bluuebunny/crossref_metadata_2025 huggingface dataset:
Process development and validation of next generation 3D calibration standards for application in optical microscopy
Authors: Hellmich Celina , Heinrich Lena , Hemmleb Matthias , Bütefisch Sebastian , Weimann Thomas , Kroker Stefanie
Published: May 2024

A scalable wafer-based fabrication process for a new generation of 3D standards enabling the 3D calibration of optical microscopes is presented and validated. The 3D standards are based on step pyramids with several layers in the µm range and a system of cylindrical knops distributed across the layers as marks for coordinate based calibration. This enables calibration for the three coordinate axes and the orthogonality error between them in a single measurement step. The requirements necessary for such a calibration, as optical non-transparency, reproducible flatness of the pyramid step heights and the lowest possible deviations of the lateral marks coordinates, are met by optimizing the manufacturing process: The deviation of the height steps distributed over the wafer is ±3.6 nm and is primarily caused by the layer deposition processes. The lateral manufacturing accuracy was determined using calibrated scanning electron microscope (SEM) and show a mean deviation of 20 or 60 nm, depending on the lateral size of the structures. The electron beam lithography process and the level of inaccuracy of the SEM standard have an influence on the lateral scaling accuracy. Based on the tactilely generated height values and the coordinates of the mark determined by a calibrated SEM, an example calibration of a confocal laser scanning microscope was successfully performed and showed good conformity to conventional calibration techniques.
PSO-optimized SSLMS adaptive filter for signal denoising of rolling bearings under small sample condition
Authors: Deng Linfeng , Wang Xiaoqiang
Published: May 2024

To address the issue that the deep learning-based denoising algorithms can hardly effectively eliminate the background noise under small sample data condition, this paper proposes a new denoising method based on spectral subtraction (SS) and least mean square (LMS) adaptive filtering algorithms. To achieve the adaptive selection for the parameters of SS and LMS algorithms, particle swarm optimization approach is employed to search and optimize the parameters in the two algorithms, which is helpful for the two algorithms to play an important role in eliminating the noise components with the different properties. Subsequently, the SS algorithm and the LMS algorithm are appropriately combined, and the SS-processed signal is input into the LMS algorithm as a desired signal to actualize the LMS adaptive filtering function. In this way, the denoising performance of both algorithms can be maximally utilized, which achieves effective noise reduction in vibration signal. The effectiveness and superiority of the proposed method are validated through simulation data and rolling bearing experiment data, respectively. The results demonstrate that the proposed method significantly diminishes noise components and retains precise and reliable fault features under small sample data condition, which provides an effective denoising method for rolling bearing vibration signals under small sample data condition in practical engineering scenarios.
Modified

(
n
+
1
)

D Laplacian for smooth pressure reconstruction based on time-resolved velocimetry (1): analysis and numerics
Authors: Zhang Junrong , Sakib Nazmus , Pan Zhao
Published: May 2024

We analyze a smooth pressure solver based on the ‘modified Poisson equation’:

∇
2

p
+

ξ
2

∂
2

p

∂

t
2

=
f
(
u
(
t
)
)
,

where

p

is the pressure field,

u
(
t
)

is the velocity field measured by time-resolved image velocimetry, and

ξ
2

is a tunable parameter to control the solver’s diffusive behaviour in time. This modified Poisson equation aims at obtaining smooth pressure fields from potentially noisy image velocimetry measurements, and is a part of the current four-dimensional (4D) pressure solver (implemented in, for example, DaVis 10.2) by LaVision. This work focuses on investigating three aspects of the ‘modified Poisson equation’: smoothing effect, error propagation, and drift in time. We first provide rigorous analysis and validate that this solver can sufficiently smooth the computed pressure field by setting a large enough

ξ
2

. However, a large value of

ξ
2

may cause large errors in the reconstructed pressure fields. Then we introduce an upper bound on the error in the reconstructed pressure fields to quantify the error propagation dynamics. Finally, we discuss the potential drift due to the partitioning in time, which is an optional strategy used in LaVision’s current 4D pressure solver to reduce computational costs. Our analysis and validation not only show that careful choice of the parameters (e.g.

ξ
2

) is needed for smooth and accurate pressure field reconstruction but provide theoretical guidelines for parameter tuning when similar pressure solvers are used for time-resolved image velocimetry data.
Research on acoustic methods for buried PE pipeline detection based on LSTM neural networks
Authors: Qi Yongsheng , Wang Xinhua , Yang Xuyun , Sun Tao , Razzaq Izzat , Yang Lin , Wang Yuexin , Rasool Ghulam
Published: May 2024

As an essential component of urban infrastructure construction, polyethylene (PE) pipelines face the challenging task of underground detection due to the complex and dynamic nature of the subsurface environment, diverse installation paths, and the inherent insulating properties of PE materials. In order to address the non-excavation detection of buried PE pipelines, this paper proposes an acoustic method based on the long short-term memory (LSTM) neural network. The study begins by analyzing the propagation and reflection mechanisms of elastic waves in the pipe-soil coupling system, and a impact excitation source is designed to generate the excitation signal. After establishing the experimental environment and collecting experimental data, a comprehensive analysis is conducted, and the LSTM neural network is employed for data classification to determine the presence of buried PE pipelines. Through neural network training, accurate identification of the PE pipeline’s existence and prediction of its burial depth are achieved, providing an efficient and reliable solution for buried PE pipeline detection. The practical results demonstrate the significant application prospects of the combined acoustic method and LSTM neural network in buried PE pipeline detection. This research contributes a novel solution to the field of non-destructive PE pipeline detection, with both theoretical and practical implications.
Low-cost bidirectional coil driver with microamp precision
Authors: Liu Boyao , Allison William
Published: May 2024

