bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Numerical Study on the Influence of Confining Walls on Drag and Heat Transfer Coefficients in Single‐Particle Lab‐Scale Reactors
Authors: Reinold Philipp , Kutscherauer Martin , Wehinger Gregor D. 
Published: October 2024

AbstractSingle‐particle reactors in lab‐scale are a promising technology to gain an in‐depth understanding of the intricate reaction and transport processes that occur in catalyst particles under operando conditions. It is not described whether the effect of the bounding walls in such narrow flow channels influence the processes at the particle. Therefore, this work applies three‐dimensional (3D) computational fluid dynamics (CFD) simulations to analyze the drag coefficient CD alongside the local and average particle Nusselt number Nup as characteristic local and integral quantities in the range of particle Reynolds numbers 10 ≤ Rep ≤ 103. An equation is derived to correct for the wall effects on CD and Nup and assist the experimenter in the interpretation of measured results.
A Survey on Heterogeneous CPU–GPU Architectures and Simulators
Authors: Alaei Mohammad , Yazdanpanah Fahimeh 
Published: October 2024

ABSTRACTHeterogeneous architectures are vastly used in various high performance computing systems from IoT‐based embedded architectures to edge and cloud systems. Although heterogeneous architectures with cooperation of CPUs and GPUs and unified address space are increasingly used, there are still a lot of open questions and challenges regarding the design of these architectures. For evaluation, validation and exploration of next generation of heterogeneous CPU–GPU architectures, it is essential to use unified heterogeneous simulators for analyzing the execution of CPU–GPU workloads. This article presents a systematic review on challenges of heterogeneous CPU–GPU architectures with covering a diverse set of literatures on each challenge. The main considered challenges are shared resource management, network interconnections, task scheduling, energy consumption, and programming model. In addition, in this article, the state‐of‐the‐art of heterogeneous CPU–GPU simulation platforms is reviewed. The structure and characteristics of five cycle‐accurate heterogeneous CPU–GPU simulators are described and compared. We perform comprehensive discussions on the methodologies and challenges of designing high performance heterogeneous architectures. Moreover, for developing efficient heterogeneous CPU–GPU simulators, some recommendations are presented.
A heart model of Earth Stewardship
Authors: Scheffer Marten , Anderies John M. , Bjordam Tone , Bollen Johan , Carpenter Stephen R. , Chapin F. Stuart , Folke Carl , Gazitua Francisco , Holmgren Milena , Marcone Jorge , Polasky Steve , Weber Elke , Westley Frances 
Published: October 2024

AbstractFew disagree that we should pass on the Earth in good shape to future generations, and many scientists want their work to contribute to that goal. Recent work has shown that hopelessness stands in the way of people taking an active attitude. At the same time, it is becoming clear what can be done about that: providing compelling visions of attractive futures and highlighting feasible pathways. Currently, science and the humanities are not well designed for this task. Practices that stand in the way of a more holistic change‐making approach include proposal‐based funding, paralyzing rigor requirements, and a focus on explanation rather than action. Removing those barriers may require culture shifts, a notoriously difficult and slow kind of change. Meanwhile, realistic inspiring future scenarios can be developed by bringing diverse thinkers together in environments where time, space, and immediate outcomes are not pressing.
Construction of Spiro Systems from Tetrathiafulvalene Derivatives by a Pinacol‐Like Rearrangement
Authors: Wang Jie , Zhang Shangxi , Zhang Hui , Zheng Yuanyuan , Liang Lina , Liu Lei 
Published: October 2024

AbstractAn efficient and generalized pinacol‐like rearrangement of tetrathiafulvalene (TTF) derivatives has been achieved using 2, 2, 6, 6‐tetramethylpiperidine oxide (TEMPO) as a key reagent, in place of a traditional metal catalyst. Examination of numerous TTF derivatives demonstrates the reaction's exceptional tolerance to a variety of substituents, achieving an overall yield of up to 97 %. The optimization of reaction conditions and evaluation of reaction applicability were achieved by varying factors such as the first redox potentials (E11/2) of the substrate molecule, substituent type, substituent position, number of substituents, and structural symmetry. Additionally, the reaction mechanism was explored using isotopic labeling, real‐time monitoring UV‐Vis absorption spectroscopy, and X‐ray diffraction (XRD) analysis. Specifically, TTF is oxidized to TTF+⋅ by p‐toluenesulfonic acid (TsOH⋅H2O). TTF+⋅ subsequently reacts with TEMPO and H2O to form a pinacol‐like intermediate, which undergoes a rearrangement to release a 2, 2, 6, 6‐tetramethylpiperidin‐1‐ol (TEMPOH) molecule, forming the rearranged product as a hydrogenated cation, this intermediate undergoes deprotonation, leading to the formation of the final spiro product. This investigation led to the identification of a class of reactions for the efficient conversion of TTF derivatives into their spiro products via pinacol‐like rearrangement reaction.
Using 5G Standards for Smart Healthcare Applications and Designing an Artificial Intelligence‐Based Industry 4.0 Communication System
Authors: Ozturk Bilal A. , Al‐Jumaili Ahmed Sabah Ahmed , Namiq Heba Emad , Mahajan Hemant B. , Uke Nilesh , Shamaileh Anas Atef , Mohammedqasim Hayder , Mohammedqasem Roa'a 
Published: October 2024

