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Numerical modelling of reinforced concrete flexural members strengthened using textile reinforced mortars

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Frontiers of structural and Civil Engineering 2023年第4期17卷 649-668页

作者： Naveen Revanna Charles K.s.moy Department of Civil Engineering Xi’an Jiaotong-Liverpool UniversitySuzhou 215123China

Externally bonded(EB)and near-surface mounted(Nsm)bonding are two widely adopted and researched strengthening methods for reinforced-concrete *** composite substrates are easy to reach and repair using appropriate surface treatments,whereas Nsm techniques can be easily applied to the soffit and concrete member *** EB bonded fiber-reinforced polymer(FRP)technique has a significant drawback:combustibility,which calls for external protective agents,and textile reinforced mortar(TRm),a class of EB composites that is noncombustible and provides a similar functionality to any EB FRP-strengthened *** study employs a finite element analysis technique to investigate the failing failure of carbon textile reinforced mortar(CTRm)-strengthened reinforced concrete *** principal objective of this numerical study was to develop a finite element model and validate a set of experimental data in existing literature.A set of seven beams was modelled and calibrated to obtain concrete damage plasticity(CDP)*** predicted results,which were in the form of load versus deflection,load versus rebar strain,tensile damage,and compressive damage patterns,were in good agreement with the experimental ***,a parametric study was conducted to verify the applicability of the numerical model and study various influencing factors such as the concrete strength,internal reinforcement,textile roving spacing,and externally-applied load *** ultimate load and deflection of the predicted finite element results had a coefficient of variation(COV)of 6.02%and 5.7%,respectively.A strain-based numerical comparison with known methods was then conducted to investigate the debonding *** developed finite element model can be applied and tailored further to explore similar TRm-strengthened beams undergoing debonding,and the preventive measures can be sought to avoid premature debonding.

关键词： fiber reinforced polymer textile reinforced mortar finite element analysis concrete damage plasticity calibration and validation parametric study

Role of photon-counting computed tomography in pediatric cardiovascular imaging

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World Journal of Clinical Pediatrics 2025年第1期14卷 55-62页

作者： Arosh s Perera molligoda Arachchige Yash Verma Faculty of medicine Humanitas UniversityPieve Emanuele 20072Italy Department of Radiology Mayo ClinicRochesterMN 55905United States

Photon-counting computed tomography(PCCT)represents a significant advancement in pediatric cardiovascular *** CT systems employ energy-integrating detectors that convert X-ray photons into visible light,whereas PCCT utilizes photon-counting detectors that directly transform X-ray photons into electric *** direct conversion allows photon-counting detectors to sort photons into discrete energy levels,thereby enhancing image quality through superior noise reduction,improved spatial and contrast resolution,and reduced *** pediatric applications,PCCT offers substantial benefits,including lower radiation doses,which may help reduce the risk of malignancy in pediatric patients,with perhaps greater potential to benefit those with repeated exposure from a young *** spatial resolution facilitates better visualization of small structures,vital for diagnosing congenital heart ***,PCCT’s spectral capabilities improve tissue characterization and enable the creation of virtual monoenergetic images,which enhance soft-tissue contrast and potentially reduce contrast media *** clinical results indicate that PCCT provides superior image quality and diagnostic accuracy compared to conven-tional CT,particularly in challenging pediatric cardiovascular *** PCCT technology matures,further research and standardized protocols will be essential to fully integrate it into pediatric imaging practices,ensuring optimized diagnostic outcomes and patient safety.

关键词： Cardiovascular Photon-counting detectors Pediatric Photon-counting computed tomography Computed tomography

Dynamics of Fermionic Geometric Discord beyond single-mode Approximations

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Chinese Physics Letters 2013年第6期30卷 34-37页

作者： m.Ramzan Department of Physics Quaid-i-Azam UniversityIslamabad 45320Pakistan

Geometric quantum discord of fermionic systems in the relativistic regime,that is,beyond the single-mode approximation,is *** is shown that geometric quantum discord for the fermionic systems in non-inertial frames converges at an infinite acceleration limit,which means that the fermionic systems become independent of the choice of Unruh modes(qR)beyond single-mode *** discord may vanish or be retained depending upon the level of mixedness of the fermionic *** dynamics of geometric discord are investigated under amplitude damping,depolarizing,phase damping and flipping *** vanishing behavior of discord is seen for a higher level of decoherence in the infinite acceleration *** depolarizing channel dominantly affects the fermionic geometric discord as compared to the amplitude and phase damping *** implies that the depolarizing channel has most destructive influence on the discord of the fermionic ***,the flipping channels have a symmetrical effect on the ***,the discord heavily depends on the mixedness parameter of the quantum state of the fermionic systems in accelerated frames beyond single-mode approximation.

