bluuebunny/crossref_metadata_2025 huggingface dataset:
L’ADN mitochondrial, un potentiel codant mésestimé
Authors: Angers Annie , Ouimet Philip , Tsyvian-Dzyabko Assia , Nock Tanya , Breton Sophie
Published: January 2019

Du génome bactérien de l’endosymbionte d’origine les mitochondries animales n’ont retenu que 13 séquences codant des polypeptides essentiels à la production d’ATP. La découverte de petits peptides d’origine mitochondriale vient remettre en question cette interprétation du génome des mitochondries et suggère que leur potentiel codant reste sous-estimé. L’humanine, MOTS-c, les SHLP et Gau sont des peptides dérivés de l’ADN mitochondrial dont l’existence a été démontrée expérimentalement et qui jouent des rôles importants dans la régulation de l’apoptose et du métabolisme cellulaire. Chez certains bivalves à transmission doublement uniparentale des mitochondries, des gènes codant des peptides additionnels ont été découverts et pourraient être impliqués dans la détermination du sexe de ces animaux.
Système lymphatique et cerveau
Authors: Thomas Jean-Léon , Jacob Laurent , Boisserand Ligia
Published: January 2019

L’activité métabolique considérable du système nerveux central (SNC) requiert un système efficace de drainage et de détoxification tissulaire. Le SNC est pourtant dépourvu de vaisseaux lymphatiques qui assurent le drainage des fluides interstitiels et la surveillance immunitaire dans la plupart des tissus. Un système circulatoire original a été récemment découvert entre le liquide céphalo-rachidien (LCR), le parenchyme cérébral et les vaisseaux lymphatiques des méninges. Le système « glymphatique » implique les espaces périvasculaires et les astrocytes qui drainent les fluides interstitiels depuis et vers le LCR. Des vaisseaux lymphatiques méningés complètent le système glymphatique cérébral en assurant la clairance des macromolécules et des antigènes vers le réseau lymphatique périphérique. Le couple « glymphatique-lymphatiques méningés » constitue ainsi un ensemble de nouvelles cibles thérapeutiques pour améliorer le drainage cérébral et la surveillance immunitaire dans les maladies du SNC.
Numerical simulations of ICME–ICME interactions
Authors: Niembro Tatiana , Lara Alejandro , González Ricardo Francisco , Cantó Jorge
Published: January 2019

We present hydrodynamical simulations of the interaction of Coronal Mass Ejections (CME) in the Interplanetary Medium (IPM). In these events, two consecutive CMEs are launched from the Sun in similar directions within an interval of time of a few hours. In our numerical model, we assume that the ambient solar wind is characterized by its velocity and mass-loss rate. Then, the CMEs are generated when the flow velocity and mass-loss rate suddenly change, with respect to the ambient solar wind conditions during two intervals of time, which correspond to the duration of each CME. After their interaction, a merged region is formed and evolve as a single structure into the IPM. In this work, we are interested in the general morphology of this merged region, which depends on the initial parameters of the ambient solar wind and the CMEs involved. In order to understand this morphology, we have performed a parametric study in which we characterize the effects of the initial parameters variations on the density and velocity profiles at 1 AU, using as reference the well-documented event of July 25th, 2004. Based on this parametrization we were able to reproduce the main features of the observed profiles ensuring the travel time and the speed and density magnitudes. Then, we apply the parametrization results to the interaction events of May 23, 2010; August 1, 2010; and November 9, 2012. With this approach and varying the values of the input parameters within the CME observational errors, our simulated profiles reproduce the main features observed at 1 AU. Even though we do not take into account the magnetic field, our models give a physical insight into the propagation and interaction of ICMEs.
Differenzialdiagnose der Erythrozytose – Ursachen und klinische Bedeutung
Authors: Wille Kai , Sadjadian Parvis , Griesshammer Martin
Published: January 2019

Due to its rare incidence, erythrocytosis frequently represents a challenge for the treating doctors. The erythropoiesis (= production of erythrocytes) is located in the bone marrow, and the hormone erythropoietin (EPO) takes control in its regulation. Therefore, measurement of EPO in serum is one of the main diagnostic steps. In erythrocytosis, congenital causes have to be distinguished from acquired ones. Furthermore, there are primary and secondary forms. Congenital causes of erythrocytoses occur very infrequently, are mainly diagnosed in young age and should be treated in specialized centers. Polycythemia vera (PV), a clonal disorder and one of the main myeloproliferative neoplasms (beside essential thrombocythemia and primary myelofibrosis), represents the most frequent primary acquired cause of erythrocytosis. Clinically, increased thrombophilia and microvascular disturbance occur. The first-line treatment in patients with PV includes administration of aspirin and phlebotomies. Secondary acquired forms of erythrocytosis mainly occur due to hypoxia triggered by nicotine abuse or chronic heart and lung diseases. Regarding other differential diagnoses, a cancer-associated EPO production, kidney diseases or exogenous supply with EPO (= EPO doping) have to be considered.
Kommunikation zwischen Samuel Hahnemann und seinen Patienten
Authors: Dinges Martin , Holzapfel Klaus
Published: January 2019

