bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anomalous dielectric response in the triple perovskite ruthenate Ba3BiRu2O9
Authors: Kumar Jitender , Dey Kaustav , Panja Soumendra Nath , Nair Sunil 
Published: September 2022

Abstract
We have investigated the magnetic, dielectric and thermal properties of the S

R
u

= 1 magnetic dimer Ba3BiRu2O9, which is known to exhibit a spin-gap opening in conjunction with a first-order magneto-elastic phase transition at ∼175 K. Above the spin-gap temperature, the temperature dependence dielectric constant shows a peak like feature with pronounced frequency dependence. The critical slowing down behavior of this frequency dispersion suggests that a ferroelectric relaxor like electrical glassy state exists above the spin-gap opening temperature regime. The extermination of frequency dispersion—right at the magneto-elastic phase transition, is suggestive of a strong coupling between the lattice and charge-spin degrees of freedom in this triple perovskite system.
Excitonic instability in transition metal dichalcogenides
Authors: Martins Quintela M F C , Costa A T , Peres N M R 
Published: September 2022

Abstract
When transition-metal dichalcogenide monolayers lack inversion symmetry, their low-energy single particle spectrum near some high-symmetry points can, in some cases, be described by tilted massive Dirac Hamiltonians. The so-called Janus materials fall into that category. Inversion symmetry can also be broken by the application of out-of-plane electric fields, or by the mere presence of a substrate. Here we explore the properties of excitons in TMDC monolayers lacking inversion symmetry. We find that exciton binding energies can be larger than the electronic band gap, making such materials promising candidates to host the elusive exciton insulator phase. We also investigate the excitonic contribution to their optical conductivity and discuss the associated optical selection rules.
Can armchair nanotubes host organic color centers?
Authors: Eller Benjamin , Fortner Jacob , Kłos Jacek , Wang YuHuang , Clark Charles W 
Published: September 2022

Abstract
We use time-dependent density functional theory to investigate the possibility of hosting organic color centers in (6, 6) armchair single-walled carbon nanotubes, which are known to be metallic. Our calculations show that in short segments of (6, 6) nanotubes

∼
5

nm in length there is a dipole-allowed singlet transition related to the quantum confinement of charge carriers in the smaller segments. The introduction of

s

p
3

defects to the surface of (6, 6) nanotubes results in new dipole-allowed excited states. Some of these states are redshifted from the native confinement state of the defect-free (6, 6) segments; this is similar behavior to what is observed with

s

p
3

defects to exciton transitions in semiconducting carbon nanotubes. This result suggests the possibility of electrically wiring organic color centers directly through armchair carbon nanotube hosts.
Thermoelectric transport properties of XAgP (X = Sr and Ba) from first principles
Authors: Dhawan Rakshanda , Zeeshan Mohd , Nautiyal Tashi , van den Brink Jeroen , Kandpal Hem C 
Published: September 2022

Abstract
For thermoelectric applications those materials are of interest that have significant power factor (PF) and low lattice thermal conductivity,

κ

L

. Here we theoretically explore

κ

L

of two novel materials SrAgP and BaAgP using linearized Boltzmann transport equation with a single-mode relaxation time approach. We estimate the figure of merit zT by employing ab-initio calculations based on density functional theory and semiclassical Boltzmann transport theory. It is observed that at room temperature SrAgP exhibits slightly higher lattice thermal conductivity than BaAgP, which is mainly due to the large phonon group velocity. The relaxation time derived from deformation potential theory indicates a higher p-type PF for SrAgP compared to BaAgP over the entire temperature range. This provides an estimate for the figure of merit for the two materials. The low lattice thermal conductivity and higher PF make SrAgP a more promising thermoelectric material.
Early fault diagnosis of rolling bearings based on parameter-adaptive multipoint optimal minimum entropy deconvolution adjusted and dynamic mode decomposition
Authors: Xiong Manman , Lv Yong , Dang Zhang , Yuan Rui , Song Hao 
Published: September 2022

