bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption mechanism and compatibility of environmentally friendly insulating gas CF3I and its main decomposition products with Al and Cu(1 1 1) surfaces
Authors: Liu Wei , Song Yumei , Guo Yuzheng , Han Rong , Zheng Yu
Published: January 2024

Good environmental compatibility and excellent insulation performance make trifluoroiodomethane (CF3I) have the potential to replace SF6 in gas-insulated equipment. The gas–solid compatibility of CF3I, its main decomposed products (I2, C2F6, C3F8, C2F4, HF, CF3H, COF2), and environmental molecule H2O with the Al and Cu(111) surfaces is investigated based on first-principles calculations. The most stable adsorption configurations of Al and Cu(111) surfaces adsorbed by all gas molecules are constructed, and the interaction types between gas molecules and two metal surfaces are determined by adsorption energy (E
ad), charge transfer, and charge density difference. The absolute E
ad of CF3I and I2 adsorbed on Al(111) surfaces are 4.09 and 3.76 eV, respectively. In contrast, the absolute E
ad of other gases adsorbed on Al(111) surfaces do not exceed 0.99 eV, indicating that CF3I and I2 have strong chemical interactions and poor gas–solid compatibility with Al(111) surfaces, while other gases exhibit good gas–solid compatibility with the Al surface. The absolute E
ad of I2 (1.15 eV) adsorbed on Cu(111) surface is significantly larger than that of other gases-adsorbed systems (not exceeding 0.99 eV) including CF3I-adsorbed system, proving that the gas–solid compatibility of I2 with Cu(111) surfaces is worse than that of other gases. In addition, the reasons for the different compatibility of CF3I with Al and Cu(111) surfaces are analyzed in depth through the density of states.
AdaClass filter and its application in bearing fault diagnosis
Authors: Zhang Hanyu , Li Yuntao , Zhang Xin , Zhang Zitong , Jiang Yanan
Published: January 2024

The vibration signals recorded by the sensor reflect the operating state of bearings, and extracting recognizable features effectively from them has become a hot issue in fault diagnosis. Currently, signal processing based filtering methods have emerged as a popular approach for extracting fault-related features. However, conventional filters based on specified assumptions and theoretical models have limited adaptability to multiple types of bearings under different operating conditions, which can significantly impact the diagnostic results. Given this, a data-driven Adaptive Class (AdaClass) filter is proposed to extract the response characteristics of different categories within the latent space. The filter details are obtained by statistically analyzing the mean vectors of samples for each class in the reconstructed feature subspaces. Notably, the latent feature space is mapped by linear operators linear discriminant analysis and class-wise principal component analysis, where the data has a more concise feature representation and a more distinct feature structure. The low-dimensional projection operations enhance the differential information among different categories, and reorganize the internal structure within the same category. Furthermore, a bearing fault diagnosis model is developed based on the AdaClass filter banks, utilizing one-step convolution to improve the efficiency of feature extraction. Experimental results show that the proposed method outperforms the competitors in terms of accuracy, time consumption, and noise resistance, especially for small sample scenarios.
Transition from fractal-dendritic to compact islands for the 2D-ferroelectric SnSe on graphene/Ir(111)
Authors: Aleksa P , Ghorbani-Asl M , Iqbal S , Martuza M A , Bremerich A , Wilks D , Cai J , Chagas T , Ohmann R , Krasheninnikov A , Busse C
Published: January 2024

Epitaxial growth is a versatile method to prepare two-dimensional van der Waals ferroelectrics like group IV monochalcogenides which have potential for novel electronic devices and sensors. We systematically study SnSe monolayer islands grown by molecular beam epitaxy, especially the effect of annealing temperature on shape and morphology of the edges. Characterization of the samples by scanning tunneling microscopy reveals that the shape of the islands changes from fractal-dendritic after deposition at room temperature to a compact rhombic shape through annealing, but ripening processes are absent up to the desorption temperature. A two-step growth process leads to large, epitaxially aligned rhombic islands bounded by well-defined

110

-edges (armchair-like), which we claim to be the equilibrium shape of the stoichiometric SnSe monolayer islands. The relaxation of the energetically favorable edges is detected in atomically resolved STM images. The experimental findings are supported by the results of our first-principles calculations, which provide insights into the energetics of the edges, their reconstructions, and yields the equilibrium shapes of the islands which are in good agreement with the experiment.
Fabrication of high quality lead-free double perovskite Cs2AgBiBr6 thin film and its application in memristor with ultralow operation voltage
Authors: Zhang Xiaofang , Wang Ke , Li Zhenyu , Qi Juanjuan , Li Dongke , Luo Jianqiang , Liu Jian
Published: January 2024

