bluuebunny/crossref_metadata_2025 huggingface dataset:
New Fission Product Yield Measurements at Oregon State University
Authors: Tamashiro Aaron , Burke Jason , Padgett Stephen , Burcher Sean , Palmer Todd , Palmer Camille
Published: September 2020

Cumulative fast fission product yields for 235 U and 238 U were measured at Godiva-IV in burst mode. Data was collected starting 45 minutes after the prompt irradiation. Data analysis codes were developed to analyze gammarays and calculate fission product yields with their respective uncertainties. Due to uncertainties in the branching ratios, different γ-rays from the same isotope led to different fission yield. This led to an effort at Oregon State University (OSU) to utilize the Rabbit facility at their 1 MegaWatt Training, Research, Isotopes, General Atomics (TRIGA) nuclear research reactor. The new experimental setup will allow us to measure branching ratio data and short-lived fission product yields starting seconds after a prompt irradiation.
Toward next JENDL Fission Yield Data and Decay Data
Authors: Minato Futoshi
Published: September 2020

JENDL group has developed evaluated fission yield and decay data. They are now planned to be upgraded in order to embody new experimental data and theoretical developments obtained after the last release. In this paper, we briefly describe a plan and present activity toward next JENDL fission yield and decay data.
Coconut milk gavage enhanced fecal bile excretion by modulating hepatic Fxr expression but failed to improve fasting serum cholesterol profile in C57BL/6 mice
Authors: Wong Hong Kin , Choo Quok Cheong , Chew Choy Hoong
Published: September 2020

The consumption of coconut milk has long been regarded as detrimental to cardiovascular health due to its high saturated fatty acid content. Contradictorily, emerging evidences have highlighted that the fatty acids in coconut lipids, which comprise mostly of medium-chain fatty acids (MCFA), may be beneficial to the regulation of serum cholesterol. To identify the potential health effect of coconut milk on lipid metabolism, this current study employed an intragastric gavage method on C57BL/6 mice to investigate the physiological and molecular alteration in the mice subject after 8 weeks of gavage intervention. The supplementation of coconut milk did not affect the levels of serum triglyceride, but it induced the total serum cholesterol after 2 weeks of treatment. The serum cholesterol level subsequently plateaued, but an increase in bile acid excretion was observed, most likely through the modulation of bile regulating genes, i.e. farnesoid X receptor (Fxr) and Cyp7a1. Despite that, the total cholesterol to HDL cholesterol ratio of coconut milk group was comparable to that of the light cream group. In short, coconut milk supplementation promoted cholesterol excretion through the fecal bile route but did not significantly improve the serum cholesterol profile of C57BL/6 mice.
Basic Clinical Examination of the Foot and Ankle
Authors: Kehrer Michael , Kohlhof Hendrik , Schwetje Desiree , Kasapovic Adnan , Kehrer Andreas , Wirtz Dieter Christian , Friedrich Max J.
Published: September 2020

Successful treatment of foot and ankle diseases requires an accurate diagnosis. In addition to differentiated history taking, clinical examination is the most important component in the diagnosis of foot and ankle diseases. The present video explains the common provocation tests and functional tests that are used in the basic clinical examination of the foot and ankle complex. In addition to general inspection and palpation, the focus is on different diagnostic tests and clinical signs that improve diagnostic accuracy. The present basic clinical examination methods allow a structured approach to clinical issues and can be a good basis, if supplemented by further specific and individual tests.
Auswirkungen von Bewegung auf die Gesundheit
Authors: Miko Hans-Christian , Zillmann Nadine , Ring-Dimitriou Susanne , Dorner Thomas Ernst , Titze Sylvia , Bauer Robert
Published: September 2020

Regelmäßige Bewegung trägt sowohl zum Erhalt als auch
zur Verbesserung des Gesundheitszustandes bei und ist für die
menschliche Entwicklung über die gesamte Lebensspanne des Menschen
wichtig. Starke Evidenz hinsichtlich der positiven Auswirkung
körperlicher Aktivität auf die Gesundheit liegt in den
Bereichen Gesamtsterblichkeit, Krebserkrankungen, Herz-Kreislaufgesundheit,
muskuloskelettale Gesundheit, Stoffwechselgesundheit sowie neurokognitive
Gesundheit vor. Körperliche Aktivität umfasst jede Form von
Bewegung, bei der durch die Kontraktion der Skelettmuskulatur eine
Erhöhung des Energieverbrauchs erzielt wird. Sie wird über
die Belastungskomponenten Häufigkeit, Dauer, Intensität und
Wochenumfang quantifiziert und gesteuert. Als gesundheitswirksame
körperliche Aktivität werden all jene Bewegungsformen
bezeichnet, welche die Gesundheit verbessern und bei denen das
Verletzungsrisiko gering ist. In den Österreichischen
Bewegungsempfehlungen werden ausdauerorientierte Bewegung, Krafttraining und
Koordinationsübungen empfohlen. Training nimmt innerhalb der
gesundheitswirksamen körperlichen Aktivität eine
Sonderstellung ein. Es zielt darauf ab, Anpassungsvorgänge im
Körper in Gang zu setzen, um Körperfunktionen zu verbessern.
Dabei muss die Aktivität an die unterschiedliche individuelle
Leistungsfähigkeit, das Aktivitätsniveau und das Alter
angepasst und nach bestimmten Grundsätzen durchgeführt
werden. Durch das Training kommt es zu einer positiven Veränderung
physiologischer Parameter, die wiederum in enger Verbindung mit einer
Verbesserung des Gesundheitszustandes steht. Durch
regelmäßige ausdauerorientierte und
muskelkräftigende Bewegung werden weitreichende Gesundheitseffekte
erzielt. Dennoch kann es bei der Ausführung zu unerwünschten
Ereignissen kommen. Hiervon betroffen sind v. a. der Bewegungsapparat und
das Kreislaufsystem. Durch adäquate Vorbereitung, passende
Ausrüstung und richtige Ausübung wird jedoch nicht nur der
persönliche, sondern auch der gemeinschaftliche Gesundheitsnutzen
durch Bewegung und Sport gesteigert.
Is There a Role for Cartilage Imaging in Athletes?
Authors: Yamamoto Asako , Levine Benjamin D. , Padron Mario , Chung Christine B.
Published: September 2020

