bluuebunny/crossref_metadata_2025 huggingface dataset:
Qualitative Histological Evaluation of Various Decalcifying Agents on Human Dental Tissue
Authors: Bumalee Dusit , Lapthanasupkul Puangwan , Songkampol Khumpee , Srimaneekarn Natchalee , Kitkumthorn Nakarin , Arayapisit Tawepong
Published: October 2022

Objective Dental hard tissue is among the hardest tissue of humans because it contains high amounts of inorganic substances. This leads to difficulty in preparing histological sections for histopathological examination. Acid and chelating agents are generally used to decalcify teeth. We aimed to compare the histological quality of teeth decalcified with various calcifying agents including 5% nitric acid, 50% formic acid with 20% sodium citrate (Anna Morse solution), 10% formic acid, commercial solution, and 14.4% neutral EDTA.

Materials and Methods Freshly extracted premolar teeth were fixed and submitted for decalcification using different agents. Histological examination was qualitatively evaluated for tissue integrity and staining quality.

Results Dentin integrity of teeth decalcified with all decalcifying agents did not show any statistical differences except that with the formic acid, whereas cementum integrity decalcified with neutral EDTA showed a superior score compared with other agents. Tissue integrity and staining quality of dental pulp cells were the best decalcified with neutral EDTA or Anna Morse solution.

Conclusion Our findings demonstrated that EDTA and Anna Morse solution gave a similar efficiency in the preservation of tissue integrity while Anna Morse solution may be recommended as a decalcification agent in routine use due to the more satisfying decalcification time than EDTA.
Management of Complex Fistula-in-ano by Interception of Fistula Track with Application of Ksharasutra (IFTAK): A Novel Technique
Authors: Sahu Manoranjan , Sharma Ashish
Published: October 2022

Objective Despite all the technological advances, successful management of complex fistula-in-ano is still a challenge due to recurrence and incontinence. The present study evaluates the outcomes of a novel technique, Interception of Fistula Track with Application of Ksharasutra (IFTAK) in terms of success rate and degree of incontinence.

Methods In the present prospective study, 300 patients with complex fistula-in-ano were treated by the IFTAK technique, whose surgical steps include: incision at the anterior or posterior midline perianal area, identification and interception of the fistulous track at the level of the external sphincter, rerouting the track (and extensions) at the site of interception, and application of a ksharasutra (medicated seton) in the proximal track (from the site of interception to the internal opening) that is laid open gradually, with the resulting wound healing with minimum scarring. The distal track is allowed to heal spontaneously.

Results There were 227 trans-sphincteric and 73 intersphincteric varieties of fistula with supralevator extension in 23 cases, of which 130 were recurrent fistulas, 29 had horseshoe track, while 25 had blind fistula with no cutaneous opening. The mean duration of the ksharasutra application was 8.11 ± 3.86 weeks with an overall success rate of 93.33% at the 1-year follow-up. A total of 3.67% of the cases reported with a mild impairment of continence on the Wexner incontinence scoring system. Pre- and postoperative anal manometry evaluation showed minimal reduction in median basal and squeeze pressures.

Conclusion The IFTAK technique is a minimally invasive, daycare surgical procedure for the management of complex fistula-in-ano with low recurrence and minimal sphincter damage.
Racial Inequities in Asthma Care
Authors: Okelo Sande O.
Published: October 2022

Racial inequities in asthma care are evolving as a recognized factor in long-standing inequities in asthma outcomes (e.g., hospitalization and mortality). Little research has been conducted regarding the presence or absence of racial inequities among patients seen in asthma specialist settings, this is an important area of future research given that asthma specialist care is recommended for patients experiencing the poor asthma outcomes disproportionately experienced by Black and Hispanic patients. This study provides a systematic review of racial asthma care inequities in asthma epidemiology, clinical assessment, medication prescription, and asthma specialist referral practices.
A stylometric approach to the interdiscursivity of professional practice
Authors: Qian Yubin
Published: October 2022

Interdiscursivity of professional practice has gained increasing attention in nascent literature on professional discourse, yet its measurement is under-investigated. The present article, with a highlight on the writer identities in professional discourse, proposed a stylometric approach to the interdiscursivity of professional practice. The stylometric method successfully demystified three professional identities in the MD&A discourse: Specialists in the public relations practice, auditors in the regulatory practice, and analysts in the financial practice. The method also succeeded in quantifying the interdiscursive relations between the three identities. This is the first study that investigates interdiscursivity from a stylometric perspective, which may advance quantitative research into both text-internal and text-external resources engaged in discourse realization.
Ultralow-frequency broadband characteristics of stepwise radial metamaterials
Authors: Li Lixia , He Weitao , Jia Qi , Tong Zhixue , Liu Haixia , Li Pengguo , Li Ling
Published: October 2022