Abstract
Fault vibration signals of rolling bearings in early stages are affected by complex transmission paths and strong background noise, resulting in weak information about fault characteristics, which is difficult to extract clearly and accurately. To this end, a new diagnosis method for early faults of rolling bearings is proposed. First, the parameter-adaptive multipoint optimal minimum entropy deconvolution adjusted (PA-MOMEDA) algorithm is used to preprocess the fault signals by strengthening their shock components and weakening the influence of noise on their results. Second, the maximum envelope-spectrum characteristic energy ratio is employed as the selection criterion for the optimal truncation order of dynamic mode decomposition (DMD) to decompose and reconstruct the signals. Finally, the processed signals are subjected to the Hilbert envelope spectral transformation to accurately extract early fault characteristic frequencies. An analysis of simulated signals, public database signals, and bearing signals from a wind turbine has shown that the proposed PA-MOMEDA–DMD method can successfully extract the early fault characteristics of rolling bearings. Compared with the traditional pattern decomposition algorithms, the proposed method is much better at extracting fault characteristics and diagnosing early faults of rolling bearings. The facts have proved that the proposed method is promising in engineering applications.
Analysis of electrospinning and additive effect on β phase content of electrospun PVDF nanofiber mats for piezoelectric energy harvester nanogenerators
Authors: Oflaz Kamil , Özaytekin İlkay 
Published: September 2022

Abstract
Harvesting energy with piezoelectric nanoparticles enables the development of self-powered devices. Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF) has been widely used in a variety of fields due to its superior piezoelectric properties. PVDF’s piezoelectric performance is affected by the presence of polar phase in the crystalline structure. The electrospinning process was used in this study to achieve high β phase ratios in the PVDF crystalline structure using various additives (graphene, boron nitride, and quartz (SiO2)). The Taguchi experimental design method was used to determine the most significant parameters affecting β phase content from seven factors, as well as the optimal levels of the significant factors. The Fourier transform infrared, x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray and differential scanning calorimetry analyses were used to characterize the composite PVDF nanofiber mats produced under optimal conditions, and the output voltage was measured using an oscilloscope. The composite PVDF nanofiber mat with the highest β phase concentration demonstrated a maximum output voltage of 8.68 V under optimal conditions, indicating that it outperformed than pure PVDF under equal electrospinning conditions.
Electron transport in quantum channels with spin–orbit interaction: effects of the sign of the Rashba coupling and applications to nanowires
Authors: Gogin Leonid , Rossi Fausto , Dolcini Fabrizio 
Published: September 2022

AbstractWe investigate the effects of the sign of the Rashba spin–orbit coupling (RSOC) on electron transmission through a single-channel nanowire (NW) in the quantum coherent regime. We show that, while for a finite length NW with homogeneous RSOC contacted to two electrodes the sign of its RSOC does not affect electron transport, the situation can be quite different in the presence of an inhomogeneous RSOC and a magnetic field applied along the NW axis. By analyzing transport across an interface between two regions of different RSOC we find that, if the two regions have equal RSOC signs, the transmission within the magnetic gap energy range is almost perfect, regardless of the ratio of the spin–orbit energies to the Zeeman energy. In contrast, when the two regions have opposite RSOC signs and are Rashba-dominated, the transmission gets suppressed. Furthermore, we discuss the implementation on a realistic NW setup where two RSOC regions are realized with suitably coupled gates separated by a finite distance. We find that the low-temperature NW conductance exhibits a crossover from a short distance behavior that strongly depends on the relative RSOC sign of the two regions to a large distance oscillatory behavior that is independent of such relative sign. We are thus able to identify the conditions where the NW conductance mainly depends on the sign of the RSOC and the ones where only the RSOC magnitude matters.
Position-dependent mass with modulated velocity in 1-D heterostructures
Authors: Valencia-Torres R , Avendaño J , García-Ravelo J , Choreño E 
Published: September 2022