Hahnemanns Kommunikation mit Patienten war von seinen Erwartungen an die Kooperations- und später zunehmend an die Folgebereitschaft der Patienten geprägt. So vermittelten die Praxisräumlichkeiten in Leipzig noch eher professionelle Sachlichkeit im Familienbetrieb, während sie in Paris die hervorgehobene Position des renommierten Behandlers in der Arzt-Patient-Beziehung unterstrichen. Die Kranken sollten genau über ihre Symptome, Vorbehandlung und die Nutzung von Hausmitteln berichten, auf die gleichzeitige Behandlung durch Dritte verzichten und die Vorschriften zur Medikamenteneinnahme und Diätetik genau beachten, ohne über die verschriebene Arznei informiert zu sein. Die Patienten erwarteten genaue Beachtung ihrer (schriftlichen) mitgeteilten Beschwerden, Deutung ihrer Symptome, eine gewisse Zuwendung, Linderung und ggf. Heilung. Zu den medizinischen Aspekten gehören Hahnemanns Anweisungen zur Diät und Lebensführung und sehr akribische Angaben zur Mitteleinnahme. Miasmatische Gesichtspunkte spielen ab ca. 1816 eine Rolle, sie werden zu anamnestischen Zwecken als Fragen an die Patienten formuliert. Diagnosen teilt Hahnemann nicht mit, allerdings betont er oft in suggestiver Weise die Dignität einer Erkrankung.
Inanspruchnahme einer Anschlussrehabilitation nach
orthopädischer Operation – Beeinflusst die Fallschwere das
Rehabilitationssetting (ambulant vs. stationär)?
Authors: Jankowiak Silke , Dannenmaier Julia , Ritter Sabrina , Kaluscha Rainer , Krischak Gert
Published: January 2019

Ziel Ziel der Untersuchung war es, Prädiktoren für
das Rehabilitationssetting (ambulant vs. stationär) nach
Akutaufenthalt zu bestimmen, um Hinweise auf die Bedeutung der Fallschwere
beim Zugang zu einer bestimmten Rehabilitationsform zu erhalten.

Methode Für die Auswertungen wurden Patienten2 ausgewählt, bei denen zwischen 2005
und 2010 eine Totalendoprothese (TEP) an Hüfte oder Kniegelenk
implantiert oder eine Bandscheibenoperation vorgenommen wurde. Anhand
anonymisierter Routinedaten der AOK Baden-Württemberg sowie der
Deutschen Rentenversicherungen Bund und Baden-Württemberg wurde
mittels logistischer Regression die Wahrscheinlichkeit modelliert, eine
stationäre Anschlussrehabilitation (AR) durchzuführen.

Ergebnisse Über alle 3 Operationsgruppen hinweg
führten Patienten, die unmittelbar nach dem Akutaufenthalt zur AR
kamen, eher eine stationäre Maßnahme durch, als Patienten,
die nach einer häuslichen Übergangszeit zur Rehabilitation
kamen. Mit zunehmendem Alter sowie bei Komorbiditäten wurde
häufiger eine stationäre AR in Anspruch genommen. Die
Wahrscheinlichkeit einer stationären Durchführung nahm im
Zeitraum zwischen 2005 und 2009 ab.

Schlussfolgerung Neben der Fallschwere scheinen Kontextfaktoren
für das Setting der AR eine Rolle zu spielen. Bei der
bedarfsorientierten Zugangssteuerung zu einer bestimmten Rehabilitationsform
sind individuelle Rahmenbedingungen, wie bspw. die Versorgung durch das
familiäre Umfeld bzw. die Erreichbarkeit therapeutischer,
pflegerischer und medizinischer Angebote, und medizinische Parameter,
d. h. die Erkrankungsschwere, gegeneinander abzuwägen.
Transition-Metal-Catalyzed Alkenyl sp2 C–H Activation: A Short Account
Authors: Maraswami Manikantha , Loh Teck-Peng
Published: January 2019

Alkenes are ubiquitous in Nature and their functionalization continues to attract attention from the scientific community. On the other hand, activation of alkenyl sp2 C–H bonds is challenging due to their chemical properties. In this short account, we elucidate, discuss and describe the utilization of transition-metal catalysts in alkene activation and provide useful strategies to synthesize organic building blocks in an efficient and sustainable manner.

1 Introduction

2 Breakthrough

3 Controlling E/Z, Z/E Selectivity

3.1 Esters and Amides as Directing Groups

3.2 The Chelation versus Non-Chelation Concept

4 Other Alkene Derivatives

5 Intramolecular C–H Activation

6 Conclusion and Future Projects
A Scalable, One-Pot Synthesis of 1,2,3,4,5-Pentacarbomethoxycyclopentadiene
Authors: Radtke M. , Dudley Caroline , O’Leary Jacob , Lambert Tristan
Published: January 2019

1,2,3,4,5-Pentacarbomethoxycyclopentadiene (PCCP) is a strong organic acid and a precursor to useful organocatalysts, including chiral Brønsted acids and silicon-based Lewis acids. The synthetic route to PCCP, first reported in 1942, is inconvenient for a number of reasons. The two-step synthesis requires the purification of intermediates from intractable side-products, high reaction temperatures, and extensive labor (3 days). We have developed an improved procedure that delivers PCCP efficiently in 24 hours in one pot at ambient temperature and without isolation.
General Synthetic Approach to Rotenoids via Stereospecific, Group-Selective 1,2-Rearrangement and Dual SNAr Cyclizations of Aryl Fluorides
Authors: Matsuoka Seiya , Nakamura Kayo , Ohmori Ken , Suzuki Keisuke
Published: January 2019

