Sample records for lagrangian subzonal masses
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Caramana, E.J.; Shashkov, M.J.
1997-12-31
The bane of Lagrangian hydrodynamics calculations is premature breakdown of the grid topology that results in severe degradation of accuracy and run termination often long before the assumption of Lagrangian zonal mass ceased to be valid. At short spatial grid scales this is usually referred to by the terms hourglass mode or keystone motion associated in particular with underconstrained grids such as quadrilaterals and hexahedrons in two and three dimensions, respectively. At longer spatial scales relative to the grid spacing there is what is referred to ubiquitously as spurious vorticity, or the long-thin zone problem. In both cases the resultmore » is anomalous grid distortion and tangling that has nothing to do with the actual solution, as would be the case for turbulent flow. In this work the authors show how such motions can be eliminated by the proper use of subzonal Lagrangian masses, and associated densities and pressures. These subzonal masses arise in a natural way from the fact that they require the mass associated with the nodal grid point to be constant in time. This is addition to the usual assumption of constant, Lagrangian zonal mass in staggered grid hydrodynamics scheme. The authors show that with proper discretization of subzonal forces resulting from subzonal pressures, hourglass motion and spurious vorticity can be eliminated for a very large range of problems. Finally the authors are presenting results of calculations of many test problems.« less
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NASA Astrophysics Data System (ADS)
Kenamond, Mack; Bement, Matthew; Shashkov, Mikhail
2014-07-01
We present a new discretization for 2D arbitrary Lagrangian-Eulerian hydrodynamics in rz geometry (cylindrical coordinates) that is compatible, total energy conserving and symmetry preserving. In the first part of the paper, we describe the discretization of the basic Lagrangian hydrodynamics equations in axisymmetric 2D rz geometry on general polygonal meshes. It exactly preserves planar, cylindrical and spherical symmetry of the flow on meshes aligned with the flow. In particular, spherical symmetry is preserved on polar equiangular meshes. The discretization conserves total energy exactly up to machine round-off on any mesh. It has a consistent definition of kinetic energy in the zone that is exact for a velocity field with constant magnitude. The method for discretization of the Lagrangian equations is based on ideas presented in [2,3,7], where the authors use a special procedure to distribute zonal mass to corners of the zone (subzonal masses). The momentum equation is discretized in its “Cartesian” form with a special definition of “planar” masses (area-weighted). The principal contributions of this part of the paper are as follows: a definition of “planar” subzonal mass for nodes on the z axis (r=0) that does not require a special procedure for movement of these nodes; proof of conservation of the total energy; formulated for general polygonal meshes. We present numerical examples that demonstrate the robustness of the new method for Lagrangian equations on a variety of grids and test problems including polygonal meshes. In particular, we demonstrate the importance of conservation of total energy for correctly modeling shock waves. In the second part of the paper we describe the remapping stage of the arbitrary Lagrangian-Eulerian algorithm. The general idea is based on the following papers [25-28], where it was described for Cartesian coordinates. We describe a distribution-based algorithm for the definition of remapped subzonal densities and a
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Kucharik, M.; Scovazzi, Guglielmo; Shashkov, Mikhail Jurievich
Hourglassing is a well-known pathological numerical artifact affecting the robustness and accuracy of Lagrangian methods. There exist a large number of hourglass control/suppression strategies. In the community of the staggered compatible Lagrangian methods, the approach of sub-zonal pressure forces is among the most widely used. However, this approach is known to add numerical strength to the solution, which can cause potential problems in certain types of simulations, for instance in simulations of various instabilities. To avoid this complication, we have adapted the multi-scale residual-based stabilization typically used in the finite element approach for staggered compatible framework. In this study, wemore » describe two discretizations of the new approach and demonstrate their properties and compare with the method of sub-zonal pressure forces on selected numerical problems.« less
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Kucharik, M.; Scovazzi, Guglielmo; Shashkov, Mikhail Jurievich; ...
2017-10-28
Hourglassing is a well-known pathological numerical artifact affecting the robustness and accuracy of Lagrangian methods. There exist a large number of hourglass control/suppression strategies. In the community of the staggered compatible Lagrangian methods, the approach of sub-zonal pressure forces is among the most widely used. However, this approach is known to add numerical strength to the solution, which can cause potential problems in certain types of simulations, for instance in simulations of various instabilities. To avoid this complication, we have adapted the multi-scale residual-based stabilization typically used in the finite element approach for staggered compatible framework. In this study, wemore » describe two discretizations of the new approach and demonstrate their properties and compare with the method of sub-zonal pressure forces on selected numerical problems.« less
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2011-04-18
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2011-04-08
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2011-04-08
... and Expansion of Manufacturing Authority; Foreign-Trade Subzone 29F; Hitachi Automotive Systems Americas, Inc. (Automotive Components); Harrodsburg, KY Pursuant to its authority under the Foreign-Trade... on behalf of Hitachi Automotive Systems Americas, Inc. (Hitachi), operator of Subzone 29F at the...
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2011-12-05
... and Expansion of Manufacturing Authority; Foreign-Trade Subzone 124B; North American Shipbuilding, LLC (Shipbuilding); Larose, Houma, and Port Fourchon, Louisiana Pursuant to its authority under the Foreign-Trade... North American Shipbuilding, LLC (NAS), operator of Subzone 124B at the NAS shipbuilding facilities in...
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NASA Technical Reports Server (NTRS)
Methven, J.; Arnold, S. R.; Stohl, A.; Evans, M. J.; Avery, M.; Law, K.; Lewis, A. C.; Monks, P. S.; Parrish, D.; Reeves, C.;
2006-01-01
The International Consortium for Atmospheric Research on Transport and Transformation (ICARTT)-Lagrangian experiment was conceived with an aim to quantify the effects of photochemistry and mixing on the transformation of air masses in the free troposphere away from emissions. To this end attempts were made to intercept and sample air masses several times during their journey across the North Atlantic using four aircraft based in New Hampshire (USA), Faial (Azores) and Creil (France). This article begins by describing forecasts using two Lagrangian models that were used to direct the aircraft into target air masses. A novel technique is then used to identify Lagrangian matches between flight segments. Two independent searches are conducted: for Lagrangian model matches and for pairs of whole air samples with matching hydrocarbon fingerprints. The information is filtered further by searching for matching hydrocarbon samples that are linked by matching trajectories. The quality of these coincident matches is assessed using temperature, humidity and tracer observations. The technique pulls out five clear Lagrangian cases covering a variety of situations and these are examined in detail. The matching trajectories and hydrocarbon fingerprints are shown and the downwind minus upwind differences in tracers are discussed.
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On tide-induced Lagrangian residual current and residual transport: 1. Lagrangian residual current
Feng, Shizuo; Cheng, Ralph T.; Pangen, Xi
1986-01-01
Residual currents in tidal estuaries and coastal embayments have been recognized as fundamental factors which affect the long-term transport processes. It has been pointed out by previous studies that it is more relevant to use a Lagrangian mean velocity than an Eulerian mean velocity to determine the movements of water masses. Under weakly nonlinear approximation, the parameter k, which is the ratio of the net displacement of a labeled water mass in one tidal cycle to the tidal excursion, is assumed to be small. Solutions for tides, tidal current, and residual current have been considered for two-dimensional, barotropic estuaries and coastal seas. Particular attention has been paid to the distinction between the Lagrangian and Eulerian residual currents. When k is small, the first-order Lagrangian residual is shown to be the sum of the Eulerian residual current and the Stokes drift. The Lagrangian residual drift velocity or the second-order Lagrangian residual current has been shown to be dependent on the phase of tidal current. The Lagrangian drift velocity is induced by nonlinear interactions between tides, tidal currents, and the first-order residual currents, and it takes the form of an ellipse on a hodograph plane. Several examples are given to further demonstrate the unique properties of the Lagrangian residual current.
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2012-08-08
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2010-02-26
...); Apple Valley, MN Pursuant to its authority under the Foreign-Trade Zones Act of June 18, 1934, as... of Subzone 119B at the Uponor polyethylene tubing manufacturing and distribution facilities in Apple...
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A mass and momentum conserving unsplit semi-Lagrangian framework for simulating multiphase flows
DOE Office of Scientific and Technical Information (OSTI.GOV)
Owkes, Mark, E-mail: mark.owkes@montana.edu; Desjardins, Olivier
In this work, we present a computational methodology for convection and advection that handles discontinuities with second order accuracy and maintains conservation to machine precision. This method can transport a variety of discontinuous quantities and is used in the context of an incompressible gas–liquid flow to transport the phase interface, momentum, and scalars. The proposed method provides a modification to the three-dimensional, unsplit, second-order semi-Lagrangian flux method of Owkes & Desjardins (JCP, 2014). The modification adds a refined grid that provides consistent fluxes of mass and momentum defined on a staggered grid and discrete conservation of mass and momentum, evenmore » for flows with large density ratios. Additionally, the refined grid doubles the resolution of the interface without significantly increasing the computational cost over previous non-conservative schemes. This is possible due to a novel partitioning of the semi-Lagrangian fluxes into a small number of simplices. The proposed scheme is tested using canonical verification tests, rising bubbles, and an atomizing liquid jet.« less
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78 FR 79662 - Approval of Subzone Status; VF Jeanswear; Hackleburg, Alabama
Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-31
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-136-2013] Approval of Subzone Status; VF Jeanswear; Hackleburg, Alabama On September 19, 2013, the Executive Secretary of the Foreign-Trade Zones (FTZ) Board docketed an application submitted by the Huntsville- Madison County Airport Authority, grantee of FTZ 83, requesting subzone status...
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A new approach to enforce element-wise mass/species balance using the augmented Lagrangian method
NASA Astrophysics Data System (ADS)
Chang, J.; Nakshatrala, K.
2015-12-01
The least-squares finite element method (LSFEM) is one of many ways in which one can discretize and express a set of first ordered partial differential equations as a mixed formulation. However, the standard LSFEM is not locally conservative by design. The absence of this physical property can have serious implications in the numerical simulation of subsurface flow and transport. Two commonly employed ways to circumvent this issue is through the Lagrange multiplier method, which explicitly satisfies the element-wise divergence by introducing new unknowns, or through appending a penalty factor to the continuity constraint, which reduces the violation in the mass balance. However, these methodologies have some well-known drawbacks. Herein, we propose a new approach to improve the local balance of species/mass balance. The approach augments constraints to a least-square function by a novel mathematical construction of the local species/mass balance, which is different from the conventional ways. The resulting constrained optimization problem is solved using the augmented Lagrangian, which corrects the balance errors in an iterative fashion. The advantages of this methodology are that the problem size is not increased (thus preserving the symmetry and positive definite-ness) and that one need not provide an accurate guess for the initial penalty to reach a prescribed mass balance tolerance. We derive the least-squares weighting needed to ensure accurate solutions. We also demonstrate the robustness of the weighted LSFEM coupled with the augmented Lagrangian by solving large-scale heterogenous and variably saturated flow through porous media problems. The performance of the iterative solvers with respect to various user-defined augmented Lagrangian parameters will be documented.
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NASA Astrophysics Data System (ADS)
Methven, J.; Arnold, S. R.; Stohl, A.; Evans, M. J.; Avery, M.; Law, K.; Lewis, A. C.; Monks, P. S.; Parrish, D. D.; Reeves, C. E.; Schlager, H.; Atlas, E.; Blake, D. R.; Coe, H.; Crosier, J.; Flocke, F. M.; Holloway, J. S.; Hopkins, J. R.; McQuaid, J.; Purvis, R.; Rappenglück, B.; Singh, H. B.; Watson, N. M.; Whalley, L. K.; Williams, P. I.
2006-12-01
The ITCT-Lagrangian-2K4 (Intercontinental Transport and Chemical Transformation) experiment was conceived with an aim to quantify the effects of photochemistry and mixing on the transformation of air masses in the free troposphere away from emissions. To this end, attempts were made to intercept and sample air masses several times during their journey across the North Atlantic using four aircraft based in New Hampshire (USA), Faial (Azores) and Creil (France). This article begins by describing forecasts from two Lagrangian models that were used to direct the aircraft into target air masses. A novel technique then identifies Lagrangian matches between flight segments. Two independent searches are conducted: for Lagrangian model matches and for pairs of whole air samples with matching hydrocarbon fingerprints. The information is filtered further by searching for matching hydrocarbon samples that are linked by matching trajectories. The quality of these "coincident matches" is assessed using temperature, humidity and tracer observations. The technique pulls out five clear Lagrangian cases covering a variety of situations and these are examined in detail. The matching trajectories and hydrocarbon fingerprints are shown, and the downwind minus upwind differences in tracers are discussed.
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NASA Astrophysics Data System (ADS)
Tarshish, Nathaniel; Abernathey, Ryan; Dufour, Carolina; Frenger, Ivy; Griffies, Stephen
2017-04-01
Transient ocean mesoscale fluctuations play a central role in the global climate system, transporting climate relevant tracers such as heat and carbon. In satellite observations and numerical simulations, mesoscale vortices feature prominently as collectively rotating regions that remain visibly coherent. Prior studies on transport from ocean vortices typically rely on Eulerian identification methods, in which vortices are identified by selecting closed contours of Eulerian fields (e.g. sea surface height, or the Okubo-Weiss parameter) that satisfy geometric criteria and anomaly thresholds. In contrast, recent studies employ Lagrangian analysis of virtual particle trajectories initialized within the selected Eulerian contours, revealing significant discrepancies between the advection of the contour's material interior and the evolution of the Eulerian field contour. This work investigates the global mass and tracer transport associated with materially coherent surface ocean vortices. Further, it addresses differences between Eulerian and Lagrangian analyses for the detection of vortices. To do so, we use GFDL's CM2.6 coupled climate model with 5-10km horizontal grid spacing. We identify coherent vortices in CM2.6 by implementing the Rotationally Coherent Lagrangian Vortex (RCLV) framework, which recently emerged from dynamical systems theory. This approach involves the numerical advection of millions of Lagrangian particles and guarantees material coherence by construction. We compute the statistics, spatial distribution, and lifetimes of coherent vortices in addition to calculating the associated mass and tracer transports. We offer compelling evidence that Eulerian vortex methods are poorly suited to answer questions of mass and tracer transport.
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2013-02-13
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1881] Expansion/Reorganization of Foreign-Trade Subzone 70T; Marathon Petroleum Company LP; Detroit, MI Pursuant to its authority under the... Subzone 70T and remove Site 3 of the subzone at the Marathon Petroleum Company LP refinery in Detroit...
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Transformation of Deep Water Masses Along Lagrangian Upwelling Pathways in the Southern Ocean
NASA Astrophysics Data System (ADS)
Tamsitt, V.; Abernathey, R. P.; Mazloff, M. R.; Wang, J.; Talley, L. D.
2018-03-01
Upwelling of northern deep waters in the Southern Ocean is fundamentally important for the closure of the global meridional overturning circulation and delivers carbon and nutrient-rich deep waters to the sea surface. We quantify water mass transformation along upwelling pathways originating in the Atlantic, Indian, and Pacific and ending at the surface of the Southern Ocean using Lagrangian trajectories in an eddy-permitting ocean state estimate. Recent related work shows that upwelling in the interior below about 400 m depth is localized at hot spots associated with major topographic features in the path of the Antarctic Circumpolar Current, while upwelling through the surface layer is more broadly distributed. In the ocean interior upwelling is largely isopycnal; Atlantic and to a lesser extent Indian Deep Waters cool and freshen while Pacific deep waters are more stable, leading to a homogenization of water mass properties. As upwelling water approaches the mixed layer, there is net strong transformation toward lighter densities due to mixing of freshwater, but there is a divergence in the density distribution as Upper Circumpolar Deep Water tends become lighter and dense Lower Circumpolar Deep Water tends to become denser. The spatial distribution of transformation shows more rapid transformation at eddy hot spots associated with major topography where density gradients are enhanced; however, the majority of cumulative density change along trajectories is achieved by background mixing. We compare the Lagrangian analysis to diagnosed Eulerian water mass transformation to attribute the mechanisms leading to the observed transformation.
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77 FR 48127 - Approval of Subzone Status; Shimadzu USA Manufacturing, Inc., Canby, OR
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2012-08-13
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-52-2012] Approval of Subzone Status; Shimadzu USA Manufacturing, Inc., Canby, OR On May 8, 2012, the Executive Secretary of the Foreign-Trade Zones... subzone status subject to the existing activation limit of FTZ 45, on behalf of Shimadzu USA Manufacturing...
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78 FR 9884 - Approval of Subzone Status; Zimmer Manufacturing BV; Ponce, Puerto Rico
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2013-02-12
...; Zimmer Manufacturing BV; Ponce, Puerto Rico Pursuant to its authority under the Foreign-Trade Zones Act... subzone at the facility of Zimmer Manufacturing BV located in Ponce, Puerto Rico (FTZ Docket B-81-2012... hereby approves subzone status at the facility of Zimmer Manufacturing BV located in Ponce, Puerto Rico...
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78 FR 44928 - Approval of Subzone Status; Easton-Bell Sports, Inc.; Rantoul, Illinois
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2013-07-25
...; Easton-Bell Sports, Inc.; Rantoul, Illinois Pursuant to its authority under the Foreign-Trade Zones Act... to the Board for the establishment of a subzone at the facility of Easton-Bell Sports, Inc., located...-Bell Sports, Inc., located in Rantoul, Illinois (Subzone 114F), as described in the application and...
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77 FR 60103 - Approval of Subzone Status; TST NA TRIM, LLC; Hidalgo, TX
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2012-10-02
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-90-2012] Approval of Subzone Status; TST NA TRIM, LLC; Hidalgo, TX On August 3, 2012, the Executive Secretary of the Foreign-Trade Zones (FTZ..., requesting subzone status subject to the existing activation limit of FTZ 12, on behalf of TST NA TRIM, LLC...
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2010-09-08
... Valley, Pennsylvania, Application for Subzone, Piramal Critical Care, Inc. (Inhalation Anesthetics...), grantee of FTZ 272, requesting special-purpose subzone status for the inhalation anesthetics manufacturing.... The facilities are used for the manufacture and distribution of inhalation anesthetics Sevoflurane and...
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Lagrangian mass-flow investigations of inorganic contaminants in wastewater-impacted streams
Barber, L.B.; Antweiler, Ronald C.; Flynn, J.L.; Keefe, S.H.; Kolpin, D.W.; Roth, D.A.; Schnoebelen, D.J.; Taylor, Howard E.; Verplanck, P.L.
2011-01-01
Understanding the potential effects of increased reliance on wastewater treatment plant (WWTP) effluents to meet municipal, agricultural, and environmental flow requires an understanding of the complex chemical loading characteristics of the WWTPs and the assimilative capacity of receiving waters. Stream ecosystem effects are linked to proportions of WWTP effluent under low-flow conditions as well as the nature of the effluent chemical mixtures. This study quantifies the loading of 58 inorganic constituents (nutrients to rare earth elements) from WWTP discharges relative to upstream landscape-based sources. Stream assimilation capacity was evaluated by Lagrangian sampling, using flow velocities determined from tracer experiments to track the same parcel of water as it moved downstream. Boulder Creek, Colorado and Fourmile Creek, Iowa, representing two different geologic and hydrologic landscapes, were sampled under low-flow conditions in the summer and spring. One-half of the constituents had greater loads from the WWTP effluents than the upstream drainages, and once introduced into the streams, dilution was the predominant assimilation mechanism. Only ammonium and bismuth had significant decreases in mass load downstream from the WWTPs during all samplings. The link between hydrology and water chemistry inherent in Lagrangian sampling allows quantitative assessment of chemical fate across different landscapes. ?? 2011 American Chemical Society.
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2010-05-05
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15 CFR 400.25 - Application for subzone.
Code of Federal Regulations, 2011 CFR
2011-01-01
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2013-08-13
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-77-2013] Foreign-Trade Zone 84--Houston, Texas; Application for Subzone; Toshiba International Corporation; Houston, Texas An application has been submitted..., requesting subzone status for the facilities of Toshiba International Corporation located in Houston, Texas...
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2012-12-13
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-65-2012] Authorization of Production Activity, Foreign-Trade Subzone 107A, Winnebago Industries, Inc. (Polyurethane Coated Upholstery Fabric), Forest City and Charles City, IA On July 24, 2012, Winnebago Industries, Inc., operator of Subzone 107A in...
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15 CFR 400.25 - Application for subzone.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Application for subzone. 400.25 Section 400.25 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) FOREIGN-TRADE ZONES BOARD, DEPARTMENT OF COMMERCE REGULATIONS OF THE FOREIGN-TRADE ZONES BOARD...
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2013-01-14
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-2-2013] Foreign-Trade Zone 196--Fort Worth, TX, Foreign-Trade Subzone 196A--TTI, Inc.; Application for Additional Subzone Site An application has been submitted to the Foreign-Trade Zones Board (the Board) by Alliance Corridor, Inc., grantee of FTZ 196, requesting an additional site for Subzone...
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Vorticity and symplecticity in multi-symplectic, Lagrangian gas dynamics
NASA Astrophysics Data System (ADS)
Webb, G. M.; Anco, S. C.
2016-02-01
The Lagrangian, multi-dimensional, ideal, compressible gas dynamic equations are written in a multi-symplectic form, in which the Lagrangian fluid labels, m i (the Lagrangian mass coordinates) and time t are the independent variables, and in which the Eulerian position of the fluid element {x}={x}({m},t) and the entropy S=S({m},t) are the dependent variables. Constraints in the variational principle are incorporated by means of Lagrange multipliers. The constraints are: the entropy advection equation S t = 0, the Lagrangian map equation {{x}}t={u} where {u} is the fluid velocity, and the mass continuity equation which has the form J=τ where J={det}({x}{ij}) is the Jacobian of the Lagrangian map in which {x}{ij}=\\partial {x}i/\\partial {m}j and τ =1/ρ is the specific volume of the gas. The internal energy per unit volume of the gas \\varepsilon =\\varepsilon (ρ ,S) corresponds to a non-barotropic gas. The Lagrangian is used to define multi-momenta, and to develop de Donder-Weyl Hamiltonian equations. The de Donder-Weyl equations are cast in a multi-symplectic form. The pullback conservation laws and the symplecticity conservation laws are obtained. One class of symplecticity conservation laws give rise to vorticity and potential vorticity type conservation laws, and another class of symplecticity laws are related to derivatives of the Lagrangian energy conservation law with respect to the Lagrangian mass coordinates m i . We show that the vorticity-symplecticity laws can be derived by a Lie dragging method, and also by using Noether’s second theorem and a fluid relabelling symmetry which is a divergence symmetry of the action. We obtain the Cartan-Poincaré form describing the equations and we discuss a set of differential forms representing the equation system.
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2013-09-04
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-43-2013] Subzone 8I, Authorization of Production Activity, Whirlpool Corporation (Washing Machines); Clyde and Green Springs, Ohio On May 1, 2013...-Trade Zones (FTZ) Board for its facility within Subzone 8I, in Clyde and Green Springs, Ohio. The...
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2010-10-20
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2013-09-27
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-136-2013] Foreign-Trade Zone 83--Huntsville, Alabama, Application for Subzone, VF Jeanswear, Hackleburg, Alabama An application has been submitted to the Foreign-Trade Zones Board (the Board) by the Huntsville-Madison County Airport Authority, grantee of FTZ 83, requesting subzone status for th...
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2013-05-14
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-7-2013] Authorization of Production Activity; Foreign-Trade Subzone 29C; GE Appliances (Electric Water Heaters); Louisville, Kentucky On January 7, 2013, GE Appliances, operator of Subzone 29C in Louisville, Kentucky, submitted a notification of proposed...
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2010-11-30
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Docket 57-2010] Foreign-Trade Zone 148--Knoxville, TN, Application for Subzone Toho, Tenax America, Inc., Extension of Comment Period The comment period for the application for subzone status at the Toho Tenax America, Inc., facility in Rockwood...
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2012-03-21
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2012-09-11
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2011-01-25
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2012-05-15
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-52-2012] Foreign-Trade Zone 45--Portland, OR; Application for Subzone, Shimadzu USA Manufacturing, Inc., Canby, OR An application has been submitted to the...-purpose subzone status for the facility of Shimadzu USA Manufacturing, Inc. (SUM), located in Canby...
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2013-04-23
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-32-2013] Foreign-Trade Zone 114--Peoria, Illinois; Application for Subzone; Easton-Bell Sports, Inc.; Rantoul, Illinois An application has been..., grantee of FTZ 114, requesting special-purpose subzone status for the facility of Easton-Bell Sports, Inc...
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2012-05-15
... Status; North American Stainless, (Stainless Steel), Ghent, KY Pursuant to its authority under the... application to the Board for authority to establish a special-purpose subzone at the stainless steel mill of... stainless steel at the facility of North American Stainless, located in Ghent, Kentucky (Subzone 29L), as...
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2011-08-26
... Rock, AR; Application for Subzone; Mitsubishi Power Systems Americas, Inc. (Wind Turbine Nacelles and... subzone status for the wind turbine nacelle and generating set manufacturing facility of Mitsubishi Power.... The facility, currently under construction, will be used to manufacture and distribute wind turbine...
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2011-04-22
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1754] Grant of Authority for Subzone Status, Allegro Mfg. Inc. (Distribution of Cosmetic, Organizer and Electronic Bags and Accessories... grants authority for subzone status for activity related to cosmetic, organizer and electronic bags and...
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2013-09-09
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-47-2013] Authorization of Production Activity, Foreign-Trade Subzone 123E, Vestas Nacelles America, Inc., (Wind Turbines), Brighton, Denver, Pueblo, and Windsor, Colorado On May 3, 2013, Vestas Nacelles America, Inc., operator of Subzone 123E in Brighton, Denver, Pueblo, and Windsor, Colorado,...
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2010-02-02
..., Colorado, Application for Subzone, Vestas Nacelles America, Inc. (Wind Turbine Nacelles, Hubs, Blades and...-purpose subzone status for the wind turbine nacelle, hub, blade and tower manufacturing and warehousing... warehousing of wind turbines and related parts (up to 1,560 nacelles and hubs, 4,200 blades, and 1,100 towers...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-24
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-106-2013] Notification of Proposed Production Activity, Xylem Water Systems USA LLC, Subzone 37D, (Centrifugal, Submersible Pumps and Related Components), Auburn, New York Xylem Water Systems USA LLC (Xylem), operator of Subzone 37D, submitted a notification of proposed production activity to...
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An online-coupled NWP/ACT model with conserved Lagrangian levels
NASA Astrophysics Data System (ADS)
Sørensen, B.; Kaas, E.; Lauritzen, P. H.
2012-04-01
Numerical weather and climate modelling is under constant development. Semi-implicit semi-Lagrangian (SISL) models have proven to be numerically efficient in both short-range weather forecasts and climate models, due to the ability to use long time steps. Chemical/aerosol feedback mechanism are becoming more and more relevant in NWP as well as climate models, since the biogenic and anthropogenic emissions can have a direct effect on the dynamics and radiative properties of the atmosphere. To include chemical feedback mechanisms in the NWP models, on-line coupling is crucial. In 3D semi-Lagrangian schemes with quasi-Lagrangian vertical coordinates the Lagrangian levels are remapped to Eulerian model levels each time step. This remapping introduces an undesirable tendency to smooth sharp gradients and creates unphysical numerical diffusion in the vertical distribution. A semi-Lagrangian advection method is introduced, it combines an inherently mass conserving 2D semi-Lagrangian scheme, with a SISL scheme employing both hybrid vertical coordinates and a fully Lagrangian vertical coordinate. This minimizes the vertical diffusion and thus potentially improves the simulation of the vertical profiles of moisture, clouds, and chemical constituents. Since the Lagrangian levels suffer from traditional Lagrangian limitations caused by the convergence and divergence of the flow, remappings to the Eulerian model levels are generally still required - but this need only be applied after a number of time steps - unless dynamic remapping methods are used. For this several different remapping methods has been implemented. The combined scheme is mass conserving, consistent, and multi-tracer efficient.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-06
...--Knoxville, TN; Application for Subzone; Toho Tenax America, Inc. (Carbon Fiber and Oxidized..., requesting special-purpose subzone status for the carbon fiber and oxidized polyacrylonitrile fiber (OPF...)--based carbon fiber and OPF (up to 4,000 metric tons combined annually) for export and the domestic...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-14
..., Foreign-Trade Subzone 61H, Baxter Healthcare of Puerto Rico (Inhalation Anesthetics Manufacturing... inhalation anesthetics at Foreign-Trade Subzone 61H, at the facility of Baxter Healthcare of Puerto Rico.../7/1997) at the Baxter Healthcare of Puerto Rico (Baxter) (formerly Ohmeda Caribe Inc./Ohmeda...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-13
... Status; GE Transportation; Lawrence Park Township and Grove City, Pennsylvania On May 16, 2013, the... activation limit of FTZ 247, on behalf of GE Transportation, in Lawrence Park Township and Grove City... establish Subzone 247A in Lawrence Park Township and Subzone 247B in Grove City are approved, subject to the...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-11
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-65-2013] Foreign-Trade Zone 61--San Juan, Puerto Rico Application for Subzone, Parapiezas Corporation Amendment of Application The Puerto Rico Trade & Export Company, grantee of FTZ 61, has amended its application requesting subzone status for the facility of Parapiezas Corporation (78 FR 28800...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-27
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1829] Voluntary Termination of Foreign-Trade Subzone 33B Verosol USA, Inc. Kennedy Township, Allegheny County, PA Pursuant to the authority... the establishment of Foreign-Trade Subzone 33B at the Verosol USA, Inc., plant in Kennedy Township...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-02
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-38-2013] Foreign-Trade Zone 99--Wilmington, Delaware; Application for Expansion of Subzone 99E; Delaware City Refining Company LLC; New Castle County... (grantee of FTZ 99), through the Delaware Economic Development Office, requesting the expansion of Subzone...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-13
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-132-2012] Foreign-Trade Zone 7--Mayaguez, PR; Application for Subzone; Pepsi Cola Puerto Rico Distributing, LLC, Toa Baja, PR An application has been..., grantee of FTZ 7, requesting special-purpose subzone status for the facility of Pepsi Cola Puerto Rico...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-10-16
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-107-2012] Foreign-Trade Zone 61--San Juan, PR, Application for Subzone, Coamo Property & Investments, LLC, Coamo, PR An application has been submitted to the..., requesting special-purpose subzone status for the facility of Coamo Property & Investments, LLC, located in...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-09
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-75-2013] Subzone 38E, Authorization of Limited Production Activity, Black & Decker (U.S.) Inc., (Power Tools), Fort Mill, SC On July 19, 2013, Black... (FTZ) Board for its facility within Subzone 38E, in Fort Mill, South Carolina. The notification was...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-07
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-42-2012] Foreign-Trade Zone 70--Detroit, MI; Expansion of Subzone; Marathon Petroleum Company LP, (Oil Refinery) Detroit, MI An application has been...., grantee of FTZ 70, requesting an expansion of Subzone 70T, on behalf of Marathon Petroleum Company LP in...
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Impact Toughness of Subzones in the Intercritical Heat-Affected Zone of Low-Carbon Bainitic Steel.
Li, Zhenshun; Zhao, Xuemin; Shan, Dongri
2018-06-06
The subzones of the intercritical heat-affected zone (IC HAZ) of low-carbon bainitic steel were simulated by using a Gleeble-3500 simulator to study the impact toughness. The results showed that the IC HAZ is not entirely brittle and can be further divided into three subzones according to the impact toughness or peak welding temperature; the invariant subzone heated between the critical transformation start temperature ( A c1 ) and 770 °C exhibited unchanged high impact toughness. Furthermore, an extremely low impact toughness was found in the embrittlement subzone, heated between 770 and 830 °C, and the reduction subzone heated between 830 °C and the critical transformation finish temperature ( A c3 ) exhibited toughness below that of the original metal. The size of the blocky martensite-austenite (M-A) constituents was found to have a remarkable level of influence on the impact toughness when heated below 830 °C. Additionally, it was found that, once the constituent size exceeds a critical value of 3.0 µm at a peak temperature of 770 °C, the IC HAZ becomes brittle regardless of lath or twinned martensite constitution in the M-A constituent. Essentially, embrittlement was observed to occur when the resolved length of initial cracks (in the direction of the overall fracture) formed as a result of the debonding of M-A constituents exceeding the critical Griffith size. Furthermore, when the heating temperature exceeded 830 °C, the M-A constituents formed a slender shape, and the impact toughness increased as the area fraction of the slender M-A constituents decreased.
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A Vertically Lagrangian Finite-Volume Dynamical Core for Global Models
NASA Technical Reports Server (NTRS)
Lin, Shian-Jiann
2003-01-01
A finite-volume dynamical core with a terrain-following Lagrangian control-volume discretization is described. The vertically Lagrangian discretization reduces the dimensionality of the physical problem from three to two with the resulting dynamical system closely resembling that of the shallow water dynamical system. The 2D horizontal-to-Lagrangian-surface transport and dynamical processes are then discretized using the genuinely conservative flux-form semi-Lagrangian algorithm. Time marching is split- explicit, with large-time-step for scalar transport, and small fractional time step for the Lagrangian dynamics, which permits the accurate propagation of fast waves. A mass, momentum, and total energy conserving algorithm is developed for mapping the state variables periodically from the floating Lagrangian control-volume to an Eulerian terrain-following coordinate for dealing with physical parameterizations and to prevent severe distortion of the Lagrangian surfaces. Deterministic baroclinic wave growth tests and long-term integrations using the Held-Suarez forcing are presented. Impact of the monotonicity constraint is discussed.
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-17
...-Trade Subzone 33C; Sony Corporation of America, Mt. Pleasant, PA Pursuant to the authority granted in... Industrial Development Corporation of Southwestern Pennsylvania, (grantee of FTZ 33) authorizing the establishment of Foreign-Trade Subzone 33C at the Sony Corporation of America plant in Mt. Pleasant...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-03
... Activity, The Gas Company, LLC dba Hawai'i Gas, Subzone 9F (Synthetic Natural Gas), Kapolei, Hawaii The Gas... May 22, 2013. The subzone currently has authority to produce synthetic natural gas, carbon dioxide... during customs entry procedures that apply to synthetic natural gas, carbon dioxide, hydrogen...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-19
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-138-2012] Foreign-Trade Zone 61--San Juan, Puerto Rico; Application for Subzone; Sea World, Inc.; Guaynabo, PR An application has been submitted to..., requesting special-purpose subzone status for the facility of Sea World, Inc., located in Guaynabo, Puerto...
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Lagrangian formulation and symmetrical description of liquid dynamics.
Trachenko, K
2017-12-01
Theoretical description of liquids has been primarily based on the hydrodynamic approach and its generalization to the solid-like regime. We show that the same liquid properties can be derived starting from solid-like equations and generalizing them to account for the hydrodynamic flow. Both approaches predict propagating shear waves with the notable gap in k-space. This gives an important symmetry of liquids regarding their description. We subsequently construct a two-field Lagrangian of liquid dynamics where the dissipative hydrodynamic and solid-like terms are treated on equal footing. The Lagrangian predicts two gapped waves propagating in opposite space-time directions. The dissipative and mass terms compete by promoting gaps in k-space and energy, respectively. When bare mass is close to the field hopping frequency, both gaps close and the dissipative term annihilates the bare mass.
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Lagrangian formulation and symmetrical description of liquid dynamics
NASA Astrophysics Data System (ADS)
Trachenko, K.
2017-12-01
Theoretical description of liquids has been primarily based on the hydrodynamic approach and its generalization to the solid-like regime. We show that the same liquid properties can be derived starting from solid-like equations and generalizing them to account for the hydrodynamic flow. Both approaches predict propagating shear waves with the notable gap in k -space. This gives an important symmetry of liquids regarding their description. We subsequently construct a two-field Lagrangian of liquid dynamics where the dissipative hydrodynamic and solid-like terms are treated on equal footing. The Lagrangian predicts two gapped waves propagating in opposite space-time directions. The dissipative and mass terms compete by promoting gaps in k -space and energy, respectively. When bare mass is close to the field hopping frequency, both gaps close and the dissipative term annihilates the bare mass.
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77 FR 47816 - Foreign-Trade Zone 12-McAllen, TX Application for Subzone TST NA TRIM, LLC Hidalgo, TX
Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-10
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-90-2012] Foreign-Trade Zone 12--McAllen, TX Application for Subzone TST NA TRIM, LLC Hidalgo, TX An application has been submitted to the Foreign-Trade...-purpose subzone status for the facility of TST NA TRIM, LLC, located in Hidalgo, Texas. The application...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-09-10
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-100-2013] Foreign-Trade Zone 79--Tampa, Florida, Foreign-Trade Subzone 79C--Cutrale Citrus Juices USA, Inc., Approval of Additional Subzone Sites, Dade City and Leesburg, Florida On June 24, 2013, the Acting Executive Secretary of the Foreign- Trade Zones (FTZ) Board docketed an application...
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Bayesian Lagrangian Data Assimilation and Drifter Deployment Strategies
NASA Astrophysics Data System (ADS)
Dutt, A.; Lermusiaux, P. F. J.
2017-12-01
Ocean currents transport a variety of natural (e.g. water masses, phytoplankton, zooplankton, sediments, etc.) and man-made materials and other objects (e.g. pollutants, floating debris, search and rescue, etc.). Lagrangian Coherent Structures (LCSs) or the most influential/persistent material lines in a flow, provide a robust approach to characterize such Lagrangian transports and organize classic trajectories. Using the flow-map stochastic advection and a dynamically-orthogonal decomposition, we develop uncertainty prediction schemes for both Eulerian and Lagrangian variables. We then extend our Bayesian Gaussian Mixture Model (GMM)-DO filter to a joint Eulerian-Lagrangian Bayesian data assimilation scheme. The resulting nonlinear filter allows the simultaneous non-Gaussian estimation of Eulerian variables (e.g. velocity, temperature, salinity, etc.) and Lagrangian variables (e.g. drifter/float positions, trajectories, LCSs, etc.). Its results are showcased using a double-gyre flow with a random frequency, a stochastic flow past a cylinder, and realistic ocean examples. We further show how our Bayesian mutual information and adaptive sampling equations provide a rigorous efficient methodology to plan optimal drifter deployment strategies and predict the optimal times, locations, and types of measurements to be collected.
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-28
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-100-2013] Foreign-Trade Zone 79--Tampa, Florida, Foreign-Trade Subzone 79C--Cutrale Citrus Juices USA, Inc., Application for Additional Subzone Sites An application has been submitted to the Foreign-Trade Zones Board (the Board) by the City of Tampa, grantee of FTZ 79, requesting two additional...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-06
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-2-2013] Foreign-Trade Zone 196--Fort Worth, TX, Foreign-Trade Subzone 196A--TTI, Inc., Approval of Additional Subzone Site, Fort Worth, TX On January 4, 2013, the Executive Secretary of the Foreign-Trade Zones (FTZ) Board docketed an application submitted by Alliance Corridor, Inc., grantee of...
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An Eulerian/Lagrangian coupling procedure for three-dimensional vortical flows
NASA Technical Reports Server (NTRS)
Felici, Helene M.; Drela, Mark
1993-01-01
A coupled Eulerian/Lagrangian method is presented for the reduction of numerical diffusion observed in solutions of 3D vortical flows using standard Eulerian finite-volume time-marching procedures. A Lagrangian particle tracking method, added to the Eulerian time-marching procedure, provides a correction of the Eulerian solution. In turn, the Eulerian solution is used to integrate the Lagrangian state-vector along the particles trajectories. While the Eulerian solution ensures the conservation of mass and sets the pressure field, the particle markers describe accurately the convection properties and enhance the vorticity and entropy capturing capabilities of the Eulerian solver. The Eulerian/Lagrangian coupling strategies are discussed and the combined scheme is tested on a constant stagnation pressure flow in a 90 deg bend and on a swirling pipe flow. As the numerical diffusion is reduced when using the Lagrangian correction, a vorticity gradient augmentation is identified as a basic problem of this inviscid calculation.
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Some Lagrangians for systems without a Lagrangian
NASA Astrophysics Data System (ADS)
Nucci, M. C.; Leach, P. G. L.
2011-03-01
We demonstrate how to construct many different Lagrangians for two famous examples that were deemed by Douglas (1941 Trans. Am. Math. Soc. 50 71-128) not to have a Lagrangian. Following Bateman's dictum (1931 Phys. Rev. 38 815-9), we determine different sets of equations that are compatible with those of Douglas and derivable from a variational principle.
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15 CFR 400.21 - Number and location of zones and subzones.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Number and location of zones and subzones. 400.21 Section 400.21 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) FOREIGN-TRADE ZONES BOARD, DEPARTMENT OF COMMERCE REGULATIONS OF THE FOREIGN-TRADE...
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A Lagrangian discontinuous Galerkin hydrodynamic method
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Xiaodong; Morgan, Nathaniel Ray; Burton, Donald E.
Here, we present a new Lagrangian discontinuous Galerkin (DG) hydrodynamic method for solving the two-dimensional gas dynamic equations on unstructured hybrid meshes. The physical conservation laws for the momentum and total energy are discretized using a DG method based on linear Taylor expansions. Three different approaches are investigated for calculating the density variation over the element. The first approach evolves a Taylor expansion of the specific volume field. The second approach follows certain finite element methods and uses the strong mass conservation to calculate the density field at a location inside the element or on the element surface. The thirdmore » approach evolves a Taylor expansion of the density field. The nodal velocity, and the corresponding forces, are explicitly calculated by solving a multidirectional approximate Riemann problem. An effective limiting strategy is presented that ensures monotonicity of the primitive variables. This new Lagrangian DG hydrodynamic method conserves mass, momentum, and total energy. Results from a suite of test problems are presented to demonstrate the robustness and expected second-order accuracy of this new method.« less
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A Lagrangian discontinuous Galerkin hydrodynamic method
Liu, Xiaodong; Morgan, Nathaniel Ray; Burton, Donald E.
2017-12-11
Here, we present a new Lagrangian discontinuous Galerkin (DG) hydrodynamic method for solving the two-dimensional gas dynamic equations on unstructured hybrid meshes. The physical conservation laws for the momentum and total energy are discretized using a DG method based on linear Taylor expansions. Three different approaches are investigated for calculating the density variation over the element. The first approach evolves a Taylor expansion of the specific volume field. The second approach follows certain finite element methods and uses the strong mass conservation to calculate the density field at a location inside the element or on the element surface. The thirdmore » approach evolves a Taylor expansion of the density field. The nodal velocity, and the corresponding forces, are explicitly calculated by solving a multidirectional approximate Riemann problem. An effective limiting strategy is presented that ensures monotonicity of the primitive variables. This new Lagrangian DG hydrodynamic method conserves mass, momentum, and total energy. Results from a suite of test problems are presented to demonstrate the robustness and expected second-order accuracy of this new method.« less
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Lagrangian averages, averaged Lagrangians, and the mean effects of fluctuations in fluid dynamics.
Holm, Darryl D.
2002-06-01
We begin by placing the generalized Lagrangian mean (GLM) equations for a compressible adiabatic fluid into the Euler-Poincare (EP) variational framework of fluid dynamics, for an averaged Lagrangian. This is the Lagrangian averaged Euler-Poincare (LAEP) theorem. Next, we derive a set of approximate small amplitude GLM equations (glm equations) at second order in the fluctuating displacement of a Lagrangian trajectory from its mean position. These equations express the linear and nonlinear back-reaction effects on the Eulerian mean fluid quantities by the fluctuating displacements of the Lagrangian trajectories in terms of their Eulerian second moments. The derivation of the glm equations uses the linearized relations between Eulerian and Lagrangian fluctuations, in the tradition of Lagrangian stability analysis for fluids. The glm derivation also uses the method of averaged Lagrangians, in the tradition of wave, mean flow interaction. Next, the new glm EP motion equations for incompressible ideal fluids are compared with the Euler-alpha turbulence closure equations. An alpha model is a GLM (or glm) fluid theory with a Taylor hypothesis closure. Such closures are based on the linearized fluctuation relations that determine the dynamics of the Lagrangian statistical quantities in the Euler-alpha equations. Thus, by using the LAEP theorem, we bridge between the GLM equations and the Euler-alpha closure equations, through the small-amplitude glm approximation in the EP variational framework. We conclude by highlighting a new application of the GLM, glm, and alpha-model results for Lagrangian averaged ideal magnetohydrodynamics. (c) 2002 American Institute of Physics.
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Unsteady force estimation using a Lagrangian drift-volume approach
NASA Astrophysics Data System (ADS)
McPhaden, Cameron J.; Rival, David E.
2018-04-01
A novel Lagrangian force estimation technique for unsteady fluid flows has been developed, using the concept of a Darwinian drift volume to measure unsteady forces on accelerating bodies. The construct of added mass in viscous flows, calculated from a series of drift volumes, is used to calculate the reaction force on an accelerating circular flat plate, containing highly-separated, vortical flow. The net displacement of fluid contained within the drift volumes is, through Darwin's drift-volume added-mass proposition, equal to the added mass of the plate and provides the reaction force of the fluid on the body. The resultant unsteady force estimates from the proposed technique are shown to align with the measured drag force associated with a rapid acceleration. The critical aspects of understanding unsteady flows, relating to peak and time-resolved forces, often lie within the acceleration phase of the motions, which are well-captured by the drift-volume approach. Therefore, this Lagrangian added-mass estimation technique opens the door to fluid-dynamic analyses in areas that, until now, were inaccessible by conventional means.
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Learn the Lagrangian: A Vector-Valued RKHS Approach to Identifying Lagrangian Systems.
Cheng, Ching-An; Huang, Han-Pang
2016-12-01
We study the modeling of Lagrangian systems with multiple degrees of freedom. Based on system dynamics, canonical parametric models require ad hoc derivations and sometimes simplification for a computable solution; on the other hand, due to the lack of prior knowledge in the system's structure, modern nonparametric models in machine learning face the curse of dimensionality, especially in learning large systems. In this paper, we bridge this gap by unifying the theories of Lagrangian systems and vector-valued reproducing kernel Hilbert space. We reformulate Lagrangian systems with kernels that embed the governing Euler-Lagrange equation-the Lagrangian kernels-and show that these kernels span a subspace capturing the Lagrangian's projection as inverse dynamics. By such property, our model uses only inputs and outputs as in machine learning and inherits the structured form as in system dynamics, thereby removing the need for the mundane derivations for new systems as well as the generalization problem in learning from scratches. In effect, it learns the system's Lagrangian, a simpler task than directly learning the dynamics. To demonstrate, we applied the proposed kernel to identify the robot inverse dynamics in simulations and experiments. Our results present a competitive novel approach to identifying Lagrangian systems, despite using only inputs and outputs.
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Mang, Andreas; Ruthotto, Lars
2017-01-01
We present an efficient solver for diffeomorphic image registration problems in the framework of Large Deformations Diffeomorphic Metric Mappings (LDDMM). We use an optimal control formulation, in which the velocity field of a hyperbolic PDE needs to be found such that the distance between the final state of the system (the transformed/transported template image) and the observation (the reference image) is minimized. Our solver supports both stationary and non-stationary (i.e., transient or time-dependent) velocity fields. As transformation models, we consider both the transport equation (assuming intensities are preserved during the deformation) and the continuity equation (assuming mass-preservation). We consider the reduced form of the optimal control problem and solve the resulting unconstrained optimization problem using a discretize-then-optimize approach. A key contribution is the elimination of the PDE constraint using a Lagrangian hyperbolic PDE solver. Lagrangian methods rely on the concept of characteristic curves. We approximate these curves using a fourth-order Runge-Kutta method. We also present an efficient algorithm for computing the derivatives of the final state of the system with respect to the velocity field. This allows us to use fast Gauss-Newton based methods. We present quickly converging iterative linear solvers using spectral preconditioners that render the overall optimization efficient and scalable. Our method is embedded into the image registration framework FAIR and, thus, supports the most commonly used similarity measures and regularization functionals. We demonstrate the potential of our new approach using several synthetic and real world test problems with up to 14.7 million degrees of freedom.
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Lagrangian description of warm plasmas
NASA Technical Reports Server (NTRS)
Kim, H.
1970-01-01
Efforts are described to extend the averaged Lagrangian method of describing small signal wave propagation and nonlinear wave interaction, developed by earlier workers for cold plasmas, to the more general conditions of warm collisionless plasmas, and to demonstrate particularly the effectiveness of the method in analyzing wave-wave interactions. The theory is developed for both the microscopic description and the hydrodynamic approximation to plasma behavior. First, a microscopic Lagrangian is formulated rigorously, and expanded in terms of perturbations about equilibrium. Two methods are then described for deriving a hydrodynamic Lagrangian. In the first of these, the Lagrangian is obtained by velocity integration of the exact microscopic Lagrangian. In the second, the expanded hydrodynamic Lagrangian is obtained directly from the expanded microscopic Lagrangian. As applications of the microscopic Lagrangian, the small-signal dispersion relations and the coupled mode equations are derived for all possible waves in a warm infinite, weakly inhomogeneous magnetoplasma, and their interactions are examined.
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-22
..., Pennsylvania; Application for Subzone; Teva Pharmaceuticals USA, Inc.; North Wales, Chalfont, Kutztown and Sellersville, Pennsylvania An application has been submitted to the Foreign-Trade Zones Board (the Board) by... Sellersville, Pennsylvania. The [[Page 17635
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78 FR 4124 - Approval of Subzone Status, Coamo Property & Investments, LLC, Coamo, PR
Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-18
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-107-2012] Approval of Subzone Status, Coamo Property & Investments, LLC, Coamo, PR On October 9, 2012, the Executive Secretary of the Foreign-Trade... the proposed operator, Coamo Property & Investments, LLC, in Coamo, Puerto Rico. The application was...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-12
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Docket 61-2011] Foreign-Trade Zone 140--Flint, Michigan; Application for Subzone; Hemlock Semiconductor Corporation (Polysilicon); Hemlock, MI An... Hemlock Semiconductor Corporation (HSC), located in Hemlock, Michigan. The application was submitted...
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78 FR 13625 - Approval of Subzone Status; Sea World, Inc.; Guaynabo, Puerto Rico
Federal Register 2010, 2011, 2012, 2013, 2014
2013-02-28
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-138-2012] Approval of Subzone Status; Sea World, Inc.; Guaynabo, Puerto Rico On December 12, 2012, the Executive Secretary of the Foreign-Trade... Sea World, Inc., in Guaynabo, Puerto Rico. The application was processed in accordance with the FTZ...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-10-16
... Activities: Petroleum Refineries in Foreign Trade Sub-zones AGENCY: U.S. Customs and Border Protection... Budget (OMB) for review and approval in accordance with the Paperwork Reduction Act: Petroleum Refineries... CBP is soliciting comments concerning the following information collection: Title: Petroleum...
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About non standard Lagrangians in cosmology
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dimitrijevic, Dragoljub D.; Milosevic, Milan
A review of non standard Lagrangians present in modern cosmological models will be considered. Well known example of non standard Lagrangian is Dirac-Born-Infeld (DBI) type Lagrangian for tachyon field. Another type of non standard Lagrangian under consideration contains scalar field which describes open p-adic string tachyon and is called p-adic string theory Lagrangian. We will investigate homogenous cases of both DBI and p-adic fields and obtain Lagrangians of the standard type which have the same equations of motions as aforementioned non standard one.
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15 CFR 400.23 - Criteria for grants of authority for zones and subzones.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Criteria for grants of authority for zones and subzones. 400.23 Section 400.23 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) FOREIGN-TRADE ZONES BOARD, DEPARTMENT OF COMMERCE REGULATIONS OF THE...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-11-15
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-70-2013] Subzone 183B; Authorization of Production Activity; Samsung Austin Semiconductor, LLC (Semiconductors); Austin, Texas On June 26, 2013, Samsung Austin Semiconductor, LLC submitted a notification of proposed export production activity to the...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-22
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [T-1-2011] Foreign-Trade Zone Subzone 22-- Chicago, IL, Temporary/Interim Manufacturing Authority, Baxter Healthcare Corporation (Pharmaceutical and... Healthcare Corporation (Baxter) to manufacture pharmaceutical and biological intravenous (I.V.) products...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-10
...), high thread count (180 threads per inch and higher) fabrics under FTZ procedures based on a tolling... process any other customer- owned fabric under FTZ procedures. Subzone status would allow for deferral of...
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76 FR 47540 - Voluntary Termination of Subzone Status; Chrysler Group, LLC, Newark, DE
Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-05
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1775] Voluntary Termination of Subzone Status; Chrysler Group, LLC, Newark, DE Pursuant to its authority under the Foreign-Trade Zones Act of June 18, 1934, as amended (19 U.S.C. 81a-81u), the Foreign-Trade Zones Board (the Board) adopts the...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-12
... Activity TTI, Inc.; Subzone 196A (Electromechanical and Circuit Protection Devices Production/ Kitting... electromechanical and circuit protection device production/kitting for a variety of commercial, aerospace and... for crimping, insertion/extraction, and terminal removal, and electromechanical devices (duty rates...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-25
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Docket 60-2010] Foreign-Trade Zone 22-Chicago, IL, Application for Subzone Baxter Healthcare Corporation (Pharmaceutical and Biological Product... Healthcare Corporation (Baxter), located near Round Lake (Lake County), Illinois. The application was...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-26
... Status; IKEA Distribution Services (Distribution of Home Furnishings and Accessories); Baltimore, MD... subzone at the warehouse and distribution facility of IKEA Distribution Services, located in Perryville... and distribution at the facility of IKEA Distribution Services, located in Perryville, Maryland...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-07
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1686] Grant of Authority for Subzone... expedite and encourage foreign commerce, and for other purposes,'' and authorizes the Foreign-Trade Zones... cannot serve the specific use involved, and when the activity results in a significant public benefit and...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-22
..., Pennsylvania; Application for Subzone; GE Transportation, Lawrence Park Township, Pennsylvania An application... Transportation, located in Lawrence Park Township, Pennsylvania. The application was submitted pursuant to the... located at 2901 East Lake Road, Lawrence Park Township, Erie County, Pennsylvania. No production activity...
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Surveys of arthropod and gastropod diversity in the geothermal resource subzones, Puna, Hawaii
DOE Office of Scientific and Technical Information (OSTI.GOV)
Miller, S.E.; Burgett, J.; Bruegmann, M.
1995-04-01
The invertebrate surveys reported here were carried out as part of ecological studies funded by the Department of Energy in support of their environmental impact statement (EIS) for the Hawaii Geothermal Project. Currently, preparation of the EIS has been suspended, and all supporting information is being archived and made available to the public. The invertebrate surveys reported here assessed diversity and abundance of the arthropod and gastropod fauna in forested habitat and lava tubes in or near the three geothermal resource subzones. Recommendations for conservation of these organisms are given in this report. Surveys were conducted along three 100-m transectmore » lines at each of the six forested locations. Malaise traps, baited pitfall traps, yellow pan traps, baited sponge lures, and visual examination of vegetation were used to assess invertebrate diversity along each transect line. Three of these locations were adjacent to roads, and three were adjacent to lava flows. Two of these lava-forest locations (Keauohana Forest Reserve and Pu`u O`o) were relatively remote from direct human impacts. The third location (Southeast Kula) was near a low-density residential area. Two lava tubes were surveyed. The forest over one of these tubes (Keokea tube) had recently been burned away. This tube was used to assess the effects of loss of forest habitat on the subterranean fauna. An undisturbed tube (Pahoa tube) was used as a control. Recommendations offered in this report direct geothermal development away from areas of high endemic diversity and abundance, and toward areas where natural Hawaiian biotic communities have already been greatly disturbed. These disturbed areas are mainly found in the lower half of the Kamaili (middle) geothermal subzone and throughout most of the Kapoho (lower) geothermal subzone. These recommendation may also generally apply to other development projects in the Puna District.« less
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-21
... Charles City, IA Winnebago Industries, Inc. (Winnebago), operator of Subzone 107A, submitted a notification of proposed production activity for their facilities in Forest City and Charles City, Iowa. The... closing period for their receipt is October 1, 2012. A copy of the notification will be available for...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-18
... Status; SICK, Inc. (Photo- Electronic Industrial Sensors); Bloomington, MN Pursuant to its authority... to establish a special- purpose subzone at the photo-electronic industrial sensor manufacturing and... manufacturing and distribution of photo-electronic industrial sensors at the SICK, Inc., facility located in...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-02
... Status; South Florida Materials Corporation (Distribution of Petroleum Products); Port Everglades, FL... petroleum product storage and distribution facility of South Florida Materials Corporation (d/b/a Vencenergy..., therefore, the Board hereby grants authority for subzone status for activity related to petroleum product...
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A Godunov-like point-centered essentially Lagrangian hydrodynamic approach
DOE Office of Scientific and Technical Information (OSTI.GOV)
Morgan, Nathaniel R.; Waltz, Jacob I.; Burton, Donald E.
We present an essentially Lagrangian hydrodynamic scheme suitable for modeling complex compressible flows on tetrahedron meshes. The scheme reduces to a purely Lagrangian approach when the flow is linear or if the mesh size is equal to zero; as a result, we use the term essentially Lagrangian for the proposed approach. The motivation for developing a hydrodynamic method for tetrahedron meshes is because tetrahedron meshes have some advantages over other mesh topologies. Notable advantages include reduced complexity in generating conformal meshes, reduced complexity in mesh reconnection, and preserving tetrahedron cells with automatic mesh refinement. A challenge, however, is tetrahedron meshesmore » do not correctly deform with a lower order (i.e. piecewise constant) staggered-grid hydrodynamic scheme (SGH) or with a cell-centered hydrodynamic (CCH) scheme. The SGH and CCH approaches calculate the strain via the tetrahedron, which can cause artificial stiffness on large deformation problems. To resolve the stiffness problem, we adopt the point-centered hydrodynamic approach (PCH) and calculate the evolution of the flow via an integration path around the node. The PCH approach stores the conserved variables (mass, momentum, and total energy) at the node. The evolution equations for momentum and total energy are discretized using an edge-based finite element (FE) approach with linear basis functions. A multidirectional Riemann-like problem is introduced at the center of the tetrahedron to account for discontinuities in the flow such as a shock. Conservation is enforced at each tetrahedron center. The multidimensional Riemann-like problem used here is based on Lagrangian CCH work [8, 19, 37, 38, 44] and recent Lagrangian SGH work [33-35, 39, 45]. In addition, an approximate 1D Riemann problem is solved on each face of the nodal control volume to advect mass, momentum, and total energy. The 1D Riemann problem produces fluxes [18] that remove a volume error in the PCH
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A Godunov-like point-centered essentially Lagrangian hydrodynamic approach
Morgan, Nathaniel R.; Waltz, Jacob I.; Burton, Donald E.; ...
