scholarly journals Response of the interplanetary hydrogen population to global changes of solar activity: a quantitative analysis based on SOHO/SWAN and SOHO/LASCO-C2 data comparison.

2021 ◽  
Author(s):  
Dimitra Koutroumpa ◽  
Eric Quémerais ◽  
Lucile Conan ◽  
Philippe Lamy ◽  
Stéphane Ferron ◽  
...  
Keyword(s):  
Interplanetary Space ◽  
Time Lag ◽  
Three Dimensional ◽  
Direct Consequence ◽  
Cycle Phase ◽  
Global Changes ◽  
Hydrogen Atoms ◽  
Hydrogen Ionization ◽  
Coronal Electron ◽  
Ionization Rates

<p>For more than two decades the SOHO/SWAN instrument has been monitoring the full-sky hydrogen backscattered Lyman-α emission, and the derived three-dimensional solar wind proton flux. We present a comparison of the time series of the latitude-integrated hydrogen ionization rates (β) derived from the inversion of the SWAN full-sky maps with the integrated coronal electron density derived from the inversion of SOHO/LASCO-C2 white light images. The analysis shows a variable time lag of the SWAN β of a few Carrington rotations, correlated with the solar cycle phase (larger delay during solar maxima compared to minima). This is a direct consequence of the variation of the size of the hydrogen ionization cavity and the time it takes for hydrogen atoms to propagate in the inner heliosphere. This effect should be taken into account in studies of the interstellar neutral populations in interplanetary space.</p>

Scanning-tunneling spectroscopy on conjugated polymer films

2003 ◽  
Vol 771 ◽  
Author(s):  
M. Kemerink ◽  
S.F. Alvarado ◽  
P.M. Koenraad ◽  
R.A.J. Janssen ◽  
H.W.M. Salemink ◽  
...  
Keyword(s):  
Polymer Films ◽  
Conjugated Polymer ◽  
Three Dimensional ◽  
Field Enhancement ◽  
Direct Consequence ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Band Alignment ◽  
Scanning Tunneling ◽  
Order Of Magnitude

AbstractScanning-tunneling spectroscopy experiments have been performed on conjugated polymer films and have been compared to a three-dimensional numerical model for charge injection and transport. It is found that field enhancement near the tip apex leads to significant changes in the injected current, which can amount to more than an order of magnitude, and can even change the polarity of the dominant charge carrier. As a direct consequence, the single-particle band gap and band alignment of the organic material can be directly obtained from tip height-voltage (z-V) curves, provided that the tip has a sufficiently sharp apex.

Ab Initio Determination of a New Complex Structure (55 Non-Hydrogen Atoms) from Synchrotron Powder Data: An Uncommon Nickel Succinate, Ni7(C4H4O4)4(OH)6(H2O)3•7H2O

2004 ◽  
Vol 443-444 ◽  
pp. 333-336
Author(s):  
N. Guillou ◽  
C. Livage ◽  
W. van Beek ◽  
G. Férey
Keyword(s):  
Ab Initio ◽  
Complex Structure ◽  
Three Dimensional ◽  
Free Water ◽  
Hydrogen Atoms ◽  
Monoclinic System ◽  
Synchrotron Powder Diffraction ◽  
Chloride Hexahydrate ◽  
Autogenous Pressure

Ni7(C4H4O4)4(OH)6(H2O)3. 7H2O, a new layered nickel(II) succinate, was prepared hydrothermally (180°C, 48 h, autogenous pressure) from a 1:1.5:4.1:120 mixture of nickel (II) chloride hexahydrate, succinic acid, potassium hydroxide and water. It crystallizes in the monoclinic system (space group P21/c, Z = 4) with the following parameters a = 7.8597(1) Å, b = 18.8154(3)Å, c = 23.4377(4) Å,ϐ = 92.0288(9)°, and V = 3463.9(2) Å3. Its structure, which contains 55 non-hydrogen atoms, was solved ab initio from synchrotron powder diffraction data. It can be described from hybrid organic-inorganic layers, constructed from nickel oxide corrugated chains. These chains are built up from NiO6hexameric units connected via a seventh octahedron. Half of the succinates decorate the chains, and the others connect them to form the layers. The three dimensional arrangement is ensured by hydrogen bonds directly between two adjacent layers and via free water molecules.

