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Rare earth-doped mixed Ni-Cu-Zn ferrites as an effective photocatalytic agent for active degradation of Rhodamine b dye

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Journal of Rare Earths 2024年第3期42卷 488-496,I0003页

作者： Swapnil A.Jadhav Sandeep b.Somvanshi Sudarshan S.Gawali kranti Zakde k.M.Jadhav Department of Physics Dr.Babasaheb Ambedkar Marathwada UniversityAurangabad431004MaharashtraIndia School of Materials Engineering Purdue UniversityWest Lafayette 47906USA University Department of basic and Applied Sciences MGM UniversityAurangabad431003MaharashtraIndia

In this study, a series of Gd^(3+)-doped mixed Ni-Cu-Zn ferrites with composition of Zn_(0.5)Ni_(0.3)Cu_(0.2)Fe_(2-x)Gd_(x)O_(4)(x = 0, 0.025, 0.05, 0.075, 0.1) was prepared using self-ignition sol-gel method. The prepared nanoparticles with an average size ranging from 22 to 26 nm show a single-phase cubic structure belonging to the spinel matrix. A rise in the Gd^(3+)concentration leads to an increase in crystallite size and lattice parameter. In Fourier transform infrared spectra, two main absorption bands belonging to the spinel structure are observed. The high-frequency bands(v_(1)) represent the tetrahedral complex, while the lowfrequency bands(v_(2)) signify the octahedral complex. The optical bandgap of the nanoferrites is found within the range of 2.91 to 2.41 eV, depending on their size. The magnetic characteristics of the material,such as saturation magnetization and coercivity are significantly altered with the concentration of Gd^(3+)in the solution. Using Rhodamine b(Rhb) as a model organic pollutant, an in-depth investigation of the photocatalytic activity of the compounds was carried out. The present outcomes show that adding an adequate amount of Gd^(3+)significantly enhances the number of hydroxyl radicals produced by the ferrite,in turn, increasing the photocatalytic activity of the material. Mechanism elucidated by scavenger studies reveals that ·OH and holes are the primary reactive radicals responsible for the degradation *** photocatalysts show an insignificant performance loss in five consecutive cycles. Thus, it is concluded that these photocatalysts are highly suitable for the remediation of dye-contaminated wastewater.

关键词： Gd^(3+)substitution Spinel ferrite Structural properties Magnetic properties Photocatalysis Rare earths

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A Hybrid Machine Learning Approach for Improvised QoE in Video Services over 5G Wireless Networks

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Computers, Materials & Continua 2024年第3期78卷 3195-3213页

作者： k.b.ajeyp.asaath P.Vetrivelan School of Electronics Engineering Vellore Institute of TechnologyChennaiTamil Nadu600127India

Video streaming applications have grown considerably in recent *** a result,this becomes one of the most significant contributors to global internet *** to recent studies,the telecommunications industry loses millions of dollars due to poor video Quality of Experience(QoE)for *** the standard proposals for standardizing the quality of video streaming over internet service providers(ISPs)is the Mean Opinion Score(MOS).However,the accurate finding of QoE by MOS is subjective and laborious,and it varies depending on the user.A fully automated data analytics framework is required to reduce the inter-operator variability characteristic in QoE *** work addresses this concern by suggesting a novel hybrid XGbStackQoE analytical model using a two-level layering *** one combines multiple Machine Learning(ML)models via a layer one Hybrid *** ML models at level one are trained using the entire training data *** level two Hybrid XGbStackQoE-Model is fitted using the outputs(meta-features)of the layer one ML *** proposed model outperformed the conventional models,with an accuracy improvement of 4 to 5 percent,which is still higher than the current traditional *** proposed framework could significantly improve video QoE accuracy.

