bluuebunny/crossref_metadata_2025 huggingface dataset:
Tea and non-tea flavonol intakes in relation to atherosclerotic vascular disease mortality in older women
Authors: Ivey Kerry L. , Lewis Joshua R. , Prince Richard L. , Hodgson Jonathan M.
Published: April 2013

Epidemiological studies have indicated that dietary flavonoids generally, and flavonols specifically, may contribute to cardiovascular health. Tea consumption, which is often the main dietary source of flavonoids and flavonols, is associated with a reduced risk of cardiovascular outcomes. The primary objective of the present study was to explore the association of the habitual intake of flavonols from tea and non-tea sources with the risk of atherosclerotic vascular disease mortality in a population of elderly women. A total of 1063 women, aged over 75 years, were randomly selected from ambulant Caucasian women living in Perth, Western Australia. Flavonoid consumption was assessed using the US Department of Agriculture Flavonoid, Flavone and Proanthocyanidin databases. Atherosclerotic vascular disease mortality was assessed over 5 years of follow-up through the Western Australian Data Linkage System. During the follow-up, sixty-four women died from atherosclerotic vascular disease. Women in the highest compared with the lowest tertile of flavonol intake had a lower risk of atherosclerotic vascular disease death (OR 0·27, 95 % CI 0·13, 0·59; P≤ 0·01 for trend in multivariate-adjusted models). Similar relationships were observed for flavonol intake derived from both tea (OR 0·38, 95 % CI 0·18, 0·79; P< 0·01) and non-tea (OR 0·41, 95 % CI 0·20, 0·85; P= 0·05) sources. Tea was the main contributor to flavonol intake (65 %), and the intakes of flavonols from tea and non-tea sources were not significantly correlated. In conclusion, increased consumption of flavonols was independently associated with a lower risk of atherosclerotic vascular disease mortality. Both tea and non-tea sources of flavonols were independently associated with this benefit.
Effect of vitamin D administration in vitamin D-deficient pregnant women on maternal and neonatal serum calcium and vitamin D concentrations: a randomised clinical trial
Authors: Hashemipour Sima , Lalooha Fatemeh , Zahir Mirdamadi Shabnam , Ziaee Amir , Dabaghi Ghaleh Talaat
Published: April 2013

There are several studies in which a correlation between maternal vitamin D deficiency and serum mineral disorders in the mother and the newborn has been reported. The present randomised clinical trial was designed to investigate the effect of vitamin D administration on maternal and fetal Ca and vitamin D status. The trial was carried out on 160 pregnant women. Vitamin D-deficient (25-hydroxyvitamin D (25(OH)D) < 30 ng/ml) pregnant women were recruited at 26–28 weeks of pregnancy. In the control group, a multivitamin supplement containing 400 IU vitamin D3/d was given. Patients in the treatment group were treated with 50 000 IU vitamin D3 weekly for a total duration of 8 weeks. At delivery, maternal and fetal Ca and 25(OH)D levels in both groups were compared. In total, 81 % of pregnant women were vitamin D deficient. At the time of delivery, Ca and vitamin D levels were higher in the treatment group compared with the control group (92 (sd 3) v. 85 (sd 4) mg/l, respectively, P= 0·001 for serum Ca; 47·8 (sd 11·1) v. 15·9 (sd 6·6) ng/ml, respectively, P< 0·001 for vitamin D). At the time of delivery, 32·7 % of women in the control group had hypocalcaemia, while no hypocalcaemic case was detected in the vitamin D-treated group. Mean neonatal serum 25(OH)D was higher in the treatment group compared with the control group (27·7 (sd 5·2) v.10·9 (sd 4·4) ng/ml, respectively, P< 0·01). The neonatal Ca level in the treatment group was significantly higher than that of the control group (99 (sd 3) v. 91 (sd 3) mg/l, respectively, P< 0·001). The administration of vitamin D to pregnant women with vitamin D deficiency improves both maternal and neonatal Ca levels.
Others, Spectatorship, and the Ethics of Verbatim Performance
Authors: Duggan Patrick
Published: April 2013

In this article Patrick Duggan interrogates The Paper Birds' 2010 production Others to explore the political and ethical implications of embodying the (verbatim) texts of others. Built from a six-month exchange of letters between the company and a prisoner, a celebrity (a very non-committal Heather Mills, apparently), and an Iranian artist, Others fuses live music with verbatim and physical theatre texts to investigate the ‘otherness’ of women from vastly divergent cultural contexts. With equal measures of humour and honesty the performance deconstructs these voices both to highlight their particular concerns and problems and to interrogate larger issues relating to ‘others’ with whom we have conscious or unconscious contact. The ethical implications of continuing or discontinuing the correspondences with the three women are explored, and trauma and embodiment theories are used alongside Lévinasian and Russellian theories of ethics to ask what an encounter with such others might teach us about ourselves, about the traumatized other and about the ethics of encounter within performance texts. Patrick Duggan is Lecturer in Theatre and Performance Studies at the University of Exeter. A practising director, he has also taught extensively in the UK and Ireland as well as in Germany and the United States. He is author of Trauma-Tragedy: Symptoms of Contemporary Performance (Manchester University Press, 2012) and co-edited Reverberations: Britishness, Aesthetics and Small-Scale Theatres (Intellect, 2013) and a special issue of the journal Performance Research ‘On Trauma’ (Taylor and Francis, 2011).
Disease-specific knowledge and information preferences of young patients with congenital heart disease
Authors: Lesch Wiebke , Specht Katharina , Lux Anke , Frey Michael , Utens Elisabeth , Bauer Ulrike
Published: April 2013

Aims

Persons suffering from congenital heart defects require lifelong specialist medical care. Failure to attend cardiological follow-up examinations and risky health behaviour in the transition phase may cause severe medical complications. A good level of disease-specific knowledge enhances compliance. Therefore, the study's aim was to investigate: (a) the level of disease-specific knowledge, (b) information preferences, and (c) sources of information for children, adolescents, and young adults regarding their illness.

