bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular photothermal effects, diffusion, and sample flow in time-resolved spectroscopy and microscopy
Authors: Cho Minhaeng
Published: December 2023

Time-resolved pump–probe and two-dimensional spectroscopy are widely used to study ultrafast chemical and biological processes in solutions. However, the corresponding signals at long times can be contaminated by molecular photothermal effects, which are caused by the nonradiative heat dissipation of photoexcited molecules to the surroundings. Additionally, molecular diffusion affects the transient spectroscopic signals because photoexcited molecules can diffuse away from the pump and probe beam focuses. Recently, a theoretical description of molecular photothermal effects on time-resolved IR spectroscopy was reported. In this work, I consider the molecular photothermal process, molecular diffusion, and sample flow to develop a generalized theoretical description of time-resolved spectroscopy. The present work can be used to interpret time-resolved spectroscopic signals of electronic or vibrational chromophores and understand the rate and mechanisms of the conversion of high-frequency molecular electronic and vibrational energy to solvent kinetic energy in condensed phases.
Remote regulation on the hydration sites of adenine molecules via derivatization
Authors: Ding Yuanqi , Zhang Chi , Xie Lei , Xu Wei
Published: December 2023

Hydration, as a ubiquitous and vital phenomenon in nature, has attracted great attention in the field of surface science concerning the fundamental interactions between water and organic molecules. However, the role of functional group derivatization is still elusive in terms of its potential impact on hydration. By the combination of high-resolution scanning tunneling microscopy imaging and density functional theory calculations, the hydration of 9mA molecules was realized on Au(111) in real space, forming 9mA–H2O–9mA structures. In comparison with the hydration of adenine molecules, methyl derivatization is experimentally found to remotely regulate the hydration sites from the imidazole ring to the pyrimidine ring and is further theoretically revealed to allow intramolecular electron redistribution and, therefore, steer the priority of the hydration sites. These results provide sub-molecular understandings of the relationship between derivatization and hydration, which would shed light on the regulation of hydration processes in chemically and biologically related systems.
Effort Foraging Task reveals positive correlation between individual differences in the cost of cognitive and physical effort in humans
Authors: Bustamante Laura A. , Oshinowo Temitope , Lee Jeremy R. , Tong Elizabeth , Burton Allison R. , Shenhav Amitai , Cohen Jonathan D. , Daw Nathaniel D.
Published: December 2023

Effort-based decisions, in which people weigh potential future rewards against effort costs required to achieve those rewards involve both cognitive and physical effort, though the mechanistic relationship between them is not yet understood. Here, we use an individual differences approach to isolate and measure the computational processes underlying effort-based decisions and test the association between cognitive and physical domains. Patch foraging is an ecologically valid reward rate maximization problem with well-developed theoretical tools. We developed the Effort Foraging Task, which embedded cognitive or physical effort into patch foraging, to quantify the cost of both cognitive and physical effort indirectly, by their effects on foraging choices. Participants chose between harvesting a depleting patch, or traveling to a new patch that was costly in time and effort. Participants’ exit thresholds (reflecting the reward they expected to receive by harvesting when they chose to travel to a new patch) were sensitive to cognitive and physical effort demands, allowing us to quantify the perceived effort cost in monetary terms. The indirect sequential choice style revealed effort-seeking behavior in a minority of participants (preferring high over low effort) that has apparently been missed by many previous approaches. Individual differences in cognitive and physical effort costs were positively correlated, suggesting that these are perceived and processed in common. We used canonical correlation analysis to probe the relationship of task measures to self-reported affect and motivation, and found correlations of cognitive effort with anxiety, cognitive function, behavioral activation, and self-efficacy, but no similar correlations with physical effort.
Late-life shift in caloric intake affects fly metabolism and longevity
Authors: Li Michael , Macro Jacob , Meadows Kali , Mishra Dushyant , Martin Dominique , Olson Sara , Huggins Billy Joe , Graveley Brenton R. , Li James Y. H. , Rogina Blanka
Published: December 2023

The prevalence of obesity is increasing in older adults and contributes to age-related decline. Caloric restriction (CR) alleviates obesity phenotypes and delays the onset of age-related changes. However, how late in life organisms benefit from switching from a high-(H) to a low-calorie (L) diet is unclear. We transferred male flies from a H to a L (HL) diet or vice versa (LH) at different times during life. Both shifts immediately change fly rate of aging even when applied late in life. HL shift rapidly reduces fly mortality rate to briefly lower rate than in flies on a constant L diet, and extends lifespan. Transcriptomic analysis uncovers that flies aged on H diet have acquired increased stress response, which may have temporal advantage over flies aged on L diet and leads to rapid decrease in mortality rate after HL switch. Conversely, a LH shift increases mortality rate, which is temporarily higher than in flies aged on a H diet, and shortens lifespan. Unexpectedly, more abundant transcriptomic changes accompanied LH shift, including increase in ribosome biogenesis, stress response and growth. These changes reflect protection from sudden release of ROS, energy storage, and use of energy to growth, which all likely contribute to higher mortality rate. As the beneficial effects of CR on physiology and lifespan are conserved across many organisms, our study provides framework to study underlying mechanisms of CR interventions that counteract the detrimental effects of H diets and reduce rate of aging even when initiated later in life.
Constructing molecule-metal relay catalysis over heterophase metallene for high-performance rechargeable zinc-nitrate/ethanol batteries
Authors: Zhou Jingwen , Xiong Yuecheng , Sun Mingzi , Xu Zhihang , Wang Yunhao , Lu Pengyi , Liu Fu , Hao Fengkun , Feng Tianyi , Ma Yangbo , Yin Jinwen , Ye Chenliang , Chen Biao , Xi Shibo , Zhu Ye , Huang Bolong , Fan Zhanxi
Published: December 2023

