bluuebunny/crossref_metadata_2025 huggingface dataset:
Effective freezing rate for semen cryopreservation in endangered Mediterranean brown trout (Salmo trutta macrostigma) inhabiting the Biferno river (South Italy)
Authors: Iaffaldano Nicolaia , Di Iorio Michele , Manchisi Angelo , Esposito Stefano , Gibertoni Pier Paolo
Published: December 2015

This study was designed to determine: (i) thein vitroeffects of different freezing rates on post-thaw semen quality of Mediterranean brown trout (Salmo trutta macrostigma) from the Biferno river; and (ii) thein vivofertilization and hatching percentage of freezing rate giving rise to the best post-thaw semen quality.

Pooled semen samples were diluted 1:3 (v:v) in a freezing extender composed of 300 mM glucose, 10% egg yolk and 10% dimethyl sulfoxide (DMSO). The extended semen was packaged in 0.25 ml plastic straws and frozen at different heights above the liquid nitrogen surface (1, 5 or 10 cm) for 10 min to give three different freezing rates. Semen samples were thawed at 30°C for 10 s. The variables assessed after thawing were sperm motility, duration of motility and viability.

Our results clearly indicate a significant effect of freezing rate on post-thaw semen quality. Semen frozen 5 cm above the liquid nitrogen surface showed the best quality after freezing/thawing. Based on thesein vitrodata, 2 groups of 200 eggs were fertilized with fresh semen or semen frozen 5 cm above the liquid nitrogen surface. Fertilization and hatching rates recorded for eggs fertilized with frozen semen were significantly lower (25.4% and 22.5%, respectively) than the ones obtained using fresh semen (87.8% and 75.5%, respectively). An effective freezing protocol will allow for the creation of a sperm cryobank to recover the original population of Mediterranean brown trout in the Biferno river.
Systemic rapamycin to prevent in-stent stenosis in peripheral pulmonary arterial disease: early clinical experience
Authors: Hallbergson Anna , Esch Jesse J. , Tran Trang X. , Lock James E. , Marshall Audrey C.
Published: December 2015

Objectives

We have taken a novel approach using oral rapamycin – sirolimus – as a medical adjunct to percutaneous therapy in patients with in-stent stenosis and high risk of right ventricular failure.

Background

Peripheral pulmonary artery stenosis can result in right ventricular hypertension, dysfunction, and death. Percutaneous pulmonary artery angioplasty and stent placement acutely relieve obstructions, but patients frequently require re-interventions due to re-stenosis. In patients with tetralogy of Fallot or arteriopathy, the problem of in-stent stenosis contributes to the rapidly recurrent disease.

Methods

Rapamycin was administered to 10 patients (1.5–18 years) with peripheral pulmonary stenosis and in-stent stenosis and either right ventricular hypertension, pulmonary blood flow maldistribution, or segmental pulmonary hypertension. Treatment was initiated around the time of catheterisation and continued for 1–3 months. Potential side-effects were monitored by clinical review and blood tests.

Results

Target serum rapamycin level (6–10 ng/ml) was accomplished in all patients; eight of the nine patients who returned for clinically indicated catheterisations demonstrated reduction in in-stent stenosis, and eight of the 10 patients experienced no significant side-effects. Among all, one patient developed diarrhoea requiring drug discontinuation, and one patient experienced gastrointestinal bleeding while on therapy that was likely due to an indwelling feeding tube and this patient tolerated rapamycin well following tube removal.

Conclusions

Our initial clinical experience supports that patients with peripheral pulmonary artery stenosis can be safely treated with rapamycin. Systemic rapamycin may provide a novel medical approach to reduce in-stent stenosis.
Neuropsychological Correlates of Hazard Perception in Older Adults
Authors: McInerney Katalina , Suhr Julie
Published: December 2015

Objectives:Hazard perception, the ability to identify and react to hazards while driving, is of growing importance in driving research, given its strong relationship to real word driving variables. Furthermore, although poor hazard perception is associated with novice drivers, recent research suggests that it declines with advanced age. In the present study, we examined the neuropsychological correlates of hazard perception in a healthy older adult sample.Methods:A total of 68 adults age 60 and older who showed no signs of dementia and were active drivers completed a battery of neuropsychological tests as well as a hazard perception task. Tests included the Repeatable Battery for the Assessment of Neuropsychological Status, Wechsler Test of Adult Reading, Trail Making Test, Block Design, Useful Field of View, and the Delis-Kaplan Executive Function System Color Word Interference Test.Results:Hazard perception errors were related to visuospatial/constructional skills, processing speed, memory, and executive functioning skills, with a battery of tests across these domains accounting for 36.7% of the variance in hazard perception errors. Executive functioning, particularly Trail Making Test part B, emerged as a strong predictor of hazard perception ability.Conclusions:Consistent with prior work showing the relationship of neuropsychological performance to other measures of driving ability, neuropsychological performance was associated with hazard perception skill. Future studies should examine the relationship of neuropsychological changes in adults who are showing driving impairment and/or cognitive changes associated with Mild Cognitive Impairment or dementia. (JINS, 2015,21, 332–340)
Carbonization in Titan Tholins: implication for low albedo on surfaces of Centaurs and trans-Neptunian objects
Authors: Giri Chaitanya , McKay Christopher P. , Goesmann Fred , Schäfer Nadine , Li Xiang , Steininger Harald , Brinckerhoff William B. , Gautier Thomas , Reitner Joachim , Meierhenrich Uwe J.
Published: December 2015

