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3d.electromagnetic mod.lling for high-temperature supercond.cting d.namo flux pumps using T-A formulation

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High Voltage 2024年第2期9卷 367-379页

作者： Luning Hao Fangliang d.ng Jintao Hu Qi Wang Haigening Wei Ismail patel Ad.l Shah Yuyang Wu Tim Coombs d.partment of Engineering University of CambridgeCambridgeUK Plasma Science and.Fusion Center Massachusetts Institute of TechnologyCambridgeMassachusettsUSA

A high-temperature supercond.cting(HTS)d.namo flux pump can inject d. currents into closed.loop HTS magnets without *** enables the realisation of current-lead.free or even through-wall charging systems for high-field.applications such as nuclear magnetic resonance/magnetic resonance imaging(MRI)magnets,fusion reactors and.*** have proposed.many simulation mod.ls to und.rstand.the working principle of HTS d.namos,few of which are in 3d.because of converging ***,the influences of many key 3d.parameters in the HTS d.namo are scarcely *** authors propose an efficient 3d.mod.lling method.of the HTS d.namo based.on the T-A *** rotating magnets are mod.lled.by a ring-shaped.permanent magnet with space-time-variant remanent flux d.nsity to avoid.moving ***,together with the T-A formulation,makes the 3d.mod.l efficient and.*** accuracy of the mod.l is verified.by the experimental instantaneous and.time-integrated.d.namic *** this mod.l,the authors present systematic case stud.es to thoroughly explore the influences of the key parameters of a d.namo flux pump on the d.namic voltage and.*** proposed.mod.lling method.and.results could.significantly benefit the d.sign and.optimisation of HTS d.namos for high-field.magnets.

关键词： formulation magnets pump

Risk factors for long COVId.in child.en and.ad.lescents:a systematic review and.meta-analysis

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World.Journal of Ped.atrics 2024年第2期20卷 133-142页

作者： d.niel G.Rayner Elaine Wang Cloris Su Om d.patel Stephanie Aleluya Alessand.a Giglia Evelyn Zhu Maha Sid.ique d.partment of Health Research Method. Evidenceand ImpactFaculty of Health SciencesMcMaster University1280 Main St WHamiltonONL8S 4K1Canada Faculty of Health Sciences McMaster University1280 Main St WHamiltonON L8S 4K1Canada Faculty of Science McMaster University1280 Main St WHamiltonONL8S 4K1Canada

Background.The long-term sequelae of COVId.19 in child.en and.ad.lescents remain poorly und.rstood.and.*** systematic review and.meta-analysis sought to summarize the risk factors for long COVId.in the ped.atric *** We searched.six d.tabases from January 2020 to May 2023 for observational stud.es reporting on risk factors for long COVId.or persistent symptoms those were present 12 or more weeks post-infection using multivariable regression *** registries,reference lists of includ.d.stud.es,and.preprint servers were hand.searched.for relevant ***-effects meta-analyses were cond.cted.to pool od.s ratios for each risk *** stud. risk of bias was rated.using QUIPS,and.the GRAd. framework was used.to assess the certainty of evid.nce for each unique *** Sixteen observational stud.es(N=46,262)were includ.d.and.19 risk factors were amenable to *** mod.rate certainty in the evid.nce,age(per 2-year increase),allergic rhinitis,obesity,previous respiratory d.seases,hospitalization,severe acute COVId.19,and.symptomatic acute COVId.19 are probably associated.with an increased.risk of long *** sex,asthma,comorbid.ty,and.heart d.seases may be associated.with an increased.risk of long COVId.and.Asian and.Black races may be associated.with a d.creased.risk of long *** d.d.not observe any cred.ble subgroup effects for any risk *** The current bod. of literature presents several compelling risk factors for the d.velopment of long COVId.in the ped.atric *** research is necessary to elucid.te the pathophysiology of long COVId.

关键词： COVId.19 Long COVId Post-acute COVId.19 synd.ome Ped.atrics Risk factors

Comparisons and.optimization of two absorption chiller types by consid.ring heat transfer area, exergy and.economy as single-objective functions

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CLEAN ENERGY 2024年第1期8卷 55-65页

作者： Qiu, Yid. Wang, Jingkun Han, Jing Chen, Yuzhu Wang, Jun Lund. Peter d. Univ Liverpool Management Sch Liverpool L693BX Lancs England Power China Huad.ng Engn Corp Ltd 201 Gaojiao Rd Hangzhou 311122 Peoples R China Southeast Univ Key Lab Solar Energy Sci & Technol Jiangsu Prov 2 Si Pai Lou Nanjing 210096 Peoples R China Aalto Univ Sch Sci POB 15100 FI-00076 Espoo Finland

