bluuebunny/crossref_metadata_2025 huggingface dataset:
The Current Trends in SBS and phase conjugation
Authors: Omatsu T. , Kong H.J. , Park S. , Cha S. , Yoshida H. , Tsubakimoto K. , Fujita H. , Miyanaga N. , Nakatsuka M. , Wang Y. , Lu Z. , Zheng Z. , Zhang Y. , Kalal M. , Slezak O. , Ashihara M. , Yoshino T. , Hayashi K. , Tokizane Y. , Okida M. , Miyamoto K. , Toyoda K. , Grabar A.A. , Kabir Md. M. , Oishi Y. , Suzuki H. , Kannari F. , Schaefer C. , Pandiri K.R. , Katsuragawa M. , Wang Y.L. , Lu Z.W. , Wang S.Y. , Zheng Z.X. , He W.M. , Lin D.Y. , Hasi W.L.J. , Guo X.Y. , Lu H.H. , Fu M.L. , Gong S. , Geng X.Z. , Sharma R.P. , Sharma P. , Rajput S. , Bhardwaj A.K. , Zhu C.Y. , Gao W.
Published: March 2012

The current trends in stimulated Brillouin scattering and optical phase conjugation are overviewed. This report is formed by the selected papers presented in the “Fifth International Workshop on stimulated Brillouin scattering and phase conjugation 2010” in Japan. The nonlinear properties of phase conjugation based on stimulated Brillouin scattering and photo-refraction can compensate phase distortions in the high power laser systems, and they will also open up potentially novel laser technologies, e.g., phase stabilization, beam combination, pulse compression, ultrafast pulse shaping, and arbitrary waveform generation.
A System for Tracking an Autonomously Controlled Canine
Authors: Miller Jeff , Flowers George , Bevly David
Published: March 2012

This paper presents an approach for outdoor navigation of an autonomously guided canine using an embedded command module with vibration and tone generation capabilities and an embedded control suite comprised of a microprocessor, wireless radio, GPS receiver, and an Attitude and Heading Reference System. In order to determine the canine's motions, which inherently contain non-conventional noise characteristics, the sensor measurements were integrated using a specialized Extended Kalman Filter (EKF), equipped with a Fuzzy Logic controller for adaptive tuning of the Process Noise Covariance Matrix. This allowed for rejection of un-modelled canine motion characteristics which tend to corrupt accelerometer bias tracking in a standard EKF. The EKF solution provided an optimized estimate of the canine position and velocity and also proved to be effective in tracking the canine's position (within 7·5 m) and velocity (within 1·2 m/s) during simulated 10 second GPS outages.
Bound water freezing in AntarcticUmbilicaria aprinafrom Schirmacher Oasis
Authors: Harańczyk H. , Nowak P. , Bacior M. , Lisowska M. , Marzec M. , Florek M. , Olech M.A.
Published: March 2012

The effect of low temperature onUmbilicaria aprinacollected from Schirmacher Oasis, East Antarctica, was determined over a wide range of hydration using proton free induction decays, proton nuclear magnetic resonance (NMR) spectra and differential scanning calorimetry methods. The proton NMR line is a superposition of the broad component from the solid matrix of the thallus and a narrower component from the averaged bound water pool. Proton free induction decays may be resolved into three components: a solid component well described by the Abragam function and two exponentially decaying components from water loosely bound and water tightly bound in the thallus. With decreased temperature the loosely bound water pool (freezing water) is transferred to the tightly bound water pool (non-freezing water), and vanishes below -40°C. Bound water freezing and melting temperatures decrease with the decrease of hydration level, suggesting that heterogeneous ice nucleation is responsible for water freezing. The onset of bound water freezing temperature isc.10°C lower than the melting temperature. TheU. aprinathalli do not reveal the ability to stimulated ice nucleation at higher temperature. Freeze-thaw cycles showed that forn> 5 cycles no substantial change occurs in the difference between melting and freezing temperatures.
Hg distribution and speciation in Antarctic soils of the Fildes and Ardley peninsulas, King George Island
Authors: De Andrade Renato Pereira , Michel Roberto Ferreira Machado , Schaefer Carlos Ernerto Gonçalves Reynaud , Simas Felipe Nogueira Bello , Windmöller Cláudia Carvalhinho
Published: March 2012

Data on the content and speciation of mercury (Hg) in the soils of Antarctica are scarce and vary greatly between the regions studied, but overall Hg concentrations found were generally very low. We investigated the Hg quantity and speciation by solid-phase Hg pyrolysis and chemical fractionation in selected maritime Antarctic soils, comparing ornithogenic and non-ornithogenic areas of the Fildes and Ardley peninsulas of King George Island. The total Hg contents ranged from 4.3–256 ng g-1, and values for ornithogenic soils were the highest recorded for Antarctic soils. A close correlation between Hg and organic matter was observed in the ornithogenic soils, with levels decreasing with depth. In the non-ornithogenic soils, a correlation between Hg content and soil depth was also observed, but the values were found to increase with depth. Thermograms showed that all Hg was in the 2+ oxidation state and was predominantly linked to organic matter, corroborating the chemical fractionation results for the ornithogenic soils. These results show the need for further refined studies about the interactions of Hg with organic matter in order to better understand the biogeochemistry of this metal in the Antarctic environment.
Gender, prescriptivism, and language change: Morphological variation in Hebrew animate reference
Authors: Levon Erez
Published: March 2012

