WorldWideScience

Sample records for density profile shape

  1. Plasma Shape and Current Density Profile Control in Advanced Tokamak Operating Scenarios

    Science.gov (United States)

    Shi, Wenyu

    The need for new sources of energy is expected to become a critical problem within the next few decades. Nuclear fusion has sufficient energy density to potentially supply the world population with its increasing energy demands. The tokamak is a magnetic confinement device used to achieve controlled fusion reactions. Experimental fusion technology has now reached a level where tokamaks are able to produce about as much energy as is expended in heating the fusion fuel. The next step towards the realization of a nuclear fusion tokamak power plant is ITER, which will be capable of exploring advanced tokamak (AT) modes, characterized by a high fusion gain and plasma stability. The extreme requirements of the advanced modes motivates researchers to improve the modeling of the plasma response as well as the design of feedback controllers. This dissertation focuses on several magnetic and kinetic control problems, including the plasma current, position and shape control, and data-driven and first-principles-driven modeling and control of plasma current density profile and the normalized plasma pressure ratio betaN. The plasma is confined within the vacuum vessel by an external electromagnetic field, produced primarily by toroidal and poloidal field coils. The outermost closed plasma surface or plasma boundary is referred to as the shape of the plasma. A central characteristic of AT plasma regimes is an extreme elongated shape. The equilibrium among the electromagnetic forces acting on an elongated plasma is unstable. Moreover, the tokamak performance is improved if the plasma is located in close proximity to the torus wall, which guarantees an efficient use of available volume. As a consequence, feedback control of the plasma position and shape is necessary. In this dissertation, an Hinfinity-based, multi-input-multi-output (MIMO) controller for the National Spherical Torus Experiment (NSTX) is developed, which is used to control the plasma position, shape, and X

  2. The variation of rotation curve shapes as a signature of the effects of baryons on dark matter density profiles

    Science.gov (United States)

    Brook, Chris B.

    2015-12-01

    Rotation curves of galaxies show a wide range of shapes, which can be paramaterized as scatter in Vrot(1 kpc)/Vmax , i.e. the ratio of the rotation velocity measured at 1 kpc and the maximum measured rotation velocity. We examine whether the observed scatter can be accounted for by combining scatters in disc scalelengths, the concentration-halo mass relation, and the M⋆-Mhalo relation. We use these scatters to create model galaxy populations; when housed within dark matter haloes that have universal, Navarro, Frenk & White density profiles, the model does not match the lowest observed values of Vrot(1 kpc)/Vmax and has too little scatter in Vrot(1 kpc)/Vmax compared to observations. By contrast, a model using a mass-dependent dark matter profile, where the inner slope is determined by the ratio of M⋆/Mhalo, produces galaxies with low values of Vrot(1 kpc)/Vmax and a much larger scatter, both in agreement with observation. We conclude that the large observed scatter in Vrot(1 kpc)/Vmax favours density profiles that are significantly affected by baryonic processes. Alternative dark matter core formation models such as self-interacting dark matter may also account for the observed variation in rotation curve shapes, but these observations may provide important constraints in terms of core sizes, and whether they vary with halo mass and/or merger history.

  3. Density profiles of LCDM clusters

    CERN Document Server

    Tasitsiomi, A; Gottlöber, S; Klypin, A A; Tasitsiomi, Argyro; Kravtsov, Andrey V.; Gottloeber, Stefan; Klypin, Anatoly A.

    2004-01-01

    We analyze the mass accretion histories (MAHs) and density profiles of cluster- size halos with virial masses of 0.6-2.5x10^14/h Msun in a flat LCDM cosmology. In agreement with previous studies,we find that the concentration of the density distribution is tightly correlated with the halo's MAH and its formation redshift.During the period of fast mass growth the concentration remains approximately constant and low c_v~3-4,while during the slow accretion stages it increases with decreasing redshift as c_v~(1+z)^-1.We consider fits of three widely discussed analytic density profiles to the simulated clusters focusing on the most relaxed inner regions.We find that there is no unique best fit analytic profile for all the systems.If,however,a cluster is best fit by a particular analytic profile at z=0,the same is usually true at earlier epochs out to z~1-2.The local logarithmic slope of the density profiles at 3% of the virial radius ranges from -1.2 to -2.0,a remarkable diversity for the relatively narrow mass ra...

  4. Density-Based 3D Shape Descriptors

    Directory of Open Access Journals (Sweden)

    Schmitt Francis

    2007-01-01

    Full Text Available We propose a novel probabilistic framework for the extraction of density-based 3D shape descriptors using kernel density estimation. Our descriptors are derived from the probability density functions (pdf of local surface features characterizing the 3D object geometry. Assuming that the shape of the 3D object is represented as a mesh consisting of triangles with arbitrary size and shape, we provide efficient means to approximate the moments of geometric features on a triangle basis. Our framework produces a number of 3D shape descriptors that prove to be quite discriminative in retrieval applications. We test our descriptors and compare them with several other histogram-based methods on two 3D model databases, Princeton Shape Benchmark and Sculpteur, which are fundamentally different in semantic content and mesh quality. Experimental results show that our methodology not only improves the performance of existing descriptors, but also provides a rigorous framework to advance and to test new ones.

  5. Isogeometric shape optimization of magnetic density separators

    OpenAIRE

    2013-01-01

    Purpose: The waste recycling industry increasingly relies on magnetic density separators. These devices generate an upward magnetic force in ferro-fluids allowing to separate the immersed particles according to their mass density. Recently a new separator design that significantly reduces the required amount of permanent magnet material has been proposed. The purpose of this paper is to alleviate the undesired end-effects in this design by altering the shape of the ferromagnetic covers of the...

  6. Laser beam shaping profiles and propagation.

    Science.gov (United States)

    Shealy, David L; Hoffnagle, John A

    2006-07-20

    We consider four families of functions--the super-Gaussian, flattened Gaussian, Fermi-Dirac, and super-Lorentzian--that have been used to describe flattened irradiance profiles. We determine the shape and width parameters of the different distributions, when each flattened profile has the same radius and slope of the irradiance at its half-height point, and then we evaluate the implicit functional relationship between the shape and width parameters for matched profiles, which provides a quantitative way to compare profiles described by different families of functions. We conclude from an analysis of each profile with matched parameters using Kirchhoff-Fresnel diffraction theory and M2 analysis that the diffraction patterns as they propagate differ by small amounts, which may not be distinguished experimentally. Thus, beam shaping optics is designed to produce either of these four flattened output irradiance distributions with matched parameters will yield similar irradiance distributions as the beam propagates.

  7. Universal density profile for cosmic voids.

    Science.gov (United States)

    Hamaus, Nico; Sutter, P M; Wandelt, Benjamin D

    2014-06-27

    We present a simple empirical function for the average density profile of cosmic voids, identified via the watershed technique in ΛCDM N-body simulations. This function is universal across void size and redshift, accurately describing a large radial range of scales around void centers with only two free parameters. In analogy to halo density profiles, these parameters describe the scale radius and the central density of voids. While we initially start with a more general four-parameter model, we find two of its parameters to be redundant, as they follow linear trends with the scale radius in two distinct regimes of the void sample, separated by its compensation scale. Assuming linear theory, we derive an analytic formula for the velocity profile of voids and find an excellent agreement with the numerical data as well. In our companion paper [Sutter et al., arXiv:1309.5087 [Mon. Not. R. Astron. Soc. (to be published)

  8. On the Density profile slope of Clusters of Galaxies

    CERN Document Server

    Del Popolo, A

    2012-01-01

    The present paper extends to clusters of galaxies the study of Del Popolo (2012), concerning how the baryon-dark matter (DM) interplay shapes the density profile of dwarf galaxies. Cluster density profiles are determined taking into account dynamical friction, random and ordered angular momentum and the response of dark matter halos to condensation of baryons. We find that halos containing only DM are characterized by Einasto's profiles, and that the profile flattens with increasing content of baryons, and increasing values of random angular momentum. The analytical results obtained in the first part of the paper were applied to well studied clusters whose inner profiles have slopes flatter than NFW predictions (A611, A383) or are characterized by profiles in agreement with the NFW model (MACS J1423.8+2404, RXJ1133). By using independently-measured baryonic fraction, a typical spin parameter value $\\lambda \\simeq 0.03$, and adjusting the random angular momentum, we re-obtain the mass and density profiles of t...

  9. Isogeometric shape optimization of magnetic density separators

    NARCIS (Netherlands)

    Dang Manh, N.; Evgrafov, A.; Gravesen, J.; Lahaye, D.

    2013-01-01

    Purpose: The waste recycling industry increasingly relies on magnetic density separators. These devices generate an upward magnetic force in ferro-fluids allowing to separate the immersed particles according to their mass density. Recently a new separator design that significantly reduces the requir

  10. Iso-geometric shape optimization of magnetic density separators

    DEFF Research Database (Denmark)

    Dang Manh, Nguyen; Evgrafov, Anton; Gravesen, Jens

    2014-01-01

    Purpose The waste recycling industry increasingly relies on magnetic density separators. These devices generate an upward magnetic force in ferro-fluids allowing to separate the immersed particles according to their mass density. Recently, a new separator design has been proposed that significantly...... is obtained at the cost of a pole cover shape that differs per pole. This limitation has negligible impact on the manufacturing of the separator. The new pole cover shapes therefore lead to improved performance of the density separation. Practical implications Due to the larger uniformity the generated field......, these shapes should enable larger amounts of waste to be processed than the previous design. Originality/value This paper treats the shapes optimization of magnetic density separators systematically and presents new shapes for the ferromagnetic poles covers....

  11. Electon density profiles of the topside ionosphere

    Directory of Open Access Journals (Sweden)

    D. Bilitza

    2002-06-01

    Full Text Available The existing uncertainties about the electron density profiles in the topside ionosphere, i.e., in the height region from h m F 2 to ~ 2000 km, require the search for new data sources. The ISIS and Alouette topside sounder satellites from the sixties to the eighties recorded millions of ionograms but most were not analyzed in terms of electron density profiles. In recent years an effort started to digitize the analog recordings to prepare the ionograms for computerized analysis. As of November 2001 about 350 000 ionograms have been digitized from the original 7-track analog tapes. These data are available in binary and CDF format from the anonymous ftp site of the National Space Science Data Center. A search site and browse capabilities on CDAWeb assist the scientific usage of these data. All information and access links can be found at http://nssdc.gsfc.nasa.gov/space/isis/isis-status. html. This paper describes the ISIS data restoration effort and shows how the digital ionograms are automatically processed into electron density profiles from satellite orbit altitude (1400 km for ISIS-2 down to the F peak. Because of the large volume of data an automated processing algorithm is imperative. The TOPside Ionogram Scaler with True height algorithm TOPIST software developed for this task is successfully scaling ~ 70% of the ionograms. An «editing process» is available to manually scale the more difficult ionograms. The automated processing of the digitized ISIS ionograms is now underway, producing a much-needed database of topside electron density profiles for ionospheric modeling covering more than one solar cycle.

  12. Nuclear shape transitions, level density, and underlying interactions

    CERN Document Server

    Karampagia, S

    2016-01-01

    The configuration interaction approach to nuclear structure uses the effective Hamiltonian in a finite orbital space. The various parts of this Hamiltonian and their interplay are responsible for specific features of physics including the shape of the mean field and level density. This interrelation is not sufficiently understood. We intend to study phase transitions between spherical and deformed shapes driven by different parts of the nuclear Hamiltonian and to establish the presence of the collective enhancement of the nuclear level density by varying the shell-model matrix elements. Varying the interaction matrix elements we define, for nuclei in the sd and pf shells, the sectors with spherical and deformed shapes. Using the moments method that does not require the full diagonalization we relate the shape transitions with the corresponding level density. Enhancement of the level density in the low-energy part of the spectrum is observed in clear correlation with a deformation phase transition induced main...

  13. DSP: a protein shape string and its profile prediction server.

    Science.gov (United States)

    Sun, Jiangming; Tang, Shengnan; Xiong, Wenwei; Cong, Peisheng; Li, Tonghua

    2012-07-01

    Many studies have demonstrated that shape string is an extremely important structure representation, since it is more complete than the classical secondary structure. The shape string provides detailed information also in the regions denoted random coil. But few services are provided for systematic analysis of protein shape string. To fill this gap, we have developed an accurate shape string predictor based on two innovative technologies: a knowledge-driven sequence alignment and a sequence shape string profile method. The performance on blind test data demonstrates that the proposed method can be used for accurate prediction of protein shape string. The DSP server provides both predicted shape string and sequence shape string profile for each query sequence. Using this information, the users can compare protein structure or display protein evolution in shape string space. The DSP server is available at both http://cheminfo.tongji.edu.cn/dsp/ and its main mirror http://chemcenter.tongji.edu.cn/dsp/.

  14. ?Linear Gas Jet with Tailored Density Profile"

    Energy Technology Data Exchange (ETDEWEB)

    KRISHNAN, Mahadevan

    2012-12-10

    Supersonic, highly collimated gas jets and gas-filled capillary discharge waveguides are two primary targets of choice for Laser Plasma Accelerators (LPA) . Present gas jets have lengths of only 2-4 mm at densities of 1-4E19 cm-3, sufficient for self trapping and electron acceleration to energies up to ~150 MeV. Capillary structures 3 cm long have been used to accelerate beams up to 1 GeV. Capillary discharges used in LPAs serve to guide the pump laser and optimize the energy gain. A wall-stabilized capillary discharge provides a transverse profile across the channel that helps guide the laser and combat diffraction. Gas injection via a fast nozzle at one end provides some longitudinal density control, to improve the coupling. Gas jets with uniform or controlled density profiles may be used to control electron bunch injection and are being integrated into capillary experiments to add tuning of density. The gas jet for electron injection has not yet been optimized. Our Ph-I results have provided the LPA community with an alternative path to realizing a 2-3GeV electron bunch using just a gas jet. For example, our slit/blade combination gives a 15-20mm long acceleration path with tunable density profile, serving as an alternative to a 20-mm long capillary discharge with gas injection at one end. In Ph-II, we will extend these results to longer nozzles, to see whether we can synthesize 30 or 40-mm long plasma channels for LPAs.

  15. On the physical origin of dark matter density profiles

    CERN Document Server

    Ascasibar, Y; Gottlöber, S; Müller, V

    2003-01-01

    The radial mass distribution of dark matter haloes is investigated within the framework of the spherical infall model. We present a new formulation of spherical collapse including non-radial motions, and compare the analytical profiles with a set of high-resolution N-body simulations ranging from galactic to cluster scales. We argue that the dark matter density profile is entirely determined by the initial conditions, which are described by only two parameters: the height of the primordial peak and the smoothing scale. These are physically meaningful quantities in our model, related to the mass and formation time of the halo. Angular momentum is dominated by velocity dispersion, and it is responsible for the shape of the density profile near the centre. The phase-space density of our simulated haloes is well described by a power-law profile, rho/sigma^3 = 10^{1.46\\pm0.04} (rho_c/Vvir^3) (r/Rvir)^{-1.90\\pm0.05}. Setting the eccentricity of particle orbits according to the numerical results, our model is able t...

  16. Density profile of pyrolitic lower mantle

    Science.gov (United States)

    Sinmyo, R.; Hirose, K.; Ohishi, Y.

    2010-12-01

    Density profile of pyrolite at lower mantle high-pressure (P) and -temperature (T) conditions was investigated by using laser-heated diamond-anvil cell up to 117 GPa and 2800 K. The density was determined from chemical composition and unit-cell volume of each constituent mineral (MgSiO3-rich perovskite, ferropericlase and CaSiO3-rich perovskite). The chemical compositions of coexisting phases were analyzed by transmission electron microscope, and their volumes were obtained by in-situ X-ray diffraction measurements. To avoid extensive chemical segregation during laser-heating, sample was coated by gold that worked as a laser absorber (Sinmyo and Hirose 2010 PEPI). Results of chemical analyses show that Mg-Fe (total Fe) partitioning coefficient between MgSiO3-rich perovskite and ferropericlase [K* = (Fe*/Mg)Pv/(Fe*/Mg)Fp] is about 0.6, slightly higher than the value previously reported in the pyrolitic bulk composition (Murakami et al. 2005 GRL). The lower K* value in the previous study may be attributed to the chemical heterogeneity in the sample induced by strong temperature gradient during laser heating. The calculated density profile of pyrolite is indeed in good agreement with the PREM model within experimental errors, in contrast with the mismatch reported by the previous study (Ricolleau et al. 2009 GRL). Our results support the lower mantle has pyrolitic bulk composition, and thus it is not necessary to suppose the chemically stratification in the lower mantle.

  17. Creating steep density profile with a separatrix

    CERN Document Server

    Ogawa, Shun; Vasiliev, Alexei; Garbet, Xavier

    2016-01-01

    The mesoscopic properties of a plasma in a cylindrical magnetic field are investigated from the view point of test-particle dynamics. When the system has enough time and spatial symmetries, a Hamiltonian of a test particle is completely integrable and can be reduced to a single degree of freedom Hamiltonian for each initial state. The reduced Hamiltonian sometimes has an unstable fixed point (saddle point) and a separatrix. Using a maximum entropy principle we compute dynamically compatible equilibrium states of the one particle density function of these systems and discuss how the unstable fixed points affect the density profile or a local pressure gradient, and are able to create a so called internal transport barrier.

  18. Galactic cannibalism and CDM density profiles

    CERN Document Server

    Nipoti, C; Ciotti, L; Stiavelli, M

    2004-01-01

    Using N-body simulations we show that the process of formation of the brightest cluster galaxy through dissipationless galactic cannibalism can affect the inner cluster dark matter density profile. In particular, we use as realistic test case the dynamical evolution of the galaxy cluster C0337-2522 at redshift z=0.59, hosting in its centre a group of five elliptical galaxies which are likely to be the progenitor of a central giant elliptical. After the formation of the brightest cluster galaxy, the inner cluster dark matter density profile is significantly flatter (logarithmic slope 0.48

  19. Convergence and scatter of cluster density profiles

    CERN Document Server

    Diemand, J; Stadel, J; Diemand, Juerg; Moore, Ben; Stadel, Joachim

    2004-01-01

    We present new results from a series of $\\Lambda$CDM simulations of cluster mass halos resolved with high force and mass resolution. These results are compared with recently published simulations from groups using various codes including PKDGRAV, ART, TPM, GRAPE and GADGET. Careful resolution tests show that with 25 million particles within the high resolution region we can resolve to about 0.3\\% of the virial radius and that convergence in radius is proportional to the mean interparticle separation. The density profiles of 28 high resolution clusters obtained with the different codes and from different initial conditions agree very well. The average logarithmic slope at one percent of the virial radius is $\\gamma = 1.29$ with a scatter of $\\pm 0.16$ at all radii. Over the entire resolved regions the density profiles are well fitted by a smooth function that asymptotes to a central cusp $\\rho \\propto r^{-\\gamma}$, where we find $\\gamma=1.16\\pm 0.14$ from the mean of the fits to our six highest resolution clus...

  20. Iso-geometric shape optimization of magnetic density separators

    OpenAIRE

    2014-01-01

    PurposeThe waste recycling industry increasingly relies on magnetic density separators. These devices generate an upward magnetic force in ferro-fluids allowing to separate the immersed particles according to their mass density. Recently, a new separator design has been proposed that significantly reduces the required amount of permanent magnet material. The purpose of this paper is to alleviate the undesired end-effects in this design by altering the shape of the ferromagnetic covers of the ...

  1. Comparison of nest shapes and densities of two sympatric species ...

    African Journals Online (AJOL)

    Comparison of nest shapes and densities of two sympatric species of ... there are significant, though small, differences in height, diameter, number of caps, surface ... the addition of a first cap decreases the volume/surface ratio but a second or ...

  2. Shape transition of state density for bosonic systems

    Indian Academy of Sciences (India)

    Harshal N Deota; N D Chavda; V Potbhare

    2013-12-01

    For a finite boson system, the ensemble-averaged state density has been computed with respect to the body interaction rank . The shape of such a state density changes from Gaussian to semicircle as the body rank of the interaction increases. This state density is expressed as a linear superposition of Gaussian and semicircular states. The nearest-neighbour spacing distribution (NNSD), which is one of the most important spectral properties of a system, is studied. The NNSDs are rather independent of body rank and show a Wigner distribution throughout.

  3. On the universality of density profiles

    CERN Document Server

    Del Popolo, A

    2010-01-01

    We use the secondary infall model described in Del Popolo (2009), which takes into account the effect of dynamical friction, ordered and random angular momentum, baryons adiabatic contraction and dark matter baryons interplay, to study how in- ner slopes of relaxed LCDM dark matter (DM) halos with and without baryons (baryons+DM, and pure DM) depend on redshift and on halo mass. We apply the quoted method to structures on galactic scales and clusters of galaxies scales. We find that the inner logarithmic density slope, of dark matter halos with baryons has a significant dependence on halo mass and redshift with slopes ranging from 0 for dwarf galaxies to 0.4 for objects of M = 10^13M_solar and 0.94 for M = 10^15M_solar clusters of galaxies. Structures slopes increase with increasing redshift and this trend reduces going from galaxies to clusters. In the case of density profiles constituted just of dark matter the mass and redshift dependence of slope is very slight. In this last case, we used the Merrit et al...

  4. Calculating electron momentum densities and Compton profiles using the linear tetrahedron method.

    Science.gov (United States)

    Ernsting, D; Billington, D; Haynes, T D; Millichamp, T E; Taylor, J W; Duffy, J A; Giblin, S R; Dewhurst, J K; Dugdale, S B

    2014-12-10

    A method for computing electron momentum densities and Compton profiles from ab initio calculations is presented. Reciprocal space is divided into optimally-shaped tetrahedra for interpolation, and the linear tetrahedron method is used to obtain the momentum density and its projections such as Compton profiles. Results are presented and evaluated against experimental data for Be, Cu, Ni, Fe3Pt, and YBa2Cu4O8, demonstrating the accuracy of our method in a wide variety of crystal structures.

  5. Iso-geometric shape optimization of magnetic density separators

    DEFF Research Database (Denmark)

    Dang Manh, Nguyen; Evgrafov, Anton; Gravesen, Jens;

    2014-01-01

    Purpose The waste recycling industry increasingly relies on magnetic density separators. These devices generate an upward magnetic force in ferro-fluids allowing to separate the immersed particles according to their mass density. Recently, a new separator design has been proposed that significantly...... covers with B-splines and defines a cost functional that measures the non-uniformity of the magnetic field in an area above the poles. The authors apply an iso-geometric shape optimization procedure, which allows us to accurately represent, analyze and optimize the geometry using only a few design...... variables. The design problem is regularized by imposing constraints that enforce the convexity of the pole cover shapes and is solved by a non-linear optimization procedure. The paper validates the implementation of the algorithm using a simplified variant of the design problem with a known analytical...

  6. Interactive design of probability density functions for shape grammars

    KAUST Repository

    Dang, Minh

    2015-11-02

    A shape grammar defines a procedural shape space containing a variety of models of the same class, e.g. buildings, trees, furniture, airplanes, bikes, etc. We present a framework that enables a user to interactively design a probability density function (pdf) over such a shape space and to sample models according to the designed pdf. First, we propose a user interface that enables a user to quickly provide preference scores for selected shapes and suggest sampling strategies to decide which models to present to the user to evaluate. Second, we propose a novel kernel function to encode the similarity between two procedural models. Third, we propose a framework to interpolate user preference scores by combining multiple techniques: function factorization, Gaussian process regression, autorelevance detection, and l1 regularization. Fourth, we modify the original grammars to generate models with a pdf proportional to the user preference scores. Finally, we provide evaluations of our user interface and framework parameters and a comparison to other exploratory modeling techniques using modeling tasks in five example shape spaces: furniture, low-rise buildings, skyscrapers, airplanes, and vegetation.

  7. Reaching Higher Densities for Laboratory White Dwarf Photospheres to Measure Spectroscopic Line Profiles

    CERN Document Server

    Falcon, Ross E; Gomez, T A; Schaeuble, M; Nagayama, T; Montgomery, M H; Winget, D E; Rochau, G A

    2016-01-01

    As part of our laboratory investigation of the theoretical line profiles used in white dwarf atmosphere models, we extend the electron-density ($n_{\\rm e}$) range measured by our experiments to higher densities (up to $n_{e}\\sim80\\times10^{16}$ cm$^{-3}$). Whereas inferred parameters using the hydrogen-$\\beta$ spectral line agree among different line-shape models for $n_{\\rm e}\\lesssim30\\times10^{16}$ cm$^{-3}$, we now see divergence between models. These are densities beyond the range previously benchmarked in the laboratory, meaning theoretical profiles in this regime have not been fully validated. Experimentally exploring these higher densities enables us to test and constrain different line-profile models, as the differences in their relative H-Balmer line shapes are more pronounced at such conditions. These experiments also aid in our study of occupation probabilities because we can measure these from relative line strengths.

  8. Electron density profiles in the background of LF absorption during Forbush-decrease and PSE

    Science.gov (United States)

    Satori, G.

    1989-01-01

    Based on the simulation of different Forbush decrease and particle precipitation effects in the D region, electron density profiles in the mid-latitudes the ionospheric absorption of low frequency (LF) radio waves was determined. The absorption variations at different frequenceis are strongly affected by the shape of the electron density profile. A structure appears which sometimes resembles the letter S (in a sloping form). Both the height (around 70 to 72 km) and the depth of the local minimum in the electron density contribute to the computed absorption changes of various degree at different frequencies. In this way several observed special absorption events can be interpreted.

  9. NOTE: The Shape of Triton from Limb Profiles

    Science.gov (United States)

    Thomas, P. C.

    2000-12-01

    Limb profiles from Voyager 2 images of Triton show it to be an ellipsoid of axes 1354.6, 1352.8, and 1352.4 km (±0.9 km). Topography on the limbs suggests no large provinces such as "continents" with relief over a kilometer. The shape solution is not accurate enough to constrain Triton's moments of inertia. The apparently relaxed shape is consistent with the youthful geologic features and supports interpretations that atmospheric distortion suggested by occultation data is due to atmospheric phenomena rather than physical body distortions.

  10. Scaling Evolution of Universal Dark-Matter Halo Density Profiles

    CERN Document Server

    Raig, A; Salvador-Solé, E

    1998-01-01

    Dark-matter halos show a universal density profile with a scaling such that less massive systems are typically denser. This mass-density relation is well described by a proportionality between the characteristic density of halos and the mean cosmic density at halo formation time. It has recently been shown that this proportionality could be the result of the following simple evolutionary picture. Halos form in major mergers with essentially the same, cosmogony-dependent, dimensionless profile, and then grow inside-outside, as a consequence of accretion. Here we verify the consistency of this picture and show that it predicts the correct zero point of the mass-density relation.

  11. The effect of shockwave profile shape on dynamic brittle failure

    Directory of Open Access Journals (Sweden)

    Gray G.T.

    2012-08-01

    Full Text Available The role of shock wave loading profile is investigated for the failure processes in a brittle material. The dynamic damage response of ductile metals has been demonstrated to be critically dependent on the shockwave profile and the stress-state of the shock. Changing from a square to triangular (Taylor profile with an identical peak compressive stress has been reported to increase the “spall strength” by over a factor of two and suppress damage mechanisms. The spall strength of tungsten heavy alloy (WHA based on plate impact square-wave loading has been extensively reported in the literature. Here a triangular wave loading profile is achieved with a composite flyer plate of graded density in contrast to the square-wave loading. Counter to the strong dependence in wave profile in ductile metals, for WHA, both square and triangle wave profiles the failure is by brittle cleavage fracture with additional energy dissipation through crack branching in the more brittle tungsten particles, largely indistinguishable between wave profiles. The time for crack nucleation is negligible compared to the duration of the experiment and the crack propagation rate is limited to the sound speed as defined by the shock velocity.

  12. Void alignment and density profile applied to measuring cosmological parameters

    CERN Document Server

    Dai, De-Chang

    2015-01-01

    We study the orientation and density profiles of the cosmological voids with SDSS10 data. Using voids to test Alcock-Paczynski effect has been proposed and tested in both simulations and actual SDSS data. Previous observations imply that there exist an empirical stretching factor which plays an important role in the voids' orientation. Simulations indicate that this empirical stretching factor is caused by the void galaxies' peculiar velocities. Recently Hamaus et al. found that voids' density profiles are universal and their average velocities satisfy linear theory very well. In this article we first confirm that the stretching effect exists using independent analysis. We then apply the universal density profile to measure the cosmological parameters. We find that the void density profile can be a tool to measure the cosmological parameters.

  13. On the size, shape, and density of dwarf planet Makemake

    CERN Document Server

    Brown, M E

    2013-01-01

    A recent stellar occultation by dwarf planet Makemake provided an excellent opportunity to measure the size and shape of one of the largest objects in the Kuiper belt. The analysis of these results provided what were reported to be precise measurements of the lengths of the projected axes, the albedo, and even the density of Makemake, but these results were, in part, derived from qualitative arguments. We reanalyzed the occultation timing data using a quantitative statistical description, and, in general, find the previously reported results on the shape of Makemake to be unjustified. In our solution, in which we use our inference from photometric data that Makemake is being viewed nearly pole-on, we find a 1 sigma upper limit to the projected elongation of Makemake of 1.02, with measured equatorial diameter of 1434 +/- 14 km and a projected polar diameter of 1422 +/- 14 km, yielding an albedo of 0.81+0.01/-0.02$. If we remove the external constraint on the pole position of Makemake, we find instead a 1 sigma...

  14. Electron Density Profile Data Contains Virtual Height/Frequency Pairs from a Profile or Profiles (Composite Months) of Ionograms

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Electron Density Profile, N(h), data set contains both individual profiles and composite months. The data consist of virtual height/frequency pairs from a...

  15. Particle confinement and density profile behaviour on HL-1M

    Institute of Scientific and Technical Information of China (English)

    Jiao Yi-Ming; Zhou Yan; Deng Zhong-Chao; Ding Xuan-Tong; Liu Yong; Wang En-Yao

    2005-01-01

    In this paper the density profile behaviour and the particle confinement operation regime on HL-1M have been studied under the pellet injection (PI), supersonic molecular beam injection (SMBI), gas puffing (GP) and lower hybrid current drive experimental situations. The relationships between density profile, particle confinement time and edge safe factor have been explored. The density profile, which is measured by six-channel far-infrared ray laser interferometer has been analysed by using the peaking coefficient calculation code. Changes of the outward and inward diffusion velocities before and after the peaking of the central density profile have been calculated using the global particle balance equations. The particle confinement operation regimes have been discussed. The peaking density profile can be easily obtained under the condition of efficient fuelling. In ohmic discharges, confinement time increases as the peaking density profile factor rises, and is saturated at a critical value related to the fuelling efficiency. The particle confinement time of SMBI lies between the values of GP and PI, and its value is about 3-5 times of the energy confinement time.

  16. Numerical Investigation of Galloping Instabilities in Z-Shaped Profiles

    Directory of Open Access Journals (Sweden)

    Ignacio Gomez

    2014-01-01

    Full Text Available Aeroelastic effects are relatively common in the design of modern civil constructions such as office blocks, airport terminal buildings, and factories. Typical flexible structures exposed to the action of wind are shading devices, normally slats or louvers. A typical cross-section for such elements is a Z-shaped profile, made out of a central web and two-side wings. Galloping instabilities are often determined in practice using the Glauert-Den Hartog criterion. This criterion relies on accurate predictions of the dependence of the aerodynamic force coefficients with the angle of attack. The results of a parametric analysis based on a numerical analysis and performed on different Z-shaped louvers to determine translational galloping instability regions are presented in this paper. These numerical analysis results have been validated with a parametric analysis of Z-shaped profiles based on static wind tunnel tests. In order to perform this validation, the DLR TAU Code, which is a standard code within the European aeronautical industry, has been used. This study highlights the focus on the numerical prediction of the effect of galloping, which is shown in a visible way, through stability maps. Comparisons between numerical and experimental data are presented with respect to various meshes and turbulence models.

  17. Profile shape stability and phase jitter analyses of millisecond pulsars

    CERN Document Server

    Liu, K; Lee, K J; Kramer, M; Cordes, J M; Purver, M B

    2011-01-01

    Millisecond pulsars (MSPs) have been studied in detail since their discovery in 1982. The integrated pulse profiles of MSPs appear to be stable, which enables precision monitoring of the pulse times of arrival (TOAs). However, for individual pulses the shape and arrival phase can vary dramatically, which is known as pulse jitter. In this paper, we investigate the stability of integrated pulse profiles for 5 MSPs, and estimate the amount of jitter for PSR J0437-4715. We do not detect intrinsic profile shape variation based on integration times from ~10 to ~100 s with the provided instrumental sensitivity. For PSR J0437-4715 we calculate the jitter parameter to be f_J=0.067+-0.002, and demonstrate that the result is not significantly affected by instrumental TOA uncertainties. Jitter noise is also found to be independent of observing frequency and bandwidth around 1.4 GHz on frequency scales of <100 MHz, which supports the idea that pulses within narrow frequency scale are equally jittered. In addition, we p...

  18. Characterization of Density Profile of Cylindrical Pulsed Gas Jets

    Institute of Scientific and Technical Information of China (English)

    YU Quan-Zhi; LI Yu-Tong; ZhANG Jie; ZHENG Jun; LI Han-Ming; PENG Xiao-Yu; LI Kun

    2004-01-01

    @@ We investigated the characteristics of argon and helium gas jets produced by a cylindrical nozzle under pressures from I to 6 Mpa using a femtosecond laser interferometry. A radial parabolic distribution and an axial exponential distribution of the gas jet density profiles are identified. The results show that the density increases linearly with the backing pressure.

  19. A representative density profile of the North Greenland snowpack

    Science.gov (United States)

    Florian Schaller, Christoph; Freitag, Johannes; Kipfstuhl, Sepp; Laepple, Thomas; Steen-Larsen, Hans Christian; Eisen, Olaf

    2016-09-01

    Along a traverse through North Greenland in May 2015 we collected snow cores up to 2 m depth and analyzed their density and water isotopic composition. A new sampling technique and an adapted algorithm for comparing data sets from different sites and aligning stratigraphic features are presented. We find good agreement of the density layering in the snowpack over hundreds of kilometers, which allows the construction of a representative density profile. The results are supported by an empirical statistical density model, which is used to generate sets of random profiles and validate the applied methods. Furthermore we are able to calculate annual accumulation rates, align melt layers and observe isotopic temperatures in the area back to 2010. Distinct relations of δ18O with both accumulation rate and density are deduced. Inter alia the depths of the 2012 melt layers and high-resolution densities are provided for applications in remote sensing.

  20. Measurements of electron density profiles using an angular filter refractometer

    Energy Technology Data Exchange (ETDEWEB)

    Haberberger, D., E-mail: dhab@lle.rochester.edu; Ivancic, S.; Hu, S. X.; Boni, R.; Barczys, M.; Craxton, R. S.; Froula, D. H. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14636 (United States)

    2014-05-15

    A novel diagnostic technique, angular filter refractometry (AFR), has been developed to characterize high-density, long-scale-length plasmas relevant to high-energy-density physics experiments. AFR measures plasma densities up to 10{sup 21} cm{sup −3} with a 263-nm probe laser and is used to study the plasma expansion from CH foil and spherical targets that are irradiated with ∼9 kJ of ultraviolet (351-nm) laser energy in a 2-ns pulse. The data elucidate the temporal evolution of the plasma profile for the CH planar targets and the dependence of the plasma profile on target radius for CH spheres.

  1. Why are Halo Density Profiles Stable at Formation?

    CERN Document Server

    González-Casado, G; Salvador-Solé, E

    1998-01-01

    We analyze the physical justification of the picture proposed by Salvador-Sole et al. in these proceedings for the time evolution of the universal density profile of dark-matter halos. According to this picture, halos have at formation a stable (i.e. independent of mass and time) dimensionless density profile, the characteristic length and density scales of the profile depending on the underlying cosmogony. Subsequent evolution is driven by mass accretion onto the outskirts of halos and can be characterized simply by the increment of halo radius with time and the corresponding decrease of the critical density of the universe. We find this picture to be a reasonable good description of the expected evolution of halos in hierarchical models of structure formation.

  2. Universal void density profiles from simulation and SDSS

    CERN Document Server

    Nadathur, S; Diego, J M; Iliev, I T; Gottlöber, S; Watson, W A; Yepes, G

    2014-01-01

    We discuss the universality and self-similarity of void density profiles, for voids in realistic mock luminous red galaxy (LRG) catalogues from the Jubilee simulation, as well as in void catalogues constructed from the SDSS LRG and Main Galaxy samples. Voids are identified using a modified version of the ZOBOV watershed transform algorithm, with additional selection cuts. We find that voids in simulation are self-similar, meaning that their average rescaled profile does not depend on the void size, or -- within the range of the simulated catalogue -- on the redshift. Comparison of the profiles obtained from simulated and real voids shows an excellent match. The profiles of real voids also show a universal behaviour over a wide range of galaxy luminosities, number densities and redshifts. This points to a fundamental property of the voids found by the watershed algorithm, which can be exploited in future studies of voids.

  3. Universal void density profiles from simulation and SDSS

    Science.gov (United States)

    Nadathur, S.; Hotchkiss, S.; Diego, J. M.; Iliev, I. T.; Gottlöber, S.; Watson, W. A.; Yepes, G.

    2016-10-01

    We discuss the universality and self-similarity of void density profiles, for voids in realistic mock luminous red galaxy (LRG) catalogues from the Jubilee simulation, as well as in void catalogues constructed from the SDSS LRG and Main Galaxy samples. Voids are identified using a modified version of the ZOBOV watershed transform algorithm, with additional selection cuts. We find that voids in simulation are self-similar, meaning that their average rescaled profile does not depend on the void size, or - within the range of the simulated catalogue - on the redshift. Comparison of the profiles obtained from simulated and real voids shows an excellent match. The profiles of real voids also show a universal behaviour over a wide range of galaxy luminosities, number densities and redshifts. This points to a fundamental property of the voids found by the watershed algorithm, which can be exploited in future studies of voids.

  4. Simulating confined particles with a flat density profile

    Science.gov (United States)

    Korolkovas, Airidas

    2016-08-01

    Particle simulations confined by sharp walls usually develop an oscillatory density profile. For some applications, most notably soft matter liquids, this behavior is often unrealistic and one expects a monotonic density climb instead. To reconcile simulations with experiments, we propose mirror-and-shift boundary conditions where each interface is mapped to a distant part of itself. The main result is that the particle density increases almost monotonically from zero to bulk, over a short distance of about one particle diameter. The method is applied to simulate a polymer brush in explicit solvent, grafted on a flat silicon substrate. The simulated density profile agrees favorably with neutron reflectometry measurements and self-consistent field theory results.

  5. Simulating confined particles with a flat density profile

    CERN Document Server

    Korolkovas, Airidas

    2016-01-01

    Particle simulations confined by sharp walls usually develop an oscillatory density profile. For some applications, most notably soft matter liquids, this behavior is often unrealistic and one expects a monotonic density climb instead. To reconcile simulations with experiments, we propose mirror-and-shift boundary conditions where each interface is mapped to a distant part of itself. The main result is that the particle density increases almost monotonically from zero to bulk, over a short distance of about one particle diameter. The method is applied to simulate a polymer brush in explicit solvent, grafted on a flat silicon substrate. The simulated density profile agrees favorably with neutron reflectometry measurements and self-consistent field theory results.

  6. Open-cluster density profiles derived using a kernel estimator

    CERN Document Server

    Seleznev, Anton F

    2016-01-01

    Surface and spatial radial density profiles in open clusters are derived using a kernel estimator method. Formulae are obtained for the contribution of every star into the spatial density profile. The evaluation of spatial density profiles is tested against open-cluster models from N-body experiments with N = 500. Surface density profiles are derived for seven open clusters (NGC 1502, 1960, 2287, 2516, 2682, 6819 and 6939) using Two-Micron All-Sky Survey data and for different limiting magnitudes. The selection of an optimal kernel half-width is discussed. It is shown that open-cluster radius estimates hardly depend on the kernel half-width. Hints of stellar mass segregation and structural features indicating cluster non-stationarity in the regular force field are found. A comparison with other investigations shows that the data on open-cluster sizes are often underestimated. The existence of an extended corona around the open cluster NGC 6939 was confirmed. A combined function composed of the King density pr...

  7. Statistical ensembles of virialized halo matter density profiles

    CERN Document Server

    Carron, Julien

    2013-01-01

    We define and study statistical ensembles of matter density profiles describing spherically symmetric, virialized dark matter haloes of finite extent with a given mass and total gravitational potential energy. We provide an exact solution for the grand canonical partition functional, and show its equivalence to that of the microcanonical ensemble. We obtain analytically the mean profiles that correspond to an overwhelming majority of micro-states. All such profiles have an infinitely deep potential well, with the singular isothermal sphere arising in the infinite temperature limit. Systems with virial radius larger than gravitational radius exhibit a localization of a finite fraction of the energy in the very center. The universal logarithmic inner slope of unity of the NFW haloes is predicted at any mass and energy if an upper bound is set to the maximal depth of the potential well. In this case, the statistically favored mean profiles compare well to the NFW profiles. For very massive haloes the agreement b...

  8. Relationship between the shape and density distribution of the femur and its natural frequencies of vibration.

    Science.gov (United States)

    Campoli, G; Baka, N; Kaptein, B L; Valstar, E R; Zachow, S; Weinans, H; Zadpoor, A A

    2014-10-17

    It has been recently suggested that mechanical loads applied at frequencies close to the natural frequencies of bone could enhance bone apposition due to the resonance phenomenon. Other applications of bone modal analysis are also suggested. For the above-mentioned applications, it is important to understand how patient-specific bone shape and density distribution influence the natural frequencies of bones. We used finite element models to study the effects of bone shape and density distribution on the natural frequencies of the femur in free boundary conditions. A statistical shape and appearance model that describes shape and density distribution independently was created, based on a training set of 27 femora. The natural frequencies were then calculated for different shape modes varied around the mean shape while keeping the mean density distribution, for different appearance modes around the mean density distribution while keeping the mean bone shape, and for the 27 training femora. Single shape or appearance modes could cause up to 15% variations in the natural frequencies with certain modes having the greatest impact. For the actual femora, shape and density distribution changed the natural frequencies by up to 38%. First appearance mode that describes the general cortical bone thickness and trabecular bone density had one of the strongest impacts. The first appearance mode could therefore provide a sensitive measure of general bone health and disease progression. Since shape and density could cause large variations in the calculated natural frequencies, patient-specific FE models are needed for accurate estimation of bone natural frequencies.

  9. An Examination of FORMOSAT-3/COSMIC Ionospheric Electron Density Profile: Data Quality Criteria and Comparisons with the IRI Model

    Directory of Open Access Journals (Sweden)

    Kuo-Feng Yang

    2009-01-01

    Full Text Available In this article, we analyze the properties of ionospheric electron density profiling retrieved from FORMOSAT-3/COSMIC radio occultation measurements. Two parameters, namely, the gradient and fluctuation of the topside electron density profile, serve as indicators to quantitatively describe the data quality of the retrieved electron density profile. On the basis of 8 month data (June 2006 - January 2007, we find that on average 93% of the electron density profiles have upper electron density gradients and electron density fluctuations smaller than -0.02 #/m3/m and 0.2, respectively, which can be treated as good data for further analysis. The same results are also achieved for the peak height of the electron density. After removing the questionable data, we compare the general behaviors of the electron density between FORMOSAT-3 and the IRI model. It is found that the global distributions of the peak height and the peak electron density for the FORMOSAT-3/COSMIC data are generally consistent with those for the IRI model. However, a significant difference between their scale heights of the topside electron density profiles is found. It suggests that the shape of the topside electron density profile in the IRI model should be revised accordingly such that it more closely resembles the real situation.

  10. New signal processing technique for density profile reconstruction using reflectometry

    Energy Technology Data Exchange (ETDEWEB)

    Clairet, F.; Bottereau, C. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Ricaud, B. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); CPT UMR 6207, Campus de Luminy, case 907, F-13288 Marseille (France); Briolle, F. [CPT UMR 6207, Campus de Luminy, case 907, F-13288 Marseille (France); CReA, BA 701, F-13306 Salon de Provence (France); Heuraux, S. [IJL-P2M, UMR-CNRS 7198, Universite Henri Poincare, F-54506 Vandoeuvre (France)

    2011-08-15

    Reflectometry profile measurement requires an accurate determination of the plasma reflected signal. Along with a good resolution and a high signal to noise ratio of the phase measurement, adequate data analysis is required. A new data processing based on time-frequency tomographic representation is used. It provides a clearer separation between multiple components and improves isolation of the relevant signals. In this paper, this data processing technique is applied to two sets of signals coming from two different reflectometer devices used on the Tore Supra tokamak. For the standard density profile reflectometry, it improves the initialization process and its reliability, providing a more accurate profile determination in the far scrape-off layer with density measurements as low as 10{sup 16} m{sup -1}. For a second reflectometer, which provides measurements in front of a lower hybrid launcher, this method improves the separation of the relevant plasma signal from multi-reflection processes due to the proximity of the plasma.

  11. MultiDark simulations: the story of dark matter halo concentrations and density profiles

    CERN Document Server

    Klypin, Anatoly; Gottlober, Stefan; Prada, Francisco; Hess, Steffen

    2014-01-01

    Accurately predicting structural properties of dark matter halos is one of the fundamental goals of modern cosmology. We use the new suite of MultiDark cosmological simulations to study the evolution of dark matter halo density profiles, concentrations, and velocity anisotropies. The MultiDark simulations cover a large range of masses 1e10-1e15Msun and volumes upto 50Gpc**3. The total number of dark matter halos in all the simulations exceeds 60 billion. We find that in order to understand the structure of dark matter halos and to make ~1% accurate predictions for density profiles, one needs to realize that halo concentration is more complex than the traditional ratio of the virial radius to the core radius in the NFW profile. For massive halos the averge density profile is far from the NFW shape and the concentration is defined by both the core radius and the shape parameter alpha in the Einasto approximation. Combining results from different redshifts, masses and cosmologies, we show that halos progress thr...

  12. Real-time control of the plasma density profile on ASDEX upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Mlynek, Alexander

    2010-07-20

    The tokamak concept currently is the most promising approach to future power generation by controlled thermonuclear fusion. The spatial distribution of the particle density in the toroidally confined fusion plasma is of particular importance. This thesis work therefore focuses on the question as to what extent the shape of the density profile can be actively controlled by a feedback loop in the fusion experiment ASDEX Upgrade. There are basically two essential requirements for such feedback control of the density profile, which has been experimentally demonstrated within the scope of this thesis work: On the one hand, for this purpose the density profile must be continuously calculated under real-time constraints during a plasma discharge. The calculation of the density profile is based on the measurements of a sub-millimeter interferometer, which provides the line-integrated electron density along 5 chords through the plasma. Interferometric density measurements can suffer from counting errors by integer multiples of 2{pi} when detecting the phase difference between a probing and a reference beam. As such measurement errors have severe impact on the reconstructed density profile, one major part of this work consists in the development of new readout electronics for the interferometer, which allows for detection of such measurement errors in real-time with high reliability. A further part of this work is the design of a computer algorithm which reconstructs the spatial distribution of the plasma density from the line-integrated measurements. This algorithm has to be implemented on a computer which communicates the measured data to other computers in real-time, especially to the tokamak control system. On the other hand, a second fundamental requirement for the successful implementation of a feedback controller is the identification of at least one actuator which enables a modification of the density profile. Here, electron cyclotron resonance heating (ECRH) has

  13. Profiling compact toroid plasma density on CTIX with laser deflection

    Science.gov (United States)

    Brockington, Samuel Joseph Erwin

    A laser deflectometer measures line-integrated plasma density gradient using laser diodes and amplified point detectors. A laser passing through an optically thin plasma is refracted by an amount proportional to the line-integrated electron density gradient. I have designed, installed, and operated a deflection diagnostic for the Compact Toroid Injection Experiment (CTIX), a plasma rail gun which can create compact toroid (CT) plasmas of controllable density and velocity. The diagnostic design and motivation are discussed, as well as three experiments performed with deflectometry. Thus, my thesis consists of the design of the deflectometer diagnostic, a comparison of its accuracy to interferometer density measurements, and finally a survey of compact toroid density profiles in two dimensions conducted with an array of detectors.

  14. Ionospheric topside models compared with experimental electron density profiles

    Directory of Open Access Journals (Sweden)

    S. M. Radicella

    2005-06-01

    Full Text Available Recently an increasing number of topside electron density profiles has been made available to the scientific community on the Internet. These data are important for ionospheric modeling purposes, since the experimental information on the electron density above the ionosphere maximum of ionization is very scarce. The present work compares NeQuick and IRI models with the topside electron density profiles available in the databases of the ISIS2, IK19 and Cosmos 1809 satellites. Experimental electron content from the F2 peak up to satellite height and electron densities at fixed heights above the peak have been compared under a wide range of different conditions. The analysis performed points out the behavior of the models and the improvements needed to be assessed to have a better reproduction of the experimental results. NeQuick topside is a modified Epstein layer, with thickness parameter determined by an empirical relation. It appears that its performance is strongly affected by this parameter, indicating the need for improvements of its formulation. IRI topside is based on Booker's approach to consider two parts with constant height gradients. It appears that this formulation leads to an overestimation of the electron density in the upper part of the profiles, and overestimation of TEC.

  15. Determination of coronal temperatures from electron density profiles

    CERN Document Server

    Lemaire, J F

    2011-01-01

    The most popular method for determining coronal temperatures is the scale-height-method (shm). It is based on electron density profiles inferred from White Light (WL) brightness measurements of the corona during solar eclipses. This method has been applied to several published coronal electron density models. The calculated temperature distributions reach a maximum at r > 1.3 RS, and therefore do not satisfy one of the conditions for applying the shm method. Another method is the hydrostatic equilibrium method (hst), which enables coronal temperature distributions to be determined, providing solutions to the hydrostatic equilibrium equation. The temperature maximas using the hst method are almost equal to those obtained using the shm method, but the temperature peak is always at significantly lower altitude when the hst-method is used than when the shm-method is used. A third and more recently developed method, dyn, can be used for the same published electron density profiles. The temperature distributions ob...

  16. Automated volumetric breast density derived by shape and appearance modeling

    Science.gov (United States)

    Malkov, Serghei; Kerlikowske, Karla; Shepherd, John

    2014-03-01

    The image shape and texture (appearance) estimation designed for facial recognition is a novel and promising approach for application in breast imaging. The purpose of this study was to apply a shape and appearance model to automatically estimate percent breast fibroglandular volume (%FGV) using digital mammograms. We built a shape and appearance model using 2000 full-field digital mammograms from the San Francisco Mammography Registry with known %FGV measured by single energy absorptiometry method. An affine transformation was used to remove rotation, translation and scale. Principal Component Analysis (PCA) was applied to extract significant and uncorrelated components of %FGV. To build an appearance model, we transformed the breast images into the mean texture image by piecewise linear image transformation. Using PCA the image pixels grey-scale values were converted into a reduced set of the shape and texture features. The stepwise regression with forward selection and backward elimination was used to estimate the outcome %FGV with shape and appearance features and other system parameters. The shape and appearance scores were found to correlate moderately to breast %FGV, dense tissue volume and actual breast volume, body mass index (BMI) and age. The highest Pearson correlation coefficient was equal 0.77 for the first shape PCA component and actual breast volume. The stepwise regression method with ten-fold cross-validation to predict %FGV from shape and appearance variables and other system outcome parameters generated a model with a correlation of r2 = 0.8. In conclusion, a shape and appearance model demonstrated excellent feasibility to extract variables useful for automatic %FGV estimation. Further exploring and testing of this approach is warranted.

  17. Kernel density estimation of a multidimensional efficiency profile

    CERN Document Server

    Poluektov, Anton

    2014-01-01

    Kernel density estimation is a convenient way to estimate the probability density of a distribution given the sample of data points. However, it has certain drawbacks: proper description of the density using narrow kernels needs large data samples, whereas if the kernel width is large, boundaries and narrow structures tend to be smeared. Here, an approach to correct for such effects, is proposed that uses an approximate density to describe narrow structures and boundaries. The approach is shown to be well suited for the description of the efficiency shape over a multidimensional phase space in a typical particle physics analysis. An example is given for the five-dimensional phase space of the $\\Lambda_b^0\\to D^0p\\pi$ decay.

  18. Midplane neutral density profiles in the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Stotler, D. P., E-mail: dstotler@pppl.gov; Bell, R. E.; Diallo, A.; LeBlanc, B. P.; Podestà, M.; Roquemore, A. L.; Ross, P. W. [Princeton Plasma Physics Laboratory, Princeton University, P. O. Box 451, Princeton, New Jersey 08543-0451 (United States); Scotti, F. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

    2015-08-15

    Atomic and molecular density data in the outer midplane of NSTX [Ono et al., Nucl. Fusion 40, 557 (2000)] are inferred from tangential camera data via a forward modeling procedure using the DEGAS 2 Monte Carlo neutral transport code. The observed Balmer-β light emission data from 17 shots during the 2010 NSTX campaign display no obvious trends with discharge parameters such as the divertor Balmer-α emission level or edge deuterium ion density. Simulations of 12 time slices in 7 of these discharges produce molecular densities near the vacuum vessel wall of 2–8 × 10{sup 17 }m{sup −3} and atomic densities ranging from 1 to 7 × 10{sup 16 }m{sup −3}; neither has a clear correlation with other parameters. Validation of the technique, begun in an earlier publication, is continued with an assessment of the sensitivity of the simulated camera image and neutral densities to uncertainties in the data input to the model. The simulated camera image is sensitive to the plasma profiles and virtually nothing else. The neutral densities at the vessel wall depend most strongly on the spatial distribution of the source; simulations with a localized neutral source yield densities within a factor of two of the baseline, uniform source, case. The uncertainties in the neutral densities associated with other model inputs and assumptions are ≤50%.

  19. Density profiles of dark matter halos with anisotropic velocity tensors

    CERN Document Server

    Hiotelis, N

    2002-01-01

    We present density profiles, that are solutions of the spherical Jeans equation, derived under the following two assumptions: (i) the coarse grained phase-density follows a power-law of radius, rho/(sigma^3) proportional to r^{-alpha}, and (ii) the velocity anisotropy parameter is given by the relation beta_a(r) = beta_1 + 2 beta_2 {(r/r_*)/(1+(r/r_*)^2)} where beta_1, beta_2 are parameters and r_* equals twice the virial radius, r_{vir}, of the system. These assumptions are well motivated by the results of N-body simulations. Density profiles have increasing logarithmic slopes gamma, defined by gamma = - {(d ln rho)/(d ln r)}. The values of gamma at r = 10^{-2.5}r_{vir}, a distance where the systems could be resolved by large N-body simulations, lie in the range 1. - 1.6. These inner values of gamma increase for increasing beta_1 and for increasing concentration of the system. On the other hand, slopes at r = r_{vir} lie in the range 2.42 - 3.82. A model density profile that fits well the results at radial d...

  20. Effect of particle shape on the random packing density of amorphous solids

    NARCIS (Netherlands)

    Kyrylyuk, A.V.; Philipse, A.P.

    2011-01-01

    The packing density of a particulate solid strongly depends on the shape of the particles that are jammed at random close packing (RCP). To investigate the effect of particle shape on the RCP density of an amorphous solid, we studied jammed packings of binary mixtures of a-thermal or granular sphero

  1. Lensing Constraints on the Mass Profile Shape and Splashback Radius of Galaxy Clusters

    CERN Document Server

    Umetsu, Keiichi

    2016-01-01

    The lensing signal around galaxy clusters can, in principle, be used to test detailed predictions for their average mass profile from numerical simulations. However, the intrinsic shape of the profiles can be smeared out when a sample that spans a wide range of cluster masses is averaged in physical length units. This effect especially conceals rapid changes in gradient such as the steep drop associated with the splashback radius, a sharp edge corresponding to the outermost caustic in accreting halos. We optimize the extraction of such local features by scaling individual halo profiles to a number of spherical overdensity radii, and apply this method to 16 X-ray-selected high-mass clusters targeted in the Cluster Lensing And Supernova survey with Hubble. By forward-modeling the weak and strong lensing data presented in Umetsu et al., we show that, regardless of the scaling overdensity, the projected ensemble density profile is remarkably well described by an NFW or Einasto profile out to $R \\sim 2.5h^{-1}$Mpc...

  2. Fingerprints of the initial conditions on the density profiles of cold and warm dark matter haloes

    CERN Document Server

    Polisensky, E

    2015-01-01

    We use N-body simulations of dark matter haloes in cold dark matter (CDM) and a large set of different warm dark matter (WDM) cosmologies to demonstrate that the spherically averaged density profile of dark matter haloes has a shape that depends on the power spectrum of matter perturbations. Density profiles are steeper in WDM but become shallower at scales less than one percent of the virial radius. Virialization isotropizes the velocity dispersion in the inner regions of the halo but does not erase the memory of the initial conditions in phase space. The location of the observed deviations from CDM in the density profile and in phase space can be directly related to the ratio between the halo mass and the filtering mass and are most evident in small mass haloes, even for a 34 keV thermal relic WDM. The rearrangement of mass within the haloes supports analytic models of halo structure that include angular momentum. We also find evidence of a dependence of the slope of the inner density profile in CDM cosmolo...

  3. Evolution of density profiles in high-z galaxies: compaction and quenching inside-out

    Science.gov (United States)

    Tacchella, Sandro; Dekel, Avishai; Carollo, C. Marcella; Ceverino, Daniel; DeGraf, Colin; Lapiner, Sharon; Mandelker, Nir; Primack, Joel R.

    2016-05-01

    Using cosmological simulations, we address the interplay between structure and star formation in high-redshift galaxies via the evolution of surface density profiles. Our sample consists of 26 galaxies evolving in the redshift range z = 7 - 1, spanning the stellar mass range (0.2-6.4) × 1010 M⊙ at z = 2. We recover the main trends by stacking the profiles in accordance to their evolution phases. Following a wet compaction event that typically occurs when the stellar mass is ˜109.5 M⊙ at z ˜ 2-4, the gas develops a cusp inside the effective radius, associated with a peak in star formation rate (SFR). The SFR peak and the associated feedback, in the absence of further gas inflow to the centre, marks the onset of gas depletion from the central 1 kpc, leading to quenching of the central SFR. An extended, star-forming ring that forms by fresh gas during the central quenching process shows as a rising specific SFR (sSFR) profile, which is interpreted as inside-out quenching. Before quenching, the stellar density profile grows self-similarly, maintaining its log-log shape because the sSFR is similar at all radii. During the quenching process, the stellar density saturates to a constant value, especially in the inner 1 kpc. The stellar mass and SFR profiles deduced from observations show very similar shapes, consistent with the scenario of wet compaction leading to inside-out quenching and the subsequent saturation of a dense stellar core. We predict a cuspy gas profile during the blue nugget phase, and a gas-depleted core, sometimes surrounded by a ring, in the post-blue nugget phase.

  4. The Stellar Density Profile of the Distant Galactic Halo

    CERN Document Server

    Slater, Colin T; Munn, Jeffrey A; Bell, Eric F; Majewski, Steven R

    2016-01-01

    We use extensive gravity-sensitive DDO 51 photometry over 5100 square degrees, combined with SDSS broadband photometry, to select a catalog of $\\sim 4,000$ giant stars covering a large fraction of the high Galactic latitude sky and reaching out to $\\sim 80$ kpc in the Galactic halo. This sample of bright and unbiased tracers enables us to measure the radial profile and 3D structure of the stellar halo to large distance which had previously only been measured with sparse tracers or small samples. Using population synthesis models to reproduce the observed giant star luminosity function, we find that the halo maintains a $r^{-3.5}$ profile from $30$ to $80$ kpc with no signs of a truncation or sharp break over this range. The radial profile measurement is largely insensitive to individual halo substructure components, but we find that attempting to measure the shape of the halo is overwhelmed by the Sagittarius stream such that no ellipsoidal shape is a satisfactory description in this region. These measurement...

  5. Implementation of the new multichannel X-mode edge density profile reflectometer for the ICRF antenna on ASDEX Upgrade

    Science.gov (United States)

    Aguiam, D. E.; Silva, A.; Bobkov, V.; Carvalho, P. J.; Carvalho, P. F.; Cavazzana, R.; Conway, G. D.; D'Arcangelo, O.; Fattorini, L.; Faugel, H.; Fernandes, A.; Fünfgelder, H.; Gonçalves, B.; Guimarais, L.; De Masi, G.; Meneses, L.; Noterdaeme, J. M.; Pereira, R. C.; Rocchi, G.; Santos, J. M.; Tuccillo, A. A.; Tudisco, O.

    2016-11-01

    A new multichannel frequency modulated continuous-wave reflectometry diagnostic has been successfully installed and commissioned on ASDEX Upgrade to measure the plasma edge electron density profile evolution in front of the Ion Cyclotron Range of Frequencies (ICRF) antenna. The design of the new three-strap ICRF antenna integrates ten pairs (sending and receiving) of microwave reflectometry antennas. The multichannel reflectometer can use three of these to measure the edge electron density profiles up to 2 × 1019 m-3, at different poloidal locations, allowing the direct study of the local plasma layers in front of the ICRF antenna. ICRF power coupling, operational effects, and poloidal variations of the plasma density profile can be consistently studied for the first time. In this work the diagnostic hardware architecture is described and the obtained density profile measurements were used to track outer radial plasma position and plasma shape.

  6. Implementation of the new multichannel X-mode edge density profile reflectometer for the ICRF antenna on ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Aguiam, D. E., E-mail: daguiam@ipfn.tecnico.ulisboa.pt; Silva, A.; Carvalho, P. J.; Carvalho, P. F.; Fernandes, A.; Gonçalves, B.; Guimarais, L.; Meneses, L.; Pereira, R. C.; Santos, J. M. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Bobkov, V.; Conway, G. D.; Faugel, H.; Fünfgelder, H. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Cavazzana, R.; De Masi, G. [Consorzio RFX (CNR, ENEA, INFN, Universitá di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); D’Arcangelo, O.; Rocchi, G.; Tuccillo, A. A. [ENEA, Dipartimento FSN, C. R. Frascati, Via E. Fermi 45, 00044 Frascati, Roma (Italy); and others

    2016-11-15

    A new multichannel frequency modulated continuous-wave reflectometry diagnostic has been successfully installed and commissioned on ASDEX Upgrade to measure the plasma edge electron density profile evolution in front of the Ion Cyclotron Range of Frequencies (ICRF) antenna. The design of the new three-strap ICRF antenna integrates ten pairs (sending and receiving) of microwave reflectometry antennas. The multichannel reflectometer can use three of these to measure the edge electron density profiles up to 2 × 10{sup 19} m{sup −3}, at different poloidal locations, allowing the direct study of the local plasma layers in front of the ICRF antenna. ICRF power coupling, operational effects, and poloidal variations of the plasma density profile can be consistently studied for the first time. In this work the diagnostic hardware architecture is described and the obtained density profile measurements were used to track outer radial plasma position and plasma shape.

  7. Computational lipidology: predicting lipoprotein density profiles in human blood plasma.

    Directory of Open Access Journals (Sweden)

    Katrin Hübner

    2008-05-01

    Full Text Available Monitoring cholesterol levels is strongly recommended to identify patients at risk for myocardial infarction. However, clinical markers beyond "bad" and "good" cholesterol are needed to precisely predict individual lipid disorders. Our work contributes to this aim by bringing together experiment and theory. We developed a novel computer-based model of the human plasma lipoprotein metabolism in order to simulate the blood lipid levels in high resolution. Instead of focusing on a few conventionally used predefined lipoprotein density classes (LDL, HDL, we consider the entire protein and lipid composition spectrum of individual lipoprotein complexes. Subsequently, their distribution over density (which equals the lipoprotein profile is calculated. As our main results, we (i successfully reproduced clinically measured lipoprotein profiles of healthy subjects; (ii assigned lipoproteins to narrow density classes, named high-resolution density sub-fractions (hrDS, revealing heterogeneous lipoprotein distributions within the major lipoprotein classes; and (iii present model-based predictions of changes in the lipoprotein distribution elicited by disorders in underlying molecular processes. In its present state, the model offers a platform for many future applications aimed at understanding the reasons for inter-individual variability, identifying new sub-fractions of potential clinical relevance and a patient-oriented diagnosis of the potential molecular causes for individual dyslipidemia.

  8. LPWA using supersonic gas jet with tailored density profile

    Science.gov (United States)

    Kononenko, O.; Bohlen, S.; Dale, J.; D'Arcy, R.; Dinter, M.; Erbe, J. H.; Indorf, G.; di Lucchio, L.; Goldberg, L.; Gruse, J. N.; Karstensen, S.; Libov, V.; Ludwig, K.; Martinez de La Ossa, A.; Marutzky, F.; Niroula, A.; Osterhoff, J.; Quast, M.; Schaper, L.; Schwinkendorf, J.-P.; Streeter, M.; Tauscher, G.; Weichert, S.; Palmer, C.; Horbatiuk, Taras

    2016-10-01

    Laser driven plasma wakefield accelerators have been explored as a potential compact, reproducible source of relativistic electron bunches, utilising an electric field of many GV/m. Control over injection of electrons into the wakefield is of crucial importance in producing stable, mono-energetic electron bunches. Density tailoring of the target, to control the acceleration process, can also be used to improve the quality of the bunch. By using gas jets to provide tailored targets it is possible to provide good access for plasma diagnostics while also producing sharp density gradients for density down-ramp injection. OpenFOAM hydrodynamic simulations were used to investigate the possibility of producing tailored density targets in a supersonic gas jet. Particle-in-cell simulations of the resulting density profiles modelled the effect of the tailored density on the properties of the accelerated electron bunch. Here, we present the simulation results together with preliminary experimental measurements of electron and x-ray properties from LPWA experiments using gas jet targets and a 25 TW, 25 fs Ti:Sa laser system at DESY.

  9. Comparison of density cutters for snow profile observations

    Science.gov (United States)

    Conger, Steven M.; McClung, David M.

    An investigation was made to estimate the variance, measurement errors and sampling error in currently accepted practices for manual snow density measurement carried out as part of snow profile observations using the available variety of density cutters. A field experiment in dry snow conditions was conducted using a randomized block design to account for layer spatial variability. Cutter types included a 500 cm3 aluminium tube, 200 and 100 cm3 stainless-steel box types, 200 cm3 stainless-steel wedge types and a 100 cm3 stainless-steel tube. Without accounting for variation due to weighing devices, the range of values for 'accepted practice' determined in this study included variation within individual cutters of 0.8-6.2%, variation between cutters of 3-12%, variation between cutter means and layer means of 2-7%, and under-sampling errors of 0-2%. The results of a statistical analysis suggest that snow density measurements taken using various density cutters are significantly different from each other. Without adjustment for under-sampling, and given that the mean of all measurements is the accepted true value of the layer density, variation exclusively between cutter types provides 'accepted practice' measurements that are within 11% of the true density.

  10. Proton Stopping Power of Different Density Profile Plasmas

    CERN Document Server

    Casas, David; Andreev, Alexander A; Schnürer, Matthias; Morales, Roberto

    2014-01-01

    In this work, the stopping power of a partially ionized plasma is analyzed by means of free electron stopping and bound electron stopping. For the first one, the RPA dielectric function is used, and for the latter one, an interpolation of high and low projectile velocity formulas is used. The dynamical energy loss of an ion beam inside a plasma is estimated by using an iterative scheme of calculation. The Abel inversion is also applied when we have a plasma with radial symmetry. Finally, we compare our methods with two kind of plasmas. In the first one, we estimate the energy loss in a plasma created by a laser prepulse, whose density is approximated by a piecewise function. For the latter one, a radial electron density is supposed and the stopping is obtained as function of radius from the calculated lateral points. In both cases, the dependence with the density profile is observed.

  11. PROTON STOPPING POWER OF DIFFERENT DENSITY PROFILE PLASMAS

    Directory of Open Access Journals (Sweden)

    David Casas

    2015-04-01

    Full Text Available In this work, the stopping power of a partially ionized plasma is analyzed by means of free electron stopping and bound electron stopping. For the first instance, the RPA dielectric function is used, and for the latter one, an interpolation of high and low projectile velocity formulas is used. The dynamical energy loss of a ion beam inside a plasma is estimated by using an iterative scheme of calculation. The Abel inversion is also applied when we have a plasma with radial symmetry. Finally, we compare our methods with two kind of plasmas. In the first one, we estimate the energy loss in a plasma created by a laser prepulse, whose density is approximated by a piecewise function. For the latter one, a radial electron density is supposed and the stopping is obtained as a function of radius from the calculated lateral points. In both cases, the dependence with the density profile is observed.

  12. Lensing Constraints on the Mass Profile Shape and the Splashback Radius of Galaxy Clusters

    Science.gov (United States)

    Umetsu, Keiichi; Diemer, Benedikt

    2017-02-01

    The lensing signal around galaxy clusters can, in principle, be used to test detailed predictions for their average mass profile from numerical simulations. However, the intrinsic shape of the profiles can be smeared out when a sample that spans a wide range of cluster masses is averaged in physical length units. This effect especially conceals rapid changes in gradient such as the steep drop associated with the splashback radius, a sharp edge corresponding to the outermost caustic in accreting halos. We optimize the extraction of such local features by scaling individual halo profiles to a number of spherical overdensity radii, and apply this method to 16 X-ray-selected, high-mass clusters targeted in the Cluster Lensing And Supernova survey with Hubble. By forward-modeling the weak- and strong-lensing data presented by Umetsu et al., we show that, regardless of the scaling overdensity, the projected ensemble density profile is remarkably well described by a Navarro–Frenk–White (NFW) or Einasto profile out to R∼ 2.5 {h}-1 {Mpc}, beyond which the profiles flatten. We constrain the NFW concentration to {c}200{{c}}=3.66+/- 0.11 at {M}200{{c}}≃ 1.0× {10}15 {h}-1 {M}ȯ , consistent with and improved from previous work that used conventionally stacked lensing profiles, and in excellent agreement with theoretical expectations. Assuming the profile form of Diemer & Kravtsov and generic priors calibrated from numerical simulations, we place a lower limit on the splashback radius of the cluster halos, if it exists, of {R}{sp}3{{D}}/{r}200{{m}}> 0.89 ({R}{sp}3{{D}}> 1.83 {h}-1 {Mpc}) at 68% confidence. The corresponding density feature is most pronounced when the cluster profiles are scaled by {r}200{{m}}, and smeared out when scaled to higher overdensities. Based in part on data collected at the Subaru Telescope, which is operated by the National Astronomical Society of Japan.

  13. Level density and shape changes in excited sd shell nuclei

    Indian Academy of Sciences (India)

    S Santosh Kumar

    2008-07-01

    In the present calculation we have used the Monte Carlo method of generating collective spin and total energy of the nucleus for various configurations of the system with 0 single particle states available for n number of particles. The different configurations (arrangements of occupied single particle states) leading to a particular energy and spin are then collected to get the density of states for the given energy and spin . We find that if we use the cranked Nilsson model single particle states for the rotational frequency = 0.0ħω, 0.05ħω and 0.1ħω there is a shift in the maximum density of states max with a tendency for the system to become more oblate or prolate depending on the shift in the maximum density of states as the angular momentum decreases or increases. The change in nuclear level density with collectivity, i.e. with the use of cranked Nilsson model single particle levels has been noticed.

  14. MultiDark simulations: the story of dark matter halo concentrations and density profiles

    Science.gov (United States)

    Klypin, Anatoly; Yepes, Gustavo; Gottlöber, Stefan; Prada, Francisco; Heß, Steffen

    2016-04-01

    Predicting structural properties of dark matter haloes is one of the fundamental goals of modern cosmology. We use the suite of MultiDark cosmological simulations to study the evolution of dark matter halo density profiles, concentrations, and velocity anisotropies. We find that in order to understand the structure of dark matter haloes and to make 1-2 per cent accurate predictions for density profiles, one needs to realize that halo concentration is more complex than the ratio of the virial radius to the core radius in the Navarro-Frenk-White (NFW) profile. For massive haloes, the average density profile is far from the NFW shape and the concentration is defined by both the core radius and the shape parameter α in the Einasto approximation. We show that haloes progress through three stages of evolution. They start as rare density peaks and experience fast and nearly radial infall that brings mass closer to the centre, producing a highly concentrated halo. Here, the halo concentration increases with increasing halo mass and the concentration is defined by the α parameter with a nearly constant core radius. Later haloes slide into the plateau regime where the accretion becomes less radial, but frequent mergers still affect even the central region. At this stage, the concentration does not depend on halo mass. Once the rate of accretion and merging slows down, haloes move into the domain of declining concentration-mass relation because new accretion piles up mass close to the virial radius while the core radius is staying constant. Accurate analytical fits are provided.