Methods and results

In all, 596 patients, aged 10–30 years, participated in this cross-sectional survey study (response rate: 53%). All patients were already enrolled in the German National Register for Congenital Heart Defects. The main outcome measures included disease-specific knowledge, information preferences, and information sources regarding patients’ individual cardiac condition. The patients demonstrated a major knowledge gap concerning their illness and how to live with it. For all three age groups, patients’ information needs were unmet on nearly half of the topics of interest. Children's information needs were comparable to those of adolescents and adults concerning several important topics, for example, work/career, sports. Information preferences varied according to age and gender, rather than disease severity. The most important sources of information were physicians (71.0%), family and friends (58.2%), and the Internet (37.5%).

Conclusion

The study revealed substantial knowledge gaps, indicating a need for structured multidisciplinary patient education interventions. These interventions should start as early as in childhood and help patients manage their condition and assume responsibility for their own health, so that the transition phase runs smoothly.
“SANGUINARY AMUSEMENT”: E. A. FREEMAN, THE COMPARATIVE METHOD AND VICTORIAN THEORIES OF RACE
Authors: MORRISROE VICKY L.
Published: April 2013

This article seeks to revise the conventional portrait of the historian E. A. Freeman (1823–92) as an arch-racist and confident proponent of Aryan superiority. Focusing on the relatively obscureComparative Politics(1873), it is argued that, while attitudes towards race were hardening in the later nineteenth century, Freeman combined the insights of the practitioners of the Comparative Method and the Liberal Anglican philosophy of Thomas Arnold to define the Aryan race as a community of culture rather than of blood. Explicitly rejecting biological interpretations of race, Freeman and the practitioners of the Comparative Method used the Aryan concept to denote a community of languages, myths, laws and political institutions and, in recognizing the instability of culture, articulated an account of progress that was cyclical rather than unilinear. It will be demonstrated that Freeman's Aryan universalism issued in anxieties concerning the future stability of the West and a fear that recapitulation might be engendered by contemporary political expansionism and contact with the rival civilization of the despotic East.
BRIDGING THE ABYSS: VICTOR BASCH'S POLITICAL AND AESTHETIC MINDSET
Authors: HEYNICKX RAJESH
Published: April 2013

This essay cross-examines both the correlation and the disjunction between art philosophy and political reason in the thinking of the French Jewish art philosopher, Kant specialist and socialist politician Victor Basch (1863–1944). Two interwoven lines of questioning will be in play. One considers the extent to which Basch's theory of beauty, which was primarily grounded in a psychological theory ofEinfühlung, was a corollary to his political ideas and practices. The other line of inquiry raises questions about how Basch's political position, namely his anti-facist defending of republican values, became influenced by his work on aesthetics. By answering both questions, this article challenges the traditional historiography of interwar aesthetics. The esaay shows how conceptual debates of aesthetics were not just sterile theoretical products, but to a large extent offered an apparatus to diagnose and orientate a rapidly changing world. Therefore this essay develops a reflection about the gaze needed to take in the complex historical situations from which aesthetic reflections grew, and which in turn they addressed.
FROM THE ENLIGHTENMENT TO THE TERROR: NEW GENEALOGIES
Authors: DE DIJN ANNELIEN
Published: April 2013

Dan Edelstein is a prolific author. In less than two years he has produced not one but two books. His first, The Terror of Natural Right: Republicanism, the Cult of Nature, and the French Revolution, was published by The University of Chicago Press in October 2009. Its Irish twin, The Enlightenment: A Genealogy, appeared with the same press in the fall of 2010. Each of these books deals with a much-studied subject—respectively the Terror and the Enlightenment—the kind of subject, in other words, about which even the most recent literature alone can fill entire libraries. Yet in both cases, Edelstein manages to make a contribution of startling originality and importance. It is clear that this literary scholar—Edelstein is a professor of French and Italian at Stanford University—is one of the most important new voices in the field of eighteenth-century French intellectual history. In this review, I will start by discussing both of his books separately. I will then conclude with some reflections on what Edelstein's work contributes to our understanding of eighteenth-century intellectual history when read as a whole.
GREECE AND ROME IN AMERICA
Authors: RUSSO JOHN PAUL
Published: April 2013

The classics appear conspicuously in the pamphlet wars of the American Revolution, though in the opinion of Bernard Bailyn (written many years ago), their presence is “window-dressing” and their influence “superficial.” They are “everywhereillustrative, not determinative, of thought” (my italics). Up the scale in influence comes Enlightenment rationalism, also “superficial” but only “at times”—that removes the foreigners, ancient and modern. Then, further up the scale are English common-law writers, “powerfully influential” though still insufficiently “determinative”; above them, a “major source,” New England Puritan thought and culture; and finally, at the top, seventeenth-century British “heroes of liberty” and the “early eighteenth-century transmitters of this tradition,” e.g. Commonwealth men, Bishop Hoadly. Who would have thought that the bishop of Winchester weighed in the balance more heavily than Plato and Aristotle? Only once in passing does Bailyn even mention Machiavelli, to whom J. G. A. Pocock, Quentin Skinner, and Harvey C. Mansfield would grant large prominence in the development of Revolutionary thought.
ERNST CASSIRER'S MOMENT: PHILOSOPHY AND POLITICS
Authors: GREENBERG UDI
Published: April 2013

