bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effectiveness of isotopically labelled and non‐isotopically labelled internal standards in the gas chromatography/mass spectrometry analysis of sulfur compounds in wines: use of a statistically based matrix comprehensive approach
Authors: Lavagnini Irma , Fedrizzi Bruno , Versini Giuseppe , Magno Franco 
Published: March 2009

AbstractThe effectiveness of isotopically and non‐isotopically labelled internal standards in reducing matrix‐induced effects is evaluated. The question is addressed in the quantitative analysis by gas chromatography/mass spectrometry (GC/MS) of dimethyl sulphide, chosen as a typical example of volatile sulphur compounds, in wine matrices. When matrix/run effects are not cancelled out the use of a variance component model (VCM) to handle the linear calibrations obtained by regression technique is successful. The method implies the estimation of an overall calibration straight line, which properly takes into account the uncertainty due to different matrices, the calibration run and the measurement error, making the use of an isotopically labelled internal standard not necessary. The obtained results show that the benefits of lowering times and costs for routine analyses compensate for the small increase in uncertainty in the concentration values obtained in the regression analysis and the slight increase in the detection limit. Copyright © 2009 John Wiley & Sons, Ltd.
A Musculoskeletal Profile of Elite Female Soccer Players
Authors: Chiaia Theresa A. , Maschi Robert A. , Stuhr Robyn M. , Rogers Jennifer R. , Sheridan Monique A. , Callahan Lisa R. , Hannafin Jo A. 
Published: March 2009

The purpose of this study is to identify lower-extremity (LE) musculoskeletal characteristics of elite female soccer players and to determine whether differences between dominant and nondominant extremities exist with respect to strength, flexibility, and range of motion. Physical data were collected from 26 female professional soccer players. Core control, hip and knee passive range of motion (PROM), LE flexibility, hip abductor strength, and dynamic functional alignment were assessed for each LE. Of 26 subjects, 21 scored 2/5 or less on core control. Mean hip internal rotation and external rotation were 33° (±8°) and 25° (±6.7°), respectively. All subjects had shortened two-joint hip flexors with an average knee flexion angle of 50° (±11°) and increased femoral anteversion. Forty one of 48 dominant limbs and 42 of 48 nondominant limbs demonstrated deviations from neutral alignment during step down or single-leg squat. Of 25 subjects, 15 demonstrated a stiff-knee landing and/or takeoff. All subjects demonstrated limitations in hip external rotation PROM and hip flexor length. There was no difference between dominant and nondominant LEs in all variables including hip abductor strength. Additional research is needed to determine if there is a correlation between the musculoskeletal characteristics, LE biomechanics, and potential risk for injury. Level of evidence: IV
A Process for the Aqueous Enzymatic Extraction of Corn Oil from Dry Milled Corn Germ and Enzymatic Wet Milled Corn Germ (E‐Germ)
Authors: Moreau Robert A. , Dickey Leland C. , Johnston David B. , Hicks Kevin B. 
Published: March 2009

AbstractA bench‐scale aqueous enzymatic method was developed to extract corn oil from corn germ from either a commercial corn dry mill or corn germ from a newly‐developed experimental enzymatic wet milling process (E‐Germ). With both types of germs, no oil was extracted when acidic cellulase was the only enzyme used. Pre‐treating dry milled corn germ by heating it in boiling water or microwave pretreatment, followed by enzymatic extraction with the acidic cellulase resulted in oil yields of about 43% and 57%, respectively. A two‐step process, combining both acidic cellulase and alkaline protease treatments, with no heat pretreatment, achieved oil yields of 50–65% from dry milled corn germ and 80–90% from E‐Germ.
Connecting the dots: Guillaume Du Fay and Savoy during the schism
Authors: Planchart Alejandro Enrique 
Published: March 2009