2014-10-28
We present an essentially Lagrangian hydrodynamic scheme suitable for modeling complex compressible flows on tetrahedron meshes. The scheme reduces to a purely Lagrangian approach when the flow is linear or if the mesh size is equal to zero; as a result, we use the term essentially Lagrangian for the proposed approach. The motivation for developing a hydrodynamic method for tetrahedron meshes is because tetrahedron meshes have some advantages over other mesh topologies. Notable advantages include reduced complexity in generating conformal meshes, reduced complexity in mesh reconnection, and preserving tetrahedron cells with automatic mesh refinement. A challenge, however, is tetrahedron meshesmore » do not correctly deform with a lower order (i.e. piecewise constant) staggered-grid hydrodynamic scheme (SGH) or with a cell-centered hydrodynamic (CCH) scheme. The SGH and CCH approaches calculate the strain via the tetrahedron, which can cause artificial stiffness on large deformation problems. To resolve the stiffness problem, we adopt the point-centered hydrodynamic approach (PCH) and calculate the evolution of the flow via an integration path around the node. The PCH approach stores the conserved variables (mass, momentum, and total energy) at the node. The evolution equations for momentum and total energy are discretized using an edge-based finite element (FE) approach with linear basis functions. A multidirectional Riemann-like problem is introduced at the center of the tetrahedron to account for discontinuities in the flow such as a shock. Conservation is enforced at each tetrahedron center. The multidimensional Riemann-like problem used here is based on Lagrangian CCH work [8, 19, 37, 38, 44] and recent Lagrangian SGH work [33-35, 39, 45]. In addition, an approximate 1D Riemann problem is solved on each face of the nodal control volume to advect mass, momentum, and total energy. The 1D Riemann problem produces fluxes [18] that remove a volume error in the PCH
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Form of the manifestly covariant Lagrangian
NASA Astrophysics Data System (ADS)
Johns, Oliver Davis
1985-10-01
The preferred form for the manifestly covariant Lagrangian function of a single, charged particle in a given electromagnetic field is the subject of some disagreement in the textbooks. Some authors use a ``homogeneous'' Lagrangian and others use a ``modified'' form in which the covariant Hamiltonian function is made to be nonzero. We argue in favor of the ``homogeneous'' form. We show that the covariant Lagrangian theories can be understood only if one is careful to distinguish quantities evaluated on the varied (in the sense of the calculus of variations) world lines from quantities evaluated on the unvaried world lines. By making this distinction, we are able to derive the Hamilton-Jacobi and Klein-Gordon equations from the ``homogeneous'' Lagrangian, even though the covariant Hamiltonian function is identically zero on all world lines. The derivation of the Klein-Gordon equation in particular gives Lagrangian theoretical support to the derivations found in standard quantum texts, and is also shown to be consistent with the Feynman path-integral method. We conclude that the ``homogeneous'' Lagrangian is a completely adequate basis for covariant Lagrangian theory both in classical and quantum mechanics. The article also explores the analogy with the Fermat theorem of optics, and illustrates a simple invariant notation for the Lagrangian and other four-vector equations.
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-20
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-20-2013] Authorization of Production Activity; Subzone 196A; TTI, Inc. (Electromechanical and Circuit Protection Devices Production/Kitting); Fort Worth, Texas On February 13, 2013, TTI, Inc. submitted a notification of proposed production activity to the...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-01
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1687] Grant of Authority for Subzone Status; Abercrombie & Fitch (Footwear and Apparel Distribution); New Albany, OH Pursuant to its authority... footwear and apparel warehousing and distribution at the facility of Abercrombie & Fitch, located in New...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-04-18
...; Application for Expansion; North American Shipbuilding, LLC (Shipbuilding), Houma, LA An application has been... FTZ 124, on behalf of North American Shipbuilding, LLC (NAS), operator of Subzone 124B at NAS' shipbuilding facilities in Larose, Houma, and Port Fourchon, Louisiana, requesting authority to expand the...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-27
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1834] Approval for Expanded Manufacturing Authority; Foreign-Trade Subzone 7M; Amgen Manufacturing Limited (Biotechnology and Healthcare Products); Juncos, Puerto Rico Pursuant to its authority under the Foreign-Trade Zones Act of June 18, 1934...
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Gravitational Lagrangians, Mach's Principle, and the Equivalence Principle in an Expanding Universe
NASA Astrophysics Data System (ADS)
Essén, Hanno
2014-08-01
Gravitational Lagrangians as derived by Fock for the Einstein-Infeld-Hoffmann approach, and by Kennedy assuming only a fourth rank tensor interaction, contain long range interactions. Here we investigate how these affect the local dynamics when integrated over an expanding universe out to the Hubble radius. Taking the cosmic expansion velocity into account in a heuristic manner it is found that these long range interactions imply Mach's principle, provided the universe has the critical density, and that mass is renormalized. Suitable higher order additions to the Lagrangians make the formalism consistent with the equivalence principle.
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-12
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Docket 62-2011] Foreign-Trade Zone 78--Nashville, TN, Application for Subzone, Hemlock Semiconductor, L.L.C. (Polysilicon); Clarksville, TN An... polysilicon manufacturing facility of [[Page 63282
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-21
..., California, Application for Subzone, Louisville Bedding Company (Household Bedding Products), Ontario... Avenue in Ontario, California. The facility is used to manufacture household bedding products, including... shipments for the domestic market, the finished household bedding products would be entered for consumption...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-09-03
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1700] Grant of Authority for Subzone... expedite and encourage foreign commerce, and for other purposes,'' and authorizes the Foreign-Trade Zones... cannot serve the specific use involved, and when the activity results in a significant public benefit and...
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Extreme Lagrangian acceleration in confined turbulent flow.
Kadoch, Benjamin; Bos, Wouter J T; Schneider, Kai
2008-05-09
A Lagrangian study of two-dimensional turbulence for two different geometries, a periodic and a confined circular geometry, is presented to investigate the influence of solid boundaries on the Lagrangian dynamics. It is found that the Lagrangian acceleration is even more intermittent in the confined domain than in the periodic domain. The flatness of the Lagrangian acceleration as a function of the radius shows that the influence of the wall on the Lagrangian dynamics becomes negligible in the center of the domain, and it also reveals that the wall is responsible for the increased intermittency. The transition in the Lagrangian statistics between this region, not directly influenced by the walls, and a critical radius which defines a Lagrangian boundary layer is shown to be very sharp with a sudden increase of the acceleration flatness from about 5 to about 20.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-10
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1724] Grant of Authority for Subzone... United States, to expedite and encourage foreign commerce, and for other purposes,'' and authorizes the... benefit and is in the public interest; Whereas, the City of San Jose, California, grantee of Foreign-Trade...
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"Lagrangian" for a Non-Lagrangian Field Theory with N=2 Supersymmetry.
Gadde, Abhijit; Razamat, Shlomo S; Willett, Brian
2015-10-23
We suggest that at least some of the strongly coupled N=2 quantum field theories in 4D can have a nonconformal N=1 Lagrangian description flowing to them at low energies. In particular, we construct such a description for the N=2 rank one superconformal field theory with E(6) flavor symmetry, for which a Lagrangian description was previously unavailable. We utilize this description to compute several supersymmetric partition functions.
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-11-25
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1798] Approval for Expansion of Manufacturing Authority, Foreign-Trade Subzone 29F, Hitachi Automotive Systems Americas, Inc., (Automotive... requested an expansion of the scope of manufacturing authority on behalf of Hitachi Automotive Systems...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-11-01
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1794] Approval for Expanded Manufacturing Authority; Foreign-Trade Subzone 158D Nissan North America, Inc.; (Motor Vehicles) Canton, MS...), the Foreign-Trade Zones Board (the Board) adopts the following Order. Whereas, Nissan North America...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-12-09
... 140 and 78; Applications for Subzone Authority; Dow Corning Corporation, Hemlock Semiconductor Corporation and Hemlock Semiconductor, L.L.C.; Extension of Comment Periods The comment periods for the...- 63283, October 12, 2011), at the Hemlock Semiconductor Corporation facility in Hemlock, Michigan (76 FR...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-24
... Activity; Vestas Nacelles America, Inc.; Subzone 123E (Wind Turbines); Brighton, Denver, Pueblo, and... during customs entry procedures that apply to wind turbines, nacelles, hubs, blades, and towers (free, 2...; dehumidifiers; cooling units; condensate heaters; heat exchangers; slip rings; filters; kabi sprayers; bearings...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-12
... Status, Reynolds Packaging LLC (Aluminum Foil Liner Stock), Louisville, Kentucky Pursuant to its...-purpose subzone at the aluminum foil liner stock manufacturing and distribution facilities of Reynolds... manufacturing and distribution of aluminum foil liner stock and aluminum foil at the facilities of Reynolds...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-02
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1682] Grant of Authority For Subzone Status; Deere & Company (Agricultural Equipment and Component Parts); Waterloo, IA Pursuant to its authority under the Foreign-Trade Zones Act of June 18, 1934, as amended (19 U.S.C. 81a-81u), the Foreign...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-02-01
... Activity; GE Appliances; Subzone 29C (Electric Water Heaters), Louisville, KY GE Appliances, operator of... using certain foreign components. The current request involves the production of electric water heaters... procedures that applies to electric hot water heaters (free) for the foreign status inputs noted below...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-22
..., Pennsylvania, Application for Subzone, GE Transportation, Grove City, Pennsylvania An application has been submitted to the Foreign-Trade Zones Board (the Board) by the Erie-Western Pennsylvania Port Authority..., located in Grove City, Pennsylvania. The application was submitted pursuant to the provisions of the...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-21
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1791] Grant of Authority for Subzone... United States, to expedite and encourage foreign commerce, and for other purposes,'' and authorizes the... benefit and is in the public interest; Whereas, the West Virginia Economic Development Authority, grantee...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-10
..., gears, pulleys, oil coolers, water pumps, cable, motors, thermostats, electrical components, wiring... merchandise is shipped from the facility and entered for U.S. consumption. Subzone status would further allow Cummins to realize logistical benefits through the use of weekly customs entry procedures. The application...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-23
... 140 and 78, Applications for Subzone Authority, Dow Corning Corporation, Hemlock Semiconductor Corporation, and Hemlock Semiconductor, L.L.C.; Reopening of Comment Periods The comment periods for the...- 63283, 10/12/2011), at the Hemlock Semiconductor Corporation facility in Hemlock, Michigan (76 FR 63282...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-09
... 140 and 78, Applications for Subzone Authority Dow Corning Corporation, Hemlock Semiconductor Corporation, and Hemlock Semiconductor, L.L.C.; Reopening of Rebuttal Periods The rebuttal periods for the...- 63283, 10/12/2011), at the Hemlock Semiconductor Corporation facility in Hemlock, Michigan (76 FR 63282...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-11-15
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-74-2013] Subzone 114F, Authorization of Production Activity, Easton-Bell Sports, Inc., (Sports Equipment), Rantoul, Illinois On June 27, 2013, Easton-Bell Sports, Inc. submitted a notification of proposed production activity to the Foreign-Trade Zones...
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Lagrangian averaging with geodesic mean
NASA Astrophysics Data System (ADS)
Oliver, Marcel
2017-11-01
This paper revisits the derivation of the Lagrangian averaged Euler (LAE), or Euler-α equations in the light of an intrinsic definition of the averaged flow map as the geodesic mean on the volume-preserving diffeomorphism group. Under the additional assumption that first-order fluctuations are statistically isotropic and transported by the mean flow as a vector field, averaging of the kinetic energy Lagrangian of an ideal fluid yields the LAE Lagrangian. The derivation presented here assumes a Euclidean spatial domain without boundaries.
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Lagrangian averaging with geodesic mean.
Oliver, Marcel
2017-11-01
This paper revisits the derivation of the Lagrangian averaged Euler (LAE), or Euler- α equations in the light of an intrinsic definition of the averaged flow map as the geodesic mean on the volume-preserving diffeomorphism group. Under the additional assumption that first-order fluctuations are statistically isotropic and transported by the mean flow as a vector field, averaging of the kinetic energy Lagrangian of an ideal fluid yields the LAE Lagrangian. The derivation presented here assumes a Euclidean spatial domain without boundaries.
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-04-08
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-132-2012] Approval of Subzone Status; Pepsi Cola Puerto Rico Distributing, LLC, Toa Baja, Puerto Rico On December 7, 2012, the Executive Secretary... activation limit of FTZ 7, on [[Page 20888
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NASA Astrophysics Data System (ADS)
Gurocak, Zulfu; Yalcin, Erkut
2016-06-01
In this study, the effect of the weathering degree on the excavatability of rock masses was investigated. The ophiolitic rock mass along the route of Komurhan Tunnel was chosen as the case study. Both laboratory and field studies were carried out for this purpose. In the first stage, the ophiolitic rock mass along the tunnel route was classified into three subzones according to the weathering degree and the ophiolitic rock masses of the each subzones were classified using the empirical excavatability classifications proposed by the different researchers. Furthermore, in-situ excavatability classes of rock masses in each zone were determined and the results were compared. The in-situ excavatability class of fresh (Zone-I) and slightly weathered (Zone-II) rock masses was determined as Blasting and that of moderately weathered (Zone-III) rock mass was determined as Very Hard/Very Difficult. As the obtained results were compared, it was found that the weathering degree has a significant effect on the excavatability and that it is more appropriate to prefer empirical classifications in the empirical determination of excavatability classes of rock masses having the same lithology by taking the weathering degree into account.
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Lagrangian derivation of the two coupled field equations in the Janus cosmological model
NASA Astrophysics Data System (ADS)
Petit, Jean-Pierre; D'Agostini, G.
2015-05-01
After a review citing the results obtained in previous articles introducing the Janus Cosmological Model, consisting of a set of two coupled field equations, where one metrics refers to the positive masses and the other to the negative masses, which explains the observed cosmic acceleration and the nature of dark energy, we present the Lagrangian derivation of the model.
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-21
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Docket 43-2011] Foreign-Trade Subzone 38A; Application for Expansion of Manufacturing Authority (Production Capacity); BMW Manufacturing Co., LLC; (Motor Vehicles) A request has been submitted to the Foreign-Trade Zones Board (the Board) by the South Carolina State Ports Authority, grantee of FTZ...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-30
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [S-32-2013] Approval of Subzone Status; Teva Pharmaceuticals USA, Inc.; North Wales, Chalfont, Kutztown and Sellersville, Pennsylvania On March 18, 2013, the... activation limit of FTZ 35, on behalf of Teva Pharmaceuticals USA, Inc., in North Wales, Chalfont, Kutztown...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-03
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1728] Voluntary Termination of Foreign-Trade Subzone 102A, Ford Motor Corporation, Hazelwood, MO Pursuant to the authority granted in the... the Ford Motor Corporation plant in Hazelwood, Missouri (Board Order 252, 49 FR 19541, 5/8/84...
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2010-01-05
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1654] Approval for Expansion of Subzone 22F, Abbott Molecular, Inc. (Pharmaceutical and Molecular Diagnostic Products), Chicago, IL, Area... manufacturing authority on behalf of Abbott Molecular, Inc., within FTZ 22F in Des Plaines and Elk Grove Village...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-07-30
..., Pennsylvania, Application for Subzone, Hardinger Transfer Co., Erie and Grove City, Pennsylvania An application has been submitted to the Foreign-Trade Zones (FTZ) Board by the Erie-Western Pennsylvania Port..., Pennsylvania. The application was submitted pursuant to the provisions of the Foreign- Trade Zones Act, as...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-22
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Docket 2-2010] Foreign-Trade Zone 201--Holyoke, MA; Application for Subzone; Yankee Candle Corporation (Candles and Gift Sets); Whately and South Deerfield, MA An application has been submitted to the Foreign-Trade Zones Board (the Board) by the Holyoke...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-21
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1793] Grant of Authority for Subzone... United States, to expedite and encourage foreign commerce, and for other purposes,'' and authorizes the... benefit and is in the public interest; Whereas, Lincoln Foreign-Trade Zone, Inc, grantee of Foreign-Trade...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-21
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1792] Grant of Authority for Subzone... United States, to expedite and encourage foreign commerce, and for other purposes,'' and authorizes the... significant public benefit and is in the public interest; Whereas, Dane County, grantee of Foreign-Trade Zone...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-15
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-45-2013] Notification of Proposed Production...), operator of Subzone 29J, submitted a notification of proposed production activity to the FTZ Board for its.... Production under FTZ procedures could exempt LLFlex from customs duty payments on the foreign status...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-12-28
...-Trade Zones 140 and 78 Applications for Subzone Authority Dow Corning Corporation, Hemlock Semiconductor Corporation and Hemlock Semiconductor, L.L.C.; Notice of Public Hearing and Extension of Comment Period A... facility in Midland, Michigan (76 FR 63282-63283, 10/12/2011), the Hemlock Semiconductor Corporation...
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A coupled Eulerian/Lagrangian method for the solution of three-dimensional vortical flows
NASA Technical Reports Server (NTRS)
Felici, Helene Marie
1992-01-01
A coupled Eulerian/Lagrangian method is presented for the reduction of numerical diffusion observed in solutions of three-dimensional rotational flows using standard Eulerian finite-volume time-marching procedures. A Lagrangian particle tracking method using particle markers is added to the Eulerian time-marching procedure and provides a correction of the Eulerian solution. In turn, the Eulerian solutions is used to integrate the Lagrangian state-vector along the particles trajectories. The Lagrangian correction technique does not require any a-priori information on the structure or position of the vortical regions. While the Eulerian solution ensures the conservation of mass and sets the pressure field, the particle markers, used as 'accuracy boosters,' take advantage of the accurate convection description of the Lagrangian solution and enhance the vorticity and entropy capturing capabilities of standard Eulerian finite-volume methods. The combined solution procedures is tested in several applications. The convection of a Lamb vortex in a straight channel is used as an unsteady compressible flow preservation test case. The other test cases concern steady incompressible flow calculations and include the preservation of turbulent inlet velocity profile, the swirling flow in a pipe, and the constant stagnation pressure flow and secondary flow calculations in bends. The last application deals with the external flow past a wing with emphasis on the trailing vortex solution. The improvement due to the addition of the Lagrangian correction technique is measured by comparison with analytical solutions when available or with Eulerian solutions on finer grids. The use of the combined Eulerian/Lagrangian scheme results in substantially lower grid resolution requirements than the standard Eulerian scheme for a given solution accuracy.
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2013-10-28
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-89-2013] Foreign-Trade Zone 3--San Francisco, California; Application for Subzone; Phillips 66 Company; Rodeo, California An application has been submitted to the Foreign-Trade Zones (FTZ) Board by the City and County of San Francisco, grantee of FTZ 3...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-12-23
... Application for Expansion; Mercury Marine (Marine Propulsion Products), Fond du Lac and Oshkosh, WI An... of FTZ 41, on behalf of Mercury Marine, operator of Subzone 41H at Mercury Marine's marine propulsion... manufacturing of marine propulsion products at Mercury Marine's facilities located in Fond du Lac and Oshkosh...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-10-04
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1859] Grant of Authority for Subzone... expedite and encourage foreign commerce, and for other purposes,'' and authorizes the Foreign-Trade Zones... benefit and is in the public interest; Whereas, the City of San Jose, California, grantee of Foreign-Trade...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-20
... Manufacturing Authority; Foreign-Trade Subzone 33E; DNP IMS America Corporation (Thermal Transfer Ribbon Printer..., grantee of FTZ 33, has requested an expansion of the scope of manufacturing authority on behalf of DNP IMS... scope of manufacturing authority under zone procedures to include activity related to thermal transfer...
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Matter Lagrangian of particles and fluids
NASA Astrophysics Data System (ADS)
Avelino, P. P.; Sousa, L.
2018-03-01
We consider a model where particles are described as localized concentrations of energy, with fixed rest mass and structure, which are not significantly affected by their self-induced gravitational field. We show that the volume average of the on-shell matter Lagrangian Lm describing such particles, in the proper frame, is equal to the volume average of the trace T of the energy-momentum tensor in the same frame, independently of the particle's structure and constitution. Since both Lm and T are scalars, and thus independent of the reference frame, this result is also applicable to collections of moving particles and, in particular, to those which can be described by a perfect fluid. Our results are expected to be particularly relevant in the case of modified theories of gravity with nonminimal coupling to matter where the matter Lagrangian appears explicitly in the equations of motion of the gravitational and matter fields, such as f (R ,Lm) and f (R ,T ) gravity. In particular, they indicate that, in this context, f (R ,Lm) theories may be regarded as a subclass of f (R ,T ) gravity.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-17
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [T-2-2009] Foreign-Trade Zone Subzone 33E--Mount Pleasant, PA; Temporary/ Interim Manufacturing Authority; DNP IMS America Corporation (Thermal Transfer...) authority, on behalf of DNP IMS America Corporation to manufacture thermal transfer ribbon printer rolls...
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2011-02-24
... Status; Vestas Nacelles America, Inc. (Wind Turbine Nacelles, Hubs, Blades and Towers), Brighton, Denver...-purpose subzone at the wind turbine nacelle, hub, blade and tower manufacturing and warehousing facilities... status for activity related to the manufacturing and warehousing of wind turbine nacelles, hubs, blades...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-10
...-81u), and the regulations of the Board (15 CFR part 400). It was formally filed on February 4, 2010. Subzone 33E (123 employees, 360 million square meters coating capacity) currently has authority for the... the production of monochrome TTR printer rolls (some 336 million square meters capacity), using...
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2012-12-10
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1871] Approval for Expansion of Manufacturing Authority; Foreign-Trade Subzone 41H; Mercury Marine (Marine Propulsion Products); Fond du Lac and Oshkosh, WI Pursuant to its authority under the Foreign-Trade Zones Act of June 18, 1934, as amended (19 U...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-09
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-76-2013] Subzones 247A and 247B, Authorization of Production Activity, GE Transportation, (Locomotives, Off-Highway Vehicles and Motors/Engines), Lawrence Park and Grove City, Pennsylvania On July 18, 2013, GE Transportation submitted a notification of proposed production activity to the Foreig...
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Lagrangian postprocessing of computational hemodynamics.
Shadden, Shawn C; Arzani, Amirhossein
2015-01-01
Recent advances in imaging, modeling, and computing have rapidly expanded our capabilities to model hemodynamics in the large vessels (heart, arteries, and veins). This data encodes a wealth of information that is often under-utilized. Modeling (and measuring) blood flow in the large vessels typically amounts to solving for the time-varying velocity field in a region of interest. Flow in the heart and larger arteries is often complex, and velocity field data provides a starting point for investigating the hemodynamics. This data can be used to perform Lagrangian particle tracking, and other Lagrangian-based postprocessing. As described herein, Lagrangian methods are necessary to understand inherently transient hemodynamic conditions from the fluid mechanics perspective, and to properly understand the biomechanical factors that lead to acute and gradual changes of vascular function and health. The goal of the present paper is to review Lagrangian methods that have been used in post-processing velocity data of cardiovascular flows.
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Lagrangian postprocessing of computational hemodynamics
Shadden, Shawn C.; Arzani, Amirhossein
2014-01-01
Recent advances in imaging, modeling and computing have rapidly expanded our capabilities to model hemodynamics in the large vessels (heart, arteries and veins). This data encodes a wealth of information that is often under-utilized. Modeling (and measuring) blood flow in the large vessels typically amounts to solving for the time-varying velocity field in a region of interest. Flow in the heart and larger arteries is often complex, and velocity field data provides a starting point for investigating the hemodynamics. This data can be used to perform Lagrangian particle tracking, and other Lagrangian-based postprocessing. As described herein, Lagrangian methods are necessary to understand inherently transient hemodynamic conditions from the fluid mechanics perspective, and to properly understand the biomechanical factors that lead to acute and gradual changes of vascular function and health. The goal of the present paper is to review Lagrangian methods that have been used in post-processing velocity data of cardiovascular flows. PMID:25059889
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Forecasting Future Sea Ice Conditions: A Lagrangian Approach
2015-09-30
1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Forecasting Future Sea Ice Conditions: A Lagrangian ...GCMs participating in IPCC AR5 agree with observed source region patterns from the satellite- derived dataset. 4- Compare Lagrangian ice... Lagrangian sea-ice back trajectories to estimate thermodynamic and dynamic (advection) ice loss. APPROACH We use a Lagrangian trajectory model to
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-07-01
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-65-2013] Notification of Proposed Production Activity; Subzone 7G; Schering-Plough Products, L.L.C. (Pharmaceutical Products); Las Piedras, Puerto Rico... proposed production activity to the FTZ Board for its facility in Las Piedras, Puerto Rico. The...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-09-28
... County, Florida; Extension of Subzone; Aso LLC (Adhesive Bandage Manufacturing); Sarasota County, FL An... for the manufacture of adhesive bandages under FTZ procedures (Board Order 1120, 65 FR 58508-58509, 9... used various duty suspension provisions on adhesive tape. Aso is now requesting to indefinitely extend...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-28
... Status; Yankee Candle Corporation (Candles and Gift Sets); Whately and South Deerfield, MA Pursuant to... special-purpose subzone at the candle and gift set manufacturing and distribution facilities of Yankee... activity related to the manufacturing and distribution of candles and gift sets at the facilities of Yankee...
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Option volatility and the acceleration Lagrangian
NASA Astrophysics Data System (ADS)
Baaquie, Belal E.; Cao, Yang
2014-01-01
This paper develops a volatility formula for option on an asset from an acceleration Lagrangian model and the formula is calibrated with market data. The Black-Scholes model is a simpler case that has a velocity dependent Lagrangian. The acceleration Lagrangian is defined, and the classical solution of the system in Euclidean time is solved by choosing proper boundary conditions. The conditional probability distribution of final position given the initial position is obtained from the transition amplitude. The volatility is the standard deviation of the conditional probability distribution. Using the conditional probability and the path integral method, the martingale condition is applied, and one of the parameters in the Lagrangian is fixed. The call option price is obtained using the conditional probability and the path integral method.
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Stochastic modeling of Lagrangian accelerations
NASA Astrophysics Data System (ADS)
Reynolds, Andy
2002-11-01
It is shown how Sawford's second-order Lagrangian stochastic model (Phys. Fluids A 3, 1577-1586, 1991) for fluid-particle accelerations can be combined with a model for the evolution of the dissipation rate (Pope and Chen, Phys. Fluids A 2, 1437-1449, 1990) to produce a Lagrangian stochastic model that is consistent with both the measured distribution of Lagrangian accelerations (La Porta et al., Nature 409, 1017-1019, 2001) and Kolmogorov's similarity theory. The later condition is found not to be satisfied when a constant dissipation rate is employed and consistency with prescribed acceleration statistics is enforced through fulfilment of a well-mixed condition.
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Chiral anomalies and effective vector meson Lagrangian beyond the tree level
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dominguez, C.A.
1987-12-01
The decays ..pi../sup O/ ..-->.. ..gamma gamma.., rho ..-->.. ..pi gamma.., ..omega.. ..-->.. ..pi gamma.., ..omega.. ..-->.. 3..pi.. and ..gamma.. ..-->.. 3..pi.. are studied in the framework of the chiral invariant effective Vector Meson Lagrangian beyond the tree level. The standard Lagrangian is enlarged by including an infinite number of radial excitations which are summed according to the dual model. As a result tree level diagrams are modified by a universal form factor at each vertex containing off-mass-shell mesons, but still respecting chiral anomaly low energy theorems. These vertex corrections bring the tree level predictions into better agreement with experiment.more » The presence of the ..omega.. ..-->.. 3..pi.. contact term is confirmed but its strength is considerably smaller than at tree level.« less
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2010-09-17
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Chiral Lagrangian with Heavy Quark-Diquark Symmetry
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jie Hu; Thomas Mehen
2005-11-29
We construct a chiral Lagrangian for doubly heavy baryons and heavy mesons that is invariant under heavy quark-diquark symmetry at leading order and includes the leading O(1/m{sub Q}) symmetry violating operators. The theory is used to predict the electromagnetic decay width of the J=3/2 member of the ground state doubly heavy baryon doublet. Numerical estimates are provided for doubly charm baryons. We also calculate chiral corrections to doubly heavy baryon masses and strong decay widths of low lying excited doubly heavy baryons.
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2013-05-16
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2013-04-09
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2013-04-09
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2011-11-25
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2010-04-07
... use FTZ procedures for their operations, the structure of many existing U.S. steel plants could make...; Application for Subzone Authority; ThyssenKrupp Steel and Stainless USA, LLC; Invitation for Public Comment on...Krupp Steel and Stainless USA, LLC (ThyssenKrupp) facility in Calvert, Alabama. The staff's preliminary...
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2011-12-27
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Coherent Lagrangian swirls among submesoscale motions.
Beron-Vera, F J; Hadjighasem, A; Xia, Q; Olascoaga, M J; Haller, G
2018-03-05
The emergence of coherent Lagrangian swirls (CLSs) among submesoscale motions in the ocean is illustrated. This is done by applying recent nonlinear dynamics tools for Lagrangian coherence detection on a surface flow realization produced by a data-assimilative submesoscale-permitting ocean general circulation model simulation of the Gulf of Mexico. Both mesoscale and submesoscale CLSs are extracted. These extractions prove the relevance of coherent Lagrangian eddies detected in satellite-altimetry-based geostrophic flow data for the arguably more realistic ageostrophic multiscale flow.
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NASA Astrophysics Data System (ADS)
Avelino, P. P.; Azevedo, R. P. L.
2018-03-01
In this paper we show that the on-shell Lagrangian of a perfect fluid depends on microscopic properties of the fluid, giving specific examples of perfect fluids with different on-shell Lagrangians but with the same energy-momentum tensor. We demonstrate that if the fluid is constituted by localized concentrations of energy with fixed rest mass and structure (solitons) then the average on-shell Lagrangian of a perfect fluid is given by Lm=T , where T is the trace of the energy-momentum tensor. We show that our results have profound implications for theories of gravity where the matter Lagrangian appears explicitly in the equations of motion of the gravitational and matter fields, potentially leading to observable deviations from a nearly perfect cosmic microwave background black body spectrum: n -type spectral distortions, affecting the normalization of the spectral energy density. Finally, we put stringent constraints on f (R ,Lm) theories of gravity using the COBE-FIRAS measurement of the spectral radiance of the cosmic microwave background.
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Alternative kinetic energy metrics for Lagrangian systems
NASA Astrophysics Data System (ADS)
Sarlet, W.; Prince, G.
2010-11-01
We examine Lagrangian systems on \\ {R}^n with standard kinetic energy terms for the possibility of additional, alternative Lagrangians with kinetic energy metrics different to the Euclidean one. Using the techniques of the inverse problem in the calculus of variations we find necessary and sufficient conditions for the existence of such Lagrangians. We illustrate the problem in two and three dimensions with quadratic and cubic potentials. As an aside we show that the well-known anomalous Lagrangians for the Coulomb problem can be removed by switching on a magnetic field, providing an appealing resolution of the ambiguous quantizations of the hydrogen atom.
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Lagrangian flows within reflecting internal waves at a horizontal free-slip surface
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhou, Qi, E-mail: q.zhou@damtp.cam.ac.uk; Diamessis, Peter J.
In this paper sequel to Zhou and Diamessis [“Reflection of an internal gravity wave beam off a horizontal free-slip surface,” Phys. Fluids 25, 036601 (2013)], we consider Lagrangian flows within nonlinear internal waves (IWs) reflecting off a horizontal free-slip rigid lid, the latter being a model of the ocean surface. The problem is approached both analytically using small-amplitude approximations and numerically by tracking Lagrangian fluid particles in direct numerical simulation (DNS) datasets of the Eulerian flow. Inviscid small-amplitude analyses for both plane IWs and IW beams (IWBs) show that Eulerian mean flow due to wave-wave interaction and wave-induced Stokes driftmore » cancels each other out completely at the second order in wave steepness A, i.e., O(A{sup 2}), implying zero Lagrangian mean flow up to that order. However, high-accuracy particle tracking in finite-Reynolds-number fully nonlinear DNS datasets from the work of Zhou and Diamessis suggests that the Euler-Stokes cancelation on O(A{sup 2}) is not complete. This partial cancelation significantly weakens the mean Lagrangian flows but does not entirely eliminate them. As a result, reflecting nonlinear IWBs produce mean Lagrangian drifts on O(A{sup 2}) and thus particle dispersion on O(A{sup 4}). The above findings can be relevant to predicting IW-driven mass transport in the oceanic surface and subsurface region which bears important observational and environmental implications, under circumstances where the effect of Earth rotation can be ignored.« less
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-17
...-purpose subzone status for the upholstered furniture manufacturing facilities of Max Home, LLC (Max Home... additional manufacturing plant and warehouse (100 employees/ 26 acres/160,000 sq. ft.) are located at 1313... finished upholstered furniture (chairs, seats, sofas, sleep sofas, and sectionals). The additional...
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Multi-Lagrangians for integrable systems
NASA Astrophysics Data System (ADS)
Nutku, Y.; Pavlov, M. V.
2002-03-01
We propose a general scheme to construct multiple Lagrangians for completely integrable nonlinear evolution equations that admit multi-Hamiltonian structure. The recursion operator plays a fundamental role in this construction. We use a conserved quantity higher/lower than the Hamiltonian in the potential part of the new Lagrangian and determine the corresponding kinetic terms by generating the appropriate momentum map. This leads to some remarkable new developments. We show that nonlinear evolutionary systems that admit N-fold first order local Hamiltonian structure can be cast into variational form with 2N-1 Lagrangians which will be local functionals of Clebsch potentials. This number increases to 3N-2 when the Miura transformation is invertible. Furthermore we construct a new Lagrangian for polytropic gas dynamics in 1+1 dimensions which is a free, local functional of the physical field variables, namely density and velocity, thus dispensing with the necessity of introducing Clebsch potentials entirely. This is a consequence of bi-Hamiltonian structure with a compatible pair of first and third order Hamiltonian operators derived from Sheftel's recursion operator.
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NASA Technical Reports Server (NTRS)
Liou, Meng-Sing
1992-01-01
A unique formulation of describing fluid motion is presented. The method, referred to as 'extended Lagrangian method', is interesting from both theoretical and numerical points of view. The formulation offers accuracy in numerical solution by avoiding numerical diffusion resulting from mixing of fluxes in the Eulerian description. Meanwhile, it also avoids the inaccuracy incurred due to geometry and variable interpolations used by the previous Lagrangian methods. Unlike the Lagrangian method previously imposed which is valid only for supersonic flows, the present method is general and capable of treating subsonic flows as well as supersonic flows. The method proposed in this paper is robust and stable. It automatically adapts to flow features without resorting to clustering, thereby maintaining rather uniform grid spacing throughout and large time step. Moreover, the method is shown to resolve multi-dimensional discontinuities with a high level of accuracy, similar to that found in one-dimensional problems.
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-19
... Polyacrylonitrile Fiber and Carbon Fiber), Rockwood, TN Pursuant to its authority under the Foreign-Trade Zones Act...-purpose subzone at the oxidized polyacrylonitrile fiber (OPF) and carbon fiber manufacturing and... manufacture 24K or higher tow, standard grade carbon fiber for export; and Whereas, at this time, the Board is...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-04-18
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-92-2012] Authorization of Production Activity, Foreign-Trade Subzone 26L, Suzuki Mfg. of America Corp. (All-Terrain Vehicles), Rome, Jonesboro and Cartersville, Georgia On November 19, 2012, Georgia Foreign-Trade Zone, Inc., grantee of FTZ 26, submitted a notification of proposed production...
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Alternative Transfer to the Earth-Moon Lagrangian Points L4 and L5 Using Lunar Gravity assist
NASA Astrophysics Data System (ADS)
Salazar, Francisco; Winter, Othon; Macau, Elbert; Bertachini de Almeida Prado, Antonio Fernando
2012-07-01
Lagrangian points L4 and L5 lie at 60 degrees ahead of and behind Moon in its orbit with respect to the Earth. Each one of them is a third point of an equilateral triangle with the base of the line defined by those two bodies. These Lagrangian points are stable for the Earth-Moon mass ratio. Because of their distance electromagnetic radiations from the Earth arrive on them substantially attenuated. As so, these Lagrangian points represent remarkable positions to host astronomical observatories. However, this same distance characteristic may be a challenge for periodic servicing mission. This paper studies transfer orbits in the planar restricted three-body problem. To avoid solving a two-boundary problem, the patched-conic approximation is used to find initial conditions to transfer a spacecraft between an Earth circular parking orbit and the Lagrangian points L4, L5 (in the Earth-Moon system), such that a swing-by maneuver is applied using the lunar gravity. We also found orbits that can be used to make a tour to the Lagrangian points L4, L5 based on the theorem of image trajectories. Keywords: Stable Lagrangian points, L4, L5, Three-Body problem, Patched Conic, Swing-by
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Target Lagrangian kinematic simulation for particle-laden flows.
Murray, S; Lightstone, M F; Tullis, S
2016-09-01
The target Lagrangian kinematic simulation method was motivated as a stochastic Lagrangian particle model that better synthesizes turbulence structure, relative to stochastic separated flow models. By this method, the trajectories of particles are constructed according to synthetic turbulent-like fields, which conform to a target Lagrangian integral timescale. In addition to recovering the expected Lagrangian properties of fluid tracers, this method is shown to reproduce the crossing trajectories and continuity effects, in agreement with an experimental benchmark.
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-26
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Docket 57-2010] Foreign-Trade Zone 148--Knoxville, Tennessee, Toho Tenax America, Inc., Subzone 148C (Carbon Fiber Manufacturing Authority... manufacture carbon fiber for the U.S. market at this time, is being extended to February 11, 2013, to allow...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-08
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Docket 43-2011] Foreign-Trade Subzone 38A; Termination of Review of Application for Expansion; BMW Manufacturing Co., LLC (Motor Vehicles); Greer, South Carolina Notice is hereby given of termination of review of an application submitted by the South Carolina State Ports Authority, grantee of FTZ...
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2010-05-27
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Docket 36-2010] Foreign-Trade Zone 18--San Jose... Board) by the City of San Jose, grantee of FTZ 18, requesting special-purpose subzone status for the... formally filed on May 18, 2010. The Lam facilities (1,483 employees, 1,020 systems per year capacity...
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Fingerprints of heavy scales in electroweak effective Lagrangians
NASA Astrophysics Data System (ADS)
Pich, Antonio; Rosell, Ignasi; Santos, Joaquín; Sanz-Cillero, Juan José
2017-04-01
The couplings of the electroweak effective theory contain information on the heavy-mass scales which are no-longer present in the low-energy Lagrangian. We build a general effective Lagrangian, implementing the electroweak chiral symmetry breaking SU(2) L ⊗ SU(2) R → SU(2) L+ R , which couples the known particle fields to heavier states with bosonic quantum numbers J P = 0± and 1±. We consider colour-singlet heavy fields that are in singlet or triplet representations of the electroweak group. Integrating out these heavy scales, we analyze the pattern of low-energy couplings among the light fields which are generated by the massive states. We adopt a generic non-linear realization of the electroweak symmetry breaking with a singlet Higgs, without making any assumption about its possible doublet structure. Special attention is given to the different possible descriptions of massive spin-1 fields and the differences arising from naive implementations of these formalisms, showing their full equivalence once a proper short-distance behaviour is required.
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Communication: A simplified coupled-cluster Lagrangian for polarizable embedding.
Krause, Katharina; Klopper, Wim
2016-01-28
A simplified coupled-cluster Lagrangian, which is linear in the Lagrangian multipliers, is proposed for the coupled-cluster treatment of a quantum mechanical system in a polarizable environment. In the simplified approach, the amplitude equations are decoupled from the Lagrangian multipliers and the energy obtained from the projected coupled-cluster equation corresponds to a stationary point of the Lagrangian.
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Communication: A simplified coupled-cluster Lagrangian for polarizable embedding
DOE Office of Scientific and Technical Information (OSTI.GOV)
Krause, Katharina; Klopper, Wim, E-mail: klopper@kit.edu
A simplified coupled-cluster Lagrangian, which is linear in the Lagrangian multipliers, is proposed for the coupled-cluster treatment of a quantum mechanical system in a polarizable environment. In the simplified approach, the amplitude equations are decoupled from the Lagrangian multipliers and the energy obtained from the projected coupled-cluster equation corresponds to a stationary point of the Lagrangian.
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A Chiang-type lagrangian in CP^2
NASA Astrophysics Data System (ADS)
Cannas da Silva, Ana
2018-03-01
We analyse a monotone lagrangian in CP^2 that is hamiltonian isotopic to the standard lagrangian RP^2, yet exhibits a distinguishing behaviour under reduction by one of the toric circle actions, namely it intersects transversally the reduction level set and it projects one-to-one onto a great circle in CP^1. This lagrangian thus provides an example of embedded composition fitting work of Wehrheim-Woodward and Weinstein.
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2013-05-23
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2010-04-13
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2012-12-10
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2012-06-01
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Special Bohr-Sommerfeld Lagrangian submanifolds
NASA Astrophysics Data System (ADS)
Tyurin, N. A.
2016-12-01
We introduce a new notion in symplectic geometry, that of speciality for Lagrangian submanifolds satisfying the Bohr- Sommerfeld condition. We show that it enables one to construct finite-dimensional moduli spaces of special Bohr- Sommerfeld Lagrangian submanifolds with respect to any ample line bundle on an algebraic variety with a Hodge metric regarded as the symplectic form. This construction can be used to study mirror symmetry.
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Computing eddy-driven effective diffusivity using Lagrangian particles
Wolfram, Phillip J.; Ringler, Todd D.
2017-08-14
A novel method to derive effective diffusivity from Lagrangian particle trajectory data sets is developed and then analyzed relative to particle-derived meridional diffusivity for eddy-driven mixing in an idealized circumpolar current. Quantitative standard dispersion- and transport-based mixing diagnostics are defined, compared and contrasted to motivate the computation and use of effective diffusivity derived from Lagrangian particles. We compute the effective diffusivity by first performing scalar transport on Lagrangian control areas using stored trajectories computed from online Lagrangian In-situ Global High-performance particle Tracking (LIGHT) using the Model for Prediction Across Scales Ocean (MPAS-O). Furthermore, the Lagrangian scalar transport scheme is comparedmore » against an Eulerian scalar transport scheme. Spatially-variable effective diffusivities are computed from resulting time-varying cumulative concentrations that vary as a function of cumulative area. The transport-based Eulerian and Lagrangian effective diffusivity diagnostics are found to be qualitatively consistent with the dispersion-based diffusivity. All diffusivity estimates show a region of increased subsurface diffusivity within the core of an idealized circumpolar current and results are within a factor of two of each other. The Eulerian and Lagrangian effective diffusivities are most similar; smaller and more spatially diffused values are obtained with the dispersion-based diffusivity computed with particle clusters.« less
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Computing eddy-driven effective diffusivity using Lagrangian particles
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wolfram, Phillip J.; Ringler, Todd D.
A novel method to derive effective diffusivity from Lagrangian particle trajectory data sets is developed and then analyzed relative to particle-derived meridional diffusivity for eddy-driven mixing in an idealized circumpolar current. Quantitative standard dispersion- and transport-based mixing diagnostics are defined, compared and contrasted to motivate the computation and use of effective diffusivity derived from Lagrangian particles. We compute the effective diffusivity by first performing scalar transport on Lagrangian control areas using stored trajectories computed from online Lagrangian In-situ Global High-performance particle Tracking (LIGHT) using the Model for Prediction Across Scales Ocean (MPAS-O). Furthermore, the Lagrangian scalar transport scheme is comparedmore » against an Eulerian scalar transport scheme. Spatially-variable effective diffusivities are computed from resulting time-varying cumulative concentrations that vary as a function of cumulative area. The transport-based Eulerian and Lagrangian effective diffusivity diagnostics are found to be qualitatively consistent with the dispersion-based diffusivity. All diffusivity estimates show a region of increased subsurface diffusivity within the core of an idealized circumpolar current and results are within a factor of two of each other. The Eulerian and Lagrangian effective diffusivities are most similar; smaller and more spatially diffused values are obtained with the dispersion-based diffusivity computed with particle clusters.« less
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Shear and shearless Lagrangian structures in compound channels
NASA Astrophysics Data System (ADS)
Enrile, F.; Besio, G.; Stocchino, A.
2018-03-01
Transport processes in a physical model of a natural stream with a composite cross-section (compound channel) are investigated by means of a Lagrangian analysis based on nonlinear dynamical system theory. Two-dimensional free surface Eulerian experimental velocity fields of a uniform flow in a compound channel form the basis for the identification of the so-called Lagrangian Coherent Structures. Lagrangian structures are recognized as the key features that govern particle trajectories. We seek for two particular class of Lagrangian structures: Shear and shearless structures. The former are generated whenever the shear dominates the flow whereas the latter behave as jet-cores. These two type of structures are detected as ridges and trenches of the Finite-Time Lyapunov Exponents fields, respectively. Besides, shearlines computed applying the geodesic theory of transport barriers mark Shear Lagrangian Coherent Structures. So far, the detection of these structures in real experimental flows has not been deeply investigated. Indeed, the present results obtained in a wide range of the controlling parameters clearly show a different behaviour depending on the shallowness of the flow. Shear and Shearless Lagrangian Structures detected from laboratory experiments clearly appear as the flow develops in shallow conditions. The presence of these Lagrangian Structures tends to fade in deep flow conditions.
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NASA Astrophysics Data System (ADS)
Huhn, Florian; Haller, George
2014-05-01
Haller and Beron-Vera(2013) have recently introduced a new objective method to detect coherent Lagrangian eddies in turbulence. They find that closed null-geodesics of a generalized Green-Lagrange strain tensor act as coherent Lagrangian eddy boundaries, showing near-zero and uniform material stretching. We make use of this method to develop an automated detection procedure for coherent Lagrangian eddies in large-scale ocean data. We apply our results to a recent 3D general circulation model, the Southern Ocean State Estimate (SOSE), with focus on the South Atlantic Ocean and the inter-ocean exchange between the Indian and Atlantic ocean. We detect a large number of coherent Lagrangian eddies and present statistics of their properties. The largest and most circular eddy boundaries represent Lagrangian Agulhas rings. Circular regions inside these rings with higher temperature and salinity than the surrounding waters can be explained by the coherent eddy boundaries that enclose and isolate the eddy interiors. We compare eddy boundaries at different depths with eddy boundaries obtained from geostrophic velocities derived from the model's sea surface height (SSH). The transport of mass, heat and salinity enclosed by coherent eddies through a section in the Cape basin is quantified and compared to the non-coherent transport by the background flow.
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-09-27
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-53-2013] Subzone 9F, Authorization of Production Activity, The Gas Company, LLC dba Hawai'i Gas, (Synthetic Natural Gas), Kapolei, Hawaii On May 22, 2013, The Gas Company, LLC dba Hawai'i Gas submitted a notification of proposed production activity to...
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NASA Astrophysics Data System (ADS)
Verma, Aman; Mahesh, Krishnan
2012-08-01
The dynamic Lagrangian averaging approach for the dynamic Smagorinsky model for large eddy simulation is extended to an unstructured grid framework and applied to complex flows. The Lagrangian time scale is dynamically computed from the solution and does not need any adjustable parameter. The time scale used in the standard Lagrangian model contains an adjustable parameter θ. The dynamic time scale is computed based on a "surrogate-correlation" of the Germano-identity error (GIE). Also, a simple material derivative relation is used to approximate GIE at different events along a pathline instead of Lagrangian tracking or multi-linear interpolation. Previously, the time scale for homogeneous flows was computed by averaging along directions of homogeneity. The present work proposes modifications for inhomogeneous flows. This development allows the Lagrangian averaged dynamic model to be applied to inhomogeneous flows without any adjustable parameter. The proposed model is applied to LES of turbulent channel flow on unstructured zonal grids at various Reynolds numbers. Improvement is observed when compared to other averaging procedures for the dynamic Smagorinsky model, especially at coarse resolutions. The model is also applied to flow over a cylinder at two Reynolds numbers and good agreement with previous computations and experiments is obtained. Noticeable improvement is obtained using the proposed model over the standard Lagrangian model. The improvement is attributed to a physically consistent Lagrangian time scale. The model also shows good performance when applied to flow past a marine propeller in an off-design condition; it regularizes the eddy viscosity and adjusts locally to the dominant flow features.
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Effective Lagrangians and Current Algebra in Three Dimensions
NASA Astrophysics Data System (ADS)
Ferretti, Gabriele
In this thesis we study three dimensional field theories that arise as effective Lagrangians of quantum chromodynamics in Minkowski space with signature (2,1) (QCD3). In the first chapter, we explain the method of effective Langrangians and the relevance of current algebra techniques to field theory. We also provide the physical motivations for the study of QCD3 as a toy model for confinement and as a theory of quantum antiferromagnets (QAF). In chapter two, we derive the relevant effective Lagrangian by studying the low energy behavior of QCD3, paying particular attention to how the global symmetries are realized at the quantum level. In chapter three, we show how baryons arise as topological solitons of the effective Lagrangian and also show that their statistics depends on the number of colors as predicted by the quark model. We calculate mass splitting and magnetic moments of the soliton and find logarithmic corrections to the naive quark model predictions. In chapter four, we drive the current algebra of the theory. We find that the current algebra is a co -homologically non-trivial generalization of Kac-Moody algebras to three dimensions. This fact may provide a new, non -perturbative way to quantize the theory. In chapter five, we discuss the renormalizability of the model in the large-N expansion. We prove the validity of the non-renormalization theorem and compute the critical exponents in a specific limiting case, the CP^ {N-1} model with a Chern-Simons term. Finally, chapter six contains some brief concluding remarks.
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Parallel computing using a Lagrangian formulation
NASA Technical Reports Server (NTRS)
Liou, May-Fun; Loh, Ching Yuen
1991-01-01
A new Lagrangian formulation of the Euler equation is adopted for the calculation of 2-D supersonic steady flow. The Lagrangian formulation represents the inherent parallelism of the flow field better than the common Eulerian formulation and offers a competitive alternative on parallel computers. The implementation of the Lagrangian formulation on the Thinking Machines Corporation CM-2 Computer is described. The program uses a finite volume, first-order Godunov scheme and exhibits high accuracy in dealing with multidimensional discontinuities (slip-line and shock). By using this formulation, a better than six times speed-up was achieved on a 8192-processor CM-2 over a single processor of a CRAY-2.
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Parallel computing using a Lagrangian formulation
NASA Technical Reports Server (NTRS)
Liou, May-Fun; Loh, Ching-Yuen
1992-01-01
This paper adopts a new Lagrangian formulation of the Euler equation for the calculation of two dimensional supersonic steady flow. The Lagrangian formulation represents the inherent parallelism of the flow field better than the common Eulerian formulation and offers a competitive alternative on parallel computers. The implementation of the Lagrangian formulation on the Thinking Machines Corporation CM-2 Computer is described. The program uses a finite volume, first-order Godunov scheme and exhibits high accuracy in dealing with multidimensional discontinuities (slip-line and shock). By using this formulation, we have achieved better than six times speed-up on a 8192-processor CM-2 over a single processor of a CRAY-2.
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NASA Astrophysics Data System (ADS)
Salibindla, Ashwanth; Masuk, Ashik Ullah Mohammad; Ni, Rui
2017-11-01
We have designed and constructed a new vertical water tunnel, V-ONSET, to investigate interfacial mass, momentum and energy transfer between two phases in a Lagrangian frame. This system features an independent control of mean flow and turbulence level. The mean flow opposes the rising/falling velocity of the second phase, ``suspending'' the particles and increasing tracking time in the view area. Strong turbulence is generated by shooting 88 digitally-controlled water jets into the test section. The second phase, either bubbles or oil droplets, can be introduced into the test section through a capillary island. In addition to this flow control system, V-ONSET comes with a 3D two-phase visualization system, consisting of high-speed cameras, two-colored LED system, and in-house Lagrangian particle tracking algorithm. This enables us to acquire the Lagrangian evolution of both phases and the interfacial transfer dynamics in between, paving the way for new closure models for two-phase simulations. Financial support for this project was provided by National Science Foundation under Grant Number: 1653389 and 1705246.
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Healy, R.W.; Russell, T.F.
1993-01-01
A new mass-conservative method for solution of the one-dimensional advection-dispersion equation is derived and discussed. Test results demonstrate that the finite-volume Eulerian-Lagrangian localized adjoint method (FVELLAM) outperforms standard finite-difference methods, in terms of accuracy and efficiency, for solute transport problems that are dominated by advection. For dispersion-dominated problems, the performance of the method is similar to that of standard methods. Like previous ELLAM formulations, FVELLAM systematically conserves mass globally with all types of boundary conditions. FVELLAM differs from other ELLAM approaches in that integrated finite differences, instead of finite elements, are used to approximate the governing equation. This approach, in conjunction with a forward tracking scheme, greatly facilitates mass conservation. The mass storage integral is numerically evaluated at the current time level, and quadrature points are then tracked forward in time to the next level. Forward tracking permits straightforward treatment of inflow boundaries, thus avoiding the inherent problem in backtracking, as used by most characteristic methods, of characteristic lines intersecting inflow boundaries. FVELLAM extends previous ELLAM results by obtaining mass conservation locally on Lagrangian space-time elements. Details of the integration, tracking, and boundary algorithms are presented. Test results are given for problems in Cartesian and radial coordinates.
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-24
... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1821] Voluntary Termination of Foreign-Trade Subzone 9D, Maui Pineapple Company, Ltd., Kahului, Maui, HI Pursuant to its authority under the Foreign-Trade Zones Act of June 18, 1934, as amended (19 U.S.C. 81a-81u), and the Foreign-Trade Zones...
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Lagrangian motion, coherent structures, and lines of persistent material strain.
Samelson, R M
2013-01-01
Lagrangian motion in geophysical fluids may be strongly influenced by coherent structures that support distinct regimes in a given flow. The problems of identifying and demarcating Lagrangian regime boundaries associated with dynamical coherent structures in a given velocity field can be studied using approaches originally developed in the context of the abstract geometric theory of ordinary differential equations. An essential insight is that when coherent structures exist in a flow, Lagrangian regime boundaries may often be indicated as material curves on which the Lagrangian-mean principal-axis strain is large. This insight is the foundation of many numerical techniques for identifying such features in complex observed or numerically simulated ocean flows. The basic theoretical ideas are illustrated with a simple, kinematic traveling-wave model. The corresponding numerical algorithms for identifying candidate Lagrangian regime boundaries and lines of principal Lagrangian strain (also called Lagrangian coherent structures) are divided into parcel and bundle schemes; the latter include the finite-time and finite-size Lyapunov exponent/Lagrangian strain (FTLE/FTLS and FSLE/FSLS) metrics. Some aspects and results of oceanographic studies based on these approaches are reviewed, and the results are discussed in the context of oceanographic observations of dynamical coherent structures.
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NASA Astrophysics Data System (ADS)
Kronsteiner, J.; Horwatitsch, D.; Zeman, K.
2017-10-01
Thermo-mechanical numerical modelling and simulation of extrusion processes faces several serious challenges. Large plastic deformations in combination with a strong coupling of thermal with mechanical effects leads to a high numerical demand for the solution as well as for the handling of mesh distortions. The two numerical methods presented in this paper also reflect two different ways to deal with mesh distortions. Lagrangian Finite Element Methods (FEM) tackle distorted elements by building a new mesh (called re-meshing) whereas Arbitrary Lagrangian Eulerian (ALE) methods use an "advection" step to remap the solution from the distorted to the undistorted mesh. Another difference between conventional Lagrangian and ALE methods is the separate treatment of material and mesh in ALE, allowing the definition of individual velocity fields. In theory, an ALE formulation contains the Eulerian formulation as a subset to the Lagrangian description of the material. The investigations presented in this paper were dealing with the direct extrusion of a tube profile using EN-AW 6082 aluminum alloy and a comparison of experimental with Lagrangian and ALE results. The numerical simulations cover the billet upsetting and last until one third of the billet length is extruded. A good qualitative correlation of experimental and numerical results could be found, however, major differences between Lagrangian and ALE methods concerning thermo-mechanical coupling lead to deviations in the thermal results.
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Gravity, Time, and Lagrangians
NASA Astrophysics Data System (ADS)
Huggins, Elisha
2010-11-01
Feynman mentioned to us that he understood a topic in physics if he could explain it to a college freshman, a high school student, or a dinner guest. Here we will discuss two topics that took us a while to get to that level. One is the relationship between gravity and time. The other is the minus sign that appears in the Lagrangian. (Why would one subtract potential energy from kinetic energy?) In this paper we discuss a thought experiment that relates gravity and time. Then we use a Feynman thought experiment to explain the minus sign in the Lagrangian. Our surprise was that these two topics are related.
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Lagrangian ocean analysis: Fundamentals and practices
van Sebille, Erik; Griffies, Stephen M.; Abernathey, Ryan; ...
2017-11-24
Lagrangian analysis is a powerful way to analyse the output of ocean circulation models and other ocean velocity data such as from altimetry. In the Lagrangian approach, large sets of virtual particles are integrated within the three-dimensional, time-evolving velocity fields. A variety of tools and methods for this purpose have emerged, over several decades. Here, we review the state of the art in the field of Lagrangian analysis of ocean velocity data, starting from a fundamental kinematic framework and with a focus on large-scale open ocean applications. Beyond the use of explicit velocity fields, we consider the influence of unresolvedmore » physics and dynamics on particle trajectories. We comprehensively list and discuss the tools currently available for tracking virtual particles. We then showcase some of the innovative applications of trajectory data, and conclude with some open questions and an outlook. Our overall goal of this review paper is to reconcile some of the different techniques and methods in Lagrangian ocean analysis, while recognising the rich diversity of codes that have and continue to emerge, and the challenges of the coming age of petascale computing.« less
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Lagrangian ocean analysis: Fundamentals and practices
NASA Astrophysics Data System (ADS)
van Sebille, Erik; Griffies, Stephen M.; Abernathey, Ryan; Adams, Thomas P.; Berloff, Pavel; Biastoch, Arne; Blanke, Bruno; Chassignet, Eric P.; Cheng, Yu; Cotter, Colin J.; Deleersnijder, Eric; Döös, Kristofer; Drake, Henri F.; Drijfhout, Sybren; Gary, Stefan F.; Heemink, Arnold W.; Kjellsson, Joakim; Koszalka, Inga Monika; Lange, Michael; Lique, Camille; MacGilchrist, Graeme A.; Marsh, Robert; Mayorga Adame, C. Gabriela; McAdam, Ronan; Nencioli, Francesco; Paris, Claire B.; Piggott, Matthew D.; Polton, Jeff A.; Rühs, Siren; Shah, Syed H. A. M.; Thomas, Matthew D.; Wang, Jinbo; Wolfram, Phillip J.; Zanna, Laure; Zika, Jan D.