We describe a compact constant current power supply with µA precision designed to drive coils. The unit generates currents from −125 mA to 125 mA with a load up to 10 Ω using a precision 16-bit digital to analogue converter, driven from a microcontroller (e.g. Raspberry Pi Pico). All power for the unit is derived from the 5 V of the microcontroller. As a demonstration of the capability of the power supply, it was applied to spin manipulation in a helium spin echo system.
A poly(L-lactic Acid)-based flexible piezoelectric energy harvester with micro-zigzag structures
Authors: Liu Yijie , Xue Yi , He Zifeng , Liang Wolin , Yang Jian , Babichuk Ivan S
Published: May 2024

Piezoelectric energy harvester (PEH) holds great potential for flexible electronics and wearable devices. However, the power conversion efficiency of flexible PEH (fPEH) has often been a limiting factor, especially under variable excitation. Herein, we propose a practical solution: a poly(L-lactic acid)-based fPEH with 3D-printed micro-zigzag structures. This design not only broadens the operational bandwidth and enhances low-frequency response but also offers a tangible improvement in the power conversion efficiency of fPEH. The micro-zigzag structure was designed and fabricated using a digital light processing 3D printing technique with acrylates, a method that is readily accessible to researchers and engineers in the field. Mechanical properties of the 3D-printed acrylic elastomers with different compositions were investigated to obtain the material parameters, and then fPEH with the sandwich structure was fabricated via sputtering and packaging. Subsequently, numerical simulation was conducted on the micro-zigzag structures to determine the structure sizes and oscillation frequencies of fPEH. Finally, four micro-zigzag structures with 3-, 4-, 5- and 6 mm lengths were tested to obtain oscillation frequencies of 51, 37, 22, and 21 Hz consistent with the simulation. The output voltages of fPEH are 11–30 mV with the load ranges of 60–100 MΩ. Stability evaluation showed that the fPEH can work under low frequency (<100 Hz) and broadband conditions. The micro-zigzag structure provided new insights for the design of fPEH, paving the way for more efficient and practical energy harvesting solutions in the future.
Coexistence of asynchronous and clustered dynamics in noisy inhibitory neural networks
Authors: Feld Yannick , Hartmann Alexander K , Torcini Alessandro
Published: May 2024

A regime of coexistence of asynchronous and clustered dynamics is analysed for globally coupled homogeneous and heterogeneous inhibitory networks of quadratic integrate-and-fire (QIF) neurons subject to Gaussian noise. The analysis is based on accurate extensive simulations and complemented by a mean-field description in terms of low-dimensional next generation neural mass models for heterogeneously distributed synaptic couplings. The asynchronous regime is observable at low noise and becomes unstable via a sub-critical Hopf bifurcation at sufficiently large noise. This gives rise to a coexistence region between the asynchronous and the clustered regime. The clustered phase is characterised by population bursts in the γ-range (30–120 Hz), where neurons are split in two equally populated clusters firing in alternation. This clustering behaviour is quite peculiar: despite the global activity being essentially periodic, single neurons display switching between the two clusters due to heterogeneity and/or noise.
Green-Kubo paralell tempering molecular dynamics determination of the thermal conductivity for the wurtzite ZnO: statistical problems of the method
Authors: Alonso-Herrera C A , Mixteco-Sánchez J C , Garibay-Alonso R
Published: May 2024

The thermal conductivity for the wurtzite ZnO is determined in the temperature range from 300 to 1100 K by using parallel tempering molecular dynamics within the Green-Kubo approach and a classical Morse-Born-Mayer-Coulomb hybrid interaction potential. Compared to other previous calculations for the thermal conductivity of common crystals within the same Green-Kubo and molecular dynamics approach, the used parallel tempering scheme shows some appealing improvements in the calculation of the time self-correlation of the heat flux vector, although at the price of using a relatively large number of total computational steps. However, in spite of the found improvements for the calculation of the self-correlation of the heat flux vector, some statistical problems on this point remain on the particular application of the method. Finally, even with the presence of a clear statistical noise, the obtained values and temperature trend of the calculated thermal conductivity shows the classical 1/T decaying behavior reported in previous works for wurtzite ZnO and other related semiconductor systems using the alternative Boltzmann transport equation theory.
Double ferromagnetic barriers resonant tunneling diodes (RTD) based on the surface of a topological insulator
Authors: Vali Mehran
Published: May 2024