A new type of stepwise radial metamaterial (SRM) with ultralow-frequency and broadband characteristics is proposed in this study. In contrast to the traditional radial metamaterial (TRM), the proposed structure is periodically arranged in a stepwise shape along the radial direction. The propagation characteristics of Lamb waves in the SRM were investigated using the finite element method. For the numerical analysis, the degeneracy between the bands of the SRM was separated, resulting in the opening of the bandgaps in the ultralow-frequency range. The total bandwidth was 75 times that of the TRM, and the wave attenuation ability was increased by more than 70%. The introduction of a stepwise array in the SRM opened up the local resonance and Bragg scattering bandgaps, and as a result, the SRM exhibited ultralow-frequency broadband characteristics. Furthermore, the influences of the structural parameters of the SRM on the bandgap characteristics were discussed. With the increase in the stepped angle, the coupling relationship between the Lamb wave mode and the local resonance was enhanced, which caused the band structure to shift to a lower frequency. In addition, the hole rotation and shape played important roles in the bandgap tuning. Finally, the experimental sample was processed based on the model, and the vibration propagation characteristics were tested to prove its ultralow-frequency broadband characteristics. The proposed shielding approach could provide a better alternative in the field of ultralow-frequency noise reduction and vibration reduction.
Mechanically tunable elastic modulus of freestanding Ba1−xSrxTiO3 membranes via phase-field simulation
Authors: Zhang Kena , Ren Yao , Cao Ye
Published: October 2022

The freestanding ferroelectric membranes with super-elasticity show promising applications in flexible electronic devices such as transducers, memories, etc. While there have been recent studies on the effect of mechanical bending on the domain structure evolutions and phase transitions in ferroelectric membranes, its influence on Young's modulus of these freestanding membranes is less explored, which is crucial for the design and application of flexible electronics. Here, a phase-field model is developed to simulate the tunability of Young's modulus of freestanding Ba1−xSrxTiO3 membranes under mechanical bending. It is demonstrated that the bended membrane shows a uniform Young's modulus compared with unbended membrane. By increasing the bending angle, Young's modulus tunability is enhanced, which can be attributed to the vortex-like domain structures induced by the mechanical bending. These vortex-like domains with large domain wall energy inhibit the subsequent domain switching under externally applied tensile strain and reduce the eigenstrain variation, which leads to a large Young's modulus. In addition, the formation of vortex domain structure is suppressed with increasing Sr2+ content in Ba1−xSrxTiO3 membranes at the same bending degree, resulting in a decrease in Young's modulus tunability. Our work reveals that the tunability of Young's modulus of freestanding ferroelectric membranes can be achieved by mechanical bending, which provides guidance for designing flexible electronic devices.
Active fast ion charge exchange measurements using a neutral particle analyzer and multiple beam species in C-2W
Authors: Kamio S. , Granstedt E. M. , Clary R. , Player G. , Korepanov S. ,   TAE Team
Published: October 2022

In order to measure the fast ion using neutral particle analyzers (NPAs) in the low neutral density core region of a magnetic confinement fusion device, active change exchange measurements are often performed using a neutral beam (NB) as a charge-exchange (CX) target. One of the complications with this approach is that an NB injected as a CX target can also contribute to the total fast ion source. C-2W has a unique solution to this difficulty in that it is equipped with both eight NB injectors, which can inject beams of different particle species, and an electro-magnetic NPA (EM-NPA), which can measure multiple ion species simultaneously. This enables the active and passive fast ion CX components to be clearly distinguished. The decrease in amplitude of the CX spectra when a hydrogen NB is terminated was clearly observed by the EM-NPA in both hydrogen and deuterium channels. This reduction of observed fast ion flux was mainly caused by the diminished fast ion source, not crosstalk or a general reduction in fast ion confinement. As an example application of this technique on C-2W, fast ion behavior during a periodic density drop is explored. The large difference between the active and passive CX components of the EM-NPA signals clearly demonstrates the usefulness of the active fast ion CX measurement.
Design concept verification for a transcranial acoustic lens with instantaneous adaptability
Authors: Ueta Tsuyoshi
Published: October 2022

A lens constructed by optimally arranging point-like scatterers on a lattice was proposed according to the Fresnel lens concept and showed superior performance focusing an incident plane wave on a focal point and suppressing the sound field except in the vicinity of the focal point. In the present study, we investigated the transcranial focusing performance of the scatterer-array lens which is a kind of Fresnel acoustic lens. The arrangement of the scatterers was optimized by minimizing an objective function so that the sound field vanishes within the skull except at the focal point(s) and becomes higher at the focal point(s) than in the surrounding area. It was confirmed that the lens focused the incident plane wave with sufficient intensity and contrast with the surroundings, even transcranially.
Correlation between thermopower and carrier mobility in the thermoelectric semimetal Ta2PdSe6
Authors: Nakano Akitoshi , Maruoka Urara , Terasaki Ichiro
Published: October 2022

We have investigated the transport properties of single crystals of a thermoelectric semimetal Ta2PdSe6 and its niobium-substituted (Ta1−xNbx)2PdSe6 by means of resistivity, thermopower, and Hall resistivity measurements. The residual resistivity ratio systematically decreases by the Nb-substitution, indicating enhanced impurity scattering. The slope and peak-top value of thermopower also systematically decrease upon increasing x. We have analyzed the set of transport data by using a two-carrier model, then revealed strong correlation between the thermopower and carrier mobility in the titled compound. We propose that controlling carrier mobility is a possible route to achieve a high-performance thermoelectric semimetal.
On-chip optical comb sources
Authors: Hermans Artur , Van Gasse Kasper , Kuyken Bart
Published: October 2022

