Intra-His bundle block: clinical, electrocardiographic, and electrophysiologic characteristics
Andréa Eduardo M.; Atié Jacob; Maciel Washington A.; Oliveira Jr Nilson A. de; Camanho Luiz Eduardo; Belo Luís Gustavo; Carvalho Hecio Affonso de; Siqueira Leonardo; Saad Eduardo; Venancio Ana Claudia
2002-01-01
OBJECTIVE: To assess the clinical, electrocardiographic, and electrophysiologic characteristics of patients (pt) with intra-His bundle block undergoing an electrophysiologic study (EPS). METHODS: We analyzed the characteristics of 16 pt with second-degree atrioventricular block and symptoms of syncope or dyspnea, or both, undergoing conventional EPS. RESULTS: Intra-His bundle block was documented in 16 pt during an EPS. In 15 (94%) pt, the atrioventricular block was recorded in sinus rhythm; ...
International Nuclear Information System (INIS)
The increase of bundle supply has become widespread in several sectors (for instance in telecommunications and energy fields). This paper review relates strategic aspects of bundling. The main purpose of this paper is to analyze profitability of bundling strategies according to the degree of competition and the characteristics of goods. Moreover, bundling can be used as price discrimination tool, screening device or entry barriers. In monopoly case bundling strategy is efficient to sort consumers in different categories in order to capture a maximum of surplus. However, when competition increases, the profitability on bundling strategies depends on correlation of consumers' reservations values. (author)
Befeler, B; Castellanos, A; Aranda, J; Gutierrez, R; Lazzara, R
1976-02-01
Intracardiac electrophysiological studies were performed in two patients with a documented history of repetitive supraventricular tachyarrhythmias. Case 1, with short PR interval and narrow QRS complexes had a short AH interval and intermittent right bundle-branch block. Thus the short PR wide QRS syndrome is not always a result of the Wolff-Parkinson-White syndrome but can also be seen in the Lown-Ganong-Levine syndrome coexisting with bundle-branch block. Case 2, with normal PR and AH at the lower limits of normal, showed the dual pathway response to atrial pacing that can occur in patients with Lown-Ganong-Levine syndrome. He also had tachycardia-dependent right bundle-branch block and left posterior hemiblock. Therefore, neither the short PR interval nor the narrow QRS complexes characterized these forms of pre-excitation. The constant features were, from the clinical viewpoint, the occurrence of repetitive supraventricular tachyarrhythmias, and electrophysiologically the abnormal response to atrial stimulation.
Restrictions of stable bundles
Balaji, V
2011-01-01
The Mehta-Ramanathan theorem ensures that the restriction of a stable vector bundle to a sufficiently high degree complete intersection curve is again stable. We improve the bounds for the "sufficiently high degree" and propose a possibly optimal conjecture.
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.
Deformation quantization of principal bundles
Aschieri, Paolo
2016-01-01
We outline how Drinfeld twist deformation techniques can be applied to the deformation quantization of principal bundles into noncommutative principal bundles, and more in general to the deformation of Hopf-Galois extensions. First we twist deform the structure group in a quantum group, and this leads to a deformation of the fibers of the principal bundle. Next we twist deform a subgroup of the group of authomorphisms of the principal bundle, and this leads to a noncommutative base space. Considering both deformations we obtain noncommutative principal bundles with noncommutative fiber and base space as well.
Cassou-Nogues, Ph.; Erez, B.; Taylor, M. J.
2004-01-01
We establish comparison results between the Hasse-Witt invariants w_t(E) of a symmetric bundle E over a scheme and the invariants of one of its twists E_{\\alpha}. For general twists we describe the difference between w_t(E) and w_t(E_{\\alpha}) up to terms of degree 3. Next we consider a special kind of twist, which has been studied by A. Fr\\"ohlich. This arises from twisting by a cocycle obtained from an orthogonal representation. We show how to explicitly describe the twist for representatio...
Cohomology of line bundles: Applications
Blumenhagen, Ralph; Jurke, Benjamin; Rahn, Thorsten; Roschy, Helmut
2012-01-01
Massless modes of both heterotic and Type II string compactifications on compact manifolds are determined by vector bundle valued cohomology classes. Various applications of our recent algorithm for the computation of line bundle valued cohomology classes over toric varieties are presented. For the heterotic string, the prime examples are so-called monad constructions on Calabi-Yau manifolds. In the context of Type II orientifolds, one often needs to compute cohomology for line bundles on finite group action coset spaces, necessitating us to generalize our algorithm to this case. Moreover, we exemplify that the different terms in Batyrev's formula and its generalizations can be given a one-to-one cohomological interpretation. Furthermore, we derive a combinatorial closed form expression for two Hodge numbers of a codimension two Calabi-Yau fourfold.
Failure properties of fiber bundle models
Pradhan, Srutarshi; Chakrabarti, Bikas K.
2003-01-01
We study the failure properties of fiber bundles when continuous rupture goes on due to the application of external load on the bundles. We take the two extreme models: equal load sharing model (democratic fiber bundles) and local load sharing model. The strength of the fibers are assumed to be distributed randomly within a finite interval. The democratic fiber bundles show a solvable phase transition at a critical stress (load per fiber). The dynamic critical behavior is obtained analyticall...
Intra-His bundle block in 2:1 atrioventricular block
Institute of Scientific and Technical Information of China (English)
Seung; Pyo; Hong; Yon; Woong; Park; Young; Soo; Lee
2015-01-01
Intra-hisian atrioventricular(AV) block is not a common phenomenon, but it is important for the development of advanced or complete AV block. We observed a 77-yearold female patient with the 2:1 AV block due to an intrahisian block. In this case we tried to detect the block site, but an alternating pattern of the AH conduction was noted on the His-electrogram in the electrophysiological study(EPS). The cause of the confusing finding might have been the instability of the catheter to record a His potential. We could detect a splitting of the Hiselectrogram with an intra-hisian block after minimal manipulation of the catheter. The authors’ observations suggest that catheter stability is important for a precise recording in the EPS and radiofrequency catheter ablation procedure.
Damping Properties of the Hair Bundle
Baumgart, Johannes; Kozlov, Andrei S.; Risler, Thomas; Hudspeth, A. James
2015-01-01
The viscous liquid surrounding a hair bundle dissipates energy and dampens oscillations, which poses a fundamental physical challenge to the high sensitivity and sharp frequency selectivity of hearing. To identify the mechanical forces at play, we constructed a detailed finite-element model of the hair bundle. Based on data from the hair bundle of the bullfrog's sacculus, this model treats the interaction of stereocilia both with the surrounding liquid and with the liquid in the narrow gaps b...
Static stress analysis of CANFLEX fuel bundles
International Nuclear Information System (INIS)
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
Statistical Constitutive Equation of Aramid Fiber Bundles
Institute of Scientific and Technical Information of China (English)
熊杰; 顾伯洪; 王善元
2003-01-01
Tensile impact tests of aramid (Twaron) fiber bundles were carried om under high strain rates with a wide range of 0. 01/s～1000/s by using MTS and bar-bar tensile impact apparatus. Based on the statistical constitutive model of fiber bundles, statistical constitutive equations of aramid fiber bundles are derived from statistical analysis of test data at different strain rates. Comparison between the theoretical predictions and experimental data indicates statistical constitutive equations fit well with the experimental data, and statistical constitutive equations of fiber bundles at different strain rates are valid.
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)
Damping Properties of the Hair Bundle
Baumgart, Johannes; Kozlov, Andrei S.; Risler, Thomas; Hudspeth, A. J.
2011-11-01
The viscous liquid surrounding a hair bundle dissipates energy and dampens oscillations, which poses a fundamental physical challenge to the high sensitivity and sharp frequency selectivity of hearing. To identify the mechanical forces at play, we constructed a detailed finite-element model of the hair bundle. Based on data from the hair bundle of the bullfrog's sacculus, this model treats the interaction of stereocilia both with the surrounding liquid and with the liquid in the narrow gaps between the individual stereocilia. The investigation revealed that grouping stereocilia in a bundle dramatically reduces the total drag. During hair-bundle deflections, the tip links potentially induce drag by causing small but very dissipative relative motions between stereocilia; this effect is offset by the horizontal top connectors that restrain such relative movements at low frequencies. For higher frequencies the coupling liquid is sufficient to assure that the hair bundle moves as a unit with a low total drag. This work reveals the mechanical characteristics originating from hair-bundle morphology and shows quantitatively how a hair bundle is adapted for sensitive mechanotransduction.
Deformations of the generalised Picard bundle
International Nuclear Information System (INIS)
Let X be a nonsingular algebraic curve of genus g ≥ 3, and let Mξ denote the moduli space of stable vector bundles of rank n ≥ 2 and degree d with fixed determinant ξ over X such that n and d are coprime. We assume that if g = 3 then n ≥ 4 and if g = 4 then n ≥ 3, and suppose further that n0, d0 are integers such that n0 ≥ 1 and nd0 + n0d > nn0(2g - 2). Let E be a semistable vector bundle over X of rank n0 and degree d0. The generalised Picard bundle Wξ(E) is by definition the vector bundle over Mξ defined by the direct image pMξ *(Uξ x pX*E) where Uξ is a universal vector bundle over X x Mξ. We obtain an inversion formula allowing us to recover E from Wξ(E) and show that the space of infinitesimal deformations of Wξ(E) is isomorphic to H1(X, End(E)). This construction gives a locally complete family of vector bundles over Mξ parametrised by the moduli space M(n0,d0) of stable bundles of rank n0 and degree d0 over X. If (n0,d0) = 1 and Wξ(E) is stable for all E is an element of M(n0,d0), the construction determines an isomorphism from M(n0,d0) to a connected component M0 of a moduli space of stable sheaves over Mξ. This applies in particular when n0 = 1, in which case M0 is isomorphic to the Jacobian J of X as a polarised variety. The paper as a whole is a generalisation of results of Kempf and Mukai on Picard bundles over J, and is also related to a paper of Tyurin on the geometry of moduli of vector bundles. (author)
Geometry of quantum principal bundles, 1
Durdevic, M
1995-01-01
A theory of principal bundles possessing quantum structure groups and classical base manifolds is presented. Structural analysis of such quantum principal bundles is performed. A differential calculus is constructed, combining differential forms on the base manifold with an appropriate differential calculus on the structure quantum group. Relations between the calculus on the group and the calculus on the bundle are investigated. A concept of (pseudo)tensoriality is formulated. The formalism of connections is developed. In particular, operators of horizontal projection, covariant derivative and curvature are constructed and analyzed. Generalizations of the first structure equation and of the Bianchi identity are found. Illustrative examples are presented.
Weak equivalence classes of complex vector bundles
Hông-Vân Lê
2006-01-01
For any complex vector bundle Ek of rank k over a manifold Mm with Chern classes ci Î H2i(Mm, Z) and any non-negative integers l1, . . ., lk we show the existence of a positive number p(m, k) and the existence of a complex vector bundle Êk over Mm whose Chern classes are p(m, k) × li × ci Î H2i(Mm, Z). We also discuss a version of this statement for holomorphic vector bundles over projective algebraic manifolds.
Quantum Bundle Description of Quantum Projective Spaces
Ó Buachalla, Réamonn
2012-12-01
We realise Heckenberger and Kolb's canonical calculus on quantum projective ( N - 1)-space C q [ C p N-1] as the restriction of a distinguished quotient of the standard bicovariant calculus for the quantum special unitary group C q [ SU N ]. We introduce a calculus on the quantum sphere C q [ S 2 N-1] in the same way. With respect to these choices of calculi, we present C q [ C p N-1] as the base space of two different quantum principal bundles, one with total space C q [ SU N ], and the other with total space C q [ S 2 N-1]. We go on to give C q [ C p N-1] the structure of a quantum framed manifold. More specifically, we describe the module of one-forms of Heckenberger and Kolb's calculus as an associated vector bundle to the principal bundle with total space C q [ SU N ]. Finally, we construct strong connections for both bundles.
Mobility of Taxol in Microtubule Bundles
Ross, J.
2003-06-01
Mobility of taxol inside microtubules was investigated using fluorescence recovery after photobleaching (FRAP) on flow-aligned bundles. Bundles were made of microtubules with either GMPCPP or GTP at the exchangeable site on the tubulin dimer. Recovery times were sensitive to bundle thickness and packing, indicating that taxol molecules are able to move laterally through the bundle. The density of open binding sites along a microtubule was varied by controlling the concentration of taxol in solution for GMPCPP samples. With > 63% sites occupied, recovery times were independent of taxol concentration and, therefore, inversely proportional to the microscopic dissociation rate, k_{off}. It was found that 10*k_{off} (GMPCPP) ~ k_{off} (GTP), consistent with, but not fully accounting for, the difference in equilibrium constants for taxol on GMPCPP and GTP microtubules. With taxol along the microtubule interior is hindered by rebinding events when open sites are within ~7 nm of each other.
Institute of Scientific and Technical Information of China (English)
YU Wei-dong; YAN Hao-jing; Ron Postle; Yang Shouren
2002-01-01
Due to the effects of samples and testing conditions on fibre-bundle tensile behaviour, it is necessary to investigate the relationships between experimental factors and tensile properties for the fibre-bumdle tensile tester (TENSOR). The effects of bundle sample preparation, fibre bundle mass and fibre alignment have been tested. The experimental results indicated that (1) the low damage in combing and no free-end fibres in the cut bundle are most important for the sample preparation; (2) the reasonable bundle mass is 400- 700tex, but the tensile properties measured should bemodified with the bundle mass because a small amount of bundle mass causes the scatter results, while the larger is the bundle mass, the more difficult to comb fibres parallel and to clamp fibre evenly; and (3) the fibre irregular arrangement forms a slack bundle resulting in interaction between fibres, which will affect the reproducibility and accuracy of the tensile testing.
Tangent bundle formulation of a charged gas
Sarbach, Olivier
2013-01-01
We discuss the relativistic kinetic theory for a simple, collisionless, charged gas propagating on an arbitrary curved spacetime geometry. Our general relativistic treatment is formulated on the tangent bundle of the spacetime manifold and takes advantage of its rich geometric structure. In particular, we point out the existence of a natural metric on the tangent bundle and illustrate its role for the development of the relativistic kinetic theory. This metric, combined with the electromagnetic field of the spacetime, yields an appropriate symplectic form on the tangent bundle. The Liouville vector field arises as the Hamiltonian vector field of a natural Hamiltonian. The latter also defines natural energy surfaces, called mass shells, which turn out to be smooth Lorentzian submanifolds. A simple, collisionless, charged gas is described by a distribution function which is defined on the mass shell and satisfies the Liouville equation. Suitable fibre integrals of the distribution function define observable fie...
Characteristic classes of quantum principal bundles
Durdevic, M
1995-01-01
A noncommutative-geometric generalization of classical Weil theory of characteristic classes is presented, in the conceptual framework of quantum principal bundles. A particular care is given to the case when the bundle does not admit regular connections. A cohomological description of the domain of the Weil homomorphism is given. Relations between universal characteristic classes for the regular and the general case are analyzed. In analogy with classical geometry, a natural spectral sequence is introduced and investigated. The appropriate counterpart of the Chern character is constructed, for structures admitting regular connections. Illustrative examples and constructions are presented.
A bundle of sticks in my garden
Farran, Sue
2012-01-01
The English law of property is often described as a ‘bundle of sticks’ in which each ‘stick’ represents a particular right. Gardens challenge these rights and wreak havoc on the ‘bundle of sticks’. This paper looks at the twenty-first century manifestations of community engagement with ground and explores how ‘gardening’ is undermining concepts of ownership, possession and management of land and how the fence between what is private and what is public is being encroached and challenged by com...
Computations in intersection rings of flag bundles
Grayson, Daniel R; Stillman, Michael E
2012-01-01
Intersection rings of flag varieties and of isotropic flag varieties are generated by Chern classes of the tautological bundles modulo the relations coming from multiplicativity of total Chern classes. In this paper we describe the Groebner bases of the ideals of relations and give applications to computation of intersections, as implemented in Macaulay2.
Yoo, Yon-Sik; Song, Si Young; Yang, Cheol Jung; Ha, Jong Mun; Kim, Yoon Sang
2016-01-01
Purpose The purpose of this study was to compare the clinical outcomes of arthroscopic anatomical double bundle (DB) anterior cruciate ligament (ACL) reconstruction with either selective anteromedial (AM) or posterolateral (PL) bundle reconstruction while preserving a relatively healthy ACL bundle. Materials and Methods The authors evaluated 98 patients with a mean follow-up of 30.8±4.0 months who had undergone DB or selective bundle ACL reconstructions. Of these, 34 cases underwent DB ACL reconstruction (group A), 34 underwent selective AM bundle reconstruction (group B), and 30 underwent selective PL bundle reconstructions (group C). These groups were compared with respect to Lysholm and International Knee Documentation Committee (IKDC) score, side-to-side differences of anterior laxity measured by KT-2000 arthrometer at 30 lbs, and stress radiography and Lachman and pivot shift test results. Pre- and post-operative data were objectively evaluated using a statistical approach. Results The preoperative anterior instability measured by manual stress radiography at 90° of knee flexion in group A was significantly greater than that in groups B and C (all panterior instability measured by KT-2000 arthrometer, pivot shift, or functional scores. Conclusion Selective bundle reconstruction in partial ACL tears offers comparable clinical results to DB reconstruction in complete ACL tears. PMID:27401652
Optimization of a bundle divertor for FED
International Nuclear Information System (INIS)
Optimal double-T bundle divertor configurations have been obtained for the Fusion Engineering Device (FED). On-axis ripple is minimized, while satisfying a series of engineering constraints. The ensuing non-linear optimization problem is solved via a sequence of quadratic programming subproblems, using the VMCON algorithm. The resulting divertor designs are substantially improved over previous configurations
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...
Impact of bundle deformation on CHF: ASSERT-PV assessment of extended burnup Bruce B bundle G85159W
International Nuclear Information System (INIS)
This paper presents a subchannel thermalhydraulic analysis of the effect on critical heat flux (CHF) of bundle deformation such as element bow and diametral creep. The bundle geometry is based on the post-irradiation examination (PIE) data of a single bundle from the Bruce B Nuclear Generating Station, Bruce B bundle G85159W, which was irradiated for more than two years in the core during reactor commissioning. The subchannel code ASSERT-PV IST is used to assess changes in CHF and dryout power due to bundle deformation, compared to the reference, undeformed bundle. (author)
The unintended consequences of bundled payments.
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.
Compactifications of reductive groups as moduli stacks of bundles
DEFF Research Database (Denmark)
Martens, Johan; Thaddeus, Michael
Let G be a reductive group. We introduce the moduli problem of "bundle chains" parametrizing framed principal G-bundles on chains of lines. Any fan supported in a Weyl chamber determines a stability condition on bundle chains. Its moduli stack provides an equivariant toroidal compactification of G...
Stability of Picard Bundle Over Moduli Space of Stable Vector Bundles of Rank Two Over a Curve
Indian Academy of Sciences (India)
Indranil Biswas; Tomás L Gómez
2001-08-01
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.
In-pile test of Qinshan PWR fuel bundle
International Nuclear Information System (INIS)
In-pile test of Qinshan Nuclear Power Plant PWR fuel bundle has been conducted in HWRR HTHP Test loop at CIAE. The test fuel bundle was irradiated to an average burnup of 25000 Mwd/tU. The authors describe the structure of (3 x 3-2) test fuel bundle, structure of irradiation rig, fuel fabrication, irradiation conditions, power and fuel burnup. Some comments on the in-pile performance for fuel bundle, fuel rod and irradiation rig were made
Geometry of torus bundles in integrable Hamiltonian systems
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 real-worl
Fingal, Diana
2009-01-01
Technology has changed for the past three decades, but the issues have not. Educators still face barriers to incorporating technology into their lessons. In the past, Dave Moursund, the first executive director of International Society for Technology in Education, wrote editorials predicting technology's impact on education. In this article, the…
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
Yoo, Yon-Sik; Song, Si Young; Yang, Cheol Jung; Ha, Jong Mun; Kim, Yoon Sang
2016-01-01
Purpose The purpose of this study was to compare the clinical outcomes of arthroscopic anatomical double bundle (DB) anterior cruciate ligament (ACL) reconstruction with either selective anteromedial (AM) or posterolateral (PL) bundle reconstruction while preserving a relatively healthy ACL bundle. Materials and Methods The authors evaluated 98 patients with a mean follow-up of 30.8±4.0 months who had undergone DB or selective bundle ACL reconstructions. Of these, 34 cases underwent DB ACL reconstruction (group A), 34 underwent selective AM bundle reconstruction (group B), and 30 underwent selective PL bundle reconstructions (group C). These groups were compared with respect to Lysholm and International Knee Documentation Committee (IKDC) score, side-to-side differences of anterior laxity measured by KT-2000 arthrometer at 30 lbs, and stress radiography and Lachman and pivot shift test results. Pre- and post-operative data were objectively evaluated using a statistical approach. Results The preoperative anterior instability measured by manual stress radiography at 90° of knee flexion in group A was significantly greater than that in groups B and C (all pACL tears offers comparable clinical results to DB reconstruction in complete ACL tears. PMID:27401652
Covariance and the hierarchy of frame bundles
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.
Effective freeness of adjoint line bundles
Heier, Gordon
2001-01-01
In this note we establish a new Fujita-type effective bound for the base point freeness of adjoint line bundles on a compact complex projective manifold of complex dimension $n$. The bound we obtain (approximately) differs from the linear bound conjectured by Fujita only by a factor of the cube root of $n$. As an application, a new effective statement for pluricanonical embeddings is derived.
Reactor application of an improved bundle divertor
International Nuclear Information System (INIS)
A Bundle Divertor was chosen as the impurity control and plasma exhaust system for the beam driven Demonstration Tokamak Hybrid Reactor - DTHR. In the context of a preconceptual design study of the reactor and associated facility a bundle divertor concept was developed and integrated into the reactor system. The overall system was found feasible and scalable for reactors with intermediate torodial field strengths on axis. The important design characteristics are: the overall average current density of the divertor coils is 0.73 kA for each tesla of toroidal field on axis; the divertor windings are made from super-conducting cables supported by steel structures and are designed to be maintainable; the particle collection assembly and auxiliary cryosorption vacuum pump are dual systems designed such that they can be reactivated alterntively to allow for continuous reactor operation; and the power requirement for energizing and operating the divertor is about 5 MW
Effectiveness of Hair Bundle Motility as the Cochlear Amplifier
Sul, Bora; Iwasa, Kuni H.
2009-01-01
The effectiveness of hair bundle motility in mammalian and avian ears is studied by examining energy balance for a small sinusoidal displacement of the hair bundle. The condition that the energy generated by a hair bundle must be greater than energy loss due to the shear in the subtectorial gap per hair bundle leads to a limiting frequency that can be supported by hair-bundle motility. Limiting frequencies are obtained for two motile mechanisms for fast adaptation, the channel re-closure mode...
Deformations of Fell bundles and twisted graph algebras
Raeburn, Iain
2016-11-01
We consider Fell bundles over discrete groups, and the C*-algebra which is universal for representations of the bundle. We define deformations of Fell bundles, which are new Fell bundles with the same underlying Banach bundle but with the multiplication deformed by a two-cocycle on the group. Every graph algebra can be viewed as the C*-algebra of a Fell bundle, and there are are many cocycles of interest with which to deform them. We thus obtain many of the twisted graph algebras of Kumjian, Pask and Sims. We demonstate the utility of our approach to these twisted graph algebras by proving that the deformations associated to different cocycles can be assembled as the fibres of a C*-bundle.
Compression of a bundle of light rays.
Marcuse, D
1971-03-01
The performance of ray compression devices is discussed on the basis of a phase space treatment using Liouville's theorem. It is concluded that the area in phase space of the input bundle of rays is determined solely by the required compression ratio and possible limitations on the maximum ray angle at the output of the device. The efficiency of tapers and lenses as ray compressors is approximately equal. For linear tapers and lenses the input angle of the useful rays must not exceed the compression ratio. The performance of linear tapers and lenses is compared to a particular ray compressor using a graded refractive index distribution.
An analytical fiber bundle model for pullout mechanics of root bundles
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
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...... of the nilpotent cone in $M_H(r,d)$. This generalizes to Higgs $G$-bundles and also to the parabolic Higgs bundles....
Differential geometry of complex vector bundles
Kobayashi, Shoshichi
2014-01-01
Holomorphic vector bundles have become objects of interest not only to algebraic and differential geometers and complex analysts but also to low dimensional topologists and mathematical physicists working on gauge theory. This book, which grew out of the author's lectures and seminars in Berkeley and Japan, is written for researchers and graduate students in these various fields of mathematics. Originally published in 1987. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeto
The equivalence of bundling and advance sales
Alexandrov, Alexei; Bedre-Defolie, Özlem
2013-01-01
We show that a monopolist's problem of optimal advance selling strategy can be mathematically transformed into a problem of optimal bundling strategy if four conditions hold: i. consumers and the firm agree on the probability of the states occurring, ii. the firm pre-commits to the spot prices to be charged in the advance selling stage, iii. consumers are risk-neutral, and iv. consumers and the firm do not have time preferences or when they do have time preferences, they discount future at th...
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.
Amplitude death of coupled hair bundles with stochastic channel noise
Kim, Kyung-Joong
2014-01-01
Hair cells conduct auditory transduction in vertebrates. In lower vertebrates such as frogs and turtles, due to the active mechanism in hair cells, hair bundles(stereocilia) can be spontaneously oscillating or quiescent. Recently, the amplitude death phenomenon has been proposed [K.-H. Ahn, J. R. Soc. Interface, {\\bf 10}, 20130525 (2013)] as a mechanism for auditory transduction in frog hair-cell bundles, where sudden cessation of the oscillations arises due to the coupling between non-identical hair bundles. The gating of the ion channel is intrinsically stochastic due to the stochastic nature of the configuration change of the channel. The strength of the noise due to the channel gating can be comparable to the thermal Brownian noise of hair bundles. Thus, we perform stochastic simulations of the elastically coupled hair bundles. In spite of stray noisy fluctuations due to its stochastic dynamics, our simulation shows the transition from collective oscillation to amplitude death as inter-bundle coupling str...
A Tannakian approach to dimensional reduction of principal bundles
Álvarez-Cónsul, Luis; García-Prada, Oscar
2016-01-01
Let $P$ be a parabolic subgroup of a connected simply connected complex semisimple Lie group $G$. Given a compact K\\"ahler manifold $X$, the dimensional reduction of $G$-equivariant holomorphic vector bundles over $X\\times G/P$ was carried out by the first and third authors. This raises the question of dimensional reduction of holomorphic principal bundles over $X\\times G/P$. The method used for equivariant vector bundles does not generalize to principal bundles. In this paper, we adapt to equivariant principal bundles the Tannakian approach of Nori, to describe the dimensional reduction of $G$-equivariant principal bundles over $X\\times G/P$, and to establish a Hitchin--Kobayashi type correspondence. In order to be able to apply the Tannakian theory, we need to assume that $X$ is a complex projective manifold.
Robust Mapping of Incoherent Fiber-Optic Bundles
Roberts, Harry E.; Deason, Brent E.; DePlachett, Charles P.; Pilgrim, Robert A.; Sanford, Harold S.
2007-01-01
A method and apparatus for mapping between the positions of fibers at opposite ends of incoherent fiber-optic bundles have been invented to enable the use of such bundles to transmit images in visible or infrared light. The method is robust in the sense that it provides useful mapping even for a bundle that contains thousands of narrow, irregularly packed fibers, some of which may be defective. In a coherent fiber-optic bundle, the input and output ends of each fiber lie at identical positions in the input and output planes; therefore, the bundle can be used to transmit images without further modification. Unfortunately, the fabrication of coherent fiber-optic bundles is too labor-intensive and expensive for many applications. An incoherent fiber-optic bundle can be fabricated more easily and at lower cost, but it produces a scrambled image because the position of the end of each fiber in the input plane is generally different from the end of the same fiber in the output plane. However, the image transmitted by an incoherent fiber-optic bundle can be unscrambled (or, from a different perspective, decoded) by digital processing of the output image if the mapping between the input and output fiber-end positions is known. Thus, the present invention enables the use of relatively inexpensive fiber-optic bundles to transmit images.
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)
Steady-flow characteristics of bundle fluid in drawing
Energy Technology Data Exchange (ETDEWEB)
Huh, You; Kim, Jong Seong [Kyunghee University, Suwon (Korea, Republic of)
2006-07-15
Drawing is a mechanical operation attenuating material thickness to an appropriate level for the next processing or end usage. When the input material has a form of bundle or bundles made of very thin and long shaped wires or fibers, this attenuation operation is called 'bundle drawing' or 'drafting'. Bundle drawing is being used widely in manufacturing micro sized wires or staple yarns. However, the bundle processed by this operation has more or less defects in the evenness of linear density. Such irregularities cause many problems not only for the product quality but also for the efficiency of the next successive processes. In this research a mathematical model for the dynamic behavior of the bundle fluid is to be set up on the basis of general physical laws containing physical variables, i.e. linear density and velocity as the dynamic state variables of the bundle fluid. The governing equations resulting from the modeling show that they appear in a slightly different form from what they do in a continuum fluid. Then, the governing equations system is simplified in a steady state and the bundle dynamics is simulated, showing that the shape of the velocity profiles depends on two model parameters. Experiments confirm that the model parameters are to be well adjusted to show a coincidence with the theoretical analysis. The higher the drawing ratio and drawing speed are, the more sensitive becomes the bundle flow to exogenous disturbances.
On the Classification of Complex Vector Bundles of Stable Rank
Indian Academy of Sciences (India)
Constantin Bǎnicǎ; Mihai Putinar
2006-08-01
One describes, using a detailed analysis of Atiyah–Hirzebruch spectral sequence, the tuples of cohomology classes on a compact, complex manifold, corresponding to the Chern classes of a complex vector bundle of stable rank. 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.
Development of nuclear fuel. Development of CANDU advanced fuel bundle
International Nuclear Information System (INIS)
In order to develop CANDU advanced fuel, the agreement of the joint research between KAERI and AECL was made on February 19, 1991. AECL conceptual design of CANFLEX bundle for Bruce reactors was analyzed and then the reference design and design drawing of the advanced fuel bundle with natural uranium fuel for CANDU-6 reactor were completed. The CANFLEX fuel cladding was preliminarily investigated. The fabricability of the advanced fuel bundle was investigated. The design and purchase of the machinery tools for the bundle fabrication for hydraulic scoping tests were performed. As a result of CANFLEX tube examination, the tubes were found to be meet the criteria proposed in the technical specification. The dummy bundles for hydraulic scoping tests have been fabricated by using the process and tools, where the process parameters and tools have been newly established. (Author)
Johan Kommers
2014-01-01
The founder of the Keswick Convention (KC) once was asked to put in a sentence that has brought such a joy into his life and made the name of Keswick fragrant over the whole world. The answer was in the words of the Psalm 16:8, ‘I have set the Lord always before me’. Keswick theology, emphasising sanctification, arose within the concept of the holiness tradition in America with the higher Christian life movement in England during the second part of the 19th century. The merging of several the...
Subanalytic Bundles and Tubular Neighbourhoods of Zero-Loci
Indian Academy of Sciences (India)
Vishwambhar Pati
2003-08-01
We introduce the natural and fairly general notion of a subanalytic bundle (with a finite dimensional vector space of sections) on a subanalytic subset of a real analytic manifold , and prove that when is compact, there is a Baire subset of sections in whose zero-loci in have tubular neighbourhoods, homeomorphic to the restriction of the given bundle to these zero-loci.
Theories of the dorsal bundle extinction effect.
Mason, S T; Iversen, S D
1979-07-01
Selective destruction of the noradrenaline systems in the rat brain using the neurotoxin 6-hydroxydopamine has been found to cause resistance to extinction in a number of behavioural situations. Several theories concerning the behavioural mechanism altered by the lesion, and hence about the role of noradrenaline in normal brain functioning, are proposed and evaluated. Theories suggesting a role for noradrenaline in activity, perseveration, internal inhibition, frustrative non-reward, motivation, or secondary reinforcement, fail to explain all the available evidence and direct tests of each theory fails to support its predictions. A model which suggests that noreadrenaline is involved in attentional behaviour, specifically in filtering out or learning to ignore irrelevant environmental stimuli, is successful in explaining all available data and direct tests of the lesioned rats' attentional capacity serve to confirm many of the predictions of an attentional theory of the dorsal bundle extinction effect.
Geometries and applications of active fiber bundles
Giglmayr, Josef
2001-10-01
Active fiber bundles (FBs) are aimed to model photonic switching and processing in 3-D without the restrictions of the photonic technology. The 2-D photonic architectures are assumed to be implemented by networks of directional couplers (DCs) and Mach-Zehnder interferometers (MZIs), respectively. For the implementation several crucial problems are expected: (1) proper operation of the spatial couplers/switches (nonblocking interconnections) and (2) coupling in the interstage interconnection section mainly caused by parallel and crossing fibers/waveguides (WGs). For the design of proper operating switches (refinement of couplers) the application of decoupling concepts of modern control theory is proposed. The final goal is to translate the refined couplers into integrated photonic architectures rather than into additional lightwave circuits (LWCs) which simply would increase the coupling. The decoupling concepts are reviewed. The paper is an attempt to prepare for applying well-known system engineering concepts to the upcoming technology of photonics.
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...
The behaviour of Phenix fuel pin bundle under irradiation
International Nuclear Information System (INIS)
An entire Phenix sub-assembly has been mounted and sectioned after irradiation. The examination of cross-sections revealed the effects of mechanical interaction in the bundle (ovalisations and contacts between clads). According to analysis of the sodium channels, cooling of the pin bundle remained uniform. (author)
Extendability of parallel sections in vector bundles
Kirschner, Tim
2016-01-01
I address the following question: Given a differentiable manifold M, what are the open subsets U of M such that, for all vector bundles E over M and all linear connections ∇ on E, any ∇-parallel section in E defined on U extends to a ∇-parallel section in E defined on M? For simply connected manifolds M (among others) I describe the entirety of all such sets U which are, in addition, the complement of a C1 submanifold, boundary allowed, of M. This delivers a partial positive answer to a problem posed by Antonio J. Di Scala and Gianni Manno (2014). Furthermore, in case M is an open submanifold of Rn, n ≥ 2, I prove that the complement of U in M, not required to be a submanifold now, can have arbitrarily large n-dimensional Lebesgue measure.
Birefringence of single and bundled microtubules.
Oldenbourg, R; Salmon, E D; Tran, P T
1998-01-01
We have measured the birefringence of microtubules (MTs) and of MT-based macromolecular assemblies in vitro and in living cells by using the new Pol-Scope. A single microtubule in aqueous suspension and imaged with a numerical aperture of 1.4 had a peak retardance of 0.07 nm. The peak retardance of a small bundle increased linearly with the number of MTs in the bundle. Axonemes (prepared from sea urchin sperm) had a peak retardance 20 times higher than that of single MTs, in accordance with the nine doublets and two singlets arrangement of parallel MTs in the axoneme. Measured filament retardance decreased when the filament was defocused or the numerical aperture of the imaging system was decreased. However, the retardance "area," which we defined as the image retardance integrated along a line perpendicular to the filament axis, proved to be independent of focus and of numerical aperture. These results are in good agreement with a theory that we developed for measuring retardances with imaging optics. Our theoretical concept is based on Wiener's theory of mixed dielectrics, which is well established for nonimaging applications. We extend its use to imaging systems by considering the coherence region defined by the optical set-up. Light scattered from within that region interferes coherently in the image point. The presence of a filament in the coherence region leads to a polarization dependent scattering cross section and to a finite retardance measured in the image point. Similar to resolution measurements, the linear dimension of the coherence region for retardance measurements is on the order lambda/(2 NA), where lambda is the wavelength of light and NA is the numerical aperture of the illumination and imaging lenses. PMID:9449366
Habibi, Somayeh
2011-01-01
Let $G$ be a reductive algebraic group over a perfect field $k$ and $\\mathcal{G}$ a $G$-bundle over a scheme $X/k$. The main aim of this article is to study the motive associated with $\\mathcal{G}$, inside the Veovodsky Motivic categories. We consider the case that $\\charakt k=0$ (resp. $\\charakt k\\geq 0$), the motive associated to $X$ is geometrically mixed Tate (resp. geometrically cellular) and $\\mathcal{G}$ is locally trivial for the Zariski (resp. \\'etale) topology on $X$ and show that the motive of $\\mathcal{G}$ is a geometrically mixed Tate motive. Moreover for a general $X$ we construct a filtration on the motive associated to $\\mathcal{G}$ in terms of weight polytopes. Along the way we give some applications and examples.
Josef Steindl: An Economist of His Times
Directory of Open Access Journals (Sweden)
Nina Shapiro
2012-09-01
Full Text Available This paper discusses the life and work of Josef Steindl. It examines the development of his thought from his early writings on firm size and industrial concentration to his late work on the post-war problems of capitalist economies. Special attention is given to his seminal work on the Great Depression: Maturity and Stagnation in American Capitalism (1952. His work, which covered all the critical economic developments of the 20th century, greatly illuminated the problems of his times, and is as relevant to the problems of our own as it was to his.
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.
Introduction to the theory of fiber bundles and connections I
International Nuclear Information System (INIS)
In lectures 1 and 2 we discuss basic concepts of topology and differential geometry: definition of a topological space and of Hausdorff, compact, connected and paracompact spaces; topological groups and actions of groups on spaces; differentiable manifolds, tangent vectors and 1 forms; partitions of unity and Lie groups. In lecture 3 we present the concept of a fiber bundle and discuss vector bundles and principal bundles. The concept of a connection on a smooth vector bundle is defined in lecture 4, together with the associated concepts of curvature and parallel transport; as an illustration we present the Levi-Civita connection on a Riemannian manifold. Finally, in lecture 5 we define connections on principal bundles and present examples with the Lie groups U(1) and SU(2). For reasons of space the present article only includes lectures 1, 2 and 3. Lectures 4 and 5 will be published in a forthcoming paper. (Author)
Phase Space Reduction of Star Products on Cotangent Bundles.
N. Kowalzig; N. Neumaier; M. Pflaum
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 $\\omega_{B
Helical twist controls the thickness of F-actin bundles
Claessens, M.M.A.E.; Semmrich, C.; Ramos, L.; Bausch, A.R.
2008-01-01
In the presence of condensing agents such as nonadsorbing polymer, multivalent counter ions, and specific bundling proteins, chiral biopolymers typically form bundles with a finite thickness, rather than phase-separating into a polymer-rich phase. Although short-range repulsive interactions or geome
The 2-Hilbert Space of a Prequantum Bundle Gerbe
Bunk, Severin; Szabo, Richard J
2016-01-01
We construct a prequantum 2-Hilbert space for any line bundle gerbe whose Dixmier-Douady class is torsion. Analogously to usual prequantisation, 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 prequantisation. 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 prequantisation in this setting, including its dimensional reductio...
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.
Voltage- and calcium-dependent motility of saccular hair bundles
Quiñones, Patricia M.; Meenderink, Sebastiaan W. F.; Bozovic, Dolores
2015-12-01
Active bundle motility, which is hypothesized to supply feedback for mechanical amplification of signals, is thought to enhance sensitivity and sharpen tuning in vestibular and auditory organs. To study active hair bundle motility, we combined high-speed camera recordings of bullfrog sacculi, which were mounted in a two-compartment chamber, and voltage-clamp of the hair cell membrane potential. Using this paradigm, we measured three types of bundle motions: 1) spontaneous oscillations which can be analyzed to measure the physiological operating range of the transduction channel; 2) a sustained quasi-static movement of the bundle that depends on membrane potential; and 3) a fast, transient and asymmetric movement that resets the bundle position and depends on changes in the membrane potential. These data support a role for both calcium and voltage in the transduction-channel function.
CHF Enhancement of Advanced 37-Element Fuel Bundles
Directory of Open Access Journals (Sweden)
Joo Hwan Park
2015-01-01
Full Text Available A standard 37-element fuel bundle (37S fuel bundle has been used in commercial CANDU reactors for over 40 years as a reference fuel bundle. Most CHF of a 37S fuel bundle have occurred at the elements arranged in the inner pitch circle for high flows and at the elements arranged in the outer pitch circle for low flows. It should be noted that a 37S fuel bundle has a relatively small flow area and high flow resistance at the peripheral subchannels of its center element compared to the other subchannels. The configuration of a fuel bundle is one of the important factors affecting the local CHF occurrence. Considering the CHF characteristics of a 37S fuel bundle in terms of CHF enhancement, there can be two approaches to enlarge the flow areas of the peripheral subchannels of a center element in order to enhance CHF of a 37S fuel bundle. To increase the center subchannel areas, one approach is the reduction of the diameter of a center element, and the other is an increase of the inner pitch circle. The former can increase the total flow area of a fuel bundle and redistributes the power density of all fuel elements as well as the CHF. On the other hand, the latter can reduce the gap between the elements located in the middle and inner pitch circles owing to the increasing inner pitch circle. This can also affect the enthalpy redistribution of the fuel bundle and finally enhance CHF or dry-out power. In this study, the above two approaches, which are proposed to enlarge the flow areas of the center subchannels, were considered to investigate the impact of the flow area changes of the center subchannels on the CHF enhancement as well as the thermal characteristics by applying a subchannel analysis method.
Thermal Characteristics of Tube Bundles in Ultra-Supercritical Boilers
Directory of Open Access Journals (Sweden)
Seok Min Choi
2016-09-01
Full Text Available In this study, flow and thermal characteristics of tube bundles in ultra-supercritical boilers were analyzed. The local heat transfer around the tube bundles was measured to predict the local temperature distribution and vulnerable positions of the superheated tube bundles. The maximally superheated tube bundles were simulated in the laboratory and local heat transfer was measured by using the naphthalene sublimation method. The experiment was conducted on three lines of tube bundles, all with in-line arrangements. Each line consist of six tubes. The distance in the streamwise direction (Sx/∅ was 1.99 and that in the spanwise direction (Sz/∅ was 5.45. The Reynolds number varied from 5000 to 30,000, which covers a range of different operating conditions. Thermal and stress analyses were conducted numerically, based on the experimental data. The results showed that the flow characteristic changes the local heat transfer of the tube bundles. The flow impinged on the stagnation point of Tube 1 and reattached at 60° of Tube 2. The high heat transfer occurred at those positions of the tube bundles. The temperature and stress distributions on the surface of each tube bundle also varied. The reattachment point on Tube 2 had the highest heat transfer and temperature distribution. That position on Tube 2 was subjected to the highest stress due to the large temperature gradient. This result indicates that Tube 2 of the ultra-supercritical (USC boiler is the weakest of the tube bundles, changing the pitch of the streamwise direction of Tube 2 is one method to reduce the highest stress in superheater tube bundles in the USC boiler.
Directory of Open Access Journals (Sweden)
Johan Kommers
2014-03-01
Full Text Available The founder of the Keswick Convention (KC once was asked to put in a sentence that has brought such a joy into his life and made the name of Keswick fragrant over the whole world. The answer was in the words of the Psalm 16:8, ‘I have set the Lord always before me’. Keswick theology, emphasising sanctification, arose within the concept of the holiness tradition in America with the higher Christian life movement in England during the second part of the 19th century. The merging of several theological traditions formed a way of expressing oneself and a way of life, which was determined as typical ‘Keswickian’. It also found expression in other theological (conservative movements, in new founded institutions and gave a boost to missionary enterprise. The language and the teaching of Keswick until today clarify the pattern of evangelical piety of the 20th century.
Effect of Reynolds number and bundle geometry on the turbulent flow in tight lattice bundle
International Nuclear Information System (INIS)
The flow structure in tight lattice is still of great interest to nuclear industry. The accurate prediction of flow parameter in subchannels of tight lattice is likable. Unsteady Reynolds Averaged Navier Stokes (URANS) is a promising approach to achieve this goal. The implementation of URANS (Unsteady Reynolds Averaged Navier Stokes) approach will be validated by comparing computational results with the experimental data of Krauss (1998). In this paper, the turbulent flow with different Reynolds number (5000~215000) and different P/D(1.005~1.2) are simulated with CFD code CFX12.The effects of the Reynolds number and the bundle geometry(P/D) on wall shear stress, turbulent kinetic energy, turbulent mixing and large scale coherent structure in tight lattice are analyzed in details. It is hoped that the present work will contribute to the understanding of these important flow phenomena and facilitate the prediction and design of rod bundles. (author)
Delisle, Dennis R
2013-01-01
With passage of the Affordable Care Act, the ever-evolving landscape of health care braces for another shift in the reimbursement paradigm. As health care costs continue to rise, providers are pressed to deliver efficient, high-quality care at flat to minimally increasing rates. Inherent systemwide inefficiencies between payers and providers at various clinical settings pose a daunting task for enhancing collaboration and care coordination. A change from Medicare's fee-for-service reimbursement model to bundled payments offers one avenue for resolution. Pilots using such payment models have realized varying degrees of success, leading to the development and upcoming implementation of a bundled payment initiative led by the Center for Medicare and Medicaid Innovation. Delivery integration is critical to ensure high-quality care at affordable costs across the system. Providers and payers able to adapt to the newly proposed models of payment will benefit from achieving cost reductions and improved patient outcomes and realize a competitive advantage.
Systematic evaluation of bundled SPC water for biomolecular simulations.
Gopal, Srinivasa M; Kuhn, Alexander B; Schäfer, Lars V
2015-04-01
In bundled SPC water models, the relative motion of groups of four water molecules is restrained by distance-dependent potentials. Bundled SPC models have been used in hybrid all-atom/coarse-grained (AA/CG) multiscale simulations, since they enable to couple atomistic SPC water with supra-molecular CG water models that effectively represent more than a single water molecule. In the present work, we systematically validated and critically tested bundled SPC water models as solvent for biomolecular simulations. To that aim, we investigated both thermodynamic and structural properties of various biomolecular systems through molecular dynamics (MD) simulations. Potentials of mean force of dimerization of pairs of amino acid side chains as well as hydration free energies of single side chains obtained with bundled SPC and standard (unrestrained) SPC water agree closely with each other and with experimental data. Decomposition of the hydration free energies into enthalpic and entropic contributions reveals that in bundled SPC, this favorable agreement of the free energies is due to a larger degree of error compensation between hydration enthalpy and entropy. The Ramachandran maps of Ala3, Ala5, and Ala7 peptides are similar in bundled and unrestrained SPC, whereas for the (GS)2 peptide, bundled water leads to a slight overpopulation of extended conformations. Analysis of the end-to-end distance autocorrelation times of the Ala5 and (GS)2 peptides shows that sampling in more viscous bundled SPC water is about two times slower. Pronounced differences between the water models were found for the structure of a coiled-coil dimer, which is instable in bundled SPC but not in standard SPC. In addition, the hydration of the active site of the serine protease α-chymotrypsin depends on the water model. Bundled SPC leads to an increased hydration of the active site region, more hydrogen bonds between water and catalytic triad residues, and a significantly slower exchange of water
Bondage Numbers of C4 Bundles over a Cycle Cn
Directory of Open Access Journals (Sweden)
Moo Young Sohn
2013-01-01
Full Text Available Graph bundles generalize the notion of covering graphs and graph products. Graph bundles have been applied in computer architecture and communication networks. The bondage number is an important parameter for measuring the vulnerability and stability of the network domination under link failure. The bondage number b(G of a graph G is the minimum number of edges whose removal enlarges the domination number. In this paper, we show that the bondage number of every C4 bundles over a cycle Cn (n≥4 is equal to 4.