Astronomical observations of Centaurs and trans-Neptunian objects (TNOs) yield two characteristic features – near-infrared (NIR) reflectance and low geometric albedo. The first feature apparently originates due to complex organic material on their surfaces, but the origin of the material contributing to low albedo is not well understood. Titan tholins synthesized to simulate aerosols in the atmosphere of Saturn's moon Titan have also been used for simulating the NIR reflectances of several Centaurs and TNOs. Here, we report novel detections of large polycyclic aromatic hydrocarbons, nanoscopic soot aggregates and cauliflower-like graphite within Titan tholins. We put forth a proof of concept stating the surfaces of Centaurs and TNOs may perhaps comprise of highly ‘carbonized’ complex organic material, analogous to the tholins we investigated. Such material would apparently be capable of contributing to the NIR reflectances and to the low geometric albedos simultaneously.
Electric "Tornadoes" in Space Drive Disturbances Down to Earth
Authors: Zastrow Mark
Published: December 2015

New simulations show how shocks in space can trigger vortexes in Earth's magnetic field, causing magnetic disturbances that are detectable from the ground.
Divergent reactivity of an indole glucosinolate yields Lossen or Neber rearrangement products: the phytoalexin rapalexin A or a unique β-d-glucopyranose fused heterocycle
Authors: Pedras M. S. C. , To Q. H. , Schatte G.
Published: December 2015

Transformation of an indole-3-glucosinolate under acidic conditions yielded the potent phytoalexin rapalexin A, via Lossen type rearrangement, while a novel glucopyranose heterocyclic system was obtained under basic conditions via Neber type rearrangement.
Correction: Unexpected higher stabilisation of two classical antiaromatic frameworks with a ruthenium fragment compared to the osmium counterpart: origin probed by DFT calculations
Authors: Wu Jingjing , Hao Yulei , An Ke , Zhu Jun
Published: December 2015

Correction for ‘Unexpected higher stabilisation of two classical antiaromatic frameworks with a ruthenium fragment compared to the osmium counterpart: origin probed by DFT calculations’ by Jingjing Wu et al., Chem. Commun., 2016, 52, 272–275.
Intrinsic coordination for revealing local structural changes in protein folding–unfolding
Authors: Shiu Ying-Jen , Hayashi Michitoshi , Shih Orion , Su Charlene , Tsai Min-Yeh , Yeh Yi-Qi , Su Chun-Jen , Huang Yu-Shan , Lin Sheng-Hsien , Jeng U-Ser
Published: December 2015

The local dislocations may be tracked relatively easily with respect to the internal rigid rod.
Synthesis and characterization of [Fe(NCCH3)6][cis-Fe(InX3)2(CO)4] (X = Cl, Br, I) containing two terminal indium fragments
Authors: Itazaki Masumi , Ito Masaki , Nakashima Satoru , Nakazawa Hiroshi
Published: December 2015

The first example of iron complexes containing two Fe–In covalent bonds, [Fe(NCCH3)6][cis-Fe(InX3)2(CO)4] (X = Cl:1, Br:2, I:3), were synthesized and the bonding mode of the Fe–In bonds in the anionic part was investigated using57Fe Mössbauer and IR spectroscopy.
Photophysical properties of single core multimodal probe for imaging (SCoMPI) in a membrane model and in cells
Authors: Hostachy S. , Swiecicki J.-M. , Sandt C. , Delsuc N. , Policar C.
Published: December 2015

An unexpected strong luminescence enhancement of a bimodal ReCO probe grafted onto a CPP accurately characterized in a lipid environment.
The synthesis and unexpected solution chemistry of thermochromic carborane-containing osmium half-sandwich complexes
Authors: Pitto-Barry Anaïs , South Amy , Rodger Alison , Barry Nicolas P. E.
Published: December 2015

The functionalisation of the 16-electron complex [Os(η6-p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-dithiolato)] (1) with a series of Lewis bases to give the corresponding 18-electron complexes is reported.
Copper(ii) mixed-ligand polypyridyl complexes with doxycycline – structures and biological evaluation
Authors: Abosede Olufunso O. , Vyas Nilima A. , Singh Sushma B. , Kumbhar Avinash S. , Kate Anup , Kumbhar Anupa A. , Khan Ayesha , Erxleben Andrea , Smith Peter , de Kock Carmen , Hoffmann Frank , Obaleye Joshua A.
Published: December 2015

Structures and biological evaluation of Cu(ii) mixed-ligand polypyridyl complexes with doxycycline of the type [Cu(doxycycline)(L)(H2O)2](NO3)2, L = 2,2′-bipyridine (bpy, 1), 1,10-phenanthroline (phen, 2), dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq, 3) and dipyrido[3,2-a:2′,3′-c]phenazine (dppz, 4).
Correction: Palladium(ii) complexes with chelating N-phosphanyl acyclic diaminocarbenes: synthesis, characterization and catalytic performance in Suzuki couplings
Authors: Marchenko Anatoliy , Koidan Georgyi , Hurieva Anastasiya , Vlasenko Yurii , Kostyuk Aleksandr , Biffis Andrea
Published: December 2015

Correction for ‘Palladium(ii) complexes with chelating N-phosphanyl acyclic diaminocarbenes: synthesis, characterization and catalytic performance in Suzuki couplings’ by Anatoliy Marchenko et al., Dalton Trans., 2016, DOI: 10.1039/c5dt02250a.
Glass-amorphous alkali-ion solid electrolytes and their performance in symmetrical cells
Authors: Braga M. Helena , Murchison Andrew J. , Ferreira Jorge A. , Singh Preetam , Goodenough John B.
Published: December 2015

