bluuebunny/crossref_metadata_2025 huggingface dataset:
Intoxication de chevaux Pur-Sang Arabe d’une même écurie au colchique (Colchicum autumnale) : Cas clinique
Authors: Chedid Maryline E.
Published: August 2023

Le foin contaminé par des plantes toxiques comme le colchique d’automne représente un risque pour la santé des herbivores. Malheureusement une grande variété de plantes toxiques sont présentes en France et en Europe et sont à l’origine de l’intoxication, parfois mortelle, de bon nombre d’animaux. Cet article présente un cas d’intoxication au colchique d’automne et décrit son mécanisme d’action, la réaction des chevaux envers l’administration du foin et finalement les différents symptômes, le traitement et l’évolution de l’état de la jument.
An acoustic-transport splitting method for the barotropic Baer-Nunziato two-phase flow model
Authors: Ait-Ameur Katia , Kokh Samuel , Massot Marc , Pelanti Marica , Pichard Teddy
Published: August 2023

This work focuses on the numerical approximation of the barotropic Baer-Nunziato two-phase flow model. We propose a numerical scheme that relies on an operator splitting method corresponding to a separate treatment of the acoustic and the material transport phenomena. In the subsonic case, this also corresponds to a separate treatment of the fast and the slow propagation phenomena. This approach follows the lines of the implicit-explicit schemes developed in [8]. The operator splitting enable the use of time steps that are no longer constrained by the sound velocity thanks to an implicit treatment of the acoustic waves, while maintaining accuracy in the subsonic regime thanks to an explicit treatment of the material waves. In the present setting, a particular attention will be also given to the discretization of the non-conservative terms that figure in the two-phase model. We prove that the proposed numerical strategy is positivity preserving for the volume fractions and the partial masses. The scheme is tested against several one-dimensional test cases including flows featuring vanishing phases.
Restrained {2}-domination in graphs
Authors: Haghparast Kazhal , Amjadi Jafar , Chellali Mustapha , Sheikholeslami Seyed Mahmoud
Published: August 2023

A restrained {2}-dominating function (R{2}DF) on a graph G = (V, E) is a function f : V → {0, 1, 2} such that : (i) f(N[v]) ≥ 2 for all v ∈ V, where N[v] is the set containing v and all vertices adjacent to v; (ii) the subgraph induced by the vertices assigned 0 under f has no isolated vertices. The weight of an R{2}DF is the sum of its function values over all vertices, and the restrained {2}-domination number γr{2}(G) is the minimum weight of an R{2}DF on G. In this paper, we initiate the study of the restrained {2}-domination number. We first prove that the problem of computing this parameter is NP-complete, even when restricted to bipartite graphs. Then we give various bounds on this parameter. In particular, we establish upper and lower bounds on the restrained {2}-domination number of a tree T in terms of the order, the numbers of leaves and support vertices.
Achtsamkeit mit Kindern – ein unermessliches Potenzial
Authors: Cayla Cécile , Schick Stefa
Published: August 2023

Achtung! Es folgt ein sonderbarer Einstieg ins Thema: Achtsamkeit ist keine Theorie, Achtsamkeit ist eine Praxis. So wird Geschriebenes Ratgeber sein können, doch nur durch Transfer in den Alltag, eine beherzte Anwendung und tägliche Übung ist Achtsamkeit – bei sich selbst angefangen – zu etablieren. Mit Auswirkung auf das Umfeld, hin zu einem zufriedeneren Zusammensein. Vielleicht kann dieser Artikel Einladung sein, täglichen Übungen und Achtsamkeitsritualen Lebensraum zu gewähren.
Underwater versus conventional endoscopic mucosal resection for colorectal lesions: An updated meta-analysis of randomized controlled trials
Authors: Chowdhury Aneesa Rahman , Kim Jin Sun , Xu Mimi , Tom Chloe , Narala Rachan , Kong Niwen , Lee Helen , Vazquez Alejandro , Sahakian Ara , Phan Jennifer , Buxbaum James
Published: August 2023

Background and study aims Colorectal malignancy is a leading cause of death. Conventional endoscopic mucosal resection (CEMR) is a strategy used to resect precancerous lesions that involves injecting fluid beneath a polyp to create a gap for resection. Underwater endoscopic mucosal resection (UEMR) is a newer method that forgoes injection, instead filling the intestinal cavity with water to facilitate polyp resection. Our aim was to compare the safety and efficacy of these approaches by synthesizing the most contemporary evidence.

Methods PubMed, Embase, and Cochrane libraries were searched from inception through November 11, 2022 for randomized controlled trials (RCTs) comparing UEMR and CEMR for resection of colorectal lesions. The primary outcome was the rate of en bloc resection and secondary outcomes included recurrence, procedure time, and adverse events (AEs).

Results A total of 2539 studies were identified through our systematic literature search. After screening, seven RCTs with a total of 1581 polyps were included. UEMR was associated with significantly increased rates of en bloc resection (RR 1.18 [1.03, 1.35]; I2 = 76.6%) versus conventional approaches. No significant differences were found in procedure time, recurrence, or AEs.