关键词： Hybrid XGbStackQoE-model machine learning MOS performance metrics QoE 5G video services

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Smart mid-infrared metasurface microspectrometer gas sensing system

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Microsystems & Nanoengineering 2024年第3期10卷 273-281页

作者： Jiajun Meng Sivacarendran balendhran Ylias Sabri Suresh k.bhargava kenneth b.Crozier School of Physics University of MelbourneVictoriaAustralia Australian Research Council(ARC)Centre of Excellence for Transformative Meta-Optical Systems(TMOS) University of MelbourneVictoriaAustralia Centre for Advanced Materials&Industrial Chemistry(CAMIC) STEM collegeRMIT UniversityVictoriaAustralia Department of Electrical and Electronic Engineering University of MelbourneVictoriaAustralia

Smart,low-cost and portable gas sensors are highly desired due to the importance of air quality monitoring for environmental and defense-related ***,electrochemical and nondispersive infrared(IR)gas sensors are designed to detect a single specific *** IR spectroscopy-based sensors provide superior performance,their deployment is limited due to their large size and high *** this study,a smart,low-cost,multigas sensing system is demonstrated consisting of a mid-infrared microspectrometer and a machine learning *** microspectrometer is a metasurface filter array integrated with a commercial IR camera that is consumable-free,compact(~1 cm^(3))and lightweight(~1 g).The machine learning algorithm is trained to analyze the data from the microspectrometer and predict the gases *** system detects the greenhouse gases carbon dioxide and methane at concentrations ranging from 10 to 100%with 100%*** also detects hazardous gases at low concentrations with an accuracy of 98.4%.Ammonia can be detected at a concentration of 100 ***,methyl-ethyl-ketone can be detected at its permissible exposure limit(200 ppm);this concentration is considered low and *** study demonstrates the viability of using machine learning with IR spectroscopy to provide a smart and low-cost multigas sensing platform.

关键词： Smart gases system

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Excellent photoluminescence and electrochemical properties of Sm^(3+) doped Ca_(2)MgSi_(2)O_(7) nanophosphor:Display and electrochemical sensor applications

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Journal of Rare Earths 2024年第6期42卷 1046-1055,I0002页

作者： R.b.basavaraj k.Sureshkumar D.P.Aarti M.b.Madhusudana Reddy G.Nagaraju T.Ramakrishnappa G.R.Navyashree k.R.Venkatesha babu k.S.Hemalatha Department of Physics BMS Institute of Technology and ManagementBangalore560064India Department of Chemistry BMS Institute of Technology and ManagementBangalore560064India Department of Chemistry School of Applied SciencesREVA UniversityBangalore560064India Energy Materials ResearchLaboratory Department of ChemistrySiddaganga Institute of TechnologyTumakuru57203KarnatakaIndia School of Physical Sciences REVA UniversityBangalore560057Indi Department of Physics Govt.Science CollegeBengaluru560001India Department of Physics Maharani Science College for WomenMaharani Cluster UniversityBengaluru560001India

A series of orange-red light emitting Ca_(2)MgSi_(2)O_(7):Sm^(3+)nanopowders were fabricated via low-cost ecofriendly green combustion technique using Aloe vera gel as *** phase purity of the samples were confirmed by the powder X-ray diffraction(PXRD)*** single-phase tetragonal structure is observed from the PXRD results with no additional impurity *** band gap energy of the fabricated powders was estimated by diffuse reflectance spectra(DRS)and is found to be in the range of 4.01-5.98 eV.A high resolution scanning electron microscope(SEM)was used to study the morphological behaviour of the ***-like structures are observed from the SEM *** particle size was evaluated by transmission electron microscopy(TEM)and is found to be~50 *** interplanar distance is found to be 0.53 *** properties were systematically studied in *** phosphors are successfully excited at 403 nm NUV light,producing reddish-orange characteristic *** emission peaks are centered at 558(^(4)G_(5/2)→^(6)H_(5/2)),607(^(4)G_(5/2)→^(6)H_(7/2))and 645 nm(^(4)G_(5/2)→^(6)H_(9/2)),*** the observed peaks the red emanation(^(4)G_(5/2)→^(6)H_(7/2))is stronger than the orange emission(^(4)G_(5/2)→^(6)H_(5/2))in the current *** photoluminescent concentration quenching is noticed above 5 mol%Sm^(3+)ion doping *** dipole-dipole interaction resulting in cross relaxation is found to be the principal cause of concentration quenching *** color features such as Commission Internationale de I’Eclairage(CIE)and correlated color temperature(CCT)were studied in *** optimized chromaticity coordinates were estimated to be(0.6363,0.3632),which fall in the reddish-orange *** average CCT value obtained is 3362 *** average color purity is found to be~82%.Sm^(3+)incorporated Ca_(2)MgSi_(2)O_(7) samples are possible contender for single white light generation commercial candidates owing to