Resonant tunneling diodes (RTDs), which are based on double barrier quantum well structures, are typically achieved by combining different materials with varying band gap sizes. However, this approach often poses challenges such as material mismatching and dislocations. In this study, we present a novel resonant tunneling diode scheme utilizing the unique properties of topological insulator materials. Specifically, we exploit the gap opening in the band structure of the topological insulator by employing perpendicular magnetization. In this proposed RTD platform, the barrier regions are formed from a ferromagnetic topological insulator through the proximity effect. By adjusting the thickness and spacing of the ferromagnetic barriers, a well region with confined states emerges between the barrier regions. Theoretical analysis reveals that by tuning the back gate voltage, the I-V characteristics exhibit two significant behaviors: negative differential resistance (NDR) and step-like behavior for Fermi energy values of EF = −3 and EF = 3, respectively. Furthermore, we observe an increase in the peak-to-valley ratio (PVR) with higher magnetization values. Notably, the PVR reaches a value of 7.13 for a magnetization value of m = 9. Additionally, we investigate the influence of the well width and barrier thickness on the transport properties of the device.
Influence of pressure on structural, electronic, optical, and elastic properties of lead-free chalcogen perovskite LaLuS3 via first-principles calculations: implications for optoelectronic applications
Authors: Ullah Sana , Mu Yanqi , Xie Guancai , Gong Jian Ru
Published: May 2024

Chalcogen perovskites have garnered increasing attention as promising materials for optoelectronic applications. In this study, we employed the first-principles method to investigate the structural, electronic, optical, and elastic properties of LaLuS3 under hydrostatic pressure at various levels. Through a thorough analysis of the calculated electronic structures, we observed that LaLuS3 exhibits direct band gaps, with the magnitudes of these gaps changing as the pressure varied. Specifically, the band gaps decrease by 2.19 eV, 2.025 eV, 1.365 eV, and 0.6043 eV at hydrostatic pressures of 0%, 10%, 20%, and 30% GPa, respectively. Furthermore, we observed shifts in the conduction band minimum and valence band maximum positions, indicating the potential of LaLuS3 for perovskite-based devices. This suggests that external pressure can serve as a powerful tool for designing new functional materials with intriguing properties. Our investigation also revealed promising optical properties of LaLuS3 under high pressures, further affirming its potential for optoelectronic and solar cell applications. The optical functions of the material are enhanced with increasing pressure, particularly in the ultraviolet range, highlighting its suitability for a wide range of optoelectronic devices. Moreover, while maintaining mechanical stability, hydrostatic pressure exerts a significant influence on the mechanical properties of LaLuS3. Lastly, our calculations on anisotropy demonstrate that applied pressure can enhance the anisotropic nature of LaLuS3. This comprehensive study underscores the efficacy of hydrostatic pressure as a systematic approach to modifying the photovoltaic performance of chalcogen perovskites.
Sn-doped β-Ga2O3 thin films grown on off-axis sapphire substrates by LPCVD using Ga-Sn alloy solid source
Authors: Yang Han , Wu Songhao , Ma Chicheng , Liu Zichun , Liu Liwei , Zhang Yiyun , Ma Yuan Xiao , Yi Xiaoyan , Wang Junxi , Wang Yeliang
Published: May 2024

Adopting low pressure chemical vapor deposition (LPCVD), Sn-doped β-Ga2O3 thin films were heteroepitaxially grown on c-plane sapphire substrates with off-axis angles towards 〈11–20〉 direction. The influences of off-axis angle on crystal structures, electrical properties, surface morphology, and chemical compositions were thoroughly investigated. As a result, the crystallinity of the β-Ga2O3 films is improved with increasing off-axis angles because in-plane rotational domains are effectively suppressed, demonstrating a full width at half maximum (FWHM) down to 0.64°. Correspondingly, the Hall carrier mobility is promoted from 4.7 to 17.9 cm2/V·s at carrier concentration of 9 × 1017 cm−3, which is believed highly competitive among reported Sn-doped β-Ga2O3 films by LPCVD. These results demonstrate an alternative pathway to heteroepitaxially grow high electrical quality n-doped β-Ga2O3 films for the advancement of Ga2O3 materials and devices.
Stark broadening of Pd II spectral lines
Authors: Dimitrijević Milan S , Christova Magdalena D
Published: May 2024

Stark widths for 47 spectral lines of singly charged palladium ion (Pd II) have been calculated with the help of the modified semiempirical method. The calculations have been performed for an electron density of 1017 cm−3 and for a temperature range from 5 000 K up to 80 000 K. Employing the obtained results, we investigated the influence of Stark broadening in Pd II spectra of DB and DO white dwarfs as well as A type stars. Moreover, similarities and regularities of Stark widths of Pd II spectral lines within a multiplet, a supermultiplet and a transition array have been discussed.
Exact solutions and bifurcations for the (3+1)-dimensional generalized KdV-ZK equation
Authors: Song Yunjia , Ma Yanzhi , Yang Ben , Wang Zenggui
Published: May 2024

In this paper, a class of (3+1)-dimensional generalized Korteweg–de Vries-Zakharov-Kuznetsov (KdV-ZK) equation is studied by utilizing the bifurcation theory of the planar dynamical systems and the Fan sub-function method. This model can be used to explain the effects of magnetic fields on weakly nonlinear ion-acoustic waves investigated in plasma fields composed of cold and hot electrons. Under the different parameter conditions, the phase portraits and bifurcations are derived, and new exact solutions including soliton, periodic, kink and breaking wave solutions for the model are constructed. Moreover, some exact solutions, which contain soliton, kink, trigonometric function, hyperbolic function, Jacobi elliptic function solutions, are derived via the improved Fan sub-function method. The types of solutions obtained completely correspond to the types of the orbits acquired above, which verifies the validity of the method. Finally, the physical structures of some exact solutions are analyzed in graphical forms.
The preparation and magnetic properties of FeSiCr/MoS2 soft magnetic composites
Authors: Li Nuolin , Feng Shuangjiu , Kan Xucai , Liu Xiansong , Zhang Cong , Zhu Yong , Chi ShangPeng , Sun Wei
Published: May 2024