Conclusions UEMR is a promising effective technique for removal of colorectal lesions. The most contemporary literature indicates that it improves en bloc resection rate without increasing procedure time, recurrence, or AEs (PROSPERO ID CRD42022374935).
Examining Unilateral and Bilateral Exercises through the
Load-velocity Relationship
Authors: Martínez-Rubio Carlos , Baena-Raya Andrés , Díez-Fernández David M. , Rodríguez-Pérez Manuel Antonio , Pareja-Blanco Fernando
Published: August 2023

This study aimed to examine the load-velocity (L-V) relationship in the
bench-press (BP) and leg-press (LP) exercises performed unilaterally, and
compared this unilateral L-V relationship with the bilateral variants. Nineteen
men (age=23.5±2.1 years) completed two incremental tests in BP
and LP, performed bilaterally and unilaterally, across two sessions with a
48-hour rest period. We found a close relationship between medium propulsive
velocity (MPV) and %1RM in unilateral BP
(R2  =0.97,
SEE=0.06 m·s-1) and LP
(R2=0.96, SEE=0.06 m·s-1).
No significant differences were observed between the preferred and non-preferred
sides in the L-V relationship for either exercise. Additionally, higher
velocities were achieved in unilateral exercises compared to bilateral
exercises, particularly with light and moderate loads
(30–70%1RM) in BP (p<0.05) and with light loads
(30–45%1RM) in LP (p<0.05). Close L-V relationships were
observed in unilateral exercises, without differences in the L-V relationships
between preferred and non-preferred sides despite the interlimb asymmetries in
the absolute strength values. Interestingly, lower velocities were observed at
light loads (~30–45% 1RM) for bilateral compared to
unilateral exercises, which could be explained by different strength deficits
for these exercises.
Homoeopathic Treatment of Mild Cases of COVID-19 on Home Isolation: A Retrospective Observational Study
Authors: Balakrishnan Thankaraj , Thomas Rekha , Mathew George , Rajesh Anu , Jain Saurabh Kumar , Agarwal Radhika , Kapoor Anu
Published: August 2023

While the world grappled with the pandemic of coronavirus disease 2019 (COVID-19), medical fraternity and policy makers tried desperately to control its spread in the absence of any definite treatment protocol. The scope of homoeopathy, which has been historically found effective in epidemics, has been investigated in the present study. This study was conducted to evaluate the effect of individualised homoeopathic medicine on mild cases of COVID-19 under home isolation. A retrospective, single-arm, non-randomised, open-label, observational trial was conducted on 185 laboratory confirmed mild cases of COVID-19 at Nehru Homoeopathic Medical College and Hospital, Delhi, during September to December 2020. Complete symptom resolution days was the primary outcome (from baseline to total zero symptom score); while assessment of severity of each symptom and sign on a scale of 0-3 ( 0- absent, 1-mild. 3- severe), at baseline and Day 14 comprised of the secondary outcome. Intention-to-treat sample (n = 185) was analysed with SPSS IBM version 20. Of all the patients (n = 185), 165 (90%) successfully completed the follow-up period. The mean (interquartile range [IQR]) age was 35 (26–45) years; the male: female ratio was 11:9.2. Fever (56%), cough (54%), fatigue (45%) and sore throat (36%) were the most common symptoms reported. Median (IQR) time for resolution of symptoms was 4 (3–8) days. Sixty-eight per cent patients recovered within 6 days and rest within 7 to 14 days. The most prescribed medicines were Bryonia alba (30%), Arsenicum album (25%) and Pulsatilla nigricans (12%) accounting for 67% of the total medicines. This study, though preliminary, revealed a positive treatment effect of individualised homoeopathic medicines in promptly alleviating the symptoms of mild COVID-19. Randomised controlled trials with greater scientific rigour are warranted.
The Positive Effect of an Online Appointment Portal on a Breast Cancer Screening Program
Authors: Chiereghin Angela , Pizzi Lorenzo , Squillace Lorena , Bazzani Carmen , Roti Lorenzo , Mezzetti Francesca
Published: August 2023

Background The adoption of web-based appointment methods by health care systems is increasing.

Objectives This study primarily aimed to evaluate in the setting of an organized breast cancer screening program the actual usage of an online appointment portal by the target population, i.e., how the online tool was used (type and timing of the actions performed) and by whom (users' characteristics); the effect of coronavirus disease 2019 (COVID-19) on its usage was also investigated. The effect of adopting this tool on the attendance to breast cancer screening was contextually investigated.

Methods Electronic data records of 75,903 women (45–74 years old, residing in the territory of Bologna Local Health Authority) were retrospectively reviewed.

Results In total, 12.4% of women logged into the online portal at least once. Most of them (79.9%) rescheduled, 15.7% viewed, and 4.4% cancelled their own appointment. In addition, 40.6% of all rescheduling actions were performed by the online portal; the remaining was performed by the toll-free number/dedicated email address. The highest peak (13.8%) of web accesses was registered at 10 a.m. Monday to Friday, when the toll-free number service is available. Percentages of portal usage were higher: (1) among the younger women, of Italian nationality, and for the first time invited to mammographic screening (p < 0.0001), and (2) in the pandemic period versus the prepandemic period (12.5 vs. 8.6%, respectively; p < 0.001). Finally, when compared to not using, the online portal usage led to an overall reduction in the no-show rate of almost 20% (p < 0.0001).