On-chip integration of optical comb sources is crucial in enabling their widespread use. Integrated photonic devices that can be mass-manufactured in semiconductor processing facilities offer a solution for the realization of miniaturized, robust, low-cost, and energy-efficient comb sources. Here, we review the state of the art in on-chip comb sources, their applications, and anticipated developments.
Hydrogen Balmer line broadening in Ar-N2-SiH4 DC glow discharge
Authors: Jauberteau J. L. , Jauberteau I.
Published: October 2022

Broadened hydrogen Balmer lines are observed in a DC glow discharge sustained in Ar–SiH4–N2 gas mixture. This broadening is due to the Doppler frequency shift. H atoms’ translational energy distribution is calculated in different positions between the two electrodes of the discharge along the interelectrode axis and in different gas mixtures. Three main components are observed at 0.6(±0.5) eV, 12(±3) eV, 62(±6) eV, 1(±1) eV, 28(±6) eV, and 105(±12) eV for Hα and Hβ, respectively. They correspond to hydrogen dissociation by electron impact producing H(n = 3, 4) atoms and dissociative recombination of the ion in the cathode fall or backscattered fast H atoms on the cathode surface. The density ratio nH2/nAr ranges from 44% to 13% or from 10% to 3% when a = nH/nH2 = 0.01 and 0.1, respectively, in function of the gas mixture. So, large hydrogen density could be due to hydrogen desorption from the wall and cathodes and/or to the gas recirculation within the reactor. A new low energy component is observed in the Hα line profile, when silane and nitrogen concentrations decrease and increase, respectively. It could also be due to the H atom desorbing from the reactor wall or NHx species dissociated by an electron impact within the reactor.
A 500 kV, 10 kA, 40 ns coaxial Marx generator pulser for cable fed flash x-ray system
Authors: Patel A. S. , K Senthil , Menon Rakhee , Basak Ankan , Chandra Romesh , Mitra S. , Roy Amitava
Published: October 2022

Flash x-ray (FXR) systems are used for dynamic radiography. Depending on the speed of the object, these systems typically require a very short pulse duration (∼25 ns) for image acquisition without motion blur. The conventional Marx generators with zigzag discharge paths result in higher inductance; hence, they do not meet the requirement of shorter pulse duration (30–40 ns) and low impedance (40–60 Ω) simultaneously. A coaxial Marx generator has been designed and developed, which is capable of generating 500 kV peak voltages and 10 kA peak current within a 40 ns pulse duration. The CST simulation of the coaxial Marx generator has been carried out to validate the design parameters. The FXR electron beam diode is powered by this Marx generator. Experiments were carried out to measure the x-ray parameters like pulse width, source size, x-ray energy spectrum, penetration depth, and cone angle. The maximum measured x-ray dose was 62 mR at 1 m distance from the source window. The x-ray radiograph demonstrates a penetration depth of 32 mm in steel kept at 2.5 m distance from the source for 500 kV diode voltages.
Characterization of hole traps in reverse-biased Schottky-type p-GaN gate HEMTs by current-transient method
Authors: Pan Shijie , Feng Shiwei , Li Xuan , Bai Kun , Lu Xiaozhuang , Li Yanjie , Zhang Yamin , Zhou Lixing , Zhang Meng
Published: October 2022

In this study, the current-transient method has been conducted to investigate the trap states in p-GaN gate high-electron-mobility transistors (HEMTs) under reverse gate stress. An irregular threshold voltage shift under reverse gate bias has been observed through the pulsed transfer measurements with different delay times. It suggests that both the hole insufficiency and hole trapping are generated during the reverse gate pulse bias. With proper selection of the delay time based on the pulsed characterizations, the hole detrapping can be effectively evaluated after the hole recovery is completed. In addition, by subtracting the trapping behavior caused by the measurement condition, the actual detrapping transient under reverse gate filling voltages can be obtained with the current-transient method. Three traps have been observed with the energy levels of 0.484, 0.390, and 0.235 eV. The identification of hole traps may provide a basis on the understanding of threshold voltage instability and further improvement of the reliability of p-GaN gate HEMTs.
Inverse design of thermal metamaterials with holey engineering strategy
Authors: Wang Zhaochen , Zhu Zhan , Liu Tianfeng , Hu Run
Published: October 2022

Manipulating heat with thermal metamaterials has garnered increasing attention for enabling underlying physics and promising applications. However, the frequently adopted strategy to fabricate thermal metamaterials is using layered structures, whose design space is limited and, thus, other strategies demand further exploring. Here, we propose the holey engineering strategy as an alternative to design thermal metamaterials based on genetic algorithm optimization. The design procedures are introduced in detail, and two metadevices including the thermal cloak and thermal concentrator, are designed and verified to demonstrate the feasibility and convenience of this strategy. This work proposes a new design method for thermal metamaterials and paves an efficient way for macroscopic heat flow manipulation.
Forces and charge analysis of a water droplet dragged by an electric field
Authors: Liu Yuehui , Xu Xiongwen , Liu Jinping
Published: October 2022

