40 CFR 97.120 - General CAIR NOX Annual Trading Program permit requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false General CAIR NOX Annual Trading... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS Permits § 97.120 General CAIR NOX Annual Trading Program permit requirements. (a) For...

40 CFR 96.120 - General CAIR NOX Annual Trading Program permit requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false General CAIR NOX Annual Trading... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO 2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS Permits § 96.120 General CAIR NOX Annual Trading Program permit...

40 CFR 96.120 - General CAIR NOX Annual Trading Program permit requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false General CAIR NOX Annual Trading... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS Permits § 96.120 General CAIR NOX Annual Trading Program permit...

40 CFR 97.120 - General CAIR NOX Annual Trading Program permit requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false General CAIR NOX Annual Trading... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS Permits § 97.120 General CAIR NOX Annual Trading Program permit requirements. (a) For...

40 CFR 96.120 - General CAIR NOX Annual Trading Program permit requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false General CAIR NOX Annual Trading... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS Permits § 96.120 General CAIR NOX Annual Trading Program permit...

Form factors and generalized parton distributions in basis light-front quantization

NASA Astrophysics Data System (ADS)

Adhikari, Lekha; Li, Yang; Zhao, Xingbo; Maris, Pieter; Vary, James P.; El-Hady, Alaa Abd

2016-05-01

We calculate the elastic form factors and the generalized parton distributions (GPDs) for four low-lying bound states of a demonstration fermion-antifermion system, strong-coupling positronium (e e ¯ ), using basis light-front quantization (BLFQ). By using this approach, we also calculate the impact-parameter-dependent GPDs q (x ,b⃗⊥) to visualize the fermion density in the transverse plane (b⃗⊥). We compare selected results with corresponding quantities in the nonrelativistic limit to reveal relativistic effects. Our results establish the foundation within BLFQ for investigating the form factors and the GPDs for hadronic systems.

10 CFR 9.45 - Annual report to the Attorney General of the United States.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Annual report to the Attorney General of the United States... Regulations § 9.45 Annual report to the Attorney General of the United States. (a) On or before February 1 of each year, the NRC will submit a report covering the preceding fiscal year to the Attorney General of...

Using noble gases to investigate mountain-front recharge

USGS Publications Warehouse

Manning, A.H.; Solomon, D.K.

2003-01-01

Mountain-front recharge is a major component of recharge to inter-mountain basin-fill aquifers. The two components of mountain-front recharge are (1) subsurface inflow from the mountain block (subsurface inflow), and (2) infiltration from perennial and ephemeral streams near the mountain front (stream seepage). The magnitude of subsurface inflow is of central importance in source protection planning for basin-fill aquifers and in some water rights disputes, yet existing estimates carry large uncertainties. Stable isotope ratios can indicate the magnitude of mountain-front recharge relative to other components, but are generally incapable of distinguishing subsurface inflow from stream seepage. Noble gases provide an effective tool for determining the relative significance of subsurface inflow, specifically. Dissolved noble gas concentrations allow for the determination of recharge temperature, which is correlated with recharge elevation. The nature of this correlation cannot be assumed, however, and must be derived for the study area. The method is applied to the Salt Lake Valley Principal Aquifer in northern Utah to demonstrate its utility. Samples from 16 springs and mine tunnels in the adjacent Wasatch Mountains indicate that recharge temperature decreases with elevation at about the same rate as the mean annual air temperature, but is on average about 2??C cooler. Samples from 27 valley production wells yield recharge elevations ranging from the valley elevation (about 1500 m) to mid-mountain elevation (about 2500 m). Only six of the wells have recharge elevations less than 1800 m. Recharge elevations consistently greater than 2000 m in the southeastern part of the basin indicate that subsurface inflow constitutes most of the total recharge in this area. ?? 2003 Published by Elsevier Science B.V.

Light-Front Holography, Light-Front Wavefunctions, and Novel QCD Phenomena

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; de Teramond, Guy F.

2012-02-16

Light-Front Holography is one of the most remarkable features of the AdS/CFT correspondence. In spite of its present limitations it provides important physical insights into the nonperturbative regime of QCD and its transition to the perturbative domain. This novel framework allows hadronic amplitudes in a higher dimensional anti-de Sitter (AdS) space to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time. The model leads to an effective confining light-front QCD Hamiltonian and a single-variable light-front Schroedinger equation which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. The coordinate z inmore » AdS space is uniquely identified with a Lorentz-invariant coordinate {zeta} which measures the separation of the constituents within a hadron at equal light-front time and determines the off-shell dynamics of the bound-state wavefunctions, and thus the fall-off as a function of the invariant mass of the constituents. The soft-wall holographic model modified by a positive-sign dilaton metric, leads to a remarkable one-parameter description of nonperturbative hadron dynamics - a semi-classical frame-independent first approximation to the spectra and light-front wavefunctions of meson and baryons. The model predicts a Regge spectrum of linear trajectories with the same slope in the leading orbital angular momentum L of hadrons and the radial quantum number n. The hadron eigensolutions projected on the free Fock basis provides the complete set of valence and non-valence light-front Fock state wavefunctions {Psi}{sub n/H} (x{sub i}, k{sub {perpendicular}i}, {lambda}{sub i}) which describe the hadron's momentum and spin distributions needed to compute the direct measures of hadron structure at the quark and gluon level, such as elastic and transition form factors, distribution amplitudes, structure functions, generalized parton distributions and

General-Purpose Front End for Real-Time Data Processing

NASA Technical Reports Server (NTRS)

James, Mark

2007-01-01

FRONTIER is a computer program that functions as a front end for any of a variety of other software of both the artificial intelligence (AI) and conventional data-processing types. As used here, front end signifies interface software needed for acquiring and preprocessing data and making the data available for analysis by the other software. FRONTIER is reusable in that it can be rapidly tailored to any such other software with minimum effort. Each component of FRONTIER is programmable and is executed in an embedded virtual machine. Each component can be reconfigured during execution. The virtual-machine implementation making FRONTIER independent of the type of computing hardware on which it is executed.

General advancing front packing algorithm for the discrete element method

NASA Astrophysics Data System (ADS)

Morfa, Carlos A. Recarey; Pérez Morales, Irvin Pablo; de Farias, Márcio Muniz; de Navarra, Eugenio Oñate Ibañez; Valera, Roberto Roselló; Casañas, Harold Díaz-Guzmán

2018-01-01

A generic formulation of a new method for packing particles is presented. It is based on a constructive advancing front method, and uses Monte Carlo techniques for the generation of particle dimensions. The method can be used to obtain virtual dense packings of particles with several geometrical shapes. It employs continuous, discrete, and empirical statistical distributions in order to generate the dimensions of particles. The packing algorithm is very flexible and allows alternatives for: 1—the direction of the advancing front (inwards or outwards), 2—the selection of the local advancing front, 3—the method for placing a mobile particle in contact with others, and 4—the overlap checks. The algorithm also allows obtaining highly porous media when it is slightly modified. The use of the algorithm to generate real particle packings from grain size distribution curves, in order to carry out engineering applications, is illustrated. Finally, basic applications of the algorithm, which prove its effectiveness in the generation of a large number of particles, are carried out.

QCD and Light-Front Dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodsky, Stanley J.; de Teramond, Guy F.; /SLAC /Southern Denmark U., CP3-Origins /Costa Rica U.

2011-01-10

AdS/QCD, the correspondence between theories in a dilaton-modified five-dimensional anti-de Sitter space and confining field theories in physical space-time, provides a remarkable semiclassical model for hadron physics. Light-front holography allows hadronic amplitudes in the AdS fifth dimension to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time. The result is a single-variable light-front Schroedinger equation which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. The coordinate z in AdS space is uniquely identified with a Lorentz-invariant coordinate {zeta} which measures the separation of the constituents within a hadron at equalmore » light-front time and determines the off-shell dynamics of the bound state wavefunctions as a function of the invariant mass of the constituents. The hadron eigenstates generally have components with different orbital angular momentum; e.g., the proton eigenstate in AdS/QCD with massless quarks has L = 0 and L = 1 light-front Fock components with equal probability. Higher Fock states with extra quark-anti quark pairs also arise. The soft-wall model also predicts the form of the nonperturbative effective coupling and its {beta}-function. The AdS/QCD model can be systematically improved by using its complete orthonormal solutions to diagonalize the full QCD light-front Hamiltonian or by applying the Lippmann-Schwinger method to systematically include QCD interaction terms. Some novel features of QCD are discussed, including the consequences of confinement for quark and gluon condensates. A method for computing the hadronization of quark and gluon jets at the amplitude level is outlined.« less

Generalized internal model robust control for active front steering intervention

NASA Astrophysics Data System (ADS)

Wu, Jian; Zhao, Youqun; Ji, Xuewu; Liu, Yahui; Zhang, Lipeng

2015-03-01

Because of the tire nonlinearity and vehicle's parameters' uncertainties, robust control methods based on the worst cases, such as H ∞, µ synthesis, have been widely used in active front steering control, however, in order to guarantee the stability of active front steering system (AFS) controller, the robust control is at the cost of performance so that the robust controller is a little conservative and has low performance for AFS control. In this paper, a generalized internal model robust control (GIMC) that can overcome the contradiction between performance and stability is used in the AFS control. In GIMC, the Youla parameterization is used in an improved way. And GIMC controller includes two sections: a high performance controller designed for the nominal vehicle model and a robust controller compensating the vehicle parameters' uncertainties and some external disturbances. Simulations of double lane change (DLC) maneuver and that of braking on split- µ road are conducted to compare the performance and stability of the GIMC control, the nominal performance PID controller and the H ∞ controller. Simulation results show that the high nominal performance PID controller will be unstable under some extreme situations because of large vehicle's parameters variations, H ∞ controller is conservative so that the performance is a little low, and only the GIMC controller overcomes the contradiction between performance and robustness, which can both ensure the stability of the AFS controller and guarantee the high performance of the AFS controller. Therefore, the GIMC method proposed for AFS can overcome some disadvantages of control methods used by current AFS system, that is, can solve the instability of PID or LQP control methods and the low performance of the standard H ∞ controller.

Lag-driven motion in front propagation

NASA Astrophysics Data System (ADS)

Amor, Daniel R.; Fort, Joaquim

2013-10-01

Front propagation is a ubiquitous phenomenon. It arises in physical, biological and cross-disciplinary systems as diverse as flame propagation, superconductors, virus infections, cancer spread or transitions in human prehistory. Here we derive a single, approximate front speed from three rather different time-delayed reaction-diffusion models, suggesting a general law. According to our approximate speed, fronts are crucially driven by the lag times (periods during which individuals or particles do not move). Rather surprisingly, the approximate speed is able to explain the observed spread rates of completely different biophysical systems such as virus infections, the Neolithic transition in Europe, and postglacial tree recolonizations.

Mountain-front recharge along the eastern side of the Middle Rio Grande Basin, central New Mexico

USGS Publications Warehouse

Anderholm, Scott K.

2000-01-01

particular subarea using the different methods. Mountain-front recharge ranged from 0.7 to 15 percent of total annual precipitation in the subareas (percent recharge). Some of the smallest values of percent recharge were in the subareas in the southern part of the basin, which generally have low altitudes. The larger percent-recharge values were from subareas with higher altitudes. With existing information, determining which of the mountain- front recharge estimates is most accurate and the reasons for discrepancies among the different estimates is not possible. The chloride-balance method underestimates recharge if the chloride concentration used in the calculations for precipitation is too small or the chloride concentration in recharge is too large. Water-yield regression methods overestimate recharge if the amount of evapotranspiration of water that infiltrates into the channel bed of arroyos during runoff from summer thunderstorms is large.

Fronts in extended systems of bistable maps coupled via convolutions

NASA Astrophysics Data System (ADS)

Coutinho, Ricardo; Fernandez, Bastien

2004-01-01

An analysis of front dynamics in discrete time and spatially extended systems with general bistable nonlinearity is presented. The spatial coupling is given by the convolution with distribution functions. It allows us to treat in a unified way discrete, continuous or partly discrete and partly continuous diffusive interactions. We prove the existence of fronts and the uniqueness of their velocity. We also prove that the front velocity depends continuously on the parameters of the system. Finally, we show that every initial configuration that is an interface between the stable phases propagates asymptotically with the front velocity.

Cold fronts in the Colombian Caribbean Sea and their relationship to extreme wave events

NASA Astrophysics Data System (ADS)

Ortiz-Royero, J. C.; Otero, L. J.; Restrepo, J. C.; Ruiz, J.; Cadena, M.

2013-11-01

Extreme ocean waves in the Caribbean Sea are commonly related to the effects of storms and hurricanes during the months of June through November. The collapse of 200 m of the Puerto Colombia pier in March 2009 revealed the effects of meteorological phenomena other than storms and hurricanes that may be influencing the extreme wave regime in the Colombian Caribbean. The marked seasonality of these atmospheric fronts was established by analyzing the meteorological-marine reports of the Instituto de Hidrología, Meteorología y Estudios Ambientales of Colombia (IDEAM, based on its initials in Spanish) and the Centro de Investigación en Oceanografía y Meteorología of Colombia (CIOH, based on its initials in Spanish) during the last 16 yr. The highest number of cold fronts was observed during the months of January, February, and March, with 6 fronts occurring per year. An annual trend was observed and the highest number of fronts occurred in 2010 (20 in total); moreover, an annual strong relationship between the maximum average wave values and the cold fronts in the central zone of the Colombian Caribbean during the first three months of the year was established. In addition, the maximum values of the significant height produced by the passage of cold fronts during the last 16 yr were identified. Although the Colombian Caribbean has been affected by storms and hurricanes in the past, this research allows us to conclude that there is a strong relationship between cold fronts and the largest waves in the Colombian Caribbean during the last 16 yr, which have caused damage to coastal infrastructure. We verified that the passage of a cold front corresponded to the most significant extreme wave event of the last two decades in the Colombian Caribbean, which caused the structural collapse of the Puerto Colombia pier, located near the city of Barranquilla, between 5 and 10 March 2009. This information is invaluable when evaluating average and extreme wave regimes for the

Generalized self-similar unsteady gas flows behind the strong shock wave front

NASA Astrophysics Data System (ADS)

Bogatko, V. I.; Potekhina, E. A.

2018-05-01

Two-dimensional (plane and axially symmetric) nonstationary gas flows behind the front of a strong shock wave are considered. All the gas parameters are functions of the ratio of Cartesian coordinates to some degree of time tn, where n is a self-similarity index. The problem is solved in Lagrangian variables. It is shown that the resulting system of partial differential equations is suitable for constructing an iterative process. ¢he "thin shock layer" method is used to construct an approximate analytical solution of the problem. The limit solution of the problem is constructed. A formula for determining the path traversed by a gas particle in the shock layer along the front of a shock wave is obtained. A system of equations for determining the first approximation corrections is constructed.

The Barents Sea Polar Front in summer

NASA Astrophysics Data System (ADS)

Parsons, A. Rost; Bourke, Robert H.; Muench, Robin D.; Chiu, Ching-Sang; Lynch, James F.; Miller, James H.; Plueddemann, Albert J.; Pawlowicz, Richard

1996-06-01

In August 1992 a combined physical oceanography and acoustic tomography experiment was conducted to describe the Barents Sea Polar Front (BSPF) and investigate its impact on the regional oceanography. The study area was an 80 × 70 km grid east of Bear Island where the front exhibits topographic trapping along the northern slope of the Bear Island Trough. Conductivity-temperature-depth, current meter, and acoustic Doppler current profiler (ADCP) data, combined with tomographic cross sections, presented a highly resolved picture of the front in August. All hydrographic measurements were dominated by tidal signals, with the strongest signatures associated with the M2 and S2 semidiurnal species. Mean currents in the warm saline water to the south of the front, derived from a current meter mooring and ADCP data, were directed to the southwest and may be associated with a barotropic recirculation of Norwegian Atlantic Water (NAW) within the Bear Island Trough. The geostrophic component of the velocity was well correlated with the measured southwestward mean surface layer flow north of the front. The frontal structure was retrograde, as the frontal isopleths sloped opposite to the bathymetry. The surface signature of the front was dominated by salinity gradients associated with the confluence of Atlantic and Arctic water masses, both warmed by insolation to a depth of about 20 m. The surface manifestation of the front varied laterally on the order of 10 km associated with tidal oscillations. Below the mixed layer, temperature and salinity variations were compensating, defining a nearly barotropic front. The horizontal scale of the front in this region was ˜3 km or less. At middepth beneath the frontal interface, tomographic cross sections indicated a high-frequency (˜16 cpd) upslope motion of filaments of NAW origin. The summertime BSPF was confirmed to have many of the general characteristics of a shelf-slope frontal system [Mooers et al., 1978] as well as a

The effects of variable front persistence and intensity on mesopelagic fish communities: a comparison of three fronts in the California Current Ecosystem

NASA Astrophysics Data System (ADS)

Netburn, A. N.; Koslow, J. A.

2016-02-01

Although the strong physical gradients at fronts are primarily realized in the epipelagic, the biological impacts of frontal ecosystems can extend into mesopelagic waters. In 2008, Lara-Lopez et al. (2012) observed a significant shift in total biomass and community composition of migrating mesopelagic fishes at a strong persistent front off of the Pt. Conception area of the southern California Current Ecosystem. Through the California Current Ecosystem Long-Term Ecological Research Program, two additional intensive sampling cruises have been conducted on frontal systems in the general region. In 2011 and 2012, paired day and night midwater Matsuda-Oozeki-Hu trawls were conducted at stations located on either side of the fronts and at the fronts themselves, a suite of concurrent observations of the physical environment measured, and lower trophic levels sampled. Using satellite imagery, we estimate front duration of each of the 2008, 2011, and 2012 fronts, and investigate changes to the relative abundance and community composition across these systems, comparing the resolved patterns in 2011 and 2012 to those published from 2008. Results of this work will help address the questions: (1) What are the timescales required for front presence to impact mesopelagic fish communities? (2) Do different types of frontal systems (e.g., an eddy front vs. a "classic" front) result in different patterns of mesopelagic fish abundance and community composition? These answers will provide insight into the mechanisms of accumulation of fishes at fronts. As many mesopelagic fishes are important forage species for oceanic predators, understanding their response to the high productivity frontal systems is key to understanding ecosystem-wide impacts of fronts.

46 CFR 111.30-4 - Circuit breakers removable from the front.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Circuit breakers removable from the front. 111.30-4 Section 111.30-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-4 Circuit breakers removable from the front...

46 CFR 111.30-4 - Circuit breakers removable from the front.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Circuit breakers removable from the front. 111.30-4 Section 111.30-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-4 Circuit breakers removable from the front...

46 CFR 111.30-4 - Circuit breakers removable from the front.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Circuit breakers removable from the front. 111.30-4 Section 111.30-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-4 Circuit breakers removable from the front...

46 CFR 111.30-4 - Circuit breakers removable from the front.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Circuit breakers removable from the front. 111.30-4 Section 111.30-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-4 Circuit breakers removable from the front...

46 CFR 111.30-4 - Circuit breakers removable from the front.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Circuit breakers removable from the front. 111.30-4 Section 111.30-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-4 Circuit breakers removable from the front...

Supersymmetric Properties of Hadron Physics from Light-Front Holography and Superconformal Algebra and other Advances in Light-Front QCD

NASA Astrophysics Data System (ADS)

Brodsky, Stanley J.

2018-05-01

Light-front holography, together with superconformal algebra, have provided new insights into the physics of color confinement and the spectroscopy and dynamics of hadrons. As shown by de Alfaro, Fubini and Furlan, a mass scale can appear in the equations of motion without affecting the conformal invariance of the action if one adds a term to the Hamiltonian proportional to the dilatation operator or the special conformal operator. If one applies the procedure of de Alfaro et al. to the frame-independent light-front Hamiltonian, it leads uniquely to a confining q \\bar{q} potential κ ^4 ζ ^2, where ζ ^2 is the light-front radial variable related in momentum space to the q \\bar{q} invariant mass. The same result, including spin terms, is obtained using light-front holography—the duality between the front form and AdS_5, the space of isometries of the conformal group—if one modifies the action of AdS_5 by the dilaton e^{κ ^2 z^2} in the fifth dimension z. When one generalizes this procedure using superconformal algebra, the resulting light-front eigensolutions lead to a a unified Regge spectroscopy of meson, baryon, and tetraquarks, including supersymmetric relations between their masses and their wavefunctions. One also predicts hadronic light-front wavefunctions and observables such as structure functions, transverse momentum distributions, and the distribution amplitudes. The mass scale κ underlying confinement and hadron masses can be connected to the parameter Λ_{\\overline{MS}} in the QCD running coupling by matching the nonperturbative dynamics to the perturbative QCD regime. The result is an effective coupling α _s(Q^2) defined at all momenta. The matching of the high and low momentum transfer regimes determines a scale Q_0 which sets the interface between perturbative and nonperturbative hadron dynamics. I also discuss a number of applications of light-front phenomenology.

Frozen reaction fronts in steady flows: A burning-invariant-manifold perspective

NASA Astrophysics Data System (ADS)

Mahoney, John R.; Li, John; Boyer, Carleen; Solomon, Tom; Mitchell, Kevin A.

2015-12-01

The dynamics of fronts, such as chemical reaction fronts, propagating in two-dimensional fluid flows can be remarkably rich and varied. For time-invariant flows, the front dynamics may simplify, settling in to a steady state in which the reacted domain is static, and the front appears "frozen." Our central result is that these frozen fronts in the two-dimensional fluid are composed of segments of burning invariant manifolds, invariant manifolds of front-element dynamics in x y θ space, where θ is the front orientation. Burning invariant manifolds (BIMs) have been identified previously as important local barriers to front propagation in fluid flows. The relevance of BIMs for frozen fronts rests in their ability, under appropriate conditions, to form global barriers, separating reacted domains from nonreacted domains for all time. The second main result of this paper is an understanding of bifurcations that lead from a nonfrozen state to a frozen state, as well as bifurcations that change the topological structure of the frozen front. Although the primary results of this study apply to general fluid flows, our analysis focuses on a chain of vortices in a channel flow with an imposed wind. For this system, we present both experimental and numerical studies that support the theoretical analysis developed here.

OBLIQUE VIEW, FRONT ELEVATION, LOOKING WESTSOUTHWEST Mountain Home Air ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

OBLIQUE VIEW, FRONT ELEVATION, LOOKING WEST-SOUTHWEST - Mountain Home Air Force Base 1958 Senior Officers' Housing, General's Residence, Rabeni Street (originally Ivy Street), Mountain Home, Elmore County, ID

Supersymmetric Properties of Hadron Physics from Light-Front Holography and Superconformal Algebra and other Advances in Light-Front QCD

DOE PAGES

Brodsky, Stanley J.

2018-03-06

Here, light-front holography, together with superconformal algebra, have provided new insights into the physics of color confinement and the spectroscopy and dynamics of hadrons. As shown by de Alfaro, Fubini and Furlan, a mass scale can appear in the equations of motion without affecting the conformal invariance of the action if one adds a term to the Hamiltonian proportional to the dilatation operator or the special conformal operator. If one applies the procedure of de Alfaro et al. to the frame-independent light-front Hamiltonian, it leads uniquely to a confining qq¯ potential κ 4ζ 2, where ζ 2 is the light-frontmore » radial variable related in momentum space to the qq¯ invariant mass. The same result, including spin terms, is obtained using light-front holography—the duality between the front form and AdS 5, the space of isometries of the conformal group—if one modifies the action of AdS 5 by the dilaton e κ2 z2 in the fifth dimension z. When one generalizes this procedure using superconformal algebra, the resulting light-front eigensolutions lead to a a unified Regge spectroscopy of meson, baryon, and tetraquarks, including supersymmetric relations between their masses and their wavefunctions. One also predicts hadronic light-front wavefunctions and observables such as structure functions, transverse momentum distributions, and the distribution amplitudes. The mass scale κ underlying confinement and hadron masses can be connected to the parameter Λ MS¯ in the QCD running coupling by matching the nonperturbative dynamics to the perturbative QCD regime. The result is an effective coupling α s(Q 2) defined at all momenta. The matching of the high and low momentum transfer regimes determines a scale Q 0 which sets the interface between perturbative and nonperturbative hadron dynamics. I also discuss a number of applications of light-front phenomenology.« less

Supersymmetric Properties of Hadron Physics from Light-Front Holography and Superconformal Algebra and other Advances in Light-Front QCD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodsky, Stanley J.

Here, light-front holography, together with superconformal algebra, have provided new insights into the physics of color confinement and the spectroscopy and dynamics of hadrons. As shown by de Alfaro, Fubini and Furlan, a mass scale can appear in the equations of motion without affecting the conformal invariance of the action if one adds a term to the Hamiltonian proportional to the dilatation operator or the special conformal operator. If one applies the procedure of de Alfaro et al. to the frame-independent light-front Hamiltonian, it leads uniquely to a confining qq¯ potential κ 4ζ 2, where ζ 2 is the light-frontmore » radial variable related in momentum space to the qq¯ invariant mass. The same result, including spin terms, is obtained using light-front holography—the duality between the front form and AdS 5, the space of isometries of the conformal group—if one modifies the action of AdS 5 by the dilaton e κ2 z2 in the fifth dimension z. When one generalizes this procedure using superconformal algebra, the resulting light-front eigensolutions lead to a a unified Regge spectroscopy of meson, baryon, and tetraquarks, including supersymmetric relations between their masses and their wavefunctions. One also predicts hadronic light-front wavefunctions and observables such as structure functions, transverse momentum distributions, and the distribution amplitudes. The mass scale κ underlying confinement and hadron masses can be connected to the parameter Λ MS¯ in the QCD running coupling by matching the nonperturbative dynamics to the perturbative QCD regime. The result is an effective coupling α s(Q 2) defined at all momenta. The matching of the high and low momentum transfer regimes determines a scale Q 0 which sets the interface between perturbative and nonperturbative hadron dynamics. I also discuss a number of applications of light-front phenomenology.« less

General aviation activity and avionics survey. Annual report for CY81

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwenk, J.C.; Carter, P.W.

1982-12-01

This report presents the results and a description of the 1981 General Aviation Activity and Avionics Survey. The survey was conducted during 1982 by the FAA to obtain information on the activity and avionics of the United States registered general aviation aircraft fleet, the dominant component of civil aviation in the U.S. The survey was based on a statistically selected sample of about 8.9 percent of the general aviation fleet and obtained a response rate of 61 percent. Survey results are based upon response but are expanded upward to represent the total population. Survey results revealed that during 1981 anmore » estimated 40.7 million hours of flying time were logged by the 213,226 active general aviation aircraft in the U.S. fleet, yielding a mean annual flight time per aircraft of 188.1 hours. The active aircraft represented about 83 percent of the registered general aviation fleet. The report contains breakdowns of these and other statistics by manufacturer/model group, aircraft type, state and region of based aircraft, and primary use. Also included are fuel consumption, lifetime airframe hours, avionics, and engine hours estimates. In addition, tables are included for detailed analysis of the avionics capabilities of GA fleet.« less

View of front of garage bays 57, facing northeast. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of front of garage bays 5-7, facing northeast. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

View of front of garage, bays 37, facing south ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of front of garage, bays 3-7, facing south - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

View of front of garage, bays 14, facing northeast ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of front of garage, bays 1-4, facing northeast - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

Superconformal Baryon-Meson Symmetry and Light-Front Holographic QCD

DOE PAGES

Dosch, Hans Guenter; de Teramond, Guy F.; Brodsky, Stanley J.

2015-04-10

We construct an effective QCD light-front Hamiltonian for both mesons and baryons in the chiral limit based on the generalized supercharges of a superconformal graded algebra. The superconformal construction is shown to be equivalent to a semi-classical approximation to light-front QCD and its embedding in AdS space. The specific breaking of conformal invariance inside the graded algebra uniquely determines the effective confinement potential. The generalized supercharges connect the baryon and meson spectra to each other in a remarkable manner. In particular, the π/b 1 Regge trajectory is identified as the superpartner of the nucleon trajectory. However, the lowest-lying state onmore » this trajectory, the π-meson is massless in the chiral limit and has no supersymmetric partner.« less

Characterization and effects of cold fronts in the Colombian Caribbean Coast and their relationship to extreme wave events

NASA Astrophysics Data System (ADS)

Ortiz-Royero, J. C.; Otero, L. J.; Restrepo, J. C.; Ruiz, J.; Cadena, M.

2013-07-01

Extreme ocean waves in the Caribbean Sea are commonly related to the effects of storms and hurricanes during the months of June through November. The collapse of 200 m of the Puerto Colombia pier in March 2009 revealed the effects of meteorological phenomena other than storms and hurricanes that may be influencing the extreme wave regime in the Colombian Caribbean. The marked seasonality of these atmospheric fronts was established by analyzing the meteorological-marine reports of Instituto de Hidrología, Meteorología y Estudios Ambientales of Colombia (IDEAM, based on its initials in Spanish) and Centro de Investigación en Oceanografía y Meteorología of Colombia (CIOH, based on its initials in Spanish). The highest occurrences were observed during the months of January, February, and March, with 6 fronts occurring per year. An annual trend was not observed, although the highest number of fronts occurred in 2010 (20 in total). An annual strong relationship between the maximum average wave values and the cold fronts, in the central zone of the Colombian Caribbean during the first three months of the year was established. In addition, the maximum values of the significant height produced by the passage of cold fronts during the last 16 yr were identified. Although the Colombian Caribbean has been affected by storms and hurricanes in the past, this research allows us to conclude that, there is a strong relationship between cold fronts and the largest waves in the Colombian Caribbean during the last 16 yr, which have caused damage to coastal infrastructure. We verified that the passage of a cold front corresponded to the most significant extreme wave event of the last two decades in the Colombian Caribbean, which caused the structural collapse of the Puerto Colombia pier, located near the city of Barranquilla, between 5 and 10 March 2009. This information is invaluable when evaluating average and extreme wave regimes for the purpose of informing the design of

Angular momentum conservation law in light-front quantum field theory

DOE PAGES

Chiu, Kelly Yu-Ju; Brodsky, Stanley J.

2017-03-31

We prove the Lorentz invariance of the angular momentum conservation law and the helicity sum rule for relativistic composite systems in the light-front formulation. We explicitly show that j 3, the z -component of the angular momentum remains unchanged under Lorentz transformations generated by the light-front kinematical boost operators. The invariance of j 3 under Lorentz transformations is a feature unique to the front form. Applying the Lorentz invariance of the angular quantum number in the front form, we obtain a selection rule for the orbital angular momentum which can be used to eliminate certain interaction vertices in QED andmore » QCD. We also generalize the selection rule to any renormalizable theory and show that there exists an upper bound on the change of orbital angular momentum in scattering processes at any fixed order in perturbation theory.« less

Angular momentum conservation law in light-front quantum field theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiu, Kelly Yu-Ju; Brodsky, Stanley J.

We prove the Lorentz invariance of the angular momentum conservation law and the helicity sum rule for relativistic composite systems in the light-front formulation. We explicitly show that j 3, the z -component of the angular momentum remains unchanged under Lorentz transformations generated by the light-front kinematical boost operators. The invariance of j 3 under Lorentz transformations is a feature unique to the front form. Applying the Lorentz invariance of the angular quantum number in the front form, we obtain a selection rule for the orbital angular momentum which can be used to eliminate certain interaction vertices in QED andmore » QCD. We also generalize the selection rule to any renormalizable theory and show that there exists an upper bound on the change of orbital angular momentum in scattering processes at any fixed order in perturbation theory.« less

Angular momentum conservation law in light-front quantum field theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiu, Kelly Yu-Ju; Brodsky, Stanley J.

We prove the Lorentz invariance of the angular momentum conservation law and the helicity sum rule for relativistic composite systems in the light-front formulation. We explicitly show that j 3 , the z -component of the angular momentum remains unchanged under Lorentz transformations generated by the light-front kinematical boost operators. The invariance of j 3 under Lorentz transformations is a feature unique to the front form. Applying the Lorentz invariance of the angular quantum number in the front form, we obtain a selection rule for the orbital angular momentum which can be used to eliminate certain interaction vertices in QEDmore » and QCD. We also generalize the selection rule to any renormalizable theory and show that there exists an upper bound on the change of orbital angular momentum in scattering processes at any fixed order in perturbation theory.« less

Turbulent transport model of wind shear in thunderstorm gust fronts and warm fronts

NASA Technical Reports Server (NTRS)

Lewellen, W. S.; Teske, M. E.; Segur, H. C. O.

1978-01-01

A model of turbulent flow in the atmospheric boundary layer was used to simulate the low-level wind and turbulence profiles associated with both local thunderstorm gust fronts and synoptic-scale warm fronts. Dimensional analyses of both type fronts provided the physical scaling necessary to permit normalized simulations to represent fronts for any temperature jump. The sensitivity of the thunderstorm gust front to five different dimensionless parameters as well as a change from axisymmetric to planar geometry was examined. The sensitivity of the warm front to variations in the Rossby number was examined. Results of the simulations are discussed in terms of the conditions which lead to wind shears which are likely to be most hazardous for aircraft operations.

Seasonal Atmospheric Argon Variability Measured in the Equatorial Region of Mars by the Mars Exploration Rover Alpha Particle X-Ray Spectrometers: Evidence for an Annual Argon-Enriched Front

NASA Astrophysics Data System (ADS)

VanBommel, S. J.; Gellert, R.; Clark, B. C.; Ming, D. W.

2018-02-01

The Mars Exploration Rover Opportunity (MER-B) has been exploring the surface of Mars since landing in 2004. Its Alpha Particle X-ray Spectrometer (APXS) is primarily used to interrogate the chemical composition of rocks and soil samples in situ. Additionally, the APXS has measured the atmosphere of Mars with a regular cadence, monitoring the change in relative atmospheric argon density. Atmospheric measurements with the MER-B APXS span over six Mars years providing an unprecedented level of statistics for careful study of the ubiquitous APXS spectral background. Several models were applied to high-frequency long-duration Spirit rover atmospheric APXS measurements. The most stable model with the least uncertainty was applied to the MER-B data set. Seasonal variation of 10-15% in equatorial atmospheric argon density was observed - in agreement with existing literature and global climate models. Unseen in previous work and global climate models, an abrupt deviation from the model-predicted annual mixing ratio was measured by the MER-B APXS around Ls 150. The sharp change, 10% over 10° Ls, provides strong evidence for a northward migrating front, enriched in argon, sourced from the south pole at the end of southern winter. A similar weaker front is possibly observed around Ls 325, sourced from the northern polar region.

35. EAST FRONT OF POWERHOUSE AND CAR BARN: East front ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

35. EAST FRONT OF POWERHOUSE AND CAR BARN: East front of powerhouse and car barn. 'Annex' is right end of building. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

9. DETAIL OF INTERIOR OF FRONT PORCH SHOWING FRONT ENTRY ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. DETAIL OF INTERIOR OF FRONT PORCH SHOWING FRONT ENTRY (LEFT) AND BLANK WALL (CENTER) CORRESPONDING TO LOCATION OF INTERIOR VAULTS. VIEW TO SOUTHEAST. - Boise Project, Boise Project Office, 214 Broadway, Boise, Ada County, ID

3. VIEW NORTH, SOUTHWEST FRONT, SOUTHEAST SIDE Front and side ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. VIEW NORTH, SOUTHWEST FRONT, SOUTHEAST SIDE Front and side elevation. Note gasoline sign post added. Flush store window not altered, 1900 clapboard siding and panelling remaining. - 510 Central Avenue (Commercial Building), Ridgely, Caroline County, MD

Shelf sea tidal currents and mixing fronts determined from ocean glider observations

NASA Astrophysics Data System (ADS)

Sheehan, Peter M. F.; Berx, Barbara; Gallego, Alejandro; Hall, Rob A.; Heywood, Karen J.; Hughes, Sarah L.; Queste, Bastien Y.

2018-03-01

capture the period when the front makes the transition from its summertime to wintertime state. Fronts in other shelf sea regions with oceanic influence may exhibit similar behaviour, with controlling processes and locations changing over an annual cycle. These results have implications for the thermohaline circulation of shelf seas.

General aviation activity and avionics survey. 1978. Annual summary report cy 1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwenk, J.C.

1980-03-01

This report presents the results and a description of the 1978 General Aviation Activity and Avionics Survey. The survey was conducted during early 1979 by the FAA to obtain information on the activity and avionics of the United States registered general aviation aircraft fleet, the dominant component of civil aviation in the U.S. The survey was based on a statistically selected sample of about 13.3 percent of the general aviation fleet and obtained a response rate of 74 percent. Survey results are based upon responses but are expanded upward to represent the total population. Survey results revealed that during 1978more » an estimated 39.4 million hours of flying time were logged by the 198,778 active general aviation aircraft in the U.S. fleet, yielding a mean annual flight time per aircraft of 197.7 hours. The active aircraft represented 85 percent of the registered general aviation fleet. The report contains breakdowns of these and other statistics by manufacturer/model group, aircraft type, state and region of based aircraft, and primary use. Also included are fuel consumption, lifetime airframe hours, avionics, and engine hours estimates.« less

On the existence of stationary reaction fronts in precipitation-dissolution systems

NASA Astrophysics Data System (ADS)

Kondratiuk, Paweł; Nizinkiewicz, Hanna; Ladd, Anthony JC; Szymczak, Piotr

2014-05-01

Coupled precipitation-dissolution processes are ubiquitous in hydrogeochemical systems which are out of chemical equilibrium. However, as already remarked by Ortoleva et al. [1], the precipitation front will in general move with a velocity different form that of a dissolution front; thus the distance between them will increase in time. However, there are a number of systems where the both fronts appear to move with the same velocity. One example is the terra rossa formation process [2], in which kaolinite precipitation produces hydrogen ions that dissolve the underlying calcite. In this case the velocities of the dissolution and precipitation front agree to within 1%, which does not seem accidental. In this communication, we propose a possible mechanism of such a front synchronization, and study its further implications for the dynamics of the system. [1] P. Ortoleva et al., Physica D: 19, 334 (1986) [2] E. Merino and A. Banjerjee, J. Geol., 116, 62 (2008)

General aviation activity and avionics survey. Annual summary report, CY 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1987-03-01

This report presents the results and a description of the 1985 General Aviation Activity and Avionics Survey. The survey was conducted during 1986 by the FAA to obtain information on the activity and avionics of the United States registered general aviation aircraft fleet, the dominant component of civil aviation in the U.S. The survey was based on a statistically selected sample of about 10.3 percent of the general aviation fleet. A responses rate of 63.7 percent was obtained. Survey results based upon response but are expanded upward to represent the total population. Survey results revealed that during 1985 an estimatedmore » 34.1 million hours of flying time were logged and 88.7 million operations were performed by the 210,654 active general aviation aircraft in the U.S. fleet. The mean annual flight time per aircraft was 158.2 hours. The active aircraft represented about 77.9 percent of the registered general aviation fleet. The report contains breakdowns of these and other statistics by manufacturer/model group, aircraft, state and region of based aircraft, and primary use. Also included are fuel consumption, lifetime airframe hours, avionics, engine hours, and miles flown estimates, as well as tables for detailed analysis of the avionics capabilities of the general aviation fleet. New to the report this year are estimates of the number of landings, IFR hours flown, and the cost and grade of fuel consumed by the GA fleet.« less

Front (west side) and south side of building Fitzsimons ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Front (west side) and south side of building - Fitzsimons General Hospital, Golf Course Waiting Shelter, Southwest area of Golf Course, 700 feet Northeast of intersection of West Harlow Avenue & Peoria Street, Aurora, Adams County, CO

Calculating complete and exact Pareto front for multiobjective optimization: a new deterministic approach for discrete problems.

PubMed

Hu, Xiao-Bing; Wang, Ming; Di Paolo, Ezequiel

2013-06-01

Searching the Pareto front for multiobjective optimization problems usually involves the use of a population-based search algorithm or of a deterministic method with a set of different single aggregate objective functions. The results are, in fact, only approximations of the real Pareto front. In this paper, we propose a new deterministic approach capable of fully determining the real Pareto front for those discrete problems for which it is possible to construct optimization algorithms to find the k best solutions to each of the single-objective problems. To this end, two theoretical conditions are given to guarantee the finding of the actual Pareto front rather than its approximation. Then, a general methodology for designing a deterministic search procedure is proposed. A case study is conducted, where by following the general methodology, a ripple-spreading algorithm is designed to calculate the complete exact Pareto front for multiobjective route optimization. When compared with traditional Pareto front search methods, the obvious advantage of the proposed approach is its unique capability of finding the complete Pareto front. This is illustrated by the simulation results in terms of both solution quality and computational efficiency.

A CloudSat-CALIPSO View of Cloud and Precipitation Properties Across Cold Fronts over the Global Oceans

NASA Technical Reports Server (NTRS)

Naud, Catherine M.; Posselt, Derek J.; van den Heever, Susan C.

2015-01-01

The distribution of cloud and precipitation properties across oceanic extratropical cyclone cold fronts is examined using four years of combined CloudSat radar and CALIPSO lidar retrievals. The global annual mean cloud and precipitation distributions show that low-level clouds are ubiquitous in the post frontal zone while higher-level cloud frequency and precipitation peak in the warm sector along the surface front. Increases in temperature and moisture within the cold front region are associated with larger high-level but lower mid-/low level cloud frequencies and precipitation decreases in the cold sector. This behavior seems to be related to a shift from stratiform to convective clouds and precipitation. Stronger ascent in the warm conveyor belt tends to enhance cloudiness and precipitation across the cold front. A strong temperature contrast between the warm and cold sectors also encourages greater post-cold-frontal cloud occurrence. While the seasonal contrasts in environmental temperature, moisture, and ascent strength are enough to explain most of the variations in cloud and precipitation across cold fronts in both hemispheres, they do not fully explain the differences between Northern and Southern Hemisphere cold fronts. These differences are better explained when the impact of the contrast in temperature across the cold front is also considered. In addition, these large-scale parameters do not explain the relatively large frequency in springtime post frontal precipitation.

2. VIEW NORTHEAST, SOUTHWEST FRONT Front elevation. Note the altered ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. VIEW NORTHEAST, SOUTHWEST FRONT Front elevation. Note the altered center section where a storefront was removed. Note addition of a door for entrance to stairway to living quarters added to the second floor. - 510 Central Avenue (Commercial Building), Ridgely, Caroline County, MD

FACILITY 1042. FRONT OBLIQUE SHOWING ROYAL PALMS LINING FRONT WALK. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FACILITY 1042. FRONT OBLIQUE SHOWING ROYAL PALMS LINING FRONT WALK. VIEW FACING SOUTHEAST - U.S. Naval Base, Pearl Harbor, Naval Housing Area Hale Alii, Junior Officers' Quarters Type, 9-10 Hale Alii Avenue, 1-2 Eighth Street, Pearl City, Honolulu County, HI

Digital-map grids of mean-annual precipitation for 1961-90, and generalized skew coefficients of annual maximum streamflow for Oklahoma

USGS Publications Warehouse

Rea, A.H.; Tortorelli, R.L.

1997-01-01

This digital report contains two digital-map grids of data that were used to develop peak-flow regression equations in Tortorelli, 1997, 'Techniques for estimating peak-streamflow frequency for unregulated streams and streams regulated by small floodwater retarding structures in Oklahoma,' U.S. Geological Survey Water-Resources Investigations Report 97-4202. One data set is a grid of mean annual precipitation, in inches, based on the period 1961-90, for Oklahoma. The data set was derived from the PRISM (Parameter-elevation Regressions on Independent Slopes Model) mean annual precipitation grid for the United States, developed by Daly, Neilson, and Phillips (1994, 'A statistical-topographic model for mapping climatological precipitation over mountainous terrain:' Journal of Applied Meteorology, v. 33, no. 2, p. 140-158). The second data set is a grid of generalized skew coefficients of logarithms of annual maximum streamflow for Oklahoma streams less than or equal to 2,510 square miles in drainage area. This grid of skew coefficients is taken from figure 11 of Tortorelli and Bergman, 1985, 'Techniques for estimating flood peak discharges for unregulated streams and streams regulated by small floodwater retarding structures in Oklahoma,' U.S. Geological Survey Water-Resources Investigations Report 84-4358. To save disk space, the skew coefficient values have been multiplied by 100 and rounded to integers with two significant digits. The data sets are provided in an ASCII grid format.

Burning invariant manifolds for reaction fronts in three-dimensional fluid flows

NASA Astrophysics Data System (ADS)

Mitchell, Kevin; Solomon, Tom

2017-11-01

The geometry of reaction fronts that propagate in fully three-dimensional (3D) fluid flows is studied using the tools of dynamical systems theory. The evolution of an infinitesimal front element is modeled as a six-dimensional ODE-three dimensions for the position of the front element and three for the orientation of its unit normal. This generalizes an earlier approach to understanding front propagation in two-dimensional (2D) fluid flows. As in 2D, the 3D system exhibits prominent burning invariant manifolds (BIMs). In 3D, BIMs are two-dimensional dynamically defined surfaces that form one-way barriers to the propagation of reaction fronts within the fluid. Due to the third dimension, BIMs in 3D exhibit a richer topology than their cousins in 2D. In particular, whereas BIMs in both 2D and 3D can originate from fixed points of the dynamics, BIMs in 3D can also originate from limit cycles. Such BIMs form robust tube-like channels that guide and constrain the evolution of the front within the bulk of the fluid. Supported by NSF Grant CMMI-1201236.