2018-01-01
Lagrangian analysis is a powerful way to analyse the output of ocean circulation models and other ocean velocity data such as from altimetry. In the Lagrangian approach, large sets of virtual particles are integrated within the three-dimensional, time-evolving velocity fields. Over several decades, a variety of tools and methods for this purpose have emerged. Here, we review the state of the art in the field of Lagrangian analysis of ocean velocity data, starting from a fundamental kinematic framework and with a focus on large-scale open ocean applications. Beyond the use of explicit velocity fields, we consider the influence of unresolved physics and dynamics on particle trajectories. We comprehensively list and discuss the tools currently available for tracking virtual particles. We then showcase some of the innovative applications of trajectory data, and conclude with some open questions and an outlook. The overall goal of this review paper is to reconcile some of the different techniques and methods in Lagrangian ocean analysis, while recognising the rich diversity of codes that have and continue to emerge, and the challenges of the coming age of petascale computing.
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Lagrangian ocean analysis: Fundamentals and practices
DOE Office of Scientific and Technical Information (OSTI.GOV)
van Sebille, Erik; Griffies, Stephen M.; Abernathey, Ryan
Lagrangian analysis is a powerful way to analyse the output of ocean circulation models and other ocean velocity data such as from altimetry. In the Lagrangian approach, large sets of virtual particles are integrated within the three-dimensional, time-evolving velocity fields. A variety of tools and methods for this purpose have emerged, over several decades. Here, we review the state of the art in the field of Lagrangian analysis of ocean velocity data, starting from a fundamental kinematic framework and with a focus on large-scale open ocean applications. Beyond the use of explicit velocity fields, we consider the influence of unresolvedmore » physics and dynamics on particle trajectories. We comprehensively list and discuss the tools currently available for tracking virtual particles. We then showcase some of the innovative applications of trajectory data, and conclude with some open questions and an outlook. Our overall goal of this review paper is to reconcile some of the different techniques and methods in Lagrangian ocean analysis, while recognising the rich diversity of codes that have and continue to emerge, and the challenges of the coming age of petascale computing.« less
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Lagrangian continuum dynamics in ALEGRA.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wong, Michael K. W.; Love, Edward
Alegra is an ALE (Arbitrary Lagrangian-Eulerian) multi-material finite element code that emphasizes large deformations and strong shock physics. The Lagrangian continuum dynamics package in Alegra uses a Galerkin finite element spatial discretization and an explicit central-difference stepping method in time. The goal of this report is to describe in detail the characteristics of this algorithm, including the conservation and stability properties. The details provided should help both researchers and analysts understand the underlying theory and numerical implementation of the Alegra continuum hydrodynamics algorithm.
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Two-dimensional Lagrangian simulation of suspended sediment
Schoellhamer, David H.
1988-01-01
A two-dimensional laterally averaged model for suspended sediment transport in steady gradually varied flow that is based on the Lagrangian reference frame is presented. The layered Lagrangian transport model (LLTM) for suspended sediment performs laterally averaged concentration. The elevations of nearly horizontal streamlines and the simulation time step are selected to optimize model stability and efficiency. The computational elements are parcels of water that are moved along the streamlines in the Lagrangian sense and are mixed with neighboring parcels. Three applications show that the LLTM can accurately simulate theoretical and empirical nonequilibrium suspended sediment distributions and slug injections of suspended sediment in a laboratory flume.
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Lagrangian numerical methods for ocean biogeochemical simulations
NASA Astrophysics Data System (ADS)
Paparella, Francesco; Popolizio, Marina
2018-05-01
We propose two closely-related Lagrangian numerical methods for the simulation of physical processes involving advection, reaction and diffusion. The methods are intended to be used in settings where the flow is nearly incompressible and the Péclet numbers are so high that resolving all the scales of motion is unfeasible. This is commonplace in ocean flows. Our methods consist in augmenting the method of characteristics, which is suitable for advection-reaction problems, with couplings among nearby particles, producing fluxes that mimic diffusion, or unresolved small-scale transport. The methods conserve mass, obey the maximum principle, and allow to tune the strength of the diffusive terms down to zero, while avoiding unwanted numerical dissipation effects.
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Lagrangian Perturbation Approach to the Formation of Large-scale Structure
NASA Astrophysics Data System (ADS)
Buchert, Thomas
The present lecture notes address three columns on which the Lagrangian perturbation approach to cosmological dynamics is based: 1. the formulation of a Lagrangian theory of self-gravitating flows in which the dynamics is described in terms of a single field variable; 2. the procedure, how to obtain the dynamics of Eulerian fields from the Lagrangian picture, and 3. a precise definition of a Newtonian cosmology framework in which Lagrangian perturbation solutions can be studied. While the first is a discussion of the basic equations obtained by transforming the Eulerian evolution and field equations to the Lagrangian picture, the second exemplifies how the Lagrangian theory determines the evolution of Eulerian fields including kinematical variables like expansion, vorticity, as well as the shear and tidal tensors. The third column is based on a specification of initial and boundary conditions, and in particular on the identification of the average flow of an inhomogeneous cosmology with a `Hubble-flow'. Here, we also look at the limits of the Lagrangian perturbation approach as inferred from comparisons with N-body simulations and illustrate some striking properties of the solutions.
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An updated Lagrangian discontinuous Galerkin hydrodynamic method for gas dynamics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wu, Tong; Shashkov, Mikhail Jurievich; Morgan, Nathaniel Ray
Here, we present a new Lagrangian discontinuous Galerkin (DG) hydrodynamic method for gas dynamics. The new method evolves conserved unknowns in the current configuration, which obviates the Jacobi matrix that maps the element in a reference coordinate system or the initial coordinate system to the current configuration. The density, momentum, and total energy (ρ, ρu, E) are approximated with conservative higher-order Taylor expansions over the element and are limited toward a piecewise constant field near discontinuities using a limiter. Two new limiting methods are presented for enforcing the bounds on the primitive variables of density, velocity, and specific internal energymore » (ρ, u, e). The nodal velocity, and the corresponding forces, are calculated by solving an approximate Riemann problem at the element nodes. An explicit second-order method is used to temporally advance the solution. This new Lagrangian DG hydrodynamic method conserves mass, momentum, and total energy. 1D Cartesian coordinates test problem results are presented to demonstrate the accuracy and convergence order of the new DG method with the new limiters.« less
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An updated Lagrangian discontinuous Galerkin hydrodynamic method for gas dynamics
Wu, Tong; Shashkov, Mikhail Jurievich; Morgan, Nathaniel Ray; ...
2018-04-09
Here, we present a new Lagrangian discontinuous Galerkin (DG) hydrodynamic method for gas dynamics. The new method evolves conserved unknowns in the current configuration, which obviates the Jacobi matrix that maps the element in a reference coordinate system or the initial coordinate system to the current configuration. The density, momentum, and total energy (ρ, ρu, E) are approximated with conservative higher-order Taylor expansions over the element and are limited toward a piecewise constant field near discontinuities using a limiter. Two new limiting methods are presented for enforcing the bounds on the primitive variables of density, velocity, and specific internal energymore » (ρ, u, e). The nodal velocity, and the corresponding forces, are calculated by solving an approximate Riemann problem at the element nodes. An explicit second-order method is used to temporally advance the solution. This new Lagrangian DG hydrodynamic method conserves mass, momentum, and total energy. 1D Cartesian coordinates test problem results are presented to demonstrate the accuracy and convergence order of the new DG method with the new limiters.« less
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Lagrangian transported MDF methods for compressible high speed flows
NASA Astrophysics Data System (ADS)
Gerlinger, Peter
2017-06-01
This paper deals with the application of thermochemical Lagrangian MDF (mass density function) methods for compressible sub- and supersonic RANS (Reynolds Averaged Navier-Stokes) simulations. A new approach to treat molecular transport is presented. This technique on the one hand ensures numerical stability of the particle solver in laminar regions of the flow field (e.g. in the viscous sublayer) and on the other hand takes differential diffusion into account. It is shown in a detailed analysis, that the new method correctly predicts first and second-order moments on the basis of conventional modeling approaches. Moreover, a number of challenges for MDF particle methods in high speed flows is discussed, e.g. high cell aspect ratio grids close to solid walls, wall heat transfer, shock resolution, and problems from statistical noise which may cause artificial shock systems in supersonic flows. A Mach 2 supersonic mixing channel with multiple shock reflection and a model rocket combustor simulation demonstrate the eligibility of this technique to practical applications. Both test cases are simulated successfully for the first time with a hybrid finite-volume (FV)/Lagrangian particle solver (PS).
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Scale-by-scale contributions to Lagrangian particle acceleration
NASA Astrophysics Data System (ADS)
Lalescu, Cristian C.; Wilczek, Michael
2017-11-01
Fluctuations on a wide range of scales in both space and time are characteristic of turbulence. Lagrangian particles, advected by the flow, probe these fluctuations along their trajectories. In an effort to isolate the influence of the different scales on Lagrangian statistics, we employ direct numerical simulations (DNS) combined with a filtering approach. Specifically, we study the acceleration statistics of tracers advected in filtered fields to characterize the smallest temporal scales of the flow. Emphasis is put on the acceleration variance as a function of filter scale, along with the scaling properties of the relevant terms of the Navier-Stokes equations. We furthermore discuss scaling ranges for higher-order moments of the tracer acceleration, as well as the influence of the choice of filter on the results. Starting from the Lagrangian tracer acceleration as the short time limit of the Lagrangian velocity increment, we also quantify the influence of filtering on Lagrangian intermittency. Our work complements existing experimental results on intermittency and accelerations of finite-sized, neutrally-buoyant particles: for the passive tracers used in our DNS, feedback effects are neglected such that the spatial averaging effect is cleanly isolated.
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Chaotic Lagrangian models for turbulent relative dispersion.
Lacorata, Guglielmo; Vulpiani, Angelo
2017-04-01
A deterministic multiscale dynamical system is introduced and discussed as a prototype model for relative dispersion in stationary, homogeneous, and isotropic turbulence. Unlike stochastic diffusion models, here trajectory transport and mixing properties are entirely controlled by Lagrangian chaos. The anomalous "sweeping effect," a known drawback common to kinematic simulations, is removed through the use of quasi-Lagrangian coordinates. Lagrangian dispersion statistics of the model are accurately analyzed by computing the finite-scale Lyapunov exponent (FSLE), which is the optimal measure of the scaling properties of dispersion. FSLE scaling exponents provide a severe test to decide whether model simulations are in agreement with theoretical expectations and/or observation. The results of our numerical experiments cover a wide range of "Reynolds numbers" and show that chaotic deterministic flows can be very efficient, and numerically low-cost, models of turbulent trajectories in stationary, homogeneous, and isotropic conditions. The mathematics of the model is relatively simple, and, in a geophysical context, potential applications may regard small-scale parametrization issues in general circulation models, mixed layer, and/or boundary layer turbulence models as well as Lagrangian predictability studies.
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Lagrangian statistics in compressible isotropic homogeneous turbulence
NASA Astrophysics Data System (ADS)
Yang, Yantao; Wang, Jianchun; Shi, Yipeng; Chen, Shiyi
2011-11-01
In this work we conducted the Direct Numerical Simulation (DNS) of a forced compressible isotropic homogeneous turbulence and investigated the flow statistics from the Lagrangian point of view, namely the statistics is computed following the passive tracers trajectories. The numerical method combined the Eulerian field solver which was developed by Wang et al. (2010, J. Comp. Phys., 229, 5257-5279), and a Lagrangian module for tracking the tracers and recording the data. The Lagrangian probability density functions (p.d.f.'s) have then been calculated for both kinetic and thermodynamic quantities. In order to isolate the shearing part from the compressing part of the flow, we employed the Helmholtz decomposition to decompose the flow field (mainly the velocity field) into the solenoidal and compressive parts. The solenoidal part was compared with the incompressible case, while the compressibility effect showed up in the compressive part. The Lagrangian structure functions and cross-correlation between various quantities will also be discussed. This work was supported in part by the China's Turbulence Program under Grant No.2009CB724101.
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Chaotic Lagrangian models for turbulent relative dispersion
NASA Astrophysics Data System (ADS)
Lacorata, Guglielmo; Vulpiani, Angelo
2017-04-01
A deterministic multiscale dynamical system is introduced and discussed as a prototype model for relative dispersion in stationary, homogeneous, and isotropic turbulence. Unlike stochastic diffusion models, here trajectory transport and mixing properties are entirely controlled by Lagrangian chaos. The anomalous "sweeping effect," a known drawback common to kinematic simulations, is removed through the use of quasi-Lagrangian coordinates. Lagrangian dispersion statistics of the model are accurately analyzed by computing the finite-scale Lyapunov exponent (FSLE), which is the optimal measure of the scaling properties of dispersion. FSLE scaling exponents provide a severe test to decide whether model simulations are in agreement with theoretical expectations and/or observation. The results of our numerical experiments cover a wide range of "Reynolds numbers" and show that chaotic deterministic flows can be very efficient, and numerically low-cost, models of turbulent trajectories in stationary, homogeneous, and isotropic conditions. The mathematics of the model is relatively simple, and, in a geophysical context, potential applications may regard small-scale parametrization issues in general circulation models, mixed layer, and/or boundary layer turbulence models as well as Lagrangian predictability studies.
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NASA Astrophysics Data System (ADS)
Al Roumi, Fosca; Buchert, Thomas; Wiegand, Alexander
2017-12-01
The relativistic generalization of the Newtonian Lagrangian perturbation theory is investigated. In previous works, the perturbation and solution schemes that are generated by the spatially projected gravitoelectric part of the Weyl tensor were given to any order of the perturbations, together with extensions and applications for accessing the nonperturbative regime. We here discuss more in detail the general first-order scheme within the Cartan formalism including and concentrating on the gravitational wave propagation in matter. We provide master equations for all parts of Lagrangian-linearized perturbations propagating in the perturbed spacetime, and we outline the solution procedure that allows one to find general solutions. Particular emphasis is given to global properties of the Lagrangian perturbation fields by employing results of Hodge-de Rham theory. We here discuss how the Hodge decomposition relates to the standard scalar-vector-tensor decomposition. Finally, we demonstrate that we obtain the known linear perturbation solutions of the standard relativistic perturbation scheme by performing two steps: first, by restricting our solutions to perturbations that propagate on a flat unperturbed background spacetime and, second, by transforming to Eulerian background coordinates with truncation of nonlinear terms.
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Imposing a Lagrangian Particle Framework on an Eulerian Hydrodynamics Infrastructure in Flash
NASA Technical Reports Server (NTRS)
Dubey, A.; Daley, C.; ZuHone, J.; Ricker, P. M.; Weide, K.; Graziani, C.
2012-01-01
In many astrophysical simulations, both Eulerian and Lagrangian quantities are of interest. For example, in a galaxy cluster merger simulation, the intracluster gas can have Eulerian discretization, while dark matter can be modeled using particles. FLASH, a component-based scientific simulation code, superimposes a Lagrangian framework atop an adaptive mesh refinement Eulerian framework to enable such simulations. The discretization of the field variables is Eulerian, while the Lagrangian entities occur in many different forms including tracer particles, massive particles, charged particles in particle-in-cell mode, and Lagrangian markers to model fluid structure interactions. These widely varying roles for Lagrangian entities are possible because of the highly modular, flexible, and extensible architecture of the Lagrangian framework. In this paper, we describe the Lagrangian framework in FLASH in the context of two very different applications, Type Ia supernovae and galaxy cluster mergers, which use the Lagrangian entities in fundamentally different ways.
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Imposing a Lagrangian Particle Framework on an Eulerian Hydrodynamics Infrastructure in FLASH
NASA Astrophysics Data System (ADS)
Dubey, A.; Daley, C.; ZuHone, J.; Ricker, P. M.; Weide, K.; Graziani, C.
2012-08-01
In many astrophysical simulations, both Eulerian and Lagrangian quantities are of interest. For example, in a galaxy cluster merger simulation, the intracluster gas can have Eulerian discretization, while dark matter can be modeled using particles. FLASH, a component-based scientific simulation code, superimposes a Lagrangian framework atop an adaptive mesh refinement Eulerian framework to enable such simulations. The discretization of the field variables is Eulerian, while the Lagrangian entities occur in many different forms including tracer particles, massive particles, charged particles in particle-in-cell mode, and Lagrangian markers to model fluid-structure interactions. These widely varying roles for Lagrangian entities are possible because of the highly modular, flexible, and extensible architecture of the Lagrangian framework. In this paper, we describe the Lagrangian framework in FLASH in the context of two very different applications, Type Ia supernovae and galaxy cluster mergers, which use the Lagrangian entities in fundamentally different ways.
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Mass properties measurement system dynamics
NASA Technical Reports Server (NTRS)
Doty, Keith L.
1993-01-01
The MPMS mechanism possess two revolute degrees-of-freedom and allows the user to measure the mass, center of gravity, and the inertia tensor of an unknown mass. The dynamics of the Mass Properties Measurement System (MPMS) from the Lagrangian approach to illustrate the dependency of the motion on the unknown parameters.
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Eulerian and Lagrangian approaches to multidimensional condensation and collection
NASA Astrophysics Data System (ADS)
Li, Xiang-Yu; Brandenburg, A.; Haugen, N. E. L.; Svensson, G.
2017-06-01
Turbulence is argued to play a crucial role in cloud droplet growth. The combined problem of turbulence and cloud droplet growth is numerically challenging. Here an Eulerian scheme based on the Smoluchowski equation is compared with two Lagrangian superparticle (or superdroplet) schemes in the presence of condensation and collection. The growth processes are studied either separately or in combination using either two-dimensional turbulence, a steady flow or just gravitational acceleration without gas flow. Good agreement between the different schemes for the time evolution of the size spectra is observed in the presence of gravity or turbulence. The Lagrangian superparticle schemes are found to be superior over the Eulerian one in terms of computational performance. However, it is shown that the use of interpolation schemes such as the cloud-in-cell algorithm is detrimental in connection with superparticle or superdroplet approaches. Furthermore, the use of symmetric over asymmetric collection schemes is shown to reduce the amount of scatter in the results. For the Eulerian scheme, gravitational collection is rather sensitive to the mass bin resolution, but not so in the case with turbulence.
Plain Language SummaryThe bottleneck problem of cloud droplet growth is one of the most challenging problems in cloud physics. Cloud droplet growth is neither dominated by condensation nor gravitational collision in the size range of 15 μm ˜ 40 μm [1]. Turbulence-generated collection has been thought to be the mechanism to bridge the size gap, i.e., the bottleneck problem. This study compares the <span class="hlt">Lagrangian</span> and Eulerian schemes in detail to tackle with the turbulence-generated collection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ascl.soft02021T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ascl.soft02021T"><span>COLAcode: COmoving <span class="hlt">Lagrangian</span> Acceleration code</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tassev, Svetlin V.</p> <p>2016-02-01</p> <p>COLAcode is a serial particle mesh-based N-body code illustrating the COLA (COmoving <span class="hlt">Lagrangian</span> Acceleration) method; it solves for Large Scale Structure (LSS) in a frame that is comoving with observers following trajectories calculated in <span class="hlt">Lagrangian</span> Perturbation Theory (LPT). It differs from standard N-body code by trading accuracy at small-scales to gain computational speed without sacrificing accuracy at large scales. This is useful for generating large ensembles of accurate mock halo catalogs required to study galaxy clustering and weak lensing; such catalogs are needed to perform detailed error analysis for ongoing and future surveys of LSS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29543033','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29543033"><span>Nonunitary <span class="hlt">Lagrangians</span> and Unitary Non-<span class="hlt">Lagrangian</span> Conformal Field Theories.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Buican, Matthew; Laczko, Zoltan</p> <p>2018-02-23</p> <p>In various dimensions, we can sometimes compute observables of interacting conformal field theories (CFTs) that are connected to free theories via the renormalization group (RG) flow by computing protected quantities in the free theories. On the other hand, in two dimensions, it is often possible to algebraically construct observables of interacting CFTs using free fields without the need to explicitly construct an underlying RG flow. In this Letter, we begin to extend this idea to higher dimensions by showing that one can compute certain observables of an infinite set of unitary strongly interacting four-dimensional N=2 superconformal field theories (SCFTs) by performing simple calculations involving sets of nonunitary free four-dimensional hypermultiplets. These free fields are distant cousins of the Majorana fermion underlying the two-dimensional Ising model and are not obviously connected to our interacting theories via an RG flow. Rather surprisingly, this construction gives us <span class="hlt">Lagrangians</span> for particular observables in certain subsectors of many "non-<span class="hlt">Lagrangian</span>" SCFTs by sacrificing unitarity while preserving the full N=2 superconformal algebra. As a by-product, we find relations between characters in unitary and nonunitary affine Kac-Moody algebras. We conclude by commenting on possible generalizations of our construction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvL.120h1601B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvL.120h1601B"><span>Nonunitary <span class="hlt">Lagrangians</span> and Unitary Non-<span class="hlt">Lagrangian</span> Conformal Field Theories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buican, Matthew; Laczko, Zoltan</p> <p>2018-02-01</p> <p>In various dimensions, we can sometimes compute observables of interacting conformal field theories (CFTs) that are connected to free theories via the renormalization group (RG) flow by computing protected quantities in the free theories. On the other hand, in two dimensions, it is often possible to algebraically construct observables of interacting CFTs using free fields without the need to explicitly construct an underlying RG flow. In this Letter, we begin to extend this idea to higher dimensions by showing that one can compute certain observables of an infinite set of unitary strongly interacting four-dimensional N =2 superconformal field theories (SCFTs) by performing simple calculations involving sets of nonunitary free four-dimensional hypermultiplets. These free fields are distant cousins of the Majorana fermion underlying the two-dimensional Ising model and are not obviously connected to our interacting theories via an RG flow. Rather surprisingly, this construction gives us <span class="hlt">Lagrangians</span> for particular observables in certain subsectors of many "non-<span class="hlt">Lagrangian</span>" SCFTs by sacrificing unitarity while preserving the full N =2 superconformal algebra. As a by-product, we find relations between characters in unitary and nonunitary affine Kac-Moody algebras. We conclude by commenting on possible generalizations of our construction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JCoPh.351..422P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JCoPh.351..422P"><span>An adaptive reconstruction for <span class="hlt">Lagrangian</span>, direct-forcing, immersed-boundary methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Posa, Antonio; Vanella, Marcos; Balaras, Elias</p> <p>2017-12-01</p> <p><span class="hlt">Lagrangian</span>, direct-forcing, immersed boundary (IB) methods have been receiving increased attention due to their robustness in complex fluid-structure interaction problems. They are very sensitive, however, on the selection of the <span class="hlt">Lagrangian</span> grid, which is typically used to define a solid or flexible body immersed in a fluid flow. In the present work we propose a cost-efficient solution to this problem without compromising accuracy. Central to our approach is the use of isoparametric mapping to bridge the relative resolution requirements of <span class="hlt">Lagrangian</span> IB, and Eulerian grids. With this approach, the density of surface <span class="hlt">Lagrangian</span> markers, which is essential to properly enforce boundary conditions, is adapted dynamically based on the characteristics of the underlying Eulerian grid. The markers are not stored and the <span class="hlt">Lagrangian</span> data-structure is not modified. The proposed scheme is implemented in the framework of a moving least squares reconstruction formulation, but it can be adapted to any <span class="hlt">Lagrangian</span>, direct-forcing formulation. The accuracy and robustness of the approach is demonstrated in a variety of test cases of increasing complexity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJMPS..4260159F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJMPS..4260159F"><span>a Marker-Based Eulerian-<span class="hlt">Lagrangian</span> Method for Multiphase Flow with Supersonic Combustion Applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fan, Xiaofeng; Wang, Jiangfeng</p> <p>2016-06-01</p> <p>The atomization of liquid fuel is a kind of intricate dynamic process from continuous phase to discrete phase. Procedures of fuel spray in supersonic flow are modeled with an Eulerian-<span class="hlt">Lagrangian</span> computational fluid dynamics methodology. The method combines two distinct techniques and develops an integrated numerical simulation method to simulate the atomization processes. The traditional finite volume method based on stationary (Eulerian) Cartesian grid is used to resolve the flow field, and multi-component Navier-Stokes equations are adopted in present work, with accounting for the <span class="hlt">mass</span> exchange and heat transfer occupied by vaporization process. The marker-based moving (<span class="hlt">Lagrangian</span>) grid is utilized to depict the behavior of atomized liquid sprays injected into a gaseous environment, and discrete droplet model 13 is adopted. To verify the current approach, the proposed method is applied to simulate processes of liquid atomization in supersonic cross flow. Three classic breakup models, TAB model, wave model and K-H/R-T hybrid model, are discussed. The numerical results are compared with multiple perspectives quantitatively, including spray penetration height and droplet size distribution. In addition, the complex flow field structures induced by the presence of liquid spray are illustrated and discussed. It is validated that the maker-based Eulerian-<span class="hlt">Lagrangian</span> method is effective and reliable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IJGMM..1450171E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IJGMM..1450171E"><span>Scalar curvature of <span class="hlt">Lagrangian</span> Riemannian submersions and their harmonicity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eken Meri˙ç, Şemsi; Kiliç, Erol; Sağiroğlu, Yasemi˙n</p> <p></p> <p>In this paper, we consider a <span class="hlt">Lagrangian</span> Riemannian submersion from a Hermitian manifold to a Riemannian manifold and establish some basic inequalities to obtain relationships between the intrinsic and extrinsic invariants for such a submersion. Indeed, using these inequalities, we provide necessary and sufficient conditions for which a <span class="hlt">Lagrangian</span> Riemannian submersion π has totally geodesic or totally umbilical fibers. Moreover, we study the harmonicity of <span class="hlt">Lagrangian</span> Riemannian submersions and obtain a characterization for such submersions to be harmonic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1270630','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1270630"><span>A <span class="hlt">Lagrangian</span> effective field theory</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Vlah, Zvonimir; White, Martin; Aviles, Alejandro</p> <p></p> <p>We have continued the development of <span class="hlt">Lagrangian</span>, cosmological perturbation theory for the low-order correlators of the matter density field. We provide a new route to understanding how the effective field theory (EFT) of large-scale structure can be formulated in the Lagrandian framework and a new resummation scheme, comparing our results to earlier work and to a series of high-resolution N-body simulations in both Fourier and configuration space. The `new' terms arising from EFT serve to tame the dependence of perturbation theory on small-scale physics and improve agreement with simulations (though with an additional free parameter). We find that all ofmore » our models fare well on scales larger than about two to three times the non-linear scale, but fail as the non-linear scale is approached. This is slightly less reach than has been seen previously. At low redshift the <span class="hlt">Lagrangian</span> model fares as well as EFT in its Eulerian formulation, but at higher z the Eulerian EFT fits the data to smaller scales than resummed, <span class="hlt">Lagrangian</span> EFT. Furthermore, all the perturbative models fare better than linear theory.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22525478-lagrangian-effective-field-theory','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22525478-lagrangian-effective-field-theory"><span>A <span class="hlt">Lagrangian</span> effective field theory</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Vlah, Zvonimir; White, Martin; Aviles, Alejandro, E-mail: zvlah@stanford.edu, E-mail: mwhite@berkeley.edu, E-mail: aviles@berkeley.edu</p> <p></p> <p>We have continued the development of <span class="hlt">Lagrangian</span>, cosmological perturbation theory for the low-order correlators of the matter density field. We provide a new route to understanding how the effective field theory (EFT) of large-scale structure can be formulated in the Lagrandian framework and a new resummation scheme, comparing our results to earlier work and to a series of high-resolution N-body simulations in both Fourier and configuration space. The 'new' terms arising from EFT serve to tame the dependence of perturbation theory on small-scale physics and improve agreement with simulations (though with an additional free parameter). We find that all ofmore » our models fare well on scales larger than about two to three times the non-linear scale, but fail as the non-linear scale is approached. This is slightly less reach than has been seen previously. At low redshift the <span class="hlt">Lagrangian</span> model fares as well as EFT in its Eulerian formulation, but at higher z the Eulerian EFT fits the data to smaller scales than resummed, <span class="hlt">Lagrangian</span> EFT. All the perturbative models fare better than linear theory.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1270630-lagrangian-effective-field-theory','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1270630-lagrangian-effective-field-theory"><span>A <span class="hlt">Lagrangian</span> effective field theory</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Vlah, Zvonimir; White, Martin; Aviles, Alejandro</p> <p>2015-09-02</p> <p>We have continued the development of <span class="hlt">Lagrangian</span>, cosmological perturbation theory for the low-order correlators of the matter density field. We provide a new route to understanding how the effective field theory (EFT) of large-scale structure can be formulated in the Lagrandian framework and a new resummation scheme, comparing our results to earlier work and to a series of high-resolution N-body simulations in both Fourier and configuration space. The `new' terms arising from EFT serve to tame the dependence of perturbation theory on small-scale physics and improve agreement with simulations (though with an additional free parameter). We find that all ofmore » our models fare well on scales larger than about two to three times the non-linear scale, but fail as the non-linear scale is approached. This is slightly less reach than has been seen previously. At low redshift the <span class="hlt">Lagrangian</span> model fares as well as EFT in its Eulerian formulation, but at higher z the Eulerian EFT fits the data to smaller scales than resummed, <span class="hlt">Lagrangian</span> EFT. Furthermore, all the perturbative models fare better than linear theory.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.458.1517F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.458.1517F"><span><span class="hlt">Lagrangian</span> methods of cosmic web classification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fisher, J. D.; Faltenbacher, A.; Johnson, M. S. T.</p> <p>2016-05-01</p> <p>The cosmic web defines the large-scale distribution of matter we see in the Universe today. Classifying the cosmic web into voids, sheets, filaments and nodes allows one to explore structure formation and the role environmental factors have on halo and galaxy properties. While existing studies of cosmic web classification concentrate on grid-based methods, this work explores a <span class="hlt">Lagrangian</span> approach where the V-web algorithm proposed by Hoffman et al. is implemented with techniques borrowed from smoothed particle hydrodynamics. The <span class="hlt">Lagrangian</span> approach allows one to classify individual objects (e.g. particles or haloes) based on properties of their nearest neighbours in an adaptive manner. It can be applied directly to a halo sample which dramatically reduces computational cost and potentially allows an application of this classification scheme to observed galaxy samples. Finally, the <span class="hlt">Lagrangian</span> nature admits a straightforward inclusion of the Hubble flow negating the necessity of a visually defined threshold value which is commonly employed by grid-based classification methods.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1013709','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1013709"><span>Bayesian Nonlinear Assimilation of Eulerian and <span class="hlt">Lagrangian</span> Coastal Flow Data</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-09-30</p> <p><span class="hlt">Lagrangian</span> Coastal Flow Data Dr. Pierre F.J. Lermusiaux Department of Mechanical Engineering Center for Ocean Science and Engineering Massachusetts...Develop and apply theory, schemes and computational systems for rigorous Bayesian nonlinear assimilation of Eulerian and <span class="hlt">Lagrangian</span> coastal flow data...coastal ocean fields, both in Eulerian and <span class="hlt">Lagrangian</span> forms. - Further develop and implement our GMM-DO schemes for robust Bayesian nonlinear estimation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70011338','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70011338"><span>Euler-<span class="hlt">Lagrangian</span> computation for estuarine hydrodynamics</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cheng, Ralph T.</p> <p>1983-01-01</p> <p>The transport of conservative and suspended matter in fluid flows is a phenomenon of <span class="hlt">Lagrangian</span> nature because the process is usually convection dominant. Nearly all numerical investigations of such problems use an Eulerian formulation for the convenience that the computational grids are fixed in space and because the vast majority of field data are collected in an Eulerian reference frame. Several examples are given in this paper to illustrate a modeling approach which combines the advantages of both the Eulerian and <span class="hlt">Lagrangian</span> computational techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970001872','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970001872"><span>An Extended <span class="hlt">Lagrangian</span> Method</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liou, Meng-Sing</p> <p>1995-01-01</p> <p>A unique formulation of describing fluid motion is presented. The method, referred to as 'extended <span class="hlt">Lagrangian</span> method,' is interesting from both theoretical and numerical points of view. The formulation offers accuracy in numerical solution by avoiding numerical diffusion resulting from mixing of fluxes in the Eulerian description. The present method and the Arbitrary <span class="hlt">Lagrangian</span>-Eulerian (ALE) method have a similarity in spirit-eliminating the cross-streamline numerical diffusion. For this purpose, we suggest a simple grid constraint condition and utilize an accurate discretization procedure. This grid constraint is only applied to the transverse cell face parallel to the local stream velocity, and hence our method for the steady state problems naturally reduces to the streamline-curvature method, without explicitly solving the steady stream-coordinate equations formulated a priori. Unlike the <span class="hlt">Lagrangian</span> method proposed by Loh and Hui which is valid only for steady supersonic flows, the present method is general and capable of treating subsonic flows and supersonic flows as well as unsteady flows, simply by invoking in the same code an appropriate grid constraint suggested in this paper. The approach is found to be robust and stable. It automatically adapts to flow features without resorting to clustering, thereby maintaining rather uniform grid spacing throughout and large time step. Moreover, the method is shown to resolve multi-dimensional discontinuities with a high level of accuracy, similar to that found in one-dimensional problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OcDyn..67.1567C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OcDyn..67.1567C"><span>Laboratory experiment on the 3D tide-induced <span class="hlt">Lagrangian</span> residual current using the PIV technique</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Yang; Jiang, Wensheng; Chen, Xu; Wang, Tao; Bian, Changwei</p> <p>2017-12-01</p> <p>The 3D structure of the tide-induced <span class="hlt">Lagrangian</span> residual current was studied using the particle image velocimetry (PIV) technique in a long shallow narrow tank in the laboratory. At the mouth of the tank, a wave generator was used to make periodic wave which represents the tide movement, and at the head of the tank, a laterally sloping topography with the length of one fifth of the water tank was installed, above which the tide-induced <span class="hlt">Lagrangian</span> residual current was studied. Under the weakly nonlinear condition in the present experiment setup, the results show that the <span class="hlt">Lagrangian</span> residual velocity (LRV) field has a three-layer structure. The residual current flows inwards (towards the head) in the bottom layer and flows outwards in the middle layer, while in the surface layer, it flows inwards along the shallow side of the sloping topography and outwards along the deep side. The depth-averaged and breadth-averaged LRV are also analyzed based on the 3D LRV observations. Our results are in good agreement with the previous experiment studies, the analytical solutions with similar conditions and the observational results in real bays. Moreover, the volume flux comparison between the <span class="hlt">Lagrangian</span> and Eulerian residual currents shows that the Eulerian residual velocity violates the <span class="hlt">mass</span> conservation law while the LRV truly represents the inter-tidal water transport. This work enriches the laboratory studies of the LRV and offers valuable references for the LRV studies in real bays.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930061006&hterms=sing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsing','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930061006&hterms=sing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsing"><span>An extended <span class="hlt">Lagrangian</span> method</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liou, Meng-Sing</p> <p>1993-01-01</p> <p>A unique formulation of describing fluid motion is presented. The method, referred to as 'extended <span class="hlt">Lagrangian</span> method', is interesting from both theoretical and numerical points of view. The formulation offers accuracy in numerical solution by avoiding numerical diffusion resulting from mixing of fluxes in the Eulerian description. Meanwhile, it also avoids the inaccuracy incurred due to geometry and variable interpolations used by the previous <span class="hlt">Lagrangian</span> methods. The present method is general and capable of treating subsonic flows as well as supersonic flows. The method proposed in this paper is robust and stable. It automatically adapts to flow features without resorting to clustering, thereby maintaining rather uniform grid spacing throughout and large time step. Moreover, the method is shown to resolve multidimensional discontinuities with a high level of accuracy, similar to that found in 1D problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22499090-few-words-about-resonances-electroweak-effective-lagrangian','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22499090-few-words-about-resonances-electroweak-effective-lagrangian"><span>A few words about resonances in the electroweak effective <span class="hlt">Lagrangian</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Rosell, Ignasi; Pich, Antonio; Santos, Joaquín</p> <p></p> <p>Contrary to a widely spread believe, we have demonstrated that strongly coupled electroweak models including both a light Higgs-like boson and massive spin-1 resonances are not in conflict with experimental constraints on the oblique S and T parameters. We use an effective <span class="hlt">Lagrangian</span> implementing the chiral symmetry breaking SU (2){sub L} ⊗ SU (2){sub R} → SU (2){sub L+R} that contains the Standard Model gauge bosons coupled to the electroweak Goldstones, one Higgs-like scalar state h with <span class="hlt">mass</span> m{sub h} = 126 GeV and the lightest vector and axial-vector resonance multiplets V and A. We have considered the one-loop calculationmore » of S and T in order to study the viability of these strongly-coupled scenarios, being short-distance constraints and dispersive relations the main ingredients of the calculation. Once we have constrained the resonance parameters, we do a first approach to the determination of the low energy constants of the electroweak effective theory at low energies (without resonances). We show this determination in the case of the purely Higgsless bosonic <span class="hlt">Lagrangian</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JHEP...12..104D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JHEP...12..104D"><span>Spontaneous CP breaking in QCD and the axion potential: an effective <span class="hlt">Lagrangian</span> approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Di Vecchia, Paolo; Rossi, Giancarlo; Veneziano, Gabriele; Yankielowicz, Shimon</p> <p>2017-12-01</p> <p>Using the well-known low-energy effective <span class="hlt">Lagrangian</span> of QCD — valid for small (non-vanishing) quark <span class="hlt">masses</span> and a large number of colors — we study in detail the regions of parameter space where CP is spontaneously broken/unbroken for a vacuum angle θ = π. In the CP broken region there are first order phase transitions as one crosses θ = π, while on the (hyper)surface separating the two regions, there are second order phase transitions signalled by the vanishing of the <span class="hlt">mass</span> of a pseudo Nambu-Goldstone boson and by a divergent QCD topological susceptibility. The second order point sits at the end of a first order line associated with the CP spontaneous breaking, in the appropriate complex parameter plane. When the effective <span class="hlt">Lagrangian</span> is extended by the inclusion of an axion these features of QCD imply that standard calculations of the axion potential have to be revised if the QCD parameters fall in the above mentioned CP broken region, in spite of the fact that the axion solves the strong- CP problem. These last results could be of interest for axionic dark matter calculations if the topological susceptibility of pure Yang-Mills theory falls off sufficiently fast when temperature is increased towards the QCD deconfining transition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018CPM...tmp....2F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018CPM...tmp....2F"><span>Meshless <span class="hlt">Lagrangian</span> SPH method applied to isothermal lid-driven cavity flow at low-Re numbers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fraga Filho, C. A. D.; Chacaltana, J. T. A.; Pinto, W. J. N.</p> <p>2018-01-01</p> <p>SPH is a recent particle method applied in the cavities study, without many results available in the literature. The lid-driven cavity flow is a classic problem of the fluid mechanics, extensively explored in the literature and presenting a considerable complexity. The aim of this paper is to present a solution from the <span class="hlt">Lagrangian</span> viewpoint for this problem. The discretization of the continuum domain is performed using the <span class="hlt">Lagrangian</span> particles. The physical laws of <span class="hlt">mass</span>, momentum and energy conservation are presented by the Navier-Stokes equations. A serial numerical code, written in Fortran programming language, has been used to perform the numerical simulations. The application of the SPH and comparison with the literature (mesh methods and a meshless collocation method) have been done. The positions of the primary vortex centre and the non-dimensional velocity profiles passing through the geometric centre of the cavity have been analysed. The numerical <span class="hlt">Lagrangian</span> results showed a good agreement when compared to the results found in the literature, specifically for { Re} < 100.00 . Suggestions for improvements in the SPH model presented are listed, in the search for better results for flows with higher Reynolds numbers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhLB..772..694C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhLB..772..694C"><span>Extended hamiltonian formalism and Lorentz-violating <span class="hlt">lagrangians</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Colladay, Don</p> <p>2017-09-01</p> <p>A new perspective on the classical mechanical formulation of particle trajectories in Lorentz-violating theories is presented. Using the extended hamiltonian formalism, a Legendre Transformation between the associated covariant <span class="hlt">lagrangian</span> and hamiltonian varieties is constructed. This approach enables calculation of trajectories using Hamilton's equations in momentum space and the Euler-Lagrange equations in velocity space away from certain singular points that arise in the theory. Singular points are naturally de-singularized by requiring the trajectories to be smooth functions of both velocity and momentum variables. In addition, it is possible to identify specific sheets of the dispersion relations that correspond to specific solutions for the <span class="hlt">lagrangian</span>. Examples corresponding to bipartite Finsler functions are computed in detail. A direct connection between the <span class="hlt">lagrangians</span> and the field-theoretic solutions to the Dirac equation is also established for a special case.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25903879','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25903879"><span>Thermostating extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Martínez, Enrique; Cawkwell, Marc J; Voter, Arthur F; Niklasson, Anders M N</p> <p>2015-04-21</p> <p>Extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics is developed and analyzed for applications in canonical (NVT) simulations. Three different approaches are considered: the Nosé and Andersen thermostats and Langevin dynamics. We have tested the temperature distribution under different conditions of self-consistent field (SCF) convergence and time step and compared the results to analytical predictions. We find that the simulations based on the extended <span class="hlt">Lagrangian</span> Born-Oppenheimer framework provide accurate canonical distributions even under approximate SCF convergence, often requiring only a single diagonalization per time step, whereas regular Born-Oppenheimer formulations exhibit unphysical fluctuations unless a sufficiently high degree of convergence is reached at each time step. The thermostated extended <span class="hlt">Lagrangian</span> framework thus offers an accurate approach to sample processes in the canonical ensemble at a fraction of the computational cost of regular Born-Oppenheimer molecular dynamics simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1247151','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1247151"><span>Adaptive reconnection-based arbitrary <span class="hlt">Lagrangian</span> Eulerian method</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bo, Wurigen; Shashkov, Mikhail</p> <p></p> <p>We present a new adaptive Arbitrary <span class="hlt">Lagrangian</span> Eulerian (ALE) method. This method is based on the reconnection-based ALE (ReALE) methodology of Refs. [35], [34] and [6]. The main elements in a standard ReALE method are: an explicit <span class="hlt">Lagrangian</span> phase on an arbitrary polygonal (in 2D) mesh in which the solution and positions of grid nodes are updated; a rezoning phase in which a new grid is defined by changing the connectivity (using Voronoi tessellation) but not the number of cells; and a remapping phase in which the <span class="hlt">Lagrangian</span> solution is transferred onto the new grid. Furthermore, in the standard ReALEmore » method, the rezoned mesh is smoothed by using one or several steps toward centroidal Voronoi tessellation, but it is not adapted to the solution in any way.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1247151-adaptive-reconnection-based-arbitrary-lagrangian-eulerian-method','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1247151-adaptive-reconnection-based-arbitrary-lagrangian-eulerian-method"><span>Adaptive reconnection-based arbitrary <span class="hlt">Lagrangian</span> Eulerian method</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Bo, Wurigen; Shashkov, Mikhail</p> <p>2015-07-21</p> <p>We present a new adaptive Arbitrary <span class="hlt">Lagrangian</span> Eulerian (ALE) method. This method is based on the reconnection-based ALE (ReALE) methodology of Refs. [35], [34] and [6]. The main elements in a standard ReALE method are: an explicit <span class="hlt">Lagrangian</span> phase on an arbitrary polygonal (in 2D) mesh in which the solution and positions of grid nodes are updated; a rezoning phase in which a new grid is defined by changing the connectivity (using Voronoi tessellation) but not the number of cells; and a remapping phase in which the <span class="hlt">Lagrangian</span> solution is transferred onto the new grid. Furthermore, in the standard ReALEmore » method, the rezoned mesh is smoothed by using one or several steps toward centroidal Voronoi tessellation, but it is not adapted to the solution in any way.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70164423','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70164423"><span>On <span class="hlt">Lagrangian</span> residual currents with applications in south San Francisco Bay, California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cheng, Ralph T.; Casulli, Vincenzo</p> <p>1982-01-01</p> <p>The <span class="hlt">Lagrangian</span> residual circulation has often been introduced as the sum of the Eulerian residual circulation and the Stokes' drift. Unfortunately, this definition of the <span class="hlt">Lagrangian</span> residual circulation is conceptually incorrect because both the Eulerian residual circulation and the Stokes' drift are Eulerian variables. In this paper a classification of various residual variables are reviewed and properly defined. The <span class="hlt">Lagrangian</span> residual circulation is then studied by means of a two-stage formulation of a computer model. The tidal circulation is first computed in a conventional Eulerian way, and then the <span class="hlt">Lagrangian</span> residual circulation is determined by a method patterned after the method of markers and cells. To demonstrate properties of the <span class="hlt">Lagrangian</span> residual circulation, application of this approach in South San Francisco Bay, California, is considered. With the aid of the model results, properties of the Eulerian and <span class="hlt">Lagrangian</span> residual circulation are examined. It can be concluded that estimation of the <span class="hlt">Lagrangian</span> residual circulation from Eulerian data may lead to unacceptable error, particularly in a tidal estuary where the tidal excursion is of the same order of magnitude as the length scale of the basin. A direction calculation of the <span class="hlt">Lagrangian</span> residual circulation must be made and has been shown to be feasible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JHEP...07..061G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JHEP...07..061G"><span>Parent formulation at the <span class="hlt">Lagrangian</span> level</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grigoriev, Maxim</p> <p>2011-07-01</p> <p>The recently proposed first-order parent formalism at the level of equations of motion is specialized to the case of <span class="hlt">Lagrangian</span> systems. It is shown that for diffeomorphism-invariant theories the parent formulation takes the form of an AKSZ-type sigma model. The proposed formulation can be also seen as a <span class="hlt">Lagrangian</span> version of the BV-BRST extension of the Vasiliev unfolded approach. We also discuss its possible interpretation as a multidimensional generalization of the Hamiltonian BFV-BRST formalism. The general construction is illustrated by examples of (parametrized) mechanics, relativistic particle, Yang-Mills theory, and gravity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1422959','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1422959"><span>Thermostating extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Martínez, Enrique; Cawkwell, Marc J.; Voter, Arthur F.</p> <p></p> <p>Here, Extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics is developed and analyzed for applications in canonical (NVT) simulations. Three different approaches are considered: the Nosé and Andersen thermostats and Langevin dynamics. We have tested the temperature distribution under different conditions of self-consistent field (SCF) convergence and time step and compared the results to analytical predictions. We find that the simulations based on the extended <span class="hlt">Lagrangian</span> Born-Oppenheimer framework provide accurate canonical distributions even under approximate SCF convergence, often requiring only a single diagonalization per time step, whereas regular Born-Oppenheimer formulations exhibit unphysical fluctuations unless a sufficiently high degree of convergence is reached atmore » each time step. Lastly, the thermostated extended <span class="hlt">Lagrangian</span> framework thus offers an accurate approach to sample processes in the canonical ensemble at a fraction of the computational cost of regular Born-Oppenheimer molecular dynamics simulations.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1422959-thermostating-extended-lagrangian-born-oppenheimer-molecular-dynamics','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1422959-thermostating-extended-lagrangian-born-oppenheimer-molecular-dynamics"><span>Thermostating extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Martínez, Enrique; Cawkwell, Marc J.; Voter, Arthur F.; ...</p> <p>2015-04-21</p> <p>Here, Extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics is developed and analyzed for applications in canonical (NVT) simulations. Three different approaches are considered: the Nosé and Andersen thermostats and Langevin dynamics. We have tested the temperature distribution under different conditions of self-consistent field (SCF) convergence and time step and compared the results to analytical predictions. We find that the simulations based on the extended <span class="hlt">Lagrangian</span> Born-Oppenheimer framework provide accurate canonical distributions even under approximate SCF convergence, often requiring only a single diagonalization per time step, whereas regular Born-Oppenheimer formulations exhibit unphysical fluctuations unless a sufficiently high degree of convergence is reached atmore » each time step. Lastly, the thermostated extended <span class="hlt">Lagrangian</span> framework thus offers an accurate approach to sample processes in the canonical ensemble at a fraction of the computational cost of regular Born-Oppenheimer molecular dynamics simulations.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AdSpR..53..543S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AdSpR..53..543S"><span>Alternative transfer to the Earth-Moon <span class="hlt">Lagrangian</span> points L4 and L5 using lunar gravity assist</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salazar, F. J. T.; Macau, E. E. N.; Winter, O. C.</p> <p>2014-02-01</p> <p><span class="hlt">Lagrangian</span> points L4 and L5 lie at 60° ahead of and behind the Moon in its orbit with respect to the Earth. Each one of them is a third point of an equilateral triangle with the base of the line defined by those two bodies. These <span class="hlt">Lagrangian</span> points are stable for the Earth-Moon <span class="hlt">mass</span> ratio. As so, these <span class="hlt">Lagrangian</span> points represent remarkable positions to host astronomical observatories or space stations. However, this same distance characteristic may be a challenge for periodic servicing mission. This paper studies elliptic trajectories from an Earth circular parking orbit to reach the Moon's sphere of influence and apply a swing-by maneuver in order to re-direct the path of a spacecraft to a vicinity of the <span class="hlt">Lagrangian</span> points L4 and L5. Once the geocentric transfer orbit and the initial impulsive thrust have been determined, the goal is to establish the angle at which the geocentric trajectory crosses the lunar sphere of influence in such a way that when the spacecraft leaves the Moon's gravitational field, its trajectory and velocity with respect to the Earth change in order to the spacecraft arrives at L4 and L5. In this work, the planar Circular Restricted Three Body Problem approximation is used and in order to avoid solving a two boundary problem, the patched-conic approximation is considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960049629','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960049629"><span>Atomization simulations using an Eulerian-VOF-<span class="hlt">Lagrangian</span> method</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chen, Yen-Sen; Shang, Huan-Min; Liaw, Paul; Chen, C. P.</p> <p>1994-01-01</p> <p>This paper summarizes the technical development and validation of a multiphase computational fluid dynamics (CFD) numerical method using the volume-of-fluid (VOF) model and a <span class="hlt">Lagrangian</span> tracking model which can be employed to analyze general multiphase flow problems with free surface mechanism. The gas-liquid interface <span class="hlt">mass</span>, momentum and energy conservations are modeled by continuum surface mechanisms. A new solution method is developed such that the present VOF model can be applied for all-speed flow regimes. The objectives of the present study are to develop and verify the fractional volume-of-fluid cell partitioning approach into a predictor-corrector algorithm and to demonstrate the effectiveness of the present innovative approach by simulating benchmark problems including the coaxial jet atomization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhyD..346...59X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhyD..346...59X"><span>Assimilating Eulerian and <span class="hlt">Lagrangian</span> data in traffic-flow models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xia, Chao; Cochrane, Courtney; DeGuire, Joseph; Fan, Gaoyang; Holmes, Emma; McGuirl, Melissa; Murphy, Patrick; Palmer, Jenna; Carter, Paul; Slivinski, Laura; Sandstede, Björn</p> <p>2017-05-01</p> <p>Data assimilation of traffic flow remains a challenging problem. One difficulty is that data come from different sources ranging from stationary sensors and camera data to GPS and cell phone data from moving cars. Sensors and cameras give information about traffic density, while GPS data provide information about the positions and velocities of individual cars. Previous methods for assimilating <span class="hlt">Lagrangian</span> data collected from individual cars relied on specific properties of the underlying computational model or its reformulation in <span class="hlt">Lagrangian</span> coordinates. These approaches make it hard to assimilate both Eulerian density and <span class="hlt">Lagrangian</span> positional data simultaneously. In this paper, we propose an alternative approach that allows us to assimilate both Eulerian and <span class="hlt">Lagrangian</span> data. We show that the proposed algorithm is accurate and works well in different traffic scenarios and regardless of whether ensemble Kalman or particle filters are used. We also show that the algorithm is capable of estimating parameters and assimilating real traffic observations and synthetic observations obtained from microscopic models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008ACPD....818727S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008ACPD....818727S"><span>Implications of <span class="hlt">Lagrangian</span> transport for coupled chemistry-climate simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stenke, A.; Dameris, M.; Grewe, V.; Garny, H.</p> <p>2008-10-01</p> <p>For the first time a purely <span class="hlt">Lagrangian</span> transport algorithm is applied in a fully coupled chemistry-climate model (CCM). We use the <span class="hlt">Lagrangian</span> scheme ATTILA for the transport of water vapour, cloud water and chemical trace species in the ECHAM4.L39(DLR)/CHEM (E39C) CCM. The advantage of the <span class="hlt">Lagrangian</span> approach is that it is numerically non-diffusive and therefore maintains steeper and more realistic gradients than the operational semi-<span class="hlt">Lagrangian</span> transport scheme. In case of radiatively active species changes in the simulated distributions feed back to model dynamics which in turn affect the modelled transport. The implications of the <span class="hlt">Lagrangian</span> transport scheme for stratospheric model dynamics and tracer distributions in the upgraded model version E39C-ATTILA (E39C-A) are evaluated by comparison with observations and results of the E39C model with the operational semi-<span class="hlt">Lagrangian</span> advection scheme. We find that several deficiencies in stratospheric dynamics in E39C seem to originate from a pronounced modelled wet bias and an associated cold bias in the extra-tropical lowermost stratosphere. The reduction of the simulated moisture and temperature bias in E39C-A leads to a significant advancement of stratospheric dynamics in terms of the mean state as well as annual and interannual variability. As a consequence of the favourable numerical characteristics of the <span class="hlt">Lagrangian</span> transport scheme and the improved model dynamics, E39C-A generally shows more realistic stratospheric tracer distributions: Compared to E39C high stratospheric chlorine (Cly) concentrations extend further downward and agree now well with analyses derived from observations. Therefore E39C-A realistically covers the altitude of maximum ozone depletion in the stratosphere. The location of the ozonopause, i.e. the transition from low tropospheric to high stratospheric ozone values, is also clearly improved in E39C-A. Furthermore, the simulated temporal evolution of stratospheric Cly in the past is</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGP...128..140K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGP...128..140K"><span>Hamiltonian stability for weighted measure and generalized <span class="hlt">Lagrangian</span> mean curvature flow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kajigaya, Toru; Kunikawa, Keita</p> <p>2018-06-01</p> <p>In this paper, we generalize several results for the Hamiltonian stability and the mean curvature flow of <span class="hlt">Lagrangian</span> submanifolds in a Kähler-Einstein manifold to more general Kähler manifolds including a Fano manifold equipped with a Kähler form ω ∈ 2 πc1(M) by using the method proposed by Behrndt (2011). Namely, we first consider a weighted measure on a <span class="hlt">Lagrangian</span> submanifold L in a Kähler manifold M and investigate the variational problem of L for the weighted volume functional. We call a stationary point of the weighted volume functional f-minimal, and define the notion of Hamiltonian f-stability as a local minimizer under Hamiltonian deformations. We show such examples naturally appear in a toric Fano manifold. Moreover, we consider the generalized <span class="hlt">Lagrangian</span> mean curvature flow in a Fano manifold which is introduced by Behrndt and Smoczyk-Wang. We generalize the result of H. Li, and show that if the initial <span class="hlt">Lagrangian</span> submanifold is a small Hamiltonian deformation of an f-minimal and Hamiltonian f-stable <span class="hlt">Lagrangian</span> submanifold, then the generalized MCF converges exponentially fast to an f-minimal <span class="hlt">Lagrangian</span> submanifold.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27327139','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27327139"><span><span class="hlt">Lagrangian</span> descriptors in dissipative systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Junginger, Andrej; Hernandez, Rigoberto</p> <p>2016-11-09</p> <p>The reaction dynamics of time-dependent systems can be resolved through a recrossing-free dividing surface associated with the transition state trajectory-that is, the unique trajectory which is bound to the barrier region for all time in response to a given time-dependent potential. A general procedure based on the minimization of <span class="hlt">Lagrangian</span> descriptors has recently been developed by Craven and Hernandez [Phys. Rev. Lett., 2015, 115, 148301] to construct this particular trajectory without requiring perturbative expansions relative to the naive transition state point at the top of the barrier. The extension of the method to account for dissipation in the equations of motion requires additional considerations established in this paper because the calculation of the <span class="hlt">Lagrangian</span> descriptor involves the integration of trajectories in forward and backward time. The two contributions are in general very different because the friction term can act as a source (in backward time) or sink (in forward time) of energy, leading to the possibility that information about the phase space structure may be lost due to the dominance of only one of the terms. To compensate for this effect, we introduce a weighting scheme within the <span class="hlt">Lagrangian</span> descriptor and demonstrate that for thermal Langevin dynamics it preserves the essential phase space structures, while they are lost in the nonweighted case.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740019118','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740019118"><span>A macroscopic plasma <span class="hlt">Lagrangian</span> and its application to wave interactions and resonances</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Peng, Y. K. M.</p> <p>1974-01-01</p> <p>The derivation of a macroscopic plasma <span class="hlt">Lagrangian</span> is considered, along with its application to the description of nonlinear three-wave interaction in a homogeneous plasma and linear resonance oscillations in a inhomogeneous plasma. One approach to obtain the <span class="hlt">Lagrangian</span> is via the inverse problem of the calculus of variations for arbitrary first and second order quasilinear partial differential systems. Necessary and sufficient conditions for the given equations to be Euler-Lagrange equations of a <span class="hlt">Lagrangian</span> are obtained. These conditions are then used to determine the transformations that convert some classes of non-Euler-Lagrange equations to Euler-Lagrange equation form. The <span class="hlt">Lagrangians</span> for a linear resistive transmission line and a linear warm collisional plasma are derived as examples. Using energy considerations, the correct macroscopic plasma <span class="hlt">Lagrangian</span> is shown to differ from the velocity-integrated low <span class="hlt">Lagrangian</span> by a macroscopic potential energy that equals twice the particle thermal kinetic energy plus the energy lost by heat conduction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JChPh.147e4103N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JChPh.147e4103N"><span>Next generation extended <span class="hlt">Lagrangian</span> first principles molecular dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Niklasson, Anders M. N.