This article reviews implications for cartilage imaging in athletes in the setting of (1) acute chondral injury diagnosis, (2) evaluation and follow-up of conservative and surgical therapy, and (3) evaluation of cartilage as a surrogate for meniscal function and joint stability. Focal knee cartilage defects are common in athletic populations. Athletes with articular cartilage injury may initially be able to return to sport with conservative therapy; however, a reduction of athletic ability and progression to osteoarthritis is expected in athletes with untreated severe chondral injury. For diagnostic and pre- and postsurgical evaluation purposes, morphological magnetic resonance (MR) assessment of the articular cartilage with high-resolution protocols is crucial. Although not widely implemented for clinical use, compositional MR techniques have great potential for monitoring the development and progression of biochemical and microstructural changes in cartilage extracellular matrix before gross morphological changes occur.
Sports Imaging of Team Handball Injuries
Authors: Fritz Benjamin , Parkar Anagha P. , Cerezal Luis , Storgaard Morten , Boesen Mikael , Åström Gunnar , Fritz Jan
Published: September 2020

Team handball is a fast high-scoring indoor contact sport with > 20 million registered players who are organized in > 150 federations worldwide. The combination of complex and unique biomechanics of handball throwing, permitted body tackles and blocks, and illegal fouls contribute to team handball ranging among the four athletic sports that carry the highest risks of injury. The categories include a broad range of acute and overuse injuries that most commonly occur in the shoulder, knee, and ankle. In concert with sports medicine, physicians, surgeons, physical therapists, and radiologists consult in the care of handball players through the appropriate use and expert interpretations of radiography, ultrasonography, CT, and MRI studies to facilitate diagnosis, characterization, and healing of a broad spectrum of acute, complex, concomitant, chronic, and overuse injuries. This article is based on published data and the author team's cumulative experience in playing and caring for handball players in Denmark, Sweden, Norway, Germany, Switzerland, and Spain. The article reviews and illustrates the spectrum of common handball injuries and highlights the contributions of sports imaging for diagnosis and management.
Image-guided Sports Medicine and Musculoskeletal Tumor Interventions: A Patient-Centered Model
Authors: Dalili Danoob , Isaac Amanda , Rashidi Ali , Åström Gunnar , Fritz Jan
Published: September 2020

The spectrum of effective musculoskeletal (MSK) interventions is broadening and rapidly evolving. Increasing demands incite a perpetual need to optimize services and interventions by maximizing the diagnostic and therapeutic yield, reducing exposure to ionizing radiation, increasing cost efficiency, as well as identifying and promoting effective procedures to excel in patient satisfaction ratings and outcomes. MSK interventions for the treatment of oncological conditions, and conditions related to sports injury can be performed with different imaging modalities; however, there is usually one optimal image guidance modality for each procedure and individual patient. We describe our patient-centered workflow as a model of care that incorporates state-of-the-art imaging techniques, up-to-date evidence, and value-based practices with the intent of optimizing procedural success and outcomes at a patient-specific level. This model contrasts interventionalist- and imaging modality-centered practices, where procedures are performed based on local preference and selective availability of imaging modality or interventionalists. We discuss rationales, benefits, and limitations of fluoroscopy, ultrasound, computed tomography, and magnetic resonance imaging procedure guidance for a broad range of image-guided MSK interventions to diagnose and treat sports and tumor-related conditions.
Gel Phantom Models for Radiofrequency and Microwave Ablation of the Liver
Authors: Chen Willa J. , Wang Qi , Kim Charles Y.
Published: September 2020

Heat-based percutaneous thermal ablation techniques have emerged as popular and effective treatments for liver cancer. As the technology continues to evolve, there is a need for optimized methods for experimentation to identify advantageous modifications and developments. Given that assessing and comparing resulting ablation zones in animal models are costly and resource-intensive, in vitro gel phantom models can serve an important role for early-stage experimentation. There exist several gel phantom recipes that have been reported in the literature. In this review, we will review the various recipes, the pros and cons to the existing models, and future potential directions.
Serpins, New Therapeutic Targets for Hemophilia
Authors: Aymonnier Karen , Kawecki Charlotte , Arocas Véronique , Boulaftali Yacine , Bouton Marie Christine
Published: September 2020

