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Thermal properties and high-temperature ablation of high-entropy (Ti_(0.25)V_(0.25)Zr_(0.25)Hf_(0.25))B_(2) coating on graphite substrate

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Journal of Advanced Ceramics 2024年第8期13卷 1268-1281页

作者： Ana C.Feltrin Daniel Hedman farid Akhtar Division of Materials Science Lulea University of TechnologyLulea 97187Sweden Center for Multidimensional Carbon Materials(CMCM) Institute for Basic Science(IBS)Ulsan 44919Republic of Korea

An entropy-stabilized multicomponent ultrahigh-temperature ceramic(UHTC)coating,(Ti_(0.25)V_(0.25)Zr_(0.25)Hf_(0.25))B_(2),on a graphite substrate was in-situ sintered by spark plasma sintering(SPs)from constituent transition metal diboride ***(Ti_(0.25)V_(0.25)Zr_(0.25)Hf_(0.25))B_(2) coating had a hardness of 31.2±2.1 GPa and resisted 36.9 GPa of stress before delamination,as observed at the *** temperature-dependent thermal properties of the multicomponent diboride(Ti_(0.25)V_(0.25)Zr_(0.25)Hf_(0.25))B_(2) were obtained by molecular dynamics(MD)simulations driven by a machine learning force field(MLFF)trained on density functional theory(DFT)*** thermal conductivity,density,heat capacity,and coefficient of thermal expansion obtained by the MD simulations were used in time-dependent thermal stress finite element model(FEM)*** low thermal conductivity(<6.52 W·m^(-1)·K^(-1))of the multicomponent diboride coupled with its similar coefficient of thermal expansion to that of graphite indicated that stresses of less than 10 GPa were generated at the interface at high temperatures,and therefore,the coating was mechanically resistant to the thermal stress induced during *** experiments at 220℃ showed that the multicomponent diboride coating was resistant to thermal stresses with no visible cracking or *** ablation mechanisms were mechanical denudation and evaporation of B_(2)O_(5) and light V-Ti oxides,which caused a decrease in the mass and thickness of the coating and resulted in mass and linear ablation rates of-0.51 mg·s^(-1) and -1.38μm·s^(-1),respectively,after 60 *** findings demonstrated the thermal and mechanical stability of multicomponent entropy-stabilized diborides as coatings for carbon materials in engineering components under extreme environments.

关键词： entropy-stabilized diborides ultrahigh temperature ceramics molecular dynamics(MD)simulations density functional theory(DFT) ablation properties

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PPA-SiO_2 catalyzed efficient synthesis of polyhydroquinoline derivatives through Hantzsch multicomponent condensation under solvent-free conditions

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Chinese Chemical Letters 2011年第7期22卷 807-810页

作者： Amir Khojastehnezhad farid Moeinpour Abolghasem Davoodnia Department of Chemistry Faculty of SciencesIslamic Azad UniversityMashhad BranchMashhad 91735-413Iran Department of Chemistry Faculty of SciencesIslamic Azad UniversityBandar Abbas BranchIran

Silica gel-supported polyphosphoric acid （PPA-SiO2） was found to be an efficient catalyst for the one-pot four-component Hantzsch condensation reaction of aryl aldehydes, dimedone, ethyl acetoacetate and ammonium acetate to afford the corresponding polyhydroquinoline derivatives in high yields. The main advantages of the present approach are short reaction times, clean reaction profiles, simple experimental and workup procedures.

关键词： Multicomponent reaction One-pot synthesis Solvent-free Polyhydroquinoline derivatives Silica-supported polyphosphoric acid (PPA-SiO2)

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PtCu dendroframe octahedrons:Enhancing peroxidase-like activity and antibacterial efficiency through structural evolution

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Nano Research 2025年第1期18卷 100-106页

作者： Ri Feng Jiuyi Hu Liangjun Wang Jiayu Xu Jiajia Li Zeeshan Ahmad Shaohui Zheng Muhammad Farhan farid Wenjing Liu Faisal Saleem Key Laboratory of Flexible Electronics(KLOFE) Institute of Advanced Materials(IAM)and School of Flexible Electronics(Future Technologies)Nanjing Tech UniversityNanjing 211816China

Nanozymes,which possess enzyme-like catalytic activity,are attractive alternatives to natural *** activity is largely dependent on the structure of the ***,challenges remain in optimizing the structure-activity *** work explores the synthesis and utilization of PtCu nanostructures(NSs),focusing on their peroxidase(POD)-like properties and their potential as antibacterial *** developed PtCu dendrites that transform into unique dendroframe octahedrons(DFOs)and subsequently stabilize into solid octahedrons with unusual growth *** intermediate DFO,showed higher POD-like activity in comparison to other shapes of PtCu *** DFOs also have the better ability to consume glutathione,thus enhancing their sterilization ***,we demonstrate the effectiveness of these PtCu DFOs as powerful antibacterial *** work provides valuable information on shape dependent activities of PtCu NSs in the field of biomedicine.