Abstract
We study the (1+1)-dimensional Dirac equation for charge carriers in some heterostructures. Both, the mass profile and the modulated Fermi velocity of the quasi-particle, are considered position dependent. We have used mass and Fermi velocity that admit only approximate analytical solutions. However, we also calculate numerically the exact energy spectra of each heterostructure through the corresponding reflection coefficient poles.
Effective field theory of black hole perturbations with timelike scalar profile: formulation
Authors: Mukohyama Shinji , Yingcharoenrat Vicharit 
Published: September 2022

Abstract
We formulate the Effective Field Theory (EFT) of perturbations within scalar-tensor theories on an inhomogeneous background. The EFT is constructed while keeping a background of a scalar field to be timelike, which spontaneously breaks the time diffeomorphism. We find a set of consistency relations that are imposed by the invariance of the EFT under the 3d spatial diffeomorphism. This EFT can be generically applied to any inhomogeneous background metric as long as the scalar profile is everywhere timelike. For completeness, we report a dictionary between our EFT parameters to those of Horndeski theories. Finally, we compute background equations for a class of spherically symmetric, static black hole backgrounds, including a stealth Schwarzschild-de Sitter solution.
Monolithic integration of 1.3 μm asymmetric lasers grown on silicon and silicon waveguides with tapered coupling
Authors: Jia Yanxing , Wang Jun , Ge Qing , Wang Haijing , Li Jiachen , Xiao Chunyang , Ming Rui , Ma Bojie , Liu Zhuoliang , Zhai Hao , Lin Feng , He Weiyu , Yang Yisu , Liu Kai , Huang Yongqing , Ren Xiaomin 
Published: September 2022

Abstract
We proposed a design scheme to enable the monolithic integration between a silicon waveguide and a 1.3 μm wavelength band III–V quantum dot laser, which is epitaxially grown on silicon with an asymmetric structure. The III–V laser is grown in a deep trench of a silicon-on-insulator wafer by the selective area epitaxy technique, and a GaAs coupling layer is inserted into the lower cladding layer of the laser, which can make the optical field distribution of the laser shift down. Besides, a mode-size converter with a three-segment tapered structure is designed to couple the output laser into the standard single-mode silicon waveguide. For the laser, the composition and the thickness of AlGaAs cladding layers and AlGaAs transition layer are optimized based on the optical waveguide theory. When the upper cladding layer is 0.6 μm Al0.7Ga0.3As, the lower cladding layer is 1.2 μm Al0.25Ga0.75As, and the transition layer is 20 nm Al0.45Ga0.55As, the optical confinement factors of the active region and the coupling layer are 45.34% and 40.69%, respectively. Then the length of the mode-size converter with a three-segment tapered structure is further optimized by the mode-matching method. When the lengths of the three tapered structures of the mode-size converter are 50 μm, 53 μm and 10 μm respectively, a coupling efficiency of 65% can be obtained between the laser and the Si waveguide. This scheme is expected to realize the efficient optical coupling between the silicon integrated light source and the silicon waveguide, which will promote the development of silicon monolithic photonic integration.
A Meta-analysis of Molecular Spectroscopy Databases, and Prospects of Molecule Detection with Some Future Facilities
Authors: Liu Xin , Du Fujun 
Published: September 2022

Abstract
Molecules reside broadly in the interstellar space and can be detected via spectroscopic observations. To date, more than 271 molecular species have been identified in interstellar medium or circumstellar envelopes. Molecular spectroscopic parameters measured in laboratory make the identification of new species and derivation of physical parameters possible. These spectroscopic parameters are systematically collected into databases, two of the most commonly used being the CDMS and JPL databases. While new spectroscopic parameters are continuously measured/calculated and added to those databases, at any point in time it is the existing spectroscopic data that ultimately limits what molecules can possibly be identified in astronomical data. In this work, we conduct a meta-analysis of the CDMS and JPL databases. We show the statistics of transition frequencies and their uncertainties in these two databases, and discuss the line confusion problem under certain physical environments. We then assess the prospects of detecting molecules in common ISM environments using a few facilities that are expected to be conducting spectroscopic observations in the future. Results show that CSST/HSTDM and SKA1-mid have the potential to detect some complex organic molecules, or even amino acids, with reasonable assumptions about ISM environments.
Investigation of the Oscillations in a Flare-productive Active Region
Authors: Shi Fanpeng , Ning Zongjun , Li Dong 
Published: September 2022