Beliefs about a language rarely correspond to how it is used. This is especially true for Hebrew, a language that has been subject to continued ideological “preservation” efforts ever since its (re)vernacularization in the early 20th century. Recently, attention has turned to the maintenance of Hebrew gender morphology, which is perceived in both scholarly and popular opinion as threatened by a process of leveling to gender syncretized forms across a range of word classes and inflectional paradigms. In this article, I investigate the extent to which sociolinguistic evidence supports this perception in cases of animate reference. I argue that while the claim of widespread gender neutralization of these forms is descriptively valid, its characterization as a change-in-progress is inaccurate. Rather, I suggest that Hebrew is already fully syncretized for gender in certain relevant morphological contexts and that the perception of an ongoing process of change reflects a prescriptive belief about how Hebrew should be, not how it actually is.
The Rise and Fall of Enforcement Institutions: An Example of Religion and Secularism
Authors: Ciaian Pavel , Pokrivčák Ján , Kancs D'Artis
Published: March 2012

Societies in Western civilisation enforce their rules through formal secular institutions (SES), whereas less developed civilisations often rely on informal, often religious, institutions (RES). The present paper attempts to explain the determinants of societies’ choice between different enforcement systems, and their implications for society development using an example of two different enforcement models: one informal (RES) and one formal (SES). We find that, because the RES is based on beliefs, its efficiency depends heavily on its credibility, making it hardly flexible and highly susceptible to conflicts in dynamic environments. In contrast, because under the SES societal rules are enforced through a formal legal enforcement sector, the SES is more flexible, although also more costly than the RES. The empirical evidence strongly supports our findings that wealthy, dynamic and fast growing economies typically choose the SES for enforcing societal norms and rules.
Reform of the EU Cohesion Policy
Authors: König Petr
Published: March 2012

The paper deals with the definition of eligibility criteria for regions and states to draw resources within the Convergence objective and the Regional Competitiveness and Employment objective of the EU Cohesion Policy funds. It proposes which regions and countries should be regarded as poor ones and to what extent they should be eligible for financing. The paper proposes that support would only go to regions in Member States poorer than the EU average and, within these countries, support would only be available to NUTS 2 regions poorer than the EU average. In addition, the difference between the region's GDP per capita in PPS and the EU average would be reflected by setting a ceiling for maximum admissible allocation to eligible regions between 1 and 4% of the region's GDP in EUR. The paper also proposes to abolish the Cohesion Fund. Finally, eligible regions and countries are identified based on a numerical model, where support going to regions with lower-than-average GDPpc PPS belonging to countries with lower-than-average GNIpc PPS is also calculated.
Voting after Watching: The Strategic Role of Election Polls
Authors: Gherghina Sergiu , Chiru Mihail
Published: March 2012

The November 2009 Romanian presidential elections illustrate the process through which media exposure to exit polls during the election day allows strategic voting in the least expected situations (i.e. in the first round of a two-ballot setting). Organized in a two-round system in which the first two competitors qualify for the second round, these elections display one unsolved dilemma. The difference registered in elections between the two challengers is twice as large as the average support in the pre-election polls (a comparable difference was never registered in post-communist Romania). Our quantitative analysis uses election results from the past two decades and aggregated poll data from 2009 and reveals that a large share of the Romanian electorate avoids wasting votes and casts them for candidates with real winning chances. This article argues that polls presented to the voters, by the media during the elections, made the difference. They were used as electoral strategies to trigger strategic voting and thus promote specific candidates.
The double burden of malnutrition and cardiometabolic risk widens the gender and socio-economic health gap: a study among adults in Burkina Faso (West Africa)
Authors: Zeba Augustin N , Delisle Hélène F , Renier Genevieve , Savadogo Boubacar , Baya Banza
Published: March 2012

Objective

To document the double burden of malnutrition and cardiometabolic risk factors (CMRF) in adults and its occurrence according to different sociodemographic parameters.

Design

Population-based cross-sectional observational study. We first randomly selected 330 households stratified by tertile of the income levels proxy as low, middle and high income.

Setting

Northern district of Ouagadougou, the capital city of Burkina Faso.

Subjects

In each income stratum, 110 individuals aged 25–60 years and who had lived permanently in Ouagadougou for at least 6 months were randomly selected, followed with collection of anthropometric, socio-economic and clinical data, and blood samples.

Results

The overall obesity/overweight prevalence was 24·2 % and it was twice as high in women as in men (34·1 %v. 15·5 %,P< 0·001). Hypertension, hyperglycaemia and low HDL cholesterol prevalence was 21·9 %, 22·3 % and 30·0 %, respectively, without gender difference. The prevalence of the metabolic syndrome was 10·3 %. Iron depletion and vitamin A deficiency affected 15·7 % and 25·7 % of participants, respectively, with higher rates in women. Coexistence of at least one nutritional deficiency and one CMRF was observed in 23·5 % of participants, and this ‘double burden’ was significantly higher in women than in men (30·4 %v. 16·1 %,P= 0·008) and in the low income group.