关键词： Green combustion Photoluminescence Orange-red emission Color purity Sensors Rare earths

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Finite element analysis and experimental validation of polymer-metal contacts in block-on-ring configuration

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Friction 2024年第3期12卷 554-568页

作者： k.Y.Eayal AWWAD khosro FALLAHNEZHAD b.F.YOUSIF Ahmad MOSTAFA Omar ALAJARMEH A.SHALWAN Xuesen ZENG Mechanical Engineering Department Faculty of EngineeringTafila Technical UniversityTafila 66110Jordan Medical Device Research Institute College of Science and EngineeringFlinders UniversitySouth Australia 5042Australia Centre for Future Materials University of Southern QueenslandToowoomba 4350Australia Department of Manufacturing Engineering Technology Public Authority for Applied Education and TrainingKuwait 13092Kuwait

The wear profile analysis,obtained by different tribometers,is essential to characterise the wear ***,most of the available methods did not take the stress distribution over the wear profile in consideration,which causes inaccurate *** this study,the wear profile of polymer–metal contact,obtained by block-on-ring configuration under dry sliding conditions,was analysed using finite element modelling(FEM)and experimental ***’s wear equation was integrated into a developed FORTRAN-UMESHMOTION code linked with Abaqus software.A varying wear coefficient(k)values covering both running-in and steady state regions,and a range of applied loads involving both mild and severe wear regions were measured and implemented in the *** FEM was in good agreement with the *** model reproduced the stress distribution profiles under variable testing conditions,while their values were affected by the sliding direction and maximum wear depth(hmax).The largest area of the wear profile,exposed to the average contact stresses,is defined as the normal *** the critical zones were characterized by high stress concentrations reaching up to 10 times of that at the normal *** wear profile was mapped to identify the critical zone where the stress concentration is the key point in this *** surface features were examined in different regions using scanning electron microscope(SEM).Ultimately,SEM analysis showed severer damage features in the critical zone than that in the normal zone as proven by ***,the literature data presented and considered the wear features the same at any point of the wear *** this study,the normal zone was determined at a stress value of about 0.5 MPa,whereas the critical zone was at about 5.5 *** wear behaviour of these two zones showed totally different features from one another.

关键词： polymer-to-metal contact block-on-ring wear profile wear model

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The magnetosheath at high spectral resolution

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Earth and Planetary Physics 2024年第1期8卷 234-246页

作者： k.D.küntz D.koutroumpa W.R.Dunn A.Foster F.S.Porter D.G.Sibeck b.Walsh The Henry A.Rowland Department of Physics and Astronomy Johns Hopkins University3701 San Martin DriveBaltimoreMD21218USA NASA Goddard Space Flight Center 8800 Greenbelt RoadGreenbeltMD 20771USA LATMOS-OVSQ CNRSUVSQ Paris-SaclaySorbonne Université11 Boulevard d’Alembert78280GuyancourtFrance Department of Physics and Astronomy University College LondonLondonUK The Centre for Planetary Science at UCL/birkbeck Gower StreetLondon WC1E 6BTUK Center for Astrophysics Harvard University&Smithsonian Institution60 Garden StreetCambridgeMA 02138USA Center for Space Physics Boston University110 Cummington MallBostonMAUSA

While we eagerly anticipate SMILE’s(Solar wind Magnetosphere Ionosphere Link Explorer)unprecedented X-ray observations of the Earth’s magnetosheath and the initiation of a new era of magnetospheric research,it seems appropriate to look ahead to the abilities of the next generation of astrophysics *** these,the Line Emission Mapper(LEM),a large aperture micro-calorimeter based mission,is currently planned to be able to observe the magnetosheath at high spectral resolution(~2 eV).With a field of view of~30′,LEM will allow higher spatial resolution and higher cadence measurement of the motion of a very small portion of the magnetopause over relatively short periods of time(multiple hours),complementing SMILE’s global ***’s strength is its spectral *** will be able to measure the abundance of a broad range of elements and ionization states,many of which are inaccessible to current in situ instruments,and will be able to separate the emission from the magnetosheath from the emission from the cosmic X-ray background using the difference in their relative velocities.