Assessing Attentional Prioritization of Front-of-Pack Nutrition Labels using Change Detection

PubMed Central

Becker, Mark W.; Sundar, Raghav Prashant; Bello, Nora; Alzahabi, Reem; Weatherspoon, Lorraine; Bix, Laura

2015-01-01

We used a change detection method to evaluate attentional prioritization of nutrition information that appears in the traditional “Nutrition Facts Panel” and in front-of-pack nutrition labels. Results provide compelling evidence that front-of-pack labels attract attention more readily than the Nutrition Facts Panel, even when participants are not specifically tasked with searching for nutrition information. Further, color-coding the relative nutritional value of key nutrients within the front-of-pack label resulted in increased attentional prioritization of nutrition information, but coding using facial icons did not significantly increase attention to the label. Finally, the general pattern of attentional prioritization across front-of-pack designs was consistent across a diverse sample of participants. Our results indicate that color-coded, front-of-pack nutrition labels increase attention to the nutrition information of packaged food, a finding that has implications for current policy discussions regarding labeling change. PMID:26851468

VIEW OF FRONT, RECESSED ENTRY SHOWING FRONT WALK. VIEW FACING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF FRONT, RECESSED ENTRY SHOWING FRONT WALK. VIEW FACING SOUTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 9, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

Guide for preparing annual reports on radiation-safety testing of electronic products (general)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

For manufacturers of electronic products other than those for which a specific guide has been issued, the guide replaces the Guide for the Filing of Annual Reports (21 CFR Subchapter J, Section 1002.11), HHS Publication FDA 82-8127. The electronic product (general) annual reporting guide is applicable to the following products: products intended to produce x radiation (accelerators, analytical devices, therapy x-ray machines); microwave diathermy machines; cold-cathode discharge tubes; and vacuum switches and tubes operating at or above 15,000 volts. To carry out its responsibilities under Public Law 90-602, the Food and Drug Administration's Center for Devices and Radiological Health (CDRH)more » has issued a series of regulations contained in Title 21 of the Code of Federal Regulations (CFR). Part 1002 of 21 CFR deals with records and reports. Section 1002.61 categorizes electronic products into Groups A through C. Section 1002.30 requires manufacturers of products in Groups B and C to establish and maintain certain records, while Section 1002.11 requires such manufacturers to submit an Annual Report summarizing the contents of the required records. Section 1002.7 requires that reports conform to reporting guides issued by CDRH unless an acceptable justification for an alternate format is provided.« less

View of front and side of garage, bay 7, facing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of front and side of garage, bay 7, facing east. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

Methods for estimating streamflow at mountain fronts in southern New Mexico

USGS Publications Warehouse

Waltemeyer, S.D.

1994-01-01

The infiltration of streamflow is potential recharge to alluvial-basin aquifers at or near mountain fronts in southern New Mexico. Data for 13 streamflow-gaging stations were used to determine a relation between mean annual stream- flow and basin and climatic conditions. Regression analysis was used to develop an equation that can be used to estimate mean annual streamflow on the basis of drainage areas and mean annual precipi- tation. The average standard error of estimate for this equation is 46 percent. Regression analysis also was used to develop an equation to estimate mean annual streamflow on the basis of active- channel width. Measurements of the width of active channels were determined for 6 of the 13 gaging stations. The average standard error of estimate for this relation is 29 percent. Stream- flow estimates made using a regression equation based on channel geometry are considered more reliable than estimates made from an equation based on regional relations of basin and climatic conditions. The sample size used to develop these relations was small, however, and the reported standard error of estimate may not represent that of the entire population. Active-channel-width measurements were made at 23 ungaged sites along the Rio Grande upstream from Elephant Butte Reservoir. Data for additional sites would be needed for a more comprehensive assessment of mean annual streamflow in southern New Mexico.

AdS/QCD and Applications of Light-Front Holography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; Cao, Fu-Guang

2012-02-16

Light-Front Holography leads to a rigorous connection between hadronic amplitudes in a higher dimensional anti-de Sitter (AdS) space and frame-independent light-front wavefunctions of hadrons in 3 + 1 physical space-time, thus providing a compelling physical interpretation of the AdS/CFT correspondence principle and AdS/QCD, a useful framework which describes the correspondence between theories in a modified AdS5 background and confining field theories in physical space-time. To a first semiclassical approximation, where quantum loops and quark masses are not included, this approach leads to a single-variable light-front Schroedinger equation which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spinmore » and orbital angular momentum. The coordinate z in AdS space is uniquely identified with a Lorentz-invariant coordinate {zeta} which measures the separation of the constituents within a hadron at equal light-front time. The internal structure of hadrons is explicitly introduced and the angular momentum of the constituents plays a key role. We give an overview of the light-front holographic approach to strongly coupled QCD. In particular, we study the photon-to-meson transition form factors (TFFs) F{sub M{gamma}}(Q{sup 2}) for {gamma}{gamma}* {yields} M using light-front holographic methods. The results for the TFFs for the {eta} and {eta}' mesons are also presented. Some novel features of QCD are discussed, including the consequences of confinement for quark and gluon condensates. A method for computing the hadronization of quark and gluon jets at the amplitude level is outlined.« less

View of front and side of garage, bays 67, facing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of front and side of garage, bays 6-7, facing northeast. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

View of front of garage, detail of building number over ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of front of garage, detail of building number over bay 4. - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

The 2014 Annual(MCWG)Annual Metrology and Calibration Working Gr

NASA Image and Video Library

2014-05-07

Annual Metrology and Calibration Working Group Face to Face meeting held at Langley Research Center; Front Row (L to R): Stacy Sigmon – LaRC, Brent Watling – JSC, Ralph Hickman – WFF, Kirk Foster – MSFC, Don Wilson – SSC, Greg Boyd – JSC, Perry King – KSC, Bobby Price – GSFC, Felicia Donnell – GSFC, Perry LaRosa – GRC. Second Row (L to R): Ken Mathews – KSC, Darrell Shoup – WSTF, Gary Kennedy – MSFC, Terry Fleet – GRC, Damon Flansburg – ARC, Salvatore Tomaselli - WFF, Bruce Farner - SSC, David Scott – JPL, Jim Wachter – KSC, Shawn Britton – LaRC.

6. Photocopy of drawing (from Annual Report of the Supervising ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. Photocopy of drawing (from Annual Report of the Supervising Architect for the Year 1877. Washington, D.C.: Government Printing Office, between pp. 10-11.) James G. Hill, Supervising Architect, Treasury Department SOUTH FRONT AND WEST SIDE - United States Post Office & Courthouse, Third & Walnut Streets, Harrisburg, Dauphin County, PA

Relating precipitation to fronts at a sub-daily basis

NASA Astrophysics Data System (ADS)

Hénin, Riccardo; Ramos, Alexandre M.; Liberato, Margarida L. R.; Gouveia, Célia

2017-04-01

High impact events over Western Iberia include precipitation extremes that are cause for concern as they lead to flooding, landslides, extensive property damage and human casualties. These events are usually associated with low pressure systems over the North Atlantic moving eastward towards the European western coasts (Liberato and Trigo, 2014). A method to detect fronts and to associate amounts of precipitation to each front is tested, distinguishing between warm and cold fronts. The 6-hourly ERA-interim 1979-2012 reanalysis with 1°x1° horizontal resolution is used for the purpose. An objective front identification method (the Thermal Method described in Shemm et al., 2014) is applied to locate fronts all over the Northern Hemisphere considering the equivalent potential temperature as thermal parameter to use in the model. On the other hand, we settled a squared search box of tuneable dimension (from 2 to 10 degrees long) to look for a front in the neighbourhood of a grid point affected by precipitation. A sensitivity analysis is performed and the optimal dimension of the box is assessed in order to avoid over(under) estimation of precipitation. This is performed in the light of the variability and typical dynamics of warm/cold frontal systems in the Western Europe region. Afterwards, using the extreme event ranking over Iberia proposed by Ramos et al. (2014) the first ranked extreme events are selected in order to validate the method with specific case studies. Finally, climatological and trend maps of frontal activity are produced both on annual and seasonal scales. Trend maps show a decrease of frontal precipitation over north-western Europe and a slight increase over south-western Europe, mainly due to warm fronts. REFERENCES Liberato M.L.R. and R.M. Trigo (2014) Extreme precipitation events and related impacts in Western Iberia. Hydrology in a Changing World: Environmental and Human Dimensions. IAHS Red Book No 363, 171-176. ISSN: 0144-7815. Ramos A.M., R

Polarization and wavelength diversities of Gulf Stream fronts imaged by AIRSAR

NASA Technical Reports Server (NTRS)

Lee, J. S.; Jansen, R. W.; Marmorino, G. O.; Chubb, S. R.

1995-01-01

During the 1990 Gulf Stream Experiment, NASA/JPL AIRSAR imaged the north edge of the Gulf Stream near the coast of Virginia. Simultaneous in-situ measurements of currents, temperatures, salinities, etc. were made for several crossings of the north edge by the R/V Cape Henlopen. Measurements identified two fronts with shearing and converging flows. The polarimetric SAR images from the fronts showed two bright linear features. One of them corresponds to the temperature front, which separated the warm Gulf Stream water to the south from a cool, freshwater filament to the north. The other line, located about 8 km north of the temperature front, is believed to correspond to the velocity front between the filament and the slope water. At these fronts, wave-current interactions produced narrow bands of steep and breaking waves manifesting higher radar returns in polarimetric SAR images. In general, our AIRSAR imagery shows that the signal-to-clutter ratio of radar cross sections for the temperature front is higher than that of the velocity front. In this paper, we study the polarization and wavelength diversities of radar response of these two fronts using the P-, L-, and C-Band Polarimetric SAR data. The north-south flight path of the AIRSAR crossed the temperature front several times and provided valuable data for analysis. Three individual passes are investigated. We found that for the temperature front, the cross-pol (HV) responses are much higher than co-pol responses (VV and HH), and that P-Band HV has the highest signal to clutter ratio. For the velocity front, the ratio is the strongest in P-Band VV, and it is indistinguishable for all polarizations in C-Band. The radar cross sections for all three polarization (HH, HV, and VV) and for all three bands are modelled using an ocean wave model and a composite Bragg scattering model. In our initial investigations, the theoretical model agrees qualitatively with the AIRSAR observations.

MMS Observations of Protons and Heavy Ions Acceleration at Plasma Jet Fronts

NASA Astrophysics Data System (ADS)

Catapano, F.; Retino, A.; Zimbardo, G.; Cozzani, G.; Breuillard, H.; Le Contel, O.; Alexandrova, A.; Mirioni, L.; Cohen, I. J.; Turner, D. L.; Perri, S.; Greco, A.; Mauk, B.; Torbert, R. B.; Russell, C. T.; Khotyaintsev, Y. V.; Lindqvist, P. A.; Ergun, R.; Giles, B. L.; Fuselier, S. A.; Moore, T. E.; Burch, J.

2017-12-01

Plasma jet fronts in the Earth's magnetotail are kinetic-scale boundaries separating hot fast plasma jets, generally attributed to reconnection outflows, from colder ambient plasma. Jet fronts are typically associated with a sharp increase of the vertical component of the magnetic field Bz, an increase of the plasma temperature and a drop of plasma density. Spacecraft observations and numerical simulations indicate that jet fronts are sites of major ion acceleration. The exact acceleration mechanisms as well as the dependence of such mechanisms on ion composition are not fully understood, yet. Recent high-resolution measurements of ion distribution functions in the magnetotail allow for the first time to study the acceleration mechanisms in detail. Here, we show several examples of jet fronts and discuss ion acceleration therein. We show fronts that propagate in the mid-tail magnetotail both as isolated laminar boundaries and as multiple boundaries embedded in strong magnetic fluctuations and turbulence. We also show fronts in the near-Earth jet braking region, where they interact with the dipolar magnetic field and are significantly decelerated/diverted. Finally, we study the acceleration of different ion species (H+, He++, O+) at different types of fronts and we discuss possible different acceleration mechanisms and how they depend on the ion species.

Writing the Annual Financial Report at a Canadian Community Foundation

ERIC Educational Resources Information Center

Mittoo, Rakesh C.

2007-01-01

The corporate annual report is the chief document that is used to disseminate information about the financial performance and other issues pertaining to an organization. The report is typically divided into two sections: the front half with long narratives and photographs describing achievements, issues, and future goals; the second half…

How Obstacles Perturb Population Fronts and Alter Their Genetic Structure.

PubMed

Möbius, Wolfram; Murray, Andrew W; Nelson, David R

2015-12-01

As populations spread into new territory, environmental heterogeneities can shape the population front and genetic composition. We focus here on the effects of an important building block of heterogeneous environments, isolated obstacles. With a combination of experiments, theory, and simulation, we show how isolated obstacles both create long-lived distortions of the front shape and amplify the effect of genetic drift. A system of bacteriophage T7 spreading on a spatially heterogeneous Escherichia coli lawn serves as an experimental model system to study population expansions. Using an inkjet printer, we create well-defined replicates of the lawn and quantitatively study the population expansion of phage T7. The transient perturbations of the population front found in the experiments are well described by a model in which the front moves with constant speed. Independent of the precise details of the expansion, we show that obstacles create a kink in the front that persists over large distances and is insensitive to the details of the obstacle's shape. The small deviations between experimental findings and the predictions of the constant speed model can be understood with a more general reaction-diffusion model, which reduces to the constant speed model when the obstacle size is large compared to the front width. Using this framework, we demonstrate that frontier genotypes just grazing the side of an isolated obstacle increase in abundance, a phenomenon we call 'geometry-enhanced genetic drift', complementary to the founder effect associated with spatial bottlenecks. Bacterial range expansions around nutrient-poor barriers and stochastic simulations confirm this prediction. The effect of the obstacle on the genealogy of individuals at the front is characterized by simulations and rationalized using the constant speed model. Lastly, we consider the effect of two obstacles on front shape and genetic composition of the population illuminating the effects expected from

How Obstacles Perturb Population Fronts and Alter Their Genetic Structure

PubMed Central

Möbius, Wolfram; Murray, Andrew W.; Nelson, David R.

2015-01-01

As populations spread into new territory, environmental heterogeneities can shape the population front and genetic composition. We focus here on the effects of an important building block of heterogeneous environments, isolated obstacles. With a combination of experiments, theory, and simulation, we show how isolated obstacles both create long-lived distortions of the front shape and amplify the effect of genetic drift. A system of bacteriophage T7 spreading on a spatially heterogeneous Escherichia coli lawn serves as an experimental model system to study population expansions. Using an inkjet printer, we create well-defined replicates of the lawn and quantitatively study the population expansion of phage T7. The transient perturbations of the population front found in the experiments are well described by a model in which the front moves with constant speed. Independent of the precise details of the expansion, we show that obstacles create a kink in the front that persists over large distances and is insensitive to the details of the obstacle’s shape. The small deviations between experimental findings and the predictions of the constant speed model can be understood with a more general reaction-diffusion model, which reduces to the constant speed model when the obstacle size is large compared to the front width. Using this framework, we demonstrate that frontier genotypes just grazing the side of an isolated obstacle increase in abundance, a phenomenon we call ‘geometry-enhanced genetic drift’, complementary to the founder effect associated with spatial bottlenecks. Bacterial range expansions around nutrient-poor barriers and stochastic simulations confirm this prediction. The effect of the obstacle on the genealogy of individuals at the front is characterized by simulations and rationalized using the constant speed model. Lastly, we consider the effect of two obstacles on front shape and genetic composition of the population illuminating the effects

Stuccoed building within greenhouse complex, north and west (front) sides, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Stuccoed building within greenhouse complex, north and west (front) sides, looking south towards building no. 121 (tennis courts) across W. Pennington Ave. - Fitzsimons General Hospital, Greenhouse, West Pennington Avenue, East of Building No. 139, Aurora, Adams County, CO

Use of Glacial Fronts by Narwhals (Monodon monoceros) in West Greenland

NASA Astrophysics Data System (ADS)

Laidre, K. L.

2015-12-01

Glacial fronts in Greenland are known to be important summer habitat for narwhals (Monodon monoceros), as freshwater runoff and sediment discharge may aggregate prey at the terminus. We investigated the importance of glacial habitat characteristics in determining narwhal visitation. Narwhals (n=18) were instrumented with satellite transmitters in September 1993-1994 and 2006-2007 in Melville Bay, West Greenland. Daily narwhal locations were interpolated using a correlated random walk based on observed filtered locations and associated positional error. We also compiled a database on physical features of 41 glaciers along the northwest Greenland coast. This covered the entire coastal region with narwhal activity. Parameters included glacier ice velocity (km/yr) from radar satellite data, glacier front advance and retreat, and glacier width (km) at the ice-ocean interface derived using front position data digitized from 20-100m resolution radar image mosaics and Landsat imagery. We also quantified relative volumes and extent of glacial ice discharge, thickness of the glacial ice at the terminus (m), and water depth at the terminus (m) from gravity and airborne radar data, sediment flux from satellite-based analysis, and freshwater runoff from a regional atmospheric climate model (RACMO2.3). We quantified whale visits to glaciers at three distances (5, 7, and 10 km) and conducted proximity analyses on annual and monthly time steps. We estimated 1) narwhal presence or absence, 2) the number of 24 h periods spent at glaciers, and 3) the fraction of study animals that visited each glacier. The use of glacial habitat by narwhals expanded to the north and south between the 1990s (n=9 unique glaciers visited) and the 2000s (n=30 visited), likely due to loss of summer fast ice and later fall freeze-up trends (3.5 weeks later since 1979). We used a generalized linear mixed effects framework to quantify the glacier and fjord habitat characteristics preferred by narwhals.

Front air bag nondeployments in frontal crashes fatal to drivers or right-front passengers.

PubMed

Braver, Elisa R; McCartt, Anne T; Sherwood, Christopher P; Zuby, David S; Blanar, Laura; Scerbo, Marge

2010-04-01

Public concern has arisen about the reliability of front air bags because Fatality Analysis Reporting System (FARS) data indicate many nondeployed air bags in fatal frontal crashes. However, the accuracy of air bag deployment, the variable in question, is uncertain. This study aimed to provide more certain estimates of nondeployment incidence in fatal frontal crashes. Fatally injured passenger vehicle drivers and right-front passengers in frontal crashes were identified in two U.S. databases for calendar years 1998-2006 and model years 1994-2006: FARS, a census of police-reported fatal crashes on public roads, and National Automotive Sampling System/Crashworthiness Data System (NASS/CDS), a probability sample of tow-away crashes. NASS/CDS contains subsets of fatal crashes in FARS and collects detailed data using crash investigators. Front air bag deployment coding for front-seat occupant fatalities was compared in FARS and NASS/CDS, and case reviews were conducted. Among FARS frontal deaths with available deployment status (N = 43,169), front air bags were coded as not deployed for 18 percent of front occupants. In comparison, NASS/CDS (N = 628) reported 9 percent (weighted estimate) nondeployment among front occupants killed. Among crashes common to both databases, NASS/CDS reported deployments for 45 percent of front occupant deaths for which FARS had coded nondeployments. Detailed case reviews of NASS/CDS crashes indicated highly accurate coding for deployment status. Based on this case review, 8 percent (weighted estimate) of front occupant deaths in frontal crashes appeared to involve air bag nondeployments; 1-2 percent of front occupant deaths represented potential system failures where deployments would have been expected. Air bag deployments appeared unwarranted in most nondeployments based on crash characteristics. FARS data overstate the magnitude of the problem of air bag deployment failures; steps should be taken to improve coding. There are inherent

FRONT RIGHT OBLIQUE VIEW, SHOWING FRONT WALK/STEPS AND ROYAL PALM ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FRONT RIGHT OBLIQUE VIEW, SHOWING FRONT WALK/STEPS AND ROYAL PALM IN FOREGROUND. VIEW FACING NORTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

1. Photocopy of lithograph (from Annual Report of the Supervising ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Photocopy of lithograph (from Annual Report of the Supervising Architect to the Secretary of the Treasury for the Calender Year Ending December 31, 1888. Wahsington, D.C.: Government Printing Office, 1889. Will A. Freret, Supervising Architect) THREE-QUARTER VIEW OF FRONT ELEVATION (RIVERSIDE), FLOOR PLANS - U. S. Courthouse & Post Office, Binghamton, Broome County, NY

On the Front Line: Quantitative Virus Dynamics in Honeybee (Apis mellifera L.) Colonies along a New Expansion Front of the Parasite Varroa destructor

PubMed Central

Mondet, Fanny; de Miranda, Joachim R.; Kretzschmar, Andre; Le Conte, Yves; Mercer, Alison R.

2014-01-01

Over the past fifty years, annual honeybee (Apis mellifera) colony losses have been steadily increasing worldwide. These losses have occurred in parallel with the global spread of the honeybee parasite Varroa destructor. Indeed, Varroa mite infestations are considered to be a key explanatory factor for the widespread increase in annual honeybee colony mortality. The host-parasite relationship between honeybees and Varroa is complicated by the mite's close association with a range of honeybee viral pathogens. The 10-year history of the expanding front of Varroa infestation in New Zealand offered a rare opportunity to assess the dynamic quantitative and qualitative changes in honeybee viral landscapes in response to the arrival, spread and level of Varroa infestation. We studied the impact of de novo infestation of bee colonies by Varroa on the prevalence and titres of seven well-characterised honeybee viruses in both bees and mites, using a large-scale molecular ecology approach. We also examined the effect of the number of years since Varroa arrival on honeybee and mite viral titres. The dynamic shifts in the viral titres of black queen cell virus and Kashmir bee virus mirrored the patterns of change in Varroa infestation rates along the Varroa expansion front. The deformed wing virus (DWV) titres in bees continued to increase with Varroa infestation history, despite dropping infestation rates, which could be linked to increasing DWV titres in the mites. This suggests that the DWV titres in mites, perhaps boosted by virus replication, may be a major factor in maintaining the DWV epidemic after initial establishment. Both positive and negative associations were identified for several pairs of viruses, in response to the arrival of Varroa. These findings provide important new insights into the role of the parasitic mite Varroa destructor in influencing the viral landscape that affects honeybee colonies. PMID:25144447

Advances in Light-Front QCD: Supersymmetric Properties of Hadron Physics from Light-Front Holography and Superconformal Algebra

NASA Astrophysics Data System (ADS)

Brodsky, Stanley J.

2017-05-01

A remarkable feature of QCD is that the mass scale κ which controls color confinement and light-quark hadron mass scales does not appear explicitly in the QCD Lagrangian. However, de Alfaro, Fubini, and Furlan have shown that a mass scale can appear in the equations of motion without affecting the conformal invariance of the action if one adds a term to the Hamiltonian proportional to the dilatation operator or the special conformal operator. If one applies the same procedure to the light-front Hamiltonian, it leads uniquely to a confinement potential κ ^4 ζ ^2 for mesons, where ζ ^2 is the LF radial variable conjugate to the q \\bar{q} invariant mass. The same result, including spin terms, is obtained using light-front holography—the duality between the front form and AdS_5, the space of isometries of the conformal group—if one modifies the action of AdS_5 by the dilaton e^{κ ^2 z^2} in the fifth dimension z. When one generalizes this procedure using superconformal algebra, the resulting light-front eigensolutions predict a unified Regge spectroscopy of meson, baryon, and tetraquarks, including remarkable supersymmetric relations between the masses of mesons and baryons of the same parity. One also predicts observables such as hadron structure functions, transverse momentum distributions, and the distribution amplitudes defined from the hadronic light-front wavefunctions. The mass scale κ underlying confinement and hadron masses can be connected to the parameter Λ _{\\overline{MS}} in the QCD running coupling by matching the nonperturbative dynamics to the perturbative QCD regime. The result is an effective coupling α _s(Q^2) defined at all momenta. The matching of the high and low momentum transfer regimes determines a scale Q_0 which sets the interface between perturbative and nonperturbative hadron dynamics. The use of Q_0 to resolve the factorization scale uncertainty for structure functions and distribution amplitudes, in combination with the

Advances in Light-Front QCD: Supersymmetric Properties of Hadron Physics from Light-Front Holography and Superconformal Algebra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodsky, Stanley J.

A remarkable feature of QCD is that the mass scalemore » $k$ which controls color confinement and light-quark hadron mass scales does not appear explicitly in the QCD Lagrangian. However, de Alfaro, Fubini, and Furlan have shown that a mass scale can appear in the equations of motion without affecting the conformal invariance of the action if one adds a term to the Hamiltonian proportional to the dilatation operator or the special conformal operator. If one applies the same procedure to the light-front Hamiltonian, it leads uniquely to a confinement potential κ 4ζ 2 for mesons, where ζ 2 is the LF radial variable conjugate to the $$q\\bar{q}$$ invariant mass. The same result, including spin terms, is obtained using light-front holography$-$the duality between the front form and AdS 5, the space of isometries of the conformal group$-$if one modifies the action of AdS 5 by the dilaton e $κ^2z^2$ in the fifth dimension z. When one generalizes this procedure using superconformal algebra, the resulting light-front eigensolutions predict a unified Regge spectroscopy of meson, baryon, and tetraquarks, including remarkable supersymmetric relations between the masses of mesons and baryons of the same parity. One also predicts observables such as hadron structure functions, transverse momentum distributions, and the distribution amplitudes defined from the hadronic light-front wavefunctions. The mass scale κκ underlying confinement and hadron masses can be connected to the parameter Λ $$\\overline{MS}$$ in the QCD running coupling by matching the nonperturbative dynamics to the perturbative QCD regime. The result is an effective coupling α s (Q 2) defined at all momenta. The matching of the high and low momentum transfer regimes determines a scale Q 0 which sets the interface between perturbative and nonperturbative hadron dynamics. The use of Q 0 to resolve the factorization scale uncertainty for structure functions and distribution amplitudes, in combination with

Advances in Light-Front QCD: Supersymmetric Properties of Hadron Physics from Light-Front Holography and Superconformal Algebra

DOE PAGES

Brodsky, Stanley J.

2017-04-19

A remarkable feature of QCD is that the mass scalemore » $k$ which controls color confinement and light-quark hadron mass scales does not appear explicitly in the QCD Lagrangian. However, de Alfaro, Fubini, and Furlan have shown that a mass scale can appear in the equations of motion without affecting the conformal invariance of the action if one adds a term to the Hamiltonian proportional to the dilatation operator or the special conformal operator. If one applies the same procedure to the light-front Hamiltonian, it leads uniquely to a confinement potential κ 4ζ 2 for mesons, where ζ 2 is the LF radial variable conjugate to the $$q\\bar{q}$$ invariant mass. The same result, including spin terms, is obtained using light-front holography$-$the duality between the front form and AdS 5, the space of isometries of the conformal group$-$if one modifies the action of AdS 5 by the dilaton e $κ^2z^2$ in the fifth dimension z. When one generalizes this procedure using superconformal algebra, the resulting light-front eigensolutions predict a unified Regge spectroscopy of meson, baryon, and tetraquarks, including remarkable supersymmetric relations between the masses of mesons and baryons of the same parity. One also predicts observables such as hadron structure functions, transverse momentum distributions, and the distribution amplitudes defined from the hadronic light-front wavefunctions. The mass scale κκ underlying confinement and hadron masses can be connected to the parameter Λ $$\\overline{MS}$$ in the QCD running coupling by matching the nonperturbative dynamics to the perturbative QCD regime. The result is an effective coupling α s (Q 2) defined at all momenta. The matching of the high and low momentum transfer regimes determines a scale Q 0 which sets the interface between perturbative and nonperturbative hadron dynamics. The use of Q 0 to resolve the factorization scale uncertainty for structure functions and distribution amplitudes, in combination with

1. SOUTH FRONT OF TURBINE BUILDING BUILDING L1 (LEFT) AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. SOUTH FRONT OF TURBINE BUILDING BUILDING L1 (LEFT) AND OF L.P. BOILER ROOM BUILDING L2 (RIGHT) - Portland General Electric Company, Turbine Building, 1841 Southeast Water Street, Portland, Multnomah County, OR

Generalizing the flash technique in the front-face configuration to measure the thermal diffusivity of semitransparent solids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pech-May, Nelson Wilbur; Department of Applied Physics, CINVESTAV Unidad Mérida, carretera Antigua a Progreso km6, A.P. 73 Cordemex, Mérida Yucatán 97310, México; Mendioroz, Arantza

2014-10-15

In this work, we have extended the front-face flash method to retrieve simultaneously the thermal diffusivity and the optical absorption coefficient of semitransparent plates. A complete theoretical model that allows calculating the front surface temperature rise of the sample has been developed. It takes into consideration additional effects, such as multiple reflections of the heating light beam inside the sample, heat losses by convection and radiation, transparency of the sample to infrared wavelengths, and heating pulse duration. Measurements performed on calibrated solids, covering a wide range of absorption coefficients (from transparent to opaque) and thermal diffusivities, validate the proposed method.

Relativistic runaway ionization fronts.

PubMed

Luque, A

2014-01-31

We investigate the first example of self-consistent impact ionization fronts propagating at relativistic speeds and involving interacting, high-energy electrons. These fronts, which we name relativistic runaway ionization fronts, show remarkable features such as a bulk speed within less than one percent of the speed of light and the stochastic selection of high-energy electrons for further acceleration, which leads to a power-law distribution of particle energies. A simplified model explains this selection in terms of the overrun of Coulomb-scattered electrons. Appearing as the electromagnetic interaction between electrons saturates the exponential growth of a relativistic runaway electron avalanche, relativistic runaway ionization fronts may occur in conjunction with terrestrial gamma-ray flashes and thus explain recent observations of long, power-law tails in the terrestrial gamma-ray flash energy spectrum.

Entrance on the front of the building with canopy extending ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Entrance on the front of the building with canopy extending toward the right - Fitzsimons General Hospital, Bachelor Officers' Quarters/Officers' Club, West Harlowe Avenue, South side, 200 feet West of intersection of West Harlow Avenue & South First Street, Aurora, Adams County, CO

24 CFR 290.27 - Up-front grants and loans.

Code of Federal Regulations, 2014 CFR

2014-04-01

... URBAN DEVELOPMENT HUD-OWNED PROPERTIES DISPOSITION OF MULTIFAMILY PROJECTS AND SALE OF HUD-HELD MULTIFAMILY MORTGAGES Disposition of Multifamily Projects § 290.27 Up-front grants and loans. (a) General. HUD... development costs as part of the disposition of a multifamily housing project that is HUD-owned, upon making a...

24 CFR 290.27 - Up-front grants and loans.

Code of Federal Regulations, 2012 CFR

2012-04-01

... URBAN DEVELOPMENT HUD-OWNED PROPERTIES DISPOSITION OF MULTIFAMILY PROJECTS AND SALE OF HUD-HELD MULTIFAMILY MORTGAGES Disposition of Multifamily Projects § 290.27 Up-front grants and loans. (a) General. HUD... development costs as part of the disposition of a multifamily housing project that is HUD-owned, upon making a...

Planar microlens with front-face angle: design, fabrication, and characterization

NASA Astrophysics Data System (ADS)

Al Hafiz, Md. Abdullah; Michael, Aron; Kwok, Chee-Yee

2016-07-01

This paper studies the effect of microlens front-face angle on the performance of an optical system consisting of a planar-graded refractive index (GRIN) lens pair facing each other separated by a free-space region. The planar silica microlens pairs are designed to facilitate low-loss optical signal propagation in the free-space region between the opposing optical waveguides. The planar lens is fabricated from a 38-μm-thick fluorine-doped silica layer on a silicon substrate. It has a parabolic refractive index profile in the vertical direction, which is achieved by controlled fluorine incorporation in the silica film to collimate the optical beam in the vertical direction. Horizontal beam collimation is achieved by incorporating a horizontal curvature at the front face of the lens defined by deep oxide etch. A generalized 3×3 ABCDGH transformation matrix method has been derived to compute the coupling efficiency of such microlens pairs to take front-face angles that may be present due to fabrication variations or limitations and possible input/output optical fiber offset/tilt into considerations. Pairs of such planar GRIN lens with various free-space propagation distances between them ranging from 75 to 2500 μm and with front-face angles of 1.5 deg, 2 deg, and 4 deg have been fabricated and characterized. Beam propagation method simulations have been carried out to substantiate the theoretical and experimental results. The results indicate that the optical loss is reasonably low up to 1.5 deg of front-face angles and increases significantly with further increase in the front-face angle. Analysis shows that for a given system with specific microlens front-face angle, the optical loss can be significantly reduced by properly compensating the vertical position of the input and output fibers.

Highly Efficient Wave-Front Reshaping of Surface Waves with Dielectric Metawalls

NASA Astrophysics Data System (ADS)

Dong, Shaohua; Zhang, Yu; Guo, Huijie; Duan, Jingwen; Guan, Fuxin; He, Qiong; Zhao, Haibin; Zhou, Lei; Sun, Shulin

2018-01-01

Controlling the wave fronts of surface waves (including surface-plamon polaritons and their equivalent counterparts) at will is highly important in photonics research, but the available mechanisms suffer from the issues of low efficiency, bulky size, and/or limited functionalities. Inspired by recent studies of metasurfaces that can freely control the wave fronts of propagating waves, we propose to use metawalls placed on a plasmonic surface to efficiently reshape the wave fronts of incident surface waves (SWs). Here, the metawall is constructed by specifically designed meta-atoms that can reflect SWs with desired phases and nearly unit amplitudes. As a proof of concept, we design and fabricate a metawall in the microwave regime (around 12 GHz) that can anomalously reflect the SWs following the generalized Snell's law with high efficiency (approximately 70%). Our results, in excellent agreement with full-wave simulations, provide an alternative yet efficient way to control the wave fronts of SWs in different frequency domains. We finally employ full-wave simulations to demonstrate a surface-plasmon-polariton focusing effect at telecom wavelength based on our scheme.

Consumer preferences for front-of-pack calories labelling.

PubMed

van Kleef, Ellen; van Trijp, Hans; Paeps, Frederic; Fernández-Celemín, Laura

2008-02-01

In light of the emerging obesity pandemic, front-of-pack calories labels may be an important tool to assist consumers in making informed healthier food choices. However, there is little prior research to guide key decisions on whether caloric content should be expressed in absolute terms or relative to recommended daily intake, whether it should be expressed in per serving or per 100 g and whether the information should be further brought alive for consumers in terms of what the extra calorie intake implies in relation to activity levels. The present study aimed at providing more insight into consumers' appreciation of front-of-pack labelling of caloric content of food products and their specific preferences for alternative execution formats for such information in Europe. For this purpose, eight executions of front-of-pack calorie flags were designed and their appeal and information value were extensively discussed with consumers through qualitative research in four different countries (Germany, The Netherlands, France and the UK). The results show that calories are well-understood and that participants were generally positive about front-of-pack flags, particularly when flags are uniform across products. The most liked flags are the simpler flags depicting only the number of calories per serving or per 100 g, while more complex flags including references to daily needs or exercise and the flag including a phrase referring to balanced lifestyle were least preferred. Some relevant differences between countries were observed. Although participants seem to be familiar with the notion of calories, they do not seem to fully understand how to apply them. From the results, managerial implications for the design and implementation of front-of-pack calorie labelling as well as important directions for future research are discussed.

Consumer preferences for front-of-pack calories labelling

PubMed Central

van Kleef, Ellen; van Trijp, Hans; Paeps, Frederic; Fernández-Celemín, Laura

2008-01-01

Objective In light of the emerging obesity pandemic, front-of-pack calories labels may be an important tool to assist consumers in making informed healthier food choices. However, there is little prior research to guide key decisions on whether caloric content should be expressed in absolute terms or relative to recommended daily intake, whether it should be expressed in per serving or per 100 g and whether the information should be further brought alive for consumers in terms of what the extra calorie intake implies in relation to activity levels. The present study aimed at providing more insight into consumers’ appreciation of front-of-pack labelling of caloric content of food products and their specific preferences for alternative execution formats for such information in Europe. Design For this purpose, eight executions of front-of-pack calorie flags were designed and their appeal and information value were extensively discussed with consumers through qualitative research in four different countries (Germany, The Netherlands, France and the UK). Results The results show that calories are well-understood and that participants were generally positive about front-of-pack flags, particularly when flags are uniform across products. The most liked flags are the simpler flags depicting only the number of calories per serving or per 100 g, while more complex flags including references to daily needs or exercise and the flag including a phrase referring to balanced lifestyle were least preferred. Some relevant differences between countries were observed. Although participants seem to be familiar with the notion of calories, they do not seem to fully understand how to apply them. Conclusion From the results, managerial implications for the design and implementation of front-of-pack calorie labelling as well as important directions for future research are discussed. PMID:17601362

Implementation of a gust front head collapse scheme in the WRF numerical model

NASA Astrophysics Data System (ADS)

Lompar, Miloš; Ćurić, Mladjen; Romanic, Djordje

2018-05-01

Gust fronts are thunderstorm-related phenomena usually associated with severe winds which are of great importance in theoretical meteorology, weather forecasting, cloud dynamics and precipitation, and wind engineering. An important feature of gust fronts demonstrated through both theoretical and observational studies is the periodic collapse and rebuild of the gust front head. This cyclic behavior of gust fronts results in periodic forcing of vertical velocity ahead of the parent thunderstorm, which consequently influences the storm dynamics and microphysics. This paper introduces the first gust front pulsation parameterization scheme in the WRF-ARW model (Weather Research and Forecasting-Advanced Research WRF). The influence of this new scheme on model performances is tested through investigation of the characteristics of an idealized supercell cumulonimbus cloud, as well as studying a real case of thunderstorms above the United Arab Emirates. In the ideal case, WRF with the gust front scheme produced more precipitation and showed different time evolution of mixing ratios of cloud water and rain, whereas the mixing ratios of ice and graupel are almost unchanged when compared to the default WRF run without the parameterization of gust front pulsation. The included parameterization did not disturb the general characteristics of thunderstorm cloud, such as the location of updraft and downdrafts, and the overall shape of the cloud. New cloud cells in front of the parent thunderstorm are also evident in both ideal and real cases due to the included forcing of vertical velocity caused by the periodic collapse of the gust front head. Despite some differences between the two WRF simulations and satellite observations, the inclusion of the gust front parameterization scheme produced more cumuliform clouds and seem to match better with real observations. Both WRF simulations gave poor results when it comes to matching the maximum composite radar reflectivity from radar

Frequency-dependent selection at rough expanding fronts

NASA Astrophysics Data System (ADS)

Kuhr, Jan-Timm; Stark, Holger

2015-10-01

Microbial colonies are experimental model systems for studying the colonization of new territory by biological species through range expansion. We study a generalization of the two-species Eden model, which incorporates local frequency-dependent selection, in order to analyze how social interactions between two species influence surface roughness of growing microbial colonies. The model includes several classical scenarios from game theory. We then concentrate on an expanding public goods game, where either cooperators or defectors take over the front depending on the system parameters. We analyze in detail the critical behavior of the nonequilibrium phase transition between global cooperation and defection and thereby identify a new universality class of phase transitions dealing with absorbing states. At the transition, the number of boundaries separating sectors decays with a novel power law in time and their superdiffusive motion crosses over from Eden scaling to a nearly ballistic regime. In parallel, the width of the front initially obeys Eden roughening and, at later times, passes over to selective roughening.

Density profiles around A+B→C reaction-diffusion fronts in partially miscible systems: A general classification.

PubMed

Loodts, V; Trevelyan, P M J; Rongy, L; De Wit, A

2016-10-01

Various spatial density profiles can develop in partially miscible stratifications when a phase A dissolves with a finite solubility into a host phase containing a dissolved reactant B. We investigate theoretically the impact of an A+B→C reaction on such density profiles in the host phase and classify them in a parameter space spanned by the ratios of relative contributions to density and diffusion coefficients of the chemical species. While the density profile is either monotonically increasing or decreasing in the nonreactive case, reactions combined with differential diffusivity can create eight different types of density profiles featuring up to two extrema in density, at the reaction front or below it. We use this framework to predict various possible hydrodynamic instability scenarios inducing buoyancy-driven convection around such reaction fronts when they propagate parallel to the gravity field.

Ground water occurrence and contributions to streamflow in an alpine catchment, Colorado Front Range

USGS Publications Warehouse

Clow, D.W.; Schrott, L.; Webb, R.; Campbell, D.H.; Torizzo, A.O.; Dornblaser, M.

2003-01-01

Ground water occurrence, movement, and its contribution to streamflow were investigated in Loch Vale, an alpine catchment in the Front Range of the Colorado Rocky Mountains. Hydrogeomorphologic mapping, seismic refraction measurements, and porosity and permeability estimates indicate that talus slopes are the primary ground water reservoir, with a maximum storage capacity that is equal to, or greater than, total annual discharge from the basin (5.4 ± 0.8 × 106 m3). Although snowmelt and glacial melt provide the majority of annual water flux to the basin, tracer tests and gauging along a stream transect indicate that ground water flowing from talus can account for ≥75% of streamflow during storms and the winter base flow period. The discharge response of talus springs to storms and snowmelt reflects rapid transmittal of water through coarse debris at the talus surface and slower release of water from finer-grained sediments at depth.Ice stored in permafrost (including rock glaciers) is the second largest ground water reservoir in Loch Vale; it represents a significant, but seldom recognized, ground water reservoir in alpine terrain. Mean annual air temperatures are sufficiently cold to support permafrost above 3460 m; however, air temperatures have increased 1.1° to 1.4°C since the early 1990s, consistent with long-term (1976–2000) increases in air temperature measured at other high-elevation sites in the Front Range, European Alps, and Peruvian Andes. If other climatic factors remain constant, the increase in air temperatures at Loch Vale is sufficient to increase the lower elevational limit of permafrost by 150 to 190 m. Although this could cause a short-term increase in streamflow, it may ultimately result in decreased flow in the future.

Multiphysical FE-analysis of a front-end bending phenomenon in a hot strip mill

NASA Astrophysics Data System (ADS)

Ilmola, Joonas; Seppälä, Oskari; Leinonen, Olli; Pohjonen, Aarne; Larkiola, Jari; Jokisaari, Juha; Putaansuu, Eero

2018-05-01

In hot steel rolling processes, a slab is generally rolled to a transfer bar in a roughing process and to a strip in a hot strip rolling process. Over several rolling passes the front-end may bend upward or downward due to asymmetrical rolling conditions causing entry problems in the next rolling pass. Many different factors may affect the front-end bending phenomenon and are very challenging to measure. Thus, a customized finite element model is designed and built to simulate the front-end bending phenomenon in a hot strip rolling process. To simulate the functioning of the hot strip mill precisely, automated controlling logic of the mill must be considered. In this paper we studied the effect of roll bite friction conditions and amount of reduction on the front-end bending phenomenon in a hot strip rolling process.

A beam-splitter-type 3-D endoscope for front view and front-diagonal view images.

PubMed

Kamiuchi, Hiroki; Masamune, Ken; Kuwana, Kenta; Dohi, Takeyoshi; Kim, Keri; Yamashita, Hiromasa; Chiba, Toshio

2013-01-01

In endoscopic surgery, surgeons must manipulate an endoscope inside the body cavity to observe a large field-of-view while estimating the distance between surgical instruments and the affected area by reference to the size or motion of the surgical instruments in 2-D endoscopic images on a monitor. Therefore, there is a risk of the endoscope or surgical instruments physically damaging body tissues. To overcome this problem, we developed a Ø7- mm 3-D endoscope that can switch between providing front and front-diagonal view 3-D images by simply rotating its sleeves. This 3-D endoscope consists of a conventional 3-D endoscope and an outer and inner sleeve with a beam splitter and polarization plates. The beam splitter was used for visualizing both the front and front-diagonal view and was set at 25° to the outer sleeve's distal end in order to eliminate a blind spot common to both views. Polarization plates were used to avoid overlap of the two views. We measured signal-to-noise ratio (SNR), sharpness, chromatic aberration (CA), and viewing angle of this 3-D endoscope and evaluated its feasibility in vivo. Compared to the conventional 3-D endoscope, SNR and sharpness of this 3-D endoscope decreased by 20 and 7 %, respectively. No significant difference was found in CA. The viewing angle for both the front and front-diagonal views was about 50°. In the in vivo experiment, this 3-D endoscope can provide clear 3-D images of both views by simply rotating its inner sleeve. The developed 3-D endoscope can provide the front and front-diagonal view by simply rotating the inner sleeve, therefore the risk of damage to fragile body tissues can be significantly decreased.

Atmospheric fronts in current and future climates

NASA Astrophysics Data System (ADS)

Catto, J. L.; Nicholls, N.; Jakob, C.; Shelton, K. L.

2014-11-01

Atmospheric fronts are important for the day-to-day variability of weather in the midlatitudes. It is therefore vital to know how their distribution and frequency will change in a projected warmer climate. Here we apply an objective front identification method, based on a thermal front parameter, to 6-hourly data from models participating in Coupled Model Intercomparison Project phase 5. The historical simulations are evaluated against ERA-Interim and found to produce a similar frequency of fronts and with similar front strength. The models show some biases in the location of the front frequency maxima. Future changes are estimated using the high emissions scenario simulations (Representative Concentration Pathway 8.5). Projections show an overall decrease in front frequency in the Northern Hemisphere, with a poleward shift of the maxima of front frequency and a strong decrease at high latitudes where the temperature gradient is decreased. The Southern Hemisphere shows a poleward shift of the frequency maximum, consistent with previous storm track studies.

Light-front spin-dependent spectral function and nucleon momentum distributions for a three-body system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Del Dotto, Alessio; Pace, Emanuele; Salme, Giovanni

Poincare covariant definitions for the spin-dependent spectral function and for the momentum distributions within the light-front Hamiltonian dynamics are proposed for a three-fermion bound system, starting from the light-front wave function of the system. The adopted approach is based on the Bakamjian–Thomas construction of the Poincaré generators, which allows one to easily import the familiar and wide knowledge on the nuclear interaction into a light-front framework. The proposed formalism can find useful applications in refined nuclear calculations, such as those needed for evaluating the European Muon Collaboration effect or the semi-inclusive deep inelastic cross sections with polarized nuclear targets, sincemore » remarkably the light-front unpolarized momentum distribution by definition fulfills both normalization and momentum sum rules. As a result, also shown is a straightforward generalization of the definition of the light-front spectral function to an A-nucleon system.« less

Light-front spin-dependent spectral function and nucleon momentum distributions for a three-body system

DOE PAGES

Del Dotto, Alessio; Pace, Emanuele; Salme, Giovanni; ...

2017-01-10

Poincare covariant definitions for the spin-dependent spectral function and for the momentum distributions within the light-front Hamiltonian dynamics are proposed for a three-fermion bound system, starting from the light-front wave function of the system. The adopted approach is based on the Bakamjian–Thomas construction of the Poincaré generators, which allows one to easily import the familiar and wide knowledge on the nuclear interaction into a light-front framework. The proposed formalism can find useful applications in refined nuclear calculations, such as those needed for evaluating the European Muon Collaboration effect or the semi-inclusive deep inelastic cross sections with polarized nuclear targets, sincemore » remarkably the light-front unpolarized momentum distribution by definition fulfills both normalization and momentum sum rules. As a result, also shown is a straightforward generalization of the definition of the light-front spectral function to an A-nucleon system.« less

Fluctuation-controlled front propagation

NASA Astrophysics Data System (ADS)

Ridgway, Douglas Thacher

1997-09-01

A number of fundamental pattern-forming systems are controlled by fluctuations at the front. These problems involve the interaction of an infinite dimensional probability distribution with a strongly nonlinear, spatially extended pattern-forming system. We have examined fluctuation-controlled growth in the context of the specific problems of diffusion-limited growth and biological evolution. Mean field theory of diffusion-limited growth exhibits a finite time singularity. Near the leading edge of a diffusion-limited front, this leads to acceleration and blowup. This may be resolved, in an ad hoc manner, by introducing a cutoff below which growth is weakened or eliminated (8). This model, referred to as the BLT model, captures a number of qualitative features of global pattern formation in diffusion-limited aggregation: contours of the mean field match contours of averaged particle density in simulation, and the modified mean field theory can form dendritic features not possible in the naive mean field theory. The morphology transition between dendritic and non-dendritic global patterns requires that BLT fronts have a Mullins-Sekerka instability of the wavefront shape, in order to form concave patterns. We compute the stability of BLT fronts numerically, and compare the results to fronts without a cutoff. A significant morphological instability of the BLT fronts exists, with a dominant wavenumber on the scale of the front width. For standard mean field fronts, no instability is found. The naive and ad hoc mean field theories are continuum-deterministic models intended to capture the behavior of a discrete stochastic system. A transformation which maps discrete systems into a continuum model with a singular multiplicative noise is known, however numerical simulations of the continuum stochastic system often give mean field behavior instead of the critical behavior of the discrete system. We have found a new interpretation of the singular noise, based on maintaining

Body composition and weight dynamics of wintering greater white-fronted geese

USGS Publications Warehouse

Ely, Craig R.; Raveling, Dennis G.