Precursors of the crystalline antiperovskites A3−xHxOCl (A = Li or Na and 0 < x < 1) can be rendered glass/amorphous solid Li+ or Na+ electrolytes by the addition of water to its solvation limit with/without the addition of a small amount of an oxide or hydroxide.
Transforming biomass conversion with ionic liquids: process intensification and the development of a high-gravity, one-pot process for the production of cellulosic ethanol
Authors: Xu Feng , Sun Jian , Konda N. V. S. N. Murthy , Shi Jian , Dutta Tanmoy , Scown Corinne D. , Simmons Blake A. , Singh Seema
Published: December 2015

Producing concentrated sugars and minimizing water usage are key elements in the economics and environmental sustainability of advanced biofuels.
Highly efficient I2 capture by simple and low-cost deep eutectic solvents
Authors: Li Guofeng , Yan Chuanyu , Cao Bobo , Jiang Jingyun , Zhao Wancheng , Wang Jinfang , Mu Tiancheng
Published: December 2015

The efficient removal and storage of radioactive nuclear contaminants of iodine has been realized by deep eutectic solvents (DESs) due to the formation of halogen bonding (XB).
Experimental and numerical studies on standing surface acoustic wave microfluidics
Authors: Mao Zhangming , Xie Yuliang , Guo Feng , Ren Liqiang , Huang Po-Hsun , Chen Yuchao , Rufo Joseph , Costanzo Francesco , Huang Tony Jun
Published: December 2015

We numerically and experimentally investigate the acoustophoresis of microparticles in standing surface acoustic wave microfluidic devices.
Tandem buildup of complexity of aromatic molecules through multiple successive electrophile generation in one pot, controlled by varying the reaction temperature
Authors: Sumita Akinari , Otani Yuko , Ohwada Tomohiko
Published: December 2015

The unmasking reaction rates and the time of generation of highly reactive electrophiles can be controlled. This reaction system demonstrates the conceptual validity of one-pot build-up of a complex aromatic molecule from multiple starting components.
Wavelength-selective light-triggered strand exchange reaction
Authors: Morihiro K. , Kodama T. , Mori S. , Tsunoda S. , Obika S.
Published: December 2015

Light-triggered strand exchange reaction in a wavelength-selective manner utilizing two types of photolabile groups.
Novel Al2O3–SiO2composite aerogels with high specific surface area at elevated temperatures with different alumina/silica molar ratios prepared by a non-alkoxide sol–gel method
Authors: Wu Xiaodong , Shao Gaofeng , Shen Xiaodong , Cui Sheng , Wang Ling
Published: December 2015

We have developed a new sol–gel route to synthesise Al2O3–SiO2composite aerogels with different alumina/silica (Al/Si) molar ratios using an inexpensive inorganic salt.
Polyacrylonitrile (PAN)/crown ether composite nanofibers for the selective adsorption of cations
Authors: Tas Sinem , Kaynan Ozge , Ozden-Yenigun Elif , Nijmeijer Kitty
Published: December 2015

Electrospun PAN/crown ether nanofibers have potential for selective recovery of specific ions from mixtures with ions.
Well-defined and biocompatible hydrogels with toughening and reversible photoresponsive properties
Authors: Sun Zhiqiang , Liu Shunli , Li Kewen , Tan Linhua , Cen Lian , Fu Guodong
Published: December 2015

A novel hydrogel with high strength, reversible photoresponsive and excellent biocompatible properties was fabricated.
Iron-based sodium-ion full batteries
Authors: Ye Hualin , Wang Yeyun , Zhao Feipeng , Huang Wenjing , Han Na , Zhou Junhua , Zeng Min , Li Yanguang
Published: December 2015

Iron-based sodium-ion batteries are constructed using improved iron oxide anode and Prussian blue cathode.
Development of green to near-infrared turn-on fluorescent probes for the multicolour imaging of nitroxyl in living systems
Authors: Dong Baoli , Zheng Kaibo , Tang Yonghe , Lin Weiying
Published: December 2015

The green to near-infrared turn-on fluorescent probes were developed for the multicolour imaging of nitroxyl in living systems.
Ferrocene-containing poly(fluorenylethynylene)s for nonvolatile resistive memory devices
Authors: Xiang Jing , Wang Tai-Kang , Zhao Qiang , Huang Wei , Ho Cheuk-Lam , Wong Wai-Yeung
Published: December 2015

The memory behaviours of the prepared ferrocene-containing poly(fluorenylethynylene)s (PFcFE) can be easily tuned by changing the chemical structures of the embedded aromatic building blocks.
Dielectric investigation of high-k yttrium copper titanate thin films
Authors: Monteduro Anna Grazia , Ameer Zoobia , Martino Maurizio , Caricato Anna Paola , Tasco Vittorianna , Lekshmi I. C. , Rinaldi Ross , Hazarika Abhijit , Choudhury Debraj , Sarma D. D. , Maruccio Giuseppe
Published: December 2015

We report on the first dielectric investigation of high-k yttrium copper titanate thin films, which were demonstrated to be very promising for nanoelectronics applications.
Five SGD Funding Rules of Commitment
Authors: Wiles Higdon Carolyn , Hill Katya
Published: December 2015

