bed carbonizer. High temperature, high pressure combustion products exiting the topping combustor are expanded in a modified gas turbine to generate electrical power. Waste heat from the system is used to generate and superheat steam for a reheat steam turbine bottoming cycle that generates additional electrical power. Basic control/instrumentation models were developed and modeled in PC-TRAX and used to investigate off-design plant performance. System performance for various transient conditions and control philosophies was studied.

  14. Advanced PFBC transient analysis

    Energy Technology Data Exchange (ETDEWEB)

    White, J.S. [Parsons Power Group, Inc., Reading, PA (United States); Bonk, D.L. [USDOE Federal Energy Technology Center, Morgantown, WV (United States)

    1997-05-01

    Transient modeling and analysis of advanced Pressurized Fluidized Bed Combustion (PFBC) systems is a research area that is currently under investigation by the US Department of Energy`s Federal Energy Technology Center (FETC). The object of the effort is to identify key operating parameters that affect plant performance and then quantify the basic response of major sub-systems to changes in operating conditions. PC-TRAX{trademark}, a commercially available dynamic software program, was chosen and applied in this modeling and analysis effort. This paper describes the development of a series of TRAX-based transient models of advanced PFBC power plants. These power plants burn coal or other suitable fuel in a PFBC, and the high temperature flue gas supports low-Btu fuel gas or natural gas combustion in a gas turbine topping combustor. When it is utilized, the low-Btu fuel gas is produced in a bubbling bed carbonizer. High temperature, high pressure combustion products exiting the topping combustor are expanded in a modified gas turbine to generate electrical power. Waste heat from the system is used to raise and superheat steam for a reheat steam turbine bottoming cycle that generates additional electrical power. Basic control/instrumentation models were developed and modeled in PC-TRAX and used to investigate off-design plant performance. System performance for various transient conditions and control philosophies was studied.

  15. Lower complication rates for cranioplasty with peri-operative bundle.

    Science.gov (United States)

    Le, Catherine; Guppy, Kern H; Axelrod, Yekaterina V; Hawk, Mark W; Silverthorn, James; Inacio, Maria C; Akins, Paul T

    2014-05-01

    The overall benefits of craniectomy must include procedural risks from cranioplasty. Cranioplasty carries a high risk of surgical site infections (SSI) particularly with antibiotic resistant bacteria. The goal of this study was to measure the effect of a cranioplasty bundle on peri-operative complications. The authors queried a prospective, inpatient neurosurgery database at Kaiser Sacramento Medical Center for craniectomy and cranioplasty over a 7 year period. 57 patients who underwent cranioplasties were identified. A retrospective chart review was completed for complications, including surgical complications such as SSI, wound dehiscence, and re-do cranioplasty. We measured cranioplasty complication rates before and after implementation of a peri-operative bundle, which consisted of peri-operative vancomycin (4 doses), a barrier dressing through post-operative day (POD) 3, and de-colonization of the surgical incision using topical chlorhexidine from POD 4 to 7. The rate of MRSA colonization in cranioplasty patients is three times higher than the average seen on ICU admission screening (19% vs. 6%). The cranioplasty surgical complication rate was 22.8% and SSI rate was 10.5%. The concurrent SSI rate for craniectomy was 1.9%. Organisms isolated were methicillin-resistant Staphylococcus aureus (4), methicillin-sensitive S. aureus (1), Propionibacterium acnes (1), and Escherichia coli (1). Factors associated with SSI were peri-operative vancomycin (68.6% vs. 16.7%, p=0.0217). Complication rates without (n=21) and with (n=36) the bundle were: SSI (23.8% vs. 2.8%, p=0.0217) and redo cranioplasty (19% vs. 0%, p=0.0152). Bundle use did not affect rates for superficial wound dehiscence, seizures, or hydrocephalus. The cranioplasty bundle was associated with reduced SSI rates and the need for re-do cranioplasties. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Early Results of Anatomic Double Bundle Anterior Cruciate Ligament Reconstruction

    Directory of Open Access Journals (Sweden)

    Demet Pepele

    2014-03-01

    Full Text Available Aim: The goal in anterior cruciate ligament reconstruction (ACLR is to restore the normal anatomic structure and function of the knee. In the significant proportion of patients after the traditional single-bundle ACLR, complaints of instability still continue. Anatomic double bundle ACLR may provide normal kinematics in knees, much closer to the natural anatomy. The aim of this study is to clinically assess the early outcomes of our anatomical double bundle ACLR. Material and Method: In our clinic between June 2009 and March 2010, performed the anatomic double bundle ACLR with autogenous hamstring grafts 20 patients were evaluated prospectively with Cincinnati, IKDC and Lysholm scores and in clinically for muscle strength and with Cybex II dynamometer. Results: The mean follow-up is 17.8 months (13-21 months. Patients%u2019 scores of Cincinnati, IKDC and Lysholm were respectively, preoperative 18.1, 39.3 and 39.8, while the post-op increased to 27.2, 76.3 and 86.3. In their last check, 17 percent of the patients according to IKDC scores (85% A (excellent and B (good group and 3 patients took place as C (adequate group. The power measurements of quadriceps and hamstring muscle groups of patients who underwent surgery showed no significant difference compared with the intact knees. Discussion: Double-bundle ACL reconstruction is a satisfactory method. There is a need comparative, long-term studies in large numbers in order to determine improving clinical outcome, preventing degeneration and restoring the knee biomechanics better.

  17. The determinant bundle on the moduli space of stable triples over a ...

    Indian Academy of Sciences (India)

    We construct a holomorphic Hermitian line bundle over the moduli space of stable triples of the form (1, 2, ), where 1 and 2 are holomorphic vector bundles over a fixed compact Riemann surface , and : 2 → 1 is a holomorphic vector bundle homomorphism. The curvature of the Chern connection of this ...

  18. Lexical Bundles in Chinese Undergraduate Academic Writing at an English Medium University

    Science.gov (United States)

    Ruan, Zhoulin

    2017-01-01

    This paper investigates the use of lexical bundles in Chinese students' academic writing across different levels of studies at an English medium university. Frequency-based bundles were retrieved from a corpus of student academic texts written at four points of time between Year 1 and Year 4, and the structures and functions of the bundles were…

  19. Biomechanical comparisons of knee stability after anterior cruciate ligament reconstruction between 2 clinically available transtibial procedures: anatomic double bundle versus single bundle.

    Science.gov (United States)

    Kondo, Eiji; Merican, Azhar M; Yasuda, Kazunori; Amis, Andrew A

    2010-07-01

    Several trials have compared the clinical results between anatomic double-bundle and single-bundle anterior cruciate ligament reconstruction procedures. However, it remains controversial whether the anatomic double-bundle procedure is superior to the single-bundle procedure. The anatomic double-bundle procedure will be better than the single-bundle procedure at resisting anterior laxity, internal rotation laxity, and pivot-shift instability. Controlled laboratory study. Eight cadaveric knees were tested in a 6 degrees of freedom rig using the following loading conditions: 90-N anterior tibialforce, 5-N.m internal and external tibial torques, and a simulated pivot-shift test. Tibiofemoral kinematics during the flexion-extension cycle were recorded with an optical tracking system for (1) intact, (2) anterior cruciate ligament-deficient knee, (3) anatomic double-bundle reconstruction, and (4) single-bundle reconstruction placed at 11 o'clock in the intercondylar notch. There were significant reductions of anterior laxity of 3.5 mm at 20 degrees of flexion, internal rotational laxity of 2.5 degrees at 20 degrees of flexion, and anterior translations (2 mm) and internal rotations (5 degrees ) in the simulated pivot-shift test in the double-bundle reconstruction com-pared with the single-bundle reconstruction. There were no significant differences between the 2 procedures for external rotation laxity. The postoperative anterior translation and internal rotation stability after anatomic double-bundle anterior cruciate ligament reconstruction were significantly better than after single-bundle reconstruction, in both static tests and the pivot shift. Unlike previous laboratory studies, this work used clinical arthroscopic methods for anterior cruciate ligament reconstruction, and found that the anatomic reconstruction was superior to a single graft placed at 11 o'clock.

  20. Hierarchical mordenite zeolite nano-rods bundles favourable to bulky molecules

    Science.gov (United States)

    Dai, Guang; Hao, Wenming; Xiao, Huan; Ma, Jinghong; Li, Ruifeng

    2017-10-01

    Hierarchical mordenite zeolite nano-rods bundles were successfully synthesized by a novel approach of using organosilane functioned fumed silica as silicon source. The organic moiety linked on the surface of fumed silica inhibits the growth of zeolite crystal into large size, leading to the nano-rods assembled bundles. The mordenite nanorods bundles exhibited significantly improved mesitylene adsorption capacity compared with the conventional mordenite. As a catalyst, the hierarchical mordenite nanorods bundles showed remarkable catalytic performance in the benzylation of mesitylene by benzyl chloride, due to the efficient diffusion rate and improved accessibility of the active sites in the hierarchical mordenite nanorods bundles.

  1. A case of an infant with bundle branch reentrant ventricular tachycardia

    Directory of Open Access Journals (Sweden)

    Satoki Fujii

    2012-04-01

    Full Text Available Catheter ablation of the right bundle branch was performed on an 11-month-old infant for the treatment of drug-resistant bundle branch reentrant ventricular tachycardia. The occurrence of right bundle branch block could not be used as an endpoint of treatment because the patient had presented with incomplete right bundle branch block pattern during sinus rhythm. We performed ablation of the right bundle branch and utilized changes of duration and morphology of the QRS complex as indicators. Eight years have passed with no development of any atrioventricular block or tachycardia episode.

  2. Transport of single cells using an actin bundle-myosin bionanomotor transport system

    Energy Technology Data Exchange (ETDEWEB)

    Takatsuki, Hideyo; Rice, Kevin M; Kohama, Kazuhiro; Blough, Eric R [Department of Biological Sciences, Marshall University, Huntington, WV (United States); Tanaka, Hideyuki [Department of Molecular and Cellular Pharmacology, Gunma University Graduate School of Medicine, Maebashi (Japan); Kolli, Madhukar B; Nalabotu, Siva K [Center for Diagnostic Nanosystems, Marshall University, Huntington, WV (United States); Famouri, Parviz, E-mail: blough@marshall.edu [Lane Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV (United States)

    2011-06-17

    The potential of using actin bundles for the transport of liposomes and single cells across myosin-coated surfaces is investigated. Compared to that observed with filamentous actin, the liposome transport using actin bundles was more linear in nature and able to occur over longer distances. Bundles, but not filamentous actin, were capable of moving single cells. Cargo unloading from bundles was achieved by incubation with Triton X-100. These data suggest that actin bundling may improve the ability of the myosin motor system for nanotransport applications.

  3. Transient critical heat flux and blowdown heat-transfer studies

    Energy Technology Data Exchange (ETDEWEB)

    Leung, J.C.

    1980-05-01

    Objective of this study is to give a best-estimate prediction of transient critical heat flux (CHF) during reactor transients and hypothetical accidents. To accomplish this task, a predictional method has been developed. Basically it involves the thermal-hydraulic calculation of the heated core with boundary conditions supplied from experimental measurements. CHF predictions were based on the instantaneous ''local-conditions'' hypothesis, and eight correlations (consisting of round-tube, rod-bundle, and transient correlations) were tested against most recent blowdown heat-transfer test data obtained in major US facilities. The prediction results are summarized in a table in which both CISE and Biasi correlations are found to be capable of predicting the early CHF of approx. 1 s. The Griffith-Zuber correlation is credited for its prediction of the delay CHF that occurs in a more tranquil state with slowly decaying mass velocity. In many instances, the early CHF can be well correlated by the x = 1.0 criterion; this is certainly indicative of an annular-flow dryout-type crisis. The delay CHF occurred at near or above 80% void fraction, and the success of the modified Zuber pool-boiling correlation suggests that this CHF is caused by flooding and pool-boiling type hydrodynamic crisis.

  4. Familial Transient Global Amnesia

    Directory of Open Access Journals (Sweden)

    R.Rhys Davies

    2012-12-01

    Full Text Available Following an episode of typical transient global amnesia (TGA, a female patient reported similar clinical attacks in 2 maternal aunts. Prior reports of familial TGA are few, and no previous account of affected relatives more distant than siblings or parents was discovered in a literature survey. The aetiology of familial TGA is unknown. A pathophysiological mechanism akin to that in migraine attacks, comorbidity reported in a number of the examples of familial TGA, is one possibility. The study of familial TGA cases might facilitate the understanding of TGA aetiology.

  5. [Transient removable dentures].

    Science.gov (United States)

    Kouadio, A A; Jordana, F; N'Goran, J K; Le Bars, P

    2015-09-01

    Removable dentures are always transient current. The epidemiology and causes of tooth gaps demonstrate the need to master the different prosthetic treatment. This made whether to propose treatment plans that take into account psychological, physiological and technical support for this patient. Different situations may arise. A gradual transition may be considered or immediate passage to the total edentulous according to general criteria, local and desiderata of patients. After tooth extraction, the transitional prosthesis can control bone lysis thereby it is part of a complete treatment before prosthesis. It also facilitates a good psychological and physiological integration before the prosthesis use.

  6. Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction Using In Situ Hamstring Graft With 4 Tunnels

    Science.gov (United States)

    Wagih, Ahmad M.

    2013-01-01

    A careful review of the literature suggests that a significant number of patients undergoing anterior cruciate ligament (ACL) reconstruction have less-than-optimal results. Although overall outcomes of ACL reconstruction are favorable, there remains considerable room for improvement. Anatomically, the ACL consists of 2 major functional bundles, the anteromedial bundle and the posterolateral bundle. Biomechanically, both bundles contribute significantly to the anterior and rotational stability of the knee. Therefore anatomic double-bundle ACL reconstruction techniques may further improve the outcomes in ACL surgery. This article presents a technique for arthroscopic double-bundle ACL reconstruction that includes the use of 2 femoral and 2 tibial tunnels to restore both the anteromedial and posterolateral bundles of the ACL with minimal hardware for fixation. PMID:24749023

  7. Cosmic multi-muon bundles measured at DELPHI

    CERN Document Server

    Travnicek, Petr

    2002-01-01

    The DELPHI detector at LEP, located 100 $m$ underground, has been used to detect the multi-muon bundles by cathode readout of its hadron calorimeter and its tracking detectors (TPC, muon chambers). The experimental apparatus allows us to study muon bundles originating from primary cosmic particles with energies in the interval $10^{14}$ - $10^{17} eV$. The cosmic events registered during the years 1999 and 2000 correspond roughly to $1.6 10^6 s$ of effective run time. The aim of the work is to compare the measured muon multiplicity distributions and predictions of high energy interaction models for different types of primary particles and also to determine the absolute flux of events in certain muon multiplicity range. The presentation describes the current status of the analysis.

  8. Catastrophic Failure and Critical Scaling Laws of Fiber Bundle Material

    Directory of Open Access Journals (Sweden)

    Shengwang Hao

    2017-05-01

    Full Text Available This paper presents a spring-fiber bundle model used to describe the failure process induced by energy release in heterogeneous materials. The conditions that induce catastrophic failure are determined by geometric conditions and energy equilibrium. It is revealed that the relative rates of deformation of, and damage to the fiber bundle with respect to the boundary controlling displacement ε0 exhibit universal power law behavior near the catastrophic point, with a critical exponent of −1/2. The proportion of the rate of response with respect to acceleration exhibits a linear relationship with increasing displacement in the vicinity of the catastrophic point. This allows for the prediction of catastrophic failure immediately prior to failure by extrapolating the trajectory of this relationship as it asymptotes to zero. Monte Carlo simulations are completed and these two critical scaling laws are confirmed.

  9. An improved partial bundle method for linearly constrained minimax problems

    Directory of Open Access Journals (Sweden)

    Chunming Tang

    2016-02-01

    Full Text Available In this paper, we propose an improved partial bundle method for solving linearly constrained minimax problems. In order to reduce the number of component function evaluations, we utilize a partial cutting-planes model to substitute for the traditional one. At each iteration, only one quadratic programming subproblem needs to be solved to obtain a new trial point. An improved descent test criterion is introduced to simplify the algorithm. The method produces a sequence of feasible trial points, and ensures that the objective function is monotonically decreasing on the sequence of stability centers. Global convergence of the algorithm is established. Moreover, we utilize the subgradient aggregation strategy to control the size of the bundle and therefore overcome the difficulty of computation and storage. Finally, some preliminary numerical results show that the proposed method is effective.

  10. Analyses of bundle experiment data using MATRA-h

    Energy Technology Data Exchange (ETDEWEB)

    Lim, In Cheol; Chea, Hee Taek [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-06-01

    When the construction and operation license for HANARO was renewed in 1995, 25% of CHF penalty was imposed. The reason for this was that the validation work related to the CHF design calculation was not enough for the assurance of CHF margin. As a part of the works to recover this CHF penalty, MATRA-h was developed by implementing the new correlations for the heat transfer, CHF prediction, subcooled void to the MATRA-a, which is the modified version of COBRA-IV-I done by KAERI. Using MATRA-h, the subchannel analyses for the bundle experiment data were performed. The comparison of the code predictions with the experimental results, it was found that the code would give the conservative predictions as far as the CHF in the bundle geometry is concerned. (author). 12 refs., 25 figs., 16 tabs.

  11. Through silicon vias filled with planarized carbon nanotube bundles.

    Science.gov (United States)

    Wang, Teng; Jeppson, Kjell; Olofsson, Niklas; Campbell, Eleanor E B; Liu, Johan

    2009-12-02

    The feasibility of using carbon nanotube (CNT) bundles as the fillers of through silicon vias (TSVs) has been demonstrated. CNT bundles are synthesized directly inside TSVs by thermal chemical vapor deposition (TCVD). The growth of CNTs in vias is found to be highly dependent on the geometric dimensions and arrangement patterns of the vias at atmospheric pressure. The CNT-Si structure is planarized by a combined lapping and polishing process to achieve both a high removal rate and a fine surface finish. Electrical tests of the CNT TSVs have been performed and their electrical resistance was found to be in the few hundred ohms range. The reasons for the high electrical resistance have been discussed and possible methods to decrease the electrical resistance have been proposed.

  12. Buckling of a fiber bundle embedded in epoxy

    Science.gov (United States)

    Hahn, H. T.; Sohi, M. M.

    1986-01-01

    Buckling of a fiber bundle embedded in epoxy resin was studied to gain insight into compressive failure mechanisms in unidirectional composites. The fibers used were E-glass, T300 graphite, T700 graphite, and P75 graphite. These fibers were combined with two different resins: Epon 815/V140 and Epon 828/Z. In both resins the failure mode of the bundle was found to be microbuckling of fibers for the first three types of fibers; however, the high-modulus P75 fibers failed in shear without any sign of microbuckling. The strains at which microbuckling occurred were higher than the compressive failure strains of the corresponding unidirectional composites. In the soft resin, Epon 815/V140, fibers buckled at lower strains than in the stiff resin, Epon 828/Z. The buckling strains and the segment lengths followed the trends predicted for a single filament embedded in an infinite matrix.

  13. Bundle adjustment with raw inertial observations in UAV applications

    Science.gov (United States)

    Cucci, Davide Antonio; Rehak, Martin; Skaloud, Jan

    2017-08-01

    It is well known that accurate aerial position and attitude control is beneficial for image orientation in airborne photogrammetry. The aerial control is traditionally obtained by Kalman filtering/smoothing inertial and GNSS observations prior to the bundle-adjustment. However, in Micro Aerial Vehicles this process may result in poor attitude determination due to the limited quality of the inertial sensors, large alignment uncertainty and residual correlations between sensor biases and initial attitude. We propose to include the raw inertial observations directly into the bundle-adjustment instead of as position and attitude weighted observations from a separate inertial/GNSS fusion step. The necessary observation models are derived in detail within the context of the so called ;Dynamic Networks;. We examine different real world cases and we show that the proposed approach is superior to the established processing pipeline in challenging scenarios such as mapping in corridors and in areas where the reception of GNSS signals is denied.

  14. Balanced metrics for vector bundles and polarised manifolds

    DEFF Research Database (Denmark)

    Garcia Fernandez, Mario; Ross, Julius

    2012-01-01

    We consider a notion of balanced metrics for triples (X, L, E) which depend on a parameter α, where X is smooth complex manifold with an ample line bundle L and E is a holomorphic vector bundle over X. For generic choice of α, we prove that the limit of a convergent sequence of balanced metrics...... leads to a Hermitian-Einstein metric on E and a constant scalar curvature Kähler metric in c_1(L). For special values of α, limits of balanced metrics are solutions of a system of coupled equations relating a Hermitian-Einstein metric on E and a Kähler metric in c1(L). For this, we compute the top two...

  15. Transient dimers of allergens.

    Directory of Open Access Journals (Sweden)

    Juha Rouvinen

    Full Text Available BACKGROUND: Allergen-mediated cross-linking of IgE antibodies bound to the FcepsilonRI receptors on the mast cell surface is the key feature of the type I allergy. If an allergen is a homodimer, its allergenicity is enhanced because it would only need one type of antibody, instead of two, for cross-linking. METHODOLOGY/PRINCIPAL FINDINGS: An analysis of 55 crystal structures of allergens showed that 80% of them exist in symmetric dimers or oligomers in crystals. The majority are transient dimers that are formed at high protein concentrations that are reached in cells by colocalization. Native mass spectrometric analysis showed that native allergens do indeed form transient dimers in solution, while hypoallergenic variants of them exist almost solely in the monomeric form. We created a monomeric Bos d 5 allergen and show that it has a reduced capability to induce histamine release. CONCLUSIONS/SIGNIFICANCE: The results suggest that dimerization would be a very common and essential feature for allergens. Thus, the preparation of purely monomeric variants of allergens could open up novel possibilities for specific immunotherapy.

  16. Transient regional osteoporosis

    Directory of Open Access Journals (Sweden)

    F. Trotta

    2011-09-01

    Full Text Available Transient osteoporosis of the hip and regional migratory osteoporosis are uncommon and probably underdiagnosed bone diseases characterized by pain and functional limitation mainly affecting weight-bearing joints of the lower limbs. These conditions are usually self-limiting and symptoms tend to abate within a few months without sequelae. Routine laboratory investigations are unremarkable. Middle aged men and women during the last months of pregnancy or in the immediate post-partum period are principally affected. Osteopenia with preservation of articular space and transitory edema of the bone marrow provided by magnetic resonance imaging are common to these two conditions, so they are also known by the term regional transitory osteoporosis. The appearance of bone marrow edema is not specific to regional transitory osteoporosis but can be observed in several diseases, i.e. trauma, reflex sympathetic dystrophy, avascular osteonecrosis, infections, tumors from which it must be differentiated. The etiology of this condition is unknown. Pathogenesis is still debated in particular the relationship with reflex sympathetic dystrophy, with which regional transitory osteoporosis is often identified. The purpose of the present review is to remark on the relationship between transient osteoporosis of the hip and regional migratory osteoporosis with particular attention to the bone marrow edema pattern and relative differential diagnosis.

  17. A note on the tangent bundle of G/P

    Indian Academy of Sciences (India)

    Introduction. Let G be a simple linear algebraic group defined over C. Fix a proper parabolic subgroup. G/P. In [1], a Kähler–Einstein metric on G/P was constructed. This implies that the tangent bundle T (G/P ) is polystable (the definition is recalled below). We show that. T (G/P ) is stable. Since T (G/P ) is polystable, ...

  18. Optimal bundling of transmembrane helices using sparse distance constraints

    OpenAIRE

    Sale, Ken; Faulon, Jean-Loup; Genetha A. Gray; Schoeniger, Joseph S.; Young, Malin M.