关键词： quantum infinite frames

Heterogeneous and homogeneous reactive flow of magnetite-water nanofluid over a magnetized moving plate

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Propulsion and Power Research 2022年第2期11卷 265-275页

作者： C.s.sravanthi F.mabood s.G.Nabi s.A.shehzad Department of mathematics Faculty of ScienceThe Maharaja Sayajirao University of BarodaVadodara390002GujaratIndia Department of Information Technology Fanshawe College LondonONN5Y 5R6Canada Department of mathematics COMSATS University IslamabadSahiwal57000Pakistan

This model is dedicated to visualizing the nature of magnetite-water nanoliquid induced by a permeable plate having variable magnetic effect,non-linear radiation,heterogeneous and homogeneous chemically reactive *** system of momentum,thermal and concentration expressions is formulated and transformed from the partial to ordinary differential systems by using the adequate *** highly non-linear system is solved through RKF(Runge-Kutta-Fehlberg)numerical *** parameters such as suction/injection,magnetic,and radiation effects as well as other relevant parameters are *** graphs show that the rise in radiation parameter numerically improves the thermal distribution,implying a faster heat transfer ***-linear radiation has greater effect on temperature than the linear *** the volume concentration effect reveals that the friction factor increase with the enhancement of nanoparticle *** is also observed that,plate velocity decreases the skin-friction but increases the wall heat transfer for both suction and blowing *** results indicate that the current research has a strong agreement with the relevant data in a limiting approach.

关键词： Homogeneous-heterogeneous reactions Non-linear radiation Variable magnetic field Nanofluid moving plate

Temporal variations in runoff and soil loss in relation to soil conservation practices in catchments in shiwaliks of lower Himalayas

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International soil and Water Conservation Research 2013年第2期1卷 19-25页

作者： s.s.Kukal s.s.Bawa school of Climate Change and Agricultural meteorology Punjab Agricultural UniversityLudhianaIndia Zonal Research station for Kandi Area(PAL) NawanshaharIndia

The soil conservation strategies adopted in the catchments of shiwaliks,the most fragile region in the Himalayan ecosystem,failed to serve their purpose after a few years of their execution.A study was carried out in four differentially-treated catchments to monitor the variation in runoff and soil *** treatments imposed during 1988 included fencing,planting native vegetation and engineering structures in catchment I;planting native vegetation and fencing in catchment II;fencing alone in catchment III in addition to an untreated catchment *** soil loss during the initial years(1989–1995)of imposition of the treatments was lowest(25.2 t ha^(-1))in catchment I,treated to the maximum extent and highest(43.3 t ha^(-1))in untreated catchment *** the later period(1996–2006)the trends reversed,i.e.,catchment IV recorded the lowest(14.1 t ha^(-1))soil loss whereas catchment I recorded the highest(23.4 t ha^(-1))soil loss despite the fact that there was no change in the status of soil conservation or the characteristics of the *** runoff was 71%higher in untreated catchment than in treated catchments initially and this difference decreased to 27%during the later period.

关键词： Catchment Gully erosion sediment loss soil conservation

Old-growth mixed dipterocarp forests show variable losses and gains in aboveground biomass and standing carbon over forty years

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Forest Ecosystems 2024年第1期11卷 14-23页

作者： sisira Ediriweera Champika Bandara Tithira Lakkana shanika Jayasinghe David Woodbury Arun Dayanandan B.m.P.singhakumara Xiangcheng mi I.A.U.N.Gunatilleke C.V.s.Gunatilleke mark sAshton Department of science and Technology Uva Wellassa UniversityBadullaSri Lanka The Forest school Yale School of the EnvironmentYale UniversityNew HavenCT06511USA Department of Forestry and Environmental science University of Sri JayewardenepuraNugegodaSri Lanka state Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing100093China Botany Department University of PeradeniyaPeradeniyaSri Lanka

Background:No studies have documented long-term trends in aboveground biomass(AGB)for mixed-dipterocarp forests(mDF),the dominant rain forest type in tropical wet equatorial *** our study,we sought to document such trends over forty years across three sites representing lowland to lower montane ***:To do this,we established fifty 100 m×25 m plots in 1978 across three sites sampled along an elevation gradient,identified as mature old-growth *** measured trees for diameter at breast height that we identified to species and *** took wood samples to calculate species wood-specific *** re-measured plots in 1998 and again in ***:We show standing AGB for all sites combined to be 517.52 mg·ha^(-1)in 1978,but this declined by 17%over 40 years to 430.11 mg·ha^(-1).No differences exist among sites in AGB primarily because of considerable within site variation;but interactions of time with site show declines across sites were not uniform,one remained about the *** few species represented a high proportion of the AGB with the top five species comprising between 34%and 65%,depending upon site and year *** species,mesua nagassarium,represented a disproportionately large amount of AGB and decline over time,particularly at the low elevation ***:Our results are directly relevant to estimating AGB and standing carbon sequestered in *** study is the first to demonstrate varying but overall,declining trends in amounts of AGB among forests making predictions of biomass and standing carbon in mDF difficult over wide regions.

