bluuebunny/crossref_metadata_2025 huggingface dataset:
A Bibliographical Index of Mahānubhāva Works in Marathi
Authors: Raeside I. M. P.
Published: January 2010

The two principal obstacles to the study of the older forms of Marathi language and literature are the shortage of definitive texts of early works and the dearth of critical bibliographies from which one might discover what texts are available and in what form they exist. Date's Marāṭhī-grantha-sūc¯ is of course invaluable for anything published before 1937, but even this work is not exhaustive and the idiosyncrasies of its arrangement according to subject-matter make it sometimes difficult to discover how many of the works of any particular early writer exist in printed form. For an unpublished work, unless one is fortunate enough to find it in the British Museum or India Office Library catalogues of Marathi MSS, one can only consult the index of a general history of Marathi literature such as V. L. Bhave's Mahārāṣṭstra-sārasvata. There one may well find numerous references to and quotations from the work in question, but only exceptionally will there be any indication of the source of these quotations. One is left to conjecture whether they are from a MS belonging to the author or from some early printed pothī that has escaped the attention of Date. On occasions the same quotation is repeated in a different part of the book with substantial variations in its text, and when a work is described but not quoted one can never be sure whether it is in fact extant or whether description and perhaps even short quotations are not taken from some intermediate secondary source or commentary.
A Study of Fortification in the Indian Subcontinent from the Thirteenth to the Eighteenth Century A.D.
Authors: Burton-Page J.
Published: January 2010

The study of fortification in the Indian subcontinent is a discipline not only of intrinsic merit but also of considerable extrinsic value, for the material it may be expected to yield is of relevance to the archæologist, antiquarian, and historian, taking these terms in the broadest sense; indeed, it is these, in somewhat narrower terms perhaps, who have helped to amass the not inconsiderable body of material which is at present available on the fortified sites in the subcontinent, most of which have long been known to archæologists and art-historians. The old series of Archæological Survey of India Reports (1862–84), largely reports of tours by Cunningham and his associates, contain much material on the major fortified sites of the subcontinent, although some of this is merely incidental to the main purposes of the reports; the New Imperial Series of the Archæological Survey, including the regional surveys, presents more precise and detailed description of individual sites, and this is supplemented by the Archæological Survey of India Annual Reports, from 1902 onwards, and the reports of various states with autonomous departments of archæology, most notably the Nizām's Dominions whose sometime Director, Dr. Ghulam Yazdani, has in addition to considerable work on the Deccan sites published in those reports produced two valuable monographs. These works have supplemented the evidence of the sites themselves with the available historical material, documentary and epigraphic, and further epigraphic material is available in the volumes of Epigraphia indica and Epigraphia indo-moslemica, as well as in some of the Memoirs of the A.S.I. Less reliable technically, but always useful and often suggestive, is the information available in the gazetteers of the various provincial governments and states. The journals of learned societies with an Indian interest add more to this material, as do the catalogues and journals of Indian museums.
A chalice from Venice for Emperor Dāwit of Ethiopia
Authors: Heldman Marilyn E.
Published: January 2010

The various documents concerning Emperor Dāwit's embassy to the Republic of Venice in 1402 have been brought together in Carlo Conti Rossini's article of 1927 on European influence upon Ethiopian art before the coming of Jesuit missionaries in the mid sixteenth century. The purpose of this brief paper is to expand the story of Dāwit's embassy with a short document, which sheds some light upon the motives for this and subsequent Ethiopian embassies to European nations during the period before the Adalite invasions that began in 1529.
The authenticity of the Caitanyacaritāmṛtamahākāvya
Authors: Brzezinski J. K.
Published: January 2010

Until recently, Kavi Karṇapūra has generally been accepted without question as the author of a book on the life of Śrī Kṛṣṇa Caitanya entitled ŚrīCaitanyacaritāmṛtamahākāvya [CCMK]. The date of this work is given as 1542 by the author himself in its final verse. In the two penultimate verses of the work, he identifies himself as the youngest son of Śivānanda Sena and as a mere child (śiśu). If Kavi Karṇapūra is indeed the author, it is certainly a matter of great interest as he is one of the most prolific and authoritative writers amongst the followers of Caitanya. His father, Śivānanda Sena, was a rich and influential devotee of Caitanya, responsible for the management of the yearly trips to Puri which played such an important role in the latter part of the great saint's life. Unfortunately, with the exception of a few such autobiographical words in Karṇapūra's own compositions, such as the Ānandavṛndāvanacampū [AVC], Caitanyacandrodayanāṭaka [CCN] and Gauragaṇoddeśadīpikā [GGD] the only information that we have about Karṇapūra's life is from Kṛṣṇadāsa Kavirāja's Caitanyacaritāmṛta [CC].
Professor Eugenie J. A. Henderson: a personal note
Authors: Shorto H. L.
Published: January 2010

South-East Asia forty five years ago, with more than a hundred languages of six distinct stocks, only a handful of which had been even passably described, offered an unparalleled opportunity to linguistic inquiry. In opening up this field Eugénie Henderson, who died aged 74 on 27 July 1989, was the acknowledged leader in this country and widely respected outside it.
Relativity in the IERS Conventions
Authors: Petit Gérard
Published: January 2010