</p> <p>2017-08-01</p> <p>Extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics [A. M. N. Niklasson, Phys. Rev. Lett. 100, 123004 (2008)] is formulated for general Hohenberg-Kohn density-functional theory and compared with the extended <span class="hlt">Lagrangian</span> framework of first principles molecular dynamics by Car and Parrinello [Phys. Rev. Lett. 55, 2471 (1985)]. It is shown how extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics overcomes several shortcomings of regular, direct Born-Oppenheimer molecular dynamics, while improving or maintaining important features of Car-Parrinello simulations. The accuracy of the electronic degrees of freedom in extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics, with respect to the exact Born-Oppenheimer solution, is of second-order in the size of the integration time step and of fourth order in the potential energy surface. Improved stability over recent formulations of extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics is achieved by generalizing the theory to finite temperature ensembles, using fractional occupation numbers in the calculation of the inner-product kernel of the extended harmonic oscillator that appears as a preconditioner in the electronic equations of motion. Material systems that normally exhibit slow self-consistent field convergence can be simulated using integration time steps of the same order as in direct Born-Oppenheimer molecular dynamics, but without the requirement of an iterative, non-linear electronic ground-state optimization prior to the force evaluations and without a systematic drift in the total energy. In combination with proposed low-rank and on the fly updates of the kernel, this formulation provides an efficient and general framework for quantum-based Born-Oppenheimer molecular dynamics simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28789552','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28789552"><span>Next generation extended <span class="hlt">Lagrangian</span> first principles molecular dynamics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Niklasson, Anders M N</p> <p>2017-08-07</p> <p>Extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics [A. M. N. Niklasson, Phys. Rev. Lett. 100, 123004 (2008)] is formulated for general Hohenberg-Kohn density-functional theory and compared with the extended <span class="hlt">Lagrangian</span> framework of first principles molecular dynamics by Car and Parrinello [Phys. Rev. Lett. 55, 2471 (1985)]. It is shown how extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics overcomes several shortcomings of regular, direct Born-Oppenheimer molecular dynamics, while improving or maintaining important features of Car-Parrinello simulations. The accuracy of the electronic degrees of freedom in extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics, with respect to the exact Born-Oppenheimer solution, is of second-order in the size of the integration time step and of fourth order in the potential energy surface. Improved stability over recent formulations of extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics is achieved by generalizing the theory to finite temperature ensembles, using fractional occupation numbers in the calculation of the inner-product kernel of the extended harmonic oscillator that appears as a preconditioner in the electronic equations of motion. Material systems that normally exhibit slow self-consistent field convergence can be simulated using integration time steps of the same order as in direct Born-Oppenheimer molecular dynamics, but without the requirement of an iterative, non-linear electronic ground-state optimization prior to the force evaluations and without a systematic drift in the total energy. In combination with proposed low-rank and on the fly updates of the kernel, this formulation provides an efficient and general framework for quantum-based Born-Oppenheimer molecular dynamics simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830044831&hterms=averaged+lagrangian&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Daveraged%2Blagrangian','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830044831&hterms=averaged+lagrangian&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Daveraged%2Blagrangian"><span>Microscopic <span class="hlt">Lagrangian</span> description of warm plasmas. IV - Macroscopic approximation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kim, H.; Crawford, F. W.</p> <p>1983-01-01</p> <p>The averaged-<span class="hlt">Lagrangian</span> method is applied to linear wave propagation and nonlinear three-wave interaction in a warm magnetoplasma, in the macroscopic approximation. The microscopic <span class="hlt">Lagrangian</span> treated by Kim and Crawford (1977) and by Galloway and Crawford (1977) is first expanded to third order in perturbation. Velocity integration is then carried out, before applying Hamilton's principle to obtain a general description of wave propagation and coupling. The results are specialized to the case of interaction between two electron plasma waves and an Alfven wave. The method is shown to be more powerful than the alternative possibility of working from the beginning with a macroscopic <span class="hlt">Lagrangian</span> density.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvF...2e4602S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvF...2e4602S"><span><span class="hlt">Lagrangian</span> acceleration statistics in a turbulent channel flow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stelzenmuller, Nickolas; Polanco, Juan Ignacio; Vignal, Laure; Vinkovic, Ivana; Mordant, Nicolas</p> <p>2017-05-01</p> <p><span class="hlt">Lagrangian</span> acceleration statistics in a fully developed turbulent channel flow at Reτ=1440 are investigated, based on tracer particle tracking in experiments and direct numerical simulations. The evolution with wall distance of the <span class="hlt">Lagrangian</span> velocity and acceleration time scales is analyzed. Dependency between acceleration components in the near-wall region is described using cross-correlations and joint probability density functions. The strong streamwise coherent vortices typical of wall-bounded turbulent flows are shown to have a significant impact on the dynamics. This results in a strong anisotropy at small scales in the near-wall region that remains present in most of the channel. Such statistical properties may be used as constraints in building advanced <span class="hlt">Lagrangian</span> stochastic models to predict the dispersion and mixing of chemical components for combustion or environmental studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhRvA..81b2112K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhRvA..81b2112K"><span>Functional integral for non-<span class="hlt">Lagrangian</span> systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kochan, Denis</p> <p>2010-02-01</p> <p>A functional integral formulation of quantum mechanics for non-<span class="hlt">Lagrangian</span> systems is presented. The approach, which we call “stringy quantization,” is based solely on classical equations of motion and is free of any ambiguity arising from <span class="hlt">Lagrangian</span> and/or Hamiltonian formulation of the theory. The functionality of the proposed method is demonstrated on several examples. Special attention is paid to the stringy quantization of systems with a general A-power friction force -κq˙A. Results for A=1 are compared with those obtained in the approaches by Caldirola-Kanai, Bateman, and Kostin. Relations to the Caldeira-Leggett model and to the Feynman-Vernon approach are discussed as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvD..95b5017K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvD..95b5017K"><span>Effective <span class="hlt">Lagrangian</span> in de Sitter spacetime</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kitamoto, Hiroyuki; Kitazawa, Yoshihisa</p> <p>2017-01-01</p> <p>Scale invariant fluctuations of metric are a universal feature of quantum gravity in de Sitter spacetime. We construct an effective <span class="hlt">Lagrangian</span> which summarizes their implications on local physics by integrating superhorizon metric fluctuations. It shows infrared quantum effects are local and render fundamental couplings time dependent. We impose Lorenz invariance on the effective <span class="hlt">Lagrangian</span> as it is required by the principle of general covariance. We show that such a requirement leads to unique physical predictions by fixing the quantization ambiguities. We explain how the gauge parameter dependence of observables is canceled. In particular the relative evolution speed of the couplings are shown to be gauge invariant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009IJMPA..24.5319K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009IJMPA..24.5319K"><span>Quantization of Non-<span class="hlt">Lagrangian</span> Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kochan, Denis</p> <p></p> <p>A novel method for quantization of non-<span class="hlt">Lagrangian</span> (open) systems is proposed. It is argued that the essential object, which provides both classical and quantum evolution, is a certain canonical two-form defined in extended velocity space. In this setting classical dynamics is recovered from the stringy-type variational principle, which employs umbilical surfaces instead of histories of the system. Quantization is then accomplished in accordance with the introduced variational principle. The path integral for the transition probability amplitude (propagator) is rearranged to a surface functional integral. In the standard case of closed (<span class="hlt">Lagrangian</span>) systems the presented method reduces to the standard Feynman's approach. The inverse problem of the calculus of variation, the problem of quantization ambiguity and the quantum mechanics in the presence of friction are analyzed in detail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhyA..471..540S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhyA..471..540S"><span>The S-<span class="hlt">Lagrangian</span> and a theory of homeostasis in living systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sandler, U.; Tsitolovsky, L.</p> <p>2017-04-01</p> <p>A major paradox of living things is their ability to actively counteract degradation in a continuously changing environment or being injured through homeostatic protection. In this study, we propose a dynamic theory of homeostasis based on a generalized <span class="hlt">Lagrangian</span> approach (S-<span class="hlt">Lagrangian</span>), which can be equally applied to physical and nonphysical systems. Following discoverer of homeostasis Cannon (1935), we assume that homeostasis results from tendency of the organisms to decrease of the stress and avoid of death. We show that the universality of homeostasis is a consequence of analytical properties of the S-<span class="hlt">Lagrangian</span>, while peculiarities of the biochemical and physiological mechanisms of homeostasis determine phenomenological parameters of the S-<span class="hlt">Lagrangian</span>. Additionally, we reveal that plausible assumptions about S-<span class="hlt">Lagrangian</span> features lead to good agreement between theoretical descriptions and observed homeostatic behavior. Here, we have focused on homeostasis of living systems, however, the proposed theory is also capable of being extended to social systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012MeSol..47..137K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012MeSol..47..137K"><span>Forms of null <span class="hlt">Lagrangians</span> in field theories of continuum mechanics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kovalev, V. A.; Radaev, Yu. N.</p> <p>2012-02-01</p> <p>The divergence representation of a null <span class="hlt">Lagrangian</span> that is regular in a star-shaped domain is used to obtain its general expression containing field gradients of order ≤ 1 in the case of spacetime of arbitrary dimension. It is shown that for a static three-component field in the three-dimensional space, a null <span class="hlt">Lagrangian</span> can contain up to 15 independent elements in total. The general form of a null <span class="hlt">Lagrangian</span> in the four-dimensional Minkowski spacetime is obtained (the number of physical field variables is assumed arbitrary). A complete theory of the null <span class="hlt">Lagrangian</span> for the n-dimensional spacetime manifold (including the four-dimensional Minkowski spacetime as a special case) is given. Null <span class="hlt">Lagrangians</span> are then used as a basis for solving an important variational problem of an integrating factor. This problem involves searching for factors that depend on the spacetime variables, field variables, and their gradients and, for a given system of partial differential equations, ensure the equality between the scalar product of a vector multiplier by the system vector and some divergence expression for arbitrary field variables and, hence, allow one to formulate a divergence conservation law on solutions to the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhLB..779..485L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhLB..779..485L"><span>A unifying framework for ghost-free Lorentz-invariant <span class="hlt">Lagrangian</span> field theories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Wenliang</p> <p>2018-04-01</p> <p>We propose a framework for Lorentz-invariant <span class="hlt">Lagrangian</span> field theories where Ostrogradsky's scalar ghosts could be absent. A key ingredient is the generalized Kronecker delta. The general <span class="hlt">Lagrangians</span> are reformulated in the language of differential forms. The absence of higher order equations of motion for the scalar modes stems from the basic fact that every exact form is closed. The well-established <span class="hlt">Lagrangian</span> theories for spin-0, spin-1, p-form, spin-2 fields have natural formulations in this framework. We also propose novel building blocks for <span class="hlt">Lagrangian</span> field theories. Some of them are novel nonlinear derivative terms for spin-2 fields. It is nontrivial that Ostrogradsky's scalar ghosts are absent in these fully nonlinear theories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvD..97f5019R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvD..97f5019R"><span>Leading-order classical <span class="hlt">Lagrangians</span> for the nonminimal standard-model extension</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reis, J. A. A. S.; Schreck, M.</p> <p>2018-03-01</p> <p>In this paper, we derive the general leading-order classical <span class="hlt">Lagrangian</span> covering all fermion operators of the nonminimal standard-model extension (SME). Such a <span class="hlt">Lagrangian</span> is considered to be the point-particle analog of the effective field theory description of Lorentz violation that is provided by the SME. At leading order in Lorentz violation, the <span class="hlt">Lagrangian</span> obtained satisfies the set of five nonlinear equations that govern the map from the field theory to the classical description. This result can be of use for phenomenological studies of classical bodies in gravitational fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......114R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......114R"><span><span class="hlt">Lagrangian</span> Fluid Element Tracking and Estimation of Local Displacement Speeds in Turbulent Premixed Flames</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramji, Sarah Ann</p> <p></p> <p>Improved understanding of turbulence-flame interactions in premixed combustion can be achieved using fully 3D time-resolved multi-kHz multi-scalar experimental measurements. These interactions may be represented by the evolution of various <span class="hlt">Lagrangian</span> quantities described by theoretical <span class="hlt">Lagrangian</span> Fluid Elements (LFEs). The data used in this work came from two experimental campaigns that used simultaneous T-PIV and OH/CH2O PLIF, at Sandia National Labs and the Air Force Research Lab at Wright-Patterson. In this thesis, an algorithm to accurately track LFEs through this 4D experimental space has been developed and verified by cross-correlation with the T-PIV seed particle fields. A novel method to measure the local instantaneous displacement speed in 3D has been developed, using this algorithm to track control <span class="hlt">masses</span> of fluid that interact with the flame front. Statistics of the displacement speed have been presented, and the effects of local turbulence and flame topological properties on the displacement speed have been studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017WRR....53.3513E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017WRR....53.3513E"><span><span class="hlt">Lagrangian</span> simulation of mixing and reactions in complex geochemical systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Engdahl, Nicholas B.; Benson, David A.; Bolster, Diogo</p> <p>2017-04-01</p> <p>Simulations of detailed geochemical systems have traditionally been restricted to Eulerian reactive transport algorithms. This note introduces a <span class="hlt">Lagrangian</span> method for modeling multicomponent reaction systems. The approach uses standard random walk-based methods for the particle motion steps but allows the particles to interact with each other by exchanging <span class="hlt">mass</span> of their various chemical species. The colocation density of each particle pair is used to calculate the <span class="hlt">mass</span> transfer rate, which creates a local disequilibrium that is then relaxed back toward equilibrium using the reaction engine PhreeqcRM. The <span class="hlt">mass</span> exchange is the only step where the particles interact and the remaining transport and reaction steps are entirely independent for each particle. Several validation examples are presented, which reproduce well-known analytical solutions. These are followed by two demonstration examples of a competitive decay chain and an acid-mine drainage system. The source code, entitled Complex Reaction on Particles (CRP), and files needed to run these examples are hosted openly on GitHub (https://github.com/nbengdahl/CRP), so as to enable interested readers to readily apply this approach with minimal modifications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999IAUS..183..242A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999IAUS..183..242A"><span>The <span class="hlt">Mass</span> Function of Cosmic Structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Audit, E.; Teyssier, R.; Alimi, J.-M.</p> <p></p> <p>We investigate some modifications to the Press and Schechter (1974) (PS) prescription resulting from shear and tidal effects. These modifications rely on more realistic treatments of the collapse process than the standard approach based on the spherical model. First, we show that the <span class="hlt">mass</span> function resulting from a new approximate <span class="hlt">Lagrangian</span> dynamic (Audit and Alimi, A&A 1996), contains more objects at high <span class="hlt">mass</span>, than the classical PS <span class="hlt">mass</span> function and is well fitted by a PS-like function with a threshold density of deltac ≍ 1.4. However, such a <span class="hlt">Lagrangian</span> description can underestimate the epoch of structure formation since it defines it as the collapse of the first principal axis. We therefore suggest some analytical prescriptions, for computing the collapse time along the second and third principal axes, and we deduce the corresponding <span class="hlt">mass</span> functions. The collapse along the third axis is delayed by the shear and the number of objects of high <span class="hlt">mass</span> then decreases. Finally, we show that the shear also strongly affects the formation of low-<span class="hlt">mass</span> halos. This dynamical effect implies a modification of the low-<span class="hlt">mass</span> slope of the <span class="hlt">mass</span> function and allows the reproduction of the observed luminosity function of field galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810057814&hterms=averaged+lagrangian&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Daveraged%2Blagrangian','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810057814&hterms=averaged+lagrangian&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Daveraged%2Blagrangian"><span><span class="hlt">Lagrangian</span> methods in nonlinear plasma wave interaction</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Crawford, F. W.</p> <p>1980-01-01</p> <p>Analysis of nonlinear plasma wave interactions is usually very complicated, and simplifying mathematical approaches are highly desirable. The application of averaged-<span class="hlt">Lagrangian</span> methods offers a considerable reduction in effort, with improved insight into synchronism and conservation (Manley-Rowe) relations. This chapter indicates how suitable <span class="hlt">Lagrangian</span> densities have been defined, expanded, and manipulated to describe nonlinear wave-wave and wave-particle interactions in the microscopic, macroscopic and cold plasma models. Recently, further simplifications have been introduced by the use of techniques derived from Lie algebra. These and likely future developments are reviewed briefly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012CSR....47..145F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012CSR....47..145F"><span>Using <span class="hlt">Lagrangian</span> Coherent Structures to understand coastal water quality</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fiorentino, L. A.; Olascoaga, M. J.; Reniers, A.; Feng, Z.; Beron-Vera, F. J.; MacMahan, J. H.</p> <p>2012-09-01</p> <p>The accumulation of pollutants near the shoreline can result in low quality coastal water with negative effects on human health. To understand the role of mixing by tidal flows in coastal water quality we study the nearshore <span class="hlt">Lagrangian</span> circulation. Specifically, we reveal <span class="hlt">Lagrangian</span> Coherent Structures (LCSs), i.e., distinguished material curves which shape global mixing patterns and thus act as skeletons of the <span class="hlt">Lagrangian</span> circulation. This is done using the recently developed geodesic theory of transport barriers. Particular focus is placed on Hobie Beach, a recreational subtropical marine beach located in Virginia Key, Miami, Florida. According to studies of water quality, Hobie Beach is characterized by high microbial levels. Possible sources of pollution in Hobie Beach include human bather shedding, dog fecal matter, runoff, and sand efflux at high tides. Consistent with the patterns formed by satellite-tracked drifter trajectories, the LCSs extracted from simulated currents reveal a <span class="hlt">Lagrangian</span> circulation favoring the retention near the shoreline of pollutants released along the shoreline, which can help explain the low quality water registered at Hobie Beach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NuPhB.928..107M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NuPhB.928..107M"><span>Integration over families of <span class="hlt">Lagrangian</span> submanifolds in BV formalism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mikhailov, Andrei</p> <p>2018-03-01</p> <p>Gauge fixing is interpreted in BV formalism as a choice of <span class="hlt">Lagrangian</span> submanifold in an odd symplectic manifold (the BV phase space). A natural construction defines an integration procedure on families of <span class="hlt">Lagrangian</span> submanifolds. In string perturbation theory, the moduli space integrals of higher genus amplitudes can be interpreted in this way. We discuss the role of gauge symmetries in this construction. We derive the conditions which should be imposed on gauge symmetries for the consistency of our integration procedure. We explain how these conditions behave under the deformations of the worldsheet theory. In particular, we show that integrated vertex operator is actually an inhomogeneous differential form on the space of <span class="hlt">Lagrangian</span> submanifolds.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JCoPh.348..493T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JCoPh.348..493T"><span>An updated <span class="hlt">Lagrangian</span> particle hydrodynamics (ULPH) for Newtonian fluids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tu, Qingsong; Li, Shaofan</p> <p>2017-11-01</p> <p>In this work, we have developed an updated <span class="hlt">Lagrangian</span> particle hydrodynamics (ULPH) for Newtonian fluid. Unlike the smoothed particle hydrodynamics, the non-local particle hydrodynamics formulation proposed here is consistent and convergence. Unlike the state-based peridynamics, the discrete particle dynamics proposed here has no internal material bond between particles, and it is not formulated with respect to initial or a fixed referential configuration. In specific, we have shown that (1) the non-local update <span class="hlt">Lagrangian</span> particle hydrodynamics formulation converges to the conventional local fluid mechanics formulation; (2) the non-local updated <span class="hlt">Lagrangian</span> particle hydrodynamics can capture arbitrary flow discontinuities without any changes in the formulation, and (3) the proposed non-local particle hydrodynamics is computationally efficient and robust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=magnetic+AND+particles&id=EJ832524','ERIC'); return false;" href="https://eric.ed.gov/?q=magnetic+AND+particles&id=EJ832524"><span>Symmetries in <span class="hlt">Lagrangian</span> Dynamics</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ferrario, Carlo; Passerini, Arianna</p> <p>2007-01-01</p> <p>In the framework of Noether's theorem, a distinction between <span class="hlt">Lagrangian</span> and dynamical symmetries is made, in order to clarify some aspects neglected by textbooks. An intuitive setting of the concept of invariance of differential equations is presented. The analysis is completed by deriving the symmetry properties in the motion of a charged…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ACPD...1013407K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ACPD...1013407K"><span>Characterizing aerosol transport into the Canadian High Arctic using aerosol <span class="hlt">mass</span> spectrometry and <span class="hlt">Lagrangian</span> modelling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuhn, T.; Damoah, R.; Bacak, A.; Sloan, J. J.</p> <p>2010-05-01</p> <p>We report the analysis of measurements made using an aerosol <span class="hlt">mass</span> spectrometer (AMS; Aerodyne Research Inc.) that was installed in the Polar Environment Atmospheric Research Laboratory (PEARL) in summer 2006. PEARL is located in the Canadian high Arctic at 610 m above sea level on Ellesmere Island (80° N 86° W). PEARL is unique for its remote location in the Arctic and because most of the time it is situated within the free troposphere. It is therefore well suited as a receptor site to study the long range tropospheric transport of pollutants into the Arctic. Some information about the successful year-round operation of an AMS at a high Arctic site such as PEARL will be reported here, together with design considerations for reliable sampling under harsh low-temperature conditions. Computational fluid dynamics calculations were made to ensure that sample integrity was maintained while sampling air at temperatures that average -40 °C in the winter and can be as low as -55 °C. Selected AMS measurements of aerosol <span class="hlt">mass</span> concentration, size, and chemical composition recorded during the months of August, September and October 2006 will be reported. During this period, sulfate was at most times the predominant aerosol component with on average 0.115 μg m-3 (detection limit 0.003 μg m-3). The second most abundant component was undifferentiated organic aerosol, with on average 0.11 μg m-3 detection limit (0.04 μg m-3). The nitrate component, which averaged 0.007 μg m-3, was above its detection limit (0.002 μg m-3), whereas the ammonium ion had an apparent average concentration of 0.02 μg m-3, which was approximately equal to its detection limit. A few episodes having increased <span class="hlt">mass</span> concentrations and lasting from several hours to several days are apparent in the data. These were investigated further using a statistical analysis to determine their common characteristics. High correlations among some of the components arriving during the short term episodes provide</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFMNG42A0407P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFMNG42A0407P"><span>Predictability of the <span class="hlt">Lagrangian</span> Motion in the Upper Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Piterbarg, L. I.; Griffa, A.; Griffa, A.; Mariano, A. J.; Ozgokmen, T. M.; Ryan, E. H.</p> <p>2001-12-01</p> <p>The complex non-linear dynamics of the upper ocean leads to chaotic behavior of drifter trajectories in the ocean. Our study is focused on estimating the predictability limit for the position of an individual <span class="hlt">Lagrangian</span> particle or a particle cluster based on the knowledge of mean currents and observations of nearby particles (predictors). The <span class="hlt">Lagrangian</span> prediction problem, besides being a fundamental scientific problem, is also of great importance for practical applications such as search and rescue operations and for modeling the spread of fish larvae. A stochastic multi-particle model for the <span class="hlt">Lagrangian</span> motion has been rigorously formulated and is a generalization of the well known "random flight" model for a single particle. Our model is mathematically consistent and includes a few easily interpreted parameters, such as the <span class="hlt">Lagrangian</span> velocity decorrelation time scale, the turbulent velocity variance, and the velocity decorrelation radius, that can be estimated from data. The top Lyapunov exponent for an isotropic version of the model is explicitly expressed as a function of these parameters enabling us to approximate the predictability limit to first order. <span class="hlt">Lagrangian</span> prediction errors for two new prediction algorithms are evaluated against simple algorithms and each other and are used to test the predictability limits of the stochastic model for isotropic turbulence. The first algorithm is based on a Kalman filter and uses the developed stochastic model. Its implementation for drifter clusters in both the Tropical Pacific and Adriatic Sea, showed good prediction skill over a period of 1-2 weeks. The prediction error is primarily a function of the data density, defined as the number of predictors within a velocity decorrelation spatial scale from the particle to be predicted. The second algorithm is model independent and is based on spatial regression considerations. Preliminary results, based on simulated, as well as, real data, indicate that it performs</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1913672M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1913672M"><span>Three dimensional <span class="hlt">Lagrangian</span> structures in the Antarctic Polar Vortex.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mancho, Ana M.; Garcia-Garrido, Victor J.; Curbelo, Jezabel; Niang, Coumba; Mechoso, Carlos R.; Wiggins, Stephen</p> <p>2017-04-01</p> <p>Dynamical systems theory has supported the description of transport processes in fluid dynamics. For understanding trajectory patterns in chaotic advection the geometrical approach by Poincaré seeks for spatial structures that separate regions corresponding to qualitatively different types of trajectories. These structures have been referred to as <span class="hlt">Lagrangian</span> Coherent Structures (LCS), which typically in geophysical flows are well described under the approach of incompressible 2D flows. Different tools have been used to visualize LCS. In this presentation we use <span class="hlt">Lagrangian</span> Descriptors [1,2,3,4] (function M) for visualizing 3D <span class="hlt">Lagrangian</span> structures in the atmosphere, in particular in the Antarctic Polar Vortex. The function M is computed in a fully 3D incompressible flow obtained from data provided by the European Centre for Medium-Range Weather Forecast and it is represented in 2D surfaces. We discuss the findings during the final warming that took place in the spring of 1979 [5]. This research is supported by MINECO grant MTM2014-56392-R. Support is acknowledged also from CSIC grant COOPB20265, U.S. NSF grant AGS-1245069 and ONR grant No. N00014- 01-1-0769. C. Niang acknowledges Fundacion Mujeres por Africa and ICMAT Severo Ochoa project SEV-2011-0087 for financial support. [1] C. Mendoza, A. M. Mancho. The hidden geometry of ocean flows. Physical Review Letters 105 (2010), 3, 038501-1-038501-4. [2] A. M. Mancho, S. Wiggins, J. Curbelo, C. Mendoza. <span class="hlt">Lagrangian</span> Descriptors: A Method for Revealing Phase Space Structures of General Time Dependent Dynamical Systems. Communications in Nonlinear Science and Numerical Simulation. 18 (2013) 3530-3557. [3] C. Lopesino, F. Balibrea-Iniesta, S. Wiggins and A. M. Mancho. <span class="hlt">Lagrangian</span> descriptors for two dimensional, area preserving autonomous and nonautonomous maps. Communications in Nonlinear Science and Numerical Simulations, 27 (2015) (1-3), 40-51. [4] C. Lopesino, F. Balibrea-Iniesta, V. J. García-Garrido, S. Wiggins, and A</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DFDH23005V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DFDH23005V"><span>Estimates of <span class="hlt">Lagrangian</span> particle transport by wave groups: forward transport by Stokes drift and backward transport by the return flow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van den Bremer, Ton S.; Taylor, Paul H.</p> <p>2014-11-01</p> <p>Although the literature has examined Stokes drift, the net <span class="hlt">Lagrangian</span> transport by particles due to of surface gravity waves, in great detail, the motion of fluid particles transported by surface gravity wave groups has received considerably less attention. In practice nevertheless, the wave field on the open sea often has a group-like structure. The motion of particles is different, as particles at sufficient depth are transported backwards by the Eulerian return current that was first described by Longuet-Higgins & Stewart (1962) and forms an inseparable counterpart of Stokes drift for wave groups ensuring the (irrotational) <span class="hlt">mass</span> balance holds. We use WKB theory to study the variation of the <span class="hlt">Lagrangian</span> transport by the return current with depth distinguishing two-dimensional seas, three-dimensional seas, infinite depth and finite depth. We then provide dimensional estimates of the net horizontal <span class="hlt">Lagrangian</span> transport by the Stokes drift on the one hand and the return flow on the other hand for realistic sea states in all four cases. Finally we propose a simple scaling relationship for the transition depth: the depth above which <span class="hlt">Lagrangian</span> particles are transported forwards by the Stokes drift and below which such particles are transported backwards by the return current.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29051631','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29051631"><span>Acoustic streaming: an arbitrary <span class="hlt">Lagrangian</span>-Eulerian perspective.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nama, Nitesh; Huang, Tony Jun; Costanzo, Francesco</p> <p>2017-08-25</p> <p>We analyse acoustic streaming flows using an arbitrary <span class="hlt">Lagrangian</span> Eulerian (ALE) perspective. The formulation stems from an explicit separation of time scales resulting in two subproblems: a first-order problem, formulated in terms of the fluid displacement at the fast scale, and a second-order problem, formulated in terms of the <span class="hlt">Lagrangian</span> flow velocity at the slow time scale. Following a rigorous time-averaging procedure, the second-order problem is shown to be intrinsically steady, and with exact boundary conditions at the oscillating walls. Also, as the second-order problem is solved directly for the <span class="hlt">Lagrangian</span> velocity, the formulation does not need to employ the notion of Stokes drift, or any associated post-processing, thus facilitating a direct comparison with experiments. Because the first-order problem is formulated in terms of the displacement field, our formulation is directly applicable to more complex fluid-structure interaction problems in microacoustofluidic devices. After the formulation's exposition, we present numerical results that illustrate the advantages of the formulation with respect to current approaches.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006CompM..38..294A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006CompM..38..294A"><span>Fractional Step Like Schemes for Free Surface Problems with Thermal Coupling Using the <span class="hlt">Lagrangian</span> PFEM</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aubry, R.; Oñate, E.; Idelsohn, S. R.</p> <p>2006-09-01</p> <p>The method presented in Aubry et al. (Comput Struc 83:1459-1475, 2005) for the solution of an incompressible viscous fluid flow with heat transfer using a fully <span class="hlt">Lagrangian</span> description of motion is extended to three dimensions (3D) with particular emphasis on <span class="hlt">mass</span> conservation. A modified fractional step (FS) based on the pressure Schur complement (Turek 1999), and related to the class of algebraic splittings Quarteroni et al. (Comput Methods Appl Mech Eng 188:505-526, 2000), is used and a new advantage of the splittings of the equations compared with the classical FS is highlighted for free surface problems. The temperature is semi-coupled with the displacement, which is the main variable in a <span class="hlt">Lagrangian</span> description. Comparisons for various mesh Reynolds numbers are performed with the classical FS, an algebraic splitting and a monolithic solution, in order to illustrate the behaviour of the Uzawa operator and the <span class="hlt">mass</span> conservation. As the classical fractional step is equivalent to one iteration of the Uzawa algorithm performed with a standard Laplacian as a preconditioner, it will behave well only in a Reynold mesh number domain where the preconditioner is efficient. Numerical results are provided to assess the superiority of the modified algebraic splitting to the classical FS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhyD..372...31B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhyD..372...31B"><span>Generalized <span class="hlt">Lagrangian</span> coherent structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Balasuriya, Sanjeeva; Ouellette, Nicholas T.; Rypina, Irina I.</p> <p>2018-06-01</p> <p>The notion of a <span class="hlt">Lagrangian</span> Coherent Structure (LCS) is by now well established as a way to capture transient coherent transport dynamics in unsteady and aperiodic fluid flows that are known over finite time. We show that the concept of an LCS can be generalized to capture coherence in other quantities of interest that are transported by, but not fully locked to, the fluid. Such quantities include those with dynamic, biological, chemical, or thermodynamic relevance, such as temperature, pollutant concentration, vorticity, kinetic energy, plankton density, and so on. We provide a conceptual framework for identifying the Generalized <span class="hlt">Lagrangian</span> Coherent Structures (GLCSs) associated with such evolving quantities. We show how LCSs can be seen as a special case within this framework, and provide an overarching discussion of various methods for identifying LCSs. The utility of this more general viewpoint is highlighted through a variety of examples. We also show that although LCSs approximate GLCSs in certain limiting situations under restrictive assumptions on how the velocity field affects the additional quantities of interest, LCSs are not in general sufficient to describe their coherent transport.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22314896-second-order-symmetry-preserving-conservative-lagrangian-scheme-compressible-euler-equations-two-dimensional-cylindrical-coordinates','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22314896-second-order-symmetry-preserving-conservative-lagrangian-scheme-compressible-euler-equations-two-dimensional-cylindrical-coordinates"><span>Second order symmetry-preserving conservative <span class="hlt">Lagrangian</span> scheme for compressible Euler equations in two-dimensional cylindrical coordinates</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Cheng, Juan, E-mail: cheng_juan@iapcm.ac.cn; Shu, Chi-Wang, E-mail: shu@dam.brown.edu</p> <p></p> <p>In applications such as astrophysics and inertial confinement fusion, there are many three-dimensional cylindrical-symmetric multi-material problems which are usually simulated by <span class="hlt">Lagrangian</span> schemes in the two-dimensional cylindrical coordinates. For this type of simulation, a critical issue for the schemes is to keep spherical symmetry in the cylindrical coordinate system if the original physical problem has this symmetry. In the past decades, several <span class="hlt">Lagrangian</span> schemes with such symmetry property have been developed, but all of them are only first order accurate. In this paper, we develop a second order cell-centered <span class="hlt">Lagrangian</span> scheme for solving compressible Euler equations in cylindrical coordinates, basedmore » on the control volume discretizations, which is designed to have uniformly second order accuracy and capability to preserve one-dimensional spherical symmetry in a two-dimensional cylindrical geometry when computed on an equal-angle-zoned initial grid. The scheme maintains several good properties such as conservation for <span class="hlt">mass</span>, momentum and total energy, and the geometric conservation law. Several two-dimensional numerical examples in cylindrical coordinates are presented to demonstrate the good performance of the scheme in terms of accuracy, symmetry, non-oscillation and robustness. The advantage of higher order accuracy is demonstrated in these examples.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27575211','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27575211"><span>Influence of compressibility on the <span class="hlt">Lagrangian</span> statistics of vorticity-strain-rate interactions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Danish, Mohammad; Sinha, Sawan Suman; Srinivasan, Balaji</p> <p>2016-07-01</p> <p>The objective of this study is to investigate the influence of compressibility on <span class="hlt">Lagrangian</span> statistics of vorticity and strain-rate interactions. The <span class="hlt">Lagrangian</span> statistics are extracted from "almost" time-continuous data sets of direct numerical simulations of compressible decaying isotropic turbulence by employing a cubic spline-based <span class="hlt">Lagrangian</span> particle tracker. We study the influence of compressibility on <span class="hlt">Lagrangian</span> statistics of alignment in terms of compressibility parameters-turbulent Mach number, normalized dilatation-rate, and flow topology. In comparison to incompressible turbulence, we observe that the presence of compressibility in a flow field weakens the alignment tendency of vorticity toward the largest strain-rate eigenvector. Based on the <span class="hlt">Lagrangian</span> statistics of alignment conditioned on dilatation and topology, we find that the weakened tendency of alignment observed in compressible turbulence is because of a special group of fluid particles that have an initially negligible dilatation-rate and are associated with stable-focus-stretching topology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUSM.A34A..01S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUSM.A34A..01S"><span>Implications of <span class="hlt">Lagrangian</span> Tracer Transport for Coupled Chemistry-Climate Simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stenke, A.</p> <p>2009-05-01</p> <p>Today's coupled chemistry-climate models (CCM) consider a large number of trace species and feedback processes. Due to the radiative effect of some species, errors in simulated tracer distributions can feed back to model dynamics. Thus, shortcomings of the applied transport schemes can have severe implications for the overall model performance. Traditional Eulerian approaches show a satisfactory performance in case of homogeneously distributed trace species, but they can lead to severe problems when applied to highly inhomogeneous tracer distributions. In case of sharp gradients many schemes show a considerable numerical diffusion. <span class="hlt">Lagrangian</span> approaches, on the other hand, combine a number of favourable numerical properties: They are strictly <span class="hlt">mass</span>-conserving and do not suffer from numerical diffusion. Therefore they are able to maintain steeper gradients. A further advantage is that they allow the transport of a large number of tracers without being prohibitively expensive. A variety of benefits for stratospheric dynamics and chemistry resulting from a <span class="hlt">Lagrangian</span> transport algorithm are demonstrated by the example of the CCM E39C. In an updated version of E39C, called E39C-A, the operational semi-<span class="hlt">Lagrangian</span> advection scheme has been replaced with the purely <span class="hlt">Lagrangian</span> scheme ATTILA. It will be shown that several model deficiencies can be cured by the choice of an appropriate transport algorithm. The most important advancement concerns the reduction of a pronounced wet bias in the extra- tropical lowermost stratosphere. In turn, the associated temperature error ("cold bias") is significantly reduced. Stratospheric wind variations are now in better agreement with observations, e.g. E39C-A is able to reproduce the stratospheric wind reversal in the Southern Hemisphere in summer which was not captured by the previous model version. Resulting changes in wave propagation and dissipation lead to a weakening of the simulated mean meridional circulation and therefore a more</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ACPD....6.1915C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ACPD....6.1915C"><span>A <span class="hlt">Lagrangian</span> analysis of the impact of transport and transformation on the ozone stratification observed in the free troposphere during the ESCOMPTE campaign</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Colette, A.; Ancellet, G.; Menut, L.; Arnold, S. R.</p> <p>2006-03-01</p> <p>The ozone variability observed by tropospheric ozone lidars during the ESCOMPTE campaign is analyzed by means of a hybrid-<span class="hlt">Lagrangian</span> modeling study. Transport processes responsible for the formation of ozone-rich layers are identified using a semi-<span class="hlt">Lagrangian</span> analysis of mesoscale simulations to identify the planetary boundary layer (PBL) footprint in the free troposphere. High ozone concentrations are related to polluted air <span class="hlt">masses</span> exported from the Iberian PBL. The chemical composition of air <span class="hlt">masses</span> coming from the PBL and transported in the free troposphere is evaluated using a <span class="hlt">Lagrangian</span> chemistry model. The initial concentrations are provided by a model of chemistry and transport. Different scenarios are tested for the initial conditions and for the impact of mixing with background air in order to perform a quantitative comparison with the lidar observations. For this meteorological situation, the characteristic mixing time is of the order of 2 to 5 days depending on the initial conditions. Ozone is produced in the free troposphere within most air <span class="hlt">masses</span> exported from the Iberian PBL at an average rate of 0.2 ppbv h-1, with a maximum ozone production of 0.4 ppbv h-1. Transport processes from the PBL are responsible for an increase of 13.3 ppbv of ozone concentrations in the free troposphere compared to background levels; about 45% of this increase is attributed to in situ production during the transport rather than direct export of ozone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ACP.....6.3487C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ACP.....6.3487C"><span>A <span class="hlt">Lagrangian</span> analysis of the impact of transport and transformation on the ozone stratification observed in the free troposphere during the ESCOMPTE campaign</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Colette, A.; Ancellet, G.; Menut, L.; Arnold, S. R.</p> <p>2006-08-01</p> <p>The ozone variability observed by tropospheric ozone lidars during the ESCOMPTE campaign is analyzed by means of a hybrid-<span class="hlt">Lagrangian</span> modeling study. Transport processes responsible for the formation of ozone-rich layers are identified using a semi-<span class="hlt">Lagrangian</span> analysis of mesoscale simulations to identify the planetary boundary layer (PBL) footprint in the free troposphere. High ozone concentrations are related to polluted air <span class="hlt">masses</span> exported from the Iberian PBL. The chemical composition of air <span class="hlt">masses</span> coming from the PBL and transported in the free troposphere is evaluated using a <span class="hlt">Lagrangian</span> chemistry model. The initial concentrations are provided by a model of chemistry and transport. Different scenarios are tested for the initial conditions and for the impact of mixing with background air in order to perform a quantitative comparison with the lidar observations. For this meteorological situation, the characteristic mixing time is of the order of 2 to 6 days depending on the initial conditions. Ozone is produced in the free troposphere within most air <span class="hlt">masses</span> exported from the Iberian PBL at an average rate of 0.2 ppbv h-1, with a maximum ozone production of 0.4 ppbv h-1. Transport processes from the PBL are responsible for an increase of 13.3 ppbv of ozone concentrations in the free troposphere compared to background levels; about 45% of this increase is attributed to in situ production during the transport rather than direct export of ozone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1184028-generalized-extended-lagrangian-born-oppenheimer-molecular-dynamics','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1184028-generalized-extended-lagrangian-born-oppenheimer-molecular-dynamics"><span>Generalized extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Niklasson, Anders M. N.; Cawkwell, Marc J.</p> <p>2014-10-29</p> <p>Extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics based on Kohn-Sham density functional theory is generalized in the limit of vanishing self-consistent field optimization prior to the force evaluations. The equations of motion are derived directly from the extended <span class="hlt">Lagrangian</span> under the condition of an adiabatic separation between the nuclear and the electronic degrees of freedom. We show how this separation is automatically fulfilled and system independent. The generalized equations of motion require only one diagonalization per time step and are applicable to a broader range of materials with improved accuracy and stability compared to previous formulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930039947&hterms=sing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsing','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930039947&hterms=sing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsing"><span><span class="hlt">Lagrangian</span> solution of supersonic real gas flows</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Loh, Ching-Yuen; Liou, Meng-Sing</p> <p>1993-01-01</p> <p>The present extention of a <span class="hlt">Lagrangian</span> approach of the Riemann solution procedure, which was originally proposed for perfect gases, to real gases, is nontrivial and requires the development of an exact real-gas Riemann solver for the <span class="hlt">Lagrangian</span> form of the conservation laws. Calculations including complex wave interactions of various types were conducted to test the accuracy and robustness of the approach. Attention is given to the case of 2D oblique waves' capture, where a slip line is clearly in evidence; the real gas effect is demonstrated in the case of a generic engine nozzle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26274277','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26274277"><span>Intermittent <span class="hlt">Lagrangian</span> velocities and accelerations in three-dimensional porous medium flow.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Holzner, M; Morales, V L; Willmann, M; Dentz, M</p> <p>2015-07-01</p> <p>Intermittency of <span class="hlt">Lagrangian</span> velocity and acceleration is a key to understanding transport in complex systems ranging from fluid turbulence to flow in porous media. High-resolution optical particle tracking in a three-dimensional (3D) porous medium provides detailed 3D information on <span class="hlt">Lagrangian</span> velocities and accelerations. We find sharp transitions close to pore throats, and low flow variability in the pore bodies, which gives rise to stretched exponential <span class="hlt">Lagrangian</span> velocity and acceleration distributions characterized by a sharp peak at low velocity, superlinear evolution of particle dispersion, and double-peak behavior in the propagators. The velocity distribution is quantified in terms of pore geometry and flow connectivity, which forms the basis for a continuous-time random-walk model that sheds light on the observed <span class="hlt">Lagrangian</span> flow and transport behaviors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..MAR.V1290M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..MAR.V1290M"><span><span class="hlt">Lagrangian</span> Approach to Study Catalytic Fluidized Bed Reactors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Madi, Hossein; Hossein Madi Team; Marcelo Kaufman Rechulski Collaboration; Christian Ludwig Collaboration; Tilman Schildhauer Collaboration</p> <p>2013-03-01</p> <p><span class="hlt">Lagrangian</span> approach of fluidized bed reactors is a method, which simulates the movement of catalyst particles (caused by the fluidization) by changing the gas composition around them. Application of such an investigation is in the analysis of the state of catalysts and surface reactions under quasi-operando conditions. The hydrodynamics of catalyst particles within a fluidized bed reactor was studied to improve a <span class="hlt">Lagrangian</span> approach. A fluidized bed methanation employed in the production of Synthetic Natural Gas from wood was chosen as the case study. The <span class="hlt">Lagrangian</span> perspective was modified and improved to include different particle circulation patterns, which were investigated through this study. Experiments were designed to evaluate the concepts of the model. The results indicate that the setup is able to perform the designed experiments and a good agreement between the simulation and the experimental results were observed. It has been shown that fluidized bed reactors, as opposed to fixed beds, can be used to avoid the deactivation of the methanation catalyst due to carbon deposits. Carbon deposition on the catalysts tested with the <span class="hlt">Lagrangian</span> approach was investigated by temperature programmed oxidation (TPO) analysis of ex-situ catalyst samples. This investigation was done to identify the effects of particles velocity and their circulation patterns on the amount and type of deposited carbon on the catalyst surface. Ecole Polytechnique Federale de Lausanne(EPFL), Paul Scherrer Institute (PSI)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21517594','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21517594"><span><span class="hlt">Lagrangian</span> statistics and flow topology in forced two-dimensional turbulence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kadoch, B; Del-Castillo-Negrete, D; Bos, W J T; Schneider, K</p> <p>2011-03-01</p> <p>A study of the relationship between <span class="hlt">Lagrangian</span> statistics and flow topology in fluid turbulence is presented. The topology is characterized using the Weiss criterion, which provides a conceptually simple tool to partition the flow into topologically different regions: elliptic (vortex dominated), hyperbolic (deformation dominated), and intermediate (turbulent background). The flow corresponds to forced two-dimensional Navier-Stokes turbulence in doubly periodic and circular bounded domains, the latter with no-slip boundary conditions. In the double periodic domain, the probability density function (pdf) of the Weiss field exhibits a negative skewness consistent with the fact that in periodic domains the flow is dominated by coherent vortex structures. On the other hand, in the circular domain, the elliptic and hyperbolic regions seem to be statistically similar. We follow a <span class="hlt">Lagrangian</span> approach and obtain the statistics by tracking large ensembles of passively advected tracers. The pdfs of residence time in the topologically different regions are computed introducing the <span class="hlt">Lagrangian</span> Weiss field, i.e., the Weiss field computed along the particles' trajectories. In elliptic and hyperbolic regions, the pdfs of the residence time have self-similar algebraic decaying tails. In contrast, in the intermediate regions the pdf has exponential decaying tails. The conditional pdfs (with respect to the flow topology) of the <span class="hlt">Lagrangian</span> velocity exhibit Gaussian-like behavior in the periodic and in the bounded domains. In contrast to the freely decaying turbulence case, the conditional pdfs of the <span class="hlt">Lagrangian</span> acceleration in forced turbulence show a comparable level of intermittency in both the periodic and the bounded domains. The conditional pdfs of the <span class="hlt">Lagrangian</span> curvature are characterized, in all cases, by self-similar power-law behavior with a decay exponent of order -2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JGP....60..857V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JGP....60..857V"><span>The <span class="hlt">Lagrangian</span>-Hamiltonian formalism for higher order field theories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vitagliano, Luca</p> <p>2010-06-01</p> <p>We generalize the <span class="hlt">Lagrangian</span>-Hamiltonian formalism of Skinner and Rusk to higher order field theories on fiber bundles. As a byproduct we solve the long standing problem of defining, in a coordinate free manner, a Hamiltonian formalism for higher order <span class="hlt">Lagrangian</span> field theories. Namely, our formalism does only depend on the action functional and, therefore, unlike previously proposed ones, is free from any relevant ambiguity.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JPhA...44L5203P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JPhA...44L5203P"><span><span class="hlt">Lagrangian</span>-Hamiltonian unified formalism for autonomous higher order dynamical systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prieto-Martínez, Pedro Daniel; Román-Roy, Narciso</p> <p>2011-09-01</p> <p>The <span class="hlt">Lagrangian</span>-Hamiltonian unified formalism of Skinner and Rusk was originally stated for autonomous dynamical systems in classical mechanics. It has been generalized for non-autonomous first-order mechanical systems, as well as for first-order and higher order field theories. However, a complete generalization to higher order mechanical systems is yet to be described. In this work, after reviewing the natural geometrical setting and the <span class="hlt">Lagrangian</span> and Hamiltonian formalisms for higher order autonomous mechanical systems, we develop a complete generalization of the <span class="hlt">Lagrangian</span>-Hamiltonian unified formalism for these kinds of systems, and we use it to analyze some physical models from this new point of view.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1013698','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1013698"><span>Near-Surface Monsoonal Circulation of the Vietnam East Sea from <span class="hlt">Lagrangian</span> Drifters</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-09-30</p> <p>Sea from <span class="hlt">Lagrangian</span> Drifters Luca Centurioni Scripps Institution of Oceanography 9500 Gilman Drive Mail Code 0213 La Jolla, California 92103...Contribute to the study of coastal and open ocean current systems in sparsely sampled regions such us the South China Sea (SCS), using a <span class="hlt">Lagrangian</span> ...We intend to make new <span class="hlt">Lagrangian</span> and Eulerian observations to measure the seasonal circulation 1) in the coastal waters of Vietnam and 2) in the SCS</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18491565','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18491565"><span>[Soil functioning in foci of Siberian moth population outbreaks in the southern taiga <span class="hlt">subzone</span> of Central Siberia].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Krasnoshchekov, Iu N; Beskorovaĭnaia, I N</p> <p>2008-01-01</p> <p>The results of experimental studies on the contribution of zoogenic debris to transformation of soil properties in the southern taiga <span class="hlt">subzone</span> of Central Siberia are analyzed. They show that water-soluble carbon outflow from the forest litter increases by 21-26% upon a Siberian moth invasion, with this value decreasing to 14% one year later. The burning of forest in an area completely defoliated by the pest leads to changes in the stock, fractional composition, actual acidity, and ash element contents of the litter. The litter-dwelling invertebrate assemblage is almost completely destroyed by fire and begins to recover only after two years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DFDD17004D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DFDD17004D"><span><span class="hlt">Lagrangian</span> analysis of premixed turbulent combustion in hydrogen-air flames</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Darragh, Ryan; Poludnenko, Alexei; Hamlington, Peter</p> <p>2016-11-01</p> <p><span class="hlt">Lagrangian</span> analysis has long been a tool used to analyze non-reacting turbulent flows, and has recently gained attention in the reacting flow and combustion communities. The approach itself allows one to separate local molecular effects, such as those due to reactions or diffusion, from turbulent advective effects along fluid pathlines, or trajectories. Accurate calculation of these trajectories can, however, be rather difficult due to the chaotic nature of turbulent flows and the added complexity of reactions. In order to determine resolution requirements and verify the numerical algorithm, extensive tests are described in this talk for prescribed steady, unsteady, and chaotic flows, as well as for direct numerical simulations (DNS) of non-reacting homogeneous isotropic turbulence. The <span class="hlt">Lagrangian</span> analysis is then applied to DNS of premixed hydrogen-air flames at two different turbulence intensities for both single- and multi-step chemical mechanisms. Non-monotonic temperature and fuel-<span class="hlt">mass</span> fraction evolutions are found to exist along trajectories passing through the flame brush. Such non-monotonicity is shown to be due to molecular diffusion resulting from large spatial gradients created by turbulent advection. This work was supported by the Air Force Office of Scientific Research (AFOSR) under Award No. FA9550-14-1-0273, and the Department of Defense (DoD) High Performance Computing Modernization Program (HPCMP) under a Frontier project award.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28364756','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28364756"><span>Spatio-temporal organization of dynamics in a two-dimensional periodically driven vortex flow: A <span class="hlt">Lagrangian</span> flow network perspective.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lindner, Michael; Donner, Reik V</p> <p>2017-03-01</p> <p>We study the <span class="hlt">Lagrangian</span> dynamics of passive tracers in a simple model of a driven two-dimensional vortex resembling real-world geophysical flow patterns. Using a discrete approximation of the system's transfer operator, we construct a directed network that describes the exchange of <span class="hlt">mass</span> between distinct regions of the flow domain. By studying different measures characterizing flow network connectivity at different time-scales, we are able to identify the location of dynamically invariant structures and regions of maximum dispersion. Specifically, our approach allows us to delimit co-existing flow regimes with different dynamics. To validate our findings, we compare several network characteristics to the well-established finite-time Lyapunov exponents and apply a receiver operating characteristic analysis to identify network measures that are particularly useful for unveiling the skeleton of <span class="hlt">Lagrangian</span> chaos.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22489841-lagrangian-hamiltonian-constraints-guiding-center-hamiltonian-theories','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22489841-lagrangian-hamiltonian-constraints-guiding-center-hamiltonian-theories"><span><span class="hlt">Lagrangian</span> and Hamiltonian constraints for guiding-center Hamiltonian theories</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Tronko, Natalia; Brizard, Alain J.</p> <p></p> <p>A consistent guiding-center Hamiltonian theory is derived by Lie-transform perturbation method, with terms up to second order in magnetic-field nonuniformity. Consistency is demonstrated by showing that the guiding-center transformation presented here satisfies separate Jacobian and <span class="hlt">Lagrangian</span> constraints that have not been explored before. A new first-order term appearing in the guiding-center phase-space <span class="hlt">Lagrangian</span> is identified through a calculation of the guiding-center polarization. It is shown that this new polarization term also yields a simpler expression of the guiding-center toroidal canonical momentum, which satisfies an exact conservation law in axisymmetric magnetic geometries. Finally, an application of the guiding-center <span class="hlt">Lagrangian</span> constraint onmore » the guiding-center Hamiltonian yields a natural interpretation for its higher-order corrections.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26328583','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26328583"><span>Dissipative inertial transport patterns near coherent <span class="hlt">Lagrangian</span> eddies in the ocean.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Beron-Vera, Francisco J; Olascoaga, María J; Haller, George; Farazmand, Mohammad; Triñanes, Joaquín; Wang, Yan</p> <p>2015-08-01</p> <p>Recent developments in dynamical systems theory have revealed long-lived and coherent <span class="hlt">Lagrangian</span> (i.e., material) eddies in incompressible, satellite-derived surface ocean velocity fields. Paradoxically, observed drifting buoys and floating matter tend to create dissipative-looking patterns near oceanic eddies, which appear to be inconsistent with the conservative fluid particle patterns created by coherent <span class="hlt">Lagrangian</span> eddies. Here, we show that inclusion of inertial effects (i.e., those produced by the buoyancy and size finiteness of an object) in a rotating two-dimensional incompressible flow context resolves this paradox. Specifically, we obtain that anticyclonic coherent <span class="hlt">Lagrangian</span> eddies attract (repel) negatively (positively) buoyant finite-size particles, while cyclonic coherent <span class="hlt">Lagrangian</span> eddies attract (repel) positively (negatively) buoyant finite-size particles. We show how these results explain dissipative-looking satellite-tracked surface drifter and subsurface float trajectories, as well as satellite-derived Sargassum distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1919023P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1919023P"><span><span class="hlt">Lagrangian</span> Observations and Modeling of Marine Larvae</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paris, Claire B.; Irisson, Jean-Olivier</p> <p>2017-04-01</p> <p>Just within the past two decades, studies on the early-life history stages of marine organisms have led to new paradigms in population dynamics. Unlike passive plant seeds that are transported by the wind or by animals, marine larvae have motor and sensory capabilities. As a result, marine larvae have a tremendous capacity to actively influence their dispersal. This is continuously revealed as we develop new techniques to observe larvae in their natural environment and begin to understand their ability to detect cues throughout ontogeny, process the information, and use it to ride ocean currents and navigate their way back home, or to a place like home. We present innovative in situ and numerical modeling approaches developed to understand the underlying mechanisms of larval transport in the ocean. We describe a novel concept of a <span class="hlt">Lagrangian</span> platform, the Drifting In Situ Chamber (DISC), designed to observe and quantify complex larval behaviors and their interactions with the pelagic environment. We give a brief history of larval ecology research with the DISC, showing that swimming is directional in most species, guided by cues as diverse as the position of the sun or the underwater soundscape, and even that (unlike humans!) larvae orient better and swim faster when moving as a group. The observed <span class="hlt">Lagrangian</span> behavior of individual larvae are directly implemented in the Connectivity Modeling System (CMS), an open source <span class="hlt">Lagrangian</span> tracking application. Simulations help demonstrate the impact that larval behavior has compared to passive <span class="hlt">Lagrangian</span> trajectories. These methodologies are already the base of exciting findings and are promising tools for documenting and simulating the behavior of other small pelagic organisms, forecasting their migration in a changing ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1424084-toroidal-regularization-guiding-center-lagrangian','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1424084-toroidal-regularization-guiding-center-lagrangian"><span>Toroidal regularization of the guiding center <span class="hlt">Lagrangian</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Burby, J. W.; Ellison, C. L.</p> <p>2017-11-22</p> <p>In the <span class="hlt">Lagrangian</span> theory of guiding center motion, an effective magnetic field B* = B+ (m/e)v ∥∇ x b appears prominently in the equations of motion. Because the parallel component of this field can vanish, there is a range of parallel velocities where the <span class="hlt">Lagrangian</span> guiding center equations of motion are either ill-defined or very badly behaved. Moreover, the velocity dependence of B* greatly complicates the identification of canonical variables and therefore the formulation of symplectic integrators for guiding center dynamics. Here, this letter introduces a simple coordinate transformation that alleviates both these problems simultaneously. In the new coordinates, themore » Liouville volume element is equal to the toroidal contravariant component of the magnetic field. Consequently, the large-velocity singularity is completely eliminated. Moreover, passing from the new coordinate system to canonical coordinates is extremely simple, even if the magnetic field is devoid of flux surfaces. We demonstrate the utility of this approach in regularizing the guiding center <span class="hlt">Lagrangian</span> by presenting a new and stable one-step variational integrator for guiding centers moving in arbitrary time-dependent electromagnetic fields.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1424084-toroidal-regularization-guiding-center-lagrangian','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1424084-toroidal-regularization-guiding-center-lagrangian"><span>Toroidal regularization of the guiding center <span class="hlt">Lagrangian</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Burby, J. W.; Ellison, C. L.</p> <p></p> <p>In the <span class="hlt">Lagrangian</span> theory of guiding center motion, an effective magnetic field B* = B+ (m/e)v ∥∇ x b appears prominently in the equations of motion. Because the parallel component of this field can vanish, there is a range of parallel velocities where the <span class="hlt">Lagrangian</span> guiding center equations of motion are either ill-defined or very badly behaved. Moreover, the velocity dependence of B* greatly complicates the identification of canonical variables and therefore the formulation of symplectic integrators for guiding center dynamics. Here, this letter introduces a simple coordinate transformation that alleviates both these problems simultaneously. In the new coordinates, themore » Liouville volume element is equal to the toroidal contravariant component of the magnetic field. Consequently, the large-velocity singularity is completely eliminated. Moreover, passing from the new coordinate system to canonical coordinates is extremely simple, even if the magnetic field is devoid of flux surfaces. We demonstrate the utility of this approach in regularizing the guiding center <span class="hlt">Lagrangian</span> by presenting a new and stable one-step variational integrator for guiding centers moving in arbitrary time-dependent electromagnetic fields.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70033100','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70033100"><span>Eulerian-<span class="hlt">Lagrangian</span> numerical scheme for simulating advection, dispersion, and transient storage in streams and a comparison of numerical methods</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cox, T.J.; Runkel, R.L.</p> <p>2008-01-01</p> <p>Past applications of one-dimensional advection, dispersion, and transient storage zone models have almost exclusively relied on a central differencing, Eulerian numerical approximation to the nonconservative form of the fundamental equation. However, there are scenarios where this approach generates unacceptable error. A new numerical scheme for this type of modeling is presented here that is based on tracking <span class="hlt">Lagrangian</span> control volumes across a fixed (Eulerian) grid. Numerical tests are used to provide a direct comparison of the new scheme versus nonconservative Eulerian numerical methods, in terms of both accuracy and <span class="hlt">mass</span> conservation. Key characteristics of systems for which the <span class="hlt">Lagrangian</span> scheme performs better than the Eulerian scheme include: nonuniform flow fields, steep gradient plume fronts, and pulse and steady point source loadings in advection-dominated systems. A new analytical derivation is presented that provides insight into the loss of <span class="hlt">mass</span> conservation in the nonconservative Eulerian scheme. This derivation shows that loss of <span class="hlt">mass</span> conservation in the vicinity of spatial flow changes is directly proportional to the lateral inflow rate and the change in stream concentration due to the inflow. While the nonconservative Eulerian scheme has clearly worked well for past published applications, it is important for users to be aware of the scheme's limitations. ?? 