bluuebunny/crossref_metadata_2025 huggingface dataset:
Angular momentum transport by magnetoconvection and the magnetic modulation of the solar differential rotation
Authors: Rüdiger G. , Küker M.
Published: April 2021

In order to explain the variance of the solar rotation law during the activity minima and maxima, the angular momentum transport by rotating magnetoconvection is simulated in a convective box penetrated by an inclined azimuthal magnetic field. Turbulence-induced kinetic and magnetic stresses and the Lorentz force of the large-scale magnetic background field are the basic transporters of angular momentum. Without rotation, the sign of the magnetic stresses naturally depends on the signs of the field components as positive (negative) BθBϕ transport the angular momentum poleward (equatorward). For fast enough rotation, however, the turbulence-originated Reynolds stresses start to dominate the transport of the angular momentum flux. The simulations show that positive ratios of the two meridional magnetic field components to the azimuthal field reduce the inward radial as well as the equatorward latitudinal transport, which result from hydrodynamic calculations. Only for BθBϕ > 0 (generated by solar-type rotation laws with an accelerated equator) does the magnetic-influenced rotation at the solar surface prove to be flatter than the nonmagnetic profile together with the observed slight spin-down of the equator. The latter phenomenon does not appear for antisolar rotation with polar vortex as well as for rotation laws with prevailing radial shear.
Can we identify wild-born salmon from parentage assignment data? A case study in the Garonne-Dordogne rivers salmon restoration programme in France
Authors: Vandeputte Marc , Bestin Anastasia , Fauchet Louarn , Allamellou Jean-Michel , Bosc Stéphane , Menchi Olivier , Haffray Pierrick
Published: April 2021

Parentage assignment with genomic markers provides an opportunity to monitor salmon restocking programs. Most of the time, it is used to study the fate of hatchery-born fish in those programs, as well as the genetic impacts of restocking. In such analyses, only fish that are assigned to their parents are considered. In the Garonne-Dordogne river basin in France, native salmon have disappeared, and supportive breeding is being used to try to reinstate a self-sustained population. It is therefore of primary importance to assess the numbers of wild-born returning salmon, which could appear as wrongly assigned or not assigned, depending on the power of the marker set and on the size of the mating plan. We used the genotypes at nine microsatellites of the 5800 hatchery broodstock which were used from 2008 to 2014, and of 884 upstream migrating fish collected from 2008 to 2016, to assess our ability to identify wild-born salmon. We simulated genotypes of hatchery fish and wild-born fish and assessed how they were identified by the parentage assignment software Accurassign. We showed that 98.7% of the fish assigned within the recorded mating plan could be considered hatchery fish, while 93.3% of the fish in other assignment categories (assigned out of the mating plan, assigned to several parent pairs, not assigned) could be considered wild-born. Using a Bayesian approach, we showed that 31.3% of the 457 upstream migrating fish sampled from 2014 to 2016 were wild-born. This approach is thus efficient to identify wild-born fish in a restoration program. It remains dependent on the quality of the recording of the mating plan, which we showed was rather good (<5% mistakes) in this program. To limit this potential dependence, an increase in the number of markers genotyped (17 instead of 9) is now being implemented.
Âge et genèse de la coupole granitique à métaux rares (Sn, Li, Nb-Ta, W) de Montebras (Creuse, Massif central français)
Authors: Marcoux Éric , Barré Benjamin , Pichavant Michel , Poujol Marc
Published: April 2021

La coupole de Montebras est un petit massif de granite à métaux rares (Sn, W, Li, Nb-Ta) situé au nord du Massif Central Français qui se met en place au Carbonifère supérieur dans un encaissant plus ancien, le granite de Chanon (357,2 ± 2,1 Ma). Deux épisodes magmatiques, un microgranite (316,1 ± 4,3 Ma) et un leucogranite albitique (309,8 ± 3,9 Ma), sont distingués. Le second développe à son toit des formations de contact, notamment une puissante pegmatite stockscheider (309,7 ± 4,5 Ma), passant vers l’est à des greisens à lithium et des filons plats de quartz stannifères anciennement exploités (303,8 ± 4,8 Ma). Le dépôt de cassitérite (associée à la manganocolumbite) s’étale depuis la phase magmatique avec des cristaux disséminés dans le leucogranite, jusqu’à la fin de la phase pneumatolytique marquée par des filons de quartz stannifères. Cet étalement se traduit par une baisse progressive des concentrations en éléments-traces (Nb, Ta, Fe, Mn, Mg, Ti) dans la cassitérite mais sans que soit atteint le domaine des compositions typiquement hydrothermales. Lors de la phase pneumatolytique, la cassitérite est accompagnée de rare scheelite, de la rarissime qitianlingite et d’une wolframite fréquente dont la composition (hübnérite) indique une origine magmatique pour le métal et les fluides impliqués dans le dépôt du tungstène. La paragenèse à sulfures riches en Cu, As et Sn (löllingite, chalcopyrite, tennantite, stannoïdite, mawsonite…) marque le passage à la phase hydrothermale et suggère une origine dans les roches encaissantes pour le cuivre et l’arsenic. L’événement fluo-barytique liasique se manifeste par l’apparition locale de fissures à fluorine violette, barytine et manganapatite. La coupole de Montebras fournit un exemple représentatif des granites à métaux rares de la chaîne varisque. Elle est contemporaine des autres magmas granitiques à éléments rares du nord Massif central avec lesquels elle présente des points de similitude mais aussi des différences. Sa mise en place pourrait relever d’un mécanisme de type cauldron subsidence.
Optimal design to control rotor shaft vibrations and thermal management on a supercritical CO2 microturbine
Authors: Li Jun , Gurgenci Hal , Li Jishun , Li Lun , Guan Zhiqiang , Yang Fang
Published: April 2021