In the last years, a fully general relativistic definition of reference systems and of their application to astronomy and geodesy has been passed into Resolutions of the scientific unions, following work of several working groups and of the community at large. In this community, the role of the International Earth Rotation and Reference systems Service (IERS) is to generate the terrestrial and celestial reference systems and the transformation between them, and the IERS Conventions provide the set of models and procedures used in the generation of IERS products. It is therefore essential that the IAU framework for relativity is introduced in the IERS Conventions, and that this is done consistently and completely throughout the document. The paper reviews relativistic aspects in the IERS Conventions and presents recent and on-going work aiming at providing a complete and consistent presentation for a new reference edition of the IERS Conventions, expected to appear in the next year.
Reference frames and the physical gravito-electromagnetic analogy
Authors: Costa L. Filipe O. , Herdeiro Carlos A. R.
Published: January 2010

The similarities between linearized gravity and electromagnetism are known since the early days of General Relativity. Using an exact approach based on tidal tensors, we show that such analogy holds only on very special conditions and depends crucially on the reference frame. This places restrictions on the validity of the “gravito-electromagnetic” equations commonly found in literature.
Relativistic description of astronomical objects in multiple reference systems
Authors: Xu Chongming , Tang Zhenghong
Published: January 2010

Many astronomical systems require for their description in the frame of Einstein's theory of gravity not just one but several reference systems. In the first post-Newtonian approximation the Damour-Soffel-Xu (DSX) formalism presents a new and improved treatment of celestial mechanics and astronomical reference systems for the gravitational N-body problem. In the DSX-formalism the astronomical bodies are characterized by their Blanchet-Damour (BD) mass- and spin-multipole moments. However, the time dependence of these moments requires additional dynamical equations, usually local flow equations describing the internal motions inside the bodies or additional assumptions about them. In this article the internal motion of astronomical bodies will be adressed within the 1st post-Newtonian approximation to Einstein's theory of gravity. A concept of quasi-rigid bodies will be introduced; after that, astronomical fluid and elastic bodies will be discussed.
The celestial reference frame stability and apparent motions of the radio sources
Authors: Zharov V. E. , Sazhin M. V. , Sementsov V. N. , Kuimov K. V. , Sazhina O. S. , Ashimbaeva N. T.
Published: January 2010

Time series of the coordinates of the ICRF radio sources were analyzed. It was shown that part of radio sources, including even the so-called “defining” sources, show a the significant apparent motion. Corrections for their a priori coordinates are time functions. The celestial reference frame stability is provided by the no-net-rotation condition applied to the selected subset of sources, which leads in our case to a rotation of the frame axes with time. Parameters of this rotation were calculated for different subsets of sources.

To improve stability of the celestial reference frame new methods of selection of the extragalactic radio sources were suggested. The first one was called “cosmological” and the second one “kinematical”. It was shown that a selected subset of the ICRF sources, according to cosmological criteria, determines the most stable coordinate system during next decade.
Astronomical tests of relativity: beyond parameterized post-Newtonian formalism (PPN), to testing fundamental principles
Authors: Kreinovich Vladik
Published: January 2010

By the early 1970s, the improved accuracy of astrometric and time measurements enabled researchers not only to experimentally compare relativistic gravity with the Newtonian predictions, but also to compare different relativistic gravitational theories (e.g., the Brans-Dicke Scalar-Tensor Theory of Gravitation). For this comparison, Kip Thorne and others developed the Parameterized Post-Newtonian Formalism (PPN), and derived the dependence of different astronomically observable effects on the values of the corresponding parameters.

Since then, all the observations have confirmed General Relativity. In other words, the question of which relativistic gravitation theory is in the best accordance with the experiments has been largely settled. This does not mean that General Relativity is the final theory of gravitation: it needs to be reconciled with quantum physics (into quantum gravity), it may also need to be reconciled with numerous surprising cosmological observations, etc. It is, therefore, reasonable to prepare an extended version of the PPN formalism, that will enable us to test possible quantum-related modifications of General Relativity.

In particular, we need to include the possibility of violating fundamental principles that underlie the PPN formalism but that may be violated in quantum physics, such as scale-invariance, T-invariance, P-invariance, energy conservation, spatial isotropy violations, etc. In this paper, we present the first attempt to design the corresponding extended PPN formalism, with the (partial) analysis of the relation between the corresponding fundamental physical principles.
Units of relativistic time scales and associated quantities
Authors: Klioner S. A. , Capitaine N. , Folkner W. M. , Guinot B. , Huang T.-Y. , Kopeikin S. M. , Pitjeva E. V. , Seidelmann P. K. , Soffel M. H.
Published: January 2010

This note suggests nomenclature for dealing with the units of various astronomical quantities that are used with the relativistic time scales TT, TDB, TCB and TCG. It is suggested to avoid wordings like “TDB units” and “TT units” and avoid contrasting them to “SI units”. The quantities intended for use with TCG, TCB, TT or TDB should be called “TCG-compatible”, “TCB-compatible”, “TT-compatible” or “TDB-compatible”, respectively. The names of the units second and meter for numerical values of all these quantities should be used without any adjectives. This suggestion comes from a special discussion forum created within IAU Commission 52 “Relativity in Fundamental Astronomy”.
EPM ephemerides and relativity
Authors: Pitjeva E. V.
Published: January 2010