scholarly journals 5-Methyl-1,3-phenylene bis[5-(dimethylamino)naphthalene-1-sulfonate]: crystal structure and DFT calculations

2019 ◽  
Vol 75 (7) ◽  
pp. 1079-1083
Author(s):  
Tanwawan Duangthongyou ◽  
Ramida Rattanakam ◽  
Kittipong Chainok ◽  
Songwut Suramitr ◽  
Thawatchai Tuntulani ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Energy Gap ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Hydrogen Atoms ◽  
Lumo Energy ◽  
Compound C ◽  
Dansyl Group ◽  
Weak Hydrogen Bonds ◽  
Homo Lumo

The title compound, C31H30N2S2O6, possesses crystallographically imposed twofold symmetry with the two C atoms of the central benzene ring and the C atom of its methyl substituent lying on the twofold rotation axis. The two dansyl groups are twisted away from the plane of methylphenyl bridging unit in opposite directions. The three-dimensional arrangement in the crystal is mainly stabilized by weak hydrogen bonds between the sulfonyl oxygen atoms and the hydrogen atoms from the N-methyl groups. Stacking of the dansyl group is not observed. From the DFT calculations, the HOMO–LUMO energy gap was found to be 2.99 eV and indicates n→π* and π→π* transitions within the molecule.

Reduced-order analysis of an oil-fuel furnace vibration and comparison with the finite element method

2018 ◽  
Vol 25 (2) ◽  
pp. 298-309
Author(s):  
Hao Zhou ◽  
Sheng Meng ◽  
Chunhong Mo ◽  
Lujun Wang ◽  
Xiukui Hu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Gas Turbines ◽  
Time Lag ◽  
Three Dimensional ◽  
Longitudinal Mode ◽  
Reduced Order ◽  
Separation Plate ◽  
Oil Fuel ◽  
Element Method

Thermoacoustic oscillation occurs in modern industrial furnaces, gas turbines, and liquid rockets. However, the thermoacoustic prediction tools for furnaces vibration are less developed. This paper presents a one-dimensional (1D) linear acoustic approach to analyze the three-dimensional acoustic modes of a 660 MWe oil-fuel furnace. The interaction between the flame and acoustic field is described with the flame transfer function. The global time delay is evaluated through a Reynolds averaged simulation. The results of the 1D acoustic approach are compared with real furnace test data. The unstable modes are close to the natural modes of the furnace, and the 30 Hz in the longitudinal mode is the strongest vibration frequency. The effects of inlet length reduction and separation plate removal are also examined. When the separation plates are removed, the time lag of flame in response to inlet flow decreases from 52.5 milliseconds (ms) to 43.8 ms. The results of the 1D approach and finite element method (FEM) show a same safe operation window. The reduced-order procedure and FEM adopted in this study give us a solution to mitigate the vibration in the furnace.

Fuzzy Noise-Induced Codimension-Two Bifurcations Captured by Fuzzy Generalized Cell Mapping with Adaptive Interpolation

2019 ◽  
Vol 29 (11) ◽  
pp. 1950151
Author(s):  
Xiao-Ming Liu ◽  
Jun Jiang ◽  
Ling Hong ◽  
Zigang Li ◽  
Dafeng Tang
Keyword(s):  
Nonlinear Dynamical Systems ◽  
Three Dimensional ◽  
Maximum Efficiency ◽  
Global Changes ◽  
Cell Mapping ◽  
Generalized Cell Mapping ◽  
Codimension Two ◽  
Adaptive Interpolation ◽  
Membership Matrix ◽  
Fuzzy Noise

In this paper, the Fuzzy Generalized Cell Mapping (FGCM) method is developed with the help of the Adaptive Interpolation (AI) in the space of fuzzy parameters. The adaptive interpolation on the set-valued fuzzy parameter is introduced in computing the one-step transition membership matrix to enhance the efficiency of the FGCM. For each of initial points in the state space, a coarse database is constructed at first, and then interpolation nodes are inserted into the database iteratively each time errors are examined with the explicit formula of interpolation error until the maximal errors are just under the error bound. With such an adaptively expanded database on hand, interpolating calculations assure the required accuracy with maximum efficiency gains. The new method is termed as Fuzzy Generalized Cell Mapping with Adaptive Interpolation (FGCM with AI), and is used to investigate codimension-two bifurcations in two-dimensional and three-dimensional nonlinear dynamical systems with fuzzy noise. It is found that global changes in fuzzy dynamics are dominated by the underlying deterministic counterparts, and the fuzzy attractor expands along the unstable manifold leading to a collision with a saddle when a bifurcation occurs. The examples show that the FGCM with AI has a thirtyfold to fiftyfold efficiency over the traditional FGCM to achieve the same analyzing accuracy.

