bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low terahertz frequency on-chip multi-functional modulator with amplitude and phase modulation
Authors: Liang Huajie , Zeng Hongxin , Zhao Hanyu , Wang Lan , Liang Shixiong , Feng Zhihong , Yang Ziqiang , Zhang Yaxin 
Published: November 2023

Abstract
Terahertz amplitude and phase modulation technologies are crucial for terahertz communication, radar, and imaging. However, most current approaches can only achieve either amplitude or phase modulation. In this paper, we present a low terahertz frequency on-chip multi-functional modulator that consists of a hybrid coupler and reflection meta-structure. High-performance amplitude modulation is achieved by combining series resonant absorption of series coupling branch with resonance enhancement of parallel coupling branch in the reflection meta-structure. Meanwhile, the enhanced resonance provides a larger range of phase shifts, enabling effective amplitude and phase modulation in two different frequency regions. Therefore, we realize an amplitude modulation in the range of 115–135 GHz with a minimum transmission loss of 4 dB and a modulation depth of over 10 dB. At the same time, we achieved a continuous phase shift in the 103–113 GHz region, as well as a 180° two-bit phase shift in the 107–109 GHz range with only 5.7 dB transmission loss. Our simple method for terahertz amplitude and phase multi-functional modulation offers the potential to construe terahertz multifunctional integrated systems.
Energy and system size dependence of strongly intensive fluctuation measures in heavy-ion collisions at FAIR energies
Authors: Ali Bushra , Ahmad Shakeel , Ahmad A 
Published: November 2023

Abstract
Event-by-event fluctuations of multiplicity and transverse momentum of charged hadrons produced in heavy-ion collisions at FAIR energies, 10A, 20A, 30A, and 40A GeV are studied in the framework of relativistic transport model, URQMD. Dependence of two families of strongly intensive measures of multiplicity(N) and transverse momentum (p
T) fluctuations, Δ[p
T, N] and Σ[p
T, N], on collision centrality, centrality bin-widths and pseudorapidity windows are examined. Attempts are also made to study NN, N
p
T, and p
T
p
T fluctuations using two window analysis method. The findings suggest that the measure, Δ[p
T, N] be dealt with proper selection of centrality intervals. This measure also exhibits a strong dependence on the widths of η windows. The variable Σ[p
T, N], however, is observed to be insensitive to the centrality bin-widths and shows a variation of <5% with the widths of η windows. The analysis of data after event mixing gives Δ[p
T, N] and Σ[p
T, N] values as ∼1 irrespective of the widths of η windows and collision centrality, as predicted by a model of independent particle emission, IPM. The study of joint fluctuations of the two quantities on two η windows separated in η space, reveals that Σ[N
F, N
B] values are ∼1 irrespective of the position of η windows whereas, the values of

Σ
[

N

F

,

p

T

B

]

and

Σ
[

p

T

F

,

p

T

B

]

firstly increase with η
sep and later acquire saturations. The observed trend of centrality dependence of

Σ
[

N

F

,

N

B

]
,
Σ
[

N

F

,

p

T

B

]

and

Σ
[

p

T

F

,

p

T

B

]

agrees fairly well with those observed in MC simulated studies carried out for AA collisions at LHC energies in the framework model of string fusion.
Influence of magnetic field on the electronic ferroelectricity in the extended Falicov-Kimball model
Authors: Farkašovský Pavol 
Published: November 2023

Abstract
The density-matrix-renormalization-group method is used to study the influence of external magnetic field on the stability of the excitonic phase induced by local hybridization in the one-dimensional spin-1/2 Falicov-Kimball model. It is shown that a fine tuning of external magnetic field through the quantum critical point is able to induce significant changes (continuous as well as discontinuous) in the excitonic

⟨

d
+

f
⟩

expectation average providing new set of physical properties and technological applications, like possibilities of faster switching ferroelectrics and controlling their optical properties with magnetic fields. Moreover, effects of some other interactions (which may be present in real d-f materials) on the stability of excitonic phase are examined and it is shown that the Hubbard interaction in the d-electron subsystem, the interband d-f Coulomb interaction, as well as the exchange d-f interaction stabilize significantly excitonic correlations below the quantum critical point, while the anisotropic spin-dependent interaction of the Ising type between f and d electrons as well as the f-electron hopping suppress the excitonic correlations for magnetic fields below as well as above the quantum critical point.
Emulation of Pavlovian conditioning and pattern recognition through fully connected neural networks using Holmium oxide (Ho2O3) based synaptic RRAM device
Authors: Jetty Prabana , Kannan Udaya Mohanan , Narayana Jammalamadaka S 
Published: November 2023