In the seventies of the last century the EPM ephemerides (Ephemerides of Planets and the Moon) of IAA RAS originated and have been developed since that time. These ephemerides are based upon relativistic equations of motion of celestial bodies and light rays and upon relativistic time scales. The updated model of EPM2008 includes the new values of planet masses and other constants, the improved dynamical model with adding Trans–Neptunian Objects and the expanded database (1913–2008). More than 260 parameters have been determined while improving the planetary part of EPM2008 to 550000 observations. EPM2008 have been oriented to ICRF by including into the total solution the VLBI data of spacecraft near the planets. The real uncertainty of EPM ephemerides has been checked by comparison with the JPL's DE ephemerides. Some estimates of the post–model parameters have been obtained: |1−β| < 0.0002, |1−γ| < 0.0002, /G = (−5.9±4.4) ⋅ 10−14 per year, the statistic zero corrections to the planet perihelion advances.
Astrometric solar-system anomalies
Authors: Anderson John D. , Nieto Michael Martin
Published: January 2010

There are at least four unexplained anomalies connected with astrometric data. Perhaps the most disturbing is the fact that when a spacecraft on a flyby trajectory approaches the Earth within 2000 km or less, it often experiences a change in total orbital energy per unit mass. Next, a secular change in the astronomical unit AU is definitely a concern. It is reportedly increasing by about 15 cm yr−1. The other two anomalies are perhaps less disturbing because of known sources of nongravitational acceleration. The first is an apparent slowing of the two Pioneer spacecraft as they exit the solar system in opposite directions. Some astronomers and physicists, including us, are convinced this effect is of concern, but many others are convinced it is produced by a nearly identical thermal emission from both spacecraft, in a direction away from the Sun, thereby producing acceleration toward the Sun. The fourth anomaly is a measured increase in the eccentricity of the Moon's orbit. Here again, an increase is expected from tidal friction in both the Earth and Moon. However, there is a reported unexplained increase that is significant at the three-sigma level. It is prudent to suspect that all four anomalies have mundane explanations, or that one or more anomalies are a result of systematic error. Yet they might eventually be explained by new physics. For example, a slightly modified theory of gravitation is not ruled out, perhaps analogous to Einstein's 1916 explanation for the excess precession of Mercury's perihelion.
Strong gravitational lensing: relativity in action
Authors: Wambsganss Joachim
Published: January 2010

Deflection of light by gravity was predicted by Einstein's Theory of General Relativity and observationally confirmed in 1919. In the following decades, various aspects of the gravitational lens effect were explored theoretically, among them measuring the Hubble constant from multiple images of a background source, making use of the magnifying effect as a gravitational telescope, or the possibility of a “relativistic eclipse” as a perfect test of GR. Only in 1979, gravitational lensing became an observational science when the first doubly imaged quasar was discovered. Today lensing is a booming part of astrophysics and cosmology. A whole suite of strong lensing phenomena have been investigated: multiple quasars, giant luminous arcs, Einstein rings, quasar microlensing, and galactic microlensing. The most recent lensing application is the detection of extrasolar planets. Lensing has contributed significant new results in areas as different as the cosmological distance scale, mass determination of galaxy clusters, physics of quasars, searches for dark matter in galaxy halos, structure of the Milky Way, stellar atmospheres and exoplanets. A guided tour through some of these applications will illustrate how gravitational lensing has established itself as a very useful universal astrophysical tool.
Very long baseline interferometry: accuracy limits and relativistic tests
Authors: Heinkelmann Robert , Schuh Harald
Published: January 2010

We present a review on relativistic effects and best estimates of the relativistic PPN parameter γ obtained by analysis of data from the International VLBI Service for Geodesy and Astrometry (IVS). Relativistic implications are also considered in view of the upcoming new generation VLBI System: VLBI2010.
Recent VLBA/VERA/IVS tests of general relativity
Authors: Fomalont Ed , Kopeikin Sergei , Jones Dayton , Honma Mareki , Titov Oleg
Published: January 2010

We report on recent VLBA/VERA/IVS observational tests of General Relativity. First, we will summarize the results from the 2005 VLBA experiment that determined gamma with an accuracy of 0.0003 by measuring the deflection of four compact radio sources by the solar gravitational field. We discuss the limits of precision that can be obtained with VLBA experiments in the future. We describe recent experiments using the three global arrays to measure the aberration of gravity when Jupiter and Saturn passed within a few arcmin of bright radio sources. These reductions are still in progress, but the anticipated positional accuracy of the VLBA experiment may be about 0.01 mas.
Gaia: Relativistic modelling and testing
Authors: Mignard F. , Klioner S. A.
Published: January 2010

Gaia is an ambitious space astrometry mission of ESA with a main objective to map the sky in astrometry and photometry down to a magnitude 20 by the end of the next decade. Given its extreme astrometric accuracy and the repeated observations over five years, the observation modelling is done in a fully relativistic framework and several tests of General Relativity or of its extensions can be carried out during the data processing. The paper presents an overview of the current activities in this area and of the expected performances.
Determining PPN γ with Gaia's astrometric core solution
Authors: Hobbs David , Holl Berry , Lindegren Lennart , Raison Frédéric , Klioner Sergei , Butkevich Alexey
Published: January 2010