关键词： magnetosheath charge exchange solar wind abundances

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Advances in discovery of novel investigational agents for functional cure of chronic hepatitis b:A comprehensive review of phases II and III therapeutic agents

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World Journal of Hepatology 2024年第3期16卷 331-343页

作者： Robert Lam Joseph k Lim Section of Digestive Diseases Yale University School of MedicineNew HavenCT 06520United States

Chronic hepatitis b virus(HbV)infection affects over 295 million people globally and an estimated 1.6 million people in the United *** is associated with significant morbidity and mortality due to cirrhosis,liver failure,and liver *** therapy with oral nucleos(t)ide analogues is associated with high rates of virologic suppression,which in turn has been associated with a decreased risk of liver ***,current antiviral regimens are limited by concerns with adverse effects,adherence,resistance,long-term treatment,and ongoing risk for liver *** investigational agents are currently in development and are targeted at achieving functional cure with sustained hepatitis b surface antigen(HbsAg)loss and suppression of HbV *** we review key evidence from phases II and III trials defining the efficacy and safety profiles for key investigational agents for functional cure of chronic hepatitis b,including core/capsid inhibitors,entry inhibitors,RNA interference(siRNA/ASO),HbsAg inhibitors,Toll-like receptor agonists,checkpoint inhibitors,and therapeutic vaccines.

关键词： Hepatitis b virus Treatment Clinical trials RNA interference Entry inhibitors Core inhibitors Immunomodulators

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Optimization of chemistry and process parameters for control of intermetallic formation in Mg sludges

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Journal of Magnesium and Alloys 2024年第4期12卷 1431-1448页

作者： Y.Fu G.G.Wang A.Hu Y.Li k.b.Thacker J.P.Weiler H.Hu Department of Mechanical Automotive and Materials EngineeringUniversity of Windsor401 Sunset AveWindsorOntario N9B 3P4Canada Global Technology Centre Meridian Lightweight Technologies25 MacNab AveStrathroyOntario N7G 4H6Canada

Intermetallic formation in sludge during magnesium(Mg)melting,holding and high pressure die casting practices is a very important ***,very often it is overlooked by academia,original equipment manufacturers(OEM),metal ingot producers and even die *** aim of this study was to minimize the intermetallic formation in Mg sludge via the optimization of the chemistry and process *** Al8Mn5 intermetallic particles were identified by the microstructure analysis based on the Al and Mn *** design of experiment(DOE)technique,Taguchi method,was employed to minimize the intermetallic formation in the sludge of Mg alloys with various chemical compositions of Al,Mn,Fe,and different process parameters,holding temperature and holding *** sludge yield(SY)and intermetallic size(IS)was selected as two *** optimum combination of the levels in terms of minimizing the intermetallic formation were 9 wt.%Al,0.15 wt.%Mn,0.001 wt.%(10 ppm)Fe,690℃ for the holding temperature and holding at 30 mins for the holding time,*** best combination for smallest intermetallic size were 9 wt.%Al,0.15 wt.%Mn,0.001 wt.%(10 ppm)Fe,630℃ for the holding temperature and holding at 60 mins for the holding time,*** groups of sludge factors,Chemical Sludge(CSF),Physical Sludge(PSF)and Comprehensive Sludge Factors(and CPSF)were established for prediction of sludge yields and intermetallic sizes in Al-containing Mg *** CPSF with five independent variables including both chemical elements and process parameters gave high accuracy in prediction,as the prediction of the PSF with only the two processing parameters of the melt holding temperature and time showed a relatively large deviation from the experimental *** Chemical Sludge Factor was primarily designed for small ingot producers and die casters with a limited melting and holding capacity,of which process parameters could be fixed *** Physical Sludge Factor could be used f

关键词： Magnesium sludge Al-Mn intermetallic Optimization Taguchi method Sludge factor Chemical composition Process parameter