2008 ASCE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27415358','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27415358"><span>Spectral-clustering approach to <span class="hlt">Lagrangian</span> vortex detection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hadjighasem, Alireza; Karrasch, Daniel; Teramoto, Hiroshi; Haller, George</p> <p>2016-06-01</p> <p>One of the ubiquitous features of real-life turbulent flows is the existence and persistence of coherent vortices. Here we show that such coherent vortices can be extracted as clusters of <span class="hlt">Lagrangian</span> trajectories. We carry out the clustering on a weighted graph, with the weights measuring pairwise distances of fluid trajectories in the extended phase space of positions and time. We then extract coherent vortices from the graph using tools from spectral graph theory. Our method locates all coherent vortices in the flow simultaneously, thereby showing high potential for automated vortex tracking. We illustrate the performance of this technique by identifying coherent <span class="hlt">Lagrangian</span> vortices in several two- and three-dimensional flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1817332C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1817332C"><span>Coupled Eulerian-<span class="hlt">Lagrangian</span> transport of large debris by tsunamis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Conde, Daniel A. S.; Ferreira, Rui M. L.; Sousa Oliveira, Carlos</p> <p>2016-04-01</p> <p>Tsunamis are notorious for the large disruption they can cause on coastal environments, not only due to the imparted momentum of the incoming wave but also due to its capacity to transport large quantities of solid debris, either from natural or human-made sources, over great distances. A 2DH numerical model under development at CERIS-IST (Ferreira et al., 2009; Conde, 2013) - STAV2D - capable of simulating solid transport in both Eulerian and <span class="hlt">Lagrangian</span> paradigms will be used to assess the relevance of <span class="hlt">Lagrangian</span>-Eulerian coupling when modelling the transport of solid debris by tsunamis. The model has been previously validated and applied to tsunami scenarios (Conde, 2013), being well-suited for overland tsunami propagation and capable of handling morphodynamic changes in estuaries and seashores. The discretization scheme is an explicit Finite Volume technique employing flux-vector splitting and a reviewed Roe-Riemann solver. Source term formulations are employed in a semi-implicit way, including the two-way coupling of the <span class="hlt">Lagrangian</span> and Eulerian solvers by means of conservative <span class="hlt">mass</span> and momentum transfers between fluid and solid phases. The model was applied to Sines Port, a major commercial port in Portugal, where two tsunamigenic scenarios are considered: an 8.5 Mw scenario, consistent with the Great Lisbon Earthquake and Tsunami of the 1st November 1755 (Baptista, 2009), and an hypothetical 9.5 Mw worst-case scenario based on the same historical event. Open-ocean propagation of these scenarios were simulated with GeoClaw model from ClawPack (Leveque, 2011). Following previous efforts on the modelling of debris transport by tsunamis in seaports (Conde, 2015), this work discusses the sensitivity of the obtained results with respect to the phenomenological detail of the employed Eulerian-<span class="hlt">Lagrangian</span> formulation and the resolution of the mesh used in the Eulerian solver. The results have shown that the fluid to debris <span class="hlt">mass</span> ratio is the key parameter regarding the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JHEP...10..106B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JHEP...10..106B"><span><span class="hlt">Lagrangians</span> for generalized Argyres-Douglas theories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benvenuti, Sergio; Giacomelli, Simone</p> <p>2017-10-01</p> <p>We continue the study of <span class="hlt">Lagrangian</span> descriptions of N=2 Argyres-Douglas theories. We use our recent interpretation in terms of sequential confinement to guess the <span class="hlt">Lagrangians</span> of all the Argyres-Douglas models with Abelian three dimensional mirror. We find classes of four dimensional N=1 quivers that flow in the infrared to generalized Argyres-Douglas theories, such as the ( A k , A kN + N -1) models. We study in detail how the N=1 chiral rings map to the Coulomb and Higgs Branches of the N=2 CFT's. The three dimensional mirror RG flows are shown to land on the N=4 complete graph quivers. We also compactify to three dimensions the gauge theory dual to ( A 1, D 4), and find the expected Abelianization duality with N=4 SQED with 3 flavors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040086560','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040086560"><span><span class="hlt">Lagrangian</span> Assimilation of Satellite Data for Climate Studies in the Arctic</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lindsay, Ronald W.; Zhang, Jin-Lun; Stern, Harry</p> <p>2004-01-01</p> <p>Under this grant we have developed and tested a new <span class="hlt">Lagrangian</span> model of sea ice. A <span class="hlt">Lagrangian</span> model keeps track of material parcels as they drift in the model domain. Besides providing a natural framework for the assimilation of <span class="hlt">Lagrangian</span> data, it has other advantages: 1) a model that follows material elements is well suited for a medium such as sea ice in which an element retains its identity for a long period of time; 2) model cells can be added or dropped as needed, allowing the spatial resolution to be increased in areas of high variability or dense observations; 3) ice from particular regions, such as the marginal seas, can be marked and traced for a long time; and 4) slip lines in the ice motion are accommodated more naturally because there is no internal grid. Our work makes use of these strengths of the <span class="hlt">Lagrangian</span> formulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=thought+AND+experiments&pg=2&id=EJ912884','ERIC'); return false;" href="https://eric.ed.gov/?q=thought+AND+experiments&pg=2&id=EJ912884"><span>Gravity, Time, and <span class="hlt">Lagrangians</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Huggins, Elisha</p> <p>2010-01-01</p> <p>Feynman mentioned to us that he understood a topic in physics if he could explain it to a college freshman, a high school student, or a dinner guest. Here we will discuss two topics that took us a while to get to that level. One is the relationship between gravity and time. The other is the minus sign that appears in the <span class="hlt">Lagrangian</span>. (Why would one…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NPGeo..24..379C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NPGeo..24..379C"><span>Insights into the three-dimensional <span class="hlt">Lagrangian</span> geometry of the Antarctic polar vortex</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Curbelo, Jezabel; José García-Garrido, Víctor; Mechoso, Carlos Roberto; Mancho, Ana Maria; Wiggins, Stephen; Niang, Coumba</p> <p>2017-07-01</p> <p>In this paper we study the three-dimensional (3-D) <span class="hlt">Lagrangian</span> structures in the stratospheric polar vortex (SPV) above Antarctica. We analyse and visualize these structures using <span class="hlt">Lagrangian</span> descriptor function M. The procedure for calculation with reanalysis data is explained. Benchmarks are computed and analysed that allow us to compare 2-D and 3-D aspects of <span class="hlt">Lagrangian</span> transport. Dynamical systems concepts appropriate to 3-D, such as normally hyperbolic invariant curves, are discussed and applied. In order to illustrate our approach we select an interval of time in which the SPV is relatively undisturbed (August 1979) and an interval of rapid SPV changes (October 1979). Our results provide new insights into the <span class="hlt">Lagrangian</span> structure of the vertical extension of the stratospheric polar vortex and its evolution. Our results also show complex <span class="hlt">Lagrangian</span> patterns indicative of strong mixing processes in the upper troposphere and lower stratosphere. Finally, during the transition to summer in the late spring, we illustrate the vertical structure of two counterrotating vortices, one the polar and the other an emerging one, and the invariant separatrix that divides them.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA590591','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA590591"><span>Hybrid Eulerian and <span class="hlt">Lagrangian</span> Simulation of Steep and Breaking Waves and Surface Fluxes in High Winds</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2012-09-30</p> <p><span class="hlt">Lagrangian</span> methods for free - surface turbulence and wave simulation . In the far field, coupled wind and wave simulations are used to obtain wind...to conserve the <span class="hlt">mass</span> precisely. When the wave breaks, the flow at the free surface may become very violent, air and water may be highly mixed...fluids free - surface flows that can be used to study the fundamental physics of wave breaking. The research will improve the understanding of air-sea</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22107674-stochastic-lagrangian-dynamics-charged-flows-regions-ionosphere','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22107674-stochastic-lagrangian-dynamics-charged-flows-regions-ionosphere"><span>Stochastic <span class="hlt">Lagrangian</span> dynamics for charged flows in the E-F regions of ionosphere</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Tang Wenbo; Mahalov, Alex</p> <p>2013-03-15</p> <p>We develop a three-dimensional numerical model for the E-F region ionosphere and study the <span class="hlt">Lagrangian</span> dynamics for plasma flows in this region. Our interest rests on the charge-neutral interactions and the statistics associated with stochastic <span class="hlt">Lagrangian</span> motion. In particular, we examine the organizing mixing patterns for plasma flows due to polarized gravity wave excitations in the neutral field, using <span class="hlt">Lagrangian</span> coherent structures (LCS). LCS objectively depict the flow topology-the extracted attractors indicate generation of ionospheric density gradients, due to accumulation of plasma. Using <span class="hlt">Lagrangian</span> measures such as the finite-time Lyapunov exponents, we locate the <span class="hlt">Lagrangian</span> skeletons for mixing in plasma,more » hence where charged fronts are expected to appear. With polarized neutral wind, we find that the corresponding plasma velocity is also polarized. Moreover, the polarized velocity alone, coupled with stochastic <span class="hlt">Lagrangian</span> motion, may give rise to polarized density fronts in plasma. Statistics of these trajectories indicate high level of non-Gaussianity. This includes clear signatures of variance, skewness, and kurtosis of displacements taking polarized structures aligned with the gravity waves, and being anisotropic.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/133663-human-sperm-chromosome-analysis-after-subzonal-sperm-insemination-hamster-oocytes','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/133663-human-sperm-chromosome-analysis-after-subzonal-sperm-insemination-hamster-oocytes"><span>Human sperm chromosome analysis after <span class="hlt">subzonal</span> sperm insemination of hamster oocytes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Cozzi, J.</p> <p>1994-09-01</p> <p>Sperm microinjection techniques, <span class="hlt">subzonal</span> sperm insemination (SUZI) and intracytoplasmic sperm injection (ICSI), have achieved a wide spread clinical application for the treatment of male infertility. To date, only one study has focused on sperm karyotypes after microinjection. Martin et al. reported a very high incidence of abnormal human sperm complements after ICSI into hamster oocytes. In the present study, are reported the first human sperm karyotypes after SUZI of hamster oocytes. Spermatozoa from two control donors were treated by calcium ionophore A23187 and injected under the zona of hamster eggs. The microinjected eggs were then cultured for cytogenetic analysis ofmore » the pronuclei. Out of 47 analyzed sperm chromosome metaphases, 5 (10.6%) were abnormal, 4 (8.5%) were hypohaploid and 1 (2.1%) had a structural abnormality. The sex ratio was not significantly different from the expected 1:1 ratio. Rates of chromosomal abnormalities in microinjected spermatozoa were similar to those observed in spermatozoa inseminated with zona free eggs, suggesting that SUZI procedure per se does not increase sperm chromosomal abnormalities.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/20774528-graviton-mass-cosmological-constant','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20774528-graviton-mass-cosmological-constant"><span>Graviton <span class="hlt">mass</span> or cosmological constant?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gabadadze, Gregory; Gruzinov, Andrei</p> <p>2005-12-15</p> <p>To describe a massive graviton in 4D Minkowski space-time one introduces a quadratic term in the <span class="hlt">Lagrangian</span>. This term, however, can lead to a readjustment or instability of the background instead of describing a massive graviton on flat space. We show that for all local 4D Lorentz-invariant <span class="hlt">mass</span> terms Minkowski space is unstable. The instability can develop in a time scale that is many orders of magnitude shorter than the inverse graviton <span class="hlt">mass</span>. We start with the Pauli-Fierz (PF) term that is the only local <span class="hlt">mass</span> term with no ghosts in the linearized approximation. We show that nonlinear completions ofmore » the PF <span class="hlt">Lagrangian</span> give rise to instability of Minkowski space. We continue with the <span class="hlt">mass</span> terms that are not of a PF type. Although these models are known to have ghosts in the linearized approximations, nonlinear interactions can lead to background change in which the ghosts are eliminated. In the latter case, however, the graviton perturbations on the new background are not massive. We argue that a consistent theory of a massive graviton on flat space can be formulated in theories with extra dimensions. They require an infinite number of fields or nonlocal description from a 4D point of view.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/1986/4145/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/1986/4145/report.pdf"><span>Users manual for a one-dimensional <span class="hlt">Lagrangian</span> transport model</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Schoellhamer, D.H.; Jobson, H.E.</p> <p>1986-01-01</p> <p>A Users Manual for the <span class="hlt">Lagrangian</span> Transport Model (LTM) is presented. The LTM uses <span class="hlt">Lagrangian</span> calculations that are based on a reference frame moving with the river flow. The <span class="hlt">Lagrangian</span> reference frame eliminates the need to numerically solve the convective term of the convection-diffusion equation and provides significant numerical advantages over the more commonly used Eulerian reference frame. When properly applied, the LTM can simulate riverine transport and decay processes within the accuracy required by most water quality studies. The LTM is applicable to steady or unsteady one-dimensional unidirectional flows in fixed channels with tributary and lateral inflows. Application of the LTM is relatively simple and optional capabilities improve the model 's convenience. Appendices give file formats and three example LTM applications that include the incorporation of the QUAL II water quality model 's reaction kinetics into the LTM. (Author 's abstract)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24176703','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24176703"><span>Evaluation of wastewater contaminant transport in surface waters using verified <span class="hlt">Lagrangian</span> sampling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Antweiler, Ronald C; Writer, Jeffrey H; Murphy, Sheila F</p> <p>2014-02-01</p> <p>Contaminants released from wastewater treatment plants can persist in surface waters for substantial distances. Much research has gone into evaluating the fate and transport of these contaminants, but this work has often assumed constant flow from wastewater treatment plants. However, effluent discharge commonly varies widely over a 24-hour period, and this variation controls contaminant loading and can profoundly influence interpretations of environmental data. We show that methodologies relying on the normalization of downstream data to conservative elements can give spurious results, and should not be used unless it can be verified that the same parcel of water was sampled. <span class="hlt">Lagrangian</span> sampling, which in theory samples the same water parcel as it moves downstream (the <span class="hlt">Lagrangian</span> parcel), links hydrologic and chemical transformation processes so that the in-stream fate of wastewater contaminants can be quantitatively evaluated. However, precise <span class="hlt">Lagrangian</span> sampling is difficult, and small deviations - such as missing the <span class="hlt">Lagrangian</span> parcel by less than 1h - can cause large differences in measured concentrations of all dissolved compounds at downstream sites, leading to erroneous conclusions regarding in-stream processes controlling the fate and transport of wastewater contaminants. Therefore, we have developed a method termed "verified <span class="hlt">Lagrangian</span>" sampling, which can be used to determine if the <span class="hlt">Lagrangian</span> parcel was actually sampled, and if it was not, a means for correcting the data to reflect the concentrations which would have been obtained had the <span class="hlt">Lagrangian</span> parcel been sampled. To apply the method, it is necessary to have concentration data for a number of conservative constituents from the upstream, effluent, and downstream sites, along with upstream and effluent concentrations that are constant over the short-term (typically 2-4h). These corrections can subsequently be applied to all data, including non-conservative constituents. Finally, we show how data</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28618545','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28618545"><span>Mean-<span class="hlt">Lagrangian</span> formalism and covariance of fluid turbulence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ariki, Taketo</p> <p>2017-05-01</p> <p>Mean-field-based <span class="hlt">Lagrangian</span> framework is developed for the fluid turbulence theory, which enables physically objective discussions, especially, of the history effect. Mean flow serves as a purely geometrical object of Lie group theory, providing useful operations to measure the objective rate and history integration of the general tensor field. The proposed framework is applied, on the one hand, to one-point closure model, yielding an objective expression of the turbulence viscoelastic effect. Application to two-point closure, on the other hand, is also discussed, where natural extension of known <span class="hlt">Lagrangian</span> correlation is discovered on the basis of an extended covariance group.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910035662&hterms=Lagrangian&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DLagrangian','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910035662&hterms=Lagrangian&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DLagrangian"><span><span class="hlt">Lagrangian</span> and Eulerian statistics obtained from direct numerical simulations of homogeneous turbulence</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Squires, Kyle D.; Eaton, John K.</p> <p>1991-01-01</p> <p>Direct numerical simulation is used to study dispersion in decaying isotropic turbulence and homogeneous shear flow. Both <span class="hlt">Lagrangian</span> and Eulerian data are presented allowing direct comparison, but at fairly low Reynolds number. The quantities presented include properties of the dispersion tensor, isoprobability contours of particle displacement, <span class="hlt">Lagrangian</span> and Eulerian velocity autocorrelations and time scale ratios, and the eddy diffusivity tensor. The <span class="hlt">Lagrangian</span> time microscale is found to be consistently larger than the Eulerian microscale, presumably due to the advection of the small scales by the large scales in the Eulerian reference frame.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24235888','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24235888"><span>Incomplete augmented <span class="hlt">Lagrangian</span> preconditioner for steady incompressible Navier-Stokes equations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tan, Ning-Bo; Huang, Ting-Zhu; Hu, Ze-Jun</p> <p>2013-01-01</p> <p>An incomplete augmented <span class="hlt">Lagrangian</span> preconditioner, for the steady incompressible Navier-Stokes equations discretized by stable finite elements, is proposed. The eigenvalues of the preconditioned matrix are analyzed. Numerical experiments show that the incomplete augmented <span class="hlt">Lagrangian</span>-based preconditioner proposed is very robust and performs quite well by the Picard linearization or the Newton linearization over a wide range of values of the viscosity on both uniform and stretched grids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3819930','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3819930"><span>Incomplete Augmented <span class="hlt">Lagrangian</span> Preconditioner for Steady Incompressible Navier-Stokes Equations</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tan, Ning-Bo; Huang, Ting-Zhu; Hu, Ze-Jun</p> <p>2013-01-01</p> <p>An incomplete augmented <span class="hlt">Lagrangian</span> preconditioner, for the steady incompressible Navier-Stokes equations discretized by stable finite elements, is proposed. The eigenvalues of the preconditioned matrix are analyzed. Numerical experiments show that the incomplete augmented <span class="hlt">Lagrangian</span>-based preconditioner proposed is very robust and performs quite well by the Picard linearization or the Newton linearization over a wide range of values of the viscosity on both uniform and stretched grids. PMID:24235888</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/1986/4144/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/1986/4144/report.pdf"><span>Programmers manual for a one-dimensional <span class="hlt">Lagrangian</span> transport model</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Schoellhamer, D.H.; Jobson, H.E.</p> <p>1986-01-01</p> <p>A one-dimensional <span class="hlt">Lagrangian</span> transport model for simulating water-quality constituents such as temperature, dissolved oxygen , and suspended sediment in rivers is presented in this Programmers Manual. <span class="hlt">Lagrangian</span> transport modeling techniques, the model 's subroutines, and the user-written decay-coefficient subroutine are discussed in detail. Appendices list the program codes. The Programmers Manual is intended for the model user who needs to modify code either to adapt the model to a particular need or to use reaction kinetics not provided with the model. (Author 's abstract)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1980IJTP...19..405C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1980IJTP...19..405C"><span>Lorentz Invariance of Gravitational <span class="hlt">Lagrangians</span> in the Space of Reference Frames</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cognola, G.</p> <p>1980-06-01</p> <p>The recently proposed theories of gravitation in the space of reference frames S are based on a <span class="hlt">Lagrangian</span> invariant with respect to the homogeneous Lorentz group. However, in theories of this kind, the Lorentz invariance is not a necessary consequence of some physical principles, as in the theories formulated in space-time, but rather a purely esthetic request. In the present paper, we give a systematic method for the construction of gravitational theories in the space S, without assuming a priori the Lorentz invariance of the <span class="hlt">Lagrangian</span>. The Einstein-Cartan equations of gravitation are obtained requiring only that the <span class="hlt">Lagrangian</span> is invariant under proper rotations and has particular transformation properties under space reflections and space-time dilatations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26778728','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26778728"><span>Deconstructing field-induced ketene isomerization through <span class="hlt">Lagrangian</span> descriptors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Craven, Galen T; Hernandez, Rigoberto</p> <p>2016-02-07</p> <p>The time-dependent geometrical separatrices governing state transitions in field-induced ketene isomerization are constructed using the method of <span class="hlt">Lagrangian</span> descriptors. We obtain the stable and unstable manifolds of time-varying transition states as dynamic phase space objects governing configurational changes when the ketene molecule is subjected to an oscillating electric field. The dynamics of the isomerization reaction are modeled through classical trajectory studies on the Gezelter-Miller potential energy surface and an approximate dipole moment model which is coupled to a time-dependent electric field. We obtain a representation of the reaction geometry, over varying field strengths and oscillation frequencies, by partitioning an initial phase space into basins labeled according to which product state is reached at a given time. The borders between these basins are in agreement with those obtained using <span class="hlt">Lagrangian</span> descriptors, even in regimes exhibiting chaotic dynamics. Major outcomes of this work are: validation and extension of a transition state theory framework built from <span class="hlt">Lagrangian</span> descriptors, elaboration of the applicability for this theory to periodically- and aperiodically-driven molecular systems, and prediction of regimes in which isomerization of ketene and its derivatives may be controlled using an external field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014DSRI...90...27P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014DSRI...90...27P"><span>Identifying <span class="hlt">Lagrangian</span> fronts with favourable fishery conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prants, S. V.; Budyansky, M. V.; Uleysky, M. Yu.</p> <p>2014-08-01</p> <p><span class="hlt">Lagrangian</span> fronts (LFs) in the ocean are defined as boundaries between surface waters with strongly different <span class="hlt">Lagrangian</span> properties. They can be accurately detected in a given velocity field by computing synoptic maps for displacements of synthetic tracers and other <span class="hlt">Lagrangian</span> indicators. We use Pacific saury catch and location data for a number of commercial fishery seasons in the region of the northwest Pacific with one of the richest fishery in the world. It is shown statistically that the saury fishing grounds with maximal catches are not randomly distributed over the region but located mainly along the sharp LFs where productive cold waters of the Oyashio Current, warmer waters of the southern branch of the Soya Current, and waters of warm-core Kuroshio rings converge. Computation of those fronts in altimetric geostrophic velocity fields both in the years with the First and Second Oyashio Intrusions shows that in spite of different oceanographic conditions LF locations may serve as good indicators of potential fishing grounds. Possible biophysical reasons for saury aggregation near sharp LFs are discussed. We propose a mechanism for effective export of nutrient rich waters based on stretching of material lines in the vicinity of hyperbolic objects in the ocean. The developed method, based on identifying LFs in any velocity fields, is quite general and may be applied to find potential fishing grounds for the other pelagic fish.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000MPLA...15...55H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000MPLA...15...55H"><span>Symmetries of SU(2) Skyrmion in Hamiltonian and <span class="hlt">Lagrangian</span> Approaches</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hong, Soon-Tae; Kim, Yong-Wan; Park, Young-Jai</p> <p></p> <p>We apply the Batalin-Fradkin-Tyutin (BFT) method to the SU(2) Skyrmion to study the full symmetry structure of the model at the first-class Hamiltonian level. On the other hand, we also analyze the symmetry structure of the action having the WZ term, which corresponds to this Hamiltonian, in the framework of the <span class="hlt">Lagrangian</span> approach. Furthermore, following the BFV formalism we derive the BRST invariant gauge fixed <span class="hlt">Lagrangian</span> from the above extended action.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017CPM.....4..321N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017CPM.....4..321N"><span>Seakeeping with the semi-<span class="hlt">Lagrangian</span> particle finite element method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nadukandi, Prashanth; Servan-Camas, Borja; Becker, Pablo Agustín; Garcia-Espinosa, Julio</p> <p>2017-07-01</p> <p>The application of the semi-<span class="hlt">Lagrangian</span> particle finite element method (SL-PFEM) for the seakeeping simulation of the wave adaptive modular vehicle under spray generating conditions is presented. The time integration of the <span class="hlt">Lagrangian</span> advection is done using the explicit integration of the velocity and acceleration along the streamlines (X-IVAS). Despite the suitability of the SL-PFEM for the considered seakeeping application, small time steps were needed in the X-IVAS scheme to control the solution accuracy. A preliminary proposal to overcome this limitation of the X-IVAS scheme for seakeeping simulations is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28041621','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28041621"><span>A new method to calibrate <span class="hlt">Lagrangian</span> model with ASAR images for oil slick trajectory.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tian, Siyu; Huang, Xiaoxia; Li, Hongga</p> <p>2017-03-15</p> <p>Since <span class="hlt">Lagrangian</span> model coefficients vary with different conditions, it is necessary to calibrate the model to obtain optimal coefficient combination for special oil spill accident. This paper focuses on proposing a new method to calibrate <span class="hlt">Lagrangian</span> model with time series of Envisat ASAR images. Oil slicks extracted from time series images form a detected trajectory of special oil slick. <span class="hlt">Lagrangian</span> model is calibrated by minimizing the difference between simulated trajectory and detected trajectory. mean center position distance difference (MCPD) and rotation difference (RD) of Oil slicks' or particles' standard deviational ellipses (SDEs) are calculated as two evaluations. The two parameters are taken to evaluate the performance of <span class="hlt">Lagrangian</span> transport model with different coefficient combinations. This method is applied to Penglai 19-3 oil spill accident. The simulation result with calibrated model agrees well with related satellite observations. It is suggested the new method is effective to calibrate <span class="hlt">Lagrangian</span> model. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29316401','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29316401"><span>Extended <span class="hlt">Lagrangian</span> Excited State Molecular Dynamics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bjorgaard, J A; Sheppard, D; Tretiak, S; Niklasson, A M N</p> <p>2018-02-13</p> <p>An extended <span class="hlt">Lagrangian</span> framework for excited state molecular dynamics (XL-ESMD) using time-dependent self-consistent field theory is proposed. The formulation is a generalization of the extended <span class="hlt">Lagrangian</span> formulations for ground state Born-Oppenheimer molecular dynamics [Phys. Rev. Lett. 2008 100, 123004]. The theory is implemented, demonstrated, and evaluated using a time-dependent semiempirical model, though it should be generally applicable to ab initio theory. The simulations show enhanced energy stability and a significantly reduced computational cost associated with the iterative solutions of both the ground state and the electronically excited states. Relaxed convergence criteria can therefore be used both for the self-consistent ground state optimization and for the iterative subspace diagonalization of the random phase approximation matrix used to calculate the excited state transitions. The XL-ESMD approach is expected to enable numerically efficient excited state molecular dynamics for such methods as time-dependent Hartree-Fock (TD-HF), Configuration Interactions Singles (CIS), and time-dependent density functional theory (TD-DFT).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21279359','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21279359"><span>Differential geometry based solvation model II: <span class="hlt">Lagrangian</span> formulation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Zhan; Baker, Nathan A; Wei, G W</p> <p>2011-12-01</p> <p>Solvation is an elementary process in nature and is of paramount importance to more sophisticated chemical, biological and biomolecular processes. The understanding of solvation is an essential prerequisite for the quantitative description and analysis of biomolecular systems. This work presents a <span class="hlt">Lagrangian</span> formulation of our differential geometry based solvation models. The <span class="hlt">Lagrangian</span> representation of biomolecular surfaces has a few utilities/advantages. First, it provides an essential basis for biomolecular visualization, surface electrostatic potential map and visual perception of biomolecules. Additionally, it is consistent with the conventional setting of implicit solvent theories and thus, many existing theoretical algorithms and computational software packages can be directly employed. Finally, the <span class="hlt">Lagrangian</span> representation does not need to resort to artificially enlarged van der Waals radii as often required by the Eulerian representation in solvation analysis. The main goal of the present work is to analyze the connection, similarity and difference between the Eulerian and <span class="hlt">Lagrangian</span> formalisms of the solvation model. Such analysis is important to the understanding of the differential geometry based solvation model. The present model extends the scaled particle theory of nonpolar solvation model with a solvent-solute interaction potential. The nonpolar solvation model is completed with a Poisson-Boltzmann (PB) theory based polar solvation model. The differential geometry theory of surfaces is employed to provide a natural description of solvent-solute interfaces. The optimization of the total free energy functional, which encompasses the polar and nonpolar contributions, leads to coupled potential driven geometric flow and PB equations. Due to the development of singularities and nonsmooth manifolds in the <span class="hlt">Lagrangian</span> representation, the resulting potential-driven geometric flow equation is embedded into the Eulerian representation for the purpose of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3113640','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3113640"><span>Differential geometry based solvation model II: <span class="hlt">Lagrangian</span> formulation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chen, Zhan; Baker, Nathan A.; Wei, G. W.</p> <p>2010-01-01</p> <p>Solvation is an elementary process in nature and is of paramount importance to more sophisticated chemical, biological and biomolecular processes. The understanding of solvation is an essential prerequisite for the quantitative description and analysis of biomolecular systems. This work presents a <span class="hlt">Lagrangian</span> formulation of our differential geometry based solvation model. The <span class="hlt">Lagrangian</span> representation of biomolecular surfaces has a few utilities/advantages. First, it provides an essential basis for biomolecular visualization, surface electrostatic potential map and visual perception of biomolecules. Additionally, it is consistent with the conventional setting of implicit solvent theories and thus, many existing theoretical algorithms and computational software packages can be directly employed. Finally, the <span class="hlt">Lagrangian</span> representation does not need to resort to artificially enlarged van der Waals radii as often required by the Eulerian representation in solvation analysis. The main goal of the present work is to analyze the connection, similarity and difference between the Eulerian and <span class="hlt">Lagrangian</span> formalisms of the solvation model. Such analysis is important to the understanding of the differential geometry based solvation model. The present model extends the scaled particle theory (SPT) of nonpolar solvation model with a solvent-solute interaction potential. The nonpolar solvation model is completed with a Poisson-Boltzmann (PB) theory based polar solvation model. The differential geometry theory of surfaces is employed to provide a natural description of solvent-solute interfaces. The minimization of the total free energy functional, which encompasses the polar and nonpolar contributions, leads to coupled potential driven geometric flow and Poisson-Boltzmann equations. Due to the development of singularities and nonsmooth manifolds in the <span class="hlt">Lagrangian</span> representation, the resulting potential-driven geometric flow equation is embedded into the Eulerian representation for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AMT.....8...69R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AMT.....8...69R"><span>An airborne perfluorocarbon tracer system and its first application for a <span class="hlt">Lagrangian</span> experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ren, Y.; Baumann, R.; Schlager, H.</p> <p>2015-01-01</p> <p>A perfluorocarbon tracer system (PERTRAS), specifically designed for <span class="hlt">Lagrangian</span> aircraft experiments, has been developed by the Deutsches Zentrum für Luft- und Raumfahrt (German Aerospace Center, DLR). It consists of three main parts: a tracer release unit (RU), an adsorption tube sampler (ATS), and a tracer analytical system. The RU was designed for airborne tracer release experiments; meanwhile, it can be used on various platforms for different experimental purposes (here research vessel). PERTRAS was for the first time applied in the field campaign Stratospheric ozone: Halogen Impacts in a Varying Atmosphere (SHIVA) in November 2011. An amount of 8.8 kg perfluoromethylcyclopentane (PMCP) was released aboard the research vessel Sonne (RV Sonne) near the operational site of this campaign, Miri, Malaysia, on 21 November. The tracer samples collected using the ATS onboard the DLR research aircraft Falcon were analyzed in the laboratory using a thermal desorber-gas chromatography-<span class="hlt">mass</span> spectrometry (TD-GC-MS) system. Guided by forecasts calculated with the <span class="hlt">Lagrangian</span> model Hybrid Single Particle <span class="hlt">Lagrangian</span> Integrated Trajectory (HYSPLIT), 64 tracer samples were collected onboard the Falcon approximately 5 and 25 h after the release, mostly with a time resolution of 1 min. Enhanced PMCP concentrations relative to ambient PMCP background values (mean: 6.62 fmol mol-1) were detected during three intersects of the fresh tracer plume (age 5 h), with a maximum value of 301.33 fmol mol-1. This indicates that the fresh tracer plume was successfully intercepted at the forecast position. During the second flight, 25 h after the release, the center of tracer plume was not detected by the sampling system due to a faster advection of the plume than forecast. The newly developed PERTRAS system has been successfully deployed for the first time. The instrumental setup and comparisons between the measurements and HYSPLIT simulations are presented in this study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AMTD....7.6791R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AMTD....7.6791R"><span>An airborne perfluorocarbon tracer system and its first application for a <span class="hlt">Lagrangian</span> experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ren, Y.; Baumann, R.; Schlager, H.</p> <p>2014-07-01</p> <p>A perfluorocarbon tracer system (PERTRAS), specifically designed for <span class="hlt">Lagrangian</span> aircraft experiments, has been developed by the Deutsches Zentrum für Luft- und Raumfahrt (German Aerospace Center, DLR). It consists of three main parts: a tracer release unit (RU), an adsorption tube sampler (ATS) and a tracer analytical system. The RU was designed for airborne tracer release experiments; meanwhile, it can be used on various platforms for different experimental purpose (here research vessel). PERTRAS was for the first time applied in the field campaign Stratospheric ozone: halogen Impacts in a Varying Atmosphere (SHIVA) in November 2011. An amount of 8.8 kg perfluoromethylcyclopentane (PMCP) was released aboard the research vessel Sonne (RV Sonne) near the operational site of this campaign, Miri, Malaysia, on 21 November. The tracer samples collected using the ATS on board the DLR research aircraft Falcon were analyzed in the laboratory using a thermal desorber/gas chromatography/<span class="hlt">mass</span> spectrometry (TD/GC/MS) system. Guided by forecasts calculated with the <span class="hlt">Lagrangian</span> model, Hybrid Single Particle <span class="hlt">Lagrangian</span> Integrated Trajectory (HYSPLIT), 64 tracer samples were collected onboard the Falcon approximately 5 and 25 h after the release, respectively, mostly with a time resolution of 1 min. Enhanced PMCP concentrations relative to ambient PMCP background values (mean: 6.62 fmol mol-1) were detected during three intersects of the fresh tracer plume (age 5 h), with a maximum value of 301.33 fmol mol-1. This indicates that the fresh tracer plume was successfully intercepted at the forecasted position. During the second flight, 25 h after the release, the center of tracer plume was not detected by the sampling system due to a faster advection of the plume than forecasted. The newly developed PERTRAS system has been successfully deployed for the first time. The instrumental set-up and comparisons between the measurements and HYSPLIT simulations are presented in this study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvD..97h4048D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvD..97h4048D"><span><span class="hlt">Lagrangian</span> formulation of the general relativistic Poynting-Robertson effect</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>De Falco, Vittorio; Battista, Emmanuele; Falanga, Maurizio</p> <p>2018-04-01</p> <p>We propose the <span class="hlt">Lagrangian</span> formulation for describing the motion of a test particle in a general relativistic, stationary, and axially symmetric spacetime. The test particle is also affected by a radiation field, modeled as a coherent flux of photons traveling along the null geodesics of the background spacetime, including the general relativistic Poynting-Robertson effect. The innovative part of this work is to prove the existence of the potential linked to the dissipative action caused by the Poynting-Robertson effect in general relativity through the help of an integrating factor, depending on the energy of the system. Generally, such kinds of inverse problems involving dissipative effects might not admit a <span class="hlt">Lagrangian</span> formulation; especially, in general relativity, there are no examples of such attempts in the literature so far. We reduce this general relativistic <span class="hlt">Lagrangian</span> formulation to the classic case in the weak-field limit. This approach facilitates further studies in improving the treatment of the radiation field, and it contains, for example, some implications for a deeper comprehension of the gravitational waves.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DFDD33003C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DFDD33003C"><span><span class="hlt">Lagrangian</span> transport in a class of three-dimensional buoyancy-driven flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Contreras, Sebastian; Speetjens, Michel; Clercx, Herman</p> <p>2017-11-01</p> <p>The study concerns the <span class="hlt">Lagrangian</span> dynamics of three-dimensional (3D) buoyancy-driven cavity flows under steady and laminar conditions due to a global temperature gradient imposed via an opposite hot and cold sidewall. This serves as archetypal configuration for natural-convection flows in which gravity is perpendicular to the global temperature gradient. Limited insight into the <span class="hlt">Lagrangian</span> properties of this class of flows motivates this study. The 3D <span class="hlt">Lagrangian</span> dynamics are investigated in terms of the generic structure of the <span class="hlt">Lagrangian</span> flow topology that is described in terms of the Grashof number (Gr) and the Prandtl number (Pr). Gr is the principal control parameter for the flow topology: vanishing Gr yields a state of closed streamlines (integrable state); increasing Gr causes the formation of toroidal coherent structures embedded in chaotic streamlines governed by Hamiltonian mechanisms. Fluid inertia prevails for ``smaller'' Gr. A buoyancy-induced bifurcation of the flow topology occurs for ``larger'' Gr and underlies the emergence of ``secondary rolls'' and secondary tori for ``larger'' Pr. Stagnation points and corresponding manifold interactions are key to the dynamics. S.C. acknowledges financial support from Consejo Nacional de Ciencia y Tecnología (CONACYT).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011IJEaS.100.1237Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011IJEaS.100.1237Y"><span>Structural analysis of the Gachsar <span class="hlt">sub-zone</span> in central Alborz range; constrain for inversion tectonics followed by the range transverse faulting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yassaghi, A.; Naeimi, A.</p> <p>2011-08-01</p> <p>Analysis of the Gachsar structural <span class="hlt">sub-zone</span> has been carried out to constrain structural evolution of the central Alborz range situated in the central Alpine Himalayan orogenic system. The <span class="hlt">sub-zone</span> bounded by the northward-dipping Kandovan Fault to the north and the southward-dipping Taleghan Fault to the south is transversely cut by several sinistral faults. The Kandovan Fault that controls development of the Eocene rocks in its footwall from the Paleozoic-Mesozoic units in the fault hanging wall is interpreted as an inverted basin-bounding fault. Structural evidences include the presence of a thin-skinned imbricate thrust system propagated from a detachment zone that acts as a footwall shortcut thrust, development of large synclines in the fault footwall as well as back thrusts and pop-up structures on the fault hanging wall. Kinematics of the inverted Kandovan Fault and its accompanying structures constrain the N-S shortening direction proposed for the Alborz range until Late Miocene. The transverse sinistral faults that are in acute angle of 15° to a major magnetic lineament, which represents a basement fault, are interpreted to develop as synthetic Riedel shears on the cover sequences during reactivation of the basement fault. This overprinting of the transverse faults on the earlier inverted extensional fault occurs since the Late Miocene when the south Caspian basin block attained a SSW movement relative to the central Iran. Therefore, recent deformation in the range is a result of the basement transverse-fault reactivation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010CompM..46..883R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010CompM..46..883R"><span>A monolithic <span class="hlt">Lagrangian</span> approach for fluid-structure interaction problems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ryzhakov, P. B.; Rossi, R.; Idelsohn, S. R.; Oñate, E.</p> <p>2010-11-01</p> <p>Current work presents a monolithic method for the solution of fluid-structure interaction problems involving flexible structures and free-surface flows. The technique presented is based upon the utilization of a <span class="hlt">Lagrangian</span> description for both the fluid and the structure. A linear displacement-pressure interpolation pair is used for the fluid whereas the structure utilizes a standard displacement-based formulation. A slight fluid compressibility is assumed that allows to relate the mechanical pressure to the local volume variation. The method described features a global pressure condensation which in turn enables the definition of a purely displacement-based linear system of equations. A matrix-free technique is used for the solution of such linear system, leading to an efficient implementation. The result is a robust method which allows dealing with FSI problems involving arbitrary variations in the shape of the fluid domain. The method is completely free of spurious added-<span class="hlt">mass</span> effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015WRR....51.1916W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015WRR....51.1916W"><span>Variational <span class="hlt">Lagrangian</span> data assimilation in open channel networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Qingfang; Tinka, Andrew; Weekly, Kevin; Beard, Jonathan; Bayen, Alexandre M.</p> <p>2015-04-01</p> <p>This article presents a data assimilation method in a tidal system, where data from both <span class="hlt">Lagrangian</span> drifters and Eulerian flow sensors were fused to estimate water velocity. The system is modeled by first-order, hyperbolic partial differential equations subject to periodic forcing. The estimation problem can then be formulated as the minimization of the difference between the observed variables and model outputs, and eventually provide the velocity and water stage of the hydrodynamic system. The governing equations are linearized and discretized using an implicit discretization scheme, resulting in linear equality constraints in the optimization program. Thus, the flow estimation can be formed as an optimization problem and efficiently solved. The effectiveness of the proposed method was substantiated by a large-scale field experiment in the Sacramento-San Joaquin River Delta in California. A fleet of 100 sensors developed at the University of California, Berkeley, were deployed in Walnut Grove, CA, to collect a set of <span class="hlt">Lagrangian</span> data, a time series of positions as the sensors moved through the water. Measurements were also taken from Eulerian sensors in the region, provided by the United States Geological Survey. It is shown that the proposed method can effectively integrate <span class="hlt">Lagrangian</span> and Eulerian measurement data, resulting in a suited estimation of the flow variables within the hydraulic system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRC..119.8029L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRC..119.8029L"><span><span class="hlt">Lagrangian</span> predictability characteristics of an Ocean Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lacorata, Guglielmo; Palatella, Luigi; Santoleri, Rosalia</p> <p>2014-11-01</p> <p>The Mediterranean Forecasting System (MFS) Ocean Model, provided by INGV, has been chosen as case study to analyze <span class="hlt">Lagrangian</span> trajectory predictability by means of a dynamical systems approach. To this regard, numerical trajectories are tested against a large amount of Mediterranean drifter data, used as sample of the actual tracer dynamics across the sea. The separation rate of a trajectory pair is measured by computing the Finite-Scale Lyapunov Exponent (FSLE) of first and second kind. An additional kinematic <span class="hlt">Lagrangian</span> model (KLM), suitably treated to avoid "sweeping"-related problems, has been nested into the MFS in order to recover, in a statistical sense, the velocity field contributions to pair particle dispersion, at mesoscale level, smoothed out by finite resolution effects. Some of the results emerging from this work are: (a) drifter pair dispersion displays Richardson's turbulent diffusion inside the [10-100] km range, while numerical simulations of MFS alone (i.e., without subgrid model) indicate exponential separation; (b) adding the subgrid model, model pair dispersion gets very close to observed data, indicating that KLM is effective in filling the energy "mesoscale gap" present in MFS velocity fields; (c) there exists a threshold size beyond which pair dispersion becomes weakly sensitive to the difference between model and "real" dynamics; (d) the whole methodology here presented can be used to quantify model errors and validate numerical current fields, as far as forecasts of <span class="hlt">Lagrangian</span> dispersion are concerned.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018IJMPD..2730002C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018IJMPD..2730002C"><span>Nonpolynomial <span class="hlt">Lagrangian</span> approach to regular black holes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Colléaux, Aimeric; Chinaglia, Stefano; Zerbini, Sergio</p> <p></p> <p>We present a review on <span class="hlt">Lagrangian</span> models admitting spherically symmetric regular black holes (RBHs), and cosmological bounce solutions. Nonlinear electrodynamics, nonpolynomial gravity, and fluid approaches are explained in details. They consist respectively in a gauge invariant generalization of the Maxwell-<span class="hlt">Lagrangian</span>, in modifications of the Einstein-Hilbert action via nonpolynomial curvature invariants, and finally in the reconstruction of density profiles able to cure the central singularity of black holes. The nonpolynomial gravity curvature invariants have the special property to be second-order and polynomial in the metric field, in spherically symmetric spacetimes. Along the way, other models and results are discussed, and some general properties that RBHs should satisfy are mentioned. A covariant Sakharov criterion for the absence of singularities in dynamical spherically symmetric spacetimes is also proposed and checked for some examples of such regular metric fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900036170&hterms=ito&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dito','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900036170&hterms=ito&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dito"><span>The augmented <span class="hlt">Lagrangian</span> method for parameter estimation in elliptic systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ito, Kazufumi; Kunisch, Karl</p> <p>1990-01-01</p> <p>In this paper a new technique for the estimation of parameters in elliptic partial differential equations is developed. It is a hybrid method combining the output-least-squares and the equation error method. The new method is realized by an augmented <span class="hlt">Lagrangian</span> formulation, and convergence as well as rate of convergence proofs are provided. Technically the critical step is the verification of a coercivity estimate of an appropriately defined <span class="hlt">Lagrangian</span> functional. To obtain this coercivity estimate a seminorm regularization technique is used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JCoPh.225..464J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JCoPh.225..464J"><span>A purely <span class="hlt">Lagrangian</span> method for computing linearly-perturbed flows in spherical geometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jaouen, Stéphane</p> <p>2007-07-01</p> <p>In many physical applications, one wishes to control the development of multi-dimensional instabilities around a one-dimensional (1D) complex flow. For predicting the growth rates of these perturbations, a general numerical approach is viable which consists in solving simultaneously the one-dimensional equations and their linearized form for three-dimensional perturbations. In Clarisse et al. [J.-M. Clarisse, S. Jaouen, P.-A. Raviart, A Godunov-type method in <span class="hlt">Lagrangian</span> coordinates for computing linearly-perturbed planar-symmetric flows of gas dynamics, J. Comp. Phys. 198 (2004) 80-105], a class of Godunov-type schemes for planar-symmetric flows of gas dynamics has been proposed. Pursuing this effort, we extend these results to spherically symmetric flows. A new method to derive the <span class="hlt">Lagrangian</span> perturbation equations, based on the canonical form of systems of conservation laws with zero entropy flux [B. Després, <span class="hlt">Lagrangian</span> systems of conservation laws. Invariance properties of <span class="hlt">Lagrangian</span> systems of conservation laws, approximate Riemann solvers and the entropy condition, Numer. Math. 89 (2001) 99-134; B. Després, C. Mazeran, <span class="hlt">Lagrangian</span> gas dynamics in two dimensions and <span class="hlt">Lagrangian</span> systems, Arch. Rational Mech. Anal. 178 (2005) 327-372] is also described. It leads to many advantages. First of all, many physical problems we are interested in enter this formalism (gas dynamics, two-temperature plasma equations, ideal magnetohydrodynamics, etc.) whatever is the geometry. Secondly, a class of numerical entropic schemes is available for the basic flow [11]. Last, linearizing and devising numerical schemes for the perturbed flow is straightforward. The numerical capabilities of these methods are illustrated on three test cases of increasing difficulties and we show that - due to its simplicity and its low computational cost - the Linear Perturbations Code (LPC) is a powerful tool to understand and predict the development of hydrodynamic instabilities in the linear regime.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70189679','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70189679"><span>Evaluation of wastewater contaminant transport in surface waters using verified <span class="hlt">Lagrangian</span> sampling</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Antweiler, Ronald C.; Writer, Jeffrey H.; Murphy, Sheila F.</p> <p>2014-01-01</p> <p>Contaminants released from wastewater treatment plants can persist in surface waters for substantial distances. Much research has gone into evaluating the fate and transport of these contaminants, but this work has often assumed constant flow from wastewater treatment plants. However, effluent discharge commonly varies widely over a 24-hour period, and this variation controls contaminant loading and can profoundly influence interpretations of environmental data. We show that methodologies relying on the normalization of downstream data to conservative elements can give spurious results, and should not be used unless it can be verified that the same parcel of water was sampled. <span class="hlt">Lagrangian</span> sampling, which in theory samples the same water parcel as it moves downstream (the <span class="hlt">Lagrangian</span> parcel), links hydrologic and chemical transformation processes so that the in-stream fate of wastewater contaminants can be quantitatively evaluated. However, precise <span class="hlt">Lagrangian</span> sampling is difficult, and small deviations – such as missing the <span class="hlt">Lagrangian</span> parcel by less than 1 h – can cause large differences in measured concentrations of all dissolved compounds at downstream sites, leading to erroneous conclusions regarding in-stream processes controlling the fate and transport of wastewater contaminants. Therefore, we have developed a method termed “verified Lagrangian” sampling, which can be used to determine if the <span class="hlt">Lagrangian</span> parcel was actually sampled, and if it was not, a means for correcting the data to reflect the concentrations which would have been obtained had the <span class="hlt">Lagrangian</span> parcel been sampled. To apply the method, it is necessary to have concentration data for a number of conservative constituents from the upstream, effluent, and downstream sites, along with upstream and effluent concentrations that are constant over the short-term (typically 2–4 h). These corrections can subsequently be applied to all data, including non-conservative constituents. Finally, we</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DFDQ34007F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DFDQ34007F"><span>Uncertainty quantification in Eulerian-<span class="hlt">Lagrangian</span> models for particle-laden flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fountoulakis, Vasileios; Jacobs, Gustaaf; Udaykumar, Hs</p> <p>2017-11-01</p> <p>A common approach to ameliorate the computational burden in simulations of particle-laden flows is to use a point-particle based Eulerian-<span class="hlt">Lagrangian</span> model, which traces individual particles in their <span class="hlt">Lagrangian</span> frame and models particles as mathematical points. The particle motion is determined by Stokes drag law, which is empirically corrected for Reynolds number, Mach number and other parameters. The empirical corrections are subject to uncertainty. Treating them as random variables renders the coupled system of PDEs and ODEs stochastic. An approach to quantify the propagation of this parametric uncertainty to the particle solution variables is proposed. The approach is based on averaging of the governing equations and allows for estimation of the first moments of the quantities of interest. We demonstrate the feasibility of our proposed methodology of uncertainty quantification of particle-laden flows on one-dimensional linear and nonlinear Eulerian-<span class="hlt">Lagrangian</span> systems. This research is supported by AFOSR under Grant FA9550-16-1-0008.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhyA..486..218S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhyA..486..218S"><span>S-<span class="hlt">Lagrangian</span> dynamics of many-body systems and behavior of social groups: Dominance and hierarchy formation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sandler, U.</p> <p>2017-11-01</p> <p>In this paper, we extend our generalized <span class="hlt">Lagrangian</span> dynamics (i.e., S-<span class="hlt">Lagrangian</span> dynamics, which can be applied equally to physical and non-physical systems as per Sandler (2014)) to many-body systems. Unlike common <span class="hlt">Lagrangian</span> dynamics, this is not a trivial task. For many-body systems with S-dependent <span class="hlt">Lagrangians</span>, the <span class="hlt">Lagrangian</span> and the corresponding Hamiltonian or energy become vector functions, conjugated momenta become second-order tensors, and the system inevitably develops a hierarchical structure, even if all bodies initially have similar status and <span class="hlt">Lagrangians</span>. As an application of our theory, we consider dominance and hierarchy formation, which is present in almost all communities of living species. As a biological basis for this application, we assume that the primary motivation of a groups activity is to attempt to cope with stress arising as pressure from the environment and from intrinsic unmet needs of individuals. It has been shown that the S-<span class="hlt">Lagrangian</span> approach to a group's evolution naturally leads to formation of linear or despotic dominance hierarchies, depending on differences between individuals in coping with stress. That is, individuals that cope more readily with stress take leadership roles during the evolution. Experimental results in animal groups which support our assumption and findings are considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Lagrangian&id=EJ206977','ERIC'); return false;" href="https://eric.ed.gov/?q=Lagrangian&id=EJ206977"><span><span class="hlt">Lagrangians</span> and Systems They Describe-How Not to Treat Dissipation in Quantum Mechanics.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ray, John R.</p> <p>1979-01-01</p> <p>The author argues that a <span class="hlt">Lagrangian</span> that yields equations of motion for a damped simple harmonic oscillator does not describe this system, but a completely different physical system, and constructs a physical system that the <span class="hlt">Lagrangian</span> describes and derives some of its properties. (Author/GA)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhDT.......192W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhDT.......192W"><span>Dynamics of Multibody Systems Near <span class="hlt">Lagrangian</span> Points</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wong, Brian</p> <p></p> <p>This thesis examines the dynamics of a physically connected multi-spacecraft system in the vicinity of the <span class="hlt">Lagrangian</span> points of a Circular Restricted Three-Body System. The spacecraft system is arranged in a wheel-spoke configuration with smaller and less massive satellites connected to a central hub using truss/beams or tether connectors. The kinematics of the system is first defined, and the kinetic, gravitational potential energy and elastic potential energy of the system are derived. The Assumed Modes Method is used to discretize the continuous variables of the system, and a general set of ordinary differential equations describing the dynamics of the connectors and the central hub are obtained using the <span class="hlt">Lagrangian</span> method. The flexible body dynamics of the tethered and truss connected systems are examined using numerical simulations. The results show that these systems experienced only small elastic deflections when they are naturally librating or rotating at moderate angular velocities, and these deflections have relatively small effect on the attitude dynamics of the systems. Based on these results, it is determined that the connectors can be modeled as rigid when only the attitude dynamics of the system is of interest. The equations of motion of rigid satellites stationed at the <span class="hlt">Lagrangian</span> points are linearized, and the stability conditions of the satellite are obtained from the linear equations. The required conditions are shown to be similar to those of geocentric satellites. Study of the linear equations also revealed the resonant conditions of rigid <span class="hlt">Lagrangian</span> point satellites, when a librational natural frequency of the satellite matches the frequency of its station-keeping orbit leading to large attitude motions. For tethered satellites, the linear analysis shows that the tethers are in stable equilibrium when they lie along a line joining the two primary celestial bodies of the Three-Body System. Numerical simulations are used to study the long term</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JMP....59e2901D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JMP....59e2901D"><span>Geometric <span class="hlt">Lagrangian</span> approach to the physical degree of freedom count in field theory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Díaz, Bogar; Montesinos, Merced</p> <p>2018-05-01</p> <p>To circumvent some technical difficulties faced by the geometric <span class="hlt">Lagrangian</span> approach to the physical degree of freedom count presented in the work of Díaz, Higuita, and Montesinos [J. Math. Phys. 55, 122901 (2014)] that prevent its direct implementation to field theory, in this paper, we slightly modify the geometric <span class="hlt">Lagrangian</span> approach in such a way that its resulting version works perfectly for field theory (and for particle systems, of course). As in previous work, the current approach also allows us to directly get the <span class="hlt">Lagrangian</span> constraints, a new <span class="hlt">Lagrangian</span> formula for the counting of the number of physical degrees of freedom, the gauge transformations, and the number of first- and second-class constraints for any action principle based on a <span class="hlt">Lagrangian</span> depending on the fields and their first derivatives without performing any Dirac's canonical analysis. An advantage of this approach over the previous work is that it also allows us to handle the reducibility of the constraints and to get the off-shell gauge transformations. The theoretical framework is illustrated in 3-dimensional generalized general relativity (Palatini and Witten's exotic actions), Chern-Simons theory, 4-dimensional BF theory, and 4-dimensional general relativity given by Palatini's action with a cosmological constant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840031013&hterms=averaged+lagrangian&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Daveraged%2Blagrangian','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840031013&hterms=averaged+lagrangian&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Daveraged%2Blagrangian"><span>Macroscopic <span class="hlt">Lagrangian</span> description of warm plasmas. II Nonlinear wave interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kim, H.; Crawford, F. W.</p> <p>1983-01-01</p> <p>A macroscopic <span class="hlt">Lagrangian</span> is simplified to the adiabatic limit and expanded about equilibrium, to third order in perturbation, for three illustrative cases: one-dimensional compression parallel to the static magnetic field, two-dimensional compression perpendicular to the static magnetic field, and three-dimensional compression. As examples of the averaged-<span class="hlt">Lagrangian</span> method applied to nonlinear wave interactions, coupling coefficients are derived for interactions between two electron plasma waves and an ion acoustic wave, and between an ordinary wave, an electron plasma wave, and an ion acoustic wave.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26754057','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26754057"><span>Modified Mixed <span class="hlt">Lagrangian</span>-Eulerian Method Based on Numerical Framework of MT3DMS on Cauchy Boundary.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Suk, Heejun</p> <p>2016-07-01</p> <p>MT3DMS, a modular three-dimensional multispecies transport model, has long been a popular model in the groundwater field for simulating solute transport in the saturated zone. However, the method of characteristics (MOC), modified MOC (MMOC), and hybrid MOC (HMOC) included in MT3DMS did not treat Cauchy boundary conditions in a straightforward or rigorous manner, from a mathematical point of view. The MOC, MMOC, and HMOC regard the Cauchy boundary as a source condition. For the source, MOC, MMOC, and HMOC calculate the <span class="hlt">Lagrangian</span> concentration by setting it equal to the cell concentration at an old time level. However, the above calculation is an approximate method because it does not involve backward tracking in MMOC and HMOC or allow performing forward tracking at the source cell in MOC. To circumvent this problem, a new scheme is proposed that avoids direct calculation of the <span class="hlt">Lagrangian</span> concentration on the Cauchy boundary. The proposed method combines the numerical formulations of two different schemes, the finite element method (FEM) and the Eulerian-<span class="hlt">Lagrangian</span> method (ELM), into one global matrix equation. This study demonstrates the limitation of all MT3DMS schemes, including MOC, MMOC, HMOC, and a third-order total-variation-diminishing (TVD) scheme under Cauchy boundary conditions. By contrast, the proposed method always shows good agreement with the exact solution, regardless of the flow conditions. Finally, the successful application of the proposed method sheds light on the possible flexibility and capability of the MT3DMS to deal with the <span class="hlt">mass</span> transport problems of all flow regimes. © 2016, National Ground Water Association.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5367296','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5367296"><span>A non-conventional discontinuous <span class="hlt">Lagrangian</span> for viscous flow</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Marner, F.</p> <p>2017-01-01</p> <p>Drawing an analogy with quantum mechanics, a new <span class="hlt">Lagrangian</span> is proposed for a variational formulation of the Navier–Stokes equations which to-date has remained elusive. A key feature is that the resulting <span class="hlt">Lagrangian</span> is discontinuous in nature, posing additional challenges apropos the mathematical treatment of the related variational problem, all of which are resolvable. In addition to extending Lagrange's formalism to problems involving discontinuous behaviour, it is demonstrated that the associated equations of motion can self-consistently be interpreted within the framework of thermodynamics beyond local equilibrium, with the limiting case recovering the classical Navier–Stokes equations. Perspectives for applying the new formalism to discontinuous physical phenomena such as phase and grain boundaries, shock waves and flame fronts are provided. PMID:28386415</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28386415','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28386415"><span>A non-conventional discontinuous <span class="hlt">Lagrangian</span> for viscous flow.