1989-01-01

Adult greater white-fronted geese (Anser albifrons frontalis) wintering in southern Oregon and California increased or maintained body weight in autumn, lost weight from autumn through winter, and rapidly increased in weight before spring migration in late April. We documented significant annual differences in body weights for both sexes. We related seasonal changes in body weight to changes in lipid levels, which were lowest (12-13% of wet wt in M and F) in mid-March and highest in late April (24% in F). Greater white-fronted geese maintained lipid levels during winter similar to those reported for large subspecies of Canada geese (Branta canadensis), and greater than those reported for small subspecies of Canada geese and other small species of geese. Protein content of carcasses varied significantly in females; i.e., lowest in early October and highest in late October and late April. Differences among species in patterns of weight change and body composition during winter seem to be related to social organization, body size, food type, and foraging behavior. Females left spring staging areas weighing relatively less than most other species of geese and may have benefited from foraging opportunities on the nesting grounds.

The thermodynamic and dynamical features of double front structures during 21 31 July 1998 in China

NASA Astrophysics Data System (ADS)

Zhou, Yushu; Deng, Guo; Lei, Ting; Ju, Jianhua

2005-11-01

The daily 1° × 1° data of the Aviation (AVN) model, the black body temperature (TBB) data of cloud top, and cloud images by geostationary meteorological satellite (GMS) are used to identify a dew-point front near the periphery of the western Pacific subtropical high (WPSH). The results clearly demonstrate the existence of the dew-point front, and its thermodynamic and dynamic structural characteristics are analyzed in detail. The dew-point front is a transitional belt between the moist southwest monsoon flow and the dry adiabatic sinking flow near the WPSH, manifested by a large horizontal moisture gradient in the mid-lower troposphere and conjugated with the mei-yu front to form a predominant double-front structure associated with intense rainfall in the mei-yu period. The mei-yu front is located between 30° and 35°N, vertically extends from the ground level to the upper level and shifts northward. The dew-point front is to the south of the mei-yu front and lies up against the periphery of the WPSH. Generally, it is located between 850 hPa and 500 hPa. On the dew-point front side, the southwesterly prevails at the lower level and the northeasterly at the upper level; this wind distribution is different from that on the mei-yu front side. Vertical ascending motion exists between the two fronts, and there are descending motions on the north side of the mei-yu front and on the south side of the dew-point front, which form a secondary circulation. The dynamics of the double fronts also have some interesting features. At the lower level, positive vertical vorticity and obvious convergence between the two fronts are clearly identified. At the mid-lower level, negative local change of the divergence (corresponding to increasing convergence) is often embedded in the two fronts or against the mei-yu front. Most cloud clusters occur between the two fronts and propagate down stream in a wave-like manner.

A Regional Survey of River-plume Sedimentation on the Mississippi River Delta Front

NASA Astrophysics Data System (ADS)

Courtois, A. J.; Bentley, S. J.; Xu, K.; Georgiou, I. Y.; Maloney, J. M.; Miner, M. D.; Chaytor, J. D.; Smith, J.

2017-12-01

Many studies of the Mississippi River and Delta (MRD) have shown historic declines in sediment load reaching the main river distributaries over the last few decades. Recent studies also reported that 50% of the suspended load during floods is sequestered within the delta. While the impact of declining sediment load on wetland loss is well documented, submarine sedimentary processes on the delta front during this recent period of declining sediment load are understudied. To better understand modern sediment dispersal and deposition across the Mississippi River Delta Front, 31 multicores were collected in June 2017 from locations extending offshore from Southwest Pass, South Pass, and Pass a Loutre (the main river outlets) in water depths of 25-280 m. Core locations were selected based on multibeam bathymetry and morphology collected by the USGS in May 2017; the timing of collection coincided with the end of annual peak discharge on the Mississippi River. This multi-agency survey is the first to study delta-front sedimentary processes regionally with such a wide suite of tools. Target locations for coring included the dominant depositional environments: mudflow lobes, gullies, and undisturbed prodelta. Cores were subsampled at 2 cm intervals and analyzed for Beryllium-7 activity via gamma spectrometry; in such settings, Be-7 can be used as a tracer of sediment recently delivered from fluvial origin. Results indicate a general trend of declining Be-7 activity with increasing distance from source, and in deeper water. Inshore samples near Southwest Pass show the deepest penetration depth of Be-7 into the sediment (24-26 cm), which is a preliminary indicator of rapid seasonal sedimentation. Nearshore samples from South Pass exhibited similar Be-7 penetration depths, with results near Pass a Loutre to 14-16 cm depth. Be-7 remains detectable to 2 cm in water 206 m deep, approximately 20 km from South Pass. Sediment dispersal remains impressive offshore from all three

Front and pulse solutions for the complex Ginzburg-Landau equation with higher-order terms.

PubMed

Tian, Huiping; Li, Zhonghao; Tian, Jinping; Zhou, Guosheng

2002-12-01

We investigate one-dimensional complex Ginzburg-Landau equation with higher-order terms and discuss their influences on the multiplicity of solutions. An exact analytic front solution is presented. By stability analysis for the original partial differential equation, we derive its necessary stability condition for amplitude perturbations. This condition together with the exact front solution determine the region of parameter space where the uniformly translating front solution can exist. In addition, stable pulses, chaotic pulses, and attenuation pulses appear generally if the parameters are out of the range. Finally, applying these analysis into the optical transmission system numerically we find that the stable transmission of optical pulses can be achieved if the parameters are appropriately chosen.

Reaction front barriers in time aperiodic fluid flows

NASA Astrophysics Data System (ADS)

Locke, Rory; Mitchell, Kevin

2016-11-01

Many chemical and biological systems can be characterized by the propagation of a front that separates different phases or species. One approach to formalizing a general theory is to apply frameworks developed in nonlinear dynamics. It has been shown that invariant manifolds form barriers to passive transport in time-dependent or time-periodic fluid flows. More recently, analogous manifolds termed burning- invariant-manifolds (BIMs), have been shown to form one-sided barriers to reaction fronts in advection-reaction-diffusion (ARD) systems. To model more realistic time-aperiodic systems, recent theoretical work has suggested that similar one-sided barriers, termed burning Lagrangian coherent structures (bLCSs), exist for fluid velocity data prescribed over a finite time interval. In this presentation, we use a stochastic "wind" to generate time dependence in a double-vortex channel flow and demonstrate the (locally) most attracting or repelling curves are the bLCSs.

[The general practitioners in front of reforms: the reactions of the sample group of liberal physicians of the region PACA].

PubMed

Videau, Yann; Ventelou, Bruno; Combes, Jean-Baptiste; Verger, Pierre; Paraponaris, Alain

2007-05-01

The general practitioners in front of reforms: the reactions of the sample group of liberal physicians of the region PACA This article intends to analyse the opinion of general practioners (GPs) about the two laws of July 2004, relating to the health insurance reform and to public health planning. We used a panel data sample of 528 GPs practising in Provence Alpes Côte d'Azur in order to analyse the determinants of physicians' adherence to the reform, using multinomial logistic regression models. The results show that GPs do not seem to be fully convinced by this reform (45% agree with it, whereas 48% don't): this mistrustful opinion is more marked for young physicians and appears little correlated with their practices. 75% of the GPs are favourable to the Personal Medical File (Dossier Médical Personnel in french) and 76% estimate that they should draw a better attention to the public health dimension of their practice. Two barriers concerning GPs' adherence to the < preferred doctor > reform (réforme du < médecin traitant >) seem relevant: the burden of administrative tasks and the disadvantage of young physicians who have not already fixed their own clientele.

Condensation Front Migration in a Protoplanetary Nebula

NASA Technical Reports Server (NTRS)

Davis, Sanford S.

2004-01-01

Condensation front dynamics are investigated in the mid-solar nebula region. A quasi-steady model of the evolving nebula is combined with equilibrium vapor pressure curves to determine evolutionary condensation fronts for selected species. These fronts are found to migrate inwards from the far-nebula to final positions during a period of 10(exp 7) years. The physical process governing this movement is a combination of local viscous heating and luminescent heating from the central star. Two luminescent heating models are used and their effects on the ultimate radial position of the condensation front are discussed. At first the fronts move much faster than the nebular accretion velocity, but after a time the accreting gas and dust overtakes the slowing condensation front.

Front blind spot crashes in Hong Kong.

PubMed

Cheng, Yuk Ki; Wong, Koon Hung; Tao, Chi Hang; Tam, Cheok Ning; Tam, Yiu Yan; Tsang, Cheuk Nam

2016-09-01

In 2012-2014, our laboratory had investigated a total of 9 suspected front blind spot crashes, in which the medium and heavy goods vehicles pulled away from rest and rolled over the pedestrians, who were crossing immediately in front of the vehicles. The drivers alleged that they did not see any pedestrians through the windscreens or the front blind spot mirrors. Forensic assessment of the goods vehicles revealed the existence of front blind spot zones in 3 out of these 9 accident vehicles, which were attributed to the poor mirror adjustments or even the absence of a front blind spot mirror altogether. In view of this, a small survey was devised involving 20 randomly selected volunteers and their goods vehicles and 5 out of these vehicles had blind spots at the front. Additionally, a short questionnaire was conducted on these 20 professional lorry drivers and it was shown that most of them were not aware of the hazards of blind spots immediately in front of their vehicles, and many did not use the front blind spot mirrors properly. A simple procedure for quick measurements of the coverage of front blind spot mirrors using a coloured plastic mat with dimensional grids was also introduced and described in this paper. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Energy conversion at dipolarization fronts

NASA Astrophysics Data System (ADS)

Khotyaintsev, Yu. V.; Divin, A.; Vaivads, A.; André, M.; Markidis, S.

2017-02-01

We use multispacecraft observations by Cluster in the Earth's magnetotail and 3-D particle-in-cell simulations to investigate conversion of electromagnetic energy at the front of a fast plasma jet. We find that the major energy conversion is happening in the Earth (laboratory) frame, where the electromagnetic energy is being transferred from the electromagnetic field to particles. This process operates in a region with size of the order several ion inertial lengths across the jet front, and the primary contribution to E·j is coming from the motional electric field and the ion current. In the frame of the front we find fluctuating energy conversion with localized loads and generators at sub-ion scales which are primarily related to the lower hybrid drift instability excited at the front; however, these provide relatively small net energy conversion.

Nonperturbative light-front Hamiltonian methods

NASA Astrophysics Data System (ADS)

Hiller, J. R.

2016-09-01

We examine the current state-of-the-art in nonperturbative calculations done with Hamiltonians constructed in light-front quantization of various field theories. The language of light-front quantization is introduced, and important (numerical) techniques, such as Pauli-Villars regularization, discrete light-cone quantization, basis light-front quantization, the light-front coupled-cluster method, the renormalization group procedure for effective particles, sector-dependent renormalization, and the Lanczos diagonalization method, are surveyed. Specific applications are discussed for quenched scalar Yukawa theory, ϕ4 theory, ordinary Yukawa theory, supersymmetric Yang-Mills theory, quantum electrodynamics, and quantum chromodynamics. The content should serve as an introduction to these methods for anyone interested in doing such calculations and as a rallying point for those who wish to solve quantum chromodynamics in terms of wave functions rather than random samplings of Euclidean field configurations.

Biomechanics of front and back squat exercises

NASA Astrophysics Data System (ADS)

Braidot, A. A.; Brusa, M. H.; Lestussi, F. E.; Parera, G. P.

2007-11-01

Squat constitutes one of the most popular exercises to strengthen the muscles of the lower limbs. It is considered one of the most widely spread exercises for muscle sport training and is part of the competition movements comprised within olympic weight-lifting. In physical rehabilitation, squats are used for muscular recovery after different injuries of the lower limbs, especially the knee. In previous anterior cruciate ligament injuries, the mini-squats are generally used, in a knee flexion motion range from 0° to 50° because in this range the shear forces, the tibiofemoral and patellofemoral compression forces decrease related to greater flexion angles. The aim of this work is to make a comparative bidimensional study of the kinematic and dynamic variables of the excecution of the parallel squat exercise with the front and back bar. It is observed in the knee a better development of energy with the front bar, allowing a better muscular exercise with the same load. The mean power absorbed by the hip with the back bar is considerably greater, associated to the speed of the gesture.

Use of glacial fronts by narwhals (Monodon monoceros) in West Greenland

PubMed Central

Moon, Twila; Hauser, Donna D. W.; McGovern, Richard; Heide-Jørgensen, Mads Peter; Dietz, Rune; Hudson, Ben

2016-01-01

Glacial fronts are important summer habitat for narwhals (Monodon monoceros); however, no studies have quantified which glacial properties attract whales. We investigated the importance of glacial habitats using telemetry data from n = 15 whales tagged in September of 1993, 1994, 2006 and 2007 in Melville Bay, West Greenland. For 41 marine-terminating glaciers, we estimated (i) narwhal presence/absence, (ii) number of 24 h periods spent at glaciers and (iii) the fraction of narwhals that visited each glacier (at 5, 7 and 10 km) in autumn. We also compiled data on glacier width, ice thickness, ice velocity, front advance/retreat, area and extent of iceberg discharge, bathymetry, subglacial freshwater run-off and sediment flux. Narwhal use of glacial habitats expanded in the 2000s probably due to reduced summer fast ice and later autumn freeze-up. Using a generalized multivariate framework, glacier ice front thickness (vertical height in the water column) was a significant covariate in all models. A negative relationship with glacier velocity was included in several models and glacier front width was a significant predictor in the 2000s. Results suggest narwhals prefer glaciers with potential for higher ambient freshwater melt over glaciers with silt-laden discharge. This may represent a preference for summer freshwater habitat, similar to other Arctic monodontids. PMID:27784729

Fronts propagating with curvature dependent speed: Algorithms based on Hamilton-Jacobi formulations

NASA Technical Reports Server (NTRS)

Osher, Stanley; Sethian, James A.

1987-01-01

New numerical algorithms are devised (PSC algorithms) for following fronts propagating with curvature-dependent speed. The speed may be an arbitrary function of curvature, and the front can also be passively advected by an underlying flow. These algorithms approximate the equations of motion, which resemble Hamilton-Jacobi equations with parabolic right-hand-sides, by using techniques from the hyperbolic conservation laws. Non-oscillatory schemes of various orders of accuracy are used to solve the equations, providing methods that accurately capture the formation of sharp gradients and cusps in the moving fronts. The algorithms handle topological merging and breaking naturally, work in any number of space dimensions, and do not require that the moving surface be written as a function. The methods can be used also for more general Hamilton-Jacobi-type problems. The algorithms are demonstrated by computing the solution to a variety of surface motion problems.

50 CFR 660.408 - Annual actions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Annual actions. 660.408 Section 660.408... Annual actions. (a) General. NMFS will annually establish or, as necessary, adjust management specifications for the commercial, recreational, and treaty Indian fisheries by publishing the action in the...

50 CFR 660.408 - Annual actions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Annual actions. 660.408 Section 660.408... Annual actions. (a) General. NMFS will annually establish or, as necessary, adjust management specifications for the commercial, recreational, and treaty Indian fisheries by publishing the action in the...

Fronts and precipitation in CMIP5 models for the austral winter of the Southern Hemisphere

NASA Astrophysics Data System (ADS)

Blázquez, Josefina; Solman, Silvina A.

2018-04-01

Wintertime fronts climatology and the relationship between fronts and precipitation as depicted by a group of CMIP5 models are evaluated over the Southern Hemisphere (SH). The frontal activity is represented by an index that takes into account the vorticity, the gradient of temperature and the specific humidity at the 850 hPa level. ERA-Interim reanalysis and GPCP datasets are used to assess the performance of the models in the present climate. Overall, it is found that the models can reproduce adequately the main features of frontal activity and front frequency over the SH. The total precipitation is overestimated in most of the models, especially the maximum values over the mid latitudes. This overestimation could be related to the high values of precipitation frequency that are identified in some of the models evaluated. The relationship between fronts and precipitation has also been evaluated in terms of both frequency of frontal precipitation and percentage of precipitation due to fronts. In general terms, the models overestimate the proportion between frontal and total precipitation. In contrast with frequency of total precipitation, the frequency of frontal precipitation is well reproduced by the models, with the higher values located at the mid latitudes. The results suggest that models represent very well the dynamic forcing (fronts) and the frequency of frontal precipitation, though the amount of precipitation due to fronts is overestimated.

Modelling wildland fire propagation by tracking random fronts

NASA Astrophysics Data System (ADS)

Pagnini, G.; Mentrelli, A.

2013-11-01

Wildland fire propagation is studied in literature by two alternative approaches, namely the reaction-diffusion equation and the level-set method. These two approaches are considered alternative each other because the solution of the reaction-diffusion equation is generally a continuous smooth function that has an exponential decay and an infinite support, while the level-set method, which is a front tracking technique, generates a sharp function with a finite support. However, these two approaches can indeed be considered complementary and reconciled. Turbulent hot-air transport and fire spotting are phenomena with a random character that are extremely important in wildland fire propagation. As a consequence the fire front gets a random character, too. Hence a tracking method for random fronts is needed. In particular, the level-set contourn is here randomized accordingly to the probability density function of the interface particle displacement. Actually, when the level-set method is developed for tracking a front interface with a random motion, the resulting averaged process emerges to be governed by an evolution equation of the reaction-diffusion type. In this reconciled approach, the rate of spread of the fire keeps the same key and characterizing role proper to the level-set approach. The resulting model emerges to be suitable to simulate effects due to turbulent convection as fire flank and backing fire, the faster fire spread because of the actions by hot air pre-heating and by ember landing, and also the fire overcoming a firebreak zone that is a case not resolved by models based on the level-set method. Moreover, from the proposed formulation it follows a correction for the rate of spread formula due to the mean jump-length of firebrands in the downwind direction for the leeward sector of the fireline contour.

IFLA General Conference, 1986. Libraries Serving the General Public Division. Papers.

ERIC Educational Resources Information Center

International Federation of Library Associations and Institutions, The Hague (Netherlands).

This document includes papers on libraries serving the general public which were presented at the 1986 International Federation of Library Associations (IFLA) conference. The first paper, "Annual Reports of Sections and Round Tables of the Division of Libraries Serving the General Public" includes the following annual reports for fiscal year…

Cold Fronts Research Programme: Progress, Future Plans, and Research Directions.

NASA Astrophysics Data System (ADS)

Ryan, B. F.; Wilson, K. J.; Garratt, J. R.; Smith, R. K.

1985-09-01

Following the analysis of data collected during Phases land II of the Cold Fronts Research Programme (CFRP) a conceptual model for the Australian summertime "cool change" has been proposed. The model provides a focus and a framework for the design of Phase III.The model is based on data gathered from a mesoscale network centered on Mount Gambier, South Australia, and includes the coastal waters to the west and relatively flat terrain to the east. The first objective of Phase III is to generalize the model so that it is applicable to the ocean waters to the far west of Mount Gambier and to the more rugged terrain farther to the east in the vicinity of Melbourne, Victoria. The remaining objectives concentrate on resolving unsatisfactory aspects of the model such as the evolution of convective lines and the relationship between the surface cold front and the upper-tropospheric cold pool and its associated jet stream.The integrated nature of the Cold Fronts Research Programme has meant that it has stimulated a wide range of research activities that extend beyond the field observations. The associated investigations include climatological, theoretical, and numerical modeling studies.

34 CFR 300.715 - Annual reports.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Interior § 300.715 Annual reports. (a) In general. The advisory board established under § 300.714 must prepare and submit to the Secretary of the Interior and to Congress an annual report containing a... 34 Education 2 2014-07-01 2013-07-01 true Annual reports. 300.715 Section 300.715 Education...

34 CFR 300.715 - Annual reports.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Interior § 300.715 Annual reports. (a) In general. The advisory board established under § 300.714 must prepare and submit to the Secretary of the Interior and to Congress an annual report containing a... 34 Education 2 2012-07-01 2012-07-01 false Annual reports. 300.715 Section 300.715 Education...

34 CFR 300.715 - Annual reports.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Interior § 300.715 Annual reports. (a) In general. The advisory board established under § 300.714 must prepare and submit to the Secretary of the Interior and to Congress an annual report containing a... 34 Education 2 2013-07-01 2013-07-01 false Annual reports. 300.715 Section 300.715 Education...

Geologic map of the greater Denver area, Front Range urban corridor, Colorado

USGS Publications Warehouse

Trimble, Donald E.; Machette, Michael N.

1979-01-01

This digital map shows the areal extent of surficial deposits and rock stratigraphic units (formations) as compiled by Trimble and Machette from 1973 to 1977 and published in 1979 under the Front Range Urban Corridor Geology Program. Trimble and Machette compiled their geologic map from published geologic maps and unpublished geologic mapping having varied map unit schemes. A convenient feature of the compiled map is its uniform classification of geologic units that mostly matches those of companion maps to the north (USGS I-855-G) and to the south (USGS I-857-F). Published as a color paper map, the Trimble and Machette map was intended for land-use planning in the Front Range Urban Corridor. This map recently (1997-1999) was digitized under the USGS Front Range Infrastructure Resources Project. In general, the mountainous areas in the western part of the map exhibit various igneous and metamorphic bedrock units of Precambrian age, major faults, and fault brecciation zones at the east margin (5-20 km wide) of the Front Range. The eastern and central parts of the map (Colorado Piedmont) depict a mantle of unconsolidated deposits of Quaternary age and interspersed outcroppings of Cretaceous or Tertiary-Cretaceous sedimentary bedrock. The Quaternary mantle comprises eolian deposits (quartz sand and silt), alluvium (gravel, sand, and silt of variable composition), colluvium, and a few landslides. At the mountain front, north-trending, dipping Paleozoic and Mesozoic sandstone, shale, and limestone bedrock formations form hogbacks and intervening valleys.

An explanation of unstable wetting fronts in soils

NASA Astrophysics Data System (ADS)

Steenhuis, Tammo; Parlange, Jean-Yves; Kung, Samuel; Stoof, Cathelijne; Baver, Christine

2016-04-01

Despite the findings of Raats on unstable wetting front almost a half a century ago, simulating wetting fronts in soils is still an area of active research. One of the critical questions currently is whether Darcy law is valid at the wetting front. In this talk, we pose that in many cases for dry soils, Darcy's law does not apply because the pressure field across the front is not continuous. Consequently, the wetting front pressure is not dependent on the pressure ahead of the front but is determined by the radius of water meniscuses and the dynamic contact angle of the water. If we further assume since the front is discontinuous, that water flows at one pore at the time, then by using the modified Hoffman relationship - relating the dynamic contact angle to the pore water velocity - we find the elevated pressures at the wetting front typical for unstable flows that are similar to those observed experimentally in small diameter columns. The theory helps also explain the funnel flow phenomena observed in layered soils.

Use of glacial fronts by narwhals (Monodon monoceros) in West Greenland.

PubMed

Laidre, Kristin L; Moon, Twila; Hauser, Donna D W; McGovern, Richard; Heide-Jørgensen, Mads Peter; Dietz, Rune; Hudson, Ben

2016-10-01

Glacial fronts are important summer habitat for narwhals (Monodon monoceros); however, no studies have quantified which glacial properties attract whales. We investigated the importance of glacial habitats using telemetry data from n = 15 whales tagged in September of 1993, 1994, 2006 and 2007 in Melville Bay, West Greenland. For 41 marine-terminating glaciers, we estimated (i) narwhal presence/absence, (ii) number of 24 h periods spent at glaciers and (iii) the fraction of narwhals that visited each glacier (at 5, 7 and 10 km) in autumn. We also compiled data on glacier width, ice thickness, ice velocity, front advance/retreat, area and extent of iceberg discharge, bathymetry, subglacial freshwater run-off and sediment flux. Narwhal use of glacial habitats expanded in the 2000s probably due to reduced summer fast ice and later autumn freeze-up. Using a generalized multivariate framework, glacier ice front thickness (vertical height in the water column) was a significant covariate in all models. A negative relationship with glacier velocity was included in several models and glacier front width was a significant predictor in the 2000s. Results suggest narwhals prefer glaciers with potential for higher ambient freshwater melt over glaciers with silt-laden discharge. This may represent a preference for summer freshwater habitat, similar to other Arctic monodontids. © 2016 The Author(s).

Adaptive two-regime method: Application to front propagation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robinson, Martin, E-mail: martin.robinson@maths.ox.ac.uk; Erban, Radek, E-mail: erban@maths.ox.ac.uk; Flegg, Mark, E-mail: mark.flegg@monash.edu

2014-03-28

The Adaptive Two-Regime Method (ATRM) is developed for hybrid (multiscale) stochastic simulation of reaction-diffusion problems. It efficiently couples detailed Brownian dynamics simulations with coarser lattice-based models. The ATRM is a generalization of the previously developed Two-Regime Method [Flegg et al., J. R. Soc., Interface 9, 859 (2012)] to multiscale problems which require a dynamic selection of regions where detailed Brownian dynamics simulation is used. Typical applications include a front propagation or spatio-temporal oscillations. In this paper, the ATRM is used for an in-depth study of front propagation in a stochastic reaction-diffusion system which has its mean-field model given in termsmore » of the Fisher equation [R. Fisher, Ann. Eugen. 7, 355 (1937)]. It exhibits a travelling reaction front which is sensitive to stochastic fluctuations at the leading edge of the wavefront. Previous studies into stochastic effects on the Fisher wave propagation speed have focused on lattice-based models, but there has been limited progress using off-lattice (Brownian dynamics) models, which suffer due to their high computational cost, particularly at the high molecular numbers that are necessary to approach the Fisher mean-field model. By modelling only the wavefront itself with the off-lattice model, it is shown that the ATRM leads to the same Fisher wave results as purely off-lattice models, but at a fraction of the computational cost. The error analysis of the ATRM is also presented for a morphogen gradient model.« less

Ecological invasion, roughened fronts, and a competitor's extreme advance: integrating stochastic spatial-growth models.

PubMed

O'Malley, Lauren; Korniss, G; Caraco, Thomas

2009-07-01

Both community ecology and conservation biology seek further understanding of factors governing the advance of an invasive species. We model biological invasion as an individual-based, stochastic process on a two-dimensional landscape. An ecologically superior invader and a resident species compete for space preemptively. Our general model includes the basic contact process and a variant of the Eden model as special cases. We employ the concept of a "roughened" front to quantify effects of discreteness and stochasticity on invasion; we emphasize the probability distribution of the front-runner's relative position. That is, we analyze the location of the most advanced invader as the extreme deviation about the front's mean position. We find that a class of models with different assumptions about neighborhood interactions exhibits universal characteristics. That is, key features of the invasion dynamics span a class of models, independently of locally detailed demographic rules. Our results integrate theories of invasive spatial growth and generate novel hypotheses linking habitat or landscape size (length of the invading front) to invasion velocity, and to the relative position of the most advanced invader.

Advanced RF Front End Technology

NASA Technical Reports Server (NTRS)

Herman, M. I.; Valas, S.; Katehi, L. P. B.

2001-01-01

The ability to achieve low-mass low-cost micro/nanospacecraft for Deep Space exploration requires extensive miniaturization of all subsystems. The front end of the Telecommunication subsystem is an area in which major mass (factor of 10) and volume (factor of 100) reduction can be achieved via the development of new silicon based micromachined technology and devices. Major components that make up the front end include single-pole and double-throw switches, diplexer, and solid state power amplifier. JPL's Center For Space Microsystems - System On A Chip (SOAC) Program has addressed the challenges of front end miniaturization (switches and diplexers). Our objectives were to develop the main components that comprise a communication front end and enable integration in a single module that we refer to as a 'cube'. In this paper we will provide the latest status of our Microelectromechanical System (MEMS) switches and surface micromachined filter development. Based on the significant progress achieved we can begin to provide guidelines of the proper system insertion for these emerging technologies. Additional information is contained in the original extended abstract.

Flux front penetration in disordered superconductors.

PubMed

Zapperi, S; Moreira, A A; Andrade, J S

2001-04-16

We investigate flux front penetration in a disordered type-II superconductor by molecular dynamics simulations of interacting vortices and find scaling laws for the front position and the density profile. The scaling can be understood by performing a coarse graining of the system and writing a disordered nonlinear diffusion equation. Integrating numerically the equation, we observe a crossover from flat to fractal front penetration as the system parameters are varied. The value of the fractal dimension indicates that the invasion process is described by gradient percolation.

1. GENERAL VIEW, (the one with the woman at the ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. GENERAL VIEW, (the one with the woman at the front door). Photocopy of December 1957 photo on file at Philadelphia Historical Commission - James Keen House, 946 South Front Street, Philadelphia, Philadelphia County, PA

Surface properties of ocean fronts

NASA Technical Reports Server (NTRS)

Wolff, P. M.; Hubert, W. E.

1976-01-01

Background information on oceanic fronts is presented and the results of several models which were developed to study the dynamics of oceanic fronts and their effects on various surface properties are described. The details of the four numerical models used in these studies are given in separate appendices which contain all of the physical equations, program documentation and running instructions for the models.

Particle versus density models in spark formation: X-rays from pulled fronts?

NASA Astrophysics Data System (ADS)

Ebert, Ute

2008-03-01

Streamer discharges govern the early stages of sparks and lightning, of spark-like phenomena in water, oil, and semiconductors, in industrial corona reactors, or in gigantic sprite discharges above thunderclouds [1,2]. Thunderstorms recently have been found to emit terrestrial gamma-ray flashes or X-rays towards satellites and towards the ground. These emissions might be explained by particle models of ``pulled'' streamer ionization fronts. In general, the growing discharge channel has an inner structure with multiple scales [1-3]. While the largest part of this channel can be treated in a density approximation for the electrons and ions, the dynamics of the ionization front is that of a pulled front; it is determined in the leading edge where the density approach eventually breaks down. We therefore investigate a realistic MC particle model for the motion of single electrons in a discharge in pure nitrogen. The particle model not only incorporates particle fluctuations, but also shows that the electron energies are systematically larger in the leading edge of the front than in the corresponding density model, and that the ionization level behind the front is higher as well, while the front velocity hardly changes [3]. These effects increase with increasing applied electric field and might actually cause the recently observed X-ray emission from lightning through rare very energetic runaway electrons in the tail of the distribution. Comparing the leading edge of the particle front with a linear particle avalanche, the avalanche shows the same mean density gradient and energy overshoot in its leading edge as the nonlinear front; hence the pulled front concept in this sense applies to discrete particle models as well [3]. This gives a key to understanding the above effects through analytical approximations and to develop efficient numerical methods coupling particle and density models in space.[1] U. Ebert et al., Plasma Sources Sci. Techn. 15, S118 (2006) (ar

5 CFR 531.207 - Applying annual pay adjustments.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Applying annual pay adjustments. 531.207 Section 531.207 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY UNDER THE GENERAL SCHEDULE Determining Rate of Basic Pay General Provisions § 531.207 Applying annual...

Convection induced by thermal gradients on thin reaction fronts

NASA Astrophysics Data System (ADS)

Ruelas Paredes, David R. A.; Vasquez, Desiderio A.

2017-09-01

We present a thin front model for the propagation of chemical reaction fronts in liquids inside a Hele-Shaw cell or porous media. In this model we take into account density gradients due to thermal and compositional changes across a thin interface. The front separating reacted from unreacted fluids evolves following an eikonal relation between the normal speed and the curvature. We carry out a linear stability analysis of convectionless flat fronts confined in a two-dimensional rectangular domain. We find that all fronts are stable to perturbations of short wavelength, but they become unstable for some wavelengths depending on the values of compositional and thermal gradients. If the effects of these gradients oppose each other, we observe a range of wavelengths that make the flat front unstable. Numerical solutions of the nonlinear model show curved fronts of steady shape with convection propagating faster than flat fronts. Exothermic fronts increase the temperature of the fluid as they propagate through the domain. This increment in temperature decreases with increasing speed.

Patterns of spiral wave attenuation by low-frequency periodic planar fronts

NASA Astrophysics Data System (ADS)

de la Casa, Miguel A.; de la Rubia, F. Javier; Ivanov, Plamen Ch.

2007-03-01

There is evidence that spiral waves and their breakup underlie mechanisms related to a wide spectrum of phenomena ranging from spatially extended chemical reactions to fatal cardiac arrhythmias [A. T. Winfree, The Geometry of Biological Time (Springer-Verlag, New York, 2001); J. Schutze, O. Steinbock, and S. C. Muller, Nature 356, 45 (1992); S. Sawai, P. A. Thomason, and E. C. Cox, Nature 433, 323 (2005); L. Glass and M. C. Mackey, From Clocks to Chaos: The Rhythms of Life (Princeton University Press, Princeton, 1988); R. A. Gray et al., Science 270, 1222 (1995); F. X. Witkowski et al., Nature 392, 78 (1998)]. Once initiated, spiral waves cannot be suppressed by periodic planar fronts, since the domains of the spiral waves grow at the expense of the fronts [A. N. Zaikin and A. M. Zhabotinsky, Nature 225, 535 (1970); A. T. Stamp, G. V. Osipov, and J. J. Collins, Chaos 12, 931 (2002); I. Aranson, H. Levine, and L. Tsimring, Phys. Rev. Lett. 76, 1170 (1996); K. J. Lee, Phys. Rev. Lett. 79, 2907 (1997); F. Xie, Z. Qu, J. N. Weiss, and A. Garfinkel, Phys. Rev. E 59, 2203 (1999)]. Here, we show that introducing periodic planar waves with long excitation duration and a period longer than the rotational period of the spiral can lead to spiral attenuation. The attenuation is not due to spiral drift and occurs periodically over cycles of several fronts, forming a variety of complex spatiotemporal patterns, which fall into two distinct general classes. Further, we find that these attenuation patterns only occur at specific phases of the descending fronts relative to the rotational phase of the spiral. We demonstrate these dynamics of phase-dependent spiral attenuation by performing numerical simulations of wave propagation in the excitable medium of myocardial cells. The effect of phase-dependent spiral attenuation we observe can lead to a general approach to spiral control in physical and biological systems with relevance for medical applications.

Wave-front singularities for two-dimensional anisotropic elastic waves.

NASA Technical Reports Server (NTRS)

Payton, R. G.

1972-01-01

Wavefront singularities for the displacement functions, associated with the radiation of linear elastic waves from a point source embedded in a finitely strained two-dimensional elastic solid, are examined in detail. It is found that generally the singularities are of order d to the -1/2 power, where d measures distance away from the front. However, in certain exceptional cases singularities of order d to the -n power, where n = 1/4, 2/3, 3/4, may be encountered.

Wintertime sea surface temperature fronts in the Taiwan Strait

NASA Astrophysics Data System (ADS)

Chang, Yi; Shimada, Teruhisa; Lee, Ming-An; Lu, Hsueh-Jung; Sakaida, Futoki; Kawamura, Hiroshi

2006-12-01

We present wintertime variations and distributions of sea surface temperature (SST) fronts in the Taiwan Strait by applying an entropy-based edge detection method to 10-year (1996-2005) satellite SST images with grid size of 0.01°. From climatological monthly mean maps of SST gradient magnitude in winter, we identify four significant SST fronts in the Taiwan Strait. The Mainland China Coastal Front is a long frontal band along the 50-m isobath near the Chinese coast. The sharp Peng-Chang Front appears along the Peng-Hu Channel and extends northward around the Chang-Yuen Ridge. The Taiwan Bank Front evolves in early winter. As the winter progresses, the front becomes broad and moves toward the Chinese coast, connecting to the Mainland China Coastal Front. The Kuroshio Front extends northeastward from the northeastern tip of Taiwan with a semicircle-shape curving along the 100-m isobath.

Characterizing Ion Flows Across a Dipolarization Front

NASA Astrophysics Data System (ADS)

Arnold, H.; Drake, J. F.; Swisdak, M.

2017-12-01

In light of the Magnetospheric Multiscale Mission (MMS) moving to study predominately symmetric magnetic reconnection in the Earth's magnetotail, it is of interest to investigate various methods for determining the relative location of the satellites with respect to the x line or a dipolarization front. We use a 2.5 dimensional PIC simulation to explore the dependence of various characteristics of a front, or flux bundle, on the width of the front in the dawn-dusk direction. In particular, we characterize the ion flow in the x-GSM direction across the front. We find a linear relationship between the width of a front, w, and the maximum velocity of the ion flow in the x-GSM direction, Vxi, for small widths: Vxi/VA=w/di*1/2*(mVA2)/Ti*Bz/Bxwhere m, VA, di, Ti, Bz, and Bx are the ion mass, upstream Alfven speed, ion inertial length, ion temperature, and magnetic fields in the z-GSM and x-GSM directions respectively. However, once the width reaches around 5 di, the relationship gradually approaches the well-known theoretical limit for ion flows, the upstream Alfven speed. Furthermore, we note that there is a reversal in the Hall magnetic field near the current sheet on the positive y-GSM side of the front. This reversal is most likely due to conservation of momentum in the y-GSM direction as the ions accelerate towards the x-GSM direction. This indicates that while the ions are primarily energized in the x-GSM direction by the front, they transfer energy to the electromagnetic fields in the y-GSM direction. The former energy transfer is greater than the latter, but the reversal of the Hall magnetic field drags the frozen-in electrons along with it outside of the front. These simulations should better able researchers to determine the relative location of a satellite crossing a dipolarization front.

A multitasking, multisinked, multiprocessor data acquisition front end

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fox, R.; Au, R.; Molen, A.V.

1989-10-01

The authors have developed a generalized data acquisition front end system which is based on MC68020 processors running a commercial real time kernel (rhoSOS), and implemented primarily in a high level language (C). This system has been attached to the back end on-line computing system at NSCL via our high performance ETHERNET protocol. Data may be simultaneously sent to any number of back end systems. Fixed fraction sampling along links to back end computing is also supported. A nonprocedural program generator simplifies the development of experiment specific code.

Pareto-front shape in multiobservable quantum control

NASA Astrophysics Data System (ADS)

Sun, Qiuyang; Wu, Re-Bing; Rabitz, Herschel

2017-03-01

Many scenarios in the sciences and engineering require simultaneous optimization of multiple objective functions, which are usually conflicting or competing. In such problems the Pareto front, where none of the individual objectives can be further improved without degrading some others, shows the tradeoff relations between the competing objectives. This paper analyzes the Pareto-front shape for the problem of quantum multiobservable control, i.e., optimizing the expectation values of multiple observables in the same quantum system. Analytic and numerical results demonstrate that with two commuting observables the Pareto front is a convex polygon consisting of flat segments only, while with noncommuting observables the Pareto front includes convexly curved segments. We also assess the capability of a weighted-sum method to continuously capture the points along the Pareto front. Illustrative examples with realistic physical conditions are presented, including NMR control experiments on a 1H-13C two-spin system with two commuting or noncommuting observables.

Modelling wildland fire propagation by tracking random fronts

NASA Astrophysics Data System (ADS)

Pagnini, G.; Mentrelli, A.

2014-08-01

Wildland fire propagation is studied in the literature by two alternative approaches, namely the reaction-diffusion equation and the level-set method. These two approaches are considered alternatives to each other because the solution of the reaction-diffusion equation is generally a continuous smooth function that has an exponential decay, and it is not zero in an infinite domain, while the level-set method, which is a front tracking technique, generates a sharp function that is not zero inside a compact domain. However, these two approaches can indeed be considered complementary and reconciled. Turbulent hot-air transport and fire spotting are phenomena with a random nature and they are extremely important in wildland fire propagation. Consequently, the fire front gets a random character, too; hence, a tracking method for random fronts is needed. In particular, the level-set contour is randomised here according to the probability density function of the interface particle displacement. Actually, when the level-set method is developed for tracking a front interface with a random motion, the resulting averaged process emerges to be governed by an evolution equation of the reaction-diffusion type. In this reconciled approach, the rate of spread of the fire keeps the same key and characterising role that is typical of the level-set approach. The resulting model emerges to be suitable for simulating effects due to turbulent convection, such as fire flank and backing fire, the faster fire spread being because of the actions by hot-air pre-heating and by ember landing, and also due to the fire overcoming a fire-break zone, which is a case not resolved by models based on the level-set method. Moreover, from the proposed formulation, a correction follows for the formula of the rate of spread which is due to the mean jump length of firebrands in the downwind direction for the leeward sector of the fireline contour. The presented study constitutes a proof of concept, and it

12 CFR 252.144 - Annual stress test.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 4 2014-01-01 2014-01-01 false Annual stress test. 252.144 Section 252.144... (CONTINUED) ENHANCED PRUDENTIAL STANDARDS (REGULATION YY) Company-Run Stress Test Requirements for Covered Companies § 252.144 Annual stress test. (a) In general. A covered company must conduct an annual stress test...

12 CFR 1238.3 - Annual stress test.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 10 2014-01-01 2014-01-01 false Annual stress test. 1238.3 Section 1238.3 Banks and Banking FEDERAL HOUSING FINANCE AGENCY ENTITY REGULATIONS STRESS TESTING OF REGULATED ENTITIES § 1238.3 Annual stress test. (a) In general. Each regulated entity: (1) Shall complete an annual stress...

12 CFR 252.144 - Annual stress test.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 4 2013-01-01 2013-01-01 false Annual stress test. 252.144 Section 252.144... (CONTINUED) ENHANCED PRUDENTIAL STANDARDS (REGULATION YY) Company-Run Stress Test Requirements for Covered Companies § 252.144 Annual stress test. (a) In general. A covered company must conduct an annual stress test...

5 CFR 550.184 - Annual certification.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Annual certification. 550.184 Section 550.184 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION (GENERAL) Premium Pay Law Enforcement Availability Pay § 550.184 Annual certification. (a) Each...

5 CFR 550.184 - Annual certification.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Annual certification. 550.184 Section 550.184 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION (GENERAL) Premium Pay Law Enforcement Availability Pay § 550.184 Annual certification. (a) Each...

5 CFR 550.184 - Annual certification.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Annual certification. 550.184 Section 550.184 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION (GENERAL) Premium Pay Law Enforcement Availability Pay § 550.184 Annual certification. (a) Each...

5 CFR 550.184 - Annual certification.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Annual certification. 550.184 Section 550.184 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION (GENERAL) Premium Pay Law Enforcement Availability Pay § 550.184 Annual certification. (a) Each...

5 CFR 550.184 - Annual certification.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Annual certification. 550.184 Section 550.184 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION (GENERAL) Premium Pay Law Enforcement Availability Pay § 550.184 Annual certification. (a) Each...

Annual Check-up

MedlinePlus

... Guides Quizzes Parents About Us Donate General Health Sexual Health Medical Conditions Nutrition & Fitness Emotional Health Annual Check- ... re under the age of 18. Issues about sexual health, HIV, and STIs will be kept confidential. How ...

Speed of fast and slow rupture fronts along frictional interfaces

NASA Astrophysics Data System (ADS)

Trømborg, Jørgen Kjoshagen; Sveinsson, Henrik Andersen; Thøgersen, Kjetil; Scheibert, Julien; Malthe-Sørenssen, Anders

2015-07-01

The transition from stick to slip at a dry frictional interface occurs through the breaking of microjunctions between the two contacting surfaces. Typically, interactions between junctions through the bulk lead to rupture fronts propagating from weak and/or highly stressed regions, whose junctions break first. Experiments find rupture fronts ranging from quasistatic fronts, via fronts much slower than elastic wave speeds, to fronts faster than the shear wave speed. The mechanisms behind and selection between these fronts are still imperfectly understood. Here we perform simulations in an elastic two-dimensional spring-block model where the frictional interaction between each interfacial block and the substrate arises from a set of junctions modeled explicitly. We find that material slip speed and rupture front speed are proportional across the full range of front speeds we observe. We revisit a mechanism for slow slip in the model and demonstrate that fast slip and fast fronts have a different, inertial origin. We highlight the long transients in front speed even along homogeneous interfaces, and we study how both the local shear to normal stress ratio and the local strength are involved in the selection of front type and front speed. Last, we introduce an experimentally accessible integrated measure of block slip history, the Gini coefficient, and demonstrate that in the model it is a good predictor of the history-dependent local static friction coefficient of the interface. These results will contribute both to building a physically based classification of the various types of fronts and to identifying the important mechanisms involved in the selection of their propagation speed.

Hindrances to bistable front propagation: application to Wolbachia invasion.

PubMed

Nadin, Grégoire; Strugarek, Martin; Vauchelet, Nicolas

2018-05-01

We study the biological situation when an invading population propagates and replaces an existing population with different characteristics. For instance, this may occur in the presence of a vertically transmitted infection causing a cytoplasmic effect similar to the Allee effect (e.g. Wolbachia in Aedes mosquitoes): the invading dynamics we model is bistable. We aim at quantifying the propagules (what does it take for an invasion to start?) and the invasive power (how far can an invading front go, and what can stop it?). We rigorously show that a heterogeneous environment inducing a strong enough population gradient can stop an invading front, which will converge in this case to a stable front. We characterize the critical population jump, and also prove the existence of unstable fronts above the stable (blocking) fronts. Being above the maximal unstable front enables an invading front to clear the obstacle and propagate further. We are particularly interested in the case of artificial Wolbachia infection, used as a tool to fight arboviruses.

The design of CMOS general-purpose analog front-end circuit with tunable gain and bandwidth for biopotential signal recording systems.