This article focuses on policy documents of the American Speech-Language-Hearing Association (ASHA) that provide guidance to SLPs facing the various issues and challenges of conducting AAC evaluations that result in a speech-generating device (SGD) funding request. Five (5) SGD funding rules of commitment are proposed for speech-language pathologists (SLPs) to consider in their clinical practice regardless of the funding source (e.g., school districts, Medicare, Medicaid, major health insurers, or private pay). The rules highlight ethical conduct, advocacy, and consumer protection. SLPs having questions about SGD funding practices and requirements should contact the appropriate ASHA service staff with their questions as the primary source of information and guidance.
Facilitating Family and Client Involvement in the SGD Evaluation and Decision Process
Authors: Mitchell Pamela R. , Alvares Robin
Published: December 2015

There is general consensus that client and family involvement in the augmentative and alternative communication (AAC) evaluation and decision process is associated with positive outcomes (Angelo, 2000; Bailey, Parette, Stoner, Angell, & Carroll, 2006; Parette & Angelo, 1996). This paper explores the importance of client and family involvement, summarizes research-based strategies that have been associated with improvements in family involvement and team collaborations, and presents clinically applicable strategies that may be used to foster client and family engagement and empowerment in the AAC decision-making process.
Direct power control of voltage source inverter in a virtual synchronous reference frame during frequency variation and network unbalance
Authors: Cheng Peng , Nian Heng
Published: December 2015

This study proposes a direct power control (DPC) scheme for grid‐connected voltage source inverter (VSI) in a virtual synchronous reference frame during frequency variations and network unbalances. The proposed DPC scheme applies a virtual phase angle instead of the voltage phase angle acquired by the phase‐locked loop (PLL) for coordinated transformations. This approach can eliminate the PLL and its low‐frequency‐oscillatory behaviours during the frequency variations. Meanwhile, two available control targets, that is, smooth active power and smooth reactive power, are defined for the VSI operation during network unbalance. In the proposed DPC scheme, the reduced‐order vector integrator is employed to directly regulate the power pulsations caused by the voltage unbalances. Consequently, it can eliminate both the sequential separations of the voltages/currents and the complex calculations of the power compensating components. Then, based on the mathematical model of the VSI control system, the control performance, including the steady‐state power errors and the system stability, is fully analysed. Finally, both the simulation and experimental results are provided to confirm the effectiveness of the proposed DPC scheme.
The spin-partitioned total position-spread tensor: An application to Heisenberg spin chains
Authors: Fertitta Edoardo , El Khatib Muammar , Bendazzoli Gian Luigi , Paulus Beate , Evangelisti Stefano , Leininger Thierry
Published: December 2015

The spin partition of the Total Position-Spread (TPS) tensor has been performed for one-dimensional Heisenberg chains with open boundary conditions. Both the cases of a ferromagnetic (high-spin) and an anti-ferromagnetic (low-spin) ground-state have been considered. In the case of a low-spin ground-state, the use of alternating magnetic couplings allowed to investigate the effect of spin-pairing. The behavior of the spin-partitioned TPS (SP-TPS) tensor as a function of the number of sites turned to be closely related to the presence of an energy gap between the ground-state and the first excited-state at the thermodynamic limit. Indeed, a gapped energy spectrum is associated to a linear growth of the SP-TPS tensor with the number of sites. On the other hand, in gapless situations, the spread presents a faster-than-linear growth, resulting in the divergence of its per-site value. Finally, for the case of a high-spin wave function, an analytical expression of the dependence of the SP-TPS on the number of sites n and the total spin-projection Sz has been derived.
A simple expression for pressure drops of water and other low molecular liquids in the flow through micro-orifices
Authors: Hasegawa Tomiichi , Ushida Akiomi , Narumi Takatsune
Published: December 2015

Flows are generally divided into two types: shear flows and shear-free elongational (extensional) flows. Both are necessary for a thorough understanding of the flow properties of a fluid. Shear flows are easy to achieve in practice, for example, through Poiseuille or Couette flows. Shear-free elongational flows are experimentally hard to achieve, resulting in an incomplete understanding of the flow properties of fluids in micro-devices. Nevertheless, flows through micro-orifices are useful for probing the properties of elongational flows at high elongational rates; although these flows exhibit shear and elongation, the elongation is dominant and the shear is negligible in the central region of the flows. We previously reported an anomalous reduction in pressure drops in the flows of water, a 50/50 mixture of glycerol and water, and silicone oils through micro-orifices. In the present paper, we rearrange the data presented in the previous paper and reveal a simple relationship where the pressure drop is proportional to the velocity through the micro-orifices, independent of the orifice diameter and the viscosity of the liquids tested. We explain our observations by introducing a “fluid element” model, in which fluid elements are formed on entering the orifice. The model is based on the idea that low molecular liquids, including water, generate strong elongational stress, similar to a polymer solution, in the flow through micro-orifices.
Jet arrays in supersonic crossflow — An experimental study
Authors: Ali Mohd Yousuf , Alvi Farrukh
Published: December 2015

