bluuebunny/crossref_metadata_2025 huggingface dataset:
Dichlorosilane-derived nano-silicon inside hollow carbon spheres as a high-performance anode for Li-ion batteries
Authors: Jaumann Tony , Gerwig Maik , Balach Juan , Oswald Steffen , Brendler Erica , Hauser Ralf , Kieback Bernd , Eckert Jürgen , Giebeler Lars , Kroke Edwin
Published: March 2017

A scalable synthesis for a large amount of silicon nanoparticles (<10 nm) embedded within hollow carbon spheres as a high-performance anode for Li-ion batteries.
Remarkable supercapacitor performance of petal-like LDHs vertically grown on graphene/polypyrrole nanoflakes
Authors: Du Dongfeng , Wu Xiaozhong , Li Shuo , Zhang Yu , Xing Wei , Li Li , Xue Qingzhong , Bai Peng , Yan Zifeng
Published: March 2017

A novel 3D graphene@polypyrrole@LDH composite exhibited a large specific capacitance, excellent rate performance and outstanding cycling stability.
A green and robust solid catalyst facilitating the magnesium sulfite oxidation in the magnesia desulfurization process
Authors: Wang Lidong , Qi Tieyue , Wu Siyu , Zhang Shihan , Qi Dan , Xiao Huining
Published: March 2017

Effect of cobalt loading on the dispersity and catalysis performance.
Molecular engineering of face-on oriented dopant-free hole transporting material for perovskite solar cells with 19% PCE
Authors: Rakstys Kasparas , Paek Sanghyun , Gao Peng , Gratia Paul , Marszalek Tomasz , Grancini Giulia , Cho Kyung Taek , Genevicius Kristijonas , Jankauskas Vygintas , Pisula Wojciech , Nazeeruddin Mohammad Khaja
Published: March 2017

Dopant-free HTM KR321 showed highly ordered characteristic face-on organization leading to increased vertical charge transport and PCE over 19% in PSC with improved stability.
pH dependent photocatalytic hydrogen evolution by self-assembled perylene bisimides
Authors: Nolan Michael C. , Walsh James J. , Mears Laura L. E. , Draper Emily R. , Wallace Matthew , Barrow Michael , Dietrich Bart , King Stephen M. , Cowan Alexander J. , Adams Dave J.
Published: March 2017

We show the importance of the self-assembly of a perylene bisimide on its photocatalytic activity.
A developmental toxicity assay of Carpesii Fructus on zebrafish embryos/larvae
Authors: Xia Qing , Luo Jun , Mei Xue , Wang Yutong , Huang Wanzhen , Wang Jinfeng , Yang Ranran , Ma Zhiqiang , Lin Ruichao
Published: March 2017

Carpesii Fructus, the dried fruit ofCarpesium abrotanoidesL., has been used as a traditional Chinese medicine for centuries to kill intestinal parasites in children.
Size‐reduced dual‐band HMSIW cavity filters loaded with double‐sided SICSRRs
Authors: Huang Yong Mao , Peng Yujia , Zhou Yuliang , Jin Haiyan , Leng Supeng , Wang Guoan
Published: March 2017

Two size‐reduced dual‐band half‐mode substrate integrated waveguide (HMSIW) cavity filters double‐side‐loaded with the conventional and stepped‐impedance complementary split‐ring resonators (SICSRRs) are presented. The SICSRR can exhibit larger equivalent electrical length than the conventional CSRR and thus provides a method to implement size‐miniaturisation. By loading both CSRR and SICSRR into the two sides of the HMSIW cavity, a dual‐band resonator is formed. Since sizes of the CSRR and SICSRR on the two sides are controlled independently, the two passbands of the proposed resonator can be tuned flexibly. With the proposed HMSIW–DS–SICSRR cavity resonators, two dual‐band filters are realised. Compared to other dual‐band SIW filters, the two proposed dual‐band filters can achieve sized‐reduction about 48.5 and 50%, with the measured results in good agreement with the simulated ones.
Design and experimental validation of dual‐band circularly polarised horn filtenna
Authors: Barbuto M. , Trotta F. , Bilotti F. , Toscano A.
Published: March 2017

A simple and cheap solution is proposed to transform a wideband and linearly polarised horn antenna in a dual‐band circularly polarised horn filtenna. The filtering and polarisation transformation capabilities are achieved by inserting inside the throat of the horn a complementary electrically small resonator etched on a thin metallic sheet. In this way, the overall structure is well matched in two frequency ranges (13–14 and 16.4–17 GHz) and radiates left‐handed and right‐handed circularly polarised fields in the lower and upper frequency bands, respectively. The measurements performed on a realised prototype confirm the good performance of the proposed structure, which may be employed in satellite communication systems requiring different circular polarisation for the up‐ and down‐link frequency ranges.
Robust harmonic detection, classification and compensation method for electric drives based on the sparse fast Fourier transform and the Mahalanobis distance
Authors: Peretti Luca , Pathmanathan Mehanathan , Ikram ul Haq Omer , Sahoo Subrat
Published: March 2017

