bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reproducible spectral CT thermometry with liver-mimicking phantoms for image-guided thermal ablation
Authors: Liu Leening P , Pua Rizza , Rosario-Berrios Derick N , Sandvold Olivia F , Perkins Amy E , Cormode David P , Shapira Nadav , Soulen Michael C , Noël Peter B 
Published: January 2024

Abstract

Objectives. Evaluate the reproducibility, temperature tolerance, and radiation dose requirements of spectral CT thermometry in tissue-mimicking phantoms to establish its utility for non-invasive temperature monitoring of thermal ablations. Methods. Three liver mimicking phantoms embedded with temperature sensors were individually scanned with a dual-layer spectral CT at different radiation dose levels during heating (35 °C–80 °C). Physical density maps were reconstructed from spectral results using varying reconstruction parameters. Thermal volumetric expansion was then measured at each temperature sensor every 5 °C in order to establish a correlation between physical density and temperature. Linear regressions were applied based on thermal volumetric expansion for each phantom, and coefficient of variation for fit parameters was calculated to characterize reproducibility of spectral CT thermometry. Additionally, temperature tolerance was determined to evaluate effects of acquisition and reconstruction parameters. The resulting minimum radiation dose to meet the clinical temperature accuracy requirement was determined for each slice thickness with and without additional denoising. Results. Thermal volumetric expansion was robustly replicated in all three phantoms, with a correlation coefficient variation of only 0.43%. Similarly, the coefficient of variation for the slope and intercept were 9.6% and 0.08%, respectively, indicating reproducibility of the spectral CT thermometry. Temperature tolerance ranged from 2 °C to 23 °C, decreasing with increased radiation dose, slice thickness, and iterative reconstruction level. To meet the clinical requirement for temperature tolerance, the minimum required radiation dose ranged from 20, 30, and 57 mGy for slice thickness of 2, 3, and 5 mm, respectively, but was reduced to 2 mGy with additional denoising. Conclusions. Spectral CT thermometry demonstrated reproducibility across three liver-mimicking phantoms and illustrated the clinical requirement for temperature tolerance can be met for different slice thicknesses. The reproducibility and temperature accuracy of spectral CT thermometry enable its clinical application for non-invasive temperature monitoring of thermal ablation.
Scintillation and cherenkov photon counting detectors with analog silicon photomultipliers for TOF-PET
Authors: Cates Joshua W , Choong Woon-Seng , Brubaker Erik 
Published: January 2024

Abstract

Objective. Standard signal processing approaches for scintillation detectors in positron emission tomography (PET) derive accurate estimates for 511 keV photon time of interaction and energy imparted to the detection media from aggregate characteristics of electronic pulse shapes. The ultimate realization of a scintillation detector for PET is one that provides a unique timestamp and position for each detected scintillation photon. Detectors with these capabilities enable advanced concepts for three-dimensional (3D) position and time of interaction estimation with methods that exploit the spatiotemporal arrival time kinetics of individual scintillation photons. Approach. In this work, we show that taking into consideration the temporal photon emission density of a scintillator, the channel density of an analog silicon photomultiplier (SiPM) array, and employing fast electronic readout with digital signal processing, a detector that counts and timestamps scintillation photons can be realized. To demonstrate this approach, a prototype detector was constructed, comprising multichannel electronic readout for a bismuth germanate (BGO) scintillator coupled to an SiPM array. Main Results. In proof-of-concept measurements with this detector, we were able to count and provide unique timestamps for 66% of all optical photons, where the remaining 34% (two-or-more-photon pulses) are also independently counted, but each photon bunch shares a common timestamp. We show this detector concept can implement 3D positioning of 511 keV photon interactions and thereby enable corrections for time of interaction estimators. The detector achieved 17.6% energy resolution at 511 keV and 237 ± 10 ps full-width-at-half-maximum coincidence time resolution (CTR) (fast spectral component) versus a reference detector. We outline the methodology, readout, and approach for achieving this detector capability in first-ever, proof-of-concept measurements for scintillation photon counting detector with analog silicon photomultipliers. Significance. The presented detector concept is a promising design for large area, high sensitivity TOF-PET detector modules that can implement advanced event positioning and time of interaction estimators, which could push state-of-the-art performance.
Quantum annealing-based computed tomography using variational approach for a real-number image reconstruction
Authors: Haga Akihiro 
Published: January 2024