Droplet removal from solid surfaces is particularly important for heat and mass transfer, corrosion protection, and certain technological requirements in production. In this study, we investigate droplet removal from a solid surface using an electric field. First, a visual platform was established to capture a video of the droplet deforming and jumping motion in an electric field, and a deformed ellipse equation was applied to fit the liquid droplet profiles. Second, the electric charge distribution was obtained, and the electric forces on the droplet surface before and after jumping were calculated. The result indicates that the charge only accumulates on the upper surface of the droplet, mostly at the top point, and the maximum charge of the 7 μl droplet is about 2 × 10−4 μC in this experiment. The forces on the droplet are almost constant and maintain a constant acceleration (greater than 10 m/s2) after leaving the surface. Third, the effects of droplet volume, electric field intensity, and electrode plate distance on droplet jumping were quantitatively studied. The experiments show that the electric field intensity required for droplet jumping is independent of the droplet volume but positive with the distance between the plates, when the distance between plates increases from 10 to 18 mm, the critical jumping electric field intensity increases by 0.1 kV/mm. The droplet acceleration decreases by about 20% with the increase in volume (5–10 μl) but increases with the increase in electric field intensity. The charge increases with the increase in electric field intensity, but the charge–mass ratio decreases by about 30% with the increase in volume (5–10 μl). Finally, the results show that a small volume and plate distance are more favorable to stimulating the droplets jumping under the electric field.
An optimized collision-averaged variable soft sphere parameter set for air, carbon, and corresponding ionized species
Authors: Pfeiffer M.
Published: October 2022

A collision-averaged parameter set for air, carbon, and the corresponding ionized species for the variable soft sphere collision model is suggested which is suitable for the earth's atmosphere or mars atmosphere, for example. The parameter set is generated through collision integral fits and a number of optimization steps so that individual sub-sets can also be used for, e.g., air or without ionized species. In addition, the parameter set can be extended by further species without having to carry out the complete optimization again, which is shown in the example of argon. The limitations of the collision-average model are discussed and in which cases the collision-specific model or other models should be used. The model is compared with collision integrals from various publications.
Alternating-current nonlinear electrokinetics in microfluidic insulator-decorated bipolar electrochemistry
Authors: Tao Ye , Liu Weiyu , Ge Zhenyou , Yao Bobin , Ren Yukun
Published: October 2022

We proposed herein a unique method of insulator-decorated bipolar electrochemistry (IDBE), for realizing large-scale separation of bioparticles in microchannels driven by AC dielectrophoresis (DEP). In IDBE, a pair of planar driving electrodes is placed at the bottom of channel sidewalls, between which an array of the rectangular floating electrode (FE) strips without external Ohmic contact are evenly spaced along transversal direction, and a series of insulating dielectric blocks are periodically deposited above all the inter-electrode gaps and in full contact with the channel bottom surface. By creating local field maximum and minimum at multiple sites, IDBE extends well the actuating range of DEP force field from the immediate vicinity of electrode tips in traditional bipolar electrochemistry to current fluid bulk. Considering DEP force plays the dominant role around 1 MHz, we utilize Lagrange particle tracing algorithm to calculate motion trajectories of incoming samples for testing the feasibility of microchip in continuous separation of live and dead yeast cells. By applying suitable voltage parameters, highly efficient DEP sorting is theoretically achievable under a moderate inlet flow rate, where most of the viable yeasts are trapped by positive-DEP to sharp dielectric edges, while all the incoming nonviable yeasts are repelled by negative-DEP to the top surface of both FE and insulating block to form multiple thin beams co-flowing into the channel outlet. The microfluidic device exploiting insulators on bipolar FE effectively expands the actuating range of nonlinear electrodynamics and provides invaluable guidelines for developing flexible electrokinetic frameworks in modern microfluidic systems.
Phase-locking flows between orthogonally stretching parallel plates
Authors: Wang B. , Ayats R. , Meseguer A. , Marques F.
Published: October 2022

In this paper, we explore the stability and dynamical relevance of a wide variety of steady, time-periodic, quasiperiodic, and chaotic flows arising between orthogonally stretching parallel plates. We first explore the stability of all the steady flow solution families formerly identified by Ayats et al. [“Flows between orthogonally stretching parallel plates,” Phys. Fluids 33, 024103 (2021)], concluding that only the one that originates from the Stokesian approximation is actually stable. When both plates are shrinking at identical or nearly the same deceleration rates, this Stokesian flow exhibits a Hopf bifurcation that leads to stable time-periodic regimes. The resulting time-periodic orbits or flows are tracked for different Reynolds numbers and stretching rates while monitoring their Floquet exponents to identify secondary instabilities. It is found that these time-periodic flows also exhibit Neimark–Sacker bifurcations, generating stable quasiperiodic flows (tori) that may sometimes give rise to chaotic dynamics through a Ruelle–Takens–Newhouse scenario. However, chaotic dynamics is unusually observed, as the quasiperiodic flows generally become phase-locked through a resonance mechanism before a strange attractor may arise, thus restoring the time-periodicity of the flow. In this work, we have identified and tracked four different resonance regions, also known as Arnold tongues or horns. In particular, the 1 : 4 strong resonance region is explored in great detail, where the identified scenarios are in very good agreement with normal form theory.
β-heavy-spectrin stabilizes the constricting contractile ring during cytokinesis
Authors: Silva Ana Marta , Chan Fung-Yi , Norman Michael J. , Sobral Ana Filipa , Zanin Esther , Gassmann Reto , Belmonte Julio Monti , Carvalho Ana Xavier
Published: October 2022