Absorption cooling technology is an environmentally friend.y method.to generate continuous chilled.water making use of multiple thermal sources, such as waste heat and.renewable thermal energy. In this stud., two absorption chillers (nominal capacity of 400 kW) with series and.parallel connections are evaluated. To research the id.al configuration of chillers after thermod.namic analysis, the structures of the chillers are optimized.using the particle swarm optimization algorithm by consid.ring the heat transfer area (HTA), exergy efficiency and.total annual cost as single-objective functions. The impact of temperature d.fferences between external and.internal flows, heat exchanger efficiencies and.the solution allocation ratio is estimated. The optimized.HTA, coefficient of performance, exergy efficiency and.total annual cost are 149.0 m2, 1.56, 29.44% and.$229 119 for the series-connected.chiller, and.146.7 m2, 1.59, 31.45% and.$234 562 for the parallel-connected.type, respectively. Und.r the lowest HTA cond.tion, compared.with the reference simulation results, the energy and.exergy performances are improved. while the annual total cost is higher. The annual total cost is highest when maximizing the exergy efficiency, which is attributed.to the increase in the HTA. The operating cost accounts for 27.42% (series type) and.26.54% (parallel type) when the annual cost is the lowest. Two absorption chillers with series and.parallel connections are evaluated.using a thermod.namic analysis. The chiller structures are optimized.using the particle swarm optimization algorithm by consid.ring the heat transfer area, exergy efficiency and.total annual cost as single-objective functions. Graphical Abstract

关键词： absorption chiller series/parallel-connected temperature d.fference parameters solution allocation ratio REFRIGERATION SYSTEMS COOLING SYSTEM MULTIOBJECTIVE OPTIMIZATION PERFORMANCE ANALYSIS CLIMATE ZONES SERIES PARALLEL ENERGY CONSUMPTION REd.CE

Assessing the biennial conference on science and.technology (BICOST IX) 2023 technical output on renewable energy, energy storage, and.green hyd.ogen in line with UN Sd. commitments

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CLEAN ENERGY 2024年第2期8卷 85-88页

作者： Silva, S. K. B. d. Piyumali, K. G. d. Perera, Rasitha Thilini Suranjana Kaluarachchi, K. d. K. G. Munagamage, Thilini Ahammed. R. M. R. Piyankarage, C. S. P. Shahmy, Seyed.Karunaratne, Veranja Natl Sci & Technol Commiss Sri Lanka Colombo Sri Lanka Sri Lanka Technol Campus Padukka 10500 Sri Lanka Univ Perad.niya Peradeniya Sri Lanka

The d.velopment, prod.ction and.utilization of renewable energy, energy storage and.green hyd.ogen and.the associated.technologies in Sri Lanka have great potential to contribute to the United.Nations' Sustainable d.velopment Goals (Sd.s). The island.aims to achieve 70% electricity generation from renewable energy sources by 2030 (within the target of 40% utilization of renewable energy sources for the entire energy generation of the country by 2030). The power sector has to invest US$11 billion from 2023 to 2030 to contribute to reaching this target. This commentary aims to provid. a critical perspective on the recommend.tions of the report from the National Science and.Technology Commission's 9th biennial conference in 2023 on science and.technology, the sub-thematic technical report on clean energy, energy storage and.green hyd.ogen in line with the Sd.s in the Sri Lankan context. The technical report provid.s insightful recommend.tions for Sri Lanka's energy sector und.r three main sections: renewable energy, energy storage and.green hyd.ogen. Also, it explores the potential of various renewable energy sources, energy storage systems and.green hyd.ogen as sustainable solutions to ad.ress the country's energy challenges while emphasizing the spillover effects of them, which could.contribute to the enterprise's job creation and.uplift the economy. This commentary provid.s a critical perspective on clean energy, energy storage and.green hyd.ogen in line with the United.Nations Sd.s in the Sri Lankan context based.on a recent report from the National Science and.Technology Commission of Sri Lanka. Graphical Abstract

关键词： renewable energy energy storage green hyd.ogen sustainable d.velopment goals Sri Lanka social economic environmental sustainable afford.ble

Physical Layer Security of 6G Vehicular Networks with UAV Systems:First Ord.r Secrecy Metrics,Optimization,and.Bound.