Conclusion The action mainly performed by using the online appointment portal was the appointment rescheduling. The usage of this tool had a positive effect on the no-show rate and it can be speculated that has led to a reduction of the request load to be handled by the center's screening staff. Finally, this study confirmed that the COVID-19 pandemic boosted the use of digital technologies.
Modeling the energetic tail of a dusty plasma's electron energy distribution and its effect on dust grain charge and behavior
Authors: Nicolov André , Bellan Paul M.
Published: August 2023

A model for a weakly ionized dusty plasma is proposed in which UV or x-ray radiation continuously creates free electrons at high energy, which then cool through collisions with a cold neutral gas before recombining. The transition of a free electron from high energy at birth to low energy at demise implies that the electron energy distribution is not the simple Maxwellian of an isolated system in thermal equilibrium, but instead has a high-energy tail that depends on the recombination time. This tail can have a major effect on dust grain charging because the flux of tail electrons can be substantial even if the density of tail electrons is small. Detailed analytic and numerical calculations of dust grain charging show that situations exist in which a small high-energy tail dominates charge behavior. This implies that dust grain charge in terrestrial and space dusty plasmas may be significantly underestimated if a Maxwellian distribution is assumed and the non-thermal dynamics are neglected.
Optimizing the thermoelectric transport properties of fast ionic conductor
β
-Ag2S under high pressure and high temperature
Authors: Zhao Wei , Cheng Jiaen , Li Yan , Ye Meiyan , Wang Dianzhen , Wang Lu , Gai Xinmiao , You Cun , Qu Xin , Tao Qiang , Zhu Pinwen
Published: August 2023

Inorganic fast ionic thermoelectric (TE) materials (IFITEMs) exhibit excellent TE capabilities due to the special carrier of delocalized ions. Optimization of the TE performance of an IFITEM, however, is limited by a conflict between its electrical conductivity (σ) and its Seebeck coefficient (S). It remains challenging to regulate σ and S in IFITEMs because they are mainly only stable under high temperature. In this work, σ and S of α-Ag2S (semiconductor) and β-Ag2S (fast ionic conductor) are modulated by the in situ measurement under high pressure and high temperature. It uncovered that pressure increases the electrical conductivity with improving the carrier concentration in α-Ag2S, but increased pressure hinders ion transfer and thus reduces conductivity in β-Ag2S. These results show that the pressure responses of σ and S in α-Ag2S and β-Ag2S are distinctly opposite. Nevertheless, pressure can optimize the power factor (PF) and estimated thermoelectric figure of merit (ZT) in both α-Ag2S and β-Ag2S, with optimum values of 1.97 × 10−4 W/m K2 and 0.122 (3.3 GPa, 447 K), and 2.93 × 10−4 W/m K2 and 0.18 (2.2 GPa, 574 K), respectively. The pressure effect has improved about 4.5 and 3.6 times in PF and ZT of β-Ag2S comparing with α-Ag2S at 0.8 GPa 436 K. This work provides a way to optimize TE performance in fast ionic conductors by altering the pressure, which will help in the production of high-powered TE materials.
Topology optimization of a thermal cloak in the frequency domain
Authors: Vial Benjamin , Guenneau Sébastien , Hao Yang
Published: August 2023

Designing wideband thermal cloaks remains a challenge, especially at high frequencies. We propose an optimization approach for the design of a thermal cloak for an arbitrary object with large thermal conductivity (copper), in a given frequency band and for a specific diffusion direction. Cloaking performance is assessed as a function of frequency (in the optimal direction) and as a function of angle (at the optimal frequency). Near-perfect cloaking is achieved over a finite frequency band, and, moreover, the thermal cloak performs well in the time domain, including in the transient regime, irrespective of the initial temperature distribution. Interestingly, this specially optimized cloak also works fairly well for other objects with large thermal conductivity but breaks down for those of low thermal conductivity.
Laboratory evaluation of a controllable self-degradable temporary plugging agent in fractured reservoir
Authors: Yang Hongbin , Lv Zhiqi , Li Zhe , Guo Bumin , Zhao Jian , Xu Yantao , Xu Wenjiang , Kang Wanli
Published: August 2023

In order to solve the uncontrollable swelling ratio and degradation time and insufficient strength of conventional self-degradable temporary plugging agent (CSD-TPA), a controllable self-degradable temporary plugging agent (SD-TPA) was proposed. A series of SD-TPA were prepared with free radical polymerization, and the SD-TPA was synthesized by different mass ratios of acrylamide, acrylic acid, hydrophobic monomer, and modified nanoparticles. The effects of modified nanoparticles content, hydrophobic monomers content, temperature, and salinity on its swelling performance, self-degradable performance, and rheological properties were researched systematically. The plugging and unblocking performance of SD-TPA were studied by a core displacement test. The experimental results showed that SD-TPA can be gelatinization after 4 h at 40 °C. Under the formation condition, SD-TPA had better viscoelasticity, shear resistance, and higher yield stress than CSD-TPA. The core plugging rate increased from 86.44% to 91.41%, and the formation damage rate decreased to 14.11%. This work provides a new temporary plugging material during hydraulic fracturing process and the swelling ratio, degradation time, and insufficient strength of SD-TPA can be adjusted according to the requirement of fracturing.
Metal–dielectric optical microcavity with tunable Q factor
Authors: Romanenko G. A. , Pankin P. S. , Buzin D. S. , Maksimov D. N. , Sutormin V. S. , Krasnov A. I. , Zelenov F. V. , Masyugin A. N. , Nedelin S. V. , Zolotovskiy N. A. , Tambasov I. A. , Volochaev M. N. , Chen K.-P. , Timofeev I. V.
Published: August 2023