This work presents a method for the robust detection, classification and possible compensation of harmonics in electric drives during real‐time operation, with the aim of providing a framework for monitoring and diagnostic without the need of additional hardware. The detection is performed with a sparse fast Fourier transform algorithm, for its lower computational effort when the signals are sparse (which, by definition, contain few meaningful spectral lines). The classification is performed on the results of the signal frequency analysis by means of the Mahalanobis distance concept, improving the robustness and noise rejection properties of the method. The compensation part relies on a family of regulators in parallel, each operating in the rotating reference frame of the harmonic to be cancelled. The theoretical background is followed by a discussion on the implementation and the interaction of the three blocks for a successful real‐time operation. The system was tested in laboratory and proved to fulfil the requirements, by running in parallel to a vector control for synchronous machines. It was also found that the method is a useful tool to determine the presence of unknown harmonics in an electric drive system, thus potentially providing early warnings of unexpected failures.
Development of a novel 20 kV 0.1 Hz very low frequency cosine‐rectangular voltage generator for multi‐functional insulation testing of MV power cables
Authors: Hou Zhe , Li Hongjie , Chen Shuo , Li Baojie , Lu Yuxin , Ji Shengchang
Published: March 2017

This study covers research and development efforts to develop, design and test a novel very low frequency cosine‐rectangular voltage generator (CRVG) specialised not only for a withstand test, but also a partial discharge (PD) test of standard medium voltage (MV) cross‐linked polyethylene power cables. The system schematic and operating principle of the proposed system are presented and described. The cosinusoidal polarity reversing process is realised through L –C series resonance. A charging and discharging switch is developed by means of an insulated gate bipolar transistor series‐connected semiconductor switch. A laboratory prototype is assembled and tested. Maximum output voltage of the proposed CRVG is measured as 20 kV, which is in accordance with the expected acceptance test voltage level given in IEEE standard 400.2. Finally, the proposed system is applied to PD detection of a 300 m cable circuit with a built‐in artificial defect, and the PD locating results are presented, proving the system's feasibility.
SSCI performance of DFIG with direct controller
Authors: Wang Liang , Peng Jingyu , You Yuyang , Ma Hongwei
Published: March 2017

Mathematical analysis indicates that stator output power of doubly fed induction generator (DFIG) could be directly controlled by the output voltage of rotor‐side converter (RSC). Thus, a direct stator‐power controller (DPC) could be induced. Furthermore, rotor speed can be directly controlled by RSC with direct rotor‐speed controller (DSC). When the rotor speed is selected as a feedback of RSC controller, the equivalent impedance of RSC could be decreased sharply. Under this condition, DFIG will supply little energy for series resonance caused by fixed series compensation. This results in that DFIG with DSC is insusceptible to subsynchronous control interaction (SSCI). Updating DLP into DSC could be selected as a solution of existing SSCI. Eigenvalue analysis and time‐domain simulations prove the effectiveness of DSC in mitigating SSCI.
Hybrid NSS features for no‐reference image quality assessment
Authors: Qin Min , Lv Xiaoxin , Chen Xiaohui , Wang Weidong
Published: March 2017

A novel general‐purpose no‐reference image quality assessment (NR‐IQA) model utilising hybrid natural scene statistics (HNSS) is proposed. Distinguished from existing NR‐IQA approaches, the new model combines the statistics of locally mean subtracted and contrast normalised coefficients in the spatial domain and the statistics of image patch coefficients in a codebook space, which is constructed by codebooks extracted from pristine images using K‐Means. The authors demonstrate that the coefficients in the codebook space keep the NSS characteristics as same as these in the spatial domain. After extracting the statistical features, a two‐stage framework of distortion classification followed by quality assessment is applied. Experimental results show that the authors’ predicted quality score well matches human perceptual image quality. The proposed model outperforms state‐of‐the‐art general‐purpose NR‐IQA approaches when it is tested on the LIVE database.
Performance and design analysis of an improved non‐isolated multiple input buck DC–DC converter
Authors: Varesi Kazem , Hosseini Seyed Hossein , Sabahi Mehran , Babaei Ebrahim , Vosoughi Naser
Published: March 2017

This study proposes an improved non‐isolated single‐inductor multiple‐input buck DC–DC converter, with reduced number of components. Less component count can reduce the size, mass and cost of converter. Simultaneous or independent power transfer capability has been provided for input sources. The bidirectional power flow capability has also been provided through usage of a battery without any additional switches. This makes the topology very suitable for hybrid energy systems or hybrid electric vehicle/electric vehicle applications. Different operational modes of proposed topology have been presented. Then, a generalised relationship has been proposed for calculation of critical inductance (as an important design parameter) of proposed n‐input buck topology. To make a better judgement, the proposed topology has been compared with recently presented novel topologies. Also, a simple proportional–integral based controller has been applied to regulate output voltage and assign the portion of power that each input source should provide. To confirm the validity of proposed topology and theoretical concepts, the three‐input version has been modelled and simulated in PSCAD/EMTDC software and implemented experimentally. Simulation and experimental results validate proper performance of proposed topology.
Simultaneous data collection of small maritime targets using multistatic radar and forward scatter radar
Authors: Ritchie Matthew , Fioranelli Francesco , Woodbridge Karl , Griffiths Hugh , Daniel Liam , De Luca Alessandro , Hristov Stanislav , Gashinova Marina , Cherniakov Mikhail
Published: March 2017

Radar detection of small maritime targets is of great interest in the context of coastal and port security for prevention of activities such as smuggling and piracy. Multistatic radar and forward scatter radar offer detection advantages compared with conventional monostatic systems, such as advantageous multi‐perspective target view for the former and target radar cross‐section enhancement for the latter. In this study, experimental results are presented to characterise simultaneous measurements investigating the detection of a small inflatable boat by a multistatic radar and a forward scatter radar. These results are believed to be the first example of simultaneous experimental comparison of such systems.
Asteroseismology of the exoplanet-host F-type star 94 Ceti: Impact of atomic diffusion on the stellar parameters
Authors: Deal M. , Escobar M. E. , Vauclair S. , Vauclair G. , Hui-Bon-Hoa A. , Richard O.
Published: March 2017

Context.A precision of the order of one percent is needed on the parameters of exoplanet-hosts stars to correctly characterise the planets themselves. This can be achieved by asteroseismology. It is important in this context to test the influence of introducing atomic diffusion with radiative accelerations in the models upon the derived parameters. In this paper, we begin this study with the case of the star 94 Ceti A.