  15. Full-density, net-shape powder consolidation using dynamic magnetic pulse pressures

    Science.gov (United States)

    Chelluri, Bhanu; Barber, John P.

    1999-07-01

    The full-density consolidation of powders into net-shape parts yields high green strength, low shrinkage, short sinter times, superior mechanical properties, and low manufacturing costs. The conventional lowcost, single-press, single-sinter process typically densifies powders at less than 65 percent green density. This article describes the Magnepress™ process, a powder-processing technique wherein pulsed magnetic pressures consolidate powders into full-density parts without admixed lubricants or binders. The Magnepress technique is especially suitable for producing net-shape products with radial symmetry (e.g., rods, cylindrical parts with internal features, tubular shapes, and high aspect-ratio specimens).

  16. Variations in a Universal Density Profile for the Milky Way's Dwarf Spheroidal Galaxies

    Science.gov (United States)

    Jardel, John; Gebhardt, K.

    2014-01-01

    On the largest scales, the Cold Dark Matter (CDM) paradigm for structure formation has enjoyed remarkable success in describing the universe we live in. The current frontier in our knowledge of galaxy formation is at the low-mass level. Here we find disagreement between theory and observations in a number of interesting cases. One such problem that has received considerable attention is the debate over the shape of the dark matter density profiles in the Milky Way's dwarf spheroidal (dSph) galaxies, known as the core/cusp problem. CDM simulations predict every halo should have a cuspy profile with an inner logarithmic slope of -1, but some observers have found that profiles with constant density inner cores are preferred. However, a major weakness of this previous work is that the dynamical models constructed to measure the mass distribution have had to assume a parameterization for the dark matter profile--exactly the thing one wishes to measure. For my thesis I introduced a new modeling technique, based on Schwarzschild's method, that instead calculates the dark matter profile non-parametrically. Applying these models to five of the Milky Way's dSphs I found a variety of profile shapes including cores, cusps, and other completely unexpected shapes. When scaled to a common normalization, however, I found the combined profile appears to follow an approximate power law with slope -1. The results of this averaging suggest that the individual formation histories of each galaxy produce differing dark matter profiles, but with a net result that is similar to CDM predictions. To better understand the role baryons play in this process, I compare my results to recent hydrodynamical simulations of the formation of dwarf galaxies. Together, my results and the simulations suggest a trend of flatter profiles in galaxies where more stars have formed. This implies that star formation and dark matter halos are linked through the effects of supernova-induced outflows which are

  17. Behavioural profiles are shaped by social experience: when, how and why

    OpenAIRE

    Sachser, Norbert; Kaiser, Sylvia; Hennessy, Michael B.

    2013-01-01

    The comprehensive understanding of individual variation in behavioural profiles is a current and timely topic not only in behavioural ecology, but also in biopsychological and biomedical research. This study focuses on the shaping of behavioural profiles by the social environment in mammals. We review evidence that the shaping of behavioural profiles occurs from the prenatal phase through adolescence and beyond. We focus specifically on adolescence, a sensitive phase during which environmenta...

  18. Isotope and density profile effects on pedestal neoclassical transport

    Science.gov (United States)

    Buller, S.; Pusztai, I.

    2017-10-01

    Cross-field neoclassical transport of heat, particles and momentum is studied in sharp density pedestals, with a focus on isotope and profile effects, using a radially global approach. Global effects—which tend to reduce the peak ion heat flux, and shift it outward—increase with isotope mass for fixed profiles. The heat flux reduction exhibits a saturation with a favorable isotopic trend. A significant part of the heat flux can be convective even in pure plasmas, unlike in the plasma core, and it is sensitive to how momentum sources are distributed between the various species. In particular, if only ion momentum sources are allowed, in global simulations of pure plasmas the ion particle flux remains close to its local value, while this may not be the case for simulations with isotope mixtures or electron momentum sources. The radial angular momentum transport that is a finite orbit width effect, is found to be strongly correlated with heat sources.

  19. Element-specific density profiles in interacting biomembrane models

    Science.gov (United States)

    Schneck, Emanuel; Rodriguez-Loureiro, Ignacio; Bertinetti, Luca; Marin, Egor; Novikov, Dmitri; Konovalov, Oleg; Gochev, Georgi

    2017-03-01

    Surface interactions involving biomembranes, such as cell–cell interactions or membrane contacts inside cells play important roles in numerous biological processes. Structural insight into the interacting surfaces is a prerequisite to understand the interaction characteristics as well as the underlying physical mechanisms. Here, we work with simplified planar experimental models of membrane surfaces, composed of lipids and lipopolymers. Their interaction is quantified in terms of pressure–distance curves using ellipsometry at controlled dehydrating (interaction) pressures. For selected pressures, their internal structure is investigated by standing-wave x-ray fluorescence (SWXF). This technique yields specific density profiles of the chemical elements P and S belonging to lipid headgroups and polymer chains, as well as counter-ion profiles for charged surfaces.

  20. Balancing selection shapes density-dependent foraging behaviour.

    Science.gov (United States)

    Greene, Joshua S; Brown, Maximillian; Dobosiewicz, May; Ishida, Itzel G; Macosko, Evan Z; Zhang, Xinxing; Butcher, Rebecca A; Cline, Devin J; McGrath, Patrick T; Bargmann, Cornelia I

    2016-11-10

    The optimal foraging strategy in a given environment depends on the number of competing individuals and their behavioural strategies. Little is known about the genes and neural circuits that integrate social information into foraging decisions. Here we show that ascaroside pheromones, small glycolipids that signal population density, suppress exploratory foraging in Caenorhabditis elegans, and that heritable variation in this behaviour generates alternative foraging strategies. We find that natural C. elegans isolates differ in their sensitivity to the potent ascaroside icas#9 (IC-asc-C5). A quantitative trait locus (QTL) regulating icas#9 sensitivity includes srx-43, a G-protein-coupled icas#9 receptor that acts in the ASI class of sensory neurons to suppress exploration. Two ancient haplotypes associated with this QTL confer competitive growth advantages that depend on ascaroside secretion, its detection by srx-43 and the distribution of food. These results suggest that balancing selection at the srx-43 locus generates alternative density-dependent behaviours, fulfilling a prediction of foraging game theory.

  1. Reflectometry techniques for density profile measurements on fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Laviron, C. [Association Euratom-CEA, Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Donne, A.J.H. [Associatie Euratom-FOM, Nieuwegein (Netherlands). FOM-Instituut voor Plasmafysica; Manso, M.E. [Instituto Superior Tecnico, Lisbon (Portugal). Lab. de Quimica Organica; Sanchez, J. [EURATOM-CIEMAT for Fusion Association, Madrid (Spain)

    1996-03-01

    Reflectometry applied to the measurement of density profiles on fusion plasmas has been subject to many recent developments. After a brief reminder of the principles of reflectometry, the theoretical accuracy of reflectometry measurements is discussed. The main difficulties limiting the performance, namely the plasma fluctuations and the quality of the transmission lines, are analysed. The different techniques used for reflectometry are then presented. The present status and achievements of actual implementations of these techniques are shown, with an analysis of their respective limitations and merits, as well as foreseen developments. (author). 70 refs.

  2. THE DENSITY PROFILES OF MASSIVE, RELAXED GALAXY CLUSTERS. I. THE TOTAL DENSITY OVER THREE DECADES IN RADIUS

    Energy Technology Data Exchange (ETDEWEB)

    Newman, Andrew B.; Ellis, Richard S. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Treu, Tommaso; Sand, David J. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Nipoti, Carlo [Astronomy Department, University of Bologna, via Ranzani 1, I-40127 Bologna (Italy); Richard, Johan [CRAL, Observatorie de Lyon, Universite Lyon 1, 9 Avenue Ch. Andre, F-69561 Saint Genis Laval Cedex (France); Jullo, Eric, E-mail: anewman@astro.caltech.edu [Laboratoire d' Astrophysique de Marseille, Universite d' Aix-Marseille and CNRS, UMR7326, 38 rue F. Joliot-Curie, F-13388 Marseille Cedex 13 (France)

    2013-03-01

    Clusters of galaxies are excellent locations to probe the distribution of baryons and dark matter (DM) over a wide range of scales. We study a sample of seven massive (M {sub 200} = 0.4-2 Multiplication-Sign 10{sup 15} M {sub Sun }), relaxed galaxy clusters with centrally located brightest cluster galaxies (BCGs) at z = 0.2-0.3. Using the observational tools of strong and weak gravitational lensing, combined with resolved stellar kinematics within the BCG, we measure the total radial density profile, comprising both dark and baryonic matter, over scales of {approx_equal} 3-3000 kpc. We present Keck spectroscopy yielding seven new spectroscopic redshifts of multiply imaged sources and extended stellar velocity dispersion profiles of the BCGs. Lensing-derived mass profiles typically agree with independent X-ray estimates within {approx_equal} 15%, suggesting that departures from hydrostatic equilibrium are small and that the clusters in our sample (except A383) are not strongly elongated or compressed along the line of sight. The inner logarithmic slope {gamma}{sub tot} of the total density profile measured over r/r {sub 200} = 0.003-0.03, where {rho}{sub tot}{proportional_to}r{sup -{gamma}{sub t}{sub o}{sub t}}, is found to be nearly universal, with a mean ({gamma}{sub tot}) = 1.16 {+-} 0.05(random){sup +0.05} {sub -0.07} (systematic) and an intrinsic scatter {sigma}{sub {gamma}} < 0.13 (68% confidence). This is further supported by the very homogeneous shape of the observed velocity dispersion profiles, which are mutually consistent after a simple scaling. Remarkably, this slope agrees closely with high-resolution numerical simulations that contain only DM, despite the significant contribution of stellar mass on the scales we probe. The Navarro-Frenk-White profile characteristic of collisionless cold DM is a better description of the total mass density at radii {approx}> 5-10 kpc than that of DM alone. Hydrodynamical simulations that include baryons, cooling, and

  3. Computing 1-D atomic densities in macromolecular simulations: the Density Profile Tool for VMD

    OpenAIRE

    Giorgino, Toni

    2013-01-01

    Molecular dynamics simulations have a prominent role in biophysics and drug discovery due to the atomistic information they provide on the structure, energetics and dynamics of biomolecules. Specialized software packages are required to analyze simulated trajectories, either interactively or via scripts, to derive quantities of interest and provide insight for further experiments. This paper presents the Density Profile Tool, a package that enhances the Visual Molecular Dynamics environment w...

  4. Constraints on the halo density profile using HI flaring in the outer Galaxy

    CERN Document Server

    Narayan, C A; Jog, C J

    2005-01-01

    The observed flaring of HI disk in the outer region of galaxies has been used in the past to determine the shape of the dark matter halo. Previous studies based on this concept suggest a slightly oblate halo (axis ratio ~ 0.8) for our Galaxy. We reinvestigate this problem by calculating the HI scaleheight in the outer Galaxy to a larger radial distance, and by studying its dependence on the shape and the density profile of the halo. We find that a simple isothermal infinite halo of any shape- oblate or prolate, is not able to account for the observed flaring. Instead we show that a spherical halo with density falling faster than isothermal halo in the outer region provides a better fit to the observed HI flaring as well as the observed rotation curve of our Galaxy. These halos have about 95% of their mass within a few hundreds of kpc. For R_solar = 8.5 kpc and \\Theta_solar = 220 km/s, the central density and core radius can be constrained to the range \\rho_0 = 0.035 - 0.06 M_sun/pc^3 and R_c = 8 - 10 kpc. Our...

  5. Mathematical investigations of branch length similarity entropy profiles of shapes for various resolutions

    Science.gov (United States)

    Jeon, Wonju; Lee, Sang-Hee

    2012-12-01

    In our previous study, we defined the branch length similarity (BLS) entropy for a simple network consisting of a single node and numerous branches. As the first application of this entropy to characterize shapes, the BLS entropy profiles of 20 battle tank shapes were calculated from simple networks created by connecting pixels in the boundary of the shape. The profiles successfully characterized the tank shapes through a comparison of their BLS entropy profiles. Following the application, this entropy was used to characterize human's emotional faces, such as happiness and sad, and to measure the degree of complexity for termite tunnel networks. These applications indirectly indicate that the BLS entropy profile can be a useful tool to characterize networks and shapes. However, the ability of the BLS entropy in the characterization depends on the image resolution because the entropy is determined by the number of nodes for the boundary of a shape. Higher resolution means more nodes. If the entropy is to be widely used in the scientific community, the effect of the resolution on the entropy profile should be understood. In the present study, we mathematically investigated the BLS entropy profile of a shape with infinite resolution and numerically investigated the variation in the pattern of the entropy profile caused by changes in the resolution change in the case of finite resolution.

  6. Scattering length density profile of Ni film under controlled corrosion: A study in neutron reflectometry

    Indian Academy of Sciences (India)

    Surendra Singh; A K Poswal; S K Ghosh; Saibal Basu

    2008-11-01

    We report the density depth profile of an as-deposited Ni film and density profile for the same film after controlled electrochemical corrosion by chloride ions, measured by unpolarized neutron reflectometry. The neutron reflectometry measurement of the film after corrosion shows density degradation along the thickness of the film. The density profile as a function of depth, maps the growth of pitting and void networks due to corrosion. The profile after corrosion shows an interesting peaking nature.

  7. Computing 1-D atomic densities in macromolecular simulations: the Density Profile Tool for VMD

    CERN Document Server

    Giorgino, Toni

    2013-01-01

    Molecular dynamics simulations have a prominent role in biophysics and drug discovery due to the atomistic information they provide on the structure, energetics and dynamics of biomolecules. Specialized software packages are required to analyze simulated trajectories, either interactively or via scripts, to derive quantities of interest and provide insight for further experiments. This paper presents the Density Profile Tool, a package that enhances the Visual Molecular Dynamics environment with the ability to interactively compute and visualize 1-D projections of various density functions of molecular models. We describe how the plugin is used to perform computations both via a graphical interface and programmatically. Results are presented for realistic examples, all-atom bilayer models, showing how mass and electron densities readily provide measurements such as membrane thickness, location of structural elements, and how they compare to X-ray diffraction experiments.

  8. Shape effects on the random-packing density of tetrahedral particles.

    Science.gov (United States)

    Zhao, Jian; Li, Shuixiang; Jin, Weiwei; Zhou, Xuan

    2012-09-01

    Regular tetrahedra have been demonstrated recently giving high packing density in random configurations. However, it is unknown whether the random-packing density of tetrahedral particles with other shapes can reach an even higher value. A numerical investigation on the random packing of regular and irregular tetrahedral particles is carried out. Shape effects of rounded corner, eccentricity, and height on the packing density of tetrahedral particles are studied. Results show that altering the shape of tetrahedral particles by rounding corners and edges, by altering the height of one vertex, or by lateral displacement of one vertex above its opposite face, all individually have the effect of reducing the random-packing density. In general, the random-packing densities of irregular tetrahedral particles are lower than that of regular tetrahedra. The ideal regular tetrahedron should be the shape which has the highest random-packing density in the family of tetrahedra, or even among convex bodies. An empirical formula is proposed to describe the rounded corner effect on the packing density, and well explains the density deviation of tetrahedral particles with different roundness ratios. The particles in the simulations are verified to be randomly packed by studying the pair correlation functions, which are consistent with previous results. The spherotetrahedral particle model with the relaxation algorithm is effectively applied in the simulations.

  9. Robust functional statistics applied to Probability Density Function shape screening of sEMG data.

    Science.gov (United States)

    Boudaoud, S; Rix, H; Al Harrach, M; Marin, F

    2014-01-01

    Recent studies pointed out possible shape modifications of the Probability Density Function (PDF) of surface electromyographical (sEMG) data according to several contexts like fatigue and muscle force increase. Following this idea, criteria have been proposed to monitor these shape modifications mainly using High Order Statistics (HOS) parameters like skewness and kurtosis. In experimental conditions, these parameters are confronted with small sample size in the estimation process. This small sample size induces errors in the estimated HOS parameters restraining real-time and precise sEMG PDF shape monitoring. Recently, a functional formalism, the Core Shape Model (CSM), has been used to analyse shape modifications of PDF curves. In this work, taking inspiration from CSM method, robust functional statistics are proposed to emulate both skewness and kurtosis behaviors. These functional statistics combine both kernel density estimation and PDF shape distances to evaluate shape modifications even in presence of small sample size. Then, the proposed statistics are tested, using Monte Carlo simulations, on both normal and Log-normal PDFs that mimic observed sEMG PDF shape behavior during muscle contraction. According to the obtained results, the functional statistics seem to be more robust than HOS parameters to small sample size effect and more accurate in sEMG PDF shape screening applications.

  10. High Throughput Profiling of Molecular Shapes in Crystals

    Science.gov (United States)

    Spackman, Peter R.; Thomas, Sajesh P.; Jayatilaka, Dylan

    2016-02-01

    Molecular shape is important in both crystallisation and supramolecular assembly, yet its role is not completely understood. We present a computationally efficient scheme to describe and classify the molecular shapes in crystals. The method involves rotation invariant description of Hirshfeld surfaces in terms of of spherical harmonic functions. Hirshfeld surfaces represent the boundaries of a molecule in the crystalline environment, and are widely used to visualise and interpret crystalline interactions. The spherical harmonic description of molecular shapes are compared and classified by means of principal component analysis and cluster analysis. When applied to a series of metals, the method results in a clear classification based on their lattice type. When applied to around 300 crystal structures comprising of series of substituted benzenes, naphthalenes and phenylbenzamide it shows the capacity to classify structures based on chemical scaffolds, chemical isosterism, and conformational similarity. The computational efficiency of the method is demonstrated with an application to over 14 thousand crystal structures. High throughput screening of molecular shapes and interaction surfaces in the Cambridge Structural Database (CSD) using this method has direct applications in drug discovery, supramolecular chemistry and materials design.

  11. Real-time identification of the current density profile in the JET Tokamak: method and validation

    CERN Document Server

    Mazon, Didier; Boulbe, Cédric; Faugeras, Blaise; Boboc, A; Brix, M; De Vries, P; Sharapov, S; Zabeo, L

    2009-01-01

    The real-time reconstruction of the plasma magnetic equilibrium in a Tokamak is a key point to access high performance regimes. Indeed, the shape of the plasma current density profile is a direct output of the reconstruction and has a leading effect for reaching a steady-state high performance regime of operation. In this paper we present the methodology followed to identify numerically the plasma current density in a Tokamak and its equilibrium. In order to meet the real-time requirements a C++ software has been developed using the combination of a finite element method, a nonlinear fixed point algorithm associated to a least square optimization procedure. The experimental measurements that enable the identification are the magnetics on the vacuum vessel, the interferometric and polarimetric measurements on several chords and the motional Stark effect. Details are given about the validation of the reconstruction on the JET tokamak, either by comparison with ?off-line' equilibrium codes or real time software ...

  12. Density profile of nitrogen in cylindrical pores of MCM-41

    Science.gov (United States)

    Soper, Alan K.; Bowron, Daniel T.

    2017-09-01

    A straightforward approach using radiation scattering (X-ray or neutron) combined with atomistic modelling is used to accurately assess the pore dimensions in the porous silica, MCM-41. The method is used to calculate the density profile of nitrogen absorbed in this material at a variety of fractional pressures, p/p0, where p0 is the saturated vapour pressure, up to p/p0 = 0.36 at T = 87 K in the present instance. At this pressure two distinct layers of liquid nitrogen occur on the silica surface, with a relatively sharp gas-liquid interface. It is suggested surface tension effects at this interface strongly influence the growth of further layers.

  13. Column Density Profiles of Multi-Phase Gaseous Halos

    CERN Document Server

    Liang, Cameron J; Agertz, Oscar

    2015-01-01

    We present a suite of high-resolution cosmological galaxy re-simulations of a Milky-Way size halo with variety of star-formation and feedback models to investigate the effects of the specific details of the star formation-feedback loop modeling on the observable properties of the circumgalactic medium (CGM). We show that properties of the CGM are quite sensitive to the details of star formation-feedback loop. The simulation which produces a very realistic late-type central galaxy fails to reproduce existing observations of CGM. At the same time, variations of parameters of star formation recipe or feedback modeling, such as cosmic rays feedback, brings predicted CGM in better agreement with observations. The simulations show that the column density profiles of ions arising in such gas are well described by an exponential function of the impact parameter. Ions with higher ionization energy have more extended profiles with the scale height of the exponential distribution scaling as a power law of the ionization...

  14. Assessment studies on the inversion of satellite to satellite electron content to obtain electron density profiles in the ionosphere

    CERN Document Server

    Hochegger, G P

    2000-01-01

    The electron content data, obtained by satellite-to-satellite occultations of radio signals can lead to height profiles of electron density by discrete inversion. Since there is no possibility to verify such profiles by means of other measurements (practically never measurements at the same time and same location) it was necessary to simulate occultation scenarios by means of an ionosphere model to obtain a large number of comparisons sufficient for investigations on a statistical basis. The obtained electron contents were inverted and compared with electron density height profiles, obtained with the same ionospheric model for the occultation point. The differences between these profiles were investigated (difference between the F2-peak maxima, the height of the maxima, the shape of the topside and bottom side ionosphere). Since simulations were done for chosen locations (250 randomly spread on the globe) for every month and every second hour and for two solar activity levels (HSA and LSA), a whole year was '...

  15. Global analysis of quadrupole shape invariants based on covariant energy density functionals

    Science.gov (United States)

    Quan, S.; Chen, Q.; Li, Z. P.; Nikšić, T.; Vretenar, D.

    2017-05-01

    Background: The coexistence of different geometric shapes at low energies presents a universal structure phenomenon that occurs over the entire chart of nuclides. Studies of the shape coexistence are important for understanding the microscopic origin of collectivity and modifications of shell structure in exotic nuclei far from stability. Purpose: The aim of this work is to provide a systematic analysis of characteristic signatures of coexisting nuclear shapes in different mass regions, using a global self-consistent theoretical method based on universal energy density functionals and the quadrupole collective model. Method: The low-energy excitation spectrum and quadrupole shape invariants of the two lowest 0+ states of even-even nuclei are obtained as solutions of a five-dimensional collective Hamiltonian (5DCH) model, with parameters determined by constrained self-consistent mean-field calculations based on the relativistic energy density functional PC-PK1, and a finite-range pairing interaction. Results: The theoretical excitation energies of the states, 21+,41+,02+,22+,23+, as well as the B (E 2 ;01+→21+) values, are in very good agreement with the corresponding experimental values for 621 even-even nuclei. Quadrupole shape invariants have been implemented to investigate shape coexistence, and the distribution of possible shape-coexisting nuclei is consistent with results obtained in recent theoretical studies and available data. Conclusions: The present analysis has shown that, when based on a universal and consistent microscopic framework of nuclear density functionals, shape invariants provide distinct indicators and reliable predictions for the occurrence of low-energy coexisting shapes. This method is particularly useful for studies of shape coexistence in regions far from stability where few data are available.

  16. Radiation-damped profiles of extremely high column density neutral hydrogen: implications of cosmic reionization

    Science.gov (United States)

    Bach, Kiehunn

    2017-01-01

    Incorporating the time-dependent second-order perturbation theory for the Lyman scattering cross-section, we investigate the intergalactic absorption profiles of extremely high column density systems near the end of cosmic reionization. Assuming a representative set of the redshift distribution of neutral hydrogen, we quantitatively examined the impact of inhomogeneous density on the intrinsic absorption profiles. The cumulative absorption by neutral patches in the line of sight mainly affects the far off-centre region of the red damping wing, but the effect is not significant. The shape of the line centre can be modified by the near-zone distribution due to high opacities of the near-resonance scattering. On the other hand, the HWHM (half width at half-maximum) as an effective line width is relatively less sensitive to the local inhomogeneity. Specifically, when the two local damping wings of Lyα and Lyβ are close in spectra of the strongly damped systems, accurate profiles of both lines are required. In the case of N_{H I}≲ 10^{21} { cm^{-2}}, the two-level approximation is marginally applicable for the damping wing fit within 5 - 7 per cent errors. However, as the local column density reaches N_{H I}˜ 10^{22.3} { cm^{-2}}, this classical approximation yields a relative error of a 10 per cent overestimation in the red wing and a 20 per cent underestimation in the blue wing of Lyα. If severe extinction by the Lyα forests is carefully subtracted, the intrinsic absorption profile will provide a better constraint on the local ionized states. For practical applications, an analytic fitting function for the Lyβ scattering is derived.

  17. Radiation Damped Profiles of Extremely High Column Density Neutral Hydrogen : Implications of Cosmic Reionization

    Science.gov (United States)

    Bach, Kiehunn

    2016-09-01

    Incorporating the time-dependent second-order perturbation theory for the Lyman scattering cross-section, we investigate the intergalactic absorption profiles of extremely high column density systems near the end of cosmic reionization. Assuming a representative set of the redshift distribution of neutral hydrogen, we quantitatively examined the impact of inhomogeneous density on the intrinsic absorption profiles. The cumulative absorption by neutral patches in the line-of-sight mainly affects the far off-center region of the red damping wing, but the effect is not significant. The shape of the line-center can be modified by the near-zone distribution due to high opacities of the near-resonance scattering. On the other hand, the HWHM (half width at half maximum) as an effective line-width is relatively less sensitive to the local inhomogeneity. Specifically, when the two local damping wings of Lyα and Lyβ are close in spectra of the strongly damped systems, accurate profiles of both lines are required. In the case of N HI ≲ 1021 cm-2, the two-level approximation is marginally applicable for the damping wing fit within 5 - 7% errors. However, as the local column density reaches N HI ˜ 1022.3 cm-2, this classical approximation yields a relative error of a 10% overestimation in the red wing and a 20% underestimation in the blue wing of Lyα. If severe extinction by the Lyα forests is carefully subtracted, the intrinsic absorption profile will provide a better constraint on the local ionized states. For practical applications, an analytic fitting function for the Lyβ scattering is derived.

  18. Recent results on current profile shaping on tore supra

    Energy Technology Data Exchange (ETDEWEB)

    Becoulet, A.

    1994-12-31

    The link between the current profile and the confinement is studied, involving various regimes: high power minority ion cyclotron resonant heating, high power lower hybrid current drive, fast wave direct electron heating and current drive and pellet enhanced performance. It is shown that the electron heat diffusivity decreases when the magnetic shear increases in the confinement zone and/or when it decreases in the plasma centre. (authors). 13 refs., 6 figs.

  19. ASSESSMENT OF BACTERIAL BIOSURFACTANT PRODUCTION THROUGH AXISYMMETRICAL DROP SHAPE-ANALYSIS BY PROFILE

    NARCIS (Netherlands)

    VANDERVEGT, W; VANDERMEI, HC; BUSSCHER, HJ

    1991-01-01

    Axisymmetric drop shape analysis by profile (ADSA-P) is a technique developed in colloid and surface science to simultaneously determine the contact angle and liquid surface tension from the profile of a droplet resting on a solid surface. In this paper is described how ADSA-P can be employed to ass

  20. Line Shape Modeling for the Diagnostic of the Electron Density in a Corona Discharge

    Directory of Open Access Journals (Sweden)

    Joël Rosato

    2017-09-01

    Full Text Available We present an analysis of spectra observed in a corona discharge designed for the study of dielectrics in electrical engineering. The medium is a gas of helium and the discharge was performed at the vicinity of a tip electrode under high voltage. The shape of helium lines is dominated by the Stark broadening due to the plasma microfield. Using a computer simulation method, we examine the sensitivity of the He 492 nm line shape to the electron density. Our results indicate the possibility of a density diagnostic based on passive spectroscopy. The influence of collisional broadening due to interactions between the emitters and neutrals is discussed.

  1. Engineering ferroelectric tunnel junctions through potential profile shaping

    Energy Technology Data Exchange (ETDEWEB)

    Boyn, S.; Garcia, V., E-mail: vincent.garcia@thalesgroup.com; Fusil, S.; Carrétéro, C.; Garcia, K.; Collin, S.; Deranlot, C.; Bibes, M.; Barthélémy, A. [Unité Mixte de Physique CNRS/Thales, 1 Av. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay (France); Xavier, S. [Thales Research and Technology, 1 Av. Fresnel, 91767 Palaiseau (France)

    2015-06-01

    We explore the influence of the top electrode materials (W, Co, Ni, Ir) on the electronic band profile in ferroelectric tunnel junctions based on super-tetragonal BiFeO{sub 3}. Large variations of the transport properties are observed at room temperature. In particular, the analysis of current vs. voltage curves by a direct tunneling model indicates that the metal/ferroelectric interfacial barrier height increases with the top-electrode work function. While larger metal work functions result in larger OFF/ON ratios, they also produce a large internal electric field which results in large and potentially destructive switching voltages.

  2. Engineering ferroelectric tunnel junctions through potential profile shaping

    Directory of Open Access Journals (Sweden)

    S. Boyn

    2015-06-01

    Full Text Available We explore the influence of the top electrode materials (W, Co, Ni, Ir on the electronic band profile in ferroelectric tunnel junctions based on super-tetragonal BiFeO3. Large variations of the transport properties are observed at room temperature. In particular, the analysis of current vs. voltage curves by a direct tunneling model indicates that the metal/ferroelectric interfacial barrier height increases with the top-electrode work function. While larger metal work functions result in larger OFF/ON ratios, they also produce a large internal electric field which results in large and potentially destructive switching voltages.

  3. Behavioural profiles are shaped by social experience: when, how and why.

    Science.gov (United States)

    Sachser, Norbert; Kaiser, Sylvia; Hennessy, Michael B

    2013-05-19

    The comprehensive understanding of individual variation in behavioural profiles is a current and timely topic not only in behavioural ecology, but also in biopsychological and biomedical research. This study focuses on the shaping of behavioural profiles by the social environment in mammals. We review evidence that the shaping of behavioural profiles occurs from the prenatal phase through adolescence and beyond. We focus specifically on adolescence, a sensitive phase during which environmental stimuli have distinctive effects on the modulation of behavioural profiles. We discuss causation, in particular, how behavioural profiles are shaped by social stimuli through behavioural and neuroendocrine processes. We postulate a central role for maternal hormones during the prenatal phase, for maternal behaviour during lactation and for the interaction of testosterone and stress hormones during adolescence. We refer to evolutionary history and attempt to place developmental shaping into broader evolutionary historical trends. Finally, we address survival value. We argue that the shaping of behavioural profiles by environmental stimuli from the prenatal phase through adolescence represents an effective mechanism for repeated and rapid adaptation during the lifetime. Notably, the adolescent phase may provide a last chance for correction if the future environment deviates from that predicted in earlier phases.

  4. Optimal shape profiles for cooling fins of high and low conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Bobaru, Florin; Rachakonda, Srinivas [Nebraska Univ., Dept. of Engineering Mechanics, Lincoln, NE (United States)

    2004-11-01

    We present a numerical approach able to capture the dependence of the optimal shape profiles of thermal fins on the conductivity parameters. We consider the two-dimensional cross-section of a periodic array of fins and involve the third dimension via the thermal boundary layer. The highly conductive fins converge to 'sharp-pointed', narrow base shapes while the low conductivity ones prefer blunted, wide base fins. The optimal shapes we obtain are similar to the shapes of intestinal villi and stegosaurus plates. A meshfree method, coupled with a gradient-based optimization algorithm, is used to handle the significant shape changes from a simple, generic initial guess to the final, optimal shape. We reach the optimal shapes without remeshing. (Author)

  5. Cell Shape and Cardiosphere Differentiation: A Revelation by Proteomic Profiling

    Directory of Open Access Journals (Sweden)

    Nanako Kawaguchi

    2013-01-01

    Full Text Available Stem cells (embryonic stem cells, somatic stem cells such as neural stem cells, and cardiac stem cells and cancer cells are known to aggregate and form spheroid structures. This behavior is common in undifferentiated cells and may be necessary for adapting to certain conditions such as low-oxygen levels or to maintain undifferentiated status in microenvironments including stem cell niches. In order to decipher the meaning of this spheroid structure, we established a cardiosphere clone (CSC-21E derived from the rat heart which can switch its morphology between spheroid and nonspheroid. Two forms, floating cardiospheres and dish-attached flat cells, could be switched reversibly by changing the cell culture condition. We performed differential proteome analysis studies and obtained protein profiles distinct between spherical forms and flat cells. From protein profiling analysis, we found upregulation of glycolytic enzymes in spheroids with some stress proteins switched in expression levels between these two forms. Evidence has been accumulating that certain chaperone/stress proteins are upregulated in concert with cellular changes including proliferation and differentiation. We would like to discuss the possible mechanism of how these aggregates affect cell differentiation and/or other cellular functions.

  6. Different Flavonoids Can Shape Unique Gut Microbiota Profile In Vitro.

    Science.gov (United States)

    Huang, Jiacheng; Chen, Long; Xue, Bin; Liu, Qianyue; Ou, Shiyi; Wang, Yong; Peng, Xichun

    2016-09-01

    The impact of flavonoids has been discussed on the relative viability of bacterial groups in human microbiota. This study was aimed to compare the modulation of various flavonoids, including quercetin, catechin and puerarin, on gut microbiota culture in vitro, and analyze the interactions between bacterial species using fructo-oligosaccharide (FOS) as carbon source under the stress of flavonoids. Three plant flavonoids, quercetin, catechin, and puerarin, were added into multispecies culture to ferment for 24 h, respectively. The bacterial 16S rDNA amplicons were sequenced, and the composition of microbiota community was analyzed. The results revealed that the tested flavonoids, quercetin, catechin, and puerarin, presented different activities of regulating gut microbiota; flavonoid aglycones, but not glycosides, may inhibit growth of certain species. Quercetin and catechin shaped unique biological webs. Bifidobacterium spp. was the center of the biological web constructed in this study.

  7. Anti-Viral Antibody Profiling by High Density Protein Arrays

    Science.gov (United States)

    Bian, Xiaofang; Wiktor, Peter; Kahn, Peter; Brunner, Al; Khela, Amritpal; Karthikeyan, Kailash; Barker, Kristi; Yu, Xiaobo; Magee, Mitch; Wasserfall, Clive H.; Gibson, David; Rooney, Madeleine E; Qiu, Ji; LaBaer, Joshua

    2015-01-01

    Viral infections elicit anti-viral antibodies and have been associated with various chronic diseases. Detection of these antibodies can facilitate diagnosis, treatment of infection and understanding of the mechanisms of virus associated diseases. In this work, we assayed anti-viral antibodies using a novel high density-nucleic acid programmable protein array (HD-NAPPA) platform. Individual viral proteins were expressed in situ directly from plasmids encoding proteins in an array of microscopic reaction chambers. Quality of protein display and serum response was assured by comparing intra- and inter- array correlation within or between printing batches with average correlation coefficients of 0.91 and 0.96, respectively. HD-NAPPA showed higher signal to background (S/B) ratio compared with standard NAPPA on planar glass slides and ELISA. Antibody responses to 761 antigens from 25 different viruses were profiled among patients with juvenile idiopathic arthritis (JIA) and type 1 diabetes (T1D). Common as well as unique antibody reactivity patterns were detected between patients and healthy controls. We believe HD-viral-NAPPA will enable the study of host-pathogen interactions at unprecedented dimensions and elucidate the role of pathogen infections in disease development. PMID:25758251

  8. Evolution of Characteristic Quantities for Dark Matter Halo Density Profiles

    CERN Document Server

    Romano-Diaz, E; Heller, C; Faltenbacher, A; Jones, D; Shlosman, I; Romano-Diaz, Emilio; Hoffman, Yehuda; Heller, Clayton; Faltenbacher, Andreas; Jones, Daniel; Shlosman, Isaac

    2006-01-01

    We investigate the effect of an assembly history on the evolution of dark matter (DM) halos of 10^{12} Msun/h using Constrained Realizations of random Gaussian fields. Five different realizations of a DM halo with distinct merging histories were constructed and evolved. Our main results are: A halo evolves via a sequence of quiescent phases of a slow mass accretion intermitted by violent episodes of major mergers. In the quiescent phases, the density is well fitted by an NFW profile, the inner scale radius Rs and the mass enclosed within it remain constant, and the virial radius (Rvir) grows linearly with the expansion parameter "a". Within each quiescent phase the concentration parameter ("c") scales as "a", and the mass accretion history (Mvir) is well described by the Tasitsiomi etal. fitting formula. In the violent phases the halos are not in a virial equilibrium and both Rs and Rvir grow discontinuously. The violent episodes drive the halos from one NFW dynamical equilibrium to another. The final structu...

  9. Measuring protoplanetary disk gas surface density profiles with ALMA

    CERN Document Server

    McPartland, Jonathan P Williams Conor

    2016-01-01

    The gas and dust are spatially segregated in protoplanetary disks due to the vertical settling and radial drift of large grains. A fuller accounting of the mass content and distribution in disks therefore requires spectral line observations. We extend the modeling approach presented in Williams & Best (2014) to show that gas surface density profiles can be measured from high fidelity 13CO integrated intensity images. We demonstrate the methodology by fitting ALMA observations of the HD 163296 disk to determine a gas mass, Mgas = 0.048 solar masse, and accretion disk characteristic size Rc = 213au and gradient gamma = 0.39. The same parameters match the C18O 2--1 image and indicates an abundance ratio [13CO]/[C18O] of 700 independent of radius. To test how well this methodology can be applied to future line surveys of smaller, lower mass T Tauri disks, we create a large 13CO 2--1 image library and fit simulated data. For disks with gas masses 3-10 Jupiter masses at 150pc, ALMA observations with a resolutio...

  10. Shape evolutions of $^{72,74}$Kr with temperature in the covariant density functional theory

    CERN Document Server

    Zhang, Wei

    2016-01-01

    The rich phenomena of deformations in neutron-deficient krypton isotopes such as the shape evolution with neutron number and the shape coexistence attract the interests of nuclear physicists for decades. It will be interesting to study such shape phenomena using a novel way, i.e., by thermally exciting the nucleus. So in this work, we study the shape evolutions in $^{72,74}$Kr with increasing temperatures within the covariant density functional theory with parameter set PC-PK1. While $^{72}$Kr displays simple oblate to spherical transition at $T$=3.35 MeV, $^{74}$Kr displays three shape transitions, namely, 0.6 MeV from oblate to prolate, 1.65 MeV from prolate to oblate, and 2.95 MeV from oblate to spherical. Together with the shape transitions, two shape coexistence ranges are obtained for $^{74}$Kr, namely, from 0 MeV to 0.75 MeV, and from 1.45 to 1.8 MeV. Such shape transitions can be understood by disintegrating the total energy into particle energy and field energy.

  11. CO{sub 2} laser diagnostics for measurements of the plasma density profile and plasma density fluctuations on LHD

    Energy Technology Data Exchange (ETDEWEB)

    Vyacheslavov, L.N. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation); Tanaka, K.; Kawahata, K. [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2001-04-01

    A CO{sub 2} laser based diagnostics complimentary to the existing FIR interferometer is proposed. It combines interferometry for plasma density profile measurement under conditions of large density gradients, and both imaging and scattering techniques for observation of plasma fluctuations. Two-colour interferometer with a slablike probe beam and a single multichannel linear detector array provide observation of plasma density profile and density fluctuations at two locations along the probe beam. Basic characteristics of the diagnostics are considered as well as some effects that include dispersion and are critical for two colour imaging technique. The results of the bench-top experiments with the prototype of the interferometer are presented. (author)

  12. In-situ piezoresponse force microscopy cantilever mode shape profiling

    Energy Technology Data Exchange (ETDEWEB)

    Proksch, R., E-mail: roger.proksch@oxinst.com [Asylum Research, an Oxford Instruments Company, Santa Barbara, California 93117 (United States)

    2015-08-21

    The frequency-dependent amplitude and phase in piezoresponse force microscopy (PFM) measurements are shown to be a consequence of the Euler-Bernoulli (EB) dynamics of atomic force microscope (AFM) cantilever beams used to make the measurements. Changes in the cantilever mode shape as a function of changes in the boundary conditions determine the sensitivity of cantilevers to forces between the tip and the sample. Conventional PFM and AFM measurements are made with the motion of the cantilever measured at one optical beam detector (OBD) spot location. A single OBD spot location provides a limited picture of the total cantilever motion, and in fact, experimentally observed cantilever amplitude and phase are shown to be strongly dependent on the OBD spot position for many measurements. In this work, the commonly observed frequency dependence of PFM response is explained through experimental measurements and analytic theoretical EB modeling of the PFM response as a function of both frequency and OBD spot location on a periodically poled lithium niobate sample. One notable conclusion is that a common choice of OBD spot location—at or near the tip of the cantilever—is particularly vulnerable to frequency dependent amplitude and phase variations stemming from dynamics of the cantilever sensor rather than from the piezoresponse of the sample.

  13. Role of Density Profiles for the Nonlinear Propagation of Intense Laser Beam through Plasma Channel

    OpenAIRE

    Sonu Sen; Meenu Asthana Varshney; Dinesh Varshney

    2014-01-01

    In this work role of density profiles for the nonlinear propagation of intense laser beam through plasma channel is analyzed. By employing the expression for the dielectric function of different density profile plasma, a differential equation for beamwidth parameter is derived under WKB and paraxial approximation. The laser induces modifications of the dielectric function through nonlinearities. It is found that density profiles play vital role in laser-plasma interaction studies. To have num...

  14. How AGN feedback and metal cooling shape cluster entropy profiles

    CERN Document Server

    Dubois, Yohan; Teyssier, Romain; Slyz, Adrianne

    2011-01-01

    Observed clusters of galaxies essentially come in two flavors: non cool core clusters characterized by an isothermal temperature profile and a central entropy floor, and cool-core clusters where temperature and entropy in the central region are increasing with radius. Using cosmological resimulations of a galaxy cluster, we study the evolution of its intracluster medium (ICM) gas properties, and through them we assess the effect of different (sub-grid) modelling of the physical processes at play, namely gas cooling, star formation, feedback from supernovae and active galactic nuclei (AGN). More specifically we show that AGN feedback plays a major role in the pre-heating of the proto-cluster as it prevents a high concentration of mass from collecting in the center of the future galaxy cluster at early times. However, AGN activity during the cluster's later evolution is also required to regulate the mass flow into its core and prevent runaway star formation in the central galaxy. Whereas the energy deposited by...

  15. Flat Central Density Profile and Constant DM Surface Density in Galaxies from Scalar Field Dark Matter

    CERN Document Server

    Robles, Victor H

    2012-01-01

    The scalar field dark matter (SFDM) model proposes that galaxies form by condensation of a scalar field (SF) very early in the universe forming Bose-Einstein Condensates (BEC) drops, i.e., in this model haloes of galaxies are gigantic drops of SF. Here big structures form like in the LCDM model, by hierarchy, thus all the predictions of the LCDM model at big scales are reproduced by SFDM. This model predicts that all galaxies must be very similar and exist for bigger redshifts than in the LCDM model. In this work we show that BEC dark matter haloes fit high-resolution rotation curves of a sample of thirteen low surface brightness galaxies. We compare our fits to those obtained using a Navarro-Frenk-White and Pseudo-Isothermal (PI) profiles and found a better agreement with the SFDM and PI profiles. The mean value of the logarithmic inner density slopes is -0.27 +/- 0.18. As a second result we find a natural way to define the core radius with the advantage of being model-independent. Using this new definition ...

  16. Microbial community dynamics in soil aggregates shape biogeochemical gas fluxes from soil profiles

    Science.gov (United States)

    Ebrahimi, Ali; Or, Dani

    2016-04-01

    Microbial communities inhabiting soil aggregates dynamically adjust their activity and composition in response to variations in hydration and other external conditions. These rapid dynamics shape signatures of biogeochemical activity and gas fluxes emitted from soil profiles. Mechanistic models of microbial processes in unsaturated aggregate pore networks revealed dynamic interplay between oxic and anoxic microsites that are jointly shaped by hydration and by aerobic and anaerobic microbial communities. The spatial extent of anoxic niches (hotspots) flicker in time (hot moments) and support significant anaerobic microbial activity even in aerated soil profiles. We employed an individual-based model for microbial community life in soil aggregate assemblies represented by 3-D angular pore networks with profiles of water, carbon, and oxygen that vary with soil depth as boundary conditions. The study integrates microbial activity within aggregates of different sizes and soil depth to obtain biogeochemical fluxes over the soil profile. The results quantify impacts of dynamic shifts in microbial community composition on CO2 and N2O production rates in soil profiles in good agreement with experimental data. Aggregate size distribution and the shape of resource profiles in a soil determine how hydration dynamics shape denitrification and carbon utilization rates. Results from the mechanistic model for microbial activity in aggregates of different sizes were used to derive parameters for analytical representation of soil biogeochemical processes across large scales of interest for hydrological and climate models.

  17. Tidal stirring of satellites with shallow density profiles prevents them from being too big to fail

    CERN Document Server

    Tomozeiu, Mihai; Quinn, Thomas

    2016-01-01

    The "too big to fail" problem is revisited by studying the tidal evolution of populations of dwarf satellites with different density profiles. The high resolution cosmological $\\rm \\Lambda CDM$ "ErisMod" set of simulations is used. These simulations can model both the stellar and dark matter components of the satellites, and their evolution under the action of the tides of a MW-sized host halo at a force resolution better than 10 pc. The stronger tidal mass loss and re-shaping of the mass distribution induced in satellites with $\\gamma=0.6$ dark matter density distributions, as those resulting from the effect of feedback in hydrodynamical simulations of dwarf galaxy formation, is sufficient to bring the circular velocity profiles in agreement with the kinematics of MW's dSphs. In contrast, in simulations in which the satellites retain cusps at $z=0$ there are several "massive failures" with circular velocities in excess of the observational constraints. Various sources of deviations in the conventionally adop...

  18. Multidimensionally constrained covariant density functional theories—nuclear shapes and potential energy surfaces

    Science.gov (United States)

    Zhou, Shan-Gui

    2016-06-01

    The intrinsic nuclear shapes deviating from a sphere not only manifest themselves in nuclear collective states but also play important roles in determining nuclear potential energy surfaces (PES’s) and fission barriers. In order to describe microscopically and self-consistently nuclear shapes and PES’s with as many shape degrees of freedom as possible included, we developed multidimensionally constrained covariant density functional theories (MDC-CDFTs). In MDC-CDFTs, the axial symmetry and the reflection symmetry are both broken and all deformations characterized by {β }λ μ with even μ are considered. We have used the MDC-CDFTs to study PES’s and fission barriers of actinides, the non-axial octupole Y 32 correlations in N = 150 isotones and shapes of hypernuclei. In this Review we will give briefly the formalism of MDC-CDFTs and present the applications to normal nuclei.

  19. Ultra Low Density Shape Memory Polymer Foams With Tunable Physicochemical Properties for Treatment of intracranial Aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Singhal, Pooja [Texas A & M Univ., College Station, TX (United States)

    2013-12-01

    Shape memory polymers (SMPs) are a rapidly emerging class of smart materials that can be stored in a deformed temporary shape, and can actively return to their original shape upon application of an external stimulus such as heat, pH or light. This behavior is particularly advantageous for minimally invasive biomedical applications comprising embolic/regenerative scaffolds, as it enables a transcatheter delivery of the device to the target site. The focus of this work was to exploit this shape memory behavior of polyurethanes, and develop an efficient embolic SMP foam device for the treatment of intracranial aneurysms.In summary, this work reports a novel family of ultra low density polymer foams which can be delivered via a minimally invasive surgery to the aneurysm site, actuated in a controlled manner to efficiently embolize the aneurysm while promoting physiological fluid/blood flow through the reticulated/open porous structure, and eventually biodegrade leading to complete healing of the vasculature.

  20. Multidimensionally-constrained covariant density functional theories --- nuclear shapes and potential energy surfaces

    CERN Document Server

    Zhou, Shan-Gui

    2016-01-01

    The intrinsic nuclear shapes deviating from a sphere not only manifest themselves in nuclear collective states but also play important roles in determining nuclear potential energy surfaces (PES's) and fission barriers. In order to describe microscopically and self-consistently nuclear shapes and PES's with as many shape degrees of freedom as possible included, we developed multidimensionally-constrained covariant density functional theories (MDC-CDFTs). In MDC-CDFTs, the axial symmetry and the reflection symmetry are both broken and all deformations characterized by $\\beta_{\\lambda\\mu}$ with even $\\mu$ are considered. We have used the MDC-CDFTs to study PES's and fission barriers of actinides, the non-axial octupole $Y_{32}$ correlations in $N = 150$ isotones and shapes of hypernuclei. In this Review we will give briefly the formalism of MDC-CDFTs and present the applications to normal nuclei.

  1. The late-type stellar density profile in the Galactic Center: A statistical approach

    CERN Document Server

    Chappell, Samantha N; Do, Tuan; Martinez, Gregory D; Yelda, Sylvana; Sitarski, Breann N; Lu, Jessica R; Morris, Mark R

    2016-01-01

    The late-type stellar population in the Galactic Center was first predicted to reside in a dynamically relaxed cusp (power law slope ranging from 3/2 to 7/4). However, observations - which rely on models to correct for projection effects - have suggested a flat distribution instead. The need for this correction is due to the lack of information regarding the line-of-sight distances. With a two decade long baseline in astrometric measurements, we are now able to measure significant projected radial accelerations, six of which are newly reported here, that directly constrain line-of-sight distances. Here we present a statistical approach to take advantage of this information and more accurately constrain the shape of the radial density profile of the late-type stellar population in the Galactic Center.

  2. Random River Fluctuations Shape the Root Profile of Riparian Plants

    Science.gov (United States)

    Perona, P.; Tron, S.; Gorla, L.; Schwarz, M.; Laio, F.; Ridolfi, L.

    2015-12-01

    Plant roots are recognized to play a key role in the riparian ecosystems: they contribute to the plant as well as to the streambank and bedforms stability, help to enhance the water quality of the river, and sustain the belowground biodiversity. The complexity of the root-system architecture recalls their remarkable ability to respond to environmental conditions, notably including soil heterogeneity, resource availability, and climate. In fluvial environments where nutrient availability is not a limiting factor for plant to grow, the root growth of phreatophytic plants is strongly influenced by water and oxygen availability in the soil. In this work, we demonstrate that the randomness of water table fluctuations, determined by streamflow stochastic variability, is likely to be the main driver for the root development strategy of riparian plants. A collection of root measurements from field and outdoor controlled experiments is used to demonstrate that the vertical root density distribution can be described by a simple analytical expression, whose parameters are linked to properties of soil, plant and water table fluctuations. This physically-based expression is able to predict riparian plant roots adaptability to different hydrological and pedologic scenarios in riverine environments. Hence, this model has great potential towards the comprehension of the effects of future climate and environmental changing conditions on plant adaptation and river ecomorphodynamic processes. Finally, we present an open access graphical user interface that we developed in order to estimate the vertical root distribution in fluvial environments and to make the model easily available to a wider scientific and professional audience.

  3. Density profiles of galaxy groups and clusters from SDSS galaxy-galaxy weak lensing

    CERN Document Server

    Mandelbaum, R; Cool, R J; Blanton, M; Hirata, C M; Brinkmann, J; Mandelbaum, Rachel; Seljak, Uros; Cool, Richard J.; Blanton, Michael; Hirata, Christopher M.; Brinkmann, Jonathan

    2006-01-01

    We present results of a measurement of the shape of the density profile of galaxy groups and clusters traced by 43 335 Luminous Red Galaxies (LRGs) with spectroscopic redshifts from the Sloan Digital Sky Survey (SDSS). The galaxies are selected such that they are the brightest within a cylindrical aperture, split into two luminosity samples, and modeled as the sum of stellar and dark matter components. We present a detailed investigation of many possible systematic effects that could contaminate our signal and develop methods to remove them, including a detected intrinsic alignment for galaxies within 100 kpc/h of LRGs which we remove using photometric redshift information. The resulting lensing signal is consistent with NFW profile dark matter halos; the SIS profile is ruled out at the 96 (conservatively) and 99.96 per cent confidence level (CL) for the fainter and brighter lens samples (respectively) when we fit using lensing data between 40 kpc/h and 2 Mpc/h with total signal-to-noise of 19 and 25 for the ...

  4. Demonstration of Current Profile Shaping using Double Dog-Leg Emittance Exchange Beam Line at Argonne Wakefield Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Gwanghui [Argonne, HEP; Cho, Moo-Hyun [POSTECH; Conde, Manoel [Argonne, HEP; Doran, Darrell [Argonne, HEP; Gai, Wei [Argonne, HEP; Jing, Chunguang [Euclid Techlabs, Solon; Kim, Kwang-Je [Argonne, HEP; Liu, Wanming [Argonne, HEP; Namkung, Won [POSTECH; Piot, Philippe [Northern Illinois U.; Power, John [Argonne, HEP; Sun, Yin-E [Argonne, HEP; Whiteford, Charles [Argonne, HEP; Wisniewski, Eric [Argonne, HEP; Zholents, Alexander [Argonne, HEP

    2016-06-01

    Emittance exchange (EEX) based longitudinal current profile shaping is the one of the promising current profile shaping technique. This method can generate high quality arbitrary current profiles under the ideal conditions. The double dog-leg EEX beam line was recently installed at the Argonne Wakefield Accelerator (AWA) to explore the shaping capability and confirm the quality of this method. To demonstrate the arbitrary current profile generation, several different transverse masks are applied to generate different final current profiles. The phase space slopes and the charge of incoming beam are varied to observe and suppress the aberrations on the ideal profile. We present current profile shaping results, aberrations on the shaped profile, and its suppression.

  5. Ground-State Density Profiles of One-Dimensional Bose Gases with Anisotropic Transversal Confinement

    Institute of Scientific and Technical Information of China (English)

    HAO Ya-Jiang

    2011-01-01

    We investigate the ground-state density distributions of interacting one-dimensional Bose gases with anisotropic transversal confinement.Combining the exact ground state energy density of homogeneous bose gases with local density approximation,we determine the density distribution in each interacting regime for different anisotropic parameters.It is shown that the transversal anisotropic parameter changes the density distribution obviously,and the observed density profiles on each orientation exhibit a difference of a factor.

  6. Testing and Estimating Shape-Constrained Nonparametric Density and Regression in the Presence of Measurement Error

    KAUST Repository

    Carroll, Raymond J.

    2011-03-01

    In many applications we can expect that, or are interested to know if, a density function or a regression curve satisfies some specific shape constraints. For example, when the explanatory variable, X, represents the value taken by a treatment or dosage, the conditional mean of the response, Y , is often anticipated to be a monotone function of X. Indeed, if this regression mean is not monotone (in the appropriate direction) then the medical or commercial value of the treatment is likely to be significantly curtailed, at least for values of X that lie beyond the point at which monotonicity fails. In the case of a density, common shape constraints include log-concavity and unimodality. If we can correctly guess the shape of a curve, then nonparametric estimators can be improved by taking this information into account. Addressing such problems requires a method for testing the hypothesis that the curve of interest satisfies a shape constraint, and, if the conclusion of the test is positive, a technique for estimating the curve subject to the constraint. Nonparametric methodology for solving these problems already exists, but only in cases where the covariates are observed precisely. However in many problems, data can only be observed with measurement errors, and the methods employed in the error-free case typically do not carry over to this error context. In this paper we develop a novel approach to hypothesis testing and function estimation under shape constraints, which is valid in the context of measurement errors. Our method is based on tilting an estimator of the density or the regression mean until it satisfies the shape constraint, and we take as our test statistic the distance through which it is tilted. Bootstrap methods are used to calibrate the test. The constrained curve estimators that we develop are also based on tilting, and in that context our work has points of contact with methodology in the error-free case.

  7. Explaining the density profile of self-gravitating systems by statistical mechanics

    Science.gov (United States)

    Kang, Dong-Biao

    A self-gravitating system usually shows a quasi-universal density profile, such as the NFW profile of a simulated dark matter halo, the flat rotation curve of a spiral galaxy, the Sérsic profile of an elliptical galaxy, the King profile of a globular cluster and the exponential law of the stellar disk. It will be interesting if all of the above can be obtained from first principles. Based on the original work of White & Narayan (1987), we propose that if the self-bounded system is divided into infinite infinitesimal subsystems, the entropy of each subsystem can be maximized, but the whole system's gravity may just play the role of the wall, which may not increase the whole system's entropy S t , and finally S t may be the minimum among all of the locally maximized entropies (He & Kang 2010). For spherical systems with isotropic velocity dispersion, the form of the equation of state will be a hybrid of isothermal and adiabatic (Kang & He 2011). Hence this density profile can be approximated by a truncated isothermal sphere, which means that the total mass must be finite and our results can be consistent with observations (Kang & He 2011b). Our method requires that the mass and energy should be conserved, so we only compare our results with simulations of mild relaxation (i.e. the virial ratio is close to -1) of dissipationless collapse (Kang 2014), and the fitting also is well. The capacity can be calculated and is found not to be always negative as in previous works, and combining with calculations of the second order variation of the entropy, we find that the thermodynamical stability still can be true (Kang 2012) if the temperature tends to be zero. However, the cusp in the center of dark matter halos can not be explained, and more works will continue. The above work can be generalized to study the radial distribution of the disk (Kang 2015). The energy constraint automatically disappears in our variation, because angular momentum is much more important than

  8. From the shape of the vertical profile of in vivo fluorescence to Chlorophyll-a concentration

    Science.gov (United States)

    Mignot, A.; Claustre, H.; D'Ortenzio, F.; Xing, X.; Poteau, A.; Ras, J.

    2011-08-01

    In vivo fluorescence of Chlorophyll-a (Chl-a) is a potentially useful property to study the vertical distribution of phytoplankton biomass. However the technique is presently not fully exploited as it should be, essentially because of the difficulties in converting the fluorescence signal into an accurate Chl-a concentration. These difficulties arise noticeably from natural variations in the Chl-a fluorescence relationship, which is under the control of community composition as well as of their nutrient and light status. As a consequence, although vertical profiles of fluorescence are likely the most recorded biological property in the open ocean, the corresponding large databases are underexploited. Here with the aim to convert a fluorescence profile into a Chl-a concentration profile, we test the hypothesis that the Chl-a concentration can be gathered from the sole knowledge of the shape of the fluorescence profile. We analyze a large dataset from 18 oceanographic cruises conducted in case-1 waters from the highly stratified hyperoligotrophic waters (surface Chl-a = 0.02 mg m-3) of the South Pacific Gyre to the eutrophic waters of the Benguela upwelling (surface Chl-a = 32 mg m-3) and including the very deep mixed waters in the North Atlantic (Mixed Layer Depth = 690 m). This dataset encompasses more than 700 vertical profiles of Chl-a fluorescence as well as accurate estimations of Chl-a by High Performance Liquid Chromatography (HPLC). Two typical fluorescence profiles are identified, the uniform profile, characterized by a homogeneous layer roughly corresponding to the mixed layer, and the non-uniform profile, characterized by the presence of a Deep Chlorophyll Maximum. Using appropriate mathematical parameterizations, a fluorescence profile is subsequently represented by 3 or 5 shape parameters for uniform or non-uniform profiles, respectively. For both situations, an empirical model is developed to predict the "true" Chl-a concentration from these shape

  9. From the shape of the vertical profile of in vivo fluorescence to Chlorophyll-a concentration

    Directory of Open Access Journals (Sweden)

    J. Ras

    2011-08-01

    Full Text Available In vivo fluorescence of Chlorophyll-a (Chl-a is a potentially useful property to study the vertical distribution of phytoplankton biomass. However the technique is presently not fully exploited as it should be, essentially because of the difficulties in converting the fluorescence signal into an accurate Chl-a concentration. These difficulties arise noticeably from natural variations in the Chl-a fluorescence relationship, which is under the control of community composition as well as of their nutrient and light status. As a consequence, although vertical profiles of fluorescence are likely the most recorded biological property in the open ocean, the corresponding large databases are underexploited. Here with the aim to convert a fluorescence profile into a Chl-a concentration profile, we test the hypothesis that the Chl-a concentration can be gathered from the sole knowledge of the shape of the fluorescence profile. We analyze a large dataset from 18 oceanographic cruises conducted in case-1 waters from the highly stratified hyperoligotrophic waters (surface Chl-a = 0.02 mg m−3 of the South Pacific Gyre to the eutrophic waters of the Benguela upwelling (surface Chl-a = 32 mg m−3 and including the very deep mixed waters in the North Atlantic (Mixed Layer Depth = 690 m. This dataset encompasses more than 700 vertical profiles of Chl-a fluorescence as well as accurate estimations of Chl-a by High Performance Liquid Chromatography (HPLC. Two typical fluorescence profiles are identified, the uniform profile, characterized by a homogeneous layer roughly corresponding to the mixed layer, and the non-uniform profile, characterized by the presence of a Deep Chlorophyll Maximum. Using appropriate mathematical parameterizations, a fluorescence profile is subsequently represented by 3 or 5 shape parameters for uniform or non-uniform profiles, respectively. For both situations, an empirical model is developed to predict the "true" Chl-a concentration

  10. Accurate bulk density determination of irregularly shaped translucent and opaque aerogels

    Science.gov (United States)

    Petkov, M. P.; Jones, S. M.

    2016-05-01

    We present a volumetric method for accurate determination of bulk density of aerogels, calculated from extrapolated weight of the dry pure solid and volume estimates based on the Archimedes' principle of volume displacement, using packed 100 μm-sized monodispersed glass spheres as a "quasi-fluid" media. Hard particle packing theory is invoked to demonstrate the reproducibility of the apparent density of the quasi-fluid. Accuracy rivaling that of the refractive index method is demonstrated for both translucent and opaque aerogels with different absorptive properties, as well as for aerogels with regular and irregular shapes.

  11. Geomorphic effectiveness of long profile shape and role of inherent geological controls, Ganga River Basin, India

    Science.gov (United States)

    Sonam, Sonam; Jain, Vikrant

    2017-04-01

    River long profile is one of the fundamental geomorphic parameters which provides a platform to study interaction of geological and geomorphic processes at different time scales. Long profile shape is governed by geological processes at 10 ^ 5 - 10 ^ 6 years' time scale and it controls the modern day (10 ^ 0 - 10 ^ 1 years' time scale) fluvial processes by controlling the spatial variability of channel slope. Identification of an appropriate model for river long profile may provide a tool to analyse the quantitative relationship between basin geology, profile shape and its geomorphic effectiveness. A systematic analysis of long profiles has been carried for the Himalayan tributaries of the Ganga River basin. Long profile shape and stream power distribution pattern is derived using SRTM DEM data (90 m spatial resolution). Peak discharge data from 34 stations is used for hydrological analysis. Lithological variability and major thrusts are marked along the river long profile. The best fit of long profile is analysed for power, logarithmic and exponential function. Second order exponential function provides the best representation of long profiles. The second order exponential equation is Z = K1*exp(-β1*L) + K2*exp(-β2*L), where Z is elevation of channel long profile, L is the length, K and β are coefficients of the exponential function. K1 and K2 are the proportion of elevation change of the long profile represented by β1 (fast) and β2 (slow) decay coefficients of the river long profile. Different values of coefficients express the variability in long profile shapes and is related with the litho-tectonic variability of the study area. Channel slope of long profile is estimated taking the derivative of exponential function. Stream power distribution pattern along long profile is estimated by superimposing the discharge and long profile slope. Sensitivity analysis of stream power distribution with decay coefficients of the second order exponential equation is

  12. T-shaped competency profile for water professionals of the future

    NARCIS (Netherlands)

    Uhlenbrook, S.; De Jong, E.

    2012-01-01

    Global environmental changes introduce new challenges and expose future university graduates in hydrology and related fields to problems of unprecedented complexity and magnitude. The T-shape model is proposed as a generic competency profile guiding the design of university curricula. This model dif

  13. Profile of Secondary School Students with High Mathematics Ability in Solving Shape and Space Problem

    Science.gov (United States)

    Putra, Mulia; Novita, Rita

    2015-01-01

    This study aimed to describe the profile of secondary school students with high mathematics ability in solving shape and space problem in PISA (Program for International Student Assessment). It is a descriptive research with a qualitative approach, in which the subjects in this study were students of class VIII SMP N 1 Banda Aceh. The results show…

  14. Modelling the pultrusion process of an industrial L-shaped composite profile

    NARCIS (Netherlands)

    Baran, Ismet; Akkerman, Remko; Hattel, Jesper H.

    2014-01-01

    A numerical process simulation tool is developed for the pultrusion of an industrial L-shaped profile. The composite contains the combination of uni-directional (UD) roving and continuous filament mat (CFM) layers impregnated by a polyester resin system specifically prepared for the process. The che

  15. Observation of a shape-dependent density maximum in random prackigns and glasses of colloidal silica ellipsoids

    NARCIS (Netherlands)

    Sacanna, S.; Rossi, L.; Wouterse, A.; Philipse, A.P.

    2007-01-01

    We have measured the random packing density of monodisperse colloidal silica ellipsoids with a well-defined shape, gradually deviating from a sphere shape up to prolates with aspect ratios of about 5, to find for a colloidal system the first experimental observation for the density maximum (at an as

  16. EFFECT OF PROFILES AND SHAPE ON IDEAL STABILITY OF ADVANCED TOKAMAK EQUILIBRIA

    Energy Technology Data Exchange (ETDEWEB)

    MAKOWSKI,MA; CASPER,TA; FERRON,JR; TAYLOR,TS; TURNBULL,AD

    2003-08-01

    OAK-B135 The pressure profile and plasma shape, parameterized by elongation ({kappa}), triangularity ({delta}), and squareness ({zeta}), strongly influence stability. In this study, ideal stability of single null and symmetric, double-null, advanced tokamak (AT) configurations is examined. All the various shapes are bounded by a common envelope and can be realized in the DIII-D tokamak. The calculated AT equilibria are characterized by P{sub 0}/

    {approx} 2.0-4.5, weak negative central shear, high q{sub min} (> 2.0), high bootstrap fraction, an H-mode pedestal, and varying shape parameters. The pressure profile is modeled by various polynomials together with a hyperbolic tangent pedestal, consistent with experimental observations. Stability is calculated with the DCON code and the resulting stability boundary is corroborated by GATO runs.

  17. Statistics of cosmic density profiles from perturbation theory

    CERN Document Server

    Bernardeau, Francis; Codis, Sandrine

    2013-01-01

    The joint probability distribution function (PDF) of the density within multiple concentric spherical cells is considered. It is shown how its cumulant generating function can be obtained at tree order in perturbation theory as the Legendre transform of a function directly built in terms of the initial moments. In the context of the upcoming generation of large-scale structure surveys, it is conjectured that this result correctly models such a function for finite values of the variance. Detailed consequences of this assumption are explored. In particular the corresponding one-cell density probability distribution at finite variance is computed for realistic power spectra, taking into account its scale variation. It is found to be in agreement with $\\Lambda$-CDM simulations at the few percent level for a wide range of density values and parameters. Related explicit analytic expansions at the low and high density tails are given. The conditional (at fixed density) and marginal probability of the slope -- the de...

  18. A "Universal" Density Profile for the Outer Stellar Halos of Galaxies

    CERN Document Server

    Remus, Rhea-Silvia; Dolag, Klaus

    2016-01-01

    The outer stellar halos of galaxies contain vital information about the formation history of galaxies, since the relaxation timescales in the outskirts are long enough to keep the memory, while the information about individual formation events in the central parts has long been lost due to mixing, star formation and relaxation. To unveil some of the information encoded in these faint outer halo regions, we study the stellar outskirts of galaxies selected from a fully hydrodynamical high resolution cosmological simulation, called Magneticum. We find that the density profiles of the outer stellar halos of galaxies over a broad mass range can be well described by an Einasto profile. For a fixed total mass range, the free parameters of the Einasto fits are closely correlated. Galaxies which had more (dry) merger events tend to have lesser curved outer stellar halos, however, we find no indication that the amount of curvature is correlated with galaxy morphology. The Einasto-like shape of the outer stellar halo de...

  19. Factors influencing the density profiles of granular flux in a two-dimensional inclined channel

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The two-dimensional dilute granular flow on a smooth incline bounded by rough sidewalls is investigated experimentally, and the transverse density profiles of granular flux (ξ = ρ v) across the channel are measured. The results show that the transverse density profiles of granular flux are symmetric about the channel center and that the density of granular flux near the boundary is clearly lower than that of the center. There is a critical width of channel Wc for the transition of the density of granular flux. The density of granular flux near the boundary decays with the increasing of inclination (sinθ ) of the channel.

  20. Factors influencing the density profiles of granular flux in a two-dimensional inclined channel

    Institute of Scientific and Technical Information of China (English)

    BAO DeSong; ZHOU Ying; ZHANG XunSheng; TANG XiaoWei

    2009-01-01

    The two-dimensional dilute granular flow on a smooth incline bounded by rough sidewalls is investigated experimentally, and the transverse density profiles of granular flux (ξ=pv) across the channel are measured. The results show that the transverse density profiles of granular flux are symmetric about the channel center and that the density of granular flux near the boundary is clearly lower than that of the center. There is a critical width of channel Wc for the transition of the density of granular flux. The density of granular flux near the boundary decays with the increasing of inclination (sinθ) of the channel.

  1. The Initial Mass Function and the Surface Density Profile of NGC 6231

    CERN Document Server

    Sung, Hwankyung; Bessell, M S

    2012-01-01

    We have performed new wide-field photometry of the young open cluster NGC 6231 to study the shape of the initial mass function (IMF) and mass segregation. We also investigated the reddening law toward NGC 6231 from optical to mid-infrared color excess ratios, and found that the total-to-selective extinction ratio is Rv = 3.2, which is very close to the normal value. But many early-type stars in the cluster center show large color excess ratios. We derived the surface density profiles of four member groups, and found that they reach the surface density of field stars at about 10', regardless of stellar mass. The IMF of NGC 6231 is derived for the mass range 0.8 -- 45 Msun. The slope of the IMF of NGC 6231 (Gamma = -1.1 +/- 0.1) is slightly shallower than the canonical value, but the difference is marginal. In addition, the mass function varies systematically, and is a strong function of radius - it is is very shallow at the center, and very steep at the outer ring suggesting the cluster is mass segregated. We ...

  2. Tetrahedral shape and surface density wave of $^{16}$O caused by $\\alpha$-cluster correlations

    CERN Document Server

    Kanada-En'yo, Yoshiko

    2016-01-01

    $\\alpha$-cluster correlations in the $0^+_1$ and $3^-_1$ states of $^{12}$C and $^{16}$O are studied using the method of antisymmetrized molecular dynamics, with which nuclear structures are described from nucleon degrees of freedom without assuming existence of clusters. The intrinsic states of $^{12}$C and $^{16}$O have triangle and tetrahedral shapes, respectively, because of the $\\alpha$-cluster correlations. These shapes can be understood as spontaneous symmetry breaking of rotational invariance, and the resultant surface density oscillation is associated with density wave (DW) caused by the instability of Fermi surface with respect to particle-hole correlations with the wave number $\\lambda=3$. $^{16}$O($0^+_1$) and $^{16}$O($3^-_1$) are regarded as a set of parity partners constructed from the rigid tetrahedral intrinsic state, whereas $^{12}$C($0^+_1$) and $^{12}$C($3^-_1$) are not good parity partners as they have triangle intrinsic states of different sizes with significant shape fluctuation because...

  3. Electron number density profiles derived from radio occultation on the CASSIOPE spacecraft

    DEFF Research Database (Denmark)

    Shume, E. B.; Vergados, P.; Komjathy, A.

    2017-01-01

    good agreement with density profiles estimated from ionosonde data, measured over nearby stations to the latitude and longitude of the RO tangent points, (2) in good agreement with density profiles inferred from GPS RO measured by the Constellation Observing System for Meteorology, Ionosphere......, and Climate (COSMIC), and (3) in general agreement with density profiles estimated using the International Reference Ionosphere (IRI) climatological model. Using both CASSIOPE and COSMIC RO observations, we identify, for the first time, that there exist differences in the characteristics of the electron...