    2004-01-01

    We present a two-step approach to modeling the transmembrane spanning helical bundles of integral membrane proteins using only sparse distance constraints, such as those derived from chemical cross-linking, dipolar EPR and FRET experiments. In Step 1, using an algorithm, we developed, the conformational space of membrane protein folds matching a set of distance constraints is explored to provide initial structures for local conformational searches. In Step 2, these structures refined against ...

  19. Higgs Bundles and Representations of Complex Hyperbolic Lattices

    OpenAIRE

    Maubon, Julien

    2015-01-01

    International audience; This paper is an introduction to the Higgs bundle theory of Hitchin and Simpson and a survey of its applications to the study of representations of complex hyperbolic lattices into Lie groups of Hermitian type. Some material concerning representations of surface groups will be covered but we shall be mainly interested in higher dimensional lattices, in particular in the proof of the rigidity of maximal representations of such lattices. (Concerning the rigidity of maxim...

  20. Image processing for cameras with fiber bundle image relay.

    Science.gov (United States)

    Olivas, Stephen J; Arianpour, Ashkan; Stamenov, Igor; Morrison, Rick; Stack, Ron A; Johnson, Adam R; Agurok, Ilya P; Ford, Joseph E

    2015-02-10

    Some high-performance imaging systems generate a curved focal surface and so are incompatible with focal plane arrays fabricated by conventional silicon processing. One example is a monocentric lens, which forms a wide field-of-view high-resolution spherical image with a radius equal to the focal length. Optical fiber bundles have been used to couple between this focal surface and planar image sensors. However, such fiber-coupled imaging systems suffer from artifacts due to image sampling and incoherent light transfer by the fiber bundle as well as resampling by the focal plane, resulting in a fixed obscuration pattern. Here, we describe digital image processing techniques to improve image quality in a compact 126° field-of-view, 30 megapixel panoramic imager, where a 12 mm focal length F/1.35 lens made of concentric glass surfaces forms a spherical image surface, which is fiber-coupled to six discrete CMOS focal planes. We characterize the locally space-variant system impulse response at various stages: monocentric lens image formation onto the 2.5 μm pitch fiber bundle, image transfer by the fiber bundle, and sensing by a 1.75 μm pitch backside illuminated color focal plane. We demonstrate methods to mitigate moiré artifacts and local obscuration, correct for sphere to plane mapping distortion and vignetting, and stitch together the image data from discrete sensors into a single panorama. We compare processed images from the prototype to those taken with a 10× larger commercial camera with comparable field-of-view and light collection.

  1. Bundle Data Approach at GES DISC Targeting Natural Hazards

    Science.gov (United States)

    Shie, Chung-Lin; Shen, Suhung; Kempler, Steven J.

    2015-01-01

    Severe natural phenomena such as hurricane, volcano, blizzard, flood and drought have the potential to cause immeasurable property damages, great socioeconomic impact, and tragic loss of human life. From searching to assessing the Big, i.e., massive and heterogeneous scientific data (particularly, satellite and model products) in order to investigate those natural hazards, it has, however, become a daunting task for Earth scientists and applications researchers, especially during recent decades. The NASA Goddard Earth Sciences Data and Information Service Center (GES DISC) has served Big Earth science data, and the pertinent valuable information and services to the aforementioned users of diverse communities for years. In order to help and guide our users to online readily (i.e., with a minimum effort) acquire their requested data from our enormous resource at GES DISC for studying their targeted hazard event, we have thus initiated a Bundle Data approach in 2014, first targeting the hurricane event topic. We have recently worked on new topics such as volcano and blizzard. The bundle data of a specific hazard event is basically a sophisticated integrated data package consisting of a series of proper datasets containing a group of relevant (knowledge--based) data variables readily accessible to users via a system-prearranged table linking those data variables to the proper datasets (URLs). This online approach has been developed by utilizing a few existing data services such as Mirador as search engine; Giovanni for visualization; and OPeNDAP for data access, etc. The online Data Cookbook site at GES DISC is the current host for the bundle data. We are now also planning on developing an Automated Virtual Collection Framework that shall eventually accommodate the bundle data, as well as further improve our management in Big Data.

  2. Weak point property and sections of Picard bundles on a ...

    Indian Academy of Sciences (India)

    Introduction. Debarre had proved that the Jacobian J0(X0) of a smooth curve X0 satisfies the diagonal property (Corollary 2.2 of [6]) i.e., there is a vector bundle of rank equal to the dimension of J0(X0) over J0(X0) × J0(X0), having a section whose zero scheme is the diagonal of J0(X0) × J0(X0). In this note, we generalize ...

  3. Determinants of contractile forces generated in disorganized actomyosin bundles.

    Science.gov (United States)

    Kim, Taeyoon

    2015-04-01

    Actomyosin machinery is a fundamental engine consisting mostly of actin filaments, molecular motors, and passive cross-linkers, generating mechanical forces required for biological processes of non-muscle cells such as cell migration, cytokinesis, and morphogenesis. Although the molecular and physical properties of key elements in the actomyosin machinery have been characterized well, it still remains unclear how macroscopic force buildup and dissipation in actomyosin networks and bundles depend on the microscopic properties of individual cytoskeletal components and their local interactions. To bridge such a gap between macroscopic and microscopic scales, we have developed a three-dimensional computational model of actomyosin bundles clamped to an elastic substrate with minimal components: actin filaments, passive cross-linkers, and active motors. Our model accounts for several key features neglected by previous studies despite their significance for force generation, such as realistic structure and kinetics of the motors. Using the model, we systematically investigated how net tension in actomyosin bundles is governed via interplay between motors and cross-linkers. We demonstrated motors can generate large tension on a bundle in the absence of cross-linkers in a very inefficient, unstable manner. Cross-linkers help motors to generate their maximum potential forces as well as enhance overall connectivity, leading to much higher efficiency and stability. We showed further that the cross-linkers behave as a molecular clutch with tunable friction which has quite distinct effects on net tension depending on their cross-linking angles. We also examined the source of symmetry breaking between tensile and compressive forces during tension generation process and discussed how the length and dynamics of actin filaments and the stiffness of the elastic substrate can affect the generated tension.

  4. HYDRODISSECTION FOR PRESERVATION OF NEUROVASCULAR BUNDLE DURING RADICAL PROSTATECTOMY

    Directory of Open Access Journals (Sweden)

    H. S. Gevorgyan

    2016-01-01

    Full Text Available Nerve-sparing radical prostatectomy is one of the high-tech operations in urology, and the challenge of the surgeon is not only to remove the prostate tumor, but also to provide a high quality of life. The fact that most questions devoted from patients in a conversation with the surgeon before the operation are devoted to this issue, shows the importance and relevance. At present, the diagnostic methods allow significantly more likely to detect early  prostate cancer, making finding and treatment of these patients more affordable and allows to apply this operation.Lately, it seems urgent to explore the possibility of water jet dissection in the field of urology, in particular, for nerve-sparing prostatectomy. Preservation of erectile function depends largely on the quality of separating the neurovascular bundle. Standard use of electrocautery is associated with damage to the neurovascular bundle.  When performing operations using water-jet mobilization of prostate the selective dissection of tissue is performed. This avoids injury of neurovascular bundle and further postoperative complications. The use of this technique may allow the surgeon to provide a more accurate mobilization prostate and selectively controlled intersection vessels heading to the prostate from the neurovascular bundle, reduce intraoperative blood loss,  maintaining continence, erectile function.This literature review is considered by the experience of using nerve-sparing radical prostatectomy using a water-jet dissector, estimated intraoperative parameters using this method.However, we have the lack of extensive research capabilities of this technique when performing nerve-preserving radical prostatectomy, that does not allow to make a comprehensive presentation on the benefits of this technique and its effects on erectile function and quality of urination, further study of this issue in such a difficult category of patients.

  5. Fluorescence Endoscopy in vivo based on Fiber-bundle Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Zufiria, B.; Gomez-Garcia, P.; Stamatakis, K.; Vaquero, J.J.; Fresno, M.; Desco, M.; Ripoll, J.; Arranz, A.

    2016-07-01

    High-resolution imaging techniques have become important for the determination of the cellular organization that is coupled to organ function. In many cases the organ can be viewed without the need of ionizing radiation techniques in an easier way. This is the case of the gastrointestinal tract, an organ that can be directly accessed with endoscopy avoiding any invasive procedure. Here we describe the design, assembly and testing of a fluorescence high-resolution endoscope intended for the study of the cellular organization of the colon in an experimental mouse model of colon carcinoma. Access to the colon of the mouse took place using a fiber-optic bundle that redirects the light coming from a LED to produce fluorescence and detect it back through the fiber bundle. Results from in vivo and ex-vivo test using our fluorescence fiber bundle endoscope show altered tissue structure and destruction of the intestinal crypts in tumor-bearing areas compared with healthy tissue. (Author)

  6. Differential geometry of moduli spaces of quiver bundles

    Science.gov (United States)

    Biswas, Indranil; Schumacher, Georg

    2017-08-01

    Let P be a parabolic subgroup of a semisimple affine algebraic group G defined over C and X a compact Kähler manifold. L. Álvarez-Cónsul and O. García-Prada associated to these a quiver Q and representations of Q into holomorphic vector bundles on X (Álvarez-Cónsul and García-Prada, 2003) [1, 2]. Our aim here is to investigate the differential geometric properties of the moduli spaces of representations of Q into vector bundles on X. In particular, we construct a Hermitian form on these moduli spaces. A fiber integral formula is proved for this Hermitian form; this fiber integral formula implies that the Hermitian form is Kähler. We compute the curvature of this Kähler form. Under an assumption which says that X is a complex projective manifold, this Kähler form is realized as the curvature of a certain determinant line bundle equipped with a Quillen metric.

  7. Enhanced boiling heat transfer in horizontal test bundles

    Energy Technology Data Exchange (ETDEWEB)

    Trewin, R.R.; Jensen, M.K.; Bergles, A.E.

    1994-08-01

    Two-phase flow boiling from bundles of horizontal tubes with smooth and enhanced surfaces has been investigated. Experiments were conducted in pure refrigerant R-113, pure R-11, and mixtures of R-11 and R-113 of approximately 25, 50, and 75% of R-113 by mass. Tests were conducted in two staggered tube bundles consisting of fifteen rows and five columns laid out in equilateral triangular arrays with pitch-to-diameter ratios of 1.17 and 1.5. The enhanced surfaces tested included a knurled surface (Wolverine`s Turbo-B) and a porous surface (Linde`s High Flux). Pool boiling tests were conducted for each surface so that reference values of the heat transfer coefficient could be obtained. Boiling heat transfer experiments in the tube bundles were conducted at pressures of 2 and 6 bar, heat flux values from 5 to 80 kW/m{sup 2}s, and qualities from 0% to 80%, Values of the heat transfer coefficients for the enhanced surfaces were significantly larger than for the smooth tubes and were comparable to the values obtained in pool boiling. It was found that the performance of the enhanced tubes could be predicted using the pool boiling results. The degradation in the smooth tube heat transfer coefficients obtained in fluid mixtures was found to depend on the difference between the molar concentration in the liquid and vapor.

  8. Fabrication of CANFLEX bundle kit for irradiation test in NRU

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Moon Sung; Kwon, Hyuk Il; Ji, Chul Goo; Chang, Ho Il; Sim, Ki Seob; Suk, Ho Chun

    1997-10-01

    CANFLEX bundle kit was prepared at KAERI for the fabrication of complete bundle at AECL. Completed bundle will be used for irradiation test in NRU. Provisions in the `Quality Assurance Manual for HWR Fuel Projects,` `Manufacturing Plan` and `Quality Verification, Inspection and Test Plan` were implemented as appropriately for the preparation of CANFLEX kit. A set of CANFLEX kit consist of 43 fuel sheath of two different sizes with spacers, bearing pads and buttons attached, 2 pieces of end plates and 86 pieces of end caps with two different sizes. All the documents utilized as references for the fabrication such as drawings, specifications, operating instructions, QC instructions and supplier`s certificates are specified in this report. Especially, suppliers` certificates and inspection reports for the purchased material as well as KAERI`s inspection report are integrated as attachments to this report. Attached to this report are supplier`s certificates and KAERI inspection reports for the procured materials and KAERI QC inspection reports for tubes, pads, spacers, buttons, end caps, end plates and fuel sheath. (author). 37 refs.

  9. An Unusual Cause of Transient Ischemic Attack in a Patient with Pacemaker

    Directory of Open Access Journals (Sweden)

    Jagadeesh Kumar Kalavakunta

    2014-01-01

    Full Text Available Pacemaker lead malposition in various locations has been described in the literature. Lead malposition in left ventricle is a rare and an underdiagnosed complication. We present a 77-year-old man with history of atrial fibrillation and pacemaker placement who was admitted for transient ischemic attack. He was on aspirin, beta blocker, and warfarin with subtherapeutic international normalized ratio. His paced electrocardiogram showed right bundle-branch block, rather than the typical pattern of left bundle-branch block, suggesting pacemaker lead malposition. Further, his chest X-ray and echocardiogram confirmed the pacemaker lead position in the left ventricle instead of right ventricle. He refused surgical removal of the lead and we increased his warfarin dose. Diagnosis of lead malposition in left ventricle, though easy to identify in echocardiogram, requires high index of clinical suspicion. In asymptomatic patients, surgical removal may be deferred for treatment with lifelong anticoagulation.

  10. Compactifications of the Heterotic string with unitary bundles

    Energy Technology Data Exchange (ETDEWEB)

    Weigand, T.

    2006-05-23

    In this thesis we investigate a large new class of four-dimensional supersymmetric string vacua defined as compactifications of the E{sub 8} x E{sub 8} and the SO(32) heterotic string on smooth Calabi-Yau threefolds with unitary gauge bundles and heterotic five-branes. The first part of the thesis discusses the implementation of this idea into the E{sub 8} x E{sub 8} heterotic string. After specifying a large class of group theoretic embeddings featuring unitary bundles, we analyse the effective four-dimensional N=1 supergravity upon compactification. From the gauge invariant Kaehler potential for the moduli fields we derive a modification of the Fayet-Iliopoulos D-terms arising at one-loop in string perturbation theory. From this we conjecture a one-loop deformation of the Hermitian Yang-Mills equation and introduce the idea of {lambda}-stability as the perturbatively correct stability concept generalising the notion of Mumford stability valid at tree-level. We then proceed to a definition of SO(32) heterotic vacua with unitary gauge bundles in the presence of heterotic five-branes and find agreement of the resulting spectrum with the S-dual framework of Type I/Type IIB orientifolds. A similar analysis of the effective four-dimensional supergravity is performed. Further evidence for the proposed one-loop correction to the stability condition is found by identifying the heterotic corrections as the S-dual of the perturbative part of {pi}-stability as the correct stability concept in Type IIB theory. After reviewing the construction of holomorphic stable vector bundles on elliptically fibered Calabi-Yau manifolds via spectral covers, we provide semi-realistic examples for SO(32) heterotic vacua with Pati-Salam and MSSM-like gauge sectors. We finally discuss the construction of realistic vacua with flipped SU(5) GUT and MSSM gauge group within the E{sub 8} x E{sub 8} framework, based on the embedding of line bundles into both E{sub 8} factors. Some of the appealing

  11. Getting the Most from Your CD-ROM Dollars: The CD-ROM Bundle [and] The Pros and Cons of CD-ROM Bundling.

    Science.gov (United States)

    Sarjeant, Eric W.; O'Connor, Mary Ann

    1992-01-01

    Discusses and reviews CD-ROM bundles--i.e., hardware, software and CD-ROM kits--including their features, specifications, drawbacks, and prices. Recommends buying through mail order for the best selection and price. The pros and cons of bundling as a marketing strategy are discussed and a list of vendors is provided. (EA)

  12. One stage revision single-bundle anterior cruciate ligament reconstruction with impacted morselized bone graft following a failed double-bundle reconstruction

    Directory of Open Access Journals (Sweden)

    Ho Jong Ra

    2017-01-01

    Full Text Available Although double-bundle anterior cruciate ligament (ACL reconstruction has theoretical benefits such as more accurate reproduction of ACL anatomy, it is technically more demanding surgery. This report describes the case of a one stage revision single-bundle ACL reconstruction after primary double-bundle ACL reconstruction. A professional dancer had an ACL previously reconstructed with a double-bundle technique, but the femoral tunnels were malpositioned resulting in residual laxity and rotational instability. The previous femoral tunnel positions were vertical and widened. The previous vertical tunnels were filled with impacted bone graft and a revision single-bundle ACL reconstruction was performed via the new femoral tunnel with a 2 O'clock position between the previous two tunnels. After 10 months of postoperative rehabilitation, the patient returned to professional dancing with sound bony union and without any residual instability.

  13. Double-bundle depiction of the anterior cruciate ligament at 3 Tesla

    Energy Technology Data Exchange (ETDEWEB)

    Adriaensen, M.E.A.P.M. [Atrium Medical Center Parkstad, Department of Radiology, Heerlen (Netherlands); Hogan, B. [Sports Surgery Clinic, Department of Radiology, Dublin (Ireland); Al-Bulushi, H.I.J. [Armed Forces Hospital, Department of Radiology, Muscat (Oman); Kavanagh, E.C. [Mater Misericordiae Hospital, Department of Radiology, Dublin (Ireland)

    2012-07-15

    Magnetic resonance imaging on 3 Tesla (3T MRI) with arthroscopic correlation has proven to adequately identify the anteromedial bundle (AMB) and posterolateral bundle (PLB) in cadaver knees. The purpose of this study was to describe the depiction of ACL bundle anatomy on 3T MRI in daily practice. In a retrospective cohort study, we included 50 consecutive patients who underwent standard 3T MRI of the knee and had an intact ACL. Two musculoskeletal radiologists independently reviewed all scans for depiction of ACL bundle anatomy using standardized forms. Descriptive statistics were used. Twenty-three right knees (46%) and 27 left knees (54%) were included in the study. Mean age of the patients was 35 years (range 12 to 68 years); 37 patients were male (74%). ACL bundle anatomy was best depicted in the axial plane in 44 knees (88%) and in the coronal plane in six knees (12%). Two bundles were seen in 47 knees (94%). The AMB was completely seen in 45 knees (90%). The PLB was completely seen in 40 knees (80%). Both bundles were completely seen in 37 knees (76%). The double-bundle anatomy of the ACL is visualized in 94% of patients on 3T MRI. Because of potentially associated clinical benefits, we advocate to report separately on the anteromedial bundle and posterolateral bundle in case of anterior cruciate ligament injury of the knee. (orig.)

  14. New models of droplet deposition and entrainment for prediction of CHF in cylindrical rod bundles

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Haibin, E-mail: hb-zhang@xjtu.edu.cn [School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Department of Chemical Engineering, Imperial College, London SW7 2BY (United Kingdom); Hewitt, G.F. [Department of Chemical Engineering, Imperial College, London SW7 2BY (United Kingdom)

    2016-08-15

    Highlights: • New models of droplet deposition and entrainment in rod bundles is developed. • A new phenomenological model to predict the CHF in rod bundles is described. • The present model is well able to predict CHF in rod bundles. - Abstract: In this paper, we present a new set of model of droplet deposition and entrainment in cylindrical rod bundles based on the previously proposed model for annuli (effectively a “one-rod” bundle) (2016a). These models make it possible to evaluate the differences of the rates of droplet deposition and entrainment for the respective rods and for the outer tube by taking into account the geometrical characteristics of the rod bundles. Using these models, a phenomenological model to predict the CHF (critical heat flux) for upward annular flow in vertical rod bundles is described. The performance of the model is tested against the experimental data of Becker et al. (1964) for CHF in 3-rod and 7-rod bundles. These data include tests in which only the rods were heated and data for simultaneous uniform and non-uniform heating of the rods and the outer tube. It was shown that the predicted CHFs by the present model agree well with the experimental data and with the experimental observation that dryout occurred first on the outer rods in 7-rod bundles. It is expected that the methodology used will be generally applicable in the prediction of CHF in rod bundles.

  15. Transient Go: A Mobile App for Transient Astronomy Outreach

    Science.gov (United States)

    Crichton, D.; Mahabal, A.; Djorgovski, S. G.; Drake, A.; Early, J.; Ivezic, Z.; Jacoby, S.; Kanbur, S.

    2016-12-01

    Augmented Reality (AR) is set to revolutionize human interaction with the real world as demonstrated by the phenomenal success of `Pokemon Go'. That very technology can be used to rekindle the interest in science at the school level. We are in the process of developing a prototype app based on sky maps that will use AR to introduce different classes of astronomical transients to students as they are discovered i.e. in real-time. This will involve transient streams from surveys such as the Catalina Real-time Transient Survey (CRTS) today and the Large Synoptic Survey Telescope (LSST) in the near future. The transient streams will be combined with archival and latest image cut-outs and other auxiliary data as well as historical and statistical perspectives on each of the transient types being served. Such an app could easily be adapted to work with various NASA missions and NSF projects to enrich the student experience.

  16. Anticancer drug vinblastine sulphate induces transient morphological changes on the olfactory mucosa of the rabbit.

    Science.gov (United States)

    Kavoi, B M; Makanya, A N; Kiama, S G

    2012-10-01

    Vinblastine sulphate (VBS) is an anticancer drug that acts by disrupting microtubule dynamics of highly mitotic tissue cells. The consequences of VBS on the olfactory mucosa (OM), a tissue with high mitotic numbers, are not clearly understood. We used qualitative and quantitative methods to determine the structural changes that may be produced on the rabbit OM by VBS. Following a single dose (0.31 mg/kg) of this drug, the structure of the mucosa was greatly altered on the first 3-5 days. The alteration was characterized by disarrangement of the normal layering of nuclei of the epithelia, degeneration of axonal bundles, occurrence of blood vessels within the bundles, localized death of cells of Bowman's glands and glandular degeneration. Surprisingly on or after day 7 and progressively to day 15 post-exposure, the OM was observed to regenerate and acquire normal morphology, and the vessels disappeared from the bundles. Relative to control values, bundle diameters, olfactory cell densities and cilia numbers decreased to as low as 53.1, 75.2 and 71.4%, respectively, on day 5. Volume density for the bundles, which was 28.6% in controls, decreased to a lowest value of 16.8% on day 5. In contrast, the volume density for the blood vessels was significantly lower in controls (19.9%) than in treated animals at day 2 (25.8%), day 3 (34.3%) and day 5 (31.5%). These findings suggest that the changes induced on the rabbit OM by VBS are transient and that regenerative recovery leads to the restoration of the normal structure of the mucosa. © 2012 Blackwell Verlag GmbH.

  17. Frequency-Domain Transient Imaging.

    Science.gov (United States)

    Jingyu Lin; Yebin Liu; Jinli Suo; Qionghai Dai

    2017-05-01

    A transient image is the optical impulse response of a scene, which also visualizes the propagation of light during an ultra-short time interval. In contrast to the previous transient imaging which samples in the time domain using an ultra-fast imaging system, this paper proposes transient imaging in the frequency domain using a multi-frequency time-of-flight (ToF) camera. Our analysis reveals the Fourier relationship between transient images and the measurements of a multi-frequency ToF camera, and identifies the causes of the systematic error-non-sinusoidal and frequency-varying waveforms and limited frequency range of the modulation signal. Based on the analysis we propose a novel framework of frequency-domain transient imaging. By removing the systematic error and exploiting the harmonic components inside the measurements, we achieves high quality reconstruction results. Moreover, our technique significantly reduces the computational cost of ToF camera based transient image reconstruction, especially reduces the memory usage, such that it is feasible for the reconstruction of transient images at extremely small time steps. The effectiveness of frequency-domain transient imaging is tested on synthetic data, real data from the web, and real data acquired by our prototype camera.