Aims.We aim to perform a complete asteroseismic analysis of the exoplanet-host F-type star 94 Ceti A, from the first radial-velocity observations with the High Accuracy Radial velocity Planet Searcher (HARPS) up to the final computed best models. We also aim to test the influence of atomic diffusion, including radiative accelerations, upon the computed frequencies and on the determined stellar parameters. 94 Ceti A is hot enough to suffer these effects. We also aim to test the effect of including a complete atmosphere in the stellar models.

Methods.The radial velocity observations were performed with HARPS in 2007. The low degree modes were derived and identified using classical methods and compared with the results obtained from stellar models computed with the Toulouse Geneva Evolution Code (TGEC).

Results.We obtained precise parameters for the star 94 Ceti A. We showed that including atomic diffusion with radiative accelerations can modify the age by a few percent, whereas adding a complete atmosphere does not change the results by more than one percent.

Conclusions.Atomic diffusion including radiative accelerations should be taken into account in all the computations of stellar models with masses larger than 1.3M⊙in order to determine accurate parameters for observed stars.
A Simple Technique to Prevent Early or Late EndoButton Deployment in Anterior Cruciate Ligament Reconstructions: A Technical Note
Authors: Salim Rodrigo , Kfuri Mauricio , Fogagnolo Fabricio
Published: March 2017

The use of suspensory graft fixation methods in arthroscopic reconstruction of the anterior cruciate ligament has become increasingly popular with the more frequent use of tendon grafts and anatomical techniques involving the creation of bone tunnels. An important technical step to ensure adequate fixation of the graft when using EndoButton-type implants, particularly in the femur, involves flipping the EndoButton plate at the correct length to avoid performing this maneuver before the appropriate time or leaving soft tissue between the plate and lateral cortex of the femur. In the present study, we describe a simple arthroscopic technique for indicating the correct time to flip/deploy the EndoButton plate.
Coronary Artery Bypass Surgery in Diffuse Advanced Coronary Artery Disease: 1-Year Clinical and Angiographic Results
Authors: Bittencourt Marcio , Pereira Alexandre , Poppi Nilson , Dallan Luis , Krieger José , Cesar Luiz , Gowdak Luís , Dourado Luciana
Published: March 2017

Background Proper treatment of patients with diffuse, severe coronary artery disease (CAD) is a challenge due to its complexity. Thus, data on the outcomes after coronary artery bypass graft (CABG) in this population is scarce. In this study, we aimed to determine the impact of CABG on the clinical and functional status, as well as graft patency in those individuals.

Methods Patients with severe and diffuse CAD who underwent incomplete CABG due to complex anatomy or extensive distal coronary involvement were evaluated preoperatively and 1 year after surgery. Postoperative coronary angiography was performed to evaluate graft patency. Graft occlusion was defined as the complete absence of opacification of the target vessel. Stratified analysis of graft occlusion was performed by graft type and territories, defined as left anterior descending artery (LAD), the left circumflex branch, and the right coronary artery territories; the latter two, grouped, were further classified as non-LAD territory.

Results A total of 57 patients were included, in whom 131 grafts were placed. There was a significant improvement in Canadian Cardiovascular Society angina symptom severity (Z = –6.1; p < 0.001) and maximum oxygen uptake (p < 0.001), with a corresponding decrease in the use of long-acting nitrates (p < 0.001). The overall graft occlusion rate was 19.1%, with no significant difference between LAD and non-LAD territories (p = 0.08). However, a significantly lower occlusion rate was noted for the internal mammary artery (IMA) grafts when compared with saphenous vein grafts (p = 0.01), though this difference was only significant in the LAD territory (p = 0.04). Overall, the use of venous graft was the only predictor occlusion at 1 year (odds ratio: 4.03; p = 0.016).

Conclusion In patients with diffuse CAD, incomplete CABG surgery resulted in a significant clinical improvement, with acceptable graft occlusion rates at 1 year, particularly for IMA grafts to the LAD territory.
Helmet Wear and Craniofacial Trauma Burden: A Plea for Regulations Mandating Protective Helmet Wear
Authors: Harvey Jamison Anne , Gibreel Waleed , Charafeddine Ali , Sharaf Basel
Published: March 2017

Helmet wear offers protection in various ways against craniomaxillofacial and brain trauma. The specific pattern and overall burden of craniofacial trauma among helmeted and unhelmeted patients has not been well defined.

This is a retrospective review of trauma patients involved in documented helmet-associated injuries that presented to the Mayo Clinic Emergency Department in Rochester, Minnesota, and completed initial trauma evaluation between 1999 and 2015.