Conclusions

CMRF are becoming a leading nutritional problem in adults of Ouagadougou, while nutritional deficiencies persist. The double nutritional burden exacerbates health inequities and calls for action addressing both malnutrition and nutrition-related chronic diseases.
How well do Australian shoppers understand energy terms on food labels?
Authors: Watson Wendy L , Chapman Kathy , King Lesley , Kelly Bridget , Hughes Clare , Yu Louie Jimmy Chun , Crawford Jennifer , Gill Timothy P
Published: March 2012

Objective

To investigate nutrition literacy among adult grocery buyers regarding energy-related labelling terms on food packaging.

Design

Qualitative interviews and quantitative surveys to determine shoppers’ understanding of energy terms (‘energy’, ‘calories’ and ‘kilojoules’) and how energy terms affect perceptions of healthiness and intentions to purchase breakfast cereals, muesli bars and frozen meals.

Setting

Individual in-depth interviews and surveys in two metropolitan supermarkets, Sydney, Australia.

Subjects

Australian adults (interview n 40, survey n 405) aged 18–79 years.

Results

The relationship between energy and perceived healthiness of food varied by product type: higher energy breakfast cereals were perceived to be healthier, while lower energy frozen meals were seen as healthier choices. Likewise, intentions to purchase the higher energy product varied according to product type. The primary reason stated for purchasing higher energy products was for sustained energy. Participants from households of lower socio-economic status were significantly more likely to perceive higher energy products as healthier. From the qualitative interviews, participants expressed uncertainty about their understanding of kilojoules, while only 40 % of participants in intercept surveys correctly answered that kilojoules and calories measured the same thing.

Conclusions

Australian consumers have a poor understanding of energy and kilojoules and tend to perceive higher energy products as healthier and providing sustained energy. This has implications regarding the usefulness of industry front-of-pack labelling initiatives and quick service restaurant menu labelling that provides information on energy content only. Comprehensive and widely communicated education campaigns will be essential to guide consumers towards healthier choices.
History Repeating . . . Disaster-Related Intercountry Adoption and the Psychosocial Care of Children
Authors: Fronek Patricia , Cuthbert Denise
Published: March 2012

Disasters are prevalent with devastating effects on vulnerable populations that include the elderly, disabled, women and children. Historical responses to vulnerable children and families post-disaster raise questions concerning further harms to children rescued by adoption in the aftermath of devastation. This article offers critical and historical perspectives on child removal for adoption in the context of disaster and the psychosocial care of children affected by disaster. It brings into question whether removal, especially permanent removal for adoption, is in their interests. This article concludes that efforts are needed by the international community to ensure that past abuses do not recur.
Der „Affective Style Questionnaire (ASQ)”: Deutsche Adaption und Validitäten
Authors: Graser Johannes , Bohn Christiane , Kelava Augustin , Schreiber Franziska , Hofmann Stefan G. , Stangier Ulrich
Published: March 2012

Zusammenfassung. Der Affective Style Questionnaire (ASQ) wurde aus dem Englischen übersetzt und an einer studentischen Stichprobe (N = 640) validiert. Der ASQ ist ein Selbstbeurteilungsinstrument bestehend aus 20 Items, in dem drei allgemeine Emotionsregulationsstile erfasst werden: Unterdrücken, Anpassen/Neubewerten und Akzeptieren. Die faktorielle Struktur wurde mithilfe des ESEM-Verfahrens (Exploratory Structural Equation Modeling) überprüft. Die Ergebnisse konnten die Faktorenstruktur der englischen Vorlage bestätigen. Die Testgütekriterien, die Konstruktvalidität und demographische Einflüsse wurden untersucht. Die internen Konsistenzen erwiesen sich als zufriedenstellend (Unterdrücken-Skala: α = .84; Anpassen-Skala: α = .75; Akzeptieren-Skala: α = .72), was ebenfalls sehr nahe an den Werten der Originalstudie liegt. Die Subskalen wiesen hypothesenkonforme Zusammenhänge zu bestehenden Verfahren aus dem Forschungsbereich „Emotionsregulation” auf. Der deutschsprachige ASQ ist ein ökonomisches Instrument in einem Bereich, in dem es erst sehr wenige validierte Verfahren gibt. Kein bestehendes Verfahren erfasst die drei genannten Stile in zufriedenstellender Weise gemeinsam. Mögliche Einsatzbereiche sind in der gesunden Allgemeinbevölkerung und nach weiterer Validierung auch in klinischen Populationen anzusehen.
The 2011 southeast Queensland extreme summer rainfall: A confirmation of a negative Pacific Decadal Oscillation phase?
Authors: Cai Wenju , van Rensch Peter
Published: March 2012

The devastating southeast Queensland (SEQ) flood and the associated extreme rainfall in January 2011 were accompanied by an extraordinarily strong La Niña. The regional summer rainfall is affected by the El Niño‐Southern Oscillation (ENSO) cycle, but modulated by the Pacific Decadal Oscillation (PDO) or the Interdecadal Pacific Oscillation (IPO). What does the recent flood tell about the status of the PDO‐IPO? Using three lines of supporting evidence it is proposed that the SEQ 2011 austral summer rain constitutes a confirmation of a transition to a negative phase of the PDO‐IPO. Firstly, the 2011 summer saw large SEQ rainfall and SOI values that historically occur only in a negative PDO‐IPO phase; secondly, there was an associated re‐establishment of an ENSO‐SEQ rainfall teleconnection; and finally, the decadal‐circulation state, particularly the tropical convection, has developed toward a state similar to that during other negative PDO‐IPO periods. The results imply an increased chance of high summer rainfall events over the region during La Niña in the upcoming decade or so.
Why does the subsolar magnetopause move sunward for radial interplanetary magnetic field?
Authors: Samsonov A. A. , Němeček Z. , Šafránková J. , Jelínek K.
Published: March 2012