  18. Pressure transients in pipeline systems

    DEFF Research Database (Denmark)

    Voigt, Kristian

    1998-01-01

    This text is to give an overview of the necessary background to do investigation of pressure transients via simulations. It will describe briefly the Method of Characteristics which is the defacto standard for simulating pressure transients. Much of the text has been adopted from the book Pressure...

  19. CURRENT STATUS OF INTEGRITY ASSESSMENT BY SIPPING SYSTEM OF SPENT FUEL BUNDLES IRRADIATED IN CANDU REACTOR

    Directory of Open Access Journals (Sweden)

    JONG-YOUL PARK

    2014-12-01

    Full Text Available In terms of safety and the efficient management of spent fuel storage, detecting failed fuel is one of the most important tasks in a CANada Deuterium Uranium (CANDU reactor operation. It has been successfully demonstrated that in a CANDU reactor, on-power failed fuel detection and location systems, along with alarm area gamma monitors, can detect and locate defective and suspect fuel bundles before discharging them from the reactor to the spent fuel storage bay. In the reception bay, however, only visual inspection has been used to identify suspect bundles. Gaseous fission product and delayed neutron monitoring systems cannot precisely distinguish failed fuel elements from each fuel bundle. This study reports the use of a sipping system in a CANDU reactor for the integrity assessment of spent fuel bundles. The integrity assessment of spent fuel bundles using this sipping system has shown promise as a nondestructive test for detecting a defective fuel bundle in a CANDU reactor.

  20. Structural Causes of Right Bundle Branch Block—Time for a Closer Look?

    Science.gov (United States)

    Ker, James

    2010-01-01

    Right bundle branch block is an electrocardiographic phenomenon with specific criteria. Currently, two specific forms of right bundle branch block are acknowledged, a proximal and a distal variant. A vast array of pathologies can cause proximal, distal or even combined forms of right bundle branch block. In this study it is suggested that a third type of right bundle branch block exist: one caused by a subaortic muscular tendon in the left ventricle, leading to an increased velocity of conduction in the left ventricle, with a resultant “relative” right bundle branch block. It is concluded that it is necessary (and time) to take a closer look at endoventricular structures in the assessment of structural causes of right bundle branch block. PMID:20386615

  1. Hydrodynamic behavior of a bare rod bundle. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Bartzis, J.G.; Todreas, N.E.

    1977-06-01

    The temperature distribution within the rod bundle of a nuclear reactor is of major importance in nuclear reactor design. However temperature information presupposes knowledge of the hydrodynamic behavior of the coolant which is the most difficult part of the problem due to complexity of the turbulence phenomena. In the present work a 2-equation turbulence model--a strong candidate for analyzing actual three dimensional turbulent flows--has been used to predict fully developed flow of infinite bare rod bundle of various aspect ratios (P/D). The model has been modified to take into account anisotropic effects of eddy viscosity. Secondary flow calculations have been also performed although the model seems to be too rough to predict the secondary flow correctly. Heat transfer calculations have been performed to confirm the importance of anisotropic viscosity in temperature predictions. All numerical calculations for flow and heat have been performed by two computer codes based on the TEACH code. Experimental measurements of the distribution of axial velocity, turbulent axial velocity, turbulent kinetic energy and radial Reynolds stresses were performed in the developing and fully developed regions. A 2-channel Laser Doppler Anemometer working on the Reference mode with forward scattering was used to perform the measurements in a simulated interior subchannel of a triangular rod array with P/D = 1.124. Comparisons between the analytical results and the results of this experiment as well as other experimental data in rod bundle array available in literature are presented. The predictions are in good agreement with the results for the high Reynolds numbers.

  2. Applied hydraulic transients

    CERN Document Server

    Chaudhry, M Hanif

    2014-01-01

    This book covers hydraulic transients in a comprehensive and systematic manner from introduction to advanced level and presents various methods of analysis for computer solution. The field of application of the book is very broad and diverse and covers areas such as hydroelectric projects, pumped storage schemes, water-supply systems, cooling-water systems, oil pipelines and industrial piping systems. Strong emphasis is given to practical applications, including several case studies, problems of applied nature, and design criteria. This will help design engineers and introduce students to real-life projects. This book also: ·         Presents modern methods of analysis suitable for computer analysis, such as the method of characteristics, explicit and implicit finite-difference methods and matrix methods ·         Includes case studies of actual projects ·         Provides extensive and complete treatment of governed hydraulic turbines ·         Presents design charts, desi...

  3. Restitution characteristics of His bundle and working myocardium in isolated rabbit hearts.

    Science.gov (United States)

    Huang, Shangwei; Wu, Liqun; Huang, Jian; Panitchob, Nuttanont; Hu, Nan; Ranjan, Ravi; Dosdall, Derek J

    2017-01-01

    The Purkinje system (PS) and the His bundle have been recently implicated as an important driver of the rapid activation rate after 1-2 minutes of ventricular fibrillation (VF). It is unknown whether activations during VF propagate through the His-Purkinje system to other portions of the the working myocardium (WM). Little is known about restitution characteristic differences between the His bundle and working myocardium at short cycle lengths. In this study, rabbit hearts (n = 9) were isolated, Langendorff-perfused, and electromechanically uncoupled with blebbistatin (10 μM). Pacing pulses were delivered directly to the His bundle. By using standard glass microelectrodes, action potentials duration (APD) from the His bundle and WM were obtained simultaneously over a wide range of stimulation cycle lengths (CL). The global F-test indicated that the two restitution curves of the His bundle and the WM are statistically significantly different (PHis bundle was significantly shorter than that of WM throughout the whole pacing course (PHis bundle vs. the WM were shorter for the His bundle (134.2±13.1ms vs. 148.3±13.3ms, PHis bundle than in WM (130.0±10.0 vs. 145.6±14.2ms, PHis bundle APD was significantly shorter than that of WM under both slow and rapid pacing rates, which suggest that there may be an excitable gap during VF and that the His bundle may conduct wavefronts from one bundle branch to the other at short cycle lengths and during VF.

  4. Non-properness of the functor of F-trivial bundles

    Indian Academy of Sciences (India)

    This is defined by assigning a Tannaka group to the Tannaka category of essentially finite vector bundles on. X [13, 14]. In these papers, Nori had made 2 conjectures: ... For any integer n > 1, we could define on Fn-trivial bundles on X as a .... for some line bundles Li, 1 ≤ i ≤ s on R with deg L1 > deg L2 > ··· > deg Ls.

  5. Recurrent extensive anterior myocardial infarction with left and right bundle branch block.

    Science.gov (United States)

    Jiang, Hexi; Chang, Qinghua; Zhang, Yingjie; Liu, Renguang

    2017-10-15

    The diagnosis of myocardial infarction with left bundle branch block is difficult. We report a case of 56-year-old man with old extensive anterior myocardial infarction and left bundle branch block (masked each other). The recurrent myocardial infarction indicated right bundle branch block and first-degree atrioventricular block, making a clear diagnosis of complicated and interesting ECG. © 2017 Wiley Periodicals, Inc.

  6. Harder Roads to Trek? Paradoxical Slowing of an Atrioventricular Reentrant Tachycardia With Contralateral Bundle Branch Block.

    Science.gov (United States)

    Divakara Menon, Syamkumar M; Ayati, Maryam; Healey, Jeff S

    2017-04-01

    Slowing of the tachycardia with increase in cycle length and increase in VA time with ipsilateral bundle branch block is a characteristic feature of accessory pathway mediated AVRT. Contralateral bundle branch block has no effect on the tachycardia as it is not a part of the tachycardia circuit. We present an interesting phenomenon in which contralateral bundle branch block resulted in tachycardia slowing in a case of WPW syndrome. © 2016 Wiley Periodicals, Inc.

  7. Left bundle-branch block with right axis deviation--a unique aberrancy during supraventricular tachycardia.

    Science.gov (United States)

    Lokhandwala, Yash; Panicker, Gopi Krishna; Shah, Mandar; Wellens, Hein J J

    2009-01-01

    A tachycardia with left bundle-branch block morphology and right axis deviation points to the diagnosis of ventricular tachycardia. Conversely, any supraventricular tachycardia with left bundle-branch block is typically associated with a normal or leftward QRS axis. We present the case of a 34-year-old man showing atrioventricular nodal reentrant tachycardia with left bundle-branch block/right axis deviation as an exception to this rule.

  8. Intersection cohomology of moduli spaces of vector bundles over curves

    OpenAIRE

    Mozgovoy, Sergey; Reineke, Markus

    2015-01-01

    We compute the intersection cohomology of the moduli spaces $M(r,d)$ of semistable vector bundles of arbitrary rank $r$ and degree $d$ over a curve. To do this, we introduce new invariants, called Donaldson-Thomas invariants of a curve, which can be effectively computed by methods going back to Harder, Narasimhan, Desale and Ramanan. Our main result relates the Hodge-Euler polynomial of the intersection cohomology of $M(r,d)$ to the Donaldson-Thomas invariants. More generally, we introduce Do...

  9. Isolated Left Bundle Branch Block in a Toddler

    Directory of Open Access Journals (Sweden)

    Hitesh Agrawal

    2014-01-01

    Full Text Available Left bundle branch block (LBBB usually occurs as a postoperative complication from surgical correction of congenital heart disease and can be associated with hypertensive heart disease, coronary artery disease, myocarditis, and aortic valvular disease. Although isolated LBBB is a conduction abnormality found in some healthy adults, it has not been reported in pediatric population. We report a 2-year-old, healthy African American female who was incidentally discovered to have isolated LBBB that has persisted in a follow-up of 3 years.

  10. Isolated Left Bundle Branch Block in a Toddler

    Science.gov (United States)

    Zimmerman, Frank; Naheed, Zahra

    2014-01-01

    Left bundle branch block (LBBB) usually occurs as a postoperative complication from surgical correction of congenital heart disease and can be associated with hypertensive heart disease, coronary artery disease, myocarditis, and aortic valvular disease. Although isolated LBBB is a conduction abnormality found in some healthy adults, it has not been reported in pediatric population. We report a 2-year-old, healthy African American female who was incidentally discovered to have isolated LBBB that has persisted in a follow-up of 3 years. PMID:24963416

  11. Visualization of the medial forebrain bundle using diffusion tensor imaging

    Directory of Open Access Journals (Sweden)

    Ardian eHana

    2015-10-01

    Full Text Available Diffusion tensor imaging is a technique that enables physicians the portrayal of white matter tracts in vivo. We used this technique in order to depict the medial forebrain bundle in 15 consecutive patients between 2012 and 2015. Men and women of all ages were included. There were 6 women and 9 men. The mean age was 58,6 years (39-77. Nine patients were candidates for an eventual deep brain stimulation. Eight of them suffered from Parkinson`s disease and one had multiple sclerosis. The remaining 6 patients suffered from different lesions which were situated in the frontal lobe. These were 2 metastasis, 2 meningiomas, 1 cerebral bleeding and 1 glioblastoma. We used a 3DT1-sequence for the navigation. Furthermore T2- and DTI- sequences were performed. The FOV was 200 x 200 mm², slice thickness 2 mm, and an acquisition matrix of 96 x 96 yielding nearly isotropic voxels of 2 x 2 x 2 mm. 3-Tesla-MRI was carried out strictly axial using 32 gradient directions and one b0-image. We used Echo-Planar-Imaging (EPI and ASSET parallel imaging with an acceleration factor of 2. b-value was 800 s/mm². The maximal angle was 50°. Additional scanning time was less than 9 minutes. We were able to visualize the medial forebrain bundle in 12 of our patients bilaterally and in the remaining 3 patients we depicted the medial forebrain bundle on one side. It was the contralateral side of the lesion. These were 2 meningiomas and one metastasis. Portrayal of the medial forebrain bundle is possible for everyday routine for neurosurgical interventions. As part of the reward circuitry it might be of substantial importance for neurosurgeons during deep brain stimulation in patients with psychiatric disorders. Furthermore it might explain at a certain extent character changes in patients with lesions in the frontal lobe. Surgery in this part of the brain should always take the preservation of this white matter tract into account.

  12. A Parallel Section Functor for 2-Vector Bundles

    OpenAIRE

    Schweigert, Christoph; Woike, Lukas

    2017-01-01

    We associate to a 2-vector bundle over an essentially finite groupoid a 2-vector space of parallel sections, or, in representation theoretic terms, of higher invariants, which can be described as homotopy fixed points. Our main result is the extension of this assignment to a symmetric monoidal 2-functor $\\operatorname{Par} : \\mathbf{2VecBunGrpd} \\to \\mathbf{2Vect}$. It is defined on the symmetric monoidal bicategory $\\mathbf{2VecBunGrpd}$ whose morphisms arise from spans of groupoids in such ...

  13. Bundle branch reentry: A rare mechanism of ventricular tachycardia in endomyocardial fibrosis, without ventricular dilation.

    Science.gov (United States)

    Prabhu, Mukund A; Prasad, B V Srinivas; Thajudeen, Anees; Namboodiri, Narayanan

    2016-09-01

    Bundle branch reentry as a mechanism of ventricular tachycardia (VT) in endomyocardial fibrosis (EMF) is not described. A 52-year-old woman with left ventricular (LV) EMF had VT needing cardioversion. She had mitral regurgitation and left bundle branch block, but no LV dilation or heart failure. During electrophysiological study, clinical VT could be easily induced, and it was confirmed to be bundle branch reentrant VT (BBRVT). She was treated with ablation of the right bundle branch. BBRVT can occur in EMF even without cardiac dilatation. Its recognition is important, as radiofrequency ablation can be curative. Copyright © 2016 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  14. Effects of reward bundling on male rats' preference for larger-later food rewards.

    Science.gov (United States)

    Stein, Jeffrey S; Smits, Rochelle R; Johnson, Patrick S; Liston, Kennan J; Madden, Gregory J

    2013-03-01

    In both humans and nonhumans, prior research demonstrates increased preference for larger-later over smaller-sooner rewards when rewards are bundled together in a series (i.e., when an operant choice produces multiple discrete reward deliveries, as opposed to only a single delivery). These findings can be predicted using a traditional hyperbolic delay-discounting model. The present study was designed to examine the parametric effects of the size of the reward bundle on larger-later reward preference in male rats. During a reward-bundling phase, rats were exposed to bundle-sizes of either 1 (i.e., no bundling), 3, or 9 rewards. Rats in the Bundle-size 9 group showed significantly greater larger-later reward preference across a range of delays (0-17.5 s) than rats in any other group, but no other significant differences in choice were observed between groups. In addition, when choice for unbundled rewards was assessed following the reward-bundling phase, rats in the Bundle-size 9 group showed a significant increase in larger-later reward preference (compared to a pre-test). Obtained data from the reward-bundling phase are compared to model-predicted data, and potential mechanisms of the observed increase in self-control for unbundled rewards are discussed. © Society for the Experimental Analysis of Behavior.

  15. Verification of a neutronic code for transient analysis in reactors with Hex-z geometry

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Pintor, S.; Verdu, G. [Departamento de Ingenieria Quimica Y Nuclear, Universitat Politecnica de Valencia, Cami de Vera, 14, 46022. Valencia (Spain); Ginestar, D. [Departamento de Matematica Aplicada, Universitat Politecnica de Valencia, Cami de Vera, 14, 46022. Valencia (Spain)

    2012-07-01

    Due to the geometry of the fuel bundles, to simulate reactors such as VVER reactors it is necessary to develop methods that can deal with hexagonal prisms as basic elements of the spatial discretization. The main features of a code based on a high order finite element method for the spatial discretization of the neutron diffusion equation and an implicit difference method for the time discretization of this equation are presented and the performance of the code is tested solving the first exercise of the AER transient benchmark. The obtained results are compared with the reference results of the benchmark and with the results provided by PARCS code. (authors)

  16. Electromagnetic transients in power cables

    CERN Document Server

    da Silva, Filipe Faria

    2013-01-01

    From the more basic concepts to the most advanced ones where long and laborious simulation models are required, Electromagnetic Transients in Power Cables provides a thorough insight into the study of electromagnetic transients and underground power cables. Explanations and demonstrations of different electromagnetic transient phenomena are provided, from simple lumped-parameter circuits to complex cable-based high voltage networks, as well as instructions on how to model the cables.Supported throughout by illustrations, circuit diagrams and simulation results, each chapter contains exercises,

  17. Machine Classification of Transient Images

    Science.gov (United States)

    Buisson, Lise Du; Sivanandam, Navin; Bassett, Bruce A.; Smith, Mathew

    2014-05-01

    Using transient imaging data from the 2nd and 3rd years of the SDSS supernova survey, we apply various machine learning techniques to the problem of classifying transients (e.g. SNe) from artefacts, one of the first steps in any transient detection pipeline, and one that is often still carried out by human scanners. Using features mostly obtained from PCA, we show that we can match human levels of classification success, and find that a K-nearest neighbours algorithm and SkyNet perform best, while the Naive Bayes, SVM and minimum error classifier have performances varying from slightly to significantly worse.

  18. Prostaglandins temporally regulate cytoplasmic actin bundle formation during Drosophila oogenesis

    Science.gov (United States)

    Spracklen, Andrew J.; Kelpsch, Daniel J.; Chen, Xiang; Spracklen, Cassandra N.; Tootle, Tina L.

    2014-01-01

    Prostaglandins (PGs)—lipid signals produced downstream of cyclooxygenase (COX) enzymes—regulate actin dynamics in cell culture and platelets, but their roles during development are largely unknown. Here we define a new role for Pxt, the Drosophila COX-like enzyme, in regulating the actin cytoskeleton—temporal restriction of actin remodeling during oogenesis. PGs are required for actin filament bundle formation during stage 10B (S10B). In addition, loss of Pxt results in extensive early actin remodeling, including actin filaments and aggregates, within the posterior nurse cells of S9 follicles; wild-type follicles exhibit similar structures at a low frequency. Hu li tai shao (Hts-RC) and Villin (Quail), an actin bundler, localize to all early actin structures, whereas Enabled (Ena), an actin elongation factor, preferentially localizes to those in pxt mutants. Reduced Ena levels strongly suppress early actin remodeling in pxt mutants. Furthermore, loss of Pxt results in reduced Ena localization to the sites of bundle formation during S10B. Together these data lead to a model in which PGs temporally regulate actin remodeling during Drosophila oogenesis by controlling Ena localization/activity, such that in S9, PG signaling inhibits, whereas at S10B, it promotes Ena-dependent actin remodeling. PMID:24284900

  19. A preliminary stability analysis of MYRRHA Primary Heat Exchanger two-phase tube bundle

    Energy Technology Data Exchange (ETDEWEB)

    Castelliti, Diego [Studiecentrum voor kernenergie – Centre d’étude de l’énergie nucléaire (SCK-CEN), Boeretang 200, Mol (Belgium); GeNERG – DIME/TEC, University of Genova, Via all’Opera Pia 15/a, 16145 Genova (Italy); Lomonaco, Guglielmo, E-mail: guglielmo.lomonaco@unige.it [GeNERG – DIME/TEC, University of Genova, Via all’Opera Pia 15/a, 16145 Genova (Italy); INFN, Via Dodecaneso 33, 16146 Genova (Italy)

    2016-08-15

    Highlights: • MYRRHA is a pool-type LBE-cooled ADS, operable also as a critical reactor. • MYRRHA is a high priority infrastructure for nuclear research in Europe. • PHX (primary side: LBE, secondary side: two-phase water), is a MYRRHA key component. • The original MYRRHA PHX design does not offer a fully satisfying response to DWO. • The adoption of an orifice allows extending considerably the stability of MYRRHA PHX. - Abstract: The MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) project, started at SCK·CEN since 1999, aims at the construction of a pool-type sub-critical Accelerator-Driven System (ADS) which could also operate as a critical reactor. The primary system, enclosed in the primary vessel, is filled with Lead Bismuth Eutectic (LBE) which acts as primary coolant. The power is then delivered through four heat exchangers to four secondary loops. The secondary cooling fluid is two-phase water operating at relatively low pressure (16 bar). Four aero-condensers act as heat sinks, since MYRRHA design does not foresee any electricity generation. The MYRRHA Primary Heat eXchangers (PHXs) cover a role of fundamental importance in normal operation and accidental conditions, being part of the primary and secondary cooling system and of the Decay Heat Removal (DHR) system. It is thus highly relevant to understand the PHXs behavior under all the potential working conditions. In particular, the stability of the PHXs must be guaranteed under all operating conditions. System code models play an important role in understanding and predicting the behavior of the reactor in all conditions, from steady state to operational and accidental transients, and simulating all the postulated scenarios. A solid PHX design requires a complete assessment of two-phase flow instabilities in the secondary system water tube bundle and the potential implementation of a suitable stabilizing device (orifice) to reduce the impact of the perturbations along

  20. [Intermittent bundle branch block: a clinical model for the study of electrophysiological phenomena].

    Science.gov (United States)

    Costantini, Marcello

    2014-01-01

    Disorders of intraventricular conduction (bundle branch block and hemiblock) are usually stable and remain unchanged irrespective of heart rate. Not infrequently, however, their appearance is related to the duration of the cardiac cycle, so that they appear and disappear with changes in heart rate. This may not even represent a pathological phenomenon, since sudden and consistent changes in cardiac cycle can result, even physiologically, in aberrant conduction. However, when a bundle branch block appears intermittently for simple and progressive increments, or even deceleration, of the sinus rate, this is related to a true bundle branch pathology, i.e. tachycardia-dependent (or phase 3) block or bradycardia-dependent (or phase 4) block, respectively. Phase 3 block is believed to express a pathological increase in the duration of the recovery period of the bundle branch. Phase 4 block was best explained on the basis of enhanced phase 4 depolarization of the bundle branch system, with inability of excitation if the cardiac cycle is particularly prolonged. The two types of block, phase 3 and phase 4, often coexist. An intraventricular conduction disturbance that appears during increasing heart rate for a phase 3 block is maintained, if frequency slows down, even for cycles greater than those that brought about its appearance. This is due to retrograde activation of the bundle branch blocked in the antegrade direction, with delay of its action potential inscription. Sometimes, in the presence of phase 3 bundle branch block, very early atrial ectopic beats are paradoxically conducted in the normal way (supernormal conduction). Perhaps, this phenomenon is related to a possible "climb over" of the injured zone of the bundle branch by the blocked impulses that arise beyond the injured area as subliminal impulses, exciting the healthy tissues if catches them during their phase of supernormal excitability. In the presence of intermittent bundle branch block, it is not

  1. Electromagnetic Transients in Power Cables

    DEFF Research Database (Denmark)

    Silva, Filipe Faria Da; Bak, Claus Leth

    of electromagnetic phenomena associated to their operation, among them electromagnetic transients, increased as well. Transient phenomena have been studied since the beginning of power systems, at first using only analytical approaches, which limited studies to more basic phenomena; but as computational tools became...... more powerful, the analyses started to expand for the more complex phenomena. Being old phenomena, electromagnetic transients are covered in many publications, and classic books such as the 40-year-old Greenwood’s ‘‘Electric Transients in Power Systems’’ are still used to this day. However...... example.However, the book is not only intended for students . It can also be used by engineers who work in this area and need to understand the challenges/problems they are facing or who need to learn how to prepare their simulation models as well as their function. It also shows how to calculate...