Abstract

Objective. Despite recent advancements in quantum computing, the limited number of available qubits has hindered progress in CT reconstruction. This study investigates the feasibility of utilizing quantum annealing-based computed tomography (QACT) with current quantum bit levels. Approach. The QACT algorithm aims to precisely solve quadratic unconstrained binary optimization problems. Furthermore, a novel approach is proposed to reconstruct images by approximating real numbers using the variational method. This approach allows for accurate CT image reconstruction using a small number of qubits. The study examines the impact of projection data quantity and noise on various image sizes ranging from 4 × 4 to 24 × 24 pixels. The reconstructed results are compared against conventional reconstruction algorithms, namely maximum likelihood expectation maximization (MLEM) and filtered back projection (FBP). Main result. By employing the variational approach and utilizing two qubits for each pixel of the image, accurate reconstruction was achieved with an adequate number of projections. Under conditions of abundant projections and lower noise levels, the image quality in QACT algorithm outperformed that of MLEM and FBP algorithms. However, in situations with limited projection data and in the presence of noise, the image quality in QACT was inferior to that in MLEM. Significance. This study developed the QACT reconstruction algorithm using the variational approach for real-number reconstruction. Remarkably, only 2 qubits were required for each pixel representation, demonstrating their sufficiency for accurate reconstruction.
Model magnetospheric accretion and bipolar jets with intense lasers
Authors: Xing Chunqing , Zhong Jiayong , Tang Pengfei , Zhao Xu , Zhang Zhe , Sun Wei , Yuan Dawei , Wei Huigang , Han Bo , Lei Zhu , Liu Huiya , Xiong Jun , Zhang Yihang , Cheng Lei , Dong Yufeng , Wang Jianzhao , Zhang Zhimeng , Teng Jian , An Weiming , Ping Yongli , Qiao Bin , Zhou Weimin , Zhu Jianqiang , Zhao Gang , Zhang Jie 
Published: January 2024

Abstract
Astronomical observations show that classical T Tauri stars (TTSs) always possess active accretion activity and jet launching. However, limited by high dust opacity and observation resolution, direct investigations of the details are arduous. The physics of the accretion activity and the jet formation is still an open question. In this paper, we carry out the experiment with intense lasers irradiating a newly designed eight-coil capacitor target. We observe a process in laboratory which is similar to the truncation process of the magnetospheric accretion around TTSs. Both impediment processes result from a relatively strong magnetic field compared to the ram and thermal pressures of the material. We also observe a jet formation process in laboratory which is similar to the jet formation model proposed by Cantó et al (1988). Both formation processes result from converging supersonic flows. At last, we discuss the feasibility of a jet formation model based on magnetospheric accretion.
Controlled adsorption of gas molecules by tuning porosity of titanium film
Authors: Han Sangwug , Kim Taehyun , Lee Jubeom , Kim Gyungtae , Hyun Moonseop , Hong Daewon , Choi Jihoon 
Published: January 2024

Abstract
Within microelectromechanical system sensors, the establishment of a vacuum environment is a prerequisite for the control of specific residual gas molecules. At the wafer-level package stage, the interior of the sensor can be easily converted into a vacuum environment. However, after packaging, degassing occurs due to the accumulation of fumes with additional processing, resulting in a significant reduction in sensor reliability. To counteract this, non-evaporable getter (NEG) film is commonly packaged together with the sensor to absorb the outgassing gas molecules and maintain a vacuum environment within the sensor. Most NEG films require an activation process to migrate the adsorbed gas molecules from the surface to the bulk by thermal annealing. Recently, NEG films have been considered to reduce the activation temperature and time to avoid heat damage. Depositing an anti-oxidant layer on NEG film or alloying the NEG film with metallic materials through co-sputtering to create a distinct valence state during activation was found to prevent further oxidation of NEG film. However, these methods require expensive materials and fabrication equipment. In this study, we demonstrate that a much lower activation temperature (T = 350 °C) and time (t = 10 min) for Ti NEG film can be achieved by controlling the surface morphology depending on the deposition method and condition, without requiring further treatment such as the deposition of a capping layer or co-sputtering. Increasing the grain size of the Ti NEG film results in a larger surface area, which enables more efficient adsorption of gas molecules. Additionally, higher porosity in the film increases the diffusion of gas molecules, thus enhancing the overall gas adsorption capacity. Our experiments show that the Ti NEG film, which was deposited at 7.8 Å s−1 using a sputtering method, exhibited a grain size of 411 nm and a surface roughness of 59.185 nm. Furthermore, after an activation process at 350 °C for 10 min, the atomic ratio of the adsorbed gas molecules was 23.14%.
Superconducting state generated dynamically from distant pair source and drain
Authors: Ma E S , Song Z 
Published: January 2024