Supercritical carbon dioxide (SCO2) Brayton cycle microturbine can be used for the next generation of solar power. In order to comprehensively optimize the supporting system and cooling device parameters of Brayton cycle shafting, the concept of chaos interval is introduced by chaotic mapping, and the CIMPSO algorithm is proposed to optimize the multi-objective rotor system model with nonlinear variables.The results show that the resonance amplitude of the optimized model is effectively attenuated, and the critical speed point is far away from the working speed, which shows the robustness of the optimization algorithm. Finally, based on arbitrary several sets of optimization solutions and empirical parameters, the finite element model of shafting is established for simulation, and the results show that the optimized solution has certain guiding significance for the design of the rotor system.The cooling device is designed and simulated by CFD method based on the optimal solution set. Both the inlet boundary conditions of given pressure (1 MPα) and given mass flow rate (0.1 kg/s) numerical calculations were carried out to characterize the cooling performance, for different jet impingement configurations (Hr/din = 0.0125 ∼ 5).Several sets of analyses show the strong effects of the jet-to-target spacing (Hr/din) on the rotor thermal performance at a given diameter (din) of the nozzle. Average temperature (Tc) at the free end of the rotor show that, as jet-to-target distance decreases (0.0125 ≤ Hr/din ≤ 0.33), the heat dissipation efficiency of the cooling device with the given pressure boundary condition tends to decrease, while the conclusion is opposite when the inlet boundary condition is set to the given mass flow rate. And there is an interval for the optimal combination (Hr/din) to promote the cooling efficiency.
Target animal safety evaluation of a novel topical combination of esafoxolaner, eprinomectin and praziquantel for cats
Authors: Gupta Aradhana , Baker Christine , Wang Hailun , Targa Norba , Pfefferkorn Anthony , Tielemans Eric
Published: April 2021

The safety profile of NexGard®Combo, a novel topical product for cats combining esafoxolaner, eprinomectin and praziquantel, for the treatment and prevention of internal and external parasites, was evaluated in kittens, in two margin-of-safety studies (Studies #1 and #2), and in an oral tolerance study (Study #3). In the margin of safety studies, kittens were dosed several times topically with multiples of the maximum exposure dose (1×): in Study #1, 3× and 5× doses four times at 2-week intervals; in Study #2, 1×, 3× and 5× doses six times at 4-week intervals. In Study #3, kittens were dosed orally once with a 1× dose. Furthermore, in Study #1, another group of kittens was dosed topically twice at a 4-week interval with a formulation of esafoxolaner as the sole active ingredient dosed at 23×. Physical examinations and clinical pathology analyses were performed throughout the studies, followed by necropsy and detailed histopathological evaluation in Studies #1 and #2. No significant treatment related effects were observed in the three studies, except for one occurrence of reversible neurological signs attributed to eprinomectin in one cat after the third 5× dose in Study #2, with clinical signs observed nine hours after dosing, pronounced for a few hours, significantly improved the next day, and absent 2 days after dosing. In conclusion, NexGard®Combo was demonstrated safe in kittens following repeated topical administrations and following oral ingestion, and very high topical doses of esafoxolaner were well tolerated.
Safety evaluation of a novel topical combination of esafoxolaner, eprinomectin and praziquantel, in reproducing female cats
Authors: Tielemans Eric , Erasmus Heidi , Momberg Mandie , Pfefferkorn Anthony , Targa Norba , Chilakapati Jaya , Gupta Aradhana
Published: April 2021

NexGard® Combo, a novel topical endectoparasiticide product for cats, is a combination of esafoxolaner, eprinomectin and praziquantel. The safety of this novel combination administered to females during reproduction and lactation was evaluated per analysis of breeding parameters and adverse reactions observed on females and offspring. Females with successful breeding history were randomized to three groups, a placebo group and groups treated with the novel formulation at 1× or 3× multiples of the maximum exposure dose. Females were dosed at 28-day intervals, at least twice before mating, then during a period including mating, pregnancy, whelping and 56 days of lactation. In the placebo, 1× and 3× groups, 10, 9 and 10 females, respectively completed the study (nine, seven and nine females achieved pregnancy), and were dosed 7.1 times on average. Breeding parameters included success of mating, success of gestation, length of gestation, abortion rate, number of live, dead and stillborn kittens at birth, number of kittens with abnormalities, weight of kittens after birth and at weaning, growth of kittens, proportion of male and female kittens, and proportion of kittens born alive and weaned. No significant adverse reactions related to the novel combination were observed on females and on kittens; no significant and adverse effects on breeding parameters were observed.
Efficacy of a novel topical combination of esafoxolaner, eprinomectin and praziquantel againstAmblyomma americanumin cats
Authors: Prullage Joe , Baker Christine , Mansour Abdelmoneim , McCall Scott , Young David , Tielemans Eric
Published: April 2021

