bluuebunny/crossref_metadata_2025_split huggingface dataset:
Triple correlations in local helioseismology
Authors: Pijpers F. P. 
Published: March 2007

AbstractA central step in time‐distance local helioseismology techniques is to obtain travel times of packets of wave signals between points or sets of points on the visible surface. Standard ways of determining group or phase travel times involve cross‐correlating the signal between locations at the solar photosphere and determining the shift of the envelope of this cross correlation function, or a zero crossing, using a standard wavelet or a reference wave packet. Here a novel method is described which makes use of triple correlations, i.e. cross‐correlating signal between three locations. By using an average triple correlation as reference, differential travel times can be extracted in a straightforward manner. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Linear sensitivity of helioseismic travel times to local flows
Authors: Birch A. C. , Gizon L. 
Published: March 2007

AbstractTime‐distance helioseismology is a technique for measuring the time for waves to travel from one point on the solar surface to another. These wave travel times are affected by advection by subsurface flows. Inferences of plasma flows based on observed travel times depend critically on the ability to accurately model the effects of subsurface flows on time‐distance measurements. We present a Born‐approximation based computation of the sensitivity of time‐distance travel times to weak, steady, inhomogeneous subsurface flows. Three sensitivity functions are obtained, one for each component of the 3D vector flow. We show that the depth sensitivity of travel times to horizontally uniform flows is given approximately by the kinetic energy density of the oscillation modes which contribute to the travel times. For flows with strong depth dependence, the Born approximation can give substantially different results than the ray approximation. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Meridional circulation and differential rotation in the solar convection zone
Authors: Shibahashi H. 
Published: March 2007

AbstractWith the development of local helioseismology, such as the time‐distance technique, investigation of meridional flow and differential rotation in the solar convection zone has become possible. I summarize recent observational results, and review theoretical considerations of meridional circulation in relation to differential rotation, which is now well unveiled in the solar convection zone by helioseismology. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surface magnetic field effects in local helioseismology
Authors: Schunker H. , Braun D. C. , Cally P. S. 
Published: March 2007

AbstractUsing helioseismic holography strong evidence is presented that the phase (or equivalent travel‐time) of helioseismic signatures in Dopplergrams within sunspots depend upon the line‐of‐sight angle in the plane containing the magnetic field and vertical directions. This is shown for the velocity signal in the penumbrae of two sunspots at 3, 4 and 5 mHz. Phasesensitive holography demonstrates that they are significantly affected in a strong, moderately inclined magnetic field. This research indicates that the effects of the surface magnetic field are potentially very significant for local helioseismic analysis of active regions. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetoseismic signatures and flow diagnostics beneath magnetic regions
Authors: Lindsey C. , Schunker H. , Cally P. S. 
Published: March 2007

AbstractOne of the major, important developments in local helioseismology was the discovery by Duvall et al. (1996) that the travel times of seismic waves into sunspots from the surrounding quiet Sun significantly exceed the same in the reverse direction, a behavior they suggested was the result of rapid downflows directly beneath the sunspot photosphere. This led to the need for rapid near‐surface horizontal inflows to replace the mass evacuated from the sunspot subphotosphere by such downflows. The lack of independent evidence for such inflows led to the suggestion that the travel‐time asymmetry could be explained by a relative phase delay in the response of the sunspot photosphere to incoming waves with respect to that of the quiet Sun. In the succeeding ten years major progress has been made in our understanding of how magnetic photospheres respond to incoming waves, at the instigation of theoretical work by Spruit, Cally and Bogdan. This has led to the recognition of inclined penumbral magnetic fields as a major avenue for control work on the subject of the traveltime asymmetry and its relation to the absorption of p‐modes by magnetic regions. A major recent development has been the discovery by Schunker et al. (2005) that the phase of this response in Doppler observations of penumbral photospheres depends strongly on the vantage of the Doppler measurements projected into the vertical plane of the magnetic field. This discovery heavily reinforces the proposition that the travel‐time asymmetry is largely the signature of the same irreversible damping processes that are responsible for the strong absorption of p‐modes in magnetic regions. We will elaborate on the implications of the foregoing developments respecting the diagnostics of subphotospheric flows based on seismic observations in which magnetic regions cannot be avoided. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Leakage of photospheric motions into the magnetic solar atmosphere: new prospects of magneto‐seismology
Authors: Erdélyi R. , Pintér B. , Malins C. 
Published: March 2007