The ESA space astrometry mission Gaia, due for launch in early 2012, will in addition to its huge output of fundamental astrometric and astrophysical data also provide stringent tests of general relativity. In this paper we present an updated analysis of Gaia's capacity to measure the PPN parameter γ as part of its core astrometric solution. The analysis is based on small-scale astrometric solutions taking into account the simultaneous determination of stellar astrometric parameters and the satellite attitude. In particular, the statistical correlation between PPN γ and the stellar parallaxes is considered. Extrapolating the results to a full-scale solution using some 100 million stars, we find that PPN γ could be obtained to about 10−6, which is significantly better than today's best estimate from the Cassini mission of 2 × 10−5.
Space clocks to test relativiy: ACES and SAGAS
Authors: Wolf Peter , Salomon Christophe , Reynaud Serge
Published: January 2010

Atomic clocks are an outstanding tool for the experimental verification of general relativity and more generally for fundamental astronomy (VLBI, pulsar timing, navigation, etc). Recent years have seen a rapid improvement in the performance of such clocks, promising new improved tests of relativity, in particular onboard terrestrial and interplanetary space missions. We present the scientific motivations of such tests taking the ACES Salomon et al. and SAGAS Wolf et al. (2009) projects as particular examples.
Testing the weak equivalence principle
Authors: Nobili Anna M. , Comandi Gian Luca , Pegna Raffaello , Bramanti Donato , Doravari Suresh , Maccarone Francesco , Lucchesi David M.
Published: January 2010

The discovery of Dark Energy and the fact that only about 5% of the mass of the universe can be explained on the basis of the current laws of physics have led to a serious impasse. Based on past history, physics might indeed be on the verge of major discoveries; but the challenge is enormous. The way to tackle it is twofold. On one side, scientists try to perform large scale direct observations and measurements – mostly from space. On the other, they multiply their efforts to put to the most stringent tests ever the physical theories underlying the current view of the physical world, from the very small to the very large. On the extremely small scale very exciting results are expected from one of the most impressive experiments in the history of mankind: the Large Hadron Collider. On the very large scale, the universe is dominated by gravity and the present impasse undoubtedly calls for more powerful tests of General Relativity – the best theory of gravity to date. Experiments testing the Weak Equivalence Principle, on which General Relativity ultimately lies, have the strongest probing power of them all; a breakthrough in sensitivity is possible with the “Galileo Galilei” (GG) satellite experiment to fly in low Earth orbit.
Comparison of the tropical radiative flux and cloud radiative effect profiles in a climate model with Clouds and the Earth's Radiant Energy System (CERES) data
Authors: Su Wenying , Bodas‐Salcedo Alejandro , Xu Kuan‐Man , Charlock Thomas P.
Published: January 2010

An insightful link of model performance to the physical assumptions in general circulation models (GCMs) can be explored if assessment of radiative fluxes and cloud radiative effects go beyond those at the top of the atmosphere (TOA). In this study, we compare the radiative flux profiles (at surface, 500 hPa, 200 hPa, 70 hPa, and TOA) and cloud effect profiles (500 hPa, 200 hPa, and TOA) from HadGAM1, using Surface and Atmospheric Radiation Budget (SARB) data from Clouds and the Earth's Radiant Energy System (CERES) on the TRMM satellite over the tropics (30°S–30°N). Comparison at TOA reveals that HadGAM1 agrees well with CERES for mean cloud height but lacks in cloudiness. Comparing to its predecessor, HadAM3, HadGAM1 agrees better with observations in TOA LW cloud effects, net cloud effects, and the ratio of SW to LW cloud effects. Extending the comparison to multiple levels, we gain additional insight into the vertical differences in clouds: for clouds at heights below 500 hPa, HadGAM1 and CERES are in good agreement in terms of cloudiness, but HadGAM1 underestimates the average cloud height; for clouds between 500 and 200 hPa, HadGAM1 underestimates the cloudiness but overestimates the average cloud height; for clouds at heights above 200 hPa, HadGAM1 produces more clouds than in CERES. Stratifying the cloud effects by dynamic regimes, we find that HadGAM1 underestimates cloudiness and overestimates averaged cloud height in the convective regimes, but the opposite is true in the strong subsidence regimes.
Malaria Diagnosis and the Plasmodium Life Cycle: the BFO Perspective
Authors: Ceusters Werner , Smith Barry
Published: January 2010

Definitive diagnosis of malaria requires the demonstration through laboratory tests of the presence within the patient of malaria parasites or their components. Since malaria parasites can be present even in the absence of malaria manifestations, and since symptoms of malaria can be manifested even in the absence of malaria parasites, malaria diagnosis raises important issues for the adequate understanding of disease, etiology and diagnosis. One approach to the resolution of these issues adopts a realist view, according to which the needed clarifications will be derived from a careful representation of the entities on the side of the patient which form the ultimate truthmakers for clinical statements. We here address a challenge to this realist approach relating to the diagnosis of malaria, and show how this challenge can be resolved by appeal to Basic Formal Ontology (BFO) and to the Ontology for General Medical Science (OGMS) constructed in its terms.
Emittance of a field emission electron source
Authors: Jensen K. L. , O’Shea P. G. , Feldman D. W. , Shaw J. L.
Published: January 2010