Jet injection into a supersonic crossflow is a classical fluid dynamics problem with many engineering applications. Several experimental and numerical studies have been taken up to analyze the interaction of a single jet with the incoming crossflow. However, there is a dearth of the literature on the interaction of multiple jets with one another and with the crossflow. Jets in a supersonic crossflow are known to produce a three-dimensional bow-shock structure due to the blockage of the flow. Multiple jets in a streamwise linear array interact with both one another and the incoming supersonic flow. In this paper, a parametric study is carried out to analyze the effect of microjet (sub-mm diameter) injection in a Mach 1.5 supersonic crossflow using flow visualization and velocity field measurements. The variation of the microjet orifice diameter and spacing within an array is used to study the three-dimensional nature of the flow field around the jets. The strength of the microjet-generated shock, scaling of the shock wave angle with the momentum coefficient, averaged streamwise, spanwise, and cross-stream velocity fields, and microjet array trajectories are detailed in the paper. It was found that shock angles of the microjet-generated shocks scale with the momentum coefficient for the three actuator configurations tested. As the microjets issue in the crossflow, a pair of longitudinal counter-rotating vortices (CVPs) are formed. The vortex pairs remain coherent for arrays with larger spanwise spacing between the micro-orifices and exhibit significant three-dimensionality similar to that of a single jet in crossflow. As the spacing between the jets is reduced, the CVPs merge resulting in a more two-dimensional flow field. The bow shock resulting from microjet injection also becomes nearly two-dimensional as the spacing between the micro-orifices is reduced. Trajectory estimations yield that microjets in an array have similar penetration as single jets. A notional schematic depicting the interaction of the microjet arrays with the supersonic crossflow is presented summarizing the principal features of the interaction.
Carbon doped GaN buffer layer using propane for high electron mobility transistor applications: Growth and device results
Authors: Li X. , Bergsten J. , Nilsson D. , Danielsson Ö. , Pedersen H. , Rorsman N. , Janzén E. , Forsberg U.
Published: December 2015

The creation of a semi insulating (SI) buffer layer in AlGaN/GaN High Electron Mobility Transistor (HEMT) devices is crucial for preventing a current path beneath the two-dimensional electron gas (2DEG). In this investigation, we evaluate the use of a gaseous carbon gas precursor, propane, for creating a SI GaN buffer layer in a HEMT structure. The carbon doped profile, using propane gas, is a two stepped profile with a high carbon doping (1.5 × 1018 cm−3) epitaxial layer closest to the substrate and a lower doped layer (3 × 1016 cm−3) closest to the 2DEG channel. Secondary Ion Mass Spectrometry measurement shows a uniform incorporation versus depth, and no memory effect from carbon doping can be seen. The high carbon doping (1.5 × 1018 cm−3) does not influence the surface morphology, and a roughness root-mean-square value of 0.43 nm is obtained from Atomic Force Microscopy. High resolution X-ray diffraction measurements show very sharp peaks and no structural degradation can be seen related to the heavy carbon doped layer. HEMTs are fabricated and show an extremely low drain induced barrier lowering value of 0.1 mV/V, demonstrating an excellent buffer isolation. The carbon doped GaN buffer layer using propane gas is compared to samples using carbon from the trimethylgallium molecule, showing equally low leakage currents, demonstrating the capability of growing highly resistive buffer layers using a gaseous carbon source.
Evolution of streamer groups in nonthermal plasma
Authors: Okubo M.
Published: December 2015

Nonthermal plasmas (NTPs) induced by atmospheric nanosecond pulsed corona discharge have been studied for controlling pollution from combustors, such as boilers, incinerators, and diesel engines. In high-speed short-width high-voltage pulsed corona discharge-induced plasmas, primary streamer evolution is followed by secondary streamer evolution. Though this phenomenon is known experimentally, the details of the structures of the streamers and their evolution mechanisms have not been fully clarified. In this letter, we perform quasi two-dimensional numerical analysis of nonequilibrium NTP induced by a nanosecond positive pulsed corona discharge. The continuum fluid equations for two-temperature nonequilibrium NTP are used as governing equations. In this study, 197 gas phase reactions for 25 chemical species and 21 surface reactions on the inner glass wall surface are considered in an air plasma under atmospheric pressure. The simulated behavior of the streamer groups agrees with experimental observations. Soon after the voltage increases on the reactor, primary streamers are formed, which may transit the complete gap, disappearing near the peak voltage. Next, second streamers appear, disappearing at the end of the applied voltage pulse. The streamer wavelength and the distance between the streamers in the axial direction are determined. Moreover, ozone generation is shown to be more significant in the secondary streamer. This simulation will allow better predictions for nanosecond positive pulsed plasma systems.
Invited Article: Progress in coherent lithography using table-top extreme ultraviolet lasers
Authors: Li W. , Urbanski L. , Marconi M. C.
Published: December 2015

Compact (table top) lasers emitting at wavelengths below 50 nm had expanded the spectrum of applications in the extreme ultraviolet (EUV). Among them, the high-flux, highly coherent laser sources enabled lithographic approaches with distinctive characteristics. In this review, we will describe the implementation of a compact EUV lithography system capable of printing features with sub-50 nm resolution using Talbot imaging. This compact system is capable of producing consistent defect-free samples in a reliable and effective manner. Examples of different patterns and structures fabricated with this method will be presented.
The geometric mean squared displacement and the Stokes-Einstein scaling in a supercooled liquid
Authors: Saw Shibu , Harrowell Peter
Published: December 2015

It is proposed that the rate of relaxation in a liquid is better described by the geometric mean of the van Hove distribution function, rather than the standard arithmetic mean used to obtain the mean squared displacement. The difference between the two means is shown to increase significantly with an increase in the non-Gaussian character of the displacement distribution. Preliminary results indicate that the geometric diffusion constant results in a substantial reduction of the deviation from Stokes-Einstein scaling.
An effect of the electrode material on space charge relaxation in ferroelectric copolymers of vinylidene fluoride
Authors: Kochervinskii Valentin , Malyshkina Inna , Pavlov Alexey , Pakuro Natalia , Bessonova Natalia , Shmakova Nina , Bedin Sergey , Chubunova Elena , Lebedinskii Yuri
Published: December 2015