  4. Dependence of the outer density profiles of halos on their mass accretion rate

    Energy Technology Data Exchange (ETDEWEB)

    Diemer, Benedikt; Kravtsov, Andrey V., E-mail: bdiemer@oddjob.uchicago.edu [Department of Astronomy and Astrophysics, The University of Chicago, Chicago, IL 60637 (United States)

    2014-07-01

    We present a systematic study of the density profiles of ΛCDM halos, focusing on the outer regions, 0.1 < r/R {sub vir} < 9. We show that the median and mean profiles of halo samples of a given peak height exhibit significant deviations from the universal analytic profiles discussed previously in the literature, such as the Navarro-Frenk-White and Einasto profiles, at radii r ≳ 0.5R {sub 200m}. In particular, at these radii the logarithmic slope of the median density profiles of massive or rapidly accreting halos steepens more sharply than predicted. The steepest slope of the profiles occurs at r ≈ R {sub 200m}, and its absolute value increases with increasing peak height or mass accretion rate, reaching slopes of –4 and steeper. Importantly, we find that the outermost density profiles at r ≳ R {sub 200m} are remarkably self-similar when radii are rescaled by R {sub 200m}. This self-similarity indicates that radii defined with respect to the mean density are preferred for describing the structure and evolution of the outer profiles. However, the inner density profiles are most self-similar when radii are rescaled by R {sub 200c}. We propose a new fitting formula that describes the median and mean profiles of halo samples selected by their peak height or mass accretion rate with accuracy ≲ 10% at all radii, redshifts, and masses we studied, r ≲ 9R {sub vir}, 0 < z < 6, and M {sub vir} > 1.7 × 10{sup 10} h {sup –1} M {sub ☉}. We discuss observational signatures of the profile features described above and show that the steepening of the outer profile should be detectable in future weak-lensing analyses of massive clusters. Such observations could be used to estimate the mass accretion rate of cluster halos.

  5. BN/BNSiO2 sputtering yield shape profiles under stationary plasma thruster operating conditions

    Directory of Open Access Journals (Sweden)

    M. Ranjan

    2016-09-01

    Full Text Available Quartz Crystal Microbalance (QCM is used to measure the volumetric and total sputtering yield of Boron Nitride (BN and Boron Nitride Silicon Dioxide (BNSiO2 bombarded by Xenon ions in the energy range of 100 eV to 550 eV. Sputtering yield shape profiles are reported at various angles of incidence 0-85° with surface normal and compared with modified Zhang model. The yield shape profile is found to be symmetric at normal incidence and asymmetric at oblique incidence. Both the materials show a sudden jump in the sputtering yield above 500 eV and at an angle of incidence in the range of 45-65°. Erosion of BN at as low as 74 eV ion energy is predicted using generalized Bohdansky model. BNSiO2 show a marginally higher sputtering yield compare to BN.

  6. Metasurfaces-based holography and beam shaping: engineering the phase profile of light

    Science.gov (United States)

    Scheuer, Jacob

    2017-01-01

    The ability to engineer and shape the phase profile of optical beams is in the heart of any optical element. Be it a simple lens or a sophisticated holographic element, the functionality of such components is dictated by their spatial phase response. In contrast to conventional optical components which rely on thickness variation to induce a phase profile, metasurfaces facilitate the realization of arbitrary phase distributions using large arrays with sub-wavelength and ultrathin (tens of nanometers) features. Such components can be easily realized using a single lithographic step and is highly suited for patterning a variety of substrates, including nonplanar and soft surfaces. In this article, we review the recent developments, potential, and opportunities of metasurfaces applications. We focus primarily on flat optical devices, holography, and beam-shaping applications as these are the key ingredients needed for the development of a new generation of optical devices which could find widespread applications in photonics.

  7. Shape evolution of 72,74Kr with temperature in covariant density functional theory

    Science.gov (United States)

    Zhang, Wei; Niu, Yi-Fei

    2017-09-01

    The rich phenomena of deformations in neutron-deficient krypton isotopes, such as shape evolution with neutron number and shape coexistence, have attracted the interest of nuclear physicists for decades. It is interesting to study such shape phenomena using a novel way, e.g. by thermally exciting the nucleus. In this work, we develop the finite temperature covariant density functional theory for axially deformed nuclei with the treatment of pairing correlations by the BCS approach, and apply this approach for the study of shape evolution in 72,74Kr with increasing temperature. For 72Kr, with temperature increasing, the nucleus firstly experiences a relatively quick weakening in oblate deformation at temperature T ∼0.9 MeV, and then changes from oblate to spherical at T ∼2.1 MeV. For 74Kr, its global minimum is at quadrupole deformation β2 ∼ ‑0.14 and abruptly changes to spherical at T∼ 1.7 MeV. The proton pairing transition occurs at critical temperature 0.6 MeV following the rule Tc=0.6Δp(0), where Δp(0) is the proton pairing gap at zero temperature. The signatures of the above pairing transition and shape changes can be found in the specific heat curve. The single-particle level evolutions with temperature are presented. Supported by National Natural Science Foundation of China (11105042, 11305161, 11505157), Open Fund of Key Laboratory of Time and Frequency Primary Standards, CAS, and Support from Henan Administration of Foreign Experts Affairs

  8. On the density profile of dark matter substructure in gravitational lens galaxies

    CERN Document Server

    Vegetti, Simona

    2014-01-01

    We consider three extensions of the Navarro, Frenk and White (NFW) profile and investigate the intrinsic degeneracies among the density profile parameters on the gravitational lensing effect of satellite galaxies on highly magnified Einstein rings. In particular, we find that the gravitational imaging technique can be used to exclude specific regions of the considered parameter space, and therefore, models that predict a large number of satellites in those regions. By comparing the lensing degeneracy with the intrinsic density profile degeneracies, we show that theoretical predictions based on fits that are dominated by the density profile at larger radii may significantly over- or underestimate the number of satellites that are detectable with gravitational lensing. Finally, using the previously reported detection of a satellite in the gravitational lens system JVAS B1938+666 as an example, we derive for this detected satellite values of r_max and v_max that are, for each considered profile, consistent withi...

  9. Energy density distribution of shaped waves inside scattering media mapped onto a complete set of diffusion modes

    CERN Document Server

    Ojambati, Oluwafemi S; Vellekoop, Ivo M; Lagendijk, Ad; Vos, Willem L

    2016-01-01

    We show that the spatial distribution of the energy density of optimally shaped waves inside a scattering medium can be described by considering only a few of the lowest eigenfunctions of the diffusion equation. Taking into account only the fundamental eigenfunction, the total internal energy inside the sample is underestimated by only 2%. The spatial distribution of the shaped energy density is very similar to the fundamental eigenfunction, up to a cosine distance of about 0.01. We obtained the energy density inside a quasi-1D disordered waveguide by numerical calculation of the joined scattering matrix. Computing the transmission-averaged energy density over all transmission channels yields the ensemble averaged energy density of shaped waves. From the averaged energy density obtained, we reconstruct its spatial distribution using the eigenfunctions of the diffusion equation. The results from our study have exciting applications in controlled biomedical imaging, efficient light harvesting in solar cells, en...

  10. Surface profiling of X-ray mirrors for shaping focused beams.

    Science.gov (United States)

    Laundy, David; Alianelli, Lucia; Sutter, John; Evans, Gwyndaf; Sawhney, Kawal

    2015-01-26

    Grazing incidence mirrors are a standard optic for focusing X-rays. Active mirrors, whose surface profile can be finely adjusted, allow control of beam shape and size at the sample. However, progress towards their routine use for beam shaping has been hampered by the strong striations in reflected beams away from the focal plane. Re-entrant (partly concave and partly convex) surface modifications are proposed for shaping X-ray beams to a top-hat in the focal plane while reducing the striations caused by unavoidable polishing errors. A method for constructing such surfaces with continuous height and slope (but only piecewise continuous curvature) will be provided. Ray tracing and wave propagation calculations confirm its effectiveness. A mirror system is proposed allowing vertical beam sizes in the range 0.5 to 10μm. A prototype will be fabricated and is expected to have applications on many synchrotron X-ray beamlines.

  11. Advances in the density profile evaluation from broadband reflectometry on ASDEX upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Varela, P.; Manso, M. [Associacao EURATOM/IST, Centro de Fusao Nuclear, Instituto Superior Tecnico, Lisboa (Portugal); Conway, G. [Max-Planck-Instituet fuer Plasmaphysik, EURATOM Association, Garching (Germany)

    2001-05-01

    The high temporal and spatial resolutions provided by broadband microwave reflectometry make it an attractive diagnostic technique to measure the density profile in fusion plasmas. However, great problems have been encountered due to the plasma turbulence that difficult, and sometimes prevent, the routine evaluation of density profiles. Advanced broadband systems employ ultra-fast sweeping in an attempt to perform the profile measurement in a time window smaller than the temporal scale of the main plasma fluctuations but this is not sufficient. Indeed, abrupt plasma movements and/or spatial turbulence always affect the reflectometry signals, as shown by numerical studies (with both one- and two-dimensional codes), for the case of ultra-fast sweeping and pulse radar systems. For this reason not only the system performance is important but the software tools also play a crucial role for reflectometry to become a standard density profile diagnostic. Here we present the recent advances towards automatic evaluation of density profiles from broadband reflectometry on ASDEX Upgrade. For regimes with moderate levels of plasma turbulence, density profiles are obtained from single reflectometry samples (temporal resolution of 20 {mu}s), and for higher turbulence levels average profiles are obtained from bursts of ultra-fast (20 {mu}s), closely spaced (10 {mu}s) sweeps. This method improved the accuracy and reliability of density profiles, which can now be obtained automatically from the edge to the bulk plasma - using reflectometry alone - in most plasma regimes of ASDEX Upgrade. New data processing capability has been implemented that allows the profiles to be available to the end-users 10-12 minutes after each discharge. These developments were possible due to the flexibility and high performance of the control and data acquisition systems and to the large number of measurements that can be performed with the diagnostic during each discharge (720 profiles both on the low

  12. Cluster density profiles as a test of modified gravity

    Science.gov (United States)

    Lombriser, Lucas; Schmidt, Fabian; Baldauf, Tobias; Mandelbaum, Rachel; Seljak, Uroš; Smith, Robert E.

    2012-05-01

    We present a new test of gravitational interactions at the r≃(0.2-20)Mpc scale, around the virial radius of dark matter halos measured through cluster-galaxy lensing of maxBCG clusters from the Sloan Digital Sky Survey (SDSS). We employ predictions from self-consistent simulations of f(R) gravity to find an upper bound on the background field amplitude of |fR0|confidence level. As a model-independent assessment of the constraining power of cluster profiles measured through weak gravitational lensing, we also constrain the amplitude F0 of a phenomenological modification based on the profile enhancement induced by f(R) gravity when not including effects from the increased cluster abundance in f(R). In both scenarios, dark-matter-only simulations of the concordance model corresponding to |fR0|=0 and F0=0 are consistent with the lensing measurements, i.e., at the 68% and 95% confidence level, respectively.

  13. Near-exponential surface densities as hydrostatic, nonequilibrium profiles in galaxy discs

    CERN Document Server

    Struck, Curtis

    2016-01-01

    Apparent exponential surface density profiles are nearly universal in galaxy discs across Hubble types, over a wide mass range, and a diversity of gravitational potential forms. Several processes have been found to produce exponential profiles, including the actions of bars and spirals, and clump scattering, with star scattering a common theme in these. Based on reasonable physical constraints, such as minimal entropy gradients, we propose steady state distribution functions for disc stars, applicable over a range of gravitational potentials. The resulting surface density profiles are generally a power-law term times a Sersic-type exponential. Over a modest range of Sersic index values, these profiles are often indistinguishable from Type I exponentials, except at the innermost radii. However, in certain parameter ranges these steady states can appear as broken, Type II or III profiles. The corresponding velocity dispersion profiles are low order power-laws. A chemical potential associated with scattering can...

  14. A reduced density-matrix theory of absorption line shape of molecular aggregate.

    Science.gov (United States)

    Yang, Mino

    2005-09-22

    A theory for the absorption line shape of molecular aggregates in condensed phase is formulated based on a reduced density-matrix approach. Intermolecular couplings in the aggregates are assumed to be weak (Förster type of energy transfer mechanism). The spin-Boson model is employed to include the effect of electron-phonon coupling. Using the projection operator technique, we derive kinetic equations for the reduced electronic density matrix associated with the absorption spectrum. General expressions of time-dependent rate constants in the kinetic equations are derived by using the cumulant expansion technique. The resulting time-dependent kinetic equations are solved numerically. We illustrate the applicability of the present theory by calculating the line shape of a dimer (a pair of donor and acceptor of energy transfer). For a J-aggregate type of molecular pair (with excitonic redshift), a tail appears on the blue side of the absorption spectrum due to the existence of inhomogeneity in electronic state mixing which is originated from the electron-phonon coupling.

  15. Numerical analysis of dimension precision of U-shaped aluminium profile rotary stretch bending

    Institute of Scientific and Technical Information of China (English)

    YU Zhong-qi; LIN Zhong-qin

    2007-01-01

    In order to enhance the dimension precision of bent part, advanced bending technologies is requested recently. Rotary stretch bending(RSB) is a suitable technology to realize high precision of bent part. The effect of processing parameters, namely the side pressure and the stretching force, on the dimension precision of aluminium profile RSB part was studied by finite element method. The numerical simulation of the U-shaped aluminium profile RSB was carried out, and the validity of the simulation was checked. Parametric analysis shows that the section distortion of the U-shaped profile LY12M bent part decreases with the increasing of the side pressure, whereas the springback of curvature increases, and that both of the section distortion and the springback of curvature decrease with the increasing of the stretching force, moreover, the uniformity of curvature of the bent part is clearly enhanced with the increasing of the stretching force. The results above prove that RSB technology can better improve the dimension precision of aluminium profile bent part.

  16. Spectral Line-Shape Model to Replace the Voigt Profile in Spectroscopic Databases

    Science.gov (United States)

    Lisak, Daniel; Ngo, Ngoc Hoa; Tran, Ha; Hartmann, Jean-Michel

    2014-06-01

    The standard description of molecular line shapes in spectral databases and radiative transfer codes is based on the Voigt profile. It is well known that its simplified assumptions of absorber free motion and independence of collisional parameters from absorber velocity lead to systematic errors in analysis of experimental spectra, and retrieval of gas concentration. We demonstrate1,2 that the partially correlated quadratic speed-dependent hardcollision profile3. (pCqSDHCP) is a good candidate to replace the Voigt profile in the next generations of spectroscopic databases. This profile takes into account the following physical effects: the Doppler broadening, the pressure broadening and shifting of the line, the velocity-changing collisions, the speed-dependence of pressure broadening and shifting, and correlations between velocity- and phase/state-changing collisions. The speed-dependence of pressure broadening and shifting is incorporated into the pCqSDNGP in the so-called quadratic approximation. The velocity-changing collisions lead to the Dicke narrowing effect; however in many cases correlations between velocityand phase/state-changing collisions may lead to effective reduction of observed Dicke narrowing. The hard-collision model of velocity-changing collisions is also known as the Nelkin-Ghatak model or Rautian model. Applicability of the pCqSDHCP for different molecular systems was tested on calculated and experimental spectra of such molecules as H2, O2, CO2, H2O in a wide span of pressures. For all considered systems, pCqSDHCP is able to describe molecular spectra at least an order of magnitude better than the Voigt profile with all fitted parameters being linear with pressure. In the most cases pCqSDHCP can reproduce the reference spectra down to 0.2% or better, which fulfills the requirements of the most demanding remote-sensing applications. An important advantage of pCqSDHCP is that a fast algorithm for its computation was developedab4,5 and allows

  17. Observing the dark matter density profile of isolated galaxies

    CERN Document Server

    Prada, F; Klypin, A; Holtzman, J A; Schlegel, D J; Grebel, E K; Rix, H W; Brinkmann, J; McKay, T A; Csabai, I; Prada, Francisco; Vitvitska, Mayrita; Klypin, Anatoly; Holtzman, Jon A.; Schlegel, David J.; Grebel, Eva K.

    2003-01-01

    Using the Sloan Digital Sky Survey (SDSS), we probe the halo mass distribution by studying the velocities of satellites orbiting isolated galaxies. In a subsample that covers 2500 sq. degrees on the sky, we detect about 3000 satellites with absolute blue magnitudes going down to M_B = -14; most of the satellites have M_B=-16 to -18, comparable to the magnitudes of M32 and the Magellanic Clouds. After a careful, model-independent removal of interlopers, we find that the line-of-sight velocity dispersion of satellites declines with distance to the primary. For an L* galaxy the r.m.s. line-of-sight velocity changes from ~120 km/s at 20 kpc to ~60 km/s at 350 kpc. This decline agrees remarkably well with theoretical expectations, as all modern cosmological models predict that the density of dark matter in the peripheral parts of galaxies declines as rho_DM propto r^{-3}. Thus, for the first time we find direct observational evidence of the density decline predicted by cosmological models; we also note that this r...

  18. Cluster Density Profiles as a Test of Modified Gravity

    CERN Document Server

    Lombriser, Lucas; Baldauf, Tobias; Mandelbaum, Rachel; Seljak, Uros; Smith, Robert E

    2011-01-01

    We present a new test of gravitational interactions at the r\\simeq(0.2-20)Mpc scale, around the virial radius of dark matter halos measured through cluster-galaxy lensing of maxBCG clusters from the Sloan Digital Sky Survey (SDSS). We employ predictions from self-consistent simulations of f(R) gravity to find an upper bound on the background field amplitude of f_R0<3.5x10^-3 at the 1D-marginalized 95% confidence level. We also constrain the amplitude F_0 of a phenomenological fit modeled on the profile enhancement induced by f(R) gravity when not including effects from the increased cluster abundance in f(R). In both scenarios, dark-matter-only simulations of the concordance model corresponding to f_R0=0 and F_0=0 are consistent with the lensing measurements at the 68% confidence level.

  19. Relating the shape of protein binding sites to binding affinity profiles: is there an association?

    Directory of Open Access Journals (Sweden)

    Bitter István

    2010-10-01

    Full Text Available Abstract Background Various pattern-based methods exist that use in vitro or in silico affinity profiles for classification and functional examination of proteins. Nevertheless, the connection between the protein affinity profiles and the structural characteristics of the binding sites is still unclear. Our aim was to investigate the association between virtual drug screening results (calculated binding free energy values and the geometry of protein binding sites. Molecular Affinity Fingerprints (MAFs were determined for 154 proteins based on their molecular docking energy results for 1,255 FDA-approved drugs. Protein binding site geometries were characterized by 420 PocketPicker descriptors. The basic underlying component structure of MAFs and binding site geometries, respectively, were examined by principal component analysis; association between principal components extracted from these two sets of variables was then investigated by canonical correlation and redundancy analyses. Results PCA analysis of the MAF variables provided 30 factors which explained 71.4% of the total variance of the energy values while 13 factors were obtained from the PocketPicker descriptors which cumulatively explained 94.1% of the total variance. Canonical correlation analysis resulted in 3 statistically significant canonical factor pairs with correlation values of 0.87, 0.84 and 0.77, respectively. Redundancy analysis indicated that PocketPicker descriptor factors explain 6.9% of the variance of the MAF factor set while MAF factors explain 15.9% of the total variance of PocketPicker descriptor factors. Based on the salient structures of the factor pairs, we identified a clear-cut association between the shape and bulkiness of the drug molecules and the protein binding site descriptors. Conclusions This is the first study to investigate complex multivariate associations between affinity profiles and the geometric properties of protein binding sites. We found that

  20. The influence of third-order interactions on the density profile of associating hard spheres

    Science.gov (United States)

    Henderson, D.; Sokolowski, S.; Zagorski, R.; Trokhymchuk, A.

    Canonical ensemble Monte Carlo simulations and the non-uniform Percus-Yevick (NPY) equation for the local density are used to study the influence of surface mediated thirdorder interactions on the adsorption of associating hard spheres on a hard wall. A comparison of the NPY density profiles with the computer simulations data indicates that this approximation predicts the fluid structure reasonably well.

  1. High precision measurement of fuel density profiles in nuclear fusion plasmas

    NARCIS (Netherlands)

    Svensson, J.; von Hellermann, M.; Konig, R.

    2002-01-01

    This paper presents a method for deducing fuel density profiles of nuclear fusion plasmas in realtime during an experiment. A Multi Layer Perceptron (MLP) neural network is used to create a mapping between plasma radiation spectra and indirectly deduced hydrogen isotope densities. By combining diffe

  2. Hollow radial electron density profiles in surface wave discharges. An inside job?

    Science.gov (United States)

    Jimenez-Diaz, Manuel; Rahimi, Sara; Carbone, Emile A. D.; Dijk, Jan Van

    2013-09-01

    In many microwave excited plasmas, there is a part of the discharge (tube) hidden from optical access e.g. because of the metal parts that cover it; it is the region where the transformation occurs between the EM modes found in the (metal) waveguide to modes in the plasma (waveguide). Because in most of cases optical access is not an option here, studies of this region remain scarce. Regardless of this, it is a well-known fact that the discharge tube can easily break due to the high temperatures inside the launcher of surfaguide discharges, which means the temperature is higher there than in other regions of the plasma. In this work, we use a 2D model to show how the inner region changes for increasing power absorbed and electromagnetic wave frequency. The shaping of the EM coupling into the plasma region by the cavity is explored as well. We discuss when the hollow radial profiles for the electron density appear in a surfaguide plasma, and how they are related to the radial inhomogeneity of the EM fields and the plasma properties (e.g. gas temperature). All these results were obtained using the modeling platform Plasimo. Supported by the Dutch Technology Foundation (STW Project Nos. 10497 and 10744) and by the Energy Research Center of the Netherlands (ECN).

  3. Modeling the convective stability of CO2 sequestration by a discontinuous and unstably stratified density profile

    Science.gov (United States)

    Wanstall, Taber; Hadji, Layachi

    2016-11-01

    The convective stability associated with carbon sequestration is modeled by adopting an unstably stratified basic profile having a step function density with top heavy carbon saturated layer overlying a lighter carbon free layer. The model takes into account the anisotropy in both permeability and carbon dioxide diffusion, and chemical reactions between the CO2 rich brine and host mineralogy. We carry out a linear stability analysis to derive the instability threshold parameters for a variety of CO2 boundary conditions. We solve for the minimum thickness of the carbon-rich layer at which convection sets in and quantify how its value is influenced by diffusion, anisotropy, permeability, reaction and type of boundary conditions. The discontinuity leads to convective concentration contours that have the shape of an asymmetric lens which we quantify by deriving and making use of the CO2 flux expressions at the interface. The linear problem is extended to the nonlinear regime, the analysis of which leads to the determination of a uniformly valid super critical steady solution.

  4. Understanding the core density profile in TCV H-mode plasmas

    CERN Document Server

    Wágner, Dávid; Pitzschke, Andreas; Sauter, Olivier; Weisen, Henri

    2012-01-01

    Results from a database analysis of H-mode electron density profiles on the Tokamak \\`a Configuration Variable (TCV) in stationary conditions show that the logarithmic electron density gradient increases with collisionality. By contrast, usual observations of H-modes showed that the electron density profiles tend to flatten with increasing collisionality. In this work it is reinforced that the role of collisionality alone, depending on the parameter regime, can be rather weak and in these, dominantly electron heated TCV cases, the electron density gradient is tailored by the underlying turbulence regime, which is mostly determined by the ratio of the electron to ion temperature and that of their gradients. Additionally, mostly in ohmic plasmas, the Ware-pinch can significantly contribute to the density peaking. Qualitative agreement between the predicted density peaking by quasi-linear gyrokinetic simulations and the experimental results is found. Quantitative comparison would necessitate ion temperature meas...

  5. Experimental approach to shape field relevant blast wave profiles in compressed gas-driven shock tube

    Directory of Open Access Journals (Sweden)

    Aravind eSundaramurthy

    2014-12-01

    Full Text Available Detonation of a high explosive produces shock-blast wave, shrapnel, and gaseous products. While direct exposure to blast is a concern near the epicenter, shock-blast can affect subjects even at farther distances, which is termed as primary blast injury, which is the theme of this work. The shock-blast profile is characterized with blast overpressure, positive time duration, and impulse as shock-blast wave parameters (SWPs. These parameters in turn are a function of field factors, such as the strength of high explosive and the distance of the human subjects from the epicenter. The shape and magnitude of the profile determine the severity of injury to the subjects. As shown in some of our recent works (Chandra et al., 2011;Sundaramurthy et al., 2012;Skotak et al., 2013, the profile not only determines the survival of the animal but also the acute and chronic biomechanical injuries along with the following bio-chemical sequelae. It is extremely important to carefully design and operate the shock tube to produce field relevant SWPs. Furthermore, it is vital to identify and eliminate the artifacts that are inadvertently introduced in the shock-blast profile that may affect the results. In this work, we examine the relationship between shock tube adjustable parameters (SAPs and SWPs that can be used to control the blast profile; the results can be easily applied to many of the laboratory shock tubes. Further, exact replication of shock profile (magnitude and shape can be related to field explosions and can be a standard in comparing results across different laboratories. 40 experiments are carried out by judiciously varying SAPs such as membrane thickness, breech length (66.68 to 1209.68 mm, measurement location, and type of driver gas (nitrogen, helium. The relationships between SAPs and the resulting shock-blast profiles are characterized. Finally, shock-blast profiles of a TNT explosion from ConWep software is compared with the profiles obtained

  6. Effect of Control Blade History, and Axial Coolant Density and Burnup Profiles on BWR Burnup Credit

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, William BJ J [ORNL

    2016-01-01

    A technical basis for peak reactivity boiling water reactor (BWR) burnup credit (BUC) methods was recently generated, and the technical basis for extended BWR BUC is now being developed. In this paper, a number of effects related to extended BWR BUC are analyzed, including three major operational effects in BWRs: the coolant density axial distribution, the use of control blades during operation, and the axial burnup profile. Specifically, uniform axial moderator density profiles are analyzed and compared to previous results and an additional temporal fidelity study combing moderator density profiles for three different fuel assemblies is presented. Realistic control blade histories and cask criticality results are compared to previously generated constructed control blade histories. Finally, a preliminary study of the axial burnup profile is provided.

  7. Modification of SOL profiles and fluctuations with line-average density and divertor flux expansion in TCV

    DEFF Research Database (Denmark)

    Vianello, N.; Tsui, C.; Theiler, C.

    2017-01-01

    that this modification does not influence neither the detachment density threshold, nor the development of a flat SOL density profile which instead depends strongly on the increase of the core line average density. The modification of the SOL upstream profile, with the appearance of what is generally called a density...

  8. Development of the W-band density profile and fluctuation reflectometer on EAST

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.M.; Gao, X., E-mail: xgao@ipp.ac.cn; Ling, B.L.; Zhang, S.B.; Zhang, T.; Han, X.; Liu, S.C.; Liu, Z.X.; Liu, Y.; Ti, A.

    2013-11-15

    Highlights: • A X-mode W-band reflectometer is designed and installed on Experimental Advanced Superconducting Tokamak (EAST) for the first time. • Both density profile and fluctuations can be measured by the newly developed reflectometer. • The core density profile has been measured in high magnetic field condition together with V-band reflectometer. • Sawtooth precursor has been measured by fluctuation reflectometer in the low magnetic field condition. -- Abstract: A X-mode polarized W-band reflectometer for plasma density profile and fluctuation measurement is designed and installed on EAST. In measuring the density profile, a voltage controlled oscillator (VCO) is used as the source, allowing a high temporal resolution measurement. The density profile in a plasma with high magnetic field (3.0 T) has been measured by combination of V- and W-band reflectometers. For fluctuation measurements, a frequency synthesizer is used instead of the VCO as a microwave source. The core density fluctuations during sawtooth activity are measured and analyzed.

  9. Theory for planetary exospheres: II. Radiation pressure effect on exospheric density profiles

    CERN Document Server

    Beth, Arnaud; Toublanc, Dominique; Dandouras, Iannis; Mazelle, Christian

    2015-01-01

    The planetary exospheres are poorly known in their outer parts, since the neutral densities are low compared with the instruments detection capabilities. The exospheric models are thus often the main source of information at such high altitudes. We present a new way to take into account analytically the additional effect of the radiation pressure on planetary exospheres. In a series of papers, we present with an Hamiltonian approach the effect of the radiation pressure on dynamical trajectories, density profiles and escaping thermal flux. Our work is a generalization of the study by Bishop and Chamberlain (1989). In this second part of our work, we present here the density profiles of atomic Hydrogen in planetary exospheres subject to the radiation pressure. We first provide the altitude profiles of ballistic particles (the dominant exospheric population in most cases), which exhibit strong asymmetries that explain the known geotail phenomenon at Earth. The radiation pressure strongly enhances the densities c...

  10. Self-similarity and universality of void density profiles in simulation and SDSS data

    CERN Document Server

    Nadathur, S; Diego, J M; Iliev, I T; Gottlöber, S; Watson, W A; Yepes, G

    2014-01-01

    The stacked density profile of cosmic voids in the galaxy distribution provides an important tool for the use of voids for precision cosmology. We study the density profiles of voids identified using the ZOBOV watershed transform algorithm in realistic mock luminous red galaxy (LRG) catalogues from the Jubilee simulation, as well as in void catalogues constructed from the SDSS LRG and Main Galaxy samples. We compare different methods for reconstructing density profiles scaled by the void radius and show that the most commonly used method based on counts in shells and simple averaging is statistically flawed as it underestimates the density in void interiors. We provide two alternative methods that do not suffer from this effect; one based on Voronoi tessellations is also easily able to account from artefacts due to finite survey boundaries and so is more suitable when comparing simulation data to observation. Using this method we show that voids in simulation are exactly self-similar, meaning that their avera...

  11. Development of Fuzzy Logic System to Predict the SAW Weldment Shape Profiles

    Institute of Scientific and Technical Information of China (English)

    H.K.Narang; M.M.Mahapatra; P.K.Jha; P.Biswas

    2012-01-01

    A fuzzy model was presented to predict the weldment shape profile of submerged arc welds (SAW)including the shape of heat affected zone (HAZ).The SAW bead-on-plates were welded by following a full factorial design matrix.The design marx consisted of three levels of input welding process parameters.The welds were cross-sectioned and etched,and the zones were measured.A mapping technique was used to measure the various segments of the weld zones.These mapped zones were used to build a fuzzy logic model.The membership functions of the fuzzy model were chosen for the accurate prediction of the weld zone.The fuzzy model was further tested for a set of test case data.The weld zone predicted by the fuzzy logic model was compared with the experimentally obtained shape profiles and close agreement between the two was noted.The mapping technique developed for the weld zones and the fuzzy logic model can be used for on-line control of the SAW process.From the SAW fuzzy logic model an estimation of the fusion and HAZ can also be developed.

  12. T-shaped competency profile for water professionals of the future

    Science.gov (United States)

    Uhlenbrook, S.; de Jong, E.

    2012-10-01

    Global environmental changes introduce new challenges and expose future university graduates in hydrology and related fields to problems of unprecedented complexity and magnitude. The T-shape model is proposed as a generic competency profile guiding the design of university curricula. This model differentiates between cognitive competencies in a certain field (i.e. hydrology; vertical leg of the T), and other cognitive/knowledge competencies in neighboring fields (e.g. hydraulics, aquatic ecology, land use management etc.) and functional, personal and values competencies and meta-competencies (all summarized in the horizontal bar of the T). It is based on the holistic model of professional competencies by Cheetham and Chivers (1996) and related studies (Oskam, 2009). The T-shape profile should apply to all levels of higher education (1st degree till doctorate level) in hydrology and related fields. For the effectiveness of hydrologists as professionals, a variable mix of competencies is required and further discussed. Key aspects are an open attitude for learning, continuous professional development (lifelong learning), and integrative and team working skills. Furthermore, a stimulating learning environment that promotes active learning is essential. As examples that substantiate the proposed T-shape model, the post-graduate education programmes of UNESCO-IHE and the main outcomes from a university curriculum workshop to promote education for sustainable development are introduced.

  13. Estimation of AFM tip shape and status in linewidth and profile measurement.

    Science.gov (United States)

    Han, Guoqiang; Jiang, Zhuangde; Jing, Weixuan; Prewett, Philip D; Jiang, Kyle

    2011-12-01

    An atomic force microscopy image is a dilation of the specimen surface with the probe tip. Tips wear or are damaged as they are used. And AFM tip shape and position status make AFM images distorted. So it is necessary to characterize AFM tip shape and position parameters so as to reconstruct AFM images. A geometric model-based approach is presented to estimate AFM tip shape and position status by AFM images of test specimens and scanning electron microscope (SEM) images of AFM tip. In this model, the AFM tip is characterized by using a dynamic cone model. The geometric relationship between AFM tip and the sample structure is revealed in linewidth and profile measurement. The method can easily calculate the tip parameters including half-cone angle, installation angle, scanning tilting angle and curvature radius, and easily estimate the position status of AFM tip when AFM tip moves on the specimen. The results of linewidth and profile measurement are amended accurately through this approach.

  14. Slope gradient and shape effects on soil profiles in the northern mountainous forests of Iran

    Science.gov (United States)

    Fazlollahi Mohammadi, M.; Jalali, S. G. H.; Kooch, Y.; Said-Pullicino, D.

    2016-12-01

    In order to evaluate the variability of the soil profiles at two shapes (concave and convex) and five positions (summit, shoulder, back slope, footslope and toeslope) of a slope, a study of a virgin area was made in a Beech stand of mountain forests, northern Iran. Across the slope positions, the soil profiles demonstrated significant changes due to topography for two shape slopes. The solum depth of the convex slope was higher than the concave one in all five positions, and it decreased from the summit to shoulder and increased from the mid to lower slope positions for both convex and concave slopes. The thin solum at the upper positions and concave slope demonstrated that pedogenetic development is least at upper slope positions and concave slope where leaching and biomass productivity are less than at lower slopes and concave slope. A large decrease in the thickness of O and A horizons from the summit to back slope was noted for both concave and convex slopes, but it increased from back slope toward down slope for both of them. The average thickness of B horizons increased from summit to down slopes in the case of the concave slope, but in the case of convex slope it decreased from summit to shoulder and afterwards it increased to the down slope. The thicknesses of the different horizons varied in part in the different positions and shape slopes because they had different plant species cover and soil features, which were related to topography.

  15. T-shaped competency profile for water professionals of the future

    Directory of Open Access Journals (Sweden)

    S. Uhlenbrook

    2012-03-01

    Full Text Available Global environmental changes expose future university graduates in hydrology and related fields to problems of unprecedented complexity and magnitude. The T-shape model is proposed as a generic competency profile guiding the design of university curricula. This model differentiates between cognitive competencies in a certain field, (i.e. hydrology; vertical leg of the T other cognitive/knowledge competencies in neighboring fields (e.g. hydraulics, aquatic ecology, land use management etc. and functional, personal and values competencies and meta-competencies (horizontal bar of the T. It is based on the holistic model of professional competencies by Cheetham and Chivers (1996 and related studies (Oskam, 2009. The T-shape profile should apply to all levels of higher education (1st degree till doctorate level in hydrology and related fields. For the effectiveness of hydrologists as professionals a variable mix of competencies is required and further discussed. Key aspects are an open attitude for learning, continuous professional development (life long learning, and integrative and team working skills. Furthermore, a stimulating learning environment that promotes active learning is essential. As examples that substantiate the proposed T-shape model, the post-graduate education programmes of UNESCO-IHE and the main outcomes from a university curriculum workshop to promote education for sustainable development are introduced.

  16. T-shaped competency profile for water professionals of the future

    Directory of Open Access Journals (Sweden)

    S. Uhlenbrook

    2012-10-01

    Full Text Available Global environmental changes introduce new challenges and expose future university graduates in hydrology and related fields to problems of unprecedented complexity and magnitude. The T-shape model is proposed as a generic competency profile guiding the design of university curricula. This model differentiates between cognitive competencies in a certain field (i.e. hydrology; vertical leg of the T, and other cognitive/knowledge competencies in neighboring fields (e.g. hydraulics, aquatic ecology, land use management etc. and functional, personal and values competencies and meta-competencies (all summarized in the horizontal bar of the T. It is based on the holistic model of professional competencies by Cheetham and Chivers (1996 and related studies (Oskam, 2009. The T-shape profile should apply to all levels of higher education (1st degree till doctorate level in hydrology and related fields. For the effectiveness of hydrologists as professionals, a variable mix of competencies is required and further discussed. Key aspects are an open attitude for learning, continuous professional development (lifelong learning, and integrative and team working skills. Furthermore, a stimulating learning environment that promotes active learning is essential. As examples that substantiate the proposed T-shape model, the post-graduate education programmes of UNESCO-IHE and the main outcomes from a university curriculum workshop to promote education for sustainable development are introduced.

  17. Density and impurity profile behaviours in HL-2A tokamak with different gas fuelling methods

    Institute of Scientific and Technical Information of China (English)

    Cui Zheng-Ying; Zhou Yan; Li Wei; Feng Bei-Bin; Sun Ping; Dong Chun-Feng; Liu Yi; Hong Wen-Yu; Yang Qing-Wei; Ding Xuan-Tong; Duan Xu-Ru

    2009-01-01

    The electron density profile peaking and the impurity accumulation in the HL-2A tokamak plasma are observed when three kinds of fuelling methods are separately used at different fuelling particle locations.The density profile becomes more peaked when the line-averaged electron density approaches the Greenwald density limit nG and,consequently,impurity accumulation is often observed.A linear increase regime in the density range ne<0.6nG and a saturation regime in ne>0.6nG are obtained.There is no significant difference in achieved density peaking factor fne between the supersonic molecular beam injection (SMBI) and gas puffing into the plasma main chamber.However,the achieved fne is relatively low,in particular,in the case of density below 0.7nG,when the working gas is puffed into the divertor chamber.A discharge with a density as high as 1.2nG,i.e.ne=1.2nG,can be achieved by SMBI just after siliconization as a wall conditioning.The metallic impurities,such as iron and chromium,also increase remarkably when the impurity accumulation happens.The mechanism behind the density peaking and impurity accumulation is studied by investigating both the density peaking factor versus the effective collisionality and the radiation peaking versus density peaking.

  18. Sliding-mode control design for nonlinear systems using probability density function shaping.

    Science.gov (United States)

    Liu, Yu; Wang, Hong; Hou, Chaohuan

    2014-02-01

    In this paper, we propose a sliding-mode-based stochastic distribution control algorithm for nonlinear systems, where the sliding-mode controller is designed to stabilize the stochastic system and stochastic distribution control tries to shape the sliding surface as close as possible to the desired probability density function. Kullback-Leibler divergence is introduced to the stochastic distribution control, and the parameter of the stochastic distribution controller is updated at each sample interval rather than using a batch mode. It is shown that the estimated weight vector will converge to its ideal value and the system will be asymptotically stable under the rank-condition, which is much weaker than the persistent excitation condition. The effectiveness of the proposed algorithm is illustrated by simulation.

  19. A molecular heterojunction of zinc phthalocyanine and peanut-shaped fullerene polymer: A density functional study

    Science.gov (United States)

    Tanikawa, Kousei; Ohno, Kaoru; Noda, Yusuke; Ono, Shota; Kuwahara, Riichi; Takashima, Akito; Nakaya, Masato; Onoe, Jun

    2017-10-01

    We have performed first-principles density functional calculations of a molecular heterojunction of a zinc phthalocyanine (ZnPc) molecule and a peanut-shaped fullerene polymer (PSFP) made from several coalesced cross-linked C60 molecules. The PSFP has many isomers and all have both spatially localized (near ZnPc) and metallic conducting levels. Here we consider four typical isomers. From the resulting electronic structure, we discuss the applicability of these isomers to organic photovoltaics (OPV), electrodes, and light harvesting materials. If one of the isomers called T3, which has the largest energy gap, is used together with ZnPc for OPV, this system shows more than 20% energy conversion efficiency.

  20. Variability of O3 and NO2 profile shapes during DISCOVER-AQ: Implications for satellite observations and comparisons to model-simulated profiles

    Science.gov (United States)

    Flynn, Clare Marie; Pickering, Kenneth E.; Crawford, James H.; Weinheimer, Andrew J.; Diskin, Glenn; Thornhill, K. Lee; Loughner, Christopher; Lee, Pius; Strode, Sarah A.

    2016-12-01

    To investigate the variability of in situ profile shapes under a variety of meteorological and pollution conditions, results are presented of an agglomerative hierarchical cluster analysis of the in situ O3 and NO2 profiles for each of the four campaigns of the NASA DISCOVER-AQ mission. Understanding the observed profile variability for these trace gases is useful for understanding the accuracy of the assumed profile shapes used in satellite retrieval algorithms as well as for understanding the correlation between satellite column observations and surface concentrations. The four campaigns of the DISCOVER-AQ mission took place in Maryland during July 2011, the San Joaquin Valley of California during January-February 2013, the Houston, Texas, metropolitan region during September 2013, and the Denver-Front Range region of Colorado during July-August 2014. Several distinct profile clusters emerged for the California, Texas, and Colorado campaigns for O3, indicating significant variability of O3 profile shapes, while the Maryland campaign presented only one distinct O3 cluster. In contrast, very few distinct profile clusters emerged for NO2 during any campaign for this particular clustering technique, indicating the NO2 profile behavior was relatively uniform throughout each campaign. However, changes in NO2 profile shape were evident as the boundary layer evolved through the day, but they were apparently not significant enough to yield more clusters. The degree of vertical mixing (as indicated by temperature lapse rate) associated with each cluster exerted an important influence on the shapes of the median cluster profiles for O3, as well as impacted the correlations between the associated column and surface data for each cluster for O3. The correlation analyses suggest satellites may have the best chance to relate to surface O3 under the conditions encountered during the Maryland campaign Clusters 1 and 2, which include deep, convective boundary layers and few

  1. Modelling the pultrusion process of an industrial L-shaped composite profile

    DEFF Research Database (Denmark)

    Baran, Ismet; Akkerman, Remko; Hattel, Jesper Henri

    2014-01-01

    A numerical process simulation tool is developed for the pultrusion of an industrial L-shaped profile. The composite contains the combination of uni-directional (UD) roving and continuous filament mat (CFM) layers impregnated by a polyester resin system specifically prepared for the process...... model predicts the residual spring-in angle which is found to be close to the one measured from the real pultruded L-shaped products. The residual spring-in angle is further analyzed using the developed simulation tool for different pulling rates. Through-thickness stress variations are found to prevail...... inside the part such that the UD and CFM layers have different stress levels at the end of the process. The predicted stress pattern is verified by performing a stress calculation using the classical laminate theory (CLT)....

  2. Discovery of directional and nondirectional pioneer transcription factors by modeling DNase profile magnitude and shape.

    Science.gov (United States)

    Sherwood, Richard I; Hashimoto, Tatsunori; O'Donnell, Charles W; Lewis, Sophia; Barkal, Amira A; van Hoff, John Peter; Karun, Vivek; Jaakkola, Tommi; Gifford, David K

    2014-02-01

    We describe protein interaction quantitation (PIQ), a computational method for modeling the magnitude and shape of genome-wide DNase I hypersensitivity profiles to identify transcription factor (TF) binding sites. Through the use of machine-learning techniques, PIQ identified binding sites for >700 TFs from one DNase I hypersensitivity analysis followed by sequencing (DNase-seq) experiment with accuracy comparable to that of chromatin immunoprecipitation followed by sequencing (ChIP-seq). We applied PIQ to analyze DNase-seq data from mouse embryonic stem cells differentiating into prepancreatic and intestinal endoderm. We identified 120 and experimentally validated eight 'pioneer' TF families that dynamically open chromatin. Four pioneer TF families only opened chromatin in one direction from their motifs. Furthermore, we identified 'settler' TFs whose genomic binding is principally governed by proximity to open chromatin. Our results support a model of hierarchical TF binding in which directional and nondirectional pioneer activity shapes the chromatin landscape for population by settler TFs.

  3. High hydrostatic pressure specifically affects molecular dynamics and shape of low-density lipoprotein particles

    Science.gov (United States)

    Golub, M.; Lehofer, B.; Martinez, N.; Ollivier, J.; Kohlbrecher, J.; Prassl, R.; Peters, J.

    2017-04-01

    Lipid composition of human low-density lipoprotein (LDL) and its physicochemical characteristics are relevant for proper functioning of lipid transport in the blood circulation. To explore dynamical and structural features of LDL particles with either a normal or a triglyceride-rich lipid composition we combined coherent and incoherent neutron scattering methods. The investigations were carried out under high hydrostatic pressure (HHP), which is a versatile tool to study the physicochemical behavior of biomolecules in solution at a molecular level. Within both neutron techniques we applied HHP to probe the shape and degree of freedom of the possible motions (within the time windows of 15 and 100 ps) and consequently the flexibility of LDL particles. We found that HHP does not change the types of motion in LDL, but influences the portion of motions participating. Contrary to our assumption that lipoprotein particles, like membranes, are highly sensitive to pressure we determined that LDL copes surprisingly well with high pressure conditions, although the lipid composition, particularly the triglyceride content of the particles, impacts the molecular dynamics and shape arrangement of LDL under pressure.

  4. The effect of baryons on the inner density profiles of rich clusters

    CERN Document Server

    Schaller, Matthieu; Bower, Richard G; Theuns, Tom; Trayford, James; Crain, Robert A; Furlong, Michelle; Schaye, Joop; Vecchia, Claudio Dalla; McCarthy, I G

    2014-01-01

    We use the "Evolution and assembly of galaxies and their environment" (EAGLE) cosmological simulation to investigate the effect of baryons on the density profiles of rich galaxy clusters. We focus on the six most massive EAGLE clusters ($M_{200} > 10^{14}M_\\odot$) which can be compared with a recent analysis of seven real clusters by Newman et al. The central brightest cluster galaxies (BCGs) in EAGLE have steep stellar density profiles, $\\rho_*(r) \\propto r^{-3}$. Stars dominate the mass density for $r < 10~{\\rm kpc}$, and, as a result, the total mass density profiles are steeper than the Navarro-Frenk-White (NFW) profile. However, the dark matter halo itself closely follows the NFW form at all resolved radii ($r\\gtrsim3.0~{\\rm kpc}$). The \\eagle BCGs have similar surface brightness and line-of-sight velocity dispersion profiles as the BCGs observed by Newmanet al. The central slopes of the total mass profiles are also consistent with the observed clusters. However, after subtracting the contribution of t...

  5. Determination of the vertical electron-density profile in ionospheric tomography: experimental results

    Directory of Open Access Journals (Sweden)

    C. N. Mitchell

    Full Text Available The reconstruction of the vertical electron-density profile is a fundamental problem in ionospheric tomography. Lack of near-horizontal ray paths limits the information available on the vertical profile, so that the resultant image of electron density is biased in a horizontal sense. The vertical profile is of great importance as it affects the authenticity of the entire tomographic image. A new method is described whereby the vertical profile is selected using relative total-electron-content measurements. The new reconstruction process has been developed from modelling studies. A range of background ionospheres, representing many possible peak heights, scale heights and electron densities are formed from a Chapman profile on the bottomside with a range of topside profiles. The iterative reconstruction process is performed on all of these background ionospheres and a numerical selection criterion employed to select the final image. The resulting tomographic images show excellent agreement in electron density when compared with independent verification provided by the EISCAT radar.

  6. Density profiles of dark matter halos in an improved Secondary Infall model

    CERN Document Server

    Del Popolo, A; Recami, E; Spedicato, E

    2000-01-01

    In this paper we calculate the density profiles of virialized halos both in the case of structure evolving hierarchically from a scale-free Gaussian delta-field having a power spectrum P(k)=A k^n in a Omega=1 Universe and in the case of the CDM model, by using a modified version of Hoffman & Shaham's (1985) (hereafter HS) and Hoffman's (1988) model. We suppose that the initial density contrast profile around local maxima is given by the mean peak profile introduced by Bardeen et al. (1986) (hereafter BBKS), and is not just proportional to the two-point correlation function, as assumed by HS. We show that the density profiles, both for scale-free Universes and the CDM model, are not power-laws but have a logarithmic slope that increases from the inner halo to its outer parts. Both scale-free, for n >=-1, and CDM density profiles are well approximated by Navarro et al. (1995, 1996, 1997) profile. The radius a, at which the slope alpha=-2, is a function of the mass of the halo and in the scale-free models al...

  7. Reconstruction of edge density profiles on Large Helical Device using ultrashort-pulse reflectometry.

    Science.gov (United States)

    Yokota, Yuya; Mase, Atsushi; Kogi, Yuichiro; Tokuzawa, Tokihiko; Kawahata, Kazuo; Nagayama, Yoshio; Hojo, Hitoshi

    2008-10-01

    Reflectometry has been expected to be one of the key diagnostics to measure density profiles. We have applied an ultrashort-pulse reflectometry (USPR) system to Large Helical Device in the National Institute for Fusion Science. Wide frequency band system is required to obtain wide density profile since an incident wave is reflected at the density layer corresponding to its cutoff frequency. The reflectometry utilizes an impulse with less than 30 ps pulse width as a source. Since the bandwidth of an impulse has an inverse relation to the pulse width, we can cover the frequency range of micro- to millimeter waves (18-40 GHz) with a single source. The density profiles can be reconstructed by collecting time-of-flight (TOF) signals for each frequency component of an impulse reflected from the corresponding cutoff layer. We utilize the signal record analysis (SRA) method to reconstruct the density profiles from the TOF signal. The effectiveness of the SRA method for the profile reconstruction is confirmed by a simulation study of the USPR using a finite-difference time domain method.

  8. Application specific beam profiles: new surface and thin-film refinement processes using beam shaping technologies

    Science.gov (United States)

    Hauschild, Dirk

    2017-02-01

    Today, the use of laser photons for materials processing is a key technology in nearly all industries. Most of the applications use circular beam shapes with Gaussian intensity distribution that is given by the resonator of the laser or by the power delivery via optical fibre. These beam shapes can be typically used for material removal with cutting or drilling and for selective removal of material layers with ablation processes. In addition to the removal of materials, it is possible to modify and improve the material properties in case the dose of laser photons and the resulting light-material interaction addresses a defined window of energy and dwell-time. These process windows have typically dwell-times between µs and s because of using sintering, melting, thermal diffusion or photon induced chemical and physical reaction mechanisms. Using beam shaping technologies the laser beam profiles can be adapted to the material properties and time-temperature and the space-temperature envelopes can be modified to enable selective annealing or crystallization of layers or surfaces. Especially the control of the process energy inside the beam and at its edges opens a large area of laser applications that can be addressed only with an optimized spatial and angular beam profile with down to sub-percent intensity variation used in e.g. immersion lithography tools with ArF laser sources. LIMO will present examples for new beam shapes and related material refinement processes even on large surfaces and give an overview about new mechanisms in laser material processing for current and coming industrial applications.

  9. Seasonal Variations In Density Profiles And Densification Process At Mts. Logan And Wrangell

    Science.gov (United States)

    Kanamori, S.; Shiraiwa, T.; Goto-Azuma, K.; Benson, C. S.; Naruse, R.

    2004-12-01

    Detailed density measurements were carried out for ice cores which were drilled at Mt. Logan (60° 35'20"N, 140° 36'15"W; 4135m a.s.l.; Shiraiwa et al., 2003) and Mt. Wrangell (62° 00'N, 140° 03'W; 4100m a.s.l.; Shiraiwa et al., 2004). The detailed density profiles show periodic fluctuations which seem to indicate seasonal cycles. In Mt. Logan, the number of annual layers which are estimated from the density profile agrees well with that estimated from the oxygen isotope data (Goto-Azuma et al., 2003) and the age of the ice core estimated from tritium peaks. On the other hand, in Mt. Wrangell, the number of annual layers from the density profile is quite different from that of the hydrogen isotope profile. The accumulation time series reconstructed from the density profile in Mt. Wrangell shows significant correlations with precipitation data of weather stations that locate near Mt. Wrangell. Accumulation rate and mean annual temperature at both sites are estimated to be almost the same (Benson & Motyka, 1978; Shiraiwa et al., 2003; Goto-Azuma et al., 2003; Shiraiwa et al., 2004). However, their firn/ice transition depths (Mt. Logan: 50m, Mt. Wrangell: 90m) are considerably different. This difference cannot be explained only from the difference in initial densities. Densification rate in Mt. Logan is higher than in Mt. Wrangell, i.e. compactive viscosity coefficient calculated from depth-density profile in Mt. Wrangell is more than double of the value in Mt. Logan.

  10. Modelling profile and shape evolution during hot rolling of steel strip

    Directory of Open Access Journals (Sweden)

    Zambrano, P. C.

    2006-10-01

    Full Text Available Profile and shape control are required to assure the dimensional quality of rolled strip. Occurrence of waves either at the edges or centre of strips is attributed to inconsistency between the entry and exit cross-section profiles of the stock within a given rolling pass. The exit profile of the strip can be computed by considering that the such profile is the complement of that of the roll-gap, which is affected by wear, thermal expansion and distortion of the work rolls A computer model was developed to predict the profile of the roll-gap taking into account the thermal gradient within the work roll and the distortion caused by the acting forces. It was possible to establish a good correlation between the profiles of strips obtained from trials carried out on site, and the predictions of the model. The model allows for the prediction of the onset of shape defects from changes in the profile of rolled strips.

    Se requiere del control del perfil y forma para asegurar la calidad dimensional de la cinta laminada. La presencia de ondulaciones, ya sea en la orilla o al centro de la cinta, se atribuye a la inconsistencia entre el perfil de la sección transversal de la pieza a la entrada y a la salida, en un dado paso. El perfil de salida de la cinta se puede calcular al suponer que dicho perfil es el complemento del entrehierro, que es afectado por desgaste, expansión térmica y distorsión de los rodillos de trabajo. Un modelo matemático se desarrolló para predecir el perfil del entrehierro tomando en cuenta el gradiente térmico en el rodillo de trabajo y la distorsión producida por las fuerzas actuantes. Fue posible encontrar una buena correlación entre los perfiles de cintas obtenidos a partir de pruebas en planta y las predicciones del modelo. El modelo permite predecir el origen de defectos de forma a partir de cambios en el perfil de cintas laminadas.

  11. Earth-mass haloes and the emergence of NFW density profiles

    CERN Document Server

    Angulo, Raul E; Ludlow, Aaron; Bonoli, Silvia

    2016-01-01

    We report results from simulations of neutralino dark matter ($\\chi$DM) haloes. We follow them from their emergence at one earth mass to a final mass of a few percent solar. We show that the density profiles of the first haloes are well described by a $\\sim r^{-1.5}$ power-law. As haloes grow in mass, their density profiles evolve significantly. In the central regions, they become shallower and reach on average $\\sim r^{-1}$, the asymptotic form of an NFW profile. However, the profile of individual haloes can show non-monotonic density slopes, and be shallower than $-1$ in some cases. We investigate the transformation of cuspy power-law profiles using a series of non-cosmological simulations of equal-mass mergers. Contrary to previous findings, we observe that temporal variations in the gravitational potential caused by mergers lead to a shallowing of the inner profile, an effect which is stronger for shallower initial profiles and for mergers that involve a higher number of systems. Depending on the merger d...

  12. Limits on the power-law mass and luminosity density profiles of elliptical galaxies from gravitational lensing systems

    CERN Document Server

    Cao, Shuo; Yao, Meng; Zhu, Zong-Hong

    2016-01-01

    We use 118 strong gravitational lenses observed by the SLACS, BELLS, LSD and SL2S surveys to constrain the total mass profile and the profile of luminosity density of stars (light-tracers) in elliptical galaxies up to redshift $z \\sim 1$. Assuming power-law density profiles for the total mass density, $\\rho=\\rho_0(r/r_0)^{-\\alpha}$, and luminosity density, $\

  13. TEMPERATURE AND ELECTRON DENSITY DIAGNOSTICS OF A CANDLE-FLAME-SHAPED FLARE

    Energy Technology Data Exchange (ETDEWEB)

    Guidoni, S. E. [NASA Goddard Space Flight Center/CUA, Code 674, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); McKenzie, D. E.; Longcope, D. W.; Yoshimura, K. [Department of Physics, Montana State University, Bozeman, MT 59717-3840 (United States); Plowman, J. E., E-mail: silvina.e.guidoni@nasa.gov [High Altitude Observatory, National Center for Atmospheric Research P.O. Box 3000, Boulder, CO 80307-3000 (United States)

    2015-02-10

    Candle-flame-shaped flares are archetypical structures that provide indirect evidence of magnetic reconnection. A flare resembling Tsuneta's famous 1992 candle-flame flare occurred on 2011 January 28; we present its temperature and electron density diagnostics. This flare was observed with Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA), Hinode/X-Ray Telescope (XRT), and Solar Terrestrial Relations Observatory Ahead (STEREO-A)/Extreme Ultraviolet Imager, resulting in high-resolution, broad temperature coverage, and stereoscopic views of this iconic structure. The high-temperature images reveal a brightening that grows in size to form a tower-like structure at the top of the posteruption flare arcade, a feature that has been observed in other long-duration events. Despite the extensive work on the standard reconnection scenario, there is no complete agreement among models regarding the nature of this high-intensity elongated structure. Electron density maps reveal that reconnected loops that are successively connected at their tops to the tower develop a density asymmetry of about a factor of two between the two legs, giving the appearance of ''half-loops''. We calculate average temperatures with a new fast differential emission measure (DEM) method that uses SDO/AIA data and analyze the heating and cooling of salient features of the flare. Using STEREO observations, we show that the tower and the half-loop brightenings are not a line-of-sight projection effect of the type studied by Forbes and Acton. This conclusion opens the door for physics-based explanations of these puzzling, recurrent solar flare features, previously attributed to projection effects. We corroborate the results of our DEM analysis by comparing them with temperature analyses from Hinode/XRT.

  14. Modifications of plasma density profile and thrust by neutral injection in a helicon plasma thruster

    Science.gov (United States)

    Takahashi, Kazunori; Takao, Yoshinori; Ando, Akira

    2016-11-01

    Argon propellant is introduced from the upstream and downstream sides of a high power helicon plasma thruster. The plasma density profile and the imparted thrust are measured for various upstream and downstream argon flow rates, where the total gas flow rate of 70 sccm and the resultant vacuum chamber pressure of 0.2 mTorr are maintained. It is observed that the imparted thrust increases with an increase in the downstream gas flow rate; simultaneously an upstream-peaking profile of the plasma density observed for the upstream gas injection becomes uniform for the downstream gas injection. The difference in the thrust between the upstream and downstream gas injections is enhanced by increasing the rf power. The observed density profiles are qualitatively consistent with theoretical predictions taking a neutral depletion effect into account.

  15. Near-exponential surface densities as hydrostatic, non-equilibrium profiles in galaxy discs

    Science.gov (United States)

    Struck, Curtis; Elmegreen, Bruce G.

    2017-01-01

    Apparent exponential surface density profiles are nearly universal in galaxy discs across Hubble types, over a wide mass range, and a diversity of gravitational potential forms. Several processes have been found to produce exponential profiles, including the actions of bars and spirals, and clump scattering, with star scattering a common theme in these. Based on reasonable physical constraints, such as minimal entropy gradients, we propose steady-state distribution functions for disc stars, applicable over a range of gravitational potentials. The resulting surface density profiles are generally a power-law term times a Sérsic-type exponential. Over a modest range of Sérsic index values, these profiles are often indistinguishable from Type I exponentials, except at the innermost radii. However, in certain parameter ranges, these steady states can appear as broken, Type II or III profiles. The corresponding velocity dispersion profiles are low-order power laws. A chemical potential associated with scattering can help understand the effects of long-range scattering. The steady profiles are found to persist through constant velocity expansions or contractions in evolving discs. The proposed distributions and profiles are simple and solve the stellar hydrodynamic equations. They may be especially relevant to thick discs that have settled to a steady form via scattering.

  16. Mass, velocity anisotropy and pseudo phase space density profiles of Abell 2142

    CERN Document Server

    Munari, Emiliano; Mamon, Gary

    2013-01-01

    Aim: We aim to compute the mass and velocity anisotropy profiles of Abell 2142 and, from there, the pseudo phase space density profile $Q(r)$ and the density slope - velocity anisotropy $\\beta - \\gamma$ relation, and compare them with theoretical expectations. Methods: The mass profiles have been obtained by using three techniques based on member galaxy kinematics, namely the caustic method, the method of Dispersion - Kurtosis and MAMPOSSt. Through the inversion of the Jeans equation it has been possible to compute the velocity anisotropy profiles. Results: The mass profiles, as well as the virial values of mass and radius, computed with the different techniques are in agreement with one another and with the estimates coming from X-ray and weak lensing studies. A concordance mass profile is obtained by averaging the lensing, X-ray and kinematics determinations. The cluster mass profile is well fit by an NFW profile with $c=4.0 \\pm 0.5$. The population of red and blue galaxies appear to have a different veloci...

  17. Nonsingular density profiles of dark matter halos and Strong gravitational lensing

    CERN Document Server

    Chen, D M

    2005-01-01

    We use the statistics of strong gravitational lenses to investigate whether the mass profiles with a flat density core are supported. The probability for lensing by halos modeled by nonsingular truncated isothermal sphere (NTIS) with image separations greater than a certain value (ranges from zero to ten arcseconds) is calculated. NTIS is an analytical model for the postcollapse equilibrium structure of virialized objects derived by Shapiro, Iliev & Raga (1999). This profile has a soft core and matches quite well with the mass profiles of dark matter dominated dwarf galaxies deduced from their observed rotation curves. It also agrees well with NFW (Navarro, Frenk & White) at all radii outside of a few NTIS core radii. Unfortunately, compared the results with those for singular lensing halos (NFW and SIS+NFW) and strong lensing observations, the probabilities for lensing by NTIS halos are far too low. While this result is valid for any other nonsingular density profiles (with a large core radius), we c...

  18. Demographic models reveal the shape of density dependence for a specialist insect herbivore on variable host plants.

    Science.gov (United States)

    Miller, Tom E X

    2007-07-01

    1. It is widely accepted that density-dependent processes play an important role in most natural populations. However, persistent challenges in our understanding of density-dependent population dynamics include evaluating the shape of the relationship between density and demographic rates (linear, concave, convex), and identifying extrinsic factors that can mediate this relationship. 2. I studied the population dynamics of the cactus bug Narnia pallidicornis on host plants (Opuntia imbricata) that varied naturally in relative reproductive effort (RRE, the proportion of meristems allocated to reproduction), an important plant quality trait. I manipulated per-plant cactus bug densities, quantified subsequent dynamics, and fit stage-structured models to the experimental data to ask if and how density influences demographic parameters. 3. In the field experiment, I found that populations with variable starting densities quickly converged upon similar growth trajectories. In the model-fitting analyses, the data strongly supported a model that defined the juvenile cactus bug retention parameter (joint probability of surviving and not dispersing) as a nonlinear decreasing function of density. The estimated shape of this relationship shifted from concave to convex with increasing host-plant RRE. 4. The results demonstrate that host-plant traits are critical sources of variation in the strength and shape of density dependence in insects, and highlight the utility of integrated experimental-theoretical approaches for identifying processes underlying patterns of change in natural populations.

  19. Gravitational Lens Recovery with GLASS: Measuring the mass profile and shape of a lens

    CERN Document Server

    Coles, Jonathan P; Saha, Prasenjit

    2014-01-01

    We use a new non-parametric gravitational modelling tool -- GLASS -- to determine what quality of data (strong lensing, stellar kinematics, and/or stellar masses) are required to measure the circularly averaged mass profile of a lens and its shape. GLASS uses an under-constrained adaptive grid of mass pixels to model the lens, searching through thousands of models to marginalise over model uncertainties. Our key findings are as follows: (i) for pure lens data, multiple sources with wide redshift separation give the strongest constraints as this breaks the well-known mass-sheet or steepness degeneracy; (ii) a single quad with time delays also performs well, giving a good recovery of both the mass profile and its shape; (iii) stellar masses -- for lenses where the stars dominate the central potential -- can also break the steepness degeneracy, giving a recovery for doubles almost as good as having a quad with time delay data, or multiple source redshifts; (iv) stellar kinematics provide a robust measure of the ...

  20. Avalanche consumption and the stationary regions of the density profile around the droplets in the theory of condensation

    OpenAIRE

    Kurasov, V.

    1998-01-01

    The contradiction between the stationary aproach to the density profile and the avalanche character of the metastable phase consumption is investigated. The exact solution for the metastable phase profile is obtained. The reconsidered value for the special parameter responsible for the hierarchy in the structure of the density profile around the droplet is presented.

  1. Neutrals density profiles in EXTRAP-T2R based on Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Cecconello, M

    2002-07-01

    The role of neutral particles in fusion plasmas is very important affecting several aspects of the discharge properties. In particular the neutrals affect the particle and energy balance, the plasma confinement properties, the density profile, the particle and energy fluxes at the wall and the wall erosion. In addition, highly energetic neutrals are used as a diagnostic of the plasma ion temperature. This report describes MCNC a Monte Carlo code used in EXTRAP T2R for the calculation of the neutrals density profile of hydrogen plasma.

  2. Interplay between density profile and zonal flows in drift kinetic simulations of slab ITG turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Sarazin, Y.; Garbet, X.; Grandgirard, V.; Ghendrih, Ph. [Association Euratom-CEA Cadarache (DSM/DRFC), 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Bertrand, P. [Universite Henri Poincare, Laboratoire de Physique des Milieux Ionises et Applications (LPMIA), 54 - Vandoeuvre les Nancy (France); Besse, N.; Sonnendruecker, E. [Universite Louis Pasteur, CNRS IRMA, 67 - Strasbourg (France)

    2004-07-01

    This paper reports on 4-dimensional drift kinetic simulations of the slab branch of the Ion Temperature Gradient driven turbulence in a cylinder. In the non-linear regime, the system is found to relax preferentially either via heat transport or via mean sheared flows, depending on the density profile. A strong density gradient appears to be stabilizing both linearly, by increasing the instability threshold, and non linearly, by activating sheared flows. This impedes the relaxation of the profiles and sustains a pressure transport barrier. (authors)

  3. A phenomenological model of the muon density profile on the ground of very inclined air showers

    Science.gov (United States)

    Dembinski, H. P.; Billoir, P.; Deligny, O.; Hebbeker, T.

    2010-09-01

    Ultra-high energy cosmic rays generate extensive air showers in Earth's atmosphere. A standard approach to reconstruct the energy of an ultra-high energy cosmic rays is to sample the lateral profile of the particle density on the ground of the air shower with an array of surface detectors. For cosmic rays with large inclinations, this reconstruction is based on a model of the lateral profile of the muon density observed on the ground, which is fitted to the observed muon densities in individual surface detectors. The best models for this task are derived from detailed Monte-Carlo simulations of the air shower development. We present a phenomenological parametrization scheme which allows to derive a model of the average lateral profile of the muon density directly from a fit to a set of individual Monte-Carlo simulated air showers. The model reproduces the detailed simulations with a high precision. As an example, we generate a muon density model which is valid in the energy range 10 18 eV < E < 10 20 eV and the zenith angle range 60°<θ<90°. We will further demonstrate a way to speed up the simulation of such muon profiles by three orders of magnitude, if only the muons in the shower are of interest.

  4. Fuzzy electron density fragments in macromolecular quantum chemistry, combinatorial quantum chemistry, functional group analysis, and shape-activity relations.

    Science.gov (United States)

    Mezey, Paul G

    2014-09-16

    Conspectus Just as complete molecules have no boundaries and have "fuzzy" electron density clouds approaching zero density exponentially at large distances from the nearest nucleus, a physically justified choice for electron density fragments exhibits similar behavior. Whereas fuzzy electron densities, just as any fuzzy object, such as a thicker cloud on a foggy day, do not lend themselves to easy visualization, one may partially overcome this by using isocontours. Whereas a faithful representation of the complete fuzzy density would need infinitely many such isocontours, nevertheless, by choosing a selected few, one can still obtain a limited pictorial representation. Clearly, such images are of limited value, and one better relies on more complete mathematical representations, using, for example, density matrices of fuzzy fragment densities. A fuzzy density fragmentation can be obtained in an exactly additive way, using the output from any of the common quantum chemical computational techniques, such as Hartree-Fock, MP2, and various density functional approaches. Such "fuzzy" electron density fragments properly represented have proven to be useful in a rather wide range of applications, for example, (a) using them as additive building blocks leading to efficient linear scaling macromolecular quantum chemistry computational techniques, (b) the study of quantum chemical functional groups, (c) using approximate fuzzy fragment information as allowed by the holographic electron density theorem, (d) the study of correlations between local shape and activity, including through-bond and through-space components of interactions between parts of molecules and relations between local molecular shape and substituent effects, (e) using them as tools of density matrix extrapolation in conformational changes, (f) physically valid averaging and statistical distribution of several local electron densities of common stoichiometry, useful in electron density databank mining, for

  5. Effects of Mean Flow Profiles on Instability of a Low-Density Gas Jet Injected into a High-Density Gas

    Science.gov (United States)

    Vedantam, Nanda Kishore

    2003-01-01

    The objective of this study was to investigate the effects of the mean flow profiles on the instability characteristics in the near-injector region of low-density gas jets injected into high-density ambient gas mediums. To achieve this, a linear temporal stability analysis and a spatio-temporal stability analysis of a low-density round gas jet injected vertically upwards into a high-density ambient gas were performed by assuming three different sets of mean velocity and density profiles. The flow was assumed to be isothermal and locally parallel. Viscous and diffusive effects were ignored. The mean flow parameters were represented as the sum of the mean value and a small normal-mode fluctuation. A second order differential equation governing the pressure disturbance amplitude was derived from the basic conservation equations. The first set of mean velocity and density profiles assumed were those used by Monkewitz and Sohn for investigating absolute instability in hot jets. The second set of velocity and density profiles assumed for this study were the ones used by Lawson. And the third set of mean profiles included a parabolic velocity profile and a hyperbolic tangent density profile. The effects of the inhomogeneous shear layer and the Froude number (signifying the effects of gravity) on the temporal and spatio-temporal results for each set of mean profiles were delineated. Additional information is included in the original extended abstract.

  6. Fitting of the Thomson scattering density and temperature profiles on the COMPASS tokamak

    Science.gov (United States)

    Stefanikova, E.; Peterka, M.; Bohm, P.; Bilkova, P.; Aftanas, M.; Sos, M.; Urban, J.; Hron, M.; Panek, R.

    2016-11-01

    A new technique for fitting the full radial profiles of electron density and temperature obtained by the Thomson scattering diagnostic in H-mode discharges on the COMPASS tokamak is described. The technique combines the conventionally used modified hyperbolic tangent function for the edge transport barrier (pedestal) fitting and a modification of a Gaussian function for fitting the core plasma. Low number of parameters of this combined function and their straightforward interpretability and controllability provide a robust method for obtaining physically reasonable profile fits. Deconvolution with the diagnostic instrument function is applied on the profile fit, taking into account the dependence on the actual magnetic configuration.

  7. Profiles of Phase-Space Density-like Quantities in Elliptical Galaxies

    CERN Document Server

    Chae, Kyu-Hyun

    2013-01-01

    With the profiles of total mass density rho(r), stellar mass density rho_*(r) and stellar (radial) velocity dispersion sigma_*(r) of ~2,000 elliptical galaxies, we investigate combinations of rho_*(r)/[sigma_*(r)]^epsilon and rho(r)/[sigma_*(r)]^epsilon which have the same dimensionality of phase-space density for epsilon=3 and in that case are respectively referred to as pseudo phase-space (PPS) density Q_*(r) and PPS-like density Q'_*(r). Compared with the density profile rho(r) the quantity rho_*(r)/[sigma_*(r)]^epsilon has at least as large scatter but the quantity rho(r)/[sigma_*(r)]^epsilon has ~4 times smaller scatter of slopes for epsilon=3 within the effective radius R_e. If Q'_*(r) is approximated by Q'_*(r) ~ r^{-chi_e} within R_e, we have chi_e=1.860+/-0.035. Remarkably, this slope matches well the PPS density slope chi_Bertschinger=1.875 predicted by the classical self-similar spherical infall model of a self-gravitating collisionless system and the PPS density slope ~1.9 predicted by N-body simu...