A general synthetic approach to rotenoids is described, featuring 1) stereospecific, group-selective 1,2-rearrangements of epoxy alcohols, and 2) SNAr oxy-cyclizations of aryl fluorides. The common intermediate epoxyketone, en route to (–)-rotenone and (–)-deguelin, was prepared from d-araboascorbic acid in five steps. Also described is the conversion of (–)-deguelin into oxidized congeners, (–)-tephrosin and (+)-12a-epi-tephrosin.
One-Pot Sequential Multistep Transformation of α,β-Unsaturated Trifluoromethyl Ketones: Facile Synthesis of Trifluoromethylated 2-Pyridones
Authors: Zhang Fa-Guang , Ma Jun-An , Lv Ning , Tian Yi-Qiang
Published: January 2019

A one-pot transformation of α,β-unsaturated trifluoromethyl ketones with 2-(phenylsulfinyl)acetamide to give trifluoromethylated 2-pyridones is realized. The reaction proceeds under mild conditions and involves multiple steps in an expeditious and controlled sequence to provide efficient access to a broad range of trifluoromethylated 2-pyridones in moderate to high yields. Moreover, further synthetic manipulations permit the routine synthesis of a diverse array of trifluoromethylated pyridines with good efficiency.
Influence of Offset on Hemodynamics of Intra-atrial Conduit Fontan's Procedure and Its Clinical Implications
Authors: Hu Jie , Wang Qian , Tong Zhirong , Shen Juanya , Liu Jinlong , Sun Yanjun , Zhang Haibo
Published: January 2019

Background The desirable distance, defined as offset, between the central line of the superior vena cava (SVC) and the intra-atrial conduit after an intra-atrial conduit (IAC) Fontan's procedure remained unclear. We compared the hemodynamic features using virtual surgery with different offset designs in our study.

Methods Three-dimensional models of IAC Fontan's procedure were reconstructed according to the magnetic resonance imagings (MRIs) of three patients, then four models for each patient with different offsets equaling 100, 67, 33, and 0% of the diameter of the IVC were reconstructed. Computational fluid dynamics (CFD) were performed in each model to predict the best hemodynamic features, including streamlines of blood flow, wall shear stress (WSS), energy loss (EL), and the hepatic flow distribution (HFD) ratio.

Results Comprehensive evaluation of WSS, EL, and HFD revealed than an offset of 33% presents the best hemodynamic performance among the three patients modeled. In patient A, an offset of 33% resulted in the best HFD (left pulmonary artery/right pulmonary artery [LPA/RPA] = 35/65%). In patient B, the best trade-off between HFD (35/65%), and WSS was achieved with an offset of 33%. In patient C, EL peaked at an offset of 0% and significantly dropped at an offset of 33% with a desirable HFD (60/40%).

Conclusions We verified that the offset distance influences hemodynamic performance in IAC Fontan's procedure. Considering several hemodynamic parameters, the best trade-offs between hemorheology, pulmonary perfusion, and energy efficiency were achieved at an offset of 33%. This distance should be taken into consideration and optimized during the surgical planning for the IAC Fontan's procedure.
Infektiöse Endokarditis
Authors: Knebel Fabian , Frumkin David , Flachskampf Frank
Published: January 2019

Infective endocarditis is a severe, mostly bacterial disease characterized by high mortality and morbidity. Both diagnosis and therapy are difficult, and mortality rates have not improved over decades. We review diagnostic and management problems, the disease's modern face in the era of widespread cardiac implants and valve interventions, and current diagnostic and therapeutic recommendations.
Assessing the economic viability of energy storage systems in the Chilean electricity system: An empirical analysis from arbitrage revenue perspectives
Authors: Osorio Héctor , Nasirov Shahriyar , Agostini Claudio A. , Silva Carlos
Published: January 2019

The emergence of high penetration rates of renewable energies in power systems presents a serious challenge in energy generation and load balance maintenance to ensure power network stability and reliability. Energy Storage Systems (ESSs) could play a relevant role in facing these challenges, as the technologies have passed the demo and prototype phases to a wide market implementation phase. The only remaining barrier for their implementation is their cost, but even this barrier is quickly disappearing. In this paper, we address the financial feasibility of storage technologies in electricity systems. In particular, we evaluate whether such technologies are economically sustainable and how far they are from becoming viable. For this purpose, we consider the Chilean electricity system and evaluate the maximum possible arbitrage revenues that could be achieved under ESS through benefiting from energy time shift, diminishing of transmission losses, and transmission upgrade deferral. The results show that the arbitrage revenues are still below the cost of storage systems. Further improvement in storage efficiency or a decrease in the cost of storage systems is still needed to make this type of investment financially viable in the near future.
Characteristic study of a transient spark driven by a nanosecond pulse power in atmospheric nitrogen using a water cathode
Authors: Wang Sen , Liu Feng , Yang De-zheng , Wang Wenchun , Fang Zhi
Published: January 2019