Recently, the lead-free double perovskite Cs2AgBiBr6 has been considered as a promising candidate for next-generation nonvolatile memory and artificial synapse devices due to its high stability and low toxicity compared to its lead-based counterparts. In this work, we developed a simple and effective method to produce high-quality lead-free double perovskite Cs2AgBiBr6 thin films without pinholes and particles by applying a low-pressure assisted method under ambient condition with a relative humidity (RH) of about 45%. The formation of pinholes and Ag precipitation in the perovskite Cs2AgBiBr6 films is effectively suppressed by the proper ratio of N,N-dimenthylformamide (DMF) mixed in dimethyl sulfoxide (DMSO) solvents. Furthermore, the grain size of the Cs2AgBiBr6 films can be significantly increased by increasing the post-annealing temperature. Finally, a sandwiched structure memristor with an ITO/Cs2AgBiBr6/Ta configuration was successfully demonstrated, featuring ultralow operation voltage (V
Set ∼ 57 ± 23 mV, V
Reset ∼ −692 ± 68 mV) and satisfactory memory window (the ratio of R
HRS/R
LRS ∼ 10 times), which makes it suitable for low-power consumption information storage devices.
Blowup analysis for a quasi-exact 1D model of 3D Euler and Navier–Stokes
Authors: Hou Thomas Y , Wang Yixuan
Published: January 2024

We study the singularity formation of a quasi-exact 1D model proposed by Hou and Li (2008 Commun. Pure Appl. Math.
61 661–97). This model is based on an approximation of the axisymmetric Navier–Stokes equations in the r direction. The solution of the 1D model can be used to construct an exact solution of the original 3D Euler and Navier–Stokes equations if the initial angular velocity, angular vorticity, and angular stream function are linear in r. This model shares many intrinsic properties similar to those of the 3D Euler and Navier–Stokes equations. It captures the competition between advection and vortex stretching as in the 1D De Gregorio (De Gregorio 1990 J. Stat. Phys.
59 1251–63; De Gregorio 1996 Math. Methods Appl. Sci.
19 1233–55) model. We show that the inviscid model with weakened advection and smooth initial data or the original 1D model with Hölder continuous data develops a self-similar blowup. We also show that the viscous model with weakened advection and smooth initial data develops a finite time blowup. To obtain sharp estimates for the nonlocal terms, we perform an exact computation for the low-frequency Fourier modes and extract damping in leading order estimates for the high-frequency modes using singularly weighted norms in the energy estimates. The analysis for the viscous case is more subtle since the viscous terms produce some instability if we just use singular weights. We establish the blowup analysis for the viscous model by carefully designing an energy norm that combines a singularly weighted energy norm and a sum of high-order Sobolev norms.
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

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

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

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

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

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

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

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.
Evolutionary game dynamics of combining two different aspiration-driven update rules in structured populations
Authors: Yang 杨 Zhi-Hao 智昊 , Yang 杨 Yan-Long 彦龙
Published: January 2024

In evolutionary games, most studies on finite populations have focused on a single updating mechanism. However, given the differences in individual cognition, individuals may change their strategies according to different updating mechanisms. For this reason, we consider two different aspiration-driven updating mechanisms in structured populations: satisfied-stay unsatisfied shift (SSUS) and satisfied-cooperate unsatisfied defect (SCUD). To simulate the game player’s learning process, this paper improves the particle swarm optimization algorithm, which will be used to simulate the game player’s strategy selection, i.e., population particle swarm optimization (PPSO) algorithms. We find that in the prisoner’s dilemma, the conditions that SSUS facilitates the evolution of cooperation do not enable cooperation to emerge. In contrast, SCUD conditions that promote the evolution of cooperation enable cooperation to emerge. In addition, the invasion of SCUD individuals helps promote cooperation among SSUS individuals. Simulated by the PPSO algorithm, the theoretical approximation results are found to be consistent with the trend of change in the simulation results.
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

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

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

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

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

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

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

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

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°.
The carbon footprint of future engineered wood construction in Montreal
Authors: Meyer Felicity , Elliot Thomas , Craig Salmaan , Goldstein Benjamin P
Published: January 2024