  8. Fast electron current density profile and diffusion studies during LHCD in PBX-M

    Energy Technology Data Exchange (ETDEWEB)

    Jones, S.E.; Kesner, J.; Luckhardt, S.; Paoletti, F. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center; von Goeler, S.; Bernabei, S.; Kaita, R. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Rimini, F. [JET Joint Undertaking, Abingdon (United Kingdom)

    1993-08-01

    Successful current profile control experiments using lower hybrid current drive (LCHD) clearly require knowledge of (1) the location of the driven fast electrons and (2) the ability to maintain that location from spreading due to radial diffusion. These issues can be addressed by examining the data from the hard x-ray camera on PBX-M, a unique diagnostic producing two-dimensional, time resolved tangential images of fast electron bremsstrahlung. Using modeling, these line-of-sight images are inverted to extract a radial fast electron current density profile. We note that ``hollow`` profiles have been observed, indicative of off-axis current drive. These profiles can then be used to calculate an upper bound for an effective fast electron diffusion constant: assuming an extremely radially narrow lower hybrid absorption profile and a transport model based on Rax and Moreau, a model fast electron current density profile is calculated and compared to the experimentally derived profile. The model diffusion constant is adjusted until a good match is found. Applied to steady-state quiescent modes on PBX-M, we obtain an upper limit for an effective diffusion constant of about D*=1.1 m{sup 2}/sec.

  9. Validation of COSMIC radio occultation electron density profiles by incoherent scatter radar data

    Science.gov (United States)

    Cherniak, Iurii; Zakharenkova, Irina

    The COSMIC/FORMOSAT-3 is a joint US/Taiwan radio occultation mission consisting of six identical micro-satellites. Each microsatellite has a GPS Occultation Experiment payload to operate the ionospheric RO measurements. FS3/COSMIC data can make a positive impact on global ionosphere study providing essential information about height electron density distribu-tion. For correct using of the RO electron density profiles for geophysical analysis, modeling and other applications it is necessary to make validation of these data with electron density distributions obtained by another measurement techniques such as proven ground based facili-ties -ionosondes and IS radars. In fact as the ionosondes provide no direct information on the profile above the maximum electron density and the topside ionosonde profile is obtained by fitting a model to the peak electron density value, the COSMIC RO measurements can make an important contribution to the investigation of the topside part of the ionosphere. IS radars provide information about the whole electron density profile, so we can estimate the agreement of topside parts between two independent measurements. To validate the reliability of COS-MIC data we have used the ionospheric electron density profiles derived from IS radar located near Kharkiv, Ukraine (geographic coordinates: 49.6N, 36.3E, geomagnetic coordinates: 45.7N, 117.8E). The Kharkiv radar is a sole incoherent scatter facility on the middle latitudes of Eu-ropean region. The radar operates with 100-m zenith parabolic antenna at 158 MHz with peak transmitted power 2.0 MW. The Kharkiv IS radar is able to determine the heights-temporal distribution of ionosphere parameters in height range of 70-1500 km. At the ionosphere in-vestigation by incoherent scatter method there are directly measured the power spectrum (or autocorrelation function) of scattered signal. With using of rather complex procedure of the received signal processing it is possible to estimate the

  10. Role of substituents on the reactivity and electron density profile of diimine ligands: A density functional theory based study

    Indian Academy of Sciences (India)

    Bhakti S Kulkarni; Deepti Mishra; Sourav Pal

    2013-09-01

    In this paper, we study the reactivity of diimines like 2, 2'-bipyridine, 1, l0-phenanthroline and 1, 2, 4-triazines using density-based reactivity descriptors. We discuss the enhancement or diminution in the reactivity of these ligands as a function of two substituent groups, namely methyl (-CH3) group and phenyl (-C6H5) group. The global reactivity descriptors explain the global affinity and philicity of these ligands, whereas the local softness depicts the particular site selectivity. The inter-molecular reactivity trends for the same systems are analysed through the philicity and group philicity indices. The -donor character of these ligands is quantified with the help of electron density profile. In addition, the possible strength of interaction of these ligands with metal ions is supported with actual reaction energies of Ru-L complexes.

  11. Dwarf Galaxy Dark Matter Density Profiles Inferred from Stellar and Gas Kinematics

    CERN Document Server

    Adams, Joshua J; Fabricius, Maximilian H; Bosch, Remco C E van den; Barentine, John C; Bender, Ralf; Gebhardt, Karl; Hill, Gary J; Murphy, Jeremy D; Swaters, R A; Thomas, Jens; van de Ven, Glenn

    2014-01-01

    We present new constraints on the density profiles of dark matter (DM) halos in seven nearby dwarf galaxies from measurements of their integrated stellar light and gas kinematics. The gas kinematics of low mass galaxies frequently suggest that they contain constant density DM cores, while N-body simulations instead predict a cuspy profile. We present a data set of high resolution integral field spectroscopy on seven galaxies and measure the stellar and gas kinematics simultaneously. Using Jeans modeling on our full sample, we examine whether gas kinematics in general produce shallower density profiles than are derived from the stars. Although 2/7 galaxies show some localized differences in their rotation curves between the two tracers, estimates of the central logarithmic slope of the DM density profile, gamma, are generally robust. The mean and standard deviation of the logarithmic slope for the population are gamma=0.67+/-0.10 when measured in the stars and gamma=0.58+/-0.24 when measured in the gas. We als...

  12. Advanced Tokamak current density profiles for non-inductive Tore Supra operation

    Energy Technology Data Exchange (ETDEWEB)

    Kazarian-Vibert, F.; Litaudon, X.; Arslanbekov, R.; Bibet, P.; Froissard, P.; Goniche, M.; Hoang, G.T.; Joffrin, E.; Moreau, D.; Peysson, Y.; Rey, G. [Association Euratom-CEA, Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    1995-12-31

    This document deals with the advanced Tokamak concept concerning self consistent hollow current density profiles. Several Lower Hybrid experiments performed on Tore Supra are presented: the feasibility of the constant-flux operation mode is demonstrated and a new improved confinement regime with a reversed shear has been obtained. (TEC). 12 refs., 5 figs.

  13. Theory for planetary exospheres: II. Radiation pressure effect on exospheric density profiles

    Science.gov (United States)

    Beth, A.; Garnier, P.; Toublanc, D.; Dandouras, I.; Mazelle, C.

    2016-03-01

    The planetary exospheres are poorly known in their outer parts, since the neutral densities are low compared with the instruments detection capabilities. The exospheric models are thus often the main source of information at such high altitudes. We present a new way to take into account analytically the additional effect of the radiation pressure on planetary exospheres. In a series of papers, we present with an Hamiltonian approach the effect of the radiation pressure on dynamical trajectories, density profiles and escaping thermal flux. Our work is a generalization of the study by Bishop and Chamberlain (1989). In this second part of our work, we present here the density profiles of atomic Hydrogen in planetary exospheres subject to the radiation pressure. We first provide the altitude profiles of ballistic particles (the dominant exospheric population in most cases), which exhibit strong asymmetries that explain the known geotail phenomenon at Earth. The radiation pressure strongly enhances the densities compared with the pure gravity case (i.e. the Chamberlain profiles), in particular at noon and midnight. We finally show the existence of an exopause that appears naturally as the external limit for bounded particles, above which all particles are escaping.

  14. Novel analysis technique for measuring edge density fluctuation profiles with reflectometry in the Large Helical Device

    Science.gov (United States)

    Creely, A. J.; Ida, K.; Yoshinuma, M.; Tokuzawa, T.; Tsujimura, T.; Akiyama, T.; Sakamoto, R.; Emoto, M.; Tanaka, K.; Michael, C. A.

    2017-07-01

    A new method for measuring density fluctuation profiles near the edge of plasmas in the Large Helical Device (LHD) has been developed utilizing reflectometry combined with pellet-induced fast density scans. Reflectometer cutoff location was calculated by proportionally scaling the cutoff location calculated with fast far infrared laser interferometer (FIR) density profiles to match the slower time resolution results of the ray-tracing code LHD-GAUSS. Plasma velocity profile peaks generated with this reflectometer mapping were checked against velocity measurements made with charge exchange spectroscopy (CXS) and were found to agree within experimental uncertainty once diagnostic differences were accounted for. Measured density fluctuation profiles were found to peak strongly near the edge of the plasma, as is the case in most tokamaks. These measurements can be used in the future to inform inversion methods of phase contrast imaging (PCI) measurements. This result was confirmed with both a fixed frequency reflectometer and calibrated data from a multi-frequency comb reflectometer, and this method was applied successfully to a series of discharges. The full width at half maximum of the turbulence layer near the edge of the plasma was found to be only 1.5-3 cm on a series of LHD discharges, less than 5% of the normalized minor radius.

  15. Model Predictive Control with Integral Action for Current Density Profile Tracking in NSTX-U

    Science.gov (United States)

    Ilhan, Z. O.; Wehner, W. P.; Schuster, E.; Boyer, M. D.

    2016-10-01

    Active control of the toroidal current density profile may play a critical role in non-inductively sustained long-pulse, high-beta scenarios in a spherical torus (ST) configuration, which is among the missions of the NSTX-U facility. In this work, a previously developed physics-based control-oriented model is embedded in a feedback control scheme based on a model predictive control (MPC) strategy to track a desired current density profile evolution specified indirectly by a desired rotational transform profile. An integrator is embedded into the standard MPC formulation to reject various modeling uncertainties and external disturbances. Neutral beam powers, electron density, and total plasma current are used as actuators. The proposed MPC strategy incorporates various state and actuator constraints directly into the control design process by solving a constrained optimization problem in real-time to determine the optimal actuator requests. The effectiveness of the proposed controller in regulating the current density profile in NSTX-U is demonstrated in closed-loop nonlinear simulations. Supported by the US DOE under DE-AC02-09CH11466.

  16. The effect of baryons on the inner density profiles of rich clusters

    Science.gov (United States)

    Schaller, Matthieu; Frenk, Carlos S.; Bower, Richard G.; Theuns, Tom; Trayford, James; Crain, Robert A.; Furlong, Michelle; Schaye, Joop; Dalla Vecchia, Claudio; McCarthy, I. G.

    2015-09-01

    We use the `Evolution and assembly of galaxies and their environments' (EAGLE) cosmological simulation to investigate the effect of baryons on the density profiles of rich galaxy clusters. We focus on EAGLE clusters with M200 > 1014 M⊙ of which we have six examples. The central brightest cluster galaxies (BCGs) in the simulation have steep stellar density profiles, ρ*(r) ∝ r-3. Stars dominate the mass density for r Frenk-White (NFW) profile, in remarkable agreement with observations. The dark matter halo itself closely follows the NFW form at all resolved radii (r ≳ 3.0 kpc). The EAGLE BCGs have similar surface brightness and line-of-sight velocity dispersion profiles as the BCGs in the sample of Newman et al., which have the most detailed measurements currently available. After subtracting the contribution of the stars to the central density, Newman et al. infer significantly shallower slopes than the NFW value, in contradiction with the EAGLE results. We discuss possible reasons for this discrepancy, and conclude that an inconsistency between the kinematical model adopted by Newman et al. for their BCGs, which assumes isotropic stellar orbits, and the kinematical structure of the EAGLE BCGs, in which the orbital stellar anisotropy varies with radius and tends to be radially biased, could explain at least part of the discrepancy.

  17. Electron density profile measurements from hydrogen line intensity ratio method in Versatile Experiment Spherical Torus

    Science.gov (United States)

    Kim, YooSung; Shi, Yue-Jiang; Yang, Jeong-hun; Kim, SeongCheol; Kim, Young-Gi; Dang, Jeong-Jeung; Yang, Seongmoo; Jo, Jungmin; Oh, Soo-Ghee; Chung, Kyoung-Jae; Hwang, Y. S.

    2016-11-01

    Electron density profiles of versatile experiment spherical torus plasmas are measured by using a hydrogen line intensity ratio method. A fast-frame visible camera with appropriate bandpass filters is used to detect images of Balmer line intensities. The unique optical system makes it possible to take images of Hα and Hβ radiation simultaneously, with only one camera. The frame rate is 1000 fps and the spatial resolution of the system is about 0.5 cm. One-dimensional local emissivity profiles have been obtained from the toroidal line of sight with viewing dumps. An initial result for the electron density profile is presented and is in reasonable agreement with values measured by a triple Langmuir probe.

  18. Monte Carlo Simulations of Density Profiles for Hard-Sphere Chain Fluids Confined Between Surfaces

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Covering a wide range of bulk densities, density profiles for hard-sphere chain fluids (HSCFs) with chain length of 3,4,8,20,32 and 64 confined between two surfaces were obtained by Monte Carlo simulations using extended continuum configurational-bias (ECCB) method. It is shown that the enrichment of beads near surfaces is happened at high densities due to the bulk packing effect, on the contrary, the depletion is revealed at low densities owing to the configurational entropic contribution. Comparisons with those calculated by density functional theory presented by Cai et al. indicate that the agreement between simulations and predictions is good. Compressibility factors of bulk HSCFs calculated using volume fractions at surfaces were also used to test the reliability of various equations of state of HSCFs by different authors.

  19. Mass, velocity anisotropy, and pseudo phase-space density profiles of Abell 2142

    Science.gov (United States)

    Munari, E.; Biviano, A.; Mamon, G. A.

    2014-06-01

    Aims: We aim to compute the mass and velocity anisotropy profiles of Abell 2142 and, from there, the pseudo phase-space density profile Q(r) and the density slope - velocity anisotropy β - γ relation, and then to compare them with theoretical expectations. Methods: The mass profiles were obtained by using three techniques based on member galaxy kinematics, namely the caustic method, the method of dispersion-kurtosis, and MAMPOSSt. Through the inversion of the Jeans equation, it was possible to compute the velocity anisotropy profiles. Results: The mass profiles, as well as the virial values of mass and radius, computed with the different techniques agree with one another and with the estimates coming from X-ray and weak lensing studies. A combined mass profile is obtained by averaging the lensing, X-ray, and kinematics determinations. The cluster mass profile is well fitted by an NFW profile with c = 4.0 ± 0.5. The population of red and blue galaxies appear to have a different velocity anisotropy configuration, since red galaxies are almost isotropic, while blue galaxies are radially anisotropic, with a weak dependence on radius. The Q(r) profile for the red galaxy population agrees with the theoretical results found in cosmological simulations, suggesting that any bias, relative to the dark matter particles, in velocity dispersion of the red component is independent of radius. The β - γ relation for red galaxies matches the theoretical relation only in the inner region. The deviations might be due to the use of galaxies as tracers of the gravitational potential, unlike the non-collisional tracer used in the theoretical relation.

  20. An improved empirical formulation of an ionosphere bottomside electron density profile thickness parameter

    Science.gov (United States)

    Alazo-Cuartas, K.; Radicella, S. M.

    2017-10-01

    An improved empirical formulation for the characterization of the ;base point; of the bottomside ionospheric electron density profile is proposed. The ;base point; in an ionospheric layer is defined by the electron density profile height where the gradient dN/dh reaches a maximum. The difference between the height of the maximum electron density and the height of the ;base point; is proportional to the ionospheric F2 layer thickness parameter B2. The previous empirical formula links the maximum value of dN/dh to foF2 and M(3000)F2 scaled from the ionograms. The new formulation adds a dependence on the solar zenith angle. The use of the new equation improves substantially the calculation of the B2 thickness parameter used in the NeQuick model.

  1. Modified shape of the Eiffel Tower determined for an atmospheric boundary-layer wind profile

    Science.gov (United States)

    Weidman, P. D.

    2009-06-01

    The design and construction of the Eiffel Tower was based, in part, on a uniform horizontal wind model giving 300 kg m-2 kinematic pressure acting on the surface of the tower. Eiffel received a patent for his method of construction that eliminates the need for diagonal trellis bars used to resist the moment of an oncoming wind. At the end of the 19th century boundary-layer theory, laminar or turbulent, was nonexistent. Now, however, models for atmospheric flow over rough landscapes are available, the simplest being a power-law distribution of velocity with height. In this paper we deduce the shape of the tower had Eiffel incorporated this information into the design and construction of his world famous tower. Moreover, we prove Eiffel's observation that the tower profile conforms to the moment distribution wrought by the wind.

  2. A magnetic shape memory micropump: contact-free, and compatible with PCR and human DNA profiling

    Science.gov (United States)

    Ullakko, K.; Wendell, L.; Smith, A.; Müllner, P.; Hampikian, G.

    2012-11-01

    Magnetic shape memory (MSM) Ni-Mn-Ga elements are relatively new materials with a variety of remarkable properties. They respond to changes in magnetic fields by elongating and shortening up to 6%. We have constructed a micropump which consists principally of a single component, the MSM element. The pump can be driven by the rotation of a diametrically magnetized cylindrical magnet or by an electrical rotation of the magnetic field; it is reversible, and can be effectively operated by hand without any electrical power. The MSM element does not inhibit the polymerase chain reaction. We demonstrate that it is compatible with forensic applications and show that it does not inhibit human DNA profiling. This novel pump is suitable for lab-on-a-chip applications that require microfluidics.

  3. A Programmable Beam Shaping System for Tailoring the Profile of High Fluence Laser Beams

    Energy Technology Data Exchange (ETDEWEB)

    Heebner, J; Borden, M; Miller, P; Stolz, C; Suratwala, T; Wegner, P; Hermann, M; Henesian, M; Haynam, C; Hunter, S; Christensen, K; Wong, N; Seppala, L; Brunton, G; Tse, E; Awwal, A; Franks, M; Marley, E; Williams, K; Scanlan, M; Budge, T; Monticelli, M; Walmer, D; Dixit, S; Widmayer, C; Wolfe, J; Bude, J; McCarty, K; DiNicola, J

    2010-11-10

    Customized spatial light modulators have been designed and fabricated for use as precision beam shaping devices in fusion class laser systems. By inserting this device in a low-fluence relay plane upstream of the amplifier chain, 'blocker' obscurations can be programmed into the beam profile to shadow small isolated flaws on downstream optical components that might otherwise limit the system operating energy. In this two stage system, 1920 x 1080 bitmap images are first imprinted on incoherent, 470 nm address beams via pixilated liquid crystal on silicon (LCoS) modulators. To realize defined masking functions with smooth apodized shapes and no pixelization artifacts, address beam images are projected onto custom fabricated optically-addressable light valves. Each valve consists of a large, single pixel liquid cell in series with a photoconductive Bismuth silicon Oxide (BSO) crystal. The BSO crystal enables bright and dark regions of the address image to locally control the voltage supplied to the liquid crystal layer which in turn modulates the amplitude of the coherent beams at 1053 nm. Valves as large as 24 mm x 36 mm have been fabricated with low wavefront distortion (<0.5 waves) and antireflection coatings for high transmission (>90%) and etalon suppression to avoid spectral and temporal ripple. This device in combination with a flaw inspection system and optic registration strategy represents a new approach for extending the operational lifetime of high fluence laser optics.

  4. Density Profiles in Molecular Cloud Cores Associated with High-Mass Star-Forming Regions

    CERN Document Server

    Pirogov, Lev E

    2009-01-01

    Radial density profiles for the sample of dense cores associated with high-mass star-forming regions from southern hemisphere have been derived using the data of observations in continuum at 250 GHz. Radial density profiles for the inner regions of 16 cores (at distances $\\la 0.2-0.8$ pc from the center) are close on average to the $\\rho\\propto r^{-\\alpha}$ dependence, where $\\alpha=1.6\\pm 0.3$. In the outer regions density drops steeper. An analysis with various hydrostatic models showed that the modified Bonnor-Ebert model, which describes turbulent sphere confined by external pressure, is preferable compared with the logotrope and polytrope models practically in all cases. With a help of the Bonnor-Ebert model, estimates of central density in a core, non-thermal velocity dispersion and core size are obtained. The comparison of central densities with the densities derived earlier from the CS modeling reveals differences in several cases. The reasons of such differences are probably connected with the presen...

  5. Inoculation density and nutrient level determine the formation of mushroom-shaped structures in Pseudomonas aeruginosa biofilms

    Science.gov (United States)

    Ghanbari, Azadeh; Dehghany, Jaber; Schwebs, Timo; Müsken, Mathias; Häussler, Susanne; Meyer-Hermann, Michael

    2016-09-01

    Pseudomonas aeruginosa often colonises immunocompromised patients and the lungs of cystic fibrosis patients. It exhibits resistance to many antibiotics by forming biofilms, which makes it hard to eliminate. P. aeruginosa biofilms form mushroom-shaped structures under certain circumstances. Bacterial motility and the environment affect the eventual mushroom morphology. This study provides an agent-based model for the bacterial dynamics and interactions influencing bacterial biofilm shape. Cell motility in the model relies on recently published experimental data. Our simulations show colony formation by immotile cells. Motile cells escape from a single colony by nutrient chemotaxis and hence no mushroom shape develops. A high number density of non-motile colonies leads to migration of motile cells onto the top of the colonies and formation of mushroom-shaped structures. This model proposes that the formation of mushroom-shaped structures can be predicted by parameters at the time of bacteria inoculation. Depending on nutrient levels and the initial number density of stalks, mushroom-shaped structures only form in a restricted regime. This opens the possibility of early manipulation of spatial pattern formation in bacterial colonies, using environmental factors.

  6. X-ray beam-shaping via deformable mirrors: analytical computation of the required mirror profile

    CERN Document Server

    Spiga, Daniele; Svetina, Cristian; Zangrando, Marco; 10.1016/j.nima.2012.10.117

    2013-01-01

    X-ray mirrors with high focusing performances are in use in both mirror mod- ules for X-ray telescopes and in synchrotron and FEL (Free Electron Laser) beamlines. A degradation of the focus sharpness arises in general from geo- metrical deformations and surface roughness, the former usually described by geometrical optics and the latter by physical optics. In general, technological developments are aimed at a very tight focusing, which requires the mirror profile to comply with the nominal shape as much as possible and to keep the roughness at a negligible level. However, a deliberate deformation of the mirror can be made to endow the focus with a desired size and distribution, via piezo actuators as done at the EIS-TIMEX beamline of FERMI@Elettra. The resulting profile can be characterized with a Long Trace Profilometer and correlated with the expected optical quality via a wavefront propagation code. However, if the roughness contribution can be neglected, the com- putation can be performed via a ray-tracin...

  7. Determination of a new uniform thorax density representative of the living population from 3D external body shape modeling.

    Science.gov (United States)

    Amabile, Celia; Choisne, Julie; Nérot, Agathe; Pillet, Hélène; Skalli, Wafa

    2016-05-03

    Body segment parameters (BSP) for each body׳s segment are needed for biomechanical analysis. To provide population-specific BSP, precise estimation of body׳s segments volume and density are needed. Widely used uniform densities, provided by cadavers׳ studies, did not consider the air present in the lungs when determining the thorax density. The purpose of this study was to propose a new uniform thorax density representative of the living population from 3D external body shape modeling. Bi-planar X-ray radiographies were acquired on 58 participants allowing 3D reconstructions of the spine, rib cage and human body shape. Three methods of computing the thorax mass were compared for 48 subjects: (1) the Dempster Uniform Density Method, currently in use for BSPs calculation, using Dempster density data, (2) the Personalized Method using full-description of the thorax based on 3D reconstruction of the rib cage and spine and (3) the Improved Uniform Density Method using a uniform thorax density resulting from the Personalized Method. For 10 participants, comparison was made between the body mass obtained from a force-plate and the body mass computed with each of the three methods. The Dempster Uniform Density Method presented a mean error of 4.8% in the total body mass compared to the force-plate vs 0.2% for the Personalized Method and 0.4% for the Improved Uniform Density Method. The adjusted thorax density found from the 3D reconstruction was 0.74g/cm(3) for men and 0.73g/cm(3) for women instead of the one provided by Dempster (0.92g/cm(3)), leading to a better estimate of the thorax mass and body mass. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Impact of baryon physics on dark matter structures: a detailed simulation study of halo density profiles

    CERN Document Server

    Duffy, Alan R; Kay, Scott T; Vecchia, Claudio Dalla; Battye, Richard A; Booth, C M

    2010-01-01

    The back-reaction of baryons on the dark matter halo density profile is of great interest, not least because it is an important systematic uncertainty when attempting to detect the dark matter. Here, we draw on a large suite of high resolution cosmological hydrodynamical simulations, to systematically investigate this process and its dependence on the baryonic physics associated with galaxy formation. The inclusion of baryons results in significantly more concentrated density profiles if radiative cooling is efficient and feedback is weak. The dark matter halo concentration can in that case increase by as much as 30 (10) per cent on galaxy (cluster) scales. The most significant effects occur in galaxies at high redshift, where there is a strong anti-correlation between the baryon fraction in the halo centre and the inner slope of both the total and the dark matter density profiles. If feedback is weak, isothermal inner profiles form, in agreement with observations of massive, early-type galaxies. However, we ...

  9. Characterization of the internal ion environment of biofilms based on charge density and shape of ion.

    Science.gov (United States)

    Kurniawan, Andi; Tsuchiya, Yuki; Eda, Shima; Morisaki, Hisao

    2015-12-01

    Biofilm polymers contain both electrically positively and negatively charged sites. These charged sites enable the biofilm to trap and retain ions leading to an important role of biofilm such as nutrient recycling and pollutant purification. Much work has focused on the ion-exchange capacity of biofilms, and they are known to adsorb ions through an exchange mechanism between the ions in solution and the ions adsorbed to the charged sites on the biofilm polymer. However, recent studies suggest that the adsorption/desorption behavior of ions in a biofilm cannot be explained solely by this ion exchange mechanism. To examine the possibility that a substantial amount of ions are held in the interstitial region of the biofilm polymer by an electrostatic interaction, intact biofilms formed in a natural environment were immersed in distilled water and ion desorption was investigated. All of the detected ion species were released from the biofilms over a short period of time, and very few ions were subsequently released over more time, indicating that the interstitial region of biofilm polymers is another ion reserve. The extent of ion retention in the interstitial region of biofilms for each ion can be determined largely by charge density, |Z|/r, where |Z| is the ion valence as absolute value and r is the ion radius. The higher |Z|/r value an ion has, the stronger it is retained in the interstitial region of biofilms. Ion shape is also a key determinant of ion retention. Spherical and non-spherical ions have different correlations between the condensation ratio and |Z|/r. The generality of these findings were assured by various biofilm samples. Thus, the internal regions of biofilms exchange ions dynamically with the outside environment.

  10. Effect of small scale density perturbations on the formation of dark matter halo profiles

    CERN Document Server

    Pilipenko, S V; Lukash, V N; Mikheeva, E V

    2012-01-01

    With help of a set of toy N-body models of dark halo formation we study the impact of small scale initial perturbations on the inner density profiles of haloes. We find a significant flattening of the inner slope $\\alpha={d \\log \\rho \\over d \\log r}$ to $\\alpha=-0.5$ in some range of scales and amplitudes of the perturbations (while in the case of absence of these perturbations the NFW profile with $\\alpha=-1$ is reproduced). This effect may be responsible for the formation of cuspless galactic haloes.

  11. Effect of small-scale density perturbations on the formation of dark matter halo profiles

    Science.gov (United States)

    Pilipenko, S. V.; Doroshkevich, A. G.; Lukash, V. N.; Mikheeva, E. V.

    2012-11-01

    With the help of a set of toy N-body models of dark halo formation, we study the impact of small-scale initial perturbations on the inner density profiles of haloes. We find a significant flattening of the inner slope ? to α=-0.5 in some range of scales and amplitudes of the perturbations (while in the case of absence of these perturbations, the Navarro-Frenk-White profile with α=-1 is reproduced). This effect may be responsible for the formation of cuspless galactic haloes.

  12. Effect of small scale density perturbations on the formation of dark matter halo profiles

    OpenAIRE

    Pilipenko, S. V.; Doroshkevich, A. G.; Lukash, V. N.; Mikheeva, E. V.

    2012-01-01

    With help of a set of toy N-body models of dark halo formation we study the impact of small scale initial perturbations on the inner density profiles of haloes. We find a significant flattening of the inner slope $\\alpha={d \\log \\rho \\over d \\log r}$ to $\\alpha=-0.5$ in some range of scales and amplitudes of the perturbations (while in the case of absence of these perturbations the NFW profile with $\\alpha=-1$ is reproduced). This effect may be responsible for the formation of cuspless galact...

  13. TIDAL STIRRING OF DISKY DWARFS WITH SHALLOW DARK MATTER DENSITY PROFILES: ENHANCED TRANSFORMATION INTO DWARF SPHEROIDALS

    Energy Technology Data Exchange (ETDEWEB)

    Kazantzidis, Stelios [Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States); Lokas, Ewa L. [Nicolaus Copernicus Astronomical Center, 00-716 Warsaw (Poland); Mayer, Lucio, E-mail: stelios@mps.ohio-state.edu [Institute for Theoretical Physics, University of Zuerich, CH-8057 Zuerich (Switzerland)

    2013-02-20

    According to the tidal stirring model, late type, rotationally supported dwarfs resembling present day dwarf irregular (dIrr) galaxies can transform into dwarf spheroidals (dSphs) via interactions with Milky-Way-sized hosts. We perform collisionless N-body simulations to investigate for the first time how tidal stirring depends on the dark matter (DM) density distribution in the central stellar region of the progenitor disky dwarf. Specifically, we explore various asymptotic inner slopes {gamma} of the dwarf DM density profiles ({rho}{proportional_to}r {sup -{gamma}}). For a given orbit inside the primary galaxy, rotationally supported dwarfs embedded in DM halos with core-like distributions ({gamma} = 0.2) and mild density cusps ({gamma} = 0.6) demonstrate a substantially enhanced likelihood and efficiency of transformation into dSphs compared to their counterparts with steeper DM density profiles ({gamma} = 1). Such shallow DM distributions are akin to those of observed dIrrs highlighting tidal stirring as a plausible model for the Local Group (LG) morphology-density relation. When {gamma} < 1, a single pericentric passage can induce dSph formation and disky dwarfs on low-eccentricity or large-pericenter orbits are able to transform; these new results allow tidal stirring to explain virtually all known dSphs across a wide range of distances from their hosts. A subset of disky dwarfs initially embedded in DM halos with shallow density profiles are eventually disrupted by the primary; those that survive as dSphs are generally on orbits with lower eccentricities and/or larger pericenters compared to those of typical cold dark matter satellites. The latter could explain the peculiar orbits of several LG dSphs such as Fornax, Leo I, Tucana, and Cetus.

  14. The characteristic shape of emission profiles of plasma spokes in HiPIMS: the role of secondary electrons

    CERN Document Server

    Hecimovic, A; Brinkmann, R -P; Böke, M; Winter, J

    2013-01-01

    A time resolved analysis of the emission of HiPIMS plasmas reveals inhomogeneities in the form of rotating spokes. The shape of these spokes is very characteristic depending on the target material. The localized enhanced light emission has been correlated with the ion production. Based on these data, the peculiar shape of the emission profiles can be explained by the localized generation of secondary electrons, resulting in an energetic electron pressure exceeding the magnetic pressure. This general picture is able to explain the observed emission profile for different target materials including gas rarefaction and second ionization potential of the sputtered elements.

  15. Analytic, piecewise solution to the Lane-Emden equation for stars with complex density profiles

    Science.gov (United States)

    Miller, Jeff; Bogdanovic, Tamara

    2017-01-01

    The polytropic models of stars are used for a variety of applications in computational astrophysics. These are typically obtained by numerically solving the Lane-Emden equation for a star in hydrostatic equilibrium under assumption that the pressure and density within the star obey the polytropic equation of state. We present an efficient analytic, piecewise differentiable solution to the Lane-Emden equation which allows “stitching” of different polytropes to represent complex pressure and density profiles. This approach can be used to model stars with distinct properties in their cores and envelopes, such as the evolved red giant and horizontal branch stars.

  16. Density profiles of Ar adsorbed in slits of CO2: Spontaneous symmetry breaking revisited

    Science.gov (United States)

    Szybisz, Leszek; Sartarelli, Salvador A.

    2008-03-01

    A recently reported symmetry breaking of density profiles of fluid argon confined by two parallel solid walls of carbon dioxide is studied. The calculations are performed in the framework of a nonlocal density functional theory. It is shown that the existence of such asymmetrical solutions is restricted to a special choice for the adsorption potential, where the attraction of the solid-fluid interaction is reduced by the introduction of a hard-wall repulsion. The behavior as a function of the slit's width is also discussed. All the results are placed in the context of the current knowledge on this matter.

  17. Modeling of 2-dimensional and 3-dimensional etch profiles in high density plasma reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hoekstra, R.J.; Kushner, M.J. [Univ. of Illinois, Urbana, IL (United States). Dept. of Electrical and Computer Engineering; Sukharev, V. [LSI Logic Corp., Santa Clara, CA (United States)

    1997-12-31

    In order to model the plasma etching process from plasma generation to etch profile evolution, processes from the macroscopic reactor scale to the microscopic feature scale must be simulated. An integrated monte Carlo feature Profile Model (MCFPM) has been developed to examine the time evolution of etch profiles in high density plasma systems. By integrating the MCFPM with the Hybrid Plasma Equipment Model (HPEM), the authors are able to self-consistently determine the etch profiles for specific regions on the wafer in specific reactor geometry with specified parameters for power, chemistry, gas flow, etc. The latest improvements of the model include the effects of incoming particle angle and energy on reaction and reflection based on the results of molecular dynamics simulations. Increase the specular reflection of high energy particles leads to more vertical sidewalls and corner clearing but can also cause deformation of the bottom of the profile surface. For Chlorine etching of 2D and 3D profiles in polysilicon, the model results will be compared to experimental results in an inductively couple etching reactor. The changes due to radial location as well as sub wafer and superwafer topography be examined.

  18. Modulation of solar flare particles and track density profiles in gas-rich meteorite grains

    Science.gov (United States)

    Lee, M. A.

    1976-01-01

    A solution is presented to the problem concerning the time-averaged solar flare particle flux as a function of kinetic energy and distance from the sun for a given particle injection spectrum at the sun within the framework of standard diffusion-convection-adiabatic deceleration theory with the diffusion coefficient independent of distance from the sun. Results of the calculations which give best agreement with observations at 1 AU are presented and discussed, with particular reference to their implications for gas-rich meteorites. Normalization at the orbit of earth is achieved via observed track density versus depth profiles in lunar vug crystals. It is shown that if gas-rich meteorite grains were irradiated in the asteroid belt and if source and modulation parameters have changed little since irradiation, the track density should be 'harder' than the lunar vug profile by about 0.2-0.3 in the index. Quantitative estimation of solar flare particle exposure ages is discussed.

  19. Double-Humped Transverse Density Profile in Two-Dimensional Chute Flow with Rough Sidewalls

    Institute of Scientific and Technical Information of China (English)

    HU Guo-Qi; ZHANG Xun-Sheng; BAO De-Song; TANG Xiao-Wei

    2006-01-01

    @@ We study a two-dimensional granular rapid flow with rough sidewalls stuck with the same size discs by molecular dynamics simulation. A transient state of the double-humped density profile in the flowing process has been found, which appears and moves as travelling wave and is the same as the phenomena in the recent experiments [Acta Phys. Sin. 53 (2004) 3389 (in Chinese)].

  20. Density Profiles of CDM Microhalos and their Implications for Annihilation Boost Factors

    CERN Document Server

    Anderhalden, Donnino

    2013-01-01

    In a standard cold dark matter (CDM) cosmology, microhalos at the CDM cutoff scale are the first and smallest objects expected to form in the universe. Here we present results of high resolution simulations of three representative roughly Earth-mass microhalos in order to determine their inner density profile. We find that CDM microhalos in simulations without a cutoff in the power spectrum roughly follow the NFW density profile, just like the much larger CDM halos on galaxy and galaxy cluster scales. But having a cutoff in the initial power spectrum at a typical neutralino free streaming scale of $10^{-7} M_{\\odot}$ makes their inner density profiles considerably steeper, i.e. $\\rho \\propto r^{-(1.3-1.4)}$, in good agreement with the results from Ishiyama et al. (2010). An extrapolation of the halo and subhalo mass functions down to the cutoff scale indicates that microhalos are extremely abundant throughout the present day dark matter distribution and might contribute significantly to indirect dark matter d...

  1. A mass-dependent density profile for dark matter haloes including the influence of galaxy formation

    CERN Document Server

    Di Cintio, Arianna; Dutton, Aaron A; Macciò, Andrea V; Stinson, Greg S; Knebe, Alexander

    2014-01-01

    We introduce a mass dependent density profile to describe the distribution of dark matter within galaxies, which takes into account the stellar-to-halo mass dependence of the response of dark matter to baryonic processes. The study is based on the analysis of hydrodynamically simulated galaxies from dwarf to Milky Way mass, drawn from the MaGICC project, which have been shown to match a wide range of disk scaling relationships. We find that the best fit parameters of a generic double power-law density profile vary in a systematic manner that depends on the stellar-to-halo mass ratio of each galaxy. Thus, the quantity Mstar/Mhalo constrains the inner ($\\gamma$) and outer ($\\beta$) slopes of dark matter density, and the sharpness of transition between the slopes($\\alpha$), reducing the number of free parameters of the model to two. Due to the tight relation between stellar mass and halo mass, either of these quantities is sufficient to describe the dark matter halo profile including the effects of baryons. The ...

  2. Role of Density Profiles for the Nonlinear Propagation of Intense Laser Beam through Plasma Channel

    Directory of Open Access Journals (Sweden)

    Sonu Sen

    2014-01-01

    Full Text Available In this work role of density profiles for the nonlinear propagation of intense laser beam through plasma channel is analyzed. By employing the expression for the dielectric function of different density profile plasma, a differential equation for beamwidth parameter is derived under WKB and paraxial approximation. The laser induces modifications of the dielectric function through nonlinearities. It is found that density profiles play vital role in laser-plasma interaction studies. To have numerical appreciation of the results the propagation equation for plasma is solved using the fourth order Runge-Kutta method for the initial plane wave front of the beam, using boundary conditions. The spot size of the laser beam decreases as the beam penetrates into the plasma and significantly adds self-focusing in plasma. This causes the laser beam to become more focused by reduction of diffraction effect, which is an important phenomenon in inertial confinement fusion and also for the understanding of self-focusing of laser pulses. Numerical computations are presented and discussed in the form of graphs for typical parameters of laser-plasma interaction.

  3. The masses and density profiles of halos in a LCDM galaxy formation simulation

    CERN Document Server

    Schaller, Matthieu; Bower, Richard G; Theuns, Tom; Jenkins, Adrian; Schaye, Joop; Crain, Robert A; Furlong, Michelle; Vecchia, Claudio Dalla; McCarthy, I G

    2014-01-01

    We investigate the internal structure and density profiles of halos of mass $10^{10}-10^{14}~M_\\odot$ in the Evolution and Assembly of Galaxies and their Environment (EAGLE) simulations. These follow the formation of galaxies in a $\\Lambda$CDM Universe and include a treatment of the baryon physics thought to be relevant. The EAGLE simulations reproduce the observed present-day galaxy stellar mass function, as well as many other properties of the galaxy population as a function of time. We find significant differences between the masses of halos in the EAGLE simulations and in simulations that follow only the dark matter component. Nevertheless, halos are well described by the Navarro-Frenk-White (NFW) density profile at radii larger than ~5% of the virial radius but, closer to the centre, the presence of stars can produce cuspier profiles. Central enhancements in the total mass profile are most important in halos of mass $10^{12}-10^{13}M_\\odot$, where the stellar fraction peaks. Over the radial range where t...

  4. Investigation of the Spring-In of a Pultruded L-Shaped Profile for Various Processing Conditions and Thicknesses

    NARCIS (Netherlands)

    Baran, Ismet; Hattel, Jesper H.; Akkerman, Remko

    2014-01-01

    In this study, a thermo-mechanical finite element model is developed to predict the spring-in of an industrially pultruded L-shaped profile made of glass/polyester composite. The resin curing kinetics are obtained from the differential scanning calorimetry (DSC) experiments. The development of the r

  5. Parabola-like shaped pH-rate profile for phenols oxidation by aqueous permanganate.

    Science.gov (United States)

    Du, Juanshan; Sun, Bo; Zhang, Jing; Guan, Xiaohong

    2012-08-21

    Oxidation of phenols by permanganate in the pH range of 5.0-9.0 generally exhibits a parabola-like shape with the maximum reaction rate obtained at pH close to phenols' pK(a). However, a monotonic increase or decrease is observed if phenols' pK(a) is beyond the pH range of 5.0-9.0. A proton transfer mechanism is proposed in which the undissociated phenol is directly oxidized by permanganate to generate products while a phenolate-permanganate adduct, intermediate, is formed between dissociated phenol and permanganate ion and this is the rate-limiting step for phenolates oxidation by permanganate. The intermediate combines with H(+) and then decomposes to products. Rate equations derived based on the steady-state approximation can well simulate the experimentally derived pH-rate profiles. Linear free energy relationships (LFERs) were established among the parameters obtained from the modeling, Hammett constants, and oxygen natural charges in phenols and phenolates. LFERs reveal that chlorine substituents have opposite influence on the susceptibility of phenols and phenolates to permanganate oxidation and phenolates are not necessarily more easily oxidized than their neutral counterparts. The chlorine substituents regulate the reaction rate of chlorophenolates with permanganate mainly by influencing the natural charges of the oxygen atoms of dissociated phenols while they influence the oxidation of undissociated chlorophenols by permanganate primarily by forming intramolecular hydrogen bonding with the phenolic group.

  6. Enhancing the T-shaped learning profile when teaching hydrology using data, modeling, and visualization activities

    Science.gov (United States)

    Sanchez, Christopher A.; Ruddell, Benjamin L.; Schiesser, Roy; Merwade, Venkatesh

    2016-03-01

    Previous research has suggested that the use of more authentic learning activities can produce more robust and durable knowledge gains. This is consistent with calls within civil engineering education, specifically hydrology, that suggest that curricula should more often include professional perspective and data analysis skills to better develop the "T-shaped" knowledge profile of a professional hydrologist (i.e., professional breadth combined with technical depth). It was expected that the inclusion of a data-driven simulation lab exercise that was contextualized within a real-world situation and more consistent with the job duties of a professional in the field, would provide enhanced learning and appreciation of job duties beyond more conventional paper-and-pencil exercises in a lower-division undergraduate course. Results indicate that while students learned in both conditions, learning was enhanced for the data-driven simulation group in nearly every content area. This pattern of results suggests that the use of data-driven modeling and visualization activities can have a significant positive impact on instruction. This increase in learning likely facilitates the development of student perspective and conceptual mastery, enabling students to make better choices about their studies, while also better preparing them for work as a professional in the field.

  7. Computational modeling of bone density profiles in response to gait: a subject-specific approach.

    Science.gov (United States)

    Pang, Henry; Shiwalkar, Abhishek P; Madormo, Chris M; Taylor, Rebecca E; Andriacchi, Thomas P; Kuhl, Ellen

    2012-03-01

    The goal of this study is to explore the potential of computational growth models to predict bone density profiles in the proximal tibia in response to gait-induced loading. From a modeling point of view, we design a finite element-based computational algorithm using the theory of open system thermodynamics. In this algorithm, the biological problem, the balance of mass, is solved locally on the integration point level, while the mechanical problem, the balance of linear momentum, is solved globally on the node point level. Specifically, the local bone mineral density is treated as an internal variable, which is allowed to change in response to mechanical loading. From an experimental point of view, we perform a subject-specific gait analysis to identify the relevant forces during walking using an inverse dynamics approach. These forces are directly applied as loads in the finite element simulation. To validate the model, we take a Dual-Energy X-ray Absorptiometry scan of the subject's right knee from which we create a geometric model of the proximal tibia. For qualitative validation, we compare the computationally predicted density profiles to the bone mineral density extracted from this scan. For quantitative validation, we adopt the region of interest method and determine the density values at fourteen discrete locations using standard and custom-designed image analysis tools. Qualitatively, our two- and three-dimensional density predictions are in excellent agreement with the experimental measurements. Quantitatively, errors are less than 3% for the two-dimensional analysis and less than 10% for the three-dimensional analysis. The proposed approach has the potential to ultimately improve the long-term success of possible treatment options for chronic diseases such as osteoarthritis on a patient-specific basis by accurately addressing the complex interactions between ambulatory loads and tissue changes.

  8. Radial Surface Density Profiles of Gas and Dust in the Debris Disk Around 49 Ceti

    Science.gov (United States)

    Hughes, A. Meredith; Lieman-Sifry, Jesse; Flaherty, Kevin M.; Daley, Cail M.; Roberge, Aki; Kospal, Agnes; Moor, Attila; Kamp, Inga; Wilner, David J.; Andrews, Sean M.; hide

    2017-01-01

    We present approximately 0".4 resolution images of CO(3-2) and associated continuum emission from the gas-bearing debris disk around the nearby A star 49 Ceti, observed with the Atacama Large Millimeter/Submillimeter Array (ALMA). We analyze the ALMA visibilities in tandem with the broadband spectral energy distribution to measure the radial surface density profiles of dust and gas emission from the system. The dust surface density decreases with radius between approximately 100 and 310 au, with a marginally significant enhancement of surface density at a radius of approximately 110 au. The SED requires an inner disk of small grains in addition to the outer disk of larger grains resolved by ALMA. The gas disk exhibits a surface density profile that increases with radius, contrary to most previous spatially resolved observations of circumstellar gas disks. While approximately 80% of the CO flux is well described by an axisymmetric power-law disk in Keplerian rotation about the central star, residuals at approximately 20% of the peak flux exhibit a departure from axisymmetry suggestive of spiral arms or a warp in the gas disk. The radial extent of the gas disk (approx. 220 au) is smaller than that of the dust disk (approx. 300 au), consistent with recent observations of other gasbearing debris disks. While there are so far only three broad debris disks with well characterized radial dust profiles at millimeter wavelengths, 49 Ceti's disk shows a markedly different structure from two radially resolved gas-poor debris disks, implying that the physical processes generating and sculpting the gas and dust are fundamentally different.

  9. A New Profile Shape Matching Stereovision Algorithm for Real-time Human Pose and Hand Gesture Recognition

    Directory of Open Access Journals (Sweden)

    Dong Zhang

    2014-02-01

    Full Text Available This paper presents a new profile shape matching stereovision algorithm that is designed to extract 3D information in real time. This algorithm obtains 3D information by matching profile intensity shapes of each corresponding row of the stereo image pair. It detects the corresponding matching patterns of the intensity profile rather than the intensity values of individual pixels or pixels in a small neighbourhood. This approach reduces the effect of the intensity and colour variations caused by lighting differences. As with all real-time vision algorithms, there is always a trade-off between accuracy and processing speed. This algorithm achieves a balance between the two to produce accurate results for real-time applications. To demonstrate its performance, the proposed algorithm is tested for human pose and hand gesture recognition to control a smart phone and an entertainment system.

  10. Body mass index, general fatness, lipid profile and bone mineral density in young women and men

    Directory of Open Access Journals (Sweden)

    Kopiczko Anna

    2017-03-01

    Full Text Available The bone tissue is metabolically active. Throughout the entire life, it undergoes changes in the form of bone resorption processes which are successive, with the participation of the resorbing cells and bone formation processes. The aim of the study was to evaluate mineral density and bone mass tissue and the lipid profile, BMI, total body fat in young females and males. The study involved 100 people (50 females and 50 males studying in Warsaw at the age of 23,2 ± 4,0 years. The densitometry method of the forearm was used for the assessment of bone mineral density (BMD and bone mass (BMC. The method of bioelectrical impedance was used for the assessment of body components. Basic body dimensions and indicators were assessed using anthropometric measurements. Body height, body mass and the needs for the densitometry study of the forearm were measured. The total cholesterol concentration was determined in the blood serum using diagnostic kits, as well as high-density lipoprotein (HDL-C and triglycerides. The concentration of the low-density lipoprotein (LDL-C was calculated. While in men the occurrence of a significant, positive correlation was stated between the concentration of the HDL cholesterol fraction and the mineral density and T-score index in the ultra-distal point, the analysis of the compounds of mineral density (BMD, bone mass (BMC of the forearm, T-score index with somatic features in women showed a significant, positive relation between the body weight and the bone mass mineral density and T-score indicator in the proximal point. Also, a significant weak, positive correlation was observed between the BMI, the mineral density and T-score indicator in the proximal point. In men, the occurrence of significant, positive correlations was stated between the body weight and BMC, BMD, T-score indicator in the proximal point of the forearm bone and ultra-distal point. Similar relations were observed between the BMI, mineral density, T

  11. Shaping of the axial power density distribution in the core to minimize the vapor volume fraction at the outlet of the VVER-1200 fuel assemblies

    Science.gov (United States)

    Savander, V. I.; Shumskiy, B. E.; Pinegin, A. A.

    2016-12-01

    The possibility of decreasing the vapor fraction at the VVER-1200 fuel assembly outlet by shaping the axial power density field is considered. The power density field was shaped by axial redistribution of the concentration of the burnable gadolinium poison in the Gd-containing fuel rods. The mathematical modeling of the VVER-1200 core was performed using the NOSTRA computer code.

  12. Comparison of current density profiles based on particle orbit-driven current in steady-state plasma on QUEST

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Md Mahbub, E-mail: m.alam@triam.kyushu-u.ac.jp [IGSES, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Nakamura, Kazuo [RIAM, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Xia, Fan [CFS, SWIP, P.O. Box 432, 610041 Chengdu (China); Mitarai, Osamu [Tokai University, Kumamoto 862-8652 (Japan); Hasegawa, Makoto; Tokunaga, Kazutoshi; Araki, Kuniaki; Zushi, Hideki; Hanada, Kazuaki; Fujisawa, Akihide; Idei, Hiroshi; Nagashima, Yoshihiko; Kawasaki, Shoji; Nakashima, Hisatoshi; Higashijima, Aki; Nagata, Takahiro [RIAM, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan)

    2016-11-01

    Highlights: • Electron cyclotron resonance heating (ECRH) of QUEST. • Particle guiding center orbit calculation. • Orbit-driven current density profile. • Hollow current density. • Equilibrium condition for steady-state operation of QUEST. - Abstract: In the present RF-driven divertor plasma of QUEST, it has been observed that orbit-driven current flows in the open magnetic surfaces outside of the closed magnetic surfaces. To observe this phenomenon and the characteristics of the orbit-driven current, current density profiles have been calculated on two different equilibrium conditions. We calculated current density profiles from particle guiding center orbits both for the fundamental and the second harmonic resonances for the 8.2 GHz electron cyclotron current drive. From this calculation, hollow current density profiles have been obtained with significant characteristics on both conditions. Only positive current distribution has been observed in the open magnetic surfaces outside of the closed magnetic surfaces.

  13. A procedure to analyze nonlinear density waves in Saturn's rings using several occultation profiles

    CERN Document Server

    Rappaport, N J; French, R G; Marouf, E A; McGhee, C A

    2010-01-01

    Cassini radio science experiments have provided multiple occultation optical depth profiles of Saturn's rings that can be used in combination to analyze density waves. This paper establishes an accurate procedure of inversion of the wave profiles to reconstruct the wave kinematic parameters as a function of semi-major axis, in the nonlinear regime. This procedure is achieved from simulated data in the presence of realistic noise perturbations, to control the reconstruction error. By way of illustration we have applied our procedure to the Mimas 5:3 density wave. We were able to recover precisely the kinematic parameters from the radio experiment occultation data in most of the propagation region; a preliminary analysis of the pressure-corrected dispersion allowed us to determine new but still uncertain values for the opacity ($K\\simeq 0.02$ cm$^2$/g) and velocity dispersion of ($c_o\\simeq 0.6$ cm/s) in the wave region. Our procedure constitutes the first step in our planned analysis of the density waves of Sa...

  14. Fluid and gyrokinetic modelling of particle transport in plasmas with hollow density profiles

    Science.gov (United States)

    Tegnered, D.; Oberparleiter, M.; Nordman, H.; Strand, P.

    2016-11-01

    Hollow density profiles occur in connection with pellet fuelling and L to H transitions. A positive density gradient could potentially stabilize the turbulence or change the relation between convective and diffusive fluxes, thereby reducing the turbulent transport of particles towards the center, making the fuelling scheme inefficient. In the present work, the particle transport driven by ITG/TE mode turbulence in regions of hollow density profiles is studied by fluid as well as gyrokinetic simulations. The fluid model used, an extended version of the Weiland transport model, Extended Drift Wave Model (EDWM), incorporates an arbitrary number of ion species in a multi-fluid description, and an extended wavelength spectrum. The fluid model, which is fast and hence suitable for use in predictive simulations, is compared to gyrokinetic simulations using the code GENE. Typical tokamak parameters are used based on the Cyclone Base Case. Parameter scans in key plasma parameters like plasma β, R/LT , and magnetic shear are investigated. It is found that β in particular has a stabilizing effect in the negative R/Ln region, both nonlinear GENE and EDWM show a decrease in inward flux for negative R/Ln and a change of direction from inward to outward for positive R/Ln . This might have serious consequences for pellet fuelling of high β plasmas.

  15. Association of lipid profile with bone mineral density in postmenopausal women in Yazd province

    Science.gov (United States)

    Ghadiri-Anari, Akram; Mortezaii-Shoroki, Zahra; Modarresi, Mozhgan; Dehghan, Ali

    2016-01-01

    Background: Low bone mass is a major health problem in postmenopausal women. There is no general agreement regarding relationship between serum level of lipids and bone mineral density. Objective: This study was carried out to investigate the association between lipid profile and bone mineral density (BMD) in postmenopausal women in Yazd, Iran. Materials and Methods: This cross-sectional study was performed on 170 women aged between 50 and 70 years old with menopause for at least one year from Yazd, Iran, between March 2013 to September 2013. Association of lipid profile and BMD were measured in all study participants. Results: Among our participants 73 cases had lumbar osteoporosis, 17 cases had femoral osteoporosis and 80 cases did n’t have osteoporosis. After controlling for body mass index, there were no correlations between serum level of lipids and bone mineral density of femur and lumbar bones. Conclusion: No significant association between serum level of lipids and BMD of femur and lumbar was found in postmenopausal women. PMID:27738662

  16. Density profile in thin films of polybutadiene on silicon oxide substrates: a TOF-NR study.

    Science.gov (United States)

    Hoppe, E Tilo; Sepe, Alessandro; Haese-Seiller, Martin; Moulin, Jean-François; Papadakis, Christine M

    2013-08-27

    We have investigated thin films from fully deuterated polybutadiene (PB-d6) on silicon substrates with the aim of detecting and characterizing a possible interphase in the polymer film near the substrate using time-of-flight neutron reflectometry (TOF-NR). As substrates, thermally oxidized silicon wafers were either used as such or they were coated with triethylethoxysilyl modified 1,2-PB prior to deposition of the PB-d6 film. TOF-NR reveals that, for both substrates, the scattering length density (SLD) of the PB films decreases near the solid interface. The reduction of SLD is converted to an excess fraction of free volume. To further verify the existence of the interphase in PB-d6, we attempt to model the TOF-NR curves with density profiles which do not feature an interphase. These density profiles do not describe the TOF-NR curves adequately. We conclude that, near the solid interface, an interphase having an SLD lower than the bulk of the film is present.

  17. High-Latitude Topside Ionospheric Vertical Electron Density Profile Changes in Response to Large Magnetic Storms

    Science.gov (United States)

    Benson, Robert F.; Fainberg, Joseph; Osherovich, Vladimir A.; Truhlik, Vladimir; Wang, Yongli; Bilitza, Dieter; Fung, Shing F.

    2016-01-01

    Large magnetic-storm-induced changes were detected in high-latitude topside vertical electron density profiles Ne(h) in a database of profiles and digital topside ionograms, from the International Satellites for Ionospheric Studies (ISIS) program, that enabled Ne(h) profiles to be obtained in nearly the same region of space before, during, and after a major magnetic storm (Dst -100nT). Storms where Ne(h) profiles were available in the high-latitude Northern Hemisphere had better coverage of solar wind parameters than storms with available Ne(h) profiles in the high-latitude Southern Hemisphere. Large Ne(h) changes were observed during all storms, with enhancements and depletions sometimes near a factor of 10 and 0.1, respectively, but with substantial differences in the responses in the two hemispheres. Large spatial andor temporal Ne(h) changes were often observed during Dst minimum and during the storm recovery phase. The storm-induced Ne(h) changes were the most pronounced and consistent in the Northern Hemisphere in that large enhancements were observed during winter nighttime and large depletions during winter and spring daytime. The limited available cases suggested that these Northern Hemisphere enhancements increased with increases of the time-shifted solar wind velocity v, magnetic field B, and with more negative values of the B components except for the highest common altitude (1100km) of the profiles. There was also some evidence suggesting that the Northern Hemisphere depletions were related to changes in the solar wind parameters. Southern Hemisphere storm-induced enhancements and depletions were typically considerably less with depletions observed during summer nighttime conditions and enhancements during summer daytime and fall nighttime conditions.

  18. Relativistic self-focusing of intense laser beam in thermal collisionless quantum plasma with ramped density profile

    Science.gov (United States)

    Zare, S.; Yazdani, E.; Rezaee, S.; Anvari, A.; Sadighi-Bonabi, R.

    2015-04-01

    Propagation of a Gaussian x-ray laser beam has been analyzed in collisionless thermal quantum plasma with considering a ramped density profile. In this density profile due to the increase in the plasma density, an earlier and stronger self-focusing effect is noticed where the beam width oscillates with higher frequency and less amplitude. Moreover, the effect of the density profile slope and the initial plasma density on the laser propagation has been studied. It is found that, by increasing the initial density and the ramp slope, the laser beam focuses faster with less oscillation amplitude, smaller laser spot size and more oscillations. Furthermore, a comparison is made among the laser self-focusing in thermal quantum plasma, cold quantum plasma and classical plasma. It is realized that the laser self-focusing in the quantum plasma becomes stronger in comparison with the classical regime.

  19. The Shape and Profile of the Milky Way Halo as Seen by the CFHT Legacy Survey

    CERN Document Server

    Sesar, Branimir; Ivezic, Zeljko

    2010-01-01

    We use Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) data for 170 deg^2, recalibrated and transformed to the Sloan Digital Sky Survey ugri photometric system, to study the distribution of near-turnoff main sequence stars in the Galactic halo along four lines of sight, to heliocentric distances of ~35 kpc. We find that the halo stellar number density profile becomes steeper at Galactocentric distances greater than R_{gal}~28 kpc, with the power law index changing from n_{inner}=-2.62+-0.04 to n_{outer}=-3.8+-0.1. In particular, we test a series of single power law models and find them to be strongly disfavored by the data. We measure the oblateness of the halo to be q=c/a=0.70+-0.01 and detect no evidence of it changing across the range of probed distances. The Sagittarius stream is detected in the l=173 and b=-62 direction as an overdensity of [Fe/H] ~ -1.5 dex stars at R_{gal}~32 kpc, providing a new constraint for the Sagittarius stream and dark matter halo models. We also detect the Monoceros strea...

  20. Probability density function shape sensitivity in the statistical modeling of turbulent particle dispersion

    Science.gov (United States)

    Litchford, Ron J.; Jeng, San-Mou

    1992-01-01

    The performance of a recently introduced statistical transport model for turbulent particle dispersion is studied here for rigid particles injected into a round turbulent jet. Both uniform and isosceles triangle pdfs are used. The statistical sensitivity to parcel pdf shape is demonstrated.

  1. A simple frequency sweep linearization method for FM density profile reflectometry

    Science.gov (United States)

    Liu, Adi; Hu, Jianqiang; Doyle, Edward; Zhang, Jin; Li, Hong; Zhou, Chu; Zhang, Xiaohui; Wang, Mingyuan; Lan, Tao; Xie, Jinglin; Liu, Wandong; Yu, Changxuan

    2015-11-01

    Frequency modulated, continuous wave (FMCW) reflectometry is widely used to measure the electron density profile on fusion devices. To ensure the output intermediate frequency signal is proportional to the propagation delay time, the frequency sweep should be linearized, especially for reflectometry with sweeping periods of only a few microseconds. We introduce a simple dynamic calibration technique to linearize the frequency sweep based on digital complex demodulation methods, without using a Fourier transform, which would induce a trade-off between frequency and time resolution. The technique is convenient as it can be done in the same conditions as for plasma measurements. The method is in use on the EAST profile reflectometer, and results will be presented. Work was supported by the Natural Science Foundation of China (NSFC) under 11475173, National Magnetic Confinement Fusion Energy Development Program of China under 2013GB106002 and 2014GB109002, and US DOE Grants DE- SC0010424 and DE-SC0010469.

  2. Iterative noise removal from temperature and density profiles in the TJ-II Thomson scattering

    Energy Technology Data Exchange (ETDEWEB)

    Farias, G., E-mail: gonzalo.farias@ucv.cl [Pontificia Universidad Católica de Valparaíso, Av. Brasil 2147, Valparaíso (Chile); Dormido-Canto, S., E-mail: sebas@dia.uned.es [Departamento de Informática y Automática, UNED, 28040 Madrid (Spain); Vega, J., E-mail: jesus.vega@ciemat.es [Asociación EURATOM/CIEMAT para Fusión, Avd. Complutense 22, 28040 Madrid (Spain); Santos, M., E-mail: msantos@ucm.es [Departamento de Arquitectura de Computadores y Automática, Universidad Complutense de Madrid, 28040 Madrid (Spain); Pastor, I., E-mail: ignacio.pastor@ciemat.es [Asociación EURATOM/CIEMAT para Fusión, Avd. Complutense 22, 28040 Madrid (Spain); Fingerhuth, S., E-mail: sebastian.fingerhuth@ucv.cl [Pontificia Universidad Católica de Valparaíso, Av. Brasil 2147, Valparaíso (Chile); Ascencio, J., E-mail: j_ascencio21@hotmail.com [Pontificia Universidad Católica de Valparaíso, Av. Brasil 2147, Valparaíso (Chile)

    2014-05-15

    TJ-II Thomson Scattering diagnostic provides temperature and density profiles of plasma. The CCD camera acquires images that are corrupted with some kind of noise called stray-light. This noise degrades both image contrast and measurement accuracy, which could produce unreliable profiles of the diagnostic. So far, several approaches have been applied in order to decrease the noise in the TJ-II Thomson scattering images. Since the presence of the noise is not global but located in some particular regions of the image, advanced processing techniques are needed. However such methods require of manual fine-tuning of parameters to reach a good performance. In this contribution, an iterative image processing approach is applied in order to reduce the stray light effects in the images of the TJ-II Thomson scattering diagnostic. The proposed solution describes how the noise can be iteratively reduced in the images when a key parameter is automatically adjusted during the iterative process.

  3. Modelling of the electron density height profiles in the mid-latitude ionospheric D-region

    Directory of Open Access Journals (Sweden)

    P. Y. Mukhtarov

    1996-06-01

    Full Text Available A new mid-latitude D-region (50-105 km model of the electron density is presented obtained on the basis of a full wave theory and by a trial-and-error inversion method. Daytime (at different solar zenith angles absorption measurements by A3-technique made in Bulgaria yielded data with the aid of which the seasonal and diurnal courses of the Ne(h-profiles were derived. Special attention is drawn to the event diurnal asymmetry, or uneven formation of the ionosphere as a function of insulation. The latter is probably connected with the influence of the diurnal fluctuations in the local temperature on the chemistry involved in the electron loss rate, as well as the diurnal variations of the main ionizing agent (NO in the D-region. That is why the Ne(h-profiles in the midlatitude D-region are modelled separately for morning and afternoon hours.

  4. Flow Rate of Particles through Apertures Obtained from Self-Similar Density and Velocity Profiles

    Science.gov (United States)

    Janda, Alvaro; Zuriguel, Iker; Maza, Diego

    2012-06-01

    “Beverloo’s law” is considered as the standard expression to estimate the flow rate of particles through apertures. This relation was obtained by simple dimensional analysis and includes empirical parameters whose physical meaning is poorly justified. In this Letter, we study the density and velocity profiles in the flow of particles through an aperture. We find that, for the whole range of apertures studied, both profiles are self-similar. Hence, by means of the functionality obtained for them the mass flow rate is calculated. The comparison of this expression with the Beverloo’s one reveals some differences which are crucial to understanding the mechanism that governs the flow of particles through orifices.

  5. On the shape of the common carotid artery with implications for blood velocity profiles.

    Science.gov (United States)

    Manbachi, Amir; Hoi, Yiemeng; Wasserman, Bruce A; Lakatta, Edward G; Steinman, David A

    2011-12-01

    Clinical and engineering studies typically assume that the common carotid artery (CCA) is straight enough to assume fully developed flow, yet recent studies have demonstrated the presence of skewed velocity profiles. Toward elucidating the influence of mild vascular curvatures on blood flow patterns and atherosclerosis, this study aimed to characterize the three-dimensional shape of the human CCA. The left and right carotid arteries of 28 participants (63 ± 12 years) in the VALIDATE (Vascular Aging--The Link that Bridges Age to Atherosclerosis) study were digitally segmented from 3D contrast-enhanced magnetic resonance angiograms, from the aortic arch to the carotid bifurcation. Each CCA was divided into nominal cervical and thoracic segments, for which curvatures were estimated by least-squares fitting of the respective centerlines to planar arcs. The cervical CCA had a mean radius of curvature of 127 mm, corresponding to a mean lumen:curvature radius ratio of 1:50. The thoracic CCA was significantly more curved at 1:16, with the plane of curvature tilted by a mean angle of 25° and rotated close to 90° with respect to that of the cervical CCA. The left CCA was significantly longer and slightly more curved than the right CCA, and there was a weak but significant increase in CCA curvature with age. Computational fluid dynamic simulations carried out for idealized CCA geometries derived from these and other measured geometric parameters demonstrated that mild cervical curvature is sufficient to prevent flow from fully-developing to axisymmetry, independent of the degree of thoracic curvature. These findings reinforce the idea that fully developed flow may be the exception rather than the rule for the CCA, and perhaps other nominally long and straight vessels.

  6. Near-Infrared Properties of Moderate-Redshift Galaxy Clusters: Luminosity Functions and Density Profiles

    Energy Technology Data Exchange (ETDEWEB)

    Muzzin, Adam; Yee, H.K.C.; /Toronto U., Astron. Dept.; Hall, Patrick B.; /York U., Canada; Ellingson, E.; /Colorado U., CASA; Lin, Huan; /Fermilab

    2006-12-01

    We present K-band imaging for 15 of the Canadian Network for Observational Cosmology (CNOC1) clusters. The extensive spectroscopic dataset available for these clusters allows us to determine the cluster K-band luminosity function and density profile without the need for statistical background subtraction. The luminosity density and number density profiles can be described by NFW models with concentration parameters of c{sub l} = 4.28 {+-} 0.70 and c{sub g} = 4.13 {+-} 0.57 respectively. Comparing these to the dynamical mass analysis of the same clusters shows that the galaxy luminosity and number density profiles are similar to the dark matter profile, and are not less concentrated like in local clusters. The luminosity functions show that the evolution of K. over the redshift range 0.2 < z < 0.5 is consistent with a scenario where the majority of stars in cluster galaxies form at high-redshift (z{sub f} > 1.5) and evolve passively thereafter. The best-fit for the faint-end slope of the luminosity function is {alpha} = -0.84 {+-} 0.08, which indicates that it does not evolve between z = 0 and z = 0.3. Using Principal Component Analysis of the spectra we classify cluster galaxies as either star-forming/recently-star-forming (EM+BAL) or non-star forming (ELL) and compute their respective luminosity functions. The faint-end slope of the ELL luminosity function is much shallower than for the EM+BAL galaxies at z = 0.3, and suggests the number of faint ELL galaxies in clusters decreases by a factor of {approx} 3 from z = 0 to z = 0.3. The redshift evolution of K* for both EM+BAL and ELL types is consistent with a passively evolving stellar population formed at high-redshift. Passive evolution in both classes, as well as the total cluster luminosity function, demonstrates that the bulk of the stellar population in all bright cluster galaxies is formed at high-redshift and subsequent transformations in morphology/color/spectral-type have little effect on the total stellar

  7. Force-free collisionless current sheet models with non-uniform temperature and density profiles

    Science.gov (United States)

    Wilson, F.; Neukirch, T.; Allanson, O.

    2017-09-01

    We present a class of one-dimensional, strictly neutral, Vlasov-Maxwell equilibrium distribution functions for force-free current sheets, with magnetic fields defined in terms of Jacobian elliptic functions, extending the results of Abraham-Shrauner [Phys. Plasmas 20, 102117 (2013)] to allow for non-uniform density and temperature profiles. To achieve this, we use an approach previously applied to the force-free Harris sheet by Kolotkov et al. [Phys. Plasmas 22, 112902 (2015)]. In one limit of the parameters, we recover the model of Kolotkov et al. [Phys. Plasmas 22, 112902 (2015)], while another limit gives a linear force-free field. We discuss conditions on the parameters such that the distribution functions are always positive and give expressions for the pressure, density, temperature, and bulk-flow velocities of the equilibrium, discussing the differences from previous models. We also present some illustrative plots of the distribution function in velocity space.

  8. Evolution of density and velocity profiles of dark matter and dark energy in spherical voids

    CERN Document Server

    Novosyadlyj, Bohdan; Kulinich, Yurij

    2016-01-01

    We analyse the evolution of cosmological perturbations which leads to the formation of large isolated voids in the Universe. We assume that initial perturbations are spherical and all components of the Universe (radiation, matter and dark energy) are continuous media with perfect fluid energy-momentum tensors, which interact only gravitationally. Equations of the evolution of perturbations for every component in the comoving to cosmological background reference frame are obtained from equations of energy and momentum conservation and Einstein's ones and are integrated numerically. Initial conditions are set at the early stage of evolution in the radiation-dominated epoch, when the scale of perturbation is much larger than the particle horizon. Results show how the profiles of density and velocity of matter and dark energy are formed and how they depend on parameters of dark energy and initial conditions. In particular, it is shown that final matter density and velocity amplitudes change within range $\\sim$4-7...

  9. Ultrahigh-resolution spectroscopy with atomic or molecular dark resonances: Exact steady-state line shapes and asymptotic profiles in the adiabatic pulsed regime

    Energy Technology Data Exchange (ETDEWEB)

    Zanon-Willette, Thomas; Clercq, Emeric de; Arimondo, Ennio [UPMC Univ. Paris 06, UMR 7092, LPMAA, 4 place Jussieu, case 76, F-75005 Paris, France, and CNRS, UMR 7092, LPMAA, 4 place Jussieu, case 76, F-75005 Paris (France); LNE-SYRTE, Observatoire de Paris, CNRS, UPMC, 61 avenue de l' Observatoire, F-75014 Paris (France); Dipartimento di Fisica ' ' E. Fermi,' ' Universita di Pisa, Lgo. B. Pontecorvo 3, I-56122 Pisa (Italy)

    2011-12-15

    Exact and asymptotic line shape expressions are derived from the semiclassical density matrix representation describing a set of closed three-level {Lambda} atomic or molecular states including decoherences, relaxation rates, and light shifts. An accurate analysis of the exact steady-state dark-resonance profile describing the Autler-Townes doublet, the electromagnetically induced transparency or coherent population trapping resonance, and the Fano-Feshbach line shape leads to the linewidth expression of the two-photon Raman transition and frequency shifts associated to the clock transition. From an adiabatic analysis of the dynamical optical Bloch equations in the weak field limit, a pumping time required to efficiently trap a large number of atoms into a coherent superposition of long-lived states is established. For a highly asymmetrical configuration with different decay channels, a strong two-photon resonance based on a lower states population inversion is established when the driving continuous-wave laser fields are greatly unbalanced. When time separated resonant two-photon pulses are applied in the adiabatic pulsed regime for atomic or molecular clock engineering, where the first pulse is long enough to reach a coherent steady-state preparation and the second pulse is very short to avoid repumping into a new dark state, dark-resonance fringes mixing continuous-wave line shape properties and coherent Ramsey oscillations are created. Those fringes allow interrogation schemes bypassing the power broadening effect. Frequency shifts affecting the central clock fringe computed from asymptotic profiles and related to the Raman decoherence process exhibit nonlinear shapes with the three-level observable used for quantum measurement. We point out that different observables experience different shifts on the lower-state clock transition.