ABSTRACTFollowing the Council of Basel in 1439, which initiated the papal schism between Eugenius IV and Felix V (Duke Amadeus VIII of Savoy), Guillaume Du Fay appears to have resumed his northern connections, leaving the court of Savoy and returning to the patronage of the Duke of Burgundy. This article sheds new light on the timing of the composer's move, and on his continued contact with the court of Savoy during the schism of the 1440s. Examination of liturgical sources from the cathedral of Cambrai and elsewhere brings to light a liturgical and musical anomaly in Du Fay's polyphonic settings of Mass Propers for St Maurice, composed during this period, suggesting that this cycle may have been commissioned from Savoy, although Du Fay seems to have had access only to Cambrai chant sources for its cantus firmi.
X-Ray Microanalysis Combined with Monte Carlo Simulation for the Analysis of Layered Thin Films: The Case of Carbon Contamination
Authors: Armigliato Aldo , Rosa Rodolfo 
Published: March 2009

AbstractA previously developed Monte Carlo code has been extended to the X-ray microanalysis in a (scanning) transmission electron microscope of plan sections, consisting of bilayers and triple layers. To test the validity of this method for quantification purposes, a commercially available NiOx (x ∼ 1) thin film, deposited on a carbon layer, has been chosen. The composition and thickness of the NiO film and the thickness of the C support layer are obtained by fitting to the three X-ray intensity ratios I(NiK)/I(OK), I(NiK)/I(CK), and I(OK)/I(CK). Moreover, it has been investigated to what extent the resulting film composition is affected by the presence of a contaminating carbon film at the sample surface. To this end, the sample has been analyzed both in the (recommended) “grid downward” geometry and in the upside/down (“grid upward”) situation. It is found that a carbon contaminating film of few tens of nanometers must be assumed in both cases, in addition to the C support film. Consequently, assuming the proper C/NiOx/C stack in the simulations, the Monte Carlo method yields the correct oxygen concentration and thickness of the NiOx film.
Secondary Electron Emission Contrast of Quantum Wells in GaAs p-i-n Junctions
Authors: Grunbaum Enrique , Barkay Zahava , Shapira Yoram , Barnham Keith W.J. , Bushnell David B. , Ekins-Daukes Nicholas J. , Mazzer Massimo , Wilshaw Peter 
Published: March 2009

AbstractThe secondary electron (SE) signal over a cleaved surface of GaAs p-i-n solar cells containing stacks of quantum wells (QWs) is analyzed by high-resolution scanning electron microscopy. The InGaAs QWs appear darker than the GaAsP barriers, which is attributed to the differences in electron affinity. This method is shown to be a powerful tool for profiling the conduction band minimum across junctions and interfaces with nanometer resolution. The intrinsic region is shown to be pinned to the Fermi level. Additional SE contrast mechanisms are discussed in relation to the dopant regions themselves as well as the AlGaAs window at the p-region. A novel method of in situ observation of the SE profile changes resulting from reverse biasing these structures shows that the built-in potential may be deduced. The obtained value of 0.7 eV is lower than the conventional bulk value due to surface effects.
Universal processes in heliophysics
Authors: Davila Joseph M. , Gopalswamy Nat , Thompson Barbara J. 
Published: March 2009

AbstractThe structure of the Universe is determined primarily by the interplay of gravity which is dominant in condensed objects, and the magnetic force which is dominant in the rarefied medium between condensed objects. Each of these forces orders the matter into a set of characteristic structures each with the ability to store and release energy in response to changes in the external environment. For the most part, the storage and release of energy proceeds through a number of Universal Processes. The coordinated study of these processes in different settings provides a deeper understanding of the underlying physics governing Universal Processes in astrophysics.
Sun and planets from a climate point of view
Authors: Beer J. , Abreu J. A. , Steinhilber F. 
Published: March 2009

AbstractThe Sun plays a dominant role as the gravity centre and the energy source of a planetary system. A simple estimate shows that it is mainly the distance from the Sun that determines the climate of a planet. The solar electromagnetic radiation received by a planet is very unevenly distributed on the dayside of the planet. The climate tries to equilibrate the system by transporting energy through the atmosphere and the oceans provided they exist. These quasi steady state conditions are continuously disturbed by a variety of processes and effects. Potential causes of disturbance on the Sun are the energy generation in the core, the energy transport trough the convection zone, and the energy emission from the photosphere. Well understood are the effects of the orbital parameters responsible for the total amount of solar power received by a planet and its relative distribution on the planet's surface. On a planet, many factors determine how much of the arriving energy enters the climate system and how it is distributed and ultimately reemitted back into space. On Earth, there is growing evidence that in the past solar variability played a significant role in climate change.
Space weather: science and effects
Authors: Crosby Norma B. 
Published: March 2009