The emergence of the German Jewish philosopher Ernst Cassirer (1874–1945) as the object of scholarly attention has been both surprising and rapid. In the decades since his early death while in exile in the United States, Cassirer never fell into complete oblivion. His works remained known to specialists in German intellectual history; his participation in a famous 1929 debate with Martin Heidegger in Davos, Switzerland, one of the most iconic moments in modern Continental thought, made his name familiar to most students of modern philosophy. Yet Cassirer lacked the widespread recognition given to contemporaries such as Heidegger or Walter Benjamin, and his work never became the center of historical or philosophical study. This neglect stemmed, in part, from dismissal by his peers; as Edward Skidelsky explains in his new study, Rudolf Carnap found him “rather pastoral,” Isaiah Berlin dismissed him as “serenely innocent,” and Theodor Adorno thought he was “totally gaga” (125). The last few years, however, have seen the rise of a remarkable new interest in Cassirer in both Germany and the English-speaking world. Among this recent literature, Edward Skidelsky's and Peter Gordon's works lead the small “Cassirer renaissance” and offer the best English-language introduction to his thought. Both Gordon and Skidelsky ambitiously seek to relocate Cassirer at the forefront of modern German and European thought. Gordon goes as far as to call him “one of the greatest philosophers and intellectual historians to emerge from the cultural ferment of modern Germany” and one of the most important thinkers of the twentieth century (11). In making such bold statements, Gordon and Skidelsky clearly set their sights beyond the person himself; they aspire to highlight a central strand of thought that enjoyed a powerful presence in early twentieth-century Germany but fell into neglect in the postwar era. In doing so, they seek to reevaluate the nature and legacy of Weimar thought, its complex relationship with the period's unstable politics, and its relevance today.
Diverse stoichiometry of dissolved trace metals in the Indian Ocean
Authors: Thi Dieu Vu Huong , Sohrin Yoshiki
Published: April 2013

Trace metals in seawater are essential to organisms and important as tracers of various processes in the ocean. However, we do not have a good understanding of the global distribution and cycling of trace metals, especially in the Indian Ocean. Here we report the first simultaneous, full-depth and basin-scale section-distribution of dissolved (D) Al, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb in the Indian Ocean. Our data reveal widespread co-limitation for phytoplankton production by DFe and occurrence of redox-related processes. The stoichiometry of the DM/phosphorus ratio agrees within a factor of 5 between deep waters in the Indian and Pacific, whereas it shows variability up to a factor of 300 among water masses within the Indian Ocean. This indicates that a consistent mechanism controls the stoichiometry in the deep waters, which are significantly depleted in Mn, Fe and Co compared to requirements for phytoplankton.
Training Communication Partners of Adults Who Rely on AAC: Co-Construction of Meaning
Authors: Thiessen Amber , Beukelman David
Published: April 2013

In this article, we summarize a presentation on the training of AAC communication partners at the SIG 12 Virtual Conference (2012). We describe the characteristics of effective communication partners. We also will discuss adult learning principles and learning mode preference as they relate to training of AAC communication partners.
AAC and Communication in the Workplace
Authors: McNaughton David , Chapple David
Published: April 2013

Communication in the workplace holds many challenges for persons with complex communication needs. A better understanding of workplace communication, and the use of evidence-based strategies for supporting workplace communication by persons who use AAC, can result in improved employment outcomes.
Solar activity and its evolution across the corona: recent advances
Authors: Zuccarello Francesca , Balmaceda Laura , Cessateur Gael , Cremades Hebe , Guglielmino Salvatore L. , Lilensten Jean , Dudok de Wit Thierry , Kretzschmar Matthieu , Lopez Fernando M. , Mierla Marilena , Parenti Susanna , Pomoell Jens , Romano Paolo , Rodriguez Luciano , Srivastava Nandita , Vainio Rami , West Matt , Zuccarello Francesco P.
Published: April 2013

Solar magnetism is responsible for the several active phenomena that occur in the solar atmosphere. The consequences of these phenomena on the solar-terrestrial environment and on Space Weather are nowadays clearly recognized, even if not yet fully understood. In order to shed light on the mechanisms that are at the basis of the Space Weather, it is necessary to investigate the sequence of phenomena starting in the solar atmosphere and developing across the outer layers of the Sun and along the path from the Sun to the Earth. This goal can be reached by a combined multi-disciplinary, multi-instrument, multi-wavelength study of these phenomena, starting with the very first manifestation of solar active region formation and evolution, followed by explosive phenomena (i.e., flares, erupting prominences, coronal mass ejections), and ending with the interaction of plasma magnetized clouds expelled from the Sun with the interplanetary magnetic field and medium. This wide field of research constitutes one of the main aims of COST Action ES0803:Developing Space Weather products and services in Europe. In particular, one of the tasks of this COST Action was to investigate theProgress in Scientific Understanding of Space Weather.In this paper we review the state of the art of our comprehension of some phenomena that, in the scenario outlined above, might have a role on Space Weather, focusing on the researches, thematic reviews, and main results obtained during the COST Action ES0803.
Atraumatische anteriore Kniegelenksluxation bei
Pangonarthrose
Authors: Citak M. , Ansorge C. , Klatte T. , Klauser W. , Gehrke T. , Kendoff D.
Published: April 2013