Engineered wood (EW) has the potential to reduce global carbon emissions from the building sector by substituting carbon-intensive concrete and steel for carbon-sequestering wood. However, studies accounting for material use and embodied carbon in buildings rarely analyse the city-scale or capture connections between the city and supplying hinterlands. This limits our knowledge of the effectiveness of decarbonising cities using EW and its potential adverse effects, such as deforestation. We address this gap by combining bottom-up material accounting of construction materials with life cycle assessment to analyse the carbon emissions and land occupation from future residential construction in Montreal, Canada. We compare material demand and environmental impacts of recent construction using concrete and steel to future construction using EW at the neighbourhood, urban scales under high- and low-density growth scenarios. We estimate that baseline embodied carbon per capita across the Agglomeration of Montreal is 3.2 tonnes per carbon dioxide equivalents (CO2eq.), but this ranges from 8.2 tonnes CO2eq. per capita in areas with large single-family housing to 2.0 tonnes CO2eq. per capita where smaller homes predominate. A Montreal-wide transition to EW may increase carbon footprint by up to 25% under certain scenarios, but this varies widely across the city and is tempered through urban densification. Likewise, a transition to EW results in less than 0.1% land transformation across Quebec’s timbershed. Moreover, sustainable logging practices that sequester carbon can actually produce a carbon-negative building stock in the future if carbon in the wood is not re-emitted when buildings are demolished or repurposed. To decarbonise future residential construction, Montreal should enact policies to simultaneously promote EW and denser settlement patterns in future construction and work with construction firms to ensure they source timber sustainably.
A stepped-wedge randomised controlled trial to assess efficacy and cost-effectiveness of a care-bundle to prevent falls in older hospitalised patients
Authors: Di Gennaro Gianfranco , Chamitava Liliya , Pertile Paolo , Ambrosi Elisa , Mosci Daniela , Fila Alice , Alemayohu Mulubirhan Assefa , Cazzoletti Lucia , Tardivo Stefano , Zanolin Maria Elisabetta
Published: January 2024

Background

Patient accidental falls in a hospital environment are a serious problem for patient safety, and for the additional costs due to associated medical interventions.

Objective

The endpoints of this study were the assessment of the fall incidence in the hospital before and after the implementation of a multidisciplinary care-bundle, along with a cost-effectiveness evaluation.

Design

A stepped-wedge trial was conducted between April 2015 and December 2016 in Bologna University Hospital.

Methods

Incidence rates (IRs) of falls in both the control and intervention periods were calculated. A multilevel mixed-effects generalised linear model with logit link function, adjusted for age, sex, cluster cross-over timing and patients’ clinical severity was used to estimate odds ratios (OR) of fall risk of patients of the intervention group respect to the controls.

Intervention costs associated with the introduction of the care-bundle intervention were spread between patients per cluster-period-group of exposure. Incremental cost-effectiveness ratio was evaluated using total costs in the intervention and control groups.

Results

IRs of falls in control and intervention periods were respectively 3.15 and 2.58 for 1,000 bed-days. After adjustment, the subjects receiving the intervention had a statistically significant reduced risk of falling with respect to those who did not (OR = 0.71, 95% confidence interval: 0.60–0.84). According to the cost-effectiveness analysis, the incremental cost per fall prevented was €873.92 considering all costs, and €1644.45 excluding costs related falls.

Conclusions

Care-bundle had a protective effect on patients, with a statistically significant reduction of the fall risk. This type of intervention appears cost-effective compared to routine practices.
Implementation and impact of the World Health Organization integrated care for older people (ICOPE) program in China: a randomised controlled trial
Authors: Yan Wang Ninie , Liu Xiaohong , Kong Xiangrong , Sumi Yuka , Chhetri Jagadish K , Hu Linlin , Zhu Minglei , Kang Lin , Liang Zhen , Ellis John W , Shi Leiyu
Published: January 2024

Background

Fragmentation of services increases health and social care burden as people live longer with higher prevalence of diseases, frailty and dependency. Local evidence for implementing person-centred integrated care is urgently needed to advance practice and policies to achieve healthy ageing.

Objective

To test the feasibility and impact of World Health Organization's (WHO) Integrated Care for Older People (ICOPE) approach in China.

