bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a novel multi-constriction superconducting magnetic flux concentrator and its application in magnetoresistance-superconducting composite magnetic sensors
Authors: Han Siyuan , Wu Yue , Xiao Liye , Jin Zhenhu , Chen Jiamin 
Published: January 2025

Abstract
Magnetoresistance-superconducting composite magnetic sensors, as highly sensitive weak magnetic sensors, have broad application prospects in fields such as magnetocardiography, magnetoencephalography, and high-precision non-destructive testing. Among these, the magnetic field gain of the superconducting magnetic flux concentrator (MFC) is a key factor affecting the magnetic field resolution of magnetoresistance-superconducting composite magnetic sensors. However, current superconducting MFCs face the issue of saturation in magnetic field amplification performance. This paper proposes a novel superconducting MFC structure that enhances the magnetic field gain of the superconducting MFC by adopting a multilayer stacked structure of constrictions. Finite element simulations reveal the impact of different constriction stacking structure parameters on the magnetic field amplification capability. Based on this, a TMR-superconducting multi-constriction composite magnetic sensor with a double-layer constriction stacked structure was prepared. Compared to conventional TMR-superconducting composite magnetic sensors, the magnetic field sensitivity increased by more than 1.7 times. This superconducting MFC realizes a magnetic field gain of nearly 350 in a small volume, which boosts the magnetic field detection performance of traditional TMR from nT level to pT level at low frequencies. The research presented in this paper contributes to the development of high-sensitivity magnetoresistive sensors.
Optimisation and loss analyses of pulsed field magnetisation in a superconducting motor with cryocooled iron cores
Authors: Wang Qi , Hao Luning , Zhang Hongye , Wei Haigening , Sun Guojin , Huang Zhipeng , Wu Yuyang , Hu Jintao , Coombs Tim 
Published: January 2025

Abstract
Thanks to their compact size, reduced energy losses, and enhanced power density, superconducting motors utilising high-temperature superconducting (HTS) materials are particularly appealing for propulsion systems such as those used in electric aircraft. Upon magnetisation, stacked HTS coated conductors are transformed into trapped field stacks (TFSs), which represent a key variant of trapped field magnets. TFSs offer a promising alternative to traditional permanent magnets, providing rotor fields for motor operation, particularly in synchronous machines. To date, there has been a lack of comprehensive investigation into the interaction between HTS TFSs and cryocooled iron cores, as well as the losses generated in iron cores during pulsed field magnetisation (PFM). Furthermore, the optimal magnetisation strategy for achieving the maximum trapped field in TFSs through PFM for motor applications remains an unresolved issue. To address these challenges, a 2D electromagnetic-thermal coupled numerical model was built using the finite element method and validated against experimental data. This model was employed to analyse a superconducting machine featuring TFSs as rotor magnets and cryocooled iron cores. This study introduces two key novelties. The primary novelty lies in identifying the optimal combination of pulsed current amplitudes and TFS layer numbers required to achieve maximum magnetisation fields. The secondary novelty involves evaluating the overall losses in both superconducting and non-superconducting components of the machine during PFM. This includes heat generation in various layers of the TFS and losses in the motor’s active materials, such as copper windings and iron cores. Additionally, two practical motor configurations were proposed, and two calculation methods using linear interpolation of iron losses and steel grades were introduced to estimate the iron losses for the studied iron material, M270-35 A. This pioneering study is expected to serve as a valuable reference for loss analyses and structural design considerations in developing superconducting machines.
Enhancing primordial B-mode detection: comprehensive delensing pipelines for improved sensitivity to r
Authors: Chen Wen-Zheng , Liu Yang , Li Siyu , Hu Bin , Li Hong 
Published: January 2025