PubMed

Chen, Wei-Ming; Yang, Wen-Chia; Tsai, Tzung-Yun; Chiueh, Herming; Wu, Chung-Yu

2011-01-01

In this paper an 8-channel CMOS general-purpose analog front-end (AFE) circuit with tunable gain and bandwidth for biopotential signal recording systems is presented. The proposed AFE consists of eight chopper stabilized pre-amplifiers, an 8-to-1 analog multiplexer, and a programmable gain amplifier. It can be used to sense and amplify different kinds of biopotential signals, such as electrocorticogram (ECoG), electrocardiogram (ECG) and electromyogram (EMG). The AFE chip is designed and fabricated in 0.18-μm CMOS technology. The measured maximum gain of AFE is 60.8 dB. The low cutoff frequency can achieve as low as 0.8 Hz and high cutoff frequency can be adjusted from 200 Hz to 10 kHz to suit for different kinds of biopotential signals. The measured input-referred noise is 0.9 μV(rms), with the power consumption of 18μW per channel at 1.8-V power supply. And the noise efficiency factor (NEF) is only 1.3 for pre-amplifier.

The annual cycle of stratospheric water vapor in a general circulation model

NASA Technical Reports Server (NTRS)

Mote, Philip W.

1995-01-01

The application of general circulation models (GCM's) to stratospheric chemistry and transport both permits and requires a thorough investigation of stratospheric water vapor. The National Center for Atmospheric Research has redesigned its GCM, the Community Climate Model (CCM2), to enable studies of the chemistry and transport of tracers including water vapor; the importance of water vapor to the climate and chemistry of the stratosphere requires that it be better understood in the atmosphere and well represented in the model. In this study, methane is carried as a tracer and converted to water; this simple chemistry provides an adequate representation of the upper stratospheric water vapor source. The cold temperature bias in the winter polar stratosphere, which the CCM2 shares with other GCM's, produces excessive dehydration in the southern hemisphere, but this dry bias can be ameliorated by setting a minimum vapor pressure. The CCM2's water vapor distribution and seasonality compare favorably with observations in many respects, though seasonal variations including the upper stratospheric semiannual oscillation are generally too small. Southern polar dehydration affects midlatitude water vapor mixing ratios by a few tenths of a part per million, mostly after the demise of the vortex. The annual cycle of water vapor in the tropical and northern midlatitude lower stratosphere is dominated by drying at the tropical tropopause. Water vapor has a longer adjustment time than methane and had not reached equilibrium at the end of the 9 years simulated here.

45 CFR 2400.2 - Annual competition.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Annual competition. 2400.2 Section 2400.2 Public Welfare Regulations Relating to Public Welfare (Continued) JAMES MADISON MEMORIAL FELLOWSHIP FOUNDATION FELLOWSHIP PROGRAM REQUIREMENTS General § 2400.2 Annual competition. To achieve its principal purposes, the...

45 CFR 2400.2 - Annual competition.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Annual competition. 2400.2 Section 2400.2 Public Welfare Regulations Relating to Public Welfare (Continued) JAMES MADISON MEMORIAL FELLOWSHIP FOUNDATION FELLOWSHIP PROGRAM REQUIREMENTS General § 2400.2 Annual competition. To achieve its principal purposes, the...

The Pressure Available for Ground Cooling in Front of the Cowling of Air-cooled Airplane Engines

NASA Technical Reports Server (NTRS)

Stickle, George W; Joyner, Upshur T

1938-01-01

A study was made of the factors affecting the pressure available for ground cooling in front of a cowling. Most of the results presented were obtained with a set-up that was about one-third full scale. A number of isolated tests on four full-scale airplanes were made to determine the general applicability of the model results. The full-scale tests indicated that the model results may be applied qualitatively to full-scale design and quantitatively as a first approximation of the front pressure available for ground cooling.

Modeling annual extreme temperature using generalized extreme value distribution: A case study in Malaysia

NASA Astrophysics Data System (ADS)

Hasan, Husna; Salam, Norfatin; Kassim, Suraiya

2013-04-01

Extreme temperature of several stations in Malaysia is modeled by fitting the annual maximum to the Generalized Extreme Value (GEV) distribution. The Augmented Dickey Fuller (ADF) and Phillips Perron (PP) tests are used to detect stochastic trends among the stations. The Mann-Kendall (MK) test suggests a non-stationary model. Three models are considered for stations with trend and the Likelihood Ratio test is used to determine the best-fitting model. The results show that Subang and Bayan Lepas stations favour a model which is linear for the location parameters while Kota Kinabalu and Sibu stations are suitable with a model in the logarithm of the scale parameters. The return level is the level of events (maximum temperature) which is expected to be exceeded once, on average, in a given number of years, is obtained.

Ecosystem responses to biogeochemical fronts in the South Brazil Bight

NASA Astrophysics Data System (ADS)

Brandini, Frederico P.; Tura, Pedro M.; Santos, Pedro P. G. M.

2018-05-01

Here we described the general hydrography in the South Brazil Bight (23-28°S) with emphasis on frontal processes and their role in the structure and functioning of the regional shelf ecosystem. One of the key roles of fronts for ecosystem dynamics is the injection of nutrients into the euphotic zone increasing primary production. Frontal systems also affect plankton biodiversity and fisheries. Physical mechanisms behind frontogenesis in this region are similar in the analogous western side of oceanic basins; their magnitude and seasonal dynamics, however, may differ due to peculiarities in shelf morphology, wind field, tidal circulation and continental drainage. Here we provide a reassessment of earlier and recent ecological and hydrographic studies for a better evaluation of the spatial and temporal dynamics of fronts and their regional ecological implications. Albeit in a fragmented manner, we give a more detailed conceptual framework about the ecosystem responses to the complex frontal system in the South Brazil Bight.

Transition fronts of time periodic bistable reaction-diffusion equations in RN

NASA Astrophysics Data System (ADS)

Sheng, Wei-Jie; Guo, Hong-Jun

2018-09-01

This paper is concerned with the existence and qualitative properties of transition fronts for time periodic bistable reaction-diffusion equations in RN. We first show that any almost-planar transition front is actually planar, regardless of the number of transition layers. Then we prove that all transition fronts admit a global mean speed γ and it holds γ = | c |, where c is the speed of the planar traveling front. Finally we establish the existence of a transition front in RN that is not a standard traveling front. Such a front behaves like three moving time periodic planar fronts as time goes to -∞ and like a time periodic V-shaped traveling front as time goes to ∞.

Light-front representation of chiral dynamics in peripheral transverse densities

DOE PAGES

Granados, Carlos G.; Weiss, Christian

2015-07-31

The nucleon's electromagnetic form factors are expressed in terms of the transverse densities of charge and magnetization at fixed light-front time. At peripheral transverse distances b = O(M_pi^{-1}) the densities are governed by chiral dynamics and can be calculated model-independently using chiral effective field theory (EFT). We represent the leading-order chiral EFT results for the peripheral transverse densities as overlap integrals of chiral light-front wave functions, describing the transition of the initial nucleon to soft pion-nucleon intermediate states and back. The new representation (a) explains the parametric order of the peripheral transverse densities; (b) establishes an inequality between the spin-independentmore » and -dependent densities; (c) exposes the role of pion orbital angular momentum in chiral dynamics; (d) reveals a large left-right asymmetry of the current in a transversely polarized nucleon and suggests a simple interpretation. The light-front representation enables a first-quantized, quantum-mechanical view of chiral dynamics that is fully relativistic and exactly equivalent to the second-quantized, field-theoretical formulation. It relates the charge and magnetization densities measured in low-energy elastic scattering to the generalized parton distributions probed in peripheral high-energy scattering processes. The method can be applied to nucleon form factors of other operators, e.g. the energy-momentum tensor.« less

Radiative thermal conduction fronts

NASA Technical Reports Server (NTRS)

Borkowski, Kazimierz J.; Balbus, Steven A.; Fristrom, Carl C.

1990-01-01

The discovery of the O VI interstellar absorption lines in our Galaxy by the Copernicus observatory was a turning point in our understanding of the Interstellar Medium (ISM). It implied the presence of widespread hot (approx. 10 to the 6th power K) gas in disk galaxies. The detection of highly ionized species in quasi-stellar objects' absorption spectra may be the first indirect observation of this hot phase in external disk galaxies. Previous efforts to understand extensive O VI absorption line data from our Galaxy were not very successful in locating the regions where this absorption originates. The location at interfaces between evaporating ISM clouds and hot gas was favored, but recent studies of steady-state conduction fronts in spherical clouds by Ballet, Arnaud, and Rothenflug (1986) and Bohringer and Hartquist (1987) rejected evaporative fronts as the absorption sites. Researchers report here on time-dependent nonequilibrium calculations of planar conductive fronts whose properties match well with observations, and suggest reasons for the difference between the researchers' results and the above. They included magnetic fields in additional models, not reported here, and the conclusions are not affected by their presence.

Radiative thermal conduction fronts

NASA Astrophysics Data System (ADS)

Borkowski, Kazimierz J.; Balbus, Steven A.; Fristrom, Carl C.

1990-07-01

The discovery of the O VI interstellar absorption lines in our Galaxy by the Copernicus observatory was a turning point in our understanding of the Interstellar Medium (ISM). It implied the presence of widespread hot (approx. 10 to the 6th power K) gas in disk galaxies. The detection of highly ionized species in quasi-stellar objects' absorption spectra may be the first indirect observation of this hot phase in external disk galaxies. Previous efforts to understand extensive O VI absorption line data from our Galaxy were not very successful in locating the regions where this absorption originates. The location at interfaces between evaporating ISM clouds and hot gas was favored, but recent studies of steady-state conduction fronts in spherical clouds by Ballet, Arnaud, and Rothenflug (1986) and Bohringer and Hartquist (1987) rejected evaporative fronts as the absorption sites. Researchers report here on time-dependent nonequilibrium calculations of planar conductive fronts whose properties match well with observations, and suggest reasons for the difference between the researchers' results and the above. They included magnetic fields in additional models, not reported here, and the conclusions are not affected by their presence.

5 CFR 550.106 - Annual maximum earnings limitation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Annual maximum earnings limitation. 550... PAY ADMINISTRATION (GENERAL) Premium Pay Maximum Earnings Limitations § 550.106 Annual maximum... and premium pay for the calendar year to exceed the greater of— (1) The maximum annual rate of basic...

46 CFR 42.09-40 - Annual surveys.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Annual surveys. 42.09-40 Section 42.09-40 Shipping COAST... Line Assignments and Surveys-General Requirements § 42.09-40 Annual surveys. (a) Relative to §§ 42.09-15(d) and 42.09-20(c), the assigning and issuing authority shall make an annual survey of each vessel...

46 CFR 42.09-40 - Annual surveys.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Annual surveys. 42.09-40 Section 42.09-40 Shipping COAST... Line Assignments and Surveys-General Requirements § 42.09-40 Annual surveys. (a) Relative to §§ 42.09-15(d) and 42.09-20(c), the assigning and issuing authority shall make an annual survey of each vessel...

46 CFR 42.09-40 - Annual surveys.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Annual surveys. 42.09-40 Section 42.09-40 Shipping COAST... Line Assignments and Surveys-General Requirements § 42.09-40 Annual surveys. (a) Relative to §§ 42.09-15(d) and 42.09-20(c), the assigning and issuing authority shall make an annual survey of each vessel...

46 CFR 42.09-40 - Annual surveys.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Annual surveys. 42.09-40 Section 42.09-40 Shipping COAST... Line Assignments and Surveys-General Requirements § 42.09-40 Annual surveys. (a) Relative to §§ 42.09-15(d) and 42.09-20(c), the assigning and issuing authority shall make an annual survey of each vessel...

46 CFR 42.09-40 - Annual surveys.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Annual surveys. 42.09-40 Section 42.09-40 Shipping COAST... Line Assignments and Surveys-General Requirements § 42.09-40 Annual surveys. (a) Relative to §§ 42.09-15(d) and 42.09-20(c), the assigning and issuing authority shall make an annual survey of each vessel...

Fronts, meanders and eddies in Drake Passage during the ANT-XXIII/3 cruise in January-February 2006: A satellite perspective

NASA Astrophysics Data System (ADS)

Barré, Nicolas; Provost, Christine; Renault, Alice; Sennéchael, Nathalie

2011-12-01

We used satellite altimetric data to provide a context for the results of the ANT-XXIII/3 cruise in January-February 2006 both in time (16 years) and space (the whole of Drake Passage). The repeat of the hydrographical section within 3 weeks permitted different comparisons between the in-situ datasets and the satellite data products. Comparisons suggested that the multi-satellite product improved the temporal resolution on a Jason-1 track. A detailed analysis of the four absolute dynamic topography maps contemporaneous with the ANT-XXIII/3 cruise permitted identification of the location of the frontal branches of the Antarctic Circumpolar Current, of the major meanders and eddies. This spatial context proved particularly valuable for the interpretation of the in-situ data (see companion papers of Provost et al., 2011; Renault et al., 2011; Sudre et al., 2011). The altimetric time-series documented the long-term trends in sea-surface height, the recurrence of major frontal meanders and eddies and the statistical links between them. Negative trends in the Yaghan Basin indicated that both the Subantarctic Front and the Polar Front have shifted to the north of their climatological location. This northward shift in the Yaghan Basin contrasts with the large-scale southward shift in the Polar Front current core described in the literature, and is probably related to the local bottom topography in Drake Passage. Sea-level anomaly patterns observed during the cruise were related to statistical modes of the corresponding variations in Drake Passage. For example, the southward meander of the Subantarctic Front at the entrance to Drake Passage was part of a dipole comprising an adjacent Polar Front meander and occurred with a close to annual periodicity. A census of eddies in the Ona Basin revealed that the spatial distribution of anticyclonic eddies was consistent with generation from a meander of the Polar and Southern ACC Fronts over the Ona Seafloor Depression, while

Social perceptions versus meteorological observations of snow and winter along the Front Range

NASA Astrophysics Data System (ADS)

Milligan, William James, IV

This research aims to increase understanding of Front Range residents' perceptions of snow, winter and hydrologic events. This study also investigates how an individual's characteristics may shape perceptions of winter weather and climate. A survey was administered to determine if perceptions of previous winters align with observed meteorological data. The survey also investigated how individual characteristics influence perceptions of snow and winter weather. The survey was conducted primarily along the Front Range area of the state of Colorado in the United States of America. This is a highly populated semi-arid region that acts as an interface between the agricultural plains to the east that extend to the Mississippi River and the Rocky Mountains to the west. The climate is continental, and while many people recreate in the snowy areas of the mountains, most live where annual snowfall amounts are low. Precipitation, temperature, and wind speed datasets from selected weather stations were analyzed to determine correct survey responses. Survey analysis revealed that perceptions of previous winters do not necessarily align with observed meteorological data. The mean percentage of correct responses to all survey questions was 36.8%. Further analysis revealed that some individual characteristics (e.g. winter recreation, source of winter weather information) did influence correct responses to survey questions.

End-Users, Front Ends and Librarians.

ERIC Educational Resources Information Center

Bourne, Donna E.

1989-01-01

The increase in end-user searching, the advantages and limitations of front ends, and the role of the librarian in end-user searching are discussed. It is argued that librarians need to recognize that front ends can be of benefit to themselves and patrons, and to assume the role of advisors and educators for end-users. (37 references) (CLB)

Smoldering wave-front velocity in fiberboard

Treesearch

John J. Brenden; Erwin L. Schaffer

1980-01-01

In fiberboard, the phenomena of smoldering can be visualized as decomposition resulting from the motion of a thermal wave-front through the material. The tendency to smolder is then directly proportional to the velocity of the front. Velocity measurements were made on four fiberboards and were compared to values given in the literature for several substances....

Time-delayed reaction-diffusion fronts

NASA Astrophysics Data System (ADS)

Isern, Neus; Fort, Joaquim

2009-11-01

A time-delayed second-order approximation for the front speed in reaction-dispersion systems was obtained by Fort and Méndez [Phys. Rev. Lett. 82, 867 (1999)]. Here we show that taking proper care of the effect of the time delay on the reactive process yields a different evolution equation and, therefore, an alternate equation for the front speed. We apply the new equation to the Neolithic transition. For this application the new equation yields speeds about 10% slower than the previous one.

38 CFR 1.894 - Annual goals and timetables.

Code of Federal Regulations, 2010 CFR

2010-07-01

... GENERAL PROVISIONS Part-Time Career Employment Program § 1.894 Annual goals and timetables. An departmentwide plan for promoting part-time employment opportunities will be developed annually. This plan will...

Greenland ice sheet outlet glacier front changes: comparison of year 2008 with past years

NASA Astrophysics Data System (ADS)

Decker, D. E.; Box, J.; Benson, R.

2008-12-01

NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) imagery are used to calculate inter-annual, end of summer, glacier front area changes at 10 major Greenland ice sheet outlets over the 2000-2008 period. To put the recent 8 end of summer net annual changes into a longer perspective, glacier front position information from the past century are also incorporated. The largest MODIS-era area changes are losses/retreats; found at the relatively large Petermann Gletscher, Zachariae Isstrom, and Jakobshavn Isbrae. The 2007-2008 net ice area losses were 63.4 sq. km, 21.5 sq. km, and 10.9 sq. km, respectively. Of the 10 largest Greenland glaciers surveyed, the total net cumulative area change from end of summer 2000 to 2008 is -536.6 sq km, that is, an area loss equivalent with 6.1 times the area of Manhattan Is. (87.5 sq km) in New York, USA. Ice front advances are evident in 2008; also at relatively large and productive (in terms of ice discharge) glaciers of Helheim (5.7 sq km), Store Gletscher (4.9 sq km), and Kangerdlugssuaq (3.4 sq km). The largest retreat in the 2000-2008 period was 54.2 sq km at Jakobshavn Isbrae between 2002 and 2003; associated with a floating tongue disintegration following a retreat that began in 2001 and has been associated with thinning until floatation is reached; followed by irreversible collapse. The Zachariae Isstrom pro-glacial floating ice shelf loss in 2008 appears to be part of an average ~20 sq km per year disintegration trend; with the exception of the year 2006 (6.2 sq km) advance. If the Zachariae Isstrom retreat continues, we are concerned the largest ice sheet ice stream that empties into Zachariae Isstrom will accelerate, the ice stream front freed of damming back stress, increasing the ice sheet mass budget deficit in ways that are poorly understood and could be surprisingly large. By approximating the width of the surveyed glacier frontal zones, we determine and present effective glacier normalized length (L

On the distributions of annual and seasonal daily rainfall extremes in central Arizona and their spatial variability

NASA Astrophysics Data System (ADS)

Mascaro, Giuseppe

2018-04-01

This study uses daily rainfall records of a dense network of 240 gauges in central Arizona to gain insights on (i) the variability of the seasonal distributions of rainfall extremes; (ii) how the seasonal distributions affect the shape of the annual distribution; and (iii) the presence of spatial patterns and orographic control for these distributions. For this aim, recent methodological advancements in peak-over-threshold analysis and application of the Generalized Pareto Distribution (GPD) were used to assess the suitability of the GPD hypothesis and improve the estimation of its parameters, while limiting the effect of short sample sizes. The distribution of daily rainfall extremes was found to be heavy-tailed (i.e., GPD shape parameter ξ > 0) during the summer season, dominated by convective monsoonal thunderstorms. The exponential distribution (a special case of GPD with ξ = 0) was instead showed to be appropriate for modeling wintertime daily rainfall extremes, mainly caused by cold fronts transported by westerly flow. The annual distribution exhibited a mixed behavior, with lighter upper tails than those found in summer. A hybrid model mixing the two seasonal distributions was demonstrated capable of reproducing the annual distribution. Organized spatial patterns, mainly controlled by elevation, were observed for the GPD scale parameter, while ξ did not show any clear control of location or orography. The quantiles returned by the GPD were found to be very similar to those provided by the National Oceanic and Atmospheric Administration (NOAA) Atlas 14, which used the Generalized Extreme Value (GEV) distribution. Results of this work are useful to improve statistical modeling of daily rainfall extremes at high spatial resolution and provide diagnostic tools for assessing the ability of climate models to simulate extreme events.

The establishment of the Croatian Dental Crops: the front-line experience of a dentist volunteer.

PubMed

Jelaca-Bagić, S; Sipina, J; Visković, R; Cakarun, Z; Vlatković, I; Biloglav, D

1997-01-01

The establishment of the first dental office of the Croatian Dental Corps (CDC) in the city of Zadar represented at the same time the beginning of the CDC. This article describes the front-line experience of a dentist who volunteered to provide basic medical help, which eventually laid the groundwork for providing general dental care and establishing the first CDC dental office. The office was opened on December 16, 1991, and provided general dental care except prosthetics. Although faced with numerous problems and extremely difficult conditions, the office staff completed 1,913 initial and 1,157 control checkups and performed 4,002 services by treating 12 to 16 patients per day. The main causes for emergencies were caries (59%) and endodontic complications (28%). This variety of services in the proximity of the front line is considered extensive even for advanced medical corps of modern armies.

42 CFR 419.50 - Annual review.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 3 2010-10-01 2010-10-01 false Annual review. 419.50 Section 419.50 Public Health... review. (a) General rule. Not less often than annually, CMS reviews and updates groups, relative payment... selection of representatives of providers to review (and advise CMS concerning) the clinical integrity of...

25 CFR 273.50 - Annual reporting.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 25 Indians 1 2012-04-01 2011-04-01 true Annual reporting. 273.50 Section 273.50 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR INDIAN SELF-DETERMINATION AND EDUCATION ASSISTANCE ACT PROGRAM EDUCATION CONTRACTS UNDER JOHNSON-O'MALLEY ACT General Contract Requirements § 273.50 Annual reporting. (a...

25 CFR 273.50 - Annual reporting.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 25 Indians 1 2011-04-01 2011-04-01 false Annual reporting. 273.50 Section 273.50 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR INDIAN SELF-DETERMINATION AND EDUCATION ASSISTANCE ACT PROGRAM EDUCATION CONTRACTS UNDER JOHNSON-O'MALLEY ACT General Contract Requirements § 273.50 Annual reporting. (a...

25 CFR 273.50 - Annual reporting.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Annual reporting. 273.50 Section 273.50 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR INDIAN SELF-DETERMINATION AND EDUCATION ASSISTANCE ACT PROGRAM EDUCATION CONTRACTS UNDER JOHNSON-O'MALLEY ACT General Contract Requirements § 273.50 Annual reporting. (a...

25 CFR 273.50 - Annual reporting.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 25 Indians 1 2014-04-01 2014-04-01 false Annual reporting. 273.50 Section 273.50 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR INDIAN SELF-DETERMINATION AND EDUCATION ASSISTANCE ACT PROGRAM EDUCATION CONTRACTS UNDER JOHNSON-O'MALLEY ACT General Contract Requirements § 273.50 Annual reporting. (a...

25 CFR 273.50 - Annual reporting.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 25 Indians 1 2013-04-01 2013-04-01 false Annual reporting. 273.50 Section 273.50 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR INDIAN SELF-DETERMINATION AND EDUCATION ASSISTANCE ACT PROGRAM EDUCATION CONTRACTS UNDER JOHNSON-O'MALLEY ACT General Contract Requirements § 273.50 Annual reporting. (a...

Fronts and Thermohaline Structure of the Brazil Current Confluence System

NASA Astrophysics Data System (ADS)

Severov, Dimitri

and Thermohaline Structure of the Brazil Current Confluence System (BCCS) are stud-ied from climatic data, "Marathon Exp. Leg.8, 1984"data, and two Sea surface temperature (SST) data bases: "Meteor satellite"(1989-1994) and "ds277-Reynolds" (1981-2000).The South Atlantic Central Water (SACW) is divided in two main types: tropical (TW) and subtropical water (ST). Water masses, fronts, inter-frontal and frontal zones are analysed and classified: a) the water masses: Tropical Low-Salinity Water, Tropical Surface Water, Tropical Tropospheric Water, Subtropical Low-Salinity Water, Subtropical Surface Water, Subtropical Tropospheric Water. T,S characteristics of intermediate, deep and bottom water defined by different authors are confirmed and completed; b) the Inter-frontal Zones: Tropical/Brazil Current Zone, Sub-tropical Zone and Subantarctic Zone; c) the Frontal Zones: Subtropical, Subantarctic and Polar, and d) the Fronts: Subtropical Front of the Brazil Current, Principal Subtropical Front, North Subtropical Front, Subtropical Surface Front, South Subtropical Front, Subantarctic Surface Front, Subantarctic Front and Polar Front. Several stable T-S relationships are found below the friction layer and at the Fronts. The maximum gradient of the oceanographic characteris-tics occurs at the Brazil Current Front, which can be any of the subtropical fronts, depending on season. Minimum mean depth of the pycnocline coincides with the fronts of the BCCS, indicating the paths of low-salinity shelf waters into the open ocean. D. N. Severov (a) , V. Pshennikov (b) and A.V. Remeslo (c) a -Sección Oceanologé Facultad de Ciencia, Universidad de la Republica, Igué 4225, 11400 ıa, a Montevideo, Uruguay. Tel. (598-2) 525-8618, Fax (598-2) 525-8617, mail: dima@fcien.edu.uy b -Instituto de Física, Facultad de Ciencias, Universidad de la Republica, Igué 4225, 11400 Mon-a tevideo, Uruguay, mail: seva@fisica.edu.uy c -Atlantic Research Inst. For Fisheries Oceanology (Atlant

Pinpointing chiral structures with front-back polarized neutron reflectometry.

PubMed

O'Donovan, K V; Borchers, J A; Majkrzak, C F; Hellwig, O; Fullerton, E E

2002-02-11

A new development in spin-polarized neutron reflectometry enables us to more fully characterize the nucleation and growth of buried domain walls in layered magnetic materials. We applied this technique to a thin-film exchange-spring magnet. After first measuring the reflectivity with the neutrons striking the front, we measure with the neutrons striking the back. Simultaneous fits are sensitive to the presence of spiral spin structures. The technique reveals previously unresolved features of field-dependent domain walls in exchange-spring systems and has sufficient generality to apply to a variety of magnetic systems.

42 CFR 1007.17 - Annual report.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 5 2010-10-01 2010-10-01 false Annual report. 1007.17 Section 1007.17 Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OIG AUTHORITIES STATE MEDICAID FRAUD CONTROL UNITS § 1007.17 Annual report. At least 60 days prior to the expiration of...

Light-front Ward-Takahashi identity for two-fermion systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marinho, J. A. O.; Frederico, T.; Pace, E.

We propose a three-dimensional electromagnetic current operator within light-front dynamics that satisfies a light-front Ward-Takahashi identity for two-fermion systems. The light-front current operator is obtained by a quasipotential reduction of the four-dimensional current operator and acts on the light-front valence component of bound or scattering states. A relation between the light-front valence wave function and the four-dimensional Bethe-Salpeter amplitude both for bound or scattering states is also derived, such that the matrix elements of the four-dimensional current operator can be fully recovered from the corresponding light-front ones. The light-front current operator can be perturbatively calculated through a quasipotential expansion, andmore » the divergence of the proposed current satisfies a Ward-Takahashi identity at any given order of the expansion. In the quasipotential expansion the instantaneous terms of the fermion propagator are accounted for by the effective interaction and two-body currents. We exemplify our theoretical construction in the Yukawa model in the ladder approximation, investigating in detail the current operator at the lowest nontrivial order of the quasipotential expansion of the Bethe-Salpeter equation. The explicit realization of the light-front form of the Ward-Takahashi identity is verified. We also show the relevance of instantaneous terms and of the pair contribution to the two-body current and the Ward-Takahashi identity.« less

12 CFR 325.204 - Annual stress tests required.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Annual stress tests required. 325.204 Section... POLICY CAPITAL MAINTENANCE Annual Stress Test § 325.204 Annual stress tests required. (a) General... conduct a stress test on or before March 31 of each calendar year based on financial data as of September...

12 CFR 325.204 - Annual stress tests required.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Annual stress tests required. 325.204 Section... POLICY CAPITAL MAINTENANCE Annual Stress Test § 325.204 Annual stress tests required. (a) General... conduct a stress test on or before March 31 of each calendar year based on financial data as of September...

12th Annual ALS Users' Association Meeting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robinson, Arthur L.

1999-12-17

Science took the front seat as 219 Advanced Light Source (ALS) users and staff gathered on Monday and Tuesday, October 18 and 19 for the twelfth annual users' meeting. The bulk of the meeting was dedicated to reports on science at the ALS. Packed into two busy days were 31 invited oral presentations and 80 submitted poster presentations, as well as time to visit 24 vendor booths. The oral sessions were dedicated to environmental science, chemical dynamics, biosciences, magnetic materials, and atomic and molecular science. In addition, there was an ALS highlights session that emphasized new results and a sessionmore » comprising highlights from the young scientists who will carry the ALS into the future.« less

Identifying Lagrangian fronts with favourable fishery conditions

NASA Astrophysics Data System (ADS)

Prants, S. V.; Budyansky, M. V.; Uleysky, M. Yu.

2014-08-01

Lagrangian fronts (LFs) in the ocean are defined as boundaries between surface waters with strongly different Lagrangian properties. They can be accurately detected in a given velocity field by computing synoptic maps for displacements of synthetic tracers and other Lagrangian 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.

Mesopelagic fish assemblages across oceanic fronts: A comparison of three frontal systems in the southern California Current Ecosystem

NASA Astrophysics Data System (ADS)

Netburn, Amanda N.; Koslow, J. Anthony

2018-04-01

With strong horizontal gradients in physical properties, oceanic frontal regions can lead to disproportionately high biological productivity. We examined cross-frontal changes in mesopelagic fish assemblages at three separate frontal systems in the southern California Current Ecosystem (CCE) as part of the CCE Long Term Ecological Research program: the A-Front sampled in October 2008, the C-Front in June/July 2011, and the E-Front in July/August 2012. We analyzed the differential effects of front-associated regions on density and species composition of adult migratory and non-migratory fishes and larvae, and the larval to adult ratio (as a possible index of a population growth potential) for migratory and non-migratory species. The fronts did not have a strong effect on densities of any subset of the mesopelagic fish assemblage. The species composition of the vertical migratory fishes (and their larvae) was typically altered across fronts, with different assemblages present on either side of each front. The migratory assemblages at the fronts themselves were indistinguishable from those at the more productive side of the frontal system. In contrast, the assemblage composition of the non-migratory fishes was indistinguishable between regions across all three of the fronts. The differences between the Northern and Southern assemblages at the A-Front were primarily based on biogeographic provinces, while the assemblages at the E-Front were largely distinguishable by their oceanic or coastal-upwelling zone associations. These results generally confirm those of previous studies on frontal systems in the California Current Ecosystem and elsewhere. The ratio of larvae to adults, a potential index of population growth potential, was altered across two of the fronts for migratory species, elevated on the colder side of the A-Front and the warmer side of the E-Front. This finding suggests that fronts may be regions of enhanced reproduction. The larvae to adult ratio was

Rigorous results for the minimal speed of Kolmogorov-Petrovskii-Piscounov monotonic fronts with a cutoffa)

NASA Astrophysics Data System (ADS)

Benguria, Rafael D.; Depassier, M. Cristina; Loss, Michael

2012-12-01

We study the effect of a cutoff on the speed of pulled fronts of the one-dimensional reaction diffusion equation. To accomplish this, we first use variational techniques to prove the existence of a heteroclinic orbit in phase space for traveling wave solutions of the corresponding reaction diffusion equation under conditions that include discontinuous reaction profiles. This existence result allows us to prove rigorous upper and lower bounds on the minimal speed of monotonic fronts in terms of the cut-off parameter ɛ. From these bounds we estimate the range of validity of the Brunet-Derrida formula for a general class of reaction terms.

28 CFR 69.605 - Inspector General report.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Inspector General report. 69.605 Section... Reports § 69.605 Inspector General report. (a) The Inspector General, or other official as specified in...

43 CFR 18.605 - Inspector General report.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Inspector General report. 18.605 Section... Agency Reports § 18.605 Inspector General report. (a) The Inspector General, or other official as...

13 CFR 146.605 - Inspector General report.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Inspector General report. 146.605... Agency Reports § 146.605 Inspector General report. (a) The Inspector General, or other official as...

15 CFR 28.605 - Inspector General report.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Inspector General report. 28.605... Agency Reports § 28.605 Inspector General report. (a) The Inspector General, or other official as...

15 CFR 28.605 - Inspector General report.

Code of Federal Regulations, 2010 CFR

2010-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Inspector General report. 28.605... Agency Reports § 28.605 Inspector General report. (a) The Inspector General, or other official as...

15 CFR 28.605 - Inspector General report.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Inspector General report. 28.605... Agency Reports § 28.605 Inspector General report. (a) The Inspector General, or other official as...

13 CFR 146.605 - Inspector General report.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Inspector General report. 146.605... Agency Reports § 146.605 Inspector General report. (a) The Inspector General, or other official as...

28 CFR 69.605 - Inspector General report.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Inspector General report. 69.605 Section... Reports § 69.605 Inspector General report. (a) The Inspector General, or other official as specified in...

43 CFR 18.605 - Inspector General report.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Inspector General report. 18.605 Section... Agency Reports § 18.605 Inspector General report. (a) The Inspector General, or other official as...

15 CFR 28.605 - Inspector General report.

Code of Federal Regulations, 2013 CFR

2013-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Inspector General report. 28.605... Agency Reports § 28.605 Inspector General report. (a) The Inspector General, or other official as...

43 CFR 18.605 - Inspector General report.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Inspector General report. 18.605 Section... Agency Reports § 18.605 Inspector General report. (a) The Inspector General, or other official as...

13 CFR 146.605 - Inspector General report.

Code of Federal Regulations, 2010 CFR

2010-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Inspector General report. 146.605... Agency Reports § 146.605 Inspector General report. (a) The Inspector General, or other official as...

28 CFR 69.605 - Inspector General report.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Inspector General report. 69.605 Section... Reports § 69.605 Inspector General report. (a) The Inspector General, or other official as specified in...

28 CFR 69.605 - Inspector General report.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Inspector General report. 69.605 Section... Reports § 69.605 Inspector General report. (a) The Inspector General, or other official as specified in...

43 CFR 18.605 - Inspector General report.

Code of Federal Regulations, 2013 CFR

2013-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Inspector General report. 18.605 Section... Agency Reports § 18.605 Inspector General report. (a) The Inspector General, or other official as...

13 CFR 146.605 - Inspector General report.

Code of Federal Regulations, 2013 CFR

2013-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Inspector General report. 146.605... Agency Reports § 146.605 Inspector General report. (a) The Inspector General, or other official as...

28 CFR 69.605 - Inspector General report.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Inspector General report. 69.605 Section... Reports § 69.605 Inspector General report. (a) The Inspector General, or other official as specified in...

15 CFR 28.605 - Inspector General report.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Inspector General report. 28.605... Agency Reports § 28.605 Inspector General report. (a) The Inspector General, or other official as...

13 CFR 146.605 - Inspector General report.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Inspector General report. 146.605... Agency Reports § 146.605 Inspector General report. (a) The Inspector General, or other official as...

Fronts and frontogenesis as revealed by high time resolution data

NASA Technical Reports Server (NTRS)

Frank, A. E.; Barber, D. A.

1977-01-01

Upper air sounding are used to examine a cold front of average intensity. Vertical cross sections of potential temperature and wind, and horizontal analyses were compared and adjusted for consistency. These analyses were then used to study the evolution of the front, found to consist of a complex system of fronts occurring at all levels of the troposphere. Low level fronts were strongest at the surface and rapidly weakened with height. Fronts in the midddle troposphere were much more intense. The warm air ahead of the fronts was nearly barotropic, while the cold air behind was baroclinic through deep layers. A deep mixed layer was observed to grow in this cold air.

Rossby waves, extreme fronts, and wildfires in southeastern Australia

NASA Astrophysics Data System (ADS)

Reeder, Michael J.; Spengler, Thomas; Musgrave, Ruth

2015-03-01

The most catastrophic fires in recent history in southern Australia have been associated with extreme cold fronts. Here an extreme cold front is defined as one for which the maximum temperature at 2 m is at least 17°C lower on the day following the front. An anticyclone, which precedes the cold front, directs very dry northerlies or northwesterlies from the interior of the continent across the region. The passage of the cold front is followed by strong southerlies or southwesterlies. European Centre for Medium-Range Weather Forecasts ERA-Interim Reanalyses show that this regional synoptic pattern common to all strong cold fronts, and hence severe fire conditions, is a consequence of propagating Rossby waves, which grow to large amplitude and eventually irreversibly overturn. The process of overturning produces the low-level anticyclone and dry conditions over southern Australia, while simultaneously producing an upper level trough and often precipitation in northeastern Australia.

Observations of a tidal intrusion front in a tidal channel

NASA Astrophysics Data System (ADS)

Lu, Shasha; Xia, Xiaoming; Thompson, Charlie E. L.; Cao, Zhenyi; Liu, Yifei

2017-11-01

A visible front indicated by a surface colour change, and sometimes associated with foam or debris lines, was observed in a tidal channel during neap tide. This is an example of a tidal intrusion front occurring in the absence of sudden topographical changes or reversing flows, typically reported to be associated with such fronts. Detailed Acoustic Doppler Current Profiler and conductivity/temperature/depth measurements were taken on repeated transects both with fronts apparent and with fronts absent. The results indicated that the front occurred as a result of stratification, which was sustained by the buoyancy flux and the weak tide-induced mixing during neap ebb tide. The stronger tide-induced mixing during spring tide restrained stratification, leading to the absence of a front. The mechanism of the frontogenesis was the density gradient between the stratified water formed during neap ebb tide, and the more mixed seawater during neap flood tide; thus, the water on the landward (southwestern) side of the front was stratified, and that on the seaward side (northeastern) of the front was vertically well mixed. Gradient Richardson number estimates suggest that the flow between the stratified and mixed water was near the threshold 0.25 for shear instability. Meanwhile, the density gradient would provide an initial baroclinic contribution to velocity convergence, which is indicated by the accumulation of buoyant matter such as foam, grass, and debris into a sharply defined line along the surface. The front migrates with the flood current, with a local maximum towards the eastern side of the channel, leading to an asymmetrical shape with the eastern side of the front driven further into the Tiaozhoumen tidal channel.

45 CFR 93.605 - Inspector General report.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 45 Public Welfare 1 2010-10-01 2010-10-01 false Inspector General report. 93.605 Section 93.605... LOBBYING Agency Reports § 93.605 Inspector General report. (a) The Inspector General, or other official as...

43 CFR 18.605 - Inspector General report.

Code of Federal Regulations, 2012 CFR

2012-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Inspector General report. 18.605 Section 18... Reports § 18.605 Inspector General report. (a) The Inspector General, or other official as specified in...

12 CFR 411.605 - Inspector General report.

Code of Federal Regulations, 2013 CFR

2013-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Inspector General report. 411.605 Section 411... Reports § 411.605 Inspector General report. (a) The Inspector General, or other official as specified in...

45 CFR 93.605 - Inspector General report.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 45 Public Welfare 1 2011-10-01 2011-10-01 false Inspector General report. 93.605 Section 93.605... LOBBYING Agency Reports § 93.605 Inspector General report. (a) The Inspector General, or other official as...

45 CFR 93.605 - Inspector General report.

Code of Federal Regulations, 2013 CFR

2013-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 45 Public Welfare 1 2013-10-01 2013-10-01 false Inspector General report. 93.605 Section 93.605... LOBBYING Agency Reports § 93.605 Inspector General report. (a) The Inspector General, or other official as...

12 CFR 411.605 - Inspector General report.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Inspector General report. 411.605 Section 411... Reports § 411.605 Inspector General report. (a) The Inspector General, or other official as specified in...

45 CFR 93.605 - Inspector General report.

Code of Federal Regulations, 2012 CFR

2012-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 45 Public Welfare 1 2012-10-01 2012-10-01 false Inspector General report. 93.605 Section 93.605... LOBBYING Agency Reports § 93.605 Inspector General report. (a) The Inspector General, or other official as...

31 CFR 21.605 - Inspector General report.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Inspector General report. 21.605... LOBBYING Agency Reports § 21.605 Inspector General report. (a) The Inspector General, or other official as...

31 CFR 21.605 - Inspector General report.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Inspector General report. 21.605... LOBBYING Agency Reports § 21.605 Inspector General report. (a) The Inspector General, or other official as...

31 CFR 21.605 - Inspector General report.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Inspector General report. 21.605... LOBBYING Agency Reports § 21.605 Inspector General report. (a) The Inspector General, or other official as...

12 CFR 411.605 - Inspector General report.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Inspector General report. 411.605 Section 411... Reports § 411.605 Inspector General report. (a) The Inspector General, or other official as specified in...

12 CFR 411.605 - Inspector General report.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 12 Banks and Banking 4 2011-01-01 2011-01-01 false Inspector General report. 411.605 Section 411... Reports § 411.605 Inspector General report. (a) The Inspector General, or other official as specified in...

12 CFR 411.605 - Inspector General report.

Code of Federal Regulations, 2010 CFR

2010-01-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Inspector General report. 411.605 Section 411... Reports § 411.605 Inspector General report. (a) The Inspector General, or other official as specified in...

31 CFR 21.605 - Inspector General report.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Inspector General report. 21.605... LOBBYING Agency Reports § 21.605 Inspector General report. (a) The Inspector General, or other official as...

45 CFR 93.605 - Inspector General report.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 45 Public Welfare 1 2014-10-01 2014-10-01 false Inspector General report. 93.605 Section 93.605... LOBBYING Agency Reports § 93.605 Inspector General report. (a) The Inspector General, or other official as...

31 CFR 21.605 - Inspector General report.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Inspector General report. 21.605... LOBBYING Agency Reports § 21.605 Inspector General report. (a) The Inspector General, or other official as...

From the front

DOE Office of Scientific and Technical Information (OSTI.GOV)

Price, Stephen

The causes of recent dynamic thinning of Greenland's outlet glaciers have been debated. Realistic simulations suggest that changes at the marine fronts of these glaciers are to blame, implying that dynamic thinning will cease once the glaciers retreat to higher ground. For the last decade, many outlet glaciers in Greenland that terminate in the ocean have accelerated, thinned, and retreated. To explain these dynamic changes, two hypotheses have been discussed. Atmospheric warming has increased surface melting and may also have increased the amount of meltwater reaching the glacier bed, increasing lubrication at the base and hence the rate of glaciermore » sliding. Alternatively, a change in the delicate balance of forces where the glacier fronts meet the ocean could trigger the changes. Faezeh Nick and colleagues5 present ice-sheet modeling experiments that mimic the observations on Helheim glacier, East Greenland, and suggest that the dynamic behaviour of outlet glaciers follows from perturbations at their marine fronts. Greenland's ice sheet loses mass partly through surface melting and partly through fast flowing outlet glaciers that connect the vast plateau of inland ice with the ocean. Earlier ice sheet models have failed to reproduce the dynamic variability exhibited by ice sheets over time. It has therefore not been possible to distinguish with confidence between basal lubrication from surface meltwater and changes at the glaciers' marine fronts as causes for the observed changes on Greenland's outlet glaciers. But this distinction bears directly on future sea-level rise, the raison d'etre of much of modern-day glaciology: If the recent dynamic mass loss Greenland's outlet glaciers is linked to changing atmospheric temperatures, it may continue for as long as temperatures continue to increase. On the other hand, if the source of the dynamic mass loss is a perturbation at the ice-ocean boundary, these glaciers will lose contact with that perturbation after

Circumpolar variation in morphological characteristics of Greater White-fronted Geese Anser albifrons

USGS Publications Warehouse

Ely, Craig R.; Fox, A.D.; Alisauskas, R.T.; Andreev, A.; Bromley, R.G.; Degtyarev, Andrei G.; Ebbinge, B.; Gurtovaya, E.N.; Kerbes, R.; Kondratyev, Alexander V.; Kostin, I.; Krechmar, A.V.; Litvin, K.E.; Miyabayashi, Y.; Moou, J.H.; Oates, R.M.; Orthmeyer, D.L.; Sabano, Yutaka; Simpson, S.G.; Solovieva, D.V.; Spindler, Michael A.; Syroechkovsky, Y.V.; Takekawa, John Y.; Walsh, A.

2005-01-01

Capsule: Greater White-fronted Geese show significant variation in body size from sampling locations throughout their circumpolar breeding range. Aims: To determine the degree of geographical variation in body size of Greater White-fronted Geese and identify factors contributing to any apparent patterns in variation. Methods: Structural measures of >3000 geese from 16 breeding areas throughout the Holarctic breeding range of the species were compared statistically. Results: Palearctic forms varied clinally, and increased in size from the smallest forms on the Kanin and Taimyr peninsulas in western Eurasia to the largest forms breeding in the Anadyr Lowlands of eastern Chukotka. Clinal variation was less apparent in the Nearctic, as both the smallest form in the Nearctic and the largest form overall (the Tule Goose) were from different breeding areas in Alaska. The Tule Goose was 25% larger than the smallest form. Birds from Greenland (A. a. flavirostris) were the second largest, although only slightly larger than geese from several North American populations. Body size was not correlated with breeding latitude but was positively correlated with temperature on the breeding grounds, breeding habitat, and migration distance. Body mass of Greater White-fronted Geese from all populations remained relatively constant during the period of wing moult. Morphological distinctness of eastern and western Palearctic forms concurs with earlier findings of complete range disjunction. Conclusions: Patterns of morphological variation in Greater White-fronted Geese across the Holarctic can be generally attributed to adaptation to variable breeding environments, migration requirements, and phylo-geographical histories. 

Front dynamics and entanglement in the XXZ chain with a gradient

NASA Astrophysics Data System (ADS)

Eisler, Viktor; Bauernfeind, Daniel

2017-11-01

We consider the XXZ spin chain with a magnetic field gradient and study the profiles of the magnetization as well as the entanglement entropy. For a slowly varying field, it is shown that, by means of a local density approximation, the ground-state magnetization profile can be obtained with standard Bethe ansatz techniques. Furthermore, it is argued that the low-energy description of the theory is given by a Luttinger liquid with slowly varying parameters. This allows us to obtain a very good approximation of the entanglement profile using a recently introduced technique of conformal field theory in curved spacetime. Finally, the front dynamics is also studied after the gradient field has been switched off, following arguments of generalized hydrodynamics for integrable systems. While for the XX chain the hydrodynamic solution can be found analytically, the XXZ case appears to be more complicated and the magnetization profiles are recovered only around the edge of the front via an approximate numerical solution.

Comparative cervical profiles of adult and under-18 front-row rugby players: implications for playing policy.