Processes of relaxation of space charges formed by impurities carriers in isotropic films of vinylidene fluoride and tetrafluoroethylene copolymers of the composition 71/29 and 94/6 were studied. Al and Au symmetric electrodes deposited by evaporation in vacuum have been used. In the case of Al electrodes at temperatures above 100 °C, giant low frequency dielectric dispersion was observed, while it is absent in films with Au electrodes. Causes of this phenomenon were studied by the X-ray photoelectron spectroscopy. It was shown that at Al deposition, new functional groups, such as Al-C, Al-F, and Al2O3, which are not characteristic of the copolymer film surface, formed. They were supposed to be traps for impurity carriers and because of this the electrode became partially blocked. This led to appearance of the giant electrode polarization on the metal-polymer boundary, which did not take place in the case of Au electrodes. Parameters of the Au4f line for the copolymer with different contents of fluorine atoms in the chain were analyzed. An increase in the number of these atoms was shown to result in the line shift to higher energies. This phenomenon was associated with an increase in the shift of the electron density from Au atoms to the F ones which has a high affinity to electrons.
Multistability of synchronous regimes in rotator ensembles
Authors: Kryukov A. K. , Petrov V. S. , Osipov G. V. , Kurths J.
Published: December 2015

We study collective dynamics in rotator ensembles and focus on the multistability of synchronous regimes in a chain of coupled rotators. We provide a detailed analysis of the number of coexisting regimes and estimate in particular, the synchronization boundary for different types of individual frequency distribution. The number of wave-based regimes coexisting for the same parameters and its dependence on the chain length are estimated. We give an analytical estimation for the synchronization frequency of the in-phase regime for a uniform individual frequency distribution.
High speed low power optical detection of sub-wavelength scatterer
Authors: Roy S. , Bouwens Maryse , Wei Lei , Pereira S. F. , Urbach H. P. , van der Walle P.
Published: December 2015

Optical detection of scatterers on a flat substrate, generally done using dark field microscopy technique, is challenging since it requires high power illumination to obtain sufficient SNR (Signal to Noise Ratio) to be able to detect sub-wavelength particles. We developed a bright field technique, based on Fourier scatterometry, with special illumination and detection control to achieve this goal with a power level that can be sustained by most substrates including polymers. The performance of the system in a roll-to-roll line in production environment and strict throughput requirement is shown.
Yttrium aluminium garnet under pressure: Structural, elastic, and vibrational properties from ab initio studies
Authors: Monteseguro V. , Rodríguez-Hernández P. , Muñoz A.
Published: December 2015

The structural, elastic, and vibrational properties of yttrium aluminum garnet Y3Al5O12 are studied under high pressure by ab initio calculations in the framework of the density functional theory. The calculated ground state properties are in good agreement with the available experimental data. Pressure dependences of bond length and bulk moduli of the constituent polyhedra are reported. The evolution of the elastic constants and the major elastic properties, Young and shear modulus, Poisson's ratios, and Zener anisotropy ratio, are described. The mechanical stability is analyzed, on the light of “Born generalized stability criteria,” showing that the garnet is mechanically unstable above 116 GPa. Symmetries, frequencies, and pressure coefficients of the Raman-active modes are discussed on the basis of the calculated total and partial phonon density of states, which reflect the dynamical contribution of each atom. The relations between the phonon modes of Y3Al5O12 and the internal and external molecular modes of the different polyhedra are discussed. Infrared-active modes, as well as the silent modes, and their pressure dependence are also investigated. No dynamical instabilities were found below 116 GPa.
Shape change and Peierls barrier of dislocation
Authors: Wang Shaofeng , Zhang Shujun , Bai Jianhui , Yao Yin
Published: December 2015

Shape change and Peierls barrier of dislocation are investigated theoretically in the framework of the improved Peierls-Nabarro model in which the lattice discreteness is considered fully. We found that the dislocation will become narrow as it moves from the energy valley to the barrier top. An expression for the Peierls barrier is proposed based on our calculations without the rigid translation assumption. The results enable us to relate the Peierls stress to the bulk properties of crystals directly and can be easily used in the evaluation of material plasticity.
Confocal detection of Rayleigh scattering for residual stress measurement in chemically tempered glass
Authors: Hödemann S. , Möls P. , Kiisk V. , Murata T. , Saar R. , Kikas J.
Published: December 2015

A new optical method is presented for evaluation of the stress profile in chemically tempered (chemically strengthened) glass based on confocal detection of scattered laser beam. Theoretically, a lateral resolution of 0.2 μm and a depth resolution of 0.6 μm could be achieved by using a confocal microscope with high-NA immersion objective. The stress profile in the 250 μm thick surface layer of chemically tempered lithium aluminosilicate glass was measured with a high spatial resolution to illustrate the capability of the method. The confocal method is validated using transmission photoelastic and Na+ ion concentration profile measurement. Compositional influence on the stress-optic coefficient is calculated and discussed. Our method opens up new possibilities for three-dimensional scattered light tomography of mechanical imaging in birefringent materials.
Electron Debye scale Kelvin-Helmholtz instability: Electrostatic particle-in-cell simulations
Authors: Lee Sang-Yun , Lee Ensang , Kim Khan-Hyuk , Lee Dong-Hun , Seon Jongho , Jin Ho
Published: December 2015

