bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic resonance cavitation imaging for the monitoring of ultrasound therapies
Authors: Ishak Ounay , Breton Elodie , Cabras Paolo , Dumont Erik , Mondou Paul , Novell Anthony , Larrat Benoît , Vappou Jonathan 
Published: October 2024

Abstract

Objective. Focused ultrasound (FUS) is a promising non-invasive therapeutic approach that can be used to generate thermal and non-thermal bioeffects. Several non-thermal FUS therapies rely on FUS-induced oscillations of microbubbles (MBs), a phenomenon referred to as cavitation. Cavitation monitoring in real time is essential to ensure both the efficacy and the safety of FUS therapies. This study aims to introduce a new magnetic resonance (MR) method for cavitation monitoring during FUS therapies. Approach. By finely synchronizing the FUS pulse with an accelerated turbo spin-echo MR sequence, the cavitation effect could be quantitatively estimated on the acquired images at 1-Hz refresh rate. The proposed method was assessed in vitro in a water bath. A series of FUS pulses were generated on a silicone tube filled with MBs at different acoustic pressures (0.07–2.07 MPa) and pulse durations (20–2000 μs). MR images and passive cavitation detection (PCD) signals were simultaneously acquired for each FUS pulse. Main results. Inertial cavitation was found to induce a quantitatively interpretable signal loss on the MR image. The transition from stable to inertial cavitation was identified on MR cavitation maps with high repeatability. These results were found to be in good agreement with PCD measurements in terms of pressure thresholds between stable and inertial cavitation. MR cavitation imaging was shown to be sensitive to short and even ultrashort FUS pulses, from 2 ms down to 20 μs. The presented theoretical model suggests that the signal loss in MR cavitation imaging relies on susceptibility changes related to the diameter of the oscillating MBs. Significance. The proposed MR cavitation imaging method can both locate and characterize cavitation activity. It has therefore the potential to improve the efficacy and safety of FUS therapies, particularly for localized drug delivery applications.
The dosimetric accuracy of a commercial model-based dose calculation algorithm in modeling a six-groove direction modulated brachytherapy tandem applicator
Authors: Meftahi Moeen , Song William Y 
Published: October 2024

Abstract

Objective. With advancements in high-dose rate brachytherapy, the clinical translation of intensity modulated brachytherapy (IMBT) innovations necessitates utilization of model-based dose calculation algorithms (MBDCA) for accurate and rapid dose calculations. This study uniquely benchmarks a commercial MBDCA, BrachyVision ACUROSTM (BVA), against Monte Carlo (MC) simulations, evaluating dose distributions for a novel IMBT applicator, termed as the six-groove Direction Modulated Brachytherapy (DMBT) tandem, expanding beyond previous focus on partially shielded vaginal cylinder applicators, through a novel methodology. Approach. The DMBT tandem applicator, made of a tungsten alloy with six evenly spaced grooves, was simulated using the GEANT4 MC code. Subsequently, two main scenarios were created using the BVA and reproduced by the MC simulations: ‘Source at the Center of the Water Phantom (SACWP)’ and ‘Source at the Middle of the Applicator (SAMA)’ for three cubical virtual water phantoms (20 cm)3, (30 cm)3, and (40 cm)3. A track length estimator was utilized for dose calculation and 2D/3D scoring were performed. The difference in isodose surfaces/lines (i.e. coverage) at each voxel, ΔD
Isodose Levels/Lines, was thus calculated for relevant normalization points (r
ref). Results. The coverage was comparable, based on 2D scoring, between the BVA and MC isodose surfaces/lines for the region of clinical relevance, (i.e. within 5 cm radius from the source) with ΔD
Isodose Lines (r
ref: 1 cm from the source) falling within 2% for the two scenarios for all phantom sizes. For the phantom (20 cm)3, ΔD
Isodose Levels (3D scoring) recorded the range [−3.0% +6.5%] ([−7.4% +7.3%]) for 95% of the voxels of the same scoring volume for the SACWP (SAMA) scenario. Significance. The results indicated that the BVA could render comparable coverage as compared to the MC simulations in the region of clinical relevance for different phantom sizes. ΔD
Isodose Lines may offer an advantageous metric for evaluation of MBDCAs in clinical setting.
The influence of equilibrium points and initial values on multistability of a multi-scroll chaotic system and predefined-time synchronization
Authors: Yan Shaohui , Zhang Yunhe , Zhang Hanbing 
Published: October 2024