Shatz, L F
2000-03-01
The relationship between size and shape of the hair bundle of a hair cell in the inner ear and its sensitivity at asymptotically high and low frequencies was determined, thereby extending the results of an analysis of hair bundle hydrodynamics in two dimensions (Freeman and Weiss, 1990. Hydrodynamic analysis of a two-dimensional model for micromechanical resonance of free-standing hair bundles. Hear. Res. 48, 37-68) to three dimensions. A hemispheroid was used to represent the hair bundle. The hemispheroid had a number of advantages: it could represent shapes that range from thin, pencil-like shapes, to wide, flat, disk-like shapes. Also analytic methods could be used in the high frequency range to obtain an exact solution to the equations of motion. In the low frequency range, where an approximate solution was found using boundary element methods, the sensitivity of the responses of hair cells was mainly proportional to the cube of the heights of their hair bundles, and at high frequencies, the sensitivity of the hair cells was mainly proportional to the inverse of their heights. An excellent match was obtained between measurements of sensitivity curves in the basillar papilla of the alligator and bobtail lizards and the model's predictions. These results also suggest why hair bundles of hair cells in vestibular organs which are sensitive to low frequencies have ranges of heights that are an order of magnitude larger than the range of heights of hair bundles of hair cells found in auditory organs.
The Geometry of Tangent Bundles: Canonical Vector Fields
Directory of Open Access Journals (Sweden)
Tongzhu Li
2013-01-01
Full Text Available A canonical vector field on the tangent bundle is a vector field defined by an invariant coordinate construction. In this paper, a complete classification of canonical vector fields on tangent bundles, depending on vector fields defined on their bases, is obtained. It is shown that every canonical vector field is a linear combination with constant coefficients of three vector fields: the variational vector field (canonical lift, the Liouville vector field, and the vertical lift of a vector field on the base of the tangent bundle.
Thermomagnetic Siphoning on a Bundle of Current-Carrying Wires
Boulware, Jeffrey C.; Jensen, Scott
2010-01-01
Using COMSOL Multiphysics 3.5a, thermomagnetic siphoning (TMS) was shown to be a sufficient manner of regulating the temperature of a bundle of current-carrying wires wrapped with a magnetorheological fluid (MRF) jacket. As the bundle heated up, cooler MRF on the outside of the jacket was drawn towards the center due to Curie’s Law and the induced magnetic field. The process convected heat from the bundle as the MRF warmed up and was pushed out towards an isothermal jacket wall. Assuming an o...
Deformation Quantization of Principal Fibre Bundles and Classical Gauge Theories
Wei\\ss, Stefan
2010-01-01
In this dissertation the notion of deformation quantization of principal fibre bundles is established and investigated in order to find a geometric formulation of classical gauge theories on noncommutative space-times. As a generalization, the notion of deformation quantization of surjective submersions is also discussed. It is shown that deformation quantizations of surjective submersions and principal fibre bundles always exist and are unique up to equivalence. These statements concerning complex-valued functions are moreover formulated and proved for sections of arbitrary vector bundles over the total space, in particular equivariant vector bundles. The commutants of the deformed right module structures within the differential operators, playing an inportant role with regard to the infinitesimal gauge transformations, are computed explicitly in each case. Depending on the choice of specific covariant derivatives and connections the commutants are isomorphic to the formal power series of the respective vert...
Mechanical Models of Microtubule Bundle Collapse in Alzheimer's Disease
Sendek, Austin; Singh, Rajiv; Cox, Daniel
2013-03-01
Amyloid-beta aggregates initiate Alzheimer's disease, and downstream trigger degradation of tau proteins that act as microtubule bundle stabilizers and mechanical spacers. Currently it is unclear which of tau cutting by proteases, tau phosphorylation, or tau aggregation are responsible for cytoskeleton degradation., We construct a percolation simulation of the microtubule bundle using a molecular spring model for the taus and including depletion force attraction between microtubules and membrane/actin cytoskeletal surface tension. The simulation uses a fictive molecular dynamics to model the motion of the individual microtubules within the bundle as a result of random tau removal, and calculates the elastic modulus of the bundle as the tau concentration falls. We link the tau removal steps to kinetic tau steps in various models of tau degradation. Supported by US NSF Grant DMR 1207624
Steric effects induce geometric remodeling of actin bundles in filopodia
Dobramysl, Ulrich; Erban, Radek
2016-01-01
Filopodia are ubiquitous fingerlike protrusions, spawned by many eukaryotic cells, to probe and interact with their environments. Polymerization dynamics of actin filaments, comprising the structural core of filopodia, largely determine their instantaneous lengths and overall lifetimes. The polymerization reactions at the filopodial tip require transport of G-actin, which enter the filopodial tube from the filopodial base and diffuse toward the filament barbed ends near the tip. Actin filaments are mechanically coupled into a tight bundle by cross-linker proteins. Interestingly, many of these proteins are relatively short, restricting the free diffusion of cytosolic G-actin throughout the bundle and, in particular, its penetration into the bundle core. To investigate the effect of steric restrictions on G-actin diffusion by the porous structure of filopodial actin filament bundle, we used a particle-based stochastic simulation approach. We discovered that excluded volume interactions result in partial and the...
Bondage Numbers of C4 Bundles over a Cycle Cn
Moo Young Sohn; Fu-Tao Hu; Jaeun Lee
2013-01-01
Graph bundles generalize the notion of covering graphs and graph products. Graph bundles have been applied in computer architecture and communication networks. The bondage number is an important parameter for measuring the vulnerability and stability of the network domination under link failure. The bondage number $b\\left(G\\right)$ of a graph $G$ is the minimum number of edges whose removal enlarges the domination number. In this paper, we show that the bondage number of every ${C}_{4}$ bu...
On exact triangles consisting of stable vector bundles on tori
Kobayashi, Kazushi
2016-01-01
In this paper, we consider the exact triangles consisting of stable holomorphic vector bundles on one-dimensional complex tori, and discuss their relations with the corresponding Fukaya category via the homological mirror symmetry.
Bundles of Norms About Teen Sex and Pregnancy.
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. PMID:25387911
Bundles of Norms About Teen Sex and Pregnancy.
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.
Simplified modeling of EM field coupling to complex cable bundles
Schetelig, B.; J. Keghie; Kanyou Nana, R.; Fichte, L.-O.; S. Potthast; Dickmann, S.
2010-01-01
In this contribution, the procedure "Equivalent Cable Bundle Method" is used for the simplification of large cable bundles, and it is extended to the application on differential signal lines. The main focus is on the reduction of twisted-pair cables. Furthermore, the process presented here allows to take into account cables with wires that are situated quite close to each other. The procedure is based on a new approach to calculate the geometry of the simplified cable and us...
A man of his country and his time: Jewish influences on Lev Semionovich Vygotsky's world view.
Kotik-Friedgut, Bella; Friedgut, Theodore H
2008-02-01
Lev Semionovich Vygotsky created the cultural-historical school of psychology, yet all too few of those writing about his work take into account the family, education, and cultural tradition from which he came. The authors contend that the Jewish nature of these elements was of some importance in forming his personality and his consciousness. The 1st part of the article traces his early upbringing, describes the Jewishness of his environment, notes 3 instances in which his "otherness" was imprinted on his consciousness, and points to the sources of his determination to forge a harmonious synthesis with his environment. The 2nd part examines his writings, both earlier journalistic and mature psychological, and points to evidence of the influence of his Jewish upbringing and environment on his work. PMID:19048956
Photochemical properties of mesophyll and bundle sheath chloroplasts of maize.
Bazzaz, M B; Govindjee
1973-09-01
Several photochemical and spectral properties of maize (Zea mays) bundle sheath and mesophyll chloroplasts are reported that provide a better understanding of the photosynthetic apparatus of C(4) plants. The difference absorption spectrum at 298 K and the fluorescence excitation and emission spectra of chlorophyll at 298 K and 77 K provide new information on the different forms of chlorophyll a in bundle sheath and mesophyll chloroplasts: the former contain, relative to short wavelength chlorophyll a forms, more long wavelength chlorophyll a form (e.g. chlorophyll a 693 and chlorophyll a 705) and less chlorophyll b than the latter. The degree of polarization of chlorophyll a fluorescence is 6% in bundle sheath and 4% in mesophyll chloroplasts. This result is consistent with the presence of relatively high amounts of oriented long wavelength forms of chlorophyll a in bundle sheath compared to mesophyll chloroplasts. The relative yield of variable, with respect to constant, chorophyll a fluorescence in mesophyll chloroplasts is more than twice that in bundle sheath chloroplast. Furthermore, the relative yield of total chlorophyll a fluorescence is 40% lower in bundle sheath compared to that in mesophyll chloroplasts. This is in agreement with the presence of the higher ratio of the weakly fluorescent pigment system I to pigment system II in bundle sheath than in mesophyll chloroplast. The efficiency of energy transfer from chlorophyll b and carotenoids to chlorophyll a are calculated to be 100 and 50%, respectively, in both types of chloroplasts. Fluorescence quenching of atebrin, reflecting high energy state of chloroplasts, is 10 times higher in mesophyll chloroplasts than in bundle sheath chloroplasts during noncyclic electron flow but is equal during cyclic flow. The entire electron transport chain is shown to be present in both types of chloroplasts, as inferred from the antagonistic effect of red (650 nm) and far red (710 nm) lights on the absorbance changes at
How Buyers Evaluate Product Bundles: A Model of Anchoring and Adjustment.
Yadav, Manjit S
1994-01-01
Bundling, the joint offering of two or more items, is a common selling strategy, yet little research has been conducted on buyers' evaluation of bundle offers. We developed and tested a model of bundle evaluation in which the buyers anchored their evaluation on the item perceived as most important and then made adjustments on the basis of their evaluations of the remaining bundle items. The results of two computerized laboratory experiments suggested that people tend to examine bundle items i...
Thermal hydraulics of rod bundles: The effect of eccentricity
Energy Technology Data Exchange (ETDEWEB)
Chauhan, Amit K., E-mail: amit_fmlab@yahoo.co.in [Fluid Mechanics Laboratory, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai 600036 (India); Prasad, B.V.S.S.S., E-mail: prasad@iitm.ac.in [Thermal Turbomachines Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Patnaik, B.S.V., E-mail: bsvp@iitm.ac.in [Fluid Mechanics Laboratory, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai 600036 (India)
2013-10-15
Highlights: • Present CFD investigation explores, whole bundle eccentricity for the first time. • Fluid flow and thermal characteristics in various subchannels are analyzed. • Mass flux distribution is particularly analyzed to study eccentricity effect. • Higher eccentricity resulted in a shoot up in rod surface temperature distribution. • Both tangential and radial flow in rod bundles has resulted due to eccentricity. -- Abstract: The effect of eccentricity on the fluid flow and heat transfer through a 19-rod bundle is numerically carried out. When the whole bundle shifts downwards with respect to the outer (pressure) tube, flow redistribution happens. This in turn is responsible for changes in mass flux, pressure and differential flow development in various subchannels. The heat flux imposed on the surface of the fuel rods and the mass flux through the subchannels determines the coolant outlet temperatures. The simulations are performed for a coolant flow Reynolds number of 4 × 10{sup 5}. For an eccentricity value of 0.7, the mass flux in the bottom most subchannel (l) was found to decrease by 10%, while the surface temperature of the fuel rod in the vicinity of this subchannel increased by 250% at the outlet section. Parameters of engineering interest including skin friction coefficient, Nusselt number, etc., have been systematically explored to study the effect of eccentricity on the rod bundle.
Hagg, Heather (Woodward); El-Harit, Jamie; Vanni, Chris; Scott, Penny
2007-01-01
Within healthcare, clinical practice bundles have been used to implement standardized, nursing driven protocols resulting in standardized patient care and improved patient outcomes. Examples of these types of bundles include clinical practices shown through evidence based medicine to reduce occurrences of Ventilator Associated Pneumonia – VAP bundle; those shown to reduce the occurrences of central line infections – CL bundle; and those shown to significantly improve the outcomes of patients...
Betti numbers of graded modules and cohomology of vector bundles
Eisenbud, David; Schreyer, Frank-Olaf
2009-07-01
In the remarkable paper Graded Betti numbers of Cohen-Macaulay modules and the multiplicity conjecture, Mats Boij and Jonas Soederberg conjectured that the Betti table of a Cohen-Macaulay module over a polynomial ring is a positive linear combination of Betti tables of modules with pure resolutions. We prove a strengthened form of their conjectures. Applications include a proof of the Multiplicity Conjecture of Huneke and Srinivasan and a proof of the convexity of a fan naturally associated to the Young lattice. With the same tools we show that the cohomology table of any vector bundle on projective space is a positive rational linear combination of the cohomology tables of what we call supernatural vector bundles. Using this result we give new bounds on the slope of a vector bundle in terms of its cohomology.
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
@@ If you want to know the mind of Alan Greenspan, you might start with this: Before he entered public life in the 1970s, all his top deputies at his flourishing economic consulting firm were women. "It just made great business sense,"he writes with the unexpectedly sunny wonkiness that pervades much of his memoir, The Age of Turbulence. "I valued men and women equally, and found that because other employers did not,good women economists were less expensive than men."
Failure process of a bundle of plastic fibers
F. Raischel; Kun, F; Herrmann, H. J.
2006-01-01
We present an extension of fiber bundle models considering that failed fibers still carry a fraction $0 \\leq \\alpha \\leq 1$ of their failure load. The value of $\\alpha$ interpolates between the perfectly brittle failure $(\\alpha = 0)$ and perfectly plastic behavior $(\\alpha=1)$ of fibers. We show that the finite load bearing capacity of broken fibers has a substantial effect on the failure process of the bundle. In the case of global load sharing it is found that for $\\alpha \\to 1$ the macros...
Börlin, Niclas; Grussenmeyer, Pierre
2016-06-01
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.
Variable recruitment in bundles of miniature pneumatic artificial muscles.
DeLaHunt, Sylvie A; Pillsbury, Thomas E; Wereley, Norman M
2016-01-01
The natural compliance and force generation properties of pneumatic artificial muscles (PAMs) allow them to operate like human muscles in anthropomorphic robotic manipulators. Traditionally, manipulators use a single PAM or multiple PAMs actuated in unison in place of a human muscle. However, these standard manipulators can experience significant efficiency losses when operated outside their target performance ranges at low actuation pressures. This study considers the application of a variable recruitment control strategy to a parallel bundle of miniature PAMs as an attempt to mimic the selective recruitment of motor units in a human muscle. Bundles of miniature PAMs are experimentally characterized, their actuation behavior is modeled, and the efficiency gains and losses associated with the application of a variable recruitment control strategy are assessed. This bio-inspired control strategy allows muscle bundles to operate the fewest miniature PAMs necessary to achieve a desired performance objective, improving the muscle bundle's operating efficiency over larger ranges of force generation and displacement. The study also highlights the need for improved PAM fabrication techniques to facilitate the production of identical miniature PAMs for inclusion in muscle bundles. PMID:27623216
Location of test bundle instrumentation and anticipated experimental values for the CFTL AG-1 bundle
International Nuclear Information System (INIS)
The placement of instrumentation within the Core Flow Test Loop (CFTL) AG-1 test section to meet the following objectives is described. The objectives are threefold: (1) to provide values for the evaluation of the performance of the test section, (2) to compare the experimental data with value determined by pretest calulations to indicate the approach to conditions that can lead to a bundle failure, and (3) to acquire data during testing that will form a data base for subsequent use in the verification of computational procedures used in the licensing of the Gas-Cooled Fast Reactor. Anticipated values for the various instruments have been determined using the computational procedure SAGAPO modified for the AG-1 geometry. These results are used as the basis for the specification of differential pressure cells and the range of readings anticipated from the thermocouples. Part of the results for the full-flow, full-power case is presented
Experimental study for convective heat transfer of staged tube bundles
International Nuclear Information System (INIS)
The lack of potable water is one of the most serious problems the world is facing at present. SMART which is a 330 MWt advanced integral PWR, was developed by the KAERI for electricity generation and seawater desalination. SMART adopted a passive system to enhance its safety. The passive system can passively remove a decay heat from a reactor core to an emergency cooldown tank through the heat exchanger. Tube bundles of the heat exchanger, which is submerged in an emergency cooldown tank, transfer heat to an emergency cooldown tank by natural circulation. Heat transfer tests for the upward straight tube bundle were performed to confirm the capability of the SMART design under natural circulation conditions. The heat transfer at the tube bundle was affected by the fluid temperature in the emergency cooldown tank and the radial location of tube bundle. However, it had nearly the same value at the inlet region regardless of the tube location. The average heat transfer at the tube bundle was slightly higher than that at the single tube. (author)
Multi-scale strain-stiffening of semiflexible bundle networks
Piechocka, I K; Broedersz, C P; Kurniawan, N A; MacKintosh, F C; Koenderink, G H
2015-01-01
Bundles of polymer filaments are responsible for the rich and unique mechanical behaviors of many biomaterials, including cells and extracellular matrices. In fibrin biopolymers, whose nonlinear elastic properties are crucial for normal blood clotting, protofibrils self-assemble and bundle to form networks of semiflexible fibers. Here we show that the extraordinary strain-stiffening response of fibrin networks is a direct reflection of the hierarchical architecture of the fibrin fibers. We measure the rheology of networks of unbundled protofibrils and find excellent agreement with an affine model of extensible wormlike polymers. By direct comparison with these data, we show that physiological fibrin networks composed of thick fibers can be modeled as networks of tight protofibril bundles. We demonstrate that the tightness of coupling between protofibrils in the fibers can be tuned by the degree of enzymatic intermolecular crosslinking by the coagulation Factor XIII. Furthermore, at high stress, the protofibri...
Magnetic Propulsion of Microswimmers with DNA-Based Flagellar Bundles.
Maier, Alexander M; Weig, Cornelius; Oswald, Peter; Frey, Erwin; Fischer, Peer; Liedl, Tim
2016-02-10
We show that DNA-based self-assembly can serve as a general and flexible tool to construct artificial flagella of several micrometers in length and only tens of nanometers in diameter. By attaching the DNA flagella to biocompatible magnetic microparticles, we provide a proof of concept demonstration of hybrid structures that, when rotated in an external magnetic field, propel by means of a flagellar bundle, similar to self-propelling peritrichous bacteria. Our theoretical analysis predicts that flagellar bundles that possess a length-dependent bending stiffness should exhibit a superior swimming speed compared to swimmers with a single appendage. The DNA self-assembly method permits the realization of these improved flagellar bundles in good agreement with our quantitative model. DNA flagella with well-controlled shape could fundamentally increase the functionality of fully biocompatible nanorobots and extend the scope and complexity of active materials. PMID:26821214
Magnetic Propulsion of Microswimmers with DNA-Based Flagellar Bundles.
Maier, Alexander M; Weig, Cornelius; Oswald, Peter; Frey, Erwin; Fischer, Peer; Liedl, Tim
2016-02-10
We show that DNA-based self-assembly can serve as a general and flexible tool to construct artificial flagella of several micrometers in length and only tens of nanometers in diameter. By attaching the DNA flagella to biocompatible magnetic microparticles, we provide a proof of concept demonstration of hybrid structures that, when rotated in an external magnetic field, propel by means of a flagellar bundle, similar to self-propelling peritrichous bacteria. Our theoretical analysis predicts that flagellar bundles that possess a length-dependent bending stiffness should exhibit a superior swimming speed compared to swimmers with a single appendage. The DNA self-assembly method permits the realization of these improved flagellar bundles in good agreement with our quantitative model. DNA flagella with well-controlled shape could fundamentally increase the functionality of fully biocompatible nanorobots and extend the scope and complexity of active materials.
A class of Poisson Nijenhuis structures on a tangent bundle
Sarlet, W.; Vermeire, F.
2004-06-01
Equipping the tangent bundle TQ of a manifold with a symplectic form coming from a regular Lagrangian L, we explore how to obtain a Poisson-Nijenhuis structure from a given type (1, 1) tensor field J on Q. It is argued that the complete lift Jc of J is not the natural candidate for a Nijenhuis tensor on TQ, but plays a crucial role in the construction of a different tensor R, which appears to be the pullback under the Legendre transform of the lift of J to T*Q. We show how this tangent bundle view brings new insights and is capable also of producing all important results which are known from previous studies on the cotangent bundle, in the case when Q is equipped with a Riemannian metric. The present approach further paves the way for future generalizations.
Symposium on Singularities, Representation of Algebras, and Vector Bundles
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.
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.
Simulation of bundle test Quench-12 with integral code MELCOR
International Nuclear Information System (INIS)
The past NRI analyses cover the Quench-01, Quench-03 and Quench-06 with version MELCOR 1.8.5 (including reflood model), and Quench-01 and Quench-11 tests with the latest version MELCOR 1.8.6. The Quench-12 test is specific, because it has different bundle configuration related to the VVER bundle configuration with hexagonal grid of pins and also used E110 cladding material. Specificity of Quench-12 test is also in the used material of fuel rod cladding - E110. The test specificities are a reason for the highest concern, because the VVER reactors are operated in the Czech Republic. The new input model was developed with the taking into account all experience from previous simulations of the Quench bundle tests. The recent version MELCOR 1.8.6 YU2911 was used for the simulation with slightly modified ELHEAT package. Sensitivity studies on input parameters and oxidation kinetics were performed. (author)
Stable bundles of rank 2 with 4 sections
Grzegorczyk, I; Newstead, P E
2010-01-01
This paper contains results on stable bundles of rank $2$ with space of sections of dimension $4$ on a smooth irreducible projective algebraic curve $C$. There is a known lower bound on the degree for the existence of such bundles; the main result of the paper is a geometric criterion for this bound to be attained. For a general curve $C$ of genus $10$, we show that the bound cannot be attained, but that there exist Petri curves of this genus for which the bound is sharp. We interpret the main results for various curves and in terms of Clifford indices and coherent systems.
Stable bundles of rank 2 with 4 sections
Grzegorczyk, I.; Mercat, V.; Newstead, P. E.
2010-01-01
This paper contains results on stable bundles of rank 2 with space of sections of dimension 4 on a smooth irreducible projective algebraic curve $C$. There is a known lower bound on the degree for the existence of such bundles; the main result of the paper is a geometric criterion for this bound to be attained. For a general curve $C$ of genus 10, we show that the bound cannot be attained, but that there exist Petri curves of this genus for which the bound is sharp. We interpret the main resu...
Normal Bundle of Rational Curves and Waring Decomposition
Bernardi, Alessandro
2012-01-01
The problem to determine the splitting of the normal bundle of rational curves has been considered in the 80s in a series of papers by Ghione and Sacchiero and in another series by Eisenbud and Van de Ven in the case of rational space curves. With our approach we are able to obtain results for curves enbedded in $\\bbP^m$ for $m\\geq 3$ we find an interesting interplay between the Waring decomposition and the splitting of the normal bundle.
Dialytic Separation of Bundled, Functionalized Carbon Nanotubes from Carbonaceous Impurities
Directory of Open Access Journals (Sweden)
J. Justin Mulvey
2014-11-01
Full Text Available Separating functionalized single-wall carbon nanotubes (SWCNTs from functionalized amorphous carbon is challenging, due to their polydispersity and similar physicochemical properties. We describe a single-step, dialytic separation method that takes advantage of the ability of heavily functionalized SWCNTs to bundle in a polar environment while maintaining their solubility. Experiments on functionalized SWCNTs were compared with functionalized, C60 fullerenes (buckyballs to probe the general applicability of the method and further characterize the bundling process. This approach may simultaneously be used to purify a functionalization reaction mixture of unreacted small molecules and of residual solvents, such as dimethylformamide.
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...
ASSERT and COBRA predictions of flow distribution in vertical bundles
International Nuclear Information System (INIS)
COBRA and ASSERT are subchannel codes which compute flow and enthalpy distributions in rod bundles. COBRA is a well known code, ASSERT is under development at CRNL. This paper gives a comparison of the two codes with boiling experiments in vertical seven rod bundles. ASSERT predictions of the void distribution are shown to be in good agreement with reported experimental results, while COBRA predictions are unsatisfactory. The mixing models in both COBRA and ASSERT are briefly discussed. The reasons for the failure of COBRA-IV and the success of ASSERT in simulating the experiments are highlighted
Reaction–diffusion model of hair-bundle morphogenesis
Jacobo, Adrian; Hudspeth, A. J.
2014-01-01
Our senses of hearing and balance rest upon the activity of hair cells, the ear’s sensory receptors. Each hair cell detects mechanical stimuli with its hair bundle, an organelle comprising 10–300 cylindrical, actin-filled stereocilia. A bundle’s structure is highly stereotyped: the stereocilia stand erect in a regular, hexagonal array and display a monotonic gradient in length along one axis. This precise organization is key to the operation of the hair bundle: mutations that disturb the morp...
The effect of radial power profile of DUPIC bundle on CHF
International Nuclear Information System (INIS)
The axial and ring power profiles of DUPIC bundle are much different from those of reference 37-element fuel bundle since a DUPIC fuel bundle is re-fabricated using spent PWR fuel and 2-bundle shift refuelling scheme is proposed to CANDU-6 reactor. In case that the ring power profile of a fuel bundle is altered, the flow and enthalpy distribution of subchannels and the radial position of CHF occurrence will be changed. Similarly, the axial power profile of a fuel channel affects CHF and axial position of CHF occurrence as well as axial enthalpy, quality and pressure distribution. The ring power profile of the DUPIC bundle as increasing burnup is altered and flattened compared to 37-element bundle and each fuel bundle in a fuel channel has a different ring power profile from the other bundles at different axial position in the same fuel channel. Therefore, how to consider the burnup or ring power effect on CHF is very important to DUPIC thermalhydraulic analysis. At present study, thermalhydraulic analysis of the DUPIC bundle was performed in consideration of ring power profile effect on CHF. The subchannel enthalpy, mass flux and CHF distribution for 0 burnup to discharged burnup (18,000 MWD/THM) of DUPIC bundle were evaluated using ASSERT subchannel code. The results were compared to those of 37-element bundle and the compatability of DUPIC bundle with an existing CANDU-6 was presented in a CHF point of view
Phase Space Reduction of Star Products on Cotangent Bundles
Kowalzig, Niels; Neumaier, Nikolai; Pflaum, Markus J.
2004-01-01
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 symplectique structure of form $\\omega_{B_0}=\\omega_0 + \\pi^*B_0$ with $B_0$ a closed two-form on $Q$, is equipped by the cotangent lift of a proper and free Lie group action on $Q$ and by an invariant star product that admits a $G$-equ...
The Determinant Bundle on the Moduli Space of Stable Triples over a Curve
Indian Academy of Sciences (India)
Indranil Biswas; N Raghavendra
2002-08-01
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 holomorphic Hermitian line bundle is computed. The curvature is shown to coincide with a constant scalar multiple of the natural Kähler form on the moduli space. The construction is based on a result of Quillen on the determinant line bundle over the space of Dolbeault operators on a fixed ∞ Hermitian vector bundle over a compact Riemann surface.
Quillen Bundle and Geometric Prequantization of Non-Abelian Vortices on a Riemann Surface
Indian Academy of Sciences (India)
Rukmini Dey; Samir K Paul
2011-02-01
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 modified Quillen metric. Next, as in the case of abelian vortices, we construct line bundles over the moduli space whose curvatures form a family of symplectic forms which are parametrized by $\\Psi_0$, a section of a certain bundle. The equivalence of these prequantum bundles are discussed.
Assembly and operation experience of EVA II steam reforming bundle
International Nuclear Information System (INIS)
The main test component of the experimental facility EVA-II/ADAM-II is a helium heated steam reformer bundle with 30 tubes. The tubes are filled with a catalyst of raschig ring type. The main test of the component were related to the power dependence. A series of experiment dealt with the influence of steam/methane ratio on the carbon deposit formation
A Method of Assembling Compact Coherent Fiber-Optic Bundles
Martin, Stefan; Liu, Duncan; Levine, Bruce Martin; Shao, Michael; Wallace, James
2007-01-01
A method of assembling coherent fiber-optic bundles in which all the fibers are packed together as closely as possible is undergoing development. The method is based, straightforwardly, on the established concept of hexagonal close packing; hence, the development efforts are focused on fixtures and techniques for practical implementation of hexagonal close packing of parallel optical fibers.
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.
Coupling Systems of Five CARA Fuel Bundles for Atucha I
International Nuclear Information System (INIS)
This paper describe the mechanical design of two options for the coupling systems of five CARA fuel bundles, to be used in the Atucha I nuclear power plant. These systems will be hydraulic tested in a low pressure loop to know their hydraulic loss of pressure
Heat transfer and fluid friction in bundles of twisted tubes
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.
Self-adjointness of the Gaffney Laplacian on Vector Bundles
Energy Technology Data Exchange (ETDEWEB)
Bandara, Lashi, E-mail: lashi.bandara@chalmers.se [Chalmers University of Technology and University of Gothenburg, Mathematical Sciences (Sweden); Milatovic, Ognjen, E-mail: omilatov@unf.edu [University of North Florida, Department of Mathematics and Statistics (United States)
2015-12-15
We study the Gaffney Laplacian on a vector bundle equipped with a compatible metric and connection over a Riemannian manifold that is possibly geodesically incomplete. Under the hypothesis that the Cauchy boundary is polar, we demonstrate the self-adjointness of this Laplacian. Furthermore, we show that negligible boundary is a necessary and sufficient condition for the self-adjointness of this operator.
Rigidity of Minimal Submanifolds with Flat Normal Bundle
Indian Academy of Sciences (India)
Hai-Ping Fu
2010-09-01
Let $M^n(n≥ 3)$ be an -dimensional complete immersed $\\frac{n-2}{n}$-superstable minimal submanifold in an $(n+p)$-dimensional Euclidean space $\\mathbb{R}^{n+p}$ with flat normal bundle. We prove that if the second fundamental form of satisfies some decay conditions, then is an affine plane or a catenoid in some Euclidean subspace.
A comprehensive comparison on vibration and heat transfer of two elastic heat transfer tube bundles
Institute of Scientific and Technical Information of China (English)
闫柯; 葛培琪; 翟强
2015-01-01
Elastic heat transfer tube bundles are widely used in the field of flow-induced vibration heat transfer enhancement. Two types of mainly used tube bundles, the planar elastic tube bundle and the conical spiral tube bundle were comprehensively compared in the condition of the same shell side diameter. The natural mode characteristics, the effect of fluid−structure interaction, the stress distribution, the comprehensive heat transfer performance and the secondary fluid flow of the two elastic tube bundles were all concluded and compared. The results show that the natural frequency and the critical velocity of vibration buckling of the planar elastic tube bundle are larger than those of the conical spiral tube bundle, while the stress distribution and the comprehensive heat transfer performance of the conical spiral tube bundle are relatively better.
Semistability of Certain Bundles on Second Symmetric Power of a Curve
Dan, Krishanu; Pal, Sarbeswar
2015-01-01
Let $C$ be a smooth irreducible projective curve and $E$ be a rank 2 stable vector bundle on $C$. Then one can associate a rank 4 vector bundle $\\mathcal{F}_2(E)$ on $S^2(C)$, second symmetric power of $C$. Our goal in this article is to study semistability of this bundle.
Biswas, Indranil
2011-01-01
We construct projectivization of a parabolic vector bundle and a tautological line bundle over it. It is shown that a parabolic vector bundle is ample if and only if the tautological line bundle is ample. This allows us to generalize the notion of a k-ample bundle, introduced by Sommese, to the context of parabolic bundles. A parabolic vector bundle $E_*$ is defined to be k-ample if the tautological line bundle ${\\mathcal O}_{{\\mathbb P}(E_*)}(1)$ is $k$--ample. We establish some properties of parabolic k-ample bundles.
Simon Newcomb, Other Aspects of His Career
Corbin, Brenda G.
2014-01-01
Simon Newcomb (1835-1909) is perhaps the best known American astronomer of the late 19th century. Among the many aspects of his long career, he was one of the founders and the first president of what later became the American Astronomical Society. However, he wrote widely on subjects other than astronomy, even producing works of fiction. He was especially interested in economics and published such titles as A critical examination of our financial policy during the Southern rebellion, A plain man's talk on the labor question, Principles of political economy and others. The very interesting title, A statistical inquiry into the probability of causes of the production of sex in human offspring was written in 1904. Newcomb even produced a work of science fiction, His Wisdom, the Defender: a story, published in 1900. William Alvord, President of the Astronomical Society of the Pacific, on awarding Newcomb the Bruce Medal stated “The essential quality of his mind is that of a philosopher rather than that of a mathematician or an astronomer merely.” It has been suggested (Bradley Schaefer and others) that Arthur Conan Doyle used Newcomb as the model for Prof. Moriarty in his Sherlock Holmes novels. He had close friendships with many scientists of his time including Alexander Graham Bell. On the other hand, it has been reported that he also had contentious relationships with some scientists and could be intimidating. A devoted family man, he encouraged his three daughters in their intellectual pursuits. Newcomb, who held naval rank in the Corps of Professors of Mathematics, was buried in Arlington National Cemetery with full military honors. His funeral was attended by many noted scientists and other dignitaries including President William Howard Taft.
Twisted Partial Actions, A Classification of Stable C*-Algebraic Bundles (Preliminary Version)
Exel, Ruy
1994-01-01
We introduce the notion of continuous twisted partial actions of a locally compact group on a C*-algebra. With such, we construct an associated C*-algebraic bundle called the semidirect product bundle. Our main theorem shows that, given any C*-algebraic bundle which is second countable and whose unit fiber algebra is stable, there is a continuous twisted partial action of the base group on the unit fiber algebra, whose associated semidirect product bundle is isomorphic to the given one.
Equilibrium Bundle Size of Rodlike Polyelectrolytes with Counterion-Induced Attractive Interactions
Henle, Mark L.; Pincus, Philip A.
2004-01-01
Multivalent counterions can induce an effective attraction between like-charged rodlike polyelectrolytes, leading to the formation of polelectrolyte bundles. In this paper, we calculate the equilibrium bundle size using a simple model in which the attraction between polyelectrolytes (assumed to be pairwise additive) is treated phenomenologically. If the counterions are point-like, they almost completely neutralize the charge of the bundle, and the equilibrium bundle size diverges. When the co...
Effect of left bundle branch block on TIMI frame count
Hatice Tolunay; Ahmet Kasapkara; İsa Öner Yüksel; Nurcan Başar; Ayşe Saatcı Yaşar; Mehmet Bilge
2010-01-01
Aim: Left bundle branch block is an independent risk factorfor cardiac mortality. In this study we aimed to evaluatecoronary blood flow with TIMI frame count in patients with left bundle branch block and angiographically proven normal coronary arteries.Materials and methods: We retrospectively studied 17 patients with left bundle branch block and as a control group 16 patients without left bundle branch block. All patientshad angiographically proven normal coronary arteries.Left bundle branch...
The existence of a kind of bundle map
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
3 By means of the theory of Postnikov resolution, a sufficient condition for the existence of a kind of bundle maps is obtained. Some applications of the result are given. Particularly, it is proven that the deleted products as well as configuration spaces of two simply connected manifolds with suitable dimension have the same homotopy type when the original manifolds are homotopically equivalent.
Balancing Newton's mind: his singular behaviour and his madness of 1692-93.
Keynes, Milo
2008-09-20
Newton grew up with a vulnerable and eccentric character besides having a low self-esteem, and he was someone who only uncommonly developed any close relationships. On review it is argued that his distrust and suspicions of others, and the fear that he might be harmed by criticism and his discoveries stolen, followed from his mother's separation from him in childhood and not, as has been claimed, from the developmental disorder of Asperger's syndrome. It is further firmly argued that his 'madness' of 1692 and 1693 was due to mercury poisoning from his alchemical experiments and not to clinical depression.
On the Topology of Real Bundle Pairs over Nodal Symmetric Surfaces
Georgieva, Penka
2015-01-01
We give an alternative argument for the classification of real bundle pairs over smooth symmetric surfaces and extend this classification to nodal symmetric surfaces. We also classify the homotopy classes of automorphisms of real bundle pairs over symmetric surfaces. The two statements together describe the isomorphisms between real bundle pairs over symmetric surfaces up to deformation.
Persistence Length and Nanomechanics of Random Bundles of Nanotubes
Energy Technology Data Exchange (ETDEWEB)
Yakobson, Boris I. [Rice University, Department of Mechanical Engineering and Materials Science, Department of Chemistry, and Center for Nanoscale Science and Technology (United States)], E-mail: biy@rice.edu; Couchman, Luise S. [Naval Research Laboratory, Code 7130 (United States)
2006-02-15
A connection between the stiffness of carbon nanotubes (CNT) and their mesoscopic physical behaviour is presented. Persistence lengths of CNT and bundles are calculated and shown to be in macroscopic range (0.03-1 mm for an individual tube), exceeding by many orders of magnitude the typical diameters (around 1-3 nm). Consequently, thermal fluctuations can be neglected when scaling analysis is applied to randomly packed (as produced) CNT network, leading to an approximate equation of state for such material. Beyond the linear elasticity, the outmost CNT are shown to gradually split from the bent bundles; this permits access of solvent or reacting species to the CNT walls, an important mechanism promoting solubilization and chemical functionalization of nanotubes.
Frobenius Pull Backs of Vector Bundles in Higher Dimensions
Indian Academy of Sciences (India)
V Trivedi
2012-11-01
We prove that for a smooth projective variety of arbitrary dimension and for a vector bundle over , the Harder–Narasimhan filtration 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, to show that some lower bound on is necessary. We also give a bound on the instability degree of the Frobenius pull back of in terms of the instability degree of and well defined invariants of .
[Harvey and his theory of circulation].
Wolters, Frank J
2013-01-01
In 1628 the English physician William Harvey (1578-1657) published his revolutionary theory that blood circulates through the body driven by the heart. This challenged the long-standing teachings of Hippocrates and Galen concerning 4 different bodily fluids or 'humours' that flowed through separate arterial and venous vascular systems. Harvey gained considerable influence in society as a member of the prestigious Royal College of Physicians in London and as personal physician to King James I and King Charles I. He strove for a more empirical foundation of medicine by means of anatomic demonstrations and vivisections. Despite enduring considerable criticism he managed to disseminate his ideas around the influential universities of Europe in the course of his lifetime. However, consequent changes in practice would not be brought about until decades after Harvey's death, when Galenist treatments such as blood-letting were gradually abandoned.
Linear duals of graded bundles and higher analogues of (Lie) algebroids
Bruce, Andrew James; Grabowska, Katarzyna; Grabowski, Janusz
2016-03-01
Graded bundles are a class of graded manifolds which represent a natural generalisation of vector bundles and include the higher order tangent bundles as canonical examples. We present and study the concept of the linearisation of graded bundle which allows us to define the notion of the linear dual of a graded bundle. They are examples of double structures, graded-linear (GL) bundles, including double vector bundles as a particular case. On GL-bundles we define what we shall call weighted algebroids, which are to be understood as algebroids in the category of graded bundles. They can be considered as a geometrical framework for higher order Lagrangian mechanics. Canonical examples are reductions of higher tangent bundles of Lie groupoids. Weighted algebroids represent also a generalisation of VB-algebroids as defined by Gracia-Saz & Mehta and the LA-bundles of Mackenzie. The resulting structures are strikingly similar to Voronov's higher Lie algebroids, however our approach does not require the initial structures to be defined on supermanifolds.
Nuclear spin relaxation due to random motion of vortex bundles
International Nuclear Information System (INIS)
The dependence of nuclear-spin-relaxation rate T1 on NMR resonant frequency for a layered superconducting sample has been analyzed theoretically. In the considered arrangement the Zeeman field has been applied in the plane of superconducting layers while the relaxation was due to interactions between the spin systems and moving flux bundles, created by the transport current flowing along superconducting layers. It has been found that the functional form of a dependence of spin-relaxation rate on the Zeeman field has two components, a Lorentzian and an oscillatory one. The characteristic rolloff frequency of the Lorentzian component depends on the pinning properties of the sample. The period of oscillations of the oscillatory component is of the order of the inverse of interaction time of flowing flux bundles with a probe nucleus. copyright 1996 The American Physical Society
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.
A class of recursion operators on a tangent bundle
Vermeire, F.; Sarlet, W.; Crampin, M.
2006-06-01
We generalize the construction of a class of type (1, 1) tensor fields R on a tangent bundle which was introduced in a preceding paper. The generalization comes from the fact that, apart from a given Lagrangian, the further data consist of a type (1, 1) tensor J along the tangent bundle projection τ: TQ →Q, rather than a tensor on Q. The main features under investigation are two kinds of recursion properties of R, namely its potential invariance under the flow of the given dynamics and the property of having vanishing Nijenhuis torsion. The theory is applied, in particular, to the case of second-order dynamics coming from a Finsler metric.
A class of recursion operators on a tangent bundle
Energy Technology Data Exchange (ETDEWEB)
Vermeire, F [Department of Mathematical Physics and Astronomy, Ghent University, Krijgslaan 281, B-9000 Ghent (Belgium); Sarlet, W [Department of Mathematical Physics and Astronomy, Ghent University, Krijgslaan 281, B-9000 Ghent (Belgium); Crampin, M [Department of Mathematical Physics and Astronomy, Ghent University, Krijgslaan 281, B-9000 Ghent (Belgium)
2006-06-09
We generalize the construction of a class of type (1, 1) tensor fields R on a tangent bundle which was introduced in a preceding paper. The generalization comes from the fact that, apart from a given Lagrangian, the further data consist of a type (1, 1) tensor J along the tangent bundle projection {tau}: TQ {yields}Q, rather than a tensor on Q. The main features under investigation are two kinds of recursion properties of R, namely its potential invariance under the flow of the given dynamics and the property of having vanishing Nijenhuis torsion. The theory is applied, in particular, to the case of second-order dynamics coming from a Finsler metric.
Integral Canonical Models for Automorphic Vector Bundles of Abelian Type
Lovering, Tom
2016-01-01
We define and construct integral canonical models for automorphic vector bundles over Shimura varieties of abelian type. More precisely, we first build on Kisin's work to construct integral canonical models over rings of integers of number fields with finitely many primes inverted for Shimura varieties of abelian type with hyperspecial level at all primes we do not invert, compatible with Kisin's construction. We then define a notion of an integral canonical model for the standard principal b...
On phenomena of turbulent flow through rod bundles
International Nuclear Information System (INIS)
Experimental studies have shown that the axial and azimuthal turbulence intensities in the gap regions of rod bundles increase strongly with decreasing rod spacing; the fluctuating velocities in the axial and azimuthal directions have a quasi-periodic behavior. To determine the origin of this phenomenon and its characteristic as a function of the geometry and the Reynolds number, an experimental investigation was performed on the turbulent flow in several rod bundles with different aspect ratios (P/D, W/D). Hot-wires and microphones were used for the measurements of velocity and wall pressure fluctuations. The data were evaluated to obtain spectra as well as auto and cross correlations. Based on the results, a phenomenological model is proposed to explain this phenomenon. By means of the model, the mass exchange between neighbouring subchannels is explained. (orig.)
Multiplexed holographic memory by use of fiber bundle referencing
Zhang, Jiasen; Aruga, Tadashi
2005-04-01
We propose a volume holographic storage technique, in which a fiber bundle is used to guide the reference beam. Multiplexing is implemented by changing the incident direction of the laser beam upon the fiber bundle in the reference arm. In the technique, we make the system more compact by using a wedge prism to change the direction of the laser beam. This method has a large accessible angular scanning range and a large geometric storage bandwidth. Multiple images are stored in a LiNbO3:Fe crystal with an angular separation of 0.05° between successive holograms using a wedge prism with a deviation angle of 8°. This method is useful as a new image storage technique because of its compactness and simplicity.
The Assurance of CHRIST to His followers
Asumadu-Sarkodie, Samuel
2012-01-01
The Assurance of CHRIST to His followers. Assurance: grk. Hupostasis meaning: full and sustained confidence and trust; unwavering conviction. There is a favourite Ghanaian proverb which says "if a naked man says he will clothe you, listen to him quietly". Before someone could assure you of something, he must be self-reliant or independent. Christ Jesus has assured His followers because He is capable, has done it before, continues to do it and will do it. Isaiah 50:4-9a; talks about the qualif...
Lateral mechanical coupling of stereocilia in cochlear hair bundles.
Langer, M G; Fink, S.; Koitschev, A; Rexhausen, U; Hörber, J K; Ruppersberg, J P
2001-01-01
For understanding the gating process of transduction channels in the inner ear it is essential to characterize and examine the functional properties of the ultrastructure of stereociliary bundles. There is strong evidence that transduction channels in hair cells are gated by directly pulling at the so-called tip links. In addition to these tip links a second class of filamentous structures was identified in the scanning and transmission electron microscope: the side-to-side links. These links...
Universality Class of Fiber Bundle Model on Complex Networks
Kim, Dong-Hee; Kim, Beom Jun; Jeong, Hawoong
2004-01-01
We investigate the failure characteristics of complex networks within the framework of the fiber bundle model subject to the local load sharing rule in which the load of the broken fiber is transferred only to its neighbor fibers. Although the load sharing is strictly local, it is found that the critical behavior belongs to the universality class of the global load sharing where the load is transferred equally to all fibers in the system. From the numerical simulations and the analytical appr...
CAT reconstruction and potting comparison of a LMFBR fuel bundle
International Nuclear Information System (INIS)
A standard Liquid Metal Fast Breeder Reactor (LMFBR) subassembly used in the Experimental Breeder Reactor II (EBR-II) was investigated, by remote techniques, for fuel bundle distortion by both nondestructive and destructive methods, and the results from both methods were compared. The non-destructive method employed neutron tomography to reconstruct the locations of fuel elements through the use of a maximum entropy reconstruction algorithm known as MENT. The destructive method consisted of ''potting'' (a technique that embeds and permanently fixes the fuel elements in a solid matrix) the subassembly, and then cutting and polishing the individual sections. The comparison indicated that the tomography reconstruction provided good results in describing the bundle geometry and spacer-wire locations, with the overall resolution being on the order of a spacer-wire diameter. A dimensional consistency check indicated that the element and spacer-wire dimensions were accurately reproduced in the reconstruction
Infinitesimal moduli of G2 holonomy manifolds with instanton bundles
de la Ossa, Xenia; Svanes, Eirik Eik
2016-01-01
We describe the infinitesimal moduli space of pairs $(Y, V)$ where $Y$ is a manifold with $G_2$ holonomy, and $V$ is a vector bundle on $Y$ with an instanton connection. These structures arise in connection to the moduli space of heterotic string compactifications on compact and non-compact seven dimensional spaces, e.g. domain walls. Employing the canonical $G_2$ cohomology $H^*_{{\\check{\\rm d}}_E}(Y,E)$ developed by Reyes-Carri\\'on and Fern\\'andez and Ugarte, we show that the moduli space decomposes into the sum of the bundle moduli $H^1_{{\\check{\\rm d}}_A}(Y,{\\rm End}(V))$ plus the moduli of the $G_2$ structure preserving the instanton condition. The latter piece is contained in $H^1_{{\\check{\\rm d}}_\
The special linear version of the projective bundle theorem
Ananyevskiy, Alexey
2012-01-01
A special linear Grassmann variety SGr(k,n) is the complement to the zero section of the determinant of the tautological vector bundle over Gr(k,n). For a representable ring cohomology theory A(-) with a special linear orientation and invertible stable Hopf map \\eta, including Witt groups and MSL[\\eta^{-1}], we have A(SGr(2,2n+1))=A(pt)[e]/(e^{2n}), and A(SGr(2,2n)) is a truncated polynomial algebra in two variables over A(pt). A splitting principle for such theories is established. We use the computations for the special linear Grassmann varieties to calculate A(BSL_n) in terms of the homogeneous power series in certain characteristic classes of the tautological bundle.
Wrap groups of fiber bundles over quaternions and octonions
Ludkovsky, S. V.
2008-01-01
This article is devoted to the investigation of wrap groups of connected fiber bundles over the fields of real $\\bf R$, complex $\\bf C$ numbers, the quaternion skew field $\\bf H$ and the octonion algebra $\\bf O$. These groups are constructed with mild conditions on fibers. Their examples are given. It is shown, that these groups exist and for differentiable fibers have the infinite dimensional Lie groups structure, that is, they are continuous or differentiable manifolds and the composition $...