Two-dimensional layered material MoS2 was used as a high-resistance insulating material and coated on FeSiCr magnetic powder, and FeSiCr/MoS2 composites with low loss and high permeability were successfully prepared. The morphology and magnetic properties of FeSiCr/MoS2 composites were analyzed by XRD, SEM and B-H analyzer. The results show that although the addition of MoS2 will dilute the magnetic properties of FeSiCr, it still has high permeability and obviously reduces the magnetic loss of FeSiCr powder. At the same time, the addition of MoS2 also improves the frequency stability and quality factor of the composite powder cores. Especially, when the MoS2 content is 1.5 wt%, FeSiCr/MoS2 composites show the best magnetic properties after annealing at 500 °C. with a loss of 330 mW cm−3 and permeability of 66.75 (B
m = 20 mT and f = 1000 kHz). It can be seen that the MoS2 coating has a good effect on reducing the magnetic loss of powder core, which significantly improves the possibility of application of SMCs at high frequency.
Highly efficient MIM based SPR sensor for glucose detection using blueP/WS2 layers
Authors: Sarafraz Hadis , Noori Mina
Published: May 2024

In this article, a highly efficient surface plasmon resonance sensor for glucose detection in urine biosamples is presented. The proposed structure with the Ag-Si-Ag configuration was investigated and optimized using the transfer matrix method. In addition, blueP/WS2 and ZnO layers were implemented to further improve the sensitivity of the sensor by light-mater interaction enhancement in the sensing layer. The multilayer configuration of the optimized sensor consists of SiO2 prism /ZnO /Ag1/ Si/Ag2 /ZnO /blueP/WS2 layers, respectively and operates at λ = 633 nm. Different glucose concentrations of 0 to 15 mg dl−1 (for non-diabetic person), 0.625 gm dl−1, 1.25 gm/dL, 2.5 gm/dL, 5 gm/dL, and 10 gm dl−1 (for diabetic body), with refractive indices of 1.335, 1.336, 1.337, 1.338, 1.341, and 1.347, respectively have been regarded and the qualification parameters of S = 320 deg/RIU, FWHM = 1.5767 deg, FOM = 215.99 RIU−1, and minimum reflectance of 0.0318 have been evaluated. We believe that the proposed sensor could pave the way to easy and accurate detection of glucose concentration which is vital in control or treatment of diabetes.
A double take on early and interacting dark energy from JWST
Authors: Forconi Matteo , Giarè William , Mena Olga , Ruchika  , Valentino Eleonora Di , Melchiorri Alessandro , Nunes Rafael C.
Published: May 2024

The very first light captured by the James Webb Space Telescope (JWST) revealed a population of galaxies at very high redshifts more massive than expected in the canonical ΛCDM model of structure formation. Barring, among others, a systematic origin of the issue, in this paper, we test alternative cosmological perturbation histories. We argue that models with a larger matter component Ωmand/or a larger scalar spectral indexnscan substantially improve the fit to JWST measurements. In this regard, phenomenological extensions related to the dark energy sector of the theory are appealing alternatives, with Early Dark Energy emerging as an excellent candidate to explain (at least in part) the unexpected JWST preference for larger stellar mass densities. Conversely, Interacting Dark Energy models, despite producing higher values of matter clustering parameters such asσ8, are generally disfavored by JWST measurements. This is due to the energy-momentum flow from the dark matter to the dark energy sector, implying a smaller matter energy density. Upcoming observations may either strengthen the evidence or falsify some of these appealing phenomenological alternatives to the simplest ΛCDM picture.
CSST Dense Star Field Preparation: A Framework for Astrometry and Photometry for Dense Star Field Images Obtained by the China Space Station Telescope (CSST)
Authors: Wang Yining , Sun Rui , Deng Tianyuan , Zhao Chenghui , Zhao Peixuan , Yang Jiayi , Jia Peng , Liu Huigen , Zhou Jilin
Published: May 2024

The China Space Station Telescope (CSST) is a telescope with 2 m diameter, obtaining images with high quality through wide-field observations. In its first observation cycle, to capture time-domain observation data, the CSST is proposed to observe the Galactic halo across different epochs. These data have significant potential for the study of properties of stars and exoplanets. However, the density of stars in the Galactic center is high, and it is a well-known challenge to perform astrometry and photometry in such a dense star field. This paper presents a deep learning-based framework designed to process dense star field images obtained by the CSST, which includes photometry, astrometry, and classifications of targets according to their light curve periods. With simulated CSST observation data, we demonstrate that this deep learning framework achieves photometry accuracy of 2% and astrometry accuracy of 0.03 pixel for stars with moderate brightness mag = 24 (i band), surpassing results obtained by traditional methods. Additionally, the deep learning based light curve classification algorithm could pick up celestial targets whose magnitude variations are 1.7 times larger than magnitude variations brought by Poisson photon noise. We anticipate that our framework could be effectively used to process dense star field images obtained by the CSST.
Runaway electron plateau current profile reconstruction from synchrotron imaging and Ar-II line polarization angle measurements in DIII-D
Authors: Marini C. , Hollmann E.M. , Tang S.W. , Herfindal J.L. , Shiraki D. , Wilcox R.S. , del-Castillo-Negrete D. , Yang M. , Eidietis N. , Hoppe M.
Published: May 2024