关键词： nanozymes antibacterials peroxidase PtCu dendroframe octahedrons dendrites

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IMPACTS OF BUILDING FUNCTION ON NORMALIZED-STEAM CONSUMPTION:ANALYSIS OF FLOOR AREA NORMALIZATION VERSUS LINEAR REGRESSION ON HEATING DEGREE-DAYS IN A HEATING-DOMINATED CLIMATE

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Journal of Green Building 2021年第3期16卷 73-85页

作者： Mahsa farid Mohajer Ajla Aksamija Department of Environmental Conservation University of Massachusetts Amherst School of Architecture University of Utah375 South 1530 EastSuite 235Salt Lake CityUT 84112

Linear regression analysis is one the most common methods for weather-normalizing energy data,where energy versus degree-days is plotted,quantifying the impacts of outside temperature on buildings’energy ***,this approach solely con-siders dry-bulb temperature,while other climate variables are *** addition,depending on buildings’internal loads,weather impact can be less influential,making the linear regression method not applicable for energy data normalization in inter-nally driven buildings(such as research laboratory buildings,healthcare facilities,etc.).In this study,several existing buildings from different categories,all located on the University of Massachusetts Amherst campus and exposed to the same weather conditions in a heating-dominated climate,were *** all cases,regression of monthly steam use on heating degree-days and floor-area normalized steam data were used,investigating applicability of the former when the latter *** was found that internal loads can skew steam consumption,depending on the build-ing functionality,making the effect of degree-days *** laboratory-type buildings,besides heating and domestic hot water production,steam is also used for scientific ***,daily occupancy percentage,even during weekends and holidays,was higher than that of other buildings,indicating the intensity of scientific experiments *** significantly impacted steam consumption,resulting in higher floor-area-normalized steam *** these cases,steam use did not provide an outstanding correlation to heating ***,for cases with other func-tionality-types and lower floor-area normalized steam,coefficients of determination in regressions were *** study concludes that even for buildings located in the same climate,depending on how building functionality and occupancy schedule influ-ence floor-area normalized steam use,multivariate linear regression can provide more accurate analysis,rathe

关键词： linear regression weather normalization heating degree-days heating loads internal loads steam consumption energy usage

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A review on the rheology of heavy crude oil for pipeline transportation

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Petroleum Research 2021年第2期6卷 116-136页

作者： farid Souas Abdelhamid Safri Abdelbaki Benmounah LEGHYD Laboratory Faculty of Civil EngineeringUniversity of Science and Technology Houari Boumediene(USTHB)Bab EzzouarAlgerAlgeria Research Unit Materials Processes and Environment(UR-MPE)Faculty of Engineering ScienceUniversity M’Hamed BougaraBoumerdesAlgeria

Given the combination of rising global energy demand and the decline in conventional crudes, heavycrudes are generally considered to be the future energy resource. In many regions of the world, heavycrude oil must be transported through pipelines from the point of production to storage facilities orrefineries. The transportation of heavy crude oil by pipeline poses serious problems related to the highviscosity and flow difficulties, particularly in cold climates or offshore conditions. Indeed, the viscosity ofcrude oil is an important physical property that influences and controls crude oil flow in *** introduces resistance to movement by causing a shear or frictional force between the fluidparticles and the boundary walls. This high viscosity means that the pumping power requirements forcrude oil in a long-distance pipeline are very high in order to overcome the increasing shear and frictionforces. Therefore, in order to facilitate the pumping of these viscous oils and reduce operating expensesand the negative impact of pressure drops in pipelines during flow and processing, their viscosity mustbe reduced. Various techniques are used to increase pumping efficiency and improve the flow of crude oilthrough the pipeline, which may present logistical, technical or economic disadvantages for a givenapplication. The main ones are the addition of surfactants or polymers, dilution with lighter crudes, useof water as annular fluid, thermal remediation and emulsification with surfactant (O/W). This reviewhighlights the methods currently used to enhance the fluidity of heavy crude oil in pipelines behindrheology improvement, in particular the addition of additives and the use of water and surfactants tocreate a stable emulsion of heavy crude oil in water have been considered.

关键词： Additives Emulsion Heavy crude oil Rheology Viscosity

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Sintering behavior, microstructure and properties of TiC-FeCr hard alloy

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Journal of University of Science and Technology Beijing 2007年第1期14卷 89-93页

作者： farid Akhtar Shiju Guo Jawid Askari Jianjun Tian Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China Department of Metallurgical and Malerials Engineering University of Engineering and Technology Lahore Pakistan

TiC based cermets were produced with FeCr, as a binder, by conventional P/M （powder metallurgy） to near 〉97% of the theoretical density. Sintering temperature significantly affects the mechanical properties of the composite. The sintering temperature of 〉1360℃ caused severe chemical reaction between TiC particles and the binder phase. In the TiC-FeCr cermets, the mechanical properties did not vary linearly with the carbide content. Optimum mechanical properties were found in the composite containing 57wt% TiC reinforcement, when sintered at 1360℃ for 1 h. Use of carbon as an additive enhanced the mechanical properties of the composites. Cermets containing carbon as an additive with 49wt% TiC exhibited attractive mechanical properties. The microstructure of the developed composite contained less or no debonding, representing good wettabifity of the binder with TiC particles. Homogeneous distribution of the TiC particles ensured the presence of isotropic mechanical properties and homogeneous distribution of stresses in the composite. Preliminary experiments for evaluation of the oxidation resistance of FeCr bonded TiC cermets indicate that they are more resistant than WC-Co hardmetals.