Abstract
We investigate the oscillations in active region (AR) NOAA 12891, which produces a C2.0 three-ribbon flare accompanying a jet on 2021 November 2. Using the data from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory, the 5 minutes decayless kink oscillations of coronal loops were detected and they are independent of the solar flare. Based on the observed oscillations and seismological diagnostics, we estimate that the Alfvén speed and magnetic field in these coronal loops are around 466 km s−1 and 7.6 G, respectively. Additionally, the flare-related jet shows its plasmoids with 1 minute periodicity same as the intensity fluctuation of nearby flare ribbon. The correlation between the intensity fluctuation of jet and that of flare ribbon indicates that their 1 minute oscillations should originate from the same reconnection process.
Evolution of Close Binary System Parameter Distributions
Authors: Zeleke Dugasa Belay , Negu Seblu Humne , Malkov Oleg Yu. 
Published: September 2022

Abstract
In this paper, we investigate the orbital and stellar parameters of low- and intermediate-mass close binary systems. We use models, presented in the catalog of Han et al. and calculate parameters of accretors. We also construct distributions of systems along luminosity, semimajor axis and angular momentum, and make some conclusions on their evolution with time. We compare the results with observational data and it shows a good agreement. The set of theoretical models published quite adequately describes the observational data and, consequently, can be used to determine the evolutionary path of specific close binary systems, their initial parameter values and final stages.
A formalism for sequential estimation of neural membrane time constant and input–output curve towards selective and closed-loop transcranial magnetic stimulation
*
Authors: Alavi S M Mahdi , Vila-Rodriguez Fidel , Mahdi Adam , Goetz Stefan M 
Published: September 2022

Abstract

Objective. To obtain a formalism for real-time concurrent sequential estimation of neural membrane time constant and input–output (IO) curve with transcranial magnetic stimulation (TMS). Approach. First, the neural membrane response and depolarization factor, which leads to motor evoked potentials with TMS are analytically computed and discussed. Then, an integrated model is developed which combines the neural membrane time constant and IO curve. Identifiability of the proposed integrated model is discussed. A condition is derived, which assures estimation of the proposed integrated model. Finally, sequential parameter estimation (SPE) of the neural membrane time constant and IO curve is described through closed-loop optimal sampling and open-loop uniform sampling TMS. Without loss of generality, this paper focuses on a specific case of commercialized TMS pulse shapes. The proposed formalism and SPE method are directly applicable to other pulse shapes. Main results. The results confirm satisfactory estimation of the membrane time constant and IO curve parameters. By defining a stopping rule based on five times consecutive convergence of the estimation parameters with a tolerances of 0.01, the membrane time constant and IO curve parameters are estimated with 82 TMS pulses with absolute relative estimation errors (AREs) of less than 4% with the optimal sampling SPE method. At this point, the uniform sampling SPE method leads to AREs up to 16%. The uniform sampling method does not satisfy the stopping rule due to the large estimation variations. Significance. This paper provides a tool for real-time closed-loop SPE of the neural time constant and IO curve, which can contribute novel insights in TMS studies. SPE of the membrane time constant enables selective stimulation, which can be used for advanced brain research, precision medicine and personalized medicine.
Short pulses of epiretinal prostheses evoke network-mediated responses in retinal ganglion cells by stimulating presynaptic neurons
Authors: Roh Hyeonhee , Otgondemberel Yanjinsuren , Im Maesoon 
Published: September 2022