Current profile reconstructions are obtained for high current (

I
p

≃
550

kA) post-disruption runaway electron (RE) plateau plasmas in DIII-D. Two novel methods of measuring the RE current profile in high-current RE plateaus are introduced and compared: localization of the q = 2 rational surface using visible synchrotron emission (SE) imaging and the measurement of the polarization angle of line-integrated Ar-II line emission. The two methods are found to be consistent with each other within the data uncertainties. Different simulations of the RE current profile are compared with the measurements: the toroidal fluid RE model is found to best fit the data, within the measurement uncertainties. In addition to introducing two novel methods to measure the RE current profile and validating present simulation capabilities, this work demonstrates that instabilities can grow at q = 2 and q = 1 surfaces without necessarily causing a RE final loss instability. Numerical simulations are also presented to elucidate the role of these instabilities on synchrotron emission.
Neutron spectroscopy for Boron Neutron Capture Therapy beams characterization
Authors: Monti V. , Costa M. , Durisi E. , Mafucci E. , Calamida A. , Castro Campoy A.I. , Fontanilla A. , Russo L. , Bedogni R.
Published: May 2024

Boron Neutron Capture Therapy (BNCT) is a therapeutic treatment for malignant tumors that utilizes the nuclear reactions that happen when thermal neutrons are captured by boron-10 atoms to selectively destroy designated cells. Boron-10 atoms are biochemically accumulated inside the tumor target, which is then irradiated with thermal neutrons.
In recent years, the possibility to obtain accelerator based intense neutron beams has given a boost to the diffusion of BNCT also in Europe, removing the need of nuclear reactors. In this contest, the monitoring and characterization of the epithermal neutron beams dedicated to BNCT becomes an important issue.
The directional neutron spectrometer called NCT-WES (Neutron Capture Therapy Wide Energy Spectrometer) is a single moderator neutron spectrometer composed of a polyethylene cylinder embedding six semiconductor-based detectors positioned at different depths along the cylinder axes. The position of the six detectors is studied in order to maximize the response of each one in a selected neutron energy range. The unfolding of the six simultaneous readings allows to reconstruct the incoming neutron energy spectrum as in a parallelized Bonner Sphere System. A cylindrical collimator situated in the front of the spectrometer makes the instrument sensitive to neutrons coming only from a given direction, which allows to exclude the contribution of the room scattered radiation. The experimental validation of the spectrometer, obtained through several measuring campaigns, is reported and discussed.
The suitability of various recording methods and devices for registration of seismic signals
Authors: Chilingaryan R.Y. , Khachatryan H.F. , Mkhitaryan S.A. , Hovhannisyan M.A. , Antonyan A.P. , Minasyan A.M. , Drmeyan H.R. , Karapetyan J.K. , Hovhannisyan S.M. , Mkrtchyan A.H.
Published: May 2024

Analytical study and summarization of dynamic and frequency characteristics of the seismic-acoustic vibrations originated by the near and distant earthquakes and other natural and artificial seismic processes, as well as information analyses of their duration and repetition were done. These allow the formulation of appropriate technical requirements for seismic recording devices, as well as to analyze and evaluate the possibilities of implementing various methods and devices for recording signals from different seismic-acoustic processes depending also on the seismological and other tasks to be solved and various additional specific requirements.

It has been shown, that although the introduction of various methods and devices for the digital recording of seismic signals substantially increased during the last decades in seismology, however, it is not even possible to record seismic signals in their entire possible amplitude-frequency ranges employing a single digital recording device too.

It also has been confirmed that the widespread usage of digital recording, transmission, machine processing, and analyzing of seismic signals in most contemporary seismic stations does not reduce the value and does not eliminate the need, but, on the contrary, assumes the conduction of simultaneous analog visible registration of seismic processes to obtain express controlling visible records, provide operational manual express analysis of seismograms.
Compressing of experimental and simulated results of electron beam interaction with FFF-printed samples
Authors: Bushmina E. , Bulavskaya A. , Grigorieva A. , Miloichikova I. , Saburov V. , Stuchebrov S.
Published: May 2024