Hemostasis is a tightly regulated process characterized by a finely tuned balance between procoagulant and anticoagulant systems. Among inherited hemostatic conditions, hemophilia is one of the most well-known bleeding disorders. Hemophilia A (HA) and B (HB) are due to deficiencies in coagulation factor VIII (FVIII) or FIX, respectively, leading to unwanted bleeding. Until recently, hemophilia treatment has consisted of prophylactic replacement therapy using plasma-derived or recombinant FVIII in cases of HA or FIX in cases of HB. Because FVIII and FIX deficiencies lead to an imbalance between procoagulant and anticoagulant systems, a recent upcoming strategy implies blocking of endogenous anticoagulant proteins to compensate for the procoagulant factor deficit, thus restoring hemostatic equilibrium. Important physiological proteins of the anticoagulant pathways belong to the serpin (serine protease inhibitor) family and, recently, different experimental and clinical studies have demonstrated that targeting natural serpins could decrease bleeding in hemophilia. Here, we aim to review the different, recent studies demonstrating that blocking serpins such as antithrombin, protein Z-dependent protease inhibitor, and protease nexin-1 or modifying a serpin like α1-antitrypsin could rebalance coagulation in hemophilia. Furthermore, we underline the potential therapeutic use of serpins for the treatment of hemophilia.
Effect of magnetic field on the lateral interaction of plasma plumes
Authors: Mondal Alamgir , Singh R. K. , Chaudhari Vishnu , Joshi H. C.
Published: September 2020

Lateral interaction between two geometrically modified plasma plumes in the presence of a transverse magnetic field has been investigated. Characteristic behavior of both seed plumes and the interaction region in the presence of the field is compared with those for the field free case. Contrary to the field free case, no sharp interaction zone is observed; rather large enhancement in emission intensities in both seed and interaction regions is observed in the case of a magnetic field. The observed results are explained on the basis of atomic analysis of the spectral lines from the interaction region of the interacting plumes. The physical processes responsible for higher electron temperature and increased ionic line emission from singly as well as doubly ionized aluminum are briefly discussed.
Toward quantum efficiency enhancement of kesterite nanostructured absorber: A prospective of carrier quantization effect
Authors: Sravani L. , Routray S. , Pradhan K. P.
Published: September 2020

In this work, the carrier confinement mechanism through nanostructures is studied in a copper-zinc-tin-sulfide/Cu2ZnSnSe4-type kesterite material, resulting in a remarkable performance enhancement of solar cells. The effect of the quantized energy band, recombination rate, and escape mechanism on the spectral response of solar cells is explored in detail. The mathematical model for carrier dynamics and performance measuring parameters are analyzed and optimized. Moreover, the number of quantum wells is incorporated gradually up to 100 and the corresponding performances are explored. It is observed that with the increase in the number of wells, photogenerated current density enhances significantly up to a saturation point and then deteriorates. A remarkable efficiency of 24.8% and more than 80% of quantum efficiency are achieved from 50 numbers of quantum wells with 79.8% of fill factor.
Comment on “A reference-free clustering method for the analysis of molecular break-junction measurements” [Appl. Phys. Lett. 114, 143102 (2019)]
Authors: Hoxha Kevin P. , Reuter Matthew G.
Published: September 2020

We validate the utility of machine learning techniques for distinguishing different break junction configurations. Furthermore, we demonstrate that the different classes of traces can be mechanistically and independently analyzed, leading to additional physical insight into molecular conductance.
Local piezoelectric properties in Na-flux GaN bulk single crystals
Authors: Ueda A. , Hamachi T. , Okazaki A. , Takeuchi S. , Tohei T. , Imanishi M. , Imade M. , Mori Y. , Sakai A.
Published: September 2020

The local piezoelectricity of a Na-flux GaN crystal grown on a multipoint-seed-GaN template is investigated using piezoresponse force microscopy. The piezoresponse is critically dependent on two types of growth regions that are dominantly formed in the Na-flux GaN crystal: the c-growth sector (cGS), which is grown on top of the point-seed GaN surface with a growth front of (0001) planes, and the facet-growth sector (FGS), which is grown on the side of cGS with {101¯1} facets. Quantitative analyses reveal the GaN surface displacements at cGS that result from the piezoresponses increase with the applied AC voltage: the measured values well reflect the piezoelectric constant of d33 in GaN. The piezoresponses at the FGS and the boundary between the cGS and FGS are less sensitive than that at the cGS. A combination of cathodoluminescence and multiphoton excitation photoluminescence techniques clarifies that a local reduction of the piezoresponse observed in cGS is attributed to microscale FGSs that exist randomly in cGS. The dependence of the piezoresponse on the growth regions is quantitatively discussed from three possible viewpoints that potentially affect the polarization properties of GaN: residual strain, local crystallographic tilting, and inherent carrier distribution. As a result, a carrier screening effect is the most probable candidate to induce reduction of the piezoresponse in the FGSs of GaN crystals.
Temporal acoustic wave computational metamaterials
Authors: Lv Zengyao , Liu Peng , Pei Yongmao
Published: September 2020