This paper analyzes the distribution of different pressure components (dynamic, thermal, magnetic) in the magnetosheath along the Sun‐Earth line for northward and radial interplanetary magnetic field (IMF) orientations with motivation to explain an unusual location and shape of the magnetopause often observed during the intervals of the radial IMF. The analysis employs isotropic and anisotropic MHD models, and their results are compared with the statistical processing of THEMIS observations. We have found that (1) the temperature anisotropy in the magnetosheath controls the pressure distribution near the magnetopause, and (2) the total pressure exerted on the subsolar magnetopause depends on the IMF orientation being significantly lower than the solar wind dynamic pressure for the radial IMF. The results of both MHD simulations and statistical investigations are quantitatively consistent with already published observations of the average magnetopause location as a function of the IMF orientation.
Influence of anomalous dry conditions on aerosols over India: Transport, distribution and properties
Authors: Kaskaoutis D. G. , Gautam R. , Singh R. P. , Houssos E. E. , Goto D. , Singh S. , Bartzokas A. , Kosmopoulos P. G. , Sharma M. , Hsu N. C. , Holben B. N. , Takemura T.
Published: March 2012

A synergy of satellite and ground‐based radiometric observations, along with chemical transport modeling, was used for the assessment of the influence of drought monsoon conditions of 2002 and prolonged dry pre‐monsoon period of 2003 on aerosol properties over south Asia, with emphasis over northern India. Reanalysis data are also examined for studying the dry anomalous period from the climatological mean, that show prevalence of westerlies under anticyclonic circulation and subsidence favoring the accumulation of aerosols. TRMM observations over south Asia indicate significant rainfall deficit over northwestern India in July 2002 and May–June 2003. Subsequently, the anomalous and prolonged dry conditions favored heavy aerosol buildup as indicated by strong positive anomalies (20–80%) of MODIS aerosol optical depth (AOD) as well as significant increase in TOMS aerosol index (AI) during July 2002 and May–June 2003 compared to the long‐term monthly means. The largest increase in aerosol loading is observed over northern India, encompassing the Indo‐Gangetic Plains (IGP) that is in the downwind region of dust outflow from the Thar Desert and long‐range transport from Arabia and Middle East. Ground‐based sunphotometer observations at Delhi and Kanpur also show enhanced presence of desert‐dust aerosols during July 2002 and May–June 2003, characterized by large AOD and significantly low Angstrom Exponent. In addition, modifications in columnar aerosol size distribution toward larger coarse‐mode fraction and higher single scattering albedo at longer wavelengths were observed, thus supporting the observation of enhanced dust influx. SPRINTARS model simulations also show the enhanced dust loading over northern India during the studied months, which is in general agreement with the satellite and ground‐based observations.
Effects of river regulation on aeolian landscapes, Colorado River, southwestern USA
Authors: Draut Amy E.
Published: March 2012

Connectivity between fluvial and aeolian sedimentary systems plays an important role in the physical and biological environment of dryland regions. This study examines the coupling between fluvial sand deposits and aeolian dune fields in bedrock canyons of the arid to semiarid Colorado River corridor, southwestern USA. By quantifying significant differences between aeolian landscapes with and without modern fluvial sediment sources, this work demonstrates for the first time that the flow‐ and sediment‐limiting effects of dam operations affect sedimentary processes and ecosystems in aeolian landscapes above the fluvial high water line. Dune fields decoupled from fluvial sand supply have more ground cover (biologic crust and vegetation) and less aeolian sand transport than do dune fields that remain coupled to modern fluvial sand supply. The proportion of active aeolian sand area also is substantially lower in a heavily regulated river reach (Marble–Grand Canyon, Arizona) than in a much less regulated reach with otherwise similar environmental conditions (Cataract Canyon, Utah). The interconnections shown here among river flow and sediment, aeolian sand transport, and biologic communities in aeolian dunes demonstrate a newly recognized means by which anthropogenic influence alters dryland environments. Because fluvial–aeolian coupling is common globally, it is likely that similar sediment‐transport connectivity and interaction with upland ecosystems are important in other dryland regions to a greater degree than has been recognized previously.
Water temperature modeling in the Lower Ebro River (Spain): Heat fluxes, equilibrium temperature, and magnitude of alteration caused by reservoirs and thermal effluent
Authors: Prats Jordi , Val Rafael , Dolz Josep , Armengol Joan
Published: March 2012

The lower Ebro River (Spain) is subject to the thermal and hydrological alterations caused by the system of reservoirs of Mequinenza, Riba‐roja, and Flix and to the thermal effluent of the nuclear power plant of Ascó, located 5 km downstream from the three reservoirs. In this paper, a modeling approach is used to determine the equilibrium temperature and recuperation distance at the study reach for different seasons and hydrological years. The intensity of the alteration caused by the reservoirs and nuclear power plant effluent is studied in reference to the equilibrium temperature and discharge rate. Mean daily water temperature downstream from the reservoirs is higher than mean daily equilibrium temperature in the fall and is lower during the rest of the year. Changes in the heat fluxes induced by thermal alteration are also addressed, showing important variations in evaporation and conduction to the atmosphere.
Theory of the Origin, Evolution, and Nature of Life
Authors: Andrulis Erik
Published: March 2012