  10. Neutral-depletion-induced asymmetric plasma density profile and momentum transport in a helicon thruster

    Science.gov (United States)

    Takahashi, Kazunori; Takao, Yoshinori; Chiba, Aiki; Ando, Akira

    2016-09-01

    Axial momentum lost to a lateral wall of a helicon source is directly measured by using a pendulum force balance, where only the lateral wall is attached to the balance immersed in 60-cm-diam and 1.4-m-long vacuum tank (pumping speed of 300-400 L/s). When operating the source with highly ionized krypton and xenon, the strong density decay along the axis is observed inside the source tube, which seems to be due to the neutral depletion. Under such a condition, a non-negligible loss of the axial momentum to the lateral wall is detected. The presently detected loss of the axial momentum indicates the presence of the ions which are axially accelerated by the electric field in the plasma core and then lost to the lateral wall. Furthermore, the helicon thruster immersed in 1-m-diam and 2-m-long vacuum tank (pumping speed of 4000-5000 L/s) is operated at high rf power up to 5 kW in argon, to demonstrate the neutral-depletion-induced axially asymmetric density profile. Combination between the Langmuir probe and the optical diagnosis indicates that the neutral density at the axial center of the source is reduced to 20% of the initial neutral density. This work is partially supported by grant-in-aid for scientific research (16H04084 and 26247096) from the Japan Society for the Promotion of Science.

  11. Forward Modeling of the 2003 November 14 Titan Occultation: New Retrievals of Temperature, Density and Opacity Profiles from about 350 to 500 km

    Science.gov (United States)

    Young, E. F.; Zalucha, A.

    2012-04-01

    On 2003 November 14, Titan occulted a relatively bright star (V = 10.7). This event was observed from La Palma Observatory using ULTRACAM in three simultaneous wavelengths (358, 487 and 758 nm), as reported by Zalucha et al. (2007). The event was near-central, but only the long-wavelength light curves show a central flash. Zalucha et al. (2007) extracted temperature profiles from 350 to 485 km, estimated the altitudes where line-of-sight aerosol optical depths are one in the three ULTRACAM filters and fit the three-peaked central flash feature to atmospheric shape models that are comparable to those used by Hubbard et al. (1993) in the 28 Sgr occultation. We now use a more flexible forward-modeling approach to re-examine the ULTRACAM light curves. The output of this effort is a thin-screen representation of Titan’s upper atmosphere consisting of line-of-sight opacities and phase delays - it is a flexible technique to simultaneously retrieve extinction and refractivity profiles and bulk atmospheric shape. We will present temperature, density and opacity profiles that are consistent with the retrieved thin-screen model and compare model light curves generated from HASI temperature profiles to the occultation observations. References: Zalucha, A., et al.: "The 2003 November 14 occultation by Titan of TYC 1343-1865-1 II. Analysis of light curves". Icarus, Vol. 197, pp. 503-518, 2007.

  12. Shape, Density, and Geology of the Nucleus of Comet 103P/Hartley 2

    Science.gov (United States)

    Thomas, P.C.; A'hearn, Michael F.; Veverka, Joseph; Belton, Michael J. S.; Kissel, Jochen; Belton, Michael J. S.; Klaasen, Kenneth P.; McFadden, Lucy A.; Melosh, H. Jay; Schultz, Peter H.; Besse, Sebastien; Carcich, Brian T.; Farnham, Tony L.; Groussin, Olivier; Hermalyn, Brendan; Li, Jian-Yang; Lindler, Don J.; Lisse, Carey M.; Meech, Karen; Richardson, James E.

    2013-01-01

    Data from the Extrasolar Planet Observation and Deep Impact Extended Investigation (EPOXI) mission show Comet 103P/Hartley 2 is a bi-lobed, elongated, nearly axially symmetric comet 2.33 km in length. Surface features are primarily small mounds 1%. The shape may be the evolutionary product of insolation, sublimation, and temporary deposition of materials controlled by the object’s complex rotation.

  13. Shape-dependence of transmission, reflection and absorption eigenvalue densities in disordered waveguides with dissipation

    CERN Document Server

    Yamilov, A; Sarma, R; Cao, H

    2015-01-01

    The universal bimodal distribution of transmission eigenvalues in lossless diffusive systems un- derpins such celebrated phenomena as universal conductance fluctuations, quantum shot noise in condensed matter physics and enhanced transmission in optics and acoustics. Here, we show that in the presence of absorption, density of the transmission eigenvalues depends on the confinement geometry of scattering media. Furthermore, in an asymmetric waveguide, densities of the reflection and absorption eigenvalues also depend of the side from which the waves are incident. With increas- ing absorpotion, the density of absorption eigenvalues transforms from single-peak to double-peak function. Our findings open a new avenue for coherent control of wave transmission, reflection and absorption in random media.

  14. Gravitational acceleration and tidal effects in spherical-symmetric density profiles

    CERN Document Server

    Caimmi, R

    2015-01-01

    Pure power-law density profiles, $\\rho(r)\\propto r^{b-3}$, are classified in connection with the following reference cases: (i) isodensity, $b=3$, $\\rho=$ const; (ii) isogravity, $b=2$, $g=$ const; (iii) isothermal, $b=1$, $v=[GM(r)/r]^{1/2}=$ const; (iv) isomass, $b=0$, $M=$ const. A restricted number of different families of density profiles including, in addition, cored power-law, generalized power-law, polytropes, are studied in detail with regard to both one-component and two-component systems. Considerable effort is devoted to the existence of an extremum point (maximum absolute value) in the gravitational acceleration within the matter distribution. Predicted velocity curves are compared to the data inferred from observations. Tidal effects on an inner subsystem are investigated and an application is made to globular clusters within the Galaxy. To this aim, the tidal radius is defined by balancing the opposite gravitational forces from the Galaxy and the selected cluster on a special point of the clust...

  15. Aluminum integral foams with tailored density profile by adapted blowing agents

    Science.gov (United States)

    Hartmann, Johannes; Fiegl, Tobias; Körner, Carolin

    2014-05-01

    The goal of the present work is the variation of the structure of aluminum integral foams regarding the thickness of the integral solid skin as well as the density profile. A modified die casting process, namely integral foam molding, is used in which an aluminum melt and blowing agent particles (magnesium hydride MgH2) are injected in a permanent steel mold. The high solidification rates at the cooled walls of the mold lead to the formation of a solid skin. In the inner region, hydrogen is released by thermal decomposition of MgH2 particles. Thus, the pore formation takes place parallel to the continuing solidification of the melt. The thickness of the solid skin and the density profile of the core strongly depend on the interplay between solidification velocity and kinetics of hydrogen release. By varying the melt and blowing agent properties, the structure of integral foams can be systematically changed to meet the requirements of the desired field of application of the produced component.

  16. Detecting reduced bone mineral density from dental radiographs using statistical shape models

    NARCIS (Netherlands)

    Allen, P.D.; Graham, J.; Farnell, D.J.J.; Harrison, E.J.; Jacobs, R.; Nicopoulou-Karyianni, K.; Lindh, C.; van der Stelt, P.F.; Horner, K.; Devlin, H.

    2007-01-01

    We describe a novel method of estimating reduced bone mineral density (BMD) from dental panoramic tomograms (DPTs), which show the entire mandible. Careful expert width measurement of the inferior mandibular cortex has been shown to be predictive of BMD in hip and spine osteopenia and osteoporosis.

  17. Effect of voltage shape of electrical power supply on radiation and density of a cold atmospheric argon plasma jet

    Directory of Open Access Journals (Sweden)

    F Sohbatzadeh

    2017-02-01

    Full Text Available In this work, we investigated generating argon cold plasma jet at atmospheric pressure based on dielectric barrier discharge configuration using three electrical power supplies of sinusoidal, pulsed and saw tooth high voltage shapes at 8 KHZ. At first; we describe the electronic circuit features for generating high voltage (HV wave forms including saw tooth, sinusoidal and pulsed forms. Then, we consider the effect of voltage shape on the electrical breakdown. Relative concentrations of chemical reactive species such as Oxygen, atomic Nitrogen and OH were measured using optical emission spectroscopy. Using a simple numerical model, we showed a HV with less rise time increases electron density, therefore a cold plasma jet can be produced with a minimal consumption electrical power

  18. Evolution of Density Profiles in High-z Galaxies: Compaction and Quenching Inside-Out

    CERN Document Server

    Tacchella, Sandro; Carollo, C Marcella; Ceverino, Daniel; DeGraf, Colin; Lapiner, Sharon; Mandelker, Nir; Primack, Joel R

    2015-01-01

    Using cosmological simulations, we address the interplay between structure and star formation in high-redshift galaxies via the evolution of surface density profiles. Our sample consists of 26 galaxies evolving in the redshift range $z=7-1$, spanning the stellar mass range $(0.2-6.4)\\times 10^{10}M_\\odot$ at $z=2$. We recover the main trends by stacking the profiles in accordance to their evolution phases. Following a wet compaction event that typically occurs when the stellar mass is $\\sim10^{9.5}~M_{\\odot}$ at $z\\sim2-4$, the gas develops a cusp inside the effective radius, associated with a peak in star-formation rate (SFR). The SFR peak and the associated feedback, in the absence of further gas inflow to the centre, marks the onset of gas depletion from the central 1 kpc, leading to quenching of the central SFR. An extended, star-forming ring that forms by fresh gas during the central quenching process shows as a rising specific SFR (sSFR) profile, which is interpreted as inside-out quenching. Before quen...

  19. Relation between the change of density of states and the shape of the potential in two-body interactions

    Science.gov (United States)

    Gao, Bo

    2017-04-01

    We derive a general relation in two-body scattering theory that more directly relates the change of density of states (DDOS) due to interaction to the shape of the potential. The relation allows us to infer certain global properties of the DDOS from the global properties of the potential. In particular, we show that DDOS is negative at all energies and for all partial waves, for potentials that are more repulsive than +1 /r2 everywhere. This behavior represents a different class of global properties of DDOS from that described by the Levinson's theorem.

  20. Impact of a hollow density profile on turbulent particle fluxes: Gyrokinetic and fluid simulations

    Science.gov (United States)

    Tegnered, D.; Oberparleiter, M.; Strand, P.; Nordman, H.

    2017-07-01

    Hollow density profiles may occur in connection with pellet fuelling and L to H transitions. A positive density gradient could potentially stabilize the turbulence or change the relation between convective and diffusive fluxes, thereby reducing the turbulent transport of particles towards the center, making the pellet fuelling scheme inefficient. In the present work, the particle transport driven by Ion Temperature Gradient/Trapped Electron (ITG/TE) mode turbulence in hollow density profiles is studied by fluid as well as gyrokinetic simulations. The fluid model used, an extended version of the Weiland transport model, Extended Drift Wave Model (EDWM), incorporates an arbitrary number of ion species in a multi-fluid description and an extended wavelength spectrum. The fluid model, which is fast and hence suitable for use in predictive simulations, is compared to gyrokinetic simulations using the code GENE. Typical tokamak parameters are used based on the Cyclone Base Case. Parameter scans in key plasma parameters like plasma β, R/LT, and magnetic shear are investigated. In addition, the effects of a fast species are studied and global ITG simulations in a simplified physics description are performed in order to investigate nonlocal effects. It is found that β in particular, has a stabilizing effect in the negative R/Ln region. Both nonlinear GENE and EDWM simulations show a decrease in inward flux for negative R/Ln and a change in the direction from inward to outward for positive R/Ln. Moreover, the addition of fast particles was shown to decrease the inward main ion particle flux in the positive gradient region further. This might have serious consequences for pellet fuelling of high β plasmas. Additionally, the heat flux in global ITG turbulence simulations indicates that nonlocal effects can play a different role from usual in connection with pellet fuelling.

  1. A LOFAR census of non-recycled pulsars: average profiles, dispersion measures, flux densities, and spectra

    CERN Document Server

    Bilous, A; Kramer, M; Keane, E; Hessels, J; Stappers, B; Malofeev, V; Sobey, C; Breton, R; Cooper, S; Falcke, H; Karastergiou, A; Michilli, D; Osłowski, S; Sanidas, S; ter Veen, S; van Leeuwen, J; Verbiest, J; Weltevrede, P; Zarka, P; Grießmeier, J -M; Serylak, M; Bell, M; Broderick, J; Eislöffel, J; Markoff, S; Rowlinson, A

    2015-01-01

    We present first results from a LOFAR census of non-recycled pulsars. The census includes almost all such pulsars known (194 sources) at declinations Dec$> 8^\\circ$ and Galactic latitudes |Gb|$> 3^\\circ$, regardless of their expected flux densities and scattering times. Each pulsar was observed contiguously in the frequency range from 110$-$188 MHz and for $\\geq 20$ minutes, recording full-Stokes data. We present the dispersion measures, flux densities, and calibrated total intensity profiles for the 158 pulsars detected in the sample. The median uncertainty in census dispersion measures ($1.5 \\times 10^{-4}$ pc cm$^{-3}$) is ten times smaller, on average, than in the ATNF pulsar catalogue. We combined census flux densities with those in the literature and fitted the resulting broadband spectra with single or broken power-law functions. For 48 census pulsars such fits are being published for the first time. Typically, the choice between single and broken power-laws, as well as the location of the spectral bre...

  2. The Surface Density Profile of the Galactic Disk from the Terminal Velocity Curve

    CERN Document Server

    McGaugh, Stacy S

    2015-01-01

    The mass distribution of the Galactic disk is constructed from the terminal velocity curve and the mass discrepancy-acceleration relation. Mass models numerically quantifying the detailed surface density profiles are tabulated. For $R_0 = 8$ kpc, the models have stellar mass $5 < M_* < 6 \\times 10^{10}$ M$_{\\odot}$, scale length $2.0 \\le R_d \\le 2.9$ kpc, LSR circular velocity $222 \\le \\Theta_0 \\le 233$ km s$^{-1}$, and solar circle stellar surface density $34 \\le \\Sigma_d(R_0) \\le 61$ M$_{\\odot}$ pc$^{-2}$. The present inter-arm location of the solar neighborhood may have a somewhat lower stellar surface density than average for the solar circle. The Milky Way appears to be a normal spiral galaxy that obeys scaling relations like the Tully-Fisher relation, the size-mass relation, and the disk maximality-surface brightness relation. The stellar disk is maximal, and the spiral arms are massive. The bumps and wiggles in the terminal velocity curve correspond to known spiral features (e.g., the Centaurus A...

  3. Radial Density Profile in the SSX Plasma Wind Tunnel using a Double Langmuir Probe

    Science.gov (United States)

    Weinhold, D. L.; Flanagan, K.; Gray, T.; Brown, M. R.

    2011-10-01

    We present preliminary results from a moveable double Langmuir probe in the present plasma wind tunnel configuration of SSX. The probe is designed to measure radial profiles of electron density (ne) and electron temperature (Te) across the midplane with a 1 cm resolution. Line-averaged densities from He-Ne interferometry show densities of 1 - 5 ×1015 cm-3 . In addition to mean values, we will also present electrostatic fluctuations and correlations with magnetic field measurements. The double Langmuir probe also measures local Te. Line-averaged measurements from VUV spectroscopy indicate Te ~ 10 eV . The Langmuir probe stalk diameter measures 6 . 5 mm and tip spacing is 1 . 1 mm . The SSX plasma wind tunnel has dimensions L ≅ 1 m and R = 0 . 08 m . Plasma flow speeds are v >= 50 km / s . The cylindrical copper boundary and probe surfaces are baked and cleaned in a He glow discharge to maintain excellent vacuum and surface conditions. Electrostatic measurements during merging will be presented if available. Work supported by US DOE and CMSO.

  4. Stellar density profile and mass of the Milky Way Bulge from VVV data

    CERN Document Server

    Valenti, E; Gonzalez, O A; Minniti, D; Alonso-Garcia, J; Marchetti, E; Hempel, M; Renzini, A; Rejkuba, M

    2015-01-01

    We present the first stellar density profile of the Milky Way bulge reaching latitude $b=0^\\circ$. It is derived by counting red clump stars within the colour\\--magnitude diagram constructed with the new PSF-fitting photometry from VISTA Variables in the V\\'\\i a L\\'actea (VVV) survey data. The new stellar density map covers the area between $|l|\\leq 10^\\circ$ and $|b|\\leq 4.5^\\circ$ with unprecedented accuracy, allowing to establish a direct link between the stellar kinematics from the Giraffe Inner Bulge Spectroscopic Survey (GIBS) and the stellar mass density distribution. In particular, the location of the central velocity dispersion peak from GIBS matches a high overdensity in the VVV star count map. By scaling the total luminosity function (LF) obtained from all VVV fields to the LF from Zoccali et al.(2003), we obtain the first fully empirical estimate of the mass in stars and remnants of the Galactic bulge. The Milky Way bulge stellar mass within ($|b|<9.5^\\circ$, $|l|<10^\\circ$) is $2.0\\pm0.3\\ti...

  5. Speckle measurements of density and temperature profiles in a model gas circuit breaker

    Science.gov (United States)

    Stoller, P. C.; Panousis, E.; Carstensen, J.; Doiron, C. B.; Färber, R.

    2015-01-01

    Speckle imaging was used to measure the density and temperature distribution in the arc zone of a model high voltage circuit breaker during the high current phase and under conditions simulating those present during current-zero crossings (current-zero-like arc); the arc was stabilized by a transonic, axial flow of synthetic air. A single probe beam was used; thus, accurate reconstruction was only possible for axially symmetric gas flows and arc channels. The displacement of speckles with respect to a reference image was converted to a line-of-sight integrated deflection angle, which was in turn converted into an axially symmetric refractive index distribution using a multistep process that made use of the inverse Radon transform. The Gladstone-Dale relation, which gives the index of refraction as a function of density, was extended to high temperatures by taking into account dissociation and ionization processes. The temperature and density were determined uniquely by assuming that the pressure distribution in the case of cold gas flow (in the absence of an arc) is not modified significantly by the arc. The electric conductivity distribution was calculated from the temperature profile and compared to measurements of the arc voltage and to previous results published in the literature for similar experimental conditions.

  6. A parametric approach to shape field-relevant blast wave profiles in compressed-gas-driven shock tube.

    Science.gov (United States)

    Sundaramurthy, Aravind; Chandra, Namas

    2014-01-01

    Detonation of a high-explosive produces shock-blast wave, shrapnel, and gaseous products. While direct exposure to blast is a concern near the epicenter, shock-blast can affect subjects, even at farther distances. When a pure shock-blast wave encounters the subject, in the absence of shrapnels, fall, or gaseous products the loading is termed as primary blast loading and is the subject of this paper. The wave profile is characterized by blast overpressure, positive time duration, and impulse and called herein as shock-blast wave parameters (SWPs). These parameters in turn are uniquely determined by the strength of high explosive and the distance of the human subjects from the epicenter. The shape and magnitude of the profile determine the severity of injury to the subjects. As shown in some of our recent works (1-3), the profile not only determines the survival of the subjects (e.g., animals) but also the acute and chronic biomechanical injuries along with the following bio-chemical sequelae. It is extremely important to carefully design and operate the shock tube to produce field-relevant SWPs. Furthermore, it is vital to identify and eliminate the artifacts that are inadvertently introduced in the shock-blast profile that may affect the results. In this work, we examine the relationship between shock tube adjustable parameters (SAPs) and SWPs that can be used to control the blast profile; the results can be easily applied to many of the laboratory shock tubes. Further, replication of shock profile (magnitude and shape) can be related to field explosions and can be a standard in comparing results across different laboratories. Forty experiments are carried out by judiciously varying SAPs such as membrane thickness, breech length (66.68-1209.68 mm), measurement location, and type of driver gas (nitrogen, helium). The effects SAPs have on the resulting shock-blast profiles are shown. Also, the shock-blast profiles of a TNT explosion from ConWep software is compared

  7. Covariant density functional analysis of shape evolution in $N =40$ isotones

    CERN Document Server

    Wang, Z H; Long, W H; Li, Z P

    2014-01-01

    The structure of low-lying excitation states of even-even $N=40$ isotones is studied using a five-dimensional collective Hamiltonian with the collective parameters determined from the relativistic mean-field plus BCS method with the PC-PK1 functional in the particle-hole channel and a separable paring force in the particle-particle channel. The theoretical calculations can reproduce not only the systematics of the low-lying states along the isotonic chain but also the detailed structure of the spectroscopy in a single nucleus. We find a picture of spherical-oblate-prolate shape transition along the isotonic chain of $N=40$ by analyzing the potential energy surfaces. The coexistence of low-lying excited $0^+$ states has also been shown to be a common feature in neutron-deficient $N=40$ isotones.

  8. Dark matter density profiles of the halos embedding early-type galaxies: characterizing halo contraction and dark matter annihilation strength

    CERN Document Server

    Chae, Kyu-Hyun; Frieman, Joshua A; Bernardi, Mariangela

    2012-01-01

    Identifying dark matter and characterizing its distribution in the inner region of halos embedding galaxies are inter-related problems of broad importance. We devise a new procedure of determining dark matter distribution in halos. We first make a self-consistent bivariate statistical match of stellar mass and velocity dispersion with halo mass as demonstrated here for the first time. Then, selecting early-type galaxy-halo systems we perform Jeans dynamical modeling with the aid of observed statistical properties of stellar mass profiles and velocity dispersion profiles. Dark matter density profiles derived specifically using Sloan Digital Sky Survey galaxies and halos from up-to-date cosmological dissipationless simulations deviate significantly from the dissipationless profle of Navarro-Frenk-White or Einasto in terms of inner density slope and/or concentration. From these dark matter profiles we find that dark matter density is enhanced in the inner region of most early-type galactic halos providing an ind...

  9. Measurement of heat load density profile on acceleration grid in MeV-class negative ion accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Hiratsuka, Junichi, E-mail: hiratsuka.junichi@jaea.go.jp; Hanada, Masaya; Kojima, Atsushi; Umeda, Naotaka; Kashiwagi, Mieko; Yoshida, Masafumi; Nishikiori, Ryo; Ichikawa, Masahiro; Watanabe, Kazuhiro; Tobari, Hiroyuki [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka 311-0193 (Japan); Miyamoto, Kenji [Naruto University of Education, 748 Nakashima, Takashima, Naruto-cho, Naruto-shi, Tokushima 772-8502 (Japan)

    2016-02-15

    To understand the physics of the negative ion extraction/acceleration, the heat load density profile on the acceleration grid has been firstly measured in the ITER prototype accelerator where the negative ions are accelerated to 1 MeV with five acceleration stages. In order to clarify the profile, the peripheries around the apertures on the acceleration grid were separated into thermally insulated 34 blocks with thermocouples. The spatial resolution is as low as 3 mm and small enough to measure the tail of the beam profile with a beam diameter of ∼16 mm. It was found that there were two peaks of heat load density around the aperture. These two peaks were also clarified to be caused by the intercepted negative ions and secondary electrons from detailed investigation by changing the beam optics and gas density profile. This is the first experimental result, which is useful to understand the trajectories of these particles.

  10. Integration of tomato reproductive developmental landmarks and expression profiles, and the effect of SUN on fruit shape

    Directory of Open Access Journals (Sweden)

    Li Dongmei

    2009-05-01

    Full Text Available Abstract Background Universally accepted landmark stages are necessary to highlight key events in plant reproductive development and to facilitate comparisons among species. Domestication and selection of tomato resulted in many varieties that differ in fruit shape and size. This diversity is useful to unravel underlying molecular and developmental mechanisms that control organ morphology and patterning. The tomato fruit shape gene SUN controls fruit elongation. The most dramatic effect of SUN on fruit shape occurs after pollination and fertilization although a detailed investigation into the timing of the fruit shape change as well as gene expression profiles during critical developmental stages has not been conducted. Results We provide a description of floral and fruit development in a red-fruited closely related wild relative of tomato, Solanum pimpinellifolium accession LA1589. We use established and propose new floral and fruit landmarks to present a framework for tomato developmental studies. In addition, gene expression profiles of three key stages in floral and fruit development are presented, namely floral buds 10 days before anthesis (floral landmark 7, anthesis-stage flowers (floral landmark 10 and fruit landmark 1, and 5 days post anthesis fruit (fruit landmark 3. To demonstrate the utility of the landmarks, we characterize the tomato shape gene SUN in fruit development. SUN controls fruit shape predominantly after fertilization and its effect reaches a maximum at 8 days post-anthesis coinciding with fruit landmark 4 representing the globular embryo stage of seed development. The expression profiles of the NILs that differ at sun show that only 34 genes were differentially expressed and most of them at a less than 2-fold difference. Conclusion The landmarks for flower and fruit development in tomato were outlined and integrated with the effect of SUN on fruit shape. Although we did not identify many genes differentially expressed in

  11. Integration of tomato reproductive developmental landmarks and expression profiles, and the effect of SUN on fruit shape

    Science.gov (United States)

    Xiao, Han; Radovich, Cheryll; Welty, Nicholas; Hsu, Jason; Li, Dongmei; Meulia, Tea; van der Knaap, Esther

    2009-01-01

    Background Universally accepted landmark stages are necessary to highlight key events in plant reproductive development and to facilitate comparisons among species. Domestication and selection of tomato resulted in many varieties that differ in fruit shape and size. This diversity is useful to unravel underlying molecular and developmental mechanisms that control organ morphology and patterning. The tomato fruit shape gene SUN controls fruit elongation. The most dramatic effect of SUN on fruit shape occurs after pollination and fertilization although a detailed investigation into the timing of the fruit shape change as well as gene expression profiles during critical developmental stages has not been conducted. Results We provide a description of floral and fruit development in a red-fruited closely related wild relative of tomato, Solanum pimpinellifolium accession LA1589. We use established and propose new floral and fruit landmarks to present a framework for tomato developmental studies. In addition, gene expression profiles of three key stages in floral and fruit development are presented, namely floral buds 10 days before anthesis (floral landmark 7), anthesis-stage flowers (floral landmark 10 and fruit landmark 1), and 5 days post anthesis fruit (fruit landmark 3). To demonstrate the utility of the landmarks, we characterize the tomato shape gene SUN in fruit development. SUN controls fruit shape predominantly after fertilization and its effect reaches a maximum at 8 days post-anthesis coinciding with fruit landmark 4 representing the globular embryo stage of seed development. The expression profiles of the NILs that differ at sun show that only 34 genes were differentially expressed and most of them at a less than 2-fold difference. Conclusion The landmarks for flower and fruit development in tomato were outlined and integrated with the effect of SUN on fruit shape. Although we did not identify many genes differentially expressed in the NILs that differ at

  12. Determination of stratospheric temperature and density by GOMOS: Verification with respect to high latitude LIDAR profiles from Thule, Greenland

    Science.gov (United States)

    di Sarra, A.; Iannone, R. Q.; Casadio, S.; Di Biagio, C.; Pace, G.; Cacciani, M.; Muscari, G.; Dehn, A.; Bojkov, B.

    2017-02-01

    High resolution temperature profiles (HRTP) have been derived from measurements performed by Global Ozone Monitoring by Occultation of Stars (GOMOS) onboard ENVISAT. HRTP are derived from measurements with two fast photometers whose signal is sampled at 1 kHz, and allows investigating the role of irregularities in the density and temperature profiles, such as those associated with gravity waves. In this study high resolution temperature and density profiles measured at high latitude by GOMOS are compared with observations made with the ground-based aerosol/temperature LIDAR at Thule, Greenland. The LIDAR at Thule contributes to the Network for the Detection of Atmospheric Composition Change. The LIDAR profiles are analyzed in the height interval overlapping with GOMOS data (22-35 km), and the density and temperature profiles are obtained with 250 m vertical resolution. The comparison is focused on data collected during the 2008-2009 and 2009-2010 Arctic winters. Profiles measured within 6 hours and 500 km are selected. The profiles are classified based on spatial and temporal variability of dynamical indicators over Thule and at the GOMOS tangent height position. Several corresponding features can be identified in the GOMOS and LIDAR profiles, suggesting that the GOMOS HRTP could be used to investigate the global distribution of small scale fluctuations. As an example, two cases corresponding to inner and outer vortex conditions during the 2008-2009 winter are discussed, also in relation with the very intense sudden stratospheric warming occurred in this season.

  13. X-ray scattering study of pike olfactory nerve: intensity of the axonal membrane, solution of the phase problem and electron density profile.

    Science.gov (United States)

    Luzzati, Vittorio; Vachette, Patrice; Benoit, Evelyne; Charpentier, Gilles

    2004-10-08

    Synchrotron radiation X-ray scattering experiments were performed on unmyelinated pike olfactory nerves. The difference between the meridional and the equatorial traces of the 2-D spectra yielded the 1-D equatorial intensity of the macromolecular components oriented with respect to the nerve: axonal membranes, microtubules and other cytoskeletal filaments. These 1-D spectra display a diffuse band typical of bilayer membranes and, at small s, a few sharper bands reminiscent of microtubules. All the spectra merge at large s. The intensity of the axonal membrane was determined via a noise analysis of the nerve-dependent spectra, involving also the notion that the thickness of the membrane is finite. The shape of the intensity function indicated that the electron density profile is not centrosymmetric. The knowledge of intensity and thickness paved the way to the electron density profile via an ab initio solution of the phase problem. An iterative procedure was adopted: (i) choose the lattice D of a 1-D pseudo crystal, interpolate the intensity at the points sh = h/D, adopt an arbitrary set of initial phases and compute the profile; (ii) determine the phases corresponding to this profile truncated by the thickness D/2; (iii) repeat the operation with the updated phases until a stable result is obtained. This iterative procedure was carried out for different D-values, starting in each case from randomly generated phases: stable results were obtained in less than 10,000 iterations. Most importantly, for D in the vicinity of 200 A, the overwhelming majority of the profiles were congruent with each other. These profiles were strongly asymmetric and otherwise typical of biological membranes.

  14. Determination of CT number and density profile of binderless, pre-treated and tannin-based Rhizophora spp. particleboards using computed tomography imaging and electron density phantom

    Energy Technology Data Exchange (ETDEWEB)

    Yusof, Mohd Fahmi Mohd, E-mail: mfahmi@usm.my; Hamid, Puteri Nor Khatijah Abdul; Tajuddin, Abdul Aziz [School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Bauk, Sabar [School of Distance Education, Universiti Sains Malaysia, 11800 Penang (Malaysia); Hashim, Rokiah [School of Industrial Technologies, Universiti Sains Malaysia, 11800 Penang (Malaysia)

    2015-04-29

    Plug density phantoms were constructed in accordance to CT density phantom model 062M CIRS using binderless, pre-treated and tannin-based Rhizophora Spp. particleboards. The Rhizophora Spp. plug phantoms were scanned along with the CT density phantom using Siemens Somatom Definition AS CT scanner at three CT energies of 80, 120 and 140 kVp. 15 slices of images with 1.0 mm thickness each were taken from the central axis of CT density phantom for CT number and CT density profile analysis. The values were compared to water substitute plug phantom from the CT density phantom. The tannin-based Rhizophora Spp. gave the nearest value of CT number to water substitute at 80 and 120 kVp CT energies with χ{sup 2} value of 0.011 and 0.014 respectively while the binderless Rhizphora Spp. gave the nearest CT number to water substitute at 140 kVp CT energy with χ{sup 2} value of 0.023. The tannin-based Rhizophora Spp. gave the nearest CT density profile to water substitute at all CT energies. This study indicated the suitability of Rhizophora Spp. particleboard as phantom material for the use in CT imaging studies.

  15. Theoretical studies on bioaerosol particle size and shape measurement from spatial scattering profiles

    Institute of Scientific and Technical Information of China (English)

    Chunxia Feng; Lihua Huang; Jianbo Wang; Yongkai Zhao; Huijie Huang

    2011-01-01

    @@ A method of clarifying bioaerosol particles is proposed based on T-matrix.Size and shape characterizations are simultaneously acquired for individual bioaerosol particles by analyzing the spatial distribution of scattered light.The particle size can be determined according to the scattering intensity,while shape information can be obtained through asymmetry factor(AF).The azimuthal distribution of the scattered light for spherical particles is symmetrical,whereas it is asymmetrical for non-spherical ones,and the asymmetry becomes intense with increasing asphericity.The calculated results denote that the 50-100 scattering angle is an effective range to classify the bioaerosol particles that we axe concerned of.The method is very useful in real-time environmental monitoring of particle sizes and shapes.%A method of clarifying bioaerosol particles is proposed based on T-matrix. Size and shape characterizations are simultaneously acquired for individual bioaerosol particles by analyzing the spatial distribution of scattered light. The particle size can be determined according to the scattering intensity, while shape information can be obtained through asymmetry factor (AF). The azimuthal distribution of the scattered light for spherical particles is symmetrical, whereas it is asymmetrical for non-spherical ones, and the asymmetry becomes intense with increasing asphericity. The calculated results denote that the 5°-10° scattering angle is an effective range to classify the bioaerosol particles that we are concerned of. The method is very useful in real-time environmental monitoring of particle sizes and shapes.

  16. NUMERICAL SOLUTION FOR THE POTENTIAL AND DENSITY PROFILE OF A THERMAL EQUILIBRIUM SHEET BEAM

    Energy Technology Data Exchange (ETDEWEB)

    Lund, S M; Bazouin, G

    2011-03-29

    In a recent paper, S. M. Lund, A. Friedman, and G. Bazouin, Sheet beam model for intense space-charge: with application to Debye screening and the distribution of particle oscillation frequencies in a thermal equilibrium beam, in press, Phys. Rev. Special Topics - Accel. and Beams (2011), a 1D sheet beam model was extensively analyzed. In this complementary paper, we present details of a numerical procedure developed to construct the self-consistent electrostatic potential and density profile of a thermal equilibrium sheet beam distribution. This procedure effectively circumvents pathologies which can prevent use of standard numerical integration techniques when space-charge intensity is high. The procedure employs transformations and is straightforward to implement with standard numerical methods and produces accurate solutions which can be applied to thermal equilibria with arbitrarily strong space-charge intensity up to the applied focusing limit.

  17. NUMERICAL SOLUTION FOR THE POTENTIAL AND DENSITY PROFILE OF A THERMAL EQUILIBRIUM SHEET BEAM

    Energy Technology Data Exchange (ETDEWEB)

    Bazouin, Steven M. Lund, Guillaume; Bazouin, Guillaume

    2011-04-01

    In a recent paper, S. M. Lund, A. Friedman, and G. Bazouin, Sheet beam model for intense space-charge: with application to Debye screening and the distribution of particle oscillation frequencies in a thermal equilibrium beam, in press, Phys. Rev. Special Topics - Accel. and Beams (2011), a 1D sheet beam model was extensively analyzed. In this complementary paper, we present details of a numerical procedure developed to construct the self-consistent electrostatic potential and density profile of a thermal equilibrium sheet beam distribution. This procedure effectively circumvents pathologies which can prevent use of standard numerical integration techniques when space-charge intensity is high. The procedure employs transformations and is straightforward to implement with standard numerical methods and produces accurate solutions which can be applied to thermal equilibria with arbitrarily strong space-charge intensity up to the applied focusing limit.

  18. Dynamics of electron injection and acceleration driven by laser wakefield in tailored density profiles

    Science.gov (United States)

    Lee, P.; Maynard, G.; Audet, T. L.; Cros, B.; Lehe, R.; Vay, J.-L.

    2016-11-01

    The dynamics of electron acceleration driven by laser wakefield is studied in detail using the particle-in-cell code WARP with the objective to generate high-quality electron bunches with narrow energy spread and small emittance, relevant for the electron injector of a multistage accelerator. Simulation results, using experimentally achievable parameters, show that electron bunches with an energy spread of ˜11 % can be obtained by using an ionization-induced injection mechanism in a mm-scale length plasma. By controlling the focusing of a moderate laser power and tailoring the longitudinal plasma density profile, the electron injection beginning and end positions can be adjusted, while the electron energy can be finely tuned in the last acceleration section.

  19. Evolution of density and velocity profiles of matter in large voids

    CERN Document Server

    Tsizh, Maksym

    2016-01-01

    We analyse the evolution of cosmological perturbations which leads to the formation of large voids in the distribution of galaxies. We assume that perturbations are spherical and all components of the Universe - radiation, matter and dark energy - are continuous media with ideal fluid energy-momentum tensors, which interact only gravitationally. Equations of the evolution of perturbations in the comoving to cosmological background reference frame for every component are obtained from equations of conservation and Einstein's ones and are integrated by modified Euler method. Initial conditions are set at the early stage of evolution in the radiation-dominated epoch, when the scale of perturbation is mush larger than the particle horizon. Results show how the profiles of density and velocity of matter in spherical voids with different overdensity shells are formed.

  20. Evolution of density and velocity profiles of matter in large voids

    Science.gov (United States)

    Tsizh, M.; Novosyadlyj, B.

    2016-09-01

    We analyse the evolution of cosmological perturbations which leads to the formation of large voids in the distribution of galaxies. We assume that perturbations are spherical and all components of the Universe - radiation, matter and dark energy - are continuous media with ideal fluid energy-momentum tensors, which interact only gravitationally. Equations of the evolution of perturbations in the comoving to cosmological background reference frame for every component are obtained from equations of conservation and Einstein's ones and are integrated by modified Euler method. Initial conditions are set at the early stage of evolution in the radiation-dominated epoch, when the scale of perturbation is mush larger than the particle horizon. Results show how the profiles of density and velocity of matter in spherical voids with different overdensity shells are formed.

  1. Size distribution and radial density profile of synaptic vesicles by SAXS and light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Castorph, Simon; Salditt, Tim [Institute for X-ray Physics, Goettingen (Germany); Holt, Matthew; Jahn, Reinhard [Max Plank Institute for Biophysical Chemistry, Goettingen (Germany); Sztucki, Michael [European Synchrotron Radiation Facility, Grenoble (France)

    2008-07-01

    Synaptic vesicles are small membraneous organelles within the nerve terminal, encapsulating neurotransmitters by a lipid bilayer. The transport of the neurotransmitter, the fusion at the plasma membrane, and the release of the stored neurotransmitters into the synaptic cleft are since long know as essential step in nerve conduction of the chemical synapse. A detailed structural view of these molecular mechanisms is still lacking, not withstanding the enormous progress in the field during recent years. From measurements and quantitative fitting of small angle X-ray scattering curves and dynamic light scattering the averaged structural properties of synaptic vesicles can be determined. We present SAXS measurements and fits revealing the width of the size distribution function and details of the radial scattering length profile of synaptic vesicles from rat brain. Representative values for the inner and outer radius and the size polydispersity as well as the density and width of the outer protein layer are obtained.

  2. Asymmetric Velocity Distributions from Halo Density Profiles in the Eddington Approach

    Directory of Open Access Journals (Sweden)

    J. D. Vergados

    2015-01-01

    Full Text Available We show how to obtain the energy distribution f(E in our vicinity starting from WIMP density profiles in a self-consistent way by employing the Eddington approach and adding reasonable angular momentum dependent terms in the expression of the energy. We then show how we can obtain the velocity dispersions and the asymmetry parameter β in terms of the parameters describing the angular momentum dependence. From this expression, for f(E, we proceed to construct an axially symmetric WIMP a velocity distribution, which, for a gravitationally bound system, automatically has a velocity upper bound and is characterized by the same asymmetriy β. This approach is tested and clarified by constructing analytic expressions in a simple model, with adequate structure. We then show how such velocity distributions can be used in determining the event rates, including modulation, in both the standard and the directional WIMP searches.

  3. New density profile and structural parameters of the complex stellar system Terzan 5

    CERN Document Server

    Lanzoni, B; Dalessandro, E; Mucciarelli, A; Beccari, G; Miocchi, P; Bellazzini, M; Rich, R M; Origlia, L; Valenti, E; Rood, R T; Ransom, S

    2010-01-01

    Terzan 5 is a globular cluster-like stellar system in the Galactic Bulge which has been recently found to harbor two stellar populations with different iron content and probably different ages (Ferraro et al. 2009). This discovery suggests that Terzan 5 may be the relic of a primordial building block which contributed to the formation of the Galactic Bulge. Here we present a re-determination of the structural parameters (center of gravity, density and surface brightness profiles, total luminosity and mass) of Terzan 5, as obtained from the combination of high-resolution (ESO-MAD and HST ACS-WFC) and wide-field (ESO-WFI) observations. We find that Terzan 5 is significantly less concentrated and more massive than previously thought. Still it has the largest collision rate of any stellar aggregate in the Galaxy. We discuss the impact of these findings on the exceptional population of millisecond pulsars harbored in this stellar system.

  4. Effect of Control Blade History, and Axial Coolant Density and Burnup Profiles on BWR Burnup Credit

    Energy Technology Data Exchange (ETDEWEB)

    Ade, Brian J [ORNL; Marshall, William BJ J [ORNL; Martinez-Gonzalez, Jesus S [ORNL

    2015-05-01

    Oak Ridge National Laboratory (ORNL) and the US Nuclear Regulatory Commission (NRC) have initiated a multiyear project to investigate the application of burnup credit (BUC) for boiling water reactor (BWR) fuel in storage and transportation systems (often referred to as casks) and spent fuel pools (SFPs). This work is divided into two main phases. The first phase investigated the applicability of peak reactivity methods currently used in SFPs to transportation and storage casks and the validation of reactivity calculations and spent fuel compositions within these methods. The second phase focuses on extending BUC beyond peak reactivity. This paper documents the analysis of the effects of control blade insertion history, and moderator density and burnup axial profiles for extended BWR BUC.

  5. Whittaker functions in beam driven plasma wakefield acceleration for a plasma with a parabolic density profile

    Energy Technology Data Exchange (ETDEWEB)

    Golian, Y.; Dorranian, D., E-mail: d.dorranian@gmail.com [Laser Laboratory, Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Aslaninejad, M., E-mail: m.aslaninejad@ipm.ir [Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2016-01-15

    A model for the interaction of charged particle beams and plasma for a linear wakefield generation in a parabolic plasma channel is presented. The density profile has the maximum on the axis. A Gaussian proton beam is employed to excite the plasma wakefield in the channel. We have built a thorough analytical model and solved the governing equations for the wakefield acceleration of a charged particle beam. The longitudinal and radial wakefields are expressed by Whittaker functions, and for certain parameters of plasma and the beam, their behaviours in longitudinal and radial directions are investigated. It is observed that the radial electric field generated by the bunch increases with the distance behind the bunch.

  6. Whittaker functions in beam driven plasma wakefield acceleration for a plasma with a parabolic density profile

    Science.gov (United States)

    Golian, Y.; Aslaninejad, M.; Dorranian, D.

    2016-01-01

    A model for the interaction of charged particle beams and plasma for a linear wakefield generation in a parabolic plasma channel is presented. The density profile has the maximum on the axis. A Gaussian proton beam is employed to excite the plasma wakefield in the channel. We have built a thorough analytical model and solved the governing equations for the wakefield acceleration of a charged particle beam. The longitudinal and radial wakefields are expressed by Whittaker functions, and for certain parameters of plasma and the beam, their behaviours in longitudinal and radial directions are investigated. It is observed that the radial electric field generated by the bunch increases with the distance behind the bunch.

  7. The global shape, density and rotation of Comet 67P/Churyumov-Gerasimenko from preperihelion Rosetta/OSIRIS observations

    Science.gov (United States)

    Jorda, L.; Gaskell, R.; Capanna, C.; Hviid, S.; Lamy, P.; Ďurech, J.; Faury, G.; Groussin, O.; Gutiérrez, P.; Jackman, C.; Keihm, S. J.; Keller, H. U.; Knollenberg, J.; Kührt, E.; Marchi, S.; Mottola, S.; Palmer, E.; Schloerb, F. P.; Sierks, H.; Vincent, J.-B.; A'Hearn, M. F.; Barbieri, C.; Rodrigo, R.; Koschny, D.; Rickman, H.; Barucci, M. A.; Bertaux, J. L.; Bertini, I.; Cremonese, G.; Da Deppo, V.; Davidsson, B.; Debei, S.; De Cecco, M.; Fornasier, S.; Fulle, M.; Güttler, C.; Ip, W.-H.; Kramm, J. R.; Küppers, M.; Lara, L. M.; Lazzarin, M.; Lopez Moreno, J. J.; Marzari, F.; Naletto, G.; Oklay, N.; Thomas, N.; Tubiana, C.; Wenzel, K.-P.

    2016-10-01

    The Rosetta spacecraft reached Comet 67P/Churyumov-Gerasimenko (hereafter 67P/C-G) in August 2014 at an heliocentric distance of 3.6 a.u. and was then put in orbit around its nucleus to perform detailed observations. Among the collected data are the images acquired by the OSIRIS instrument up to the perihelion passage of the comet in August 2015, which allowed us to map the entire nucleus surface at high-resolution in the visible. Stereophotoclinometry methods have been used to reconstruct a global high-resolution shape model and to monitor its rotational parameters using data collected up to perihelion. The nucleus has a conspicuous bilobate shape with overall dimensions along its principal axes of (4.34 ± 0.02) × (2.60 ± 0.02) × (2.12 ± 0.06) km. The best-fit ellipsoid dimensions of the individual lobes along their principal axes of inertia are found to be 4.10 × 3.52 × 1.63 km and 2.50 × 2.14 × 1.64 km. Their volume amounts to 66% and 27% of the total volume of the nucleus. The two lobes are connected by a "neck" whose volume has been estimated to represent ∼7% of the total volume of the comet. Combining the derived volume of 18.8 ± 0.3 km3 with the mass of 9.982 ± 0.003 × 1012 kg determined by the Rosetta/RSI experiment, we obtained a bulk density of the nucleus of 532 ± 7 kg m-3 . Together with the companion value of 535 ± 35 kg m-3 deduced from the stereophotogrammetry shape model of the nucleus (Preusker et al. [2015] Astron. Astrophys. 583, A33), these constitute the first reliable and most accurate determination of the density of a cometary nucleus to date. The calculated porosity is quite large, ranging approximately from 70% to 75% depending upon the assumed density of the dust grains and the dust-to-ice mass ratio. The nature of the porosity, either micro or macro or both, remains unconstrained. The coordinates of the center of gravity are not compatible with a uniform nucleus density. The direction of the offset between the center of

  8. Predation Risk Perception, Food Density and Conspecific Cues Shape Foraging Decisions in a Tropical Lizard.

    Directory of Open Access Journals (Sweden)

    Maximilian Drakeley

    Full Text Available When foraging, animals can maximize their fitness if they are able to tailor their foraging decisions to current environmental conditions. When making foraging decisions, individuals need to assess the benefits of foraging while accounting for the potential risks of being captured by a predator. However, whether and how different factors interact to shape these decisions is not yet well understood, especially in individual foragers. Here we present a standardized set of manipulative field experiments in the form of foraging assays in the tropical lizard Anolis cristatellus in Puerto Rico. We presented male lizards with foraging opportunities to test how the presence of conspecifics, predation-risk perception, the abundance of food, and interactions among these factors determines the outcome of foraging decisions. In Experiment 1, anoles foraged faster when food was scarce and other conspecifics were present near the feeding tray, while they took longer to feed when food was abundant and when no conspecifics were present. These results suggest that foraging decisions in anoles are the result of a complex process in which individuals assess predation risk by using information from conspecific individuals while taking into account food abundance. In Experiment 2, a simulated increase in predation risk (i.e., distance to the feeding tray confirmed the relevance of risk perception by showing that the use of available perches is strongly correlated with the latency to feed. We found Puerto Rican crested anoles integrate instantaneous ecological information about food abundance, conspecific activity and predation risk, and adjust their foraging behavior accordingly.

  9. Predation Risk Perception, Food Density and Conspecific Cues Shape Foraging Decisions in a Tropical Lizard.

    Science.gov (United States)

    Drakeley, Maximilian; Lapiedra, Oriol; Kolbe, Jason J

    2015-01-01

    When foraging, animals can maximize their fitness if they are able to tailor their foraging decisions to current environmental conditions. When making foraging decisions, individuals need to assess the benefits of foraging while accounting for the potential risks of being captured by a predator. However, whether and how different factors interact to shape these decisions is not yet well understood, especially in individual foragers. Here we present a standardized set of manipulative field experiments in the form of foraging assays in the tropical lizard Anolis cristatellus in Puerto Rico. We presented male lizards with foraging opportunities to test how the presence of conspecifics, predation-risk perception, the abundance of food, and interactions among these factors determines the outcome of foraging decisions. In Experiment 1, anoles foraged faster when food was scarce and other conspecifics were present near the feeding tray, while they took longer to feed when food was abundant and when no conspecifics were present. These results suggest that foraging decisions in anoles are the result of a complex process in which individuals assess predation risk by using information from conspecific individuals while taking into account food abundance. In Experiment 2, a simulated increase in predation risk (i.e., distance to the feeding tray) confirmed the relevance of risk perception by showing that the use of available perches is strongly correlated with the latency to feed. We found Puerto Rican crested anoles integrate instantaneous ecological information about food abundance, conspecific activity and predation risk, and adjust their foraging behavior accordingly.

  10. Design Method for a Low-Profile Dual-Shaped Reflector Antenna with an Elliptical Aperture by the Suppression of Undesired Scattering

    Science.gov (United States)

    Inasawa, Yoshio; Kuroda, Shinji; Kusakabe, Kenji; Naito, Izuru; Konishi, Yoshihiko; Makino, Shigeru; Tsuchiya, Makio

    A design method is proposed for a low-profile dual-shaped reflector antenna for the mobile satellite communications. The antenna is required to be low-profile because of mount restrictions. However, reduction of its height generally causes degradation of antenna performance. Firstly, an initial low-profile reflector antenna with an elliptical aperture is designed by using Geometrical Optics (GO) shaping. Then a Physical Optics (PO) shaping technique is applied to optimize the gain and sidelobes including mitigation of undesired scattering. The developed design method provides highly accurate design procedure for electrically small reflector antennas. Fabrication and measurement of a prototype antenna support the theory.

  11. Tidal Disruption of Milky Way Satellites with Shallow Dark Matter Density Profiles

    Directory of Open Access Journals (Sweden)

    Ewa L. Łokas

    2016-11-01

    Full Text Available Dwarf galaxies of the Local Group provide unique possibilities to test current theories of structure formation. Their number and properties have put the broadly accepted cold dark matter model into question, posing a few problems. These problems now seem close to resolution due to the improved treatment of baryonic processes in dwarf galaxy simulations which now predict cored rather than cuspy dark matter profiles in isolated dwarfs with important consequences for their subsequent environmental evolution. Using N-body simulations, we study the evolution of a disky dwarf galaxy with such a shallow dark matter profile on a typical orbit around the Milky Way. The dwarf survives the first pericenter passage but is disrupted after the second due to tidal forces from the host. We discuss the evolution of the dwarf’s properties in time prior to and at the time of disruption. We demonstrate that the dissolution occurs on a rather short timescale as the dwarf expands from a spheroid into a stream with non-zero mean radial velocity. We point out that the properties of the dwarf at the time of disruption may be difficult to distinguish from bound configurations, such as tidally induced bars, both in terms of surface density and line-of-sight kinematics.

  12. Modelling the stellar soft-photon energy density profile of globular clusters

    CERN Document Server

    Prinsloo, P L; Buesching, I; Kopp, A

    2013-01-01

    Recent observations by e.g. Fermi Large Area Telescope (LAT) and the High Energy Stereoscopic System (H.E.S.S.) have revealed globular clusters (GC) to be sources of high-energy (HE) and very-high-energy (VHE) gamma rays. It has been suggested that the presence of large numbers of millisecond pulsars (MSPs) within these clusters may be either directly responsible for these gamma-ray fluxes through emission of pulsed curvature radiation, or indirectly through the injection of relativistic leptons into the cluster. These relativistic particles are plausibly re-accelerated in shocks, created by the collision of stellar winds, before interacting with the soft-photon radiation field set up by the stellar population of the host cluster. Inverse Compton (IC) scattering then produces gamma radiation in the TeV band. In order to calculate the IC spectrum, an accurate profile for the energy density of the soft-photon field is required. We construct such a profile by deriving a radially-dependent expression for the stel...

  13. Evolution of density and velocity profiles of dark matter and dark energy in spherical voids

    Science.gov (United States)

    Novosyadlyj, Bohdan; Tsizh, Maksym; Kulinich, Yurij

    2017-02-01

    We analyse the evolution of cosmological perturbations which leads to the formation of large isolated voids in the Universe. We assume that initial perturbations are spherical and all components of the Universe (radiation, matter and dark energy) are continuous media with ideal fluid energy-momentum tensors, which interact only gravitationally. Equations of the evolution of perturbations for every component in the comoving to cosmological background reference frame are obtained from equations of energy and momentum conservation and Einstein's ones and are integrated numerically. Initial conditions are set at the early stage of evolution in the radiation-dominated epoch, when the scale of perturbation is much larger than the particle horizon. Results show how the profiles of density and velocity of matter and dark energy are formed and how they depend on parameters of dark energy and initial conditions. In particular, it is shown that final matter density and velocity amplitudes change within range ˜4-7 per cent when the value of equation-of-state parameter of dark energy w vary in the range from -0.8 to -1.2, and change within ˜1 per cent only when the value of effective sound speed of dark energy vary over all allowable range of its values.

  14. Influence of particles shape on the vertical profile of blowing snow concentration

    Science.gov (United States)

    Vionnet, Vincent; Trouvilliez, Alexandre; Naaim-Bouvet, Florence; Guyomarc'h, Gilbert

    2013-04-01

    In alpine regions, blowing snow events strongly influence the temporal and spatial evolution of the snow cover throughout the winter season. In Antarctica, blowing snow is an essential surface mass balance process and plays a non-negligible role in the annual accumulation. The vertical profile of blowing snow concentration determines the quantity of snow transported in turbulent suspension. A power law is often used to represent this vertical profile. It serves as an analytical solution representing an equilibrium between vertical turbulent diffusion and gravitational settling. In this work, we study how the exponent of the power law depends on the type of transported particles. Vertical profiles of blowing snow concentration have been collected at the experimental site of Col du Lac Blanc (French Alps) in 2011 and 2012 and near the research station of Cap Prud'homme (Antarctica) in 2010 and 2011. We used mechanical gauges (butterfly nets) and optical devices (Snow Particles Counters). Profiles collected during blowing snow events with precipitation have been corrected to account for the contribution of snowfall. Results show that profiles collected during blowing snow without snowfall differ from the corrected profiles collected during snowfall. At a given wind speed, particles transported during snowfall have a lower settling velocity than particles transported without snowfall. This difference confirms earlier observations (Takahashi, 1985) and can be explained by the change of drag coefficient between dendritic and rounded particles. This difference pertains several hours after the end of the snowfall illustrating the fragmentation of snow grains during blowing snow events.

  15. Dynamical density functional theory for arbitrary-shape colloidal fluids including inertia and hydrodynamic interactions

    Science.gov (United States)

    Duran-Olivencia, Miguel A.; Goddard, Ben; Kalliadasis, Serafim

    2015-11-01

    Over the last few decades the classical density-functional theory (DFT) and its dynamic extensions (DDFTs) have become a remarkably powerful tool in the study of colloidal fluids. Recently there has been extensive research to generalise all previous DDFTs finally yielding a general DDFT equation (for spherical particles) which takes into account both inertia and hydrodynamic interactions (HI) which strongly influence non-equilibrium properties. The present work will be devoted to a further generalisation of such a framework to systems of anisotropic particles. To this end, the kinetic equation for the Brownian particle distribution function is derived starting from the Liouville equation and making use of Zwanzig's projection-operator techniques. By averaging over all but one particle, a DDFT equation is finally obtained with some similarities to that for spherical colloids. However, there is now an inevitable translational-rotational coupling which affects the diffusivity of asymmetric particles. Lastly, in the overdamped (high friction) limit the theory is notably simplified leading to a DDFT equation which agrees with previous derivations. We acknowledge financial support from European Research Council via Advanced Grant No. 247031.

  16. Influence of the fluid structure on the binding potential: Comparing liquid drop profiles from density functional theory with results from mesoscopic theory

    Science.gov (United States)

    Hughes, Adam P.; Thiele, Uwe; Archer, Andrew J.

    2017-02-01

    For a film of liquid on a solid surface, the binding potential g(h) gives the free energy as a function of the film thickness h and also the closely related (structural) disjoining pressure Π =-∂g /∂h . The wetting behaviour of the liquid is encoded in the binding potential and the equilibrium film thickness corresponds to the value at the minimum of g(h). Here, the method we developed in the work of Hughes et al. [J. Chem. Phys. 142, 074702 (2015)], and applied with a simple discrete lattice-gas model, is used with continuum density functional theory (DFT) to calculate the binding potential for a Lennard-Jones fluid and other simple liquids. The DFT used is based on fundamental measure theory and so incorporates the influence of the layered packing of molecules at the surface and the corresponding oscillatory density profile. The binding potential is frequently input in mesoscale models from which liquid drop shapes and even dynamics can be calculated. Here we show that the equilibrium droplet profiles calculated using the mesoscale theory are in good agreement with the profiles calculated directly from the microscopic DFT. For liquids composed of particles where the range of the attraction is much less than the diameter of the particles, we find that at low temperatures g(h) decays in an oscillatory fashion with increasing h, leading to highly structured terraced liquid droplets.

  17. On the shape of the magnetic Barkhausen noise profile for better revelation of the effect of microstructures on the magnetisation process in ferritic steels

    Energy Technology Data Exchange (ETDEWEB)

    Vashista, M., E-mail: mvashista.mec@iitbhu.ac.in [Design Unit, School of Mechanical and Systems Engineering, Newcastle University (United Kingdom); Department of Mechanical Engineering, Indian Institute of Technology, BHU, Varanasi (India); Moorthy, V., E-mail: v.moorthy@ncl.ac.uk [Design Unit, School of Mechanical and Systems Engineering, Newcastle University (United Kingdom)

    2015-11-01

    The shape of the Magnetic Barkhausen Noise (MBN) profiles has been compared for two different methods of MBN measurements in order to reveal the true extent of the influence of different carbon-content related microstructures on the magnetisation process. The MBN profiles were measured using high frequency and low frequency MBN measurement systems on samples from low carbon 18CrNiMo5 steel and high carbon 42CrMo4 steel heat treated by isothermal annealing, spheroidising annealing and quenching and tempering processes. The high frequency MBN (HFMBN) profile shows only a single peak for all the samples due to insufficient applied magnetic field strength and shallow skin-depth of detection of HFMBN signals. The low frequency MBN (LFMBN) profile shows two peaks for all the samples due to larger magnetisation range revealing the difference in the interaction of domain walls with different microstructural features such as ferrite, pearlite, martensite and carbides. The shape of the LFMBN profile shows systematic and distinct variation in the magnetisation process with respect to carbon content and different microstructures. This study shows that the LFMBN profile reveals distinct changes in shape which could be successfully used for characterisation of different microstructural phases in ferritic steels. - Highlights: • Shape of the Magnetic Barkhausen Noise Profile reveals the variation in magnetisation process. • Optimising the magnetic barkhausen noise profile for better evaluation of microstructures. • Effect of measurement parameters on the shape of the magnetic barkhausen noise profile. • Comparison of high frequency and low frequency magnetic barkhausen noise profiles. • More detailed microstructural information from the shape of the magnetic barkhausen noise profile.

  18. Optimal Density Profile of the Plasma Layer Shielded by a Conducting Surface for the Absorption of Electromagnetic Waves

    Institute of Scientific and Technical Information of China (English)

    王舸; 曹金祥; 宋法伦

    2003-01-01

    Based on the Born approximation, we reduce the approximate analysis solution to the normal and oblique incident electromagnetic wave scattering from the weakly ionized plasma layer shielded by a conducting surface. The solution is closely related to the density profile of the plasma layer. Employing the self-consistent base function, we yield the optimal density profile for the nonuniform plasma layer with the frequencies of incident electromagnetic waves ranging from 4-10 GHz. Numerical studies illustrate the optimal density profile can "survive" wide ranges of the plasma parameters. Different from the validity condition for the Wenzell-Kramers-Brillouin-Jeffreys (WKBJ) approximation, the Born approximation is feasible even if the scale length is smaller than the wavelength.Therefore, the Born approximation is universal against the scattering problem from the weakly ionized plasma.

  19. Comparison of high latitude electron density profiles obtained with the GPS radio occultation technique and EISCAT measurements

    Directory of Open Access Journals (Sweden)

    C. Stolle

    2004-06-01

    Full Text Available To obtain a comprehensive view on high latitude processes by applying different observation techniques, the SIRCUS campaign was initiated in 2001/2002. This paper compares electron density profiles derived from CHAMP radio occultation data and those measured with the EISCAT facility. Since ionospheric profiling with the help of space-based received GPS is a relatively new technique, validations with established independent instruments are of crucial need. We present 28 profiling events for quasi-statistical analyses, which occurred during the SIRCUS campaigns and describe some of them in more detail. We found out that the majority of profile comparisons in electron density peak value and height, as well as in TEC, lie within the error ranges of the two methods. Differences in the ionospheric quantities do not necessarily occur when the locations of the occultation and of the radar site show considerable distances. Differences are more pronounced when the ionosphere is remarkably structured.

  20. Investigation of the spring-in of a pultruded L-shaped profile for various processing conditions and thicknesses

    DEFF Research Database (Denmark)

    Baran, Ismet; Hattel, Jesper Henri; Akkerman, Remko

    2014-01-01

    In this study, a thermo-mechanical finite element model is developed to predict the spring- in of an industrially pultruded L-shaped profile made of glass/polyester composite. The resin curing kinetics are obtained from the differential scanning calorimetry (DSC) experiments. The development...... of the resin modulus is derived using the dynamic mechanical analysis (DMA) tests and the effective mechanical properties of the processing composite are calculated using a micromechanical model. The temperature and degree of cure distributions are obtained in a three dimensional (3D) thermo-chemical anlaysis...

  1. Understanding the overall shape of the output characteristics from the change in the channel potential profile for nanowire FET

    Science.gov (United States)

    Sarkar, Niladri

    2017-01-01

    We have shown the influence of the changing channel potential profile from its equilibrium profile on the overall shape of the output characteristics of a Nanowire FET which is operating under ballistic regime. The device has a nano-wire channel with an array of lattice points which is the surrounded by a coaxial metallic gate. There is a dielectric which isolates the channel from the metallic gate. The source and the drain electrodes are maintained at different chemical potentials μ1 and μ2 which gives rise to the channel current in the device. The physics and the modeling of this device have been understood in detail by studying the electrostatics of the channel.

  2. AIDEN: A Density Conscious Artificial Immune System for Automatic Discovery of Arbitrary Shape Clusters in Spatial Patterns

    Directory of Open Access Journals (Sweden)

    Vishwambhar Pathak

    2012-11-01

    Full Text Available Recent efforts in modeling of dynamics of the natural immune cells leading to artificial immune systems (AIS have ignited contemporary research interest in finding out its analogies to real world problems. The AIS models have been vastly exploited to develop dependable robust
    solutions to clustering. Most of the traditional clustering methods bear limitations in their capability to detect clusters of arbitrary shapes in a fully unsupervised manner. In this paper the recognition and communication dynamics of T Cell Receptors, the recognizing elements in innate immune
    system, has been modeled with a kernel density estimation method. The model has been shown to successfully discover non spherical clusters in spatial patterns. Modeling the cohesion of the antibodies and pathogens with ‘local influence’ measure inducts comprehensive extension of the
    antibody representation ball (ARB, which in turn corresponds to controlled expansion of clusters and prevents overfitting.

  3. Ordinary mode reflectometry. Modification of the scattering and cut-off responses due to the shape of localized density fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Fanack, C.; Boucher, I.; Heuraux, S.; Leclert, G. [Centre National de la Recherche Scientifique (CNRS), 54 - Nancy (France). Lab. de Physique du Solide; Clairet, F.; Zou, X.L. [Association Euratom-CEA, Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    1996-01-01

    Ordinary wave reflectometry in a plasma containing a localized density perturbation is studied with a 1-D model. The phase response is studied as a function of the wavenumber and position of the perturbation. It is shown that it strongly depends upon the perturbation shape and size. For a small perturbation wavenumber, the response is due to the oscillation of the cut-off layer. For larger wavenumbers, two regimes are found: for a broad perturbation, the phase response is an image of the perturbation itself; for a narrow perturbation, it is rather an image of the Fourier transform. For tokamak plasmas it turns out that, for the fluctuation spectra usually observed, the phase response comes primarily from those fluctuations that are localized at the cut-off. Results of a 2-D numerical model show that geometry effects are negligible for the scattering by radial fluctuations. (author). 18 refs.

  4. Relationship between habitat, densities and metabolic profile in brown hares (Lepus europaeus Pallas

    Directory of Open Access Journals (Sweden)

    Marco Bagliacca

    2010-01-01

    Full Text Available Some habitat traits and haematic parameters were studied to understand the relationships between the hare densities, habitat characteristics and physiological and nutritional condition of the animals. A total of 33 protected areas, reserved for wild game reproduction, located in the Province of Florence (Central Italy, were monitored during a 2-year period. In each protected area the hares were submitted to census. The habitat features of the protected areas were studied and the following parameters were categorised: altitude; cleared-land/total-land ratio; main exposure; main ground composition; water availability; main slope; anthropogenic presence; predator presence; wooded borders; presence of trees and shrubs; surveillance against hunting; demographic predator control; kind of cultivation; unharvested crops for game. After the census the hares were captured for translocation outside in “free” hunting areas. During capture the hares were put in darkened, wooden capture-boxes and remained inside for a variable period of time (10min to 3h. A sample of 3 to 7 hares, captured per year and per each protected area, were removed from the boxes (physically restrained, with covered eyes for blood sample collection, sex, age and live weight determination. The following analyses were performed on frozen plasma samples: ALanine aminoTransferase (ALT, ASpartate aminoTransferase (AST, glucose, cholesterol, Blood Urea Nitrogen (BUN, Ca, P, Mg, Na, K, and Cl concentrations. The relationship between hare density and habitat characteristics was analysed by single regressions analysis. Then the habitat characteristics were subjected to multivariate analysis in relationship to hare body condition. The haematic parameters were analysed by least square means considering habitat traits, animal density, age and sex, as main categorical factors, interaction sex*age, and “pregnant and non-reproducing” nested within sex. Results showed that the highest density

  5. NIHAO project II: Halo shape, phase-space density and velocity distribution of dark matter in galaxy formation simulations

    CERN Document Server

    Butsky, Iryna; Dutton, Aaron A; Wang, Liang; Stinson, Greg S; Penzo, Camilla; Kang, Xi; Keller, Ben W; Wadsley, James

    2015-01-01

    We show the effect of galaxy formation on the dark matter (DM) distribution across a wide range of halo masses. We focus on how baryon physics changes the dark matter halo shape, the so called "pseudo phase-space density distribution" and the velocity distribution within the virial radius, Rvir and in the solar neighborhood. This study is based on the NIHAO galaxy formation simulations, a large suite of cosmological zoom-in simulations. The galaxies reproduce key properties of observed galaxies, and hence offer unique insight into how baryons change the dark matter morphology and kinematics. When compared to dark matter only simulations, the NIHAO haloes have similar shapes at Rvir, but are substantially rounder inside ~0.1 Rvir. In DM-only simulations the inner halo has a minor-to-major axis ratio of c/a~0.5. In hydro simulations c/a increases with halo mass and integrated star formation efficiency, reaching ~0.8 at the Milky Way mass, reconciling a long-standing conflict between observations and DM only sim...

  6. Direct evaluation of the position dependent diffusion coefficient and persistence time from the equilibrium density profile in anisotropic fluids.

    Science.gov (United States)

    Olivares-Rivas, Wilmer; Colmenares, Pedro J; López, Floralba

    2013-08-21

    We derive expressions for the transverse diffusion coefficient D(z) and the average persistence time τ(z; L) within a layer of width L, for particles of a non-homogeneous fluid enclosed in a planar nanopore. The method allows the direct evaluation of these position-dependent dynamical quantities from the equilibrium local particle density profile. We use results for the density and persistence time profiles from the virtual layer molecular dynamics method to numerically assess the significance of the Smoluchowski approximation.

  7. Analysis of plasma equilibrium based on orbit-driven current density profile in steady-state plasma on QUEST

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, K., E-mail: nakamura@triam.kyushu-u.ac.jp [RIAM, Kyushu University, Kasuga 816-8580 (Japan); Alam, M.M. [IGSES, Kyushu University, Kasuga 816-8580 (Japan); Jiang, Y.Z. [Tsinghua University, Beijing 100084 (China); Mitarai, O. [Tokai University, Kumamoto 862-8652 (Japan); Kurihara, K.; Kawamata, Y.; Sueoka, M.; Takechi, M. [Japan Atomic Energy Agency, Naka 311-0193 (Japan); Hasegawa, M.; Tokunaga, K.; Araki, K.; Zushi, H.; Hanada, K.; Fujisawa, A.; Idei, H.; Nagashima, Y.; Kawasaki, S.; Nakashima, H.; Higashijima, A.; Nagata, T. [RIAM, Kyushu University, Kasuga 816-8580 (Japan); and others

    2016-11-01

    Highlights: • High energy particle guiding center orbit is calculated as a contour plot of conserved variable. • Current density profile is analyzed based on the orbit-driven current. • Plasma equilibrium is reconstructed by considering the hollow current profile. - Abstract: In the present RF-driven (ECCD) steady-state plasma on QUEST (B{sub t} = 0.25 T, R = 0.68 m, a = 0.40 m), plasma current seems to flow in the open magnetic surface outside of the closed magnetic surface in the low-field region according to plasma current fitting (PCF) method. We consider that the current in the open magnetic surface is due to orbit-driven current by high-energy particles in RF-driven plasma. So based on the analysis of current density profile based on the orbit-driven current, plasma equilibrium is to be calculated. We calculated high energy particles guiding center orbits as a contour plot of conserved variable in Hamiltonian formulation and considered particles initial position with different levels of energy and pitch angles that satisfy resonance condition. Then the profile of orbit-driven current is estimated by multiplying the particle density on the resonance surface and the velocity on the orbits. This analysis shows negative current near the magnetic axis and hollow current profile is expected even if pressure driven current is considered. Considering the hollow current profile shifted toward the low-field region, the equilibrium is fitted by J-EFIT coded by MATLAB.

  8. Method to obtain absolute impurity density profiles combining charge exchange and beam emission spectroscopy without absolute intensity calibrationa)

    Science.gov (United States)

    Kappatou, A.; Jaspers, R. J. E.; Delabie, E.; Marchuk, O.; Biel, W.; Jakobs, M. A.

    2012-10-01

    Investigation of impurity transport properties in tokamak plasmas is essential and a diagnostic that can provide information on the impurity content is required. Combining charge exchange recombination spectroscopy (CXRS) and beam emission spectroscopy (BES), absolute radial profiles of impurity densities can be obtained from the CXRS and BES intensities, electron density and CXRS and BES emission rates, without requiring any absolute calibration of the spectra. The technique is demonstrated here with absolute impurity density radial profiles obtained in TEXTOR plasmas, using a high efficiency charge exchange spectrometer with high etendue, that measures the CXRS and BES spectra along the same lines-of-sight, offering an additional advantage for the determination of absolute impurity densities.

  9. Method to obtain absolute impurity density profiles combining charge exchange and beam emission spectroscopy without absolute intensity calibration

    Energy Technology Data Exchange (ETDEWEB)

    Kappatou, A.; Delabie, E. [FOM Institute DIFFER - Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM, 3430 BE Nieuwegein (Netherlands); Jaspers, R. J. E.; Jakobs, M. A. [Science and Technology of Nuclear Fusion, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Marchuk, O.; Biel, W. [Institute for Energy and Climate Research, Forschungszentrum Julich GmbH, Trilateral Euregio Cluster, 52425 Julich (Germany)

    2012-10-15

    Investigation of impurity transport properties in tokamak plasmas is essential and a diagnostic that can provide information on the impurity content is required. Combining charge exchange recombination spectroscopy (CXRS) and beam emission spectroscopy (BES), absolute radial profiles of impurity densities can be obtained from the CXRS and BES intensities, electron density and CXRS and BES emission rates, without requiring any absolute calibration of the spectra. The technique is demonstrated here with absolute impurity density radial profiles obtained in TEXTOR plasmas, using a high efficiency charge exchange spectrometer with high etendue, that measures the CXRS and BES spectra along the same lines-of-sight, offering an additional advantage for the determination of absolute impurity densities.