Acoustic computational metamaterials have enabled the realization of mathematical operations in the spatial domain. Here, we present and experimentally demonstrate the time domain mathematical operations, such as fractional differentiation and integration and Gaussian filtering, based on a fully reconfigurable acoustic computational metamaterial. We also demonstrate the potential to achieve an integrated computing network in order to realize complicated functionalities by exploiting differentiation, integration, and their series and parallel functions in a simple acoustic metamaterial circuit. For generality and universality, the linearity and the product rule for the wave-based differentiation are also verified as well as the functionality of cascaded differentiators. We expect that acoustic computational metamaterials will enable capabilities in signal acquisition and processing and network computing and drive applications of sound waves.
Epitaxial niobium nitride superconducting nanowire single-photon detectors
Authors: Cheng Risheng , Wright John , Xing Huili G. , Jena Debdeep , Tang Hong X.
Published: September 2020

Superconducting nanowires used in single-photon detectors have been realized on amorphous or poly-crystalline films. Here, we report the first use of single-crystalline NbN thin films for superconducting nanowire single-photon detectors (SNSPDs). Grown by molecular beam epitaxy (MBE) at high temperature on nearly lattice-matched AlN-on-sapphire substrates, the NbN films exhibit a high degree of uniformity and homogeneity. Even with relatively thick films, the fabricated nanowire detectors show saturated internal efficiency at near-IR wavelengths, demonstrating the potential of MBE-grown NbN for realizing large arrays of on-chip SNSPDs and their integration with AlN-based χ(2) quantum photonic circuits.
Phase change interface stability during isochoric solidification of an aqueous solution
Authors: Zhao Yuanheng , Powell-Palm Matthew J. , Ukpai Gideon , Bilbao-Sainz Cristina , Chen Liubiao , Wang Junjie , Rubinsky Boris
Published: September 2020

The stability of solid–liquid interfaces during solidification is a physical phenomenon of fundamental interest with a wide range of practical applications, including the freezing of biological matter for medical and agricultural purposes. Much of the classical research in this field treats solidification in isobaric (constant-pressure) systems in which the phase transition typically occurs under constant atmospheric pressure. Recent research has found, however, that freezing in isochoric (constant-volume) systems in which the solidifying material is confined within a high-strength constant-volume chamber held at subfreezing temperatures gives rise to many atypical physical phenomena, and understanding of the solid–liquid interface behavior under isochoric conditions is currently lacking. In this work, we study the stability and propagation of the solid–liquid interface during isochoric freezing of aqueous solutions. Using a mathematical model of heat and mass transfer during solidification coupled with multiple criteria for predicting the emergence of interfacial instabilities based on temperature and concentration gradients in the phase transition region, we find that isochoric freezing significantly stabilizes the solid–liquid interface relative to isobaric freezing, suggesting the potential for extended growth of planar, non-dendritic interfaces.
Negative constant voltage stress-induced threshold voltage instability in hydrogen-terminated diamond MOSFETs with low-temperature deposited Al2O3
Authors: Chen Zhihao , Yu Xinxin , Zhou Jianjun , Mao Shuman , Fu Yu , Yan Bo , Xu Ruimin , Kong Yuechan , Chen Tangsheng , Li Yanrong , Xu Yuehang
Published: September 2020

Threshold voltage analysis can help reveal the reliability of semiconductor transistors and its underlying mechanism. Herein, negative constant voltage stress (NCVS)-induced threshold voltage instability is studied in hydrogen-terminated diamond metal-oxide-semiconductor field-effect transistors (HD MOSFETs) with an Al2O3 dielectric layer deposited via atomic layer deposition at 90 °C. An unusual bidirectional shift in threshold voltage (Vth) can be observed with time. When a weak gate NCVS is applied, Vth gradually decreases during the first 500 s but increases in the next 500 s. A similar but opposite phenomenon is observed when the HD MOSFETs are in a recovery stage upon removing the NCVS, i.e., Vth increases in the first 500 s but decreases in the next 4500 s. A kinetic hydrogen motion model shows that this phenomenon can be attributed to the larger characteristic time constant of the unactuated oxygen-dangling bonds (UODBs) compared to that of the traps in the gate dielectric. Consequently, the trapping effect dominates and decreases Vth at the onset of NCVS. After 500 s, the UODB effects can be observed, increasing Vth. In the recovery stage, Vth is larger than the initial value. Further, modified hydrogen kinetic equations accounting for the dynamic effects of UODBs and traps are provided to quantitatively analyze the results.
Hybrid-Vlasov modeling of three-dimensional dayside magnetopause reconnection
Authors: Pfau-Kempf Y. , Palmroth M. , Johlander A. , Turc L. , Alho M. , Battarbee M. , Dubart M. , Grandin M. , Ganse U.
Published: September 2020

Dayside magnetic reconnection at the magnetopause, which is a major driver of space weather, is studied for the first time in a three-dimensional (3D) realistic setup using a hybrid-Vlasov kinetic model. A noon–midnight meridional plane simulation is extended in the dawn–dusk direction to cover 7 Earth radii. The southward interplanetary magnetic field causes magnetic reconnection to occur at the subsolar magnetopause. Perturbations arising from kinetic instabilities in the magnetosheath appear to modulate the reconnection. Its characteristics are consistent with multiple, bursty, and patchy magnetopause reconnection. It is shown that the kinetic behavior of the plasma, as simulated by the model, has consequences on the applicability of methods such as the four-field junction to identify and analyze magnetic reconnection in 3D kinetic simulations.
Modeling nonlocal electron–phonon coupling in organic crystals using interpolative maps: The spectroscopy of crystalline pentacene and 7,8,15,16-tetraazaterrylene
Authors: Strong Steven E. , Hestand Nicholas J.
Published: September 2020