Die Luxation des Kniegelenks ist eine schwerwiegende Verletzung, die in der
Regel nach einem Trauma auftritt. Die spontane Luxation ist dagegen eine
Rarität. Wir berichten über eine 68-jährige Patientin, bei der im Rahmen
einer elektiv geplanten Knietotalendoprothesen-(KTEP-)Implantation in der
präoperativen Diagnostik eine anteriore Luxation des Kniegelenks auffällig
war. Die radiologischen und klinischen und insbesondere die intraoperativen
Befunden deuten auf eine atraumatische Genese hin. Wir vermuten, dass die
Arthrose des Kniegelenks die Luxation herbeigeführt hat. Daher empfehlen
wir, auch beim eher „harmlosen“ Krankheitsbild der Arthrose, engmaschige
klinische und radiologische Verlaufskontrollen, um mögliche
Folgeverletzungen früh zu entdecken und adäquat zu therapieren.
Ist der distale Femurersatz als extremitätenerhaltendes Verfahren
nach komplexen Frakturen am distalen Femur geeignet?
Authors: Fakler J. , Hepp P. , Marquaß B. , von Dercks N. , Josten C.
Published: April 2013

Hintergrund: Der modulare distale Femurersatz wurde ursprünglich
entwickelt, um eine belastbare und funktionelle untere Extremität nach
Resektion gelenknaher primärer Knochentumoren mit großen knöchernen Defekten
wiederherzustellen. Ziel der vorliegenden Untersuchung war es, die
Indikationsstellung, Komplikationen und Funktion des distalen Femurersatzes
nach komplexen Frakturen oder Frakturfolgen am distalen Femur zu erfassen
und im Kontext vergleichbarer Studien zu bewerten. Patienten und
Methode: 14 Patienten wurden retrospektiv untersucht, die aufgrund
einer Fraktur oder Frakturfolgen mit ausgedehnten posttraumatischen Defekten
des distalen Femurs mit einer Megaendoprothese versorgt wurden. Das Alter
der Patienten zum Zeitpunkt der Operation betrug im Median 77,0 (IQB
70,0–81,5) Jahre (IQB: Interquartilbereich). Der mediane
Nachuntersuchungszeitraum betrug 27,0 (IQB 13,5–37,5) Monate
(Schwankungsbereich 10–49 Monate). Ergebnisse: Die Indikation zum
distalen Femurersatz wurde in 3 Fällen nach periprothetischer Fraktur
gestellt. In 3 Fällen war die Indikation eine Komplikation nach
Osteosynthese einer periprothetischen Fraktur, in 8 Fällen waren
Komplikationen nach Osteosynthese distaler Femurfrakturen der Grund für
einen distalen Femurersatz. Die Implantation des distalen Femurersatzes
erfolgte bei 5 Patienten zweizeitig, nachdem eine implantatassoziierte
Infektion saniert wurde. Der Knee Society Score verbesserte sich im Median
von präoperativ 20,0 (IQB 7,5–30,0) signifikant auf 80,0 (IQB 62,3–89,0) zum
Zeitpunkt der Nachuntersuchung (p < 0,001). Komplikationen, die eine
operative Revision erforderten, waren bei 7 der 14 Patienten (50 %)
aufgetreten. Bei 2 Patienten traten Wundheilungsstörungen oder
oberflächliche Infektionen auf, die chirurgisch behandelt werden mussten.
Eine Ruptur des Streckapparats trat bei 1 Patientin auf, die sich im
weiteren Verlauf auch eine periprothetische Fraktur zuzog. Bei 1 Patienten
wurde eine frühzeitige Lockerung der femoralen Prothesenkomponente
festgestellt. Die häufigste Komplikation war eine periprothetische Fraktur
bei 4 Patienten. Drei Patienten verstarben ohne Zusammenhang zur
Prothesenimplantation. Schlussfolgerung: Der distale Femurersatz ist
eine wichtige Behandlungsoption zur Wiederherstellung einer funktionell
belastbaren unteren Extremität bei ausgedehnten traumatischen und
posttraumatischen Defekten. Insbesondere ältere Patienten erreichen dadurch
in der überwiegenden Mehrzahl wieder ihre Gehfähigkeit. Die relativ hohe
Komplikationsrate erfordert eine sehr sorgfältige Indikationsstellung.
Stability analysis of Reynolds stress response functional candidates
Authors: Dafinger M. , Hallatschek K. , Itoh K.
Published: April 2013

Complete information on the behavior of zonal flows in turbulence systems is coded in the turbulent stress response to the respective flow pattern. We show that turbulence stress response functionals containing only the linear first order wavenumber dependence on the flow pattern result in unstable structures up to the system size. A minimal augmentation to reproduce the flow patterns observed in turbulence simulations is discussed.
Millimeter wave scattering and diffraction in 110 GHz air breakdown plasma
Authors: Cook Alan M. , Hummelt Jason S. , Shapiro Michael A. , Temkin Richard J.
Published: April 2013