Life is an inordinately complex unsolved puzzle. Despite significant theoretical progress, experimental anomalies, paradoxes, and enigmas have revealed paradigmatic limitations. Thus, the advancement of scientific understanding requires new models that resolve fundamental problems. Here, I present a theoretical framework that economically fits evidence accumulated from examinations of life. This theory is based upon a straightforward and non-mathematical core model and proposes unique yet empirically consistent explanations for major phenomena including, but not limited to quantum gravity, phase transitions of water, why living systems are predominantly CHNOPS (carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur), homochirality of sugars and amino acids, homeoviscous adaptation, the triplet code, and DNA mutations. The theoretical framework proves the unity of macrocosmic and microcosmic realms, validates predicted laws of nature, and solves the puzzle of the origin and evolution of cellular life in the universe.
High-voltage, high-resolution electron microscopes
Authors: Lubkin Gloria B.
Published: March 2012

Several groups are building electron microscopes with high voltage or high resolution or both that should distinctly extend their capabilities, particularly for observations in biology. One such group, which we recently visited at the Cavendish Laboratory, University of Cambridge, is building a 600-kV conventional microscope that is expected to have a resolving power approaching 1 Å, according to V. E. Cosslett and W. C. Nixon, who head the Cavendish team. Among those hoping to extend the frontiers of electron microscopy, besides the Cavendish, are groups at Oak Ridge National Laboratory, Cornell University, the University of Kyoto, the University of Nagoya, the University of Chicago and Arizona State University.
Experimental measurements of spatial plasma potentials and electron energy distributions in inductively coupled plasma under weakly collisional and nonlocal electron kinetic regimes
Authors: Lee Hyo-Chang , Chung Chin-Wook
Published: March 2012

Spatial profiles of the plasma potential and electron energy distribution function (EEDF) were measured in inductively coupled plasma (ICP) under weakly collisional and electron nonlocal kinetic regimes. The measured EEDF at the discharge center was a bi-Maxwellain distribution with low (T1) and high (T2) electron temperature groups, while the EEDF at the radial boundary was closely Maxwellian distribution due to cutting of the low energy electrons by relatively large ambipolar potential in this discharge regime. The ambipolar potential in the entire radial region was in the scale of Teff − 1.5 Teff, where Teff is the effective electron temperature. At the boundary region with the ion mean free path scale, the ambipolar potential increased abruptly and was about Teff,edge/2, where the Teff,edge is the effective electron temperature at the boundary, which corresponds to the presheath scale. These results of the ICP, which are contrary to the ambipolar potential of capacitively coupled plasma in a nearly free-fall regime, are caused by relatively high T1 and a small portion of low energy electron group density to total electron density in the ICP under the weakly collisional and nonlocal electron kinetic regimes.
Equation of state and jamming density for equivalent bi- and polydisperse, smooth, hard sphere systems
Authors: Ogarko V. , Luding S.
Published: March 2012

We study bi- and polydisperse mixtures of hard sphere fluids with extreme size ratios up to 100. Simulation results are compared with previously found analytical equations of state by looking at the compressibility factor, Z, and agreement is found with much better than 1% deviation in the fluid regime. A slightly improved empirical correction to Z is proposed. When the density is further increased, excluded volume becomes important, but there is still a close relationship between many-component mixtures and their binary, two-component equivalents (which are defined on basis of the first three moments of the size distribution). Furthermore, we determine the size ratios for which the liquid-solid transition exhibits crystalline, amorphous or mixed system structure. Near the jamming density, Z is independent of the size distribution and follows a −1 power law as function of the difference from the jamming density (Z → ∞). In this limit, Z depends only on one free parameter, the jamming density itself, as reported for several different size distributions with a wide range of widths.
The limits and challenges of error field correction for ITER
Authors: Buttery R. J. , Boozer A. H. , Liu Y. Q. , Park J.-K. , Ferraro N. M. , Amoskov V. , Gribov Y. , La Haye R. J. , Lamzin E. , Menard J. E. , Schaffer M. J. , Strait E. J. ,   DIII-D Team
Published: March 2012

Significant progress has been made in interpreting the effects of non-axisymmetric “error” fields on a plasma through ideal MHD stability and a dominant “least stable” ideal mode through which the fields couple to the tearing resonant surface. However, in contrast to expectations from such theories, experiments have found limited success in correcting error fields, with single correction coil arrays giving benefits of between 0% and ∼50% correction (in terms of improvement to a low density locked mode limit), dependent on the structure of the error and correcting fields. With additional coils up to ∼70% is possible. It was unclear whether this represented an intrinsic stability or control limit, or higher order toroidal or poloidal harmonic effects. Thus, studies on the DIII-D tokamak explored correction of a proxy error field, using two differently structured coil arrays. This enabled the principles of error correction to be tested at high amplitudes and operational densities, with known pure n=1 fields. Results showed substantial residual effects from the corrected n=1 field, with improvements of only ∼50% in the low density locked mode limit. This suggests that n=1 error fields must couple to more than one surface in the plasma, and this is conjectured to be through more than one ideal mode, thereby requiring precise correction. For ITER, updated predictions of field error have been obtained and compared with revised scalings for tearing mode thresholds, indicating 50% or better error field correction will be needed. This will likely require more than one well coupled correction coil array and sets a challenge for theory to model the behavior, in order to clarify the plasma response and braking mechanisms, and so the effectiveness of ITER's correction coils and the possible need for support from its edge localized mode control coils.
Measurements of the deuterium ion toroidal rotation in the DIII-D tokamak and comparison to neoclassical theory
Authors: Grierson B. A. , Burrell K. H. , Heidbrink W. W. , Lanctot M. J. , Pablant N. A. , Solomon W. M.
Published: March 2012