Electron–phonon coupling plays a central role in the transport properties and photophysics of organic crystals. Successful models describing charge- and energy-transport in these systems routinely include these effects. Most models for describing photophysics, on the other hand, only incorporate local electron–phonon coupling to intramolecular vibrational modes, while nonlocal electron–phonon coupling is neglected. One might expect nonlocal coupling to have an important effect on the photophysics of organic crystals because it gives rise to large fluctuation in the charge-transfer couplings, and charge-transfer couplings play an important role in the spectroscopy of many organic crystals. Here, we study the effects of nonlocal coupling on the absorption spectrum of crystalline pentacene and 7,8,15,16-tetraazaterrylene. To this end, we develop a new mixed quantum–classical approach for including nonlocal coupling into spectroscopic and transport models for organic crystals. Importantly, our approach does not assume that the nonlocal coupling is linear, in contrast to most modern charge-transport models. We find that the nonlocal coupling broadens the absorption spectrum non-uniformly across the absorption line shape. In pentacene, for example, our model predicts that the lower Davydov component broadens considerably more than the upper Davydov component, explaining the origin of this experimental observation for the first time. By studying a simple dimer model, we are able to attribute this selective broadening to correlations between the fluctuations of the charge-transfer couplings. Overall, our method incorporates nonlocal electron–phonon coupling into spectroscopic and transport models with computational efficiency, generalizability to a wide range of organic crystals, and without any assumption of linearity.
High-speed ultraviolet photodetectors based on 2D layered CuInP2S6 nanoflakes
Authors: Ma Ru-Ru , Xu Dong-Dong , Guan Zhao , Deng Xing , Yue Fangyu , Huang Rong , Chen Ye , Zhong Ni , Xiang Ping-Hua , Duan Chun-Gang
Published: September 2020

Although a lot of promising two-dimensional (2D) semiconductors with various bandgaps, represented by black phosphorus (0.3 eV), transition metal dichalcogenides (< 2 eV), and boron nitride (5 − 6 eV), have been extensively researched in photoelectronic and electronic devices, the spectrum of large bandgap materials is still very narrow, which limits the potential device applications in ultraviolet photodetection. The broad family of layered thio- and seleno-phosphates with wide and tunable bandgaps (1.3 − 3.5 eV) can complement the intermediate bandgaps from 1.6 to 4 eV, which can fill the gap between transition metal dichalcogenides and boron nitride. In this work, a high-performance ultraviolet photodetector based on multilayered CuInP2S6 was fabricated. It exhibits fast response times shorter than 0.5 ms, i.e., rise time ∼ 0.36 ms and fall time ∼ 0.44 ms for ultraviolet illumination (280 nm, 50 nW), which is superior than previously reported 2D layered-based UV detectors. Significantly, this photodetector also shows ultralow dark current (∼ 100 fA), a high on/off ratio (∼103), and a specific detectivity of 7.38 × 1010 Jones. Our results provide an excellent candidate for low power consumption and high-speed photodetection.
Spin-reorientation transition induced magnetic skyrmion in Nd2Fe14B magnet
Authors: Xiao Y. , Morvan F. J. , He A. N. , Wang M. K. , Luo H. B. , Jiao R. B. , Xia W. X. , Zhao G. P. , Liu J. P.
Published: September 2020

The easy axis of Nd2Fe14B is known to deviate from the c-axis when the temperature decreases to under the spin reorientation point TSR, 135 K. In this work, magnetic domain evolution in Nd2Fe14B was in situ observed by using Lorentz transmission electron microscopy at variable temperatures and magnetic fields. It appears that most inverse domains shrink to stripes and disappear suddenly to achieve the saturation state under a magnetic field, and the saturation field increases with the decreasing temperature due to the increased anisotropy. Magnetic bubbles with zero topological number are formed at temperatures higher than TSR, whereas magnetic skyrmions are found at temperatures around TSR due to the spin reorientation. The tunable anisotropy and saturation magnetization at TSR are the main causes of forming magnetic skyrmions. This finding exhibits the feasibility of generating skyrmions in the ordinary rare-earth permanent magnetic materials.
The complex viscosity of Möbius macromolecules
Authors: Piette Jourdain H. , Moreno Nicolas , Fried Eliot , Giacomin Alan Jeffrey
Published: September 2020

Using general rigid bead–rod theory, we explore the effect of twisting a macromolecule on its rheological properties in suspensions. We thus focus on macromolecules having the form of Möbius bands so that the number of twists can be incremented. We call these Möbius macromolecules. When represented in general rigid bead–rod theory, these macromolecules comprise beads whose centers all fall on a Möbius band. From first principles, we calculate the complex viscosity of twisted rings with zero to seven twists. We find that the zero-shear values of the viscosity and first normal stress coefficient increase with twisting. Furthermore, we find that the real part of the complex viscosity descends more rapidly, with frequency, with extent of twist. For the imaginary part of the complex viscosity, the more twisted, the higher the peak. For each part of the dimensionless complex viscosity and the first normal stress coefficient, the results fall on one of just three curves corresponding to zero, even, or odd numbers of twists. We also explore the effects of the length and the aspect ratio of twisted macromolecular suspensions. We close with a worked example for a suspension of triply twisted Möbius annulene.
Investigation of the process of mixing reagents in the laser chamber of active medium generators of continuous-wave chemical lasers with promising nozzle arrays
Authors: Avdeev A.V. , Katorgin B.I.
Published: September 2020