A total of 417 patients (50% unhelmeted, 82% male) were identified. The median age at injury was 22.9 years (interquartile range [IQR]: 15.2–44.2]) and median follow-up was 26 months ([IQR: 2.2–64.8]). The majority of injuries involved motorcycle accidents (57.6%), bicycles (30.2%), and other modes of injury (12.7%). The mean Glasgow Coma Score (GSC) at the time of presentation was 14.2 (SD ± 2.4) and mean injury severity score (ISS) was 10.2 (SD ± 7.5). Motorcycle accidents had a higher mean ISS compared with other modes of injury ( p = 0.048). Unhelmeted patients were more likely to sustain scalp lacerations ( p < 0.0001), facial bone fractures ( p = 0.01), scalp hematomas ( p = 0.041), skull fractures ( p = 0.017), and are more likely to require hospital admission ( p = 0.0003). Unhelmeted patients’ hospital length of stay was on average 2 days longer than helmeted patients’ stay ( p = 0.0721). Unhelmeted patients were more likely to require out-of-home placement than helmeted patients.

Among trauma patients, helmet use was associated with less scalp lacerations and hematomas, facial bones fractures, skull fractures, and need for hospital admission. Adoption of legislation and regulations mandating protective helmet use in all states are strongly encouraged to minimize the burden of craniofacial injuries among unhelmeted patients.
Photorezeptortransplantation in die degenerative Netzhaut
Authors: Borsch O. , Santos-Ferreira T. , Ader M.
Published: March 2017

Sehbeeinträchtigungen und Erblindung aufgrund des Verlusts von Photorezeptoren stellen einen der Hauptgründe für Behinderungen in industrialisierten Gesellschaften dar. Während Stäbchenphotorezeptoren Seheindrücke unter schwachen Lichtverhältnissen vermitteln, liefern Zapfenphotorezeptoren fokussierte visuelle Eindrücke bei Tageslicht und erlauben die Wahrnehmung von Farben. Verschiedene therapeutische Strategien, zu denen auch zellbasierte Interventionen zählen, werden derzeit zur Behandlung eines Sehverlusts entwickelt. Während der letzten Dekade konnten große Fortschritte im Ersatz von Photorezeptoren in vorklinischen Tiermodellen erzielt werden. Dies beinhaltete die Klärung notwendiger Voraussetzungen, wie dem optimalen ontogenetischen Stadium für transplantierbare Photorezeptoren, zellspezifische Anreicherungsmethoden und robuste Transplantationstechniken. Außerdem konnten erste Studien Hinweise auf funktionale Verbesserungen nach Photorezeptortransplantation in Mausmodelle mit retinaler Dysfunktion liefern. Des Weiteren erlauben bedeutende Fortschritte in der Zellkulturtechnik die Generierung von photorezeptorenthaltenden retinalen Organoiden, die aus pluripotenten Stammzellen gewonnen werden und eine theoretisch unbegrenzte Quelle zur Produktion von Photorezeptortransplantaten darstellen. Interessanterweise könnte der kürzlich beschriebene Transfer von zytoplasmatischem Material zwischen Spender- und Empfängerphotorezeptoren eine weitere Behandlungsoption für Ansätze zur Zelltransplantation darstellen. In dieser Übersicht fokussieren wir uns auf die wichtigsten Entwicklungen innerhalb des Feldes der Photorezeptortransplantation, wobei wir Fortschritte, Herausforderungen und Hürden zur Entwicklung von Photorezeptortransplantationen hin zu klinischen Anwendungen diskutieren.
The effects of core-level broadening in determining band alignment at the epitaxial SrTiO3(001)/p-Ge(001) heterojunction
Authors: Chambers Scott A. , Du Yingge , Comes Ryan B. , Spurgeon Steven R. , Sushko Peter V.
Published: March 2017

Chemical effects at the surface and interface can broaden core-level spectra in X-ray photoemission for thin-film heterojunctions, as can electronic charge redistributions. We explore these effects and their influence on the measurement of valence and conduction band offsets at the epitaxial SrTiO3(001)/p-Ge(001) heterojunction. We observe a clear broadening in Ge 3d and Sr 3d core-level X-ray photoelectron spectra relative to those of clean, bulk Ge(001), and homoepitaxial SrTiO3(001), respectively. Angle-resolved measurements indicate that this broadening is driven primarily by chemical shifts associated with surface hydroxylation, with built-in potentials playing only a minor role. The impact of these two interpretations on the valence band offset is significant on the scale of transport energetics, amounting to a difference of 0.2 eV.
Small-world bias of correlation networks: From brain to climate
Authors: Hlinka Jaroslav , Hartman David , Jajcay Nikola , Tomeček David , Tintěra Jaroslav , Paluš Milan
Published: March 2017

Complex systems are commonly characterized by the properties of their graph representation. Dynamical complex systems are then typically represented by a graph of temporal dependencies between time series of state variables of their subunits. It has been shown recently that graphs constructed in this way tend to have relatively clustered structure, potentially leading to spurious detection of small-world properties even in the case of systems with no or randomly distributed true interactions. However, the strength of this bias depends heavily on a range of parameters and its relevance for real-world data has not yet been established. In this work, we assess the relevance of the bias using two examples of multivariate time series recorded in natural complex systems. The first is the time series of local brain activity as measured by functional magnetic resonance imaging in resting healthy human subjects, and the second is the time series of average monthly surface air temperature coming from a large reanalysis of climatological data over the period 1948–2012. In both cases, the clustering in the thresholded correlation graph is substantially higher compared with a realization of a density-matched random graph, while the shortest paths are relatively short, showing thus distinguishing features of small-world structure. However, comparable or even stronger small-world properties were reproduced in correlation graphs of model processes with randomly scrambled interconnections. This suggests that the small-world properties of the correlation matrices of these real-world systems indeed do not reflect genuinely the properties of the underlying interaction structure, but rather result from the inherent properties of correlation matrix.
An observer for an occluded reaction-diffusion system with spatially varying parameters
Authors: Kramer Sean , Bollt Erik M.
Published: March 2017