Abstract
Recognizing the impact of contamination from weak gravitational lensing B-modes induced by
Large Scale Structure, we examine delensing methods to enhance sensitivity to the tensor-to-scalar
ratio r in primordial B-mode detection experiments. This study presents a realistic pipeline to
improve r constraints using foreground-cleaned maps with negligible residuals. The pipeline,
based on simulations, is adaptable for future experiments. We focus on two delensing approaches:
(1) subtracting the gradient-order lensing B-mode template, computed by convolving the E-mode with
the lensing potential, from the observed B-mode signal; and (2) remapping observations using the
estimated inverse deflection angle. For parameter constraints, we employ three models to reduce
r uncertainty and bias, finding consistent uncertainties across models, though biases vary due
to the multipole-dependence of the delensing fraction. We demonstrated this pipeline using
simulated observation maps from future CMB polarization experiments, which included current
representative ground-based small aperture telescopes (sub-1m), next-generation ground-based large
aperture telescopes (6m), and highly competitive future space-based medium aperture
missions (3m). Results show a delensing efficiency of 40% with the small-aperture telescope
alone, increasing to 65% when combined with the large-aperture telescope, and 80% with the
satellite mission. These lead to reductions in r uncertainty by 46% for ground-based and 63%
for space missions. The most promising method adds the lensing template B-mode as an additional
frequency channel, minimizing bias on r.
Unveiling galaxy pair alignment in cosmic filaments: A 3D exploration using EAGLE simulation
Authors: Sarkar Suman , Pandey Biswajit 
Published: January 2025

Abstract
We investigate how galaxy pairs are oriented in three dimensions within cosmic filaments
using data from the EAGLE simulation. We identify filament spines using DisPerSE and isolate
galaxies residing in filamentary environments. Employing a FoF algorithm, we delineate individual
filaments and determine their axes by diagonalizing the moment of inertia tensor. The orientations
of galaxy pairs relative to the axis of their host filament are analyzed. Our study covers diverse
subsets of filaments identified through varying linking lengths, examining how galaxy pairs align
with the filament axis across different spatial parameters such as pair separation and distance
from the filament spine. We observe a nearly uniform probability distribution for the cosine of
the orientation angle, which is nearly identical in each case. We also investigate the effects of
redshift space distortions and confirm that the probability distributions remain uniform in both
real space and redshift space. To validate our approach, we conduct Monte Carlo simulations using
various theoretical probability distributions. Our analysis does not reveal any evidence of
preferential alignment of galaxy pairs within cosmic filaments in hydrodynamical simulations.
New shape for cross-bispectra in Chern-Simons gravity
Authors: Christodoulidis Perseas , Gong Jinn-Ouk , Lin Wei-Chen , Mylova Maria , Sasaki Misao 
Published: January 2025

Abstract
Chern-Simons gravity is known to suffer from graviton ghost production during inflation, which suppresses the parity-violating power spectrum at scales relevant to cosmic microwave background observations. In this work, we show that allowing the initial conditions of inflation to deviate from the standard Bunch-Davies state can enhance parity-violating non-Gaussianity in the scalar-tensor cross-bispectra. Our results reveal a significant additional contribution to the cross-bispectra in the flattened configuration, offering a new avenue to constrain parity-violating gravity.
STIPS algorithm enables tracking labyrinthine patterns and reveals distinct rhythmic dynamics of actin microridges
Authors: Bhavna Rajasekaran , Sonawane Mahendra 
Published: January 2025

Abstract
Tracking and motion analyses of semi-flexible biopolymer networks from time-lapse microscopy images are important tools that enable quantitative measurements to unravel the dynamic and mechanical properties of biopolymers in living tissues, crucial for understanding their organization and function. Biopolymer networks are challenging to track due to continuous stochastic transitions, such as merges and splits, which cause local neighborhood rearrangements over short time and length scales. To address this, we propose the Spatio Temporal Information on Pixel Subsets algorithm to track these events by creating pixel subsets that link trajectories across frames. Using this method, we analyzed actin-enriched protrusions, or ‘microridges,’ which form dynamic labyrinthine patterns on squamous cell epithelial surfaces, mimicking ‘active Turing-patterns.’ Our results reveal two distinct actomyosin-based rhythmic dynamics in neighboring cells: a common pulsatile mechanism between 2 and 6.25 min period governing both fusion and fission events contributing to pattern maintenance, and cell area pulses predominantly exhibiting 10 min period.
Evaluation of objective methods for analyzing ipsilateral motor evoked potentials in stroke survivors with chronic upper extremity motor impairment
Authors: Mohan Akhil , Li Xin , Zhang Bei , Knutson Jayme S , Widina Morgan , Wang Xiaofeng , Uchino Ken , Plow Ela B , Cunningham David A 
Published: January 2025