Cytokinesis requires the constriction of an actomyosin-based contractile ring and involves multiple F-actin crosslinkers. We show that partial depletion of the C. elegans cytokinetic formin generates contractile rings with low F-actin levels that constrict but are structurally fragile, and we use this background to investigate the roles of the crosslinkers plastin/PLST-1 and β-heavy-spectrin/SMA-1 during ring constriction. We show that the removal of PLST-1 or SMA-1 has opposite effects on the structural integrity of fragile rings. PLST-1 loss reduces cortical tension that resists ring constriction and makes fragile rings less prone to ruptures and regressions, whereas SMA-1 loss exacerbates structural defects, leading to frequent ruptures and cytokinesis failure. Fragile rings without SMA-1 or containing a shorter SMA-1, repeatedly rupture at the same site, and SMA-1::GFP accumulates at repair sites in fragile rings and in rings cut by laser microsurgery. These results establish that β-heavy-spectrin stabilizes the constricting ring and reveals the importance of β-heavy-spectrin size for network connectivity at low F-actin density.
Chronic TREM2 activation exacerbates Aβ-associated tau seeding and spreading
Authors: Jain Nimansha , Lewis Caroline A. , Ulrich Jason D. , Holtzman David M.
Published: October 2022

Variants in the triggering receptor expressed on myeloid cells 2 (TREM2) gene are associated with increased risk for late-onset AD. Genetic loss of or decreased TREM2 function impairs the microglial response to amyloid-β (Aβ) plaques, resulting in more diffuse Aβ plaques and increased peri-plaque neuritic dystrophy and AD-tau seeding. Thus, microglia and TREM2 are at a critical intersection of Aβ and tau pathologies in AD. Since genetically decreasing TREM2 function increases Aβ-induced tau seeding, we hypothesized that chronically increasing TREM2 signaling would decrease amyloid-induced tau-seeding and spreading. Using a mouse model of amyloidosis in which AD-tau is injected into the brain to induce Aβ-dependent tau seeding/spreading, we found that chronic administration of an activating TREM2 antibody increases peri-plaque microglial activation but surprisingly increases peri-plaque NP-tau pathology and neuritic dystrophy, without altering Aβ plaque burden. Our data suggest that sustained microglial activation through TREM2 that does not result in strong amyloid removal may exacerbate Aβ-induced tau pathology, which may have important clinical implications.
Chiral Majorana fermions in two-dimensional square lattice antiferromagnet with proximity-induced superconductivity
Authors: Luo Ma
Published: October 2022

Combination of proximity-induced superconductivity and ferromagnetic exchange field in a two-dimensional square-lattice antiferromagnet with spin–orbit coupling and nonsymmorphic symmetry can induce a topological superconductor phase with chiral Majorana edge states. The lattice model of the Bogoliubov-de Gennes (BdG) Hamiltonian was applied to study the phase diagram of bulks and chiral Majorana edge states in nanoribbons. By numerically studying the phase diagram, we found that the non-uniformity of either the superconducting pairing parameters or the exchange field at the two sublattices is necessary to induce a topological superconductor phase with chiral Majorana edge states. The BdG Chern number of certain topological superconductor phases is ±1 or ±3, such that the corresponding nanoribbons have one or three pairs of chiral Majorana edge states, respectively.
Retro-reflective target with high accuracy for industrial photogrammetry
Authors: Huang Gaoshuang , Huang Guiping , Zhou Yang , Dou Shihao , Wang Weifeng , Hu Xiaofei
Published: October 2022

Retro-reflective targets (RRTs) are important for obtaining the coordinates of the surface points of objects measured using industrial photogrammetry systems. Targeting the low measurement accuracy caused by the poor roundness of the conventional RRT, a novel RRT was designed in this study by covering a die-cut slice with round holes and high roundness on a glass bead reflective film. The roundness of this novel RRT was on average 0.03 mm higher than that of the conventional RRT. The accuracy of the novel RRT was evaluated in terms of both internal and external coincidence accuracies. The measurement repeatability accuracy of the novel RRT was improved by 25.0% compared with that of the conventional RRT. The thinner the die-cut slice thickness, the higher the repeatability in a certain range. Similarly, the plane fitting, flatness measurement, and standard length measurement accuracies were improved by 30.7%, 34.1%, and 28.1%, respectively.
Setting the stage for materials simulation using acoustic metamaterials digital quantum analogue computing platforms
Authors: Deymier P A , Runge K , Hasan M A , Levine J A , Cutillas P
Published: October 2022