In this paper, we investigated the electron Debye scale Kelvin-Helmholtz (KH) instability using two-dimensional electrostatic particle-in-cell simulations. We introduced a velocity shear layer with a thickness comparable to the electron Debye length and examined the generation of the KH instability. The KH instability occurs in a similar manner as observed in the KH instabilities in fluid or ion scales producing surface waves and rolled-up vortices. The strength and growth rate of the electron Debye scale KH instability is affected by the structure of the velocity shear layer. The strength depends on the magnitude of the velocity and the growth rate on the velocity gradient of the shear layer. However, the development of the electron Debye scale KH instability is mainly determined by the electric field generated by charge separation. Significant mixing of electrons occurs across the shear layer, and a fraction of electrons can penetrate deeply into the opposite side fairly far from the vortices across the shear layer.
A comparison between spectra of runaway electron beams in SF6 and air
Authors: Zhang Cheng , Tarasenko Victor , Gu Jianwei , Baksht Evgenii , Wang Ruexue , Yan Ping , Shao Tao
Published: December 2015

Runaway electron (RAE) with extremely high-energy plays important role on the avalanche propagation, streamer formation, and ionization waves in nanosecond-pulse discharges. In this paper, the generation of a supershort avalanche electron beam (SAEB) in SF6 and air in an inhomogeneous electric field is investigated. A VPG-30-200 generator with a pulse rise time of ∼1.6 ns and a full width at half maximum of 3–5 ns is used to produce RAE beams. The SAEBs in SF6 and air are measured by using aluminum foils with different thicknesses. Furthermore, the SAEB spectra in SF6 and air at pressures of 7.5 Torr, 75 Torr, and 750 Torr are compared. The results showed that amplitude of RAE beam current generated at the breakdown in SF6 was approximately an order of magnitude less than that in air. The energy of SAEB in air was not smaller than that in SF6 in nanosecond-pulse discharges under otherwise equal conditions. Moreover, the difference between the maximum energy of the electron distributions in air and SF6 decreased when the rise time of the voltage pulse increased. It was because the difference between the breakdown voltages in air and SF6 decreased when the rise time of the voltage pulse increased.
Simultaneous estimation of free energies and rates using forward flux sampling and mean first passage times
Authors: Thapar Vikram , Escobedo Fernando A.
Published: December 2015

In this work, a method is proposed to simultaneously compute the transition rate constant and the free energy profile of a rare event along an order parameter connecting two well-defined regions of phase space. The method employs a forward flux sampling technique in combination with a mean first passage time approach to estimate the steady state probability and mean first passage times. These quantities are fitted to a Markovian model that allows the estimation of the free energy along the chosen order parameter. The proposed technique is first validated with two test systems (an Ising model and a model potential energy surface) and then used to study the solid-phase homogeneous nucleation of selected polyhedral particles.
Microtearing turbulence: Magnetic braiding and disruption limit
Authors: Firpo Marie-Christine
Published: December 2015

A realistic reduced model involving a large poloidal spectrum of microtearing modes is used to probe the existence of some stochasticity of magnetic field lines. Stochasticity is shown to occur even for the low values of the magnetic perturbation δB/B devoted to magnetic turbulence that have been experimentally measured. Because the diffusion coefficient may strongly depend on the radial (or magnetic-flux) coordinate, being very low near some resonant surfaces, and because its evaluation implicitly makes a normal diffusion hypothesis, one turns to another indicator appropriate to diagnose the confinement: the mean residence time of magnetic field lines. Their computation in the microturbulence frame points to the existence of a disruption limit, namely of a critical order of magnitude of δB/B above which stochasticity is no longer benign yet, leads to a macroscopic loss of confinement in some tens to hundred of electron toroidal excursions. Since the level of magnetic turbulence δB/B has been measured to grow with the plasma electron density, this would also be a density limit.
Determination of deuterium–tritium critical burn-up parameter by four temperature theory
Authors: Nazirzadeh M. , Ghasemizad A. , Khanbabei B.
Published: December 2015

Conditions for thermonuclear burn-up of an equimolar mixture of deuterium-tritium in non-equilibrium plasma have been investigated by four temperature theory. The photon distribution shape significantly affects the nature of thermonuclear burn. In three temperature model, the photon distribution is Planckian but in four temperature theory the photon distribution has a pure Planck form below a certain cut-off energy and then for photon energy above this cut-off energy makes a transition to Bose-Einstein distribution with a finite chemical potential. The objective was to develop four temperature theory in a plasma to calculate the critical burn up parameter which depends upon initial density, the plasma components initial temperatures, and hot spot size. All the obtained results from four temperature theory model are compared with 3 temperature model. It is shown that the values of critical burn-up parameter calculated by four temperature theory are smaller than those of three temperature model.
Fast excitation of geodesic acoustic mode by energetic particle beams
Authors: Cao Jintao , Qiu Zhiyong , Zonca Fulvio
Published: December 2015

A new mechanism for geodesic acoustic mode (GAM) excitation by a not fully slowed down energetic particle (EP) beam is analyzed to explain experimental observations in Large Helical Device. It is shown that the positive velocity space gradient near the lower-energy end of the EP distribution function can strongly drive the GAM unstable. The new features of this EP-induced GAM (EGAM) are: (1) no instability threshold in the pitch angle; (2) the EGAM frequency can be higher than the local GAM frequency; and (3) the instability growth rate is much larger than that driven by a fully slowed down EP beam.
Equivalent circuit for VO2 phase change material film in reconfigurable frequency selective surfaces
Authors: Sanphuang Varittha , Ghalichechian Nima , Nahar Niru K. , Volakis John L.
Published: December 2015