Spatially dependent parameters of a two-component chaotic reaction-diffusion partial differential equation (PDE) model describing ocean ecology are observed by sampling a single species. We estimate the model parameters and the other species in the system by autosynchronization, where quantities of interest are evolved according to misfit between model and observations, to only partially observed data. Our motivating example comes from oceanic ecology as viewed by remote sensing data, but where noisy occluded data are realized in the form of cloud cover. We demonstrate a method to learn a large-scale coupled synchronizing system that represents the spatio-temporal dynamics and apply a network approach to analyze manifold stability.
On the degenerate soliton solutions of the focusing nonlinear Schrödinger equation
Authors: Li Sitai , Biondini Gino , Schiebold Cornelia
Published: March 2017

We characterize the N-soliton solutions of the focusing nonlinear Schrödinger (NLS) equation with degenerate velocities, i.e., solutions in which two or more soliton velocities are the same, which are obtained when two or more discrete eigenvalues of the scattering problem have the same real parts. We do so by employing the operator formalism developed by one of the authors to express the N-soliton solution of the NLS equation in a convenient form. First we analyze soliton solutions with fully degenerate velocities (a so-called multi-soliton group), clarifying their dependence on the soliton parameters. We then consider the dynamics of soliton groups interaction in a general N-soliton solution. We compute the long-time asymptotics of the solution and we quantify the interaction-induced position and phase shifts of each non-degenerate soliton as well as the interaction-induced changes in the center of mass and soliton parameters of each soliton group.
Modeling micelle formation and interfacial properties with iSAFT classical density functional theory
Authors: Wang Le , Haghmoradi Amin , Liu Jinlu , Xi Shun , Hirasaki George J. , Miller Clarence A. , Chapman Walter G.
Published: March 2017

Surfactants reduce the interfacial tension between phases, making them an important additive in a number of industrial and commercial applications from enhanced oil recovery to personal care products (e.g., shampoo and detergents). To help obtain a better understanding of the dependence of surfactant properties on molecular structure, a classical density functional theory, also known as interfacial statistical associating fluid theory, has been applied to study the effects of surfactant architecture on micelle formation and interfacial properties for model nonionic surfactant/water/oil systems. In this approach, hydrogen bonding is explicitly included. To minimize the free energy, the system minimizes interactions between hydrophobic components and hydrophilic components with water molecules hydrating the surfactant head group. The theory predicts micellar structure, effects of surfactant architecture on critical micelle concentration, aggregation number, and interfacial tension isotherm of surfactant/water systems in qualitative agreement with experimental data. Furthermore, this model is applied to study swollen micelles and reverse swollen micelles that are necessary to understand the formation of a middle-phase microemulsion.
Dependence of intrinsic torque and momentum confinement on normalized gyroradius and collisionality in the DIII-D tokamak
Authors: Chrystal C. , Grierson B. A. , Solomon W. M. , Tala T. , deGrassie J. S. , Petty C. C. , Salmi A. , Burrell K. H.
Published: March 2017

The dependence of intrinsic torque and momentum confinement time on normalized gyroradius (ρ*) and collisionality (ν*) has been measured in the DIII-D tokamak. The intrinsic torque normalized to temperature is found to have ρ* and ν* dependencies of ρ*−1.5±0.8 and ν*0.26±0.04. This dependence on ρ* is unexpectedly favorable (increasing as ρ* decreases). The choice of normalization is important, and the implications are discussed. The unexpected dependence on ρ* is found to be robust, despite some uncertainty in the choice of normalization. The dependence of momentum confinement on ρ* does not clearly demonstrate Bohm or gyro-Bohm like scaling, and a weaker dependence on ν* is found. The calculations required to use these dependencies to determine the intrinsic torque in future tokamaks such as ITER are presented, and the importance of the normalization is explained. Based on the currently available information, the intrinsic torque predicted for ITER is 33 N m, comparable to the expected torque available from neutral beam injection. The expected average intrinsic rotation associated with this intrinsic torque is small compared to current tokamaks, but it may still aid stability and performance in ITER.
Multiscale modeling of a rectifying bipolar nanopore: Comparing Poisson-Nernst-Planck to Monte Carlo
Authors: Matejczyk Bartłomiej , Valiskó Mónika , Wolfram Marie-Therese , Pietschmann Jan-Frederik , Boda Dezső
Published: March 2017

In the framework of a multiscale modeling approach, we present a systematic study of a bipolar rectifying nanopore using a continuum and a particle simulation method. The common ground in the two methods is the application of the Nernst-Planck (NP) equation to compute ion transport in the framework of the implicit-water electrolyte model. The difference is that the Poisson-Boltzmann theory is used in the Poisson-Nernst-Planck (PNP) approach, while the Local Equilibrium Monte Carlo (LEMC) method is used in the particle simulation approach (NP+LEMC) to relate the concentration profile to the electrochemical potential profile. Since we consider a bipolar pore which is short and narrow, we perform simulations using two-dimensional PNP. In addition, results of a non-linear version of PNP that takes crowding of ions into account are shown. We observe that the mean field approximation applied in PNP is appropriate to reproduce the basic behavior of the bipolar nanopore (e.g., rectification) for varying parameters of the system (voltage, surface charge, electrolyte concentration, and pore radius). We present current data that characterize the nanopore’s behavior as a device, as well as concentration, electrical potential, and electrochemical potential profiles.
Collisional considerations in axial-collection plasma mass filters
Authors: Ochs I. E. , Gueroult R. , Fisch N. J. , Zweben S. J.
Published: March 2017