An analytical formula of the emittance of a field emitter is given. In contrast to thermal and photoemission, such a formula contains complexity due to the multidimensional nature of the source. A formulation of emittance is given for one- and three-dimensional (3D) field emitters. The 3D formulation makes use of the point charge model of a unit cell emitter coupled with a trajectory analysis to follow electrons to an evaluation plane where emittance is determined. The single tip theory is extended to an array and the resulting theory predicts the emittance of a Spindt-type square array of emitters 0.2cm on a side producing 2000A∕cm2 is 23mmmrad. Theory compares favorably with experimental measurements in the literature from ungated and gated sources. The impacts of several complications are estimated: the effects of a gate for modulating the emitter; the influence of space charge within the unit cell on the beam; and constraints imposed by modulation frequency, emitter dimensions, and rise/fall time requirements for turning a beam on and off, as determined by the array’s RLC characterization.
Characterization of ion emission of an extreme ultraviolet generating discharge produced Sn plasma
Authors: Gielissen K. , Sidelnikov Y. , Glushkov D. , Soer W. A. , Banine V. , Mullen J. J. A. M. v. d.
Published: January 2010

The ion emission of a Sn-based discharge produced extreme ultraviolet producing plasma is characterized with the combined use of different time-of-flight techniques. An electrostatic ion spectrometer is employed to measure the average charge distribution of the emitted Sn ions. A dedicated Faraday cup configuration is used to measure the total ion flux from the source for different discharge energies. High-energy Sn ions emitted by the plasma with energies up to 100 keV have been identified. The number of high-energy ions increases for higher electrical input energy into the plasma while the signal associated with the expanding plasma ions does not show such dependence. The ion energy distribution for a bulk of detected ions is calculated based on the Faraday cup measurements and compared with theoretical plasma expansion dynamics.
Elastic anomalies due to structural phase transitions in mechanoluminescent SrAl2O4:Eu
Authors: Carpenter M. A. , Howard C. J. , Andrew M. J. , McKnight R. E. A. , Liu Y. , Withers R. L.
Published: January 2010

Elastic and anelastic properties of a ceramic sample of elasticoluminescent SrAl2O4:Eu have been characterized as a function of temperature by resonant ultrasound spectroscopy. Both the bulk (K) and shear (G) moduli show changes attributable to the influence of the P6322→P63 (3A)→P21 sequence of structural phase transitions. Softening of K and stiffening of G at the P6322→P63 (3A) transition (Tc≈1135K) is consistent with weak strain/order parameter coupling and tricritical character. In marked contrast, the first order P63 (3A)→P21 transition near 930K is accompanied by stiffening such that G is ∼50% larger at room temperature than the value for a P6322 structure extrapolated directly from high temperatures and K is ∼15% larger. Softening of G at high temperatures is consistent with the existence of a soft acoustic mode. Both the P63 (3A) and P6322 phases show an increasing acoustic dissipation with increasing temperature and there is an additional peak in the dissipation behavior below ∼650K. Landau theory has been used to analyze the overall strain and elastic behavior of SrAl2O4:Eu. The stability of the P21 structure is considered in terms of coupling between order parameters with Γ6 and M2 symmetry, though it could also be stabilized by pairwise coupling of order parameters corresponding to irreps Γ4+M2, Γ4+M3, Γ6+M3, and M2+M3. Twin walls in this material should have interesting properties, which are quite distinct from those of the bulk material and could contribute differently to the elasticoluminescent properties.
A ridge tracking algorithm and error estimate for efficient computation of Lagrangian coherent structures
Authors: Lipinski Doug , Mohseni Kamran
Published: January 2010

A ridge tracking algorithm for the computation and extraction of Lagrangian coherent structures (LCS) is developed. This algorithm takes advantage of the spatial coherence of LCS by tracking the ridges which form LCS to avoid unnecessary computations away from the ridges. We also make use of the temporal coherence of LCS by approximating the time dependent motion of the LCS with passive tracer particles. To justify this approximation, we provide an estimate of the difference between the motion of the LCS and that of tracer particles which begin on the LCS. In addition to the speedup in computational time, the ridge tracking algorithm uses less memory and results in smaller output files than the standard LCS algorithm. Finally, we apply our ridge tracking algorithm to two test cases, an analytically defined double gyre as well as the more complicated example of the numerical simulation of a swimming jellyfish. In our test cases, we find up to a 35 times speedup when compared with the standard LCS algorithm.
Properties of aging FeCl2 clusters grown in supercritical water investigated by molecular dynamics simulations
Authors: Lümmen Norbert , Kvamme Bjørn
Published: January 2010