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Scholle, M; Marner, F</p> <p>2017-02-01</p> <p>Drawing an analogy with quantum mechanics, a new <span class="hlt">Lagrangian</span> is proposed for a variational formulation of the Navier-Stokes equations which to-date has remained elusive. A key feature is that the resulting <span class="hlt">Lagrangian</span> is discontinuous in nature, posing additional challenges apropos the mathematical treatment of the related variational problem, all of which are resolvable. In addition to extending Lagrange's formalism to problems involving discontinuous behaviour, it is demonstrated that the associated equations of motion can self-consistently be interpreted within the framework of thermodynamics beyond local equilibrium, with the limiting case recovering the classical Navier-Stokes equations. Perspectives for applying the new formalism to discontinuous physical phenomena such as phase and grain boundaries, shock waves and flame fronts are provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DFDQ15004O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DFDQ15004O"><span>Direct <span class="hlt">Lagrangian</span> tracking simulations of particles in vertically-developing atmospheric clouds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Onishi, Ryo; Kunishima, Yuichi</p> <p>2017-11-01</p> <p>We have been developing the <span class="hlt">Lagrangian</span> Cloud Simulator (LCS), which follows the so-called Euler-<span class="hlt">Lagrangian</span> framework, where flow motion and scalar transportations (i.e., temperature and humidity) are computed with the Euler method and particle motion with the <span class="hlt">Lagrangian</span> method. The LCS simulation considers the hydrodynamic interaction between approaching particles for robust collision detection. This leads to reliable simulations of collision growth of cloud droplets. Recently the activation process, in which aerosol particles become tiny liquid droplets, has been implemented in the LCS. The present LCS can therefore consider the whole warm-rain precipitation processes -activation, condensation, collision and drop precipitation. In this talk, after briefly introducing the LCS, we will show kinematic simulations using the LCS for quasi-one dimensional domain, i.e., vertically elongated 3D domain. They are compared with one-dimensional kinematic simulations using a spectral-bin cloud microphysics scheme, which is based on the Euler method. The comparisons show fairly good agreement with small discrepancies, the source of which will be presented. The <span class="hlt">Lagrangian</span> statistics, obtained for the first time for the vertical domain, will be the center of discussion. This research was supported by MEXT as ``Exploratory Challenge on Post-K computer'' (Frontiers of Basic Science: Challenging the Limits).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1422924-extended-lagrangian-excited-state-molecular-dynamics','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1422924-extended-lagrangian-excited-state-molecular-dynamics"><span>Extended <span class="hlt">Lagrangian</span> Excited State Molecular Dynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Bjorgaard, Josiah August; Sheppard, Daniel Glen; Tretiak, Sergei; ...</p> <p>2018-01-09</p> <p>In this work, an extended <span class="hlt">Lagrangian</span> framework for excited state molecular dynamics (XL-ESMD) using time-dependent self-consistent field theory is proposed. The formulation is a generalization of the extended <span class="hlt">Lagrangian</span> formulations for ground state Born–Oppenheimer molecular dynamics [Phys. Rev. Lett. 2008 100, 123004]. The theory is implemented, demonstrated, and evaluated using a time-dependent semiempirical model, though it should be generally applicable to ab initio theory. The simulations show enhanced energy stability and a significantly reduced computational cost associated with the iterative solutions of both the ground state and the electronically excited states. Relaxed convergence criteria can therefore be used both formore » the self-consistent ground state optimization and for the iterative subspace diagonalization of the random phase approximation matrix used to calculate the excited state transitions. In conclusion, the XL-ESMD approach is expected to enable numerically efficient excited state molecular dynamics for such methods as time-dependent Hartree–Fock (TD-HF), Configuration Interactions Singles (CIS), and time-dependent density functional theory (TD-DFT).« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1422924-extended-lagrangian-excited-state-molecular-dynamics','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1422924-extended-lagrangian-excited-state-molecular-dynamics"><span>Extended <span class="hlt">Lagrangian</span> Excited State Molecular Dynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bjorgaard, Josiah August; Sheppard, Daniel Glen; Tretiak, Sergei</p> <p></p> <p>In this work, an extended <span class="hlt">Lagrangian</span> framework for excited state molecular dynamics (XL-ESMD) using time-dependent self-consistent field theory is proposed. The formulation is a generalization of the extended <span class="hlt">Lagrangian</span> formulations for ground state Born–Oppenheimer molecular dynamics [Phys. Rev. Lett. 2008 100, 123004]. The theory is implemented, demonstrated, and evaluated using a time-dependent semiempirical model, though it should be generally applicable to ab initio theory. The simulations show enhanced energy stability and a significantly reduced computational cost associated with the iterative solutions of both the ground state and the electronically excited states. Relaxed convergence criteria can therefore be used both formore » the self-consistent ground state optimization and for the iterative subspace diagonalization of the random phase approximation matrix used to calculate the excited state transitions. In conclusion, the XL-ESMD approach is expected to enable numerically efficient excited state molecular dynamics for such methods as time-dependent Hartree–Fock (TD-HF), Configuration Interactions Singles (CIS), and time-dependent density functional theory (TD-DFT).« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26026433','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26026433"><span><span class="hlt">Lagrangian</span> formulation of irreversible thermodynamics and the second law of thermodynamics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Glavatskiy, K S</p> <p>2015-05-28</p> <p>We show that the equations which describe irreversible evolution of a system can be derived from a variational principle. We suggest a <span class="hlt">Lagrangian</span>, which depends on the properties of the normal and the so-called "mirror-image" system. The <span class="hlt">Lagrangian</span> is symmetric in time and therefore compatible with microscopic reversibility. The evolution equations in the normal and mirror-imaged systems are decoupled and describe therefore independent irreversible evolution of each of the systems. The second law of thermodynamics follows from a symmetry of the <span class="hlt">Lagrangian</span>. Entropy increase in the normal system is balanced by the entropy decrease in the mirror-image system, such that there exists an "integral of evolution" which is a constant. The derivation relies on the property of local equilibrium, which states that the local relations between the thermodynamic quantities in non-equilibrium are the same as in equilibrium.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730004050','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730004050"><span><span class="hlt">Lagrangian</span> methods in the analysis of nonlinear wave interactions in plasma</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Galloway, J. J.</p> <p>1972-01-01</p> <p>An averaged-<span class="hlt">Lagrangian</span> method is developed for obtaining the equations which describe the nonlinear interactions of the wave (oscillatory) and background (nonoscillatory) components which comprise a continuous medium. The method applies to monochromatic waves in any continuous medium that can be described by a <span class="hlt">Lagrangian</span> density, but is demonstrated in the context of plasma physics. The theory is presented in a more general and unified form by way of a new averaged-<span class="hlt">Lagrangian</span> formalism which simplifies the perturbation ordering procedure. Earlier theory is extended to deal with a medium distributed in velocity space and to account for the interaction of the background with the waves. The analytic steps are systematized, so as to maximize calculational efficiency. An assessment of the applicability and limitations of the method shows that it has some definite advantages over other approaches in efficiency and versatility.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DFD.H8002C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DFD.H8002C"><span><span class="hlt">Lagrangian</span> chaos in three- dimensional steady buoyancy-driven flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Contreras, Sebastian; Speetjens, Michel; Clercx, Herman</p> <p>2016-11-01</p> <p>Natural convection plays a key role in fluid dynamics owing to its ubiquitous presence in nature and industry. Buoyancy-driven flows are prototypical systems in the study of thermal instabilities and pattern formation. The differentially heated cavity problem has been widely studied for the investigation of buoyancy-induced oscillatory flow. However, far less attention has been devoted to the three-dimensional <span class="hlt">Lagrangian</span> transport properties in such flows. This study seeks to address this by investigating <span class="hlt">Lagrangian</span> transport in the steady flow inside a cubic cavity differentially-heated from the side. The theoretical and numerical analysis expands on previously reported similarities between the current flow and lid-driven flows. The <span class="hlt">Lagrangian</span> dynamics are controlled by the Péclet number (Pe) and the Prandtl number (Pr). Pe controls the behaviour qualitatively in that growing Pe progressively perturbs the integable state (Pe =0), thus paving the way to chaotic dynamics. Pr plays an entirely quantitative role in that Pr<1 and Pr>1 amplifies and diminishes, respectively, the perturbative effect of non-zero Pe. S.C. acknowledges financial support from Consejo Nacional de Ciencia y Tecnología (CONACYT).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DFDD17004A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DFDD17004A"><span>Getting Things Sorted With <span class="hlt">Lagrangian</span> Coherent Structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Atis, Severine; Peacock, Thomas; Environmental Dynamics Laboratory Team</p> <p>2014-11-01</p> <p>The dispersion of a tracer in a fluid flow is influenced by the <span class="hlt">Lagrangian</span> motion of fluid elements. Even in laminar regimes, the irregular chaotic behavior of a fluid flow can lead to effective stirring that rapidly redistributes a tracer throughout the domain. For flows with arbitrary time-dependence, the modern approach of <span class="hlt">Lagrangian</span> Coherent Structures (LCSs) provide a method for identifying the key material lines that organize flow transport. When the advected tracer particles possess a finite size and nontrivial shape, however, their dynamics can differ markedly from passive tracers, thus affecting the dispersion phenomena. We present details of numerical simulations and laboratory experiments that investigate the behavior of finite size particles in 2-dimensional chaotic flows. We show that the shape and the size of the particles alter the underlying LCSs, facilitating segregation between tracers of different shape in the same flow field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A22E..06K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A22E..06K"><span><span class="hlt">Lagrangian</span> Particle Tracking Simulation for Warm-Rain Processes in Quasi-One-Dimensional Domain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kunishima, Y.; Onishi, R.</p> <p>2017-12-01</p> <p>Conventional cloud simulations are based on the Euler method and compute each microphysics process in a stochastic way assuming infinite numbers of particles within each numerical grid. They therefore cannot provide the <span class="hlt">Lagrangian</span> statistics of individual particles in cloud microphysics (i.e., aerosol particles, cloud particles, and rain drops) nor discuss the statistical fluctuations due to finite number of particles. We here simulate the entire precipitation process of warm-rain, with tracking individual particles. We use the <span class="hlt">Lagrangian</span> Cloud Simulator (LCS), which is based on the Euler-<span class="hlt">Lagrangian</span> framework. In that framework, flow motion and scalar transportation are computed with the Euler method, and particle motion with the <span class="hlt">Lagrangian</span> one. The LCS tracks particle motions and collision events individually with considering the hydrodynamic interaction between approaching particles with a superposition method, that is, it can directly represent the collisional growth of cloud particles. It is essential for trustworthy collision detection to take account of the hydrodynamic interaction. In this study, we newly developed a stochastic model based on the Twomey cloud condensation nuclei (CCN) activation for the <span class="hlt">Lagrangian</span> tracking simulation and integrated it into the LCS. Coupling with the Euler computation for water vapour and temperature fields, the initiation and condensational growth of water droplets were computed in the <span class="hlt">Lagrangian</span> way. We applied the integrated LCS for a kinematic simulation of warm-rain processes in a vertically-elongated domain of, at largest, 0.03×0.03×3000 (m3) with horizontal periodicity. Aerosol particles with a realistic number density, 5×107 (m3), were evenly distributed over the domain at the initial state. Prescribed updraft at the early stage initiated development of a precipitating cloud. We have confirmed that the obtained bulk statistics fairly agree with those from a conventional spectral-bin scheme for a vertical column</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhLB..780..308C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhLB..780..308C"><span>Power corrections to the HTL effective <span class="hlt">Lagrangian</span> of QED</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carignano, Stefano; Manuel, Cristina; Soto, Joan</p> <p>2018-05-01</p> <p>We present compact expressions for the power corrections to the hard thermal loop (HTL) <span class="hlt">Lagrangian</span> of QED in d space dimensions. These are corrections of order (L / T) 2, valid for momenta L ≪ T, where T is the temperature. In the limit d → 3 we achieve a consistent regularization of both infrared and ultraviolet divergences, which respects the gauge symmetry of the theory. Dimensional regularization also allows us to witness subtle cancellations of infrared divergences. We also discuss how to generalize our results in the presence of a chemical potential, so as to obtain the power corrections to the hard dense loop (HDL) <span class="hlt">Lagrangian</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22525714-effect-vsr-invariant-chern-simons-lagrangian-photon-polarization','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22525714-effect-vsr-invariant-chern-simons-lagrangian-photon-polarization"><span>Effect of VSR invariant Chern-Simons <span class="hlt">Lagrangian</span> on photon polarization</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Nayak, Alekha C.; Verma, Ravindra K.; Jain, Pankaj, E-mail: acnayak@iitk.ac.in, E-mail: ravindkv@iitk.ac.in, E-mail: pkjain@iitk.ac.in</p> <p>2015-07-01</p> <p>We propose a generalization of the Chern-Simons (CS) <span class="hlt">Lagrangian</span> which is invariant under the SIM(2) transformations but not under the full Lorentz group. The generalized <span class="hlt">lagrangian</span> is also invariant under a SIM(2) gauge transformation. We study the effect of such a term on radiation propagating over cosmological distances. We find that the dominant effect of this term is to produce circular polarization as radiation propagates through space. We use the circular polarization data from distant radio sources in order to impose a limit on this term.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22458353-effect-vsr-invariant-chern-simons-lagrangian-photon-polarization','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22458353-effect-vsr-invariant-chern-simons-lagrangian-photon-polarization"><span>Effect of VSR invariant Chern-Simons <span class="hlt">Lagrangian</span> on photon polarization</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Nayak, Alekha C.; Verma, Ravindra K.; Jain, Pankaj</p> <p></p> <p>We propose a generalization of the Chern-Simons (CS) <span class="hlt">Lagrangian</span> which is invariant under the SIM(2) transformations but not under the full Lorentz group. The generalized <span class="hlt">lagrangian</span> is also invariant under a SIM(2) gauge transformation. We study the effect of such a term on radiation propagating over cosmological distances. We find that the dominant effect of this term is to produce circular polarization as radiation propagates through space. We use the circular polarization data from distant radio sources in order to impose a limit on this term.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1394871-aluminum-ray-mass-ablation-rate-measurements','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1394871-aluminum-ray-mass-ablation-rate-measurements"><span>Aluminum X-ray <span class="hlt">mass</span>-ablation rate measurements</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Kline, John L.; Hager, Jonathan D.</p> <p>2016-10-15</p> <p>Measurements of the <span class="hlt">mass</span> ablation rate of aluminum (Al) have been completed at the Omega Laser Facility. Measurements of the <span class="hlt">mass</span>-ablation rate show Al is higher than plastic (CH), comparable to high density carbon (HDC), and lower than beryllium. The <span class="hlt">mass</span>-ablation rate is consistent with predictions using a 1D <span class="hlt">Lagrangian</span> code, Helios. Lastly, the results suggest Al capsules have a reasonable ablation pressure even with a higher albedo than beryllium or carbon ablators warranting further investigation into the viability of Al capsules for ignition should be pursued.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/841567','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/841567"><span>The axion <span class="hlt">mass</span> in modular invariant supergravity</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Butter, Daniel; Gaillard, Mary K.</p> <p>2005-02-09</p> <p>When supersymmetry is broken by condensates with a single condensing gauge group, there is a nonanomalous R-symmetry that prevents the universal axion from acquiring a <span class="hlt">mass</span>. It has been argued that, in the context of supergravity, higher dimension operators will break this symmetry and may generate an axion <span class="hlt">mass</span> too large to allow the identification of the universal axion with the QCD axion. We show that such contributions to the axion <span class="hlt">mass</span> are highly suppressed in a class of models where the effective <span class="hlt">Lagrangian</span> for gaugino and matter condensation respects modular invariance (T-duality).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvC..96e4001L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvC..96e4001L"><span>The γ p →p η η reaction in an effective <span class="hlt">Lagrangian</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Bo-Chao; Chen, Shao-Fei</p> <p>2017-11-01</p> <p>In this paper, we investigate the γ p →p η η reaction within an effective <span class="hlt">Lagrangian</span> approach and isobar model. We consider the contributions from the intermediate N*(1535 ) , N*(1650 ) , N*(1710 ) , and N*(1720 ) isobars which finally decay to the N η state. It is found that the excitation of the N*(1535 ) dominates this reaction close to threshold and ρ meson exchange plays the most important role for the excitation of nucleon resonances. Therefore, this reaction offers a potentially good place to study the properties of nucleon resonances and their couplings to the N ρ channel. Predictions for angular distributions and invariant <span class="hlt">mass</span> spectra of final particles are also presented for future comparison with data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JMP....59a3510C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JMP....59a3510C"><span>Reductions of topologically massive gravity I: Hamiltonian analysis of second order degenerate <span class="hlt">Lagrangians</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ćaǧatay Uçgun, Filiz; Esen, Oǧul; Gümral, Hasan</p> <p>2018-01-01</p> <p>We present Skinner-Rusk and Hamiltonian formalisms of second order degenerate Clément and Sarıoğlu-Tekin <span class="hlt">Lagrangians</span>. The Dirac-Bergmann constraint algorithm is employed to obtain Hamiltonian realizations of <span class="hlt">Lagrangian</span> theories. The Gotay-Nester-Hinds algorithm is used to investigate Skinner-Rusk formalisms of these systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990008891','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990008891"><span>Effects of Helicity on <span class="hlt">Lagrangian</span> and Eulerian Time Correlations in Turbulence</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rubinstein, Robert; Zhou, Ye</p> <p>1998-01-01</p> <p>Taylor series expansions of turbulent time correlation functions are applied to show that helicity influences Eulerian time correlations more strongly than <span class="hlt">Lagrangian</span> time correlations: to second order in time, the helicity effect on <span class="hlt">Lagrangian</span> time correlations vanishes, but the helicity effect on Eulerian time correlations is nonzero. Fourier analysis shows that the helicity effect on Eulerian time correlations is confined to the largest inertial range scales. Some implications for sound radiation by swirling flows are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ITSP...59.3889J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ITSP...59.3889J"><span>Cooperative Convex Optimization in Networked Systems: Augmented <span class="hlt">Lagrangian</span> Algorithms With Directed Gossip Communication</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jakovetic, Dusan; Xavier, João; Moura, José M. F.</p> <p>2011-08-01</p> <p>We study distributed optimization in networked systems, where nodes cooperate to find the optimal quantity of common interest, x=x^\\star. The objective function of the corresponding optimization problem is the sum of private (known only by a node,) convex, nodes' objectives and each node imposes a private convex constraint on the allowed values of x. We solve this problem for generic connected network topologies with asymmetric random link failures with a novel distributed, decentralized algorithm. We refer to this algorithm as AL-G (augmented <span class="hlt">Lagrangian</span> gossiping,) and to its variants as AL-MG (augmented <span class="hlt">Lagrangian</span> multi neighbor gossiping) and AL-BG (augmented <span class="hlt">Lagrangian</span> broadcast gossiping.) The AL-G algorithm is based on the augmented <span class="hlt">Lagrangian</span> dual function. Dual variables are updated by the standard method of multipliers, at a slow time scale. To update the primal variables, we propose a novel, Gauss-Seidel type, randomized algorithm, at a fast time scale. AL-G uses unidirectional gossip communication, only between immediate neighbors in the network and is resilient to random link failures. For networks with reliable communication (i.e., no failures,) the simplified, AL-BG (augmented <span class="hlt">Lagrangian</span> broadcast gossiping) algorithm reduces communication, computation and data storage cost. We prove convergence for all proposed algorithms and demonstrate by simulations the effectiveness on two applications: l_1-regularized logistic regression for classification and cooperative spectrum sensing for cognitive radio networks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22415860-lagrangian-formulation-irreversible-thermodynamics-second-law-thermodynamics','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22415860-lagrangian-formulation-irreversible-thermodynamics-second-law-thermodynamics"><span><span class="hlt">Lagrangian</span> formulation of irreversible thermodynamics and the second law of thermodynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Glavatskiy, K. S.</p> <p></p> <p>We show that the equations which describe irreversible evolution of a system can be derived from a variational principle. We suggest a <span class="hlt">Lagrangian</span>, which depends on the properties of the normal and the so-called “mirror-image” system. The <span class="hlt">Lagrangian</span> is symmetric in time and therefore compatible with microscopic reversibility. The evolution equations in the normal and mirror-imaged systems are decoupled and describe therefore independent irreversible evolution of each of the systems. The second law of thermodynamics follows from a symmetry of the <span class="hlt">Lagrangian</span>. Entropy increase in the normal system is balanced by the entropy decrease in the mirror-image system, such thatmore » there exists an “integral of evolution” which is a constant. The derivation relies on the property of local equilibrium, which states that the local relations between the thermodynamic quantities in non-equilibrium are the same as in equilibrium.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1454436','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1454436"><span><span class="hlt">Lagrangian</span> space consistency relation for large scale structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Horn, Bart; Hui, Lam; Xiao, Xiao</p> <p></p> <p>Consistency relations, which relate the squeezed limit of an (N+1)-point correlation function to an N-point function, are non-perturbative symmetry statements that hold even if the associated high momentum modes are deep in the nonlinear regime and astrophysically complex. Recently, Kehagias & Riotto and Peloso & Pietroni discovered a consistency relation applicable to large scale structure. We show that this can be recast into a simple physical statement in <span class="hlt">Lagrangian</span> space: that the squeezed correlation function (suitably normalized) vanishes. This holds regardless of whether the correlation observables are at the same time or not, and regardless of whether multiple-streaming is present.more » Furthermore, the simplicity of this statement suggests that an analytic understanding of large scale structure in the nonlinear regime may be particularly promising in <span class="hlt">Lagrangian</span> space.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1454436-lagrangian-space-consistency-relation-large-scale-structure','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1454436-lagrangian-space-consistency-relation-large-scale-structure"><span><span class="hlt">Lagrangian</span> space consistency relation for large scale structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Horn, Bart; Hui, Lam; Xiao, Xiao</p> <p>2015-09-29</p> <p>Consistency relations, which relate the squeezed limit of an (N+1)-point correlation function to an N-point function, are non-perturbative symmetry statements that hold even if the associated high momentum modes are deep in the nonlinear regime and astrophysically complex. Recently, Kehagias & Riotto and Peloso & Pietroni discovered a consistency relation applicable to large scale structure. We show that this can be recast into a simple physical statement in <span class="hlt">Lagrangian</span> space: that the squeezed correlation function (suitably normalized) vanishes. This holds regardless of whether the correlation observables are at the same time or not, and regardless of whether multiple-streaming is present.more » Furthermore, the simplicity of this statement suggests that an analytic understanding of large scale structure in the nonlinear regime may be particularly promising in <span class="hlt">Lagrangian</span> space.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28113769','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28113769"><span>A Combined Eulerian-<span class="hlt">Lagrangian</span> Data Representation for Large-Scale Applications.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sauer, Franz; Xie, Jinrong; Ma, Kwan-Liu</p> <p>2017-10-01</p> <p>The Eulerian and <span class="hlt">Lagrangian</span> reference frames each provide a unique perspective when studying and visualizing results from scientific systems. As a result, many large-scale simulations produce data in both formats, and analysis tasks that simultaneously utilize information from both representations are becoming increasingly popular. However, due to their fundamentally different nature, drawing correlations between these data formats is a computationally difficult task, especially in a large-scale setting. In this work, we present a new data representation which combines both reference frames into a joint Eulerian-<span class="hlt">Lagrangian</span> format. By reorganizing <span class="hlt">Lagrangian</span> information according to the Eulerian simulation grid into a "unit cell" based approach, we can provide an efficient out-of-core means of sampling, querying, and operating with both representations simultaneously. We also extend this design to generate multi-resolution subsets of the full data to suit the viewer's needs and provide a fast flow-aware trajectory construction scheme. We demonstrate the effectiveness of our method using three large-scale real world scientific datasets and provide insight into the types of performance gains that can be achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1256634-lagrangian-geometrical-optics-nonadiabatic-vector-waves-spin-particles','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1256634-lagrangian-geometrical-optics-nonadiabatic-vector-waves-spin-particles"><span><span class="hlt">Lagrangian</span> geometrical optics of nonadiabatic vector waves and spin particles</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Ruiz, D. E.; Dodin, I. Y.</p> <p>2015-07-29</p> <p>Linear vector waves, both quantum and classical, experience polarization-driven bending of ray trajectories and polarization dynamics that can be interpreted as the precession of the "wave spin". Here, both phenomena are governed by an effective gauge Hamiltonian vanishing in leading-order geometrical optics. This gauge Hamiltonian can be recognized as a generalization of the Stern-Gerlach Hamiltonian that is commonly known for spin-1/2 quantum particles. The corresponding reduced <span class="hlt">Lagrangians</span> for continuous nondissipative waves and their geometrical-optics rays are derived from the fundamental wave <span class="hlt">Lagrangian</span>. The resulting Euler-Lagrange equations can describe simultaneous interactions of N resonant modes, where N is arbitrary, and leadmore » to equations for the wave spin, which happens to be an (N 2 - 1)-dimensional spin vector. As a special case, classical equations for a Dirac particle (N = 2) are deduced formally, without introducing additional postulates or interpretations, from the Dirac quantum <span class="hlt">Lagrangian</span> with the Pauli term. The model reproduces the Bargmann-Michel-Telegdi equations with added Stern-Gerlach force.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Lagrangian&id=EJ196862','ERIC'); return false;" href="https://eric.ed.gov/?q=Lagrangian&id=EJ196862"><span>Examination of Eulerian and <span class="hlt">Lagrangian</span> Coordinate Systems.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Remillard, Wilfred J.</p> <p>1978-01-01</p> <p>Studies the relationship between Eulerian and <span class="hlt">Lagrangian</span> coordinate systems with the help of computer plots of variables such as density and particle displacement. Gives examples which illustrate the differences in the shape of a traveling wave as seen by observers in the two systems. (Author/GA)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980237451','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980237451"><span>Eulerian-<span class="hlt">Lagrangian</span> Simulations of Transonic Flutter Instabilities</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bendiksen, Oddvar O.</p> <p>1994-01-01</p> <p>This paper presents an overview of recent applications of Eulerian-<span class="hlt">Lagrangian</span> computational schemes in simulating transonic flutter instabilities. This approach, the fluid-structure system is treated as a single continuum dynamics problem, by switching from an Eulerian to a <span class="hlt">Lagrangian</span> formulation at the fluid-structure boundary. This computational approach effectively eliminates the phase integration errors associated with previous methods, where the fluid and structure are integrated sequentially using different schemes. The formulation is based on Hamilton's Principle in mixed coordinates, and both finite volume and finite element discretization schemes are considered. Results from numerical simulations of transonic flutter instabilities are presented for isolated wings, thin panels, and turbomachinery blades. The results suggest that the method is capable of reproducing the energy exchange between the fluid and the structure with significantly less error than existing methods. Localized flutter modes and panel flutter modes involving traveling waves can also be simulated effectively with no a priori knowledge of the type of instability involved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Ap%26SS.353..457N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Ap%26SS.353..457N"><span>Stability of triangular <span class="hlt">lagrangian</span> points in elliptical restricted three body problem under the radiating binary systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Narayan, A.; Singh, Nutan</p> <p>2014-10-01</p> <p>This paper studies the stability of Triangular <span class="hlt">Lagrangian</span> points in the model of elliptical restricted three body problem, under the assumption that both the primaries are radiating. The model proposed is applicable to the well known binary systems Achird, Luyten, αCen AB, Kruger-60, Xi-Bootis. Conditional stability of the motion around the triangular points exists for 0≤ μ≤ μ ∗, where μ is the <span class="hlt">mass</span> ratio. The method of averaging due to Grebenikov has been exploited throughout the analysis of stability of the system. The critical <span class="hlt">mass</span> ratio depends on the combined effects of radiation of both the primaries and eccentricity of this orbit. It is found by adopting the simulation technique that the range of stability decreases as the radiation pressure parameter increases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25215826','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25215826"><span>Statistical scaling of pore-scale <span class="hlt">Lagrangian</span> velocities in natural porous media.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Siena, M; Guadagnini, A; Riva, M; Bijeljic, B; Pereira Nunes, J P; Blunt, M J</p> <p>2014-08-01</p> <p>We investigate the scaling behavior of sample statistics of pore-scale <span class="hlt">Lagrangian</span> velocities in two different rock samples, Bentheimer sandstone and Estaillades limestone. The samples are imaged using x-ray computer tomography with micron-scale resolution. The scaling analysis relies on the study of the way qth-order sample structure functions (statistical moments of order q of absolute increments) of <span class="hlt">Lagrangian</span> velocities depend on separation distances, or lags, traveled along the mean flow direction. In the sandstone block, sample structure functions of all orders exhibit a power-law scaling within a clearly identifiable intermediate range of lags. Sample structure functions associated with the limestone block display two diverse power-law regimes, which we infer to be related to two overlapping spatially correlated structures. In both rocks and for all orders q, we observe linear relationships between logarithmic structure functions of successive orders at all lags (a phenomenon that is typically known as extended power scaling, or extended self-similarity). The scaling behavior of <span class="hlt">Lagrangian</span> velocities is compared with the one exhibited by porosity and specific surface area, which constitute two key pore-scale geometric observables. The statistical scaling of the local velocity field reflects the behavior of these geometric observables, with the occurrence of power-law-scaling regimes within the same range of lags for sample structure functions of <span class="hlt">Lagrangian</span> velocity, porosity, and specific surface area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015CNSNS..20..516I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015CNSNS..20..516I"><span>Transport induced by mean-eddy interaction: I. Theory, and relation to <span class="hlt">Lagrangian</span> lobe dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ide, Kayo; Wiggins, Stephen</p> <p>2015-02-01</p> <p>In this paper we develop a method for the estimation of Transport Induced by the Mean-Eddy interaction (TIME) in two-dimensional unsteady flows. The method is based on the dynamical systems approach to fluid transport and can be viewed as a hybrid combination of <span class="hlt">Lagrangian</span> and Eulerian methods. The (Eulerian) boundaries across which we consider (<span class="hlt">Lagrangian</span>) transport are kinematically defined by appropriately chosen streamlines of the mean flow. By evaluating the impact of the mean-eddy interaction on transport, the TIME method can be used as a diagnostic tool for transport processes that occur during a specified time interval along a specified boundary segment. We introduce two types of TIME functions: one that quantifies the accumulation of flow properties and another that measures the displacement of the transport geometry. The spatial geometry of transport is described by the so-called pseudo-lobes, and temporal evolution of transport by their dynamics. In the case where the TIME functions are evaluated along a separatrix, the pseudo-lobes have a relationship to the lobes of <span class="hlt">Lagrangian</span> transport theory. In fact, one of the TIME functions is identical to the Melnikov function that is used to measure the distance, at leading order in a small parameter, between the two invariant manifolds that define the <span class="hlt">Lagrangian</span> lobes. We contrast the similarities and differences between the TIME and <span class="hlt">Lagrangian</span> lobe dynamics in detail. An application of the TIME method is carried out for inter-gyre transport in the wind-driven oceanic circulation model and a comparison with the <span class="hlt">Lagrangian</span> transport theory is made.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DPPN11052C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DPPN11052C"><span>Higher-Order Advection-Based Remap of Magnetic Fields in an Arbitrary <span class="hlt">Lagrangian</span>-Eulerian Code</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cornille, Brian; White, Dan</p> <p>2017-10-01</p> <p>We will present methods formulated for the Eulerian advection stage of an arbitrary <span class="hlt">Lagrangian</span>-Eulerian code for the new addition of magnetohydrodynamic (MHD) effects. The various physical fields are advanced in time using a <span class="hlt">Lagrangian</span> formulation of the system. When this <span class="hlt">Lagrangian</span> motion produces substantial distortion of the mesh, it can be difficult or impossible to progress the simulation forward. This is overcome by relaxation of the mesh while the physical fields are frozen. The code has already successfully been extended to include evolution of magnetic field diffusion during the <span class="hlt">Lagrangian</span> motion stage. This magnetic field is discretized using an H(div) compatible finite element basis. The advantage of this basis is that the divergence-free constraint of magnetic fields is maintained exactly during the <span class="hlt">Lagrangian</span> motion evolution. Our goal is to preserve this property during Eulerian advection as well. We will demonstrate this property and the importance of MHD effects in several numerical experiments. In pulsed-power experiments magnetic fields may be imposed or spontaneously generated. When these magnetic fields are present, the evolution of the experiment may differ from a comparable configuration without magnetic fields. Prepared by LLNL under Contract DE-AC52-07NA27344. Supported by DOE CSGF under Grant Number DE-FG02-97ER25308.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3462029','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3462029"><span><span class="hlt">Lagrangian</span> transport properties of pulmonary interfacial flows</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Smith, Bradford J.; Lukens, Sarah; Yamaguchi, Eiichiro; Gaver, Donald P.</p> <p>2012-01-01</p> <p>Disease states characterized by airway fluid occlusion and pulmonary surfactant insufficiency, such as respiratory distress syndrome, have a high mortality rate. Understanding the mechanics of airway reopening, particularly involving surfactant transport, may provide an avenue to increase patient survival via optimized mechanical ventilation waveforms. We model the occluded airway as a liquid-filled rigid tube with the fluid phase displaced by a finger of air that propagates with both mean and sinusoidal velocity components. Finite-time Lyapunov exponent (FTLE) fields are employed to analyse the convective transport characteristics, taking note of <span class="hlt">Lagrangian</span> coherent structures (LCSs) and their effects on transport. The <span class="hlt">Lagrangian</span> perspective of these techniques reveals flow characteristics that are not readily apparent by observing Eulerian measures. These analysis techniques are applied to surfactant-free velocity fields determined computationally, with the boundary element method, and measured experimentally with micro particle image velocimetry (μ-PIV). We find that the LCS divides the fluid into two regimes, one advected upstream (into the thin residual film) and the other downstream ahead of the advancing bubble. At higher oscillatory frequencies particles originating immediately inside the LCS experience long residence times at the air–liquid interface, which may be conducive to surfactant transport. At high frequencies a well-mixed attractor region is identified; this volume of fluid cyclically travels along the interface and into the bulk fluid. The <span class="hlt">Lagrangian</span> analysis is applied to velocity data measured with 0.01 mg ml−1 of the clinical pulmonary surfactant Infasurf in the bulk fluid, demonstrating flow field modifications with respect to the surfactant-free system that were not visible in the Eulerian frame. PMID:23049141</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IJBC...2730001L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IJBC...2730001L"><span>A Theoretical Framework for <span class="hlt">Lagrangian</span> Descriptors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lopesino, C.; Balibrea-Iniesta, F.; García-Garrido, V. J.; Wiggins, S.; Mancho, A. M.</p> <p></p> <p>This paper provides a theoretical background for <span class="hlt">Lagrangian</span> Descriptors (LDs). The goal of achieving rigorous proofs that justify the ability of LDs to detect invariant manifolds is simplified by introducing an alternative definition for LDs. The definition is stated for n-dimensional systems with general time dependence, however we rigorously prove that this method reveals the stable and unstable manifolds of hyperbolic points in four particular 2D cases: a hyperbolic saddle point for linear autonomous systems, a hyperbolic saddle point for nonlinear autonomous systems, a hyperbolic saddle point for linear nonautonomous systems and a hyperbolic saddle point for nonlinear nonautonomous systems. We also discuss further rigorous results which show the ability of LDs to highlight additional invariants sets, such as n-tori. These results are just a simple extension of the ergodic partition theory which we illustrate by applying this methodology to well-known examples, such as the planar field of the harmonic oscillator and the 3D ABC flow. Finally, we provide a thorough discussion on the requirement of the objectivity (frame-invariance) property for tools designed to reveal phase space structures and their implications for <span class="hlt">Lagrangian</span> descriptors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JHEP...04..016H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JHEP...04..016H"><span>Sigma decomposition: the CP-odd <span class="hlt">Lagrangian</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hierro, I. M.; Merlo, L.; Rigolin, S.</p> <p>2016-04-01</p> <p>In Alonso et al., JHEP 12 (2014) 034, the CP-even sector of the effective chiral <span class="hlt">Lagrangian</span> for a generic composite Higgs model with a symmetric coset has been constructed, up to four momenta. In this paper, the CP-odd couplings are studied within the same context. If only the Standard Model bosonic sources of custodial symmetry breaking are considered, then at most six independent operators form a basis. One of them is the weak- θ term linked to non-perturbative sources of CP violation, while the others describe CP-odd perturbative couplings between the Standard Model gauge bosons and an Higgs-like scalar belonging to the Goldstone boson sector. The procedure is then applied to three distinct exemplifying frameworks: the original SU(5)/SO(5) Georgi-Kaplan model, the minimal custodial-preserving SO(5)/SO(4) model and the minimal SU(3)/(SU(2) × U(1)) model, which intrinsically breaks custodial symmetry. Moreover, the projection of the high-energy electroweak effective theory to the low-energy chiral effective <span class="hlt">Lagrangian</span> for a dynamical Higgs is performed, uncovering strong relations between the operator coefficients and pinpointing the differences with the elementary Higgs scenario.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930064132&hterms=Lagrangian&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DLagrangian','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930064132&hterms=Lagrangian&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DLagrangian"><span>Reduction of numerical diffusion in three-dimensional vortical flows using a coupled Eulerian/<span class="hlt">Lagrangian</span> solution procedure</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Felici, Helene M.; Drela, Mark</p> <p>1993-01-01</p> <p>A new approach based on the coupling of an Eulerian and a <span class="hlt">Lagrangian</span> solver, aimed at reducing the numerical diffusion errors of standard Eulerian time-marching finite-volume solvers, is presented. The approach is applied to the computation of the secondary flow in two bent pipes and the flow around a 3D wing. Using convective point markers the <span class="hlt">Lagrangian</span> approach provides a correction of the basic Eulerian solution. The Eulerian flow in turn integrates in time the <span class="hlt">Lagrangian</span> state-vector. A comparison of coarse and fine grid Eulerian solutions makes it possible to identify numerical diffusion. It is shown that the Eulerian/<span class="hlt">Lagrangian</span> approach is an effective method for reducing numerical diffusion errors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26826855','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26826855"><span><span class="hlt">Lagrangian</span> statistics in weakly forced two-dimensional turbulence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rivera, Michael K; Ecke, Robert E</p> <p>2016-01-01</p> <p>Measurements of <span class="hlt">Lagrangian</span> single-point and multiple-point statistics in a quasi-two-dimensional stratified layer system are reported. The system consists of a layer of salt water over an immiscible layer of Fluorinert and is forced electromagnetically so that mean-squared vorticity is injected at a well-defined spatial scale ri. Simultaneous cascades develop in which enstrophy flows predominately to small scales whereas energy cascades, on average, to larger scales. <span class="hlt">Lagrangian</span> correlations and one- and two-point displacements are measured for random initial conditions and for initial positions within topological centers and saddles. Some of the behavior of these quantities can be understood in terms of the trapping characteristics of long-lived centers, the slow motion near strong saddles, and the rapid fluctuations outside of either centers or saddles. We also present statistics of <span class="hlt">Lagrangian</span> velocity fluctuations using energy spectra in frequency space and structure functions in real space. We compare with complementary Eulerian velocity statistics. We find that simultaneous inverse energy and enstrophy ranges present in spectra are not directly echoed in real-space moments of velocity difference. Nevertheless, the spectral ranges line up well with features of moment ratios, indicating that although the moments are not exhibiting unambiguous scaling, the behavior of the probability distribution functions is changing over short ranges of length scales. Implications for understanding weakly forced 2D turbulence with simultaneous inverse and direct cascades are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1351187','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1351187"><span><span class="hlt">Lagrangian</span> statistics in weakly forced two-dimensional turbulence</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Rivera, Michael K.; Ecke, Robert E.</p> <p></p> <p>Measurements of <span class="hlt">Lagrangian</span> single-point and multiple-point statistics in a quasi-two-dimensional stratified layer system are reported. The system consists of a layer of salt water over an immiscible layer of Fluorinert and is forced electromagnetically so that mean-squared vorticity is injected at a well-defined spatial scale r i. Simultaneous cascades develop in which enstrophy flows predominately to small scales whereas energy cascades, on average, to larger scales. <span class="hlt">Lagrangian</span> correlations and one- and two-point displacements are measured for random initial conditions and for initial positions within topological centers and saddles. Some of the behavior of these quantities can be understood in termsmore » of the trapping characteristics of long-lived centers, the slow motion near strong saddles, and the rapid fluctuations outside of either centers or saddles. We also present statistics of <span class="hlt">Lagrangian</span> velocity fluctuations using energy spectra in frequency space and structure functions in real space. We compare with complementary Eulerian velocity statistics. We find that simultaneous inverse energy and enstrophy ranges present in spectra are not directly echoed in real-space moments of velocity difference. Nevertheless, the spectral ranges line up well with features of moment ratios, indicating that although the moments are not exhibiting unambiguous scaling, the behavior of the probability distribution functions is changing over short ranges of length scales. Furthermore, implications for understanding weakly forced 2D turbulence with simultaneous inverse and direct cascades are discussed.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NPGeo..24..661P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NPGeo..24..661P"><span>Network-based study of <span class="hlt">Lagrangian</span> transport and mixing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Padberg-Gehle, Kathrin; Schneide, Christiane</p> <p>2017-10-01</p> <p>Transport and mixing processes in fluid flows are crucially influenced by coherent structures and the characterization of these <span class="hlt">Lagrangian</span> objects is a topic of intense current research. While established mathematical approaches such as variational methods or transfer-operator-based schemes require full knowledge of the flow field or at least high-resolution trajectory data, this information may not be available in applications. Recently, different computational methods have been proposed to identify coherent behavior in flows directly from <span class="hlt">Lagrangian</span> trajectory data, that is, numerical or measured time series of particle positions in a fluid flow. In this context, spatio-temporal clustering algorithms have been proven to be very effective for the extraction of coherent sets from sparse and possibly incomplete trajectory data. Inspired by these recent approaches, we consider an unweighted, undirected network, where <span class="hlt">Lagrangian</span> particle trajectories serve as network nodes. A link is established between two nodes if the respective trajectories come close to each other at least once in the course of time. Classical graph concepts are then employed to analyze the resulting network. In particular, local network measures such as the node degree, the average degree of neighboring nodes, and the clustering coefficient serve as indicators of highly mixing regions, whereas spectral graph partitioning schemes allow us to extract coherent sets. The proposed methodology is very fast to run and we demonstrate its applicability in two geophysical flows - the Bickley jet as well as the Antarctic stratospheric polar vortex.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1351187-lagrangian-statistics-weakly-forced-two-dimensional-turbulence','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1351187-lagrangian-statistics-weakly-forced-two-dimensional-turbulence"><span><span class="hlt">Lagrangian</span> statistics in weakly forced two-dimensional turbulence</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Rivera, Michael K.; Ecke, Robert E.</p> <p>2016-01-14</p> <p>Measurements of <span class="hlt">Lagrangian</span> single-point and multiple-point statistics in a quasi-two-dimensional stratified layer system are reported. The system consists of a layer of salt water over an immiscible layer of Fluorinert and is forced electromagnetically so that mean-squared vorticity is injected at a well-defined spatial scale r i. Simultaneous cascades develop in which enstrophy flows predominately to small scales whereas energy cascades, on average, to larger scales. <span class="hlt">Lagrangian</span> correlations and one- and two-point displacements are measured for random initial conditions and for initial positions within topological centers and saddles. Some of the behavior of these quantities can be understood in termsmore » of the trapping characteristics of long-lived centers, the slow motion near strong saddles, and the rapid fluctuations outside of either centers or saddles. We also present statistics of <span class="hlt">Lagrangian</span> velocity fluctuations using energy spectra in frequency space and structure functions in real space. We compare with complementary Eulerian velocity statistics. We find that simultaneous inverse energy and enstrophy ranges present in spectra are not directly echoed in real-space moments of velocity difference. Nevertheless, the spectral ranges line up well with features of moment ratios, indicating that although the moments are not exhibiting unambiguous scaling, the behavior of the probability distribution functions is changing over short ranges of length scales. Furthermore, implications for understanding weakly forced 2D turbulence with simultaneous inverse and direct cascades are discussed.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AtmEn..42..466M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AtmEn..42..466M"><span>A <span class="hlt">Lagrangian</span> particle model to predict the airborne spread of foot-and-mouth disease virus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mayer, D.; Reiczigel, J.; Rubel, F.</p> <p></p> <p>Airborne spread of bioaerosols in the boundary layer over a complex terrain is simulated using a <span class="hlt">Lagrangian</span> particle model, and applied to modelling the airborne spread of foot-and-mouth disease (FMD) virus. Two case studies are made with study domains located in a hilly region in the northwest of the Styrian capital Graz, the second largest town in Austria. Mountainous terrain as well as inhomogeneous and time varying meteorological conditions prevent from application of so far used Gaussian dispersion models, while the proposed model can handle these realistically. In the model, trajectories of several thousands of particles are computed and the distribution of virus concentration near the ground is calculated. This allows to assess risk of infection areas with respect to animal species of interest, such as cattle, swine or sheep. Meteorological input data like wind field and other variables necessary to compute turbulence were taken from the new pre-operational version of the non-hydrostatic numerical weather prediction model LMK ( Lokal-Modell-Kürzestfrist) running at the German weather service DWD ( Deutscher Wetterdienst). The LMK model provides meteorological parameters with a spatial resolution of about 2.8 km. To account for the spatial resolution of 400 m used by the <span class="hlt">Lagrangian</span> particle model, the initial wind field is interpolated upon the finer grid by a <span class="hlt">mass</span> consistent interpolation method. Case studies depict a significant influence of local wind systems on the spread of virus. Higher virus concentrations at the upwind side of the hills and marginal concentrations in the lee are well observable, as well as canalization effects by valleys. The study demonstrates that the <span class="hlt">Lagrangian</span> particle model is an appropriate tool for risk assessment of airborne spread of virus by taking into account the realistic orographic and meteorological conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GMD....11..103G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GMD....11..103G"><span><span class="hlt">Lagrangian</span> condensation microphysics with Twomey CCN activation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grabowski, Wojciech W.; Dziekan, Piotr; Pawlowska, Hanna</p> <p>2018-01-01</p> <p>We report the development of a novel <span class="hlt">Lagrangian</span> microphysics methodology for simulations of warm ice-free clouds. The approach applies the traditional Eulerian method for the momentum and continuous thermodynamic fields such as the temperature and water vapor mixing ratio, and uses <span class="hlt">Lagrangian</span> <q>super-droplets</q> to represent condensed phase such as cloud droplets and drizzle or rain drops. In other applications of the <span class="hlt">Lagrangian</span> warm-rain microphysics, the super-droplets outside clouds represent unactivated cloud condensation nuclei (CCN) that become activated upon entering a cloud and can further grow through diffusional and collisional processes. The original methodology allows for the detailed study of not only effects of CCN on cloud microphysics and dynamics, but also CCN processing by a cloud. However, when cloud processing is not of interest, a simpler and computationally more efficient approach can be used with super-droplets forming only when CCN is activated and no super-droplet existing outside a cloud. This is possible by applying the Twomey activation scheme where the local supersaturation dictates the concentration of cloud droplets that need to be present inside a cloudy volume, as typically used in Eulerian bin microphysics schemes. Since a cloud volume is a small fraction of the computational domain volume, the Twomey super-droplets provide significant computational advantage when compared to the original super-droplet methodology. Additional advantage comes from significantly longer time steps that can be used when modeling of CCN deliquescence is avoided. Moreover, other formulation of the droplet activation can be applied in case of low vertical resolution of the host model, for instance, linking the concentration of activated cloud droplets to the local updraft speed. This paper discusses the development and testing of the Twomey super-droplet methodology, focusing on the activation and diffusional growth. Details of the activation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22525326-lagrangian-space-consistency-relation-large-scale-structure','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22525326-lagrangian-space-consistency-relation-large-scale-structure"><span><span class="hlt">Lagrangian</span> space consistency relation for large scale structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Horn, Bart; Hui, Lam; Xiao, Xiao, E-mail: bh2478@columbia.edu, E-mail: lh399@columbia.edu, E-mail: xx2146@columbia.edu</p> <p></p> <p>Consistency relations, which relate the squeezed limit of an (N+1)-point correlation function to an N-point function, are non-perturbative symmetry statements that hold even if the associated high momentum modes are deep in the nonlinear regime and astrophysically complex. Recently, Kehagias and Riotto and Peloso and Pietroni discovered a consistency relation applicable to large scale structure. We show that this can be recast into a simple physical statement in <span class="hlt">Lagrangian</span> space: that the squeezed correlation function (suitably normalized) vanishes. This holds regardless of whether the correlation observables are at the same time or not, and regardless of whether multiple-streaming is present.more » The simplicity of this statement suggests that an analytic understanding of large scale structure in the nonlinear regime may be particularly promising in <span class="hlt">Lagrangian</span> space.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1422338-movement-collision-lagrangian-particles-hydro-turbine-intakes-acasestudy','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1422338-movement-collision-lagrangian-particles-hydro-turbine-intakes-acasestudy"><span>Movement and collision of <span class="hlt">Lagrangian</span> particles in hydro-turbine intakes: a case study</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Romero-Gomez, Pedro; Richmond, Marshall C.</p> <p></p> <p>Studies of the stress/survival of migratory fish during downstream passage through operating hydro-turbines are normally conducted to determine the fish-friendliness of units. One field approach consisting of recording extreme hydraulics with autonomous sensors is largely sensitive to the conditions of sensor release and the initial trajectories at the turbine intake. This study applies a modelling strategy based on flow simulations using computational fluid dynamics and <span class="hlt">Lagrangian</span> particle tracking to represent the travel of live fish and autonomous sensor devices through hydro-turbine intakes. For the flow field calculation, the simulations were conducted with both a time-averaging turbulence model and an eddy-resolvingmore » technique. For the particle tracking calculation, different modelling assumptions for turbulence forcing, <span class="hlt">mass</span> formulation, buoyancy, and release condition were tested. The modelling assumptions are evaluated with respect to data sets collected using a laboratory physical model and an autonomous sensor device deployed at Ice Harbor Dam (Snake River, State of Washington, U.S.A.) at the same discharge and release point as in the present computer simulations. We found an acceptable agreement between the simulated results and observed data and discuss relevant features of <span class="hlt">Lagrangian</span> particle movement that are critical in turbine design and in the experimental design of field studies.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JKPS...72.1287K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JKPS...72.1287K"><span>Renormalization Group Invariance of the Pole <span class="hlt">Mass</span> in the Multi-Higgs System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Chungku</p> <p>2018-06-01</p> <p>We have investigated the renormalization group running of the pole <span class="hlt">mass</span> in the multi-Higgs theory in two different types of gauge fixing conditions. The pole <span class="hlt">mass</span>, when expressed in terms of the <span class="hlt">Lagrangian</span> parameters, turns out to be invariant under the renormalization group with the beta and gamma functions of the symmetric phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhR...392..279S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhR...392..279S"><span><span class="hlt">Lagrangian</span> fluid description with simple applications in compressible plasma and gas dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schamel, Hans</p> <p>2004-03-01</p> <p>The <span class="hlt">Lagrangian</span> fluid description, in which the dynamics of fluids is formulated in terms of trajectories of fluid elements, not only presents an alternative to the more common Eulerian description but has its own merits and advantages. This aspect, which seems to be not fully explored yet, is getting increasing attention in fluid dynamics and related areas as <span class="hlt">Lagrangian</span> codes and experimental techniques are developed utilizing the <span class="hlt">Lagrangian</span> point of view with the ultimate goal of a deeper understanding of flow dynamics. In this tutorial review we report on recent progress made in the analysis of compressible, more or less perfect flows such as plasmas and dilute gases. The equations of motion are exploited to get further insight into the formation and evolution of coherent structures, which often exhibit a singular or collapse type behavior occurring in finite time. It is argued that this technique of solution has a broad applicability due to the simplicity and generality of equations used. The focus is on four different topics, the physics of which being governed by simple fluid equations subject to initial and/or boundary conditions. Whenever possible also experimental results are mentioned. In the expansion of a semi-infinite plasma into a vacuum the energetic ion peak propagating supersonically towards the vacuum-as seen in laboratory experiments-is interpreted by means of the <span class="hlt">Lagrangian</span> fluid description as a relic of a wave breaking scenario of the corresponding inviscid ion dynamics. The inclusion of viscosity is shown numerically to stabilize the associated density collapse giving rise to a well defined fast ion peak reminiscent of adhesive matter. In purely convection driven flows the <span class="hlt">Lagrangian</span> flow velocity is given by its initial value and hence the <span class="hlt">Lagrangian</span> velocity gradient tensor can be evaluated accurately to find out the appearance of singularities in density and vorticity and the emergence of new structures such as wavelets in one-dimension (1D</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26328576','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26328576"><span>Quantitative flow analysis of swimming dynamics with coherent <span class="hlt">Lagrangian</span> vortices.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huhn, F; van Rees, W M; Gazzola, M; Rossinelli, D; Haller, G; Koumoutsakos, P</p> <p>2015-08-01</p> <p>Undulatory swimmers flex their bodies to displace water, and in turn, the flow feeds back into the dynamics of the swimmer. At moderate Reynolds number, the resulting flow structures are characterized by unsteady separation and alternating vortices in the wake. We use the flow field from simulations of a two-dimensional, incompressible viscous flow of an undulatory, self-propelled swimmer and detect the coherent <span class="hlt">Lagrangian</span> vortices in the wake to dissect the driving momentum transfer mechanisms. The detected material vortex boundary encloses a <span class="hlt">Lagrangian</span> control volume that serves to track back the vortex fluid and record its circulation and momentum history. We consider two swimming modes: the C-start escape and steady anguilliform swimming. The backward advection of the coherent <span class="hlt">Lagrangian</span> vortices elucidates the geometry of the vorticity field and allows for monitoring the gain and decay of circulation and momentum transfer in the flow field. For steady swimming, momentum oscillations of the fish can largely be attributed to the momentum exchange with the vortex fluid. For the C-start, an additionally defined jet fluid region turns out to balance the high momentum change of the fish during the rapid start.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23679366','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23679366"><span><span class="hlt">Lagrangian</span> single-particle turbulent statistics through the Hilbert-Huang transform.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huang, Yongxiang; Biferale, Luca; Calzavarini, Enrico; Sun, Chao; Toschi, Federico</p> <p>2013-04-01</p> <p>The Hilbert-Huang transform is applied to analyze single-particle <span class="hlt">Lagrangian</span> velocity data from numerical simulations of hydrodynamic turbulence. The velocity trajectory is described in terms of a set of intrinsic mode functions C(i)(t) and of their instantaneous frequency ω(i)(t). On the basis of this decomposition we define the ω-conditioned statistical moments of the C(i) modes, named q-order Hilbert spectra (HS). We show that such quantities have enhanced scaling properties as compared to traditional Fourier transform- or correlation-based (structure functions) statistical indicators, thus providing better insights into the turbulent energy transfer process. We present clear empirical evidence that the energylike quantity, i.e., the second-order HS, displays a linear scaling in time in the inertial range, as expected from a dimensional analysis. We also measure high-order moment scaling exponents in a direct way, without resorting to the extended self-similarity procedure. This leads to an estimate of the <span class="hlt">Lagrangian</span> structure function exponents which are consistent with the multifractal prediction in the <span class="hlt">Lagrangian</span> frame as proposed by Biferale et al. [Phys. Rev. Lett. 93, 064502 (2004)].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760014401','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760014401"><span>Experimental design for drifting buoy <span class="hlt">Lagrangian</span> test</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Saunders, P. M.</p> <p>1975-01-01</p> <p>A test of instrumentation fabricated to measure the performance of a free drifting buoy as a (<span class="hlt">Lagrangian</span>) current meter is described. Specifically it is proposed to distinguish between the trajectory of a drogued buoy and the trajectory of the water at the level of the drogue by measuring the flow relative to the drogue.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JCoPh.362....1S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JCoPh.362....1S"><span><span class="hlt">Lagrangian</span> particle method for compressible fluid dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Samulyak, Roman; Wang, Xingyu; Chen, Hsin-Chiang</p> <p>2018-06-01</p> <p>A new <span class="hlt">Lagrangian</span> particle method for solving Euler equations for compressible inviscid fluid or gas flows is proposed. Similar to smoothed particle hydrodynamics (SPH), the method represents fluid cells with <span class="hlt">Lagrangian</span> particles and is suitable for the simulation of complex free surface/multiphase flows. The main contributions of our method, which is different from SPH in all other aspects, are (a) significant improvement of approximation of differential operators based on a polynomial fit via weighted least squares approximation and the convergence of prescribed order, (b) a second-order particle-based algorithm that reduces to the first-order upwind method at local extremal points, providing accuracy and long term stability, and (c) more accurate resolution of entropy discontinuities and states at free interfaces. While the method is consistent and convergent to a prescribed order, the conservation of momentum and energy is not exact and depends on the convergence order. The method is generalizable to coupled hyperbolic-elliptic systems. Numerical verification tests demonstrating the convergence order are presented as well as examples of complex multiphase flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoRL..45..891D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoRL..45..891D"><span><span class="hlt">Lagrangian</span> Timescales of Southern Ocean Upwelling in a Hierarchy of Model Resolutions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Drake, Henri F.; Morrison, Adele K.; Griffies, Stephen M.; Sarmiento, Jorge L.; Weijer, Wilbert; Gray, Alison R.</p> <p>2018-01-01</p> <p>In this paper we study upwelling pathways and timescales of Circumpolar Deep Water (CDW) in a hierarchy of models using a <span class="hlt">Lagrangian</span> particle tracking method. <span class="hlt">Lagrangian</span> timescales of CDW upwelling decrease from 87 years to 31 years to 17 years as the ocean resolution is refined from 1° to 0.25° to 0.1°. We attribute some of the differences in timescale to the strength of the eddy fields, as demonstrated by temporally degrading high-resolution model velocity fields. Consistent with the timescale dependence, we find that an average <span class="hlt">Lagrangian</span> particle completes 3.2 circumpolar loops in the 1° model in comparison to 0.9 loops in the 0.1° model. These differences suggest that advective timescales and thus interbasin merging of upwelling CDW may be overestimated by coarse-resolution models, potentially affecting the skill of centennial scale climate change projections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22522383-radial-flow-pattern-slow-coronal-mass-ejection','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22522383-radial-flow-pattern-slow-coronal-mass-ejection"><span>RADIAL FLOW PATTERN OF A SLOW CORONAL <span class="hlt">MASS</span> EJECTION</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Feng, Li; Gan, Weiqun, E-mail: lfeng@pmo.ac.cn; Inhester, Bernd</p> <p>2015-06-01</p> <p>Height–time plots of the leading edge of coronal <span class="hlt">mass</span> ejections (CMEs) have often been used to study CME kinematics. We propose a new method to analyze the CME kinematics in more detail by determining the radial <span class="hlt">mass</span> transport process throughout the entire CME. Thus, our method is able to estimate not only the speed of the CME front but also the radial flow speed inside the CME. We have applied this method to a slow CME with an average leading edge speed of about 480 km s{sup −1}. In the <span class="hlt">Lagrangian</span> frame, the speeds of the individual CME <span class="hlt">mass</span> elementsmore » stay almost constant within 2 and 15 R{sub S}, the range over which we analyzed the CME. Hence, we have no evidence of net radial forces acting on parts of the CME in this range or of a pile up of <span class="hlt">mass</span> ahead of the CME. We find evidence that the leading edge trajectory obtained by tie-pointing may gradually lag behind the <span class="hlt">Lagrangian</span> front-side trajectories derived from our analysis. Our results also allow a much more precise estimate of the CME energy. Compared with conventional estimates using the CME total <span class="hlt">mass</span> and leading edge motion, we find that the latter may overestimate the kinetic energy and the gravitational potential energy.