AbstractFrom the point-of-view of somebody standing outside on a cold winter night looking up at a clear cloudless sky, the space environment seems to be of a peaceful and stable nature. Instead, the opposite is found to be true. In fact the space environment is very dynamic on all spatial and temporal scales, and in some circumstances may have unexpected and hazardous effects on technology and humans both in space and on Earth. In fact the space environment seems to have a weather all of its own – its own “space weather”. Our Sun is definitely the driver of our local space weather. Space weather is an interdisciplinary subject covering a vast number of technological, scientific, economic and environmental issues. It is an application-oriented discipline which addresses the needs of “space weather product” users. It can be truly said that space weather affects everybody, either directly or indirectly. The aim of this paper is to give an overview of what space weather encompasses, emphasizing how solar-terrestrial physics is applied to space weather. Examples of “space weather product” users will be given highlighting those products that we as a civilization are most dependent on.
Evolution of several space weather events connected with Forbush decreases
Authors: Dorotovič I. , Kudela K. , Lorenc M. , Pintér T. , Rybanský M. 
Published: March 2009

AbstractIn our recent paper (Dorotovič et al. 2008a) we focused on a study of the Forbush decrease (FD) of January 17–18 and 21–22, 2005. It was shown that the corresponding recovery time can depend on the density of high-energy protons in the CME matter. In this paper we identified several additional events in the period between 1995 and 2007. We found that the majority of FDs studied is accompanied by an abrupt count increase in the proton channel P1 and by a simultaneous decrease in the channel P7 (GOES). However, the analysis of temporal evolution of all FDs did not confirm the hypothesis on different recovery time after FD as a function of the energy distribution of the particles penetrating into radiation belts of the Earth.
Solar and planetary dynamos: comparison and recent developments
Authors: Petrovay K. 
Published: March 2009

AbstractWhile obviously having a common root, solar and planetary dynamo theory have taken increasingly divergent routes in the last two or three decades, and there are probably few experts now who can claim to be equally versed in both. Characteristically, even in the fine and comprehensive book “The magnetic Universe” (Rudiger & Hollerbach 2004), the chapters on planets and on the Sun were written by different authors. Separate reviews written on the two topics include Petrovay (2000), Charbonneau (2005), Choudhuri (2008) on the solar dynamo and Glatzmaier (2002), Stevenson (2003) on the planetary dynamo. In the following I will try to make a systematic comparison between solar and planetary dynamos, presenting analogies and differences, and highlighting some interesting recent results.
Processes in the magnetized chromosphere of the Sun
Authors: Hasan S. S. 
Published: March 2009

AbstractWe review physical processes in magnetized chromospheres on the Sun. In the quiet chromosphere, it is useful to distinguish between the magnetic network on the boundaries of supergranules, where strong magnetic fields are organized in mainly vertical flux tubes and internetwork regions in the cell interiors, which have traditionally been associated with weak magnetic fields. Recent observations from Hinode, however, suggest that there is a significant amount of horizontal magnetic flux in the cell interior with large field strength. Furthermore, processes that heat the magnetic network have not been fully identified. Is the network heated by wave dissipation and if so, what is the nature of these waves? These and other aspects related to the role of spicules will also be highlighted. A critical assessment will be made on the challenges facing theory and observations, particularly in light of the new space experiments and the planned ground facilities.
Long period oscillations of microwave emission of solar active regions: observations with NoRH and SSRT
Authors: Bakunina I. A. , Abramov-Maximov V. E. , Lesovoy S. V. , Shibasaki K. , Solov'ev A. A. , Tikhomirov Yu. V. 
Published: March 2009