PubMed

Hamilton, D F; Gatherer, D; Robson, J; Graham, N; Rennie, N; Maclean, J G B; Simpson, A H R W

2014-05-05

To compare the cervical isometric strength, fatigue endurance and range of motion of adult and under-18 age-grade front-row rugby players to inform the development of a safe age group policy with particular reference to scrummaging. Cross-sectional cohort study. 'Field testing' at Murrayfield stadium. 30 high-performance under-18 players and 22 adult front-row rugby players. Isometric neck strength, height, weight and grip strength. Youth players demonstrated the same height and grip strength as the adult players; however, the adults were significantly heavier and demonstrated substantially greater isometric strength (p<0.001). Only two of the 'elite' younger players could match the adult mean cervical isometric strength value. In contrast to school age players in general, grip strength was poorly associated with neck strength (r=0.2) in front-row players; instead, player weight (r=0.4) and the number of years' experience of playing in the front row (r=0.5) were the only relevant factors in multivariate modelling of cervical strength (R(2)=0.3). Extreme forces are generated between opposing front rows in the scrum and avoidance of mismatch is important if the risk of injury is to be minimised. Although elite youth front-row rugby players demonstrate the same peripheral strength as their adult counterparts on grip testing, the adults demonstrate significantly greater cervical strength. If older youths and adults are to play together, such findings have to be noted in the development of age group policies with particular reference to the scrum.

Comparative cervical profiles of adult and under-18 front-row rugby players: implications for playing policy

PubMed Central

Hamilton, D F; Gatherer, D; Robson, J; Graham, N; Rennie, N; MacLean, J G B; Simpson, A H R W

2014-01-01

Objective To compare the cervical isometric strength, fatigue endurance and range of motion of adult and under-18 age-grade front-row rugby players to inform the development of a safe age group policy with particular reference to scrummaging. Design Cross-sectional cohort study. Setting ‘Field testing’ at Murrayfield stadium. Participants 30 high-performance under-18 players and 22 adult front-row rugby players. Outcome measures Isometric neck strength, height, weight and grip strength. Results Youth players demonstrated the same height and grip strength as the adult players; however, the adults were significantly heavier and demonstrated substantially greater isometric strength (p<0.001). Only two of the ‘elite’ younger players could match the adult mean cervical isometric strength value. In contrast to school age players in general, grip strength was poorly associated with neck strength (r=0.2) in front-row players; instead, player weight (r=0.4) and the number of years’ experience of playing in the front row (r=0.5) were the only relevant factors in multivariate modelling of cervical strength (R2=0.3). Conclusions Extreme forces are generated between opposing front rows in the scrum and avoidance of mismatch is important if the risk of injury is to be minimised. Although elite youth front-row rugby players demonstrate the same peripheral strength as their adult counterparts on grip testing, the adults demonstrate significantly greater cervical strength. If older youths and adults are to play together, such findings have to be noted in the development of age group policies with particular reference to the scrum. PMID:24797427

Design Performance of Front Steering-Type Electron Cyclotron Launcher for ITER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takahashi, K.; Imai, T.; Kobayashi, N.

2005-01-15

The performance of a front steering (FS)-type electron cyclotron launcher designed for the International Thermonuclear Experimental Reactor (ITER) is evaluated with a thermal, electromagnetic, and nuclear analysis of the components; a mechanical test of a spiral tube for the steering mirror; and a rotational test of bearings. The launcher consists of a front shield and a launcher plug where three movable optic mirrors to steer incident multimegawatt radio-frequency beam power, waveguide components, nuclear shields, and vacuum windows are installed. The windows are located behind a closure plate to isolate the transmission lines from the radioactivated circumstance (vacuum vessel). The waveguidemore » lines of the launcher are doglegged to reduce the direct neutron streaming toward the vacuum windows and other components. The maximum stresses on the critical components such as the steering mirror, its cooling tube, and the front shield are less than their allowable stresses. It was also identified that the stress on the launcher, which yielded from electromagnetic force caused by plasma disruption, was a little larger than the criteria, and a modification of the launcher plug structure was necessary. The nuclear analysis result shows that the neutron shield capability of the launcher satisfies the shield criteria of the ITER. It concludes that the design of the FS launcher is generally suitable for application to the ITER.« less

Bathymetrically controlled velocity-shear front at a tidal river confluence

NASA Astrophysics Data System (ADS)

Blain, Cheryl Ann; Mied, Richard P.; McKay, Paul; Chen, Wei; Rhea, W. Joseph

2015-08-01

Nonbuoyant front formation at the confluence of Nanjemoy Creek and the main Potomac River (MD) channel is examined. Terra satellite ASTER imagery reveals a sediment color front emerging from Nanjemoy Creek when the Potomac is near maximum ebb. Nearly contemporaneous ASTER and Landsat ETM+ imagery are used to extract surface velocities, which suggest a velocity shear front is collocated with the color front. In situ velocities (measured by RiverRay traverses near the Nanjemoy Creek mouth) confirm the shear front's presence. A finite-element simulation (using ADCIRC) replicates the observed velocity-shear front and is applied to decipher its physics. Three results emerge: (1) the velocity-shear front forms, confined to a shoal downstream of the creek-river confluence for most of the tidal cycle, (2) a simulation with a flat bottom in Nanjemoy Creek and Potomac River (i.e., no bathymetry variation) indicates the velocity-shear front never forms, hence the front cannot exist without the bathymetry, and (3) an additional simulation with a blocked-off Creek entrance demonstrates that while the magnitude of the velocity shear is largely unchanged without the creek, shear front formation is delayed in time. Without the Creek, there is no advection of the M6 tidal constituent (generated by nonlinear interaction of the flow with bottom friction) onto the shoals, only a locally generated contribution. A tidal phase difference between Nanjemoy and Potomac causes the ebbing Nanjemoy Creek waters to intrude into the Potomac as far south as its deep channel, and draw from a similar location in the Potomac during Nanjemoy flood.

Relativistic bound-state problem in the light-front Yukawa model

NASA Astrophysics Data System (ADS)

Głazek, Stanisław; Harindranath, Avaroth; Pinsky, Stephen; Shigemitsu, Junko; Wilson, Kenneth

1993-02-01

We study the renormalization problem on the light front for the two-fermion bound state in the (3+1)-dimensional Yukawa model, working within the lowest-order Tamm-Dancoff approximation. In addition to traditional mass and wave-function renormalization, new types of counterterms are required. These are nonlocal and involve arbitrary functions of the longitudinal momenta. Their appearance is consistent with general power-counting arguments on the light front. We estimate the ``arbitrary function'' in two ways: (1) by using perturbation theory as a guide and (2) by considering the asymptotic large transverse momentum behavior of the kernel in the bound-state equations. The latter method, as it is currently implemented, is applicable only to the helicity-zero sector of the theory. Because of triviality, in the Yukawa model one must retain a finite cutoff Λ in order to have a nonvanishing renormalized coupling. For the range of renormalized couplings (and cutoffs) allowed by triviality, one finds that the perturbative counterterm does a good job in eliminating cutoff dependence in the low-energy spectrum (masses <<Λ).

Firing up the front line.

PubMed

Katzenbach, J R; Santamaria, J A

1999-01-01

For many organizations, achieving competitive advantage means eliciting superior performance from employees on the front line--the burger flippers, hotel room cleaners, and baggage handlers whose work has an enormous effect on customers. That's no easy task. Front line workers are paid low wages, have scant hope of advancement, and--not surprisingly--often care little about the company's performance. But then how do some companies succeed in engaging the emotional energy of rank-and-file workers? A team of researchers at McKinsey & Company and the Conference Board recently explored that question and discovered that one highly effective route is demonstrated by the U.S. Marine Corps. The Marines' approach to motivation follows the "mission, values, and pride" path, which researchers say is practical and relevant for the business world. More specifically, the authors say the Marines follow five practices: they over-invest in cultivating core value; prepare every person to lead, including front line supervisors; learn when to create teams and when to create single-leader work groups; attend to all employees, not just the top half; and encourage self-discipline as a way of building pride. The authors admit there are critical differences between the Marines and most businesses. But using vivid examples from companies such as KFC and Marriott International, the authors illustrate how the Marines' approach can be translated for corporate use. Sometimes, the authors maintain, minor changes in a company's standard operating procedure can have a powerful effect on front line pride and can result in substantial payoffs in company performance.

12 CFR 332.5 - Annual privacy notice to customers required.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Annual privacy notice to customers required... OF GENERAL POLICY PRIVACY OF CONSUMER FINANCIAL INFORMATION Privacy and Opt Out Notices § 332.5 Annual privacy notice to customers required. (a)(1) General rule. You must provide a clear and...

47 CFR 61.43 - Annual price cap filings required.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Annual price cap filings required. 61.43... (CONTINUED) TARIFFS General Rules for Dominant Carriers § 61.43 Annual price cap filings required. Carriers subject to price cap regulation shall submit annual price cap tariff filings that propose rates for the...

An Investigation of Generalized Differential Evolution Metaheuristic for Multiobjective Optimal Crop-Mix Planning Decision

PubMed Central

Olugbara, Oludayo

2014-01-01

This paper presents an annual multiobjective crop-mix planning as a problem of concurrent maximization of net profit and maximization of crop production to determine an optimal cropping pattern. The optimal crop production in a particular planting season is a crucial decision making task from the perspectives of economic management and sustainable agriculture. A multiobjective optimal crop-mix problem is formulated and solved using the generalized differential evolution 3 (GDE3) metaheuristic to generate a globally optimal solution. The performance of the GDE3 metaheuristic is investigated by comparing its results with the results obtained using epsilon constrained and nondominated sorting genetic algorithms—being two representatives of state-of-the-art in evolutionary optimization. The performance metrics of additive epsilon, generational distance, inverted generational distance, and spacing are considered to establish the comparability. In addition, a graphical comparison with respect to the true Pareto front for the multiobjective optimal crop-mix planning problem is presented. Empirical results generally show GDE3 to be a viable alternative tool for solving a multiobjective optimal crop-mix planning problem. PMID:24883369

An investigation of generalized differential evolution metaheuristic for multiobjective optimal crop-mix planning decision.

PubMed

Adekanmbi, Oluwole; Olugbara, Oludayo; Adeyemo, Josiah

2014-01-01

This paper presents an annual multiobjective crop-mix planning as a problem of concurrent maximization of net profit and maximization of crop production to determine an optimal cropping pattern. The optimal crop production in a particular planting season is a crucial decision making task from the perspectives of economic management and sustainable agriculture. A multiobjective optimal crop-mix problem is formulated and solved using the generalized differential evolution 3 (GDE3) metaheuristic to generate a globally optimal solution. The performance of the GDE3 metaheuristic is investigated by comparing its results with the results obtained using epsilon constrained and nondominated sorting genetic algorithms-being two representatives of state-of-the-art in evolutionary optimization. The performance metrics of additive epsilon, generational distance, inverted generational distance, and spacing are considered to establish the comparability. In addition, a graphical comparison with respect to the true Pareto front for the multiobjective optimal crop-mix planning problem is presented. Empirical results generally show GDE3 to be a viable alternative tool for solving a multiobjective optimal crop-mix planning problem.

45 CFR 96.74 - Annual reporting requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION BLOCK GRANTS Social Services Block Grants § 96.74 Annual reporting requirements. (a) Annual report. In accordance with 42 U.S.C... Block Grant, showing separately the number of children and the number of adults who received such...

Study of the Río de la Plata turbidity front, Part 1: spatial and temporal distribution

NASA Astrophysics Data System (ADS)

Framiñan, Mariana B.; Brown, Otis B.

1996-08-01

The Río de la Plata is a riverine system located on the east coast of South America at 35°S. It covers 35,000 km 2, it is 320 km long and 230 km wide at the mouth. The Río de la Plata drains the second largest basin in South America with an average discharge of 22,000 m 3 s -1. The processes associated with the interaction of the fresh river water and the saline shelf water and tidal stirring generate a turbidity front in the outer region, which is clearly defined in the satellite images as a strong gradient in reflectance and a sharp change in water color. We use a 4 yr span of NOAA-AVHRR daily images, from September 1986 to August 1990, to determine the spatial and temporal distribution of the turbidity front. Channels 1 and 2 (visible and near-infrared) are used to digitize the fronts, and channel 4 and sea surface temperature are used as complementary information for cloud detection. From a total of 2578 images, 1274 daytime images allowed us to determine 333 positions of the front. This information is used to estimate the distribution of the frontal density, a probabilistic measure of frontal occurrence. Monthly, seasonal and annual analyses were performed. The relation of the turbidity front patterns to bathymetry, tidal dynamics, river discharge and winds were investigated. A comparison between the frontal density distribution and stratification parameters is presented. The results show a high degree of variability of the frontal distribution at the northern coast of the estuary. In this region, the frontal position varies between 57°W and 54°12'W. The westernmost location occurs in the summer months, which is coincident with minimum river discharge, predominance of easterly winds and minimum occurrence of southwesterlies. The easternmost location occurs during the spring, with strong winds from the southwest. At the southern coast the modal position of the front coincides with the 5 m isobath, although great variations to this position have been

Gust-Front and Outflow Related Waterspouts: Timely Warnings, Formation, and Impact on Public Safety

NASA Astrophysics Data System (ADS)

Cappucci, M.

2013-12-01

Massachusetts may be over a thousand miles away from the traditional "tornado alley", but as the deadly tornadoes that killed four on June 1st 2011 proved, we are not immune to such storms. Over the course of half a century or so, Massachusetts has bore witness to scores of tornadoes, including an F5 twister that touched down on June 9th 1953, resulting in the death of 94 people. Since this tornado, none other in the United States had caused as many deaths, until the Joplin, Missouri catastrophe of May 22, 2011 (161 deaths). In Massachusetts, however, storms of such destructive magnitude are generally confined to the western half of the state, as the June 1, 2011 tornadoes in South Central Massachusetts illustrated. Despite this, a recently observed trend has revealed that the eastern Massachusetts coastline may boast as many, if not more, tornadoes, albeit undocumented. On June 23rd, 2012, a strong thunderstorm produced a spectacular gust front over Boston Harbor. This gust front was associated with intense thunderstorm outflow that helped to spawn a waterspout that roared ashore in Scituate as an EF-0 tornado. This waterspout, however, developed ahead of the gust front, yet merged with the cloud structure of the outflow, hinting at a type of interaction between the thunderstorm downdraft and the waterspout. This tornado caused minor damage. A similar situation occurred in Plymouth, MA, on July 24th, when three waterspouts formed ahead of the gust front of a severe thunderstorm; one of these tempests roared ashore on White Horse Beach as an EF-0 storm, causing minor damage to the sum of a few hundred dollars. Photos taken of these spouts reveal their formation ahead of the gust front, with a downdraft/waterspout interaction similar to the situation of June 23rd. Time-lapse videography of the gust front taken moments after the dissipation of the spouts reveals a horizontally oriented vortex a few hundred meters ahead of the storm's outflow boundary. The spinning of

Inverse algorithms for 2D shallow water equations in presence of wet dry fronts: Application to flood plain dynamics

NASA Astrophysics Data System (ADS)

Monnier, J.; Couderc, F.; Dartus, D.; Larnier, K.; Madec, R.; Vila, J.-P.

2016-11-01

The 2D shallow water equations adequately model some geophysical flows with wet-dry fronts (e.g. flood plain or tidal flows); nevertheless deriving accurate, robust and conservative numerical schemes for dynamic wet-dry fronts over complex topographies remains a challenge. Furthermore for these flows, data are generally complex, multi-scale and uncertain. Robust variational inverse algorithms, providing sensitivity maps and data assimilation processes may contribute to breakthrough shallow wet-dry front dynamics modelling. The present study aims at deriving an accurate, positive and stable finite volume scheme in presence of dynamic wet-dry fronts, and some corresponding inverse computational algorithms (variational approach). The schemes and algorithms are assessed on classical and original benchmarks plus a real flood plain test case (Lèze river, France). Original sensitivity maps with respect to the (friction, topography) pair are performed and discussed. The identification of inflow discharges (time series) or friction coefficients (spatially distributed parameters) demonstrate the algorithms efficiency.

Flame front propagation in a channel with porous walls

NASA Astrophysics Data System (ADS)

Golovastov, S. V.; Bivol, G. Yu

2016-11-01

Propagation of the detonation front in hydrogen-air mixture was investigated in rectangular cross-section channels with sound-absorbing boundaries. The front of luminescence was detected in a channel with acoustically absorbing walls as opposed to a channel with solid walls. Flame dynamics was recorded using a high-speed camera. The flame was observed to have a V-shaped profile in the acoustically absorbing section. The possible reason for the formation of the V-shaped flame front is friction under the surface due to open pores. In these shear flows, the kinetic energy of the flow on the surface can be easily converted into heat. A relatively small disturbance may eventually lead to significant local stretching of the flame front surface. Trajectories of the flame front along the axis and the boundary are presented for solid and porous surfaces.

Safer passenger car front shapes for pedestrians: A computational approach to reduce overall pedestrian injury risk in realistic impact scenarios.

PubMed

Li, Guibing; Yang, Jikuang; Simms, Ciaran

2017-03-01

Vehicle front shape has a significant influence on pedestrian injuries and the optimal design for overall pedestrian protection remains an elusive goal, especially considering the variability of vehicle-to-pedestrian accident scenarios. Therefore this study aims to develop and evaluate an efficient framework for vehicle front shape optimization for pedestrian protection accounting for the broad range of real world impact scenarios and their distributions in recent accident data. Firstly, a framework for vehicle front shape optimization for pedestrian protection was developed based on coupling of multi-body simulations and a genetic algorithm. This framework was then applied for optimizing passenger car front shape for pedestrian protection, and its predictions were evaluated using accident data and kinematic analyses. The results indicate that the optimization shows a good convergence and predictions of the optimization framework are corroborated when compared to the available accident data, and the optimization framework can distinguish 'good' and 'poor' vehicle front shapes for pedestrian safety. Thus, it is feasible and reliable to use the optimization framework for vehicle front shape optimization for reducing overall pedestrian injury risk. The results also show the importance of considering the broad range of impact scenarios in vehicle front shape optimization. A safe passenger car for overall pedestrian protection should have a wide and flat bumper (covering pedestrians' legs from the lower leg up to the shaft of the upper leg with generally even contacts), a bonnet leading edge height around 750mm, a short bonnet (<800mm) with a shallow or steep angle (either >17° or <12°) and a shallow windscreen (≤30°). Sensitivity studies based on simulations at the population level indicate that the demands for a safe passenger car front shape for head and leg protection are generally consistent, but partially conflict with pelvis protection. In particular, both

Idaho National Laboratory PCB Annual Document Log and Annual Records Report for Calendar Year 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

no name on report

The requirements for the reporting of polychlorinated biphenyl (PCB)-related activities are found in 40 Code of Federal Regulations (CFR) 761 Subpart J, "General Records and Reports." The PCB Annual Document Log is a detailed record of the PCB waste handling activities at the facility. The facility must prepare it each year by July 1 and maintain it at the facility for at least 3 years after the facility ceases using or storing PCBs and PCB items. While submittal of the PCB Annual Document Log to the U.S. Environmental Protection Agency (EPA) is not required by regulation, EPA has verbally requestedmore » in telephone conversations that this report be submitted to them on an annual basis. The Annual Document Log section of this report meets the requirements of 40 CFR 761.180(a)(2), as applicable, while the Annual Records section meets the requirement of 40 CFR 761.180(a)(1).« less

Convective instabilities in traveling fronts of addition polymerization

NASA Technical Reports Server (NTRS)

Pojman, John A.; Jones, Chris E.; Khan, Akhtar M.

1993-01-01

An autocatalytic reaction in an unstirred vessel can support a constant velocity wavefront resulting from the coupling of diffusion to the chemical reaction. A flare front is a common example in which heat is the autocatalytic species that diffuses into unreacted regions stimulating a reaction that produces more heat. Traveling fronts were studied in synthetic polymerization reactions under high pressure by workers in the former USSR. More recently, propagating fronts of methacrylic acid polymerization were studied under ambient conditions, both with video techniques and by NMR.

Bioconvection and front formation of Paramecium tetraurelia

NASA Astrophysics Data System (ADS)

Kitsunezaki, So; Komori, Rie; Harumoto, Terue

2007-10-01

We have investigated the bioconvection of Paramecium tetraurelia in high-density suspensions made by centrifugal concentration. When a suspension is kept at rest in a Hele-Shaw cell, a crowded front of paramecia is formed in the vicinity of the bottom and it propagates gradually toward the water-air interface. Fluid convection occurs under this front, and it is driven persistently by the upward swimming of paramecia. The roll structures of the bioconvection become turbulent with an increase in the depth of the suspension; they also change rapidly as the density of paramecia increases. Our experimental results suggest that lack of oxygen in the suspension causes the active individual motions of paramecia to induce the formation of this front.

Finite-time barriers to reaction front propagation

NASA Astrophysics Data System (ADS)

Locke, Rory; Mahoney, John; Mitchell, Kevin

2015-11-01

Front propagation in advection-reaction-diffusion systems gives rise to rich geometric patterns. It has been shown for time-independent and time-periodic fluid flows that invariant manifolds, termed burning invariant manifolds (BIMs), serve as one-sided dynamical barriers to the propagation of reaction front. More recently, theoretical work has suggested that one-sided barriers, termed burning Lagrangian Coherent structures (bLCSs), exist for fluid velocity data prescribed over a finite time interval, with no assumption on the time-dependence of the flow. In this presentation, we use a time-varying fluid ``wind'' in a double-vortex channel flow to demonstrate that bLCSs form the (locally) most attracting or repelling fronts.

Optimal back-to-front airplane boarding.

PubMed

Bachmat, Eitan; Khachaturov, Vassilii; Kuperman, Ran

2013-06-01

The problem of finding an optimal back-to-front airplane boarding policy is explored, using a mathematical model that is related to the 1+1 polynuclear growth model with concave boundary conditions and to causal sets in gravity. We study all airplane configurations and boarding group sizes. Optimal boarding policies for various airplane configurations are presented. Detailed calculations are provided along with simulations that support the main conclusions of the theory. We show that the effectiveness of back-to-front policies undergoes a phase transition when passing from lightly congested airplanes to heavily congested airplanes. The phase transition also affects the nature of the optimal or near-optimal policies. Under what we consider to be realistic conditions, optimal back-to-front policies lead to a modest 8-12% improvement in boarding time over random (no policy) boarding, using two boarding groups. Having more than two groups is not effective.

Turbulence spectra measured during fire front passage

Treesearch

Daisuke Seto; Craig B. Clements; Warren E. Heilman

2013-01-01

Four field experiments were conducted over various fuel and terrain to investigate turbulence generation during the passage of wildland fire fronts. Our results indicate an increase in horizontal mean winds and friction velocity, horizontal and vertical velocity variances as well as a decreased degree of anisotropy in TKE during fire front passage (FFP) due to fire-...

Reaction fronts of the autocatalytic hydrogenase reaction

NASA Astrophysics Data System (ADS)

Gyevi-Nagy, László; Lantos, Emese; Gehér-Herczegh, Tünde; Tóth, Ágota; Bagyinka, Csaba; Horváth, Dezső

2018-04-01

We have built a model to describe the hydrogenase catalyzed, autocatalytic, reversible hydrogen oxidation reaction where one of the enzyme forms is the autocatalyst. The model not only reproduces the experimentally observed front properties, but also explains the found hydrogen ion dependence. Furthermore, by linear stability analysis, two different front types are found in good agreement with the experiments.

47 CFR 1.981 - Reports, annual and semiannual.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 1 2011-10-01 2011-10-01 false Reports, annual and semiannual. 1.981 Section 1.981 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Wireless Radio... use of radio station facilities must submit annually an audited financial statement reflecting the...

Contribution of river floods, hurricanes, and cold fronts to elevation change in a deltaic floodplain, northern Gulf of Mexico, USA

NASA Astrophysics Data System (ADS)

Bevington, Azure E.; Twilley, Robert R.; Sasser, Charles E.; Holm, Guerry O.

2017-05-01

Deltas are globally important locations of diverse ecosystems, human settlement, and economic activity that are threatened by reductions in sediment delivery, accelerated sea level rise, and subsidence. Here we investigated the relative contribution of river flooding, hurricanes, and cold fronts on elevation change in the prograding Wax Lake Delta (WLD). Sediment surface elevation was measured across 87 plots, eight times from February 2008 to August 2011. The high peak discharge river floods in 2008 and 2011 resulted in the greatest mean net elevation gain of 5.4 to 4.9 cm over each flood season, respectively. The highest deltaic wetland sediment retention (13.5% of total sediment discharge) occurred during the 2008 river flood despite lower total and peak discharge compared to 2011. Hurricanes Gustav and Ike resulted in a total net elevation gain of 1.2 cm, but the long-term contribution of hurricane derived sediments to deltaic wetlands was estimated to be just 22% of the long-term contribution of large river floods. Winter cold front passage resulted in a net loss in elevation that is equal to the elevation gain from lower discharge river floods and was consistent across years. This amount of annual loss in elevation from cold fronts could effectively negate the long-term land building capacity within the delta without the added elevation gain from both high and low discharge river floods. The current lack of inclusion of cold front elevation loss in most predictive numerical models likely overestimates the land building capacity in areas that experience similar forcings to WLD.

Subduction at upper ocean fronts by baroclinic instability

NASA Astrophysics Data System (ADS)

Verma, Vicky; Pham, Hieu T.; Radhakrishnan, Anand; Sarkar, Sutanu

2017-11-01

Large eddy simulations of upper ocean fronts that are initially in geostrophic balance show that the linear and subsequent nonlinear evolution of baroclinic intability are effective in restratifying the front. During the growth of baroclinic instability, the front develops thin regions with enhanced vertical vorticity, i.e., vorticity filaments. Moreover, the vorticity filaments organize into submesoscale eddies. The subsequent frontal dynamics is dominated by the vorticity filaments and the submesoscale eddies. Diagnosis of the horizontal force balance reveals that the regions occupied by these coherent structures have significantly large imbalance, and are characterized by large vertical velocity. High density fluid from the heavier side of the front is subducted by the vertical velocity to the bottom of the mixed layer. The process of subduction is illustrated by Lagrangian tracking of fluid particles released at a fixed depth.

Research fronts analysis : A bibliometric to identify emerging fields of research

NASA Astrophysics Data System (ADS)

Miwa, Sayaka; Ando, Satoko

Research fronts analysis identifies emerging areas of research through observing co-clustering in highly-cited papers. This article introduces the concept of research fronts analysis, explains its methodology and provides case examples. It also demonstrates developing research fronts in Japan by looking at the past winners of Thomson Reuters Research Fronts Awards. Research front analysis is currently being used by the Japanese government to determine new trends in science and technology. Information professionals can also utilize this bibliometric as a research evaluation tool.

SDO AIA Observations of Large-Scale Coronal Disturbances in the Form of Propagating Fronts

NASA Astrophysics Data System (ADS)

Nitta, Nariaki V.; Schrijver, Carolus J.; Title, Alan M.; Liu, Wei

2013-03-01

One of the most spectacular phenomena detected by SOHO EIT was the large-scale propagating fronts associated with solar eruptions. Initially these 'EIT' waves were thought to be coronal counterparts of chromospheric Moreton waves. However, different spatial and kinematic properties of the fronts seen in H-alpha and EUV images, and far more frequent occurrences of the latter have led to various interpretations that are still actively debated by a number of researchers. A major factor for the lack of closure was the various limitation in EIT data, including the cadence that was typically every 12 minutes. Now we have significantly improved data from SDO AIA, which have revealed some very interesting phenomena associated with EIT waves. However, the studies so far conducted using AIA data have primarily dealt with single or a small number of events, where selection bias and particular observational conditions may prevent us from discovering the general and true nature of EIT waves. Although automated detection of EIT waves was promised for AIA images some time ago, it is still not actually implemented in the data pipeline. Therefore we have manually found nearly 200 examples of large-scale propagating fronts, going through movies of difference images from the AIA 193 A channel up to January 2013. We present our study of the kinematic properties of the fronts in a subset of about 150 well-observed events in relation with other phenomena that can accompany EIT waves. Our emphasis is on the relation of the fronts with the associated coronal eruptions often but not always taking the form of full-blown CMEs, utilizing STEREO data for a subset of more than 80 events that have occurred near the limb as viewed from one of the STEREO spacecraft. In these events, the availability of data from the STEREO inner coronagraph (COR1) as well as from the EUVI allows us to trace eruptions off the solar disk during the times of our propagating fronts. The representative relations

Submesoscale-selective compensation of fronts in a salinity-stratified ocean.

PubMed

Spiro Jaeger, Gualtiero; Mahadevan, Amala

2018-02-01

Salinity, rather than temperature, is the leading influence on density in some regions of the world's upper oceans. In the Bay of Bengal, heavy monsoonal rains and runoff generate strong salinity gradients that define density fronts and stratification in the upper ~50 m. Ship-based observations made in winter reveal that fronts exist over a wide range of length scales, but at O(1)-km scales, horizontal salinity gradients are compensated by temperature to alleviate about half the cross-front density gradient. Using a process study ocean model, we show that scale-selective compensation occurs because of surface cooling. Submesoscale instabilities cause density fronts to slump, enhancing stratification along-front. Specifically for salinity fronts, the surface mixed layer (SML) shoals on the less saline side, correlating sea surface salinity (SSS) with SML depth at O(1)-km scales. When losing heat to the atmosphere, the shallower and less saline SML experiences a larger drop in temperature compared to the adjacent deeper SML on the salty side of the front, thus correlating sea surface temperature (SST) with SSS at the submesoscale. This compensation of submesoscale fronts can diminish their strength and thwart the forward cascade of energy to smaller scales. During winter, salinity fronts that are dynamically submesoscale experience larger temperature drops, appearing in satellite-derived SST as cold filaments. In freshwater-influenced regions, cold filaments can mark surface-trapped layers insulated from deeper nutrient-rich waters, unlike in other regions, where they indicate upwelling of nutrient-rich water and enhanced surface biological productivity.

Submesoscale-selective compensation of fronts in a salinity-stratified ocean

PubMed Central

Spiro Jaeger, Gualtiero; Mahadevan, Amala

2018-01-01

Salinity, rather than temperature, is the leading influence on density in some regions of the world’s upper oceans. In the Bay of Bengal, heavy monsoonal rains and runoff generate strong salinity gradients that define density fronts and stratification in the upper ~50 m. Ship-based observations made in winter reveal that fronts exist over a wide range of length scales, but at O(1)-km scales, horizontal salinity gradients are compensated by temperature to alleviate about half the cross-front density gradient. Using a process study ocean model, we show that scale-selective compensation occurs because of surface cooling. Submesoscale instabilities cause density fronts to slump, enhancing stratification along-front. Specifically for salinity fronts, the surface mixed layer (SML) shoals on the less saline side, correlating sea surface salinity (SSS) with SML depth at O(1)-km scales. When losing heat to the atmosphere, the shallower and less saline SML experiences a larger drop in temperature compared to the adjacent deeper SML on the salty side of the front, thus correlating sea surface temperature (SST) with SSS at the submesoscale. This compensation of submesoscale fronts can diminish their strength and thwart the forward cascade of energy to smaller scales. During winter, salinity fronts that are dynamically submesoscale experience larger temperature drops, appearing in satellite-derived SST as cold filaments. In freshwater-influenced regions, cold filaments can mark surface-trapped layers insulated from deeper nutrient-rich waters, unlike in other regions, where they indicate upwelling of nutrient-rich water and enhanced surface biological productivity. PMID:29507874

11. VIEW NORTH, SOUTH FRONT OF MAIN OFFICE UNIT (BUILDING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. VIEW NORTH, SOUTH FRONT OF MAIN OFFICE UNIT (BUILDING I, 2); SOUTH AND EAST FRONTS OF SEED STORAGE BUILDING (BUILDING 21); EAST FRONT OF GREENHOUSE #1 (BUILDING 5) - U.S. Plant Introduction Station, 11601 Old Pond Road, Glenn Dale, Prince George's County, MD

Simulating the Evolving Behavior of Secondary Slow Slip Fronts

NASA Astrophysics Data System (ADS)

Peng, Y.; Rubin, A. M.

2017-12-01

High-resolution tremor catalogs of slow slip events reveal secondary slow slip fronts behind the main front that repetitively occupy the same source area during a single episode. These repetitive fronts are most often observed in regions with high tremor density. Their recurrence intervals gradually increase from being too short to be tidally modulated (tens of minutes) to being close to tidal periods (about 12 or 24 hours). This could be explained by a decreasing loading rate from creep in the surrounding regions (with few or no observable tremor events) as the main front passes by. As the recurrence intervals of the fronts increase, eventually they lock in on the tidal periods. We attempt to simulate this numerically using a rate-and-state friction law that transitions from velocity-weakening at low slip speeds to velocity strengthening at high slip speeds. Many small circular patches with a cutoff velocity an order of magnitude higher than that of the background are randomly placed on the fault, in order to simulate the average properties of the high-density tremor zone. Preliminary results show that given reasonable parameters, this model produces similar propagation speeds of the forward-migrating main front inside and outside the high-density tremor zone, consistent with observations. We will explore the behavior of the secondary fronts that arise in this model, in relation to the local density of the small tremor-analog patches, the overall geometry of the tremor zone and the tides.

Fluid front morphologies in gap-modulated Hele-Shaw cells

NASA Astrophysics Data System (ADS)

Díaz-Piola, Lautaro; Planet, Ramon; Campàs, Otger; Casademunt, Jaume; Ortín, Jordi

2017-09-01

We consider the displacement of an inviscid fluid (air) by a viscous fluid (oil) in a narrow channel with gap-thickness modulations. The interfacial dynamics of this problem is strongly nonlocal and exhibits competing effects from capillarity and permeability. We derive analytical predictions of steady-state front morphologies, which are exact at linear level in the case of a persistent modulation in the direction of front advancement. The theoretical predictions are in good agreement with experimental measurements of steady-state front morphologies obtained in a Hele-Shaw cell with modulations of the channel depth, consisting on three parallel tracks of reduced depth, for small gap modulations. The relative average distance between theoretical and experimental fronts in the region around the central track is smaller than about 4 % , provided that the height of the tracks is less than 13 % of the total channel depth and the local distortion of the front height h is small enough (|∇ h |<0.8 ) for the linear approximation to hold.

Idaho National Laboratory PCB Annual Document Log and Annual Records Report for calendar year 2014

DOE Office of Scientific and Technical Information (OSTI.GOV)

Layton, Deborah L.

The requirements for the reporting of polychlorinated biphenyl (PCB)-related activities are found in 40 Code of Federal Regulations (CFR) 761 Subpart J, "General Records and Reports." The PCB Annual Document Log is a detailed record of the PCB waste handling activities at the facility. The facility must prepare it each year by July 1 and maintain it at the facility for at least 3 years after the facility ceases using or storing PCBs and PCB items. While submittal of the PCB Annual Document Log to the U.S. Environmental Protection Agency (EPA) is not required by regulation, EPA has verbally requestedmore » in telephone conversations that this report be submitted to them on an annual basis. The Annual Records are not required to be submitted to EPA and are not considered to be part of the Annual Document Log, but are included to provide the complete disposition history or status of all PCB activities during the year. The Annual Document Log section of this report (Section 2.0) meets the requirements of 40 CFR 761.180(a)(2), as applicable, while the Annual Records section (Section 3.0) meets the requirement of 40 CFR 761.180(a)(1).« less

The Store Front School.

ERIC Educational Resources Information Center

Forrest, Barbara

1986-01-01

Describes the Store Front School project, a program of cooperative education aimed at rekindling students' interest in school and helping them earn their diplomas. The school conducts classes in an office in a shopping mall where the students work. (ABB)

Rapid acceleration of protons upstream of earthward propagating dipolarization fronts

PubMed Central

Ukhorskiy, AY; Sitnov, MI; Merkin, VG; Artemyev, AV

2013-01-01

[1] Transport and acceleration of ions in the magnetotail largely occurs in the form of discrete impulsive events associated with a steep increase of the tail magnetic field normal to the neutral plane (Bz), which are referred to as dipolarization fronts. The goal of this paper is to investigate how protons initially located upstream of earthward moving fronts are accelerated at their encounter. According to our analytical analysis and simplified two-dimensional test-particle simulations of equatorially mirroring particles, there are two regimes of proton acceleration: trapping and quasi-trapping, which are realized depending on whether the front is preceded by a negative depletion in Bz. We then use three-dimensional test-particle simulations to investigate how these acceleration processes operate in a realistic magnetotail geometry. For this purpose we construct an analytical model of the front which is superimposed onto the ambient field of the magnetotail. According to our numerical simulations, both trapping and quasi-trapping can produce rapid acceleration of protons by more than an order of magnitude. In the case of trapping, the acceleration levels depend on the amount of time particles stay in phase with the front which is controlled by the magnetic field curvature ahead of the front and the front width. Quasi-trapping does not cause particle scattering out of the equatorial plane. Energization levels in this case are limited by the number of encounters particles have with the front before they get magnetized behind it. PMID:26167430

45 CFR 1801.1 - Annual Truman Scholarship competition.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Annual Truman Scholarship competition. 1801.1... SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM General § 1801.1 Annual Truman Scholarship competition. Each year, the Harry S. Truman Scholarship Foundation carries out a nationwide competition to...

45 CFR 1801.1 - Annual Truman Scholarship competition.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Annual Truman Scholarship competition. 1801.1... SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM General § 1801.1 Annual Truman Scholarship competition. Each year, the Harry S. Truman Scholarship Foundation carries out a nationwide competition to...

45 CFR 1801.1 - Annual Truman Scholarship competition.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 4 2012-10-01 2012-10-01 false Annual Truman Scholarship competition. 1801.1... SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM General § 1801.1 Annual Truman Scholarship competition. Each year, the Harry S. Truman Scholarship Foundation carries out a nationwide competition to...

45 CFR 1801.1 - Annual Truman Scholarship competition.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 4 2013-10-01 2013-10-01 false Annual Truman Scholarship competition. 1801.1... SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM General § 1801.1 Annual Truman Scholarship competition. Each year, the Harry S. Truman Scholarship Foundation carries out a nationwide competition to...

45 CFR 1801.1 - Annual Truman Scholarship competition.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 4 2014-10-01 2014-10-01 false Annual Truman Scholarship competition. 1801.1... SCHOLARSHIP FOUNDATION HARRY S. TRUMAN SCHOLARSHIP PROGRAM General § 1801.1 Annual Truman Scholarship competition. Each year, the Harry S. Truman Scholarship Foundation carries out a nationwide competition to...

Prize to a Faculty Member for Research in an Undergraduate: Chaotic mixing and front propagation

NASA Astrophysics Data System (ADS)

Solomon, Tom

2014-03-01

We present results from a series of experiments - all done with undergraduate students - on chaotic fluid mixing and the effects of fluid flows on the behavior of reaction systems. Simple, well-ordered laminar fluid flows can give rise to fluid mixing with complexity far beyond that of the underlying flow, with tracers that separate exponentially in time and invariant manifolds that act as barriers to transport. Recently, we have studied how fluid mixing affects the propagation of reaction fronts in a flow. This is an issue with applications to a wide range of systems including microfluidic chemical reactors, blooms of phytoplankton in the oceans, and the spreading of a disease in a moving population. To analyze and predict the behavior of the fronts, we generalize tools developed to describe passive mixing. In particular, the concept of an invariant manifold is expanded to account for reactive burning. ``Burning invariant manifolds'' (BIMs) are predicted and measured experimentally as structures in the flow that act as one-way barriers that block the motion of reaction fronts. We test these ideas experimentally in three fluid flows: (a) and chain of alternating vortices; (b) an extended, spatially-random pattern of vortices; and (c) a time-independent, three-dimensional, nested vortex flow. The reaction fronts are produced chemically with variations of the well-known Belousov-Zhabotinsky reaction. Supported by Research Corporation and the National Science Foundation.

Dynamics of one- and two-dimensional fronts in a bistable equation with time-delayed global feedback: Propagation failure and control mechanisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boubendir, Yassine; Mendez, Vicenc; Rotstein, Horacio G.

2010-09-15

We study the evolution of fronts in a bistable equation with time-delayed global feedback in the fast reaction and slow diffusion regime. This equation generalizes the Hodgkin-Grafstein and Allen-Cahn equations. We derive a nonlinear equation governing the motion of fronts, which includes a term with delay. In the one-dimensional case this equation is linear. We study the motion of one- and two-dimensional fronts, finding a much richer dynamics than for the previously studied cases (without time-delayed global feedback). We explain the mechanism by which localized fronts created by inhibitory global coupling loose stability in a Hopf bifurcation as the delaymore » time increases. We show that for certain delay times, the prevailing phase is different from that corresponding to the system in the absence of global coupling. Numerical simulations of the partial differential equation are in agreement with the analytical predictions.« less

A downslope propagating thermal front over the continental slope

NASA Astrophysics Data System (ADS)

van Haren, Hans; Hosegood, Phil J.

2017-04-01

In the ocean, internal frontal bores above sloping topography have many appearances, depending on the local density stratification, and on the angle and source of generation of the carrier wave. However, their common characteristics are a backward breaking wave, strong sediment resuspension, and relatively cool (denser) water moving more or less upslope underneath warm (less dense) water. In this paper, we present a rare example of a downslope moving front of cold water moving over near-bottom warm water. Large backscatter is observed in the downslope moving front's trailing edge, rather than the leading edge as is common in upslope moving fronts. Time series observations have been made during a fortnight in summer, using a 101 m long array of high-resolution temperature sensors moored with an acoustic Doppler current profiler at 396 m depth in near-homogeneous waters, near a small canyon in the continental slope off the Malin shelf (West-Scotland, UK). Occurring between fronts that propagate upslope with tidal periodicity, the rare downslope propagating one resembles a gravity current and includes strong convective turbulence coming from the interior rather than the more usual frictionally generated turbulence arising from interaction with the seabed. Its turbulence is 3-10 times larger than that of more common upslope propagating fronts. As the main turbulence is in the interior with a thin stratified layer close to the bottom, little sediment is resuspended by a downslope propagating front. The downslope propagating front is suggested to be generated by oblique propagation of internal (tidal) waves and flow over a nearby upstream promontory.

Fibre laser cutting stainless steel: Fluid dynamics and cut front morphology

NASA Astrophysics Data System (ADS)

Pocorni, Jetro; Powell, John; Deichsel, Eckard; Frostevarg, Jan; Kaplan, Alexander F. H.

2017-01-01

In this paper the morphology of the laser cut front generated by fibre lasers was investigated by observation of the 'frozen' cut front, additionally high speed imaging (HSI) was employed to study the fluid dynamics on the cut front while cutting. During laser cutting the morphology and flow properties of the melt film on the cut front affect cut quality parameters such as cut edge roughness and dross (residual melt attached to the bottom of the cut edge). HSI observation of melt flow down a laser cutting front using standard cutting parameters is experimentally problematic because the cut front is narrow and surrounded by the kerf walls. To compensate for this, artificial parameters are usually chosen to obtain wide cut fronts which are unrepresentative of the actual industrial process. This paper presents a new experimental cutting geometry which permits HSI of the laser cut front using standard, commercial parameters. These results suggest that the cut front produced when cutting medium section (10 mm thick) stainless steel with a fibre laser and a nitrogen assist gas is covered in humps which themselves are covered by a thin layer of liquid. HSI observation and theoretical analysis reveal that under these conditions the humps move down the cut front at an average speed of approximately 0.4 m/s while the covering liquid flows at an average speed of approximately 1.1 m/s, with an average melt depth at the bottom of the cut zone of approximately 0.17 mm.

Light-front holographic QCD and emerging confinement

DOE PAGES

Brodsky, Stanley J.; de Téramond, Guy F.; Dosch, Hans Günter; ...

2015-05-21

In this study we explore the remarkable connections between light-front dynamics, its holographic mapping to gravity in a higher-dimensional anti-de Sitter (AdS) space, and conformal quantum mechanics. This approach provides new insights into the origin of a fundamental mass scale and the physics underlying confinement dynamics in QCD in the limit of massless quarks. The result is a relativistic light-front wave equation for arbitrary spin with an effective confinement potential derived from a conformal action and its embedding in AdS space. This equation allows for the computation of essential features of hadron spectra in terms of a single scale. Themore » light-front holographic methods described here give a precise interpretation of holographic variables and quantities in AdS space in terms of light-front variables and quantum numbers. This leads to a relation between the AdS wave functions and the boost-invariant light-front wave functions describing the internal structure of hadronic bound-states in physical spacetime. The pion is massless in the chiral limit and the excitation spectra of relativistic light-quark meson and baryon bound states lie on linear Regge trajectories with identical slopes in the radial and orbital quantum numbers. In the light-front holographic approach described here currents are expressed as an infinite sum of poles, and form factors as a product of poles. At large q 2 the form factor incorporates the correct power-law fall-off for hard scattering independent of the specific dynamics and is dictated by the twist. At low q 2 the form factor leads to vector dominance. The approach is also extended to include small quark masses. We briefly review in this report other holographic approaches to QCD, in particular top-down and bottom-up models based on chiral symmetry breaking. We also include a discussion of open problems and future applications.« less

Turbulent premixed combustion in V-shaped flames: Characteristics of flame front

NASA Astrophysics Data System (ADS)

Kheirkhah, S.; Gülder, Ö. L.

2013-05-01

Flame front characteristics of turbulent premixed V-shaped flames were investigated experimentally using the Mie scattering and the particle image velocimetry techniques. The experiments were performed at mean streamwise exit velocities of 4.0, 6.2, and 8.6 m/s, along with fuel-air equivalence ratios of 0.7, 0.8, and 0.9. Effects of vertical distance from the flame-holder, mean streamwise exit velocity, and fuel-air equivalence ratio on statistics of the distance between the flame front and the vertical axis, flame brush thickness, flame front curvature, and angle between tangent to the flame front and the horizontal axis were studied. The results show that increasing the vertical distance from the flame-holder and the fuel-air equivalence ratio increase the mean and root-mean-square (RMS) of the distance between the flame front and the vertical axis; however, increasing the mean streamwise exit velocity decreases these statistics. Spectral analysis of the fluctuations of the flame front position depicts that the normalized and averaged power-spectrum-densities collapse and show a power-law relation with the normalized wave number. The flame brush thickness is linearly correlated with RMS of the distance between the flame front and the vertical axis. Analysis of the curvature of the flame front data shows that the mean curvature is independent of the experimental conditions tested and equals to zero. Values of the inverse of the RMS of flame front curvature are similar to those of the integral length scale, suggesting that the large eddies in the flow make a significant contribution in wrinkling of the flame front. Spectral analyses of the flame front curvature as well as the angle between tangent to the flame front and the horizontal axis show that the power-spectrum-densities feature a peak. Value of the inverse of the wave number pertaining to the peak is larger than that of the integral length scale.