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26871161','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26871161"><span>Structure of sheared and rotating turbulence: Multiscale statistics of <span class="hlt">Lagrangian</span> and Eulerian accelerations and passive scalar dynamics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jacobitz, Frank G; Schneider, Kai; Bos, Wouter J T; Farge, Marie</p> <p>2016-01-01</p> <p>The acceleration statistics of sheared and rotating homogeneous turbulence are studied using direct numerical simulation results. The statistical properties of <span class="hlt">Lagrangian</span> and Eulerian accelerations are considered together with the influence of the rotation to shear ratio, as well as the scale dependence of their statistics. The probability density functions (pdfs) of both <span class="hlt">Lagrangian</span> and Eulerian accelerations show a strong and similar dependence on the rotation to shear ratio. The variance and flatness of both accelerations are analyzed and the extreme values of the Eulerian acceleration are observed to be above those of the <span class="hlt">Lagrangian</span> acceleration. For strong rotation it is observed that flatness yields values close to three, corresponding to Gaussian-like behavior, and for moderate and vanishing rotation the flatness increases. Furthermore, the <span class="hlt">Lagrangian</span> and Eulerian accelerations are shown to be strongly correlated for strong rotation due to a reduced nonlinear term in this case. A wavelet-based scale-dependent analysis shows that the flatness of both Eulerian and <span class="hlt">Lagrangian</span> accelerations increases as scale decreases, which provides evidence for intermittent behavior. For strong rotation the Eulerian acceleration is even more intermittent than the <span class="hlt">Lagrangian</span> acceleration, while the opposite result is obtained for moderate rotation. Moreover, the dynamics of a passive scalar with gradient production in the direction of the mean velocity gradient is analyzed and the influence of the rotation to shear ratio is studied. Concerning the concentration of a passive scalar spread by the flow, the pdf of its Eulerian time rate of change presents higher extreme values than those of its <span class="hlt">Lagrangian</span> time rate of change. This suggests that the Eulerian time rate of change of scalar concentration is mainly due to advection, while its <span class="hlt">Lagrangian</span> counterpart is only due to gradient production and viscous dissipation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1919137F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1919137F"><span>Evaluation of the HF-Radar network system around Taiwan using normalized cumulative <span class="hlt">Lagrangian</span> separation.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fredj, Erick; Kohut, Josh; Roarty, Hugh; Lai, Jian-Wu</p> <p>2017-04-01</p> <p>The <span class="hlt">Lagrangian</span> separation distance between the endpoints of simulated and observed drifter trajectories is often used to assess the performance of numerical particle trajectory models. However, the separation distance fails to indicate relative model performance in weak and strong current regions, such as over continental shelves and the adjacent deep ocean. A skill score described in detail by (Lui et.al. 2011) was applied to estimate the cumulative <span class="hlt">Lagrangian</span> separation distances normalized by the associated cumulative trajectory lengths. In contrast, the <span class="hlt">Lagrangian</span> separation distance alone gives a misleading result. The proposed dimensionless skill score is particularly useful when the number of drifter trajectories is limited and neither a conventional Eulerian-based velocity nor a <span class="hlt">Lagrangian</span> based probability density function may be estimated. The skill score assesses The Taiwan Ocean Radar Observing System (TOROS) performance. TOROS consists of 17 SeaSonde type radars around the Taiwan Island. The currents off Taiwan are significantly influenced by the nearby Kuroshio current. The main stream of the Kuroshio flows along the east coast of Taiwan to the north throughout the year. Sometimes its branch current also bypasses the south end of Taiwan and goes north along the west coast of Taiwan. The Kuroshio is also prone to seasonal change in its speed of flow, current capacity, distribution width, and depth. The evaluations of HF-Radar National Taiwanese network performance using <span class="hlt">Lagrangian</span> drifter records demonstrated the high quality and robustness of TOROS HF-Radar data using a purely trajectory-based non-dimensional index. Yonggang Liu and Robert H. Weisberg, "Evaluation of trajectory modeling in different dynamic regions using normalized cumulative <span class="hlt">Lagrangian</span> separation", Journal of Geophysical Research, Vol. 116, C09013, doi:10.1029/2010JC006837, 2011</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70013978','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70013978"><span>Eulerian-<span class="hlt">Lagrangian</span> solution of the convection-dispersion equation in natural coordinates</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cheng, Ralph T.; Casulli, Vincenzo; Milford, S. Nevil</p> <p>1984-01-01</p> <p>The vast majority of numerical investigations of transport phenomena use an Eulerian formulation for the convenience that the computational grids are fixed in space. An Eulerian-<span class="hlt">Lagrangian</span> method (ELM) of solution for the convection-dispersion equation is discussed and analyzed. The ELM uses the <span class="hlt">Lagrangian</span> concept in an Eulerian computational grid system. The values of the dependent variable off the grid are calculated by interpolation. When a linear interpolation is used, the method is a slight improvement over the upwind difference method. At this level of approximation both the ELM and the upwind difference method suffer from large numerical dispersion. However, if second-order <span class="hlt">Lagrangian</span> polynomials are used in the interpolation, the ELM is proven to be free of artificial numerical dispersion for the convection-dispersion equation. The concept of the ELM is extended for treatment of anisotropic dispersion in natural coordinates. In this approach the anisotropic properties of dispersion can be conveniently related to the properties of the flow field. Several numerical examples are given to further substantiate the results of the present analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22525003-general-form-coupled-horndeski-lagrangian-allows-cosmological-scaling-solutions','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22525003-general-form-coupled-horndeski-lagrangian-allows-cosmological-scaling-solutions"><span>The general form of the coupled Horndeski <span class="hlt">Lagrangian</span> that allows cosmological scaling solutions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gomes, Adalto R.; Amendola, Luca, E-mail: argomes.ufma@gmail.com, E-mail: l.amendola@thphys.uni-heidelberg.de</p> <p></p> <p>We consider the general scalar field Horndeski <span class="hlt">Lagrangian</span> coupled to dark matter. Within this class of models, we present two results that are independent of the particular form of the model. First, we show that in a Friedmann-Robertson-Walker metric the Horndeski <span class="hlt">Lagrangian</span> coincides with the pressure of the scalar field. Second, we employ the previous result to identify the most general form of the <span class="hlt">Lagrangian</span> that allows for cosmological scaling solutions, i.e. solutions where the ratio of dark matter to field density and the equation of state remain constant. Scaling solutions of this kind may help solving the coincidence problemmore » since in this case the presently observed ratio of matter to dark energy does not depend on initial conditions, but rather on the theoretical parameters.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DFD.B1003B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DFD.B1003B"><span>Stanley Corrsin Award Lecture: <span class="hlt">Lagrangian</span> Measurements in Turbulence: From Fundamentals to Applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bodenschatz, Eberhard</p> <p>2014-11-01</p> <p>In my talk I shall present results from particle tracking experiments in turbulence. After a short review of the history of the field, I shall summarize the most recent technological advances that range form low and high-density particle tracking to direct measurements of the <span class="hlt">Lagrangian</span> evolution of vorticity. I shall embark on a journey that describes the discoveries made possible by this new technology in the last 15 years. I present results that challenge our understanding of turbulence and show how <span class="hlt">Lagrangian</span> particle tracking can help us ask questions on turbulent flows that so far were hidden. I shall show how <span class="hlt">Lagrangian</span> particle tracking may provide important insights into the reversibility of turbulent flows, on vorticity generation, the energy cascade and turbulent mixing. I shall describe the consequences of inertial particle transport on rain formation and end with an outlook on how <span class="hlt">Lagrangian</span> particle tracking experiments on non-stationary flows in real-world situations may provide high quality data that can support real world engineering problems. I am very thankful for the support by Cornell University, the National Science Foundation, the Research Corporation, the Alfred P. Sloan Foundation, the Kavli Institute for Theoretical Physics, the German Research Foundation, the European Union and the Max Planck Society. I very gratefully acknowledge the excellent partnership with many colleagues in the field of fluid mechanics and turbulence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....4424S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....4424S"><span>Source-receptor matrix calculation with a <span class="hlt">Lagrangian</span> particle dispersion model in backward mode</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seibert, P.; Frank, A.</p> <p>2003-04-01</p> <p>A method for the calculation of source-receptor (s-r) relationships (sensitivity of a trace substance concentration at some place and time to emission at some place and time) with <span class="hlt">Lagrangian</span> particle models has been derived and presented previously (Air Pollution Modeling and its Application XIV, Proc. of ITM Boulder 2000). Now, the generalisation to any linear s-r relationship, including dry and wet deposition, decay etc., is presented. It was implemented in the model FLEXPART and tested extensively in idealised set-ups. These tests turned out to be very useful for finding minor model bugs and inaccuracies, and can be recommended generally for model testing. Recently, a convection scheme has been integrated in FLEXPART which was also tested. Both source and receptor can be specified in <span class="hlt">mass</span> mixing ratio or <span class="hlt">mass</span> units. Properly taking care of this is quite relevant for sources and receptors at different levels in the atmosphere. Furthermore, we present a test with the transport of aerosol-bound Caesium-137 from the areas contaminated by the Chernobyl disaster to Stockholm during one month.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1324262-second-order-upwind-lagrangian-particle-method-euler-equations','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1324262-second-order-upwind-lagrangian-particle-method-euler-equations"><span>Second order upwind <span class="hlt">Lagrangian</span> particle method for Euler equations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Samulyak, Roman; Chen, Hsin -Chiang; Yu, Kwangmin</p> <p>2016-06-01</p> <p>A new second order upwind <span class="hlt">Lagrangian</span> particle method for solving Euler equations for compressible inviscid fluid or gas flows is proposed. Similar to smoothed particle hydrodynamics (SPH), the method represents fluid cells with <span class="hlt">Lagrangian</span> particles and is suitable for the simulation of complex free surface / multiphase flows. The main contributions of our method, which is different from SPH in all other aspects, are (a) significant improvement of approximation of differential operators based on a polynomial fit via weighted least squares approximation and the convergence of prescribed order, (b) an upwind second-order particle-based algorithm with limiter, providing accuracy and longmore » term stability, and (c) accurate resolution of states at free interfaces. In conclusion, numerical verification tests demonstrating the convergence order for fixed domain and free surface problems are presented.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1324262','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1324262"><span>Second order upwind <span class="hlt">Lagrangian</span> particle method for Euler equations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Samulyak, Roman; Chen, Hsin -Chiang; Yu, Kwangmin</p> <p></p> <p>A new second order upwind <span class="hlt">Lagrangian</span> particle method for solving Euler equations for compressible inviscid fluid or gas flows is proposed. Similar to smoothed particle hydrodynamics (SPH), the method represents fluid cells with <span class="hlt">Lagrangian</span> particles and is suitable for the simulation of complex free surface / multiphase flows. The main contributions of our method, which is different from SPH in all other aspects, are (a) significant improvement of approximation of differential operators based on a polynomial fit via weighted least squares approximation and the convergence of prescribed order, (b) an upwind second-order particle-based algorithm with limiter, providing accuracy and longmore » term stability, and (c) accurate resolution of states at free interfaces. In conclusion, numerical verification tests demonstrating the convergence order for fixed domain and free surface problems are presented.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940010374','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940010374"><span>A new <span class="hlt">Lagrangian</span> method for three-dimensional steady supersonic flows</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Loh, Ching-Yuen; Liou, Meng-Sing</p> <p>1993-01-01</p> <p>In this report, the new <span class="hlt">Lagrangian</span> method introduced by Loh and Hui is extended for three-dimensional, steady supersonic flow computation. The derivation of the conservation form and the solution of the local Riemann solver using the Godunov and the high-resolution TVD (total variation diminished) scheme is presented. This new approach is accurate and robust, capable of handling complicated geometry and interactions between discontinuous waves. Test problems show that the extended <span class="hlt">Lagrangian</span> method retains all the advantages of the two-dimensional method (e.g., crisp resolution of a slip-surface (contact discontinuity) and automatic grid generation). In this report, we also suggest a novel three dimensional Riemann problem in which interesting and intricate flow features are present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21502629-effective-lagrangian-nonlinear-electrodynamics-its-properties-causality-unitarity','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21502629-effective-lagrangian-nonlinear-electrodynamics-its-properties-causality-unitarity"><span>Effective <span class="hlt">Lagrangian</span> in nonlinear electrodynamics and its properties of causality and unitarity</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Shabad, Anatoly E.; Usov, Vladimir V.</p> <p>2011-05-15</p> <p>In nonlinear electrodynamics, by implementing the causality principle as the requirement that the group velocity of elementary excitations over a background field should not exceed the speed of light in the vacuum c=1, and the unitarity principle as the requirement that the residue of the propagator should be nonnegative, we establish the positive convexity of the effective <span class="hlt">Lagrangian</span> on the class of constant fields, also the positivity of all characteristic dielectric and magnetic permittivity constants that are derivatives of the effective <span class="hlt">Lagrangian</span> with respect to the field invariants. Violation of the general principles by the one-loop approximation in QED atmore » exponentially large magnetic field is analyzed, resulting in complex energy ghosts that signal the instability of the magnetized vacuum. Superluminal excitations (tachyons) appear, too, but for the magnetic field exceeding its instability threshold. Also other popular <span class="hlt">Lagrangians</span> are tested to establish that the ones leading to spontaneous vacuum magnetization possess wrong convexity.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28961072','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28961072"><span>A Satellite-Based <span class="hlt">Lagrangian</span> View on Phytoplankton Dynamics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lehahn, Yoav; d'Ovidio, Francesco; Koren, Ilan</p> <p>2018-01-03</p> <p>The well-lit upper layer of the open ocean is a dynamical environment that hosts approximately half of global primary production. In the remote parts of this environment, distant from the coast and from the seabed, there is no obvious spatially fixed reference frame for describing the dynamics of the microscopic drifting organisms responsible for this immense production of organic matter-the phytoplankton. Thus, a natural perspective for studying phytoplankton dynamics is to follow the trajectories of water parcels in which the organisms are embedded. With the advent of satellite oceanography, this <span class="hlt">Lagrangian</span> perspective has provided valuable information on different aspects of phytoplankton dynamics, including bloom initiation and termination, spatial distribution patterns, biodiversity, export of carbon to the deep ocean, and, more recently, bottom-up mechanisms that affect the distribution and behavior of higher-trophic-level organisms. Upcoming submesoscale-resolving satellite observations and swarms of autonomous platforms open the way to the integration of vertical dynamics into the <span class="hlt">Lagrangian</span> view of phytoplankton dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26353373','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26353373"><span>Multiphase Interface Tracking with Fast Semi-<span class="hlt">Lagrangian</span> Contouring.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Xiaosheng; He, Xiaowei; Liu, Xuehui; Zhang, Jian J; Liu, Baoquan; Wu, Enhua</p> <p>2016-08-01</p> <p>We propose a semi-<span class="hlt">Lagrangian</span> method for multiphase interface tracking. In contrast to previous methods, our method maintains an explicit polygonal mesh, which is reconstructed from an unsigned distance function and an indicator function, to track the interface of arbitrary number of phases. The surface mesh is reconstructed at each step using an efficient multiphase polygonization procedure with precomputed stencils while the distance and indicator function are updated with an accurate semi-<span class="hlt">Lagrangian</span> path tracing from the meshes of the last step. Furthermore, we provide an adaptive data structure, multiphase distance tree, to accelerate the updating of both the distance function and the indicator function. In addition, the adaptive structure also enables us to contour the distance tree accurately with simple bisection techniques. The major advantage of our method is that it can easily handle topological changes without ambiguities and preserve both the sharp features and the volume well. We will evaluate its efficiency, accuracy and robustness in the results part with several examples.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..SHK.H5003N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..SHK.H5003N"><span>Next Generation Extended <span class="hlt">Lagrangian</span> Quantum-based Molecular Dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Negre, Christian</p> <p>2017-06-01</p> <p>A new framework for extended <span class="hlt">Lagrangian</span> first-principles molecular dynamics simulations is presented, which overcomes shortcomings of regular, direct Born-Oppenheimer molecular dynamics, while maintaining important advantages of the unified extended <span class="hlt">Lagrangian</span> formulation of density functional theory pioneered by Car and Parrinello three decades ago. The new framework allows, for the first time, energy conserving, linear-scaling Born-Oppenheimer molecular dynamics simulations, which is necessary to study larger and more realistic systems over longer simulation times than previously possible. Expensive, self-consinstent-field optimizations are avoided and normal integration time steps of regular, direct Born-Oppenheimer molecular dynamics can be used. Linear scaling electronic structure theory is presented using a graph-based approach that is ideal for parallel calculations on hybrid computer platforms. For the first time, quantum based Born-Oppenheimer molecular dynamics simulation is becoming a practically feasible approach in simulations of +100,000 atoms-representing a competitive alternative to classical polarizable force field methods. In collaboration with: Anders Niklasson, Los Alamos National Laboratory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JPhA...42U5207C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JPhA...42U5207C"><span>Unambiguous formalism for higher order <span class="hlt">Lagrangian</span> field theories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Campos, Cédric M.; de León, Manuel; Martín de Diego, David; Vankerschaver, Joris</p> <p>2009-11-01</p> <p>The aim of this paper is to propose an unambiguous intrinsic formalism for higher order field theories which avoids the arbitrariness in the generalization of the conventional description of field theories, and implies the existence of different Cartan forms and Legendre transformations. We propose a differential-geometric setting for the dynamics of a higher order field theory, based on the Skinner and Rusk formalism for mechanics. This approach incorporates aspects of both the <span class="hlt">Lagrangian</span> and the Hamiltonian description, since the field equations are formulated using the <span class="hlt">Lagrangian</span> on a higher order jet bundle and the canonical multisymplectic form on its affine dual. As both of these objects are uniquely defined, the Skinner-Rusk approach has the advantage that it does not suffer from the arbitrariness in conventional descriptions. The result is that we obtain a unique and global intrinsic version of the Euler-Lagrange equations for higher order field theories. Several examples illustrate our construction.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ARMS...10...99L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ARMS...10...99L"><span>A Satellite-Based <span class="hlt">Lagrangian</span> View on Phytoplankton Dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lehahn, Yoav; d'Ovidio, Francesco; Koren, Ilan</p> <p>2018-01-01</p> <p>The well-lit upper layer of the open ocean is a dynamical environment that hosts approximately half of global primary production. In the remote parts of this environment, distant from the coast and from the seabed, there is no obvious spatially fixed reference frame for describing the dynamics of the microscopic drifting organisms responsible for this immense production of organic matter—the phytoplankton. Thus, a natural perspective for studying phytoplankton dynamics is to follow the trajectories of water parcels in which the organisms are embedded. With the advent of satellite oceanography, this <span class="hlt">Lagrangian</span> perspective has provided valuable information on different aspects of phytoplankton dynamics, including bloom initiation and termination, spatial distribution patterns, biodiversity, export of carbon to the deep ocean, and, more recently, bottom-up mechanisms that affect the distribution and behavior of higher-trophic-level organisms. Upcoming submesoscale-resolving satellite observations and swarms of autonomous platforms open the way to the integration of vertical dynamics into the <span class="hlt">Lagrangian</span> view of phytoplankton dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSIS53A..06F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSIS53A..06F"><span>Collaborative Visual Seafloor Imaging using a Photographic AUV and a <span class="hlt">Lagrangian</span> Imaging Float</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Friedman, A.; Pizarro, O.; Roman, C.; Toohey, L.; Snyder, W.; Johnson-Roberson, M.; Iscar, E.; Williams, S. B.</p> <p>2016-02-01</p> <p>High resolution seafloor imaging from mobile autonomous platforms has become a valuable tool for habitat classification, stock assessment and seafloor exploration. This abstract addresses the concept of joint seafloor survey planning using both navigable and drifting platforms, and presents results from an experiment using a bottom surveying AUV and a drifting <span class="hlt">Lagrangian</span> camera float. We consider two classes of vehicles; one which is able to self propel and execute structured surveys, and one which is <span class="hlt">Lagrangian</span> and moves only with the currents. The navigable vehicle is the more capable and the more expensives asset of the two. The <span class="hlt">Lagrangian</span> platforms is a low cost imaging tool that can actively control its altitude above the seafloor to obtain high quality images but can not otherwise control its trajectory over the bottom. When used together the vehicles offer several scenarios for joint operations. When used in an exploratory manner the <span class="hlt">Lagrangian</span> float is an inexpensive way to collect images from an unknown area. Depending on the collected images, a follow on structured survey with the navigable AUV can collect additional information if the cost is acceptable given the need and prior data. When used simultaneously the drifting float can guide the AUV trajectory over an area. When both platforms are equipped with acoustic tracking and communications the AUV trajectory can be automatically redirected to follow the <span class="hlt">Lagrangian</span> float using one of many patterns. This capability allows for surveys that are potentially more representative of the near bottom oceanographic conditions at the desired location. Results will be presented from a cruise to Scott Reef, Australia, where both platforms were used as part of a coral habitat monitoring project.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27135811','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27135811"><span><span class="hlt">Lagrangian</span> Hotspots of In-Use NOX Emissions from Transit Buses.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kotz, Andrew J; Kittelson, David B; Northrop, William F</p> <p>2016-06-07</p> <p>In-use, spatiotemporal NOX emissions were measured from a conventional powertrain transit bus and a series electric hybrid bus over gradients of route kinetic intensity and ambient temperature. This paper introduces a new method for identifying NOX emissions hotspots along a bus route using high fidelity <span class="hlt">Lagrangian</span> vehicle data to explore spatial interactions that may influence emissions production. Our study shows that the studied transit buses emit higher than regulated emissions because on-route operation does not accurately represent the range of engine operation tested according to regulatory standards. Using the <span class="hlt">Lagrangian</span> hotspot detection, we demonstrate that NOX hotspots occurred at bus stops, during cold starts, on inclines, and for accelerations. On the selected routes, bus stops resulted in 3.3 times the route averaged emissions factor in grams/km without significant dependence on bus type or climate. The buses also emitted 2.3 times the route averaged NOX emissions factor at the beginning of each route due to cold selective catalytic reduction aftertreatment temperature. The <span class="hlt">Lagrangian</span> hotspot detection technique demonstrated here could be employed in future connected vehicles empowered by advances in computational power, data storage capability, and improved sensor technology to optimize emissions as a function of spatial location.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1912050R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1912050R"><span>Dry intrusions: <span class="hlt">Lagrangian</span> climatology and impact on the boundary layer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Raveh-Rubin, Shira; Wernli, Heini</p> <p>2017-04-01</p> <p>Dry air intrusions (DIs) are large-scale descending airstreams. A DI is typically referred to as a coherent airstream in the cold sector of an extratropical cyclone. Emerging evidence suggests that DIs are linked to severe surface wind gusts. However, there is yet no strict <span class="hlt">Lagrangian</span> definition of DIs, and so their climatological frequency, dynamical characteristics as well as their seasonal and spatial distributions are unknown. Furthermore, the dynamical interaction between DIs and the planetary boundary layer is not fully understood. Here, we suggest a <span class="hlt">Lagrangian</span> definition for DI air parcels, namely a minimum pressure increase along a trajectory of 400 hPa in 48 hours. Based on this criterion, the open questions are addressed by: (i) a novel global <span class="hlt">Lagrangian</span> climatology for the ECMWF ERA-Interim reanalysis dataset for the years 1979-2014; (ii) a case study illustrating the interaction between DIs and the boundary layer. We find that DIs occur predominantly in winter. DIs coherently descend from the upper troposphere (their stratospheric origin is small), to the mid- and low levels, where they mix with their environment and diverge. Different physical characteristics typify DIs in the different regions and seasons. Finally, we demonstrate the different mechanisms by which DIs can destabilize the boundary layer and facilitate the formation of strong surface winds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRC..122.5445S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122.5445S"><span>Impact of data assimilation on Eulerian versus <span class="hlt">Lagrangian</span> estimates of upper ocean transport</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sperrevik, Ann Kristin; Röhrs, Johannes; Christensen, Kai Hâkon</p> <p>2017-07-01</p> <p>Using four-dimensional variational analysis, we produce an estimate of the state of a coastal region in Northern Norway during the late winter and spring in 1984. We use satellite sea surface temperature and in situ observations from a series of intensive field campaigns, and obtain a more realistic distribution of water <span class="hlt">masses</span> both in the horizontal and the vertical than a pure downscaling approach can achieve. Although the distribution of Eulerian surface current speeds are similar, we find that they are more variable and less dependent on model bathymetry in our reanalysis compared to a hindcast produced using the same modeling system. <span class="hlt">Lagrangian</span> drift currents on the other hand are significantly changed, with overall higher kinetic energy levels in the reanalysis than in the hindcast, particularly in the superinertial frequency band.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28726683','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28726683"><span>Canonical-ensemble extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics for the linear scaling density functional theory.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hirakawa, Teruo; Suzuki, Teppei; Bowler, David R; Miyazaki, Tsuyoshi</p> <p>2017-10-11</p> <p>We discuss the development and implementation of a constant temperature (NVT) molecular dynamics scheme that combines the Nosé-Hoover chain thermostat with the extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics (BOMD) scheme, using a linear scaling density functional theory (DFT) approach. An integration scheme for this canonical-ensemble extended <span class="hlt">Lagrangian</span> BOMD is developed and discussed in the context of the Liouville operator formulation. Linear scaling DFT canonical-ensemble extended <span class="hlt">Lagrangian</span> BOMD simulations are tested on bulk silicon and silicon carbide systems to evaluate our integration scheme. The results show that the conserved quantity remains stable with no systematic drift even in the presence of the thermostat.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70013595','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70013595"><span>The Mohnian-Luisian boundary in the Coccolithus miopelagicus <span class="hlt">subzone</span>, with new and related species of forminifers.</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Arnal, R.E.</p> <p>1984-01-01</p> <p>New information obtained from samples colleced in a 1979 cruise is presented for the Luisian-Mohnian (Miocene) boundary. In some areas of the S California Borderland, the early Mohnian-Luisian boundary apparently occurs within the Coccolithus miopelagicus <span class="hlt">subzone</span>. To suppor this statement, the location of the samples and a list of the diagnostic foraminifers are provided for each sample in part I of this report. Fifteen species and one variety of new or undescribed benthic foraminifers which were observed in the course of this and other studies of the foraminiferal content of Dart core samples from the S California Borderland are reported and described in part II. The genus Bolivina is represented by 3 new species and 1 species previously undescribed. There are also 2 new species each of Uvigerina, Siphogenerina, Cassidulina, and Ehrenbergina; one undescribed species and a new variety of Megastomella; and one new species each of Epistominella and Concavella. -from Author</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002IJMPA..17..405H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002IJMPA..17..405H"><span>Hamiltonian vs <span class="hlt">Lagrangian</span> Embedding of a Massive Spin-One Theory Involving Two-Form Field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harikumar, E.; Sivakumar, M.</p> <p></p> <p>We consider the Hamiltonian and <span class="hlt">Lagrangian</span> embedding of a first-order, massive spin-one, gauge noninvariant theory involving antisymmetric tensor field. We apply the BFV-BRST generalized canonical approach to convert the model to a first class system and construct nilpotent BFV-BRST charge and a unitarizing Hamiltonian. The canonical analysis of the Stückelberg formulation of this model is presented. We bring out the contrasting feature in the constraint structure, specifically with respect to the reducibility aspect, of the Hamiltonian and the <span class="hlt">Lagrangian</span> embedded model. We show that to obtain manifestly covariant Stückelberg <span class="hlt">Lagrangian</span> from the BFV embedded Hamiltonian, phase space has to be further enlarged and show how the reducible gauge structure emerges in the embedded model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.H31E1213D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.H31E1213D"><span>Upscaling anomalous reactive kinetics (A+B-->C) from pore scale <span class="hlt">Lagrangian</span> velocity analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>De Anna, P.; Tartakovsky, A. M.; Le Borgne, T.; Dentz, M.</p> <p>2011-12-01</p> <p>Natural flow fields in porous media display a complex spatio-temporal organization due to heterogeneous geological structures at different scales. This multiscale disorder implies anomalous dispersion, mixing and reaction kinetics (Berkowitz et al. RG 2006, Tartakovsky PRE 2010). Here, we focus on the upscaling of anomalous kinetics arising from pore scale, non Gaussian and correlated, velocity distributions. We consider reactive front simulations, where a component A displaces a component B that saturates initially the porous domain. The reactive component C is produced at the dispersive front located at interface between the A and B domains. The simulations are performed with the SPH method. As the mixing zone grows, the total <span class="hlt">mass</span> of C produced increases with time. The scaling of this evolution with time is different from that which would be obtained from the homogeneous advection dispersion reaction equation. This anomalous kinetics property is related to spatial structure of the reactive mixture, and its evolution with time under the combined action of advective and diffusive processes. We discuss the different scaling regimes arising depending on the dominant process that governs mixing. In order to upscale these processes, we analyze the <span class="hlt">Lagrangian</span> velocity properties, which are characterized by the non Gaussian distributions and long range temporal correlation. The main origin of these properties is the existence of very low velocity regions where solute particles can remain trapped for a long time. Another source of strong correlation is the channeling of flow in localized high velocity regions, which created finger-like structures in the concentration field. We show the spatial Markovian, and temporal non Markovian, nature of the <span class="hlt">Lagrangian</span> velocity field. Therefore, an upscaled model can be defined as a correlated Continuous Time Random Walk (Le Borgne et al. PRL 2008). A key feature of this model is the definition of a transition probability density for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1439449-lagrangian-particle-method-compressible-fluid-dynamics','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1439449-lagrangian-particle-method-compressible-fluid-dynamics"><span><span class="hlt">Lagrangian</span> particle method for compressible fluid dynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Samulyak, Roman; Wang, Xingyu; Chen, Hsin -Chiang</p> <p></p> <p>A new <span class="hlt">Lagrangian</span> particle method for solving Euler equations for compressible inviscid fluid or gas flows is proposed. Similar to smoothed particle hydrodynamics (SPH), the method represents fluid cells with <span class="hlt">Lagrangian</span> particles and is suitable for the simulation of complex free surface / multi-phase flows. The main contributions of our method, which is different from SPH in all other aspects, are (a) significant improvement of approximation of differential operators based on a polynomial fit via weighted least squares approximation and the convergence of prescribed order, (b) a second-order particle-based algorithm that reduces to the first-order upwind method at local extremalmore » points, providing accuracy and long term stability, and (c) more accurate resolution of entropy discontinuities and states at free inter-faces. While the method is consistent and convergent to a prescribed order, the conservation of momentum and energy is not exact and depends on the convergence order . The method is generalizable to coupled hyperbolic-elliptic systems. As a result, numerical verification tests demonstrating the convergence order are presented as well as examples of complex multiphase flows.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28950601','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28950601"><span><span class="hlt">Lagrangian</span> descriptors of driven chemical reaction manifolds.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Craven, Galen T; Junginger, Andrej; Hernandez, Rigoberto</p> <p>2017-08-01</p> <p>The persistence of a transition state structure in systems driven by time-dependent environments allows the application of modern reaction rate theories to solution-phase and nonequilibrium chemical reactions. However, identifying this structure is problematic in driven systems and has been limited by theories built on series expansion about a saddle point. Recently, it has been shown that to obtain formally exact rates for reactions in thermal environments, a transition state trajectory must be constructed. Here, using optimized <span class="hlt">Lagrangian</span> descriptors [G. T. Craven and R. Hernandez, Phys. Rev. Lett. 115, 148301 (2015)PRLTAO0031-900710.1103/PhysRevLett.115.148301], we obtain this so-called distinguished trajectory and the associated moving reaction manifolds on model energy surfaces subject to various driving and dissipative conditions. In particular, we demonstrate that this is exact for harmonic barriers in one dimension and this verification gives impetus to the application of <span class="hlt">Lagrangian</span> descriptor-based methods in diverse classes of chemical reactions. The development of these objects is paramount in the theory of reaction dynamics as the transition state structure and its underlying network of manifolds directly dictate reactivity and selectivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950014634','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950014634"><span>A <span class="hlt">Lagrangian</span> dynamic subgrid-scale model turbulence</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Meneveau, C.; Lund, T. S.; Cabot, W.</p> <p>1994-01-01</p> <p>A new formulation of the dynamic subgrid-scale model is tested in which the error associated with the Germano identity is minimized over flow pathlines rather than over directions of statistical homogeneity. This procedure allows the application of the dynamic model with averaging to flows in complex geometries that do not possess homogeneous directions. The characteristic <span class="hlt">Lagrangian</span> time scale over which the averaging is performed is chosen such that the model is purely dissipative, guaranteeing numerical stability when coupled with the Smagorinsky model. The formulation is tested successfully in forced and decaying isotropic turbulence and in fully developed and transitional channel flow. In homogeneous flows, the results are similar to those of the volume-averaged dynamic model, while in channel flow, the predictions are superior to those of the plane-averaged dynamic model. The relationship between the averaged terms in the model and vortical structures (worms) that appear in the LES is investigated. Computational overhead is kept small (about 10 percent above the CPU requirements of the volume or plane-averaged dynamic model) by using an approximate scheme to advance the <span class="hlt">Lagrangian</span> tracking through first-order Euler time integration and linear interpolation in space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1439449-lagrangian-particle-method-compressible-fluid-dynamics','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1439449-lagrangian-particle-method-compressible-fluid-dynamics"><span><span class="hlt">Lagrangian</span> particle method for compressible fluid dynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Samulyak, Roman; Wang, Xingyu; Chen, Hsin -Chiang</p> <p>2018-02-09</p> <p>A new <span class="hlt">Lagrangian</span> particle method for solving Euler equations for compressible inviscid fluid or gas flows is proposed. Similar to smoothed particle hydrodynamics (SPH), the method represents fluid cells with <span class="hlt">Lagrangian</span> particles and is suitable for the simulation of complex free surface / multi-phase flows. The main contributions of our method, which is different from SPH in all other aspects, are (a) significant improvement of approximation of differential operators based on a polynomial fit via weighted least squares approximation and the convergence of prescribed order, (b) a second-order particle-based algorithm that reduces to the first-order upwind method at local extremalmore » points, providing accuracy and long term stability, and (c) more accurate resolution of entropy discontinuities and states at free inter-faces. While the method is consistent and convergent to a prescribed order, the conservation of momentum and energy is not exact and depends on the convergence order . The method is generalizable to coupled hyperbolic-elliptic systems. As a result, numerical verification tests demonstrating the convergence order are presented as well as examples of complex multiphase flows.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OcMod..97...27F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OcMod..97...27F"><span>A LES-based Eulerian-<span class="hlt">Lagrangian</span> approach to predict the dynamics of bubble plumes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fraga, Bruño; Stoesser, Thorsten; Lai, Chris C. K.; Socolofsky, Scott A.</p> <p>2016-01-01</p> <p>An approach for Eulerian-<span class="hlt">Lagrangian</span> large-eddy simulation of bubble plume dynamics is presented and its performance evaluated. The main numerical novelties consist in defining the gas-liquid coupling based on the bubble size to mesh resolution ratio (Dp/Δx) and the interpolation between Eulerian and <span class="hlt">Lagrangian</span> frameworks through the use of delta functions. The model's performance is thoroughly validated for a bubble plume in a cubic tank in initially quiescent water using experimental data obtained from high-resolution ADV and PIV measurements. The predicted time-averaged velocities and second-order statistics show good agreement with the measurements, including the reproduction of the anisotropic nature of the plume's turbulence. Further, the predicted Eulerian and <span class="hlt">Lagrangian</span> velocity fields, second-order turbulence statistics and interfacial gas-liquid forces are quantified and discussed as well as the visualization of the time-averaged primary and secondary flow structure in the tank.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Lagrangian&id=EJ185838','ERIC'); return false;" href="https://eric.ed.gov/?q=Lagrangian&id=EJ185838"><span>Construction of <span class="hlt">Lagrangians</span> and Hamiltonians from the Equation of Motion</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Yan, C. C.</p> <p>1978-01-01</p> <p>Demonstrates that infinitely many <span class="hlt">Lagrangians</span> and Hamiltonians can be constructed from a given equation of motion. Points out the lack of an established criterion for making a proper selection. (Author/GA)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS41B..06L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS41B..06L"><span>A Skill Score of Trajectory Model Evaluation Using Reinitialized Series of Normalized Cumulative <span class="hlt">Lagrangian</span> Separation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Y.; Weisberg, R. H.</p> <p>2017-12-01</p> <p>The <span class="hlt">Lagrangian</span> separation distance between the endpoints of simulated and observed drifter trajectories is often used to assess the performance of numerical particle trajectory models. However, the separation distance fails to indicate relative model performance in weak and strong current regions, such as a continental shelf and its adjacent deep ocean. A skill score is proposed based on the cumulative <span class="hlt">Lagrangian</span> separation distances normalized by the associated cumulative trajectory lengths. The new metrics correctly indicates the relative performance of the Global HYCOM in simulating the strong currents of the Gulf of Mexico Loop Current and the weaker currents of the West Florida Shelf in the eastern Gulf of Mexico. In contrast, the <span class="hlt">Lagrangian</span> separation distance alone gives a misleading result. Also, the observed drifter position series can be used to reinitialize the trajectory model and evaluate its performance along the observed trajectory, not just at the drifter end position. The proposed dimensionless skill score is particularly useful when the number of drifter trajectories is limited and neither a conventional Eulerian-based velocity nor a <span class="hlt">Lagrangian</span>-based probability density function may be estimated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26578642','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26578642"><span>Segmental Analysis of Cardiac Short-Axis Views Using <span class="hlt">Lagrangian</span> Radial and Circumferential Strain.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ma, Chi; Wang, Xiao; Varghese, Tomy</p> <p>2016-11-01</p> <p>Accurate description of myocardial deformation in the left ventricle is a three-dimensional problem, requiring three normal strain components along its natural axis, that is, longitudinal, radial, and circumferential strains. Although longitudinal strains are best estimated from long-axis views, radial and circumferential strains are best depicted in short-axis views. An algorithm that utilizes a polar grid for short-axis views previously developed in our laboratory for a <span class="hlt">Lagrangian</span> description of tissue deformation is utilized for radial and circumferential displacement and strain estimation. Deformation of the myocardial wall, utilizing numerical simulations with ANSYS, and a finite-element analysis-based canine heart model were adapted as the input to a frequency-domain ultrasound simulation program to generate radiofrequency echo signals. Clinical in vivo data were also acquired from a healthy volunteer. Local displacements estimated along and perpendicular to the ultrasound beam propagation direction are then transformed into radial and circumferential displacements and strains using the polar grid based on a pre-determined centroid location. <span class="hlt">Lagrangian</span> strain variations demonstrate good agreement with the ideal strain when compared with Eulerian results. <span class="hlt">Lagrangian</span> radial and circumferential strain estimation results are also demonstrated for experimental data on a healthy volunteer. <span class="hlt">Lagrangian</span> radial and circumferential strain tracking provide accurate results with the assistance of the polar grid, as demonstrated using both numerical simulations and in vivo study. © The Author(s) 2015.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4868801','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4868801"><span>Segmental Analysis of Cardiac Short-Axis Views Using <span class="hlt">Lagrangian</span> Radial and Circumferential Strain</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ma, Chi; Wang, Xiao; Varghese, Tomy</p> <p>2016-01-01</p> <p>Accurate description of myocardial deformation in the left ventricle is a three-dimensional problem, requiring three normal strain components along its natural axis, that is, longitudinal, radial, and circumferential strains. Although longitudinal strains are best estimated from long-axis views, radial and circumferential strains are best depicted in short-axis views. An algorithm that utilizes a polar grid for short-axis views previously developed in our laboratory for a <span class="hlt">Lagrangian</span> description of tissue deformation is utilized for radial and circumferential displacement and strain estimation. Deformation of the myocardial wall, utilizing numerical simulations with ANSYS, and a finite-element analysis–based canine heart model were adapted as the input to a frequency-domain ultrasound simulation program to generate radiofrequency echo signals. Clinical in vivo data were also acquired from a healthy volunteer. Local displacements estimated along and perpendicular to the ultrasound beam propagation direction are then transformed into radial and circumferential displacements and strains using the polar grid based on a pre-determined centroid location. <span class="hlt">Lagrangian</span> strain variations demonstrate good agreement with the ideal strain when compared with Eulerian results. <span class="hlt">Lagrangian</span> radial and circumferential strain estimation results are also demonstrated for experimental data on a healthy volunteer. <span class="hlt">Lagrangian</span> radial and circumferential strain tracking provide accurate results with the assistance of the polar grid, as demonstrated using both numerical simulations and in vivo study. PMID:26578642</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70185380','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70185380"><span>A <span class="hlt">Lagrangian</span> stochastic model for aerial spray transport above an oak forest</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wang, Yansen; Miller, David R.; Anderson, Dean E.; McManus, Michael L.</p> <p>1995-01-01</p> <p>An aerial spray droplets' transport model has been developed by applying recent advances in <span class="hlt">Lagrangian</span> stochastic simulation of heavy particles. A two-dimensional <span class="hlt">Lagrangian</span> stochastic model was adopted to simulate the spray droplet dispersion in atmospheric turbulence by adjusting the <span class="hlt">Lagrangian</span> integral time scale along the drop trajectory. The other major physical processes affecting the transport of spray droplets above a forest canopy, the aircraft wingtip vortices and the droplet evaporation, were also included in each time step of the droplets' transport.The model was evaluated using data from an aerial spray field experiment. In generally neutral stability conditions, the accuracy of the model predictions varied from run-to-run as expected. The average root-mean-square error was 24.61 IU cm−2, and the average relative error was 15%. The model prediction was adequate in two-dimensional steady wind conditions, but was less accurate in variable wind condition. The results indicated that the model can simulate successfully the ensemble; average transport of aerial spray droplets under neutral, steady atmospheric wind conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016TCry...10.1513R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016TCry...10.1513R"><span>Arctic sea-ice diffusion from observed and simulated <span class="hlt">Lagrangian</span> trajectories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rampal, Pierre; Bouillon, Sylvain; Bergh, Jon; Ólason, Einar</p> <p>2016-07-01</p> <p>We characterize sea-ice drift by applying a <span class="hlt">Lagrangian</span> diffusion analysis to buoy trajectories from the International Arctic Buoy Programme (IABP) dataset and from two different models: the standalone <span class="hlt">Lagrangian</span> sea-ice model neXtSIM and the Eulerian coupled ice-ocean model used for the TOPAZ reanalysis. By applying the diffusion analysis to the IABP buoy trajectories over the period 1979-2011, we confirm that sea-ice diffusion follows two distinct regimes (ballistic and Brownian) and we provide accurate values for the diffusivity and integral timescale that could be used in Eulerian or <span class="hlt">Lagrangian</span> passive tracers models to simulate the transport and diffusion of particles moving with the ice. We discuss how these values are linked to the evolution of the fluctuating displacements variance and how this information could be used to define the size of the search area around the position predicted by the mean drift. By comparing observed and simulated sea-ice trajectories for three consecutive winter seasons (2007-2011), we show how the characteristics of the simulated motion may differ from or agree well with observations. This comparison illustrates the usefulness of first applying a diffusion analysis to evaluate the output of modeling systems that include a sea-ice model before using these in, e.g., oil spill trajectory models or, more generally, to simulate the transport of passive tracers in sea ice.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhyA..465..472Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhyA..465..472Y"><span>A kinematic wave model in <span class="hlt">Lagrangian</span> coordinates incorporating capacity drop: Application to homogeneous road stretches and discontinuities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yuan, Kai; Knoop, Victor L.; Hoogendoorn, Serge P.</p> <p>2017-01-01</p> <p>On freeways, congestion always leads to capacity drop. This means the queue discharge rate is lower than the pre-queue capacity. Our recent research findings indicate that the queue discharge rate increases with the speed in congestion, that is the capacity drop is strongly correlated with the congestion state. Incorporating this varying capacity drop into a kinematic wave model is essential for assessing consequences of control strategies. However, to the best of authors' knowledge, no such a model exists. This paper fills the research gap by presenting a <span class="hlt">Lagrangian</span> kinematic wave model. "<span class="hlt">Lagrangian</span>" denotes that the new model is solved in <span class="hlt">Lagrangian</span> coordinates. The new model can give capacity drops accompanying both of stop-and-go waves (on homogeneous freeway section) and standing queues (at nodes) in a network. The new model can be applied in a network operation. In this <span class="hlt">Lagrangian</span> kinematic wave model, the queue discharge rate (or the capacity drop) is a function of vehicular speed in traffic jams. Four case studies on links as well as at lane-drop and on-ramp nodes show that the <span class="hlt">Lagrangian</span> kinematic wave model can give capacity drops well, consistent with empirical observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhFl...21f5101K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhFl...21f5101K"><span><span class="hlt">Lagrangian</span> particles with mixing. I. Simulating scalar transport</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klimenko, A. Y.</p> <p>2009-06-01</p> <p>The physical similarity and mathematical equivalence of continuous diffusion and particle random walk forms one of the cornerstones of modern physics and the theory of stochastic processes. The randomly walking particles do not need to posses any properties other than location in physical space. However, particles used in many models dealing with simulating turbulent transport and turbulent combustion do posses a set of scalar properties and mixing between particle properties is performed to reflect the dissipative nature of the diffusion processes. We show that the continuous scalar transport and diffusion can be accurately specified by means of localized mixing between randomly walking <span class="hlt">Lagrangian</span> particles with scalar properties and assess errors associated with this scheme. Particles with scalar properties and localized mixing represent an alternative formulation for the process, which is selected to represent the continuous diffusion. Simulating diffusion by <span class="hlt">Lagrangian</span> particles with mixing involves three main competing requirements: minimizing stochastic uncertainty, minimizing bias introduced by numerical diffusion, and preserving independence of particles. These requirements are analyzed for two limited cases of mixing between two particles and mixing between a large number of particles. The problem of possible dependences between particles is most complicated. This problem is analyzed using a coupled chain of equations that has similarities with Bogolubov-Born-Green-Kirkwood-Yvon chain in statistical physics. Dependences between particles can be significant in close proximity of the particles resulting in a reduced rate of mixing. This work develops further ideas introduced in the previously published letter [Phys. Fluids 19, 031702 (2007)]. Paper I of this work is followed by Paper II [Phys. Fluids 19, 065102 (2009)] where modeling of turbulent reacting flows by <span class="hlt">Lagrangian</span> particles with localized mixing is specifically considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OcMod..85...56B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OcMod..85...56B"><span><span class="hlt">Lagrangian</span> water <span class="hlt">mass</span> tracing from pseudo-Argo, model-derived salinity, tracer and velocity data: An application to Antarctic Intermediate Water in the South Atlantic Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blanke, Bruno; Speich, Sabrina; Rusciano, Emanuela</p> <p>2015-01-01</p> <p>We use the tracer and velocity fields of a climatological ocean model to investigate the ability of Argo-like data to estimate accurately water <span class="hlt">mass</span> movements and transformations, in the style of analyses commonly applied to the output of ocean general circulation model. To this end, we introduce an algorithm for the reconstruction of a fully non-divergent three-dimensional velocity field from the simple knowledge of the model vertical density profiles and 1000-m horizontal velocity components. The validation of the technique consists in comparing the resulting pathways for Antarctic Intermediate Water in the South Atlantic Ocean to equivalent reference results based on the full model information available for velocity and tracers. We show that the inclusion of a wind-induced Ekman pumping and of a well-thought-out expression for vertical velocity at the level of the intermediate waters is essential for the reliable reproduction of quantitative <span class="hlt">Lagrangian</span> analyses. Neglecting the seasonal variability of the velocity and tracer fields is not a significant source of errors, at least well below the permanent thermocline. These results give us confidence in the success of the adaptation of the algorithm to true gridded Argo data for investigating the dynamics of flows in the ocean interior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018CoTPh..69..233E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018CoTPh..69..233E"><span>Gravitational Field as a Pressure Force from Logarithmic <span class="hlt">Lagrangians</span> and Non-Standard Hamiltonians: The Case of Stellar Halo of Milky Way</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>El-Nabulsi, Rami Ahmad</p> <p>2018-03-01</p> <p>Recently, the notion of non-standard <span class="hlt">Lagrangians</span> was discussed widely in literature in an attempt to explore the inverse variational problem of nonlinear differential equations. Different forms of non-standard <span class="hlt">Lagrangians</span> were introduced in literature and have revealed nice mathematical and physical properties. One interesting form related to the inverse variational problem is the logarithmic <span class="hlt">Lagrangian</span>, which has a number of motivating features related to the Liénard-type and Emden nonlinear differential equations. Such types of <span class="hlt">Lagrangians</span> lead to nonlinear dynamics based on non-standard Hamiltonians. In this communication, we show that some new dynamical properties are obtained in stellar dynamics if standard <span class="hlt">Lagrangians</span> are replaced by Logarithmic <span class="hlt">Lagrangians</span> and their corresponding non-standard Hamiltonians. One interesting consequence concerns the emergence of an extra pressure term, which is related to the gravitational field suggesting that gravitation may act as a pressure in a strong gravitational field. The case of the stellar halo of the Milky Way is considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780037977&hterms=averaged+lagrangian&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Daveraged%2Blagrangian','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780037977&hterms=averaged+lagrangian&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Daveraged%2Blagrangian"><span>Microscopic <span class="hlt">Lagrangian</span> description of warm plasmas. I - Linear wave propagation. II - Nonlinear wave interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kim, H.; Crawford, F. W.</p> <p>1977-01-01</p> <p>It is pointed out that the conventional iterative analysis of nonlinear plasma wave phenomena, which involves a direct use of Maxwell's equations and the equations describing the particle dynamics, leads to formidable theoretical and algebraic complexities, especially for warm plasmas. As an effective alternative, the <span class="hlt">Lagrangian</span> method may be applied. It is shown how this method may be used in the microscopic description of small-signal wave propagation and in the study of nonlinear wave interactions. The linear theory is developed for an infinite, homogeneous, collisionless, warm magnetoplasma. A summary is presented of a perturbation expansion scheme described by Galloway and Kim (1971), and <span class="hlt">Lagrangians</span> to third order in perturbation are considered. Attention is given to the averaged-<span class="hlt">Lagrangian</span> density, the action-transfer and coupled-mode equations, and the general solution of the coupled-mode equations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/15013474','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/15013474"><span>Arbitrary <span class="hlt">Lagrangian</span>-Eulerian Method with Local Structured Adaptive Mesh Refinement for Modeling Shock Hydrodynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Anderson, R W; Pember, R B; Elliott, N S</p> <p>2001-10-22</p> <p>A new method that combines staggered grid Arbitrary <span class="hlt">Lagrangian</span>-Eulerian (ALE) techniques with structured local adaptive mesh refinement (AMR) has been developed for solution of the Euler equations. This method facilitates the solution of problems currently at and beyond the boundary of soluble problems by traditional ALE methods by focusing computational resources where they are required through dynamic adaption. Many of the core issues involved in the development of the combined ALEAMR method hinge upon the integration of AMR with a staggered grid <span class="hlt">Lagrangian</span> integration method. The novel components of the method are mainly driven by the need to reconcile traditionalmore » AMR techniques, which are typically employed on stationary meshes with cell-centered quantities, with the staggered grids and grid motion employed by <span class="hlt">Lagrangian</span> methods. Numerical examples are presented which demonstrate the accuracy and efficiency of the method.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010021412&hterms=averaged+lagrangian&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Daveraged%2Blagrangian','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010021412&hterms=averaged+lagrangian&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Daveraged%2Blagrangian"><span>Numerical Simulations of Homogeneous Turbulence Using <span class="hlt">Lagrangian</span>-Averaged Navier-Stokes Equations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mohseni, Kamran; Shkoller, Steve; Kosovic, Branko; Marsden, Jerrold E.; Carati, Daniele; Wray, Alan; Rogallo, Robert</p> <p>2000-01-01</p> <p>The <span class="hlt">Lagrangian</span>-averaged Navier-Stokes (LANS) equations are numerically evaluated as a turbulence closure. They are derived from a novel <span class="hlt">Lagrangian</span> averaging procedure on the space of all volume-preserving maps and can be viewed as a numerical algorithm which removes the energy content from the small scales (smaller than some a priori fixed spatial scale alpha) using a dispersive rather than dissipative mechanism, thus maintaining the crucial features of the large scale flow. We examine the modeling capabilities of the LANS equations for decaying homogeneous turbulence, ascertain their ability to track the energy spectrum of fully resolved direct numerical simulations (DNS), compare the relative energy decay rates, and compare LANS with well-accepted large eddy simulation (LES) models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996IJMPA..11.1353B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996IJMPA..11.1353B"><span>On the Perturbative Equivalence Between the Hamiltonian and <span class="hlt">Lagrangian</span> Quantizations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Batalin, I. A.; Tyutin, I. V.</p> <p></p> <p>The Hamiltonian (BFV) and <span class="hlt">Lagrangian</span> (BV) quantization schemes are proved to be perturbatively equivalent to each other. It is shown in particular that the quantum master equation being treated perturbatively possesses a local formal solution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28085305','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28085305"><span><span class="hlt">Lagrangian</span> statistics of mesoscale turbulence in a natural environment: The Agulhas return current.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Carbone, Francesco; Gencarelli, Christian N; Hedgecock, Ian M</p> <p>2016-12-01</p> <p>The properties of mesoscale geophysical turbulence in an oceanic environment have been investigated through the <span class="hlt">Lagrangian</span> statistics of sea surface temperature measured by a drifting buoy within the Agulhas return current, where strong temperature mixing produces locally sharp temperature gradients. By disentangling the large-scale forcing which affects the small-scale statistics, we found that the statistical properties of intermittency are identical to those obtained from the multifractal prediction in the <span class="hlt">Lagrangian</span> frame for the velocity trajectory. The results suggest a possible universality of turbulence scaling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DFDA34001M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DFDA34001M"><span>Analysis of <span class="hlt">Lagrangian</span> stretching in turbulent channel flow using a database task-parallel particle tracking approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meneveau, Charles; Johnson, Perry; Hamilton, Stephen; Burns, Randal</p> <p>2016-11-01</p> <p>An intrinsic property of turbulent flows is the exponential deformation of fluid elements along <span class="hlt">Lagrangian</span> paths. The production of enstrophy by vorticity stretching follows from a similar mechanism in the <span class="hlt">Lagrangian</span> view, though the alignment statistics differ and viscosity prevents unbounded growth. In this paper, the stretching properties of fluid elements and vorticity along <span class="hlt">Lagrangian</span> paths are studied in a channel flow at Reτ = 1000 and compared with prior, known results from isotropic turbulence. To track <span class="hlt">Lagrangian</span> paths in a public database containing Direct Numerical Simulation (DNS) results, the task-parallel approach previously employed in the isotropic database is extended to the case of flow in a bounded domain. It is shown that above 100 viscous units from the wall, stretching statistics are equal to their isotropic values, in support of the local isotropy hypothesis. Normalized by dissipation rate, the stretching in the buffer layer and below is less efficient due to less favorable alignment statistics. The Cramér function characterizing cumulative <span class="hlt">Lagrangian</span> stretching statistics shows that overall the channel flow has about half of the stretching per unit dissipation compared with isotropic turbulence. Supported by a National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-1232825, and by National Science Foundation Grants CBET-1507469, ACI-1261715, OCI-1244820 and by JHU IDIES.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994sai..reptR....H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994sai..reptR....H"><span>Fluid Dynamics <span class="hlt">Lagrangian</span> Simulation Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hyman, Ellis</p> <p>1994-02-01</p> <p>The work performed by Science Applications International Corporation (SAIC) on this contract, Fluid Dynamics <span class="hlt">Lagrangian</span> Simulation Model, Contract Number N00014-89-C-2106, SAIC Project Number 01-0157-03-0768, focused on a number of research topics in fluid dynamics. The work was in support of the programs of NRL's Laboratory for Computational Physics and Fluid Dynamics and covered the period from 10 September 1989 to 9 December 1993. In the following sections, we describe each of the efforts and the results obtained. Much of the research work has resulted in journal publications. These are included in Appendices of this report for which the reader is referred for complete details.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26524392','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26524392"><span>Uncovering the Geometry of Barrierless Reactions Using <span class="hlt">Lagrangian</span> Descriptors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Junginger, Andrej; Hernandez, Rigoberto</p> <p>2016-03-03</p> <p>Transition-state theories describing barrierless chemical reactions, or more general activated problems, are often hampered by the lack of a saddle around which the dividing surface can be constructed. For example, the time-dependent transition-state trajectory uncovering the nonrecrossing dividing surface in thermal reactions in the framework of the Langevin equation has relied on perturbative approaches in the vicinity of the saddle. We recently obtained an alternative approach using <span class="hlt">Lagrangian</span> descriptors to construct time-dependent and recrossing-free dividing surfaces. This is a nonperturbative approach making no reference to a putative saddle. Here we show how the <span class="hlt">Lagrangian</span> descriptor can be used to obtain the transition-state geometry of a dissipated and thermalized reaction across barrierless potentials. We illustrate the method in the case of a 1D Brownian motion for both barrierless and step potentials; however, the method is not restricted and can be directly applied to different kinds of potentials and higher dimensional systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29581453','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29581453"><span>Extracting quasi-steady <span class="hlt">Lagrangian</span> transport patterns from the ocean circulation: An application to the Gulf of Mexico.