We consider a layered metal–dielectric microcavity with a liquid crystal used as a resonator layer. The transformation of the microcavity spectra is shown experimentally using three methods, namely, mechanical rotation of the sample, heating, and applying external voltage. The obtained spectra exhibit multiple vanishing resonant lines. It is found the vanishing resonant lines are not a spectral manifestation of the bound state in the continuum for this system. Despite the absence of true bound states in the continuum, an experimental tuning of the resonance Q factor via changing the radiation loss rate is demonstrated through variation of the optical properties of the liquid crystal layer.
Image enhancement using an improved adaptive contrast enhancement algorithm in neutron radiography
Authors: Yu Wangtao , Xu Peng , Bao Jie , Zhou Man
Published: August 2023

As a non-destructive testing technique, neutron radiography has received increasing attention in scientific research. However, the inherent limitations of neutron images, such as insufficient resolution and contrast, have been attributed to the low conversion efficiency of the neutron conversion screen and the low-light quantum efficiency of the charge-coupled device camera. This paper presents a novel neutron image enhancement method that utilizes the sparrow search algorithm to automatically optimize the gain factor coefficient of the adaptive contrast enhancement algorithm and incorporates neutron image information to achieve image enhancement. Experimental results show that compared with other enhancement methods, the proposed method can effectively improve the quality of neutron images visually and numerically and has good operational stability.
On the dynamics of nonlinear barotropic–baroclinic interactions through a coupled Gardner hierarchies approach
Authors: Wang Jie , Zhang Ruigang , Yang Liangui , Liu Quansheng
Published: August 2023

The aim of this paper is on the propagations of barotropic–baroclinic coherent structures based on the two-layer quasi-geostrophic model (2LQG) through a Fourier spectrum compliant approach. First, by introducing the barotropic and baroclinic stream functions starting from the 2LQG model, a new coupled Gardner-type evolution equations, representing the interaction processes between the barotropic flow and baroclinic one, are obtained by combining the multi-scale method and the perturbation expansion method. Second, based on the obtained coupled model equations, the physical mechanisms of the nonlinear barotropic–baroclinic interaction are analyzed qualitatively. Within the range of parameters chosen in this paper, quantitative results show that the basic flow, the β effect, and the bottom topography are necessary factors to excite the nonlinear Rossby isolated waves. The results also declare that the dipole-like blockings are readily excited in the flow field and move slowly eastward in both barotropic and baroclinic flow fields.
Pyrovskite: A software package for the high-throughput construction, analysis, and featurization of two- and three-dimensional perovskite systems
Authors: Stanton Robert , Trivedi Dhara J.
Published: August 2023

The increased computational and experimental interest in perovskite systems comprising novel phases and reduced dimensionality has greatly expanded the search space for this class of materials. In similar fields, unified frameworks exist for the procedural generation and subsequent analysis of these complex condensed matter systems. Given the relatively recent rise in popularity of these novel perovskite phases, such a framework is yet to be created. In this work, we introduce Pyrovskite, an open source software package, to aid in both the high-throughput and fine-grained generation, simulation, and subsequent analysis of this expanded family of perovskite systems. Additionally, we introduce a new descriptor for octahedral distortions in systems, including, but not limited to, perovskites. This descriptor quantifies diagonal displacements of the B-site cation in a BX6 octahedral coordination environment, which has been shown to contribute to increased Rashba–Dresselhaus splitting in perovskite systems.
Solvent-pumped evaporation concentration on paper in linear and radial geometries
Authors: Syms Richard R. A. , Wright Steven
Published: August 2023

Solvent-pumped evaporation-driven concentration of an initial distribution of solutes on a porous substrate is considered in one and two dimensions. Approximate analytic solutions to the isotropic advection–dispersion equations are first found for a Gaussian kernel and an infinite domain, following the smoothed particle approximation. Analytic solutions for more general initial distributions are then found as sums of Gaussians, and comparison is made with numerical solutions. In each case, initial distributions are advected toward the stagnation point and concentrated. Two-dimensional analysis is then extended to describe anisotropy in permeability and diffusion, and hydrodynamic dispersion. Radial-flow experiments are performed using filter papers and water-soluble dyes. Diffusion coefficients, temperature and humidity profiles, and the evolution of spot distributions are measured. The results confirm minor anisotropy in permeability and diffusion, limited hydrodynamic dispersion, and largely uniform evaporation. Péclet numbers over 2500 are demonstrated. Evaporation-driven concentration provides a mechanism for solute transport over long timescales. Potential applications lie in the design of paper spray microanalytical devices operating by solvent pumping rather than capillary flow.
Yield stress fluid flows in superhydrophobic channels: From creeping to inertial regime
Authors: Rahmani H. , Kumar H. , Greener J. , Taghavi S. M.
Published: August 2023