In this paper, a transient spark discharge is presented driven by a nanosecond pulse power with a needle-water electrode configuration in atmospheric nitrogen. The transient spark discharge concludes three phases, described as the streamer phase, the streamer-to-spark transition phase, and the spark phase. The amplitude of pulse voltage has a significant influence on the characteristics of the transient spark discharge. The streamer-to-spark transition time shortens with the increase of pulse voltage, and the spark current value increases with the increase of pulse voltage. Though the streamer-to-spark transition is not completely prevented, the gas temperature is still in a lower value (∼400 K), due to the short duration of spark current (200–400 ns). The electron density in the transient spark, calculated by the Stark broadening of the Hα line at 656 nm, is about 1.3 × 1017 cm−3, which is 2–3 orders of magnitude higher than that in other forms of gas-liquid discharge. The results indicate that the transient spark discharge plasma is in a highly non-equilibrium state and the results also present its other unique features of high electron density and abundant excited species.
An improved decomposition based multi-objective evolutionary algorithm for the operation management of a renewable micro-grid
Authors: Jin Shaozhen , Mao Zhizhong , Li Hongru , Qi Wenhai
Published: January 2019

This study presents a multiobjective energy management to optimize the renewable microgrid operation while satisfying a demand response and various operation constraints. With regard to energy cost minimization, pollutant emission reduction for better utilization of the renewable energy resources, such as wind and solar, as a competitive objective is proposed. Moreover, for maximizing the renewable microgrid operators, demand response benefits satisfying the load demand constraints amongst other operation constraints are incorporated into the operations of the renewable microgrid. The overall problem is formulated as a mixed-integer nonlinear constraint multiobjective optimization problem with different equality and inequality constraints. In this paper, an improved decomposition based multiobjective evolutionary algorithm is presented for optimal operation of the renewable microgrid with renewable energy sources and various devices such as diesel generators, micro-turbines, fuel cells, and battery energy storage. To improve the optimization process, differential evolution (DE) and the niche guided mating selection strategy are incorporated. Meanwhile, decomposition-based multiobjective evolutionary algorithm-DE is extended to tackle the constrained optimization problem. Finally, the proposed algorithm is applied in a renewable microgrid, and its superior performance is compared with the conventional evolutionary algorithms such as the multiobjective genetic algorithm and the original decomposition based multiobjective evolutionary algorithm.
Controlling the harmonic conversion efficiency in semiconductor superlattices by interface roughness design
Authors: Apostolakis A. , Pereira Mauro F.
Published: January 2019

In semiconductor superlattices, when Bragg oscillating electrons interact with an input electromagnetic field, frequency multiplication is possible. An ideal superlattice has a purely antisymmetric voltage current response and can thus produce only odd harmonics. However, real world superlattices can also have even harmonic response and that increases the range of possible output frequencies. These effects have been recently explained with a predictive model that combines an Ansatz solution for the Boltzmann Equation with a Nonequilibrium Green’s Functions approach. This predictive tool, coupled with recent progress on GHz input sources, support the growing interest in developing compact room temperature devices that can operate from the GHz to the THz range. The natural question to ask is what efficiencies can be expected. This paper addresses this issue by investigating power-conversion efficiency in irradiated semiconductor superlattices. Interface imperfections are consistently included in the theory and they strongly influence the power output of both odd and even harmonics. Good agreement is obtained for predicted odd harmonic outputs with experimental data for a wide frequency range. The intrinsic conversion efficiency used is based on the estimated amplitude of the input field inside the sample and thus independent of geometrical factors that characterize different setups. The method opens the possibility of designing even harmonic output power by controlling the interface quality.
Single-crystal-Ga2O3/polycrystalline-SiC bonded substrate with low thermal and electrical resistances at the heterointerface
Authors: Lin Chia-Hung , Hatta Naoki , Konishi Keita , Watanabe Shinya , Kuramata Akito , Yagi Kuniaki , Higashiwaki Masataka
Published: January 2019

A single-crystal β-Ga2O3 substrate was directly attached to a polycrystalline SiC (poly-SiC) substrate using a surface-activated-bonding method to enhance heat extraction from β-Ga2O3 devices. The effective thermal conductivity of the n+-Ga2O3/n+-poly-SiC bonded substrate and the electrical resistance at the heterointerface were characterized by using periodic heating radiation thermometry and analyzing vertical current–voltage characteristics, respectively. Small thermal and electrical resistances at the bonded interface demonstrated the strong prospects of the bonded substrates for applications to high-power vertical Ga2O3 devices.
Modifier clustering and avoidance principle in borosilicate glasses: A molecular dynamics study
Authors: Wang Mengyi , Smedskjaer Morten M. , Mauro John C. , Bauchy Mathieu
Published: January 2019

Oxide glasses are typically described as having a random, disordered skeleton of network-forming polyhedra that are depolymerized by network-modifying cations. However, the existence of local heterogeneity or clustering within the network-forming and network-modifying species remains unclear. Here, based on molecular dynamics simulations, we investigate the atomic structure of a series of borosilicate glasses. We show that the network-modifying cations exhibit some level of clustering that depends on composition—in agreement with Greaves’ modified random network model. In addition, we demonstrate the existence of some mutual avoidance among network-forming atoms, which echoes the Loewenstein avoidance principle typically observed in aluminosilicate phases. Importantly, we demonstrate that the degree of heterogeneity in the spatial distribution of the network modifiers is controlled by the level of ordering in the interconnectivity of the network formers. Specifically, the mutual avoidance of network formers is found to decrease the propensity for modifier clustering.
Ignition of discharges in macroscopic isolated voids and first electron availability
Authors: Villa Andrea , Barbieri Luca , Malgesini Roberto , Leon-Garzon Andres R.
Published: January 2019