The chemical inhomogeneity of nuclear waste makes chemical separations difficult, while the correlation between radioactivity and nuclear mass makes mass-based separation, and in particular plasma-based separation, an attractive alternative. Here, we examine a particular class of plasma mass filters, namely filters in which (a) species of different masses are collected along magnetic field lines at opposite ends of an open-field-line plasma device and (b) gyro-drift effects are important for the separation process. Using an idealized cylindrical model, we derive a set of dimensionless parameters which provide minimum necessary conditions for an effective mass filter function in the presence of ion-ion and ion-neutral collisions. Through simulations of the constant-density profile, turbulence-free devices, we find that these parameters accurately describe the mass filter performance in more general magnetic geometries. We then use these parameters to study the design and upgrade of current experiments, as well as to derive general scalings for the throughput of production mass filters. Importantly, we find that ion temperatures above 3 eV and magnetic fields above 104 G are critical to ensure a feasible mass filter function when operating at an ion density of 1013 cm–3.
Analytic second nuclear derivatives of Hartree-Fock and DFT using multi-resolution analysis
Authors: Bischoff Florian A.
Published: March 2017

We present the formalism, implementation, and numerical results for the computation of second derivatives with respect to nuclear displacements of molecules in the formalism of multi-resolution analysis. The highly singular nuclear potentials are partially regularized to improve the numerical stability. Vibrational frequencies are well reproduced to within an RMS of a few cm−1 compared to large basis set LCAO (linear combination of atomic orbitals) calculations. Intermolecular modes, hindered rotations, and heavy atoms may lead to loss of precision. Tight precision thresholds are therefore necessary to converge to numerically stable results.
Finite-temperature time-dependent variation with multiple Davydov states
Authors: Wang Lu , Fujihashi Yuta , Chen Lipeng , Zhao Yang
Published: March 2017

The Dirac-Frenkel time-dependent variational approach with Davydov Ansätze is a sophisticated, yet efficient technique to obtain an accurate solution to many-body Schrödinger equations for energy and charge transfer dynamics in molecular aggregates and light-harvesting complexes. We extend this variational approach to finite temperature dynamics of the spin-boson model by adopting a Monte Carlo importance sampling method. In order to demonstrate the applicability of this approach, we compare calculated real-time quantum dynamics of the spin-boson model with that from numerically exact iterative quasiadiabatic propagator path integral (QUAPI) technique. The comparison shows that our variational approach with the single Davydov Ansätze is in excellent agreement with the QUAPI method at high temperatures, while the two differ at low temperatures. Accuracy in dynamics calculations employing a multitude of Davydov trial states is found to improve substantially over the single Davydov Ansatz, especially at low temperatures. At a moderate computational cost, our variational approach with the multiple Davydov Ansatz is shown to provide accurate spin-boson dynamics over a wide range of temperatures and bath spectral densities.
Calculating transition rates from durations of transition paths
Authors: Zhu Fangqiang
Published: March 2017

Calculating the kinetic rates for rare transitions is an important objective for molecular simulations. Here I prove equalities that relate the transition rates to the equilibrium free energy and the statistics of the transition paths. In particular, the durations of the transition paths within given intervals of the reaction coordinate provide the kinetic pre-factor in the rate formula. Based on the available free energy, the transition rates can further be rigorously calculated by initiating forward and backward simulations and evaluating the duration of each transition path. Validation on a model system confirms that the approach correctly predicts the transition rates from the simulations and demonstrates that whereas the relations here are general and valid for any chosen reaction coordinate, a good reaction coordinate will enable a more efficient sampling of the transition paths and thus a more reliable rate calculation.
Demonstration of a long pulse X-ray source at the National Ignition Facility
Authors: May M. J. , Opachich Y. P. , Kemp G. E. , Colvin J. D. , Barrios M. A. , Widmann K. W. , Fournier K. B. , Hohenberger M. , Albert F. , Regan S. P.
Published: March 2017

A long duration high fluence x-ray source has been developed at the National Ignition Facility (NIF). The target was a 14.4 mm tall, 4.1 mm diameter, epoxy walled, gas filled pipe. Approximately 1.34 MJ from the NIF laser was used to heat the mixture of (55:45) Kr:Xe at 1.2 atm (∼5.59 mg/cm3) to emit in a fairly isotropic radiant intensity of 400–600 GW/sr from the Ephoton = 3–7 keV spectral range for a duration of ≈ 14 ns. The HYDRA simulated radiant intensities were in reasonable agreement with experiments but deviated at late times.
Application of mode coupling method in modes purification of overmoded relativistic backward wave oscillators
Authors: Yuan Yuzhang , Zhang Jun , Zhong Huihuang , Zhang Dian
Published: March 2017