Bulk ion toroidal rotation plays a critical role in controlling microturbulence and MHD stability as well as yielding important insight into angular momentum transport and the investigation of intrinsic rotation. So far, our understanding of bulk plasma flow in hydrogenic plasmas has been inferred from impurity ion velocity measurements and neoclassical theoretical calculations. However, the validity of these inferences has not been tested rigorously through direct measurement of the main-ion rotation in deuterium plasmas, particularly in regions of the plasma with steep pressure gradients where very large differences can be expected between bulk ion and impurity rotation. New advances in the analysis of wavelength-resolved Dα emission on the DIII-D tokamak [J. L. Luxon et al., Fusion Sci. Technol. 48, 807 (2002)] have enabled accurate measurements of the main-ion (deuteron) temperature and toroidal rotation. The Dα emission spectrum is accurately fit using a model that incorporates thermal deuterium charge exchange, beam emission, and fast ion Dα (FIDA) emission spectra. Simultaneous spectral measurements of counter current injected and co current injected neutral beams permit a direct determination of the deuterium toroidal velocity. Time-dependent collisional radiative modeling of the photoemission process is in quantitative agreement with measured spectral characteristics. L-mode discharges with low beam ion densities and broad thermal pressure profiles exhibit deuteron temperature and toroidal rotation velocities similar to carbon. However, intrinsic rotation H-mode conditions and plasmas with internal transport barriers exhibit differences between core deuteron and carbon rotation which are inconsistent with the sign and magnitude of the neoclassical predictions.
Precise control of single- and bi-layer graphene growths on epitaxial Ni(111) thin film
Authors: Entani Shiro , Matsumoto Yoshihiro , Ohtomo Manabu , Avramov Pavel V. , Naramoto Hiroshi , Sakai Seiji
Published: March 2012

In situ analysis was performed on the graphene growth in ultrahigh vacuum chemical vapor deposition by exposing the epitaxial Ni(111) thin film to benzene vapor at 873 K. It is shown that the highly uniform single- and bi-layer graphenes can be synthesized by the control of benzene exposure in the range of 10–105 langmuirs, reflecting a change in the graphene growth-rate by three orders of magnitude in between the first and second layer. Electron energy loss spectroscopy measurements of single- and bi-layer graphenes indicates that the interface interaction between bi-layer graphene and Ni(111) is weakened in comparison with that between single-layer graphene and Ni(111). It is also clarified from the micro-Raman analysis that the structural and electrical uniformities of the graphene film transformed on a SiO2 substrate are improved remarkably under the specific exposure conditions at which the growths of single- and bi-layer graphenes are completed.
The velocity campaign for ignition on NIF
Authors: Callahan D. A. , Meezan N. B. , Glenzer S. H. , MacKinnon A. J. , Benedetti L. R. , Bradley D. K. , Celeste J. R. , Celliers P. M. , Dixit S. N. , Döppner T. , Dzentitis E. G. , Glenn S. , Haan S. W. , Haynam C. A. , Hicks D. G. , Hinkel D. E. , Jones O. S. , Landen O. L. , London R. A. , MacPhee A. G. , Michel P. A. , Moody J. D. , Ralph J. E. , Robey H. F. , Rosen M. D. , Schneider M. B. , Strozzi D. J. , Suter L. J. , Town R. P. J. , Widmann K. , Williams E. A. , Edwards M. J. , MacGowan B. J. , Lindl J. D. , Atherton L. J. , Kyrala G. A. , Kline J. L. , Olson R. E. , Edgell D. , Regan S. P. , Nikroo A. , Wilkins H. , Kilkenny J. D. , Moore A. S.
Published: March 2012

Achieving inertial confinement fusion ignition requires a symmetric, high velocity implosion. Experiments show that we can reach 95 ± 5% of the required velocity by using a 420 TW, 1.6 MJ laser pulse. In addition, experiments with a depleted uranium hohlraum show an increase in capsule performance which suggests an additional 18 ± 5 μm/ns of velocity with uranium hohlraums over gold hohlraums. Combining these two would give 99 ± 5% of the ignition velocity. Experiments show that we have the ability to tune symmetry using crossbeam transfer. We can control the second Legendre mode (P2) by changing the wavelength separation between the inner and outer cones of laser beams. We can control the azimuthal m = 4 asymmetry by changing the wavelength separation between the 23.5 and 30 degree beams on NIF. This paper describes our “first pass” tuning the implosion velocity and shape on the National Ignition Facility laser [Moses et al., Phys. Plasmas, 16, 041006 (2009)].
Dynamic contraction of the positive column of a self-sustained glow discharge in molecular gas
Authors: Shneider M. N. , Mokrov M. S. , Milikh G. M.
Published: March 2012