  2. Transient heating of moving objects

    Directory of Open Access Journals (Sweden)

    E.I. Baida

    2014-06-01

    Full Text Available A mathematical model of transient and quasistatic heating of moving objects by various heat sources is considered. The mathematical formulation of the problem is described, examples of thermal calculation given.

  3. Transient thyrotoxicosis during nivolumab treatment

    NARCIS (Netherlands)

    van Kooten, M. J.; van den Berg, G.; Glaudemans, A. W. J. M.; Hiltermann, T. J. N.; Groen, H. J. M.; Rutgers, A.; Links, T. P.

    Two patients presented with transient thyrotoxicosis within 2-4 weeks after starting treatment with nivolumab. This thyrotoxicosis turned into hypothyroidism within 6-8 weeks. Temporary treatment with a beta blocker may be sufficient.

  4. Transient Tsunamis in Lakes

    Science.gov (United States)

    Couston, L.; Mei, C.; Alam, M.

    2013-12-01

    A large number of lakes are surrounded by steep and unstable mountains with slopes prone to failure. As a result, landslides are likely to occur and impact water sitting in closed reservoirs. These rare geological phenomena pose serious threats to dam reservoirs and nearshore facilities because they can generate unexpectedly large tsunami waves. In fact, the tallest wave experienced by contemporary humans occurred because of a landslide in the narrow bay of Lituya in 1958, and five years later, a deadly landslide tsunami overtopped Lake Vajont's dam, flooding and damaging villages along the lakefront and in the Piave valley. If unstable slopes and potential slides are detected ahead of time, inundation maps can be drawn to help people know the risks, and mitigate the destructive power of the ensuing waves. These maps give the maximum wave runup height along the lake's vertical and sloping boundaries, and can be obtained by numerical simulations. Keeping track of the moving shorelines along beaches is challenging in classical Eulerian formulations because the horizontal extent of the fluid domain can change over time. As a result, assuming a solid slide and nonbreaking waves, here we develop a nonlinear shallow-water model equation in the Lagrangian framework to address the problem of transient landslide-tsunamis. In this manner, the shorelines' three-dimensional motion is part of the solution. The model equation is hyperbolic and can be solved numerically by finite differences. Here, a 4th order Runge-Kutta method and a compact finite-difference scheme are implemented to integrate in time and spatially discretize the forced shallow-water equation in Lagrangian coordinates. The formulation is applied to different lake and slide geometries to better understand the effects of the lake's finite lengths and slide's forcing mechanism on the generated wavefield. Specifically, for a slide moving down a plane beach, we show that edge-waves trapped by the shoreline and free

  5. Numerical Investigation of Characteristic of Anisotropic Thermal Conductivity of Natural Fiber Bundle with Numbered Lumens

    Directory of Open Access Journals (Sweden)

    Guan-Yu Zheng

    2014-01-01

    Full Text Available Natural fiber bundle like hemp fiber bundle usually includes many small lumens embedded in solid region; thus, it can present lower thermal conduction than that of conventional fibers. In the paper, characteristic of anisotropic transverse thermal conductivity of unidirectional natural hemp fiber bundle was numerically studied to determine the dependence of overall thermal property of the fiber bundle on that of the solid region phase. In order to efficiently predict its thermal property, the fiber bundle was embedded into an imaginary matrix to form a unit composite cell consisting of the matrix and the fiber bundle. Equally, another unit composite cell including an equivalent solid fiber was established to present the homogenization of the fiber bundle. Next, finite element thermal analysis implemented by ABAQUS was conducted in the two established composite cells by applying proper thermal boundary conditions along the boundary of unit cell, and influences of the solid region phase and the equivalent solid fiber on the composites were investigated, respectively. Subsequently, an optional relationship of thermal conductivities of the natural fiber bundle and the solid region was obtained by curve fitting technique. Finally, numerical results from the obtained fitted curves were compared with the analytic Hasselman-Johnson’s results and others to verify the present numerical model.

  6. Characterization of midrib vascular bundles of selected medicinal species in Rubiaceae

    Science.gov (United States)

    Nurul-Syahirah, M.; Noraini, T.; Latiff, A.

    2016-11-01

    An anatomical study was carried out on mature leaves of five selected medicinal species of Rubiaceae from Peninsular Malaysia. The chosen medicinal species were Aidia densiflora, Aidia racemosa, Chasallia chartacea, Hedyotis auricularia and Ixora grandifolia. The objective of this study is to determine the taxonomic value of midrib anatomical characteristics. Leaves samples were collected from Taman Paku Pakis, Universiti Kebangsaan Malaysia, Bangi, Selangor and Kledang Saiong Forest Reserve, Perak, Malaysia. Leaves samples then were fixed in spirit and acetic acid (3:1), the midrib parts then were sectioned using sliding microtome, cleared using Clorox, stained in Safranin and Alcian blue, mounted in Euparal and were observed under light microscope. Findings in this study have shown all species have collateral bundles. The midrib vascular bundles characteristics that can be used as tool to differentiate between species or genus are vascular bundles system (opened or closed), shape and arrangement of main vascular bundles, presence of both additional and medullary vascular bundles, position of additional vascular bundles, shape of medullary vascular bundles, presence of sclerenchyma cells ensheathed the vascular bundles. As a conclusion, midrib anatomical characteristics can be used to identify and discriminate medicinal plants species studied in the Rubiaceae.

  7. Unpacking ecosystem service bundles : Towards predictive mapping of synergies and trade-offs between ecosystem services

    NARCIS (Netherlands)

    Spake, Rebecca; Lasseur, Rémy; Crouzat, Emilie; Bullock, James M.; Lavorel, Sandra; Parks, Katherine E.; Schaafsma, Marije; Bennett, Elena M.; Maes, Joachim; Mulligan, Mark; Mouchet, Maud; Peterson, Garry D.; Schulp, Catharina J.E.; Thuiller, Wilfried; Turner, Monica G.; Verburg, Peter H.; Eigenbrod, Felix

    2017-01-01

    Multiple ecosystem services (ES) can respond similarly to social and ecological factors to form bundles. Identifying key social-ecological variables and understanding how they co-vary to produce these consistent sets of ES may ultimately allow the prediction and modelling of ES bundles, and thus,

  8. Local Nucleation of Microtubule Bundles through Tubulin Concentration into a Condensed Tau Phase

    Directory of Open Access Journals (Sweden)

    Amayra Hernández-Vega

    2017-09-01

    Full Text Available Non-centrosomal microtubule bundles play important roles in cellular organization and function. Although many diverse proteins are known that can bundle microtubules, biochemical mechanisms by which cells could locally control the nucleation and formation of microtubule bundles are understudied. Here, we demonstrate that the concentration of tubulin into a condensed, liquid-like compartment composed of the unstructured neuronal protein tau is sufficient to nucleate microtubule bundles. We show that, under conditions of macro-molecular crowding, tau forms liquid-like drops. Tubulin partitions into these drops, efficiently increasing tubulin concentration and driving the nucleation of microtubules. These growing microtubules form bundles, which deform the drops while remaining enclosed by diffusible tau molecules exhibiting a liquid-like behavior. Our data suggest that condensed compartments of microtubule bundling proteins could promote the local formation of microtubule bundles in neurons by acting as non-centrosomal microtubule nucleation centers and that liquid-like tau encapsulation could provide both stability and plasticity to long axonal microtubule bundles.

  9. Local Nucleation of Microtubule Bundles through Tubulin Concentration into a Condensed Tau Phase.

    Science.gov (United States)

    Hernández-Vega, Amayra; Braun, Marcus; Scharrel, Lara; Jahnel, Marcus; Wegmann, Susanne; Hyman, Bradley T; Alberti, Simon; Diez, Stefan; Hyman, Anthony A

    2017-09-05

    Non-centrosomal microtubule bundles play important roles in cellular organization and function. Although many diverse proteins are known that can bundle microtubules, biochemical mechanisms by which cells could locally control the nucleation and formation of microtubule bundles are understudied. Here, we demonstrate that the concentration of tubulin into a condensed, liquid-like compartment composed of the unstructured neuronal protein tau is sufficient to nucleate microtubule bundles. We show that, under conditions of macro-molecular crowding, tau forms liquid-like drops. Tubulin partitions into these drops, efficiently increasing tubulin concentration and driving the nucleation of microtubules. These growing microtubules form bundles, which deform the drops while remaining enclosed by diffusible tau molecules exhibiting a liquid-like behavior. Our data suggest that condensed compartments of microtubule bundling proteins could promote the local formation of microtubule bundles in neurons by acting as non-centrosomal microtubule nucleation centers and that liquid-like tau encapsulation could provide both stability and plasticity to long axonal microtubule bundles. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Adhering to a national surgical care bundle reduces the risk of surgical site infections

    NARCIS (Netherlands)

    Koek, Mayke B. G.; Hopmans, Titia E. M.; Soetens, Loes C.; Wille, Jan C.; Geerlings, Suzanne E.; Vos, Margreet C.; van Benthem, Birgit H. B.; de Greeff, Sabine C.

    2017-01-01

    In 2008, a bundle of care to prevent Surgical Site Infections (SSIs) was introduced in the Netherlands. The bundle consisted of four elements: antibiotic prophylaxis according to local guidelines, no hair removal, normothermia and 'hygiene discipline' in the operating room (i.e. number of door

  11. Adhering to a national surgical care bundle reduces the risk of surgical site infections

    NARCIS (Netherlands)

    Koek, M.B.G. (Mayke B. G.); Hopmans, T.E.M. (Titia E. M.); Soetens, L.C. (Loes C.); J.C. Wille (Jan); S.E. Geerlings (Suzanne); M.C. Vos (Margreet); B.H. van Benthem (Birgit); S.C. de Greeff (Sabine C.)

    2017-01-01

    textabstractBackground: In 2008, a bundle of care to prevent Surgical Site Infections (SSIs) was introduced in the Netherlands. The bundle consisted of four elements: antibiotic prophylaxis according to local guidelines, no hair removal, normothermia and ‘hygiene discipline’

  12. Left Bundle Branch Block and Complete Heart Block Complicating Inferior Myocardial Infarction.

    Science.gov (United States)

    Gruber, Jillian S; Stair, Brad; Aktas, Mehmet; Bravo-Jaimes, Katia

    2017-01-01

    Left bundle branch block following inferior myocardial infarction remains uncommon and scarcely reported in the literature. We describe a rare presentation of a 58-year-old male patient who developed left bundle branch block and third degree atrioventricular block after inferior myocardial infarction requiring permanent pacemaker placement. Pathophysiology, impact on mortality, and management options are discussed. © 2016 Wiley Periodicals, Inc.

  13. To Be or Not To Be: The Existential Issue for National Governance Bundles

    NARCIS (Netherlands)

    Millar-Schijf, Carla C.J.M.

    2014-01-01

    Research Question/Issue The article addresses the issue of whether governance bundles which include both formal and informal governance mechanisms should be classified and compared on the basis of national identity. Research Findings/Insights The governance bundle affecting each firm has formal

  14. On the non-existence of orthogonal instanton bundles on P^{2n+1}

    Directory of Open Access Journals (Sweden)

    Łucja Farnik

    2009-11-01

    Full Text Available In this paper we prove that there do not exist orthogonal instanton bundles on P^{2n+1} . In order to demonstrate this fact, we propose a new way of representing the invariant, introduced by L. Costa and G. Ottaviani, related to a rank 2n instanton bundle on P^{2n+1}.

  15. Engineering the bundled glass column: From the design concept to full-scale experimental testing

    NARCIS (Netherlands)

    Oikonomopoulou, F.; Bristogianni, T.; Veer, F.A.; Nijsse, R.

    This article gives an overview of the research conducted by the authors from the design concept to the engineering and full-scale testing of the bundled glass column. Consisting of adhesively bonded solid glass rods, the bundled column is a promising solution for transparent compressive members. To

  16. Implementing a Sepsis Resuscitation Bundle Improved Clinical Outcome: A Before-and-After Study

    Directory of Open Access Journals (Sweden)

    Jeongmin Kim

    2014-11-01

    CONCLUSIONS: Repeated education led by a multidisciplinary team and interdisciplinary communication improved the compliance rate of the 6-h resuscitation bundle in severe sepsis and septic shock patients. Compliance with the sepsis resuscitation bundle was associated with improved 28-day mortality in the study population.

  17. "The Purpose of This Study Is to": Connecting Lexical Bundles and Moves in Research Article Introductions

    Science.gov (United States)

    Cortes, Viviana

    2013-01-01

    This article presents a group of lexical bundles identified in a corpus of research article introductions as the first step in the analysis of these expressions in the different sections of the research article. A one-million word corpus of research article introductions from various disciplines was compiled and the lexical bundles identified in…

  18. Constructed microhabitat bundles for sampling fishes and crayfishes in coastal plain streams

    Science.gov (United States)

    Melvin L. Warren; A.L. Sheldon; W.R. Haag

    2009-01-01

    We investigated fish and crayfish use of standardized, constructed microhabitats (bundles) in three northern Mississippi streams. Cypress Creek and the Little Tallahatchie Canal were channelized and incised and had little woody cover; Puskus Creek was unchannelized and unincised and had abundant woody cover. We constructed three types of bundles (cane, leaf, and string...

  19. A simulation study on the adsorption properties of linear alkanes on closed nanotube bundles

    NARCIS (Netherlands)

    Cannon, J.J.; Vlugt, T.J.H.; Dubbeldam, D.; Maruyama, S.; Shiomi, J.

    2012-01-01

    Adsorption onto carbon nanotube bundles may find use in various applications such as gas pre-concentration and separation, and as a result it is of great interest to study the adsorption properties of such bundles. The adsorption of linear alkanes, with their systematic variation through chain

  20. Atrial fibrillation with intermittent right axis deviation in the presence of complete left bundle branch block.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Di Bella, Gianluca; Chiribiri, Amedeo

    2008-09-16

    Left bundle branch block is usually associated with normal or left axis deviation. Rarely the ecg shows an LBBB with changing QRS morphology and changing axis deviation. We describe a case of atrial fibrillation with intermittent right axis deviation in the presence of complete left bundle branch block in an 84-year-old Italian woman in the Cardiology Unit.

  1. The determinant bundle on the moduli space of stable triples over a ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    bundles over a Riemann surface and also on the existence of a special metric on a stable triple established in [BG]. Here is a brief outline of the contents of the paper. In §2, we recall the basic notions about holomorphic triples, their stability, and their moduli spaces. In §3, we construct a natural holomorphic line bundle L on ...

  2. Vector bundles with a fixed determinant on an irreducible nodal curve

    Indian Academy of Sciences (India)

    sheaves with a fixed determinant in the moduli space of torsion-free sheaves on Y. The relation to Seshadri–Nagaraj conjecture is studied. Keywords. Nodal curves; torsion-free sheaves; fixed determinant. 1. Introduction. Generalized parabolic vector bundles (GPBs) on a smooth curve X are vector bundles on. X together ...

  3. GPU acceleration of the stochastic grid bundling method for early-exercise options

    NARCIS (Netherlands)

    A. Leitao Rodriguez (Álvaro); C.W. Oosterlee (Cornelis)

    2015-01-01

    htmlabstractIn this work, a parallel graphics processing units (GPU) version of the Monte Carlo stochastic grid bundling method (SGBM) for pricing multi-dimensional early-exercise options is presented. To extend the method’s applicability, the problem dimensions and the number of bundles will be

  4. Unwrapping the Bundle: An Examination of Research Libraries and the "Big Deal"

    Science.gov (United States)

    Strieb, Karla L.; Blixrud, Julia C.

    2014-01-01

    This study presents and analyzes the findings of a 2012 survey of member libraries belonging to the Association of Research Libraries (ARL) about publishers' large journal bundles and compares the results to earlier surveys. The data illuminate five research questions: market penetration, journal bundle construction, collection format shifts,…

  5. Voltage clamp simulations for multifiber bundles in a double sucrose gap: cable complications.

    Science.gov (United States)

    Solchenbach, K; Haas, H G; Brommundt, G

    1986-10-01

    A theoretical model is presented for voltage clamp of a bundle of cylindrical excitable cells in a double sucrose gap. The preparation in the test node is represented by a single one-dimensional cable (length/diameter ratio approximately) with standard Hodgkin-Huxley kinetics for transmembrane Na current. Imperfections of voltage control due to internal (longitudinal) resistivity and external (radial) resistance in series to the membrane are analysed. The electrical behavior of a fiber is described by the cable equation with appropriate boundary conditions and subsidiary equations reflecting the membrane characteristics. Membrane voltage and current distribution in response to a step command was obtained by numerical integration. The results are described in two papers. The present paper deals with the effect of internal resistivity with the external resistance being neglected. The closed loop response of a fiber displays a strong tendency to oscillate. To stabilize the system a phase lead was inserted and the gain of the control amplifier was reduced. Conditions for stability were examined by Nyquist analysis. When the Na system was activated by a command pulse below ENa, a voltage gradient developed between a depolarization (relative to the command signal) at the end where voltage was monitored and a hyperpolarization at the site of current injection. In spite of a poor voltage control the total measured current appeared to have a smooth transient. With large voltage gradients a small, second inward current was seen. At a low (high) Na conductance maximum peak inward current was larger (smaller) that the current expected from ideal space clamping.

  6. Single and two-phase flow pressure drop for CANFLEX bundle

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joo Hwan; Jun, Ji Su; Suk, Ho Chun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Dimmick, G. R.; Bullock, D. E. [Atomic Energy of Canada Limited, Ontario (Canada)

    1998-12-31

    Friction factor and two-phase flow frictional multiplier for a CANFLEX bundle are newly developed and presented in this paper. CANFLEX as a 43-element fuel bundle has been developed jointly by AECL/KAERI to provide greater operational flexibility for CANDU reactor operators and designers. Friction factor and two-phase flow frictional multiplier have been developed by using the experimental data of pressure drops obtained from two series of Freon-134a (R-134a) CHF tests with a string of simulated CANFLEX bundles in a single phase and a two-phase flow conditions. The friction factor for a CANFLEX bundle is found to be about 20% higher than that of Blasius for a smooth circular pipe. The pressure drop predicted by using the new correlations of friction factor and two-phase frictional multiplier are well agreed with the experimental pressure drop data of CANFLEX bundle within {+-} 5% error. 11 refs., 5 figs. (Author)

  7. Hexagonally Ordered Arrays of α-Helical Bundles Formed from Peptide-Dendron Hybrids

    Energy Technology Data Exchange (ETDEWEB)

    Barkley, Deborah A. [Department; Rokhlenko, Yekaterina [Department; Marine, Jeannette E. [Department; David, Rachelle [Department; Sahoo, Dipankar [Department; Watson, Matthew D. [Department; Koga, Tadanori [Department; Department; Osuji, Chinedum O. [Department; Rudick, Jonathan G. [Department

    2017-10-24

    Combining monodisperse building blocks that have distinct folding properties serves as a modular strategy for controlling structural complexity in hierarchically organized materials. We combine an α-helical bundle-forming peptide with self-assembling dendrons to better control the arrangement of functional groups within cylindrical nanostructures. Site-specific grafting of dendrons to amino acid residues on the exterior of the α-helical bundle yields monodisperse macromolecules with programmable folding and self-assembly properties. The resulting hybrid biomaterials form thermotropic columnar hexagonal mesophases in which the peptides adopt an α-helical conformation. Bundling of the α-helical peptides accompanies self-assembly of the peptide-dendron hybrids into cylindrical nanostructures. The bundle stoichiometry in the mesophase agrees well with the size found in solution for α-helical bundles of peptides with a similar amino acid sequence.

  8. A GRAPH BASED BUNDLE ADJUSTMENT FOR INS-CAMERA CALIBRATION

    Directory of Open Access Journals (Sweden)

    D. Bender

    2013-08-01

    Full Text Available In this paper, we present a graph based approach for performing the system calibration of a sensor suite containing a fixed mounted camera and an inertial navigation system. The aim of the presented work is to obtain accurate direct georeferencing of camera images collected with small unmanned aerial systems. Prerequisite for using the pose measurements from the inertial navigation system as exterior orientation for the camera is the knowledge of the static offsets between these devices. Furthermore, the intrinsic parameters of the camera obtained in a laboratory tend to deviate slightly from the values during flights. This induces an in-flight calibration of the intrinsic camera parameters in addition to the mounting offsets between the two devices. The optimization of these values can be done by introducing them as parameters into a bundle adjustment process. We show how to solve this by exploiting a graph optimization framework, which is designed for the least square optimization of general error functions.

  9. a Graph Based Bundle Adjustment for Ins-Camera Calibration

    Science.gov (United States)

    Bender, D.; Schikora, M.; Sturm, J.; Cremers, D.

    2013-08-01

    In this paper, we present a graph based approach for performing the system calibration of a sensor suite containing a fixed mounted camera and an inertial navigation system. The aim of the presented work is to obtain accurate direct georeferencing of camera images collected with small unmanned aerial systems. Prerequisite for using the pose measurements from the inertial navigation system as exterior orientation for the camera is the knowledge of the static offsets between these devices. Furthermore, the intrinsic parameters of the camera obtained in a laboratory tend to deviate slightly from the values during flights. This induces an in-flight calibration of the intrinsic camera parameters in addition to the mounting offsets between the two devices. The optimization of these values can be done by introducing them as parameters into a bundle adjustment process. We show how to solve this by exploiting a graph optimization framework, which is designed for the least square optimization of general error functions.

  10. Sachs equations for light bundles in a cold plasma

    Science.gov (United States)

    Schulze-Koops, Karen; Perlick, Volker; Schwarz, Dominik J.

    2017-11-01

    We study the propagation of light bundles in non-empty spacetime, as most of the Universe is filled by baryonic matter in the form of a (dilute) plasma. Here we restrict to the case of a cold (i.e. pressureless) and non-magnetised plasma. Then the influence of the medium on the light rays is encoded in the spacetime dependent plasma frequency. Our result for a general spacetime generalises the Sachs equations to the case of a cold plasma Universe. We find that the reciprocity law (Etherington theorem), the relation that connects area distance with luminosity distance, is modified. Einstein’s field equation is not used, i.e. our results apply independently of whether or not the plasma is self-gravitating. As an example, our findings are applied to a homogeneous plasma in a Robertson-Walker spacetime. We find small modifications of the cosmological redshift of frequencies and of the Hubble law.

  11. Anticommons, the Coase Theorem and the problem of bundling inefficiency

    Directory of Open Access Journals (Sweden)

    Ivan Major

    2016-02-01

    Full Text Available The Coase theorem is most often formulated in terms of bi-lateral monopoly, for instance between a polluting factory and an affected neighbour.  Instead, we introduce multiple affected neighbours and the concept of anticommons, in which autonomous actors with separate yet necessarily complementary inputs each has the right to deny but not to permit use.  Once we posit multiple owners possessing complementary rights, strategically maximizing against each other as well as against the actor who wishes to purchase a portion of that right, the outcome is neither efficient nor invariant.  Our finding, based on non-cooperative game theory, is sustained even under the restrictive Coase assumptions regarding complete information, perfect rationality, and zero transaction costs. The implication is that suboptimal bundling agreements in cases of multiple stakeholders is not the mere product of market imperfection, but instead is a systematic result.