Abstract
In this manuscript, we report on the paramagnetic Ho2O3-based synaptic resistive random-access memory device for the implementation of neuronal functionalities such as long-term potentiation, long-term depression and spike timing dependent plasticity respectively. The plasticity of the artificial synapse is also studied by varying pulse amplitude, pulse width, and pulse interval. In addition, we could classify handwritten Modified National Institute of Standards and Technology data set (MNIST) using a fully connected neural network (FCN). The device-based FCN records a high classification accuracy of 93.47% which is comparable to the software-based test accuracy of 97.97%. This indicates the highly optimized behavior of our synaptic device for hardware neuromorphic applications. Successful emulation of Pavlovian classical conditioning for associative learning of the biological brain is achieved. We believe that the present device consists the potential to utilize in neuromorphic applications.
Contact resonance atomic force microscopy using long elastic tips
Authors: Zimron-Politi Nadav , Tung Ryan C 
Published: November 2023

Abstract
In this work, a new theoretical model for contact resonance atomic force microscopy, which incorporates the elastic dynamics of a long sensing tip is presented. The model is based on the Euler–Bernoulli beam theory and includes coupling effects from the two-beam structure, also known as an ‘L-shaped’ beam in the literature. Here, high-accuracy prediction of the sample stiffness, using several vibration modes with a relative error smaller than 10% for practical working ranges, is demonstrated. A discussion on the model’s capability to predict the dynamic phenomena of eigenmode veering and crossing, as the force applied to the sample increases, is presented. The L-shaped beam model presented here is also applicable for structural applications such as: micro-electro-mechanical systems, energy harvesting, and unmanned aerial vehicle landing gear.
Ultrahigh responsivity of non-van der Waals Bi2O2Se photodetector
Authors: Lakhchaura Suraj , Gokul M A , Rahman Atikur 
Published: November 2023

Abstract
Bismuth oxyselenide has recently gained tremendous attention as a promising 2D material for next-generation electronic and optoelectronic devices due to its ultrahigh mobility, moderate bandgap, exceptional environmental stability, and presence of high-dielectric constant native oxide. In this study, we have synthesized single-crystalline nanosheets of Bismuth oxyselenide with thicknesses measuring below ten nanometers on Fluorophlogopite mica using an atmospheric pressure chemical vapor deposition system. We transferred as-grown samples to different substrates using a non-corrosive nail polish-assisted dry transfer method. Back-gated Bi2O2Se field effect transistors showed decent field effect mobility of 100 cm2 V−1s−1. The optoelectronic property study revealed an ultrahigh responsivity of 1.16 × 106 A W−1 and a specific detectivity of 2.55 × 1013 Jones. The samples also exhibited broadband photoresponse and gate-tunable photoresponse time. These results suggest that Bi2O2Se is an excellent candidate for future high-performance optoelectronic device applications.
Path-dependent shrinking target problems in beta-dynamical systems
Authors: He Yubin 
Published: November 2023

Abstract
This paper is concerned with the path-dependent shrinking target problems in beta-dynamical systems. For β > 1 let T

β
be the β-transformation on

[
0
,
1
]

. Let

1
<

β
1

⩽

β
2

, and

f
,
g

be two positive continuous functions. For any

x
0

,

y
0

∈
[
0
,
1
]

, we show that the set

E

T

β
1

,

T

β
2

,
f
,
g

=

x
,
y

∈

0
,
1

2

:

|

T

β
1

n

x
−

x
0

|

<

e

−

S
n

β
1

f

x

|

T

β
2

n

y
−

y
0

|

<

e

−

S
n

β
2

g

y

for infinitely many

n
∈

N

has large intersection property under the condition

β
1

e

min
f
(
x
)