5-D interpolation with wave-front attributes

NASA Astrophysics Data System (ADS)

Xie, Yujiang; Gajewski, Dirk

2017-11-01

Most 5-D interpolation and regularization techniques reconstruct the missing data in the frequency domain by using mathematical transforms. An alternative type of interpolation methods uses wave-front attributes, that is, quantities with a specific physical meaning like the angle of emergence and wave-front curvatures. In these attributes structural information of subsurface features like dip and strike of a reflector are included. These wave-front attributes work on 5-D data space (e.g. common-midpoint coordinates in x and y, offset, azimuth and time), leading to a 5-D interpolation technique. Since the process is based on stacking next to the interpolation a pre-stack data enhancement is achieved, improving the signal-to-noise ratio (S/N) of interpolated and recorded traces. The wave-front attributes are determined in a data-driven fashion, for example, with the Common Reflection Surface (CRS method). As one of the wave-front-attribute-based interpolation techniques, the 3-D partial CRS method was proposed to enhance the quality of 3-D pre-stack data with low S/N. In the past work on 3-D partial stacks, two potential problems were still unsolved. For high-quality wave-front attributes, we suggest a global optimization strategy instead of the so far used pragmatic search approach. In previous works, the interpolation of 3-D data was performed along a specific azimuth which is acceptable for narrow azimuth acquisition but does not exploit the potential of wide-, rich- or full-azimuth acquisitions. The conventional 3-D partial CRS method is improved in this work and we call it as a wave-front-attribute-based 5-D interpolation (5-D WABI) as the two problems mentioned above are addressed. Data examples demonstrate the improved performance by the 5-D WABI method when compared with the conventional 3-D partial CRS approach. A comparison of the rank-reduction-based 5-D seismic interpolation technique with the proposed 5-D WABI method is given. The comparison reveals that

Null geodesics and wave front singularities in the Gödel space-time

NASA Astrophysics Data System (ADS)

Kling, Thomas P.; Roebuck, Kevin; Grotzke, Eric

2018-01-01

We explore wave fronts of null geodesics in the Gödel metric emitted from point sources both at, and away from, the origin. For constant time wave fronts emitted by sources away from the origin, we find cusp ridges as well as blue sky metamorphoses where spatially disconnected portions of the wave front appear, connect to the main wave front, and then later break free and vanish. These blue sky metamorphoses in the constant time wave fronts highlight the non-causal features of the Gödel metric. We introduce a concept of physical distance along the null geodesics, and show that for wave fronts of constant physical distance, the reorganization of the points making up the wave front leads to the removal of cusp ridges.

A Report to the People. 20 Years of Your National Commitment to Public Broadcasting, 1967-1987. 1986 Annual Report.

ERIC Educational Resources Information Center

Corporation for Public Broadcasting, Washington, DC.

This annual report for the Corporation for Public Broadcasting (CPB) for fiscal year 1986 also summarizes the CPB's activities over the last 20 years. The front inside cover folds out to three pages and provides a chronology of the important events in CPB history from its inception in 1967 to 1987. A narrative report on the CPB's 20 years of…

Stability of cosmological detonation fronts

NASA Astrophysics Data System (ADS)

Mégevand, Ariel; Membiela, Federico Agustín

2014-05-01

The steady-state propagation of a phase-transition front is classified, according to hydrodynamics, as a deflagration or a detonation, depending on its velocity with respect to the fluid. These propagation modes are further divided into three types, namely, weak, Jouguet, and strong solutions, according to their disturbance of the fluid. However, some of these hydrodynamic modes will not be realized in a phase transition. One particular cause is the presence of instabilities. In this work we study the linear stability of weak detonations, which are generally believed to be stable. After discussing in detail the weak detonation solution, we consider small perturbations of the interface and the fluid configuration. When the balance between the driving and friction forces is taken into account, it turns out that there are actually two different kinds of weak detonations, which behave very differently as functions of the parameters. We show that the branch of stronger weak detonations are unstable, except very close to the Jouguet point, where our approach breaks down.

Movements and habitat use of White-fronted Geese (Anser albifrons frontalis) during the remigial molt in arctic Alaska, USA

USGS Publications Warehouse

Flint, Paul L.; Meixell, Brandt W.

2017-01-01

Proposed oil and gas leasing in the National Petroleum Reserve - Alaska has raised questions about possible impacts of development on molting Greater White-fronted Geese (Anser albifrons frontalis) and their habitats. We used GPS transmitters to record fine-scale location data of molting and post-molt White-fronted Geese to assess patterns of movement and resource selection relative to vegetation class, year (2012, 2013), and body mass at capture. Molting White-fronted Geese were located an average of 63.3 ± 4.9 m (SE) from lakeshores. Estimated terrestrial home range size for flightless birds differed between years (2012 = 13.2 ± 2.6 km2; 2013 = 6.5 ± 1.8 km2), but did not vary among habitat strata or with body mass. Molting White-fronted Geese used sedge (Carex aquatilus) dominated low centered polygons and water more frequently than expected given proportional habitat availability, but avoided tussock tundra and wet sedge vegetation classes. Upon regaining flight, individuals tended to remain in the same general area, and the center of their home range only moved an average of 6.9 km. Greater White-fronted Geese that could fly tended to forage further from lakeshores ( = 245 m), and used a larger home range ( = 44.3 ± 9.5 km2) than when flightless.

Estimating generalized skew of the log-Pearson Type III distribution for annual peak floods in Illinois

USGS Publications Warehouse

Oberg, Kevin A.; Mades, Dean M.

1987-01-01

Four techniques for estimating generalized skew in Illinois were evaluated: (1) a generalized skew map of the US; (2) an isoline map; (3) a prediction equation; and (4) a regional-mean skew. Peak-flow records at 730 gaging stations having 10 or more annual peaks were selected for computing station skews. Station skew values ranged from -3.55 to 2.95, with a mean of -0.11. Frequency curves computed for 30 gaging stations in Illinois using the variations of the regional-mean skew technique are similar to frequency curves computed using a skew map developed by the US Water Resources Council (WRC). Estimates of the 50-, 100-, and 500-yr floods computed for 29 of these gaging stations using the regional-mean skew techniques are within the 50% confidence limits of frequency curves computed using the WRC skew map. Although the three variations of the regional-mean skew technique were slightly more accurate than the WRC map, there is no appreciable difference between flood estimates computed using the variations of the regional-mean technique and flood estimates computed using the WRC skew map. (Peters-PTT)

A study on the consumer's perception of front-of-pack nutrition labeling

PubMed Central

Kim, Woo Kyoung

2009-01-01

The goal of this research is to investigate the present situation for front of pack labeling in Korea and the perception of consumers for the new system of labeling, front of pack labeling, based on the consumer survey. We investigated the number of processed foods with front of pack labeling in one retailer in Youngin-si. And we also surveyed 1,019 participants nationwide whose ages were from 20 to 49; the knowledge of nutrition labeling, the knowledge of 'front of pack labeling', and the opinion about the labeling system. The data were analyzed using SAS statistics program. The results were as follows: 13.4% of processed foods had front of pack labeling, and 16.8% of the consumers always checked the nutrition labeling, while 32.7% of the consumers seldom checked it. In addition, 44.3% of the consumers think that 'front of pack labeling' is necessary, and 58.3% of the consumers think it is important to show the percentage of daily value as a way of 'front of pack labeling'. However, 32% of the consumer think the possibility of 'front of pack labeling' is slim. Meanwhile, 58.3% of the consumers think that it is important to have the color difference according to contents. The number of favorite nutrients in the front of pack was four or five. It seems that the recognition of current nutrition labeling has the influence on the willingness of using the future 'front of pack labeling'. Along with our study, the policy for 'front of pack labeling' has to be updated and improved constantly since 'front of pack labeling' helps consumer understand nutrition facts. PMID:20098583

Multiscale modeling of interfacial flow in particle-solidification front dynamics

NASA Astrophysics Data System (ADS)

Garvin, Justin

2005-11-01

Particle-solidification front interactions are important in many applications, such as metal-matrix composite manufacture, frost heaving in soils and cryopreservation. The typical length scale of the particles and the solidification fronts are of the order of microns. However, the force of interaction between the particle and the front typically arises when the gap between them is of the order of tens of nanometers. Thus, a multiscale approach is necessary to analyze particle-front interactions. Solving the Navier-Stokes equations to simulate the dynamics by including the nano-scale gap between the particle and the front would be impossible. Therefore, the microscale dynamics is solved using a level-set based Eulerian technique, while an embedded model is developed for solution in the nano-scale (but continuum) gap region. The embedded model takes the form of a lubrication equation with disjoining pressure acting as a body force and is coupled to the outer solution. A particle is pushed by the front when the disjoining pressure is balanced by the viscous drag. The results obtained show that this balance can only occur when the thermal conductivity ratio of the particle to the melt is less than 1.0. The velocity of the front at which the particle pushing/engulfment transition occurs is predicted. In addition, this novel method allows for an in-depth analysis of the flow physics that cause particle pushing/engulfment.

A general Bayesian framework for calibrating and evaluating stochastic models of annual multi-site hydrological data

NASA Astrophysics Data System (ADS)

Frost, Andrew J.; Thyer, Mark A.; Srikanthan, R.; Kuczera, George

2007-07-01

SummaryMulti-site simulation of hydrological data are required for drought risk assessment of large multi-reservoir water supply systems. In this paper, a general Bayesian framework is presented for the calibration and evaluation of multi-site hydrological data at annual timescales. Models included within this framework are the hidden Markov model (HMM) and the widely used lag-1 autoregressive (AR(1)) model. These models are extended by the inclusion of a Box-Cox transformation and a spatial correlation function in a multi-site setting. Parameter uncertainty is evaluated using Markov chain Monte Carlo techniques. Models are evaluated by their ability to reproduce a range of important extreme statistics and compared using Bayesian model selection techniques which evaluate model probabilities. The case study, using multi-site annual rainfall data situated within catchments which contribute to Sydney's main water supply, provided the following results: Firstly, in terms of model probabilities and diagnostics, the inclusion of the Box-Cox transformation was preferred. Secondly the AR(1) and HMM performed similarly, while some other proposed AR(1)/HMM models with regionally pooled parameters had greater posterior probability than these two models. The practical significance of parameter and model uncertainty was illustrated using a case study involving drought security analysis for urban water supply. It was shown that ignoring parameter uncertainty resulted in a significant overestimate of reservoir yield and an underestimation of system vulnerability to severe drought.

Heterogeneous porous media: Fronts and noise

NASA Astrophysics Data System (ADS)

Chaouchel, M.; Rakotomalala, N.; Salin, D.; Xu, B.; Yortsos, Y. C.

Capillary effects can be important in immiscible flows in heterogeneous media, particularly at low capillary numbers (Ca). We present experiments and simulations of slow drainage in 3-D porous media, either homogeneous and in the presence of buoyancy or heterogeneous and in its absence. An acoustic technique allows for an accurate study of the 3-D fronts and the cross-over region. Our results suggest that both cases can be described by invasion percolation in a gradient. Both front tails scale with the corresponding Bond numbers as σft≈B-47 in agreement with the theory. An analogous scaling for viscous effects is also given. The noise of these fronts are found correlated in the form of a fractional Brownian motion (fBm) of a Hurst exponent H≈.5. At higher Ca, experiments performed in 3-D porous media with sharp changes in permeability, exhibit a saturation profile response closely linked to the permeability variations. This viscous response to heterogeneity provides an opportunity to investigate and determine correlated (even at all scales, i.e. fBm), permeability fields.

The Parkes front-end controller and noise-adding radiometer

NASA Technical Reports Server (NTRS)

Brunzie, T. J.

1990-01-01

A new front-end controller (FEC) was installed on the 64-m antenna in Parkes, Australia, to support the 1989 Voyager 2 Neptune encounter. The FEC was added to automate operation of the front-end microwave hardware as part of the Deep Space Network's Parkes-Canberra Telemetry Array. Much of the front-end hardware was refurbished and reimplemented from a front-end system installed in 1985 by the European Space Agency for the Uranus encounter; however, the FEC and its associated noise-adding radiometer (NAR) were new Jet Propulsion Laboratory (JPL) designs. Project requirements and other factors led to the development of capabilities not found in standard Deep Space Network (DSN) controllers and radiometers. The Parkes FEC/NAR performed satisfactorily throughout the Neptune encounter and was removed in October 1989.

Concepts for a Muon Accelerator Front-End

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stratakis, Diktys; Berg, Scott; Neuffer, David

2017-03-16

We present a muon capture front-end scheme for muon based applications. In this Front-End design, a proton bunch strikes a target and creates secondary pions that drift into a capture channel, decaying into muons. A series of rf cavities forms the resulting muon beams into a series of bunches of differerent energies, aligns the bunches to equal central energies, and initiates ionization cooling. We also discuss the design of a chicane system for the removal of unwanted secondary particles from the muon capture region and thus reduce activation of the machine. With the aid of numerical simulations we evaluate themore » performance of this Front-End scheme as well as study its sensitivity against key parameters such as the type of target, the number of rf cavities and the gas pressure of the channel.« less

The formation of granular fronts in debris flow - A combined experimental-numerical study

NASA Astrophysics Data System (ADS)

Leonardi, Alessandro; Cabrera, Miguel; Wittel, Falk K.; Kaitna, Roland; Mendoza, Miller; Wu, Wei; Herrmann, Hans J.

2015-04-01

Granular fronts are amongst the most spectacular features of debris flows, and are also one of the reasons why such events are associated with a strong destructive power. They are usually believed to be the result of the convective mechanism of the debris flow, combined with internal size segregation of the grains. However, the knowledge about the conditions leading to the formation of a granular front is not up to date. We present a combined study with experimental and numerical features that aims at providing insight into the phenomenon. A stationary, long-lived avalanche is created within a rotating drum. In order to mimic the composition of an actual debris flow, the material is composed by a mixture of a plastic fluid, obtained with water and kaolin powder, and a collection of monodisperse spherical particles heavier than the fluid. Tuning the material properties and the drum settings, we are able to reproduce and control the formation of a granular front. To gain insight into the internal mechanism, the same scenario is replicated in a numerical environment, using a coupling technique between a discrete solver for the particles, the Discrete Element Method, and a continuum solver for the plastic fluid, the Lattice-Boltzmann Method. The simulations compare well with the experiments, and show the internal reorganization of the material transport. The formation of a granular front is shown to be favored by a higher drum rotational speed, which in turn forces a higher shear rate on the particles, breaks their internal organization, and contrasts their natural tendency to settle. Starting from dimensional analysis, we generalize the obtained results and are able to draw implications for debris flow research.

Annual Rural Manpower Report, 1975. State of Maine.

ERIC Educational Resources Information Center

Maine State Dept. of Manpower Affairs, Augusta.

The Annual Rural Manpower Report is a summary of events and programs affecting rural communities during 1975. Intended as a general overview of activities in rural Maine, it is not an indepth study of all manpower programs serving the state. Part I provides the annual summary and discusses planning, economic development, employment and…

Desirable forest structures for a restored Front Range

Treesearch

Yvette L. Dickinson; Rob Addington; Greg Aplet; Mike Babler; Mike Battaglia; Peter Brown; Tony Cheng; Casey Cooley; Dick Edwards; Jonas Feinstein; Paula Fornwalt; Hal Gibbs; Megan Matonis; Kristen Pelz; Claudia Regan

2014-01-01

As part of the federal Collaborative Forest Landscape Restoration Program administered by the US Forest Service, the Colorado Front Range Collaborative Forest Landscape Restoration Project (FR-CFLRP, a collaborative effort of the Front Range Roundtable1 and the US Forest Service) is required to define desired conditions for lower montane ponderosa pine (Pinus ponderosa...

Correlates of front-seat passengers' non-use of seatbelts at night.

PubMed

Boakye, Kwaku F; Khattak, Asad; Everett, Jerry; Nambisan, Shashi

2018-04-18

When properly worn, seatbelts can save lives. They are designed to prevent occupants from hitting objects inside their vehicle and from being ejected out of their vehicle in the event of a crash. Despite their proven effectiveness in reducing the severity of injuries, seatbelt non-use among passengers still remains a problem, especially at night. Although the factors associated with not using a seatbelt have been widely studied, research studies documenting this behavior at night are limited in the literature. The primary objective of this paper is to explore the factors related to front-seat passengers' seatbelt non-use at night using a 2015-2016 longitudinal observation survey conducted in five counties in East Tennessee. The Generalized Estimating Equation, a rigorous modeling technique, is employed for the data analysis. The findings show that front-seat passengers who are most likely to not wear seatbelts at night are males, traveling in passenger cars and pickup trucks, traveling during the first half of the year (January to June), traveling late at night (after 10 p.m) and on local streets. The findings also indicate that drivers may have the greatest influence on their accompanying passengers' seatbelt use. That is, when drivers fail to wear seatbelts at night, their accompanying front-seat passengers are more likely to fail as well. The model results show that there are many consistent correlations between the non-use of seatbelts and personal, vehicle and environmental characteristics. Accounting for these factors may be important when developing intervention strategies that promote nighttime seatbelt use. Published by Elsevier Ltd.

A Satellite View of a Back-door Cold Front

NASA Image and Video Library

2014-05-29

A "backdoor cold front" is bringing April temperatures to the U.S. northeast and Mid-Atlantic today, May 29. The backdoor cold front brings relief to the Mid-Atlantic after temperatures in Washington, D.C. hit 92F on Tuesday, May 27 and 88F on Wednesday, May 28 at Reagan National Airport, according to the National Weather Service (NWS). NWS forecasters expect the high temperature for May 29 to only reach 60F in the District of Columbia. NOAA's GOES-East satellite captured a view of the clouds associated with the backdoor cold front that stretch from southern Illinois to North Carolina. The National Weather Service forecast expects the backdoor cold front to bring showers to the Midwest, Northeast, and Mid-Atlantic today, May 29. According to the National Oceanic and Atmospheric Administration, a backdoor cold front is a cold front moving south or southwest along the Atlantic seaboard and Great Lakes; these are especially common during the spring months. This visible image was taken by NOAA's GOES-East satellite on May 29 at 12:30 UTC (8:30 a.m. EDT). The image was created at NASA/NOAA's GOES Project at NASA's Goddard Space Flight Center in Greenbelt, Maryland. In addition to the backdoor cold front clouds, the GOES-East image shows clouds circling around a low pressure area located in eastern Texas. That low pressure area is expected to bring rain from Texas eastward over the southeastern U.S. According to NOAA's National Weather Service, the slow-moving low pressure area in the Deep South "will bring heavy showers and thunderstorms from Louisiana to Alabama through Thursday. This area is already saturated from previous rainfall, so flash flooding will be possible." Image: NASA/NOAA GOES Project Caption: NASA Goddard/Rob Gutro

Case study of mesospheric front dissipation observed over the northeast of Brazil

NASA Astrophysics Data System (ADS)

Fragoso Medeiros, Amauri; Paulino, Igo; Wrasse, Cristiano Max; Fechine, Joaquim; Takahashi, Hisao; Valentin Bageston, José; Paulino, Ana Roberta; Arlen Buriti, Ricardo

2018-03-01

On 3 October 2005 a mesospheric front was observed over São João do Cariri (7.4° S, 36.5° W). This front propagated to the northeast and appeared in the airglow images on the west side of the observatory. By about 1.5 h later, it dissipated completely when the front crossed the local zenith. Ahead of the front, several ripple structures appeared during the dissipative process of the front. Using coincident temperature profile from the TIMED/SABER satellite and wind profiles from a meteor radar at São João do Cariri, the background of the atmosphere was investigated in detail. On the one hand, it was noted that a strong vertical wind shear in the propagation direction of the front produced by a semidiunal thermal tide was mainly responsible for the formation of duct (Doppler duct), in which the front propagated up to the zenith of the images. On the other hand, the evolution of the Richardson number as well as the appearance of ripples ahead of the main front suggested that a presence of instability in the airglow layer that did not allow the propagation of the front to the other side of the local zenith.

Front contact solar cell with formed electrically conducting layers on the front side and backside

DOEpatents

Cousins, Peter John

2012-06-26

A bipolar solar cell includes a backside junction formed by a silicon substrate and a first doped layer of a first dopant type on the backside of the solar cell. A second doped layer of a second dopant type makes an electrical connection to the substrate from the front side of the solar cell. A first metal contact of a first electrical polarity electrically connects to the first doped layer on the backside of the solar cell, and a second metal contact of a second electrical polarity electrically connects to the second doped layer on the front side of the solar cell. An external electrical circuit may be electrically connected to the first and second metal contacts to be powered by the solar cell.

Mapping and quantifying sediment transfer between the front of rapidly moving rock glaciers and torrential gullies

NASA Astrophysics Data System (ADS)

Kummert, Mario; Delaloye, Reynald

2018-05-01

The sedimentary connection which may occur between the front of active rock glaciers and torrential channels is not well understood, despite its potential impact on the torrential activity characterizing the concerned catchments. In this study, DEMs of difference (DoDs) covering various time intervals between 2013 and 2016 were obtained from LiDAR-derived multitemporal DEMs for three rapidly moving rock glaciers located in the western Swiss Alps. The DoDs were used to map and quantify sediment transfer activity between the front of these rock glaciers and the corresponding underlying torrential gullies. Sediment transfer rates ranging between 1500 m3/y and 7800 m3/y have been calculated, depending on the sites. Sediment eroded from the fronts generally accumulated in the upper sectors of the torrential gullies where they were occasionally mobilized within small to medium sized debris flow events. A clear relation between the motion rates of the rock glaciers and the sediment transfer rates calculated at their fronts could be highlighted. Along with the size of the frontal areas, rock glacier creep rates influence thus directly sediment availability in the headwaters of the studied torrents. The frequency-magnitude of debris flow events varied between sites and was mainly related to the concordance of local factors such as topography, water availability, sediment availability or sediment type.

Further Evaluation of an Emperical Equation for Annual Total Evaporation

NASA Technical Reports Server (NTRS)

Choudhury, Bhaskar J.

1999-01-01

An empirical equation for annual total evaporation based on annual precipitation and net radiation was found to provide evaporation within 10% of the observed values at seven locations within temperate and tropical regions, but it overestimated evaporation by 90% at one location within the tundra region. A synthesis of observations at two other locations within the tundra region gives overestimates of about 65%. A general analysis of observed precipitation, net radiation, and runoff within the tundra region shows that the empirical equation is generally biased to overestimate annual evaporation within the tundra region. A theoretical analysis is being done to understand the reason behind this bias.

40 CFR 81.52 - Wasatch Front Intrastate Air Quality Control Region.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Wasatch Front Intrastate Air Quality...) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.52 Wasatch Front Intrastate Air Quality Control Region. The Wasatch Front...

40 CFR 81.52 - Wasatch Front Intrastate Air Quality Control Region.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Wasatch Front Intrastate Air Quality...) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.52 Wasatch Front Intrastate Air Quality Control Region. The Wasatch Front...

40 CFR 81.52 - Wasatch Front Intrastate Air Quality Control Region.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 18 2014-07-01 2014-07-01 false Wasatch Front Intrastate Air Quality...) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.52 Wasatch Front Intrastate Air Quality Control Region. The Wasatch Front...

40 CFR 81.52 - Wasatch Front Intrastate Air Quality Control Region.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Wasatch Front Intrastate Air Quality...) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.52 Wasatch Front Intrastate Air Quality Control Region. The Wasatch Front...

40 CFR 81.52 - Wasatch Front Intrastate Air Quality Control Region.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Wasatch Front Intrastate Air Quality...) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.52 Wasatch Front Intrastate Air Quality Control Region. The Wasatch Front...

Annual Review of Aircraft Accident Data. US Carrier Operations Calendar Year 1997

DTIC Science & Technology

2002-01-24

its surveys of general aviation activity. National Transportation Safety Board Report Form 6120.4 (appendix F) shows the data elements upon which this...Beginning with the 1998 Annual Reviews, the Safety Board will present annual statistics for commercial and general aviation in a revised format. The...Operation N135 = Nonscheduled 14 CFR 135 Operation S121 = Scheduled 14 CFR 121 Operation Forgn = Foreign Registered Aircraft Operation GA = General

Speed of pulled fronts with a cutoff

NASA Astrophysics Data System (ADS)

Benguria, R. D.; Depassier, M. C.

2007-05-01

We study the effect of a small cutoff γ on the velocity of a pulled front in one dimension by means of a variational principle. We obtain a lower bound on the speed dependent on the cutoff, for which the two leading order terms correspond to the Brunet-Derrida expression. To do so we cast a known variational principle for the speed of propagation of fronts in different variables which makes it more suitable for applications.

Stability of a Shock-Decelerated Ablation Front

DTIC Science & Technology

2009-01-01

the target through the ablation front. Our experiments on the Nike laser at the Naval Research Laboratory (NRL) are aimed at obtaining...separated from the CH foil by a 100-120 μm wide vacuum gap. The front side of the plastic foil is irradiated by 37 overlapping beams of the Nike ...krypton fluoride laser ( 248=Lλ nm) [19]. The Nike laser produces a very uniform irradiation with a time-averaged rms non-uniformity ɘ.3% in a central

Wave-front propagation in a discrete model of excitable media

NASA Astrophysics Data System (ADS)

Feldman, A. B.; Chernyak, Y. B.; Cohen, R. J.

1998-06-01

We generalize our recent discrete cellular automata (CA) model of excitable media [Y. B. Chernyak, A. B. Feldman, and R. J. Cohen, Phys. Rev. E 55, 3215 (1997)] to incorporate the effects of inhibitory processes on the propagation of the excitation wave front. In the common two variable reaction-diffusion (RD) models of excitable media, the inhibitory process is described by the v ``controller'' variable responsible for the restoration of the equilibrium state following excitation. In myocardial tissue, the inhibitory effects are mainly due to the inactivation of the fast sodium current. We represent inhibition using a physical model in which the ``source'' contribution of excited elements to the excitation of their neighbors decreases with time as a simple function with a single adjustable parameter (a rate constant). We sought specific solutions of the CA state transition equations and obtained (both analytically and numerically) the dependence of the wave-front speed c on the four model parameters and the wave-front curvature κ. By requiring that the major characteristics of c(κ) in our CA model coincide with those obtained from solutions of a specific RD model, we find a unique set of CA parameter values for a given excitable medium. The basic structure of our CA solutions is remarkably similar to that found in typical RD systems (similar behavior is observed when the analogous model parameters are varied). Most notably, the ``turn-on'' of the inhibitory process is accompanied by the appearance of a solution branch of slow speed, unstable waves. Additionally, when κ is small, we obtain a family of ``eikonal'' relations c(κ) that are suitable for the kinematic analysis of traveling waves in the CA medium. We compared the solutions of the CA equations to CA simulations for the case of plane waves and circular (target) waves and found excellent agreement. We then studied a spiral wave using the CA model adjusted to a specific RD system and found good

2. EXTERIOR FRONT (SOUTHEAST) SIDE OF BUILDING 117 SHOWING MAIN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. EXTERIOR FRONT (SOUTHEAST) SIDE OF BUILDING 117 SHOWING MAIN RESIDENTIAL STREET IN LOWER FOREGROUND, CEMENT-LAID ROCK RETAINING WALL IN FRONT OF HOUSE, AND CONCRETE STEPS AND WALKWAY TO FRONT PORCH AND DOOR. NOTE SLIDING GLASS DOOR REPLACEMENT FOR ORIGINAL DOOR WHICH HAS SUBSEQUENTLY BEEN REMODELED BACK TO A SINGLE ENTRY DOOR. VIEW TO NORTHWEST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

25 CFR 141.24 - Attendance at semi-annual meetings.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FINANCIAL ACTIVITIES BUSINESS PRACTICES ON THE NAVAJO, HOPI AND ZUNI RESERVATIONS General Business Practices § 141.24 Attendance at semi-annual... attend a semi-annual public meeting of a tribal governing body to respond to customer inquiries. ...

Airpower Leadership on the Front Line: Lt Gen George H. Brett and Combat Command

DTIC Science & Technology

2006-09-01

front.indd 5 11/7/06 10:29:42 AM insight into the makings of effective leadership and successful command. THOMAS HUGHES Associate Professor School...transformed impossibilities into tasks completed. My thesis reader, Dr. Thomas Hughes, lent his unerring sense of style and his gifted historical...project. The commandant, Col Thomas E. Griffith, provided papers pertaining to General Brett from his collection of historical documents. Dr. Harold R

Have pedestrian subsystem tests improved passenger car front shape?

PubMed

Li, Guibing; Wang, Fang; Otte, Dietmar; Cai, Zhihua; Simms, Ciaran

2018-06-01

Subsystem impactor tests are the main approaches for evaluation of safety performance of vehicle front design for pedestrian protection in legislative regulations. However, the main aspects of vehicle safety for pedestrians are shape and stiffness, and though it is clear that subsystem impact tests encourage lower vehicle front stiffness, it is unclear whether they promote improved vehicle front shapes for pedestrian protection. The purpose of this paper is therefore to investigate the effects of European pedestrian safety regulations on passenger car front shape and pedestrian injury risk using recent German In-Depth Accident Study (GIDAS) pedestrian collision data and numerical simulations. Firstly, a sample of 579 pedestrian collision cases involving 190 different car models between 2000-2015 extracted from the GIDAS was used to compare front-end shapes of passenger cars manufactured before and after the legislative pedestrian safety regulations were introduced in Europe. The focus was on changes in passenger car front shape and differences in pedestrian AIS2+ (Abbreviated Injury Scale at least level 2) leg, pelvis/femur and head injury risk observed in collisions. Multi-body simulations were also used to assess changes in vehicle aggressivity due to the observed changes in vehicle shape. The results show that newer passenger cars tend to have a flatter and wider bumper, higher bonnet leading edge, shorter and steeper bonnet and a shallower windscreen. Both the collision data and the numerical simulations indicate that newer passenger car front bumper designs are significantly safer for pedestrians' legs. However, the results also show that the higher bonnet leading edge in newer passenger cars is poor for pedestrian pelvis/femur protection, even though newer cars show an obviously lower AIS2+ injury risk to younger pedestrians in collisions. Newer cars have a lower AIS2+ head injury risk for pedestrians in collisions, but the numerical analysis indicate that

Multiple stable isotope fronts during non-isothermal fluid flow

NASA Astrophysics Data System (ADS)

Fekete, Szandra; Weis, Philipp; Scott, Samuel; Driesner, Thomas

2018-02-01

Stable isotope signatures of oxygen, hydrogen and other elements in minerals from hydrothermal veins and metasomatized host rocks are widely used to investigate fluid sources and paths. Previous theoretical studies mostly focused on analyzing stable isotope fronts developing during single-phase, isothermal fluid flow. In this study, numerical simulations were performed to assess how temperature changes, transport phenomena, kinetic vs. equilibrium isotope exchange, and isotopic source signals determine mineral oxygen isotopic compositions during fluid-rock interaction. The simulations focus on one-dimensional scenarios, with non-isothermal single- and two-phase fluid flow, and include the effects of quartz precipitation and dissolution. If isotope exchange between fluid and mineral is fast, a previously unrecognized, significant enrichment in heavy oxygen isotopes of fluids and minerals occurs at the thermal front. The maximum enrichment depends on the initial isotopic composition of fluid and mineral, the fluid-rock ratio and the maximum change in temperature, but is independent of the isotopic composition of the incoming fluid. This thermally induced isotope front propagates faster than the signal related to the initial isotopic composition of the incoming fluid, which forms a trailing front behind the zone of transient heavy oxygen isotope enrichment. Temperature-dependent kinetic rates of isotope exchange between fluid and rock strongly influence the degree of enrichment at the thermal front. In systems where initial isotope values of fluids and rocks are far from equilibrium and isotope fractionation is controlled by kinetics, the temperature increase accelerates the approach of the fluid to equilibrium conditions with the host rock. Consequently, the increase at the thermal front can be less dominant and can even generate fluid values below the initial isotopic composition of the input fluid. As kinetics limit the degree of isotope exchange, a third front may

Charged Particle Distribution near the Shock Front in a Glow Discharge

NASA Astrophysics Data System (ADS)

Baryshnikov, A. S.; Basargin, I. V.; Bezverkhnii, N. O.; Bobashev, S. V.; Monakhov, N. A.; Popov, P. A.; Sakharov, V. A.; Chistyakova, M. V.

2018-02-01

The charged particle distribution near the front of a shock wave propagating in the glow discharge plasma has been investigated. It has been found that the ion concentration before the front varies nonmonotonically. Behind the shock front, the charged particle concentration varies smoothly in contrast to the neutral component density.

Regimental Medical Officer Charles McKerrow: saving lives on the Western Front.

PubMed

Mayhew, E

2014-01-01

Ayrshire general practitioner Charles McKerrow was appointed regimental medical officer (RMO) to the 10th Battalion Northumberland Fusiliers in 1915. At this time, fundamental restructuring of the military medical service on the Western Front had two main effects: surgical capability was moved forward as close to the front as possible and specialist stretcher bearers were trained to apply emergency first aid at the place of injury and to triage casualties appropriately. The specialist stretcher bearers were the equivalent of today's combat medical technicians. The reorganisation was undertaken in a rapid, improvised 'bottom-up' manner and there are very few official records to detail the process. McKerrow and RMOs of his calibre were integral to the successful implementation and operation of this reorganisation so their personal archives are the primary sources for its history. McKerrow's record is particularly detailed and insightful on the process; he was not only an extraordinarily fine medical officer but also provided expert testimony on a period of military medical change that was enduringly successful.

Kinetics of a plasma streamer ionization front

NASA Astrophysics Data System (ADS)

Taccogna, Francesco; Pellegrini, Fabrizio

2018-02-01

A streamer is a non-linear and non-local gas breakdown mode. Its large-scale coherent structures, such as the ionization front, are the final results of a hierarchical cascade starting from the single particle dynamics. Therefore, this phenomenon covers, by definition, different space and time scales. In this study, we have reproduced the ionization front formation and development by means of a particle-based numerical methodology. The physical system investigated concerns of a high-voltage ns-pulsed surface dielectric barrier discharge. Different reduced electric field regimes ranging from 50 to 500 Td have been considered for two gases: pure atomic Ar and molecular N2. Results have shown the detailed structure of the negative streamer: the leading edge, the head, the interior and the tail. Its dynamical evolution and the front propagation velocity have been calculated for the different cases. Finally, the deviation of the electron energy distribution function from equilibrium behavior has been pointed out as a result of a fast and very localized phenomenon.

Age Appropriate Restraints for the Right Front Passenger

PubMed Central

Augenstein, J; Perdeck, E.; Digges, K.; Bahouth, G.

2007-01-01

This study applies NASS/CDS, GES and FARS data to examine occupant exposure plus injury and fatality rates for belted occupants in frontal crashes by seating position, age and gender. The NASS data was used to examine the distributions by crash severity. The GES data showed that when two elderly occupants (age 65+) were present, the female occupied the right front passenger position 73% of the time. A paired comparison analysis using FARS data showed that, for elderly occupants (age 65+), the fatality risk for elderly right front passengers is 42% higher than for elderly drivers. The NASS/CDS analysis found 74% of the seriously injured vulnerable passengers with MAIS 3+ injuries were in crashes less severe than 26 mph. This group of injured occupants was made up of 43% aged 50 and older and 42% younger females. The injury rates for the older (age 50+) right front passengers were 1.8 times the rates for the elderly drivers. These results suggest the need for more benign safety systems for the right front passenger that are appropriate for the lower injury tolerance of the predominant occupants of that seating position. PMID:18184503

The split in the ancient cold front in the Perseus cluster

NASA Astrophysics Data System (ADS)

Walker, Stephen A.; ZuHone, John; Fabian, Andy; Sanders, Jeremy

2018-04-01

Sloshing cold fronts in clusters, produced as the dense cluster core moves around in the cluster potential in response to in-falling subgroups, provide a powerful probe of the physics of the intracluster medium and the magnetic fields permeating it1,2. These sharp discontinuities in density and temperature rise gradually outwards with age in a characteristic spiral pattern, embedding into the intracluster medium a record of the minor merging activity of clusters: the further from the cluster centre a cold front is, the older it is. Recently, it was discovered that these cold fronts can survive out to extremely large radii in the Perseus cluster3. Here, we report on high-spatial-resolution Chandra observations of the large-scale cold front in Perseus. We find that rather than broadening through diffusion, the cold front remains extremely sharp (consistent with abrupt jumps in density) and instead is split into two sharp edges. These results show that magnetic draping can suppress diffusion for vast periods of time—around 5 Gyr—even as the cold front expands out to nearly half the cluster virial radius.

5. AERIAL VIEW, FROM NORTH, SHOWING ROOF OF CARPENTER'S FRONT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. AERIAL VIEW, FROM NORTH, SHOWING ROOF OF CARPENTER'S FRONT STORE AND CARPENTER'S HALL IN CENTER BACKGROUND - Carpenters' Company, Front Store, 322 Chestnut Street & Carpenters' Court, Philadelphia, Philadelphia County, PA

Matrix cracking with irregular fracture fronts as observed in fiber reinforced ceramic composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, K.X.; Yeh, C.P.; Wyatt, K.W.

1998-01-01

As a result of matrix cracking in fiber reinforced composites, fracture planforms assume a wide variation of profiles due to the fact that fiber bridging strongly affects the behavior of local crack fronts. This observation raises the question on the legitimacy of commonly used penny-shaped crack solutions when applied to fiber reinforced composites. Accordingly, investigation of the effects of fracture front profiles on mechanical responses is the thrust of this paper. The authors start with the solution of a penny-shaped crack in a unidirectional, fiber reinforced composite, which demonstrates necessity of considering wavy fracture fronts in fiber reinforced composites. Amore » theoretical framework for fiber reinforced composites with irregular fracture fronts due to matrix cracking is then established via a micromechanics model. The difference between small crack-size matrix cracking and large crack-size matrix cracking is investigated in detail. It is shown that the bridging effect is insignificant when matrix crack size is small and solution of effective property are obtained using Mori-Tanaka`s method by treating cracks and reinforcing fibers as distinct, but interacting phases. When the crack size becomes large, the bridging effects has to be taken into consideration. With bridging tractions obtained in consistency with the micromechanics solution, and corresponding crack energy backed out, the effective properties are obtained through a modification of standard Mori-Tanaka`s treatment of multiphase composites. Analytical solutions show that the generalization of a crack density of a penny-shaped planform is insufficient in describing the effective responses of fiber-reinforced composites with matrix cracking. Approximate solutions that account for the effects of the irregularity of crack planforms are given in closed forms for several irregular crack planforms, including cracks of cross rectangle, polygon and rhombus.« less

Sequential deconvolution from wave-front sensing using bivariate simplex splines

NASA Astrophysics Data System (ADS)

Guo, Shiping; Zhang, Rongzhi; Li, Jisheng; Zou, Jianhua; Xu, Rong; Liu, Changhai

2015-05-01

Deconvolution from wave-front sensing (DWFS) is an imaging compensation technique for turbulence degraded images based on simultaneous recording of short exposure images and wave-front sensor data. This paper employs the multivariate splines method for the sequential DWFS: a bivariate simplex splines based average slopes measurement model is built firstly for Shack-Hartmann wave-front sensor; next, a well-conditioned least squares estimator for the spline coefficients is constructed using multiple Shack-Hartmann measurements; then, the distorted wave-front is uniquely determined by the estimated spline coefficients; the object image is finally obtained by non-blind deconvolution processing. Simulated experiments in different turbulence strength show that our method performs superior image restoration results and noise rejection capability especially when extracting the multidirectional phase derivatives.

Resident Front Office Experience: A Systems-Based Practice Activity

PubMed Central

Sutkin, Gary; Aronoff, Christine K.

2008-01-01

Purpose: We set out to create and evaluate a systems-based practice experience designed to introduce residents to front office responsibilities and stimulate suggestions for front office improvements. Methods: On two occasions in 2002 and 2006, each resident in the Obstetrics and Gynecology Department was trained by a front office staff member for one day. The residents completed pre- and post-experience surveys, answered open-ended questions about their experience, and volunteered suggestions for improving the front office staff, and were evaluated by their precepting staff member. Results: All but two of 23 particpating residents participated enthusiastically. These residents perceived experiencing the staff as vital to the success of the practice, reported an increased sense of appreciation for the training of staff personnel, and were evaluated favorably. Conclusion: This program gave our residents an appreciation for the training and responsibilities of pivotal office staff and an opportunity to suggest improvements. This program also satisfied ACGME resident education requirements regarding systems-based practice. PMID:20165536

Small-scale variability in suspended matter associated with the Connecticut River plume front

NASA Astrophysics Data System (ADS)

Ackleson, Steven G.; O'Donnell, James

2011-10-01

We report high spatial resolution observations of optical proxies for suspended particles and dissolved matter measured at the boundary of the Connecticut River plume (CRP) in Long Island Sound (LIS) in April 2000 when river discharge was near the annual maximum. The magnitude of beam attenuation, cp, backscatter, bb, and absorption at short wavelengths indicated higher concentration of suspended particles and colored dissolved matter within the LIS relative to the adjacent CRP. The fractional backscatter from particles indicated relatively higher organic matter fraction within the LIS. An absorption feature centered at 429 nm (aPB), indicated the presence of pigmented heterotrophic bacteria unique to the LIS and the strongest signals were observed at locations closest to shore. The spectral slope of beam attenuation associated with particulate matter (γ) indicated the presence of relatively larger particle assemblages within the LIS. Strong linear relationships between γ and salinity were observed within the energetic CRP boundary region, within 30 m of the front location. Regression residuals indicated a shift to smaller particles and were greatest at the front and decreased with distance toward the plume interior with a length scale similar to previous reports of the kinetic energy dissipation rate. At the same time, the magnitude of cp and bb remained uniform. These results are consistent with the disruption of low fractal dimension particle assemblages due to enhanced turbulence and mixing. The residuals in γ were weakly correlated with salinity and aPB suggesting that aggregate disruption was primarily associated with entrained Long Island Sound water.

50 CFR 20.100 - General provisions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... General provisions. (a) The taking, possession, transportation, and other uses of migratory game birds by.... Migratory game bird population levels, including production and habitat conditions, vary annually. These... migratory game birds to permissible levels. (b) The development of these schedules involves annual data...

50 CFR 20.100 - General provisions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... General provisions. (a) The taking, possession, transportation, and other uses of migratory game birds by.... Migratory game bird population levels, including production and habitat conditions, vary annually. These... migratory game birds to permissible levels. (b) The development of these schedules involves annual data...

50 CFR 20.100 - General provisions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... General provisions. (a) The taking, possession, transportation, and other uses of migratory game birds by.... Migratory game bird population levels, including production and habitat conditions, vary annually. These... migratory game birds to permissible levels. (b) The development of these schedules involves annual data...

50 CFR 20.100 - General provisions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... General provisions. (a) The taking, possession, transportation, and other uses of migratory game birds by.... Migratory game bird population levels, including production and habitat conditions, vary annually. These... migratory game birds to permissible levels. (b) The development of these schedules involves annual data...

50 CFR 20.100 - General provisions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... General provisions. (a) The taking, possession, transportation, and other uses of migratory game birds by.... Migratory game bird population levels, including production and habitat conditions, vary annually. These... migratory game birds to permissible levels. (b) The development of these schedules involves annual data...

Exploring Nested Reaction Fronts to Understand How Oxygen Cracks Rocks, Carbonic and Sulfuric Acids Dissolve Rocks, and Water Transports Rocks during Weathering

NASA Astrophysics Data System (ADS)

Brantley, S. L.; Gu, X.; Sullivan, P. L.; Kim, H.; Stinchcomb, G. E.; Lebedeva, M.; Balashov, V. N.

2016-12-01

To first order, weathering is the reaction of rocks with oxidants (oxygen, nitrate, etc.), acids (carbonic, sulfuric, and organic acids), and water. To explore weathering we have been studying the depth intervals in soils, saprolite, and weathering rock where mineral reactions are localized - "reaction fronts". We limit the study to ridges or catchments in climates where precipitation is greater than potential evapotranspiration. For example, in the Susquehanna Shale Hills Critical Zone Observatory, we observe reaction fronts that generally define very rough surfaces in 3D that mimic the land surface topography, although with lower relief. Overall, the fronts form nested curved surfaces. In Shale Hills, the deepest reaction fronts are oxidation of pyrite, and dissolution of carbonate. The carbonate is inferred to dissolve at least partly due to the sulfuric acid produced by the pyrite. In addition to pyrite, chlorite also starts to oxidize at the water table. We hypothesize that these dissolution and oxidation reactions open pores and cause microfracturing that open the rock to infiltration of advecting meteoric waters. At much shallower depths, illite is observed to dissolve. In Shale Hills, these reaction fronts - pyrite, carbonate, illite - separate over meters beneath the ridges. Such separated reaction fronts have also been observed in other fractured lithologies where oxidation is the deepest reaction and is associated with weathering-induced fractures. In contrast, in some massive mafic rocks, reaction fronts are almost co-located. By studying the geometry of reaction fronts, it may be possible to elucidate the relative importance of how oxygen cracks rocks; carbonic, organic, and sulfuric acids dissolve rocks; and water mobilizes rock materials during weathering.

Dr. von Braun In Front of a Display of Missiles

NASA Technical Reports Server (NTRS)

1960-01-01

In this photo, Director of the US Army Ballistic Missile Agency (ABMA) Development Operations Division, Dr. Wernher von Braun, is standing before a display of Army missiles celebrating ABMA's Fourth Open House. The missiles in the background include (left to right) a satellite on a Juno II shroud with a Nike Ajax pointing left in front of a Jupiter missile. The Lacrosse is in front of the Juno II. The Nike Hercules points skyward in front of the Juno II and the Redstone.

45 CFR 96.17 - Annual reporting requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... annually for preventive health and health services (42 U.S.C. 300w-5(a)(1)), community mental health... Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION BLOCK GRANTS General.... 300x-21 et. seq.), maternal and child health services (42 U.S.C. 706(a)(1)), and the social services...

Light-front field theory in the description of hadrons

NASA Astrophysics Data System (ADS)

Ji, Chueng-Ryong

2017-03-01

We discuss the use of light-front field theory in the descriptions of hadrons. In particular, we clarify the confusion in the prevailing notion of the equivalence between the infinite momentum frame and the light-front dynamics and the advantage of the light-front dynamics in hadron physics. As an application, we present our recent work on the flavor asymmetry in the proton sea and identify the presence of the delta-function contributions associated with end-point singularities arising from the chiral effective theory calculation. The results pave the way for phenomenological applications of pion cloud models that are manifestly consistent with the chiral symmetry properties of QCD.

Chaos of radiative heat-loss-induced flame front instability.

PubMed

Kinugawa, Hikaru; Ueda, Kazuhiro; Gotoda, Hiroshi

2016-03-01

We are intensively studying the chaos via the period-doubling bifurcation cascade in radiative heat-loss-induced flame front instability by analytical methods based on dynamical systems theory and complex networks. Significant changes in flame front dynamics in the chaotic region, which cannot be seen in the bifurcation diagrams, were successfully extracted from recurrence quantification analysis and nonlinear forecasting and from the network entropy. The temporal dynamics of the fuel concentration in the well-developed chaotic region is much more complicated than that of the flame front temperature. It exhibits self-affinity as a result of the scale-free structure in the constructed visibility graph.