Esafoxolaner, a purified enantiomer of afoxolaner with insecticidal and acaricidal properties, is combined with eprinomectin and praziquantel in NexGard®Combo, a novel topical endectoparasiticide product for cats. The efficacy of this novel formulation was assessed in two experimental studies against induced infestations withAmblyomma americanum, a tick species of major importance, highly prevalent in a large southeastern quarter of the United States. In each study, 10 cats were randomly allocated to a placebo control group and 10 cats to a novel formulation treated group. Infested cats were treated topically once at the minimum recommended dose. Both studies were designed to test curative efficacy on existing infestation, 72 h after treatment, and to test preventive efficacy, 72 h after subsequent weekly (Study #1) or fortnightly (Study #2) infestations for one month. For each infestation, all cats were infested with 50 unfed adultA. americanum. At each tick count, in both studies, at least 8 in 10 placebo control cats were infested with 13 (26%) or more live ticks, demonstrating adequate infestation throughout the studies. Curative efficacy of the novel formulation was 99% in both studies; preventive efficacy was 92% and 100% for at least one month.
Efficacy of a novel topical combination of esafoxolaner, eprinomectin and praziquantel against ear mite (Otodectes cynotis) infestations in cats
Authors: Tielemans Eric , Prullage Joe , Tomoko Otsuki , Liebenberg Julian , Capári Balázs , Sotiraki Smaragda , Kostopoulou Despoina , Ligda Panagiota , Ulrich Michael , Knaus Martin
Published: April 2021

Esafoxolaner, a purified enantiomer of afoxolaner with insecticidal and acaricidal properties, is combined with eprinomectin and praziquantel, nematodicidal and cestodicidal compounds, in NexGard®Combo, a novel topical endectoparasiticide formulation for cats. The efficacy of this formulation was assessed againstOtodectes cynotisin two laboratory studies conducted in South Africa and in the USA with local isolates, and in one field trial conducted in Europe. In each study, cats were randomly allocated to a placebo-treated control group and a novel formulation-treated group. In the laboratory studies, cats were treated at the minimum recommended dose; in the field trial, cats were treated at label dose. All included cats were diagnosed positive forO. cynotisprior to treatment by otoscopy. The main variable of efficacy was a comparison of the number of liveO. cynotiscollected in both ear canals of all cats in the treated and control groups, one month after treatment. Efficacy of the novel topical formulation exceeded 97% in the three studies. These studies demonstrated the high effectiveness of NexGard®Combo in cats for the treatment ofO. cynotisinfestations. No health abnormalities were attributed to the treatment in any of the studies.
Efficacy of a novel topical combination of esafoxolaner, eprinomectin and praziquantel against Echinococcus multilocularis infections in cats
Authors: Prullage Joe , Bowman Dwight , Ulrich Michael , Tielemans Eric
Published: April 2021

NexGard® Combo, a novel topical endectoparasiticide formulation for cats combining esafoxolaner, eprinomectin and praziquantel, for the treatment of internal and external parasite infestations, including arthropods, nematodes and cestodes, was tested for efficacy against induced infections of Echinococcus multilocularis in cats, in two experimental studies. The two studies were performed in the United States with the same E. multilocularis isolate sourced locally. In each study, 20 cats were inoculated intra-gastrically with ~30,000 E. multilocularis protoscoleces three weeks before treatment, then ten cats were randomly allocated to a placebo control group or to the novel formulation treated group. Inoculated cats were treated topically once at the minimum recommended dose of the novel formulation, or with an identical volume of placebo. One week after treatment, cats were humanely euthanized for parasite recovery and count. The efficacy calculation was based on comparison of number of scoleces found in the control group and the novel formulation group. In the two control groups, E. multilocularis scoleces were found in five (range: 30–1025) and eight (range 2–345) cats, the geometric means inclusive of the ten cats per group were 8.9 and 28.8, respectively. In the two novel formulation-treated groups, none of the cats harbored any E. multilocularis scoleces, demonstrating 100% efficacy.
Efficacy of a novel topical combination of esafoxolaner, eprinomectin and praziquantel for the prevention of heartworm disease in cats
Authors: Baker Christine , McCall John , Mansour Abdelmoneim , McCall Scott , Shaffer Tayna , Wakeland Kenneth , Mitchell Elizabeth , Frost Justin , Tielemans Eric , Bowman Dwight
Published: April 2021

NexGard® Combo is a novel topical endectoparasiticide formulation for cats combining the insecticide/acaricide esafoxolaner, the nematodicide eprinomectin and the cestodicide praziquantel. The efficacy of this novel formulation for the prevention of heartworm disease in cats was tested in two experimental studies using an induced infection model and a randomized, blinded, placebo-controlled study design, and two USA isolates of Dirofilaria immitis. In each study, 20 naïve cats were each inoculated sub-cutaneously with 100 third-stage larvae of D. immitis 30 days before treatment. Following randomization to two treatment groups of ten cats, each cat was treated topically once, either with the minimum recommended dose of the novel formulation, or with an identical volume of placebo. Five months after treatment (6 months after infections), the cats were humanely euthanized for parasite recovery and count. Efficacy was calculated by comparison of the numbers of adult D. immitis recovered in the control and in the novel formulation groups. In the control groups of each study, D. immitis were recovered in seven and nine cats (respective worm counts ranges 1–7 and 1–16, respective geometric means 1.6 and 5.1). In both studies, none of the treated cats harbored any D. immitis at necropsy and the calculated efficacy of the novel formulation was 100%. There were no adverse reactions related to treatment with the novel formulation. The results of these two studies demonstrate that a topical NexGard® Combo application at the minimum label dose is well-tolerated and efficacious in preventing heartworm disease in cats.
Former les professionnels de santé aux « outils pour lecare »
Authors: Bailleul Marc
Published: April 2021