In this work, inertial flows of a yield stress fluid in a channel equipped with a superhydrophobic groovy wall are studied through numerical computations. Assuming an ideal Cassie state, the superhydrophobic wall is modeled via arrays of slip, quantified using the Navier slip law, and arrays of stick, corresponding to the no-slip boundary condition. The viscoplastic rheology is modeled using the Bingham constitutive model, implemented via the Papanastasiou regularization technique. The focus is on inertial flows in the thin channel limit, where the groove period is much larger than the half-channel height. The effects of the flow parameters are quantified on the flow variables of interest, including the slip and axial velocity profiles, unyielded plug zones, regime classifications, flow asymmetry indices, effective slip lengths, and friction factors. In particular, an increase in the flow inertia quantified via the Reynolds number affects the flow in several ways, such as reducing the dimensionless slip velocity and effective slip length, increasing the friction factor, inducing an asymmetry in the velocity profile, and showing a non-monotonic effect on the yielding of the center plug. The present work addresses the complex interplay between the yield stress fluid rheology, the wall superhydrophobicity, and the flow inertia, and it can find applications in macro-/micro-transports of non-Newtonian fluids, from oil and gas to health-related industries.
An improved dissipative particle dynamics method for the liquid-particle two-phase flow in microchannels
Authors: Dong Hua , Wu Xu , Fan Liang-Liang , Zhao Liang
Published: August 2023

Liquid-particle two-phase flow in microchannel widely exists in the fields of biomedical and environmental monitoring, such as the lab-chip device for disease diagnosis. The standard dissipative particle dynamics (DPD) method has been previously employed to study the liquid-particle two-phase flow in microchannel, but it cannot accurately simulate the real process because of the unsuitable DPD parameters. In the present study, an improved DPD method was developed by changing the system energy and fitting the characteristic curve between the random force coefficient and the Schmidt number. In addition, a new logarithmic relationship between the conservative force coefficient and the particle size was found. The result demonstrated that the improved DPD method enabled more accurate simulation on the liquid-particle two-phase flow in microchannels than the standard DPD method. For instance, in the simulation of particle sedimentation, the relative deviation between the value obtained by the improved DPD method and the theoretical value was less than 6% while the relative deviation was more than 20% for the standard DPD method. The simulated result of the particle migration in microchannel was in good agreement with the result obtained by Matas et al, and the relative deviation was less than 1.5%. Therefore, the improved DPD method would have great potentials in the study on the liquid-particle two-phase flow in microchannels.
Mass transfer characteristics at cathode/electrolyte interface during electrodeposition of nickel microcolumns with various aspect ratios
Authors: Dong Yanzhuo , Jiang Bingyan , Drummer Dietmar , Zhang Lu
Published: August 2023

The filling behavior of electrodeposited microcolumns is strongly influenced by the mass transfer characteristics at the cathode/electrolyte interface. This study aims to elucidate the influence of the mass transfer characteristics (ion supplementation via diffusion and ion consumption via deposition) on the electrodeposition of microcolumns, thus providing feasible solutions for improving void defects with different feature sizes. The results indicate that ion consumption plays an important role in the mass transfer within large-width microcavities (100 μm). For large-width microcolumns, longer electroforming times lead to higher ion consumption, resulting in nonuniform ion concentration distribution, and consequently uneven deposition rates along the microcavity wall. In microcavities with high aspect ratio (5:1), ion supplementation plays a major role. The low ion supplementation rate does not support a uniform deposition, resulting in a large void defect and a low filling ratio in the deposited microcolumns. Therefore, reducing the ion consumption rate by decreasing the current density from 1 A dm−2 to 0.25 A dm−2 can effectively increase the filling ratio in large-width microcolumns with no significant effect on high aspect ratio microcolumns. On the contrary, the pulse reverse current (forward pulse current density 1 A dm−2, reverse pulse current density 2 A dm−2, frequency 1 Hz, forward pulse duty cycle 0.9) can increase the filling ratio in the high aspect ratio microcolumns by accelerating ion supplementation through dissolution of the deposited layer. By further increasing the reverse pulse current density from 2 A dm−2 to 6 A dm−2, void defects can be completely eliminated and even void-free deposition of high aspect ratio microcolumns (5:1) can be achieved.
Flexible pressure/temperature sensors with heterogeneous integration of ultra-thin silicon and polymer
Authors: Feng Weiwen , Li Peng , Zhang Haozhi , Sun Ke , Li Wei , Li Xinxin
Published: August 2023

Flexible pressure sensors and temperature sensors are widely used in various fields because of their advantages in high flexibility, good shape retention and extremely small thickness. However, it is quite challenging to fabricate ultra-thin flexible pressure sensors with reliable sensing performance. In this work, we propose a new type of silicon–polymer heterogeneously integrated MEMS flexible sensor with an ultra-thin silicon-based absolute pressure sensing element and a thermistor. In the study, a flexible MEMS fabrication process is developed, which enables simultaneous fabrication in two different substrates and self-release of the thin and slim flexible sensor. The front-end section of the flexible sensor is with the width as 125 μm, length as 3.2 cm and total thickness as 12 μm, where the integrated silicon substrate thickness is only 3 μm. The sensor takes a slender shape to allow for medical invasive measurement by inserting it into a slim medical catheter or a syringe needle-tube. The sensitivity of the fabricated ultra-thin absolute pressure sensor is tested as 45.2 μV kPa−1 under 3.3 V supplied voltage, with the nonlinearity as only ±0.16% FS. The sensitivity of the thermistor is 10.4 Ω °C−1 in the range of 0 °C–100 °C. Moreover, the polysilicon thermistor can also serve as a micro-heater, where an electric heating power of 107 μW results in a temperature increase of 13.5 °C. With ultra-thin slim structure and satisfactory performance, the MEMS flexible sensor is promising in various fields like biomedical applications.
Observations and identifications of extreme ultraviolet spectra of Ca-like to Na-like neodymium ions using an electron beam ion trap
Authors: Yang Y , Dipti  , Suzuki C , Gall A , Silwal R , Sanders S , Naing A , Tan J N , Takacs E , Ralchenko Yu
Published: August 2023