Conservation of helical bundle structure between the exocyst subunits.
Directory of Open Access Journals (Sweden)
Nicole J Croteau
Full Text Available BACKGROUND: The exocyst is a large hetero-octomeric protein complex required for regulating the targeting and fusion of secretory vesicles to the plasma membrane in eukaryotic cells. Although the sequence identity between the eight different exocyst subunits is less than 10%, structures of domains of four of the subunits revealed a similar helical bundle topology. Characterization of several of these subunits has been hindered by lack of soluble protein for biochemical and structural studies. METHODOLOGY/PRINCIPAL FINDINGS: Using advanced hidden Markov models combined with secondary structure predictions, we detect significant sequence similarity between each of the exocyst subunits, indicating that they all contain helical bundle structures. We corroborate these remote homology predictions by identifying and purifying a predicted domain of yeast Sec10p, a previously insoluble exocyst subunit. This domain is soluble and folded with approximately 60% alpha-helicity, in agreement with our predictions, and capable of interacting with several known Sec10p binding partners. CONCLUSIONS/SIGNIFICANCE: Although all eight of the exocyst subunits had been suggested to be composed of similar helical bundles, this has now been validated by our hidden Markov model structure predictions. In addition, these predictions identified protein domains within the exocyst subunits, resulting in creation and characterization of a soluble, folded domain of Sec10p.
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.
Explicit presentations of nonspecial line bundles and secant spaces
Kim, Seonja
2012-01-01
A line bundle L on a smooth curve X is nonspecial if and only if L admits a presentation L=K_X -D +E for some effective divisors D and E>0 on X with gcd (D, E)=0 and h^0 (X, O_X (D))=1. In this work, we define a minimal presentation of L which is minimal with respect to the degree of E among the presentations. If L=K_X -D +E with degE>2 is a minimal, then L is very ample and any q-points of X with q
The effects of fee bundling on dental utilization.
Porter, J.; Coyte, P. C.; Barnsley, J.; Croxford, R.
1999-01-01
OBJECTIVE: To examine dental utilization following an adjustment to the provincial fee schedule in which preventive maintenance (recall) services were bundled at lower fees. DATA SOURCES/STUDY SETTING: Blue Cross dental insurance claims for claimants associated with four major Ontario employers using a common insurance plan over the period 1987-1990. STUDY DESIGN: This before-and-after design analyzes the dental claims experience over a four-year period for 4,455 individuals 18 years of age a...
Bagger-Witten line bundles on moduli spaces of elliptic curves
Gu, W
2016-01-01
In this paper we discuss Bagger-Witten line bundles over moduli spaces of SCFTs. We review how in general they are `fractional' line bundles, not honest line bundles, twisted on triple overlaps. We discuss the special case of moduli spaces of elliptic curves in detail. There, the Bagger-Witten line bundles does not exist as an ordinary line bundle, but rather is necessarily fractional. As a fractional line bundle, it is nontrivial (though torsion) over the uncompactified moduli stack, and its restriction to the interior, excising corners with enhanced stabilizers, is also fractional. We review and compare to results of recent work arguing that well-definedness of the worldsheet metric implies that the Bagger-Witten line bundle is torsion, and give general arguments on the existence of universal structures on moduli spaces of SCFTs, in which superconformal deformation parameters are promoted to nondynamical fields ranging over the SCFT moduli space.
Bundling in Telecommunications
Begoña García-Mariñoso; Xavier Martinez-Giralt; Pau Olivella
2008-01-01
The paper offers an overview of the literature on bundling in the telecommunications sector and its application in the Spanish market. We argue that the use of bundling in the provision of services is associated to technological reasons. Therefore, there appears no need to regulate bundling activities. However, this is not to say that other related telecom markets should not be scrutinized and regulated, or that the regulator should not pay attention to other bundling-related anticompetitive ...
Institute of Scientific and Technical Information of China (English)
LUO Hao; AO Ying-fang; ZHANG Wei-guang; LIU Sheng-yong; ZHANG Ji-ying; YU Jia-kuo
2012-01-01
Background Several techniques have been described for posterior cruciate ligament(PCL)reconstruction.However,double-bundle PCL reconstruction using the quadruple bone-tunnel technique has been seldom reported.The current study investigated this technique,focusing on the anatomy of the femoral and tibial insertions of the anterolateral(AL)and posteromedial(PM)bundles of the PCL.Methods Twenty-two fresh,healthy adult cadaveric knees were dissected and measured.The PCL was divided into the AL bundle and PM bundle at the insertion footprint.The insertion footprints of the AL and PM bundles,their location,size,and the clock positions were measured and described.Results On the femur,the clock position of the footprint of the AL bundle was 11:21±0:23(left)or 0:39±0:23(right),and the PM bundle was 9:50±0:18(left)or 2:10±0:18(right),with the knee flexed at 90 degrees.The distances from the center of the femoral insertions of the AL and PM bundles to the anterior cartilage margins of the medial femoral condyle were(7.79±1.22)mm and(8.36±1.63)mm,respectively.On the tibia,the vertical distances from the center of the tibial insertions of the AL and PM bundles to the tibial articular surface were(3.25±1.20)mm and(6.91±1.57)mm,respectively.Conclusions These results have led to a better definition of the anatomy of the AL and PM bundle footprint of the PCL.The technique of double-bundle PCL reconstruction using quadruple bone-tunnel is feasible.Application of these data during PCL reconstruction using the quadruple bone-tunnel technique may help optimize knee stability.
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.
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
Lateral mechanical coupling of stereocilia in cochlear hair bundles.
Langer, M G; Fink, S; Koitschev, A; Rexhausen, U; Hörber, J K; Ruppersberg, J P
2001-06-01
For understanding the gating process of transduction channels in the inner ear it is essential to characterize and examine the functional properties of the ultrastructure of stereociliary bundles. There is strong evidence that transduction channels in hair cells are gated by directly pulling at the so-called tip links. In addition to these tip links a second class of filamentous structures was identified in the scanning and transmission electron microscope: the side-to-side links. These links laterally connect stereocilia of the same row of a hair bundle. This study concentrates on mechanical coupling of stereocilia of the tallest row connected by side-to-side links. Atomic Force microscopy (AFM) was used to investigate hair bundles of outer hair cells (OHCs) from postnatal rats (day 4). Although hair bundles of postnatal rats are still immature at day 4 and interconnecting cross-links do not show preferential direction yet, hair bundles of investigated OHCs already showed the characteristic V-shape of mature hair cells. In a first experiment, the stiffness of stereocilia was investigated scanning individual stereocilia with an AFM tip. The spring constant for the excitatory direction was 2.5 +/- 0.6 x 10(-3) N/m whereas a higher spring constant (3.1 +/- 1.5 x 10(-3) N/m) was observed in the inhibitory direction. In a second set of experiments, the force transmission between stereocilia of the tallest row was measured using AFM in combination with a thin glass fiber. This fiber locally displaced a stereocilium while the force laterally transmitted to the neighboring untouched taller stereocilia was measured by AFM. The results show a weak force interaction between tallest stereocilia of postnatal rats. The force exerted to an individual stereocilium declines to 36% at the nearest adjacent stereocilium of the same row not touched with the fiber. It is suggested that the amount of force transmitted from a taller stereocilium to an adjacent one of the same row depends
Investigations on flow induced vibration of simulated CANDU fuel bundles in a pipe
International Nuclear Information System (INIS)
In this paper, vibration of a two-bundle string consisting of simulated CANDU fuel bundles subjected to turbulent liquid flow is investigated through numerical simulations and experiments. Large eddy simulation is used to solve the three-dimensional turbulent flow surrounding the fuel bundles for determining fluid excitations. The CFD model includes pipe flow, flow through the inlet fuel bundle along with its two endplates, half of the second bundle and its upstream endplate. The fluid excitation obtained from the fluid model is subsequently fed into a fuel bundle vibration code written in FORTRAN. Fluid structure interaction terms for the fuel elements are approximated using the slender body theory. Simulation results are compared to measurements conducted on the simulated fuel bundles in a testing hydraulic loop. (author)
Sadoghi, Patrick; Mueller, Peter E.; Jansson, Volkmar; van Griensven, Martin; Kroepfl, Albert; Fischmeister, Martin F.
2011-01-01
The study hypothesis was that the outcome of semitendinosus gracilis double bundle (STG-DB) anterior cruciate ligament (ACL) reconstruction is advantageous in terms of clinical results and restoration of anterior-posterior and rotational laxity in comparison to bone-patellar tendon-bone single-bundl
Comparison of ASSERT subchannel code with Marviken bundle data
International Nuclear Information System (INIS)
In this paper ASSERT predictions are compared with the Marviken 6-rod bundle and 36+1 rod bundle. The predictions are presented for two experiments in the 6-rod bundle and four experiments in the 36+1 rod bundle. For low inlet subcooling, the void predictions are in good agreement with the experimental data. For high inlet subcooling, however, the agreement is not as good. This is attributed to the fact that in the high inlet subcooling experiments, single phase turbulent mixing plays a more important role in determining flow conditions in the bundle
On the permeability of fractal tube bundles
Zinovik, I
2011-01-01
The permeability of a porous medium is strongly affected by its local geometry and connectivity, the size distribution of the solid inclusions and the pores available for flow. Since direct measurements of the permeability are time consuming and require experiments that are not always possible, the reliable theoretical assessment of the permeability based on the medium structural characteristics alone is of importance. When the porosity approaches unity, the permeability-porosity relationships represented by the Kozeny-Carman equations and Archie's law predict that permeability tends to infinity and thus they yield unrealistic results if specific area of the porous media does not tend to zero. The goal of this paper is an evaluation of the relationships between porosity and permeability for a set of fractal models with porosity approaching unity and a finite permeability. It is shown that the two-dimensional foams generated by finite iterations of the corresponding geometric fractals can be used to model poro...
Signature modulo 8 of fibre bundles
Rovi, Carmen
2015-01-01
Lay summary Topology studies the geometric properties of spaces that are preserved by continuous deformations. Manifolds are the main examples of topological spaces, with the local properties of Euclidean space in an arbitrary dimension n. They are the higher dimensional analogs of curves and surfaces. For example a circle is a one-dimensional manifold. Balloons and doughnuts are examples of two-dimensional manifolds. A balloon cannot be deformed continuously into a doughnut...
Interconnection of bundled solid oxide fuel cells
Brown, Michael; Bessette, II, Norman F; Litka, Anthony F; Schmidt, Douglas S
2014-01-14
A system and method for electrically interconnecting a plurality of fuel cells to provide dense packing of the fuel cells. Each one of the plurality of fuel cells has a plurality of discrete electrical connection points along an outer surface. Electrical connections are made directly between the discrete electrical connection points of adjacent fuel cells so that the fuel cells can be packed more densely. Fuel cells have at least one outer electrode and at least one discrete interconnection to an inner electrode, wherein the outer electrode is one of a cathode and and anode and wherein the inner electrode is the other of the cathode and the anode. In tubular solid oxide fuel cells the discrete electrical connection points are spaced along the length of the fuel cell.
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.)
Black-and-White Bundles of Joy
Institute of Scientific and Technical Information of China (English)
2007-01-01
Panda cubs pose with sponsors of the Wolong Giant Panda Protection and Research Center in southwest China’s Sichuan Province before they were moved outdoors in early February.The 18 weanling coddles, all about six months old, will live together in a garden at the Wolong center for half a year before they are separated. They will then be trained and selected for an experimental program designed to release captive-bredpandas to the wild. The Wolong center saw births of 19 panda cubs in 12 deliveries last year, with 17 survivals, a historical record. In addition, it saved and bred a cub delivered by a wild panda last August. Giant pandas, only found in China, are known as “living fossils” and about 1,590 still live in the wilds of Sichuan, Shaanxi and Gansu provinces.Currently, about 200 pandas are being bred in captivity worldwide, over half of which are living at the Wolong center.
A Universal Family of Deformations for the Uniformising Higgs bundle
Dalakov, Peter
2011-01-01
Fix a simple complex Lie group G and a principal sl(2,C) subalgebra of Lie(G). Then the moduli space of semi-stable, topologically trivial G-Higgs bundles on a hyperbolic, spin Riemann surface acquires a marked point. This is the unique C*-fixed point on the Hitchin section. We describe a universal analytic family of deformations which provides holomorphic Darboux coordinates in a neighbourhood of the section. This is a special case of a more general deformation-theoretic construction in the spirit of Kuranishi theory. As a toy example of the latter we consider the tautological family of centralisers over the Kostant slice.
Parameter design and optimization of tight-lattice rod bundles
International Nuclear Information System (INIS)
Thin rod bundles with tight lattice are arranged according to the equilateral triangle grid, as the proportion of fuel is large, and the power density of core is high. Based on the analysis of the performance of core, the ABV-6M reactor is taken as the example, and two objective functions, power density and flow rate of coolant are proposed for optimization calculation. Diameter and pitch of rod are optimized by using GA method respectively. The results, which are considered to be safety in security checking, show that tight lattice is effective for improving the power density and other performances of the reactor core. (author)
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.
Heal, Geoffrey
2002-01-01
Biodiversity provides essential services to human societies. Many of these services are provided as public goods, so that they will typically be underprovided both by market mechanisms (because of the impossibility of excluding non-payers from using the services) and by government-run systems (because of the free rider problem). I suggest here that in some cases the public goods provided by biodiversity conservation can be bundled with private goods and their value to consumers captured in th...
Bundle adjustment for data processing of theodolite industrial surveying system
Institute of Scientific and Technical Information of China (English)
邹峥嵘; 丁晓利; 曾卓乔; 何凭宗
2001-01-01
The photogrammetric bundle adjustment was used in data processing of electronic theodolite industrial surveying system by converting angular observations into virtual photo coordinates. The developed algorithm has ability of precision estimation and data-snooping, do not need initial values of exterior orientation elements and object point coordinates. The form of control condition for the system is quite flexible. Neither centering nor leveling is the theodolite needed and the lay-out of theodolite position is flexible when the system is used for precise survey. Experiments carried out in test field verify the validity of the data processing method.
On bundles of rank 3 computing Clifford indices
Lange, H
2012-01-01
Let $C$ be a smooth irreducible projective algebraic curve defined over the complex numbers. The notion of the Clifford index of $C$ was extended a few years ago to semistable bundles of any rank. Recent work has been focussed mainly on the rank-2 Clifford index, although interesting results have also been obtained for the case of rank 3. In this paper we extend this work, obtaining improved lower bounds for the rank-3 Clifford index. This allows the first computations of the rank-3 index in non-trivial cases and examples for which the rank-3 index is greater than the rank-2 index.
Quantum Bundle Description of the Quantum Projective Spaces
Buachalla, Réamonn Ó
2011-01-01
We realise Heckenberger and Kolb's canonical calculus on quantum projective (n-1)-space as the restriction of a distinguished quotient of the standard bicovariant calculus for Cq[SUn]. We introduce a calculus on the quantum (2n-1)-sphere in the same way. With respect to these choices of calculi, we present quantum projective (N-1)-space as the base space of two different quantum principal bundles, one with total space Cq[SUn], and the other with total space Cq[S^(2n-1)]. We go on to give Cq[C...
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.
Foliation, jet bundle and quantization of Einstein gravity
Park, I Y
2015-01-01
With the Hamiltonian and Lagrangian analyses in the ADM setup, it was observed in \\cite{Park:2014tia} that the physical configuration space of the 4D Einstein-Hilbert action admits a three-dimensional description. Subsequently, a more mathematical picture of the reduction based on foliation theory was presented in \\cite{Park:2014qoa}. In this work, we expand \\cite{Park:2014qoa} by adding another mathematical ingredient - an element of jet bundle theory - and present a more systematic and refined account thereof.
Padilla-Gamiño, J. L.; Weatherby, T. M.; Waller, R. G.; Gates, R. D.
2011-06-01
The majority of scleractinian corals are hermaphrodites that broadcast spawn their gametes separately or packaged as egg-sperm bundles during spawning events that are timed to the lunar cycle. The egg-sperm bundle is an efficient way of transporting gametes to the ocean surface where fertilization takes place, while minimizing sperm dilution and maximizing the opportunity for gamete encounters during a spawning event. To date, there are few studies that focus on the formation and structure of egg-sperm bundle. This study explores formation, ultrastructure, and longevity of the egg-sperm bundle in Montipora capitata, a major reef building coral in Hawai`i. Our results show that the egg-sperm bundle is formed by a mucus layer secreted by the oocytes. The sperm package is located at the center of each bundle, possibly reflecting the development of male and female gametes in different mesenteries. Once the egg-sperm bundle has reached the ocean surface, it breaks open within 10-35 min, depending on the environmental conditions (i.e., wind, water turbulence). Although the bundle has an ephemeral life span, the formation of an egg-sperm bundle is a fundamental part of the reproductive process that could be strongly influenced by climate change and deterioration of water quality (due to anthropogenic effects) and thus requires further investigation.
Significance of the resting angles of hair-cell bundles for Hopf bifurcation criticality
Kim, Kyung-Joong; Ahn, Kang-Hun
2016-08-01
We investigate the significance of the inclined angle of a hair bundle at equilibrium. We find that, while the angle gives a geometrical conversion factor between the bundle deflection and the ion channel displacement, it also controls the dynamics of the bundle. We show that a Hopf bifurcation, which enhances sensitivity, can be driven by the geometrical factor. However, existing experimental data indicate that mammalian auditory hair-cell bundles are located far away from the Hopf bifurcation point, suggesting that the high sensitivity of mammalian hearing might come from other mechanisms.
Semistable vector bundles and Tannaka duality from a computational point of view
Kaid, Almar
2011-01-01
We develop a semistability algorithm for vector bundles which are given as a kernel of a surjective morphism between splitting bundles on the projective space over an algebraically closed field K. This class of bundles is a generalization of syzygy bundles. We show how to implement this algorithm in a computer algebra system. Further we give applications, mainly concerning the computation of Tannaka dual groups of stable vector bundles of degree 0 on the projective space and on certain smooth complete intersection curves. We also use our algorithm to close a gap in a recent work of L. Costa, P. Macias Marques and R. M. Miro-Roig regarding the stability of the syzygy bundle of general forms. Finally, we apply our algorithm to provide a computational approach to tight closure. All algorithms are implemented in the computer algebra system CoCoA
Left bundle branch block: a rare ECG manifestation of hyperkalemia
Directory of Open Access Journals (Sweden)
Venkata Madhav M
2015-04-01
Full Text Available A 20-year-old female patient with chronic kidney disease was brought to our emergency medical department with symptoms of pain in chest and abdomen, vomitings. Laboratory testing revealed serum potassium 7.7 mEq/L, serum creatinine 9.1 mg/dL. Electrocardiogram (ECG showed left bundle branch block (LBBB pattern with left axis deviation, tall T waves and ST elevation. Among ECG alterations in hyperkalemia, LBBB is rare and is being reported in our case.
Redesign and replacement of Connecticut Yankee moisture separator/reheater (MSR) tube bundles
International Nuclear Information System (INIS)
This paper describes the various aspects of the tube bundle redesign and replacement coordinated by Northeast Utilities Service Company for the Connecticut Yankee Atomic Power Company during the plant's 1980 refueling outage. The main objective of the replacement was to improve the operating reliability along with secondary plant chemistry through the use of new bundle design and tube material. The considerations leading to the selection of material and design of the new bundles, the highlights of fabrication and bundle change-out, and the eddy current test experience and performance monitoring techniques and results are presented. 6 refs
Dislodgement of carbon nanotube bundles under pressure driven flow.
Baowan, Duangkamon; Cox, Barry J; Hill, James M
2010-04-16
Experimental and predicted flow rates through carbon nanotubes vary considerably but generally are reported to be well in excess of that predicted by the conventional Poiseuille flow, and therefore nanotubes embedded in a matrix might provide membranes with exceptional mass transport properties. In this paper, applied mathematical modelling is undertaken to estimate the three forces acting on a nanotube bundle, namely the molecular interaction force, the viscous force, and the static pressure force. In deducing estimates of these forces we introduce a modification of the notion of the effective dead area for a carbon nanotube membrane, and we calculate the total forces necessary to push one or more of the nanotubes out of the bundle, thus creating a channel through which further enhancement of flow may take place. However, careful analysis shows that the nett dislodgement force is entirely independent on the useable flow area, but rather depends only on the total cross-sectional area perpendicular to the flow. This rather surprising result is a consequence of the flow being steady and a balance of the viscous and pressure forces. PMID:20332554
Capillary bundle model of hydraulic conductivity for frozen soil
Watanabe, Kunio; Flury, Markus
2008-12-01
We developed a capillary bundle model to describe water flow in frozen soil. We assume that the soil can be represented as a bundle of cylindrical capillaries. We consider that the freezing point in the capillaries is depressed according to the Gibbs-Thomson effect and that when stable ice forms in a capillary, the ice forms in the center of the capillaries, leaving a circular annulus open for liquid water flow. We use the model to demonstrate how the hydraulic conductivity changes as a function of temperature for both saturated and unsaturated soils, using a sand and two silt loam soils as examples. As temperature decreases, more and more ice forms, and the water flux consequently decreases. In frozen soil near 0°C, water predominantly flows through ice-free capillaries, so that the hydraulic conductivity of frozen soil is similar to that of an unfrozen soil with a water content equal to the unfrozen water content of the frozen soil. At low temperatures, however, ice forms in almost all capillaries, and the hydraulic conductivity of frozen soil is greater than that of unfrozen soil with the same water potential.
Mohandas K. Gandhi and His Experience of Nature.
Power, Shahed
1991-01-01
This article traces the evolution of Gandhi's exemplary relationship with nature through vignettes from his long life. Annotated are the religious roots and the environmental origins of his philosophical development, his contact with vegetarians and theosophists, and his responses to a variety of issues raised by the cohabitation of humans with…
Post-irradiation examination of the 37M fuel bundle at Chalk River Laboratories (AECL)
Energy Technology Data Exchange (ETDEWEB)
Armstrong, J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Daniels, T. [Ontario Power Generation, Pickering, Ontario (Canada); Montin, J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)
2014-03-15
The modified (-element (37M) fuel bundle was designed by Ontario Power Generation (OPG) to improve Critical Heat Flux (CHF) performance in ageing pressure tubes. A modification of the conventional 37-element fuel bundle design, the 37M fuel bundle allows more coolant flow through the interior sub-channels by way of a smaller central element. A demonstration irradiation (DI) of thirty-two fuel bundles was completed in 2011 at OPG's Darlington Nuclear Generating Station to confirm the suitability of the 37M fuel bundles for full core implementation. In support of the DI, fuel elements were examined in the Chalk River Laboratories Hot Cells. Inspection activities included: Bundle and element visual examination; Bundle and element dimensional measurements; Verification of bundle and element integrity; and Internal Gas Volume Measurements. The inspection results for 37M were comparable to that of conventional 37-element CANDU fuel. Fuel performance parameters of the 37M DI fuel bundle and fuel elements were within the range observed for similarly operated conventional 37-element CANDU fuel. Based on these Post Irradiation Examination (PIE) results, 37M fuel performed satisfactorily. (author)
Overview of methods to increase dryout power in CANDU fuel bundles
Energy Technology Data Exchange (ETDEWEB)
Groeneveld, D.C., E-mail: degroeneveld@gmail.com [Chalk River Laboratories, AECL, Chalk River (Canada); University of Ottawa, Department of Mechanical Engineering, Ottawa (Canada); Leung, L.K.H. [Chalk River Laboratories, AECL, Chalk River (Canada); Park, J.H. [Korean Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2015-06-15
Highlights: • Small changes in bundle geometry can have noticeable effects on the bundle CHF. • Rod spacing devices can results in increases of over 200% in CHF. • CHF enhancement decays exponentially downstream from spacers. • CHF-enhancing bundle appendages also increase the post-CHF heat transfer. - Abstract: In CANDU reactors some degradation in the CCP (critical channel power, or power corresponding to the first occurrence of CHF in any fuel channel) will occur with time because of ageing effects such as pressure-tube diametral creep, increase in reactor inlet-header temperature, increased hydraulic resistance of feeders. To compensate for the ageing effects, various options for recovering the loss in CCP are described in this paper. They include: (i) increasing the bundle heated perimeter, (ii) optimizing the bundle configuration, (iii) optimizing core flow and flux distribution, (iv) reducing the bundle hydraulic resistance, (v) use of CHF-enhancing bundle appendages, (vi) more precise experimentation, and (vii) redefining CHF. The increase in CHF power has been quantified based on experiments on full-scale bundles and subchannel code predictions. The application of several of these CHF enhancement principles has been used in the development of the 43-rod CANFLEX bundle.
Numerical model for thermal and mechanical behaviour of a CANDU 37-element bundle
International Nuclear Information System (INIS)
Prediction of transient fuel bundle deformations is important for assessing the integrity of fuel and the surrounding structural components under different operating conditions including accidents. For numerical simulation of the interactions between fuel bundle and pressure tube, a reliable numerical bundle model is required to predict thermal and mechanical behaviour of the fuel bundle assembly under different thermal loading conditions. To ensure realistic representations of the bundle behaviour, this model must include all of the important thermal and mechanical features of the fuel bundle, such as temperature-dependent material properties, thermal viscoplastic deformation in sheath, fuel-to-sheath interactions, endplate constraints and contacts between fuel elements. In this paper, we present a finite element based numerical model for predicting macroscopic transient thermal-mechanical behaviour of a complete 37-element CANDU nuclear fuel bundle under accident conditions and demonstrate its potential for being used to investigate fuel bundle to pressure tube interaction in future nuclear safety analyses. This bundle model has been validated against available experimental and numerical solutions and applied to various simulations involving steady-state and transient loading conditions. (author)
Directory of Open Access Journals (Sweden)
Мирко Обрадовић
2011-12-01
Full Text Available This paper examines the tradition about Bias of Priene, one of the Seven Wise Men of Greece about whom many stories were told, his background and the meaning of his name. In the absence of reliable historical sources, testimonia mostly come from a variety of disparate sources compiled in Hellenistic times or later and we may only suppose that local anecdotes, proverbs and short sayings reflect historical events. The paper provides detailed treatment of the several conflicting traditions about Bias of Priene. Nevertheless, the surviving biographical information about Bias point to the period of the reign of King Croesus and the Persian conquest of Asia Minor (ca. 560–540 BC, as the best time of his political activity. For this reason he might be designated as the sixth-century philosopher and statesman who was a generation younger than most others from among the Seven Sages (e.g. Solon of Athens, Thales of Miletus, Pittacus of Mytilene, Periander of Corinth. In the second part of the paper the possible meaning of the name Bias has been examined. This name as a personal name was almost certainly taken from the heroic repertoire of Greek names with an intention of connecting Bias’s family, who obviously belonged to the aristocracy of Priene, with the world of heroes, and through them, with the world of gods. The most famous mythical bearer of the name Bias was the hero Bias, the son of Amythaon and the brother of the legendary seer and healer Melampus. This Bias married Pero, the daughter of Neleus, the founder of Pylos in Messenia, and he had with her glorious offspring, before he settled in Argos. The choice of that heroic name as a personal name in the family of the wise Prienian might not be by chance, and it can be best explained with possible Neleid and Messenian connections generally existing among the local aristocracy in the Ionian poleis of the Archaic period. These connections were quite expected because the Neleids were ubiquitous
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.
Institute of Scientific and Technical Information of China (English)
Kang, Liping; Jiang, Yishu; Tang, Xiuhua; Yang, Mingyang; Liu, Zonghuai
2012-01-01
One-dimensional manganese oxide nanobelt bundles with birnessite-type structure have been synthesized by a hydrothermal process in a NaOH solution employing K-type layered manganese oxide as a precursor. The obtained manganese oxide nanobelt bundles exhibit excellent discharge properties and cycle stability. The initial capacity is 376 mAh-g-1 and the reversible capacity of 243 mAhog-1 is maintained after the 50th cycle at a current density of 20 mA·g-t. Meanwhile, the manganese oxide nanobelt bundles show an excellent cycle performance even if at relative high current density.
Subtleties Concerning Conformal Tractor Bundles
Graham, C Robin
2012-01-01
The realization of tractor bundles as associated bundles in conformal geometry is studied. It is shown that different natural choices of principal bundle with normal Cartan connection corresponding to a given conformal manifold can give rise to topologically distinct associated tractor bundles for the same inducing representation. Consequences for homogeneous models and conformal holonomy are described. A careful presentation is made of background material concerning standard tractor bundles and equivalence between parabolic geometries and underlying structures.
Research on the Pricing of Bundling Information Commodity%信息产品的捆绑定价问题研究
Institute of Scientific and Technical Information of China (English)
毛彦妮; 王刊良; 王龙伟
2003-01-01
This article studies the characteristics of low marginal cost of information commodity and points out that bundling information commodity is surprisingly profitable. After an analysis of the three factors affecting the sales income of bundling information commodity, that is, marginal cost, distribution of consumer' s valuation of bundling commodity and bundling size, a marketing strategy for bundling information commodity is proposed.
Cohomology of line bundles on the flag variety for type G_2
DEFF Research Database (Denmark)
Andersen, Henning Haahr; Kaneda, Masaharu
2012-01-01
In the case of a simple algebraic group G of type G2 over a field of characteristic p>0 we study the cohomology modules of line bundles on the flag variety for G. Our main result is a complete determination of the vanishing behavior of such cohomology in the case where the line bundles in question...
MENT reconstruction and potting comparison of a LMFBR fuel bundle
International Nuclear Information System (INIS)
Since the advent of computer-assisted-tomography (CAT), the CAT techniques have been rapidly expanded to the nuclear industry. A number of investigators have applied these techniques to reconstruct the fuel bundle configuration inside a subassembly with various degrees of resolution; however, there has been little data available on the accuracy of these reconstructions, and no comparisons have been made with the internal structure of actual irradiated subassemblies. Some efforts have utilized pretest mock-ups to calibrate the CAT algorithms, but the resulting mock-up configurations do not necessarily represent an actual subassembly, so an exact comparison has been lacking. The purpose of this paper is to present the results of a comparison between a CAT reconstruction of an irradiated subassembly and the destructive examination of the same subassembly
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…
Ion-irradiation-induced defects in bundles of carbon nanotubes
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.
Fracture process of a fiber bundle with strong disorder
Danku, Zsuzsa; Kun, Ferenc
2016-07-01
We investigate the effect of the amount of disorder on the fracture process of heterogeneous materials in the framework of a fiber bundle model. The limit of high disorder is realized by introducing a power law distribution of fiber strength over an infinite range. We show that on decreasing the amount of disorder by controlling the exponent of the power law the system undergoes a transition from the quasi-brittle phase where fracture proceeds in bursts to the phase of perfectly brittle failure where the first fiber breaking triggers a catastrophic collapse. For equal load sharing in the quasi-brittle phase the fat tailed disorder distribution gives rise to a homogeneous fracture process where the sequence of breaking bursts does not show any acceleration as the load increases quasi-statically. The size of bursts is power law distributed with an exponent smaller than the usual mean field exponent of fiber bundles. We demonstrate by means of analytical and numerical calculations that the quasi-brittle to brittle transition is analogous to continuous phase transitions and determine the corresponding critical exponents. When the load sharing is localized to nearest neighbor intact fibers the overall characteristics of the failure process prove to be the same, however, with different critical exponents. We show that in the limit of the highest disorder considered the spatial structure of damage is identical with site percolation—however, approaching the critical point of perfect brittleness spatial correlations play an increasing role, which results in a different cluster structure of failed elements.
Load sharing in the growth of bundled biopolymers
Wang, Ruizhe; Carlsson, A. E.
2014-01-01
To elucidate the nature of load sharing in the growth of multiple biopolymers, we perform stochastic simulations of the growth of biopolymer bundles against obstacles under a broad range of conditions and varying assumptions. The obstacle motion due to thermal fluctuations is treated explicitly. We assume the “Perfect Brownian Ratchet” (PBR) model, in which the polymerization rate equals the free-filament rate as soon as the filament-obstacle distance exceeds the monomer size. Accurate closed-form formulas are obtained for the case of a rapidly moving obstacle. We find the following: (1) load sharing is usually sub-perfect in the sense that polymerization is slower than for a single filament carrying the same average force; (2) the sub-perfect behavior becomes significant at a total force proportional to the logarithm or the square root of the number of filaments, depending on the alignment of the filaments; (3) for the special case of slow barrier diffusion and low opposing force, an enhanced obstacle velocity for an increasing number of filaments is possible; (4) the obstacle velocity is very sensitive to the alignment of the filaments in the bundle, with a staggered alignment being an order of magnitude faster than an unstaggered one at forces of only 0.5 pN per filament for 20 filaments; (5) for large numbers of filaments, the power is maximized at a force well below 1 pN per filament; (6) for intermediate values of the obstacle diffusion coefficient, the shape of the force velocity relation is very similar to that for rapid obstacle diffusion. PMID:25489273
Subchannel analysis of CANDU 37-element fuel bundles
International Nuclear Information System (INIS)
The subchannel analysis codes COBRA-IV and ASSERT-4 have been used to predict the mass and enthalpy imbalance within a CANDU 37-element fuel channel under various system conditions. The objective of this study was to assess the various capabilities of the ASSERT code and highlight areas where further validation or development may be needed. The investigation indicated that the ASSERT code has all the basic models required to accurately predict the flow and enthalpy imbalance for complex rod bundles. The study also showed that the code modelling of void drift and diffusion requires refinement to some coefficients and that further validation is needed at high flow rate and high void fraction conditions, where ASSERT and COBRA are shown to predict significantly different trends. The results of a recent refinement of ASSERT modelling are also discussed
Energy Technology Data Exchange (ETDEWEB)
Zinnbauer, M. [Ludwig-Maximilians-Universitaet Muenchen (Germany)
2001-07-01
As most of the electric utilities in Germany have decided by now to adopt the multi-utility strategy for sales promotion in the open electricity market, a questionnaire has been distributed to 1 000 households in order to find out whether product bundling or cross selling in combination with the low-interest product 'electricity' is a good strategy to enlarge the customer basis. EFOplan (Munic University) and the consulting firm Accenture have been in charge of the survey. The results show the current status of insight of household customers and their motives to change supplier, as well as the pattern of demand for product bundling. (orig./CB) [German] Da mittlerweile die meisten EVUs eine Multi-Utility-Strategie anstreben, wurde mittels einer schriftlichen Befragung von 1 000 deutschen Haushalten untersucht, ob die Vermarktung von Zusatz- bzw. Buendelprodukten in Kombination mit dem Low-Interest-Produkt Strom erfolgsversprechend ist. Die Befragung, die von EFOplan (Universitaet Muenchen) in Kooperation mit der Unternehmensberatung Accenture durchgefuehrt wurde, zeigt einerseits den aktuellen Status von Informationsstand und Wechselmotiven beim Stromkauf und andererseits die Bedarfsstruktur im Hinblick auf moegliche Buendelprodukte. (orig.)
Unwrapping the Bundle: An Examination of Research Libraries and the "Big Deal"
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,…
A simulation study on the adsorption properties of linear alkanes on closed nanotube bundles
J.J. Cannon; T.J.H. Vlugt; D. Dubbeldam; S. Maruyama; J. Shiomi
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 lengt
Modification of the Simpson moduli space M_{3m+1}(P_2) by vector bundles (I)
Iena, Oleksandr
2010-01-01
We consider the moduli space of stable vector bundles on curves embedded in P_2 with Hilbert polynomial 3m+1 and construct a compactification of this space by vector bundles. The result is a blow up of the Simpson moduli space M_{3m+1}(P_2).
Structural evaluation of a DTHR bundle divertor particle collector
International Nuclear Information System (INIS)
The purpose of this report is to present a structural evaluation of the current bundle divertor particle collector BDPC design under a peak heat flux in relation to criteria that protect against coolant leakage into the plasma over replacement schedules planned during DTHR operation. In addition, an assessment of the BDPC structural integrity at higher heat fluxes is presented. Further, recommendations for modifications in the current BDPC design that would improve design reliability to be considered in future design studies are described. Finally, experimental test programs directed to establishing materials data necessary in providing greater confidence in subsequent structural evaluations of BDPC designs in relation to coolant leakage over planned replacement schedules are identified
Flow-induced vibration of steam generator tube bundles
International Nuclear Information System (INIS)
The vibrations induced in tube arrays by a transversal flow are of great practical interest because of their destructive effects especially on heat exchangers. Instabilities can appear beyond a critical flow velocity and induce very high vibratory levels which may involve fractures. These instabilities involve a fluidelastic coupling between the vibratory movement of the tubes and the flow round them. Studies are being carried out in France concerning steam generators. A lot of bundle mock-ups with various pitches have been tested and large range parameter domains have been investigated. In a second part, the C.E.A., FRAMATOME, E.D.F. and WESTINGHOUSE research program, which is being carried out, is presented
Relationships between the Tensile Properties and Tenacity extension Behaviour of Fibre-bundles
Institute of Scientific and Technical Information of China (English)
YU Wei-dong
2002-01-01
Fibre bundle testing is different from single-fibre measurement, not only in testing methods and instruments, but in the results obtained. For wool fibres, Sirolan-TENSOR can supply fibre-bundle tenacity (BS) and bundle extension (BE), but has some limitations on the analysis of the measured tensile curves of fibre bundles. It has not only raised new parameters,such as initial modulus (BM) and specific work of rupture (BW), as well as the specific work before or after the peak-point(WBP or WAP) and the ratios of WAP/WBP and WAP/BW, but also compared the tensile behaviour of different fibre-bundles, e.g. wool,polyester and viscose rayon fibre- bundles. The experimental results from 32 lots of wool tops show that there are correlations between bundle tensile properties,such as BS-BE, BS-BM, BS-BW, BE-BW and BM-BW.However, the variables of coefficients of variance (CV)are almost independent of each other and have no correlation with the average values of fibre bundle tensile parameters, except for BS-CVBM and CVBM-BW.
Overview of flowline bundle technology from concept selection to offshore installation
Institute of Scientific and Technical Information of China (English)
Song Ruxin; Xia Qiuling
2013-01-01
Flowline bundle system consisting of carrier pipe,sleeve pipe and internal flowlines offers innovative solution for the infield transportation of oil and gas.Due to its features,flowline bundle offers a couple of advantages over conventional flowline in particular for cases where multi-flowlines and high thermal performance is of great interest.The main benefits and advantages of such system include excellent thermal performance to prevent wax formation and hydrates,multiple bundled flowlines,mechanical and corrosion protection,potential reuse,etc.With the developments of offshore oil and gas industries,more and more hydrocarbon resources are being explored and discovered from shallow to deep water.Pipeline bundle system can be a smart solution for certain applications,which can be safe and cost effective solution.The objective of this paper is to overview pipeline bundle technology,outline detailed engineering design issue and procedure.Focus is given to its potential application in offshore for infield transportation.Engineering design principles and procedures for pipeline bundle system are highlighted.Construction methods of flowline bundle onshore are reviewed.Offshore towing and installation of pipeline bundle procedure is outlined.
A Variant of K-Theory and Topological T-Duality for Real Circle Bundles
Gomi, Kiyonori
2015-03-01
For a space with involutive action, there is a variant of K-theory. Motivated by T-duality in type II orbifold string theory, we establish that a twisted version of the variant enjoys a topological T-duality for Real circle bundles, i.e., circle bundles with real structure.
Lexical Bundles in Discourse Structure: A Corpus-Based Study of Classroom Discourse
Csomay, Eniko
2013-01-01
The present study applies corpus-based methods to document the distributional patterns of previously reported lexical bundle functions as they relate to discourse structure. Specifically, 84 lexical bundles and their discourse functions (Biber "et al." 2004a) were tracked in 1,176 discourse units extracted from the initial phases of 196 university…
GPU acceleration of the stochastic grid bundling method for early-exercise options
Leitao Rodriguez, A.; Oosterlee, C.W.
2015-01-01
In 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 increased drast
Treatment, packaging, and storage of bundle scrap hardware
International Nuclear Information System (INIS)
A study was performed to identify and evaluate the various technical options for treatment, packaging and storing the bundle scrap hardware that results from rod consolidation. The three general scenarios addressed were keeping the treated scrap in the pool, moving it to on-site dry storage, or immediate disposal. The study concluded that practical alternatives existed for all three cases. Use of novel scrap packaging techniques achieved an overall net consolidation ratio of two. The most economical concept was found to be using advanced technology in the pool storage scenario with dry storage schemes a close second. The project also provides information on scrap characterization and provides tools to assist in classifying the scrap hardware
Komzák, M; Hart, R; Smíd, P; Puskeiler, M
2014-01-01
PURPOSE OF THE STUDY A comparison of the efficacy of central anatomical single-bundle (CASB) reconstruction with that of double-bundle (DB) repair of the anterior cruciate ligament (ACL) in relation to knee stability in anteroposterior translation (APT), internal rotation (IR) and external rotation (ER) of the joint. MATERIAL AND METHODS A total of 40 patients were evaluated; 20 had ACL reconstruction by the CASB technique using hamstrings and 20 underwent DB repair surgery. The average age was 31.3 years, and the group included 22 men and 18 women with 19 right and 21 left knees. The KT-1000 test was used to assess the amount of APT in the knee and rotational deviations were measured by the Rolimeter. In the DB patients, measurements were performed before surgery (on joints with ACL injury), then after reconstruction of the anteromedial (AM) or the posterolateral (PL) bundle and subsequently after repair of both ACL bundles. The CASB patients were assessed before and after graft insertion. RESULTS The average APT value was 18.5 mm for the pre-operative knees and it fell to 8.9 mm after AM bundle reconstruction. However, when the PL bundle was inserted in the first place, the average APT value was 13.1 mm only. The average values recorded after the DB and CASB reconstructions were 6.1 mm and 9.1 mm, respectively. The average IR range of motion in the pre-operative joints was 18.6 degrees. After AM bundle reconstruction it was 13.9 degrees and after PL bundle repair it was 15.3 degrees. In DB reconstruction the average IR value achieved 10.4 degrees, and in CASB repair surgery it was 13.7 degrees. The average ER range of motion in the pre-operative joints was 17.8 degrees. After AM bundle reconstruction it was 14.5 degrees and after PL bundle repair it was 14.9 degrees. In DB reconstruction the average ER value achieved 11.4 degrees, and in CASB repair surgery it was 14.5 degrees. DISCUSSION Rotational stability of the knee after ACL reconstruction is one of the
Characteristics of liquid and boiling sodium flows in heating pin bundles
International Nuclear Information System (INIS)
This study is related to cooling accidents which could occur in sodium cooled fast reactors. Thermo-hydraulic aspects of boiling experiments in pin bundles with helical wire-wrap spacer systems, in the case of undamaged geometries, are analyzed. Differences and analogies in the behavior of multi-rod bundle flows and one-dimensional channel flows are studied. A boiling model is developed for bundle geometries, and predictions obtained with the FLICA code using this models are presented. These predictions are compared with experimental results obtained in a water 19-rod bundle. Then, results of sodium boiling experiments through a 19-rod bundle are interpreted. Both cases of high power and reduced power are envisaged
THE COCHLEAR AMPLIFIER：IS IT HAIR BUNDLE MOTION OF OUTER HAIR CELLS?
Institute of Scientific and Technical Information of China (English)
LI Yi; He David Z
2014-01-01
Cochlear outer hair cells (OHCs) are involved in a mechanical feedback loop in which the fast somatic motility of OHCs is required for cochlear amplification. Alternatively, amplification is thought to arise from active hair bundle movements ob-served in non-mammalian hair cells. We measured the voltage-evoked hair bundle motions in the gerbil cochlea to determine if such movements are also present in mammalian OHCs. The OHCs displayed a large hair bundle movement that was not based on mechanotransducer channels but based on somatic motility. Significantly, bundle movements were able to generate radial motion of the tectorial membrane in situ. This result implies that the motility-associated hair bundle motion may be part of the cochlear amplifier.
Walker Calhoun: Master of His Art, Keeper of Traditions.
Hoffman, Carl
1993-01-01
During the 1920s, Walker Calhoun learned traditional songs and dances from his uncle, Will West Long, spiritual leader of the Big Cove Cherokees. Nine years ago, Calhoun began teaching them to his grandchildren and other young people. Calhoun has received numerous honors for his work to preserve Cherokee culture. (LP)
Institute of Scientific and Technical Information of China (English)
YU Wei-dong; Ron Postle; YANG Shou-ren; YAN Hao-jing
2002-01-01
The testing conditions of a fibre bundle tensile tester (TENSOR) are elongation speed (ES), gauge length (GL), pretension, jaw pressure, environmental temperature and relative humidity, instrument linearity and sensitivity. The effects on fibre-bundle tensile properties at different GL and ES have been discussed in detail and compared with Peirce's theories on the weaklinks and the breaking time effect. The experimental results indicate that the tensile properties of fibre bundles are strongly affected by GL and vary with different GL. The reasonable GL should be 5-15mm rather than 3.2mm for wool bundle measurements. The ES ranging from 20mm/min to 40mm/min is beneficial for obtaining comparatively stable and accurate tensile values, whereas 20 mm/min used in current testing for wool fibre bundles is at the lower limit of the suggested range. For bundle modulus measurement, the sampling interval must be selected appropriately. The new calculation of the sampling interval has been established.
Principal -bundles on Nodal Curves
Indian Academy of Sciences (India)
Usha N Bhosle
2001-08-01
Let be a connected semisimple affine algebraic group defined over . We study the relation between stable, semistable -bundles on a nodal curve and representations of the fundamental group of . This study is done by extending the notion of (generalized) parabolic vector bundles to principal -bundles on the desingularization of and using the correspondence between them and principal -bundles on . We give an isomorphism of the stack of generalized parabolic bundles on with a quotient stack associated to loop groups. We show that if is simple and simply connected then the Picard group of the stack of principal -bundles on is isomorphic to ⊕ , being the number of components of .
Institute of Scientific and Technical Information of China (English)
CHENG Shen; SUN Feng-zhong; SHI Yue-tao
2012-01-01
To develop an excellent heat transfer element under the vacuum condition,experiments about the heat transfer performance of horizontal tube bundles of different materials under various vacuum conditions were carried out,including the stainless steel tube,the brass tube,the Ni-based implanted steel tube and the ion implanted brass tube.The relative trends show that the condensation heat transfer coefficient and the overall heat transfer coefficient of bundles of four materials all increase with the vacuum degree,especially,those of the Ni-based implanted steel tube and the ion implanted brass tube.Under a high vacuum condition (0.07 MPa),the condensation heat transfer coefficient of the Ni-based implanted steel tube bundle is about 1.4 times of that of the stainless steel tube bundle,the condensation heat transfer coefficient of the ion implanted brass tube bundle is found to be about 1.3 times of that of the common brass tube bundle.Therefore,according to the condensation heat transfer characteristics studied under high vacuum conditions,it is believed that a dropwise condensation is partly achieved on the surface of these two implanted tube bundles,and the ion implantation is shown to be an effective method to achieve the dropwise condensation.Based on this study,it is believed that the Ni-based steel tube may replace the brass tube,which is more expensive as a heat transfer component.
Nikolai N. Anichkov and His Theory of Atherosclerosis
Konstantinov, Igor E.; Mejevoi, Nicolai; Anichkov, Nikolai M.
2006-01-01
Nikolai N. Anichkov (1885–1964) first demonstrated the role of cholesterol in the development of atherosclerosis. His classic experiments in 1913 paved the way to our current understanding of the role of cholesterol in cardiovascular disease. Anichkov's research is often cited among the greatest discoveries of the 20th century; however, little is known about Anichkov and his team. Herein, we give a detailed historical account of Anichkov's work, his personality, his research team, and their p...
Remarkable improvement of methylglyoxal synthase thermostability by His-His interaction.