Contexte :Dans le cadre de l’interrogation de plus en plus grande sur l’importance à donner aux humanités dans les formations des professionnels de santé, pourquoi ne pas entrer par une question « pratique », celle des « outils pour lecare » ?But :Poser quelques principes pour l’élaboration d’un cahier des charges pour une formation à ces outils.Méthode :Mettre à l’épreuve les principes en imaginant des modalités de réalisation.Résultats et conclusion : Un exemple de scénario de formation est exposé et des pistes d’actions et de nouvelles interrogations sont discutées.
Germanium defects in nanodiamonds show promise for quantum information applications
Authors: Fore Meredith
Published: April 2021

Germanium-vacancy defects in nanodiamonds have more ideal optical properties than their nitrogen and silicon counterparts as single photon sources.
Smart textiles: A toolkit to fashion the future
Authors: Ruckdashel Rebecca R. , Venkataraman Dhanya , Park Jay Hoon
Published: April 2021

Smart textiles are adaptive materials that use established textile methods to integrate multifunctionalities beyond apparels. Despite recent advancement, a significant gap exists between commercial needs and the academic state of the art. In this perspective, we aim to address the gap by (i) holistically investigating smart textile system operation, (ii) exploring production methods and materials for stimuli-responsive smart textiles, (iii) discussing key emerging application areas for stimuli-responsive textiles, and (iv) identifying markets, production techniques, and strategies for future development. Stimuli-responsive smart textiles rely on materials and processes to interact with the environment and wearer. Smart textile applications, such as assistive soft robotics, smart healing, and thermal comfort regulation, require textiles to meet the needs of form and function. Smart textile commercialization requires the identification of markets ready for adaptive textiles, wherein a smart phone or patch does not address the consumer needs. Interdisciplinary collaborations can focus efforts to the right applications, bridging the gap between academic research and product relevance, bringing smart textiles into the future.
Property of neoclassical GAMs induced by pellet generated plasma perturbations in the gyrokinetic code XGC
Authors: Togo S. , Loarte A. , Hosokawa M. , Pinches S. D. , Hager R. , Ku S. , Chang C. S.
Published: April 2021

A pellet source model has been implemented into the gyrokinetic code XGC and applied to neoclassical geodesic acoustic mode (GAM) study as the first step to investigate potentially rapid kinetic spread of pellet-born particles following their injection into plasma. In this study, GAM oscillations of the radial electric field, as well as of their effect on the radial particle and energy fluxes, are studied and the observed frequencies agree with theoretical expectations. It is verified that (i) GAM oscillations are driven both within the pellet-fuelled region and for locations at a larger radius than this region and not for locations radially inside the pellet-fuelled region, and that, (ii) even though the poloidal spread along the magnetic field lines is fast, the time-averaged radial plasma transport under GAM oscillations is kept to roughly the same level as the neoclassical transport in the absence of plasma turbulence.
Bulk micro-defect detection with low-angle illumination
Authors: Szarvas T. , Molnár G. , Nádudvari Gy. , Tóth Sz. , Almásy O. , Spindler Sz. , Erdei D. , Pothorszky Sz. , Kretschmer R. , Bauer S.
Published: April 2021

The detection of oxygen precipitates, voids, and other defects is critical for semiconductor wafer makers. One of the industry standard techniques for detecting these Bulk Micro-Defects (BMDs) is Semilab’s Light Scattering Tomograph (LST) system. In this measurement, unpatterned wafers are nominally cleaved in half. Illumination is applied to the front surface of the sample, and the light scattered off of the defects is collected via the cleaved surface. This technique had been limited to the measurement of unpatterned wafers, but device makers show significant interest in measuring BMD distributions on patterned wafers using scattering-based techniques. A pattern on the surface of the wafer can cause significant scattering, making the standard LST technique unsuitable for this task. We present a solution for patterned wafer BMD measurements by an addition of a low-angle illumination unit to the standard LST system. This new illumination unit focuses the light into the bulk of the wafer via the cleaved surface, which enables measurement on patterned samples. The new system is called “light scattering tomograph enhanced by low-angle illumination.” Excellent correlation was found between the detected defect densities obtained by the low-angle and the standard LST illumination mode.
Time-resolved x-ray stroboscopic phase tomography using Talbot interferometer for dynamic deformation measurements
Authors: Wu Yanlin , Takano Hidekazu , Momose Atsushi
Published: April 2021