Abstract
It has been well established that the origin of p-wave superconductivity is the balance between pair creation and annihilation, described by the spin-less fermionic Kitaev chain model. In this work, we study the dynamics of a composite system where the pair source and drain are spatially separated by a long distance. We show that this non-Hermitian system possesses a high-order exceptional point (EP) when only a source or drain is considered. The EP dynamics provide a clear picture: A pair source can fully fill the system with pairs, while a drain can completely empty the system. When the two coexist simultaneously, the dynamics depend on the distance and the relative phase between the pair creation and annihilation terms. Analytical analysis and numerical simulation results show that the superconducting state can be dynamically established at the resonant pair source and drain: from an initial empty state to a stationary state with the maximal pair order parameter. It provides an alternative way of understanding the mechanism of the nonequilibrium superconducting state.
Topological end states in one-dimensional Su–Schrieffer–Heeger-like chain electric circuits
Authors: Huang Jinke , Guo Shengqun , Qiu Shiqi , Zhuang Fengjiang , Su Shaojian , Huang Ruimin , Lin Zhili , Qiu Weibin , Su Jianchao , Wang Xin 
Published: January 2024

Abstract
Topological circuits provide an excellent experimental platform for observing topological states. In this work, we construct a one-dimensional Su-Schrieffer-Heeger(SSH)-like chain in topological electric circuits and find two types of end states, only the type-II end states are pinned at zero admittance. The topological properties can be characterized by the sum of Zak phases, which related to the ratio of inter-cell capacitors to intra-cell capacitors. Theoretical and experimental results of these two end states can be well reflected through impedance peaks. We examine the robustness of these two end states by adding extra capacitors. Our work enriches the study of topological circuits and provides an example for investigating the exotic topological physics.
Search for production of dark fermion candidates in association with heavy neutral gauge boson decaying to dimuon in proton-proton collisions at
TeV using CMS open data*
Authors: Mahmoud Y. , Abdallah H. , Hussein M. T. , Elgammal S. 
Published: January 2024

Abstract
In this study, we conducted a search for dark matter using a part of the data recorded by the CMS experiment during run-I of the LHC in 2012 with a center of mass energy of 8 TeV and an integrated luminosity of 11.6 fb−1. These data were gathered from the CMS open data. Dark matter, in the framework of the simplified model (mono-Z

), can be produced from proton-proton collisions in association with a new hypothetical gauge boson, Z

. Thus, the search was conducted in the dimuon plus large missing transverse momentum channel. One benchmark scenario of mono-Z

, which is known as light vector, was used for interpreting the CMS open data. No evidence of dark matter was observed, and exclusion limits were set on the masses of dark matter and Z

at 95% confidence level.
Soft robotics for farm to fork: applications in agriculture & farming
Authors: Armanini Costanza , Junge Kai , Johnson Philip , Whitfield Charles , Renda Federico , Calisti Marcello , Hughes Josie 
Published: January 2024