Mohammadi, Malihe; Kashi, Mona Atabakhshi; Zareian, Shekufeh; Mirshahi, Manoochehr; Khajeh, Khosro
2014-01-01
Lately it has been proposed that interaction between two positively charged side chains can stabilize the folded state of proteins. To further explore this point, we studied the effect of histidine-histidine interactions on thermostability of methylglyoxal synthase from Thermus sp. GH5 (TMGS). The crystal structure of TMGS revealed that His23, Arg22, and Phe19 are in close distance and form a surface loop. Here, two modified enzymes were produced by site-directed mutagenesis (SDM); one of them, one histidine (TMGS-HH(O)), and another two histidines (TMGS-HHH(O)) were inserted between Arg22 and His23 (H(O)). In comparison with the wild type, TMGS-HH(O) thermostability increased remarkably, whereas TMGS-HHH(O) was very unstable. To explore the role of His23 in the observed phenomenon, the original His23 in TMGS-HHH(O) was replaced with Ala (TMGS-HHA). Our data showed that the half-life of TMGS-HHA decreased in relation to the wild type. However, its half-life increased in comparison with TMGS-HHH(O). These results demonstrated that histidine-histidine interactions at position 23 in TMGS-HH(O) probably have the main role in TMGS thermostability.
On the Characteristics of Gatsby and His Tragic Fate
Institute of Scientific and Technical Information of China (English)
刘媛媛
2010-01-01
This thesis mainly analyzed the characteristics of Gatsby. It disclosed the complex cheracteristics of Gatsby. The following five points were concerned: first, there was some romantic color in his characters that he believed things in the past could turn back, inclu-ding his love. Second, he was very strict with himself. Third, he was very considerate and faithful to his lover. Four, his answerving efforts and resolution to realize the dream set the example for us.
Results of international standard problem No. 36 severe fuel damage experiment of a VVER fuel bundle
Energy Technology Data Exchange (ETDEWEB)
Firnhaber, M. [Gesellschaft fuer Anlagen-und Reaktorsicherheit, Koeln (Germany); Yegorova, L. [Nuclear Safety Institute of Russian Research Center, Moscow (Russian Federation); Brockmeier, U. [Ruhr-Univ. of Bochum (Germany)] [and others
1995-09-01
International Standard Problems (ISP) organized by the OECD are defined as comparative exercises in which predictions with different computer codes for a given physical problem are compared with each other and with a carefully controlled experimental study. The main goal of ISP is to increase confidence in the validity and accuracy of analytical tools used in assessing the safety of nuclear installations. In addition, it enables the code user to gain experience and to improve his competence. This paper presents the results and assessment of ISP No. 36, which deals with the early core degradation phase during an unmitigated severe LWR accident in a Russian type VVER. Representatives of 17 organizations participated in the ISP using the codes ATHLET-CD, ICARE2, KESS-III, MELCOR, SCDAP/RELAP5 and RAPTA. Some participants performed several calculations with different codes. As experimental basis the severe fuel damage experiment CORA-W2 was selected. The main phenomena investigated are thermal behavior of fuel rods, onset of temperature escalation, material behavior and hydrogen generation. In general, the calculations give the right tendency of the experimental results for the thermal behavior, the hydrogen generation and, partly, for the material behavior. However, some calculations deviate in important quantities - e.g. some material behavior data - showing remarkable discrepancies between each other and from the experiments. The temperature history of the bundle up to the beginning of significant oxidation was calculated quite well. Deviations seem to be related to the overall heat balance. Since the material behavior of the bundle is to a great extent influenced by the cladding failure criteria a more realistic cladding failure model should be developed at least for the detailed, mechanistic codes. Regarding the material behavior and flow blockage some models for the material interaction as well as for relocation and refreezing requires further improvement.
Grant's Final Battle: The Writing of His Memoirs.
Lambert, Robert G., Jr.
In the summer of 1884, Ulysses S. Grant wrote his "Memoirs," which were published and promoted by the great American writer, Mark Twain, who encouraged and aided Grant in his literary work. Grant was fatally ill with cancer of the throat and raced against time to complete his manuscript. He was motivated by the desire to provide financial support…
De Novo Design of Metalloproteins and Metalloenzymes in a Three-Helix Bundle.
Plegaria, Jefferson S; Pecoraro, Vincent L
2016-01-01
For more than two decades, de novo protein design has proven to be an effective methodology for modeling native proteins. De novo design involves the construction of metal-binding sites within simple and/or unrelated α-helical peptide structures. The preparation of α3D, a single polypeptide that folds into a native-like three-helix bundle structure, has significantly expanded available de novo designed scaffolds. Devoid of a metal-binding site (MBS), we incorporated a 3Cys and 3His motif in α3D to construct a heavy metal and a transition metal center, respectively. These efforts produced excellent functional models for native metalloproteins/metalloregulatory proteins and metalloenzymes. Morever, these α3D derivatives serve as a foundation for constructing redox active sites with either the same (e.g., 4Cys) or mixed (e.g., 2HisCys) ligands, a feat that could be achieved in this preassembled framework. Here, we describe the process of constructing MBSs in α3D and our expression techniques.
Optical design of endoscopic shape-tracker using quantum dots embedded in fiber bundles
Eisenstein, Jessica; Gavalis, Robb; Wong, Peter Y.; Cao, Caroline G. L.
2009-08-01
Colonoscopy is the current gold standard for colon cancer screening and diagnosis. However, the near-blind navigation process employed during colonoscopy results in endoscopist disorientation and scope looping, leading to missed detection of tumors, incorrect localization, and pain for the patient. A fiber optic bend sensor, which would fit into the working channel of a colonoscope, is developed to aid navigation through the colon during colonoscopy. The bend sensor is comprised of a bundle of seven fibers doped with quantum dots (QDs). Each fiber within the bundle contains a unique region made up of three zones with differently-colored QDs, spaced 120° apart circumferentially on the fiber. During bending at the QD region, light lost from the fiber's core is coupled into one of the QD zones, inducing fluorescence of the corresponding color whose intensity is proportional to the degree of bending. A complementary metal oxide semiconductor camera is used to obtain an image of the fluorescing end faces of the fiber bundle. The location of the fiber within the bundle, the color of fluorescence, and the fluorescence intensity are used to determine the bundle's bending location, direction, and degree of curvature, respectively. Preliminary results obtained using a single fiber with three QD zones and a seven-fiber bundle containing one active fiber with two QDs (180° apart) demonstrate the feasibility of the concept. Further developments on fiber orientation during bundling and the design of a graphical user interface to communicate bending information are also discussed.
Analytical Deriving of the Field Capacity through Soil Bundle Model
Arnone, E.; Viola, F.; Antinoro, C.; Noto, L. V.
2015-12-01
The concept of field capacity as soil hydraulic parameter is widely used in many hydrological applications. Althought its recurring usage, its definition is not univocal. Traditionally, field capacity has been related to the amount of water that remains in the soil after the excess water has drained away and the water downward movement experiences a significant decresase. Quantifying the drainage of excess of water may be vague and several definitions, often subjective, have been proposed. These definitions are based on fixed thresholds either of time, pressure, or flux to which the field capacity condition is associated. The flux-based definition identifies the field capacity as the soil moisture value corresponding to an arbitrary fixed threshold of free drainage flux. Recently, many works have investigated the flux-based definition by varying either the drainage threshold, the geometry setting and mainly the description of the drainage flux. Most of these methods are based on the simulation of the flux through a porous medium by using the Darcy's law or Richard's equation. Using the above-mentioned flux-based definition, in this work we propose an alternative analytical approach for deriving the field capacity based on a bundle-of-tubes model. The pore space of a porous medium is conceptualized as a bundle of capillary tubes of given length of different radii, derived from a known distribution. The drainage from a single capillary tube is given by the analytical solution of the differential equation describing the water height evolution within the capillary tube. This equation is based on the Poiseuille's law and describes the drainage flux with time as a function of tube radius. The drainage process is then integrated for any portion of soil taking into account the tube radius distribution which in turns depends on the soil type. This methodology allows to analytically derive the dynamics of drainage water flux for any soil type and consequently to define the
Acharya, Rudresh; Carnevale, Vincenzo; Fiorin, Giacomo; Levine, Benjamin G; Polishchuk, Alexei L; Balannik, Victoria; Samish, Ilan; Lamb, Robert A; Pinto, Lawrence H; DeGrado, William F; Klein, Michael L
2010-08-24
The M2 proton channel from influenza A virus is an essential protein that mediates transport of protons across the viral envelope. This protein has a single transmembrane helix, which tetramerizes into the active channel. At the heart of the conduction mechanism is the exchange of protons between the His37 imidazole moieties of M2 and waters confined to the M2 bundle interior. Protons are conducted as the total charge of the four His37 side chains passes through 2(+) and 3(+) with a pK(a) near 6. A 1.65 A resolution X-ray structure of the transmembrane protein (residues 25-46), crystallized at pH 6.5, reveals a pore that is lined by alternating layers of sidechains and well-ordered water clusters, which offer a pathway for proton conduction. The His37 residues form a box-like structure, bounded on either side by water clusters with well-ordered oxygen atoms at close distance. The conformation of the protein, which is intermediate between structures previously solved at higher and lower pH, suggests a mechanism by which conformational changes might facilitate asymmetric diffusion through the channel in the presence of a proton gradient. Moreover, protons diffusing through the channel need not be localized to a single His37 imidazole, but instead may be delocalized over the entire His-box and associated water clusters. Thus, the new crystal structure provides a possible unification of the discrete site versus continuum conduction models.
Two-dimensional evaluation of 3D needled Cf/SiC composite fiber bundle surface
Wei, Jinhua; Lin, Bin; Cao, Xiaoyan; Zhang, Xiaofeng; Fang, Sheng
2015-11-01
The variations of fiber bundle surface microstructure have direct influence on the material performance, especially the friction and wear properties. Therefore, fiber bundle is the smallest evaluation unit of Cf/SiC composite surface. However, due to the anisotropy and inhomogeneity of Cf/SiC composite, it is difficult to evaluate the surface characteristics. Researchers think that two-dimensional evaluation is not suitable for the composites surface assessment any more because of its complex composition and varied surface structure. In this paper, a novel method is introduced for the evaluation of 3D needled Cf/SiC composite fiber bundle surface. On the level of Cf/SiC composite fiber bundle surface, two-dimensional evaluation method is adopted, with which the fiber bundle surface quality can be quantitatively evaluated by the two-dimensional surface roughness Ra. As long as the extracted surface profiles averagely distributed on Cf/SiC composite fiber bundle surface, with appropriate sampling length and sampling number, the mean value of Ra can estimate the whole surface roughness, thus reflecting the roughness degree of surface accurately. This study not only benefits the detection of 3D needled Cf/SiC composite fiber bundle surface quality, and lays a foundation on the evaluation of material functional features in further. And it corresponds to the convenient application in engineering practice.
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
Lerman, Eugene
2003-01-01
We define contact fiber bundles and investigate conditions for the existence of contact structures on the total space of such a bundle. The results are analogous to minimal coupling in symplectic geometry. The two applications are construction of K-contact manifolds generalizing Yamazaki's fiber join construction and a cross-section theorem for contact moment maps
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)
On projective space bundle with nef normalized tautological line bundle
Yasutake, Kazunori
2011-01-01
In this paper, we study the structure of projective space bundles whose relative anti-canonical line bundle is nef. As an application, we get a characterization of abelian varieties up to finite etale covering.
Principal noncommutative torus bundles
DEFF Research Database (Denmark)
Echterhoff, Siegfried; Nest, Ryszard; Oyono-Oyono, Herve
2008-01-01
action) and give necessary and sufficient conditions for any non-commutative principal torus bundle being RKK-equivalent to a commutative one. As an application of our methods we shall also give a K-theoretic characterization of those principal torus-bundles with H-flux, as studied by Mathai...... and Rosenberg which possess "classical" T-duals....
Araki, Daisuke; Kuroda, Ryosuke; Kubo, Seiji; Fujita, Norifumi; Tei, Katsumasa; Nishimoto, Koji; Hoshino, Yuichi; Matsushita, Takehiko; Matsumoto, Tomoyuki; Nagamune, Koki; Kurosaka, Masahiro
2011-03-01
We conducted a prospective randomised study of anatomical single-bundle (A-SB group) versus double-bundle (A-DB group) anterior cruciate ligament (ACL) reconstruction using the hamstrings tendons. Twenty patients with unilateral ACL deficiency were randomised into two groups. We created the bone tunnels at the position of the original insertion of the anteromedial bundle footprint and posterolateral bundle footprint in the A-DB group and at the central position between these two bundles in the A-SB group. All of the patients were tested before ACL reconstruction and one year after surgery. The KT-1000 measurements, isokinetic muscle peak torque and heel-height difference were evaluated and the general knee condition was assessed by Lysholm score. For pre- and postoperative stability assessment, we used the six-degrees-of-freedom of knee kinematic measurement system using an electromagnetic device (the EMS) for quantitative assessment during the Lachman test and the pivot shift test. There were no significant differences in the KT-1000 measurements, isokinetic muscle peak torque, heel-height difference, and Lysholm score at one-year follow-up between these two groups. The EMS data showed there were significant differences in the acceleration of the pivot shift test between the operated knee and the contralateral normal knees in the A-SB group. In conclusion, clinical outcomes were equally good in both groups. However, the EMS data showed the anatomical double-bundle ACL reconstruction tended to be biomechanically superior to the single-bundle reconstruction.
CFD analysis of flow and heat transfer in Canadian supercritical water reactor bundle
International Nuclear Information System (INIS)
Highlights: • Flow and heat transfer in SCWR fuel bundle design by AECL is studied using CFD. • Bare-rod bundle geometry is tested at 23.5, 25 and 28 MPa using STAR-CCM+ code. • SST k–ω low-Re model was used to study occurrence of heat transfer deterioration. - Abstract: Within the Gen-IV International Forum, AECL is leading the effort in developing a conceptual design for the Canadian SCWR. AECL proposed a new fuel bundle design with two rings of fuel elements placed between central flow tube and the pressure tube. In line with the scope of the conceptual design, the objective of the present CFD work is to aid in developing a bundle heat transfer correlation for the Canadian SCWR fuel bundle design. This paper presents results from an ongoing effort in determining the conditions favorable for occurrence of HTD in the supercritical bundle flows. In the current investigation, bare-rod bundle geometry was tested for the proposed fuel bundle design at 23.5, 25 and 28 MPa using STAR-CCM+ CFD code. Taking advantage of the design symmetry of the fuel bundle, only 1/32 of the computational domain was simulated. The low-Reynolds number modification of SST k–ω turbulence model along with y+ < 1 was used in the simulations. For lower mass flow simulations, the increase of inlet temperature and operational pressure was found effective in reducing the occurrence of HTD. For higher mass flow simulations, normal heat transfer behaviour was observed except for the lower pressure range (23.5 MPa)
Darwin on the Treatment of Animals: His Thoughts Then and His Influence Now
Directory of Open Access Journals (Sweden)
Dr. Donna Yarri
2013-06-01
Full Text Available Charles Darwin’s theory of evolution has seriously challenged traditional religious views on the origins of life, as well as on our human-animal similarities. Darwin is often referenced in literature on animal ethics with regard to his contention that the difference between humans and other animals is one of degree rather than of kind. This paper posits that Darwin’s writings and theory make more positive contributions to the contemporary debate on animal ethics than for which he has previously been given credit. This paper addresses important aspects of Darwin’s theory for understanding our relationship with other animals and the implications for their subsequent treatment. First, this paper considers themes in Darwin’s original writings regarding relationships among different species; second, enhancements to his theory in support of these themes; and third, recommendations for how these themes can and should inform our moral reasoning and successive treatment of other animals.
The Shape of a Ponytail and the Statistical Physics of Hair Fiber Bundles
Goldstein, Raymond E.; Warren, Patrick B.; Ball, Robin C.
2012-02-01
From Leonardo to the Brothers Grimm our fascination with hair has endured in art and science. Yet, a quantitative understanding of the shapes of a hair bundles has been lacking. Here we combine experiment and theory to propose an answer to the most basic question: What is the shape of a ponytail? A model for the shape of hair bundles is developed from the perspective of statistical physics, treating individual fibers as elastic filaments with random intrinsic curvatures. The combined effects of bending elasticity, gravity, and bundle compressibility are recast as a differential equation for the envelope of a bundle, in which the compressibility enters through an ``equation of state.'' From this, we identify the balance of forces in various regions of the ponytail, extract the equation of state from analysis of ponytail shapes, and relate the observed pressure to the measured random curvatures of individual hairs.
Balanced metrics and chow stability of projective bundles over Riemann surfaces
Seyyedali, Reza
2010-01-01
In 1980, I. Morrison proved that slope stability of a vector bundle of rank $2$ over a compact Riemann surface implies Chow stability of the projectivization of the bundle with respect to certain polarizations. We generalized Morrison's result to higher rank vector bundles over compact algebraic manifolds of arbitrary dimension that admit constant scalar curvature metric and have discrete automorphism group. In this article, we give a simple proof for polarizations $\\mathcal{O}_{\\mathbb{P}E^*}(d)\\otimes \\pi^* L^k$, where $d$ is a positive integer, $k \\gg 0$ and the base manifold is a compact Riemann surface of genus $g \\geq 2$.
Poincar\\'e Families of G-Bundles on a curve
Biswas, Indranil
2010-01-01
Let G be a reductive group over an algebraically closed field k. Consider the moduli space of stable principal G-bundles on a smooth projective curve C over k. We give necessary and sufficient conditions for the existence of Poincar\\'e bundles over open subsets of this moduli space, and compute the orders of the corresponding obstruction classes. This generalizes the previous results of Newstead, Ramanan and Balaji-Biswas-Nagaraj-Newstead to all reductive groups, to all topological types of bundles, and also to all characteristics.
Institute of Scientific and Technical Information of China (English)
Jinxun Wang; Mingzhe Dong; Jun Yao
2012-01-01
Analytical expressions of relative permeability are derived for an interacting cylindrical tube bundle model.Equations for determining relative permeability curves from both the interacting uniform and interacting serial types of triangular tube bundle models are presented.Model parameters affecting the trend of relative permeability curves are discussed.Interacting triangular tube bundle models are used to history-match laboratory displacement experiments to determine the relative permeability curves of actual core samples.By adjusting model parameters to match the history of oil production and pressure drop,the estimated relative permeability curves provide a connection between the macroscopic flow behavior and the pore-scale characteristics of core samples.
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.)
Spacetime foam induced collective bundling of intense fields
Oniga, Teodora; Wang, Charles H.-T.
2016-09-01
The influence of spacetime foam on a broad class of bosonic fields with arbitrary numbers of particles in the low-energy regime is investigated. Based on a recently formulated general description of open quantum gravitational systems, we analyze the propagation of scalar, electromagnetic, and gravitational waves on both long and short time scales with respect to their mean frequencies. For the long time propagation, the Markov approximation that neglects the effects of initial conditions of these waves is employed. In this case, despite intuitively expected decoherence and dissipation from the noisy spacetime, we show that such phenomena turn out to be completely suppressed for scalar bosons, photons, and gravitons, which are coupled to gravity but otherwise free. The short time effects are then recovered through the transient non-Markovian evolution. Focusing on scalar bosons in initially incoherent states, we find that the resulting quantum dissipation depends strongly on the distribution of the particle momentum states. We further identify a hitherto undiscovered collective antidissipation mechanism for a large number of particles. The surprising new effect tends to "bundle" identical particles within sharply distributed momentum states having a width inversely proportional to the particle number due to the thermal fluctuations, or its square root due to the vacuum fluctuations of spacetime.
Subchannel thermal-hydraulic modeling of an APT tungsten target rod bundle
Energy Technology Data Exchange (ETDEWEB)
Hamm, L.L.; Shadday, M.A. Jr.
1997-09-01
The planned target for the Accelerator Production of Tritium (APT) neutron source consists of an array of tungsten rod bundles through which D{sub 2}O coolant flows axially. Here, a scoping analysis of flow through an APT target rod bundle was conducted to demonstrate that lateral cross-flows are important, and therefore subchannel modeling is necessary to accurately predict thermal-hydraulic behavior under boiling conditions. A local reactor assembly code, FLOWTRAN, was modified to model axial flow along the rod bundle as flow through three concentric heated annular passages.
Twisted Vector Bundles on Pointed Nodal Curves
Indian Academy of Sciences (India)
Ivan Kausz
2005-05-01
Motivated by the quest for a good compactification of the moduli space of -bundles on a nodal curve we establish a striking relationship between Abramovich’s and Vistoli’s twisted bundles and Gieseker vector bundles.
Studies of a larger fuel bundle for the ABWR improved evolutionary reactor
International Nuclear Information System (INIS)
Studies for an Improved Evolutionary Reactor (IER) based on the Advanced Boiling Water Reactor (ABWR) were initiated in 1990. The author summarizes the current status of the core and fuel design. A core and fuel design based on a BWR K-lattice fuel bundle with a pitch larger than the conventional BWR fuel bundle pitch is under investigation. The core and fuel design has potential for improved core design flexibility and improved reactor transient response. Furthermore, the large fuel bundle, coupled with a functional control rod layout, can achieve improvement of operation and maintenance, as well as improvement of overall plant economy
Invariants of Velocities, and Higher Order Grassmann Bundles
Grigore, D R; Grigore, Dan Radu; Krupka, Demeter
1997-01-01
An $(r,n)$-velocity is an $r$-jet with source at $0 \\in \\R^n$, and target in a manifold $Y$. An $(r,n)$-velocity is said to be regular, if it has a representative which is an immersion at $0 \\in \\R^{n}$. The manifold $T^{r}_{n}Y$ of $(r,n)$-velocities as well as its open, $L^{r}_{n}$-invariant, dense submanifold $\\Imm T^{r}_{n}Y$ of regular $(r,n)$-velocities, are endowed with a natural action of the differential group $L^{r}_{n}$ of invertible $r$-jets with source and target $0 \\in \\R^{n}$. In this paper, we describe all continuous, $L^{r}_{n}$-invariant, real-valued functions on $T^{r}_{n}Y$ and T^{r}_{n}Y$ in an explicit, recurrent form. To this purpose, higher order Grassmann bundles are considered as the corresponding quotients $P^{r}_{n}Y = that nontrivial $L^{r}_{n}$-invariants on $\\Imm T^{r}_{n}Y$ cannot be continuously extended onto $T^{r}_{n}Y$.
Structural Analysis of Lexical Bundles in University Lectures of Politics and Chemistry
Directory of Open Access Journals (Sweden)
Hadi Kashiha
2014-01-01
Full Text Available Referred to as extended collocations, lexical bundles are considered as a main factor in building fluency in academic discourse; helping to shape meaning and coherence in a text or speech. For decades, lexical bundles have attracted considerable amount of attention in corpus-based research in English for Academic Purposes (EAP. While, the focus of the most of the studies on lexical bundles was to explore the use of these multi-word expressions in academic written registers such as research articles, academic spoken registers such as university lectures have not received that amount of attention from the scholars. In this vein, there is still an open question of how they are structurally different across disciplines. With these concerns in mind, this study aimed to explore how lexical bundles are used structurally in a 50291 words corpus of 8 university lectures across two disciplines: chemistry and politics. To this aim, the most frequent four-word bundles in the corpus were classified according to their grammatical types to see the possible disciplinary variations in their frequency of use as well as the structure involved in their use. Results of the analysis revealed that noun phrase and prepositional phrase fragments were the most common structures in the lectures of the two disciplines, accounting for more than half of the bundles in politics. University lecturers appear to apply a variety of structures in the use of lexical bundles often peculiar to the discipline in order to convey their disciplinary messages. This would lead to the need to emphasize the instruction of the most common structures in that discipline in a way for the lectures to be as comprehensive as possible for the intended audiences.Keywords: Academic lectures, academic registers, lexical bundles
Total evaluation of in bundle void fraction measurement test of PWR fuel assembly
International Nuclear Information System (INIS)
Nuclear Power Engineering Corporation is performing the various proof or verification tests on safety and reliability of nuclear power plants under the sponsorship of the Ministry of International Trade and Industry. As one program of these Japanese national projects, an in bundle void fraction measurement test of a pressurized water reactor (PWR) fuel assembly was started in 1987 and finished at the end of 1994. The experiments were performed using the 5 x 5 square array rod bundle test sections. The rod bundle test section simulates the partial section and full length of a 17 x 17 type Japanese PWR fuel assembly. A distribution of subchannel averaged void fraction in a rod bundle test section was measured by the gamma-ray attenuation method using the stationary multi beam systems. The additional single channel test was performed to obtain the required information for the calibration of the rod bundle test data and the assessment of the void prediction method. Three test rod bundles were prepared to analyze an axial power distribution effect, an unheated rod effect, and a grid spacer effect. And, the obtained data were used for the assessment of the void prediction method relevant to the subchannel averaged void fraction of PWR fuel assemblies. This paper describes the outline of the experiments, the evaluation of the experimental data and the assessment of void prediction method
Shatz, Lisa F
2004-09-01
The effect of the size and the shape of the hair bundle of a hair cell in the inner ear of non-mammals on its motion for the full range of frequencies is determined thereby extending the results of a previous analysis of hair bundle motion for high and low frequencies [Hear Res. 141 (2000) 39-50]. A hemispheroid is used to represent the hair bundle because it can represent a full range of shapes, from thin, pencil-like shapes to wide, flat, disk-like shapes. Boundary element methods are used to approximate the solution for the hydrodynamics. For physiologically relevant parameters, an excellent match is obtained between the model's predictions and measurements of hair bundle motion in the free-standing region of the basilar papilla of the alligator lizard [Aranyosi, Measuring sound-induced motions of the alligator lizard cochlea. Massachusetts Institute of Technology, PhD Thesis, 2002]. Neither in the model's predictions nor in experimental measurements is sharp tuning observed. The model predicted the low frequency region of neural tuning curves for the alligator lizard and bobtail lizard, but could not predict the sharp tuning or the high frequency region. An element that represents an active mechanism is added to the hair bundle model to predict neural tuning curves, which are sharply tuned, and an excellent match is obtained for all the characteristics of neural tuning curves for the alligator lizard, and for the low and high frequency regions for the bobtail lizard. The model does not predict well the sharp tuning of the shorter hair bundles of the bobtail lizard, possibly because it does not represent tectorial sallets.
Properties of the microcirculation in capillary bundles of rat spinotrapezius muscle fascia
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.
On framed quantum principal bundles
Durdevic, M
1995-01-01
A noncommutative-geometric formalism of framed principal bundles is sketched, in a special case of quantum bundles (over quantum spaces) possessing classical structure groups. Quantum counterparts of torsion operators and Levi-Civita type connections are analyzed. A construction of a natural differential calculus on framed bundles is described. Illustrative examples are presented.
Tangent-bundle approach for the factorization of gauge theories in a supergroup manifold
International Nuclear Information System (INIS)
Gauge theories of gravity and supergravity on a supergroup manifold are analysed as geometrical theories on the tangent bundle to a supergroup manifold. The factorization condition is considered from this point of view
Tangent-bundle approach for the factorization of gauge theories in a supergroup manifold
Energy Technology Data Exchange (ETDEWEB)
Foussats, A.; Laura, R.; Zandron, O.
1986-03-11
Gauge theories of gravity and supergravity on a supergroup manifold are analysed as geometrical theories on the tangent bundle to a supergroup manifold. The factorization condition is considered from this point of view.
Stochastic poisson equations associated to lie algebroids and some refinements of a principal bundle
Ivan, Gheorghe
2010-01-01
The aim of this paper is to present the stochastic Poisson equations associated to Lie algebroids. The stochastic Poisson equations associated to a refinement of a concrete principal bundle are determined.
Flow-induced vibration and acoustic behaviour of CANFLEX-LVRF bundles in a Bruce B NGS fuel channel
International Nuclear Information System (INIS)
Frequency/temperature sweep tests were performed in a high-temperature/high-pressure test channel to determine the acoustic and flow-induced vibration characteristics of the CANFLEX-LVRF bundle. The vibratory response of CANFLEX-LVRF bundles was compared with that of 37-element fuel bundles under Bruce B NGS fuel channel normal operating conditions. The tests were performed with a 12-bundle string of CANFLEX-LVRF bundles as well as a mixed string for the transition core. The tests showed that the LVRF bundles performed as required without failure or gross geometry changes. The mixed fuel strings behaved in a manner similar to that of a string of CANFLEX-LVRF bundles. (author)
Simulation of flow across complicated domain between tube bundles by the discrete vortex method
Institute of Scientific and Technical Information of China (English)
无
2003-01-01
On the basis of the analysis of numerical simulation methods for the complicated domain between tube bundles, an improved Lagragian discrete vortex method (DVM) and corresponding algorithm are put forward to solve the practical difficulties of flow across tube bundles. With this method the amount of vortices can be reduced considerably, which makes quick calculation possible. Applied to the practical configuration of horizontal tube bundles, the DVM simulation is carried out and compared with the experimental results. Both the transient flow field and the profile of mean velocity and fluctuations are in good agreement with experimental results, which indicate that the DVM is suitable for the simulation of single-phase flow across tube bundles.
Dressed elliptic genus of heterotic compactifications with torsion and general bundles
Israël, Dan; Sarkis, Matthieu
2016-08-01
We define and compute the dressed elliptic genus of N=2 heterotic compactifications with torsion that are principal two-torus bundles over a K3 surface. We consider a large class of gauge bundles compatible with supersymmetry, consisting of a stable holomorphic vector bundle over the base together with an Abelian bundle over the total space, generalizing the computation previously done by the authors in the absence of the latter. Starting from a (0,2) gauged linear sigma-model with torsion we use supersymmetric localization to obtain the result. We provide also a mathematical definition of the dressed elliptic genus as a modified Euler characteristic and prove that both expressions agree for hypersurfaces in weighted projective spaces. Finally we show that it admits a natural decomposition in terms of N=4 superconformal characters, that may be useful to investigate moonshine phenomena for this wide class of N=2 vacua, that includes K3 × T 2 compactifications as special cases.
Method of fabricating high-density hermetic electrical feedthroughs using insulated wire bundles
Energy Technology Data Exchange (ETDEWEB)
Shah, Kedar G.; Benett, William J.; Pannu, Satinderpall S.
2016-05-10
A method of fabricating electrical feedthroughs coats of a plurality of electrically conductive wires with an electrically insulating material and bundles the coated wires together in a substantially parallel arrangement. The bundled coated wires are secured to each other by joining the electrically insulating material of adjacent wires together to form a monolithic block which is then cut transverse to the wires to produce a block section having opposing first and second sides with a plurality of electrically conductive feedthroughs extending between them.
Scalar curvature and asymptotic Chow stability of projective bundles and blowups
Della Vedova, Alberto
2010-01-01
The holomorphic invariants introduced by Futaki as obstruction to the asymptotic Chow semistability are studied by an algebraic-geometric point of view and are shown to be the Mumford weights of suitable line bundles on the Hilbert scheme. These invariants are calculated in two special cases. The first is a projective bundle over a curve of genus at least two, and it is shown that it is asymptotically Chow polystable (with every polarization) if and only the underlying vector bundle is slope polystable. This proves a conjecture of Morrison with the extra assumption that the involved polarization is sufficiently divisible. Moreover it implies that a projective bundle is asymptotically Chow polystable (with every polarization) if and only if it admits a constant scalar curvature Kaehler metric. The second case is a manifold blown-up at points, and new examples of asymptotically Chow unstable constant scalar curvature Kaehler classes are given.
Energy Band Gap Study of Semiconducting Single Walled Carbon Nanotube Bundle
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 the electron density for an 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 closest neighbours 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%.
Behavior of mixed-oxide fuel elements in a tight bundle under duty-cycle conditions
International Nuclear Information System (INIS)
The irradiation behavior of the TOB-10 fuel pins was comparable with that obtained in the single pin tests. There was no significant effect that could be directly attributed to tight bundle configuration. The postirradiation examination data provided information on the axial migration of cesium and its effect on cladding strain. Severe fuel/cladding chemical interaction (FCCI), which resulted in substantial cladding thinning and probably restricted venting of fission gas from the fuel column into the pin plena, apparently caused the earlier-than-expected cladding breaches in the D9-clad pins. No such severe FCCI was noted in the 316SS-clad pins. At the time of test termination, the overall cladding strain from creep and swelling was insufficient to cause bundle closure. Consequently, there would have been minimal pin bundle-duct interaction in the subassembly. Neither of the breaches appeared to be induced by pin bundle-duct interaction. (author)
Research reactor fuel bundle design review by means of hydrodynamic testing
International Nuclear Information System (INIS)
During the design steps of a fuel bundle for a nuclear reactor, some vibration tests are usually necessary to verify the prototype dynamical response characteristics and the structural integrity. To perform these tests, the known hydrodynamic loop facilities are used to evaluate the vibrational response of the bundle under the different flow conditions that may appear in the reactor. This paper describes the tests performed on a 19 plate fuel bundle prototype designed for a low power research reactor. The tests were done in order to know the dynamical characteristics of the plates and also of the whole bundle under different flow rate conditions. The paper includes a description of the test facilities and the results obtained during the dynamical characterization tests and some preliminary comments about the tests under flowing water are also presented. (author)
Dressed elliptic genus of heterotic compactifications with torsion and general bundles
Israel, Dan
2016-01-01
We define and compute the dressed elliptic genus of N = 2 heterotic compactifications with torsion that are principal two-torus bundles over a K3 surface. We consider the most general gauge bundle compatible with supersymmetry, a stable holomorphic vector bundle over the base together with an Abelian bundle over the total space, generalizing the computation previously done by the authors in the absence of the latter. Starting from a (0,2) gauged linear sigma-model with torsion we use supersymmetric localization to obtain the result. We provide also a mathematical definition of the dressed elliptic genus as a modified Euler characteristic and prove that both expressions agree for hypersurfaces in weighted projective spaces. Finally we show that it admits a natural decomposition in terms of N = 4 superconformal characters, that may be useful to investigate moonshine phenomena for this wide class of N = 2 vacua, that includes K3*T2 compactifications as special cases.
CFD simulation of critical heat flux in a rod bundle
International Nuclear Information System (INIS)
The critical heat flux (CHF) condition is characterized by a sharp reduction of the local heat transfer coefficient which results from the replacement of liquid by vapour adjacent to the heat transfer surface. If the surface heat flux is the independent variable, the condition manifests itself as a sharp increase in surface temperature as the critical heat flux value is reached. The critical heat flux forms an important boundary for the performance of the heat exchange equipment. Determination of the critical heat flux is one of the key issues in nuclear reactor safety. This paper presents numerical simulations of boiling flow in a rod bundle with Departure from Nucleate Boiling (DNB) condition at the end of the middle rod. Large Water Loop CHF tests were used as a data set for our simulations. The Large Water Loop (LWL) is non-active pressurised-water equipment with technological and thermal parameters corresponding to those of PWR. The CHF experimental facility (a part of the Large Water Loop) has been designed for research into CHF in water flow through a bundle of electrically heated vertical rods. The critical conditions were determined under constant pressure, inlet water temperature and mass flux and for quasi steady-state - by gradually increasing the heat input. The rods are modelled by hollow tubes with direct heating of the wall. NEPTUNE-CFD code was used for numerical simulations. The computational domain covered a 30 deg. quasi-symmetric section of the actual channel. Simplified grid spacers were included in the domain. Calculations were performed with two-fluid approach with models for drag, lift, added mass and turbulent dispersion forces as well as for interfacial heat and mass transfer. Turbulent dispersion coefficient was based on void fraction gradient and on drag and mass forces. K-epsilon model was used for the prediction of the liquid turbulence, the flow of vapour was assumed to be laminar. Generalized wall heat-flux-splitting model was used
Paul Dirac and the Pervasiveness of His Thinking
Olive, David I.
2003-01-01
I shall use a few personal reminiscences of my time as a student and colleague of Dirac in Cambridge to introduce some reflections on the nature of research in theoretical physics. I shall discuss and illustrate the approach of Dirac to his own research and the pervasiveness of the influence his example has provided. I shall discuss how ideas produced at all stages of his career have proved to be extraordinarily visionary, still motivating and exerting an influence on research many years afte...
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)
Sperm bundle and reproductive organs of carabid beetles tribe Pterostichini (Coleoptera: Carabidae)
Sasakawa, Kôji
2007-05-01
The morphological characteristics of sperm and reproductive organs may offer clues as to how reproductive systems have evolved. In this paper, the morphologies of the sperm and male reproductive organs of carabid beetles in the tribe Pterostichini (Coleoptera: Carabidae) are described, and the morphological associations among characters are examined. All species form sperm bundles in which the head of the sperm was embedded in a rod-shaped structure, i.e., spermatodesm. The spermatodesm shape (left-handed spiral, right-handed spiral, or without conspicuous spiral structure) and the condition of the sperm on the spermatodesm surface (with the tail free-moving or forming a thin, sheetlike structure) vary among species. In all species, the spiral directions of the convoluted seminal vesicles and vasa deferentia are the same on both sides of the body; that is, they show an asymmetric structure. The species in which the sperm bundle and the seminal vesicles both have a spiral structure could be classified into two types, with significant differences in sperm-bundle length between the two types. The species with a sperm-bundle spiral and seminal-vesicle spiral of almost the same diameter have longer sperm bundles than the species with a sperm-bundle spiral and seminal-vesicle tube of almost the same diameter. In the former type, the spiral directions of the sperm bundles and seminal vesicles are inevitably the same, whereas they differ in some species with the later type. Therefore, increased sperm bundle length appears to have been facilitated by the concordance of the sperm bundle’s coiling direction with the coiling direction of the seminal vesicle.
Hua operator on vector bundle: Application to AdS/CFT correspondence of Dirac fields
Institute of Scientific and Technical Information of China (English)
LU; Qikeng
2005-01-01
Hua's theory of harmonic functions on classical domains is generalized to the theory on holomorphic vector bundles over classical domains and further on vector bundles over the real classical domains and quaternion classical domains. In case of the simplest quaternion classical domain there is a relation between Hua operator and Dirac operator,by which an AdS/CFT correspondence of Dirac fields is established.
On the Geometry of the (1,1)-Tensor Bundle with Sasaki Type Metric
Institute of Scientific and Technical Information of China (English)
Arif SALIMOV; Aydin GEZER
2011-01-01
Curvature properties are studied for the Sasaki metric on the (1,1) tensor bundle of a Riemannian manifold. As an application, examples of almost para-Nordenian and para-K(a)hler-Nordenian B-metrics are constructed on the (1,1) tensor bundle by looking at the Sasaki metric. Also, with respect to the para-Nordenian B-structure, paraholomorphic conditions for the complete lifts of vector fields are analyzed.
Dirac method and symplectic submanifolds in the cotangent bundle of a factorizable Lie group
Capriotti, S.; Montani, H.
2011-07-01
We study some symplectic submanifolds in the cotangent bundle of a factorizable Lie group defined by second class constraints. By applying the Dirac method, we study many issues of these spaces as fundamental Dirac brackets, symmetries, and collective dynamics. As the main application, we study integrable systems on these submanifolds as inherited from a system on the whole cotangent bundle, meeting in a natural way with the Adler-Kostant-Symes theory of integrability.
The moduli space of heterotic line bundle models: a case study for the tetra-quadric
Energy Technology Data Exchange (ETDEWEB)
Buchbinder, Evgeny I. [The University of Western Australia,35 Stirling Highway, Crawley WA 6009 (Australia); Constantin, Andrei; Lukas, Andre [Rudolf Peierls Centre for Theoretical Physics, Oxford University,1 Keble Road, Oxford, OX1 3NP (United Kingdom)
2014-03-05
It has recently been realised that polystable, holomorphic sums of line bundles over smooth Calabi-Yau three-folds provide a fertile ground for heterotic model building. Large numbers of phenomenologically promising such models have been constructed for various classes of Calabi-Yau manifolds. In this paper we focus on a case study for the tetra-quadric — a Calabi-Yau hypersurface embedded in a product of four ℂℙ{sup 1} spaces. We address the question of finiteness of the class of consistent and physically viable line bundle models constructed on this manifold. Further, for a specific semi-realistic example, we explore the embedding of the line bundle sum into the larger moduli space of non-Abelian bundles, both by means of constructing specific polystable non-Abelian bundles and by turning on VEVs in the associated low-energy theory. In this context, we explore the fate of the Higgs doublets as we move in bundle moduli space. The non-Abelian compactifications thus constructed lead to SU(5) GUT models with an additional global B−L symmetry. The non-Abelian compactifications inherit many of the appealing phenomenological features of the Abelian model, such as the absence of dimension four and dimension five operators triggering fast proton decay.
Darwin on the Treatment of Animals: His Thoughts Then and His Influence Now
Dr. Donna Yarri; Dr. Spencer S. Stober
2013-01-01
Charles Darwin’s theory of evolution has seriously challenged traditional religious views on the origins of life, as well as on our human-animal similarities. Darwin is often referenced in literature on animal ethics with regard to his contention that the difference between humans and other animals is one of degree rather than of kind. This paper posits that Darwin’s writings and theory make more positive contributions to the contemporary debate on animal ethics than for which he has previous...
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.
Measurement and CFD calculation of spacer loss coefficient for a tight-lattice fuel bundle
International Nuclear Information System (INIS)
Highlights: • Experiment and CFD analysis evaluated the pressure drop in a spacer grid. • The measurement and CFD errors for the spacer loss coefficient were estimated. • The spacer loss coefficient for the dual-cooled annular fuel bundle was determined. • The CFD prediction agrees with the measured spacer loss coefficient within 8%. - Abstract: An experiment and computational fluid dynamics (CFD) analysis were performed to evaluate the pressure drop in a spacer grid for a dual-cooled annular fuel (DCAF) bundle. The DCAF bundle for the Korean optimum power reactor (OPR1000) is a 12 × 12 tight-lattice rod array with a pitch-to-diameter ratio of 1.08 owing to a larger outer diameter of the annular fuel rod. An experiment was conducted to measure the pressure drop in spacer grid for the DCAF bundle. The test bundle is a full-size 12 × 12 rod bundle with 11 spacer grid. The test condition covers a Reynolds number range of 2 × 104–2 × 105 by changing the temperature and flow rate of water. A CFD analysis was also performed to predict the pressure drop through a spacer grid using the full-size and partial bundle models. The pressure drop and loss coefficient of a spacer grid were predicted and compared with the experimental results. The CFD predictions of spacer pressure drop and loss coefficient agree with the measured values within 8%. The spacer loss coefficient for the DCAF bundle is estimated to be approximately 1.50 at a nominal operating condition of OPR1000, i.e., Re = 4 × 105
The Moduli Space of Heterotic Line Bundle Models: a Case Study for the Tetra-Quadric
Buchbinder, Evgeny I; Lukas, Andre
2014-01-01
It has recently been realised that polystable, holomorphic sums of line bundles over smooth Calabi-Yau three-folds provide a fertile ground for heterotic model building. Large numbers of phenomenologically promising such models have been constructed for various classes of Calabi-Yau manifolds. In this paper we focus on a case study for the tetra-quadric - a Calabi-Yau hypersurface embedded in a product of four CP1 spaces. We address the question of finiteness of the class of consistent and physically viable line bundle models constructed on this manifold. Further, for a specific semi-realistic example, we explore the embedding of the line bundle sum into the larger moduli space of non-Abelian bundles, both by means of constructing specific polystable non-Abelian bundles and by turning on VEVs in the associated low-energy theory. In this context, we explore the fate of the Higgs doublets as we move in bundle moduli space. The non-Abelian compactifications thus constructed lead to SU(5) GUT models with an addit...
Manufacturing of 37-element fuel bundles for PHWR 540 - new approach
Energy Technology Data Exchange (ETDEWEB)
Arora, U.K.; Sastry, V.S.; Banerjee, P.K.; Rao, G.V.S.H.; Jayaraj, R.N. [Nuclear Fuel Complex, Dept. Atomic Energy, Government of India, Hyderabad (India)
2003-07-01
Nuclear Fuel Complex (NFC), established in early seventies, is a major industrial unit of Department of Atomic Energy. NFC is responsible for the supply of fuel bundles to all the 220 MWe PHWRs presently in operation. For supplying fuel bundles for the forthcoming 540 MWe PHWRs, NEC is dovetailing 37-element fuel bundle manufacturing facilities in the existing plants. In tune with the philosophy of self-reliance, emphasis is given to technology upgradation, higher customer satisfaction and application of modern quality control techniques. With the experience gained over the years in manufacturing 19-element fuel bundles, NEC has introduced resistance welding of appendages on fuel tubes prior to loading of UO{sub 2} pellets, use of bio-degradable cleaning agents, simple diagnostic tools for checking the equipment condition, on line monitoring of variables, built-in process control methods and total productive maintenance concepts in the new manufacturing facility. Simple material handling systems have been contemplated for handling of the fuel bundles. This paper highlights the flow-sheet adopted for the process, design features of critical equipment and the methodology for fabricating the 37-element fuel bundles, 'RIGHT FIRST TIME'. (author)
Manufacturing of 37-element fuel bundles for PHWR 540 - new approach
International Nuclear Information System (INIS)
Nuclear Fuel Complex (NFC), established in early seventies, is a major industrial unit of Department of Atomic Energy. NFC is responsible for the supply of fuel bundles to all the 220 MWe PHWRs presently in operation. For supplying fuel bundles for the forthcoming 540 MWe PHWRs, NEC is dovetailing 37-element fuel bundle manufacturing facilities in the existing plants. In tune with the philosophy of self-reliance, emphasis is given to technology upgradation, higher customer satisfaction and application of modern quality control techniques. With the experience gained over the years in manufacturing 19-element fuel bundles, NEC has introduced resistance welding of appendages on fuel tubes prior to loading of UO2 pellets, use of bio-degradable cleaning agents, simple diagnostic tools for checking the equipment condition, on line monitoring of variables, built-in process control methods and total productive maintenance concepts in the new manufacturing facility. Simple material handling systems have been contemplated for handling of the fuel bundles. This paper highlights the flow-sheet adopted for the process, design features of critical equipment and the methodology for fabricating the 37-element fuel bundles, 'RIGHT FIRST TIME'. (author)
Global analysis of bundle behavior in pressurized water reactor specific CORA experiments
International Nuclear Information System (INIS)
At Kernforschungszentrum Karlsruhe, out-of-pile bundle experiments are performed in the CORA facility to investigate the behavior of light water reactor fuel elements during severe fuel damage accidents. To analyze the phenomena observed during the tests, such as claddin failure, oxidation, and deformation, as well as their influence on the post test bundle state, four pressurized water reactor specific tests are selected: CORA-2, CORA-3, CORA-5, and CORA-12. From each of these tests, a detailed global analysis using all the measured temperatures, pressures, and fluid compositions as well as videoscope information has been performed. To describe the post test bundle state quantitatively, axial profiles of the bundle cross-section area, the damage state of the rods, the average cladding oxidation, and the damage to the pellets are measured. The effects of CORA-specific components on the bundle melt progression and the measured axial profiles are identified and assessed. Most of the observations during the tests as well as the post test bundle state can be explained by the established common sequence of phenomena. For a better understanding of the melt progression, some physical phenomena, such as the energy release associated with the double-sided oxidation of the cladding, the melt release, or the melt relocation, must be analyzed in detail
Clifford Malcolm: Glimpses of His South African Legacy of Hope
Govender, Nadaraj; Ramsuran, Anitha; Dhunpath, Rubby
2008-01-01
This article reviews the contributions of Cliff Malcolm while in South Africa during the period 1997-2005. It focuses on his contribution to the fields of science education, teacher education, learner-centered education, transformational outcomes-based education and HIV/AIDS education. In this paper we provide snapshots of his work as an academic,…
The impact of Lean bundles on hospital performance: does size matter?