  12. Rare Manifestation of Digoxin Toxicity: Right Bundle Branch Block

    Science.gov (United States)

    Gill, Dalvir; Zaidi, Samana

    2016-01-01

    A 76-year-old female, with medical history significant for systolic congestive heart failure, who presented to the emergency department with lethargy and abdominal pain with diarrhea for the past 3 weeks. Due to hypotension, the patient received multiple boluses of isotonic saline and was started on norepinephrine. Laboratories were significant for severe digoxin toxicity (29 ng/mL), in setting of acute kidney injury. Electrocardiogram (EKG) revealed a new right bundle branch block (RBBB). She was given Digibind and her repeat digoxin level was 20 ng/mL. Repeat EKG showed resolved RBBB. This case identifies that patients with digoxin toxicity are at risk for RBBB. This is a rare finding and is not commonly recognized. Emergency medicine physicians are often the first to encounter patients with digoxin toxicity and need to be aware of such EKG findings. PMID:28104974

  13. Intermittent left bundle branch block caused by coronary vasospasm

    Science.gov (United States)

    Alhaji, Mohammad

    2013-01-01

    Intermittent left bundle branch block (LBBB) has been reported in the literature following certain conditions such as cardiac blunt trauma, myocardial infarction (MI) or exercise induced LBBB. In the majority of cases, the patients usually have underlying coronary arteries disease. LBBB often prevents the electrocardiographic diagnosis of acute MI; therefore, new LBBB in the setting of chest pain is usually treated as transmural MI. We describe a case of patient who presented with intermittent LBBB associated with chest pain, and subsequently the patient was taken to the catheterization laboratory for emergency coronary angiogram, which revealed 80% spasm in left anterior descending artery, which was totally relieved by nitroglycerin infusion. No other significant CAD was noted. PMID:23930243

  14. Modified Einstein and Finsler Like Theories on Tangent Lorentz Bundles

    CERN Document Server

    Stavrinos, Panayiotis; Vacaru, Sergiu I.

    2014-01-01

    We study modifications of general relativity, GR, with nonlinear dispersion relations which can be geometrized on tangent Lorentz bundles. Such modified gravity theories, MGTs, can be modeled by gravitational Lagrange density functionals $f(\\mathbf{R},\\mathbf{T},F)$ with generalized/ modified scalar curvature $\\mathbf{R}$, trace of matter field tensors $\\mathbf{T}$ and modified Finsler like generating function $F$. In particular, there are defined extensions of GR with extra dimensional "velocity/ momentum" coordinates. For four dimensional models, we prove that it is possible to decouple and integrate in very general forms the gravitational fields for $f(\\mathbf{R},\\mathbf{T},F)$--modified gravity using nonholonomic 2+2 splitting and nonholonomic Finsler like variables $F$. We study the modified motion and Newtonian limits of massive test particles on nonlinear geodesics approximated with effective extra forces orthogonal to the four-velocity. We compute the constraints on the magnitude of extra-acceleration...

  15. Design of electric control system for automatic vegetable bundling machine

    Science.gov (United States)

    Bao, Yan

    2017-06-01

    A design can meet the requirements of automatic bale food structure and has the advantages of simple circuit, and the volume is easy to enhance the electric control system of machine carrying bunch of dishes and low cost. The bundle of vegetable machine should meet the sensor to detect and control, in order to meet the control requirements; binding force can be adjusted by the button to achieve; strapping speed also can be adjusted, by the keys to set; sensors and mechanical line connection, convenient operation; can be directly connected with the plug, the 220V power supply can be connected to a power source; if, can work, by the transmission signal sensor, MCU to control the motor, drive and control procedures for small motor. The working principle of LED control circuit and temperature control circuit is described. The design of electric control system of automatic dish machine.

  16. Spent fuel bundle counter sequence error manual - BRUCE NGS

    Energy Technology Data Exchange (ETDEWEB)

    Nicholson, L.E

    1992-03-20

    The Spent Fuel Bundle Counter (SFBC) is used to count the number and type of spent fuel transfers that occur into or out of controlled areas at CANDU reactor sites. However if the transfers are executed in a non-standard manner or the SFBC is malfunctioning, the transfers are recorded as sequence errors. Each sequence error message typically contains adequate information to determine the cause of the message. This manual provides a guide to interpret the various sequence error messages that can occur and suggests probable cause or causes of the sequence errors. Each likely sequence error is presented on a 'card' in Appendix A. Note that it would be impractical to generate a sequence error card file with entries for all possible combinations of faults. Therefore the card file contains sequences with only one fault at a time. Some exceptions have been included however where experience has indicated that several faults can occur simultaneously.

  17. Spent fuel bundle counter sequence error manual - DARLINGTON NGS

    Energy Technology Data Exchange (ETDEWEB)

    Nicholson, L.E

    1992-03-25

    The Spent Fuel Bundle Counter (SFBC) is used to count the number and type of spent fuel transfers that occur into or out of controlled areas at CANDU reactor sites. However if the transfers are executed in a non-standard manner or the SFBC is malfunctioning, the transfers are recorded as sequence errors. Each sequence error message typically contains adequate information to determine the cause of the message. This manual provides a guide to interpret the various sequence error messages that can occur and suggests probable cause or causes of the sequence errors. Each likely sequence error is presented on a 'card' in Appendix A. Note that it would be impractical to generate a sequence error card file with entries for all possible combinations of faults. Therefore the card file contains sequences with only one fault at a time. Some exceptions have been included however where experience has indicated that several faults can occur simultaneously.

  18. Ion-irradiation-induced defects in bundles of carbon nanotubes

    CERN Document Server

    Salonen, E; Nordlund, K

    2002-01-01

    We study the structure and formation yields of atomic-scale defects produced by low-dose Ar ion irradiation in bundles of single-wall carbon nanotubes. For this, we employ empirical potential molecular dynamics and simulate ion impact events over an energy range of 100-1000 eV. We show that the most common defects produced at all energies are vacancies on nanotube walls, which at low temperatures are metastable but long-lived defects. We further calculate the spatial distribution of the defects, which proved to be highly non-uniform. We also show that ion irradiation gives rise to the formations of inter-tube covalent bonds mediated by carbon recoils and nanotube lattice distortions due to dangling bond saturation. The number of inter-tube links, as well as the overall damage, linearly grows with the energy of incident ions.

  19. Ultrasonographic evaluation of displaced neurovascular bundle in Dupuytren disease.

    Science.gov (United States)

    Uehara, Kosuke; Miura, Toshiki; Morizaki, Yutaka; Miyamoto, Hideaki; Ohe, Takashi; Tanaka, Sakae

    2013-01-01

    Neurovascular injury is a serious complication after surgery for Dupuytren disease. The purpose of this study was to evaluate the relationship between the cord and the neurovascular bundle ultrasonographically. We included 22 healthy volunteers and 14 Dupuytren disease patients (25 fingers) in this study. We evaluated the cord and the digital artery with high-resolution ultrasound. We first investigated the effect of the angle of metacarpophalangeal joint on the position of the radial and ulnar digital arteries in volunteers without evidence of Dupuytren disease. We compared 3 parameters of the radial and ulnar digital arteries, including differences in depth, differences in lateral shift, and the shape of the cross-section of the artery, between volunteers and patients with Dupuytren disease. None of these parameters changed with flexion of the metacarpophalangeal joint of 0°, 30°, and 60°. Digital arteries and cords could be identified ultrasonographically in all patients, and we confirmed ultrasonographic findings by operative findings in 13 fingers. We classified the fingers into 3 subgroups based on the ultrasonographic findings: type A (n = 13), in which the cord was above the artery; type B (n = 5), in which the cord was below the artery; and type C (n = 7), in which the cord was located between the radial and ulnar digital arteries. Types A, B, and C corresponded to natatory cord/abductor digiti minimi cord, spiral cord, and central cord, respectively. Comparisons among volunteers and patient subgroups showed that the difference in depth in type B patients was significantly larger than that of the other groups. When we set the cutoff point of the difference in depth to 3 mm, sensitivity and specificity to detect the spiral cord were 80% and 76%, respectively. The relationship between the neurovascular bundle and the type of Dupuytren disease cord can be evaluated by high-resolution ultrasound. Diagnostic III. Copyright © 2013 American Society for

  20. Critical Power in 7-Rod Tight Lattice Bundle

    Science.gov (United States)

    Liu, Wei; Kureta, Masatoshi; Akimoto, Hajime

    The Reduced-Moderation Water Reactor (RMWR) has recently becomes of great concern. The RMWR is expected to promote the effective utilization of uranium recourse. The RMWR is based on water-cooled reactor technology, with achieved under lower core water volume and water flow rate. In comparison with the current light water reactors whose water-to-fuel volume ratio is about 2-3, in the RMWR, this value is reduced to less than 0.5. Thereby, there is a need to research its cooling characteristics. Experimental research on critical power in tight lattice bundle that simulates the RMWR has been carried out in Japan Atomic Energy Research Institute (JAERI). The bundle consists one center rod and six peripheral rods. The 7 rods are arranged on a 14.3mm equilateral triangular pitch. Each rod is 13mm in outside diameter. An axial 12-step power distribution is employed to simulate the complicate heating condition in RMWR. Experiments are carried out under G=100-1400kg/m2s, Pex=2-8.5MPa. Effects of mass velocity, inlet temperature, pressure, radial peaking factor and axial peaking factor on critical power and critical quality are discussed. Compared with axial uniform heating condition, the axial non-uniform heating condition causes an obvious decrease in critical quality. Arai correlation, which is the only correlation that has been optimized for tight lattice condition, is verified with the present experimental data. The correlation is found to be able to give reasonable prediction only around RMWR nominal operating condition.

  1. Anatomical Double-Bundle Coracoclavicular Reconstruction in Chronic Acromioclavicular Dislocation.

    Science.gov (United States)

    Lee, Sang Ki; Song, Dae Geon; Choy, Won Sik

    2015-08-01

    The purpose of this study was to evaluate the clinical and radiological outcomes of anatomical double-bundle coracoclavicular (CC) reconstruction using the coracoacromial (CA) ligament and the conjoined tendon for the treatment of chronic acromioclavicular (AC) joint dislocation. A retrospective evaluation was performed on 18 patients who underwent an anatomical CC reconstruction using the CA ligament and the conjoined tendon for chronic AC joint dislocation. Patients were treated surgically between April 2007 and January 2012. Mean follow-up was 35.3 months (range, 24-49 months). All patients were evaluated for functional outcomes using the modified University of California, Los Angeles (UCLA) shoulder rating scale for chronic AC injury and the Constant-Murley shoulder outcome score. Range of motion and shoulder and elbow strength were also measured. Plain radiographs were taken to evaluate reduction status and CC distance. Mean modified UCLA shoulder rating scale at final follow-up was 18.1 points (range, 13-20 points). No significant difference in mean Constant-Murley scores existed between the injured and contralateral shoulders (P=.26). At final follow-up, 15 (83.3%) patients had well-maintained reduction and 2 (11.1%) patients had a partial loss of reduction. One other patient had a complete loss of reduction due to a postoperative fall. The CC distance was not significantly different between the injured and contralateral shoulders in the immediate postoperative period (P=.46) or at final follow-up (P=.14). One superficial wound infection occurred and was treated with routine wound care. An anatomical double-bundle CC reconstruction using the CA ligament and the conjoined tendon for the treatment of chronic AC joint dislocation is a reliable surgical method with good results. Copyright 2015, SLACK Incorporated.

  2. The severe sepsis bundles as processes of care: a meta-analysis.

    Science.gov (United States)

    Chamberlain, Diane J; Willis, Eileen M; Bersten, Andrew B

    2011-11-01

    The use of the sepsis bundles in patients with severe sepsis and septic shock has been controversial in the last decade. Clinical studies have reported beneficial, as well as negative results. We conducted a meta-analysis to assess the clinical evidence and to evaluate survival effects. Database searches (2004-current) of Medline, CINAHL, Pubmed, Cochrane, Scopus and Google scholar databases which covered full publications, abstracts from conferences and digital thesis were performed using the search terms sepsis, septic shock and/or bundles, processes of care, guidelines, early goal directed therapy, resuscitation. From 253 identified studies, 21 sepsis bundle original studies were selected and included 23,438 patients. The Resuscitation 6 hour Bundle pooled analysis (1819 patients) achieved the greatest survival benefit (odds ratio (OR) 2.124, 95% CI 1.701-2.651, p<0.000) with the Management 24 hour Bundle pooled analysis the lowest survival benefit (16,521 patients) (OR 1.646, 95% CI 1.036-2.614, p<0.035). Both bundles together (Complete Bundle) achieved a combined survival benefit (OR 1.744, 95% CI 1.421-2.141, p<0.000). ScvO2 and blood glucose components were analysed individually to assess their contribution to survival. The Resuscitation 6 hour bundle in the context of the patient population at hand is unlikely to do harm and is yet to be established in primary research in Australia. The Management 24 hour Bundle could not establish a strong enough survival benefit above current routine practice. The sepsis guidelines and bundles have demanded more credible process measurements and debate to induce positive changes in the intervention and treatment care of patients with severe sepsis. Copyright © 2011 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.

  3. Evidence for two populations of hair bundles in the sea anemone, Nematostella vectensis.

    Science.gov (United States)

    Menard, Shelcie S; Watson, Glen M

    2017-06-01

    Cytochalasin D (CD) was employed to disrupt F-actin within stereocilia of anemone hair bundles. CD treatment decreases the abundance of hair bundles (by 85%) while significantly impairing predation. The remaining hair bundles are 'CD-resistant.' Surprisingly, the morphology and F-actin content of resistant hair bundles are comparable to those of untreated controls. However, the resistant hair bundles fail to respond normally to the N-acetylated sugar, NANA, by elongating. Instead, they remain at resting length. Immediately after CD treatment, when only CD-resistant hair bundles are present, nematocyst discharge is normal into targets touched to tentacles in the absence of vibrations (i.e., baseline) but fails to increase normally in the presence of nearby vibrations at 56Hz, a key frequency. After CD treatment, the abundance of hair bundles recovers to control levels within three hours. At 2h after CD treatment, when CD-resistant and CD-sensitive hair bundles are both present, but a full-recovery is not yet complete, somewhat enhanced discharge of nematocysts occurs into targets touched to tentacles in the presence of nearby vibrations at 56Hz (at least as compared to the response of CD-treated animals to contact with test probes in the absence of vibrations). Additionally, at 2h after CD-treatment, prey capture recovers to normal. Thus, two populations of hair bundles may be present on tentacles of sea anemones: those that are CD-resistant and those that are CD-sensitive. The functions of these hair bundles may be distinct. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Molecular mechanism of bundle formation by the bacterial actin ParM

    Energy Technology Data Exchange (ETDEWEB)

    Popp, David, E-mail: dpopp@imcb.a-star.edu.sg [ERATO ' Actin Filament Dynamics' Project, Japan Science and Technology Corporation, c/o RIKEN Harima Institute at Spring 8, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, 138673 Singapore (Singapore); Narita, Akihiro [ERATO ' Actin Filament Dynamics' Project, Japan Science and Technology Corporation, c/o RIKEN Harima Institute at Spring 8, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Nagoya University Graduate School of Science, Structural Biology Research Center and Division of Biological Sciences, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Iwasa, Mitsusada [ERATO ' Actin Filament Dynamics' Project, Japan Science and Technology Corporation, c/o RIKEN Harima Institute at Spring 8, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Maeda, Yuichiro [ERATO ' Actin Filament Dynamics' Project, Japan Science and Technology Corporation, c/o RIKEN Harima Institute at Spring 8, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Nagoya University Graduate School of Science, Structural Biology Research Center and Division of Biological Sciences, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Robinson, Robert C. [Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, 138673 Singapore (Singapore)

    2010-01-22

    The actin homolog ParM plays a microtubule-like role in segregating DNA prior to bacterial cell division. Fluorescence and cryo-electron microscopy have shown that ParM forms filament bundles between separating DNA plasmids in vivo. Given the lack of ParM bundling proteins it remains unknown how ParM bundles form at the molecular level. Here we show using time-lapse TIRF microscopy, under in vitro molecular crowding conditions, that ParM-bundle formation consists of two distinct phases. At the onset of polymerization bundle thickness and shape are determined in the form of nuclei of short helically disordered filaments arranged in a liquid-like lattice. These nuclei then undergo an elongation phase whereby they rapidly increase in length. At steady state, ParM bundles fuse into one single large aggregate. This behavior had been predicted by theory but has not been observed for any other cytomotive biopolymer, including F-actin. We employed electron micrographs of ParM rafts, which are 2-D analogs of 3-D bundles, to identify the main molecular interfilament contacts within these suprastructures. The interface between filaments is similar for both parallel and anti-parallel orientations and the distribution of filament polarity is random within a bundle. We suggest that the interfilament interactions are not due to the interactions of specific residues but rather to long-range, counter ion mediated, electrostatic attractive forces. A randomly oriented bundle ensures that the assembly is rigid and that DNA may be captured with equal efficiency at both ends of the bundle via the ParR binding protein.

  5. Bundling in Place: Translating the NGSS into Place-Based Earth-System Science Curricula

    Science.gov (United States)

    Semken, S. C.

    2016-12-01

    Bundling is the process of grouping Performance Expectations (PEs) from the Next Generation Science Standards (NGSS) into coherent units based on a defined topic, idea, question, or phenomenon. Bundling sorts the PEs for a given grade or grade band into a teachable narrative: a key stage in building curriculum, instruction, and assessment from the NGSS. To encourage and facilitate this, bundling guidelines have recently been released on the NGSS website (nextgenscience.org/glossary/bundlesbundling), and example bundles for different grade bands and disciplines are also being developed and posted there. According to these guidelines the iterative process of bundling begins with organization of PEs according to natural connections among them, and alignment of the three NGSS dimensions (Disciplinary Core Ideas, Cross-Cutting Concepts, and Science and Engineering Practices) that underpin each PE. Bundles are grouped by coherence and increasing complexity into courses, and courses into course sets that should encompass all PEs for a grade band. Bundling offers a natural way to translate the NGSS into highly contextualized curricula such as place-based (PB) teaching, which is situated in specific places or regions and focused on natural and cultural features, processes, phenomena, history, and challenges to sustainability therein. Attributes of place and our individual and collective connections to place (sense of place) directly inform PB curriculum, pedagogy, and assessment. PEs can be bundled by their relevance to these themes. Following the NGSS guidelines, I model the process for PB instruction by bundling PEs around the themes of Paleozoic geology and carbonate deposition and their relationships to mining and calcining of limestone in Anthropocene cement production for developing communities. The bundles integrate aspects of Earth history, the carbon cycle, mineral resources, climate change, and sustainability using specific local examples and narratives. They are

  6. Translating Pressure Ulcer Prevention Into Intensive Care Nursing Practice: Overlaying a Care Bundle Approach With a Model for Research Implementation.

    Science.gov (United States)

    Tayyib, Nahla; Coyer, Fiona

    This article reports on the development and implementation process used to integrate a care bundle approach (a pressure ulcer [PU] prevention bundle to improve patients' skin integrity in intensive care) and the Ottawa Model of Research Use (OMRU). The PU prevention care bundle demonstrated significant reduction in PU incidence, with the OMRU model providing a consolidated framework for the implementation of bundled evidence in an effective and consistent manner into daily clinical nursing practice.

  7. Recent development of transient electronics

    Directory of Open Access Journals (Sweden)

    Huanyu Cheng

    2016-01-01

    Full Text Available Transient electronics are an emerging class of electronics with the unique characteristic to completely dissolve within a programmed period of time. Since no harmful byproducts are released, these electronics can be used in the human body as a diagnostic tool, for instance, or they can be used as environmentally friendly alternatives to existing electronics which disintegrate when exposed to water. Thus, the most crucial aspect of transient electronics is their ability to disintegrate in a practical manner and a review of the literature on this topic is essential for understanding the current capabilities of transient electronics and areas of future research. In the past, only partial dissolution of transient electronics was possible, however, total dissolution has been achieved with a recent discovery that silicon nanomembrane undergoes hydrolysis. The use of single- and multi-layered structures has also been explored as a way to extend the lifetime of the electronics. Analytical models have been developed to study the dissolution of various functional materials as well as the devices constructed from this set of functional materials and these models prove to be useful in the design of the transient electronics.

  8. Pre-test analysis of protected loss of primary pump transients in CIRCE-HERO facility

    Science.gov (United States)

    Narcisi, V.; Giannetti, F.; Del Nevo, A.; Tarantino, M.; Caruso, G.

    2017-11-01

    In the frame of LEADER project (Lead-cooled European Advanced Demonstration Reactor), a new configuration of the steam generator for ALFRED (Advanced Lead Fast Reactor European Demonstrator) was proposed. The new concept is a super-heated steam generator, double wall bayonet tube type with leakage monitoring [1]. In order to support the new steam generator concept, in the framework of Horizon 2020 SESAME project (thermal hydraulics Simulations and Experiments for the Safety Assessment of MEtal cooled reactors), the ENEA CIRCE pool facility will be refurbished to host the HERO (Heavy liquid mEtal pRessurized water cOoled tubes) test section to investigate a bundle of seven full scale bayonet tubes in ALFRED-like thermal hydraulics conditions. The aim of this work is to verify thermo-fluid dynamic performance of HERO during the transition from nominal to natural circulation condition. The simulations have been performed with RELAP5-3D© by using the validated geometrical model of the previous CIRCE-ICE test section [2], in which the preceding heat exchanger has been replaced by the new bayonet bundle model. Several calculations have been carried out to identify thermal hydraulics performance in different steady state conditions. The previous calculations represent the starting points of transient tests aimed at investigating the operation in natural circulation. The transient tests consist of the protected loss of primary pump, obtained by reducing feed-water mass flow to simulate the activation of DHR (Decay Heat Removal) system, and of the loss of DHR function in hot conditions, where feed-water mass flow rate is absent. According to simulations, in nominal conditions, HERO bayonet bundle offers excellent thermal hydraulic behavior and, moreover, it allows the operation in natural circulation.

  9. Explosive and Radio-Selected Transients: Transient Astronomy with ...

    Indian Academy of Sciences (India)

    In India, active research is going on in transient astronomy, especially in the fields of supernovae, gamma ray .... to ∼9 as of now. We currently understand them as catastrophic events generating a central engine which ..... bubbles blown by hot progenitor or with complex circumstellar environments set up by variable winds.

  10. Explosive and Radio-Selected Transients: Transient Astronomy with ...

    Indian Academy of Sciences (India)

    Therefore, multiwaveband observational efforts with wide fields of view will be the key to progress of transients astronomy from the middle 2020s offering unprecedented deep images and high spatial and spectral resolutions. Radio observations of Gamma Ray Bursts (GRBs) with SKA will uncover not only much fainter ...