AbstractThe leakage and coupling of solar global oscillations to the overlaying magnetized solar atmosphere is investigated in this paper. Solar global acoustic oscillations may couple through resonant absorption to atmospheric local magnetic eigenoscillations (i) resulting in small shifts of the order of μHz in the real part of their frequencies as compared to their non‐magnetic counterparts, and (ii) causing dissipation of wave energy and a consequent line broadening of the modes. Alternatively, global modes may also penetrate deeply into the magnetized solar atmosphere through leakage along magnetic field lines causing small‐scale structuring in the transition region and low corona. By analyzing the dynamic fragmentation generated by direct wave propagations, one may deduce diagnostic information about the geometric and physical properties of the local magnetic environment in the atmosphere. A few numerical examples are presented here to demonstrate the leakage of global oscillations and its influence and omnipotence on the dynamics of the lower solar atmosphere. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Scattering of p‐modes by a thin fluxtube in a stratified atmosphere
Authors: Gordovskyy M. , Jain R. 
Published: March 2007

AbstractIn the present paper we investigate scattering of low and intermediate degree p‐modes on a thin magnetic fluxtube embedded into a stratified polytropic atmosphere. Using the Born approximation approach we find the solution of linearized MHD equations and calculate resulting phase shifts of scattered waves for different sets of fluxtube parameters. Possible application of the results to the analysis of observational data is discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
SLiM: a code for the simulation of wave propagation through an inhomogeneous, magnetised solar atmosphere
Authors: Cameron R. , Gizon L. , Daiffallah K. 
Published: March 2007

AbstractIn this paper we describe the semi‐spectral linear MHD (SLiM) code which we have written to follow the interaction of linear waves through an inhomogeneous three‐dimensional solar atmosphere. The background model allows almost arbitrary perturbations of density, temperature, sound speed as well as magnetic and velocity fields. We give details of several of the tests we have used to check the code. The code will be useful in understanding the helioseismic signatures of various solar features, including sunspots. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The solar acoustic simulator: applications and results
Authors: Hanasoge S. M. , Duvall T. L. 
Published: March 2007

AbstractIt is important to understand the limits and accuracy of helioseismic techniques in their ability to probe the solar interior. The availability of a method that is able to compute the solar acoustic wave field in the presence of thermal or flow perturbations affords us a means to place bounds on detectability and accuracy of inferences of interior perturbations. We describe the technique used to simulate wave propagation within a spherical shell that extends from a desired depth (not including the center) into the solar atmosphere and which possesses a solar like stratification. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First local helioseismic experiments with CO5BOLD
Authors: Steiner O. , Vigeesh G. , Krieger L. , Wedemeyer‐Böhm S. , Schaffenberger W. , Freytag B. 
Published: March 2007

AbstractWith numerical experiments we explore the feasibility of using high frequency waves for probing the magnetic fields in the photosphere and the chromosphere of the Sun.We track a plane‐parallel, monochromatic wave that propagates through a non‐stationary, realistic atmosphere, from the convection‐zone through the photosphere into the magnetically dominated chromosphere, where it gets refracted and reflected. We compare the wave travel time between two fixed geometrical height levels in the atmosphere (representing the formation height of two spectral lines) with the topography of the surface of equal magnetic and thermal energy density (the magnetic canopy or β = 1 contour) and find good correspondence between the two. We conclude that high frequency waves indeed bear information on the topography of the ‘magnetic canopy’. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Towards using modern data assimilation and weather forecasting methods in solar physics
Authors: Brun A. S. 
Published: March 2007

AbstractWe discuss how data assimilation and forecasting methods developed in Earth's weather prediction models could be used to improve our capability to anticipate solar dynamical phenomena and assimilate the huge amount of data that new solar satellites, such as SDO or Hinode, will provide in the coming years. We illustrate with some simple examples such as the solar magnetic activity cycle, the eruption of CMEs, the real potential of such methods for solar physics. We believe that we now need to jointly develop solar forecasting models, whose purpose are to assimilate observational data in order to improve our predictability power, with “first principle” solar models, whose purpose is to understand the underpinning physical processes behind the solar dynamics. These two complementary approaches should lead to the development of a solar equivalent of Earth's general circulation model. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Solar Orbiter mission and its prospects for helioseismology
Authors: Woch J. , Gizon L. 
Published: March 2007