Zinc-nitrate batteries can integrate energy supply, ammonia electrosynthesis, and sewage disposal into one electrochemical device. However, current zinc-nitrate batteries still severely suffer from the limited energy density and poor rechargeability. Here, we report the synthesis of tetraphenylporphyrin (tpp)-modified heterophase (amorphous/crystalline) rhodium-copper alloy metallenes (RhCu M-tpp). Using RhCu M-tpp as a bifunctional catalyst for nitrate reduction reaction (NO
3
RR) and ethanol oxidation reaction in neutral solution, a highly rechargeable and low-overpotential zinc-nitrate/ethanol battery is successfully constructed, which exhibits outstanding energy density of 117364.6 Wh kg
−1
cat
, superior rate capability, excellent cycling stability of ~400 cycles, and potential ammonium acetate production. Ex/in situ experimental studies and theoretical calculations reveal that there is a molecule-metal relay catalysis in NO
3
RR over RhCu M-tpp that significantly facilitates the ammonia selectivity and reaction kinetics via a low energy barrier pathway. This work provides an effective design strategy of multifunctional metal-based catalysts toward the high-performance zinc-based hybrid energy systems.
Homeostatic, repertoire and transcriptional relationships between colon T regulatory cell subsets
Authors: Ramanan Deepshika , Chowdhary Kaitavjeet , Candéias Serge M. , Sassone-Corsi Martina , Gelineau Adelaide , Mathis Diane , Benoist Christophe
Published: December 2023

Foxp3
+
regulatory T cells (Tregs) in the colon are key to promoting peaceful coexistence with symbiotic microbes. Differentiated in either thymic or peripheral locations, and modulated by microbes and other cellular influencers, colonic Treg subsets have been identified through key transcription factors (TFs; Helios, Rorγ, Gata3, and cMaf), but their interrelationships are unclear. Applying a multimodal array of immunologic, genomic, and microbiological assays, we find more overlap than expected between populations. The key TFs (Rorγ, Helios, Gata3, and cMaf) play different roles, some essential for subset identity, others driving functional gene signatures. Functional divergence was clearest under challenge. Single-cell genomics revealed a spectrum of phenotypes between the Helios+ and Rorγ+ poles, different Treg-inducing bacteria inducing the same Treg phenotypes to varying degrees, not distinct populations. TCR repertoires in monocolonized mice revealed that Helios+ and Rorγ+ Tregs are related and cannot be uniquely equated to tTreg and pTreg. Comparison of spleen and colon repertoires revealed that 2 to 5% of clonotypes are shared between the locations. We propose that rather than the origin of their differentiation, tissue-specific cues dictate the spectrum of colonic Treg phenotypes.
The Lemaître–Hubble diagram in axial Bianchi IX universes with comoving dust
Authors: Valent Galliano , Tilquin André , Schücker Thomas
Published: December 2023

Axial Bianchi IX universes have compact, simply connected, homogeneous three-spaces and feature minimal symmetry breaking of the cosmological principle. We consider a positive cosmological constant, comoving dust and a mildly anisotropic expansion in the recent past,z < 6, which might be observable in the near future with the James Webb Space Telescope and the Vera Rubin Observatory. To this end we compute the direction dependent redshift and apparent luminosity of type 1a supernovae.

To the memory of Vaughan Jones
HPC-driven computational reproducibility in numerical relativity codes: a use case study with IllinoisGRMHD
Authors: Luo Yufeng , Zhang Qian , Haas Roland , Etienne Zachariah B , Allen Gabrielle
Published: December 2023

Reproducibility of results is a cornerstone of the scientific method. Scientific computing encounters two challenges when aiming for this goal. Firstly, reproducibility should not depend on details of the runtime environment, such as the compiler version or computing environment, so results are verifiable by third-parties. Secondly, different versions of software code executed in the same runtime environment should produce consistent numerical results for physical quantities. In this manuscript, we test the feasibility of reproducing scientific results obtained using the IllinoisGRMHD code that is part of an open-source community software for simulation in relativistic astrophysics, the Einstein Toolkit. We verify that numerical results of simulating a single isolated neutron star with IllinoisGRMHD can be reproduced, and compare them to results reported by the code authors in 2015. We use two different supercomputers: Expanse at SDSC, and Stampede2 at TACC. By compiling the source code archived along with the paper on both Expanse and Stampede2, we find that IllinoisGRMHD reproduces results published in its announcement paper up to errors comparable to round-off level changes in initial data parameters. We also verify that a current version of IllinoisGRMHD reproduces these results once we account for bug fixes which have occurred since the original publication.
Analysis of the adsorption characteristics of SF6 and its decomposition products in ZIF-67: based on GCMC and DFT
Authors: Zeng Fuping , Zhu Kexin , Guo Xinnuo , Li Haotian , Qiu Hao , Tang Ju
Published: December 2023