One of the important parameters characterizing the interaction of electron beams with matter is the depth dose distribution. To develop a new approach for shaping electron beams using specially created materials suitable for the manufacture of complex 3D-printed devices, it is necessary to analyze the features of ionizing radiation propagation. In this work, numerical simulations and experimental studies of the interaction between electron beams and plastic materials weighted with metallic impurities of different concentrations, suitable for fabricating samples using the rapid prototyping method, were carried out. Sets of plates made from the investigated plastics were created using the fused filament fabrication (FFF) technique. Since the FFF sample fabrication process involves forming objects from a thermoplastic mass through layer-by-layer alignment, a distinctive feature of the printed samples is their lower actual density compared to the density of the material (filament) from which they are made. Taking this fact into account, the actual density of the polymer plates was calculated. Based on this data, numerical models of the plastic materials weighted with metallic impurities were developed, and virtual models of the experimental setup were created to calculate the electron beam depth dose distributions in the materials. In the next step of the investigation, experimental studies were performed using electron beams with energies of 6 and 10 MeV. Pre-calibrated GafChromic EBT3 dosimetry films were used as detectors to obtain the experimental data on the electron beam depth dose distributions in the materials under consideration. It was observed that with an increasing concentration of metal impurities in the plastic base, the depth dose distribution moves into smaller thicknesses. It was observed that the simulation and experimental results are in good agreement.
The PMT system of the TRIDENT pathfinder experiment
Authors: Zhang Fuyudi , Hu Fan , Xian Shishen , Tian Wei , Jiang Kun , Li Wenlian , Liu Jianglai , Miao Peng , Sun Zhengyang , Tang Jiannan , Tang Zebo , Wang Mingxin , Wang Yan , Xu Donglian , Ye Ziping
Published: May 2024

Next generation neutrino telescopes are highly anticipated
to boost the development of neutrino astronomy. A
multi-cubic-kilometer neutrino telescope, TRopIcal DEep-sea Neutrino
Telescope (TRIDENT), was proposed to be built in the South China
Sea. The detector aims to achieve ∼ 0.1 degree angular
resolution for track-like events at energy above 100 TeV by using
hybrid digital optical modules, opening new opportunities for
neutrino astronomy. In order to measure the water optical properties
and marine environment of the proposed TRIDENT site, a pathfinder
experiment was conducted, in which a 100-meter-long string
consisting of three optical modules was deployed at a depth of
3420 m to perform in-situ measurements. The central
module emits light by housing LEDs, whereas the other two modules
detect light with two independent and complementary systems: the PMT
and the camera systems. By counting the number of detected photons
and analyzing the photon arrival time distribution, the PMT system
can measure the absorption and scattering lengths of sea water,
which serve as the basic inputs for designing the neutrino
telescope. In this paper, we present the design concept, calibration
and performance of the PMT system in the pathfinder experiment.
Study of the thermal neutron activation of a gamma-ray detector for BNCT dose monitoring
Authors: Colombo G. , Caracciolo A. , Mazzucconi D. , Borghi G. , Carminati M. , Protti N. , Altieri S. , Agosteo S. , Fiorini C.
Published: May 2024

We present a study on the neutron activation of a gamma-ray
detector for a BNCT-SPECT dose imaging system. The detector is based
on a LaBr3(Ce+Sr) scintillator crystal, coupled with a matrix
of Silicon Photomultipliers (SiPMs), read by a dedicated electronics
system. This detector has successfully demonstrated to be capable to
identify the 10B compounds when irradiating borated vials with
thermal neutrons. However, a background signal around 478 keV was
detected, suggesting the activation of the detector itself. This
study aims to determine the origin of this background signal by
simulating the two main parts of the detector, which are the crystal
and electronic boards, in order to assess their contribution to the
background signal. The results of the FLUKA simulations show that
the neutron capture reactions on both the crystal and electronic
boards cause a relevant background nearby the BNCT signal, thereby
limiting the detector's sensitivity. To address this issue, a
customized cadmium shielding has been developed. This solution was
tested at the TRIGA Mark II research nuclear reactor of Pavia
University, where experimental measurements and corresponding FLUKA
simulations proved its effectiveness.
Recognition of EEG-based movement intention combined with channel selection adopting deep learning methods
Authors: Li Jixiang , Wang Zhaoxuan , Li Yurong
Published: May 2024

Brain-computer interface (BCI) is an emerging technology
which provides a road to control communication and external
devices. Electroencephalogram (EEG)-based motor imagery (MI) tasks
recognition has important research significance for stroke,
disability and others in BCI fields. However, enhancing the
classification performance for decoding MI-related EEG signals
presents a significant challenge, primarily due to the variability
across different subjects and the presence of irrelevant
channels. To address this issue, a novel hybrid structure is
developed in this study to classify the MI tasks via deep separable
convolution network (DSCNN) and bidirectional long short-term memory
(BLSTM). First, the collected time-series EEG signals are initially
processed into a matrix grid. Subsequently, data segments formed
using a sliding window strategy are inputted into proposed DSCNN
model for feature extraction (FE) across various dimensions. And,
the spatial-temporal features extracted are then fed into the BLSTM
network, which further refines vital time-series features to
identify five distinct types of MI-related tasks. Ultimately, the
evaluation results of our method demonstrate that the developed
model achieves a 98.09% accuracy rate on the EEGMMIDB physiological
datasets over a 4-second period for MI tasks by adopting full
channels, outperforming other existing studies. Besides, the results
of the five evaluation indexes of Recall, Precision, Test-auc, and
F1-score also achieve 97.76%, 97.98%, 98.63% and 97.86%,
respectively. Moreover, a Gradient-class Activation Mapping
(GRAD-CAM) visualization technique is adopted to select the vital
EEG channels and reduce the irrelevant information. As a result, we
also obtained a satisfying outcome of 94.52% accuracy with 36
channels selected using the Grad-CAM approach. Our study not only
provides an optimal trade-off between recognition rate and number of
channels with half the number of channels reduced, but also it can
also advances practical application research in the field of BCI
rehabilitation medicine, effectively.
Directional detection of keV proton and carbon recoils with MIMAC
Authors: Beaufort C. , Guillaudin O. , Santos D. , Sauzet N. , Mobio E. , Babut R. , Tao C.
Published: May 2024