AbstractSolar Orbiter is intended to become ESA's next solar mission in heritage of the successful SOHO project. The scientific objectives of the mission, its design, and its scientific payload are reviewed. Specific emphasis is given to the prospects of Solar Orbiter with respect to helioseismology. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Helioseismology program for Solar Dynamics Observatory
Authors: Kosovichev A. G. , HMI Science Team  
Published: March 2007

AbstractAn overview of the science investigation program for the Helioseismic and Magnetic Imager (HMI) of the Solar Dynamics Observatory (SDO) space mission scheduled for launch in 2008 is presented. The HMI investigation encompasses three primary objectives of the Living With a Star Program:.rst, to determine how and why the Sun varies; second, to improve our understanding of how the Sun drives global change and space weather; and third, to determine to what extent predictions of space weather and global change can be made and to prototype predictive techniques. Helioseismology provides unique tools to study the basic mechanisms of the Sun's magnetic activity and variability. It plays a crucial role in all HMI investigations, which include convection‐zone dynamics and the solar dynamo; origin and evolution of sunspots, active regions and complexes of activity; sources and drivers of solar activity and disturbances; links between the internal processes and dynamics of the corona and heliosphere; and precursors of solar disturbances for space‐weather forecasts. We describe new unique opportunities for helioseismology studies with HMI data, in combination with data from the other SDO instruments, Atmospheric Imaging Assembly (AIA) and Extreme‐ultraviolet Variability Experiment (EVE), and also from various space and ground‐based observatories. The complete HMI science investigation and data analysis plan is available at http://hmi.stanford.edu. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Some remarks on the state of helioseismology
Authors: Leibacher J. W. 
Published: March 2007

AbstractI offer some very brief questions and remarks on the state of helioseismology, specifically: i) What is the relationship between the study of a phenomenon in its own right, its use as a tool, and the broader phenomena to which the tool can be applied? ii) Does the jargon of our local helioseismic techniques serve us well? iii) What is the role of the interactions with the areas of science with which helioseismology interacts most closely?
Precise bacterial polyprenol length control fails in Saccharomyces cerevisiae
Authors: Poznański Jarosław , Szkopinska Anna 
Published: March 2007

AbstractA comparison of amino acid sequences of yeast Rer2p and Srt1p Z‐prenyltransferases shows that the spatial organization of their substrate tunnels agrees with that determined by X‐ray for the E. coli undecaprenyl diphosphate synthase (UPPs). The observed trend in the maxima of product length distribution shifted from C55 in UPPs to C80 in Rer2p and to C110 in Srt1p. This suggests a significant increase in the size of the enzyme hydrophobic tunnel from ∼1000 Å3 of E. coli UPPs to ∼1300 Å3 required to accommodate C80 in Rer2p and to 1700 Å3 for C110 in Srt1p. Moreover, Srt1p products reaching C290 indicate the failure of a strict bacterial‐like chain length control. On the basis of E. coli UPPs crystallographic structure the yeast Rer2p model was constructed. In the model three amino acid residues inserted into the sequence corresponding to the “floor” region of the tunnel extends the bottom loop what results in the required increase of the tunnel volume. Moreover, thermal fluctuations of this loop occasionally create a hole in the tunnel floor, making escape of polyprenol ω end out of the tunnel possible what switches off the control mechanism of product length thereby allowing a practically unlimited elongation process leading to an exponential distribution of longer chain polyprenols. © 2007 Wiley Periodicals, Inc. Biopolymers 86: 155–164, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
When oil and wind turbine companies make green sense together
Authors: Backer Lise 
Published: March 2007