Internal partial discharges and electrical treeing are some of the main aging mechanisms of all the polymeric insulating materials present in the power net. A better understanding of this process calls for the development of more sophisticated simulation tools, based on the numerical solution of first principles equations, i.e., a set of partial differential equations. The accuracy of the predictions of these models heavily relies on the quality of the set of physical parameters used as, for example, the swarm parameters. A key aspect is the correct representation of the first electron availability which triggers the discharge. These electrons are mainly injected into the gas from the interface between the gas itself and the solid polymeric matrix by means of the Schottky effect. The work function is a very relevant parameter in defining this effect, and so the entire quality of the simulation process depends on it. In this work, we estimate the value of the work function, using electronic structure calculations, and we perform some parametric analyses to show how the discharge simulations are affected by the variation of this quantity. In particular, we assume that the polymeric material is polyethylene, which is used extensively in the electric power transmission industry. The discharge simulations produce some relevant data that can be compared against experimental data for validation purposes.
Ultrathin oxide layers for nanoscale integration of molecular light
absorbers, catalysts, and complete artificial photosystems
Authors: Katsoukis Georgios , Frei Heinz
Published: January 2019

Artificial photosynthesis is an attractive approach for the generation of renewable fuels because such systems will be suitable for deployment on highly abundant, non-arable land. Recently emerged methods of nanoscience to create conformal, ultrathin oxide layers enable the hierarchical integration of light absorbers, catalysts, and membranes into systems with far simpler synthetic approaches than available till now. This holds in particular for the coupling of molecular light absorbers and catalysts for sunlight to fuel conversion, providing photoelectrodes with greatly improved stability. Moreover, the use of ultrathin inert oxides as proton conducting, molecule impermeable membranes has opened up the integration of reduction and oxidation half reactions into complete photosynthetic systems on the shortest possible length scale—the nanometer scale. This capability affords minimization of energy-degrading resistance losses caused by ion transport over macroscale distances while separating the incompatible water oxidation and carbon dioxide reduction catalysis environments on the nanoscale. Understanding of charge transport between molecular components embedded in the oxide layers is critical for guiding synthetic design improvements of the light absorber-catalyst units to optimize performance and integrate them into complete artificial photosystems. Recent results and insights from transient optical, vibrational, and photoelectrochemical studies are presented, and future challenges and opportunities for engaging dynamic spectroscopies to accelerate the development of nanoscale integrated artificial photosystems are discussed.
Analysis of grid connected hybrid renewable energy system
Authors: Belfedhal Seifeddine Abdelkader , Berkouk EL Madjid , Messlem Youcef
Published: January 2019

This paper proposes a DC-linked hybrid renewable energy system (HRES) connected to the grid through a three level neutral point clamped converter. The proposed structure consists of a wind generator (with Maximum Power Point Tracking (MPPT)), power limitation, and pitch control modes) with a flywheel energy storage system, a photovoltaic generator (MPPT and power limitation modes) with a battery, and a super-capacitor connected to each capacitor of the DC link of the three level converter. With the aim of managing the power flow between the HRES, the grid, and the variable load demand, we designed a power management strategy according to the global state of charge of the storage system, the weather conditions, and the load demand. In order to show the efficiency of the proposed structure and management algorithm, numerical simulation was performed using MATLAB/Simulink.
Insight of the thermal conductivity of ϵ-iron at Earth’s core conditions from the newly developed direct ab initio methodology
Authors: Yue Sheng-Ying , Hu Ming
Published: January 2019

The electronic thermal conductivity of iron at the Earth’s core conditions is an extremely important physical property in the geophysics field. However, the exact value of electronic thermal conductivity of iron under extreme pressure and temperature still remains poorly known both experimentally and theoretically. A few recent experimental studies measured the value of the electronic thermal conductivity directly and some theoretical works have predicted the electronic thermal conductivity of iron at the Earth’s core conditions based on the Kubo-Greenwood method. However, these results differ largely with each other. A very recent research has confirmed that for iron at the Earth’s core conditions, the strength of electron-electron scattering could be comparable to that for electron-phonon scattering, meaning that the electron-electron scattering should also be considered when evaluating the electronic thermal conductivity in the Earth’s core situations. Here, by utilizing a newly developed methodology based on direct non-equilibrium ab initio molecular dynamics simulation coupled with the concept of electrostatic potential oscillation, we predict the electronic thermal conductivity of iron in h.c.p. phase. Our methodology inherently includes the electron-phonon and electron-electron interactions under extreme conditions. Our results are comparable to the previous theoretical and experimental studies. More importantly, our methodology provides a new physical picture to describe the heat transfer process in ϵ-iron at the Earth’s core conditions from the electrostatic potential oscillation point of view and offers a new approach to study the thermal transport property of pure metals in the planet’s cores with different temperature and pressure.
Pinning and depinning: From periodic to chaotic and random media
Authors: Ankney N. , Avery M. , Khain T. , Scheel A.
Published: January 2019

We study the propagation of dissipative structures in inhomogeneous media with a focus on pinning and depinning transitions. We model spatial complexity in the medium as generated by dynamical systems. We are thus able to capture transitions from periodic to quasiperiodic, to homoclinic and heteroclinic, and to chaotic media. Depinning bifurcations exhibit universal laws depending on extreme value statistics that are encoded in the dimension of ergodic measures, only. A key condition limiting this approach bounds spatial Lyapunov exponents in terms of interface localization, and we explore the breakdown of smoothness and universality when this condition is violated and fluctuations in the medium occur on length scales shorter than a typical interface width.
Wideband and low-profile transmitarray antenna using transmissive metasurface
Authors: Liu Yajun , Zhang Anxue , Xu Zhuo , Xia Song , Shi Hongyu
Published: January 2019