We developed equivalent circuits of phase change materials based on vanadium dioxide (VO2) thin films. These circuits are used to model VO2 thin films for reconfigurable frequency selective surfaces (FSSs). This is important as it provides a way for designing complex structures. A reconfigurable FSS filter using VO2 ON/OFF switches is designed demonstrating −60 dB isolation between the states. This filter is used to provide the transmission and reflection responses of the FSS in the frequency range of 0.1–0.6 THz. The comparison between equivalent circuit and full-wave simulation shows excellent agreement.
Computational modeling of the effect of external electron injection into a direct-current microdischarge
Authors: Panneer Chelvam Prem Kumar , Raja Laxminarayan L.
Published: December 2015

Electron emission from the electrode surface plays an important role in determining the structure of a direct-current microdischarge. Here we have developed a computational model of a direct-current microdischarge to study the effect of external electron injection from the cathode surface into the discharge to manipulate its properties. The model provides a self-consistent, multi-species, multi-temperature fluid representation of the plasma. A microdischarge with a metal-insulator-metal configuration is chosen for this study. The effect of external electron injection on the structure and properties of the microdischarge is described. The transient behavior of the microdischarge during the electron injection is examined. The nonlinearities in the dynamics of the plasma result in a large increase of conduction current after active electron injection. For the conditions simulated a switching time of ∼100 ns from a low-current to high-current discharge state is realized.
Quantum key distribution with an entangled light emitting diode
Authors: Dzurnak B. , Stevenson R. M. , Nilsson J. , Dynes J. F. , Yuan Z. L. , Skiba-Szymanska J. , Farrer I. , Ritchie D. A. , Shields A. J.
Published: December 2015

Measurements performed on entangled photon pairs shared between two parties can allow unique quantum cryptographic keys to be formed, creating secure links between users. An advantage of using such entangled photon links is that they can be adapted to propagate entanglement to end users of quantum networks with only untrusted nodes. However, demonstrations of quantum key distribution with entangled photons have so far relied on sources optically excited with lasers. Here, we realize a quantum cryptography system based on an electrically driven entangled-light-emitting diode. Measurement bases are passively chosen and we show formation of an error-free quantum key. Our measurements also simultaneously reveal Bell's parameter for the detected light, which exceeds the threshold for quantum entanglement.
Edge localized mode characteristics during edge localized mode mitigation by supersonic molecular beam injection in Korea Superconducting Tokamak Advanced Research
Authors: Lee H. Y. , Hahn S. H. , Ghim Y.-C. , Bak J. G. , Lee J. H. , Ko W. H. , Lee K. D. , Lee S. H. , Lee H. H. , Juhn J.-W. , Kim H. S. , Yoon S. W. , Han H. , Hong J. H. , Jang J. H. , Park J. S. , Choe Wonho
Published: December 2015

It has been reported that supersonic molecular beam injection (SMBI) is an effective means of edge localized mode (ELM) mitigation. This paper newly reports the changes in the ELM, plasma profiles, and fluctuation characteristics during ELM mitigation by SMBI in Korea Superconducting Tokamak Advanced Research. During the mitigated ELM phase, the ELM frequency increased by a factor of 2–3 and the ELM size, which was estimated from the Dα amplitude, the fractional changes in the plasma-stored energy and the line-averaged electron density, and divertor heat flux during an ELM burst, decreased by a factor of 0.34–0.43. Reductions in the electron and ion temperatures rather than in the electron density were observed during the mitigated ELM phase. In the natural ELM phase, frequency chirping of the plasma fluctuations was observed before the ELM bursts; however, the ELM bursts occurred without changes in the plasma fluctuation frequency in the mitigated ELM phase.
Surface waves on quantum plasma half-space with electron exchange-correlation effects
Authors: Khalilpour H.
Published: December 2015

The propagation of surface waves on a quantum plasma half-space is investigated, taking into account the electron exchange-correlation effect. Using the modified quantum hydrodynamic model in conjunction with the Poisson equation, the dispersion relation of surface waves is obtained. It is found that due to the presence of electron exchange-correlation effect the wave frequency is shifted to lower frequencies. For different ranges of Brueckner parameter rs, the effect of electron exchange-correlation is investigated. It is indicated that for weak coupling region with rs < 0.1, the wave frequency remains unchanged and in this region the effect of electron exchange-correlation is negligible. For moderate coupling region, i.e., (0.1 < rs < 1), the influence of electron exchange-correlation is important and as rs increases, the electron exchange-correlation effect also increases.
Skyrmion based microwave detectors and harvesting
Authors: Finocchio G. , Ricci M. , Tomasello R. , Giordano A. , Lanuzza M. , Puliafito V. , Burrascano P. , Azzerboni B. , Carpentieri M.
Published: December 2015

Magnetic skyrmions are topologically protected states that are very promising for the design of the next generation of ultra-low-power electronic devices. In this letter, we propose a magnetic tunnel junction based spin-transfer torque diode with a magnetic skyrmion as ground state and a perpendicular polarizer patterned as nano-contact for a local injection of the current. The key result is the possibility to achieve sensitivities (i.e., detection voltage over input microwave power) larger than 2000 V/W for optimized contact diameters. We also pointed out that large enough voltage controlled magnetocrystalline anisotropy could significantly improve the sensitivity. Our results can be very useful for the identification of a class of spin-torque diodes with a non-uniform ground state and to understand the fundamental physics of the skyrmion dynamical properties.