ABSTRACTThe introduction of Industry 4.0, to improve Internet of Things (IoT) standards, has sparked the creation of 5G, or highly sophisticated wireless networks. There are several barriers standing in the way of 5G green communication systems satisfying the expectations for faster networks, more user capacity, lower resource consumption, and cost‐effectiveness. 5G standards implementation would speed up data transmission and increase the reliability of connected devices for Industry 4.0 applications. The demand for intelligent healthcare systems has increased globally as a result of the introduction of the novel COVID‐19. Designing 5G communication systems presents research problems such as optimizing resource usage, managing mobility, ensuring cost‐efficiency, managing interference, and maximizing spectral efficiency. The fast advancement of artificial intelligence (AI) in several domains yields improved performance in contrast to traditional methods. Hence, including AI in 5G standards would enhance performance by catering to diverse end‐user applications. Initially, we provide an overview of concepts such as Industry 4.0, the 5G standard, and recent developments in the sphere of wireless communications in the future. The goal is to use 5G technology to look at current research problems. We present a new architecture for Industry 4.0 and 5G‐compliant smart healthcare systems. We develop and run the proposed model to investigate the current 5G methods using the Network Simulator (NS2). The results of the simulation show that 5G resource management and interference management approaches already in use face challenges including performance trade‐offs.
Comparing Satellite, Reanalysis, Fused and Gridded (In Situ) Precipitation Products Over Türkiye
Authors: Akbas Abdullah , Ozdemir Hasan 
Published: October 2024

ABSTRACTPrecipitation is the fundamental source for various research areas, including hydrology, climatology, geomorphology, and ecology, serving essential roles in modelling, distribution, and process analysis. However, the accuracy and precision of spatially distributed precipitation estimates is a critical issue, particularly for daily scale and topographically complex areas. Although many datasets have been developed based on different algorithms and sources are developed for this purpose, determining which of these datasets best reflects actual conditions is quite challenging. This study, hence, aims to compare the 25 global distributed precipitation estimates (gridded, satellite, model, and fused) concerning 221 ground‐based observations based on the ranking of 18 continuous (evaluation statistics), eight categorical (precipitation indices), and two seasonality metric (high and low precipitation). Upon examining the results, gridded and model precipitation data including APHRODITE (Asian Precipitation—Highly‐Resolved Observational Data Integration Towards Evaluation), CPC (Global Unified Gauge‐Based Analysis of Daily Precipitation), ERA5‐Land (ECMWF Reanalysis 5th Generation for Lands), and CFSR (Climate Forecast System Reanalysis) occupy the top four positions in continuous metrics. In contrast, satellite data such as PERSIANN‐PDIR (Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks), CMORPH (Climate Prediction Center morphing method), IMERG (The Integrated Multi‐Satellite Retrievals for GPM), and TRMM‐TMPA (Tropical Rainfall Measuring Mission/Multi‐satellite Precipitation Analysis) dominate in the top four positions in categorical metrics. For seasonality of high and low precipitation, fused, gridded, and reanalyses products such as CPC, MSWEP (Multi‐Source Weighted‐Ensemble Precipitation, version 2), HydroGFD (Hydrological Global Forcing Data), CFSR rank among top four. Based on the first five rankings of all metrics, fused (multiple sourced) and gridded datasets accurately reflect the actual situations compared to other precipitation products. Reanalysis (model) and satellite‐based follow this rank, respectively. The results clearly indicate that fused precipitation derived products from multiple sources offer better accuracy and precision in representing the spatial distribution of precipitation on a daily scale.
The study of micellar transitions in mixed systems of dibranched cationic/nonionic fluorinated surfactants using various physicochemical methods
Authors: Sardi Amina , Kradra Brahma Khadidja , Bennabi Souad , Abdelkrim Soumia 
Published: October 2024