Given the superior performance of SF6 in arc extinguishing and its wide application in high voltage fields, the search for new adsorbent materials for SF6 and its main decomposition products holds significant importance in mitigating greenhouse gas potential and its implications for the environment and energy sectors. We chose ZIF-67, an organic framework with a high specific surface area and distinctive pore size structure, to address this important issue. Using the grand canonical Monte Carlo simulation approach, we investigated the adsorption of SF6 and its main decomposer gases by ZIF-67 at GPa. The interaction of ZIF-67 with SF6 and its main breakdown products was then examined at the level of atomic orbital interactions, with the adsorption energy and density of states estimated using density functional theory. The findings reveal that ZIF-67 has the best ability to capture H2S, with a saturation capacity of 3.2 mmol g−1 at room temperature. Its adsorption capacity for SOF2 and SO2F2 is about five to seven times higher than that of industrial adsorbents kdhF-03, and the working conditions are milder. The molecule radius and adsorption capacity are tightly correlated. An innovative method for the widespread recovery and treatment of SF6 and its byproducts is presented in this research. This paper aims to provide new insights and solutions to promote sustainable development in the power industry.
High-performance low-profile green electromagnetic interference shielding material for 5G mm-wave using characteristic mode theory
Authors: Li Shuying , Liu Liangliang , Jiang Yuying , Dai Huijuan , Tang Chunzi , Han Guodong , Gu Changqing , Li Zhuo
Published: December 2023

With the rapid development of 5G communication technology, high-frequency electromagnetic interference (EMI) shielding plays a vital role in the normal operation of electrical and electronic equipment and systems, and has attracted surging interest in 5G mm-wave applications. However, many current EMI shielding materials contain highly conductive materials, resulting in strong secondary reflection and environmental pollution. Here, we propose a green high-performance EMI shielding material for 5G mm-wave based on a metamaterial absorber (MMA). Characteristic mode theory and equivalent circuit are employed to inversely design the unit cell’s dimension and structure, as well as the resistive value of the proposed MMA. We reveal that from 22 to 43.5 GHz, the shielding effectiveness of higher than 30 dB, and the standard green index of SER < 3.01 dB and g
s ⩾ 1 can be realized whether the MMA is flat or even bent. Excellent agreement between the measured and simulated results verified the high performance of the proposed EMI shielding MMA. The transmittance of over 85.84% can be achieved within the 380 ∼ 800 nm spectrum. The proposed green EMI shielding material integrates multi-functionalities of low profile, flexibility, polarization-insensitiveness, wide-angle, and optical transparency, and can find potential applications in EMI shielding in complex electromagnetic environments.
Study on the influence of local optical field amplification effect on laser-induced damage of fused silica materials
Authors: Liu Yubo , Cai Jixing , Zhang Zequn , Yu Hao , Li Shun , Li Yi
Published: December 2023

Fused silica is an important part of optical components in large laser systems. Due to the limitation of manufacturing process, impurities and defects in the optical element would greatly reduce the service life of the optical element, and significantly reduce the final output of the laser performance. Aiming at the modulation effect of the internal defect of the component on the internal optical field of the component, the theoretical, simulation and experimental research are carried out. The results show that in the double-bubble impurity coupling, under the same radius R, when the impurity spacing is 1 λ, the local optical field amplification has a maximum value. The effect is equivalent to single-bubble modulation with radius 2 R–3 R. There is an extreme point of the modulated optical field between the air and fused silica crossing line for bubble impurities of different radii. The optical field modulation of small radius impurities is distributed behind the bubble impurities, and the modulation effect of large radius impurities is the maximum when the spacing is 2 λ. The temperature distribution curve of the fused silica element modulated by bubble impurities is consistent with the optical field distribution curve, showing a trend of decreasing slope. The presence of bubble impurities will cause the surface combustion wave of the component to flash and accelerate, and the bubble impurities will increase the generation and expansion rate of the surface combustion wave. This study provides a basis for reducing the uneven distribution of laser energy during the interaction between laser and fused silica, improving the lifetime of the overall optical system, and experimental measurement and analysis.
Defective ZrSe2: a promising candidate for spintronics applications
Authors: Kheirabadi Sharieh Jamalzadeh , Behzadi Fahimeh , Gity Farzan , Hurley Paul K , Khorrami Soroush Karimi , Behroozi Mohammadreza , Sanaee Maryam , Ansari Lida
Published: December 2023

The current study presents the electronic and magnetic properties of monolayer ZrSe2 nanoribbons. The impact of various point defects in the form of Zr or Se vacancies, and their combinations, on the nanoribbon electronic and magnetic properties are investigated using density functional theory calculations in hydrogen-terminated zigzag and armchair ZrSe2 nanoribbons. Although pristine ZrSe2 is non-magnetic, all the defective ZrSe2 structures exhibit ferromagnetic behavior. Our calculated results also show that the Zr and Se vacancy defects alter the total spin magnetic moment with D6Se, leading to a significant amount of 6.34 µB in the zigzag nanoribbon, while the largest magnetic moment of 5.52 µB is induced by D2Se−2 in the armchair structure, with the spin density predominantly distributed around the Zr atoms near the defect sites. Further, the impact of defects on the performance of the ZrSe2 nanoribbon-based devices is investigated. Our carrier transport calculations reveal spin-polarized current-voltage characteristics for both the zigzag and armchair devices, revealing negative differential resistance (NDR) feature. Moreover, the current level in the zigzag-based nanoribbon devices is ∼10 times higher than the armchair devices, while the peak-to-valley ratio is more pronounced in the armchair-based nanoribbon devices. It is also noted that defects increase the current level in the zigzag devices while they lead to multiple NDR peaks with rather negligible change in the current level in the armchair devices. Our results on the defective ZrSe2 structures, as opposed to the pristine ones that are previously studied, provide insight into ZrSe2 material and device properties as a promising nanomaterial for spintronics applications and can be considered as practical guidance to experimental work.
Pressure tuning reverse martensitic transformation in the Mn0.9Co0.1NiGe half-Heusler alloy
Authors: Alves Dos Santos Edileide , França Jessica Kamily Pereira , Dos Santos Adenilson Oliveira , Nurrieli Andira , Do Carmo Danusa , Dos Reis Ricardo Donizeth , Moreira da Silva Luzeli
Published: December 2023