Extreme ultraviolet spectra from M-shell transitions in highly-charged Ca-like Nd40+ through Na-like Nd49+ ions were measured at the electron beam ion trap (EBIT) facility of the National Institute of Standards and Technology. To produce the ionization stages of interest, the electron beam energies were varied between 3.60 keV and 10.01 keV. A flat-field grazing incidence spectrometer was used to observe the spectra in the wavelength range between 2.67 nm and 17.30 nm. Simulated spectra generated with detailed collisional-radiative modeling of the non-Maxwellian EBIT plasma were used for line identifications. Forty-seven new spectral lines corresponding to electric-dipole and magnetic-dipole transitions were identified. Measurements were compared to the available previously calculated and predicted values.
Exploration of the crystal structures and electronic features of Y2O3:Er and Y2O3:Er,Yb crystals: a first-principles study
Authors: Ju Meng , Zhang Xiexuan , Hu Shihao , Wang Peng , Xiao Yang , Sun Weiguo , Zhang Chuanzhao , Jin Yuanyuan
Published: August 2023

The Er3+ doped Y2O3 (Y2O3:Er) and Er3+, Yb3+ co-doped Y2O3 (Y2O3:Er,Yb) have attracted considerable attention due to their outstanding optical properties. However, the crystal structures underlying their electronic features are still unclear. In this paper, we carried out the systematical structural evolutions of Y2O3:Er and Y2O3:Er,Yb via the Crystal Structural AnaLYsis by Particle Swarm Optimization structure search method. Two novel monoclinic structures with P2 space group were uncovered for Y2O3:Er and Y2O3:Er,Yb. Validities of the two ground state structures were verified by the good agreements between the calculated x-ray diffraction patterns and the experimental ones. Phonon dispersion curves were also investigated, and the data showed that the ground state structures of both Y2O3:Er and Y2O3:Er,Yb were dynamically stable. Moreover, the density of states, the band structure and the electronic local function of these two systems were also studied. The impurity Er3+ and Yb3+ ions lead to the transition of electronic feature from the insulator to the semiconductor. The Y–O, Er–O, Yb–O bonds are proved to be covalent bonds. These research results can fill up the vacancy and give instructions in the rare-earth doped laser materials in the future.
Evolution of magnetic surfboards and spin glass behavior in (Fe1−p
Ga
p
)2TiO5
Authors: Li Y , Phelan D , Ye F , Zheng H , Krivyakina E , Samarakoon A , LaBarre P G , Neu J , Siegrist T , Rosenkranz S , Syzranov S V , Ramirez A P
Published: August 2023

The unusual anisotropy of the spin glass (SG) transition in the pseudobrookite system Fe2TiO5 has been interpreted as arising from an induced, van der Waals-like, interaction among magnetic clusters. Here we present susceptibility (

χ

) and specific heat data (

C

) for Fe2TiO5 diluted with non-magnetic Ga, (Fe1−p
Ga
p
)2TiO5, for disorder parameter

p

= 0, 0.11, and 0.42, and elastic neutron scattering data for

p

= 0.20. A uniform suppression of

T
g

is observed upon increasing

p

, along with a value of

χ

T
g

that increases as

T
g

decreases, i.e.

d
χ
(

T
g

)

/

d

T
g

<
0

We also observe

C

T

∝

T
2

in the low temperature limit. The observed behavior places (Fe1−p
Ga
p
)2TiO5 in the category of a strongly geometrically frustrated SG.
Unconventional electronic phase transition in SnBi2Te4: role of anomalous thermal expansion
Authors: Dalui Tamal K , Das Bishal , Barman Chanchal K , Ghose Pradeepta K , Sarma Abhisakh , Mahatha Sanjoy K , Diekmann Florian , Rossnagel Kai , Majumdar Subham , Alam Aftab , Giri Saurav
Published: August 2023

We propose SnBi2Te4 to be a novel topological quantum material exhibiting temperature (T) mediated transitions between rich electronic phases. Our combined theoretical and experimental results suggest that SnBi2Te4 goes from a low-T semimetallic phase to a high-T (room temperature) insulating phase via an intermediate metallic phase. Single crystals of SnBi2Te4 are characterized by various experimental probes including synchrotron based x-ray diffraction, magnetoresistance, Hall effect, Seebeck coefficient and magnetization. X-ray diffraction data confirms an anomalous thermal expansion of the unit cell volume below ∼100 K, which significantly affects the bulk band structure and hence the transport properties. Simulated surface states are found to be topologically robust with varying T. This indirectly supports the experimentally observed paramagnetic singularity in the entire T-range. The proposed coexistence of such rich phases is a rare occurrence, yet it facilitates a fertile ground to tune them in a material driven by structural changes.
The critical effect of electron acceleration under enhanced electric field near cathode on the formation of runaway electrons and diffuse discharge in atmosphere
Authors: Ren Chenhua , Huang Bangdou , Zhang Cheng , Qi Bo , Chen Weijiang , Shao Tao
Published: August 2023