AbstractIn this study, a new method was introduced to induce micellar transitions by using vesicles formed from mixed surfactants, which offer enhanced stability. Different physicochemical analysis methods were used to study the transition mechanism and the aggregation behavior of the mixed aqueous system composed of the double‐chain cationic didodecyldimethylammonium bromide (DDAB) and a single‐chain nonionic fluorinated surfactant undecafluoro n‐pentyl decaoxyethylene ether (C5F11(EO)10), by varying the fraction of DDAB, then the total surfactant concentration of DDAB/C5F11(EO)10 mixed system at XDDAB = 0.9. The obtained results indicated that the addition of the fluorinated surfactant C5F11(EO)10 to the mixed system resulted in a reduction of the surface tension (γ) and a decrease in the Electrical conductivity (K). Furthermore, even at high total concentrations of the mixed system, the conductivity and charge density at the surface remained stable. As XDDAB values increased, a higher degree of dissociation (α) was observed, along with negative values in the thermodynamic parameters of micellization (Δ, Δ, and Δ), confirming the transition from micelles to vesicles. The dynamic light scattering (DLS) analysis revealed the formation of two stable types of aggregates at both low and high concentrations, as supported by the zeta potential (ζ). Upon increasing the concentration of surfactants, UV–Vis absorption measurements indicated that small spherical micelles grow into large multilamellar vesicles, as evidenced by an increase in turbidity and confirmed transmission electron microscopy images.
Automatic segmentation and diameter measurement of deep medullary veins
Authors: Zhou Yichen , Zhao Bingbing , Moore Julia , Zong Xiaopeng 
Published: October 2024

AbstractPurposeAs one of the pathogenic factors of cerebral small vessel disease, venous collagenosis may result in the occlusion or stenosis of deep medullary veins (DMVs). Although numerous DMVs can be observed in susceptibility‐weighted MRI images, their diameters are usually smaller than the MRI resolution, making it difficult to segment them and quantify their sizes. We aim to automatically segment DMVs and measure their diameters from gradient‐echo images.MethodsA neural network model was trained for DMV segmentation based on the gradient‐echo magnitude and phase images of 20 subjects at 7 T. The diameters of DMVs were obtained by fitting measured complex images with model images that accounted for the DMV‐induced magnetic field and point spread function. A phantom study with graphite rods of different diameters was conducted to validate the proposed method. Simulation was carried out to evaluate the voxel‐size dependence of measurement accuracy for a typical DMV size.ResultsThe automatically segmented DMV masks had Dice similarity coefficients of 0.68 ± 0.03 (voxel level) and 0.83 ± 0.04 (cluster level). The fitted graphite‐rod diameters closely matched their true values. In simulation, the fitted diameters closely matched the true value when voxel size was ≤ 0.45 mm, and 92.2% of DMVs had diameters between 90 μm and 200 μm with a peak at about 120 μm, which agreed well with an earlier ex vivo report.ConclusionThe proposed methods enabled efficient and quantitative study of DMVs, which may help illuminate the role of DMVs in the etiopathogenesis of cerebral small vessel disease.
Spannende Moleküle
Authors: Golfmann Maxim , Walker Johannes 
Published: October 2024

AbstractEs gibt viele Arten, wie organische Moleküle unter Spannung stehen können. Setzen sie diese Energie frei, kommen neue Reaktionen oder Strukturen heraus. Einige Moleküle lassen sich nicht nur isolieren, sondern in Medikamente einbauen – und ein gespannter Cyclus war Grund für einen Nobelpreis.
Triple‐oxygen isotopes of stony micrometeorites by secondary ion mass spectrometry (SIMS): Olivine, basaltic glass and iron oxide matrix effects for sensitive high‐mass resolution ion microprobe‐stable isotope (SHRIMP‐SI)
Authors: McKibbin Seann J. , Ávila Janaína N. , Ireland Trevor R. , Van Ginneken Matthias , Soens Bastien , Van Maldeghem Flore , Huber Matthew , Baeza Leonardo , Patkar Aditya , Vanhaecke Frank , Debaille Vinciane , Claeys Philippe , Goderis Steven 
Published: October 2024