  10. Spatial profiles of interelectrode electron density in direct current superposed dual-frequency capacitively coupled plasmas

    Science.gov (United States)

    Ohya, Yoshinobu; Ishikawa, Kenji; Komuro, Tatsuya; Yamaguchi, Tsuyoshi; Takeda, Keigo; Kondo, Hiroki; Sekine, Makoto; Hori, Masaru

    2017-04-01

    We present experimentally determined spatial profiles of the interelectrode electron density (n e) in dual-frequency capacitively coupled plasmas in which the negative direct current (dc) bias voltage (V dc) is superposed; in the experiment, 13 MHz (P low) was applied to the lower electrode and 60 MHz (P high) to the upper electrode. The bulk n e increased substantially with increases in the external power, P high, P low, and with increases in V dc. When P low was insufficient, the bulk n e decreased as the V dc bias increased. The bulk n e increased due to its dependence on V dc, especially for |V dc|  >  500 V. This may correspond to the sheath voltages (V s) of the lower electrode. The n e values in front of the upper electrode were coupled with the V dc: the V dc dependence first decreased and then increased. The dc currents (I dc) of the upper electrode were collected when a large P low was applied. The value of I dc at the threshold value of V dc  ≈  V s (e.g.  ‑500 V) increased with an increase in n e. When |V dc| exceeded the threshold, the spatial n e profile and the I dc dependence were changed relative to the electrical characteristics of the dc superposition; this led to a change in the location of the maximum n e, the width of the area of n e depletion in front of the electrodes, and a transition in the electron heating modes.

  11. An Estimate of Solar Wind Density and Velocity Profiles in a Coronal Hole and a Coronal Streamer

    Science.gov (United States)

    Patzold, M.; Tsurutani, B. T.; Bird, M. K.

    1996-01-01

    Using the total electron content data obtained by the Ulysses Solar Corona Experiment (SCE) during the first solar conjunction in summer 1991, two data sets were selected, one associated with a coronal hole and the other associated with coronal streamer crossings. In order to determine coronal streamer density profiles, the electron content of the tracking passes embedded in a coronal streamer were corrected for the contributions from coronal hole densities.

  12. Peaked density profiles in neon and lithium doped discharges on FTU

    Energy Technology Data Exchange (ETDEWEB)

    Mazzotta, C., E-mail: cristina.mazzotta@enea.it [Associazione Euratom-ENEA sulla Fusione, Via E. Fermi 45, 00044 Frascati (Italy); Apicella, M.L.; Botrugno, A.; Gabellieri, L.; Marinucci, M.; Mazzitelli, G.; Pucella, G. [Associazione Euratom-ENEA sulla Fusione, Via E. Fermi 45, 00044 Frascati (Italy); Sozzi, C. [Istituto di Fisica dei Plasmi, CNR, Via R. Cozzi 53, 20125 Milano (Italy); Tudisco, O. [Associazione Euratom-ENEA sulla Fusione, Via E. Fermi 45, 00044 Frascati (Italy)

    2014-12-15

    Peaked density profiles are observed in FTU discharges when the recycling condition of the chamber is influenced by the action of the liquid lithium limiter (LLL). Turbulence analysis of lithium doped FTU plasmas has shown that the presence of the light impurity modifies the phase between fluctuating fields responsible for transport and consequently leads to an inward deuterium pinch and outward impurity flux. Analogous peaked discharges were produced by Ne-gas puffing in different L mode plasma scenarios that have been recently obtained on FTU with following plasma parameters: I = 360 kA, B = 5–6.5 T, n{sub e0} = 0.2–1 × 10{sup 20} m{sup −3}, T{sub e0} = 1–4 keV, as well as in similar experiments on other machines. In fact the Ne seeded plasmas show an increase of the peaking factor around 30%. UV spectroscopy measurements confirm that the electron-density peaking arises from a convective flow and cannot be attributed to the contribution of the injected Ne alone. The Ne doped discharges analysis together with lithium conditioned ones is useful to extend the interpretative framework of the particle transport. In this work a comparison of the diffusion coefficient and of the pinch velocity of the two cases is conducted. By using a two-colors scanning interferometer providing very high spatial and time resolution, it is indeed possible to estimate the D and U coefficients of a simple model for the particle flux.

  13. Inherited susceptibility determines the distribution of dense low-density lipoprotein subfraction profiles in familial combined hyperlipidemia

    Energy Technology Data Exchange (ETDEWEB)

    Bredie, S.J.H.; Demacker, P.N.M.; Stalenhoef, A.F.H. [Univ. of Nijmegen (Netherlands)

    1996-04-01

    Familial combined hyperlipidemia (FCH) is a heritable lipid disorder, in which dense low-density lipoprotein (LDL) subfraction profiles due to a predominance of small dense LDL particles are frequently observed. These small dense LDL particles are associated with cardiovascular disease. Using segregation analysis, we investigated to what extent these LDL subfraction profiles are genetically determined; also, the mode of inheritance was studied. Individual LDL subfraction profiles were determined by density gradient ultracentrifugation in 623 individuals of 40 well-defined Dutch FCH families. The individual LDL subfraction profile was defined as a quantitative trait by the continuous variable K, a reliable estimate of the relative contribution of each LDL subfraction to the overall profile. Variation in parameter K due to age, sex, and hormonal status was taken into account by introducing liability classes. Segregation analysis was performed by fitting a series of class D regressive models were compared using log-likelihoot ratio tests. Our data show that 60% of the variability of parameter K could be explained by lipid and lipoprotein levels and that a major autosomal locus, recessively inherited, with a population frequency of .42 {+-} .07, and an additional polygenic component of .25 best explained the clustering of atherogenic dense LDL subfraction profiles in these FCH families. Therefore, dense LDL subfraction profiles, associated with elevated lipid levels, appear to have a genetic basis in FCH.

  14. Prediction of Process-Induced Distortions in L-Shaped Composite Profiles Using Path-Dependent Constitutive Law

    Science.gov (United States)

    Ding, Anxin; Li, Shuxin; Wang, Jihui; Ni, Aiqing; Sun, Liangliang; Chang, Lei

    2016-10-01

    In this paper, the corner spring-in angles of AS4/8552 L-shaped composite profiles with different thicknesses are predicted using path-dependent constitutive law with the consideration of material properties variation due to phase change during curing. The prediction accuracy mainly depends on the properties in the rubbery and glassy states obtained by homogenization method rather than experimental measurements. Both analytical and finite element (FE) homogenization methods are applied to predict the overall properties of AS4/8552 composite. The effect of fiber volume fraction on the properties is investigated for both rubbery and glassy states using both methods. And the predicted results are compared with experimental measurements for the glassy state. Good agreement is achieved between the predicted results and available experimental data, showing the reliability of the homogenization method. Furthermore, the corner spring-in angles of L-shaped composite profiles are measured experimentally and the reliability of path-dependent constitutive law is validated as well as the properties prediction by FE homogenization method.

  15. A Low-Profile Reflector-Enhanced Drop-Shaped Printed Antenna for Wide-Band Wireless Communications

    Directory of Open Access Journals (Sweden)

    Giovanni Cappelletti

    2017-01-01

    Full Text Available An improved low-profile printed antipodal drop-shaped dipole antenna for wide-band wireless applications is presented. The proposed radiating structure is integrated with a planar metal reflector useful to enhance antenna gain up to 5.5 dBi and the front-to-back ratio up to 21 dB. The geometry of reflector, feeding line, and dipole arms is optimized in order to achieve a broad operating bandwidth useful to meet the requirements of modern wireless communication protocols. Furthermore, the particular shape of the metal reflector and the adoption of a thin low-permittivity dielectric substrate result in a low distortion of the radiated field and a limited back radiation which makes the antenna suitable for UWB applications as well. These features, together with the low profile and the limited occupation area, make the antenna well adapted to mobile terminals as well as radio base stations. A locally conformal FDTD numerical procedure has been adopted to design and analyse the radiating structure, while a SEM technique has been employed to highlight the field perturbation caused by the antenna reflector as well as to extract the characteristics underlying the transient behaviour of the antenna. The experimental measurements performed on an antenna prototype are found to be in good agreement with the numerical computations.

  16. Tree resin composition, collection behavior and selective filters shape chemical profiles of tropical bees (Apidae: Meliponini).

    Science.gov (United States)

    Leonhardt, Sara D; Schmitt, Thomas; Blüthgen, Nico

    2011-01-01

    The diversity of species is striking, but can be far exceeded by the chemical diversity of compounds collected, produced or used by them. Here, we relate the specificity of plant-consumer interactions to chemical diversity applying a comparative network analysis to both levels. Chemical diversity was explored for interactions between tropical stingless bees and plant resins, which bees collect for nest construction and to deter predators and microbes. Resins also function as an environmental source for terpenes that serve as appeasement allomones and protection against predators when accumulated on the bees' body surfaces. To unravel the origin of the bees' complex chemical profiles, we investigated resin collection and the processing of resin-derived terpenes. We therefore analyzed chemical networks of tree resins, foraging networks of resin collecting bees, and their acquired chemical networks. We revealed that 113 terpenes in nests of six bee species and 83 on their body surfaces comprised a subset of the 1,117 compounds found in resins from seven tree species. Sesquiterpenes were the most variable class of terpenes. Albeit widely present in tree resins, they were only found on the body surface of some species, but entirely lacking in others. Moreover, whereas the nest profile of Tetragonula melanocephala contained sesquiterpenes, its surface profile did not. Stingless bees showed a generalized collecting behavior among resin sources, and only a hitherto undescribed species-specific "filtering" of resin-derived terpenes can explain the variation in chemical profiles of nests and body surfaces from different species. The tight relationship between bees and tree resins of a large variety of species elucidates why the bees' surfaces contain a much higher chemodiversity than other hymenopterans.

  17. Sizes and shapes of young star cluster light profiles in M83

    Science.gov (United States)

    Ryon, J. E.; Bastian, N.; Adamo, A.; Konstantopoulos, I. S.; Gallagher, J. S.; Larsen, S.; Hollyhead, K.; Silva-Villa, E.; Smith, L. J.

    2015-09-01

    We measure the radii and two-dimensional light profiles of a large sample of young, massive star clusters in M83 using archival HST/Wide Field Camera 3 (WFC3) imaging of seven adjacent fields. We use GALFIT to fit the two-dimensional light profiles of the clusters, from which we find effective (half-light) radii, core radii, and slopes of the power-law (EFF) profile (η). We find lognormal distributions of effective radius and core radius, with medians of ≈2.5 and ≈1.3 pc, respectively. Our results provide strong evidence for a characteristic size of young, massive clusters. The average effective radius and core radius increase somewhat with cluster age. Little to no change in effective radius is observed with increasing galactocentric distance, except perhaps for clusters younger than 100 Myr. We find a shallow correlation between effective radius and mass for the full cluster sample, but a stronger correlation is present for clusters 200-300 Myr in age. Finally, the majority of the clusters are best fit by an EFF model with index η ≲ 3.0. There is no strong evidence for change in η with cluster age, mass, or galactocentric distance. Our results suggest that clusters emerge from early evolution with similar radii and are not strongly affected by the tidal field of M83. Mass-loss due to stellar evolution and/or giant molecular cloud interactions appear to dominate cluster expansion in the age range we study.

  18. Numerical and Experimental Investigation of Turbulent Transport Control via Shaping of Radial Plasma Flow Profiles

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, Mark Allen [Univ. of New Mexico, Albuquerque, NM (United States)

    2017-02-05

    Turbulence, and turbulence-driven transport are ubiquitous in magnetically confined plasmas, where there is an intimate relationship between turbulence, transport, instability driving mechanisms (such as gradients), plasma flows, and flow shear. Though many of the detailed physics of the interrelationship between turbulence, transport, drive mechanisms, and flow remain unclear, there have been many demonstrations that transport and/or turbulence can be suppressed or reduced via manipulations of plasma flow profiles. This is well known in magnetic fusion plasmas [e.g., high confinement mode (H-mode) and internal transport barriers (ITB’s)], and has also been demonstrated in laboratory plasmas. However, it may be that the levels of particle transport obtained in such cases [e.g. H-mode, ITB’s] are actually lower than is desirable for a practical fusion device. Ideally, one would be able to actively feedback control the turbulent transport, via manipulation of the flow profiles. The purpose of this research was to investigate the feasibility of using both advanced model-based control algorithms, as well as non-model-based algorithms, to control cross-field turbulence-driven particle transport through appropriate manipulation of radial plasma flow profiles. The University of New Mexico was responsible for the experimental portion of the project, while our collaborators at the University of Montana provided plasma transport modeling, and collaborators at Lehigh University developed and explored control methods.

  19. Development of a method of ICP algorithm accuracy improvement during shaped profiles and surfaces control

    Directory of Open Access Journals (Sweden)

    V.A. Pechenin

    2014-10-01

    Full Text Available In this paper we propose a method of improvement of operating accuracy of iterative closest point algorithm used for metrology problems solving when determining a location deviation. Compressor blade profiles of a gas turbine engine (GTE were used as an object for application of the method of deviation determining. It is proposed to formulate the problem of the best alignment in the developed method as a multiobjective problem including criteria of minimum of squared distances, normal vectors differences and depth of camber differences at corresponding points of aligned profiles. Variants of resolving the task using an integral criterion including the above-mentioned were considered. Optimization problems were solved using a quasi- Newton method of sequential quadratic programming. The proposed new method of improvement of the registration algorithm based on geometric features showed greater accuracy in comparison with the discussed methods of optimization of a distance between fitting points, especially if a small quantity of measurement points on the profiles was used.

  20. [Attenuated Total Reflection Infrared Spectroscopy for Degradation Profile of High Density Polyethylene after Weathering Aging].

    Science.gov (United States)

    Guo, Jun-jun; Yan, Hua; Bao, He-bin; Wang, Xue-mei; Hu, Zhi-de; Yang, Jian-jian

    2015-06-01

    High density polyethylene (HDPE) was widely used as rotational packaging case in the material reserve field. The chemical changes of HDPE, exposed to particular climatic conditions of tropic marine atmosphere for one year-long in Wanning Hainan, were elucidated by the attenuated total reflection infrared spectroscopy (ATR-FTIR). The structural changes were studied qualitatively, mainly from the polymeric chain breaking, branching and oxidation to distinguish the degradation profile. The variations of crystallinity & carbonyl index were also studied quantitatively according to the characteristic peaks intensity & area ratio. Finally, the relationships between structural changes and mechanical properties were investigated. The results showed that the polymeric chain breaking & branching play a leading role before 3 months in the aging progress. Then oxidation phenomena gradually takes place during 3-6 months. The chain branching & oxidation were predominant factors after 6 months. Nine months later, the oxidation was saturated gradually. Furthermore, the aging process is positively correlated to the temperature and irradiation. After 12 months aging, the carbonyl index increased by 112 times and crystallinity was 10% higher than before. The tensile/bending modulus deceased faster than tensile/bending strength of HDPE. The linear degree of tensile modulus and carbonyl index was 0.97. The degree of linearity of tensile strength and crystallinity calculated by feature bands (720-730 cm(-1)) was 0.96. It showed that the mechanical properties of HDPE can be speculated from the structural changes by ATR-FTIR.

  1. Central depressions in the charge density profiles of the nuclei around $^{46}$Ar

    CERN Document Server

    Song, Jun Ling; Long, Wen Hui

    2015-01-01

    The occurrence of the proton bubble-like structure has been studied within the relativistic Hartree-Fock-Bogoliubov (RHFB) and relativistic Hartree-Bogoliubov (RHB) theories by exploring the bulk properties, the charge density profiles and single proton spectra of argon isotopes and $N = 28$ isotones. It is found that the RHFB calculations with PKA1 effective interaction, which can properly reproduce the charge radii of argon isotopes and the $Z=16$ proton shell nearby, do not support the occurrence of the proton bubble-like structure in argon isotopes due to the prediction of deeper bound proton orbit $\\pi2s_{1/2}$ than $\\pi1d_{3/2}$. For $N = 28$ isotones, $^{42}$Si and $^{40}$Mg are predicted by both RHFB and RHB models to have the proton bubble-like structure, owing to the large gap between the proton $\\pi2s_{1/2}$ and $\\pi1d_{5/2}$ orbits, namely the $Z=14$ proton shell. Therefore, $^{42}$Si is proposed as the potential candidate of proton bubble nucleus, which has longer life-time than $^{40}$Mg.

  2. A serum metabolomics-based profile in low bone mineral density postmenopausal women.

    Science.gov (United States)

    Miyamoto, Takeshi; Hirayama, Akiyoshi; Sato, Yuiko; Koboyashi, Tami; Katsuyama, Eri; Kanagawa, Hiroya; Miyamoto, Hiroya; Mori, Tomoaki; Yoshida, Shigeyuki; Fujie, Atsuhiro; Morita, Mayu; Watanabe, Ryuichi; Tando, Toshimi; Miyamoto, Kana; Tsuji, Takashi; Funayama, Atsushi; Nakamura, Masaya; Matsumoto, Morio; Soga, Tomoyoshi; Tomita, Masaru; Toyama, Yoshiaki

    2017-02-01

    Osteoporosis is characterized as a metabolic disorder of bone tissue, and various metabolic markers are now available to support its diagnosis and evaluate treatment effects. Substances produced as end products of metabolomic activities are the correlated factors to the biological or metabolic status, and thus, metabolites are considered highly sensitive markers of particular pathological states, including osteoporosis. Here we undertook comprehensive serum metabolomics analysis in postmenopausal women with or without low bone mineral density (low BMD vs controls) for the first time using capillary electrophoresis/mass spectrometry. Among the metabolites tested, 57 were detected in sera. Levels of hydroxyproline, Gly-Gly and cystine, differed significantly between groups, with Gly-Gly and cystine significantly lower in the low BMD group and hydroxyproline, a reported marker of osteoporosis, significantly higher. Levels of TRACP5b, a bone resorption marker, were significantly higher in the low BMD group, supporting the study's validity. Taken together, our findings represent novel metabolomic profiling in low BMD in postmenopausal women.

  3. RR Lyrae in XSTPS: The halo density profile in the North Galactic Cap

    CERN Document Server

    Faccioli, Lorenzo; Yuan, H -B; Zhang, H -H; Liu, X -W; Zhao, H -B; Yao, J -S

    2014-01-01

    We present a catalog of RR Lyrae stars (RRLs) observed by the Xuyi Schmidt Telescope Photometric Survey (XDSS). The area we consider is located in the North Galactic Cap, covering 376.75 sq deg at RA $\\approx$ 150 deg and Dec $\\approx$ 27 deg down to a magnitude limit of i $\\approx$ 19. Using the variability information afforded by the multi-epoch nature of our XDSS data, combined with colors from the Sloan Digital Sky Survey, we are able to identify candidate RRLs. We find 318 candidates, derive distances to them and estimate the detection efficiency. The majority of our candidates have more than 12 observations and for these we are able to calculate periods. These also allows us to estimate our contamination level, which we predict is between 30% to 40%. Finally we use the sample to probe the halo density profile in the 9-49 kpc range and find that it can be well fitted by a double power law. We find good agreement between this model and the models derived for the South Galactic Cap using the Watkins et al....

  4. Gravimetric and density profiling using the combination of surface acoustic waves and neutron reflectivity.

    Science.gov (United States)

    Toolan, Daniel T W; Barker, Robert; Gough, Tim; Topham, Paul D; Howse, Jonathan R; Glidle, Andrew

    2017-02-01

    A new approach is described herein, where neutron reflectivity measurements that probe changes in the density profile of thin films as they absorb material from the gas phase have been combined with a Love wave based gravimetric assay that measures the mass of absorbed material. This combination of techniques not only determines the spatial distribution of absorbed molecules, but also reveals the amount of void space within the thin film (a quantity that can be difficult to assess using neutron reflectivity measurements alone). The uptake of organic solvent vapours into spun cast films of polystyrene has been used as a model system with a view to this method having the potential for extension to the study of other systems. These could include, for example, humidity sensors, hydrogel swelling, biomolecule adsorption or transformations of electroactive and chemically reactive thin films. This is the first ever demonstration of combined neutron reflectivity and Love wave-based gravimetry and the experimental caveats, limitations and scope of the method are explored and discussed in detail.

  5. Global characteristics of the upper transition height derived from the topside Alouette/ISIS topside sounder electron density profiles, the Formosat-3/COSMIC density profiles and the IRI ion composition model

    Science.gov (United States)

    Truhlik, Vladimir; Triskova, Ludmila; Benson, Robert; Bilitza, Dieter; Chu, Philip; Richards, Phil G.; Wang, Yongli

    The upper transition height (Ht) (the altitude of the transition from heavy atomic ions to light ions or in the simplest form the transition from O+ to H+) is an important parameter, representing the boundary between the ionosphere and the plasmasphere. Ht is very sensitive to various geophysical parameters, like solar and magnetic activity and strongly depends on latitude and local time. There were numerous studies of this parameter in past decades. In spite of these efforts, no model satisfactorily represents this parameter so far. Moreover, surprising evidence of very low transition heights during the last prolonged solar minimum, of a level never obtained before, have been reported. We investigate the upper transition height on the global scale. We made progress in processing large data sets of Ht deduced from the Alouette/ISIS topside sounder and from the Formosat-3/COSMIC vertical electron-density profiles Ne(h) using the theoretical Global Plasma Ionosphere Density (GPID) model (Webb and Essex, 2004) and a revised non-linear function describing the scale height vs. altitude (Titheridge, 1976) to fit the vertical density profiles to the observed profiles and to determine the upper transition height. Since both methods require the plasma temperatures and their gradients as input, these are calculated using the IRI2012 model. Both methods are verified using a large amount of electron and ion density profiles simulated by the FLIP theoretical model and their accuracy is discussed. We compare the results from Alouette/ISIS and Formosat-3/COSMIC and present a global distribution of the calculated Ht and its dependence on geophysical parameters. Finally we compare it with Ht calculated using the IRI ion composition model. Titheridge, J.E., 1976. Ion Transition Heights from Topside Electron-Density Profiles. Planetary and Space Science 24 (3), 229-245. Webb, P.A., Essex, E.A., 2004. A dynamic global model of the plasmasphere. Journal of Atmospheric and Solar

  6. Final Technical Report: Numerical and Experimental Investigation of Turbulent Transport Control via Shaping of Radial Plasma Flow Profiles

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Eugenio

    2014-05-02

    The strong coupling between the different physical variables involved in the plasma transport phenomenon and the high complexity of its dynamics call for a model-based, multivariable approach to profile control where those predictive models could be exploited. The overall objective of this project has been to extend the existing body of work by investigating numerically and experimentally active control of unstable fluctuations, including fully developed turbulence and the associated cross-field particle transport, via manipulation of flow profiles in a magnetized laboratory plasma device. Fluctuations and particle transport can be monitored by an array of electrostatic probes, and Ex B flow profiles can be controlled via a set of biased concentric ring electrodes that terminate the plasma column. The goals of the proposed research have been threefold: i- to develop a predictive code to simulate plasma transport in the linear HELCAT (HELicon-CAThode) plasma device at the University of New Mexico (UNM), where the experimental component of the proposed research has been carried out; ii- to establish the feasibility of using advanced model-based control algorithms to control cross-field turbulence-driven particle transport through appropriate manipulation of radial plasma flow profiles, iii- to investigate the fundamental nonlinear dynamics of turbulence and transport physics. Lehigh University (LU), including Prof. Eugenio Schuster and one full-time graduate student, has been primarily responsible for control-oriented modeling and model-based control design. Undergraduate students have also participated in this project through the National Science Foundation Research Experience for Undergraduate (REU) program. The main goal of the LU Plasma Control Group has been to study the feasibility of controlling turbulence-driven transport by shaping the radial poloidal flow profile (i.e., by controlling flow shear) via biased concentric ring electrodes.

  7. Charge and current density profiles of a degenerate magnetized free-electron gas near a hard wall

    NARCIS (Netherlands)

    M.M. Kettenis; L.G. Suttorp

    1998-01-01

    The charge and current densities of a completely degenerate free-electron gas in a uniform magnetic field are found to have a damped oscillatory spatial dependence near a wall that is parallel to the magnetic field. For large distances from the wall the behaviour of the associated profile functions

  8. Stereolithography based method of creating custom gas density profile targets for high intensity laser-plasma experiments.

    Science.gov (United States)

    Jolly, S W; He, Z; McGuffey, C; Schumaker, W; Krushelnick, K; Thomas, A G R

    2012-07-01

    Laser based stereolithography methods are shown to be useful for production of gas targets for high intensity laser-plasma interaction experiments. A cylindrically symmetric nozzle with an opening of approximately 100 μm and a periodic attachment of variable periodicity are outlined in detail with associated density profile characterization. Both components are durable within the limits of relevant experiments.

  9. Carotenoid profiling from 27 types of paprika (Capsicum annuum L.) with different colors, shapes, and cultivation methods.

    Science.gov (United States)

    Kim, Ji-Sun; An, Chul Geon; Park, Jong-Suk; Lim, Yong Pyo; Kim, Suna

    2016-06-15

    In this study, we investigated carotenoid profiles and contents from 27 types of paprika with different colors (red, orange, and yellow), shapes (blocky and conical), and cultivation methods (soil and soilless). We simultaneously analyzed 12 kinds of carotenoids using UPLC equipped with an HSS T3 column for 30 min, and we identified six kinds of carotenoids in red paprika and nine types in orange and yellow paprika. Zeaxanthin concentrations in orange paprika were in the range of 85.06±23.37-151.39±5.94 mg/100 g dry weight (dw), which shows that orange paprika is a great source of zeaxanthin. Generally, red paprika is a great source of capsanthin. However, a new cultivar, 'Mini Goggal Red', contained large amounts of zeaxanthin (121.41±30.10 mg/100 g dw) even though its visible color is red. This is very meaningful considering that consumers have a preference for red color and the potent functional value of zeaxanthin. Carotenoid profiles and concentrations in blocky and conical type paprika were not significantly different in red paprika except the 'Mini Goggal Red' cultivar and yellow paprika. Blocky type orange paprika contains plenty of zeaxanthin, unlike conical type orange paprika. Three new cultivars of the conical type were cultivated in both soil culture and soilless culture in the same province, and carotenoid profiles and concentrations were similar, showing that both cultivations methods can be used.

  10. Derivation of the Fano profile from time-dependent density-functional theory for local thermodynamic equilibrium plasmas

    Science.gov (United States)

    Kiyokawa, Shuji

    2007-04-01

    We give the derivation of the Fano profile (the resonance energy position, the resonance width Γ , and q value) from the time-dependent nonrelativistic density-functional theory (DFT) and propose a scheme for calculating the photoabsorption cross section of hot dense plasmas. As a consequence of this derivation, we show the line profile is obtained as a superposition of Fano and Lorentz profiles when the competition of two optically allowed bound-bound and bound-free transitions occurs. We also show the results of the photoabsorption cross section by applying our scheme to an Fe plasma (density is 7.85g/cm3 , temperature is 100eV ), where the calculation is carried out without numerical divergence for any photon energy. The calculated results are in good agreement with those of Grimaldi.

  11. Liquid drops on a surface: Using density functional theory to calculate the binding potential and drop profiles and comparing with results from mesoscopic modelling

    Science.gov (United States)

    Hughes, Adam P.; Thiele, Uwe; Archer, Andrew J.

    2015-02-01

    The contribution to the free energy for a film of liquid of thickness h on a solid surface due to the interactions between the solid-liquid and liquid-gas interfaces is given by the binding potential, g(h). The precise form of g(h) determines whether or not the liquid wets the surface. Note that differentiating g(h) gives the Derjaguin or disjoining pressure. We develop a microscopic density functional theory (DFT) based method for calculating g(h), allowing us to relate the form of g(h) to the nature of the molecular interactions in the system. We present results based on using a simple lattice gas model, to demonstrate the procedure. In order to describe the static and dynamic behaviour of non-uniform liquid films and drops on surfaces, a mesoscopic free energy based on g(h) is often used. We calculate such equilibrium film height profiles and also directly calculate using DFT the corresponding density profiles for liquid drops on surfaces. Comparing quantities such as the contact angle and also the shape of the drops, we find good agreement between the two methods. We also study in detail the effect on g(h) of truncating the range of the dispersion forces, both those between the fluid molecules and those between the fluid and wall. We find that truncating can have a significant effect on g(h) and the associated wetting behaviour of the fluid.

  12. Shape of the oxygen abundance profiles in CALIFA face-on spiral galaxies

    CERN Document Server

    Sánchez-Menguiano, L; Pérez, I; García-Benito, R; Husemann, B; Mast, D; Mendoza, A; Ruiz-Lara, T; Ascasibar, Y; Bland-Hawthorn, J; Cavichia, O; Díaz, A I; Florido, E; Galbany, L; Delgado, R M Gónzalez; Kehrig, C; Marino, R A; Márquez, I; Masegosa, J; Méndez-Abreu, J; Mollá, M; del Olmo, A; Pérez, E; Sánchez-Blázquez, P; Stanishev, V; Walcher, C J; López-Sánchez, Á R

    2016-01-01

    We measured the gas abundance profiles in a sample of 122 face-on spiral galaxies observed by the CALIFA survey and included all spaxels whose line emission was consistent with star formation. This type of analysis allowed us to improve the statistics with respect to previous studies, and to properly estimate the oxygen distribution across the entire disc to a distance of up to 3-4 disc effective radii (r$_e$). We confirm the results obtained from classical HII region analysis. In addition to the general negative gradient, an outer flattening can be observed in the oxygen abundance radial profile. An inner drop is also found in some cases. There is a common abundance gradient between 0.5 and 2.0 r$_e$ of $\\alpha_{O/H} = -\\,0.075\\,\\rm{dex}/r_e$ with a scatter of $\\sigma = 0.016\\,\\rm{dex}/r_e$ when normalising the distances to the disc effective radius. By performing a set of Kolmogorov-Smirnov tests, we determined that this slope is independent of other galaxy properties, such as morphology, absolute magnitude...

  13. The effects of ellipticity and substructure on estimates of cluster density profiles based on lensing and kinematics

    Science.gov (United States)

    Meneghetti, Massimo; Bartelmann, Matthias; Jenkins, Adrian; Frenk, Carlos

    2007-10-01

    We address the question of how well the density profile of galaxy clusters can be determined by combining strong lensing and velocity dispersion data. We use cosmological dark matter simulations of clusters to test the reliability of the method, producing mock catalogues of tangential and radial gravitational arcs and simulating the radial velocity dispersion profile of the cluster brightest central galaxy. The density profiles of the simulated clusters closely follow the Navarro, Frenk & White (NFW) form, but we find that the recovered values of the inner slope are systematically underestimated, by about 0.4 in the mean, if the lens is assumed to be axially symmetric. However, if the ellipticity and orientation of the isocontours of the cluster lensing potential are taken into account, then the inner slopes can be recovered quite accurately for a significant subset of the clusters whose central surface density profiles appear the most regular. These have lensing potentials with ellipticities in the range 0.15-0.4. Further simulations projecting one cluster along many random lines of sight show that, even for lower ellipticities, the central slopes are underestimated by ~10-35per cent. These simulations closely mimic past observations, suggesting that existing estimates of the central slopes may be biased towards low values. For the remaining clusters, where the lensing potential is strongly perturbed by active merging or by substructure, the correct determination of the inner slope requires a more accurate model for the lens. When the halo profile is modelled by a generalized NFW profile, we find that the inferred scale radius and characteristic density, unlike the inner slope, are generally poorly constrained, since there is a strong degeneracy between these two parameters.

  14. Improved density profile measurements in the C-2U advanced beam-driven Field-Reversed Configuration (FRC) plasmas

    Science.gov (United States)

    Beall, M.; Deng, B. H.; Gota, H.

    2016-11-01

    In the prior C-2 experiment, electron density was measured using a two-color 6-chord CO2/HeNe interferometer. Analysis shows that high-frequency common mode phase noise can be reduced by a factor of 3 by constructing a reference chord. In the system upgrade from C-2 to C-2U a 4-chord far-infrared laser interferometer was developed, which demonstrated superior sensitivity (1 × 1016 m-2 at >1 MHz bandwidth) and solved the under spatial sampling issue of the C-2 interferometer system. Improved density-profile measurement results are presented in this paper, including evidence of fast-ion modified density profile and stabilization of the n = 1 plasma wobble mode.

  15. Design of Q-band FMCW reflectometry for electron density profile measurement on the Joint TEXT tokamak

    Science.gov (United States)

    Linghan, Wan; Zhoujun, Yang; Ruobing, Zhou; Xiaoming, Pan; Chi, Zhang; Xianli, Xie; Bowen, Ruan

    2017-02-01

    The Q-band (33-50 GHz) fast sweep frequency modulated continuous wave (FMCW) reflectometry has been recently developed for electron density profile measurement on the Joint TEXT tokamak. It operates in ordinary mode (O-mode) with a 20 μs sweeping period, covering the density range from 1 × 1019 m-3 to 3 × 1019 m-3. On the bench test, a Yttrium Iron Garnet (YIG) filter is used for the dynamic calibration of the voltage controlled oscillator (VCO) to obtain a linear frequency sweep. Besides, the use of a power combiner helps to improve the side-band suppression level of the single side-band modulator (SSBM). The reconstructed density profiles are presented, which demonstrate the capability of the reflectometry.

  16. The Favourable Choice of the Shape of Billet's Contact Surface to Quality of Extruded Aluminium Profiles

    Directory of Open Access Journals (Sweden)

    G. Skorulski

    2010-07-01

    Full Text Available The theoretical and experimental method of optimization the aluminium billet’s contact surface during extrusion have been presented inthis paper. The theoretical assumption, based on welding criteria, have been confirmed by experimental researches. The technique ofmeasurement has been shown as well. Experiments are made using plasticine as a substiute material. Some kind of different variants have been investigated. The theory and experiments have been provided to optimize the modeling shape and may help in design and technology.The theory has been tested experimentally using a plasticine as a substitute material and a plexiglass die such that the velocity fields at the surfaces could be observed and measured during plastic flow, allowing the empirical coefficients in the mathematical formulation to be estimated. On the basis of the theory and experiments an optimal billet’s contact surface was proposed.

  17. Pre-flyby Determination Of The Size, Shape, Pole, Density, And Satellites Of (21) Lutetia From Ground-based Observations

    Science.gov (United States)

    Merline, William J.; Carry, B.; Drummond, J. D.; Conrad, A.; Chapman, C. R.; Kaasalainen, M.; Leyrat, C.; Weaver, H. A.; Tamblyn, P. M.; Christou, J. C.; Dumas, C.; Kryszczynska, A.; Colas, F.; Bernasconi, L.; Behrend, R.; Vachier, F.; Polinska, M.; Roy, R.; Naves, R.; Poncy, R.; Wiggins, P.

    2010-10-01

    Prior to the flyby of (21) Lutetia by Rosetta, we initiated a campaign of observations to characterize the system, primarily using ground-based adaptive optics (AO) on large telescopes, including Keck, Gemini, and VLT. We coordinated these efforts with HST observations (Weaver et al. 2010 A&A in press) made in support of the Rosetta ALICE UV spectrometer. Lutetia was 0.10" in diameter, allowing disk-resolved imaging with AO and tracking of its shape during rotation. We modeled the shape using both a triaxial-ellipsoid model (Drummond et al. 2010 A&A submitted) and a full 3D radius-vector model (Carry et al. 2010 A&A submitted, in which we combine AO imaging with decades of lightcurve data to produce an improved 3D model using our inversion algorithm KOALA). To overcome limitations in each model, we combined the best aspects of each to produce our best-estimate 3D shape model, a hybrid having ellipsoid-equivalent dimensions of 124 x 101 x 93 km (± 5 x 4 x 13 km) and effective diameter 105 ± 7 km. We find the spin axis of Lutetia to lie within 5 deg of [long, lat (52,-6)] or [RA DEC (52,+12)], and determine an improved sidereal period of 8.168270 ± 0.000001 h. We predicted the geometry of Lutetia during the flyby and showed that the southern hemisphere would be in seasonal shadow at that time. The model suggests the presence of several concavities that may be associated with large impacts. Using two separately determined masses and the volume of our hybrid model, we estimate a density of 3.5 ± 1.1 or 4.3 ± 0.8 g/cc, favoring an enstatite-chondrite composition for this large M-type asteroid, although other compositions are formally allowed. No satellites larger than 1 km diameter were detected in the AO-data over a significant fraction of the Hill sphere (10-240 asteroid radii).

  18. The specific entropy of elliptical galaxies an explanation for profile-shape distance indicators?

    CERN Document Server

    Lima-Neto, G B; Márquez, I; Neto, Gastao B. Lima; Gerbal, Daniel; Marquez, Isabel

    1999-01-01

    Dynamical systems in equilibrium have a stationary entropy; we suggest that elliptical galaxies, as stellar systems in a stage of quasi-equilibrium, may have a unique specific entropy. This uniqueness, a priori unknown, should be reflected in correlations between the parameters describing the mass (light) distribution in galaxies. Following recent photometrical work (Caon et al. 1993; Graham & Colless 1997; Prugniel & Simien 1997), we use the Sersic law to describe the light profile of elliptical galaxies and an analytical approximation to its three dimensional deprojection. The specific entropy is calculated supposing that the galaxy behaves as a spherical, isotropic, one-component system in hydrostatic equilibrium, obeying the ideal gas state equations. We predict a relation between the 3 parameters of the Sersic, defining a surface in the parameter space, an `Entropic Plane', by analogy with the well-known Fundamental Plane. We have analysed elliptical galaxies in Coma and ABCG 85 clusters and a gr...

  19. The surface density profile of NGC 6388 : a good candidate for harboring an intermediate-mass black hole

    CERN Document Server

    Lanzoni, B; Ferraro, F R; Miocchi, P; Valenti, E; Rood, R T

    2007-01-01

    We have used a combination of high resolution (HST ACS-HRC, ACS-WFC, and WFPC2) and wide-field (ESO-WFI) observations of the galactic globular cluster NGC 6388 to derive its center of gravity, projected density profile, and central surface brightness profile. While the overall projected profiles are well fit by a King model with intermediate concentration (c=1.8) and sizable core radius (rc=7"), a significant power law (with slope \\alpha=-0.2) deviation from a flat core behavior has been detected within the inner 1 arcsecond. These properties suggest the presence of a central intermediate mass black hole. The observed profiles are well reproduced by a multi-mass isotropic, spherical model including a black hole with a mass of ~5.7x10^3 Msol.

  20. Shaping the PSF to nearly top-hat profile: CHEOPS laboratory results

    Science.gov (United States)

    Magrin, Demetrio; Farinato, Jacopo; Umbriaco, Gabriele; Kumar Radhakrishnan Santhakumari, Kalyan; Bergomi, Maria; Dima, Marco; Greggio, Davide; Marafatto, Luca; Ragazzoni, Roberto; Viotto, Valentina; Munari, Matteo; Pagano, Isabella; Scandariato, Gaetano; Scuderi, Salvatore; Piotto, Giampaolo; Beck, Thomas; Benz, Willy; Broeg, Christopher; Cessa, Virginie; Fortier, Andrea; Piazza, Daniele

    2014-08-01

    Spreading the PSF over a quite large amount of pixels is an increasingly used observing technique in order to reach extremely precise photometry, such as in the case of exoplanets searching and characterization via transits observations. A PSF top-hat profile helps to minimize the errors contribution due to the uncertainty on the knowledge of the detector flat field. This work has been carried out during the recent design study in the framework of the ESA small mission CHEOPS. Because of lack of perfect flat-fielding information, in the CHEOPS optics it is required to spread the light of a source into a well defined angular area, in a manner as uniform as possible. Furthermore this should be accomplished still retaining the features of a true focal plane onto the detector. In this way, for instance, the angular displacement on the focal plane is fully retained and in case of several stars in a field these look as separated as their distance is larger than the spreading size. An obvious way is to apply a defocus, while the presence of an intermediate pupil plane in the Back End Optics makes attractive to introduce here an optical device that is able to spread the light in a well defined manner, still retaining the direction of the chief ray hitting it. This can be accomplished through an holographic diffuser or through a lenslet array. Both techniques implement the concept of segmenting the pupil into several sub-zones where light is spread to a well defined angle. We present experimental results on how to deliver such PSF profile by mean of holographic diffuser and lenslet array. Both the devices are located in an intermediate pupil plane of a properly scaled laboratory setup mimicking the CHEOPS optical design configuration.

  1. The specific entropy of elliptical galaxies: an explanation for profile-shape distance indicators?

    Science.gov (United States)

    Lima Neto, G. B.; Gerbal, D.; Márquez, I.

    1999-10-01

    Dynamical systems in equilibrium have a stationary entropy; we suggest that elliptical galaxies, as stellar systems in a stage of quasi-equilibrium, may have in principle a unique specific entropy. This uniqueness, a priori unknown, should be reflected in correlations between the fundamental parameters describing the mass (light) distribution in galaxies. Following recent photometrical work on elliptical galaxies by Caon et al., Graham & Colless and Prugniel & Simien, we use the Sérsic law to describe the light profile and an analytical approximation to its three-dimensional deprojection. The specific entropy is then calculated, supposing that the galaxy behaves as a spherical, isotropic, one-component system in hydrostatic equilibrium, obeying the ideal-gas equations of state. We predict a relation between the three parameters of the Sérsic law linked to the specific entropy, defining a surface in the parameter space, an `Entropic Plane', by analogy with the well-known Fundamental Plane. We have analysed elliptical galaxies in two rich clusters of galaxies (Coma and ABCG 85) and a group of galaxies (associated with NGC 4839, near Coma). We show that, for a given cluster, the galaxies follow closely a relation predicted by the constant specific entropy hypothesis with a typical dispersion (one standard deviation) of 9.5per cent around the mean value of the specific entropy. Moreover, assuming that the specific entropy is also the same for galaxies of different clusters, we are able to derive relative distances between Coma, ABGC 85, and the group of NGC 4839. If the errors are due only to the determination of the specific entropy (about 10per cent), then the error in the relative distance determination should be less than 20per cent for rich clusters. We suggest that the unique specific entropy may provide a physical explanation for the distance indicators based on the Sérsic profile put forward by Young & Currie and recently discussed by Binggeli & Jerjen.

  2. Compact and high-particle-flux thermal-lithium-beam probe system for measurement of two-dimensional electron density profile.

    Science.gov (United States)

    Shibata, Y; Manabe, T; Kajita, S; Ohno, N; Takagi, M; Tsuchiya, H; Morisaki, T

    2014-09-01

    A compact and high-particle-flux thermal-lithium-beam source for two-dimensional measurement of electron density profiles has been developed. The thermal-lithium-beam oven is heated by a carbon heater. In this system, the maximum particle flux of the thermal lithium beam was ~4 × 10(19) m(-2) s(-1) when the temperature of the thermal-lithium-beam oven was 900 K. The electron density profile was evaluated in the small tokamak device HYBTOK-II. The electron density profile was reconstructed using the thermal-lithium-beam probe data and this profile was consistent with the electron density profile measured with a Langmuir electrostatic probe. We confirm that the developed thermal-lithium-beam probe can be used to measure the two-dimensional electron density profile with high time and spatial resolutions.

  3. Microbial symbionts shape the sterol profile of the xylem-feeding woodwasp, Sirex noctilio.

    Science.gov (United States)

    Thompson, Brian M; Grebenok, Robert J; Behmer, Spencer T; Gruner, Daniel S

    2013-01-01

    The symbiotic fungus Amylostereum areolatum is essential for growth and development of larvae of the invasive woodwasp, Sirex noctilio. In the nutrient poor xylem of pine trees, upon which Sirex feeds, it is unknown whether Amylostereum facilitates survival directly through consumption (mycetophagy) and/or indirectly through digestion of recalcitrant plant polymers (external rumen hypothesis). We tested these alternative hypotheses for Amylostereum involvement in Sirex foraging using the innate dependency of all insects on dietary sources of sterol and the unique sterols indicative of fungi and plants. We tested alternative hypotheses by using GC-MS to quantify concentrations of free and bound sterol pools from multiple life-stages of Sirex, food sources, and waste products in red pine (Pinus resinosa). Cholesterol was the primary sterol found in all life-stages of Sirex. However, cholesterol was not found in significant quantities in either plant or fungal resources. Ergosterol was the most prevalent sterol in Amylostereum but was not detectable in either wood or insect tissue (importance for fungal enzymes, including the external digestion of recalcitrant plant polymers (e.g., lignin and cellulose), shaping this insect-fungal symbiosis.

  4. Energy constancy checking for electron beams using a wedge-shaped solid phantom combined with a beam profile scanner

    Energy Technology Data Exchange (ETDEWEB)

    Rosenow, U.F.; Islam, M.K.; Gaballa, H.; Rashid, H. (Univ. of Goettingen (Germany, F.R.))

    1991-01-01

    An energy constancy checking method is presented which involves a specially designed wedge-shaped solid phantom in combination with a multiple channel ionization chamber array known as the Thebes device. Once the phantom/beam scanner combination is set up, measurements for all electron energies can be made and evaluated without re-entering the treatment room. This is also valid for the readjustment of beam energies which are found to deviate from required settings. The immediate presentation of the measurements is in the form of crossplots which resemble depth dose profiles. The evaluation of the measured data can be performed using a hand-held calculator, but processing of the measured signals through a PC-type computer is advisable. The method is insensitive to usual fluctuations in beam flatness. The sensitivity and reproducibility of the method are more than adequate. The method may also be used in modified form for photon beams.

  5. Energy constancy checking for electron beams using a wedge-shaped solid phantom combined with a beam profile scanner.

    Science.gov (United States)

    Rosenow, U F; Islam, M K; Gaballa, H; Rashid, H

    1991-01-01

    An energy constancy checking method is presented which involves a specially designed wedge-shaped solid phantom in combination with a multiple channel ionization chamber array known as the Thebes device. Once the phantom/beam scanner combination is set up, measurements for all electron energies can be made and evaluated without re-entering the treatment room. This is also valid for the readjustment of beam energies which are found to deviate from required settings. The immediate presentation of the measurements is in the form of crossplots which resemble depth dose profiles. The evaluation of the measured data can be performed using a hand-held calculator, but processing of the measured signals through a PC-type computer is advisable. The method is insensitive to usual fluctuations in beam flatness. The sensitivity and reproducibility of the method are more than adequate. The method may also be used in modified form for photon beams.

  6. Analytic Elastic Cross Sections for Electron-Atom Scattering from Generalized Fano Profiles of Overlapping Low-Energy Shape Resonances

    CERN Document Server

    Nicoletopoulos, P

    2003-01-01

    The variation with energy of the total cross section for elastic electron scattering from atoms of several elements is caused primarily by shape resonances corresponding to the formation of temporary negative ions. It is shown that such cross sections are expressible analytically in terms of a constant background added to a "generalized Fano profile" [Durand Ph, et al (2001) J. Phys. B: At. Mol. Opt. Phys. 34, 1953, ibid (2002) 35, 469]. In three cases (sodium, magnesium and mercury), a detailed consideration proves that this representation is accurate in a fairly wide energy range. Moreover, the related momentum transfer cross sections are tailor-made for studying "elastic" electron transport in terms of the two-term solution of the Boltzmann equation: Not only are the resulting swarm transport coefficients adjustable to the experimental values, but above all they are calculable very easily because the unnormalized energy distribution is obtainable analytically. The ample saving in computational effort is ex...

  7. Density profile of dark matter haloes and galaxies in the Horizon-AGN simulation: the impact of AGN feedback

    CERN Document Server

    Peirani, S; Volonteri, M; Devriendt, J; Bundy, K; Silk, J; Pichon, C; Kaviraj, S; Gavazzi, R; Habouzit, M

    2016-01-01

    Using a suite of three large cosmological hydrodynamical simulations, Horizon-AGN, Horizon-noAGN (no AGN feedback) and Horizon-DM (no baryons), we investigate how a typical sub-grid model for AGN feedback affects the evolution of the inner density profiles of massive dark matter haloes and galaxies. Based on direct object-to-object comparisons, we find that the integrated inner mass and density slope differences between objects formed in these three simulations (hereafter, H_AGN, H_noAGN and H_DM) significantly evolve with time. More specifically, at high redshift (z~5), the mean central density profiles of H_AGN and H_noAGN dark matter haloes tend to be much steeper than their H_DM counterparts owing to the rapidly growing baryonic component and ensuing adiabatic contraction. By z~1.5, these mean halo density profiles in H_AGN have flattened, pummelled by powerful AGN activity ("quasar mode"): the integrated inner mass difference gaps with H_noAGN haloes have widened, and those with H_DM haloes have narrowed...

  8. Limits on the power-law mass and luminosity density profiles of elliptical galaxies from gravitational lensing systems

    Science.gov (United States)

    Cao, Shuo; Biesiada, Marek; Yao, Meng; Zhu, Zong-Hong

    2016-09-01

    We use 118 strong gravitational lenses observed by the SLACS, BOSS emission-line lens survey (BELLS), LSD and SL2S surveys to constrain the total mass profile and the profile of luminosity density of stars (light tracers) in elliptical galaxies up to redshift z ˜ 1. Assuming power-law density profiles for the total mass density, ρ = ρ0(r/r0)-α, and luminosity density, ν = ν0(r/r0)-δ, we investigate the power-law index and its first derivative with respect to the redshift. Using Monte Carlo simulations of the posterior likelihood taking the Planck's best-fitting cosmology as a prior, we find γ = 2.132 ± 0.055 with a mild trend ∂γ/∂zl = -0.067 ± 0.119 when α = δ = γ, suggesting that the total density profile of massive galaxies could have become slightly steeper over cosmic time. Furthermore, similar analyses performed on sub-samples defined by different lens redshifts and velocity dispersions indicate the need of treating low-, intermediate- and high-mass galaxies separately. Allowing δ to be a free parameter, we obtain α = 2.070 ± 0.031, ∂α/∂zl = -0.121 ± 0.078 and δ = 2.710 ± 0.143. The model in which mass traces light is rejected at >95 per cent confidence, and our analysis robustly indicates the presence of dark matter in the form of a mass component that is differently spatially extended than the light. In this case, intermediate-mass elliptical galaxies (200 km s-1 <σap ≤ 300 km s-1) show the best consistency with the singular isothermal sphere as an effective model of galactic lenses.

  9. Variability of the bottomside (B0, B1) profile parameters of ionospheric electron density over the lower mid-latitude Cyprus and comparisons with IRI-2012 model

    Science.gov (United States)

    Panda, Sampad Kumar; Haralambous, Haris; Mostafa, Md Golam

    2016-07-01

    The present study investigates the variations of the bottomside ionospheric electron density profile thickness (B0) and shape (B1) parameters, deduced from the manually scaled digisonde (DPS-4D) ionograms at the lower mid-latitude Cyprus (Geographic 35°N, 33°E) covering the period 2009-2014. The monthly median hourly values of these parameters during different seasons and solar activity conditions are compared with the International Reference Ionosphere model (IRI-2012) estimations using three different options namely: Bil-2000, Gul-1987, and ABT-2009. To ensure the quiet time profile, the ionograms of the geomagnetically disturbed periods are discarded from the datasets and the storm model in the IRI is intentionally turned off. The statistical studies reveal considerable discrepancies in the observed B0 parameters from the model simulations, though the divergences are minimal around the daytime and during the summer solstice seasons. Nevertheless, B0 with the Gul-1987 option apparently shows closer daytime value during the low solar active summer, whereas the ABT-2009 option manifested relatively better agreement during the high solar active summer months. The characteristic morning, evening, as well as nighttime departure in the model derived B0 parameters are conspicuous in all the seasons in spite of unnoticed perturbations in the B1, suggesting that further improvement in the existing model database is essential with additional in-situ experimental data across the lower mid-latitude region. The important extracts from this study may support in the international efforts of determining the best set of profile parameters for the climatological representation of the ionospheric electron density variation across the globe.

  10. NIHAO project II: halo shape, phase-space density and velocity distribution of dark matter in galaxy formation simulations

    Science.gov (United States)

    Butsky, Iryna; Macciò, Andrea V.; Dutton, Aaron A.; Wang, Liang; Obreja, Aura; Stinson, Greg S.; Penzo, Camilla; Kang, Xi; Keller, Ben W.; Wadsley, James

    2016-10-01

    We use the NIHAO (Numerical Investigation of Hundred Astrophysical Objects) cosmological simulations to study the effects of galaxy formation on key properties of dark matter (DM) haloes. NIHAO consists of ≈90 high-resolution smoothed particle hydrodynamics simulations that include (metal-line) cooling, star formation, and feedback from massive stars and supernovae, and cover a wide stellar and halo mass range: 106 ≲ M*/M⊙ ≲ 1011(109.5 ≲ Mhalo/M⊙ ≲ 1012.5). When compared to DM-only simulations, the NIHAO haloes have similar shapes at the virial radius, Rvir, but are substantially rounder inside ≈0.1Rvir. In NIHAO simulations, c/a increases with halo mass and integrated star formation efficiency, reaching ˜0.8 at the Milky Way mass (compared to 0.5 in DM-only), providing a plausible solution to the long-standing conflict between observations and DM-only simulations. The radial profile of the phase-space Q parameter (ρ/σ3) is best fit with a single power law in DM-only simulations, but shows a flattening within ≈0.1Rvir for NIHAO for total masses M > 1011 M⊙. Finally, the global velocity distribution of DM is similar in both DM-only and NIHAO simulations, but in the solar neighbourhood, NIHAO galaxies deviate substantially from Maxwellian. The distribution is more symmetric, roughly Gaussian, with a peak that shifts to higher velocities for Milky Way mass haloes. We provide the distribution parameters which can be used for predictions for direct DM detection experiments. Our results underline the ability of the galaxy formation processes to modify the properties of DM haloes.

  11. Shape Memory Polymer Composites of Poly(styrene-b-butadiene-b-styrene Copolymer/Liner Low Density Polyethylene/Fe3O4 Nanoparticles for Remote Activation

    Directory of Open Access Journals (Sweden)

    Yongkun Wang

    2016-11-01

    Full Text Available Magnetically sensitive shape memory poly(styrene-b-butadiene-b-styrene copolymer (SBS/liner low density polyethylene (LLDPE composites filled with various contents of Fe3O4 nanoparticles were prepared. The influence of the Fe3O4 nanoparticles content on the thermal properties, mechanical properties, fracture morphology, magnetic behavior, and shape memory effect of SBS/LLDPE/Fe3O4 composites was systematically studied in this paper. The results indicated that homogeneously dispersed Fe3O4 nanoparticles ensured the uniform heat generation and transfer in the alternating magnetic field, and endowed the SBS/LLDPE/Fe3O4 composites with an excellent magnetically responsive shape memory effect. When the shape memory composites were in the alternating magnetic field (f = 60 kHz, H = 21.21 kA·m−1, the best shape recovery ratio reached 99%, the shape retention ratio reached 99.4%, and the shape recovery speed increased significantly with the increment of Fe3O4 nanoparticles. It is anticipated that tagging products with this novel shape memory composite is helpful for the purpose of an intravascular delivery system in Micro-Electro-Mechanical System (MEMS devices.

  12. Characterizing intra-annual density fluctuations using fine-spatial resolution blue intensity profiles

    Science.gov (United States)

    Babst, Flurin; Wright, William; Szejner, Paul; Wells, Leon; Belmecheri, Soumaya; Monson, Russell

    2016-04-01

    Rapidly rising evaporative demand threatens forests in semi-arid areas around the world, but the timing of stem growth response to drought is often coarsely known. This is partly due to a shortage of sub-annual growth records, particularly outside the Mediterranean region where most intra-annual density fluctuation (IADF) chronologies are based. We anticipate that an automated, cost-effective, and easily implementable method to characterize IADFs could foster more widespread development of sub-annual chronologies. Here, we applied a peak detection algorithm to fine-spatial resolution blue intensity (BI) profiles of Ponderosa pine tree rings from two sites located in neighboring mountain ranges in southern Arizona (~300 m elevation difference). This automated procedure proved reliable to isolate and characterize IADFs, thus offering an efficient and objective alternative to visual identification. Out of seven investigated BI parameters, peak height, width, and area showed satisfactory chronology statistics. We assessed the response of these BI and radial growth parameters to six monthly-resolved climate variables and to the onset date of the North American summer monsoon (NAM). The NAM is an atmospheric mode that provides a clear time marker for the termination of a pre-summer drought period (May-June) causing regular IADFs in trees growing near the dry margin of their distribution range. We observed divergent water limitation at the two sites, despite comparable site characteristics. Radial growth at the lower-elevation site depended mainly on winter precipitation, whereas the higher site relied on spring and monsoon precipitation. The pre-summer drought period indeed promoted IADFs in early ring portions at both sites. Yet, IADFs at the higher site were only formed, if spring was sufficiently humid to assume enough radial growth. Late-position IADFs were caused by a weak monsoon and additionally promoted by favorable conditions towards the end of the growing

  13. Validation of improved Multi-Mode model for density, temperature and toroidal rotation profiles using PTRANSP simulations

    Science.gov (United States)

    Luo, L.; Bateman, G.; Kritz, A. H.; Pankin, A. Y.; Rafiq, T.; McCune, D. C.; Budny, R. V.

    2010-11-01

    Advances in the Multi-Mode model include an improved Weiland model for the ITG and TEM modes [1] and a new model for the drift resistive inertial ballooning modes (DRIBM) [2]. Advances in the PTRANSP code include an improved algorithm for the particle density evolution. Validation studies are carried out for the improved Multi-Mode model using PTRANSP simulations. In order to allow tight coupling with stiff transport models, all of the transport equations for main ion and impurity density profiles as well as electron temperature, ion temperature and toroidal angular rotation profiles are advanced simultaneously by the PTRANSP solver. The Plasma State connects the new solver to the rest of PTRANSP. The solver uses several techniques to control numerical stability. Simulation results for density, temperature and rotation frequency profiles are compared with experimental data for L-mode and H-mode discharges. [4pt] [1] J.Weiland et al., Nucl. Fusion 49 (2009) 965933; F.D. Halpern et al., Phys. Plasmas 15 (2008) 065033 [2] T. Rafiq et al., to appear in Phys. Plasmas (2010)

  14. Numerical Simulation of Hot Accretion Flows (I): A Large Radial Dynamical Range and the Density Profile of Accretion Flow

    CERN Document Server

    Yuan, Feng; Bu, Defu

    2012-01-01

    Numerical simulations of hot accretion flow have shown that the mass accretion rate decreases with decreasing radius; consequently the density profile of accretion flow becomes flatter compared to the case of a constant accretion rate. This result has important theoretical and observational implications. However, because of technical difficulties, the radial dynamic range in almost all previous simulations usually spans at most two orders of magnitude. This small dynamical range, combined with the effects of boundary conditions, makes the simulation results suspectable. Especially, the radial profiles of density and accretion rate may not be precise enough to be used to compare with observations. In this paper we present a "two-zone" approach to expand the radial dynamical range from two to four orders of magnitude. We confirm previous results and find that from $r_s$ to $ 10^4r_s$ the radial profiles of accretion rate and density can be well described by $\\dot{M}(r)\\propto r^s$ and $\\rho\\propto r^{-p}$. The ...

  15. A long-term study on the deletion criterion of questionable electron density profiles caused by ionospheric irregularities - COSMIC radio occultation technique

    Science.gov (United States)

    Uma, G.; Brahmanandam, P. S.; Chu, Y. H.

    2016-06-01

    The crucial assumption made in the retrieval of radio-occultated atmospheric parameters is the spherical symmetry of the atmospheric refractive index, which implies that no horizontal gradient of the refractive index exists along the spherical shell. Nevertheless, the presence of density irregularities will lead to scintillation and multipath effects that often create highly fluctuating and random electron density profiles. In this study, it is proposed a reliable data quality control (QC) approach to remove questionable electron density profiles (due to the presence of ionospheric irregularities) retrieved using the COSMIC radio occultation (RO) technique based on two parameters, namely, the gradient and fluctuation of the topside density profile. Statistics of seven years density profiles (July 2006-May 2013) are presented by determining the aforementioned parameters for every density profile. The main advantage of this data QC is that it uses COSMIC RO electron density profiles retrieved from the slant total electron content (TEC) that is estimated from the excess phases of the GPS L1 and L2 frequencies only to delete the questionable profiles, instead of relying on any model and other observations. A systematic criterion has been developed based on the statistics to relinquish the so-called questionable density profiles. The computed gradients and fluctuations of the topside ionosphere electron density profiles have shown a few important features including, solar activity dependency and pronounced variations in between around +40° and -40° latitudes. After the removal of questionable profiles, both peak densities and heights of the ionosphere F layer are presented globally in different seasons of years during 2007 and 2012 that revealed several important features.

  16. High-Latitude Topside Ionospheric Vertical Electron-Density-Profile Changes in Response to Large Magnetic Storms

    Science.gov (United States)

    Benson, Robert F.; Fainberg, Joseph; Osherovich, Vladimir A.; Truhlik, Vladimir; Wang, Yongli; Bilitza, Dieter; Fung, Shing F.

    2015-01-01

    Large magnetic-storm induced changes have been detected in high-latitude topside vertical electron-density profiles Ne(h). The investigation was based on the large database of topside Ne(h) profiles and digital topside ionograms from the International Satellites for Ionospheric Studies (ISIS) program available from the NASA Space Physics Data Facility (SPDF) at http://spdf.gsfc.nasa.gov/isis/isis-status.html. This large database enabled Ne(h) profiles to be obtained when an ISIS satellite passed through nearly the same region of space before, during, and after a major magnetic storm. A major goal was to relate the magnetic-storm induced high-latitude Ne(h) profile changes to solar-wind parameters. Thus an additional data constraint was to consider only storms where solar-wind data were available from the NASA/SPDF OMNIWeb database. Ten large magnetic storms (with Dst less than -100 nT) were identified that satisfied both the Ne(h) profile and the solar-wind data constraints. During five of these storms topside ionospheric Ne(h) profiles were available in the high-latitude northern hemisphere and during the other five storms similar ionospheric data were available in the southern hemisphere. Large Ne(h) changes were observed during each one of these storms. Our concentration in this paper is on the northern hemisphere. The data coverage was best for the northern-hemisphere winter. Here Ne(h) profile enhancements were always observed when the magnetic local time (MLT) was between 00 and 03 and Ne(h) profile depletions were always observed between 08 and 10 MLT. The observed Ne(h) deviations were compared with solar-wind parameters, with appropriate time shifts, for four storms.

  17. Cross-correlation Weak Lensing of SDSS galaxy Clusters II: Cluster Density Profiles and the Mass--Richness Relation

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, David E.; Sheldon, Erin S.; Wechsler, Risa H.; Rozo, Eduardo; Koester, Benjamin P.; Frieman, Joshua A.; McKay, Timothy A.; Evrard, August E.; Becker, Matthew; Annis, James

    2007-09-28

    We interpret and model the statistical weak lensing measurements around 130,000 groups and clusters of galaxies in the Sloan Digital Sky Survey presented by Sheldon et al. (2007). We present non-parametric inversions of the 2D shear profiles to the mean 3D cluster density and mass profiles in bins of both optical richness and cluster i-band luminosity. Since the mean cluster density profile is proportional to the cluster-mass correlation function, the mean profile is spherically symmetric by the assumptions of large-scale homogeneity and isotropy. We correct the inferred 3D profiles for systematic effects, including non-linear shear and the fact that cluster halos are not all precisely centered on their brightest galaxies. We also model the measured cluster shear profile as a sum of contributions from the brightest central galaxy, the cluster dark matter halo, and neighboring halos. We infer the relations between mean cluster virial mass and optical richness and luminosity over two orders of magnitude in cluster mass; the virial mass at fixed richness or luminosity is determined with a precision of {approx} 13% including both statistical and systematic errors. We also constrain the halo concentration parameter and halo bias as a function of cluster mass; both are in good agreement with predictions from N-body simulations of LCDM models. The methods employed here will be applicable to deeper, wide-area optical surveys that aim to constrain the nature of the dark energy, such as the Dark Energy Survey, the Large Synoptic Survey Telescope and space-based surveys.

  18. Residual magnetic field profiles and their current density profiles of coated conductors for fast and slow cut-off current operations

    Energy Technology Data Exchange (ETDEWEB)

    Sun, J.; Taillouli, M.; Hamabe, M.; Watanabe, H.; Chikumoto, N.; Yamaguchi, S. [Chubu University, Kasugai, Aichi (Japan); Shyshkin, O. [V. N. Karazin Kharkiv National University, Kharkov (Ukraine)

    2015-03-15

    Coated conductor is an important candidate for power cable applications due to its high current density. Even for DC power cable transmission, we must study the transport properties of HTS tapes after slow and fast discharge. In order to evaluate relation of the magnetic field with applied current we developed a scanning magnetic field measurements system by employing a Hall probe. This work presents the measurements of the magnetic fields above a coated conductor by varying applied current pattern. In the work, a transport current of 100 A, less than the critical current, is applied to YBCO coated conductor. We measured the residual magnetic field distributions after cut off the transport current with slow and fast operations. The results show differences of the magnetic field profiles and the corresponding current profiles by an inverse solution from the magnetic field measurement between these two operations because of the hysteresis of coated conductor excited by the transport current.

  19. Space charge profiles in low density polyethylene samples containing a permittivity/conductivity gradient

    DEFF Research Database (Denmark)

    Bambery, K.R.; Fleming, R.J.; Holbøll, Joachim

    2001-01-01

    .5×107 V m-1. Current density was also measured as a function of temperature and field. Space charge due exclusively to the temperature gradient was detected, with density of order 0.01 C m-3. The activation energy associated with the transport of electrons through the bulk was calculated as 0.09 e...

  20. THE MASS PROFILE AND SHAPE OF BARS IN THE SPITZER SURVEY OF STELLAR STRUCTURE IN GALAXIES (S{sup 4}G): SEARCH FOR AN AGE INDICATOR FOR BARS

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Taehyun; Lee, Myung Gyoon [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Sheth, Kartik; Muñoz-Mateos, Juan-Carlos [National Radio Astronomy Observatory/NAASC, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Gadotti, Dimitri A. [European Southern Observatory, Casilla 19001, Santiago 19 (Chile); Zaritsky, Dennis [University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Elmegreen, Bruce G. [IBM Research Division, T. J. Watson Research Center, Yorktown Heights, NY 10598 (United States); Athanassoula, E.; Bosma, Albert [Aix Marseille Université, CNRS, LAM (Laboratoire d' Astrophysique de Marseille) UMR 7326, 13388 Marseille (France); Holwerda, Benne [European Space Agency, ESTEC, Keplerlaan 1, 2200-AG, Noordwijk (Netherlands); Ho, Luis C. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Comerón, Sébastien; Laurikainen, Eija; Salo, Heikki [Division of Astronomy, Department of Physical Sciences, University of Oulu, Oulu, FIN-90014 (Finland); Knapen, Johan H.; Erroz-Ferrer, Santiago [Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain); Hinz, Joannah L. [MMTO, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Buta, Ronald J. [Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487 (United States); Kim, Minjin [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Madore, Barry F. [The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); and others

    2015-01-20

    We have measured the radial light profiles and global shapes of bars using two-dimensional 3.6 μm image decompositions for 144 face-on barred galaxies from the Spitzer Survey of Stellar Structure in Galaxies. The bar surface brightness profile is correlated with the stellar mass and bulge-to-total (B/T) ratio of their host galaxies. Bars in massive and bulge-dominated galaxies (B/T > 0.2) show a flat profile, while bars in less massive, disk-dominated galaxies (B/T ∼ 0) show an exponential, disk-like profile with a wider spread in the radial profile than in the bulge-dominated galaxies. The global two-dimensional shapes of bars, however, are rectangular/boxy, independent of the bulge or disk properties. We speculate that because bars are formed out of disks, bars initially have an exponential (disk-like) profile that evolves over time, trapping more disk stars to boxy bar orbits. This leads bars to become stronger and have flatter profiles. The narrow spread of bar radial profiles in more massive disks suggests that these bars formed earlier (z > 1), while the disk-like profiles and a larger spread in the radial profile in less massive systems imply a later and more gradual evolution, consistent with the cosmological evolution of bars inferred from observational studies. Therefore, we expect that the flatness of the bar profile can be used as a dynamical age indicator of the bar to measure the time elapsed since the bar formation. We argue that cosmic gas accretion is required to explain our results on bar profile and the presence of gas within the bar region.

  1. The Mass Profile and Shape of Bars in the Spitzer Survey of Stellar Structure in Galaxies (S4G): Search for an Age Indicator for Bars

    CERN Document Server

    Kim, Taehyun; Gadotti, Dimitri A; Lee, Myung Gyoon; Zaritsky, Dennis; Elmegreen, Bruce G; Athanassoula, E; Bosma, Albert; Holwerda, Benne; Ho, Luis C; Comerón, Sébastien; Knapen, Johan H; Hinz, Joannah L; Muñoz-Mateos, Juan-Carlos; Erroz-Ferrer, Santiago; Buta, Ronald J; Kim, Minjin; Laurikainen, Eija; Salo, Heikki; Madore, Barry F; Laine, Jarkko; Menéndez-Delmestre, Karín; Regan, Michael W; de Swardt, Bonita; de Paz, Armando Gil; Seibert, Mark; Mizusawa, Trisha

    2014-01-01

    We have measured the radial light profiles and global shapes of bars using two-dimensional 3.6 $\\mu m $ image decompositions for 144 face-on barred galaxies from the Spitzer Survey of Stellar Structure in Galaxies (S4G). The bar surface brightness profile is correlated with the stellar mass and bulge-to-total (B/T) ratio of their host galaxies. Bars in massive and bulge-dominated galaxies (B/T$>$0.2) show a flat profile, while bars in less massive, disk-dominated galaxies (B/T$\\sim$0) show an exponential, disk-like profile with a wider spread in the radial profile than in the bulge-dominated galaxies. The global two-dimensional shapes of bars, however, are rectangular/boxy, independent of the bulge or disk properties. We speculate that because bars are formed out of disk, bars initially have an exponential (disk-like) profile which evolves over time, trapping more stars into the boxy bar orbits. This leads bars to become stronger and have flatter profiles. The narrow spread of bar radial profiles in more mass...

  2. Effects of Shewanella putrefaciens on innate immunity and cytokine expression profile upon high stocking density of gilthead seabream specimens.

    Science.gov (United States)

    Cordero, Héctor; Morcillo, Patricia; Meseguer, José; Cuesta, Alberto; Esteban, M Ángeles

    2016-04-01

    High stocking density increases the number of emerging diseases triggering economic losses worldwide. Probiotics provide an effective and natural solution for preventing some diseases through an improvement of innate immune system among others. In the present work dietary administration of the probiotic Shewanella putrefaciens (known as Pdp11) was evaluated under stress by high stocking density after 2 and 4 weeks of administration to gilthead seabream (Sparus aurata) specimens. Results showed an increase in cellular peroxidase and respiratory burst activity as well as a modulation of cytokine profile when Pdp11 was administered to fish reared at high stocking density. Overall, our results showed how Pdp11 is not only able to improve to some extent the cellular and humoral immunity but also to increase the gene expression profile of pro-inflammatory cytokines such as il1b or il6 in response to high stocking density in gilthead seabream. These findings may support the potential use of this probiotic as functional feed against stress in fish farms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Broadening of the Spectral Atomic Lines Analysis in High Density Argon Corona Plasma by Using Voigt Profile

    Science.gov (United States)

    Nur, M.; Bonifaci, N.; Denat, A.; Atrazhev, V. M.

    2015-06-01

    Studies of spectrum emission from high density argon plasma corona has been done. The analysis of the boardening of spectral atomic lines of Ar-I profile has been curried out by using an empirical approximation based on a Voigt profile. Full-width at half-maximum (FWHM) of the spectral-lines of 763.5 nm has been determined from atmospheric pressure until liquid state. The study liquid argon was curried out in a variation of temperature from K to 151.2 K and hydrostatics pressure from 2.1 MPa to 6.4 MPa. These pressure gives the densities N∞ (i.e. density very far from ionization zone) a variation from 1.08 1022 to 2.11 1022 cm-3. FWHM of Voigt approximation (Wv) of the line 763,5 nm of 'Ar I for: the emission lamp very low pressure (Wv = 0,160 nm) and our corona discharge at a pressure of MPa (Wv = 0,67 nm) and at a pressure of 9,5 MPa (Wv = 1,16 nm). In gas, corona plasma has been generated from 0.1 MPa to 9.5 MPa. We found that the broadening spectral line increase by increasing densities both for. the spectral-lines of 763.5 nm and 696.5 nm. We concluded that broadening of spectrum cause of Van der Waals force.