Based on the Pancharatnam-Berry phase principle, a wideband low-profile transmissive metasurface was designed and applied to a transmitarray antenna (TA). While a full transmission phase range of 360° was achieved by rotating the proposed unit cell, the transmission coefficient was always close to 1 in the frequency range of 10.4–11.6 GHz. Hence, a TA comprised of 20 × 20 unit cells of size 180 mm × 180 mm was designed and fabricated. The simulated results agreed well with the experimental data, validating the excellent performance of the proposed metasurface structure. The measured peak gain of the TA was 21.64 dB at 11 GHz, resulting in an aperture efficiency of 34%. In addition, we attained a 12% 1-dB gain bandwidth (10.2–11.5 GHz) and an 18% 3-dB axial ratio bandwidth (10–12 GHz) for the TA. The proposed metasurface exhibits distinct performance benefits in terms of having wide bandwidth, low-profile, and high-efficiency, as well as represents a promising design option for a high-performance TA.
The effect of scattered neutrons on the ion temperature measurement with different line-of-sight on the SGIII laser facility
Authors: Chen Zhongjing , Zheng Jianhua , Yan Ji , Zhang Xing , Pu Yudong , Dong Yunsong , Huang Tianxuan , Jiang Wei , Yu Bo , Chen Bolun , Tang Qi , Song Zifeng , Xie Xufei , Wang Feng , Yang Jiamin
Published: January 2019

Two neutron time-of-flight (nToF) detectors have been employed to measure the neutron time-of-flight spectrum in different lines-of-sight, i.e., at the equator plane and the south pole, on Shenguang-III (SG-III) laser facility. The contribution of scattered neutrons has been calculated with the Monte Carlo code JMCT for each nToF detector. The results show that the scattered neutron spectrum is dominated by neutrons scattered on materials in the experiment hall, including the vacuum chamber. The shape of the scattered neutron spectrum depends on the view line, which has been observed with nToF detectors located in the experiment hall of the SG-III laser facility. A method based on the convolution of the calculated neutron time-of-flight spectrum and the instrument response function has been developed for the ion temperature determination. The calculated neutron spectra with the contribution of scattered neutrons can fit the measured results. No obvious ion temperature anisotropy has been observed on the SG-III laser facility at present.
Generalized single-parameter aging tests and their application to glycerol
Authors: Roed Lisa Anita , Hecksher Tina , Dyre Jeppe C. , Niss Kristine
Published: January 2019

Physical aging of glycerol following temperature jumps is studied by dielectric spectroscopy at temperatures just below the glass transition temperature. The data are analyzed using two single-parameter aging tests developed by Hecksher et al. [J. Chem. Phys. 142, 241103 (2015)]. We generalize these tests to include jumps ending at different temperatures. Moreover, four times larger jumps than previously are studied. The single-parameter aging tests are here for the first time applied to a hydrogen-bonded liquid. We conclude that glycerol obeys single-parameter aging to a good approximation.
Influence of a target on the electric field profile in a kHz atmospheric pressure plasma jet with the full calculation of the Stark shifts
Authors: Hofmans Marlous , Sobota Ana
Published: January 2019

The electric field in the head of the plasma bullet (ionization wave) in a cold atmospheric pressure plasma jet is measured using the Stark polarization spectroscopy technique, a noninvasive method. The jet is driven by 1μs long voltage pulses at 6 kV amplitude and 5 kHz frequency, and a helium gas flow of 1.5 slm. Two helium lines (447.1 nm and 492.2 nm) are studied, from which the peak-to-peak wavelength difference between the allowed and forbidden band of the spectral lines is determined. The full derivation to obtain the electric field from this peak-to-peak difference is included in this paper. The electric field is determined both inside and outside the capillary of the jet, up to about 2 cm in the effluent of the jet. Measurements are performed on the freely expanding jet, but especially the influence is studied when a target is placed in front of the plasma jet. Targets with different properties are used: insulating (polyvinyl chloride, PVC), conducting (copper), liquid (distilled water and saline), and organic (chicken breast). It is found that a target changes the electric field of the plasma jet and thus changes the plasma itself. This change depends on the dielectric constant or conductivity of the target: a higher dielectric constant or higher conductivity yields a higher electric field. For a low dielectric constant (ϵr≈3), the change in the electric field is negligible. Decreasing the distance between the target and the capillary to below 2 cm yields an increase in the electric field.
A microscopic approach to heating rate of ferrofluid droplets by a magnetic field
Authors: Siqueira E. C. , Junior L. R. N. , Jurelo A. R. , Monteiro J. F. H. L. , Orellana P. A. , Cabrera G. G. , Fachini F. F.
Published: January 2019

In this work, we study the heating process of colloidal ferrofluids by a magnetic field. The heating of the fluid occurs by the magnetic relaxation of the nanoparticles which provide thermal energy for the host liquid. In the limit of small volumes, the relaxation process occurs through the Néel mechanism since the magnetic nanoparticles present superparamagnetic behavior. Within this limit, we have used a microscopic model for the coupling to phonons and external magnetic field in order to model the relaxation mechanism and to obtain an expression for the heating rate of the fluid as a function of microscopic parameters. The analysis allows determining appropriate conditions for an optimal heating rate for ferrofluids based on superparamagnetic nanoparticles.
Wave spectra of square-lattice domains in a quasi-two-dimensional binary complex plasma
Authors: Huang H. , Ivlev A. V. , Nosenko V. , Lin Y.-F. , Du C.-R.
Published: January 2019