It is shown that the use of a toothed nozzle array in the active medium generator (AMG) of continuous-wave chemical lasers (CWCLs) allows more efficient mixing of reagents to be achieved in the laser chamber than in an AMG with a slit nozzle array. The results of calculations of parameters of the active medium of a DF CWCL operating in the gain regime for the AMG with traditional and promising nozzle array designs are presented. A kinetic model of processes in the DF CWCL active medium is proposed, which allows obtaining a good agreement with the results of measurements of the small-signal gain.
Broadband fibre-pigtailed acousto-optic frequency shifter
Authors: Mazur M.M. , Mazur L.I. , Ryabinin A.V. , Shorin V.N.
Published: September 2020

A two-crystal fibre-pigtailed acousto-optic frequency shifter has been developed and investigated. An optimal configuration of acousto-optic cells is chosen. A two-crystal acousto-optic frequency shifter of 785-nm laser radiation in the range from 156 to 196 MHz, with single-mode polarisation maintaining fibres at the input and output, is described. Some recommendations are given how to improve the shifter transmission coefficient and increase the frequency shift range.
Acousto-optic modulators of high-power laser radiation on the basis of KGW and KYW crystals
Authors: Mazur M.M. , Mazur L.I. , Sirotkin A.A. , Ryabinin A.V. , Shorin V.N.
Published: September 2020

Different modifications of acousto-optic modulators (AOMs) based on KG(WO4)2 (KGW) and KY(WO4)2 (KYW) crystals, designed for Q switching of high-power pulsed lasers, is developed and investigated. It is shown that AOMs based on these crystals are universal, can be combined with different lasers in the wavelength range of 1 – 3 μm, and have a high radiation resistance in the absence of antireflection coatings and light input at Brewster’s angle. The operation efficiency of KGW-based AOMs is experimentally demonstrated. Solid-state lasers based on Cr : Er : YSGG (λ = 2.78 μm), Cr : Yb : Ho : YSGG (λ = 2.87 μm), Cr : Tm : Ho : YSGG (λ = 2.09 μm), and Nd : YAG (λ = 1.064 μm) crystals with active acousto-optic Q switching, operating in the repetitively pulsed regime with a high beam quality and without surface destruction, are investigated. Lasing pulses (30 – 60)-ns long with energy up to 32 mJ at a repetition rate from 1 to 1000 Hz are obtained.
The ED2GP (emergency department to general practice) for Women study: understanding lower follow-up rates among older women
Authors: Hanna Shaddy , Tam Chun Wah Michael , Knight Andrew , Zhao Linheng , Ban Lucille , Pellizzon Belinda , Parks James
Published: September 2020

Older women seem to have lower GP follow-up rates after an emergency department (ED) discharge than men. This qualitative study investigated how older women seek GP follow up after an ED visit. In 2018, women aged ≥65 years were recruited from an ED in a suburban hospital in south-western Sydney, Australia, and then contacted 1 week later for a telephone interview exploring factors associated with their follow-up behaviour. Grounded theory was used to construct a potential explanatory model of follow-up behaviours. Of the 100 women recruited, 64% had attended a GP follow up by Day 7, as instructed. The balance of perceived cost and benefit of GP follow up emerged as a useful model to understand the factors affecting follow-up behaviour. Perceived costs included inconvenience caused to self and others, access to transport options and the availability of a patient’s GP. Perceived benefits included previous experiences with the healthcare system, pre-existing health-seeking behaviours and ED messaging. Our findings suggest that follow-up rates could be improved by strengthening the perceived benefit of GP follow up at the point of ED discharge, in addition to addressing perceived costs. Approaches may include ensuring discharge instructions are purposeful and given in the company of an older woman’s social supports.
The acquisition of conceptual metaphors in Mandarin Chinese
Authors: Gong Shu-Ping
Published: September 2020

This study aimed to determine whether learners of Chinese as a Second Language (CSL) could more easily acquire Mandarin metaphors in vocabulary acquisition, reading comprehension, and essay writing tasks after enhancing their metaphor awareness. Experiment 1 divided CSL participants into three groups and received three types of instructions on metaphors. The results showed that there was no effect of enhanced metaphor awareness across the three kinds of instructions in the vocabulary, reading, and writing tasks, while a marginally significant effect of enhanced metaphor awareness in the writing task. Experiment 2 aimed to determine whether the discourse-based or the sentence-based presentation of metaphorical expressions would affect the CSL learners’ writing performance. The results showed that the paragraph group achieved significantly higher writing scores and frequency of metaphors produced compared with the sentence group. And, the paragraph group produced more new and creative metaphors in their essays compared with the sentence group. To conclude, the two experiments demonstrated that enhancing the CSL learners’ metaphor awareness was beneficial in the writing tasks, but not in the vocabulary and reading tasks. Furthermore, when the metaphorical expressions were presented in discourse to facilitate the connection of semantic relationships between metaphors, this resulted in more coherent essays. This study has practical implications for CSL teachers designing classroom activities involving the learning of Chinese metaphors.
Changes in L2 pronunciation
Authors: Levis John
Published: September 2020