Abstract

Objective:Ipsilateral motor evoked potentials (iMEPs) are believed to represent cortically evoked excitability of uncrossed brainstem-mediated pathways. In the event of extensive injury to (crossed) corticospinal pathways, which can occur following a stroke, uncrossed ipsilateral pathways may serve as an alternate resource to support the recovery of the paretic limb. However, iMEPs, even in neurally intact people, can be small, infrequent, and noisy, so discerning them in stroke survivors is very challenging. This study aimed to investigate the inter-rater reliability of iMEP features (presence/absence, amplitude, area, onset, and offset) to evaluate the reliability of existing methods for objectively analyzing iMEPs in stroke survivors with chronic upper extremity motor impairment.&#xD;Approach: Two investigators subjectively measured iMEP features from thirty-two stroke participants with chronic upper extremity motor impairment. Six objective methods based on standard deviation (SD) and mean consecutive differences (MCD) were used to measure the iMEP features from the same 32 participants. IMEP analysis used both trial-by-trial (individual signal) and average-signal analysis approaches. Inter-rater reliability of iMEP features and agreement between the subjective and objective methods were analyzed (percent agreement-PA and intraclass correlation coefficient-ICC).&#xD;Main results: Inter-rater reliability was excellent for iMEP detection (PA> 85%), amplitude, and area (ICC> 0.9). Of the six objective methods we tested, the 1SD method was most appropriate for identifying and analyzing iMEP amplitude and area (ICC> 0.9) in both trial-by-trial and average signal analysis approaches. None of the objective methods were reliable for analyzing iMEP onset and offset. Results also support using the average-signal analysis approach over the trial-by-trial analysis approach, as it offers excellent reliability for iMEP analysis in stroke survivors with chronic upper extremity motor impairment.&#xD;Significance: Findings from our study have relevance for understanding the role of ipsilateral pathways that typically survive unilateral severe white matter injury in people with stroke.&#xD;
Long-term performance and stability of implanted neural interfaces in individuals with lower limb loss
Authors: Petros Eileen , Miller Michael , Dunning Jeremy , Pinault Gilles , Tyler Dustin , Triolo Ronald , Charkhkar Hamid 
Published: January 2025

Abstract

Objective. High-density nerve cuffs have been successfully utilized to restore somatosensation in individuals with lower-limb loss by interfacing directly with the peripheral nervous system. Elicited sensations via these devices have improved various functional outcomes, including standing balance, walking symmetry, and navigating complex terrains. Deploying neural interfaces in the lower limbs of individuals with limb loss presents unique challenges, particularly due to repetitive muscle contractions and the natural range of motion in the knee and hip joints for transtibial and transfemoral amputees, respectively. This study characterizes the long-term performance of these peripheral nerve interfaces, which is crucial for informing design modifications to optimize functionality. Approach. We evaluated the longitudinal performance of 16-contact nerve cuffs and their associated components implanted in four participants with unilateral transtibial limb loss over five years. Key outcome measures included charge density at sensory thresholds and electrical impedance. Main results. Out of 158 channels (i.e. individual contacts within the nerve cuffs and their corresponding leads), 63% were consistently responsive, 33% were partially responsive, and 4% were non-responsive. Smaller connector assemblies and increased lead length near the cuffs significantly enhanced performance, with the final two participants demonstrating notably improved responses where 77% and 96% of channels were consistently responsive, respectively, compared to 50% and 6% in the first two participants. Significance. Overall, the implanted nerve cuffs showed robust stability in the residual limbs of highly active individuals with limb loss. Furthermore, employing strategies to reduce stress on transition points in the components significantly improved overall system performance.
Global stellarator coil optimization with quadratic constraints and objectives
Authors: Fu Lanke , Paul Elizabeth J. , Kaptanoglu Alan A. , Bhattacharjee Amitava 
Published: January 2025