Abstract
Agricultural tasks and environments range from harsh field conditions with semi-structured produce or animals, through to post-processing tasks in food-processing environments. From farm to fork, the development and application of soft robotics offers a plethora of potential uses. Robust yet compliant interactions between farm produce and machines will enable new capabilities and optimize existing processes. There is also an opportunity to explore how modeling tools used in soft robotics can be applied to improve our representation and understanding of the soft and compliant structures common in agriculture. In this review, we seek to highlight the potential for soft robotics technologies within the food system, and also the unique challenges that must be addressed when developing soft robotics systems for this problem domain. We conclude with an outlook on potential directions for meaningful and sustainable impact, and also how our outlook on both soft robotics and agriculture must evolve in order to achieve the required paradigm shift.
Strong increase in mortality attributable to ozone pollution under a climate change and demographic scenario
Authors: Akritidis Dimitris , Bacer Sara , Zanis Prodromos , Georgoulias Aristeidis K , Chowdhury Sourangsu , Horowitz Larry W , Naik Vaishali , O’Connor Fiona M , Keeble James , Sager Philippe Le , van Noije Twan , Zhou Putian , Turnock Steven , West J Jason , Lelieveld Jos , Pozzer Andrea 
Published: January 2024

Abstract
Long-term exposure to ambient ozone (O3) is associated with excess respiratory mortality. Pollution emissions, demographic, and climate changes are expected to drive future ozone-related mortality. Here, we assess global mortality attributable to ozone according to an Intergovernmental Panel on Climate Change (IPCC) Shared Socioeconomic Pathway (SSP) scenario applied in Coupled Model Intercomparison Project Phase 6 (CMIP6) models, projecting a temperature increase of about 3.6 °C by the end of the century. We estimated ozone-related mortality on a global scale up to 2090 following the Global Burden of Disease (GBD) 2019 approach, using bias-corrected simulations from three CMIP6 Earth System Models (ESMs) under the SSP3-7.0 emissions scenario. Based on the three ESMs simulations, global ozone-related mortality by 2090 will amount to 2.79 M [95% CI 0.97 M–5.23 M] to 3.12 M [95% CI 1.11 M–5.75 M] per year, approximately ninefold that of the 327 K [95% CI 103 K–652 K] deaths per year in 2000. Climate change alone may lead to an increase of ozone-related mortality in 2090 between 42 K [95% CI −37 K–122 K] and 217 K [95% CI 68 K–367 K] per year. Population growth and ageing are associated with an increase in global ozone-related mortality by a factor of 5.34, while the increase by ozone trends alone ranges between factors of 1.48 and 1.7. Ambient ozone pollution under the high-emissions SSP3-7.0 scenario is projected to become a significant human health risk factor. Yet, optimizing living conditions and healthcare standards worldwide to the optimal ones today (application of minimum baseline mortality rates) will help mitigate the adverse consequences associated with population growth and ageing, and ozone increases caused by pollution emissions and climate change.
Ferroelectricity in twisted double bilayer graphene
Authors: Du Renjun , Xiao Jingkuan , Zhang Di , Cai Xiaofan , Jiang Siqi , Lian Fuzhuo , Watanabe Kenji , Taniguchi Takashi , Wang Lei , Yu Geliang 
Published: January 2024

Abstract
Two-dimensional (2D) ferroelectrics can maintain electrical polarization up to room temperature and are, therefore, promising for next-generation nonvolatile memories. Although natural 2D ferroelectrics are few, moiré superlattices provide us with a generalized method to construct ferroelectrics from non-ferroelectric parent materials. We report a realization of ferroelectric hysteresis in an AB-BA stacked twisted double bilayer graphene (TDBG) system. The ferroelectric polarization is prominent at zero external displacement field and reduces upon increasing displacement fields. TDBG in the AB-BA configuration is an intriguing system, which facilitates ferroelectricity even without the assistance of any boron nitride layers; however, in the AB-AB stacking case, the development of polarization necessitates the presence of a second superlattice induced by the adjacent boron nitride layer. Therefore, twisted multilayer graphene offers us a fascinating field to explore 2D ferroelectricity.
The deep-acceptor nature of the chalcogen vacancies in 2D transition-metal dichalcogenides
Authors: Khalid Shoaib , Medasani Bharat , Lyons John L , Wickramaratne Darshana , Janotti Anderson 
Published: January 2024