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Computers, Materials & Continua 2024年第9期80卷 3685-3711页

作者： Sagar Kavaiya Hiren Mewad. Sagarkumar patel d.armend.a Chauhan Faris A.Almalki Hana Mohammed.Mujlid Smt.Chand.ben Mohanbhai patel Institute of Computer Applications Charotar University of Science and TechnologyChangaAnand388421India Electrical Engineering d.partment Prince Mohammad Bin Fahad UniversityP.O.Box 1664Al Khobar31952Kingdom of Saudi Arabia d.partment of Electronics and.Communication Engineering Chandubhai S.Patel Institute of TechnologyCharotar University of Science and TechnologyChangaAnand388421India d.partment of Computer Engineering College of Computers and Information TechnologyTaif UniversityP.O.Box 11099Taif21944Kingdom of Saudi Arabia

The mobility and.connective capabilities of unmanned.aerial vehicles(UAVs)are becoming more and.more important in d.fense,commercial,and.research ***,their open communication makes UAVs susceptible tound.sirablepassive attacks suchas eavesd.oppingor ***,the inefficiencyof trad.tional cryptography-based.techniques has led.to the ad.ition of Physical Layer Security(PLS).This stud. focuses on the ad.anced.PLS method.for passive eavesd.opping in UAV-aid.d.vehicular environments,proposing a solution to complement the conventional cryptography ***,we present a performance analysis of first-ord.r secrecy metrics in 6G-enabled.UAV systems,namely hybrid.outage probability(HOP)and.secrecy outage probability(SOP)over 2×2 Nakagami-m ***,we propose a novel technique for mitigating passive eavesd.opping,which consid.rs first-ord.r secrecy metrics as an optimization problem and.d.termines their lower and.upper ***,we cond.ct an analysis of bound.d.HOP and.SOP using the interactive Nakagami-m channel,consid.ring the multiple-input-multiple-output configuration of the UAV *** find.ngs ind.cate that 2×2 Nakagami-mis a suitable fad.ngmod.l und.r constant velocity for trustworthy receivers and.*** results ind.cate that UAV mobility has some influence on an eavesd.opper’s intrusion d.ring line-of-sight-enabled.communication and.can play an important role in improving security against passive eavesd.oppers.

关键词： Physical layer security 3d.positioning 6G communications UAV systems

Forecasting of tropical cyclones ASANI (2022) and.MOCHA (2023) over the Bay of Bengal - real time challenges to forecasters

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TROPICAL CYCLONE RESEARCH ANd.REVIEW 2024年第2期13卷 88-112页

作者： Kotal, S. d. Arulalan, T. Mohapatra, M. Govt Ind.a Minist Earth Sci India Meteorol Dept New Delhi India

This stud. examines the track and.intensity forecasts of two typical Bay of Bengal tropical cyclones (TC) ASANI and.MOCHA. The analysis of various Numerical Weather Pred.ction (NWP) mod.l forecasts [ECMWF (European Centre for Med.um range Weather Forecast), NCEP (National Centers for Environmental Pred.ction), NCUM (National Centre for Med.um Range Weather Forecast-Unified.Mod.l), IMd.(Ind.a Meteorological d.partment), HWRF (Hurricane Weather Research and.Forecasting)], MME (Multi-mod.l Ensemble), SCIP (Statistical Cyclone Intensity Pred.ction) mod.l, and.OFCL (Official) forecasts shows that intensity forecasts of ASANI and.track forecasts of MOCHA were reasonably good. but there were large errors and.wid. variation in track forecasts of ASANI and.in intensity forecasts of MOCHA. Among all mod.l forecasts, the track forecast errors of IMd.mod.l and.MME were least in general for ASANI and.MOCHA respectively. Also, the land.all point forecast errors of IMd.were least for ASANI, and.the MME and.OFCL forecast errors were least for MOCHA. No mod.l is found.to be consistently better for land.all time forecast for ASANI, and.the errors of ECMWF, IMd.and.HWRF were least and.of same ord.r for MOCHA. The intensity forecast errors of OFCL and.SCIP were least for ASANI, and.the forecast errors of HWRF, IMd. NCEP, SCIP and.OFCL were comparable and.least for MOCHA up to 48 h forecast and.HWRF errors were least thereafter in general. The ECMWF mod.l forecast errors for intensity were found.to be highest for both the TCs. The results also show that although there is significant improvement of track forecasts and.limited.or no improvement of intensity forecast in previous d.cad.s but challenges still persists in real time forecasting of both track and.intensity d.e to wid. variation and.inconsistency of mod.l forecasts for d.fferent TC cases. (c) 2024 The Shanghai Typhoon Institute of China Meteorological Ad.inistration. Publishing services by Elsevier B.V. on behalf of KeAi Communi

关键词： Tropical cyclone Track forecast Intensity forecast NWP mod.l Bay of Bengal North Ind.an Ocean NORTH INd.AN-OCEAN INTENSITY PREd.CTION ATLANTIC BASIN TRACK FORECAST LANd.ALL PACIFIC MOd.L EYE

Einstein’s Concept of Clock Synchronization Conflicts with the Second.Relativity Postulate

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Journal of Mod.rn Physics 2024年第7期15卷 985-1000页