Design

A randomised controlled trial examining the feasibility of implementing ICOPE approach, evaluating its impact on health outcomes and health resource utilisation.

Setting

Primary care setting in urban and suburban communities of Chaoyang District, Beijing, China.

Subjects

Community-dwelling older adults screened as at-risk of functional declines and randomised into intervention (537) and control (1611) groups between September 2020 and February 2021.

Methods

A 6-month intervention program following WHO's ICOPE care pathways implemented by integrated care managers compared to standard available care.

Results

After 1 to 1 propensity score matching, participants in intervention and control groups (totally 938) had comparable baseline characteristics, demonstrated feasibility of implementing ICOPE with satisfaction by participants (97–99%) and providers (92–93%). All outcomes showed improvements after a 6-month intervention, while statistically significant least-squares mean differences (control-intervention) in vitality (Mini-Nutritional Assessment Short Form to measure vitality, −0.21, 95% CI, −0.40–0.02), mobility (Short Physical Performance Battery to measure mobility, −0.29, 95% CI, −0.44–0.14) and psychological health (Geriatric Depression Scale five items to measure psychological health, 0.09, 95% CI, 0.03–0.14) were observed (P < 0.05).

Conclusions

It is feasible to localise and implement WHO’s ICOPE approach in regions with fragmented resources such as China. Preliminary evidence supports its acceptance among key stakeholders and impact on health outcomes.
Why to test for dementia: perspectives of patients, significant others and general practitioners
Authors: Linden Iris , Wolfs Claire , Hevink Maud , Dirksen Carmen , Ponds Rudolf , Perry Marieke
Published: January 2024

Background

This study aims to provide greater insight into the current decision-making process on diagnostic testing for dementia by exploring the expectations, needs and experiences of patients with memory complaints, significant others and general practitioners (GPs).

Methods

We performed semi-structured interviews with patients (>60 years) who consulted their GP on memory complaints, significant others and GPs. Participants were recruited until data saturation was reached in thematic analysis of interview transcripts.

Results

We performed 51 interviews (patients n = 20, significant others n = 15, GPs n = 16). Thematic analysis revealed four themes: (i) ‘drivers to (not) testing’, i.e. need to act on symptoms, beliefs on the necessity and expected outcomes of diagnostic testing; (ii) ‘patient preferences and context are critical in the actual decision’, i.e. in the actual decision-making process interpretation of symptoms, GPs’ desire to meet patient preferences, social context and healthcare system dynamics guided the decision; (iii) ‘need for individualised communication in the decision-making process’, i.e. for patients feeling heard was a prerequisite for decision-making and GPs tailored communication strategies to individual patients and (iv) ‘GP practice and barriers to shared decision-making (SDM)’, i.e. although GPs value SDM in the decision on diagnostic testing for dementia, patients express limited awareness of the decision and options at stake.

Conclusions

Decision-making on diagnostic testing for dementia is a multifactorial and preference-guided process for all involved stakeholders, but decisions are often not explicitly jointly made. Development of patient decision aids could facilitate better involvement and more informed choices by patients.
Diagnostic test accuracy of serum creatinine and cystatin C-based index for sarcopenia: a systematic review and meta-analysis
Authors: Lin Taiping , Jiang Tingting , Huang Xiaotao , Xu Ping , Liang Rui , Song Quhong , Tu Xiangping , Zhao Yanli , Huang Li , Yue Jirong , Wu Chenkai
Published: January 2024

Background

Sarcopenia is an important prognostic factor, but its optimal screening methods remain challenging. Several new indices developed based on serum creatinine (Cr) and cystatin C (CysC) have been proposed to be diagnostic biomarkers for sarcopenia screening.

Objective

This review aimed to evaluate the diagnostic accuracy of serum Cr- and CysC-based indices for sarcopenia diagnosis.

Methods

We systematically searched MEDLINE, EMBASE, SCIE and SCOPUS from inception to 2 April 2023. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. A bivariate random-effects model was used to synthesise the pooled sensitivity, specificity and area under the curves of the summary receiver operating characteristic (SROC-AUC).

Results

We retrieved 936 publications and included 16 studies with 5,566 participants (mean age ranged: 51.0–78.4 years, 50.2% men). The prevalence of sarcopenia ranged from 7.8 to 69.5%. All included studies presented a moderate to high risk of bias. The serum Cr- and CysC-based indices showed moderate diagnostic accuracy for sarcopenia (pooled sensitivity: 0.67, 95% CI 0.57–0.75; pooled specificity: 076, 95% CI 0.67–0.83; pooled SROC-AUC: 0.78, 95% CI 0.74–0.81). The Cr/CysC ratio is the most widely studied index, followed by the Cr × eGFRcys index. Overall, both indicators had satisfactory and comparable performance in screening sarcopenia.