Abstract

Objective. Microelectronic retinal implant aims to restore functional vision with electric stimulation. Short pulses are generally known to directly activate retinal ganglion cells (RGCs) with a notion of one or two spike(s) per pulse. In the present work, we systematically explore network-mediated responses that arise from various short pulses in both normal and degenerate retinas. Approach. Cell-attached patch clamping was used to record spiking responses of RGCs in wild-type (C57BL/6J) and retinal degeneration (rd10) mice. Alpha RGCs of the mouse retinas were targeted by their large soma sizes and classified by their responses to spot flashes. Then, RGCs were electrically stimulated by various conditions such as duration (100–460 μs), count (1–10), amplitude (100–400 μA), and repeating frequency (10–40 Hz) of short pulses. Also, their responses were compared with each own response to a single 4 ms long pulse which is known to evoke strong indirect responses. Main results. Short pulses evoked strong network-mediated responses not only in both ON and OFF types of RGCs in the healthy retinas but also in RGCs of the severely degenerate retina. However, the spike timing consistency across repeats not decreased significantly in the rd10 RGCs compared to the healthy ON and OFF RGCs. Network-mediated responses of ON RGCs were highly dependent on the current amplitude of stimuli but much less on the pulse count and the repetition frequency. In contrast, responses of OFF RGCs were more influenced by the number of stimuli than the current amplitude. Significance. Our results demonstrate that short pulses also elicit indirect responses by activating presynaptic neurons. In the case of the commercial retinal prostheses using repeating short pulses, there is a possibility that the performance of clinical devices is highly related to the preserved retinal circuits. Therefore, examination of surviving retinal neurons in patients would be necessary to improve the efficacy of retinal prostheses.
Engineering resiliency in UAV swarms–A bibliographic analysis
Authors: Phadke Abhishek , Antonio Medrano F. , Chu Tianxing 
Published: September 2022

Abstract
An Unmanned Aerial Vehicle (UAV) swarm is essentially a network of UAV agents in which coordinating interaction and dependencies are important for successful mission execution. However, the environment that they work in is susceptible to many potential disruptions, such as external weather factors or internal component malfunctions. These disrupt operation and adversely impact overall system performance. To prevent a high rate of mission failure, UAV swarms must exhibit a certain degree of resiliency to disruptions. This study conducts a bibliographical analysis of research on resiliency in UAV swarms over the last decade, and key insights into essential constructs necessary to engineer resilient behavior in UAV swarms are documented. This study also lays the groundwork for future analysis on UAV swarms, with a particular focus on incorporating resiliency to improve performance in the face of disruptions.
Development of an open-source large 3D printer for PLA and ABS
Authors: Barbosa William S. , Gouvea Felipe C. , Wanderley Renan F. F. , Gonçalves Flavia M. 
Published: September 2022

Abstract
The use of 3D printers in additive manufacturing are very common at the last years. The structure, size, movements and type of materials of the printers changes according the use, topology and form of the object that be printed. Although 3D printers are becoming more widespread in the industry and for residential consumers, the size and density of pieces is still a challenge principally at larger pieces. This paper presents all details and specifications of an open-source large 3D printer that uses PLA or ABS, with the aim to verify the impact of these transformations and uses for engineering and industry in general.
Stability analysis of foundation pit against uplift based on circular sliding
Authors: Guo Zhiguang , Liu Yongfu , Zhang Fan 
Published: September 2022

Abstract
The analytical solution of the basal stability coefficient for the excavation is obtained, basing on the principle of mechanical balance and the theory of calculus. The programmatic calculation of the analytical solution is realized with the VB6.0 platform. Furthermore, the factors affecting the basal stability of excavation are analyzed and utilized by the program, including the support position, the construction load, the pile length and cohesion of soil layer at pile bottom. The results show that the construction load has little effect on the stability coefficient. And the closer the bottom steel support is to the bottom of the excavation, the worse the stability of the excavation is. Moreover, as the length of the pile increases (i.e., the radius of the arc increases), the stability factor increases first and then decreases, and its peak occurs when the pile length is 16 m. In addition, the basal stability of excavation will be increased when the pile bottom is cohesive soil.