AbstractIn this work we present the first results of study and comparison of the parameters of quasi-periodic long-term oscillations of microwave emission of large (>0.7 arcmin) sunspots as a result of simultaneous observations with two radioheliographs – NoRH (17 GHz) and Siberian Solar Radio Telescope (SSRT) (5.7 GHz) with 1 minute cadence. Radioheliographs have been working with quite large time overlap (about 5 hours) and have the high spatial resolution: 10 arcsec (NoRH) and 20 arcsec (SSRT). We have found that quasi-periodic long-term oscillations are surely observed at both frequencies with the periods in the range of 20–150 min. We detected common periods for common time of observations with two radioheliographs and interpret this as the consequence of the vertical-radial quasi-periodic displacements of sunspot as a whole structure.
Enhanced Rieger type periodicities' detection in X-ray solar flares and statistical validation of Rossby waves' existence
Authors: Dimitropoulou Michaila , Moussas Xenophon , Strintzi Dafni 
Published: March 2009

AbstractThe known Rieger Periodicity (ranging in literature from 150 up to 160 days) is obvious in numerous solar indices. Many sub-harmonic periodicities have also been observed (128–, 102–, 78–, and 51 – days) in flare, sunspot, radio bursts, neutrino flux and flow data, coined as Rieger Type Periodicities (RTPs). Several attempts are focused to the discovery of their source, as well as the explanation of some intrinsic attributes that they present, such as their connection to extremely active flares, their temporal intermittency as well as their tendency to occur near solar maxima. In this paper, we link the X-ray flare observations made on Geosynchronous Operational Environmental Satellites (GOES) to an existing theoretical model (Lou 2000), suggesting that the mechanism behind the Rieger Type Periodicities is the Rossby Type Waves. The enhanced data analysis methods used in this article (Scargle-Lomb periodogram and Weighted Wavelet Z-Transform) provide the proper resolution needed to argue that RTPs are present also in less energetic flares, contrary to what has been inferred from observations so far.
Coronal mass ejection: key issues
Authors: Harrison Richard 
Published: March 2009

AbstractCoronal Mass Ejections (CMEs) have been addressed by a particularly active research community in recent years. With the advent of the International Heliophysical Year and the new STEREO and Hinode missions, in addition to the on-going SOHO mission, CME research has taken centre stage in a renewed international effort. This review aims to touch on some key observational areas, and their interpretation. First, we consider coronal dimming, which has become synonymous with CME onsets, and stress that recent advances have heralded a move from a perceived association between the two phenomena to a firm, well-defined physical link. What this means for our understanding of CME modeling is discussed. Second, with the new STEREO observations, and noting the on-going SMEI observations, it is important to review the opening field of CME studies in the heliosphere. Finally, we discuss some specific points with regard to EIT-waves and the flare-CME relationship. In the opinion of the author, these issues cover key hot topics which need consideration for significant progress in the field.
Solar prominences
Authors: Schmieder Brigitte , Aulanier Guillaume , Török Tibor 
Published: March 2009

AbstractSolar filaments (or prominences) are magnetic structures in the corona. They can be represented by twisted flux ropes in a bipolar magnetic environment. In such models, the dipped field lines of the flux rope carry the filament material and parasitic polarities in the filament channel are responsible for the existence of the lateral feet of prominences.Very simple laws do exist for the chirality of filaments, the so-called “filament chirality rules”: commonly dextral/sinistral filaments corresponding to left- (resp. right) hand magnetic twists are in the North/South hemisphere. Combining these rules with 3D weakly twisted flux tube models, the sign of the magnetic helicity in several filaments were identified. These rules were also applied to the 180° disambiguation of the direction of the photospheric transverse magnetic field around filaments using THEMIS vector magnetograph data (López Aristeet al. 2006). Consequently, an unprecedented evidence of horizontal magnetic support in filament feet has been observed, as predicted by former magnetostatic and recent MHD models.The second part of this review concerns the role of emerging flux in the vicinity of filament channels. It has been suggested that magnetic reconnection between the emerging flux and the pre-existing coronal field can trigger filament eruptions and CMEs. For a particular event, observed with Hinode/XRT, we observe signatures of such a reconnection, but no eruption of the filament. We present a 3D numerical simulation of emerging flux in the vicinity of a flux rope which was performed to reproduce this event and we briefly discuss, based on the simulation results, why the filament did not erupt.
CMEs ‘en rafale’ observations and simulations
Authors: Dumitrache Cristiana 
Published: March 2009