Here we investigate the structural properties of the Mn0.9Co0.1NiGe half-Heusler alloys under pressure up to 12 GPa by Synchrotron angle-dispersive x-ray diffraction (XRD). At room temperature and pressure, the compound exhibits only the hexagonal NiIn2-type structure. Lowering the temperature to 100 K at ambient pressure induces an almost complete martensitic phase transformation to the orthorhombic TiNiSi-type structure. With increasing pressure, the stable orthorhombic phase gradually undergoes a reverse martensitic transformation. The hexagonal phase reaches 85% of the sample when applying 12 GPa of pressure at T = 100 K. We further evaluated the bulk modulus of both hexagonal and orthorhombic phases and found similar values (123.1 ± 5.9 GPa for hexagonal and 102.8 ± 4.2 GPa for orthorhombic). Also, we show that the lattice contraction induced is anisotropic. Moreover, the high-pressure hexagonal phase shows a volumetric thermal contraction coefficient α
v ∼ −8.9(1) × 10−5K−1 when temperature increases from 100 to 160 K, evidencing a significant negative thermal expansion (NTE) effect. Overall, our results demonstrate that the reverse martensitic transition presented on Mn0.9Co0.1NiGe induced either by pressure or temperature is related to the anisotropic contraction of the crystalline arrangement, which should also play a crucial role in driving the magnetic phase transitions in this system.
Finite-size effect on quantum percolation in topological insulators
Authors: Chen Rui , Hua Chun-Bo , Sun Hai-Peng , Zhou Bin
Published: December 2023

We study the finite-size effect on quantum percolation in two-dimensional topological insulators. We demonstrate that the percolation threshold in topological insulators strongly depends on the localization length of the edge states in small clusters due to the finite-size effect. Also, we explain why the percolation threshold in the corresponding classical model determines the lower bound of the quantum percolation threshold in topological insulators. In addition, we extend the percolation model to a more general scenario, where the system is composed of both topological and trivial clusters. We find that the quantum percolation threshold can be less than the classical percolation threshold due to quantum tunneling of the edge states.
Time-resolved heat flux determination from fast-responding temperature-sensitive paint measurement in a shock tunnel using transient in-situ calibration
Authors: Liu Xu , Zhuang Yu , Zhang Yanheng , Wang Gang , Liu Yingzheng , Peng Di
Published: December 2023

Measurement of the global heat flux using fast-responding temperature-sensitive paint (fast TSP) in a shock tunnel is crucial to understanding complex aerothermal effects, but its accuracy is limited by the simplified inverse algorithm as well as the uncertainty in the thermal properties and the thickness of the TSP. In the present work, an in-situ transient calibration method is proposed to determine important parameters in one-dimensional double-layer semi-infinite heat conduction for TSP measurement via heat flux gauges. A fast-converging iterative scheme based on the Levenberg–Marquardt algorithm is used to search for the optimal parameters that minimize the difference between the transient experimental and simulated temperature histories. Furthermore, the heat flux history is determined using the impulse method according to the calibrated parameters. A fast-TSP measurement of 34° ramp flow was conducted at 75 kHz in a Mach-12.1 shock tunnel to validate the proposed method. The results show that the heat flux histories obtained from the TSP and the heat flux gauge results are in good agreement throughout the test period of 11 ms. Moreover, the use of multiple gauges in the calibration further improves the overall consistency of the heat flux amplitude. The in-situ transient calibration method effectively improves the accuracy of the measurement of time-resolved heat flux with relatively low hardware and computational costs.
Plasmon mediated SERS and photocatalysis enhancement in Au nanoparticle decorated 2D-TiSe2
Authors: Sahoo Utkalika P , Sahu Binaya Kumar , Sahoo Subhashree , Das Bidyadhar , Sahoo Pratap K
Published: December 2023

The combination of 2D materials and noble metallic nanostructure is becoming an attractive research domain for label-free, highly sensitive surface-enhanced Raman spectroscopy (SERS) applications. This study demonstrated photocatalysis degradation and SERS enhancements of organic fluorophore (Rhodamine 6G) on two-dimensional (2D) TiSe2 using Raman spectroscopy. The Au nanoparticles (NPs) were decorated on TiSe2 thin films by thermal annealing at variable temperatures. The selective deposition of Au NPs on the hexagonal TiSe2 nanocrystals increases surface roughness, creating a larger surface area for molecule adsorption. It has been observed that the Au decoration at 250 °C on TiSe2 exhibits efficient detection capabilities for R6G with the Raman intensity enhancement factors of the order of ≈105 along with the significantly improved visible light-induced photodegradation efficiency. The optimized Au NP size creates large electromagnetic hot spots produced by strong plasmon coupling that assists in the charge transfer mechanism among TiSe2, Au NPs, and R6G for enhanced SERS and photocatalysis activities. It has been observed that the intensity of Raman scattering decreases as the Au NP size increases on the TiSe2 material. A possible charge transfer mechanism is proposed with an energy band diagram. The simultaneous measurement of SERS and photocatalytic dye degradation in Au decorated TiSe2 can be used as a sensitive technique for water pollution treatment and biodegradable organic contaminants for the environmental ecosystem.
An influence of temperature jump and Navier’s slip-on hybrid nano fluid flow over a permeable stretching/shrinking sheet with heat transfer and inclined MHD
Authors: Sachhin S M , Mahabaleshwar U S , Huang H-N , Sunden B , Zeidan Dia
Published: December 2023