Domains of the square lattice have been observed in a quasi-two-dimensional binary complex plasma. The longitudinal and transverse modes of the wave spectra were measured. To compare with the experiment, Langevin dynamics simulations of a binary mixture were carried out, where the non-reciprocal interactions between different species were modeled with a point-wake Yukawa potential. A strong dependence of the wave spectra on the relative magnitude of the point-wake charge is revealed.
Existence theory and numerical solutions to smoking model under Caputo-Fabrizio fractional derivative
Authors: Khan Sajjad Ali , Shah Kamal , Zaman Gul , Jarad Fahd
Published: January 2019

In this paper, taking fractional derivative due to Caputo and Fabrizo, we have investigated a biological model of smoking type. By using Sumudu transform and Picard successive iterative technique, we develop the iterative solutions for the considered model. Furthermore, some results related to uniqueness of the equilibrium solution and its stability are discussed utilizing the techniques of nonlinear functional analysis. The dynamics of iterative solutions for various compartments of the model are plotted with the help of Matlab.
Experimental investigation on the interaction process between coal particles and foam
Authors: Han Fangwei , Zhang Jinyi , Zhao Yue , Han Jihui
Published: January 2019

The utilization of foam for coal dust control has been proven to be an efficient clean technology. To investigate the interaction between coal particles and foam, the process that coal particles settling onto foam was captured via a high-speed camera in this research. The changes of the foam film and the dispersion of coal particles in the foam system during the interaction process were observed. The results revealed that the deformation and rupture of the foam film are the main modes that alleviating the impact of the coal particles. When a coal particle adhered to the foam film, it would slide on the foam film along the following path in order: from the film, to the Plateau borders, finally arrived at the vertices. Two distinct stages of coal dust removal using foam were identified. The forces acting on a coal particle during the two stages were modelled mathematically. The results are meaningful for a profound understanding of the coal dust capture process using foam.
Electrical contact uniformity and surface oxidation of ternary chalcogenide alloys
Authors: Sharma P. A. , Brumbach M. , Adams D. P. , Ihlefeld J. F. , Lima-Sharma A. L. , Chou S. , Sugar J. D. , Lu P. , Michael J. R. , Ingersoll D.
Published: January 2019

Uniform metal contacts are critical for advanced thermoelectric devices. The uniformity of the contact resistance for gold, tungsten, and SrRuO3 electrodes on polycrystalline ternary Bi2Te3-based alloys for different types of surface cleaning procedures was characterized. The presence of a nanometer-thick native oxide layer on the Bi2Te3 surface leads to large and non-uniform contact resistance. Surface treatments included solvent cleans and chemical and dry etching prior to metallization of the Bi2Te3. Only etching the surface led to a significant improvement in contact resistance uniformity. None of the tested contacts reacted with the underlying Bi2Te3 substrate. Etching resulted in the removal of the native oxide on the Bi2Te3 surface, which was characterized using X-ray photoelectron spectroscopy (XPS). The average thickness, chemistry, and dry etch rate of the native oxide was further characterized using XPS. The non-uniformity in contact resistance suggests that the native oxide grows non-uniformly on polycrystalline bismuth telluride surfaces.
Perspective: How can ultrafast laser spectroscopy inform the design of new organic photoredox catalysts for chemical and materials synthesis?
Authors: Orr-Ewing Andrew J.
Published: January 2019

Photoredox catalysis of chemical reactions, using light-activated molecules which serve as electron donors or acceptors to initiate chemical transformations under mild conditions, is finding widespread use in the synthesis of organic compounds and materials. The transition-metal-centred complexes first developed for these photoredox-catalysed applications are steadily being superseded by more sustainable and lower toxicity organic photocatalysts. While the diversity of possible structures for photoredox-active organic molecules brings benefits of design flexibility, it also presents considerable challenges for optimization of the photocatalyst molecular architecture. Transient absorption spectroscopy over timescales from the femtosecond to microsecond domains can explore the detailed mechanisms of activation and reaction of these organic photocatalysts in solution and, by linking their dynamical properties to their structures, has the potential to establish reliable design principles for future development of improved photocatalysts.
Quantum-state-resolved studies of aqueous evaporation dynamics: NO ejection from a liquid water microjet
Authors: Ryazanov Mikhail , Nesbitt David J.
Published: January 2019