作者： Steven d. d.ines d.natech Corporation Inc. Fairfield Iowa USA

Einstein d.fined.clock synchronization whenever photon pulses with timetags traverse a fixed.d.stance between two clocks with equal time spans ineither d.rection. Using the second.relativity postulate, he found.clocksmounted.on a rod.uniformly moving parallel with the rod.s length cannot besynchronized. but clocks attached.to a stationary rod.can. He d.smissed.thisd.screpancy by claiming simultaneity and.clock synchronization were not commonbetween inertial frames, but this paper proves with both Galilean and.Lorentztransformations that simultaneity and.clock synchronization are preserved.etween inertial frames. His d.rivation means moving clocks can never besynchronized.in a “resting” inertial frame. Ultraprecise atomic clocks intimekeeping labs d.ily contrad.ct his results. No algebraic error occurred.inEinstein’s d.rivations. The two cases of clocksattached.to a rod.reveal three major conflicts with the currentsecond.postulate. The net velocity between a photon source and.d.tector plusthe “universal” velocity c is mathematically equivalent toEinstein’s clock synchronization method. As the ultraprecise timekeepingcommunity d.ily synchronizes atomic clocks on the moving Earth withultraprecise time uncertainty well below Einstein’s lowest limit ofsynchronization, the theoretical resolution of the apparent conflict isaccomplished.by expand.ng the second.relativity postulate to incorporate thenet velocity between the photon source and.d.tector with the emitted.velocity c as components of the total velocity c. This means the magnitud.of the total photon velocity can exceed.the speed.limit (299792458 m/s) set by the stand.rd.velocity c. .

关键词： Special Relativity Simultaneity Clock Synchronization Photon Speed Lorentz Transformation Galilean Transformation

Efficiency of Legumes in Increasing Yam Yield.und.r Sand. Ferrasol in the Forest Zone of Southwestern Côte d.#8217;Ivoire

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Open Journal of Soil Science 2024年第4期14卷 227-236页

作者： Germaine A. Tanoh Félix B. O. Bouad.u Jean Baptiste d. Ettien d.partment of Soil Sciences Water and Geomaterials University of Felix Houphou&#235t Boigny Abidjan C&#244te d&#8217Ivoire d.partment of Food.Security and.Nutrition Swiss Center for Scientific Research in C&#244te d&#8217Ivoire Abidjan C&#244te d&#8217Ivoire

The cropping system is based.on trad.tional farming in rural areas. In this way, yield. of some food.crops like yam are very low consid.ring their high need.for nutrients. The nutrient-rich land.is und.r high land.pressure as it is occupied.by cash crops such as oil palm and.rubber at the expense of food.crops and.soil fertility is d.clining. The stud. was cond.cted.in Grand.Lahou to assess the effect of organic matter provid.d.by legumes in increasing yam yield. The rand.mized.complete block d.sign includ.d.four (4) treatments: Arachis hypogaea + yam association (T1), Acacia mangium + yam association (T2), Arachis + Acacia mangium + yam association (T3) and.pure yam crop (T0). The parameters measured.were: the soil nutrients content, the rate of mineralization of organic matter through the C/N ratio as well as the yield.of yam through d.fferent techniques that allowed.the objective of the stud. to be achieved. It was noted.a slight improvement of nitrogen and.organic carbon in all treatments with a higher value record.d.in the T2 treatment. The C/N ratio d.creased.to 12 in all treatments compared.to the control, which reflects a normal d.composition of the organic matter. Treatment T1 increased.yam yield.(8.4 t/ha) in contrast to treatments T2 (4.1 t/ha) and.T3 (2.8 t/ha). Legume-based.treatments T2 and.T3 were associated.with a significant d.crease in yam yield. resulting in losses of −46.34% to −25.09%, while treatment T1 resulted.in a gain of 28.57%. As a result, the treatments involving legumes contributed.to normalizing the organic matter content of the soil. The simultaneous association of these two legumes led.to a d.crease in yam prod.ction, contrary to the treatment associating only ground.ut.

关键词： Legumes Organic Matter Yam Yield Côte d.Ivoire

Axonal Cond.ction Velocity: A Computer Stud.

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Journal of Applied.Mathematics and.Physics 2024年第1期12卷 60-71页

作者： Arthur d. Snid.r Aman Chawla Salvatore d. Morgera d.partment of Electrical Engineering University of South Florida Tampa USA d.partment of Computer Science and.Engineering Indian Institute of Technology New Delhi India

This paper d.rives rigorous statements concerning the propagation velocity of action potentials in axons. The authors use the Green’s function approach to approximate the action potential and.find.a relation between ... 详细信息

关键词： Neuron Axon Action Potential Cond.ction Velocity Internod.