This research article, explores the influence of an inclined magnetic field on the fluid flow over a permeable stretching/shrinking surface with heat transfer. The study use water as a conventional base fluid, with graphene oxide (GO) and Aluminum oxide (Al2O3) nanoparticles submerged to create a nanofluid, the system of governing nonlinear partial differential equations converted into ordinary differential equations via suitable similarity conversions. This allow for the unique solution for stretching sheet/shrinking sheets to be obtained, along with the corresponding temperature solution in terms of the hypergeometric function, several parameters are included in the investigation and their contribution is graphically explained to examine physical characteristics such as radiation, inclined magnetic field, solution domain, volume fraction parameter, and temperature jump. Increasing the volume fraction and thermal radiation increases the thermal boundary layer, increasing the magnetic field parameter and inverse Darcy number increases the temperature and decays the velocity profile. The present work has many useful applications in engineering, biological and physical sciences, as well as in cleaning engine lubricants and thrust-bearing technologies.
The hemodynamic cardiac profiler volume-time curves and related parameters: an MRI validation study
Authors: Konings Maurits K , Sharkawy Manuella Al , Verwijs Sjoerd M , Bakermans Adrianus J , Visscher Martijn , Hollenkamp Charles L , Veelo Denise P , Jørstad Harald T
Published: December 2023

Background. The hemodynamic cardiac profiler (HCP) is a new, non-invasive, operator-independent screening tool that uses six independent electrode pairs on the frontal thoracic skin, and a low-intensity, patient-safe, high-frequency applied alternating current to measure ventricular volume dynamics during the cardiac cycle for producing ventricular volume-time curves (VTCs). Objective. To validate VTCs from HCP against VTCs from MRI in healthy volunteers. Approach. Left- and right-ventricular VTCs were obtained by HCP and MRI in six healthy participants in supine position. Since HCP is not compatible with MRI, HCP measurements were performed within 20 min before and immediately after MRI, without intermittent fluid intake or release by participants. Intraclass correlation coefficients (ICCs) were calculated to validate HCP-VTC against MRI-VTC and to assess repeatability of HCP measurements before and after MRI. Bland–Altman plots were used to assess agreement between relevant HCP- and MRI-VTC-derived parameters. Precision of HCP’s measurement of VTC-derived parameters was determined for each study participant by calculating the coefficients of variation and repeatability coefficients. Main results. Left- and right-ventricular VTC ICCs between HCP and MRI were >0.8 for all study participants, indicating excellent agreement between HCP-VTCs and MRI-VTCs. Mean (range) ICC of HCP right-ventricular VTC versus MRI right-ventricular VTC was 0.94 (0.88–0.99) and seemed to be slightly higher than the mean ICC of HCP left-ventricular VTC versus MRI-VTC (0.91 (0.80–0.96)). The repeatability coefficient for HCP’s measurement of systolic time (tSys) was 45.0 ms at a mean value of 282.9 ± 26.3 ms. Repeatability of biventricular HCP-VTCs was excellent (ICC 0.96 (0.907–0.995)). Significance. Ventricular volume dynamics measured by HCP-VTCs show excellent agreement with VTCs measured by MRI. Since abnormal tSys is a sign of numerous cardiac diseases, the HCP may potentially be used as a diagnostic screening tool.
Simulation of filamentation dynamics of microwave discharge in nitrogen
Authors: Saifutdinov A , Kustova E
Published: December 2023

The present study deals with numerical simulations of microwave (MW) discharges in nitrogen based on extended fluid-dynamic model. The set of governing equations for non-equilibrium gas-discharge plasma includes conservation equations for species number densities, electron energy density, Poisson equation for the electric field coupled to the multi-temperature Navier–Stokes fluid-dynamic equations taking into account thermal nonequilibrium; the power transmitted from MW radiation to electrons is determined from the Helmholtz equation. The kinetic scheme includes 61 reactions involving neutral molecules and atoms in the ground and electronically excited states, ions and electrons. The set of equations is solved for a two-dimensional problem under conditions of experiments at a pressure of 40 and 50 Torr and different electromagnetic wave frequencies and pulse duration. The dynamics of discharge formation and transition from the diffuse to the filament form is studied. The results are compared with experimental data, and a good agreement is shown for the time larger than 10 µs. The possible reasons for discrepancies at a shorter time are discussed and the effect of small oxygen impurities on the quantitative characteristics of the discharge are evaluated. The presence of a small oxygen impurity and seed electrons in the region of discharge formation yields a better agreement between numerical and experimental data.
Impact of rare earth (La, Pr, Eu) impurities on the perovskite SrTiO3 for efficient photocatalytic activity
Authors: Mjahed M , Bouda H , Salmani E , Zahraouy H Ez , Benyoussef A
Published: December 2023