Time-resolved x-ray phase tomography using a Talbot interferometer and white synchrotron radiation can provide a three-dimensional movie for visualizing the structural change of materials consisting of light elements. In this study, time-resolved x-ray stroboscopic phase tomography using a Talbot interferometer is demonstrated for a vibrating object under 24 Hz compression-stretch fatigue loading. Moiré patterns are recorded by synchronizing drivers for a shutter, grating displacement, and sample rotation with an x-ray camera with a 200 µs exposure, and phase tomograms are reconstructed at specific motion phases of the vibration. The measurement lasts for a few minutes and the δ value changes before breaking, which is considered due to plastic deformation of soft materials under external vibration are depicted three-dimensionally.
Engineering in vitro human neural tissue analogs by 3D bioprinting and electrostimulation
Authors: Warren Danielle , Tomaskovic-Crook Eva , Wallace Gordon G. , Crook Jeremy M.
Published: April 2021

There is a fundamental need for clinically relevant, reproducible, and standardized in vitro human neural tissue models, not least of all to study heterogenic and complex human-specific neurological (such as neuropsychiatric) disorders. Construction of three-dimensional (3D) bioprinted neural tissues from native human-derived stem cells (e.g., neural stem cells) and human pluripotent stem cells (e.g., induced pluripotent) in particular is appreciably impacting research and conceivably clinical translation. Given the ability to artificially and favorably regulate a cell's survival and behavior by manipulating its biophysical environment, careful consideration of the printing technique, supporting biomaterial and specific exogenously delivered stimuli, is both required and advantageous. By doing so, there exists an opportunity, more than ever before, to engineer advanced and precise tissue analogs that closely recapitulate the morphological and functional elements of natural tissues (healthy or diseased). Importantly, the application of electrical stimulation as a method of enhancing printed tissue development in vitro, including neuritogenesis, synaptogenesis, and cellular maturation, has the added advantage of modeling both traditional and new stimulation platforms, toward improved understanding of efficacy and innovative electroceutical development and application.
The limiting behavior of the Riemann solutions of non-isentropic modified Chaplygin gas dynamics
Authors: Jiang Weifeng , Li Tong , Wang Zhen , Fang Shutian
Published: April 2021

In this article, we construct the Riemann solutions of the compressible Euler equations in non-isentropic modified Chaplygin gas. In order to compare the Riemann solutions of modified and pure Chaplygin gas, we extend the solvable region of the Riemann solution of the pure Chaplygin gas state and discover the formation of the δ-shock waves. By studying the limiting behavior, we find that the limit of the Riemann solutions of modified Chaplygin gas is the same as pure Chaplygin gas including the δ-shock waves. Finally, we perform some numerical simulations to verify the theoretical analysis.
Microwave-accessibility conditions estimated by plasma parameters obtained experimentally on electron cyclotron resonance ion source
Authors: Kubo Wataru , Harisaki Shuhei , Owada Issei , Sato Koichi , Tsuda Kazuki , Kato Yushi
Published: April 2021

We insert two probes in the upstream and the downstream regions with respect to the electron cyclotron resonance (ECR) zone which is formed at the center of mirror fields. We measure simultaneously plasma parameters in those regions by each of them under the same operating condition. We measure ion saturation currents Iis and electron energy distribution functions at two positions. We obtain measurement results that suggest the more efficient ECR on the side closer to the microwave-launchings than those on the other side. It is consistent with the accessibility condition of the right-hand polarization wave. We also compare the charge state distributions of Ar ion beams extracted in the case of launching microwaves from the coaxial semi-dipole antenna and those from the rod antenna. We observe the higher multicharged ion beam currents at the low microwave powers in the case of the rod antenna than those in the case of the coaxial semi-dipole antenna. We also confirm stable increasements of ion beam currents at considerably high microwave powers in the case of the coaxial semi-dipole antenna. Based on the experimental results, we propose a new microwave-launching method, “dual-ECR heating” and report its preferable preliminary experimental results in this paper.
Numerical study of Langmuir wave coalescence in laser-plasma interaction
Authors: Pérez F. , Amiranoff F. , Briand C. , Depierreux S. , Grech M. , Lancia L. , Loiseau P. , Marquès J.-R. , Riconda C. , Vinci T.
Published: April 2021

Type-III-burst radio signals can be mimicked in the laboratory via laser-plasma interaction. Instead of an electron beam generating Langmuir waves (LWs) in the interplanetary medium, the LWs are created by a laser interacting with a millimeter-sized plasma through the stimulated Raman instability. In both cases, the LWs feed the Langmuir decay instability which scatters them in several directions. The resulting LWs may couple to form electromagnetic emission at twice the plasma frequency, which has been detected in the interplanetary medium, and recently in a laboratory laser experiment [Marquès et al., Phys. Rev. Lett. 124, 135001 (2020)]. This article presents the first numerical analysis of this laser configuration using particle-in-cell simulations, providing details on the wave spectra that are too difficult to measure in experiments. The role of some parameters is addressed, with a focus on laser intensity, in order to illustrate the behavior of the electromagnetic emission's angular distribution and polarization.
Role of microtearing mode in DIII-D and future high-βp core plasmas
Authors: Jian X. , Holland C. , Candy J. , Ding S. , Belli E. , Chan V. , Staebler G. M. , Garofalo A. M. , Mcclenaghan J. , Snyder P.
Published: April 2021