AbstractA CME is triggered by the disappearance of a stable equilibrium as a result of the slow evolution of the photospheric magnetic field. This disappearance may be due to a loss of ideal-MHD equilibrium or stability as in the kink mode, or to a loss of resistive-MHD equilibrium as a result of magnetic reconnection. We have obtained CMEs in sequence by a time dependent magnetohydrodynamic computation performed on three solar radii. These successive CMEs resulted from a prominence eruption. Velocities of these CMEs decrease in time, from a CME to another. We present observational evidences for large-scale magnetic reconnections that caused the destabilization of a sigmoid filament. These reconnections covered half of the solar disk and produced CMEs in squall (sequential CMEs).
The link between CME-associated dimmings and interplanetary magnetic clouds
Authors: Mandrini Cristina H. , Nakwacki María S. , Attrill Gemma , van Driel-Gesztelyi Lidia , Dasso Sergio , Démoulin Pascal 
Published: March 2009

AbstractCoronal dimmings often develop in the vicinity of erupting magnetic configurations. It has been suggested that they mark the location of the footpoints of ejected flux ropes and, thus, their magnetic flux can be used as a proxy for the ejected flux. If so, this quantity can be compared to the flux in the associated interplanetary magnetic cloud (MC) to find clues about the origin of the ejected flux rope. In the context of this interpretation, we present several events for which we have done a comparative solar-interplanetary analysis. We combine SOHO/Extreme Ultraviolet Imaging Telescope (EIT) data and Michelson Doppler Imager (MDI) magnetic maps to identify and measure the flux in the dimmed regions. We model the associated MCs and compute their magnetic flux using in situ observations. We find that the magnetic fluxes in the dimmings and MCs are compatible in some events; though this is not the case for large-scale and intense eruptions that occur in regions that are not isolated from others. We conclude that, in these particular cases, a fraction of the dimmed regions can be formed by reconnection between the erupting field and the surrounding magnetic structures, via a stepping process that can also explain other CME associated events.
Coherent emission
Authors: Melrose D. B. 
Published: March 2009

AbstractThe theory of plasma emission and of electron cyclotron maser emission, and their applications to solar radio bursts and to Jupiter's decametric radioation (DAM) and the Earth's auroral kilometric radiation (AKR) are reviewed, emphasizing the early literature and problems that remain unresolved. It is pointed out that there are quantitative measures of coherence in radio astronomy that have yet to be explored either observationally or theoretically.
On spatial variations of magnetic field and superthermal electron distribution in cm-radio burst source
Authors: Yasnov Leonid V. , Karlický Marian 
Published: March 2009

AbstractThe paper presents a new method of an estimation of spatial variations of the magnetic field and superthermal electron distribution in solar cm-radio burst sources. The method is based on the analysis of several burst spectra recorded in the different moments of time and on the minimization of the difference between the theoretical and observed radio fluxes. It is found that the measure of the spatial variations of superthermal electron distribution in the radio source is always greater than that for the magnetic field. In most cases this measure has a minimum at the impulsive phase of cm-radio bursts.
A study on the relationship of type III radio bursts CME and solar flares during the active period October-November 2003
Authors: Thanassa Michaella , Mitsakou Eleftheria , Preka-Papadema Panagiota , Moussas Xenophon , Tsitsipis Panagiotis , Kontogeorgos Athanasios 
Published: March 2009

AbstractWithin a period of intense activity (20 October to 5 November 2003), the injection and propagation of near relativistic electrons, resulted in hundreds of type III bursts recorded by the ARTEMISIV radio spectrograph (20–650 MHz). For a number of these type III events association with GOES SXR/Hα flare and/or SOHO/LASCO CME was established. We study the variation of characteristic type III parameters and their relationship with features of the associated flares and/or CMEs.