This paper applies mode coupling method to the design of modes purification device. With this method, the length of the phase adjustment waveguide can be computed precisely, which can increase the efficiency of design. With the new method, we design a purification device for an X-band overmoded relativistic backward wave oscillator and the output mixed modes of 66.6% TM01 and 33.4% TM02 are purified to be 99.47% TM01 mode and 0.53% TM02 mode, respectively. Since mode composition is hard to measure in experiments, analysis and discussion are made regarding the modes purifier, and moreover calculation formula of purification effect of other modes ratio after going through the mode purifier is derived, which can be used in evaluating and forecasting the effects of the mode purifier.
Research Update: Recent progress in the development of effective dielectrics for high-output triboelectric nanogenerator
Authors: Lee Jae Won , Ye Byeong Uk , Baik Jeong Min
Published: March 2017

A new energy generating device, triboelectric nanogenerator (TENG), was discovered in 2012 and thereafter, many applications such as portable power sources and self-powered, appropriate for portable electronic devices. So far, rapid development of device fabrication technologies and mechanical system designs significantly increased the instantaneous output power up to several tens of mW/cm2. This article provides a comprehensive review of effective dielectrics used so far in TENGs for further enhancement in output power, as well as the fundamental issues regarding the materials. Finally, we show some strategies for obtaining the properties that the materials should have as effective dielectrics.
Anomalous phase transition of Bi-doped Zn2GeO4 investigated by electrical conductivity and Raman spectroscopy under high pressure
Authors: Wu Lei , Dai LiDong , Li HePing , Hu Haiying , Zhuang YuKai , Liu KaiXiang
Published: March 2017

We present a pressure-induced amorphization for pure and 0.5 mol. % Bi3+-doped Zn2GeO4 samples, measured by high pressure Raman spectroscopy and high resolution transmission electron microscopy. Pressure-induced conductivity switching phenomena were discovered for both samples at around ∼7.01 GPa and ∼11.11 GPa, respectively, which closely correlated with the crystalline-to-amorphous transformation. The detailed conduction mechanism and the defect reaction process at high pressure indicate that the application of pressure could efficiently manipulate the microstructure and electrical performance of rare-earth doped polycrystalline materials, and therefore holds great promise for numerous applications in the future.
Current-driven skyrmion dynamics in disordered films
Authors: Kim Joo-Von , Yoo Myoung-Woo
Published: March 2017

A theoretical study of the current-driven dynamics of magnetic skyrmions in disordered perpendicularly magnetized ultrathin films is presented. The disorder is simulated as a granular structure, in which the local anisotropy varies randomly from grain to grain. The skyrmion velocity is computed for different disorder parameters and ensembles. Similar behavior is seen for spin-torques due to in-plane currents and the spin Hall effect, where a pinning regime can be identified at low currents with a transition towards the disorder-free case at higher currents, similar to domain wall motion in disordered films. Moreover, a current-dependent skyrmion Hall effect and fluctuations in the core radius are found, which result from the interaction with the pinning potential.
Records in fractal stochastic processes
Authors: Aliakbari A. , Manshour P. , Salehi M. J.
Published: March 2017

The record statistics in stationary and non-stationary fractal time series is studied extensively. By calculating various concepts in record dynamics, we find some interesting results. In stationary fractional Gaussian noises, we observe a universal behavior for the whole range of Hurst exponents. However, for non-stationary fractional Brownian motions, the record dynamics is crucially dependent on the memory, which plays the role of a non-stationarity index, here. Indeed, the deviation from the results of the stationary case increases by increasing the Hurst exponent in fractional Brownian motions. We demonstrate that the memory governs the dynamics of the records as long as it causes non-stationarity in fractal stochastic processes; otherwise, it has no impact on the record statistics.
High performance capacitors via aligned TiO2 nanowire array
Authors: Zhang Dou , Liu Weiwei , Tang Lin , Zhou Kechao , Luo Hang
Published: March 2017

Capacitors generally suffer from low energy density, which seriously limits their applications in energy storage devices. In this letter, TiO2 nanowire arrays were synthesized by a hydrothermal method and the morphologies were tuned by modulating the concentration of the Ti source. High energy density was realized after incorporating TiO2 nanowire arrays into a polyvinylidene fluoride matrix. The alignment of TiO2 nanowires with the direction of the applied electric field played an important role in achieving high breakdown strength and energy density, i.e., 380 kV/mm and 23.21 J/cm3, respectively. The findings provide a route to increase the energy density of polymer capacitors.
New resistances offer opportunity for effective management of the downy mildew (Hyaloperonospora parasitica) threat to canola
Authors: Mohammed A. E. , You M. P. , Barbetti M. J.
Published: March 2017