International Federation of Library Associations Annual Conference Papers. General Research Libraries Division: Parliamentary Libraries and National Libraries Sections (47th, Leipzig, East Germany, August 17-22, 1981).

ERIC Educational Resources Information Center

Gude, Gilbert; And Others

This set of papers presented to the General Research Libraries Division of the International Federation of Library Associations (IFLA) during its 47th annual conference (1981) includes: "The Effect of the Introduction of Computers on Library and Research Staff," by Gilbert Gude; "Libraries as Information Service Agencies…

Synoptic-to-planetary scale wind variability enhances phytoplankton biomass at ocean fronts

NASA Astrophysics Data System (ADS)

Whitt, D. B.; Taylor, J. R.; Lévy, M.

2017-06-01

In nutrient-limited conditions, phytoplankton growth at fronts is enhanced by winds, which drive upward nutrient fluxes via enhanced turbulent mixing and upwelling. Hence, depth-integrated phytoplankton biomass can be 10 times greater at isolated fronts. Using theory and two-dimensional simulations with a coupled physical-biogeochemical ocean model, this paper builds conceptual understanding of the physical processes driving upward nutrient fluxes at fronts forced by unsteady winds with timescales of 4-16 days. The largest vertical nutrient fluxes occur when the surface mixing layer penetrates the nutricline, which fuels phytoplankton in the mixed layer. At a front, mixed layer deepening depends on the magnitude and direction of the wind stress, cross-front variations in buoyancy and velocity at the surface, and potential vorticity at the base of the mixed layer, which itself depends on past wind events. Consequently, mixing layers are deeper and more intermittent in time at fronts than outside fronts. Moreover, mixing can decouple in time from the wind stress, even without other sources of physical variability. Wind-driven upwelling also enhances depth-integrated phytoplankton biomass at fronts; when the mixed layer remains shallower than the nutricline, this results in enhanced subsurface phytoplankton. Oscillatory along-front winds induce both oscillatory and mean upwelling. The mean effect of oscillatory vertical motion is to transiently increase subsurface phytoplankton over days to weeks, whereas slower mean upwelling sustains this increase over weeks to months. Taken together, these results emphasize that wind-driven phytoplankton growth is both spatially and temporally intermittent and depends on a diverse combination of physical processes.

Security Station and Front Entrance to hospital property, looking northeast ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Security Station and Front Entrance to hospital property, looking northeast - U.S. Veterans Hospital, Jefferson Barracks, Security Station & Front Gate, VA Medical Center, Jefferson Barracks Division 1 Jefferson Barracks Drive, Saint Louis, Independent City, MO

Multidimensional stability of traveling fronts in combustion and non-KPP monostable equations

NASA Astrophysics Data System (ADS)

Bu, Zhen-Hui; Wang, Zhi-Cheng

2018-02-01

This paper is concerned with the multidimensional stability of traveling fronts for the combustion and non-KPP monostable equations. Our study contains two parts: in the first part, we first show that the two-dimensional V-shaped traveling fronts are asymptotically stable in R^{n+2} with n≥1 under any (possibly large) initial perturbations that decay at space infinity, and then, we prove that there exists a solution that oscillates permanently between two V-shaped traveling fronts, which implies that even very small perturbations to the V-shaped traveling front can lead to permanent oscillation. In the second part, we establish the multidimensional stability of planar traveling front in R^{n+1} with n≥1.

General Circulation Model Simulations of the Annual Cycle of Martian Climate

NASA Astrophysics Data System (ADS)

Wilson, R.; Richardson, M.; Rodin, A.

Observations of the martian atmosphere have revealed a strong annual modulation of global mean atmospheric temperature that has been attributed to the pronounced seasonal asymmetry in solar radiation and the highly variable distribution of aerosol. These observations indicate little interannual variability during the relatively cool aphelion season and considerable variability in the perihelion season that is associated with the episodic occurrence of regional and major dust storms. The atmospheric circulation responds to the evolving spatial distribution of aerosol-induced heating and, in turn, plays a major role in determining the sources, sinks, and transport of radiatively active aerosol. We will present simulations employing the GFDL Mars General Circulation Model (MGCM) that show that aspects of the seasonally evolving climate may be simulated in a self-consistent manner using simple dust source parameterizations that represent the effects of lifting associated with local dust storms, dust devil activity, and other processes. Aerosol transport is accomplished, in large part, by elements of the large-scale circulation such as the Hadley circulation, baroclinic storms, tides, etc. A seasonal cycle of atmospheric opacity and temperature results from the variation in the strength and distribution of dust sources as well as from seasonal variations in the efficiency of atmospheric transport associated with changes in the circulation between solstice and equinox, and between perihelion and aphelion. We examine the efficiency of atmospheric transport of dust lifted along the perimeter of the polar caps to gauge the influence of these storms on the global circulation. We also consider the influence of water, as the formation of water ice clouds on dust nuclei may also affect the vertical distribution of dust and strongly influence the aerosol radiative properties.

Virulence evolution at the front line of spreading epidemics.

PubMed

Griette, Quentin; Raoul, Gaël; Gandon, Sylvain

2015-11-01

Understanding and predicting the spatial spread of emerging pathogens is a major challenge for the public health management of infectious diseases. Theoretical epidemiology shows that the speed of an epidemic is governed by the life-history characteristics of the pathogen and its ability to disperse. Rapid evolution of these traits during the invasion may thus affect the speed of epidemics. Here we study the influence of virulence evolution on the spatial spread of an epidemic. At the edge of the invasion front, we show that more virulent and transmissible genotypes are expected to win the competition with other pathogens. Behind the front line, however, more prudent exploitation strategies outcompete virulent pathogens. Crucially, even when the presence of the virulent mutant is limited to the edge of the front, the invasion speed can be dramatically altered by pathogen evolution. We support our analysis with individual-based simulations and we discuss the additional effects of demographic stochasticity taking place at the front line on virulence evolution. We confirm that an increase of virulence can occur at the front, but only if the carrying capacity of the invading pathogen is large enough. These results are discussed in the light of recent empirical studies examining virulence evolution at the edge of spreading epidemics. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Front-office staff can improve clinical tobacco intervention: health coordinator pilot project.

PubMed

Bass, Frederic; Naish, Brigham; Buwembo, Isaac

2013-11-01

. Selected front-office personnel can substantially increase the delivery of evidence-based clinical tobacco intervention and increase patient and staff satisfaction in doing so. How far these findings can be generalized and their population effects require further study.

Post-modelling of images from a laser-induced wavy boiling front

NASA Astrophysics Data System (ADS)

Matti, R. S.; Kaplan, A. F. H.

2015-12-01

Processes like laser keyhole welding, remote fusion laser cutting or laser drilling are governed by a highly dynamic wavy boiling front that was recently recorded by ultra-high speed imaging. A new approach has now been established by post-modelling of the high speed images. Based on the image greyscale and on a cavity model the three-dimensional front topology is reconstructed. As a second step the Fresnel absorptivity modulation across the wavy front is calculated, combined with the local projection of the laser beam. Frequency polygons enable additional analysis of the statistical variations of the properties across the front. Trends like shadow formation and time dependency can be studied, locally and for the whole front. Despite strong topology modulation in space and time, for lasers with 1 μm wavelength and steel the absorptivity is bounded to a narrow range of 35-43%, owing to its Fresnel characteristics.

Measurement of the shock front velocity produced in a T-tube

DOE Office of Scientific and Technical Information (OSTI.GOV)

Djurović, S.; Mijatović, Z.; Vujičić, B.

2015-01-15

A set of shock front velocity measurements is described in this paper. The shock waves were produced in a small electromagnetically driven shock T-tube. Most of the measurements were performed in hydrogen. The shock front velocity measurements in other gases and the velocity of the gas behind the shock front were also analyzed, as well as the velocity dependence on applied input energy. Some measurements with an applied external magnetic field were also performed. The used method of shock front velocity is simple and was shown to be very reliable. Measured values were compared with the calculated ones for themore » incident and reflected shock waves.« less

Align the Front End First.

ERIC Educational Resources Information Center

Perry, Jim

1995-01-01

Discussion of management styles and front-end analysis focuses on a review of Douglas McGregor's theories. Topics include Theories X, Y, and Z; leadership skills; motivational needs of employees; intrinsic and extrinsic rewards; and faulty implementation of instructional systems design processes. (LRW)

Iterative wave-front reconstruction in the Fourier domain.

PubMed

Bond, Charlotte Z; Correia, Carlos M; Sauvage, Jean-François; Neichel, Benoit; Fusco, Thierry

2017-05-15

The use of Fourier methods in wave-front reconstruction can significantly reduce the computation time for large telescopes with a high number of degrees of freedom. However, Fourier algorithms for discrete data require a rectangular data set which conform to specific boundary requirements, whereas wave-front sensor data is typically defined over a circular domain (the telescope pupil). Here we present an iterative Gerchberg routine modified for the purposes of discrete wave-front reconstruction which adapts the measurement data (wave-front sensor slopes) for Fourier analysis, fulfilling the requirements of the fast Fourier transform (FFT) and providing accurate reconstruction. The routine is used in the adaptation step only and can be coupled to any other Wiener-like or least-squares method. We compare simulations using this method with previous Fourier methods and show an increase in performance in terms of Strehl ratio and a reduction in noise propagation for a 40×40 SPHERE-like adaptive optics system. For closed loop operation with minimal iterations the Gerchberg method provides an improvement in Strehl, from 95.4% to 96.9% in K-band. This corresponds to ~ 40 nm improvement in rms, and avoids the high spatial frequency errors present in other methods, providing an increase in contrast towards the edge of the correctable band.

End Joining-Mediated Gene Expression in Mammalian Cells Using PCR-Amplified DNA Constructs that Contain Terminator in Front of Promoter.

PubMed

Nakamura, Mikiko; Suzuki, Ayako; Akada, Junko; Tomiyoshi, Keisuke; Hoshida, Hisashi; Akada, Rinji

2015-12-01

Mammalian gene expression constructs are generally prepared in a plasmid vector, in which a promoter and terminator are located upstream and downstream of a protein-coding sequence, respectively. In this study, we found that front terminator constructs-DNA constructs containing a terminator upstream of a promoter rather than downstream of a coding region-could sufficiently express proteins as a result of end joining of the introduced DNA fragment. By taking advantage of front terminator constructs, FLAG substitutions, and deletions were generated using mutagenesis primers to identify amino acids specifically recognized by commercial FLAG antibodies. A minimal epitope sequence for polyclonal FLAG antibody recognition was also identified. In addition, we analyzed the sequence of a C-terminal Ser-Lys-Leu peroxisome localization signal, and identified the key residues necessary for peroxisome targeting. Moreover, front terminator constructs of hepatitis B surface antigen were used for deletion analysis, leading to the identification of regions required for the particle formation. Collectively, these results indicate that front terminator constructs allow for easy manipulations of C-terminal protein-coding sequences, and suggest that direct gene expression with PCR-amplified DNA is useful for high-throughput protein analysis in mammalian cells.

Tracking the Polar Front south of New Zealand using penguin dive data

NASA Astrophysics Data System (ADS)

Sokolov, Serguei; Rintoul, Stephen R.; Wienecke, Barbara

2006-04-01

Nearly 36,000 vertical temperature profiles collected by 15 king penguins are used to map oceanographic fronts south of New Zealand. There is good correspondence between Antarctic Circumpolar Current (ACC) front locations derived from temperatures sampled in the upper 150 m along the penguin tracks and front positions inferred using maps of sea surface height (SSH). Mesoscale features detected in the SSH maps from this eddy-rich region are also reproduced in the individual temperature sections based on dive data. The foraging strategy of Macquarie Island king penguins appears to be influenced strongly by oceanographic structure: almost all the penguin dives are confined to the region close to and between the northern and southern branches of the Polar Front. Surface chlorophyll distributions also reflect the influence of the ACC fronts, with the northern branch of the Polar Front marking a boundary between low surface chlorophyll to the north and elevated values to the south.

21 CFR 601.70 - Annual progress reports of postmarketing studies.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Annual progress reports of postmarketing studies... SERVICES (CONTINUED) BIOLOGICS LICENSING Postmarketing Studies § 601.70 Annual progress reports of postmarketing studies. (a) General requirements. This section applies to all required postmarketing studies (e.g...

21 CFR 601.70 - Annual progress reports of postmarketing studies.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Annual progress reports of postmarketing studies... SERVICES (CONTINUED) BIOLOGICS LICENSING Postmarketing Studies § 601.70 Annual progress reports of postmarketing studies. (a) General requirements. This section applies to all required postmarketing studies (e.g...

Monochromatic plane-fronted waves in conformal gravity are pure gauge

NASA Astrophysics Data System (ADS)

Fabbri, Luca; Paranjape, M. B.

2011-05-01

We consider plane-fronted, monochromatic gravitational waves on a Minkowski background, in a conformally invariant theory of general relativity. By this we mean waves of the form: gμν=ημν+γμνF(k·x), where γμν is a constant polarization tensor, and kμ is a lightlike vector. We also assume the coordinate gauge condition |g|-1/4∂τ(|g|1/4gστ)=0 which is the conformal analog of the harmonic gauge condition gμνΓμνσ=-|g|-1/2∂τ(|g|1/2gστ)=0, where det⁡[gμν]≡g. Requiring additionally the conformal gauge condition g=-1 surprisingly implies that the waves are both transverse and traceless. Although the ansatz for the metric is eminently reasonable when considering perturbative gravitational waves, we show that the metric is reducible to the metric of Minkowski space-time via a sequence of coordinate transformations which respect the gauge conditions, without any perturbative approximation that γμν be small. This implies that we have, in fact, exact plane-wave solutions; however, they are simply coordinate/conformal artifacts. As a consequence, they carry no energy. Our result does not imply that conformal gravity does not have gravitational wave phenomena. A different, more generalized ansatz for the deviation, taking into account the fourth-order nature of the field equation, which has the form gμν=ημν+Bμν(n·x)G(k·x), indeed yields waves which carry energy and momentum [P. D. Mannheim, Gen. Relativ. Gravit.GRGVA80001-7701 43, 703 (2010)10.1007/s10714-010-1088-z]. It is just surprising that transverse, traceless, plane-fronted gravitational waves, those that would be used in any standard, perturbative, quantum analysis of the theory, simply do not exist.

Sidewall crystallization and saturation front formation in silicic magma chambers

NASA Astrophysics Data System (ADS)

Lake, E. T.

2012-12-01

The cooling and crystallization style of silicic magma bodies in the upper crust falls on a continuum between whole-chamber processes of convection, crystal settling, and cumulate formation and interface driven processes of conduction and crystallization front migration. In the former case, volatile saturation occurs uniformly chamber wide, in the latter volatile saturation occurs along an inward propagating front. Ambient thermal gradient primarily controls the propagation rate; warm (> 30 °C / km) geothermal gradients promote 1000m+ thick crystal mush zones but slow crystallization front propagation. Cold geothermal gradients support the opposite. Magma chamber geometry plays a second order role in controlling propagation rates; bodies with high surface to magma ratio and large Earth's surface parallel faces exhibit more rapid propagation and smaller mush zones. Crystallization front propagation occurs at speeds of up to 6 cm/year (rhyolitic magma, thin sill geometry, 10 °C / km geotherm), far faster than diffusion of volatiles in magma and faster than bubbles can nucleate and ascend under certain conditions. Saturation front propagation is fixed by pressure and magma crystal content; above certain modest initial water contents (4.4 wt% in a dacite) mobile magma above 10 km depth always contains a saturation front. Saturation fronts propagate down from the magma chamber roof at lower water contents (3.3 wt% in a dacite at 5 km depth), creating an upper saturated interface for most common (4 - 6 wt%) magma water contents. This upper interface promotes the production of a fluid pocket underneath the apex of the magma chamber. Magma de-densification by bubble nucleation promotes convection and homogenization in dacitic systems. If the fluid pocket grew rapidly without draining, hydro-fracturing and eruption would result. The combination of fluid escape pathways and metal scavenging would generate economic vein or porphyry deposits.

On the Importance of "Front-Side Mechanics" in Athletics Sprinting.

PubMed

Haugen, Thomas; Danielsen, Jørgen; Alnes, Leif Olav; McGhie, David; Sandbakk, Øyvind; Ettema, Gertjan

2018-05-16

Practitioners have, for many years, argued that athletic sprinters should optimize front-side mechanics (leg motions occurring in front of the extended line through the torso) and minimize back-side mechanics. This study aimed to investigate if variables related to front- and back-side mechanics can be distinguished from other previously highlighted kinematic variables (spatiotemporal variables and variables related to segment configuration and velocities at touchdown) in how they statistically predict performance. A total of 24 competitive sprinters (age: 23.1 [3.4] y, height: 1.81 [0.06] m, body mass: 75.7 [5.6] kg, and 100-m personal best: 10.86 [0.22] s) performed two 20-m starts from block and 2 to 3 flying sprints over 20 m. Kinematics were recorded in 3D using a motion tracking system with 21 cameras at a 250 Hz sampling rate. Several front- and back-side variables, including thigh (r = .64) and knee angle (r = .51) at lift-off and maximal thigh extension (r = .66), were largely correlated (P < .05) with accelerated running performance, and these variables displayed significantly higher correlations (P < .05) to accelerated running performance than nearly all the other analyzed variables. However, the relationship directions for most front- and back-side variables during accelerated running were opposite in comparison to how the theoretical concept has been described. Horizontal ankle velocity, contact time, and step rate displayed significantly higher correlation values to maximal velocity sprinting than the other variables (P < .05), and neither of the included front- and back-side variables were significantly associated with maximal velocity sprinting. Overall, the present findings did not support that front-side mechanics were crucial for sprint performance among the investigated sprinters.

2. VIEW SOUTHEAST, WEST FRONT OF BUILDINGS 25. 26; NORTH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. VIEW SOUTHEAST, WEST FRONT OF BUILDINGS 25. 26; NORTH FRONT OF BUILDING 24: ROOF GABLE OF BUILDING 27 - U.S. Plant Introduction Station, Soil Conservation Service Cluster, 11601 Old Pond Road, Glenn Dale, Prince George's County, MD

1. VIEW SOUTHWEST, EAST FRONT OF GREENHOUSE #1 (BUILDING 5), ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. VIEW SOUTHWEST, EAST FRONT OF GREENHOUSE #1 (BUILDING 5), WITH NORTH FRONT OF SHED (BUILDING 20) IN DISTANCE - U.S. Plant Introduction Station, Greenhouse Nos. 1 & 2, 11601 Old Pond Road, Glenn Dale, Prince George's County, MD

Prioritization of Stockpile Maintenance with Layered Pareto Fronts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burke, Sarah E.; Anderson-Cook, Christine M.; Lu, Lu

Difficult choices are required for a decision-making process where resources and budgets are increasingly constrained. This study demonstrates a structured decision-making approach using layered Pareto fronts to identify priorities about how to allocate funds between munitions stockpiles based on their estimated reliability, the urgency of needing available units, and the consequences if adequate numbers of units are not available. This case study, while specific to the characteristics of a group of munitions stockpiles, illustrates the general process of structured decision-making based on first identifying appropriate metrics that summarize the important dimensions of the decision, and then objectively eliminating non-contenders frommore » further consideration. Finally, the final subjective stage incorporates user priorities to select the four stockpiles to receive additional maintenance and surveillance funds based on understanding the trade-offs and robustness to various user priorities.« less

Prioritization of Stockpile Maintenance with Layered Pareto Fronts

DOE PAGES

Burke, Sarah E.; Anderson-Cook, Christine M.; Lu, Lu; ...

2017-10-11

Difficult choices are required for a decision-making process where resources and budgets are increasingly constrained. This study demonstrates a structured decision-making approach using layered Pareto fronts to identify priorities about how to allocate funds between munitions stockpiles based on their estimated reliability, the urgency of needing available units, and the consequences if adequate numbers of units are not available. This case study, while specific to the characteristics of a group of munitions stockpiles, illustrates the general process of structured decision-making based on first identifying appropriate metrics that summarize the important dimensions of the decision, and then objectively eliminating non-contenders frommore » further consideration. Finally, the final subjective stage incorporates user priorities to select the four stockpiles to receive additional maintenance and surveillance funds based on understanding the trade-offs and robustness to various user priorities.« less

Radar observation of an along-front jet and transverse flow convergence associated with a North Sea front

NASA Astrophysics Data System (ADS)

Matthews, J. P.; Fox, A. D.; Prandle, D.

1993-01-01

This paper describes the first synoptic mapping of surface currents across a strong and stable tidal mixing front by HF radar. The radar deployment took place along the coast of northeast England during August and early September 1988 in parallel with extensive ship based CTD density and ADCP (Acoustic Doppler Current Profiler) measurements which provided data in the vertical plane to complement those of the HF radar. We describe two main results. Firstly, during a spring-tide period of strengthening inshore density gradients, an along-front jet with speeds of up to 14 cm s -1 was detected in the long term IIF radar residual field. The location and spatial form of this jet correspond with estimates of geostrophic currents derived from the measured density field. Secondly, a transverse "double-sided" surface flow convergence centred close to the frontal boundary and of net magnitude 4 cm s -1 accompanied the large along-front jet. Such a weaker cross-frontal component has been anticipated on theoretical grounds but never previously observed in this detailed fashion. The experiment underlines the power of a synergistic approach, based on HF remote sensing radar and ADCP, for the study of frontal circulation in coastal zones.

Annual 1921 : The Reasons for a Disaster

DTIC Science & Technology

2013-04-17

modernización fallida. Madrid: Temas de Hoy, 1994. 56-58. 13 The Spanish Parliament in 1917 was constituted by 760 congressmen and to the meeting was...1936-1939). 17 Porte, Pablo, “El desastre de Annual y la crisis de la Restauración en España, 1921-1923,” Tesis Doctoral, Universidad...Madrid: Ediciones Temas de Hoy, 1999. 64. 42 Luis de Marichalar y Monrea(1853-1945) was War Ministry during the Annual Disaster. 43 General

40 CFR 63.487 - Batch front-end process vents-reference control technology.

Code of Federal Regulations, 2010 CFR

2010-07-01

... § 63.487 Batch front-end process vents—reference control technology. (a) Batch front-end process vents... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Batch front-end process vents-reference control technology. 63.487 Section 63.487 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

Curved fronts in the Belousov-Zhabotinskii reaction-diffusion systems in R2

NASA Astrophysics Data System (ADS)

Niu, Hong-Tao; Wang, Zhi-Cheng; Bu, Zhen-Hui

2018-05-01

In this paper we consider a diffusion system with the Belousov-Zhabotinskii (BZ for short) chemical reaction. Following Brazhnik and Tyson [4] and Pérez-Muñuzuri et al. [45], who predicted V-shaped fronts theoretically and discovered V-shaped fronts by experiments respectively, we give a rigorous mathematical proof of their results. We establish the existence of V-shaped traveling fronts in R2 by constructing a proper supersolution and a subsolution. Furthermore, we establish the stability of the V-shaped front in R2.

Existence and non-existence of transition fronts in mixed ignition-monostable media

NASA Astrophysics Data System (ADS)

Graham, Cole; Shean Lim, Tau; Ma, Andrew; Weber, David

2018-02-01

We study transition fronts for one-dimensional reaction-diffusion equations with compactly-perturbed ignition-monostable reactions. We establish an almost sharp condition on reactions which characterizes the existence and non-existence of fronts. In particular, we prove that a strong inhomogeneity in the reaction prevents formation of transition fronts, while a weak inhomogeneity gives rise to a front. Our work extends the results and methods introduced in Nolen et al 2012 (Arch. Ration. Mech. Anal. 203 217-46), which studied the same question in inhomogeneous KPP media.

Barriers to front propagation in laminar, three-dimensional fluid flows

NASA Astrophysics Data System (ADS)

Doan, Minh; Simons, J. J.; Lilienthal, Katherine; Solomon, Tom; Mitchell, Kevin A.

2018-03-01

We present experiments on one-way barriers that block reaction fronts in a fully three-dimensional (3D) fluid flow. Fluorescent Belousov-Zhabotinsky reaction fronts are imaged with laser-scanning in a laminar, overlapping vortex flow. The barriers are analyzed with a 3D extension to burning invariant manifold (BIM) theory that was previously applied to two-dimensional advection-reaction-diffusion processes. We discover tube and sheet barriers that guide the front evolution. The experimentally determined barriers are explained by BIMs calculated from a model of the flow.

26. EXCAVATION OF EAST (FRONT) BASEMENT WELL AND DRAINAGE SYSTEM, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

26. EXCAVATION OF EAST (FRONT) BASEMENT WELL AND DRAINAGE SYSTEM, WITH ARCHED ENTRY INTO BASEMENT UNDER FRONT ENTRY IN BACKGROUND, LOOKING NORTH (NOTE GALLETING IN BRICK FOUNDATION) - Belair, Tulip Grove Drive, Belair-at-Bowie, Bowie, Prince George's County, MD

TRACES OF ORIGINAL PARTITIONS AT JUNCTURE OF FRONT ROOM, REAR ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

TRACES OF ORIGINAL PARTITIONS AT JUNCTURE OF FRONT ROOM, REAR ROOM AND HALL, SECOND FLOOR. ALSO SHOWS ORIGINAL STUCCO CORNICE OF FRONT AND REAR ROOMS (LEFT) AND HALL (RIGHT) - Kid-Chandler House, 323 Walnut Street, Philadelphia, Philadelphia County, PA

2. LAUNCH CONTROL SUPPORT BUILDING WEST FRONT AND VEHICLE STORAGE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. LAUNCH CONTROL SUPPORT BUILDING WEST FRONT AND VEHICLE STORAGE BUILDING SOUTHWEST FRONT. VIEW TO EAST. - Minuteman III ICBM Launch Control Facility November-1, 1.5 miles North of New Raymer & State Highway 14, New Raymer, Weld County, CO

MSFC Annual Day of Remembrance ceremony

NASA Image and Video Library

2018-01-25

Retired astronaut, and retired Brigadier General, Robert Stewart addresses guests and employees at the Marshall Space Flight Center’s annual “Day of Remembrance” honoring those astronauts who have passed away.

4. VIEW NORTHWEST, NORTH FRONT OF SOIL CONSERVATION SERVICE CLUSTER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. VIEW NORTHWEST, NORTH FRONT OF SOIL CONSERVATION SERVICE CLUSTER (BUILDINGS 24, 25, 26); NORTH FRONT OF QUARANTINE HEADHOUSE (BUILDING 27) - U.S. Plant Introduction Station, Soil Conservation Service Cluster, 11601 Old Pond Road, Glenn Dale, Prince George's County, MD

8. INTERIOR OF FRONT SCREENEDIN PORCH SHOWING PORCH ENTRY DOOR ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. INTERIOR OF FRONT SCREENED-IN PORCH SHOWING PORCH ENTRY DOOR AT PHOTO CENTER AND FRONT ENTRY DOOR TO LIVING ROOM AT PHOTO LEFT. VIEW TO NORTHWEST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

2. VIEW OF PARK SIGNAGE AT FRONT ROYAL. SIGN SAYS: ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. VIEW OF PARK SIGNAGE AT FRONT ROYAL. SIGN SAYS: "NORTH ENTRANCE SHENANDOAH NATIONAL PARK." LOCATED ON EXIT SIDE OF ROAD. LOOKING SOUTHWEST, MILE 0.0. - Skyline Drive, From Front Royal, VA to Rockfish Gap, VA , Luray, Page County, VA

Are Hydrostatic Models Still Capable of Simulating Oceanic Fronts

DTIC Science & Technology

2016-11-10

Coriolis effect is added to the model momentum equations...nonhydrostatic (NH) models to address the relevance of NH effects on the evolution of density fronts and the development of meso- and submeso-scale vertical...nonhydrostatic (NH) models to address the relevance of NH effects on the evolution of density fronts and the development of meso- and submeso-scale vertical

WPC Product Legends - Surface fronts and precipitation areas/symbols

Science.gov Websites

, etc...) drawn on each segment. For example, the image below shows a forming cold front. Frontolysis is other segment. Below is an example of a dissipating warm front. Precipitation Areas and Symbols Areas of an example) Below are symbols found on our short range forecasts that represent categories (and in

Travelling Fronts and Entire Solutionsof the Fisher-KPP Equation in N

NASA Astrophysics Data System (ADS)

Hamel, François; Nadirashvili, Nikolaï

This paper is devoted to time-global solutions of the Fisher-KPP equation in N: where f is a C2 concave function on [0,1] such that f(0)=f(1)=0 and f>0 on (0,1). It is well known that this equation admits a finite-dimensional manifold of planar travelling-fronts solutions. By considering the mixing of any density of travelling fronts, we prove the existence of an infinite-dimensional manifold of solutions. In particular, there are infinite-dimensional manifolds of (nonplanar) travelling fronts and radial solutions. Furthermore, up to an additional assumption, a given solution u can be represented in terms of such a mixing of travelling fronts.

Can tidal energy farms create temperature fronts in the coastal ocean?

NASA Astrophysics Data System (ADS)

Shapiro, G. I.

2012-04-01

inside the farm become weaker, whilst the currents outside the farm ( at a scale comparable to the baroclinic Rossby radius) become stronger. Such stronger currents enhance the mixing of the water column outside the farm, and weaker currents inside the farm reduce turbulent mixing and facilitate formation of a stronger thermocline. The overall effect is generally similar to the formation of fronts between tidally mixed and stratified areas of a shallow sea (Simpson and Hunter, 1974). Effect of geometrically smaller farms is less pronounced as the water particles travel in and out the affected zone during the tidal cycle (over the length of the tidal excursion) and hence are influenced by the above mechanism only during a proportion of the tidal cycle. Reduced vertical mixing within the area of the farm and positive heat balance explains higher temperatures at the surface. In the beginning of summer when thermal stratification is relatively week, the thermocline is significantly altered and the fronts propagate to a greater depth. Development of a stronger thermocline towards the end of summer inhibits the effect of mixing and the fluctuations of the depth of the upper mixed layer due to energy extraction are suppressed .

Proceedings of the first annual William Pecora Memorial Symposium, October 1975, Sioux Falls, South Dakota

USGS Publications Warehouse

Woll, Priscilla W.; Fischer, William August

1977-01-01

The U.S. Geological Survey agreed to publish the proceeding of the first annual William T. Pecora Memorial Symposium in its Professional Paper series because the subject material is related to the mission of the Survey. The usual standards for this series have been modified to accommodate the variety of styles used by the participants in this symposium. All color illustrations are placed at the front of the book for economy in printing. They are identified by the names of the authors of the papers from which they are extracted.

Seabird diving behaviour reveals the functional significance of shelf-sea fronts as foraging hotspots

NASA Astrophysics Data System (ADS)

Cox, S. L.; Miller, P. I.; Embling, C. B.; Scales, K. L.; Bicknell, A. W. J.; Hosegood, P. J.; Morgan, G.; Ingram, S. N.; Votier, S. C.

2016-09-01

Oceanic fronts are key habitats for a diverse range of marine predators, yet how they influence fine-scale foraging behaviour is poorly understood. Here, we investigated the dive behaviour of northern gannets Morus bassanus in relation to shelf-sea fronts. We GPS (global positioning system) tracked 53 breeding birds and examined the relationship between 1901 foraging dives (from time-depth recorders) and thermal fronts (identified via Earth Observation composite front mapping) in the Celtic Sea, Northeast Atlantic. We (i) used a habitat-use availability analysis to determine whether gannets preferentially dived at fronts, and (ii) compared dive characteristics in relation to fronts to investigate the functional significance of these oceanographic features. We found that relationships between gannet dive probabilities and fronts varied by frontal metric and sex. While both sexes were more likely to dive in the presence of seasonally persistent fronts, links to more ephemeral features were less clear. Here, males were positively correlated with distance to front and cross-front gradient strength, with the reverse for females. Both sexes performed two dive strategies: shallow V-shaped plunge dives with little or no active swim phase (92% of dives) and deeper U-shaped dives with an active pursuit phase of at least 3 s (8% of dives). When foraging around fronts, gannets were half as likely to engage in U-shaped dives compared with V-shaped dives, independent of sex. Moreover, V-shaped dive durations were significantly shortened around fronts. These behavioural responses support the assertion that fronts are important foraging habitats for marine predators, and suggest a possible mechanistic link between the two in terms of dive behaviour. This research also emphasizes the importance of cross-disciplinary research when attempting to understand marine ecosystems.

2. Photocopy of 1932 photograph showing a general view and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. Photocopy of 1932 photograph showing a general view and east (front) facade of the mansion. Original photograph at the Philadelphia Museum of Art - Strawberry Mansion, Philadelphia, Philadelphia County, PA

Sources and Coverage of Medical News on Front Pages of US Newspapers

PubMed Central

Lai, William Y. Y.; Lane, Trevor; Jones, Alison

2009-01-01

Background Medical news that appears on newspaper front pages is intended to reach a wide audience, but how this type of medical news is prepared and distributed has not been systematically researched. We thus quantified the level of visibility achieved by front-page medical stories in the United States and analyzed their news sources. Methodology Using the online resource Newseum, we investigated front-page newspaper coverage of four prominent medical stories, and a high-profile non-medical news story as a control, reported in the US in 2007. Two characteristics were quantified by two raters: which newspaper titles carried each target front-page story (interrater agreement, >96%; kappa, >0.92) and the news sources of each target story (interrater agreement, >94%; kappa, >0.91). National rankings of the top 200 US newspapers by audited circulation were used to quantify the extent of coverage as the proportion of the total circulation of ranked newspapers in Newseum. Findings In total, 1630 front pages were searched. Each medical story appeared on the front pages of 85 to 117 (67.5%–78.7%) ranked newspaper titles that had a cumulative daily circulation of 23.1 to 33.4 million, or 61.8% to 88.4% of all newspapers. In contrast, the non-medical story achieved front-page coverage in 152 (99.3%) newspaper titles with a total circulation of 41.0 million, or 99.8% of all newspapers. Front-page medical stories varied in their sources, but the Washington Post, Los Angeles Times, New York Times and the Associated Press together supplied 61.7% of the total coverage of target front-page medical stories. Conclusion Front-page coverage of medical news from different sources is more accurately revealed by analysis of circulation counts rather than of newspaper titles. Journals wishing to widen knowledge of research news and organizations with important health announcements should target at least the four dominant media organizations identified in this study. PMID:19724643

Bibliography of Research on Ocean Fronts, 1964-1984

DTIC Science & Technology

1985-08-01

water masses which exhibit notable differences in temperature, salinity , chlorophyll and other properties. One example of an ocean front is the...Phil. Trans. R. Soc. Lond. A302: 617-634. Amos, A.F., M.G. Langseth and R.G. Markl. 1972. Visible oceanic saline fronts, p. 49-62. In A.L. Gordon...On the mechanism of the deep mixed layer formation during MEDOC 1969. Cahiers Oceanogr. XXII: 427-442. Anderson, F.E. 1980. The variation in

Sharp-front wave of strong magnetic field diffusion in solid metal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao, Bo; Gu, Zhuo-wei; Kan, Ming-xian

When a strong magnetic field diffuses into a solid metal, if the metal's resistance possesses an abrupt rise at some critical temperature and the magnetic field strength is above some critical value, the magnetic field will diffuse into the metal in the form of a sharp-front wave. Formulas for the critical conditions under which a sharp-front magnetic diffusion wave emerges and a formula for the wave-front velocity are derived in this work.

Influence of wave-front sampling in adaptive optics retinal imaging

PubMed Central

Laslandes, Marie; Salas, Matthias; Hitzenberger, Christoph K.; Pircher, Michael

2017-01-01

A wide range of sampling densities of the wave-front has been used in retinal adaptive optics (AO) instruments, compared to the number of corrector elements. We developed a model in order to characterize the link between number of actuators, number of wave-front sampling points and AO correction performance. Based on available data from aberration measurements in the human eye, 1000 wave-fronts were generated for the simulations. The AO correction performance in the presence of these representative aberrations was simulated for different deformable mirror and Shack Hartmann wave-front sensor combinations. Predictions of the model were experimentally tested through in vivo measurements in 10 eyes including retinal imaging with an AO scanning laser ophthalmoscope. According to our study, a ratio between wavefront sampling points and actuator elements of 2 is sufficient to achieve high resolution in vivo images of photoreceptors. PMID:28271004

RF current distribution and topology of RF sheath potentials in front of ICRF antennae

NASA Astrophysics Data System (ADS)

Colas, L.; Heuraux, S.; Brémond, S.; Bosia, G.

2005-08-01

The 2D (radial/poloidal) spatial topology of RF-induced convective cells developing radially in front of ion cyclotron range of frequency (ICRF) antennae is investigated, in relation to the spatial distribution of RF currents over the metallic structure of the antenna. This is done via a Green's function, determined from the ICRF wave coupling equations, and well-suited to open field lines extending toroidally far away on both sides of the antenna. Using such formalism, combined with a full-wave calculation using the 3D antenna code ICANT (Pécoul S. et al 2000 Comput. Phys. Commun. 146 166-87), two classes of convective cells are analysed. The first one appears in front of phased arrays of straps, and depending on the strap phasing, its topology is interpreted using the poloidal profiles of either the RF current or the RF voltage of the strip line theory. The other class of convective cells is specific to antenna box corners and is evidenced for the first time. Based on such analysis, general design rules are worked out in order to reduce the RF-sheath potentials, which generalize those proposed in the earlier literature, and concrete antenna design options are tested numerically. The merits of aligning all strap centres on the same (tilted) flux tube, and of reducing the antenna box toroidal conductivity in its lower and upper parts, are discussed.

12 CFR 216.5 - Annual privacy notice to customers required.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 2 2011-01-01 2011-01-01 false Annual privacy notice to customers required... SYSTEM PRIVACY OF CONSUMER FINANCIAL INFORMATION (REGULATION P) Privacy and Opt Out Notices § 216.5 Annual privacy notice to customers required. (a)(1) General rule. You must provide a clear and...

12 CFR 216.5 - Annual privacy notice to customers required.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 12 Banks and Banking 2 2012-01-01 2012-01-01 false Annual privacy notice to customers required... SYSTEM PRIVACY OF CONSUMER FINANCIAL INFORMATION (REGULATION P) Privacy and Opt Out Notices § 216.5 Annual privacy notice to customers required. (a)(1) General rule. You must provide a clear and...

Shoulder and hip roll changes during 200-m front crawl swimming.

PubMed

Psycharakis, Stelios G; Sanders, Ross H

2008-12-01

To determine accurately the magnitude and changes in shoulder roll (SR) and hip roll (HR) throughout a 200-m maximum front crawl swim and whether SR and HR were associated with swimming velocity (V). Bilateral roll asymmetries and timing differences between SR and HR were also investigated. Ten male swimmers of national/international level performed a maximum 200-m front crawl swim. Performance was recorded with four below- and two above-water synchronized cameras and four nonbreathing stroke cycles (SC) were analyzed (one for each 50 m). SR and HR were calculated separately. Swimmers rolled their shoulders significantly more than their hips (P < 0.001). V generally decreased during the test, and HR was significantly higher in SC4 than in SC1 (P = 0.001). SR had a negative and significant correlation with V in each SC (-0.663 front crawl swimming. Faster swimmers tended to roll their shoulders less than slower swimmers. The increase in HR as the test progressed is possibly associated with a decrease in stroke frequency and increase in SC duration. Given that all swimmers were right-handed and that SR was significantly greater to the left than to the right side, it seems that factors related to handedness might affect SR symmetry in swimming.

The Front-End System For MARE In Milano

NASA Astrophysics Data System (ADS)

Arnaboldi, Claudio; Pessina, Gianluigi

2009-12-01

The first phase of MARE consists of 72 μ-bolometers composed each of a crystal of AgReO4 readout by Si thermistors. The spread in the thermistor characteristics and bolometer thermal coupling leads to different energy conversion gains and optimum operating points of the detectors. Detector biasing levels and voltage gains are completely remote-adjustable by the front end system developed, the subject of this paper, achieving the same signal range at the input of the DAQ system. The front end consists of a cold buffer stage, a second pseudo differential stage followed by a gain stage, an antialiasing filter, and a battery powered detector biasing set up. The DAQ system can be used to set all necessary parameters of the electronics remotely, by writing to a μ-controller located on each board. Fiber optics are used for the serial communication between the DAQ and the front end. To suppress interference noise during normal operation, the clocked devices of the front end are maintained in sleep-mode, except during the set-up phase of the experiment. An automatic DC detector characterization procedure is used to establish the optimum operating point of every detector of the array. A very low noise level has been achieved: about 3nV/□Hz at 1 Hz and 1 nV/□Hz for the white component, high frequencies.

View of front (north) and east walls of the Office, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of front (north) and east walls of the Office, Childs power plant. Rock cairn in front frames the 1976 National Historic Mechanical Engineering plaque. Looking southeast - Childs-Irving Hydroelectric Project, Childs System, Office, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

Pareto fronts for multiobjective optimization design on materials data

NASA Astrophysics Data System (ADS)

Gopakumar, Abhijith; Balachandran, Prasanna; Gubernatis, James E.; Lookman, Turab

Optimizing multiple properties simultaneously is vital in materials design. Here we apply infor- mation driven, statistical optimization strategies blended with machine learning methods, to address multi-objective optimization tasks on materials data. These strategies aim to find the Pareto front consisting of non-dominated data points from a set of candidate compounds with known character- istics. The objective is to find the pareto front in as few additional measurements or calculations as possible. We show how exploration of the data space to find the front is achieved by using uncer- tainties in predictions from regression models. We test our proposed design strategies on multiple, independent data sets including those from computations as well as experiments. These include data sets for Max phases, piezoelectrics and multicomponent alloys.

Front-End Analysis Cornerstone of Logistics

NASA Technical Reports Server (NTRS)

Nager, Paul J.

2000-01-01

The presentation provides an overview of Front-End Logistics Support Analysis (FELSA), when it should be performed, benefits of performing FELSA and why it should be performed, how it is conducted, and examples.

Automated Detection of Fronts using a Deep Learning Convolutional Neural Network

NASA Astrophysics Data System (ADS)

Biard, J. C.; Kunkel, K.; Racah, E.

2017-12-01

A deeper understanding of climate model simulations and the future effects of global warming on extreme weather can be attained through direct analyses of the phenomena that produce weather. Such analyses require these phenomena to be identified in automatic, unbiased, and comprehensive ways. Atmospheric fronts are centrally important weather phenomena because of the variety of significant weather events, such as thunderstorms, directly associated with them. In current operational meteorology, fronts are identified and drawn visually based on the approximate spatial coincidence of a number of quasi-linear localized features - a trough (relative minimum) in air pressure in combination with gradients in air temperature and/or humidity and a shift in wind, and are categorized as cold, warm, stationary, or occluded, with each type exhibiting somewhat different characteristics. Fronts are extended in space with one dimension much larger than the other (often represented by complex curved lines), which poses a significant challenge for automated approaches. We addressed this challenge by using a Deep Learning Convolutional Neural Network (CNN) to automatically identify and classify fronts. The CNN was trained using a "truth" dataset of front locations identified by National Weather Service meteorologists as part of operational 3-hourly surface analyses. The input to the CNN is a set of 5 gridded fields of surface atmospheric variables, including 2m temperature, 2m specific humidity, surface pressure, and the two components of the 10m horizontal wind velocity vector at 3-hr resolution. The output is a set of feature maps containing the per - grid cell probabilities for the presence of the 4 front types. The CNN was trained on a subset of the data and then used to produce front probabilities for each 3-hr time snapshot over a 14-year period covering the continental United States and some adjacent areas. The total frequencies of fronts derived from the CNN outputs matches

A holographic technique for recording a hypervelocity projectile with front surface resolution.

PubMed

Kurtz, R L; Loh, H Y

1970-05-01

Any motion of the scene during the exposure of a hologram results in a spatial modulation of the recorded fringe contrast. On reconstruction, this produces a spatial amplitude modulation of the reconstructed wavefront, which results in a blurring of the image, not unlike that of a conventional photograph. For motion of the scene sufficient to change the path length of the signal arm by a half wavelength, this blurring is generally prohibitive. This paper describes a proposed holographic technique which offers promise for front light resolution of targets moving at high speeds, heretofore unobtainable by conventional methods.

Standing Fast: German Defensive Doctrine on the Russian Front During the Second World War.

DTIC Science & Technology

1983-06-03

von Kluge, Hitler explained that the demands of other fronts (especially Italy) required the transfer of perhaps ’ b| ’P q . . • .,,, -’ ’’’ ’’’ h ...historians such as Heinrich von Treitschke , who regarded past military glory as the wellspring of German nationalism. One of the most onerous aspects of the...Prince Wilhelm of Germany , !.L War Experiences (London: Hurst * and Blackett, 1923), p. 267. " 8See, for example, "General Von Maur’s Memorandum on

Cold Front Cools the Eastern U.S.

NASA Image and Video Library

2014-07-16

Summertime heat and humidity in the U.S. East Coast is on hold for a couple of days thanks to a cold front and that brought clouds, showers, thunderstorms, and some severe weather on July 16 to the coast. The National Oceanic and Atmospheric Administration (NOAA) noted that the dip in the jet stream will create below normal temperatures for most of the Central and Eastern U.S. for the next couple of days. NOAA's GOES-East satellite captured an image of the clouds associated with the cold front on July 16 at 1630 UTC (12:30 p.m. EDT).The clouds follow the front which stretches from the Florida panhandle, across Florida and up the U.S. East Coast into eastern Canada. Along the front lie two areas of low pressure, one over eastern New England, and the other offshore from South Carolina. Both of those low pressure areas are associated with additional cloudiness along the front. GOES satellites are managed by NOAA. The image was created by the NASA/NOAA GOES Project at NASA's Goddard Space Flight Center in Greenbelt, Maryland. GOES satellites provide the kind of continuous monitoring necessary for intensive data analysis. Geostationary describes an orbit in which a satellite is always in the same position with respect to the rotating Earth. This allows GOES to hover continuously over one position on Earth's surface, appearing stationary. As a result, GOES provide a constant vigil for the atmospheric "triggers" for severe weather conditions such as tornadoes, flash floods, hail storms and hurricanes. For updated information about the storm system, visit NOAA's National Weather Service website: www.weather.gov For more information about GOES satellites, visit: www.goes.noaa.gov/ or goes.gsfc.nasa.gov/ Image Credit: NASA/NOAA GOES Project, Text: Rob Gutro NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in

17 CFR 160.5 - Annual privacy notice to customers required.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 17 Commodity and Securities Exchanges 2 2014-04-01 2014-04-01 false Annual privacy notice to... COMMISSION (CONTINUED) PRIVACY OF CONSUMER FINANCIAL INFORMATION UNDER TITLE V OF THE GRAMM-LEACH-BLILEY ACT Privacy and Opt Out Notices § 160.5 Annual privacy notice to customers required. (a)(1) General rule. You...