≥

β
2

, where

S
n
β

h
(
x
)

denotes the ergodic sum

∑

j
=
0

n
−
1

h
(

T
β
j

x
)

. Consequently, we can determine the Hausdorff dimension of

E
(

T

β
1

,

T

β
2

,
f
,
g
)

, which is the solution to some modified pressure function defined through singular value function.
Exploration of differentiability in a proton computed tomography simulation framework
Authors: Aehle Max , Alme Johan , Gábor Barnaföldi Gergely , Blühdorn Johannes , Bodova Tea , Borshchov Vyacheslav , van den Brink Anthony , Eikeland Viljar , Feofilov Gregory , Garth Christoph , Gauger Nicolas R , Grøttvik Ola , Helstrup Håvard , Igolkin Sergey , Keidel Ralf , Kobdaj Chinorat , Kortus Tobias , Kusch Lisa , Leonhardt Viktor , Mehendale Shruti , Ningappa Mulawade Raju , Harald Odland Odd , O’Neill George , Papp Gábor , Peitzmann Thomas , Pettersen Helge Egil Seime , Piersimoni Pierluigi , Pochampalli Rohit , Protsenko Maksym , Rauch Max , Ur Rehman Attiq , Richter Matthias , Röhrich Dieter , Sagebaum Max , Santana Joshua , Schilling Alexander , Seco Joao , Songmoolnak Arnon , Sudár Ákos , Tambave Ganesh , Tymchuk Ihor , Ullaland Kjetil , Varga-Kofarago Monika , Volz Lennart , Wagner Boris , Wendzel Steffen , Wiebel Alexander , Xiao RenZheng , Yang Shiming , Zillien Sebastian 
Published: November 2023

Abstract

Objective. Gradient-based optimization using algorithmic derivatives can be a useful technique to improve engineering designs with respect to a computer-implemented objective function. Likewise, uncertainty quantification through computer simulations can be carried out by means of derivatives of the computer simulation. However, the effectiveness of these techniques depends on how ‘well-linearizable’ the software is. In this study, we assess how promising derivative information of a typical proton computed tomography (pCT) scan computer simulation is for the aforementioned applications. Approach. This study is mainly based on numerical experiments, in which we repeatedly evaluate three representative computational steps with perturbed input values. We support our observations with a review of the algorithmic steps and arithmetic operations performed by the software, using debugging techniques. Main results. The model-based iterative reconstruction (MBIR) subprocedure (at the end of the software pipeline) and the Monte Carlo (MC) simulation (at the beginning) were piecewise differentiable. However, the observed high density and magnitude of jumps was likely to preclude most meaningful uses of the derivatives. Jumps in the MBIR function arose from the discrete computation of the set of voxels intersected by a proton path, and could be reduced in magnitude by a ‘fuzzy voxels’ approach. The investigated jumps in the MC function arose from local changes in the control flow that affected the amount of consumed random numbers. The tracking algorithm solves an inherently non-differentiable problem. Significance. Besides the technical challenges of merely applying AD to existing software projects, the MC and MBIR codes must be adapted to compute smoother functions. For the MBIR code, we presented one possible approach for this while for the MC code, this will be subject to further research. For the tracking subprocedure, further research on surrogate models is necessary.
High inductance magnetic-core coils have enhanced efficiency in inducing suprathreshold motor response in rats
Authors: Nguyen Hieu , Makaroff Sergey N , Li Charlotte Qiong , Hoffman Samantha , Yang Yihong , Lu Hanbing 
Published: November 2023