Structure and conformation of the hydrochloride of pseudoisocytidine, an antileukemic C-nucleoside

1980 ◽  
Vol 58 (16) ◽  
pp. 1633-1638 ◽  
Author(s):  
George I. Birnabaum ◽  
Kyoichi A. Watanabe ◽  
Jack J. Fox
Keyword(s):  
Heavy Atom ◽  
Three Dimensional ◽  
Direct Methods ◽  
Dimensional Structure ◽  
Side Chain ◽  
Hydrogen Atoms ◽  
Triclinic Space Group ◽  
X Ray Crystallography ◽  
Cell Dimensions ◽  
Sugar Ring

The three-dimensional structure of pseudoisocytidine hydrochloride was determined by X-ray crystallography. The crystals belong to the triclinic space group P1 and the cell dimensions are a = 6.623(2), b = 8.053(2), c = 6.201(2) Å, α = 108.35(2), β = 101.36(2), γ = 93.54(2) °. Intensity data were measured with a diffractometer and the structure was solved by a combination of heavy-atom and direct methods. Least-squares refinement, which included hydrogen atoms, converged at R = 0.040. The conformation about the glycosyl bond is anti (χCC = 21.6°), the pucker of the furanose ring is C(1′)exo, and the conformation of the —CH2OH side chain is gauche–trans (t). An examination of bond lengths indicates that of the three main resonance forms of the isocytosine cation the fully conjugated one contributes more to the structure than the cross-conjugated one. Bond angles in the sugar ring reflect its rare conformation.

scholarly journals 3-D reconstructions of the early-November 2004 CDAW geomagnetic storms: analysis of Ooty IPS speed and density data

2009 ◽  
Vol 27 (12) ◽  
pp. 4479-4489 ◽  
Author(s):  
M. M. Bisi ◽  
B. V. Jackson ◽  
J. M. Clover ◽  
P. K. Manoharan ◽  
M. Tokumaru ◽  
...  
Keyword(s):  
Solar Wind ◽  
Geomagnetic Storms ◽  
Interplanetary Space ◽  
Tomographic Reconstruction ◽  
Three Dimensional ◽  
Reconstruction Technique ◽  
The Sun ◽  
Wide Range ◽  
Digital Resolution ◽  
Wind Spacecraft

Abstract. Interplanetary scintillation (IPS) remote-sensing observations provide a view of the solar wind covering a wide range of heliographic latitudes and heliocentric distances from the Sun between ~0.1 AU and 3.0 AU. Such observations are used to study the development of solar coronal transients and the solar wind while propagating out through interplanetary space. They can also be used to measure the inner-heliospheric response to the passage of coronal mass ejections (CMEs) and co-rotating heliospheric structures. IPS observations can, in general, provide a speed estimate of the heliospheric material crossing the observing line of site; some radio antennas/arrays can also provide a radio scintillation level. We use a three-dimensional (3-D) reconstruction technique which obtains perspective views from outward-flowing solar wind and co-rotating structure as observed from Earth by iteratively fitting a kinematic solar wind model to these data. Using this 3-D modelling technique, we are able to reconstruct the velocity and density of CMEs as they travel through interplanetary space. For the time-dependent model used here with IPS data taken from the Ootacamund (Ooty) Radio Telescope (ORT) in India, the digital resolution of the tomography is 10° by 10° in both latitude and longitude with a half-day time cadence. Typically however, the resolutions range from 10° to 20° in latitude and longitude, with a half- to one-day time cadence for IPS data dependant upon how much data are used as input to the tomography. We compare reconstructed structures during early-November 2004 with in-situ measurements from the Wind spacecraft orbiting the Sun-Earth L1-Point to validate the 3-D tomographic reconstruction results and comment on how these improve upon prior reconstructions.

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