Downy mildew (Hyaloperonospora parasitica) is a problem for canola production worldwide, including in Australia where it has remained a persistent threat since 1998. Testing of 131 Brassicaceae varieties, including 109 Australian canola varieties (Brassica napus and B. juncea) and 22 diverse Brassicaceae (including B. napus, B. carinata, B. juncea, B. nigra, B. rapa, Crambe abyssinica and Raphanus sativus) highlighted excellent resistance to downy mildew. Using a mixture of 10 H. parasitica isolates, R. sativus Colonel and Boss showed highest resistance to H. parasitica, with per cent disease index (%DI) values of 3.7% and 10.2%, respectively. These were followed by (%DI values): B. carinata ATC 94011 (11.1%), B. napus CB™ Tanami (14.1%) and Komet-741 A (14.3%), B. juncea 397.23.2.3.3 (14.8%), B. napus ATR-Banjo (16.9%), Hyola 575 CL (16.9%), Komet-744 A (18.1%), Cresor-770 B (18.5%), Wamus (18.5%), Surpass 400 (19.2%), Hyola 432 (19.4%) and Hyola 76 (19.4%), and C. abyssinica (19.9%). These varieties were also considered highly resistant. Another five B. juncea genotypes and B. nigra P.23845 were considered highly resistant with %DI of 22.2%. Those considered resistant (but not highly resistant) included hybrid B. napus Hyola 444 TT, Hyola 500 RR, Hyola 504 RR, Pioneer 46Y78, Pioneer 45Y77 and Hyola 650 TT, and the non-hybrid variety ATR-Eyre, all with %DI values 23.1–28.2%. By contrast, B. napus Thunder TT, Hyola 450 TT and ATR-Grace were highly susceptible with %DI values of 90.3%, 88.2% and 81.7%, respectively. Cluster analysis revealed six distinct clusters (highly resistant, resistant, moderately resistant, moderately susceptible, susceptible, very susceptible) for the tested Brassicaceae genotypes that, on average, showed similar responses within each cluster against H. parasitica based on their %DI values. From 2000 onwards (with the exception of Surpass 400), 10 B. napus varieties and one B. juncea released were classified as highly resistant; however, there was no overall correlation between year of variety release and level of resistance expressed against H. parasitica. This is the first study to demonstrate the existence of very high levels of pathotype-independent resistance in Australian canola varieties to H. parasitica. The most resistant varieties identified can be used in canola breeding programs and also directly deployed into regions where downy mildew is prevalent, providing the canola industry with an immediate and effective option for management of this important disease.
Emissions of forest floor and mineral soil carbon, nitrogen and mercury pools and relationships with fire severity for the Pagami Creek Fire in the Boreal Forest of northern Minnesota
Authors: Kolka Randall K. , Sturtevant Brian R. , Miesel Jessica R. , Singh Aditya , Wolter Peter T. , Fraver Shawn , DeSutter Thomas M. , Townsend Phil A.
Published: March 2017

Forest fires cause large emissions of C (carbon), N (nitrogen) and Hg (mercury) to the atmosphere and thus have important implications for global warming (e.g. via CO2 and N2O emissions), anthropogenic fertilisation of natural ecosystems (e.g. via N deposition), and bioaccumulation of harmful metals in aquatic and terrestrial systems (e.g. via Hg deposition). Research indicates that fires are becoming more severe over much of North America, thus increasing element emissions during fire. However, there has been little research relating forest floor and mineral soil losses of C, N and Hg to on-the-ground indices of fire severity that enable scaling up those losses for larger-scale accounting of fire-level emissions. We investigated the relationships between forest floor and mineral soil elemental pools across a range of soil-level fire severities following the 2011 Pagami Creek wildfire in northern Minnesota, USA. We were able to statistically differentiate losses of forest floor C, N and Hg among a five-class soil-level fire severity classification system. Regression relationships using soil fire severity class were able to predict remaining forest floor C, N and Hg pools with 82–96% confidence. We correlated National Aeronautics and Space Administration Airborne Visible and Infrared Imaging Spectrometer-Classic imagery to ground-based plot-scale estimates of soil fire severity to upscale emissions of C, N and Hg to the fire level. We estimate that 468 000 Mg C, 11 000 Mg of N and over 122 g of Hg were emitted from the forest floor during the burning of the 28 310 ha upland area of the Pagami Creek fire.
Comparing nonpharmaceutical interventions for containing emerging epidemics
Authors: Peak Corey M. , Childs Lauren M. , Grad Yonatan H. , Buckee Caroline O.
Published: March 2017

Significance

Quarantine and symptom monitoring of contacts with suspected exposure to an infectious disease are key interventions for the control of emerging epidemics; however, there does not yet exist a quantitative framework for comparing the control performance of each intervention. Here, we use a mathematical model of seven case-study diseases to show how the choice of intervention is influenced by the natural history of the infectious disease, its inherent transmissibility, and the intervention feasibility in the particular healthcare setting. We use this information to identify the most important characteristics of the disease and setting that need to be considered for an emerging pathogen to make an informed decision between quarantine and symptom monitoring.
Mouse model of Epstein–Barr virus LMP1- and LMP2A-driven germinal center B-cell lymphoproliferative disease
Authors: Minamitani Takeharu , Ma Yijie , Zhou Hufeng , Kida Hiroshi , Tsai Chao-Yuan , Obana Masanori , Okuzaki Daisuke , Fujio Yasushi , Kumanogoh Atsushi , Zhao Bo , Kikutani Hitoshi , Kieff Elliott , Gewurz Benjamin E. , Yasui Teruhito
Published: March 2017

Significance

Epstein–Barr virus (EBV) is a major cause of B-cell lymphomas in immunocompromised hosts, where viral oncoproteins cause malignancy with loss of immunosurveillance. The EBV membrane oncoproteins latent membrane protein 1 (LMP1) and LMP2A are coexpressed in EBV-associated immunosuppressed host and Hodgkin lymphomas, where they activate key B-cell growth and survival pathways. We established a transgenic mouse model of LMP1/2A coexpression in germinal center (GC) B cells, the cell type from which most EBV-driven lymphomas arise. Our model highlighted synergistic LMP1/2A effects on this important B-cell population. Upon suppression of T and natural killer cells, LMP1/2A caused B-cell differentiation into rapidly growing plasmablasts that were not observed with LMP1 or LMP2A alone. Our model highlights synergistic LMP1/2A GC B-cell effects and recapitulates key aspects of EBV-driven lymphoproliferative disease.