We present measurements of the scattering, reflection, absorption, and transmission of a 1.5 MW, 110 GHz quasioptical gyrotron beam by a self-induced air breakdown plasma. The breakdown forms a periodic array of plasma filaments, oriented parallel to the incident electric field polarization that propagates toward the microwave source. For incident intensity of 3 MW/cm2, calorimetric measurements show that as much as 45% of the full beam power is absorbed by the plasma, averaged over the pulse, 1% is reflected backward, and the remainder is transmitted and also scattered into a wide angular spread. We observe that approximately 10 times more power is scattered in the direction perpendicular to the filaments than parallel. The far-field angular distribution of transmitted power exhibits a diffraction pattern that changes throughout the 2-μs life of the plasma.
Viscous potential flow analysis of electrified miscible finitely conducting fluid through porous media
Authors: Obied Allah M. H.
Published: April 2013

In this work, a viscous potential flow analysis is used to investigate capillary surface waves between two horizontal finite fluid layers. The two layers have finite conductivities and admit mass and heat transfer. A general dispersion relation is derived. The presence of finite conductivities together with the dielectric permeabilities makes the horizontal electric field play a dual role in the stability criterion. The phenomenon of negative viscosity is observed. A new growth rate parameter, depending on the kinematical viscosity of the lower fluid layer, is found and has a stabilizing effect on the unstable modes. The growth rates and neutral stability curve are given and applied to air-water interface. The effects of various parameters are discussed for the Kelvin-Helmholtz and the Rayleigh-Taylor instabilities.
Jump conditions in transonic equilibria
Authors: Guazzotto L. , Betti R. , Jardin S. C.
Published: April 2013

In the present paper, the numerical calculation of transonic equilibria, first introduced with the FLOW code in Guazzotto et al. [Phys. Plasmas 11, 604 (2004)], is critically reviewed. In particular, the necessity and effect of imposing explicit jump conditions at the transonic discontinuity are investigated. It is found that “standard” (low-β, large aspect ratio) transonic equilibria satisfy the correct jump condition with very good approximation even if the jump condition is not explicitly imposed. On the other hand, it is also found that high-β, low aspect ratio equilibria require the correct jump condition to be explicitly imposed. Various numerical approaches are described to modify FLOW to include the jump condition. It is proved that the new methods converge to the correct solution even in extreme cases of very large β, while they agree with the results obtained with the old implementation of FLOW in lower-β equilibria.
Group velocity dispersion and relativistic effects on the wakefield induced by chirped laser pulse in parabolic plasma channel
Authors: Sohbatzadeh F. , Akou H.
Published: April 2013

The excitation of wake field plasma waves by a short laser pulse propagating through a parabolic plasma channel is studied. The laser pulse is assumed to be initially chirped. In this regard, the effects of initial and induced chirp on the plasma wake field as well as the laser pulse parameters are investigated. The group velocity dispersion and nonlinear relativistic effects were taken into account to evaluate the excited wake field in two dimension using source dependent expansion method. Positive, negative, and un-chirped laser pulses were employed in numerical code to evaluate the effectiveness of the initial chirp on 2-D wake field excitation. Numerical results showed that for laser irradiances exceeding 1018W/cm2, an intense laser pulse with initial positive chirp generates larger wake field compared to negatively and un-chirped pulses.
Collisionless shock formation, spontaneous electromagnetic fluctuations, and streaming instabilities
Authors: Bret A. , Stockem A. , Fiuza F. , Ruyer C. , Gremillet L. , Narayan R. , Silva L. O.
Published: April 2013

Collisionless shocks are ubiquitous in astrophysics and in the lab. Recent numerical simulations and experiments have shown how they can arise from the encounter of two collisionless plasma shells. When the shells interpenetrate, the overlapping region turns unstable, triggering the shock formation. As a first step towards a microscopic understanding of the process, we analyze here in detail the initial instability phase. On the one hand, 2D relativistic Particle-In-Cell simulations are performed where two symmetric initially cold pair plasmas collide. On the other hand, the instabilities at work are analyzed, as well as the field at saturation and the seed field which gets amplified. For mildly relativistic motions and onward, Weibel modes govern the linear phase. We derive an expression for the duration of the linear phase in good agreement with the simulations. This saturation time constitutes indeed a lower-bound for the shock formation time.
Shock wave refraction enhancing conditions on an extended interface
Authors: Markhotok A. , Popovic S.
Published: April 2013

We determined the law of shock wave refraction for a class of extended interfaces with continuously variable gradients. When the interface is extended or when the gas parameters vary fast enough, the interface cannot be considered as sharp or smooth and the existing calculation methods cannot be applied. The expressions we derived are general enough to cover all three types of the interface and are valid for any law of continuously varying parameters. We apply the equations to the case of exponentially increasing temperature on the boundary and compare the results for all three types of interfaces. We have demonstrated that the type of interface can increase or inhibit the shock wave refraction. Our findings can be helpful in understanding the results obtained in energy deposition experiments as well as for controlling the shock–plasma interaction in other settings.
Injection and transport properties of fast electrons in ultraintense laser-solid interactions
Authors: Coury M. , Carroll D. C. , Robinson A. P. L. , Yuan X. H. , Brenner C. M. , Burza M. , Gray R. J. , Lancaster K. L. , Li Y. T. , Lin X. X. , MacLellan D. A. , Powell H. , Quinn M. N. , Tresca O. , Wahlström C.-G. , Neely D. , McKenna P.
Published: April 2013