关键词： Western ghats shorea spp. southeast Asia sri Lanka Tropical rain forest Wood specific gravity

Risk Assessment of mediterranean sea Waters on Cooling system of Nuclear Power Plant

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Journal of Environmental Protection 2019年第6期10卷 738-744页

作者： m. s. Tawfik F. s. Tawfik siting & Environmental Department NRRA Cairo Egypt

The study evaluated the impacts such as corrosion and scale formation which may result from, using the once-through pass cooling system of a suggested nuclear power at different selected coastal regions of Alexandria coast. (Abu-Qir, sidi Kerrir, Estern Harbour, El max and sidi Abd Elrhaman). The study had used The Langelier saturation Index (LsI), which is a measure of a solution’s ability to dissolve or deposit calcium carbonate, which is often used as an indicator of the corrosivity of water. Like the Langelier saturation index, the Ryznar stability index (RsI) is also used to predicate the formation of scale and also the tendency for corrosion due to the concentration of calcium carbonate in the selected water system. Both of the two indexes ((LsI) and (RsI)) had been used to evaluate the internal environmental impact which may be occurred when used once-through pass system is as a cooling method of a coastal pressurized water reactor power plant. The study results showed that the calculated LsI and RsI values for selected regions indicated that, there was a low tendency for scale formation and possibility of corrosion at these selected study areas, so using nickel copper alloys in condenser is recommended to prevent any possibility of attack of corrosion besides the using of chemical treatment method of inlet cooling water system.

关键词： Cooling Water Corrosion Langelier saturation Index

Effect of different geometrical non-uniformities on nonlinear vibration of porous functionally graded skew plates: A finite element study

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Defence Technology（防务技术） 2022年第6期18卷 918-936页

作者： H.s.Naveen Kumar subhaschandra Kattimani Department of mechanical Engineering National Institute of Technology KarnatakaSurathkal575025India

This article presents the investigation of nonlinear vibration analysis of tapered porous functionally graded skew(TPFGs)plate considering the effects of geometrical non-uniformities to optimize the thickness in the structural *** TPFGs plate is analyzed considering linearly,bi-linearly,and exponentially varying *** plate’s effective material properties are tailor-made using a modified power-law distribution in which gradation varies along the thickness direction of the TPFGs *** the non-linear finite element formulation to develop the kinematic equation’s displacement model for the TPFGs plate is based on the first-order shear deformation theory(FsDT)in conjunction with von Karman’s *** nonlinear governing equations are established by Hamilton’s *** direct iterative method is adopted to solve the nonlinear mathematical relations to obtain the nonlinear *** influence of the porosity distributions and porosity parameter indices on the nonlinear frequency responses of the TPFGs plate for different skew angles and variable thicknesses are studied for various geometrical *** influence of taper ratio,variable thickness,skewness,porosity distributions,gradation,and boundary conditions on the plate’s nonlinear vibration is *** nonlinear frequency analysis reveals that the geometrical nonuniformities and porosities significantly influence the porous functionally graded plates with varying thickness than the uniform ***,exponentially and linearly variable thicknesses can be considered for the thickness optimizations of TPFGs plates in the structural design.

关键词： Functionally graded material shear deformation theory Porosity distributions Variable thickness Geometrical skewness Nonlinear free vibration

Profit-Based Optimal Operation of a Head-Dependent Hydroelectric Power station in the Bilateral market

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Journal of Energy and Power Engineering 2011年第5期5卷 466-473页

作者： s.J.P.s. mariano m.R.A. Calado L.A.F.m. Ferreira Dept. of Electromechanical Engineering University of Beira Interior Calqada Fonte do Lameiro Covilh6 6201-001 Portugal Dept. of Electrical Engineering and Computer Instituto Superior TOcnico Av. Rovisco Pais Lisbon 1049-001 Portugal

Deregulation and liberalization of electric power industry, among other things, has created new requirements for the market participants. The power system engineer, operator, and, in general, the market participants are being faced with requirements for which they do not have adequate training and the proper software tools. In this framework, among others, a pure hydro-generation company has to operate its hydro units, throughout the operating day, trying to fulfill the market clearing schedule or a bilateral contract, and modify the program in the intra-day energy markets if necessary （or more suitable） as real-time operation is getting closer. In this scenario the objective is to maximize the hydroelectric power plant profit from selling energy in the spot market or by means of bilateral contracts. In this paper the optimal operation of a head-dependent hydroelectric power station in bilateral market-short-term hourly hydro resource scheduling for energy is obtained.

关键词： Hydroelectric power generation hydroelectric generators optimization methods electricity market.