Conclusion

Serum Cr- and CysC-based indices showed moderate diagnostic accuracy for sarcopenia. The most studied indices—the Cr/CysC ratio and Cr × eGFRcys index—had comparable diagnostic accuracy for evaluating sarcopenia and may serve as surrogate markers for sarcopenia. However, further validation is required to verify these findings.
Flowering time responses to warming drive reproductive fitness in a changing Arctic
Authors: Collins Courtney G , Angert Amy L , Clark Karin , Elmendorf Sarah C , Elphinstone Cassandra , Henry Greg H R
Published: January 2024

Background and Aims

The Arctic is warming at an alarming rate, leading to earlier spring conditions and plant phenology. It is often unclear to what degree changes in reproductive fitness (flower, fruit and seed production) are a direct response to warming versus an indirect response through shifting phenology. The aim of this study was to quantify the relative importance of these direct and indirect pathways and project the net effects of warming on plant phenology and reproductive fitness under current and future climate scenarios.

Methods

We used two long-term datasets on 12 tundra species in the Canadian Arctic as part of the International Tundra Experiment (ITEX). Phenology and reproductive fitness were recorded annually on tagged individual plants at both Daring Lake, Northwest Territories (64° 52' N, - 111° 35' W) and Alexandra Fiord, Nunavut (78° 49' N, - 75° 48' W). The plant species encompassed a wide taxonomic diversity across a range of plant functional types with circumpolar/boreal distributions. We used hierarchical Bayesian structural equation models to compare the direct and indirect effects of climate warming on phenology and reproductive fitness across species, sites and years.

Key Results

We found that warming, both experimental and ambient, drove earlier flowering across species, which led to higher numbers of flowers and fruits produced, reflecting directional phenotypic selection for earlier flowering phenology. Furthermore, this indirect effect of climate warming mediated through phenology was generally about two to three times stronger than the direct effect of climate on reproductive fitness. Under future climate predictions, individual plants showed a ~2- to 4.5-fold increase in their reproductive fitness (flower counts) with advanced flowering phenology.

Conclusions

Our results suggest that, on average, the benefits of early flowering, such as increased development time and subsequent enhanced reproductive fitness, might outweigh its risks. Overall, this work provides important insights into population-level consequences of phenological shifts in a warming Arctic over multi-decadal time scales.
Do patients benefit from omega-3 fatty acids?
Authors: Sherratt Samuel C R , Mason R Preston , Libby Peter , Steg Ph Gabriel , Bhatt Deepak L
Published: January 2024

Omega-3 fatty acids (O3FAs) possess beneficial properties for cardiovascular (CV) health and elevated O3FA levels are associated with lower incident risk for CV disease (CVD.) Yet, treatment of at-risk patients with various O3FA formulations has produced disparate results in large, well-controlled and well-conducted clinical trials. Prescription formulations and fish oil supplements containing low-dose mixtures of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have routinely failed to prevent CV events in primary and secondary prevention settings when added to contemporary care, as shown most recently in the STRENGTH and OMEMI trials. However, as observed in JELIS, REDUCE-IT, and RESPECT-EPA, EPA-only formulations significantly reduce CVD events in high-risk patients. The CV mechanism of action of EPA, while certainly multifaceted, does not depend solely on reductions of circulating lipids, including triglycerides (TG) and LDL, and event reduction appears related to achieved EPA levels suggesting that the particular chemical and biological properties of EPA, as compared to DHA and other O3FAs, may contribute to its distinct clinical efficacy. In vitro and in vivo studies have shown different effects of EPA compared with DHA alone or EPA/DHA combination treatments, on atherosclerotic plaque morphology, LDL and membrane oxidation, cholesterol distribution, membrane lipid dynamics, glucose homeostasis, endothelial function, and downstream lipid metabolite function. These findings indicate that prescription-grade, EPA-only formulations provide greater benefit than other O3FAs formulations tested. This review summarizes the clinical findings associated with various O3FA formulations, their efficacy in treating CV disease, and their underlying mechanisms of action.