Al-Hyari, Khalil; Abu Hammour, Sewar; Abu Zaid, Mohammad Khair Saleem; Haffar, Mohamed
2016-10-10
Purpose The purpose of this paper is to study the effect of the implementation of Lean bundles on hospital performance in private hospitals in Jordan and evaluate how much the size of organization can affect the relationship between Lean bundles implementation and hospital performance. Design/methodology/approach The research is considered as quantitative method (descriptive and hypothesis testing). Three statistical techniques were adopted to analyse the data. Structural equation modeling techniques and multi-group analysis were used to examine the research's hypothesis, and to perform the required statistical analysis of the data from the survey. Reliability analysis and confirmatory factor analysis were used to test the construct validity, reliability and measurement loadings that were performed. Findings Lean bundles have been identified as an effective approach that can dramatically improve the organizational performance of private hospitals in Jordan. Main Lean bundles - just in time, human resource management, and total quality management are applicable to large, small and medium hospitals without significant differences in advantages that depend on size. Originality/value According to the researchers' best knowledge, this is the first research that studies the impact of Lean bundles implementation in healthcare sector in Jordan. This research also makes a significant contribution for decision makers in healthcare to increase their awareness of Lean bundles. PMID:27671423
The impact of Lean bundles on hospital performance: does size matter?
Al-Hyari, Khalil; Abu Hammour, Sewar; Abu Zaid, Mohammad Khair Saleem; Haffar, Mohamed
2016-10-10
Purpose The purpose of this paper is to study the effect of the implementation of Lean bundles on hospital performance in private hospitals in Jordan and evaluate how much the size of organization can affect the relationship between Lean bundles implementation and hospital performance. Design/methodology/approach The research is considered as quantitative method (descriptive and hypothesis testing). Three statistical techniques were adopted to analyse the data. Structural equation modeling techniques and multi-group analysis were used to examine the research's hypothesis, and to perform the required statistical analysis of the data from the survey. Reliability analysis and confirmatory factor analysis were used to test the construct validity, reliability and measurement loadings that were performed. Findings Lean bundles have been identified as an effective approach that can dramatically improve the organizational performance of private hospitals in Jordan. Main Lean bundles - just in time, human resource management, and total quality management are applicable to large, small and medium hospitals without significant differences in advantages that depend on size. Originality/value According to the researchers' best knowledge, this is the first research that studies the impact of Lean bundles implementation in healthcare sector in Jordan. This research also makes a significant contribution for decision makers in healthcare to increase their awareness of Lean bundles.
Study of O’Neill’s Tragic View in the Light of his Life Experience
Institute of Scientific and Technical Information of China (English)
杨宝珍; 杨巳炜
2013-01-01
O’Neill’s tragedy deeply rooted in his own life experience and his family heredity. He is an offspring of Irish immi-grants, his homelessness as a child, his early education in the catholic school and his later break with religion, his foreign expedi-tion, life on the sea and his three marriages all influenced his life and his career and his theme decisively.
Design and fabrication of remote welding system for the fuel bundle assembly
Energy Technology Data Exchange (ETDEWEB)
Kim, S.S.; Lee, J.W.; Park, G.I. [Korea Atomic Energy Research Inst., Daejeon (Korea, Republic of)
2011-07-01
Remote fuel bundle welding equipment in a hot-cell was designed and fabricated. To achieve this, a preliminary investigation of hands-on fuel fabrication outside a hot-cell was conducted with a consideration of the constraints caused by welding in a hot-cell. Some basic experiments were also carried out to improve the end-plate welding process for fuel bundle fabrication. The resistance welding equipment using end-plate welding was also improved. It was found that resistance welding was more suitable for joining an end-plate to end caps in a hot-cell. The optimum conditions for end-plate welding for remote operation were also obtained. Preliminary performances to improve the resistance welding process were also examined, and the resistance welding process was determined to be the best in the hot-cell environment for fuel bundle fabrication. The greatest advantage of fuel bundle welding equipment would be a commercialized welding process in which there is extensive production experience. This paper presents an outline of the developed welding equipment for a fuel bundle fabrication and reviews the conceptual design of remote welding equipment using a master-slave manipulator. The design of the remote welding equipment using the Pro-Engineer method was also reviewed. Furthermore the mechanical considerations and a mock-up simulation test were described. Finally, its performance test results were presented for a mock-up of remote fuel bundle welding equipment. (author)
Holomorphic Vector Bundles Corresponding to some Soliton Solutions of the Ward Equation
International Nuclear Information System (INIS)
Holomorphic vector bundles corresponding to the static soliton solution of the Ward equation were explicitly presented by Ward in terms of a meromorphic framing. Bundles (for simplicity, “bundle” is to be taken throughout to mean “holomorphic vector bundle”) corresponding to all Ward k-soliton solutions whose extended solutions have only simple poles, and some Ward 2-soliton solutions whose extended solutions have only a second-order pole, were explicitly described by us in a previous paper. In this paper, we go on to present some bundles corresponding to soliton-antisoliton solutions of the Ward equation, and Ward 3-soliton solutions whose extended solutions have a simple pole and a double pole. To give some more interpretation of the bundles, we study the second Chern number of the corresponded bundles and find that it can be obtained directly from the patching matrices. We also point out some information about bundles corresponding to Ward soliton solutions whose extended solutions have general pole data at the end of the paper
Holomorphic Vector Bundles Corresponding to some Soliton Solutions of the Ward Equation
Energy Technology Data Exchange (ETDEWEB)
Zhu, Xiujuan, E-mail: yzzhuxiujuan@sina.com [Jiangsu Second Normal University, School of Mathematics and Information Technology (China)
2015-12-15
Holomorphic vector bundles corresponding to the static soliton solution of the Ward equation were explicitly presented by Ward in terms of a meromorphic framing. Bundles (for simplicity, “bundle” is to be taken throughout to mean “holomorphic vector bundle”) corresponding to all Ward k-soliton solutions whose extended solutions have only simple poles, and some Ward 2-soliton solutions whose extended solutions have only a second-order pole, were explicitly described by us in a previous paper. In this paper, we go on to present some bundles corresponding to soliton-antisoliton solutions of the Ward equation, and Ward 3-soliton solutions whose extended solutions have a simple pole and a double pole. To give some more interpretation of the bundles, we study the second Chern number of the corresponded bundles and find that it can be obtained directly from the patching matrices. We also point out some information about bundles corresponding to Ward soliton solutions whose extended solutions have general pole data at the end of the paper.
The Business of Bundling: Joining Forces on Joint Replacement.
Kaldy, Joanne
2016-03-01
A mandated bundled-payment program for joint replacement is in place in several regions across the country, and practitioners such as pharmacists are still sorting out their roles in this federal initiative. To get involved, pharmacists need to establish connections with area hospitals and physician groups to promote and document their ability to manage medications, reduce and eliminate medication-related problems and rehospitalizations, and work with patients to maximize adherence and improve communication for those undergoing hip and knee replacement.
Fabrication of a CANFLEX-RU designed bundle for power ramp irradiation test in NRU
International Nuclear Information System (INIS)
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% 235U in the outer and intermediate rings and also contains pellets enriched to 2.00 wt% 235U 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 UO2 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
Vadim Kuznetsov. Informal Biography by Eyes of His First Adviser
Directory of Open Access Journals (Sweden)
Igor V. Komarov
2007-06-01
Full Text Available The paper is dedicated to the memory of prominent theoretical physicist and mathematician Dr. Vadim Kuznetsov who worked, in particular, in the fields of the nonlinear dynamics, separation of variables, integrability theory, special functions. It includes his short research biography, an account of the start of his research career and the list of publications.
Directory of Open Access Journals (Sweden)
Еprintsev А.Т.
2006-12-01
Full Text Available Salt-induced changes in malatdehydrogenase system activity make the essential contribution to cell adaptation to stress condition. The enzyme systems of C4-plants are most interesting due to their ability for adaptation to environment conditions. The role of separate components of malatdehydrogenase complex of mesophyll and bundle sheath cells of corn in formation of adaptive reaction in stressful conditions is investigated in presented work.The activation of all enzymes of malatdehydrogenase system and the subsequent decrease in their activity was observed in mesophyll durring the first stage of adaptation to salt influence. In bundle sheath cells such parameters are differed from control less essentially. Fast accumulation of piruvate in cells and malate in both investigated tissues was induced. The further salinity led to falling of concentration this intermediate. The concentration of piruvate was below control level, and it was raised by the end of an exposition.The results show that sodium chloride causes induction of Krebs-cycle in mesophyll and bundle sheath cells of corn and intensification of Hatch-Slack cycle. The described differences in function malatdehydrogenase systems of mesophyll and bundle sheath cells of leaves of corn under salinity mainly consist of the activity of enzymes of a studied complex in bundle sheath cells is subject to the minimal changes in comparison with mesophyll. Role of this enzymesystem in mechanisms of adaptive reaction of various tissues of corn to salt stress is discussed.
Allaire, Kathryn M; Watson, Glen M
2013-06-01
Adjustable hair bundle mechanoreceptors located on anemone tentacles detect movements of nearby, swimming prey. The hair bundles are formed by numerous actin-based stereocilia that converge onto a single, central kinocilium. Interestingly, morphological and functional changes to the hair bundles are induced by activating chemoreceptors that bind prey-derived N-acetylated sugars and proline, respectively. Morphological changes to the hair bundles involve alterations to the actin cytoskeleton of stereocilia. A pharmacological activation of Rho induces hair bundles to elongate to lengths comparable to those normally induced by exposure to N-acetylneuraminic acid (NANA) and prevents shortening of hair bundles normally induced by proline. Rho inhibition prevents NANA-induced elongation, but does not prevent proline-induced shortening of hair bundles. Western blots feature a band similar in mass to that predicted for a Rho homolog in the genome of Nematostella. Immunocytochemistry localizes Rho in stereocilia of the hair bundle. Anemone hair bundles arise from multicellular complexes. Data from experiments using heptanol, a gap junction uncoupler, indicate that cell-cell communication is required in order for activated chemoreceptors to induce morphological changes to the hair bundles.
Leo Kanner's Mention of 1938 in His Report on Autism Refers to His First Patient
Olmsted, Dan; Blaxill, Mark
2016-01-01
Leo Kanner begins his landmark 1943 case series on autistic children by stating the condition was first brought to his attention in 1938. Recent letters to "JADD" have described this reference as "mysterious" and speculated it refers to papers published that year by Despert or Asperger. In fact, as Kanner goes on to state, 1938…
Guido of Arezzo and His Influence on Music Learning
Directory of Open Access Journals (Sweden)
Anna J. Reisenweaver
2012-05-01
Full Text Available Throughout the history of Western music, Guido of Arezzo stands out as one of the most influential theorists and pedagogues of the Middle Ages. His developments of the hexachord system, solmization syllables, and music notation revolutionized the teaching and learning of music during his time and laid the foundation for our modern system of music. While previous theorists were interested in the philosophical and mathematical nature of music, Guido’s desire to aid singers in the learning process was practical. Through his innovations, students were able to classify, sight-sing, and visualize the music they were learning, ultimately resulting in an easier, simpler, and more efficient way to learn music. By building upon the theories of those before him, Guido expanded and reshaped the musical system of his day, transformed the way music was taught, and established his ideas as a vital part of our musical heritage.
The Abilities of a Musical Savant and His Family.
Young, R. L.; Nettelbeck, T.
1995-01-01
Evaluation of a 12-year-old autistic musical savant revealed that the boy had idiosyncratic levels of cognitive functioning and perfect pitch recognition. His ability to recall and perform musical pieces after listening to a tape recording were found to be exceptional, but dependent upon his familiarity with musical structure and therefore…
International Nuclear Information System (INIS)
Full text: For reprocessing of PHWR fuel, fuel bundles are at present chopped mechanically into small pieces of pins using high tonnage mechanical press before dissolution. The existing method of bundle dismantling is purely mechanical using very high force for chopping. A laser based automated bundle dismantling system is developed. In the system, end-plates of bundle, which holds the fuel pins together, are cut using Nd-YAG laser to separate the bundles into pins. In addition to pin separation, the pins are to be chopped into small pieces using a small mechanical chopper. Since the spent fuel is highly radioactive, all these operations are performed remotely in hot cells. Post irradiation examination also requires dismantling of bundles into pins so that they can select the pins for the further examinations. In both these applications laser dismantling remains the most. important step and this system has been developed and tested. This paper describes the experience gained during the development efforts
Uniformization of the Moduli Space of Pairs Consisting of a Curve and a Vector Bundle
González, E Gómez; Porras, J M Muñoz; Martín, F J Plaza
2010-01-01
This paper is devoted to the study of the uniformization of the moduli space of pairs (X, E) consisting of an algebraic curve and a vector bundle on it. For this goal, we study the moduli space of 5-tuples (X, x, z, E, \\phi), consisting of a genus g curve, a point on it, a local coordinate, a rank n degree d vector bundle and a formal trivialization of the bundle at the point. A group acting on it is found and it is shown that it acts (infinitesimally) transitively on this moduli space and an identity between central extensions of its Lie algebra is proved. Furthermore, a geometric explanation for that identity is offered.
International Nuclear Information System (INIS)
Highlights: • Thermal–hydraulic performance of a non-circular tube bundle has been investigated experimentally. • Tubes were mounted in staggered arrangement with two longitudinal pitch ratios 1.5 and 2. • Drag coefficient and Nusselt number of tubes in second row was measured. • Friction factor of this tube bundle is lower than circular tube bundle. • Thermal–hydraulic performance of this tube bundle is greater than circular tube bundle. - Abstract: Flow and heat transfer from cam-shaped tube bank in staggered arrangement is studied experimentally. Tubes were located in test section of an open loop wind tunnel with two longitudinal pitch ratios 1.5 and 2. Reynolds number varies in range of 27,000 ⩽ ReD ⩽ 42,500 and tubes surface temperature is between 78 and 85 °C. Results show that both drag coefficient and Nusselt number depends on position of tube in tube bank and Reynolds number. Tubes in the first column have maximum value of drag coefficient, while its Nusselt number is minimum compared to other tubes in tube bank. Moreover, pressure drop from this tube bank is about 92–93% lower than circular tube bank and as a result thermal–hydraulic performance of this tube bank is about 6 times greater than circular tube bank
Theoretical calculations of thermophysical properties of single-wall carbon nanotube bundles
Institute of Scientific and Technical Information of China (English)
Miao Ting-Ting; Song Meng-Xuan; Ma Wei-Gang; Zhang Xing
2011-01-01
Carbon nanotube bundles are promising thermal interfacial materials due to their excellent thermal and mechanical characteristics. In this study, the phonon dispersion relations and density of states of the single-wall carbon nanotube bundles are calculated by using the force constant model. The calculation results show that the inter-tube interaction leads to a significant frequency raise of the low frequency modes. To verify the applied calculation method, the specific heat of a single single-wall carbon nanotube is calculated first based on the obtained phonon dispersion relations and the results coincide well with the experimental data. Moreover, the specific heat of the bundles is calculated and exhibits a slight reduction at low temperatures in comparison with that of the single tube. The thermal conductivity of the bundles at low temperatures is calculated by using the ballistic transport model. The calculation results indicate that the inter-tube interaction, i.e. van der Waals interaction, hinders heat transfer and cannot be neglected at extremely low temperatures. For (5, 5) bundles, the relative difference of the thermal conductivity caused by ignoring inter-tube effect reaches the maximum value of 26% around 17 K, which indicates the significant inter-tube interaction effect on the thermal conductivity at low temperatures.
Enhanced metalloadsorption of bacterial cells displaying poly-His peptides
Energy Technology Data Exchange (ETDEWEB)
Sousa, C.; Cebolla, A.; Lorenzo, V. de [CSIC, Madrid (Spain)
1996-08-01
The properties of Escherichia coli cells, acquired by cell surface presentation of one or two hexahistidine (His) clusters carried by the outer membrane LamB protein, have been examined. Strains producing LamB hybrids with the His chains accumulated greater than 11-fold more Cd{sup 2} than E. coli cells expressing the protein without the His insert. Furthermore, the hexa-His chains on the cell surface caused cells to adhere reversibly to a Ni{sup 2+}-containing solid matrix in a metal-dependent fashion. Thus, expression of poly-His peptides enables bacteria to act as a metalloaffinity adsorbent. These results open up the possibility for biosorption of heavy ions using engineered microorganisms. 32 refs., 3 figs.
Directory of Open Access Journals (Sweden)
V. B. Kuntysh
2014-01-01
Full Text Available The paper presents a scheme and description of a new aerodynamic stand that has a 300x300 mm cross-section operating channel. The stand is used for studying thermal and aerodynamic characteristics of bundles made of finned tubes of actual dimensions in crossflow. The paper provides results of an exploratory test pertaining to heat transfer and resistance of four row staggered bundle made of tubes with aluminium spiral fins having outside diameter of 26 mm which are used in the systems of ventilation, air-conditioning and heating of buildings and also in transport heat exchangers.
Study on galloping behavior of iced eight bundle conductor transmission lines
Zhou, Linshu; Yan, Bo; Zhang, Liang; Zhou, Song
2016-02-01
Wind tunnel test was carried out to obtain the aerodynamic coefficients of an eight bundle conductor accreted with crescent-shaped ice. A user-defined cable element with torsional degree of freedom is developed in ABAQUS software to capture the torsional deformation of the iced conductors during galloping. By means of the user-defined cable element, different damping ratios in in-plane, out-of-plane and torsional directions of the conductors can be defined and the aerodynamic forces varying with their motion status can be exerted on the conductors conveniently when ABAQUS is used to simulate galloping of transmission lines. A wind tunnel test to model galloping of an iced eight bundle conductor segment was carried out, and the validity of the numerical simulation method is demonstrated by the agreement of the galloping orbit of the bundle conductor segment model recorded in the test and that by the numerical simulation. Furthermore, galloping behavior, including dynamic responses, galloping orbits, frequencies, vibration modes and amplitudes, of typical iced eight bundle conductor transmission lines in the cases of different span lengths, initial tensions in sub-conductors, wind velocities, angles of wind attack and damping ratios is studied, and the galloping behavior of the lines with internal resonance conditions is discussed. The obtained results may provide a fundamental tool for the development of anti-galloping techniques of eight bundle conductor transmission lines.
Energy Technology Data Exchange (ETDEWEB)
Seo, Jeong Sik; Kim, Kyoung Rock; Choi, Young Don [Korea Univ., Seoul (Korea, Republic of); Shin, Jong Keun [Hanzhong Univ., Donghae (Korea, Republic of)
2008-07-01
This paper is described for the measurement technique for local heat transfer coefficients using a copper sensor in rod bundles with mixing vanes. A copper sensor is defined as the device to measure the convective heat transfer coefficient using constant heat flux and surface temperatures. The copper sensor consists of a cartridge heater and four pieces of thermocouple. The copper sensors located at axial positions of rod bundles are able to measure the local heat transfer coefficients at its positions. The effect of local heated and full heated of copper sensors for rod bundles is investigated using CFD analysis. The decay of local heat transfer coefficients of locally heating condition such as a copper sensor is estimated to be higher value than that of fully heating condition. The calibration curve for local heat transfer coefficients measured is presented.
An experimental study of water distribution from a jet to a single pin and pin bundles
International Nuclear Information System (INIS)
A knowledge of the water distribution in spray cooling of overheated water reactor fuel bundles is necessary for the proper analysis of heat removal under accident conditions. Results are presented of experiments on the distribution of water from a single horizontal jet to a cold vertical pin and both heated and unheated pin bundles. The flow running down a single cold pin has been determined for a range of jet impact angles, jet flow rates, and jet diameters. This is a critical flowrate above which water detaches from the pin at normal impact and it has been shown that at this critical flowrate the fraction of water flowing down the pin is proportional to the cosine of the impact angle. Tests with a cold six-pin sector of a three-ringed 36 pin bundle showed that distribution of water to the pins was non-uniform and sensitive to both jet orientation and velocity, as may be expected from the single pin results. Experiments on a hot six-pin showed that individual pins quenched at a rate predictable from cold six-pin flow distribution tests and a hot single pin 'calibration' test, once wetting was fully established at the water injection level. Observations made in a 36 pin heated bundle with six water jets confirmed the findings on the smaller bundles. It has also been shown that during delays in the establishment of wetting, the water distribution will be markedly different to that once wetting is established. (author)
[Niccolo Paganini: medical aspects of his life and work].
Miranda C, Marcelo; Navarrete T, Luz; Zúñiga N, Gonzalo
2008-07-01
Niccolo Paganini is the most virtuous violinist of the history of music. He even received the nick name of "the violinist of the evil" for his outstanding skills on stage performance. It has been suggested that he had syphilis and tuberculosis, the commonest diseases of that time, but this hypothesis remains speculative. There are suggestions that he was the victim of iatrogenic mercurial poisoning. Furthermore, his body build suggests the presence of Ehlers-Danlos syndrome which could give him special anatomical conditions allowing him to achieve an amazing level of vírtuousness in his art. We herein review the medical aspects of this brilliant musician's life.
Shape of a Ponytail and the Statistical Physics of Hair Fiber Bundles
Goldstein, Raymond E.; Warren, Patrick B.; Ball, Robin C.
2012-02-01
A general continuum theory for the distribution of hairs in a bundle is developed, treating individual fibers as elastic filaments with random intrinsic curvatures. Applying this formalism to the iconic problem of the ponytail, the combined effects of bending elasticity, gravity, and orientational disorder are recast as a differential equation for the envelope of the bundle, in which the compressibility enters through an “equation of state.” From this, we identify the balance of forces in various regions of the ponytail, extract a remarkably simple equation of state from laboratory measurements of human ponytails, and relate the pressure to the measured random curvatures of individual hairs.
Posttest examination of the VVER-1000 fuel rod bundle CORA-W2
International Nuclear Information System (INIS)
The bundle meltdown experiment CORA-W2, representing the behavior of a Russian type VVER-1000 fuel element, with one B4C/stainless steel absorber rod was selected by the OECD/CSNI as International Standard Problem (ISP-36). The experimental results of CORA-W2 serve as data base for comparison with analytical predictions of the high-temperature material behavior by various code systems. The first part of the experimental results is described in KfK 5363 (1994), the second part is documented in this report which contains the destructive post-test examination results. The metallographical and analytical (SEM/EDX) post-test examinations were performed in Germany and Russia and are summarized in five individual contributions. The upper half of the bundle is completely oxidized, the lower half has kept the fuel rods relatively intact. The post-test examination results show the strong impact of the B4C absorber rod and the stainless steel grid spacers on the ''low-temperature'' bundle damage initiation and progression. The B4C absorber rod completely disappeared in the upper half of the bundle. The multicomponent melts relocated and formed coolant channel blockages on solidification with a maximum extent of about 30% in the lower part of the bundle. At temperatures above the melting point of the ZrNb1 cladding extensive fuel dissolution occurred. (orig.)
International Nuclear Information System (INIS)
The CANFLEX1 bundle is being developed jointly by AECL and KAERI as a vehicle for introducing the use of enrichment and advanced fuel cycles in CANDU2 reactors. The bundle design uses smaller diameter fuel elements in the outer ring of a 43-element bundle to reduce the maximum element ratings in a CANDU fuel bundle by 20% compared to the 37-element bundle currently in use. This facilitates burnups of greater than 21,000 MW d/TAU to optimize the economic benefit available from the use of enrichment and advanced fuel cycles. A combination of this lower fuel rating, plus development work underway at Aecl to enhance the thermalhydraulic characteristics of the bundle (including both CHF3 and bundle. This provides extra flexibility in the fuel management procedures required for fuel bundles with higher fissile contents. The different bundle geometry requires flow tests to demonstrate acceptable vibration and fretting behavior of the Conflux bundle. A program to undertake the necessary range of flow tests has started at KAERI, involving the fabrication of the required bundles, and setting up for the actual tests. A program to study the fuel management requirements for slightly enriched (0.9 wt % 235 in total U) Conflux fuel has been undertaken by both Aecl and KAERI staff, and further work has started for higher enrichments. Irradiation testing of the Conflux bundle started in the NUR reactor in 1989, and a second irradiation test is due to start shortly. This paper describes the program, and reviews the status of key parts of the program
Energy Technology Data Exchange (ETDEWEB)
R Acharya; V Carnevale; G Fiorin; B Levine; A Polishchuk; V Balannick; I Samish; R Lamb; L Pinto; et al.
2011-12-31
The M2 proton channel from influenza A virus is an essential protein that mediates transport of protons across the viral envelope. This protein has a single transmembrane helix, which tetramerizes into the active channel. At the heart of the conduction mechanism is the exchange of protons between the His37 imidazole moieties of M2 and waters confined to the M2 bundle interior. Protons are conducted as the total charge of the four His37 side chains passes through 2{sup +} and 3{sup +} with a pK{sub a} near 6. A 1.65 {angstrom} resolution X-ray structure of the transmembrane protein (residues 25-46), crystallized at pH 6.5, reveals a pore that is lined by alternating layers of sidechains and well-ordered water clusters, which offer a pathway for proton conduction. The His37 residues form a box-like structure, bounded on either side by water clusters with well-ordered oxygen atoms at close distance. The conformation of the protein, which is intermediate between structures previously solved at higher and lower pH, suggests a mechanism by which conformational changes might facilitate asymmetric diffusion through the channel in the presence of a proton gradient. Moreover, protons diffusing through the channel need not be localized to a single His37 imidazole, but instead may be delocalized over the entire His-box and associated water clusters. Thus, the new crystal structure provides a possible unification of the discrete site versus continuum conduction models.
Boltanski's moral sociology and his implicit theory of ideology
Jacquemain, Marc
2008-01-01
The paper exposes the main lines of sociology of action regimes and of justification of Boltanski. It also shows how his concept of "test" is very well suited to a non deterministic sociology, a sociology of contingency
Criteria for the onset of mixed convection and onset of recirculation in vertical rod bundles
International Nuclear Information System (INIS)
Criteria were developed for the onset of recirculation and onset of mixed convection in vertical rod bundles. It was concluded that the dominant mechanisms governing mixed convection in rod bundles are the frictional and buoyancy forces. By balancing these two terms, the key dimensionless parameters were identified as Re and B*. The criteria was expressed in terms of a flow regime map of Re versus B*. It was found that the onset of mixed convection could be predicted with forced convection input parameters, but for the onset of recirculation the effect of buoyancy on mixing was important
Park, Sang Eun; Ko, Yujin
2013-01-01
Surgical reconstruction is a general approach for an anterior cruciate ligament rupture. Techniques have evolved from single-bundle to double-bundle reconstruction to restore the 2 anatomically and functionally different bundles as much as possible. However, there is controversy regarding which method yields superior clinical outcomes. The purpose of this article is to introduce our new graft preparation method, which will potentially address the limitations of currently available double-bund...
FINITE ELEMENT ANALYSIS OF LAMINAR FLOW AND HEAT TRANSFER IN A BUNDLE OF CYLINDERS
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
In this paper two-dimensional Navier-Stokes equations and energy equation governing incompressible laminar flow past a bundle of cylinders were numerically solved by using the finite element method.The velocity correction method was used for time advancement, and spatial discretization was carried out with the Galerkin weighted residual method.Viscous flows past the cylinder banks arranged in in-line cylinder bundles and staggered cylinder bundles, coupled with heat transfer, were investigated for pitch-diameter ratios of 1.5 and 2.0 and the Reynolds numbers from 50 to 500.Flow structures and heat transfer behavior were discussed.The results obtained agree well with available numerical data.
Safety analysis report of the irradiation test of Type-B bundle
Energy Technology Data Exchange (ETDEWEB)
Lee, Choong Sung; Lim, I. C.; Lee, B. C.; Ryu, J. S.; Kim, H. R
2000-06-01
The HANARO fuel, U{sub 3}Si-A1, has been developed by AECL and tested in NRU reactor. In the course of the fuel qualification tests, only one case was performed under the higher power condition than maximum linear power which was expected in the design stage. The Korea regulatory body, KINS imposed that HANARO shall be operated at the power level less than 24MW which is 80% of the design full power until HANARO shows the repetitive performance of the fuel at the power condition abov e 112.8KW/m. To resolve this imposition, KAERI designed two types of special test bundles: two non-instrumented(Type-A) and one instrumented(Type-B) test bundles. Two Type-A bundles were irradiated in HANARO: one of them has finished PIE and the other is under PIE. Type-B bundle was loaded in the core during 1.32 day at 1996, but outstanding FIV(flow induced vibration) was observed at the pool top because of long guide tube attached to the top of the bundle. The successful installation of the chimney fastener to fix the guide tube resulted in conducting the irradiation test of Type-B bundle again. The test will start at mid- July, 2000. In order to safely do the Type-B irradiation test, the safety analysis for the nuclear, mechanical and thermal-hydraulic aspects was performed. The reactivity worth and the maximum 1 near power predicted by VENTURE are 6.3mk/k and 121.6kW/m, respectively. Thermal margins for normal and transient conditions using MATRA-h, are assessed to satisfy the safety criteria.
Energy Technology Data Exchange (ETDEWEB)
Doebner, H.; Mann, H. [Arnold Sommerfeld Institute for Mathematical Physics, Technical University of Clausthal, 38678 Clausthal-Zellerfeld (Germany)
1997-08-01
We consider configuration spaces of nonidentical pointlike particles. The physically motivated assumption that any two particles cannot be located at the same point in space{endash}time leads to nontrivial topological structure of the configuration space. For a quantum mechanical description of such a system, we classify complex vector bundles over the configuration space and obtain potentials of topological origin, similar to those that occur in the fiber bundle approach to Dirac{close_quote}s magnetic monopole or in Yang{endash}Mills theory. {copyright} {ital 1997 American Institute of Physics.}
The Picard group of the moduli of G-bundles on a curve
Beauville, Arnaud; Laszlo, Yves; Sorger, Christoph
1996-01-01
Let G be a complex semi-simple group, and X a compact Riemann surface. The moduli space of principal G-bundles on X, and in particular the holomorphic line bundles on this space and their global sections, play an important role in the recent applications of Conformal Field Theory to algebraic geometry. In this paper we determine the Picard group of this moduli space when G is of classical or G_2 type (we consider both the coarse moduli space and the moduli stack).
Daniel Bovet and his role in the development of psychobiology.
Oliverio, Alberto
2008-01-01
One hundred years since his birth, fifty years after his Nobel achievement, Daniel Bovet still emerges as one of the key figures of both pharmacology and psychobiology, the biological and evolutionary roots of behaviour. The life and scientific activities of Daniel Bovet (1907-1992) are closely linked to the 'golden years' of pharmacology, the exceptional development of this science from the end of the 1930s to the 1960s. Later on, from the 1960s to the end of his scientific career, Bovet entered a new field, psychobiology, through the study of the effects of drugs active on the nervous system and their effects on behaviour. This approach led him to explore different aspects of the biology of behaviour, namely the role of individual differences, the genetic determinants of behaviour and their implications on learning and memory. It is therefore evident that the range of his scientific activity has been very broad, a fact difficultly conceivable in years of extreme specialization.
The many faces of Maxwell, Dirac and Einstein equations a Clifford bundle approach
Rodrigues, Jr, Waldyr A
2016-01-01
This book is an exposition of the algebra and calculus of differential forms, of the Clifford and Spin-Clifford bundle formalisms, and of vistas to a formulation of important concepts of differential geometry indispensable for an in-depth understanding of space-time physics. The formalism discloses the hidden geometrical nature of spinor fields. Maxwell, Dirac and Einstein fields are shown to have representatives by objects of the same mathematical nature, namely sections of an appropriate Clifford bundle. This approach reveals unity in diversity and suggests relationships that are hidden in the standard formalisms and opens new paths for research. This thoroughly revised second edition also adds three new chapters: on the Clifford bundle approach to the Riemannian or semi-Riemannian differential geometry of branes; on Komar currents in the context of the General Relativity theory; and an analysis of the similarities and main differences between Dirac, Majorana and ELKO spinor fields. The exercises with solut...
COPD exacerbation care bundle improves standard of care, length of stay, and readmission rates
Directory of Open Access Journals (Sweden)
Parikh R
2016-03-01
Full Text Available Raj Parikh,1 Trushil G Shah,2 Rajive Tandon2 1Department of Internal Medicine, 2Department of Pulmonary and Critical Care Medicine, Rush University Medical Center, Chicago, IL, USA Introduction: COPD is the third leading cause of death in the world. Utilizing care bundles during acute COPD exacerbations results in fewer complications and lower costs. Our aim was to construct a COPD exacerbation care bundle and evaluate the effects on patient care. Methods: We conducted a prospective analysis of 44 patients admitted with a COPD exacerbation to a single tertiary care facility. Primary outcomes included length of stay, readmission rates, and hospital costs. Secondary outcomes included patient education, pulmonologist follow-up, and timeliness of medication administration. Two cohorts were analyzed: those treated with an electronic COPD care bundle (cases; N=22 versus those treated without the care bundle (controls; N=22. Results: Mean length of stay (51.2 vs 101.1 hours in controls; P-value =0.001, 30-day readmission rates (9.1% vs 54.4% in controls; P-value =0.001, and 60-day readmission rates (22.7% vs 77% in controls; P-value =0.0003 decreased in the care bundle group. Ninety-day hospital costs had a significant difference in the care bundle group (US$7,652 vs US$19,954 in controls; P-value =0.044. Secondary outcomes included a 100% rate of COPD inhaler teaching (vs 27.3% in controls; P-value <0.001, 59.1% rate of pulmonologist follow-up after discharge (vs 18.2% in controls; P-value =0.005, and a mean reduction in time to steroid administration (7.0 hours; P-value =0.015 seen in the care bundle cases. Conclusion: Our significant findings coupled with the recent success of standardized algorithms in managing COPD exacerbations stress the importance of enforcing clinical guidelines that can enhance patient care. We demonstrated improved care for COPD exacerbation patients during hospitalizations, thereby decreasing morbidity and the financial
Directory of Open Access Journals (Sweden)
Jasper van der Slegt
Full Text Available BACKGROUND: Surgical site infections (SSI's are associated with severe morbidity, mortality and increased health care costs in vascular surgery. OBJECTIVE: To implement a bundle of care in vascular surgery and measure the effects on the overall and deep-SSI's rates. DESIGN: Prospective, quasi-experimental, cohort study. METHODS: A prospective surveillance for SSI's after vascular surgery was performed in the Amphia hospital in Breda, from 2009 through 2011. A bundle developed by the Dutch hospital patient safety program (DHPSP was introduced in 2009. The elements of the bundle were (1 perioperative normothermia, (2 hair removal before surgery, (3 the use of perioperative antibiotic prophylaxis and (4 discipline in the operating room. Bundle compliance was measured every 3 months in a random sample of surgical procedures and this was used for feedback. RESULTS: Bundle compliance improved significantly from an average of 10% in 2009 to 60% in 2011. In total, 720 vascular procedures were performed during the study period and 75 (10.4% SSI were observed. Deep SSI occurred in 25 (3.5% patients. Patients with SSI's (28,5±29.3 vs 10.8±11.3, p<0.001 and deep-SSI's (48.3±39.4 vs 11.4±11.8, p<0.001 had a significantly longer length of hospital stay after surgery than patients without an infection. A significantly higher mortality was observed in patients who developed a deep SSI (Adjusted OR: 2.96, 95% confidence interval 1.32-6.63. Multivariate analysis showed a significant and independent decrease of the SSI-rate over time that paralleled the introduction of the bundle. The SSI-rate was 51% lower in 2011 compared to 2009. CONCLUSION: The implementation of the bundle was associated with improved compliance over time and a 51% reduction of the SSI-rate in vascular procedures. The bundle did not require expensive or potentially harmful interventions and is therefore an important tool to improve patient safety and reduce SSI's in patients undergoing
Zhang, Liuyang; Wang, Xianqiao
2014-08-12
Single-walled carbon nanotubes (SWCNTs) have demonstrated a remarkable capacity for self-assembly into nanobundles through intermolecular van der Waals interactions, bestowing these agglomerates extraordinary mechanical, thermal, and electrical properties. However, how to improve the binding ability of SWCNT bundles to mitigate the delamination and sliding effects between individual nanotubes remains to be further investigated. By utilizing molecular dynamics simulation, here we present the construction of SWCNT bundles with discrete cylindrical and continuous helical binders by noncovalent coating of the bundle surface with sp(2)-hybridized carbon networks. Meanwhile, by modifying the binding potentials between the binder and SWCNT bundles to mimic the different binding types actually used, the bound SWCNT bundle presents a variety of distinct mechanical properties unmatched by unbound bundles. The pull-out tests with discrete binders portray an intriguing force-displacement curve which can help determine the number of discrete binders used in the system. SWCNT bundles with binders depict unique mechanical properties which can differentiate them from unbound SWCNT bundles. These findings provide compelling evidence that bound SWCNT bundles will open up novel avenues for a variety of applications, especially in nanocomposites.
Essential Closed Surfaces in a Class of Surface Sum of I-Bundle of Closed Surfaces
Institute of Scientific and Technical Information of China (English)
Shu Xin WANG; Rui Feng QIU
2011-01-01
In this paper,we will characterize all types of essential closed surfaces in a class of surface sum of I-bundle of closed surfaces,and give an application of the classification in the surface sum of two 3-manifolds.
CERN visit of His Excellency Mr.Kinga Singye / Bhutan
Hoch, Michael
2016-01-01
CERN visit of His Excellency Mr Kinga Singye Ambassador Extraordinary and Plenipotentiary Permanent Representative of the Kingdom of Bhutan to the United Nations Office and other international organisations in Geneva
Khurana, Ekta; Devane, Russell H; Dal Peraro, Matteo; Klein, Michael L
2011-02-01
The M2 protein of influenza A virus performs the crucial function of transporting protons to the interior of virions enclosed in the endosome. Adamantane drugs, amantadine (AMN) and rimantidine (RMN), block the proton conduction in some strains, and have been used for the treatment and prophylaxis of influenza A infections. The structures of the transmembrane (TM) region of M2 that have been solved in micelles using NMR (residues 23-60) (Schnell and Chou, 2008) and by X-ray crystallography (residues 22-46) (Stouffer et al., 2008) suggest different drug binding sites: external and internal for RMN and AMN, respectively. We have used molecular dynamics (MD) simulations to investigate the nature of the binding site and binding mode of adamantane drugs on the membrane-bound tetrameric M2-TM peptide bundles using as initial conformations the low-pH AMN-bound crystal structure, a high-pH model derived from the drug-free crystal structure, and the high-pH NMR structure. The MD simulations indicate that under both low- and high-pH conditions, AMN is stable inside the tetrameric bundle, spanning the region between residues Val27 to Gly34. At low pH the polar group of AMN is oriented toward the His37 gate, while under high-pH conditions its orientation exhibits large fluctuations. The present MD simulations also suggest that AMN and RMN molecules do not show strong affinity to the external binding sites.
Measurements of local temperature distributions in rod bundles with sodium flow
International Nuclear Information System (INIS)
In an electrically heated 19-rod bundle (P/D = 1.30, W/R = 1.40) with sodium flow the three-dimensional temperature fields in the rod clads were measured. The main characteristics of the test section are three adjacent heater rods in the duct wall zone instrumented on four measuring planes and rotatable by 3600 under full power conditions; furthermore spacer grids which are axially movable, and a system allowing to bow one heater rod over the last third of its heated length. The results of measurements of the azimuthal temperature variations of the rotatable rods are presented for different operating conditions (80 2), different spacer grid positions relative to the measuring planes and different bowing positions of one rod. For better understanding of the experimental results cross sections of the 19-rod bundle were prepared. It became evident, that a well-known bundle geometry is very important for the interpretation of the experimental results. (orig.)
Mohan, Vandana; Sundaramoorthi, Ganesh; Kubicki, Marek; Terry, Douglas; Tannenbaum, Allen
2010-03-01
We propose a novel framework for population analysis of DW-MRI data using the Tubular Surface Model. We focus on the Cingulum Bundle (CB) - a major tract for the Limbic System and the main connection of the Cingulate Gyrus, which has been associated with several aspects of Schizophrenia symptomatology. The Tubular Surface Model represents a tubular surface as a center-line with an associated radius function. It provides a natural way to sample statistics along the length of the fiber bundle and reduces the registration of fiber bundle surfaces to that of 4D curves. We apply our framework to a population of 20 subjects (10 normal, 10 schizophrenic) and obtain excellent results with neural network based classification (90% sensitivity, 95% specificity) as well as unsupervised clustering (k-means). Further, we apply statistical analysis to the feature data and characterize the discrimination ability of local regions of the CB, as a step towards localizing CB regions most relevant to Schizophrenia.
Peter Delpeut and His "Cinema of Loss"
Gilaitis, Aleksas, 1987-
2013-01-01
The era of television pushed film towards a slow death that has become more apparent in today's visual culture. Private collections of cinema rarely uphold any footage in the same form as it was invented more than one-hundred years ago. The problem of changing archival formats has led many films to complete disappearance since archival politics cannot protect every single image created by every single visual artist in the world. Early cinema has went through another “death“ of cinema with cru...
Strategies for the Evaluation of HIS Vendors
Rothenberg, Joan R.; Goodman, John D.
1984-01-01
The keys to successful hospital information system acquisition are discussed. Topics addressed include setting hospital objectives, documenting system requirements, identifying suitable vendors, preparing requests for information and proposals, and evaluating systems and vendors. The benefits of proper planning are stressed.
Analysis of steady state combined forced and free convection data in rod bundles
International Nuclear Information System (INIS)
Fuel and blanket assemblies in an LMFBR are subjected to a wide range of power and power gradients during their life in the reactor. To accommodate these changes the assemblies operate in a wide range of flow regimes extending from forced convection, turbulent flow, to mixed convection, laminar flow. At low flow conditions the transverse temperature gradient in an assembly is considerably flattened because of energy redistribution by not only wire-wrap mixing and thermal conduction but also by flow redistribution because of buoyancy-induced crossflow. This has significance in LMFBR design. For the mixed convection regime of bundle operation, the transverse velocity profiles within a bundle change axially because of buoyancy-induced crossflow. It was therefore decided to use the ENERGY II and ENERGY III computer programs for the analysis of the rod bundle mixed convection data
An Insight into His Philosophy of Life on the Basis of la Fontaine Fables
Institute of Scientific and Technical Information of China (English)
郭伟华
2007-01-01
In this thesis, the author introduces his life and the social background at those days, from which come Jane de la Fontaine' s masterpiece---Fablesand his philosophy of life and his influences on both his time and modern time.
A class of Poisson-Nijenhuis structures on a tangent bundle
Energy Technology Data Exchange (ETDEWEB)
Sarlet, W; Vermeire, F [Department of Mathematical Physics and Astronomy, Ghent University, Krijgslaan 281, B-9000 Ghent (Belgium); Research Assistant of the Fund for Scientific Research-Flanders, Belgium (FWO-Vlaanderen) (Belgium)
2004-06-18
Equipping the tangent bundle TQ of a manifold with a symplectic form coming from a regular Lagrangian L, we explore how to obtain a Poisson-Nijenhuis structure from a given type (1, 1) tensor field J on Q. It is argued that the complete lift J{sup c} of J is not the natural candidate for a Nijenhuis tensor on TQ, but plays a crucial role in the construction of a different tensor R, which appears to be the pullback under the Legendre transform of the lift of J to T*Q. We show how this tangent bundle view brings new insights and is capable also of producing all important results which are known from previous studies on the cotangent bundle, in the case when Q is equipped with a Riemannian metric. The present approach further paves the way for future generalizations.
Pliny the Elder and his History of Ancient Art
Directory of Open Access Journals (Sweden)
Graziella Melina
2007-12-01
Although Pliny the Elder based his history of ancient art on all the authors mentioned above, the writings of classical philologists and archeologists often imply that he might not have always used the art history literature mentioned as primary sources, but rather cited a great deal of information from the works of his predecessor, the famous Roman encyclopedist Marcus Terentius Varro (beginning of the 1st century BC.
CFD analysis of turbulent cross-flow in a staggered tube bundle equipped with grooved cylinders
Directory of Open Access Journals (Sweden)
Imine O.
2013-04-01
Full Text Available This study describes the Computational Fluid Dynamics (CFD analysis of the turbulent cross-flow in a staggered tube bundle with transverse and longitudinal pitch-to-diameter ratio of 3.8 and 2.1 respectively. Two Longitudinal grooves are placed on the external surface at 90° and 270° degrees. Each cylinder has two grooves on the external surface of the cylinder. The Navier-Stokes equations of the turbulent flow are solved using Spalart almaras, k-ε realizable and k-ω SST, turbulence models provided by Fluent CFD code. The staggered tube bundle geometry simulations were performed at steady conditions. An adapted grid using static pressure, pressure coefficient and velocity gradient, furthermore, a second order upwind scheme were used. The CFD results were in agreement with the experimental data. The study demonstrates the capability of the CFD calculations in predicting flow characteristics around the bundle
Direct numerical simulation of transitional flow in a staggered tube bundle
Linton, D.; Thornber, B.
2016-02-01
A series of Direct Numerical Simulations (DNS) of the flow through a staggered tube bundle has been performed over the range 1030 ≤ Rem ≤ 5572 to capture the flow transition that occurs at the matrix transition point of Rem ≈ 3000. The matrix transition is the point at which a second frequency becomes prominent in tube bundles. To date, this is the highest published Reynolds number at which a DNS has been performed on cross-flow over a tube bundle. This study describes the flow behaviour in terms of: the mean flow field, Strouhal numbers, vortex shedding, 3-D flow features, and turbulence properties. These results support the hypothesis that the transition in the vortex shedding behaviour at Rem ≈ 3000 is similar to that which occurs in single cylinder flow at the equivalent Reynolds number. The visualisations presented also demonstrate the nature of the shedding mechanisms before and after the matrix transition point.
The effects of the relative humidity (RH) of testing conditions on stelometer cotton flat bundle strength and elongation measurements, and on the morphology of fiber fractures are presented herein. A trend is observed for stelometer strength and elongations measurements; testing in conditions with h...
Stability of rank-3 Lazarsfeld-Mukai bundles on K3 surfaces
Lelli-Chiesa, Margherita
2011-01-01
Given an ample line bundle L on a K3 surface S, we study the slope stability with respect to L of rank-3 Lazarsfeld-Mukai bundles associated with complete, base point free nets of type g^2_d on curves C in the linear system |L|. When d is large enough and C is general, we obtain a dimensional statement for the variety W^2_d(C). If the Brill-Noether number is negative, we prove that any g^2_d on any smooth, irreducible curve in |L| is contained in a g^r_e which is induced from a line bundle on S, thus answering a conjecture of Donagi and Morrison. Applications towards transversality of Brill-Noether loci and higher rank Brill-Noether theory are then discussed.
Electrostatically actuated oscillator of bundle and double-walled carbon nanotubes
Energy Technology Data Exchange (ETDEWEB)
Kang, Jeong Won; Song, Ki Oh; Hwang, Ho Jung [Chung-Ang University, Seoul (Korea, Republic of); Lee, Jun Ha; Lee, Hoong Joo [Sangmyung University, Chonan (Korea, Republic of); Kwon, Oh Keun [Semyung University, Jecheon (Korea, Republic of); Yoon, Young Sik; Song, Young Jin [Konyang University, Nonsan (Korea, Republic of)
2006-03-15
Schematics of capacitively driven carbon nanotube (CNT) oscillators were presented and investigated by using classical molecular dynamics simulations. While the capacitive force acting on a CNT oscillator extruded it, the force exerted by the excess van der Waals energy sucked the CNT oscillator into the bundle or outer shell. The CNT oscillator could be oscillated by using both the Coulomb and the van der Waals interactions. The van der Waals force of the bundle-type CNT oscillator was less than the van der Waals force of the double-walled CNT oscillator. Molecular dynamics simulation results showed that double-walled CNT oscillators were better than bundle-type CNT oscillators in the aspects of both energy dissipation and stable operation.