17 CFR 160.5 - Annual privacy notice to customers required.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 17 Commodity and Securities Exchanges 1 2012-04-01 2012-04-01 false Annual privacy notice to... COMMISSION PRIVACY OF CONSUMER FINANCIAL INFORMATION UNDER TITLE V OF THE GRAMM-LEACH-BLILEY ACT Privacy and Opt Out Notices § 160.5 Annual privacy notice to customers required. (a)(1) General rule. You must...

17 CFR 160.5 - Annual privacy notice to customers required.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 17 Commodity and Securities Exchanges 1 2013-04-01 2013-04-01 false Annual privacy notice to... COMMISSION PRIVACY OF CONSUMER FINANCIAL INFORMATION UNDER TITLE V OF THE GRAMM-LEACH-BLILEY ACT Privacy and Opt Out Notices § 160.5 Annual privacy notice to customers required. (a)(1) General rule. You must...

Three-dimensional hybrid grid generation using advancing front techniques

NASA Technical Reports Server (NTRS)

Steinbrenner, John P.; Noack, Ralph W.

1995-01-01

A new 3-dimensional hybrid grid generation technique has been developed, based on ideas of advancing fronts for both structured and unstructured grids. In this approach, structured grids are first generate independently around individual components of the geometry. Fronts are initialized on these structure grids, and advanced outward so that new cells are extracted directly from the structured grids. Employing typical advancing front techniques, cells are rejected if they intersect the existing front or fail other criteria When no more viable structured cells exist further cells are advanced in an unstructured manner to close off the overall domain, resulting in a grid of 'hybrid' form. There are two primary advantages to the hybrid formulation. First, generating blocks with limited regard to topology eliminates the bottleneck encountered when a multiple block system is used to fully encapsulate a domain. Individual blocks may be generated free of external constraints, which will significantly reduce the generation time. Secondly, grid points near the body (presumably with high aspect ratio) will still maintain a structured (non-triangular or tetrahedral) character, thereby maximizing grid quality and solution accuracy near the surface.

OBLIQUE/EXTERIOR VIEW, SIDE AND FRONT ELEVATIONS, FOUR ROOMPYRAMIDAL ROOF COTTAGE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

OBLIQUE/EXTERIOR VIEW, SIDE AND FRONT ELEVATIONS, FOUR ROOM-PYRAMIDAL ROOF COTTAGE (AT 328 CAMILLE) WITH FRONT YARD LANDSCAPING. - Mulga Community, Off AL 269 at I-20-59, Birmingham, Jefferson County, AL

Temperature in subsonic and supersonic radiation fronts measured at OMEGA

NASA Astrophysics Data System (ADS)

Johns, Heather; Kline, John; Lanier, Nick; Perry, Ted; Fontes, Chris; Fryer, Chris; Brown, Colin; Morton, John

2017-10-01

Propagation of heat fronts relevant to astrophysical plasmas is challenging in the supersonic regime. Plasma Te changes affect opacity and equation of state without hydrodynamic change. In the subsonic phase density perturbations form at material interfaces as the plasma responds to radiation pressure of the front. Recent experiments at OMEGA studied this transition in aerogel foams driven by a hohlraum. In COAX, two orthogonal backlighters drive x-ray radiography and K-shell absorption spectroscopy to diagnose the subsonic shape of the front and supersonic Te profiles. Past experiments used absorption spectroscopy in chlorinated foams to measure the heat front; however, Cl dopant is not suitable for higher material temperatures at NIF. COAX has developed use of Sc and Ti dopants to diagnose Te between 60-100eV and 100-180eV. Analysis with PrismSPECT using OPLIB tabular opacity data will evaluate the platform's ability to advance radiation transport in this regime.

Effectively Transparent Front Contacts for Optoelectronic Devices

DOE PAGES

Saive, Rebecca; Borsuk, Aleca M.; Emmer, Hal S.; ...

2016-06-10

Effectively transparent front contacts for optoelectronic devices achieve a measured transparency of up to 99.9% and a measured sheet resistance of 4.8 Ω sq-1. These 3D microscale triangular cross-section grid fingers redirect incoming photons efficiently to the active semiconductor area and can replace standard grid fingers as well as transparent conductive oxide layers in optoelectronic devices. Optoelectronic devices such as light emitting diodes, photodiodes, and solar cells play an important and expanding role in modern technology. Photovoltaics is one of the largest optoelectronic industry sectors and an ever-increasing component of the world's rapidly growing renewable carbon-free electricity generation infrastructure. Inmore » recent years, the photovoltaics field has dramatically expanded owing to the large-scale manufacture of inexpensive crystalline Si and thin film cells and modules. The current record efficiency (η = 25.6%) Si solar cell utilizes a heterostructure intrinsic thin layer (HIT) design[1] to enable increased open circuit voltage, while more mass-manufacturable solar cell architectures feature front contacts.[2, 3] Thus improved solar cell front contact designs are important for future large-scale photovoltaics with even higher efficiency.« less

Cold Fronts in RegCM/HadGEM simulations over South America

NASA Astrophysics Data System (ADS)

Pampuch, Luana; Marcos de Jesus, Eduardo; Porfírio da Rocha, Rosmeri; Ambrizzi, Tércio

2017-04-01

Cold front is one of the most important systems that contribute for precipitation over South America. The representation of this system in climate models is important for a better representation of the precipitation. The Regional Climate Model RegCM is widely used for climate studies in South America, being important to understand how this model represents the cold fronts. A climatology (from 1979-2004) of the number of cold fronts in each season for RegCM4 simulations over South America CORDEX domain nested in HadGEM2-ES. The simulated climatology was compared with ERA-Interim reanalysis cold fronts climatology over the South America and adjacent South Atlantic Ocean. The cold fronts tracking for the model and the reanalysis were performed using an objective methodology based on decrease of air temperature in 925hPa, shift of meridional wind in 925hPa from northern to southern quadrant and increased in sea level pressure. The main differences were observed on summer and winter. On summer the model overestimate the number of cold fronts over southeastern South America and adjacent Atlantic Ocean; and underestimate it over central-south Argentina and Atlantic Ocean. On winter, the signs were opposite of that summer. On autumn and spring the differences were smaller and occurs mainly over all South Atlantic and north Argentina.

Taking charge: front-line nurse leadership development.

PubMed

Schwarzkopf, Ruth; Sherman, Rose O; Kiger, Anna J

2012-04-01

The recent Institute of Medicine (2010) report, The Future of Nursing: Leading Change, Advancing Health, included a recommendation that nurses at all levels should be prepared and enabled to lead change to advance health care in the United States. Historically, in most organizations, nursing leadership development programs have focused on nurses in management or executive roles rather than those working in front-line leadership roles. This article describes a front-line leadership development initiative developed by Tenet Healthcare Corporation and attended by 400 charge nurses. Program development, evaluation, and lessons learned that can be applied in other organizations are discussed. Copyright 2012, SLACK Incorporated.

15 CFR 971.200 - General.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE GENERAL REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR COMMERCIAL RECOVERY PERMITS Applications § 971.200 General. (a... (such as data included in annual reports to NOAA), may be incorporated in the commercial recovery permit...

15 CFR 971.200 - General.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE GENERAL REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR COMMERCIAL RECOVERY PERMITS Applications § 971.200 General. (a... (such as data included in annual reports to NOAA), may be incorporated in the commercial recovery permit...

15 CFR 971.200 - General.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE GENERAL REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR COMMERCIAL RECOVERY PERMITS Applications § 971.200 General. (a... (such as data included in annual reports to NOAA), may be incorporated in the commercial recovery permit...

15 CFR 971.200 - General.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE GENERAL REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR COMMERCIAL RECOVERY PERMITS Applications § 971.200 General. (a... (such as data included in annual reports to NOAA), may be incorporated in the commercial recovery permit...

15 CFR 971.200 - General.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE GENERAL REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR COMMERCIAL RECOVERY PERMITS Applications § 971.200 General. (a... (such as data included in annual reports to NOAA), may be incorporated in the commercial recovery permit...

Translational genetics: advancing fronts for craniofacial health.

PubMed

D'Souza, R N; Dunnwald, M; Dunnvald, M; Frazier-Bowers, S; Polverini, P J; Wright, J T; de Rouen, T; Vieira, A R

2013-12-01

Scientific opportunities have never been better than today! The completion of the Human Genome project has sparked hope and optimism that cures for debilitating conditions can be achieved and tailored to individuals and communities. The availability of reference genome sequences and genetic variations as well as more precise correlations between genotype and phenotype have facilitated the progress made in finding solutions to clinical problems. While certain craniofacial and oral diseases previously deemed too difficult to tackle have benefited from basic science and technological advances over the past decade, there remains a critical need to translate the fruits of several decades' worth of basic and clinical research into tangible therapies that can benefit patients. The fifth Annual Fall Focused Symposium, "Translational Genetics - Advancing Fronts for Craniofacial Health", was created by the American Association for Dental Research (AADR) to foster its mission to advance interdisciplinary research that is directed toward improving oral health. The symposium showcased progress made in identifying molecular targets that are potential therapeutics for common and rare dental diseases and craniofacial disorders. Speakers focused on translational and clinical applications of their research and, where applicable, on strategies for new technologies and therapeutics. The critical needs to transfer new knowledge to the classroom and for further investment in the field were also emphasized. The symposium underscored the importance of basic research, chairside clinical observations, and population-based studies in driving the new translational connections needed for the development of cures for the most common and devastating diseases involving the craniofacial complex.

The dynamics of oceanic fronts. Part 1: The Gulf Stream

NASA Technical Reports Server (NTRS)

Kao, T. W.

1970-01-01

The establishment and maintenance of the mean hydrographic properties of large scale density fronts in the upper ocean is considered. The dynamics is studied by posing an initial value problem starting with a near surface discharge of buoyant water with a prescribed density deficit into an ambient stationary fluid of uniform density. The full time dependent diffusion and Navier-Stokes equations for a constant Coriolis parameter are used in this study. Scaling analysis reveals three independent length scales of the problem, namely a radius of deformation or inertial length scale, Lo, a buoyance length scale, ho, and a diffusive length scale, hv. Two basic dimensionless parameters are then formed from these length scales, the thermal (or more precisely, the densimetric) Rossby number, Ro = Lo/ho and the Ekman number, E = hv/ho. The governing equations are then suitably scaled and the resulting normalized equations are shown to depend on E alone for problems of oceanic interest. Under this scaling, the solutions are similar for all Ro. It is also shown that 1/Ro is a measure of the frontal slope. The governing equations are solved numerically and the scaling analysis is confirmed. The solution indicates that an equilibrium state is established. The front can then be rendered stationary by a barotropic current from a larger scale along-front pressure gradient. In that quasisteady state, and for small values of E, the main thermocline and the inclined isopycnics forming the front have evolved, together with the along-front jet. Conservation of potential vorticity is also obtained in the light water pool. The surface jet exhibits anticyclonic shear in the light water pool and cyclonic shear across the front.

Seasonal variability of thermal fronts in the northern South China Sea from satellite data

NASA Astrophysics Data System (ADS)

Wang, Dongxiao; Liu, Yun; Qi, Yiquan; Shi, Ping

The 8-year (1991-1998) Pathfinder sea surface temperature data have been applied here to produce the objectively derived seasonality of the oceanic thermal fronts in the northern South China Sea from 17°N to 25°N. Several fronts have been clearly distinguished, namely, Fujian and Guangdong Coastal Water, Pear River Estuary Coastal, Taiwan Bank, Kuroshio Intrusion, Hainan Island East Coast and Tonkin Gulf Coastal fronts. The frontal patterns in winter, spring and summer are quite similar, whereas individual fronts display different modes of seasonal variability due to different mechanisms favoring those fronts.

Macroscopic response to microscopic intrinsic noise in three-dimensional Fisher fronts.

PubMed

Nesic, S; Cuerno, R; Moro, E

2014-10-31

We study the dynamics of three-dimensional Fisher fronts in the presence of density fluctuations. To this end we simulate the Fisher equation subject to stochastic internal noise, and study how the front moves and roughens as a function of the number of particles in the system, N. Our results suggest that the macroscopic behavior of the system is driven by the microscopic dynamics at its leading edge where number fluctuations are dominated by rare events. Contrary to naive expectations, the strength of front fluctuations decays extremely slowly as 1/logN, inducing large-scale fluctuations which we find belong to the one-dimensional Kardar-Parisi-Zhang universality class of kinetically rough interfaces. Hence, we find that there is no weak-noise regime for Fisher fronts, even for realistic numbers of particles in macroscopic systems.

Front propagation in one-dimensional spatially periodic bistable media

NASA Astrophysics Data System (ADS)

Löber, Jakob; Bär, Markus; Engel, Harald

2012-12-01

Front propagation in heterogeneous bistable media is studied using the Schlögl model as a representative example. Spatially periodic modulations in the parameters of the bistable kinetics are taken into account perturbatively. Depending on the ratio L/l (L is the spatial period of the heterogeneity, l is the front width), appropriate singular perturbation techniques are applied to derive an ordinary differential equation for the position of the front in the presence of the heterogeneities. From this equation, the dependence of the average propagation speed on L/l as well as on the modulation amplitude is calculated. The analytical results obtained predict velocity overshoot, different cases of propagation failure, and the propagation speed for very large spatial periods in quantitative agreement with the results of direct numerical simulations of the underlying reaction-diffusion equation.

Characterisation of the Interaction between Toroidal Vortex Structures and Flame Front Propagation

NASA Astrophysics Data System (ADS)

Long, E. J.; Hargrave, G. K.; Jarvis, S.; Justham, T.; Halliwell, N.

2006-07-01

Experimental laser diagnostic data is presented for flame characterisation during interactions with toroidal vortices generated in the wake of an annular obstacle. A novel twin section combustion chamber has been utilised to allow the controlled formation of stable eddy structures into which a flame front can propagate. High speed laser sheet visualisation was employed to record the flow field and flame front temporal development and high-speed digital particle image velocimetry was used to quantify the velocity field of the unburnt mixture ahead of the flame front. Results provide characterisation of the toroidal vortex/flame front interaction for a range of vortex scales of and recirculation strengths.

Motivation and Front-End Analysis.

ERIC Educational Resources Information Center

Harless, Joe

1978-01-01

Relates Front-End Analysis (FEA) to motivation by categorizing it as either Diagnostic FEA or Planning FEA. The former is used to diagnose existing problems and prescribe motivational programs; the latter assumes that motivational programs must be implemented, along with other programs, to build the optimum environment to support the performance.…

Water masses, ocean fronts, and the structure of Antarctic seabird communities: putting the eastern Bellingshausen Sea in perspective

USGS Publications Warehouse

Ribic, Christine A.; Ainley, David G.; Ford, R. Glenn; Fraser, William R.; Tynan, Cynthia T.; Woehler, Eric J.

2015-01-01

Waters off the western Antarctic Peninsula (i.e., the eastern Bellingshausen Sea) are unusually complex owing to the convergence of several major fronts. Determining the relative influence of fronts on occurrence patterns of top-trophic species in that area, therefore, has been challenging. In one of the few ocean-wide seabird data syntheses, in this case for the Southern Ocean, we analyzed ample, previously collected cruise data, Antarctic-wide, to determine seabird species assemblages and quantitative relationships to fronts as a way to provide context to the long-term Palmer LTER and the winter Southern Ocean GLOBEC studies in the eastern Bellingshausen Sea. Fronts investigated during both winter (April–September) and summer (October–March) were the southern boundary of the Antarctic Circumpolar Current (ACC), which separates the High Antarctic from the Low Antarctic water mass, and within which are embedded the marginal ice zone and Antarctic Shelf Break Front; and the Antarctic Polar Front, which separates the Low Antarctic and the Subantarctic water masses. We used clustering to determine species' groupings with water masses, and generalized additive models to relate species' densities, biomass and diversity to distance to respective fronts. Antarctic-wide, in both periods, highest seabird densities and lowest species diversity were found in the High Antarctic water mass. In the eastern Bellingshausen, seabird density in the High Antarctic water mass was lower (as low as half that of winter) than found in other Antarctic regions. During winter, Antarctic-wide, two significant species groups were evident: one dominated by Adélie penguins (Pygoscelis adeliae) (High Antarctic water mass) and the other by petrels and prions (no differentiation among water masses); in eastern Bellingshausen waters during winter, the one significant species group was composed of species from both Antarctic-wide groups. In summer, Antarctic-wide, a High Antarctic group

Intense deformation field at oceanic front inferred from directional sea surface roughness observations

NASA Astrophysics Data System (ADS)

Rascle, Nicolas; Molemaker, Jeroen; Marié, Louis; Nouguier, Frédéric; Chapron, Bertrand; Lund, Björn; Mouche, Alexis

2017-06-01

Fine-scale current gradients at the ocean surface can be observed by sea surface roughness. More specifically, directional surface roughness anomalies are related to the different horizontal current gradient components. This paper reports results from a dedicated experiment during the Lagrangian Submesoscale Experiment (LASER) drifter deployment. A very sharp front, 50 m wide, is detected simultaneously in drifter trajectories, sea surface temperature, and sea surface roughness. A new observational method is applied, using Sun glitter reflections during multiple airplane passes to reconstruct the multiangle roughness anomaly. This multiangle anomaly is consistent with wave-current interactions over a front, including both cross-front convergence and along-front shear with cyclonic vorticity. Qualitatively, results agree with drifters and X-band radar observations. Quantitatively, the sharpness of roughness anomaly suggests intense current gradients, 0.3 m s-1 over the 50 m wide front. This work opens new perspectives for monitoring intense oceanic fronts using drones or satellite constellations.

Dynamic stabilization of Rayleigh-Taylor instability in an ablation front

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piriz, A. R.; Di Lucchio, L.; Rodriguez Prieto, G.

2011-01-15

Dynamic stabilization of Rayleigh-Taylor instability in an ablation front is studied by considering a modulation in the acceleration that consists of sequences of Dirac deltas. This allows obtaining explicit analytical expressions for the instability growth rate as well as for the boundaries of the stability region. As a general rule, it is found that it is possible to stabilize all wave numbers above a certain minimum value k{sub m}, but the requirements in the modulation amplitude and frequency become more exigent with smaller k{sub m}. The essential role of compressibility is phenomenologically addressed in order to find the constraint itmore » imposes on the stability region. The results for some different wave forms of the acceleration modulation are also presented.« less

Lakes in the greater Denver area, Front Range Urban Corridor

USGS Publications Warehouse

Danielson, T.W.

1975-01-01

The purpose of this report is to present the results of an inventory of the lakes in the central one-third of the Colorado Front Range Urban Corridor. This inventory provides information that might be helpful in planning the best and most beneficial use of lakes in an area of rapid population growth. The report includes data on lake size and water quality. Size data are included on most of the lakes of 2 hectares (20,000 m2, or about 5 acres) or greater, and water-quality data are provided on most lakes larger than 10 hectares (about 25 acres). Bodies of water resulting form excavation of gravel (borrow pits) were generally not included in the inventory.

5. GENERAL VIEW OF GARAGE AREA FROM WEST; STEPS TO ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. GENERAL VIEW OF GARAGE AREA FROM WEST; STEPS TO WEST FRONT ENTRANCE VISABLE TO THE RIGHT - Isaac N. Hagan House, Kentuck Knob, U.S. Route 40 vicinity (Stewart Township), Chalkhill, Fayette County, PA

Targeting NCK-Mediated Endothelial Cell Front-Rear Polarity Inhibits Neovascularization.

PubMed

Dubrac, Alexandre; Genet, Gael; Ola, Roxana; Zhang, Feng; Pibouin-Fragner, Laurence; Han, Jinah; Zhang, Jiasheng; Thomas, Jean-Léon; Chedotal, Alain; Schwartz, Martin A; Eichmann, Anne

2016-01-26

Sprouting angiogenesis is a key process driving blood vessel growth in ischemic tissues and an important drug target in a number of diseases, including wet macular degeneration and wound healing. Endothelial cells forming the sprout must develop front-rear polarity to allow sprout extension. The adaptor proteins Nck1 and 2 are known regulators of cytoskeletal dynamics and polarity, but their function in angiogenesis is poorly understood. Here, we show that the Nck adaptors are required for endothelial cell front-rear polarity and migration downstream of the angiogenic growth factors VEGF-A and Slit2. Mice carrying inducible, endothelial-specific Nck1/2 deletions fail to develop front-rear polarized vessel sprouts and exhibit severe angiogenesis defects in the postnatal retina and during embryonic development. Inactivation of NCK1 and 2 inhibits polarity by preventing Cdc42 and Pak2 activation by VEGF-A and Slit2. Mechanistically, NCK binding to ROBO1 is required for both Slit2- and VEGF-induced front-rear polarity. Selective inhibition of polarized endothelial cell migration by targeting Nck1/2 prevents hypersprouting induced by Notch or Bmp signaling inhibition, and pathological ocular neovascularization and wound healing, as well. These data reveal a novel signal integration mechanism involving NCK1/2, ROBO1/2, and VEGFR2 that controls endothelial cell front-rear polarity during sprouting angiogenesis. © 2015 American Heart Association, Inc.

Conceptual design of front ends for the advanced photon source multi-bend achromats upgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaski, Y., E-mail: jaskiy@aps.anl.gov; Westferro, F., E-mail: westferr@aps.anl.gov; Lee, S. H., E-mail: shlee@aps.anl.gov

2016-07-27

The proposed Advanced Photon Source (APS) upgrade from a double-bend achromats (DBA) to multi-bend achromats (MBA) lattice with ring energy change from 7 GeV to 6 GeV and beam current from 100 mA to 200 mA poses new challenges for front ends. All front ends must be upgraded to fulfill the following requirements: 1) handle the high heat load from two insertion devices in either inline or canted configuration, 2) include a clearing magnet in the front end to deflect and dump any electrons in case the electrons escape from the storage ring during swap-out injection with the safety shuttersmore » open, 3) incorporate the next generation x-ray beam position monitors (XBPMs) into the front end to meet the new stringent beam stability requirements. This paper presents the evaluation of the existing APS front ends and standardizes the insertion device (ID) front ends into two types: one for the single beam and one for the canted beams. The conceptual design of high heat load front end (HHLFE) and canted undulator front end (CUFE) for APS MBA upgrade is presented.« less

Conceptual Design of Front Ends for the Advanced Photon Source Multi-bend Achromats Upgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaski, Y.; Westferro, F.; Lee, S. H.

2016-07-27

The proposed Advanced Photon Source (APS) upgrade from a double-bend achromats (DBA) to multi-bend achromats (MBA) lattice with ring energy change from 7 GeV to 6 GeV and beam current from 100 mA to 200 mA poses new challenges for front ends. All front ends must be upgraded to fulfill the following requirements: 1) handle the high heat load from two insertion devices in either inline or canted configuration, 2) include a clearing magnet in the front end to deflect and dump any electrons in case the electrons escape from the storage ring during swap-out injection with the safety shuttersmore » open, 3) incorporate the next generation x-ray beam position monitors (XBPMs) into the front end to meet the new stringent beam stability requirements. This paper presents the evaluation of the existing APS front ends and standardizes the insertion device (ID) front ends into two types: one for the single beam and one for the canted beams. The conceptual design of high heat load front end (HHLFE) and canted undulator front end (CUFE) for APS MBA upgrade is presented.« less

Instant-Form and Light-Front Quantization of Field Theories

NASA Astrophysics Data System (ADS)

Kulshreshtha, Usha; Kulshreshtha, Daya Shankar; Vary, James

2018-05-01

In this work we consider the instant-form and light-front quantization of some field theories. As an example, we consider a class of gauged non-linear sigma models with different regularizations. In particular, we present the path integral quantization of the gauged non-linear sigma model in the Faddeevian regularization. We also make a comparision of the possible differences in the instant-form and light-front quantization at appropriate places.

26 CFR 31.3121(a)(1)-1 - Annual wage limitation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Annual wage limitation. 31.3121(a)(1)-1 Section... § 31.3121(a)(1)-1 Annual wage limitation. (a) In general. (1) The term “wages” does not include that... for such calendar year (exclusive of remuneration excepted from wages in accordance with paragraph (j...

45 CFR 1168.605 - Inspector General report.

Code of Federal Regulations, 2012 CFR

2012-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 45 Public Welfare 3 2012-10-01 2012-10-01 false Inspector General report. 1168.605 Section 1168... AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES NEW RESTRICTIONS ON LOBBYING Agency Reports...

45 CFR 1168.605 - Inspector General report.

Code of Federal Regulations, 2013 CFR

2013-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 45 Public Welfare 3 2013-10-01 2013-10-01 false Inspector General report. 1168.605 Section 1168... AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 227.605 - Inspector General report.

Code of Federal Regulations, 2013 CFR

2013-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Inspector General report. 227.605 Section 227.605 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 519.605 - Inspector General report.

Code of Federal Regulations, 2012 CFR

2012-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 2 2012-04-01 2009-04-01 true Inspector General report. 519.605 Section 519.605 Foreign Relations BROADCASTING BOARD OF GOVERNORS NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 227.605 - Inspector General report.

Code of Federal Regulations, 2011 CFR

2011-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Inspector General report. 227.605 Section 227.605 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 138.605 - Inspector General report.

Code of Federal Regulations, 2012 CFR

2012-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Inspector General report. 138.605 Section 138.605 Foreign Relations DEPARTMENT OF STATE MISCELLANEOUS NEW RESTRICTIONS ON LOBBYING Agency Reports...

45 CFR 1168.605 - Inspector General report.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 45 Public Welfare 3 2014-10-01 2014-10-01 false Inspector General report. 1168.605 Section 1168... AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 138.605 - Inspector General report.

Code of Federal Regulations, 2010 CFR

2010-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Inspector General report. 138.605 Section 138.605 Foreign Relations DEPARTMENT OF STATE MISCELLANEOUS NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 519.605 - Inspector General report.

Code of Federal Regulations, 2014 CFR

2014-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 2 2014-04-01 2014-04-01 false Inspector General report. 519.605 Section 519.605 Foreign Relations BROADCASTING BOARD OF GOVERNORS NEW RESTRICTIONS ON LOBBYING Agency Reports...

45 CFR 1168.605 - Inspector General report.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 45 Public Welfare 3 2011-10-01 2011-10-01 false Inspector General report. 1168.605 Section 1168... AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 227.605 - Inspector General report.

Code of Federal Regulations, 2010 CFR

2010-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Inspector General report. 227.605 Section 227.605 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 519.605 - Inspector General report.

Code of Federal Regulations, 2010 CFR

2010-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Inspector General report. 519.605 Section 519.605 Foreign Relations BROADCASTING BOARD OF GOVERNORS NEW RESTRICTIONS ON LOBBYING Agency Reports...

45 CFR 1168.605 - Inspector General report.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 45 Public Welfare 3 2010-10-01 2010-10-01 false Inspector General report. 1168.605 Section 1168... AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE HUMANITIES NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 138.605 - Inspector General report.

Code of Federal Regulations, 2014 CFR

2014-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Inspector General report. 138.605 Section 138.605 Foreign Relations DEPARTMENT OF STATE MISCELLANEOUS NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 227.605 - Inspector General report.

Code of Federal Regulations, 2014 CFR

2014-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Inspector General report. 227.605 Section 227.605 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 138.605 - Inspector General report.

Code of Federal Regulations, 2013 CFR

2013-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Inspector General report. 138.605 Section 138.605 Foreign Relations DEPARTMENT OF STATE MISCELLANEOUS NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 519.605 - Inspector General report.

Code of Federal Regulations, 2013 CFR

2013-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 2 2013-04-01 2009-04-01 true Inspector General report. 519.605 Section 519.605 Foreign Relations BROADCASTING BOARD OF GOVERNORS NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 227.605 - Inspector General report.

Code of Federal Regulations, 2012 CFR

2012-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Inspector General report. 227.605 Section 227.605 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 138.605 - Inspector General report.

Code of Federal Regulations, 2011 CFR

2011-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Inspector General report. 138.605 Section 138.605 Foreign Relations DEPARTMENT OF STATE MISCELLANEOUS NEW RESTRICTIONS ON LOBBYING Agency Reports...

22 CFR 519.605 - Inspector General report.

Code of Federal Regulations, 2011 CFR

2011-04-01

... the agency submits its annual budget justifications to Congress. (d) The annual report shall include... 22 Foreign Relations 2 2011-04-01 2009-04-01 true Inspector General report. 519.605 Section 519.605 Foreign Relations BROADCASTING BOARD OF GOVERNORS NEW RESTRICTIONS ON LOBBYING Agency Reports...

Can we observe the fronts of the Antarctic Circumpolar Current using GRACE OBP?

NASA Astrophysics Data System (ADS)

Makowski, J.; Chambers, D. P.; Bonin, J. A.

2014-12-01

The Antarctic Circumpolar Current (ACC) and the Southern Ocean remains one of the most undersampled regions of the world's oceans. The ACC is comprised of four major fronts: the Sub-Tropical Front (STF), the Polar Front (PF), the Sub-Antarctic Front (SAF), and the Southern ACC Front (SACCF). These were initially observed individually from repeat hydrographic sections and their approximate locations globally have been quantified using all available temperature data from the World Ocean and Climate Experiment (WOCE). More recent studies based on satellite altimetry have found that the front positions are more dynamic and have shifted south by up to 1° on average since 1993. Using ocean bottom pressure (OBP) data from the current Gravity Recovery and Climate Experiment (GRACE) we have measured integrated transport variability of the ACC south of Australia. However, differentiation of variability of specific fronts has been impossible due to the necessary smoothing required to reduce noise and correlated errors in the measurements. The future GRACE Follow-on (GFO) mission and the post 2020 GRACE-II mission are expected to produce higher resolution gravity fields with a monthly temporal resolution. Here, we study the resolution and error characteristics of GRACE gravity data that would be required to resolve variations in the front locations and transport. To do this, we utilize output from a high-resolution model of the Southern Ocean, hydrology models, and ice sheet surface mass balance models; add various amounts of random and correlated errors that may be expected from GFO and GRACE-II; and quantify requirements needed for future satellite gravity missions to resolve variations along the ACC fronts.

Wind modulation of upwelling at the shelf-break front off Patagonia: Observational evidence

NASA Astrophysics Data System (ADS)

Carranza, M. M.; Gille, S. T.; Piola, A. R.; Charo, M.; Romero, S. I.

2017-03-01

The South-Atlantic Patagonian shelf is the largest chlorophyll-a (Chl-a) hot spot in Southern Ocean color images. While a persistent 1500 km long band of high Chl-a along the shelf-break front (SBF) is indicative of upwelling, the mechanisms that drive it are not entirely known. Along-front wind oscillations can enhance upwelling and provide a nutrient pumping mechanism at shelf-break fronts of western boundary currents. Here we assess wind-induced upwelling at the SBF off Patagonia from daily satellite Chl-a and winds, historical hydrographic observations, cross-shelf Chl-a fluorescence transects from two cruises, and in situ winds and water column structure from a mooring site. Satellite Chl-a composites segregated by along-front wind direction indicate that surface Chl-a is enhanced at the SBF with southerly winds and suppressed with northerly winds. Northerly winds also result in enhanced Chl-a further offshore (˜25-50 km). Synoptic transects as well as mean hydrographic sections segregated by along-front winds show isopycnals tilted upward for southerly winds. Spring observations from the mooring also suggest that southerly winds destratify the water column and northerly winds restratify, in agreement with Ekman transport interacting with the front. Moreover, changes in water column temperature lag along-front wind forcing by 2-4 days. Our results suggest that oscillations in along-front winds, on timescales typical of atmospheric storms (2-10 days), can significantly modulate the upwelling and Chl-a concentrations at the SBF off Patagonia, revealing the importance of wind-induced upwelling for shelf-slope exchange at shelf-break fronts of western boundary currents.

Passive microwave detection of river-plume fronts in the German Bight

NASA Technical Reports Server (NTRS)

Blume, H.-J. C.

1982-01-01

The NASA P-3 aircraft with the L- and S-band radiometer system on board participated in the MARSEN experiments carried out between August 30 and September 23, 1979. Measurements of surface temperature and salinity were concentrated on freshwater outflows of the Rivers Weser and Elbe in the German Bight. Three missions were carried out, on September 19, 22, and 23. The values of salinity are plotted as a function of geographic position, and contour maps of the salinity distribution are generated from the value plots. It is noted that on September 22, during a noon flood-tide, two river-plume salinity fronts were detected when a body of water with higher salinity existed in front of the Weser delta near Bremerhaven generating with the river outflow of lower saline waters a front of delta-S equals 5 per thousand. Another pocket of lower saline waters was found in front of the Elbe delta at Cuxhaven, which in turn set up a strong front of delta-S equals 6 per thousand. The morning low tide of September 23 did not exhibit this extreme condition.

Optimal front light design for reflective displays under different ambient illumination

NASA Astrophysics Data System (ADS)

Wang, Sheng-Po; Chang, Ting-Ting; Li, Chien-Ju; Bai, Yi-Ho; Hu, Kuo-Jui

2011-01-01

The goal of this study is to find out the optimal luminance and color temperature of front light for reflective displays in different ambient illumination by conducting series of psychophysical experiments. A color and brightness tunable front light device with ten LED units was built and been calibrated to present 256 luminance levels and 13 different color temperature at fixed luminance of 200 cd/m2. The experiment results revealed the best luminance and color temperature settings for human observers under different ambient illuminant, which could also assist the e-paper manufacturers to design front light device, and present the best image quality on reflective displays. Furthermore, a similar experiment procedure was conducted by utilizing new flexible e-signage display developed by ITRI and an optimal front light device for the new display panel has been designed and utilized.

Color Confinement, Hadron Dynamics, and Hadron Spectroscopy from Light-Front Holography and Superconformal Algebra

DOE PAGES

Brodsky, Stanley J.

2018-01-01

Tmore » he QCD light-front Hamiltonian equation H L F Ψ = M 2 Ψ derived from quantization at fixed LF time τ = t     +     z / c provides a causal, frame-independent method for computing hadron spectroscopy as well as dynamical observables such as structure functions, transverse momentum distributions, and distribution amplitudes. he QCD Lagrangian with zero quark mass has no explicit mass scale. de Alfaro, Fubini, and Furlan (dAFF) have made an important observation that a mass scale can appear in the equations of motion without affecting the conformal invariance of the action if one adds a term to the Hamiltonian proportional to the dilatation operator or the special conformal operator. If one applies the dAFF procedure to the QCD light-front Hamiltonian, it leads to a color-confining potential κ 4 ζ 2 for mesons, where ζ 2 is the LF radial variable conjugate to the q q ¯ invariant mass squared. he same result, including spin terms, is obtained using light-front holography, the duality between light-front dynamics and A d S 5 , if one modifies the A d S 5 action by the dilaton e κ 2 z 2 in the fifth dimension z . When one generalizes this procedure using superconformal algebra, the resulting light-front eigensolutions provide a unified Regge spectroscopy of meson, baryon, and tetraquarks, including remarkable supersymmetric relations between the masses of mesons and baryons and a universal Regge slope. he pion q q ¯ eigenstate has zero mass at m q = 0 . he superconformal relations also can be extended to heavy-light quark mesons and baryons. his approach also leads to insights into the physics underlying hadronization at the amplitude level. I will also discuss the remarkable features of the Poincaré invariant, causal vacuum defined by light-front quantization and its impact on the interpretation of the cosmological constant. AdS/QCD also predicts the analytic form of the nonperturbative running coupling α s ( Q 2 ) ∝ e - Q 2 / 4 κ 2 . he

Color Confinement, Hadron Dynamics, and Hadron Spectroscopy from Light-Front Holography and Superconformal Algebra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodsky, Stanley J.

Tmore » he QCD light-front Hamiltonian equation H L F Ψ = M 2 Ψ derived from quantization at fixed LF time τ = t     +     z / c provides a causal, frame-independent method for computing hadron spectroscopy as well as dynamical observables such as structure functions, transverse momentum distributions, and distribution amplitudes. he QCD Lagrangian with zero quark mass has no explicit mass scale. de Alfaro, Fubini, and Furlan (dAFF) have made an important observation that a mass scale can appear in the equations of motion without affecting the conformal invariance of the action if one adds a term to the Hamiltonian proportional to the dilatation operator or the special conformal operator. If one applies the dAFF procedure to the QCD light-front Hamiltonian, it leads to a color-confining potential κ 4 ζ 2 for mesons, where ζ 2 is the LF radial variable conjugate to the q q ¯ invariant mass squared. he same result, including spin terms, is obtained using light-front holography, the duality between light-front dynamics and A d S 5 , if one modifies the A d S 5 action by the dilaton e κ 2 z 2 in the fifth dimension z . When one generalizes this procedure using superconformal algebra, the resulting light-front eigensolutions provide a unified Regge spectroscopy of meson, baryon, and tetraquarks, including remarkable supersymmetric relations between the masses of mesons and baryons and a universal Regge slope. he pion q q ¯ eigenstate has zero mass at m q = 0 . he superconformal relations also can be extended to heavy-light quark mesons and baryons. his approach also leads to insights into the physics underlying hadronization at the amplitude level. I will also discuss the remarkable features of the Poincaré invariant, causal vacuum defined by light-front quantization and its impact on the interpretation of the cosmological constant. AdS/QCD also predicts the analytic form of the nonperturbative running coupling α s ( Q 2 ) ∝ e - Q 2 / 4 κ 2 . he

Front fingering and complex dynamics driven by the interaction of buoyancy and diffusive instabilities.

PubMed

D'Hernoncourt, J; Merkin, J H; De Wit, A

2007-09-01

Traveling fronts can become transversally unstable either because of a diffusive instability arising when the key variables diffuse at sufficiently different rates or because of a buoyancy-driven Rayleigh-Taylor mechanism when the density jump across the front is statically unfavorable. The interaction between such diffusive and buoyancy instabilities of fronts is analyzed theoretically for a simple model system. Linear stability analysis and nonlinear simulations show that their interplay changes considerably the stability properties with regard to the pure Rayleigh-Taylor or diffusive instabilities of fronts. In particular, an instability scenario can arise which triggers convection around statically stable fronts as a result of differential diffusion. Moreover, spatiotemporal chaos can be observed when both buoyancy and diffusive effects cooperate to destabilize the front. Experimental conditions to test our predictions are suggested.

Long, Strong Eastern U.S. Cold Front Brings Changes

NASA Image and Video Library

2013-12-23

A long, strong, cold front draped over the eastern U.S. is marking a stark change from record-warmth to very cold temperatures. This NOAA GOES-East satellite image from December 23 at 1515 UTC/10:15 a.m. EST shows a powerful cold front covering the U.S. East Coast and stretching into the central and southwestern Gulf of Mexico. According to the National Weather Service, that front is bringing rain and embedded thunderstorms over the Mid-Atlantic and Southeastern U.S. The same system is bringing lingering wintry precipitation to northern New England and upstate New York. Behind the cold front, much colder and dry Canadian air will filter in under high pressure and bring sunshine over the eastern U.S. in time for Christmas. The image was created by the NASA GOES Project at NASA's Goddard Space Flight Center, Greenbelt, Md. Rob Gutro NASA Goddard Space Flight Center NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Slow Progress in Dune (Left Front Wheel)

NASA Technical Reports Server (NTRS)

2005-01-01

The left front wheel of NASA's Mars Exploration Rover Opportunity makes slow but steady progress through soft dune material in this movie clip of frames taken by the rover's front hazard identification camera over a period of several days. The sequence starts on Opportunity's 460th martian day, or sol (May 10, 2005) and ends 11 days later. In eight drives during that period, Opportunity advanced a total of 26 centimeters (10 inches) while spinning its wheels enough to have driven 46 meters (151 feet) if there were no slippage. The motion appears to speed up near the end of the clip, but that is an artifact of individual frames being taken less frequently.

The CF6 jet engine performance improvement: New front mount

NASA Technical Reports Server (NTRS)

Fasching, W. A.

1979-01-01

The New Front Mount was evaluated in component tests including stress, deflection/distortion and fatigue tests. The test results demonstrated a performance improvement of 0.1% in cruise sfc, 16% in compressor stall margin and 10% in compressor stator angle margin. The New Front Mount hardware successfully completed 35,000 simulated flight cycles endurance testing.

The DIRC front-end electronics chain for BaBar

NASA Astrophysics Data System (ADS)

Bailly, P.; Beigbeder, C.; Bernier, R.; Breton, D.; Bonneaud, G.; Caceres, T.; Chase, R.; Chauveau, J.; Del Buono, L.; Dohou, F.; Ducorps, A.; Gastaldi, F.; Genat, J. F.; Hrisoho, A.; Imbert, P.; Lebbolo, H.; Matricon, P.; Oxoby, G.; Renard, C.; Roos, L.; Sen, S.; Thiebaux, C.; Truong, K.; Tocut, V.; Vasileiadis, G.; Va'Vra, J.; Verderi, M.; Warner, D.; Wilson, R. J.; Wormser, G.; Zhang, B.; Zomer, F.

2000-12-01

Recent results from the Front-End electronics of the Detector of Internally Reflected Cerenkov light (DIRC) for the BaBar experiment at SLAC (Stanford, USA) are presented. It measures to better than 1 ns the arrival time of Cerenkov photoelectrons detected in a 11000 phototubes array and their amplitude spectra. It mainly comprises 64-channel DIRC Front-End Boards (DFB) equipped with eight full-custom analog chips performing zero-cross discrimination with 2 mV threshold and pulse shaping, four full-custom digital time to digital chips (TDC) for timing measurements with 500 ps binning and a readout logic selecting hits in the trigger window, and DIRC Crate Controller cards (DCC) serializing the data collected front up to 16 DFBs onto a 1.2 Gb/s optical link. Extensive test results of the pre-production chips are presented, as well as system tests.

Bifurcating fronts for the Taylor-Couette problem in infinite cylinders

NASA Astrophysics Data System (ADS)

Hărăguş-Courcelle, M.; Schneider, G.

We show the existence of bifurcating fronts for the weakly unstable Taylor-Couette problem in an infinite cylinder. These fronts connect a stationary bifurcating pattern, here the Taylor vortices, with the trivial ground state, here the Couette flow. In order to show the existence result we improve a method which was already used in establishing the existence of bifurcating fronts for the Swift-Hohenberg equation by Collet and Eckmann, 1986, and by Eckmann and Wayne, 1991. The existence proof is based on spatial dynamics and center manifold theory. One of the difficulties in applying center manifold theory comes from an infinite number of eigenvalues on the imaginary axis for vanishing bifurcation parameter. But nevertheless, a finite dimensional reduction is possible, since the eigenvalues leave the imaginary axis with different velocities, if the bifurcation parameter is increased. In contrast to previous work we have to use normalform methods and a non-standard cut-off function to obtain a center manifold which is large enough to contain the bifurcating fronts.

Extreme weather caused by concurrent cyclone, front and thunderstorm occurrences

PubMed Central

Dowdy, Andrew J.; Catto, Jennifer L.

2017-01-01

Phenomena such as cyclones, fronts and thunderstorms can cause extreme weather in various regions throughout the world. Although these phenomena have been examined in numerous studies, they have not all been systematically examined in combination with each other, including in relation to extreme precipitation and extreme winds throughout the world. Consequently, the combined influence of these phenomena represents a substantial gap in the current understanding of the causes of extreme weather events. Here we present a systematic analysis of cyclones, fronts and thunderstorms in combination with each other, as represented by seven different types of storm combinations. Our results highlight the storm combinations that most frequently cause extreme weather in various regions of the world. The highest risk of extreme precipitation and extreme wind speeds is found to be associated with a triple storm type characterized by concurrent cyclone, front and thunderstorm occurrences. Our findings reveal new insight on the relationships between cyclones, fronts and thunderstorms and clearly demonstrate the importance of concurrent phenomena in causing extreme weather. PMID:28074909

Multi-Material Front Contact for 19% Thin Film Solar Cells.

PubMed

van Deelen, Joop; Tezsevin, Yasemin; Barink, Marco

2016-02-06

The trade-off between transmittance and conductivity of the front contact material poses a bottleneck for thin film solar panels. Normally, the front contact material is a metal oxide and the optimal cell configuration and panel efficiency were determined for various band gap materials, representing Cu(In,Ga)Se₂ (CIGS), CdTe and high band gap perovskites. Supplementing the metal oxide with a metallic copper grid improves the performance of the front contact and aims to increase the efficiency. Various front contact designs with and without a metallic finger grid were calculated with a variation of the transparent conductive oxide (TCO) sheet resistance, scribing area, cell length, and finger dimensions. In addition, the contact resistance and illumination power were also assessed and the optimal thin film solar panel design was determined. Adding a metallic finger grid on a TCO gives a higher solar cell efficiency and this also enables longer cell lengths. However, contact resistance between the metal and the TCO material can reduce the efficiency benefit somewhat.

Ice Front at Venable Ice Shelf

NASA Image and Video Library

2013-06-13

This photo, taken onboard the Chilean Navy P3 aircraft, shows the ice front of Venable Ice Shelf, West Antarctica, in October 2008. It is an example of a small-size ice shelf that is a large melt water producer.

34 CFR 82.605 - Inspector General report.

Code of Federal Regulations, 2013 CFR

2013-07-01

... its annual budget justifications to Congress. (d) The annual report shall include the following: All... 34 Education 1 2013-07-01 2013-07-01 false Inspector General report. 82.605 Section 82.605 Education Office of the Secretary, Department of Education NEW RESTRICTIONS ON LOBBYING Agency Reports § 82...

20 CFR 438.605 - Inspector General report.

Code of Federal Regulations, 2012 CFR

2012-04-01

... annual report will be submitted at the same time we submit our annual budget justification to Congress... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Inspector General report. 438.605 Section 438.605 Employees' Benefits SOCIAL SECURITY ADMINISTRATION RESTRICTIONS ON LOBBYING Agency Reports § 438...

45 CFR 1158.605 - Inspector General report.

Code of Federal Regulations, 2012 CFR

2012-10-01

... its annual budget justifications to Congress. (d) The annual report shall include the following: All... 45 Public Welfare 3 2012-10-01 2012-10-01 false Inspector General report. 1158.605 Section 1158... AND THE HUMANITIES NATIONAL ENDOWMENT FOR THE ARTS NEW RESTRICTIONS ON LOBBYING Agency Reports § 1158...