Excellent confinement has been routinely observed in DIII-D (J. L. Luxon, Nucl. Fusion 2002) high βp discharges, which are characterized by a strong large-radius internal transport barrier (ITB) in almost all kinetic channels. Typically, the ion thermal transport is neoclassical with conventional long-wavelength turbulence instabilities suppressed by α stabilization, while the mechanism for the anomalous electron thermal transport remains unclear [Garofalo et al., Nucl. Fusion 55(12), 123025 (2015)]. A new gyrokinetic analysis shows that while the large values of α in the ITB can stabilize all local electrostatic drift wave (ES-DW) instabilities as well as the kinetic ballooning mode, a new slab-like microtearing mode (MTM) with its eigenfunction mainly peaking on the high field slide is destabilized. This destabilization is shown to be more likely to happen in discharges with high safety factors. Nonlinear gyrokinetic simulations demonstrate that this MTM branch can reproduce the experimentally inferred electron thermal flux in the ITB region and, therefore, provide convincing evidence that the electron temperature profile in the ITB is regulated by the MTM. Extrapolations to the future scenarios, like ITER high βp plasmas, show that the dominant instability is likely to come back to ES-DW due to the lower density gradient and collisionality. However, even in this regime, some unusual features associated with MTMs predicted for DIII-D parameters, such as the high-field-side peaking and slab nature, may remain for the reactor ES-DW.
A classification of lowest weight irreducible modules over Z22-graded extension of osp(1|2)
Authors: Amakawa K. , Aizawa N.
Published: April 2021

We investigate representations of the Z22-graded extension of osp(1|2), which is the spectrum generating algebra of the recently introduced Z22-graded version of superconformal mechanics. The main result is a classification of irreducible lowest weight modules of the Z22-graded extension of osp(1|2). This is done via the introduction of Verma modules and its maximal invariant submodule generated by singular vectors. Explicit formulas of all singular vectors are also presented.
Identifying observable carrier-envelope phase effects in laser wakefield acceleration with near-single-cycle pulses
Authors: Huijts Julius , Andriyash Igor A. , Rovige Lucas , Vernier Aline , Faure Jérôme
Published: April 2021

Driving laser wakefield acceleration with extremely short, near single-cycle laser pulses is crucial to the realization of an electron source that can operate at kHz-repetition rate while relying on modest laser energy. It is also interesting from a fundamental point of view, as the ponderomotive approximation is no longer valid for such short pulses. Through particle-in-cell simulations, we show how the plasma response becomes asymmetric in the plane of laser polarization, and dependent on the carrier-envelope phase (CEP) of the laser pulse. For the case of self-injection, this in turn strongly affects the initial conditions of injected electrons, causing collective betatron oscillations of the electron beam. As a result, the electron beam pointing, electron energy spectrum, and the direction of emitted betatron radiation become CEP dependent. For injection in a density gradient, the effect on beam pointing is reduced and the electron energy spectrum is CEP independent, as electron injection is mostly longitudinal and mainly determined by the density gradient. Our results highlight the importance of controlling the CEP in this regime for producing stable and reproducible relativistic electron beams and identify how CEP effects may be observed in experiments. In the future, CEP control may become an additional tool to control the energy spectrum or pointing of the accelerated electron beam.
Flow-induced vibrations of a pair of in-line square cylinders
Authors: Kumar Deepak , Sen Subhankar
Published: April 2021

Flow-induced bidirectional vibrations of two in-line square cylinders of same size and mass ratio (=10) are analyzed at Reynolds number, Re = 100. The cylinders are located in the co-shedding regime, i.e., they are separated by a normalized center-to-center spacing of 5. The reduced speed, U*, is varied from 3 to 15 keeping Re constant. The upstream and downstream cylinders display identical frequency characteristics with U*. Accordingly, the cylinders share identical decomposition of dynamic response. The response is composed of the desynchronization regimes and lower branch; an initial branch does not exist. The vibrations are hysteretic at the lock-in boundaries whereas for a single square oscillator, hysteresis is identified only near the onset of lock-in. Hysteresis in the solutions for U*=7 within the lower branch is reflected in the wake mode of the rear cylinder whereas for the upstream cylinder, wake mode remains identical. The vortex-induced vibration (VIV) of the upstream cylinder is qualitatively similar to that of an isolated square oscillator. Despite the range of lock-in of the cylinders being identical, the VIV of the downstream cylinder departs significantly from its upstream counterpart. The shear layers separated from the front cylinder impinge on the rear cylinder and alter its flow field. The rear cylinder executes high amplitude VIV over the entire lower branch. The symmetry of the drag-lift phase diagrams does not necessarily translate to symmetric phase plots of in-line and cross-stream response. The drag and in-line response of the cylinders are out of phase throughout.
An inertial electrostatic confinement fusion system based on graphite
Authors: Bowden-Reid Richard , Khachan Joe
Published: April 2021

Inertial electrostatic confinement (IEC) devices use concentric electrodes to accelerate ions to sufficient energies to produce nuclear fusion. In a previous publication, we have indicated that, when operating at low power, fusion events largely occur when high energy ions impact neutral molecules that are adsorbed on the cathode surface. The selection of the cathode material therefore plays an important role in determining the absolute fusion output of an IEC machine. A study is presented in which a pair of matching IEC cathodes were constructed from 316 stainless steel and graphite and the fusion characteristics of the grids examined as a function of system pressure and discharge power. Graphite is shown to be an excellent cathode material, producing fusion rates 2.2–4 times that of stainless steel. Due to the excellent deuterium trapping properties of graphite, it is likely this enhancement factor will continue to grow as operating power is further increased.
Impact of trace amounts of interfacial oxidation on the spin–orbit torque in the Co/Pt heterostructures
Authors: Feng Xiaoyu , Yao Jiguang , Cui Yongwei , Zhang Peng , Bai Qiaoning , Xi Li , Cao Jiangwei , Xue Desheng , Fan Xiaolong
Published: April 2021