Fast electron injection and transport in solid foils irradiated by sub-picosecond-duration laser pulses with peak intensity equal to 4×1020 W/cm2 is investigated experimentally and via 3D simulations. The simulations are performed using a hybrid-particle-in-cell (PIC) code for a range of fast electron beam injection conditions, with and without inclusion of self-generated resistive magnetic fields. The resulting fast electron beam transport properties are used in rear-surface plasma expansion calculations to compare with measurements of proton acceleration, as a function of target thickness. An injection half-angle of ∼50°−70° is inferred, which is significantly larger than that derived from previous experiments under similar conditions.
Toroidal momentum transport in a tokamak caused by symmetry breaking parallel derivatives
Authors: Sung T. , Buchholz R. , Casson F. J. , Fable E. , Grosshauser S. R. , Hornsby W. A. , Migliano P. , Peeters A. G.
Published: April 2013

A new mechanism for toroidal momentum transport in a tokamak is investigated using the gyro-kinetic model. First, an analytic model is developed through the use of the ballooning transform. The terms that generate the momentum transport are then connected with the poloidal derivative of the ballooning envelope, which are one order smaller in the normalised Larmor radius, compared with the derivative of the eikonal. The mechanism, therefore, does not introduce an inhomogeneity in the radial direction, in contrast with the effect of profile shearing. Numerical simulations of the linear ion temperature gradient mode with adiabatic electrons, retaining the finite ρ* effects in the E × B velocity, the drift, and the gyro-average, are presented. The momentum flux is found to be linear in the normalised Larmor radius (ρ*) but is, nevertheless, generating a sizeable counter-current rotation. The total momentum flux scales linear with the aspect ratio of the considered magnetic surface, and increases with increasing magnetic shear, safety factor, and density and temperature gradients.
Modeling of long range frequency sweeping for energetic particle modes
Authors: Nyqvist R. M. , Breizman B. N.
Published: April 2013

Long range frequency sweeping events are simulated numerically within a one-dimensional, electrostatic bump-on-tail model with fast particle sources and collisions. The numerical solution accounts for fast particle trapping and detrapping in an evolving wave field with a fixed wavelength, and it includes three distinct collisions operators: Drag (dynamical friction on the background electrons), Krook-type collisions, and velocity space diffusion. The effects of particle trapping and diffusion on the evolution of holes and clumps are investigated, and the occurrence of non-monotonic (hooked) frequency sweeping and asymptotically steady holes is discussed. The presented solution constitutes a step towards predictive modeling of frequency sweeping events in more realistic geometries.
A repetitive 0.14 THz relativistic surface wave oscillator
Authors: Wang Guangqiang , Wang Jianguo , Tong Changjiang , Li Xiaoze , Wang Xuefeng , Li Shuang , Lu Xicheng
Published: April 2013

Preliminary experimental results of a repetitive 0.14 THz overmoded relativistic surface wave oscillator (RSWO) are presented in this paper. The repetitive RSWO is developed by using a rectangularly corrugated slow-wave structure with overmoded ratio of 3 and a foilless diode emitting annular electron beam with thickness of 0.5 mm. The high quality electron beams at the repetition rate of 10 are obtained over a wide range of diode voltage (180 kV < U < 240 kV) and current (700 A < I < 1.2 kA). The generation experiments of RSWO are conducted at an axial pulsed magnetic field whose maximum strength and duration can reach about 2.7 T and 1 s, respectively. The experimental results show that the RSWO successfully produces reasonable uniform terahertz pulses at repetition rate of 10, and the pulse duration, frequency, and power of a single pulse are about 1.5 ns, 0.154 THz, and 2.6 MW, respectively, whereas the dominated radiation mode of the RSWO is TM02.
Nonlinear dynamics of multiple neoclassical tearing modes in tokamaks
Authors: Chandra D. , Agullo O. , Benkadda S. , Garbet X. , Sen A.
Published: April 2013

Numerical simulations investigating the interaction of co-existent 2/1 and 3/1 neoclassical tearing modes are presented. The results obtained from an initial value 3D toroidal code that solves a set of generalized reduced MHD equations exhibit a host of complex phenomena arising from the coupling of the two modes. These include a modification of the island saturation widths of the two modes, a significant modification in the perpendicular flow patterns in the vicinity of the islands, and the excitation of geodesic acoustic mode like oscillations that lead to concomitant oscillations in the kinetic and magnetic energies of the islands. These oscillations only occur in the presence of the neoclassical stress tensor contribution and are absent for two coupled classical tearing modes.
On the linear stability of collisionless microtearing modes
Authors: Predebon I. , Sattin F.
Published: April 2013

Microtearing modes are an important drive of turbulent heat transport in present-day fusion plasmas. We investigate their linear stability under very-low collisionality regimes, expected for the next generations of devices, using gyrokinetic and drift-kinetic approaches. At odds with current opinion, we show that collisionless microtearing instabilities may occur in certain experimental conditions, particularly relevant for such devices as reversed field pinches and spherical tokamaks.
Robustness of predator-prey models for confinement regime transitions in fusion plasmas
Authors: Zhu H. , Chapman S. C. , Dendy R. O.
Published: April 2013