The Effects of Resource Bundling on Third-party Logistics Providers’ Performance
Directory of Open Access Journals (Sweden)
Noorliza Karia
2015-03-01
resource bundling (excluding advanced technology is required to achieve cost leadership. The effects of other resources on performance are mediated mainly by the demand management interface capability and knowledge resources. This is a novel attempt to justify the interaction and mediation effects of resources and capabilities on performance. The research highlights the needs for 3PL managers to focus on developing and bundling their demand management interface capability and knowledge resources in order to achieve cost leadership, and further combine advanced technology into such bundling of resources and capabilities to achieve innovation in customer service. It advances the application of resource-based view (RBV theory in logistics research by identifying resources that play supporting roles and examining the capabilities for enhancing 3PLs’ competitive performance.
CFD simulation of vertical seven-rod bundle cooled with supercritical Freon-12
Energy Technology Data Exchange (ETDEWEB)
Huang, X.; Podila, K.; Rao, Y.F., E-mail: podilak@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)
2014-06-15
In this paper, a seven-rod bare bundle was simulated using ANSYS Fluent 6.3.26 to accurately predict the fluid flow and heat transfer behaviour under supercritical flow conditions. Seven turbulence models were compared to identify the appropriate model to predict the experiments performed at the Institute of Physics and Power Engineering on a vertically oriented seven-rod bare bundle cooled with supercritical Freon-12. It was found that predictions of wall temperatures and heat transfer coefficients are sensitive to the choice of turbulence model as well as to the near-wall treatment. Overall, the CFD simulations were able to predict the measured sheath temperature profiles along the length of the bundle within reasonable accuracy. (author)
Gabriel Garcia Marquez; The Significant Message of His Literary Discourse
Directory of Open Access Journals (Sweden)
Mohammad B. Aghaei
2015-03-01
Full Text Available Gabriel Garcia Marquez’s literary discourse actually portrays the destructive domination of colonial and imperialistic powers and civil wars that led to a series of insecurities and poverty in the community. In fact, whatever he has presented in his works is related to the realities of the continent that have been portrayed in his fictional world. In his works, every single line is a reference to a certain critical point in the history of Latin American continent and provides a magnifying glass for the reader to clearly conceptualize them. His works also represent the contemporary events that are frequently happening in the society. Keywords: Latin America, figurative techniques, legacy of colonialism, violence, Liberal and Conservative parties
CALCULATION OF AERIAL CABLE SPACER COMPRESSION FORCES IN BUNDLED PHASES DURING SHORT CIRCUIT FAULT
Directory of Open Access Journals (Sweden)
I. I. Sergey
2014-01-01
Full Text Available The paper presents an approximate method for calculation of electrodynamic resistance parameters of a flexible bus-bar with bundled phases. Comparison of the approximate calculation results with the computer calculations using a FAZA software tool has been given in the paper. An evaluation of permissible aerial cable spacer compression forces for designed modern standard distribution substations of 330 and 550 kV has been provided in the paper. The paper proposes an algorithm for determination of dynamics parameters in a bundled phase with due account of influence pertaining to viscoelastic characteristics of damping spacers.
Adsorption site analysis of impurity embedded single-walled carbon nanotube bundles
Agnihotri, S.; Mota, J.P.B.; Rostam-Abadi, M.; Rood, M.J.
2006-01-01
Bundle morphology and adsorptive contributions from nanotubes and impurities are studied both experimentally and by simulation using a computer-aided methodology, which employs a small physisorbed probe molecule to explore the porosity of nanotube samples. Grand canonical Monte Carlo simulation of nitrogen adsorption on localized sites of a bundle is carried out to predict adsorption in its accessible internal pore volume and on its external surface as a function of tube diameter. External adsorption is split into the contributions from the clean surface of the outermost nanotubes of the bundle and from the surface of the impurities. The site-specific isotherms are then combined into a global isotherm for a given sample using knowledge of its tube-diameter distribution obtained by Raman spectroscopy. The structural parameters of the sample, such as the fraction of open-ended nanotubes and the contributions from impurities and nanotube bundles to total external surface area, are determined by fitting the experimental nitrogen adsorption data to the simulated isotherm. The degree of closure between experimental and calculated adsorption isotherms for samples manufactured by two different methods, to provide different nanotube morphology and contamination level, further strengthens the validity and resulting interpretations based on the proposed approach. The average number of nanotubes per bundle and average bundle size, within a sample, are also quantified. The proposed method allows for extrapolation of adsorption properties to conditions where the purification process is 100% effective at removing all impurities and opening access to all intrabundle adsorption sites. ?? 2006 Elsevier Ltd. All rights reserved.
Li, Simon; Rehder, Kyle J; Giuliano, John S; Apkon, Michael; Kamat, Pradip; Nadkarni, Vinay M; Napolitano, Natalie; Thompson, Ann E; Tucker, Craig; Nishisaki, Akira
2016-01-01
Advanced airway management in the pediatric intensive care unit (PICU) is hazardous, with associated adverse outcomes. This report describes a methodology to develop a bundle to improve quality and safety of tracheal intubations. A prospective observational cohort study was performed with expert consensus opinion of 1715 children undergoing tracheal intubation at 15 PICUs. Baseline process and outcomes data in tracheal intubation were collected using the National Emergency Airway Registry for Children reporting system. Univariate analysis was performed to identify risk factors associated with adverse tracheal intubation-associated events. A multidisciplinary quality improvement committee was formed. Workflow analysis of tracheal intubation and pilot testing were performed to develop the Airway Bundle Checklist with 4 parts: (1) risk factor assessment, (2) plan generation, (3) preprocedure time-out to ensure that providers, equipment, and plans are prepared, (4) postprocedure huddle to identify improvement opportunities. The Airway Bundle Checklist developed may lead to improvement in airway management. PMID:25143411
Effective action of heterotic compactification on K3 with non-trivial gauge bundles
Energy Technology Data Exchange (ETDEWEB)
Schasny, Martin
2012-10-15
In this thesis we study the heterotic string compactified on K3 with non-trivial gauge bundles. We focus on two backgrounds, the well-known standard embedding and abelian line bundles. Using a Kaluza-Klein reduction, the six-dimensional effective action is computed up to terms of order {alpha}'{sup 2} with special attention on the hypermultiplet sector. We compute the moduli dependent couplings of the matter fields and analyze the geometry of the hyperscalar sigma model. Moreover, we prove the consistency with six-dimensional supergravity and derive the appropriate D-term scalar potential. For the line bundle backgrounds we show that the gauge flux stabilizes some geometrical moduli and renders some abelian vector multiplets massive.
Effective action of heterotic compactification on K3 with non-trivial gauge bundles
International Nuclear Information System (INIS)
In this thesis we study the heterotic string compactified on K3 with non-trivial gauge bundles. We focus on two backgrounds, the well-known standard embedding and abelian line bundles. Using a Kaluza-Klein reduction, the six-dimensional effective action is computed up to terms of order α'2 with special attention on the hypermultiplet sector. We compute the moduli dependent couplings of the matter fields and analyze the geometry of the hyperscalar sigma model. Moreover, we prove the consistency with six-dimensional supergravity and derive the appropriate D-term scalar potential. For the line bundle backgrounds we show that the gauge flux stabilizes some geometrical moduli and renders some abelian vector multiplets massive.
Study of matrix crack-tilted fiber bundle interaction using caustics and finite element method
Hao, Wenfeng; Zhu, Jianguo; Zhu, Qi; Yuan, Yanan
2016-02-01
In this work, the interaction between the matrix crack and a tilted fiber bundle was investigated via caustics and the finite element method (FEM). First, the caustic patterns at the crack tip with different distances from the tilted fiber were obtained and the stress intensity factors were extracted from the geometry of the caustic patterns. Subsequently, the shielding effect of the fiber bundle in front of the crack tip was analyzed. Furthermore, the interaction between the matrix crack and the broken fiber bundle was discussed. Finally, a finite element simulation was carried out using ABAQUS to verify the experimental results. The results demonstrate that the stress intensity factors extracted from caustic experiments are in excellent agreement with the data calculated by FEM.
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.
Indian Academy of Sciences (India)
Aydin Gezer
2009-06-01
The purpose of the present article is to investigate some relations between the Lie algebra of the infinitesimal fibre-preserving conformal transformations of the tangent bundle of a Riemannian manifold with respect to the synectic lift of the metric tensor and the Lie algebra of infinitesimal projective transformations of the Riemannian manifold itself.
5DFRXXL region of long myosin light chain kinase causes F-actin bundle formation
Institute of Scientific and Technical Information of China (English)
YANG Chunxiang; WEI Dongmei; CHEN Chen; YU Weiping; ZHU Minsheng
2005-01-01
Long myosin light chain kinase (L-MLCK) contains five DFRXXL motifs with ability to bind F-actin. Binding stoichiometry data indicated that each DFRXXL motif might bind each G-actin, but its biological significance remained unknown. We hypothesized that L-MLCK might act as an F-actin bundle peptides by its multiple binding sites of 5DFRXXL motifs to actin. In order to characterize F-actin-bundle formation properties of 5DFRXXL region of long myosin light chain kinase, we expressed and purified 5DFRXXL peptides tagged with HA in vitro. The properties of 5DFRXXL peptides binding to myofilaments or F-actin were analyzed by binding stoichiometries assays. The results indicated that 5DFRXXL peptides bound to myofilaments or F-actin with high affinity. KD values of 5DFRXXL binding to myofilaments and F-actin were 0.45 and 0.41 μmol/L, re- spectively. Cross-linking assay demonstrated that 5DFRXXL peptides could bundle F-actin efficiently. Typical F-actin bundles were observed morphologically through determina- tion of confocal and electron microscopy after adding 5DFRXXL peptides. After transfection of pEGFP-5DFRXXL plasmid into eukaryocyte, spike structure was observed around cell membrane edge. We guess that such structure formation may be attributable to F-actin over-bundle forma- tion caused by 5DFRXXL peptides. Therefore, we suppose that L-MLCK may be a new bundling protein and somehow play a certain role in organization of cell skeleton besides mediating cell contraction by it kinase activity.
Xie, Linfu; Hu, Han; Wang, Jingxue; Zhu, Qing; Chen, Min
2016-07-01
Combined bundle adjustment is a fundamental step in the processing of massive oblique images. Traditional bundle adjustment designed for nadir images gives identical weights to different parts of image point observations made from different directions, due to the assumption that the errors in the observations follow the same Gaussian distribution. However, because of their large tilt angles, aerial oblique images have trapezoidal footprints on the ground, and their areas correspond to conspicuously different ground sample distances. The errors in different observations no longer conform to the above assumption, which leads to suboptimal bundle adjustment accuracy and restricts subsequent 3D applications. To model the distribution of the errors correctly for the combined bundle adjustment of oblique images, this paper proposes an asymmetric re-weighting method. The scale of each pixel is used to determine a re-weighting factor, and each pixel is subsequently projected onto the ground to identify another anisotropic re-weighting factor using the shape of its quadrangle. Next, these two factors are integrated into the combined bundle adjustment using asymmetric weights for the image point observations; greater weights are assigned to observations with fine resolutions, and those with coarse resolutions are penalized. This paper analyzes urban and rural images captured by three different five-angle camera systems, from both proprietary datasets and the ISPRS/EuroSDR benchmark. The results reveal that the proposed method outperforms the traditional method in both back-projected and triangulated precision by approximately 5-10% in most cases. Furthermore, the misalignments of point clouds generated by the different cameras are significantly alleviated after combined bundle adjustment.
International Nuclear Information System (INIS)
The real-space dynamics and the nonlinear interactions among Fourier modes in elastic wave turbulence are investigated by simulating the Foppl-von Karman equation. We find that the bundle structures of ridges appear intermittently in the time evolution of the stretching energy field. The time-evolution of the nonlinearity indicates the existence of active and moderate phases in turbulent state. Conditional sampling analysis reveals that the bundle structure, which is the embodiment of the strong nonlinear interactions among modes, induces the energy supply from an external force to the system
Cadherin-23 May Be Dynamic in Hair Bundles of the Model Sea Anemone Nematostella vectensis
Pei-Ciao Tang; 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 anti...
Evaluation of CHF experimental data for non-square lattice 7-rod bundles
Energy Technology Data Exchange (ETDEWEB)
Hwang, Dae Hyun; Yoo, Y. J.; Kim, K. K.; Zee, S. Q
2001-01-01
A series of CHF experiments are conducted for 7-rod hexagonal test bundles in order to investigate the CHF characteristics of self-sustained square finned (SSF) rod bundles. The experiments are performed in the freon-loop and water-loop located at IPPE in Russia, and 609 data of freon-12 and 229 data of water are obtained from 7 kinds of test bundles classified by the combination of heated length and axial/radial power distributions. As the result of the evaluation of four representative CHF correlations, the EPRI-1 correlation reveals good prediction capability for SSF test bundles. The inlet parameter CHF correlation suggested by IPPE calculates the mean and the standard deviation of P/M for uniformly heated test bundles as 1.002 and 0.049, respectively. In spite of its excellent accuracy, the correlation has a discontinuity point at the boundary between the low velocity and high velocity conditions. KAERI's inlet parameter correlation eliminates this defect by introducing the complete evaporation model at low velocity condition, and calculates the mean and standard deviation of P/M as 0.095 and 0.062 for uniformly heated 496 data points, respectively. The mean/standard deviation of local parameter CHF correlations suggested by IPPE and KAERI are evaluated as 1.023/0.178 and 1.002/0.158, respectively. The inlet parameter correlation developed from uniformly heated test bundles tends to under-predict CHF about 3% for axially non-uniformly heated test bundles. On the other hand, the local parameter correlation reveals large scattering of P/M, and requires re-optimization of the correlation for non-uniform axial power distributions. As the result of the analysis of experimental data, it reveals that the correction model of axial power shapes suggested by IPPE is applicable to the inlet parameter correlations. For the test bundle of radial non-uniform power distribution, the physically unexpected results are obtained at some experimental conditions. In addition
Upper bounds for the essential dimension of the moduli stack of ${\\sl_{n}}$-bundles over a curve
Dhillon, Ajneet; Lemire, Nicole
2009-01-01
We find upper bounds for the essential dimension of various moduli stacks of $\\sln$-bundles over a curve. When $n$ is a prime power, our calculation computes the essential dimension of the stack of stable bundles exactly and the essential dimension is not equal to the dimension in this case.
Fast iteration of cocyles over rotations and Computation of hyperbolic bundles
Huguet, Gemma; Sire, Yannick
2011-01-01
In this paper, we develop numerical algorithms that use small requirements of storage and operations for the computation of hyperbolic cocycles over a rotation. We present fast algorithms for the iteration of the quasi-periodic cocycles and the computation of the invariant bundles, which is a preliminary step for the computation of invariant whiskered tori.
The Motive of the Moduli Stack of -Bundles over the Universal Curve
Indian Academy of Sciences (India)
Donu Arapura; Ajneet Dhillon
2008-08-01
We define relative motives in the sense of André. After associating a complex in the derived category of motives to an algebraic stack we study this complex in the case of the moduli of -bundles varying over the moduli of curves.
A Mechanistic Approach for the Prediction of Critical Power in BWR Fuel Bundles
Chandraker, Dinesh Kumar; Vijayan, Pallipattu Krishnan; Sinha, Ratan Kumar; Aritomi, Masanori
The critical power corresponding to the Critical Heat Flux (CHF) or dryout condition is an important design parameter for the evaluation of safety margins in a nuclear fuel bundle. The empirical approaches for the prediction of CHF in a rod bundle are highly geometric specific and proprietary in nature. The critical power experiments are very expensive and technically challenging owing to the stringent simulation requirements for the rod bundle tests involving radial and axial power profiles. In view of this, the mechanistic approach has gained momentum in the thermal hydraulic community. The Liquid Film Dryout (LFD) in an annular flow is the mechanism of CHF under BWR conditions and the dryout modeling has been found to predict the CHF quite accurately for a tubular geometry. The successful extension of the mechanistic model of dryout to the rod bundle application is vital for the evaluation of critical power in the rod bundle. The present work proposes the uniform film flow approach around the rod by analyzing individual film of the subchannel bounded by rods with different heat fluxes resulting in different film flow rates around a rod and subsequently distributing the varying film flow rates of a rod to arrive at the uniform film flow rate as it has been found that the liquid film has a strong tendency to be uniform around the rod. The FIDOM-Rod code developed for the dryout prediction in BWR assemblies provides detailed solution of the multiple liquid films in a subchannel. The approach of uniform film flow rate around the rod simplifies the liquid film cross flow modeling and was found to provide dryout prediction with a good accuracy when compared with the experimental data of 16, 19 and 37 rod bundles under BWR conditions. The critical power has been predicted for a newly designed 54 rod bundle of the Advanced Heavy Water Reactor (AHWR). The selected constitutive models for the droplet entrainment and deposition rates validated for the dryout in tube were
Directory of Open Access Journals (Sweden)
Mohammed Farghally Amin
2016-06-01
Conclusion: Increased signal intensity within the anteromedial or posterolateral bundles of a double bundle ACL reconstruction is frequently associated with a partial tear. Impingement of the anteromedial graft is frequently associated with partial tear and increased signal intensity which is proved by arthroscopy/surgery. A low incidence of other complications is seen.
Directory of Open Access Journals (Sweden)
David Legland
Full Text Available The cellular structure of plant tissues is a key parameter for determining their properties. While the morphology of cells can easily be described, few studies focus on the spatial distribution of different types of tissues within an organ. As plants have various shapes and sizes, the integration of several individuals for statistical analysis of tissues distribution is a difficult problem. The aim of this study is to propose a method that quantifies the average spatial organisation of vascular bundles within maize stems, by integrating information from replicated images. In order to compare observations made on stems of different sizes and shapes, a spatial normalisation strategy was used. A model of average stem contour was computed from the digitisation of several stem slab images. Point patterns obtained from individual stem slices were projected onto the average stem to normalise them. Group-wise analysis of the spatial distribution of vascular bundles was applied on normalised data through the construction of average intensity maps. A quantitative description of average bundle organisation was obtained, via a 3D model of bundle distribution within a typical maize internode. The proposed method is generic and could easily be extended to other plant organs or organisms.
Asymptotics of certain families of Higgs bundles in the Hitchin component
DEFF Research Database (Denmark)
Collier, Brian; Li, Qiongling
2015-01-01
of the Hermitian metric solving the Higgs bundle equations. This analysis is used to estimate the asymptotics of the corresponding family of flat connections as we scale the differentials by a real parameter. We consider Higgs fields that have only one holomorphic differential $q_n$ of degree $n$ or $q_{n-1...
Student assessment of teaching effectiveness of "bundle of changes"-A paired, controlled trial
Directory of Open Access Journals (Sweden)
Seema Kalra
2011-01-01
Full Text Available Background : Inching toward optimum patient safety by training personnel is the prime aim of the ongoing medical education. Aims : To assess whether lectures targeted to improve quality care in ICU could improve ICU practitioners′ knowledge levels and to evaluate the effectiveness of teaching. Settings and Design : In this paired controlled trial, 50 ICU practitioners, i.e., anesthesia and medicine residents and nursing staff of our hospital attended a series of four lectures. Materials and Methods : Participants enrolled in the study attended lectures on "bundles of changes" in ICU, namely, introduction, ventilator bundle, central line bundle, and catheter-related blood stream infections and severe sepsis bundle. They were given a questionnaire of 15 multiple choice questions prior to and after the lectures. We evaluated their immediate knowledge acquisition and retention recall. Subsequently, they evaluated the effectiveness of the teaching programme by a questionnaire of 10 multiple choice questions. Statistical analysis used: Data for statistical analysis were tabulated and analyzed using SPSS-Pc 11.5 version software. Results : Fifty study participants completed all three questionnaires. There was an increase in the overall mean score in the post-lecture test (4.58 + 1.51 SD (P < 0.001. Overall mean score increased significantly from 8.30 + 1.34 SD in THE pre-lecture test - to 12.02 + 1.61 SD in the postlecture re-test (3.72 + 1.39 SD (P < 0.001. In the evaluation of teaching effectiveness 88% respondents agreed to most of the questions, signifying the effectiveness of the lectures. However, there were 10% who disagreed to the questions and only 2% strongly disagreed to all the questions. Conclusions : Teaching programmes such as the "bundle of changes" are effective in improving immediate knowledge acquisition and retention recall of the participants if designed keeping the target audience in mind.
Affordable Care Organizations and Bundled Pricing: A New Philosophy of Care.
Barinaga, Gonzalo; Chambers, Monique C; El-Othmani, Mouhanad M; Siegrist, Richard B; Saleh, Khaled J
2016-10-01
Under the Patient Protection and Affordable Care Act (ACA), the Centers for Medicare and Medicaid Services' Innovation was chartered to develop new models of health care delivery. The changes meant a drastic need to restructure the health care system. To minimize costs and optimize quality, new laws encourage continuity in health care delivery within an integrated system. Affordable care organizations provided a model of high-quality care while reducing costs. Bundled payments can have a substantial effect on the national expenditures. This article examines new developments in bundle payments, affordable care organizations, and gainsharing agreements as they pertain to arthroplasty. PMID:27637657
Directory of Open Access Journals (Sweden)
Deepak Joshi
2014-01-01
Full Text Available Background: Double bundle anterior cruciate ligament (DBACL reconstruction is said to reproduce the native anterior cruciate ligament (ACL anatomy better than single bundle anterior cruciate ligament, whether it leads to better functional results is debatable. Different fixation methods have been used for DBACL reconstruction, the most common being aperture fixation on tibial side and cortical suspensory fixation on the femoral side. We present the results of DBACL reconstruction technique, wherein on the femoral side anteromedial (AM bundle is fixed with a crosspin and aperture fixation was done for the posterolateral (PL bundle. Materials and Methods: Out of 157 isolated ACL injury patients who underwent ACL reconstruction, 100 were included in the prospective study. Arthroscopic DBACL reconstruction was done using ipsilateral hamstring autograft. AM bundle was fixed using Transfix (Arthrex, Naples, FL, USA on the femoral side and bio interference screw (Arthrex, Naples, FL, USA on the tibial side. PL bundle was fixed on femoral as well as on tibial side with a biointerference screw. Patients were evaluated using KT-1000 arthrometer, Lysholm score, International Knee Documentation Committee (IKDC Score and isokinetic muscle strength testing. Results: The KT-1000 results were evaluated using paired t test with the P value set at 0.001. At the end of 1 year, the anteroposterior side to side translation difference (KT-1000 manual maximum showed mean improvement from 5.1 mm ± 1.5 preoperatively to 1.6 mm ± 1.2 ( P < 0.001 postoperatively. The Lysholm score too showed statistically significant ( P < 0.001 improvement from 52.4 ± 15.2 (range: 32-76 preoperatively to a postoperative score of 89.1 Â± 3.2 (range 67-100. According to the IKDC score 90% patients had normal results (Category A and B. The AM femoral tunnel initial posterior blow out was seen in 4 patients and confluence in the intraarticular part of the femoral tunnels was seen in 6
Importance of electrode positioning in the diagnosis of right bundle branch block.
Directory of Open Access Journals (Sweden)
Andrés Ramírez C.
2014-08-01
Full Text Available INTRODUCTION: The correct positioning of precordial electrodes of an electrocardiogram (ECG was agreed upon and formalized in 1938 by the American Heart Association (AHA and the Cardiac Society of Great Britain (CSGB , establishing the gold standard for the correct ECG procedure. The correct positioning of the electrodes is extremely important, with incorrect placement being related to right bundle branch block overdiagnosis and the subsequent social, psychological and economical effects of implying a pathological condition in a normal person. OBJECTIVE: To quantify the diagnosis of right bundle branch block in high right parasternal accessory leads (diagnostic test compared to classic precordial leads (gold standard. MATERIAL AND METHOD: A number of 100 consecutive patients were evaluated with resting 12-lead-electrocardiogram and high right parasternal accessory leads, after proper consent from patients. RESULTS: A 7% of patients presented right bundle branch block in classical precordial leads, compared with 29% in high right parasternal accessory leads. QRS complexes were all less than 120 milliseconds. DISCUSSION: There are not national available references analyzing electrode placement in the study of electrocardiographic abnormalities. There was an overdiagnosis of right bundle branch block in high right parasternal accessory leads. The association and relevance in the diagnosis of serious diseases, such as myocardial infarction and Brugada syndrome, makes the necessity of a solid foundation on electrocardiogram technique, of uttermost importance.
MRI diagnosis of ACL bundle tears: value of oblique axial imaging
Energy Technology Data Exchange (ETDEWEB)
Ng, Alex W.H.; Griffith, James F.; Hung, Esther H.Y. [Chinese University of Hong Kong, Department of Imaging and Interventional Radiology, Prince of Wales Hospital, Shatin, NT, Hong Kong SAR (China); Law, Kan Yip; Yung, Patrick S.H. [Chinese University of Hong Kong, Department of Orthopedics and Traumatology, Prince of Wales Hospital, Shatin, NT, Hong Kong SAR (China)
2013-02-15
To investigate the diagnostic accuracy of oblique axial intermediate weighting MR imaging in detecting partial thickness anterior cruciate ligament (ACL) bundle tears. The study protocol was approved by the institutional ethics committee. Sixty-one subjects (43 male, 18 female; mean age 27.4 years; range 9 to 57 years) with clinically suspected ACL tear or meniscal tear between September 2009 and January 2011 were studied with MRI and arthroscopy. Detection of partial tear for the ACL as a whole and for each ACL bundle by protocol A (standard orthogonal sequences) and protocol B (standard orthogonal sequences plus oblique axial intermediate weighted imaging) was compared in a blinded fashion. Performance characteristics for protocol A and protocol B were compared using sensitivity, specificity, accuracy and ROC curves. A two-tailed p value of <0.05 indicated statistical significance. Fifteen (24.6%) normal, 15 (24.6%) partial and 31 complete tears were diagnosed by arthroscopy. Sensitivity, specificity and accuracy of protocol A for the diagnosis of partial tear of the ACL was 33%, 87% and 74%, while for protocol B the values were 87%, 87% and 87% respectively. The area under the curve (AUC) for the diagnosis of partial ACL tear and individual bundle tear was higher for protocol B, although this difference did not reach statistical significance (p > 0.05). The addition of oblique axial imaging to standard MR imaging improves diagnostic accuracy for detecting partial tears of the ACL as well as individual bundle tears of the ACL. (orig.)
Land lease contracts: properties and the value of bundles of property rights
Slangen, L.H.G.; Polman, N.B.P.
2008-01-01
Contracts are mechanisms for carrying out transactions. Leasing land is a voluntary transaction in which property rights - such as user and income rights - are transferred from landowners to tenants. The bundle of property rights transferred within a lease transaction varies with the type of contrac
On Rationality of Moduli Spaces of Vector Bundles on Real Hirzebruch Surfaces
Indian Academy of Sciences (India)
Indranil Biswas; Ronnie Sebastian
2013-05-01
Let be a real form of a Hirzebruch surface. Let $M_H(r,c_1,c_2)$ be the moduli space of vector bundles on . Under some numerical conditions on $r,c_1$ and $c_2$, we identify those $M_H(r,c_1,c_2)$ that are rational.
Lamaming, Junidah; Hashim, Rokiah; Leh, Cheu Peng; Sulaiman, Othman; Sugimoto, Tomoko; Nasir, Mohammed
2015-12-10
In this study cellulose nanocrystals were isolated through acid hydrolysis process from parenchyma and vascular bundle of oil palm trunk (Elaeis guineensis). The morphological properties of obtained cellulose nanocrystals were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The microscopy images showed smoother and cleaner surface of parenchyma cellulose nanocrystals when compared to vascular bundle cellulose nanocrystals. The TEM image shows a higher length and diameter for parenchyma cellulose nanocrystals compared to vascular bundle cellulose nanocrystals. The Fourier transform infrared (FTIR) spectra showed changes in functional groups after acid hydrolysis due to removal of lignin, hemicelluloses and other impurities in both type of cellulose nanocrystals. Crystallinity index of cellulose nanocrystals was observed higher for vascular bundle as compared to parenchyma. Thermogravimetric analysis (TGA) was performed to study the thermal stability of cellulose nanocrystals and it was observed higher for parenchyma cellulose nanocrystals compared to vascular bundle.
Lamaming, Junidah; Hashim, Rokiah; Leh, Cheu Peng; Sulaiman, Othman; Sugimoto, Tomoko; Nasir, Mohammed
2015-12-10
In this study cellulose nanocrystals were isolated through acid hydrolysis process from parenchyma and vascular bundle of oil palm trunk (Elaeis guineensis). The morphological properties of obtained cellulose nanocrystals were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The microscopy images showed smoother and cleaner surface of parenchyma cellulose nanocrystals when compared to vascular bundle cellulose nanocrystals. The TEM image shows a higher length and diameter for parenchyma cellulose nanocrystals compared to vascular bundle cellulose nanocrystals. The Fourier transform infrared (FTIR) spectra showed changes in functional groups after acid hydrolysis due to removal of lignin, hemicelluloses and other impurities in both type of cellulose nanocrystals. Crystallinity index of cellulose nanocrystals was observed higher for vascular bundle as compared to parenchyma. Thermogravimetric analysis (TGA) was performed to study the thermal stability of cellulose nanocrystals and it was observed higher for parenchyma cellulose nanocrystals compared to vascular bundle. PMID:26428155
Differential calculi on noncommutative bundles
Pflaum, Markus J.; Schauenburg, Peter
1996-01-01
We introduce a category of noncommutative bundles. To establish geometry in this category we construct suitable noncommutative differential calculi on these bundles and study their basic properties. Furthermore we define the notion of a connection with respect to a differential calculus and consider questions of existence and uniqueness. At the end these constructions are applied to basic examples of noncommutative bundles over a coquasitriangular Hopf algebra.
Estimation of Single-fibre Tensile Properties from the Bundle Tensile Curve of Polyester Fibres
Institute of Scientific and Technical Information of China (English)
于伟东
2004-01-01
Fibre bundle tensile curves can be used to characterise fibre processing properties and end-use performance directly and to predict single-fibre properties in theory. In this paper, the tensile behaviour of polyester fibre-bundles has been analysed in characteristic values and diagramming. The characteristic distributions which include the symmetry distribution on right part, SRBS′ (e), on left part, SLBS′(e) and the curve on base-line modification, MBS′ (e),based on the modulus distribution, BS′ (e), as well as the frequency density function of broken fibres, B′ (e), have been derived from the tail of bundle tensile curves. The theoretical and measured results show that the most important curves are MBS′ ( e ) and B′ ( e ) and can be used to estimate the breaking-extension distribution of single fibres. Especially for MBS′(e), the modulus distribution can accurately characterize single-fibre tensile properties and is no limitation as the calculation of B′(e) because the bundle specific stress Y(e) of no fibre breaking at extension e should be found at first.
Assessment of ASSERT-PV for prediction of post-dryout heat transfer in CANDU bundles
International Nuclear Information System (INIS)
Highlights: • Assessment of the new Canadian subchannel code ASSERT-PV 3.2 for PDO sheath temperature prediction. • CANDU 28-, 37- and 43-element bundle PDO experiments. • Prediction improvement of ASSERT-PV 3.2 over previous code versions. • Sensitivity study of the effect of PDO model options. - Abstract: Atomic Energy of Canada Limited (AECL) has developed the subchannel thermalhydraulics code ASSERT-PV for the Canadian nuclear industry. The recently released ASSERT-PV 3.2 provides enhanced models for improved predictions of subchannel flow distribution, critical heat flux (CHF), and post-dryout (PDO) heat transfer in horizontal CANDU fuel channels. This paper presents results of an assessment of the new code version against PDO tests performed during five full-size CANDU bundle experiments conducted between 1992 and 2009 by Stern Laboratories (SL), using 28-, 37- and 43-element bundles. A total of 10 PDO test series with varying pressure-tube creep and/or bearing-pad height were analyzed. The SL experiments encompassed the bundle geometries and range of flow conditions for the intended ASSERT-PV applications for existing CANDU reactors. Code predictions of maximum PDO fuel-sheath temperature were compared against measurements from the SL PDO tests to quantify the code's prediction accuracy. The prediction statistics using the recommended model set of ASSERT-PV 3.2 were compared to those from previous code versions. Furthermore, separate-effects sensitivity studies quantified the contribution of each PDO model change or enhancement to the improvement in PDO heat transfer prediction. Overall, the assessment demonstrated significant improvement in prediction of PDO sheath temperature in horizontal fuel channels containing CANDU bundles
Assessment of ASSERT-PV for prediction of critical heat flux in CANDU bundles
International Nuclear Information System (INIS)
Highlights: • Assessment of the new Canadian subchannel code ASSERT-PV 3.2 for CHF prediction. • CANDU 28-, 37- and 43-element bundle CHF experiments. • Prediction improvement of ASSERT-PV 3.2 over previous code versions. • Sensitivity study of the effect of CHF model options. - Abstract: Atomic Energy of Canada Limited (AECL) has developed the subchannel thermalhydraulics code ASSERT-PV for the Canadian nuclear industry. The recently released ASSERT-PV 3.2 provides enhanced models for improved predictions of flow distribution, critical heat flux (CHF), and post-dryout (PDO) heat transfer in horizontal CANDU fuel channels. This paper presents results of an assessment of the new code version against five full-scale CANDU bundle experiments conducted in 1990s and in 2009 by Stern Laboratories (SL), using 28-, 37- and 43-element (CANFLEX) bundles. A total of 15 CHF test series with varying pressure-tube creep and/or bearing-pad height were analyzed. The SL experiments encompassed the bundle geometries and range of flow conditions for the intended ASSERT-PV applications for CANDU reactors. Code predictions of channel dryout power and axial and radial CHF locations were compared against measurements from the SL CHF tests to quantify the code prediction accuracy. The prediction statistics using the recommended model set of ASSERT-PV 3.2 were compared to those from previous code versions. Furthermore, the sensitivity studies evaluated the contribution of each CHF model change or enhancement to the improvement in CHF prediction. Overall, the assessment demonstrated significant improvement in prediction of channel dryout power and axial and radial CHF locations in horizontal fuel channels containing CANDU bundles
Assessment of ASSERT-PV for prediction of critical heat flux in CANDU bundles
Energy Technology Data Exchange (ETDEWEB)
Rao, Y.F., E-mail: raoy@aecl.ca; Cheng, Z., E-mail: chengz@aecl.ca; Waddington, G.M., E-mail: waddingg@aecl.ca
2014-09-15
Highlights: • Assessment of the new Canadian subchannel code ASSERT-PV 3.2 for CHF prediction. • CANDU 28-, 37- and 43-element bundle CHF experiments. • Prediction improvement of ASSERT-PV 3.2 over previous code versions. • Sensitivity study of the effect of CHF model options. - Abstract: Atomic Energy of Canada Limited (AECL) has developed the subchannel thermalhydraulics code ASSERT-PV for the Canadian nuclear industry. The recently released ASSERT-PV 3.2 provides enhanced models for improved predictions of flow distribution, critical heat flux (CHF), and post-dryout (PDO) heat transfer in horizontal CANDU fuel channels. This paper presents results of an assessment of the new code version against five full-scale CANDU bundle experiments conducted in 1990s and in 2009 by Stern Laboratories (SL), using 28-, 37- and 43-element (CANFLEX) bundles. A total of 15 CHF test series with varying pressure-tube creep and/or bearing-pad height were analyzed. The SL experiments encompassed the bundle geometries and range of flow conditions for the intended ASSERT-PV applications for CANDU reactors. Code predictions of channel dryout power and axial and radial CHF locations were compared against measurements from the SL CHF tests to quantify the code prediction accuracy. The prediction statistics using the recommended model set of ASSERT-PV 3.2 were compared to those from previous code versions. Furthermore, the sensitivity studies evaluated the contribution of each CHF model change or enhancement to the improvement in CHF prediction. Overall, the assessment demonstrated significant improvement in prediction of channel dryout power and axial and radial CHF locations in horizontal fuel channels containing CANDU bundles.
Assessment of ASSERT-PV for prediction of post-dryout heat transfer in CANDU bundles
Energy Technology Data Exchange (ETDEWEB)
Cheng, Z., E-mail: chengz@aecl.ca; Rao, Y.F., E-mail: raoy@aecl.ca; Waddington, G.M., E-mail: waddingg@aecl.ca
2014-10-15
Highlights: • Assessment of the new Canadian subchannel code ASSERT-PV 3.2 for PDO sheath temperature prediction. • CANDU 28-, 37- and 43-element bundle PDO experiments. • Prediction improvement of ASSERT-PV 3.2 over previous code versions. • Sensitivity study of the effect of PDO model options. - Abstract: Atomic Energy of Canada Limited (AECL) has developed the subchannel thermalhydraulics code ASSERT-PV for the Canadian nuclear industry. The recently released ASSERT-PV 3.2 provides enhanced models for improved predictions of subchannel flow distribution, critical heat flux (CHF), and post-dryout (PDO) heat transfer in horizontal CANDU fuel channels. This paper presents results of an assessment of the new code version against PDO tests performed during five full-size CANDU bundle experiments conducted between 1992 and 2009 by Stern Laboratories (SL), using 28-, 37- and 43-element bundles. A total of 10 PDO test series with varying pressure-tube creep and/or bearing-pad height were analyzed. The SL experiments encompassed the bundle geometries and range of flow conditions for the intended ASSERT-PV applications for existing CANDU reactors. Code predictions of maximum PDO fuel-sheath temperature were compared against measurements from the SL PDO tests to quantify the code's prediction accuracy. The prediction statistics using the recommended model set of ASSERT-PV 3.2 were compared to those from previous code versions. Furthermore, separate-effects sensitivity studies quantified the contribution of each PDO model change or enhancement to the improvement in PDO heat transfer prediction. Overall, the assessment demonstrated significant improvement in prediction of PDO sheath temperature in horizontal fuel channels containing CANDU bundles.
Hierarchical composites: Analysis of damage evolution based on fiber bundle model
DEFF Research Database (Denmark)
Mishnaevsky, Leon
2011-01-01
A computational model of multiscale composites is developed on the basis of the fiber bundle model with the hierarchical load sharing rule, and employed to study the effect of the microstructures of hierarchical composites on their damage resistance. Two types of hierarchical materials were consi...
Diego Rivera and his extraordinary art of medicine and surgery.
Toledo-Pereyra, Luis H
2007-01-01
Diego Rivera (1886-1957), the superb Mexican muralist, made significant contributions to the art of medicine and surgery unmatched by any other painter of his stature in the world. Rivera intensively embraced medical and surgical knowledge through his legendary artistic career in a manner never seen before. Rivera's first surgical theme can be traced to 1920, when he attended and drew the wonders of the surgical operation of Dr. Fauré in Paris. The artist was particularly moved by surgical and medical events, and this surgical clinic enhanced his appetite for these important professional activities. In 1932, Rivera introduced several medico-surgical panels in Detroit automobile industry frescos. Among them, vaccination, the human embryo, the pharmaceutical industry, the germ cell, and surgery are the most representative themes included. Two years later, in Man, Controller of the Universe, the artist emphasized the effect disease and technology had on the rest of humanity. In 1944, Rivera produced The History of Cardiology, two movable extraordinary frescos that represent the history of this field of medicine. In 1953, the creative vein of this prodigious genius created The History of Medicine in Mexico, in which medicine and surgery are exceptionally well-conceived and analyzed. In brief, Rivera incorporated the best of his art and knowledge into the better understanding of medicine and surgery as he saw it during his outstanding artistic life.
A higher categorical analogue of topological T-duality for sphere bundles
Lind, John A; Westerland, Craig
2016-01-01
We introduce a periodic form of the iterated algebraic K-theory of ku, the (connective) complex K-theory spectrum, as well as a natural twisting of this cohomology theory by higher gerbes. Furthermore, we prove a form of topological T-duality for sphere bundles oriented with respect to this theory.
On $K$-theory automorphisms related to bundles of finite order
Ershov, A. V.
2009-01-01
In the present paper we describe the action of (not necessarily line) bundles of finite order on the $K$-functor in terms of classifying spaces. This description might provide with an approach for more general twistings in $K$-theory than ones related to the action of the Picard group.
Scalable synthesis of aligned carbon nanotubes bundles using green natural precursor: neem oil
Kumar, Rajesh; Tiwari, Radhey Shyam; Srivastava, Onkar Nath
2011-12-01
Practical application of aligned carbon nanotubes (ACNTs) would have to be determined by a matter of its economical and large-scale preparation. In this study, neem oil (also named Margoaa oil, extracted from the seeds of the neem-- Azadirachta indica) was used as carbon source to fabricate the bundles of ACNTs. ACNTs have been synthesized by spray pyrolysis of neem oil and ferrocene mixture at 825°C. The major components of neem oil are hydrocarbon with less amount of oxygen, which provided the precursor species in spray pyrolysis growth of CNTs. The bundles of ACNTs have been grown directly inside the quartz tube. The as-grown ACNTs have been characterized through Raman spectroscopy, scanning and transmission electron microscopic (SEM/TEM) techniques. SEM images reveal that the bundles of ACNTs are densely packed and are of several microns in length. High-resolution TEM analysis reveals these nanotubes to be multi-walled CNTs. These multi-walled CNTs were found to have inner diameter between 15 and 30 nm. It was found that present technique gives high yield with high density of bundles of ACNTs.
Scalable synthesis of aligned carbon nanotubes bundles using green natural precursor: neem oil
Directory of Open Access Journals (Sweden)
Kumar Rajesh
2011-01-01
Full Text Available Abstract Practical application of aligned carbon nanotubes (ACNTs would have to be determined by a matter of its economical and large-scale preparation. In this study, neem oil (also named Margoaa oil, extracted from the seeds of the neem--Azadirachta indica was used as carbon source to fabricate the bundles of ACNTs. ACNTs have been synthesized by spray pyrolysis of neem oil and ferrocene mixture at 825°C. The major components of neem oil are hydrocarbon with less amount of oxygen, which provided the precursor species in spray pyrolysis growth of CNTs. The bundles of ACNTs have been grown directly inside the quartz tube. The as-grown ACNTs have been characterized through Raman spectroscopy, scanning and transmission electron microscopic (SEM/TEM techniques. SEM images reveal that the bundles of ACNTs are densely packed and are of several microns in length. High-resolution TEM analysis reveals these nanotubes to be multi-walled CNTs. These multi-walled CNTs were found to have inner diameter between 15 and 30 nm. It was found that present technique gives high yield with high density of bundles of ACNTs.
DEFF Research Database (Denmark)
Eichhorn, V; Fatikow, S; Sardan Sukas, Özlem;
2010-01-01
In this paper, a novel nanorobotic strategy for non-destructive and direct electrical characterization of as-grown bundles of single-walled carbon nanotubes (SWCNTs) is presented. For this purpose, test patterns of SWCNT bundles having different diameters are grown on a silicon substrate by chemi......In this paper, a novel nanorobotic strategy for non-destructive and direct electrical characterization of as-grown bundles of single-walled carbon nanotubes (SWCNTs) is presented. For this purpose, test patterns of SWCNT bundles having different diameters are grown on a silicon substrate...... by chemical vapor deposition. A new design of microstructured four-point-probes is proposed and fabricated allowing for direct contacting of vertically aligned bundles of SWCNTs. A nanorobotic setup is upgraded into a dual endeffector system to achieve good electrical contact between four...
Hydrodynamic Experiments for a Flow Distribution of a 61-pin Wire-wrapped Rod Bundle
Energy Technology Data Exchange (ETDEWEB)
Chang, S. K.; Euh, D. J.; Choi, H. S.; Kim, H. M.; Ko, Y. J.; Lee, D. W.; Lee, H. Y.; Choi, S. R. [KAERI, Daejeon (Korea, Republic of)
2015-05-15
Fuel assembly of the SFR (Sodium-cooled Fast breeder Reactor) type reactor generally has wire spacers which are wrapped around each fuel pin helically in axial direction. The configuration of a helical wire spacer guarantees the fuel rods integrity by providing the bundle rigidity, proper spacing between rods and promoting coolant mixing between subchannels. It is important to understand the flow characteristics in such a triangular array wire wrapped rod bundle in a hexagonal duct. The experimental work has been undertaken to quantify the friction and mixing parameters which characterize the flow distribution in subchannels for the KAERI's own bundle geometric configuration. This work presents the hydrodynamic experimental results for the flow distribution and the pressure drop in subchannels of a 61-pin wire wrapped rod bundle which has been fabricated considering the hydraulic similarity of the reference reactor. Hydrodynamic experiments for a 61-pin wire wrapped test assembly has been performed to provide the data of a flow distribution and pressure losses in subchannels for verifying the analysis capability of subchannel analysis codes for a KAERI's own prototype SFR reactor. Three type of sampling probes have been specially designed to conserve the shape of the flow area for each type of subchannels. All 126 subchannels have been measured to identify the characteristics of the flow distribution in a 37-pin rod assembly. Pressure drops at the interior and the edge subchannels have been also measured to recognize the friction losses of each type of subchannels.
Line Bundles Over Families of (SUPER) Riemann Surfaces. II: The Graded Case
Bruzzo, U.; Perez, J. A. Dominguez
1992-01-01
A relative Picard theory in the context of graded manifolds is introduced. A Berezinian calculus and a theory of connections over SUSY-curves are systematically developed, and used to prove a Gauss-Bonnet theorem for line bundles in that setting and to discuss the validity of a flatness theorem
Line Bundles Over Families of (SUPER) Riemann Surfaces; 2, The Graded Case
Bruzzo, U
1992-01-01
A relative Picard theory in the context of graded manifolds is introduced. A Berezinian calculus and a theory of connections over SUSY-curves are systematically developed, and used to prove a Gauss-Bonnet theorem for line bundles in that setting and to discuss the validity of a flatness theorem
Line bundles over families of (super) Riemann surfaces. II: The graded case
Bruzzo, U.; Domínguez Pérez, J. A.
1993-04-01
A relative Picard theory in the context of graded manifolds is introduced. A Berezinian calculus and a theory of connections over SUSY-curves are systematically developed, and used to prove a Gauss-Bonnet theorem for line bundles in that setting and to discuss the validity of a flatness theorem.
Weak point property and sections of Picard bundles on a compactified Jacobian over a nodal curve
Indian Academy of Sciences (India)
USHA N BHOSLE; SANJAY SINGH
2016-08-01
We show that the compactified Jacobian (and its desingularization) of an integral nodal curve $Y$ satisfies the weak point property and the Jacobian of $Y$ satisfies the diagonal property. We compute some cohomologies of Picard bundles on the compactified Jacobian and its desingularization
Thermalhydraulics of advanced 37-element fuel bundle in crept pressure tubes
Directory of Open Access Journals (Sweden)
Park Joo Hwan
2016-01-01
Full Text Available A CANDU-6 reactor, which has 380 fuel channels of a pressure tube type, is suffering from aging or creep of the pressure tubes. Most of the aging effects for the CANDU primary heat transport system were originated from the horizontal crept pressure tubes. As the operating years of a CANDU reactor proceed, a pressure tube experiences high neutron irradiation damage under high temperature and pressure. The crept pressure tube can deteriorate the Critical Heat Flux (CHF of a fuel channel and finally worsen the reactor operating performance and thermal margin. Recently, the modification of the central subchannel area with increasing inner pitch length of a standard 37-element fuel bundle was proposed and studied in terms of the dryout power enhancement for the uncrept pressure tube since a standard 37-element fuel bundle has a relatively small flow area and high flow resistance at the central region. This study introduced a subchannel analysis for the crept pressure tubes loaded with the inner pitch length modification of a standard 37-element fuel bundle. In addition, the subchannel characteristics were investigated according to the flow area change of the center subchannels for the crept pressure tubes. Also, it was discussed how much the crept pressure tubes affected the thermalhydraulic characteristics of the fuel channel as well as the dryout power for the modification of a standard 37-element fuel bundle.