Directional detection is the dedicated strategy to
demonstrate that DM-like signals measured by direct detectors are
indeed produced by DM particles from the galactic halo. The
experimental challenge of measuring the direction of DM-induced
nuclear recoils with (sub-)millimeter tracks has limited, so far,
the maximal directional reach to DM masses around
100 GeV. In this paper, we expose the MIMAC detector to
three different neutron fields and we develop a method to
reconstruct the direction of the neutron-induced nuclear recoils. We
measure an angular resolution better than 16° for proton
recoils down to a kinetic energy of 4 keV and for carbon
recoils down to a kinetic energy of 5.5 keV. For the
first time, a detector achieves the directional measurement of
proton and carbon recoils with kinetic energies in the keV range
without any restriction on the direction of the incoming
particle. This work demonstrates that directional detection is
around the corner for probing DM with masses down to
 𝒪(1 GeV).
Experimental evaluation of tribo-performances of bump foil journal bearing with different materials of foil
Authors: Mourya Vishal , Bhore Skylab P
Published: May 2024

In this paper, the bump foil journal bearing (FJB) is developed with five different foil materials: Inconel X750 (IN-X750), Stainless steel 316 (SS316), Beryllium copper (BC), Spring steel EN42J (SP EN42J) and Phosphor bronze (PB). A complete fabrication process is described in detail, along with the design of fixtures, to develop the bump FJB. This fabrication process includes various machining operations such as milling, rolling, cutting, threading, forming etc. The forming load versus deflection curve is obtained for all the foil materials with the metal forming operation. After fabricating it, the load-deflection test is performed to evaluate the structural characteristics (stiffness, energy dissipation and damping coefficient) of these developed bump FJB. Further, the tribological characteristics of bump FJB such as wear rate and surface roughness are evaluated by the experimental study. Moreover, the interface temperature of bump FJB is also captured by using the thermal imager. This study shows that the metal forming operation is the most challenging step among all the fabrication steps of bump FJB Among all the foil materials, the minimum wear rate and maximum surface roughness of bump FJB are observed for the IN-X750. The maximum spring-back effect in bump FJB is found for the Spring steel EN42J. These results demonstrate that the maximum energy dissipation and stiffness of bump FJB are observed for the Phosphor bronze and Inconel-X750 respectively. In addition, the damping coeffcient of bump FJB is evaluated.
Influence of different manufacturing techniques on GFRP flat-joggle-flat composite joints using multi-scale reinforcements for enhancing shear properties
Authors: Hiremath Vinayak S , Dhilipkumar Thulasidhas , Reddy D Mallikarjuna , Mutra Rajasekhara Reddy , Rajesh Murugan
Published: May 2024

Composite materials, particularly glass fibre-reinforced polymers, or GFRP are being used far more frequently. Airframes have been manufactured utilizing reinforced composites, including struts, frames, and flaps, employing raised epoxy-based co-cure technology. The current research describes a multi-scale approach to fortifying graphene nanoparticles (GNP) and carbon fibre Z-pins in order to strengthen the flat-joggle-flat composite joints with different manufacturing technique. Shear investigation showed that by adding GNPs and putting carbon fibre pins (Z-pins) in a crosswise position (perpendicular to the plane) to the joint's surface, concurrent reinforcement gives rise to greater shear characteristics with quasi-static loads. Specifically, there was a 45.6% improvement in shear resistance when contrasted with unreinforced co-cured FJF joints. The FESEM has been utilized to demonstrate the failure analysis of the specimens, which shows the clear failure mechanism of the FJF joint specimens. The FJF joint with multiscale reinforcement has a very high natural frequency of 685.1 Hz as compared to other configurations, according to the vibration analysis.
Firing salts method for the synthesis of orthorhombic Gd2TiO5: experimental characterization supported by DFT first principles calculations
Authors: Quintana-García M , León-Flores J , Pérez-Mazariego J L , Arenas-Alatorre J , Marquina M L
Published: May 2024

This work presents the synthesis by the new ‘firing salts method’ (FSM) of orthorhombic Gd
2
TiO
5 which requires only two hours at 1200 °C. X Ray Diffraction, High Resolution Transmission Electron Microscopy, Fourier Transform Infrared Spectroscopy and Raman spectroscopy characterized it. Electron microscopy shows particle size distribution between 50–500 nm with orthorhombic structure according to Rietveld analysis. Raman—infrared spectroscopies and first principles calculations indicate that the second order contribution to the spectra comes from the Ti-O5 interactions. First principles calculations (Density Functional Theory) were used as an aid for the interpretation of the experimental results to assign the normal modes to the bands on the Raman and IR spectra; it also provided an insight of the chemical reactivity of the synthesis.
Photoelectric synapses based on all-two-dimensional ferroelectric semiconductor heterojunction
Authors: Zhao Xuanyan
Published: May 2024