Abstract
In order to explore the effect of the initial value on the symmetry of the coexisting attractor, a novel multi-scroll chaotic system is designed in this paper. The system is proved to be chaotic by analysing the phase diagram, Lyapunov exponential spectrum and dissipativity of the system. Then the equilibrium point of the system is investigated and it is found that the system has four symmetric saddle focus of index 2. By analysing the dynamical behaviour of the system, it is found that the system has a special kind of multistability. Combining the properties of the orbits near the saddle focus of indicator 2, the reason for this special multistability is explained, and the effect of the positional relationship between the initial value and the saddle focus on the symmetry of the coexisting attractors is illustrated, which provides a new way of thinking to analyse the symmetric coexistence of chaotic systems. In order to verify the feasibility and application value of the system, simulation circuits are designed and predefined-time synchronization between systems of different dimensions is achieved.
Design of a robust intelligent controller based neural network for trajectory tracking of high-speed wheeled robots
Authors: Xue Wenkui , Zhou Baozhi , Chen Fenghua , Ghaderpour Ebrahim , Mohammadzadeh Ardashir 
Published: October 2024

Abstract
The control design of wheeled mobile robots is often accomplished based on the robot’s kinematics which imposes critical challenges in the motion tracking control of such systems. In the related literature, most works designed dynamic controllers based on the terms of voltage or torque; however, the velocity is often utilized in industrial and commercial applications. To address this issue, this paper focuses on the design of a velocity-based control for the trajectory-tracking problem of mobile robots in practical applications including measurement acquisition. The control design of the mobile robot is realized in two separate parts using kinematic control and dynamic control. The design of kinematic control is carried out based on the robot’s kinematics where the motion is described without considering the forces and torques. A radial basis function (RBF) neural network (NN) based on the model-free controller is designed for the dynamic controller of mobile robots without relying on the system dynamics. In the proposed dynamic control, a time-delay estimation is adopted to estimate the disturbances and noises in the mobile robot and remove them from the feedback loop control. Several typical scenarios of mobile robots with high-speed movements are conducted to assess the feasibility of the proposed NN controller-based time-delay estimation under noises and disturbances. To show the supremacy of the suggested controller, the dynamic responses of the mobile robot test system are compared with the prevalent controllers. The extensive simulation and real-time examinations reveal the capability of the proposed NN controller-based time-delay estimation to control high-speed mobile robots under high-level noises and disturbances.
Topological 4D gravity and gravitational defects
Authors: Boujakhrout Y , Sammani R , Saidi E H 
Published: October 2024

Abstract
Using the Chern-Simons formulation of AdS3 gravity as well as the Costello-Witten-Yamazaki (CWY) theory for quantum integrability, we construct a novel topological 4D gravity given by equation (5.1) with observables based on gravitational gauge field holonomies. The field action

S

4
D

grav

of this gravity has a gauge symmetry

SL
(
2
,
C
)

and reads also as the difference

S

4
D

CWY

L

−

S

4
D

CWY

R

with 4D Chern-Simons field actions

S

4
D

CWY

L

/

R

given by left/right CWY theory equation (3.9). We also use this 4D gravity derivation to build observables describing gravitational topological defects and their interactions. We conclude our study with few comments regarding quantum integrability and the extension of AdS3/CFT2 correspondence with regard to the obtained topological 4D gravity.
DFT study of electronic and nonlinear optical properties of alkaline earth metals and superalkalis doped all-cis-1, 2, 3, 4, 5, 6-hexafluorocyclohexane as an efficient excess electron system
Authors: Sohaib Muhammad , Maqbool Maria , Ayub Khurshid 
Published: October 2024