Abstract
Most present stellarator designs are produced by costly two-stage optimization: the first for an optimized equilibrium, and the second for a coil design reproducing its magnetic configuration. Few proxies for coil complexity and forces exist at the equilibrium stage. Rapid initial state finding for both stages is a topic of active research. Most present convex coil optimization codes use the least square winding surface method by Merkel (NESCOIL), with recent improvements in conditioning, regularization, sparsity, and physics objectives. While elegant, the method is limited to modeling the norms of linear functions in coil current. We present QUADCOIL, a global coil optimization method that targets combinations of linear and quadratic functions of the current. It can directly constrain and/or minimize a wide range of physics objectives unavailable in NESCOIL and REGCOIL, including the Lorentz force, magnetic energy, curvature, field-current alignment, and the maximum density of a dipole array. QUADCOIL requires no initial guess and runs nearly

10
2

×

faster than filament optimization. Integrating it in the equilibrium optimization stage can potentially exclude equilibria with difficult-to-design coils, without significantly increasing the computation time per iteration. QUADCOIL finds the exact, global minimum in a large parameter space when possible, and otherwise finds a well-performing approximate global minimum. It supports most regularization techniques developed for NESCOIL and REGCOIL. We demonstrate QUADCOIL’s effectiveness in coil topology control, minimizing non-convex penalties, and predicting filament coil complexity with three numerical examples.
Generalized diffusive epidemic process with permanent immunity in two dimensions
Authors: Carvalho V R , Alves T F A , Alves G A , Alencar D S M , Lima F W S , Macedo-Filho A , Ferreira R S 
Published: January 2025

Abstract
We introduce the generalized diffusive epidemic process, which is a metapopulation model for an epidemic outbreak where a non-sedentary population of walkers can jump along lattice edges with diffusion probabilities

D

S

or

D

I

if they are susceptible or infected, respectively, and recovered individuals possess permanent immunity. Individuals can be contaminated with probability

μ

c

if they share the same lattice node with at least one infected individual and recover with probability

μ

r

, being removed from the dynamics. Therefore, the model does not have the conservation of the active particles composed of susceptible and infected individuals. The reaction-diffusion dynamics are separated into two stages: (i) Brownian diffusion, where the particles can jump to the neighboring nodes, and (ii) contamination and recovery reactions. The dynamics are mapped into a growing process by activating lattice nodes with successful contaminations where activated nodes are interpreted as infection sources. In all simulations, the epidemic starts with one infected individual in a lattice filled with susceptibles. Our results indicate a phase transition in the dynamical percolation universality class controlled by the population size, irrespective of diffusion probabilities

D

S

and

D

I

and a subexponential (power-law) growth of the epidemics in the percolation threshold.
Assessing the dosimetric effects of high-Z titanium implants in proton therapy using pixel detectors
Authors: Bălan C. , Granja C. , Mytsin G. , Shvidky S. , Molokanov A. , Chiș V. , Oancea C. 
Published: January 2025

Abstract
A rapid increase in the use of proton therapy for cancer treatment has been seen in the last decade due to its clinical advantages. Therefore, more and more patients with implants and other metallic devices will be among those who will be treated. This study experimentally examines the effect and changes in the delivered fields, using water-equivalent phantoms with and without titanium (Ti) dental implants positioned along the primary beam path. We measured in detail the composition and spectral-tracking characterization of particles generated in the plateau region of the Bragg curve towards the Sub-peak region using high-spatial resolution, spectral and time-sensitive imaging detectors with a pixelated array provided by the ASIC chip Timepix3. A 170 MeV proton beam was collimated and modulated in a polymethyl methacrylate (PMMA) block. Placing two dental implants behind the PMMA block, the radiation was measured using two pixeled detectors with silicon (Si) sensors. The Timepix3 (TPX3) detectors measured in detail particle fluxes, dose rates (DR) and linear energy transfer (LET) spectra for resolved particle types. Artificial intelligence (AI) based-trained neural networks (NN) calibrated in well-defined radiation fields were used to analyze and identify particles based on morphology and characteristic spectral-tracking response. The beam was characterized and single-particle tracks were registered and decomposed into particle-type groups. The resulting particle fluxes in both setups are resolved into three main classes of particles: i) protons, ii) electrons and photons, and iii) ions. Protons are the main particle component responsible for dose deposition. High-energy transfer particles (HETP), namely ions exhibited differences in both dosimetric aspects that were investigated: DR and particle fluxes, when the Ti implants were placed in the setup. The detailed multi-parametric information of the secondary radiation field provides a comprehensive understanding of the impact of Ti materials in proton therapy.
Numerical simulation and optimization of discharge chamber miniaturization for the double hollow cathode sputtering type metal ion source
Authors: Zhu Tingru , Wang Jinghui , Fu Dongpo , Zhao Weijiang , Cai Shixian , Zhang Caijie , Zhu Kun 
Published: January 2025