Abstract

Objective. Transcranial magnetic stimulation (TMS) coil design involves a tradeoff among multiple parameters, including magnetic flux density (B), inductance (L), induced electric (E) field, focality, penetration depth, coil heating, etc. Magnetic materials with high permeability have been suggested to enhance coil efficiency. However, the introduction of magnetic core invariably increases coil inductance compared to its air-core counterpart, which in turn weakens the E field. Our lab previously reported a rodent-specific TMS coil with silicon steel magnetic core, achieving 2 mm focality. This study aims to better understand the tradeoffs among B, L, and E in the presence of magnetic core. Approach. The magnetic core initially operates within the linear range, transitioning to the nonlinear range when it begins to saturate at high current levels and reverts to the linear range as coil current approaches zero; both linear and nonlinear analyses were performed. Linear analysis assumes a weak current condition when magnetic core is not saturated; a monophasic TMS circuit was employed for this purpose. Nonlinear analysis assumes a strong current condition with varying degrees of core saturation. Main results. Results reveal that, the secondary E field generated by the silicon steel core substantially changed the dynamics during TMS pulse. Linear and nonlinear analyses revealed that higher inductance coils produced stronger peak E fields and longer E field waveforms. On a macroscopic scale, the effects of these two factors on neuronal activation could be conceptually explained through a one-time-constant linear membrane model. Four coils with different B, L, and E characteristics were designed and constructed. Both E field mapping and experiments on awake rats confirmed that inductance could be much higher than previously anticipated, provided that magnetic material possesses a high saturation threshold. Significance. Our results highlight the novel potentials of magnetic core in TMS coil designs, especially for small animals.
Ferroelectric film-based stretch sensor with successive stretch and release motions characterized by a combined piezoelectric and electrostrictive effect
Authors: Feng Guo-Hua , Yeh Chih-Ting 
Published: November 2023

Abstract
A stretch sensor fabricated from a hydrothermally grown ferroelectric PZT film on titanium foil was developed. The unique sensor structure effectively converts the stretching motion of the PZT film to an out-of-plane deformation with a linear strain variation. An experiment with a strain-stretch displacement of more than 10% was conducted using the sensor anchored on a silicone rubber plate. The induced polarization of the PZT film was linearly converted into a voltage output through the sensing circuit. The combined piezoelectric and electrostrictive effects are proposed to characterize the experimental results. Based on both the elastic Gibbs energy and piezoelectric theory, we derive a mathematical equation relating the strain and polarization of the PZT film. The measured stretch displacement and voltage data exhibited an excellent fit with the derived equation. An identical repeated motion can be sequenced by the memorized function of the sensor using the constant term of the fitting curve. With the characterized results, the computed displacement matched well with the measured displacement for repeated cyclic motions, with a correlation coefficient greater than 0.99. Compared with the simple piezoelectric effect, the more accurate displacement obtained via the detected voltage will significantly benefit wearable stretch sensors based on ferroelectric films.
Analysis of a non-integer order compartmental model for cholera and COVID-19 incorporating human and environmental transmissions
Authors: Usman Muhammad , Abbas Mujahid , Omame Andrew 
Published: November 2023

Abstract
Fractional differential operators have increasingly gained wider applications in epidemiological modelling due to their ability to capture memory effect in their definitions; an attribute which lacks in the concept of classical integer derivatives. In this paper, employing the Caputo fractional operator with singular kernel, the co-dynamical model for cholera and COVID-19 diseases is proposed and analyzed, incorporating both direct and indirect transmission routes for cholera. The necessary conditions for existence of the unique solution of the proposed model are studied. Using the results from fixed point theory, Ulam-Hyers stability analysis of the system is performed. The model is fitted to real data from Pakistan and the optimized order of the fractional derivative for which the system fits well to data is obtained. Other numerical assessments of the model are also executed. Phase portraits of the infected classes with different initial conditions and various order of the fractional derivative are obtained in the cases when the reproduction number



0

<
1

and



0

>
1

. It is observed that the trajectories for the infected compartments tend towards the infection-free steady state when



0

<
1

and the endemic steady state when



0

>
1

irrespective of the initial conditions and the order of the fractional derivative. Increment in the COVID-19 vaccine efficacy, keeping the vaccination rate fixed at

δ

1

ω

=
0.8

, resulted in a decline in the COVID-19 disease. Also, increasing the COVID-19 vaccination rate, keeping the vaccine efficacy for COVID-19 fixed at

ϕ

c

ω

=
0.85

, led to a decline in the COVID-19 associated reproduction number. The simulations also pointed out the impact of COVID-19 and cholera vaccinations, direct and indirect transmissions of cholera.
Qualitative aspects and sensitivity analysis of MERS-Corona epidemic model with and without noise
Authors: Alqahtani Hessah , Badshah Qaisar , Sakhi Shazia , ur Rahman Ghaus , Gómez-Aguilar J F 
Published: November 2023