We have investigated the growth and properties of FeCl2 nanoparticles from supercritical water by molecular dynamics simulations. After particle growth had finished after less than 250 ps, selected properties of the aging clusters such as structure, shape, and amount of crystal water content were analyzed for up to 1.5 ns simulation time. Very quick growth and shape relaxation of the clusters are observed. The developments of cluster size, radius of gyration, and moments of inertia with time have been analyzed. The number of water molecules that are part of the clusters is found to increase almost linearly with cluster size. The shape relaxation of the clusters happens faster after cluster-cluster collisions and faster than the time needed for the clusters to reorganize their structure and attain a highly ordered ground state structure. The development of the cluster structure with time as analyzed by radial distribution functions shows hardly any changes over time, but shows significant variations with system temperature and system density.
Deduced property matrices of domain-engineered relaxor single crystals of [110]L×[001]T cut: Effects of domain wall contributions and domain-domain interactions
Authors: Shukla Rahul , Rajan Kalidindi Kotam , Shanthi M. , Jin Jing , Lim Leong-Chew , Gandhi Prasanna
Published: January 2010

Multidomain single crystal properties can be more accurately deduced from measured multidomain data instead of single-domain data, especially for the shear properties and clamped dielectric permittivities, which are strongly influenced by domain wall contributions and domain-domain interactions in the material. Using the above finding, the property matrices of Pb(Zn1/3Nb2/3)O3−(6–7)%PbTiO3, Pb(Zn1/3Nb2/3)O3−4.5%PbTiO3, and Pb(Mg1/3Nb2/3)O3−28%PbTiO3 single crystals of [110]L×[001]T (P) cut were deduced from the measured [100]L×[001]T (P) multidomain data. The results show that relaxor single crystals of [110]L×[001]T (P) cut have extremely high d312/s11E values, especially for Pb(Zn1/3Nb2/3)O3−(6–7)%PbTiO3 of which d312/s11E≈52 nN/V2, making such crystal cuts candidate materials for unimorph actuator applications.
Electronic Raman scattering in the laser-etched silicon nanostructures
Authors: Shukla A. K. , Kumar Rajesh , Kumar Vivek
Published: January 2010

Electronic Raman scattering is observed here in the silicon nanostructures. Observation of electronic Raman scattering in low dimensional silicon is possible due to coupling of Raman active phonons with photoexcited electrons found in the electronic states, which are available as a result of quantum confinement effect. Due to appreciable distribution of sizes in silicon nanostructures, a broad photoluminescence is observed revealing continuum of electronic states. Oscillator strength of electronic Raman scattering is found to increase with the increasing excitation laser power density.
Space charge effects in field emission: Three dimensional theory
Authors: Jensen Kevin L.
Published: January 2010

Field emitters rely on high gradients on microfabricated structures to enable substantial levels of emitted current, which can in turn act to reduce the field at the emission site of a single emitter. An account of that effect is obtained in the following steps: a model of the emitter geometry based on the point charge model that allows for the determination of the apex radius and field enhancement factor for arbitrarily sharp emitter structures is given, followed by an analytical formula for the calculation of total current from such a structure and then by a model of the effect of emitted current in suppressing the field at the emission site. Predictions of the impact of space charge on the emitted current are made and compared to findings of Barbour et al. [Phys. Rev. 92, 45 (1953)] for sharpened structures with varying work function. A discussion is given of the method to combine single tip three-dimensional results with a study of space charge on field emission in one dimension.
Space charge effects in field emission: One dimensional theory
Authors: Rokhlenko A. , Jensen K. L. , Lebowitz J. L.
Published: January 2010

The current associated with field emission is greatly dependent on the electric field at the emitting electrode. This field is a combination of the electric field in vacuum and the space charge created by the current. The latter becomes more important as the current density increases. Here, a study is performed using a modified classical one dimensional (1D) Child–Langmuir description that allows for exact solutions in order to characterize the contributions due to space charge. Methods to connect the 1D approach to an array of periodic three dimensional structures are considered.
Lobe transport analysis of the Kelvin–Stuart cat’s eyes driven flow
Authors: Rodrigue Stephen M. , Eschenazi Elia V.
Published: January 2010

Mixing and transport in the driven Kelvin–Stuart cat’s eyes dynamical system is studied using lobe transport theory and the topological approximation method (TAM). The application of the TAM also provides a global bifurcation analysis. Lobe areas are calculated using the Melnikov amplitude function, which has been derived for the Kelvin–Stuart system. Results indicate that regions, originally in the exterior above the vortex chain, can be transported to the exterior below the vortex chain (and vice versa) by passing through the interior, and that a region within the interior of a given vortex can be transported to the interior of a neighboring vortex, or the interior of a vortex several vortices distant from the given vortex. Cumulative transport is shown to decrease with increasing perturbation frequency for a fixed value of perturbation strength. Cumulative transport increases with increasing perturbation strength for a fixed value of the structure index L. Cumulative transport approaches a characteristic maximum value for each set of parameter values. Results demonstrate a linear dependence of the maximum cumulative transport upon a universal flux function of the form proposed by Rom-Kedar and Poje, suggesting a possible scaling in the transport dependent on the structure index L.
Magnetization reversal mechanism in La0.67Sr0.33MnO3 thin films on NdGaO3 substrates
Authors: Mathews M. , Houwman E. P. , Boschker H. , Rijnders G. , Blank D. H. A.
Published: January 2010