In this paper the dynamic contraction of the current channel inside a quasineutral positive column of a self-sustained glow discharge in a rectangular duct with convection cooling is studied. A set of time-dependent two-dimensional equations for the molecular nitrogen is formulated, and then solved numerically. It is shown that, when the threshold condition for the ionization-thermal instability is fulfilled, a high density plasma channel starting from the initial perturbation near one electrode propagates to the opposite electrode. The developed steady-state contracted discharge is uniform along the direction of the current.
Control of post-disruption runaway electron beams in DIII-D
Authors: Eidietis N. W. , Commaux N. , Hollmann E. M. , Humphreys D. A. , Jernigan T. C. , Moyer R. A. , Strait E. J. , VanZeeland M. A. , Wesley J. C. , Yu J. H.
Published: March 2012

Recent experiments in the DIII-D tokamak have demonstrated real-time control and dissipation of post-disruption runaway electron (RE) beams. In the event that disruption avoidance, control, and mitigation schemes fail to avoid or suppress RE generation, active control of the RE beam may be an important line of defense to prevent the rapid, localized deposition of RE beam energy onto vulnerable vessel sections. During and immediately after the current quench, excessive radial compression of the runaway beams is avoided by a combination of techniques, improving the likelihood of the beams surviving this dynamic period without a fast termination. Once stabilized, the runaway beams are held in a steady state (out to the ohmic flux limit) with the application of active plasma current and position controls. Beam interaction with the vessel wall is minimized by avoiding distinct thresholds for enhanced wall interaction at small and large radii, corresponding to inner wall and outer limiter interaction, respectively. Staying within the “safe zone” between those radial thresholds allows for the sustainment of long-lived, quiescent runaway beams. The total beam energy and runaway electron population are then dissipated gradually by a controlled ramp-down of the runaway current.
Impurity transport in temperature gradient driven turbulence
Authors: Skyman A. , Nordman H. , Strand P.
Published: March 2012

In the present paper, the transport of impurities driven by trapped electron (TE) mode turbulence is studied. Non-linear (NL) gyrokinetic simulations using the code GENE are compared with results from quasilinear (QL) gyrokinetic simulations and a computationally efficient fluid model. The main focus is on model comparisons for electron temperature gradient driven turbulence regarding the sign of the convective impurity velocity (pinch) and the impurity density gradient R/LnZ (peaking factor) for zero impurity flux. In particular, the scaling of the impurity peaking factors with impurity charge Z and with driving temperature gradient is investigated and compared with results for the more studied ion temperature gradient (ITG) driven turbulence. The question of helium ash removal in TE mode turbulence is also investigated. In addition, the impurity peaking is compared to the main ion peaking obtained by a self-consistent fluid calculation of the density gradients corresponding to zero particle fluxes. For the scaling of the peaking factor with impurity charge Z, a weak dependence is obtained from NL GENE and fluid simulations. The QL GENE results show a stronger dependence for low Z impurities and overestimates the peaking factor by up to a factor of two in this region. As in the case of ITG dominated turbulence, the peaking factors saturate as Z increases, at a level much below neoclassical predictions. The scaling with Z is, however, weak or reversed as compared to the ITG case. The results indicate that TE mode turbulence is as efficient as ITG turbulence at removing He ash, with DHe/χeff>1.0. The scaling of impurity peaking with the background temperature gradients is found to be weak in the NL GENE and fluid simulations. The QL results are also here found to significantly overestimate the peaking factor for low Z values. For the parameters considered, the background density gradient for zero particle flux is found to be slightly larger than the corresponding impurity zero flux gradient.
Energy transformation in a reconnection site
Authors: Ma Z. W. , Sun H. E. , Lee L. C. , Lui A. T. Y.
Published: March 2012

We examine closely the 2D patterns of plasma parameters around a magnetic reconnection site using 212-D Darwin particle-in-cell simulation. Several simulation runs were conducted, one with open boundary condition and others with periodic boundary condition for the outflow region of magnetic reconnection for different system sizes. It is found that the 2D distributions of plasma parameters depend significantly on the outflow boundary condition and the system size of the simulation. In particular, it is found that the product JyEy is mainly positive (dissipation) around the X-line region, whereas it is mainly negative (dynamo) in the outflow region with a periodic boundary condition and a small system size. The dynamo effect arises from the compression of particles in the outflow region so that particle energies are transformed to electric and magnetic field energies for magnetic reconnection occurring with periodic boundary condition.
Energy expressions for Kohn–Sham potentials and their relation to the Slater–Janak theorem
Authors: Elkind Pavel D. , Staroverov Viktor N.
Published: March 2012

Direct approximation of exchange-correlation potentials is a promising approach to accurate prediction of molecular response properties. However, little is known about ways of obtaining total energies from model potentials other than by using the Levy–Perdew virial relation. We introduce and explore several alternative formulas which arise as line integrals of potentials taken along density scaling and aufbau-filling paths, and which are not limited to the exchange term. The relaxed-orbital variant of the aufbau-path energy expression is shown to be closely related to the Slater–Janak theorem. Although the Levy–Perdew relation generally yields reasonable energies for all model exchange potentials, the relaxed-orbital aufbau path gives better results for those potentials that predict accurate highest-occupied orbital eigenvalues, such as the potential of Räsänen, Pittalis, and Proetto [J. Chem. Phys. 132, 044112 (2010)]10.1063/1.3300063. The ideas presented in this work may guide the development of new types of density-functional approximations for exchange and correlation.
Expectation of ozone generation in alternating current corona discharges
Authors: Yehia Ashraf , Mizuno Akira
Published: March 2012