Owing to the growing demand for environmentally friendly technologies across a wide range of fields, including energy, environment and medicine, photocatalytic materials have gained a lot of interest in recent years. First-principles calculations were used in order to examine a variety of physical characteristics such as electronic density of states, structural, optical, and photocatalytic properties of pristine and rare-earth (RE = La, Pr, Eu) doped SrTiO3. The reported electronic band gap of pristine SrTiO3 is Eg = 3.03 eV, which is reasonably consistent with prior theoretical and experimental studies. On the other hand, related to Sr(1−x)RExTiO3, the obtained energy band gaps are 2.75 eV, 2.80 eV, and 2.90 eV associated with Eu-SrTiO3, Pr-SrTiO3, and La-SrTiO3 respectively. The narrowing of the electronic band gap of the studied systems is due to the incorporation of RE-doped SrTiO3, which greatly enhanced the visible light absorption spectra and photocatalytic properties. Thus, it can be concluded that adding RE elements to this kind of materials, is a suitable choice for optoelectronic and photocatalytic applications.
Magnetic effect and chemical distribution study of LCMNO3 perovskite by photoelectron spectroscopy
Authors: Smari Mourad , Moualhi Youssef , Tong Yongfeng , Mansour Said , Rahmouni Hedi
Published: December 2023

The crystal structure, x-ray photoemission spectroscopy, magnetic characteristics, and magnetocaloric performance of perovskite La0.55Ca0.45Mn0.8Nb0.2O3 (LCMNO) ceramic powder were analyzed. The orthorhombic structure with a Pnma space group was found as the main phase in the as-received compound after the XRD pattern refinement. The mixed-valence states of manganese were detected by x-ray photoemission spectroscopy (XPS). The analysis of the La3d line revealed the complex nature of the lanthanum states. The evaluation of Zero-Field-Cooled and Field-Cooled magnetization performance provided conclusive evidence for the existence of the antiferromagnetic Mn3O4 phase at a temperature of TN = 42 K and the coexistence of CO- AFM and FM domains in LCMNO. Despite the observed significant (δTFWHM) value due to relatively low magnetic entropy change (ΔSM), the relative cooling power (RCP) is relatively moderate. By adding Nb4+, the changes in Mn valences and their effect on the magnetic cooling effect are lessened.
Tunable wide spacing all-fiber dual-wavelength holmium-doped fiber laser using a Lyot filter operating above 2 µm
Authors: Ahmad H , Chiam J W , Samion M Z , Zaini M K A , Zulkifli M Z , Thambiratnam K
Published: December 2023

In this work, we successfully demonstrated an all-fiber, dual-wavelength holmium-doped fiber laser (HDFL) with a tunable wavelength spacing range of 8 nm to 24 nm. The HDFL utilizes a Lyot filter to obtain a stable dual wavelength output, with the Lyot filter being constructed from a polarizer, a 20 m polarizing maintaining fiber (PMF) and two polarization controllers (PCs). The dual-wavelength HDFL has an operating wavelength range from 2072.1 nm to 2097.2 nm and a maximum spacing of 24 nm between the lasing wavelengths as well as a signal-to-noise ratio of up to 45 dB and a side mode suppression ratio as low as 0.15 dB. The HDFL is highly stable, with the lasing output have a low power fluctuation of only 2.3 dB over a continuous operation period of 75 min. The proposed HDFL would have substantial applications as a low cost laser source for sensing applications beyond the 2 µm region, particularly those that require a control signal.
Enhancing the capacity of quantum dense coding from correlated amplitude damping channel via non-Hermitian operation
Authors: Leng Yang , Chen Fei
Published: December 2023

Using the non-Hermitian operation approach, we propose a scheme to protect and enhance quantum dense coding from correlated amplitude damping (AD) decoherence. In contrast to the results of memoryless AD channel, we show that the memory effects play a significant role in the suppression of quantum dense coding sudden death. Moreover, we find that the damaged quantum dense coding can be effectively enhanced by using the non-Hermitian operation. Furthermore, the freezing phenomenon of quantum dense coding can be detected by using the optimal non-Hermitian operation.
Spin gap in quasi-one-dimensional S = 3/2 antiferromagnet CoTi2O5
Authors: Xu 徐 Hao-Hang 浩航 , Liu 刘 Qing-Yuan 庆元 , Xin 辛 Chao 潮 , Shen 申 Qin-Xin 沁鑫 , Luo 罗 Jun 军 , Zhou 周 Rui 睿 , Cheng 程 Jin-Guang 金光 , Liu 刘 Jian 健 , Tao 陶 Ling Ling 玲玲 , Liu 刘 Zhi-Guo 志国 , Huo 霍 Ming-Xue 明学 , Wang 王 Xian-Jie 先杰 , Sui 隋 Yu 郁
Published: December 2023