AbstractIn this article I contribute to descriptive green business research on how processes of eco‐effective greening business unfold in practical reality. I look into the case of the increasing interaction between the multinational oil company Shell and the world's largest wind turbine company Vestas. I draw on descriptive organizational sense‐making theory and analyse to this end the shared green sense‐making of Shell and Vestas on off‐shore wind energy business. The article concludes that greening companies such as Shell – that are not born green – might be considerably advanced if these companies strengthen their relationships with companies such as Vestas – that are born green. This is so since companies that are born green have strong green ecocentric business beliefs that can function as important engines in shared green sense‐making with companies that are not born green and have more hesitant green beliefs. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
The Non‐Centrosymmetric Borate Oxides, MBi2B2O7 (M: Ca, Sr).
Authors: Barbier J. , Cranswick L. M. D. 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Crystal Structure of Lanthanum Bismuth Silicate Bi2‐xLaxSiO5 (x≈0.1).
Authors: Georges Samuel , Goutenoire Francois , Lacorre Philippe 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Discrete Pr6Pd Octahedra in Pr6Pd13Cd4 — An Intermetallic Analogon to the Subnitride Na16Ba6N.
Authors: Dogan Ahmet , Hoffmann Rolf‐Dieter , Poettgen Rainer 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
High Temperature Thermoelectric Properties of Mo3Sb7‐xTex for x = 1.6 and 1.5.
Authors: Gascoin Franck , Rasmussen Julia , Snyder G. Jeffrey 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Comparison of the Magnetic Properties of Gd7T3 (T = Pd and Rh) Single Crystals.
Authors: Talik E. , Klimczak M. , Troc R. , Kusz J. , Hofmeister W. , Damm A. 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Magnetic and Transport Properties of Zn0.4Fe2.6O4 Thin Films with Highly Preferential Orientation
Authors: Lu Z. L. , Zou W. Q. , Liu X. C. , Lin Y. B. , Lu Z. H. , Wang J. F. , Xu J. P. , Lv L. Y. , Zhang F. M. , Du Y. W. 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Vertical Section AgIn5Se8—CdIn2Se4 and Crystal Structure of the AgIn5Se8 Compound (4T‐Polytype).
Authors: Ivashchenko I. A. , Gulay L. D. , Zmiy O. F. , Olekseyuk I. D. 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Hydrothermal Synthesis and Photocatalytic Property of KNb3O8 with Nanometer Leaf‐Like Network.
Authors: Zhang Gaoke , He Fangsheng , Zou Xi , Gong Jie , Tu Haibin , Zhang Hao , Zhang Qiang , Liu Ying 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and Structure of the Basic Alkaline Earth Nitrates Sr2(OH)3NO3 and Ba2(OH)3NO3.
Authors: Dill Simone , Gibson Katharina , Glaser Jochen , Tragl Sonja , Meyer H.‐Juergen 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Cadmium Nitride Cd3N2 by Thermolysis of Cadmium Azide Cd(N3)2 and Crystal Structure Determination from X‐Ray Powder Diffraction Data.
Authors: Karau Friedrich , Schnick Wolfgang 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Microwave‐Assisted Oxidation of Some Aromatics by Hydrogen Peroxide at Supported Tungsten Catalyst.
Authors: Lukasiewicz Marcin , Bogdal Dariusz , Pielichowski Jan 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Water‐Soluble Diruthenium Complexes Bearing Acetate and Carbonate Bridges: Highly Efficient Catalysts for Aerobic Oxidation of Alcohols in Water.
Authors: Komiya Naruyoshi , Nakae Takahiro , Sato Hideomi , Naota Takeshi 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Oxygen Replacement by Fluorine in Carbonyl Derivatives of Perfluoroaromatic Compounds and Isomerization of Perfluoroindan‐1,3‐dione to Perfluoro‐3‐methylenephthalide under the Action of HF/SbF5.
Authors: Zonov Yaroslav V. , Karpov Victor M. , Platonov Vyacheslav E. , Rybalova Tatjana V. , Gatilov Yuri V. 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Pentafluorophenylammonium Triflate (PFPAT): An Efficient, Practical, and Cost‐Effective Catalyst for Esterification, Thioesterification, Transesterification, and Macrolactone Formation.
Authors: Funatomi Takashi , Wakasugi Kazunori , Misaki Tomonori , Tanabe Yoo 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Amides Using the Ritter Reaction with Bismuth Triflate Catalysis.
Authors: Callens Emmanuel , Burton Andrew J. , Barrett Anthony G. M. 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
An Efficient Synthesis of 5′‐(4‐Cyanophenyl)‐2,2′‐bifuran‐5‐carbonitrile and Analogues.
Authors: Ismail Mohamed A. 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Reactions of 1,1,4,4‐Tetramethylsemicarbazide with Prop‐2‐ynyl Bromide, Allyl Bromide, and 1,3‐Dibromoprop‐1‐yne.
Authors: Elokhina V. N. , Nakhmanovich A. S. , Abramova E. V. , Larina L. I. 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Sequential C—N, C—C Bond‐Forming Reaction: Direct Synthesis of α‐Amino Acids from Terminal Alkynes.
Authors: Lee Alison V. , Schafer Laurel L. 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis, Characterization, and Antipeptic Activity of a Novel Surfactant Having an Azulene Moiety.
Authors: Fujio Katsuhiko , Kobayashi Hideharu , Ozeki Sumio , Fujimori Kunihide 
Published: March 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.