Bochner-Hartogs type extension theorem for roots and logarithms of holomorphic line bundles
Ivashkovich, Sergey
2011-01-01
We prove an extension theorem for roots and logarithms of holomorphic line bundles across strictly pseudoconcave boundaries: they extend in all cases except one, when dimension and Morse index of a critical point is two. In that case we give an explicit description of obstructions to the extension.
The Development of Lexical Bundle Accuracy and Production in English Second Language Speakers
Crossley, Scott; Salsbury, Thomas Lee
2011-01-01
Six adult, second language (L2) English learners were observed over a period of one year to explore the development of lexical bundles (i.e., bigrams) in naturally produced, oral English. Total bigrams produced by the L2 learners over the year of observation that were shared with native speakers were compared using a frequency index to explore L2…
Input modelling of ASSERT-PV V2R8M1 for RUFIC fuel bundle
International Nuclear Information System (INIS)
This report describes the input modelling for subchannel analysis of CANFLEX-RU (RUFIC) fuel bundle which has been developed for an advanced fuel bundle of CANDU-6 reactor, using ASSERT-PV V2R8M1 code. Execution file of ASSERT-PV V2R8M1 code was recently transferred from AECL under JRDC agreement between KAERI and AECL. SSERT-PV V2R8M1 which is quite different from COBRA-IV-i code has been developed for thermalhydraulic analysis of CANDU-6 fuel channel by subchannel analysis method and updated so that 43-element CANDU fuel geometry can be applied. Hence, ASSERT code can be applied to the subchannel analysis of RUFIC fuel bundle. The present report was prepared for ASSERT input modelling of RUFIC fuel bundle. Since the ASSERT results highly depend on user's input modelling, the calculation results may be quite different among the user's input models. The objective of the present report is the preparation of detail description of the background information for input data and gives credibility of the calculation results
Kepler's theory of force and his medical sources.
Regier, Jonathan
2014-01-01
Johannes Kepler (1571-1630) makes extensive use of souls and spiritus in his natural philosophy. Recent studies have highlighted their importance in his accounts of celestial generation and astrology. In this study, I would like to address two pressing issues. The first is Kepler's context. The biological side of his natural philosophy is not naively Aristotelian. Instead, he is up to date with contemporary discussions in medically flavored natural philosophy. I will examine his relationship to Melanchthon's anatomical-theological Liber de anima (1552) and to Jean Femel's very popular Physiologia (1567), two Galenic sources with a noticeable impact on how he understands the functions of life. The other issue that will direct my article is force at a distance. Medical ideas deeply inform Kepler's theories of light and solar force (virtus motrix). It will become clear that they are not a hindrance even to the hardcore of his celestial physics. Instead, he makes use of soul and spiritus in order to develop a fully mathematized dynamics. PMID:24988759
Kepler's theory of force and his medical sources.
Regier, Jonathan
2014-01-01
Johannes Kepler (1571-1630) makes extensive use of souls and spiritus in his natural philosophy. Recent studies have highlighted their importance in his accounts of celestial generation and astrology. In this study, I would like to address two pressing issues. The first is Kepler's context. The biological side of his natural philosophy is not naively Aristotelian. Instead, he is up to date with contemporary discussions in medically flavored natural philosophy. I will examine his relationship to Melanchthon's anatomical-theological Liber de anima (1552) and to Jean Femel's very popular Physiologia (1567), two Galenic sources with a noticeable impact on how he understands the functions of life. The other issue that will direct my article is force at a distance. Medical ideas deeply inform Kepler's theories of light and solar force (virtus motrix). It will become clear that they are not a hindrance even to the hardcore of his celestial physics. Instead, he makes use of soul and spiritus in order to develop a fully mathematized dynamics.
CFD analyses of flow structures in air-ingress and rod bundle problems
Wei, Hong-Chan
Two topics from nuclear engineering field are included in this dissertation. One study is the air-ingress phenomenon during a loss of coolant accident (LOCA) scenario, and the other is a 5-by-5 bundle assembly with a PWR design. The objectives were to investigate the Kelvin-Helmholtz instability of the gravity-driven stratified flows inside a coaxial pipe and the effects caused by two types of spacers at the downstream of the rod bundle. Richardson extrapolation was used for the grid independent study. The simulation results show good agreements with the experiments. Wavelet analysis and Proper Orthogonal Decomposition (POD) were used to study the flow behaviors and flow patterns. For the air-ingress phenomenon, Brunt-Vaisala frequency, or buoyancy frequency, predicts a frequency of 2.34 Hz; this is confirmed by the dominant frequency of 2.4 Hz obtained from the wavelet analysis between times 1.2 s and 1.85 s. For the rod bundle study, the dominant frequency at the center of the subchannel was determined to be 2.4 Hz with a secondary dominant frequency of 4 Hz and a much minor frequency of 6 Hz. Generally, wavelet analysis has much better performance than POD, in the air-ingress phenomenon, for a strongly transient scenario; they are both appropriate for the rod bundle study. Based on this study, when the fluid pair in a real condition is used, the time which air intrudes into the reactor is predictable.
Directory of Open Access Journals (Sweden)
Timo Maier
Full Text Available Filamentous actin is one of the most important cytoskeletal elements. Not only is it responsible for the elastic properties of many cell types, but it also plays a vital role in cellular adhesion and motility. Understanding the bundling kinetics of actin filaments is important in the formation of various cytoskeletal structures, such as filopodia and stress fibers. Utilizing a unique pillar-structured microfluidic device, we investigated the time dependence of bundling kinetics of pillar supported free-standing actin filaments. Microparticles attached to the filaments allowed the measurement of thermal motion, and we found that bundling takes place at lower concentrations than previously found in 3-dimensional actin gels, i.e. actin filaments formed bundles in the presence of 5-12 mM of magnesium chloride in a time-dependent manner. The filaments also displayed long term stability for up to hours after removing the magnesium ions from the buffer, which suggests that there is an extensive hysteresis between cation induced crosslinking and decrosslinking.
Metallic/semiconducting ratio of carbon nanotubes in a bundle prepared using CVD technique
Indian Academy of Sciences (India)
Khurshed Ahmad Shah; S S Islam; H S Mavi; A K Shukla; Harsh
2006-08-01
We present an investigation of the nature of single-walled carbon nanotubes (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 SWNT bundle sample prepared by chemical vapor deposition (CVD) technique using iron catalyst at 800° C. The detailed analysis in the present study is focused on peak positions 162 cm-1, 186 cm-1, and 216 cm-1. The first step of the analysis is to construct a list of possible (, ) pairs from the diameters calculated from the RBM peak positions. The parameters of SWNTs studied gives in-depth understanding of many symmetry, resonance and characteristic properties of SWNT bundles. Our results indicate that the contribution of metallic SWNTs in the bundle is small at RBM peak positions 162 cm-1, 186 cm-1 and in agreement with pervious results at peak position 216 cm-1.
Effect of four-alpha-helix bundle cavity size on volatile anesthetic binding energetics.
Manderson, Gavin A; Michalsky, Stuart J; Johansson, Jonas S
2003-09-30
Currently, it is thought that inhalational anesthetics cause anesthesia by binding to ligand-gated ion channels. This is being investigated using four-alpha-helix bundles, small water-soluble analogues of the transmembrane domains of the "natural" receptor proteins. The study presented here specifically investigates how multiple alanine-to-valine substitutions (which each decrease the volume of the internal binding cavity by 38 A(3)) affect structure, stability, and anesthetic binding affinity of the four-alpha-helix bundles. Structure remains essentially unchanged when up to four alanine residues are changed to valine. However, stability increases as the number of these substitutions is increased. Anesthetic binding affinities are also affected. Halothane binds to the four-alpha-helix bundle variants with 0, 1, and 2 substitutions with equivalent affinities but binds to the variants with 3 and 4 more tightly. The same order of binding affinities was observed for chloroform, although for a particular variant, chloroform was bound less tightly. The observed differences in binding affinities may be explained in terms of a modulation of van der Waals and hydrophobic interactions between ligand and receptor. These, in turn, could result from increased four-alpha-helix bundle binding cavity hydrophobicity, a decrease in cavity size, or improved ligand/receptor shape complementarity.
Three-dimensional Effects of Turburlent Flow in an In-Line Tube Bundle
DEFF Research Database (Denmark)
Meyer, Knud Erik
1998-01-01
Velocities have been measured with laser Doppler anemometry between tubes in cross-flow in a small in-line tube bundle with longitudinal to transverse pitches of 1.5Dx1.8D and a Reynolds number based on mean velocity in minimum flow section of Re=30000. At most locations a single recirculation zone...
The Effect of Lexical Bundles on Iranian EFL Learners Linguistic Production Fluency
Ranjbar, Nosrat; Pazhakh, Abdolreza; Gorjian, Bahman
2012-01-01
The present study attempted to investigate the effects of lexical bundles on Iranian EFL learners' paragraph writing production fluency. To achieve this purpose, an English language proficiency test was administered to 120 language learners studying TEFL at Islamic Azad University of Dehloran. Ultimately, 90 language learners were selected and…
International Nuclear Information System (INIS)
Innovative nuclear reactor concepts like accelerator driven systems (ADS) or the lead cooled fast reactor LFR employ lead bismuth eutectic (LBE) as a coolant. Within the framework of the EU project THINS (thermalhydraulics of innovative nuclear systems) a rod bundle experiment in LBE is performed employing characteristic dimensions at the Karlsruhe Liquid Metal Laboratory (KALLA)l of Karlsruhe Institute of Technology (KIT). In a first measurement campaign it is observed that the pressure drop across the first spacer in the rod bundle experiment is noticeable larger than at the subsequent spacers. We speculate that this is due to blockage of the very narrow spacer channels and numerically investigate whether there are substantially enhanced entrance effects. The present numerical study investigates the whole rod bundle including the entrance region in order to show possible mechanisms which can increase the pressure drop of the first spacer even if no blockage is present. The extra pressure loss compared to simulations with uniform inflow is found to be very small which supports the speculation of blockage. Since rod bundle flow is known to depend very sensitive on turbulence models and mesh resolution we carefully verify that our simulations use an adequate computation domain, mesh resolution and turbulence model. (author)
A Reappraisal of Bennett Reimer and His Meanings of Art
Allsup, Randall Everett; Lewis, Judy
2015-01-01
Consistent throughout his writings on aesthetics and education, Bennett Reimer maintained the idea that music must be understood and studied as non-conceptual. Music's forms of knowing point to the subjective realms of life and operate effectively without the assistance or necessity of language. An education in the arts is an education in…
Lacaille: astronomer, traveler. With a new translation of his journal.
Evans, D. S.
Nicolas Louis de la Caille (1713 - 1762) was the first systematic observer of the whole southern skies and delineator of fourteen new constellations in that hemisphere which survive to this day, as well as the pioneer geodesist and navigator. The book reviews the whole of his voluminous printed works and also includes a new translation of the manuscript diary of his adventurous southern voyages and travels in Brazil, South Africa and the Indian Ocean islands of Mauritius and Réunion. Illustrations include both reproductions of contemporary documents and modern photographs of some of the places which he visited.
The Stochastic Grid Bundling Method :Efficient pricing of Bermudan options and their Greeks
Jain, S.; Oosterlee, C.W.
2015-01-01
This paper describes a practical simulation-based algorithm, which we call the Stochastic Grid Bundling Metho d(SGBM) for pricing multdimensional Bermudan (i.e.discretely exercisable) options. The method generates a direct estimator of the option price, an optimal early-exercise policy as well as a
Chung, Peter J.; Song, Chaeyeon; Deek, Joanna; Miller, Herbert P.; Li, Youli; Choi, Myung Chul; Wilson, Leslie; Feinstein, Stuart C.; Safinya, Cyrus R.
2016-01-01
Tau, an intrinsically disordered protein confined to neuronal axons, binds to and regulates microtubule dynamics. Although there have been observations of string-like microtubule fascicles in the axon initial segment (AIS) and hexagonal bundles in neurite-like processes in non-neuronal cells overexpressing Tau, cell-free reconstitutions have not replicated either geometry. Here we map out the energy landscape of Tau-mediated, GTP-dependent ‘active' microtubule bundles at 37 °C, as revealed by synchrotron SAXS and TEM. Widely spaced bundles (wall-to-wall distance Dw–w≈25–41 nm) with hexagonal and string-like symmetry are observed, the latter mimicking bundles found in the AIS. A second energy minimum (Dw–w≈16–23 nm) is revealed under osmotic pressure. The wide spacing results from a balance between repulsive forces, due to Tau's projection domain (PD), and a stabilizing sum of transient sub-kBT cationic/anionic charge–charge attractions mediated by weakly penetrating opposing PDs. This landscape would be significantly affected by charge-altering modifications of Tau associated with neurodegeneration. PMID:27452526
Statistical fracture of E-glass fibres using a bundle tensile test and acoustic emission monitoring
R'Mili, M.; Moevus, M.; Godin, N.
2009-01-01
Statistical fracture of E-glass fibres using a bundle tensile test and acoustic emission monitoring correspondance: Corresponding author.Tel.: +33472436127; fax: +33472438528. (R?Mili, M.) (R?Mili, M.) Universite de Lyon--> , INSA-Lyon--> , MATEIS--> , 7 Avenue Jean Capelle--> , 69621 Villeurbanne Cedex--> - FRANCE (R?Mili, M.) Universite de Lyon--> , INSA-Lyo...
Dam, P.M. van; Proniewska, K.; Maugenest, A.M.; Mieghem, N.M. van; Maan, A.C.; Jaegere, P.P. de; Bruining, N.
2014-01-01
AIMS: Conventional electrocardiogram (ECG)-based diagnosis of left bundle branch block (LBBB) in patients with left ventricular hypertrophy (LVH) is ambiguous. Left ventricular hypertrophy is often seen in patients with severe aortic stenosis in which a transcatheter aortic valve implantation (TAVI)
Using Product Bundling to Facilitate the Adoption Process of Radical Innovations
Reinders, M.J.; Frambach, R.T.; Schoormans, J.P.L.
2010-01-01
Generally, radical innovations are not easily adopted in the market. Potential adopters experience difficulties to comprehend and evaluate radical innovations due to their newness in terms of technology and benefits offered. Consequently, adoption intentions may remain low. This paper proposes bundl
The demonstration irradiation of the CANFLEX-NU fuel bundle in Wolsong NGS 1
International Nuclear Information System (INIS)
A demonstration irradiation (DI) of 24 CANFLEX-NU fuel bundles in the high power Q07 channel and low power L21 channel of Wolsong Power Generation Station-1 had been successfully conducted jointly by KEPRI/KHNP/KAERI in the period of 2002 July to 2004 January. The tracking of the reactor operation data showed that the reactor has been stably operated during the DI. One CANFLEX bundle irradiated in the Q07 channel had a typical history of high power and high burnup, where the maximum element linear power rating was ∼ 42 kW/m at the burnup of ∼ 50 MWh/kgU and ∼ 35 kW/m at the discharge element burnup of ∼ 210 MWh/kgU. While, another CANFLEX bundles also irradiated in the Q07 channel had a typical history of power ramping, where the maximum element power ramping-up or -down rate was 28 kW/m. The unusual performance and integrity of the CANFLEX elements could not be found in the ELESTRES predictions and also the in-bay visual examinations showed that all the bundles were intact, free of defects and appeared to be in good condition as expected. Therefore, it is concluded that the demonstration irradiation shows the validation of the CANFLEX bundle performance with direct conditions of relevance under the Korean licensing requirements and the KNFC fuel fabrication capability, and provides the rationale for the decision to perform the full-conversion of CANFLEX fuel in WPGS-1. (author)
Standardization of Type 2 Diabetes Outpatient Expenditure with Bundled Payment Method in China
Institute of Scientific and Technical Information of China (English)
Guo-Chao Xu; Yun Luo; Qian Li; Meng-Fan Wu; Zi-Jun Zhou
2016-01-01
Background:In recent years,the prevalence of type 2 diabetes among Chinese population has been increasing by years,directly leading to an average annual growth rate of 19.90％ of medical expenditure.Therefore,it is urgent to work on strategies to control the growth of medical expenditure on type 2 diabetes on the basis of the reality of China.Therefore,in this study,we explored the feasibility of implementing bundled payment in China through analyzing bundled payment standards of type 2 diabetes outpatient services.Methods:This study analyzed the outpatient expenditure on type 2 diabetes with Beijing Urban Employee's Basic Medical Insurance from 2010 to 2012.Based on the analysis of outpatient expenditure and its influential factors,we adopted decision tree approach to conduct a case-mix analysis.In the end,we built a case-mix model to calculate the standard expenditure and the upper limit of each combination.Results:We found that age,job status,and whether with complication were significant factors that influence outpatient expenditure for type 2 diabetes.Through the analysis of the decision tree,we used six variables (complication,age,diabetic foot,diabetic nephropathy,cardiac-cerebrovascular disease,and neuropathy) to group the cases,and obtained 11 case-mix groups.Conclusions:We argued that it is feasible to implement bundled payment on type 2 diabetes outpatient services.Bundled payment is effective to control the increase of outpatient expenditure.Further improvements are needed for the implementation of bundled payment reimbursement standards,together with relevant policies and measures.
Experimental investigation of heat transfer from a 2 × 2 rod bundle to supercritical pressure water
Energy Technology Data Exchange (ETDEWEB)
Wang, Han [State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Bi, Qincheng, E-mail: qcbi@mail.xjtu.edu.cn [State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Wang, Linchuan; Lv, Haicai [State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Leung, Laurence K.H. [Atomic Energy of Canada Limited, Chalk River, Ont., Canada K0J 1J0 (Canada)
2014-08-15
Highlights: • Heat transfer of supercritical water through a 2 × 2 rod bundles is investigated. • Circumferential wall temperature distribution is obtained. • Effects of system parameters on heat transfer characteristics are analyzed. • Heat transfer correlations are compared against the rod bundle test data. - Abstract: Heat transfer experiments with supercritical pressure water flowing vertically upward through a 2 × 2 rod bundle have been performed at Xi’an Jiaotong University. A fuel-assembly simulator with four heated rods was installed inside a square channel with rounded corner. The outer diameter of each heated rod is 8 mm with an effective heated length of 600 mm. The experiments covered the pressure range of 23–28 MPa, mass-flux range of 350–1000 kg/(m{sup 2} s) and heat-flux range on the rod surface of 200–1000 kW/m{sup 2}. Heat transfer characteristics of supercritical pressure water through the bundle were examined with respect to variations of heat flux, system pressure, and mass flux. These characteristics were shown to be similar to those previously observed in tubes or annuli. The experimental data indicate a non-uniform circumferential wall-temperature distribution around the heated rod. A maximum wall temperature was observed at the surface facing the corner gap between the heated rod and the ceramic tube, while the minimum wall temperature was observed at the surface facing the center subchannel. The difference between maximum and minimum wall temperatures varies with heat flux and/or mass flux. Eight heat transfer correlations developed for supercritical water were assessed against the current set of test data. Prediction of the Jackson correlation agrees closely with the experimental Nusselt number. A new correlation has been derived based on Jackson correlation to improve the prediction accuracy of supercritical heat transfer coefficient in a 2 × 2 rod bundle.
Measurements of turbulent flows in a 2 × 2 rod bundle
International Nuclear Information System (INIS)
Turbulence models such as the k–ε model have been used in numerical predictions of turbulent flows in rod bundles. However, the validation of the turbulence models is not an easy task mainly due to the lack of experimental data on turbulent flows in rod bundles. In this study, we therefore measured three-dimensional velocity and turbulence intensities of water flows in a 2 × 2 rod bundle by using a particle image velocimetry (PIV) system. The diameter and pitch of the rods were 20 and 25 mm, respectively. The mean velocity ranged from 1 to 2 m/s. To measure the velocity distributions in the subchannels, the rod in the measurement region was made of fluorinated ethylene propylene (FEP) resin, the refractive index of which is almost the same as that of water. The time-averaged velocity and turbulent intensities at each measurement point were obtained from 10,000 instantaneous velocities. Time-series velocity distributions were also acquired to understand the motion of turbulence eddies in the subchannel. The experimental results indicate that the axial mean velocity along the line normal to the rod in the inner subchannel agrees well with the one-seventh power law, and that the velocity fluctuation in the direction normal to the rod wall becomes weak in the rod gap. Numerical simulations using the k–ε models were carried out to examine their applicability to the turbulent flow in the rod bundle. They gave reasonable predictions for the distribution of the axial velocity in the rod bundle and the flow rate in each subchannel.
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...
Augustine as a Reader of His Christian Contemporaries
Williams, Michael Stuart
2012-01-01
Augustine was not a great reader of his Christian contemporaries. That is to say, he seems not to have expended every energy (as might be expected of a modern scholar) in keeping up with the very latest to have been written on every topic on which he pronounced, or in which he could claim an interest. Part of the reason for this must be his relatively late conversion to Christianity. For as O’Donnell has pointed out, Augustine the professor of rhetoric – as he was by the time h...
Energy Technology Data Exchange (ETDEWEB)
Nezamzadeh, Marzieh, E-mail: marzieh.nezamzadeh@ucsf.ed [Center for Imaging of Neurodegenerative Diseases, CIND, Veterans Affairs Medical Center, San Francisco, CA (United States); Radiology, University of California San Francisco, San Francisco (United States); Wedeen, Van J.; Wang Ruopeng [Radiology, Massachusetts Harvard General Hospital, Boston (United States); Zhang Yu; Zhan Wang; Young, Karl; Meyerhoff, Dieter J.; Weiner, Michael W.; Schuff, Norbert [Center for Imaging of Neurodegenerative Diseases, CIND, Veterans Affairs Medical Center, San Francisco, CA (United States); Radiology, University of California San Francisco, San Francisco (United States)
2010-07-15
Diffusion spectrum imaging (DSI) is a generalization of diffusion tensor imaging to map fibrous structure of white matter and potentially very sensitive to alterations of the cingulum bundles in dementia. In this in-vivo 4T study, DSI parameters especially spatial resolution and diffusion encoding bandwidth were optimized on humans to segment the cingulum bundles for tract level measurements of diffusion. The careful tailoring of the DSI acquisitions in conjunction with fiber tracking provided an optimal DSI setting for a reliable quantification of the cingulum bundle tracts. The optimization of tracking the cingulum bundle was verified using fiber tract quantifications, including coefficients of variability of DSI measurements along the fibers between and within healthy subjects in back-to-back studies and variogram analysis of spatial correlations between diffusion orientation distribution functions (ODF) along the cingulum bundle tracts. The results demonstrate that the identification of the cingulum bundle in human brain is reproducible using an optimized DSI parameter for maximum b-value and high spatial resolution of the DSI acquisition with a feasible acquisition time of whole brain in clinical practice. This optimized DSI setting should be useful for detecting alterations along the cingulum bundle in Alzheimer disease and related neurodegenerative disorders.
THE PUPIL AS THE SUBJECT OF HIS EDUCATIONAL ACTIVITY
Selivanova, Olga
2014-01-01
The article describes the author΄s approach to the formation of subjectivity of the pupil in his educational activity and the relationship between the main concepts. The author regards subjectivity of the pupil as a pedagogical phenomena and characterizes the set of the pedagogical conditions of the formation of it.
Antonio Gramsci and His Relevance for the Education of Adults
Mayo, Peter
2008-01-01
This paper, drawing on original sources, provides an overview of and a discussion on those writings and ideas, in Antonio Gramsci's huge corpus of work, that are relevant to the education of adults. This should provide a fitting tribute to this major social theorist of the 20th century on the 70th anniversary of his death. Among the topics…
[A toddler with a swelling of his penis].
Staps, P; Smeets, C C J M
2016-01-01
A 4-year-old boy presented with a subcutaneous, yellowish swelling of 0.8 by 1.5 cm on his penis. We made the diagnosis of a smegma retention cyst. This cyst is the result of a physiologic phenomenon that originates from the separation of the foreskin. PMID:27405570
Nuclear regulations for the protection of man and his environment
International Nuclear Information System (INIS)
This article describes in brief the activities of the Philippine Atomic Energy Commission (PAEC) in the exercise of its regulatory function to safeguard man and his environment in the operation of the first Philippine Nuclear Power Plant (PNPP-1). PAEC's role includes regulations, quality assurance, audit, regulatory research and radiological emergency planning. (ELC)
Magnus Strandqvist: 50th anniversary of his doctoral thesis.
Kajanti, M J
1994-01-01
This article is dedicated to Magnus Strandqvist's famous doctoral thesis "Studien über die kumulative Wirkung der Röntgenstrahlen bei Fraktionierung. Erfahrungen aus dem Radiumhemmet an 280 Haut- und Lippenkarzinomen" published in Acta Radiologica in 1944. After a short biography of Strandqvist some central points of his work and their influence on future development of modern radiotherapy are presented. PMID:7993639
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 $E$.
Dismantling and decontamination of the tube bundle of a feedwater preheater of the Garigliano BWR
International Nuclear Information System (INIS)
The report deals with dismantling and decontamination of the tube bundle of a feedwater preheater of Garigliano-BWR. Decontamination is a common practice in decommissioning works and it can be used both for reducing radiation exposures, in order to save manrem, and for the unrestricted release of materials. In this latter field the decontamination of tube bundle is a particular case because of their large contaminated surfaces and relatively low weight; at the moment no decon technique was available on the market to decontaminate up to the unrestricted release the materials of tube bundles. In this context an innovative decon technique using aggressive chemicals together with ultrasounds in a tank, was developed by several laboratories and assessed with in-scale testings. A decon procedure considering two phases: first with ultrasounds applied in water at 600C, and second with ultrasounds applied in a solution of HF/HNO3 acids at 60-700C, was qualified. The demonstration of the performances of the new technique under real conditions was made by performing ten full-scale demo tests, each one on an assembly of 100 straight tubes, 1 m long each, for a total of 1000 meters
Le, Cui; Wanxi, Peng; Zhengjun, Sun; Lili, Shang; Guoning, Chen
2014-07-01
Bamboo is a radial gradient variation composite material against parasitology and vector biology, but the vascular bundles in inner layer are evenly distributed. The objective is to determine the regular size pattern and Weibull statistical analysis of the vascular bundle tensile strength in inner layer of Moso bamboo. The size and shape of vascular bundles in inner layer are similar, with an average area about 0.1550 mm2. A statistical evaluation of the tensile strength of vascular bundle was conducted by means of Weibull statistics, the results show that the Weibull modulus m is 6.1121 and the accurate reliability assessment of vascular bundle is determined.
Propagation velocity profile in a cross-section of a cardiac muscle bundle from PSpice simulation
Directory of Open Access Journals (Sweden)
Sperelakis Nicholas
2006-08-01
Full Text Available Abstract Background The effect of depth on propagation velocity within a bundle of cardiac muscle fibers is likely to be an important factor in the genesis of some heart arrhythmias. Model and methods The velocity profile of simulated action potentials propagated down a bundle of parallel cardiac muscle fibers was examined in a cross-section of the bundle using a PSpice model. The model (20 × 10 consisted of 20 chains in parallel, each chain being 10 cells in length. All 20 chains were stimulated simultaneously at the left end of the bundle using rectangular current pulses (0.25 nA, 0.25 ms duration applied intracellularly. The simulated bundle was symmetrical at the top and bottom (including two grounds, and voltage markers were placed intracellularly only in cells 1, 5 and 10 of each chain to limit the total number of traces to 60. All electrical parameters were standard values; the variables were (1 the number of longitudinal gap-junction (G-j channels (0, 1, 10, 100, (2 the longitudinal resistance between the parallel chains (Rol2 (reflecting the closeness of the packing of the chains, and (3 the bundle termination resistance at the two ends of the bundle (RBT. The standard values for Rol2 and RBT were 200 KΩ. Results The velocity profile was bell-shaped when there was 0 or only 1 gj-channel. With standard Rol2 and RBT values, the velocity at the surface of the bundle (θ1 and θ20 was more than double (2.15 × that at the core of the bundle (θ10, θ11. This surface:core ratio of velocities was dependent on the values of Rol2 and RBT. When Rol2 was lowered 10-fold, θ1 increased slightly and θ2decreased slightly. When there were 100 gj-channels, the velocity profile was flat, i.e. the velocity at the core was about the same as that at the surface. Both velocities were more than 10-fold higher than in the absence of gj-channels. Varying Rol2 and RBT had almost no effect. When there were 10 gj-channels, the cross-sectional velocity profile
Algebraic cohomology of the moduli space of rank 2 vector bundles on a curve
Balaji, V; Newstead, P E; Balaji, V; King, A D; Newstead, P E
1995-01-01
Let \\MC be the moduli space of stable holomorphic vector bundles of rank 2 and fixed determinant of odd degree, over a smooth projective curve C. This paper identifies the algebraic cohomology ring \\HA^*(\\MC), i.e. the subring of the rational cohomology ring H^*(\\MC;\\QQ) spanned by the fundamental classes of algebraic cycles, in terms of the algebraic cohomology ring of the Jacobian \\JC.
Fiber Bundles and Parseval Frames
Agrawal, Devanshu; Knisley, Jeff
2015-01-01
Continuous frames over a Hilbert space have a rich and sophisticated structure that can be represented in the form of a fiber bundle. The fiber bundle structure reveals the central importance of Parseval frames and the extent to which Parseval frames generalize the notion of an orthonormal basis.
The Role of Cyclo(His-Pro) in Neurodegeneration
Grottelli, Silvia; Ferrari, Ilaria; Pietrini, Grazia; Peirce, Matthew J.; Minelli, Alba; Bellezza, Ilaria
2016-01-01
Neurodegenerative diseases may have distinct genetic etiologies and pathological manifestations, yet share common cellular mechanisms underpinning neuronal damage and dysfunction. These cellular mechanisms include excitotoxicity, calcium dysregulation, oxidative damage, ER stress and neuroinflammation. Recent data have identified a dual role in these events for glial cells, such as microglia and astrocytes, which are able both to induce and to protect against damage induced by diverse stresses. Cyclo(His-Pro), a cyclic dipeptide derived from the hydrolytic removal of the amino-terminal pyroglutamic acid residue of the hypothalamic thyrotropin-releasing hormone, may be important in regulating the nature of the glial cell contribution. Cyclo(His-Pro) is ubiquitous in the central nervous system and is a key substrate of organic cation transporters, which are strongly linked to neuroprotection. The cyclic dipeptide can also cross the brain-blood-barrier and, once in the brain, can affect diverse inflammatory and stress responses by modifying the Nrf2-NF-κB signaling axis. For these reasons, cyclo(His-Pro) has striking potential for therapeutic application by both parenteral and oral administration routes and may represent an important new tool in counteracting neuroinflammation-based degenerative pathologies. In this review, we discuss the chemistry and biology of cyclo(His-Pro), how it may interact with the biological mechanisms driving neurodegenerative disease, such as amyotrophic lateral sclerosis, and thereby act to preserve or restore neuronal function. PMID:27529240
The Role of Cyclo(His-Pro) in Neurodegeneration.
Grottelli, Silvia; Ferrari, Ilaria; Pietrini, Grazia; Peirce, Matthew J; Minelli, Alba; Bellezza, Ilaria
2016-01-01
Neurodegenerative diseases may have distinct genetic etiologies and pathological manifestations, yet share common cellular mechanisms underpinning neuronal damage and dysfunction. These cellular mechanisms include excitotoxicity, calcium dysregulation, oxidative damage, ER stress and neuroinflammation. Recent data have identified a dual role in these events for glial cells, such as microglia and astrocytes, which are able both to induce and to protect against damage induced by diverse stresses. Cyclo(His-Pro), a cyclic dipeptide derived from the hydrolytic removal of the amino-terminal pyroglutamic acid residue of the hypothalamic thyrotropin-releasing hormone, may be important in regulating the nature of the glial cell contribution. Cyclo(His-Pro) is ubiquitous in the central nervous system and is a key substrate of organic cation transporters, which are strongly linked to neuroprotection. The cyclic dipeptide can also cross the brain-blood-barrier and, once in the brain, can affect diverse inflammatory and stress responses by modifying the Nrf2-NF-κB signaling axis. For these reasons, cyclo(His-Pro) has striking potential for therapeutic application by both parenteral and oral administration routes and may represent an important new tool in counteracting neuroinflammation-based degenerative pathologies. In this review, we discuss the chemistry and biology of cyclo(His-Pro), how it may interact with the biological mechanisms driving neurodegenerative disease, such as amyotrophic lateral sclerosis, and thereby act to preserve or restore neuronal function. PMID:27529240
On the Properties of a Bundle of Flexible Actin Filaments in an Optical Trap
Perilli, Alessia; Ciccotti, Giovanni; Ryckaert, Jean Paul
2016-01-01
We establish the Statistical Mechanics framework for a bundle of Nf living and uncrosslinked actin filaments in a supercritical solution of free monomers pressing against a mobile wall. The filaments are anchored normally to a fixed planar surface at one of their ends and, because of their limited flexibility, they grow almost parallel to each other. Their growing ends hit a moving obstacle, depicted as a second planar wall, parallel to the previous one and subjected to a harmonic compressive force. The force constant is denoted as trap strength while the distance between the two walls as trap length to make contact with the experimental optical trap apparatus. For an ideal solution of reactive filaments and free monomers at fixed free monomers chemical potential, we obtain the general expression for the grand potential from which we derive averages and distributions of relevant physical quantities, namely the obstacle position, the bundle polymerization force and the number of filaments in direct contact wit...
Bundle Security Protocol for ION
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.
Zipping and Entanglement in Flagellar Bundle of E. Coli: Role of Motile Cell Body
Adhyapak, Tapan Chandra
2015-01-01
The course of a peritrichous bacterium such as E. coli crucially depends on the level of synchronization and self-organization of several rotating flagella. However, the rotation of each flagellum generates counter body movements which in turn affect the flagellar dynamics. Using a detailed numerical model of an E. coli, we demonstrate that flagellar entanglement, besides fluid flow relative to the moving body, dramatically changes the dynamics of flagella from that compared to anchored flagella. In particular, bundle formation occurs through a zipping motion in a remarkably rapid time, affected little by initial flagellar orientation. A simplified analytical model supports our observations. Finally, we illustrate how entanglement, hydrodynamic interactions, and body movement contribute to zipping and bundling.
Development of neural network simulating power distribution of a BWR fuel bundle
International Nuclear Information System (INIS)
A neural network model is developed to simulate the precise nuclear physics analysis program code for quick scoping survey calculations. The relation between enrichment and local power distribution of BWR fuel bundles was learned using two layers neural network (ENET). A new model is to introduce burnable neutron absorber (Gadolinia), added to several fuel rods to decrease initial reactivity of fresh bundle. The 2nd stages three layers neural network (GNET) is added on the 1st stage network ENET. GNET studies the local distribution difference caused by Gadolinia. Using this method, it becomes possible to survey of the gradients of sigmoid functions and back propagation constants with reasonable time. Using 99 learning patterns of zero burnup, good error convergence curve is obtained after many trials. This neural network model is able to simulate no learned cases fairly as well as the learned cases. Computer time of this neural network model is about 100 times faster than a precise analysis model. (author)
EXPERIMENTAL STUDY OF ENHANCED HEAT TRANSFER BY FLOW-INDUCED VIBRATION OF ELASTIC TUBE BUNDLES
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
A new concept of heat transfer enhancement by flow-induced vibration was put forward, and a novel heat transfer element called elastic tube bundles was designed. The experimental investigation was performed on its characteristics of flow-induced virbration in out-tube or in-tube flow. Under the conditions of fixed heat flux and steam-water heat transfer, the regularity of heat transfer enhancement by flow-induced vibration was examined.
Section Extension from Hyperbolic Geometry of Punctured Disk and Holomorphic Family of Flat Bundles
Siu, Yum-Tong
2011-01-01
We study the problem of constructing pluricanonical sections from flatly twisted pluricanonical sections and prove that, for a compact complex algebraic manifold X and positive integers m and q, the subvariety of flat line bundles F on X such that the complex dimension of the space of all holomorphic sections of the sum of F and the m-canonical line bundle of X is at least q is regular and is a finite union of translates of abelian subvarieties by torsion elements in the abelian variety of all flat line bundles on X. The proof uses a new extension result of Ohsawa-Takegoshi type, where the curvature current is not even semi-positive but with only mild controllable negativity. We also give a new approach to the original theorem of Ohsawa-Takegoshi. Our approach considers the origin of the open unit 1-disk as the infinite point of the hyperbolic geometry of the punctured open unit 1-disk and reduces the original theorem of Ohsawa-Takegoshi to just a simple straightforward application of the standard method of c...
Application of the finite element method in the modelling of coil bundles
International Nuclear Information System (INIS)
Three different FEM approaches are presented and evaluated as viable interpretations of an actual coil, each limited for use within specified parameter ranges. One is based on solid elements with correctly defined properties permitting the accurate representation of the global behavior of a coil bundle. The other two are more complex and are based on the combination of various elements each accounting for a different aspect of coil behavior which are best resolved via multi-level substructuring. The choice of the best model for the job rests with the analyst who must first resolve what the goals of the analysis are and given the parameters of the problem, which models can be used. The basic idea behind these models is the application of a systematic modelling technique requiring a close correspondence between the capability of the FE themselves and the true mechanical behavior of that portion of the coil being simulated. In order to have analytical solutions for confirming the bending and torsional capabilities of these coil bundle FEM, their behavior is studied via several basic examples. Laminated beam behavior which categorizes the structural nature of many conventional coil bundles is also examined in some depth. Also discussed is a generalized computer program that was developed to accept the description of any conventional coil section and determine an effective stiffness for it to be used in FEM. The various methodologies described in this paper should be applicable to any bundled coil design. Although only conventional coils are discussed, with the proper modifications the concepts and techniques presented can be applied to other configurations as well, such as superconductors. (orig./HP)
Pullout tests of root analogs and natural root bundles in soil: Experiments and modeling
Schwarz, M.; Cohen, D.; Or, D.
2011-06-01
Root-soil mechanical interactions are key to soil stability on steep hillslopes. Motivated by new advances and applications of the Root Bundle Model (RBM), we conducted a series of experiments in the laboratory and in the field to study the mechanical response of pulled roots. We systematically quantified the influence of different factors such as root geometry and configuration, soil type, and soil water content considering individual roots and root bundles. We developed a novel pullout apparatus for strain-controlled field and laboratory tests of up to 13 parallel roots measured individually and as a bundle. Results highlight the importance of root tortuosity and root branching points for prediction of individual root pullout behavior. Results also confirm the critical role of root diameter distribution for realistic prediction of global pullout behavior of a root bundle. Friction between root and soil matrix varied with soil type and water content and affected the force-displacement behavior. Friction in sand varied from 1 to 17 kPa, with low values obtained in wet sand at a confining pressure of 2 kPa and high values obtained in dry sand with 4.5 kPa confining pressure. In a silty soil matrix, friction ranged between 3 kPa under wet and low confining pressure (2 kPa) and 6 kPa in dry and higher confining pressure (4.5 kPa). Displacement at maximum pullout force increased with increasing root diameter and with tortuosity. Laboratory experiments were used to calibrate the RBM that was later validated using six field measurements with natural root bundles of Norway spruce (Picea abies L.). These tests demonstrate the progressive nature of root bundle failure under strain-controlled pullout force and provide new insights regarding force-displacement behavior of root reinforcement, highlighting the importance of considering displacement in slope stability models. Results show that the magnitude of maximum root pullout forces (1-5 kPa) are important for slope
Characteristics of turbulent velocity and temperature in a wall channel of a heated rod bundle
Energy Technology Data Exchange (ETDEWEB)
Krauss, T.; Meyer, L. [Forschungszentrum Karlsruhe (Germany)
1995-09-01
Turbulent air flow in a wall sub-channel of a heated 37-rod bundle (P/D = 1.12, W/D = 1.06) was investigated. measurements were performed with hot-wire probe with X-wires and a temperature wire. The mean velocity, the mean fluid temperature, the wall shear stress and wall temperature, the turbulent quantities such as the turbulent kinetic energy, the Reynolds-stresses and the turbulent heat fluxes were measured and are discussed with respect to data from isothermal flow in a wall channel and heated flow in a central channel of the same rod bundle. Also, data on the power spectral densities of the velocity and temperature fluctuations are presented. These data show the existence of large scale periodic fluctuations are responsible for the high intersubchannel heat and momentum exchange.
On Harder–Narasimhan Reductions for Higgs Principal Bundles
Indian Academy of Sciences (India)
Arijit Dey; R Parthasarathi
2005-05-01
The existence and uniqueness of – reduction for the Higgs principal bundles over nonsingular projective variety is shown. We also extend the notion of – reduction for (, )-bundles and ramified -bundles over a smooth curve.
Maass, Wolfgang; Kowatsch, Tobias
2008-01-01
Up until now, brick-and-mortar stores provide consumers with static product information in the form of printed product labels. This kind of product information does neither adapt to consumer needs nor facilitates new business models (e.g. consumer experience or ad hoc product bundling by products itself). By contrast, dynamic product information provided by mobile recommendation agents (MRA) may leverage these limitations. In this article we formulate a Simplified Consumer Choice (SCC) model ...
Heat transfer characteristics of staggered wing-shaped tubes bundle at different angles of attack
Sayed Ahmed, Sayed Ahmed E.; Ibrahiem, Emad Z.; Mesalhy, Osama M.; Abdelatief, Mohamed A.
2014-08-01
An experimental and numerical study has been conducted to clarify heat transfer characteristics and effectiveness of a cross-flow heat exchanger employing staggered wing-shaped tubes at different angels of attack. The water-side Rew and the air-side Rea were at 5 × 102 and at from 1.8 × 103 to 9.7 × 103, respectively. The tubes arrangements were employed with various angles of attack θ1,2,3 from 0° to 330° at the considered Rea range. Correlation of Nu, St, as well as the heat transfer per unit pumping power (ɛ) in terms of Rea and design parameters for the studied bundle were presented. The temperature fields around the staggered wing-shaped tubes bundle were predicted by using commercial CFD FLUENT 6.3.26 software package. Results indicated that the heat transfer increased with the angle of attack in the range from 0° to 45°, while the opposite was true for angles of attack from 135° to 180°. The best thermal performance and hence the efficiency η of studied bundle occurred at the lowest Rea and/or zero angle of attack. Comparisons between the experimental and numerical results of the present study and those, previously, obtained for similar available studies showed good agreements.
Thermodynamics of adsorption of light alkanes and alkenes in single-walled carbon nanotube bundles
Cruz, Fernando J A L
2016-01-01
The thermodynamics of adsorption of light alkanes and alkenes (CH4, C2H6, C2H4, C3H8, and C3H6) in single-walled carbon nanotube bundles is studied by configurational-bias grand canonical Monte Carlo simulation. The bundles consist of uniform nanotubes with diameters in the range 11.0 < D (A) < 18.1, arranged in the usual close-packed hexagonal lattice. The phase space is systematically analyzed with calculations for adsorption at room temperature and reduced pressure range of 8.7 x 10-9 < (p/p0) < 0.9. The simulation results are interpreted in terms of the molecular nature of the adsorbate and the corresponding solid-fluid interactions. It is shown that confinement in the internal volume of the bundle (interstitial and intratubular) is energetically more favorable than physisorption on the external surface (grooves and exposed surfaces of peripheral tubes), as indicated by the curves of isosteric heat as a function of reduced pressure. However, the zero-loading properties suggest a crossover poin...
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.
Simulation of the response of the inner hair cell stereocilia bundle to an acoustical stimulus.
Directory of Open Access Journals (Sweden)
Sonya T Smith
Full Text Available Mammalian hearing relies on a cochlear hydrodynamic sensor embodied in the inner hair cell stereocilia bundle. It is presumed that acoustical stimuli induce a fluid shear-driven motion between the tectorial membrane and the reticular lamina to deflect the bundle. It is hypothesized that ion channels are opened by molecular gates that sense tension in tip-links, which connect adjacent stepped rows of stereocilia. Yet almost nothing is known about how the fluid and bundle interact. Here we show using our microfluidics model how each row of stereocilia and their associated tip links and gates move in response to an acoustical input that induces an orbital motion of the reticular lamina. The model confirms the crucial role of the positioning of the tectorial membrane in hearing, and explains how this membrane amplifies and synchronizes the timing of peak tension in the tip links. Both stereocilia rotation and length change are needed for synchronization of peak tip link tension. Stereocilia length change occurs in response to accelerations perpendicular to the oscillatory fluid shear flow. Simulations indicate that nanovortices form between rows to facilitate diffusion of ions into channels, showing how nature has devised a way to solve the diffusive mixing problem that persists in engineered microfluidic devices.
The Effect of Pre-teaching Extended Prefabricated Lexical Bundles on the Writing Development of
Directory of Open Access Journals (Sweden)
Seiyed Mahdi Araghi
2014-03-01
Full Text Available This study attempts to shed light on how a teacher’s instruction and guidance can cast aside writing inhibitions and bring about remarkable changes in the writing ability of advanced EFL students through the collaborative construction of extended chunks of language with the aim of enhancing lexical density and complexity and consequently injecting into learners a sense of satisfaction with their work. The sample included 40 TOEFL students selected out of 75 TOEFL students on the basis of their scores on a TOEFL test. The participants were randomly assigned into two groups-the control group and experimental group. After 20 instructional sessions both groups were assigned five writing tasks. The results reveal that the participants in experimental group outperformed their counterparts in control group. Overall, it is concluded that pre-teaching extended prefabricated lexical bundles can be a useful means of helping advanced students to improve their writing quality.Keywords: prefabricated lexical bundles, extended prefabricated lexical bundles, negative transfer, writing fluency
Pan-European management of electricity portfolios: Risks and opportunities of contract bundling
International Nuclear Information System (INIS)
Due to the liberalization of energy markets in the European Union, today's European utilities not only focus on electricity supply, but also offer exchange-traded 'structured products' or portfolio management for unbundling financial and physical risk positions. Many utilities are only able to provide these services in their domestic markets. In a globalized economy, the need for a centrally organized pan-European portfolio management has arisen, as it allows a simplified commodity sourcing in combination with an optimized risk management. In this paper, we examine the challenges to be overcome for establishing a European-wide bundling of electricity contracts. For this purpose, a case study based on the business perspective of RWE Supply and Trading in Central and Eastern Europe is carried out. In a first step, we analyze general requirements for a pan-European bundling of electricity contracts. Then, RWE's situation in Europe is examined, based on which we finally propose a concept to meet customer demands in Central and Eastern Europe. - Research highlights: → Analysis of electricity market liberalization in Central and Eastern Europe. → Identification of requirements and problems for pan-European bundling of contracts. → Case study based on RWE Supply and Trading perspective in Central and Eastern Europe. → Model development for pan-European unbundling of financial/physical risk positions.
Correction of Airborne Pushbroom Images Orientation Using Bundle Adjustment of Frame Images
Barbieux, K.; Constantin, D.; Merminod, B.
2016-06-01
To compute hyperspectral orthophotos of an area, one may proceed like for standard RGB orthophotos : equip an aircraft or a drone with the appropriate camera, a GPS and an Inertial Measurement Unit (IMU). The position and attitude data from the navigation sensors, together with the collected images, can be input to a bundle adjustment which refines the estimation of the parameters and allows to create 3D models or orthophotos of the scene. But most of the hyperspectral cameras are pushbrooms sensors : they acquire lines of pixels. The bundle adjustment identifies tie points (using their 2D neighbourhoods) between different images to stitch them together. This is impossible when the input images are lines. To get around this problem, we propose a method that can be used when both a frame RGB camera and a hyperspectral pushbroom camera are used during the same flight. We first use the bundle adjustment theory to obtain corrected navigation parameters for the RGB camera. Then, assuming a small boresight between the RGB camera and the navigation sensors, we can estimate this boresight as well as the corrected position and attitude parameters for the navigation sensors. Finally, supposing that the boresight between these sensors and the pushbroom camera is constant during the flight, we can retrieve it by matching manually corresponding pairs of points between the current projection and a reference. Comparison between the direct georeferencing and the georeferencing with our method on three flights performed during the Leman-Baikal project shows great improvement of the ground accuracy.