This work presents the first fully quantum-state-resolved measurements of a solute molecule evaporating from the gas–liquid interface in vacuum. Specifically, laser-induced fluorescence detection of NO(2Π1/2, 3/2, v = 0, J) evaporating from an ∼5 mM NO–water solution provides a detailed characterization of the rotational and spin–orbit distributions emerging from a ⌀4–5 μm liquid microjet into vacuum. The internal-quantum-state populations are found to be well described by Boltzmann distributions, but corresponding to temperatures substantially colder (up to 50 K for rotational and 30 K for spin–orbit) than the water surface. The results therefore raise the intriguing possibility of non-equilibrium dynamics in the evaporation of dissolved gases at the vacuum–liquid-water interface. In order to best interpret these data, we use a model for evaporative cooling of the liquid microjet and develop a model for collisional cooling of the nascent NO evaporant in the expanding water vapor. In particular, the collisional-cooling model illustrates that, despite the 1/r drop-off in density near the microjet greatly reducing the probability of collisions in the expanding water vapor, even small inelastic cross sections (≲ 20 Å2) could account for the experimentally observed temperature differences. The current results do not rule out the possibility of non-equilibrium evaporation dynamics, but certainly suggest that correct interpretation of liquid-microjet studies, even under conditions previously considered as “collision-free,” may require more careful consideration of residual collisional dynamics.
Influence of magnetic field taper on second harmonic 394GHz gyrotron oscillator
Authors: Wang Xuewei , Xue Qianzhong , Zhang Shan , Zhao Guohui , Liu Gaofeng , Zhao Ding
Published: January 2019

Medium-power gyrotron operating in high frequency usually operates in harmonics to reduce the required guiding magnetic field strength. Low guiding magnetic field is in favor of compact gyrotron, which makes it easier to apply the gyrotron to large scale devices and to extend the applications of gyrotron to wider fields. However, high harmonic modes suffer from low intensity of cyclotron radiation and additional competition with neighboring fundamental modes. As we all know, single mode operation can be realized by using a special startup scenario and a positive magnetic field taper can increase output efficiency. The influence of magnetic field taper on gyrotron operation is studied by generalizing the well-known η⊥μ,F plot, which just discussed the transverse efficiency using Gaussian field profile and not took the self-consistent non-stationary codes or ohmic dissipation into consideration. In this paper, linear and self-consistent nonlinear codes are used to investigate influences of magnetic field taper on start current and output parameters of a 394 GHz gyrotron, which is designed for enhancement of Nuclear Magnetic Resonance spectroscopy through Dynamic Nuclear Polarization. Simulation results show that when the magnetic field taper is +0.04 T the maximum output power is obtained and the maximum value is 3% larger than that corresponding to uniform magnetic field. Appropriate startup scenario is designed for single mode operation and multimode simulation is carried out to demonstrate that mode TE261+ dose dominate in mode competition in the designed startup path.
Simulation analysis of production decision optimization of supply chain system based on nonlinear system and fractional differential operator
Authors: Jin Maozhu , Song Lijun , Wang Hua , Zhang Qian
Published: January 2019

In order to study the effects of two strategies of the non-linear supply chain with and without shortage on the dynamic behavior of remanufacturing supply chain system, a non-linear system model with non-return supply constrained by the current level of supply service and recovery capacity constrained by the maximum recovery capacity is established, which is more in line with the actual situation. In order to accurately analyze the dynamic performance of the system so as to effectively suppress the impact of uncertainty and ultimately achieve the stable operation of the system, the research on the operation process of the nonlinear supply chain system is deepened and the fuzzy robust control method is deeply studied. The mitigation of the lead time, the uncertain parameters inside the system, and the external customer demand cause large fluctuations in the system operation process. It is of great practical significance to improve the efficiency of the supply chain, enhance the competitiveness of enterprises, and achieve healthy and stable economic development.
Research on dynamic nonlinear input prediction of fault diagnosis based on fractional differential operator equation in high-speed train control system
Authors: Cao Yuan , Zhang Yuzhuo , Wen Tao , Li Peng
Published: January 2019

In order to control the nonlinear high-speed train with high robustness, the fractional order control of nonlinear switching systems is studied. The fractional order controller is designed for a class of nonlinear switching systems by the fractional order backstepping method. In this paper, a simple and effective online updating scheme of model coefficients is proposed by using the flexibility of the model predictive control algorithm and its wide range of model accommodation. A stochastic discrete nonlinear state space model describing the mechanical behavior of a single particle in a high-speed train is constructed, and the maximum likelihood estimation of the parameters of a high-speed train is transformed into an optimization problem with great expectations. Finally, numerical comparison experiments of motion characters of two high-speed trains are given. The results show the effectiveness of the proposed identification method.
Microbe-focused glycan array screening platform
Authors: Geissner Andreas , Reinhardt Anika , Rademacher Christoph , Johannssen Timo , Monteiro João , Lepenies Bernd , Thépaut Michel , Fieschi Franck , Mrázková Jana , Wimmerova Michaela , Schuhmacher Frank , Götze Sebastian , Grünstein Dan , Guo Xiaoqiang , Hahm Heung Sik , Kandasamy Jeyakumar , Leonori Daniele , Martin Christopher E. , Parameswarappa Sharavathi G. , Pasari Sandip , Schlegel Mark K. , Tanaka Hidenori , Xiao Guozhi , Yang You , Pereira Claney L. , Anish Chakkumkal , Seeberger Peter H.
Published: January 2019

Significance

The interplay between glycan binding proteins and their carbohydrate ligands is fundamental to all aspects of life. Printed glycan arrays have helped to elucidate the role of glycans in many biological processes with monosaccharide resolution, particularly those of mammalian origin, over the past 15 y. Current microbial glycan arrays contain specialized small synthetic collections or isolated carbohydrates but better coverage is needed as microbes are enveloped in complex layers of carbohydrates. The chemically diverse microbial glycans play crucial roles in immunity and infectious diseases. We present an extensive synthetic glycan collection focused on microbial glycans as a tool to investigate microbial glycobiology.