Energy transport and confinement in tokamakfusion plasmas is usually determined by the coupled nonlinear interactions of small-scale drift turbulence and larger scale coherent nonlinear structures, such as zonal flows, together with free energy sources such as temperature gradients. Zero-dimensional models, designed to embody plausible physical narratives for these interactions,can help to identify the origin of enhanced energy confinement and of transitions between confinement regimes. A prime zero-dimensional paradigm is predator-prey or Lotka-Volterra. Here, we extend a successful three-variable (temperature gradient; microturbulence level; one class of coherent structure) model in this genre [M. A. Malkov and P. H. Diamond, Phys. Plasmas 16,012504 (2009)], by adding a fourth variable representing a second class of coherent structure. This requires a fourth coupled nonlinear ordinary differential equation. We investigate the degree of invariance of the phenomenology generated by the model of Malkov and Diamond, given this additional physics. We study and compare the long-time behaviour of the three-equation and four-equation systems, their evolution towards the final state, and their attractive fixed points and limit cycles. We explore the sensitivity of paths to attractors. It is found that, for example, an attractive fixed point of the three-equation system can become a limit cycle of the four-equation system. Addressing these questions which we together refer to as “robustness” for convenience is particularly important for models which,as here, generate sharp transitions in the values of system variables which may replicate some key features of confinement transitions. Our results help to establish the robustness of the zero-dimensional model approach to capturing observed confinement phenomenology in tokamakfusion plasmas.
Annealing induced superconductivity in perovskite-related iron-based mixed anion compounds Sr2VFeAsO3−δ
Authors: Tojo Yujiro , Matoba Masanori , Kamihara Yoichi
Published: April 2013

Polycrystalline samples of Sr2VFeAsO3−δ with perovskite-type carrier blocking layers were prepared by a solid state reaction using an alumina tube in a sealed silica tube. Sr2VFeAsO3−δ samples which were prepared as nominally δ = 0 were not synthesized as a single phase, suggesting that finite oxygen deficiency is inevitable for the compound. Although a sample, which exhibits relatively larger lattice volume, does not exhibit bulk superconductivity at temperatures ≥5 K, finite superconducting transition temperatures appear in the sample which exhibits smaller lattice volumes. These results support making the electronic and magnetic phase diagram of Sr2VFeAsO3−δ.
Pitch angle scattering of an energetic magnetized particle by a circularly polarized electromagnetic wave
Authors: Bellan P. M.
Published: April 2013

The interaction between a circularly polarized wave and an energetic gyrating particle is described using a relativistic pseudo-potential that is a function of the frequency mismatch. Analysis of the pseudo-potential provides a means for interpreting numerical results. The pseudo-potential profile depends on the initial mismatch, the normalized wave amplitude, and the initial angle between the wave magnetic field and the particle perpendicular velocity. For zero initial mismatch, the pseudo-potential consists of only one valley, but for finite mismatch, there can be two valleys separated by a hill. A large pitch angle scattering of the energetic electron can occur in the two-valley situation but fast scattering can also occur in a single valley. Examples relevant to magnetospheric whistler waves show that the energetic electron pitch angle can be deflected 5°towards the loss cone when transiting a 10 ms long coherent wave packet having realistic parameters.
Experimental and computational study of the injection of antiprotons into a positron plasma for antihydrogen production
Authors: Amole C. , Ashkezari M. D. , Baquero-Ruiz M. , Bertsche W. , Butler E. , Capra A. , Cesar C. L. , Charlton M. , Deller A. , Eriksson S. , Fajans J. , Friesen T. , Fujiwara M. C. , Gill D. R. , Gutierrez A. , Hangst J. S. , Hardy W. N. , Hayden M. E. , Isaac C. A. , Jonsell S. , Kurchaninov L. , Little A. , Madsen N. , McKenna J. T. K. , Menary S. , Napoli S. C. , Olchanski K. , Olin A. , Pusa P. , Rasmussen C. Ø. , Robicheaux F. , Sarid E. , Shields C. R. , Silveira D. M. , So C. , Stracka S. , Thompson R. I. , van der Werf D. P. , Wurtele J. S. , Zhmoginov A. ,   (ALPHA collaboration), Friedland L.
Published: April 2013

One of the goals of synthesizing and trapping antihydrogen is to study the validity of charge–parity–time symmetry through precision spectroscopy on the anti-atoms, but the trapping yield achieved in recent experiments must be significantly improved before this can be realized. Antihydrogen atoms are commonly produced by mixing antiprotons and positrons stored in a nested Penning-Malmberg trap, which was achieved in ALPHA by an autoresonant excitation of the antiprotons, injecting them into the positron plasma. In this work, a hybrid numerical model is developed to simulate antiproton and positron dynamics during the mixing process. The simulation is benchmarked against other numerical and analytic models, as well as experimental measurements. The autoresonant injection scheme and an alternative scheme are compared numerically over a range of plasma parameters which can be reached in current and upcoming antihydrogen experiments, and the latter scheme is seen to offer significant improvement in trapping yield as the number of available antiprotons increases.
Propagation of cylindrical lower hybrid drift solitary wave in an inhomogeneous plasma
Authors: Liu Hai-Feng , Wang Shi-Qing , Li Ke-Hua , Wang Zhan-He , Zhang Wei-Bing , Wang Zhi-Long , Qiang-Xiang  , Kai-Huang  , Yao-Liu  , Sili-Li  , Yang Fa-Zhan , Lan-Chang
Published: April 2013