This special issue revisits an extraordinarily influential paper for L2 pronunciation research and teaching (Munro & Derwing, 1995) by looking again at the original paper with new eyes and new analyses. The
special issue also includes invited papers addressing current approaches based on the three key constructs in Munro and Derwing (1995): Intelligibility, comprehensibility, and accentedness. Papers in the issue include a
reconsideration of the Intelligibility and Nativeness principles from Levis (2005), applications
of the constructs to L2 Spanish (Nagle & Huensch), a consideration of how everyday L2 use affects comprehensibility (Zielinski &
Pryor), long-term effects of intensive instruction (French, Gagné & Collins), influences on listener reaction to L2 speech (Isaacs &
Thomson), empirical evidence for the dynamic nature of comprehensibility (Trofimovich et al.), a study on ELF intelligibility and functional
load considerations (Thir), the relationship between comprehensibility and social evaluation of speech (Vaughn & Whitty), and one book
review.
Lee-Wald charge and asymptotic behaviors of the Weyl-invariant topologically massive gravity
Authors: Dengiz Suat , Kilicarslan Ercan , Setare M Reza
Published: September 2020

We apply the Lee–Wald covariant phase space method to the Weyl-invariant topologically massive gravity and compute the corresponding on-shell conserved charges. By using appropriate decay conditions for the existing propagating modes in the near-horizon of a stationary black hole, we obtain the charges generating the asymptotic symmetries. We show that the charges are integrable and the (modified) algebras among the asymptotic generators are closed for the certain choice of central extensions.
From a bounce to the dark energy era with F(R) gravity
Authors: Odintsov S D , Oikonomou V K , Paul Tanmoy
Published: September 2020

In this work we consider a cosmological scenario in which the Universe contracts initially having a bouncing-like behavior, and accordingly after it bounces off, it decelerates following a matter dominated (MD) like evolution and at very large positive times it undergoes through an accelerating stage. Our aim is to study such evolution in the context of F(R) gravity theory, and confront quantitatively the model with the recent observations. Using several reconstruction techniques, we analytically obtain the form of F(R) gravity in two extreme stages of the Universe, particularly near the bounce and at the late time era respectively. With such analytic results and in addition by employing appropriate boundary conditions, we numerically solve the F(R) gravitational equation to determine the form of the F(R) for a wide range of values of the cosmic time. The numerically solved F(R) gravity realizes an unification of certain cosmological epochs of the Universe, in particular, from a non-singular bounce to a MD epoch and from the MD to a late time dark energy (DE) epoch. Correspondingly, the Hubble parameter and the effective equation of state (EoS) parameter of the Universe are found and several qualitative features of the model are discussed. The Hubble radius goes to zero asymptotically in both sides of the bounce, which leads to the generation of the primordial curvature perturbation modes near the bouncing point, because at that time, the Hubble radius diverges and the relevant perturbation modes are in sub-Hubble scales. Correspondingly, we calculate the scalar and tensor perturbations power spectra near the bouncing point, and accordingly we determine the observable quantities like the spectral index of the scalar curvature perturbations, the tensor-to-scalar ratio, and as a result, we directly confront the present model with the latest Planck observations. Furthermore the F(R) gravity DE epoch is confronted with the Sne-Ia + BAO + H(z) + CMB data.
A variety of Levitrons: a review
Authors: Michaelis Max , Bingham Bob , Charlton Mike , Isaac C Aled
Published: September 2020

After a brief history and critique of some older instruments, several new Levitron geometries are described. As a result of their greater stability these devices can be used as analogues of a number of phenomena and applications, including magnetic resonance techniques, atom traps and accelerator rings. In particular, the notion of the spinning magnet (or spignet) in a linear trap is similar to the mechanism underpinning the confinement of antihydrogen in a magnetic minimum trap, as achieved in experiments at CERN.
Study of the electric field in a diffuse nanosecond positive ionization wave generated in a pin-to-plane geometry in atmospheric pressure air
Authors: Bourdon Anne , Péchereau François , Tholin Fabien , Bonaventura Zdenek
Published: September 2020

The dynamics of a nanosecond positive ionization front generated in a pin-to-plane geometry in atmospheric pressure air is simulated using a 2D axisymmetric drift-diffusion fluid model. For a 16 mm gap and a sharp pin electrode, the plateau of the applied voltage is varied between 40 and 60 kV and the rise time is varied between 0.5 and 1.5 ns or a DC voltage is applied. The discharge ignition time and the voltage at ignition are shown to depend mostly on the voltage rise time. The connection time, i.e. the time for the ionization wave to ignite, propagate and connect to the plane is shown to strongly depend on both the values of the voltage plateau and rise time. For all cases, the discharge has a conical shape with a maximal radius of about 8 mm as it connects to the grounded plane. The average propagation velocity of the ionization front is found to vary in the range 3.1 to 8.5 mm ns−1. These values are in rather good agreement with experiments. Temporal evolutions of the electric field are recorded on the symmetry axis at different positions in the gap. At each location, an increase and decrease of the electric field is observed as the ionization front, propagating from the pin to the plane, passes the studied point, in accordance with experimental observations. Finally, for a voltage plateau of 55 kV and a rise time of 0.5 ns, a temporal sampling of 100 ps is shown to be sufficient to capture the dynamics of the electric field during the ionization front propagation when it passes close to the middle of the gap. Conversely, a temporal sampling of 10 ps is required when the ionization wave is close to both electrodes, or during the fast redistribution of the electric field after the connection of the ionization front at the cathode.
Inclusive and effective bulk viscosities in the hadron gas
Authors: Rose J-B , Torres-Rincon J M , Elfner H
Published: September 2020