Runaway electrons (RAEs) are believed to affect the dynamics of ultra-fast gas breakdown significantly. In this work, considering the field enhancement effect near the micro-protrusion on the cathode surface, the formation of RAEs and diffuse discharge in atmospheric pressure air is investigated by two-dimensional particle-in-cell/Monte Carlo collision simulation. It is found that the beam amplitude of RAEs is dictated by the field enhancement factor and the initial energy of electrons obtained near the micro-protrusion is decisive for their converting to RAEs, which precede the low energy electrons and guide the discharge propagation by improving pre-ionization. As a result, the discharge transfers from the filamentary mode without RAEs to the diffuse mode under the high pre-ionization degree due to RAEs and a wide streamer with a diameter comparable with the gap distance is formed, which transfers from spherical to conical shape. The results of this study illustrate the fundamental process of RAE formation and how RAEs influence streamer dynamics during ultra-fast gas breakdown process.
Effect of ion collision on separation between light and heavy ions in multi-component vacuum arc
Authors: Sun Qiang , Zhou Qianhong , Yang Wei , Dong Ye , Zhang Hantian , Song Mengmeng
Published: August 2023

In multi-component vacuum arc discharge, light ions and heavy ions usually have different spatial distributions of density and velocity. Previous research has suggested that the difference in spatial distribution of light and heavy ions is due to the mixing effect of cathode spot jet. However, in this work, the ion collision is found to be an important factor leading to the separation of light and heavy ions. In this paper, multi-fluid model is used to study the effect of ion collisions on separation mechanism in multi-component vacuum arc. The simulation results show that, during the jet mixing process, the collisions between different ions will reduce the velocity of light ions, and greatly increase the density and temperature. As a result, the pressure expansion of light ions is significantly enhanced. In addition, the collision between different ions will also increase the size of jet mixing region for light ions, which makes the plasma jet of light ions mixing more fully. These effects make their isotropic expansion dominant, and the ion density at the center is not much different from that at the edge. However for heavy ions, the collision between different ions has little influence on their movement. The pressure is far less than the inertia force, so the density of heavy ion mainly distributes along the convection direction, and the center is greater than the edge. This is the main separation mechanism of ion angular flux. It is also found there are three main factors leading to the separation of light and heavy ions: ion mass, ion density and ion temperature. The separation effect can be enhanced by increasing ion temperature, decreasing ion density and selecting electrode components with significant differences in elemental mass. This paper provides an insight into the mechanism of ion separation in multi-component vacuum arc.
Non-ideal program-time conservation in charge trap flash for deep learning
Authors: Shrivastava Shalini , Saraswat Vivek , Dash Gayatri , Chakrabarty Samyak , Ganguly Udayan
Published: August 2023

Training deep neural networks (DNNs) is computationally intensive, but arrays of non-volatile memories such as charge trap flash (CTF) can accelerate DNN operations using in-memory computing. Specifically, the resistive processing unit (RPU) architecture uses a voltage-threshold program with stochastic encoded pulse trains and analog memory features to accelerate vector-vector outer product and weight update for gradient descent algorithms. Although CTF, offering high precision, has been regarded as an excellent choice for implementing RPU, the accumulation of charge due to the applied stochastic pulse trains is ultimately of critical significance in determining the final weight update. In this paper, we report on the non-ideal program-time conservation in CTF through pulsing input measurements. We experimentally measure the effect of pulse width and pulse gap, keeping the total ON-time of the input pulse train constant, and report three non-idealities: (1) the cumulative

V

T

shift reduces when total ON-time is fragmented into a larger number of shorter pulses, (2) the cumulative

V

T

shift drops abruptly for pulse widths <2

μ

s, (3) the cumulative

V

T

shift depends on the gap between consecutive pulses and the

V

T

shift reduction recovers for smaller gaps. We present an explanation based on a transient tunneling field enhancement due to blocking oxide trap-charge dynamics to explain these non-idealities. Identifying and modeling the responsible mechanisms and predicting their system-level effects during learning is critical. This non-ideal accumulation is expected to affect algorithms and architectures relying on devices for implementing mathematically equivalent functions for in-memory computing-based acceleration.
Experimental study and modeling of rubber joints for railway vehicles using magnetorheological shear stiffening elastomers
Authors: Gong Liping , Gong Ning , Wang Bochao , Yang Jian , Du Haiping , Sun Shuaishuai , Zhang Shiwu , Li Weihua
Published: August 2023

With the rapid development of transportation industry, advanced rail vehicle technology receives more attention than ever. The stiffness of the train’s rubber joint at the primary suspension system has a crucial influence on the operation stability and curve-passing performance. When the train is running on straight track at high speed, a high primary longitudinal stiffness in bogie design is required, whereas running on the curve track calls for a soft primary longitudinal stiffness. To solve this critical problem, a new rubber joint based on magnetorheological shear stiffening elastomer (MSSE) was proposed. Its stiffness can be adjusted by not only external magnetic field but also its inherent frequency-dependent property, ensuring the functionality of the rubber joint even when the controller fails. The prototype of the MSSE joint was fabricated and assembled. Stiffness controllability of the MSSE joint was evaluated using an material testing system (MTS) machine, with MTS testing performed under varying displacement amplitude at fixed frequency to investigate the influence of the varying displacement amplitude on the effective stiffness. The results revealed that the stiffness of this MSSE joint can be controlled effectively credited to the rate-dependent SSE and adjustable electromagnetics, exhibiting exceptional fail-safe characteristics. Lastly, a dynamic model was established to describe the dynamic performance of the rubber joint. All the above studies demonstrate the feasibility of the joint to satisfy the conflicting stiffness requirements to achieve high speed stability and curve trafficability simultaneously.
Dynamic magnetic properties of magnetosomes
Authors: Camp Philip J
Published: August 2023