We found that the exposure of a Co/Pt bilayer to air will result in a trace amount of oxidation at the Co/Pt interface, while the Pt layer is immune to oxidation. The appearance of CoOx results in a negative spin Hall magnetoresistance and unconventional spin–orbit torques (SOTs), which are observed through temperature-dependent transport and spin-torque ferromagnetic resonance measurements. These results can be understood by considering CoOx as an individual magnetic layer between Pt and Co, with two important characteristics: (1) its magnetization is aligned in the plane that is perpendicular to the magnetization of Co and (2) the spin transparency of CoOx increases with increasing temperature. These results help us understand the features of spin transport at the interface when oxidation occurs and further indicate that trace amounts of oxidation can be a highly effective method to control SOT in magnetic heterostructures.
Industrial view of plasmonic devices made by nanoimprint or injection molding
Authors: Prinz Iris , Haslinger Michael J. , Mühlberger Michael , Reiter Gottfried , Prinz Adrian , Schmidt Martina M. , Schaller Thorsten , Bauer Maria , Musso Maurizio , Bauer Georg
Published: April 2021

We present a perspective of the industrial realization of plasmonic devices especially for life science and in vitro diagnostic applications. The main focus is on the manufacturing technologies Nanoimprint Lithography and injection molding as scalable processes for high volume manufacturing. Both technologies have their individual strengths and technical restrictions, which are discussed along different examples for plasmonic applications especially for biosensor applications.
Optical spectra and interfacial band offsets of pulse-laser-deposited metal-oxides: SnO2, TiO2, and ZnO
Authors: Nguyen Nhan V. , Nguyen Nam , Hattrick-Simpers Jason R. , Kirillov Oleg A. , Green Martin L.
Published: April 2021

Transparent conducting oxides are electrically conductive materials with high optical transmittance in the visible region of the spectrum and are useful in a wide range of applications. In this study, the optical spectra of a set of single-phase transparent conducting oxides TiO2, ZnO, and SnO2 grown by pulse laser deposition are measured by vacuum ultraviolet spectroscopic ellipsometry and the optical bandgaps are determined to be 3.30 ± 0.05 eV, 3.13 ± 0.05 eV, and 3.95 ± 0.05 eV, respectively. Differences between these values and previous measurements are discussed. SnO2 and ZnO optical responses at the bandgap reveal that they are a direct bandgap, while TiO2 appears to show an indirect type. For the interfacial electronic characteristics, the internal photoemission measurement shows that the electronic barriers of these naturally n-type-doped metal oxides adjacent to an Al2O3 layer originate from the Fermi level in their conduction bands. The band offset determination shows that the barrier heights are similar and have a small internal field dependence. The work functions are then estimated from the measured barrier heights.
Rotational energy harvesting systems using piezoelectric materials: A review
Authors: Wang Zhe , He Lipeng , Gu Xiangfeng , Yang Shuo , Wang Shicheng , Wang Pingkai , Cheng Guanggming
Published: April 2021

In the past few decades, rotary energy harvesting has received more and more attention and made great progress. The energy harvesting device aims to collect environmental energy around electronic equipment and convert it into usable electrical energy, developing self-powered equipment that does not require replaceable power supplies. This paper provides a holistic review of energy harvesting techniques from rotary motion using piezoelectric materials. It introduces the basic principles of piezoelectric energy harvesting, the vibrational modes of piezoelectric elements, and the materials of piezoelectric elements. There are four types of rotational energy harvesting technologies: inertial excitation, contact execution, magnetic coupling, and hybrid systems. An overview of each technology is made, and then, a detailed analysis is carried out. Different types of rotating energy harvesting technologies are compared, and the advantages and disadvantages of each technology are analyzed. Finally, this paper discusses the future direction and goals of improving energy harvesting technology. This Review will help researchers understand piezoelectric energy harvesting to effectively convert rotational energy into electrical energy.
Investigation of thermal large-eddy simulation approaches in a highly turbulent channel flow submitted to strong asymmetric heating
Authors: David M. , Toutant A. , Bataille F.
Published: April 2021