Quasi-one-dimensional (1D) antiferromagnets are known to display intriguing phenomena especially when there is a spin gap in their spin-excitation spectra. Here we demonstrate that a spin gap exists in the quasi-1D Heisenberg antiferromagnet CoTi2O5 with highly ordered Co2+/Ti4+ occupation, in which the Co2+ ions with S = 3/2 form a 1D spin chain along the a-axis. CoTi2O5 undergoes an antiferromagnetic transition at T
N ∼ 24 K and exhibits obvious anisotropic magnetic susceptibility even in the paramagnetic region. Although a gapless magnetic ground state is usually expected in a quasi-1D Heisenberg antiferromagnet with half-integer spins, by analyzing the specific heat, the thermal conductivity, and the spin-lattice relaxation rate (1/T
1) as a function of temperature, we found that a spin gap is opened in the spin-excitation spectrum of CoTi2O5 around T
N, manifested by the rapid decrease of magnetic specific heat to zero, the double-peak characteristic in thermal conductivity, and the exponential decay of 1/T
1 below T
N. Both the magnetic measurements and the first-principles calculations results indicate that there is spin-orbit coupling in CoTi2O5, which induces the magnetic anisotropy in CoTi2O5, and then opens the spin gap at low temperature.
Recommendations for the future regulation of fusion power plants
Authors: Elbez-Uzan J. , Williams L. , Forbes S. , Dodaro A. , Stieglitz R. , Airila M.I. , Holden J. , Rosanvallon S.
Published: December 2023

The discussion in the international community on how fusion power plants (FPPs) will be licenced and regulated is ongoing. As such, there is a concerted drive from the European stakeholders to understand the requirements from such a framework and how to best establish it with the aim of easing the licensing process of FPPs. Initiated by the EUROfusion consortium, a group of European experts were convened to produce a set of recommendations on the regulatory framework for the safety and licensing of FPPs. To do so effectively, the group assessed lessons learned from existing fusion facilities, reports by International Atomic Energy Agency and European Commission on FPP safety and the on-going work by the UK government, US Nuclear Regulatory Commission and Canadian Nuclear Safety Commission, as well as the licensing process of ITER. As a result, commonalities between fusion and fission were identified in terms of fundamental safety objectives which could facilitate parity in certain framework aspects. However, significant differences to any such implementation were also identified, particularly with respect to the lower hazard potential inherent to FPPs and how to remain proportionate to the associated safety challenges and the physical principles behind these two types of reactors together with their associated technologies. The recognition of the differences in the safety challenges in FPPs and fission-based nuclear power plants (NPPs) is paramount to future regulatory framework development. Ultimately, regulatory frameworks depend upon a country’s legal framework, therefore it is apparent that a common global regulatory framework for FPPs is not possible. However, as with present-day NPP regulation, efforts could be made to develop harmonised approaches to FPP regulation to provide common levels of protection. In view of this objective, 12 recommendations are presented across 4 topics: regulations, international databases, codes and standards, safety demonstration rules and regulatory approaches. These recommendations are provided to inform and advise potential future actions on FPP regulatory framework and licencing process principles.
Poloidal localization of the explosive onset of edge localized modes
Authors: Trier E. , Hennequin P. , Maraschek M. , Giannone L. , Vanovac B. ,   the ASDEX Upgrade Team
Published: December 2023

In ASDEX Upgrade lower single null H-mode plasmas, the onset of the explosive phase of Edge Localized Modes (ELMs) is poloidally localized in the X-point/outer strike point (X/OSP) region. From this location, ELMs develop on average towards the low-field and high-field sides in typically

100

μ
s

. An associated magnetic activity localized in the X/OSP region is also observed in-between ELMs, at a lower level than at the ELM onset, and interpreted as being due to perturbed currents connected to the divertor target-s. Its broadband spectra typically extend up to

100

k
H
z

–due to short-lived events of variable frequencies–and are dominated by

n

=
1

toroidal mode numbers rotating in the counter-current direction.
Short-time large deviations of the spatially averaged height of a Kardar–Parisi–Zhang interface on a ring
Authors: Schorlepp Timo , Sasorov Pavel , Meerson Baruch
Published: December 2023

Using the optimal fluctuation method, we evaluate the short-time probability distribution

P
(

H
ˉ

,
L
,
t
=
T
)

of the spatially averaged height

H
ˉ

=
(
1

/

L
)

∫
0
L

h
(
x
,
t
=
T
)

d

x

of a one-dimensional interface

h
(
x
,
t
)

governed by the Kardar–Parisi–Zhang equation

∂
t

h
=
ν

∂
x
2

h
+

λ
2

∂
x

h

2

+

D

ξ

x
,
t

on a ring of length L. The process starts from a flat interface,

h
(
x
,
t
=
0
)
=
0

. Both at

λ

H
ˉ

<
0

and at sufficiently small positive

λ

H
ˉ

the optimal (that is, the least-action) path

h
(
x
,
t
)

of the interface, conditioned on

H
ˉ

, is uniform in space, and the distribution

P
(

H
ˉ

,
L
,
T
)

is Gaussian. However, at sufficiently large

λ

H
ˉ

>
0

the spatially uniform solution becomes sub-optimal and gives way to non-uniform optimal paths. We study these, and the resulting non-Gaussian distribution

P
(

H
ˉ

,
L
,
T
)

, analytically and numerically. The loss of optimality of the uniform solution occurs via a dynamical phase transition of either first or second order, depending on the rescaled system size

ℓ
=
L

/

ν
T

, at a critical value

H
ˉ

=

H
ˉ

c

(
ℓ
)

. At large but finite

ℓ

the transition is of first order. Remarkably, it becomes an ‘accidental’ second-order transition in the limit of

ℓ
→
∞

, where a large-deviation behavior

−
ln
P
(

H
¯

,
L
,
T
)
≃
(
L
/
T
)
f
(

H
¯

)