关键词： powder technology hard alloy sintering reinforcement mechanical property

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The Response of the Earth's Lower Ionosphere to Gamma-Ray Solar Flares and their Associated X-ray

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Research in Astronomy and Astrophysics 2022年第4期22卷 137-152页

作者： Mahmoud Mohery Hussein M.farid Alaa Ali Dept.of Phys College of ScienceUniversity of JeddahJeddahSaudi Arabia Astronomy Space Science&Meteorology DepartmentFaculty of ScienceCairo UniversityGiza 12613Egypt Astronomy Dept. Faculty of ScienceKing Abdulaziz University21589 JeddahSaudi Arabia

The present work aims to explore the impact of solar gamma-ray fiares(GRFs),detected by the Fermi-Large Area Telescope(LAT),and their associated X-ray fiares(XRFs)on the Earth’s lower *** data of ionospheric parameter fmin were collected from the Yamagawa mid-latitude ionosonde station in *** most of the GRFs used in this study are associated with soft X-ray(SXR)emissions,detected by the Geostationary Operational Environmental Satellite(GOES),we classified them into three types:simultaneous(S),delayed(D)and not associated(N),refiecting the phase occurrence of the solar ***,the ionospheric D layer responds strongly to XRFs more than *** temporal profiles of the ionospheric parameter fmin show distinct behaviors as a response to the various GRF *** the case of the S-type,a single strong peak,with an average value of 5.2 MHz,emanates in the fmin profile within an average interval of time of less than half an *** the case of the D-type,two successive peaks appear in the fmin profile,with an average value of 6.0 MHz for the second peak through a time interval of one hour after the onset of gamma-ray(GR)*** response of the fmin parameter to the N-type fiares appears as a single peak with an average value of 4.8 MHz within about an *** notice that the difference between the fmin peak values and the corresponding reference ones(dfmin)is more convenient and representative than the fmin values,where the median GR fiux of the S-,D-and N-types tends to increase as the average dfmin increases.

关键词： Sun:X-rays gamma-rays Earth:ionosphere satellites

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An intelligent procedure for updating deformation prediction of braced excavation in clay using gated recurrent unit neural networks

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第6期13卷 1485-1499页

作者： Jie Yang Yingjing Liu Saffet Yagiz farid Laouafa Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong KongChina Zhongtian Construction Group Co.Ltd. Hangzhou310008China School of Mining and Geosciences Nazarbayev UniversityNur-Sultan010000Kazakhstan National Institute for Industrial Environment and Risks(INERIS) Verneuil-en-HalatteFrance

This paper aims to establish an intelligent procedure that combines the observational method with the existing deep learning technique for updating deformation of braced excavation in *** gated recurrent unit(GRU) neural network is adopted to formulate the forecast model and learn the potential rules in the field observations using the Nesterov-accelerated Adam(Nadam) *** the proposed procedure,the GRU-based forecast model is first trained based on the field data of previous and current ***,the field data of the current stage are used as input to predict the deformation response of the next stage via the previously trained GRU-based forecast *** updating process will loop up till the end of the *** procedure has the advantage of directly predicting the deformation response of unexcavated stages based on the monitoring *** proposed intelligent procedure is verified on two well-documented cases in terms of accuracy and *** results indicate that both wall deflection and ground settlement are accurately predicted as the excavation ***,the advantages of the proposed intelligent procedure compared with the Bayesian/o ptimization updating are illustrated.

关键词： Braced excavation Deep learning Clay Wall deflection Ground settlement Deformation updating

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The s-Ordered Fock Space Projectors Gained by the General Ordering Theorem

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Chinese Physics Letters 2012年第9期29卷 5-7页

作者： farid Shähandeh Mohammad Reza Bazrafkan Mahmoud Ashrafi Department of Physics Faculty of ScienceI.K.I.UniversityQazvinIran

Employing the general ordering theorem(GOT),operational methods and incomplete 2-D Hermite polynomials,we derive the t-ordered expansion of Fock space *** the result,the general ordered form of the coherent state projectors is *** indeed gives a new integration formula regarding incomplete 2-D Hermite *** addition,the orthogonality relation of the incomplete 2-D Hermite polynomials is derived to resolve Dattoli's failure.

关键词： incomplete ordered Fock

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Deriving some quantum optical identities using the general ordering theorem

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Chinese Physics B 2012年第11期21卷 233-236页

作者： farid Shhandeh Mohammad Reza Bazrafkan Elahe Nahvifard Physics Department Faculty of ScienceImam Khomeini International University

Using the newly introduced general ordering theorem by Sh/ihandeh and Bazrafkan, we derive and generalize some quantum optical identities and give their applications.

关键词： s-ordered expansion of operators general ordering theorem

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