We present a model of an externally driven acoustic metamaterial constituted of a nonlinear parallel array of coupled acoustic waveguides that supports logical phi-bits, classical analogues of quantum bits (qubit). Descriptions of correlated multiple phi-bit systems emphasize the importance of representations of phi-bit and multiple phi-bit vector states within the context of their corresponding Hilbert space. Experimental data are used to demonstrate the realization of the single phi-bit Hadamard gate and the phase shift gate. A three phi-bit system is also used to illustrate the development of multiple phi-bit gates as well as a simple quantum-like algorithm. These demonstrations set the stage for the implementation of a digital quantum analogue computing platform based on acoustic metamaterial that can implement quantum-like gates and may offer promise as an efficient platform for the simulation of materials.
ABPO-TVSCAD: alternating Bregman proximity operators approach based on TVSCAD regularization for bioluminescence tomography
Authors: Chen Yi , Du Mengfei , Li Weitong , Su Linzhi , Yi Huangjian , Zhao Fengjun , Li Kang , Wang Lin , Cao Xin
Published: October 2022

Objective. Bioluminescence tomography (BLT) is a promising non-invasive optical medical imaging technique, which can visualize and quantitatively analyze the distribution of tumor cells in living tissues. However, due to the influence of photon scattering effect and ill-conditioned inverse problem, the reconstruction result is unsatisfactory. The purpose of this study is to improve the reconstruction performance of BLT. Approach. An alternating Bregman proximity operators (ABPO) method based on TVSCAD regularization is proposed for BLT reconstruction. TVSCAD combines the anisotropic total variation (TV) regularization constraints and the non-convex smoothly clipped absolute deviation (SCAD) penalty constraints, to make a trade-off between the sparsity and edge preservation of the source. ABPO approach is used to solve the TVSCAD model (ABPO-TVSCAD for short). In addition, to accelerate the convergence speed of the ABPO, we adapt the strategy of shrinking the permission source region, which further improves the performance of ABPO-TVSCAD. Main results. The results of numerical simulations and in vivo xenograft mouse experiment show that our proposed method achieved superior accuracy in spatial localization and morphological reconstruction of bioluminescent source. Significance. ABPO-TVSCAD is an effective and robust reconstruction method for BLT, and we hope that this method can promote the development of optical molecular tomography.
Cross modality fusion for modality-specific lung tumor segmentation in PET-CT images
Authors: Zhang Xu , Zhang Bin , Deng Shengming , Meng Qingquan , Chen Xinjian , Xiang Dehui
Published: October 2022

Although positron emission tomography-computed tomography (PET-CT) images have been widely used, it is still challenging to accurately segment the lung tumor. The respiration, movement and imaging modality lead to large modality discrepancy of the lung tumors between PET images and CT images. To overcome these difficulties, a novel network is designed to simultaneously obtain the corresponding lung tumors of PET images and CT images. The proposed network can fuse the complementary information and preserve modality-specific features of PET images and CT images. Due to the complementarity between PET images and CT images, the two modality images should be fused for automatic lung tumor segmentation. Therefore, cross modality decoding blocks are designed to extract modality-specific features of PET images and CT images with the constraints of the other modality. The edge consistency loss is also designed to solve the problem of blurred boundaries of PET images and CT images. The proposed method is tested on 126 PET-CT images with non-small cell lung cancer, and Dice similarity coefficient scores of lung tumor segmentation reach 75.66 ± 19.42 in CT images and 79.85 ± 16.76 in PET images, respectively. Extensive comparisons with state-of-the-art lung tumor segmentation methods have also been performed to demonstrate the superiority of the proposed network.
Semi-supervised deep networks for plasma state identification
Authors: Zorek Matěj , Škvára Vít , Šmídl Václav , Pevný Tomáš , Seidl Jakub , Grover Ondřej
Published: October 2022

Correct and timely detection of plasma confinement regimes and edge localized modes (ELMs) is important for improving the operation of tokamaks. Existing machine learning approaches detect these regimes as a form of post-processing of experimental data. Moreover, they are typically trained on a large dataset of tens of labeled discharges, which may be costly to build. We investigate the ability of current machine learning approaches to detect the confinement regime and ELMs with the smallest possible delay after the latest measurement. We also demonstrate that including unlabeled data into the training process can improve the results in a situation where only a limited set of reliable labels is available. All training and validation is performed on data from the COMPASS tokamak. The InceptionTime architecture trained using a semi-supervised approach was found to be the most accurate method based on the set of tested variants. It is able to achieve good overall accuracy of the regime classification at the time instant of 100 µs delayed behind the latest data record. We also evaluate the capability of the model to correctly predict class transitions. While ELM occurrence can be detected with a tolerance smaller than 50 µs, detection of the confinement regime transition is more demanding and it was successful with 2 ms tolerance. Sensitivity studies to different values of model parameters are provided. We believe that the achieved accuracy is acceptable in practice and the method could be used in real-time operation.
Current quench and vessel currents characterisation at the COMPASS tokamak
Authors: Matveeva E , Havlicek J , Artola F J , Yanovskiy V , Havranek A , Adamek J , Gerardin J , Imrisek M , Loarte A , Ficker O , Hronova O , Weinzettl V , Panek R
Published: October 2022

The characterisation of plasma current quench and understanding of its underlying physical processes play a crucial role when designing large fusion devices such as ITER. For the first time, an extensive analysis of the COMPASS tokamak disruption database is presented. A unique set of magnetic diagnostics allows the investigation of local toroidal and poloidal vessel currents, including currents flowing along the open magnetic field lines from the plasma to the vacuum vessel (VV) (i.e., halo currents). Area-normalised current quench times are in agreement with the ITPA 1.67 ms m−2 lower limit. Extremely fast I

p
quench rates of up to 0.6 MA ms−1 are observed during runaway electron campaigns at COMPASS, which are under the ITPA lower limit. Vertical movement of the plasma column is accelerated by the I

p
quench during major disruptions. Toroidal vessel currents of around 2% – 4% of the predisruptive plasma current