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Duran, R; Beron-Vera, F J; Olascoaga, M J</p> <p>2018-03-26</p> <p>We construct a climatology of <span class="hlt">Lagrangian</span> coherent structures (LCSs)-the concealed skeleton that shapes transport-with a twelve-year-long data-assimilative simulation of the sea-surface circulation in the Gulf of Mexico (GoM). Computed as time-mean Cauchy-Green strain tensorlines of the climatological velocity, the climatological LCSs (cLCSs) unveil recurrent <span class="hlt">Lagrangian</span> circulation patterns. The cLCSs strongly constrain the ensemble-mean <span class="hlt">Lagrangian</span> circulation of the instantaneous model velocity, showing that a climatological velocity can preserve meaningful transport information. The quasi-steady transport patterns revealed by the cLCSs agree well with aspects of the GoM circulation described in several previous observational and numerical studies. For example, the cLCSs identify regions of persistent isolation, and suggest that coastal regions previously identified as high-risk for pollution impact are regions of maximal attraction. We also show that cLCSs are remarkably accurate at identifying transport patterns observed during the Deepwater Horizon and Ixtoc oil spills, and during the Grand <span class="hlt">LAgrangian</span> Deployment (GLAD) experiment. Thus it is shown that computing cLCSs is an efficient and meaningful way of synthesizing vast amounts of <span class="hlt">Lagrangian</span> information. The cLCS method confirms previous GoM studies, and contributes to our understanding by revealing the persistent nature of the dynamics and kinematics treated therein.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017CMaPh.351..689B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017CMaPh.351..689B"><span>A Constructive Approach to Regularity of <span class="hlt">Lagrangian</span> Trajectories for Incompressible Euler Flow in a Bounded Domain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Besse, Nicolas; Frisch, Uriel</p> <p>2017-04-01</p> <p>The 3D incompressible Euler equations are an important research topic in the mathematical study of fluid dynamics. Not only is the global regularity for smooth initial data an open issue, but the behaviour may also depend on the presence or absence of boundaries. For a good understanding, it is crucial to carry out, besides mathematical studies, high-accuracy and well-resolved numerical exploration. Such studies can be very demanding in computational resources, but recently it has been shown that very substantial gains can be achieved first, by using Cauchy's <span class="hlt">Lagrangian</span> formulation of the Euler equations and second, by taking advantage of analyticity results of the <span class="hlt">Lagrangian</span> trajectories for flows whose initial vorticity is Hölder-continuous. The latter has been known for about 20 years (Serfati in J Math Pures Appl 74:95-104, 1995), but the combination of the two, which makes use of recursion relations among time-Taylor coefficients to obtain constructively the time-Taylor series of the <span class="hlt">Lagrangian</span> map, has been achieved only recently (Frisch and Zheligovsky in Commun Math Phys 326:499-505, 2014; Podvigina et al. in J Comput Phys 306:320-342, 2016 and references therein). Here we extend this methodology to incompressible Euler flow in an impermeable bounded domain whose boundary may be either analytic or have a regularity between indefinite differentiability and analyticity. Non-constructive regularity results for these cases have already been obtained by Glass et al. (Ann Sci Éc Norm Sup 45:1-51, 2012). Using the invariance of the boundary under the <span class="hlt">Lagrangian</span> flow, we establish novel recursion relations that include contributions from the boundary. This leads to a constructive proof of time-analyticity of the <span class="hlt">Lagrangian</span> trajectories with analytic boundaries, which can then be used subsequently for the design of a very high-order Cauchy-<span class="hlt">Lagrangian</span> method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA574569','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA574569"><span>A <span class="hlt">Lagrangian</span> Analysis of a Developing and Non-Developing Disturbance Observed During the PREDICT Experiment</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2012-12-03</p> <p>paper provides an introduction of <span class="hlt">Lagrangian</span> techniques for locating flow boundaries that encompass regions of recirculation in time- dependent flows...the low- to mid- level embryonic vortex from adverse conditions, while the 1The glossary on NOAA’s Hurricane Research Division’s web - site uses...wave or disturbance. This paper provides an introduction of <span class="hlt">Lagrangian</span> techniques for locating flow boundaries that encompass regions of recirculation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016WRR....52.8561Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016WRR....52.8561Z"><span>Bounded fractional diffusion in geological media: Definition and <span class="hlt">Lagrangian</span> approximation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Yong; Green, Christopher T.; LaBolle, Eric M.; Neupauer, Roseanna M.; Sun, HongGuang</p> <p>2016-11-01</p> <p>Spatiotemporal fractional-derivative models (FDMs) have been increasingly used to simulate non-Fickian diffusion, but methods have not been available to define boundary conditions for FDMs in bounded domains. This study defines boundary conditions and then develops a <span class="hlt">Lagrangian</span> solver to approximate bounded, one-dimensional fractional diffusion. Both the zero-value and nonzero-value Dirichlet, Neumann, and mixed Robin boundary conditions are defined, where the sign of Riemann-Liouville fractional derivative (capturing nonzero-value spatial-nonlocal boundary conditions with directional superdiffusion) remains consistent with the sign of the fractional-diffusive flux term in the FDMs. New <span class="hlt">Lagrangian</span> schemes are then proposed to track solute particles moving in bounded domains, where the solutions are checked against analytical or Eulerian solutions available for simplified FDMs. Numerical experiments show that the particle-tracking algorithm for non-Fickian diffusion differs from Fickian diffusion in relocating the particle position around the reflective boundary, likely due to the nonlocal and nonsymmetric fractional diffusion. For a nonzero-value Neumann or Robin boundary, a source cell with a reflective face can be applied to define the release rate of random-walking particles at the specified flux boundary. Mathematical definitions of physically meaningful nonlocal boundaries combined with bounded <span class="hlt">Lagrangian</span> solvers in this study may provide the only viable techniques at present to quantify the impact of boundaries on anomalous diffusion, expanding the applicability of FDMs from infinite domains to those with any size and boundary conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70177969','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70177969"><span>Bounded fractional diffusion in geological media: Definition and <span class="hlt">Lagrangian</span> approximation</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Zhang, Yong; Green, Christopher T.; LaBolle, Eric M.; Neupauer, Roseanna M.; Sun, HongGuang</p> <p>2016-01-01</p> <p>Spatiotemporal Fractional-Derivative Models (FDMs) have been increasingly used to simulate non-Fickian diffusion, but methods have not been available to define boundary conditions for FDMs in bounded domains. This study defines boundary conditions and then develops a <span class="hlt">Lagrangian</span> solver to approximate bounded, one-dimensional fractional diffusion. Both the zero-value and non-zero-value Dirichlet, Neumann, and mixed Robin boundary conditions are defined, where the sign of Riemann-Liouville fractional derivative (capturing non-zero-value spatial-nonlocal boundary conditions with directional super-diffusion) remains consistent with the sign of the fractional-diffusive flux term in the FDMs. New <span class="hlt">Lagrangian</span> schemes are then proposed to track solute particles moving in bounded domains, where the solutions are checked against analytical or Eularian solutions available for simplified FDMs. Numerical experiments show that the particle-tracking algorithm for non-Fickian diffusion differs from Fickian diffusion in relocating the particle position around the reflective boundary, likely due to the non-local and non-symmetric fractional diffusion. For a non-zero-value Neumann or Robin boundary, a source cell with a reflective face can be applied to define the release rate of random-walking particles at the specified flux boundary. Mathematical definitions of physically meaningful nonlocal boundaries combined with bounded <span class="hlt">Lagrangian</span> solvers in this study may provide the only viable techniques at present to quantify the impact of boundaries on anomalous diffusion, expanding the applicability of FDMs from infinite do mains to those with any size and boundary conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JCoPh.237..251S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JCoPh.237..251S"><span>A cell-centered <span class="hlt">Lagrangian</span> finite volume approach for computing elasto-plastic response of solids in cylindrical axisymmetric geometries</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sambasivan, Shiv Kumar; Shashkov, Mikhail J.; Burton, Donald E.</p> <p>2013-03-01</p> <p>A finite volume cell-centered <span class="hlt">Lagrangian</span> formulation is presented for solving large deformation problems in cylindrical axisymmetric geometries. Since solid materials can sustain significant shear deformation, evolution equations for stress and strain fields are solved in addition to <span class="hlt">mass</span>, momentum and energy conservation laws. The total strain-rate realized in the material is split into an elastic and plastic response. The elastic and plastic components in turn are modeled using hypo-elastic theory. In accordance with the hypo-elastic model, a predictor-corrector algorithm is employed for evolving the deviatoric component of the stress tensor. A trial elastic deviatoric stress state is obtained by integrating a rate equation, cast in the form of an objective (Jaumann) derivative, based on Hooke's law. The dilatational response of the material is modeled using an equation of state of the Mie-Grüneisen form. The plastic deformation is accounted for via an iterative radial return algorithm constructed from the J2 von Mises yield condition. Several benchmark example problems with non-linear strain hardening and thermal softening yield models are presented. Extensive comparisons with representative Eulerian and <span class="hlt">Lagrangian</span> hydrocodes in addition to analytical and experimental results are made to validate the current approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGP...127....1B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGP...127....1B"><span><span class="hlt">Lagrangian</span> submanifolds with constant angle functions of the nearly Kähler S3 ×S3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bektaş, Burcu; Moruz, Marilena; Van der Veken, Joeri; Vrancken, Luc</p> <p>2018-04-01</p> <p>We study <span class="hlt">Lagrangian</span> submanifolds of the nearly Kähler S3 ×S3 with respect to their so called angle functions. We show that if all angle functions are constant, then the submanifold is either totally geodesic or has constant sectional curvature and there is a classification theorem that follows from Dioos et al. (2018). Moreover, we show that if precisely one angle function is constant, then it must be equal to 0 , π/3 or 2π/3. Using then two remarkable constructions together with the classification of <span class="hlt">Lagrangian</span> submanifolds of which the first component has nowhere maximal rank from, Bektaş et al. (2018), we obtain a classification of such <span class="hlt">Lagrangian</span> submanifolds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1140523-preserving-lagrangian-structure-nonlinear-model-reduction-application-structural-dynamics','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1140523-preserving-lagrangian-structure-nonlinear-model-reduction-application-structural-dynamics"><span>Preserving <span class="hlt">Lagrangian</span> Structure in Nonlinear Model Reduction with Application to Structural Dynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Carlberg, Kevin; Tuminaro, Ray; Boggs, Paul</p> <p>2015-03-11</p> <p>Our work proposes a model-reduction methodology that preserves <span class="hlt">Lagrangian</span> structure and achieves computational efficiency in the presence of high-order nonlinearities and arbitrary parameter dependence. As such, the resulting reduced-order model retains key properties such as energy conservation and symplectic time-evolution maps. We focus on parameterized simple mechanical systems subjected to Rayleigh damping and external forces, and consider an application to nonlinear structural dynamics. To preserve structure, the method first approximates the system's “<span class="hlt">Lagrangian</span> ingredients''---the Riemannian metric, the potential-energy function, the dissipation function, and the external force---and subsequently derives reduced-order equations of motion by applying the (forced) Euler--Lagrange equation with thesemore » quantities. Moreover, from the algebraic perspective, key contributions include two efficient techniques for approximating parameterized reduced matrices while preserving symmetry and positive definiteness: matrix gappy proper orthogonal decomposition and reduced-basis sparsification. Our results for a parameterized truss-structure problem demonstrate the practical importance of preserving <span class="hlt">Lagrangian</span> structure and illustrate the proposed method's merits: it reduces computation time while maintaining high accuracy and stability, in contrast to existing nonlinear model-reduction techniques that do not preserve structure.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1140523','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1140523"><span>Preserving <span class="hlt">Lagrangian</span> Structure in Nonlinear Model Reduction with Application to Structural Dynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Carlberg, Kevin; Tuminaro, Ray; Boggs, Paul</p> <p></p> <p>Our work proposes a model-reduction methodology that preserves <span class="hlt">Lagrangian</span> structure and achieves computational efficiency in the presence of high-order nonlinearities and arbitrary parameter dependence. As such, the resulting reduced-order model retains key properties such as energy conservation and symplectic time-evolution maps. We focus on parameterized simple mechanical systems subjected to Rayleigh damping and external forces, and consider an application to nonlinear structural dynamics. To preserve structure, the method first approximates the system's “<span class="hlt">Lagrangian</span> ingredients''---the Riemannian metric, the potential-energy function, the dissipation function, and the external force---and subsequently derives reduced-order equations of motion by applying the (forced) Euler--Lagrange equation with thesemore » quantities. Moreover, from the algebraic perspective, key contributions include two efficient techniques for approximating parameterized reduced matrices while preserving symmetry and positive definiteness: matrix gappy proper orthogonal decomposition and reduced-basis sparsification. Our results for a parameterized truss-structure problem demonstrate the practical importance of preserving <span class="hlt">Lagrangian</span> structure and illustrate the proposed method's merits: it reduces computation time while maintaining high accuracy and stability, in contrast to existing nonlinear model-reduction techniques that do not preserve structure.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5455999-lagrangian-formulation-penny-shaped-perkins-kern-geometry-models','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5455999-lagrangian-formulation-penny-shaped-perkins-kern-geometry-models"><span><span class="hlt">Lagrangian</span> formulation for penny-shaped and Perkins-Kern geometry models</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lee, W.S.</p> <p>1989-09-01</p> <p>This paper discusses basic theories for vertical penny-shaped and Perkins-Kern (PK) geometry models developed with a <span class="hlt">Lagrangian</span> formulation combined with a virtual-work analysis. The <span class="hlt">Lagrangian</span> formulation yields a pair of nonlinear equations in R/sub f/ or L/sub f/ and b/sub f/, the fracture radius or length and half-width. By introduction of a virtual-work analysis, a simple equation is obtained that can be solved numerically. This equation is written in a form that can be used to determine fracture geometry when the fluid-loss coefficient of the fracturing fluid is known. Also, this equation, coupled with a material-balance equation after shut-in, canmore » be used to analyze pressure-decline data after shut-in to determine the effective fluid-loss coefficient and fracture geometry.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28989316','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28989316"><span>Stochastic partial differential fluid equations as a diffusive limit of deterministic <span class="hlt">Lagrangian</span> multi-time dynamics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cotter, C J; Gottwald, G A; Holm, D D</p> <p>2017-09-01</p> <p>In Holm (Holm 2015 Proc. R. Soc. A 471 , 20140963. (doi:10.1098/rspa.2014.0963)), stochastic fluid equations were derived by employing a variational principle with an assumed stochastic <span class="hlt">Lagrangian</span> particle dynamics. Here we show that the same stochastic <span class="hlt">Lagrangian</span> dynamics naturally arises in a multi-scale decomposition of the deterministic <span class="hlt">Lagrangian</span> flow map into a slow large-scale mean and a rapidly fluctuating small-scale map. We employ homogenization theory to derive effective slow stochastic particle dynamics for the resolved mean part, thereby obtaining stochastic fluid partial equations in the Eulerian formulation. To justify the application of rigorous homogenization theory, we assume mildly chaotic fast small-scale dynamics, as well as a centring condition. The latter requires that the mean of the fluctuating deviations is small, when pulled back to the mean flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015FoPh...45..661D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015FoPh...45..661D"><span>Nonconservative <span class="hlt">Lagrangian</span> Mechanics: Purely Causal Equations of Motion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dreisigmeyer, David W.; Young, Peter M.</p> <p>2015-06-01</p> <p>This work builds on the Volterra series formalism presented in Dreisigmeyer and Young (J Phys A 36: 8297, 2003) to model nonconservative systems. Here we treat <span class="hlt">Lagrangians</span> and actions as `time dependent' Volterra series. We present a new family of kernels to be used in these Volterra series that allow us to derive a single retarded equation of motion using a variational principle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014CPM.....1...85O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014CPM.....1...85O"><span><span class="hlt">Lagrangian</span> analysis of multiscale particulate flows with the particle finite element method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oñate, Eugenio; Celigueta, Miguel Angel; Latorre, Salvador; Casas, Guillermo; Rossi, Riccardo; Rojek, Jerzy</p> <p>2014-05-01</p> <p>We present a <span class="hlt">Lagrangian</span> numerical technique for the analysis of flows incorporating physical particles of different sizes. The numerical approach is based on the particle finite element method (PFEM) which blends concepts from particle-based techniques and the FEM. The basis of the <span class="hlt">Lagrangian</span> formulation for particulate flows and the procedure for modelling the motion of small and large particles that are submerged in the fluid are described in detail. The numerical technique for analysis of this type of multiscale particulate flows using a stabilized mixed velocity-pressure formulation and the PFEM is also presented. Examples of application of the PFEM to several particulate flows problems are given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26575769','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26575769"><span>Extended <span class="hlt">Lagrangian</span> Density Functional Tight-Binding Molecular Dynamics for Molecules and Solids.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aradi, Bálint; Niklasson, Anders M N; Frauenheim, Thomas</p> <p>2015-07-14</p> <p>A computationally fast quantum mechanical molecular dynamics scheme using an extended <span class="hlt">Lagrangian</span> density functional tight-binding formulation has been developed and implemented in the DFTB+ electronic structure program package for simulations of solids and molecular systems. The scheme combines the computational speed of self-consistent density functional tight-binding theory with the efficiency and long-term accuracy of extended <span class="hlt">Lagrangian</span> Born-Oppenheimer molecular dynamics. For systems without self-consistent charge instabilities, only a single diagonalization or construction of the single-particle density matrix is required in each time step. The molecular dynamics simulation scheme can be applied to a broad range of problems in materials science, chemistry, and biology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70020645','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70020645"><span>Solution of the advection-dispersion equation in two dimensions by a finite-volume Eulerian-<span class="hlt">Lagrangian</span> localized adjoint method</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Healy, R.W.; Russell, T.F.</p> <p>1998-01-01</p> <p>We extend the finite-volume Eulerian-<span class="hlt">Lagrangian</span> localized adjoint method (FVELLAM) for solution of the advection-dispersion equation to two dimensions. The method can conserve <span class="hlt">mass</span> globally and is not limited by restrictions on the size of the grid Peclet or Courant number. Therefore, it is well suited for solution of advection-dominated ground-water solute transport problems. In test problem comparisons with standard finite differences, FVELLAM is able to attain accurate solutions on much coarser space and time grids. On fine grids, the accuracy of the two methods is comparable. A critical aspect of FVELLAM (and all other ELLAMs) is evaluation of the <span class="hlt">mass</span> storage integral from the preceding time level. In FVELLAM this may be accomplished with either a forward or backtracking approach. The forward tracking approach conserves <span class="hlt">mass</span> globally and is the preferred approach. The backtracking approach is less computationally intensive, but not globally <span class="hlt">mass</span> conservative. Boundary terms are systematically represented as integrals in space and time which are evaluated by a common integration scheme in conjunction with forward tracking through time. Unlike the one-dimensional case, local <span class="hlt">mass</span> conservation cannot be guaranteed, so slight oscillations in concentration can develop, particularly in the vicinity of inflow or outflow boundaries. Published by Elsevier Science Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012IJTP...51.2015K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012IJTP...51.2015K"><span>Remarks on the "Non-canonicity Puzzle": <span class="hlt">Lagrangian</span> Symmetries of the Einstein-Hilbert Action</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kiriushcheva, N.; Komorowski, P. G.; Kuzmin, S. V.</p> <p>2012-07-01</p> <p>Given the non-canonical relationship between variables used in the Hamiltonian formulations of the Einstein-Hilbert action (due to Pirani, Schild, Skinner (PSS) and Dirac) and the Arnowitt-Deser-Misner (ADM) action, and the consequent difference in the gauge transformations generated by the first-class constraints of these two formulations, the assumption that the <span class="hlt">Lagrangians</span> from which they were derived are equivalent leads to an apparent contradiction that has been called "the non-canonicity puzzle". In this work we shall investigate the group properties of two symmetries derived for the Einstein-Hilbert action: diffeomorphism, which follows from the PSS and Dirac formulations, and the one that arises from the ADM formulation. We demonstrate that unlike the diffeomorphism transformations, the ADM transformations (as well as others, which can be constructed for the Einstein-Hilbert <span class="hlt">Lagrangian</span> using Noether's identities) do not form a group. This makes diffeomorphism transformations unique (the term "canonical" symmetry might be suggested). If the two <span class="hlt">Lagrangians</span> are to be called equivalent, canonical symmetry must be preserved. The interplay between general covariance and the canonicity of the variables used is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70016855','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70016855"><span>Solution of the advection-dispersion equation by a finite-volume eulerian-<span class="hlt">lagrangian</span> local adjoint method</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Healy, R.W.; Russell, T.F.</p> <p>1992-01-01</p> <p>A finite-volume Eulerian-<span class="hlt">Lagrangian</span> local adjoint method for solution of the advection-dispersion equation is developed and discussed. The method is <span class="hlt">mass</span> conservative and can solve advection-dominated ground-water solute-transport problems accurately and efficiently. An integrated finite-difference approach is used in the method. A key component of the method is that the integral representing the <span class="hlt">mass</span>-storage term is evaluated numerically at the current time level. Integration points, and the <span class="hlt">mass</span> associated with these points, are then forward tracked up to the next time level. The number of integration points required to reach a specified level of accuracy is problem dependent and increases as the sharpness of the simulated solute front increases. Integration points are generally equally spaced within each grid cell. For problems involving variable coefficients it has been found to be advantageous to include additional integration points at strategic locations in each well. These locations are determined by backtracking. Forward tracking of boundary fluxes by the method alleviates problems that are encountered in the backtracking approaches of most characteristic methods. A test problem is used to illustrate that the new method offers substantial advantages over other numerical methods for a wide range of problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960011642','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960011642"><span>Floating shock fitting via <span class="hlt">Lagrangian</span> adaptive meshes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vanrosendale, John</p> <p>1995-01-01</p> <p>In recent work we have formulated a new approach to compressible flow simulation, combining the advantages of shock-fitting and shock-capturing. Using a cell-centered on Roe scheme discretization on unstructured meshes, we warp the mesh while marching to steady state, so that mesh edges align with shocks and other discontinuities. This new algorithm, the Shock-fitting <span class="hlt">Lagrangian</span> Adaptive Method (SLAM), is, in effect, a reliable shock-capturing algorithm which yields shock-fitted accuracy at convergence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..SHK.H4002D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..SHK.H4002D"><span>Modeling and Numerical Challenges in Eulerian-<span class="hlt">Lagrangian</span> Computations of Shock-driven Multiphase Flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diggs, Angela; Balachandar, Sivaramakrishnan</p> <p>2015-06-01</p> <p>The present work addresses the numerical methods required for particle-gas and particle-particle interactions in Eulerian-<span class="hlt">Lagrangian</span> simulations of multiphase flow. Local volume fraction as seen by each particle is the quantity of foremost importance in modeling and evaluating such interactions. We consider a general multiphase flow with a distribution of particles inside a fluid flow discretized on an Eulerian grid. Particle volume fraction is needed both as a <span class="hlt">Lagrangian</span> quantity associated with each particle and also as an Eulerian quantity associated with the flow. In Eulerian Projection (EP) methods, the volume fraction is first obtained within each cell as an Eulerian quantity and then interpolated to each particle. In <span class="hlt">Lagrangian</span> Projection (LP) methods, the particle volume fraction is obtained at each particle and then projected onto the Eulerian grid. Traditionally, EP methods are used in multiphase flow, but sub-grid resolution can be obtained through use of LP methods. By evaluating the total error and its components we compare the performance of EP and LP methods. The standard von Neumann error analysis technique has been adapted for rigorous evaluation of rate of convergence. The methods presented can be extended to obtain accurate field representations of other <span class="hlt">Lagrangian</span> quantities. Most importantly, we will show that such careful attention to numerical methodologies is needed in order to capture complex shock interaction with a bed of particles. Supported by U.S. Department of Defense SMART Program and the U.S. Department of Energy PSAAP-II program under Contract No. DE-NA0002378.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24089943','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24089943"><span><span class="hlt">Lagrangian</span> coherent structures at the onset of hyperchaos in the two-dimensional Navier-Stokes equations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miranda, Rodrigo A; Rempel, Erico L; Chian, Abraham C-L; Seehafer, Norbert; Toledo, Benjamin A; Muñoz, Pablo R</p> <p>2013-09-01</p> <p>We study a transition to hyperchaos in the two-dimensional incompressible Navier-Stokes equations with periodic boundary conditions and an external forcing term. Bifurcation diagrams are constructed by varying the Reynolds number, and a transition to hyperchaos (HC) is identified. Before the onset of HC, there is coexistence of two chaotic attractors and a hyperchaotic saddle. After the transition to HC, the two chaotic attractors merge with the hyperchaotic saddle, generating random switching between chaos and hyperchaos, which is responsible for intermittent bursts in the time series of energy and enstrophy. The chaotic mixing properties of the flow are characterized by detecting <span class="hlt">Lagrangian</span> coherent structures. After the transition to HC, the flow displays complex <span class="hlt">Lagrangian</span> patterns and an increase in the level of <span class="hlt">Lagrangian</span> chaoticity during the bursty periods that can be predicted statistically by the hyperchaotic saddle prior to HC transition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5627383','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5627383"><span>Stochastic partial differential fluid equations as a diffusive limit of deterministic <span class="hlt">Lagrangian</span> multi-time dynamics</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cotter, C. J.</p> <p>2017-01-01</p> <p>In Holm (Holm 2015 Proc. R. Soc. A 471, 20140963. (doi:10.1098/rspa.2014.0963)), stochastic fluid equations were derived by employing a variational principle with an assumed stochastic <span class="hlt">Lagrangian</span> particle dynamics. Here we show that the same stochastic <span class="hlt">Lagrangian</span> dynamics naturally arises in a multi-scale decomposition of the deterministic <span class="hlt">Lagrangian</span> flow map into a slow large-scale mean and a rapidly fluctuating small-scale map. We employ homogenization theory to derive effective slow stochastic particle dynamics for the resolved mean part, thereby obtaining stochastic fluid partial equations in the Eulerian formulation. To justify the application of rigorous homogenization theory, we assume mildly chaotic fast small-scale dynamics, as well as a centring condition. The latter requires that the mean of the fluctuating deviations is small, when pulled back to the mean flow. PMID:28989316</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770023699','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770023699"><span>Development and application of a three dimensional numerical model for predicting pollutant and sediment transport using an Eulerian-<span class="hlt">Lagrangian</span> marker particle technique</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pavish, D. L.; Spaulding, M. L.</p> <p>1977-01-01</p> <p>A computer coded <span class="hlt">Lagrangian</span> marker particle in Eulerian finite difference cell solution to the three dimensional incompressible <span class="hlt">mass</span> transport equation, Water Advective Particle in Cell Technique, WAPIC, was developed, verified against analytic solutions, and subsequently applied in the prediction of long term transport of a suspended sediment cloud resulting from an instantaneous dredge spoil release. Numerical results from WAPIC were verified against analytic solutions to the three dimensional incompressible <span class="hlt">mass</span> transport equation for turbulent diffusion and advection of Gaussian dye releases in unbounded uniform and uniformly sheared uni-directional flow, and for steady-uniform plug channel flow. WAPIC was utilized to simulate an analytic solution for non-equilibrium sediment dropout from an initially vertically uniform particle distribution in one dimensional turbulent channel flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900019473','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900019473"><span>On the use of <span class="hlt">Lagrangian</span> variables in descriptions of unsteady boundary-layer separation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cowley, Stephen J.; Vandommelen, Leon L.; Lam, Shui T.</p> <p>1990-01-01</p> <p>The <span class="hlt">Lagrangian</span> description of unsteady boundary layer separation is reviewed from both analytical and numerical perspectives. It is explained in simple terms how particle distortion gives rise to unsteady separation, and why a theory centered on <span class="hlt">Lagrangian</span> coordinates provides the clearest description of this phenomenon. Some of the more recent results for unsteady three dimensional compressible separation are included. The different forms of separation that can arise from symmetries are emphasized. A possible description of separation is also included when the detaching vorticity layer exits the classical boundary layer region, but still remains much closer to the surface than a typical body-lengthscale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19..688R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19..688R"><span>Sensitivity Analysis of a <span class="hlt">Lagrangian</span> Sea Ice Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rabatel, Matthias; Rampal, Pierre; Bertino, Laurent; Carrassi, Alberto; Jones, Christopher K. R. T.</p> <p>2017-04-01</p> <p>Large changes in the Arctic sea ice have been observed in the last decades in terms of the ice thickness, extension and drift. Understanding the mechanisms behind these changes is of paramount importance to enhance our modeling and forecasting capabilities. For 40 years, models have been developed to describe the non-linear dynamical response of the sea ice to a number of external and internal factors. Nevertheless, there still exists large deviations between predictions and observations. There are related to incorrect descriptions of the sea ice response and/or to the uncertainties about the different sources of information: parameters, initial and boundary conditions and external forcing. Data assimilation (DA) methods are used to combine observations with models, and there is nowadays an increasing interest of DA for sea-ice models and observations. We consider here the state-of-the art sea-ice model, neXtSIM te{Rampal2016a}, which is based on a time-varying <span class="hlt">Lagrangian</span> mesh and makes use of the Elasto-Brittle rheology. Our ultimate goal is designing appropriate DA scheme for such a modelling facility. This contribution reports about the first milestone along this line: a sensitivity analysis in order to quantify forecast error to guide model development and to set basis for further <span class="hlt">Lagrangian</span> DA methods. Specific features of the sea-ice dynamics in relation to the wind are thus analysed. Virtual buoys are deployed across the Arctic domain and their trajectories of motion are analysed. The simulated trajectories are also compared to real buoys trajectories observed. The model response is also compared with that one from a model version not including internal forcing to highlight the role of the rheology. Conclusions and perspectives for the general DA implementation are also discussed. \\bibitem{Rampal2016a} P. Rampal, S. Bouillon, E. Ólason, and M. Morlighem. ne{X}t{SIM}: a new {<span class="hlt">L}agrangian</span> sea ice model. The Cryosphere, 10 (3): 1055-1073, 2016.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JHEP...04..110A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JHEP...04..110A"><span>Phenomenology of the Higgs effective <span class="hlt">Lagrangian</span> via F eynR ules</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alloul, Adam; Fuks, Benjamin; Sanz, Verónica</p> <p>2014-04-01</p> <p>The Higgs discovery and the lack of any other hint for new physics favor a description of non-standard Higgs physics in terms of an effective field theory. We present an implementation of a general Higgs effective <span class="hlt">Lagrangian</span> containing operators up to dimension six in the framework of F eynR ules and provide details on the translation between the <span class="hlt">mass</span> and interaction bases, in particular for three- and four-point interaction vertices involving Higgs and gauge bosons. We illustrate the strengths of this implementation by using the UFO interface of F eynR ules capable to generate model files that can be understood by the M adG raph 5 event generator and that have the specificity to contain all interaction vertices, without any restriction on the number of external legs or on the complexity of the Lorentz structures. We then investigate several new physics effects in total rates and differential distributions for different Higgs production modes, including gluon fusion, associated production with a gauge boson and di-Higgs production. We finally study contact interactions of gauge and Higgs bosons to fermions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008CNSNS..13.2071W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008CNSNS..13.2071W"><span>A deterministic <span class="hlt">Lagrangian</span> particle separation-based method for advective-diffusion problems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wong, Ken T. M.; Lee, Joseph H. W.; Choi, K. W.</p> <p>2008-12-01</p> <p>A simple and robust <span class="hlt">Lagrangian</span> particle scheme is proposed to solve the advective-diffusion transport problem. The scheme is based on relative diffusion concepts and simulates diffusion by regulating particle separation. This new approach generates a deterministic result and requires far less number of particles than the random walk method. For the advection process, particles are simply moved according to their velocity. The general scheme is <span class="hlt">mass</span> conservative and is free from numerical diffusion. It can be applied to a wide variety of advective-diffusion problems, but is particularly suited for ecological and water quality modelling when definition of particle attributes (e.g., cell status for modelling algal blooms or red tides) is a necessity. The basic derivation, numerical stability and practical implementation of the NEighborhood Separation Technique (NEST) are presented. The accuracy of the method is demonstrated through a series of test cases which embrace realistic features of coastal environmental transport problems. Two field application examples on the tidal flushing of a fish farm and the dynamics of vertically migrating marine algae are also presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=128805&keyword=Herrera&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=128805&keyword=Herrera&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>AN EULERIAN-<span class="hlt">LAGRANGIAN</span> LOCALIZED ADJOINT METHOD FOR THE ADVECTION-DIFFUSION EQUATION</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Many numerical methods use characteristic analysis to accommodate the advective component of transport. Such characteristic methods include Eulerian-<span class="hlt">Lagrangian</span> methods (ELM), modified method of characteristics (MMOC), and operator splitting methods. A generalization of characteri...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Ocgy...57..648B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Ocgy...57..648B"><span>Identification and <span class="hlt">Lagrangian</span> analysis of oceanographic structures favorable for fishery of neon flying squid ( Ommastrephes bartramii) in the South Kuril area</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Budyansky, M. V.; Prants, S. V.; Samko, E. V.; Uleysky, M. Yu.</p> <p>2017-09-01</p> <p>Based on the AVISO velocity field, we compute daily synoptic <span class="hlt">Lagrangian</span> maps in the South Kuril area for the fishery seasons of 1998, 1999, and 2001-2005 from available catching data on neon flying squid (NFS). With the help of drift maps for artificial particles, we found that the majority of NFS fishing grounds featuring maximum catches are situated near large-scale <span class="hlt">Lagrangian</span> intrusions: tongues of water penetrating the surrounding water of other <span class="hlt">Lagrangian</span> properties. It is shown that the NFS catch locations tend to accumulate at places where waters with different magnitudes of certain <span class="hlt">Lagrangian</span> indicators converge, mix, and produce filaments, swirls, and tendrils typical of chaotic advection. Potential NFS fishing grounds are mainly located near (1) <span class="hlt">Lagrangian</span> intrusions of the Subarctic front, (2) intrusions of Okhotsk Sea and Oyashio waters around mesoscale anticyclones east of Hokkaido with subsequent penetration of catch locations inside eddies and (3) intrusions of subtropical waters into the central part of the South Kuril area due to interaction with eddies of different size and polarity. Possible reasons for increased biological production and fishery in the vicinity of <span class="hlt">Lagrangian</span> intrusions are discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1770c0069K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1770c0069K"><span>Analytical solution of the problem of a shock wave in the collapsing gas in <span class="hlt">Lagrangian</span> coordinates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuropatenko, V. F.; Shestakovskaya, E. S.</p> <p>2016-10-01</p> <p>It is proposed the exact solution of the problem of a convergent shock wave and gas dynamic compression in a spherical vessel with an impermeable wall in <span class="hlt">Lagrangian</span> coordinates. At the initial time the speed of cold ideal gas is equal to zero, and a negative velocity is set on boundary of the sphere. When t > t0 the shock wave spreads from this point into the gas. The boundary of the sphere will move under the certain law correlated with the motion of the shock wave. The trajectories of the gas particles in <span class="hlt">Lagrangian</span> coordinates are straight lines. The equations determining the structure of the gas flow between the shock front and gas border have been found as a function of time and <span class="hlt">Lagrangian</span> coordinate. The dependence of the entropy on the velocity of the shock wave has been found too. For <span class="hlt">Lagrangian</span> coordinates the problem is first solved. It is fundamentally different from previously known formulations of the problem of the self-convergence of the self-similar shock wave to the center of symmetry and its reflection from the center, which was built up for the infinite area in Euler coordinates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ChPhC..41k4106H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ChPhC..41k4106H"><span>Dirac and Pauli form factors of nucleons using nonlocal chiral effective <span class="hlt">Lagrangian</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>He, Fangcheng; Wang, Ping</p> <p>2017-11-01</p> <p>Dirac and Pauli form factors are investigated in the relativistic chiral effective <span class="hlt">Lagrangian</span>. The octet and decuplet intermediate states are included in the one-loop calculation. The 4-dimensional regulator is introduced to deal with the divergence. Different from the non-relativistic case, this 4-dimensional regulator is generated from the nonlocal <span class="hlt">Lagrangian</span> with the gauge link, which guarantees local gauge invariance. As a result, additional diagrams appear which ensure electric charge 1 and 0 for proton and neutron respectively. The obtained Dirac and Pauli form factors of the nucleons are all reasonable up to relatively large Q 2. Supported by National Natural Science Foundation of China (11475186) and Sino-German CRC 110 (NSFC 11621131001)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1227099','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1227099"><span>Extended <span class="hlt">Lagrangian</span> Density Functional Tight-Binding Molecular Dynamics for Molecules and Solids</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Aradi, Bálint; Niklasson, Anders M. N.; Frauenheim, Thomas</p> <p></p> <p>A computationally fast quantum mechanical molecular dynamics scheme using an extended <span class="hlt">Lagrangian</span> density functional tight-binding formulation has been developed and implemented in the DFTB+ electronic structure program package for simulations of solids and molecular systems. The scheme combines the computational speed of self-consistent density functional tight-binding theory with the efficiency and long-term accuracy of extended <span class="hlt">Lagrangian</span> Born–Oppenheimer molecular dynamics. Furthermore, for systems without self-consistent charge instabilities, only a single diagonalization or construction of the single-particle density matrix is required in each time step. The molecular dynamics simulation scheme can also be applied to a broad range of problems in materialsmore » science, chemistry, and biology.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1227099-extended-lagrangian-density-functional-tight-binding-molecular-dynamics-molecules-solids','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1227099-extended-lagrangian-density-functional-tight-binding-molecular-dynamics-molecules-solids"><span>Extended <span class="hlt">Lagrangian</span> Density Functional Tight-Binding Molecular Dynamics for Molecules and Solids</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Aradi, Bálint; Niklasson, Anders M. N.; Frauenheim, Thomas</p> <p>2015-06-26</p> <p>A computationally fast quantum mechanical molecular dynamics scheme using an extended <span class="hlt">Lagrangian</span> density functional tight-binding formulation has been developed and implemented in the DFTB+ electronic structure program package for simulations of solids and molecular systems. The scheme combines the computational speed of self-consistent density functional tight-binding theory with the efficiency and long-term accuracy of extended <span class="hlt">Lagrangian</span> Born–Oppenheimer molecular dynamics. Furthermore, for systems without self-consistent charge instabilities, only a single diagonalization or construction of the single-particle density matrix is required in each time step. The molecular dynamics simulation scheme can also be applied to a broad range of problems in materialsmore » science, chemistry, and biology.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNG41A1782W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNG41A1782W"><span>Comparing High-latitude Ionospheric and Thermospheric <span class="hlt">Lagrangian</span> Coherent Structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, N.; Ramirez, U.; Flores, F.; Okic, D.; Datta-Barua, S.</p> <p>2015-12-01</p> <p><span class="hlt">Lagrangian</span> Coherent Structures (LCSs) are invisible boundaries in time varying flow fields that may be subject to mixing and turbulence. The LCS is defined by the local maxima of the finite time Lyapunov exponent (FTLE), a scalar field quantifying the degree of stretching of fluid elements over the flow domain. Although the thermosphere is dominated by neutral wind processes and the ionosphere is governed by plasma electrodynamics, we can compare the LCS in the two modeled flow fields to yield insight into transport and interaction processes in the high-latitude IT system. For obtaining thermospheric LCS, we use the Horizontal Wind Model 2014 (HWM14) [1] at a single altitude to generate the two-dimensional velocity field. The FTLE computation is applied to study the flow field of the neutral wind, and to visualize the forward-time <span class="hlt">Lagrangian</span> Coherent Structures in the flow domain. The time-varying structures indicate a possible thermospheric LCS ridge in the auroral oval area. The results of a two-day run during a geomagnetically quiet period show that the structures are diurnally quasi-periodic, thus that solar radiation influences the neutral wind flow field. To find the LCS in the high-latitude ionospheric drifts, the Weimer 2001 [2] polar electric potential model and the International Geomagnetic Reference Field 11 [3] are used to compute the ExB drift flow field in ionosphere. As with the neutral winds, the <span class="hlt">Lagrangian</span> Coherent Structures are obtained by applying the FTLE computation. The relationship between the thermospheric and ionospheric LCS is analyzed by comparing overlapping FTLE maps. Both a publicly available FTLE solver [4] and a custom-built FTLE computation are used and compared for validation [5]. Comparing the modeled IT LCSs on a quiet day with the modeled IT LCSs on a storm day indicates important factors on the structure and time evolution of the LCS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/214259','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/214259"><span>Archaeology in the Kilauea East Rift Zone: Part 1, Land-use model and research design, Kapoho, Kamaili and Kilauea Geothermal <span class="hlt">Subzones</span>, Puna District, Hawaii Island</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Burtchard, G.C.; Moblo, P.</p> <p>1994-07-01</p> <p>The Puna Geothermal Resource <span class="hlt">Subzones</span> (GRS) project area encompasses approximately 22,000 acres centered on the Kilauea East Rift Zone in Puna District, Hawaii Island. The area is divided into three <span class="hlt">subzones</span> proposed for geothermal power development -- Kilauea Middle East Rift, Kamaili and Kapoho GRS. Throughout the time of human occupation, eruptive episodes along the rift have maintained a dynamic landscape. Periodic volcanic events, for example, have changed the coastline configuration, altered patterns of agriculturally suitable sediments, and created an assortment of periodically active, periodically quiescent, volcanic hazards. Because of the active character of the rift zone, then, the area`smore » occupants have always been obliged to organize their use of the landscape to accommodate a dynamic mosaic of lava flow types and ages. While the specific configuration of settlements and agricultural areas necessarily changed in response to volcanic events, it is possible to anticipate general patterns in the manner in which populations used the landscape through time. This research design offers a model that predicts the spatial results of long-term land-use patterns and relates them to the character of the archaeological record of that use. In essence, the environmental/land-use model developed here predicts that highest population levels, and hence the greatest abundance and complexity of identifiable prehistoric remains, tended to cluster near the coast at places that maximized access to productive fisheries and agricultural soils. With the possible exception of a few inland settlements, the density of archaeological remains expected to decrease with distance from the coastline. The pattern is generally supported in the regions existing ethnohistoric and archaeological record.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25615123','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25615123"><span><span class="hlt">Lagrangian</span> approach to understanding the origin of the gill-kinematics switch in mayfly nymphs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chabreyrie, R; Balaras, E; Abdelaziz, K; Kiger, K</p> <p>2014-12-01</p> <p>The mayfly nymph breathes under water through an oscillating array of plate-shaped tracheal gills. As the nymph grows, the kinematics of these gills change abruptly from rowing to flapping. The classical fluid dynamics approach to consider the mayfly nymph as a pumping device fails in giving clear reasons for this switch. In order to shed some light on this switch between the two distinct kinematics, we analyze the problem under a <span class="hlt">Lagrangian</span> viewpoint. We consider that a good <span class="hlt">Lagrangian</span> transport that effectively distributes and stirs water and dissolved oxygen between and around the gills is the main goal of the gill motion. Using this <span class="hlt">Lagrangian</span> approach, we are able to provide possible reasons behind the observed switch from rowing to flapping. More precisely, we conduct a series of in silico mayfly nymph experiments, where body shape, as well as gill shapes, structures, and kinematics are matched to those from in vivo. In this paper, we show both qualitatively and quantitatively how the change of kinematics enables better attraction, confinement, and stirring of water charged of dissolved oxygen inside the gills area. We reveal the attracting barriers to transport, i.e., attracting <span class="hlt">Lagrangian</span> coherent structures, that form the transport skeleton between and around the gills. In addition, we quantify how well the fluid particles are stirred inside the gills area, which by extension leads us to conclude that it will increase the proneness of molecules of dissolved oxygen to be close enough to the gills for extraction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PhRvA..67a6101L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PhRvA..67a6101L"><span>Comment on ``Canonical formalism for <span class="hlt">Lagrangians</span> with nonlocality of finite extent''</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Llosa, Josep</p> <p>2003-01-01</p> <p>The paper by Woodward [Phys. Rev. A 62, 052105 (2000)] claimed to have proved that <span class="hlt">Lagrangian</span> theories with a nonlocality of finite extent are necessarily unstable. In this Comment we propose that this conclusion is false.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170003766&hterms=Vantage&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DVantage','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170003766&hterms=Vantage&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DVantage"><span>A Small Mission Concept to the Sun-Earth <span class="hlt">Lagrangian</span> L5 Point for Innovative Solar, Heliospheric and Space Weather Science</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lavraud, B.; Liu, Y.; Segura, K.; He, J.; Qin, G.; Temmer, M.; Vial, J.-C.; Xiong, M.; Davies, J. A.; Rouillard, A. P.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20170003766'); toggleEditAbsImage('author_20170003766_show'); toggleEditAbsImage('author_20170003766_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20170003766_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20170003766_hide"></p> <p>2016-01-01</p> <p>We present a concept for a small mission to the Sun-Earth <span class="hlt">Lagrangian</span> L5 point for innovative solar, heliospheric and space weather science. The proposed INvestigation of Solar-Terrestrial Activity aNd Transients (INSTANT) mission is designed to identify how solar coronal magnetic fields drive eruptions, <span class="hlt">mass</span> transport and particle acceleration that impact the Earth and the heliosphere. INSTANT is the first mission designed to (1) obtain measurements of coronal magnetic fields from space and (2) determine coronal <span class="hlt">mass</span> ejection (CME) kinematics with unparalleled accuracy. Thanks to innovative instrumentation at a vantage point that provides the most suitable perspective view of the Sun-Earth system, INSTANT would uniquely track the whole chain of fundamental processes driving space weather at Earth. We present the science requirements, payload and mission profile that fulfill ambitious science objectives within small mission programmatic boundary conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JASTP.146..171L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JASTP.146..171L"><span>A small mission concept to the Sun-Earth <span class="hlt">Lagrangian</span> L5 point for innovative solar, heliospheric and space weather science</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lavraud, B.; Liu, Y.; Segura, K.; He, J.; Qin, G.; Temmer, M.; Vial, J.-C.; Xiong, M.; Davies, J. A.; Rouillard, A. P.; Pinto, R.; Auchère, F.; Harrison, R. A.; Eyles, C.; Gan, W.; Lamy, P.; Xia, L.; Eastwood, J. P.; Kong, L.; Wang, J.; Wimmer-Schweingruber, R. F.; Zhang, S.; Zong, Q.; Soucek, J.; An, J.; Prech, L.; Zhang, A.; Rochus, P.; Bothmer, V.; Janvier, M.; Maksimovic, M.; Escoubet, C. P.; Kilpua, E. K. J.; Tappin, J.; Vainio, R.; Poedts, S.; Dunlop, M. W.; Savani, N.; Gopalswamy, N.; Bale, S. D.; Li, G.; Howard, T.; DeForest, C.; Webb, D.; Lugaz, N.; Fuselier, S. A.; Dalmasse, K.; Tallineau, J.; Vranken, D.; Fernández, J. G.</p> <p>2016-08-01</p> <p>We present a concept for a small mission to the Sun-Earth <span class="hlt">Lagrangian</span> L5 point for innovative solar, heliospheric and space weather science. The proposed INvestigation of Solar-Terrestrial Activity aNd Transients (INSTANT) mission is designed to identify how solar coronal magnetic fields drive eruptions, <span class="hlt">mass</span> transport and particle acceleration that impact the Earth and the heliosphere. INSTANT is the first mission designed to (1) obtain measurements of coronal magnetic fields from space and (2) determine coronal <span class="hlt">mass</span> ejection (CME) kinematics with unparalleled accuracy. Thanks to innovative instrumentation at a vantage point that provides the most suitable perspective view of the Sun-Earth system, INSTANT would uniquely track the whole chain of fundamental processes driving space weather at Earth. We present the science requirements, payload and mission profile that fulfill ambitious science objectives within small mission programmatic boundary conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014OcMod..76...20Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014OcMod..76...20Q"><span>Quantification of errors induced by temporal resolution on <span class="hlt">Lagrangian</span> particles in an eddy-resolving model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qin, Xuerong; van Sebille, Erik; Sen Gupta, Alexander</p> <p>2014-04-01</p> <p><span class="hlt">Lagrangian</span> particle tracking within ocean models is an important tool for the examination of ocean circulation, ventilation timescales and connectivity and is increasingly being used to understand ocean biogeochemistry. <span class="hlt">Lagrangian</span> trajectories are obtained by advecting particles within velocity fields derived from hydrodynamic ocean models. For studies of ocean flows on scales ranging from mesoscale up to basin scales, the temporal resolution of the velocity fields should ideally not be more than a few days to capture the high frequency variability that is inherent in mesoscale features. However, in reality, the model output is often archived at much lower temporal resolutions. Here, we quantify the differences in the <span class="hlt">Lagrangian</span> particle trajectories embedded in velocity fields of varying temporal resolution. Particles are advected from 3-day to 30-day averaged fields in a high-resolution global ocean circulation model. We also investigate whether adding lateral diffusion to the particle movement can compensate for the reduced temporal resolution. Trajectory errors reveal the expected degradation of accuracy in the trajectory positions when decreasing the temporal resolution of the velocity field. Divergence timescales associated with averaging velocity fields up to 30 days are faster than the intrinsic dispersion of the velocity fields but slower than the dispersion caused by the interannual variability of the velocity fields. In experiments focusing on the connectivity along major currents, including western boundary currents, the volume transport carried between two strategically placed sections tends to increase with increased temporal averaging. Simultaneously, the average travel times tend to decrease. Based on these two bulk measured diagnostics, <span class="hlt">Lagrangian</span> experiments that use temporal averaging of up to nine days show no significant degradation in the flow characteristics for a set of six currents investigated in more detail. The addition of random</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920016571&hterms=sing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsing','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920016571&hterms=sing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dsing"><span>A new <span class="hlt">Lagrangian</span> method for real gases at supersonic speed</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Loh, C. Y.; Liou, Meng-Sing</p> <p>1992-01-01</p> <p>With the renewed interest in high speed flights, the real gas effect is of theoretical as well as practical importance. In the past decade, upwind splittings or Godunov-type Riemann solutions have received tremendous attention and as a result significant progress has been made both in the ideal and non-ideal gas. In this paper, we propose a new approach that is formulated using the <span class="hlt">Lagrangian</span> description, for the calculation of supersonic/hypersonic real gas inviscid flows. This new formulation avoids the grid generation step which is automatically obtained as the solution procedure marches in the 'time-like' direction. As a result, no remapping is required and the accuracy is faithfully maintained in the <span class="hlt">Lagrangian</span> level. In this paper, we give numerical results for a variety of real gas problems consisting of essential elements in high speed flows, such as shock waves, expansion waves, slip surfaces and their interactions. Finally, calculations for flows in a generic inlet and nozzle are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22163082-contractions-ads-brane-algebra-supergalileon-lagrangians','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22163082-contractions-ads-brane-algebra-supergalileon-lagrangians"><span>Contractions of AdS brane algebra and superGalileon <span class="hlt">Lagrangians</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kamimura, Kiyoshi; Onda, Seiji</p> <p>2013-06-15</p> <p>We examine AdS Galileon <span class="hlt">Lagrangians</span> using the method of nonlinear realization. By contractions (1) flat curvature limit, (2) non-relativistic brane algebra limit, and (3) (1) + (2) limits we obtain DBI, Newton-Hoock, and Galilean Galileons, respectively. We make clear how these <span class="hlt">Lagrangians</span> appear as invariant 4-forms and/or pseudo-invariant Wess-Zumino (WZ) terms using Maurer-Cartan (MC) equations on the coset G/SO(3, 1). We show the equations of motion are written in terms of the MC forms only and explain why the inverse Higgs condition is obtained as the equation of motion for all cases. The supersymmetric extension is also examined using amore » supercoset SU(2, 2 Double-Vertical-Line 1)/(SO(3, 1) Multiplication-Sign U(1)) and five WZ forms are constructed. They are reduced to the corresponding five Galileon WZ forms in the bosonic limit and are candidates for supersymmetric Galileon action.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23944559','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23944559"><span><span class="hlt">Lagrangian</span> coherent structures separate dynamically distinct regions in fluid flows.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kelley, Douglas H; Allshouse, Michael R; Ouellette, Nicholas T</p> <p>2013-07-01</p> <p>Using filter-space techniques, we study the scale-to-scale transport of energy in a quasi-two-dimensional, weakly turbulent fluid flow averaged along the trajectories of fluid elements. We find that although the spatial mean of this <span class="hlt">Lagrangian</span>-averaged flux is nearly unchanged from its Eulerian counterpart, the spatial structure of the scale-to-scale energy flux changes significantly. In particular, its features appear to correlate with the positions of <span class="hlt">Lagrangian</span> coherent structures (LCS's). We show that the LCS's tend to lie at zeros of the scale-to-scale flux, and therefore that the LCS's separate regions that have qualitatively different dynamics. Since LCS's are also known to be impenetrable barriers to advection and mixing, we therefore find that the fluid on either side of an LCS is both kinematically and dynamically distinct. Our results extend the utility of LCS's by making clear the role they play in the flow dynamics in addition to the kinematics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1419712','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1419712"><span>Eulerian and <span class="hlt">Lagrangian</span> Parameterization of the Oceanic Mixed Layer using Large Eddy Simulation and MPAS-Ocean</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Van Roekel, Luke</p> <p></p> <p>We have conducted a suite of Large Eddy Simulation (LES) to form the basis of a multi-model comparison (left). The results have led to proposed model improvements. We have verified that Eulerian-<span class="hlt">Lagrangian</span> effective diffusivity estimates of mesoscale mixing are consistent with traditional particle statistics metrics (right). LES and <span class="hlt">Lagrangian</span> particles will be utilized to better represent the movement of water into and out of the mixed layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70015219','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70015219"><span><span class="hlt">LAGRANGIAN</span> MODELING OF A SUSPENDED-SEDIMENT PULSE.</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Schoellhamer, David H.</p> <p>1987-01-01</p> <p>The one-dimensional <span class="hlt">Lagrangian</span> Transport Model (LTM) has been applied in a quasi two-dimensional manner to simulate the transport of a slug injection of microbeads in steady experimental flows. A stationary bed segment was positioned below each parcel location to simulate temporary storage of beads on the bottom of the flume. Only one degree of freedom was available for all three bead simulations. The results show the versatility of the LTM and the ability of the LTM to accurately simulate transport of fine suspended sediment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22598997-lagrangian-velocity-acceleration-correlations-large-inertial-particles-closed-turbulent-flow','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22598997-lagrangian-velocity-acceleration-correlations-large-inertial-particles-closed-turbulent-flow"><span><span class="hlt">Lagrangian</span> velocity and acceleration correlations of large inertial particles in a closed turbulent flow</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Machicoane, Nathanaël; Volk, Romain</p> <p></p> <p>We investigate the response of large inertial particle to turbulent fluctuations in an inhomogeneous and anisotropic flow. We conduct a <span class="hlt">Lagrangian</span> study using particles both heavier and lighter than the surrounding fluid, and whose diameters are comparable to the flow integral scale. Both velocity and acceleration correlation functions are analyzed to compute the <span class="hlt">Lagrangian</span> integral time and the acceleration time scale of such particles. The knowledge of how size and density affect these time scales is crucial in understanding particle dynamics and may permit stochastic process modelization using two-time models (for instance, Sawford’s). As particles are tracked over long timesmore » in the quasi-totality of a closed flow, the mean flow influences their behaviour and also biases the velocity time statistics, in particular the velocity correlation functions. By using a method that allows for the computation of turbulent velocity trajectories, we can obtain unbiased <span class="hlt">Lagrangian</span> integral time. This is particularly useful in accessing the scale separation for such particles and to comparing it to the case of fluid particles in a similar configuration.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1429745','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1429745"><span>Heuristic approach to Satellite Range Scheduling with Bounds using <span class="hlt">Lagrangian</span> Relaxation.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Brown, Nathanael J. K.; Arguello, Bryan; Nozick, Linda Karen</p> <p></p> <p>This paper focuses on scheduling antennas to track satellites using a heuristic method. In order to validate the performance of the heuristic, bounds are developed using <span class="hlt">Lagrangian</span> relaxation. The performance of the algorithm is established using several illustrative problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017WRR....53.9040S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017WRR....53.9040S"><span>A <span class="hlt">Lagrangian</span> Transport Eulerian Reaction Spatial (LATERS) Markov Model for Prediction of Effective Bimolecular Reactive Transport</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sund, Nicole; Porta, Giovanni; Bolster, Diogo; Parashar, Rishi</p> <p>2017-11-01</p> <p>Prediction of effective transport for mixing-driven reactive systems at larger scales, requires accurate representation of mixing at small scales, which poses a significant upscaling challenge. Depending on the problem at hand, there can be benefits to using a <span class="hlt">Lagrangian</span> framework, while in others an Eulerian might have advantages. Here we propose and test a novel hybrid model which attempts to leverage benefits of each. Specifically, our framework provides a <span class="hlt">Lagrangian</span> closure required for a volume-averaging procedure of the advection diffusion reaction equation. This hybrid model is a <span class="hlt">LAgrangian</span> Transport Eulerian Reaction Spatial Markov model (LATERS Markov model), which extends previous implementations of the <span class="hlt">Lagrangian</span> Spatial Markov model and maps concentrations to an Eulerian grid to quantify closure terms required to calculate the volume-averaged reaction terms. The advantage of this approach is that the Spatial Markov model is known to provide accurate predictions of transport, particularly at preasymptotic early times, when assumptions required by traditional volume-averaging closures are least likely to hold; likewise, the Eulerian reaction method is efficient, because it does not require calculation of distances between particles. This manuscript introduces the LATERS Markov model and demonstrates by example its ability to accurately predict bimolecular reactive transport in a simple benchmark 2-D porous medium.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..DFDG35004M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..DFDG35004M"><span><span class="hlt">Lagrangian</span> Descriptors: A Method for Revealing Phase Space Structures of General Time Dependent Dynamical Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mancho, Ana M.; Wiggins, Stephen; Curbelo, Jezabel; Mendoza, Carolina</p> <p>2013-11-01</p> <p><span class="hlt">Lagrangian</span> descriptors are a recent technique which reveals geometrical structures in phase space and which are valid for aperiodically time dependent dynamical systems. We discuss a general methodology for constructing them and we discuss a ``heuristic argument'' that explains why this method is successful. We support this argument by explicit calculations on a benchmark problem. Several other benchmark examples are considered that allow us to assess the performance of <span class="hlt">Lagrangian</span> descriptors with both finite time Lyapunov exponents (FTLEs) and finite time averages of certain components of the vector field (``time averages''). In all cases <span class="hlt">Lagrangian</span> descriptors are shown to be both more accurate and computationally efficient than these methods. We thank CESGA for computing facilities. This research was supported by MINECO grants: MTM2011-26696, I-Math C3-0104, ICMAT Severo Ochoa project SEV-2011-0087, and CSIC grant OCEANTECH. SW acknowledges the support of the ONR (Grant No. N00014-01-1-0769).</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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