  11. Association between cingulum bundle structure and cognitive performance: an observational study in major depression.

    Science.gov (United States)

    Schermuly, I; Fellgiebel, A; Wagner, S; Yakushev, I; Stoeter, P; Schmitt, R; Knickenberg, R J; Bleichner, F; Beutel, M E

    2010-10-01

    Major depression can be regarded as a systemic neurobehavioral disorder resulting from dysfunction of the limbic-cortical networks. The cingulum bundle represents a major association fiber tract of those networks. The aim of our study was to determine the association of brain structural tissue markers of the cingulum bundle and cognitive function in patients with major depression. Region-of-interest-based analyses of the middle-anterior and middle-posterior cingulum bundle fractional anisotropy (FA) and mean diffusivity (MD) using color-coded diffusion-tensor imaging and neuropsychological assessment in 14 patients with major depression. FA of the middle-anterior and middle-posterior cingulum bundle was significantly correlated to the performance in a planning and divided attention task. Furthermore, MD of the middle-posterior cingulum bundle was significantly correlated to a planning task. There was no significant correlation between FA and MD of the cingulum bundle and selective attention or memory. Brain structural tissue markers of the middle-anterior and middle-posterior cingulum bundle were found to be associated with executive functioning and divided attention in patients with major depression. Disconnection within the limbic-cortical networks may underlay cognitive dysfunction in major depression. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  12. The button effect of CANFLEX bundle on the critical heat flux and critical channel power

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joo Hwan; Jun, Jisu; Suk, Ho Chun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Dimmick, G. R.; Bullock, D. E.; Inch, W. [Atomic Energy of Canada Limited, Ontario (Canada)

    1997-12-31

    A CANFLEX (CANdu FLEXible fuelling) 43-element bundle has developed for a CANDU-6 reactor as an alternative of 37-element fuel bundle. The design has two diameter elements (11.5 and 13.5 mm) to reduce maximum element power rating and buttons to enhance the critical heat flux (CHF), compared with the standard 37-element bundle. The freon CHF experiments have performed for two series of CANFLEX bundles with and without buttons with a modelling fluid as refrigerant R-134a and axial uniform heat flux condition. Evaluating the effects of buttons of CANFLEX bundle on CHF and Critical Channel Power (CCP) with the experimental results, it is shown that the buttons enhance CCP as well as CHF. All the CHF`s for both the CANFLEX bundles are occurred at the end of fuel channel with the high dryout quality conditions. The CHF enhancement ratio are increased with increase of dryout quality for all flow conditions and also with increase of mass flux only for high pressure conditions. It indicates that the button is a useful design for CANDU operating condition because most CHF flow conditions for CANDU fuel bundle are ranged to high dryout quality conditions. 5 refs., 11 figs. (Author)

  13. Food bundling as a health nudge: Investigating consumer fruit and vegetable selection using behavioral economics.

    Science.gov (United States)

    Carroll, Kathryn A; Samek, Anya; Zepeda, Lydia

    2018-02-01

    Displaying bundles of healthy foods at the grocery store is a health nudge that simplifies shopping and may have the potential for increasing fruit and vegetable (F&V) purchasing. To evaluate the impact of food bundling, we conduct an artefactual field experiment with community participants in a laboratory set up as a grocery store. Dual-self theory suggests that food choices may differ depending on whether shoppers are under cognitive load - in our experiment, we exogenously vary whether bundles are displayed (with and without a price discount) and whether shoppers are under cognitive load. Our findings align with prior studies that suggest unhealthy options are more likely to be selected when cognitive resources are constrained. When bundles are displayed, we observe increased F&V purchasing. We also observe a significant interaction between cognitive load and price discounting. We find discounted bundles are more effective in the absence of cognitive load, but non-discounted bundles are more effective when shoppers are under cognitive load. Although more research is warranted, our findings suggest that when shopping under cognitive load, it is possible that discounts impose additional cognitive strain on the shopping experience. For retailers and policymakers, our results point to the potential power of bundling as a strategy for increasing healthy food purchasing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Cysteine-rich protein 1 (CRP1 regulates actin filament bundling

    Directory of Open Access Journals (Sweden)

    Fraley Tamara S

    2005-12-01

    Full Text Available Abstract Background Cysteine-rich protein 1 (CRP1 is a LIM domain containing protein localized to the nucleus and the actin cytoskeleton. CRP1 has been demonstrated to bind the actin-bundling protein α-actinin and proposed to modulate the actin cytoskeleton; however, specific regulatory mechanisms have not been identified. Results CRP1 expression increased actin bundling in rat embryonic fibroblasts. Although CRP1 did not affect the bundling activity of α-actinin, CRP1 was found to stabilize the interaction of α-actinin with actin bundles and to directly bundle actin microfilaments. Using confocal and photobleaching fluorescence resonance energy transfer (FRET microscopy, we demonstrate that there are two populations of CRP1 localized along actin stress fibers, one associated through interaction with α-actinin and one that appears to bind the actin filaments directly. Consistent with a role in regulating actin filament cross-linking, CRP1 also localized to the membrane ruffles of spreading and PDGF treated fibroblasts. Conclusion CRP1 regulates actin filament bundling by directly cross-linking actin filaments and stabilizing the interaction of α-actinin with actin filament bundles.

  15. A contribution to understanding the structure of amphivasal secondary bundles in monocotyledons

    Directory of Open Access Journals (Sweden)

    Joanna Jura-Morawiec

    2014-04-01

    Full Text Available Secondary growth of monocotyledonous plants is connected with the activity of the monocot cambium that accumulates most of the derivatives inner to the cambial cylinder. These derivatives differentiate into (a secondary bundles with the amphivasal arrangement, i.e. xylem composed of tracheids surrounds the phloem cells and (b the parenchymatous secondary conjunctive tissue in which the bundles are embedded. The amphivasal secondary bundles differ in the arrangement of xylem cells as visible on single cross sections through the secondary body of the monocots. Apart from the bundles with typical ring of tracheids also the bundles where tracheids do not quite surround the phloem are present. We aimed to elucidate the cross sectional anatomy of the amphivasal secondary bundles with the use of the serial sectioning method which allowed us to follow very precisely the bundle structure along its length. The studies were carried out with the samples of secondary tissues collected from the stem of Dracaena draco L. growing in the greenhouses of the Polish Academy of Sciences Botanical Garden – CBDC in Powsin and the Adam Mickiewicz University Botanical Garden. The material was fixed in a mixture of glycerol and ethanol (1:1; v/v, dehydrated stepwise with graded ethanol series and finally embedded in epon resin. Afterwards, the material was sectioned with microtome into continuous series of thin (3 μm sections, stained with PAS/toluidine blue and examined under the light microscope. The results, described in details in Jura‑Morawiec & Wiland-Szymańska (2014, revealed novel facts about tracheids arrangement. Each amphivasal bundle is composed of sectors where tracheids form a ring as well as of such where tracheids are separated by vascular parenchyma cells. We hypothesize that strands of vascular parenchyma cells locally separating the tracheids enable radial transport of assimilates from sieve elements of the bundle towards the sink tissues, e

  16. Magnetic resonance imaging of double-bundle anterior cruciate ligament reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Poellinger, Alexander; Hamm, Bernd; Asbach, Patrick [Charite, Department of Radiology, Berlin (Germany); Scheffler, Sven [Charite, Department for Orthopaedic Surgery and Traumatology, Center for Musculoskeletal Surgery, Berlin (Germany)

    2009-04-15

    Reconstruction of the anterior cruciate ligament (ACL) using the double-bundle technique is getting highly increasing attention. This surgical approach uses two separate tendon grafts with the intention to reconstruct both anatomic bundles in order to restore the full biomechanical function of the original ligament. With the increasing popularity of this technique, radiologists will be more frequently confronted with patients who underwent this surgical procedure. The aims of this essay are to briefly describe the basic biomechanical and surgical principles and to summarize the magnetic resonance imaging findings of the knee after double-bundle ACL reconstruction. (orig.)

  17. Two-phase pressure drops for CANDU fuel bundles in uncrept and crept channels

    Energy Technology Data Exchange (ETDEWEB)

    Sutradhar, S.C. [Atomic Energy of Canada Ltd., Chalk River, Ontario (Canada)

    2001-07-01

    Pressure-drop tests in Freon-134a were performed on aligned and misaligned 37-element CANDU (C6) fuel bundles in uncrept and 3% crept channels. The results indicate that the two-phase pressure-drop profiles are similar in shape, but higher in magnitude, compared with the single-phase pressure-drop profiles. The two-phase multipliers (TPMs) are a strong function of the thermodynamic quality of the fluid. The measured TPMs of the bundles in the uncrept channel are higher than those in the crept channel. The measured TPMs for the aligned bundles agree well with the Beattie correlation. (author)

  18. Parabolic Higgs bundles and Teichmüller spaces for punctured surfaces

    CERN Document Server

    Biswas, I; Govindarajan, S; Biswas, Indranil; Gastesi, Pablo; Govindarajan, Suresh

    1995-01-01

    In this paper we study the relation between parabolic Higgs bundles and irreducible representations of the fundamental group of punctured Riemann surfaces established by Simpson. We generalize a result of Hitchin, identifying those parabolic Higgs bundles that correspond to Fuchsian representations. We also study the Higgs bundles that give representations whose image is contained, after conjugation, in SL(k,\\Bbb R). We compute the real dimension of one of the components of this space of representations, which in the absence of punctures is the generalized Teichm\\"uller space introduced by Hitchin, and which in the case of k=2 is the Teichm\\"uller space of the Riemann surface.

  19. Structural Studies of Amphiphilic 4-Helix Bundle Peptides Incorporating Designed Extended Chromophores for Nonlinear Optical Biomolecular Materials

    Energy Technology Data Exchange (ETDEWEB)

    Strzalka,J.; Xu, T.; Tronin, A.; Wu, S.; Miloradovic, I.; Kuzmenko, I.; Gog, T.; Therien, M.; Blasie, K.

    2006-01-01

    Extended conjugated chromophores containing (porphinato)zinc components that exhibit large optical polarizabilities and hyperpolarizabiliites are incorporated into amphiphilic 4-helix bundle peptides via specific axial histidyl ligation of the metal. The bundle's designed amphiphilicity enables vectorial orientation of the chromophore/peptide complex in macroscopic monolayer ensembles. The 4-helix bundle structure is maintained upon incorporation of two different chromophores at stoichiometries of 1-2 per bundle. The axial ligation site appears to effectively control the position of the chromophore along the length of the bundle.

  20. Transient filament stretching rheometer II

    DEFF Research Database (Denmark)

    Kolte, Mette Irene; Rasmussen, Henrik K.; Hassager, Ole

    1997-01-01

    The Lagrangian sspecification is used to simulate the transient stretching filament rheometer. Simulations are performed for dilute PIB-solutions modeled as a four mode Oldroyd-B fluid and a semidilute PIB-solution modeled as a non-linear single integral equation. The simulations are compared...

  1. Structural changes in the vascular bundles of light-exposed and shaded spruce needles suffering from Mg deficiency and ozone pollution.

    Science.gov (United States)

    Boxler-Baldoma, Carmen; Lütz, Cornelius; Heumann, Hans-Günther; Siefermann-Harms, Dorothea

    2006-02-01

    The correlation between structural changes of the vascular bundles and needle yellowing was examined for needles of damaged spruce (Picea abies (L.) Karst.) growing at a Mg-deficient and ozone polluted mountain site in the Central Black Forest (840m a.s.l.). In the previous year's sun-exposed needles, the following sequence of events was observed: (1) rapid needle yellowing, (2) hypertrophy and anomalous divisions of cambium cells, (3) phloem collapse, and, (4) production of atypical xylem tracheids. Under defined shade (reduction of the photosynthetically active photon flux density of the ambient light by 85-90%), the needles remained green, while the phloem collapsed completely within the first 6 weeks of shading; subsequently, a reversal of the collapse was observed. Under both light conditions, the content of Mg not bound to chlorophyll (Mg(free)) was in the range of 0.1 mg g(-1) needle dry matter, and hardly changed throughout the investigation period. After Mg fertilization, the Mg(free) level of the previous year's needles increased to 0.2 mg g(-1) dry matter, the light-exposed needles remained green, and the vascular bundles developed no anomalies. The data show that the rapid needle yellowing of ozone-exposed Mg-deficient needles did not depend on the collapse of the phloem. Mg deficiency played a key role in the development of anomalous vascular bundles under light, and also appears to explain the transient changes in sieve cell structure under shade. The role of Mg deficiency, rather than ozone pollution, in the damage of the sieve cells was confirmed in a long-term ozone exposure experiment with young clonal spruce growing under defined conditions.

  2. Turbulence Model Evaluation Study for a Secondary Flow and a Flow Pulsation in the Sub-Channels of an 18-Finned Rod Bundle by Using Computational Fluid Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Hark; Chae, Hee Taek; Park, Cheol; Kim, Heon Il

    2008-09-15

    Since the heat flux of the rod type fuel used in the HANARO, a research reactor being operated in the KAERI, is substantially higher than the heat flux of power reactors, the HANARO fuel has 8 longitudinal fins for enhancing the heat release from the fuel rod surface. This unique shape of a nuclear fuel led us to study the flows and thermal hydraulic characteristics of it. Especially because the flows through the narrow channels built up by these finned rod fuels would be different from the flow characteristics in the coolant channels formed by bare rod fuels, some experimental studies to investigate the flow behaviors and structures in a finned rod bundle were done by other researchers. But because of the very complex geometries of the flow channels in the finned rod bundle only allowed us to obtain limited information about the flow characteristics, a numerical study by a computational fluid dynamics technique has been adopted to elucidate more about such a complicated flow in a finned rod bundle. In this study, for the development of an adequate computational model to simulate such a complex geometry, a mesh sensitivity study and the effects of various turbulence models were examined. The CFD analysis results were compared with the experimental results. Some of them have a good agreement with the experimental results. All linear eddy viscosity turbulence models could hardly predict the secondary flows near the fuel surfaces and in the sub-channel, but the RSM (Reynolds Stress Model) revealed very different results from the eddy viscosity turbulence models. In the transient analysis all turbulence model predicted flow pulsation at the center of a subchannel as well as at the gap between rods in spite of large P/D. The flow pulsation showed different results with turbulence models and the location in the sub-channels.

  3. Plasticity in bundle sheath extensions of heterobaric leaves.

    Science.gov (United States)

    Lynch, Douglas J; McInerney, Francesca A; Kouwenberg, Lenny L R; Gonzalez-Meler, Miquel A

    2012-07-01

    Leaf venation is linked to physiological performance, playing a critical role in ecosystem function. Despite the importance of leaf venation, associated bundle sheath extensions (BSEs) remain largely unstudied. Here, we quantify plasticity in the spacing of BSEs over irradiance and precipitation gradients. Because physiological function(s) of BSEs remain uncertain, we additionally explored a link between BSEs and water use efficiency (WUE). We sampled leaves of heterobaric trees along intracrown irradiance gradients in natural environments and growth chambers and correlated BSE spacing to incident irradiance. Additionally, we sampled leaves along a precipitation gradient and correlated BSE spacing to precipitation and bulk δ(13)C, a proxy for intrinsic WUE. BSE spacing was quantified using a novel semiautomatic method on fresh leaf tissue. With increased irradiance or decreased precipitation, Liquidambar styraciflua decreased BSE spacing, while Acer saccharum showed little variation in BSE spacing. Two additional species, Quercus robur and Platanus occidentalis, decreased BSE spacing with increased irradiance in growth chambers. BSE spacing correlated with bulk δ(13)C, a proxy for WUE in L. styraciflua, Q. robur, and P. occidentalis leaves but not in leaves of A. saccharum. We demonstrated that BSE spacing is plastic with respect to irradiance or precipitation and independent from veins, indicating BSE involvement in leaf adaptation to a microenvironment. Plasticity in BSE spacing was correlated with WUE only in some species, not supporting a function in water relations. We discuss a possible link between BSE plasticity and life history, particularly canopy position.

  4. Bundled-Optode Method in Functional Near-Infrared Spectroscopy.

    Directory of Open Access Journals (Sweden)

    Hoang-Dung Nguyen

    Full Text Available In this paper, a theory for detection of the absolute concentrations of oxy-hemoglobin (HbO and deoxy-hemoglobin (HbR from hemodynamic responses using a bundled-optode configuration in functional near-infrared spectroscopy (fNIRS is proposed. The proposed method is then applied to the identification of two fingers (i.e., little and thumb during their flexion and extension. This experiment involves a continuous-wave-type dual-wavelength (760 and 830 nm fNIRS and five healthy male subjects. The active brain locations of two finger movements are identified based on the analysis of the t- and p-values of the averaged HbOs, which are quite distinctive. Our experimental results, furthermore, revealed that the hemodynamic responses of two-finger movements are different: The mean, peak, and time-to-peak of little finger movements are higher than those of thumb movements. It is noteworthy that the developed method can be extended to 3-dimensional fNIRS imaging.

  5. RBA: Reduced Bundle Adjustment for oblique aerial photogrammetry

    Science.gov (United States)

    Sun, Yanbiao; Sun, Huabo; Yan, Lei; Fan, Shiyue; Chen, Rui

    2016-11-01

    This study proposes an efficient Bundle Adjustment (BA) model for oblique aerial photogrammetry to reduce the number of unknown parameters and the dimensions of a non-linear optimization problem. Instead of serving as independent exterior orientations, oblique camera poses are parameterized with nadir camera poses and constant relative poses between oblique and nadir cameras. New observation functions are created with image points as a function of the nadir pose and the relative pose parameters. With these observation functions, the problem of BA is defined as finding optimal unknown parameters by minimizing the total difference between estimated and observed image points. A Gauss-Newton optimization method is utilized to provide a solution for this least-square problem with a reduced normal equation, which plays a very critical role in the convergence and efficiency of BA. Compared with traditional BA methods, the number of unknown parameters and the dimension of the normal equations decrease, this approach dramatically reduces the computational complexity and memory cost especially for large-scale scenarios with a number of oblique images. Four synthetic datasets and a real dataset were used to check the validation and the accuracy of the proposed method. The accuracy of the proposed method is very close to that of the traditional BA method, but the efficiency can be significantly improved by the proposed method. For very large-scale scenarios, the proposed method can still address the limitation of memory and orientate all images captured by an oblique aerial multi-camera system.

  6. Brugada syndrome behind complete right bundle-branch block.

    Science.gov (United States)

    Aizawa, Yoshiyasu; Takatsuki, Seiji; Sano, Motoaki; Kimura, Takehiro; Nishiyama, Nobuhiro; Fukumoto, Kotaro; Tanimoto, Yoko; Tanimoto, Kojiro; Murata, Mitsushige; Komatsu, Takashi; Mitamura, Hideo; Ogawa, Satoshi; Funazaki, Toshikazu; Sato, Masahito; Aizawa, Yoshifusa; Fukuda, Keiichi

    2013-09-03

    The characteristic ECG of Brugada syndrome (BS) can be masked by complete right bundle-branch block (CRBBB) and exposed by resolution of the block or pharmacological or pacing maneuvers. The study consisted of 11 patients who had BS and CRBBB. BS was diagnosed before the development of CRBBB, on the resolution of CRBBB, or from new characteristic ST-segment changes that could be attributable to BS. Structural heart diseases were excluded, and coronary spasm was excluded on the basis of a provocation test at catheterization. In 7 patients, BS was diagnosed before the development of CRBBB. BS was diagnosed when CRBBB resolved spontaneously (n=1) or by right ventricular pacing (n=3). The precipitating cause for the spontaneous resolution of CRBBB, however, was not apparent. On repeated ECGs, new additional upward-convex ST-segment elevation was found in V2 or V3 in 3 patients. In 2 patients, new ST-segment elevation was induced by class IC drugs. The QRS duration was more prolonged in patients with BS and CRBBB compared with age- and sex-matched controls: 170±13 versus 145±15 milliseconds in V1 and 144±19 versus 128±7 milliseconds in V5 (both Pmask BS. BS might be demonstrated by relief of CRBBB or by spontaneous or drug-induced ST-segment elevation. The prevalence, mechanism, and clinical significance of a combination of CRBBB and BS are yet to be determined.

  7. Application and Performance Analysis of a New Bundle Adjustment Model

    Science.gov (United States)

    Sun, Y.; Liu, X.; Chen, R.; Wan, J.; Wang, Q.; Wang, H.; Li, Y.; Yan, L.

    2017-09-01

    As the basis for photogrammetry, Bundle Adjustment (BA) can restore the pose of cameras accurately, reconstruct the 3D models of environment, and serve as the criterion of digital production. For the classical nonlinear optimization of BA model based on the Euclidean coordinate, it suffers the problem of being seriously dependent on the initial values, making it unable to converge fast or converge to a global minimum. This paper first introduces a new BA model based on parallax angle feature parametrization, and then analyses the applications and performance of the model used in photogrammetry field. To discuss the impact and the performance of the model (especially in aerial photogrammetry), experiments using two aerial datasets under different initial values were conducted. The experiment results are better than some well-known software packages of BA, and the simulation results illustrate the stability of the new model than the normal BA under the Euclidean coordinate. In all, the new BA model shows promising applications in faster and more efficient aerial photogrammetry with good convergence and fast convergence speed.

  8. Group systems, groupoids, and moduli spaces of parabolic bundles

    CERN Document Server

    Guruprasad, K; Jeffrey, L; Weinstein, A

    1997-01-01

    Let $G$ be a Lie group, with an invariant non-degenerate symmetric bilinear form on its Lie algebra, let $\\pi$ be the fundamental group of an orientable (real) surface $M$ with a finite number of punctures, and let $\\bold C$ be a family of conjugacy classes in $G$, one for each puncture. A finite-dimensional construction used earlier to obtain a symplectic structure on the moduli space of flat $G$-bundles over compact $M$ is extended to the punctured case. It yields a symplectic structure on a certain smooth manifold $\\Cal M_{\\bold C}$ containing the space $\\roman{Hom}(\\pi,G)_{\\bold C}$ of homomorphisms mapping the generators corresponding to the punctures into the corresponding conjugacy classes. It also yields a Hamiltonian $G$-action on $\\Cal M_{\\bold C}$ such that the reduced space equals the moduli space $\\roman{Rep}(\\pi,G)_{\\bold C}$ of representations. For $G$ compact, each such space, obtained by finite-dimensional symplectic reduction, is a {\\it stratified symplectic space\\/}. For $G=U(n)$ one gets m...

  9. Turbulent transports by secondary flow vortices in a rod bundle

    Energy Technology Data Exchange (ETDEWEB)

    Vonka, V.

    1988-02-01

    Experimental data on secondary flow vortices in a rod bundle with pitch-to-diameter ratio P/D=1.3 show weak vortices with the average velocity magnitude only about 0.1% of the mean bulk velocity. The question then arises, how important these weak vortices could still be as a transport mechanism in turbulent flows. The transport of axial momentum by these vortices is analysed quantitatively. While a minor importance is observed for the transport in radial direction, it is found that about half of the total transport in circumferential direction is due to the secondary flow vortex convection. Based on the analogy between the transport of momentum and heat, it is expected in nonisothermal situations that, in radial direction, the contribution can improve the heat transfer coefficient and contribute to better economy of heat transfer installations. In circumferential direction, the contribution helps to smooth out circumferential temperature differences, improves the heat removal from heated surfaces and, through a decrease of the maximum surface temperature, it contributes to passive safety of heat transfer installations.

  10. Study of the spatial dependence of neutronic flow oscillations caused by fluctuations thermohydraulics at the entrance of the core of a reactor PWR; Estudio de la dependencia espacial de las oscilaciones de flujo neutronico causadas por flucturaciones termohidraulicas a la entrada del nucleo de un reactor PWR

    Energy Technology Data Exchange (ETDEWEB)

    Bermejo, J. A.; Lopez, A.; Ortego, A.

    2014-07-01

    It presents a theoretical study on spatial dependence of flow oscillations neutronic caused by thermal hydraulics fluctuations at the entrance of the core of a PWR reactor. To simulate, with SIMULATE code - 3K different fluctuations thermohydraulics at the entrance to the core and the spatial dependence of the oscillations and is analyzed neutronic flow obtained at locations of neutron detectors. the work It is part of the r and d program initiated in CNAT to investigate the phenomenon of the noise neutronic. (Author)

  11. The significance of dissociation of conduction in the canine His bundle. Electrophysiological studies in vivo and in vitro.