I

p

d
i
s
r

are observed during I

p
quench. Net poloidal eddy currents are obtained by Mirnov coils and diamagnetic loop, reaching 3% of

I

p

d
i
s
r

. Using the Mirnov coils it is shown that the halo current magnitude grows and its poloidal profile broadens with increasing plasma current I

p
. Geometric features of the VV structure and in-vessel component positions on the poloidal vessel current measurements are discussed.
The role of the particle aspect ratio in the discharge of a narrow silo
Authors: Pongó Tivadar , Fan Bo , Hernández-Delfin Dariel , Török János , Stannarius Ralf , Hidalgo Raúl Cruz , Börzsönyi Tamás
Published: October 2022

The time evolution of silo discharge is investigated for different granular materials made of spherical or elongated grains in laboratory experiments and with discrete element model (DEM) calculations. For spherical grains, we confirm the widely known typical behavior with constant discharge rate (except for initial and final transients). For elongated particles with aspect ratios between 2 ⩽ L/d ⩽ 6.1, we find a peculiar flow rate increase for larger orifices before the end of the discharge process. While the flow field is practically homogeneous for spherical grains, it has strong gradients for elongated particles with a fast-flowing region in the middle of the silo surrounded by a stagnant zone. For large enough orifice sizes, the flow rate increase is connected with a suppression of the stagnant zone, resulting in an increase in both the packing fraction and flow velocity near the silo outlet within a certain parameter range.
Quantum interference of electrons through electric-field-induced edge states in stacked graphene nanoribbons
Authors: Nguyen Mai-Chung , Nguyen Huy-Viet
Published: October 2022

In this work, we investigate, by means of numerical simulations, the quantum interference of electrons in stacked graphene structures consisting of two unequal width, armchair-edged graphene nanoribbons. Electronic states residing near the edges of the system are induced when an external electric field is applied normal to the ribbons. By reversing the direction of electric field in the central region, one can create an electronic analogue of the optical Fabry-Pérot (FP) interferometer. Electronic junctions formed at the boundaries between the central region and the left and right ones in the former play the role of the partially reflected mirrors in the latter. The observed conductance oscillations demonstrate that electrons in the edge states transporting through the system experience quantum interference similar to that of light waves passing through an optical FP interferometer. Moreover, electronic states formed at the junctions enhance inter-edge scattering which affects electron transmission significantly. The possibility to control electron transport via electric gates is also considered.
Enhancement of structural, linear and non-linear optical properties of Ti1−xCa2xO2 solid solutions
Authors: Ezairi Sara , Elouafi Assaad , Lmai Fatima , Tizliouine Abdesslam
Published: October 2022

Structural and morphological analyses of the Ti1−xCa2xO2 solid solutions and their complete linear and non-linear optical properties were investigated. Ti1−xCa2xO2 (0≤ x ≤0.5) powders were successfully synthesized via solid-state reaction route. The XRD patterns confirmed that the pure and doped samples exhibited anatase TiO2 phase. The crystallite size of TiO2 decreased to 82 nm after Ca doping. Furthermore, the dislocation density and lattice deformation are increased with increasing calcium concentration. SEM analysis revealed that Ti1−xCa2xO2 (0≤ x ≤0.5) powders have a granular structure and with doping, atom aggregations take on softer shapes. Energy dispersive x-ray Analysis (EDX) showed the appropriate composition for the ions depicted in the structure. Using spectrophotometric data, linear and non-linear optical parameters were obtained and associated with the Ca content. The band gap of TiO2 has shifted from 3.11 to 2.8 eV with dopant concentration. As the percentage of Ca increased, the dielectric constant and optical conductivity also increased. The dispersion energy, plasma frequency, non-linear refractive index and Sellmeier’s parameters were also calculated and discussed with respect to Ca doping. The optical results obtained revealed the potential of the Ti1−xCa2xO2 (0≤ x ≤0.5) samples for optical and optoelectronic applications.
Towards 1% accurate galaxy cluster masses: including baryons in weak-lensing mass inference
Authors: Cromer Dylan , Battaglia Nicholas , Miyatake Hironao , Simet Melanie
Published: October 2022