Abstract
The double hollow cathode metal ion source produces metal
elements by hollow cathode sputtering and has a high material
utilization rate. However, at present, a high magnetic mirror field
is generated by an electromagnet, which is huge in volume and the
edge field of a high magnetic mirror field seriously affects ion
extraction. Miniaturization of the discharge chamber is a feasible
method to solve this problem. In this paper, a two-dimensional fluid
model of the double hollow cathode discharge structure under
magnetic mirror field constraints is developed to study the double
hollow cathode discharge and ion sputtering. The results show that
the sputtering depth flux is formed above the sputtering voltage of
400 V. The evolution of the sputtering depth profile results from
the combined effect of the wall ion flux, spatial radial electric
field, and ion collisions. The location of the maximum ion
sputtering depth depends mainly on the energetic ions entering the
hollow cathode from the anode. The magnetic field and thermal
electron emission strongly correlate with the sputtering depth. A
small discharge chamber structure is proposed with a hollow cathode
length of 36 mm, which is 24 mm smaller than the ion source
established by Peking University in 2017, using a magnetic mirror
field of 1400 Gs at the center point, which can be realized in the
form of a permanent magnet. The electron density in the center of
the discharge chamber is 2.88 × 1021 m-3 and 99% of
the electrons are confined within a radius of about 3.7 mm.
MEOP based 3He polarization and injection system for experiments below 1 K
Authors: Rao T. , Barrón-Palos L. , Berkutov I. , Crawford C.B. , Golub R. , Huffman P. , Konieczny M. , Korobkina E. , Reid Austin , Salazar-Ángeles B. , Smith C. , Tat R. , Zanatta-Martínez T. 
Published: January 2025

Abstract
Metastability exchange optical pumping (MEOP) is a widely
used technique for producing polarized 3He. In connection with
an experiment to search for the electric dipole moment of the
neutron (nEDM) we have built a MEOP based 3He polarization and
injection system to prepare 80 % polarized 3He at room
temperature which will be injected into a ∼ 400 mK measurement
cell filled with superfluid 4He. We describe the polarization
and injection system, which is designed to allow for final
concentrations of 10-8–10-10 of 80% polarized 3He
in the superfluid filled measurement cell. Only ≈ 0.72%
polarization loss due to gradients is expected during injection
The CuboDAQ data acquisition system
Authors: Zaffaroni E. , Haefeli G. 
Published: January 2025

Abstract
CuboDAQ is a custom data acquisition system to read out
SiPM-based detectors. It features electronic boards to digitize the
SiPMs signal, an FPGA-based system-on-module board, the connectivity
to transmit the data to a central server, and all the software
necessary to operate them. The front-end is based on the TOFPET2
ASIC, produced by PETsys, connected to a custom board, featuring an
Enclustra Mercury SA1 module with a Cyclone V FPGA. Multiple boards
can be operated synchronously by distributing the clock and
synchronous reset signals from a central source. The system
features a complete software framework to calibrate and monitor the
detectors, to acquire and process data and to perform track
reconstruction. The CuboDAQ system performance has been evaluated
in different scenarios and can cope with sustained rates of above
4·106 hits/s, with
peaks of more than
7·106 hits/s. This
system has been employed for the readout of the SND@LHC detector at
CERN, a testbeam telescope and lab setups.