  4. The dynamics of straight vortex filaments in a Bose-Einstein condensate with a Gaussian density profile

    CERN Document Server

    Ruban, V P

    2016-01-01

    The dynamics of interacting quantized vortex filaments in a rotating trapped Bose-Einstein condensate, which is in the Thomas-Fermi regime at zero temperature and described by the Gross-Pitaevskii equation, is considered in the hydrodynamical "anelastic" approximation. In the presence of a smoothly inhomogeneous array of filaments (vortex lattice), a non-canonical Hamiltonian equation of motion is derived for the macroscopically averaged vorticity, with taking into account the spatial non-uniformity of the equilibrium condensate density determined by the trap potential. A minimum of the corresponding Hamiltonian describes a static configuration of deformed vortex lattice against a given density background. The minimum condition is reduced to a vector nonlinear partial differential equation of the second order, for which some approximate and exact solutions are found. It is shown that if the condensate density has an anisotropic Gaussian profile then equation of motion for the averaged vorticity admits solutio...

  5. Model-based Optimization and Feedback Control of the Current Density Profile Evolution in NSTX-U

    Science.gov (United States)

    Ilhan, Zeki Okan

    Nuclear fusion research is a highly challenging, multidisciplinary field seeking contributions from both plasma physics and multiple engineering areas. As an application of plasma control engineering, this dissertation mainly explores methods to control the current density profile evolution within the National Spherical Torus eXperiment-Upgrade (NSTX-U), which is a substantial upgrade based on the NSTX device, which is located in Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ. Active control of the toroidal current density profile is among those plasma control milestones that the NSTX-U program must achieve to realize its next-step operational goals, which are characterized by high-performance, long-pulse, MHD-stable plasma operation with neutral beam heating. Therefore, the aim of this work is to develop model-based, feedforward and feedback controllers that can enable time regulation of the current density profile in NSTX-U by actuating the total plasma current, electron density, and the powers of the individual neutral beam injectors. Motivated by the coupled, nonlinear, multivariable, distributed-parameter plasma dynamics, the first step towards control design is the development of a physics-based, control-oriented model for the current profile evolution in NSTX-U in response to non-inductive current drives and heating systems. Numerical simulations of the proposed control-oriented model show qualitative agreement with the high-fidelity physics code TRANSP. The next step is to utilize the proposed control-oriented model to design an open-loop actuator trajectory optimizer. Given a desired operating state, the optimizer produces the actuator trajectories that can steer the plasma to such state. The objective of the feedforward control design is to provide a more systematic approach to advanced scenario planning in NSTX-U since the development of such scenarios is conventionally carried out experimentally by modifying the tokamak's actuator

  6. Retrieval of effective leaf area index (LAIe) and leaf area density (LAD) profile at individual tree level using high density multi-return airborne LiDAR

    Science.gov (United States)

    Lin, Yi; West, Geoff

    2016-08-01

    As an important canopy structure indicator, leaf area index (LAI) proved to be of considerable implications for forest ecosystem and ecological studies, and efficient techniques for accurate LAI acquisitions have long been highlighted. Airborne light detection and ranging (LiDAR), often termed as airborne laser scanning (ALS), once was extensively investigated for this task but showed limited performance due to its low sampling density. Now, ALS systems exhibit more competing capacities such as high density and multi-return sampling, and hence, people began to ask the questions like-"can ALS now work better on the task of LAI prediction?" As a re-examination, this study investigated the feasibility of LAI retrievals at the individual tree level based on high density and multi-return ALS, by directly considering the vertical distributions of laser points lying within each tree crown instead of by proposing feature variables such as quantiles involving laser point distribution modes at the plot level. The examination was operated in the case of four tree species (i.e. Picea abies, Pinus sylvestris, Populus tremula and Quercus robur) in a mixed forest, with their LAI-related reference data collected by using static terrestrial laser scanning (TLS). In light of the differences between ALS- and TLS-based LAI characterizations, the methods of voxelization of 3D scattered laser points, effective LAI (LAIe) that does not distinguish branches from canopies and unified cumulative LAI (ucLAI) that is often used to characterize the vertical profiles of crown leaf area densities (LADs) was used; then, the relationships between the ALS- and TLS-derived LAIes were determined, and so did ucLAIs. Tests indicated that the tree-level LAIes for the four tree species can be estimated based on the used airborne LiDAR (R2 = 0.07, 0.26, 0.43 and 0.21, respectively) and their ucLAIs can also be derived. Overall, this study has validated the usage of the contemporary high density multi

  7. Space charge profiles in low density polyethylene samples containing a permittivity/conductivity gradient

    DEFF Research Database (Denmark)

    Bambery, K.R.; Fleming, R.J.; Holbøll, Joachim

    2001-01-01

    Laser induced pressure pulse space charge measurements were made on 1.5 mm thick plaques of high purity low density polyethylene equipped with vacuum-evaporated aluminium electrodes. Temperature differences up to 20 °C were maintained across the samples, which were subjected to dc fields up to 1.......5×107 V m-1. Current density was also measured as a function of temperature and field. Space charge due exclusively to the temperature gradient was detected, with density of order 0.01 C m-3. The activation energy associated with the transport of electrons through the bulk was calculated as 0.09 e...

  8. Rapidity Profile of the Initial Energy Density in Heavy-Ion Collisions

    CERN Document Server

    Ozonder, Sener

    2013-01-01

    The rapidity dependence of the initial energy density in heavy-ion collisions is calculated from a three-dimensional McLerran-Venugopalan model (3dMVn) introduced by Lam and Mahlon. This model is infrared safe since global color neutrality is enforced. In this non-boost-invariant framework, the nuclei have non-zero thickness in the longitudinal direction. This results in Bjorken-x dependent unintegrated gluon distribution functions which lead to a rapidity-dependent initial energy density after the collision. The initial energy density and its rapidity dependence are important initial conditions for the quark gluon plasma and its hydrodynamic evolution.

  9. Simultaneous monitoring of protein adsorption at the solid-liquid interface from sessile solution droplets by ellipsometry and axisymmetric drop shape analysis by profile

    NARCIS (Netherlands)

    Wormeester, H; Busscher, HK

    1999-01-01

    In this paper two in situ techniques are combined to simultaneously examine protein adsorption at the solid-liquid interface from sessile solution droplets. With axisymmetric drop shape analysis by profile (ADSA-P) the change in solid-liquid interfacial tension is determined, while ellipsometry is e

  10. Simultaneous monitoring of protein adsorption at the solid–liquid interface from sessile solution droplets by ellipsometry and axisymmetric drop shape analysis by profile

    NARCIS (Netherlands)

    Noordmans, Jaap; Wormeester, Herbert; Busscher, Henk J.

    1999-01-01

    In this paper two in situ techniques are combined to simultaneously examine protein adsorption at the solid–liquid interface from sessile solution droplets. With axisymmetric drop shape analysis by profile (ADSA-P) the change in solid–liquid interfacial tension is determined, while ellipsometry is e

  11. THE INFLUENCE OF DROPLET VOLUME AND CONTACT-ANGLE ON LIQUID SURFACE-TENSION MEASUREMENTS BY AXISYMMETRICAL DROP SHAPE ANALYSIS-PROFILE (ADSA-P)

    NARCIS (Netherlands)

    BUSSCHER, HJ

    1991-01-01

    The axisymmetric drop shape analysis-profile (ADSA-P) technique was evaluated with respect to the influence of contact angle and droplet volume. The system was implemented on our standard contact angle measuring apparatus employing a Vidicon video camera and a 512 x 256 pixels framegrabber. For cali

  12. Topside-plasmasphere electron density profiles model by using AIS ionosonde measurements and calibrates GPS TEC data

    Science.gov (United States)

    Cesaroni, Claudio; Scotto, Carlo; Ippolito, Alessandro; Ciraolo, Luigi

    2013-04-01

    The Upper Atmosphere Physics group at INGV (Istituto Nazionale di Geofisica e Vulcanologia) developed Autoscala, a computer program for automatic scaling of the critical frequency foF2 and other ionospheric parameters derived from ionograms. Autoscala includes a routine that automatically estimates the electron density profile below F layer peak height hmF2, by adjusting the parameters of a model according to the recorded ionogram [Scotto (2009)]. By integrating this profile we can estimate bottom-side total electron content (bTEC). By means of a calibration technique [Ciraolo et al. (2007)], we are able to obtain calibrated vertical TEC (vTEC) values from GPS measurements over a receiver station. This method permits to estimate biases of the received signal due to transmitter-receiver hardware configuration. These biases must be eliminated from the GPS data in order to calibrate the experimental slant total electron content (sTEC) along the satellite-receiver line-of-sight (LoS). The difference between vTEC and bottom-side TEC (bTEC) permits to evaluate electron content of the topside ionospheric region (tTEC). Starting from tTEC, bottom-side parameters (foF2, hmF2, scale height at hmF2) obtained by ionosonde and O+ - H+ transition level, we can solve a system of equations based on different ionospheric profiler (Chapman, sech-squared and exponential) the solution of which provides ion scale height [Stankov et al. (2003)]. This last factor is sufficient to establish the vertical distribution of electrons in topside and plasmasphere regions. Obtained vertical profiles could be used to develop a new model for real time estimation of TEC and topside electron density distribution. References: Scotto, C. (2009). Electron density profile calculation technique for Autoscala ionogram analysis. Advances in Space Research, 44(6), 756-766. doi:10.1016/j.asr.2009.04.037 Ciraolo, L., et al. "Calibration errors on experimental slant total electron content (TEC) determined with

  13. Large Deviation of the Density Profile in the Steady State of the Open Symmetric Simple Exclusion Process

    Science.gov (United States)

    Derrida, B.; Lebowitz, J. L.; Speer, E. R.

    2002-05-01

    We consider an open one dimensional lattice gas on sites i=1,..., N, with particles jumping independently with rate 1 to neighboring interior empty sites, the simple symmetric exclusion process. The particle fluxes at the left and right boundaries, corresponding to exchanges with reservoirs at different chemical potentials, create a stationary nonequilibrium state (SNS) with a steady flux of particles through the system. The mean density profile in this state, which is linear, describes the typical behavior of a macroscopic system, i.e., this profile occurs with probability 1 when N→∞. The probability of microscopic configurations corresponding to some other profile ρ( x), x= i/ N, has the asymptotic form exp[- N F({ ρ})]; F is the large deviation functional. In contrast to equilibrium systems, for which F eq({ ρ}) is just the integral of the appropriately normalized local free energy density, the F we find here for the nonequilibrium system is a nonlocal function of ρ. This gives rise to the long range correlations in the SNS predicted by fluctuating hydrodynamics and suggests similar non-local behavior of F in general SNS, where the long range correlations have been observed experimentally.

  14. In depth fusion flame spreading with a deuterium-tritium plane fuel density profile for plasma block ignition

    Institute of Scientific and Technical Information of China (English)

    B.Malekynia; S.S.Razavipour

    2012-01-01

    Solid-state fuel ignition was given by Chu and Bobin according to the hydrodynamic theory at x =0 qualitatively.A high threshold energy flux density,i.e.,E* =4.3 x 1012 J/m2,has been reached.Recently,fast ignition by employing clean petawatt-picosecond laser pulses was performed.The anomalous phenomena were observed to be based on suppression of prepulses.The accelerated plasma block was used to ignite deuterium-tritium fuel at solid-state density.The detailed analysis of the thermonuclear wave propagation was investigated.Also the fusion conditions at x ≠ 0 layers were clarified by exactly solving hydrodynamic equations for plasma block ignition.In this paper,the applied physical mechanisms are determined for nonlinear force laser driven plasma blocks,thermonuclear reaction,heat transfer,electron-ion equilibration,stopping power of alpha particles,bremsstrahlung,expansion,density dependence,and fluid dynamics.New ignition conditions may be obtained by using temperature equations,including thc dcnsity profile that is obtained by the continuity equation and expansion velocity.The density is only a function of x and independent of time.The ignition energy flux density,E*t,for the x ≠ 0 layers is 1.95 × 1012 J/m2.Thus threshold ignition energy in comparison with that at x =0 layers would be reduced to less than 50 percent.

  15. RELATIONSHIPS BETWEEN ANATOMICAL FEATURES AND INTRA-RING WOOD DENSITY PROFILES IN Gmelina arborea APPLYING X-RAY DENSITOMETRY

    Directory of Open Access Journals (Sweden)

    Mario Tomazelo-Filho

    2007-12-01

    Full Text Available Four annual tree-rings (2 of juvenile wood and 2 of mature wood were sampled from fast-growth plantations ofGmelina arborea in two climatic conditions (dry and wet tropical in Costa Rica. Each annual tree-ring was divided in equal parts ina radial direction. For each part, X-ray density as well as vessel percentage, length and width fiber, cell wall thickness and lumendiameter were measured. Wood density and profile patterns of cell dimension demonstrated inconsistency between juvenile andmature wood and climatic conditions. The Pearson correlation matrix showed that intra-ring wood density was positively correlatedwith the cell wall thickness and negatively correlated with vessel percentage, fiber length, lumen diameter and width. The forwardstepwise regressions determined that: (i intra-ring wood density variation could be predicted from 76 to 96% for anatomicalvariation; (ii cell wall thickness was the most important anatomical feature to produce intra-ring wood density variation and (iii thevessel percentage, fiber length, lumen diameter and width were the second most statically significant characteristics to intra-ring wooddensity, however, with low participation of the determination coefficient of stepwise regressions.

  16. Mars Ozone Absorption Line Shapes from Infrared Heterodyne Spectra Applied to GCM-Predicted Ozone Profiles and to MEX/SPICAM Column Retrievals

    Science.gov (United States)

    Fast, Kelly E.; Kostiuk, T.; Annen, J.; Hewagama, T.; Delgado, J.; Livengood, T. A.; Lefevre, F.

    2008-01-01

    We present the application of infrared heterodyne line shapes of ozone on Mars to those produced by radiative transfer modeling of ozone profiles predicted by general circulation models (GCM), and to contemporaneous column abundances measured by Mars Express SPICAM. Ozone is an important tracer of photochemistry Mars' atmosphere, serving as an observable with which to test predictions of photochemistry-coupled GCMs. Infrared heterodyne spectroscopy at 9.5 microns with spectral resolving power >1,000,000 is the only technique that can directly measure fully-resolved line shapes of Martian ozone features from the surface of the Earth. Measurements were made with Goddard Space Flight Center's Heterodyne instrument for Planetary Wind And Composition (HIPWAC) at the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii on February 21-24 2008 UT at Ls=35deg on or near the MEX orbital path. The HIPWAC observations were used to test GCM predictions. For example, a GCM-generated ozone profile for 60degN 112degW was scaled so that a radiative transfer calculation of its absorption line shape matched an observed HIPWAC absorption feature at the same areographic position, local time, and season. The RMS deviation of the model from the data was slightly smaller for the GCM-generated profile than for a line shape produced by a constant-with-height profile, even though the total column abundances were the same, showing potential for testing and constraining GCM ozone-profiles. The resulting ozone column abundance from matching the model to the HIPWAC line shape was 60% higher than that observed by SPICAM at the same areographic position one day earlier and 2.5 hours earlier in local time. This could be due to day-to-day, diurnal, or north polar region variability, or to measurement sensitivity to the ozone column and its distribution, and these possibilities will be explored. This work was supported by NASA's Planetary Astronomy Program.

  17. Mars Ozone Absorption Line Shapes from Infrared Heterodyne Spectra Applied to GCM-Predicted Ozone Profiles and to MEX/SPICAM Column Retrievals

    Science.gov (United States)

    Fast, Kelly E.; Kostiuk, T.; Annen, J.; Hewagama, T.; Delgado, J.; Livengood, T. A.; Lefevre, F.

    2008-01-01

    We present the application of infrared heterodyne line shapes of ozone on Mars to those produced by radiative transfer modeling of ozone profiles predicted by general circulation models (GCM), and to contemporaneous column abundances measured by Mars Express SPICAM. Ozone is an important tracer of photochemistry Mars' atmosphere, serving as an observable with which to test predictions of photochemistry-coupled GCMs. Infrared heterodyne spectroscopy at 9.5 microns with spectral resolving power >1,000,000 is the only technique that can directly measure fully-resolved line shapes of Martian ozone features from the surface of the Earth. Measurements were made with Goddard Space Flight Center's Heterodyne instrument for Planetary Wind And Composition (HIPWAC) at the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii on February 21-24 2008 UT at Ls=35deg on or near the MEX orbital path. The HIPWAC observations were used to test GCM predictions. For example, a GCM-generated ozone profile for 60degN 112degW was scaled so that a radiative transfer calculation of its absorption line shape matched an observed HIPWAC absorption feature at the same areographic position, local time, and season. The RMS deviation of the model from the data was slightly smaller for the GCM-generated profile than for a line shape produced by a constant-with-height profile, even though the total column abundances were the same, showing potential for testing and constraining GCM ozone-profiles. The resulting ozone column abundance from matching the model to the HIPWAC line shape was 60% higher than that observed by SPICAM at the same areographic position one day earlier and 2.5 hours earlier in local time. This could be due to day-to-day, diurnal, or north polar region variability, or to measurement sensitivity to the ozone column and its distribution, and these possibilities will be explored. This work was supported by NASA's Planetary Astronomy Program.

  18. Effect of voltage shape of electrical power supply on radiation and density of a cold atmospheric argon plasma jet

    OpenAIRE

    F. Sohbatzadeh; Bagheri, M; S. Motallebi

    2017-01-01

    In this work, we investigated generating argon cold plasma jet at atmospheric pressure based on dielectric barrier discharge configuration using three electrical power supplies of sinusoidal, pulsed and saw tooth high voltage shapes at 8 KHZ. At first; we describe the electronic circuit features for generating high voltage (HV) wave forms including saw tooth, sinusoidal and pulsed forms. Then, we consider the effect of voltage shape on the electrical breakdown. Relative concentrations of chem...

  19. Determination of global plasmaspheric electron density profile by tomographic approach using omega signals and ray tracing

    Science.gov (United States)

    Kimura, I.; Kasahara, Y.; Oya, H.

    2001-07-01

    It has been necessary requirements to determine the global electron density distribution in the plasmasphere with time resolutions, of less than a day. We have provided solutions to this requirement using the wave normal directions, delay time of Omega signals and the in situ electron density observed on-board the Japanese satellite Akebono (Sawada et al., Journal of Geophysical Research 98(11) (1993) 267, Kimura et al., Advance Space Research 15(2) (1995) 103, Advance Space Research 18(6) (1996) 279, Journal of Atmospheric and Solar-Terrestrial Physics 59 (1997) 1569). The present paper is intended to review our earlier studies.

  20. A simple analysis of halo density profiles using gravitational lensing time delays

    OpenAIRE

    2006-01-01

    Gravitational lensing time delays depend upon the Hubble constant and the density distribution of the lensing galaxies. This allows one to either model the lens and estimate the Hubble constant, or to use a prior on the Hubble constant from other studies and investigate what the preferred density distribution is. Some studies have required compact dark matter halos (constant M/L ratio) in order to reconcile gravitational lenses with the HST/WMAP value of the Hubble constant (72 +/- 8 km/s /Mp...

  1. Cross-correlation Weak Lensing of SDSS galaxy Clusters II: Cluster Density Profiles and the Mass--Richness Relation

    CERN Document Server

    Johnston, David E; Wechsler, Risa H; Rozo, Eduardo; Koester, Benjamin P; Frieman, Joshua A; McKay, Timothy A; Evrard, August E; Becker, Matthew R; Annis, James

    2007-01-01

    We interpret and model the statistical weak lensing measurements around 130,000 groups and clusters of galaxies in the Sloan Digital Sky Survey presented by Sheldon et al. 2007 (Paper I). We present non-parametric inversions of the 2D shear profiles to the mean 3D cluster density and mass profiles in bins of both optical richness and cluster i-band luminosity. We correct the inferred 3D profiles for systematic effects, including non-linear shear and the fact that cluster halos are not all precisely centered on their brightest galaxies. We also model the measured cluster shear profile as a sum of contributions from the brightest central galaxy, the cluster dark matter halo, and neighboring halos. We infer the relations between mean cluster virial mass and optical richness and luminosity over two orders of magnitude in cluster mass; the virial mass at fixed richness or luminosity is determined with a precision of 13% including both statistical and systematic errors. We also constrain the halo concentration para...

  2. Gene expression profiling in human peripheral blood mononuclear cells using high-density filter-based cDNA microarrays.

    Science.gov (United States)

    Walker, J; Rigley, K

    2000-05-26

    Microarray technology has provided the ability to analyse the expression profiles for thousands of genes in parallel. The need for highly specialised equipment to use certain types of microarrays has restricted the application of this technology to a small number of dedicated laboratories. High-density filter-based cDNA microarrays provide a low-cost option for performing high-throughput gene expression analysis. We have used a model system in which filter-based cDNA microarrays representing over 4000 known human genes were used to monitor the kinetics of gene expression in human peripheral blood mononuclear cells (PBMCs) stimulated with phytohaemagluttinin (PHA). Using software-based cluster analysis, we identified 104 genes that altered in expression levels in response to PHA stimulation of PBMCs and showed that there was a considerable overlap between genes with similar temporal expression profiles and similar functional roles. Comparison of microarray quantitation with quantitative PCR showed almost identical expression profiles for a number of genes. Coupled with the fact that our findings are in agreement with a large number of independent observations, we conclude that the use of filter-based cDNA microarrays is a valid and accurate method for high-throughput gene expression profiling.

  3. 3D bone mineral density distribution and shape reconstruction of the proximal femur from a single simulated DXA image: an in vitro study

    Science.gov (United States)

    Whitmarsh, Tristan; Humbert, Ludovic; De Craene, Mathieu; del Río Barquero, Luis M.; Fritscher, Karl; Schubert, Rainer; Eckstein, Felix; Link, Thomas; Frangi, Alejandro F.

    2010-03-01

    Area Bone Mineral Density (aBMD) measured by Dual-energy X-ray Absorptiometry (DXA) is an established criterion in the evaluation of hip fracture risk. The evaluation from these planar images, however, is limited to 2D while it has been shown that proper 3D assessment of both the shape and the Bone Mineral Density (BMD) distribution improves the fracture risk estimation. In this work we present a method to reconstruct both the 3D bone shape and 3D BMD distribution of the proximal femur from a single DXA image. A statistical model of shape and a separate statistical model of the BMD distribution were automatically constructed from a set of Quantitative Computed Tomography (QCT) scans. The reconstruction method incorporates a fully automatic intensity based 3D-2D registration process, maximizing the similarity between the DXA and a digitally reconstructed radiograph of the combined model. For the construction of the models, an in vitro dataset of QCT scans of 60 anatomical specimens was used. To evaluate the reconstruction accuracy, experiments were performed on simulated DXA images from the QCT scans of 30 anatomical specimens. Comparisons between the reconstructions and the same subject QCT scans showed a mean shape accuracy of 1.2mm, and a mean density error of 81mg/cm3. The results show that this method is capable of accurately reconstructing both the 3D shape and 3D BMD distribution of the proximal femur from DXA images used in clinical routine, potentially improving the diagnosis of osteoporosis and fracture risk assessments at a low radiation dose and low cost.

  4. Firn density profile at Megadunes, East Antarctica, calls for an improved densification model for low accumulation sites.

    Science.gov (United States)

    Suwa, M.; Severinghaus, J. P.

    2004-12-01

    We report a density profile of the firn at Megadunes, East Antarctica (80o78'S; 124o50'E). The Megadunes site is characterized by a low mass accumulation rate (2.9 g/cm2/yr) and cold temperature (mean annual = -49.5oC). Validating existing firn densification models using a density profile of such a site is important because such models, either purely empirical or mechanistic, have been calibrated with few sites that are analogous to a glacial condition (ultralow accumulation and temperature). We make use of CO2 concentrations in the lock-in (or non-diffusive) zone to obtain the accumulation rate, assuming that the gas in the lock-in zone ages at the same rate as the surrounding ice [Battle et al., 1996], and assuming that the gas enclosure rate must equal the long-term mean accumulation rate. This estimate is preliminary and may change when results from beta analysis of cores become available. Our density profile shows that the widely used pure empirical model by Herron and Langway [1980] overestimates the close-off depth by 16 %, and the semi-mechanistic model by Pimienta and Barnola [Barnola et al., 1991] also overestimates the close-off depth by 26 %. Our study at the Megadunes site indicates that the δ 15N of N2 paradox for glacial ice from East Antarctica would have partly resulted from a poorly calibrated densification model for a `glacial-like' condition and a thick convective zone as we observed at the Megadunes site [Severinghaus et al., in prep].

  5. Studies on column size scale-up and flow profile in conical shape liquid chromatographic column of 10° by visualization method

    Institute of Scientific and Technical Information of China (English)

    Guan Wenna; Tan Feng; Guan Yafeng

    2006-01-01

    An improved visualization device made of polymethyl methacrylate (PMMA) was used to study the 3D flow profile inside conical columns of a 10° opening angle packed with C18 phase.The outside wall of the conical columns was rectangular in shape in order to improve the transparency property of the column wall and reduce the deformation of the image for better observation of the flow profiles of colored solutes inside the column.The influence of flow rate,particle size and shape on the flow profile of a colored band were studied on a 5-cm-long column and a scaled-up column of four fold in volume.It was found that the flow rates of the mobile phase had little influence on the flat flow profile of the iodine band while the properties of the stationary phase had a certain influence on them.We observed that the flow profiles of the scaled-up column were flat during the whole chromatographic process,and the efficiency and resolution of the column were also increased in accordance with theoretical prediction.The experimental results proved that the 10° conical columns can be proportionally scaled up while still keeping the flat flow profile,sample load per unit volume of packing material,and column efficiency,which are superior to the conventional column.

  6. Structure formation in parallel ion flow and density profiles by cross-ferroic turbulent transport in linear magnetized plasma

    Science.gov (United States)

    Kobayashi, T.; Inagaki, S.; Kosuga, Y.; Sasaki, M.; Nagashima, Y.; Yamada, T.; Arakawa, H.; Kasuya, N.; Fujisawa, A.; Itoh, S.-I.; Itoh, K.

    2016-10-01

    In this paper, we show the direct observation of the parallel flow structure and the parallel Reynolds stress in a linear magnetized plasma, in which a cross-ferroic turbulence system is formed [Inagaki et al., Sci. Rep. 6, 22189 (2016)]. It is shown that the parallel Reynolds stress induced by the density gradient driven drift wave is the source of the parallel flow structure. Moreover, the generated parallel flow shear by the parallel Reynolds stress is found to drive the parallel flow shear driven instability D'Angelo mode, which coexists with the original drift wave. The excited D'Angelo mode induces the inward particle flux, which seems to help in maintaining the peaked density profile.

  7. Core and Wing Densities of Asymmetric Coronal Spectral Profiles: Implications for the Mass Supply of the Solar Corona

    Science.gov (United States)

    Patsourakos, S.; Klimchuk, J. A.; Young, P. R.

    2014-01-01

    Recent solar spectroscopic observations have shown that coronal spectral lines can exhibit asymmetric profiles, with enhanced emissions at their blue wings. These asymmetries correspond to rapidly upflowing plasmas at speeds exceeding approximately equal to 50 km per sec. Here, we perform a study of the density of the rapidly upflowing material and compare it with that of the line core that corresponds to the bulk of the plasma. For this task, we use spectroscopic observations of several active regions taken by the Extreme Ultraviolet Imaging Spectrometer of the Hinode mission. The density sensitive ratio of the Fe(sub XIV) lines at 264.78 and 274.20 Angstroms is used to determine wing and core densities.We compute the ratio of the blue wing density to the core density and find that most values are of order unity. This is consistent with the predictions for coronal nanoflares if most of the observed coronal mass is supplied by chromospheric evaporation driven by the nanoflares. However, much larger blue wing-to-core density ratios are predicted if most of the coronal mass is supplied by heated material ejected with type II spicules. Our measurements do not rule out a spicule origin for the blue wing emission, but they argue against spicules being a primary source of the hot plasma in the corona. We note that only about 40% of the pixels where line blends could be safely ignored have blue wing asymmetries in both Fe(sub XIV) lines. Anticipated sub-arcsecond spatial resolution spectroscopic observations in future missions could shed more light on the origin of blue, red, and mixed asymmetries.

  8. Linear shaped charge

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, David; Stofleth, Jerome H.; Saul, Venner W.

    2017-07-11

    Linear shaped charges are described herein. In a general embodiment, the linear shaped charge has an explosive with an elongated arrowhead-shaped profile. The linear shaped charge also has and an elongated v-shaped liner that is inset into a recess of the explosive. Another linear shaped charge includes an explosive that is shaped as a star-shaped prism. Liners are inset into crevices of the explosive, where the explosive acts as a tamper.

  9. Density profile characterization and modeling at Paranal and Armazones 2k sites

    Directory of Open Access Journals (Sweden)

    Marín Julio C.

    2017-01-01

    Full Text Available The Cherenkov Telescope Array (CTA in the southern hemisphere will be installed at Armazones 2k site in northern Chile. Scarce atmospheric observations are available in the region, particularly radiosonde data. This study analyzes radiosondes launched at Paranal observatory, located at about 21 km from the CTA site, from 24 October and 4 November 2011, to understand the behavior of density in the atmosphere near the CTA site. High-resolution numerical simulations with the Weather Research and Forecasting (WRF model are validated with Paranal radiosondes to quantify its ability to represent the atmospheric conditions in the region. In addition, the seasonal and diurnal evolution of atmospheric density at the CTA site were studied during 2011 using the high-resolution weather forecasts from the WRF model.

  10. Vortex line density in counterflowing He II with laminar and turbulent normal fluid velocity profiles

    CERN Document Server

    Baggaley, A W

    2013-01-01

    Superfluid helium is an intimate mixture of a viscous normal fluid, with continuous vorticity, and an inviscid superfluid, where vorticity is constrained to thin, stable topological defects. One mechanism to generate turbulence in this system is through the application of a heat flux, so called thermal counterflow. Of particular interest is how turbulence in the superfluid responds to both a laminar and turbulent normal fluid in the presence of walls. We model superfluid vortex lines as reconnecting space curves with fixed circulation, and consider both laminar (Poiseuille) and turbulent normal fluid flows in a channel configuration. Using high resolution numerical simulations we show that turbulence in the normal fluid sustains a notably higher vortex line density than a laminar flow with the same mean flow rate. We exam Vinen's relation, $\\sqrt{L}=\\gamma v_{ns}$, between the steady state vortex line density $L$ and the counterflow velocity $v_{ns}$. Our results support the hypothesis that transition to turb...

  11. One-dimensional transport of interacting particles: currents, density profiles, phase diagrams, and symmetries.

    Science.gov (United States)

    Dierl, Marcel; Einax, Mario; Maass, Philipp

    2013-06-01

    Driven lattice gases serve as canonical models for investigating collective transport phenomena and properties of nonequilibrium steady states. Here we study one-dimensional transport with nearest-neighbor interactions both in closed bulk systems and in open channels coupled to two particle reservoirs at the ends of the channel. For the widely employed Glauber rates we derive an exact current-density relation in the bulk for unidirectional hopping. An approach based on time-dependent density functional theory provides a good description of the kinetics. For open systems, the system-reservoir couplings are shown to have a striking influence on boundary-induced phase diagrams. The role of particle-hole symmetry is discussed, and its consequence for the topology of the phase diagrams. It is furthermore demonstrated that systems with weak bias can be mapped onto systems with unidirectional hopping.

  12. Living in a dangerous world: the shaping of behavioral profile by early environment and 5-HTT genotype

    Directory of Open Access Journals (Sweden)

    Rebecca S Heiming

    2009-09-01

    Full Text Available Anxiety and anxiety disorders are influenced by both, environmental and genetic factors. One genetic factor under scrutiny for anxiety disorders is the genetically encoded variation of the serotonin transporter (5-HTT. The aim of this study was to elucidate the effects of a threatening environment during early phases of life on anxiety-like (ANX and exploratory behavior (EXP in adult mice, varying in serotonin transporter (5-HTT genotype. For this purpose, pregnant and lactating 5-HTT +/- dams were repeatedly exposed to olfactory cues of unfamiliar adult males by introducing small amounts of soiled bedding to their home cage. These stimuli signal the danger of infanticide and simulate a threatening environment. Control females were treated with neutral bedding. The offspring (5-HTT +/+, +/-, -/- were examined for their ANX and EXP. The main results were: (1 a main effect of genotype existed, with 5-HTT -/- showing higher levels of ANX and lower levels of EXP than 5-HTT +/- and wildtypes. (2 When mothers had lived in a threatening environment, their offspring showed increased ANX and reduced EXP compared to controls. (3 These effects were most pronounced in 5-HTT -/- mice. By applying a new ecologically relevant paradigm we conclude: If 5-HTT +/- mothers live in a threatening environment during pregnancy and lactation, their offspring behavioral profile will, in principle, be shaped in an adaptive way preparing the young for an adverse environment. This process is, however, modulated by 5-HTT genotype, bearing the risk that individuals with impaired serotonergic neurotransmission (5-HTT -/- will develop an exaggerated, potentially pathological level of anxiety from gene x environment interactions.

  13. Biconcave shape of human red-blood-cell ghosts relies on density differences between the rim and dimple of the ghost's plasma membrane.

    Science.gov (United States)

    Hoffman, Joseph F

    2016-12-20

    The shape of the human red blood cell is known to be a biconcave disk. It is evident from a variety of theoretical work that known physical properties of the membrane, such as its bending energy and elasticity, can explain the red-blood-cell biconcave shape as well as other shapes that red blood cells assume. But these analyses do not provide information on the underlying molecular causes. This paper describes experiments that attempt to identify some of the underlying determinates of cell shape. To this end, red-blood-cell ghosts were made by hypotonic hemolysis and then reconstituted such that they were smooth spheres in hypo-osmotic solutions and smooth biconcave discs in iso-osmotic solutions. The spherical ghosts were centrifuged onto a coated coverslip upon which they adhered. When the attached spheres were changed to biconcave discs by flushing with an iso-osmotic solution, the ghosts were observed to be mainly oriented in a flat alignment on the coverslip. This was interpreted to mean that, during centrifugation, the spherical ghosts were oriented by a dense band in its equatorial plane, parallel to the centrifugal field. This appears to be evidence that the difference in the densities between the rim and the dimple regions of red blood cells and their ghosts may be responsible for their biconcave shape.

  14. Recreational football improves bone mineral density and bone turnover marker profile in elderly men

    DEFF Research Database (Denmark)

    Helge, E W; Andersen, T R; Schmidt, J F;

    2014-01-01

    This study examined the effect of recreational football and resistance training on bone mineral density (BMD) and bone turnover markers (BTMs) in elderly men. Twenty-six healthy sedentary men (age 68.2 ± 3.2 years) were randomized into three groups: football (F; n = 9) and resistance training (R; n...... training had no effect. The anabolic response may be due to increased bone turnover, especially improved bone formation....

  15. Differential gene expression profiles in foetal skin of Rex rabbits with different wool density

    Directory of Open Access Journals (Sweden)

    L. Liu

    2016-09-01

    Full Text Available This study investigated the mechanisms controlling hair follicle development in the Rex rabbit. The Agilent rabbit gene expression microarray was used to determine differentially expressed genes in Rex rabbit foetuses with different wool densities. The expression patterns of selected differentially-expressed genes were further investigated by quantitative real-time PCR. Compared to low wool density rabbits, 1342 differentially expressed probes were identified in high wool density rabbits, including 950 upregulated probes and 392 downregulated probes. Gene ontology analysis revealed that the most upregulated differentially expressed probes belonged to receptors and the most downregulated differentially expressed probes belonged to DNA binding molecules. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the differentially expressed probes were mainly involved in the sonic hedgehog (Shh and Eph signalling pathways. The results also suggest that transforming growth factor-beta 1, growth hormone receptor, and the keratin-associated protein 6.1 genes, as well as the Shh and Eph signalling pathways, may be involved in the regulation of hair follicle developmental in Rex rabbits.

  16. Citrus reticulata’s Peels Modulate Blood Cholesterol Profile and IncreaseBone Density of Ovariectomized Rats

    Directory of Open Access Journals (Sweden)

    Rosa Adelina

    2015-11-01

    Full Text Available Hormon Replacement Therapy is a common therapy for estrogen deficiency but in other side it will increase the risk of cardiovascular disease. Another alternative therapy which relatively more safe is using phytoestrogen. The Citrus reticulata’s peel contain flavanone and polimethoxyflavone which are suspected to give estrogenic effect, therefore it is potential to be used as phytoestrogen.The purpose of this study was to examine the estrogenic effect of Citrus reticulata’s peel extract in modulation of bone density and blood cholesterol profile of ovariectomized rats (OVX, an animal model of postmenopausal osteoporosis. Thirty six 7-weeks-old female Sprague Dawley rats were assigned to six groups: a SO group, an OVX group, an OVX+CMCNa group, an OVX+extract dose 500 mg/kgBW group, an OVX+extract dose 1000 mg/kgBW group, and an OVX+estradiol group. After 7 weeks, the rats were killed then blood and femoral were collected immediately. The rontgenogram indicated that extract and estradiol administration increase the bone density. And the data analysis with Oneway ANOVA test ,followed by Shceffé test (P 0.05 showed that extract can improve blood cholesterol profile in dose depend manner. These results suggest a possible role of Citrus reticulata’s peel extract as women’s health agent because of its beneficial effects on bone and lipids.

  17. Genome-wide copy number profiling using high-density SNP array in chickens.

    Science.gov (United States)

    Yi, G; Qu, L; Chen, S; Xu, G; Yang, N

    2015-04-01

    Phenotypic diversity is a direct consequence resulting mainly from the impact of underlying genetic variation, and recent studies have shown that copy number variation (CNV) is emerging as an important contributor to both phenotypic variability and disease susceptibility. Herein, we performed a genome-wide CNV scan in 96 chickens from 12 diversified breeds, benefiting from the high-density Affymetrix 600 K SNP arrays. We identified a total of 231 autosomal CNV regions (CNVRs) encompassing 5.41 Mb of the chicken genome and corresponding to 0.59% of the autosomal sequence. The length of these CNVRs ranged from 2.6 to 586.2 kb with an average of 23.4 kb, including 130 gain, 93 loss and eight both gain and loss events. These CNVRs, especially deletions, had lower GC content and were located particularly in gene deserts. In particular, 102 CNVRs harbored 128 chicken genes, most of which were enriched in immune responses. We obtained 221 autosomal CNVRs after converting probe coordinates to Galgal3, and comparative analysis with previous studies illustrated that 153 of these CNVRs were regarded as novel events. Furthermore, qPCR assays were designed for 11 novel CNVRs, and eight (72.73%) were validated successfully. In this study, we demonstrated that the high-density 600 K SNP array can capture CNVs with higher efficiency and accuracy and highlighted the necessity of integrating multiple technologies and algorithms. Our findings provide a pioneering exploration of chicken CNVs based on a high-density SNP array, which contributes to a more comprehensive understanding of genetic variation in the chicken genome and is beneficial to unearthing potential CNVs underlying important traits of chickens. © 2015 Stichting International Foundation for Animal Genetics.

  18. Density profile in shock wave fronts of partially ionized xenon plasmas

    CERN Document Server

    Reinholz, H; Morozov, I; Mintsev, V; Zaparoghets, Y; Fortov, V; Wierling, A

    2003-01-01

    Results for the reflection coefficient of shock-compressed dense xenon plasmas at pressures of 1.6-20 GPa and temperatures around 30 000 K are interpreted. In addition to former experiments using laser beams with lambda = 1.06 mu m, measurements at lambda = 0.694 mu m have been performed recently. Reflectivities typical for metallic systems are found at high densities. Besides free carriers, the theoretical description also takes into account the influence of the neutral component of the plasma on the reflectivity. A consistent description of the measured reflectivities is achieved only if a finite width of the shock wave front is considered.

  19. Density profile evolution and nonequilibrium effects in partial and full spreading measurements of surface diffusion

    DEFF Research Database (Denmark)

    Nikunen, P.; Vattulainen, Ilpo Tapio; Ala-Nissila, T.

    2001-01-01

    in D-C(theta) depend on the initial density gradient and the initial state from which the spreading starts. To this end, we carry out extensive Monte Carlo simulations for a lattice-gas model of the O/W(110) system. Studies of submonolayer spreading from an initially ordered p(2x1) phase at theta = 1....../2 reveal that the spreading and diffusion rates in directions parallel and perpendicular to rows of oxygen atoms are significantly different within the ordered phase. Aside from this effect, we find that the degree of ordering in the initial phase has a relatively small impact on the overall behavior of D...

  20. Density and current profiles in Uq (A2(1)) zero range process

    Science.gov (United States)

    Kuniba, A.; Mangazeev, V. V.

    2017-09-01

    The stochastic R matrix for Uq (An(1)) introduced recently gives rise to an integrable zero range process of n classes of particles in one dimension. For n = 2 we investigate how finitely many first class particles fixed as defects influence the grand canonical ensemble of the second class particles. By using the matrix product stationary probabilities involving infinite products of q-bosons, exact formulas are derived for the local density and current of the second class particles in the large volume limit.

  1. Flow rate of particles through apertures obtained from self-similar density and velocity profiles

    OpenAIRE

    2012-01-01

    ‘‘Beverloo’s law’’ is considered as the standard expression to estimate the flow rate of particles through apertures. This relation was obtained by simple dimensional analysis and includes empirical parameters whose physical meaning is poorly justified. In this Letter, we study the density and velocity profiles in the flow of particles through an aperture. We find that, for the whole range of apertures studied, both profiles are self-similar. Hence, by means of the functionality obtained for the...

  2. Measurements of Electron Density Profiles of Plasmas Produced by Nike KrF Laser for Laser Plasma Instability (LPI) Research

    Science.gov (United States)

    Oh, Jaechul; Weaver, J. L.; Obenschain, S. P.; Schmitt, A. J.; Kehne, D. M.; Karasik, M.; Chan, L.-Y.; Serlin, V.; Phillips, L.

    2013-10-01

    Knowing spatial profiles of electron density (ne) in the underdense coronal region (n Nike LPI experiment, a side-on grid imaging refractometer (GIR) was deployed for measuring the underdense plasma profiles. Plasmas were produced from flat CH targets illuminated by Nike KrF laser with total energies up to 1 kJ of 0.5 ~ 1 nsec FWHM pulses. The GIR resolved ne up to 3 ×1021 /cm3 in space taking 2D snapshot images of probe laser (λ = 263 nm, Δt = 10 ps) beamlets (50 μm spacing) refracted by the plasma at a selected time during the laser illumination. The individual beamlet transmittances were also measured for Te estimation. Time-resolved spectrometers with an absolute-intensity-calibrated photodiode array and a streak camera simultaneously detected light emission from the plasma in spectral ranges relevant to Raman (SRS) and two plasmon decay instabilities. The measured spatial profiles are compared with simulation results from the FAST3D radiation hydrocode and their effects on the LPI observations are investigated. Work supported by DoE/NNSA and performed at Naval Research Laboratory.

  3. Experimental Profiling of a Non-truncated Focused Gaussian Beam and Fine-tuning of the Quadratic Phase in the Fresnel Gaussian Shape Invariant

    Energy Technology Data Exchange (ETDEWEB)

    S., Juan Manuel Franco [Center of Investigation (CIO) (Mexico); Cywiak, Moises [Center of Investigation (CIO) (Mexico); Cywiak, David [National Metrology Center (Mexico); Mourad, Idir [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-06-24

    A homodyne profiler is used for recording the intensity distribution of focused non-truncated Gaussian beams. The spatial distributions are obtained at planes in the vicinity of the back-focal plane of a focusing lens placed at different distances from a He–Ne laser beam with a Gaussian intensity profile. Comparisons of the experimental data with those obtained from the analytical equations for an ideal focusing lens allow us to propose formulae to fine-tune the quadratic term in the Fresnel Gaussian shape invariant at each interface of the propagated field. Furthermore, we give analytical expressions to calculate adequately the propagation of the field through an optical system.

  4. Computational modeling of Krypton gas puffs with tailored mass density profiles on Z

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, C. A.; Ampleford, D. J.; Lamppa, D. C.; Hansen, S. B.; Jones, B.; Harvey-Thompson, A. J.; Jobe, M.; Strizic, T.; Reneker, J.; Rochau, G. A.; Cuneo, M. E. [Sandia National Laboratories, PO Box 5800, Albuquerque, New Mexico 87185 (United States)

    2015-05-15

    Large diameter multi-shell gas puffs rapidly imploded by high current (∼20 MA, ∼100 ns) on the Z generator of Sandia National Laboratories are able to produce high-intensity Krypton K-shell emission at ∼13 keV. Efficiently radiating at these high photon energies is a significant challenge which requires the careful design and optimization of the gas distribution. To facilitate this, we hydrodynamically model the gas flow out of the nozzle and then model its implosion using a 3-dimensional resistive, radiative MHD code (GORGON). This approach enables us to iterate between modeling the implosion and gas flow from the nozzle to optimize radiative output from this combined system. Guided by our implosion calculations, we have designed gas profiles that help mitigate disruption from Magneto-Rayleigh–Taylor implosion instabilities, while preserving sufficient kinetic energy to thermalize to the high temperatures required for K-shell emission.

  5. Association of Maternal Antiangiogenic Profile at Birth With Early Postnatal Loss of Microvascular Density in Offspring of Hypertensive Pregnancies

    Science.gov (United States)

    Yu, Grace Z.; Aye, Christina Y.L.; Lewandowski, Adam J.; Davis, Esther F.; Khoo, Cheen P.; Newton, Laura; Yang, Cheng T.; Al Haj Zen, Ayman; Simpson, Lisa J.; O’Brien, Kathryn; Cook, David A.; Granne, Ingrid; Kyriakou, Theodosios; Channon, Keith M.; Watt, Suzanne M.

    2016-01-01

    Offspring of hypertensive pregnancies are more likely to have microvascular rarefaction and increased blood pressure in later life. We tested the hypothesis that maternal angiogenic profile during a hypertensive pregnancy is associated with fetal vasculogenic capacity and abnormal postnatal microvascular remodeling. Infants (n=255) born after either hypertensive or normotensive pregnancies were recruited for quantification of postnatal dermal microvascular structure at birth and 3 months of age. Vasculogenic cell potential was assessed in umbilical vein endothelial cells from 55 offspring based on in vitro microvessel tube formation and proliferation assays. Maternal angiogenic profile (soluble fms-like tyrosine kinase-1, soluble endoglin, vascular endothelial growth factor, and placental growth factor) was measured from postpartum plasma samples to characterize severity of pregnancy disorder. At birth, offspring born after hypertensive pregnancy had similar microvessel density to those born after a normotensive pregnancy, but during the first 3 postnatal months, they had an almost 2-fold greater reduction in total vessel density (−17.7±16.4% versus −9.9±18.7%; P=0.002). This postnatal loss varied according to the vasculogenic capacity of the endothelial cells of the infant at birth (r=0.49; P=0.02). The degree of reduction in both in vitro and postnatal in vivo vascular development was proportional to levels of antiangiogenic factors in the maternal circulation. In conclusion, our data indicate that offspring born to hypertensive pregnancies have reduced vasculogenic capacity at birth that predicts microvessel density loss over the first 3 postnatal months. Degree of postnatal microvessel reduction is proportional to levels of antiangiogenic factors in the maternal circulation at birth. PMID:27456522

  6. Application of Thomson scattering at 1.06{mu}m as a diagnostic for spatial profile measurements of electron temperature and density on the TCV tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Franke, S. [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP)

    1997-04-01

    The variable configuration tokamak, TCV, in operation at CRPP since the end of 1991, is a particularly challenging machine with regard to the experimental system that must provide essential information regarding properties of confined plasmas with strongly shaped, non-circular cross-sections. The importance of the energy confinement issue in a machine designed specifically for the investigation of the effect of plasma shape on confinement and stability is self-evident, as is the necessity for a diagnostic capable of providing the profiles of electron temperature and density required for evaluation of this confinement. For TCV, a comprehensive Thomson Scattering (TS) diagnostic was the natural choice, specifically owing to the resulting spatially localized and time resolved measurement. The details of the system installed on TCV, together with the results obtained from the diagnostic comprise the subject matter of this thesis. A first version of the diagnostic was equipped with only ten observation volumes. In this case, adequate spatial resolution can only be maintained if measurements are limited to plasmas located in the upper half of the highly elongated TCV vacuum vessel. The system has recently been upgraded through the addition of a further fifteen observation volumes, together with major technical improvements in the scattered light detection system. This new version now permits TS observations in all TCV plasma configurations, including equilibria produced in the lower and upper halves of the vacuum vessel and the highly elongated plasmas now routinely created. Whilst a description of the new detection system along with some results obtained using the extended set of observation volumes are included, this thesis reports principally on the hardware details of and the interpretation of data from the original, ten observation volume system. (author) figs., tabs., 75 refs.

  7. Application of Thomson scattering at 1.06{mu}m as a diagnostic for spatial profile measurements of electron temperature and density on the TCV tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Franke, S. [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP)

    1997-04-01

    The variable configuration tokamak, TCV, in operation at CRPP since the end of 1991, is a particularly challenging machine with regard to the experimental system that must provide essential information regarding properties of confined plasmas with strongly shaped, non-circular cross-sections. The importance of the energy confinement issue in a machine designed specifically for the investigation of the effect of plasma shape on confinement and stability is self-evident, as is the necessity for a diagnostic capable of providing the profiles of electron temperature and density required for evaluation of this confinement. For TCV, a comprehensive Thomson Scattering (TS) diagnostic was the natural choice, specifically owing to the resulting spatially localized and time resolved measurement. The details of the system installed on TCV, together with the results obtained from the diagnostic comprise the subject matter of this thesis. A first version of the diagnostic was equipped with only ten observation volumes. In this case, adequate spatial resolution can only be maintained if measurements are limited to plasmas located in the upper half of the highly elongated TCV vacuum vessel. The system has recently been upgraded through the addition of a further fifteen observation volumes, together with major technical improvements in the scattered light detection system. This new version now permits TS observations in all TCV plasma configurations, including equilibria produced in the lower and upper halves of the vacuum vessel and the highly elongated plasmas now routinely created. Whilst a description of the new detection system along with some results obtained using the extended set of observation volumes are included, this thesis reports principally on the hardware details of and the interpretation of data from the original, ten observation volume system. (author) figs., tabs., 75 refs.

  8. The Co-Evolution of Total Density Profiles and Central Dark Matter Fractions in Simulated Early-Type Galaxies

    CERN Document Server

    Remus, Rhea-Silvia; Naab, Thorsten; Burkert, Andreas; Hirschmann, Michaela; Hoffmann, Tadziu L; Johansson, Peter H

    2016-01-01

    We present evidence from cosmological hydrodynamical simulations for a co-evolution of the slope of the total (dark and stellar) mass density profiles, gamma_tot, and the dark matter fractions within the half-mass radius, f_DM, in early-type galaxies. The relation can be described as gamma_tot = A f_DM + B and holds for all systems at all redshifts. We test different feedback models and find that the general trend is independent of the assumed feedback processes and is set by the decreasing importance of dissipative processes towards lower redshifts and for more massive systems. Early-type galaxies are smaller, more concentrated, have lower dark matter fractions and steeper total density slopes at high redshifts and at lower masses for a given redshift. The values for A and B change distinctively with the assumed feedback model, and thus this relation can be used as a test for feedback models. A similar correlation exists between gamma_tot and the stellar mass surface density Sigma_*. The model with weak stel...

  9. Profile of cortisol, glycaemia, and blood parameters of American Bullfrog tadpoles Lithobates catesbeianus exposed to density and hypoxia stressors

    Directory of Open Access Journals (Sweden)

    Patricia C. Teixeira

    2012-12-01

    Full Text Available The aim of this study was to evaluate alterations to the physiological profile (cortisol, glycaemia, and blood parameters of Lithobates catesbeianus caused by the stressors density and hypoxia. The organisms were in the prometamorphosis stage and exposed to different tadpole densities: 1 tadpole/L (T1, 5 tadpoles/L (T2, and 10 tadpoles/L (T3 for 12 days. The blood was collected through the rupture of the caudal blood vessel and collected under normoxia (immediate collection and hypoxia (after 15 minutes of air exposure conditions. Cortisol levels rose on the fourth and eighth days of treatment and returned to basal levels by the end of the experiment. The stressor mechanisms tested did not affect glycaemia. White blood cells (total number of lymphocytes, neutrophils, and eosinophils showed a significant difference at the twelfth day of the experiment when compared with the start of the experiment. We concluded that, under controlled conditions, a density of up to 10 tadpoles/L and air exposure for 15 minutes did not cause harmful physiological alterations during the experimental period. The answer to these stressors maybe was in another hormonal level (corticosterone.

  10. A method for evaluating models that use galaxy rotation curves to derive the density profiles

    CERN Document Server

    de Almeida, Álefe O F; Rodrigues, Davi C

    2016-01-01

    There are some approaches, either based on General Relativity (GR) or modified gravity, that use galaxy rotation curves to derive the matter density of the corresponding galaxy, and this procedure would either indicate a partial or a complete elimination of dark matter in galaxies. Here we review these approaches, clarify the difficulties on this inverted procedure, present a method for evaluating them, and use it to test two specific approaches that are based on GR: the Cooperstock-Tieu (CT) and the Balasin-Grumiller (BG) approaches. Using this new method, we find that neither of the tested approaches can satisfactorily fit the observational data without dark matter. The CT approach results can be significantly improved if some dark matter is considered, while for the BG approach no usual dark matter halo can improve its results.

  11. A method for evaluating models that use galaxy rotation curves to derive the density profiles

    Science.gov (United States)

    de Almeida, Álefe O. F.; Piattella, Oliver F.; Rodrigues, Davi C.

    2016-11-01

    There are some approaches, either based on General Relativity (GR) or modified gravity, that use galaxy rotation curves to derive the matter density of the corresponding galaxy, and this procedure would either indicate a partial or a complete elimination of dark matter in galaxies. Here we review these approaches, clarify the difficulties on this inverted procedure, present a method for evaluating them, and use it to test two specific approaches that are based on GR: the Cooperstock-Tieu (CT) and the Balasin-Grumiller (BG) approaches. Using this new method, we find that neither of the tested approaches can satisfactorily fit the observational data without dark matter. The CT approach results can be significantly improved if some dark matter is considered, while for the BG approach no usual dark matter halo can improve its results.

  12. Exact nonlinear analytic Vlasov-Maxwell tangential equilibria with arbitrary density and temperature profiles

    CERN Document Server

    Mottez, F

    2003-01-01

    The tangential layers are characterized by a bulk plasma velocity and a magnetic field that are perpendicular to the gradient direction. They have been extensively described in the frame of the Magneto-Hydro-Dynamic (MHD) theory. But the MHD theory does not look inside the transition region if the transition has a size of a few ion gyroradii. A series of kinetic tangential equilibria, valid for a collisionless plasma is presented. These equilibria are exact analytical solutions of the Maxwell-Vlasov equations. The particle distribution functions are sums of an infinite number of elementary functions parametrized by a vector potential. Examples of equilibria relevant to space plasmas are shown. A model for the deep and sharp density depletions observed in the auroral zone of the Earth is proposed. Tangential equilibria are also relevant for the study of planetary environments and of remote astrophysical plasmas.

  13. Global SAXS data analysis for multilamellar vesicles: Evolution of the scattering density profile (SDP) model

    CERN Document Server

    Heftberger, Peter; Heberle, Frederick A; Pan, Jianjun; Rappolt, Michael; Amenitsch, Heinz; Kucerka, Norbert; Katsaras, John; Pabst, Georg

    2013-01-01

    We adapted the highly successful scattering density pro?le (SDP) model, which is used to jointly analyze small angle x-ray and neutron scattering data from unilamellar vesicles, for use with data from fully hydrated, liquid crystalline multilamellar vesicles (MLVs). By using a genetic algorithm, this new method is capable of providing high resolution structural information, as well as determining bilayer elastic bending fluctuations from standalone x-ray data. Important structural parameters, such as bilayer thickness and area per lipid were determined for a series of saturated and unsaturated lipids, as well as binary mixtures with cholesterol. Results are in good agreement with previously reported SDP data, which used both neutron and x-ray data. The addition of deuterated and non-deuterated MLV neutron data to the analysis improved lipid backbone information, but did not improve, within experimental uncertainties, the structural information regarding bilayer thickness and area per lipid.

  14. Time Ordering Effects on Hydrogen Zeeman-Stark Line Profiles in Low-Density Magnetized Plasmas

    Directory of Open Access Journals (Sweden)

    J. Rosato

    2010-01-01

    Full Text Available Stark broadening of hydrogen lines is investigated in low-density magnetized plasmas, at typical conditions of magnetic fusion experiments. The role of time ordering is assessed numerically, by using a simulation code accounting for the evolution of the microscopic electric field generated by the charged particles moving at the vicinity of the atom. The Zeeman effect due to the magnetic field is also retained. Lyman lines with a low principal quantum number n are first investigated, for an application to opacity calculations; next Balmer lines with successively low and high principal quantum numbers are considered for diagnostic purposes. It is shown that neglecting time ordering results in a dramatic underestimation of the Stark effect on the low-n lines. Another conclusion is that time ordering becomes negligible only when ion dynamics effects vanish, as shown in the case of high-n lines.

  15. Safety profile of subjects treated to very low low-density lipoprotein cholesterol levels (JUPITER).

    Science.gov (United States)

    Everett, Brendan M; Mora, Samia; Glynn, Robert J; MacFadyen, Jean; Ridker, Paul M

    2014-12-01

    Recent US guidelines expand the indications for high-intensity statin therapy, yet data on the safety of attaining very low-density lipoprotein cholesterol (LDL-C) levels are scarce. Among 16,304 participants in the Justification for the Use of Statins in Prevention: An Intervention Trial Evaluating Rosuvastatin (JUPITER) with on-treatment LDL-C levels, we identified 767 who did and 7,387 who did not achieve LDL-C JUPITER, achieving LDL-C levels <30 mg/dl with high-intensity statin therapy appeared to be generally well tolerated but associated with certain adverse events, including more physician-reported diabetes, hematuria, hepatobiliary disorders, and insomnia. These data may guide the monitoring of patients on intensive statin therapy and adverse events in trials of therapies that lead to very low LDL-C levels.

  16. Controlling the Transient Interface Shape and Deposition Profile Left by Desiccation of Colloidal Droplets on Multiple Polymer Surfaces

    Science.gov (United States)

    Dunning, Peter David

    . Implementation of this technique requires that the colloidal droplet be separated from the active electrode by a dielectric layer to prevent electrolysis. A variety of polymer layers have been used in EWOD devices for a variety of applications. In applications that involve desiccation of colloidal suspensions, the material for this layer should be chosen carefully as it can play an important role in the resulting deposition pattern. An experimental method to monitor the transient evolution of the shape of an evaporating colloidal droplet and optically quantify the resultant deposition pattern is presented. Unactuated colloidal suspensions will be desiccated on a variety of substrates commonly used in EWOD applications. Transient image profiles and particle deposition patterns are examined for droplets containing fluorescent micro-particles. Qualitative and quantitative comparisons of these results will be used to compare multiple different cases in an effort to provide insight into the effects of polymer selection on the drying dynamics and resultant deposition patterns of desiccated colloidal materials. It was found that the equilibrium and receding contact angles between the surface and the droplet play a key role in the evaporation dynamics and the resulting deposition patterns left by a desiccated colloidal suspension. The equilibrium contact angle controls the initial contact diameter for a droplet of a given volume. As a droplet on a surface evaporates, the evolution of the interface shape and the contact diameter can generally be described by three different regimes. The Constant Contact Radius (CCR) regime occurs when the contact line is pinned while the contact angle decreases. The Constant Contact Angle (CCA) regime occurs when the contact line recedes while the contact angle remains constant. The Mixed regime occurs when the contact radius and angle both reduce over time. The presence of the CCA regime allows the contact line to recede creating a more uniform

  17. Communication: Exciton analysis in time-dependent density functional theory: How functionals shape excited-state characters.

    Science.gov (United States)

    Mewes, Stefanie A; Plasser, Felix; Dreuw, Andreas

    2015-11-01

    Excited-state descriptors based on the one-particle transition density matrix referring to the exciton picture have been implemented for time-dependent density functional theory. State characters such as local, extended ππ(∗), Rydberg, or charge transfer can be intuitively classified by simple comparison of these descriptors. Strong effects of the choice of the exchange-correlation kernel on the physical nature of excited states can be found and decomposed in detail leading to a new perspective on functional performance and the design of new functionals.

  18. Sunlight Modulates Fruit Metabolic Profile and Shapes the Spatial Pattern of Compound Accumulation within the Grape Cluster

    Science.gov (United States)

    Reshef, Noam; Walbaum, Natasha; Agam, Nurit; Fait, Aaron

    2017-01-01

    Vineyards are characterized by their large spatial variability of solar irradiance (SI) and temperature, known to effectively modulate grape metabolism. To explore the role of sunlight in shaping fruit composition and cluster uniformity, we studied the spatial pattern of incoming irradiance, fruit temperature and metabolic profile within individual grape clusters under three levels of sunlight exposure. The experiment was conducted in a vineyard of Cabernet Sauvignon cv. located in the Negev Highlands, Israel, where excess SI and midday temperatures are known to degrade grape quality. Filtering SI lowered the surface temperature of exposed fruits and increased the uniformity of irradiance and temperature in the cluster zone. SI affected the overall levels and patterns of accumulation of sugars, organic acids, amino acids and phenylpropanoids, across the grape cluster. Increased exposure to sunlight was associated with lower accumulation levels of malate, aspartate, and maleate but with higher levels of valine, leucine, and serine, in addition to the stress-related proline and GABA. Flavan-3-ols metabolites showed a negative response to SI, whereas flavonols were highly induced. The overall levels of anthocyanins decreased with increased sunlight exposure; however, a hierarchical cluster analysis revealed that the members of this family were grouped into three distinct accumulation patterns, with malvidin anthocyanins and cyanidin-glucoside showing contrasting trends. The flavonol-glucosides, quercetin and kaempferol, exhibited a logarithmic response to SI, leading to improved cluster uniformity under high-light conditions. Comparing the within-cluster variability of metabolite accumulation highlighted the stability of sugars, flavan-3-ols, and cinnamic acid metabolites to SI, in contrast to the plasticity of flavonols. A correlation-based network analysis revealed that extended exposure to SI modified metabolic coordination, increasing the number of negative

  19. Estimation of the mass density contrasts and the 3D geometrical shape of the source bodies, in the Yilgarn area, Eastern Goldfields, Western Australia

    DEFF Research Database (Denmark)

    Strykowski, Gabriel; Boschetti, F.; Papp, G.

    2005-01-01

    , a rough 3D shape of the source is modelled-a model consisting of the vertical mass columns of equal height. The horizontal extension is implied by the surface gravity signal. Subsequently, the shape of each source body is modified to obtain a better fit to the surface gravity data. In each modification......) and only weakly constrained by the seismic information. The result was the reconstruction of the 'rough' 3D geometry of the source bodies and the estimation of a constant mass density contrast to the surroundings. A possible extension of this technique for detailed studies of the geological model......We invert 2D surface gravity data constrained both by geological and seismic information. We use a number of pre-processing tools in order to reduce the general multi-body inversion into several single-body inversions, whereby we can reduce the overall complexity of the inversion task. This is done...

  20. Determination of density profiles of unevenly compressed wood of Po­pu­lus tremula using the X – RAY DENSE – LAB laboratory device

    Directory of Open Access Journals (Sweden)

    Aleš Dejmal

    2009-01-01

    Full Text Available The paper deals with the measuring of the density profile of unevenly pressed wood of European aspen (Populus tremula L.. The main aim of the work is to examine in an experimental way the possibilities of using the X – RAY DENSE – LAB laboratory equipment designed for the determination of density profiles of agglomerated and plied large-area materials. The work uses the X – RAY DENSE – LAB equipment to determine the density profile of the cross-section of unevenly pressed aspen wood, plasticized hydrothermically, without the presence of chemical substances. The work also presents calculations of the level of compression/densification in dependence on the density and it describes the factors that can influence the density profile of compressed/densified wood; at the same time, it presents the possible ways to determine the density profile in the cross-section. Further, it includes the creation of the methodology for sample preparation so that the results do not get distorted during measuring. It describes the preparation of sample pieces, the orientation of the anatomic structure, the methodology of pressing, air conditioning, sample preparation, their measuring and analysis. The paper also describes the theory and the principles of measuring with use of X – RAY DENSE – LAB and its calibration. The paper analyses the obtained results of density profiles and searches for and describes the causes of the uneven distribution of the density in the cross-section. It concludes by summarizing the results and recommending the procedure for future measuring.

  1. Measuring one-dimensional and two-dimensional impurity density profiles on TEXTOR using combined charge exchange-beam emission spectroscopy and ultrasoft x-ray tomography

    Science.gov (United States)

    De Bock, M.; Jakubowska, K.; Hellermann, M. von; Jaspers, R.; Donné, A. J. H.; Shmaenok, L.

    2004-10-01

    Two techniques are presented that allow us to measure impurity density profiles in the TEXTOR tokamak plasma. The one-dimensional profiles are gathered by charge exchange recombination spectroscopy (CXRS) in combination with beam emission spectroscopy (BES). Combining CXRS and BES eliminate the need for absolute calibration. For two-dimensional profiles an ultrasoft x-ray tomography system has been developed. The system is spectrally resolved and produces local emissivity profiles of several ionization stages of impurities. Both systems are presently being commissioned. They are complementary and give an insight into the impurity distribution and transport in plasmas.

  2. Effects of Fiber Denier, Fiber Cross-Sectional Shape and Fabric Density on Acoustical Behavior of Vertically Lapped Nonwoven Fabrics

    Directory of Open Access Journals (Sweden)

    Mevlut Tascan, Ph.D.

    2008-06-01

    Full Text Available Acoustical insulation and absorption properties of nonwoven fabrics depend on fiber geometry and fiber arrangement within the fabric structure. The different structures of the fibers result in different total surface areas of nonwoven fabrics. Nonwoven fabrics such as vertically lapped fabrics are ideal materials for use as acoustical insulation products, because they have high total surface. Vertically lapped nonwoven technology consists of carding, perpendicular layering of the carded webs, and through-air bonding using synthetic binder fibers. The surface area of the fabric is directly related to the denier and cross-sectional shape of the fibers in the fabric. Smaller deniers yield more fibers per unit weight of the material, higher total fiber surface area, and greater possibilities for a sound wave to interact with the fibers in the fabric structure.The research in the literature uses two methods for measuring acoustical properties of fabric materials: the impedance tube and reverberation room method. Small test samples are in the impedance tube method and sound absorption coefficient is determined at each frequency. Large reverberation rooms and large test samples are used for the reverberation room method. A direct comparative acoustical properties measurement device that was designed and fabricated at Clemson University School of Materials Science & Engineering was used to measure acoustical insulation in this research. This paper provides a description of the measurement devices and acoustical measurement data for vertically lapped nonwoven fabrics made from three different polyester fiber shape and two denier levels.

  3. Exploring pulse shaping for Z using graded-density impactors on gas guns (final report for LDRD project 79879).

    Energy Technology Data Exchange (ETDEWEB)

    Furnish, Michael David; Reinhart, William Dodd; Anderson, William W. (Los Alamos National Laboratory, Los Alamos, NM); Vogler, Tracy John; Hixson, Rob (Los Alamos National Laboratory, Los Alamos, NM); Kipp, Marlin E.

    2005-10-01

    While isentropic compression experiment (ICE) techniques have proved useful in deducing the high-pressure compressibility of a wide range of materials, they have encountered difficulties where large-volume phase transitions exist. The present study sought to apply graded-density impactor methods for producing isentropic loading to planar impact experiments to selected such problems. Cerium was chosen due to its 20% compression between 0.7 and 1.0 GPa. A model was constructed based on limited earlier dynamic data, and applied to the design of a suite of experiments. A capability for handling this material was installed. Two experiments were executed using shock/reload techniques with available samples, loading initially to near the gamma-alpha transition, then reloading. As well, two graded-density impactor experiments were conducted with alumina. A method for interpreting ICE data was developed and validated; this uses a wavelet construction for the ramp wave and includes corrections for the ''diffraction'' of wavelets by releases or reloads reflected from the sample/window interface. Alternate methods for constructing graded-density impactors are discussed.

  4. Difference between bulk and thin film densities of metal oxide and fluoride films studied by NRA depth profiling techniques

    CERN Document Server

    Coban, A; Durrani, S A

    2002-01-01

    Nuclear reaction analysis techniques have been used to study the difference between bulk and thin film densities of different dielectric (WO sub 3 , MgF sub 2 , NdF sub 3 , LaF sub 3 and ThF sub 4) thin films. Thicknesses of the films were measured by optical methods. The sup 1 sup 8 O(p,alpha) sup 1 sup 5 N reaction was used at 730 keV to profile WO sub 3 prepared with different thicknesses on a tantalum backing by thermal evaporation of natural WO sub 3. We have also successfully tested the sup 1 sup 8 O(p,alpha) sup 1 sup 5 N reaction at the 629 keV (GAMMA=2.1 keV) resonance for the same purpose. Excitation function measurement of the reaction was performed around the resonant energy at a detection angle of 150 deg. . In order to obtain the oxygen profiles of the thin films non-resonant part of the excitation function was deconvoluted using the known cross-section data of the reaction. Also, we studied different films of MgF sub 2 , NdF sub 3 , LaF sub 3 and ThF sub 4 using the 483.85 keV resonance in the ...

  5. Measurement of axial neutral density profiles in a microwave discharge ion thruster by laser absorption spectroscopy with optical fiber probes.

    Science.gov (United States)

    Tsukizaki, Ryudo; Koizumi, Hiroyuki; Nishiyama, Kazutaka; Kuninaka, Hitoshi

    2011-12-01

    In order to reveal the physical processes taking place within the "μ10" microwave discharge ion thruster, internal plasma diagnosis is indispensable. However, the ability of metallic probes to access microwave plasmas biased at a high voltage is limited from the standpoints of the disturbance created in the electric field and electrical isolation. In this study, the axial density profiles of excited neutral xenon were successfully measured under ion beam acceleration by using a novel laser absorption spectroscopy system. The target of the measurement was metastable Xe I 5p(5)((2)P(0) (3/2))6s[3/2](0) (2) which absorbed a wavelength of 823.16 nm. Signals from laser absorption spectroscopy that swept a single-mode optical fiber probe along the line of sight were differentiated and converted into axial number densities of the metastable neutral particles in the plasma source. These measurements revealed a 10(18) m(-3) order of metastable neutral particles situated in the waveguide, which caused two different modes during the operation of the μ10 thruster. This paper reports a novel spectroscopic measurement system with axial resolution for microwave plasma sources utilizing optical fiber probes.

  6. Shaped Gunpowder Grain Density Detection Device and Technology Solutions%成型药柱密度检测装置及技术方案

    Institute of Scientific and Technical Information of China (English)

    马宏亮

    2016-01-01

    针对密度瓶法、液体静力称量法和标准量筒法等方法的不足,设计一种采用气体法对成型药柱进行密度检测的装置。采用氮气或氦气等惰性气体为中介,渗入试样中极小的空隙和表面的不规则空陷,通过快速精确地测定试样块体积,来实现对成型药柱密度的精确测定。介绍气体法测密度原理,分析装置的组成和功能,给出其工艺流程和相关技术参数。结果表明:该方法灵敏度高、操作方便,可实现自动计算和校正,大大提高工作效率。%In order to overcome the three detection methods defect of density bottle density detection method, hydrostatic weighing density detection method and standard measuring density detection method, design a sealing detection device for testing the shaped gunpowder grain density. Using inert gases such as nitrogen or helium as an intermediary, permeated into the sample in the tiny voids and surface of the irregular air trapping, fast and accurate determination of test piece volume to achieve an accurate determination of explosive forming density, analyze composition and function of the device, give the technological process and technical parameters. The results show that the method has high sensitivity and convenient operation, it can realize the automatic revision of original value, improve work efficiency greatly.