(in the units

λ
=
ν
=
D
=
1

) is observed. At small

ℓ

the transition is of second order, while at

ℓ
=
O
(
1
)

transitions of both types occur.
Empirical projection of global sea level in 2050 driven by Antarctic and Greenland ice mass variations
Authors: Lee Donghyuck , Kim Byeong-Hoon , Seo Ki-Weon , Lee Won Sang , Lee Choon-Ki , Jeon Taehwan , Jin Emilia Kyung
Published: December 2023

Global mean sea level rise, driven by ice mass loss in Antarctic and Greenland Ice Sheets (AIS and GrIS), is a significant consequence of global warming. Although various ice sheet models have attempted to predict the ice mass balance and subsequent sea level changes, non-trivial disagreements between models exist. In this study, we employ an empirical approach to estimate the future (2050) ice mass changes for both ice sheets, assuming their historical patterns of ice dynamics would persist in the coming decades. To achieve this, we estimate decadal-scale ice discharge variations by subtracting the surface mass balance (SMB) from the observed ice mass changes and extrapolate linear trend and acceleration components of ice discharges up to 2050. We also consider future SMB data from Coupled Model Intercomparison Project phase 6 models to estimate net ice mass balance. Our estimates suggest that from 2021 to 2050, the global sea level rise due to AIS and GrIS ranges between 6–19 mm and 15–31 mm, respectively. Additionally, we investigate regional sea level variability resulting from geoid changes induced by ice mass changes in both regions, highlighting that heterogeneous sea level changes may cause more pronounced sea level rises in lower latitude regions, where major cities are located.
Domain wall fluctuations of the six-vertex model at the ice point
Authors: Prähofer Michael , Spohn Herbert
Published: December 2023

We report on Monte-Carlo simulations of the six-vertex model with domain wall boundary conditions. In thermal equilibrium such boundary conditions force a fluctuating line separating the disordered region from the perfectly ordered ones. Specifically we study the ice point at which all vertex weights are equal. With high precision the one-point fluctuations of the line are confirmed to be of order

N

1
3

and governed by the Tracy–Widom distribution. Furthermore, the non-universal scaling coefficients are computed for a wide range of interaction strengths.
Magnetic field influence on the light yield from fiber-coupled BCF-60 plastic scintillators of relevance for output factor dosimetry in MR-linacs
Authors: Andersen Claus E
Published: December 2023

Organic plastic scintillators are of interest for ionizing radiation dosimetry in megavoltage photon beams because plastic scintillators have a mass density very similar to that of water. This leads to insignificant perturbation of the electron fluence at the point of measurement in a water phantom. This feature is a benefit for dosimetry in strong magnetic fields (e.g., 1.5 T) as found in linacs with magnetic resonance imaging. The objective of this work was to quantify if the light yield per dose for the scintillating fiber BCF-60 material from Saint-Gobain Ceramics and Plastics Inc. is constant regardless of the magnetic flux density. This question is of importance for establishing traceable measurement in MR linacs using this detector type. Experiments were carried out using an accelerator combined with an electromagnet (max 0.7 T). Scintillator probes were read out using chromatic stem-removal techniques based on two optical channels or full spectral information. Reference dosimetry was carried out with PTW31010 and PTW31021 ionization chambers. TOPAS/GEANT4 was used for modelling. The light yield per dose for the BCF-60 was found to be strongly influenced by the magnitude of the magnetic field from about 1 mT to 0.7 T. The light yield per dose increased (1.3 ± 0.2)% (k = 1) from 1 mT to 10 mT and it increased (4.5 ± 0.9)% (k = 1) from 0 T to 0.7 T. Previous studies of the influence of magnetic fields on medical scintillator dosimetry have been unable to clearly identify if observed changes in scintillator response with magnetic field strength were related to changes in dose, stem signal removal, or scintillator light yield. In the current study of BCF-60, we see a clear change in light yield with magnetic field, and none of the other effects.
Silicone Particles in Capsules Around Breast Implants: An Investigation Into Currently Available Implants in North America
Authors: Danino Michel Alain , Dziubek Melvin , Dalfen Jacqueline , Bonapace-Potvin Michelle , Gaboury Louis , Giot Jean Philippe , Laurent Romain
Published: December 2023

Background

Breast implants have always been composed of a silicone elastomer envelope filled with either silicone gel or saline. Breast implant illness (BII) is a set of symptoms that has previously been linked to the leakage of silicone particles from the implants into the body.

Objectives

Our research aimed to quantify the number of silicone particles present in the capsules of breast implants available in North America.

Methods

Thirty-five periprosthetic capsules were sampled and analyzed, and silicone particles were counted and measured. The capsule surface area was then measured and utilized to calculate particle density and total number of silicone particles.

Results

Eighty-five percent of capsules analyzed from silicone gel implants contained silicone, with an average of 62 particles per mm3 of capsular tissue. These implants had approximately 1 million silicone particles per capsule. In contrast, none of the saline implant capsules contained silicone. Capsules from macrotextured tissue expanders contained fewer and larger silicone particles.

Conclusions

Silicone gel implants presented silicone particle bleeding into the periprosthetic capsule, totaling on average 1 million silicone particles per capsule. On the other hand, no silicone particle bleeding was observed from saline breast implants. These data suggest that particle bleeding comes from the inner silicone gel, and not from the smooth outer silicone shell. Previous studies have reported the presence of breast implant illness in patients with both silicone- and saline-filled implants. Therefore, our data suggest that silicone migration is not the sole cause of BII.

Level of Evidence: 4