    Science.gov (United States)

    Scherlag, B J; El-Sherif, N; Hope, R R; Lazzara, R

    1978-10-01

    Fractionated His bundle potentials were induced by ischemia or trauma in 30 anesthetized dogs, in vivo. Functional dissociation, i.e., alteration of the activation sequence of portions of these His bundle potentials was demonstrated in vivo as well as in 10 in vitro preparations of the His-Purkinje system. In vivo, plunge wire and electrode catheters were utilized to record from portions of the His bundle. During vagal-induced slowing of the heart rate, atrial pacing or His bundle pacing, His-Purkinje conduction as measured by the H-V interval was constant over a wide range of heart rates, 50-300/min. One or two hours after anterior septal artery ligation, His bundle damage manifested as split His bundle potentials (H, H'). Atrial pacing or proximal His bundle pacing induced H-H' delays with concomitant right or left bundle branch block patterns in ECG leads. However, distal His bundle pacing at comparable or even higher rates produced normal QRS complexes. In other cases, during atrial pacing or with progressive ischemia at a constant rate, H' progressively delayed during the H-V interval or even disappeared into the QRS complex with a concomitant occurrence of right or left bundle branch block. In vitro, a dissected septal preparation was studied containing the His bundle, proximal and distal right bundle and left bundle branches. Normal conduction throughout the His-Purkinje system was observed at pacing rates of 30-220/min. Punctate lesions, anatomically placed above the branching His bundle caused tachycardia-dependent, complete bundle branch blocked with concurrent temporal reversal of proximal and distal His bundle action potentials. These data suggest that ischemic or traumatic lesions in the His bundle may manifest on the electrocardiogram as bundle branch block patterns. From a clinical point of view, a critical site of lesion would markedly increase the liability for A-V blocked although the electrocardiogram alone would not indicate the actual site of

  12. Adsorption behavior of ternary mixtures of noble gases inside single-walled carbon nanotube bundles

    Science.gov (United States)

    Foroutan, Masumeh; Nasrabadi, Amir Taghavi

    2010-09-01

    In order to study the gas-storage and gas-filtering capability of carbon nanotube (CNT) bundles simultaneously, we considered the adsorption behavior of a ternary mixture of noble gases, including Argon (Ar), Krypton (Kr), and Xenon (Xe), i.e., Ar-Kr-Xe mixture, on (10, 10) single-walled carbon nanotube (SWCNT) bundles. Molecular dynamics (MD) simulations at different temperatures of (75, 100, 150, 200, 250, and 300) K were performed, and adsorption energies, self-diffusion coefficients, activation energies, and radial distribution functions (RDFs) were computed to analyze the thermodynamics, transport and structural properties of the adsorption systems. It is observed that the SWCNT bundles have larger contents of heavier noble gases compared to the lighter ones. This interesting behavior of SWCNT bundles makes them proper candidates for gas-storage and gas molecular-sieving processes.

  13. The design of self-collapsed super-strong nanotube bundles

    Science.gov (United States)

    Pugno, Nicola Maria

    2010-09-01

    The study reported in this paper suggests that the influence of the surrounding nanotubes in a bundle is nearly identical to that of a liquid having surface tension equal to the surface energy of the nanotubes. This surprising behaviour is supported by the calculation of the polygonization and especially of the self-collapse diameters, and related dog-bone configurations, of nanotubes in a bundle, in agreement with atomistic simulations and nanoscale experiments. Accordingly, we have evaluated the strength of the nanotube bundle, with or without collapsed nanotubes, assuming a sliding failure: the self-collapse can increase the strength up to a value of about ˜30%, suggesting the design of self-collapsed super-strong nanotube bundles. Other systems, such as peapods and fullerites, can be similarly treated, including the effect of the presence of a liquid, as reported in the appendices.

  14. Integrated Care Pathways and Care Bundles for Dementia in Acute Care: Concept Versus Evidence.

    Science.gov (United States)

    Sullivan, Dawn O; Mannix, Mary; Timmons, Suzanne

    2017-06-01

    Caring for people with dementia in acute settings is challenging and confounded by multiple comorbidities and difficulties transitioning between community and acute care. Recently, there has been an increase in the development and use of integrated care pathways (ICPs) and care bundles for defined illnesses and medical procedures, and these are now being promoted for use in dementia care in acute settings. We present a review of the literature on ICPs and/or care bundles for dementia care in the acute sector. This includes a literature overview including "gray literature" such as relevant websites, reports, and government publications. Taken together, there is clearly a growing interest in and clinical use of ICPs and care bundles for dementia. However, there is currently insufficient evidence to support the effectiveness of ICPs for dementia care in acute settings and limited evidence for care bundles for dementia in this setting.

  15. On the Quality and Efficiency of Approximate Solutions to Bundle Adjustment with Epipolar and Trifocal Constraints

    Science.gov (United States)

    Schneider, J.; Stachniss, C.; Förstner, W.

    2017-08-01

    Bundle adjustment is a central part of most visual SLAM and Structure from Motion systems and thus a relevant component of UAVs equipped with cameras. This paper makes two contributions to bundle adjustment. First, we present a novel approach which exploits trifocal constraints, i.e., constraints resulting from corresponding points observed in three camera images, which allows to estimate the camera pose parameters without 3D point estimation. Second, we analyze the quality loss compared to the optimal bundle adjustment solution when applying different types of approximations to the constrained optimization problem to increase efficiency. We implemented and thoroughly evaluated our approach using a UAV performing mapping tasks in outdoor environments. Our results indicate that the complexity of the constraint bundle adjustment can be decreased without loosing too much accuracy.

  16. Implementation of a children's hospital-wide central venous catheter insertion and maintenance bundle

    NARCIS (Netherlands)

    K. Helder MScN (Onno); R.F. Kornelisse (René); C. van der Starre (Cynthia); D. Tibboel (Dick); C.W.N. Looman (Caspar); R.M.H. Wijnen (René); M.J. Poley (Marten); E. Ista (Erwin)

    2013-01-01

    textabstractBackground: Central venous catheter-associated bloodstream infections in children are an increasingly recognized serious safety problem worldwide, but are often preventable. Central venous catheter bundles have proved effective to prevent such infections. Successful implementation

  17. Single- and Two-Phase Turbulent Mixing Rate between Subchannels in Triangle Tight Lattice Rod Bundle

    National Research Council Canada - National Science Library

    KAWAHARA, Akimaro; SADATOMI, Michio; KUDO, Hiroyuki; KANO, Keiko

    2006-01-01

    In order to obtain the data on turbulent mixing rate between triangle tight lattice subchannels, which will be adopted as the next generation BWR fuel rod bundle, adiabatic experiments were conducted...

  18. Dynamically Switching among Bundled and Single Tickets with Time-Dependent Demand Rates

    Directory of Open Access Journals (Sweden)

    Serhan Duran

    2012-01-01

    Full Text Available The most important market segmentation in sports and entertainment industry is the competition between customers that buy bundled and single tickets. A common selling practice is starting the selling season with bundled ticket sales and switching to selling single tickets later on. The aim of this practice is to increase the number of customers that buy bundles, which in return increases the load factor of the events with low demand. In this paper, we investigate the effect of time dependent demand on dynamic switching times from bundled to single ticket sales and the potential revenue gain over the case where the demand rate of events is assumed to be constant with time.

  19. Right bundle branch block and anterior wall ST elevation myocardial infarction.

    Science.gov (United States)

    Trofin, Monica; Israel, Carsten W; Barold, S Serge

    2017-09-01

    We report the case of an acute anterior wall ST elevation myocardial infarction with new left anterior fascicular block and pre-existing right bundle branch block. Due to a wide right bundle branch block, no ST segment elevation was visible in lead V1. The left anterior fascicular block was caused by proximal occlusion of the left artery descending and disappeared after acute revascularization. However, also the R' of the right bundle branch block became significantly shorter after revascularization, dismanteling a minor ST segment elevation. The ST elevation in lead V1 in anterior wall infarction and right bundle branch block may merge with the R' and cause a further QRS widening as an "equivalent" to the ST elevation.

  20. GPS-supported Bundle Adjustment Method of UAV by Considering Exposure Delay

    Directory of Open Access Journals (Sweden)

    ZHANG Chunsen

    2017-05-01

    Full Text Available The existing GPS-supported bundle adjustment method does not take into account the influence of camera exposure delay error impact in UAV photogrammetry is inconsistent which leading to the actual adjustment results are worse than the theoretical results. The mechanism of exposure delay is studied. The impact of exposure delay on GPS-supported bundle adjustment is analyzed. And a GPS-supported bundle adjustment method by considering the exposure delay is proposed. The effectiveness of the proposed method is verified by a typical dataset of 142 images. The meaning of the proposed method is that it can achieve the better aero-triangulation accuracy than the traditional GPS-supported bundle adjustment method.

  1. Energy Band Gap Study of Semiconducting Single Walled Carbon Nanotube Bundle

    Science.gov (United States)

    Elkadi, Asmaa; Decrossas, Emmanuel; El-Ghazaly, Samir

    2013-01-01

    The electronic properties of multiple semiconducting single walled carbon nanotubes (s-SWCNTs) considering various distribution inside a bundle are studied. The model derived from the proposed analytical potential function of electron density for na individual s-SWCNT is general and can be easily applied to multiple nanotubes. This work demonstrates that regardless the number of carbon nanotubes, the strong coupling occurring between the closet neighbors reduces the energy band gap of the bundle by 10%. As expected, the coupling is strongly dependent on the distance separating the s-SWCNTs. In addition, based on the developed model, it is proposed to enhance this coupling effect by applying an electric field across the bundle to significantly reduce the energy band gap of the bundle by 20%.

  2. Acute myocardial infarction and left bundle branch block with changing axis deviation.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Dattilo, Giuseppe; Sturiale, Mauro

    2012-02-09

    Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Left bundle branch block is usually associated with normal or left axis deviation. Rarely the ECG shows a LBBB with changing QRS morphology and changing axis deviation. There are several possible explanations for the intermittent shift in the QRS axis in the presence of complete left bundle branch block. The most plausible explanation is the coexistence of left posterior hemiblock and predivisional left bundle branch block. We present a case of a left bundle branch block with changing axis deviation in a 93-year-old Italian woman admitted to the Cardiology Unit with an acute myocardial infarction. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  3. Left bundle branch block and changing axis deviation during acute myocardial infarction.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo; Sturiale, Mauro

    2012-03-22

    Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Left bundle branch block is usually associated with normal or left axis deviation. Rarely the ECG shows a left bundle branch block with changing QRS morphology and changing axis deviation. We present a case of a left bundle branch block with changing axis deviation in an 86-year-old Italian man admitted to the Cardiology Unit with an acute myocardial infarction. Also this case focuses attention on left bundle branch block with changing axis deviation. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  4. Myosin III-mediated cross-linking and stimulation of actin bundling activity of Espin

    National Research Council Canada - National Science Library

    Liu, Haiyang; Li, Jianchao; Raval, Manmeet H; Yao, Ningning; Deng, Xiaoying; Lu, Qing; Nie, Si; Feng, Wei; Wan, Jun; Yengo, Christopher M; Liu, Wei; Zhang, Mingjie

    2016-01-01

    Class III myosins (Myo3) and actin-bundling protein Espin play critical roles in regulating the development and maintenance of stereocilia in vertebrate hair cells, and their defects cause hereditary hearing impairments...

  5. Bundling Post-Acute Care Services into MS-DRG Payments

    Data.gov (United States)

    U.S. Department of Health & Human Services — A bundled hospital payment system that encompasses both acute and post-acute care has been proposed as a means of creating financial incentives in the Medicare...

  6. Impact of VAP bundle adherence among ventilated critically ill patients and its effectiveness in adult ICU

    Directory of Open Access Journals (Sweden)

    Saad Rabie Samra

    2017-01-01

    Conclusion: The application of VAP bundle is a feasible reality that produces improvement in microbiological measures and nosocomal infection rates resulting in lowering mortality, shortened lengths of hospitalization and decreased medical care costs. However, education and periodic training remain a fundamental process of improving health services. VAPs were reduced by improving bundle compliance and ensuring the same standard of care to all ICU patients. Direct, on-site observation was a more accurate method of monitoring.

  7. An Exploration of Human Well-Being Bundles as Identifiers of Ecosystem Service Use Patterns.

    Directory of Open Access Journals (Sweden)

    Maike Hamann

    Full Text Available We take a social-ecological systems perspective to investigate the linkages between ecosystem services and human well-being in South Africa. A recent paper identified different types of social-ecological systems in the country, based on distinct bundles of ecosystem service use. These system types were found to represent increasingly weak direct feedbacks between nature and people, from rural "green-loop" communities to urban "red-loop" societies. Here we construct human well-being bundles and explore whether the well-being bundles can be used to identify the same social-ecological system types that were identified using bundles of ecosystem service use. Based on national census data, we found three distinct well-being bundle types that are mainly characterized by differences in income, unemployment and property ownership. The distribution of these well-being bundles approximates the distribution of ecosystem service use bundles to a substantial degree: High levels of income and education generally coincided with areas characterised by low levels of direct ecosystem service use (or red-loop systems, while the majority of low well-being areas coincided with medium and high levels of direct ecosystem service use (or transition and green-loop systems. However, our results indicate that transformations from green-loop to red-loop systems do not always entail an immediate improvement in well-being, which we suggest may be due to a time lag between changes in the different system components. Using human well-being bundles as an indicator of social-ecological dynamics may be useful in other contexts since it is based on socio-economic data commonly collected by governments, and provides important insights into the connections between ecosystem services and human well-being at policy-relevant sub-national scales.

  8. Permanent His Bundle Pacing in Intra-Hisian Conduction Block: Mechanistic Insights.

    Science.gov (United States)

    Herweg, Bengt; Gerczuk, Paul Z; Sofi, Aamir; Vijayaraman, Pugazhendhi; Barold, S Serge

    2017-06-09

    We are reporting a patient with discrete intra-His conduction block and describe a refined technique of permanent His bundle pacing assuring reliable ventricular capture. Meticulous mapping of the site of block with lead placement distal to the site of block and non-selective His bundle pacing with local myocardial capture as an additional safety back up appears to be the technique of choice. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Fighting Capital Flight in Africa: Evidence from Bundling and Unbundling Governance

    OpenAIRE

    Asongu, Simplice; Nwachukwu, Jacinta

    2016-01-01

    This study investigates the effect of governance on capital flight by bundling and unbundling governance. The empirical evidence is based on 37 African countries for the period 1996-2010 and the Generalised Method of Moments. Governance is bundled by principal component analysis, namely: (i) political governance from political stability and ‘voice and accountability’; (ii) economic governance from government effectiveness and regulation quality and (iii) institutional governance from corrupti...

  10. Time evolution of damage due to environmentally assisted aging in a fiber bundle model

    OpenAIRE

    Lennartz-Sassinek, Sabine; Main, Ian G.; Danku Zsuzsa (1984-) (fizikus); Kun Ferenc (1966-) (fizikus)

    2013-01-01

    Damage growth in composite materials is a complex process which is of interest in many fields of science and engineering. We consider this problem in a fiber bundle model where fibers undergo an aging process due to the accumulation of damage driven by the locally acting stress in a chemically active environment. By subjecting the bundle to a constant external load, fibers fail either when the load on them exceeds their individual intrinsic strength or when the accumulated internal damage exc...

  11. Model for subchannel friction factors and flow redistribution in wire-wrapped rod bundles

    OpenAIRE

    Carajilescov, Pedro; Fernandez y Fernandez, Elói

    1999-01-01

    The fuel element of LMFBR consists of a bundle of rods wrapped with an helical wire as spacer, surrounded by an hexagonal duct. In the present work, a semi-empirical model is developed to calculate bundle average and subchannel based friction factors and flow redistribution. The obtained results were compared to experimental data and they were considered satisfactory for wide range of geometrical parameters.

  12. Rate-Dependent Left Bundle-Branch Block in a Child With Propionic Aciduria

    Science.gov (United States)

    Ardoin, Kipp B.; Moodie, Douglas S.; Snyder, Christopher S.

    2009-01-01

    In most cases, a left bundle-branch block pattern on an electrocardiogram is a postoperative phenomenon. Under rare circumstances, it can be found in patients after myocardial infarction or in patients with hypertrophic cardiomyopathy, or it can be exercised induced. We describe a pediatric patient with propionic aciduria, dilated cardiomyopathy, and rate-dependent left bundle-branch block on her electrocardiogram. PMID:21603417

  13. Right bundle branch block pattern in right ventricular endocardial pacing: A needless concern?

    Directory of Open Access Journals (Sweden)

    Mangalachulli Pottammal Ranjith

    2013-01-01

    Full Text Available Right ventricular (RV endocardial pacing in permanent pacemaker implantation usually yields a left bundle branch block (LBBB pattern in surface electrocardiogram (ECG. The presence of right bundle branch block (RBBB pattern raises the suspicion of lead perforation. We report a case of RV endocardial permanent pacemaker implantation showing a RBBB pattern in ECG, suggesting a complication. However, further work-up revealed that the lead was appropriately located at the RV apex.

  14. Force Generation by Molecular-Motor-Powered Microtubule Bundles; Implications for Neuronal Polarization and Growth.

    Science.gov (United States)

    Jakobs, Maximilian; Franze, Kristian; Zemel, Assaf

    2015-01-01

    The heavily cross-linked microtubule (MT) bundles found in neuronal processes play a central role in the initiation, growth and maturation of axons and dendrites; however, a quantitative understanding of their mechanical function is still lacking. We here developed computer simulations to investigate the dynamics of force generation in 1D bundles of MTs that are cross-linked and powered by molecular motors. The motion of filaments and the forces they exert are investigated as a function of the motor type (unipolar or bipolar), MT density and length, applied load, and motor connectivity. We demonstrate that only unipolar motors (e.g., kinesin-1) can provide the driving force for bundle expansion, while bipolar motors (e.g., kinesin-5) oppose it. The force generation capacity of the bundles is shown to depend sharply on the fraction of unipolar motors due to a percolation transition that must occur in the bundle. Scaling laws between bundle length, force, MT length and motor fraction are presented. In addition, we investigate the dynamics of growth in the presence of a constant influx of MTs. Beyond a short equilibration period, the bundles grow linearly in time. In this growth regime, the bundle extends as one mass forward with most filaments sliding with the growth velocity. The growth velocity is shown to be dictated by the inward flux of MTs, to inversely scale with the load and to be independent of the free velocity of the motors. These findings provide important molecular-level insights into the mechanical function of the MT cytoskeleton in normal axon growth and regeneration after injury.

  15. The Effects of Resource Bundling on Third-party Logistics Providers’ Performance

    OpenAIRE

    Noorliza Karia; Chee Yew Wong; Muhammad Hasmi Abu Hassan Asaari; Kee-hung Lai

    2015-01-01

    This research develops and tests a model of the effects of resources bundling on third-party logistics (3PL) providers’ performance. Based on data from a survey of Malaysian 3PLs, basic and advanced technology and equipment resources, knowledge and relational resources, and demand management interfaces are identified. The bundling of advanced technology, knowledge resources, and demand management interface capability are found to enhance 3PLs’ customer service innovation. Similar resource ...

  16. Fluid mixing studies in a hexagonal 61-pin, wire-wrapped rod bundle

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, A S; Todreas, N

    1977-08-01

    Two wire-wrapped rod bundles with different leads (6 in. and 12 in.) were constructed with geometric parameters similar to proposed LMFBR fuel assemblies. Rod diameter was 0.25 in. and pitch-to-diameter ratio was 1.26. These two bundles were tested in a flow loop which was designed and built for mixing experiments. Fluid mixing was studied by means of salt tracer dispersion. Salt was injected at various radial and axial locations in the bundle via injection rods, and then the dispersed distribution was measured at the bundle exit by means of 126 specially designed electrical conductivity probes inserted into the bundle subchannels. The data collected showed a strong swirl flow around the bundle circumference and periodic variation with axial injection location. Data from turbulent runs was generally good with mass balances averaging 90% and having a spread of +- 25%. The laminar data collected was generally poor because of a ''striping'' phenomena and injection instabilities. Data were compared with calculations using the ENERGY computer code. The comparison between ENERGY calculations and the data was not good for laminar flow and was only fair in the turbulent cases. It was found that turbulent data could be best characterized by the ENERGY parameters C/sub 1/ = 0.19 and epsilon/sub 1/* = 0.025 when the lead was 6 inches; for a 12-inch lead the parameters were C/sub 1/ = 0.16 and epsilon/sub 1/* = 0.012. Pressure drop data was also taken from the two bundles and it too showed a periodic variation with axial location. Friction factors derived from the data were generally higher than predicted by available correlations. These data suggested that traditional flow split calculations could be in error and that the laminar-turbulent transition occurs over a broad Reynolds number range in wire-wrapped rod bundles.

  17. 10D massive type IIA supergravities as the uplift of parabolic M2-brane torus bundles

    Energy Technology Data Exchange (ETDEWEB)

    Garcia del Moral, Maria Pilar [Universidad de Antofagasta (Chile). Dept. de Fisica; Restuccia, Alvaro [Universidad de Antofagasta (Chile). Dept. de Fisica; Universidad Simon Bolivar, Caracas (Venezuela, Bolivarian Republic of). Dept. de Fisica

    2016-04-15

    We remark that the two 10D massive deformations of the N = 2 maximal type IIA supergravity (Romans and HLW supergravity) are associated to the low energy limit of the uplift to 10D of M2-brane torus bundles with parabolic monodromy linearly and non-linearly realized respectively. Romans supergravity corresponds to M2-brane compactified on a twice-punctured torus bundle. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. The Intermediate Jacobian of a Three-Dimensional Conic Bundle is a Prym Variety

    Science.gov (United States)

    Èndryushka, S. Yu

    1985-02-01

    The paper contains the computation of the intermediate Jacobian of the general conic bundle. This computation is performed in three steps: a) computation of the Betti number (§2), b) computation of the Jacobian to within isogeny (§4), and c) computation of the polarization (§4).The author's results conclude the study of the intermediate Jacobian of conic bundles and give an efficient general answer.Bibliography: 6 titles.

  19. Description of the attachment geometry of the anteromedial and posterolateral bundles of the ACL from arthroscopic perspective for anatomical tunnel placement.

    NARCIS (Netherlands)

    Luites, J.W.H.; Wymenga, A.B.; Blankevoort, L.; Kooloos, J.G.M.

    2007-01-01

    The anterior cruciate ligament (ACL) consists of an anteromedial bundle (AMB) and a posterolateral bundle (PLB). A reconstruction restoring the functional two-bundled nature should be able to approximate normal ACL function better than the most commonly used single-bundle reconstructions. Accurate

  20. Description of the attachment geometry of the anteromedial and posterolateral bundles of the ACL from arthroscopic perspective for anatomical tunnel placement

    NARCIS (Netherlands)

    Luites, Joan W. H.; Wymenga, Ate B.; Blankevoort, Leendert; Kooloos, Jan G. M.

    2007-01-01

    The anterior cruciate ligament (ACL) consists of an anteromedial bundle (AMB) and a posterolateral bundle (PLB). A reconstruction restoring the functional two-bundled nature should be able to approximate normal ACL function better than the most commonly used single-bundle reconstructions. Accurate

  1. Electron Transfer Activity of a de Novo Designed Copper Center in a Three-Helix Bundle Fold

    Science.gov (United States)

    Plegaria, Jefferson S.; Herrero, Christian; Quaranta, Annamaria; Pecoraro, Vincent L.