RationaleMicrometeorites are extraterrestrial particles smaller than ~2 mm in diameter, most of which melted during atmospheric entry and crystallised or quenched to form ‘cosmic spherules’. Their parentage among meteorite groups can be inferred from triple‐oxygen isotope compositions, for example, by secondary ion mass spectrometry (SIMS). This method uses sample efficiently, preserving spherules for other investigations. While SIMS precisions are improving steadily, application requires assumptions about instrumental mass fractionation, which is controlled by sample chemistry and mineralogy (matrix effects).MethodsWe have developed a generic SIMS method using sensitive high‐mass resolution ion micro probe‐stable isotope (SHRIMP‐SI) that can be applied to finely crystalline igneous textures as in cosmic spherules. We correct for oxygen isotope matrix effects using the bulk chemistry of samples obtained by laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) and model bulk chemical compositions as three‐component mixtures of olivine, basaltic glass and Fe‐oxide (magnetite), finding a unique matrix correction for each target.ResultsOur first results for cosmic spherules from East Antarctica compare favourably with established micrometeorite groups defined by precise and accurate but consumptive bulk oxygen isotope methods. The Fe‐oxide content of each spherule is the main control on magnitude of oxygen isotope ratio bias, with effects on δ18O up to ~6‰. Our main peak in compositions closely coincides with so‐called ‘Group 1’ objects identified by consumptive methods.ConclusionsThe magnitude of SIMS matrix effects we find is similar to the previous intraspherule variations, which are now the limiting factor in understanding their compositions. The matrix effect for each spherule should be assessed quantitatively and individually, especially addressing Fe‐oxide content. We expect micrometeorite triple‐oxygen isotope compositions obtained by SIMS to converge on the main clusters (Groups 1 to 4) after correction firstly for magnetite content and secondarily for other phases (e.g., basaltic glass) in each target.
How do cocaine and morphine in methanol solution desorb at the last moment of Leidenfrost phenomenon‐assisted thermal desorption?
Authors: Hiraoka Kenzo , Rankin‐Turner Stephanie , Usmanov Dilshadbek T. , Akhmedov Sherzod M. , Ninomiya Satoshi 
Published: October 2024

RationaleThe objective of the present study is to investigate desorption of low‐volatility analytes in Leidenfrost phenomenon‐assisted thermal desorption (LPTD).MethodsLPTD was investigated for 5 μL solutions of 0.03 ppm cocaine or morphine in methanol (sample weight: 0.12 ng) by using heated metal surfaces (240°C) polished by abrasives with grit numbers from #5000 (~3 μm) to #100 (~200 μm).ResultsThe analyte signals were detected only after the complete evaporation of methanol solvent and the formed analyte residues levitated on the heater surface. The strongest ion signals were obtained with grit number #100.ConclusionsBecause the analyte residue does not come into contact with the heated surface but levitates on the hot substrate after the evaporation of the solvent, thermal decomposition of the analyte is largely suppressed. This is a great merit of LPTD for trace analysis of low‐volatility and thermally labile compounds.
A Quasilinear Quadratic Tracking Method for Systems With Saturating Actuators
Authors: He Lidong , Li Mengran , Ni Yuqing , Tong Yanhui 
Published: October 2024

ABSTRACTLinear quadratic tracker (LQT) is usually employed to solve unconstrained tracking problems but falls short when dealing with systems exhibiting actuator saturation. This paper presents a novel quasilinear quadratic tracking method specifically designed to address this scenario. Firstly, the stochastic linearization (SL) approach is utilized to approximate the saturation nonlinearity with equivalent gains and biases using statistical properties of its input, which are thus incorporated into the system model so as to eliminate the nonlinearity. Then, different time scales are applied in the tracking controller and states in order to improve tracking accuracy. In addition, to reduce computational complexity, two algorithms are provided for approximating the equivalent gains and biases, catering to both scalar and vector control signals. Finally, the proposed algorithms are evaluated through numerical examples, demonstrating their effectiveness and superior tracking performances.
Dose Individualization for Phase I Cancer Trials With Broadened Eligibility
Authors: Silva Rebecca B. , Cheng Bin , Carvajal Richard D. , Lee Shing M. 
Published: October 2024