Abstract

Background. MERS-CoV (Middle East Respiratory Syndrome Coronavirus) is a severe respiratory illness that poses a significant threat to the Arabic community and has the potential for global spread. In this paper, we present deterministic and stochastic models to study the dynamics of MERS infection within hosts. Objective. For the purpose of describing the dynamics of MERS transmission throughout host populations, a deterministic model is created. To gauge the likelihood of an epidemic spreading, the reproduction number is calculated. Furthermore, Lyapunov function theory is used to assess the stability of the deterministic model. In order to account for the intrinsic heterogeneity in the disease dynamics, a stochastic model is also developed. In order to verify the analytic conclusions and learn more about the behavior of the system, numerical simulations are carried out. Methods. Investigating the reproduction rate yields vital details about MERS’s capacity to start an outbreak. The stability analysis based on Lyapunov function theory sheds light on the deterministic model’s long-term behavior. The analytical results are supported by numerical simulations, which also provide a thorough insight into the dynamics of the disease. Conclusion. The deterministic and stochastic models for MERS infection inside hosts are thoroughly examined in this paper. Our knowledge of the dynamics of the disease and its potential for epidemic transmission is improved by the examination of the reproduction number and stability analysis. The combination of analytical and numerical approaches contributes to a more comprehensive assessment of MERS-CoV and aids in informing public health interventions and control strategies.
Six-element MIMO antenna structure with squared ring structure with multiband and high gain characteristics for C/X/Ku/K band applications
Authors: Almawgani Abdulkarem H M , Sorathiya Vishal , Dabhi Vipul M , Alhawari Adam R H , Salleh Mohd Fadzli Mohd 
Published: November 2023

Abstract
Using ring resonator structure, we have presented a structure of the six-element multiple input multiple output (MIMO) antenna structure. The proposed structure is numerically investigated and experimentally verified for antenna performance in the 1 to 25 GHz wideband frequency range. We have designed and verified the five antenna structure types, which consist of the various forms of ring/patch with different ground plane geometries. Various performance parameters like gain, directivity, reflections, and electric field distributions are analyzed for MIMO antennas. Essential performanceparameters observed for the MIMO antennas are also presented in this manuscript to identify the behaviour of the structure with different physical conditions. These parameters are also investigated for the identification of suitable ranges for the multi-channel transmission capability of the communication system. Return loss and Gain values are< −12 dB and ∼ 20 dBi achieved with ∼12 GHz of the operating bandwidth. Overall, the antenna offers minimum return loss values of −25 dB for the operating band of 19 to 25 GHz with anoperational bandwidth of 6 GHz. The designed antennas are tested using a ground patch and a rectangular patch in a scattered manner, and the obtained results are utilized in the Ultrawideband MIMO antenna applications. These antennas are also used in various band operations in satellite communication, including C/X/Ku/K bands.
Atomic structure calculations, and electron impact ionization cross-sections of W LXI
Authors: El-Maaref A A 
Published: November 2023

Abstract
The present study provides a wide range of calculations of atomic structure data for the tungsten ion W LXI, that belongs to the silicon isoelectronic sequence. The fully relativistic Multi-configuration Dira-Hartree–Fock (MCDHF) method including configuration interaction (CI) is applied to the current ion. Calculated results of energy levels, oscillator strengths, and radiative rates of W LXI are presented. A set of two configuration state lists including the configurations of 3s23p2, 3s3p3, 3s23p3d, and 3p4 at different angular momenta (J) and parity (P) are considered in the configuration interaction calculations of level energies and oscillator strengths. To increase the accuracy of the results, the electronic correlations from higher orbitals, i.e., 7l orbitals are included in the calculations. Quantum electrodynamics effects such as vacuum polarization and self-energy are recalled in the CI calculations. Many more transitions in the soft x-ray region (between 20 and 200 angstroms) have been identified. The flexible atomic code package has been used to compute the electron impact ionization cross-sections of 3s23p2 3P0,1, 1D2 levels in silicon-like tungsten. The cross-sections of the transitions from the ground level in W LXI to the first levels in the 61st ionization of tungsten have been computed using FAC code. The total ionization cross-sections of the 3s23p2 at electron energy range from 5–35 keV are evaluated as well.