    2017-01-01

    In this work, we characterized the intermolecular ET property of a de novo designed metallopeptide using laser-flash photolysis. α3D-CH3 is three-helix bundle peptide that was designed to contain a copper ET site found in the β-barrel fold of native cupredoxins. The ET activity of Cuα3D-CH3 was determined using five different photosensitizers. By exhibiting a complete depletion of the photo-oxidant and the successive formation of a Cu(II) species at 400 nm, the transient and generated spectra demonstrated an ET transfer reaction between the photo-oxidant and Cu(I)α3D-CH3. This observation illustrated our success in integrating an ET center within a de novo designed scaffold. From the kinetic traces at 400 nm, first-order and bimolecular rate constants of 105 s−1 and 108 M−1 s−1 were derived. Moreover, a Marcus equation analysis on the rate versus driving force study produced a reorganization energy of 1.1 eV, demonstrating that the helical fold of α3D requires further structural optimization to efficiently perform ET. PMID:26427552

  2. Bundled payments for care improvement initiative: the next evolution of payment formulations: AAHKS Bundled Payment Task Force.

    Science.gov (United States)

    Froimson, Mark I; Rana, Adam; White, Richard E; Marshall, Amanda; Schutzer, Steve F; Healy, William L; Naas, Peggy; Daubert, Gail; Iorio, Richard; Parsley, Brian

    2013-09-01

    The Patient Protection and Affordable Care Act contains a number of provision for improving the delivery of healthcare in the United States, among the most impactful of which may be the call for modifications in the packaging of and payment for care that is bundled into episodes. The move away from fee for service payment models to payment for coordinated care delivered as comprehensive episodes is heralded as having great potential to enhance quality and reduce cost, thereby increasing the value of the care delivered. This effort builds on the prior experience around delivering care for arthroplasty under the Acute Care Episode Project and offers extensions and opportunities to modify the experience moving forward. Total hip and knee arthroplasties are viewed as ideal treatments to test the effectiveness of this payment model. Providers must learn the nuances of these modified care delivery concepts and evaluate whether their environment is conducive to success in this arena. This fundamental shift in payment for care offers both considerable risk and tremendous opportunity for physicians. Acquiring an understanding of the recent experience and the determinants of future success will best position orthopaedic surgeons to thrive in this new environment. Although this will remain a dynamic exercise for some time, early experience may enhance the chances for long term success, and physicians can rightfully lead the care delivery redesign process. © 2013 Elsevier Inc. All rights reserved.

  3. Cadherin-23 may be dynamic in hair bundles of the model sea anemone Nematostella vectensis.

    Directory of Open Access Journals (Sweden)

    Pei-Ciao Tang

    Full Text Available Cadherin 23 (CDH23, a component of tip links in hair cells of vertebrate animals, is essential to mechanotransduction by hair cells in the inner ear. A homolog of CDH23 occurs in hair bundles of sea anemones. Anemone hair bundles are located on the tentacles where they detect the swimming movements of nearby prey. The anemone CDH23 is predicted to be a large polypeptide featuring a short exoplasmic C-terminal domain that is unique to sea anemones. Experimentally masking this domain with antibodies or mimicking this domain with free peptide rapidly disrupts mechanotransduction and morphology of anemone hair bundles. The loss of normal morphology is accompanied, or followed by a decrease in F-actin in stereocilia of the hair bundles. These effects were observed at very low concentrations of the reagents, 0.1-10 nM, and within minutes of exposure. The results presented herein suggest that: (1 the interaction between CDH23 and molecular partners on stereocilia of hair bundles is dynamic and; (2 the interaction is crucial for normal mechanotransduction and morphology of hair bundles.

  4. Cardiac memory during rather than after termination of left bundle branch block.

    Science.gov (United States)

    Littmann, Laszlo; Proctor, Patrick A; Givens, Priscilla M

    2014-01-01

    An 83-year-old woman with chronic left bundle branch block and remote history of pacemaker implantation for intermittent AV block was hospitalized for fatigue and leg swelling. She had no cardiac complaints. Routine 12-lead electrocardiogram showed sinus rhythm with left bundle branch block. There were diffuse negative T waves in the inferior and anterolateral leads that were concordant with the QRS complexes. Echocardiogram was normal and nuclear perfusion heart scan showed no abnormality. It was noted that the negative T waves during left bundle branch block were in the exact same leads as were the deep negative QRS complexes during ventricular pacing. The electrocardiographic changes were consistent with cardiac memory. This case is unique because cardiac memory in patients with intermittent left bundle branch block typically occurs when the QRS complexes normalize and not during left bundle branch block itself. Our findings indicate that memory Ts can develop not only after normalization of wide complex rhythms but also with alternating wide complex rhythms as in the presented case where a ventricular paced rhythm was replaced by left bundle branch block. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. 10 years with slash bundles. More efficiency and flexibility to forest energy logistics

    Energy Technology Data Exchange (ETDEWEB)

    Kilponen, M. (John Deere Forestry Oy, Tampere (Finland)), e-mail: Kilponen.MaricaA@JohnDeere.com

    2010-07-01

    John Deere Forestry introduced its first slash bundler TJ1490D to the market in 2002. Bioenergy market was developing rapidly especially in Finland during the first two years, and bundling method was taken in use in several other European countries. Thereafter, bundler market has been growing constantly in the other countries, but in Finland the development of market has almost come to a stop without any visible change in operations or technology. This has raised interesting question: What are the main differences in the market areas and why are they developing differently? Aim to get better understanding of bundling related business and market differences, all current and former slash bundler customers in Finland and Spain have been interviewed. results of the study show interesting differences in business models, which also have direct relation to the overall profitability. Based on the results it's also obvious that the earlier learning period of using bundles still has a great impact in this method's reputation: moisture of bundles and cutting challenges of twine are still seen as a challenge, even though there are good examples of power plants who have learned how to use bundles in most efficient way. Using bundles as part of logistic solution in biomass supply chain can offer several benefits to the forest energy sector. (orig.)

  6. Cadherin-23 may be dynamic in hair bundles of the model sea anemone Nematostella vectensis.

    Science.gov (United States)

    Tang, Pei-Ciao; Watson, Glen M

    2014-01-01

    Cadherin 23 (CDH23), a component of tip links in hair cells of vertebrate animals, is essential to mechanotransduction by hair cells in the inner ear. A homolog of CDH23 occurs in hair bundles of sea anemones. Anemone hair bundles are located on the tentacles where they detect the swimming movements of nearby prey. The anemone CDH23 is predicted to be a large polypeptide featuring a short exoplasmic C-terminal domain that is unique to sea anemones. Experimentally masking this domain with antibodies or mimicking this domain with free peptide rapidly disrupts mechanotransduction and morphology of anemone hair bundles. The loss of normal morphology is accompanied, or followed by a decrease in F-actin in stereocilia of the hair bundles. These effects were observed at very low concentrations of the reagents, 0.1-10 nM, and within minutes of exposure. The results presented herein suggest that: (1) the interaction between CDH23 and molecular partners on stereocilia of hair bundles is dynamic and; (2) the interaction is crucial for normal mechanotransduction and morphology of hair bundles.

  7. Properties of the microcirculation in capillary bundles of rat spinotrapezius muscle fascia

    Science.gov (United States)

    Jacobitz, Frank; Engebrecht, Cheryn; Metzger, Ian; Porterfield, Colin

    2006-11-01

    Properties of the microcirculation in capillary bundles of rat spinotrapezius muscle fascia are investigated using microscope observations, empirical modeling, and numerical simulations. Capillary bundles consist of a network of feeding arterioles, draining venules, and capillary vessels. A dozen samples of muscle fascia tissue were prepared for microscope observation. The chosen method of preparation allows for the long-term preservation of the tissue samples for future studies. Capillary bundles are photographed under a microscope with 40x magnification. From the images, the microvasculature of the tissue samples is reconstructed. It was found, for example, that the distribution of vessel length in a capillary bundle follows a log-normal law. In addition to a statistical analysis of the vessel data, the network topology is used for numerical simulations of the flow in the capillary bundles. The numerical approach uses a sparse-matrix solver and it considers vessel elasticity and blood rheology. The numerical simulations show, for example, a strong pressure drop across the capillary vessels of the bundle.

  8. Fabrication of a CANFLEX-RU designed bundle for power ramp irradiation test in NRU

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Moon Sung

    2000-11-01

    The BDL-443 CANFLEX-RU bundle AKW was fabricated at Korea Atomic Energy Research Institute (KAERI) for power ramp irradiation testing in NRU reactor. The bundle was fabricated with IDR and ADU fuel pellets in adjacent elements and contains fuel pellets enriched to 1.65 wt% {sup 235}U in the outer and intermediate rings and also contains pellets enriched to 2.00 wt% {sup 235}U in the inner ring. This bundle does not have a center element to allow for insertion on a hanger bar. KAERI produced the IDR pellets with the IDR-source UO{sub 2} powder supplied by BNFL. ADU pellets were fabricated and supplied by AECL. Bundle kits (Zircaloy-4 end plates, end plugs, and sheaths with brazed appendages) manufactured at KAERI earlier in 1996 were used for the fabrication of the bundle. The CANFLEX bundle was fabricated successfully at KAERI according to the QA provisions specified in references and as per relevant KAERI drawings and technical specification. This report covers the fabrication activities performed at KAERI. Fabrication processes performed at AECL will be documented in a separate report.

  9. Experimental observation of spatially resolved photo-luminescence intensity distribution in dual mode upconverting nanorod bundles

    Science.gov (United States)

    Kumar, Pawan; Singh, Satbir; Singh, V. N.; Singh, Nidhi; Gupta, R. K.; Gupta, Bipin Kumar

    2017-02-01

    A novel method for demonstration of photoluminescence intensity distribution in upconverting nanorod bundles using confocal microscopy is reported. Herein, a strategy for the synthesis of highly luminescent dual mode upconverting/downshift Y1.94O3:Ho3+0.02/Yb3+0.04 nanorod bundles by a facile hydrothermal route has been introduced. These luminescent nanorod bundles exhibit strong green emission at 549 nm upon excitations at 449 nm and 980 nm with quantum efficiencies of ~6.3% and ~1.1%, respectively. The TEM/HRTEM results confirm that these bundles are composed of several individual nanorods with diameter of ~100 nm and length in the range of 1-3 μm. Furthermore, two dimensional spatially resolved photoluminescence intensity distribution study has been carried out using confocal photoluminescence microscope throughout the nanorod bundles. This study provides a new direction for the potential use of such emerging dual mode nanorod bundles as photon sources for next generation flat panel optical display devices, bio-medical applications, luminescent security ink and enhanced energy harvesting in photovoltaic applications.

  10. Deconstructing the infection control bundles for the containment of carbapenem-resistant Enterobacteriaceae.

    Science.gov (United States)

    Munoz-Price, L Silvia; Quinn, John P

    2013-08-01

    Rates of carbapenem-resistant Enterobacteriaceae (CRE), especially Klebsiella pneumoniae carbapenemase (KPC)-producing Gram-negatives, have increased worldwide. Infections caused by these organisms have been associated with a high mortality, which might be due in part to the limited availability of antibiotic options. Therefore, prevention of acquisition of these organisms is essential. This review summarizes published infection control interventions (bundles) that have been implemented for the control of outbreaks caused by KPC-producing organisms. A total of 15 bundles of interventions aimed at controlling CRE outbreaks are presented. The interventions included combinations of increased compliance with hand hygiene and contact precautions, environmental cleaning, early identification of asymptomatic carriers, and physical separation of CRE-positive patients and their staff. Three bundles had staggered implementation of interventions with their later phase involving a combination of rectal surveillance cultures for identification of asymptomatic CRE carriers, cohorting of CRE-positive patients, and cohorting of the staff caring for CRE carriers. All three staggered bundles successfully decreased their CRE acquisition rates after implementation of their later phases. Bundles combine multiple interventions targeting different levels of the transmission pathways and most include increased hand hygiene and contact precautions. However, bundles implemented in phases would seem to indicate that active surveillance cultures and the subsequent cohorting of patients and staff based on these results might be particularly beneficial for controlling horizontal transmission.

  11. Nonlinear Diffusion and Transient Osmosis

    Science.gov (United States)

    Akira, Igarashi; Lamberto, Rondoni; Antonio, Botrugno; Marco, Pizzi

    2011-08-01

    We investigate both analytically and numerically the concentration dynamics of a solution in two containers connected by a narrow and short channel, in which diffusion obeys a porous medium equation. We also consider the variation of the pressure in the containers due to the flow of matter in the channel. In particular, we identify a phenomenon, which depends on the transport of matter across nano-porous membranes, which we call “transient osmosis". We find that nonlinear diffusion of the porous medium equation type allows numerous different osmotic-like phenomena, which are not present in the case of ordinary Fickian diffusion. Experimental results suggest one possible candidate for transiently osmotic processes.

  12. Simulation of Transient Viscoelastic Flow

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz; Hassager, Ole

    1993-01-01

    The Lagrangian kinematic description is used to develop a numerical method for simulation of time-dependent flow of viscoelastic fluids described by integral models. The method is shown to converge to first order in the time step and at least second order in the spatial discretization. The method...... is tested on the established sphere in a cylinder benchmark problem, and an extension of the problem to transient flow is proposed....

  13. Simulation Model of a Transient

    DEFF Research Database (Denmark)

    Jauch, Clemens; Sørensen, Poul; Bak-Jensen, Birgitte

    2005-01-01

    This paper describes the simulation model of a controller that enables an active-stall wind turbine to ride through transient faults. The simulated wind turbine is connected to a simple model of a power system. Certain fault scenarios are specified and the turbine shall be able to sustain operation...... in case of such faults. The design of the controller is described and its performance assessed by simulations. The control strategies are explained and the behaviour of the turbine discussed....

  14. Transient virulence of emerging pathogens.

    Science.gov (United States)

    Bolker, Benjamin M; Nanda, Arjun; Shah, Dharmini

    2010-05-06

    Should emerging pathogens be unusually virulent? If so, why? Existing theories of virulence evolution based on a tradeoff between high transmission rates and long infectious periods imply that epidemic growth conditions will select for higher virulence, possibly leading to a transient peak in virulence near the beginning of an epidemic. This transient selection could lead to high virulence in emerging pathogens. Using a simple model of the epidemiological and evolutionary dynamics of emerging pathogens, along with rough estimates of parameters for pathogens such as severe acute respiratory syndrome, West Nile virus and myxomatosis, we estimated the potential magnitude and timing of such transient virulence peaks. Pathogens that are moderately evolvable, highly transmissible, and highly virulent at equilibrium could briefly double their virulence during an epidemic; thus, epidemic-phase selection could contribute significantly to the virulence of emerging pathogens. In order to further assess the potential significance of this mechanism, we bring together data from the literature for the shapes of tradeoff curves for several pathogens (myxomatosis, HIV, and a parasite of Daphnia) and the level of genetic variation for virulence for one (myxomatosis). We discuss the need for better data on tradeoff curves and genetic variance in order to evaluate the plausibility of various scenarios of virulence evolution.

  15. Cortical computations via transient attractors.

    Directory of Open Access Journals (Sweden)

    Oliver L C Rourke

    Full Text Available The ability of sensory networks to transiently store information on the scale of seconds can confer many advantages in processing time-varying stimuli. How a network could store information on such intermediate time scales, between typical neurophysiological time scales and those of long-term memory, is typically attributed to persistent neural activity. An alternative mechanism which might allow for such information storage is through temporary modifications to the neural connectivity which decay on the same second-long time scale as the underlying memories. Earlier work that has explored this method has done so by emphasizing one attractor from a limited, pre-defined set. Here, we describe an alternative, a Transient Attractor network, which can learn any pattern presented to it, store several simultaneously, and robustly recall them on demand using targeted probes in a manner reminiscent of Hopfield networks. We hypothesize that such functionality could be usefully embedded within sensory cortex, and allow for a flexibly-gated short-term memory, as well as conferring the ability of the network to perform automatic de-noising, and separation of input signals into distinct perceptual objects. We demonstrate that the stored information can be refreshed to extend storage time, is not sensitive to noise in the system, and can be turned on or off by simple neuromodulation. The diverse capabilities of transient attractors, as well as their resemblance to many features observed in sensory cortex, suggest the possibility that their actions might underlie neural processing in many sensory areas.

  16. Igniter heater EMI transient test

    Science.gov (United States)

    Cook, M.

    1989-01-01

    Testing to evaluate Redesigned Solid Rocket Motor igniter heater electromagnetic interference (EMI) effects on the Safe and Arm (S and A) device was completed. It was suspected that EMI generated by the igniter heater and it's associated electromechanical relay could cause a premature firing of the NASA Standard Initiators (NSIs) inside the S and A. The maximum voltage induced into the NSI fire lines was 1/4 of the NASA specified no-fire limit of one volt (SKB 26100066). As a result, the igniter heaters are not expected to have any adverse EMI effects on the NSIs. The results did show, however, that power switching causes occasional high transients within the igniter heater power cable. These transients could affect the sensitive equipment inside the forward skirt. It is therefore recommended that the electromechanical igniter heater relays be replaced with zero crossing solid state relays. If the solid state relays are installed, it is also recommended that they be tested for EMI transient effects.

  17. Electrical remodelling in patients with iatrogenic left bundle branch block.

    Science.gov (United States)

    Engels, Elien B; Poels, Thomas T; Houthuizen, Patrick; de Jaegere, Peter P T; Maessen, Jos G; Vernooy, Kevin; Prinzen, Frits W

    2016-12-01

    Left bundle branch block (LBBB) is induced in approximately one-third of all transcatheter aortic valve implantation (TAVI) procedures. We investigated electrophysiological remodelling in patients with TAVI-induced LBBB. This retrospective study comprises 107 patients with initially narrow QRS complex of whom 40 did not and 67 did develop persistent LBBB after TAVI. 12-lead electrocardiograms (ECGs) taken before TAVI, within 24 hours ('acute'), and 1-12 months after TAVI ('chronic') were used to reconstruct vectorcardiograms. From these vectorcardiograms, QRS and T-wave area were calculated as comprehensive indices of depolarization and repolarization abnormalities, respectively. TAVI-induced LBBB resulted in significant acute depolarization and repolarization changes while further repolarization changes were observed with longer lasting LBBB. The amount of long-term repolarization changes (remodelling) was highly variable between patients. The change in T-wave area between acute and chronic LBBB ranged from +57% to - 77%. After dividing the LBBB cohort into tertiles based on the change in T-wave area, only baseline QRS area was larger in the tertile with no significant change in T-wave area. During longer lasting LBBB, the spatial vector gradient (SVG) changed orientation towards the direction of the QRS-vector, indicating that later-activated regions developed shorter action potential duration. This study in patients with TAVI-induced LBBB shows that repolarization changes develop within months after onset of LBBB, and that these changes are highly variable between individual patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For Permissions, please email: journals.permissions@oup.com.

  18. Fiber bundle probes for interconnecting miniaturized medical imaging devices

    Science.gov (United States)

    Zamora, Vanessa; Hofmann, Jens; Marx, Sebastian; Herter, Jonas; Nguyen, Dennis; Arndt-Staufenbiel, Norbert; Schröder, Henning

    2017-02-01

    Miniaturization of medical imaging devices will significantly improve the workflow of physicians in hospitals. Photonic integrated circuit (PIC) technologies offer a high level of miniaturization. However, they need fiber optic interconnection solutions for their functional integration. As part of European funded project (InSPECT) we investigate fiber bundle probes (FBPs) to be used as multi-mode (MM) to single-mode (SM) interconnections for PIC modules. The FBP consists of a set of four or seven SM fibers hexagonally distributed and assembled into a holder that defines a multicore connection. Such a connection can be used to connect MM fibers, while each SM fiber is attached to the PIC module. The manufacturing of these probes is explored by using well-established fiber fusion, epoxy adhesive, innovative adhesive and polishing techniques in order to achieve reliable, low-cost and reproducible samples. An innovative hydrofluoric acid-free fiber etching technology has been recently investigated. The preliminary results show that the reduction of the fiber diameter shows a linear behavior as a function of etching time. Different etch rate values from 0.55 μm/min to 2.3 μm/min were found. Several FBPs with three different type of fibers have been optically interrogated at wavelengths of 630nm and 1550nm. Optical losses are found of approx. 35dB at 1550nm for FBPs composed by 80μm fibers. Although FBPs present moderate optical losses, they might be integrated using different optical fibers, covering a broad spectral range required for imaging applications. Finally, we show the use of FBPs as promising MM-to-SM interconnects for real-world interfacing to PIC's.

  19. Transient combustion in hybrid rockets

    Science.gov (United States)

    Karabeyoglu, Mustafa Arif

    1998-09-01

    Hybrid rockets regained interest recently as an alternative chemical propulsion system due to their advantages over the solid and liquid systems that are currently in use. Development efforts on hybrids revealed two important problem areas: (1) low frequency instabilities and (2) slow transient response. Both of these are closely related to the transient behavior which is a poorly understood aspect of hybrid operation. This thesis is mainly involved with a theoretical study of transient combustion in hybrid rockets. We follow the methodology of identifying and modeling the subsystems of the motor such as the thermal lags in the solid, boundary layer combustion and chamber gasdynamics from a dynamic point of view. We begin with the thermal lag in the solid which yield the regression rate for any given wall heat flux variation. Interesting phenomena such as overshooting during throttling and the amplification and phase lead regions in the frequency domain are discovered. Later we develop a quasi-steady transient hybrid combustion model supported with time delays for the boundary layer processes. This is integrated with the thermal lag system to obtain the thermal combustion (TC) coupled response. The TC coupled system with positive delays generated low frequency instabilities. The scaling of the instabilities are in good agreement with actual motor test data. Finally, we formulate a gasdynamic model for the hybrid chamber which successfully resolves the filling/emptying and longitudinal acoustic behavior of the motor. The TC coupled system is later integrated to the gasdynamic model to obtain the overall response (TCG coupled system) of gaseous oxidizer motors with stiff feed systems. Low frequency instabilities were also encountered for the TCG coupled system. Apart from the transient investigations, the regression rate behavior of liquefying hybrid propellants such as solid cryogenic materials are also studied. The theory is based on the possibility of enhancement

  20. Design and impact of bundled payment for detox and follow-up care.

    Science.gov (United States)

    Quinn, Amity E; Hodgkin, Dominic; Perloff, Jennifer N; Stewart, Maureen T; Brolin, Mary; Lane, Nancy; Horgan, Constance M

    2017-11-01

    Recent payment reforms promote movement from fee-for-service to alternative payment models that shift financial risk from payers to providers, incentivizing providers to manage patients' utilization. Bundled payment, an episode-based fixed payment that includes the prices of a group of services that would typically treat an episode of care, is expanding in the United States. Bundled payment has been recommended as a way to pay for comprehensive SUD treatment and has the potential to improve treatment engagement after detox, which could reduce detox readmissions, improve health outcomes, and reduce medical care costs. However, if moving to bundled payment creates large losses for some providers, it may not be sustainable. The objective of this study was to design the first bundled payment for detox and follow-up care and to estimate its impact on provider revenues. Massachusetts Medicaid beneficiaries' behavioral health, medical, and pharmacy claims from July 2010-April 2013 were used to build and test a detox bundled payment for continuously enrolled adults (N=5521). A risk adjustment model was developed using general linear modeling to predict beneficiaries' episode costs. The projected payments to each provider from the risk adjustment analysis were compared to the observed baseline costs to determine the potential impact of a detox bundled payment reform on organizational revenues. This was modeled in two ways: first assuming no change in behavior and then assuming a supply-side cost sharing behavioral response of a 10% reduction in detox readmissions and an increase of one individual counseling and one group counseling session. The mean total 90-day detox episode cost was $3743. Nearly 70% of the total mean cost consists of the index detox, psychiatric inpatient care, and short-term residential care. Risk mitigation, including risk adjustment, substantially reduced the variation of the mean episode cost. There are opportunities for organizations to gain revenue