ABSTRACTBroadening eligibility criteria in cancer trials has been advocated to represent the intended patient population more accurately. The advantages are clear in terms of generalizability and recruitment, however there are some important considerations in terms of design for efficiency and patient safety. While toxicity may be expected to be homogeneous across these subpopulations, designs should be able to recommend safe and precise doses if subpopulations with different toxicity profiles exist. Dose‐finding designs accounting for patient heterogeneity have been proposed, but existing methods assume that the source of heterogeneity is known. We propose a broadened eligibility dose‐finding design to address the situation of unknown patient heterogeneity in phase I cancer clinical trials where eligibility is expanded, and multiple eligibility criteria could potentially lead to different optimal doses for patient subgroups. The design offers a two‐in‐one approach to dose‐finding by simultaneously selecting patient criteria that differentiate the maximum tolerated dose (MTD), using stochastic search variable selection, and recommending the subpopulation‐specific MTD if needed. Our simulation study compares the proposed design to the naive approach of assuming patient homogeneity and demonstrates favorable operating characteristics across a wide range of scenarios, allocating patients more often to their true MTD during the trial, recommending more than one MTD when needed, and identifying criteria that differentiate the patient population. The proposed design highlights the advantages of adding more variability at an early stage and demonstrates how assuming patient homogeneity can lead to unsafe or sub‐therapeutic dose recommendations.
Hydrogen Spillover‐Bridged Interfacial Water Activation of WCx and Hydrogen Recombination of Ru as Dual Active Sites for Accelerating Electrocatalytic Hydrogen Evolution
Authors: Zhao Jiamin , Kou Meimei , Yuan Qing , Yuan Ying , Zhao Jinsheng 
Published: October 2024

AbstractTungsten carbide (WCx) is a promising alternative to platinum catalysts for hydrogen evolution reaction (HER). However, strong tungsten–hydrogen bond hinders hydrogen desorption while favoring H+ reduction, thus limiting HER kinetics. Inspired by the phenomenon of hydrogen spillover in heterogeneous catalysis, a ruthenium (Ru) doped‐driven activated hydrogen migration from WCx surface to Ru is reported. This approach achieved high activity with an ultralow overpotential of 9.0 mV at 10 mA·cm−2 and superior stability at an industrial‐grade current density of 1.0 A·cm−2 @ 1.65 V. In situ attenuated total reflectance surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS) and operando electrochemical impedance spectra revealed that this exceptional hydrogen production—which surpasses that of previously reported Pt/C catalysts—is attributable to the outstanding ability of WCx to induce water dissociation and hydrogen spillover from WCx to Ru surface. During the HER process, the rigid interfacial water network negatively affected the HER efficiency under alkaline conditions. The WCx sites disrupted this rigid structure, facilitating the contact between activated hydrogen (H*) and WCx sites. Subsequently, H* migrates to Ru surface, where hydrogen recombination occurs to produce H2. This work paves a new avenue for the construction of coupled catalysts at the atomic scale to facilitate HER electrocatalysis.
Controlled Distribution of MXene on the Pore Walls of Polyarylene Ether Nitrile Porous Films for Absorption‐Dominated Electromagnetic Interference Shielding Materials
Authors: Wei Renbo , Liu Kexin , Liu Yongxian , Wang Zaixing , Jiao Yayao , Huo Qi , Hua Xiufu , Wang Lingling , Wang Xun 
Published: October 2024

AbstractWith the increasing application of electronic devices, absorption‐dominated electromagnetic interference shielding materials (EMISM) have garnered significant attention for preventing secondary electromagnetic pollution. In this study, polyethyleneimine (PEI)‐modified MXene (PEI@MXene) is fabricated and achieved its controlled distribution on the pore walls of polyarylene ether nitrile (PEN) porous films via the phase inversion method (PIM) to obtain a closed porous skeleton of MXene on the pore walls (CPS–MPW). The resulting PEI@MXene/PEN composite film (CFx) exhibited absorption‐dominated EMIS efficiency (EMISE). Attributing to the strong interaction between PEI and the hydrophilic segment of amphiphilic Pluronic F127, with its hydrophobic segment anchored by the PEN matrix, PEI@MXene is directionally distributed on the pore walls of CFx. In addition, resulting from the cladding of MXene with PEI and isolating it with closed honeycomb pores, the obtained CFx are insulators without forming a conductive network. As a result, these CFx demonstrate absorption‐dominated EMISE with the highest SET of 41.2 dB and coefficient A higher than 0.51. Further continuous hot pressing of CFx results in thinner and denser films with an impressive specific EMISE up to 750 dB cm−1. The successful fabrication of these CPS–MPW‐type CFx with absorption‐dominated EMISE provides a reference for developing and preparing novel EMISM.