Photoelectric synapses are attracting intensive attention due to its low power consumption and adaptive learning. However, traditional ferroelectric field effect transistors are not conducive to the integrated application in artificial intelligence systems. Here, we design the all two-dimensional photoelectric synapse device based on WSe2/MoS2/α-In2Se3 ferroelectric van der Waals heterojunction, which has high memory capacity (memory on/off = 105) and synaptic function. In addition, we simulate an artificial neural network to modify the handwritten digit recognition of the National Institute of Standards and Technology. In particular, the recognition rates are 92.4% and 93.6% for electrical synapse and photoelectric synapse, respectively. This work provides an effective strategy for achieving stable integration of neuromorphic computing.
Assessment of impacts of flood and coping strategies among rural households in Gicumbi district, Rwanda
Authors: Uwayisenga Ange Josiane , Adelekan Ibidun , Oguge Nicholas
Published: May 2024

Floods have become recurrent events in Rwanda, causing diverse effects on rural households across the country. However, little is known about the effects of floods encountered by people and their coping strategies, which are crucial for reducing vulnerability. Gicumbi District is among the most exposed to climate hazards and is vulnerable to the impacts of climate change. The effects of floods on rural households in Gicumbi district and their coping strategies were examined. A mixed approach was adopted where quantitative data was collected to inform wider understanding of a population and qualitative ones to acquire deep contextual insights about individual’s lived experiences. A structured questionnaire was used to collect data from 399 heads of households stratified into six district sectors. The study employed descriptive and inferential statistics for data analysis. Common effects of flooding experienced by the respondents included crop destruction, house damage, lack of sufficient food and safe drinking water. The coping strategies adopted by the respondents included saving money and food, support from friends and families, selling assets, borrowing money to restore losses, and migrating to other communities. In addition, flood victims received support from local authorities and Non-Governmental Organizations (NGOs), including financial support, temporary shelters, and life support materials. Adaptation strategies adopted by households included drainage channels, plantation of trees, radical terraces and sandbags. The results showed that lack of flood risk knowledge and access to early warnings, inadequate housing, living in high-risk areas, and dependence on a single source of income were the main factors influencing the severity of flood effects. Early warnings (p < 0.001) and flood risk awareness (p = 0.009) significantly elicited positive coping mechanisms. Governments and relevant stakeholders should develop effective strategies and establish programs enabling timely access to early warning systems and increasing disaster risk awareness to reduce vulnerability for improved livelihoods and community resilience.
Transformer-powered surrogates close the ICF simulation-experiment gap with extremely limited data
Authors: Olson Matthew L , Liu Shusen , Thiagarajan Jayaraman J , Kustowski Bogdan , Wong Weng-Keen , Anirudh Rushil
Published: May 2024

Recent advances in machine learning, specifically transformer architecture, have led to significant advancements in commercial domains. These powerful models have demonstrated superior capability to learn complex relationships and often generalize better to new data and problems. This paper presents a novel transformer-powered approach for enhancing prediction accuracy in multi-modal output scenarios, where sparse experimental data is supplemented with simulation data. The proposed approach integrates transformer-based architecture with a novel graph-based hyper-parameter optimization technique. The resulting system not only effectively reduces simulation bias, but also achieves superior prediction accuracy compared to the prior method. We demonstrate the efficacy of our approach on inertial confinement fusion experiments, where only 10 shots of real-world data are available, as well as synthetic versions of these experiments.
A European Elizabethan
Authors: Gehring David Scott
Published: May 2024

This book brings Robert Beale, a man usually in the background and shadows of Elizabethan England, into the light. By situating him in his European contexts of education, travel, religion, and politics, it illuminates the ways in which Beale’s experiences in the Holy Roman Empire and France prepared him for a career in the engine room of Elizabethan government. A man of modest origins, he enjoyed the patronage, protection, and friendship of some of Queen Elizabeth’s top officials like William Cecil and Francis Walsingham, but he was also personally insecure and financially vulnerable. Beale’s own religious inclinations, political principles, legal positions, and personal life all come into full colour here, as do the ways in which Beale engaged with many large and overlapping issues in Elizabethan politics and religion, like the royal succession, Puritanism, international relations, and the wars of religion. By thoroughly investigating Beale’s personal reference archive, which remains largely intact at the British Library, and additional material across the UK, mainland Europe, and the USA, this book endeavours to mirror Beale’s own archival practices in collation, reading, reflecting, and writing that made him simultaneously a jack-of-all trades and a master of them all. By considering a man with identities and experiences both particularly English and broadly European, the book offers a route forward for thinking about Europe was in England, and England was in Europe.
Europe in England
Authors: Gehring David Scott
Published: May 2024

The introductory chapter situates the challenge of writing a biography in the immediate context of Robert Beale’s life and relevant papers. It addresses how historians, such as Patrick Collinson and Mark Taviner, have viewed Beale in different ways, from his own age to the present, often in compartmentalized or partial ways. In addition, the chapter offers a broad outline for the book and discusses various historiographical issues. Of special note are the scholarly attention paid to international connections between England and mainland Europe in the sixteenth century, the state paper office, and renewed interest in diplomacy and governance. Overall, the chapter suggests the merits of seeing aspects of broader European history and culture in sixteenth-century England.