Abstract
Continual advancements are being pursued to discover innovative strategies for developing materials with remarkable nonlinear optical (NLO) response. Herein, electronic, geometric, thermodynamic and NLO properties of excess electron systems based on stacked Janus dimer, all-cis-1,2,3,4,5,6-hexafluorocyclohexane (C6H6F6)2 are thoroughly investigated. The excess electron systems are designed by doping alkaline earth metals (AEMs) on fluorine face and superalkalis on hydrogen face of Janus dimer. The higher values of vertical ionization energies (VIE) and interaction energies (Eint), confirm the electronic and thermodynamic stabilities of the designed complexes, respectively. Natural bond orbital (NBO) analysis is performed, and the excess electron character of the complexes is confirmed through frontier molecular orbital (FMO) analysis by highest occupied molecular orbital (HOMO) iso-densities. FMO shows a significant decrease in energy gaps (Egap) of the complexes (i.e., Eg = 1.80–3.12 eV), compared to the stacked Janus dimer (i.e., Eg = 9.41 eV). The transparency of the complexes to UV region is confirmed through UV–vis analyses, revealing their maximum absorption in visible and near-IR regions. The higher NLO response of the designed excess electron systems is further proved by the greater values of first hyperpolarizability (β

o
) i.e., up to 1.70 × 106 au. Moreover, the time dependent-density functional theory (TD-DFT) computations and two-level model are employed to investigate the controlling factors of hyperpolarizability, illustrating the contribution of transition energy (∆E3), change in dipole moment (∆μ) and oscillator strength (f

o
) in controlling the β

o
. Ab-initio molecular dynamics (AIMD) simulation further confirm that the designed superalkalide complexes are kinetically and thermally stable. The thorough investigation of these excess electron systems proves them an appropriate candidate for NLO applications.
Reconstructing redshift distributions with photometric galaxy clustering
Authors: Peng Hui , Yu Yu 
Published: October 2024

Abstract
The accurate determination of the true redshift distributions in tomographic bins is
critical for cosmological constraints from photometric surveys. The proposed redshift
self-calibration method, which utilizes the photometric galaxy clustering alone, is highly
convenient and avoids the challenges from incomplete or unrepresentative spectroscopic samples in
external calibration. However, the imperfection of the theoretical approximation on broad bins as
well as the flaw of the algorithm in previous work [1] risk the accuracy and
application of the method. In this paper, we propose the improved self-calibration algorithm that
incorporates novel update rules, which effectively accounts for heteroskedastic weights and noisy
data with negative values. The improved algorithm greatly expands the application range of
self-calibration method and accurately reconstructs the redshift distributions for various mock
data. Using the luminous red galaxy (LRG) sample of the Dark Energy Spectroscopic Instrument
(DESI) survey, we find that the reconstructed results are comparable to the state-of-the-art
external calibration. This suggests the exciting prospect of using photometric galaxy clustering
to reconstruct redshift distributions in the cosmological analysis of survey data.
Numerical methods for scalar field dark energy in tabletop experiments and Lunar Laser Ranging
Authors: Fischer Hauke , Sedmik René I.P. 
Published: October 2024

Abstract
Numerous tabletop experiments have been dedicated to exploring the manifestations of screened scalar field dark energy, such as symmetron or chameleon fields. Precise theoretical predictions require simulating field configurations within the respective experiments. This paper focuses onto the less-explored environment-dependent dilaton field, which emerges in the strong coupling limit of string theory. Due to its exponential self-coupling, this field can exhibit significantly steeper slopes compared to symmetron and chameleon fields, and the equations of motion can be challenging to solve with standard machine precision. We present the first exact solution for the geometry of a vacuum region between two infinitely extended parallel plates. This solution serves as a benchmark for testing the accuracy of numerical solvers. By reparametrizing the model and transforming the equations of motion, we show how to make the model computable across the entire experimentally accessible parameter space. To simulate the dilaton field in one- and two-mirror geometries, as well as spherical configurations, we introduce a non-uniform finite difference method. Additionally, we provide an algorithm for solving the stationary Schrödinger equation for a fermion in one dimension in the presence of a dilaton field. The algorithms developed here are not limited to the dilaton field, but can be applied to similar scalar-tensor theories as well. We demonstrate such applications at hand of the chameleon and symmetron field. Our computational tools have practical applications in a variety of experimental contexts, including gravity resonance spectroscopy (q
Bounce), Lunar Laser Ranging (LLR), and the upcoming Casimir and Non-Newtonian Force Experiment (cannex). A Mathematica implementation of all algorithms is provided.
Parametric resonance of gravitational waves in general scalar-tensor theories
Authors: Cai Yi-Fu , Domènech Guillem , Ganz Alexander , Jiang Jie , Lin Chunshan , Wang Bo 
Published: October 2024