The nonlinear cylindrical lower hybrid drift solitary wave in an inhomogeneous, magnetized plasma with the combined effects of electron density inhomogeneity and electron temperature inhomogeneity is investigated in a two-fluid model. The amplitude and width of the solitary wave are found to decrease as the electronic density inhomogeneity increases. When the electron temperature inhomogeneity grows, the amplitude of the soliton decays and the width never changes. It is noted that the decrease of diamagnetic drift velocity will strengthen the cylindrical lower hybrid drift solitary wave height and width.
Numerical study of He/CF3I pulsed discharge used to produce iodine atom in chemical oxygen-iodine laser
Authors: Zhang Jiao , Wang Yanhui , Duo Liping , Li Guofu , Wang Dezhen
Published: April 2013

The pulsed discharge for producing iodine atoms from the alkyl and perfluoroalky iodides (CH3I, CF3I, etc.) is the most efficient method for achieving the pulse operating mode of a chemical oxygen-iodine laser. In this paper, a one-dimensional fluid model is developed to study the characteristics of pulsed discharge in CF3I-He mixture. By solving continuity equation, momentum equation, Poisson equation, Boltzmann equation, and an electric circuit equation, the temporal evolution of discharge current density and various discharge products, especially the atomic iodine, are investigated. The dependence of iodine atom density on discharge parameters is also studied. The results show that iodine atom density increases with the pulsed width and pulsed voltage amplitude. The mixture ratio of CF3I and helium plays a more significant role in iodine atom production. For a constant voltage amplitude, there exists an optimal mixture ratio under which the maximum iodine atom concentration is achieved. The bigger the applied voltage amplitude is, the higher partial pressure of CF3I is needed to obtain the maximum iodine atom concentration.
Effect of electro-osmotic flow on energy conversion on superhydrophobic surfaces
Authors: Seshadri Gowrishankar , Baier Tobias
Published: April 2013

It has been suggested that superhydrophobic surfaces, due to the presence of a no-shear zone, can greatly enhance transport of surface charges, leading to a considerable increase in the streaming potential. This could find potential use in micro-energy harvesting devices. In this paper, we show using analytical and numerical methods, that when a streaming potential is generated in such superhydrophobic geometries, the reverse electro-osmotic flow and hence current generated by this, is significant. A decrease in streaming potential compared to what was earlier predicted is expected. We also show that, due to the electro-osmotic streaming-current, a saturation in both the power extracted and efficiency of energy conversion is achieved in such systems for large values of the free surface charge densities. Nevertheless, under realistic conditions, such microstructured devices with superhydrophobic surfaces have the potential to even reach energy conversion efficiencies only achieved in nanostructured devices so far.
Kinetic effects on robustness of electron magnetohydrodynamic structures
Authors: Hata M. , Sakagami H. , Das A.
Published: April 2013

Following recent remarkable progress in the development of high-power short-pulse lasers, exploration is ongoing into hitherto unknown phenomena at fast time scales of electrons, the understanding of which is becoming crucial. For a simplified description of such phenomena, the Electron Magnetohydrodynamics (EMHDs) fluid description is often adopted. For the possibility of electron transport in high-density plasma, exact solutions of the EMHD model in the form of electron vortex currents, together with their associated magnetic fields, have been considered. However, the fluid EMHD model does not incorporate kinetic effects. Here, the finite Larmor radius effects owing to a finite electron temperature on the robustness of the exact EMHD structures are investigated using two-dimensional particle-in-cell simulations. It is found that larger EMHD vortex structures can sustain themselves for long periods, even in high temperature plasma; however, sustaining structures at higher temperatures tends to be difficult. With increasing temperature, electrons with finite Larmor radii become disengaged from the localized region. It is also shown that structures localized in smaller regions are more difficult to sustain. A quantitative criterion in terms of the structure size and Larmor radius has been established by simulations over a wide range of parameters. Finally, we conclude that a structure, larger than about eight times the typical Larmor radius at r=R, could form and exist even under the effects of finite electron temperature.
Zonal flow generation and its feedback on turbulence production in drift wave turbulence
Authors: Pushkarev Andrey V. , Bos Wouter J. T. , Nazarenko Sergey V.
Published: April 2013

Plasma turbulence described by the Hasegawa-Wakatani equations is simulated numerically for different models and values of the adiabaticity parameter C. It is found that for low values of C turbulence remains isotropic, zonal flows are not generated and there is no suppression of the meridional drift waves and particle transport. For high values of C, turbulence evolves towards highly anisotropic states with a dominant contribution of the zonal sector to the kinetic energy. This anisotropic flow leads to a decrease of turbulence production in the meridional sector and limits the particle transport across the mean isopycnal surfaces. This behavior allows to consider the Hasegawa-Wakatani equations a minimal PDE model, which contains the drift-wave/zonal-flow feedback loop mechanism.
Type II–type I conversion of GaAs/GaAsSb heterostructure energy spectrum under optical pumping
Authors: Morozov S. V. , Kryzhkov D. I. , Yablonsky A. N. , Antonov A. V. , Kuritsin D. I. , Gaponova D. M. , Sadofyev Yu. G. , Samal N. , Gavrilenko V. I. , Krasilnik Z. F.
Published: April 2013

We present the experimental results of time-resolved photoluminescence spectroscopy in type II GaAs/GaAs0.64Sb0.36 quantum well heterostructures. At moderate optical excitation densities (below 103 W/cm2), we observe blue shift of the photoluminescence peak with increasing pump power which results from band bending at the type II heterointerface due to photo-excited charge carriers. With further increase in the excitation density, the observed peak undergoes red shift accompanied by significant drop in the luminescence decay time (from 10 ns to 1 ns) which is caused by extreme band bending and increasing contribution of type I radiative transitions to the photoluminescence signal.