We estimate the temperature dependence of the bulk viscosity in a relativistic hadron gas. Employing the Green–Kubo formalism in the SMASH (Simulating Many Accelerated Strongly-interacting Hadrons) transport approach, we study different hadronic systems in increasing order of complexity. We analyze the (in)validity of the single exponential relaxation ansatz for the bulk-channel correlation function and the strong influence of the resonances and their lifetimes. We discuss the difference between the inclusive bulk viscosity of an equilibrated, long-lived system, and the effective bulk viscosity of a short-lived mixture like the hadronic phase of relativistic heavy-ion collisions, where the processes whose inverse relaxation rate are larger than the fireball duration are excluded from the analysis. This clarifies the differences between previous approaches which computed the bulk viscosity including/excluding the very slow processes in the hadron gas. We compare our final results with previous hadron gas calculations and confirm a decreasing trend of the inclusive bulk viscosity over entropy density as temperature increases, whereas the effective bulk viscosity to entropy ratio, while being lower than the inclusive one, shows no strong dependence to temperature.
Measurements of anisotropic g-factors for electrons in InSb nanowire quantum dots
Authors: Mu Jingwei , Huang Shaoyun , Wang Ji-Yin , Huang Guang-Yao , Wang Xuming , Xu H Q
Published: September 2020

We have measured the Zeeman splitting of quantum levels in few-electron quantum dots (QDs) formed in narrow bandgap InSb nanowires via the Schottky barriers at the contacts under application of different spatially orientated magnetic fields. The effective g-factor tensor extracted from the measurements is strongly anisotropic and level-dependent, which can be attributed to the presence of strong spin–orbit interaction (SOI) and asymmetric quantum confinement potentials in the QDs. We have demonstrated a successful determination of the principal values and the principal axis orientations of the g-factor tensors in an InSb nanowire QD by the measurements under rotations of a magnetic field in the three orthogonal planes. We also examine the magnetic field evolution of the excitation spectra in an InSb nanowire QD and extract a SOI strength of

Δ

s
o

∼ 180 μeV from an avoided level crossing between a ground state and its neighboring first excited state in the QD.
Polarization-insensitive broadband visible-light steering with tunable direction enabled by scalable plasmonics meta-gratings
Authors: Wan Chengwei , Dai Chenjie , Wan Shuai , Yang Rui , Shi Yangyang , Li Zhongyang
Published: September 2020

As an emerging field in the discipline of optics, plasmonics and metasurfaces have been demonstrated to enable a new degree of freedom to manipulate light for arbitrary beam steering, spectral splitting as well as precise wavefront shaping. However, it has been mostly studied in parallel with the field of diffractive optics, and awaits the unveiling of how the hybridizations between plasmonic effect and diffraction effect interact and impact. Here, we have theoretically proposed a new type of polarization-insensitive meta-grating structure across the broadband visible regime. The structure design combines the width gradient (critical resonant length) from a trapezoid-nanoantenna with the height gradient from a blazed grating profile. The hybridized meta-grating creates both plasmonic effect and grating effect, which enables all the optical incident photons to be directed to the same orientation regardless of the light polarization. As we know, both metasurfaces and diffractive optical elements (such as gratings) are, more often than not, quite sensitive to the incident light polarization. Moreover, if placing our meta-grating on a flexible/stretchable substrate (such as polydimethylsiloxane), the outgoing angle can be effectively adjusted by tuning the period or density of meta-grating arrays. Such meta-grating architectures can be potentially manufactured by existing photolithography and nanoimprint techniques, and can easily find a wide range of practical polarization-insensitive applications, including broadband deflector and emitter, tunable display and imaging device, high signal-to-noise ratio spectrometer, polarization-insensitive plasmonic coupler, etc.
Content representations to support out-of-field physics teachers
Authors: Carpendale Jared , Hume Anne
Published: September 2020

A global shortage of qualified physics teachers requires some teachers to teach physics out-of-field (OOF). A concern for OOF physics teaching is that without appropriate physics content knowledge (CK), these teachers tend to focus on rote learning and may find it difficult to support students who require additional assistance or extension; they tend to teach in ways that do not foster conceptual understanding. This paper reports on research that investigated how content representations (CoRes) could be used to support OOF physics teachers’ knowledge for teaching electricity and magnetism. CoRes were used to elicit discussions between OOF and in-field physics teachers about important teaching and learning considerations (e.g. appropriate CK for students and appropriate instructional strategies for promoting conceptual understanding). Prior to engaging with CoRes, three OOF teachers were interviewed about teaching electricity and magnetism and their lessons during this topic were video recorded. Later, as these OOF teachers worked with their in-field colleagues using the CoRe framework, all discussions were audio recorded. To explore changes to the OOF teachers’ knowledge and practice from the CoRe process, they were interviewed and their follow-up electricity and magnetism lessons (for a different class) were video recorded. Findings showed that the CoRe processstimulated important discussions about teaching electricity and magnetism and considerations for students learning this topic. As a result, the OOF teachers developed their professional knowledge, including refinement of their CK, acquirement of new topic-specific instructional strategies, and more awareness of students’ understanding during lessons. This study concludes that CoRes are an effective strategy for supporting the professional learning of OOF physics teachers.