The field angle dependence of the coercive field of La0.67Sr0.33MnO3 thin films grown epitaxially on NdGaO3 substrates with different crystallographic orientations was determined. All films show uniaxial anisotropy. The angle dependence of the coercivity is best described by a two-phase model, explaining the strong increase in the coercive field for increasing field angles, away from the easy axis direction, as well as the sharp decrease for angles close to the hard direction. This implies that magnetization reversal starts with the depinning of domain walls, analogous to the Kondorsky model. With increasing field the reversal in the domains is not abrupt, but is determined by the gradual displacement of the domain walls. These results are of significance for understanding and possibly engineering of the switching behavior of magnetic tunnel junctions.
The effect of SiOx alignment layer thickness on the switching of SmC∗ bistable liquid crystal devices
Authors: Reznikov Mitya , Bos Philip J. , O’Callaghan Michael J.
Published: January 2010

SiO x alignment layers have been shown to allow defect-free SmC∗ devices with near optimum bistable orientation of the director. In this paper we investigate the effect of the thickness of this type of alignment layer on the required amplitude of an applied voltage pulse to cause bistable switching. The results of an experimental investigation and simple model are presented. We find that for thicker layers, the amplitude is controlled by the voltage drop across the alignment layers and by the effect of polar interactions between the liquid crystal (LC) and the alignment layers. For thin alignment layers the amplitude is weakly dependent on the details of the alignment layer, being more strongly influenced by the properties of the LC material.
Formation of conical silicon tips with nanoscale sharpness by localized laser irradiation
Authors: Moening Joseph P. , Georgiev Daniel G.
Published: January 2010

The formation of conical silicon tips with nanoscale sharpness as a result of single-pulse localized laser irradiation is presented in this work. A Q-switched neodymium doped yttrium aluminum garnet nanosecond-pulse laser, emitting at its fourth harmonic of 266 nm, and a mask projection technique were used to generate circular laser spots, several microns in diameter. The irradiation of silicon-on-insulator films was performed in ambient, vacuum, or argon atmospheres, with the resulting structures and underlying substrate examined via atomic force microscopy and scanning electron microscopy. The laser fluence range within which tip formation occurs is strongly dependent on the irradiated spot size. Within this range, the height of the resulting tip increases with the fluence level, while nearly preserving the aspect ratio. The formation mechanism of these structures is briefly discussed in view of these results and other, related published work.
Influence of the interfacial chemical environment on the luminescence of 3CSiC nanoparticles
Authors: Zakharko Yu. , Botsoa J. , Alekseev S. , Lysenko V. , Bluet J.-M. , Marty O. , Skryshevsky V. A. , Guillot G.
Published: January 2010

Surface chemistry of as-prepared 3CSiC nanoparticles obtained by electrochemical etching of bulk 3CSiC substrates was studied. Chemical environment was found to influence strongly the photoinduced electronic transitions in the 3CSiC nanoparticles. The influence of different interfacial chemical environments of the 3CSiC nanoparticles, such as surface chemistry, solvent nature, and surface charges on the photoinduced absorption and luminescence of the nanoparticles at room temperature, is described and discussed in detail. For example, oxidation induced passivation of the radiative band gap states allows visualization of the transitions between energy levels in the nanoparticles in which photogenerated charge carriers are quantumly confined. Electrostatic screening of the radiative band gap states by highly polar solvent media leads to a blueshift and a decrease in the width at half maximum of the photoluminescence spectra of the nanoparticles. As for the surface charges, they govern band bending slope and thus influence strongly the radiative transitions via energy states in the band gap.
Input impedance of a powerful single-core ferromagnetic inductively coupled plasma source
Authors: Bliokh Y. P. , Brodsky Yu. L. , Chashka Kh. B. , Felsteiner J. , Slutsker Ya. Z.
Published: January 2010

An experimental study of the recently developed version of the ferromagnetic inductively coupled plasma source has shown that under certain circumstances its input impedance becomes almost independent of the delivered rf driving power and (therefore) of the produced plasma density. This plasma source consists of a large ferromagnetic core, which is fully immersed in plasma. This core is surrounded by a primary winding and plasma appears due to gas discharge driven by an rf voltage applied to this primary winding. We have found values of parameters which determine the input impedance in such an “independent” regime and derived a quantitative theory which is in good agreement with the measured impedance values.
Synthesis of high-quality Al-doped ZnO nanoink
Authors: Thu Tran V. , Maenosono Shinya
Published: January 2010

Al-doped ZnO (AZO) nanoparticles (NPs) have been synthesized via the thermal decomposition of metal acetylacetonate precursors in a nonoxygen and nonpolar solvent. Long-chain alkyl amines have been utilized to terminate the growth of AZO NPs and to stabilize them. The NPs have been characterized by a number of techniques as monocrystalline, exhibiting a hexagonal (wurtzite) structure with sizes from 8 to 13 nm. The composition of Al in the resulting NP is related solely to the composition of the reaction mixture and the size is controllable with the temperature of the reaction. The AZO NP dispersion has been proven to be stable over a 24 h period by dynamic light scattering measurements. The influence of the synthetic conditions, such as temperature, reaction time and the Al doping content, on the properties of NPs have also been investigated. An optically transparent AZO thin film was fabricated using the AZO nanoink by spin casting followed by annealing. The resulting film resistivity was measured to be 5.0×10−3 Ω cm.
Development of a catheter for combined intravascular ultrasound and photoacoustic imaging
Authors: Karpiouk Andrei B. , Wang Bo , Emelianov Stanislav Y.
Published: January 2010