Abstract
Chalcogen vacancies in the semiconducting monolayer transition-metal dichalcogenides (TMDs) have frequently been invoked to explain a wide range of phenomena, including both unintentional p-type and n-type conductivity, as well as sub-band gap defect levels measured via tunneling or optical spectroscopy. These conflicting interpretations of the deep versus shallow nature of the chalcogen vacancies are due in part to shortcomings in prior first-principles calculations of defects in the semiconducting two-dimensional TMDs that have been used to explain experimental observations. Here we report results of hybrid density functional calculations for the chalcogen vacancy in a series of monolayer TMDs, correctly referencing the thermodynamic charge transition levels to the fundamental band gap (as opposed to the optical band gap). We find that the chalcogen vacancies are deep acceptors and cannot lead to n-type or p-type conductivity. Both the (0/−1) and (−1/−2) transition levels occur in the gap, leading to paramagnetic charge states

S
=
1

/

2

and S = 1, respectively, in a collinear-spin representation. We discuss trends in terms of the band alignments between the TMDs, which can serve as a guide to future experimental studies of vacancy behavior.
Minimizing surface roughness and back wall dross for fiber laser micro-cutting on AISI 316 L tubes using response surface methodology
Authors: García-López Erika , Siller Hector , Vazquez-Lepe Elisa , Ramirez-Galindo José Guillermo , Rodriguez Ciro A 
Published: January 2024

Abstract
A response surface methodology (RSM) was performed to study the influence of spot overlapping and pulse energy on back wall dross and surface roughness for fiber laser cutting of AISI 316 L stainless steel minitubes. Three treatments were compared to expel molten material (argon gas, compressed air, and a control test). Our results indicated that back wall dross and dross height reduction is observed when argon gas or compressed air is used through tubes compared with the control test. Additionally, a higher value of spot overlap (87.49%) and a lower value of pulse energy (30.31 mJ) resulted as the optimal parameters to cut minitubes.
Improvement of wear and hot melt loss resistance of metal carbide layers on H13 steel
Authors: Zeng Zhi-Zhong , Lin Dan , Shang Jian 
Published: January 2024

Abstract
In this paper, H13 steel was pre-carburized. Then niobizing and vanadizing layers were prepared by pack cementation method. The high temperature friction and wear properties and hot melt loss properties of different layers and substrates were studied by microhardness tester, metallographic microscope, scanning electron microscope, energy dispersive spectrometer, high temperature friction and wear tester, optical profilometer and Raman spectrometer. The results show that the thickness of the vanadizing layer is 12.7 μm, and the microhardness of the niobizing layer and the vanadizing layer is close, which is about 5 times that of the matrix. The lowest wear rate at 500 °C of the vanadizing layer is 1.03 , which is about 1/6 of the matrix. The vanadizing layer and niobiumizing layer can effectively reduce the friction coefficient, greatly improve the surface hardness and wear resistance of H13 steel, and prolong its service life. The comprehensive performance of vanadizing layer is the best. The vanadizing and niobiumizing treatment can significantly improve hot melt loss resistance of H13 steel and it can be used to prolong the serving life of hot die casting mold for Al.
A polarization insensitive terahertz tri-band graphene metasurface absorber
Authors: Sur Surajit , Bhattacharya Rajarshi 
Published: January 2024

Abstract
A graphene-based tri-band perfect metasurface absorber is presented for the far-infrared frequency range. A two-dimensional periodic pattern of graphene patches is created on a thin SiO2 dielectric layer, which is backed by a gold ground plane of sufficient thickness (

t

) ensuring zero transmission of the impinging electromagnetic (EM) wave. An array of graphene elliptical discs is placed around graphene square patches and thin graphene strips are used to connect these elliptical patches to the square patches. In terms of the lowest frequency of absorption, the proposed absorber seems to be a thin one as

t
∼

λ

max

/

13

.

It is also considered compact because the periodicity of the cells is on the order of

λ

max

/

22

.

The absorption spectrum gives three perfect absorption peaks with absorptivity greater than 99% at 5.76 and 9.06 THz. Further, the absorptivity is better than 96% at 7.86 THz. The performance of the proposed absorber remains invariant with change in polarization of the incident wave. It is revealed that this absorber performs satisfactorily throughout a broad angular range of incidence of about ± 60°.