Abstract
Gravitational waves offer a potent mean to test the underlying theory of gravity. In general theories of gravity, such as scalar-tensor theories, one expects modifications in the friction term and the sound speed in the gravitational wave equation. In that case, rapid oscillations in such coefficients, e.g. due to an oscillating scalar field, may lead to narrow parametric resonances in the gravitational wave strain. We perform a general analysis of such possibility within DHOST theories. We use disformal transformations to find the theory space with larger resonances, within an effective field theory approach. We then apply our formalism to a non-minimally coupled ultra-light dark matter scalar field, assuming the presence of a primordial gravitational wave background, e.g., from inflation. We find that the resonant peaks in the spectral density may be detectable by forthcoming detectors such as LISA, Taiji, Einstein Telescope and Cosmic Explorer.
Deep Neural Network Closed-loop with Raw Data for Optical Resident Space Object Detection
Authors: Zhao He , Sun Rong-Yu , Yu Sheng-Xian 
Published: October 2024

Abstract
Optical survey is an important means for observing resident space objects and space situational awareness. With the application of astronomical techniques and reduction method, wide field of view telescopes have made significant contributions in discovering and identifying resident space objects. However, with the development of modern optical and electronic technology, the detection limit of instruments and infrastructure has been greatly extended, leading to an extensive number of raw images and many more sources in these images. Challenges arise when reducing these data in terms of traditional measurement and calibration. Based on the amount of data, it is particularly feasible and reliable to apply machine learning algorithms. Here an end-to-end deep learning framework is developed, it is trained with a priori information on raw detections and the automatic detection task is performed on the new data acquired. The closed-loop is evaluated based on consecutive CCD images obtained with a dedicated space debris survey telescope. It is demonstrated that our framework can achieve high performance compared with the traditional method, and with data fusion, the efficiency of the system can be improved without changing hardware or deploying new devices. The technique deserves a wider application in many fields of observational astronomy.
Practical realization of the watt from Planck’s constant using radiation pressure
Authors: Simonds Brian J , Rogers Kyle A , Schulze Sven , Newell David , Shaw Gordon , Wahl Johannes , Williams Paul A , Lehman John H 
Published: October 2024

Abstract
A primary force standard is implemented to realize the watt through Planck’s constant by means of radiation pressure at the kilowatt level. The high amplification laser-pressure optic, or HALO, is a multiple reflection radiation pressure apparatus used for absolute radiometry of high-power lasers. In this work, a primary standard electrostatic force balance is used to measure the reflection-enhanced optical forces. With this configuration, the HALO is used to measure laser powers in the range of 100 W–5000 W from a 1070 nm fiber laser. The expanded uncertainty of the 5 kW measurement is 0.12%, which is both the lowest uncertainty multi-kW measurement and radiation pressure-based measurement to-date. The HALO result was validated against a thermal primary standard using a calibrated transfer standard at 2 kW. The degree of equivalence was 0.78% ± 1.12%, which demonstrates agreement within the uncertainties of these two primary standards.
Observation of high frequency Alfvén eigenmodes excited by RF-accelerated minority hydrogen ions in the EAST tokamak
Authors: Liu Lunan , Zhang Wei , Zhang Xinjun , Ochoukov R. , Qin Chengming , Zhu Yubao 
Published: October 2024

Abstract
The paper presents the original observation of high frequency Alfvén eigenmode excited by fast minority hydrogen ions accelerated by ion cyclotron range of frequency waves in EAST. The frequency of high frequency Alfvén eigenmodes is around

0.75
∼
0.8
∗

Ω
H

, where

Ω
H

is the cyclotron frequency of hydrogen ions evaluated at the low-field side plasma edge. It tracks the on-axis magnetic field Bt
and the edge plasma electron density ne
via the Alfvénic relation