This study deals with thermal large-eddy simulation (T-LES) of anisothermal turbulent channel flow in the working conditions of solar receivers used in concentrated solar power towers. The flow is characterized by high-temperature levels and strong heat fluxes. The hot and cold friction Reynolds numbers of the simulations are, respectively, 630 and 970. The Navier–Stokes equations are solved under the low-Mach number approximation and the thermal dilatation is taken into account. The momentum convection and the density–velocity correlation subgrid terms are modeled. Functional, structural, and mixed subgrid-scale models are investigated. A tensorial version of the classical anisotropic minimum-dissipation (AMD) model is studied and produces good results. A Quick scheme and a second-order-centered scheme are tested for the discretization of the mass convection term. First, a global assessment of 22 large-eddy simulations is proposed, then six are selected for a careful analysis including profiles of mean quantities and fluctuation values as well as a comparison of instantaneous fields. Probability density functions of wall heat fluxes are plotted. The results point out that T-LESs performed with the Quick scheme tend to underestimate the wall heat flux whereas the second-order-centered scheme significantly improves its estimation. T-LESs tend to overestimate the peaks of velocity correlations. When regarding the dimensionless profiles of fluctuations, the tensorial AMD model provides better results than the other assessed models. For the heat flux estimation, the best agreement is found with the AMD model combined with the second-order-centered scheme.
Interpolating individual line-of-sight neutron spectrometer measurements onto the “sky” at the National Ignition Facility (NIF)
Authors: Hartouni E. P. , Bionta R. M. , Casey D. T. , Eckart M. J. , Gatu-Johnson M. , Grim G. P. , Hahn K. D. , Jeet J. , Kerr S. M. , Kritcher A. L. , MacGowan B. J. , Moore A. S. , Munro D. H. , Schlossberg D. J. , Zylstra A.
Published: April 2021

Nuclear diagnostics provide measurements of inertial confinement fusion implosions used as metrics of performance for the shot. The interpretation of these measurements for shots with low mode asymmetries requires a way of combining the data to produce a “sky map” where the individual line-of-sight values are used to interpolate to other positions in the sky. These interpolations can provide information regarding the orientation of the low mode asymmetries. We describe the interpolation method, associated uncertainties, and correlations between different metrics, e.g., Tion, down scatter ratio, and hot-spot velocity direction. This work is also related to recently reported studies [H. G. Rinderknecht et al., Phys. Rev. Lett. 124, 145002 (2020) and K. M. Woo et al., Phys. Plasmas 27, 062702 (2020)] of low mode asymmetries. We report an analysis that makes use of a newly commissioned line of sight, a scheme for incorporating multiple neutron spectrum measurement types, and recent work on the sources of implosion asymmetry to provide a more complete picture of implosion performance.
Interatomic potential parameterization using particle swarm optimization: Case study of glassy silica
Authors: Christensen Rasmus , Sørensen Søren S. , Liu Han , Li Kevin , Bauchy Mathieu , Smedskjaer Morten M.
Published: April 2021

Classical molecular dynamics simulations of glassy materials rely on the availability of accurate yet computationally efficient interatomic force fields. The parameterization of new potentials remains challenging due to the non-convex nature of the accompanying optimization problem, which renders the traditional optimization methods inefficient or subject to bias. In this study, we present a new parameterization method based on particle swarm optimization (PSO), which is a stochastic population-based optimization method. Using glassy silica as a case study, we introduce two interatomic potentials using PSO, which are parameterized so as to match structural features obtained from ab initio simulations and experimental neutron diffraction data. We find that the PSO algorithm is highly efficient at searching for and identifying viable potential parameters that reproduce the structural features used as the target in the parameterization. The presented approach is very general and can be easily applied to other interatomic potential parameterization schemes.
Evolutionary optimization of light-matter coupling in open plasmonic cavities
Authors: Bai Ping , ter Huurne Stan , van Heijst Erik , Murai Shunsuke , Gómez Rivas Jaime
Published: April 2021

Using a particle swarm optimization algorithm and finite-difference in time-domain simulations, we optimize the coupling strength between excitons in poly(3-hexylthiophene-2,5-diyl) (P3HT) and surface lattice resonances in open cavities defined by arrays of aluminum nanoparticles. Strong light–matter coupling and the formation of exciton-polaritons are demonstrated. Nanoparticle arrays with optimal dimensions have been fabricated and measured, validating the predictions by the numerical method. P3HT is a regioregular semiconducting polymer used as a donor material in acceptor–donor blends for organic photovoltaic applications. Our results demonstrate the efficacy of the proposed method for the optimization of light–matter coupling and its potential application for the enhanced performance of optoelectronic devices.
Dynamic behavior of soft, resonant metamaterials: Experiments and simulations
Authors: Chem Bryan , Jiang Yijie , Liu Chenchen , Raney Jordan R. , Reina Celia
Published: April 2021

Though additive manufacturing and novel optimization techniques have led to many recent advances in elastic metamaterials, difficult fundamental challenges (e.g., narrow bandgaps) and practical challenges (e.g., dissipation and friction) remain. This work introduces simple and hierarchical resonant metamaterials made of soft polydimethylsiloxane rubber and removable steel insets. The additively manufactured samples are able to produce bandgaps with a gap–midgap ratio of 81.8%, which surpasses the majority of resonant, metamaterials of the same class and greatly outperforms analogous resonant structures with a stiff epoxy matrix. The role of several physical features on the transmission loss (TL) curve is assessed in detail numerically and compared to the experimental TL data. Matrix compliance is found to be a rich mechanism for bandgap widening with a dual effect: it deepens the traditional resonant bandgaps, and it can selectively shift certain vibrational modes to lower frequencies and aid in the merging of multiple bandgaps. This can lead to an overall increase of the bandgap width of over an order of magnitude. Viscous dissipation, friction, and the stochastic nature of geometrical inaccuracies common in additive manufacturing were also found to shape the TL curve and associated bandgaps to various degrees. Some of these mechanisms, combined with a soft frame, can further help merge bandgaps in rainbow or hierarchical designs and form ultrabroad, subwavelength bandgaps.