Magnetosomes are found in magnetotactic bacteria, and consist of linear chains of tens of single-domain magnetic nanoparticles of

F
e

3

O

4

(magnetite) or

F
e

3

S

4

(greigite), enclosed in a lipid bilayer membrane. The particles are typically in the size range 30–

120
 

n
m

, and are practically monodisperse. Harnessing the power of biomineralisation could lead to efficient strategies for synthesising semiflexible dipolar filaments, and the development of optimum materials for applications, including in biomedicine. Brownian dynamics simulations of noninteracting magnetosomes, containing

1
⩽
N
⩽
64

ferromagnetic nanoparticles, have been used to determine static properties, and the dynamical response to a weak AC magnetic field. Results are presented for the radius of gyration

R

g

, the static magnetic susceptibility

χ
(
0
)

, the dynamic magnetic susceptibility

χ
(
ω
)

, and the effective Brownian rotation time

τ

r
o
t

, all as functions of N. The results are compared to theoretical predictions of the flexibility, susceptibility, and rotational dynamics of such magnetic filaments.
Designing CuInSe2 quantum dot-based high-performance Schottky photodetector: a numerical study
Authors: Çadırcı Musa , Yıldız Murat
Published: August 2023

Sensing in the near-infrared and visible wavelengths is critically essential for a broad range of potential applications. Colloidal quantum dot(CQD) based photodetectors provide key advantages, such as spectral tuneability, straight integration with electronic parts, high sensitivity and low cost. Here, a Schottky photodiode architecture based on CuInSe2 (CISe) CQDs structure was designed and its photoresponse characteristics were simulated at various absorber layer thicknesses, at different back contact materials, varying light intensities, several defect densities, and different temperatures. A maximum responsivity of about 0.37 A W−1 was recorded from the proposed device. This work demonstrates that CISe CQDs are potential candidate materials for high-performance Schottky photodetectors operating in the near-infrared and visible electromagnetic spectrum.
Fractional Vieta-Fibonacci wavelets: application for systems of fractionaldelay differential equations
Authors: Azin H , Heydari M H , Baghani O , Mohammadi F
Published: August 2023

In this study, the fractional Vieta-Fibonacci wavelets are introduced. These wavelets are applied to construct a numerical method to solve a class of fractional delay systems of differential equations. To this end, some relationships regarding fractional integration and derivative of these wavelets are extracted at the first. Then, all of the unknown functions in the system under consideration are approximated by these wavelets. Next, by substituting these approximations into the system and applying the collocation method, a system of algebraic equations is obtained. Finally, by solving the extracted system and can determine the unknown coefficients, a solution is obtained for the main system. Moreover, the upper bound of error for approximation with the fractional Vieta-Fibonacci wavelets and the convergence analysis of presented approach is derived. The proposed method is evaluated with solving several examples.
Fusion dynamics of 9Be + 197Au reaction at near and above barrier energies
Authors: Gautam Manjeet Singh , Chahal Rajiv
Published: August 2023

The fusion dynamics of

B

9

e
+

A

197

u

reaction has been investigated theoretically by using classical dynamical model and the energy dependent Woods-Saxon potential (EDWSP) model. Calculations of complete fusion (CF) and total fusion (TF) cross-sections within classical dynamical model are done by using code PLATYPUS and such outputs fairly described CF, ICF and TF yields at above barrier area. However, same calculations failed to reproduce CF and TF cross-sections data at near and below barrier area. In contrast, the EDWSP calculations for CF process at above barrier area are turned out to be suppressed when referenced with CF data while data at sub-barrier energies for complete fusion are reasonably addressed by the model calculations. The EDWSP based suppression has been turned out to be smaller than reported values and with an appropriate scale factor (only at above barrier energies), EDWSP outcomes properly explain CF data in complete range of energy. Further, TF data are adequately addressed by the EDWSP based calculations, thereby, reflects the breakup of weakly bound projectile in the force field of the target isotope. Thus, the weakly bound projectile shows break up effects and partially absorbed by the target, which subsequently gives suppression of the CF yields in above barrier area.
Effect of Frenkel pairs on the tensile and shock compression strength of multi-elemental alloys
Authors: Singh Sandeep Kumar , Parashar Avinash
Published: August 2023

In this article, molecular dynamics simulations were performed to study the effect of irradiation damage on the tensile and shock compression behaviour of multi-elemental alloys (medium and high entropy alloys). These simulations were divided into three broad stages; in the first section, a displacement cascade was generated in the simulation box using primary knock-on atoms (PKA) with kinetic energy in the range of 0.25 to 2 keV. In the second stage, the same defected crystal was subjected to tensile loading to study the deformation mechanism of multi-elemental alloys containing these irradiation-induced defects. In the last stage, tensile loading was replaced by ultrashort shock pulse loading. Irradiation damage significantly alters the tensile strength of Fe–Ni–Co–Cr–Cu and Fe–Ni–Cr alloys. The primary deformation governing mechanism is the spatial distribution of stacking faults and partial dislocations during deformation. Lattice distortion reduces the tensile strength of multi-elemental alloys compared to A-atom configurations. In shock loading, the shock resistance capability of irradiated Fe–Ni–Co–Cr–Cu was better than Fe–Ni–Cr alloy. Lattice distortion in random multi-elemental alloys helps in mitigating the shock propagation.