ω
∼

B
t

∗

n
e

−
1

/

2

. The high frequency Alfvén eigenmodes are always accompanied by sub-cyclotron modes in several experiments at EAST, consistent with the high frequency Alfvén eigenmode detected on other conventional tokamaks, namely ASDEX Upgrade and DIII-D. Based on the previous study, these sub-cyclotron modes are consistent with the spectrum splitting produced by toroidal mode numbers (Gorelenkov et al 2003 Nucl. Fusion
43 228). We also found that the location of eigenmode excitation of high frequency Alfvén eigenmode driven by RF-accelerated minority hydrogen ions remains unchanged even though the cyclotron resonance location of hydrogen ions varies with Bt
.
Measuring the extent of trees outside of forests: a nature-based solution for net zero emissions in South Asia
Authors: Skole David L , Samek Jay , Mehra Swapan , Bajaj Rajaditya , Tanmay Tanishq , Suresh Sangeetha , Jindal Shrey , Ndalowa Dan 
Published: October 2024

Abstract
To reduce emissions of carbon and other greenhouse gases on a pathway that does not overshoot and keeps global average temperature increase to below the 1.5 °C target stipulated by the Paris Agreement, it shall be necessary to rely on nature-based solutions with atmospheric removals. Without activities that create removals by carbon sequestration it will not be possible to balance residual emissions. Policies that focus solely on reducing deforestation will only lower future emissions. On the other hand, activities that include regeneration or regrowth of tree biomass can be used to create net-zero emissions through carbon sequestration and atmospheric removals now. New methods demonstrated here using high resolution remote sensing and deep machine learning enable analyses of carbon stocks of individual trees outside of forests (TOF). Allometric scaling models based on tree crowns at very high spatial resolution (<0.5 m) can map carbon stocks across large landscapes of millions of trees outside of forests. In addition to carbon removals, these landscapes are also important to livelihoods for millions of rural farmers and most TOF activities have the capacity to bring more countries into climate mitigation while also providing adaptation benefits. Here were present a multi-resolution, multi-sensor method that provides a way to measure carbon at the individual tree level in TOF landscapes in India. The results of this analysis show the effectiveness of mapping trees outside of forest across a range of satellite data resolution from 0.5 m to 10 m and for measuring carbon across large landscapes at the individual tree scale.
Arctic amplification causes earlier onset of seasonal tree growth in northeastern Siberia
Authors: Kirdyanov Alexander V , Kolmogorov Alexey I , Kruse Stefan , Herzschuh Ulrike , Arzac Alberto , Pestryakova Lyudmila A , Nikolaev Anatoly N , Bebchuk Tatiana , Büntgen Ulf 
Published: October 2024

Abstract
Although recent warming affects the high-northern latitudes at an unprecedented rate, little is known about its impact on boreal forests because in situ observations from remote ecosystems in Siberia are sparse. Here, we analyse the radial growth and climate sensitivity of 54 Cajander larches (Larix cajanderi Mayr.) from three sites across the northern treeline ecotone within the Omoloy river basin in northeastern Siberia. Three independent tree-ring width chronologies span 279–499 years and exhibit distinct summer temperature signals. These records further reveal evidence for sufficiently earlier onsets of growing seasons since the middle of the 20th century. This phenological shift coincides with rapidly increasing May temperatures and associated earlier snowmelt. Our findings reinforce the importance of high-precision ground measurements from remote regions in Siberia to better understand how warming-induced changes in the functioning and productivity of the boreal forest influence carbon, nutrient, and water cycle dynamics.
Lattice polymers near a permeable interface
Authors: Bradly C J , Beaton N R , Owczarek A L 
Published: October 2024

Abstract
We study the localisation of lattice polymer models near a permeable interface in two dimensions. Localisation can arise due to an interaction between the polymer and the interface, and can be altered by a preference for the bulk solvent on one side or by the application of a force to manipulate the polymer. Different combinations of these three effects give slightly different statistical mechanical behaviours. The canonical lattice model of polymers is the self-avoiding walk which we mainly study with Monte Carlo simulation to calculate the phase diagram and critical phenomena. For comparison, a solvable directed walk version is also defined and the phase diagrams are compared for each case. We find broad agreement between the two models, and most minor differences can be understood as due to the different entropic contributions. In the limit where the bulk solvent on one side is overwhelmingly preferred we see how the localisation transition transforms to the adsorption transition; the permeable interface becomes effectively an impermeable surface.