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Numerical Simulation of Oil-Water Two-Phase Flow in Low Permeability Tight Reservoirs based on Weighted Least Squares Meshless Method

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Fluid Dynamics and Materials Processing 2024年第7期20卷 1539-1552页

作者： Liu X. Yan k. Fang b. Sun X. Feng D. Yin L. School of GeoSciences Yangtze University Wuhan 430100 China State key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University) Chengdu 610000 China Downhole Service Company Petro China Qinghai Oilfield Company Haixi 817000 China Research Institute of Drilling and Production Technology Petro China Qinghai Oilfield Company Dunhuang 736200 China PetroChina Qinghai Oilfield Company The Third Oil Plant Dunhuang 736200 China

In response to the complex characteristics of actual low-permeability tight reservoirs, this study develops a meshless-based numerical simulation method for oil-water two-phase flow in these reservoirs, considering complex boundary shapes. Utilizing radial basis function point interpolation, the method approximates shape functions for unknown functions within the nodal influence domain. The shape functions constructed by the aforementioned meshless interpolation method have δ-function properties, which facilitate the handling of essential aspects like the controlled bottom-hole flow pressure in horizontal wells. Moreover, the meshless method offers greater flexibility and freedom compared to grid cell discretization, making it simpler to discretize complex geometries. A variational principle for the flow control equation group is introduced using a weighted least squares meshless method, and the pressure distribution is solved implicitly. Example results demonstrate that the computational outcomes of the meshless point cloud model, which has a relatively small degree of freedom, are in close agreement with those of the Discrete Fracture Model (DFM) employing refined grid partitioning, with pressure calculation accuracy exceeding 98.2%. Compared to high-resolution grid-based computational methods, the meshless method can achieve a better balance between computational efficiency and accuracy. Additionally, the impact of fracture half-length on the productivity of horizontal wells is discussed. The results indicate that increasing the fracture half-length is an effective strategy for enhancing production from the perspective of cumulative oil production. © (2024), (Tech Science Press). All Rights Reserved.

关键词： fracture half-length meshless method numerical simulation of low permeability tight reservoirs oil-water two-phase flow Weighted least squares method

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Verification and Validation of High-Resolution Inviscid and Viscous Conical Nozzle Flows

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Communications on Applied Mathematics and Computation 2024年第1期6卷 533-549页

作者： Luciano k.Araki Rafael b.de R.borges Nicholas Dicati P.da Silva Chi-Wang Shu Department of Mechanical Engineering Federal University of ParanáCuritiba81531-980ParanáBrazil Mathematics and Statistics Institute Rio de Janeiro State UniversityRio de Janeiro20550-900Rio de JaneiroBrazil Department of Mechanical Engineering State University of MaringáMaringá87020-900ParanáBrazil Division of Applied Mathematics Brown UniversityProvidenceRI02912USA

Capturing elaborated flow structures and phenomena is required for well-solved numerical *** finite difference methods allow simple discretization of mesh and model ***,they need simpler meshes,e.g.,*** inverse Lax-Wendroff(ILW)procedure can handle complex geometries for rectangular ***-resolution and high-order methods can capture elaborated flow structures and *** also have strong mathematical and physical backgrounds,such as positivity-preserving,jump conditions,and wave propagation *** perceive an effort toward direct numerical simulation,for instance,regarding weighted essentially non-oscillatory(WENO)***,we propose to solve a challenging engineering application without turbulence *** aim to verify and validate recent high-resolution and high-order *** check the solver accuracy,we solved vortex and Couette ***,we solved inviscid and viscous nozzle flows for a conical *** employed the finite difference method,positivity-preserving Lax-Friedrichs splitting,high-resolution viscous terms discretization,fifth-order multi-resolution WENO,ILW,and third-order strong stability preserving *** showed the solver is high-order and captured elaborated flow structures and *** can see oblique shocks in both nozzle *** the viscous flow,we also captured a free-shock separation,recirculation,entrainment region,Mach disk,and the diamond-shaped pattern of nozzle flows.

关键词： High-resolution Compressible Navier-Stokes Free-shock separation Nozzle flow

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