Simulation of cross-flow-induced vibration of tube bundle by surface vorticity method
Institute of Scientific and Technical Information of China (English)
Fenghao WANG; Gedong JIANG; Jong Zhang Lin
2008-01-01
A fluid-structure interaction model based on Surface Vorticity Method (SVM) was used to study flow-induced vibrations of tube bundles in medium space ratio. The flow-induced vibrations of four tubes in a rotated square and a staggered tube bundle in three-row and five-column arrangements were simulated in the high sub-critical Reynolds number (Re) range. The results on fluid forces, tube responses and vorticity maps were pre-sented. The vorticity maps of the four rotated-square tubes changed dramatically when the rigid tubes were replaced by the flexible tubes. From the vorticity maps and vibration responses of the staggered tube bundle of different structural parameters, it was found that with the decrease of tube natural frequency, the maximal vibration response moved from the third row to the first. The results also showed that when more flexible tubes are used, the flow pattern changed drastically and the fluid-structure interaction imposed a dominant impact on the flow.
International Nuclear Information System (INIS)
A hybrid bundle divertor design is presented that produces <0.3% magnetic ripple at the center of the plasma while providing adequate space for the coil shielding and structure for a tokamak fusion test reactor similar to the International Tokamak Reactor and the Engineering Test Facility (with R = 5 m, B = 5 T, and a /SUB wall/ = 1.5 m, in particular). This hybrid divertor consists of a set of quadrupole ''wing'' coils running tangent to the tokamak plasma on either side of a bundle divertor. The wing coils by themselves pull the edge of the plasma out 1.5 m and spread the thickness of the scrape-off layer from 0.1 to 0.7 m at the midplane. The clear aperture of the bundle divertor throat is 1.0 m high and 1.8 m wide. For maintenance or replacement, the hybrid divertor can be disassembled into three parts, with the bundle divertor part pulling straight out between toroidal field coils and the wing coils then sliding out through the same opening
Zavadlav, Julija; Marrink, Siewert J; Praprotnik, Matej
2016-08-01
The adaptive resolution scheme (AdResS) is a multiscale molecular dynamics simulation approach that can concurrently couple atomistic (AT) and coarse-grained (CG) resolution regions, i.e., the molecules can freely adapt their resolution according to their current position in the system. Coupling to supramolecular CG models, where several molecules are represented as a single CG bead, is challenging, but it provides higher computational gains and connection to the established MARTINI CG force field. Difficulties that arise from such coupling have been so far bypassed with bundled AT water models, where additional harmonic bonds between oxygen atoms within a given supramolecular water bundle are introduced. While these models simplify the supramolecular coupling, they also cause in certain situations spurious artifacts, such as partial unfolding of biomolecules. In this work, we present a new clustering algorithm SWINGER that can concurrently make, break, and remake water bundles and in conjunction with the AdResS permits the use of original AT water models. We apply our approach to simulate a hybrid SPC/MARTINI water system and show that the essential properties of water are correctly reproduced with respect to the standard monoscale simulations. The developed hybrid water model can be used in biomolecular simulations, where a significant speed up can be obtained without compromising the accuracy of the AT water model. PMID:27409519
Development of neural network for analysis of local power distributions in BWR fuel bundles
International Nuclear Information System (INIS)
A neural network model has been developed to learn the local power distributions in a BWR fuel bundle. A two layers neural network with total 128 elements is used for this model. The neural network learns 33 cases of local power peaking factors of fuel rods with given enrichment distribution as the teacher signals, which were calculated by a fuel bundle nuclear analysis code based on precise physical models. This neural network model studied well the teacher signals within 1 % error. It is also able to calculate the local power distributions within several % error for the different enrichment distributions from the teacher signals when the average enrichment is close to 2 %. This neural network is simple and the computing speed of this model is 300 times faster than that of the precise nuclear analysis code. This model was applied to survey the enrichment distribution to meet a target local power distribution in a fuel bundle, and the enrichment distribution with flat power shape are obtained within short computing time. (author)
Zavadlav, Julija; Marrink, Siewert J; Praprotnik, Matej
2016-08-01
The adaptive resolution scheme (AdResS) is a multiscale molecular dynamics simulation approach that can concurrently couple atomistic (AT) and coarse-grained (CG) resolution regions, i.e., the molecules can freely adapt their resolution according to their current position in the system. Coupling to supramolecular CG models, where several molecules are represented as a single CG bead, is challenging, but it provides higher computational gains and connection to the established MARTINI CG force field. Difficulties that arise from such coupling have been so far bypassed with bundled AT water models, where additional harmonic bonds between oxygen atoms within a given supramolecular water bundle are introduced. While these models simplify the supramolecular coupling, they also cause in certain situations spurious artifacts, such as partial unfolding of biomolecules. In this work, we present a new clustering algorithm SWINGER that can concurrently make, break, and remake water bundles and in conjunction with the AdResS permits the use of original AT water models. We apply our approach to simulate a hybrid SPC/MARTINI water system and show that the essential properties of water are correctly reproduced with respect to the standard monoscale simulations. The developed hybrid water model can be used in biomolecular simulations, where a significant speed up can be obtained without compromising the accuracy of the AT water model.
Input modelling of PHT system stability analysis for CANFLEX-RU bundle by SOPHT code
Energy Technology Data Exchange (ETDEWEB)
Park, Joo Hwan; Jun, Ji Su; Suk, Ho Chun [Korea Atomic Energy Research Institute, Taejon (Korea)
1999-01-01
The overall objective of this report is to undertake the stability analysis of primary heat transport (PHT) system for a CANDU reactor to be loaded with CANFLEX-RU bundle which is to provide a vehicle for the economic use of recycled uranium and for the economic provision of additional operating margins in aging CANDU reactors. The modelling report for the input data of SOPHT code is required in order to give the specific and accurate information for flow stability calculation. This report is consisted of the several sections which are described the usage of control cards, calculation methods for input data generation, the comparison of specific input data set for 37-element, CANFLEX-NU and CANFLEX-RU bundles and calculation results for the steady state condition. Those input data set prepared will be used for the flow stability analysis of PHT system of CANDU reactor by SOPHT code. (author). 1 ref., 2 figs., 16 tabs.
Construction report of 6 x 6 rod bundle reflood test facility (ATHER)
International Nuclear Information System (INIS)
The 6x6 reflood test facility has been constructed by KAERI to quantify rewetting mechanism and evaluate the effect of dispersed flow cooling with respect to droplet behavior. The test section consists of a simulated 6 x 6 rod bundle, a flow housing, 4 pairs of borosilicate glasses for a visual observation and instrumentation. Axial power shape of the simulated heater rod is cosine. Peaking factor and heated length of the rod bundle are 1.468 and 3,810 mm, respectively. Special features of this facility are a separator tank to measure the amount of entrained droplet and a superheated steam probe for the measurement of superheated steam temperature in sub-channel. The experimental results from this study will be useful for the performance evaluation and the program update of the related computer code
Construction report of 6 x 6 rod bundle reflood test facility (ATHER)
Energy Technology Data Exchange (ETDEWEB)
Cho, Seok; Chun, Se Young; Choi, Ki Yong; Moon, Sang Ki; Yun, Young Jung; Park, Jong Kuk; Kim, Bok Duk; Song, Chul Hwa; Baek, Won Pil
2008-10-15
The 6x6 reflood test facility has been constructed by KAERI to quantify rewetting mechanism and evaluate the effect of dispersed flow cooling with respect to droplet behavior. The test section consists of a simulated 6 x 6 rod bundle, a flow housing, 4 pairs of borosilicate glasses for a visual observation and instrumentation. Axial power shape of the simulated heater rod is cosine. Peaking factor and heated length of the rod bundle are 1.468 and 3,810 mm, respectively. Special features of this facility are a separator tank to measure the amount of entrained droplet and a superheated steam probe for the measurement of superheated steam temperature in sub-channel. The experimental results from this study will be useful for the performance evaluation and the program update of the related computer code.
Sepe, D.
2013-01-01
The obstruction to construct a Lagrangian bundle over a fixed integral affine manifold was constructed by Dazord and Delzant (J Differ Geom 26:223–251, 1987) and shown to be given by ‘twisted’ cup products in Sepe (Differ GeomAppl 29(6): 787–800, 2011). This paper uses the topology of universal Lagr
Time dependence of breakdown in a global fiber-bundle model with continuous damage
Moral, L.; Moreno, Y.; Gomez, J. B.; Pacheco, A. F.
2001-01-01
A time-dependent global fiber-bundle model of fracture with continuous damage is formulated in terms of a set of coupled non-linear differential equations. A first integral of this set is analytically obtained. The time evolution of the system is studied by applying a discrete probabilistic method. Several results are discussed emphasizing their differences with the standard time-dependent model. The results obtained show that with this simple model a variety of experimental observations can ...
International Nuclear Information System (INIS)
Thermal-hydraulic safety in a tight-lattice bundle has been analyzed to contribute thermal design of an advanced water-cooled reactor core. Since the analytical geometry is complicated, it is difficult to understand the analysis results using general visualization software. In this study, the visualization program for the thermal-hydraulic analysis in the tight-lattice bundle was developed using the software AVS/Express. It can reproduce the three-dimensional view and graphs of the analysis results and it is helpful in understanding the thermal-hydraulic phenomena in the tight-lattice bundle. (author)
Bundling Information Goods: Pricing, Profits, and Efficiency
Yannis Bakos; Erik Brynjolfsson
1999-01-01
We study the strategy of bundling a large number of information goods, such as those increasingly available on the Internet, and selling them for a fixed price. We analyze the optimal bundling strategies for a multiproduct monopolist, and we find that bundling very large numbers of unrelated information goods can be surprisingly profitable. The reason is that the law of large numbers makes it much easier to predict consumers' valuations for a bundle of goods than their valuations for the indi...
On continuous fiber bundles of C*-algebras over Stonean compact
Katz, Alexander A.; Kushnir, Roman
2011-01-01
We introduce C*-algebras over C_{\\infty}(Q,C) as Banach-Kantorovich *-algebras over the algebra C_{\\infty}(Q,C) of extended continuous complex-valued functions, defined on comeager subsets of Stonean compact Q, whose norm satisfies conditions similar to the axioms of C*-algebras, and show that such algebras can be uniquely up to a Q-C*-isomorphism represented by means of a continuous complete fiber bundle of C*-algebras over Q.
Calculation of aerial cable spacer compression forces in bundled phases during short circuit fault
I. I. Sergey; Ya. V. Potachits
2014-01-01
The paper presents an approximate method for calculation of electrodynamic resistance parameters of a flexible bus-bar with bundled phases. Comparison of the approximate calculation results with the computer calculations using a FAZA software tool has been given in the paper. An evaluation of permissible aerial cable spacer compression forces for designed modern standard distribution substations of 330 and 550 kV has been provided in the paper. The paper proposes an algorithm for determinatio...
Antonio Gramsci and his relevance for the education of adults
Mayo, Peter
2008-01-01
This paper, drawing on original sources, provides an overview of and a discussion on those writings and ideas, in Antonio Gramsci's huge corpus of work, that are relevant to the education of adults. This should provide a fitting tribute to this major social theorist of the 20th century on the 70th anniversary of his death. Among the topics discussed are those of adult education for industrial democracy, adult education and cultural preparation, adult literacy, prison education, adult educatio...
Visualization and measurement of two-phase flow in tight rod bundle by neutron tomography
International Nuclear Information System (INIS)
Neutron tomography thermal-hydraulic measurement technique is originally developed based on the neutron radiography, computed tomography and two-phase flow measurement techniques. The purpose of the developing is to measure the void fraction distribution in the Reduced-Moderation Water Reactor which is a water-cooled breeder reactor designed by the JAERI as a future reactor. We have visualized and measured the void distribution of air/water two-phase flow and boiling flow in tight-lattice rod bundles. We used the research reactor JRR-3 as a neutron source. Three-dimensional data can be obtained in order to evaluate the numerical analysis codes. In this manuscript, the neutron tomography system, comparison between the reconstruction methods of computed tomography and examples of the measured two-phase flow data which was taken in the 7 rod bundle with a gap between rods of 1.0 mm. (author)
Prediction of temperature distribution in a fast reactor spent fuel bundle
International Nuclear Information System (INIS)
A simple mathematical model is described for predicting temperature distribution in a spent fuel bundle. The model takes into account γ-ray leakage, radiant and conductive heat transports between the various fuel pins arranged in a triangular array and enclosed in a hexagonal shaped tube containing gaseous medium. With the geometry of the fuel bundle the configuration factors between various fuel pins can be calculated. The configuration factors along with the heat generation rates, net γ-ray leakage, surface emissivity, conductivity of the enclosed medium and the temperature of the hexagonal tube can be used to estimate the temperature distribution with the help of the computer code TICOFUSA developed on the basis of this model. (author)
An Approximate Proximal Bundle Method to Minimize a Class of Maximum Eigenvalue Functions
Directory of Open Access Journals (Sweden)
Wei Wang
2014-01-01
Full Text Available We present an approximate nonsmooth algorithm to solve a minimization problem, in which the objective function is the sum of a maximum eigenvalue function of matrices and a convex function. The essential idea to solve the optimization problem in this paper is similar to the thought of proximal bundle method, but the difference is that we choose approximate subgradient and function value to construct approximate cutting-plane model to solve the above mentioned problem. An important advantage of the approximate cutting-plane model for objective function is that it is more stable than cutting-plane model. In addition, the approximate proximal bundle method algorithm can be given. Furthermore, the sequences generated by the algorithm converge to the optimal solution of the original problem.
Welding problems in the construction of tube bundles for heat exchangers
International Nuclear Information System (INIS)
A description is given of gas tungsten-arc welding equipment to be used in welding heat exchangers for uranium hexafluoride. The basic requirements for the construction of tube bundles for special applications are discussed. Detailed consideration is given to programme control, the programme module and the torch head. The application to the welding of carbon steel tubes to carbon steel tubesheet is described, including the main welding parameters chosen, together with the results of nondestructive tests. (U.K.)
Asongu, Simplice; Nwachukwu, Jacinta
2015-01-01
We assess drivers of FDI in a panel of BRICS and MINT countries for the period 2001-2011. We bundle and unbundle governance determinants using a battery of contemporary and non-contemporary estimation techniques. The following findings are established. First, for both contemporary and non-contemporary specifications, while determinants for gross FDI are significant, they are not for net FDI. Second, for contemporary specifications, the significance of the governance dynamics is as follows in...
Comparison of heat transfer efficiency between heat pipe and tube bundles heat exchanger
Wu Zhao-Chun; Zhu Xiang-Ping
2015-01-01
A comparison of heat transfer efficiency between the heat pipe and tube bundles heat exchanger is made based on heat transfer principle and the analysis of thermal characteristics. This paper argues that although heat pipe has the feature of high axial thermal conductivity, to those cases where this special function of heat transfer is unnecessary, heat pipe exchanger is not a high efficient heat exchanger when it is just used as a conventional heat exchang...
International Nuclear Information System (INIS)
The demand for an accurate inservice inspection method for ferritic LMFBR steam generator tube bundles resulted in a fast and automatic operating system based upon ultrasonics, which appears suitable for nearly all kinds of heat exchangers. (author)
A model for the anisotropic response of fibrous soft tissues using six discrete fibre bundles
Flynn, Cormac
2011-06-30
The development of constitutive models of fibrous soft-tissues is a challenging problem. Many consider the tissue to be a collection of fibres with a continuous distribution function representing their orientations. A discrete fibre model is presented consisting of six weighted fibre-bundles. Each bundle is oriented such that it passes through opposing vertices of a regular icosahedron. A novel aspect is the use of simple analytical distribution functions to simulate undulated collagen fibres. This approach yields closed-form analytical expressions for the strain energy of the collagen fibre-bundle that avoids the sometimes costly numerical integration of some statistical distribution functions. The elastin fibres are characterized by a modified neo-Hookean type strain energy function which does not allow for fibre compression. The model accurately simulates biaxial stretching of rabbit-skin (error-of-fit 8.7), uniaxial stretching of pig-skin (error-of-fit 7.6), equibiaxial loading of aortic valve cusp (error-of-fit 0.8), and simple shear of rat septal myocardium (error-of-fit 8.9). It compares favourably with previous soft-tissue models and alternative methods of representing undulated collagen fibres. Predicted collagen fibre stiffnesses range from 8.0thinspaceMPa to 930MPa. Elastin fibre stiffnesses range from 2.0 kPa to 154.4 kPa. © 2011 John Wiley & Sons, Ltd.
Heat transfer profiles of a vertical, bare, 7-element bundle cooled with supercritical Freon-12
International Nuclear Information System (INIS)
Experimental data on SuperCritical-Water (SCW) cooled bundles are very limited. However, SuperCritical Water-cooled nuclear Reactor (SCWRs) designs cannot be optimized without such data. A set of experimental data obtained in Freon-12 (modeling fluid) cooled vertical bare bundle at the Institute of Physics and Power Engineering (IPPE, Obninsk, Russia) was analyzed. The existence of three distinct regimes for forced convention with supercritical fluids was experienced. (1) Normal heat transfer; (2) Deteriorated heat transfer, characterized by higher than expected temperatures; and (3) Enhanced heat transfer, characterized by lower than expected temperatures. This work compares the heat transfer coefficient of the experiments to predictions based upon current correlations for heat transfer in super critical fluids where the 1-D correlations are based upon tube data under supercritical water conditions. (author)
International Nuclear Information System (INIS)
The objective of this thesis is to study the ability of model reduction for investigations of flow-induced vibrations in heat exchangers tube bundle systems.These mechanisms are a cause of major concern because heat exchangers are key elements of nuclear power plants and on-board stoke-holds.In a first part, we give a recall on heat exchangers functioning and on vibratory problems to which they are prone. Then, complete calculations leaded with the CFD numerical code Code-Saturne are carried out, first for the flow around a single circular cylinder (fixed then elastically mounted) and then for the case of a tube bundle system submitted to cross-flow. Reduced-order method POD is applied to the flow resolution with fixed structures. The obtained results show the efficiency of this technique for such configurations, using stabilization methods for the dynamical system resolution in the tube-bundle case. Multiphase-POD, which is a method enabling the adaptation of POD to fluid-structure interactions, is applied. Large displacements of a single cylinder elastically mounted under cross-flow, corresponding to the lock-in phenomenon,are well reproduced with this reduction technique. In the same way, large displacements of a confined moving tube in a bundle are shown to be faithfully reconstructed.Finally, the use of model reduction is extended to parametric studies. First, we propose to use the method which consists in projecting Navier-Stokes equations for several values of the Reynolds number on to a unique POD basis. The results obtained confirm the fact that POD predictability is limited to a range of parameter values. Then, a basis interpolation method, constructed using Grassmann manifolds and allowing the construction of a POD basis from other pre-calculated basis, is applied to basic cases. (author)
[Johannes de Laet and his vision of the New World].
Vannini de Gerulewicz, M
1992-06-01
Highlighting the contribution of Johannes De Laet (1582-1649), naturalist, historian, researcher, to the knowledge of the New World history and geography, as well as its inhabitants, flora and fauna. Laet published his huge New World or Description of the Occidental Indies in Dutch (1625), Latin (1633) and French (1640). The first Spanish edition appeared in 1988 in Venezuela, edited by the author of this work. PMID:11636366
Conservation of Hydrophobic and Hydrophilic Residues in Four-Helix Bundle
Institute of Scientific and Technical Information of China (English)
秦猛; 王骏; 王炜
2003-01-01
The conservation of the hydrophobic and the hydrophilic residue sites obtained from 1000 designed sequences with the Z-score method for a four-helix bundle has been studied. The folding dynamic and thermodynamic features of the designed sequences and their different mutations are also studied. It is found that this conservation is related to the stability and the fast folding of the model proteins. Our results are consistent with the experimental results.
Knowledge-based Bundling of Smart Products on a Mobile Recommendation Agent
Kowatsch, Tobias; Maass, Wolfgang; Filler, Andreas; Janzen, Sabine
2008-01-01
Mobile technologies have the potential to change not only brick-and-mortar stores but also the way, how customers interact with physical products. They enable operational agility by means of improved availability and quality of information required by customers for in-store purchase decisions. In this paper, we show how an in-store bundling scenario can be supported by semantically enriched products (denoted as smart products) that provide dynamic product information through the use of mobile...
Gas‐Phase Velocity Estimation in a Tube Bundle by means of Wire‐Mesh Sensors
Vigo Hernández, Carlos
2013-01-01
Understanding of flow structure and hydrodynamics in tube bundles is crucial to develop and safely operate Steam Generators in Nuclear Power Plants. During normal operation, the Steam Generator contains a two‐phase water‐steam mixture at high pressure and saturated temperature (namely 60atm and 275°C). However, in case of tube rupture, completely new conditions arise. The TRISTAN project aims to investigate a simplified model of this scenario using a twophase air‐water flow at ambient p...
Quantum principal bundles and corresponding gauge theories
Durdevic, M
1995-01-01
A generalization of classical gauge theory is presented, in the framework of a noncommutative-geometric formalism of quantum principal bundles over smooth manifolds. Quantum counterparts of classical gauge bundles, and classical gauge transformations, are introduced and investigated. A natural differential calculus on quantum gauge bundles is constructed and analyzed. Kinematical and dynamical properties of corresponding gauge theories are discussed.
Thermal-hydraulic analysis of three-dimensional natural convection in a vertical rod bundle
International Nuclear Information System (INIS)
Numerical analyses have been conducted in boundary-fitted coordinates on the problem of three-dimensional natural convection in a vertical rod bundle that consists of a group of seven heated rods and a cold hexagonal enclosure surrounding them. Flow patterns and temperature distributions are obtained for Rayleigh numbers up to 107 with the aspect ratio of vertical to horizontal dimensions being set at the value of unity. Three Rayleigh number regions of different modes of heat transfer, i.e., pseudo-conduction, transitional convection and boundary layer regions, are discussed. The flow structures and the effect of natural convection on local and overall heat transfer rates are presented. It is found that the rods each tend to assume nearly the same average heat flux rate (in the case of isothermal conditions) as the Rayleigh number is increased. The results obtained enhance the basic understanding of buoyancy-induced fluid flow and heat transfer in rod bundles, and in particular the differences that are obtained when different boundary conditions are imposed on the inner cylindrical rods. Natural convection in an enclosed space consisting of a hot vertical rod bundle placed in a cold enclosure has potential applications including storage of heat-generating spent fuel assemblies, and heat removal of a nuclear fuel-pin configuration in a light-water reactor in situations of emergency
New Catalytic Proportions for Syntheses of SWNT Bundles (Ropes) and Its Characterization
Institute of Scientific and Technical Information of China (English)
DAI Tong; DAI Jian-feng
2006-01-01
The single-walled carbon nanotube(SWNT) bundles and ropes have been prepared by using the anode arc discharge plasma to evaporate the graphite rods which contain Fe,Co and Ni powders as catalyst in He atmosphere. Many purifying methods are used for the products. It indicates that the synthesis of SWNTs has been greatly affected by the preparation parameters of catalyzer,the buffer gas and its pressure,the arc current intensity,etc. The optimal condition for preparing SWNTs in our case has been proposed. The forming mechanism of the SWNTs bundles and ropes is also studied qualitatively. The evaporated single graphite sheet tends to reduce its active energy.
Development of a position sensor based on a four quadrant structured optic fiber bundle
International Nuclear Information System (INIS)
This article reports on the development of a new kind of 2D displacement sensor based on an optic fiber bundle whose fiber arrangement has been customized to provide an input sensitive surface with four quadrants. The fibers of each quadrant are regrouped to form four output arms. The aim is to reach behavior similar to that of a quad cell photodiode when illuminated by a laser spot. In this paper, we present the motivations for developing such a sensor and its design. Prior to the fabrication of a first prototype, the optic fiber bundle has been modelled and compared to a quad cell photodiode. It has an active surface which is 10 mm in diameter and which comprises 40 000 fibers of 50 µm core diameter. For this experimental test, a specific electronic conditioning circuit has been developed to process the signals. From both modelled and experimental results, fiber optic bundle and quad cell photodiode behavior has proved to be very similar, provided that the number of fibers is sufficient to achieve a statistical effect on the detected displacement, i.e. the laser spot diameter is rightly chosen as a function of the fiber diameter. For the use of the bundle as position sensor, a laser spot size of 5 mm has been fixed to achieve a good compromise between sensitivity and displacement range. With this spot size, sensitivity and displacement range have been experimentally evaluated to 2 mV µm−1 and 3.8 mm respectively with a corresponding displacement resolution of 5 nm in the best case. (paper)
Subchannel and Computational Fluid Dynamic Analyses of a Model Pin Bundle
Energy Technology Data Exchange (ETDEWEB)
Gairola, A.; Arif, M.; Suh, K. Y. [Seoul National Univ., Seoul (Korea, Republic of)
2014-05-15
The current study showed that the simplistic approach of subchannel analysis code MATRA was not good in capturing the physical behavior of the coolant inside the rod bundle. With the incorporation of more detailed geometry of the grid spacer in the CFX code it was possible to approach the experimental values. However, it is vital to incorporate more advanced turbulence mixing models to more realistically simulate behavior of the liquid metal coolant inside the model pin bundle in parallel with the incorporation of the bottom and top grid structures. In the framework of the 11{sup th} international meeting of International Association for Hydraulic Research and Engineering (IAHR) working group on the advanced reactor thermal hydraulics a standard problem was conducted. The quintessence of the problem was to check on the hydraulics and heat transfer in a novel pin bundle with different pitch to rod diameter ratio and heat flux cooled by liquid metal. The standard problem stems from the field of nuclear safety research with the idea of validating and checking the performances of computer codes against the experimental results. Comprehensive checks between the two will succor in improving the dependability and exactness of the codes used for accident simulations.
Sperm bundles in the seminal vesicles of sexually mature Lasius ant males.
Burnett, William E; Heinze, Jürgen
2014-01-01
In many insects, sperm cells are produced in bundles with their heads being held together by a glycoprotein matrix secreted by a cyst cell. Mature sperm cells in the seminal vesicles are usually free, but in sawflies and several other insects, such structures (spermatodesmata) remain intact and sperm cells may be ejaculated as bundles. Here we report the occurrence of spermatodesmata in mature males of the ant Lasius pallitarsis. Microscopic investigations of the abdominal contents of males immediately prior to their nuptial flights showed that the anterior ends of numerous sperm cells were embedded in an oval-shaped 20 by 30 micrometer extracellular fibrous cap. Individual sperm ranged in length from 55 to 75 micrometers with an average overall length of 65 micrometers. The bulb-shaped heads of the sperm were relatively small, only about 1.5 micrometers in length and about 1.1 micrometers in diameter. The diameter of the sperm tails was approximately 1 micrometer. Observations of live preparations of the spermatodesmata showed increasingly active undulating wave-like movement of the sperm tails as the slide preparations aged. This appears to be the first case of sperm bundles being present in the seminal vesicles of mature ant males--males that are immediately poised to complete their nuptial mating flight.
Sperm bundles in the seminal vesicles of sexually mature Lasius ant males.
Directory of Open Access Journals (Sweden)
William E Burnett
Full Text Available In many insects, sperm cells are produced in bundles with their heads being held together by a glycoprotein matrix secreted by a cyst cell. Mature sperm cells in the seminal vesicles are usually free, but in sawflies and several other insects, such structures (spermatodesmata remain intact and sperm cells may be ejaculated as bundles. Here we report the occurrence of spermatodesmata in mature males of the ant Lasius pallitarsis. Microscopic investigations of the abdominal contents of males immediately prior to their nuptial flights showed that the anterior ends of numerous sperm cells were embedded in an oval-shaped 20 by 30 micrometer extracellular fibrous cap. Individual sperm ranged in length from 55 to 75 micrometers with an average overall length of 65 micrometers. The bulb-shaped heads of the sperm were relatively small, only about 1.5 micrometers in length and about 1.1 micrometers in diameter. The diameter of the sperm tails was approximately 1 micrometer. Observations of live preparations of the spermatodesmata showed increasingly active undulating wave-like movement of the sperm tails as the slide preparations aged. This appears to be the first case of sperm bundles being present in the seminal vesicles of mature ant males--males that are immediately poised to complete their nuptial mating flight.
[J.E. GILIBERT--HIS LIFE AND WORK IN THE LIGHT OF A CORRESPONDENCE AND TESTIMONIES OF HIS TIME].
Daszkiewicz, Piotr
2015-01-01
Jean-Emmanuel Gilibert (1741-1814) has been the subject of few biographical works. This paper presents the results of research from unpublished documents, unknown by historians until now. The information, publishedin old sources as in Gilibert autobiographical sketches or in catalogues of natural history papers auctions, is critically analyzed here. We also tried to establish a list of documents from those cited by Gilibert biographers, but lost today. The author both presents and comments letters to Antoine-Laurent de Jussieu (1748-1836) and André Thouin (1747-1824), as well as a letter to an unknown receiver, in the autograph's collection of Gustave Thuret (1747-1824) and Eduard Bornet (1828-1911)--which is conserved in the collection of the National Museum of Natural History in Paris. Precious information about Gilibert and his stay in Lithuania was found in the letters of Antoine Gouan (1733-1821) to Philippe-Isidore Picot de Lapeyrouse (1744-1818). Research were also conducted in the Museum's herbarium in order to find Gilibert's specimens from Lithuania as well as to discover more information about the naturalist himself. The documents of Jean Hermann (1738-1800) linked with Gilibert were found in Strasbourg's National and University Libraries and in the Municipal Archives; a letter from Gilibert to Antoine-Laurent de Jussieu was also discovered in this collection. Some new and interesting data came from a register of Hermann's natural history cabinet visitors Some additional information about Gilibert's life and work was obtained as a result of the analysis of manuscripts conserved in the National Academy of Medicine in Paris, more specifically in Gilibert's correspondences from Lithuania and Lyon about illnesses and epidemics. The information obtained allowed a better knowledge of the history of Gilibert floristic works in Lithuania, his zoological research, his practice of medicine and his study of different pathologies, his way of collecting and the
Sectional pipeline bundles. Design, fabrication and testing of a subsea pipeline connection system
Energy Technology Data Exchange (ETDEWEB)
NONE
1999-08-01
The tests of the prototype system indicated that the system is applicable for connecting pipeline bundle sections. The overall performance of the system is therefore concluded to be satisfactory. Some modifications are required though, for improving the reliability of the system to the level required for offshore North Sea application. The tests showed that connection of the pipeline bundle sections can be performed for alignment tolerances larger than those expected during a typical subsea installation. Pull-in of bundle end sections can be performed with pull-in wires deployed from surface. The offshore tests showed that handling of wires must be done with great care to avoid possibility for wire entanglement, especially if a fully diverless system is to be used. The flowline connection tool was found to be suitable for final alignment of the individual spool ends. It was demonstrated that face to face contact between the hub faces in the connector was obtained after tie-in. Pressure tests showed that the connector could be sealed by the tie-in force applied by the connection tool tie-in system. However, the standard connector clamp which was used, was found to be insuficient for maintaining the connector effectively sealed after removal of the pull-in force applied by the connection tool. Based on the results proposals for improvements of the system are included. Improvements are applicable to the current system for connection of bundle sections or for tie-in operations, relating to conventional pipelines. The improvements also includes a strong connection clamp suitable for subsea use. The connection clamp will replace the standard clamp devise used in this project. (au) EFP-96. 41 refs.
Effect of Entry/Exit Length on Flow Distribution in the Test Bundle
Energy Technology Data Exchange (ETDEWEB)
Jang, Byeong Il; Jang, Beom Jun; Kim, Hong Ju; Kim, Kanghoon; Nahm, Kee Yil; Park, Sang Weon [KEPCO Nuclear Fuel, Daejeon (Korea, Republic of)
2014-05-15
In data analysis, the geometric information within the heated section of the rod bundle is important because the CHF occurs in the heated section. To ensure a constant geometry and to prevent adverse flow effects, it is required to extend the same geometry beyond the heated section of rod bundle geometry. Regarding to evaluate the validity of inlet boundary condition of subchannel analysis code, the effect of the entry and exit length on the flow distribution is evaluated under the various inlet flow conditions which could be produced without flow distributor or strainer. To evaluate the validation of the inlet and outlet boundary conditions used in the subchannel analysis code, a study on the effect of the entry and exit length on the flow distribution is conducted. Even though the non-uniform flow is entered inside the test bundle, the flow gets more saturated by the simple supports and frictions. Through the code calculation under various flow conditions, it is concluded that the flow is to be fully developed flow over about 40∼80 inches of the entry length. If the exit length is about 30∼40 inches, the effect of the exit pressure can be negligible. The entry and exit length in this paper is calculated based on only rod bundles and simple supports. By installing the flow distributors or strainer, these lengths can get shorter and the flow difference between the subchannels become smaller. This study could be very useful in order to confirm the validation of the boundary conditions used in the subchannel analysis code.
DESIGN OF WIRE-WRAPPED ROD BUNDLE MATCHED INDEX-OF-REFRACTION EXPERIMENTS
Energy Technology Data Exchange (ETDEWEB)
Hugh McIlroy; Hongbin Zhang; Kurt Hamman
2008-05-01
Experiments will be conducted in the Idaho National Laboratory (INL) Matched Index-of-Refraction (MIR) Flow Facility [1] to characterize the three-dimensional velocity and turbulence fields in a wire-wrapped rod bundle typically employed in liquid-metal cooled fast reactors and to provide benchmark data for computer code validation. Sodium cooled fast reactors are under consideration for use in the U.S. Department of Energy (DOE) Global Nuclear Energy Partnership (GNEP) program. The experiment model will be constructed of quartz components and the working fluid will be mineral oil. Accurate temperature control (to within 0.05 oC) matches the index-of-refraction of mineral oil with that of quartz and renders the model transparent to the wavelength of laser light employed for optical measurements. The model will be a scaled 7-pin rod bundle enclosed in a hexagonal canister. Flow field measurements will be obtained with a LaVision 3-D particle image velocimeter (PIV) and complimented by near-wall velocity measurements obtained from a 2-D laser Doppler velocimeter (LDV). These measurements will be used as benchmark data for computational fluid dynamics (CFD) validation. The rod bundle model dimensions will be scaled up from the typical dimensions of a fast reactor fuel assembly to provide the maximum Reynolds number achievable in the MIR flow loop. A range of flows from laminar to fully-turbulent will be available with a maximum Reynolds number, based on bundle hydraulic diameter, of approximately 22,000. The fuel pins will be simulated by 85 mm diameter quartz tubes (closed on the inlet ends) and the wire-wrap will be simulated by 25 mm diameter quartz rods. The canister walls will be constructed from quartz plates. The model will be approximately 2.13 m in length. Bundle pressure losses will also be measured and the data recorded for code comparisons. The experiment design and preliminary CFD calculations, which will be used to provide qualitative hydrodynamic
Cetera, Maureen; Ramirez-San Juan, Guillermina R; Oakes, Patrick W; Lewellyn, Lindsay; Fairchild, Michael J; Tanentzapf, Guy; Gardel, Margaret L; Horne-Badovinac, Sally
2014-01-01
Tissues use numerous mechanisms to change shape during development. The Drosophila egg chamber is an organ-like structure that elongates to form an elliptical egg. During elongation the follicular epithelial cells undergo a collective migration that causes the egg chamber to rotate within its surrounding basement membrane. Rotation coincides with the formation of a 'molecular corset', in which actin bundles in the epithelium and fibrils in the basement membrane are all aligned perpendicular to the elongation axis. Here we show that rotation plays a critical role in building the actin-based component of the corset. Rotation begins shortly after egg chamber formation and requires lamellipodial protrusions at each follicle cell's leading edge. During early stages, rotation is necessary for tissue-level actin bundle alignment, but it becomes dispensable after the basement membrane is polarized. This work highlights how collective cell migration can be used to build a polarized tissue organization for organ morphogenesis.
CFD Turbulence Study of PWR Spacer-Grids in a Rod Bundle
Directory of Open Access Journals (Sweden)
C. Peña-Monferrer
2014-01-01
the flow dynamics and heat transfer phenomena along the fuel rods. This work presents the analysis of the turbulence effects of a split-type and swirl-type spacer-grid geometries on single phase in a PWR (pressurized water reactor rod bundle. Various computational fluid dynamics (CFD calculations have been performed and the results validated with the experiments of the OECD/NEA-KAERI rod bundle CFD blind benchmark exercise on turbulent mixing in a rod bundle with spacers at the MATiS-H facility. Simulation of turbulent phenomena downstream of the spacer-grid presents high complexity issues; a wide range of length scales are present in the domain increasing the difficulty of defining in detail the transient nature of turbulent flow with ordinary turbulence models. This paper contains a complete description of the procedure to obtain a validated CFD model for the simulation of the spacer-grids. Calculations were performed with the commercial code ANSYS CFX using large eddy simulation (LES turbulence model and the CFD modeling procedure validated by comparison with measurements to determine their suitability in the prediction of the turbulence phenomena.
Song, Youngsup; Lee, Jae-Ik; Pyo, Soonjae; Eun, Youngkee; Choi, Jungwook; Kim, Jongbaeg
2016-05-01
A novel carbon nanotube (CNT)-based flexible strain sensor with the highest gauge factor of 4739 is presented. CNT-to-CNT contacts are fabricated on a pair of silicon electrodes fixed on a PDMS specimen for both flexibility and electrical connection. The strain is detected by the resistance change between facing CNT bundles. The proposed approach could be applied for diverse applications with a high gauge factor.
CFD Verification of 5x5 Rod Bundle with Mixing Vane Spacer Grids
Energy Technology Data Exchange (ETDEWEB)
Park, Sungkew; Jang, Hyungwook; Lim, Jongseon; Park, Eungjun; Nahm, Keeyil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2014-05-15
Results of the CHF test are used for determining the CHF correlation, which is used to evaluate the thermal margin in the reactor core. Computational fluid dynamics (CFD) has been used to save the time and cost for experimental tests, components design and complicated phenomena in all industries including the reactor coolant system. L. D. Smith et al. applied the CFD methodology in a 5x5 rod bundle with the mixing vane spacer grid using the renormalization group (RNG) k-epsilon model. This CFD model agreed reasonably well with the test data. M. E. Conner et al. conducted experiments to validate the CFD methodology for the single-phase flow conditions in PWR fuel assemblies. In this validation case, the CFD code predicted very similar flow field structures as the test data. In this study, a CFD simulation under single-phase flow condition was conducted for one specific condition in a thermal mixing flow test of 5x5 rod bundle with some mixing vane spacer grids. In this study, a CFD simulation under a single-phase flow condition was conducted for one specific condition in a thermal mixing flow test of 5x5 rod bundle with the mixing vane spacer grids to verify the applicability of the CFD model for predicting the outlet temperature distribution. FLUENT 14.5 Version was used in this CFD analysis. For the successful prediction of the wall bounded turbulent flows, the y+ with 3 prism layers was determined within 5. At this time, k-epsilon standard turbulence model was used. The temperature distribution of CFD for each sub-channel at the outlet region of test bundle showed the difference approximately within 1.1% and 0.2% while comparing to that of test and sub-channel analysis code, respectively.
CFD Verification of 5x5 Rod Bundle with Mixing Vane Spacer Grids
International Nuclear Information System (INIS)
Results of the CHF test are used for determining the CHF correlation, which is used to evaluate the thermal margin in the reactor core. Computational fluid dynamics (CFD) has been used to save the time and cost for experimental tests, components design and complicated phenomena in all industries including the reactor coolant system. L. D. Smith et al. applied the CFD methodology in a 5x5 rod bundle with the mixing vane spacer grid using the renormalization group (RNG) k-epsilon model. This CFD model agreed reasonably well with the test data. M. E. Conner et al. conducted experiments to validate the CFD methodology for the single-phase flow conditions in PWR fuel assemblies. In this validation case, the CFD code predicted very similar flow field structures as the test data. In this study, a CFD simulation under single-phase flow condition was conducted for one specific condition in a thermal mixing flow test of 5x5 rod bundle with some mixing vane spacer grids. In this study, a CFD simulation under a single-phase flow condition was conducted for one specific condition in a thermal mixing flow test of 5x5 rod bundle with the mixing vane spacer grids to verify the applicability of the CFD model for predicting the outlet temperature distribution. FLUENT 14.5 Version was used in this CFD analysis. For the successful prediction of the wall bounded turbulent flows, the y+ with 3 prism layers was determined within 5. At this time, k-epsilon standard turbulence model was used. The temperature distribution of CFD for each sub-channel at the outlet region of test bundle showed the difference approximately within 1.1% and 0.2% while comparing to that of test and sub-channel analysis code, respectively
Kalisz, Sylwester; Pronobis, Marek
2005-09-01
In the paper the results of comparative investigations on heat transfer performance of boiler convective bundle and its additional surface, i.e. membrane water wall are presented. For this purpose the non-uniform flow field was modelled in an isothermal test stand operated in self-modeling mode. Then the heat transfer characteristics of such arrangement were estimated by means of naphthalene heat/mass transfer analogy technique. The bundle samples in the shape of round bars (rods) were cast with naphthalene and placed in 27 locations in the bundle while water-wall-modeling samples were coated with naphthalene by painting. Both types of samples were exposed to cold air flow. The results were then compared to the mean heat transfer performance of the same bundle exposed to uniform flow field. The differences of approximately 10% were noticed. Moreover, the heat transfer coefficients for additional surface were even three times lower than those of the bundle. In view of results obtained in the work, the commonly made assumption of equality of heat transfer coefficients for both the bundle and its additional surface may lead to certain errors in heat transfer calculations and discrepancies between the calculated values of heating surfaces area and later operational needs of steam generator.
Post-irradiation examination of CANDU fuel bundles fuelled with (Th, Pu)O2
International Nuclear Information System (INIS)
AECL has extensive experience with thoria-based fuel irradiations as part of an ongoing R&D program on thorium within the Advanced Fuel Cycles Program. The BDL-422 experiment was one component of the thorium program that involved the fabrication and irradiation testing of six Bruce-type bundles fuelled with (Th, Pu)O2 pellets. The fuel was manufactured in the Recycle Fuel Fabrication Laboratories (RFFL) at Chalk River allowing AECL to gain valuable experience in fabrication and handling of thoria fuel. The fuel pellets contained 86.05 wt. % Th and 1.53 wt. % Pu in (Th, Pu)O2. The objectives of the BDL-422 experiment were to demonstrate the ability of 37-element geometry (Th, Pu)O2 fuel bundles to operate to high burnups up to 1000 MWh/kgHE (42 MWd/kgHE), and to examine the (Th, Pu)O2 fuel performance. This paper describes the post-irradiation examination (PIE) results of BDL-422 fuel bundles irradiated to burnups up to 856 MWh/kgHE (36 MWd/kgHE), with power ratings ranging from 52 to 67 kW/m. PIE results for the high burnup bundles (>1000 MWh/kgHE) are being analyzed and will be reported at a later date. The (Th, Pu)O2 fuel performance characteristics were superior to UO2 fuel irradiated under similar conditions. Minimal grain growth was observed and was accompanied by benign fission gas release and sheath strain. Other fuel performance parameters, such as sheath oxidation and hydrogen distribution, are also discussed. (author)
A Piecewise Hysteresis Model for a Damper of HIS System
Directory of Open Access Journals (Sweden)
Kaidong Tian
2016-01-01
Full Text Available A damper of the hydraulically interconnected suspension (HIS system, as a quarter HIS, is prototyped and its damping characteristic is tested to characterize the damping property. The force-velocity characteristic of the prototype is analyzed based on a set of testing results and accordingly a piecewise hysteresis model for the damper is proposed. The proposed equivalent parametric model consists of two parts: hysteresis model in low speed region and saturation model in high speed region which are used to describe the hysteresis phenomenon in low speed and nonhysteresis phenomenon in high speed, respectively. The parameters of the model are identified based on genetic algorithm by setting the constraints of parameters according to their physical significances and the corresponding testing results. The advantages of the model are highlighted by comparing to the nonhysteresis model and the permanent hysteresis model. The numerical simulation results are compared with the testing results to validate the accuracy and effectiveness of the proposed model. Finally, to further verify the proposed model’s wide applicability under different excitation conditions, its results are compared to the testing results in three-dimensional space. The research in this paper is significant for the dynamic analysis of the HIS vehicle.
The Chern Character of Certain Infinite Rank Bundles arising in Gauge Theory
Mickelsson, Jouko
2012-01-01
A cocycle $\\Omega: P \\times G \\to H$ taking values in a Lie group $H$ for a free right action of $G$ on $P$ defines a principal bundle $Q$ with the structure group $H$ over $P/G.$ The Chern character of a vector bundle associated to $Q$ defines then characteristic classes on $X.$ This observation becomes useful in the case of infinite dimensional groups. It typically happens that a representation of $G$ is not given by linear operators which differ from the indentity by a trace-class operator. For this reason the Chern character of a vector bundle associated to the principal fibration $P \\to P/G$ is ill-defined. But it may happen that the Lie algebra representations of the group $H$ are given in terms of trace-class operators and therefore the Chern character is well-defined; this observation is useful especially if the map $g\\mapsto \\Omega(p;g)$ is a homotopy equivalence on the image for any $p\\in P.$ We apply this method to the case $P= \\Cal A,$ the space of gauge connections in a finite-dimensional vector ...
Numerical Simulation for Frictional Loss and Local Loss of a 5*5 SMART Rod Bundle
Energy Technology Data Exchange (ETDEWEB)
Park, Jong-Pil; Kim, Seong Jin; Kwon, Hyuk; Seo, Kyong-Won; Hwang, Dae-Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2014-10-15
The results showed good agreement with experimental data and/or reasonable values. However, these results were dependent on computational meshes and turbulence models and it still remains important issues in CFD analysis. The aim of present work is to assess the pressure drop in a 5*5 SMART rod bundle using 3D CFD code with various computational meshes and turbulence models. In the present work, 3D CFD code was utilized to investigate pressure drop in a SMART 5*5 rod bundle. The predicted pressure drop was strongly dependent with computational meshes and turbulence models. Based on CFD results in this study, least five of six meshes within the subchannel gap are required to get reliable result which is insensitive to the number of meshes. The friction factor predicted by k - ε model is good agreement with McAdams's correlation while SST model overestimate McAdams's correlation. However, it is difficult to judge performance of turbulence model because of lock of experimental data for a 5*5 SMART bare rod bundle. For nominal condition (Re-194,000) of SMART, SST model predict k-factor of MV and IFM grid as 1.304 and 0.748, respectively. This value is reasonable as compared with designed k-factor, 1.320 and 0.78.
Walbot, V
1977-07-01
The first method for the direct separation of mesophyll and bundle sheath chloroplasts from whole tissue homogenates of a C(4) plant is described. Centrifugation of mixed chloroplast preparations from Panicum maximum through low viscosity silica sol gradients effectively separates large, starch-containing chloroplasts from smaller plastids. The large chloroplasts are judged to be bundle sheath chloroplasts on the basis of microscopic appearance, the presence of starch grains, the protein complement displayed on sodium dodecyl sulfate acrylamide gels, and the exclusive localization of ribulose bisphosphate carboxylase activity in these plastids. As a measure of intactness both the large (bundle sheath) and small (mesophyll) chloroplasts contain glyceralde-hyde-3-phosphate NADP-dependent dehydrogenase activity that is greatly enhanced by plastid lysis and both chloroplast preparations are impermeable to deoxyribonuclease. Chloroplast enzyme activities are inhibited by silica sol due to the Mg(2+) chelating activity of this reagent. However, well washed chloroplasts separated on silica gradients had enzyme activities similar to reported values in which silica sol gradients were not used. PMID:16660019