Galaxy clusters are a promising probe of late-time structure growth, but constraints on cosmology from cluster abundances are currently limited by systematics in their inferred masses. One unmitigated systematic effect in weak-lensing mass inference is ignoring the presence of baryons and treating the entire cluster as a dark matter halo. In this work we present a new flexible model for cluster densities that captures both the baryonic and dark matter profiles, a new general technique for calculating the lensing signal of an arbitrary density profile, and a methodology for stacking those lensing signal to appropriately model stacked weak-lensing measurements of galaxy cluster catalogues. We test this model on 1400 simulated clusters. Similarly to previous studies, we find that a dark matter-only model overestimates the average mass by 7.5%, but including our baryonic term reduces that to 0.7%. Since two more variables are marginalized over when we include our baryonic term the posteriors on the cluster mass calibration are larger than the dark matter-only model. Additionally, to mitigate the computational complexity of our model, we construct an emulator (surrogate model) which accurately interpolates our model for parameter inference, while being much faster to use than the raw model. We also provide an open-source software framework for our model and emulator, called maszcal, which will serve as a platform for continued efforts to improve these mass-calibration techniques. In this work, we detail our model, the construction of the emulator, and the tests which we used to validate that our model does mitigate bias. Lastly, we describe tests of the emulator's accuracy.
Upper limits on the dark matter content in globular clusters
Authors: Reynoso-Cordova Javier , Regis Marco , Taoso Marco
Published: October 2022

We present a systematic analysis on the possible presence of dark mass components inside globular clusters (GCs). A spherical Jeans analysis is applied to the stellar kinematics of 10 nearby GCs. On top of the mass distribution provided by the luminous stellar component, we add either dark matter (DM), described by an NFW or Burkert mass profile, or an intermediate mass black-hole (IMBH), described by a point-like mass. Their existence would have important implications in the context of indirect DM searches. After profiling over the stellar parameters, we find no evidence neither for DM nor for IMBH. Upper limits on the two components are reported.
Model-based Performance Characterization of Software Correlators for Radio Interferometer Arrays
Authors: Vázquez A. J. , Elosegui P. , Lonsdale C. J. , Crew G. B. , Fish V. L. , Ruszczyk C. A.
Published: October 2022

Correlation for radio interferometer array applications, including Very Long Baseline Interferometry (VLBI), is a multidisciplinary field that traditionally involves astronomy, geodesy, signal processing, and electronic design. In recent years, however, high-performance computing has been taking over electronic design, complicating this mix with the addition of network engineering, parallel programming, and resource scheduling, among others. High-performance applications go a step further by using specialized hardware like Graphics Processing Units (GPUs) or Field Programmable Gate Arrays (FPGAs), challenging engineers to build and maintain high-performance correlators that efficiently use the available resources. Existing literature has generally benchmarked correlators through narrow comparisons on specific scenarios, and the lack of a formal performance characterization prevents a systematic comparison. This combination of ongoing increasing complexity in software correlation together with the lack of performance models in the literature motivates the development of a performance model that allows us not only to characterize existing correlators and predict their performance in different scenarios but, more importantly, to provide an understanding of the trade-offs inherent to the decisions associated with their design. In this paper, we present a model that achieves both objectives. We validate this model against benchmarking results in the literature, and provide an example for its application for improving cost-effectiveness in the usage of cloud resources.
Rogue Planets and Brown Dwarfs: Predicting the Populations Free-floating Planetary Mass Objects Observable with JWST
Authors: Scholz Aleks , Muzic Koraljka , Jayawardhana Ray , Quinlan Lyra , Wurster James
Published: October 2022

Free-floating (or rogue) planets are planets that are liberated (or ejected) from their host systems. Although simulations predict their existence in substantial numbers, direct observational evidence for free-floating planets with masses below ∼5 M
Jup is still lacking. Several cycle-1 observing programs with JWST aim to hunt for them in four different star-forming clusters. These surveys are designed to be sensitive to masses of 1–15 M
Jup (assuming a hot-start formation), which corresponds to spectral types of early L to late T for the ages of these clusters. If the existing simulations are not wide off the mark, we show here that the planned programs are likely to find up to 10–20 giant rogue planets in moderate density clusters like NGC1333 or IC348, and several dozen to ∼100 in high-density regions like NGC2024 and the Orion Nebula Cluster. These numbers correspond to 1%–5% of the total cluster population; they could be substantially higher if stars form multiple giant planets at birth. In contrast, the number of free-floating brown dwarfs, formed from core collapse (like stars) is expected to be significantly lower, only about 0.25% of the number of stars, or 1–7 for the clusters considered here. Below 10 M
Jup that number drops further by an order of magnitude. We also show that the planned surveys are not at risk of being significantly contaminated by field brown dwarfs in the foreground or background, after spectroscopic confirmation. Taken together, our results imply that if a population of L and T dwarfs were to be found in these JWST surveys, it is expected to be predominantly made up of rogue planets.
Stellar Structure Model in the Post-Newtonian Approximation
Authors: Kremer Gilberto M.
Published: October 2022

In this work the influence of the post-Newtonian corrections to the equations of stellar structure are analyzed. The post-Newtonian Lane–Emden equation follows from the corresponding momentum density balance equation. From a polytropic equation of state the solutions of the Lane–Emden equations in the Newtonian and post-Newtonian theories are determined and the physical quantities for the Sun, the white dwarf Sirius B and neutron stars with masses M ≃ 1.4 M
⊙, 1.8 M
⊙ and 2.0 M
⊙ are calculated. It is shown that the post-Newtonian corrections to the fields of mass density, pressure and temperature are negligible for the Sun and Sirius B, but for stars with strong fields the differences become important. For the neutron stars analyzed here the central pressure and the central temperature which follow from the post-Newtonian Lane–Emden equation are about fifty to sixty percent greater than those of the Newtonian theory and the central mass density is about three to four percent smaller.