  7. DETECTION OF SINGLE TREE STEMS IN FORESTED AREAS FROM HIGH DENSITY ALS POINT CLOUDS USING 3D SHAPE DESCRIPTORS

    Directory of Open Access Journals (Sweden)

    N. Amiri

    2017-09-01

    Full Text Available Airborne Laser Scanning (ALS is a widespread method for forest mapping and management purposes. While common ALS techniques provide valuable information about the forest canopy and intermediate layers, the point density near the ground may be poor due to dense overstory conditions. The current study highlights a new method for detecting stems of single trees in 3D point clouds obtained from high density ALS with a density of 300 points/m2. Compared to standard ALS data, due to lower flight height (150–200 m this elevated point density leads to more laser reflections from tree stems. In this work, we propose a three-tiered method which works on the point, segment and object levels. First, for each point we calculate the likelihood that it belongs to a tree stem, derived from the radiometric and geometric features of its neighboring points. In the next step, we construct short stem segments based on high-probability stem points, and classify the segments by considering the distribution of points around them as well as their spatial orientation, which encodes the prior knowledge that trees are mainly vertically aligned due to gravity. Finally, we apply hierarchical clustering on the positively classified segments to obtain point sets corresponding to single stems, and perform ℓ1-based orthogonal distance regression to robustly fit lines through each stem point set. The ℓ1-based method is less sensitive to outliers compared to the least square approaches. From the fitted lines, the planimetric tree positions can then be derived. Experiments were performed on two plots from the Hochficht forest in Oberösterreich region located in Austria.We marked a total of 196 reference stems in the point clouds of both plots by visual interpretation. The evaluation of the automatically detected stems showed a classification precision of 0.86 and 0.85, respectively for Plot 1 and 2, with recall values of 0.7 and 0.67.

  8. The co-evolution of total density profiles and central dark matter fractions in simulated early-type galaxies

    Science.gov (United States)

    Remus, Rhea-Silvia; Dolag, Klaus; Naab, Thorsten; Burkert, Andreas; Hirschmann, Michaela; Hoffmann, Tadziu L.; Johansson, Peter H.

    2017-01-01

    We present evidence from cosmological hydrodynamical simulations for a co-evolution of the slope of the total (dark and stellar) mass density profile, γtot, and the dark matter fraction within the half-mass radius, fDM, in early-type galaxies. The relation can be described as γtot = A fDM + B for all systems at all redshifts. The trend is set by the decreasing importance of gas dissipation towards lower redshifts and for more massive systems. Early-type galaxies are smaller, more concentrated, have lower fDM and steeper γtot at high redshifts and at lower masses for a given redshift; fDM and γtot are good indicators for growth by `dry' merging. The values for A and B change distinctively for different feedback models, and this relation can be used as a test for such models. A similar correlation exists between γtot and the stellar mass surface density Σ*. A model with weak stellar feedback and feedback from black holes is in best agreement with observations. All simulations, independent of the assumed feedback model, predict steeper γtot and lower fDM at higher redshifts. While the latter is in agreement with the observed trends, the former is in conflict with lensing observations, which indicate constant or decreasing γtot. This discrepancy is shown to be artificial: the observed trends can be reproduced from the simulations using observational methodology to calculate the total density slopes.

  9. Improving the AGR Fuel Testing Power Density Profile Versus Irradiation-Time in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gray S. Chang; David A. Petti; John T. Maki; Misti A. Lillo

    2009-05-01

    The Very High Temperature gas-cooled Reactor (VHTR), which is currently being developed, achieves simplification of safety through reliance on ceramic-coated fuel particles. Each TRISO-coated fuel particle has its own containment which serves as the principal barrier against radionuclide release under normal operating and accident conditions. These fuel particles, in the form of graphite fuel compacts, are currently undergoing a series of irradiation tests in the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL) to support the Advanced Gas-Cooled Reactor (AGR) fuel qualification program. A representive coated fuel particle with an 235U enrichment of 19.8 wt% was used in this analysis. The fuel burnup analysis tool used to perform the neutronics study reported herein, couples the Monte Carlo transport code MCNP, with the radioactive decay and burnup code ORIGEN2. The fuel burnup methodology known as Monte-Carlo with ORIGEN2 (MCWO) was used to evaluate the AGR experiment assembly and demonstrate compliance with ATR safety requirements. For the AGR graphite fuel compacts, the MCWO-calculated fission power density (FPD) due to neutron fission in 235U is an important design parameter. One of the more important AGR fuel testing requirements is to maintain the peak fuel compact temperature close to 1250°C throughout the proposed irradiation campaign of 550 effective full power days (EFPDs). Based on the MCWO-calculated FPD, a fixed gas gap size was designed to allow regulation of the fuel compact temperatures throughout the entire fuel irradiation campaign by filling the gap with a mixture of helium and neon gases. The chosen fixed gas gap can only regulate the peak fuel compact temperature in the desired range during the irradiation test if the ratio of the peak power density to the time-dependent low power density (P/T) at 550 EFPDs is less than 2.5. However, given the near constant neutron flux within the ATR driver core and the depletion of 235U in

  10. Effect of Cu Content on Atomic Positions of Ti50Ni50−xCux Shape Memory Alloys Based on Density Functional Theory Calculations

    Directory of Open Access Journals (Sweden)

    Liangliang Gou

    2015-11-01

    Full Text Available The study of crystal structures in shape memory alloys is of fundamental importance for understanding the shape memory effect. In order to investigate the mechanism of how Cu content affects martensite crystal structures of TiNiCu alloys, the present research examines the atomic displacement of Ti50Ni50−xCux (x = 0, 5, 12.5, 15, 18.75, 20, 25 shape memory alloys using density functional theory (DFT. By the introduction of Cu atoms into TiNi martensite crystal to replace Ni, the displacements of Ti and Ni/Cu atoms along the x-axis are obvious, but they are minimal along the y- and z-axes. It is found that along the x-axis, the two Ti atoms in the unit cell move in opposite directions, and the same occurred with the two Ni/Cu atoms. With increasing Cu content, the distance between the two Ni/Cu atoms increases while the Ti atoms draw closer along the x-axis, leading to a rotation of the (100 plane, which is responsible for the decrease in the monoclinic angle. It is also found that the displacements of both Ti atoms and Ni/Cu atoms along the x-axis are progressive, which results in a gradual change of monoclinic angle and a transition to B19 martensite crystal structure.

  11. Spin Axes and Shape Models of Asteroid Pairs: Fingerprints of YORP and a Path to the Density of Rubble Piles

    CERN Document Server

    Polishook, David

    2014-01-01

    An asteroid pair consists of two unbound objects with almost identical heliocentric orbital elements that were formed when a single "rubble pile" asteroid failed to remain bound against an increasing rotation rate. Models suggest that the pairs' progenitors gained the fast rotation due to the YORP effect. Since it was shown that the spin axis vector can be aligned by the YORP effect, such a behavior should be seen on asteroid pairs, if they were indeed formed by the described mechanism. Alternatively, if the pairs were formed by a collision, the spin axes should have a random direction and small or young bodies might have a tumbling rotation. Here I apply the lightcurve inversion method on self-obtained photometric data, in order to derive the rotation axis vectors and shape models of the asteroid pairs 2110, 3749, 5026, 6070, 7343 and 44612. Three asteroids resulted with polar-directed spin axes and three objects with ambiguous results. In addition, the secondary member 44612 presents the same sense of rotat...

  12. Inferring Average Ground Profiles of the Muon Density of Inclined Air Showers from Monte-Carlo Simulations at Ultra-High Energy

    CERN Document Server

    Dembinski, Hans; Deligny, Olivier; Hebbeker, Thomas

    2009-01-01

    A standard method to measure ultra-high energy cosmic rays is the sampling of the ground particle profile of the extensive air shower that is produced in the atmosphere with an array of surface detectors. The primary energy of inclined air showers with zenith angles >60 Deg can be reconstructed by using simulated 2-D profiles of the ground density of muons. We will present an effective way to extract such profiles from a library of Monte-Carlo simulated air showers. Also, we will demonstrate a way to speed up the simulation of ground profiles of the muon density in very inclined showers by three orders of magnitude, if only the muon component in the shower is of interest.

  13. Initial measurements of plasma current and electron density profiles using a polarimeter/interferometer (POINT) for long pulse operation in EAST (invited)

    Science.gov (United States)

    Liu, H. Q.; Qian, J. P.; Jie, Y. X.; Ding, W. X.; Brower, D. L.; Zou, Z. Y.; Li, W. M.; Lian, H.; Wang, S. X.; Yang, Y.; Zeng, L.; Lan, T.; Yao, Y.; Hu, L. Q.; Zhang, X. D.; Wan, B. N.

    2016-11-01

    A double-pass, radially viewing, far-infrared laser-based POlarimeter-INTerferometer (POINT) system utilizing the three-wave technique has been implemented for diagnosing the plasma current and electron density profiles in the Experimental Advanced Superconducting Tokamak (EAST). POINT has been operated routinely during the most recent experimental campaign and provides continuous 11 chord line-integrated Faraday effect and density measurement throughout the entire plasma discharge for all heating schemes and all plasma conditions (including ITER relevant scenario development). Reliability of both the polarimetric and interferometric measurements is demonstrated in 25 s plasmas with H-mode and 102 s long-pulse discharges. Current density, safety factor (q), and electron density profiles are reconstructed using equilibrium fitting code (EFIT) with POINT constraints for the plasma core.

  14. Laboratory investigation on the role of tubular shaped micro resonators phononic crystal insertion on the absorption coefficient of profiled sound absorber

    Science.gov (United States)

    Yahya, I.; Kusuma, J. I.; Harjana; Kristiani, R.; Hanina, R.

    2016-02-01

    This paper emphasizes the influence of tubular shaped microresonators phononic crystal insertion on the sound absorption coefficient of profiled sound absorber. A simple cubic and two different bodies centered cubic phononic crystal lattice model were analyzed in a laboratory test procedure. The experiment was conducted by using transfer function based two microphone impedance tube method refer to ASTM E-1050-98. The results show that sound absorption coefficient increase significantly at the mid and high-frequency band (600 - 700 Hz) and (1 - 1.6 kHz) when tubular shaped microresonator phononic crystal inserted into the tested sound absorber element. The increment phenomena related to multi-resonance effect that occurs when sound waves propagate through the phononic crystal lattice model that produce multiple reflections and scattering in mid and high-frequency band which increases the sound absorption coefficient accordingly

  15. THE SIZE, SHAPE, ALBEDO, DENSITY, AND ATMOSPHERIC LIMIT OF TRANSNEPTUNIAN OBJECT (50000) QUAOAR FROM MULTI-CHORD STELLAR OCCULTATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Braga-Ribas, F.; Vieira-Martins, R.; Camargo, J. I. B. [Observatorio Nacional, Rio de Janeiro (Brazil); Sicardy, B.; Lellouch, E.; Lecacheux, J. [Observatoire de Paris, LESIA, F-92195 Meudon (France); Ortiz, J. L.; Morales, N. [Instituto de Astrofisica de Andalucia-CSIC, E-18080 Granada (Spain); Tancredi, G.; Roland, S.; Bruzzone, S. [Observatorio Astronomico Los Molinos, Montevideo U-12400 (Uruguay); Assafin, M. [Observatorio do Valongo/UFRJ, Rio de Janeiro (Brazil); Behrend, R. [Observatoire de Geneve, Sauverny (Switzerland); Vachier, F.; Colas, F. [Observatoire de Paris, IMCCE, F-75014 Paris (France); Maury, A. [San Pedro de Atacama Celestial Explorations, San Pedro de Atacama (Chile); Emilio, M. [Universidade Estadual de Ponta Grossa, Ponta Grossa (Brazil); Amorim, A. [Universidade Federal de Santa Catarina, Florianopolis (Brazil); Unda-Sanzana, E. [Unidad de Astronomia, Universidad de Antofagasta, Antofagasta (Chile); Almeida, L. A., E-mail: ribas@on.br [Instituto Nacional de Pesquisas Espaciais, DAS, Sao Jose dos Campos (Brazil); and others

    2013-08-10

    We present results derived from the first multi-chord stellar occultations by the transneptunian object (50000) Quaoar, observed on 2011 May 4 and 2012 February 17, and from a single-chord occultation observed on 2012 October 15. If the timing of the five chords obtained in 2011 were correct, then Quaoar would possess topographic features (crater or mountain) that would be too large for a body of this mass. An alternative model consists in applying time shifts to some chords to account for possible timing errors. Satisfactory elliptical fits to the chords are then possible, yielding an equivalent radius R{sub equiv} = 555 {+-} 2.5 km and geometric visual albedo p{sub V} = 0.109 {+-} 0.007. Assuming that Quaoar is a Maclaurin spheroid with an indeterminate polar aspect angle, we derive a true oblateness of {epsilon}= 0.087{sup +0.0268}{sub -0.0175}, an equatorial radius of 569{sup +24}{sub -17} km, and a density of 1.99 {+-} 0.46 g cm{sup -3}. The orientation of our preferred solution in the plane of the sky implies that Quaoar's satellite Weywot cannot have an equatorial orbit. Finally, we detect no global atmosphere around Quaoar, considering a pressure upper limit of about 20 nbar for a pure methane atmosphere.

  16. Reinforced Airfoil Shaped Body

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to an airfoil shaped body with a leading edge and a trailing edge extending along the longitudinal extension of the body and defining a profile chord, the airfoil shaped body comprising an airfoil shaped facing that forms the outer surface of the airfoil shaped body...

  17. U-shaped Ladder TEM-Coil Structure with Truncated Sensitivity Profile in z-Direction for High Field MRI

    NARCIS (Netherlands)

    Leussler, C.; Wirtz, D.; Wuelbern, J.H.; Vernickel, P.; Forthmann, P.

    2012-01-01

    Conventional TEM-coils [1] come with a sensitivity profile and field-of view (FOV) that is largely extended in the z-direction comparedwith birdcage coils (BC) [2]. There is an analog situation when comparing TEM coil arrays [3] and degenerate birdcages (DBC) [4]. The excess z-FOV leads to safety is

  18. Profiling of Ionospheric Electron Density Based on FormoSat-3/COSMIC Data: Results from the Intense Observation Period Experiment

    Directory of Open Access Journals (Sweden)

    Lung-Chih Tsai

    2009-01-01

    Full Text Available Multi-channel Global Position System (GPS carrier phase signals received by the FormoSat-3 (FS3/COSMIC program's six low Earth orbiting (LEO satellites were used to undertake active limb sounding of the Earth¡¦s atmosphere and ionosphere via radio occultation (RO. In this study, the effects of large-scale horizontal gradients and/or inhomogeneous ionospheric electron densities (ne were considered by developing an iterative scheme to determine "compensated" total electron content (TEC values through nearby occultation observations. Using an iterative Abel inversion through "compensated" TEC values, more than one-hundred and eighty thousand vertical ionospheric ne profiles were collected during the intense observation period (IOP of 20 June - 27 September (day number 171 to 270 2006. Coincidences of GPS RO observations to ionospheric ne ionosonde data from forty-nine worldwide stations have been examined. It is found that the iterative scheme gives improved retrievals over the standard Abel inversion. From several thousand matches within the IOP experiment, the root mean square (rms foF2 differences between the ionosonde measurements and the FS3/COSMIC retrievals are improved from 1.67 to 1.07 MHz. The results also show improvement in the overestimates (underestimates on low (high retrieved foF2s, while the obtained hmF2s give better agreement with ionosonde observations.

  19. Hydrolysis Profiles of Formalin Fixed Paraffin-Embedded Tumors Based on IOD (Integrated Optical Density and Nuclear Texture Feature Measurements

    Directory of Open Access Journals (Sweden)

    Margareta Fležar

    1999-01-01

    Full Text Available The aim of the study was to determine optimal hydrolysis time for the Feulgen DNA staining of archival formalin fixed paraffin‐embedded surgical samples, prepared as single cell suspensions for image cytometric measurements. The nuclear texture features along with the IOD (integrated optical density of the tumor nuclei were analysed by an automated high resolution image cytometer as a function of duration of hydrolysis treatment (in 5 N HCl at room temperature. Tissue blocks of breast carcinoma, ovarian serous carcinoma, ovarian serous tumor of borderline malignancy and leiomyosarcoma were included in the study. IOD hydrolysis profiles showed plateau between 30 and 60 min in the breast carcinoma and leiomyosarcoma, and between 40 and 60 min in the ovarian serous carcinoma and ovarian serous tumor of borderline malignancy. Most of the nuclear texture features remained stable after 20 min of hydrolysis treatment. Our results indicate that the optimal hydrolysis time for IOD and for nuclear texture feature measurements, was between 40 and 60 min in the cell preparations from tissue blocks of three epithelial and one soft tissue tumor.

  20. Quantification of mid and late evoked sinks in laminar current source density profiles of columns in the primary auditory cortex.

    Science.gov (United States)

    Schaefer, Markus K; Hechavarría, Julio C; Kössl, Manfred

    2015-01-01

    Current source density (CSD) analysis assesses spatiotemporal synaptic activations at somatic and/or dendritic levels in the form of depolarizing current sinks. Whereas many studies have focused on the short (primary auditory cortex of Mongolian gerbils. By applying an algorithm for contour calculation, three distinct mid and four late evoked sinks were identified in layers I, III, Va, VIa, and VIb. Our results further showed that the patterns of intracortical information-flow remained qualitatively similar for low and for high sound pressure level stimuli at the characteristic frequency (CF) as well as for stimuli ± 1 octave from CF. There were, however, differences associated with the strength, vertical extent, onset latency, and duration of the sinks for the four stimulation paradigms used. Stimuli one octave above the most sensitive frequency evoked a new, and quite reliable, sink in layer Va whereas low level stimulation led to the disappearance of the layer VIb sink. These data indicate the presence of input sources specifically activated in response to level and/or frequency parameters. Furthermore, spectral integration above vs. below the CF of neurons is asymmetric as illustrated by CSD profiles. These results are important because synaptic feedback associated with mid and late sinks-beginning at 50 ms post stimulus latency-is likely crucial for response modulation resulting from higher order processes like memory, learning or cognitive control.

  1. Size- and shape-dependent polarizabilities of sandwich and rice-ball Co(n)Bz(m) clusters from density functional theory.

    Science.gov (United States)

    Wang, Jinlan; Zhu, Liyan; Zhang, Xiuyun; Yang, Mingli

    2008-09-11

    The dipole polarizabilities of Co(n)Bz(m), (n, m = 1-4, m = n, n + 1) clusters are studied by means of an all-electron gradient-corrected density functional theory and finite field method. The dipole moments are relatively large for most of the clusters, implying their asymmetric structures. The total polarizability increases rapidly as cluster size, whereas the average polarizability shows "odd-even" oscillation with relatively large values at (n, n + 1). The polarizabilities exhibit clear shape-dependent variation, and the sandwich structures have systematically larger polarizability and anisotropy than the rice-ball isomers. The dipole polarizabilities are further analyzed in terms of the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap, ionization potential, and electron delocalization volume. We conclude that the polarizability variations are determined by the interplay between the geometrical and electronic properties of the clusters.

  2. Water temperature, salinity, and density profiles collected by CTD from multiple cruises in the Northeast Pacific Ocean, the Bering Sea, and the Gulf of Alaska from 2001-01 to 2001-10 (NCEI Accession 0001112)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and density profiles were collected using CTD from NOAA Ship MILLER FREEMAN, NOAA Ship RONALD H. BROWN, and SIR WILFRED LAURIER in the Northeast...

  3. Reconstructing the 3D shape and bone mineral density distribution of the proximal femur from dual-energy X-ray absorptiometry.

    Science.gov (United States)

    Whitmarsh, Tristan; Humbert, Ludovic; De Craene, Mathieu; Del Rio Barquero, Luis M; Frangi, Alejandro F

    2011-12-01

    The accurate diagnosis of osteoporosis has gained increasing importance due to the aging of our society. Areal bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) is an established criterion in the diagnosis of osteoporosis. This measure, however, is limited by its two-dimensionality. This work presents a method to reconstruct both the 3D bone shape and 3D BMD distribution of the proximal femur from a single DXA image used in clinical routine. A statistical model of the combined shape and BMD distribution is presented, together with a method for its construction from a set of quantitative computed tomography (QCT) scans. A reconstruction is acquired in an intensity based 3D-2D registration process whereby an instance of the model is found that maximizes the similarity between its projection and the DXA image. Reconstruction experiments were performed on the DXA images of 30 subjects, with a model constructed from a database of QCT scans of 85 subjects. The accuracy was evaluated by comparing the reconstructions with the same subject QCT scans. The method presented here can potentially improve the diagnosis of osteoporosis and fracture risk assessment from the low radiation dose and low cost DXA devices currently used in clinical routine.

  4. Effect of Cross-linking Density on Creep and Recovery Behavior in Epoxy-Based Shape Memory Polymers (SMEPs) for Structural Applications

    Science.gov (United States)

    Rao, Kavitha V.; Ananthapadmanabha, G. S.; Dayananda, G. N.

    2016-12-01

    Epoxy-based shape memory polymers (SMEPs) are gaining importance in the area of aerospace structures due to their high strength and stiffness which is a primary requirement for an SMEP in structural applications. The understanding of viscoelastic behavior of SMEPs is very essential to assess their shape memory effect. In the present work, three types of SMEPs with varying cross-linking densities were developed by curing an aromatic epoxy resin with aliphatic amines. Glass transition temperature ( T g) was measured for these SMEPs using advanced rheometric expansion system, and from the T g measurements, a range of temperatures from glassy to rubbery regimes were chosen. At selected temperatures, creep-recovery tests were performed in order to evaluate the viscoelastic behavior of SMEPs and also to investigate the effect of temperature on creep-recovery. Further, a three-parameter viscoelastic model (Zener) was used to fit the data obtained from experiments. Model parameters like moduli of the springs and viscosity of the dashpot were evaluated by curve fitting. Results revealed that Zener model was well suited to describe the viscoelastic behavior of SMEPs as a function of test temperatures.

  5. Steady-state solutions for subsurface chlorophyll maximum in stratified water columns with a bell-shape vertical profile of chlorophyll

    Directory of Open Access Journals (Sweden)

    X. Gong

    2014-06-01

    Full Text Available A bell-shape vertical profile of chlorophyll a (Chl a concentration, conventionally referred as Subsurface Chlorophyll Maximum (SCM phenomenon, has frequently been observed in stratified oceans and lakes. This profile is assumed to be a general Gaussian distribution in this study. By substituting the general Gaussian function into ecosystem dynamical equations, the steady-state solutions for SCM characteristics (i.e. SCM layer depth, thickness, and intensity in various scenarios are derived. These solutions indicate that: (1 The maximum in Chl a concentrations occurs at or below the depth with the maximum in growth rates of phytoplankton locating at the transition from nutrient limitation to light limitation, and the depth of SCM layer deepens logarithmically with an increase in surface light intensity; (2 The shape of SCM layer (thickness and intensity is mainly influenced by nutrient supply, but independence of surface light intensity; (3 The intensity of SCM layer is proportional to the diffusive flux of nutrient from below, getting stronger as a result of this layer being shrank by a higher light attenuation coefficient or a larger sinking velocity of phytoplankton. The analytical solutions can be useful to estimate environmental parameters difficultly obtained from on-site observations.

  6. Monitoring of the mass density profile along the 0° geomagnetic longitude during magnetic storms with the use of ground magnetometers.

    Science.gov (United States)

    Romanova, N.; Stepanova, M. V.; Kozyreva, O. V.; Pilipenko, V.; Zesta, E.

    2015-12-01

    Ground magnetometers offer a very cheap and robust means of globally monitoring the magnetospheric mass density, by determining the ULF field line resonant frequency. ULF waves are almost always present in near-Earth environment and are generated by the solar wind interaction with the terrestrial magnetosphere. These waves from the magnetopause propagate through the magnetosphere. When they encounter a field line that resonates at the same frequency, coupling to the Alfven field line oscillations occurs and the resonance can be detected on the ground at that particular latitude. There are different methods for determining resonant frequencies from ground ULF waves. the density profiles along the 0° geomagnetic longitude were obtained using both the gradient and the amplitude-phase methods for the analysis of the magnetic field data from the magnetometer arrays: SAMBA (South American Meridional B-field Array), MAGDAS and American Antarctic bases (Palmer, WAIS-D). We compared the density profiles during quiet magnetic conditions and during strong magnetic storms (recovery phase). It is shown that in the recovery phase of strong magnetic storms (Dst <-150 nT) profile of the equatorial mass density varies greatly in comparison with the density distribution in quiet days.

  7. CLASH-VLT: The mass, velocity-anisotropy, and pseudo-phase-space density profiles of the z=0.44 galaxy cluster MACS 1206.2-0847

    CERN Document Server

    Biviano, A; Balestra, I; Mercurio, A; Girardi, M; Nonino, M; Grillo, C; Scodeggio, M; Lemze, D; Kelson, D; Umetsu, K; Postman, M; Zitrin, A; Czoske, O; Ettori, S; Lombardi, M; Maier, C; Medezinski, E; Mei, S; Presotto, V; Tozzi, P; Ziegler, B; Annunziatella, M; Bartelmann, M; Benitez, N; Bradley, L; Brescia, M; Broadhurst, T; Coe, D; Demarco, R; Donahue, M; Ford, H; Gobat, R; Graves, G; Koekemoer, A; Kuchner, U; Melchior, P; Meneghetti, M; Merten, J; Moustakas, L; Munari, E; Regos, E; Sartoris, B; Seitz, S; Zheng, W

    2013-01-01

    We use an unprecedented data-set of about 600 redshifts for cluster members, obtained as part of a VLT/VIMOS large programme, to constrain the mass profile of the z=0.44 cluster MACS J1206.2-0847 over the radial range 0-5 Mpc (0-2.5 virial radii) using the MAMPOSSt and Caustic methods. We then add external constraints from the gravitational lensing analysis of Umetsu et al. (2012). We invert the Jeans equation to obtain the velocity-anisotropy profiles of cluster members. With the mass-density and velocity-anisotropy profiles we then obtain the first determination of a cluster pseudo-phase-space density profile. The kinematics and lensing determinations of the cluster mass profile are in excellent agreement. This is very well fitted by a NFW model with mass M200=(1.4 +- 0.2) 10^15 Msun and concentration c200=6 +- 1, only slightly higher than theoretical expectations. Other mass profile models also provide acceptable fits to our data, of (slightly) lower (Burkert, Hernquist, and Softened Isothermal Sphere) or ...

  8. A constant limiting mass scale for flat early-type galaxies from z=1 to z=0: density evolves but shapes do not

    CERN Document Server

    Holden, Bradford; Rix, Hans-Walter; Franx, Marijn

    2011-01-01

    We measure the evolution in the intrinsic shape distribution of early-type galaxies from z~1 to z~0 by analyzing their projected axis-ratio distributions. We extract a low-redshift sample (0.04 1e11 M_sun) is 2:3, where as at masses below 1e11 M_sun this ratio narrows to 1:3, or more flattened galaxies. In an entirely analogous manner we select a high-redshift sample (0.6 3e10 M_sun with redshift. At the same time, our samples imply an increase of 2-3x in co-moving number density for early-type galaxies at masses >3e10 M_sun, in agreement with previous studies. Given the direct connection between the axis-ratio distribution and the underlying bulge-to-disk ratio distribution, our findings imply that the number density evolution of early-type galaxies is not exclusively driven by the emergence of either bulge- or disk-dominated galaxies, but rather by a balanced mix that depends only on the stellar mass of the galaxy. The challenge for galaxy formation models is to reproduce this overall non-evolving ratio of ...

  9. Time-Dependent Density Functional Theory Study of Low-Lying Absorption and Fluorescence Band Shapes for Phenylene-Containing Oligoacenes.

    Science.gov (United States)

    Jun, Ye

    2015-12-24

    Low-lying band shapes of absorption and fluorescence spectra for a member of a newly synthesized family of phenylene-containing oligoacenes (POA 6) reported in J. Am. Chem. Soc. 2012 , 134 , 15351 are studied theoretically with two different approaches with TIPS-anthracene as a comparison. Underlying photophysics and exciton-phonon interactions in both molecules are investigated in details with the aid of the time-dependent density functional theory and multimode Brownian oscillator model. The first two low-lying excited-states of POA 6 were found to exhibit excitation characteristics spanning entire conjugated backbone despite the presence of antiaromatic phenylene section. Absorption and fluorescence spectra calculated from both time-dependent density functional theory and multimode Brownian oscillator model are shown to reach good agreement with experimental ones. The coupling between phonon modes and optical transitions is generally weak as suggested by the multimode Brownian oscillator model. Broader peaks of POA 6 spectra are found to relate to stronger coupling between low frequency phonon modes such as backbone twisting (with frequency <300 cm(-1)) and optical transitions. Furthermore, POA 6 exhibits weaker exciton-phonon coupling for the phonon modes above 1000 cm(-1) compared to TIPS-anthracene owing to extended conjugated backbone. A significant coupling between an in-plane breathing mode localized around the antiaromatic phenylene segment with frequency at 1687 cm(-1) and optical transitions for the first two excited-states of POA 6 is also observed.

  10. Direct Growth of Carbon Nanotubes on New High-Density 3D Pyramid-Shaped Microelectrode Arrays for Brain-Machine Interfaces

    Directory of Open Access Journals (Sweden)

    Bahareh Ghane Motlagh

    2016-09-01

    Full Text Available Silicon micromachined, high-density, pyramid-shaped neural microelectrode arrays (MEAs have been designed and fabricated for intracortical 3D recording and stimulation. The novel architecture of this MEA has made it unique among the currently available micromachined electrode arrays, as it has provided higher density contacts between the electrodes and targeted neural tissue facilitating recording from different depths of the brain. Our novel masking technique enhances uniform tip-exposure for variable-height electrodes and improves process time and cost significantly. The tips of the electrodes have been coated with platinum (Pt. We have reported for the first time a selective direct growth of carbon nanotubes (CNTs on the tips of 3D MEAs using the Pt coating as a catalyzer. The average impedance of the CNT-coated electrodes at 1 kHz is 14 kΩ. The CNT coating led to a 5-fold decrease of the impedance and a 600-fold increase in charge transfer compared with the Pt electrode.

  11. Utilization of star-shaped polymer architecture in the creation of high-density polymer brush coatings for the prevention of platelet and bacteria adhesion

    Science.gov (United States)

    Totani, Masayasu; Terada, Kayo; Terashima, Takaya; Kim, Ill Yong; Ohtsuki, Chikara; Xi, Chuanwu; Tanihara, Masao

    2014-01-01

    We demonstrate utilization of star-shaped polymers as high-density polymer brush coatings and their effectiveness to inhibit the adhesion of platelets and bacteria. Star polymers consisting of poly(2-hydroxyethyl methacrylate) (PHEMA) and/or poly(methyl methacrylate) (PMMA), were synthesized using living radical polymerization with a ruthenium catalyst. The polymer coatings were prepared by simple drop casting of the polymer solution onto poly(ethylene terephthalate) (PET) surfaces and then dried. Among the star polymers prepared in this study, the PHEMA star polymer (star-PHEMA) and the PHEMA/PMMA (mol. ratio of 71/29) heteroarm star polymer (star-H71M29) coatings showed the highest percentage of inhibition against platelet adhesion (78–88% relative to noncoated PET surface) and Escherichia coli (94–97%). These coatings also showed anti-adhesion activity against platelets after incubation in Dulbecco's phosphate buffered saline or surfactant solution for 7 days. In addition, the PMMA component of the star polymers increased the scratch resistance of the coating. These results indicate that the star-polymer architecture provides high polymer chain density on PET surfaces to prevent adhesion of platelets and bacteria, as well as coating stability and physical durability to prevent exposure of bare PET surfaces. The star polymers provide a simple and effective approach to preparing anti-adhesion polymer coatings on biomedical materials against the adhesion of platelets and bacteria. PMID:25485105

  12. Influence of soft ferromagnetic sections on the magnetic flux density profile of a large grain, bulk Y-Ba-Cu-O superconductor

    OpenAIRE

    Philippe, Matthieu; Ainslie, Mark D.; Wera, Laurent; Fagnard, Jean-François; Dennis, Anthony; Shi, Yunhua; Cardwell, David A.; Vanderheyden, Benoît; Vanderbemden, Philippe

    2015-01-01

    Bulk, high temperature superconductors have significant potential for use as powerful permanent magnets in a variety of practical applications due to their ability to trap record magnetic fields. In this paper, soft ferromagnetic sections are combined with a bulk, large grain Y-Ba-Cu-O (YBCO) high temperature superconductor to form superconductor/ferromagnet (SC/FM) hybrid structures. We study how the ferromagnetic sections influence the shape of the profile of the trapped magnetic induction ...

  13. Measurement of deuterium density profiles in the H-mode steep gradient region using charge exchange recombination spectroscopy on DIII-D

    Science.gov (United States)

    Haskey, S. R.; Grierson, B. A.; Burrell, K. H.; Chrystal, C.; Groebner, R. J.; Kaplan, D. H.; Pablant, N. A.; Stagner, L.

    2016-11-01

    Recent completion of a thirty two channel main-ion (deuterium) charge exchange recombination spectroscopy (CER) diagnostic on the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] enables detailed comparisons between impurity and main-ion temperature, density, and toroidal rotation. In a H-mode DIII-D discharge, these new measurement capabilities are used to provide the deuterium density profile, demonstrate the importance of profile alignment between Thomson scattering and CER diagnostics, and aid in determining the electron temperature at the separatrix. Sixteen sightlines cover the core of the plasma and another sixteen are densely packed towards the plasma edge, providing high resolution measurements across the pedestal and steep gradient region in H-mode plasmas. Extracting useful physical quantities such as deuterium density is challenging due to multiple photoemission processes. These challenges are overcome using a detailed fitting model and by forward modeling the photoemission using the FIDASIM code, which implements a comprehensive collisional radiative model.

  14. Classification of X-ray solar flares regarding their effects on the lower ionosphere electron density profile

    Directory of Open Access Journals (Sweden)

    D. P. Grubor

    2008-06-01

    Full Text Available The classification of X-ray solar flares is performed regarding their effects on the Very Low Frequency (VLF wave propagation along the Earth-ionosphere waveguide. The changes in propagation are detected from an observed VLF signal phase and amplitude perturbations, taking place during X-ray solar flares. All flare effects chosen for the analysis are recorded by the Absolute Phase and Amplitude Logger (AbsPal, during the summer months of 2004–2007, on the single trace, Skelton (54.72 N, 2.88 W to Belgrade (44.85 N, 20.38 E with a distance along the Great Circle Path (GCP D≈2000 km in length.

    The observed VLF amplitude and phase perturbations are simulated by the computer program Long-Wavelength Propagation Capability (LWPC, using Wait's model of the lower ionosphere, as determined by two parameters: the sharpness (β in 1/km and reflection height (H' in km. By varying the values of β and H' so as to match the observed amplitude and phase perturbations, the variation of the D-region electron density height profile Ne(z was reconstructed, throughout flare duration. The procedure is illustrated as applied to a series of flares, from class C to M5 (5×10−5 W/m2 at 0.1–0.8 nm, each giving rise to a different time development of signal perturbation.

    The corresponding change in electron density from the unperturbed value at the unperturbed reflection height, i.e. Ne(74 km=2.16×108 m−3 to the value induced by an M5 class flare, up to Ne(74 km=4×1010 m−3 is obtained. The β parameter is found to range from 0.30–0.49 1/km and the reflection height H' to vary from 74–63 km. The changes in Ne(z during the flares, within height range z=60 to 90 km are determined, as well.

  15. Characterization of the acidic and basic limbs of a bell-shaped pH profile in the inhibitory activity of bromelain inhibitor VI.

    Science.gov (United States)

    Hatano, Ken-ichi; Sawano, Yoriko; Miyakawa, Takuya; Tanokura, Masaru

    2006-03-01

    Bromelain inhibitor VI (BI-VI) is a cysteine proteinase inhibitor from pineapple stem and a unique two-chain inhibitor composed of two distinct domains. BI-VI's inhibitory activity toward the target enzyme bromelain is maximal at pH 4 and shows a bell-shaped pH profile with pKa values of about 2.5 and 5.3. This pH profile is quite different from that of bromelain, which is optimally active around pH 7. In the present article, to characterize the acidic limb, we first expressed the recombinant inhibitors designed to lose two putative hydrogen bonds of Ser7(NH)-Asp28(beta-CO2H) and Lys38(NH)-Asp51(beta-CO2H) and confirmed the existence of the hydrogen bonds by two-dimensional nuclear magnetic resonance (NMR). Moreover, it was revealed that these hydrogen bonds are not the essential electrostatic factor and some ionizable groups would be responsible for the acidic limb in the pH-inhibition profile. On the other hand, to characterize the basic limb, we examined the pH-dependent inhibition using the cysteine proteinase papain, some of whose properties differ from those of bromelain, and compared the data with the corresponding data for bromelain. The result suggests that the basic limb would be affected by some electrostatic factors, probably some carboxyl groups in the target proteinase.

  16. Atomic force microscopy and cells: Indentation profiles around the AFM tip, cell shape changes, and other examples of experimental factors affecting modeling.

    Science.gov (United States)

    Melzak, Kathryn A; Toca-Herrera, José L

    2015-07-01

    We use atomic force microscopy in conjunction with a fluorescence microscope capable of optical sectioning to acquire images of white blood cells while force is applied with the AFM tip. The indentation profile within the cell is compared to the profile of the AFM tip: examples are shown for indentations at the center of the cell which are reasonable matches to the tip profile, and an additional example is shown for an indentation that is on the tilted side of a highly rounded cell and that differs from the tip shape. We also demonstrate that the AFM tip can interact with internal cell structures, we show that the contact area between the cell and the substrate can increase under applied pressure, that the main body of the cell can fuse with the extended lamellipodium, and that the cell can be displaced laterally by the AFM tip. The features illustrated here are relevant to the interpretation of indentation experiments that measure cell elasticity properties, as is discussed briefly.

  17. From slant column densities to trace gas profiles: Post processing data from the new MAX-DOAS network in Mexico City

    Science.gov (United States)

    Friedrich, M. M.; Stremme, W.; Rivera, C. I.; Arellano, E. J.; Grutter, M.

    2014-12-01

    The new MAX-DOAS network in Mexico City provides results of O4, HCHO and NO2 slant column densities (SCD). Here, we present a new numerical code developed to retrieve gas profiles of NO2 and HCHO using radiative transfer simulations. We present first results of such profiles from the MAX-DOAS station located at UNAM campus. The code works in two steps: First, the O4 slant column density information is used to retrieve an aerosol profile. As an a-priori aerosol profile, we use averaged ceilometer data measured at UNAM and scaled to the total optical depth provided by the Aeronet data base. In the second step, the retrieved aerosol profile information is used together with the trace gas (HCHO or NO2) SCDs to retrieve the trace gas profiles. The inversion is based on a gauss-newton iteration scheme and uses constrained least square fitting with either optimal estimation or Tihkonov regularization. For the latter, the regulation matrix is currently constructed from the discrete first derivative operator. The forward model uses the radiative transfer code VLIDORT. The inputs to VLIDORT are calculated using temperature and pressure information from daily radiosounde measurements and aerosol single scattering optical depths and asymmetry factors from the Aeronet data base for Mexico City. For the gas absorption cross sections we use the same values as were used for the SCD calculation from the recorded spectra using QDOAS. Besides demonstrating the functionality of the algorithm showing profile retrievals of simulated SCDs with added random noise, we present HCHO and NO2 profiles retrieved from SCDs calculated from the MAX-DOAS measurements at UNAM campus at selected days.

  18. High-Resolution Profiling of Drosophila Replication Start Sites Reveals a DNA Shape and Chromatin Signature of Metazoan Origins

    Directory of Open Access Journals (Sweden)

    Federico Comoglio

    2015-05-01

    Full Text Available At every cell cycle, faithful inheritance of metazoan genomes requires the concerted activation of thousands of DNA replication origins. However, the genetic and chromatin features defining metazoan replication start sites remain largely unknown. Here, we delineate the origin repertoire of the Drosophila genome at high resolution. We address the role of origin-proximal G-quadruplexes and suggest that they transiently stall replication forks in vivo. We dissect the chromatin configuration of replication origins and identify a rich spatial organization of chromatin features at initiation sites. DNA shape and chromatin configurations, not strict sequence motifs, mark and predict origins in higher eukaryotes. We further examine the link between transcription and origin firing and reveal that modulation of origin activity across cell types is intimately linked to cell-type-specific transcriptional programs. Our study unravels conserved origin features and provides unique insights into the relationship among DNA topology, chromatin, transcription, and replication initiation across metazoa.

  19. High-resolution profiling of Drosophila replication start sites reveals a DNA shape and chromatin signature of metazoan origins.

    Science.gov (United States)

    Comoglio, Federico; Schlumpf, Tommy; Schmid, Virginia; Rohs, Remo; Beisel, Christian; Paro, Renato

    2015-05-05

    At every cell cycle, faithful inheritance of metazoan genomes requires the concerted activation of thousands of DNA replication origins. However, the genetic and chromatin features defining metazoan replication start sites remain largely unknown. Here, we delineate the origin repertoire of the Drosophila genome at high resolution. We address the role of origin-proximal G-quadruplexes and suggest that they transiently stall replication forks in vivo. We dissect the chromatin configuration of replication origins and identify a rich spatial organization of chromatin features at initiation sites. DNA shape and chromatin configurations, not strict sequence motifs, mark and predict origins in higher eukaryotes. We further examine the link between transcription and origin firing and reveal that modulation of origin activity across cell types is intimately linked to cell-type-specific transcriptional programs. Our study unravels conserved origin features and provides unique insights into the relationship among DNA topology, chromatin, transcription, and replication initiation across metazoa.

  20. Characterization of Electron Temperature and Density Profiles of Plasmas Produced by Nike KrF Laser for Laser Plasma Instability (LPI) Research

    Science.gov (United States)

    Oh, Jaechul; Weaver, J. L.; Phillips, L.; Obenschain, S. P.; Schmitt, A. J.; Kehne, D. M.; Chan, L.-Y.; Serlin, V.

    2011-10-01

    Previous experiments with Nike KrF laser (λ = 248 nm , Δν ~ 1 THz) observed LPI signatures near quarter critical density (nc / 4) in CH plasmas, however, detailed measurement of the temperature (Te) and density (ne) profiles was missing. The current Nike LPI campaign will perform experimental determination of the plasma profiles. A side-on grid imaging refractometer (GIR) is the main diagnostic to resolve Te and ne in space taking 2D snapshots of probe laser (λ = 266 nm , Δt = 8 psec) beamlets (50 μm spacing) refracted by the plasma at laser peak time. Ray tracing of the beamlets through hydrodynamically simulated (FASTRAD3D) plasma profiles estimates the refractometer may access densities up to ~ 0 . 2nc . With the measured Te and ne profiles in the plasma corona, we will discuss analysis of light data radiated from the plasmas in spectral ranges relevant to two plasmon decay and convective Raman instabilities. Validity of the (Te ,ne) data will also be discussed for the thermal transport study. Work supported by DoE/NNSA and ONR and performed at NRL.

  1. 3D stellar kinematics at the Galactic center: measuring the nuclear star cluster spatial density profile, black hole mass, and distance

    CERN Document Server

    Do, T; Yelda, S; Ghez, A M; Bullock, J; Kaplinghat, M; Lu, J R; Peter, A G H; Phifer, K

    2013-01-01

    We present 3D kinematic observations of stars within the central 0.5 pc of the Milky Way nuclear star cluster using adaptive optics imaging and spectroscopy from the Keck telescopes. Recent observations have shown that the cluster has a shallower surface density profile than expected for a dynamically relaxed cusp, leading to important implications for its formation and evolution. However, the true three dimensional profile of the cluster is unknown due to the difficulty in de-projecting the stellar number counts. Here, we use spherical Jeans modeling of individual proper motions and radial velocities to constrain for the first time, the de-projected spatial density profile, cluster velocity anisotropy, black hole mass ($M_\\mathrm{BH}$), and distance to the Galactic center ($R_0$) simultaneously. We find that the inner stellar density profile of the late-type stars, $\\rho(r)\\propto r^{-\\gamma}$ to have a power law slope $\\gamma=0.05_{-0.60}^{+0.29}$, much more shallow than the frequently assumed Bahcall $\\&am...

  2. Biases of CO2 Storage in Eddy Flux Measurements pertinent to Vertical Configurations of a Profile System and CO2 Density Averaging

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Bai [ORNL; Hanson, Paul J [ORNL; Riggs, Jeffery S [ORNL; Pallardy, Stephen G. [University of Missouri; Hosman, K. P. [University of Missouri; Meyers, T. P. [NOAA ATDD; Wullschleger, Stan D [ORNL; Gu, Lianhong [ORNL; Heuer, Mark [ATDD, NOAA

    2007-01-01

    CO2 storage in a 30-minute period in a tall forest canopy often makes significant contributions to net ecosystem exchange (NEE) in the early morning and at night. When CO2 storage is properly measured and taken into account, underestimations of NEE on calm nights can be greatly reduced. Using CO2 data from a 12-level profile, we demonstrate that the lower canopy layer (below the thermal inversion) is a disproportional contributor to the total CO2 storage. This is because time derivative of CO2 density ( c/ t) generally shows increasing magnitude of mean and standard deviation with decreasing heights at night and from sunrise to 1000 hr in both growing and dormant seasons. Effects of resolution and configuration in a profiling system on the accuracy of CO2 storage estimation are evaluated by comparing subset profiles to the 12-level benchmark profile. It is demonstrated that the effectiveness of a profiling system in estimating CO2 storage is not only determined by its number of sampling levels but, more importantly, by its vertical configuration. To optimize a profile, one needs to balance the influence of two factors, c/ t and layer thickness, among all vertical sections within a forest. As a key contributor to the total CO2 storage, the lower canopy (with relatively large means and standard deviations of c/ t) requires a higher resolution in a profile system than the layers above. However, if the upper canopy is over-sparsely sampled relative to the lower canopy, the performance of a profile system might be degraded since, in such a situation, the influence of layer thickness dominates over that of c/ t. We also find that, because of different level of complexity in canopy structure, more sampling levels are necessary at our site in order to achieve the same level of accuracy as at a boreal aspen site. These results suggest that, in order to achieve an adequate accuracy in CO2 storage measurements, the number of sampling levels in a profile and its design should

  3. A gravity study along a profile across the Sichuan Basin, the Qinling Mountains and the Ordos Basin (central China): Density, isostasy and dynamics

    Science.gov (United States)

    Zhang, Yongqian; Teng, Jiwen; Wang, Qianshen; Lü, Qingtian; Si, Xiang; Xu, Tao; Badal, José; Yan, Jiayong; Hao, Zhaobing

    2017-10-01

    In order to investigate the structure of the crust beneath the Middle Qinling Mountains (MQL) and neighboring areas in the North China Block and South China Block, a north-south gravity profile from Yuquan in the Sichuan Basin to Yulin in the Ordos Basin was conducted in 2011. The Bouguer gravity anomaly is determined from a high-quality gravity dataset collected between 31°N and 36°N of latitude, and varies between -200 and -110 mGal in the study region. Using accredited velocity density relationships, an initial crust-mantle density model is constructed for MQL and adjacent areas, which is later refined interactively to simulate the observed gravity anomaly. The present study reveals the features of the density and Bouguer gravity with respect to the tectonic units sampled by the profile. The lithosphere density model shows typical density values that depict a layered structure and allow differentiate the blocks that extend along the reference profile. The gravity field calculated by forward modeling from the final density distribution model correlates well with the measured gravity field within a standard deviation of 1.26 mGal. The density in the crystalline crust increases with depth from 2.65 g/cm3 up to the highest value of 2.95 g/cm3 near the bottom of the crust. The Conrad interface is identified as a density jump of about 0.05 g/cm3. The average density of the crust in MQL is clearly lower than the density in the formations on both sides. Starting from a combined Airy-Pratt isostatic compensation model, a partly compensated crust is found below MQL, suggesting future growth of the crust, unlike the Ordos and Sichuan basins that will remain stable. On the basis of the density and isostatic state of the crust and additional seismological research, such as the P-wave velocity model and Poisson's ratio, it is concluded that the lower crust delamination is a reasonable interpretation for the geophysical characteristics below the Qinling Orogen.

  4. Mysteries of LiF TLD response following high ionisation density irradiation: nanodosimetry and track structure theory, dose response and glow curve shapes.

    Science.gov (United States)

    Horowitz, Y; Fuks, E; Datz, H; Oster, L; Livingstone, J; Rosenfeld, A

    2011-06-01

    Three outstanding effects of ionisation density on the thermoluminescence (TL) mechanisms giving rise to the glow peaks of LiF:Mg,Ti (TLD-100) are currently under investigation: (1) the dependence of the heavy charged particle (HCP) relative efficiency with increasing ionisation density and the effectiveness of its modelling by track structure theory (TST), (2) the behaviour of the TL efficiency, f(D), as a function of photon energy and dose. These studies are intended to promote the development of a firm theoretical basis for the evaluation of relative TL efficiencies to assist in their application in mixed radiation fields. And (3) the shape of composite peak 5 in the glow curve for various HCP types and energies and following high-dose electron irradiation, i.e. the ratio of the intensity of peak 5a to peak 5. Peak 5a is a low-temperature satellite of peak 5 arising from electron-hole capture in a spatially correlated trapping centre/luminescent centre (TC/LC) complex that has been suggested to possess a potential as a solid-state nanodosemeter due to the preferential electron/hole population of the TC/LC at high ionisation density. It is concluded that (1) the predictions of TST are very strongly dependent on the choice of photon energy used in the determination of f(D); (2) modified TST employing calculated values of f(D) at 2 keV is in agreement with 5-MeV alpha particle experimental results for composite peak 5 but underestimates the 1.5-MeV proton relative efficiencies. Both the proton and alpha particle relative TL efficiencies of the high-temperature TL (HTTL) peaks 7 and 8 are underestimated by an order of magnitude suggesting that the HTTL efficiencies are affected by other factors in addition to radial electron dose; (3) the dose-response supralinearity of peaks 7 and 8 change rapidly with photon energy: this behaviour is explained in the framework of the unified interaction model as due to a very strong dependence on photon energy of the relative

  5. Menadione-Induced Oxidative Stress Re-Shapes the Oxylipin Profile of Aspergillus flavus and Its Lifestyle

    Directory of Open Access Journals (Sweden)

    Marco Zaccaria

    2015-10-01

    Full Text Available Aspergillus flavus is an efficient producer of mycotoxins, particularly aflatoxin B1, probably the most hepatocarcinogenic naturally-occurring compound. Although the inducing agents of toxin synthesis are not unanimously identified, there is evidence that oxidative stress is one of the main actors in play. In our study, we use menadione, a quinone extensively implemented in studies on ROS response in animal cells, for causing stress to A. flavus. For uncovering the molecular determinants that drive A. flavus in challenging oxidative stress conditions, we have evaluated a wide spectrum of several different parameters, ranging from metabolic (ROS and oxylipin profile to transcriptional analysis (RNA-seq. There emerges a scenario in which A. flavus activates several metabolic processes under oxidative stress conditions for limiting the ROS-associated detrimental effects, as well as for triggering adaptive and escape strategies.

  6. A method for the retrieval of atomic oxygen density and temperature profiles from ground-based measurements of the O(+)(2D-2P) 7320 A twilight airglow

    Science.gov (United States)

    Fennelly, J. A.; Torr, D. G.; Richards, P. G.; Torr, M. R.; Sharp, W. E.

    1991-01-01

    This paper describes a technique for extracting thermospheric profiles of the atomic-oxygen density and temperature, using ground-based measurements of the O(+)(2D-2P) doublet at 7320 and 7330 A in the twilight airglow. In this method, a local photochemical model is used to calculate the 7320-A intensity; the method also utilizes an iterative inversion procedure based on the Levenberg-Marquardt method described by Press et al. (1986). The results demonstrate that, if the measurements are only limited by errors due to Poisson noise, the altitude profiles of neutral temperature and atomic oxygen concentration can be determined accurately using currently available spectrometers.

  7. PROFILING THE PHONOLOGICAL PROCESSES SHAPING THE FOSSILISED IL OF ADULT SPANISH LEARNERS OF ENGLISH AS FOREIGN LANGUAGE. SOME THEORETICAL IMPLICATIONS.

    Directory of Open Access Journals (Sweden)

    Rafael Monroy Casas

    2001-06-01

    Full Text Available In the ever-growing literature dealing with the acquisition by adults of the phonetics and phonology of a foreign language (FL, research has tried to provide an answer to the complex nature of cross-language transfer. The fact that despite idiosyncratic differences and sociolinguistic variation most adults learners of a foreign language (FL speak with an accent which is a reflection of their native language (NL and that their progress is impaired at a certain stage prompted a host of questions such as whether adults follow identical or different paths of development in their approach to a foreign language, whether those speaking the same native language are able to identify target language categories in the same way, whether perception and production are interdependent, the nature of the learning abilities and the interplay of transfer with universals. These and other problems relating to foreign language speech have been approached from different angles and theoretical frameworks (see Leather & James (1 99 1 for an overview, and more recently Leather (1999. The research reported here, based on the oral production of sixty-five Spanish adult learners of English as a FL, tries to shed some light on one of well-known problems related to the acquisition of a foreign language by non-native speakers: the analysis of different types of phonological processes shaping the fossilised interlanguage (IL of adult FL learners in order to see a whether they are adhered to by those adult learners sharing identical L1; b whether frozen IL reflects transfer from the leamer's L1 or is the result of developmental (Le. universal processes. In this connection we(1987 and SimilarityIDifferential Rate Hypothesis (1999 or Ekman's Markedness Differential Hypothesis (1977 and Structural Conformity Hypothesis in connection with some of the processes under analysis. Optimality Theory will be brought in in dealing with some problems encountered under Cluster Simplification

  8. Formability improvement and blank shape definition for deep drawing of cylindrical cup with complex curve profile from SPCC sheets using FEM

    Institute of Scientific and Technical Information of China (English)

    Duc-Toan Nguyen; Duy-Khoe Dinh; Hong-Minh Thi Nguyen; Tien-Long Banh; Young-Suk Kim

    2014-01-01

    In the current work, to predict and improve the formability of deep drawing process for steel plate cold rolled commercial grade (SPCC) sheets, three parameters including the blanking force, the die and punch corner radius were considered. The experimental plan according to Taguchi’s orthogonal array was coupled with the finite element method (FEM) simulations. Firstly, the data from the test of stress-strain and forming limit curves were used as input into ABAQUS/Explicit finite element code to predict the failure occurrence of deep drawing process. The three parameters were then validated to establish their effects on the press formability. The optimum case found via simulation was finally confirmed through an experiment. In order to obtain the complex curve profile of cup shape after deep drawing, the anisotropic behavior of earring phenomenon was modeled and implemented into FEM. After such phenomenon was correctly predicted, an error metric compared with design curve was then measured.

  9. Profiles of plasma parameters and density of negative hydrogen ions by laser detachment measurements in RF-driven ion sources; Profile der Plasmaparameter und Dichte negativer Wasserstoffionen mittels Laserdetachmentmessungen in HF-angeregten Ionenquellen

    Energy Technology Data Exchange (ETDEWEB)

    Christ-Koch, Sina

    2007-12-20

    This work shows the application of the Laserdetachment method for spatially resolved measurements of negative Hydrogen/Deuterium ion density. It was applied on a high power low pressure RF-driven ion source. The Laser detachment method is based on the measurement of electron currents on a positively biased Langmuir probe before and during/after a laser pulse. The density ratio of negative ions to electrons can be derived from the ratio of currents to the probe. The absolute density of negative ions can be obtained when the electron density is measured with the standard Langmuir probe setup. Measurements with the Langmuir probe additionally yield information about the floating and plasma potential, the electron temperature and the density of positive ions. The Laser detachment setup had to be adapted to the special conditions of the RF-driven source. In particular the existence of RF fields (1 MHz), high source potential (-20 kV), magnetic fields ({proportional_to} 7 mT) and caesium inside the source had to be considered. The density of negative ions could be identified in the range of n(H{sup -})=1.10{sup 17} 1/m{sup 3}, which is in the same order of magnitude as the electron density. Only the application of the Laser detachment method with the Langmuir probe measurements will yield spatially resolved plasma parameters and H- density profiles. The influence of diverse external parameters, such as pressure, RF-power, magnetic fields on the plasma parameters and their profiles were studied and explained. Hence, the measurements lead to a detailed understanding of the processes inside the source. (orig.)

  10. 基于密度峰值的三维模型无监督分类算法%Unsupervised 3D Shape Classification Algorithm Using Density Peaks

    Institute of Scientific and Technical Information of China (English)

    舒振宇; 祁成武; 辛士庆; 胡超; 韩祥兰; 刘利刚

    2016-01-01

    In this paper, we propose an unsupervised classification algorithm by using density peaks for automatic content-based 3D model classification. Firstly, the algorithm extracts multiple kinds of feature vectors for each model in the given shape collection. Secondly, it uses robust principal component analysis to denoise the feature vectors and reduce their dimensions simultaneously. Finally, the algorithm determines the number of categories of the 3D models and realizes an unsupervised classification in an intuitive and visual way by computing the density peaks of the feature vectors’ distribution and a corresponding decision graph. Extensive experimental results show that the number of categories of clustering is much easier to determine and the results are more accurate and ro-bust in our algorithm when compared with the traditional algorithms.%针对基于内容的三维模型自动分类问题,提出一种密度峰值驱动的三维模型无监督分类算法。首先利用多种特征描述符分别对每个三维模型提取相应的特征向量;然后将得到的特征向量运用鲁棒主成分分析去除噪声并降维;最后通过计算特征向量分布的密度峰值,并配合决策图,以直观的方式确定三维模型分类类别数,最终实现三维模型的无监督分类。实验结果表明,与传统算法相比,该算法具有易于确定分类类别数、准确率高、鲁棒性强等优点。

  11. Low bone mineral density and peripheral blood monocyte activation profile in calcium stone formers with idiopathic hypercalciuria.

    Science.gov (United States)

    Ghazali, A; Fuentès, V; Desaint, C; Bataille, P; Westeel, A; Brazier, M; Prin, L; Fournier, A

    1997-01-01

    Calcium stone formers (CaSF) with idiopathic hypercalciuria (IH) have been shown to have decreased bone mineral density (BMD). The mechanism of their bone loss remains obscure. Monokines like interleukin-1 beta (IL-1 beta), IL-6, tumor necrosis factor-alpha (TNF-alpha), and granulocyte macrophage stimulating factor (GM-CSF) are involved in bone remodeling, but only IL-1 excess has been incriminated in the bone loss of CaSF with IH. Therefore, to more precisely delineate the role of monocyte activation in the pathogenesis of bone loss in these patients, we studied the production of IL-1 beta, IL-6, TNF-alpha, and GM-CSF by unstimulated or lipopolysaccharide (LPS)-stimulated cultured peripheral blood monocytes in 15 CaSF with IH, in 10 CaSF with dietary calcium-dependent hypercalciuria (DH), and in 10 healthy controls (C). Cytokines were measured in the culture medium by sensitive enzyme-linked immunosorbent assay and vertebral BMD by single energy computed tomography. The decrease of vertebral BMD in IH compared with DH, was confirmed (Z score: -1.2 +/- 0.2 vs. -0.5 +/- 0.2; P = 0.04; Mann-Whitney). In the supernatant of unstimulated peripheral blood monocytes, IL-1 beta and TNF-alpha levels were higher in IH than in C (respectively, 40 +/- 21 vs. 7 +/- 1 pg/mL, P = 0.008 and 236 +/- 136 vs. 39 +/- 23 pg/mL, P = 0.03); those of GM-CSF were greater in IH than in DH and C (respectively, 52 +/- 27 vs. 6 +/- 2, P = 0.04 and 6 +/- 2 pg/mL, P = 0.01) and those of IL-6 were not significantly different among the groups. After in vitro stimulation by LPS (10 micrograms/mL), the levels of the various monokines were not significantly different. In IH patients, the post-LPS levels of IL-6 were negatively correlated to vertebral BMD (n = 15, Z = -1.97, P = 0.04; Spearman), whereas those of GM-CSF were positively related to vertebral BMD (n = 15, Z = 2.01, P = 0.04). In this study, calcium stone formers with IH have bone mineral decrease and a particular profile of peripheral

  12. A comparative performance study of a photovoltaic concentrator system with discrete mirror and continuos profile for two different absorber shapes

    Energy Technology Data Exchange (ETDEWEB)

    H, Saiful; Rezau, K.M [University of Dhaka, Dhaka (Bangladesh)

    2000-07-01

    Profiles of parabolic concentrators of discrete mirror and continuos surface mirror have been designed for combined electrical thermal photovoltaic systems. In the design the changes of concentration ratio, effect of reflection, angle of incidence over the absorber have been taken into account for maximum energy collection. The performances of the system are studied for solar cells of modified grid finger for illuminations from 1-10 sun. The local concentration ratio (LCR) distribution over the absorbers for both the concentrator, the optical efficiency, thermal efficiency, electrical and thermal power output and overall efficiency have been evaluated for different values of beam radiation concentration ratio and focal distance. [Spanish] Se han disenado perfiles de concentradores parabolicos de espejo discreto y de superficie continua para sistemas fotovoltaicos combinados electricos y termicos. En el diseno los cambios de la proporcion de concentracion, del efecto de la reflexion, del angulo de incidencia sobre el observador se han tenido en cuenta para una maxima recoleccion de energia. Los rendimientos del sistema se han estudiado para celdas solares de parrilla modificada para iluminaciones solares de 1-10. Han sido evaluados para diferentes valores de la proporcion de la concentracion de la radiacion en el rayo y la distancia focal la proporcion de concentracion local (LCR) de la distribucion en los absorbedores, para el concentrador la eficiencia optica, la eficiencia termica, electrica, la produccion de energia termica y electrica y la eficiencia total.

  13. Chromatin states shape insertion profiles of the piggyBac, Tol2 and Sleeping Beauty transposons and murine leukemia virus.

    Science.gov (United States)

    Yoshida, Junko; Akagi, Keiko; Misawa, Ryo; Kokubu, Chikara; Takeda, Junji; Horie, Kyoji

    2017-03-02

    DNA transposons and retroviruses are versatile tools in functional genomics and gene therapy. To facilitate their application, we conducted a genome-wide insertion site profiling of the piggyBac (PB), Tol2 and Sleeping Beauty (SB) transposons and the murine leukemia virus (MLV) in mouse embryonic stem cells (ESCs). PB and MLV preferred highly expressed genes, whereas Tol2 and SB preferred weakly expressed genes. However, correlations with DNase I hypersensitive sites were different for all vectors, indicating that chromatin accessibility is not the sole determinant. Therefore, we analysed various chromatin states. PB and MLV highly correlated with Cohesin, Mediator and ESC-specific transcription factors. Notably, CTCF sites were correlated with PB but not with MLV, suggesting MLV prefers smaller promoter-enhancer loops, whereas PB insertion encompasses larger chromatin loops termed topologically associating domains. Tol2 also correlated with Cohesin and CTCF. However, correlations with ESC-specific transcription factors were weaker, suggesting that Tol2 prefers transcriptionally weak chromatin loops. Consistently, Tol2 insertions were associated with bivalent histone modifications characteristic of silent and inducible loci. SB showed minimum preference to all chromatin states, suggesting the least adverse effect on adjacent genes. These results will be useful for vector selection for various applications.

  14. Chromatin states shape insertion profiles of the piggyBac, Tol2 and Sleeping Beauty transposons and murine leukemia virus

    Science.gov (United States)

    Yoshida, Junko; Akagi, Keiko; Misawa, Ryo; Kokubu, Chikara; Takeda, Junji; Horie, Kyoji

    2017-01-01

    DNA transposons and retroviruses are versatile tools in functional genomics and gene therapy. To facilitate their application, we conducted a genome-wide insertion site profiling of the piggyBac (PB), Tol2 and Sleeping Beauty (SB) transposons and the murine leukemia virus (MLV) in mouse embryonic stem cells (ESCs). PB and MLV preferred highly expressed genes, whereas Tol2 and SB preferred weakly expressed genes. However, correlations with DNase I hypersensitive sites were different for all vectors, indicating that chromatin accessibility is not the sole determinant. Therefore, we analysed various chromatin states. PB and MLV highly correlated with Cohesin, Mediator and ESC-specific transcription factors. Notably, CTCF sites were correlated with PB but not with MLV, suggesting MLV prefers smaller promoter–enhancer loops, whereas PB insertion encompasses larger chromatin loops termed topologically associating domains. Tol2 also correlated with Cohesin and CTCF. However, correlations with ESC-specific transcription factors were weaker, suggesting that Tol2 prefers transcriptionally weak chromatin loops. Consistently, Tol2 insertions were associated with bivalent histone modifications characteristic of silent and inducible loci. SB showed minimum preference to all chromatin states, suggesting the least adverse effect on adjacent genes. These results will be useful for vector selection for various applications. PMID:28252665

  15. Einasto Profiles and the Dark Matter Power Spectrum

    CERN Document Server

    Ludlow, Aaron D

    2016-01-01

    We study the mass accretion histories (MAHs) and density profiles of dark matter halos using N-body simulations of self-similar gravitational clustering from scale-free power spectra, $P(k)\\propto k^n$. We pay particular attention to the density profile curvature, which we characterize using the shape parameter, $\\alpha$, of an Einasto profile. In agreement with previous findings our results suggest that, despite vast differences in their MAHs, the density profiles of virialized halos are remarkably alike. Nonetheless, clear departures from self-similarity are evident: for a given spectral index, $\\alpha$ increases slightly but systematically with "peak height", $\

  16. High energy emission of GRB 130821A: Constraining the density profile of the circum-burst medium as well as the initial Lorentz factor of the outflow

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Yun-Feng; Zhou, Bei; He, Hao-Ning; Fan, Yi-Zhong; Wei, Da-Ming [Key laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Tam, Pak-Hin Thomas, E-mail: phtam@phys.nthu.edu.tw [Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2014-02-01

    GRB 130821A was detected by Fermi-GBM/LAT, Konus-WIND, SPI-ACS/INTEGRAL, RHESSI and Mars Odyssey-HEND. Although the data of GRB 130821A are very limited, we show in this work that the high energy γ-ray emission (i.e., above 100 MeV) alone imposes tight constraint on the density profile of the circum-burst medium as well as the initial Lorentz factor of the outflow. The temporal behavior of the high energy γ-ray emission is consistent with the forward shock synchrotron radiation model, and the circum-burst medium likely has a constant-density profile. The Lorentz factor is about a few hundred, similar to other bright GRBs.

  17. Dicer1-mediated miRNA processing shapes the mRNA profile and function of murine platelets.

    Science.gov (United States)

    Rowley, Jesse W; Chappaz, Stéphane; Corduan, Aurélie; Chong, Mark M W; Campbell, Robert; Khoury, Amanda; Manne, Bhanu Kanth; Wurtzel, Jeremy G T; Michael, James V; Goldfinger, Lawrence E; Mumaw, Michele M; Nieman, Marvin T; Kile, Benjamin T; Provost, Patrick; Weyrich, Andrew S

    2016-04-07

    Human platelets contain microRNAs (miRNAs) and miRNA processing machinery, but their contribution to platelet function remains incompletely understood. Here, we show that murine megakaryocyte (MK)-specific knockdown of Dicer1, the ribonuclease that cleaves miRNA precursors into mature miRNAs, reduces the level of the majority of miRNAs in platelets. This leads to altered platelet messenger RNA (mRNA) expression profiles and mild thrombocytopenia. Fibrinogen receptor subunits Itga2b (αIIb) and Itgb3 (β3) mRNAs were among the differentially expressed transcripts that are increased in platelets lacking Dicer1. Argonaute 2 (Ago2), a member of the miRNA silencing complex, co-immunoprecipitated with αIIband β3mRNAs in wild-type platelets. Furthermore, co-immunoprecipitation experiments suggested reduced αIIb/β3/Ago2 complexes in miRNA-deficient platelets. These results suggested that miRNAs regulate both integrin subunits. Subsequent 3' untranslated region luciferase reporter assays confirmed that the translation of both αIIband β3mRNAs can be regulated by miRNAs miR-326, miR-128, miR-331, and miR-500. Consistent with these molecular changes, the deletion ofDicer1resulted in increased surface expression of integrins αIIband β3, and enhanced platelet binding to fibrinogen in vivo and in vitro. Heightened platelet reactivity, shortened tail-bleeding time, and reduced survival following collagen/epinephrine-induced pulmonary embolism were also observed in Dicer1-deficient animals. CombinedPf4-cre-mediated deletion of Drosha and Dicer1 did not significantly exacerbate phenotypes observed in single Dicer1 knockout mice. In summary, these findings indicate that Dicer1-dependent generation of mature miRNAs in late-stage MKs and platelets modulates the expression of target mRNAs important for the hemostatic and thrombotic function of platelets.

  18. Analysis of the Clinical Profile in Patients with Plasmodium falciparum Malaria and Its Association with Parasite Density.

    Science.gov (United States)

    Mangal, Praveen; Mittal, Shilpa; Kachhawa, Kamal; Agrawal, Divya; Rath, Bhabagrahi; Kumar, Sanjay

    2017-01-01

    Malaria remains a major health hazard in the modern world, particularly in developing countries. In Plasmodium falciparum malaria, there is a direct correlation between asexual erythrocytic stage parasite density and disease severity. Accordingly, the correlations between parasite density and various clinical presentations, severity, and outcome were examined in falciparum malaria in India. The study was conducted in a tertiary health-care center in North India. Of 100 cases of falciparum malaria, 65 patients were male and 35 were female. A total of 54 patients were in the uncomplicated group and 46 patients were in the complicated malaria group. Fever, anemia, icterus, splenomegaly, hepatomegaly, and hepatosplenomegaly were common clinical findings. All clinical findings were significantly more common in the complicated malaria group and patients with a high parasite density than in the uncomplicated group and those with a low parasite density. All patients in the uncomplicated malaria group had a parasite density of 5%, and the difference between groups was statistically significant. The incidence of cerebral malaria was significantly higher in cases with a high parasite density; 58.33% mortality was observed in these cases. Cerebral malaria and hyperbilirubinemia was the most frequently encountered combination of complications. In P. falciparum malaria, parasite density was associated with complications and poor clinical outcomes. These results may inform treatment decisions and suggest that a threshold parasite density of 5% is informative.

  19. Shape of the oceanic nitracline

    Directory of Open Access Journals (Sweden)

    M. M. Omand

    2014-10-01

    Full Text Available In most regions of the ocean, nitrate is depleted near surface by phytoplankton consumption and increases with depth, exhibiting a strong vertical gradient in the pycnocline (here referred to as the nitracline. The vertical supply of nutrients to the surface euphotic zone is influenced by the vertical gradient (slope of the nitracline, and the vertical separation (depth of the nitracline from the sunlit, nutrient-depleted surface layer. Hence it is important to understand the shape (slope and curvature and depth of the oceanic nitracline. By using density coordinates to analyze nitrate profiles from autonomous (APEX-ISUS floats and ship-based platforms (WOA09, HOT, BATS and CalCOFI, we are able to eliminate much of the spatial and temporal variability in the profiles and derive robust relationships between nitrate and density. This allows us to characterize the depth, slope, and curvature of the nitracline in different regions of the world's oceans. The analysis reveals distinguishing patterns in the nitracline between subtropical gyres, upwelling regions and subpolar gyres. We propose a one-dimensional, mechanistic model that relates the shape of the nitracline to the relative depths of the surface mixed layer and euphotic layer. Though heuristic, the model accounts for some of the seasonal patterns and regional differences in the nitrate–density relationships seen in the data.

  20. Shape of the oceanic nitracline

    Science.gov (United States)

    Omand, M. M.; Mahadevan, A.

    2014-10-01

    In most regions of the ocean, nitrate is depleted near surface by phytoplankton consumption and increases with depth, exhibiting a strong vertical gradient in the pycnocline (here referred to as the nitracline). The vertical supply of nutrients to the surface euphotic zone is influenced by the vertical gradient (slope) of the nitracline, and the vertical separation (depth) of the nitracline from the sunlit, nutrient-depleted surface layer. Hence it is important to understand the shape (slope and curvature) and depth of the oceanic nitracline. By using density coordinates to analyze nitrate profiles from autonomous (APEX-ISUS floats) and ship-based platforms (WOA09, HOT, BATS and CalCOFI), we are able to eliminate much of the spatial and temporal variability in the profiles and derive robust relationships between nitrate and density. This allows us to characterize the depth, slope, and curvature of the nitracline in different regions of the world's oceans. The analysis reveals distinguishing patterns in the nitracline between subtropical gyres, upwelling regions and subpolar gyres. We propose a one-dimensional, mechanistic model that relates the