An analytical study was made in this paper to calculate the ozone generation inside an ac corona discharge reactor. The corona discharges were formed in a coaxial wire-cylinder reactor. The reactor was fed by dry air flowing with constant rates at atmospheric pressure and room temperature and stressed by an ac voltage. Concentration of the ozone generated inside the reactor was measured as a function of the ac corona current under different discharge conditions. An empirical equation was derived from the experimental results for calculating the ozone concentration generated inside the reactor. The results, that have been calculated by using the derived equation, have agreed with the experimental results over the whole range of the investigated parameters. Therefore, the derived equation represents a suitable criterion for expecting the ozone concentration that will generate by ac coronas in dry air fed coaxial wire-cylinder reactors under any discharge conditions in range of the investigated parameters.
Etching properties and electrical characterization of surfaces of silicon-on-insulator substrates in presence of halogens
Authors: Abbadie A. , Hamaide G. , Mariolle D. , Chaupin M. , Brunier F. , Martinez E. , Mähliß J.
Published: March 2012

We have studied the etching properties of silicon-on-insulator (SOI) substrates in recently developed chromium-free solutions containing halogens. We have shown that the presence of halogen compounds X (I−, Br−…) in HF/HNO3/CH3COOH solutions is required for a selective and preferential etching on SOI. The etching rate of such solutions increases with the dissolved halogen concentrations. The chemical reactivity of Si-X (X = Br−, I−..) bonds has been analyzed by X-ray Photoelectron Spectroscopy (XPS), Pseudo-MOS (flatband potential) and Kelvin Force Microscopy (KFM) measurements. A negative shift of flatband potential values is explained by an increasing concentration of halogen compounds in the solution and a substitution of Si-H (F) bonds by Si-X bonds during the reaction. Though Si-X bonds, and more particularly Si-I bonds, have been confirmed only at trace levels using XPS, we believe that the formation of Si-X bonds is supported by a mechanism of surface dipoles. Unexpectedly, no significant change in work function could be detected using KFM measurements. Some suggestions, based on KFM technique improvements, are made to explain such results. Finally, though the interaction mechanism between silicon, fluoride, iodide, and nitric acid is not clearly elucidated by our experimental results, the formation of Si-halogen bonds is crucial for etching and defect decoration capability.
Electron injection and acceleration in the plasma bubble regime driven by an ultraintense laser pulse combined with using dense-plasma wall and block
Authors: Zhao Xue-Yan , Xie Bai-Song , Wu Hai-Cheng , Zhang Shan , Hong Xue-Ren , Aimidula Aimierding
Published: March 2012

An optimizing and alternative scheme for electron injection and acceleration in the wake bubble driven by an ultraintense laser pulse is presented. In this scheme, the dense-plasma wall with an inner diameter matching the expected bubble size is placed along laser propagation direction. Meanwhile, a dense-plasma block dense-plasma is adhered inward transversely at some certain position of the wall. Particle-in-cell simulations are performed, which demonstrate that the block plays an important role in the first electron injection and acceleration. The result shows that a collimated electron bunch with a total number of about 4.04×108μm-1 can be generated and accelerated stably to 1.61 GeV peak energy with 2.6% energy spread. The block contributes about 50% to the accelerated electron injection bunch by tracing and sorting statistically the source.
UV photodissociation dynamics of iodobenzene: Effects of fluorination
Authors: Murdock Daniel , Crow Martin B. , Ritchie Grant A. D. , Ashfold Michael N. R.
Published: March 2012

The UV photochemistry of various fluorinated iodobenzenes (4-fluoro-, 2,4-difluoro-, 3,5-difluoro-, and perfluoro-iodobenzene) has been investigated at many wavelengths by velocity map imaging, time-resolved near infrared absorption spectroscopy and (spin-orbit resolved) ab initio calculations of the ground and excited state potentials along the C–I stretch coordinate, RC–I. The textbook description of the near UV photochemistry of CH3I, i.e., σ*←n excitation to the 3Q0+ state, followed by direct dissociation (to yield spin-orbit excited iodine atom (I*) products) or by non-adiabatic coupling via a conical intersection (CI) with the 1Q1 potential (to yield ground state iodine (I) atoms) is shown to provide a good zero-order model for aryl iodide photochemistry also. However, the aryl halides also possess occupied π and low-lying π* orbitals, and have lower (C2v or Cs) symmetry than CH3I. Both of these factors introduce additional subtleties. For example, excitations to and predissociation of ππ* excited states provide additional routes to I products, most obviously at long UV wavelengths. nσ*/πσ* configuration mixing stabilizes the (analogue of the) 3Q0+ potential energy surface (PES), to an extent that scales with the degree of fluorination; the corresponding 4A1 PES in C6F5I is actually predicted to exhibit a minimum at extended RC–I. This has the effect of extending the long wavelength threshold for forming I* products. The lowered symmetry enables an additional (sloped) CI with the 5A2 (9A″ in 2,4-difluorobenzene) PES, which provides an extra non-adiabatic route to (fast) ground state I atoms when populating the 4A1 PES at shorter UV excitation wavelengths.