Atherosclerosis is characterized by formation and development of the plaques in the inner layer of the vessel wall. To detect and characterize atherosclerotic plaques, we previously introduced the combined intravascular ultrasound (IVUS) and intravascular photoacoustic (IVPA) imaging capable of assessing plaque morphology and composition. The utility of IVUS/IVPA imaging has been demonstrated by imaging tissue-mimicking phantoms and ex vivo arterial samples using laboratory prototype of the imaging system. However, the clinical realization of a IVUS/IVPA imaging requires an integrated intravascular imaging catheter. In this paper, two designs of IVUS/IVPA imaging catheters—side fire fiber-based and mirror-based catheters—are reported. A commercially available IVUS imaging catheter was utilized for both pulse-echo ultrasound imaging and detection of photoacoustic transients. Laser pulses were delivered by custom-designed fiber-based optical systems. The optical fiber and IVUS imaging catheter were combined into a single device. Both designs were tested and compared using point targets and tissue-mimicking phantoms. The results indicate applicability of the proposed catheters for clinical use.
Photodissociation dynamics of benzoic acid
Authors: Dyakov Yuri A. , Bagchi Arnab , Lee Yuan T. , Ni Chi-Kung
Published: January 2010

The photodissociation of benzoic acid at 193 and 248 nm was investigated using multimass ion imaging techniques. Three dissociation channels were observed at 193 nm: (1) C6H5COOH→C6H5+COOH, (2) C6H5COOH→C6H5CO+OH, and (3) C6H5COOH→C6H6+CO2. Only channels, (2) and (3), were observed at 248 nm. Comparisons of the ion intensities and photofragment translational energy distributions with the potential energies obtained from ab initio calculations and the branching ratios obtained from the Rice–Ramsperger–Kassel–Marcus theory suggest that the dissociation occurs on many electronic states.
Effects of applied electric field and hydrostatic pressure on donor impurity states in cylindrical GaN/AlN quantum dot
Authors: Xia Congxin , Zeng Zaiping , Wei Shuyi
Published: January 2010

Based on the effective-mass approximation and variational procedure, the donor impurity states in the cylindrical zinc-blende GaN/AlN quantum dot (QD) are investigated, considering the influence of the applied electric field and hydrostatic pressure along the growth direction. Numerical results show that the donor binding energy is highly dependent on the impurity positions, quantum size, applied electric field, and hydrostatic pressure. It is found that the hydrostatic pressure has a remarkable influence on the donor binding energy of the hydrogenic impurity in the QD with a small size and a strong applied electric field. However, the applied electric field affects obviously the donor binding energy in the QD with a large QD size and a small hydrostatic pressure. In addition, the competition effects between the applied electric field and quantum confinement on the donor impurity states in the QD have also been investigated in detail, which is useful to understand impurity states in semiconducting nanostructures.
Direct mapping between exchange potentials of Hartree–Fock and Kohn–Sham schemes as origin of orbital proximity
Authors: Cinal M.
Published: January 2010

It is found that for closed-l-shell atoms, the exact local exchange potential vx(r) calculated in the exchange-only Kohn–Sham (KS) scheme of the density functional theory (DFT) is very well represented within the region of every atomic shell by each of the suitably shifted potentials obtained with the nonlocal Fock exchange operator for the individual Hartree–Fock (HF) orbitals belonging to this shell. This newly revealed property is not related to the well-known steplike shell structure in the response part of vx(r), but it results from specific relations satisfied by the HF orbital exchange potentials. These relations explain the outstanding proximity of the occupied HF and exchange-only KS orbitals as well as the high quality of the Krieger–Li–Iafrate and localized HF (or, equivalently, common-energy-denominator) approximations to the DFT exchange potential vx(r). Another highly accurate representation of vx(r) is given by the continuous piecewise function built of shell-specific exchange potentials, each defined as the weighted average of the shifted orbital exchange potentials corresponding to a given shell. The constant shifts added to the HF orbital exchange potentials, to map them onto vx(r), are nearly equal to the differences between the energies of the corresponding KS and HF orbitals. It is discussed why these differences are positive and grow when the respective orbital energies become lower for inner orbitals.
On space and time correlations of isotropic and rotating turbulence
Authors: Favier B. , Godeferd F. S. , Cambon C.
Published: January 2010

Two different approaches are used for evaluating two-time correlations of Fourier velocity modes in isotropic and in rotating homogeneous incompressible turbulence. A synthetic model is proposed and compared with the results of direct numerical simulations. This kinematic model presents the advantage to incorporate different sources of unsteadiness from arbitrary time scales to linear dynamics of rotating flows. The two main time scales characterizing the various processes involved in the dynamics of isotropic turbulence can be included: the sweeping effect, in which small scales of the flow are advected by the large scale motion, and the straining hypothesis—also called Kolmogorov or eddy turnover time scale. In the rotating case, the dispersion relation of inertial waves can also be included. Using Lighthill’s theory, the effect of these different time scales on the sound emitted by such a model is also examined and compared with direct numerical simulations.